[www-releases] r356539 - Check in the 8.0.0 release
Hans Wennborg via llvm-commits
llvm-commits at lists.llvm.org
Wed Mar 20 02:13:34 PDT 2019
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl03.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl03.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl03.rst.txt (added)
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+========================================
+Kaleidoscope: Code generation to LLVM IR
+========================================
+
+.. contents::
+ :local:
+
+Chapter 3 Introduction
+======================
+
+Welcome to Chapter 3 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. This chapter shows you how to transform
+the `Abstract Syntax Tree <LangImpl02.html>`_, built in Chapter 2, into
+LLVM IR. This will teach you a little bit about how LLVM does things, as
+well as demonstrate how easy it is to use. It's much more work to build
+a lexer and parser than it is to generate LLVM IR code. :)
+
+**Please note**: the code in this chapter and later require LLVM 3.7 or
+later. LLVM 3.6 and before will not work with it. Also note that you
+need to use a version of this tutorial that matches your LLVM release:
+If you are using an official LLVM release, use the version of the
+documentation included with your release or on the `llvm.org releases
+page <http://llvm.org/releases/>`_.
+
+Code Generation Setup
+=====================
+
+In order to generate LLVM IR, we want some simple setup to get started.
+First we define virtual code generation (codegen) methods in each AST
+class:
+
+.. code-block:: c++
+
+ /// ExprAST - Base class for all expression nodes.
+ class ExprAST {
+ public:
+ virtual ~ExprAST() {}
+ virtual Value *codegen() = 0;
+ };
+
+ /// NumberExprAST - Expression class for numeric literals like "1.0".
+ class NumberExprAST : public ExprAST {
+ double Val;
+
+ public:
+ NumberExprAST(double Val) : Val(Val) {}
+ virtual Value *codegen();
+ };
+ ...
+
+The codegen() method says to emit IR for that AST node along with all
+the things it depends on, and they all return an LLVM Value object.
+"Value" is the class used to represent a "`Static Single Assignment
+(SSA) <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+register" or "SSA value" in LLVM. The most distinct aspect of SSA values
+is that their value is computed as the related instruction executes, and
+it does not get a new value until (and if) the instruction re-executes.
+In other words, there is no way to "change" an SSA value. For more
+information, please read up on `Static Single
+Assignment <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+- the concepts are really quite natural once you grok them.
+
+Note that instead of adding virtual methods to the ExprAST class
+hierarchy, it could also make sense to use a `visitor
+pattern <http://en.wikipedia.org/wiki/Visitor_pattern>`_ or some other
+way to model this. Again, this tutorial won't dwell on good software
+engineering practices: for our purposes, adding a virtual method is
+simplest.
+
+The second thing we want is an "LogError" method like we used for the
+parser, which will be used to report errors found during code generation
+(for example, use of an undeclared parameter):
+
+.. code-block:: c++
+
+ static LLVMContext TheContext;
+ static IRBuilder<> Builder(TheContext);
+ static std::unique_ptr<Module> TheModule;
+ static std::map<std::string, Value *> NamedValues;
+
+ Value *LogErrorV(const char *Str) {
+ LogError(Str);
+ return nullptr;
+ }
+
+The static variables will be used during code generation. ``TheContext``
+is an opaque object that owns a lot of core LLVM data structures, such as
+the type and constant value tables. We don't need to understand it in
+detail, we just need a single instance to pass into APIs that require it.
+
+The ``Builder`` object is a helper object that makes it easy to generate
+LLVM instructions. Instances of the
+`IRBuilder <http://llvm.org/doxygen/IRBuilder_8h-source.html>`_
+class template keep track of the current place to insert instructions
+and has methods to create new instructions.
+
+``TheModule`` is an LLVM construct that contains functions and global
+variables. In many ways, it is the top-level structure that the LLVM IR
+uses to contain code. It will own the memory for all of the IR that we
+generate, which is why the codegen() method returns a raw Value\*,
+rather than a unique_ptr<Value>.
+
+The ``NamedValues`` map keeps track of which values are defined in the
+current scope and what their LLVM representation is. (In other words, it
+is a symbol table for the code). In this form of Kaleidoscope, the only
+things that can be referenced are function parameters. As such, function
+parameters will be in this map when generating code for their function
+body.
+
+With these basics in place, we can start talking about how to generate
+code for each expression. Note that this assumes that the ``Builder``
+has been set up to generate code *into* something. For now, we'll assume
+that this has already been done, and we'll just use it to emit code.
+
+Expression Code Generation
+==========================
+
+Generating LLVM code for expression nodes is very straightforward: less
+than 45 lines of commented code for all four of our expression nodes.
+First we'll do numeric literals:
+
+.. code-block:: c++
+
+ Value *NumberExprAST::codegen() {
+ return ConstantFP::get(TheContext, APFloat(Val));
+ }
+
+In the LLVM IR, numeric constants are represented with the
+``ConstantFP`` class, which holds the numeric value in an ``APFloat``
+internally (``APFloat`` has the capability of holding floating point
+constants of Arbitrary Precision). This code basically just creates
+and returns a ``ConstantFP``. Note that in the LLVM IR that constants
+are all uniqued together and shared. For this reason, the API uses the
+"foo::get(...)" idiom instead of "new foo(..)" or "foo::Create(..)".
+
+.. code-block:: c++
+
+ Value *VariableExprAST::codegen() {
+ // Look this variable up in the function.
+ Value *V = NamedValues[Name];
+ if (!V)
+ LogErrorV("Unknown variable name");
+ return V;
+ }
+
+References to variables are also quite simple using LLVM. In the simple
+version of Kaleidoscope, we assume that the variable has already been
+emitted somewhere and its value is available. In practice, the only
+values that can be in the ``NamedValues`` map are function arguments.
+This code simply checks to see that the specified name is in the map (if
+not, an unknown variable is being referenced) and returns the value for
+it. In future chapters, we'll add support for `loop induction
+variables <LangImpl5.html#for-loop-expression>`_ in the symbol table, and for `local
+variables <LangImpl7.html#user-defined-local-variables>`_.
+
+.. code-block:: c++
+
+ Value *BinaryExprAST::codegen() {
+ Value *L = LHS->codegen();
+ Value *R = RHS->codegen();
+ if (!L || !R)
+ return nullptr;
+
+ switch (Op) {
+ case '+':
+ return Builder.CreateFAdd(L, R, "addtmp");
+ case '-':
+ return Builder.CreateFSub(L, R, "subtmp");
+ case '*':
+ return Builder.CreateFMul(L, R, "multmp");
+ case '<':
+ L = Builder.CreateFCmpULT(L, R, "cmptmp");
+ // Convert bool 0/1 to double 0.0 or 1.0
+ return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext),
+ "booltmp");
+ default:
+ return LogErrorV("invalid binary operator");
+ }
+ }
+
+Binary operators start to get more interesting. The basic idea here is
+that we recursively emit code for the left-hand side of the expression,
+then the right-hand side, then we compute the result of the binary
+expression. In this code, we do a simple switch on the opcode to create
+the right LLVM instruction.
+
+In the example above, the LLVM builder class is starting to show its
+value. IRBuilder knows where to insert the newly created instruction,
+all you have to do is specify what instruction to create (e.g. with
+``CreateFAdd``), which operands to use (``L`` and ``R`` here) and
+optionally provide a name for the generated instruction.
+
+One nice thing about LLVM is that the name is just a hint. For instance,
+if the code above emits multiple "addtmp" variables, LLVM will
+automatically provide each one with an increasing, unique numeric
+suffix. Local value names for instructions are purely optional, but it
+makes it much easier to read the IR dumps.
+
+`LLVM instructions <../LangRef.html#instruction-reference>`_ are constrained by strict
+rules: for example, the Left and Right operators of an `add
+instruction <../LangRef.html#add-instruction>`_ must have the same type, and the
+result type of the add must match the operand types. Because all values
+in Kaleidoscope are doubles, this makes for very simple code for add,
+sub and mul.
+
+On the other hand, LLVM specifies that the `fcmp
+instruction <../LangRef.html#fcmp-instruction>`_ always returns an 'i1' value (a
+one bit integer). The problem with this is that Kaleidoscope wants the
+value to be a 0.0 or 1.0 value. In order to get these semantics, we
+combine the fcmp instruction with a `uitofp
+instruction <../LangRef.html#uitofp-to-instruction>`_. This instruction converts its
+input integer into a floating point value by treating the input as an
+unsigned value. In contrast, if we used the `sitofp
+instruction <../LangRef.html#sitofp-to-instruction>`_, the Kaleidoscope '<' operator
+would return 0.0 and -1.0, depending on the input value.
+
+.. code-block:: c++
+
+ Value *CallExprAST::codegen() {
+ // Look up the name in the global module table.
+ Function *CalleeF = TheModule->getFunction(Callee);
+ if (!CalleeF)
+ return LogErrorV("Unknown function referenced");
+
+ // If argument mismatch error.
+ if (CalleeF->arg_size() != Args.size())
+ return LogErrorV("Incorrect # arguments passed");
+
+ std::vector<Value *> ArgsV;
+ for (unsigned i = 0, e = Args.size(); i != e; ++i) {
+ ArgsV.push_back(Args[i]->codegen());
+ if (!ArgsV.back())
+ return nullptr;
+ }
+
+ return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
+ }
+
+Code generation for function calls is quite straightforward with LLVM. The code
+above initially does a function name lookup in the LLVM Module's symbol table.
+Recall that the LLVM Module is the container that holds the functions we are
+JIT'ing. By giving each function the same name as what the user specifies, we
+can use the LLVM symbol table to resolve function names for us.
+
+Once we have the function to call, we recursively codegen each argument
+that is to be passed in, and create an LLVM `call
+instruction <../LangRef.html#call-instruction>`_. Note that LLVM uses the native C
+calling conventions by default, allowing these calls to also call into
+standard library functions like "sin" and "cos", with no additional
+effort.
+
+This wraps up our handling of the four basic expressions that we have so
+far in Kaleidoscope. Feel free to go in and add some more. For example,
+by browsing the `LLVM language reference <../LangRef.html>`_ you'll find
+several other interesting instructions that are really easy to plug into
+our basic framework.
+
+Function Code Generation
+========================
+
+Code generation for prototypes and functions must handle a number of
+details, which make their code less beautiful than expression code
+generation, but allows us to illustrate some important points. First,
+let's talk about code generation for prototypes: they are used both for
+function bodies and external function declarations. The code starts
+with:
+
+.. code-block:: c++
+
+ Function *PrototypeAST::codegen() {
+ // Make the function type: double(double,double) etc.
+ std::vector<Type*> Doubles(Args.size(),
+ Type::getDoubleTy(TheContext));
+ FunctionType *FT =
+ FunctionType::get(Type::getDoubleTy(TheContext), Doubles, false);
+
+ Function *F =
+ Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
+This code packs a lot of power into a few lines. Note first that this
+function returns a "Function\*" instead of a "Value\*". Because a
+"prototype" really talks about the external interface for a function
+(not the value computed by an expression), it makes sense for it to
+return the LLVM Function it corresponds to when codegen'd.
+
+The call to ``FunctionType::get`` creates the ``FunctionType`` that
+should be used for a given Prototype. Since all function arguments in
+Kaleidoscope are of type double, the first line creates a vector of "N"
+LLVM double types. It then uses the ``Functiontype::get`` method to
+create a function type that takes "N" doubles as arguments, returns one
+double as a result, and that is not vararg (the false parameter
+indicates this). Note that Types in LLVM are uniqued just like Constants
+are, so you don't "new" a type, you "get" it.
+
+The final line above actually creates the IR Function corresponding to
+the Prototype. This indicates the type, linkage and name to use, as
+well as which module to insert into. "`external
+linkage <../LangRef.html#linkage>`_" means that the function may be
+defined outside the current module and/or that it is callable by
+functions outside the module. The Name passed in is the name the user
+specified: since "``TheModule``" is specified, this name is registered
+in "``TheModule``"s symbol table.
+
+.. code-block:: c++
+
+ // Set names for all arguments.
+ unsigned Idx = 0;
+ for (auto &Arg : F->args())
+ Arg.setName(Args[Idx++]);
+
+ return F;
+
+Finally, we set the name of each of the function's arguments according to the
+names given in the Prototype. This step isn't strictly necessary, but keeping
+the names consistent makes the IR more readable, and allows subsequent code to
+refer directly to the arguments for their names, rather than having to look up
+them up in the Prototype AST.
+
+At this point we have a function prototype with no body. This is how LLVM IR
+represents function declarations. For extern statements in Kaleidoscope, this
+is as far as we need to go. For function definitions however, we need to
+codegen and attach a function body.
+
+.. code-block:: c++
+
+ Function *FunctionAST::codegen() {
+ // First, check for an existing function from a previous 'extern' declaration.
+ Function *TheFunction = TheModule->getFunction(Proto->getName());
+
+ if (!TheFunction)
+ TheFunction = Proto->codegen();
+
+ if (!TheFunction)
+ return nullptr;
+
+ if (!TheFunction->empty())
+ return (Function*)LogErrorV("Function cannot be redefined.");
+
+
+For function definitions, we start by searching TheModule's symbol table for an
+existing version of this function, in case one has already been created using an
+'extern' statement. If Module::getFunction returns null then no previous version
+exists, so we'll codegen one from the Prototype. In either case, we want to
+assert that the function is empty (i.e. has no body yet) before we start.
+
+.. code-block:: c++
+
+ // Create a new basic block to start insertion into.
+ BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
+ Builder.SetInsertPoint(BB);
+
+ // Record the function arguments in the NamedValues map.
+ NamedValues.clear();
+ for (auto &Arg : TheFunction->args())
+ NamedValues[Arg.getName()] = &Arg;
+
+Now we get to the point where the ``Builder`` is set up. The first line
+creates a new `basic block <http://en.wikipedia.org/wiki/Basic_block>`_
+(named "entry"), which is inserted into ``TheFunction``. The second line
+then tells the builder that new instructions should be inserted into the
+end of the new basic block. Basic blocks in LLVM are an important part
+of functions that define the `Control Flow
+Graph <http://en.wikipedia.org/wiki/Control_flow_graph>`_. Since we
+don't have any control flow, our functions will only contain one block
+at this point. We'll fix this in `Chapter 5 <LangImpl05.html>`_ :).
+
+Next we add the function arguments to the NamedValues map (after first clearing
+it out) so that they're accessible to ``VariableExprAST`` nodes.
+
+.. code-block:: c++
+
+ if (Value *RetVal = Body->codegen()) {
+ // Finish off the function.
+ Builder.CreateRet(RetVal);
+
+ // Validate the generated code, checking for consistency.
+ verifyFunction(*TheFunction);
+
+ return TheFunction;
+ }
+
+Once the insertion point has been set up and the NamedValues map populated,
+we call the ``codegen()`` method for the root expression of the function. If no
+error happens, this emits code to compute the expression into the entry block
+and returns the value that was computed. Assuming no error, we then create an
+LLVM `ret instruction <../LangRef.html#ret-instruction>`_, which completes the function.
+Once the function is built, we call ``verifyFunction``, which is
+provided by LLVM. This function does a variety of consistency checks on
+the generated code, to determine if our compiler is doing everything
+right. Using this is important: it can catch a lot of bugs. Once the
+function is finished and validated, we return it.
+
+.. code-block:: c++
+
+ // Error reading body, remove function.
+ TheFunction->eraseFromParent();
+ return nullptr;
+ }
+
+The only piece left here is handling of the error case. For simplicity,
+we handle this by merely deleting the function we produced with the
+``eraseFromParent`` method. This allows the user to redefine a function
+that they incorrectly typed in before: if we didn't delete it, it would
+live in the symbol table, with a body, preventing future redefinition.
+
+This code does have a bug, though: If the ``FunctionAST::codegen()`` method
+finds an existing IR Function, it does not validate its signature against the
+definition's own prototype. This means that an earlier 'extern' declaration will
+take precedence over the function definition's signature, which can cause
+codegen to fail, for instance if the function arguments are named differently.
+There are a number of ways to fix this bug, see what you can come up with! Here
+is a testcase:
+
+::
+
+ extern foo(a); # ok, defines foo.
+ def foo(b) b; # Error: Unknown variable name. (decl using 'a' takes precedence).
+
+Driver Changes and Closing Thoughts
+===================================
+
+For now, code generation to LLVM doesn't really get us much, except that
+we can look at the pretty IR calls. The sample code inserts calls to
+codegen into the "``HandleDefinition``", "``HandleExtern``" etc
+functions, and then dumps out the LLVM IR. This gives a nice way to look
+at the LLVM IR for simple functions. For example:
+
+::
+
+ ready> 4+5;
+ Read top-level expression:
+ define double @0() {
+ entry:
+ ret double 9.000000e+00
+ }
+
+Note how the parser turns the top-level expression into anonymous
+functions for us. This will be handy when we add `JIT
+support <LangImpl4.html#adding-a-jit-compiler>`_ in the next chapter. Also note that the
+code is very literally transcribed, no optimizations are being performed
+except simple constant folding done by IRBuilder. We will `add
+optimizations <LangImpl4.html#trivial-constant-folding>`_ explicitly in the next
+chapter.
+
+::
+
+ ready> def foo(a b) a*a + 2*a*b + b*b;
+ Read function definition:
+ define double @foo(double %a, double %b) {
+ entry:
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
+ }
+
+This shows some simple arithmetic. Notice the striking similarity to the
+LLVM builder calls that we use to create the instructions.
+
+::
+
+ ready> def bar(a) foo(a, 4.0) + bar(31337);
+ Read function definition:
+ define double @bar(double %a) {
+ entry:
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
+ }
+
+This shows some function calls. Note that this function will take a long
+time to execute if you call it. In the future we'll add conditional
+control flow to actually make recursion useful :).
+
+::
+
+ ready> extern cos(x);
+ Read extern:
+ declare double @cos(double)
+
+ ready> cos(1.234);
+ Read top-level expression:
+ define double @1() {
+ entry:
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
+ }
+
+This shows an extern for the libm "cos" function, and a call to it.
+
+.. TODO:: Abandon Pygments' horrible `llvm` lexer. It just totally gives up
+ on highlighting this due to the first line.
+
+::
+
+ ready> ^D
+ ; ModuleID = 'my cool jit'
+
+ define double @0() {
+ entry:
+ %addtmp = fadd double 4.000000e+00, 5.000000e+00
+ ret double %addtmp
+ }
+
+ define double @foo(double %a, double %b) {
+ entry:
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
+ }
+
+ define double @bar(double %a) {
+ entry:
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
+ }
+
+ declare double @cos(double)
+
+ define double @1() {
+ entry:
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
+ }
+
+When you quit the current demo (by sending an EOF via CTRL+D on Linux
+or CTRL+Z and ENTER on Windows), it dumps out the IR for the entire
+module generated. Here you can see the big picture with all the
+functions referencing each other.
+
+This wraps up the third chapter of the Kaleidoscope tutorial. Up next,
+we'll describe how to `add JIT codegen and optimizer
+support <LangImpl04.html>`_ to this so we can actually start running
+code!
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the LLVM code generator. Because this uses the LLVM libraries, we need
+to link them in. To do this, we use the
+`llvm-config <http://llvm.org/cmds/llvm-config.html>`_ tool to inform
+our makefile/command line about which options to use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g -O3 toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core` -o toy
+ # Run
+ ./toy
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter3/toy.cpp
+ :language: c++
+
+`Next: Adding JIT and Optimizer Support <LangImpl04.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl04.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl04.rst.txt?rev=356539&view=auto
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--- www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl04.rst.txt (added)
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@@ -0,0 +1,651 @@
+==============================================
+Kaleidoscope: Adding JIT and Optimizer Support
+==============================================
+
+.. contents::
+ :local:
+
+Chapter 4 Introduction
+======================
+
+Welcome to Chapter 4 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. Chapters 1-3 described the implementation
+of a simple language and added support for generating LLVM IR. This
+chapter describes two new techniques: adding optimizer support to your
+language, and adding JIT compiler support. These additions will
+demonstrate how to get nice, efficient code for the Kaleidoscope
+language.
+
+Trivial Constant Folding
+========================
+
+Our demonstration for Chapter 3 is elegant and easy to extend.
+Unfortunately, it does not produce wonderful code. The IRBuilder,
+however, does give us obvious optimizations when compiling simple code:
+
+::
+
+ ready> def test(x) 1+2+x;
+ Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 3.000000e+00, %x
+ ret double %addtmp
+ }
+
+This code is not a literal transcription of the AST built by parsing the
+input. That would be:
+
+::
+
+ ready> def test(x) 1+2+x;
+ Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 2.000000e+00, 1.000000e+00
+ %addtmp1 = fadd double %addtmp, %x
+ ret double %addtmp1
+ }
+
+Constant folding, as seen above, in particular, is a very common and
+very important optimization: so much so that many language implementors
+implement constant folding support in their AST representation.
+
+With LLVM, you don't need this support in the AST. Since all calls to
+build LLVM IR go through the LLVM IR builder, the builder itself checked
+to see if there was a constant folding opportunity when you call it. If
+so, it just does the constant fold and return the constant instead of
+creating an instruction.
+
+Well, that was easy :). In practice, we recommend always using
+``IRBuilder`` when generating code like this. It has no "syntactic
+overhead" for its use (you don't have to uglify your compiler with
+constant checks everywhere) and it can dramatically reduce the amount of
+LLVM IR that is generated in some cases (particular for languages with a
+macro preprocessor or that use a lot of constants).
+
+On the other hand, the ``IRBuilder`` is limited by the fact that it does
+all of its analysis inline with the code as it is built. If you take a
+slightly more complex example:
+
+::
+
+ ready> def test(x) (1+2+x)*(x+(1+2));
+ ready> Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 3.000000e+00, %x
+ %addtmp1 = fadd double %x, 3.000000e+00
+ %multmp = fmul double %addtmp, %addtmp1
+ ret double %multmp
+ }
+
+In this case, the LHS and RHS of the multiplication are the same value.
+We'd really like to see this generate "``tmp = x+3; result = tmp*tmp;``"
+instead of computing "``x+3``" twice.
+
+Unfortunately, no amount of local analysis will be able to detect and
+correct this. This requires two transformations: reassociation of
+expressions (to make the add's lexically identical) and Common
+Subexpression Elimination (CSE) to delete the redundant add instruction.
+Fortunately, LLVM provides a broad range of optimizations that you can
+use, in the form of "passes".
+
+LLVM Optimization Passes
+========================
+
+LLVM provides many optimization passes, which do many different sorts of
+things and have different tradeoffs. Unlike other systems, LLVM doesn't
+hold to the mistaken notion that one set of optimizations is right for
+all languages and for all situations. LLVM allows a compiler implementor
+to make complete decisions about what optimizations to use, in which
+order, and in what situation.
+
+As a concrete example, LLVM supports both "whole module" passes, which
+look across as large of body of code as they can (often a whole file,
+but if run at link time, this can be a substantial portion of the whole
+program). It also supports and includes "per-function" passes which just
+operate on a single function at a time, without looking at other
+functions. For more information on passes and how they are run, see the
+`How to Write a Pass <../WritingAnLLVMPass.html>`_ document and the
+`List of LLVM Passes <../Passes.html>`_.
+
+For Kaleidoscope, we are currently generating functions on the fly, one
+at a time, as the user types them in. We aren't shooting for the
+ultimate optimization experience in this setting, but we also want to
+catch the easy and quick stuff where possible. As such, we will choose
+to run a few per-function optimizations as the user types the function
+in. If we wanted to make a "static Kaleidoscope compiler", we would use
+exactly the code we have now, except that we would defer running the
+optimizer until the entire file has been parsed.
+
+In order to get per-function optimizations going, we need to set up a
+`FunctionPassManager <../WritingAnLLVMPass.html#what-passmanager-doesr>`_ to hold
+and organize the LLVM optimizations that we want to run. Once we have
+that, we can add a set of optimizations to run. We'll need a new
+FunctionPassManager for each module that we want to optimize, so we'll
+write a function to create and initialize both the module and pass manager
+for us:
+
+.. code-block:: c++
+
+ void InitializeModuleAndPassManager(void) {
+ // Open a new module.
+ TheModule = llvm::make_unique<Module>("my cool jit", TheContext);
+
+ // Create a new pass manager attached to it.
+ TheFPM = llvm::make_unique<FunctionPassManager>(TheModule.get());
+
+ // Do simple "peephole" optimizations and bit-twiddling optzns.
+ TheFPM->add(createInstructionCombiningPass());
+ // Reassociate expressions.
+ TheFPM->add(createReassociatePass());
+ // Eliminate Common SubExpressions.
+ TheFPM->add(createGVNPass());
+ // Simplify the control flow graph (deleting unreachable blocks, etc).
+ TheFPM->add(createCFGSimplificationPass());
+
+ TheFPM->doInitialization();
+ }
+
+This code initializes the global module ``TheModule``, and the function pass
+manager ``TheFPM``, which is attached to ``TheModule``. Once the pass manager is
+set up, we use a series of "add" calls to add a bunch of LLVM passes.
+
+In this case, we choose to add four optimization passes.
+The passes we choose here are a pretty standard set
+of "cleanup" optimizations that are useful for a wide variety of code. I won't
+delve into what they do but, believe me, they are a good starting place :).
+
+Once the PassManager is set up, we need to make use of it. We do this by
+running it after our newly created function is constructed (in
+``FunctionAST::codegen()``), but before it is returned to the client:
+
+.. code-block:: c++
+
+ if (Value *RetVal = Body->codegen()) {
+ // Finish off the function.
+ Builder.CreateRet(RetVal);
+
+ // Validate the generated code, checking for consistency.
+ verifyFunction(*TheFunction);
+
+ // Optimize the function.
+ TheFPM->run(*TheFunction);
+
+ return TheFunction;
+ }
+
+As you can see, this is pretty straightforward. The
+``FunctionPassManager`` optimizes and updates the LLVM Function\* in
+place, improving (hopefully) its body. With this in place, we can try
+our test above again:
+
+::
+
+ ready> def test(x) (1+2+x)*(x+(1+2));
+ ready> Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double %x, 3.000000e+00
+ %multmp = fmul double %addtmp, %addtmp
+ ret double %multmp
+ }
+
+As expected, we now get our nicely optimized code, saving a floating
+point add instruction from every execution of this function.
+
+LLVM provides a wide variety of optimizations that can be used in
+certain circumstances. Some `documentation about the various
+passes <../Passes.html>`_ is available, but it isn't very complete.
+Another good source of ideas can come from looking at the passes that
+``Clang`` runs to get started. The "``opt``" tool allows you to
+experiment with passes from the command line, so you can see if they do
+anything.
+
+Now that we have reasonable code coming out of our front-end, let's talk
+about executing it!
+
+Adding a JIT Compiler
+=====================
+
+Code that is available in LLVM IR can have a wide variety of tools
+applied to it. For example, you can run optimizations on it (as we did
+above), you can dump it out in textual or binary forms, you can compile
+the code to an assembly file (.s) for some target, or you can JIT
+compile it. The nice thing about the LLVM IR representation is that it
+is the "common currency" between many different parts of the compiler.
+
+In this section, we'll add JIT compiler support to our interpreter. The
+basic idea that we want for Kaleidoscope is to have the user enter
+function bodies as they do now, but immediately evaluate the top-level
+expressions they type in. For example, if they type in "1 + 2;", we
+should evaluate and print out 3. If they define a function, they should
+be able to call it from the command line.
+
+In order to do this, we first prepare the environment to create code for
+the current native target and declare and initialize the JIT. This is
+done by calling some ``InitializeNativeTarget\*`` functions and
+adding a global variable ``TheJIT``, and initializing it in
+``main``:
+
+.. code-block:: c++
+
+ static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+ ...
+ int main() {
+ InitializeNativeTarget();
+ InitializeNativeTargetAsmPrinter();
+ InitializeNativeTargetAsmParser();
+
+ // Install standard binary operators.
+ // 1 is lowest precedence.
+ BinopPrecedence['<'] = 10;
+ BinopPrecedence['+'] = 20;
+ BinopPrecedence['-'] = 20;
+ BinopPrecedence['*'] = 40; // highest.
+
+ // Prime the first token.
+ fprintf(stderr, "ready> ");
+ getNextToken();
+
+ TheJIT = llvm::make_unique<KaleidoscopeJIT>();
+
+ // Run the main "interpreter loop" now.
+ MainLoop();
+
+ return 0;
+ }
+
+We also need to setup the data layout for the JIT:
+
+.. code-block:: c++
+
+ void InitializeModuleAndPassManager(void) {
+ // Open a new module.
+ TheModule = llvm::make_unique<Module>("my cool jit", TheContext);
+ TheModule->setDataLayout(TheJIT->getTargetMachine().createDataLayout());
+
+ // Create a new pass manager attached to it.
+ TheFPM = llvm::make_unique<FunctionPassManager>(TheModule.get());
+ ...
+
+The KaleidoscopeJIT class is a simple JIT built specifically for these
+tutorials, available inside the LLVM source code
+at llvm-src/examples/Kaleidoscope/include/KaleidoscopeJIT.h.
+In later chapters we will look at how it works and extend it with
+new features, but for now we will take it as given. Its API is very simple:
+``addModule`` adds an LLVM IR module to the JIT, making its functions
+available for execution; ``removeModule`` removes a module, freeing any
+memory associated with the code in that module; and ``findSymbol`` allows us
+to look up pointers to the compiled code.
+
+We can take this simple API and change our code that parses top-level expressions to
+look like this:
+
+.. code-block:: c++
+
+ static void HandleTopLevelExpression() {
+ // Evaluate a top-level expression into an anonymous function.
+ if (auto FnAST = ParseTopLevelExpr()) {
+ if (FnAST->codegen()) {
+
+ // JIT the module containing the anonymous expression, keeping a handle so
+ // we can free it later.
+ auto H = TheJIT->addModule(std::move(TheModule));
+ InitializeModuleAndPassManager();
+
+ // Search the JIT for the __anon_expr symbol.
+ auto ExprSymbol = TheJIT->findSymbol("__anon_expr");
+ assert(ExprSymbol && "Function not found");
+
+ // Get the symbol's address and cast it to the right type (takes no
+ // arguments, returns a double) so we can call it as a native function.
+ double (*FP)() = (double (*)())(intptr_t)ExprSymbol.getAddress();
+ fprintf(stderr, "Evaluated to %f\n", FP());
+
+ // Delete the anonymous expression module from the JIT.
+ TheJIT->removeModule(H);
+ }
+
+If parsing and codegen succeeed, the next step is to add the module containing
+the top-level expression to the JIT. We do this by calling addModule, which
+triggers code generation for all the functions in the module, and returns a
+handle that can be used to remove the module from the JIT later. Once the module
+has been added to the JIT it can no longer be modified, so we also open a new
+module to hold subsequent code by calling ``InitializeModuleAndPassManager()``.
+
+Once we've added the module to the JIT we need to get a pointer to the final
+generated code. We do this by calling the JIT's findSymbol method, and passing
+the name of the top-level expression function: ``__anon_expr``. Since we just
+added this function, we assert that findSymbol returned a result.
+
+Next, we get the in-memory address of the ``__anon_expr`` function by calling
+``getAddress()`` on the symbol. Recall that we compile top-level expressions
+into a self-contained LLVM function that takes no arguments and returns the
+computed double. Because the LLVM JIT compiler matches the native platform ABI,
+this means that you can just cast the result pointer to a function pointer of
+that type and call it directly. This means, there is no difference between JIT
+compiled code and native machine code that is statically linked into your
+application.
+
+Finally, since we don't support re-evaluation of top-level expressions, we
+remove the module from the JIT when we're done to free the associated memory.
+Recall, however, that the module we created a few lines earlier (via
+``InitializeModuleAndPassManager``) is still open and waiting for new code to be
+added.
+
+With just these two changes, let's see how Kaleidoscope works now!
+
+::
+
+ ready> 4+5;
+ Read top-level expression:
+ define double @0() {
+ entry:
+ ret double 9.000000e+00
+ }
+
+ Evaluated to 9.000000
+
+Well this looks like it is basically working. The dump of the function
+shows the "no argument function that always returns double" that we
+synthesize for each top-level expression that is typed in. This
+demonstrates very basic functionality, but can we do more?
+
+::
+
+ ready> def testfunc(x y) x + y*2;
+ Read function definition:
+ define double @testfunc(double %x, double %y) {
+ entry:
+ %multmp = fmul double %y, 2.000000e+00
+ %addtmp = fadd double %multmp, %x
+ ret double %addtmp
+ }
+
+ ready> testfunc(4, 10);
+ Read top-level expression:
+ define double @1() {
+ entry:
+ %calltmp = call double @testfunc(double 4.000000e+00, double 1.000000e+01)
+ ret double %calltmp
+ }
+
+ Evaluated to 24.000000
+
+ ready> testfunc(5, 10);
+ ready> LLVM ERROR: Program used external function 'testfunc' which could not be resolved!
+
+
+Function definitions and calls also work, but something went very wrong on that
+last line. The call looks valid, so what happened? As you may have guessed from
+the API a Module is a unit of allocation for the JIT, and testfunc was part
+of the same module that contained anonymous expression. When we removed that
+module from the JIT to free the memory for the anonymous expression, we deleted
+the definition of ``testfunc`` along with it. Then, when we tried to call
+testfunc a second time, the JIT could no longer find it.
+
+The easiest way to fix this is to put the anonymous expression in a separate
+module from the rest of the function definitions. The JIT will happily resolve
+function calls across module boundaries, as long as each of the functions called
+has a prototype, and is added to the JIT before it is called. By putting the
+anonymous expression in a different module we can delete it without affecting
+the rest of the functions.
+
+In fact, we're going to go a step further and put every function in its own
+module. Doing so allows us to exploit a useful property of the KaleidoscopeJIT
+that will make our environment more REPL-like: Functions can be added to the
+JIT more than once (unlike a module where every function must have a unique
+definition). When you look up a symbol in KaleidoscopeJIT it will always return
+the most recent definition:
+
+::
+
+ ready> def foo(x) x + 1;
+ Read function definition:
+ define double @foo(double %x) {
+ entry:
+ %addtmp = fadd double %x, 1.000000e+00
+ ret double %addtmp
+ }
+
+ ready> foo(2);
+ Evaluated to 3.000000
+
+ ready> def foo(x) x + 2;
+ define double @foo(double %x) {
+ entry:
+ %addtmp = fadd double %x, 2.000000e+00
+ ret double %addtmp
+ }
+
+ ready> foo(2);
+ Evaluated to 4.000000
+
+
+To allow each function to live in its own module we'll need a way to
+re-generate previous function declarations into each new module we open:
+
+.. code-block:: c++
+
+ static std::unique_ptr<KaleidoscopeJIT> TheJIT;
+
+ ...
+
+ Function *getFunction(std::string Name) {
+ // First, see if the function has already been added to the current module.
+ if (auto *F = TheModule->getFunction(Name))
+ return F;
+
+ // If not, check whether we can codegen the declaration from some existing
+ // prototype.
+ auto FI = FunctionProtos.find(Name);
+ if (FI != FunctionProtos.end())
+ return FI->second->codegen();
+
+ // If no existing prototype exists, return null.
+ return nullptr;
+ }
+
+ ...
+
+ Value *CallExprAST::codegen() {
+ // Look up the name in the global module table.
+ Function *CalleeF = getFunction(Callee);
+
+ ...
+
+ Function *FunctionAST::codegen() {
+ // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+ // reference to it for use below.
+ auto &P = *Proto;
+ FunctionProtos[Proto->getName()] = std::move(Proto);
+ Function *TheFunction = getFunction(P.getName());
+ if (!TheFunction)
+ return nullptr;
+
+
+To enable this, we'll start by adding a new global, ``FunctionProtos``, that
+holds the most recent prototype for each function. We'll also add a convenience
+method, ``getFunction()``, to replace calls to ``TheModule->getFunction()``.
+Our convenience method searches ``TheModule`` for an existing function
+declaration, falling back to generating a new declaration from FunctionProtos if
+it doesn't find one. In ``CallExprAST::codegen()`` we just need to replace the
+call to ``TheModule->getFunction()``. In ``FunctionAST::codegen()`` we need to
+update the FunctionProtos map first, then call ``getFunction()``. With this
+done, we can always obtain a function declaration in the current module for any
+previously declared function.
+
+We also need to update HandleDefinition and HandleExtern:
+
+.. code-block:: c++
+
+ static void HandleDefinition() {
+ if (auto FnAST = ParseDefinition()) {
+ if (auto *FnIR = FnAST->codegen()) {
+ fprintf(stderr, "Read function definition:");
+ FnIR->print(errs());
+ fprintf(stderr, "\n");
+ TheJIT->addModule(std::move(TheModule));
+ InitializeModuleAndPassManager();
+ }
+ } else {
+ // Skip token for error recovery.
+ getNextToken();
+ }
+ }
+
+ static void HandleExtern() {
+ if (auto ProtoAST = ParseExtern()) {
+ if (auto *FnIR = ProtoAST->codegen()) {
+ fprintf(stderr, "Read extern: ");
+ FnIR->print(errs());
+ fprintf(stderr, "\n");
+ FunctionProtos[ProtoAST->getName()] = std::move(ProtoAST);
+ }
+ } else {
+ // Skip token for error recovery.
+ getNextToken();
+ }
+ }
+
+In HandleDefinition, we add two lines to transfer the newly defined function to
+the JIT and open a new module. In HandleExtern, we just need to add one line to
+add the prototype to FunctionProtos.
+
+With these changes made, let's try our REPL again (I removed the dump of the
+anonymous functions this time, you should get the idea by now :) :
+
+::
+
+ ready> def foo(x) x + 1;
+ ready> foo(2);
+ Evaluated to 3.000000
+
+ ready> def foo(x) x + 2;
+ ready> foo(2);
+ Evaluated to 4.000000
+
+It works!
+
+Even with this simple code, we get some surprisingly powerful capabilities -
+check this out:
+
+::
+
+ ready> extern sin(x);
+ Read extern:
+ declare double @sin(double)
+
+ ready> extern cos(x);
+ Read extern:
+ declare double @cos(double)
+
+ ready> sin(1.0);
+ Read top-level expression:
+ define double @2() {
+ entry:
+ ret double 0x3FEAED548F090CEE
+ }
+
+ Evaluated to 0.841471
+
+ ready> def foo(x) sin(x)*sin(x) + cos(x)*cos(x);
+ Read function definition:
+ define double @foo(double %x) {
+ entry:
+ %calltmp = call double @sin(double %x)
+ %multmp = fmul double %calltmp, %calltmp
+ %calltmp2 = call double @cos(double %x)
+ %multmp4 = fmul double %calltmp2, %calltmp2
+ %addtmp = fadd double %multmp, %multmp4
+ ret double %addtmp
+ }
+
+ ready> foo(4.0);
+ Read top-level expression:
+ define double @3() {
+ entry:
+ %calltmp = call double @foo(double 4.000000e+00)
+ ret double %calltmp
+ }
+
+ Evaluated to 1.000000
+
+Whoa, how does the JIT know about sin and cos? The answer is surprisingly
+simple: The KaleidoscopeJIT has a straightforward symbol resolution rule that
+it uses to find symbols that aren't available in any given module: First
+it searches all the modules that have already been added to the JIT, from the
+most recent to the oldest, to find the newest definition. If no definition is
+found inside the JIT, it falls back to calling "``dlsym("sin")``" on the
+Kaleidoscope process itself. Since "``sin``" is defined within the JIT's
+address space, it simply patches up calls in the module to call the libm
+version of ``sin`` directly. But in some cases this even goes further:
+as sin and cos are names of standard math functions, the constant folder
+will directly evaluate the function calls to the correct result when called
+with constants like in the "``sin(1.0)``" above.
+
+In the future we'll see how tweaking this symbol resolution rule can be used to
+enable all sorts of useful features, from security (restricting the set of
+symbols available to JIT'd code), to dynamic code generation based on symbol
+names, and even lazy compilation.
+
+One immediate benefit of the symbol resolution rule is that we can now extend
+the language by writing arbitrary C++ code to implement operations. For example,
+if we add:
+
+.. code-block:: c++
+
+ #ifdef _WIN32
+ #define DLLEXPORT __declspec(dllexport)
+ #else
+ #define DLLEXPORT
+ #endif
+
+ /// putchard - putchar that takes a double and returns 0.
+ extern "C" DLLEXPORT double putchard(double X) {
+ fputc((char)X, stderr);
+ return 0;
+ }
+
+Note, that for Windows we need to actually export the functions because
+the dynamic symbol loader will use GetProcAddress to find the symbols.
+
+Now we can produce simple output to the console by using things like:
+"``extern putchard(x); putchard(120);``", which prints a lowercase 'x'
+on the console (120 is the ASCII code for 'x'). Similar code could be
+used to implement file I/O, console input, and many other capabilities
+in Kaleidoscope.
+
+This completes the JIT and optimizer chapter of the Kaleidoscope
+tutorial. At this point, we can compile a non-Turing-complete
+programming language, optimize and JIT compile it in a user-driven way.
+Next up we'll look into `extending the language with control flow
+constructs <LangImpl05.html>`_, tackling some interesting LLVM IR issues
+along the way.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the LLVM JIT and optimizer. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core mcjit native` -O3 -o toy
+ # Run
+ ./toy
+
+If you are compiling this on Linux, make sure to add the "-rdynamic"
+option as well. This makes sure that the external functions are resolved
+properly at runtime.
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter4/toy.cpp
+ :language: c++
+
+`Next: Extending the language: control flow <LangImpl05.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl05.rst.txt
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==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl05.rst.txt (added)
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@@ -0,0 +1,814 @@
+==================================================
+Kaleidoscope: Extending the Language: Control Flow
+==================================================
+
+.. contents::
+ :local:
+
+Chapter 5 Introduction
+======================
+
+Welcome to Chapter 5 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. Parts 1-4 described the implementation of
+the simple Kaleidoscope language and included support for generating
+LLVM IR, followed by optimizations and a JIT compiler. Unfortunately, as
+presented, Kaleidoscope is mostly useless: it has no control flow other
+than call and return. This means that you can't have conditional
+branches in the code, significantly limiting its power. In this episode
+of "build that compiler", we'll extend Kaleidoscope to have an
+if/then/else expression plus a simple 'for' loop.
+
+If/Then/Else
+============
+
+Extending Kaleidoscope to support if/then/else is quite straightforward.
+It basically requires adding support for this "new" concept to the
+lexer, parser, AST, and LLVM code emitter. This example is nice, because
+it shows how easy it is to "grow" a language over time, incrementally
+extending it as new ideas are discovered.
+
+Before we get going on "how" we add this extension, let's talk about
+"what" we want. The basic idea is that we want to be able to write this
+sort of thing:
+
+::
+
+ def fib(x)
+ if x < 3 then
+ 1
+ else
+ fib(x-1)+fib(x-2);
+
+In Kaleidoscope, every construct is an expression: there are no
+statements. As such, the if/then/else expression needs to return a value
+like any other. Since we're using a mostly functional form, we'll have
+it evaluate its conditional, then return the 'then' or 'else' value
+based on how the condition was resolved. This is very similar to the C
+"?:" expression.
+
+The semantics of the if/then/else expression is that it evaluates the
+condition to a boolean equality value: 0.0 is considered to be false and
+everything else is considered to be true. If the condition is true, the
+first subexpression is evaluated and returned, if the condition is
+false, the second subexpression is evaluated and returned. Since
+Kaleidoscope allows side-effects, this behavior is important to nail
+down.
+
+Now that we know what we "want", let's break this down into its
+constituent pieces.
+
+Lexer Extensions for If/Then/Else
+---------------------------------
+
+The lexer extensions are straightforward. First we add new enum values
+for the relevant tokens:
+
+.. code-block:: c++
+
+ // control
+ tok_if = -6,
+ tok_then = -7,
+ tok_else = -8,
+
+Once we have that, we recognize the new keywords in the lexer. This is
+pretty simple stuff:
+
+.. code-block:: c++
+
+ ...
+ if (IdentifierStr == "def")
+ return tok_def;
+ if (IdentifierStr == "extern")
+ return tok_extern;
+ if (IdentifierStr == "if")
+ return tok_if;
+ if (IdentifierStr == "then")
+ return tok_then;
+ if (IdentifierStr == "else")
+ return tok_else;
+ return tok_identifier;
+
+AST Extensions for If/Then/Else
+-------------------------------
+
+To represent the new expression we add a new AST node for it:
+
+.. code-block:: c++
+
+ /// IfExprAST - Expression class for if/then/else.
+ class IfExprAST : public ExprAST {
+ std::unique_ptr<ExprAST> Cond, Then, Else;
+
+ public:
+ IfExprAST(std::unique_ptr<ExprAST> Cond, std::unique_ptr<ExprAST> Then,
+ std::unique_ptr<ExprAST> Else)
+ : Cond(std::move(Cond)), Then(std::move(Then)), Else(std::move(Else)) {}
+
+ Value *codegen() override;
+ };
+
+The AST node just has pointers to the various subexpressions.
+
+Parser Extensions for If/Then/Else
+----------------------------------
+
+Now that we have the relevant tokens coming from the lexer and we have
+the AST node to build, our parsing logic is relatively straightforward.
+First we define a new parsing function:
+
+.. code-block:: c++
+
+ /// ifexpr ::= 'if' expression 'then' expression 'else' expression
+ static std::unique_ptr<ExprAST> ParseIfExpr() {
+ getNextToken(); // eat the if.
+
+ // condition.
+ auto Cond = ParseExpression();
+ if (!Cond)
+ return nullptr;
+
+ if (CurTok != tok_then)
+ return LogError("expected then");
+ getNextToken(); // eat the then
+
+ auto Then = ParseExpression();
+ if (!Then)
+ return nullptr;
+
+ if (CurTok != tok_else)
+ return LogError("expected else");
+
+ getNextToken();
+
+ auto Else = ParseExpression();
+ if (!Else)
+ return nullptr;
+
+ return llvm::make_unique<IfExprAST>(std::move(Cond), std::move(Then),
+ std::move(Else));
+ }
+
+Next we hook it up as a primary expression:
+
+.. code-block:: c++
+
+ static std::unique_ptr<ExprAST> ParsePrimary() {
+ switch (CurTok) {
+ default:
+ return LogError("unknown token when expecting an expression");
+ case tok_identifier:
+ return ParseIdentifierExpr();
+ case tok_number:
+ return ParseNumberExpr();
+ case '(':
+ return ParseParenExpr();
+ case tok_if:
+ return ParseIfExpr();
+ }
+ }
+
+LLVM IR for If/Then/Else
+------------------------
+
+Now that we have it parsing and building the AST, the final piece is
+adding LLVM code generation support. This is the most interesting part
+of the if/then/else example, because this is where it starts to
+introduce new concepts. All of the code above has been thoroughly
+described in previous chapters.
+
+To motivate the code we want to produce, let's take a look at a simple
+example. Consider:
+
+::
+
+ extern foo();
+ extern bar();
+ def baz(x) if x then foo() else bar();
+
+If you disable optimizations, the code you'll (soon) get from
+Kaleidoscope looks like this:
+
+.. code-block:: llvm
+
+ declare double @foo()
+
+ declare double @bar()
+
+ define double @baz(double %x) {
+ entry:
+ %ifcond = fcmp one double %x, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then: ; preds = %entry
+ %calltmp = call double @foo()
+ br label %ifcont
+
+ else: ; preds = %entry
+ %calltmp1 = call double @bar()
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ %calltmp, %then ], [ %calltmp1, %else ]
+ ret double %iftmp
+ }
+
+To visualize the control flow graph, you can use a nifty feature of the
+LLVM '`opt <http://llvm.org/cmds/opt.html>`_' tool. If you put this LLVM
+IR into "t.ll" and run "``llvm-as < t.ll | opt -analyze -view-cfg``", `a
+window will pop up <../ProgrammersManual.html#viewing-graphs-while-debugging-code>`_ and you'll
+see this graph:
+
+.. figure:: LangImpl05-cfg.png
+ :align: center
+ :alt: Example CFG
+
+ Example CFG
+
+Another way to get this is to call "``F->viewCFG()``" or
+"``F->viewCFGOnly()``" (where F is a "``Function*``") either by
+inserting actual calls into the code and recompiling or by calling these
+in the debugger. LLVM has many nice features for visualizing various
+graphs.
+
+Getting back to the generated code, it is fairly simple: the entry block
+evaluates the conditional expression ("x" in our case here) and compares
+the result to 0.0 with the "``fcmp one``" instruction ('one' is "Ordered
+and Not Equal"). Based on the result of this expression, the code jumps
+to either the "then" or "else" blocks, which contain the expressions for
+the true/false cases.
+
+Once the then/else blocks are finished executing, they both branch back
+to the 'ifcont' block to execute the code that happens after the
+if/then/else. In this case the only thing left to do is to return to the
+caller of the function. The question then becomes: how does the code
+know which expression to return?
+
+The answer to this question involves an important SSA operation: the
+`Phi
+operation <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+If you're not familiar with SSA, `the wikipedia
+article <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+is a good introduction and there are various other introductions to it
+available on your favorite search engine. The short version is that
+"execution" of the Phi operation requires "remembering" which block
+control came from. The Phi operation takes on the value corresponding to
+the input control block. In this case, if control comes in from the
+"then" block, it gets the value of "calltmp". If control comes from the
+"else" block, it gets the value of "calltmp1".
+
+At this point, you are probably starting to think "Oh no! This means my
+simple and elegant front-end will have to start generating SSA form in
+order to use LLVM!". Fortunately, this is not the case, and we strongly
+advise *not* implementing an SSA construction algorithm in your
+front-end unless there is an amazingly good reason to do so. In
+practice, there are two sorts of values that float around in code
+written for your average imperative programming language that might need
+Phi nodes:
+
+#. Code that involves user variables: ``x = 1; x = x + 1;``
+#. Values that are implicit in the structure of your AST, such as the
+ Phi node in this case.
+
+In `Chapter 7 <LangImpl07.html>`_ of this tutorial ("mutable variables"),
+we'll talk about #1 in depth. For now, just believe me that you don't
+need SSA construction to handle this case. For #2, you have the choice
+of using the techniques that we will describe for #1, or you can insert
+Phi nodes directly, if convenient. In this case, it is really
+easy to generate the Phi node, so we choose to do it directly.
+
+Okay, enough of the motivation and overview, let's generate code!
+
+Code Generation for If/Then/Else
+--------------------------------
+
+In order to generate code for this, we implement the ``codegen`` method
+for ``IfExprAST``:
+
+.. code-block:: c++
+
+ Value *IfExprAST::codegen() {
+ Value *CondV = Cond->codegen();
+ if (!CondV)
+ return nullptr;
+
+ // Convert condition to a bool by comparing non-equal to 0.0.
+ CondV = Builder.CreateFCmpONE(
+ CondV, ConstantFP::get(TheContext, APFloat(0.0)), "ifcond");
+
+This code is straightforward and similar to what we saw before. We emit
+the expression for the condition, then compare that value to zero to get
+a truth value as a 1-bit (bool) value.
+
+.. code-block:: c++
+
+ Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+ // Create blocks for the then and else cases. Insert the 'then' block at the
+ // end of the function.
+ BasicBlock *ThenBB =
+ BasicBlock::Create(TheContext, "then", TheFunction);
+ BasicBlock *ElseBB = BasicBlock::Create(TheContext, "else");
+ BasicBlock *MergeBB = BasicBlock::Create(TheContext, "ifcont");
+
+ Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+
+This code creates the basic blocks that are related to the if/then/else
+statement, and correspond directly to the blocks in the example above.
+The first line gets the current Function object that is being built. It
+gets this by asking the builder for the current BasicBlock, and asking
+that block for its "parent" (the function it is currently embedded
+into).
+
+Once it has that, it creates three blocks. Note that it passes
+"TheFunction" into the constructor for the "then" block. This causes the
+constructor to automatically insert the new block into the end of the
+specified function. The other two blocks are created, but aren't yet
+inserted into the function.
+
+Once the blocks are created, we can emit the conditional branch that
+chooses between them. Note that creating new blocks does not implicitly
+affect the IRBuilder, so it is still inserting into the block that the
+condition went into. Also note that it is creating a branch to the
+"then" block and the "else" block, even though the "else" block isn't
+inserted into the function yet. This is all ok: it is the standard way
+that LLVM supports forward references.
+
+.. code-block:: c++
+
+ // Emit then value.
+ Builder.SetInsertPoint(ThenBB);
+
+ Value *ThenV = Then->codegen();
+ if (!ThenV)
+ return nullptr;
+
+ Builder.CreateBr(MergeBB);
+ // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+ ThenBB = Builder.GetInsertBlock();
+
+After the conditional branch is inserted, we move the builder to start
+inserting into the "then" block. Strictly speaking, this call moves the
+insertion point to be at the end of the specified block. However, since
+the "then" block is empty, it also starts out by inserting at the
+beginning of the block. :)
+
+Once the insertion point is set, we recursively codegen the "then"
+expression from the AST. To finish off the "then" block, we create an
+unconditional branch to the merge block. One interesting (and very
+important) aspect of the LLVM IR is that it `requires all basic blocks
+to be "terminated" <../LangRef.html#functionstructure>`_ with a `control
+flow instruction <../LangRef.html#terminators>`_ such as return or
+branch. This means that all control flow, *including fall throughs* must
+be made explicit in the LLVM IR. If you violate this rule, the verifier
+will emit an error.
+
+The final line here is quite subtle, but is very important. The basic
+issue is that when we create the Phi node in the merge block, we need to
+set up the block/value pairs that indicate how the Phi will work.
+Importantly, the Phi node expects to have an entry for each predecessor
+of the block in the CFG. Why then, are we getting the current block when
+we just set it to ThenBB 5 lines above? The problem is that the "Then"
+expression may actually itself change the block that the Builder is
+emitting into if, for example, it contains a nested "if/then/else"
+expression. Because calling ``codegen()`` recursively could arbitrarily change
+the notion of the current block, we are required to get an up-to-date
+value for code that will set up the Phi node.
+
+.. code-block:: c++
+
+ // Emit else block.
+ TheFunction->getBasicBlockList().push_back(ElseBB);
+ Builder.SetInsertPoint(ElseBB);
+
+ Value *ElseV = Else->codegen();
+ if (!ElseV)
+ return nullptr;
+
+ Builder.CreateBr(MergeBB);
+ // codegen of 'Else' can change the current block, update ElseBB for the PHI.
+ ElseBB = Builder.GetInsertBlock();
+
+Code generation for the 'else' block is basically identical to codegen
+for the 'then' block. The only significant difference is the first line,
+which adds the 'else' block to the function. Recall previously that the
+'else' block was created, but not added to the function. Now that the
+'then' and 'else' blocks are emitted, we can finish up with the merge
+code:
+
+.. code-block:: c++
+
+ // Emit merge block.
+ TheFunction->getBasicBlockList().push_back(MergeBB);
+ Builder.SetInsertPoint(MergeBB);
+ PHINode *PN =
+ Builder.CreatePHI(Type::getDoubleTy(TheContext), 2, "iftmp");
+
+ PN->addIncoming(ThenV, ThenBB);
+ PN->addIncoming(ElseV, ElseBB);
+ return PN;
+ }
+
+The first two lines here are now familiar: the first adds the "merge"
+block to the Function object (it was previously floating, like the else
+block above). The second changes the insertion point so that newly
+created code will go into the "merge" block. Once that is done, we need
+to create the PHI node and set up the block/value pairs for the PHI.
+
+Finally, the CodeGen function returns the phi node as the value computed
+by the if/then/else expression. In our example above, this returned
+value will feed into the code for the top-level function, which will
+create the return instruction.
+
+Overall, we now have the ability to execute conditional code in
+Kaleidoscope. With this extension, Kaleidoscope is a fairly complete
+language that can calculate a wide variety of numeric functions. Next up
+we'll add another useful expression that is familiar from non-functional
+languages...
+
+'for' Loop Expression
+=====================
+
+Now that we know how to add basic control flow constructs to the
+language, we have the tools to add more powerful things. Let's add
+something more aggressive, a 'for' expression:
+
+::
+
+ extern putchard(char);
+ def printstar(n)
+ for i = 1, i < n, 1.0 in
+ putchard(42); # ascii 42 = '*'
+
+ # print 100 '*' characters
+ printstar(100);
+
+This expression defines a new variable ("i" in this case) which iterates
+from a starting value, while the condition ("i < n" in this case) is
+true, incrementing by an optional step value ("1.0" in this case). If
+the step value is omitted, it defaults to 1.0. While the loop is true,
+it executes its body expression. Because we don't have anything better
+to return, we'll just define the loop as always returning 0.0. In the
+future when we have mutable variables, it will get more useful.
+
+As before, let's talk about the changes that we need to Kaleidoscope to
+support this.
+
+Lexer Extensions for the 'for' Loop
+-----------------------------------
+
+The lexer extensions are the same sort of thing as for if/then/else:
+
+.. code-block:: c++
+
+ ... in enum Token ...
+ // control
+ tok_if = -6, tok_then = -7, tok_else = -8,
+ tok_for = -9, tok_in = -10
+
+ ... in gettok ...
+ if (IdentifierStr == "def")
+ return tok_def;
+ if (IdentifierStr == "extern")
+ return tok_extern;
+ if (IdentifierStr == "if")
+ return tok_if;
+ if (IdentifierStr == "then")
+ return tok_then;
+ if (IdentifierStr == "else")
+ return tok_else;
+ if (IdentifierStr == "for")
+ return tok_for;
+ if (IdentifierStr == "in")
+ return tok_in;
+ return tok_identifier;
+
+AST Extensions for the 'for' Loop
+---------------------------------
+
+The AST node is just as simple. It basically boils down to capturing the
+variable name and the constituent expressions in the node.
+
+.. code-block:: c++
+
+ /// ForExprAST - Expression class for for/in.
+ class ForExprAST : public ExprAST {
+ std::string VarName;
+ std::unique_ptr<ExprAST> Start, End, Step, Body;
+
+ public:
+ ForExprAST(const std::string &VarName, std::unique_ptr<ExprAST> Start,
+ std::unique_ptr<ExprAST> End, std::unique_ptr<ExprAST> Step,
+ std::unique_ptr<ExprAST> Body)
+ : VarName(VarName), Start(std::move(Start)), End(std::move(End)),
+ Step(std::move(Step)), Body(std::move(Body)) {}
+
+ Value *codegen() override;
+ };
+
+Parser Extensions for the 'for' Loop
+------------------------------------
+
+The parser code is also fairly standard. The only interesting thing here
+is handling of the optional step value. The parser code handles it by
+checking to see if the second comma is present. If not, it sets the step
+value to null in the AST node:
+
+.. code-block:: c++
+
+ /// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+ static std::unique_ptr<ExprAST> ParseForExpr() {
+ getNextToken(); // eat the for.
+
+ if (CurTok != tok_identifier)
+ return LogError("expected identifier after for");
+
+ std::string IdName = IdentifierStr;
+ getNextToken(); // eat identifier.
+
+ if (CurTok != '=')
+ return LogError("expected '=' after for");
+ getNextToken(); // eat '='.
+
+
+ auto Start = ParseExpression();
+ if (!Start)
+ return nullptr;
+ if (CurTok != ',')
+ return LogError("expected ',' after for start value");
+ getNextToken();
+
+ auto End = ParseExpression();
+ if (!End)
+ return nullptr;
+
+ // The step value is optional.
+ std::unique_ptr<ExprAST> Step;
+ if (CurTok == ',') {
+ getNextToken();
+ Step = ParseExpression();
+ if (!Step)
+ return nullptr;
+ }
+
+ if (CurTok != tok_in)
+ return LogError("expected 'in' after for");
+ getNextToken(); // eat 'in'.
+
+ auto Body = ParseExpression();
+ if (!Body)
+ return nullptr;
+
+ return llvm::make_unique<ForExprAST>(IdName, std::move(Start),
+ std::move(End), std::move(Step),
+ std::move(Body));
+ }
+
+And again we hook it up as a primary expression:
+
+.. code-block:: c++
+
+ static std::unique_ptr<ExprAST> ParsePrimary() {
+ switch (CurTok) {
+ default:
+ return LogError("unknown token when expecting an expression");
+ case tok_identifier:
+ return ParseIdentifierExpr();
+ case tok_number:
+ return ParseNumberExpr();
+ case '(':
+ return ParseParenExpr();
+ case tok_if:
+ return ParseIfExpr();
+ case tok_for:
+ return ParseForExpr();
+ }
+ }
+
+LLVM IR for the 'for' Loop
+--------------------------
+
+Now we get to the good part: the LLVM IR we want to generate for this
+thing. With the simple example above, we get this LLVM IR (note that
+this dump is generated with optimizations disabled for clarity):
+
+.. code-block:: llvm
+
+ declare double @putchard(double)
+
+ define double @printstar(double %n) {
+ entry:
+ ; initial value = 1.0 (inlined into phi)
+ br label %loop
+
+ loop: ; preds = %loop, %entry
+ %i = phi double [ 1.000000e+00, %entry ], [ %nextvar, %loop ]
+ ; body
+ %calltmp = call double @putchard(double 4.200000e+01)
+ ; increment
+ %nextvar = fadd double %i, 1.000000e+00
+
+ ; termination test
+ %cmptmp = fcmp ult double %i, %n
+ %booltmp = uitofp i1 %cmptmp to double
+ %loopcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %loopcond, label %loop, label %afterloop
+
+ afterloop: ; preds = %loop
+ ; loop always returns 0.0
+ ret double 0.000000e+00
+ }
+
+This loop contains all the same constructs we saw before: a phi node,
+several expressions, and some basic blocks. Let's see how this fits
+together.
+
+Code Generation for the 'for' Loop
+----------------------------------
+
+The first part of codegen is very simple: we just output the start
+expression for the loop value:
+
+.. code-block:: c++
+
+ Value *ForExprAST::codegen() {
+ // Emit the start code first, without 'variable' in scope.
+ Value *StartVal = Start->codegen();
+ if (!StartVal)
+ return nullptr;
+
+With this out of the way, the next step is to set up the LLVM basic
+block for the start of the loop body. In the case above, the whole loop
+body is one block, but remember that the body code itself could consist
+of multiple blocks (e.g. if it contains an if/then/else or a for/in
+expression).
+
+.. code-block:: c++
+
+ // Make the new basic block for the loop header, inserting after current
+ // block.
+ Function *TheFunction = Builder.GetInsertBlock()->getParent();
+ BasicBlock *PreheaderBB = Builder.GetInsertBlock();
+ BasicBlock *LoopBB =
+ BasicBlock::Create(TheContext, "loop", TheFunction);
+
+ // Insert an explicit fall through from the current block to the LoopBB.
+ Builder.CreateBr(LoopBB);
+
+This code is similar to what we saw for if/then/else. Because we will
+need it to create the Phi node, we remember the block that falls through
+into the loop. Once we have that, we create the actual block that starts
+the loop and create an unconditional branch for the fall-through between
+the two blocks.
+
+.. code-block:: c++
+
+ // Start insertion in LoopBB.
+ Builder.SetInsertPoint(LoopBB);
+
+ // Start the PHI node with an entry for Start.
+ PHINode *Variable = Builder.CreatePHI(Type::getDoubleTy(TheContext),
+ 2, VarName.c_str());
+ Variable->addIncoming(StartVal, PreheaderBB);
+
+Now that the "preheader" for the loop is set up, we switch to emitting
+code for the loop body. To begin with, we move the insertion point and
+create the PHI node for the loop induction variable. Since we already
+know the incoming value for the starting value, we add it to the Phi
+node. Note that the Phi will eventually get a second value for the
+backedge, but we can't set it up yet (because it doesn't exist!).
+
+.. code-block:: c++
+
+ // Within the loop, the variable is defined equal to the PHI node. If it
+ // shadows an existing variable, we have to restore it, so save it now.
+ Value *OldVal = NamedValues[VarName];
+ NamedValues[VarName] = Variable;
+
+ // Emit the body of the loop. This, like any other expr, can change the
+ // current BB. Note that we ignore the value computed by the body, but don't
+ // allow an error.
+ if (!Body->codegen())
+ return nullptr;
+
+Now the code starts to get more interesting. Our 'for' loop introduces a
+new variable to the symbol table. This means that our symbol table can
+now contain either function arguments or loop variables. To handle this,
+before we codegen the body of the loop, we add the loop variable as the
+current value for its name. Note that it is possible that there is a
+variable of the same name in the outer scope. It would be easy to make
+this an error (emit an error and return null if there is already an
+entry for VarName) but we choose to allow shadowing of variables. In
+order to handle this correctly, we remember the Value that we are
+potentially shadowing in ``OldVal`` (which will be null if there is no
+shadowed variable).
+
+Once the loop variable is set into the symbol table, the code
+recursively codegen's the body. This allows the body to use the loop
+variable: any references to it will naturally find it in the symbol
+table.
+
+.. code-block:: c++
+
+ // Emit the step value.
+ Value *StepVal = nullptr;
+ if (Step) {
+ StepVal = Step->codegen();
+ if (!StepVal)
+ return nullptr;
+ } else {
+ // If not specified, use 1.0.
+ StepVal = ConstantFP::get(TheContext, APFloat(1.0));
+ }
+
+ Value *NextVar = Builder.CreateFAdd(Variable, StepVal, "nextvar");
+
+Now that the body is emitted, we compute the next value of the iteration
+variable by adding the step value, or 1.0 if it isn't present.
+'``NextVar``' will be the value of the loop variable on the next
+iteration of the loop.
+
+.. code-block:: c++
+
+ // Compute the end condition.
+ Value *EndCond = End->codegen();
+ if (!EndCond)
+ return nullptr;
+
+ // Convert condition to a bool by comparing non-equal to 0.0.
+ EndCond = Builder.CreateFCmpONE(
+ EndCond, ConstantFP::get(TheContext, APFloat(0.0)), "loopcond");
+
+Finally, we evaluate the exit value of the loop, to determine whether
+the loop should exit. This mirrors the condition evaluation for the
+if/then/else statement.
+
+.. code-block:: c++
+
+ // Create the "after loop" block and insert it.
+ BasicBlock *LoopEndBB = Builder.GetInsertBlock();
+ BasicBlock *AfterBB =
+ BasicBlock::Create(TheContext, "afterloop", TheFunction);
+
+ // Insert the conditional branch into the end of LoopEndBB.
+ Builder.CreateCondBr(EndCond, LoopBB, AfterBB);
+
+ // Any new code will be inserted in AfterBB.
+ Builder.SetInsertPoint(AfterBB);
+
+With the code for the body of the loop complete, we just need to finish
+up the control flow for it. This code remembers the end block (for the
+phi node), then creates the block for the loop exit ("afterloop"). Based
+on the value of the exit condition, it creates a conditional branch that
+chooses between executing the loop again and exiting the loop. Any
+future code is emitted in the "afterloop" block, so it sets the
+insertion position to it.
+
+.. code-block:: c++
+
+ // Add a new entry to the PHI node for the backedge.
+ Variable->addIncoming(NextVar, LoopEndBB);
+
+ // Restore the unshadowed variable.
+ if (OldVal)
+ NamedValues[VarName] = OldVal;
+ else
+ NamedValues.erase(VarName);
+
+ // for expr always returns 0.0.
+ return Constant::getNullValue(Type::getDoubleTy(TheContext));
+ }
+
+The final code handles various cleanups: now that we have the "NextVar"
+value, we can add the incoming value to the loop PHI node. After that,
+we remove the loop variable from the symbol table, so that it isn't in
+scope after the for loop. Finally, code generation of the for loop
+always returns 0.0, so that is what we return from
+``ForExprAST::codegen()``.
+
+With this, we conclude the "adding control flow to Kaleidoscope" chapter
+of the tutorial. In this chapter we added two control flow constructs,
+and used them to motivate a couple of aspects of the LLVM IR that are
+important for front-end implementors to know. In the next chapter of our
+saga, we will get a bit crazier and add `user-defined
+operators <LangImpl06.html>`_ to our poor innocent language.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the if/then/else and for expressions. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core mcjit native` -O3 -o toy
+ # Run
+ ./toy
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter5/toy.cpp
+ :language: c++
+
+`Next: Extending the language: user-defined operators <LangImpl06.html>`_
+
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+============================================================
+Kaleidoscope: Extending the Language: User-defined Operators
+============================================================
+
+.. contents::
+ :local:
+
+Chapter 6 Introduction
+======================
+
+Welcome to Chapter 6 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. At this point in our tutorial, we now
+have a fully functional language that is fairly minimal, but also
+useful. There is still one big problem with it, however. Our language
+doesn't have many useful operators (like division, logical negation, or
+even any comparisons besides less-than).
+
+This chapter of the tutorial takes a wild digression into adding
+user-defined operators to the simple and beautiful Kaleidoscope
+language. This digression now gives us a simple and ugly language in
+some ways, but also a powerful one at the same time. One of the great
+things about creating your own language is that you get to decide what
+is good or bad. In this tutorial we'll assume that it is okay to use
+this as a way to show some interesting parsing techniques.
+
+At the end of this tutorial, we'll run through an example Kaleidoscope
+application that `renders the Mandelbrot set <#kicking-the-tires>`_. This gives an
+example of what you can build with Kaleidoscope and its feature set.
+
+User-defined Operators: the Idea
+================================
+
+The "operator overloading" that we will add to Kaleidoscope is more
+general than in languages like C++. In C++, you are only allowed to
+redefine existing operators: you can't programmatically change the
+grammar, introduce new operators, change precedence levels, etc. In this
+chapter, we will add this capability to Kaleidoscope, which will let the
+user round out the set of operators that are supported.
+
+The point of going into user-defined operators in a tutorial like this
+is to show the power and flexibility of using a hand-written parser.
+Thus far, the parser we have been implementing uses recursive descent
+for most parts of the grammar and operator precedence parsing for the
+expressions. See `Chapter 2 <LangImpl02.html>`_ for details. By
+using operator precedence parsing, it is very easy to allow
+the programmer to introduce new operators into the grammar: the grammar
+is dynamically extensible as the JIT runs.
+
+The two specific features we'll add are programmable unary operators
+(right now, Kaleidoscope has no unary operators at all) as well as
+binary operators. An example of this is:
+
+::
+
+ # Logical unary not.
+ def unary!(v)
+ if v then
+ 0
+ else
+ 1;
+
+ # Define > with the same precedence as <.
+ def binary> 10 (LHS RHS)
+ RHS < LHS;
+
+ # Binary "logical or", (note that it does not "short circuit")
+ def binary| 5 (LHS RHS)
+ if LHS then
+ 1
+ else if RHS then
+ 1
+ else
+ 0;
+
+ # Define = with slightly lower precedence than relationals.
+ def binary= 9 (LHS RHS)
+ !(LHS < RHS | LHS > RHS);
+
+Many languages aspire to being able to implement their standard runtime
+library in the language itself. In Kaleidoscope, we can implement
+significant parts of the language in the library!
+
+We will break down implementation of these features into two parts:
+implementing support for user-defined binary operators and adding unary
+operators.
+
+User-defined Binary Operators
+=============================
+
+Adding support for user-defined binary operators is pretty simple with
+our current framework. We'll first add support for the unary/binary
+keywords:
+
+.. code-block:: c++
+
+ enum Token {
+ ...
+ // operators
+ tok_binary = -11,
+ tok_unary = -12
+ };
+ ...
+ static int gettok() {
+ ...
+ if (IdentifierStr == "for")
+ return tok_for;
+ if (IdentifierStr == "in")
+ return tok_in;
+ if (IdentifierStr == "binary")
+ return tok_binary;
+ if (IdentifierStr == "unary")
+ return tok_unary;
+ return tok_identifier;
+
+This just adds lexer support for the unary and binary keywords, like we
+did in `previous chapters <LangImpl5.html#lexer-extensions-for-if-then-else>`_. One nice thing
+about our current AST, is that we represent binary operators with full
+generalisation by using their ASCII code as the opcode. For our extended
+operators, we'll use this same representation, so we don't need any new
+AST or parser support.
+
+On the other hand, we have to be able to represent the definitions of
+these new operators, in the "def binary\| 5" part of the function
+definition. In our grammar so far, the "name" for the function
+definition is parsed as the "prototype" production and into the
+``PrototypeAST`` AST node. To represent our new user-defined operators
+as prototypes, we have to extend the ``PrototypeAST`` AST node like
+this:
+
+.. code-block:: c++
+
+ /// PrototypeAST - This class represents the "prototype" for a function,
+ /// which captures its argument names as well as if it is an operator.
+ class PrototypeAST {
+ std::string Name;
+ std::vector<std::string> Args;
+ bool IsOperator;
+ unsigned Precedence; // Precedence if a binary op.
+
+ public:
+ PrototypeAST(const std::string &name, std::vector<std::string> Args,
+ bool IsOperator = false, unsigned Prec = 0)
+ : Name(name), Args(std::move(Args)), IsOperator(IsOperator),
+ Precedence(Prec) {}
+
+ Function *codegen();
+ const std::string &getName() const { return Name; }
+
+ bool isUnaryOp() const { return IsOperator && Args.size() == 1; }
+ bool isBinaryOp() const { return IsOperator && Args.size() == 2; }
+
+ char getOperatorName() const {
+ assert(isUnaryOp() || isBinaryOp());
+ return Name[Name.size() - 1];
+ }
+
+ unsigned getBinaryPrecedence() const { return Precedence; }
+ };
+
+Basically, in addition to knowing a name for the prototype, we now keep
+track of whether it was an operator, and if it was, what precedence
+level the operator is at. The precedence is only used for binary
+operators (as you'll see below, it just doesn't apply for unary
+operators). Now that we have a way to represent the prototype for a
+user-defined operator, we need to parse it:
+
+.. code-block:: c++
+
+ /// prototype
+ /// ::= id '(' id* ')'
+ /// ::= binary LETTER number? (id, id)
+ static std::unique_ptr<PrototypeAST> ParsePrototype() {
+ std::string FnName;
+
+ unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+ unsigned BinaryPrecedence = 30;
+
+ switch (CurTok) {
+ default:
+ return LogErrorP("Expected function name in prototype");
+ case tok_identifier:
+ FnName = IdentifierStr;
+ Kind = 0;
+ getNextToken();
+ break;
+ case tok_binary:
+ getNextToken();
+ if (!isascii(CurTok))
+ return LogErrorP("Expected binary operator");
+ FnName = "binary";
+ FnName += (char)CurTok;
+ Kind = 2;
+ getNextToken();
+
+ // Read the precedence if present.
+ if (CurTok == tok_number) {
+ if (NumVal < 1 || NumVal > 100)
+ return LogErrorP("Invalid precedence: must be 1..100");
+ BinaryPrecedence = (unsigned)NumVal;
+ getNextToken();
+ }
+ break;
+ }
+
+ if (CurTok != '(')
+ return LogErrorP("Expected '(' in prototype");
+
+ std::vector<std::string> ArgNames;
+ while (getNextToken() == tok_identifier)
+ ArgNames.push_back(IdentifierStr);
+ if (CurTok != ')')
+ return LogErrorP("Expected ')' in prototype");
+
+ // success.
+ getNextToken(); // eat ')'.
+
+ // Verify right number of names for operator.
+ if (Kind && ArgNames.size() != Kind)
+ return LogErrorP("Invalid number of operands for operator");
+
+ return llvm::make_unique<PrototypeAST>(FnName, std::move(ArgNames), Kind != 0,
+ BinaryPrecedence);
+ }
+
+This is all fairly straightforward parsing code, and we have already
+seen a lot of similar code in the past. One interesting part about the
+code above is the couple lines that set up ``FnName`` for binary
+operators. This builds names like "binary@" for a newly defined "@"
+operator. It then takes advantage of the fact that symbol names in the
+LLVM symbol table are allowed to have any character in them, including
+embedded nul characters.
+
+The next interesting thing to add, is codegen support for these binary
+operators. Given our current structure, this is a simple addition of a
+default case for our existing binary operator node:
+
+.. code-block:: c++
+
+ Value *BinaryExprAST::codegen() {
+ Value *L = LHS->codegen();
+ Value *R = RHS->codegen();
+ if (!L || !R)
+ return nullptr;
+
+ switch (Op) {
+ case '+':
+ return Builder.CreateFAdd(L, R, "addtmp");
+ case '-':
+ return Builder.CreateFSub(L, R, "subtmp");
+ case '*':
+ return Builder.CreateFMul(L, R, "multmp");
+ case '<':
+ L = Builder.CreateFCmpULT(L, R, "cmptmp");
+ // Convert bool 0/1 to double 0.0 or 1.0
+ return Builder.CreateUIToFP(L, Type::getDoubleTy(TheContext),
+ "booltmp");
+ default:
+ break;
+ }
+
+ // If it wasn't a builtin binary operator, it must be a user defined one. Emit
+ // a call to it.
+ Function *F = getFunction(std::string("binary") + Op);
+ assert(F && "binary operator not found!");
+
+ Value *Ops[2] = { L, R };
+ return Builder.CreateCall(F, Ops, "binop");
+ }
+
+As you can see above, the new code is actually really simple. It just
+does a lookup for the appropriate operator in the symbol table and
+generates a function call to it. Since user-defined operators are just
+built as normal functions (because the "prototype" boils down to a
+function with the right name) everything falls into place.
+
+The final piece of code we are missing, is a bit of top-level magic:
+
+.. code-block:: c++
+
+ Function *FunctionAST::codegen() {
+ // Transfer ownership of the prototype to the FunctionProtos map, but keep a
+ // reference to it for use below.
+ auto &P = *Proto;
+ FunctionProtos[Proto->getName()] = std::move(Proto);
+ Function *TheFunction = getFunction(P.getName());
+ if (!TheFunction)
+ return nullptr;
+
+ // If this is an operator, install it.
+ if (P.isBinaryOp())
+ BinopPrecedence[P.getOperatorName()] = P.getBinaryPrecedence();
+
+ // Create a new basic block to start insertion into.
+ BasicBlock *BB = BasicBlock::Create(TheContext, "entry", TheFunction);
+ ...
+
+Basically, before codegening a function, if it is a user-defined
+operator, we register it in the precedence table. This allows the binary
+operator parsing logic we already have in place to handle it. Since we
+are working on a fully-general operator precedence parser, this is all
+we need to do to "extend the grammar".
+
+Now we have useful user-defined binary operators. This builds a lot on
+the previous framework we built for other operators. Adding unary
+operators is a bit more challenging, because we don't have any framework
+for it yet - let's see what it takes.
+
+User-defined Unary Operators
+============================
+
+Since we don't currently support unary operators in the Kaleidoscope
+language, we'll need to add everything to support them. Above, we added
+simple support for the 'unary' keyword to the lexer. In addition to
+that, we need an AST node:
+
+.. code-block:: c++
+
+ /// UnaryExprAST - Expression class for a unary operator.
+ class UnaryExprAST : public ExprAST {
+ char Opcode;
+ std::unique_ptr<ExprAST> Operand;
+
+ public:
+ UnaryExprAST(char Opcode, std::unique_ptr<ExprAST> Operand)
+ : Opcode(Opcode), Operand(std::move(Operand)) {}
+
+ Value *codegen() override;
+ };
+
+This AST node is very simple and obvious by now. It directly mirrors the
+binary operator AST node, except that it only has one child. With this,
+we need to add the parsing logic. Parsing a unary operator is pretty
+simple: we'll add a new function to do it:
+
+.. code-block:: c++
+
+ /// unary
+ /// ::= primary
+ /// ::= '!' unary
+ static std::unique_ptr<ExprAST> ParseUnary() {
+ // If the current token is not an operator, it must be a primary expr.
+ if (!isascii(CurTok) || CurTok == '(' || CurTok == ',')
+ return ParsePrimary();
+
+ // If this is a unary operator, read it.
+ int Opc = CurTok;
+ getNextToken();
+ if (auto Operand = ParseUnary())
+ return llvm::make_unique<UnaryExprAST>(Opc, std::move(Operand));
+ return nullptr;
+ }
+
+The grammar we add is pretty straightforward here. If we see a unary
+operator when parsing a primary operator, we eat the operator as a
+prefix and parse the remaining piece as another unary operator. This
+allows us to handle multiple unary operators (e.g. "!!x"). Note that
+unary operators can't have ambiguous parses like binary operators can,
+so there is no need for precedence information.
+
+The problem with this function, is that we need to call ParseUnary from
+somewhere. To do this, we change previous callers of ParsePrimary to
+call ParseUnary instead:
+
+.. code-block:: c++
+
+ /// binoprhs
+ /// ::= ('+' unary)*
+ static std::unique_ptr<ExprAST> ParseBinOpRHS(int ExprPrec,
+ std::unique_ptr<ExprAST> LHS) {
+ ...
+ // Parse the unary expression after the binary operator.
+ auto RHS = ParseUnary();
+ if (!RHS)
+ return nullptr;
+ ...
+ }
+ /// expression
+ /// ::= unary binoprhs
+ ///
+ static std::unique_ptr<ExprAST> ParseExpression() {
+ auto LHS = ParseUnary();
+ if (!LHS)
+ return nullptr;
+
+ return ParseBinOpRHS(0, std::move(LHS));
+ }
+
+With these two simple changes, we are now able to parse unary operators
+and build the AST for them. Next up, we need to add parser support for
+prototypes, to parse the unary operator prototype. We extend the binary
+operator code above with:
+
+.. code-block:: c++
+
+ /// prototype
+ /// ::= id '(' id* ')'
+ /// ::= binary LETTER number? (id, id)
+ /// ::= unary LETTER (id)
+ static std::unique_ptr<PrototypeAST> ParsePrototype() {
+ std::string FnName;
+
+ unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+ unsigned BinaryPrecedence = 30;
+
+ switch (CurTok) {
+ default:
+ return LogErrorP("Expected function name in prototype");
+ case tok_identifier:
+ FnName = IdentifierStr;
+ Kind = 0;
+ getNextToken();
+ break;
+ case tok_unary:
+ getNextToken();
+ if (!isascii(CurTok))
+ return LogErrorP("Expected unary operator");
+ FnName = "unary";
+ FnName += (char)CurTok;
+ Kind = 1;
+ getNextToken();
+ break;
+ case tok_binary:
+ ...
+
+As with binary operators, we name unary operators with a name that
+includes the operator character. This assists us at code generation
+time. Speaking of, the final piece we need to add is codegen support for
+unary operators. It looks like this:
+
+.. code-block:: c++
+
+ Value *UnaryExprAST::codegen() {
+ Value *OperandV = Operand->codegen();
+ if (!OperandV)
+ return nullptr;
+
+ Function *F = getFunction(std::string("unary") + Opcode);
+ if (!F)
+ return LogErrorV("Unknown unary operator");
+
+ return Builder.CreateCall(F, OperandV, "unop");
+ }
+
+This code is similar to, but simpler than, the code for binary
+operators. It is simpler primarily because it doesn't need to handle any
+predefined operators.
+
+Kicking the Tires
+=================
+
+It is somewhat hard to believe, but with a few simple extensions we've
+covered in the last chapters, we have grown a real-ish language. With
+this, we can do a lot of interesting things, including I/O, math, and a
+bunch of other things. For example, we can now add a nice sequencing
+operator (printd is defined to print out the specified value and a
+newline):
+
+::
+
+ ready> extern printd(x);
+ Read extern:
+ declare double @printd(double)
+
+ ready> def binary : 1 (x y) 0; # Low-precedence operator that ignores operands.
+ ...
+ ready> printd(123) : printd(456) : printd(789);
+ 123.000000
+ 456.000000
+ 789.000000
+ Evaluated to 0.000000
+
+We can also define a bunch of other "primitive" operations, such as:
+
+::
+
+ # Logical unary not.
+ def unary!(v)
+ if v then
+ 0
+ else
+ 1;
+
+ # Unary negate.
+ def unary-(v)
+ 0-v;
+
+ # Define > with the same precedence as <.
+ def binary> 10 (LHS RHS)
+ RHS < LHS;
+
+ # Binary logical or, which does not short circuit.
+ def binary| 5 (LHS RHS)
+ if LHS then
+ 1
+ else if RHS then
+ 1
+ else
+ 0;
+
+ # Binary logical and, which does not short circuit.
+ def binary& 6 (LHS RHS)
+ if !LHS then
+ 0
+ else
+ !!RHS;
+
+ # Define = with slightly lower precedence than relationals.
+ def binary = 9 (LHS RHS)
+ !(LHS < RHS | LHS > RHS);
+
+ # Define ':' for sequencing: as a low-precedence operator that ignores operands
+ # and just returns the RHS.
+ def binary : 1 (x y) y;
+
+Given the previous if/then/else support, we can also define interesting
+functions for I/O. For example, the following prints out a character
+whose "density" reflects the value passed in: the lower the value, the
+denser the character:
+
+::
+
+ ready> extern putchard(char);
+ ...
+ ready> def printdensity(d)
+ if d > 8 then
+ putchard(32) # ' '
+ else if d > 4 then
+ putchard(46) # '.'
+ else if d > 2 then
+ putchard(43) # '+'
+ else
+ putchard(42); # '*'
+ ...
+ ready> printdensity(1): printdensity(2): printdensity(3):
+ printdensity(4): printdensity(5): printdensity(9):
+ putchard(10);
+ **++.
+ Evaluated to 0.000000
+
+Based on these simple primitive operations, we can start to define more
+interesting things. For example, here's a little function that determines
+the number of iterations it takes for a certain function in the complex
+plane to diverge:
+
+::
+
+ # Determine whether the specific location diverges.
+ # Solve for z = z^2 + c in the complex plane.
+ def mandelconverger(real imag iters creal cimag)
+ if iters > 255 | (real*real + imag*imag > 4) then
+ iters
+ else
+ mandelconverger(real*real - imag*imag + creal,
+ 2*real*imag + cimag,
+ iters+1, creal, cimag);
+
+ # Return the number of iterations required for the iteration to escape
+ def mandelconverge(real imag)
+ mandelconverger(real, imag, 0, real, imag);
+
+This "``z = z2 + c``" function is a beautiful little creature that is
+the basis for computation of the `Mandelbrot
+Set <http://en.wikipedia.org/wiki/Mandelbrot_set>`_. Our
+``mandelconverge`` function returns the number of iterations that it
+takes for a complex orbit to escape, saturating to 255. This is not a
+very useful function by itself, but if you plot its value over a
+two-dimensional plane, you can see the Mandelbrot set. Given that we are
+limited to using putchard here, our amazing graphical output is limited,
+but we can whip together something using the density plotter above:
+
+::
+
+ # Compute and plot the mandelbrot set with the specified 2 dimensional range
+ # info.
+ def mandelhelp(xmin xmax xstep ymin ymax ystep)
+ for y = ymin, y < ymax, ystep in (
+ (for x = xmin, x < xmax, xstep in
+ printdensity(mandelconverge(x,y)))
+ : putchard(10)
+ )
+
+ # mandel - This is a convenient helper function for plotting the mandelbrot set
+ # from the specified position with the specified Magnification.
+ def mandel(realstart imagstart realmag imagmag)
+ mandelhelp(realstart, realstart+realmag*78, realmag,
+ imagstart, imagstart+imagmag*40, imagmag);
+
+Given this, we can try plotting out the mandelbrot set! Lets try it out:
+
+::
+
+ ready> mandel(-2.3, -1.3, 0.05, 0.07);
+ *******************************+++++++++++*************************************
+ *************************+++++++++++++++++++++++*******************************
+ **********************+++++++++++++++++++++++++++++****************************
+ *******************+++++++++++++++++++++.. ...++++++++*************************
+ *****************++++++++++++++++++++++.... ...+++++++++***********************
+ ***************+++++++++++++++++++++++..... ...+++++++++*********************
+ **************+++++++++++++++++++++++.... ....+++++++++********************
+ *************++++++++++++++++++++++...... .....++++++++*******************
+ ************+++++++++++++++++++++....... .......+++++++******************
+ ***********+++++++++++++++++++.... ... .+++++++*****************
+ **********+++++++++++++++++....... .+++++++****************
+ *********++++++++++++++........... ...+++++++***************
+ ********++++++++++++............ ...++++++++**************
+ ********++++++++++... .......... .++++++++**************
+ *******+++++++++..... .+++++++++*************
+ *******++++++++...... ..+++++++++*************
+ *******++++++....... ..+++++++++*************
+ *******+++++...... ..+++++++++*************
+ *******.... .... ...+++++++++*************
+ *******.... . ...+++++++++*************
+ *******+++++...... ...+++++++++*************
+ *******++++++....... ..+++++++++*************
+ *******++++++++...... .+++++++++*************
+ *******+++++++++..... ..+++++++++*************
+ ********++++++++++... .......... .++++++++**************
+ ********++++++++++++............ ...++++++++**************
+ *********++++++++++++++.......... ...+++++++***************
+ **********++++++++++++++++........ .+++++++****************
+ **********++++++++++++++++++++.... ... ..+++++++****************
+ ***********++++++++++++++++++++++....... .......++++++++*****************
+ ************+++++++++++++++++++++++...... ......++++++++******************
+ **************+++++++++++++++++++++++.... ....++++++++********************
+ ***************+++++++++++++++++++++++..... ...+++++++++*********************
+ *****************++++++++++++++++++++++.... ...++++++++***********************
+ *******************+++++++++++++++++++++......++++++++*************************
+ *********************++++++++++++++++++++++.++++++++***************************
+ *************************+++++++++++++++++++++++*******************************
+ ******************************+++++++++++++************************************
+ *******************************************************************************
+ *******************************************************************************
+ *******************************************************************************
+ Evaluated to 0.000000
+ ready> mandel(-2, -1, 0.02, 0.04);
+ **************************+++++++++++++++++++++++++++++++++++++++++++++++++++++
+ ***********************++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ *********************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
+ *******************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++...
+ *****************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.....
+ ***************++++++++++++++++++++++++++++++++++++++++++++++++++++++++........
+ **************++++++++++++++++++++++++++++++++++++++++++++++++++++++...........
+ ************+++++++++++++++++++++++++++++++++++++++++++++++++++++..............
+ ***********++++++++++++++++++++++++++++++++++++++++++++++++++........ .
+ **********++++++++++++++++++++++++++++++++++++++++++++++.............
+ ********+++++++++++++++++++++++++++++++++++++++++++..................
+ *******+++++++++++++++++++++++++++++++++++++++.......................
+ ******+++++++++++++++++++++++++++++++++++...........................
+ *****++++++++++++++++++++++++++++++++............................
+ *****++++++++++++++++++++++++++++...............................
+ ****++++++++++++++++++++++++++...... .........................
+ ***++++++++++++++++++++++++......... ...... ...........
+ ***++++++++++++++++++++++............
+ **+++++++++++++++++++++..............
+ **+++++++++++++++++++................
+ *++++++++++++++++++.................
+ *++++++++++++++++............ ...
+ *++++++++++++++..............
+ *+++....++++................
+ *.......... ...........
+ *
+ *.......... ...........
+ *+++....++++................
+ *++++++++++++++..............
+ *++++++++++++++++............ ...
+ *++++++++++++++++++.................
+ **+++++++++++++++++++................
+ **+++++++++++++++++++++..............
+ ***++++++++++++++++++++++............
+ ***++++++++++++++++++++++++......... ...... ...........
+ ****++++++++++++++++++++++++++...... .........................
+ *****++++++++++++++++++++++++++++...............................
+ *****++++++++++++++++++++++++++++++++............................
+ ******+++++++++++++++++++++++++++++++++++...........................
+ *******+++++++++++++++++++++++++++++++++++++++.......................
+ ********+++++++++++++++++++++++++++++++++++++++++++..................
+ Evaluated to 0.000000
+ ready> mandel(-0.9, -1.4, 0.02, 0.03);
+ *******************************************************************************
+ *******************************************************************************
+ *******************************************************************************
+ **********+++++++++++++++++++++************************************************
+ *+++++++++++++++++++++++++++++++++++++++***************************************
+ +++++++++++++++++++++++++++++++++++++++++++++**********************************
+ ++++++++++++++++++++++++++++++++++++++++++++++++++*****************************
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++*************************
+ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++**********************
+ +++++++++++++++++++++++++++++++++.........++++++++++++++++++*******************
+ +++++++++++++++++++++++++++++++.... ......+++++++++++++++++++****************
+ +++++++++++++++++++++++++++++....... ........+++++++++++++++++++**************
+ ++++++++++++++++++++++++++++........ ........++++++++++++++++++++************
+ +++++++++++++++++++++++++++......... .. ...+++++++++++++++++++++**********
+ ++++++++++++++++++++++++++........... ....++++++++++++++++++++++********
+ ++++++++++++++++++++++++............. .......++++++++++++++++++++++******
+ +++++++++++++++++++++++............. ........+++++++++++++++++++++++****
+ ++++++++++++++++++++++........... ..........++++++++++++++++++++++***
+ ++++++++++++++++++++........... .........++++++++++++++++++++++*
+ ++++++++++++++++++............ ...........++++++++++++++++++++
+ ++++++++++++++++............... .............++++++++++++++++++
+ ++++++++++++++................. ...............++++++++++++++++
+ ++++++++++++.................. .................++++++++++++++
+ +++++++++.................. .................+++++++++++++
+ ++++++........ . ......... ..++++++++++++
+ ++............ ...... ....++++++++++
+ .............. ...++++++++++
+ .............. ....+++++++++
+ .............. .....++++++++
+ ............. ......++++++++
+ ........... .......++++++++
+ ......... ........+++++++
+ ......... ........+++++++
+ ......... ....+++++++
+ ........ ...+++++++
+ ....... ...+++++++
+ ....+++++++
+ .....+++++++
+ ....+++++++
+ ....+++++++
+ ....+++++++
+ Evaluated to 0.000000
+ ready> ^D
+
+At this point, you may be starting to realize that Kaleidoscope is a
+real and powerful language. It may not be self-similar :), but it can be
+used to plot things that are!
+
+With this, we conclude the "adding user-defined operators" chapter of
+the tutorial. We have successfully augmented our language, adding the
+ability to extend the language in the library, and we have shown how
+this can be used to build a simple but interesting end-user application
+in Kaleidoscope. At this point, Kaleidoscope can build a variety of
+applications that are functional and can call functions with
+side-effects, but it can't actually define and mutate a variable itself.
+
+Strikingly, variable mutation is an important feature of some languages,
+and it is not at all obvious how to `add support for mutable
+variables <LangImpl07.html>`_ without having to add an "SSA construction"
+phase to your front-end. In the next chapter, we will describe how you
+can add variable mutation without building SSA in your front-end.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the support for user-defined operators. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core mcjit native` -O3 -o toy
+ # Run
+ ./toy
+
+On some platforms, you will need to specify -rdynamic or
+-Wl,--export-dynamic when linking. This ensures that symbols defined in
+the main executable are exported to the dynamic linker and so are
+available for symbol resolution at run time. This is not needed if you
+compile your support code into a shared library, although doing that
+will cause problems on Windows.
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter6/toy.cpp
+ :language: c++
+
+`Next: Extending the language: mutable variables / SSA
+construction <LangImpl07.html>`_
+
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+=======================================================
+Kaleidoscope: Extending the Language: Mutable Variables
+=======================================================
+
+.. contents::
+ :local:
+
+Chapter 7 Introduction
+======================
+
+Welcome to Chapter 7 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In chapters 1 through 6, we've built a
+very respectable, albeit simple, `functional programming
+language <http://en.wikipedia.org/wiki/Functional_programming>`_. In our
+journey, we learned some parsing techniques, how to build and represent
+an AST, how to build LLVM IR, and how to optimize the resultant code as
+well as JIT compile it.
+
+While Kaleidoscope is interesting as a functional language, the fact
+that it is functional makes it "too easy" to generate LLVM IR for it. In
+particular, a functional language makes it very easy to build LLVM IR
+directly in `SSA
+form <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+Since LLVM requires that the input code be in SSA form, this is a very
+nice property and it is often unclear to newcomers how to generate code
+for an imperative language with mutable variables.
+
+The short (and happy) summary of this chapter is that there is no need
+for your front-end to build SSA form: LLVM provides highly tuned and
+well tested support for this, though the way it works is a bit
+unexpected for some.
+
+Why is this a hard problem?
+===========================
+
+To understand why mutable variables cause complexities in SSA
+construction, consider this extremely simple C example:
+
+.. code-block:: c
+
+ int G, H;
+ int test(_Bool Condition) {
+ int X;
+ if (Condition)
+ X = G;
+ else
+ X = H;
+ return X;
+ }
+
+In this case, we have the variable "X", whose value depends on the path
+executed in the program. Because there are two different possible values
+for X before the return instruction, a PHI node is inserted to merge the
+two values. The LLVM IR that we want for this example looks like this:
+
+.. code-block:: llvm
+
+ @G = weak global i32 0 ; type of @G is i32*
+ @H = weak global i32 0 ; type of @H is i32*
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ br label %cond_next
+
+ cond_next:
+ %X.2 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+ ret i32 %X.2
+ }
+
+In this example, the loads from the G and H global variables are
+explicit in the LLVM IR, and they live in the then/else branches of the
+if statement (cond\_true/cond\_false). In order to merge the incoming
+values, the X.2 phi node in the cond\_next block selects the right value
+to use based on where control flow is coming from: if control flow comes
+from the cond\_false block, X.2 gets the value of X.1. Alternatively, if
+control flow comes from cond\_true, it gets the value of X.0. The intent
+of this chapter is not to explain the details of SSA form. For more
+information, see one of the many `online
+references <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+
+The question for this article is "who places the phi nodes when lowering
+assignments to mutable variables?". The issue here is that LLVM
+*requires* that its IR be in SSA form: there is no "non-ssa" mode for
+it. However, SSA construction requires non-trivial algorithms and data
+structures, so it is inconvenient and wasteful for every front-end to
+have to reproduce this logic.
+
+Memory in LLVM
+==============
+
+The 'trick' here is that while LLVM does require all register values to
+be in SSA form, it does not require (or permit) memory objects to be in
+SSA form. In the example above, note that the loads from G and H are
+direct accesses to G and H: they are not renamed or versioned. This
+differs from some other compiler systems, which do try to version memory
+objects. In LLVM, instead of encoding dataflow analysis of memory into
+the LLVM IR, it is handled with `Analysis
+Passes <../WritingAnLLVMPass.html>`_ which are computed on demand.
+
+With this in mind, the high-level idea is that we want to make a stack
+variable (which lives in memory, because it is on the stack) for each
+mutable object in a function. To take advantage of this trick, we need
+to talk about how LLVM represents stack variables.
+
+In LLVM, all memory accesses are explicit with load/store instructions,
+and it is carefully designed not to have (or need) an "address-of"
+operator. Notice how the type of the @G/@H global variables is actually
+"i32\*" even though the variable is defined as "i32". What this means is
+that @G defines *space* for an i32 in the global data area, but its
+*name* actually refers to the address for that space. Stack variables
+work the same way, except that instead of being declared with global
+variable definitions, they are declared with the `LLVM alloca
+instruction <../LangRef.html#alloca-instruction>`_:
+
+.. code-block:: llvm
+
+ define i32 @example() {
+ entry:
+ %X = alloca i32 ; type of %X is i32*.
+ ...
+ %tmp = load i32* %X ; load the stack value %X from the stack.
+ %tmp2 = add i32 %tmp, 1 ; increment it
+ store i32 %tmp2, i32* %X ; store it back
+ ...
+
+This code shows an example of how you can declare and manipulate a stack
+variable in the LLVM IR. Stack memory allocated with the alloca
+instruction is fully general: you can pass the address of the stack slot
+to functions, you can store it in other variables, etc. In our example
+above, we could rewrite the example to use the alloca technique to avoid
+using a PHI node:
+
+.. code-block:: llvm
+
+ @G = weak global i32 0 ; type of @G is i32*
+ @H = weak global i32 0 ; type of @H is i32*
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ %X = alloca i32 ; type of %X is i32*.
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ store i32 %X.0, i32* %X ; Update X
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ store i32 %X.1, i32* %X ; Update X
+ br label %cond_next
+
+ cond_next:
+ %X.2 = load i32* %X ; Read X
+ ret i32 %X.2
+ }
+
+With this, we have discovered a way to handle arbitrary mutable
+variables without the need to create Phi nodes at all:
+
+#. Each mutable variable becomes a stack allocation.
+#. Each read of the variable becomes a load from the stack.
+#. Each update of the variable becomes a store to the stack.
+#. Taking the address of a variable just uses the stack address
+ directly.
+
+While this solution has solved our immediate problem, it introduced
+another one: we have now apparently introduced a lot of stack traffic
+for very simple and common operations, a major performance problem.
+Fortunately for us, the LLVM optimizer has a highly-tuned optimization
+pass named "mem2reg" that handles this case, promoting allocas like this
+into SSA registers, inserting Phi nodes as appropriate. If you run this
+example through the pass, for example, you'll get:
+
+.. code-block:: bash
+
+ $ llvm-as < example.ll | opt -mem2reg | llvm-dis
+ @G = weak global i32 0
+ @H = weak global i32 0
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ br label %cond_next
+
+ cond_next:
+ %X.01 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+ ret i32 %X.01
+ }
+
+The mem2reg pass implements the standard "iterated dominance frontier"
+algorithm for constructing SSA form and has a number of optimizations
+that speed up (very common) degenerate cases. The mem2reg optimization
+pass is the answer to dealing with mutable variables, and we highly
+recommend that you depend on it. Note that mem2reg only works on
+variables in certain circumstances:
+
+#. mem2reg is alloca-driven: it looks for allocas and if it can handle
+ them, it promotes them. It does not apply to global variables or heap
+ allocations.
+#. mem2reg only looks for alloca instructions in the entry block of the
+ function. Being in the entry block guarantees that the alloca is only
+ executed once, which makes analysis simpler.
+#. mem2reg only promotes allocas whose uses are direct loads and stores.
+ If the address of the stack object is passed to a function, or if any
+ funny pointer arithmetic is involved, the alloca will not be
+ promoted.
+#. mem2reg only works on allocas of `first
+ class <../LangRef.html#first-class-types>`_ values (such as pointers,
+ scalars and vectors), and only if the array size of the allocation is
+ 1 (or missing in the .ll file). mem2reg is not capable of promoting
+ structs or arrays to registers. Note that the "sroa" pass is
+ more powerful and can promote structs, "unions", and arrays in many
+ cases.
+
+All of these properties are easy to satisfy for most imperative
+languages, and we'll illustrate it below with Kaleidoscope. The final
+question you may be asking is: should I bother with this nonsense for my
+front-end? Wouldn't it be better if I just did SSA construction
+directly, avoiding use of the mem2reg optimization pass? In short, we
+strongly recommend that you use this technique for building SSA form,
+unless there is an extremely good reason not to. Using this technique
+is:
+
+- Proven and well tested: clang uses this technique
+ for local mutable variables. As such, the most common clients of LLVM
+ are using this to handle a bulk of their variables. You can be sure
+ that bugs are found fast and fixed early.
+- Extremely Fast: mem2reg has a number of special cases that make it
+ fast in common cases as well as fully general. For example, it has
+ fast-paths for variables that are only used in a single block,
+ variables that only have one assignment point, good heuristics to
+ avoid insertion of unneeded phi nodes, etc.
+- Needed for debug info generation: `Debug information in
+ LLVM <../SourceLevelDebugging.html>`_ relies on having the address of
+ the variable exposed so that debug info can be attached to it. This
+ technique dovetails very naturally with this style of debug info.
+
+If nothing else, this makes it much easier to get your front-end up and
+running, and is very simple to implement. Let's extend Kaleidoscope with
+mutable variables now!
+
+Mutable Variables in Kaleidoscope
+=================================
+
+Now that we know the sort of problem we want to tackle, let's see what
+this looks like in the context of our little Kaleidoscope language.
+We're going to add two features:
+
+#. The ability to mutate variables with the '=' operator.
+#. The ability to define new variables.
+
+While the first item is really what this is about, we only have
+variables for incoming arguments as well as for induction variables, and
+redefining those only goes so far :). Also, the ability to define new
+variables is a useful thing regardless of whether you will be mutating
+them. Here's a motivating example that shows how we could use these:
+
+::
+
+ # Define ':' for sequencing: as a low-precedence operator that ignores operands
+ # and just returns the RHS.
+ def binary : 1 (x y) y;
+
+ # Recursive fib, we could do this before.
+ def fib(x)
+ if (x < 3) then
+ 1
+ else
+ fib(x-1)+fib(x-2);
+
+ # Iterative fib.
+ def fibi(x)
+ var a = 1, b = 1, c in
+ (for i = 3, i < x in
+ c = a + b :
+ a = b :
+ b = c) :
+ b;
+
+ # Call it.
+ fibi(10);
+
+In order to mutate variables, we have to change our existing variables
+to use the "alloca trick". Once we have that, we'll add our new
+operator, then extend Kaleidoscope to support new variable definitions.
+
+Adjusting Existing Variables for Mutation
+=========================================
+
+The symbol table in Kaleidoscope is managed at code generation time by
+the '``NamedValues``' map. This map currently keeps track of the LLVM
+"Value\*" that holds the double value for the named variable. In order
+to support mutation, we need to change this slightly, so that
+``NamedValues`` holds the *memory location* of the variable in question.
+Note that this change is a refactoring: it changes the structure of the
+code, but does not (by itself) change the behavior of the compiler. All
+of these changes are isolated in the Kaleidoscope code generator.
+
+At this point in Kaleidoscope's development, it only supports variables
+for two things: incoming arguments to functions and the induction
+variable of 'for' loops. For consistency, we'll allow mutation of these
+variables in addition to other user-defined variables. This means that
+these will both need memory locations.
+
+To start our transformation of Kaleidoscope, we'll change the
+NamedValues map so that it maps to AllocaInst\* instead of Value\*. Once
+we do this, the C++ compiler will tell us what parts of the code we need
+to update:
+
+.. code-block:: c++
+
+ static std::map<std::string, AllocaInst*> NamedValues;
+
+Also, since we will need to create these allocas, we'll use a helper
+function that ensures that the allocas are created in the entry block of
+the function:
+
+.. code-block:: c++
+
+ /// CreateEntryBlockAlloca - Create an alloca instruction in the entry block of
+ /// the function. This is used for mutable variables etc.
+ static AllocaInst *CreateEntryBlockAlloca(Function *TheFunction,
+ const std::string &VarName) {
+ IRBuilder<> TmpB(&TheFunction->getEntryBlock(),
+ TheFunction->getEntryBlock().begin());
+ return TmpB.CreateAlloca(Type::getDoubleTy(TheContext), 0,
+ VarName.c_str());
+ }
+
+This funny looking code creates an IRBuilder object that is pointing at
+the first instruction (.begin()) of the entry block. It then creates an
+alloca with the expected name and returns it. Because all values in
+Kaleidoscope are doubles, there is no need to pass in a type to use.
+
+With this in place, the first functionality change we want to make belongs to
+variable references. In our new scheme, variables live on the stack, so
+code generating a reference to them actually needs to produce a load
+from the stack slot:
+
+.. code-block:: c++
+
+ Value *VariableExprAST::codegen() {
+ // Look this variable up in the function.
+ Value *V = NamedValues[Name];
+ if (!V)
+ return LogErrorV("Unknown variable name");
+
+ // Load the value.
+ return Builder.CreateLoad(V, Name.c_str());
+ }
+
+As you can see, this is pretty straightforward. Now we need to update
+the things that define the variables to set up the alloca. We'll start
+with ``ForExprAST::codegen()`` (see the `full code listing <#id1>`_ for
+the unabridged code):
+
+.. code-block:: c++
+
+ Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+ // Create an alloca for the variable in the entry block.
+ AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+
+ // Emit the start code first, without 'variable' in scope.
+ Value *StartVal = Start->codegen();
+ if (!StartVal)
+ return nullptr;
+
+ // Store the value into the alloca.
+ Builder.CreateStore(StartVal, Alloca);
+ ...
+
+ // Compute the end condition.
+ Value *EndCond = End->codegen();
+ if (!EndCond)
+ return nullptr;
+
+ // Reload, increment, and restore the alloca. This handles the case where
+ // the body of the loop mutates the variable.
+ Value *CurVar = Builder.CreateLoad(Alloca);
+ Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
+ Builder.CreateStore(NextVar, Alloca);
+ ...
+
+This code is virtually identical to the code `before we allowed mutable
+variables <LangImpl5.html#code-generation-for-the-for-loop>`_. The big difference is that we
+no longer have to construct a PHI node, and we use load/store to access
+the variable as needed.
+
+To support mutable argument variables, we need to also make allocas for
+them. The code for this is also pretty simple:
+
+.. code-block:: c++
+
+ Function *FunctionAST::codegen() {
+ ...
+ Builder.SetInsertPoint(BB);
+
+ // Record the function arguments in the NamedValues map.
+ NamedValues.clear();
+ for (auto &Arg : TheFunction->args()) {
+ // Create an alloca for this variable.
+ AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Arg.getName());
+
+ // Store the initial value into the alloca.
+ Builder.CreateStore(&Arg, Alloca);
+
+ // Add arguments to variable symbol table.
+ NamedValues[Arg.getName()] = Alloca;
+ }
+
+ if (Value *RetVal = Body->codegen()) {
+ ...
+
+For each argument, we make an alloca, store the input value to the
+function into the alloca, and register the alloca as the memory location
+for the argument. This method gets invoked by ``FunctionAST::codegen()``
+right after it sets up the entry block for the function.
+
+The final missing piece is adding the mem2reg pass, which allows us to
+get good codegen once again:
+
+.. code-block:: c++
+
+ // Promote allocas to registers.
+ TheFPM->add(createPromoteMemoryToRegisterPass());
+ // Do simple "peephole" optimizations and bit-twiddling optzns.
+ TheFPM->add(createInstructionCombiningPass());
+ // Reassociate expressions.
+ TheFPM->add(createReassociatePass());
+ ...
+
+It is interesting to see what the code looks like before and after the
+mem2reg optimization runs. For example, this is the before/after code
+for our recursive fib function. Before the optimization:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %x1 = alloca double
+ store double %x, double* %x1
+ %x2 = load double, double* %x1
+ %cmptmp = fcmp ult double %x2, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then: ; preds = %entry
+ br label %ifcont
+
+ else: ; preds = %entry
+ %x3 = load double, double* %x1
+ %subtmp = fsub double %x3, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %x4 = load double, double* %x1
+ %subtmp5 = fsub double %x4, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+ ret double %iftmp
+ }
+
+Here there is only one variable (x, the input argument) but you can
+still see the extremely simple-minded code generation strategy we are
+using. In the entry block, an alloca is created, and the initial input
+value is stored into it. Each reference to the variable does a reload
+from the stack. Also, note that we didn't modify the if/then/else
+expression, so it still inserts a PHI node. While we could make an
+alloca for it, it is actually easier to create a PHI node for it, so we
+still just make the PHI.
+
+Here is the code after the mem2reg pass runs:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %cmptmp = fcmp ult double %x, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then:
+ br label %ifcont
+
+ else:
+ %subtmp = fsub double %x, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %subtmp5 = fsub double %x, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+ ret double %iftmp
+ }
+
+This is a trivial case for mem2reg, since there are no redefinitions of
+the variable. The point of showing this is to calm your tension about
+inserting such blatent inefficiencies :).
+
+After the rest of the optimizers run, we get:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %cmptmp = fcmp ult double %x, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp ueq double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %else, label %ifcont
+
+ else:
+ %subtmp = fsub double %x, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %subtmp5 = fsub double %x, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ ret double %addtmp
+
+ ifcont:
+ ret double 1.000000e+00
+ }
+
+Here we see that the simplifycfg pass decided to clone the return
+instruction into the end of the 'else' block. This allowed it to
+eliminate some branches and the PHI node.
+
+Now that all symbol table references are updated to use stack variables,
+we'll add the assignment operator.
+
+New Assignment Operator
+=======================
+
+With our current framework, adding a new assignment operator is really
+simple. We will parse it just like any other binary operator, but handle
+it internally (instead of allowing the user to define it). The first
+step is to set a precedence:
+
+.. code-block:: c++
+
+ int main() {
+ // Install standard binary operators.
+ // 1 is lowest precedence.
+ BinopPrecedence['='] = 2;
+ BinopPrecedence['<'] = 10;
+ BinopPrecedence['+'] = 20;
+ BinopPrecedence['-'] = 20;
+
+Now that the parser knows the precedence of the binary operator, it
+takes care of all the parsing and AST generation. We just need to
+implement codegen for the assignment operator. This looks like:
+
+.. code-block:: c++
+
+ Value *BinaryExprAST::codegen() {
+ // Special case '=' because we don't want to emit the LHS as an expression.
+ if (Op == '=') {
+ // Assignment requires the LHS to be an identifier.
+ VariableExprAST *LHSE = dynamic_cast<VariableExprAST*>(LHS.get());
+ if (!LHSE)
+ return LogErrorV("destination of '=' must be a variable");
+
+Unlike the rest of the binary operators, our assignment operator doesn't
+follow the "emit LHS, emit RHS, do computation" model. As such, it is
+handled as a special case before the other binary operators are handled.
+The other strange thing is that it requires the LHS to be a variable. It
+is invalid to have "(x+1) = expr" - only things like "x = expr" are
+allowed.
+
+.. code-block:: c++
+
+ // Codegen the RHS.
+ Value *Val = RHS->codegen();
+ if (!Val)
+ return nullptr;
+
+ // Look up the name.
+ Value *Variable = NamedValues[LHSE->getName()];
+ if (!Variable)
+ return LogErrorV("Unknown variable name");
+
+ Builder.CreateStore(Val, Variable);
+ return Val;
+ }
+ ...
+
+Once we have the variable, codegen'ing the assignment is
+straightforward: we emit the RHS of the assignment, create a store, and
+return the computed value. Returning a value allows for chained
+assignments like "X = (Y = Z)".
+
+Now that we have an assignment operator, we can mutate loop variables
+and arguments. For example, we can now run code like this:
+
+::
+
+ # Function to print a double.
+ extern printd(x);
+
+ # Define ':' for sequencing: as a low-precedence operator that ignores operands
+ # and just returns the RHS.
+ def binary : 1 (x y) y;
+
+ def test(x)
+ printd(x) :
+ x = 4 :
+ printd(x);
+
+ test(123);
+
+When run, this example prints "123" and then "4", showing that we did
+actually mutate the value! Okay, we have now officially implemented our
+goal: getting this to work requires SSA construction in the general
+case. However, to be really useful, we want the ability to define our
+own local variables, let's add this next!
+
+User-defined Local Variables
+============================
+
+Adding var/in is just like any other extension we made to
+Kaleidoscope: we extend the lexer, the parser, the AST and the code
+generator. The first step for adding our new 'var/in' construct is to
+extend the lexer. As before, this is pretty trivial, the code looks like
+this:
+
+.. code-block:: c++
+
+ enum Token {
+ ...
+ // var definition
+ tok_var = -13
+ ...
+ }
+ ...
+ static int gettok() {
+ ...
+ if (IdentifierStr == "in")
+ return tok_in;
+ if (IdentifierStr == "binary")
+ return tok_binary;
+ if (IdentifierStr == "unary")
+ return tok_unary;
+ if (IdentifierStr == "var")
+ return tok_var;
+ return tok_identifier;
+ ...
+
+The next step is to define the AST node that we will construct. For
+var/in, it looks like this:
+
+.. code-block:: c++
+
+ /// VarExprAST - Expression class for var/in
+ class VarExprAST : public ExprAST {
+ std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
+ std::unique_ptr<ExprAST> Body;
+
+ public:
+ VarExprAST(std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames,
+ std::unique_ptr<ExprAST> Body)
+ : VarNames(std::move(VarNames)), Body(std::move(Body)) {}
+
+ Value *codegen() override;
+ };
+
+var/in allows a list of names to be defined all at once, and each name
+can optionally have an initializer value. As such, we capture this
+information in the VarNames vector. Also, var/in has a body, this body
+is allowed to access the variables defined by the var/in.
+
+With this in place, we can define the parser pieces. The first thing we
+do is add it as a primary expression:
+
+.. code-block:: c++
+
+ /// primary
+ /// ::= identifierexpr
+ /// ::= numberexpr
+ /// ::= parenexpr
+ /// ::= ifexpr
+ /// ::= forexpr
+ /// ::= varexpr
+ static std::unique_ptr<ExprAST> ParsePrimary() {
+ switch (CurTok) {
+ default:
+ return LogError("unknown token when expecting an expression");
+ case tok_identifier:
+ return ParseIdentifierExpr();
+ case tok_number:
+ return ParseNumberExpr();
+ case '(':
+ return ParseParenExpr();
+ case tok_if:
+ return ParseIfExpr();
+ case tok_for:
+ return ParseForExpr();
+ case tok_var:
+ return ParseVarExpr();
+ }
+ }
+
+Next we define ParseVarExpr:
+
+.. code-block:: c++
+
+ /// varexpr ::= 'var' identifier ('=' expression)?
+ // (',' identifier ('=' expression)?)* 'in' expression
+ static std::unique_ptr<ExprAST> ParseVarExpr() {
+ getNextToken(); // eat the var.
+
+ std::vector<std::pair<std::string, std::unique_ptr<ExprAST>>> VarNames;
+
+ // At least one variable name is required.
+ if (CurTok != tok_identifier)
+ return LogError("expected identifier after var");
+
+The first part of this code parses the list of identifier/expr pairs
+into the local ``VarNames`` vector.
+
+.. code-block:: c++
+
+ while (1) {
+ std::string Name = IdentifierStr;
+ getNextToken(); // eat identifier.
+
+ // Read the optional initializer.
+ std::unique_ptr<ExprAST> Init;
+ if (CurTok == '=') {
+ getNextToken(); // eat the '='.
+
+ Init = ParseExpression();
+ if (!Init) return nullptr;
+ }
+
+ VarNames.push_back(std::make_pair(Name, std::move(Init)));
+
+ // End of var list, exit loop.
+ if (CurTok != ',') break;
+ getNextToken(); // eat the ','.
+
+ if (CurTok != tok_identifier)
+ return LogError("expected identifier list after var");
+ }
+
+Once all the variables are parsed, we then parse the body and create the
+AST node:
+
+.. code-block:: c++
+
+ // At this point, we have to have 'in'.
+ if (CurTok != tok_in)
+ return LogError("expected 'in' keyword after 'var'");
+ getNextToken(); // eat 'in'.
+
+ auto Body = ParseExpression();
+ if (!Body)
+ return nullptr;
+
+ return llvm::make_unique<VarExprAST>(std::move(VarNames),
+ std::move(Body));
+ }
+
+Now that we can parse and represent the code, we need to support
+emission of LLVM IR for it. This code starts out with:
+
+.. code-block:: c++
+
+ Value *VarExprAST::codegen() {
+ std::vector<AllocaInst *> OldBindings;
+
+ Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+ // Register all variables and emit their initializer.
+ for (unsigned i = 0, e = VarNames.size(); i != e; ++i) {
+ const std::string &VarName = VarNames[i].first;
+ ExprAST *Init = VarNames[i].second.get();
+
+Basically it loops over all the variables, installing them one at a
+time. For each variable we put into the symbol table, we remember the
+previous value that we replace in OldBindings.
+
+.. code-block:: c++
+
+ // Emit the initializer before adding the variable to scope, this prevents
+ // the initializer from referencing the variable itself, and permits stuff
+ // like this:
+ // var a = 1 in
+ // var a = a in ... # refers to outer 'a'.
+ Value *InitVal;
+ if (Init) {
+ InitVal = Init->codegen();
+ if (!InitVal)
+ return nullptr;
+ } else { // If not specified, use 0.0.
+ InitVal = ConstantFP::get(TheContext, APFloat(0.0));
+ }
+
+ AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+ Builder.CreateStore(InitVal, Alloca);
+
+ // Remember the old variable binding so that we can restore the binding when
+ // we unrecurse.
+ OldBindings.push_back(NamedValues[VarName]);
+
+ // Remember this binding.
+ NamedValues[VarName] = Alloca;
+ }
+
+There are more comments here than code. The basic idea is that we emit
+the initializer, create the alloca, then update the symbol table to
+point to it. Once all the variables are installed in the symbol table,
+we evaluate the body of the var/in expression:
+
+.. code-block:: c++
+
+ // Codegen the body, now that all vars are in scope.
+ Value *BodyVal = Body->codegen();
+ if (!BodyVal)
+ return nullptr;
+
+Finally, before returning, we restore the previous variable bindings:
+
+.. code-block:: c++
+
+ // Pop all our variables from scope.
+ for (unsigned i = 0, e = VarNames.size(); i != e; ++i)
+ NamedValues[VarNames[i].first] = OldBindings[i];
+
+ // Return the body computation.
+ return BodyVal;
+ }
+
+The end result of all of this is that we get properly scoped variable
+definitions, and we even (trivially) allow mutation of them :).
+
+With this, we completed what we set out to do. Our nice iterative fib
+example from the intro compiles and runs just fine. The mem2reg pass
+optimizes all of our stack variables into SSA registers, inserting PHI
+nodes where needed, and our front-end remains simple: no "iterated
+dominance frontier" computation anywhere in sight.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+mutable variables and var/in support. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core mcjit native` -O3 -o toy
+ # Run
+ ./toy
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter7/toy.cpp
+ :language: c++
+
+`Next: Compiling to Object Code <LangImpl08.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/LangImpl08.rst.txt
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@@ -0,0 +1,218 @@
+========================================
+ Kaleidoscope: Compiling to Object Code
+========================================
+
+.. contents::
+ :local:
+
+Chapter 8 Introduction
+======================
+
+Welcome to Chapter 8 of the "`Implementing a language with LLVM
+<index.html>`_" tutorial. This chapter describes how to compile our
+language down to object files.
+
+Choosing a target
+=================
+
+LLVM has native support for cross-compilation. You can compile to the
+architecture of your current machine, or just as easily compile for
+other architectures. In this tutorial, we'll target the current
+machine.
+
+To specify the architecture that you want to target, we use a string
+called a "target triple". This takes the form
+``<arch><sub>-<vendor>-<sys>-<abi>`` (see the `cross compilation docs
+<http://clang.llvm.org/docs/CrossCompilation.html#target-triple>`_).
+
+As an example, we can see what clang thinks is our current target
+triple:
+
+::
+
+ $ clang --version | grep Target
+ Target: x86_64-unknown-linux-gnu
+
+Running this command may show something different on your machine as
+you might be using a different architecture or operating system to me.
+
+Fortunately, we don't need to hard-code a target triple to target the
+current machine. LLVM provides ``sys::getDefaultTargetTriple``, which
+returns the target triple of the current machine.
+
+.. code-block:: c++
+
+ auto TargetTriple = sys::getDefaultTargetTriple();
+
+LLVM doesn't require us to link in all the target
+functionality. For example, if we're just using the JIT, we don't need
+the assembly printers. Similarly, if we're only targeting certain
+architectures, we can only link in the functionality for those
+architectures.
+
+For this example, we'll initialize all the targets for emitting object
+code.
+
+.. code-block:: c++
+
+ InitializeAllTargetInfos();
+ InitializeAllTargets();
+ InitializeAllTargetMCs();
+ InitializeAllAsmParsers();
+ InitializeAllAsmPrinters();
+
+We can now use our target triple to get a ``Target``:
+
+.. code-block:: c++
+
+ std::string Error;
+ auto Target = TargetRegistry::lookupTarget(TargetTriple, Error);
+
+ // Print an error and exit if we couldn't find the requested target.
+ // This generally occurs if we've forgotten to initialise the
+ // TargetRegistry or we have a bogus target triple.
+ if (!Target) {
+ errs() << Error;
+ return 1;
+ }
+
+Target Machine
+==============
+
+We will also need a ``TargetMachine``. This class provides a complete
+machine description of the machine we're targeting. If we want to
+target a specific feature (such as SSE) or a specific CPU (such as
+Intel's Sandylake), we do so now.
+
+To see which features and CPUs that LLVM knows about, we can use
+``llc``. For example, let's look at x86:
+
+::
+
+ $ llvm-as < /dev/null | llc -march=x86 -mattr=help
+ Available CPUs for this target:
+
+ amdfam10 - Select the amdfam10 processor.
+ athlon - Select the athlon processor.
+ athlon-4 - Select the athlon-4 processor.
+ ...
+
+ Available features for this target:
+
+ 16bit-mode - 16-bit mode (i8086).
+ 32bit-mode - 32-bit mode (80386).
+ 3dnow - Enable 3DNow! instructions.
+ 3dnowa - Enable 3DNow! Athlon instructions.
+ ...
+
+For our example, we'll use the generic CPU without any additional
+features, options or relocation model.
+
+.. code-block:: c++
+
+ auto CPU = "generic";
+ auto Features = "";
+
+ TargetOptions opt;
+ auto RM = Optional<Reloc::Model>();
+ auto TargetMachine = Target->createTargetMachine(TargetTriple, CPU, Features, opt, RM);
+
+
+Configuring the Module
+======================
+
+We're now ready to configure our module, to specify the target and
+data layout. This isn't strictly necessary, but the `frontend
+performance guide <../Frontend/PerformanceTips.html>`_ recommends
+this. Optimizations benefit from knowing about the target and data
+layout.
+
+.. code-block:: c++
+
+ TheModule->setDataLayout(TargetMachine->createDataLayout());
+ TheModule->setTargetTriple(TargetTriple);
+
+Emit Object Code
+================
+
+We're ready to emit object code! Let's define where we want to write
+our file to:
+
+.. code-block:: c++
+
+ auto Filename = "output.o";
+ std::error_code EC;
+ raw_fd_ostream dest(Filename, EC, sys::fs::F_None);
+
+ if (EC) {
+ errs() << "Could not open file: " << EC.message();
+ return 1;
+ }
+
+Finally, we define a pass that emits object code, then we run that
+pass:
+
+.. code-block:: c++
+
+ legacy::PassManager pass;
+ auto FileType = TargetMachine::CGFT_ObjectFile;
+
+ if (TargetMachine->addPassesToEmitFile(pass, dest, FileType)) {
+ errs() << "TargetMachine can't emit a file of this type";
+ return 1;
+ }
+
+ pass.run(*TheModule);
+ dest.flush();
+
+Putting It All Together
+=======================
+
+Does it work? Let's give it a try. We need to compile our code, but
+note that the arguments to ``llvm-config`` are different to the previous chapters.
+
+::
+
+ $ clang++ -g -O3 toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs all` -o toy
+
+Let's run it, and define a simple ``average`` function. Press Ctrl-D
+when you're done.
+
+::
+
+ $ ./toy
+ ready> def average(x y) (x + y) * 0.5;
+ ^D
+ Wrote output.o
+
+We have an object file! To test it, let's write a simple program and
+link it with our output. Here's the source code:
+
+.. code-block:: c++
+
+ #include <iostream>
+
+ extern "C" {
+ double average(double, double);
+ }
+
+ int main() {
+ std::cout << "average of 3.0 and 4.0: " << average(3.0, 4.0) << std::endl;
+ }
+
+We link our program to output.o and check the result is what we
+expected:
+
+::
+
+ $ clang++ main.cpp output.o -o main
+ $ ./main
+ average of 3.0 and 4.0: 3.5
+
+Full Code Listing
+=================
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter8/toy.cpp
+ :language: c++
+
+`Next: Adding Debug Information <LangImpl09.html>`_
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@@ -0,0 +1,465 @@
+======================================
+Kaleidoscope: Adding Debug Information
+======================================
+
+.. contents::
+ :local:
+
+Chapter 9 Introduction
+======================
+
+Welcome to Chapter 9 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In chapters 1 through 8, we've built a
+decent little programming language with functions and variables.
+What happens if something goes wrong though, how do you debug your
+program?
+
+Source level debugging uses formatted data that helps a debugger
+translate from binary and the state of the machine back to the
+source that the programmer wrote. In LLVM we generally use a format
+called `DWARF <http://dwarfstd.org>`_. DWARF is a compact encoding
+that represents types, source locations, and variable locations.
+
+The short summary of this chapter is that we'll go through the
+various things you have to add to a programming language to
+support debug info, and how you translate that into DWARF.
+
+Caveat: For now we can't debug via the JIT, so we'll need to compile
+our program down to something small and standalone. As part of this
+we'll make a few modifications to the running of the language and
+how programs are compiled. This means that we'll have a source file
+with a simple program written in Kaleidoscope rather than the
+interactive JIT. It does involve a limitation that we can only
+have one "top level" command at a time to reduce the number of
+changes necessary.
+
+Here's the sample program we'll be compiling:
+
+.. code-block:: python
+
+ def fib(x)
+ if x < 3 then
+ 1
+ else
+ fib(x-1)+fib(x-2);
+
+ fib(10)
+
+
+Why is this a hard problem?
+===========================
+
+Debug information is a hard problem for a few different reasons - mostly
+centered around optimized code. First, optimization makes keeping source
+locations more difficult. In LLVM IR we keep the original source location
+for each IR level instruction on the instruction. Optimization passes
+should keep the source locations for newly created instructions, but merged
+instructions only get to keep a single location - this can cause jumping
+around when stepping through optimized programs. Secondly, optimization
+can move variables in ways that are either optimized out, shared in memory
+with other variables, or difficult to track. For the purposes of this
+tutorial we're going to avoid optimization (as you'll see with one of the
+next sets of patches).
+
+Ahead-of-Time Compilation Mode
+==============================
+
+To highlight only the aspects of adding debug information to a source
+language without needing to worry about the complexities of JIT debugging
+we're going to make a few changes to Kaleidoscope to support compiling
+the IR emitted by the front end into a simple standalone program that
+you can execute, debug, and see results.
+
+First we make our anonymous function that contains our top level
+statement be our "main":
+
+.. code-block:: udiff
+
+ - auto Proto = llvm::make_unique<PrototypeAST>("", std::vector<std::string>());
+ + auto Proto = llvm::make_unique<PrototypeAST>("main", std::vector<std::string>());
+
+just with the simple change of giving it a name.
+
+Then we're going to remove the command line code wherever it exists:
+
+.. code-block:: udiff
+
+ @@ -1129,7 +1129,6 @@ static void HandleTopLevelExpression() {
+ /// top ::= definition | external | expression | ';'
+ static void MainLoop() {
+ while (1) {
+ - fprintf(stderr, "ready> ");
+ switch (CurTok) {
+ case tok_eof:
+ return;
+ @@ -1184,7 +1183,6 @@ int main() {
+ BinopPrecedence['*'] = 40; // highest.
+
+ // Prime the first token.
+ - fprintf(stderr, "ready> ");
+ getNextToken();
+
+Lastly we're going to disable all of the optimization passes and the JIT so
+that the only thing that happens after we're done parsing and generating
+code is that the LLVM IR goes to standard error:
+
+.. code-block:: udiff
+
+ @@ -1108,17 +1108,8 @@ static void HandleExtern() {
+ static void HandleTopLevelExpression() {
+ // Evaluate a top-level expression into an anonymous function.
+ if (auto FnAST = ParseTopLevelExpr()) {
+ - if (auto *FnIR = FnAST->codegen()) {
+ - // We're just doing this to make sure it executes.
+ - TheExecutionEngine->finalizeObject();
+ - // JIT the function, returning a function pointer.
+ - void *FPtr = TheExecutionEngine->getPointerToFunction(FnIR);
+ -
+ - // Cast it to the right type (takes no arguments, returns a double) so we
+ - // can call it as a native function.
+ - double (*FP)() = (double (*)())(intptr_t)FPtr;
+ - // Ignore the return value for this.
+ - (void)FP;
+ + if (!F->codegen()) {
+ + fprintf(stderr, "Error generating code for top level expr");
+ }
+ } else {
+ // Skip token for error recovery.
+ @@ -1439,11 +1459,11 @@ int main() {
+ // target lays out data structures.
+ TheModule->setDataLayout(TheExecutionEngine->getDataLayout());
+ OurFPM.add(new DataLayoutPass());
+ +#if 0
+ OurFPM.add(createBasicAliasAnalysisPass());
+ // Promote allocas to registers.
+ OurFPM.add(createPromoteMemoryToRegisterPass());
+ @@ -1218,7 +1210,7 @@ int main() {
+ OurFPM.add(createGVNPass());
+ // Simplify the control flow graph (deleting unreachable blocks, etc).
+ OurFPM.add(createCFGSimplificationPass());
+ -
+ + #endif
+ OurFPM.doInitialization();
+
+ // Set the global so the code gen can use this.
+
+This relatively small set of changes get us to the point that we can compile
+our piece of Kaleidoscope language down to an executable program via this
+command line:
+
+.. code-block:: bash
+
+ Kaleidoscope-Ch9 < fib.ks | & clang -x ir -
+
+which gives an a.out/a.exe in the current working directory.
+
+Compile Unit
+============
+
+The top level container for a section of code in DWARF is a compile unit.
+This contains the type and function data for an individual translation unit
+(read: one file of source code). So the first thing we need to do is
+construct one for our fib.ks file.
+
+DWARF Emission Setup
+====================
+
+Similar to the ``IRBuilder`` class we have a
+`DIBuilder <http://llvm.org/doxygen/classllvm_1_1DIBuilder.html>`_ class
+that helps in constructing debug metadata for an LLVM IR file. It
+corresponds 1:1 similarly to ``IRBuilder`` and LLVM IR, but with nicer names.
+Using it does require that you be more familiar with DWARF terminology than
+you needed to be with ``IRBuilder`` and ``Instruction`` names, but if you
+read through the general documentation on the
+`Metadata Format <http://llvm.org/docs/SourceLevelDebugging.html>`_ it
+should be a little more clear. We'll be using this class to construct all
+of our IR level descriptions. Construction for it takes a module so we
+need to construct it shortly after we construct our module. We've left it
+as a global static variable to make it a bit easier to use.
+
+Next we're going to create a small container to cache some of our frequent
+data. The first will be our compile unit, but we'll also write a bit of
+code for our one type since we won't have to worry about multiple typed
+expressions:
+
+.. code-block:: c++
+
+ static DIBuilder *DBuilder;
+
+ struct DebugInfo {
+ DICompileUnit *TheCU;
+ DIType *DblTy;
+
+ DIType *getDoubleTy();
+ } KSDbgInfo;
+
+ DIType *DebugInfo::getDoubleTy() {
+ if (DblTy)
+ return DblTy;
+
+ DblTy = DBuilder->createBasicType("double", 64, dwarf::DW_ATE_float);
+ return DblTy;
+ }
+
+And then later on in ``main`` when we're constructing our module:
+
+.. code-block:: c++
+
+ DBuilder = new DIBuilder(*TheModule);
+
+ KSDbgInfo.TheCU = DBuilder->createCompileUnit(
+ dwarf::DW_LANG_C, DBuilder->createFile("fib.ks", "."),
+ "Kaleidoscope Compiler", 0, "", 0);
+
+There are a couple of things to note here. First, while we're producing a
+compile unit for a language called Kaleidoscope we used the language
+constant for C. This is because a debugger wouldn't necessarily understand
+the calling conventions or default ABI for a language it doesn't recognize
+and we follow the C ABI in our LLVM code generation so it's the closest
+thing to accurate. This ensures we can actually call functions from the
+debugger and have them execute. Secondly, you'll see the "fib.ks" in the
+call to ``createCompileUnit``. This is a default hard coded value since
+we're using shell redirection to put our source into the Kaleidoscope
+compiler. In a usual front end you'd have an input file name and it would
+go there.
+
+One last thing as part of emitting debug information via DIBuilder is that
+we need to "finalize" the debug information. The reasons are part of the
+underlying API for DIBuilder, but make sure you do this near the end of
+main:
+
+.. code-block:: c++
+
+ DBuilder->finalize();
+
+before you dump out the module.
+
+Functions
+=========
+
+Now that we have our ``Compile Unit`` and our source locations, we can add
+function definitions to the debug info. So in ``PrototypeAST::codegen()`` we
+add a few lines of code to describe a context for our subprogram, in this
+case the "File", and the actual definition of the function itself.
+
+So the context:
+
+.. code-block:: c++
+
+ DIFile *Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
+ KSDbgInfo.TheCU.getDirectory());
+
+giving us an DIFile and asking the ``Compile Unit`` we created above for the
+directory and filename where we are currently. Then, for now, we use some
+source locations of 0 (since our AST doesn't currently have source location
+information) and construct our function definition:
+
+.. code-block:: c++
+
+ DIScope *FContext = Unit;
+ unsigned LineNo = 0;
+ unsigned ScopeLine = 0;
+ DISubprogram *SP = DBuilder->createFunction(
+ FContext, P.getName(), StringRef(), Unit, LineNo,
+ CreateFunctionType(TheFunction->arg_size(), Unit),
+ false /* internal linkage */, true /* definition */, ScopeLine,
+ DINode::FlagPrototyped, false);
+ TheFunction->setSubprogram(SP);
+
+and we now have an DISubprogram that contains a reference to all of our
+metadata for the function.
+
+Source Locations
+================
+
+The most important thing for debug information is accurate source location -
+this makes it possible to map your source code back. We have a problem though,
+Kaleidoscope really doesn't have any source location information in the lexer
+or parser so we'll need to add it.
+
+.. code-block:: c++
+
+ struct SourceLocation {
+ int Line;
+ int Col;
+ };
+ static SourceLocation CurLoc;
+ static SourceLocation LexLoc = {1, 0};
+
+ static int advance() {
+ int LastChar = getchar();
+
+ if (LastChar == '\n' || LastChar == '\r') {
+ LexLoc.Line++;
+ LexLoc.Col = 0;
+ } else
+ LexLoc.Col++;
+ return LastChar;
+ }
+
+In this set of code we've added some functionality on how to keep track of the
+line and column of the "source file". As we lex every token we set our current
+current "lexical location" to the assorted line and column for the beginning
+of the token. We do this by overriding all of the previous calls to
+``getchar()`` with our new ``advance()`` that keeps track of the information
+and then we have added to all of our AST classes a source location:
+
+.. code-block:: c++
+
+ class ExprAST {
+ SourceLocation Loc;
+
+ public:
+ ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
+ virtual ~ExprAST() {}
+ virtual Value* codegen() = 0;
+ int getLine() const { return Loc.Line; }
+ int getCol() const { return Loc.Col; }
+ virtual raw_ostream &dump(raw_ostream &out, int ind) {
+ return out << ':' << getLine() << ':' << getCol() << '\n';
+ }
+
+that we pass down through when we create a new expression:
+
+.. code-block:: c++
+
+ LHS = llvm::make_unique<BinaryExprAST>(BinLoc, BinOp, std::move(LHS),
+ std::move(RHS));
+
+giving us locations for each of our expressions and variables.
+
+To make sure that every instruction gets proper source location information,
+we have to tell ``Builder`` whenever we're at a new source location.
+We use a small helper function for this:
+
+.. code-block:: c++
+
+ void DebugInfo::emitLocation(ExprAST *AST) {
+ DIScope *Scope;
+ if (LexicalBlocks.empty())
+ Scope = TheCU;
+ else
+ Scope = LexicalBlocks.back();
+ Builder.SetCurrentDebugLocation(
+ DebugLoc::get(AST->getLine(), AST->getCol(), Scope));
+ }
+
+This both tells the main ``IRBuilder`` where we are, but also what scope
+we're in. The scope can either be on compile-unit level or be the nearest
+enclosing lexical block like the current function.
+To represent this we create a stack of scopes:
+
+.. code-block:: c++
+
+ std::vector<DIScope *> LexicalBlocks;
+
+and push the scope (function) to the top of the stack when we start
+generating the code for each function:
+
+.. code-block:: c++
+
+ KSDbgInfo.LexicalBlocks.push_back(SP);
+
+Also, we may not forget to pop the scope back off of the scope stack at the
+end of the code generation for the function:
+
+.. code-block:: c++
+
+ // Pop off the lexical block for the function since we added it
+ // unconditionally.
+ KSDbgInfo.LexicalBlocks.pop_back();
+
+Then we make sure to emit the location every time we start to generate code
+for a new AST object:
+
+.. code-block:: c++
+
+ KSDbgInfo.emitLocation(this);
+
+Variables
+=========
+
+Now that we have functions, we need to be able to print out the variables
+we have in scope. Let's get our function arguments set up so we can get
+decent backtraces and see how our functions are being called. It isn't
+a lot of code, and we generally handle it when we're creating the
+argument allocas in ``FunctionAST::codegen``.
+
+.. code-block:: c++
+
+ // Record the function arguments in the NamedValues map.
+ NamedValues.clear();
+ unsigned ArgIdx = 0;
+ for (auto &Arg : TheFunction->args()) {
+ // Create an alloca for this variable.
+ AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, Arg.getName());
+
+ // Create a debug descriptor for the variable.
+ DILocalVariable *D = DBuilder->createParameterVariable(
+ SP, Arg.getName(), ++ArgIdx, Unit, LineNo, KSDbgInfo.getDoubleTy(),
+ true);
+
+ DBuilder->insertDeclare(Alloca, D, DBuilder->createExpression(),
+ DebugLoc::get(LineNo, 0, SP),
+ Builder.GetInsertBlock());
+
+ // Store the initial value into the alloca.
+ Builder.CreateStore(&Arg, Alloca);
+
+ // Add arguments to variable symbol table.
+ NamedValues[Arg.getName()] = Alloca;
+ }
+
+
+Here we're first creating the variable, giving it the scope (``SP``),
+the name, source location, type, and since it's an argument, the argument
+index. Next, we create an ``lvm.dbg.declare`` call to indicate at the IR
+level that we've got a variable in an alloca (and it gives a starting
+location for the variable), and setting a source location for the
+beginning of the scope on the declare.
+
+One interesting thing to note at this point is that various debuggers have
+assumptions based on how code and debug information was generated for them
+in the past. In this case we need to do a little bit of a hack to avoid
+generating line information for the function prologue so that the debugger
+knows to skip over those instructions when setting a breakpoint. So in
+``FunctionAST::CodeGen`` we add some more lines:
+
+.. code-block:: c++
+
+ // Unset the location for the prologue emission (leading instructions with no
+ // location in a function are considered part of the prologue and the debugger
+ // will run past them when breaking on a function)
+ KSDbgInfo.emitLocation(nullptr);
+
+and then emit a new location when we actually start generating code for the
+body of the function:
+
+.. code-block:: c++
+
+ KSDbgInfo.emitLocation(Body.get());
+
+With this we have enough debug information to set breakpoints in functions,
+print out argument variables, and call functions. Not too bad for just a
+few simple lines of code!
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+debug information. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ clang++ -g toy.cpp `llvm-config --cxxflags --ldflags --system-libs --libs core mcjit native` -O3 -o toy
+ # Run
+ ./toy
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter9/toy.cpp
+ :language: c++
+
+`Next: Conclusion and other useful LLVM tidbits <LangImpl10.html>`_
+
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+======================================================
+Kaleidoscope: Conclusion and other useful LLVM tidbits
+======================================================
+
+.. contents::
+ :local:
+
+Tutorial Conclusion
+===================
+
+Welcome to the final chapter of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In the course of this tutorial, we have
+grown our little Kaleidoscope language from being a useless toy, to
+being a semi-interesting (but probably still useless) toy. :)
+
+It is interesting to see how far we've come, and how little code it has
+taken. We built the entire lexer, parser, AST, code generator, an
+interactive run-loop (with a JIT!), and emitted debug information in
+standalone executables - all in under 1000 lines of (non-comment/non-blank)
+code.
+
+Our little language supports a couple of interesting features: it
+supports user defined binary and unary operators, it uses JIT
+compilation for immediate evaluation, and it supports a few control flow
+constructs with SSA construction.
+
+Part of the idea of this tutorial was to show you how easy and fun it
+can be to define, build, and play with languages. Building a compiler
+need not be a scary or mystical process! Now that you've seen some of
+the basics, I strongly encourage you to take the code and hack on it.
+For example, try adding:
+
+- **global variables** - While global variables have questional value
+ in modern software engineering, they are often useful when putting
+ together quick little hacks like the Kaleidoscope compiler itself.
+ Fortunately, our current setup makes it very easy to add global
+ variables: just have value lookup check to see if an unresolved
+ variable is in the global variable symbol table before rejecting it.
+ To create a new global variable, make an instance of the LLVM
+ ``GlobalVariable`` class.
+- **typed variables** - Kaleidoscope currently only supports variables
+ of type double. This gives the language a very nice elegance, because
+ only supporting one type means that you never have to specify types.
+ Different languages have different ways of handling this. The easiest
+ way is to require the user to specify types for every variable
+ definition, and record the type of the variable in the symbol table
+ along with its Value\*.
+- **arrays, structs, vectors, etc** - Once you add types, you can start
+ extending the type system in all sorts of interesting ways. Simple
+ arrays are very easy and are quite useful for many different
+ applications. Adding them is mostly an exercise in learning how the
+ LLVM `getelementptr <../LangRef.html#getelementptr-instruction>`_ instruction
+ works: it is so nifty/unconventional, it `has its own
+ FAQ <../GetElementPtr.html>`_!
+- **standard runtime** - Our current language allows the user to access
+ arbitrary external functions, and we use it for things like "printd"
+ and "putchard". As you extend the language to add higher-level
+ constructs, often these constructs make the most sense if they are
+ lowered to calls into a language-supplied runtime. For example, if
+ you add hash tables to the language, it would probably make sense to
+ add the routines to a runtime, instead of inlining them all the way.
+- **memory management** - Currently we can only access the stack in
+ Kaleidoscope. It would also be useful to be able to allocate heap
+ memory, either with calls to the standard libc malloc/free interface
+ or with a garbage collector. If you would like to use garbage
+ collection, note that LLVM fully supports `Accurate Garbage
+ Collection <../GarbageCollection.html>`_ including algorithms that
+ move objects and need to scan/update the stack.
+- **exception handling support** - LLVM supports generation of `zero
+ cost exceptions <../ExceptionHandling.html>`_ which interoperate with
+ code compiled in other languages. You could also generate code by
+ implicitly making every function return an error value and checking
+ it. You could also make explicit use of setjmp/longjmp. There are
+ many different ways to go here.
+- **object orientation, generics, database access, complex numbers,
+ geometric programming, ...** - Really, there is no end of crazy
+ features that you can add to the language.
+- **unusual domains** - We've been talking about applying LLVM to a
+ domain that many people are interested in: building a compiler for a
+ specific language. However, there are many other domains that can use
+ compiler technology that are not typically considered. For example,
+ LLVM has been used to implement OpenGL graphics acceleration,
+ translate C++ code to ActionScript, and many other cute and clever
+ things. Maybe you will be the first to JIT compile a regular
+ expression interpreter into native code with LLVM?
+
+Have fun - try doing something crazy and unusual. Building a language
+like everyone else always has, is much less fun than trying something a
+little crazy or off the wall and seeing how it turns out. If you get
+stuck or want to talk about it, feel free to email the `llvm-dev mailing
+list <http://lists.llvm.org/mailman/listinfo/llvm-dev>`_: it has lots
+of people who are interested in languages and are often willing to help
+out.
+
+Before we end this tutorial, I want to talk about some "tips and tricks"
+for generating LLVM IR. These are some of the more subtle things that
+may not be obvious, but are very useful if you want to take advantage of
+LLVM's capabilities.
+
+Properties of the LLVM IR
+=========================
+
+We have a couple of common questions about code in the LLVM IR form -
+let's just get these out of the way right now, shall we?
+
+Target Independence
+-------------------
+
+Kaleidoscope is an example of a "portable language": any program written
+in Kaleidoscope will work the same way on any target that it runs on.
+Many other languages have this property, e.g. lisp, java, haskell,
+javascript, python, etc (note that while these languages are portable,
+not all their libraries are).
+
+One nice aspect of LLVM is that it is often capable of preserving target
+independence in the IR: you can take the LLVM IR for a
+Kaleidoscope-compiled program and run it on any target that LLVM
+supports, even emitting C code and compiling that on targets that LLVM
+doesn't support natively. You can trivially tell that the Kaleidoscope
+compiler generates target-independent code because it never queries for
+any target-specific information when generating code.
+
+The fact that LLVM provides a compact, target-independent,
+representation for code gets a lot of people excited. Unfortunately,
+these people are usually thinking about C or a language from the C
+family when they are asking questions about language portability. I say
+"unfortunately", because there is really no way to make (fully general)
+C code portable, other than shipping the source code around (and of
+course, C source code is not actually portable in general either - ever
+port a really old application from 32- to 64-bits?).
+
+The problem with C (again, in its full generality) is that it is heavily
+laden with target specific assumptions. As one simple example, the
+preprocessor often destructively removes target-independence from the
+code when it processes the input text:
+
+.. code-block:: c
+
+ #ifdef __i386__
+ int X = 1;
+ #else
+ int X = 42;
+ #endif
+
+While it is possible to engineer more and more complex solutions to
+problems like this, it cannot be solved in full generality in a way that
+is better than shipping the actual source code.
+
+That said, there are interesting subsets of C that can be made portable.
+If you are willing to fix primitive types to a fixed size (say int =
+32-bits, and long = 64-bits), don't care about ABI compatibility with
+existing binaries, and are willing to give up some other minor features,
+you can have portable code. This can make sense for specialized domains
+such as an in-kernel language.
+
+Safety Guarantees
+-----------------
+
+Many of the languages above are also "safe" languages: it is impossible
+for a program written in Java to corrupt its address space and crash the
+process (assuming the JVM has no bugs). Safety is an interesting
+property that requires a combination of language design, runtime
+support, and often operating system support.
+
+It is certainly possible to implement a safe language in LLVM, but LLVM
+IR does not itself guarantee safety. The LLVM IR allows unsafe pointer
+casts, use after free bugs, buffer over-runs, and a variety of other
+problems. Safety needs to be implemented as a layer on top of LLVM and,
+conveniently, several groups have investigated this. Ask on the `llvm-dev
+mailing list <http://lists.llvm.org/mailman/listinfo/llvm-dev>`_ if
+you are interested in more details.
+
+Language-Specific Optimizations
+-------------------------------
+
+One thing about LLVM that turns off many people is that it does not
+solve all the world's problems in one system (sorry 'world hunger',
+someone else will have to solve you some other day). One specific
+complaint is that people perceive LLVM as being incapable of performing
+high-level language-specific optimization: LLVM "loses too much
+information".
+
+Unfortunately, this is really not the place to give you a full and
+unified version of "Chris Lattner's theory of compiler design". Instead,
+I'll make a few observations:
+
+First, you're right that LLVM does lose information. For example, as of
+this writing, there is no way to distinguish in the LLVM IR whether an
+SSA-value came from a C "int" or a C "long" on an ILP32 machine (other
+than debug info). Both get compiled down to an 'i32' value and the
+information about what it came from is lost. The more general issue
+here, is that the LLVM type system uses "structural equivalence" instead
+of "name equivalence". Another place this surprises people is if you
+have two types in a high-level language that have the same structure
+(e.g. two different structs that have a single int field): these types
+will compile down into a single LLVM type and it will be impossible to
+tell what it came from.
+
+Second, while LLVM does lose information, LLVM is not a fixed target: we
+continue to enhance and improve it in many different ways. In addition
+to adding new features (LLVM did not always support exceptions or debug
+info), we also extend the IR to capture important information for
+optimization (e.g. whether an argument is sign or zero extended,
+information about pointers aliasing, etc). Many of the enhancements are
+user-driven: people want LLVM to include some specific feature, so they
+go ahead and extend it.
+
+Third, it is *possible and easy* to add language-specific optimizations,
+and you have a number of choices in how to do it. As one trivial
+example, it is easy to add language-specific optimization passes that
+"know" things about code compiled for a language. In the case of the C
+family, there is an optimization pass that "knows" about the standard C
+library functions. If you call "exit(0)" in main(), it knows that it is
+safe to optimize that into "return 0;" because C specifies what the
+'exit' function does.
+
+In addition to simple library knowledge, it is possible to embed a
+variety of other language-specific information into the LLVM IR. If you
+have a specific need and run into a wall, please bring the topic up on
+the llvm-dev list. At the very worst, you can always treat LLVM as if it
+were a "dumb code generator" and implement the high-level optimizations
+you desire in your front-end, on the language-specific AST.
+
+Tips and Tricks
+===============
+
+There is a variety of useful tips and tricks that you come to know after
+working on/with LLVM that aren't obvious at first glance. Instead of
+letting everyone rediscover them, this section talks about some of these
+issues.
+
+Implementing portable offsetof/sizeof
+-------------------------------------
+
+One interesting thing that comes up, if you are trying to keep the code
+generated by your compiler "target independent", is that you often need
+to know the size of some LLVM type or the offset of some field in an
+llvm structure. For example, you might need to pass the size of a type
+into a function that allocates memory.
+
+Unfortunately, this can vary widely across targets: for example the
+width of a pointer is trivially target-specific. However, there is a
+`clever way to use the getelementptr
+instruction <http://nondot.org/sabre/LLVMNotes/SizeOf-OffsetOf-VariableSizedStructs.txt>`_
+that allows you to compute this in a portable way.
+
+Garbage Collected Stack Frames
+------------------------------
+
+Some languages want to explicitly manage their stack frames, often so
+that they are garbage collected or to allow easy implementation of
+closures. There are often better ways to implement these features than
+explicit stack frames, but `LLVM does support
+them, <http://nondot.org/sabre/LLVMNotes/ExplicitlyManagedStackFrames.txt>`_
+if you want. It requires your front-end to convert the code into
+`Continuation Passing
+Style <http://en.wikipedia.org/wiki/Continuation-passing_style>`_ and
+the use of tail calls (which LLVM also supports).
+
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+=================================================
+Kaleidoscope: Tutorial Introduction and the Lexer
+=================================================
+
+.. contents::
+ :local:
+
+Tutorial Introduction
+=====================
+
+Welcome to the "Implementing a language with LLVM" tutorial. This
+tutorial runs through the implementation of a simple language, showing
+how fun and easy it can be. This tutorial will get you up and started as
+well as help to build a framework you can extend to other languages. The
+code in this tutorial can also be used as a playground to hack on other
+LLVM specific things.
+
+The goal of this tutorial is to progressively unveil our language,
+describing how it is built up over time. This will let us cover a fairly
+broad range of language design and LLVM-specific usage issues, showing
+and explaining the code for it all along the way, without overwhelming
+you with tons of details up front.
+
+It is useful to point out ahead of time that this tutorial is really
+about teaching compiler techniques and LLVM specifically, *not* about
+teaching modern and sane software engineering principles. In practice,
+this means that we'll take a number of shortcuts to simplify the
+exposition. For example, the code leaks memory, uses global variables
+all over the place, doesn't use nice design patterns like
+`visitors <http://en.wikipedia.org/wiki/Visitor_pattern>`_, etc... but
+it is very simple. If you dig in and use the code as a basis for future
+projects, fixing these deficiencies shouldn't be hard.
+
+I've tried to put this tutorial together in a way that makes chapters
+easy to skip over if you are already familiar with or are uninterested
+in the various pieces. The structure of the tutorial is:
+
+- `Chapter #1 <#language>`_: Introduction to the Kaleidoscope
+ language, and the definition of its Lexer - This shows where we are
+ going and the basic functionality that we want it to do. In order to
+ make this tutorial maximally understandable and hackable, we choose
+ to implement everything in Objective Caml instead of using lexer and
+ parser generators. LLVM obviously works just fine with such tools,
+ feel free to use one if you prefer.
+- `Chapter #2 <OCamlLangImpl2.html>`_: Implementing a Parser and
+ AST - With the lexer in place, we can talk about parsing techniques
+ and basic AST construction. This tutorial describes recursive descent
+ parsing and operator precedence parsing. Nothing in Chapters 1 or 2
+ is LLVM-specific, the code doesn't even link in LLVM at this point.
+ :)
+- `Chapter #3 <OCamlLangImpl3.html>`_: Code generation to LLVM IR -
+ With the AST ready, we can show off how easy generation of LLVM IR
+ really is.
+- `Chapter #4 <OCamlLangImpl4.html>`_: Adding JIT and Optimizer
+ Support - Because a lot of people are interested in using LLVM as a
+ JIT, we'll dive right into it and show you the 3 lines it takes to
+ add JIT support. LLVM is also useful in many other ways, but this is
+ one simple and "sexy" way to shows off its power. :)
+- `Chapter #5 <OCamlLangImpl5.html>`_: Extending the Language:
+ Control Flow - With the language up and running, we show how to
+ extend it with control flow operations (if/then/else and a 'for'
+ loop). This gives us a chance to talk about simple SSA construction
+ and control flow.
+- `Chapter #6 <OCamlLangImpl6.html>`_: Extending the Language:
+ User-defined Operators - This is a silly but fun chapter that talks
+ about extending the language to let the user program define their own
+ arbitrary unary and binary operators (with assignable precedence!).
+ This lets us build a significant piece of the "language" as library
+ routines.
+- `Chapter #7 <OCamlLangImpl7.html>`_: Extending the Language:
+ Mutable Variables - This chapter talks about adding user-defined
+ local variables along with an assignment operator. The interesting
+ part about this is how easy and trivial it is to construct SSA form
+ in LLVM: no, LLVM does *not* require your front-end to construct SSA
+ form!
+- `Chapter #8 <OCamlLangImpl8.html>`_: Conclusion and other useful
+ LLVM tidbits - This chapter wraps up the series by talking about
+ potential ways to extend the language, but also includes a bunch of
+ pointers to info about "special topics" like adding garbage
+ collection support, exceptions, debugging, support for "spaghetti
+ stacks", and a bunch of other tips and tricks.
+
+By the end of the tutorial, we'll have written a bit less than 700 lines
+of non-comment, non-blank, lines of code. With this small amount of
+code, we'll have built up a very reasonable compiler for a non-trivial
+language including a hand-written lexer, parser, AST, as well as code
+generation support with a JIT compiler. While other systems may have
+interesting "hello world" tutorials, I think the breadth of this
+tutorial is a great testament to the strengths of LLVM and why you
+should consider it if you're interested in language or compiler design.
+
+A note about this tutorial: we expect you to extend the language and
+play with it on your own. Take the code and go crazy hacking away at it,
+compilers don't need to be scary creatures - it can be a lot of fun to
+play with languages!
+
+The Basic Language
+==================
+
+This tutorial will be illustrated with a toy language that we'll call
+"`Kaleidoscope <http://en.wikipedia.org/wiki/Kaleidoscope>`_" (derived
+from "meaning beautiful, form, and view"). Kaleidoscope is a procedural
+language that allows you to define functions, use conditionals, math,
+etc. Over the course of the tutorial, we'll extend Kaleidoscope to
+support the if/then/else construct, a for loop, user defined operators,
+JIT compilation with a simple command line interface, etc.
+
+Because we want to keep things simple, the only datatype in Kaleidoscope
+is a 64-bit floating point type (aka 'float' in OCaml parlance). As
+such, all values are implicitly double precision and the language
+doesn't require type declarations. This gives the language a very nice
+and simple syntax. For example, the following simple example computes
+`Fibonacci numbers: <http://en.wikipedia.org/wiki/Fibonacci_number>`_
+
+::
+
+ # Compute the x'th fibonacci number.
+ def fib(x)
+ if x < 3 then
+ 1
+ else
+ fib(x-1)+fib(x-2)
+
+ # This expression will compute the 40th number.
+ fib(40)
+
+We also allow Kaleidoscope to call into standard library functions (the
+LLVM JIT makes this completely trivial). This means that you can use the
+'extern' keyword to define a function before you use it (this is also
+useful for mutually recursive functions). For example:
+
+::
+
+ extern sin(arg);
+ extern cos(arg);
+ extern atan2(arg1 arg2);
+
+ atan2(sin(.4), cos(42))
+
+A more interesting example is included in Chapter 6 where we write a
+little Kaleidoscope application that `displays a Mandelbrot
+Set <OCamlLangImpl6.html#kicking-the-tires>`_ at various levels of magnification.
+
+Lets dive into the implementation of this language!
+
+The Lexer
+=========
+
+When it comes to implementing a language, the first thing needed is the
+ability to process a text file and recognize what it says. The
+traditional way to do this is to use a
+"`lexer <http://en.wikipedia.org/wiki/Lexical_analysis>`_" (aka
+'scanner') to break the input up into "tokens". Each token returned by
+the lexer includes a token code and potentially some metadata (e.g. the
+numeric value of a number). First, we define the possibilities:
+
+.. code-block:: ocaml
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+Each token returned by our lexer will be one of the token variant
+values. An unknown character like '+' will be returned as
+``Token.Kwd '+'``. If the curr token is an identifier, the value will be
+``Token.Ident s``. If the current token is a numeric literal (like 1.0),
+the value will be ``Token.Number 1.0``.
+
+The actual implementation of the lexer is a collection of functions
+driven by a function named ``Lexer.lex``. The ``Lexer.lex`` function is
+called to return the next token from standard input. We will use
+`Camlp4 <http://caml.inria.fr/pub/docs/manual-camlp4/index.html>`_ to
+simplify the tokenization of the standard input. Its definition starts
+as:
+
+.. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+``Lexer.lex`` works by recursing over a ``char Stream.t`` to read
+characters one at a time from the standard input. It eats them as it
+recognizes them and stores them in a ``Token.token`` variant. The
+first thing that it has to do is ignore whitespace between tokens. This
+is accomplished with the recursive call above.
+
+The next thing ``Lexer.lex`` needs to do is recognize identifiers and
+specific keywords like "def". Kaleidoscope does this with a pattern
+match and a helper function.
+
+.. code-block:: ocaml
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ ...
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+Numeric values are similar:
+
+.. code-block:: ocaml
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ ...
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+This is all pretty straight-forward code for processing input. When
+reading a numeric value from input, we use the ocaml ``float_of_string``
+function to convert it to a numeric value that we store in
+``Token.Number``. Note that this isn't doing sufficient error checking:
+it will raise ``Failure`` if the string "1.23.45.67". Feel free to
+extend it :). Next we handle comments:
+
+.. code-block:: ocaml
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ ...
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+We handle comments by skipping to the end of the line and then return
+the next token. Finally, if the input doesn't match one of the above
+cases, it is either an operator character like '+' or the end of the
+file. These are handled with this code:
+
+.. code-block:: ocaml
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+With this, we have the complete lexer for the basic Kaleidoscope
+language (the `full code listing <OCamlLangImpl2.html#full-code-listing>`_ for the
+Lexer is available in the `next chapter <OCamlLangImpl2.html>`_ of the
+tutorial). Next we'll `build a simple parser that uses this to build an
+Abstract Syntax Tree <OCamlLangImpl2.html>`_. When we have that, we'll
+include a driver so that you can use the lexer and parser together.
+
+`Next: Implementing a Parser and AST <OCamlLangImpl2.html>`_
+
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--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl2.rst.txt (added)
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+===========================================
+Kaleidoscope: Implementing a Parser and AST
+===========================================
+
+.. contents::
+ :local:
+
+Chapter 2 Introduction
+======================
+
+Welcome to Chapter 2 of the "`Implementing a language with LLVM in
+Objective Caml <index.html>`_" tutorial. This chapter shows you how to
+use the lexer, built in `Chapter 1 <OCamlLangImpl1.html>`_, to build a
+full `parser <http://en.wikipedia.org/wiki/Parsing>`_ for our
+Kaleidoscope language. Once we have a parser, we'll define and build an
+`Abstract Syntax
+Tree <http://en.wikipedia.org/wiki/Abstract_syntax_tree>`_ (AST).
+
+The parser we will build uses a combination of `Recursive Descent
+Parsing <http://en.wikipedia.org/wiki/Recursive_descent_parser>`_ and
+`Operator-Precedence
+Parsing <http://en.wikipedia.org/wiki/Operator-precedence_parser>`_ to
+parse the Kaleidoscope language (the latter for binary expressions and
+the former for everything else). Before we get to parsing though, lets
+talk about the output of the parser: the Abstract Syntax Tree.
+
+The Abstract Syntax Tree (AST)
+==============================
+
+The AST for a program captures its behavior in such a way that it is
+easy for later stages of the compiler (e.g. code generation) to
+interpret. We basically want one object for each construct in the
+language, and the AST should closely model the language. In
+Kaleidoscope, we have expressions, a prototype, and a function object.
+We'll start with expressions first:
+
+.. code-block:: ocaml
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+The code above shows the definition of the base ExprAST class and one
+subclass which we use for numeric literals. The important thing to note
+about this code is that the Number variant captures the numeric value of
+the literal as an instance variable. This allows later phases of the
+compiler to know what the stored numeric value is.
+
+Right now we only create the AST, so there are no useful functions on
+them. It would be very easy to add a function to pretty print the code,
+for example. Here are the other expression AST node definitions that
+we'll use in the basic form of the Kaleidoscope language:
+
+.. code-block:: ocaml
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+This is all (intentionally) rather straight-forward: variables capture
+the variable name, binary operators capture their opcode (e.g. '+'), and
+calls capture a function name as well as a list of any argument
+expressions. One thing that is nice about our AST is that it captures
+the language features without talking about the syntax of the language.
+Note that there is no discussion about precedence of binary operators,
+lexical structure, etc.
+
+For our basic language, these are all of the expression nodes we'll
+define. Because it doesn't have conditional control flow, it isn't
+Turing-complete; we'll fix that in a later installment. The two things
+we need next are a way to talk about the interface to a function, and a
+way to talk about functions themselves:
+
+.. code-block:: ocaml
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto = Prototype of string * string array
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+In Kaleidoscope, functions are typed with just a count of their
+arguments. Since all values are double precision floating point, the
+type of each argument doesn't need to be stored anywhere. In a more
+aggressive and realistic language, the "expr" variants would probably
+have a type field.
+
+With this scaffolding, we can now talk about parsing expressions and
+function bodies in Kaleidoscope.
+
+Parser Basics
+=============
+
+Now that we have an AST to build, we need to define the parser code to
+build it. The idea here is that we want to parse something like "x+y"
+(which is returned as three tokens by the lexer) into an AST that could
+be generated with calls like this:
+
+.. code-block:: ocaml
+
+ let x = Variable "x" in
+ let y = Variable "y" in
+ let result = Binary ('+', x, y) in
+ ...
+
+The error handling routines make use of the builtin ``Stream.Failure``
+and ``Stream.Error``s. ``Stream.Failure`` is raised when the parser is
+unable to find any matching token in the first position of a pattern.
+``Stream.Error`` is raised when the first token matches, but the rest do
+not. The error recovery in our parser will not be the best and is not
+particular user-friendly, but it will be enough for our tutorial. These
+exceptions make it easier to handle errors in routines that have various
+return types.
+
+With these basic types and exceptions, we can implement the first piece
+of our grammar: numeric literals.
+
+Basic Expression Parsing
+========================
+
+We start with numeric literals, because they are the simplest to
+process. For each production in our grammar, we'll define a function
+which parses that production. We call this class of expressions
+"primary" expressions, for reasons that will become more clear `later in
+the tutorial <OCamlLangImpl6.html#user-defined-unary-operators>`_. In order to parse an
+arbitrary primary expression, we need to determine what sort of
+expression it is. For numeric literals, we have:
+
+.. code-block:: ocaml
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr *)
+ parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+This routine is very simple: it expects to be called when the current
+token is a ``Token.Number`` token. It takes the current number value,
+creates a ``Ast.Number`` node, advances the lexer to the next token, and
+finally returns.
+
+There are some interesting aspects to this. The most important one is
+that this routine eats all of the tokens that correspond to the
+production and returns the lexer buffer with the next token (which is
+not part of the grammar production) ready to go. This is a fairly
+standard way to go for recursive descent parsers. For a better example,
+the parenthesis operator is defined like this:
+
+.. code-block:: ocaml
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+This function illustrates a number of interesting things about the
+parser:
+
+1) It shows how we use the ``Stream.Error`` exception. When called, this
+function expects that the current token is a '(' token, but after
+parsing the subexpression, it is possible that there is no ')' waiting.
+For example, if the user types in "(4 x" instead of "(4)", the parser
+should emit an error. Because errors can occur, the parser needs a way
+to indicate that they happened. In our parser, we use the camlp4
+shortcut syntax ``token ?? "parse error"``, where if the token before
+the ``??`` does not match, then ``Stream.Error "parse error"`` will be
+raised.
+
+2) Another interesting aspect of this function is that it uses recursion
+by calling ``Parser.parse_primary`` (we will soon see that
+``Parser.parse_primary`` can call ``Parser.parse_primary``). This is
+powerful because it allows us to handle recursive grammars, and keeps
+each production very simple. Note that parentheses do not cause
+construction of AST nodes themselves. While we could do it this way, the
+most important role of parentheses are to guide the parser and provide
+grouping. Once the parser constructs the AST, parentheses are not
+needed.
+
+The next simple production is for handling variable references and
+function calls:
+
+.. code-block:: ocaml
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+This routine follows the same style as the other routines. (It expects
+to be called if the current token is a ``Token.Ident`` token). It also
+has recursion and error handling. One interesting aspect of this is that
+it uses *look-ahead* to determine if the current identifier is a stand
+alone variable reference or if it is a function call expression. It
+handles this by checking to see if the token after the identifier is a
+'(' token, constructing either a ``Ast.Variable`` or ``Ast.Call`` node
+as appropriate.
+
+We finish up by raising an exception if we received a token we didn't
+expect:
+
+.. code-block:: ocaml
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+Now that basic expressions are handled, we need to handle binary
+expressions. They are a bit more complex.
+
+Binary Expression Parsing
+=========================
+
+Binary expressions are significantly harder to parse because they are
+often ambiguous. For example, when given the string "x+y\*z", the parser
+can choose to parse it as either "(x+y)\*z" or "x+(y\*z)". With common
+definitions from mathematics, we expect the later parse, because "\*"
+(multiplication) has higher *precedence* than "+" (addition).
+
+There are many ways to handle this, but an elegant and efficient way is
+to use `Operator-Precedence
+Parsing <http://en.wikipedia.org/wiki/Operator-precedence_parser>`_.
+This parsing technique uses the precedence of binary operators to guide
+recursion. To start with, we need a table of precedences:
+
+.. code-block:: ocaml
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ ...
+
+ let main () =
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+ ...
+
+For the basic form of Kaleidoscope, we will only support 4 binary
+operators (this can obviously be extended by you, our brave and intrepid
+reader). The ``Parser.precedence`` function returns the precedence for
+the current token, or -1 if the token is not a binary operator. Having a
+``Hashtbl.t`` makes it easy to add new operators and makes it clear that
+the algorithm doesn't depend on the specific operators involved, but it
+would be easy enough to eliminate the ``Hashtbl.t`` and do the
+comparisons in the ``Parser.precedence`` function. (Or just use a
+fixed-size array).
+
+With the helper above defined, we can now start parsing binary
+expressions. The basic idea of operator precedence parsing is to break
+down an expression with potentially ambiguous binary operators into
+pieces. Consider, for example, the expression "a+b+(c+d)\*e\*f+g".
+Operator precedence parsing considers this as a stream of primary
+expressions separated by binary operators. As such, it will first parse
+the leading primary expression "a", then it will see the pairs [+, b]
+[+, (c+d)] [\*, e] [\*, f] and [+, g]. Note that because parentheses are
+primary expressions, the binary expression parser doesn't need to worry
+about nested subexpressions like (c+d) at all.
+
+To start, an expression is a primary expression potentially followed by
+a sequence of [binop,primaryexpr] pairs:
+
+.. code-block:: ocaml
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_primary; stream >] -> parse_bin_rhs 0 lhs stream
+
+``Parser.parse_bin_rhs`` is the function that parses the sequence of
+pairs for us. It takes a precedence and a pointer to an expression for
+the part that has been parsed so far. Note that "x" is a perfectly valid
+expression: As such, "binoprhs" is allowed to be empty, in which case it
+returns the expression that is passed into it. In our example above, the
+code passes the expression for "a" into ``Parser.parse_bin_rhs`` and the
+current token is "+".
+
+The precedence value passed into ``Parser.parse_bin_rhs`` indicates the
+*minimal operator precedence* that the function is allowed to eat. For
+example, if the current pair stream is [+, x] and
+``Parser.parse_bin_rhs`` is passed in a precedence of 40, it will not
+consume any tokens (because the precedence of '+' is only 20). With this
+in mind, ``Parser.parse_bin_rhs`` starts with:
+
+.. code-block:: ocaml
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+
+This code gets the precedence of the current token and checks to see if
+if is too low. Because we defined invalid tokens to have a precedence of
+-1, this check implicitly knows that the pair-stream ends when the token
+stream runs out of binary operators. If this check succeeds, we know
+that the token is a binary operator and that it will be included in this
+expression:
+
+.. code-block:: ocaml
+
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator *)
+ let rhs = parse_primary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+
+As such, this code eats (and remembers) the binary operator and then
+parses the primary expression that follows. This builds up the whole
+pair, the first of which is [+, b] for the running example.
+
+Now that we parsed the left-hand side of an expression and one pair of
+the RHS sequence, we have to decide which way the expression associates.
+In particular, we could have "(a+b) binop unparsed" or "a + (b binop
+unparsed)". To determine this, we look ahead at "binop" to determine its
+precedence and compare it to BinOp's precedence (which is '+' in this
+case):
+
+.. code-block:: ocaml
+
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+
+If the precedence of the binop to the right of "RHS" is lower or equal
+to the precedence of our current operator, then we know that the
+parentheses associate as "(a+b) binop ...". In our example, the current
+operator is "+" and the next operator is "+", we know that they have the
+same precedence. In this case we'll create the AST node for "a+b", and
+then continue parsing:
+
+.. code-block:: ocaml
+
+ ... if body omitted ...
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+
+In our example above, this will turn "a+b+" into "(a+b)" and execute the
+next iteration of the loop, with "+" as the current token. The code
+above will eat, remember, and parse "(c+d)" as the primary expression,
+which makes the current pair equal to [+, (c+d)]. It will then evaluate
+the 'if' conditional above with "\*" as the binop to the right of the
+primary. In this case, the precedence of "\*" is higher than the
+precedence of "+" so the if condition will be entered.
+
+The critical question left here is "how can the if condition parse the
+right hand side in full"? In particular, to build the AST correctly for
+our example, it needs to get all of "(c+d)\*e\*f" as the RHS expression
+variable. The code to do this is surprisingly simple (code from the
+above two blocks duplicated for context):
+
+.. code-block:: ocaml
+
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ if token_prec < precedence c2
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+
+At this point, we know that the binary operator to the RHS of our
+primary has higher precedence than the binop we are currently parsing.
+As such, we know that any sequence of pairs whose operators are all
+higher precedence than "+" should be parsed together and returned as
+"RHS". To do this, we recursively invoke the ``Parser.parse_bin_rhs``
+function specifying "token\_prec+1" as the minimum precedence required
+for it to continue. In our example above, this will cause it to return
+the AST node for "(c+d)\*e\*f" as RHS, which is then set as the RHS of
+the '+' expression.
+
+Finally, on the next iteration of the while loop, the "+g" piece is
+parsed and added to the AST. With this little bit of code (14
+non-trivial lines), we correctly handle fully general binary expression
+parsing in a very elegant way. This was a whirlwind tour of this code,
+and it is somewhat subtle. I recommend running through it with a few
+tough examples to see how it works.
+
+This wraps up handling of expressions. At this point, we can point the
+parser at an arbitrary token stream and build an expression from it,
+stopping at the first token that is not part of the expression. Next up
+we need to handle function definitions, etc.
+
+Parsing the Rest
+================
+
+The next thing missing is handling of function prototypes. In
+Kaleidoscope, these are used both for 'extern' function declarations as
+well as function body definitions. The code to do this is
+straight-forward and not very interesting (once you've survived
+expressions):
+
+.. code-block:: ocaml
+
+ (* prototype
+ * ::= id '(' id* ')' *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+Given this, a function definition is very simple, just a prototype plus
+an expression to implement the body:
+
+.. code-block:: ocaml
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+In addition, we support 'extern' to declare functions like 'sin' and
+'cos' as well as to support forward declaration of user functions. These
+'extern's are just prototypes with no body:
+
+.. code-block:: ocaml
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+Finally, we'll also let the user type in arbitrary top-level expressions
+and evaluate them on the fly. We will handle this by defining anonymous
+nullary (zero argument) functions for them:
+
+.. code-block:: ocaml
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+Now that we have all the pieces, let's build a little driver that will
+let us actually *execute* this code we've built!
+
+The Driver
+==========
+
+The driver for this simply invokes all of the parsing pieces with a
+top-level dispatch loop. There isn't much interesting here, so I'll just
+include the top-level loop. See `below <#full-code-listing>`_ for full code in the
+"Top-Level Parsing" section.
+
+.. code-block:: ocaml
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ ignore(Parser.parse_definition stream);
+ print_endline "parsed a function definition.";
+ | Token.Extern ->
+ ignore(Parser.parse_extern stream);
+ print_endline "parsed an extern.";
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ ignore(Parser.parse_toplevel stream);
+ print_endline "parsed a top-level expr";
+ with Stream.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop stream
+
+The most interesting part of this is that we ignore top-level
+semicolons. Why is this, you ask? The basic reason is that if you type
+"4 + 5" at the command line, the parser doesn't know whether that is the
+end of what you will type or not. For example, on the next line you
+could type "def foo..." in which case 4+5 is the end of a top-level
+expression. Alternatively you could type "\* 6", which would continue
+the expression. Having top-level semicolons allows you to type "4+5;",
+and the parser will know you are done.
+
+Conclusions
+===========
+
+With just under 300 lines of commented code (240 lines of non-comment,
+non-blank code), we fully defined our minimal language, including a
+lexer, parser, and AST builder. With this done, the executable will
+validate Kaleidoscope code and tell us if it is grammatically invalid.
+For example, here is a sample interaction:
+
+.. code-block:: bash
+
+ $ ./toy.byte
+ ready> def foo(x y) x+foo(y, 4.0);
+ Parsed a function definition.
+ ready> def foo(x y) x+y y;
+ Parsed a function definition.
+ Parsed a top-level expr
+ ready> def foo(x y) x+y );
+ Parsed a function definition.
+ Error: unknown token when expecting an expression
+ ready> extern sin(a);
+ ready> Parsed an extern
+ ready> ^D
+ $
+
+There is a lot of room for extension here. You can define new AST nodes,
+extend the language in many ways, etc. In the `next
+installment <OCamlLangImpl3.html>`_, we will describe how to generate
+LLVM Intermediate Representation (IR) from the AST.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for this and the previous chapter.
+Note that it is fully self-contained: you don't need LLVM or any
+external libraries at all for this. (Besides the ocaml standard
+libraries, of course.) To build this, just compile with:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto = Prototype of string * string array
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator. *)
+ let rhs = parse_primary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_primary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')' *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ ignore(Parser.parse_definition stream);
+ print_endline "parsed a function definition.";
+ | Token.Extern ->
+ ignore(Parser.parse_extern stream);
+ print_endline "parsed an extern.";
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ ignore(Parser.parse_toplevel stream);
+ print_endline "parsed a top-level expr";
+ with Stream.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ let main () =
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop stream;
+ ;;
+
+ main ()
+
+`Next: Implementing Code Generation to LLVM IR <OCamlLangImpl3.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl3.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl3.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl3.rst.txt (added)
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@@ -0,0 +1,961 @@
+========================================
+Kaleidoscope: Code generation to LLVM IR
+========================================
+
+.. contents::
+ :local:
+
+Chapter 3 Introduction
+======================
+
+Welcome to Chapter 3 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. This chapter shows you how to transform
+the `Abstract Syntax Tree <OCamlLangImpl2.html>`_, built in Chapter 2,
+into LLVM IR. This will teach you a little bit about how LLVM does
+things, as well as demonstrate how easy it is to use. It's much more
+work to build a lexer and parser than it is to generate LLVM IR code. :)
+
+**Please note**: the code in this chapter and later require LLVM 2.3 or
+LLVM SVN to work. LLVM 2.2 and before will not work with it.
+
+Code Generation Setup
+=====================
+
+In order to generate LLVM IR, we want some simple setup to get started.
+First we define virtual code generation (codegen) methods in each AST
+class:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ | Ast.Number n -> ...
+ | Ast.Variable name -> ...
+
+The ``Codegen.codegen_expr`` function says to emit IR for that AST node
+along with all the things it depends on, and they all return an LLVM
+Value object. "Value" is the class used to represent a "`Static Single
+Assignment
+(SSA) <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+register" or "SSA value" in LLVM. The most distinct aspect of SSA values
+is that their value is computed as the related instruction executes, and
+it does not get a new value until (and if) the instruction re-executes.
+In other words, there is no way to "change" an SSA value. For more
+information, please read up on `Static Single
+Assignment <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+- the concepts are really quite natural once you grok them.
+
+The second thing we want is an "Error" exception like we used for the
+parser, which will be used to report errors found during code generation
+(for example, use of an undeclared parameter):
+
+.. code-block:: ocaml
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+The static variables will be used during code generation.
+``Codgen.the_module`` is the LLVM construct that contains all of the
+functions and global variables in a chunk of code. In many ways, it is
+the top-level structure that the LLVM IR uses to contain code.
+
+The ``Codegen.builder`` object is a helper object that makes it easy to
+generate LLVM instructions. Instances of the
+`IRBuilder <http://llvm.org/doxygen/IRBuilder_8h-source.html>`_
+class keep track of the current place to insert instructions and has
+methods to create new instructions.
+
+The ``Codegen.named_values`` map keeps track of which values are defined
+in the current scope and what their LLVM representation is. (In other
+words, it is a symbol table for the code). In this form of Kaleidoscope,
+the only things that can be referenced are function parameters. As such,
+function parameters will be in this map when generating code for their
+function body.
+
+With these basics in place, we can start talking about how to generate
+code for each expression. Note that this assumes that the
+``Codgen.builder`` has been set up to generate code *into* something.
+For now, we'll assume that this has already been done, and we'll just
+use it to emit code.
+
+Expression Code Generation
+==========================
+
+Generating LLVM code for expression nodes is very straightforward: less
+than 30 lines of commented code for all four of our expression nodes.
+First we'll do numeric literals:
+
+.. code-block:: ocaml
+
+ | Ast.Number n -> const_float double_type n
+
+In the LLVM IR, numeric constants are represented with the
+``ConstantFP`` class, which holds the numeric value in an ``APFloat``
+internally (``APFloat`` has the capability of holding floating point
+constants of Arbitrary Precision). This code basically just creates
+and returns a ``ConstantFP``. Note that in the LLVM IR that constants
+are all uniqued together and shared. For this reason, the API uses "the
+foo::get(..)" idiom instead of "new foo(..)" or "foo::Create(..)".
+
+.. code-block:: ocaml
+
+ | Ast.Variable name ->
+ (try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name"))
+
+References to variables are also quite simple using LLVM. In the simple
+version of Kaleidoscope, we assume that the variable has already been
+emitted somewhere and its value is available. In practice, the only
+values that can be in the ``Codegen.named_values`` map are function
+arguments. This code simply checks to see that the specified name is in
+the map (if not, an unknown variable is being referenced) and returns
+the value for it. In future chapters, we'll add support for `loop
+induction variables <LangImpl5.html#for-loop-expression>`_ in the symbol table, and for
+`local variables <LangImpl7.html#user-defined-local-variables>`_.
+
+.. code-block:: ocaml
+
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_fadd lhs_val rhs_val "addtmp" builder
+ | '-' -> build_fsub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_fmul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ -> raise (Error "invalid binary operator")
+ end
+
+Binary operators start to get more interesting. The basic idea here is
+that we recursively emit code for the left-hand side of the expression,
+then the right-hand side, then we compute the result of the binary
+expression. In this code, we do a simple switch on the opcode to create
+the right LLVM instruction.
+
+In the example above, the LLVM builder class is starting to show its
+value. IRBuilder knows where to insert the newly created instruction,
+all you have to do is specify what instruction to create (e.g. with
+``Llvm.create_add``), which operands to use (``lhs`` and ``rhs`` here)
+and optionally provide a name for the generated instruction.
+
+One nice thing about LLVM is that the name is just a hint. For instance,
+if the code above emits multiple "addtmp" variables, LLVM will
+automatically provide each one with an increasing, unique numeric
+suffix. Local value names for instructions are purely optional, but it
+makes it much easier to read the IR dumps.
+
+`LLVM instructions <../LangRef.html#instruction-reference>`_ are constrained by strict
+rules: for example, the Left and Right operators of an `add
+instruction <../LangRef.html#add-instruction>`_ must have the same type, and the
+result type of the add must match the operand types. Because all values
+in Kaleidoscope are doubles, this makes for very simple code for add,
+sub and mul.
+
+On the other hand, LLVM specifies that the `fcmp
+instruction <../LangRef.html#fcmp-instruction>`_ always returns an 'i1' value (a
+one bit integer). The problem with this is that Kaleidoscope wants the
+value to be a 0.0 or 1.0 value. In order to get these semantics, we
+combine the fcmp instruction with a `uitofp
+instruction <../LangRef.html#uitofp-to-instruction>`_. This instruction converts its
+input integer into a floating point value by treating the input as an
+unsigned value. In contrast, if we used the `sitofp
+instruction <../LangRef.html#sitofp-to-instruction>`_, the Kaleidoscope '<' operator
+would return 0.0 and -1.0, depending on the input value.
+
+.. code-block:: ocaml
+
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+
+Code generation for function calls is quite straightforward with LLVM.
+The code above initially does a function name lookup in the LLVM
+Module's symbol table. Recall that the LLVM Module is the container that
+holds all of the functions we are JIT'ing. By giving each function the
+same name as what the user specifies, we can use the LLVM symbol table
+to resolve function names for us.
+
+Once we have the function to call, we recursively codegen each argument
+that is to be passed in, and create an LLVM `call
+instruction <../LangRef.html#call-instruction>`_. Note that LLVM uses the native C
+calling conventions by default, allowing these calls to also call into
+standard library functions like "sin" and "cos", with no additional
+effort.
+
+This wraps up our handling of the four basic expressions that we have so
+far in Kaleidoscope. Feel free to go in and add some more. For example,
+by browsing the `LLVM language reference <../LangRef.html>`_ you'll find
+several other interesting instructions that are really easy to plug into
+our basic framework.
+
+Function Code Generation
+========================
+
+Code generation for prototypes and functions must handle a number of
+details, which make their code less beautiful than expression code
+generation, but allows us to illustrate some important points. First,
+lets talk about code generation for prototypes: they are used both for
+function bodies and external function declarations. The code starts
+with:
+
+.. code-block:: ocaml
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+
+This code packs a lot of power into a few lines. Note first that this
+function returns a "Function\*" instead of a "Value\*" (although at the
+moment they both are modeled by ``llvalue`` in ocaml). Because a
+"prototype" really talks about the external interface for a function
+(not the value computed by an expression), it makes sense for it to
+return the LLVM Function it corresponds to when codegen'd.
+
+The call to ``Llvm.function_type`` creates the ``Llvm.llvalue`` that
+should be used for a given Prototype. Since all function arguments in
+Kaleidoscope are of type double, the first line creates a vector of "N"
+LLVM double types. It then uses the ``Llvm.function_type`` method to
+create a function type that takes "N" doubles as arguments, returns one
+double as a result, and that is not vararg (that uses the function
+``Llvm.var_arg_function_type``). Note that Types in LLVM are uniqued
+just like ``Constant``'s are, so you don't "new" a type, you "get" it.
+
+The final line above checks if the function has already been defined in
+``Codegen.the_module``. If not, we will create it.
+
+.. code-block:: ocaml
+
+ | None -> declare_function name ft the_module
+
+This indicates the type and name to use, as well as which module to
+insert into. By default we assume a function has
+``Llvm.Linkage.ExternalLinkage``. "`external
+linkage <../LangRef.html#linkage>`_" means that the function may be defined
+outside the current module and/or that it is callable by functions
+outside the module. The "``name``" passed in is the name the user
+specified: this name is registered in "``Codegen.the_module``"s symbol
+table, which is used by the function call code above.
+
+In Kaleidoscope, I choose to allow redefinitions of functions in two
+cases: first, we want to allow 'extern'ing a function more than once, as
+long as the prototypes for the externs match (since all arguments have
+the same type, we just have to check that the number of arguments
+match). Second, we want to allow 'extern'ing a function and then
+defining a body for it. This is useful when defining mutually recursive
+functions.
+
+.. code-block:: ocaml
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if Array.length (basic_blocks f) == 0 then () else
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if Array.length (params f) == Array.length args then () else
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+In order to verify the logic above, we first check to see if the
+pre-existing function is "empty". In this case, empty means that it has
+no basic blocks in it, which means it has no body. If it has no body, it
+is a forward declaration. Since we don't allow anything after a full
+definition of the function, the code rejects this case. If the previous
+reference to a function was an 'extern', we simply verify that the
+number of arguments for that definition and this one match up. If not,
+we emit an error.
+
+.. code-block:: ocaml
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+The last bit of code for prototypes loops over all of the arguments in
+the function, setting the name of the LLVM Argument objects to match,
+and registering the arguments in the ``Codegen.named_values`` map for
+future use by the ``Ast.Variable`` variant. Once this is set up, it
+returns the Function object to the caller. Note that we don't check for
+conflicting argument names here (e.g. "extern foo(a b a)"). Doing so
+would be very straight-forward with the mechanics we have already used
+above.
+
+.. code-block:: ocaml
+
+ let codegen_func = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+Code generation for function definitions starts out simply enough: we
+just codegen the prototype (Proto) and verify that it is ok. We then
+clear out the ``Codegen.named_values`` map to make sure that there isn't
+anything in it from the last function we compiled. Code generation of
+the prototype ensures that there is an LLVM Function object that is
+ready to go for us.
+
+.. code-block:: ocaml
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ let ret_val = codegen_expr body in
+
+Now we get to the point where the ``Codegen.builder`` is set up. The
+first line creates a new `basic
+block <http://en.wikipedia.org/wiki/Basic_block>`_ (named "entry"),
+which is inserted into ``the_function``. The second line then tells the
+builder that new instructions should be inserted into the end of the new
+basic block. Basic blocks in LLVM are an important part of functions
+that define the `Control Flow
+Graph <http://en.wikipedia.org/wiki/Control_flow_graph>`_. Since we
+don't have any control flow, our functions will only contain one block
+at this point. We'll fix this in `Chapter 5 <OCamlLangImpl5.html>`_ :).
+
+.. code-block:: ocaml
+
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ the_function
+
+Once the insertion point is set up, we call the ``Codegen.codegen_func``
+method for the root expression of the function. If no error happens,
+this emits code to compute the expression into the entry block and
+returns the value that was computed. Assuming no error, we then create
+an LLVM `ret instruction <../LangRef.html#ret-instruction>`_, which completes the
+function. Once the function is built, we call
+``Llvm_analysis.assert_valid_function``, which is provided by LLVM. This
+function does a variety of consistency checks on the generated code, to
+determine if our compiler is doing everything right. Using this is
+important: it can catch a lot of bugs. Once the function is finished and
+validated, we return it.
+
+.. code-block:: ocaml
+
+ with e ->
+ delete_function the_function;
+ raise e
+
+The only piece left here is handling of the error case. For simplicity,
+we handle this by merely deleting the function we produced with the
+``Llvm.delete_function`` method. This allows the user to redefine a
+function that they incorrectly typed in before: if we didn't delete it,
+it would live in the symbol table, with a body, preventing future
+redefinition.
+
+This code does have a bug, though. Since the ``Codegen.codegen_proto``
+can return a previously defined forward declaration, our code can
+actually delete a forward declaration. There are a number of ways to fix
+this bug, see what you can come up with! Here is a testcase:
+
+::
+
+ extern foo(a b); # ok, defines foo.
+ def foo(a b) c; # error, 'c' is invalid.
+ def bar() foo(1, 2); # error, unknown function "foo"
+
+Driver Changes and Closing Thoughts
+===================================
+
+For now, code generation to LLVM doesn't really get us much, except that
+we can look at the pretty IR calls. The sample code inserts calls to
+Codegen into the "``Toplevel.main_loop``", and then dumps out the LLVM
+IR. This gives a nice way to look at the LLVM IR for simple functions.
+For example:
+
+::
+
+ ready> 4+5;
+ Read top-level expression:
+ define double @""() {
+ entry:
+ %addtmp = fadd double 4.000000e+00, 5.000000e+00
+ ret double %addtmp
+ }
+
+Note how the parser turns the top-level expression into anonymous
+functions for us. This will be handy when we add `JIT
+support <OCamlLangImpl4.html#adding-a-jit-compiler>`_ in the next chapter. Also note that
+the code is very literally transcribed, no optimizations are being
+performed. We will `add
+optimizations <OCamlLangImpl4.html#trivial-constant-folding>`_ explicitly in the
+next chapter.
+
+::
+
+ ready> def foo(a b) a*a + 2*a*b + b*b;
+ Read function definition:
+ define double @foo(double %a, double %b) {
+ entry:
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
+ }
+
+This shows some simple arithmetic. Notice the striking similarity to the
+LLVM builder calls that we use to create the instructions.
+
+::
+
+ ready> def bar(a) foo(a, 4.0) + bar(31337);
+ Read function definition:
+ define double @bar(double %a) {
+ entry:
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
+ }
+
+This shows some function calls. Note that this function will take a long
+time to execute if you call it. In the future we'll add conditional
+control flow to actually make recursion useful :).
+
+::
+
+ ready> extern cos(x);
+ Read extern:
+ declare double @cos(double)
+
+ ready> cos(1.234);
+ Read top-level expression:
+ define double @""() {
+ entry:
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
+ }
+
+This shows an extern for the libm "cos" function, and a call to it.
+
+::
+
+ ready> ^D
+ ; ModuleID = 'my cool jit'
+
+ define double @""() {
+ entry:
+ %addtmp = fadd double 4.000000e+00, 5.000000e+00
+ ret double %addtmp
+ }
+
+ define double @foo(double %a, double %b) {
+ entry:
+ %multmp = fmul double %a, %a
+ %multmp1 = fmul double 2.000000e+00, %a
+ %multmp2 = fmul double %multmp1, %b
+ %addtmp = fadd double %multmp, %multmp2
+ %multmp3 = fmul double %b, %b
+ %addtmp4 = fadd double %addtmp, %multmp3
+ ret double %addtmp4
+ }
+
+ define double @bar(double %a) {
+ entry:
+ %calltmp = call double @foo(double %a, double 4.000000e+00)
+ %calltmp1 = call double @bar(double 3.133700e+04)
+ %addtmp = fadd double %calltmp, %calltmp1
+ ret double %addtmp
+ }
+
+ declare double @cos(double)
+
+ define double @""() {
+ entry:
+ %calltmp = call double @cos(double 1.234000e+00)
+ ret double %calltmp
+ }
+
+When you quit the current demo, it dumps out the IR for the entire
+module generated. Here you can see the big picture with all the
+functions referencing each other.
+
+This wraps up the third chapter of the Kaleidoscope tutorial. Up next,
+we'll describe how to `add JIT codegen and optimizer
+support <OCamlLangImpl4.html>`_ to this so we can actually start running
+code!
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the LLVM code generator. Because this uses the LLVM libraries, we need
+to link them in. To do this, we use the
+`llvm-config <http://llvm.org/cmds/llvm-config.html>`_ tool to inform
+our makefile/command line about which options to use:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+ <*.{byte,native}>: g++, use_llvm, use_llvm_analysis
+
+myocamlbuild.ml:
+ .. code-block:: ocaml
+
+ open Ocamlbuild_plugin;;
+
+ ocaml_lib ~extern:true "llvm";;
+ ocaml_lib ~extern:true "llvm_analysis";;
+
+ flag ["link"; "ocaml"; "g++"] (S[A"-cc"; A"g++"]);;
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto = Prototype of string * string array
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator. *)
+ let rhs = parse_primary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_primary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')' *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+codegen.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Code Generation
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+ let rec codegen_expr = function
+ | Ast.Number n -> const_float double_type n
+ | Ast.Variable name ->
+ (try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name"))
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ -> raise (Error "invalid binary operator")
+ end
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+ | None -> declare_function name ft the_module
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if block_begin f <> At_end f then
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if element_type (type_of f) <> ft then
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+ let codegen_func = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ the_function
+ with e ->
+ delete_function the_function;
+ raise e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ let e = Parser.parse_definition stream in
+ print_endline "parsed a function definition.";
+ dump_value (Codegen.codegen_func e);
+ | Token.Extern ->
+ let e = Parser.parse_extern stream in
+ print_endline "parsed an extern.";
+ dump_value (Codegen.codegen_proto e);
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ dump_value (Codegen.codegen_func e);
+ with Stream.Error s | Codegen.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ let main () =
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop stream;
+
+ (* Print out all the generated code. *)
+ dump_module Codegen.the_module
+ ;;
+
+ main ()
+
+`Next: Adding JIT and Optimizer Support <OCamlLangImpl4.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl4.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl4.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl4.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl4.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,915 @@
+==============================================
+Kaleidoscope: Adding JIT and Optimizer Support
+==============================================
+
+.. contents::
+ :local:
+
+Chapter 4 Introduction
+======================
+
+Welcome to Chapter 4 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. Chapters 1-3 described the implementation
+of a simple language and added support for generating LLVM IR. This
+chapter describes two new techniques: adding optimizer support to your
+language, and adding JIT compiler support. These additions will
+demonstrate how to get nice, efficient code for the Kaleidoscope
+language.
+
+Trivial Constant Folding
+========================
+
+**Note:** the default ``IRBuilder`` now always includes the constant
+folding optimisations below.
+
+Our demonstration for Chapter 3 is elegant and easy to extend.
+Unfortunately, it does not produce wonderful code. For example, when
+compiling simple code, we don't get obvious optimizations:
+
+::
+
+ ready> def test(x) 1+2+x;
+ Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 1.000000e+00, 2.000000e+00
+ %addtmp1 = fadd double %addtmp, %x
+ ret double %addtmp1
+ }
+
+This code is a very, very literal transcription of the AST built by
+parsing the input. As such, this transcription lacks optimizations like
+constant folding (we'd like to get "``add x, 3.0``" in the example
+above) as well as other more important optimizations. Constant folding,
+in particular, is a very common and very important optimization: so much
+so that many language implementors implement constant folding support in
+their AST representation.
+
+With LLVM, you don't need this support in the AST. Since all calls to
+build LLVM IR go through the LLVM builder, it would be nice if the
+builder itself checked to see if there was a constant folding
+opportunity when you call it. If so, it could just do the constant fold
+and return the constant instead of creating an instruction. This is
+exactly what the ``LLVMFoldingBuilder`` class does.
+
+All we did was switch from ``LLVMBuilder`` to ``LLVMFoldingBuilder``.
+Though we change no other code, we now have all of our instructions
+implicitly constant folded without us having to do anything about it.
+For example, the input above now compiles to:
+
+::
+
+ ready> def test(x) 1+2+x;
+ Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 3.000000e+00, %x
+ ret double %addtmp
+ }
+
+Well, that was easy :). In practice, we recommend always using
+``LLVMFoldingBuilder`` when generating code like this. It has no
+"syntactic overhead" for its use (you don't have to uglify your compiler
+with constant checks everywhere) and it can dramatically reduce the
+amount of LLVM IR that is generated in some cases (particular for
+languages with a macro preprocessor or that use a lot of constants).
+
+On the other hand, the ``LLVMFoldingBuilder`` is limited by the fact
+that it does all of its analysis inline with the code as it is built. If
+you take a slightly more complex example:
+
+::
+
+ ready> def test(x) (1+2+x)*(x+(1+2));
+ ready> Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double 3.000000e+00, %x
+ %addtmp1 = fadd double %x, 3.000000e+00
+ %multmp = fmul double %addtmp, %addtmp1
+ ret double %multmp
+ }
+
+In this case, the LHS and RHS of the multiplication are the same value.
+We'd really like to see this generate "``tmp = x+3; result = tmp*tmp;``"
+instead of computing "``x*3``" twice.
+
+Unfortunately, no amount of local analysis will be able to detect and
+correct this. This requires two transformations: reassociation of
+expressions (to make the add's lexically identical) and Common
+Subexpression Elimination (CSE) to delete the redundant add instruction.
+Fortunately, LLVM provides a broad range of optimizations that you can
+use, in the form of "passes".
+
+LLVM Optimization Passes
+========================
+
+LLVM provides many optimization passes, which do many different sorts of
+things and have different tradeoffs. Unlike other systems, LLVM doesn't
+hold to the mistaken notion that one set of optimizations is right for
+all languages and for all situations. LLVM allows a compiler implementor
+to make complete decisions about what optimizations to use, in which
+order, and in what situation.
+
+As a concrete example, LLVM supports both "whole module" passes, which
+look across as large of body of code as they can (often a whole file,
+but if run at link time, this can be a substantial portion of the whole
+program). It also supports and includes "per-function" passes which just
+operate on a single function at a time, without looking at other
+functions. For more information on passes and how they are run, see the
+`How to Write a Pass <../WritingAnLLVMPass.html>`_ document and the
+`List of LLVM Passes <../Passes.html>`_.
+
+For Kaleidoscope, we are currently generating functions on the fly, one
+at a time, as the user types them in. We aren't shooting for the
+ultimate optimization experience in this setting, but we also want to
+catch the easy and quick stuff where possible. As such, we will choose
+to run a few per-function optimizations as the user types the function
+in. If we wanted to make a "static Kaleidoscope compiler", we would use
+exactly the code we have now, except that we would defer running the
+optimizer until the entire file has been parsed.
+
+In order to get per-function optimizations going, we need to set up a
+`Llvm.PassManager <../WritingAnLLVMPass.html#what-passmanager-does>`_ to hold and
+organize the LLVM optimizations that we want to run. Once we have that,
+we can add a set of optimizations to run. The code looks like this:
+
+.. code-block:: ocaml
+
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combining the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+ (* Eliminate Common SubExpressions. *)
+ add_gvn the_fpm;
+
+ (* Simplify the control flow graph (deleting unreachable blocks, etc). *)
+ add_cfg_simplification the_fpm;
+
+ ignore (PassManager.initialize the_fpm);
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop the_fpm the_execution_engine stream;
+
+The meat of the matter here, is the definition of "``the_fpm``". It
+requires a pointer to the ``the_module`` to construct itself. Once it is
+set up, we use a series of "add" calls to add a bunch of LLVM passes.
+The first pass is basically boilerplate, it adds a pass so that later
+optimizations know how the data structures in the program are laid out.
+The "``the_execution_engine``" variable is related to the JIT, which we
+will get to in the next section.
+
+In this case, we choose to add 4 optimization passes. The passes we
+chose here are a pretty standard set of "cleanup" optimizations that are
+useful for a wide variety of code. I won't delve into what they do but,
+believe me, they are a good starting place :).
+
+Once the ``Llvm.PassManager.`` is set up, we need to make use of it. We
+do this by running it after our newly created function is constructed
+(in ``Codegen.codegen_func``), but before it is returned to the client:
+
+.. code-block:: ocaml
+
+ let codegen_func the_fpm = function
+ ...
+ try
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ (* Optimize the function. *)
+ let _ = PassManager.run_function the_function the_fpm in
+
+ the_function
+
+As you can see, this is pretty straightforward. The ``the_fpm``
+optimizes and updates the LLVM Function\* in place, improving
+(hopefully) its body. With this in place, we can try our test above
+again:
+
+::
+
+ ready> def test(x) (1+2+x)*(x+(1+2));
+ ready> Read function definition:
+ define double @test(double %x) {
+ entry:
+ %addtmp = fadd double %x, 3.000000e+00
+ %multmp = fmul double %addtmp, %addtmp
+ ret double %multmp
+ }
+
+As expected, we now get our nicely optimized code, saving a floating
+point add instruction from every execution of this function.
+
+LLVM provides a wide variety of optimizations that can be used in
+certain circumstances. Some `documentation about the various
+passes <../Passes.html>`_ is available, but it isn't very complete.
+Another good source of ideas can come from looking at the passes that
+``Clang`` runs to get started. The "``opt``" tool allows you to
+experiment with passes from the command line, so you can see if they do
+anything.
+
+Now that we have reasonable code coming out of our front-end, lets talk
+about executing it!
+
+Adding a JIT Compiler
+=====================
+
+Code that is available in LLVM IR can have a wide variety of tools
+applied to it. For example, you can run optimizations on it (as we did
+above), you can dump it out in textual or binary forms, you can compile
+the code to an assembly file (.s) for some target, or you can JIT
+compile it. The nice thing about the LLVM IR representation is that it
+is the "common currency" between many different parts of the compiler.
+
+In this section, we'll add JIT compiler support to our interpreter. The
+basic idea that we want for Kaleidoscope is to have the user enter
+function bodies as they do now, but immediately evaluate the top-level
+expressions they type in. For example, if they type in "1 + 2;", we
+should evaluate and print out 3. If they define a function, they should
+be able to call it from the command line.
+
+In order to do this, we first declare and initialize the JIT. This is
+done by adding a global variable and a call in ``main``:
+
+.. code-block:: ocaml
+
+ ...
+ let main () =
+ ...
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ ...
+
+This creates an abstract "Execution Engine" which can be either a JIT
+compiler or the LLVM interpreter. LLVM will automatically pick a JIT
+compiler for you if one is available for your platform, otherwise it
+will fall back to the interpreter.
+
+Once the ``Llvm_executionengine.ExecutionEngine.t`` is created, the JIT
+is ready to be used. There are a variety of APIs that are useful, but
+the simplest one is the
+"``Llvm_executionengine.ExecutionEngine.run_function``" function. This
+method JIT compiles the specified LLVM Function and returns a function
+pointer to the generated machine code. In our case, this means that we
+can change the code that parses a top-level expression to look like
+this:
+
+.. code-block:: ocaml
+
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ let the_function = Codegen.codegen_func the_fpm e in
+ dump_value the_function;
+
+ (* JIT the function, returning a function pointer. *)
+ let result = ExecutionEngine.run_function the_function [||]
+ the_execution_engine in
+
+ print_string "Evaluated to ";
+ print_float (GenericValue.as_float Codegen.double_type result);
+ print_newline ();
+
+Recall that we compile top-level expressions into a self-contained LLVM
+function that takes no arguments and returns the computed double.
+Because the LLVM JIT compiler matches the native platform ABI, this
+means that you can just cast the result pointer to a function pointer of
+that type and call it directly. This means, there is no difference
+between JIT compiled code and native machine code that is statically
+linked into your application.
+
+With just these two changes, lets see how Kaleidoscope works now!
+
+::
+
+ ready> 4+5;
+ define double @""() {
+ entry:
+ ret double 9.000000e+00
+ }
+
+ Evaluated to 9.000000
+
+Well this looks like it is basically working. The dump of the function
+shows the "no argument function that always returns double" that we
+synthesize for each top level expression that is typed in. This
+demonstrates very basic functionality, but can we do more?
+
+::
+
+ ready> def testfunc(x y) x + y*2;
+ Read function definition:
+ define double @testfunc(double %x, double %y) {
+ entry:
+ %multmp = fmul double %y, 2.000000e+00
+ %addtmp = fadd double %multmp, %x
+ ret double %addtmp
+ }
+
+ ready> testfunc(4, 10);
+ define double @""() {
+ entry:
+ %calltmp = call double @testfunc(double 4.000000e+00, double 1.000000e+01)
+ ret double %calltmp
+ }
+
+ Evaluated to 24.000000
+
+This illustrates that we can now call user code, but there is something
+a bit subtle going on here. Note that we only invoke the JIT on the
+anonymous functions that *call testfunc*, but we never invoked it on
+*testfunc* itself. What actually happened here is that the JIT scanned
+for all non-JIT'd functions transitively called from the anonymous
+function and compiled all of them before returning from
+``run_function``.
+
+The JIT provides a number of other more advanced interfaces for things
+like freeing allocated machine code, rejit'ing functions to update them,
+etc. However, even with this simple code, we get some surprisingly
+powerful capabilities - check this out (I removed the dump of the
+anonymous functions, you should get the idea by now :) :
+
+::
+
+ ready> extern sin(x);
+ Read extern:
+ declare double @sin(double)
+
+ ready> extern cos(x);
+ Read extern:
+ declare double @cos(double)
+
+ ready> sin(1.0);
+ Evaluated to 0.841471
+
+ ready> def foo(x) sin(x)*sin(x) + cos(x)*cos(x);
+ Read function definition:
+ define double @foo(double %x) {
+ entry:
+ %calltmp = call double @sin(double %x)
+ %multmp = fmul double %calltmp, %calltmp
+ %calltmp2 = call double @cos(double %x)
+ %multmp4 = fmul double %calltmp2, %calltmp2
+ %addtmp = fadd double %multmp, %multmp4
+ ret double %addtmp
+ }
+
+ ready> foo(4.0);
+ Evaluated to 1.000000
+
+Whoa, how does the JIT know about sin and cos? The answer is
+surprisingly simple: in this example, the JIT started execution of a
+function and got to a function call. It realized that the function was
+not yet JIT compiled and invoked the standard set of routines to resolve
+the function. In this case, there is no body defined for the function,
+so the JIT ended up calling "``dlsym("sin")``" on the Kaleidoscope
+process itself. Since "``sin``" is defined within the JIT's address
+space, it simply patches up calls in the module to call the libm version
+of ``sin`` directly.
+
+The LLVM JIT provides a number of interfaces (look in the
+``llvm_executionengine.mli`` file) for controlling how unknown functions
+get resolved. It allows you to establish explicit mappings between IR
+objects and addresses (useful for LLVM global variables that you want to
+map to static tables, for example), allows you to dynamically decide on
+the fly based on the function name, and even allows you to have the JIT
+compile functions lazily the first time they're called.
+
+One interesting application of this is that we can now extend the
+language by writing arbitrary C code to implement operations. For
+example, if we add:
+
+.. code-block:: c++
+
+ /* putchard - putchar that takes a double and returns 0. */
+ extern "C"
+ double putchard(double X) {
+ putchar((char)X);
+ return 0;
+ }
+
+Now we can produce simple output to the console by using things like:
+"``extern putchard(x); putchard(120);``", which prints a lowercase 'x'
+on the console (120 is the ASCII code for 'x'). Similar code could be
+used to implement file I/O, console input, and many other capabilities
+in Kaleidoscope.
+
+This completes the JIT and optimizer chapter of the Kaleidoscope
+tutorial. At this point, we can compile a non-Turing-complete
+programming language, optimize and JIT compile it in a user-driven way.
+Next up we'll look into `extending the language with control flow
+constructs <OCamlLangImpl5.html>`_, tackling some interesting LLVM IR
+issues along the way.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the LLVM JIT and optimizer. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+ <*.{byte,native}>: g++, use_llvm, use_llvm_analysis
+ <*.{byte,native}>: use_llvm_executionengine, use_llvm_target
+ <*.{byte,native}>: use_llvm_scalar_opts, use_bindings
+
+myocamlbuild.ml:
+ .. code-block:: ocaml
+
+ open Ocamlbuild_plugin;;
+
+ ocaml_lib ~extern:true "llvm";;
+ ocaml_lib ~extern:true "llvm_analysis";;
+ ocaml_lib ~extern:true "llvm_executionengine";;
+ ocaml_lib ~extern:true "llvm_target";;
+ ocaml_lib ~extern:true "llvm_scalar_opts";;
+
+ flag ["link"; "ocaml"; "g++"] (S[A"-cc"; A"g++"]);;
+ dep ["link"; "ocaml"; "use_bindings"] ["bindings.o"];;
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto = Prototype of string * string array
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator. *)
+ let rhs = parse_primary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_primary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')' *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+codegen.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Code Generation
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+ let rec codegen_expr = function
+ | Ast.Number n -> const_float double_type n
+ | Ast.Variable name ->
+ (try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name"))
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ -> raise (Error "invalid binary operator")
+ end
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+ | None -> declare_function name ft the_module
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if block_begin f <> At_end f then
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if element_type (type_of f) <> ft then
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+ let codegen_func the_fpm = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ (* Optimize the function. *)
+ let _ = PassManager.run_function the_function the_fpm in
+
+ the_function
+ with e ->
+ delete_function the_function;
+ raise e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop the_fpm the_execution_engine stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop the_fpm the_execution_engine stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ let e = Parser.parse_definition stream in
+ print_endline "parsed a function definition.";
+ dump_value (Codegen.codegen_func the_fpm e);
+ | Token.Extern ->
+ let e = Parser.parse_extern stream in
+ print_endline "parsed an extern.";
+ dump_value (Codegen.codegen_proto e);
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ let the_function = Codegen.codegen_func the_fpm e in
+ dump_value the_function;
+
+ (* JIT the function, returning a function pointer. *)
+ let result = ExecutionEngine.run_function the_function [||]
+ the_execution_engine in
+
+ print_string "Evaluated to ";
+ print_float (GenericValue.as_float Codegen.double_type result);
+ print_newline ();
+ with Stream.Error s | Codegen.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop the_fpm the_execution_engine stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+ open Llvm_target
+ open Llvm_scalar_opts
+
+ let main () =
+ ignore (initialize_native_target ());
+
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combination the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+ (* Eliminate Common SubExpressions. *)
+ add_gvn the_fpm;
+
+ (* Simplify the control flow graph (deleting unreachable blocks, etc). *)
+ add_cfg_simplification the_fpm;
+
+ ignore (PassManager.initialize the_fpm);
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop the_fpm the_execution_engine stream;
+
+ (* Print out all the generated code. *)
+ dump_module Codegen.the_module
+ ;;
+
+ main ()
+
+bindings.c
+ .. code-block:: c
+
+ #include <stdio.h>
+
+ /* putchard - putchar that takes a double and returns 0. */
+ extern double putchard(double X) {
+ putchar((char)X);
+ return 0;
+ }
+
+`Next: Extending the language: control flow <OCamlLangImpl5.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl5.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl5.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl5.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl5.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,1350 @@
+==================================================
+Kaleidoscope: Extending the Language: Control Flow
+==================================================
+
+.. contents::
+ :local:
+
+Chapter 5 Introduction
+======================
+
+Welcome to Chapter 5 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. Parts 1-4 described the implementation of
+the simple Kaleidoscope language and included support for generating
+LLVM IR, followed by optimizations and a JIT compiler. Unfortunately, as
+presented, Kaleidoscope is mostly useless: it has no control flow other
+than call and return. This means that you can't have conditional
+branches in the code, significantly limiting its power. In this episode
+of "build that compiler", we'll extend Kaleidoscope to have an
+if/then/else expression plus a simple 'for' loop.
+
+If/Then/Else
+============
+
+Extending Kaleidoscope to support if/then/else is quite straightforward.
+It basically requires adding lexer support for this "new" concept to the
+lexer, parser, AST, and LLVM code emitter. This example is nice, because
+it shows how easy it is to "grow" a language over time, incrementally
+extending it as new ideas are discovered.
+
+Before we get going on "how" we add this extension, lets talk about
+"what" we want. The basic idea is that we want to be able to write this
+sort of thing:
+
+::
+
+ def fib(x)
+ if x < 3 then
+ 1
+ else
+ fib(x-1)+fib(x-2);
+
+In Kaleidoscope, every construct is an expression: there are no
+statements. As such, the if/then/else expression needs to return a value
+like any other. Since we're using a mostly functional form, we'll have
+it evaluate its conditional, then return the 'then' or 'else' value
+based on how the condition was resolved. This is very similar to the C
+"?:" expression.
+
+The semantics of the if/then/else expression is that it evaluates the
+condition to a boolean equality value: 0.0 is considered to be false and
+everything else is considered to be true. If the condition is true, the
+first subexpression is evaluated and returned, if the condition is
+false, the second subexpression is evaluated and returned. Since
+Kaleidoscope allows side-effects, this behavior is important to nail
+down.
+
+Now that we know what we "want", lets break this down into its
+constituent pieces.
+
+Lexer Extensions for If/Then/Else
+---------------------------------
+
+The lexer extensions are straightforward. First we add new variants for
+the relevant tokens:
+
+.. code-block:: ocaml
+
+ (* control *)
+ | If | Then | Else | For | In
+
+Once we have that, we recognize the new keywords in the lexer. This is
+pretty simple stuff:
+
+.. code-block:: ocaml
+
+ ...
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | "if" -> [< 'Token.If; stream >]
+ | "then" -> [< 'Token.Then; stream >]
+ | "else" -> [< 'Token.Else; stream >]
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+AST Extensions for If/Then/Else
+-------------------------------
+
+To represent the new expression we add a new AST variant for it:
+
+.. code-block:: ocaml
+
+ type expr =
+ ...
+ (* variant for if/then/else. *)
+ | If of expr * expr * expr
+
+The AST variant just has pointers to the various subexpressions.
+
+Parser Extensions for If/Then/Else
+----------------------------------
+
+Now that we have the relevant tokens coming from the lexer and we have
+the AST node to build, our parsing logic is relatively straightforward.
+Next we add a new case for parsing a if-expression as a primary expression:
+
+.. code-block:: ocaml
+
+ let rec parse_primary = parser
+ ...
+ (* ifexpr ::= 'if' expr 'then' expr 'else' expr *)
+ | [< 'Token.If; c=parse_expr;
+ 'Token.Then ?? "expected 'then'"; t=parse_expr;
+ 'Token.Else ?? "expected 'else'"; e=parse_expr >] ->
+ Ast.If (c, t, e)
+
+LLVM IR for If/Then/Else
+------------------------
+
+Now that we have it parsing and building the AST, the final piece is
+adding LLVM code generation support. This is the most interesting part
+of the if/then/else example, because this is where it starts to
+introduce new concepts. All of the code above has been thoroughly
+described in previous chapters.
+
+To motivate the code we want to produce, lets take a look at a simple
+example. Consider:
+
+::
+
+ extern foo();
+ extern bar();
+ def baz(x) if x then foo() else bar();
+
+If you disable optimizations, the code you'll (soon) get from
+Kaleidoscope looks like this:
+
+.. code-block:: llvm
+
+ declare double @foo()
+
+ declare double @bar()
+
+ define double @baz(double %x) {
+ entry:
+ %ifcond = fcmp one double %x, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then: ; preds = %entry
+ %calltmp = call double @foo()
+ br label %ifcont
+
+ else: ; preds = %entry
+ %calltmp1 = call double @bar()
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ %calltmp, %then ], [ %calltmp1, %else ]
+ ret double %iftmp
+ }
+
+To visualize the control flow graph, you can use a nifty feature of the
+LLVM '`opt <http://llvm.org/cmds/opt.html>`_' tool. If you put this LLVM
+IR into "t.ll" and run "``llvm-as < t.ll | opt -analyze -view-cfg``", `a
+window will pop up <../ProgrammersManual.html#viewing-graphs-while-debugging-code>`_ and you'll
+see this graph:
+
+.. figure:: LangImpl05-cfg.png
+ :align: center
+ :alt: Example CFG
+
+ Example CFG
+
+Another way to get this is to call
+"``Llvm_analysis.view_function_cfg f``" or
+"``Llvm_analysis.view_function_cfg_only f``" (where ``f`` is a
+"``Function``") either by inserting actual calls into the code and
+recompiling or by calling these in the debugger. LLVM has many nice
+features for visualizing various graphs.
+
+Getting back to the generated code, it is fairly simple: the entry block
+evaluates the conditional expression ("x" in our case here) and compares
+the result to 0.0 with the "``fcmp one``" instruction ('one' is "Ordered
+and Not Equal"). Based on the result of this expression, the code jumps
+to either the "then" or "else" blocks, which contain the expressions for
+the true/false cases.
+
+Once the then/else blocks are finished executing, they both branch back
+to the 'ifcont' block to execute the code that happens after the
+if/then/else. In this case the only thing left to do is to return to the
+caller of the function. The question then becomes: how does the code
+know which expression to return?
+
+The answer to this question involves an important SSA operation: the
+`Phi
+operation <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+If you're not familiar with SSA, `the wikipedia
+article <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_
+is a good introduction and there are various other introductions to it
+available on your favorite search engine. The short version is that
+"execution" of the Phi operation requires "remembering" which block
+control came from. The Phi operation takes on the value corresponding to
+the input control block. In this case, if control comes in from the
+"then" block, it gets the value of "calltmp". If control comes from the
+"else" block, it gets the value of "calltmp1".
+
+At this point, you are probably starting to think "Oh no! This means my
+simple and elegant front-end will have to start generating SSA form in
+order to use LLVM!". Fortunately, this is not the case, and we strongly
+advise *not* implementing an SSA construction algorithm in your
+front-end unless there is an amazingly good reason to do so. In
+practice, there are two sorts of values that float around in code
+written for your average imperative programming language that might need
+Phi nodes:
+
+#. Code that involves user variables: ``x = 1; x = x + 1;``
+#. Values that are implicit in the structure of your AST, such as the
+ Phi node in this case.
+
+In `Chapter 7 <OCamlLangImpl7.html>`_ of this tutorial ("mutable
+variables"), we'll talk about #1 in depth. For now, just believe me that
+you don't need SSA construction to handle this case. For #2, you have
+the choice of using the techniques that we will describe for #1, or you
+can insert Phi nodes directly, if convenient. In this case, it is really
+really easy to generate the Phi node, so we choose to do it directly.
+
+Okay, enough of the motivation and overview, lets generate code!
+
+Code Generation for If/Then/Else
+--------------------------------
+
+In order to generate code for this, we implement the ``Codegen`` method
+for ``IfExprAST``:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ ...
+ | Ast.If (cond, then_, else_) ->
+ let cond = codegen_expr cond in
+
+ (* Convert condition to a bool by comparing equal to 0.0 *)
+ let zero = const_float double_type 0.0 in
+ let cond_val = build_fcmp Fcmp.One cond zero "ifcond" builder in
+
+This code is straightforward and similar to what we saw before. We emit
+the expression for the condition, then compare that value to zero to get
+a truth value as a 1-bit (bool) value.
+
+.. code-block:: ocaml
+
+ (* Grab the first block so that we might later add the conditional branch
+ * to it at the end of the function. *)
+ let start_bb = insertion_block builder in
+ let the_function = block_parent start_bb in
+
+ let then_bb = append_block context "then" the_function in
+ position_at_end then_bb builder;
+
+As opposed to the `C++ tutorial <LangImpl05.html>`_, we have to build our
+basic blocks bottom up since we can't have dangling BasicBlocks. We
+start off by saving a pointer to the first block (which might not be the
+entry block), which we'll need to build a conditional branch later. We
+do this by asking the ``builder`` for the current BasicBlock. The fourth
+line gets the current Function object that is being built. It gets this
+by the ``start_bb`` for its "parent" (the function it is currently
+embedded into).
+
+Once it has that, it creates one block. It is automatically appended
+into the function's list of blocks.
+
+.. code-block:: ocaml
+
+ (* Emit 'then' value. *)
+ position_at_end then_bb builder;
+ let then_val = codegen_expr then_ in
+
+ (* Codegen of 'then' can change the current block, update then_bb for the
+ * phi. We create a new name because one is used for the phi node, and the
+ * other is used for the conditional branch. *)
+ let new_then_bb = insertion_block builder in
+
+We move the builder to start inserting into the "then" block. Strictly
+speaking, this call moves the insertion point to be at the end of the
+specified block. However, since the "then" block is empty, it also
+starts out by inserting at the beginning of the block. :)
+
+Once the insertion point is set, we recursively codegen the "then"
+expression from the AST.
+
+The final line here is quite subtle, but is very important. The basic
+issue is that when we create the Phi node in the merge block, we need to
+set up the block/value pairs that indicate how the Phi will work.
+Importantly, the Phi node expects to have an entry for each predecessor
+of the block in the CFG. Why then, are we getting the current block when
+we just set it to ThenBB 5 lines above? The problem is that the "Then"
+expression may actually itself change the block that the Builder is
+emitting into if, for example, it contains a nested "if/then/else"
+expression. Because calling Codegen recursively could arbitrarily change
+the notion of the current block, we are required to get an up-to-date
+value for code that will set up the Phi node.
+
+.. code-block:: ocaml
+
+ (* Emit 'else' value. *)
+ let else_bb = append_block context "else" the_function in
+ position_at_end else_bb builder;
+ let else_val = codegen_expr else_ in
+
+ (* Codegen of 'else' can change the current block, update else_bb for the
+ * phi. *)
+ let new_else_bb = insertion_block builder in
+
+Code generation for the 'else' block is basically identical to codegen
+for the 'then' block.
+
+.. code-block:: ocaml
+
+ (* Emit merge block. *)
+ let merge_bb = append_block context "ifcont" the_function in
+ position_at_end merge_bb builder;
+ let incoming = [(then_val, new_then_bb); (else_val, new_else_bb)] in
+ let phi = build_phi incoming "iftmp" builder in
+
+The first two lines here are now familiar: the first adds the "merge"
+block to the Function object. The second changes the insertion
+point so that newly created code will go into the "merge" block. Once
+that is done, we need to create the PHI node and set up the block/value
+pairs for the PHI.
+
+.. code-block:: ocaml
+
+ (* Return to the start block to add the conditional branch. *)
+ position_at_end start_bb builder;
+ ignore (build_cond_br cond_val then_bb else_bb builder);
+
+Once the blocks are created, we can emit the conditional branch that
+chooses between them. Note that creating new blocks does not implicitly
+affect the IRBuilder, so it is still inserting into the block that the
+condition went into. This is why we needed to save the "start" block.
+
+.. code-block:: ocaml
+
+ (* Set a unconditional branch at the end of the 'then' block and the
+ * 'else' block to the 'merge' block. *)
+ position_at_end new_then_bb builder; ignore (build_br merge_bb builder);
+ position_at_end new_else_bb builder; ignore (build_br merge_bb builder);
+
+ (* Finally, set the builder to the end of the merge block. *)
+ position_at_end merge_bb builder;
+
+ phi
+
+To finish off the blocks, we create an unconditional branch to the merge
+block. One interesting (and very important) aspect of the LLVM IR is
+that it `requires all basic blocks to be
+"terminated" <../LangRef.html#functionstructure>`_ with a `control flow
+instruction <../LangRef.html#terminators>`_ such as return or branch.
+This means that all control flow, *including fall throughs* must be made
+explicit in the LLVM IR. If you violate this rule, the verifier will
+emit an error.
+
+Finally, the CodeGen function returns the phi node as the value computed
+by the if/then/else expression. In our example above, this returned
+value will feed into the code for the top-level function, which will
+create the return instruction.
+
+Overall, we now have the ability to execute conditional code in
+Kaleidoscope. With this extension, Kaleidoscope is a fairly complete
+language that can calculate a wide variety of numeric functions. Next up
+we'll add another useful expression that is familiar from non-functional
+languages...
+
+'for' Loop Expression
+=====================
+
+Now that we know how to add basic control flow constructs to the
+language, we have the tools to add more powerful things. Lets add
+something more aggressive, a 'for' expression:
+
+::
+
+ extern putchard(char);
+ def printstar(n)
+ for i = 1, i < n, 1.0 in
+ putchard(42); # ascii 42 = '*'
+
+ # print 100 '*' characters
+ printstar(100);
+
+This expression defines a new variable ("i" in this case) which iterates
+from a starting value, while the condition ("i < n" in this case) is
+true, incrementing by an optional step value ("1.0" in this case). If
+the step value is omitted, it defaults to 1.0. While the loop is true,
+it executes its body expression. Because we don't have anything better
+to return, we'll just define the loop as always returning 0.0. In the
+future when we have mutable variables, it will get more useful.
+
+As before, lets talk about the changes that we need to Kaleidoscope to
+support this.
+
+Lexer Extensions for the 'for' Loop
+-----------------------------------
+
+The lexer extensions are the same sort of thing as for if/then/else:
+
+.. code-block:: ocaml
+
+ ... in Token.token ...
+ (* control *)
+ | If | Then | Else
+ | For | In
+
+ ... in Lexer.lex_ident...
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | "if" -> [< 'Token.If; stream >]
+ | "then" -> [< 'Token.Then; stream >]
+ | "else" -> [< 'Token.Else; stream >]
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+AST Extensions for the 'for' Loop
+---------------------------------
+
+The AST variant is just as simple. It basically boils down to capturing
+the variable name and the constituent expressions in the node.
+
+.. code-block:: ocaml
+
+ type expr =
+ ...
+ (* variant for for/in. *)
+ | For of string * expr * expr * expr option * expr
+
+Parser Extensions for the 'for' Loop
+------------------------------------
+
+The parser code is also fairly standard. The only interesting thing here
+is handling of the optional step value. The parser code handles it by
+checking to see if the second comma is present. If not, it sets the step
+value to null in the AST node:
+
+.. code-block:: ocaml
+
+ let rec parse_primary = parser
+ ...
+ (* forexpr
+ ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression *)
+ | [< 'Token.For;
+ 'Token.Ident id ?? "expected identifier after for";
+ 'Token.Kwd '=' ?? "expected '=' after for";
+ stream >] ->
+ begin parser
+ | [<
+ start=parse_expr;
+ 'Token.Kwd ',' ?? "expected ',' after for";
+ end_=parse_expr;
+ stream >] ->
+ let step =
+ begin parser
+ | [< 'Token.Kwd ','; step=parse_expr >] -> Some step
+ | [< >] -> None
+ end stream
+ in
+ begin parser
+ | [< 'Token.In; body=parse_expr >] ->
+ Ast.For (id, start, end_, step, body)
+ | [< >] ->
+ raise (Stream.Error "expected 'in' after for")
+ end stream
+ | [< >] ->
+ raise (Stream.Error "expected '=' after for")
+ end stream
+
+LLVM IR for the 'for' Loop
+--------------------------
+
+Now we get to the good part: the LLVM IR we want to generate for this
+thing. With the simple example above, we get this LLVM IR (note that
+this dump is generated with optimizations disabled for clarity):
+
+.. code-block:: llvm
+
+ declare double @putchard(double)
+
+ define double @printstar(double %n) {
+ entry:
+ ; initial value = 1.0 (inlined into phi)
+ br label %loop
+
+ loop: ; preds = %loop, %entry
+ %i = phi double [ 1.000000e+00, %entry ], [ %nextvar, %loop ]
+ ; body
+ %calltmp = call double @putchard(double 4.200000e+01)
+ ; increment
+ %nextvar = fadd double %i, 1.000000e+00
+
+ ; termination test
+ %cmptmp = fcmp ult double %i, %n
+ %booltmp = uitofp i1 %cmptmp to double
+ %loopcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %loopcond, label %loop, label %afterloop
+
+ afterloop: ; preds = %loop
+ ; loop always returns 0.0
+ ret double 0.000000e+00
+ }
+
+This loop contains all the same constructs we saw before: a phi node,
+several expressions, and some basic blocks. Lets see how this fits
+together.
+
+Code Generation for the 'for' Loop
+----------------------------------
+
+The first part of Codegen is very simple: we just output the start
+expression for the loop value:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ ...
+ | Ast.For (var_name, start, end_, step, body) ->
+ (* Emit the start code first, without 'variable' in scope. *)
+ let start_val = codegen_expr start in
+
+With this out of the way, the next step is to set up the LLVM basic
+block for the start of the loop body. In the case above, the whole loop
+body is one block, but remember that the body code itself could consist
+of multiple blocks (e.g. if it contains an if/then/else or a for/in
+expression).
+
+.. code-block:: ocaml
+
+ (* Make the new basic block for the loop header, inserting after current
+ * block. *)
+ let preheader_bb = insertion_block builder in
+ let the_function = block_parent preheader_bb in
+ let loop_bb = append_block context "loop" the_function in
+
+ (* Insert an explicit fall through from the current block to the
+ * loop_bb. *)
+ ignore (build_br loop_bb builder);
+
+This code is similar to what we saw for if/then/else. Because we will
+need it to create the Phi node, we remember the block that falls through
+into the loop. Once we have that, we create the actual block that starts
+the loop and create an unconditional branch for the fall-through between
+the two blocks.
+
+.. code-block:: ocaml
+
+ (* Start insertion in loop_bb. *)
+ position_at_end loop_bb builder;
+
+ (* Start the PHI node with an entry for start. *)
+ let variable = build_phi [(start_val, preheader_bb)] var_name builder in
+
+Now that the "preheader" for the loop is set up, we switch to emitting
+code for the loop body. To begin with, we move the insertion point and
+create the PHI node for the loop induction variable. Since we already
+know the incoming value for the starting value, we add it to the Phi
+node. Note that the Phi will eventually get a second value for the
+backedge, but we can't set it up yet (because it doesn't exist!).
+
+.. code-block:: ocaml
+
+ (* Within the loop, the variable is defined equal to the PHI node. If it
+ * shadows an existing variable, we have to restore it, so save it
+ * now. *)
+ let old_val =
+ try Some (Hashtbl.find named_values var_name) with Not_found -> None
+ in
+ Hashtbl.add named_values var_name variable;
+
+ (* Emit the body of the loop. This, like any other expr, can change the
+ * current BB. Note that we ignore the value computed by the body, but
+ * don't allow an error *)
+ ignore (codegen_expr body);
+
+Now the code starts to get more interesting. Our 'for' loop introduces a
+new variable to the symbol table. This means that our symbol table can
+now contain either function arguments or loop variables. To handle this,
+before we codegen the body of the loop, we add the loop variable as the
+current value for its name. Note that it is possible that there is a
+variable of the same name in the outer scope. It would be easy to make
+this an error (emit an error and return null if there is already an
+entry for VarName) but we choose to allow shadowing of variables. In
+order to handle this correctly, we remember the Value that we are
+potentially shadowing in ``old_val`` (which will be None if there is no
+shadowed variable).
+
+Once the loop variable is set into the symbol table, the code
+recursively codegen's the body. This allows the body to use the loop
+variable: any references to it will naturally find it in the symbol
+table.
+
+.. code-block:: ocaml
+
+ (* Emit the step value. *)
+ let step_val =
+ match step with
+ | Some step -> codegen_expr step
+ (* If not specified, use 1.0. *)
+ | None -> const_float double_type 1.0
+ in
+
+ let next_var = build_add variable step_val "nextvar" builder in
+
+Now that the body is emitted, we compute the next value of the iteration
+variable by adding the step value, or 1.0 if it isn't present.
+'``next_var``' will be the value of the loop variable on the next
+iteration of the loop.
+
+.. code-block:: ocaml
+
+ (* Compute the end condition. *)
+ let end_cond = codegen_expr end_ in
+
+ (* Convert condition to a bool by comparing equal to 0.0. *)
+ let zero = const_float double_type 0.0 in
+ let end_cond = build_fcmp Fcmp.One end_cond zero "loopcond" builder in
+
+Finally, we evaluate the exit value of the loop, to determine whether
+the loop should exit. This mirrors the condition evaluation for the
+if/then/else statement.
+
+.. code-block:: ocaml
+
+ (* Create the "after loop" block and insert it. *)
+ let loop_end_bb = insertion_block builder in
+ let after_bb = append_block context "afterloop" the_function in
+
+ (* Insert the conditional branch into the end of loop_end_bb. *)
+ ignore (build_cond_br end_cond loop_bb after_bb builder);
+
+ (* Any new code will be inserted in after_bb. *)
+ position_at_end after_bb builder;
+
+With the code for the body of the loop complete, we just need to finish
+up the control flow for it. This code remembers the end block (for the
+phi node), then creates the block for the loop exit ("afterloop"). Based
+on the value of the exit condition, it creates a conditional branch that
+chooses between executing the loop again and exiting the loop. Any
+future code is emitted in the "afterloop" block, so it sets the
+insertion position to it.
+
+.. code-block:: ocaml
+
+ (* Add a new entry to the PHI node for the backedge. *)
+ add_incoming (next_var, loop_end_bb) variable;
+
+ (* Restore the unshadowed variable. *)
+ begin match old_val with
+ | Some old_val -> Hashtbl.add named_values var_name old_val
+ | None -> ()
+ end;
+
+ (* for expr always returns 0.0. *)
+ const_null double_type
+
+The final code handles various cleanups: now that we have the
+"``next_var``" value, we can add the incoming value to the loop PHI
+node. After that, we remove the loop variable from the symbol table, so
+that it isn't in scope after the for loop. Finally, code generation of
+the for loop always returns 0.0, so that is what we return from
+``Codegen.codegen_expr``.
+
+With this, we conclude the "adding control flow to Kaleidoscope" chapter
+of the tutorial. In this chapter we added two control flow constructs,
+and used them to motivate a couple of aspects of the LLVM IR that are
+important for front-end implementors to know. In the next chapter of our
+saga, we will get a bit crazier and add `user-defined
+operators <OCamlLangImpl6.html>`_ to our poor innocent language.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the if/then/else and for expressions.. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+ <*.{byte,native}>: g++, use_llvm, use_llvm_analysis
+ <*.{byte,native}>: use_llvm_executionengine, use_llvm_target
+ <*.{byte,native}>: use_llvm_scalar_opts, use_bindings
+
+myocamlbuild.ml:
+ .. code-block:: ocaml
+
+ open Ocamlbuild_plugin;;
+
+ ocaml_lib ~extern:true "llvm";;
+ ocaml_lib ~extern:true "llvm_analysis";;
+ ocaml_lib ~extern:true "llvm_executionengine";;
+ ocaml_lib ~extern:true "llvm_target";;
+ ocaml_lib ~extern:true "llvm_scalar_opts";;
+
+ flag ["link"; "ocaml"; "g++"] (S[A"-cc"; A"g++"]);;
+ dep ["link"; "ocaml"; "use_bindings"] ["bindings.o"];;
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+ (* control *)
+ | If | Then | Else
+ | For | In
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | "if" -> [< 'Token.If; stream >]
+ | "then" -> [< 'Token.Then; stream >]
+ | "else" -> [< 'Token.Else; stream >]
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* variant for if/then/else. *)
+ | If of expr * expr * expr
+
+ (* variant for for/in. *)
+ | For of string * expr * expr * expr option * expr
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto = Prototype of string * string array
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr
+ * ::= ifexpr
+ * ::= forexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ (* ifexpr ::= 'if' expr 'then' expr 'else' expr *)
+ | [< 'Token.If; c=parse_expr;
+ 'Token.Then ?? "expected 'then'"; t=parse_expr;
+ 'Token.Else ?? "expected 'else'"; e=parse_expr >] ->
+ Ast.If (c, t, e)
+
+ (* forexpr
+ ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression *)
+ | [< 'Token.For;
+ 'Token.Ident id ?? "expected identifier after for";
+ 'Token.Kwd '=' ?? "expected '=' after for";
+ stream >] ->
+ begin parser
+ | [<
+ start=parse_expr;
+ 'Token.Kwd ',' ?? "expected ',' after for";
+ end_=parse_expr;
+ stream >] ->
+ let step =
+ begin parser
+ | [< 'Token.Kwd ','; step=parse_expr >] -> Some step
+ | [< >] -> None
+ end stream
+ in
+ begin parser
+ | [< 'Token.In; body=parse_expr >] ->
+ Ast.For (id, start, end_, step, body)
+ | [< >] ->
+ raise (Stream.Error "expected 'in' after for")
+ end stream
+ | [< >] ->
+ raise (Stream.Error "expected '=' after for")
+ end stream
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator. *)
+ let rhs = parse_primary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_primary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')' *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+codegen.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Code Generation
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+ let rec codegen_expr = function
+ | Ast.Number n -> const_float double_type n
+ | Ast.Variable name ->
+ (try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name"))
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ -> raise (Error "invalid binary operator")
+ end
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+ | Ast.If (cond, then_, else_) ->
+ let cond = codegen_expr cond in
+
+ (* Convert condition to a bool by comparing equal to 0.0 *)
+ let zero = const_float double_type 0.0 in
+ let cond_val = build_fcmp Fcmp.One cond zero "ifcond" builder in
+
+ (* Grab the first block so that we might later add the conditional branch
+ * to it at the end of the function. *)
+ let start_bb = insertion_block builder in
+ let the_function = block_parent start_bb in
+
+ let then_bb = append_block context "then" the_function in
+
+ (* Emit 'then' value. *)
+ position_at_end then_bb builder;
+ let then_val = codegen_expr then_ in
+
+ (* Codegen of 'then' can change the current block, update then_bb for the
+ * phi. We create a new name because one is used for the phi node, and the
+ * other is used for the conditional branch. *)
+ let new_then_bb = insertion_block builder in
+
+ (* Emit 'else' value. *)
+ let else_bb = append_block context "else" the_function in
+ position_at_end else_bb builder;
+ let else_val = codegen_expr else_ in
+
+ (* Codegen of 'else' can change the current block, update else_bb for the
+ * phi. *)
+ let new_else_bb = insertion_block builder in
+
+ (* Emit merge block. *)
+ let merge_bb = append_block context "ifcont" the_function in
+ position_at_end merge_bb builder;
+ let incoming = [(then_val, new_then_bb); (else_val, new_else_bb)] in
+ let phi = build_phi incoming "iftmp" builder in
+
+ (* Return to the start block to add the conditional branch. *)
+ position_at_end start_bb builder;
+ ignore (build_cond_br cond_val then_bb else_bb builder);
+
+ (* Set a unconditional branch at the end of the 'then' block and the
+ * 'else' block to the 'merge' block. *)
+ position_at_end new_then_bb builder; ignore (build_br merge_bb builder);
+ position_at_end new_else_bb builder; ignore (build_br merge_bb builder);
+
+ (* Finally, set the builder to the end of the merge block. *)
+ position_at_end merge_bb builder;
+
+ phi
+ | Ast.For (var_name, start, end_, step, body) ->
+ (* Emit the start code first, without 'variable' in scope. *)
+ let start_val = codegen_expr start in
+
+ (* Make the new basic block for the loop header, inserting after current
+ * block. *)
+ let preheader_bb = insertion_block builder in
+ let the_function = block_parent preheader_bb in
+ let loop_bb = append_block context "loop" the_function in
+
+ (* Insert an explicit fall through from the current block to the
+ * loop_bb. *)
+ ignore (build_br loop_bb builder);
+
+ (* Start insertion in loop_bb. *)
+ position_at_end loop_bb builder;
+
+ (* Start the PHI node with an entry for start. *)
+ let variable = build_phi [(start_val, preheader_bb)] var_name builder in
+
+ (* Within the loop, the variable is defined equal to the PHI node. If it
+ * shadows an existing variable, we have to restore it, so save it
+ * now. *)
+ let old_val =
+ try Some (Hashtbl.find named_values var_name) with Not_found -> None
+ in
+ Hashtbl.add named_values var_name variable;
+
+ (* Emit the body of the loop. This, like any other expr, can change the
+ * current BB. Note that we ignore the value computed by the body, but
+ * don't allow an error *)
+ ignore (codegen_expr body);
+
+ (* Emit the step value. *)
+ let step_val =
+ match step with
+ | Some step -> codegen_expr step
+ (* If not specified, use 1.0. *)
+ | None -> const_float double_type 1.0
+ in
+
+ let next_var = build_add variable step_val "nextvar" builder in
+
+ (* Compute the end condition. *)
+ let end_cond = codegen_expr end_ in
+
+ (* Convert condition to a bool by comparing equal to 0.0. *)
+ let zero = const_float double_type 0.0 in
+ let end_cond = build_fcmp Fcmp.One end_cond zero "loopcond" builder in
+
+ (* Create the "after loop" block and insert it. *)
+ let loop_end_bb = insertion_block builder in
+ let after_bb = append_block context "afterloop" the_function in
+
+ (* Insert the conditional branch into the end of loop_end_bb. *)
+ ignore (build_cond_br end_cond loop_bb after_bb builder);
+
+ (* Any new code will be inserted in after_bb. *)
+ position_at_end after_bb builder;
+
+ (* Add a new entry to the PHI node for the backedge. *)
+ add_incoming (next_var, loop_end_bb) variable;
+
+ (* Restore the unshadowed variable. *)
+ begin match old_val with
+ | Some old_val -> Hashtbl.add named_values var_name old_val
+ | None -> ()
+ end;
+
+ (* for expr always returns 0.0. *)
+ const_null double_type
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+ | None -> declare_function name ft the_module
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if block_begin f <> At_end f then
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if element_type (type_of f) <> ft then
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+ let codegen_func the_fpm = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ (* Optimize the function. *)
+ let _ = PassManager.run_function the_function the_fpm in
+
+ the_function
+ with e ->
+ delete_function the_function;
+ raise e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop the_fpm the_execution_engine stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop the_fpm the_execution_engine stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ let e = Parser.parse_definition stream in
+ print_endline "parsed a function definition.";
+ dump_value (Codegen.codegen_func the_fpm e);
+ | Token.Extern ->
+ let e = Parser.parse_extern stream in
+ print_endline "parsed an extern.";
+ dump_value (Codegen.codegen_proto e);
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ let the_function = Codegen.codegen_func the_fpm e in
+ dump_value the_function;
+
+ (* JIT the function, returning a function pointer. *)
+ let result = ExecutionEngine.run_function the_function [||]
+ the_execution_engine in
+
+ print_string "Evaluated to ";
+ print_float (GenericValue.as_float Codegen.double_type result);
+ print_newline ();
+ with Stream.Error s | Codegen.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop the_fpm the_execution_engine stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+ open Llvm_target
+ open Llvm_scalar_opts
+
+ let main () =
+ ignore (initialize_native_target ());
+
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combination the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+ (* Eliminate Common SubExpressions. *)
+ add_gvn the_fpm;
+
+ (* Simplify the control flow graph (deleting unreachable blocks, etc). *)
+ add_cfg_simplification the_fpm;
+
+ ignore (PassManager.initialize the_fpm);
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop the_fpm the_execution_engine stream;
+
+ (* Print out all the generated code. *)
+ dump_module Codegen.the_module
+ ;;
+
+ main ()
+
+bindings.c
+ .. code-block:: c
+
+ #include <stdio.h>
+
+ /* putchard - putchar that takes a double and returns 0. */
+ extern double putchard(double X) {
+ putchar((char)X);
+ return 0;
+ }
+
+`Next: Extending the language: user-defined
+operators <OCamlLangImpl6.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl6.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl6.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl6.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl6.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,1441 @@
+============================================================
+Kaleidoscope: Extending the Language: User-defined Operators
+============================================================
+
+.. contents::
+ :local:
+
+Chapter 6 Introduction
+======================
+
+Welcome to Chapter 6 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. At this point in our tutorial, we now
+have a fully functional language that is fairly minimal, but also
+useful. There is still one big problem with it, however. Our language
+doesn't have many useful operators (like division, logical negation, or
+even any comparisons besides less-than).
+
+This chapter of the tutorial takes a wild digression into adding
+user-defined operators to the simple and beautiful Kaleidoscope
+language. This digression now gives us a simple and ugly language in
+some ways, but also a powerful one at the same time. One of the great
+things about creating your own language is that you get to decide what
+is good or bad. In this tutorial we'll assume that it is okay to use
+this as a way to show some interesting parsing techniques.
+
+At the end of this tutorial, we'll run through an example Kaleidoscope
+application that `renders the Mandelbrot set <#kicking-the-tires>`_. This gives an
+example of what you can build with Kaleidoscope and its feature set.
+
+User-defined Operators: the Idea
+================================
+
+The "operator overloading" that we will add to Kaleidoscope is more
+general than languages like C++. In C++, you are only allowed to
+redefine existing operators: you can't programmatically change the
+grammar, introduce new operators, change precedence levels, etc. In this
+chapter, we will add this capability to Kaleidoscope, which will let the
+user round out the set of operators that are supported.
+
+The point of going into user-defined operators in a tutorial like this
+is to show the power and flexibility of using a hand-written parser.
+Thus far, the parser we have been implementing uses recursive descent
+for most parts of the grammar and operator precedence parsing for the
+expressions. See `Chapter 2 <OCamlLangImpl2.html>`_ for details. Without
+using operator precedence parsing, it would be very difficult to allow
+the programmer to introduce new operators into the grammar: the grammar
+is dynamically extensible as the JIT runs.
+
+The two specific features we'll add are programmable unary operators
+(right now, Kaleidoscope has no unary operators at all) as well as
+binary operators. An example of this is:
+
+::
+
+ # Logical unary not.
+ def unary!(v)
+ if v then
+ 0
+ else
+ 1;
+
+ # Define > with the same precedence as <.
+ def binary> 10 (LHS RHS)
+ RHS < LHS;
+
+ # Binary "logical or", (note that it does not "short circuit")
+ def binary| 5 (LHS RHS)
+ if LHS then
+ 1
+ else if RHS then
+ 1
+ else
+ 0;
+
+ # Define = with slightly lower precedence than relationals.
+ def binary= 9 (LHS RHS)
+ !(LHS < RHS | LHS > RHS);
+
+Many languages aspire to being able to implement their standard runtime
+library in the language itself. In Kaleidoscope, we can implement
+significant parts of the language in the library!
+
+We will break down implementation of these features into two parts:
+implementing support for user-defined binary operators and adding unary
+operators.
+
+User-defined Binary Operators
+=============================
+
+Adding support for user-defined binary operators is pretty simple with
+our current framework. We'll first add support for the unary/binary
+keywords:
+
+.. code-block:: ocaml
+
+ type token =
+ ...
+ (* operators *)
+ | Binary | Unary
+
+ ...
+
+ and lex_ident buffer = parser
+ ...
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | "binary" -> [< 'Token.Binary; stream >]
+ | "unary" -> [< 'Token.Unary; stream >]
+
+This just adds lexer support for the unary and binary keywords, like we
+did in `previous chapters <OCamlLangImpl5.html#lexer-extensions-for-if-then-else>`_. One nice
+thing about our current AST, is that we represent binary operators with
+full generalisation by using their ASCII code as the opcode. For our
+extended operators, we'll use this same representation, so we don't need
+any new AST or parser support.
+
+On the other hand, we have to be able to represent the definitions of
+these new operators, in the "def binary\| 5" part of the function
+definition. In our grammar so far, the "name" for the function
+definition is parsed as the "prototype" production and into the
+``Ast.Prototype`` AST node. To represent our new user-defined operators
+as prototypes, we have to extend the ``Ast.Prototype`` AST node like
+this:
+
+.. code-block:: ocaml
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto =
+ | Prototype of string * string array
+ | BinOpPrototype of string * string array * int
+
+Basically, in addition to knowing a name for the prototype, we now keep
+track of whether it was an operator, and if it was, what precedence
+level the operator is at. The precedence is only used for binary
+operators (as you'll see below, it just doesn't apply for unary
+operators). Now that we have a way to represent the prototype for a
+user-defined operator, we need to parse it:
+
+.. code-block:: ocaml
+
+ (* prototype
+ * ::= id '(' id* ')'
+ * ::= binary LETTER number? (id, id)
+ * ::= unary LETTER number? (id) *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+ let parse_operator = parser
+ | [< 'Token.Unary >] -> "unary", 1
+ | [< 'Token.Binary >] -> "binary", 2
+ in
+ let parse_binary_precedence = parser
+ | [< 'Token.Number n >] -> int_of_float n
+ | [< >] -> 30
+ in
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+ | [< (prefix, kind)=parse_operator;
+ 'Token.Kwd op ?? "expected an operator";
+ (* Read the precedence if present. *)
+ binary_precedence=parse_binary_precedence;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ let name = prefix ^ (String.make 1 op) in
+ let args = Array.of_list (List.rev args) in
+
+ (* Verify right number of arguments for operator. *)
+ if Array.length args != kind
+ then raise (Stream.Error "invalid number of operands for operator")
+ else
+ if kind == 1 then
+ Ast.Prototype (name, args)
+ else
+ Ast.BinOpPrototype (name, args, binary_precedence)
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+This is all fairly straightforward parsing code, and we have already
+seen a lot of similar code in the past. One interesting part about the
+code above is the couple lines that set up ``name`` for binary
+operators. This builds names like "binary@" for a newly defined "@"
+operator. This then takes advantage of the fact that symbol names in the
+LLVM symbol table are allowed to have any character in them, including
+embedded nul characters.
+
+The next interesting thing to add, is codegen support for these binary
+operators. Given our current structure, this is a simple addition of a
+default case for our existing binary operator node:
+
+.. code-block:: ocaml
+
+ let codegen_expr = function
+ ...
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ ->
+ (* If it wasn't a builtin binary operator, it must be a user defined
+ * one. Emit a call to it. *)
+ let callee = "binary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "binary operator not found!")
+ in
+ build_call callee [|lhs_val; rhs_val|] "binop" builder
+ end
+
+As you can see above, the new code is actually really simple. It just
+does a lookup for the appropriate operator in the symbol table and
+generates a function call to it. Since user-defined operators are just
+built as normal functions (because the "prototype" boils down to a
+function with the right name) everything falls into place.
+
+The final piece of code we are missing, is a bit of top level magic:
+
+.. code-block:: ocaml
+
+ let codegen_func the_fpm = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* If this is an operator, install it. *)
+ begin match proto with
+ | Ast.BinOpPrototype (name, args, prec) ->
+ let op = name.[String.length name - 1] in
+ Hashtbl.add Parser.binop_precedence op prec;
+ | _ -> ()
+ end;
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+ ...
+
+Basically, before codegening a function, if it is a user-defined
+operator, we register it in the precedence table. This allows the binary
+operator parsing logic we already have in place to handle it. Since we
+are working on a fully-general operator precedence parser, this is all
+we need to do to "extend the grammar".
+
+Now we have useful user-defined binary operators. This builds a lot on
+the previous framework we built for other operators. Adding unary
+operators is a bit more challenging, because we don't have any framework
+for it yet - lets see what it takes.
+
+User-defined Unary Operators
+============================
+
+Since we don't currently support unary operators in the Kaleidoscope
+language, we'll need to add everything to support them. Above, we added
+simple support for the 'unary' keyword to the lexer. In addition to
+that, we need an AST node:
+
+.. code-block:: ocaml
+
+ type expr =
+ ...
+ (* variant for a unary operator. *)
+ | Unary of char * expr
+ ...
+
+This AST node is very simple and obvious by now. It directly mirrors the
+binary operator AST node, except that it only has one child. With this,
+we need to add the parsing logic. Parsing a unary operator is pretty
+simple: we'll add a new function to do it:
+
+.. code-block:: ocaml
+
+ (* unary
+ * ::= primary
+ * ::= '!' unary *)
+ and parse_unary = parser
+ (* If this is a unary operator, read it. *)
+ | [< 'Token.Kwd op when op != '(' && op != ')'; operand=parse_expr >] ->
+ Ast.Unary (op, operand)
+
+ (* If the current token is not an operator, it must be a primary expr. *)
+ | [< stream >] -> parse_primary stream
+
+The grammar we add is pretty straightforward here. If we see a unary
+operator when parsing a primary operator, we eat the operator as a
+prefix and parse the remaining piece as another unary operator. This
+allows us to handle multiple unary operators (e.g. "!!x"). Note that
+unary operators can't have ambiguous parses like binary operators can,
+so there is no need for precedence information.
+
+The problem with this function, is that we need to call ParseUnary from
+somewhere. To do this, we change previous callers of ParsePrimary to
+call ``parse_unary`` instead:
+
+.. code-block:: ocaml
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ ...
+ (* Parse the unary expression after the binary operator. *)
+ let rhs = parse_unary stream in
+ ...
+
+ ...
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_unary; stream >] -> parse_bin_rhs 0 lhs stream
+
+With these two simple changes, we are now able to parse unary operators
+and build the AST for them. Next up, we need to add parser support for
+prototypes, to parse the unary operator prototype. We extend the binary
+operator code above with:
+
+.. code-block:: ocaml
+
+ (* prototype
+ * ::= id '(' id* ')'
+ * ::= binary LETTER number? (id, id)
+ * ::= unary LETTER number? (id) *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+ let parse_operator = parser
+ | [< 'Token.Unary >] -> "unary", 1
+ | [< 'Token.Binary >] -> "binary", 2
+ in
+ let parse_binary_precedence = parser
+ | [< 'Token.Number n >] -> int_of_float n
+ | [< >] -> 30
+ in
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+ | [< (prefix, kind)=parse_operator;
+ 'Token.Kwd op ?? "expected an operator";
+ (* Read the precedence if present. *)
+ binary_precedence=parse_binary_precedence;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ let name = prefix ^ (String.make 1 op) in
+ let args = Array.of_list (List.rev args) in
+
+ (* Verify right number of arguments for operator. *)
+ if Array.length args != kind
+ then raise (Stream.Error "invalid number of operands for operator")
+ else
+ if kind == 1 then
+ Ast.Prototype (name, args)
+ else
+ Ast.BinOpPrototype (name, args, binary_precedence)
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+As with binary operators, we name unary operators with a name that
+includes the operator character. This assists us at code generation
+time. Speaking of, the final piece we need to add is codegen support for
+unary operators. It looks like this:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ ...
+ | Ast.Unary (op, operand) ->
+ let operand = codegen_expr operand in
+ let callee = "unary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown unary operator")
+ in
+ build_call callee [|operand|] "unop" builder
+
+This code is similar to, but simpler than, the code for binary
+operators. It is simpler primarily because it doesn't need to handle any
+predefined operators.
+
+Kicking the Tires
+=================
+
+It is somewhat hard to believe, but with a few simple extensions we've
+covered in the last chapters, we have grown a real-ish language. With
+this, we can do a lot of interesting things, including I/O, math, and a
+bunch of other things. For example, we can now add a nice sequencing
+operator (printd is defined to print out the specified value and a
+newline):
+
+::
+
+ ready> extern printd(x);
+ Read extern: declare double @printd(double)
+ ready> def binary : 1 (x y) 0; # Low-precedence operator that ignores operands.
+ ..
+ ready> printd(123) : printd(456) : printd(789);
+ 123.000000
+ 456.000000
+ 789.000000
+ Evaluated to 0.000000
+
+We can also define a bunch of other "primitive" operations, such as:
+
+::
+
+ # Logical unary not.
+ def unary!(v)
+ if v then
+ 0
+ else
+ 1;
+
+ # Unary negate.
+ def unary-(v)
+ 0-v;
+
+ # Define > with the same precedence as <.
+ def binary> 10 (LHS RHS)
+ RHS < LHS;
+
+ # Binary logical or, which does not short circuit.
+ def binary| 5 (LHS RHS)
+ if LHS then
+ 1
+ else if RHS then
+ 1
+ else
+ 0;
+
+ # Binary logical and, which does not short circuit.
+ def binary& 6 (LHS RHS)
+ if !LHS then
+ 0
+ else
+ !!RHS;
+
+ # Define = with slightly lower precedence than relationals.
+ def binary = 9 (LHS RHS)
+ !(LHS < RHS | LHS > RHS);
+
+Given the previous if/then/else support, we can also define interesting
+functions for I/O. For example, the following prints out a character
+whose "density" reflects the value passed in: the lower the value, the
+denser the character:
+
+::
+
+ ready>
+
+ extern putchard(char)
+ def printdensity(d)
+ if d > 8 then
+ putchard(32) # ' '
+ else if d > 4 then
+ putchard(46) # '.'
+ else if d > 2 then
+ putchard(43) # '+'
+ else
+ putchard(42); # '*'
+ ...
+ ready> printdensity(1): printdensity(2): printdensity(3) :
+ printdensity(4): printdensity(5): printdensity(9): putchard(10);
+ *++..
+ Evaluated to 0.000000
+
+Based on these simple primitive operations, we can start to define more
+interesting things. For example, here's a little function that solves
+for the number of iterations it takes a function in the complex plane to
+converge:
+
+::
+
+ # determine whether the specific location diverges.
+ # Solve for z = z^2 + c in the complex plane.
+ def mandelconverger(real imag iters creal cimag)
+ if iters > 255 | (real*real + imag*imag > 4) then
+ iters
+ else
+ mandelconverger(real*real - imag*imag + creal,
+ 2*real*imag + cimag,
+ iters+1, creal, cimag);
+
+ # return the number of iterations required for the iteration to escape
+ def mandelconverge(real imag)
+ mandelconverger(real, imag, 0, real, imag);
+
+This "z = z\ :sup:`2`\ + c" function is a beautiful little creature
+that is the basis for computation of the `Mandelbrot
+Set <http://en.wikipedia.org/wiki/Mandelbrot_set>`_. Our
+``mandelconverge`` function returns the number of iterations that it
+takes for a complex orbit to escape, saturating to 255. This is not a
+very useful function by itself, but if you plot its value over a
+two-dimensional plane, you can see the Mandelbrot set. Given that we are
+limited to using putchard here, our amazing graphical output is limited,
+but we can whip together something using the density plotter above:
+
+::
+
+ # compute and plot the mandelbrot set with the specified 2 dimensional range
+ # info.
+ def mandelhelp(xmin xmax xstep ymin ymax ystep)
+ for y = ymin, y < ymax, ystep in (
+ (for x = xmin, x < xmax, xstep in
+ printdensity(mandelconverge(x,y)))
+ : putchard(10)
+ )
+
+ # mandel - This is a convenient helper function for plotting the mandelbrot set
+ # from the specified position with the specified Magnification.
+ def mandel(realstart imagstart realmag imagmag)
+ mandelhelp(realstart, realstart+realmag*78, realmag,
+ imagstart, imagstart+imagmag*40, imagmag);
+
+Given this, we can try plotting out the mandelbrot set! Lets try it out:
+
+::
+
+ ready> mandel(-2.3, -1.3, 0.05, 0.07);
+ *******************************+++++++++++*************************************
+ *************************+++++++++++++++++++++++*******************************
+ **********************+++++++++++++++++++++++++++++****************************
+ *******************+++++++++++++++++++++.. ...++++++++*************************
+ *****************++++++++++++++++++++++.... ...+++++++++***********************
+ ***************+++++++++++++++++++++++..... ...+++++++++*********************
+ **************+++++++++++++++++++++++.... ....+++++++++********************
+ *************++++++++++++++++++++++...... .....++++++++*******************
+ ************+++++++++++++++++++++....... .......+++++++******************
+ ***********+++++++++++++++++++.... ... .+++++++*****************
+ **********+++++++++++++++++....... .+++++++****************
+ *********++++++++++++++........... ...+++++++***************
+ ********++++++++++++............ ...++++++++**************
+ ********++++++++++... .......... .++++++++**************
+ *******+++++++++..... .+++++++++*************
+ *******++++++++...... ..+++++++++*************
+ *******++++++....... ..+++++++++*************
+ *******+++++...... ..+++++++++*************
+ *******.... .... ...+++++++++*************
+ *******.... . ...+++++++++*************
+ *******+++++...... ...+++++++++*************
+ *******++++++....... ..+++++++++*************
+ *******++++++++...... .+++++++++*************
+ *******+++++++++..... ..+++++++++*************
+ ********++++++++++... .......... .++++++++**************
+ ********++++++++++++............ ...++++++++**************
+ *********++++++++++++++.......... ...+++++++***************
+ **********++++++++++++++++........ .+++++++****************
+ **********++++++++++++++++++++.... ... ..+++++++****************
+ ***********++++++++++++++++++++++....... .......++++++++*****************
+ ************+++++++++++++++++++++++...... ......++++++++******************
+ **************+++++++++++++++++++++++.... ....++++++++********************
+ ***************+++++++++++++++++++++++..... ...+++++++++*********************
+ *****************++++++++++++++++++++++.... ...++++++++***********************
+ *******************+++++++++++++++++++++......++++++++*************************
+ *********************++++++++++++++++++++++.++++++++***************************
+ *************************+++++++++++++++++++++++*******************************
+ ******************************+++++++++++++************************************
+ *******************************************************************************
+ *******************************************************************************
+ *******************************************************************************
+ Evaluated to 0.000000
+ ready> mandel(-2, -1, 0.02, 0.04);
+ **************************+++++++++++++++++++++++++++++++++++++++++++++++++++++
+ ***********************++++++++++++++++++++++++++++++++++++++++++++++++++++++++
+ *********************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.
+ *******************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++...
+ *****************+++++++++++++++++++++++++++++++++++++++++++++++++++++++++.....
+ ***************++++++++++++++++++++++++++++++++++++++++++++++++++++++++........
+ **************++++++++++++++++++++++++++++++++++++++++++++++++++++++...........
+ ************+++++++++++++++++++++++++++++++++++++++++++++++++++++..............
+ ***********++++++++++++++++++++++++++++++++++++++++++++++++++........ .
+ **********++++++++++++++++++++++++++++++++++++++++++++++.............
+ ********+++++++++++++++++++++++++++++++++++++++++++..................
+ *******+++++++++++++++++++++++++++++++++++++++.......................
+ ******+++++++++++++++++++++++++++++++++++...........................
+ *****++++++++++++++++++++++++++++++++............................
+ *****++++++++++++++++++++++++++++...............................
+ ****++++++++++++++++++++++++++...... .........................
+ ***++++++++++++++++++++++++......... ...... ...........
+ ***++++++++++++++++++++++............
+ **+++++++++++++++++++++..............
+ **+++++++++++++++++++................
+ *++++++++++++++++++.................
+ *++++++++++++++++............ ...
+ *++++++++++++++..............
+ *+++....++++................
+ *.......... ...........
+ *
+ *.......... ...........
+ *+++....++++................
+ *++++++++++++++..............
+ *++++++++++++++++............ ...
+ *++++++++++++++++++.................
+ **+++++++++++++++++++................
+ **+++++++++++++++++++++..............
+ ***++++++++++++++++++++++............
+ ***++++++++++++++++++++++++......... ...... ...........
+ ****++++++++++++++++++++++++++...... .........................
+ *****++++++++++++++++++++++++++++...............................
+ *****++++++++++++++++++++++++++++++++............................
+ ******+++++++++++++++++++++++++++++++++++...........................
+ *******+++++++++++++++++++++++++++++++++++++++.......................
+ ********+++++++++++++++++++++++++++++++++++++++++++..................
+ Evaluated to 0.000000
+ ready> mandel(-0.9, -1.4, 0.02, 0.03);
+ *******************************************************************************
+ *******************************************************************************
+ *******************************************************************************
+ **********+++++++++++++++++++++************************************************
+ *+++++++++++++++++++++++++++++++++++++++***************************************
+ +++++++++++++++++++++++++++++++++++++++++++++**********************************
+ ++++++++++++++++++++++++++++++++++++++++++++++++++*****************************
+ ++++++++++++++++++++++++++++++++++++++++++++++++++++++*************************
+ +++++++++++++++++++++++++++++++++++++++++++++++++++++++++**********************
+ +++++++++++++++++++++++++++++++++.........++++++++++++++++++*******************
+ +++++++++++++++++++++++++++++++.... ......+++++++++++++++++++****************
+ +++++++++++++++++++++++++++++....... ........+++++++++++++++++++**************
+ ++++++++++++++++++++++++++++........ ........++++++++++++++++++++************
+ +++++++++++++++++++++++++++......... .. ...+++++++++++++++++++++**********
+ ++++++++++++++++++++++++++........... ....++++++++++++++++++++++********
+ ++++++++++++++++++++++++............. .......++++++++++++++++++++++******
+ +++++++++++++++++++++++............. ........+++++++++++++++++++++++****
+ ++++++++++++++++++++++........... ..........++++++++++++++++++++++***
+ ++++++++++++++++++++........... .........++++++++++++++++++++++*
+ ++++++++++++++++++............ ...........++++++++++++++++++++
+ ++++++++++++++++............... .............++++++++++++++++++
+ ++++++++++++++................. ...............++++++++++++++++
+ ++++++++++++.................. .................++++++++++++++
+ +++++++++.................. .................+++++++++++++
+ ++++++........ . ......... ..++++++++++++
+ ++............ ...... ....++++++++++
+ .............. ...++++++++++
+ .............. ....+++++++++
+ .............. .....++++++++
+ ............. ......++++++++
+ ........... .......++++++++
+ ......... ........+++++++
+ ......... ........+++++++
+ ......... ....+++++++
+ ........ ...+++++++
+ ....... ...+++++++
+ ....+++++++
+ .....+++++++
+ ....+++++++
+ ....+++++++
+ ....+++++++
+ Evaluated to 0.000000
+ ready> ^D
+
+At this point, you may be starting to realize that Kaleidoscope is a
+real and powerful language. It may not be self-similar :), but it can be
+used to plot things that are!
+
+With this, we conclude the "adding user-defined operators" chapter of
+the tutorial. We have successfully augmented our language, adding the
+ability to extend the language in the library, and we have shown how
+this can be used to build a simple but interesting end-user application
+in Kaleidoscope. At this point, Kaleidoscope can build a variety of
+applications that are functional and can call functions with
+side-effects, but it can't actually define and mutate a variable itself.
+
+Strikingly, variable mutation is an important feature of some languages,
+and it is not at all obvious how to `add support for mutable
+variables <OCamlLangImpl7.html>`_ without having to add an "SSA
+construction" phase to your front-end. In the next chapter, we will
+describe how you can add variable mutation without building SSA in your
+front-end.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+the if/then/else and for expressions.. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+ <*.{byte,native}>: g++, use_llvm, use_llvm_analysis
+ <*.{byte,native}>: use_llvm_executionengine, use_llvm_target
+ <*.{byte,native}>: use_llvm_scalar_opts, use_bindings
+
+myocamlbuild.ml:
+ .. code-block:: ocaml
+
+ open Ocamlbuild_plugin;;
+
+ ocaml_lib ~extern:true "llvm";;
+ ocaml_lib ~extern:true "llvm_analysis";;
+ ocaml_lib ~extern:true "llvm_executionengine";;
+ ocaml_lib ~extern:true "llvm_target";;
+ ocaml_lib ~extern:true "llvm_scalar_opts";;
+
+ flag ["link"; "ocaml"; "g++"] (S[A"-cc"; A"g++"; A"-cclib"; A"-rdynamic"]);;
+ dep ["link"; "ocaml"; "use_bindings"] ["bindings.o"];;
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+ (* control *)
+ | If | Then | Else
+ | For | In
+
+ (* operators *)
+ | Binary | Unary
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | "if" -> [< 'Token.If; stream >]
+ | "then" -> [< 'Token.Then; stream >]
+ | "else" -> [< 'Token.Else; stream >]
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | "binary" -> [< 'Token.Binary; stream >]
+ | "unary" -> [< 'Token.Unary; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a unary operator. *)
+ | Unary of char * expr
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* variant for if/then/else. *)
+ | If of expr * expr * expr
+
+ (* variant for for/in. *)
+ | For of string * expr * expr * expr option * expr
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto =
+ | Prototype of string * string array
+ | BinOpPrototype of string * string array * int
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr
+ * ::= ifexpr
+ * ::= forexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ (* ifexpr ::= 'if' expr 'then' expr 'else' expr *)
+ | [< 'Token.If; c=parse_expr;
+ 'Token.Then ?? "expected 'then'"; t=parse_expr;
+ 'Token.Else ?? "expected 'else'"; e=parse_expr >] ->
+ Ast.If (c, t, e)
+
+ (* forexpr
+ ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression *)
+ | [< 'Token.For;
+ 'Token.Ident id ?? "expected identifier after for";
+ 'Token.Kwd '=' ?? "expected '=' after for";
+ stream >] ->
+ begin parser
+ | [<
+ start=parse_expr;
+ 'Token.Kwd ',' ?? "expected ',' after for";
+ end_=parse_expr;
+ stream >] ->
+ let step =
+ begin parser
+ | [< 'Token.Kwd ','; step=parse_expr >] -> Some step
+ | [< >] -> None
+ end stream
+ in
+ begin parser
+ | [< 'Token.In; body=parse_expr >] ->
+ Ast.For (id, start, end_, step, body)
+ | [< >] ->
+ raise (Stream.Error "expected 'in' after for")
+ end stream
+ | [< >] ->
+ raise (Stream.Error "expected '=' after for")
+ end stream
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* unary
+ * ::= primary
+ * ::= '!' unary *)
+ and parse_unary = parser
+ (* If this is a unary operator, read it. *)
+ | [< 'Token.Kwd op when op != '(' && op != ')'; operand=parse_expr >] ->
+ Ast.Unary (op, operand)
+
+ (* If the current token is not an operator, it must be a primary expr. *)
+ | [< stream >] -> parse_primary stream
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the unary expression after the binary operator. *)
+ let rhs = parse_unary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_unary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')'
+ * ::= binary LETTER number? (id, id)
+ * ::= unary LETTER number? (id) *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+ let parse_operator = parser
+ | [< 'Token.Unary >] -> "unary", 1
+ | [< 'Token.Binary >] -> "binary", 2
+ in
+ let parse_binary_precedence = parser
+ | [< 'Token.Number n >] -> int_of_float n
+ | [< >] -> 30
+ in
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+ | [< (prefix, kind)=parse_operator;
+ 'Token.Kwd op ?? "expected an operator";
+ (* Read the precedence if present. *)
+ binary_precedence=parse_binary_precedence;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ let name = prefix ^ (String.make 1 op) in
+ let args = Array.of_list (List.rev args) in
+
+ (* Verify right number of arguments for operator. *)
+ if Array.length args != kind
+ then raise (Stream.Error "invalid number of operands for operator")
+ else
+ if kind == 1 then
+ Ast.Prototype (name, args)
+ else
+ Ast.BinOpPrototype (name, args, binary_precedence)
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+codegen.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Code Generation
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+ let rec codegen_expr = function
+ | Ast.Number n -> const_float double_type n
+ | Ast.Variable name ->
+ (try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name"))
+ | Ast.Unary (op, operand) ->
+ let operand = codegen_expr operand in
+ let callee = "unary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown unary operator")
+ in
+ build_call callee [|operand|] "unop" builder
+ | Ast.Binary (op, lhs, rhs) ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ ->
+ (* If it wasn't a builtin binary operator, it must be a user defined
+ * one. Emit a call to it. *)
+ let callee = "binary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "binary operator not found!")
+ in
+ build_call callee [|lhs_val; rhs_val|] "binop" builder
+ end
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+ | Ast.If (cond, then_, else_) ->
+ let cond = codegen_expr cond in
+
+ (* Convert condition to a bool by comparing equal to 0.0 *)
+ let zero = const_float double_type 0.0 in
+ let cond_val = build_fcmp Fcmp.One cond zero "ifcond" builder in
+
+ (* Grab the first block so that we might later add the conditional branch
+ * to it at the end of the function. *)
+ let start_bb = insertion_block builder in
+ let the_function = block_parent start_bb in
+
+ let then_bb = append_block context "then" the_function in
+
+ (* Emit 'then' value. *)
+ position_at_end then_bb builder;
+ let then_val = codegen_expr then_ in
+
+ (* Codegen of 'then' can change the current block, update then_bb for the
+ * phi. We create a new name because one is used for the phi node, and the
+ * other is used for the conditional branch. *)
+ let new_then_bb = insertion_block builder in
+
+ (* Emit 'else' value. *)
+ let else_bb = append_block context "else" the_function in
+ position_at_end else_bb builder;
+ let else_val = codegen_expr else_ in
+
+ (* Codegen of 'else' can change the current block, update else_bb for the
+ * phi. *)
+ let new_else_bb = insertion_block builder in
+
+ (* Emit merge block. *)
+ let merge_bb = append_block context "ifcont" the_function in
+ position_at_end merge_bb builder;
+ let incoming = [(then_val, new_then_bb); (else_val, new_else_bb)] in
+ let phi = build_phi incoming "iftmp" builder in
+
+ (* Return to the start block to add the conditional branch. *)
+ position_at_end start_bb builder;
+ ignore (build_cond_br cond_val then_bb else_bb builder);
+
+ (* Set a unconditional branch at the end of the 'then' block and the
+ * 'else' block to the 'merge' block. *)
+ position_at_end new_then_bb builder; ignore (build_br merge_bb builder);
+ position_at_end new_else_bb builder; ignore (build_br merge_bb builder);
+
+ (* Finally, set the builder to the end of the merge block. *)
+ position_at_end merge_bb builder;
+
+ phi
+ | Ast.For (var_name, start, end_, step, body) ->
+ (* Emit the start code first, without 'variable' in scope. *)
+ let start_val = codegen_expr start in
+
+ (* Make the new basic block for the loop header, inserting after current
+ * block. *)
+ let preheader_bb = insertion_block builder in
+ let the_function = block_parent preheader_bb in
+ let loop_bb = append_block context "loop" the_function in
+
+ (* Insert an explicit fall through from the current block to the
+ * loop_bb. *)
+ ignore (build_br loop_bb builder);
+
+ (* Start insertion in loop_bb. *)
+ position_at_end loop_bb builder;
+
+ (* Start the PHI node with an entry for start. *)
+ let variable = build_phi [(start_val, preheader_bb)] var_name builder in
+
+ (* Within the loop, the variable is defined equal to the PHI node. If it
+ * shadows an existing variable, we have to restore it, so save it
+ * now. *)
+ let old_val =
+ try Some (Hashtbl.find named_values var_name) with Not_found -> None
+ in
+ Hashtbl.add named_values var_name variable;
+
+ (* Emit the body of the loop. This, like any other expr, can change the
+ * current BB. Note that we ignore the value computed by the body, but
+ * don't allow an error *)
+ ignore (codegen_expr body);
+
+ (* Emit the step value. *)
+ let step_val =
+ match step with
+ | Some step -> codegen_expr step
+ (* If not specified, use 1.0. *)
+ | None -> const_float double_type 1.0
+ in
+
+ let next_var = build_add variable step_val "nextvar" builder in
+
+ (* Compute the end condition. *)
+ let end_cond = codegen_expr end_ in
+
+ (* Convert condition to a bool by comparing equal to 0.0. *)
+ let zero = const_float double_type 0.0 in
+ let end_cond = build_fcmp Fcmp.One end_cond zero "loopcond" builder in
+
+ (* Create the "after loop" block and insert it. *)
+ let loop_end_bb = insertion_block builder in
+ let after_bb = append_block context "afterloop" the_function in
+
+ (* Insert the conditional branch into the end of loop_end_bb. *)
+ ignore (build_cond_br end_cond loop_bb after_bb builder);
+
+ (* Any new code will be inserted in after_bb. *)
+ position_at_end after_bb builder;
+
+ (* Add a new entry to the PHI node for the backedge. *)
+ add_incoming (next_var, loop_end_bb) variable;
+
+ (* Restore the unshadowed variable. *)
+ begin match old_val with
+ | Some old_val -> Hashtbl.add named_values var_name old_val
+ | None -> ()
+ end;
+
+ (* for expr always returns 0.0. *)
+ const_null double_type
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) | Ast.BinOpPrototype (name, args, _) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+ | None -> declare_function name ft the_module
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if block_begin f <> At_end f then
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if element_type (type_of f) <> ft then
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+ let codegen_func the_fpm = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* If this is an operator, install it. *)
+ begin match proto with
+ | Ast.BinOpPrototype (name, args, prec) ->
+ let op = name.[String.length name - 1] in
+ Hashtbl.add Parser.binop_precedence op prec;
+ | _ -> ()
+ end;
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ (* Optimize the function. *)
+ let _ = PassManager.run_function the_function the_fpm in
+
+ the_function
+ with e ->
+ delete_function the_function;
+ raise e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop the_fpm the_execution_engine stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop the_fpm the_execution_engine stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ let e = Parser.parse_definition stream in
+ print_endline "parsed a function definition.";
+ dump_value (Codegen.codegen_func the_fpm e);
+ | Token.Extern ->
+ let e = Parser.parse_extern stream in
+ print_endline "parsed an extern.";
+ dump_value (Codegen.codegen_proto e);
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ let the_function = Codegen.codegen_func the_fpm e in
+ dump_value the_function;
+
+ (* JIT the function, returning a function pointer. *)
+ let result = ExecutionEngine.run_function the_function [||]
+ the_execution_engine in
+
+ print_string "Evaluated to ";
+ print_float (GenericValue.as_float Codegen.double_type result);
+ print_newline ();
+ with Stream.Error s | Codegen.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop the_fpm the_execution_engine stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+ open Llvm_target
+ open Llvm_scalar_opts
+
+ let main () =
+ ignore (initialize_native_target ());
+
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combination the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+ (* Eliminate Common SubExpressions. *)
+ add_gvn the_fpm;
+
+ (* Simplify the control flow graph (deleting unreachable blocks, etc). *)
+ add_cfg_simplification the_fpm;
+
+ ignore (PassManager.initialize the_fpm);
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop the_fpm the_execution_engine stream;
+
+ (* Print out all the generated code. *)
+ dump_module Codegen.the_module
+ ;;
+
+ main ()
+
+bindings.c
+ .. code-block:: c
+
+ #include <stdio.h>
+
+ /* putchard - putchar that takes a double and returns 0. */
+ extern double putchard(double X) {
+ putchar((char)X);
+ return 0;
+ }
+
+ /* printd - printf that takes a double prints it as "%f\n", returning 0. */
+ extern double printd(double X) {
+ printf("%f\n", X);
+ return 0;
+ }
+
+`Next: Extending the language: mutable variables / SSA
+construction <OCamlLangImpl7.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl7.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl7.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl7.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl7.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,1723 @@
+=======================================================
+Kaleidoscope: Extending the Language: Mutable Variables
+=======================================================
+
+.. contents::
+ :local:
+
+Chapter 7 Introduction
+======================
+
+Welcome to Chapter 7 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In chapters 1 through 6, we've built a
+very respectable, albeit simple, `functional programming
+language <http://en.wikipedia.org/wiki/Functional_programming>`_. In our
+journey, we learned some parsing techniques, how to build and represent
+an AST, how to build LLVM IR, and how to optimize the resultant code as
+well as JIT compile it.
+
+While Kaleidoscope is interesting as a functional language, the fact
+that it is functional makes it "too easy" to generate LLVM IR for it. In
+particular, a functional language makes it very easy to build LLVM IR
+directly in `SSA
+form <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+Since LLVM requires that the input code be in SSA form, this is a very
+nice property and it is often unclear to newcomers how to generate code
+for an imperative language with mutable variables.
+
+The short (and happy) summary of this chapter is that there is no need
+for your front-end to build SSA form: LLVM provides highly tuned and
+well tested support for this, though the way it works is a bit
+unexpected for some.
+
+Why is this a hard problem?
+===========================
+
+To understand why mutable variables cause complexities in SSA
+construction, consider this extremely simple C example:
+
+.. code-block:: c
+
+ int G, H;
+ int test(_Bool Condition) {
+ int X;
+ if (Condition)
+ X = G;
+ else
+ X = H;
+ return X;
+ }
+
+In this case, we have the variable "X", whose value depends on the path
+executed in the program. Because there are two different possible values
+for X before the return instruction, a PHI node is inserted to merge the
+two values. The LLVM IR that we want for this example looks like this:
+
+.. code-block:: llvm
+
+ @G = weak global i32 0 ; type of @G is i32*
+ @H = weak global i32 0 ; type of @H is i32*
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ br label %cond_next
+
+ cond_next:
+ %X.2 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+ ret i32 %X.2
+ }
+
+In this example, the loads from the G and H global variables are
+explicit in the LLVM IR, and they live in the then/else branches of the
+if statement (cond\_true/cond\_false). In order to merge the incoming
+values, the X.2 phi node in the cond\_next block selects the right value
+to use based on where control flow is coming from: if control flow comes
+from the cond\_false block, X.2 gets the value of X.1. Alternatively, if
+control flow comes from cond\_true, it gets the value of X.0. The intent
+of this chapter is not to explain the details of SSA form. For more
+information, see one of the many `online
+references <http://en.wikipedia.org/wiki/Static_single_assignment_form>`_.
+
+The question for this article is "who places the phi nodes when lowering
+assignments to mutable variables?". The issue here is that LLVM
+*requires* that its IR be in SSA form: there is no "non-ssa" mode for
+it. However, SSA construction requires non-trivial algorithms and data
+structures, so it is inconvenient and wasteful for every front-end to
+have to reproduce this logic.
+
+Memory in LLVM
+==============
+
+The 'trick' here is that while LLVM does require all register values to
+be in SSA form, it does not require (or permit) memory objects to be in
+SSA form. In the example above, note that the loads from G and H are
+direct accesses to G and H: they are not renamed or versioned. This
+differs from some other compiler systems, which do try to version memory
+objects. In LLVM, instead of encoding dataflow analysis of memory into
+the LLVM IR, it is handled with `Analysis
+Passes <../WritingAnLLVMPass.html>`_ which are computed on demand.
+
+With this in mind, the high-level idea is that we want to make a stack
+variable (which lives in memory, because it is on the stack) for each
+mutable object in a function. To take advantage of this trick, we need
+to talk about how LLVM represents stack variables.
+
+In LLVM, all memory accesses are explicit with load/store instructions,
+and it is carefully designed not to have (or need) an "address-of"
+operator. Notice how the type of the @G/@H global variables is actually
+"i32\*" even though the variable is defined as "i32". What this means is
+that @G defines *space* for an i32 in the global data area, but its
+*name* actually refers to the address for that space. Stack variables
+work the same way, except that instead of being declared with global
+variable definitions, they are declared with the `LLVM alloca
+instruction <../LangRef.html#alloca-instruction>`_:
+
+.. code-block:: llvm
+
+ define i32 @example() {
+ entry:
+ %X = alloca i32 ; type of %X is i32*.
+ ...
+ %tmp = load i32* %X ; load the stack value %X from the stack.
+ %tmp2 = add i32 %tmp, 1 ; increment it
+ store i32 %tmp2, i32* %X ; store it back
+ ...
+
+This code shows an example of how you can declare and manipulate a stack
+variable in the LLVM IR. Stack memory allocated with the alloca
+instruction is fully general: you can pass the address of the stack slot
+to functions, you can store it in other variables, etc. In our example
+above, we could rewrite the example to use the alloca technique to avoid
+using a PHI node:
+
+.. code-block:: llvm
+
+ @G = weak global i32 0 ; type of @G is i32*
+ @H = weak global i32 0 ; type of @H is i32*
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ %X = alloca i32 ; type of %X is i32*.
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ store i32 %X.0, i32* %X ; Update X
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ store i32 %X.1, i32* %X ; Update X
+ br label %cond_next
+
+ cond_next:
+ %X.2 = load i32* %X ; Read X
+ ret i32 %X.2
+ }
+
+With this, we have discovered a way to handle arbitrary mutable
+variables without the need to create Phi nodes at all:
+
+#. Each mutable variable becomes a stack allocation.
+#. Each read of the variable becomes a load from the stack.
+#. Each update of the variable becomes a store to the stack.
+#. Taking the address of a variable just uses the stack address
+ directly.
+
+While this solution has solved our immediate problem, it introduced
+another one: we have now apparently introduced a lot of stack traffic
+for very simple and common operations, a major performance problem.
+Fortunately for us, the LLVM optimizer has a highly-tuned optimization
+pass named "mem2reg" that handles this case, promoting allocas like this
+into SSA registers, inserting Phi nodes as appropriate. If you run this
+example through the pass, for example, you'll get:
+
+.. code-block:: bash
+
+ $ llvm-as < example.ll | opt -mem2reg | llvm-dis
+ @G = weak global i32 0
+ @H = weak global i32 0
+
+ define i32 @test(i1 %Condition) {
+ entry:
+ br i1 %Condition, label %cond_true, label %cond_false
+
+ cond_true:
+ %X.0 = load i32* @G
+ br label %cond_next
+
+ cond_false:
+ %X.1 = load i32* @H
+ br label %cond_next
+
+ cond_next:
+ %X.01 = phi i32 [ %X.1, %cond_false ], [ %X.0, %cond_true ]
+ ret i32 %X.01
+ }
+
+The mem2reg pass implements the standard "iterated dominance frontier"
+algorithm for constructing SSA form and has a number of optimizations
+that speed up (very common) degenerate cases. The mem2reg optimization
+pass is the answer to dealing with mutable variables, and we highly
+recommend that you depend on it. Note that mem2reg only works on
+variables in certain circumstances:
+
+#. mem2reg is alloca-driven: it looks for allocas and if it can handle
+ them, it promotes them. It does not apply to global variables or heap
+ allocations.
+#. mem2reg only looks for alloca instructions in the entry block of the
+ function. Being in the entry block guarantees that the alloca is only
+ executed once, which makes analysis simpler.
+#. mem2reg only promotes allocas whose uses are direct loads and stores.
+ If the address of the stack object is passed to a function, or if any
+ funny pointer arithmetic is involved, the alloca will not be
+ promoted.
+#. mem2reg only works on allocas of `first
+ class <../LangRef.html#first-class-types>`_ values (such as pointers,
+ scalars and vectors), and only if the array size of the allocation is
+ 1 (or missing in the .ll file). mem2reg is not capable of promoting
+ structs or arrays to registers. Note that the "sroa" pass is
+ more powerful and can promote structs, "unions", and arrays in many
+ cases.
+
+All of these properties are easy to satisfy for most imperative
+languages, and we'll illustrate it below with Kaleidoscope. The final
+question you may be asking is: should I bother with this nonsense for my
+front-end? Wouldn't it be better if I just did SSA construction
+directly, avoiding use of the mem2reg optimization pass? In short, we
+strongly recommend that you use this technique for building SSA form,
+unless there is an extremely good reason not to. Using this technique
+is:
+
+- Proven and well tested: clang uses this technique
+ for local mutable variables. As such, the most common clients of LLVM
+ are using this to handle a bulk of their variables. You can be sure
+ that bugs are found fast and fixed early.
+- Extremely Fast: mem2reg has a number of special cases that make it
+ fast in common cases as well as fully general. For example, it has
+ fast-paths for variables that are only used in a single block,
+ variables that only have one assignment point, good heuristics to
+ avoid insertion of unneeded phi nodes, etc.
+- Needed for debug info generation: `Debug information in
+ LLVM <../SourceLevelDebugging.html>`_ relies on having the address of
+ the variable exposed so that debug info can be attached to it. This
+ technique dovetails very naturally with this style of debug info.
+
+If nothing else, this makes it much easier to get your front-end up and
+running, and is very simple to implement. Lets extend Kaleidoscope with
+mutable variables now!
+
+Mutable Variables in Kaleidoscope
+=================================
+
+Now that we know the sort of problem we want to tackle, lets see what
+this looks like in the context of our little Kaleidoscope language.
+We're going to add two features:
+
+#. The ability to mutate variables with the '=' operator.
+#. The ability to define new variables.
+
+While the first item is really what this is about, we only have
+variables for incoming arguments as well as for induction variables, and
+redefining those only goes so far :). Also, the ability to define new
+variables is a useful thing regardless of whether you will be mutating
+them. Here's a motivating example that shows how we could use these:
+
+::
+
+ # Define ':' for sequencing: as a low-precedence operator that ignores operands
+ # and just returns the RHS.
+ def binary : 1 (x y) y;
+
+ # Recursive fib, we could do this before.
+ def fib(x)
+ if (x < 3) then
+ 1
+ else
+ fib(x-1)+fib(x-2);
+
+ # Iterative fib.
+ def fibi(x)
+ var a = 1, b = 1, c in
+ (for i = 3, i < x in
+ c = a + b :
+ a = b :
+ b = c) :
+ b;
+
+ # Call it.
+ fibi(10);
+
+In order to mutate variables, we have to change our existing variables
+to use the "alloca trick". Once we have that, we'll add our new
+operator, then extend Kaleidoscope to support new variable definitions.
+
+Adjusting Existing Variables for Mutation
+=========================================
+
+The symbol table in Kaleidoscope is managed at code generation time by
+the '``named_values``' map. This map currently keeps track of the LLVM
+"Value\*" that holds the double value for the named variable. In order
+to support mutation, we need to change this slightly, so that it
+``named_values`` holds the *memory location* of the variable in
+question. Note that this change is a refactoring: it changes the
+structure of the code, but does not (by itself) change the behavior of
+the compiler. All of these changes are isolated in the Kaleidoscope code
+generator.
+
+At this point in Kaleidoscope's development, it only supports variables
+for two things: incoming arguments to functions and the induction
+variable of 'for' loops. For consistency, we'll allow mutation of these
+variables in addition to other user-defined variables. This means that
+these will both need memory locations.
+
+To start our transformation of Kaleidoscope, we'll change the
+``named_values`` map so that it maps to AllocaInst\* instead of Value\*.
+Once we do this, the C++ compiler will tell us what parts of the code we
+need to update:
+
+**Note:** the ocaml bindings currently model both ``Value*``'s and
+``AllocInst*``'s as ``Llvm.llvalue``'s, but this may change in the future
+to be more type safe.
+
+.. code-block:: ocaml
+
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+
+Also, since we will need to create these alloca's, we'll use a helper
+function that ensures that the allocas are created in the entry block of
+the function:
+
+.. code-block:: ocaml
+
+ (* Create an alloca instruction in the entry block of the function. This
+ * is used for mutable variables etc. *)
+ let create_entry_block_alloca the_function var_name =
+ let builder = builder_at (instr_begin (entry_block the_function)) in
+ build_alloca double_type var_name builder
+
+This funny looking code creates an ``Llvm.llbuilder`` object that is
+pointing at the first instruction of the entry block. It then creates an
+alloca with the expected name and returns it. Because all values in
+Kaleidoscope are doubles, there is no need to pass in a type to use.
+
+With this in place, the first functionality change we want to make is to
+variable references. In our new scheme, variables live on the stack, so
+code generating a reference to them actually needs to produce a load
+from the stack slot:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ ...
+ | Ast.Variable name ->
+ let v = try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name")
+ in
+ (* Load the value. *)
+ build_load v name builder
+
+As you can see, this is pretty straightforward. Now we need to update
+the things that define the variables to set up the alloca. We'll start
+with ``codegen_expr Ast.For ...`` (see the `full code listing <#id1>`_
+for the unabridged code):
+
+.. code-block:: ocaml
+
+ | Ast.For (var_name, start, end_, step, body) ->
+ let the_function = block_parent (insertion_block builder) in
+
+ (* Create an alloca for the variable in the entry block. *)
+ let alloca = create_entry_block_alloca the_function var_name in
+
+ (* Emit the start code first, without 'variable' in scope. *)
+ let start_val = codegen_expr start in
+
+ (* Store the value into the alloca. *)
+ ignore(build_store start_val alloca builder);
+
+ ...
+
+ (* Within the loop, the variable is defined equal to the PHI node. If it
+ * shadows an existing variable, we have to restore it, so save it
+ * now. *)
+ let old_val =
+ try Some (Hashtbl.find named_values var_name) with Not_found -> None
+ in
+ Hashtbl.add named_values var_name alloca;
+
+ ...
+
+ (* Compute the end condition. *)
+ let end_cond = codegen_expr end_ in
+
+ (* Reload, increment, and restore the alloca. This handles the case where
+ * the body of the loop mutates the variable. *)
+ let cur_var = build_load alloca var_name builder in
+ let next_var = build_add cur_var step_val "nextvar" builder in
+ ignore(build_store next_var alloca builder);
+ ...
+
+This code is virtually identical to the code `before we allowed mutable
+variables <OCamlLangImpl5.html#code-generation-for-the-for-loop>`_. The big difference is that
+we no longer have to construct a PHI node, and we use load/store to
+access the variable as needed.
+
+To support mutable argument variables, we need to also make allocas for
+them. The code for this is also pretty simple:
+
+.. code-block:: ocaml
+
+ (* Create an alloca for each argument and register the argument in the symbol
+ * table so that references to it will succeed. *)
+ let create_argument_allocas the_function proto =
+ let args = match proto with
+ | Ast.Prototype (_, args) | Ast.BinOpPrototype (_, args, _) -> args
+ in
+ Array.iteri (fun i ai ->
+ let var_name = args.(i) in
+ (* Create an alloca for this variable. *)
+ let alloca = create_entry_block_alloca the_function var_name in
+
+ (* Store the initial value into the alloca. *)
+ ignore(build_store ai alloca builder);
+
+ (* Add arguments to variable symbol table. *)
+ Hashtbl.add named_values var_name alloca;
+ ) (params the_function)
+
+For each argument, we make an alloca, store the input value to the
+function into the alloca, and register the alloca as the memory location
+for the argument. This method gets invoked by ``Codegen.codegen_func``
+right after it sets up the entry block for the function.
+
+The final missing piece is adding the mem2reg pass, which allows us to
+get good codegen once again:
+
+.. code-block:: ocaml
+
+ let main () =
+ ...
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Promote allocas to registers. *)
+ add_memory_to_register_promotion the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combining the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+It is interesting to see what the code looks like before and after the
+mem2reg optimization runs. For example, this is the before/after code
+for our recursive fib function. Before the optimization:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %x1 = alloca double
+ store double %x, double* %x1
+ %x2 = load double* %x1
+ %cmptmp = fcmp ult double %x2, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then: ; preds = %entry
+ br label %ifcont
+
+ else: ; preds = %entry
+ %x3 = load double* %x1
+ %subtmp = fsub double %x3, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %x4 = load double* %x1
+ %subtmp5 = fsub double %x4, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+ ret double %iftmp
+ }
+
+Here there is only one variable (x, the input argument) but you can
+still see the extremely simple-minded code generation strategy we are
+using. In the entry block, an alloca is created, and the initial input
+value is stored into it. Each reference to the variable does a reload
+from the stack. Also, note that we didn't modify the if/then/else
+expression, so it still inserts a PHI node. While we could make an
+alloca for it, it is actually easier to create a PHI node for it, so we
+still just make the PHI.
+
+Here is the code after the mem2reg pass runs:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %cmptmp = fcmp ult double %x, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp one double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %then, label %else
+
+ then:
+ br label %ifcont
+
+ else:
+ %subtmp = fsub double %x, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %subtmp5 = fsub double %x, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ br label %ifcont
+
+ ifcont: ; preds = %else, %then
+ %iftmp = phi double [ 1.000000e+00, %then ], [ %addtmp, %else ]
+ ret double %iftmp
+ }
+
+This is a trivial case for mem2reg, since there are no redefinitions of
+the variable. The point of showing this is to calm your tension about
+inserting such blatent inefficiencies :).
+
+After the rest of the optimizers run, we get:
+
+.. code-block:: llvm
+
+ define double @fib(double %x) {
+ entry:
+ %cmptmp = fcmp ult double %x, 3.000000e+00
+ %booltmp = uitofp i1 %cmptmp to double
+ %ifcond = fcmp ueq double %booltmp, 0.000000e+00
+ br i1 %ifcond, label %else, label %ifcont
+
+ else:
+ %subtmp = fsub double %x, 1.000000e+00
+ %calltmp = call double @fib(double %subtmp)
+ %subtmp5 = fsub double %x, 2.000000e+00
+ %calltmp6 = call double @fib(double %subtmp5)
+ %addtmp = fadd double %calltmp, %calltmp6
+ ret double %addtmp
+
+ ifcont:
+ ret double 1.000000e+00
+ }
+
+Here we see that the simplifycfg pass decided to clone the return
+instruction into the end of the 'else' block. This allowed it to
+eliminate some branches and the PHI node.
+
+Now that all symbol table references are updated to use stack variables,
+we'll add the assignment operator.
+
+New Assignment Operator
+=======================
+
+With our current framework, adding a new assignment operator is really
+simple. We will parse it just like any other binary operator, but handle
+it internally (instead of allowing the user to define it). The first
+step is to set a precedence:
+
+.. code-block:: ocaml
+
+ let main () =
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '=' 2;
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ ...
+
+Now that the parser knows the precedence of the binary operator, it
+takes care of all the parsing and AST generation. We just need to
+implement codegen for the assignment operator. This looks like:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ begin match op with
+ | '=' ->
+ (* Special case '=' because we don't want to emit the LHS as an
+ * expression. *)
+ let name =
+ match lhs with
+ | Ast.Variable name -> name
+ | _ -> raise (Error "destination of '=' must be a variable")
+ in
+
+Unlike the rest of the binary operators, our assignment operator doesn't
+follow the "emit LHS, emit RHS, do computation" model. As such, it is
+handled as a special case before the other binary operators are handled.
+The other strange thing is that it requires the LHS to be a variable. It
+is invalid to have "(x+1) = expr" - only things like "x = expr" are
+allowed.
+
+.. code-block:: ocaml
+
+ (* Codegen the rhs. *)
+ let val_ = codegen_expr rhs in
+
+ (* Lookup the name. *)
+ let variable = try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name")
+ in
+ ignore(build_store val_ variable builder);
+ val_
+ | _ ->
+ ...
+
+Once we have the variable, codegen'ing the assignment is
+straightforward: we emit the RHS of the assignment, create a store, and
+return the computed value. Returning a value allows for chained
+assignments like "X = (Y = Z)".
+
+Now that we have an assignment operator, we can mutate loop variables
+and arguments. For example, we can now run code like this:
+
+::
+
+ # Function to print a double.
+ extern printd(x);
+
+ # Define ':' for sequencing: as a low-precedence operator that ignores operands
+ # and just returns the RHS.
+ def binary : 1 (x y) y;
+
+ def test(x)
+ printd(x) :
+ x = 4 :
+ printd(x);
+
+ test(123);
+
+When run, this example prints "123" and then "4", showing that we did
+actually mutate the value! Okay, we have now officially implemented our
+goal: getting this to work requires SSA construction in the general
+case. However, to be really useful, we want the ability to define our
+own local variables, lets add this next!
+
+User-defined Local Variables
+============================
+
+Adding var/in is just like any other other extensions we made to
+Kaleidoscope: we extend the lexer, the parser, the AST and the code
+generator. The first step for adding our new 'var/in' construct is to
+extend the lexer. As before, this is pretty trivial, the code looks like
+this:
+
+.. code-block:: ocaml
+
+ type token =
+ ...
+ (* var definition *)
+ | Var
+
+ ...
+
+ and lex_ident buffer = parser
+ ...
+ | "in" -> [< 'Token.In; stream >]
+ | "binary" -> [< 'Token.Binary; stream >]
+ | "unary" -> [< 'Token.Unary; stream >]
+ | "var" -> [< 'Token.Var; stream >]
+ ...
+
+The next step is to define the AST node that we will construct. For
+var/in, it looks like this:
+
+.. code-block:: ocaml
+
+ type expr =
+ ...
+ (* variant for var/in. *)
+ | Var of (string * expr option) array * expr
+ ...
+
+var/in allows a list of names to be defined all at once, and each name
+can optionally have an initializer value. As such, we capture this
+information in the VarNames vector. Also, var/in has a body, this body
+is allowed to access the variables defined by the var/in.
+
+With this in place, we can define the parser pieces. The first thing we
+do is add it as a primary expression:
+
+.. code-block:: ocaml
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr
+ * ::= ifexpr
+ * ::= forexpr
+ * ::= varexpr *)
+ let rec parse_primary = parser
+ ...
+ (* varexpr
+ * ::= 'var' identifier ('=' expression?
+ * (',' identifier ('=' expression)?)* 'in' expression *)
+ | [< 'Token.Var;
+ (* At least one variable name is required. *)
+ 'Token.Ident id ?? "expected identifier after var";
+ init=parse_var_init;
+ var_names=parse_var_names [(id, init)];
+ (* At this point, we have to have 'in'. *)
+ 'Token.In ?? "expected 'in' keyword after 'var'";
+ body=parse_expr >] ->
+ Ast.Var (Array.of_list (List.rev var_names), body)
+
+ ...
+
+ and parse_var_init = parser
+ (* read in the optional initializer. *)
+ | [< 'Token.Kwd '='; e=parse_expr >] -> Some e
+ | [< >] -> None
+
+ and parse_var_names accumulator = parser
+ | [< 'Token.Kwd ',';
+ 'Token.Ident id ?? "expected identifier list after var";
+ init=parse_var_init;
+ e=parse_var_names ((id, init) :: accumulator) >] -> e
+ | [< >] -> accumulator
+
+Now that we can parse and represent the code, we need to support
+emission of LLVM IR for it. This code starts out with:
+
+.. code-block:: ocaml
+
+ let rec codegen_expr = function
+ ...
+ | Ast.Var (var_names, body)
+ let old_bindings = ref [] in
+
+ let the_function = block_parent (insertion_block builder) in
+
+ (* Register all variables and emit their initializer. *)
+ Array.iter (fun (var_name, init) ->
+
+Basically it loops over all the variables, installing them one at a
+time. For each variable we put into the symbol table, we remember the
+previous value that we replace in OldBindings.
+
+.. code-block:: ocaml
+
+ (* Emit the initializer before adding the variable to scope, this
+ * prevents the initializer from referencing the variable itself, and
+ * permits stuff like this:
+ * var a = 1 in
+ * var a = a in ... # refers to outer 'a'. *)
+ let init_val =
+ match init with
+ | Some init -> codegen_expr init
+ (* If not specified, use 0.0. *)
+ | None -> const_float double_type 0.0
+ in
+
+ let alloca = create_entry_block_alloca the_function var_name in
+ ignore(build_store init_val alloca builder);
+
+ (* Remember the old variable binding so that we can restore the binding
+ * when we unrecurse. *)
+
+ begin
+ try
+ let old_value = Hashtbl.find named_values var_name in
+ old_bindings := (var_name, old_value) :: !old_bindings;
+ with Not_found > ()
+ end;
+
+ (* Remember this binding. *)
+ Hashtbl.add named_values var_name alloca;
+ ) var_names;
+
+There are more comments here than code. The basic idea is that we emit
+the initializer, create the alloca, then update the symbol table to
+point to it. Once all the variables are installed in the symbol table,
+we evaluate the body of the var/in expression:
+
+.. code-block:: ocaml
+
+ (* Codegen the body, now that all vars are in scope. *)
+ let body_val = codegen_expr body in
+
+Finally, before returning, we restore the previous variable bindings:
+
+.. code-block:: ocaml
+
+ (* Pop all our variables from scope. *)
+ List.iter (fun (var_name, old_value) ->
+ Hashtbl.add named_values var_name old_value
+ ) !old_bindings;
+
+ (* Return the body computation. *)
+ body_val
+
+The end result of all of this is that we get properly scoped variable
+definitions, and we even (trivially) allow mutation of them :).
+
+With this, we completed what we set out to do. Our nice iterative fib
+example from the intro compiles and runs just fine. The mem2reg pass
+optimizes all of our stack variables into SSA registers, inserting PHI
+nodes where needed, and our front-end remains simple: no "iterated
+dominance frontier" computation anywhere in sight.
+
+Full Code Listing
+=================
+
+Here is the complete code listing for our running example, enhanced with
+mutable variables and var/in support. To build this example, use:
+
+.. code-block:: bash
+
+ # Compile
+ ocamlbuild toy.byte
+ # Run
+ ./toy.byte
+
+Here is the code:
+
+\_tags:
+ ::
+
+ <{lexer,parser}.ml>: use_camlp4, pp(camlp4of)
+ <*.{byte,native}>: g++, use_llvm, use_llvm_analysis
+ <*.{byte,native}>: use_llvm_executionengine, use_llvm_target
+ <*.{byte,native}>: use_llvm_scalar_opts, use_bindings
+
+myocamlbuild.ml:
+ .. code-block:: ocaml
+
+ open Ocamlbuild_plugin;;
+
+ ocaml_lib ~extern:true "llvm";;
+ ocaml_lib ~extern:true "llvm_analysis";;
+ ocaml_lib ~extern:true "llvm_executionengine";;
+ ocaml_lib ~extern:true "llvm_target";;
+ ocaml_lib ~extern:true "llvm_scalar_opts";;
+
+ flag ["link"; "ocaml"; "g++"] (S[A"-cc"; A"g++"; A"-cclib"; A"-rdynamic"]);;
+ dep ["link"; "ocaml"; "use_bindings"] ["bindings.o"];;
+
+token.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer Tokens
+ *===----------------------------------------------------------------------===*)
+
+ (* The lexer returns these 'Kwd' if it is an unknown character, otherwise one of
+ * these others for known things. *)
+ type token =
+ (* commands *)
+ | Def | Extern
+
+ (* primary *)
+ | Ident of string | Number of float
+
+ (* unknown *)
+ | Kwd of char
+
+ (* control *)
+ | If | Then | Else
+ | For | In
+
+ (* operators *)
+ | Binary | Unary
+
+ (* var definition *)
+ | Var
+
+lexer.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Lexer
+ *===----------------------------------------------------------------------===*)
+
+ let rec lex = parser
+ (* Skip any whitespace. *)
+ | [< ' (' ' | '\n' | '\r' | '\t'); stream >] -> lex stream
+
+ (* identifier: [a-zA-Z][a-zA-Z0-9] *)
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+
+ (* number: [0-9.]+ *)
+ | [< ' ('0' .. '9' as c); stream >] ->
+ let buffer = Buffer.create 1 in
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+
+ (* Comment until end of line. *)
+ | [< ' ('#'); stream >] ->
+ lex_comment stream
+
+ (* Otherwise, just return the character as its ascii value. *)
+ | [< 'c; stream >] ->
+ [< 'Token.Kwd c; lex stream >]
+
+ (* end of stream. *)
+ | [< >] -> [< >]
+
+ and lex_number buffer = parser
+ | [< ' ('0' .. '9' | '.' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_number buffer stream
+ | [< stream=lex >] ->
+ [< 'Token.Number (float_of_string (Buffer.contents buffer)); stream >]
+
+ and lex_ident buffer = parser
+ | [< ' ('A' .. 'Z' | 'a' .. 'z' | '0' .. '9' as c); stream >] ->
+ Buffer.add_char buffer c;
+ lex_ident buffer stream
+ | [< stream=lex >] ->
+ match Buffer.contents buffer with
+ | "def" -> [< 'Token.Def; stream >]
+ | "extern" -> [< 'Token.Extern; stream >]
+ | "if" -> [< 'Token.If; stream >]
+ | "then" -> [< 'Token.Then; stream >]
+ | "else" -> [< 'Token.Else; stream >]
+ | "for" -> [< 'Token.For; stream >]
+ | "in" -> [< 'Token.In; stream >]
+ | "binary" -> [< 'Token.Binary; stream >]
+ | "unary" -> [< 'Token.Unary; stream >]
+ | "var" -> [< 'Token.Var; stream >]
+ | id -> [< 'Token.Ident id; stream >]
+
+ and lex_comment = parser
+ | [< ' ('\n'); stream=lex >] -> stream
+ | [< 'c; e=lex_comment >] -> e
+ | [< >] -> [< >]
+
+ast.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Abstract Syntax Tree (aka Parse Tree)
+ *===----------------------------------------------------------------------===*)
+
+ (* expr - Base type for all expression nodes. *)
+ type expr =
+ (* variant for numeric literals like "1.0". *)
+ | Number of float
+
+ (* variant for referencing a variable, like "a". *)
+ | Variable of string
+
+ (* variant for a unary operator. *)
+ | Unary of char * expr
+
+ (* variant for a binary operator. *)
+ | Binary of char * expr * expr
+
+ (* variant for function calls. *)
+ | Call of string * expr array
+
+ (* variant for if/then/else. *)
+ | If of expr * expr * expr
+
+ (* variant for for/in. *)
+ | For of string * expr * expr * expr option * expr
+
+ (* variant for var/in. *)
+ | Var of (string * expr option) array * expr
+
+ (* proto - This type represents the "prototype" for a function, which captures
+ * its name, and its argument names (thus implicitly the number of arguments the
+ * function takes). *)
+ type proto =
+ | Prototype of string * string array
+ | BinOpPrototype of string * string array * int
+
+ (* func - This type represents a function definition itself. *)
+ type func = Function of proto * expr
+
+parser.ml:
+ .. code-block:: ocaml
+
+ (*===---------------------------------------------------------------------===
+ * Parser
+ *===---------------------------------------------------------------------===*)
+
+ (* binop_precedence - This holds the precedence for each binary operator that is
+ * defined *)
+ let binop_precedence:(char, int) Hashtbl.t = Hashtbl.create 10
+
+ (* precedence - Get the precedence of the pending binary operator token. *)
+ let precedence c = try Hashtbl.find binop_precedence c with Not_found -> -1
+
+ (* primary
+ * ::= identifier
+ * ::= numberexpr
+ * ::= parenexpr
+ * ::= ifexpr
+ * ::= forexpr
+ * ::= varexpr *)
+ let rec parse_primary = parser
+ (* numberexpr ::= number *)
+ | [< 'Token.Number n >] -> Ast.Number n
+
+ (* parenexpr ::= '(' expression ')' *)
+ | [< 'Token.Kwd '('; e=parse_expr; 'Token.Kwd ')' ?? "expected ')'" >] -> e
+
+ (* identifierexpr
+ * ::= identifier
+ * ::= identifier '(' argumentexpr ')' *)
+ | [< 'Token.Ident id; stream >] ->
+ let rec parse_args accumulator = parser
+ | [< e=parse_expr; stream >] ->
+ begin parser
+ | [< 'Token.Kwd ','; e=parse_args (e :: accumulator) >] -> e
+ | [< >] -> e :: accumulator
+ end stream
+ | [< >] -> accumulator
+ in
+ let rec parse_ident id = parser
+ (* Call. *)
+ | [< 'Token.Kwd '(';
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')'">] ->
+ Ast.Call (id, Array.of_list (List.rev args))
+
+ (* Simple variable ref. *)
+ | [< >] -> Ast.Variable id
+ in
+ parse_ident id stream
+
+ (* ifexpr ::= 'if' expr 'then' expr 'else' expr *)
+ | [< 'Token.If; c=parse_expr;
+ 'Token.Then ?? "expected 'then'"; t=parse_expr;
+ 'Token.Else ?? "expected 'else'"; e=parse_expr >] ->
+ Ast.If (c, t, e)
+
+ (* forexpr
+ ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression *)
+ | [< 'Token.For;
+ 'Token.Ident id ?? "expected identifier after for";
+ 'Token.Kwd '=' ?? "expected '=' after for";
+ stream >] ->
+ begin parser
+ | [<
+ start=parse_expr;
+ 'Token.Kwd ',' ?? "expected ',' after for";
+ end_=parse_expr;
+ stream >] ->
+ let step =
+ begin parser
+ | [< 'Token.Kwd ','; step=parse_expr >] -> Some step
+ | [< >] -> None
+ end stream
+ in
+ begin parser
+ | [< 'Token.In; body=parse_expr >] ->
+ Ast.For (id, start, end_, step, body)
+ | [< >] ->
+ raise (Stream.Error "expected 'in' after for")
+ end stream
+ | [< >] ->
+ raise (Stream.Error "expected '=' after for")
+ end stream
+
+ (* varexpr
+ * ::= 'var' identifier ('=' expression?
+ * (',' identifier ('=' expression)?)* 'in' expression *)
+ | [< 'Token.Var;
+ (* At least one variable name is required. *)
+ 'Token.Ident id ?? "expected identifier after var";
+ init=parse_var_init;
+ var_names=parse_var_names [(id, init)];
+ (* At this point, we have to have 'in'. *)
+ 'Token.In ?? "expected 'in' keyword after 'var'";
+ body=parse_expr >] ->
+ Ast.Var (Array.of_list (List.rev var_names), body)
+
+ | [< >] -> raise (Stream.Error "unknown token when expecting an expression.")
+
+ (* unary
+ * ::= primary
+ * ::= '!' unary *)
+ and parse_unary = parser
+ (* If this is a unary operator, read it. *)
+ | [< 'Token.Kwd op when op != '(' && op != ')'; operand=parse_expr >] ->
+ Ast.Unary (op, operand)
+
+ (* If the current token is not an operator, it must be a primary expr. *)
+ | [< stream >] -> parse_primary stream
+
+ (* binoprhs
+ * ::= ('+' primary)* *)
+ and parse_bin_rhs expr_prec lhs stream =
+ match Stream.peek stream with
+ (* If this is a binop, find its precedence. *)
+ | Some (Token.Kwd c) when Hashtbl.mem binop_precedence c ->
+ let token_prec = precedence c in
+
+ (* If this is a binop that binds at least as tightly as the current binop,
+ * consume it, otherwise we are done. *)
+ if token_prec < expr_prec then lhs else begin
+ (* Eat the binop. *)
+ Stream.junk stream;
+
+ (* Parse the primary expression after the binary operator. *)
+ let rhs = parse_unary stream in
+
+ (* Okay, we know this is a binop. *)
+ let rhs =
+ match Stream.peek stream with
+ | Some (Token.Kwd c2) ->
+ (* If BinOp binds less tightly with rhs than the operator after
+ * rhs, let the pending operator take rhs as its lhs. *)
+ let next_prec = precedence c2 in
+ if token_prec < next_prec
+ then parse_bin_rhs (token_prec + 1) rhs stream
+ else rhs
+ | _ -> rhs
+ in
+
+ (* Merge lhs/rhs. *)
+ let lhs = Ast.Binary (c, lhs, rhs) in
+ parse_bin_rhs expr_prec lhs stream
+ end
+ | _ -> lhs
+
+ and parse_var_init = parser
+ (* read in the optional initializer. *)
+ | [< 'Token.Kwd '='; e=parse_expr >] -> Some e
+ | [< >] -> None
+
+ and parse_var_names accumulator = parser
+ | [< 'Token.Kwd ',';
+ 'Token.Ident id ?? "expected identifier list after var";
+ init=parse_var_init;
+ e=parse_var_names ((id, init) :: accumulator) >] -> e
+ | [< >] -> accumulator
+
+ (* expression
+ * ::= primary binoprhs *)
+ and parse_expr = parser
+ | [< lhs=parse_unary; stream >] -> parse_bin_rhs 0 lhs stream
+
+ (* prototype
+ * ::= id '(' id* ')'
+ * ::= binary LETTER number? (id, id)
+ * ::= unary LETTER number? (id) *)
+ let parse_prototype =
+ let rec parse_args accumulator = parser
+ | [< 'Token.Ident id; e=parse_args (id::accumulator) >] -> e
+ | [< >] -> accumulator
+ in
+ let parse_operator = parser
+ | [< 'Token.Unary >] -> "unary", 1
+ | [< 'Token.Binary >] -> "binary", 2
+ in
+ let parse_binary_precedence = parser
+ | [< 'Token.Number n >] -> int_of_float n
+ | [< >] -> 30
+ in
+ parser
+ | [< 'Token.Ident id;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ (* success. *)
+ Ast.Prototype (id, Array.of_list (List.rev args))
+ | [< (prefix, kind)=parse_operator;
+ 'Token.Kwd op ?? "expected an operator";
+ (* Read the precedence if present. *)
+ binary_precedence=parse_binary_precedence;
+ 'Token.Kwd '(' ?? "expected '(' in prototype";
+ args=parse_args [];
+ 'Token.Kwd ')' ?? "expected ')' in prototype" >] ->
+ let name = prefix ^ (String.make 1 op) in
+ let args = Array.of_list (List.rev args) in
+
+ (* Verify right number of arguments for operator. *)
+ if Array.length args != kind
+ then raise (Stream.Error "invalid number of operands for operator")
+ else
+ if kind == 1 then
+ Ast.Prototype (name, args)
+ else
+ Ast.BinOpPrototype (name, args, binary_precedence)
+ | [< >] ->
+ raise (Stream.Error "expected function name in prototype")
+
+ (* definition ::= 'def' prototype expression *)
+ let parse_definition = parser
+ | [< 'Token.Def; p=parse_prototype; e=parse_expr >] ->
+ Ast.Function (p, e)
+
+ (* toplevelexpr ::= expression *)
+ let parse_toplevel = parser
+ | [< e=parse_expr >] ->
+ (* Make an anonymous proto. *)
+ Ast.Function (Ast.Prototype ("", [||]), e)
+
+ (* external ::= 'extern' prototype *)
+ let parse_extern = parser
+ | [< 'Token.Extern; e=parse_prototype >] -> e
+
+codegen.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Code Generation
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+
+ exception Error of string
+
+ let context = global_context ()
+ let the_module = create_module context "my cool jit"
+ let builder = builder context
+ let named_values:(string, llvalue) Hashtbl.t = Hashtbl.create 10
+ let double_type = double_type context
+
+ (* Create an alloca instruction in the entry block of the function. This
+ * is used for mutable variables etc. *)
+ let create_entry_block_alloca the_function var_name =
+ let builder = builder_at context (instr_begin (entry_block the_function)) in
+ build_alloca double_type var_name builder
+
+ let rec codegen_expr = function
+ | Ast.Number n -> const_float double_type n
+ | Ast.Variable name ->
+ let v = try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name")
+ in
+ (* Load the value. *)
+ build_load v name builder
+ | Ast.Unary (op, operand) ->
+ let operand = codegen_expr operand in
+ let callee = "unary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown unary operator")
+ in
+ build_call callee [|operand|] "unop" builder
+ | Ast.Binary (op, lhs, rhs) ->
+ begin match op with
+ | '=' ->
+ (* Special case '=' because we don't want to emit the LHS as an
+ * expression. *)
+ let name =
+ match lhs with
+ | Ast.Variable name -> name
+ | _ -> raise (Error "destination of '=' must be a variable")
+ in
+
+ (* Codegen the rhs. *)
+ let val_ = codegen_expr rhs in
+
+ (* Lookup the name. *)
+ let variable = try Hashtbl.find named_values name with
+ | Not_found -> raise (Error "unknown variable name")
+ in
+ ignore(build_store val_ variable builder);
+ val_
+ | _ ->
+ let lhs_val = codegen_expr lhs in
+ let rhs_val = codegen_expr rhs in
+ begin
+ match op with
+ | '+' -> build_add lhs_val rhs_val "addtmp" builder
+ | '-' -> build_sub lhs_val rhs_val "subtmp" builder
+ | '*' -> build_mul lhs_val rhs_val "multmp" builder
+ | '<' ->
+ (* Convert bool 0/1 to double 0.0 or 1.0 *)
+ let i = build_fcmp Fcmp.Ult lhs_val rhs_val "cmptmp" builder in
+ build_uitofp i double_type "booltmp" builder
+ | _ ->
+ (* If it wasn't a builtin binary operator, it must be a user defined
+ * one. Emit a call to it. *)
+ let callee = "binary" ^ (String.make 1 op) in
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "binary operator not found!")
+ in
+ build_call callee [|lhs_val; rhs_val|] "binop" builder
+ end
+ end
+ | Ast.Call (callee, args) ->
+ (* Look up the name in the module table. *)
+ let callee =
+ match lookup_function callee the_module with
+ | Some callee -> callee
+ | None -> raise (Error "unknown function referenced")
+ in
+ let params = params callee in
+
+ (* If argument mismatch error. *)
+ if Array.length params == Array.length args then () else
+ raise (Error "incorrect # arguments passed");
+ let args = Array.map codegen_expr args in
+ build_call callee args "calltmp" builder
+ | Ast.If (cond, then_, else_) ->
+ let cond = codegen_expr cond in
+
+ (* Convert condition to a bool by comparing equal to 0.0 *)
+ let zero = const_float double_type 0.0 in
+ let cond_val = build_fcmp Fcmp.One cond zero "ifcond" builder in
+
+ (* Grab the first block so that we might later add the conditional branch
+ * to it at the end of the function. *)
+ let start_bb = insertion_block builder in
+ let the_function = block_parent start_bb in
+
+ let then_bb = append_block context "then" the_function in
+
+ (* Emit 'then' value. *)
+ position_at_end then_bb builder;
+ let then_val = codegen_expr then_ in
+
+ (* Codegen of 'then' can change the current block, update then_bb for the
+ * phi. We create a new name because one is used for the phi node, and the
+ * other is used for the conditional branch. *)
+ let new_then_bb = insertion_block builder in
+
+ (* Emit 'else' value. *)
+ let else_bb = append_block context "else" the_function in
+ position_at_end else_bb builder;
+ let else_val = codegen_expr else_ in
+
+ (* Codegen of 'else' can change the current block, update else_bb for the
+ * phi. *)
+ let new_else_bb = insertion_block builder in
+
+ (* Emit merge block. *)
+ let merge_bb = append_block context "ifcont" the_function in
+ position_at_end merge_bb builder;
+ let incoming = [(then_val, new_then_bb); (else_val, new_else_bb)] in
+ let phi = build_phi incoming "iftmp" builder in
+
+ (* Return to the start block to add the conditional branch. *)
+ position_at_end start_bb builder;
+ ignore (build_cond_br cond_val then_bb else_bb builder);
+
+ (* Set a unconditional branch at the end of the 'then' block and the
+ * 'else' block to the 'merge' block. *)
+ position_at_end new_then_bb builder; ignore (build_br merge_bb builder);
+ position_at_end new_else_bb builder; ignore (build_br merge_bb builder);
+
+ (* Finally, set the builder to the end of the merge block. *)
+ position_at_end merge_bb builder;
+
+ phi
+ | Ast.For (var_name, start, end_, step, body) ->
+ (* Output this as:
+ * var = alloca double
+ * ...
+ * start = startexpr
+ * store start -> var
+ * goto loop
+ * loop:
+ * ...
+ * bodyexpr
+ * ...
+ * loopend:
+ * step = stepexpr
+ * endcond = endexpr
+ *
+ * curvar = load var
+ * nextvar = curvar + step
+ * store nextvar -> var
+ * br endcond, loop, endloop
+ * outloop: *)
+
+ let the_function = block_parent (insertion_block builder) in
+
+ (* Create an alloca for the variable in the entry block. *)
+ let alloca = create_entry_block_alloca the_function var_name in
+
+ (* Emit the start code first, without 'variable' in scope. *)
+ let start_val = codegen_expr start in
+
+ (* Store the value into the alloca. *)
+ ignore(build_store start_val alloca builder);
+
+ (* Make the new basic block for the loop header, inserting after current
+ * block. *)
+ let loop_bb = append_block context "loop" the_function in
+
+ (* Insert an explicit fall through from the current block to the
+ * loop_bb. *)
+ ignore (build_br loop_bb builder);
+
+ (* Start insertion in loop_bb. *)
+ position_at_end loop_bb builder;
+
+ (* Within the loop, the variable is defined equal to the PHI node. If it
+ * shadows an existing variable, we have to restore it, so save it
+ * now. *)
+ let old_val =
+ try Some (Hashtbl.find named_values var_name) with Not_found -> None
+ in
+ Hashtbl.add named_values var_name alloca;
+
+ (* Emit the body of the loop. This, like any other expr, can change the
+ * current BB. Note that we ignore the value computed by the body, but
+ * don't allow an error *)
+ ignore (codegen_expr body);
+
+ (* Emit the step value. *)
+ let step_val =
+ match step with
+ | Some step -> codegen_expr step
+ (* If not specified, use 1.0. *)
+ | None -> const_float double_type 1.0
+ in
+
+ (* Compute the end condition. *)
+ let end_cond = codegen_expr end_ in
+
+ (* Reload, increment, and restore the alloca. This handles the case where
+ * the body of the loop mutates the variable. *)
+ let cur_var = build_load alloca var_name builder in
+ let next_var = build_add cur_var step_val "nextvar" builder in
+ ignore(build_store next_var alloca builder);
+
+ (* Convert condition to a bool by comparing equal to 0.0. *)
+ let zero = const_float double_type 0.0 in
+ let end_cond = build_fcmp Fcmp.One end_cond zero "loopcond" builder in
+
+ (* Create the "after loop" block and insert it. *)
+ let after_bb = append_block context "afterloop" the_function in
+
+ (* Insert the conditional branch into the end of loop_end_bb. *)
+ ignore (build_cond_br end_cond loop_bb after_bb builder);
+
+ (* Any new code will be inserted in after_bb. *)
+ position_at_end after_bb builder;
+
+ (* Restore the unshadowed variable. *)
+ begin match old_val with
+ | Some old_val -> Hashtbl.add named_values var_name old_val
+ | None -> ()
+ end;
+
+ (* for expr always returns 0.0. *)
+ const_null double_type
+ | Ast.Var (var_names, body) ->
+ let old_bindings = ref [] in
+
+ let the_function = block_parent (insertion_block builder) in
+
+ (* Register all variables and emit their initializer. *)
+ Array.iter (fun (var_name, init) ->
+ (* Emit the initializer before adding the variable to scope, this
+ * prevents the initializer from referencing the variable itself, and
+ * permits stuff like this:
+ * var a = 1 in
+ * var a = a in ... # refers to outer 'a'. *)
+ let init_val =
+ match init with
+ | Some init -> codegen_expr init
+ (* If not specified, use 0.0. *)
+ | None -> const_float double_type 0.0
+ in
+
+ let alloca = create_entry_block_alloca the_function var_name in
+ ignore(build_store init_val alloca builder);
+
+ (* Remember the old variable binding so that we can restore the binding
+ * when we unrecurse. *)
+ begin
+ try
+ let old_value = Hashtbl.find named_values var_name in
+ old_bindings := (var_name, old_value) :: !old_bindings;
+ with Not_found -> ()
+ end;
+
+ (* Remember this binding. *)
+ Hashtbl.add named_values var_name alloca;
+ ) var_names;
+
+ (* Codegen the body, now that all vars are in scope. *)
+ let body_val = codegen_expr body in
+
+ (* Pop all our variables from scope. *)
+ List.iter (fun (var_name, old_value) ->
+ Hashtbl.add named_values var_name old_value
+ ) !old_bindings;
+
+ (* Return the body computation. *)
+ body_val
+
+ let codegen_proto = function
+ | Ast.Prototype (name, args) | Ast.BinOpPrototype (name, args, _) ->
+ (* Make the function type: double(double,double) etc. *)
+ let doubles = Array.make (Array.length args) double_type in
+ let ft = function_type double_type doubles in
+ let f =
+ match lookup_function name the_module with
+ | None -> declare_function name ft the_module
+
+ (* If 'f' conflicted, there was already something named 'name'. If it
+ * has a body, don't allow redefinition or reextern. *)
+ | Some f ->
+ (* If 'f' already has a body, reject this. *)
+ if block_begin f <> At_end f then
+ raise (Error "redefinition of function");
+
+ (* If 'f' took a different number of arguments, reject. *)
+ if element_type (type_of f) <> ft then
+ raise (Error "redefinition of function with different # args");
+ f
+ in
+
+ (* Set names for all arguments. *)
+ Array.iteri (fun i a ->
+ let n = args.(i) in
+ set_value_name n a;
+ Hashtbl.add named_values n a;
+ ) (params f);
+ f
+
+ (* Create an alloca for each argument and register the argument in the symbol
+ * table so that references to it will succeed. *)
+ let create_argument_allocas the_function proto =
+ let args = match proto with
+ | Ast.Prototype (_, args) | Ast.BinOpPrototype (_, args, _) -> args
+ in
+ Array.iteri (fun i ai ->
+ let var_name = args.(i) in
+ (* Create an alloca for this variable. *)
+ let alloca = create_entry_block_alloca the_function var_name in
+
+ (* Store the initial value into the alloca. *)
+ ignore(build_store ai alloca builder);
+
+ (* Add arguments to variable symbol table. *)
+ Hashtbl.add named_values var_name alloca;
+ ) (params the_function)
+
+ let codegen_func the_fpm = function
+ | Ast.Function (proto, body) ->
+ Hashtbl.clear named_values;
+ let the_function = codegen_proto proto in
+
+ (* If this is an operator, install it. *)
+ begin match proto with
+ | Ast.BinOpPrototype (name, args, prec) ->
+ let op = name.[String.length name - 1] in
+ Hashtbl.add Parser.binop_precedence op prec;
+ | _ -> ()
+ end;
+
+ (* Create a new basic block to start insertion into. *)
+ let bb = append_block context "entry" the_function in
+ position_at_end bb builder;
+
+ try
+ (* Add all arguments to the symbol table and create their allocas. *)
+ create_argument_allocas the_function proto;
+
+ let ret_val = codegen_expr body in
+
+ (* Finish off the function. *)
+ let _ = build_ret ret_val builder in
+
+ (* Validate the generated code, checking for consistency. *)
+ Llvm_analysis.assert_valid_function the_function;
+
+ (* Optimize the function. *)
+ let _ = PassManager.run_function the_function the_fpm in
+
+ the_function
+ with e ->
+ delete_function the_function;
+ raise e
+
+toplevel.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Top-Level parsing and JIT Driver
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+
+ (* top ::= definition | external | expression | ';' *)
+ let rec main_loop the_fpm the_execution_engine stream =
+ match Stream.peek stream with
+ | None -> ()
+
+ (* ignore top-level semicolons. *)
+ | Some (Token.Kwd ';') ->
+ Stream.junk stream;
+ main_loop the_fpm the_execution_engine stream
+
+ | Some token ->
+ begin
+ try match token with
+ | Token.Def ->
+ let e = Parser.parse_definition stream in
+ print_endline "parsed a function definition.";
+ dump_value (Codegen.codegen_func the_fpm e);
+ | Token.Extern ->
+ let e = Parser.parse_extern stream in
+ print_endline "parsed an extern.";
+ dump_value (Codegen.codegen_proto e);
+ | _ ->
+ (* Evaluate a top-level expression into an anonymous function. *)
+ let e = Parser.parse_toplevel stream in
+ print_endline "parsed a top-level expr";
+ let the_function = Codegen.codegen_func the_fpm e in
+ dump_value the_function;
+
+ (* JIT the function, returning a function pointer. *)
+ let result = ExecutionEngine.run_function the_function [||]
+ the_execution_engine in
+
+ print_string "Evaluated to ";
+ print_float (GenericValue.as_float Codegen.double_type result);
+ print_newline ();
+ with Stream.Error s | Codegen.Error s ->
+ (* Skip token for error recovery. *)
+ Stream.junk stream;
+ print_endline s;
+ end;
+ print_string "ready> "; flush stdout;
+ main_loop the_fpm the_execution_engine stream
+
+toy.ml:
+ .. code-block:: ocaml
+
+ (*===----------------------------------------------------------------------===
+ * Main driver code.
+ *===----------------------------------------------------------------------===*)
+
+ open Llvm
+ open Llvm_executionengine
+ open Llvm_target
+ open Llvm_scalar_opts
+
+ let main () =
+ ignore (initialize_native_target ());
+
+ (* Install standard binary operators.
+ * 1 is the lowest precedence. *)
+ Hashtbl.add Parser.binop_precedence '=' 2;
+ Hashtbl.add Parser.binop_precedence '<' 10;
+ Hashtbl.add Parser.binop_precedence '+' 20;
+ Hashtbl.add Parser.binop_precedence '-' 20;
+ Hashtbl.add Parser.binop_precedence '*' 40; (* highest. *)
+
+ (* Prime the first token. *)
+ print_string "ready> "; flush stdout;
+ let stream = Lexer.lex (Stream.of_channel stdin) in
+
+ (* Create the JIT. *)
+ let the_execution_engine = ExecutionEngine.create Codegen.the_module in
+ let the_fpm = PassManager.create_function Codegen.the_module in
+
+ (* Set up the optimizer pipeline. Start with registering info about how the
+ * target lays out data structures. *)
+ DataLayout.add (ExecutionEngine.target_data the_execution_engine) the_fpm;
+
+ (* Promote allocas to registers. *)
+ add_memory_to_register_promotion the_fpm;
+
+ (* Do simple "peephole" optimizations and bit-twiddling optzn. *)
+ add_instruction_combination the_fpm;
+
+ (* reassociate expressions. *)
+ add_reassociation the_fpm;
+
+ (* Eliminate Common SubExpressions. *)
+ add_gvn the_fpm;
+
+ (* Simplify the control flow graph (deleting unreachable blocks, etc). *)
+ add_cfg_simplification the_fpm;
+
+ ignore (PassManager.initialize the_fpm);
+
+ (* Run the main "interpreter loop" now. *)
+ Toplevel.main_loop the_fpm the_execution_engine stream;
+
+ (* Print out all the generated code. *)
+ dump_module Codegen.the_module
+ ;;
+
+ main ()
+
+bindings.c
+ .. code-block:: c
+
+ #include <stdio.h>
+
+ /* putchard - putchar that takes a double and returns 0. */
+ extern double putchard(double X) {
+ putchar((char)X);
+ return 0;
+ }
+
+ /* printd - printf that takes a double prints it as "%f\n", returning 0. */
+ extern double printd(double X) {
+ printf("%f\n", X);
+ return 0;
+ }
+
+`Next: Conclusion and other useful LLVM tidbits <OCamlLangImpl8.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl8.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl8.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl8.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/OCamlLangImpl8.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,267 @@
+======================================================
+Kaleidoscope: Conclusion and other useful LLVM tidbits
+======================================================
+
+.. contents::
+ :local:
+
+Tutorial Conclusion
+===================
+
+Welcome to the final chapter of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In the course of this tutorial, we have
+grown our little Kaleidoscope language from being a useless toy, to
+being a semi-interesting (but probably still useless) toy. :)
+
+It is interesting to see how far we've come, and how little code it has
+taken. We built the entire lexer, parser, AST, code generator, and an
+interactive run-loop (with a JIT!) by-hand in under 700 lines of
+(non-comment/non-blank) code.
+
+Our little language supports a couple of interesting features: it
+supports user defined binary and unary operators, it uses JIT
+compilation for immediate evaluation, and it supports a few control flow
+constructs with SSA construction.
+
+Part of the idea of this tutorial was to show you how easy and fun it
+can be to define, build, and play with languages. Building a compiler
+need not be a scary or mystical process! Now that you've seen some of
+the basics, I strongly encourage you to take the code and hack on it.
+For example, try adding:
+
+- **global variables** - While global variables have questional value
+ in modern software engineering, they are often useful when putting
+ together quick little hacks like the Kaleidoscope compiler itself.
+ Fortunately, our current setup makes it very easy to add global
+ variables: just have value lookup check to see if an unresolved
+ variable is in the global variable symbol table before rejecting it.
+ To create a new global variable, make an instance of the LLVM
+ ``GlobalVariable`` class.
+- **typed variables** - Kaleidoscope currently only supports variables
+ of type double. This gives the language a very nice elegance, because
+ only supporting one type means that you never have to specify types.
+ Different languages have different ways of handling this. The easiest
+ way is to require the user to specify types for every variable
+ definition, and record the type of the variable in the symbol table
+ along with its Value\*.
+- **arrays, structs, vectors, etc** - Once you add types, you can start
+ extending the type system in all sorts of interesting ways. Simple
+ arrays are very easy and are quite useful for many different
+ applications. Adding them is mostly an exercise in learning how the
+ LLVM `getelementptr <../LangRef.html#getelementptr-instruction>`_ instruction
+ works: it is so nifty/unconventional, it `has its own
+ FAQ <../GetElementPtr.html>`_! If you add support for recursive types
+ (e.g. linked lists), make sure to read the `section in the LLVM
+ Programmer's Manual <../ProgrammersManual.html#TypeResolve>`_ that
+ describes how to construct them.
+- **standard runtime** - Our current language allows the user to access
+ arbitrary external functions, and we use it for things like "printd"
+ and "putchard". As you extend the language to add higher-level
+ constructs, often these constructs make the most sense if they are
+ lowered to calls into a language-supplied runtime. For example, if
+ you add hash tables to the language, it would probably make sense to
+ add the routines to a runtime, instead of inlining them all the way.
+- **memory management** - Currently we can only access the stack in
+ Kaleidoscope. It would also be useful to be able to allocate heap
+ memory, either with calls to the standard libc malloc/free interface
+ or with a garbage collector. If you would like to use garbage
+ collection, note that LLVM fully supports `Accurate Garbage
+ Collection <../GarbageCollection.html>`_ including algorithms that
+ move objects and need to scan/update the stack.
+- **debugger support** - LLVM supports generation of `DWARF Debug
+ info <../SourceLevelDebugging.html>`_ which is understood by common
+ debuggers like GDB. Adding support for debug info is fairly
+ straightforward. The best way to understand it is to compile some
+ C/C++ code with "``clang -g -O0``" and taking a look at what it
+ produces.
+- **exception handling support** - LLVM supports generation of `zero
+ cost exceptions <../ExceptionHandling.html>`_ which interoperate with
+ code compiled in other languages. You could also generate code by
+ implicitly making every function return an error value and checking
+ it. You could also make explicit use of setjmp/longjmp. There are
+ many different ways to go here.
+- **object orientation, generics, database access, complex numbers,
+ geometric programming, ...** - Really, there is no end of crazy
+ features that you can add to the language.
+- **unusual domains** - We've been talking about applying LLVM to a
+ domain that many people are interested in: building a compiler for a
+ specific language. However, there are many other domains that can use
+ compiler technology that are not typically considered. For example,
+ LLVM has been used to implement OpenGL graphics acceleration,
+ translate C++ code to ActionScript, and many other cute and clever
+ things. Maybe you will be the first to JIT compile a regular
+ expression interpreter into native code with LLVM?
+
+Have fun - try doing something crazy and unusual. Building a language
+like everyone else always has, is much less fun than trying something a
+little crazy or off the wall and seeing how it turns out. If you get
+stuck or want to talk about it, feel free to email the `llvm-dev mailing
+list <http://lists.llvm.org/mailman/listinfo/llvm-dev>`_: it has lots
+of people who are interested in languages and are often willing to help
+out.
+
+Before we end this tutorial, I want to talk about some "tips and tricks"
+for generating LLVM IR. These are some of the more subtle things that
+may not be obvious, but are very useful if you want to take advantage of
+LLVM's capabilities.
+
+Properties of the LLVM IR
+=========================
+
+We have a couple common questions about code in the LLVM IR form - lets
+just get these out of the way right now, shall we?
+
+Target Independence
+-------------------
+
+Kaleidoscope is an example of a "portable language": any program written
+in Kaleidoscope will work the same way on any target that it runs on.
+Many other languages have this property, e.g. lisp, java, haskell,
+javascript, python, etc (note that while these languages are portable,
+not all their libraries are).
+
+One nice aspect of LLVM is that it is often capable of preserving target
+independence in the IR: you can take the LLVM IR for a
+Kaleidoscope-compiled program and run it on any target that LLVM
+supports, even emitting C code and compiling that on targets that LLVM
+doesn't support natively. You can trivially tell that the Kaleidoscope
+compiler generates target-independent code because it never queries for
+any target-specific information when generating code.
+
+The fact that LLVM provides a compact, target-independent,
+representation for code gets a lot of people excited. Unfortunately,
+these people are usually thinking about C or a language from the C
+family when they are asking questions about language portability. I say
+"unfortunately", because there is really no way to make (fully general)
+C code portable, other than shipping the source code around (and of
+course, C source code is not actually portable in general either - ever
+port a really old application from 32- to 64-bits?).
+
+The problem with C (again, in its full generality) is that it is heavily
+laden with target specific assumptions. As one simple example, the
+preprocessor often destructively removes target-independence from the
+code when it processes the input text:
+
+.. code-block:: c
+
+ #ifdef __i386__
+ int X = 1;
+ #else
+ int X = 42;
+ #endif
+
+While it is possible to engineer more and more complex solutions to
+problems like this, it cannot be solved in full generality in a way that
+is better than shipping the actual source code.
+
+That said, there are interesting subsets of C that can be made portable.
+If you are willing to fix primitive types to a fixed size (say int =
+32-bits, and long = 64-bits), don't care about ABI compatibility with
+existing binaries, and are willing to give up some other minor features,
+you can have portable code. This can make sense for specialized domains
+such as an in-kernel language.
+
+Safety Guarantees
+-----------------
+
+Many of the languages above are also "safe" languages: it is impossible
+for a program written in Java to corrupt its address space and crash the
+process (assuming the JVM has no bugs). Safety is an interesting
+property that requires a combination of language design, runtime
+support, and often operating system support.
+
+It is certainly possible to implement a safe language in LLVM, but LLVM
+IR does not itself guarantee safety. The LLVM IR allows unsafe pointer
+casts, use after free bugs, buffer over-runs, and a variety of other
+problems. Safety needs to be implemented as a layer on top of LLVM and,
+conveniently, several groups have investigated this. Ask on the `llvm-dev
+mailing list <http://lists.llvm.org/mailman/listinfo/llvm-dev>`_ if
+you are interested in more details.
+
+Language-Specific Optimizations
+-------------------------------
+
+One thing about LLVM that turns off many people is that it does not
+solve all the world's problems in one system (sorry 'world hunger',
+someone else will have to solve you some other day). One specific
+complaint is that people perceive LLVM as being incapable of performing
+high-level language-specific optimization: LLVM "loses too much
+information".
+
+Unfortunately, this is really not the place to give you a full and
+unified version of "Chris Lattner's theory of compiler design". Instead,
+I'll make a few observations:
+
+First, you're right that LLVM does lose information. For example, as of
+this writing, there is no way to distinguish in the LLVM IR whether an
+SSA-value came from a C "int" or a C "long" on an ILP32 machine (other
+than debug info). Both get compiled down to an 'i32' value and the
+information about what it came from is lost. The more general issue
+here, is that the LLVM type system uses "structural equivalence" instead
+of "name equivalence". Another place this surprises people is if you
+have two types in a high-level language that have the same structure
+(e.g. two different structs that have a single int field): these types
+will compile down into a single LLVM type and it will be impossible to
+tell what it came from.
+
+Second, while LLVM does lose information, LLVM is not a fixed target: we
+continue to enhance and improve it in many different ways. In addition
+to adding new features (LLVM did not always support exceptions or debug
+info), we also extend the IR to capture important information for
+optimization (e.g. whether an argument is sign or zero extended,
+information about pointers aliasing, etc). Many of the enhancements are
+user-driven: people want LLVM to include some specific feature, so they
+go ahead and extend it.
+
+Third, it is *possible and easy* to add language-specific optimizations,
+and you have a number of choices in how to do it. As one trivial
+example, it is easy to add language-specific optimization passes that
+"know" things about code compiled for a language. In the case of the C
+family, there is an optimization pass that "knows" about the standard C
+library functions. If you call "exit(0)" in main(), it knows that it is
+safe to optimize that into "return 0;" because C specifies what the
+'exit' function does.
+
+In addition to simple library knowledge, it is possible to embed a
+variety of other language-specific information into the LLVM IR. If you
+have a specific need and run into a wall, please bring the topic up on
+the llvm-dev list. At the very worst, you can always treat LLVM as if it
+were a "dumb code generator" and implement the high-level optimizations
+you desire in your front-end, on the language-specific AST.
+
+Tips and Tricks
+===============
+
+There is a variety of useful tips and tricks that you come to know after
+working on/with LLVM that aren't obvious at first glance. Instead of
+letting everyone rediscover them, this section talks about some of these
+issues.
+
+Implementing portable offsetof/sizeof
+-------------------------------------
+
+One interesting thing that comes up, if you are trying to keep the code
+generated by your compiler "target independent", is that you often need
+to know the size of some LLVM type or the offset of some field in an
+llvm structure. For example, you might need to pass the size of a type
+into a function that allocates memory.
+
+Unfortunately, this can vary widely across targets: for example the
+width of a pointer is trivially target-specific. However, there is a
+`clever way to use the getelementptr
+instruction <http://nondot.org/sabre/LLVMNotes/SizeOf-OffsetOf-VariableSizedStructs.txt>`_
+that allows you to compute this in a portable way.
+
+Garbage Collected Stack Frames
+------------------------------
+
+Some languages want to explicitly manage their stack frames, often so
+that they are garbage collected or to allow easy implementation of
+closures. There are often better ways to implement these features than
+explicit stack frames, but `LLVM does support
+them, <http://nondot.org/sabre/LLVMNotes/ExplicitlyManagedStackFrames.txt>`_
+if you want. It requires your front-end to convert the code into
+`Continuation Passing
+Style <http://en.wikipedia.org/wiki/Continuation-passing_style>`_ and
+the use of tail calls (which LLVM also supports).
+
Added: www-releases/trunk/8.0.0/docs/_sources/tutorial/index.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/tutorial/index.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/tutorial/index.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/tutorial/index.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,53 @@
+================================
+LLVM Tutorial: Table of Contents
+================================
+
+Kaleidoscope: Implementing a Language with LLVM
+===============================================
+
+.. toctree::
+ :titlesonly:
+ :glob:
+ :numbered:
+
+ LangImpl*
+
+Kaleidoscope: Implementing a Language with LLVM in Objective Caml
+=================================================================
+
+.. toctree::
+ :titlesonly:
+ :glob:
+ :numbered:
+
+ OCamlLangImpl*
+
+Building a JIT in LLVM
+===============================================
+
+.. toctree::
+ :titlesonly:
+ :glob:
+ :numbered:
+
+ BuildingAJIT*
+
+External Tutorials
+==================
+
+`Tutorial: Creating an LLVM Backend for the Cpu0 Architecture <http://jonathan2251.github.com/lbd/>`_
+ A step-by-step tutorial for developing an LLVM backend. Under
+ active development at `<https://github.com/Jonathan2251/lbd>`_ (please
+ contribute!).
+
+`Howto: Implementing LLVM Integrated Assembler`_
+ A simple guide for how to implement an LLVM integrated assembler for an
+ architecture.
+
+.. _`Howto: Implementing LLVM Integrated Assembler`: http://www.embecosm.com/appnotes/ean10/ean10-howto-llvmas-1.0.html
+
+Advanced Topics
+===============
+
+#. `Writing an Optimization for LLVM <http://llvm.org/pubs/2004-09-22-LCPCLLVMTutorial.html>`_
+
Added: www-releases/trunk/8.0.0/docs/_sources/yaml2obj.rst.txt
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_sources/yaml2obj.rst.txt?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_sources/yaml2obj.rst.txt (added)
+++ www-releases/trunk/8.0.0/docs/_sources/yaml2obj.rst.txt Wed Mar 20 02:13:27 2019
@@ -0,0 +1,221 @@
+yaml2obj
+========
+
+yaml2obj takes a YAML description of an object file and converts it to a binary
+file.
+
+ $ yaml2obj input-file
+
+.. program:: yaml2obj
+
+Outputs the binary to stdout.
+
+COFF Syntax
+-----------
+
+Here's a sample COFF file.
+
+.. code-block:: yaml
+
+ header:
+ Machine: IMAGE_FILE_MACHINE_I386 # (0x14C)
+
+ sections:
+ - Name: .text
+ Characteristics: [ IMAGE_SCN_CNT_CODE
+ , IMAGE_SCN_ALIGN_16BYTES
+ , IMAGE_SCN_MEM_EXECUTE
+ , IMAGE_SCN_MEM_READ
+ ] # 0x60500020
+ SectionData:
+ "\x83\xEC\x0C\xC7\x44\x24\x08\x00\x00\x00\x00\xC7\x04\x24\x00\x00\x00\x00\xE8\x00\x00\x00\x00\xE8\x00\x00\x00\x00\x8B\x44\x24\x08\x83\xC4\x0C\xC3" # |....D$.......$...............D$.....|
+
+ symbols:
+ - Name: .text
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL # (0)
+ ComplexType: IMAGE_SYM_DTYPE_NULL # (0)
+ StorageClass: IMAGE_SYM_CLASS_STATIC # (3)
+ NumberOfAuxSymbols: 1
+ AuxiliaryData:
+ "\x24\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00\x00\x01\x00\x00\x00\x00\x00" # |$.................|
+
+ - Name: _main
+ Value: 0
+ SectionNumber: 1
+ SimpleType: IMAGE_SYM_TYPE_NULL # (0)
+ ComplexType: IMAGE_SYM_DTYPE_NULL # (0)
+ StorageClass: IMAGE_SYM_CLASS_EXTERNAL # (2)
+
+Here's a simplified Kwalify_ schema with an extension to allow alternate types.
+
+.. _Kwalify: http://www.kuwata-lab.com/kwalify/ruby/users-guide.html
+
+.. code-block:: yaml
+
+ type: map
+ mapping:
+ header:
+ type: map
+ mapping:
+ Machine: [ {type: str, enum:
+ [ IMAGE_FILE_MACHINE_UNKNOWN
+ , IMAGE_FILE_MACHINE_AM33
+ , IMAGE_FILE_MACHINE_AMD64
+ , IMAGE_FILE_MACHINE_ARM
+ , IMAGE_FILE_MACHINE_ARMNT
+ , IMAGE_FILE_MACHINE_ARM64
+ , IMAGE_FILE_MACHINE_EBC
+ , IMAGE_FILE_MACHINE_I386
+ , IMAGE_FILE_MACHINE_IA64
+ , IMAGE_FILE_MACHINE_M32R
+ , IMAGE_FILE_MACHINE_MIPS16
+ , IMAGE_FILE_MACHINE_MIPSFPU
+ , IMAGE_FILE_MACHINE_MIPSFPU16
+ , IMAGE_FILE_MACHINE_POWERPC
+ , IMAGE_FILE_MACHINE_POWERPCFP
+ , IMAGE_FILE_MACHINE_R4000
+ , IMAGE_FILE_MACHINE_SH3
+ , IMAGE_FILE_MACHINE_SH3DSP
+ , IMAGE_FILE_MACHINE_SH4
+ , IMAGE_FILE_MACHINE_SH5
+ , IMAGE_FILE_MACHINE_THUMB
+ , IMAGE_FILE_MACHINE_WCEMIPSV2
+ ]}
+ , {type: int}
+ ]
+ Characteristics:
+ - type: seq
+ sequence:
+ - type: str
+ enum: [ IMAGE_FILE_RELOCS_STRIPPED
+ , IMAGE_FILE_EXECUTABLE_IMAGE
+ , IMAGE_FILE_LINE_NUMS_STRIPPED
+ , IMAGE_FILE_LOCAL_SYMS_STRIPPED
+ , IMAGE_FILE_AGGRESSIVE_WS_TRIM
+ , IMAGE_FILE_LARGE_ADDRESS_AWARE
+ , IMAGE_FILE_BYTES_REVERSED_LO
+ , IMAGE_FILE_32BIT_MACHINE
+ , IMAGE_FILE_DEBUG_STRIPPED
+ , IMAGE_FILE_REMOVABLE_RUN_FROM_SWAP
+ , IMAGE_FILE_NET_RUN_FROM_SWAP
+ , IMAGE_FILE_SYSTEM
+ , IMAGE_FILE_DLL
+ , IMAGE_FILE_UP_SYSTEM_ONLY
+ , IMAGE_FILE_BYTES_REVERSED_HI
+ ]
+ - type: int
+ sections:
+ type: seq
+ sequence:
+ - type: map
+ mapping:
+ Name: {type: str}
+ Characteristics:
+ - type: seq
+ sequence:
+ - type: str
+ enum: [ IMAGE_SCN_TYPE_NO_PAD
+ , IMAGE_SCN_CNT_CODE
+ , IMAGE_SCN_CNT_INITIALIZED_DATA
+ , IMAGE_SCN_CNT_UNINITIALIZED_DATA
+ , IMAGE_SCN_LNK_OTHER
+ , IMAGE_SCN_LNK_INFO
+ , IMAGE_SCN_LNK_REMOVE
+ , IMAGE_SCN_LNK_COMDAT
+ , IMAGE_SCN_GPREL
+ , IMAGE_SCN_MEM_PURGEABLE
+ , IMAGE_SCN_MEM_16BIT
+ , IMAGE_SCN_MEM_LOCKED
+ , IMAGE_SCN_MEM_PRELOAD
+ , IMAGE_SCN_ALIGN_1BYTES
+ , IMAGE_SCN_ALIGN_2BYTES
+ , IMAGE_SCN_ALIGN_4BYTES
+ , IMAGE_SCN_ALIGN_8BYTES
+ , IMAGE_SCN_ALIGN_16BYTES
+ , IMAGE_SCN_ALIGN_32BYTES
+ , IMAGE_SCN_ALIGN_64BYTES
+ , IMAGE_SCN_ALIGN_128BYTES
+ , IMAGE_SCN_ALIGN_256BYTES
+ , IMAGE_SCN_ALIGN_512BYTES
+ , IMAGE_SCN_ALIGN_1024BYTES
+ , IMAGE_SCN_ALIGN_2048BYTES
+ , IMAGE_SCN_ALIGN_4096BYTES
+ , IMAGE_SCN_ALIGN_8192BYTES
+ , IMAGE_SCN_LNK_NRELOC_OVFL
+ , IMAGE_SCN_MEM_DISCARDABLE
+ , IMAGE_SCN_MEM_NOT_CACHED
+ , IMAGE_SCN_MEM_NOT_PAGED
+ , IMAGE_SCN_MEM_SHARED
+ , IMAGE_SCN_MEM_EXECUTE
+ , IMAGE_SCN_MEM_READ
+ , IMAGE_SCN_MEM_WRITE
+ ]
+ - type: int
+ SectionData: {type: str}
+ symbols:
+ type: seq
+ sequence:
+ - type: map
+ mapping:
+ Name: {type: str}
+ Value: {type: int}
+ SectionNumber: {type: int}
+ SimpleType: [ {type: str, enum: [ IMAGE_SYM_TYPE_NULL
+ , IMAGE_SYM_TYPE_VOID
+ , IMAGE_SYM_TYPE_CHAR
+ , IMAGE_SYM_TYPE_SHORT
+ , IMAGE_SYM_TYPE_INT
+ , IMAGE_SYM_TYPE_LONG
+ , IMAGE_SYM_TYPE_FLOAT
+ , IMAGE_SYM_TYPE_DOUBLE
+ , IMAGE_SYM_TYPE_STRUCT
+ , IMAGE_SYM_TYPE_UNION
+ , IMAGE_SYM_TYPE_ENUM
+ , IMAGE_SYM_TYPE_MOE
+ , IMAGE_SYM_TYPE_BYTE
+ , IMAGE_SYM_TYPE_WORD
+ , IMAGE_SYM_TYPE_UINT
+ , IMAGE_SYM_TYPE_DWORD
+ ]}
+ , {type: int}
+ ]
+ ComplexType: [ {type: str, enum: [ IMAGE_SYM_DTYPE_NULL
+ , IMAGE_SYM_DTYPE_POINTER
+ , IMAGE_SYM_DTYPE_FUNCTION
+ , IMAGE_SYM_DTYPE_ARRAY
+ ]}
+ , {type: int}
+ ]
+ StorageClass: [ {type: str, enum:
+ [ IMAGE_SYM_CLASS_END_OF_FUNCTION
+ , IMAGE_SYM_CLASS_NULL
+ , IMAGE_SYM_CLASS_AUTOMATIC
+ , IMAGE_SYM_CLASS_EXTERNAL
+ , IMAGE_SYM_CLASS_STATIC
+ , IMAGE_SYM_CLASS_REGISTER
+ , IMAGE_SYM_CLASS_EXTERNAL_DEF
+ , IMAGE_SYM_CLASS_LABEL
+ , IMAGE_SYM_CLASS_UNDEFINED_LABEL
+ , IMAGE_SYM_CLASS_MEMBER_OF_STRUCT
+ , IMAGE_SYM_CLASS_ARGUMENT
+ , IMAGE_SYM_CLASS_STRUCT_TAG
+ , IMAGE_SYM_CLASS_MEMBER_OF_UNION
+ , IMAGE_SYM_CLASS_UNION_TAG
+ , IMAGE_SYM_CLASS_TYPE_DEFINITION
+ , IMAGE_SYM_CLASS_UNDEFINED_STATIC
+ , IMAGE_SYM_CLASS_ENUM_TAG
+ , IMAGE_SYM_CLASS_MEMBER_OF_ENUM
+ , IMAGE_SYM_CLASS_REGISTER_PARAM
+ , IMAGE_SYM_CLASS_BIT_FIELD
+ , IMAGE_SYM_CLASS_BLOCK
+ , IMAGE_SYM_CLASS_FUNCTION
+ , IMAGE_SYM_CLASS_END_OF_STRUCT
+ , IMAGE_SYM_CLASS_FILE
+ , IMAGE_SYM_CLASS_SECTION
+ , IMAGE_SYM_CLASS_WEAK_EXTERNAL
+ , IMAGE_SYM_CLASS_CLR_TOKEN
+ ]}
+ , {type: int}
+ ]
Added: www-releases/trunk/8.0.0/docs/_static/ajax-loader.gif
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/ajax-loader.gif?rev=356539&view=auto
==============================================================================
Binary file - no diff available.
Propchange: www-releases/trunk/8.0.0/docs/_static/ajax-loader.gif
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Added: www-releases/trunk/8.0.0/docs/_static/basic.css
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/basic.css?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/basic.css (added)
+++ www-releases/trunk/8.0.0/docs/_static/basic.css Wed Mar 20 02:13:27 2019
@@ -0,0 +1,665 @@
+/*
+ * basic.css
+ * ~~~~~~~~~
+ *
+ * Sphinx stylesheet -- basic theme.
+ *
+ * :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
+ * :license: BSD, see LICENSE for details.
+ *
+ */
+
+/* -- main layout ----------------------------------------------------------- */
+
+div.clearer {
+ clear: both;
+}
+
+/* -- relbar ---------------------------------------------------------------- */
+
+div.related {
+ width: 100%;
+ font-size: 90%;
+}
+
+div.related h3 {
+ display: none;
+}
+
+div.related ul {
+ margin: 0;
+ padding: 0 0 0 10px;
+ list-style: none;
+}
+
+div.related li {
+ display: inline;
+}
+
+div.related li.right {
+ float: right;
+ margin-right: 5px;
+}
+
+/* -- sidebar --------------------------------------------------------------- */
+
+div.sphinxsidebarwrapper {
+ padding: 10px 5px 0 10px;
+}
+
+div.sphinxsidebar {
+ float: left;
+ width: 230px;
+ margin-left: -100%;
+ font-size: 90%;
+ word-wrap: break-word;
+ overflow-wrap : break-word;
+}
+
+div.sphinxsidebar ul {
+ list-style: none;
+}
+
+div.sphinxsidebar ul ul,
+div.sphinxsidebar ul.want-points {
+ margin-left: 20px;
+ list-style: square;
+}
+
+div.sphinxsidebar ul ul {
+ margin-top: 0;
+ margin-bottom: 0;
+}
+
+div.sphinxsidebar form {
+ margin-top: 10px;
+}
+
+div.sphinxsidebar input {
+ border: 1px solid #98dbcc;
+ font-family: sans-serif;
+ font-size: 1em;
+}
+
+div.sphinxsidebar #searchbox input[type="text"] {
+ float: left;
+ width: 80%;
+ padding: 0.25em;
+ box-sizing: border-box;
+}
+
+div.sphinxsidebar #searchbox input[type="submit"] {
+ float: left;
+ width: 20%;
+ border-left: none;
+ padding: 0.25em;
+ box-sizing: border-box;
+}
+
+
+img {
+ border: 0;
+ max-width: 100%;
+}
+
+/* -- search page ----------------------------------------------------------- */
+
+ul.search {
+ margin: 10px 0 0 20px;
+ padding: 0;
+}
+
+ul.search li {
+ padding: 5px 0 5px 20px;
+ background-image: url(file.png);
+ background-repeat: no-repeat;
+ background-position: 0 7px;
+}
+
+ul.search li a {
+ font-weight: bold;
+}
+
+ul.search li div.context {
+ color: #888;
+ margin: 2px 0 0 30px;
+ text-align: left;
+}
+
+ul.keywordmatches li.goodmatch a {
+ font-weight: bold;
+}
+
+/* -- index page ------------------------------------------------------------ */
+
+table.contentstable {
+ width: 90%;
+ margin-left: auto;
+ margin-right: auto;
+}
+
+table.contentstable p.biglink {
+ line-height: 150%;
+}
+
+a.biglink {
+ font-size: 1.3em;
+}
+
+span.linkdescr {
+ font-style: italic;
+ padding-top: 5px;
+ font-size: 90%;
+}
+
+/* -- general index --------------------------------------------------------- */
+
+table.indextable {
+ width: 100%;
+}
+
+table.indextable td {
+ text-align: left;
+ vertical-align: top;
+}
+
+table.indextable ul {
+ margin-top: 0;
+ margin-bottom: 0;
+ list-style-type: none;
+}
+
+table.indextable > tbody > tr > td > ul {
+ padding-left: 0em;
+}
+
+table.indextable tr.pcap {
+ height: 10px;
+}
+
+table.indextable tr.cap {
+ margin-top: 10px;
+ background-color: #f2f2f2;
+}
+
+img.toggler {
+ margin-right: 3px;
+ margin-top: 3px;
+ cursor: pointer;
+}
+
+div.modindex-jumpbox {
+ border-top: 1px solid #ddd;
+ border-bottom: 1px solid #ddd;
+ margin: 1em 0 1em 0;
+ padding: 0.4em;
+}
+
+div.genindex-jumpbox {
+ border-top: 1px solid #ddd;
+ border-bottom: 1px solid #ddd;
+ margin: 1em 0 1em 0;
+ padding: 0.4em;
+}
+
+/* -- domain module index --------------------------------------------------- */
+
+table.modindextable td {
+ padding: 2px;
+ border-collapse: collapse;
+}
+
+/* -- general body styles --------------------------------------------------- */
+
+div.body {
+ min-width: 450px;
+ max-width: 800px;
+}
+
+div.body p, div.body dd, div.body li, div.body blockquote {
+ -moz-hyphens: auto;
+ -ms-hyphens: auto;
+ -webkit-hyphens: auto;
+ hyphens: auto;
+}
+
+a.headerlink {
+ visibility: hidden;
+}
+
+h1:hover > a.headerlink,
+h2:hover > a.headerlink,
+h3:hover > a.headerlink,
+h4:hover > a.headerlink,
+h5:hover > a.headerlink,
+h6:hover > a.headerlink,
+dt:hover > a.headerlink,
+caption:hover > a.headerlink,
+p.caption:hover > a.headerlink,
+div.code-block-caption:hover > a.headerlink {
+ visibility: visible;
+}
+
+div.body p.caption {
+ text-align: inherit;
+}
+
+div.body td {
+ text-align: left;
+}
+
+.first {
+ margin-top: 0 !important;
+}
+
+p.rubric {
+ margin-top: 30px;
+ font-weight: bold;
+}
+
+img.align-left, .figure.align-left, object.align-left {
+ clear: left;
+ float: left;
+ margin-right: 1em;
+}
+
+img.align-right, .figure.align-right, object.align-right {
+ clear: right;
+ float: right;
+ margin-left: 1em;
+}
+
+img.align-center, .figure.align-center, object.align-center {
+ display: block;
+ margin-left: auto;
+ margin-right: auto;
+}
+
+.align-left {
+ text-align: left;
+}
+
+.align-center {
+ text-align: center;
+}
+
+.align-right {
+ text-align: right;
+}
+
+/* -- sidebars -------------------------------------------------------------- */
+
+div.sidebar {
+ margin: 0 0 0.5em 1em;
+ border: 1px solid #ddb;
+ padding: 7px 7px 0 7px;
+ background-color: #ffe;
+ width: 40%;
+ float: right;
+}
+
+p.sidebar-title {
+ font-weight: bold;
+}
+
+/* -- topics ---------------------------------------------------------------- */
+
+div.topic {
+ border: 1px solid #ccc;
+ padding: 7px 7px 0 7px;
+ margin: 10px 0 10px 0;
+}
+
+p.topic-title {
+ font-size: 1.1em;
+ font-weight: bold;
+ margin-top: 10px;
+}
+
+/* -- admonitions ----------------------------------------------------------- */
+
+div.admonition {
+ margin-top: 10px;
+ margin-bottom: 10px;
+ padding: 7px;
+}
+
+div.admonition dt {
+ font-weight: bold;
+}
+
+div.admonition dl {
+ margin-bottom: 0;
+}
+
+p.admonition-title {
+ margin: 0px 10px 5px 0px;
+ font-weight: bold;
+}
+
+div.body p.centered {
+ text-align: center;
+ margin-top: 25px;
+}
+
+/* -- tables ---------------------------------------------------------------- */
+
+table.docutils {
+ border: 0;
+ border-collapse: collapse;
+}
+
+table.align-center {
+ margin-left: auto;
+ margin-right: auto;
+}
+
+table caption span.caption-number {
+ font-style: italic;
+}
+
+table caption span.caption-text {
+}
+
+table.docutils td, table.docutils th {
+ padding: 1px 8px 1px 5px;
+ border-top: 0;
+ border-left: 0;
+ border-right: 0;
+ border-bottom: 1px solid #aaa;
+}
+
+table.footnote td, table.footnote th {
+ border: 0 !important;
+}
+
+th {
+ text-align: left;
+ padding-right: 5px;
+}
+
+table.citation {
+ border-left: solid 1px gray;
+ margin-left: 1px;
+}
+
+table.citation td {
+ border-bottom: none;
+}
+
+/* -- figures --------------------------------------------------------------- */
+
+div.figure {
+ margin: 0.5em;
+ padding: 0.5em;
+}
+
+div.figure p.caption {
+ padding: 0.3em;
+}
+
+div.figure p.caption span.caption-number {
+ font-style: italic;
+}
+
+div.figure p.caption span.caption-text {
+}
+
+/* -- field list styles ----------------------------------------------------- */
+
+table.field-list td, table.field-list th {
+ border: 0 !important;
+}
+
+.field-list ul {
+ margin: 0;
+ padding-left: 1em;
+}
+
+.field-list p {
+ margin: 0;
+}
+
+.field-name {
+ -moz-hyphens: manual;
+ -ms-hyphens: manual;
+ -webkit-hyphens: manual;
+ hyphens: manual;
+}
+
+/* -- other body styles ----------------------------------------------------- */
+
+ol.arabic {
+ list-style: decimal;
+}
+
+ol.loweralpha {
+ list-style: lower-alpha;
+}
+
+ol.upperalpha {
+ list-style: upper-alpha;
+}
+
+ol.lowerroman {
+ list-style: lower-roman;
+}
+
+ol.upperroman {
+ list-style: upper-roman;
+}
+
+dl {
+ margin-bottom: 15px;
+}
+
+dd p {
+ margin-top: 0px;
+}
+
+dd ul, dd table {
+ margin-bottom: 10px;
+}
+
+dd {
+ margin-top: 3px;
+ margin-bottom: 10px;
+ margin-left: 30px;
+}
+
+dt:target, span.highlighted {
+ background-color: #fbe54e;
+}
+
+rect.highlighted {
+ fill: #fbe54e;
+}
+
+dl.glossary dt {
+ font-weight: bold;
+ font-size: 1.1em;
+}
+
+.optional {
+ font-size: 1.3em;
+}
+
+.sig-paren {
+ font-size: larger;
+}
+
+.versionmodified {
+ font-style: italic;
+}
+
+.system-message {
+ background-color: #fda;
+ padding: 5px;
+ border: 3px solid red;
+}
+
+.footnote:target {
+ background-color: #ffa;
+}
+
+.line-block {
+ display: block;
+ margin-top: 1em;
+ margin-bottom: 1em;
+}
+
+.line-block .line-block {
+ margin-top: 0;
+ margin-bottom: 0;
+ margin-left: 1.5em;
+}
+
+.guilabel, .menuselection {
+ font-family: sans-serif;
+}
+
+.accelerator {
+ text-decoration: underline;
+}
+
+.classifier {
+ font-style: oblique;
+}
+
+abbr, acronym {
+ border-bottom: dotted 1px;
+ cursor: help;
+}
+
+/* -- code displays --------------------------------------------------------- */
+
+pre {
+ overflow: auto;
+ overflow-y: hidden; /* fixes display issues on Chrome browsers */
+}
+
+span.pre {
+ -moz-hyphens: none;
+ -ms-hyphens: none;
+ -webkit-hyphens: none;
+ hyphens: none;
+}
+
+td.linenos pre {
+ padding: 5px 0px;
+ border: 0;
+ background-color: transparent;
+ color: #aaa;
+}
+
+table.highlighttable {
+ margin-left: 0.5em;
+}
+
+table.highlighttable td {
+ padding: 0 0.5em 0 0.5em;
+}
+
+div.code-block-caption {
+ padding: 2px 5px;
+ font-size: small;
+}
+
+div.code-block-caption code {
+ background-color: transparent;
+}
+
+div.code-block-caption + div > div.highlight > pre {
+ margin-top: 0;
+}
+
+div.code-block-caption span.caption-number {
+ padding: 0.1em 0.3em;
+ font-style: italic;
+}
+
+div.code-block-caption span.caption-text {
+}
+
+div.literal-block-wrapper {
+ padding: 1em 1em 0;
+}
+
+div.literal-block-wrapper div.highlight {
+ margin: 0;
+}
+
+code.descname {
+ background-color: transparent;
+ font-weight: bold;
+ font-size: 1.2em;
+}
+
+code.descclassname {
+ background-color: transparent;
+}
+
+code.xref, a code {
+ background-color: transparent;
+ font-weight: bold;
+}
+
+h1 code, h2 code, h3 code, h4 code, h5 code, h6 code {
+ background-color: transparent;
+}
+
+.viewcode-link {
+ float: right;
+}
+
+.viewcode-back {
+ float: right;
+ font-family: sans-serif;
+}
+
+div.viewcode-block:target {
+ margin: -1px -10px;
+ padding: 0 10px;
+}
+
+/* -- math display ---------------------------------------------------------- */
+
+img.math {
+ vertical-align: middle;
+}
+
+div.body div.math p {
+ text-align: center;
+}
+
+span.eqno {
+ float: right;
+}
+
+span.eqno a.headerlink {
+ position: relative;
+ left: 0px;
+ z-index: 1;
+}
+
+div.math:hover a.headerlink {
+ visibility: visible;
+}
+
+/* -- printout stylesheet --------------------------------------------------- */
+
+ at media print {
+ div.document,
+ div.documentwrapper,
+ div.bodywrapper {
+ margin: 0 !important;
+ width: 100%;
+ }
+
+ div.sphinxsidebar,
+ div.related,
+ div.footer,
+ #top-link {
+ display: none;
+ }
+}
\ No newline at end of file
Added: www-releases/trunk/8.0.0/docs/_static/comment-bright.png
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Added: www-releases/trunk/8.0.0/docs/_static/doctools.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/doctools.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/doctools.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/doctools.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,313 @@
+/*
+ * doctools.js
+ * ~~~~~~~~~~~
+ *
+ * Sphinx JavaScript utilities for all documentation.
+ *
+ * :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
+ * :license: BSD, see LICENSE for details.
+ *
+ */
+
+/**
+ * select a different prefix for underscore
+ */
+$u = _.noConflict();
+
+/**
+ * make the code below compatible with browsers without
+ * an installed firebug like debugger
+if (!window.console || !console.firebug) {
+ var names = ["log", "debug", "info", "warn", "error", "assert", "dir",
+ "dirxml", "group", "groupEnd", "time", "timeEnd", "count", "trace",
+ "profile", "profileEnd"];
+ window.console = {};
+ for (var i = 0; i < names.length; ++i)
+ window.console[names[i]] = function() {};
+}
+ */
+
+/**
+ * small helper function to urldecode strings
+ */
+jQuery.urldecode = function(x) {
+ return decodeURIComponent(x).replace(/\+/g, ' ');
+};
+
+/**
+ * small helper function to urlencode strings
+ */
+jQuery.urlencode = encodeURIComponent;
+
+/**
+ * This function returns the parsed url parameters of the
+ * current request. Multiple values per key are supported,
+ * it will always return arrays of strings for the value parts.
+ */
+jQuery.getQueryParameters = function(s) {
+ if (typeof s === 'undefined')
+ s = document.location.search;
+ var parts = s.substr(s.indexOf('?') + 1).split('&');
+ var result = {};
+ for (var i = 0; i < parts.length; i++) {
+ var tmp = parts[i].split('=', 2);
+ var key = jQuery.urldecode(tmp[0]);
+ var value = jQuery.urldecode(tmp[1]);
+ if (key in result)
+ result[key].push(value);
+ else
+ result[key] = [value];
+ }
+ return result;
+};
+
+/**
+ * highlight a given string on a jquery object by wrapping it in
+ * span elements with the given class name.
+ */
+jQuery.fn.highlightText = function(text, className) {
+ function highlight(node, addItems) {
+ if (node.nodeType === 3) {
+ var val = node.nodeValue;
+ var pos = val.toLowerCase().indexOf(text);
+ if (pos >= 0 &&
+ !jQuery(node.parentNode).hasClass(className) &&
+ !jQuery(node.parentNode).hasClass("nohighlight")) {
+ var span;
+ var isInSVG = jQuery(node).closest("body, svg, foreignObject").is("svg");
+ if (isInSVG) {
+ span = document.createElementNS("http://www.w3.org/2000/svg", "tspan");
+ } else {
+ span = document.createElement("span");
+ span.className = className;
+ }
+ span.appendChild(document.createTextNode(val.substr(pos, text.length)));
+ node.parentNode.insertBefore(span, node.parentNode.insertBefore(
+ document.createTextNode(val.substr(pos + text.length)),
+ node.nextSibling));
+ node.nodeValue = val.substr(0, pos);
+ if (isInSVG) {
+ var bbox = span.getBBox();
+ var rect = document.createElementNS("http://www.w3.org/2000/svg", "rect");
+ rect.x.baseVal.value = bbox.x;
+ rect.y.baseVal.value = bbox.y;
+ rect.width.baseVal.value = bbox.width;
+ rect.height.baseVal.value = bbox.height;
+ rect.setAttribute('class', className);
+ var parentOfText = node.parentNode.parentNode;
+ addItems.push({
+ "parent": node.parentNode,
+ "target": rect});
+ }
+ }
+ }
+ else if (!jQuery(node).is("button, select, textarea")) {
+ jQuery.each(node.childNodes, function() {
+ highlight(this, addItems);
+ });
+ }
+ }
+ var addItems = [];
+ var result = this.each(function() {
+ highlight(this, addItems);
+ });
+ for (var i = 0; i < addItems.length; ++i) {
+ jQuery(addItems[i].parent).before(addItems[i].target);
+ }
+ return result;
+};
+
+/*
+ * backward compatibility for jQuery.browser
+ * This will be supported until firefox bug is fixed.
+ */
+if (!jQuery.browser) {
+ jQuery.uaMatch = function(ua) {
+ ua = ua.toLowerCase();
+
+ var match = /(chrome)[ \/]([\w.]+)/.exec(ua) ||
+ /(webkit)[ \/]([\w.]+)/.exec(ua) ||
+ /(opera)(?:.*version|)[ \/]([\w.]+)/.exec(ua) ||
+ /(msie) ([\w.]+)/.exec(ua) ||
+ ua.indexOf("compatible") < 0 && /(mozilla)(?:.*? rv:([\w.]+)|)/.exec(ua) ||
+ [];
+
+ return {
+ browser: match[ 1 ] || "",
+ version: match[ 2 ] || "0"
+ };
+ };
+ jQuery.browser = {};
+ jQuery.browser[jQuery.uaMatch(navigator.userAgent).browser] = true;
+}
+
+/**
+ * Small JavaScript module for the documentation.
+ */
+var Documentation = {
+
+ init : function() {
+ this.fixFirefoxAnchorBug();
+ this.highlightSearchWords();
+ this.initIndexTable();
+
+ },
+
+ /**
+ * i18n support
+ */
+ TRANSLATIONS : {},
+ PLURAL_EXPR : function(n) { return n === 1 ? 0 : 1; },
+ LOCALE : 'unknown',
+
+ // gettext and ngettext don't access this so that the functions
+ // can safely bound to a different name (_ = Documentation.gettext)
+ gettext : function(string) {
+ var translated = Documentation.TRANSLATIONS[string];
+ if (typeof translated === 'undefined')
+ return string;
+ return (typeof translated === 'string') ? translated : translated[0];
+ },
+
+ ngettext : function(singular, plural, n) {
+ var translated = Documentation.TRANSLATIONS[singular];
+ if (typeof translated === 'undefined')
+ return (n == 1) ? singular : plural;
+ return translated[Documentation.PLURALEXPR(n)];
+ },
+
+ addTranslations : function(catalog) {
+ for (var key in catalog.messages)
+ this.TRANSLATIONS[key] = catalog.messages[key];
+ this.PLURAL_EXPR = new Function('n', 'return +(' + catalog.plural_expr + ')');
+ this.LOCALE = catalog.locale;
+ },
+
+ /**
+ * add context elements like header anchor links
+ */
+ addContextElements : function() {
+ $('div[id] > :header:first').each(function() {
+ $('<a class="headerlink">\u00B6</a>').
+ attr('href', '#' + this.id).
+ attr('title', _('Permalink to this headline')).
+ appendTo(this);
+ });
+ $('dt[id]').each(function() {
+ $('<a class="headerlink">\u00B6</a>').
+ attr('href', '#' + this.id).
+ attr('title', _('Permalink to this definition')).
+ appendTo(this);
+ });
+ },
+
+ /**
+ * workaround a firefox stupidity
+ * see: https://bugzilla.mozilla.org/show_bug.cgi?id=645075
+ */
+ fixFirefoxAnchorBug : function() {
+ if (document.location.hash && $.browser.mozilla)
+ window.setTimeout(function() {
+ document.location.href += '';
+ }, 10);
+ },
+
+ /**
+ * highlight the search words provided in the url in the text
+ */
+ highlightSearchWords : function() {
+ var params = $.getQueryParameters();
+ var terms = (params.highlight) ? params.highlight[0].split(/\s+/) : [];
+ if (terms.length) {
+ var body = $('div.body');
+ if (!body.length) {
+ body = $('body');
+ }
+ window.setTimeout(function() {
+ $.each(terms, function() {
+ body.highlightText(this.toLowerCase(), 'highlighted');
+ });
+ }, 10);
+ $('<p class="highlight-link"><a href="javascript:Documentation.' +
+ 'hideSearchWords()">' + _('Hide Search Matches') + '</a></p>')
+ .appendTo($('#searchbox'));
+ }
+ },
+
+ /**
+ * init the domain index toggle buttons
+ */
+ initIndexTable : function() {
+ var togglers = $('img.toggler').click(function() {
+ var src = $(this).attr('src');
+ var idnum = $(this).attr('id').substr(7);
+ $('tr.cg-' + idnum).toggle();
+ if (src.substr(-9) === 'minus.png')
+ $(this).attr('src', src.substr(0, src.length-9) + 'plus.png');
+ else
+ $(this).attr('src', src.substr(0, src.length-8) + 'minus.png');
+ }).css('display', '');
+ if (DOCUMENTATION_OPTIONS.COLLAPSE_INDEX) {
+ togglers.click();
+ }
+ },
+
+ /**
+ * helper function to hide the search marks again
+ */
+ hideSearchWords : function() {
+ $('#searchbox .highlight-link').fadeOut(300);
+ $('span.highlighted').removeClass('highlighted');
+ },
+
+ /**
+ * make the url absolute
+ */
+ makeURL : function(relativeURL) {
+ return DOCUMENTATION_OPTIONS.URL_ROOT + '/' + relativeURL;
+ },
+
+ /**
+ * get the current relative url
+ */
+ getCurrentURL : function() {
+ var path = document.location.pathname;
+ var parts = path.split(/\//);
+ $.each(DOCUMENTATION_OPTIONS.URL_ROOT.split(/\//), function() {
+ if (this === '..')
+ parts.pop();
+ });
+ var url = parts.join('/');
+ return path.substring(url.lastIndexOf('/') + 1, path.length - 1);
+ },
+
+ initOnKeyListeners: function() {
+ $(document).keyup(function(event) {
+ var activeElementType = document.activeElement.tagName;
+ // don't navigate when in search box or textarea
+ if (activeElementType !== 'TEXTAREA' && activeElementType !== 'INPUT' && activeElementType !== 'SELECT') {
+ switch (event.keyCode) {
+ case 37: // left
+ var prevHref = $('link[rel="prev"]').prop('href');
+ if (prevHref) {
+ window.location.href = prevHref;
+ return false;
+ }
+ case 39: // right
+ var nextHref = $('link[rel="next"]').prop('href');
+ if (nextHref) {
+ window.location.href = nextHref;
+ return false;
+ }
+ }
+ }
+ });
+ }
+};
+
+// quick alias for translations
+_ = Documentation.gettext;
+
+$(document).ready(function() {
+ Documentation.init();
+});
\ No newline at end of file
Added: www-releases/trunk/8.0.0/docs/_static/documentation_options.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/documentation_options.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/documentation_options.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/documentation_options.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,9 @@
+var DOCUMENTATION_OPTIONS = {
+ URL_ROOT: document.getElementById("documentation_options").getAttribute('data-url_root'),
+ VERSION: '8',
+ LANGUAGE: 'None',
+ COLLAPSE_INDEX: false,
+ FILE_SUFFIX: '.html',
+ HAS_SOURCE: true,
+ SOURCELINK_SUFFIX: '.txt'
+};
\ No newline at end of file
Added: www-releases/trunk/8.0.0/docs/_static/down-pressed.png
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==============================================================================
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svn:mime-type = application/octet-stream
Added: www-releases/trunk/8.0.0/docs/_static/jquery.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/jquery.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/jquery.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/jquery.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,10253 @@
+/*!
+ * jQuery JavaScript Library v3.2.1
+ * https://jquery.com/
+ *
+ * Includes Sizzle.js
+ * https://sizzlejs.com/
+ *
+ * Copyright JS Foundation and other contributors
+ * Released under the MIT license
+ * https://jquery.org/license
+ *
+ * Date: 2017-09-03T00:14Z
+ */
+( function( global, factory ) {
+
+ "use strict";
+
+ if ( typeof module === "object" && typeof module.exports === "object" ) {
+
+ // For CommonJS and CommonJS-like environments where a proper `window`
+ // is present, execute the factory and get jQuery.
+ // For environments that do not have a `window` with a `document`
+ // (such as Node.js), expose a factory as module.exports.
+ // This accentuates the need for the creation of a real `window`.
+ // e.g. var jQuery = require("jquery")(window);
+ // See ticket #14549 for more info.
+ module.exports = global.document ?
+ factory( global, true ) :
+ function( w ) {
+ if ( !w.document ) {
+ throw new Error( "jQuery requires a window with a document" );
+ }
+ return factory( w );
+ };
+ } else {
+ factory( global );
+ }
+
+// Pass this if window is not defined yet
+} )( typeof window !== "undefined" ? window : this, function( window, noGlobal ) {
+
+// Edge <= 12 - 13+, Firefox <=18 - 45+, IE 10 - 11, Safari 5.1 - 9+, iOS 6 - 9.1
+// throw exceptions when non-strict code (e.g., ASP.NET 4.5) accesses strict mode
+// arguments.callee.caller (trac-13335). But as of jQuery 3.0 (2016), strict mode should be common
+// enough that all such attempts are guarded in a try block.
+
+
+var arr = [];
+
+var document = window.document;
+
+var getProto = Object.getPrototypeOf;
+
+var slice = arr.slice;
+
+var concat = arr.concat;
+
+var push = arr.push;
+
+var indexOf = arr.indexOf;
+
+var class2type = {};
+
+var toString = class2type.toString;
+
+var hasOwn = class2type.hasOwnProperty;
+
+var fnToString = hasOwn.toString;
+
+var ObjectFunctionString = fnToString.call( Object );
+
+var support = {};
+
+
+
+ function DOMEval( code, doc ) {
+ doc = doc || document;
+
+ var script = doc.createElement( "script" );
+
+ script.text = code;
+ doc.head.appendChild( script ).parentNode.removeChild( script );
+ }
+/* global Symbol */
+// Defining this global in .eslintrc.json would create a danger of using the global
+// unguarded in another place, it seems safer to define global only for this module
+
+
+
+var
+ version = "3.2.1",
+
+ // Define a local copy of jQuery
+ jQuery = function( selector, context ) {
+
+ // The jQuery object is actually just the init constructor 'enhanced'
+ // Need init if jQuery is called (just allow error to be thrown if not included)
+ return new jQuery.fn.init( selector, context );
+ },
+
+ // Support: Android <=4.0 only
+ // Make sure we trim BOM and NBSP
+ rtrim = /^[\s\uFEFF\xA0]+|[\s\uFEFF\xA0]+$/g,
+
+ // Matches dashed string for camelizing
+ rmsPrefix = /^-ms-/,
+ rdashAlpha = /-([a-z])/g,
+
+ // Used by jQuery.camelCase as callback to replace()
+ fcamelCase = function( all, letter ) {
+ return letter.toUpperCase();
+ };
+
+jQuery.fn = jQuery.prototype = {
+
+ // The current version of jQuery being used
+ jquery: version,
+
+ constructor: jQuery,
+
+ // The default length of a jQuery object is 0
+ length: 0,
+
+ toArray: function() {
+ return slice.call( this );
+ },
+
+ // Get the Nth element in the matched element set OR
+ // Get the whole matched element set as a clean array
+ get: function( num ) {
+
+ // Return all the elements in a clean array
+ if ( num == null ) {
+ return slice.call( this );
+ }
+
+ // Return just the one element from the set
+ return num < 0 ? this[ num + this.length ] : this[ num ];
+ },
+
+ // Take an array of elements and push it onto the stack
+ // (returning the new matched element set)
+ pushStack: function( elems ) {
+
+ // Build a new jQuery matched element set
+ var ret = jQuery.merge( this.constructor(), elems );
+
+ // Add the old object onto the stack (as a reference)
+ ret.prevObject = this;
+
+ // Return the newly-formed element set
+ return ret;
+ },
+
+ // Execute a callback for every element in the matched set.
+ each: function( callback ) {
+ return jQuery.each( this, callback );
+ },
+
+ map: function( callback ) {
+ return this.pushStack( jQuery.map( this, function( elem, i ) {
+ return callback.call( elem, i, elem );
+ } ) );
+ },
+
+ slice: function() {
+ return this.pushStack( slice.apply( this, arguments ) );
+ },
+
+ first: function() {
+ return this.eq( 0 );
+ },
+
+ last: function() {
+ return this.eq( -1 );
+ },
+
+ eq: function( i ) {
+ var len = this.length,
+ j = +i + ( i < 0 ? len : 0 );
+ return this.pushStack( j >= 0 && j < len ? [ this[ j ] ] : [] );
+ },
+
+ end: function() {
+ return this.prevObject || this.constructor();
+ },
+
+ // For internal use only.
+ // Behaves like an Array's method, not like a jQuery method.
+ push: push,
+ sort: arr.sort,
+ splice: arr.splice
+};
+
+jQuery.extend = jQuery.fn.extend = function() {
+ var options, name, src, copy, copyIsArray, clone,
+ target = arguments[ 0 ] || {},
+ i = 1,
+ length = arguments.length,
+ deep = false;
+
+ // Handle a deep copy situation
+ if ( typeof target === "boolean" ) {
+ deep = target;
+
+ // Skip the boolean and the target
+ target = arguments[ i ] || {};
+ i++;
+ }
+
+ // Handle case when target is a string or something (possible in deep copy)
+ if ( typeof target !== "object" && !jQuery.isFunction( target ) ) {
+ target = {};
+ }
+
+ // Extend jQuery itself if only one argument is passed
+ if ( i === length ) {
+ target = this;
+ i--;
+ }
+
+ for ( ; i < length; i++ ) {
+
+ // Only deal with non-null/undefined values
+ if ( ( options = arguments[ i ] ) != null ) {
+
+ // Extend the base object
+ for ( name in options ) {
+ src = target[ name ];
+ copy = options[ name ];
+
+ // Prevent never-ending loop
+ if ( target === copy ) {
+ continue;
+ }
+
+ // Recurse if we're merging plain objects or arrays
+ if ( deep && copy && ( jQuery.isPlainObject( copy ) ||
+ ( copyIsArray = Array.isArray( copy ) ) ) ) {
+
+ if ( copyIsArray ) {
+ copyIsArray = false;
+ clone = src && Array.isArray( src ) ? src : [];
+
+ } else {
+ clone = src && jQuery.isPlainObject( src ) ? src : {};
+ }
+
+ // Never move original objects, clone them
+ target[ name ] = jQuery.extend( deep, clone, copy );
+
+ // Don't bring in undefined values
+ } else if ( copy !== undefined ) {
+ target[ name ] = copy;
+ }
+ }
+ }
+ }
+
+ // Return the modified object
+ return target;
+};
+
+jQuery.extend( {
+
+ // Unique for each copy of jQuery on the page
+ expando: "jQuery" + ( version + Math.random() ).replace( /\D/g, "" ),
+
+ // Assume jQuery is ready without the ready module
+ isReady: true,
+
+ error: function( msg ) {
+ throw new Error( msg );
+ },
+
+ noop: function() {},
+
+ isFunction: function( obj ) {
+ return jQuery.type( obj ) === "function";
+ },
+
+ isWindow: function( obj ) {
+ return obj != null && obj === obj.window;
+ },
+
+ isNumeric: function( obj ) {
+
+ // As of jQuery 3.0, isNumeric is limited to
+ // strings and numbers (primitives or objects)
+ // that can be coerced to finite numbers (gh-2662)
+ var type = jQuery.type( obj );
+ return ( type === "number" || type === "string" ) &&
+
+ // parseFloat NaNs numeric-cast false positives ("")
+ // ...but misinterprets leading-number strings, particularly hex literals ("0x...")
+ // subtraction forces infinities to NaN
+ !isNaN( obj - parseFloat( obj ) );
+ },
+
+ isPlainObject: function( obj ) {
+ var proto, Ctor;
+
+ // Detect obvious negatives
+ // Use toString instead of jQuery.type to catch host objects
+ if ( !obj || toString.call( obj ) !== "[object Object]" ) {
+ return false;
+ }
+
+ proto = getProto( obj );
+
+ // Objects with no prototype (e.g., `Object.create( null )`) are plain
+ if ( !proto ) {
+ return true;
+ }
+
+ // Objects with prototype are plain iff they were constructed by a global Object function
+ Ctor = hasOwn.call( proto, "constructor" ) && proto.constructor;
+ return typeof Ctor === "function" && fnToString.call( Ctor ) === ObjectFunctionString;
+ },
+
+ isEmptyObject: function( obj ) {
+
+ /* eslint-disable no-unused-vars */
+ // See https://github.com/eslint/eslint/issues/6125
+ var name;
+
+ for ( name in obj ) {
+ return false;
+ }
+ return true;
+ },
+
+ type: function( obj ) {
+ if ( obj == null ) {
+ return obj + "";
+ }
+
+ // Support: Android <=2.3 only (functionish RegExp)
+ return typeof obj === "object" || typeof obj === "function" ?
+ class2type[ toString.call( obj ) ] || "object" :
+ typeof obj;
+ },
+
+ // Evaluates a script in a global context
+ globalEval: function( code ) {
+ DOMEval( code );
+ },
+
+ // Convert dashed to camelCase; used by the css and data modules
+ // Support: IE <=9 - 11, Edge 12 - 13
+ // Microsoft forgot to hump their vendor prefix (#9572)
+ camelCase: function( string ) {
+ return string.replace( rmsPrefix, "ms-" ).replace( rdashAlpha, fcamelCase );
+ },
+
+ each: function( obj, callback ) {
+ var length, i = 0;
+
+ if ( isArrayLike( obj ) ) {
+ length = obj.length;
+ for ( ; i < length; i++ ) {
+ if ( callback.call( obj[ i ], i, obj[ i ] ) === false ) {
+ break;
+ }
+ }
+ } else {
+ for ( i in obj ) {
+ if ( callback.call( obj[ i ], i, obj[ i ] ) === false ) {
+ break;
+ }
+ }
+ }
+
+ return obj;
+ },
+
+ // Support: Android <=4.0 only
+ trim: function( text ) {
+ return text == null ?
+ "" :
+ ( text + "" ).replace( rtrim, "" );
+ },
+
+ // results is for internal usage only
+ makeArray: function( arr, results ) {
+ var ret = results || [];
+
+ if ( arr != null ) {
+ if ( isArrayLike( Object( arr ) ) ) {
+ jQuery.merge( ret,
+ typeof arr === "string" ?
+ [ arr ] : arr
+ );
+ } else {
+ push.call( ret, arr );
+ }
+ }
+
+ return ret;
+ },
+
+ inArray: function( elem, arr, i ) {
+ return arr == null ? -1 : indexOf.call( arr, elem, i );
+ },
+
+ // Support: Android <=4.0 only, PhantomJS 1 only
+ // push.apply(_, arraylike) throws on ancient WebKit
+ merge: function( first, second ) {
+ var len = +second.length,
+ j = 0,
+ i = first.length;
+
+ for ( ; j < len; j++ ) {
+ first[ i++ ] = second[ j ];
+ }
+
+ first.length = i;
+
+ return first;
+ },
+
+ grep: function( elems, callback, invert ) {
+ var callbackInverse,
+ matches = [],
+ i = 0,
+ length = elems.length,
+ callbackExpect = !invert;
+
+ // Go through the array, only saving the items
+ // that pass the validator function
+ for ( ; i < length; i++ ) {
+ callbackInverse = !callback( elems[ i ], i );
+ if ( callbackInverse !== callbackExpect ) {
+ matches.push( elems[ i ] );
+ }
+ }
+
+ return matches;
+ },
+
+ // arg is for internal usage only
+ map: function( elems, callback, arg ) {
+ var length, value,
+ i = 0,
+ ret = [];
+
+ // Go through the array, translating each of the items to their new values
+ if ( isArrayLike( elems ) ) {
+ length = elems.length;
+ for ( ; i < length; i++ ) {
+ value = callback( elems[ i ], i, arg );
+
+ if ( value != null ) {
+ ret.push( value );
+ }
+ }
+
+ // Go through every key on the object,
+ } else {
+ for ( i in elems ) {
+ value = callback( elems[ i ], i, arg );
+
+ if ( value != null ) {
+ ret.push( value );
+ }
+ }
+ }
+
+ // Flatten any nested arrays
+ return concat.apply( [], ret );
+ },
+
+ // A global GUID counter for objects
+ guid: 1,
+
+ // Bind a function to a context, optionally partially applying any
+ // arguments.
+ proxy: function( fn, context ) {
+ var tmp, args, proxy;
+
+ if ( typeof context === "string" ) {
+ tmp = fn[ context ];
+ context = fn;
+ fn = tmp;
+ }
+
+ // Quick check to determine if target is callable, in the spec
+ // this throws a TypeError, but we will just return undefined.
+ if ( !jQuery.isFunction( fn ) ) {
+ return undefined;
+ }
+
+ // Simulated bind
+ args = slice.call( arguments, 2 );
+ proxy = function() {
+ return fn.apply( context || this, args.concat( slice.call( arguments ) ) );
+ };
+
+ // Set the guid of unique handler to the same of original handler, so it can be removed
+ proxy.guid = fn.guid = fn.guid || jQuery.guid++;
+
+ return proxy;
+ },
+
+ now: Date.now,
+
+ // jQuery.support is not used in Core but other projects attach their
+ // properties to it so it needs to exist.
+ support: support
+} );
+
+if ( typeof Symbol === "function" ) {
+ jQuery.fn[ Symbol.iterator ] = arr[ Symbol.iterator ];
+}
+
+// Populate the class2type map
+jQuery.each( "Boolean Number String Function Array Date RegExp Object Error Symbol".split( " " ),
+function( i, name ) {
+ class2type[ "[object " + name + "]" ] = name.toLowerCase();
+} );
+
+function isArrayLike( obj ) {
+
+ // Support: real iOS 8.2 only (not reproducible in simulator)
+ // `in` check used to prevent JIT error (gh-2145)
+ // hasOwn isn't used here due to false negatives
+ // regarding Nodelist length in IE
+ var length = !!obj && "length" in obj && obj.length,
+ type = jQuery.type( obj );
+
+ if ( type === "function" || jQuery.isWindow( obj ) ) {
+ return false;
+ }
+
+ return type === "array" || length === 0 ||
+ typeof length === "number" && length > 0 && ( length - 1 ) in obj;
+}
+var Sizzle =
+/*!
+ * Sizzle CSS Selector Engine v2.3.3
+ * https://sizzlejs.com/
+ *
+ * Copyright jQuery Foundation and other contributors
+ * Released under the MIT license
+ * http://jquery.org/license
+ *
+ * Date: 2016-08-08
+ */
+(function( window ) {
+
+var i,
+ support,
+ Expr,
+ getText,
+ isXML,
+ tokenize,
+ compile,
+ select,
+ outermostContext,
+ sortInput,
+ hasDuplicate,
+
+ // Local document vars
+ setDocument,
+ document,
+ docElem,
+ documentIsHTML,
+ rbuggyQSA,
+ rbuggyMatches,
+ matches,
+ contains,
+
+ // Instance-specific data
+ expando = "sizzle" + 1 * new Date(),
+ preferredDoc = window.document,
+ dirruns = 0,
+ done = 0,
+ classCache = createCache(),
+ tokenCache = createCache(),
+ compilerCache = createCache(),
+ sortOrder = function( a, b ) {
+ if ( a === b ) {
+ hasDuplicate = true;
+ }
+ return 0;
+ },
+
+ // Instance methods
+ hasOwn = ({}).hasOwnProperty,
+ arr = [],
+ pop = arr.pop,
+ push_native = arr.push,
+ push = arr.push,
+ slice = arr.slice,
+ // Use a stripped-down indexOf as it's faster than native
+ // https://jsperf.com/thor-indexof-vs-for/5
+ indexOf = function( list, elem ) {
+ var i = 0,
+ len = list.length;
+ for ( ; i < len; i++ ) {
+ if ( list[i] === elem ) {
+ return i;
+ }
+ }
+ return -1;
+ },
+
+ booleans = "checked|selected|async|autofocus|autoplay|controls|defer|disabled|hidden|ismap|loop|multiple|open|readonly|required|scoped",
+
+ // Regular expressions
+
+ // http://www.w3.org/TR/css3-selectors/#whitespace
+ whitespace = "[\\x20\\t\\r\\n\\f]",
+
+ // http://www.w3.org/TR/CSS21/syndata.html#value-def-identifier
+ identifier = "(?:\\\\.|[\\w-]|[^\0-\\xa0])+",
+
+ // Attribute selectors: http://www.w3.org/TR/selectors/#attribute-selectors
+ attributes = "\\[" + whitespace + "*(" + identifier + ")(?:" + whitespace +
+ // Operator (capture 2)
+ "*([*^$|!~]?=)" + whitespace +
+ // "Attribute values must be CSS identifiers [capture 5] or strings [capture 3 or capture 4]"
+ "*(?:'((?:\\\\.|[^\\\\'])*)'|\"((?:\\\\.|[^\\\\\"])*)\"|(" + identifier + "))|)" + whitespace +
+ "*\\]",
+
+ pseudos = ":(" + identifier + ")(?:\\((" +
+ // To reduce the number of selectors needing tokenize in the preFilter, prefer arguments:
+ // 1. quoted (capture 3; capture 4 or capture 5)
+ "('((?:\\\\.|[^\\\\'])*)'|\"((?:\\\\.|[^\\\\\"])*)\")|" +
+ // 2. simple (capture 6)
+ "((?:\\\\.|[^\\\\()[\\]]|" + attributes + ")*)|" +
+ // 3. anything else (capture 2)
+ ".*" +
+ ")\\)|)",
+
+ // Leading and non-escaped trailing whitespace, capturing some non-whitespace characters preceding the latter
+ rwhitespace = new RegExp( whitespace + "+", "g" ),
+ rtrim = new RegExp( "^" + whitespace + "+|((?:^|[^\\\\])(?:\\\\.)*)" + whitespace + "+$", "g" ),
+
+ rcomma = new RegExp( "^" + whitespace + "*," + whitespace + "*" ),
+ rcombinators = new RegExp( "^" + whitespace + "*([>+~]|" + whitespace + ")" + whitespace + "*" ),
+
+ rattributeQuotes = new RegExp( "=" + whitespace + "*([^\\]'\"]*?)" + whitespace + "*\\]", "g" ),
+
+ rpseudo = new RegExp( pseudos ),
+ ridentifier = new RegExp( "^" + identifier + "$" ),
+
+ matchExpr = {
+ "ID": new RegExp( "^#(" + identifier + ")" ),
+ "CLASS": new RegExp( "^\\.(" + identifier + ")" ),
+ "TAG": new RegExp( "^(" + identifier + "|[*])" ),
+ "ATTR": new RegExp( "^" + attributes ),
+ "PSEUDO": new RegExp( "^" + pseudos ),
+ "CHILD": new RegExp( "^:(only|first|last|nth|nth-last)-(child|of-type)(?:\\(" + whitespace +
+ "*(even|odd|(([+-]|)(\\d*)n|)" + whitespace + "*(?:([+-]|)" + whitespace +
+ "*(\\d+)|))" + whitespace + "*\\)|)", "i" ),
+ "bool": new RegExp( "^(?:" + booleans + ")$", "i" ),
+ // For use in libraries implementing .is()
+ // We use this for POS matching in `select`
+ "needsContext": new RegExp( "^" + whitespace + "*[>+~]|:(even|odd|eq|gt|lt|nth|first|last)(?:\\(" +
+ whitespace + "*((?:-\\d)?\\d*)" + whitespace + "*\\)|)(?=[^-]|$)", "i" )
+ },
+
+ rinputs = /^(?:input|select|textarea|button)$/i,
+ rheader = /^h\d$/i,
+
+ rnative = /^[^{]+\{\s*\[native \w/,
+
+ // Easily-parseable/retrievable ID or TAG or CLASS selectors
+ rquickExpr = /^(?:#([\w-]+)|(\w+)|\.([\w-]+))$/,
+
+ rsibling = /[+~]/,
+
+ // CSS escapes
+ // http://www.w3.org/TR/CSS21/syndata.html#escaped-characters
+ runescape = new RegExp( "\\\\([\\da-f]{1,6}" + whitespace + "?|(" + whitespace + ")|.)", "ig" ),
+ funescape = function( _, escaped, escapedWhitespace ) {
+ var high = "0x" + escaped - 0x10000;
+ // NaN means non-codepoint
+ // Support: Firefox<24
+ // Workaround erroneous numeric interpretation of +"0x"
+ return high !== high || escapedWhitespace ?
+ escaped :
+ high < 0 ?
+ // BMP codepoint
+ String.fromCharCode( high + 0x10000 ) :
+ // Supplemental Plane codepoint (surrogate pair)
+ String.fromCharCode( high >> 10 | 0xD800, high & 0x3FF | 0xDC00 );
+ },
+
+ // CSS string/identifier serialization
+ // https://drafts.csswg.org/cssom/#common-serializing-idioms
+ rcssescape = /([\0-\x1f\x7f]|^-?\d)|^-$|[^\0-\x1f\x7f-\uFFFF\w-]/g,
+ fcssescape = function( ch, asCodePoint ) {
+ if ( asCodePoint ) {
+
+ // U+0000 NULL becomes U+FFFD REPLACEMENT CHARACTER
+ if ( ch === "\0" ) {
+ return "\uFFFD";
+ }
+
+ // Control characters and (dependent upon position) numbers get escaped as code points
+ return ch.slice( 0, -1 ) + "\\" + ch.charCodeAt( ch.length - 1 ).toString( 16 ) + " ";
+ }
+
+ // Other potentially-special ASCII characters get backslash-escaped
+ return "\\" + ch;
+ },
+
+ // Used for iframes
+ // See setDocument()
+ // Removing the function wrapper causes a "Permission Denied"
+ // error in IE
+ unloadHandler = function() {
+ setDocument();
+ },
+
+ disabledAncestor = addCombinator(
+ function( elem ) {
+ return elem.disabled === true && ("form" in elem || "label" in elem);
+ },
+ { dir: "parentNode", next: "legend" }
+ );
+
+// Optimize for push.apply( _, NodeList )
+try {
+ push.apply(
+ (arr = slice.call( preferredDoc.childNodes )),
+ preferredDoc.childNodes
+ );
+ // Support: Android<4.0
+ // Detect silently failing push.apply
+ arr[ preferredDoc.childNodes.length ].nodeType;
+} catch ( e ) {
+ push = { apply: arr.length ?
+
+ // Leverage slice if possible
+ function( target, els ) {
+ push_native.apply( target, slice.call(els) );
+ } :
+
+ // Support: IE<9
+ // Otherwise append directly
+ function( target, els ) {
+ var j = target.length,
+ i = 0;
+ // Can't trust NodeList.length
+ while ( (target[j++] = els[i++]) ) {}
+ target.length = j - 1;
+ }
+ };
+}
+
+function Sizzle( selector, context, results, seed ) {
+ var m, i, elem, nid, match, groups, newSelector,
+ newContext = context && context.ownerDocument,
+
+ // nodeType defaults to 9, since context defaults to document
+ nodeType = context ? context.nodeType : 9;
+
+ results = results || [];
+
+ // Return early from calls with invalid selector or context
+ if ( typeof selector !== "string" || !selector ||
+ nodeType !== 1 && nodeType !== 9 && nodeType !== 11 ) {
+
+ return results;
+ }
+
+ // Try to shortcut find operations (as opposed to filters) in HTML documents
+ if ( !seed ) {
+
+ if ( ( context ? context.ownerDocument || context : preferredDoc ) !== document ) {
+ setDocument( context );
+ }
+ context = context || document;
+
+ if ( documentIsHTML ) {
+
+ // If the selector is sufficiently simple, try using a "get*By*" DOM method
+ // (excepting DocumentFragment context, where the methods don't exist)
+ if ( nodeType !== 11 && (match = rquickExpr.exec( selector )) ) {
+
+ // ID selector
+ if ( (m = match[1]) ) {
+
+ // Document context
+ if ( nodeType === 9 ) {
+ if ( (elem = context.getElementById( m )) ) {
+
+ // Support: IE, Opera, Webkit
+ // TODO: identify versions
+ // getElementById can match elements by name instead of ID
+ if ( elem.id === m ) {
+ results.push( elem );
+ return results;
+ }
+ } else {
+ return results;
+ }
+
+ // Element context
+ } else {
+
+ // Support: IE, Opera, Webkit
+ // TODO: identify versions
+ // getElementById can match elements by name instead of ID
+ if ( newContext && (elem = newContext.getElementById( m )) &&
+ contains( context, elem ) &&
+ elem.id === m ) {
+
+ results.push( elem );
+ return results;
+ }
+ }
+
+ // Type selector
+ } else if ( match[2] ) {
+ push.apply( results, context.getElementsByTagName( selector ) );
+ return results;
+
+ // Class selector
+ } else if ( (m = match[3]) && support.getElementsByClassName &&
+ context.getElementsByClassName ) {
+
+ push.apply( results, context.getElementsByClassName( m ) );
+ return results;
+ }
+ }
+
+ // Take advantage of querySelectorAll
+ if ( support.qsa &&
+ !compilerCache[ selector + " " ] &&
+ (!rbuggyQSA || !rbuggyQSA.test( selector )) ) {
+
+ if ( nodeType !== 1 ) {
+ newContext = context;
+ newSelector = selector;
+
+ // qSA looks outside Element context, which is not what we want
+ // Thanks to Andrew Dupont for this workaround technique
+ // Support: IE <=8
+ // Exclude object elements
+ } else if ( context.nodeName.toLowerCase() !== "object" ) {
+
+ // Capture the context ID, setting it first if necessary
+ if ( (nid = context.getAttribute( "id" )) ) {
+ nid = nid.replace( rcssescape, fcssescape );
+ } else {
+ context.setAttribute( "id", (nid = expando) );
+ }
+
+ // Prefix every selector in the list
+ groups = tokenize( selector );
+ i = groups.length;
+ while ( i-- ) {
+ groups[i] = "#" + nid + " " + toSelector( groups[i] );
+ }
+ newSelector = groups.join( "," );
+
+ // Expand context for sibling selectors
+ newContext = rsibling.test( selector ) && testContext( context.parentNode ) ||
+ context;
+ }
+
+ if ( newSelector ) {
+ try {
+ push.apply( results,
+ newContext.querySelectorAll( newSelector )
+ );
+ return results;
+ } catch ( qsaError ) {
+ } finally {
+ if ( nid === expando ) {
+ context.removeAttribute( "id" );
+ }
+ }
+ }
+ }
+ }
+ }
+
+ // All others
+ return select( selector.replace( rtrim, "$1" ), context, results, seed );
+}
+
+/**
+ * Create key-value caches of limited size
+ * @returns {function(string, object)} Returns the Object data after storing it on itself with
+ * property name the (space-suffixed) string and (if the cache is larger than Expr.cacheLength)
+ * deleting the oldest entry
+ */
+function createCache() {
+ var keys = [];
+
+ function cache( key, value ) {
+ // Use (key + " ") to avoid collision with native prototype properties (see Issue #157)
+ if ( keys.push( key + " " ) > Expr.cacheLength ) {
+ // Only keep the most recent entries
+ delete cache[ keys.shift() ];
+ }
+ return (cache[ key + " " ] = value);
+ }
+ return cache;
+}
+
+/**
+ * Mark a function for special use by Sizzle
+ * @param {Function} fn The function to mark
+ */
+function markFunction( fn ) {
+ fn[ expando ] = true;
+ return fn;
+}
+
+/**
+ * Support testing using an element
+ * @param {Function} fn Passed the created element and returns a boolean result
+ */
+function assert( fn ) {
+ var el = document.createElement("fieldset");
+
+ try {
+ return !!fn( el );
+ } catch (e) {
+ return false;
+ } finally {
+ // Remove from its parent by default
+ if ( el.parentNode ) {
+ el.parentNode.removeChild( el );
+ }
+ // release memory in IE
+ el = null;
+ }
+}
+
+/**
+ * Adds the same handler for all of the specified attrs
+ * @param {String} attrs Pipe-separated list of attributes
+ * @param {Function} handler The method that will be applied
+ */
+function addHandle( attrs, handler ) {
+ var arr = attrs.split("|"),
+ i = arr.length;
+
+ while ( i-- ) {
+ Expr.attrHandle[ arr[i] ] = handler;
+ }
+}
+
+/**
+ * Checks document order of two siblings
+ * @param {Element} a
+ * @param {Element} b
+ * @returns {Number} Returns less than 0 if a precedes b, greater than 0 if a follows b
+ */
+function siblingCheck( a, b ) {
+ var cur = b && a,
+ diff = cur && a.nodeType === 1 && b.nodeType === 1 &&
+ a.sourceIndex - b.sourceIndex;
+
+ // Use IE sourceIndex if available on both nodes
+ if ( diff ) {
+ return diff;
+ }
+
+ // Check if b follows a
+ if ( cur ) {
+ while ( (cur = cur.nextSibling) ) {
+ if ( cur === b ) {
+ return -1;
+ }
+ }
+ }
+
+ return a ? 1 : -1;
+}
+
+/**
+ * Returns a function to use in pseudos for input types
+ * @param {String} type
+ */
+function createInputPseudo( type ) {
+ return function( elem ) {
+ var name = elem.nodeName.toLowerCase();
+ return name === "input" && elem.type === type;
+ };
+}
+
+/**
+ * Returns a function to use in pseudos for buttons
+ * @param {String} type
+ */
+function createButtonPseudo( type ) {
+ return function( elem ) {
+ var name = elem.nodeName.toLowerCase();
+ return (name === "input" || name === "button") && elem.type === type;
+ };
+}
+
+/**
+ * Returns a function to use in pseudos for :enabled/:disabled
+ * @param {Boolean} disabled true for :disabled; false for :enabled
+ */
+function createDisabledPseudo( disabled ) {
+
+ // Known :disabled false positives: fieldset[disabled] > legend:nth-of-type(n+2) :can-disable
+ return function( elem ) {
+
+ // Only certain elements can match :enabled or :disabled
+ // https://html.spec.whatwg.org/multipage/scripting.html#selector-enabled
+ // https://html.spec.whatwg.org/multipage/scripting.html#selector-disabled
+ if ( "form" in elem ) {
+
+ // Check for inherited disabledness on relevant non-disabled elements:
+ // * listed form-associated elements in a disabled fieldset
+ // https://html.spec.whatwg.org/multipage/forms.html#category-listed
+ // https://html.spec.whatwg.org/multipage/forms.html#concept-fe-disabled
+ // * option elements in a disabled optgroup
+ // https://html.spec.whatwg.org/multipage/forms.html#concept-option-disabled
+ // All such elements have a "form" property.
+ if ( elem.parentNode && elem.disabled === false ) {
+
+ // Option elements defer to a parent optgroup if present
+ if ( "label" in elem ) {
+ if ( "label" in elem.parentNode ) {
+ return elem.parentNode.disabled === disabled;
+ } else {
+ return elem.disabled === disabled;
+ }
+ }
+
+ // Support: IE 6 - 11
+ // Use the isDisabled shortcut property to check for disabled fieldset ancestors
+ return elem.isDisabled === disabled ||
+
+ // Where there is no isDisabled, check manually
+ /* jshint -W018 */
+ elem.isDisabled !== !disabled &&
+ disabledAncestor( elem ) === disabled;
+ }
+
+ return elem.disabled === disabled;
+
+ // Try to winnow out elements that can't be disabled before trusting the disabled property.
+ // Some victims get caught in our net (label, legend, menu, track), but it shouldn't
+ // even exist on them, let alone have a boolean value.
+ } else if ( "label" in elem ) {
+ return elem.disabled === disabled;
+ }
+
+ // Remaining elements are neither :enabled nor :disabled
+ return false;
+ };
+}
+
+/**
+ * Returns a function to use in pseudos for positionals
+ * @param {Function} fn
+ */
+function createPositionalPseudo( fn ) {
+ return markFunction(function( argument ) {
+ argument = +argument;
+ return markFunction(function( seed, matches ) {
+ var j,
+ matchIndexes = fn( [], seed.length, argument ),
+ i = matchIndexes.length;
+
+ // Match elements found at the specified indexes
+ while ( i-- ) {
+ if ( seed[ (j = matchIndexes[i]) ] ) {
+ seed[j] = !(matches[j] = seed[j]);
+ }
+ }
+ });
+ });
+}
+
+/**
+ * Checks a node for validity as a Sizzle context
+ * @param {Element|Object=} context
+ * @returns {Element|Object|Boolean} The input node if acceptable, otherwise a falsy value
+ */
+function testContext( context ) {
+ return context && typeof context.getElementsByTagName !== "undefined" && context;
+}
+
+// Expose support vars for convenience
+support = Sizzle.support = {};
+
+/**
+ * Detects XML nodes
+ * @param {Element|Object} elem An element or a document
+ * @returns {Boolean} True iff elem is a non-HTML XML node
+ */
+isXML = Sizzle.isXML = function( elem ) {
+ // documentElement is verified for cases where it doesn't yet exist
+ // (such as loading iframes in IE - #4833)
+ var documentElement = elem && (elem.ownerDocument || elem).documentElement;
+ return documentElement ? documentElement.nodeName !== "HTML" : false;
+};
+
+/**
+ * Sets document-related variables once based on the current document
+ * @param {Element|Object} [doc] An element or document object to use to set the document
+ * @returns {Object} Returns the current document
+ */
+setDocument = Sizzle.setDocument = function( node ) {
+ var hasCompare, subWindow,
+ doc = node ? node.ownerDocument || node : preferredDoc;
+
+ // Return early if doc is invalid or already selected
+ if ( doc === document || doc.nodeType !== 9 || !doc.documentElement ) {
+ return document;
+ }
+
+ // Update global variables
+ document = doc;
+ docElem = document.documentElement;
+ documentIsHTML = !isXML( document );
+
+ // Support: IE 9-11, Edge
+ // Accessing iframe documents after unload throws "permission denied" errors (jQuery #13936)
+ if ( preferredDoc !== document &&
+ (subWindow = document.defaultView) && subWindow.top !== subWindow ) {
+
+ // Support: IE 11, Edge
+ if ( subWindow.addEventListener ) {
+ subWindow.addEventListener( "unload", unloadHandler, false );
+
+ // Support: IE 9 - 10 only
+ } else if ( subWindow.attachEvent ) {
+ subWindow.attachEvent( "onunload", unloadHandler );
+ }
+ }
+
+ /* Attributes
+ ---------------------------------------------------------------------- */
+
+ // Support: IE<8
+ // Verify that getAttribute really returns attributes and not properties
+ // (excepting IE8 booleans)
+ support.attributes = assert(function( el ) {
+ el.className = "i";
+ return !el.getAttribute("className");
+ });
+
+ /* getElement(s)By*
+ ---------------------------------------------------------------------- */
+
+ // Check if getElementsByTagName("*") returns only elements
+ support.getElementsByTagName = assert(function( el ) {
+ el.appendChild( document.createComment("") );
+ return !el.getElementsByTagName("*").length;
+ });
+
+ // Support: IE<9
+ support.getElementsByClassName = rnative.test( document.getElementsByClassName );
+
+ // Support: IE<10
+ // Check if getElementById returns elements by name
+ // The broken getElementById methods don't pick up programmatically-set names,
+ // so use a roundabout getElementsByName test
+ support.getById = assert(function( el ) {
+ docElem.appendChild( el ).id = expando;
+ return !document.getElementsByName || !document.getElementsByName( expando ).length;
+ });
+
+ // ID filter and find
+ if ( support.getById ) {
+ Expr.filter["ID"] = function( id ) {
+ var attrId = id.replace( runescape, funescape );
+ return function( elem ) {
+ return elem.getAttribute("id") === attrId;
+ };
+ };
+ Expr.find["ID"] = function( id, context ) {
+ if ( typeof context.getElementById !== "undefined" && documentIsHTML ) {
+ var elem = context.getElementById( id );
+ return elem ? [ elem ] : [];
+ }
+ };
+ } else {
+ Expr.filter["ID"] = function( id ) {
+ var attrId = id.replace( runescape, funescape );
+ return function( elem ) {
+ var node = typeof elem.getAttributeNode !== "undefined" &&
+ elem.getAttributeNode("id");
+ return node && node.value === attrId;
+ };
+ };
+
+ // Support: IE 6 - 7 only
+ // getElementById is not reliable as a find shortcut
+ Expr.find["ID"] = function( id, context ) {
+ if ( typeof context.getElementById !== "undefined" && documentIsHTML ) {
+ var node, i, elems,
+ elem = context.getElementById( id );
+
+ if ( elem ) {
+
+ // Verify the id attribute
+ node = elem.getAttributeNode("id");
+ if ( node && node.value === id ) {
+ return [ elem ];
+ }
+
+ // Fall back on getElementsByName
+ elems = context.getElementsByName( id );
+ i = 0;
+ while ( (elem = elems[i++]) ) {
+ node = elem.getAttributeNode("id");
+ if ( node && node.value === id ) {
+ return [ elem ];
+ }
+ }
+ }
+
+ return [];
+ }
+ };
+ }
+
+ // Tag
+ Expr.find["TAG"] = support.getElementsByTagName ?
+ function( tag, context ) {
+ if ( typeof context.getElementsByTagName !== "undefined" ) {
+ return context.getElementsByTagName( tag );
+
+ // DocumentFragment nodes don't have gEBTN
+ } else if ( support.qsa ) {
+ return context.querySelectorAll( tag );
+ }
+ } :
+
+ function( tag, context ) {
+ var elem,
+ tmp = [],
+ i = 0,
+ // By happy coincidence, a (broken) gEBTN appears on DocumentFragment nodes too
+ results = context.getElementsByTagName( tag );
+
+ // Filter out possible comments
+ if ( tag === "*" ) {
+ while ( (elem = results[i++]) ) {
+ if ( elem.nodeType === 1 ) {
+ tmp.push( elem );
+ }
+ }
+
+ return tmp;
+ }
+ return results;
+ };
+
+ // Class
+ Expr.find["CLASS"] = support.getElementsByClassName && function( className, context ) {
+ if ( typeof context.getElementsByClassName !== "undefined" && documentIsHTML ) {
+ return context.getElementsByClassName( className );
+ }
+ };
+
+ /* QSA/matchesSelector
+ ---------------------------------------------------------------------- */
+
+ // QSA and matchesSelector support
+
+ // matchesSelector(:active) reports false when true (IE9/Opera 11.5)
+ rbuggyMatches = [];
+
+ // qSa(:focus) reports false when true (Chrome 21)
+ // We allow this because of a bug in IE8/9 that throws an error
+ // whenever `document.activeElement` is accessed on an iframe
+ // So, we allow :focus to pass through QSA all the time to avoid the IE error
+ // See https://bugs.jquery.com/ticket/13378
+ rbuggyQSA = [];
+
+ if ( (support.qsa = rnative.test( document.querySelectorAll )) ) {
+ // Build QSA regex
+ // Regex strategy adopted from Diego Perini
+ assert(function( el ) {
+ // Select is set to empty string on purpose
+ // This is to test IE's treatment of not explicitly
+ // setting a boolean content attribute,
+ // since its presence should be enough
+ // https://bugs.jquery.com/ticket/12359
+ docElem.appendChild( el ).innerHTML = "<a id='" + expando + "'></a>" +
+ "<select id='" + expando + "-\r\\' msallowcapture=''>" +
+ "<option selected=''></option></select>";
+
+ // Support: IE8, Opera 11-12.16
+ // Nothing should be selected when empty strings follow ^= or $= or *=
+ // The test attribute must be unknown in Opera but "safe" for WinRT
+ // https://msdn.microsoft.com/en-us/library/ie/hh465388.aspx#attribute_section
+ if ( el.querySelectorAll("[msallowcapture^='']").length ) {
+ rbuggyQSA.push( "[*^$]=" + whitespace + "*(?:''|\"\")" );
+ }
+
+ // Support: IE8
+ // Boolean attributes and "value" are not treated correctly
+ if ( !el.querySelectorAll("[selected]").length ) {
+ rbuggyQSA.push( "\\[" + whitespace + "*(?:value|" + booleans + ")" );
+ }
+
+ // Support: Chrome<29, Android<4.4, Safari<7.0+, iOS<7.0+, PhantomJS<1.9.8+
+ if ( !el.querySelectorAll( "[id~=" + expando + "-]" ).length ) {
+ rbuggyQSA.push("~=");
+ }
+
+ // Webkit/Opera - :checked should return selected option elements
+ // http://www.w3.org/TR/2011/REC-css3-selectors-20110929/#checked
+ // IE8 throws error here and will not see later tests
+ if ( !el.querySelectorAll(":checked").length ) {
+ rbuggyQSA.push(":checked");
+ }
+
+ // Support: Safari 8+, iOS 8+
+ // https://bugs.webkit.org/show_bug.cgi?id=136851
+ // In-page `selector#id sibling-combinator selector` fails
+ if ( !el.querySelectorAll( "a#" + expando + "+*" ).length ) {
+ rbuggyQSA.push(".#.+[+~]");
+ }
+ });
+
+ assert(function( el ) {
+ el.innerHTML = "<a href='' disabled='disabled'></a>" +
+ "<select disabled='disabled'><option/></select>";
+
+ // Support: Windows 8 Native Apps
+ // The type and name attributes are restricted during .innerHTML assignment
+ var input = document.createElement("input");
+ input.setAttribute( "type", "hidden" );
+ el.appendChild( input ).setAttribute( "name", "D" );
+
+ // Support: IE8
+ // Enforce case-sensitivity of name attribute
+ if ( el.querySelectorAll("[name=d]").length ) {
+ rbuggyQSA.push( "name" + whitespace + "*[*^$|!~]?=" );
+ }
+
+ // FF 3.5 - :enabled/:disabled and hidden elements (hidden elements are still enabled)
+ // IE8 throws error here and will not see later tests
+ if ( el.querySelectorAll(":enabled").length !== 2 ) {
+ rbuggyQSA.push( ":enabled", ":disabled" );
+ }
+
+ // Support: IE9-11+
+ // IE's :disabled selector does not pick up the children of disabled fieldsets
+ docElem.appendChild( el ).disabled = true;
+ if ( el.querySelectorAll(":disabled").length !== 2 ) {
+ rbuggyQSA.push( ":enabled", ":disabled" );
+ }
+
+ // Opera 10-11 does not throw on post-comma invalid pseudos
+ el.querySelectorAll("*,:x");
+ rbuggyQSA.push(",.*:");
+ });
+ }
+
+ if ( (support.matchesSelector = rnative.test( (matches = docElem.matches ||
+ docElem.webkitMatchesSelector ||
+ docElem.mozMatchesSelector ||
+ docElem.oMatchesSelector ||
+ docElem.msMatchesSelector) )) ) {
+
+ assert(function( el ) {
+ // Check to see if it's possible to do matchesSelector
+ // on a disconnected node (IE 9)
+ support.disconnectedMatch = matches.call( el, "*" );
+
+ // This should fail with an exception
+ // Gecko does not error, returns false instead
+ matches.call( el, "[s!='']:x" );
+ rbuggyMatches.push( "!=", pseudos );
+ });
+ }
+
+ rbuggyQSA = rbuggyQSA.length && new RegExp( rbuggyQSA.join("|") );
+ rbuggyMatches = rbuggyMatches.length && new RegExp( rbuggyMatches.join("|") );
+
+ /* Contains
+ ---------------------------------------------------------------------- */
+ hasCompare = rnative.test( docElem.compareDocumentPosition );
+
+ // Element contains another
+ // Purposefully self-exclusive
+ // As in, an element does not contain itself
+ contains = hasCompare || rnative.test( docElem.contains ) ?
+ function( a, b ) {
+ var adown = a.nodeType === 9 ? a.documentElement : a,
+ bup = b && b.parentNode;
+ return a === bup || !!( bup && bup.nodeType === 1 && (
+ adown.contains ?
+ adown.contains( bup ) :
+ a.compareDocumentPosition && a.compareDocumentPosition( bup ) & 16
+ ));
+ } :
+ function( a, b ) {
+ if ( b ) {
+ while ( (b = b.parentNode) ) {
+ if ( b === a ) {
+ return true;
+ }
+ }
+ }
+ return false;
+ };
+
+ /* Sorting
+ ---------------------------------------------------------------------- */
+
+ // Document order sorting
+ sortOrder = hasCompare ?
+ function( a, b ) {
+
+ // Flag for duplicate removal
+ if ( a === b ) {
+ hasDuplicate = true;
+ return 0;
+ }
+
+ // Sort on method existence if only one input has compareDocumentPosition
+ var compare = !a.compareDocumentPosition - !b.compareDocumentPosition;
+ if ( compare ) {
+ return compare;
+ }
+
+ // Calculate position if both inputs belong to the same document
+ compare = ( a.ownerDocument || a ) === ( b.ownerDocument || b ) ?
+ a.compareDocumentPosition( b ) :
+
+ // Otherwise we know they are disconnected
+ 1;
+
+ // Disconnected nodes
+ if ( compare & 1 ||
+ (!support.sortDetached && b.compareDocumentPosition( a ) === compare) ) {
+
+ // Choose the first element that is related to our preferred document
+ if ( a === document || a.ownerDocument === preferredDoc && contains(preferredDoc, a) ) {
+ return -1;
+ }
+ if ( b === document || b.ownerDocument === preferredDoc && contains(preferredDoc, b) ) {
+ return 1;
+ }
+
+ // Maintain original order
+ return sortInput ?
+ ( indexOf( sortInput, a ) - indexOf( sortInput, b ) ) :
+ 0;
+ }
+
+ return compare & 4 ? -1 : 1;
+ } :
+ function( a, b ) {
+ // Exit early if the nodes are identical
+ if ( a === b ) {
+ hasDuplicate = true;
+ return 0;
+ }
+
+ var cur,
+ i = 0,
+ aup = a.parentNode,
+ bup = b.parentNode,
+ ap = [ a ],
+ bp = [ b ];
+
+ // Parentless nodes are either documents or disconnected
+ if ( !aup || !bup ) {
+ return a === document ? -1 :
+ b === document ? 1 :
+ aup ? -1 :
+ bup ? 1 :
+ sortInput ?
+ ( indexOf( sortInput, a ) - indexOf( sortInput, b ) ) :
+ 0;
+
+ // If the nodes are siblings, we can do a quick check
+ } else if ( aup === bup ) {
+ return siblingCheck( a, b );
+ }
+
+ // Otherwise we need full lists of their ancestors for comparison
+ cur = a;
+ while ( (cur = cur.parentNode) ) {
+ ap.unshift( cur );
+ }
+ cur = b;
+ while ( (cur = cur.parentNode) ) {
+ bp.unshift( cur );
+ }
+
+ // Walk down the tree looking for a discrepancy
+ while ( ap[i] === bp[i] ) {
+ i++;
+ }
+
+ return i ?
+ // Do a sibling check if the nodes have a common ancestor
+ siblingCheck( ap[i], bp[i] ) :
+
+ // Otherwise nodes in our document sort first
+ ap[i] === preferredDoc ? -1 :
+ bp[i] === preferredDoc ? 1 :
+ 0;
+ };
+
+ return document;
+};
+
+Sizzle.matches = function( expr, elements ) {
+ return Sizzle( expr, null, null, elements );
+};
+
+Sizzle.matchesSelector = function( elem, expr ) {
+ // Set document vars if needed
+ if ( ( elem.ownerDocument || elem ) !== document ) {
+ setDocument( elem );
+ }
+
+ // Make sure that attribute selectors are quoted
+ expr = expr.replace( rattributeQuotes, "='$1']" );
+
+ if ( support.matchesSelector && documentIsHTML &&
+ !compilerCache[ expr + " " ] &&
+ ( !rbuggyMatches || !rbuggyMatches.test( expr ) ) &&
+ ( !rbuggyQSA || !rbuggyQSA.test( expr ) ) ) {
+
+ try {
+ var ret = matches.call( elem, expr );
+
+ // IE 9's matchesSelector returns false on disconnected nodes
+ if ( ret || support.disconnectedMatch ||
+ // As well, disconnected nodes are said to be in a document
+ // fragment in IE 9
+ elem.document && elem.document.nodeType !== 11 ) {
+ return ret;
+ }
+ } catch (e) {}
+ }
+
+ return Sizzle( expr, document, null, [ elem ] ).length > 0;
+};
+
+Sizzle.contains = function( context, elem ) {
+ // Set document vars if needed
+ if ( ( context.ownerDocument || context ) !== document ) {
+ setDocument( context );
+ }
+ return contains( context, elem );
+};
+
+Sizzle.attr = function( elem, name ) {
+ // Set document vars if needed
+ if ( ( elem.ownerDocument || elem ) !== document ) {
+ setDocument( elem );
+ }
+
+ var fn = Expr.attrHandle[ name.toLowerCase() ],
+ // Don't get fooled by Object.prototype properties (jQuery #13807)
+ val = fn && hasOwn.call( Expr.attrHandle, name.toLowerCase() ) ?
+ fn( elem, name, !documentIsHTML ) :
+ undefined;
+
+ return val !== undefined ?
+ val :
+ support.attributes || !documentIsHTML ?
+ elem.getAttribute( name ) :
+ (val = elem.getAttributeNode(name)) && val.specified ?
+ val.value :
+ null;
+};
+
+Sizzle.escape = function( sel ) {
+ return (sel + "").replace( rcssescape, fcssescape );
+};
+
+Sizzle.error = function( msg ) {
+ throw new Error( "Syntax error, unrecognized expression: " + msg );
+};
+
+/**
+ * Document sorting and removing duplicates
+ * @param {ArrayLike} results
+ */
+Sizzle.uniqueSort = function( results ) {
+ var elem,
+ duplicates = [],
+ j = 0,
+ i = 0;
+
+ // Unless we *know* we can detect duplicates, assume their presence
+ hasDuplicate = !support.detectDuplicates;
+ sortInput = !support.sortStable && results.slice( 0 );
+ results.sort( sortOrder );
+
+ if ( hasDuplicate ) {
+ while ( (elem = results[i++]) ) {
+ if ( elem === results[ i ] ) {
+ j = duplicates.push( i );
+ }
+ }
+ while ( j-- ) {
+ results.splice( duplicates[ j ], 1 );
+ }
+ }
+
+ // Clear input after sorting to release objects
+ // See https://github.com/jquery/sizzle/pull/225
+ sortInput = null;
+
+ return results;
+};
+
+/**
+ * Utility function for retrieving the text value of an array of DOM nodes
+ * @param {Array|Element} elem
+ */
+getText = Sizzle.getText = function( elem ) {
+ var node,
+ ret = "",
+ i = 0,
+ nodeType = elem.nodeType;
+
+ if ( !nodeType ) {
+ // If no nodeType, this is expected to be an array
+ while ( (node = elem[i++]) ) {
+ // Do not traverse comment nodes
+ ret += getText( node );
+ }
+ } else if ( nodeType === 1 || nodeType === 9 || nodeType === 11 ) {
+ // Use textContent for elements
+ // innerText usage removed for consistency of new lines (jQuery #11153)
+ if ( typeof elem.textContent === "string" ) {
+ return elem.textContent;
+ } else {
+ // Traverse its children
+ for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {
+ ret += getText( elem );
+ }
+ }
+ } else if ( nodeType === 3 || nodeType === 4 ) {
+ return elem.nodeValue;
+ }
+ // Do not include comment or processing instruction nodes
+
+ return ret;
+};
+
+Expr = Sizzle.selectors = {
+
+ // Can be adjusted by the user
+ cacheLength: 50,
+
+ createPseudo: markFunction,
+
+ match: matchExpr,
+
+ attrHandle: {},
+
+ find: {},
+
+ relative: {
+ ">": { dir: "parentNode", first: true },
+ " ": { dir: "parentNode" },
+ "+": { dir: "previousSibling", first: true },
+ "~": { dir: "previousSibling" }
+ },
+
+ preFilter: {
+ "ATTR": function( match ) {
+ match[1] = match[1].replace( runescape, funescape );
+
+ // Move the given value to match[3] whether quoted or unquoted
+ match[3] = ( match[3] || match[4] || match[5] || "" ).replace( runescape, funescape );
+
+ if ( match[2] === "~=" ) {
+ match[3] = " " + match[3] + " ";
+ }
+
+ return match.slice( 0, 4 );
+ },
+
+ "CHILD": function( match ) {
+ /* matches from matchExpr["CHILD"]
+ 1 type (only|nth|...)
+ 2 what (child|of-type)
+ 3 argument (even|odd|\d*|\d*n([+-]\d+)?|...)
+ 4 xn-component of xn+y argument ([+-]?\d*n|)
+ 5 sign of xn-component
+ 6 x of xn-component
+ 7 sign of y-component
+ 8 y of y-component
+ */
+ match[1] = match[1].toLowerCase();
+
+ if ( match[1].slice( 0, 3 ) === "nth" ) {
+ // nth-* requires argument
+ if ( !match[3] ) {
+ Sizzle.error( match[0] );
+ }
+
+ // numeric x and y parameters for Expr.filter.CHILD
+ // remember that false/true cast respectively to 0/1
+ match[4] = +( match[4] ? match[5] + (match[6] || 1) : 2 * ( match[3] === "even" || match[3] === "odd" ) );
+ match[5] = +( ( match[7] + match[8] ) || match[3] === "odd" );
+
+ // other types prohibit arguments
+ } else if ( match[3] ) {
+ Sizzle.error( match[0] );
+ }
+
+ return match;
+ },
+
+ "PSEUDO": function( match ) {
+ var excess,
+ unquoted = !match[6] && match[2];
+
+ if ( matchExpr["CHILD"].test( match[0] ) ) {
+ return null;
+ }
+
+ // Accept quoted arguments as-is
+ if ( match[3] ) {
+ match[2] = match[4] || match[5] || "";
+
+ // Strip excess characters from unquoted arguments
+ } else if ( unquoted && rpseudo.test( unquoted ) &&
+ // Get excess from tokenize (recursively)
+ (excess = tokenize( unquoted, true )) &&
+ // advance to the next closing parenthesis
+ (excess = unquoted.indexOf( ")", unquoted.length - excess ) - unquoted.length) ) {
+
+ // excess is a negative index
+ match[0] = match[0].slice( 0, excess );
+ match[2] = unquoted.slice( 0, excess );
+ }
+
+ // Return only captures needed by the pseudo filter method (type and argument)
+ return match.slice( 0, 3 );
+ }
+ },
+
+ filter: {
+
+ "TAG": function( nodeNameSelector ) {
+ var nodeName = nodeNameSelector.replace( runescape, funescape ).toLowerCase();
+ return nodeNameSelector === "*" ?
+ function() { return true; } :
+ function( elem ) {
+ return elem.nodeName && elem.nodeName.toLowerCase() === nodeName;
+ };
+ },
+
+ "CLASS": function( className ) {
+ var pattern = classCache[ className + " " ];
+
+ return pattern ||
+ (pattern = new RegExp( "(^|" + whitespace + ")" + className + "(" + whitespace + "|$)" )) &&
+ classCache( className, function( elem ) {
+ return pattern.test( typeof elem.className === "string" && elem.className || typeof elem.getAttribute !== "undefined" && elem.getAttribute("class") || "" );
+ });
+ },
+
+ "ATTR": function( name, operator, check ) {
+ return function( elem ) {
+ var result = Sizzle.attr( elem, name );
+
+ if ( result == null ) {
+ return operator === "!=";
+ }
+ if ( !operator ) {
+ return true;
+ }
+
+ result += "";
+
+ return operator === "=" ? result === check :
+ operator === "!=" ? result !== check :
+ operator === "^=" ? check && result.indexOf( check ) === 0 :
+ operator === "*=" ? check && result.indexOf( check ) > -1 :
+ operator === "$=" ? check && result.slice( -check.length ) === check :
+ operator === "~=" ? ( " " + result.replace( rwhitespace, " " ) + " " ).indexOf( check ) > -1 :
+ operator === "|=" ? result === check || result.slice( 0, check.length + 1 ) === check + "-" :
+ false;
+ };
+ },
+
+ "CHILD": function( type, what, argument, first, last ) {
+ var simple = type.slice( 0, 3 ) !== "nth",
+ forward = type.slice( -4 ) !== "last",
+ ofType = what === "of-type";
+
+ return first === 1 && last === 0 ?
+
+ // Shortcut for :nth-*(n)
+ function( elem ) {
+ return !!elem.parentNode;
+ } :
+
+ function( elem, context, xml ) {
+ var cache, uniqueCache, outerCache, node, nodeIndex, start,
+ dir = simple !== forward ? "nextSibling" : "previousSibling",
+ parent = elem.parentNode,
+ name = ofType && elem.nodeName.toLowerCase(),
+ useCache = !xml && !ofType,
+ diff = false;
+
+ if ( parent ) {
+
+ // :(first|last|only)-(child|of-type)
+ if ( simple ) {
+ while ( dir ) {
+ node = elem;
+ while ( (node = node[ dir ]) ) {
+ if ( ofType ?
+ node.nodeName.toLowerCase() === name :
+ node.nodeType === 1 ) {
+
+ return false;
+ }
+ }
+ // Reverse direction for :only-* (if we haven't yet done so)
+ start = dir = type === "only" && !start && "nextSibling";
+ }
+ return true;
+ }
+
+ start = [ forward ? parent.firstChild : parent.lastChild ];
+
+ // non-xml :nth-child(...) stores cache data on `parent`
+ if ( forward && useCache ) {
+
+ // Seek `elem` from a previously-cached index
+
+ // ...in a gzip-friendly way
+ node = parent;
+ outerCache = node[ expando ] || (node[ expando ] = {});
+
+ // Support: IE <9 only
+ // Defend against cloned attroperties (jQuery gh-1709)
+ uniqueCache = outerCache[ node.uniqueID ] ||
+ (outerCache[ node.uniqueID ] = {});
+
+ cache = uniqueCache[ type ] || [];
+ nodeIndex = cache[ 0 ] === dirruns && cache[ 1 ];
+ diff = nodeIndex && cache[ 2 ];
+ node = nodeIndex && parent.childNodes[ nodeIndex ];
+
+ while ( (node = ++nodeIndex && node && node[ dir ] ||
+
+ // Fallback to seeking `elem` from the start
+ (diff = nodeIndex = 0) || start.pop()) ) {
+
+ // When found, cache indexes on `parent` and break
+ if ( node.nodeType === 1 && ++diff && node === elem ) {
+ uniqueCache[ type ] = [ dirruns, nodeIndex, diff ];
+ break;
+ }
+ }
+
+ } else {
+ // Use previously-cached element index if available
+ if ( useCache ) {
+ // ...in a gzip-friendly way
+ node = elem;
+ outerCache = node[ expando ] || (node[ expando ] = {});
+
+ // Support: IE <9 only
+ // Defend against cloned attroperties (jQuery gh-1709)
+ uniqueCache = outerCache[ node.uniqueID ] ||
+ (outerCache[ node.uniqueID ] = {});
+
+ cache = uniqueCache[ type ] || [];
+ nodeIndex = cache[ 0 ] === dirruns && cache[ 1 ];
+ diff = nodeIndex;
+ }
+
+ // xml :nth-child(...)
+ // or :nth-last-child(...) or :nth(-last)?-of-type(...)
+ if ( diff === false ) {
+ // Use the same loop as above to seek `elem` from the start
+ while ( (node = ++nodeIndex && node && node[ dir ] ||
+ (diff = nodeIndex = 0) || start.pop()) ) {
+
+ if ( ( ofType ?
+ node.nodeName.toLowerCase() === name :
+ node.nodeType === 1 ) &&
+ ++diff ) {
+
+ // Cache the index of each encountered element
+ if ( useCache ) {
+ outerCache = node[ expando ] || (node[ expando ] = {});
+
+ // Support: IE <9 only
+ // Defend against cloned attroperties (jQuery gh-1709)
+ uniqueCache = outerCache[ node.uniqueID ] ||
+ (outerCache[ node.uniqueID ] = {});
+
+ uniqueCache[ type ] = [ dirruns, diff ];
+ }
+
+ if ( node === elem ) {
+ break;
+ }
+ }
+ }
+ }
+ }
+
+ // Incorporate the offset, then check against cycle size
+ diff -= last;
+ return diff === first || ( diff % first === 0 && diff / first >= 0 );
+ }
+ };
+ },
+
+ "PSEUDO": function( pseudo, argument ) {
+ // pseudo-class names are case-insensitive
+ // http://www.w3.org/TR/selectors/#pseudo-classes
+ // Prioritize by case sensitivity in case custom pseudos are added with uppercase letters
+ // Remember that setFilters inherits from pseudos
+ var args,
+ fn = Expr.pseudos[ pseudo ] || Expr.setFilters[ pseudo.toLowerCase() ] ||
+ Sizzle.error( "unsupported pseudo: " + pseudo );
+
+ // The user may use createPseudo to indicate that
+ // arguments are needed to create the filter function
+ // just as Sizzle does
+ if ( fn[ expando ] ) {
+ return fn( argument );
+ }
+
+ // But maintain support for old signatures
+ if ( fn.length > 1 ) {
+ args = [ pseudo, pseudo, "", argument ];
+ return Expr.setFilters.hasOwnProperty( pseudo.toLowerCase() ) ?
+ markFunction(function( seed, matches ) {
+ var idx,
+ matched = fn( seed, argument ),
+ i = matched.length;
+ while ( i-- ) {
+ idx = indexOf( seed, matched[i] );
+ seed[ idx ] = !( matches[ idx ] = matched[i] );
+ }
+ }) :
+ function( elem ) {
+ return fn( elem, 0, args );
+ };
+ }
+
+ return fn;
+ }
+ },
+
+ pseudos: {
+ // Potentially complex pseudos
+ "not": markFunction(function( selector ) {
+ // Trim the selector passed to compile
+ // to avoid treating leading and trailing
+ // spaces as combinators
+ var input = [],
+ results = [],
+ matcher = compile( selector.replace( rtrim, "$1" ) );
+
+ return matcher[ expando ] ?
+ markFunction(function( seed, matches, context, xml ) {
+ var elem,
+ unmatched = matcher( seed, null, xml, [] ),
+ i = seed.length;
+
+ // Match elements unmatched by `matcher`
+ while ( i-- ) {
+ if ( (elem = unmatched[i]) ) {
+ seed[i] = !(matches[i] = elem);
+ }
+ }
+ }) :
+ function( elem, context, xml ) {
+ input[0] = elem;
+ matcher( input, null, xml, results );
+ // Don't keep the element (issue #299)
+ input[0] = null;
+ return !results.pop();
+ };
+ }),
+
+ "has": markFunction(function( selector ) {
+ return function( elem ) {
+ return Sizzle( selector, elem ).length > 0;
+ };
+ }),
+
+ "contains": markFunction(function( text ) {
+ text = text.replace( runescape, funescape );
+ return function( elem ) {
+ return ( elem.textContent || elem.innerText || getText( elem ) ).indexOf( text ) > -1;
+ };
+ }),
+
+ // "Whether an element is represented by a :lang() selector
+ // is based solely on the element's language value
+ // being equal to the identifier C,
+ // or beginning with the identifier C immediately followed by "-".
+ // The matching of C against the element's language value is performed case-insensitively.
+ // The identifier C does not have to be a valid language name."
+ // http://www.w3.org/TR/selectors/#lang-pseudo
+ "lang": markFunction( function( lang ) {
+ // lang value must be a valid identifier
+ if ( !ridentifier.test(lang || "") ) {
+ Sizzle.error( "unsupported lang: " + lang );
+ }
+ lang = lang.replace( runescape, funescape ).toLowerCase();
+ return function( elem ) {
+ var elemLang;
+ do {
+ if ( (elemLang = documentIsHTML ?
+ elem.lang :
+ elem.getAttribute("xml:lang") || elem.getAttribute("lang")) ) {
+
+ elemLang = elemLang.toLowerCase();
+ return elemLang === lang || elemLang.indexOf( lang + "-" ) === 0;
+ }
+ } while ( (elem = elem.parentNode) && elem.nodeType === 1 );
+ return false;
+ };
+ }),
+
+ // Miscellaneous
+ "target": function( elem ) {
+ var hash = window.location && window.location.hash;
+ return hash && hash.slice( 1 ) === elem.id;
+ },
+
+ "root": function( elem ) {
+ return elem === docElem;
+ },
+
+ "focus": function( elem ) {
+ return elem === document.activeElement && (!document.hasFocus || document.hasFocus()) && !!(elem.type || elem.href || ~elem.tabIndex);
+ },
+
+ // Boolean properties
+ "enabled": createDisabledPseudo( false ),
+ "disabled": createDisabledPseudo( true ),
+
+ "checked": function( elem ) {
+ // In CSS3, :checked should return both checked and selected elements
+ // http://www.w3.org/TR/2011/REC-css3-selectors-20110929/#checked
+ var nodeName = elem.nodeName.toLowerCase();
+ return (nodeName === "input" && !!elem.checked) || (nodeName === "option" && !!elem.selected);
+ },
+
+ "selected": function( elem ) {
+ // Accessing this property makes selected-by-default
+ // options in Safari work properly
+ if ( elem.parentNode ) {
+ elem.parentNode.selectedIndex;
+ }
+
+ return elem.selected === true;
+ },
+
+ // Contents
+ "empty": function( elem ) {
+ // http://www.w3.org/TR/selectors/#empty-pseudo
+ // :empty is negated by element (1) or content nodes (text: 3; cdata: 4; entity ref: 5),
+ // but not by others (comment: 8; processing instruction: 7; etc.)
+ // nodeType < 6 works because attributes (2) do not appear as children
+ for ( elem = elem.firstChild; elem; elem = elem.nextSibling ) {
+ if ( elem.nodeType < 6 ) {
+ return false;
+ }
+ }
+ return true;
+ },
+
+ "parent": function( elem ) {
+ return !Expr.pseudos["empty"]( elem );
+ },
+
+ // Element/input types
+ "header": function( elem ) {
+ return rheader.test( elem.nodeName );
+ },
+
+ "input": function( elem ) {
+ return rinputs.test( elem.nodeName );
+ },
+
+ "button": function( elem ) {
+ var name = elem.nodeName.toLowerCase();
+ return name === "input" && elem.type === "button" || name === "button";
+ },
+
+ "text": function( elem ) {
+ var attr;
+ return elem.nodeName.toLowerCase() === "input" &&
+ elem.type === "text" &&
+
+ // Support: IE<8
+ // New HTML5 attribute values (e.g., "search") appear with elem.type === "text"
+ ( (attr = elem.getAttribute("type")) == null || attr.toLowerCase() === "text" );
+ },
+
+ // Position-in-collection
+ "first": createPositionalPseudo(function() {
+ return [ 0 ];
+ }),
+
+ "last": createPositionalPseudo(function( matchIndexes, length ) {
+ return [ length - 1 ];
+ }),
+
+ "eq": createPositionalPseudo(function( matchIndexes, length, argument ) {
+ return [ argument < 0 ? argument + length : argument ];
+ }),
+
+ "even": createPositionalPseudo(function( matchIndexes, length ) {
+ var i = 0;
+ for ( ; i < length; i += 2 ) {
+ matchIndexes.push( i );
+ }
+ return matchIndexes;
+ }),
+
+ "odd": createPositionalPseudo(function( matchIndexes, length ) {
+ var i = 1;
+ for ( ; i < length; i += 2 ) {
+ matchIndexes.push( i );
+ }
+ return matchIndexes;
+ }),
+
+ "lt": createPositionalPseudo(function( matchIndexes, length, argument ) {
+ var i = argument < 0 ? argument + length : argument;
+ for ( ; --i >= 0; ) {
+ matchIndexes.push( i );
+ }
+ return matchIndexes;
+ }),
+
+ "gt": createPositionalPseudo(function( matchIndexes, length, argument ) {
+ var i = argument < 0 ? argument + length : argument;
+ for ( ; ++i < length; ) {
+ matchIndexes.push( i );
+ }
+ return matchIndexes;
+ })
+ }
+};
+
+Expr.pseudos["nth"] = Expr.pseudos["eq"];
+
+// Add button/input type pseudos
+for ( i in { radio: true, checkbox: true, file: true, password: true, image: true } ) {
+ Expr.pseudos[ i ] = createInputPseudo( i );
+}
+for ( i in { submit: true, reset: true } ) {
+ Expr.pseudos[ i ] = createButtonPseudo( i );
+}
+
+// Easy API for creating new setFilters
+function setFilters() {}
+setFilters.prototype = Expr.filters = Expr.pseudos;
+Expr.setFilters = new setFilters();
+
+tokenize = Sizzle.tokenize = function( selector, parseOnly ) {
+ var matched, match, tokens, type,
+ soFar, groups, preFilters,
+ cached = tokenCache[ selector + " " ];
+
+ if ( cached ) {
+ return parseOnly ? 0 : cached.slice( 0 );
+ }
+
+ soFar = selector;
+ groups = [];
+ preFilters = Expr.preFilter;
+
+ while ( soFar ) {
+
+ // Comma and first run
+ if ( !matched || (match = rcomma.exec( soFar )) ) {
+ if ( match ) {
+ // Don't consume trailing commas as valid
+ soFar = soFar.slice( match[0].length ) || soFar;
+ }
+ groups.push( (tokens = []) );
+ }
+
+ matched = false;
+
+ // Combinators
+ if ( (match = rcombinators.exec( soFar )) ) {
+ matched = match.shift();
+ tokens.push({
+ value: matched,
+ // Cast descendant combinators to space
+ type: match[0].replace( rtrim, " " )
+ });
+ soFar = soFar.slice( matched.length );
+ }
+
+ // Filters
+ for ( type in Expr.filter ) {
+ if ( (match = matchExpr[ type ].exec( soFar )) && (!preFilters[ type ] ||
+ (match = preFilters[ type ]( match ))) ) {
+ matched = match.shift();
+ tokens.push({
+ value: matched,
+ type: type,
+ matches: match
+ });
+ soFar = soFar.slice( matched.length );
+ }
+ }
+
+ if ( !matched ) {
+ break;
+ }
+ }
+
+ // Return the length of the invalid excess
+ // if we're just parsing
+ // Otherwise, throw an error or return tokens
+ return parseOnly ?
+ soFar.length :
+ soFar ?
+ Sizzle.error( selector ) :
+ // Cache the tokens
+ tokenCache( selector, groups ).slice( 0 );
+};
+
+function toSelector( tokens ) {
+ var i = 0,
+ len = tokens.length,
+ selector = "";
+ for ( ; i < len; i++ ) {
+ selector += tokens[i].value;
+ }
+ return selector;
+}
+
+function addCombinator( matcher, combinator, base ) {
+ var dir = combinator.dir,
+ skip = combinator.next,
+ key = skip || dir,
+ checkNonElements = base && key === "parentNode",
+ doneName = done++;
+
+ return combinator.first ?
+ // Check against closest ancestor/preceding element
+ function( elem, context, xml ) {
+ while ( (elem = elem[ dir ]) ) {
+ if ( elem.nodeType === 1 || checkNonElements ) {
+ return matcher( elem, context, xml );
+ }
+ }
+ return false;
+ } :
+
+ // Check against all ancestor/preceding elements
+ function( elem, context, xml ) {
+ var oldCache, uniqueCache, outerCache,
+ newCache = [ dirruns, doneName ];
+
+ // We can't set arbitrary data on XML nodes, so they don't benefit from combinator caching
+ if ( xml ) {
+ while ( (elem = elem[ dir ]) ) {
+ if ( elem.nodeType === 1 || checkNonElements ) {
+ if ( matcher( elem, context, xml ) ) {
+ return true;
+ }
+ }
+ }
+ } else {
+ while ( (elem = elem[ dir ]) ) {
+ if ( elem.nodeType === 1 || checkNonElements ) {
+ outerCache = elem[ expando ] || (elem[ expando ] = {});
+
+ // Support: IE <9 only
+ // Defend against cloned attroperties (jQuery gh-1709)
+ uniqueCache = outerCache[ elem.uniqueID ] || (outerCache[ elem.uniqueID ] = {});
+
+ if ( skip && skip === elem.nodeName.toLowerCase() ) {
+ elem = elem[ dir ] || elem;
+ } else if ( (oldCache = uniqueCache[ key ]) &&
+ oldCache[ 0 ] === dirruns && oldCache[ 1 ] === doneName ) {
+
+ // Assign to newCache so results back-propagate to previous elements
+ return (newCache[ 2 ] = oldCache[ 2 ]);
+ } else {
+ // Reuse newcache so results back-propagate to previous elements
+ uniqueCache[ key ] = newCache;
+
+ // A match means we're done; a fail means we have to keep checking
+ if ( (newCache[ 2 ] = matcher( elem, context, xml )) ) {
+ return true;
+ }
+ }
+ }
+ }
+ }
+ return false;
+ };
+}
+
+function elementMatcher( matchers ) {
+ return matchers.length > 1 ?
+ function( elem, context, xml ) {
+ var i = matchers.length;
+ while ( i-- ) {
+ if ( !matchers[i]( elem, context, xml ) ) {
+ return false;
+ }
+ }
+ return true;
+ } :
+ matchers[0];
+}
+
+function multipleContexts( selector, contexts, results ) {
+ var i = 0,
+ len = contexts.length;
+ for ( ; i < len; i++ ) {
+ Sizzle( selector, contexts[i], results );
+ }
+ return results;
+}
+
+function condense( unmatched, map, filter, context, xml ) {
+ var elem,
+ newUnmatched = [],
+ i = 0,
+ len = unmatched.length,
+ mapped = map != null;
+
+ for ( ; i < len; i++ ) {
+ if ( (elem = unmatched[i]) ) {
+ if ( !filter || filter( elem, context, xml ) ) {
+ newUnmatched.push( elem );
+ if ( mapped ) {
+ map.push( i );
+ }
+ }
+ }
+ }
+
+ return newUnmatched;
+}
+
+function setMatcher( preFilter, selector, matcher, postFilter, postFinder, postSelector ) {
+ if ( postFilter && !postFilter[ expando ] ) {
+ postFilter = setMatcher( postFilter );
+ }
+ if ( postFinder && !postFinder[ expando ] ) {
+ postFinder = setMatcher( postFinder, postSelector );
+ }
+ return markFunction(function( seed, results, context, xml ) {
+ var temp, i, elem,
+ preMap = [],
+ postMap = [],
+ preexisting = results.length,
+
+ // Get initial elements from seed or context
+ elems = seed || multipleContexts( selector || "*", context.nodeType ? [ context ] : context, [] ),
+
+ // Prefilter to get matcher input, preserving a map for seed-results synchronization
+ matcherIn = preFilter && ( seed || !selector ) ?
+ condense( elems, preMap, preFilter, context, xml ) :
+ elems,
+
+ matcherOut = matcher ?
+ // If we have a postFinder, or filtered seed, or non-seed postFilter or preexisting results,
+ postFinder || ( seed ? preFilter : preexisting || postFilter ) ?
+
+ // ...intermediate processing is necessary
+ [] :
+
+ // ...otherwise use results directly
+ results :
+ matcherIn;
+
+ // Find primary matches
+ if ( matcher ) {
+ matcher( matcherIn, matcherOut, context, xml );
+ }
+
+ // Apply postFilter
+ if ( postFilter ) {
+ temp = condense( matcherOut, postMap );
+ postFilter( temp, [], context, xml );
+
+ // Un-match failing elements by moving them back to matcherIn
+ i = temp.length;
+ while ( i-- ) {
+ if ( (elem = temp[i]) ) {
+ matcherOut[ postMap[i] ] = !(matcherIn[ postMap[i] ] = elem);
+ }
+ }
+ }
+
+ if ( seed ) {
+ if ( postFinder || preFilter ) {
+ if ( postFinder ) {
+ // Get the final matcherOut by condensing this intermediate into postFinder contexts
+ temp = [];
+ i = matcherOut.length;
+ while ( i-- ) {
+ if ( (elem = matcherOut[i]) ) {
+ // Restore matcherIn since elem is not yet a final match
+ temp.push( (matcherIn[i] = elem) );
+ }
+ }
+ postFinder( null, (matcherOut = []), temp, xml );
+ }
+
+ // Move matched elements from seed to results to keep them synchronized
+ i = matcherOut.length;
+ while ( i-- ) {
+ if ( (elem = matcherOut[i]) &&
+ (temp = postFinder ? indexOf( seed, elem ) : preMap[i]) > -1 ) {
+
+ seed[temp] = !(results[temp] = elem);
+ }
+ }
+ }
+
+ // Add elements to results, through postFinder if defined
+ } else {
+ matcherOut = condense(
+ matcherOut === results ?
+ matcherOut.splice( preexisting, matcherOut.length ) :
+ matcherOut
+ );
+ if ( postFinder ) {
+ postFinder( null, results, matcherOut, xml );
+ } else {
+ push.apply( results, matcherOut );
+ }
+ }
+ });
+}
+
+function matcherFromTokens( tokens ) {
+ var checkContext, matcher, j,
+ len = tokens.length,
+ leadingRelative = Expr.relative[ tokens[0].type ],
+ implicitRelative = leadingRelative || Expr.relative[" "],
+ i = leadingRelative ? 1 : 0,
+
+ // The foundational matcher ensures that elements are reachable from top-level context(s)
+ matchContext = addCombinator( function( elem ) {
+ return elem === checkContext;
+ }, implicitRelative, true ),
+ matchAnyContext = addCombinator( function( elem ) {
+ return indexOf( checkContext, elem ) > -1;
+ }, implicitRelative, true ),
+ matchers = [ function( elem, context, xml ) {
+ var ret = ( !leadingRelative && ( xml || context !== outermostContext ) ) || (
+ (checkContext = context).nodeType ?
+ matchContext( elem, context, xml ) :
+ matchAnyContext( elem, context, xml ) );
+ // Avoid hanging onto element (issue #299)
+ checkContext = null;
+ return ret;
+ } ];
+
+ for ( ; i < len; i++ ) {
+ if ( (matcher = Expr.relative[ tokens[i].type ]) ) {
+ matchers = [ addCombinator(elementMatcher( matchers ), matcher) ];
+ } else {
+ matcher = Expr.filter[ tokens[i].type ].apply( null, tokens[i].matches );
+
+ // Return special upon seeing a positional matcher
+ if ( matcher[ expando ] ) {
+ // Find the next relative operator (if any) for proper handling
+ j = ++i;
+ for ( ; j < len; j++ ) {
+ if ( Expr.relative[ tokens[j].type ] ) {
+ break;
+ }
+ }
+ return setMatcher(
+ i > 1 && elementMatcher( matchers ),
+ i > 1 && toSelector(
+ // If the preceding token was a descendant combinator, insert an implicit any-element `*`
+ tokens.slice( 0, i - 1 ).concat({ value: tokens[ i - 2 ].type === " " ? "*" : "" })
+ ).replace( rtrim, "$1" ),
+ matcher,
+ i < j && matcherFromTokens( tokens.slice( i, j ) ),
+ j < len && matcherFromTokens( (tokens = tokens.slice( j )) ),
+ j < len && toSelector( tokens )
+ );
+ }
+ matchers.push( matcher );
+ }
+ }
+
+ return elementMatcher( matchers );
+}
+
+function matcherFromGroupMatchers( elementMatchers, setMatchers ) {
+ var bySet = setMatchers.length > 0,
+ byElement = elementMatchers.length > 0,
+ superMatcher = function( seed, context, xml, results, outermost ) {
+ var elem, j, matcher,
+ matchedCount = 0,
+ i = "0",
+ unmatched = seed && [],
+ setMatched = [],
+ contextBackup = outermostContext,
+ // We must always have either seed elements or outermost context
+ elems = seed || byElement && Expr.find["TAG"]( "*", outermost ),
+ // Use integer dirruns iff this is the outermost matcher
+ dirrunsUnique = (dirruns += contextBackup == null ? 1 : Math.random() || 0.1),
+ len = elems.length;
+
+ if ( outermost ) {
+ outermostContext = context === document || context || outermost;
+ }
+
+ // Add elements passing elementMatchers directly to results
+ // Support: IE<9, Safari
+ // Tolerate NodeList properties (IE: "length"; Safari: <number>) matching elements by id
+ for ( ; i !== len && (elem = elems[i]) != null; i++ ) {
+ if ( byElement && elem ) {
+ j = 0;
+ if ( !context && elem.ownerDocument !== document ) {
+ setDocument( elem );
+ xml = !documentIsHTML;
+ }
+ while ( (matcher = elementMatchers[j++]) ) {
+ if ( matcher( elem, context || document, xml) ) {
+ results.push( elem );
+ break;
+ }
+ }
+ if ( outermost ) {
+ dirruns = dirrunsUnique;
+ }
+ }
+
+ // Track unmatched elements for set filters
+ if ( bySet ) {
+ // They will have gone through all possible matchers
+ if ( (elem = !matcher && elem) ) {
+ matchedCount--;
+ }
+
+ // Lengthen the array for every element, matched or not
+ if ( seed ) {
+ unmatched.push( elem );
+ }
+ }
+ }
+
+ // `i` is now the count of elements visited above, and adding it to `matchedCount`
+ // makes the latter nonnegative.
+ matchedCount += i;
+
+ // Apply set filters to unmatched elements
+ // NOTE: This can be skipped if there are no unmatched elements (i.e., `matchedCount`
+ // equals `i`), unless we didn't visit _any_ elements in the above loop because we have
+ // no element matchers and no seed.
+ // Incrementing an initially-string "0" `i` allows `i` to remain a string only in that
+ // case, which will result in a "00" `matchedCount` that differs from `i` but is also
+ // numerically zero.
+ if ( bySet && i !== matchedCount ) {
+ j = 0;
+ while ( (matcher = setMatchers[j++]) ) {
+ matcher( unmatched, setMatched, context, xml );
+ }
+
+ if ( seed ) {
+ // Reintegrate element matches to eliminate the need for sorting
+ if ( matchedCount > 0 ) {
+ while ( i-- ) {
+ if ( !(unmatched[i] || setMatched[i]) ) {
+ setMatched[i] = pop.call( results );
+ }
+ }
+ }
+
+ // Discard index placeholder values to get only actual matches
+ setMatched = condense( setMatched );
+ }
+
+ // Add matches to results
+ push.apply( results, setMatched );
+
+ // Seedless set matches succeeding multiple successful matchers stipulate sorting
+ if ( outermost && !seed && setMatched.length > 0 &&
+ ( matchedCount + setMatchers.length ) > 1 ) {
+
+ Sizzle.uniqueSort( results );
+ }
+ }
+
+ // Override manipulation of globals by nested matchers
+ if ( outermost ) {
+ dirruns = dirrunsUnique;
+ outermostContext = contextBackup;
+ }
+
+ return unmatched;
+ };
+
+ return bySet ?
+ markFunction( superMatcher ) :
+ superMatcher;
+}
+
+compile = Sizzle.compile = function( selector, match /* Internal Use Only */ ) {
+ var i,
+ setMatchers = [],
+ elementMatchers = [],
+ cached = compilerCache[ selector + " " ];
+
+ if ( !cached ) {
+ // Generate a function of recursive functions that can be used to check each element
+ if ( !match ) {
+ match = tokenize( selector );
+ }
+ i = match.length;
+ while ( i-- ) {
+ cached = matcherFromTokens( match[i] );
+ if ( cached[ expando ] ) {
+ setMatchers.push( cached );
+ } else {
+ elementMatchers.push( cached );
+ }
+ }
+
+ // Cache the compiled function
+ cached = compilerCache( selector, matcherFromGroupMatchers( elementMatchers, setMatchers ) );
+
+ // Save selector and tokenization
+ cached.selector = selector;
+ }
+ return cached;
+};
+
+/**
+ * A low-level selection function that works with Sizzle's compiled
+ * selector functions
+ * @param {String|Function} selector A selector or a pre-compiled
+ * selector function built with Sizzle.compile
+ * @param {Element} context
+ * @param {Array} [results]
+ * @param {Array} [seed] A set of elements to match against
+ */
+select = Sizzle.select = function( selector, context, results, seed ) {
+ var i, tokens, token, type, find,
+ compiled = typeof selector === "function" && selector,
+ match = !seed && tokenize( (selector = compiled.selector || selector) );
+
+ results = results || [];
+
+ // Try to minimize operations if there is only one selector in the list and no seed
+ // (the latter of which guarantees us context)
+ if ( match.length === 1 ) {
+
+ // Reduce context if the leading compound selector is an ID
+ tokens = match[0] = match[0].slice( 0 );
+ if ( tokens.length > 2 && (token = tokens[0]).type === "ID" &&
+ context.nodeType === 9 && documentIsHTML && Expr.relative[ tokens[1].type ] ) {
+
+ context = ( Expr.find["ID"]( token.matches[0].replace(runescape, funescape), context ) || [] )[0];
+ if ( !context ) {
+ return results;
+
+ // Precompiled matchers will still verify ancestry, so step up a level
+ } else if ( compiled ) {
+ context = context.parentNode;
+ }
+
+ selector = selector.slice( tokens.shift().value.length );
+ }
+
+ // Fetch a seed set for right-to-left matching
+ i = matchExpr["needsContext"].test( selector ) ? 0 : tokens.length;
+ while ( i-- ) {
+ token = tokens[i];
+
+ // Abort if we hit a combinator
+ if ( Expr.relative[ (type = token.type) ] ) {
+ break;
+ }
+ if ( (find = Expr.find[ type ]) ) {
+ // Search, expanding context for leading sibling combinators
+ if ( (seed = find(
+ token.matches[0].replace( runescape, funescape ),
+ rsibling.test( tokens[0].type ) && testContext( context.parentNode ) || context
+ )) ) {
+
+ // If seed is empty or no tokens remain, we can return early
+ tokens.splice( i, 1 );
+ selector = seed.length && toSelector( tokens );
+ if ( !selector ) {
+ push.apply( results, seed );
+ return results;
+ }
+
+ break;
+ }
+ }
+ }
+ }
+
+ // Compile and execute a filtering function if one is not provided
+ // Provide `match` to avoid retokenization if we modified the selector above
+ ( compiled || compile( selector, match ) )(
+ seed,
+ context,
+ !documentIsHTML,
+ results,
+ !context || rsibling.test( selector ) && testContext( context.parentNode ) || context
+ );
+ return results;
+};
+
+// One-time assignments
+
+// Sort stability
+support.sortStable = expando.split("").sort( sortOrder ).join("") === expando;
+
+// Support: Chrome 14-35+
+// Always assume duplicates if they aren't passed to the comparison function
+support.detectDuplicates = !!hasDuplicate;
+
+// Initialize against the default document
+setDocument();
+
+// Support: Webkit<537.32 - Safari 6.0.3/Chrome 25 (fixed in Chrome 27)
+// Detached nodes confoundingly follow *each other*
+support.sortDetached = assert(function( el ) {
+ // Should return 1, but returns 4 (following)
+ return el.compareDocumentPosition( document.createElement("fieldset") ) & 1;
+});
+
+// Support: IE<8
+// Prevent attribute/property "interpolation"
+// https://msdn.microsoft.com/en-us/library/ms536429%28VS.85%29.aspx
+if ( !assert(function( el ) {
+ el.innerHTML = "<a href='#'></a>";
+ return el.firstChild.getAttribute("href") === "#" ;
+}) ) {
+ addHandle( "type|href|height|width", function( elem, name, isXML ) {
+ if ( !isXML ) {
+ return elem.getAttribute( name, name.toLowerCase() === "type" ? 1 : 2 );
+ }
+ });
+}
+
+// Support: IE<9
+// Use defaultValue in place of getAttribute("value")
+if ( !support.attributes || !assert(function( el ) {
+ el.innerHTML = "<input/>";
+ el.firstChild.setAttribute( "value", "" );
+ return el.firstChild.getAttribute( "value" ) === "";
+}) ) {
+ addHandle( "value", function( elem, name, isXML ) {
+ if ( !isXML && elem.nodeName.toLowerCase() === "input" ) {
+ return elem.defaultValue;
+ }
+ });
+}
+
+// Support: IE<9
+// Use getAttributeNode to fetch booleans when getAttribute lies
+if ( !assert(function( el ) {
+ return el.getAttribute("disabled") == null;
+}) ) {
+ addHandle( booleans, function( elem, name, isXML ) {
+ var val;
+ if ( !isXML ) {
+ return elem[ name ] === true ? name.toLowerCase() :
+ (val = elem.getAttributeNode( name )) && val.specified ?
+ val.value :
+ null;
+ }
+ });
+}
+
+return Sizzle;
+
+})( window );
+
+
+
+jQuery.find = Sizzle;
+jQuery.expr = Sizzle.selectors;
+
+// Deprecated
+jQuery.expr[ ":" ] = jQuery.expr.pseudos;
+jQuery.uniqueSort = jQuery.unique = Sizzle.uniqueSort;
+jQuery.text = Sizzle.getText;
+jQuery.isXMLDoc = Sizzle.isXML;
+jQuery.contains = Sizzle.contains;
+jQuery.escapeSelector = Sizzle.escape;
+
+
+
+
+var dir = function( elem, dir, until ) {
+ var matched = [],
+ truncate = until !== undefined;
+
+ while ( ( elem = elem[ dir ] ) && elem.nodeType !== 9 ) {
+ if ( elem.nodeType === 1 ) {
+ if ( truncate && jQuery( elem ).is( until ) ) {
+ break;
+ }
+ matched.push( elem );
+ }
+ }
+ return matched;
+};
+
+
+var siblings = function( n, elem ) {
+ var matched = [];
+
+ for ( ; n; n = n.nextSibling ) {
+ if ( n.nodeType === 1 && n !== elem ) {
+ matched.push( n );
+ }
+ }
+
+ return matched;
+};
+
+
+var rneedsContext = jQuery.expr.match.needsContext;
+
+
+
+function nodeName( elem, name ) {
+
+ return elem.nodeName && elem.nodeName.toLowerCase() === name.toLowerCase();
+
+};
+var rsingleTag = ( /^<([a-z][^\/\0>:\x20\t\r\n\f]*)[\x20\t\r\n\f]*\/?>(?:<\/\1>|)$/i );
+
+
+
+var risSimple = /^.[^:#\[\.,]*$/;
+
+// Implement the identical functionality for filter and not
+function winnow( elements, qualifier, not ) {
+ if ( jQuery.isFunction( qualifier ) ) {
+ return jQuery.grep( elements, function( elem, i ) {
+ return !!qualifier.call( elem, i, elem ) !== not;
+ } );
+ }
+
+ // Single element
+ if ( qualifier.nodeType ) {
+ return jQuery.grep( elements, function( elem ) {
+ return ( elem === qualifier ) !== not;
+ } );
+ }
+
+ // Arraylike of elements (jQuery, arguments, Array)
+ if ( typeof qualifier !== "string" ) {
+ return jQuery.grep( elements, function( elem ) {
+ return ( indexOf.call( qualifier, elem ) > -1 ) !== not;
+ } );
+ }
+
+ // Simple selector that can be filtered directly, removing non-Elements
+ if ( risSimple.test( qualifier ) ) {
+ return jQuery.filter( qualifier, elements, not );
+ }
+
+ // Complex selector, compare the two sets, removing non-Elements
+ qualifier = jQuery.filter( qualifier, elements );
+ return jQuery.grep( elements, function( elem ) {
+ return ( indexOf.call( qualifier, elem ) > -1 ) !== not && elem.nodeType === 1;
+ } );
+}
+
+jQuery.filter = function( expr, elems, not ) {
+ var elem = elems[ 0 ];
+
+ if ( not ) {
+ expr = ":not(" + expr + ")";
+ }
+
+ if ( elems.length === 1 && elem.nodeType === 1 ) {
+ return jQuery.find.matchesSelector( elem, expr ) ? [ elem ] : [];
+ }
+
+ return jQuery.find.matches( expr, jQuery.grep( elems, function( elem ) {
+ return elem.nodeType === 1;
+ } ) );
+};
+
+jQuery.fn.extend( {
+ find: function( selector ) {
+ var i, ret,
+ len = this.length,
+ self = this;
+
+ if ( typeof selector !== "string" ) {
+ return this.pushStack( jQuery( selector ).filter( function() {
+ for ( i = 0; i < len; i++ ) {
+ if ( jQuery.contains( self[ i ], this ) ) {
+ return true;
+ }
+ }
+ } ) );
+ }
+
+ ret = this.pushStack( [] );
+
+ for ( i = 0; i < len; i++ ) {
+ jQuery.find( selector, self[ i ], ret );
+ }
+
+ return len > 1 ? jQuery.uniqueSort( ret ) : ret;
+ },
+ filter: function( selector ) {
+ return this.pushStack( winnow( this, selector || [], false ) );
+ },
+ not: function( selector ) {
+ return this.pushStack( winnow( this, selector || [], true ) );
+ },
+ is: function( selector ) {
+ return !!winnow(
+ this,
+
+ // If this is a positional/relative selector, check membership in the returned set
+ // so $("p:first").is("p:last") won't return true for a doc with two "p".
+ typeof selector === "string" && rneedsContext.test( selector ) ?
+ jQuery( selector ) :
+ selector || [],
+ false
+ ).length;
+ }
+} );
+
+
+// Initialize a jQuery object
+
+
+// A central reference to the root jQuery(document)
+var rootjQuery,
+
+ // A simple way to check for HTML strings
+ // Prioritize #id over <tag> to avoid XSS via location.hash (#9521)
+ // Strict HTML recognition (#11290: must start with <)
+ // Shortcut simple #id case for speed
+ rquickExpr = /^(?:\s*(<[\w\W]+>)[^>]*|#([\w-]+))$/,
+
+ init = jQuery.fn.init = function( selector, context, root ) {
+ var match, elem;
+
+ // HANDLE: $(""), $(null), $(undefined), $(false)
+ if ( !selector ) {
+ return this;
+ }
+
+ // Method init() accepts an alternate rootjQuery
+ // so migrate can support jQuery.sub (gh-2101)
+ root = root || rootjQuery;
+
+ // Handle HTML strings
+ if ( typeof selector === "string" ) {
+ if ( selector[ 0 ] === "<" &&
+ selector[ selector.length - 1 ] === ">" &&
+ selector.length >= 3 ) {
+
+ // Assume that strings that start and end with <> are HTML and skip the regex check
+ match = [ null, selector, null ];
+
+ } else {
+ match = rquickExpr.exec( selector );
+ }
+
+ // Match html or make sure no context is specified for #id
+ if ( match && ( match[ 1 ] || !context ) ) {
+
+ // HANDLE: $(html) -> $(array)
+ if ( match[ 1 ] ) {
+ context = context instanceof jQuery ? context[ 0 ] : context;
+
+ // Option to run scripts is true for back-compat
+ // Intentionally let the error be thrown if parseHTML is not present
+ jQuery.merge( this, jQuery.parseHTML(
+ match[ 1 ],
+ context && context.nodeType ? context.ownerDocument || context : document,
+ true
+ ) );
+
+ // HANDLE: $(html, props)
+ if ( rsingleTag.test( match[ 1 ] ) && jQuery.isPlainObject( context ) ) {
+ for ( match in context ) {
+
+ // Properties of context are called as methods if possible
+ if ( jQuery.isFunction( this[ match ] ) ) {
+ this[ match ]( context[ match ] );
+
+ // ...and otherwise set as attributes
+ } else {
+ this.attr( match, context[ match ] );
+ }
+ }
+ }
+
+ return this;
+
+ // HANDLE: $(#id)
+ } else {
+ elem = document.getElementById( match[ 2 ] );
+
+ if ( elem ) {
+
+ // Inject the element directly into the jQuery object
+ this[ 0 ] = elem;
+ this.length = 1;
+ }
+ return this;
+ }
+
+ // HANDLE: $(expr, $(...))
+ } else if ( !context || context.jquery ) {
+ return ( context || root ).find( selector );
+
+ // HANDLE: $(expr, context)
+ // (which is just equivalent to: $(context).find(expr)
+ } else {
+ return this.constructor( context ).find( selector );
+ }
+
+ // HANDLE: $(DOMElement)
+ } else if ( selector.nodeType ) {
+ this[ 0 ] = selector;
+ this.length = 1;
+ return this;
+
+ // HANDLE: $(function)
+ // Shortcut for document ready
+ } else if ( jQuery.isFunction( selector ) ) {
+ return root.ready !== undefined ?
+ root.ready( selector ) :
+
+ // Execute immediately if ready is not present
+ selector( jQuery );
+ }
+
+ return jQuery.makeArray( selector, this );
+ };
+
+// Give the init function the jQuery prototype for later instantiation
+init.prototype = jQuery.fn;
+
+// Initialize central reference
+rootjQuery = jQuery( document );
+
+
+var rparentsprev = /^(?:parents|prev(?:Until|All))/,
+
+ // Methods guaranteed to produce a unique set when starting from a unique set
+ guaranteedUnique = {
+ children: true,
+ contents: true,
+ next: true,
+ prev: true
+ };
+
+jQuery.fn.extend( {
+ has: function( target ) {
+ var targets = jQuery( target, this ),
+ l = targets.length;
+
+ return this.filter( function() {
+ var i = 0;
+ for ( ; i < l; i++ ) {
+ if ( jQuery.contains( this, targets[ i ] ) ) {
+ return true;
+ }
+ }
+ } );
+ },
+
+ closest: function( selectors, context ) {
+ var cur,
+ i = 0,
+ l = this.length,
+ matched = [],
+ targets = typeof selectors !== "string" && jQuery( selectors );
+
+ // Positional selectors never match, since there's no _selection_ context
+ if ( !rneedsContext.test( selectors ) ) {
+ for ( ; i < l; i++ ) {
+ for ( cur = this[ i ]; cur && cur !== context; cur = cur.parentNode ) {
+
+ // Always skip document fragments
+ if ( cur.nodeType < 11 && ( targets ?
+ targets.index( cur ) > -1 :
+
+ // Don't pass non-elements to Sizzle
+ cur.nodeType === 1 &&
+ jQuery.find.matchesSelector( cur, selectors ) ) ) {
+
+ matched.push( cur );
+ break;
+ }
+ }
+ }
+ }
+
+ return this.pushStack( matched.length > 1 ? jQuery.uniqueSort( matched ) : matched );
+ },
+
+ // Determine the position of an element within the set
+ index: function( elem ) {
+
+ // No argument, return index in parent
+ if ( !elem ) {
+ return ( this[ 0 ] && this[ 0 ].parentNode ) ? this.first().prevAll().length : -1;
+ }
+
+ // Index in selector
+ if ( typeof elem === "string" ) {
+ return indexOf.call( jQuery( elem ), this[ 0 ] );
+ }
+
+ // Locate the position of the desired element
+ return indexOf.call( this,
+
+ // If it receives a jQuery object, the first element is used
+ elem.jquery ? elem[ 0 ] : elem
+ );
+ },
+
+ add: function( selector, context ) {
+ return this.pushStack(
+ jQuery.uniqueSort(
+ jQuery.merge( this.get(), jQuery( selector, context ) )
+ )
+ );
+ },
+
+ addBack: function( selector ) {
+ return this.add( selector == null ?
+ this.prevObject : this.prevObject.filter( selector )
+ );
+ }
+} );
+
+function sibling( cur, dir ) {
+ while ( ( cur = cur[ dir ] ) && cur.nodeType !== 1 ) {}
+ return cur;
+}
+
+jQuery.each( {
+ parent: function( elem ) {
+ var parent = elem.parentNode;
+ return parent && parent.nodeType !== 11 ? parent : null;
+ },
+ parents: function( elem ) {
+ return dir( elem, "parentNode" );
+ },
+ parentsUntil: function( elem, i, until ) {
+ return dir( elem, "parentNode", until );
+ },
+ next: function( elem ) {
+ return sibling( elem, "nextSibling" );
+ },
+ prev: function( elem ) {
+ return sibling( elem, "previousSibling" );
+ },
+ nextAll: function( elem ) {
+ return dir( elem, "nextSibling" );
+ },
+ prevAll: function( elem ) {
+ return dir( elem, "previousSibling" );
+ },
+ nextUntil: function( elem, i, until ) {
+ return dir( elem, "nextSibling", until );
+ },
+ prevUntil: function( elem, i, until ) {
+ return dir( elem, "previousSibling", until );
+ },
+ siblings: function( elem ) {
+ return siblings( ( elem.parentNode || {} ).firstChild, elem );
+ },
+ children: function( elem ) {
+ return siblings( elem.firstChild );
+ },
+ contents: function( elem ) {
+ if ( nodeName( elem, "iframe" ) ) {
+ return elem.contentDocument;
+ }
+
+ // Support: IE 9 - 11 only, iOS 7 only, Android Browser <=4.3 only
+ // Treat the template element as a regular one in browsers that
+ // don't support it.
+ if ( nodeName( elem, "template" ) ) {
+ elem = elem.content || elem;
+ }
+
+ return jQuery.merge( [], elem.childNodes );
+ }
+}, function( name, fn ) {
+ jQuery.fn[ name ] = function( until, selector ) {
+ var matched = jQuery.map( this, fn, until );
+
+ if ( name.slice( -5 ) !== "Until" ) {
+ selector = until;
+ }
+
+ if ( selector && typeof selector === "string" ) {
+ matched = jQuery.filter( selector, matched );
+ }
+
+ if ( this.length > 1 ) {
+
+ // Remove duplicates
+ if ( !guaranteedUnique[ name ] ) {
+ jQuery.uniqueSort( matched );
+ }
+
+ // Reverse order for parents* and prev-derivatives
+ if ( rparentsprev.test( name ) ) {
+ matched.reverse();
+ }
+ }
+
+ return this.pushStack( matched );
+ };
+} );
+var rnothtmlwhite = ( /[^\x20\t\r\n\f]+/g );
+
+
+
+// Convert String-formatted options into Object-formatted ones
+function createOptions( options ) {
+ var object = {};
+ jQuery.each( options.match( rnothtmlwhite ) || [], function( _, flag ) {
+ object[ flag ] = true;
+ } );
+ return object;
+}
+
+/*
+ * Create a callback list using the following parameters:
+ *
+ * options: an optional list of space-separated options that will change how
+ * the callback list behaves or a more traditional option object
+ *
+ * By default a callback list will act like an event callback list and can be
+ * "fired" multiple times.
+ *
+ * Possible options:
+ *
+ * once: will ensure the callback list can only be fired once (like a Deferred)
+ *
+ * memory: will keep track of previous values and will call any callback added
+ * after the list has been fired right away with the latest "memorized"
+ * values (like a Deferred)
+ *
+ * unique: will ensure a callback can only be added once (no duplicate in the list)
+ *
+ * stopOnFalse: interrupt callings when a callback returns false
+ *
+ */
+jQuery.Callbacks = function( options ) {
+
+ // Convert options from String-formatted to Object-formatted if needed
+ // (we check in cache first)
+ options = typeof options === "string" ?
+ createOptions( options ) :
+ jQuery.extend( {}, options );
+
+ var // Flag to know if list is currently firing
+ firing,
+
+ // Last fire value for non-forgettable lists
+ memory,
+
+ // Flag to know if list was already fired
+ fired,
+
+ // Flag to prevent firing
+ locked,
+
+ // Actual callback list
+ list = [],
+
+ // Queue of execution data for repeatable lists
+ queue = [],
+
+ // Index of currently firing callback (modified by add/remove as needed)
+ firingIndex = -1,
+
+ // Fire callbacks
+ fire = function() {
+
+ // Enforce single-firing
+ locked = locked || options.once;
+
+ // Execute callbacks for all pending executions,
+ // respecting firingIndex overrides and runtime changes
+ fired = firing = true;
+ for ( ; queue.length; firingIndex = -1 ) {
+ memory = queue.shift();
+ while ( ++firingIndex < list.length ) {
+
+ // Run callback and check for early termination
+ if ( list[ firingIndex ].apply( memory[ 0 ], memory[ 1 ] ) === false &&
+ options.stopOnFalse ) {
+
+ // Jump to end and forget the data so .add doesn't re-fire
+ firingIndex = list.length;
+ memory = false;
+ }
+ }
+ }
+
+ // Forget the data if we're done with it
+ if ( !options.memory ) {
+ memory = false;
+ }
+
+ firing = false;
+
+ // Clean up if we're done firing for good
+ if ( locked ) {
+
+ // Keep an empty list if we have data for future add calls
+ if ( memory ) {
+ list = [];
+
+ // Otherwise, this object is spent
+ } else {
+ list = "";
+ }
+ }
+ },
+
+ // Actual Callbacks object
+ self = {
+
+ // Add a callback or a collection of callbacks to the list
+ add: function() {
+ if ( list ) {
+
+ // If we have memory from a past run, we should fire after adding
+ if ( memory && !firing ) {
+ firingIndex = list.length - 1;
+ queue.push( memory );
+ }
+
+ ( function add( args ) {
+ jQuery.each( args, function( _, arg ) {
+ if ( jQuery.isFunction( arg ) ) {
+ if ( !options.unique || !self.has( arg ) ) {
+ list.push( arg );
+ }
+ } else if ( arg && arg.length && jQuery.type( arg ) !== "string" ) {
+
+ // Inspect recursively
+ add( arg );
+ }
+ } );
+ } )( arguments );
+
+ if ( memory && !firing ) {
+ fire();
+ }
+ }
+ return this;
+ },
+
+ // Remove a callback from the list
+ remove: function() {
+ jQuery.each( arguments, function( _, arg ) {
+ var index;
+ while ( ( index = jQuery.inArray( arg, list, index ) ) > -1 ) {
+ list.splice( index, 1 );
+
+ // Handle firing indexes
+ if ( index <= firingIndex ) {
+ firingIndex--;
+ }
+ }
+ } );
+ return this;
+ },
+
+ // Check if a given callback is in the list.
+ // If no argument is given, return whether or not list has callbacks attached.
+ has: function( fn ) {
+ return fn ?
+ jQuery.inArray( fn, list ) > -1 :
+ list.length > 0;
+ },
+
+ // Remove all callbacks from the list
+ empty: function() {
+ if ( list ) {
+ list = [];
+ }
+ return this;
+ },
+
+ // Disable .fire and .add
+ // Abort any current/pending executions
+ // Clear all callbacks and values
+ disable: function() {
+ locked = queue = [];
+ list = memory = "";
+ return this;
+ },
+ disabled: function() {
+ return !list;
+ },
+
+ // Disable .fire
+ // Also disable .add unless we have memory (since it would have no effect)
+ // Abort any pending executions
+ lock: function() {
+ locked = queue = [];
+ if ( !memory && !firing ) {
+ list = memory = "";
+ }
+ return this;
+ },
+ locked: function() {
+ return !!locked;
+ },
+
+ // Call all callbacks with the given context and arguments
+ fireWith: function( context, args ) {
+ if ( !locked ) {
+ args = args || [];
+ args = [ context, args.slice ? args.slice() : args ];
+ queue.push( args );
+ if ( !firing ) {
+ fire();
+ }
+ }
+ return this;
+ },
+
+ // Call all the callbacks with the given arguments
+ fire: function() {
+ self.fireWith( this, arguments );
+ return this;
+ },
+
+ // To know if the callbacks have already been called at least once
+ fired: function() {
+ return !!fired;
+ }
+ };
+
+ return self;
+};
+
+
+function Identity( v ) {
+ return v;
+}
+function Thrower( ex ) {
+ throw ex;
+}
+
+function adoptValue( value, resolve, reject, noValue ) {
+ var method;
+
+ try {
+
+ // Check for promise aspect first to privilege synchronous behavior
+ if ( value && jQuery.isFunction( ( method = value.promise ) ) ) {
+ method.call( value ).done( resolve ).fail( reject );
+
+ // Other thenables
+ } else if ( value && jQuery.isFunction( ( method = value.then ) ) ) {
+ method.call( value, resolve, reject );
+
+ // Other non-thenables
+ } else {
+
+ // Control `resolve` arguments by letting Array#slice cast boolean `noValue` to integer:
+ // * false: [ value ].slice( 0 ) => resolve( value )
+ // * true: [ value ].slice( 1 ) => resolve()
+ resolve.apply( undefined, [ value ].slice( noValue ) );
+ }
+
+ // For Promises/A+, convert exceptions into rejections
+ // Since jQuery.when doesn't unwrap thenables, we can skip the extra checks appearing in
+ // Deferred#then to conditionally suppress rejection.
+ } catch ( value ) {
+
+ // Support: Android 4.0 only
+ // Strict mode functions invoked without .call/.apply get global-object context
+ reject.apply( undefined, [ value ] );
+ }
+}
+
+jQuery.extend( {
+
+ Deferred: function( func ) {
+ var tuples = [
+
+ // action, add listener, callbacks,
+ // ... .then handlers, argument index, [final state]
+ [ "notify", "progress", jQuery.Callbacks( "memory" ),
+ jQuery.Callbacks( "memory" ), 2 ],
+ [ "resolve", "done", jQuery.Callbacks( "once memory" ),
+ jQuery.Callbacks( "once memory" ), 0, "resolved" ],
+ [ "reject", "fail", jQuery.Callbacks( "once memory" ),
+ jQuery.Callbacks( "once memory" ), 1, "rejected" ]
+ ],
+ state = "pending",
+ promise = {
+ state: function() {
+ return state;
+ },
+ always: function() {
+ deferred.done( arguments ).fail( arguments );
+ return this;
+ },
+ "catch": function( fn ) {
+ return promise.then( null, fn );
+ },
+
+ // Keep pipe for back-compat
+ pipe: function( /* fnDone, fnFail, fnProgress */ ) {
+ var fns = arguments;
+
+ return jQuery.Deferred( function( newDefer ) {
+ jQuery.each( tuples, function( i, tuple ) {
+
+ // Map tuples (progress, done, fail) to arguments (done, fail, progress)
+ var fn = jQuery.isFunction( fns[ tuple[ 4 ] ] ) && fns[ tuple[ 4 ] ];
+
+ // deferred.progress(function() { bind to newDefer or newDefer.notify })
+ // deferred.done(function() { bind to newDefer or newDefer.resolve })
+ // deferred.fail(function() { bind to newDefer or newDefer.reject })
+ deferred[ tuple[ 1 ] ]( function() {
+ var returned = fn && fn.apply( this, arguments );
+ if ( returned && jQuery.isFunction( returned.promise ) ) {
+ returned.promise()
+ .progress( newDefer.notify )
+ .done( newDefer.resolve )
+ .fail( newDefer.reject );
+ } else {
+ newDefer[ tuple[ 0 ] + "With" ](
+ this,
+ fn ? [ returned ] : arguments
+ );
+ }
+ } );
+ } );
+ fns = null;
+ } ).promise();
+ },
+ then: function( onFulfilled, onRejected, onProgress ) {
+ var maxDepth = 0;
+ function resolve( depth, deferred, handler, special ) {
+ return function() {
+ var that = this,
+ args = arguments,
+ mightThrow = function() {
+ var returned, then;
+
+ // Support: Promises/A+ section 2.3.3.3.3
+ // https://promisesaplus.com/#point-59
+ // Ignore double-resolution attempts
+ if ( depth < maxDepth ) {
+ return;
+ }
+
+ returned = handler.apply( that, args );
+
+ // Support: Promises/A+ section 2.3.1
+ // https://promisesaplus.com/#point-48
+ if ( returned === deferred.promise() ) {
+ throw new TypeError( "Thenable self-resolution" );
+ }
+
+ // Support: Promises/A+ sections 2.3.3.1, 3.5
+ // https://promisesaplus.com/#point-54
+ // https://promisesaplus.com/#point-75
+ // Retrieve `then` only once
+ then = returned &&
+
+ // Support: Promises/A+ section 2.3.4
+ // https://promisesaplus.com/#point-64
+ // Only check objects and functions for thenability
+ ( typeof returned === "object" ||
+ typeof returned === "function" ) &&
+ returned.then;
+
+ // Handle a returned thenable
+ if ( jQuery.isFunction( then ) ) {
+
+ // Special processors (notify) just wait for resolution
+ if ( special ) {
+ then.call(
+ returned,
+ resolve( maxDepth, deferred, Identity, special ),
+ resolve( maxDepth, deferred, Thrower, special )
+ );
+
+ // Normal processors (resolve) also hook into progress
+ } else {
+
+ // ...and disregard older resolution values
+ maxDepth++;
+
+ then.call(
+ returned,
+ resolve( maxDepth, deferred, Identity, special ),
+ resolve( maxDepth, deferred, Thrower, special ),
+ resolve( maxDepth, deferred, Identity,
+ deferred.notifyWith )
+ );
+ }
+
+ // Handle all other returned values
+ } else {
+
+ // Only substitute handlers pass on context
+ // and multiple values (non-spec behavior)
+ if ( handler !== Identity ) {
+ that = undefined;
+ args = [ returned ];
+ }
+
+ // Process the value(s)
+ // Default process is resolve
+ ( special || deferred.resolveWith )( that, args );
+ }
+ },
+
+ // Only normal processors (resolve) catch and reject exceptions
+ process = special ?
+ mightThrow :
+ function() {
+ try {
+ mightThrow();
+ } catch ( e ) {
+
+ if ( jQuery.Deferred.exceptionHook ) {
+ jQuery.Deferred.exceptionHook( e,
+ process.stackTrace );
+ }
+
+ // Support: Promises/A+ section 2.3.3.3.4.1
+ // https://promisesaplus.com/#point-61
+ // Ignore post-resolution exceptions
+ if ( depth + 1 >= maxDepth ) {
+
+ // Only substitute handlers pass on context
+ // and multiple values (non-spec behavior)
+ if ( handler !== Thrower ) {
+ that = undefined;
+ args = [ e ];
+ }
+
+ deferred.rejectWith( that, args );
+ }
+ }
+ };
+
+ // Support: Promises/A+ section 2.3.3.3.1
+ // https://promisesaplus.com/#point-57
+ // Re-resolve promises immediately to dodge false rejection from
+ // subsequent errors
+ if ( depth ) {
+ process();
+ } else {
+
+ // Call an optional hook to record the stack, in case of exception
+ // since it's otherwise lost when execution goes async
+ if ( jQuery.Deferred.getStackHook ) {
+ process.stackTrace = jQuery.Deferred.getStackHook();
+ }
+ window.setTimeout( process );
+ }
+ };
+ }
+
+ return jQuery.Deferred( function( newDefer ) {
+
+ // progress_handlers.add( ... )
+ tuples[ 0 ][ 3 ].add(
+ resolve(
+ 0,
+ newDefer,
+ jQuery.isFunction( onProgress ) ?
+ onProgress :
+ Identity,
+ newDefer.notifyWith
+ )
+ );
+
+ // fulfilled_handlers.add( ... )
+ tuples[ 1 ][ 3 ].add(
+ resolve(
+ 0,
+ newDefer,
+ jQuery.isFunction( onFulfilled ) ?
+ onFulfilled :
+ Identity
+ )
+ );
+
+ // rejected_handlers.add( ... )
+ tuples[ 2 ][ 3 ].add(
+ resolve(
+ 0,
+ newDefer,
+ jQuery.isFunction( onRejected ) ?
+ onRejected :
+ Thrower
+ )
+ );
+ } ).promise();
+ },
+
+ // Get a promise for this deferred
+ // If obj is provided, the promise aspect is added to the object
+ promise: function( obj ) {
+ return obj != null ? jQuery.extend( obj, promise ) : promise;
+ }
+ },
+ deferred = {};
+
+ // Add list-specific methods
+ jQuery.each( tuples, function( i, tuple ) {
+ var list = tuple[ 2 ],
+ stateString = tuple[ 5 ];
+
+ // promise.progress = list.add
+ // promise.done = list.add
+ // promise.fail = list.add
+ promise[ tuple[ 1 ] ] = list.add;
+
+ // Handle state
+ if ( stateString ) {
+ list.add(
+ function() {
+
+ // state = "resolved" (i.e., fulfilled)
+ // state = "rejected"
+ state = stateString;
+ },
+
+ // rejected_callbacks.disable
+ // fulfilled_callbacks.disable
+ tuples[ 3 - i ][ 2 ].disable,
+
+ // progress_callbacks.lock
+ tuples[ 0 ][ 2 ].lock
+ );
+ }
+
+ // progress_handlers.fire
+ // fulfilled_handlers.fire
+ // rejected_handlers.fire
+ list.add( tuple[ 3 ].fire );
+
+ // deferred.notify = function() { deferred.notifyWith(...) }
+ // deferred.resolve = function() { deferred.resolveWith(...) }
+ // deferred.reject = function() { deferred.rejectWith(...) }
+ deferred[ tuple[ 0 ] ] = function() {
+ deferred[ tuple[ 0 ] + "With" ]( this === deferred ? undefined : this, arguments );
+ return this;
+ };
+
+ // deferred.notifyWith = list.fireWith
+ // deferred.resolveWith = list.fireWith
+ // deferred.rejectWith = list.fireWith
+ deferred[ tuple[ 0 ] + "With" ] = list.fireWith;
+ } );
+
+ // Make the deferred a promise
+ promise.promise( deferred );
+
+ // Call given func if any
+ if ( func ) {
+ func.call( deferred, deferred );
+ }
+
+ // All done!
+ return deferred;
+ },
+
+ // Deferred helper
+ when: function( singleValue ) {
+ var
+
+ // count of uncompleted subordinates
+ remaining = arguments.length,
+
+ // count of unprocessed arguments
+ i = remaining,
+
+ // subordinate fulfillment data
+ resolveContexts = Array( i ),
+ resolveValues = slice.call( arguments ),
+
+ // the master Deferred
+ master = jQuery.Deferred(),
+
+ // subordinate callback factory
+ updateFunc = function( i ) {
+ return function( value ) {
+ resolveContexts[ i ] = this;
+ resolveValues[ i ] = arguments.length > 1 ? slice.call( arguments ) : value;
+ if ( !( --remaining ) ) {
+ master.resolveWith( resolveContexts, resolveValues );
+ }
+ };
+ };
+
+ // Single- and empty arguments are adopted like Promise.resolve
+ if ( remaining <= 1 ) {
+ adoptValue( singleValue, master.done( updateFunc( i ) ).resolve, master.reject,
+ !remaining );
+
+ // Use .then() to unwrap secondary thenables (cf. gh-3000)
+ if ( master.state() === "pending" ||
+ jQuery.isFunction( resolveValues[ i ] && resolveValues[ i ].then ) ) {
+
+ return master.then();
+ }
+ }
+
+ // Multiple arguments are aggregated like Promise.all array elements
+ while ( i-- ) {
+ adoptValue( resolveValues[ i ], updateFunc( i ), master.reject );
+ }
+
+ return master.promise();
+ }
+} );
+
+
+// These usually indicate a programmer mistake during development,
+// warn about them ASAP rather than swallowing them by default.
+var rerrorNames = /^(Eval|Internal|Range|Reference|Syntax|Type|URI)Error$/;
+
+jQuery.Deferred.exceptionHook = function( error, stack ) {
+
+ // Support: IE 8 - 9 only
+ // Console exists when dev tools are open, which can happen at any time
+ if ( window.console && window.console.warn && error && rerrorNames.test( error.name ) ) {
+ window.console.warn( "jQuery.Deferred exception: " + error.message, error.stack, stack );
+ }
+};
+
+
+
+
+jQuery.readyException = function( error ) {
+ window.setTimeout( function() {
+ throw error;
+ } );
+};
+
+
+
+
+// The deferred used on DOM ready
+var readyList = jQuery.Deferred();
+
+jQuery.fn.ready = function( fn ) {
+
+ readyList
+ .then( fn )
+
+ // Wrap jQuery.readyException in a function so that the lookup
+ // happens at the time of error handling instead of callback
+ // registration.
+ .catch( function( error ) {
+ jQuery.readyException( error );
+ } );
+
+ return this;
+};
+
+jQuery.extend( {
+
+ // Is the DOM ready to be used? Set to true once it occurs.
+ isReady: false,
+
+ // A counter to track how many items to wait for before
+ // the ready event fires. See #6781
+ readyWait: 1,
+
+ // Handle when the DOM is ready
+ ready: function( wait ) {
+
+ // Abort if there are pending holds or we're already ready
+ if ( wait === true ? --jQuery.readyWait : jQuery.isReady ) {
+ return;
+ }
+
+ // Remember that the DOM is ready
+ jQuery.isReady = true;
+
+ // If a normal DOM Ready event fired, decrement, and wait if need be
+ if ( wait !== true && --jQuery.readyWait > 0 ) {
+ return;
+ }
+
+ // If there are functions bound, to execute
+ readyList.resolveWith( document, [ jQuery ] );
+ }
+} );
+
+jQuery.ready.then = readyList.then;
+
+// The ready event handler and self cleanup method
+function completed() {
+ document.removeEventListener( "DOMContentLoaded", completed );
+ window.removeEventListener( "load", completed );
+ jQuery.ready();
+}
+
+// Catch cases where $(document).ready() is called
+// after the browser event has already occurred.
+// Support: IE <=9 - 10 only
+// Older IE sometimes signals "interactive" too soon
+if ( document.readyState === "complete" ||
+ ( document.readyState !== "loading" && !document.documentElement.doScroll ) ) {
+
+ // Handle it asynchronously to allow scripts the opportunity to delay ready
+ window.setTimeout( jQuery.ready );
+
+} else {
+
+ // Use the handy event callback
+ document.addEventListener( "DOMContentLoaded", completed );
+
+ // A fallback to window.onload, that will always work
+ window.addEventListener( "load", completed );
+}
+
+
+
+
+// Multifunctional method to get and set values of a collection
+// The value/s can optionally be executed if it's a function
+var access = function( elems, fn, key, value, chainable, emptyGet, raw ) {
+ var i = 0,
+ len = elems.length,
+ bulk = key == null;
+
+ // Sets many values
+ if ( jQuery.type( key ) === "object" ) {
+ chainable = true;
+ for ( i in key ) {
+ access( elems, fn, i, key[ i ], true, emptyGet, raw );
+ }
+
+ // Sets one value
+ } else if ( value !== undefined ) {
+ chainable = true;
+
+ if ( !jQuery.isFunction( value ) ) {
+ raw = true;
+ }
+
+ if ( bulk ) {
+
+ // Bulk operations run against the entire set
+ if ( raw ) {
+ fn.call( elems, value );
+ fn = null;
+
+ // ...except when executing function values
+ } else {
+ bulk = fn;
+ fn = function( elem, key, value ) {
+ return bulk.call( jQuery( elem ), value );
+ };
+ }
+ }
+
+ if ( fn ) {
+ for ( ; i < len; i++ ) {
+ fn(
+ elems[ i ], key, raw ?
+ value :
+ value.call( elems[ i ], i, fn( elems[ i ], key ) )
+ );
+ }
+ }
+ }
+
+ if ( chainable ) {
+ return elems;
+ }
+
+ // Gets
+ if ( bulk ) {
+ return fn.call( elems );
+ }
+
+ return len ? fn( elems[ 0 ], key ) : emptyGet;
+};
+var acceptData = function( owner ) {
+
+ // Accepts only:
+ // - Node
+ // - Node.ELEMENT_NODE
+ // - Node.DOCUMENT_NODE
+ // - Object
+ // - Any
+ return owner.nodeType === 1 || owner.nodeType === 9 || !( +owner.nodeType );
+};
+
+
+
+
+function Data() {
+ this.expando = jQuery.expando + Data.uid++;
+}
+
+Data.uid = 1;
+
+Data.prototype = {
+
+ cache: function( owner ) {
+
+ // Check if the owner object already has a cache
+ var value = owner[ this.expando ];
+
+ // If not, create one
+ if ( !value ) {
+ value = {};
+
+ // We can accept data for non-element nodes in modern browsers,
+ // but we should not, see #8335.
+ // Always return an empty object.
+ if ( acceptData( owner ) ) {
+
+ // If it is a node unlikely to be stringify-ed or looped over
+ // use plain assignment
+ if ( owner.nodeType ) {
+ owner[ this.expando ] = value;
+
+ // Otherwise secure it in a non-enumerable property
+ // configurable must be true to allow the property to be
+ // deleted when data is removed
+ } else {
+ Object.defineProperty( owner, this.expando, {
+ value: value,
+ configurable: true
+ } );
+ }
+ }
+ }
+
+ return value;
+ },
+ set: function( owner, data, value ) {
+ var prop,
+ cache = this.cache( owner );
+
+ // Handle: [ owner, key, value ] args
+ // Always use camelCase key (gh-2257)
+ if ( typeof data === "string" ) {
+ cache[ jQuery.camelCase( data ) ] = value;
+
+ // Handle: [ owner, { properties } ] args
+ } else {
+
+ // Copy the properties one-by-one to the cache object
+ for ( prop in data ) {
+ cache[ jQuery.camelCase( prop ) ] = data[ prop ];
+ }
+ }
+ return cache;
+ },
+ get: function( owner, key ) {
+ return key === undefined ?
+ this.cache( owner ) :
+
+ // Always use camelCase key (gh-2257)
+ owner[ this.expando ] && owner[ this.expando ][ jQuery.camelCase( key ) ];
+ },
+ access: function( owner, key, value ) {
+
+ // In cases where either:
+ //
+ // 1. No key was specified
+ // 2. A string key was specified, but no value provided
+ //
+ // Take the "read" path and allow the get method to determine
+ // which value to return, respectively either:
+ //
+ // 1. The entire cache object
+ // 2. The data stored at the key
+ //
+ if ( key === undefined ||
+ ( ( key && typeof key === "string" ) && value === undefined ) ) {
+
+ return this.get( owner, key );
+ }
+
+ // When the key is not a string, or both a key and value
+ // are specified, set or extend (existing objects) with either:
+ //
+ // 1. An object of properties
+ // 2. A key and value
+ //
+ this.set( owner, key, value );
+
+ // Since the "set" path can have two possible entry points
+ // return the expected data based on which path was taken[*]
+ return value !== undefined ? value : key;
+ },
+ remove: function( owner, key ) {
+ var i,
+ cache = owner[ this.expando ];
+
+ if ( cache === undefined ) {
+ return;
+ }
+
+ if ( key !== undefined ) {
+
+ // Support array or space separated string of keys
+ if ( Array.isArray( key ) ) {
+
+ // If key is an array of keys...
+ // We always set camelCase keys, so remove that.
+ key = key.map( jQuery.camelCase );
+ } else {
+ key = jQuery.camelCase( key );
+
+ // If a key with the spaces exists, use it.
+ // Otherwise, create an array by matching non-whitespace
+ key = key in cache ?
+ [ key ] :
+ ( key.match( rnothtmlwhite ) || [] );
+ }
+
+ i = key.length;
+
+ while ( i-- ) {
+ delete cache[ key[ i ] ];
+ }
+ }
+
+ // Remove the expando if there's no more data
+ if ( key === undefined || jQuery.isEmptyObject( cache ) ) {
+
+ // Support: Chrome <=35 - 45
+ // Webkit & Blink performance suffers when deleting properties
+ // from DOM nodes, so set to undefined instead
+ // https://bugs.chromium.org/p/chromium/issues/detail?id=378607 (bug restricted)
+ if ( owner.nodeType ) {
+ owner[ this.expando ] = undefined;
+ } else {
+ delete owner[ this.expando ];
+ }
+ }
+ },
+ hasData: function( owner ) {
+ var cache = owner[ this.expando ];
+ return cache !== undefined && !jQuery.isEmptyObject( cache );
+ }
+};
+var dataPriv = new Data();
+
+var dataUser = new Data();
+
+
+
+// Implementation Summary
+//
+// 1. Enforce API surface and semantic compatibility with 1.9.x branch
+// 2. Improve the module's maintainability by reducing the storage
+// paths to a single mechanism.
+// 3. Use the same single mechanism to support "private" and "user" data.
+// 4. _Never_ expose "private" data to user code (TODO: Drop _data, _removeData)
+// 5. Avoid exposing implementation details on user objects (eg. expando properties)
+// 6. Provide a clear path for implementation upgrade to WeakMap in 2014
+
+var rbrace = /^(?:\{[\w\W]*\}|\[[\w\W]*\])$/,
+ rmultiDash = /[A-Z]/g;
+
+function getData( data ) {
+ if ( data === "true" ) {
+ return true;
+ }
+
+ if ( data === "false" ) {
+ return false;
+ }
+
+ if ( data === "null" ) {
+ return null;
+ }
+
+ // Only convert to a number if it doesn't change the string
+ if ( data === +data + "" ) {
+ return +data;
+ }
+
+ if ( rbrace.test( data ) ) {
+ return JSON.parse( data );
+ }
+
+ return data;
+}
+
+function dataAttr( elem, key, data ) {
+ var name;
+
+ // If nothing was found internally, try to fetch any
+ // data from the HTML5 data-* attribute
+ if ( data === undefined && elem.nodeType === 1 ) {
+ name = "data-" + key.replace( rmultiDash, "-$&" ).toLowerCase();
+ data = elem.getAttribute( name );
+
+ if ( typeof data === "string" ) {
+ try {
+ data = getData( data );
+ } catch ( e ) {}
+
+ // Make sure we set the data so it isn't changed later
+ dataUser.set( elem, key, data );
+ } else {
+ data = undefined;
+ }
+ }
+ return data;
+}
+
+jQuery.extend( {
+ hasData: function( elem ) {
+ return dataUser.hasData( elem ) || dataPriv.hasData( elem );
+ },
+
+ data: function( elem, name, data ) {
+ return dataUser.access( elem, name, data );
+ },
+
+ removeData: function( elem, name ) {
+ dataUser.remove( elem, name );
+ },
+
+ // TODO: Now that all calls to _data and _removeData have been replaced
+ // with direct calls to dataPriv methods, these can be deprecated.
+ _data: function( elem, name, data ) {
+ return dataPriv.access( elem, name, data );
+ },
+
+ _removeData: function( elem, name ) {
+ dataPriv.remove( elem, name );
+ }
+} );
+
+jQuery.fn.extend( {
+ data: function( key, value ) {
+ var i, name, data,
+ elem = this[ 0 ],
+ attrs = elem && elem.attributes;
+
+ // Gets all values
+ if ( key === undefined ) {
+ if ( this.length ) {
+ data = dataUser.get( elem );
+
+ if ( elem.nodeType === 1 && !dataPriv.get( elem, "hasDataAttrs" ) ) {
+ i = attrs.length;
+ while ( i-- ) {
+
+ // Support: IE 11 only
+ // The attrs elements can be null (#14894)
+ if ( attrs[ i ] ) {
+ name = attrs[ i ].name;
+ if ( name.indexOf( "data-" ) === 0 ) {
+ name = jQuery.camelCase( name.slice( 5 ) );
+ dataAttr( elem, name, data[ name ] );
+ }
+ }
+ }
+ dataPriv.set( elem, "hasDataAttrs", true );
+ }
+ }
+
+ return data;
+ }
+
+ // Sets multiple values
+ if ( typeof key === "object" ) {
+ return this.each( function() {
+ dataUser.set( this, key );
+ } );
+ }
+
+ return access( this, function( value ) {
+ var data;
+
+ // The calling jQuery object (element matches) is not empty
+ // (and therefore has an element appears at this[ 0 ]) and the
+ // `value` parameter was not undefined. An empty jQuery object
+ // will result in `undefined` for elem = this[ 0 ] which will
+ // throw an exception if an attempt to read a data cache is made.
+ if ( elem && value === undefined ) {
+
+ // Attempt to get data from the cache
+ // The key will always be camelCased in Data
+ data = dataUser.get( elem, key );
+ if ( data !== undefined ) {
+ return data;
+ }
+
+ // Attempt to "discover" the data in
+ // HTML5 custom data-* attrs
+ data = dataAttr( elem, key );
+ if ( data !== undefined ) {
+ return data;
+ }
+
+ // We tried really hard, but the data doesn't exist.
+ return;
+ }
+
+ // Set the data...
+ this.each( function() {
+
+ // We always store the camelCased key
+ dataUser.set( this, key, value );
+ } );
+ }, null, value, arguments.length > 1, null, true );
+ },
+
+ removeData: function( key ) {
+ return this.each( function() {
+ dataUser.remove( this, key );
+ } );
+ }
+} );
+
+
+jQuery.extend( {
+ queue: function( elem, type, data ) {
+ var queue;
+
+ if ( elem ) {
+ type = ( type || "fx" ) + "queue";
+ queue = dataPriv.get( elem, type );
+
+ // Speed up dequeue by getting out quickly if this is just a lookup
+ if ( data ) {
+ if ( !queue || Array.isArray( data ) ) {
+ queue = dataPriv.access( elem, type, jQuery.makeArray( data ) );
+ } else {
+ queue.push( data );
+ }
+ }
+ return queue || [];
+ }
+ },
+
+ dequeue: function( elem, type ) {
+ type = type || "fx";
+
+ var queue = jQuery.queue( elem, type ),
+ startLength = queue.length,
+ fn = queue.shift(),
+ hooks = jQuery._queueHooks( elem, type ),
+ next = function() {
+ jQuery.dequeue( elem, type );
+ };
+
+ // If the fx queue is dequeued, always remove the progress sentinel
+ if ( fn === "inprogress" ) {
+ fn = queue.shift();
+ startLength--;
+ }
+
+ if ( fn ) {
+
+ // Add a progress sentinel to prevent the fx queue from being
+ // automatically dequeued
+ if ( type === "fx" ) {
+ queue.unshift( "inprogress" );
+ }
+
+ // Clear up the last queue stop function
+ delete hooks.stop;
+ fn.call( elem, next, hooks );
+ }
+
+ if ( !startLength && hooks ) {
+ hooks.empty.fire();
+ }
+ },
+
+ // Not public - generate a queueHooks object, or return the current one
+ _queueHooks: function( elem, type ) {
+ var key = type + "queueHooks";
+ return dataPriv.get( elem, key ) || dataPriv.access( elem, key, {
+ empty: jQuery.Callbacks( "once memory" ).add( function() {
+ dataPriv.remove( elem, [ type + "queue", key ] );
+ } )
+ } );
+ }
+} );
+
+jQuery.fn.extend( {
+ queue: function( type, data ) {
+ var setter = 2;
+
+ if ( typeof type !== "string" ) {
+ data = type;
+ type = "fx";
+ setter--;
+ }
+
+ if ( arguments.length < setter ) {
+ return jQuery.queue( this[ 0 ], type );
+ }
+
+ return data === undefined ?
+ this :
+ this.each( function() {
+ var queue = jQuery.queue( this, type, data );
+
+ // Ensure a hooks for this queue
+ jQuery._queueHooks( this, type );
+
+ if ( type === "fx" && queue[ 0 ] !== "inprogress" ) {
+ jQuery.dequeue( this, type );
+ }
+ } );
+ },
+ dequeue: function( type ) {
+ return this.each( function() {
+ jQuery.dequeue( this, type );
+ } );
+ },
+ clearQueue: function( type ) {
+ return this.queue( type || "fx", [] );
+ },
+
+ // Get a promise resolved when queues of a certain type
+ // are emptied (fx is the type by default)
+ promise: function( type, obj ) {
+ var tmp,
+ count = 1,
+ defer = jQuery.Deferred(),
+ elements = this,
+ i = this.length,
+ resolve = function() {
+ if ( !( --count ) ) {
+ defer.resolveWith( elements, [ elements ] );
+ }
+ };
+
+ if ( typeof type !== "string" ) {
+ obj = type;
+ type = undefined;
+ }
+ type = type || "fx";
+
+ while ( i-- ) {
+ tmp = dataPriv.get( elements[ i ], type + "queueHooks" );
+ if ( tmp && tmp.empty ) {
+ count++;
+ tmp.empty.add( resolve );
+ }
+ }
+ resolve();
+ return defer.promise( obj );
+ }
+} );
+var pnum = ( /[+-]?(?:\d*\.|)\d+(?:[eE][+-]?\d+|)/ ).source;
+
+var rcssNum = new RegExp( "^(?:([+-])=|)(" + pnum + ")([a-z%]*)$", "i" );
+
+
+var cssExpand = [ "Top", "Right", "Bottom", "Left" ];
+
+var isHiddenWithinTree = function( elem, el ) {
+
+ // isHiddenWithinTree might be called from jQuery#filter function;
+ // in that case, element will be second argument
+ elem = el || elem;
+
+ // Inline style trumps all
+ return elem.style.display === "none" ||
+ elem.style.display === "" &&
+
+ // Otherwise, check computed style
+ // Support: Firefox <=43 - 45
+ // Disconnected elements can have computed display: none, so first confirm that elem is
+ // in the document.
+ jQuery.contains( elem.ownerDocument, elem ) &&
+
+ jQuery.css( elem, "display" ) === "none";
+ };
+
+var swap = function( elem, options, callback, args ) {
+ var ret, name,
+ old = {};
+
+ // Remember the old values, and insert the new ones
+ for ( name in options ) {
+ old[ name ] = elem.style[ name ];
+ elem.style[ name ] = options[ name ];
+ }
+
+ ret = callback.apply( elem, args || [] );
+
+ // Revert the old values
+ for ( name in options ) {
+ elem.style[ name ] = old[ name ];
+ }
+
+ return ret;
+};
+
+
+
+
+function adjustCSS( elem, prop, valueParts, tween ) {
+ var adjusted,
+ scale = 1,
+ maxIterations = 20,
+ currentValue = tween ?
+ function() {
+ return tween.cur();
+ } :
+ function() {
+ return jQuery.css( elem, prop, "" );
+ },
+ initial = currentValue(),
+ unit = valueParts && valueParts[ 3 ] || ( jQuery.cssNumber[ prop ] ? "" : "px" ),
+
+ // Starting value computation is required for potential unit mismatches
+ initialInUnit = ( jQuery.cssNumber[ prop ] || unit !== "px" && +initial ) &&
+ rcssNum.exec( jQuery.css( elem, prop ) );
+
+ if ( initialInUnit && initialInUnit[ 3 ] !== unit ) {
+
+ // Trust units reported by jQuery.css
+ unit = unit || initialInUnit[ 3 ];
+
+ // Make sure we update the tween properties later on
+ valueParts = valueParts || [];
+
+ // Iteratively approximate from a nonzero starting point
+ initialInUnit = +initial || 1;
+
+ do {
+
+ // If previous iteration zeroed out, double until we get *something*.
+ // Use string for doubling so we don't accidentally see scale as unchanged below
+ scale = scale || ".5";
+
+ // Adjust and apply
+ initialInUnit = initialInUnit / scale;
+ jQuery.style( elem, prop, initialInUnit + unit );
+
+ // Update scale, tolerating zero or NaN from tween.cur()
+ // Break the loop if scale is unchanged or perfect, or if we've just had enough.
+ } while (
+ scale !== ( scale = currentValue() / initial ) && scale !== 1 && --maxIterations
+ );
+ }
+
+ if ( valueParts ) {
+ initialInUnit = +initialInUnit || +initial || 0;
+
+ // Apply relative offset (+=/-=) if specified
+ adjusted = valueParts[ 1 ] ?
+ initialInUnit + ( valueParts[ 1 ] + 1 ) * valueParts[ 2 ] :
+ +valueParts[ 2 ];
+ if ( tween ) {
+ tween.unit = unit;
+ tween.start = initialInUnit;
+ tween.end = adjusted;
+ }
+ }
+ return adjusted;
+}
+
+
+var defaultDisplayMap = {};
+
+function getDefaultDisplay( elem ) {
+ var temp,
+ doc = elem.ownerDocument,
+ nodeName = elem.nodeName,
+ display = defaultDisplayMap[ nodeName ];
+
+ if ( display ) {
+ return display;
+ }
+
+ temp = doc.body.appendChild( doc.createElement( nodeName ) );
+ display = jQuery.css( temp, "display" );
+
+ temp.parentNode.removeChild( temp );
+
+ if ( display === "none" ) {
+ display = "block";
+ }
+ defaultDisplayMap[ nodeName ] = display;
+
+ return display;
+}
+
+function showHide( elements, show ) {
+ var display, elem,
+ values = [],
+ index = 0,
+ length = elements.length;
+
+ // Determine new display value for elements that need to change
+ for ( ; index < length; index++ ) {
+ elem = elements[ index ];
+ if ( !elem.style ) {
+ continue;
+ }
+
+ display = elem.style.display;
+ if ( show ) {
+
+ // Since we force visibility upon cascade-hidden elements, an immediate (and slow)
+ // check is required in this first loop unless we have a nonempty display value (either
+ // inline or about-to-be-restored)
+ if ( display === "none" ) {
+ values[ index ] = dataPriv.get( elem, "display" ) || null;
+ if ( !values[ index ] ) {
+ elem.style.display = "";
+ }
+ }
+ if ( elem.style.display === "" && isHiddenWithinTree( elem ) ) {
+ values[ index ] = getDefaultDisplay( elem );
+ }
+ } else {
+ if ( display !== "none" ) {
+ values[ index ] = "none";
+
+ // Remember what we're overwriting
+ dataPriv.set( elem, "display", display );
+ }
+ }
+ }
+
+ // Set the display of the elements in a second loop to avoid constant reflow
+ for ( index = 0; index < length; index++ ) {
+ if ( values[ index ] != null ) {
+ elements[ index ].style.display = values[ index ];
+ }
+ }
+
+ return elements;
+}
+
+jQuery.fn.extend( {
+ show: function() {
+ return showHide( this, true );
+ },
+ hide: function() {
+ return showHide( this );
+ },
+ toggle: function( state ) {
+ if ( typeof state === "boolean" ) {
+ return state ? this.show() : this.hide();
+ }
+
+ return this.each( function() {
+ if ( isHiddenWithinTree( this ) ) {
+ jQuery( this ).show();
+ } else {
+ jQuery( this ).hide();
+ }
+ } );
+ }
+} );
+var rcheckableType = ( /^(?:checkbox|radio)$/i );
+
+var rtagName = ( /<([a-z][^\/\0>\x20\t\r\n\f]+)/i );
+
+var rscriptType = ( /^$|\/(?:java|ecma)script/i );
+
+
+
+// We have to close these tags to support XHTML (#13200)
+var wrapMap = {
+
+ // Support: IE <=9 only
+ option: [ 1, "<select multiple='multiple'>", "</select>" ],
+
+ // XHTML parsers do not magically insert elements in the
+ // same way that tag soup parsers do. So we cannot shorten
+ // this by omitting <tbody> or other required elements.
+ thead: [ 1, "<table>", "</table>" ],
+ col: [ 2, "<table><colgroup>", "</colgroup></table>" ],
+ tr: [ 2, "<table><tbody>", "</tbody></table>" ],
+ td: [ 3, "<table><tbody><tr>", "</tr></tbody></table>" ],
+
+ _default: [ 0, "", "" ]
+};
+
+// Support: IE <=9 only
+wrapMap.optgroup = wrapMap.option;
+
+wrapMap.tbody = wrapMap.tfoot = wrapMap.colgroup = wrapMap.caption = wrapMap.thead;
+wrapMap.th = wrapMap.td;
+
+
+function getAll( context, tag ) {
+
+ // Support: IE <=9 - 11 only
+ // Use typeof to avoid zero-argument method invocation on host objects (#15151)
+ var ret;
+
+ if ( typeof context.getElementsByTagName !== "undefined" ) {
+ ret = context.getElementsByTagName( tag || "*" );
+
+ } else if ( typeof context.querySelectorAll !== "undefined" ) {
+ ret = context.querySelectorAll( tag || "*" );
+
+ } else {
+ ret = [];
+ }
+
+ if ( tag === undefined || tag && nodeName( context, tag ) ) {
+ return jQuery.merge( [ context ], ret );
+ }
+
+ return ret;
+}
+
+
+// Mark scripts as having already been evaluated
+function setGlobalEval( elems, refElements ) {
+ var i = 0,
+ l = elems.length;
+
+ for ( ; i < l; i++ ) {
+ dataPriv.set(
+ elems[ i ],
+ "globalEval",
+ !refElements || dataPriv.get( refElements[ i ], "globalEval" )
+ );
+ }
+}
+
+
+var rhtml = /<|&#?\w+;/;
+
+function buildFragment( elems, context, scripts, selection, ignored ) {
+ var elem, tmp, tag, wrap, contains, j,
+ fragment = context.createDocumentFragment(),
+ nodes = [],
+ i = 0,
+ l = elems.length;
+
+ for ( ; i < l; i++ ) {
+ elem = elems[ i ];
+
+ if ( elem || elem === 0 ) {
+
+ // Add nodes directly
+ if ( jQuery.type( elem ) === "object" ) {
+
+ // Support: Android <=4.0 only, PhantomJS 1 only
+ // push.apply(_, arraylike) throws on ancient WebKit
+ jQuery.merge( nodes, elem.nodeType ? [ elem ] : elem );
+
+ // Convert non-html into a text node
+ } else if ( !rhtml.test( elem ) ) {
+ nodes.push( context.createTextNode( elem ) );
+
+ // Convert html into DOM nodes
+ } else {
+ tmp = tmp || fragment.appendChild( context.createElement( "div" ) );
+
+ // Deserialize a standard representation
+ tag = ( rtagName.exec( elem ) || [ "", "" ] )[ 1 ].toLowerCase();
+ wrap = wrapMap[ tag ] || wrapMap._default;
+ tmp.innerHTML = wrap[ 1 ] + jQuery.htmlPrefilter( elem ) + wrap[ 2 ];
+
+ // Descend through wrappers to the right content
+ j = wrap[ 0 ];
+ while ( j-- ) {
+ tmp = tmp.lastChild;
+ }
+
+ // Support: Android <=4.0 only, PhantomJS 1 only
+ // push.apply(_, arraylike) throws on ancient WebKit
+ jQuery.merge( nodes, tmp.childNodes );
+
+ // Remember the top-level container
+ tmp = fragment.firstChild;
+
+ // Ensure the created nodes are orphaned (#12392)
+ tmp.textContent = "";
+ }
+ }
+ }
+
+ // Remove wrapper from fragment
+ fragment.textContent = "";
+
+ i = 0;
+ while ( ( elem = nodes[ i++ ] ) ) {
+
+ // Skip elements already in the context collection (trac-4087)
+ if ( selection && jQuery.inArray( elem, selection ) > -1 ) {
+ if ( ignored ) {
+ ignored.push( elem );
+ }
+ continue;
+ }
+
+ contains = jQuery.contains( elem.ownerDocument, elem );
+
+ // Append to fragment
+ tmp = getAll( fragment.appendChild( elem ), "script" );
+
+ // Preserve script evaluation history
+ if ( contains ) {
+ setGlobalEval( tmp );
+ }
+
+ // Capture executables
+ if ( scripts ) {
+ j = 0;
+ while ( ( elem = tmp[ j++ ] ) ) {
+ if ( rscriptType.test( elem.type || "" ) ) {
+ scripts.push( elem );
+ }
+ }
+ }
+ }
+
+ return fragment;
+}
+
+
+( function() {
+ var fragment = document.createDocumentFragment(),
+ div = fragment.appendChild( document.createElement( "div" ) ),
+ input = document.createElement( "input" );
+
+ // Support: Android 4.0 - 4.3 only
+ // Check state lost if the name is set (#11217)
+ // Support: Windows Web Apps (WWA)
+ // `name` and `type` must use .setAttribute for WWA (#14901)
+ input.setAttribute( "type", "radio" );
+ input.setAttribute( "checked", "checked" );
+ input.setAttribute( "name", "t" );
+
+ div.appendChild( input );
+
+ // Support: Android <=4.1 only
+ // Older WebKit doesn't clone checked state correctly in fragments
+ support.checkClone = div.cloneNode( true ).cloneNode( true ).lastChild.checked;
+
+ // Support: IE <=11 only
+ // Make sure textarea (and checkbox) defaultValue is properly cloned
+ div.innerHTML = "<textarea>x</textarea>";
+ support.noCloneChecked = !!div.cloneNode( true ).lastChild.defaultValue;
+} )();
+var documentElement = document.documentElement;
+
+
+
+var
+ rkeyEvent = /^key/,
+ rmouseEvent = /^(?:mouse|pointer|contextmenu|drag|drop)|click/,
+ rtypenamespace = /^([^.]*)(?:\.(.+)|)/;
+
+function returnTrue() {
+ return true;
+}
+
+function returnFalse() {
+ return false;
+}
+
+// Support: IE <=9 only
+// See #13393 for more info
+function safeActiveElement() {
+ try {
+ return document.activeElement;
+ } catch ( err ) { }
+}
+
+function on( elem, types, selector, data, fn, one ) {
+ var origFn, type;
+
+ // Types can be a map of types/handlers
+ if ( typeof types === "object" ) {
+
+ // ( types-Object, selector, data )
+ if ( typeof selector !== "string" ) {
+
+ // ( types-Object, data )
+ data = data || selector;
+ selector = undefined;
+ }
+ for ( type in types ) {
+ on( elem, type, selector, data, types[ type ], one );
+ }
+ return elem;
+ }
+
+ if ( data == null && fn == null ) {
+
+ // ( types, fn )
+ fn = selector;
+ data = selector = undefined;
+ } else if ( fn == null ) {
+ if ( typeof selector === "string" ) {
+
+ // ( types, selector, fn )
+ fn = data;
+ data = undefined;
+ } else {
+
+ // ( types, data, fn )
+ fn = data;
+ data = selector;
+ selector = undefined;
+ }
+ }
+ if ( fn === false ) {
+ fn = returnFalse;
+ } else if ( !fn ) {
+ return elem;
+ }
+
+ if ( one === 1 ) {
+ origFn = fn;
+ fn = function( event ) {
+
+ // Can use an empty set, since event contains the info
+ jQuery().off( event );
+ return origFn.apply( this, arguments );
+ };
+
+ // Use same guid so caller can remove using origFn
+ fn.guid = origFn.guid || ( origFn.guid = jQuery.guid++ );
+ }
+ return elem.each( function() {
+ jQuery.event.add( this, types, fn, data, selector );
+ } );
+}
+
+/*
+ * Helper functions for managing events -- not part of the public interface.
+ * Props to Dean Edwards' addEvent library for many of the ideas.
+ */
+jQuery.event = {
+
+ global: {},
+
+ add: function( elem, types, handler, data, selector ) {
+
+ var handleObjIn, eventHandle, tmp,
+ events, t, handleObj,
+ special, handlers, type, namespaces, origType,
+ elemData = dataPriv.get( elem );
+
+ // Don't attach events to noData or text/comment nodes (but allow plain objects)
+ if ( !elemData ) {
+ return;
+ }
+
+ // Caller can pass in an object of custom data in lieu of the handler
+ if ( handler.handler ) {
+ handleObjIn = handler;
+ handler = handleObjIn.handler;
+ selector = handleObjIn.selector;
+ }
+
+ // Ensure that invalid selectors throw exceptions at attach time
+ // Evaluate against documentElement in case elem is a non-element node (e.g., document)
+ if ( selector ) {
+ jQuery.find.matchesSelector( documentElement, selector );
+ }
+
+ // Make sure that the handler has a unique ID, used to find/remove it later
+ if ( !handler.guid ) {
+ handler.guid = jQuery.guid++;
+ }
+
+ // Init the element's event structure and main handler, if this is the first
+ if ( !( events = elemData.events ) ) {
+ events = elemData.events = {};
+ }
+ if ( !( eventHandle = elemData.handle ) ) {
+ eventHandle = elemData.handle = function( e ) {
+
+ // Discard the second event of a jQuery.event.trigger() and
+ // when an event is called after a page has unloaded
+ return typeof jQuery !== "undefined" && jQuery.event.triggered !== e.type ?
+ jQuery.event.dispatch.apply( elem, arguments ) : undefined;
+ };
+ }
+
+ // Handle multiple events separated by a space
+ types = ( types || "" ).match( rnothtmlwhite ) || [ "" ];
+ t = types.length;
+ while ( t-- ) {
+ tmp = rtypenamespace.exec( types[ t ] ) || [];
+ type = origType = tmp[ 1 ];
+ namespaces = ( tmp[ 2 ] || "" ).split( "." ).sort();
+
+ // There *must* be a type, no attaching namespace-only handlers
+ if ( !type ) {
+ continue;
+ }
+
+ // If event changes its type, use the special event handlers for the changed type
+ special = jQuery.event.special[ type ] || {};
+
+ // If selector defined, determine special event api type, otherwise given type
+ type = ( selector ? special.delegateType : special.bindType ) || type;
+
+ // Update special based on newly reset type
+ special = jQuery.event.special[ type ] || {};
+
+ // handleObj is passed to all event handlers
+ handleObj = jQuery.extend( {
+ type: type,
+ origType: origType,
+ data: data,
+ handler: handler,
+ guid: handler.guid,
+ selector: selector,
+ needsContext: selector && jQuery.expr.match.needsContext.test( selector ),
+ namespace: namespaces.join( "." )
+ }, handleObjIn );
+
+ // Init the event handler queue if we're the first
+ if ( !( handlers = events[ type ] ) ) {
+ handlers = events[ type ] = [];
+ handlers.delegateCount = 0;
+
+ // Only use addEventListener if the special events handler returns false
+ if ( !special.setup ||
+ special.setup.call( elem, data, namespaces, eventHandle ) === false ) {
+
+ if ( elem.addEventListener ) {
+ elem.addEventListener( type, eventHandle );
+ }
+ }
+ }
+
+ if ( special.add ) {
+ special.add.call( elem, handleObj );
+
+ if ( !handleObj.handler.guid ) {
+ handleObj.handler.guid = handler.guid;
+ }
+ }
+
+ // Add to the element's handler list, delegates in front
+ if ( selector ) {
+ handlers.splice( handlers.delegateCount++, 0, handleObj );
+ } else {
+ handlers.push( handleObj );
+ }
+
+ // Keep track of which events have ever been used, for event optimization
+ jQuery.event.global[ type ] = true;
+ }
+
+ },
+
+ // Detach an event or set of events from an element
+ remove: function( elem, types, handler, selector, mappedTypes ) {
+
+ var j, origCount, tmp,
+ events, t, handleObj,
+ special, handlers, type, namespaces, origType,
+ elemData = dataPriv.hasData( elem ) && dataPriv.get( elem );
+
+ if ( !elemData || !( events = elemData.events ) ) {
+ return;
+ }
+
+ // Once for each type.namespace in types; type may be omitted
+ types = ( types || "" ).match( rnothtmlwhite ) || [ "" ];
+ t = types.length;
+ while ( t-- ) {
+ tmp = rtypenamespace.exec( types[ t ] ) || [];
+ type = origType = tmp[ 1 ];
+ namespaces = ( tmp[ 2 ] || "" ).split( "." ).sort();
+
+ // Unbind all events (on this namespace, if provided) for the element
+ if ( !type ) {
+ for ( type in events ) {
+ jQuery.event.remove( elem, type + types[ t ], handler, selector, true );
+ }
+ continue;
+ }
+
+ special = jQuery.event.special[ type ] || {};
+ type = ( selector ? special.delegateType : special.bindType ) || type;
+ handlers = events[ type ] || [];
+ tmp = tmp[ 2 ] &&
+ new RegExp( "(^|\\.)" + namespaces.join( "\\.(?:.*\\.|)" ) + "(\\.|$)" );
+
+ // Remove matching events
+ origCount = j = handlers.length;
+ while ( j-- ) {
+ handleObj = handlers[ j ];
+
+ if ( ( mappedTypes || origType === handleObj.origType ) &&
+ ( !handler || handler.guid === handleObj.guid ) &&
+ ( !tmp || tmp.test( handleObj.namespace ) ) &&
+ ( !selector || selector === handleObj.selector ||
+ selector === "**" && handleObj.selector ) ) {
+ handlers.splice( j, 1 );
+
+ if ( handleObj.selector ) {
+ handlers.delegateCount--;
+ }
+ if ( special.remove ) {
+ special.remove.call( elem, handleObj );
+ }
+ }
+ }
+
+ // Remove generic event handler if we removed something and no more handlers exist
+ // (avoids potential for endless recursion during removal of special event handlers)
+ if ( origCount && !handlers.length ) {
+ if ( !special.teardown ||
+ special.teardown.call( elem, namespaces, elemData.handle ) === false ) {
+
+ jQuery.removeEvent( elem, type, elemData.handle );
+ }
+
+ delete events[ type ];
+ }
+ }
+
+ // Remove data and the expando if it's no longer used
+ if ( jQuery.isEmptyObject( events ) ) {
+ dataPriv.remove( elem, "handle events" );
+ }
+ },
+
+ dispatch: function( nativeEvent ) {
+
+ // Make a writable jQuery.Event from the native event object
+ var event = jQuery.event.fix( nativeEvent );
+
+ var i, j, ret, matched, handleObj, handlerQueue,
+ args = new Array( arguments.length ),
+ handlers = ( dataPriv.get( this, "events" ) || {} )[ event.type ] || [],
+ special = jQuery.event.special[ event.type ] || {};
+
+ // Use the fix-ed jQuery.Event rather than the (read-only) native event
+ args[ 0 ] = event;
+
+ for ( i = 1; i < arguments.length; i++ ) {
+ args[ i ] = arguments[ i ];
+ }
+
+ event.delegateTarget = this;
+
+ // Call the preDispatch hook for the mapped type, and let it bail if desired
+ if ( special.preDispatch && special.preDispatch.call( this, event ) === false ) {
+ return;
+ }
+
+ // Determine handlers
+ handlerQueue = jQuery.event.handlers.call( this, event, handlers );
+
+ // Run delegates first; they may want to stop propagation beneath us
+ i = 0;
+ while ( ( matched = handlerQueue[ i++ ] ) && !event.isPropagationStopped() ) {
+ event.currentTarget = matched.elem;
+
+ j = 0;
+ while ( ( handleObj = matched.handlers[ j++ ] ) &&
+ !event.isImmediatePropagationStopped() ) {
+
+ // Triggered event must either 1) have no namespace, or 2) have namespace(s)
+ // a subset or equal to those in the bound event (both can have no namespace).
+ if ( !event.rnamespace || event.rnamespace.test( handleObj.namespace ) ) {
+
+ event.handleObj = handleObj;
+ event.data = handleObj.data;
+
+ ret = ( ( jQuery.event.special[ handleObj.origType ] || {} ).handle ||
+ handleObj.handler ).apply( matched.elem, args );
+
+ if ( ret !== undefined ) {
+ if ( ( event.result = ret ) === false ) {
+ event.preventDefault();
+ event.stopPropagation();
+ }
+ }
+ }
+ }
+ }
+
+ // Call the postDispatch hook for the mapped type
+ if ( special.postDispatch ) {
+ special.postDispatch.call( this, event );
+ }
+
+ return event.result;
+ },
+
+ handlers: function( event, handlers ) {
+ var i, handleObj, sel, matchedHandlers, matchedSelectors,
+ handlerQueue = [],
+ delegateCount = handlers.delegateCount,
+ cur = event.target;
+
+ // Find delegate handlers
+ if ( delegateCount &&
+
+ // Support: IE <=9
+ // Black-hole SVG <use> instance trees (trac-13180)
+ cur.nodeType &&
+
+ // Support: Firefox <=42
+ // Suppress spec-violating clicks indicating a non-primary pointer button (trac-3861)
+ // https://www.w3.org/TR/DOM-Level-3-Events/#event-type-click
+ // Support: IE 11 only
+ // ...but not arrow key "clicks" of radio inputs, which can have `button` -1 (gh-2343)
+ !( event.type === "click" && event.button >= 1 ) ) {
+
+ for ( ; cur !== this; cur = cur.parentNode || this ) {
+
+ // Don't check non-elements (#13208)
+ // Don't process clicks on disabled elements (#6911, #8165, #11382, #11764)
+ if ( cur.nodeType === 1 && !( event.type === "click" && cur.disabled === true ) ) {
+ matchedHandlers = [];
+ matchedSelectors = {};
+ for ( i = 0; i < delegateCount; i++ ) {
+ handleObj = handlers[ i ];
+
+ // Don't conflict with Object.prototype properties (#13203)
+ sel = handleObj.selector + " ";
+
+ if ( matchedSelectors[ sel ] === undefined ) {
+ matchedSelectors[ sel ] = handleObj.needsContext ?
+ jQuery( sel, this ).index( cur ) > -1 :
+ jQuery.find( sel, this, null, [ cur ] ).length;
+ }
+ if ( matchedSelectors[ sel ] ) {
+ matchedHandlers.push( handleObj );
+ }
+ }
+ if ( matchedHandlers.length ) {
+ handlerQueue.push( { elem: cur, handlers: matchedHandlers } );
+ }
+ }
+ }
+ }
+
+ // Add the remaining (directly-bound) handlers
+ cur = this;
+ if ( delegateCount < handlers.length ) {
+ handlerQueue.push( { elem: cur, handlers: handlers.slice( delegateCount ) } );
+ }
+
+ return handlerQueue;
+ },
+
+ addProp: function( name, hook ) {
+ Object.defineProperty( jQuery.Event.prototype, name, {
+ enumerable: true,
+ configurable: true,
+
+ get: jQuery.isFunction( hook ) ?
+ function() {
+ if ( this.originalEvent ) {
+ return hook( this.originalEvent );
+ }
+ } :
+ function() {
+ if ( this.originalEvent ) {
+ return this.originalEvent[ name ];
+ }
+ },
+
+ set: function( value ) {
+ Object.defineProperty( this, name, {
+ enumerable: true,
+ configurable: true,
+ writable: true,
+ value: value
+ } );
+ }
+ } );
+ },
+
+ fix: function( originalEvent ) {
+ return originalEvent[ jQuery.expando ] ?
+ originalEvent :
+ new jQuery.Event( originalEvent );
+ },
+
+ special: {
+ load: {
+
+ // Prevent triggered image.load events from bubbling to window.load
+ noBubble: true
+ },
+ focus: {
+
+ // Fire native event if possible so blur/focus sequence is correct
+ trigger: function() {
+ if ( this !== safeActiveElement() && this.focus ) {
+ this.focus();
+ return false;
+ }
+ },
+ delegateType: "focusin"
+ },
+ blur: {
+ trigger: function() {
+ if ( this === safeActiveElement() && this.blur ) {
+ this.blur();
+ return false;
+ }
+ },
+ delegateType: "focusout"
+ },
+ click: {
+
+ // For checkbox, fire native event so checked state will be right
+ trigger: function() {
+ if ( this.type === "checkbox" && this.click && nodeName( this, "input" ) ) {
+ this.click();
+ return false;
+ }
+ },
+
+ // For cross-browser consistency, don't fire native .click() on links
+ _default: function( event ) {
+ return nodeName( event.target, "a" );
+ }
+ },
+
+ beforeunload: {
+ postDispatch: function( event ) {
+
+ // Support: Firefox 20+
+ // Firefox doesn't alert if the returnValue field is not set.
+ if ( event.result !== undefined && event.originalEvent ) {
+ event.originalEvent.returnValue = event.result;
+ }
+ }
+ }
+ }
+};
+
+jQuery.removeEvent = function( elem, type, handle ) {
+
+ // This "if" is needed for plain objects
+ if ( elem.removeEventListener ) {
+ elem.removeEventListener( type, handle );
+ }
+};
+
+jQuery.Event = function( src, props ) {
+
+ // Allow instantiation without the 'new' keyword
+ if ( !( this instanceof jQuery.Event ) ) {
+ return new jQuery.Event( src, props );
+ }
+
+ // Event object
+ if ( src && src.type ) {
+ this.originalEvent = src;
+ this.type = src.type;
+
+ // Events bubbling up the document may have been marked as prevented
+ // by a handler lower down the tree; reflect the correct value.
+ this.isDefaultPrevented = src.defaultPrevented ||
+ src.defaultPrevented === undefined &&
+
+ // Support: Android <=2.3 only
+ src.returnValue === false ?
+ returnTrue :
+ returnFalse;
+
+ // Create target properties
+ // Support: Safari <=6 - 7 only
+ // Target should not be a text node (#504, #13143)
+ this.target = ( src.target && src.target.nodeType === 3 ) ?
+ src.target.parentNode :
+ src.target;
+
+ this.currentTarget = src.currentTarget;
+ this.relatedTarget = src.relatedTarget;
+
+ // Event type
+ } else {
+ this.type = src;
+ }
+
+ // Put explicitly provided properties onto the event object
+ if ( props ) {
+ jQuery.extend( this, props );
+ }
+
+ // Create a timestamp if incoming event doesn't have one
+ this.timeStamp = src && src.timeStamp || jQuery.now();
+
+ // Mark it as fixed
+ this[ jQuery.expando ] = true;
+};
+
+// jQuery.Event is based on DOM3 Events as specified by the ECMAScript Language Binding
+// https://www.w3.org/TR/2003/WD-DOM-Level-3-Events-20030331/ecma-script-binding.html
+jQuery.Event.prototype = {
+ constructor: jQuery.Event,
+ isDefaultPrevented: returnFalse,
+ isPropagationStopped: returnFalse,
+ isImmediatePropagationStopped: returnFalse,
+ isSimulated: false,
+
+ preventDefault: function() {
+ var e = this.originalEvent;
+
+ this.isDefaultPrevented = returnTrue;
+
+ if ( e && !this.isSimulated ) {
+ e.preventDefault();
+ }
+ },
+ stopPropagation: function() {
+ var e = this.originalEvent;
+
+ this.isPropagationStopped = returnTrue;
+
+ if ( e && !this.isSimulated ) {
+ e.stopPropagation();
+ }
+ },
+ stopImmediatePropagation: function() {
+ var e = this.originalEvent;
+
+ this.isImmediatePropagationStopped = returnTrue;
+
+ if ( e && !this.isSimulated ) {
+ e.stopImmediatePropagation();
+ }
+
+ this.stopPropagation();
+ }
+};
+
+// Includes all common event props including KeyEvent and MouseEvent specific props
+jQuery.each( {
+ altKey: true,
+ bubbles: true,
+ cancelable: true,
+ changedTouches: true,
+ ctrlKey: true,
+ detail: true,
+ eventPhase: true,
+ metaKey: true,
+ pageX: true,
+ pageY: true,
+ shiftKey: true,
+ view: true,
+ "char": true,
+ charCode: true,
+ key: true,
+ keyCode: true,
+ button: true,
+ buttons: true,
+ clientX: true,
+ clientY: true,
+ offsetX: true,
+ offsetY: true,
+ pointerId: true,
+ pointerType: true,
+ screenX: true,
+ screenY: true,
+ targetTouches: true,
+ toElement: true,
+ touches: true,
+
+ which: function( event ) {
+ var button = event.button;
+
+ // Add which for key events
+ if ( event.which == null && rkeyEvent.test( event.type ) ) {
+ return event.charCode != null ? event.charCode : event.keyCode;
+ }
+
+ // Add which for click: 1 === left; 2 === middle; 3 === right
+ if ( !event.which && button !== undefined && rmouseEvent.test( event.type ) ) {
+ if ( button & 1 ) {
+ return 1;
+ }
+
+ if ( button & 2 ) {
+ return 3;
+ }
+
+ if ( button & 4 ) {
+ return 2;
+ }
+
+ return 0;
+ }
+
+ return event.which;
+ }
+}, jQuery.event.addProp );
+
+// Create mouseenter/leave events using mouseover/out and event-time checks
+// so that event delegation works in jQuery.
+// Do the same for pointerenter/pointerleave and pointerover/pointerout
+//
+// Support: Safari 7 only
+// Safari sends mouseenter too often; see:
+// https://bugs.chromium.org/p/chromium/issues/detail?id=470258
+// for the description of the bug (it existed in older Chrome versions as well).
+jQuery.each( {
+ mouseenter: "mouseover",
+ mouseleave: "mouseout",
+ pointerenter: "pointerover",
+ pointerleave: "pointerout"
+}, function( orig, fix ) {
+ jQuery.event.special[ orig ] = {
+ delegateType: fix,
+ bindType: fix,
+
+ handle: function( event ) {
+ var ret,
+ target = this,
+ related = event.relatedTarget,
+ handleObj = event.handleObj;
+
+ // For mouseenter/leave call the handler if related is outside the target.
+ // NB: No relatedTarget if the mouse left/entered the browser window
+ if ( !related || ( related !== target && !jQuery.contains( target, related ) ) ) {
+ event.type = handleObj.origType;
+ ret = handleObj.handler.apply( this, arguments );
+ event.type = fix;
+ }
+ return ret;
+ }
+ };
+} );
+
+jQuery.fn.extend( {
+
+ on: function( types, selector, data, fn ) {
+ return on( this, types, selector, data, fn );
+ },
+ one: function( types, selector, data, fn ) {
+ return on( this, types, selector, data, fn, 1 );
+ },
+ off: function( types, selector, fn ) {
+ var handleObj, type;
+ if ( types && types.preventDefault && types.handleObj ) {
+
+ // ( event ) dispatched jQuery.Event
+ handleObj = types.handleObj;
+ jQuery( types.delegateTarget ).off(
+ handleObj.namespace ?
+ handleObj.origType + "." + handleObj.namespace :
+ handleObj.origType,
+ handleObj.selector,
+ handleObj.handler
+ );
+ return this;
+ }
+ if ( typeof types === "object" ) {
+
+ // ( types-object [, selector] )
+ for ( type in types ) {
+ this.off( type, selector, types[ type ] );
+ }
+ return this;
+ }
+ if ( selector === false || typeof selector === "function" ) {
+
+ // ( types [, fn] )
+ fn = selector;
+ selector = undefined;
+ }
+ if ( fn === false ) {
+ fn = returnFalse;
+ }
+ return this.each( function() {
+ jQuery.event.remove( this, types, fn, selector );
+ } );
+ }
+} );
+
+
+var
+
+ /* eslint-disable max-len */
+
+ // See https://github.com/eslint/eslint/issues/3229
+ rxhtmlTag = /<(?!area|br|col|embed|hr|img|input|link|meta|param)(([a-z][^\/\0>\x20\t\r\n\f]*)[^>]*)\/>/gi,
+
+ /* eslint-enable */
+
+ // Support: IE <=10 - 11, Edge 12 - 13
+ // In IE/Edge using regex groups here causes severe slowdowns.
+ // See https://connect.microsoft.com/IE/feedback/details/1736512/
+ rnoInnerhtml = /<script|<style|<link/i,
+
+ // checked="checked" or checked
+ rchecked = /checked\s*(?:[^=]|=\s*.checked.)/i,
+ rscriptTypeMasked = /^true\/(.*)/,
+ rcleanScript = /^\s*<!(?:\[CDATA\[|--)|(?:\]\]|--)>\s*$/g;
+
+// Prefer a tbody over its parent table for containing new rows
+function manipulationTarget( elem, content ) {
+ if ( nodeName( elem, "table" ) &&
+ nodeName( content.nodeType !== 11 ? content : content.firstChild, "tr" ) ) {
+
+ return jQuery( ">tbody", elem )[ 0 ] || elem;
+ }
+
+ return elem;
+}
+
+// Replace/restore the type attribute of script elements for safe DOM manipulation
+function disableScript( elem ) {
+ elem.type = ( elem.getAttribute( "type" ) !== null ) + "/" + elem.type;
+ return elem;
+}
+function restoreScript( elem ) {
+ var match = rscriptTypeMasked.exec( elem.type );
+
+ if ( match ) {
+ elem.type = match[ 1 ];
+ } else {
+ elem.removeAttribute( "type" );
+ }
+
+ return elem;
+}
+
+function cloneCopyEvent( src, dest ) {
+ var i, l, type, pdataOld, pdataCur, udataOld, udataCur, events;
+
+ if ( dest.nodeType !== 1 ) {
+ return;
+ }
+
+ // 1. Copy private data: events, handlers, etc.
+ if ( dataPriv.hasData( src ) ) {
+ pdataOld = dataPriv.access( src );
+ pdataCur = dataPriv.set( dest, pdataOld );
+ events = pdataOld.events;
+
+ if ( events ) {
+ delete pdataCur.handle;
+ pdataCur.events = {};
+
+ for ( type in events ) {
+ for ( i = 0, l = events[ type ].length; i < l; i++ ) {
+ jQuery.event.add( dest, type, events[ type ][ i ] );
+ }
+ }
+ }
+ }
+
+ // 2. Copy user data
+ if ( dataUser.hasData( src ) ) {
+ udataOld = dataUser.access( src );
+ udataCur = jQuery.extend( {}, udataOld );
+
+ dataUser.set( dest, udataCur );
+ }
+}
+
+// Fix IE bugs, see support tests
+function fixInput( src, dest ) {
+ var nodeName = dest.nodeName.toLowerCase();
+
+ // Fails to persist the checked state of a cloned checkbox or radio button.
+ if ( nodeName === "input" && rcheckableType.test( src.type ) ) {
+ dest.checked = src.checked;
+
+ // Fails to return the selected option to the default selected state when cloning options
+ } else if ( nodeName === "input" || nodeName === "textarea" ) {
+ dest.defaultValue = src.defaultValue;
+ }
+}
+
+function domManip( collection, args, callback, ignored ) {
+
+ // Flatten any nested arrays
+ args = concat.apply( [], args );
+
+ var fragment, first, scripts, hasScripts, node, doc,
+ i = 0,
+ l = collection.length,
+ iNoClone = l - 1,
+ value = args[ 0 ],
+ isFunction = jQuery.isFunction( value );
+
+ // We can't cloneNode fragments that contain checked, in WebKit
+ if ( isFunction ||
+ ( l > 1 && typeof value === "string" &&
+ !support.checkClone && rchecked.test( value ) ) ) {
+ return collection.each( function( index ) {
+ var self = collection.eq( index );
+ if ( isFunction ) {
+ args[ 0 ] = value.call( this, index, self.html() );
+ }
+ domManip( self, args, callback, ignored );
+ } );
+ }
+
+ if ( l ) {
+ fragment = buildFragment( args, collection[ 0 ].ownerDocument, false, collection, ignored );
+ first = fragment.firstChild;
+
+ if ( fragment.childNodes.length === 1 ) {
+ fragment = first;
+ }
+
+ // Require either new content or an interest in ignored elements to invoke the callback
+ if ( first || ignored ) {
+ scripts = jQuery.map( getAll( fragment, "script" ), disableScript );
+ hasScripts = scripts.length;
+
+ // Use the original fragment for the last item
+ // instead of the first because it can end up
+ // being emptied incorrectly in certain situations (#8070).
+ for ( ; i < l; i++ ) {
+ node = fragment;
+
+ if ( i !== iNoClone ) {
+ node = jQuery.clone( node, true, true );
+
+ // Keep references to cloned scripts for later restoration
+ if ( hasScripts ) {
+
+ // Support: Android <=4.0 only, PhantomJS 1 only
+ // push.apply(_, arraylike) throws on ancient WebKit
+ jQuery.merge( scripts, getAll( node, "script" ) );
+ }
+ }
+
+ callback.call( collection[ i ], node, i );
+ }
+
+ if ( hasScripts ) {
+ doc = scripts[ scripts.length - 1 ].ownerDocument;
+
+ // Reenable scripts
+ jQuery.map( scripts, restoreScript );
+
+ // Evaluate executable scripts on first document insertion
+ for ( i = 0; i < hasScripts; i++ ) {
+ node = scripts[ i ];
+ if ( rscriptType.test( node.type || "" ) &&
+ !dataPriv.access( node, "globalEval" ) &&
+ jQuery.contains( doc, node ) ) {
+
+ if ( node.src ) {
+
+ // Optional AJAX dependency, but won't run scripts if not present
+ if ( jQuery._evalUrl ) {
+ jQuery._evalUrl( node.src );
+ }
+ } else {
+ DOMEval( node.textContent.replace( rcleanScript, "" ), doc );
+ }
+ }
+ }
+ }
+ }
+ }
+
+ return collection;
+}
+
+function remove( elem, selector, keepData ) {
+ var node,
+ nodes = selector ? jQuery.filter( selector, elem ) : elem,
+ i = 0;
+
+ for ( ; ( node = nodes[ i ] ) != null; i++ ) {
+ if ( !keepData && node.nodeType === 1 ) {
+ jQuery.cleanData( getAll( node ) );
+ }
+
+ if ( node.parentNode ) {
+ if ( keepData && jQuery.contains( node.ownerDocument, node ) ) {
+ setGlobalEval( getAll( node, "script" ) );
+ }
+ node.parentNode.removeChild( node );
+ }
+ }
+
+ return elem;
+}
+
+jQuery.extend( {
+ htmlPrefilter: function( html ) {
+ return html.replace( rxhtmlTag, "<$1></$2>" );
+ },
+
+ clone: function( elem, dataAndEvents, deepDataAndEvents ) {
+ var i, l, srcElements, destElements,
+ clone = elem.cloneNode( true ),
+ inPage = jQuery.contains( elem.ownerDocument, elem );
+
+ // Fix IE cloning issues
+ if ( !support.noCloneChecked && ( elem.nodeType === 1 || elem.nodeType === 11 ) &&
+ !jQuery.isXMLDoc( elem ) ) {
+
+ // We eschew Sizzle here for performance reasons: https://jsperf.com/getall-vs-sizzle/2
+ destElements = getAll( clone );
+ srcElements = getAll( elem );
+
+ for ( i = 0, l = srcElements.length; i < l; i++ ) {
+ fixInput( srcElements[ i ], destElements[ i ] );
+ }
+ }
+
+ // Copy the events from the original to the clone
+ if ( dataAndEvents ) {
+ if ( deepDataAndEvents ) {
+ srcElements = srcElements || getAll( elem );
+ destElements = destElements || getAll( clone );
+
+ for ( i = 0, l = srcElements.length; i < l; i++ ) {
+ cloneCopyEvent( srcElements[ i ], destElements[ i ] );
+ }
+ } else {
+ cloneCopyEvent( elem, clone );
+ }
+ }
+
+ // Preserve script evaluation history
+ destElements = getAll( clone, "script" );
+ if ( destElements.length > 0 ) {
+ setGlobalEval( destElements, !inPage && getAll( elem, "script" ) );
+ }
+
+ // Return the cloned set
+ return clone;
+ },
+
+ cleanData: function( elems ) {
+ var data, elem, type,
+ special = jQuery.event.special,
+ i = 0;
+
+ for ( ; ( elem = elems[ i ] ) !== undefined; i++ ) {
+ if ( acceptData( elem ) ) {
+ if ( ( data = elem[ dataPriv.expando ] ) ) {
+ if ( data.events ) {
+ for ( type in data.events ) {
+ if ( special[ type ] ) {
+ jQuery.event.remove( elem, type );
+
+ // This is a shortcut to avoid jQuery.event.remove's overhead
+ } else {
+ jQuery.removeEvent( elem, type, data.handle );
+ }
+ }
+ }
+
+ // Support: Chrome <=35 - 45+
+ // Assign undefined instead of using delete, see Data#remove
+ elem[ dataPriv.expando ] = undefined;
+ }
+ if ( elem[ dataUser.expando ] ) {
+
+ // Support: Chrome <=35 - 45+
+ // Assign undefined instead of using delete, see Data#remove
+ elem[ dataUser.expando ] = undefined;
+ }
+ }
+ }
+ }
+} );
+
+jQuery.fn.extend( {
+ detach: function( selector ) {
+ return remove( this, selector, true );
+ },
+
+ remove: function( selector ) {
+ return remove( this, selector );
+ },
+
+ text: function( value ) {
+ return access( this, function( value ) {
+ return value === undefined ?
+ jQuery.text( this ) :
+ this.empty().each( function() {
+ if ( this.nodeType === 1 || this.nodeType === 11 || this.nodeType === 9 ) {
+ this.textContent = value;
+ }
+ } );
+ }, null, value, arguments.length );
+ },
+
+ append: function() {
+ return domManip( this, arguments, function( elem ) {
+ if ( this.nodeType === 1 || this.nodeType === 11 || this.nodeType === 9 ) {
+ var target = manipulationTarget( this, elem );
+ target.appendChild( elem );
+ }
+ } );
+ },
+
+ prepend: function() {
+ return domManip( this, arguments, function( elem ) {
+ if ( this.nodeType === 1 || this.nodeType === 11 || this.nodeType === 9 ) {
+ var target = manipulationTarget( this, elem );
+ target.insertBefore( elem, target.firstChild );
+ }
+ } );
+ },
+
+ before: function() {
+ return domManip( this, arguments, function( elem ) {
+ if ( this.parentNode ) {
+ this.parentNode.insertBefore( elem, this );
+ }
+ } );
+ },
+
+ after: function() {
+ return domManip( this, arguments, function( elem ) {
+ if ( this.parentNode ) {
+ this.parentNode.insertBefore( elem, this.nextSibling );
+ }
+ } );
+ },
+
+ empty: function() {
+ var elem,
+ i = 0;
+
+ for ( ; ( elem = this[ i ] ) != null; i++ ) {
+ if ( elem.nodeType === 1 ) {
+
+ // Prevent memory leaks
+ jQuery.cleanData( getAll( elem, false ) );
+
+ // Remove any remaining nodes
+ elem.textContent = "";
+ }
+ }
+
+ return this;
+ },
+
+ clone: function( dataAndEvents, deepDataAndEvents ) {
+ dataAndEvents = dataAndEvents == null ? false : dataAndEvents;
+ deepDataAndEvents = deepDataAndEvents == null ? dataAndEvents : deepDataAndEvents;
+
+ return this.map( function() {
+ return jQuery.clone( this, dataAndEvents, deepDataAndEvents );
+ } );
+ },
+
+ html: function( value ) {
+ return access( this, function( value ) {
+ var elem = this[ 0 ] || {},
+ i = 0,
+ l = this.length;
+
+ if ( value === undefined && elem.nodeType === 1 ) {
+ return elem.innerHTML;
+ }
+
+ // See if we can take a shortcut and just use innerHTML
+ if ( typeof value === "string" && !rnoInnerhtml.test( value ) &&
+ !wrapMap[ ( rtagName.exec( value ) || [ "", "" ] )[ 1 ].toLowerCase() ] ) {
+
+ value = jQuery.htmlPrefilter( value );
+
+ try {
+ for ( ; i < l; i++ ) {
+ elem = this[ i ] || {};
+
+ // Remove element nodes and prevent memory leaks
+ if ( elem.nodeType === 1 ) {
+ jQuery.cleanData( getAll( elem, false ) );
+ elem.innerHTML = value;
+ }
+ }
+
+ elem = 0;
+
+ // If using innerHTML throws an exception, use the fallback method
+ } catch ( e ) {}
+ }
+
+ if ( elem ) {
+ this.empty().append( value );
+ }
+ }, null, value, arguments.length );
+ },
+
+ replaceWith: function() {
+ var ignored = [];
+
+ // Make the changes, replacing each non-ignored context element with the new content
+ return domManip( this, arguments, function( elem ) {
+ var parent = this.parentNode;
+
+ if ( jQuery.inArray( this, ignored ) < 0 ) {
+ jQuery.cleanData( getAll( this ) );
+ if ( parent ) {
+ parent.replaceChild( elem, this );
+ }
+ }
+
+ // Force callback invocation
+ }, ignored );
+ }
+} );
+
+jQuery.each( {
+ appendTo: "append",
+ prependTo: "prepend",
+ insertBefore: "before",
+ insertAfter: "after",
+ replaceAll: "replaceWith"
+}, function( name, original ) {
+ jQuery.fn[ name ] = function( selector ) {
+ var elems,
+ ret = [],
+ insert = jQuery( selector ),
+ last = insert.length - 1,
+ i = 0;
+
+ for ( ; i <= last; i++ ) {
+ elems = i === last ? this : this.clone( true );
+ jQuery( insert[ i ] )[ original ]( elems );
+
+ // Support: Android <=4.0 only, PhantomJS 1 only
+ // .get() because push.apply(_, arraylike) throws on ancient WebKit
+ push.apply( ret, elems.get() );
+ }
+
+ return this.pushStack( ret );
+ };
+} );
+var rmargin = ( /^margin/ );
+
+var rnumnonpx = new RegExp( "^(" + pnum + ")(?!px)[a-z%]+$", "i" );
+
+var getStyles = function( elem ) {
+
+ // Support: IE <=11 only, Firefox <=30 (#15098, #14150)
+ // IE throws on elements created in popups
+ // FF meanwhile throws on frame elements through "defaultView.getComputedStyle"
+ var view = elem.ownerDocument.defaultView;
+
+ if ( !view || !view.opener ) {
+ view = window;
+ }
+
+ return view.getComputedStyle( elem );
+ };
+
+
+
+( function() {
+
+ // Executing both pixelPosition & boxSizingReliable tests require only one layout
+ // so they're executed at the same time to save the second computation.
+ function computeStyleTests() {
+
+ // This is a singleton, we need to execute it only once
+ if ( !div ) {
+ return;
+ }
+
+ div.style.cssText =
+ "box-sizing:border-box;" +
+ "position:relative;display:block;" +
+ "margin:auto;border:1px;padding:1px;" +
+ "top:1%;width:50%";
+ div.innerHTML = "";
+ documentElement.appendChild( container );
+
+ var divStyle = window.getComputedStyle( div );
+ pixelPositionVal = divStyle.top !== "1%";
+
+ // Support: Android 4.0 - 4.3 only, Firefox <=3 - 44
+ reliableMarginLeftVal = divStyle.marginLeft === "2px";
+ boxSizingReliableVal = divStyle.width === "4px";
+
+ // Support: Android 4.0 - 4.3 only
+ // Some styles come back with percentage values, even though they shouldn't
+ div.style.marginRight = "50%";
+ pixelMarginRightVal = divStyle.marginRight === "4px";
+
+ documentElement.removeChild( container );
+
+ // Nullify the div so it wouldn't be stored in the memory and
+ // it will also be a sign that checks already performed
+ div = null;
+ }
+
+ var pixelPositionVal, boxSizingReliableVal, pixelMarginRightVal, reliableMarginLeftVal,
+ container = document.createElement( "div" ),
+ div = document.createElement( "div" );
+
+ // Finish early in limited (non-browser) environments
+ if ( !div.style ) {
+ return;
+ }
+
+ // Support: IE <=9 - 11 only
+ // Style of cloned element affects source element cloned (#8908)
+ div.style.backgroundClip = "content-box";
+ div.cloneNode( true ).style.backgroundClip = "";
+ support.clearCloneStyle = div.style.backgroundClip === "content-box";
+
+ container.style.cssText = "border:0;width:8px;height:0;top:0;left:-9999px;" +
+ "padding:0;margin-top:1px;position:absolute";
+ container.appendChild( div );
+
+ jQuery.extend( support, {
+ pixelPosition: function() {
+ computeStyleTests();
+ return pixelPositionVal;
+ },
+ boxSizingReliable: function() {
+ computeStyleTests();
+ return boxSizingReliableVal;
+ },
+ pixelMarginRight: function() {
+ computeStyleTests();
+ return pixelMarginRightVal;
+ },
+ reliableMarginLeft: function() {
+ computeStyleTests();
+ return reliableMarginLeftVal;
+ }
+ } );
+} )();
+
+
+function curCSS( elem, name, computed ) {
+ var width, minWidth, maxWidth, ret,
+
+ // Support: Firefox 51+
+ // Retrieving style before computed somehow
+ // fixes an issue with getting wrong values
+ // on detached elements
+ style = elem.style;
+
+ computed = computed || getStyles( elem );
+
+ // getPropertyValue is needed for:
+ // .css('filter') (IE 9 only, #12537)
+ // .css('--customProperty) (#3144)
+ if ( computed ) {
+ ret = computed.getPropertyValue( name ) || computed[ name ];
+
+ if ( ret === "" && !jQuery.contains( elem.ownerDocument, elem ) ) {
+ ret = jQuery.style( elem, name );
+ }
+
+ // A tribute to the "awesome hack by Dean Edwards"
+ // Android Browser returns percentage for some values,
+ // but width seems to be reliably pixels.
+ // This is against the CSSOM draft spec:
+ // https://drafts.csswg.org/cssom/#resolved-values
+ if ( !support.pixelMarginRight() && rnumnonpx.test( ret ) && rmargin.test( name ) ) {
+
+ // Remember the original values
+ width = style.width;
+ minWidth = style.minWidth;
+ maxWidth = style.maxWidth;
+
+ // Put in the new values to get a computed value out
+ style.minWidth = style.maxWidth = style.width = ret;
+ ret = computed.width;
+
+ // Revert the changed values
+ style.width = width;
+ style.minWidth = minWidth;
+ style.maxWidth = maxWidth;
+ }
+ }
+
+ return ret !== undefined ?
+
+ // Support: IE <=9 - 11 only
+ // IE returns zIndex value as an integer.
+ ret + "" :
+ ret;
+}
+
+
+function addGetHookIf( conditionFn, hookFn ) {
+
+ // Define the hook, we'll check on the first run if it's really needed.
+ return {
+ get: function() {
+ if ( conditionFn() ) {
+
+ // Hook not needed (or it's not possible to use it due
+ // to missing dependency), remove it.
+ delete this.get;
+ return;
+ }
+
+ // Hook needed; redefine it so that the support test is not executed again.
+ return ( this.get = hookFn ).apply( this, arguments );
+ }
+ };
+}
+
+
+var
+
+ // Swappable if display is none or starts with table
+ // except "table", "table-cell", or "table-caption"
+ // See here for display values: https://developer.mozilla.org/en-US/docs/CSS/display
+ rdisplayswap = /^(none|table(?!-c[ea]).+)/,
+ rcustomProp = /^--/,
+ cssShow = { position: "absolute", visibility: "hidden", display: "block" },
+ cssNormalTransform = {
+ letterSpacing: "0",
+ fontWeight: "400"
+ },
+
+ cssPrefixes = [ "Webkit", "Moz", "ms" ],
+ emptyStyle = document.createElement( "div" ).style;
+
+// Return a css property mapped to a potentially vendor prefixed property
+function vendorPropName( name ) {
+
+ // Shortcut for names that are not vendor prefixed
+ if ( name in emptyStyle ) {
+ return name;
+ }
+
+ // Check for vendor prefixed names
+ var capName = name[ 0 ].toUpperCase() + name.slice( 1 ),
+ i = cssPrefixes.length;
+
+ while ( i-- ) {
+ name = cssPrefixes[ i ] + capName;
+ if ( name in emptyStyle ) {
+ return name;
+ }
+ }
+}
+
+// Return a property mapped along what jQuery.cssProps suggests or to
+// a vendor prefixed property.
+function finalPropName( name ) {
+ var ret = jQuery.cssProps[ name ];
+ if ( !ret ) {
+ ret = jQuery.cssProps[ name ] = vendorPropName( name ) || name;
+ }
+ return ret;
+}
+
+function setPositiveNumber( elem, value, subtract ) {
+
+ // Any relative (+/-) values have already been
+ // normalized at this point
+ var matches = rcssNum.exec( value );
+ return matches ?
+
+ // Guard against undefined "subtract", e.g., when used as in cssHooks
+ Math.max( 0, matches[ 2 ] - ( subtract || 0 ) ) + ( matches[ 3 ] || "px" ) :
+ value;
+}
+
+function augmentWidthOrHeight( elem, name, extra, isBorderBox, styles ) {
+ var i,
+ val = 0;
+
+ // If we already have the right measurement, avoid augmentation
+ if ( extra === ( isBorderBox ? "border" : "content" ) ) {
+ i = 4;
+
+ // Otherwise initialize for horizontal or vertical properties
+ } else {
+ i = name === "width" ? 1 : 0;
+ }
+
+ for ( ; i < 4; i += 2 ) {
+
+ // Both box models exclude margin, so add it if we want it
+ if ( extra === "margin" ) {
+ val += jQuery.css( elem, extra + cssExpand[ i ], true, styles );
+ }
+
+ if ( isBorderBox ) {
+
+ // border-box includes padding, so remove it if we want content
+ if ( extra === "content" ) {
+ val -= jQuery.css( elem, "padding" + cssExpand[ i ], true, styles );
+ }
+
+ // At this point, extra isn't border nor margin, so remove border
+ if ( extra !== "margin" ) {
+ val -= jQuery.css( elem, "border" + cssExpand[ i ] + "Width", true, styles );
+ }
+ } else {
+
+ // At this point, extra isn't content, so add padding
+ val += jQuery.css( elem, "padding" + cssExpand[ i ], true, styles );
+
+ // At this point, extra isn't content nor padding, so add border
+ if ( extra !== "padding" ) {
+ val += jQuery.css( elem, "border" + cssExpand[ i ] + "Width", true, styles );
+ }
+ }
+ }
+
+ return val;
+}
+
+function getWidthOrHeight( elem, name, extra ) {
+
+ // Start with computed style
+ var valueIsBorderBox,
+ styles = getStyles( elem ),
+ val = curCSS( elem, name, styles ),
+ isBorderBox = jQuery.css( elem, "boxSizing", false, styles ) === "border-box";
+
+ // Computed unit is not pixels. Stop here and return.
+ if ( rnumnonpx.test( val ) ) {
+ return val;
+ }
+
+ // Check for style in case a browser which returns unreliable values
+ // for getComputedStyle silently falls back to the reliable elem.style
+ valueIsBorderBox = isBorderBox &&
+ ( support.boxSizingReliable() || val === elem.style[ name ] );
+
+ // Fall back to offsetWidth/Height when value is "auto"
+ // This happens for inline elements with no explicit setting (gh-3571)
+ if ( val === "auto" ) {
+ val = elem[ "offset" + name[ 0 ].toUpperCase() + name.slice( 1 ) ];
+ }
+
+ // Normalize "", auto, and prepare for extra
+ val = parseFloat( val ) || 0;
+
+ // Use the active box-sizing model to add/subtract irrelevant styles
+ return ( val +
+ augmentWidthOrHeight(
+ elem,
+ name,
+ extra || ( isBorderBox ? "border" : "content" ),
+ valueIsBorderBox,
+ styles
+ )
+ ) + "px";
+}
+
+jQuery.extend( {
+
+ // Add in style property hooks for overriding the default
+ // behavior of getting and setting a style property
+ cssHooks: {
+ opacity: {
+ get: function( elem, computed ) {
+ if ( computed ) {
+
+ // We should always get a number back from opacity
+ var ret = curCSS( elem, "opacity" );
+ return ret === "" ? "1" : ret;
+ }
+ }
+ }
+ },
+
+ // Don't automatically add "px" to these possibly-unitless properties
+ cssNumber: {
+ "animationIterationCount": true,
+ "columnCount": true,
+ "fillOpacity": true,
+ "flexGrow": true,
+ "flexShrink": true,
+ "fontWeight": true,
+ "lineHeight": true,
+ "opacity": true,
+ "order": true,
+ "orphans": true,
+ "widows": true,
+ "zIndex": true,
+ "zoom": true
+ },
+
+ // Add in properties whose names you wish to fix before
+ // setting or getting the value
+ cssProps: {
+ "float": "cssFloat"
+ },
+
+ // Get and set the style property on a DOM Node
+ style: function( elem, name, value, extra ) {
+
+ // Don't set styles on text and comment nodes
+ if ( !elem || elem.nodeType === 3 || elem.nodeType === 8 || !elem.style ) {
+ return;
+ }
+
+ // Make sure that we're working with the right name
+ var ret, type, hooks,
+ origName = jQuery.camelCase( name ),
+ isCustomProp = rcustomProp.test( name ),
+ style = elem.style;
+
+ // Make sure that we're working with the right name. We don't
+ // want to query the value if it is a CSS custom property
+ // since they are user-defined.
+ if ( !isCustomProp ) {
+ name = finalPropName( origName );
+ }
+
+ // Gets hook for the prefixed version, then unprefixed version
+ hooks = jQuery.cssHooks[ name ] || jQuery.cssHooks[ origName ];
+
+ // Check if we're setting a value
+ if ( value !== undefined ) {
+ type = typeof value;
+
+ // Convert "+=" or "-=" to relative numbers (#7345)
+ if ( type === "string" && ( ret = rcssNum.exec( value ) ) && ret[ 1 ] ) {
+ value = adjustCSS( elem, name, ret );
+
+ // Fixes bug #9237
+ type = "number";
+ }
+
+ // Make sure that null and NaN values aren't set (#7116)
+ if ( value == null || value !== value ) {
+ return;
+ }
+
+ // If a number was passed in, add the unit (except for certain CSS properties)
+ if ( type === "number" ) {
+ value += ret && ret[ 3 ] || ( jQuery.cssNumber[ origName ] ? "" : "px" );
+ }
+
+ // background-* props affect original clone's values
+ if ( !support.clearCloneStyle && value === "" && name.indexOf( "background" ) === 0 ) {
+ style[ name ] = "inherit";
+ }
+
+ // If a hook was provided, use that value, otherwise just set the specified value
+ if ( !hooks || !( "set" in hooks ) ||
+ ( value = hooks.set( elem, value, extra ) ) !== undefined ) {
+
+ if ( isCustomProp ) {
+ style.setProperty( name, value );
+ } else {
+ style[ name ] = value;
+ }
+ }
+
+ } else {
+
+ // If a hook was provided get the non-computed value from there
+ if ( hooks && "get" in hooks &&
+ ( ret = hooks.get( elem, false, extra ) ) !== undefined ) {
+
+ return ret;
+ }
+
+ // Otherwise just get the value from the style object
+ return style[ name ];
+ }
+ },
+
+ css: function( elem, name, extra, styles ) {
+ var val, num, hooks,
+ origName = jQuery.camelCase( name ),
+ isCustomProp = rcustomProp.test( name );
+
+ // Make sure that we're working with the right name. We don't
+ // want to modify the value if it is a CSS custom property
+ // since they are user-defined.
+ if ( !isCustomProp ) {
+ name = finalPropName( origName );
+ }
+
+ // Try prefixed name followed by the unprefixed name
+ hooks = jQuery.cssHooks[ name ] || jQuery.cssHooks[ origName ];
+
+ // If a hook was provided get the computed value from there
+ if ( hooks && "get" in hooks ) {
+ val = hooks.get( elem, true, extra );
+ }
+
+ // Otherwise, if a way to get the computed value exists, use that
+ if ( val === undefined ) {
+ val = curCSS( elem, name, styles );
+ }
+
+ // Convert "normal" to computed value
+ if ( val === "normal" && name in cssNormalTransform ) {
+ val = cssNormalTransform[ name ];
+ }
+
+ // Make numeric if forced or a qualifier was provided and val looks numeric
+ if ( extra === "" || extra ) {
+ num = parseFloat( val );
+ return extra === true || isFinite( num ) ? num || 0 : val;
+ }
+
+ return val;
+ }
+} );
+
+jQuery.each( [ "height", "width" ], function( i, name ) {
+ jQuery.cssHooks[ name ] = {
+ get: function( elem, computed, extra ) {
+ if ( computed ) {
+
+ // Certain elements can have dimension info if we invisibly show them
+ // but it must have a current display style that would benefit
+ return rdisplayswap.test( jQuery.css( elem, "display" ) ) &&
+
+ // Support: Safari 8+
+ // Table columns in Safari have non-zero offsetWidth & zero
+ // getBoundingClientRect().width unless display is changed.
+ // Support: IE <=11 only
+ // Running getBoundingClientRect on a disconnected node
+ // in IE throws an error.
+ ( !elem.getClientRects().length || !elem.getBoundingClientRect().width ) ?
+ swap( elem, cssShow, function() {
+ return getWidthOrHeight( elem, name, extra );
+ } ) :
+ getWidthOrHeight( elem, name, extra );
+ }
+ },
+
+ set: function( elem, value, extra ) {
+ var matches,
+ styles = extra && getStyles( elem ),
+ subtract = extra && augmentWidthOrHeight(
+ elem,
+ name,
+ extra,
+ jQuery.css( elem, "boxSizing", false, styles ) === "border-box",
+ styles
+ );
+
+ // Convert to pixels if value adjustment is needed
+ if ( subtract && ( matches = rcssNum.exec( value ) ) &&
+ ( matches[ 3 ] || "px" ) !== "px" ) {
+
+ elem.style[ name ] = value;
+ value = jQuery.css( elem, name );
+ }
+
+ return setPositiveNumber( elem, value, subtract );
+ }
+ };
+} );
+
+jQuery.cssHooks.marginLeft = addGetHookIf( support.reliableMarginLeft,
+ function( elem, computed ) {
+ if ( computed ) {
+ return ( parseFloat( curCSS( elem, "marginLeft" ) ) ||
+ elem.getBoundingClientRect().left -
+ swap( elem, { marginLeft: 0 }, function() {
+ return elem.getBoundingClientRect().left;
+ } )
+ ) + "px";
+ }
+ }
+);
+
+// These hooks are used by animate to expand properties
+jQuery.each( {
+ margin: "",
+ padding: "",
+ border: "Width"
+}, function( prefix, suffix ) {
+ jQuery.cssHooks[ prefix + suffix ] = {
+ expand: function( value ) {
+ var i = 0,
+ expanded = {},
+
+ // Assumes a single number if not a string
+ parts = typeof value === "string" ? value.split( " " ) : [ value ];
+
+ for ( ; i < 4; i++ ) {
+ expanded[ prefix + cssExpand[ i ] + suffix ] =
+ parts[ i ] || parts[ i - 2 ] || parts[ 0 ];
+ }
+
+ return expanded;
+ }
+ };
+
+ if ( !rmargin.test( prefix ) ) {
+ jQuery.cssHooks[ prefix + suffix ].set = setPositiveNumber;
+ }
+} );
+
+jQuery.fn.extend( {
+ css: function( name, value ) {
+ return access( this, function( elem, name, value ) {
+ var styles, len,
+ map = {},
+ i = 0;
+
+ if ( Array.isArray( name ) ) {
+ styles = getStyles( elem );
+ len = name.length;
+
+ for ( ; i < len; i++ ) {
+ map[ name[ i ] ] = jQuery.css( elem, name[ i ], false, styles );
+ }
+
+ return map;
+ }
+
+ return value !== undefined ?
+ jQuery.style( elem, name, value ) :
+ jQuery.css( elem, name );
+ }, name, value, arguments.length > 1 );
+ }
+} );
+
+
+function Tween( elem, options, prop, end, easing ) {
+ return new Tween.prototype.init( elem, options, prop, end, easing );
+}
+jQuery.Tween = Tween;
+
+Tween.prototype = {
+ constructor: Tween,
+ init: function( elem, options, prop, end, easing, unit ) {
+ this.elem = elem;
+ this.prop = prop;
+ this.easing = easing || jQuery.easing._default;
+ this.options = options;
+ this.start = this.now = this.cur();
+ this.end = end;
+ this.unit = unit || ( jQuery.cssNumber[ prop ] ? "" : "px" );
+ },
+ cur: function() {
+ var hooks = Tween.propHooks[ this.prop ];
+
+ return hooks && hooks.get ?
+ hooks.get( this ) :
+ Tween.propHooks._default.get( this );
+ },
+ run: function( percent ) {
+ var eased,
+ hooks = Tween.propHooks[ this.prop ];
+
+ if ( this.options.duration ) {
+ this.pos = eased = jQuery.easing[ this.easing ](
+ percent, this.options.duration * percent, 0, 1, this.options.duration
+ );
+ } else {
+ this.pos = eased = percent;
+ }
+ this.now = ( this.end - this.start ) * eased + this.start;
+
+ if ( this.options.step ) {
+ this.options.step.call( this.elem, this.now, this );
+ }
+
+ if ( hooks && hooks.set ) {
+ hooks.set( this );
+ } else {
+ Tween.propHooks._default.set( this );
+ }
+ return this;
+ }
+};
+
+Tween.prototype.init.prototype = Tween.prototype;
+
+Tween.propHooks = {
+ _default: {
+ get: function( tween ) {
+ var result;
+
+ // Use a property on the element directly when it is not a DOM element,
+ // or when there is no matching style property that exists.
+ if ( tween.elem.nodeType !== 1 ||
+ tween.elem[ tween.prop ] != null && tween.elem.style[ tween.prop ] == null ) {
+ return tween.elem[ tween.prop ];
+ }
+
+ // Passing an empty string as a 3rd parameter to .css will automatically
+ // attempt a parseFloat and fallback to a string if the parse fails.
+ // Simple values such as "10px" are parsed to Float;
+ // complex values such as "rotate(1rad)" are returned as-is.
+ result = jQuery.css( tween.elem, tween.prop, "" );
+
+ // Empty strings, null, undefined and "auto" are converted to 0.
+ return !result || result === "auto" ? 0 : result;
+ },
+ set: function( tween ) {
+
+ // Use step hook for back compat.
+ // Use cssHook if its there.
+ // Use .style if available and use plain properties where available.
+ if ( jQuery.fx.step[ tween.prop ] ) {
+ jQuery.fx.step[ tween.prop ]( tween );
+ } else if ( tween.elem.nodeType === 1 &&
+ ( tween.elem.style[ jQuery.cssProps[ tween.prop ] ] != null ||
+ jQuery.cssHooks[ tween.prop ] ) ) {
+ jQuery.style( tween.elem, tween.prop, tween.now + tween.unit );
+ } else {
+ tween.elem[ tween.prop ] = tween.now;
+ }
+ }
+ }
+};
+
+// Support: IE <=9 only
+// Panic based approach to setting things on disconnected nodes
+Tween.propHooks.scrollTop = Tween.propHooks.scrollLeft = {
+ set: function( tween ) {
+ if ( tween.elem.nodeType && tween.elem.parentNode ) {
+ tween.elem[ tween.prop ] = tween.now;
+ }
+ }
+};
+
+jQuery.easing = {
+ linear: function( p ) {
+ return p;
+ },
+ swing: function( p ) {
+ return 0.5 - Math.cos( p * Math.PI ) / 2;
+ },
+ _default: "swing"
+};
+
+jQuery.fx = Tween.prototype.init;
+
+// Back compat <1.8 extension point
+jQuery.fx.step = {};
+
+
+
+
+var
+ fxNow, inProgress,
+ rfxtypes = /^(?:toggle|show|hide)$/,
+ rrun = /queueHooks$/;
+
+function schedule() {
+ if ( inProgress ) {
+ if ( document.hidden === false && window.requestAnimationFrame ) {
+ window.requestAnimationFrame( schedule );
+ } else {
+ window.setTimeout( schedule, jQuery.fx.interval );
+ }
+
+ jQuery.fx.tick();
+ }
+}
+
+// Animations created synchronously will run synchronously
+function createFxNow() {
+ window.setTimeout( function() {
+ fxNow = undefined;
+ } );
+ return ( fxNow = jQuery.now() );
+}
+
+// Generate parameters to create a standard animation
+function genFx( type, includeWidth ) {
+ var which,
+ i = 0,
+ attrs = { height: type };
+
+ // If we include width, step value is 1 to do all cssExpand values,
+ // otherwise step value is 2 to skip over Left and Right
+ includeWidth = includeWidth ? 1 : 0;
+ for ( ; i < 4; i += 2 - includeWidth ) {
+ which = cssExpand[ i ];
+ attrs[ "margin" + which ] = attrs[ "padding" + which ] = type;
+ }
+
+ if ( includeWidth ) {
+ attrs.opacity = attrs.width = type;
+ }
+
+ return attrs;
+}
+
+function createTween( value, prop, animation ) {
+ var tween,
+ collection = ( Animation.tweeners[ prop ] || [] ).concat( Animation.tweeners[ "*" ] ),
+ index = 0,
+ length = collection.length;
+ for ( ; index < length; index++ ) {
+ if ( ( tween = collection[ index ].call( animation, prop, value ) ) ) {
+
+ // We're done with this property
+ return tween;
+ }
+ }
+}
+
+function defaultPrefilter( elem, props, opts ) {
+ var prop, value, toggle, hooks, oldfire, propTween, restoreDisplay, display,
+ isBox = "width" in props || "height" in props,
+ anim = this,
+ orig = {},
+ style = elem.style,
+ hidden = elem.nodeType && isHiddenWithinTree( elem ),
+ dataShow = dataPriv.get( elem, "fxshow" );
+
+ // Queue-skipping animations hijack the fx hooks
+ if ( !opts.queue ) {
+ hooks = jQuery._queueHooks( elem, "fx" );
+ if ( hooks.unqueued == null ) {
+ hooks.unqueued = 0;
+ oldfire = hooks.empty.fire;
+ hooks.empty.fire = function() {
+ if ( !hooks.unqueued ) {
+ oldfire();
+ }
+ };
+ }
+ hooks.unqueued++;
+
+ anim.always( function() {
+
+ // Ensure the complete handler is called before this completes
+ anim.always( function() {
+ hooks.unqueued--;
+ if ( !jQuery.queue( elem, "fx" ).length ) {
+ hooks.empty.fire();
+ }
+ } );
+ } );
+ }
+
+ // Detect show/hide animations
+ for ( prop in props ) {
+ value = props[ prop ];
+ if ( rfxtypes.test( value ) ) {
+ delete props[ prop ];
+ toggle = toggle || value === "toggle";
+ if ( value === ( hidden ? "hide" : "show" ) ) {
+
+ // Pretend to be hidden if this is a "show" and
+ // there is still data from a stopped show/hide
+ if ( value === "show" && dataShow && dataShow[ prop ] !== undefined ) {
+ hidden = true;
+
+ // Ignore all other no-op show/hide data
+ } else {
+ continue;
+ }
+ }
+ orig[ prop ] = dataShow && dataShow[ prop ] || jQuery.style( elem, prop );
+ }
+ }
+
+ // Bail out if this is a no-op like .hide().hide()
+ propTween = !jQuery.isEmptyObject( props );
+ if ( !propTween && jQuery.isEmptyObject( orig ) ) {
+ return;
+ }
+
+ // Restrict "overflow" and "display" styles during box animations
+ if ( isBox && elem.nodeType === 1 ) {
+
+ // Support: IE <=9 - 11, Edge 12 - 13
+ // Record all 3 overflow attributes because IE does not infer the shorthand
+ // from identically-valued overflowX and overflowY
+ opts.overflow = [ style.overflow, style.overflowX, style.overflowY ];
+
+ // Identify a display type, preferring old show/hide data over the CSS cascade
+ restoreDisplay = dataShow && dataShow.display;
+ if ( restoreDisplay == null ) {
+ restoreDisplay = dataPriv.get( elem, "display" );
+ }
+ display = jQuery.css( elem, "display" );
+ if ( display === "none" ) {
+ if ( restoreDisplay ) {
+ display = restoreDisplay;
+ } else {
+
+ // Get nonempty value(s) by temporarily forcing visibility
+ showHide( [ elem ], true );
+ restoreDisplay = elem.style.display || restoreDisplay;
+ display = jQuery.css( elem, "display" );
+ showHide( [ elem ] );
+ }
+ }
+
+ // Animate inline elements as inline-block
+ if ( display === "inline" || display === "inline-block" && restoreDisplay != null ) {
+ if ( jQuery.css( elem, "float" ) === "none" ) {
+
+ // Restore the original display value at the end of pure show/hide animations
+ if ( !propTween ) {
+ anim.done( function() {
+ style.display = restoreDisplay;
+ } );
+ if ( restoreDisplay == null ) {
+ display = style.display;
+ restoreDisplay = display === "none" ? "" : display;
+ }
+ }
+ style.display = "inline-block";
+ }
+ }
+ }
+
+ if ( opts.overflow ) {
+ style.overflow = "hidden";
+ anim.always( function() {
+ style.overflow = opts.overflow[ 0 ];
+ style.overflowX = opts.overflow[ 1 ];
+ style.overflowY = opts.overflow[ 2 ];
+ } );
+ }
+
+ // Implement show/hide animations
+ propTween = false;
+ for ( prop in orig ) {
+
+ // General show/hide setup for this element animation
+ if ( !propTween ) {
+ if ( dataShow ) {
+ if ( "hidden" in dataShow ) {
+ hidden = dataShow.hidden;
+ }
+ } else {
+ dataShow = dataPriv.access( elem, "fxshow", { display: restoreDisplay } );
+ }
+
+ // Store hidden/visible for toggle so `.stop().toggle()` "reverses"
+ if ( toggle ) {
+ dataShow.hidden = !hidden;
+ }
+
+ // Show elements before animating them
+ if ( hidden ) {
+ showHide( [ elem ], true );
+ }
+
+ /* eslint-disable no-loop-func */
+
+ anim.done( function() {
+
+ /* eslint-enable no-loop-func */
+
+ // The final step of a "hide" animation is actually hiding the element
+ if ( !hidden ) {
+ showHide( [ elem ] );
+ }
+ dataPriv.remove( elem, "fxshow" );
+ for ( prop in orig ) {
+ jQuery.style( elem, prop, orig[ prop ] );
+ }
+ } );
+ }
+
+ // Per-property setup
+ propTween = createTween( hidden ? dataShow[ prop ] : 0, prop, anim );
+ if ( !( prop in dataShow ) ) {
+ dataShow[ prop ] = propTween.start;
+ if ( hidden ) {
+ propTween.end = propTween.start;
+ propTween.start = 0;
+ }
+ }
+ }
+}
+
+function propFilter( props, specialEasing ) {
+ var index, name, easing, value, hooks;
+
+ // camelCase, specialEasing and expand cssHook pass
+ for ( index in props ) {
+ name = jQuery.camelCase( index );
+ easing = specialEasing[ name ];
+ value = props[ index ];
+ if ( Array.isArray( value ) ) {
+ easing = value[ 1 ];
+ value = props[ index ] = value[ 0 ];
+ }
+
+ if ( index !== name ) {
+ props[ name ] = value;
+ delete props[ index ];
+ }
+
+ hooks = jQuery.cssHooks[ name ];
+ if ( hooks && "expand" in hooks ) {
+ value = hooks.expand( value );
+ delete props[ name ];
+
+ // Not quite $.extend, this won't overwrite existing keys.
+ // Reusing 'index' because we have the correct "name"
+ for ( index in value ) {
+ if ( !( index in props ) ) {
+ props[ index ] = value[ index ];
+ specialEasing[ index ] = easing;
+ }
+ }
+ } else {
+ specialEasing[ name ] = easing;
+ }
+ }
+}
+
+function Animation( elem, properties, options ) {
+ var result,
+ stopped,
+ index = 0,
+ length = Animation.prefilters.length,
+ deferred = jQuery.Deferred().always( function() {
+
+ // Don't match elem in the :animated selector
+ delete tick.elem;
+ } ),
+ tick = function() {
+ if ( stopped ) {
+ return false;
+ }
+ var currentTime = fxNow || createFxNow(),
+ remaining = Math.max( 0, animation.startTime + animation.duration - currentTime ),
+
+ // Support: Android 2.3 only
+ // Archaic crash bug won't allow us to use `1 - ( 0.5 || 0 )` (#12497)
+ temp = remaining / animation.duration || 0,
+ percent = 1 - temp,
+ index = 0,
+ length = animation.tweens.length;
+
+ for ( ; index < length; index++ ) {
+ animation.tweens[ index ].run( percent );
+ }
+
+ deferred.notifyWith( elem, [ animation, percent, remaining ] );
+
+ // If there's more to do, yield
+ if ( percent < 1 && length ) {
+ return remaining;
+ }
+
+ // If this was an empty animation, synthesize a final progress notification
+ if ( !length ) {
+ deferred.notifyWith( elem, [ animation, 1, 0 ] );
+ }
+
+ // Resolve the animation and report its conclusion
+ deferred.resolveWith( elem, [ animation ] );
+ return false;
+ },
+ animation = deferred.promise( {
+ elem: elem,
+ props: jQuery.extend( {}, properties ),
+ opts: jQuery.extend( true, {
+ specialEasing: {},
+ easing: jQuery.easing._default
+ }, options ),
+ originalProperties: properties,
+ originalOptions: options,
+ startTime: fxNow || createFxNow(),
+ duration: options.duration,
+ tweens: [],
+ createTween: function( prop, end ) {
+ var tween = jQuery.Tween( elem, animation.opts, prop, end,
+ animation.opts.specialEasing[ prop ] || animation.opts.easing );
+ animation.tweens.push( tween );
+ return tween;
+ },
+ stop: function( gotoEnd ) {
+ var index = 0,
+
+ // If we are going to the end, we want to run all the tweens
+ // otherwise we skip this part
+ length = gotoEnd ? animation.tweens.length : 0;
+ if ( stopped ) {
+ return this;
+ }
+ stopped = true;
+ for ( ; index < length; index++ ) {
+ animation.tweens[ index ].run( 1 );
+ }
+
+ // Resolve when we played the last frame; otherwise, reject
+ if ( gotoEnd ) {
+ deferred.notifyWith( elem, [ animation, 1, 0 ] );
+ deferred.resolveWith( elem, [ animation, gotoEnd ] );
+ } else {
+ deferred.rejectWith( elem, [ animation, gotoEnd ] );
+ }
+ return this;
+ }
+ } ),
+ props = animation.props;
+
+ propFilter( props, animation.opts.specialEasing );
+
+ for ( ; index < length; index++ ) {
+ result = Animation.prefilters[ index ].call( animation, elem, props, animation.opts );
+ if ( result ) {
+ if ( jQuery.isFunction( result.stop ) ) {
+ jQuery._queueHooks( animation.elem, animation.opts.queue ).stop =
+ jQuery.proxy( result.stop, result );
+ }
+ return result;
+ }
+ }
+
+ jQuery.map( props, createTween, animation );
+
+ if ( jQuery.isFunction( animation.opts.start ) ) {
+ animation.opts.start.call( elem, animation );
+ }
+
+ // Attach callbacks from options
+ animation
+ .progress( animation.opts.progress )
+ .done( animation.opts.done, animation.opts.complete )
+ .fail( animation.opts.fail )
+ .always( animation.opts.always );
+
+ jQuery.fx.timer(
+ jQuery.extend( tick, {
+ elem: elem,
+ anim: animation,
+ queue: animation.opts.queue
+ } )
+ );
+
+ return animation;
+}
+
+jQuery.Animation = jQuery.extend( Animation, {
+
+ tweeners: {
+ "*": [ function( prop, value ) {
+ var tween = this.createTween( prop, value );
+ adjustCSS( tween.elem, prop, rcssNum.exec( value ), tween );
+ return tween;
+ } ]
+ },
+
+ tweener: function( props, callback ) {
+ if ( jQuery.isFunction( props ) ) {
+ callback = props;
+ props = [ "*" ];
+ } else {
+ props = props.match( rnothtmlwhite );
+ }
+
+ var prop,
+ index = 0,
+ length = props.length;
+
+ for ( ; index < length; index++ ) {
+ prop = props[ index ];
+ Animation.tweeners[ prop ] = Animation.tweeners[ prop ] || [];
+ Animation.tweeners[ prop ].unshift( callback );
+ }
+ },
+
+ prefilters: [ defaultPrefilter ],
+
+ prefilter: function( callback, prepend ) {
+ if ( prepend ) {
+ Animation.prefilters.unshift( callback );
+ } else {
+ Animation.prefilters.push( callback );
+ }
+ }
+} );
+
+jQuery.speed = function( speed, easing, fn ) {
+ var opt = speed && typeof speed === "object" ? jQuery.extend( {}, speed ) : {
+ complete: fn || !fn && easing ||
+ jQuery.isFunction( speed ) && speed,
+ duration: speed,
+ easing: fn && easing || easing && !jQuery.isFunction( easing ) && easing
+ };
+
+ // Go to the end state if fx are off
+ if ( jQuery.fx.off ) {
+ opt.duration = 0;
+
+ } else {
+ if ( typeof opt.duration !== "number" ) {
+ if ( opt.duration in jQuery.fx.speeds ) {
+ opt.duration = jQuery.fx.speeds[ opt.duration ];
+
+ } else {
+ opt.duration = jQuery.fx.speeds._default;
+ }
+ }
+ }
+
+ // Normalize opt.queue - true/undefined/null -> "fx"
+ if ( opt.queue == null || opt.queue === true ) {
+ opt.queue = "fx";
+ }
+
+ // Queueing
+ opt.old = opt.complete;
+
+ opt.complete = function() {
+ if ( jQuery.isFunction( opt.old ) ) {
+ opt.old.call( this );
+ }
+
+ if ( opt.queue ) {
+ jQuery.dequeue( this, opt.queue );
+ }
+ };
+
+ return opt;
+};
+
+jQuery.fn.extend( {
+ fadeTo: function( speed, to, easing, callback ) {
+
+ // Show any hidden elements after setting opacity to 0
+ return this.filter( isHiddenWithinTree ).css( "opacity", 0 ).show()
+
+ // Animate to the value specified
+ .end().animate( { opacity: to }, speed, easing, callback );
+ },
+ animate: function( prop, speed, easing, callback ) {
+ var empty = jQuery.isEmptyObject( prop ),
+ optall = jQuery.speed( speed, easing, callback ),
+ doAnimation = function() {
+
+ // Operate on a copy of prop so per-property easing won't be lost
+ var anim = Animation( this, jQuery.extend( {}, prop ), optall );
+
+ // Empty animations, or finishing resolves immediately
+ if ( empty || dataPriv.get( this, "finish" ) ) {
+ anim.stop( true );
+ }
+ };
+ doAnimation.finish = doAnimation;
+
+ return empty || optall.queue === false ?
+ this.each( doAnimation ) :
+ this.queue( optall.queue, doAnimation );
+ },
+ stop: function( type, clearQueue, gotoEnd ) {
+ var stopQueue = function( hooks ) {
+ var stop = hooks.stop;
+ delete hooks.stop;
+ stop( gotoEnd );
+ };
+
+ if ( typeof type !== "string" ) {
+ gotoEnd = clearQueue;
+ clearQueue = type;
+ type = undefined;
+ }
+ if ( clearQueue && type !== false ) {
+ this.queue( type || "fx", [] );
+ }
+
+ return this.each( function() {
+ var dequeue = true,
+ index = type != null && type + "queueHooks",
+ timers = jQuery.timers,
+ data = dataPriv.get( this );
+
+ if ( index ) {
+ if ( data[ index ] && data[ index ].stop ) {
+ stopQueue( data[ index ] );
+ }
+ } else {
+ for ( index in data ) {
+ if ( data[ index ] && data[ index ].stop && rrun.test( index ) ) {
+ stopQueue( data[ index ] );
+ }
+ }
+ }
+
+ for ( index = timers.length; index--; ) {
+ if ( timers[ index ].elem === this &&
+ ( type == null || timers[ index ].queue === type ) ) {
+
+ timers[ index ].anim.stop( gotoEnd );
+ dequeue = false;
+ timers.splice( index, 1 );
+ }
+ }
+
+ // Start the next in the queue if the last step wasn't forced.
+ // Timers currently will call their complete callbacks, which
+ // will dequeue but only if they were gotoEnd.
+ if ( dequeue || !gotoEnd ) {
+ jQuery.dequeue( this, type );
+ }
+ } );
+ },
+ finish: function( type ) {
+ if ( type !== false ) {
+ type = type || "fx";
+ }
+ return this.each( function() {
+ var index,
+ data = dataPriv.get( this ),
+ queue = data[ type + "queue" ],
+ hooks = data[ type + "queueHooks" ],
+ timers = jQuery.timers,
+ length = queue ? queue.length : 0;
+
+ // Enable finishing flag on private data
+ data.finish = true;
+
+ // Empty the queue first
+ jQuery.queue( this, type, [] );
+
+ if ( hooks && hooks.stop ) {
+ hooks.stop.call( this, true );
+ }
+
+ // Look for any active animations, and finish them
+ for ( index = timers.length; index--; ) {
+ if ( timers[ index ].elem === this && timers[ index ].queue === type ) {
+ timers[ index ].anim.stop( true );
+ timers.splice( index, 1 );
+ }
+ }
+
+ // Look for any animations in the old queue and finish them
+ for ( index = 0; index < length; index++ ) {
+ if ( queue[ index ] && queue[ index ].finish ) {
+ queue[ index ].finish.call( this );
+ }
+ }
+
+ // Turn off finishing flag
+ delete data.finish;
+ } );
+ }
+} );
+
+jQuery.each( [ "toggle", "show", "hide" ], function( i, name ) {
+ var cssFn = jQuery.fn[ name ];
+ jQuery.fn[ name ] = function( speed, easing, callback ) {
+ return speed == null || typeof speed === "boolean" ?
+ cssFn.apply( this, arguments ) :
+ this.animate( genFx( name, true ), speed, easing, callback );
+ };
+} );
+
+// Generate shortcuts for custom animations
+jQuery.each( {
+ slideDown: genFx( "show" ),
+ slideUp: genFx( "hide" ),
+ slideToggle: genFx( "toggle" ),
+ fadeIn: { opacity: "show" },
+ fadeOut: { opacity: "hide" },
+ fadeToggle: { opacity: "toggle" }
+}, function( name, props ) {
+ jQuery.fn[ name ] = function( speed, easing, callback ) {
+ return this.animate( props, speed, easing, callback );
+ };
+} );
+
+jQuery.timers = [];
+jQuery.fx.tick = function() {
+ var timer,
+ i = 0,
+ timers = jQuery.timers;
+
+ fxNow = jQuery.now();
+
+ for ( ; i < timers.length; i++ ) {
+ timer = timers[ i ];
+
+ // Run the timer and safely remove it when done (allowing for external removal)
+ if ( !timer() && timers[ i ] === timer ) {
+ timers.splice( i--, 1 );
+ }
+ }
+
+ if ( !timers.length ) {
+ jQuery.fx.stop();
+ }
+ fxNow = undefined;
+};
+
+jQuery.fx.timer = function( timer ) {
+ jQuery.timers.push( timer );
+ jQuery.fx.start();
+};
+
+jQuery.fx.interval = 13;
+jQuery.fx.start = function() {
+ if ( inProgress ) {
+ return;
+ }
+
+ inProgress = true;
+ schedule();
+};
+
+jQuery.fx.stop = function() {
+ inProgress = null;
+};
+
+jQuery.fx.speeds = {
+ slow: 600,
+ fast: 200,
+
+ // Default speed
+ _default: 400
+};
+
+
+// Based off of the plugin by Clint Helfers, with permission.
+// https://web.archive.org/web/20100324014747/http://blindsignals.com/index.php/2009/07/jquery-delay/
+jQuery.fn.delay = function( time, type ) {
+ time = jQuery.fx ? jQuery.fx.speeds[ time ] || time : time;
+ type = type || "fx";
+
+ return this.queue( type, function( next, hooks ) {
+ var timeout = window.setTimeout( next, time );
+ hooks.stop = function() {
+ window.clearTimeout( timeout );
+ };
+ } );
+};
+
+
+( function() {
+ var input = document.createElement( "input" ),
+ select = document.createElement( "select" ),
+ opt = select.appendChild( document.createElement( "option" ) );
+
+ input.type = "checkbox";
+
+ // Support: Android <=4.3 only
+ // Default value for a checkbox should be "on"
+ support.checkOn = input.value !== "";
+
+ // Support: IE <=11 only
+ // Must access selectedIndex to make default options select
+ support.optSelected = opt.selected;
+
+ // Support: IE <=11 only
+ // An input loses its value after becoming a radio
+ input = document.createElement( "input" );
+ input.value = "t";
+ input.type = "radio";
+ support.radioValue = input.value === "t";
+} )();
+
+
+var boolHook,
+ attrHandle = jQuery.expr.attrHandle;
+
+jQuery.fn.extend( {
+ attr: function( name, value ) {
+ return access( this, jQuery.attr, name, value, arguments.length > 1 );
+ },
+
+ removeAttr: function( name ) {
+ return this.each( function() {
+ jQuery.removeAttr( this, name );
+ } );
+ }
+} );
+
+jQuery.extend( {
+ attr: function( elem, name, value ) {
+ var ret, hooks,
+ nType = elem.nodeType;
+
+ // Don't get/set attributes on text, comment and attribute nodes
+ if ( nType === 3 || nType === 8 || nType === 2 ) {
+ return;
+ }
+
+ // Fallback to prop when attributes are not supported
+ if ( typeof elem.getAttribute === "undefined" ) {
+ return jQuery.prop( elem, name, value );
+ }
+
+ // Attribute hooks are determined by the lowercase version
+ // Grab necessary hook if one is defined
+ if ( nType !== 1 || !jQuery.isXMLDoc( elem ) ) {
+ hooks = jQuery.attrHooks[ name.toLowerCase() ] ||
+ ( jQuery.expr.match.bool.test( name ) ? boolHook : undefined );
+ }
+
+ if ( value !== undefined ) {
+ if ( value === null ) {
+ jQuery.removeAttr( elem, name );
+ return;
+ }
+
+ if ( hooks && "set" in hooks &&
+ ( ret = hooks.set( elem, value, name ) ) !== undefined ) {
+ return ret;
+ }
+
+ elem.setAttribute( name, value + "" );
+ return value;
+ }
+
+ if ( hooks && "get" in hooks && ( ret = hooks.get( elem, name ) ) !== null ) {
+ return ret;
+ }
+
+ ret = jQuery.find.attr( elem, name );
+
+ // Non-existent attributes return null, we normalize to undefined
+ return ret == null ? undefined : ret;
+ },
+
+ attrHooks: {
+ type: {
+ set: function( elem, value ) {
+ if ( !support.radioValue && value === "radio" &&
+ nodeName( elem, "input" ) ) {
+ var val = elem.value;
+ elem.setAttribute( "type", value );
+ if ( val ) {
+ elem.value = val;
+ }
+ return value;
+ }
+ }
+ }
+ },
+
+ removeAttr: function( elem, value ) {
+ var name,
+ i = 0,
+
+ // Attribute names can contain non-HTML whitespace characters
+ // https://html.spec.whatwg.org/multipage/syntax.html#attributes-2
+ attrNames = value && value.match( rnothtmlwhite );
+
+ if ( attrNames && elem.nodeType === 1 ) {
+ while ( ( name = attrNames[ i++ ] ) ) {
+ elem.removeAttribute( name );
+ }
+ }
+ }
+} );
+
+// Hooks for boolean attributes
+boolHook = {
+ set: function( elem, value, name ) {
+ if ( value === false ) {
+
+ // Remove boolean attributes when set to false
+ jQuery.removeAttr( elem, name );
+ } else {
+ elem.setAttribute( name, name );
+ }
+ return name;
+ }
+};
+
+jQuery.each( jQuery.expr.match.bool.source.match( /\w+/g ), function( i, name ) {
+ var getter = attrHandle[ name ] || jQuery.find.attr;
+
+ attrHandle[ name ] = function( elem, name, isXML ) {
+ var ret, handle,
+ lowercaseName = name.toLowerCase();
+
+ if ( !isXML ) {
+
+ // Avoid an infinite loop by temporarily removing this function from the getter
+ handle = attrHandle[ lowercaseName ];
+ attrHandle[ lowercaseName ] = ret;
+ ret = getter( elem, name, isXML ) != null ?
+ lowercaseName :
+ null;
+ attrHandle[ lowercaseName ] = handle;
+ }
+ return ret;
+ };
+} );
+
+
+
+
+var rfocusable = /^(?:input|select|textarea|button)$/i,
+ rclickable = /^(?:a|area)$/i;
+
+jQuery.fn.extend( {
+ prop: function( name, value ) {
+ return access( this, jQuery.prop, name, value, arguments.length > 1 );
+ },
+
+ removeProp: function( name ) {
+ return this.each( function() {
+ delete this[ jQuery.propFix[ name ] || name ];
+ } );
+ }
+} );
+
+jQuery.extend( {
+ prop: function( elem, name, value ) {
+ var ret, hooks,
+ nType = elem.nodeType;
+
+ // Don't get/set properties on text, comment and attribute nodes
+ if ( nType === 3 || nType === 8 || nType === 2 ) {
+ return;
+ }
+
+ if ( nType !== 1 || !jQuery.isXMLDoc( elem ) ) {
+
+ // Fix name and attach hooks
+ name = jQuery.propFix[ name ] || name;
+ hooks = jQuery.propHooks[ name ];
+ }
+
+ if ( value !== undefined ) {
+ if ( hooks && "set" in hooks &&
+ ( ret = hooks.set( elem, value, name ) ) !== undefined ) {
+ return ret;
+ }
+
+ return ( elem[ name ] = value );
+ }
+
+ if ( hooks && "get" in hooks && ( ret = hooks.get( elem, name ) ) !== null ) {
+ return ret;
+ }
+
+ return elem[ name ];
+ },
+
+ propHooks: {
+ tabIndex: {
+ get: function( elem ) {
+
+ // Support: IE <=9 - 11 only
+ // elem.tabIndex doesn't always return the
+ // correct value when it hasn't been explicitly set
+ // https://web.archive.org/web/20141116233347/http://fluidproject.org/blog/2008/01/09/getting-setting-and-removing-tabindex-values-with-javascript/
+ // Use proper attribute retrieval(#12072)
+ var tabindex = jQuery.find.attr( elem, "tabindex" );
+
+ if ( tabindex ) {
+ return parseInt( tabindex, 10 );
+ }
+
+ if (
+ rfocusable.test( elem.nodeName ) ||
+ rclickable.test( elem.nodeName ) &&
+ elem.href
+ ) {
+ return 0;
+ }
+
+ return -1;
+ }
+ }
+ },
+
+ propFix: {
+ "for": "htmlFor",
+ "class": "className"
+ }
+} );
+
+// Support: IE <=11 only
+// Accessing the selectedIndex property
+// forces the browser to respect setting selected
+// on the option
+// The getter ensures a default option is selected
+// when in an optgroup
+// eslint rule "no-unused-expressions" is disabled for this code
+// since it considers such accessions noop
+if ( !support.optSelected ) {
+ jQuery.propHooks.selected = {
+ get: function( elem ) {
+
+ /* eslint no-unused-expressions: "off" */
+
+ var parent = elem.parentNode;
+ if ( parent && parent.parentNode ) {
+ parent.parentNode.selectedIndex;
+ }
+ return null;
+ },
+ set: function( elem ) {
+
+ /* eslint no-unused-expressions: "off" */
+
+ var parent = elem.parentNode;
+ if ( parent ) {
+ parent.selectedIndex;
+
+ if ( parent.parentNode ) {
+ parent.parentNode.selectedIndex;
+ }
+ }
+ }
+ };
+}
+
+jQuery.each( [
+ "tabIndex",
+ "readOnly",
+ "maxLength",
+ "cellSpacing",
+ "cellPadding",
+ "rowSpan",
+ "colSpan",
+ "useMap",
+ "frameBorder",
+ "contentEditable"
+], function() {
+ jQuery.propFix[ this.toLowerCase() ] = this;
+} );
+
+
+
+
+ // Strip and collapse whitespace according to HTML spec
+ // https://html.spec.whatwg.org/multipage/infrastructure.html#strip-and-collapse-whitespace
+ function stripAndCollapse( value ) {
+ var tokens = value.match( rnothtmlwhite ) || [];
+ return tokens.join( " " );
+ }
+
+
+function getClass( elem ) {
+ return elem.getAttribute && elem.getAttribute( "class" ) || "";
+}
+
+jQuery.fn.extend( {
+ addClass: function( value ) {
+ var classes, elem, cur, curValue, clazz, j, finalValue,
+ i = 0;
+
+ if ( jQuery.isFunction( value ) ) {
+ return this.each( function( j ) {
+ jQuery( this ).addClass( value.call( this, j, getClass( this ) ) );
+ } );
+ }
+
+ if ( typeof value === "string" && value ) {
+ classes = value.match( rnothtmlwhite ) || [];
+
+ while ( ( elem = this[ i++ ] ) ) {
+ curValue = getClass( elem );
+ cur = elem.nodeType === 1 && ( " " + stripAndCollapse( curValue ) + " " );
+
+ if ( cur ) {
+ j = 0;
+ while ( ( clazz = classes[ j++ ] ) ) {
+ if ( cur.indexOf( " " + clazz + " " ) < 0 ) {
+ cur += clazz + " ";
+ }
+ }
+
+ // Only assign if different to avoid unneeded rendering.
+ finalValue = stripAndCollapse( cur );
+ if ( curValue !== finalValue ) {
+ elem.setAttribute( "class", finalValue );
+ }
+ }
+ }
+ }
+
+ return this;
+ },
+
+ removeClass: function( value ) {
+ var classes, elem, cur, curValue, clazz, j, finalValue,
+ i = 0;
+
+ if ( jQuery.isFunction( value ) ) {
+ return this.each( function( j ) {
+ jQuery( this ).removeClass( value.call( this, j, getClass( this ) ) );
+ } );
+ }
+
+ if ( !arguments.length ) {
+ return this.attr( "class", "" );
+ }
+
+ if ( typeof value === "string" && value ) {
+ classes = value.match( rnothtmlwhite ) || [];
+
+ while ( ( elem = this[ i++ ] ) ) {
+ curValue = getClass( elem );
+
+ // This expression is here for better compressibility (see addClass)
+ cur = elem.nodeType === 1 && ( " " + stripAndCollapse( curValue ) + " " );
+
+ if ( cur ) {
+ j = 0;
+ while ( ( clazz = classes[ j++ ] ) ) {
+
+ // Remove *all* instances
+ while ( cur.indexOf( " " + clazz + " " ) > -1 ) {
+ cur = cur.replace( " " + clazz + " ", " " );
+ }
+ }
+
+ // Only assign if different to avoid unneeded rendering.
+ finalValue = stripAndCollapse( cur );
+ if ( curValue !== finalValue ) {
+ elem.setAttribute( "class", finalValue );
+ }
+ }
+ }
+ }
+
+ return this;
+ },
+
+ toggleClass: function( value, stateVal ) {
+ var type = typeof value;
+
+ if ( typeof stateVal === "boolean" && type === "string" ) {
+ return stateVal ? this.addClass( value ) : this.removeClass( value );
+ }
+
+ if ( jQuery.isFunction( value ) ) {
+ return this.each( function( i ) {
+ jQuery( this ).toggleClass(
+ value.call( this, i, getClass( this ), stateVal ),
+ stateVal
+ );
+ } );
+ }
+
+ return this.each( function() {
+ var className, i, self, classNames;
+
+ if ( type === "string" ) {
+
+ // Toggle individual class names
+ i = 0;
+ self = jQuery( this );
+ classNames = value.match( rnothtmlwhite ) || [];
+
+ while ( ( className = classNames[ i++ ] ) ) {
+
+ // Check each className given, space separated list
+ if ( self.hasClass( className ) ) {
+ self.removeClass( className );
+ } else {
+ self.addClass( className );
+ }
+ }
+
+ // Toggle whole class name
+ } else if ( value === undefined || type === "boolean" ) {
+ className = getClass( this );
+ if ( className ) {
+
+ // Store className if set
+ dataPriv.set( this, "__className__", className );
+ }
+
+ // If the element has a class name or if we're passed `false`,
+ // then remove the whole classname (if there was one, the above saved it).
+ // Otherwise bring back whatever was previously saved (if anything),
+ // falling back to the empty string if nothing was stored.
+ if ( this.setAttribute ) {
+ this.setAttribute( "class",
+ className || value === false ?
+ "" :
+ dataPriv.get( this, "__className__" ) || ""
+ );
+ }
+ }
+ } );
+ },
+
+ hasClass: function( selector ) {
+ var className, elem,
+ i = 0;
+
+ className = " " + selector + " ";
+ while ( ( elem = this[ i++ ] ) ) {
+ if ( elem.nodeType === 1 &&
+ ( " " + stripAndCollapse( getClass( elem ) ) + " " ).indexOf( className ) > -1 ) {
+ return true;
+ }
+ }
+
+ return false;
+ }
+} );
+
+
+
+
+var rreturn = /\r/g;
+
+jQuery.fn.extend( {
+ val: function( value ) {
+ var hooks, ret, isFunction,
+ elem = this[ 0 ];
+
+ if ( !arguments.length ) {
+ if ( elem ) {
+ hooks = jQuery.valHooks[ elem.type ] ||
+ jQuery.valHooks[ elem.nodeName.toLowerCase() ];
+
+ if ( hooks &&
+ "get" in hooks &&
+ ( ret = hooks.get( elem, "value" ) ) !== undefined
+ ) {
+ return ret;
+ }
+
+ ret = elem.value;
+
+ // Handle most common string cases
+ if ( typeof ret === "string" ) {
+ return ret.replace( rreturn, "" );
+ }
+
+ // Handle cases where value is null/undef or number
+ return ret == null ? "" : ret;
+ }
+
+ return;
+ }
+
+ isFunction = jQuery.isFunction( value );
+
+ return this.each( function( i ) {
+ var val;
+
+ if ( this.nodeType !== 1 ) {
+ return;
+ }
+
+ if ( isFunction ) {
+ val = value.call( this, i, jQuery( this ).val() );
+ } else {
+ val = value;
+ }
+
+ // Treat null/undefined as ""; convert numbers to string
+ if ( val == null ) {
+ val = "";
+
+ } else if ( typeof val === "number" ) {
+ val += "";
+
+ } else if ( Array.isArray( val ) ) {
+ val = jQuery.map( val, function( value ) {
+ return value == null ? "" : value + "";
+ } );
+ }
+
+ hooks = jQuery.valHooks[ this.type ] || jQuery.valHooks[ this.nodeName.toLowerCase() ];
+
+ // If set returns undefined, fall back to normal setting
+ if ( !hooks || !( "set" in hooks ) || hooks.set( this, val, "value" ) === undefined ) {
+ this.value = val;
+ }
+ } );
+ }
+} );
+
+jQuery.extend( {
+ valHooks: {
+ option: {
+ get: function( elem ) {
+
+ var val = jQuery.find.attr( elem, "value" );
+ return val != null ?
+ val :
+
+ // Support: IE <=10 - 11 only
+ // option.text throws exceptions (#14686, #14858)
+ // Strip and collapse whitespace
+ // https://html.spec.whatwg.org/#strip-and-collapse-whitespace
+ stripAndCollapse( jQuery.text( elem ) );
+ }
+ },
+ select: {
+ get: function( elem ) {
+ var value, option, i,
+ options = elem.options,
+ index = elem.selectedIndex,
+ one = elem.type === "select-one",
+ values = one ? null : [],
+ max = one ? index + 1 : options.length;
+
+ if ( index < 0 ) {
+ i = max;
+
+ } else {
+ i = one ? index : 0;
+ }
+
+ // Loop through all the selected options
+ for ( ; i < max; i++ ) {
+ option = options[ i ];
+
+ // Support: IE <=9 only
+ // IE8-9 doesn't update selected after form reset (#2551)
+ if ( ( option.selected || i === index ) &&
+
+ // Don't return options that are disabled or in a disabled optgroup
+ !option.disabled &&
+ ( !option.parentNode.disabled ||
+ !nodeName( option.parentNode, "optgroup" ) ) ) {
+
+ // Get the specific value for the option
+ value = jQuery( option ).val();
+
+ // We don't need an array for one selects
+ if ( one ) {
+ return value;
+ }
+
+ // Multi-Selects return an array
+ values.push( value );
+ }
+ }
+
+ return values;
+ },
+
+ set: function( elem, value ) {
+ var optionSet, option,
+ options = elem.options,
+ values = jQuery.makeArray( value ),
+ i = options.length;
+
+ while ( i-- ) {
+ option = options[ i ];
+
+ /* eslint-disable no-cond-assign */
+
+ if ( option.selected =
+ jQuery.inArray( jQuery.valHooks.option.get( option ), values ) > -1
+ ) {
+ optionSet = true;
+ }
+
+ /* eslint-enable no-cond-assign */
+ }
+
+ // Force browsers to behave consistently when non-matching value is set
+ if ( !optionSet ) {
+ elem.selectedIndex = -1;
+ }
+ return values;
+ }
+ }
+ }
+} );
+
+// Radios and checkboxes getter/setter
+jQuery.each( [ "radio", "checkbox" ], function() {
+ jQuery.valHooks[ this ] = {
+ set: function( elem, value ) {
+ if ( Array.isArray( value ) ) {
+ return ( elem.checked = jQuery.inArray( jQuery( elem ).val(), value ) > -1 );
+ }
+ }
+ };
+ if ( !support.checkOn ) {
+ jQuery.valHooks[ this ].get = function( elem ) {
+ return elem.getAttribute( "value" ) === null ? "on" : elem.value;
+ };
+ }
+} );
+
+
+
+
+// Return jQuery for attributes-only inclusion
+
+
+var rfocusMorph = /^(?:focusinfocus|focusoutblur)$/;
+
+jQuery.extend( jQuery.event, {
+
+ trigger: function( event, data, elem, onlyHandlers ) {
+
+ var i, cur, tmp, bubbleType, ontype, handle, special,
+ eventPath = [ elem || document ],
+ type = hasOwn.call( event, "type" ) ? event.type : event,
+ namespaces = hasOwn.call( event, "namespace" ) ? event.namespace.split( "." ) : [];
+
+ cur = tmp = elem = elem || document;
+
+ // Don't do events on text and comment nodes
+ if ( elem.nodeType === 3 || elem.nodeType === 8 ) {
+ return;
+ }
+
+ // focus/blur morphs to focusin/out; ensure we're not firing them right now
+ if ( rfocusMorph.test( type + jQuery.event.triggered ) ) {
+ return;
+ }
+
+ if ( type.indexOf( "." ) > -1 ) {
+
+ // Namespaced trigger; create a regexp to match event type in handle()
+ namespaces = type.split( "." );
+ type = namespaces.shift();
+ namespaces.sort();
+ }
+ ontype = type.indexOf( ":" ) < 0 && "on" + type;
+
+ // Caller can pass in a jQuery.Event object, Object, or just an event type string
+ event = event[ jQuery.expando ] ?
+ event :
+ new jQuery.Event( type, typeof event === "object" && event );
+
+ // Trigger bitmask: & 1 for native handlers; & 2 for jQuery (always true)
+ event.isTrigger = onlyHandlers ? 2 : 3;
+ event.namespace = namespaces.join( "." );
+ event.rnamespace = event.namespace ?
+ new RegExp( "(^|\\.)" + namespaces.join( "\\.(?:.*\\.|)" ) + "(\\.|$)" ) :
+ null;
+
+ // Clean up the event in case it is being reused
+ event.result = undefined;
+ if ( !event.target ) {
+ event.target = elem;
+ }
+
+ // Clone any incoming data and prepend the event, creating the handler arg list
+ data = data == null ?
+ [ event ] :
+ jQuery.makeArray( data, [ event ] );
+
+ // Allow special events to draw outside the lines
+ special = jQuery.event.special[ type ] || {};
+ if ( !onlyHandlers && special.trigger && special.trigger.apply( elem, data ) === false ) {
+ return;
+ }
+
+ // Determine event propagation path in advance, per W3C events spec (#9951)
+ // Bubble up to document, then to window; watch for a global ownerDocument var (#9724)
+ if ( !onlyHandlers && !special.noBubble && !jQuery.isWindow( elem ) ) {
+
+ bubbleType = special.delegateType || type;
+ if ( !rfocusMorph.test( bubbleType + type ) ) {
+ cur = cur.parentNode;
+ }
+ for ( ; cur; cur = cur.parentNode ) {
+ eventPath.push( cur );
+ tmp = cur;
+ }
+
+ // Only add window if we got to document (e.g., not plain obj or detached DOM)
+ if ( tmp === ( elem.ownerDocument || document ) ) {
+ eventPath.push( tmp.defaultView || tmp.parentWindow || window );
+ }
+ }
+
+ // Fire handlers on the event path
+ i = 0;
+ while ( ( cur = eventPath[ i++ ] ) && !event.isPropagationStopped() ) {
+
+ event.type = i > 1 ?
+ bubbleType :
+ special.bindType || type;
+
+ // jQuery handler
+ handle = ( dataPriv.get( cur, "events" ) || {} )[ event.type ] &&
+ dataPriv.get( cur, "handle" );
+ if ( handle ) {
+ handle.apply( cur, data );
+ }
+
+ // Native handler
+ handle = ontype && cur[ ontype ];
+ if ( handle && handle.apply && acceptData( cur ) ) {
+ event.result = handle.apply( cur, data );
+ if ( event.result === false ) {
+ event.preventDefault();
+ }
+ }
+ }
+ event.type = type;
+
+ // If nobody prevented the default action, do it now
+ if ( !onlyHandlers && !event.isDefaultPrevented() ) {
+
+ if ( ( !special._default ||
+ special._default.apply( eventPath.pop(), data ) === false ) &&
+ acceptData( elem ) ) {
+
+ // Call a native DOM method on the target with the same name as the event.
+ // Don't do default actions on window, that's where global variables be (#6170)
+ if ( ontype && jQuery.isFunction( elem[ type ] ) && !jQuery.isWindow( elem ) ) {
+
+ // Don't re-trigger an onFOO event when we call its FOO() method
+ tmp = elem[ ontype ];
+
+ if ( tmp ) {
+ elem[ ontype ] = null;
+ }
+
+ // Prevent re-triggering of the same event, since we already bubbled it above
+ jQuery.event.triggered = type;
+ elem[ type ]();
+ jQuery.event.triggered = undefined;
+
+ if ( tmp ) {
+ elem[ ontype ] = tmp;
+ }
+ }
+ }
+ }
+
+ return event.result;
+ },
+
+ // Piggyback on a donor event to simulate a different one
+ // Used only for `focus(in | out)` events
+ simulate: function( type, elem, event ) {
+ var e = jQuery.extend(
+ new jQuery.Event(),
+ event,
+ {
+ type: type,
+ isSimulated: true
+ }
+ );
+
+ jQuery.event.trigger( e, null, elem );
+ }
+
+} );
+
+jQuery.fn.extend( {
+
+ trigger: function( type, data ) {
+ return this.each( function() {
+ jQuery.event.trigger( type, data, this );
+ } );
+ },
+ triggerHandler: function( type, data ) {
+ var elem = this[ 0 ];
+ if ( elem ) {
+ return jQuery.event.trigger( type, data, elem, true );
+ }
+ }
+} );
+
+
+jQuery.each( ( "blur focus focusin focusout resize scroll click dblclick " +
+ "mousedown mouseup mousemove mouseover mouseout mouseenter mouseleave " +
+ "change select submit keydown keypress keyup contextmenu" ).split( " " ),
+ function( i, name ) {
+
+ // Handle event binding
+ jQuery.fn[ name ] = function( data, fn ) {
+ return arguments.length > 0 ?
+ this.on( name, null, data, fn ) :
+ this.trigger( name );
+ };
+} );
+
+jQuery.fn.extend( {
+ hover: function( fnOver, fnOut ) {
+ return this.mouseenter( fnOver ).mouseleave( fnOut || fnOver );
+ }
+} );
+
+
+
+
+support.focusin = "onfocusin" in window;
+
+
+// Support: Firefox <=44
+// Firefox doesn't have focus(in | out) events
+// Related ticket - https://bugzilla.mozilla.org/show_bug.cgi?id=687787
+//
+// Support: Chrome <=48 - 49, Safari <=9.0 - 9.1
+// focus(in | out) events fire after focus & blur events,
+// which is spec violation - http://www.w3.org/TR/DOM-Level-3-Events/#events-focusevent-event-order
+// Related ticket - https://bugs.chromium.org/p/chromium/issues/detail?id=449857
+if ( !support.focusin ) {
+ jQuery.each( { focus: "focusin", blur: "focusout" }, function( orig, fix ) {
+
+ // Attach a single capturing handler on the document while someone wants focusin/focusout
+ var handler = function( event ) {
+ jQuery.event.simulate( fix, event.target, jQuery.event.fix( event ) );
+ };
+
+ jQuery.event.special[ fix ] = {
+ setup: function() {
+ var doc = this.ownerDocument || this,
+ attaches = dataPriv.access( doc, fix );
+
+ if ( !attaches ) {
+ doc.addEventListener( orig, handler, true );
+ }
+ dataPriv.access( doc, fix, ( attaches || 0 ) + 1 );
+ },
+ teardown: function() {
+ var doc = this.ownerDocument || this,
+ attaches = dataPriv.access( doc, fix ) - 1;
+
+ if ( !attaches ) {
+ doc.removeEventListener( orig, handler, true );
+ dataPriv.remove( doc, fix );
+
+ } else {
+ dataPriv.access( doc, fix, attaches );
+ }
+ }
+ };
+ } );
+}
+var location = window.location;
+
+var nonce = jQuery.now();
+
+var rquery = ( /\?/ );
+
+
+
+// Cross-browser xml parsing
+jQuery.parseXML = function( data ) {
+ var xml;
+ if ( !data || typeof data !== "string" ) {
+ return null;
+ }
+
+ // Support: IE 9 - 11 only
+ // IE throws on parseFromString with invalid input.
+ try {
+ xml = ( new window.DOMParser() ).parseFromString( data, "text/xml" );
+ } catch ( e ) {
+ xml = undefined;
+ }
+
+ if ( !xml || xml.getElementsByTagName( "parsererror" ).length ) {
+ jQuery.error( "Invalid XML: " + data );
+ }
+ return xml;
+};
+
+
+var
+ rbracket = /\[\]$/,
+ rCRLF = /\r?\n/g,
+ rsubmitterTypes = /^(?:submit|button|image|reset|file)$/i,
+ rsubmittable = /^(?:input|select|textarea|keygen)/i;
+
+function buildParams( prefix, obj, traditional, add ) {
+ var name;
+
+ if ( Array.isArray( obj ) ) {
+
+ // Serialize array item.
+ jQuery.each( obj, function( i, v ) {
+ if ( traditional || rbracket.test( prefix ) ) {
+
+ // Treat each array item as a scalar.
+ add( prefix, v );
+
+ } else {
+
+ // Item is non-scalar (array or object), encode its numeric index.
+ buildParams(
+ prefix + "[" + ( typeof v === "object" && v != null ? i : "" ) + "]",
+ v,
+ traditional,
+ add
+ );
+ }
+ } );
+
+ } else if ( !traditional && jQuery.type( obj ) === "object" ) {
+
+ // Serialize object item.
+ for ( name in obj ) {
+ buildParams( prefix + "[" + name + "]", obj[ name ], traditional, add );
+ }
+
+ } else {
+
+ // Serialize scalar item.
+ add( prefix, obj );
+ }
+}
+
+// Serialize an array of form elements or a set of
+// key/values into a query string
+jQuery.param = function( a, traditional ) {
+ var prefix,
+ s = [],
+ add = function( key, valueOrFunction ) {
+
+ // If value is a function, invoke it and use its return value
+ var value = jQuery.isFunction( valueOrFunction ) ?
+ valueOrFunction() :
+ valueOrFunction;
+
+ s[ s.length ] = encodeURIComponent( key ) + "=" +
+ encodeURIComponent( value == null ? "" : value );
+ };
+
+ // If an array was passed in, assume that it is an array of form elements.
+ if ( Array.isArray( a ) || ( a.jquery && !jQuery.isPlainObject( a ) ) ) {
+
+ // Serialize the form elements
+ jQuery.each( a, function() {
+ add( this.name, this.value );
+ } );
+
+ } else {
+
+ // If traditional, encode the "old" way (the way 1.3.2 or older
+ // did it), otherwise encode params recursively.
+ for ( prefix in a ) {
+ buildParams( prefix, a[ prefix ], traditional, add );
+ }
+ }
+
+ // Return the resulting serialization
+ return s.join( "&" );
+};
+
+jQuery.fn.extend( {
+ serialize: function() {
+ return jQuery.param( this.serializeArray() );
+ },
+ serializeArray: function() {
+ return this.map( function() {
+
+ // Can add propHook for "elements" to filter or add form elements
+ var elements = jQuery.prop( this, "elements" );
+ return elements ? jQuery.makeArray( elements ) : this;
+ } )
+ .filter( function() {
+ var type = this.type;
+
+ // Use .is( ":disabled" ) so that fieldset[disabled] works
+ return this.name && !jQuery( this ).is( ":disabled" ) &&
+ rsubmittable.test( this.nodeName ) && !rsubmitterTypes.test( type ) &&
+ ( this.checked || !rcheckableType.test( type ) );
+ } )
+ .map( function( i, elem ) {
+ var val = jQuery( this ).val();
+
+ if ( val == null ) {
+ return null;
+ }
+
+ if ( Array.isArray( val ) ) {
+ return jQuery.map( val, function( val ) {
+ return { name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
+ } );
+ }
+
+ return { name: elem.name, value: val.replace( rCRLF, "\r\n" ) };
+ } ).get();
+ }
+} );
+
+
+var
+ r20 = /%20/g,
+ rhash = /#.*$/,
+ rantiCache = /([?&])_=[^&]*/,
+ rheaders = /^(.*?):[ \t]*([^\r\n]*)$/mg,
+
+ // #7653, #8125, #8152: local protocol detection
+ rlocalProtocol = /^(?:about|app|app-storage|.+-extension|file|res|widget):$/,
+ rnoContent = /^(?:GET|HEAD)$/,
+ rprotocol = /^\/\//,
+
+ /* Prefilters
+ * 1) They are useful to introduce custom dataTypes (see ajax/jsonp.js for an example)
+ * 2) These are called:
+ * - BEFORE asking for a transport
+ * - AFTER param serialization (s.data is a string if s.processData is true)
+ * 3) key is the dataType
+ * 4) the catchall symbol "*" can be used
+ * 5) execution will start with transport dataType and THEN continue down to "*" if needed
+ */
+ prefilters = {},
+
+ /* Transports bindings
+ * 1) key is the dataType
+ * 2) the catchall symbol "*" can be used
+ * 3) selection will start with transport dataType and THEN go to "*" if needed
+ */
+ transports = {},
+
+ // Avoid comment-prolog char sequence (#10098); must appease lint and evade compression
+ allTypes = "*/".concat( "*" ),
+
+ // Anchor tag for parsing the document origin
+ originAnchor = document.createElement( "a" );
+ originAnchor.href = location.href;
+
+// Base "constructor" for jQuery.ajaxPrefilter and jQuery.ajaxTransport
+function addToPrefiltersOrTransports( structure ) {
+
+ // dataTypeExpression is optional and defaults to "*"
+ return function( dataTypeExpression, func ) {
+
+ if ( typeof dataTypeExpression !== "string" ) {
+ func = dataTypeExpression;
+ dataTypeExpression = "*";
+ }
+
+ var dataType,
+ i = 0,
+ dataTypes = dataTypeExpression.toLowerCase().match( rnothtmlwhite ) || [];
+
+ if ( jQuery.isFunction( func ) ) {
+
+ // For each dataType in the dataTypeExpression
+ while ( ( dataType = dataTypes[ i++ ] ) ) {
+
+ // Prepend if requested
+ if ( dataType[ 0 ] === "+" ) {
+ dataType = dataType.slice( 1 ) || "*";
+ ( structure[ dataType ] = structure[ dataType ] || [] ).unshift( func );
+
+ // Otherwise append
+ } else {
+ ( structure[ dataType ] = structure[ dataType ] || [] ).push( func );
+ }
+ }
+ }
+ };
+}
+
+// Base inspection function for prefilters and transports
+function inspectPrefiltersOrTransports( structure, options, originalOptions, jqXHR ) {
+
+ var inspected = {},
+ seekingTransport = ( structure === transports );
+
+ function inspect( dataType ) {
+ var selected;
+ inspected[ dataType ] = true;
+ jQuery.each( structure[ dataType ] || [], function( _, prefilterOrFactory ) {
+ var dataTypeOrTransport = prefilterOrFactory( options, originalOptions, jqXHR );
+ if ( typeof dataTypeOrTransport === "string" &&
+ !seekingTransport && !inspected[ dataTypeOrTransport ] ) {
+
+ options.dataTypes.unshift( dataTypeOrTransport );
+ inspect( dataTypeOrTransport );
+ return false;
+ } else if ( seekingTransport ) {
+ return !( selected = dataTypeOrTransport );
+ }
+ } );
+ return selected;
+ }
+
+ return inspect( options.dataTypes[ 0 ] ) || !inspected[ "*" ] && inspect( "*" );
+}
+
+// A special extend for ajax options
+// that takes "flat" options (not to be deep extended)
+// Fixes #9887
+function ajaxExtend( target, src ) {
+ var key, deep,
+ flatOptions = jQuery.ajaxSettings.flatOptions || {};
+
+ for ( key in src ) {
+ if ( src[ key ] !== undefined ) {
+ ( flatOptions[ key ] ? target : ( deep || ( deep = {} ) ) )[ key ] = src[ key ];
+ }
+ }
+ if ( deep ) {
+ jQuery.extend( true, target, deep );
+ }
+
+ return target;
+}
+
+/* Handles responses to an ajax request:
+ * - finds the right dataType (mediates between content-type and expected dataType)
+ * - returns the corresponding response
+ */
+function ajaxHandleResponses( s, jqXHR, responses ) {
+
+ var ct, type, finalDataType, firstDataType,
+ contents = s.contents,
+ dataTypes = s.dataTypes;
+
+ // Remove auto dataType and get content-type in the process
+ while ( dataTypes[ 0 ] === "*" ) {
+ dataTypes.shift();
+ if ( ct === undefined ) {
+ ct = s.mimeType || jqXHR.getResponseHeader( "Content-Type" );
+ }
+ }
+
+ // Check if we're dealing with a known content-type
+ if ( ct ) {
+ for ( type in contents ) {
+ if ( contents[ type ] && contents[ type ].test( ct ) ) {
+ dataTypes.unshift( type );
+ break;
+ }
+ }
+ }
+
+ // Check to see if we have a response for the expected dataType
+ if ( dataTypes[ 0 ] in responses ) {
+ finalDataType = dataTypes[ 0 ];
+ } else {
+
+ // Try convertible dataTypes
+ for ( type in responses ) {
+ if ( !dataTypes[ 0 ] || s.converters[ type + " " + dataTypes[ 0 ] ] ) {
+ finalDataType = type;
+ break;
+ }
+ if ( !firstDataType ) {
+ firstDataType = type;
+ }
+ }
+
+ // Or just use first one
+ finalDataType = finalDataType || firstDataType;
+ }
+
+ // If we found a dataType
+ // We add the dataType to the list if needed
+ // and return the corresponding response
+ if ( finalDataType ) {
+ if ( finalDataType !== dataTypes[ 0 ] ) {
+ dataTypes.unshift( finalDataType );
+ }
+ return responses[ finalDataType ];
+ }
+}
+
+/* Chain conversions given the request and the original response
+ * Also sets the responseXXX fields on the jqXHR instance
+ */
+function ajaxConvert( s, response, jqXHR, isSuccess ) {
+ var conv2, current, conv, tmp, prev,
+ converters = {},
+
+ // Work with a copy of dataTypes in case we need to modify it for conversion
+ dataTypes = s.dataTypes.slice();
+
+ // Create converters map with lowercased keys
+ if ( dataTypes[ 1 ] ) {
+ for ( conv in s.converters ) {
+ converters[ conv.toLowerCase() ] = s.converters[ conv ];
+ }
+ }
+
+ current = dataTypes.shift();
+
+ // Convert to each sequential dataType
+ while ( current ) {
+
+ if ( s.responseFields[ current ] ) {
+ jqXHR[ s.responseFields[ current ] ] = response;
+ }
+
+ // Apply the dataFilter if provided
+ if ( !prev && isSuccess && s.dataFilter ) {
+ response = s.dataFilter( response, s.dataType );
+ }
+
+ prev = current;
+ current = dataTypes.shift();
+
+ if ( current ) {
+
+ // There's only work to do if current dataType is non-auto
+ if ( current === "*" ) {
+
+ current = prev;
+
+ // Convert response if prev dataType is non-auto and differs from current
+ } else if ( prev !== "*" && prev !== current ) {
+
+ // Seek a direct converter
+ conv = converters[ prev + " " + current ] || converters[ "* " + current ];
+
+ // If none found, seek a pair
+ if ( !conv ) {
+ for ( conv2 in converters ) {
+
+ // If conv2 outputs current
+ tmp = conv2.split( " " );
+ if ( tmp[ 1 ] === current ) {
+
+ // If prev can be converted to accepted input
+ conv = converters[ prev + " " + tmp[ 0 ] ] ||
+ converters[ "* " + tmp[ 0 ] ];
+ if ( conv ) {
+
+ // Condense equivalence converters
+ if ( conv === true ) {
+ conv = converters[ conv2 ];
+
+ // Otherwise, insert the intermediate dataType
+ } else if ( converters[ conv2 ] !== true ) {
+ current = tmp[ 0 ];
+ dataTypes.unshift( tmp[ 1 ] );
+ }
+ break;
+ }
+ }
+ }
+ }
+
+ // Apply converter (if not an equivalence)
+ if ( conv !== true ) {
+
+ // Unless errors are allowed to bubble, catch and return them
+ if ( conv && s.throws ) {
+ response = conv( response );
+ } else {
+ try {
+ response = conv( response );
+ } catch ( e ) {
+ return {
+ state: "parsererror",
+ error: conv ? e : "No conversion from " + prev + " to " + current
+ };
+ }
+ }
+ }
+ }
+ }
+ }
+
+ return { state: "success", data: response };
+}
+
+jQuery.extend( {
+
+ // Counter for holding the number of active queries
+ active: 0,
+
+ // Last-Modified header cache for next request
+ lastModified: {},
+ etag: {},
+
+ ajaxSettings: {
+ url: location.href,
+ type: "GET",
+ isLocal: rlocalProtocol.test( location.protocol ),
+ global: true,
+ processData: true,
+ async: true,
+ contentType: "application/x-www-form-urlencoded; charset=UTF-8",
+
+ /*
+ timeout: 0,
+ data: null,
+ dataType: null,
+ username: null,
+ password: null,
+ cache: null,
+ throws: false,
+ traditional: false,
+ headers: {},
+ */
+
+ accepts: {
+ "*": allTypes,
+ text: "text/plain",
+ html: "text/html",
+ xml: "application/xml, text/xml",
+ json: "application/json, text/javascript"
+ },
+
+ contents: {
+ xml: /\bxml\b/,
+ html: /\bhtml/,
+ json: /\bjson\b/
+ },
+
+ responseFields: {
+ xml: "responseXML",
+ text: "responseText",
+ json: "responseJSON"
+ },
+
+ // Data converters
+ // Keys separate source (or catchall "*") and destination types with a single space
+ converters: {
+
+ // Convert anything to text
+ "* text": String,
+
+ // Text to html (true = no transformation)
+ "text html": true,
+
+ // Evaluate text as a json expression
+ "text json": JSON.parse,
+
+ // Parse text as xml
+ "text xml": jQuery.parseXML
+ },
+
+ // For options that shouldn't be deep extended:
+ // you can add your own custom options here if
+ // and when you create one that shouldn't be
+ // deep extended (see ajaxExtend)
+ flatOptions: {
+ url: true,
+ context: true
+ }
+ },
+
+ // Creates a full fledged settings object into target
+ // with both ajaxSettings and settings fields.
+ // If target is omitted, writes into ajaxSettings.
+ ajaxSetup: function( target, settings ) {
+ return settings ?
+
+ // Building a settings object
+ ajaxExtend( ajaxExtend( target, jQuery.ajaxSettings ), settings ) :
+
+ // Extending ajaxSettings
+ ajaxExtend( jQuery.ajaxSettings, target );
+ },
+
+ ajaxPrefilter: addToPrefiltersOrTransports( prefilters ),
+ ajaxTransport: addToPrefiltersOrTransports( transports ),
+
+ // Main method
+ ajax: function( url, options ) {
+
+ // If url is an object, simulate pre-1.5 signature
+ if ( typeof url === "object" ) {
+ options = url;
+ url = undefined;
+ }
+
+ // Force options to be an object
+ options = options || {};
+
+ var transport,
+
+ // URL without anti-cache param
+ cacheURL,
+
+ // Response headers
+ responseHeadersString,
+ responseHeaders,
+
+ // timeout handle
+ timeoutTimer,
+
+ // Url cleanup var
+ urlAnchor,
+
+ // Request state (becomes false upon send and true upon completion)
+ completed,
+
+ // To know if global events are to be dispatched
+ fireGlobals,
+
+ // Loop variable
+ i,
+
+ // uncached part of the url
+ uncached,
+
+ // Create the final options object
+ s = jQuery.ajaxSetup( {}, options ),
+
+ // Callbacks context
+ callbackContext = s.context || s,
+
+ // Context for global events is callbackContext if it is a DOM node or jQuery collection
+ globalEventContext = s.context &&
+ ( callbackContext.nodeType || callbackContext.jquery ) ?
+ jQuery( callbackContext ) :
+ jQuery.event,
+
+ // Deferreds
+ deferred = jQuery.Deferred(),
+ completeDeferred = jQuery.Callbacks( "once memory" ),
+
+ // Status-dependent callbacks
+ statusCode = s.statusCode || {},
+
+ // Headers (they are sent all at once)
+ requestHeaders = {},
+ requestHeadersNames = {},
+
+ // Default abort message
+ strAbort = "canceled",
+
+ // Fake xhr
+ jqXHR = {
+ readyState: 0,
+
+ // Builds headers hashtable if needed
+ getResponseHeader: function( key ) {
+ var match;
+ if ( completed ) {
+ if ( !responseHeaders ) {
+ responseHeaders = {};
+ while ( ( match = rheaders.exec( responseHeadersString ) ) ) {
+ responseHeaders[ match[ 1 ].toLowerCase() ] = match[ 2 ];
+ }
+ }
+ match = responseHeaders[ key.toLowerCase() ];
+ }
+ return match == null ? null : match;
+ },
+
+ // Raw string
+ getAllResponseHeaders: function() {
+ return completed ? responseHeadersString : null;
+ },
+
+ // Caches the header
+ setRequestHeader: function( name, value ) {
+ if ( completed == null ) {
+ name = requestHeadersNames[ name.toLowerCase() ] =
+ requestHeadersNames[ name.toLowerCase() ] || name;
+ requestHeaders[ name ] = value;
+ }
+ return this;
+ },
+
+ // Overrides response content-type header
+ overrideMimeType: function( type ) {
+ if ( completed == null ) {
+ s.mimeType = type;
+ }
+ return this;
+ },
+
+ // Status-dependent callbacks
+ statusCode: function( map ) {
+ var code;
+ if ( map ) {
+ if ( completed ) {
+
+ // Execute the appropriate callbacks
+ jqXHR.always( map[ jqXHR.status ] );
+ } else {
+
+ // Lazy-add the new callbacks in a way that preserves old ones
+ for ( code in map ) {
+ statusCode[ code ] = [ statusCode[ code ], map[ code ] ];
+ }
+ }
+ }
+ return this;
+ },
+
+ // Cancel the request
+ abort: function( statusText ) {
+ var finalText = statusText || strAbort;
+ if ( transport ) {
+ transport.abort( finalText );
+ }
+ done( 0, finalText );
+ return this;
+ }
+ };
+
+ // Attach deferreds
+ deferred.promise( jqXHR );
+
+ // Add protocol if not provided (prefilters might expect it)
+ // Handle falsy url in the settings object (#10093: consistency with old signature)
+ // We also use the url parameter if available
+ s.url = ( ( url || s.url || location.href ) + "" )
+ .replace( rprotocol, location.protocol + "//" );
+
+ // Alias method option to type as per ticket #12004
+ s.type = options.method || options.type || s.method || s.type;
+
+ // Extract dataTypes list
+ s.dataTypes = ( s.dataType || "*" ).toLowerCase().match( rnothtmlwhite ) || [ "" ];
+
+ // A cross-domain request is in order when the origin doesn't match the current origin.
+ if ( s.crossDomain == null ) {
+ urlAnchor = document.createElement( "a" );
+
+ // Support: IE <=8 - 11, Edge 12 - 13
+ // IE throws exception on accessing the href property if url is malformed,
+ // e.g. http://example.com:80x/
+ try {
+ urlAnchor.href = s.url;
+
+ // Support: IE <=8 - 11 only
+ // Anchor's host property isn't correctly set when s.url is relative
+ urlAnchor.href = urlAnchor.href;
+ s.crossDomain = originAnchor.protocol + "//" + originAnchor.host !==
+ urlAnchor.protocol + "//" + urlAnchor.host;
+ } catch ( e ) {
+
+ // If there is an error parsing the URL, assume it is crossDomain,
+ // it can be rejected by the transport if it is invalid
+ s.crossDomain = true;
+ }
+ }
+
+ // Convert data if not already a string
+ if ( s.data && s.processData && typeof s.data !== "string" ) {
+ s.data = jQuery.param( s.data, s.traditional );
+ }
+
+ // Apply prefilters
+ inspectPrefiltersOrTransports( prefilters, s, options, jqXHR );
+
+ // If request was aborted inside a prefilter, stop there
+ if ( completed ) {
+ return jqXHR;
+ }
+
+ // We can fire global events as of now if asked to
+ // Don't fire events if jQuery.event is undefined in an AMD-usage scenario (#15118)
+ fireGlobals = jQuery.event && s.global;
+
+ // Watch for a new set of requests
+ if ( fireGlobals && jQuery.active++ === 0 ) {
+ jQuery.event.trigger( "ajaxStart" );
+ }
+
+ // Uppercase the type
+ s.type = s.type.toUpperCase();
+
+ // Determine if request has content
+ s.hasContent = !rnoContent.test( s.type );
+
+ // Save the URL in case we're toying with the If-Modified-Since
+ // and/or If-None-Match header later on
+ // Remove hash to simplify url manipulation
+ cacheURL = s.url.replace( rhash, "" );
+
+ // More options handling for requests with no content
+ if ( !s.hasContent ) {
+
+ // Remember the hash so we can put it back
+ uncached = s.url.slice( cacheURL.length );
+
+ // If data is available, append data to url
+ if ( s.data ) {
+ cacheURL += ( rquery.test( cacheURL ) ? "&" : "?" ) + s.data;
+
+ // #9682: remove data so that it's not used in an eventual retry
+ delete s.data;
+ }
+
+ // Add or update anti-cache param if needed
+ if ( s.cache === false ) {
+ cacheURL = cacheURL.replace( rantiCache, "$1" );
+ uncached = ( rquery.test( cacheURL ) ? "&" : "?" ) + "_=" + ( nonce++ ) + uncached;
+ }
+
+ // Put hash and anti-cache on the URL that will be requested (gh-1732)
+ s.url = cacheURL + uncached;
+
+ // Change '%20' to '+' if this is encoded form body content (gh-2658)
+ } else if ( s.data && s.processData &&
+ ( s.contentType || "" ).indexOf( "application/x-www-form-urlencoded" ) === 0 ) {
+ s.data = s.data.replace( r20, "+" );
+ }
+
+ // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
+ if ( s.ifModified ) {
+ if ( jQuery.lastModified[ cacheURL ] ) {
+ jqXHR.setRequestHeader( "If-Modified-Since", jQuery.lastModified[ cacheURL ] );
+ }
+ if ( jQuery.etag[ cacheURL ] ) {
+ jqXHR.setRequestHeader( "If-None-Match", jQuery.etag[ cacheURL ] );
+ }
+ }
+
+ // Set the correct header, if data is being sent
+ if ( s.data && s.hasContent && s.contentType !== false || options.contentType ) {
+ jqXHR.setRequestHeader( "Content-Type", s.contentType );
+ }
+
+ // Set the Accepts header for the server, depending on the dataType
+ jqXHR.setRequestHeader(
+ "Accept",
+ s.dataTypes[ 0 ] && s.accepts[ s.dataTypes[ 0 ] ] ?
+ s.accepts[ s.dataTypes[ 0 ] ] +
+ ( s.dataTypes[ 0 ] !== "*" ? ", " + allTypes + "; q=0.01" : "" ) :
+ s.accepts[ "*" ]
+ );
+
+ // Check for headers option
+ for ( i in s.headers ) {
+ jqXHR.setRequestHeader( i, s.headers[ i ] );
+ }
+
+ // Allow custom headers/mimetypes and early abort
+ if ( s.beforeSend &&
+ ( s.beforeSend.call( callbackContext, jqXHR, s ) === false || completed ) ) {
+
+ // Abort if not done already and return
+ return jqXHR.abort();
+ }
+
+ // Aborting is no longer a cancellation
+ strAbort = "abort";
+
+ // Install callbacks on deferreds
+ completeDeferred.add( s.complete );
+ jqXHR.done( s.success );
+ jqXHR.fail( s.error );
+
+ // Get transport
+ transport = inspectPrefiltersOrTransports( transports, s, options, jqXHR );
+
+ // If no transport, we auto-abort
+ if ( !transport ) {
+ done( -1, "No Transport" );
+ } else {
+ jqXHR.readyState = 1;
+
+ // Send global event
+ if ( fireGlobals ) {
+ globalEventContext.trigger( "ajaxSend", [ jqXHR, s ] );
+ }
+
+ // If request was aborted inside ajaxSend, stop there
+ if ( completed ) {
+ return jqXHR;
+ }
+
+ // Timeout
+ if ( s.async && s.timeout > 0 ) {
+ timeoutTimer = window.setTimeout( function() {
+ jqXHR.abort( "timeout" );
+ }, s.timeout );
+ }
+
+ try {
+ completed = false;
+ transport.send( requestHeaders, done );
+ } catch ( e ) {
+
+ // Rethrow post-completion exceptions
+ if ( completed ) {
+ throw e;
+ }
+
+ // Propagate others as results
+ done( -1, e );
+ }
+ }
+
+ // Callback for when everything is done
+ function done( status, nativeStatusText, responses, headers ) {
+ var isSuccess, success, error, response, modified,
+ statusText = nativeStatusText;
+
+ // Ignore repeat invocations
+ if ( completed ) {
+ return;
+ }
+
+ completed = true;
+
+ // Clear timeout if it exists
+ if ( timeoutTimer ) {
+ window.clearTimeout( timeoutTimer );
+ }
+
+ // Dereference transport for early garbage collection
+ // (no matter how long the jqXHR object will be used)
+ transport = undefined;
+
+ // Cache response headers
+ responseHeadersString = headers || "";
+
+ // Set readyState
+ jqXHR.readyState = status > 0 ? 4 : 0;
+
+ // Determine if successful
+ isSuccess = status >= 200 && status < 300 || status === 304;
+
+ // Get response data
+ if ( responses ) {
+ response = ajaxHandleResponses( s, jqXHR, responses );
+ }
+
+ // Convert no matter what (that way responseXXX fields are always set)
+ response = ajaxConvert( s, response, jqXHR, isSuccess );
+
+ // If successful, handle type chaining
+ if ( isSuccess ) {
+
+ // Set the If-Modified-Since and/or If-None-Match header, if in ifModified mode.
+ if ( s.ifModified ) {
+ modified = jqXHR.getResponseHeader( "Last-Modified" );
+ if ( modified ) {
+ jQuery.lastModified[ cacheURL ] = modified;
+ }
+ modified = jqXHR.getResponseHeader( "etag" );
+ if ( modified ) {
+ jQuery.etag[ cacheURL ] = modified;
+ }
+ }
+
+ // if no content
+ if ( status === 204 || s.type === "HEAD" ) {
+ statusText = "nocontent";
+
+ // if not modified
+ } else if ( status === 304 ) {
+ statusText = "notmodified";
+
+ // If we have data, let's convert it
+ } else {
+ statusText = response.state;
+ success = response.data;
+ error = response.error;
+ isSuccess = !error;
+ }
+ } else {
+
+ // Extract error from statusText and normalize for non-aborts
+ error = statusText;
+ if ( status || !statusText ) {
+ statusText = "error";
+ if ( status < 0 ) {
+ status = 0;
+ }
+ }
+ }
+
+ // Set data for the fake xhr object
+ jqXHR.status = status;
+ jqXHR.statusText = ( nativeStatusText || statusText ) + "";
+
+ // Success/Error
+ if ( isSuccess ) {
+ deferred.resolveWith( callbackContext, [ success, statusText, jqXHR ] );
+ } else {
+ deferred.rejectWith( callbackContext, [ jqXHR, statusText, error ] );
+ }
+
+ // Status-dependent callbacks
+ jqXHR.statusCode( statusCode );
+ statusCode = undefined;
+
+ if ( fireGlobals ) {
+ globalEventContext.trigger( isSuccess ? "ajaxSuccess" : "ajaxError",
+ [ jqXHR, s, isSuccess ? success : error ] );
+ }
+
+ // Complete
+ completeDeferred.fireWith( callbackContext, [ jqXHR, statusText ] );
+
+ if ( fireGlobals ) {
+ globalEventContext.trigger( "ajaxComplete", [ jqXHR, s ] );
+
+ // Handle the global AJAX counter
+ if ( !( --jQuery.active ) ) {
+ jQuery.event.trigger( "ajaxStop" );
+ }
+ }
+ }
+
+ return jqXHR;
+ },
+
+ getJSON: function( url, data, callback ) {
+ return jQuery.get( url, data, callback, "json" );
+ },
+
+ getScript: function( url, callback ) {
+ return jQuery.get( url, undefined, callback, "script" );
+ }
+} );
+
+jQuery.each( [ "get", "post" ], function( i, method ) {
+ jQuery[ method ] = function( url, data, callback, type ) {
+
+ // Shift arguments if data argument was omitted
+ if ( jQuery.isFunction( data ) ) {
+ type = type || callback;
+ callback = data;
+ data = undefined;
+ }
+
+ // The url can be an options object (which then must have .url)
+ return jQuery.ajax( jQuery.extend( {
+ url: url,
+ type: method,
+ dataType: type,
+ data: data,
+ success: callback
+ }, jQuery.isPlainObject( url ) && url ) );
+ };
+} );
+
+
+jQuery._evalUrl = function( url ) {
+ return jQuery.ajax( {
+ url: url,
+
+ // Make this explicit, since user can override this through ajaxSetup (#11264)
+ type: "GET",
+ dataType: "script",
+ cache: true,
+ async: false,
+ global: false,
+ "throws": true
+ } );
+};
+
+
+jQuery.fn.extend( {
+ wrapAll: function( html ) {
+ var wrap;
+
+ if ( this[ 0 ] ) {
+ if ( jQuery.isFunction( html ) ) {
+ html = html.call( this[ 0 ] );
+ }
+
+ // The elements to wrap the target around
+ wrap = jQuery( html, this[ 0 ].ownerDocument ).eq( 0 ).clone( true );
+
+ if ( this[ 0 ].parentNode ) {
+ wrap.insertBefore( this[ 0 ] );
+ }
+
+ wrap.map( function() {
+ var elem = this;
+
+ while ( elem.firstElementChild ) {
+ elem = elem.firstElementChild;
+ }
+
+ return elem;
+ } ).append( this );
+ }
+
+ return this;
+ },
+
+ wrapInner: function( html ) {
+ if ( jQuery.isFunction( html ) ) {
+ return this.each( function( i ) {
+ jQuery( this ).wrapInner( html.call( this, i ) );
+ } );
+ }
+
+ return this.each( function() {
+ var self = jQuery( this ),
+ contents = self.contents();
+
+ if ( contents.length ) {
+ contents.wrapAll( html );
+
+ } else {
+ self.append( html );
+ }
+ } );
+ },
+
+ wrap: function( html ) {
+ var isFunction = jQuery.isFunction( html );
+
+ return this.each( function( i ) {
+ jQuery( this ).wrapAll( isFunction ? html.call( this, i ) : html );
+ } );
+ },
+
+ unwrap: function( selector ) {
+ this.parent( selector ).not( "body" ).each( function() {
+ jQuery( this ).replaceWith( this.childNodes );
+ } );
+ return this;
+ }
+} );
+
+
+jQuery.expr.pseudos.hidden = function( elem ) {
+ return !jQuery.expr.pseudos.visible( elem );
+};
+jQuery.expr.pseudos.visible = function( elem ) {
+ return !!( elem.offsetWidth || elem.offsetHeight || elem.getClientRects().length );
+};
+
+
+
+
+jQuery.ajaxSettings.xhr = function() {
+ try {
+ return new window.XMLHttpRequest();
+ } catch ( e ) {}
+};
+
+var xhrSuccessStatus = {
+
+ // File protocol always yields status code 0, assume 200
+ 0: 200,
+
+ // Support: IE <=9 only
+ // #1450: sometimes IE returns 1223 when it should be 204
+ 1223: 204
+ },
+ xhrSupported = jQuery.ajaxSettings.xhr();
+
+support.cors = !!xhrSupported && ( "withCredentials" in xhrSupported );
+support.ajax = xhrSupported = !!xhrSupported;
+
+jQuery.ajaxTransport( function( options ) {
+ var callback, errorCallback;
+
+ // Cross domain only allowed if supported through XMLHttpRequest
+ if ( support.cors || xhrSupported && !options.crossDomain ) {
+ return {
+ send: function( headers, complete ) {
+ var i,
+ xhr = options.xhr();
+
+ xhr.open(
+ options.type,
+ options.url,
+ options.async,
+ options.username,
+ options.password
+ );
+
+ // Apply custom fields if provided
+ if ( options.xhrFields ) {
+ for ( i in options.xhrFields ) {
+ xhr[ i ] = options.xhrFields[ i ];
+ }
+ }
+
+ // Override mime type if needed
+ if ( options.mimeType && xhr.overrideMimeType ) {
+ xhr.overrideMimeType( options.mimeType );
+ }
+
+ // X-Requested-With header
+ // For cross-domain requests, seeing as conditions for a preflight are
+ // akin to a jigsaw puzzle, we simply never set it to be sure.
+ // (it can always be set on a per-request basis or even using ajaxSetup)
+ // For same-domain requests, won't change header if already provided.
+ if ( !options.crossDomain && !headers[ "X-Requested-With" ] ) {
+ headers[ "X-Requested-With" ] = "XMLHttpRequest";
+ }
+
+ // Set headers
+ for ( i in headers ) {
+ xhr.setRequestHeader( i, headers[ i ] );
+ }
+
+ // Callback
+ callback = function( type ) {
+ return function() {
+ if ( callback ) {
+ callback = errorCallback = xhr.onload =
+ xhr.onerror = xhr.onabort = xhr.onreadystatechange = null;
+
+ if ( type === "abort" ) {
+ xhr.abort();
+ } else if ( type === "error" ) {
+
+ // Support: IE <=9 only
+ // On a manual native abort, IE9 throws
+ // errors on any property access that is not readyState
+ if ( typeof xhr.status !== "number" ) {
+ complete( 0, "error" );
+ } else {
+ complete(
+
+ // File: protocol always yields status 0; see #8605, #14207
+ xhr.status,
+ xhr.statusText
+ );
+ }
+ } else {
+ complete(
+ xhrSuccessStatus[ xhr.status ] || xhr.status,
+ xhr.statusText,
+
+ // Support: IE <=9 only
+ // IE9 has no XHR2 but throws on binary (trac-11426)
+ // For XHR2 non-text, let the caller handle it (gh-2498)
+ ( xhr.responseType || "text" ) !== "text" ||
+ typeof xhr.responseText !== "string" ?
+ { binary: xhr.response } :
+ { text: xhr.responseText },
+ xhr.getAllResponseHeaders()
+ );
+ }
+ }
+ };
+ };
+
+ // Listen to events
+ xhr.onload = callback();
+ errorCallback = xhr.onerror = callback( "error" );
+
+ // Support: IE 9 only
+ // Use onreadystatechange to replace onabort
+ // to handle uncaught aborts
+ if ( xhr.onabort !== undefined ) {
+ xhr.onabort = errorCallback;
+ } else {
+ xhr.onreadystatechange = function() {
+
+ // Check readyState before timeout as it changes
+ if ( xhr.readyState === 4 ) {
+
+ // Allow onerror to be called first,
+ // but that will not handle a native abort
+ // Also, save errorCallback to a variable
+ // as xhr.onerror cannot be accessed
+ window.setTimeout( function() {
+ if ( callback ) {
+ errorCallback();
+ }
+ } );
+ }
+ };
+ }
+
+ // Create the abort callback
+ callback = callback( "abort" );
+
+ try {
+
+ // Do send the request (this may raise an exception)
+ xhr.send( options.hasContent && options.data || null );
+ } catch ( e ) {
+
+ // #14683: Only rethrow if this hasn't been notified as an error yet
+ if ( callback ) {
+ throw e;
+ }
+ }
+ },
+
+ abort: function() {
+ if ( callback ) {
+ callback();
+ }
+ }
+ };
+ }
+} );
+
+
+
+
+// Prevent auto-execution of scripts when no explicit dataType was provided (See gh-2432)
+jQuery.ajaxPrefilter( function( s ) {
+ if ( s.crossDomain ) {
+ s.contents.script = false;
+ }
+} );
+
+// Install script dataType
+jQuery.ajaxSetup( {
+ accepts: {
+ script: "text/javascript, application/javascript, " +
+ "application/ecmascript, application/x-ecmascript"
+ },
+ contents: {
+ script: /\b(?:java|ecma)script\b/
+ },
+ converters: {
+ "text script": function( text ) {
+ jQuery.globalEval( text );
+ return text;
+ }
+ }
+} );
+
+// Handle cache's special case and crossDomain
+jQuery.ajaxPrefilter( "script", function( s ) {
+ if ( s.cache === undefined ) {
+ s.cache = false;
+ }
+ if ( s.crossDomain ) {
+ s.type = "GET";
+ }
+} );
+
+// Bind script tag hack transport
+jQuery.ajaxTransport( "script", function( s ) {
+
+ // This transport only deals with cross domain requests
+ if ( s.crossDomain ) {
+ var script, callback;
+ return {
+ send: function( _, complete ) {
+ script = jQuery( "<script>" ).prop( {
+ charset: s.scriptCharset,
+ src: s.url
+ } ).on(
+ "load error",
+ callback = function( evt ) {
+ script.remove();
+ callback = null;
+ if ( evt ) {
+ complete( evt.type === "error" ? 404 : 200, evt.type );
+ }
+ }
+ );
+
+ // Use native DOM manipulation to avoid our domManip AJAX trickery
+ document.head.appendChild( script[ 0 ] );
+ },
+ abort: function() {
+ if ( callback ) {
+ callback();
+ }
+ }
+ };
+ }
+} );
+
+
+
+
+var oldCallbacks = [],
+ rjsonp = /(=)\?(?=&|$)|\?\?/;
+
+// Default jsonp settings
+jQuery.ajaxSetup( {
+ jsonp: "callback",
+ jsonpCallback: function() {
+ var callback = oldCallbacks.pop() || ( jQuery.expando + "_" + ( nonce++ ) );
+ this[ callback ] = true;
+ return callback;
+ }
+} );
+
+// Detect, normalize options and install callbacks for jsonp requests
+jQuery.ajaxPrefilter( "json jsonp", function( s, originalSettings, jqXHR ) {
+
+ var callbackName, overwritten, responseContainer,
+ jsonProp = s.jsonp !== false && ( rjsonp.test( s.url ) ?
+ "url" :
+ typeof s.data === "string" &&
+ ( s.contentType || "" )
+ .indexOf( "application/x-www-form-urlencoded" ) === 0 &&
+ rjsonp.test( s.data ) && "data"
+ );
+
+ // Handle iff the expected data type is "jsonp" or we have a parameter to set
+ if ( jsonProp || s.dataTypes[ 0 ] === "jsonp" ) {
+
+ // Get callback name, remembering preexisting value associated with it
+ callbackName = s.jsonpCallback = jQuery.isFunction( s.jsonpCallback ) ?
+ s.jsonpCallback() :
+ s.jsonpCallback;
+
+ // Insert callback into url or form data
+ if ( jsonProp ) {
+ s[ jsonProp ] = s[ jsonProp ].replace( rjsonp, "$1" + callbackName );
+ } else if ( s.jsonp !== false ) {
+ s.url += ( rquery.test( s.url ) ? "&" : "?" ) + s.jsonp + "=" + callbackName;
+ }
+
+ // Use data converter to retrieve json after script execution
+ s.converters[ "script json" ] = function() {
+ if ( !responseContainer ) {
+ jQuery.error( callbackName + " was not called" );
+ }
+ return responseContainer[ 0 ];
+ };
+
+ // Force json dataType
+ s.dataTypes[ 0 ] = "json";
+
+ // Install callback
+ overwritten = window[ callbackName ];
+ window[ callbackName ] = function() {
+ responseContainer = arguments;
+ };
+
+ // Clean-up function (fires after converters)
+ jqXHR.always( function() {
+
+ // If previous value didn't exist - remove it
+ if ( overwritten === undefined ) {
+ jQuery( window ).removeProp( callbackName );
+
+ // Otherwise restore preexisting value
+ } else {
+ window[ callbackName ] = overwritten;
+ }
+
+ // Save back as free
+ if ( s[ callbackName ] ) {
+
+ // Make sure that re-using the options doesn't screw things around
+ s.jsonpCallback = originalSettings.jsonpCallback;
+
+ // Save the callback name for future use
+ oldCallbacks.push( callbackName );
+ }
+
+ // Call if it was a function and we have a response
+ if ( responseContainer && jQuery.isFunction( overwritten ) ) {
+ overwritten( responseContainer[ 0 ] );
+ }
+
+ responseContainer = overwritten = undefined;
+ } );
+
+ // Delegate to script
+ return "script";
+ }
+} );
+
+
+
+
+// Support: Safari 8 only
+// In Safari 8 documents created via document.implementation.createHTMLDocument
+// collapse sibling forms: the second one becomes a child of the first one.
+// Because of that, this security measure has to be disabled in Safari 8.
+// https://bugs.webkit.org/show_bug.cgi?id=137337
+support.createHTMLDocument = ( function() {
+ var body = document.implementation.createHTMLDocument( "" ).body;
+ body.innerHTML = "<form></form><form></form>";
+ return body.childNodes.length === 2;
+} )();
+
+
+// Argument "data" should be string of html
+// context (optional): If specified, the fragment will be created in this context,
+// defaults to document
+// keepScripts (optional): If true, will include scripts passed in the html string
+jQuery.parseHTML = function( data, context, keepScripts ) {
+ if ( typeof data !== "string" ) {
+ return [];
+ }
+ if ( typeof context === "boolean" ) {
+ keepScripts = context;
+ context = false;
+ }
+
+ var base, parsed, scripts;
+
+ if ( !context ) {
+
+ // Stop scripts or inline event handlers from being executed immediately
+ // by using document.implementation
+ if ( support.createHTMLDocument ) {
+ context = document.implementation.createHTMLDocument( "" );
+
+ // Set the base href for the created document
+ // so any parsed elements with URLs
+ // are based on the document's URL (gh-2965)
+ base = context.createElement( "base" );
+ base.href = document.location.href;
+ context.head.appendChild( base );
+ } else {
+ context = document;
+ }
+ }
+
+ parsed = rsingleTag.exec( data );
+ scripts = !keepScripts && [];
+
+ // Single tag
+ if ( parsed ) {
+ return [ context.createElement( parsed[ 1 ] ) ];
+ }
+
+ parsed = buildFragment( [ data ], context, scripts );
+
+ if ( scripts && scripts.length ) {
+ jQuery( scripts ).remove();
+ }
+
+ return jQuery.merge( [], parsed.childNodes );
+};
+
+
+/**
+ * Load a url into a page
+ */
+jQuery.fn.load = function( url, params, callback ) {
+ var selector, type, response,
+ self = this,
+ off = url.indexOf( " " );
+
+ if ( off > -1 ) {
+ selector = stripAndCollapse( url.slice( off ) );
+ url = url.slice( 0, off );
+ }
+
+ // If it's a function
+ if ( jQuery.isFunction( params ) ) {
+
+ // We assume that it's the callback
+ callback = params;
+ params = undefined;
+
+ // Otherwise, build a param string
+ } else if ( params && typeof params === "object" ) {
+ type = "POST";
+ }
+
+ // If we have elements to modify, make the request
+ if ( self.length > 0 ) {
+ jQuery.ajax( {
+ url: url,
+
+ // If "type" variable is undefined, then "GET" method will be used.
+ // Make value of this field explicit since
+ // user can override it through ajaxSetup method
+ type: type || "GET",
+ dataType: "html",
+ data: params
+ } ).done( function( responseText ) {
+
+ // Save response for use in complete callback
+ response = arguments;
+
+ self.html( selector ?
+
+ // If a selector was specified, locate the right elements in a dummy div
+ // Exclude scripts to avoid IE 'Permission Denied' errors
+ jQuery( "<div>" ).append( jQuery.parseHTML( responseText ) ).find( selector ) :
+
+ // Otherwise use the full result
+ responseText );
+
+ // If the request succeeds, this function gets "data", "status", "jqXHR"
+ // but they are ignored because response was set above.
+ // If it fails, this function gets "jqXHR", "status", "error"
+ } ).always( callback && function( jqXHR, status ) {
+ self.each( function() {
+ callback.apply( this, response || [ jqXHR.responseText, status, jqXHR ] );
+ } );
+ } );
+ }
+
+ return this;
+};
+
+
+
+
+// Attach a bunch of functions for handling common AJAX events
+jQuery.each( [
+ "ajaxStart",
+ "ajaxStop",
+ "ajaxComplete",
+ "ajaxError",
+ "ajaxSuccess",
+ "ajaxSend"
+], function( i, type ) {
+ jQuery.fn[ type ] = function( fn ) {
+ return this.on( type, fn );
+ };
+} );
+
+
+
+
+jQuery.expr.pseudos.animated = function( elem ) {
+ return jQuery.grep( jQuery.timers, function( fn ) {
+ return elem === fn.elem;
+ } ).length;
+};
+
+
+
+
+jQuery.offset = {
+ setOffset: function( elem, options, i ) {
+ var curPosition, curLeft, curCSSTop, curTop, curOffset, curCSSLeft, calculatePosition,
+ position = jQuery.css( elem, "position" ),
+ curElem = jQuery( elem ),
+ props = {};
+
+ // Set position first, in-case top/left are set even on static elem
+ if ( position === "static" ) {
+ elem.style.position = "relative";
+ }
+
+ curOffset = curElem.offset();
+ curCSSTop = jQuery.css( elem, "top" );
+ curCSSLeft = jQuery.css( elem, "left" );
+ calculatePosition = ( position === "absolute" || position === "fixed" ) &&
+ ( curCSSTop + curCSSLeft ).indexOf( "auto" ) > -1;
+
+ // Need to be able to calculate position if either
+ // top or left is auto and position is either absolute or fixed
+ if ( calculatePosition ) {
+ curPosition = curElem.position();
+ curTop = curPosition.top;
+ curLeft = curPosition.left;
+
+ } else {
+ curTop = parseFloat( curCSSTop ) || 0;
+ curLeft = parseFloat( curCSSLeft ) || 0;
+ }
+
+ if ( jQuery.isFunction( options ) ) {
+
+ // Use jQuery.extend here to allow modification of coordinates argument (gh-1848)
+ options = options.call( elem, i, jQuery.extend( {}, curOffset ) );
+ }
+
+ if ( options.top != null ) {
+ props.top = ( options.top - curOffset.top ) + curTop;
+ }
+ if ( options.left != null ) {
+ props.left = ( options.left - curOffset.left ) + curLeft;
+ }
+
+ if ( "using" in options ) {
+ options.using.call( elem, props );
+
+ } else {
+ curElem.css( props );
+ }
+ }
+};
+
+jQuery.fn.extend( {
+ offset: function( options ) {
+
+ // Preserve chaining for setter
+ if ( arguments.length ) {
+ return options === undefined ?
+ this :
+ this.each( function( i ) {
+ jQuery.offset.setOffset( this, options, i );
+ } );
+ }
+
+ var doc, docElem, rect, win,
+ elem = this[ 0 ];
+
+ if ( !elem ) {
+ return;
+ }
+
+ // Return zeros for disconnected and hidden (display: none) elements (gh-2310)
+ // Support: IE <=11 only
+ // Running getBoundingClientRect on a
+ // disconnected node in IE throws an error
+ if ( !elem.getClientRects().length ) {
+ return { top: 0, left: 0 };
+ }
+
+ rect = elem.getBoundingClientRect();
+
+ doc = elem.ownerDocument;
+ docElem = doc.documentElement;
+ win = doc.defaultView;
+
+ return {
+ top: rect.top + win.pageYOffset - docElem.clientTop,
+ left: rect.left + win.pageXOffset - docElem.clientLeft
+ };
+ },
+
+ position: function() {
+ if ( !this[ 0 ] ) {
+ return;
+ }
+
+ var offsetParent, offset,
+ elem = this[ 0 ],
+ parentOffset = { top: 0, left: 0 };
+
+ // Fixed elements are offset from window (parentOffset = {top:0, left: 0},
+ // because it is its only offset parent
+ if ( jQuery.css( elem, "position" ) === "fixed" ) {
+
+ // Assume getBoundingClientRect is there when computed position is fixed
+ offset = elem.getBoundingClientRect();
+
+ } else {
+
+ // Get *real* offsetParent
+ offsetParent = this.offsetParent();
+
+ // Get correct offsets
+ offset = this.offset();
+ if ( !nodeName( offsetParent[ 0 ], "html" ) ) {
+ parentOffset = offsetParent.offset();
+ }
+
+ // Add offsetParent borders
+ parentOffset = {
+ top: parentOffset.top + jQuery.css( offsetParent[ 0 ], "borderTopWidth", true ),
+ left: parentOffset.left + jQuery.css( offsetParent[ 0 ], "borderLeftWidth", true )
+ };
+ }
+
+ // Subtract parent offsets and element margins
+ return {
+ top: offset.top - parentOffset.top - jQuery.css( elem, "marginTop", true ),
+ left: offset.left - parentOffset.left - jQuery.css( elem, "marginLeft", true )
+ };
+ },
+
+ // This method will return documentElement in the following cases:
+ // 1) For the element inside the iframe without offsetParent, this method will return
+ // documentElement of the parent window
+ // 2) For the hidden or detached element
+ // 3) For body or html element, i.e. in case of the html node - it will return itself
+ //
+ // but those exceptions were never presented as a real life use-cases
+ // and might be considered as more preferable results.
+ //
+ // This logic, however, is not guaranteed and can change at any point in the future
+ offsetParent: function() {
+ return this.map( function() {
+ var offsetParent = this.offsetParent;
+
+ while ( offsetParent && jQuery.css( offsetParent, "position" ) === "static" ) {
+ offsetParent = offsetParent.offsetParent;
+ }
+
+ return offsetParent || documentElement;
+ } );
+ }
+} );
+
+// Create scrollLeft and scrollTop methods
+jQuery.each( { scrollLeft: "pageXOffset", scrollTop: "pageYOffset" }, function( method, prop ) {
+ var top = "pageYOffset" === prop;
+
+ jQuery.fn[ method ] = function( val ) {
+ return access( this, function( elem, method, val ) {
+
+ // Coalesce documents and windows
+ var win;
+ if ( jQuery.isWindow( elem ) ) {
+ win = elem;
+ } else if ( elem.nodeType === 9 ) {
+ win = elem.defaultView;
+ }
+
+ if ( val === undefined ) {
+ return win ? win[ prop ] : elem[ method ];
+ }
+
+ if ( win ) {
+ win.scrollTo(
+ !top ? val : win.pageXOffset,
+ top ? val : win.pageYOffset
+ );
+
+ } else {
+ elem[ method ] = val;
+ }
+ }, method, val, arguments.length );
+ };
+} );
+
+// Support: Safari <=7 - 9.1, Chrome <=37 - 49
+// Add the top/left cssHooks using jQuery.fn.position
+// Webkit bug: https://bugs.webkit.org/show_bug.cgi?id=29084
+// Blink bug: https://bugs.chromium.org/p/chromium/issues/detail?id=589347
+// getComputedStyle returns percent when specified for top/left/bottom/right;
+// rather than make the css module depend on the offset module, just check for it here
+jQuery.each( [ "top", "left" ], function( i, prop ) {
+ jQuery.cssHooks[ prop ] = addGetHookIf( support.pixelPosition,
+ function( elem, computed ) {
+ if ( computed ) {
+ computed = curCSS( elem, prop );
+
+ // If curCSS returns percentage, fallback to offset
+ return rnumnonpx.test( computed ) ?
+ jQuery( elem ).position()[ prop ] + "px" :
+ computed;
+ }
+ }
+ );
+} );
+
+
+// Create innerHeight, innerWidth, height, width, outerHeight and outerWidth methods
+jQuery.each( { Height: "height", Width: "width" }, function( name, type ) {
+ jQuery.each( { padding: "inner" + name, content: type, "": "outer" + name },
+ function( defaultExtra, funcName ) {
+
+ // Margin is only for outerHeight, outerWidth
+ jQuery.fn[ funcName ] = function( margin, value ) {
+ var chainable = arguments.length && ( defaultExtra || typeof margin !== "boolean" ),
+ extra = defaultExtra || ( margin === true || value === true ? "margin" : "border" );
+
+ return access( this, function( elem, type, value ) {
+ var doc;
+
+ if ( jQuery.isWindow( elem ) ) {
+
+ // $( window ).outerWidth/Height return w/h including scrollbars (gh-1729)
+ return funcName.indexOf( "outer" ) === 0 ?
+ elem[ "inner" + name ] :
+ elem.document.documentElement[ "client" + name ];
+ }
+
+ // Get document width or height
+ if ( elem.nodeType === 9 ) {
+ doc = elem.documentElement;
+
+ // Either scroll[Width/Height] or offset[Width/Height] or client[Width/Height],
+ // whichever is greatest
+ return Math.max(
+ elem.body[ "scroll" + name ], doc[ "scroll" + name ],
+ elem.body[ "offset" + name ], doc[ "offset" + name ],
+ doc[ "client" + name ]
+ );
+ }
+
+ return value === undefined ?
+
+ // Get width or height on the element, requesting but not forcing parseFloat
+ jQuery.css( elem, type, extra ) :
+
+ // Set width or height on the element
+ jQuery.style( elem, type, value, extra );
+ }, type, chainable ? margin : undefined, chainable );
+ };
+ } );
+} );
+
+
+jQuery.fn.extend( {
+
+ bind: function( types, data, fn ) {
+ return this.on( types, null, data, fn );
+ },
+ unbind: function( types, fn ) {
+ return this.off( types, null, fn );
+ },
+
+ delegate: function( selector, types, data, fn ) {
+ return this.on( types, selector, data, fn );
+ },
+ undelegate: function( selector, types, fn ) {
+
+ // ( namespace ) or ( selector, types [, fn] )
+ return arguments.length === 1 ?
+ this.off( selector, "**" ) :
+ this.off( types, selector || "**", fn );
+ }
+} );
+
+jQuery.holdReady = function( hold ) {
+ if ( hold ) {
+ jQuery.readyWait++;
+ } else {
+ jQuery.ready( true );
+ }
+};
+jQuery.isArray = Array.isArray;
+jQuery.parseJSON = JSON.parse;
+jQuery.nodeName = nodeName;
+
+
+
+
+// Register as a named AMD module, since jQuery can be concatenated with other
+// files that may use define, but not via a proper concatenation script that
+// understands anonymous AMD modules. A named AMD is safest and most robust
+// way to register. Lowercase jquery is used because AMD module names are
+// derived from file names, and jQuery is normally delivered in a lowercase
+// file name. Do this after creating the global so that if an AMD module wants
+// to call noConflict to hide this version of jQuery, it will work.
+
+// Note that for maximum portability, libraries that are not jQuery should
+// declare themselves as anonymous modules, and avoid setting a global if an
+// AMD loader is present. jQuery is a special case. For more information, see
+// https://github.com/jrburke/requirejs/wiki/Updating-existing-libraries#wiki-anon
+
+if ( typeof define === "function" && define.amd ) {
+ define( "jquery", [], function() {
+ return jQuery;
+ } );
+}
+
+
+
+
+var
+
+ // Map over jQuery in case of overwrite
+ _jQuery = window.jQuery,
+
+ // Map over the $ in case of overwrite
+ _$ = window.$;
+
+jQuery.noConflict = function( deep ) {
+ if ( window.$ === jQuery ) {
+ window.$ = _$;
+ }
+
+ if ( deep && window.jQuery === jQuery ) {
+ window.jQuery = _jQuery;
+ }
+
+ return jQuery;
+};
+
+// Expose jQuery and $ identifiers, even in AMD
+// (#7102#comment:10, https://github.com/jquery/jquery/pull/557)
+// and CommonJS for browser emulators (#13566)
+if ( !noGlobal ) {
+ window.jQuery = window.$ = jQuery;
+}
+
+
+
+
+return jQuery;
+} );
Added: www-releases/trunk/8.0.0/docs/_static/lines.gif
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/lines.gif?rev=356539&view=auto
==============================================================================
Binary file - no diff available.
Propchange: www-releases/trunk/8.0.0/docs/_static/lines.gif
------------------------------------------------------------------------------
svn:mime-type = application/octet-stream
Added: www-releases/trunk/8.0.0/docs/_static/llvm-theme.css
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/llvm-theme.css?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/llvm-theme.css (added)
+++ www-releases/trunk/8.0.0/docs/_static/llvm-theme.css Wed Mar 20 02:13:27 2019
@@ -0,0 +1,371 @@
+/*
+ * sphinxdoc.css_t
+ * ~~~~~~~~~~~~~~~
+ *
+ * Sphinx stylesheet -- sphinxdoc theme. Originally created by
+ * Armin Ronacher for Werkzeug.
+ *
+ * :copyright: Copyright 2007-2010 by the Sphinx team, see AUTHORS.
+ * :license: BSD, see LICENSE for details.
+ *
+ */
+
+ at import url("basic.css");
+
+/* -- page layout ----------------------------------------------------------- */
+
+body {
+ font-family: 'Lucida Grande', 'Lucida Sans Unicode', 'Geneva',
+ 'Verdana', sans-serif;
+ font-size: 14px;
+ line-height: 150%;
+ text-align: center;
+ background-color: #BFD1D4;
+ color: black;
+ padding: 0;
+ border: 1px solid #aaa;
+
+ margin: 0px 80px 0px 80px;
+ min-width: 740px;
+}
+
+div.logo {
+ background-color: white;
+ text-align: left;
+ padding: 10px 10px 15px 15px;
+}
+
+div.document {
+ background-color: white;
+ text-align: left;
+ background-image: url(contents.png);
+ background-repeat: repeat-x;
+}
+
+div.bodywrapper {
+ margin: 0 240px 0 0;
+ border-right: 1px solid #ccc;
+}
+
+div.body {
+ margin: 0;
+ padding: 0.5em 20px 20px 20px;
+}
+
+div.related {
+ font-size: 1em;
+}
+
+div.related ul {
+ background-image: url(navigation.png);
+ height: 2em;
+ border-top: 1px solid #ddd;
+ border-bottom: 1px solid #ddd;
+}
+
+div.related ul li {
+ margin: 0;
+ padding: 0;
+ height: 2em;
+ float: left;
+}
+
+div.related ul li.right {
+ float: right;
+ margin-right: 5px;
+}
+
+div.related ul li a {
+ margin: 0;
+ padding: 0 5px 0 5px;
+ line-height: 1.75em;
+ color: #EE9816;
+}
+
+div.related ul li a:hover {
+ color: #3CA8E7;
+}
+
+div.sphinxsidebarwrapper {
+ padding: 0;
+}
+
+div.sphinxsidebar {
+ margin: 0;
+ padding: 0.5em 15px 15px 0;
+ width: 210px;
+ float: right;
+ font-size: 1em;
+ text-align: left;
+}
+
+div.sphinxsidebar h3, div.sphinxsidebar h4 {
+ margin: 1em 0 0.5em 0;
+ font-size: 1em;
+ padding: 0.1em 0 0.1em 0.5em;
+ color: white;
+ border: 1px solid #86989B;
+ background-color: #AFC1C4;
+}
+
+div.sphinxsidebar h3 a {
+ color: white;
+}
+
+div.sphinxsidebar ul {
+ padding-left: 1.5em;
+ margin-top: 7px;
+ padding: 0;
+ line-height: 130%;
+}
+
+div.sphinxsidebar ul ul {
+ margin-left: 20px;
+}
+
+div.footer {
+ background-color: #E3EFF1;
+ color: #86989B;
+ padding: 3px 8px 3px 0;
+ clear: both;
+ font-size: 0.8em;
+ text-align: right;
+}
+
+div.footer a {
+ color: #86989B;
+ text-decoration: underline;
+}
+
+/* -- body styles ----------------------------------------------------------- */
+
+p {
+ margin: 0.8em 0 0.5em 0;
+}
+
+a {
+ color: #CA7900;
+ text-decoration: none;
+}
+
+a:hover {
+ color: #2491CF;
+}
+
+div.body p a{
+ text-decoration: underline;
+}
+
+h1 {
+ margin: 0;
+ padding: 0.7em 0 0.3em 0;
+ font-size: 1.5em;
+ color: #11557C;
+}
+
+h2 {
+ margin: 1.3em 0 0.2em 0;
+ font-size: 1.35em;
+ padding: 0;
+}
+
+h3 {
+ margin: 1em 0 -0.3em 0;
+ font-size: 1.2em;
+}
+
+h3 a:hover {
+ text-decoration: underline;
+}
+
+div.body h1 a, div.body h2 a, div.body h3 a, div.body h4 a, div.body h5 a, div.body h6 a {
+ color: black!important;
+}
+
+div.body h1,
+div.body h2,
+div.body h3,
+div.body h4,
+div.body h5,
+div.body h6 {
+ background-color: #f2f2f2;
+ font-weight: normal;
+ color: #20435c;
+ border-bottom: 1px solid #ccc;
+ margin: 20px -20px 10px -20px;
+ padding: 3px 0 3px 10px;
+}
+
+div.body h1 { margin-top: 0; font-size: 200%; }
+div.body h2 { font-size: 160%; }
+div.body h3 { font-size: 140%; }
+div.body h4 { font-size: 120%; }
+div.body h5 { font-size: 110%; }
+div.body h6 { font-size: 100%; }
+
+h1 a.anchor, h2 a.anchor, h3 a.anchor, h4 a.anchor, h5 a.anchor, h6 a.anchor {
+ display: none;
+ margin: 0 0 0 0.3em;
+ padding: 0 0.2em 0 0.2em;
+ color: #aaa!important;
+}
+
+h1:hover a.anchor, h2:hover a.anchor, h3:hover a.anchor, h4:hover a.anchor,
+h5:hover a.anchor, h6:hover a.anchor {
+ display: inline;
+}
+
+h1 a.anchor:hover, h2 a.anchor:hover, h3 a.anchor:hover, h4 a.anchor:hover,
+h5 a.anchor:hover, h6 a.anchor:hover {
+ color: #777;
+ background-color: #eee;
+}
+
+a.headerlink {
+ color: #c60f0f!important;
+ font-size: 1em;
+ margin-left: 6px;
+ padding: 0 4px 0 4px;
+ text-decoration: none!important;
+}
+
+a.headerlink:hover {
+ background-color: #ccc;
+ color: white!important;
+}
+
+cite, code, tt {
+ font-family: 'Consolas', 'Deja Vu Sans Mono',
+ 'Bitstream Vera Sans Mono', monospace;
+ font-size: 0.95em;
+}
+
+:not(a.reference) > tt {
+ background-color: #f2f2f2;
+ border-bottom: 1px solid #ddd;
+ color: #333;
+}
+
+tt.descname, tt.descclassname, tt.xref {
+ border: 0;
+}
+
+hr {
+ border: 1px solid #abc;
+ margin: 2em;
+}
+
+p a tt {
+ border: 0;
+ color: #CA7900;
+}
+
+p a tt:hover {
+ color: #2491CF;
+}
+
+a tt {
+ border: none;
+}
+
+pre {
+ font-family: 'Consolas', 'Deja Vu Sans Mono',
+ 'Bitstream Vera Sans Mono', monospace;
+ font-size: 0.95em;
+ line-height: 120%;
+ padding: 0.5em;
+ border: 1px solid #ccc;
+ background-color: #f8f8f8;
+}
+
+pre a {
+ color: inherit;
+ text-decoration: underline;
+}
+
+td.linenos pre {
+ padding: 0.5em 0;
+}
+
+div.quotebar {
+ background-color: #f8f8f8;
+ max-width: 250px;
+ float: right;
+ padding: 2px 7px;
+ border: 1px solid #ccc;
+}
+
+div.topic {
+ background-color: #f8f8f8;
+}
+
+table {
+ border-collapse: collapse;
+ margin: 0 -0.5em 0 -0.5em;
+}
+
+table td, table th {
+ padding: 0.2em 0.5em 0.2em 0.5em;
+}
+
+div.admonition, div.warning {
+ font-size: 0.9em;
+ margin: 1em 0 1em 0;
+ border: 1px solid #86989B;
+ background-color: #f7f7f7;
+ padding: 0;
+}
+
+div.admonition p, div.warning p {
+ margin: 0.5em 1em 0.5em 1em;
+ padding: 0;
+}
+
+div.admonition pre, div.warning pre {
+ margin: 0.4em 1em 0.4em 1em;
+}
+
+div.admonition p.admonition-title,
+div.warning p.admonition-title {
+ margin: 0;
+ padding: 0.1em 0 0.1em 0.5em;
+ color: white;
+ border-bottom: 1px solid #86989B;
+ font-weight: bold;
+ background-color: #AFC1C4;
+}
+
+div.warning {
+ border: 1px solid #940000;
+}
+
+div.warning p.admonition-title {
+ background-color: #CF0000;
+ border-bottom-color: #940000;
+}
+
+div.admonition ul, div.admonition ol,
+div.warning ul, div.warning ol {
+ margin: 0.1em 0.5em 0.5em 3em;
+ padding: 0;
+}
+
+div.versioninfo {
+ margin: 1em 0 0 0;
+ border: 1px solid #ccc;
+ background-color: #DDEAF0;
+ padding: 8px;
+ line-height: 1.3em;
+ font-size: 0.9em;
+}
+
+.viewcode-back {
+ font-family: 'Lucida Grande', 'Lucida Sans Unicode', 'Geneva',
+ 'Verdana', sans-serif;
+}
+
+div.viewcode-block:target {
+ background-color: #f4debf;
+ border-top: 1px solid #ac9;
+ border-bottom: 1px solid #ac9;
+}
Added: www-releases/trunk/8.0.0/docs/_static/llvm.css
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/llvm.css?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/llvm.css (added)
+++ www-releases/trunk/8.0.0/docs/_static/llvm.css Wed Mar 20 02:13:27 2019
@@ -0,0 +1,112 @@
+/*
+ * LLVM documentation style sheet
+ */
+
+/* Common styles */
+.body { color: black; background: white; margin: 0 0 0 0 }
+
+/* No borders on image links */
+a:link img, a:visited img { border-style: none }
+
+address img { float: right; width: 88px; height: 31px; }
+address { clear: right; }
+
+table { text-align: center; border: 2px solid black;
+ border-collapse: collapse; margin-top: 1em; margin-left: 1em;
+ margin-right: 1em; margin-bottom: 1em; }
+tr, td { border: 2px solid gray; padding: 4pt 4pt 2pt 2pt; }
+th { border: 2px solid gray; font-weight: bold; font-size: 105%;
+ background: url("lines.gif");
+ font-family: "Georgia,Palatino,Times,Roman,SanSerif";
+ text-align: center; vertical-align: middle; }
+/*
+ * Documentation
+ */
+/* Common for title and header */
+.doc_title, .doc_section, .doc_subsection, h1, h2, h3 {
+ color: black; background: url("lines.gif");
+ font-family: "Georgia,Palatino,Times,Roman,SanSerif"; font-weight: bold;
+ border-width: 1px;
+ border-style: solid none solid none;
+ text-align: center;
+ vertical-align: middle;
+ padding-left: 8pt;
+ padding-top: 1px;
+ padding-bottom: 2px
+}
+
+h1, .doc_title, .title { text-align: left; font-size: 25pt }
+
+h2, .doc_section { text-align: center; font-size: 22pt;
+ margin: 20pt 0pt 5pt 0pt; }
+
+h3, .doc_subsection { width: 75%;
+ text-align: left; font-size: 12pt;
+ padding: 4pt 4pt 4pt 4pt;
+ margin: 1.5em 0.5em 0.5em 0.5em }
+
+h4, .doc_subsubsection { margin: 2.0em 0.5em 0.5em 0.5em;
+ font-weight: bold; font-style: oblique;
+ border-bottom: 1px solid #999999; font-size: 12pt;
+ width: 75%; }
+
+.doc_author { text-align: left; font-weight: bold; padding-left: 20pt }
+.doc_text { text-align: left; padding-left: 20pt; padding-right: 10pt }
+
+.doc_footer { text-align: left; padding: 0 0 0 0 }
+
+.doc_hilite { color: blue; font-weight: bold; }
+
+.doc_table { text-align: center; width: 90%;
+ padding: 1px 1px 1px 1px; border: 1px; }
+
+.doc_warning { color: red; font-weight: bold }
+
+/* <div class="doc_code"> would use this class, and <div> adds more padding */
+.doc_code, .literal-block
+ { border: solid 1px gray; background: #eeeeee;
+ margin: 0 1em 0 1em;
+ padding: 0 1em 0 1em;
+ display: table;
+ }
+
+blockquote pre {
+ padding: 1em 2em 1em 1em;
+ border: solid 1px gray;
+ background: #eeeeee;
+ margin: 0 1em 0 1em;
+ display: table;
+}
+
+h2+div, h2+p {text-align: left; padding-left: 20pt; padding-right: 10pt;}
+h3+div, h3+p {text-align: left; padding-left: 20pt; padding-right: 10pt;}
+h4+div, h4+p {text-align: left; padding-left: 20pt; padding-right: 10pt;}
+
+/* It is preferable to use <pre class="doc_code"> everywhere instead of the
+ * <div class="doc_code"><pre>...</ptr></div> construct.
+ *
+ * Once all docs use <pre> for code regions, this style can be merged with the
+ * one above, and we can drop the [pre] qualifier.
+ */
+pre.doc_code, .literal-block { padding: 1em 2em 1em 1em }
+
+.doc_notes { background: #fafafa; border: 1px solid #cecece;
+ display: table; padding: 0 1em 0 .1em }
+
+table.layout { text-align: left; border: none; border-collapse: collapse;
+ padding: 4px 4px 4px 4px; }
+tr.layout, td.layout, td.left, td.right
+ { border: none; padding: 4pt 4pt 2pt 2pt; vertical-align: top; }
+td.left { text-align: left }
+td.right { text-align: right }
+th.layout { border: none; font-weight: bold; font-size: 105%;
+ text-align: center; vertical-align: middle; }
+
+/* Left align table cell */
+.td_left { border: 2px solid gray; text-align: left; }
+
+/* ReST-specific */
+.title { margin-top: 0 }
+.topic-title{ display: none }
+div.contents ul { list-style-type: decimal }
+.toc-backref { color: black; text-decoration: none; }
Added: www-releases/trunk/8.0.0/docs/_static/logo.png
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/logo.png?rev=356539&view=auto
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svn:mime-type = application/octet-stream
Added: www-releases/trunk/8.0.0/docs/_static/pygments.css
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/pygments.css?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/pygments.css (added)
+++ www-releases/trunk/8.0.0/docs/_static/pygments.css Wed Mar 20 02:13:27 2019
@@ -0,0 +1,69 @@
+.highlight .hll { background-color: #ffffcc }
+.highlight { background: #f0f0f0; }
+.highlight .c { color: #60a0b0; font-style: italic } /* Comment */
+.highlight .err { border: 1px solid #FF0000 } /* Error */
+.highlight .k { color: #007020; font-weight: bold } /* Keyword */
+.highlight .o { color: #666666 } /* Operator */
+.highlight .ch { color: #60a0b0; font-style: italic } /* Comment.Hashbang */
+.highlight .cm { color: #60a0b0; font-style: italic } /* Comment.Multiline */
+.highlight .cp { color: #007020 } /* Comment.Preproc */
+.highlight .cpf { color: #60a0b0; font-style: italic } /* Comment.PreprocFile */
+.highlight .c1 { color: #60a0b0; font-style: italic } /* Comment.Single */
+.highlight .cs { color: #60a0b0; background-color: #fff0f0 } /* Comment.Special */
+.highlight .gd { color: #A00000 } /* Generic.Deleted */
+.highlight .ge { font-style: italic } /* Generic.Emph */
+.highlight .gr { color: #FF0000 } /* Generic.Error */
+.highlight .gh { color: #000080; font-weight: bold } /* Generic.Heading */
+.highlight .gi { color: #00A000 } /* Generic.Inserted */
+.highlight .go { color: #888888 } /* Generic.Output */
+.highlight .gp { color: #c65d09; font-weight: bold } /* Generic.Prompt */
+.highlight .gs { font-weight: bold } /* Generic.Strong */
+.highlight .gu { color: #800080; font-weight: bold } /* Generic.Subheading */
+.highlight .gt { color: #0044DD } /* Generic.Traceback */
+.highlight .kc { color: #007020; font-weight: bold } /* Keyword.Constant */
+.highlight .kd { color: #007020; font-weight: bold } /* Keyword.Declaration */
+.highlight .kn { color: #007020; font-weight: bold } /* Keyword.Namespace */
+.highlight .kp { color: #007020 } /* Keyword.Pseudo */
+.highlight .kr { color: #007020; font-weight: bold } /* Keyword.Reserved */
+.highlight .kt { color: #902000 } /* Keyword.Type */
+.highlight .m { color: #40a070 } /* Literal.Number */
+.highlight .s { color: #4070a0 } /* Literal.String */
+.highlight .na { color: #4070a0 } /* Name.Attribute */
+.highlight .nb { color: #007020 } /* Name.Builtin */
+.highlight .nc { color: #0e84b5; font-weight: bold } /* Name.Class */
+.highlight .no { color: #60add5 } /* Name.Constant */
+.highlight .nd { color: #555555; font-weight: bold } /* Name.Decorator */
+.highlight .ni { color: #d55537; font-weight: bold } /* Name.Entity */
+.highlight .ne { color: #007020 } /* Name.Exception */
+.highlight .nf { color: #06287e } /* Name.Function */
+.highlight .nl { color: #002070; font-weight: bold } /* Name.Label */
+.highlight .nn { color: #0e84b5; font-weight: bold } /* Name.Namespace */
+.highlight .nt { color: #062873; font-weight: bold } /* Name.Tag */
+.highlight .nv { color: #bb60d5 } /* Name.Variable */
+.highlight .ow { color: #007020; font-weight: bold } /* Operator.Word */
+.highlight .w { color: #bbbbbb } /* Text.Whitespace */
+.highlight .mb { color: #40a070 } /* Literal.Number.Bin */
+.highlight .mf { color: #40a070 } /* Literal.Number.Float */
+.highlight .mh { color: #40a070 } /* Literal.Number.Hex */
+.highlight .mi { color: #40a070 } /* Literal.Number.Integer */
+.highlight .mo { color: #40a070 } /* Literal.Number.Oct */
+.highlight .sa { color: #4070a0 } /* Literal.String.Affix */
+.highlight .sb { color: #4070a0 } /* Literal.String.Backtick */
+.highlight .sc { color: #4070a0 } /* Literal.String.Char */
+.highlight .dl { color: #4070a0 } /* Literal.String.Delimiter */
+.highlight .sd { color: #4070a0; font-style: italic } /* Literal.String.Doc */
+.highlight .s2 { color: #4070a0 } /* Literal.String.Double */
+.highlight .se { color: #4070a0; font-weight: bold } /* Literal.String.Escape */
+.highlight .sh { color: #4070a0 } /* Literal.String.Heredoc */
+.highlight .si { color: #70a0d0; font-style: italic } /* Literal.String.Interpol */
+.highlight .sx { color: #c65d09 } /* Literal.String.Other */
+.highlight .sr { color: #235388 } /* Literal.String.Regex */
+.highlight .s1 { color: #4070a0 } /* Literal.String.Single */
+.highlight .ss { color: #517918 } /* Literal.String.Symbol */
+.highlight .bp { color: #007020 } /* Name.Builtin.Pseudo */
+.highlight .fm { color: #06287e } /* Name.Function.Magic */
+.highlight .vc { color: #bb60d5 } /* Name.Variable.Class */
+.highlight .vg { color: #bb60d5 } /* Name.Variable.Global */
+.highlight .vi { color: #bb60d5 } /* Name.Variable.Instance */
+.highlight .vm { color: #bb60d5 } /* Name.Variable.Magic */
+.highlight .il { color: #40a070 } /* Literal.Number.Integer.Long */
\ No newline at end of file
Added: www-releases/trunk/8.0.0/docs/_static/searchtools.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/searchtools.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/searchtools.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/searchtools.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,761 @@
+/*
+ * searchtools.js_t
+ * ~~~~~~~~~~~~~~~~
+ *
+ * Sphinx JavaScript utilities for the full-text search.
+ *
+ * :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
+ * :license: BSD, see LICENSE for details.
+ *
+ */
+
+
+/* Non-minified version JS is _stemmer.js if file is provided */
+/**
+ * Porter Stemmer
+ */
+var Stemmer = function() {
+
+ var step2list = {
+ ational: 'ate',
+ tional: 'tion',
+ enci: 'ence',
+ anci: 'ance',
+ izer: 'ize',
+ bli: 'ble',
+ alli: 'al',
+ entli: 'ent',
+ eli: 'e',
+ ousli: 'ous',
+ ization: 'ize',
+ ation: 'ate',
+ ator: 'ate',
+ alism: 'al',
+ iveness: 'ive',
+ fulness: 'ful',
+ ousness: 'ous',
+ aliti: 'al',
+ iviti: 'ive',
+ biliti: 'ble',
+ logi: 'log'
+ };
+
+ var step3list = {
+ icate: 'ic',
+ ative: '',
+ alize: 'al',
+ iciti: 'ic',
+ ical: 'ic',
+ ful: '',
+ ness: ''
+ };
+
+ var c = "[^aeiou]"; // consonant
+ var v = "[aeiouy]"; // vowel
+ var C = c + "[^aeiouy]*"; // consonant sequence
+ var V = v + "[aeiou]*"; // vowel sequence
+
+ var mgr0 = "^(" + C + ")?" + V + C; // [C]VC... is m>0
+ var meq1 = "^(" + C + ")?" + V + C + "(" + V + ")?$"; // [C]VC[V] is m=1
+ var mgr1 = "^(" + C + ")?" + V + C + V + C; // [C]VCVC... is m>1
+ var s_v = "^(" + C + ")?" + v; // vowel in stem
+
+ this.stemWord = function (w) {
+ var stem;
+ var suffix;
+ var firstch;
+ var origword = w;
+
+ if (w.length < 3)
+ return w;
+
+ var re;
+ var re2;
+ var re3;
+ var re4;
+
+ firstch = w.substr(0,1);
+ if (firstch == "y")
+ w = firstch.toUpperCase() + w.substr(1);
+
+ // Step 1a
+ re = /^(.+?)(ss|i)es$/;
+ re2 = /^(.+?)([^s])s$/;
+
+ if (re.test(w))
+ w = w.replace(re,"$1$2");
+ else if (re2.test(w))
+ w = w.replace(re2,"$1$2");
+
+ // Step 1b
+ re = /^(.+?)eed$/;
+ re2 = /^(.+?)(ed|ing)$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ re = new RegExp(mgr0);
+ if (re.test(fp[1])) {
+ re = /.$/;
+ w = w.replace(re,"");
+ }
+ }
+ else if (re2.test(w)) {
+ var fp = re2.exec(w);
+ stem = fp[1];
+ re2 = new RegExp(s_v);
+ if (re2.test(stem)) {
+ w = stem;
+ re2 = /(at|bl|iz)$/;
+ re3 = new RegExp("([^aeiouylsz])\\1$");
+ re4 = new RegExp("^" + C + v + "[^aeiouwxy]$");
+ if (re2.test(w))
+ w = w + "e";
+ else if (re3.test(w)) {
+ re = /.$/;
+ w = w.replace(re,"");
+ }
+ else if (re4.test(w))
+ w = w + "e";
+ }
+ }
+
+ // Step 1c
+ re = /^(.+?)y$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ stem = fp[1];
+ re = new RegExp(s_v);
+ if (re.test(stem))
+ w = stem + "i";
+ }
+
+ // Step 2
+ re = /^(.+?)(ational|tional|enci|anci|izer|bli|alli|entli|eli|ousli|ization|ation|ator|alism|iveness|fulness|ousness|aliti|iviti|biliti|logi)$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ stem = fp[1];
+ suffix = fp[2];
+ re = new RegExp(mgr0);
+ if (re.test(stem))
+ w = stem + step2list[suffix];
+ }
+
+ // Step 3
+ re = /^(.+?)(icate|ative|alize|iciti|ical|ful|ness)$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ stem = fp[1];
+ suffix = fp[2];
+ re = new RegExp(mgr0);
+ if (re.test(stem))
+ w = stem + step3list[suffix];
+ }
+
+ // Step 4
+ re = /^(.+?)(al|ance|ence|er|ic|able|ible|ant|ement|ment|ent|ou|ism|ate|iti|ous|ive|ize)$/;
+ re2 = /^(.+?)(s|t)(ion)$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ stem = fp[1];
+ re = new RegExp(mgr1);
+ if (re.test(stem))
+ w = stem;
+ }
+ else if (re2.test(w)) {
+ var fp = re2.exec(w);
+ stem = fp[1] + fp[2];
+ re2 = new RegExp(mgr1);
+ if (re2.test(stem))
+ w = stem;
+ }
+
+ // Step 5
+ re = /^(.+?)e$/;
+ if (re.test(w)) {
+ var fp = re.exec(w);
+ stem = fp[1];
+ re = new RegExp(mgr1);
+ re2 = new RegExp(meq1);
+ re3 = new RegExp("^" + C + v + "[^aeiouwxy]$");
+ if (re.test(stem) || (re2.test(stem) && !(re3.test(stem))))
+ w = stem;
+ }
+ re = /ll$/;
+ re2 = new RegExp(mgr1);
+ if (re.test(w) && re2.test(w)) {
+ re = /.$/;
+ w = w.replace(re,"");
+ }
+
+ // and turn initial Y back to y
+ if (firstch == "y")
+ w = firstch.toLowerCase() + w.substr(1);
+ return w;
+ }
+}
+
+
+
+/**
+ * Simple result scoring code.
+ */
+var Scorer = {
+ // Implement the following function to further tweak the score for each result
+ // The function takes a result array [filename, title, anchor, descr, score]
+ // and returns the new score.
+ /*
+ score: function(result) {
+ return result[4];
+ },
+ */
+
+ // query matches the full name of an object
+ objNameMatch: 11,
+ // or matches in the last dotted part of the object name
+ objPartialMatch: 6,
+ // Additive scores depending on the priority of the object
+ objPrio: {0: 15, // used to be importantResults
+ 1: 5, // used to be objectResults
+ 2: -5}, // used to be unimportantResults
+ // Used when the priority is not in the mapping.
+ objPrioDefault: 0,
+
+ // query found in title
+ title: 15,
+ // query found in terms
+ term: 5
+};
+
+
+
+
+
+var splitChars = (function() {
+ var result = {};
+ var singles = [96, 180, 187, 191, 215, 247, 749, 885, 903, 907, 909, 930, 1014, 1648,
+ 1748, 1809, 2416, 2473, 2481, 2526, 2601, 2609, 2612, 2615, 2653, 2702,
+ 2706, 2729, 2737, 2740, 2857, 2865, 2868, 2910, 2928, 2948, 2961, 2971,
+ 2973, 3085, 3089, 3113, 3124, 3213, 3217, 3241, 3252, 3295, 3341, 3345,
+ 3369, 3506, 3516, 3633, 3715, 3721, 3736, 3744, 3748, 3750, 3756, 3761,
+ 3781, 3912, 4239, 4347, 4681, 4695, 4697, 4745, 4785, 4799, 4801, 4823,
+ 4881, 5760, 5901, 5997, 6313, 7405, 8024, 8026, 8028, 8030, 8117, 8125,
+ 8133, 8181, 8468, 8485, 8487, 8489, 8494, 8527, 11311, 11359, 11687, 11695,
+ 11703, 11711, 11719, 11727, 11735, 12448, 12539, 43010, 43014, 43019, 43587,
+ 43696, 43713, 64286, 64297, 64311, 64317, 64319, 64322, 64325, 65141];
+ var i, j, start, end;
+ for (i = 0; i < singles.length; i++) {
+ result[singles[i]] = true;
+ }
+ var ranges = [[0, 47], [58, 64], [91, 94], [123, 169], [171, 177], [182, 184], [706, 709],
+ [722, 735], [741, 747], [751, 879], [888, 889], [894, 901], [1154, 1161],
+ [1318, 1328], [1367, 1368], [1370, 1376], [1416, 1487], [1515, 1519], [1523, 1568],
+ [1611, 1631], [1642, 1645], [1750, 1764], [1767, 1773], [1789, 1790], [1792, 1807],
+ [1840, 1868], [1958, 1968], [1970, 1983], [2027, 2035], [2038, 2041], [2043, 2047],
+ [2070, 2073], [2075, 2083], [2085, 2087], [2089, 2307], [2362, 2364], [2366, 2383],
+ [2385, 2391], [2402, 2405], [2419, 2424], [2432, 2436], [2445, 2446], [2449, 2450],
+ [2483, 2485], [2490, 2492], [2494, 2509], [2511, 2523], [2530, 2533], [2546, 2547],
+ [2554, 2564], [2571, 2574], [2577, 2578], [2618, 2648], [2655, 2661], [2672, 2673],
+ [2677, 2692], [2746, 2748], [2750, 2767], [2769, 2783], [2786, 2789], [2800, 2820],
+ [2829, 2830], [2833, 2834], [2874, 2876], [2878, 2907], [2914, 2917], [2930, 2946],
+ [2955, 2957], [2966, 2968], [2976, 2978], [2981, 2983], [2987, 2989], [3002, 3023],
+ [3025, 3045], [3059, 3076], [3130, 3132], [3134, 3159], [3162, 3167], [3170, 3173],
+ [3184, 3191], [3199, 3204], [3258, 3260], [3262, 3293], [3298, 3301], [3312, 3332],
+ [3386, 3388], [3390, 3423], [3426, 3429], [3446, 3449], [3456, 3460], [3479, 3481],
+ [3518, 3519], [3527, 3584], [3636, 3647], [3655, 3663], [3674, 3712], [3717, 3718],
+ [3723, 3724], [3726, 3731], [3752, 3753], [3764, 3772], [3774, 3775], [3783, 3791],
+ [3802, 3803], [3806, 3839], [3841, 3871], [3892, 3903], [3949, 3975], [3980, 4095],
+ [4139, 4158], [4170, 4175], [4182, 4185], [4190, 4192], [4194, 4196], [4199, 4205],
+ [4209, 4212], [4226, 4237], [4250, 4255], [4294, 4303], [4349, 4351], [4686, 4687],
+ [4702, 4703], [4750, 4751], [4790, 4791], [4806, 4807], [4886, 4887], [4955, 4968],
+ [4989, 4991], [5008, 5023], [5109, 5120], [5741, 5742], [5787, 5791], [5867, 5869],
+ [5873, 5887], [5906, 5919], [5938, 5951], [5970, 5983], [6001, 6015], [6068, 6102],
+ [6104, 6107], [6109, 6111], [6122, 6127], [6138, 6159], [6170, 6175], [6264, 6271],
+ [6315, 6319], [6390, 6399], [6429, 6469], [6510, 6511], [6517, 6527], [6572, 6592],
+ [6600, 6607], [6619, 6655], [6679, 6687], [6741, 6783], [6794, 6799], [6810, 6822],
+ [6824, 6916], [6964, 6980], [6988, 6991], [7002, 7042], [7073, 7085], [7098, 7167],
+ [7204, 7231], [7242, 7244], [7294, 7400], [7410, 7423], [7616, 7679], [7958, 7959],
+ [7966, 7967], [8006, 8007], [8014, 8015], [8062, 8063], [8127, 8129], [8141, 8143],
+ [8148, 8149], [8156, 8159], [8173, 8177], [8189, 8303], [8306, 8307], [8314, 8318],
+ [8330, 8335], [8341, 8449], [8451, 8454], [8456, 8457], [8470, 8472], [8478, 8483],
+ [8506, 8507], [8512, 8516], [8522, 8525], [8586, 9311], [9372, 9449], [9472, 10101],
+ [10132, 11263], [11493, 11498], [11503, 11516], [11518, 11519], [11558, 11567],
+ [11622, 11630], [11632, 11647], [11671, 11679], [11743, 11822], [11824, 12292],
+ [12296, 12320], [12330, 12336], [12342, 12343], [12349, 12352], [12439, 12444],
+ [12544, 12548], [12590, 12592], [12687, 12689], [12694, 12703], [12728, 12783],
+ [12800, 12831], [12842, 12880], [12896, 12927], [12938, 12976], [12992, 13311],
+ [19894, 19967], [40908, 40959], [42125, 42191], [42238, 42239], [42509, 42511],
+ [42540, 42559], [42592, 42593], [42607, 42622], [42648, 42655], [42736, 42774],
+ [42784, 42785], [42889, 42890], [42893, 43002], [43043, 43055], [43062, 43071],
+ [43124, 43137], [43188, 43215], [43226, 43249], [43256, 43258], [43260, 43263],
+ [43302, 43311], [43335, 43359], [43389, 43395], [43443, 43470], [43482, 43519],
+ [43561, 43583], [43596, 43599], [43610, 43615], [43639, 43641], [43643, 43647],
+ [43698, 43700], [43703, 43704], [43710, 43711], [43715, 43738], [43742, 43967],
+ [44003, 44015], [44026, 44031], [55204, 55215], [55239, 55242], [55292, 55295],
+ [57344, 63743], [64046, 64047], [64110, 64111], [64218, 64255], [64263, 64274],
+ [64280, 64284], [64434, 64466], [64830, 64847], [64912, 64913], [64968, 65007],
+ [65020, 65135], [65277, 65295], [65306, 65312], [65339, 65344], [65371, 65381],
+ [65471, 65473], [65480, 65481], [65488, 65489], [65496, 65497]];
+ for (i = 0; i < ranges.length; i++) {
+ start = ranges[i][0];
+ end = ranges[i][1];
+ for (j = start; j <= end; j++) {
+ result[j] = true;
+ }
+ }
+ return result;
+})();
+
+function splitQuery(query) {
+ var result = [];
+ var start = -1;
+ for (var i = 0; i < query.length; i++) {
+ if (splitChars[query.charCodeAt(i)]) {
+ if (start !== -1) {
+ result.push(query.slice(start, i));
+ start = -1;
+ }
+ } else if (start === -1) {
+ start = i;
+ }
+ }
+ if (start !== -1) {
+ result.push(query.slice(start));
+ }
+ return result;
+}
+
+
+
+
+/**
+ * Search Module
+ */
+var Search = {
+
+ _index : null,
+ _queued_query : null,
+ _pulse_status : -1,
+
+ init : function() {
+ var params = $.getQueryParameters();
+ if (params.q) {
+ var query = params.q[0];
+ $('input[name="q"]')[0].value = query;
+ this.performSearch(query);
+ }
+ },
+
+ loadIndex : function(url) {
+ $.ajax({type: "GET", url: url, data: null,
+ dataType: "script", cache: true,
+ complete: function(jqxhr, textstatus) {
+ if (textstatus != "success") {
+ document.getElementById("searchindexloader").src = url;
+ }
+ }});
+ },
+
+ setIndex : function(index) {
+ var q;
+ this._index = index;
+ if ((q = this._queued_query) !== null) {
+ this._queued_query = null;
+ Search.query(q);
+ }
+ },
+
+ hasIndex : function() {
+ return this._index !== null;
+ },
+
+ deferQuery : function(query) {
+ this._queued_query = query;
+ },
+
+ stopPulse : function() {
+ this._pulse_status = 0;
+ },
+
+ startPulse : function() {
+ if (this._pulse_status >= 0)
+ return;
+ function pulse() {
+ var i;
+ Search._pulse_status = (Search._pulse_status + 1) % 4;
+ var dotString = '';
+ for (i = 0; i < Search._pulse_status; i++)
+ dotString += '.';
+ Search.dots.text(dotString);
+ if (Search._pulse_status > -1)
+ window.setTimeout(pulse, 500);
+ }
+ pulse();
+ },
+
+ /**
+ * perform a search for something (or wait until index is loaded)
+ */
+ performSearch : function(query) {
+ // create the required interface elements
+ this.out = $('#search-results');
+ this.title = $('<h2>' + _('Searching') + '</h2>').appendTo(this.out);
+ this.dots = $('<span></span>').appendTo(this.title);
+ this.status = $('<p style="display: none"></p>').appendTo(this.out);
+ this.output = $('<ul class="search"/>').appendTo(this.out);
+
+ $('#search-progress').text(_('Preparing search...'));
+ this.startPulse();
+
+ // index already loaded, the browser was quick!
+ if (this.hasIndex())
+ this.query(query);
+ else
+ this.deferQuery(query);
+ },
+
+ /**
+ * execute search (requires search index to be loaded)
+ */
+ query : function(query) {
+ var i;
+ var stopwords = ["a","and","are","as","at","be","but","by","for","if","in","into","is","it","near","no","not","of","on","or","such","that","the","their","then","there","these","they","this","to","was","will","with"];
+
+ // stem the searchterms and add them to the correct list
+ var stemmer = new Stemmer();
+ var searchterms = [];
+ var excluded = [];
+ var hlterms = [];
+ var tmp = splitQuery(query);
+ var objectterms = [];
+ for (i = 0; i < tmp.length; i++) {
+ if (tmp[i] !== "") {
+ objectterms.push(tmp[i].toLowerCase());
+ }
+
+ if ($u.indexOf(stopwords, tmp[i].toLowerCase()) != -1 || tmp[i].match(/^\d+$/) ||
+ tmp[i] === "") {
+ // skip this "word"
+ continue;
+ }
+ // stem the word
+ var word = stemmer.stemWord(tmp[i].toLowerCase());
+ // prevent stemmer from cutting word smaller than two chars
+ if(word.length < 3 && tmp[i].length >= 3) {
+ word = tmp[i];
+ }
+ var toAppend;
+ // select the correct list
+ if (word[0] == '-') {
+ toAppend = excluded;
+ word = word.substr(1);
+ }
+ else {
+ toAppend = searchterms;
+ hlterms.push(tmp[i].toLowerCase());
+ }
+ // only add if not already in the list
+ if (!$u.contains(toAppend, word))
+ toAppend.push(word);
+ }
+ var highlightstring = '?highlight=' + $.urlencode(hlterms.join(" "));
+
+ // console.debug('SEARCH: searching for:');
+ // console.info('required: ', searchterms);
+ // console.info('excluded: ', excluded);
+
+ // prepare search
+ var terms = this._index.terms;
+ var titleterms = this._index.titleterms;
+
+ // array of [filename, title, anchor, descr, score]
+ var results = [];
+ $('#search-progress').empty();
+
+ // lookup as object
+ for (i = 0; i < objectterms.length; i++) {
+ var others = [].concat(objectterms.slice(0, i),
+ objectterms.slice(i+1, objectterms.length));
+ results = results.concat(this.performObjectSearch(objectterms[i], others));
+ }
+
+ // lookup as search terms in fulltext
+ results = results.concat(this.performTermsSearch(searchterms, excluded, terms, titleterms));
+
+ // let the scorer override scores with a custom scoring function
+ if (Scorer.score) {
+ for (i = 0; i < results.length; i++)
+ results[i][4] = Scorer.score(results[i]);
+ }
+
+ // now sort the results by score (in opposite order of appearance, since the
+ // display function below uses pop() to retrieve items) and then
+ // alphabetically
+ results.sort(function(a, b) {
+ var left = a[4];
+ var right = b[4];
+ if (left > right) {
+ return 1;
+ } else if (left < right) {
+ return -1;
+ } else {
+ // same score: sort alphabetically
+ left = a[1].toLowerCase();
+ right = b[1].toLowerCase();
+ return (left > right) ? -1 : ((left < right) ? 1 : 0);
+ }
+ });
+
+ // for debugging
+ //Search.lastresults = results.slice(); // a copy
+ //console.info('search results:', Search.lastresults);
+
+ // print the results
+ var resultCount = results.length;
+ function displayNextItem() {
+ // results left, load the summary and display it
+ if (results.length) {
+ var item = results.pop();
+ var listItem = $('<li style="display:none"></li>');
+ if (DOCUMENTATION_OPTIONS.FILE_SUFFIX === '') {
+ // dirhtml builder
+ var dirname = item[0] + '/';
+ if (dirname.match(/\/index\/$/)) {
+ dirname = dirname.substring(0, dirname.length-6);
+ } else if (dirname == 'index/') {
+ dirname = '';
+ }
+ listItem.append($('<a/>').attr('href',
+ DOCUMENTATION_OPTIONS.URL_ROOT + dirname +
+ highlightstring + item[2]).html(item[1]));
+ } else {
+ // normal html builders
+ listItem.append($('<a/>').attr('href',
+ item[0] + DOCUMENTATION_OPTIONS.FILE_SUFFIX +
+ highlightstring + item[2]).html(item[1]));
+ }
+ if (item[3]) {
+ listItem.append($('<span> (' + item[3] + ')</span>'));
+ Search.output.append(listItem);
+ listItem.slideDown(5, function() {
+ displayNextItem();
+ });
+ } else if (DOCUMENTATION_OPTIONS.HAS_SOURCE) {
+ var suffix = DOCUMENTATION_OPTIONS.SOURCELINK_SUFFIX;
+ if (suffix === undefined) {
+ suffix = '.txt';
+ }
+ $.ajax({url: DOCUMENTATION_OPTIONS.URL_ROOT + '_sources/' + item[5] + (item[5].slice(-suffix.length) === suffix ? '' : suffix),
+ dataType: "text",
+ complete: function(jqxhr, textstatus) {
+ var data = jqxhr.responseText;
+ if (data !== '' && data !== undefined) {
+ listItem.append(Search.makeSearchSummary(data, searchterms, hlterms));
+ }
+ Search.output.append(listItem);
+ listItem.slideDown(5, function() {
+ displayNextItem();
+ });
+ }});
+ } else {
+ // no source available, just display title
+ Search.output.append(listItem);
+ listItem.slideDown(5, function() {
+ displayNextItem();
+ });
+ }
+ }
+ // search finished, update title and status message
+ else {
+ Search.stopPulse();
+ Search.title.text(_('Search Results'));
+ if (!resultCount)
+ Search.status.text(_('Your search did not match any documents. Please make sure that all words are spelled correctly and that you\'ve selected enough categories.'));
+ else
+ Search.status.text(_('Search finished, found %s page(s) matching the search query.').replace('%s', resultCount));
+ Search.status.fadeIn(500);
+ }
+ }
+ displayNextItem();
+ },
+
+ /**
+ * search for object names
+ */
+ performObjectSearch : function(object, otherterms) {
+ var filenames = this._index.filenames;
+ var docnames = this._index.docnames;
+ var objects = this._index.objects;
+ var objnames = this._index.objnames;
+ var titles = this._index.titles;
+
+ var i;
+ var results = [];
+
+ for (var prefix in objects) {
+ for (var name in objects[prefix]) {
+ var fullname = (prefix ? prefix + '.' : '') + name;
+ if (fullname.toLowerCase().indexOf(object) > -1) {
+ var score = 0;
+ var parts = fullname.split('.');
+ // check for different match types: exact matches of full name or
+ // "last name" (i.e. last dotted part)
+ if (fullname == object || parts[parts.length - 1] == object) {
+ score += Scorer.objNameMatch;
+ // matches in last name
+ } else if (parts[parts.length - 1].indexOf(object) > -1) {
+ score += Scorer.objPartialMatch;
+ }
+ var match = objects[prefix][name];
+ var objname = objnames[match[1]][2];
+ var title = titles[match[0]];
+ // If more than one term searched for, we require other words to be
+ // found in the name/title/description
+ if (otherterms.length > 0) {
+ var haystack = (prefix + ' ' + name + ' ' +
+ objname + ' ' + title).toLowerCase();
+ var allfound = true;
+ for (i = 0; i < otherterms.length; i++) {
+ if (haystack.indexOf(otherterms[i]) == -1) {
+ allfound = false;
+ break;
+ }
+ }
+ if (!allfound) {
+ continue;
+ }
+ }
+ var descr = objname + _(', in ') + title;
+
+ var anchor = match[3];
+ if (anchor === '')
+ anchor = fullname;
+ else if (anchor == '-')
+ anchor = objnames[match[1]][1] + '-' + fullname;
+ // add custom score for some objects according to scorer
+ if (Scorer.objPrio.hasOwnProperty(match[2])) {
+ score += Scorer.objPrio[match[2]];
+ } else {
+ score += Scorer.objPrioDefault;
+ }
+ results.push([docnames[match[0]], fullname, '#'+anchor, descr, score, filenames[match[0]]]);
+ }
+ }
+ }
+
+ return results;
+ },
+
+ /**
+ * search for full-text terms in the index
+ */
+ performTermsSearch : function(searchterms, excluded, terms, titleterms) {
+ var docnames = this._index.docnames;
+ var filenames = this._index.filenames;
+ var titles = this._index.titles;
+
+ var i, j, file;
+ var fileMap = {};
+ var scoreMap = {};
+ var results = [];
+
+ // perform the search on the required terms
+ for (i = 0; i < searchterms.length; i++) {
+ var word = searchterms[i];
+ var files = [];
+ var _o = [
+ {files: terms[word], score: Scorer.term},
+ {files: titleterms[word], score: Scorer.title}
+ ];
+
+ // no match but word was a required one
+ if ($u.every(_o, function(o){return o.files === undefined;})) {
+ break;
+ }
+ // found search word in contents
+ $u.each(_o, function(o) {
+ var _files = o.files;
+ if (_files === undefined)
+ return
+
+ if (_files.length === undefined)
+ _files = [_files];
+ files = files.concat(_files);
+
+ // set score for the word in each file to Scorer.term
+ for (j = 0; j < _files.length; j++) {
+ file = _files[j];
+ if (!(file in scoreMap))
+ scoreMap[file] = {}
+ scoreMap[file][word] = o.score;
+ }
+ });
+
+ // create the mapping
+ for (j = 0; j < files.length; j++) {
+ file = files[j];
+ if (file in fileMap)
+ fileMap[file].push(word);
+ else
+ fileMap[file] = [word];
+ }
+ }
+
+ // now check if the files don't contain excluded terms
+ for (file in fileMap) {
+ var valid = true;
+
+ // check if all requirements are matched
+ if (fileMap[file].length != searchterms.length)
+ continue;
+
+ // ensure that none of the excluded terms is in the search result
+ for (i = 0; i < excluded.length; i++) {
+ if (terms[excluded[i]] == file ||
+ titleterms[excluded[i]] == file ||
+ $u.contains(terms[excluded[i]] || [], file) ||
+ $u.contains(titleterms[excluded[i]] || [], file)) {
+ valid = false;
+ break;
+ }
+ }
+
+ // if we have still a valid result we can add it to the result list
+ if (valid) {
+ // select one (max) score for the file.
+ // for better ranking, we should calculate ranking by using words statistics like basic tf-idf...
+ var score = $u.max($u.map(fileMap[file], function(w){return scoreMap[file][w]}));
+ results.push([docnames[file], titles[file], '', null, score, filenames[file]]);
+ }
+ }
+ return results;
+ },
+
+ /**
+ * helper function to return a node containing the
+ * search summary for a given text. keywords is a list
+ * of stemmed words, hlwords is the list of normal, unstemmed
+ * words. the first one is used to find the occurrence, the
+ * latter for highlighting it.
+ */
+ makeSearchSummary : function(text, keywords, hlwords) {
+ var textLower = text.toLowerCase();
+ var start = 0;
+ $.each(keywords, function() {
+ var i = textLower.indexOf(this.toLowerCase());
+ if (i > -1)
+ start = i;
+ });
+ start = Math.max(start - 120, 0);
+ var excerpt = ((start > 0) ? '...' : '') +
+ $.trim(text.substr(start, 240)) +
+ ((start + 240 - text.length) ? '...' : '');
+ var rv = $('<div class="context"></div>').text(excerpt);
+ $.each(hlwords, function() {
+ rv = rv.highlightText(this, 'highlighted');
+ });
+ return rv;
+ }
+};
+
+$(document).ready(function() {
+ Search.init();
+});
\ No newline at end of file
Added: www-releases/trunk/8.0.0/docs/_static/underscore.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/underscore.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/underscore.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/underscore.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,1548 @@
+// Underscore.js 1.8.3
+// http://underscorejs.org
+// (c) 2009-2015 Jeremy Ashkenas, DocumentCloud and Investigative Reporters & Editors
+// Underscore may be freely distributed under the MIT license.
+
+(function() {
+
+ // Baseline setup
+ // --------------
+
+ // Establish the root object, `window` in the browser, or `exports` on the server.
+ var root = this;
+
+ // Save the previous value of the `_` variable.
+ var previousUnderscore = root._;
+
+ // Save bytes in the minified (but not gzipped) version:
+ var ArrayProto = Array.prototype, ObjProto = Object.prototype, FuncProto = Function.prototype;
+
+ // Create quick reference variables for speed access to core prototypes.
+ var
+ push = ArrayProto.push,
+ slice = ArrayProto.slice,
+ toString = ObjProto.toString,
+ hasOwnProperty = ObjProto.hasOwnProperty;
+
+ // All **ECMAScript 5** native function implementations that we hope to use
+ // are declared here.
+ var
+ nativeIsArray = Array.isArray,
+ nativeKeys = Object.keys,
+ nativeBind = FuncProto.bind,
+ nativeCreate = Object.create;
+
+ // Naked function reference for surrogate-prototype-swapping.
+ var Ctor = function(){};
+
+ // Create a safe reference to the Underscore object for use below.
+ var _ = function(obj) {
+ if (obj instanceof _) return obj;
+ if (!(this instanceof _)) return new _(obj);
+ this._wrapped = obj;
+ };
+
+ // Export the Underscore object for **Node.js**, with
+ // backwards-compatibility for the old `require()` API. If we're in
+ // the browser, add `_` as a global object.
+ if (typeof exports !== 'undefined') {
+ if (typeof module !== 'undefined' && module.exports) {
+ exports = module.exports = _;
+ }
+ exports._ = _;
+ } else {
+ root._ = _;
+ }
+
+ // Current version.
+ _.VERSION = '1.8.3';
+
+ // Internal function that returns an efficient (for current engines) version
+ // of the passed-in callback, to be repeatedly applied in other Underscore
+ // functions.
+ var optimizeCb = function(func, context, argCount) {
+ if (context === void 0) return func;
+ switch (argCount == null ? 3 : argCount) {
+ case 1: return function(value) {
+ return func.call(context, value);
+ };
+ case 2: return function(value, other) {
+ return func.call(context, value, other);
+ };
+ case 3: return function(value, index, collection) {
+ return func.call(context, value, index, collection);
+ };
+ case 4: return function(accumulator, value, index, collection) {
+ return func.call(context, accumulator, value, index, collection);
+ };
+ }
+ return function() {
+ return func.apply(context, arguments);
+ };
+ };
+
+ // A mostly-internal function to generate callbacks that can be applied
+ // to each element in a collection, returning the desired result — either
+ // identity, an arbitrary callback, a property matcher, or a property accessor.
+ var cb = function(value, context, argCount) {
+ if (value == null) return _.identity;
+ if (_.isFunction(value)) return optimizeCb(value, context, argCount);
+ if (_.isObject(value)) return _.matcher(value);
+ return _.property(value);
+ };
+ _.iteratee = function(value, context) {
+ return cb(value, context, Infinity);
+ };
+
+ // An internal function for creating assigner functions.
+ var createAssigner = function(keysFunc, undefinedOnly) {
+ return function(obj) {
+ var length = arguments.length;
+ if (length < 2 || obj == null) return obj;
+ for (var index = 1; index < length; index++) {
+ var source = arguments[index],
+ keys = keysFunc(source),
+ l = keys.length;
+ for (var i = 0; i < l; i++) {
+ var key = keys[i];
+ if (!undefinedOnly || obj[key] === void 0) obj[key] = source[key];
+ }
+ }
+ return obj;
+ };
+ };
+
+ // An internal function for creating a new object that inherits from another.
+ var baseCreate = function(prototype) {
+ if (!_.isObject(prototype)) return {};
+ if (nativeCreate) return nativeCreate(prototype);
+ Ctor.prototype = prototype;
+ var result = new Ctor;
+ Ctor.prototype = null;
+ return result;
+ };
+
+ var property = function(key) {
+ return function(obj) {
+ return obj == null ? void 0 : obj[key];
+ };
+ };
+
+ // Helper for collection methods to determine whether a collection
+ // should be iterated as an array or as an object
+ // Related: http://people.mozilla.org/~jorendorff/es6-draft.html#sec-tolength
+ // Avoids a very nasty iOS 8 JIT bug on ARM-64. #2094
+ var MAX_ARRAY_INDEX = Math.pow(2, 53) - 1;
+ var getLength = property('length');
+ var isArrayLike = function(collection) {
+ var length = getLength(collection);
+ return typeof length == 'number' && length >= 0 && length <= MAX_ARRAY_INDEX;
+ };
+
+ // Collection Functions
+ // --------------------
+
+ // The cornerstone, an `each` implementation, aka `forEach`.
+ // Handles raw objects in addition to array-likes. Treats all
+ // sparse array-likes as if they were dense.
+ _.each = _.forEach = function(obj, iteratee, context) {
+ iteratee = optimizeCb(iteratee, context);
+ var i, length;
+ if (isArrayLike(obj)) {
+ for (i = 0, length = obj.length; i < length; i++) {
+ iteratee(obj[i], i, obj);
+ }
+ } else {
+ var keys = _.keys(obj);
+ for (i = 0, length = keys.length; i < length; i++) {
+ iteratee(obj[keys[i]], keys[i], obj);
+ }
+ }
+ return obj;
+ };
+
+ // Return the results of applying the iteratee to each element.
+ _.map = _.collect = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ results = Array(length);
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ results[index] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
+ };
+
+ // Create a reducing function iterating left or right.
+ function createReduce(dir) {
+ // Optimized iterator function as using arguments.length
+ // in the main function will deoptimize the, see #1991.
+ function iterator(obj, iteratee, memo, keys, index, length) {
+ for (; index >= 0 && index < length; index += dir) {
+ var currentKey = keys ? keys[index] : index;
+ memo = iteratee(memo, obj[currentKey], currentKey, obj);
+ }
+ return memo;
+ }
+
+ return function(obj, iteratee, memo, context) {
+ iteratee = optimizeCb(iteratee, context, 4);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length,
+ index = dir > 0 ? 0 : length - 1;
+ // Determine the initial value if none is provided.
+ if (arguments.length < 3) {
+ memo = obj[keys ? keys[index] : index];
+ index += dir;
+ }
+ return iterator(obj, iteratee, memo, keys, index, length);
+ };
+ }
+
+ // **Reduce** builds up a single result from a list of values, aka `inject`,
+ // or `foldl`.
+ _.reduce = _.foldl = _.inject = createReduce(1);
+
+ // The right-associative version of reduce, also known as `foldr`.
+ _.reduceRight = _.foldr = createReduce(-1);
+
+ // Return the first value which passes a truth test. Aliased as `detect`.
+ _.find = _.detect = function(obj, predicate, context) {
+ var key;
+ if (isArrayLike(obj)) {
+ key = _.findIndex(obj, predicate, context);
+ } else {
+ key = _.findKey(obj, predicate, context);
+ }
+ if (key !== void 0 && key !== -1) return obj[key];
+ };
+
+ // Return all the elements that pass a truth test.
+ // Aliased as `select`.
+ _.filter = _.select = function(obj, predicate, context) {
+ var results = [];
+ predicate = cb(predicate, context);
+ _.each(obj, function(value, index, list) {
+ if (predicate(value, index, list)) results.push(value);
+ });
+ return results;
+ };
+
+ // Return all the elements for which a truth test fails.
+ _.reject = function(obj, predicate, context) {
+ return _.filter(obj, _.negate(cb(predicate)), context);
+ };
+
+ // Determine whether all of the elements match a truth test.
+ // Aliased as `all`.
+ _.every = _.all = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (!predicate(obj[currentKey], currentKey, obj)) return false;
+ }
+ return true;
+ };
+
+ // Determine if at least one element in the object matches a truth test.
+ // Aliased as `any`.
+ _.some = _.any = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = !isArrayLike(obj) && _.keys(obj),
+ length = (keys || obj).length;
+ for (var index = 0; index < length; index++) {
+ var currentKey = keys ? keys[index] : index;
+ if (predicate(obj[currentKey], currentKey, obj)) return true;
+ }
+ return false;
+ };
+
+ // Determine if the array or object contains a given item (using `===`).
+ // Aliased as `includes` and `include`.
+ _.contains = _.includes = _.include = function(obj, item, fromIndex, guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ if (typeof fromIndex != 'number' || guard) fromIndex = 0;
+ return _.indexOf(obj, item, fromIndex) >= 0;
+ };
+
+ // Invoke a method (with arguments) on every item in a collection.
+ _.invoke = function(obj, method) {
+ var args = slice.call(arguments, 2);
+ var isFunc = _.isFunction(method);
+ return _.map(obj, function(value) {
+ var func = isFunc ? method : value[method];
+ return func == null ? func : func.apply(value, args);
+ });
+ };
+
+ // Convenience version of a common use case of `map`: fetching a property.
+ _.pluck = function(obj, key) {
+ return _.map(obj, _.property(key));
+ };
+
+ // Convenience version of a common use case of `filter`: selecting only objects
+ // containing specific `key:value` pairs.
+ _.where = function(obj, attrs) {
+ return _.filter(obj, _.matcher(attrs));
+ };
+
+ // Convenience version of a common use case of `find`: getting the first object
+ // containing specific `key:value` pairs.
+ _.findWhere = function(obj, attrs) {
+ return _.find(obj, _.matcher(attrs));
+ };
+
+ // Return the maximum element (or element-based computation).
+ _.max = function(obj, iteratee, context) {
+ var result = -Infinity, lastComputed = -Infinity,
+ value, computed;
+ if (iteratee == null && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value > result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index, list) {
+ computed = iteratee(value, index, list);
+ if (computed > lastComputed || computed === -Infinity && result === -Infinity) {
+ result = value;
+ lastComputed = computed;
+ }
+ });
+ }
+ return result;
+ };
+
+ // Return the minimum element (or element-based computation).
+ _.min = function(obj, iteratee, context) {
+ var result = Infinity, lastComputed = Infinity,
+ value, computed;
+ if (iteratee == null && obj != null) {
+ obj = isArrayLike(obj) ? obj : _.values(obj);
+ for (var i = 0, length = obj.length; i < length; i++) {
+ value = obj[i];
+ if (value < result) {
+ result = value;
+ }
+ }
+ } else {
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index, list) {
+ computed = iteratee(value, index, list);
+ if (computed < lastComputed || computed === Infinity && result === Infinity) {
+ result = value;
+ lastComputed = computed;
+ }
+ });
+ }
+ return result;
+ };
+
+ // Shuffle a collection, using the modern version of the
+ // [Fisher-Yates shuffle](http://en.wikipedia.org/wiki/Fisher–Yates_shuffle).
+ _.shuffle = function(obj) {
+ var set = isArrayLike(obj) ? obj : _.values(obj);
+ var length = set.length;
+ var shuffled = Array(length);
+ for (var index = 0, rand; index < length; index++) {
+ rand = _.random(0, index);
+ if (rand !== index) shuffled[index] = shuffled[rand];
+ shuffled[rand] = set[index];
+ }
+ return shuffled;
+ };
+
+ // Sample **n** random values from a collection.
+ // If **n** is not specified, returns a single random element.
+ // The internal `guard` argument allows it to work with `map`.
+ _.sample = function(obj, n, guard) {
+ if (n == null || guard) {
+ if (!isArrayLike(obj)) obj = _.values(obj);
+ return obj[_.random(obj.length - 1)];
+ }
+ return _.shuffle(obj).slice(0, Math.max(0, n));
+ };
+
+ // Sort the object's values by a criterion produced by an iteratee.
+ _.sortBy = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ return _.pluck(_.map(obj, function(value, index, list) {
+ return {
+ value: value,
+ index: index,
+ criteria: iteratee(value, index, list)
+ };
+ }).sort(function(left, right) {
+ var a = left.criteria;
+ var b = right.criteria;
+ if (a !== b) {
+ if (a > b || a === void 0) return 1;
+ if (a < b || b === void 0) return -1;
+ }
+ return left.index - right.index;
+ }), 'value');
+ };
+
+ // An internal function used for aggregate "group by" operations.
+ var group = function(behavior) {
+ return function(obj, iteratee, context) {
+ var result = {};
+ iteratee = cb(iteratee, context);
+ _.each(obj, function(value, index) {
+ var key = iteratee(value, index, obj);
+ behavior(result, value, key);
+ });
+ return result;
+ };
+ };
+
+ // Groups the object's values by a criterion. Pass either a string attribute
+ // to group by, or a function that returns the criterion.
+ _.groupBy = group(function(result, value, key) {
+ if (_.has(result, key)) result[key].push(value); else result[key] = [value];
+ });
+
+ // Indexes the object's values by a criterion, similar to `groupBy`, but for
+ // when you know that your index values will be unique.
+ _.indexBy = group(function(result, value, key) {
+ result[key] = value;
+ });
+
+ // Counts instances of an object that group by a certain criterion. Pass
+ // either a string attribute to count by, or a function that returns the
+ // criterion.
+ _.countBy = group(function(result, value, key) {
+ if (_.has(result, key)) result[key]++; else result[key] = 1;
+ });
+
+ // Safely create a real, live array from anything iterable.
+ _.toArray = function(obj) {
+ if (!obj) return [];
+ if (_.isArray(obj)) return slice.call(obj);
+ if (isArrayLike(obj)) return _.map(obj, _.identity);
+ return _.values(obj);
+ };
+
+ // Return the number of elements in an object.
+ _.size = function(obj) {
+ if (obj == null) return 0;
+ return isArrayLike(obj) ? obj.length : _.keys(obj).length;
+ };
+
+ // Split a collection into two arrays: one whose elements all satisfy the given
+ // predicate, and one whose elements all do not satisfy the predicate.
+ _.partition = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var pass = [], fail = [];
+ _.each(obj, function(value, key, obj) {
+ (predicate(value, key, obj) ? pass : fail).push(value);
+ });
+ return [pass, fail];
+ };
+
+ // Array Functions
+ // ---------------
+
+ // Get the first element of an array. Passing **n** will return the first N
+ // values in the array. Aliased as `head` and `take`. The **guard** check
+ // allows it to work with `_.map`.
+ _.first = _.head = _.take = function(array, n, guard) {
+ if (array == null) return void 0;
+ if (n == null || guard) return array[0];
+ return _.initial(array, array.length - n);
+ };
+
+ // Returns everything but the last entry of the array. Especially useful on
+ // the arguments object. Passing **n** will return all the values in
+ // the array, excluding the last N.
+ _.initial = function(array, n, guard) {
+ return slice.call(array, 0, Math.max(0, array.length - (n == null || guard ? 1 : n)));
+ };
+
+ // Get the last element of an array. Passing **n** will return the last N
+ // values in the array.
+ _.last = function(array, n, guard) {
+ if (array == null) return void 0;
+ if (n == null || guard) return array[array.length - 1];
+ return _.rest(array, Math.max(0, array.length - n));
+ };
+
+ // Returns everything but the first entry of the array. Aliased as `tail` and `drop`.
+ // Especially useful on the arguments object. Passing an **n** will return
+ // the rest N values in the array.
+ _.rest = _.tail = _.drop = function(array, n, guard) {
+ return slice.call(array, n == null || guard ? 1 : n);
+ };
+
+ // Trim out all falsy values from an array.
+ _.compact = function(array) {
+ return _.filter(array, _.identity);
+ };
+
+ // Internal implementation of a recursive `flatten` function.
+ var flatten = function(input, shallow, strict, startIndex) {
+ var output = [], idx = 0;
+ for (var i = startIndex || 0, length = getLength(input); i < length; i++) {
+ var value = input[i];
+ if (isArrayLike(value) && (_.isArray(value) || _.isArguments(value))) {
+ //flatten current level of array or arguments object
+ if (!shallow) value = flatten(value, shallow, strict);
+ var j = 0, len = value.length;
+ output.length += len;
+ while (j < len) {
+ output[idx++] = value[j++];
+ }
+ } else if (!strict) {
+ output[idx++] = value;
+ }
+ }
+ return output;
+ };
+
+ // Flatten out an array, either recursively (by default), or just one level.
+ _.flatten = function(array, shallow) {
+ return flatten(array, shallow, false);
+ };
+
+ // Return a version of the array that does not contain the specified value(s).
+ _.without = function(array) {
+ return _.difference(array, slice.call(arguments, 1));
+ };
+
+ // Produce a duplicate-free version of the array. If the array has already
+ // been sorted, you have the option of using a faster algorithm.
+ // Aliased as `unique`.
+ _.uniq = _.unique = function(array, isSorted, iteratee, context) {
+ if (!_.isBoolean(isSorted)) {
+ context = iteratee;
+ iteratee = isSorted;
+ isSorted = false;
+ }
+ if (iteratee != null) iteratee = cb(iteratee, context);
+ var result = [];
+ var seen = [];
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var value = array[i],
+ computed = iteratee ? iteratee(value, i, array) : value;
+ if (isSorted) {
+ if (!i || seen !== computed) result.push(value);
+ seen = computed;
+ } else if (iteratee) {
+ if (!_.contains(seen, computed)) {
+ seen.push(computed);
+ result.push(value);
+ }
+ } else if (!_.contains(result, value)) {
+ result.push(value);
+ }
+ }
+ return result;
+ };
+
+ // Produce an array that contains the union: each distinct element from all of
+ // the passed-in arrays.
+ _.union = function() {
+ return _.uniq(flatten(arguments, true, true));
+ };
+
+ // Produce an array that contains every item shared between all the
+ // passed-in arrays.
+ _.intersection = function(array) {
+ var result = [];
+ var argsLength = arguments.length;
+ for (var i = 0, length = getLength(array); i < length; i++) {
+ var item = array[i];
+ if (_.contains(result, item)) continue;
+ for (var j = 1; j < argsLength; j++) {
+ if (!_.contains(arguments[j], item)) break;
+ }
+ if (j === argsLength) result.push(item);
+ }
+ return result;
+ };
+
+ // Take the difference between one array and a number of other arrays.
+ // Only the elements present in just the first array will remain.
+ _.difference = function(array) {
+ var rest = flatten(arguments, true, true, 1);
+ return _.filter(array, function(value){
+ return !_.contains(rest, value);
+ });
+ };
+
+ // Zip together multiple lists into a single array -- elements that share
+ // an index go together.
+ _.zip = function() {
+ return _.unzip(arguments);
+ };
+
+ // Complement of _.zip. Unzip accepts an array of arrays and groups
+ // each array's elements on shared indices
+ _.unzip = function(array) {
+ var length = array && _.max(array, getLength).length || 0;
+ var result = Array(length);
+
+ for (var index = 0; index < length; index++) {
+ result[index] = _.pluck(array, index);
+ }
+ return result;
+ };
+
+ // Converts lists into objects. Pass either a single array of `[key, value]`
+ // pairs, or two parallel arrays of the same length -- one of keys, and one of
+ // the corresponding values.
+ _.object = function(list, values) {
+ var result = {};
+ for (var i = 0, length = getLength(list); i < length; i++) {
+ if (values) {
+ result[list[i]] = values[i];
+ } else {
+ result[list[i][0]] = list[i][1];
+ }
+ }
+ return result;
+ };
+
+ // Generator function to create the findIndex and findLastIndex functions
+ function createPredicateIndexFinder(dir) {
+ return function(array, predicate, context) {
+ predicate = cb(predicate, context);
+ var length = getLength(array);
+ var index = dir > 0 ? 0 : length - 1;
+ for (; index >= 0 && index < length; index += dir) {
+ if (predicate(array[index], index, array)) return index;
+ }
+ return -1;
+ };
+ }
+
+ // Returns the first index on an array-like that passes a predicate test
+ _.findIndex = createPredicateIndexFinder(1);
+ _.findLastIndex = createPredicateIndexFinder(-1);
+
+ // Use a comparator function to figure out the smallest index at which
+ // an object should be inserted so as to maintain order. Uses binary search.
+ _.sortedIndex = function(array, obj, iteratee, context) {
+ iteratee = cb(iteratee, context, 1);
+ var value = iteratee(obj);
+ var low = 0, high = getLength(array);
+ while (low < high) {
+ var mid = Math.floor((low + high) / 2);
+ if (iteratee(array[mid]) < value) low = mid + 1; else high = mid;
+ }
+ return low;
+ };
+
+ // Generator function to create the indexOf and lastIndexOf functions
+ function createIndexFinder(dir, predicateFind, sortedIndex) {
+ return function(array, item, idx) {
+ var i = 0, length = getLength(array);
+ if (typeof idx == 'number') {
+ if (dir > 0) {
+ i = idx >= 0 ? idx : Math.max(idx + length, i);
+ } else {
+ length = idx >= 0 ? Math.min(idx + 1, length) : idx + length + 1;
+ }
+ } else if (sortedIndex && idx && length) {
+ idx = sortedIndex(array, item);
+ return array[idx] === item ? idx : -1;
+ }
+ if (item !== item) {
+ idx = predicateFind(slice.call(array, i, length), _.isNaN);
+ return idx >= 0 ? idx + i : -1;
+ }
+ for (idx = dir > 0 ? i : length - 1; idx >= 0 && idx < length; idx += dir) {
+ if (array[idx] === item) return idx;
+ }
+ return -1;
+ };
+ }
+
+ // Return the position of the first occurrence of an item in an array,
+ // or -1 if the item is not included in the array.
+ // If the array is large and already in sort order, pass `true`
+ // for **isSorted** to use binary search.
+ _.indexOf = createIndexFinder(1, _.findIndex, _.sortedIndex);
+ _.lastIndexOf = createIndexFinder(-1, _.findLastIndex);
+
+ // Generate an integer Array containing an arithmetic progression. A port of
+ // the native Python `range()` function. See
+ // [the Python documentation](http://docs.python.org/library/functions.html#range).
+ _.range = function(start, stop, step) {
+ if (stop == null) {
+ stop = start || 0;
+ start = 0;
+ }
+ step = step || 1;
+
+ var length = Math.max(Math.ceil((stop - start) / step), 0);
+ var range = Array(length);
+
+ for (var idx = 0; idx < length; idx++, start += step) {
+ range[idx] = start;
+ }
+
+ return range;
+ };
+
+ // Function (ahem) Functions
+ // ------------------
+
+ // Determines whether to execute a function as a constructor
+ // or a normal function with the provided arguments
+ var executeBound = function(sourceFunc, boundFunc, context, callingContext, args) {
+ if (!(callingContext instanceof boundFunc)) return sourceFunc.apply(context, args);
+ var self = baseCreate(sourceFunc.prototype);
+ var result = sourceFunc.apply(self, args);
+ if (_.isObject(result)) return result;
+ return self;
+ };
+
+ // Create a function bound to a given object (assigning `this`, and arguments,
+ // optionally). Delegates to **ECMAScript 5**'s native `Function.bind` if
+ // available.
+ _.bind = function(func, context) {
+ if (nativeBind && func.bind === nativeBind) return nativeBind.apply(func, slice.call(arguments, 1));
+ if (!_.isFunction(func)) throw new TypeError('Bind must be called on a function');
+ var args = slice.call(arguments, 2);
+ var bound = function() {
+ return executeBound(func, bound, context, this, args.concat(slice.call(arguments)));
+ };
+ return bound;
+ };
+
+ // Partially apply a function by creating a version that has had some of its
+ // arguments pre-filled, without changing its dynamic `this` context. _ acts
+ // as a placeholder, allowing any combination of arguments to be pre-filled.
+ _.partial = function(func) {
+ var boundArgs = slice.call(arguments, 1);
+ var bound = function() {
+ var position = 0, length = boundArgs.length;
+ var args = Array(length);
+ for (var i = 0; i < length; i++) {
+ args[i] = boundArgs[i] === _ ? arguments[position++] : boundArgs[i];
+ }
+ while (position < arguments.length) args.push(arguments[position++]);
+ return executeBound(func, bound, this, this, args);
+ };
+ return bound;
+ };
+
+ // Bind a number of an object's methods to that object. Remaining arguments
+ // are the method names to be bound. Useful for ensuring that all callbacks
+ // defined on an object belong to it.
+ _.bindAll = function(obj) {
+ var i, length = arguments.length, key;
+ if (length <= 1) throw new Error('bindAll must be passed function names');
+ for (i = 1; i < length; i++) {
+ key = arguments[i];
+ obj[key] = _.bind(obj[key], obj);
+ }
+ return obj;
+ };
+
+ // Memoize an expensive function by storing its results.
+ _.memoize = function(func, hasher) {
+ var memoize = function(key) {
+ var cache = memoize.cache;
+ var address = '' + (hasher ? hasher.apply(this, arguments) : key);
+ if (!_.has(cache, address)) cache[address] = func.apply(this, arguments);
+ return cache[address];
+ };
+ memoize.cache = {};
+ return memoize;
+ };
+
+ // Delays a function for the given number of milliseconds, and then calls
+ // it with the arguments supplied.
+ _.delay = function(func, wait) {
+ var args = slice.call(arguments, 2);
+ return setTimeout(function(){
+ return func.apply(null, args);
+ }, wait);
+ };
+
+ // Defers a function, scheduling it to run after the current call stack has
+ // cleared.
+ _.defer = _.partial(_.delay, _, 1);
+
+ // Returns a function, that, when invoked, will only be triggered at most once
+ // during a given window of time. Normally, the throttled function will run
+ // as much as it can, without ever going more than once per `wait` duration;
+ // but if you'd like to disable the execution on the leading edge, pass
+ // `{leading: false}`. To disable execution on the trailing edge, ditto.
+ _.throttle = function(func, wait, options) {
+ var context, args, result;
+ var timeout = null;
+ var previous = 0;
+ if (!options) options = {};
+ var later = function() {
+ previous = options.leading === false ? 0 : _.now();
+ timeout = null;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ };
+ return function() {
+ var now = _.now();
+ if (!previous && options.leading === false) previous = now;
+ var remaining = wait - (now - previous);
+ context = this;
+ args = arguments;
+ if (remaining <= 0 || remaining > wait) {
+ if (timeout) {
+ clearTimeout(timeout);
+ timeout = null;
+ }
+ previous = now;
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ } else if (!timeout && options.trailing !== false) {
+ timeout = setTimeout(later, remaining);
+ }
+ return result;
+ };
+ };
+
+ // Returns a function, that, as long as it continues to be invoked, will not
+ // be triggered. The function will be called after it stops being called for
+ // N milliseconds. If `immediate` is passed, trigger the function on the
+ // leading edge, instead of the trailing.
+ _.debounce = function(func, wait, immediate) {
+ var timeout, args, context, timestamp, result;
+
+ var later = function() {
+ var last = _.now() - timestamp;
+
+ if (last < wait && last >= 0) {
+ timeout = setTimeout(later, wait - last);
+ } else {
+ timeout = null;
+ if (!immediate) {
+ result = func.apply(context, args);
+ if (!timeout) context = args = null;
+ }
+ }
+ };
+
+ return function() {
+ context = this;
+ args = arguments;
+ timestamp = _.now();
+ var callNow = immediate && !timeout;
+ if (!timeout) timeout = setTimeout(later, wait);
+ if (callNow) {
+ result = func.apply(context, args);
+ context = args = null;
+ }
+
+ return result;
+ };
+ };
+
+ // Returns the first function passed as an argument to the second,
+ // allowing you to adjust arguments, run code before and after, and
+ // conditionally execute the original function.
+ _.wrap = function(func, wrapper) {
+ return _.partial(wrapper, func);
+ };
+
+ // Returns a negated version of the passed-in predicate.
+ _.negate = function(predicate) {
+ return function() {
+ return !predicate.apply(this, arguments);
+ };
+ };
+
+ // Returns a function that is the composition of a list of functions, each
+ // consuming the return value of the function that follows.
+ _.compose = function() {
+ var args = arguments;
+ var start = args.length - 1;
+ return function() {
+ var i = start;
+ var result = args[start].apply(this, arguments);
+ while (i--) result = args[i].call(this, result);
+ return result;
+ };
+ };
+
+ // Returns a function that will only be executed on and after the Nth call.
+ _.after = function(times, func) {
+ return function() {
+ if (--times < 1) {
+ return func.apply(this, arguments);
+ }
+ };
+ };
+
+ // Returns a function that will only be executed up to (but not including) the Nth call.
+ _.before = function(times, func) {
+ var memo;
+ return function() {
+ if (--times > 0) {
+ memo = func.apply(this, arguments);
+ }
+ if (times <= 1) func = null;
+ return memo;
+ };
+ };
+
+ // Returns a function that will be executed at most one time, no matter how
+ // often you call it. Useful for lazy initialization.
+ _.once = _.partial(_.before, 2);
+
+ // Object Functions
+ // ----------------
+
+ // Keys in IE < 9 that won't be iterated by `for key in ...` and thus missed.
+ var hasEnumBug = !{toString: null}.propertyIsEnumerable('toString');
+ var nonEnumerableProps = ['valueOf', 'isPrototypeOf', 'toString',
+ 'propertyIsEnumerable', 'hasOwnProperty', 'toLocaleString'];
+
+ function collectNonEnumProps(obj, keys) {
+ var nonEnumIdx = nonEnumerableProps.length;
+ var constructor = obj.constructor;
+ var proto = (_.isFunction(constructor) && constructor.prototype) || ObjProto;
+
+ // Constructor is a special case.
+ var prop = 'constructor';
+ if (_.has(obj, prop) && !_.contains(keys, prop)) keys.push(prop);
+
+ while (nonEnumIdx--) {
+ prop = nonEnumerableProps[nonEnumIdx];
+ if (prop in obj && obj[prop] !== proto[prop] && !_.contains(keys, prop)) {
+ keys.push(prop);
+ }
+ }
+ }
+
+ // Retrieve the names of an object's own properties.
+ // Delegates to **ECMAScript 5**'s native `Object.keys`
+ _.keys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ if (nativeKeys) return nativeKeys(obj);
+ var keys = [];
+ for (var key in obj) if (_.has(obj, key)) keys.push(key);
+ // Ahem, IE < 9.
+ if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };
+
+ // Retrieve all the property names of an object.
+ _.allKeys = function(obj) {
+ if (!_.isObject(obj)) return [];
+ var keys = [];
+ for (var key in obj) keys.push(key);
+ // Ahem, IE < 9.
+ if (hasEnumBug) collectNonEnumProps(obj, keys);
+ return keys;
+ };
+
+ // Retrieve the values of an object's properties.
+ _.values = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var values = Array(length);
+ for (var i = 0; i < length; i++) {
+ values[i] = obj[keys[i]];
+ }
+ return values;
+ };
+
+ // Returns the results of applying the iteratee to each element of the object
+ // In contrast to _.map it returns an object
+ _.mapObject = function(obj, iteratee, context) {
+ iteratee = cb(iteratee, context);
+ var keys = _.keys(obj),
+ length = keys.length,
+ results = {},
+ currentKey;
+ for (var index = 0; index < length; index++) {
+ currentKey = keys[index];
+ results[currentKey] = iteratee(obj[currentKey], currentKey, obj);
+ }
+ return results;
+ };
+
+ // Convert an object into a list of `[key, value]` pairs.
+ _.pairs = function(obj) {
+ var keys = _.keys(obj);
+ var length = keys.length;
+ var pairs = Array(length);
+ for (var i = 0; i < length; i++) {
+ pairs[i] = [keys[i], obj[keys[i]]];
+ }
+ return pairs;
+ };
+
+ // Invert the keys and values of an object. The values must be serializable.
+ _.invert = function(obj) {
+ var result = {};
+ var keys = _.keys(obj);
+ for (var i = 0, length = keys.length; i < length; i++) {
+ result[obj[keys[i]]] = keys[i];
+ }
+ return result;
+ };
+
+ // Return a sorted list of the function names available on the object.
+ // Aliased as `methods`
+ _.functions = _.methods = function(obj) {
+ var names = [];
+ for (var key in obj) {
+ if (_.isFunction(obj[key])) names.push(key);
+ }
+ return names.sort();
+ };
+
+ // Extend a given object with all the properties in passed-in object(s).
+ _.extend = createAssigner(_.allKeys);
+
+ // Assigns a given object with all the own properties in the passed-in object(s)
+ // (https://developer.mozilla.org/docs/Web/JavaScript/Reference/Global_Objects/Object/assign)
+ _.extendOwn = _.assign = createAssigner(_.keys);
+
+ // Returns the first key on an object that passes a predicate test
+ _.findKey = function(obj, predicate, context) {
+ predicate = cb(predicate, context);
+ var keys = _.keys(obj), key;
+ for (var i = 0, length = keys.length; i < length; i++) {
+ key = keys[i];
+ if (predicate(obj[key], key, obj)) return key;
+ }
+ };
+
+ // Return a copy of the object only containing the whitelisted properties.
+ _.pick = function(object, oiteratee, context) {
+ var result = {}, obj = object, iteratee, keys;
+ if (obj == null) return result;
+ if (_.isFunction(oiteratee)) {
+ keys = _.allKeys(obj);
+ iteratee = optimizeCb(oiteratee, context);
+ } else {
+ keys = flatten(arguments, false, false, 1);
+ iteratee = function(value, key, obj) { return key in obj; };
+ obj = Object(obj);
+ }
+ for (var i = 0, length = keys.length; i < length; i++) {
+ var key = keys[i];
+ var value = obj[key];
+ if (iteratee(value, key, obj)) result[key] = value;
+ }
+ return result;
+ };
+
+ // Return a copy of the object without the blacklisted properties.
+ _.omit = function(obj, iteratee, context) {
+ if (_.isFunction(iteratee)) {
+ iteratee = _.negate(iteratee);
+ } else {
+ var keys = _.map(flatten(arguments, false, false, 1), String);
+ iteratee = function(value, key) {
+ return !_.contains(keys, key);
+ };
+ }
+ return _.pick(obj, iteratee, context);
+ };
+
+ // Fill in a given object with default properties.
+ _.defaults = createAssigner(_.allKeys, true);
+
+ // Creates an object that inherits from the given prototype object.
+ // If additional properties are provided then they will be added to the
+ // created object.
+ _.create = function(prototype, props) {
+ var result = baseCreate(prototype);
+ if (props) _.extendOwn(result, props);
+ return result;
+ };
+
+ // Create a (shallow-cloned) duplicate of an object.
+ _.clone = function(obj) {
+ if (!_.isObject(obj)) return obj;
+ return _.isArray(obj) ? obj.slice() : _.extend({}, obj);
+ };
+
+ // Invokes interceptor with the obj, and then returns obj.
+ // The primary purpose of this method is to "tap into" a method chain, in
+ // order to perform operations on intermediate results within the chain.
+ _.tap = function(obj, interceptor) {
+ interceptor(obj);
+ return obj;
+ };
+
+ // Returns whether an object has a given set of `key:value` pairs.
+ _.isMatch = function(object, attrs) {
+ var keys = _.keys(attrs), length = keys.length;
+ if (object == null) return !length;
+ var obj = Object(object);
+ for (var i = 0; i < length; i++) {
+ var key = keys[i];
+ if (attrs[key] !== obj[key] || !(key in obj)) return false;
+ }
+ return true;
+ };
+
+
+ // Internal recursive comparison function for `isEqual`.
+ var eq = function(a, b, aStack, bStack) {
+ // Identical objects are equal. `0 === -0`, but they aren't identical.
+ // See the [Harmony `egal` proposal](http://wiki.ecmascript.org/doku.php?id=harmony:egal).
+ if (a === b) return a !== 0 || 1 / a === 1 / b;
+ // A strict comparison is necessary because `null == undefined`.
+ if (a == null || b == null) return a === b;
+ // Unwrap any wrapped objects.
+ if (a instanceof _) a = a._wrapped;
+ if (b instanceof _) b = b._wrapped;
+ // Compare `[[Class]]` names.
+ var className = toString.call(a);
+ if (className !== toString.call(b)) return false;
+ switch (className) {
+ // Strings, numbers, regular expressions, dates, and booleans are compared by value.
+ case '[object RegExp]':
+ // RegExps are coerced to strings for comparison (Note: '' + /a/i === '/a/i')
+ case '[object String]':
+ // Primitives and their corresponding object wrappers are equivalent; thus, `"5"` is
+ // equivalent to `new String("5")`.
+ return '' + a === '' + b;
+ case '[object Number]':
+ // `NaN`s are equivalent, but non-reflexive.
+ // Object(NaN) is equivalent to NaN
+ if (+a !== +a) return +b !== +b;
+ // An `egal` comparison is performed for other numeric values.
+ return +a === 0 ? 1 / +a === 1 / b : +a === +b;
+ case '[object Date]':
+ case '[object Boolean]':
+ // Coerce dates and booleans to numeric primitive values. Dates are compared by their
+ // millisecond representations. Note that invalid dates with millisecond representations
+ // of `NaN` are not equivalent.
+ return +a === +b;
+ }
+
+ var areArrays = className === '[object Array]';
+ if (!areArrays) {
+ if (typeof a != 'object' || typeof b != 'object') return false;
+
+ // Objects with different constructors are not equivalent, but `Object`s or `Array`s
+ // from different frames are.
+ var aCtor = a.constructor, bCtor = b.constructor;
+ if (aCtor !== bCtor && !(_.isFunction(aCtor) && aCtor instanceof aCtor &&
+ _.isFunction(bCtor) && bCtor instanceof bCtor)
+ && ('constructor' in a && 'constructor' in b)) {
+ return false;
+ }
+ }
+ // Assume equality for cyclic structures. The algorithm for detecting cyclic
+ // structures is adapted from ES 5.1 section 15.12.3, abstract operation `JO`.
+
+ // Initializing stack of traversed objects.
+ // It's done here since we only need them for objects and arrays comparison.
+ aStack = aStack || [];
+ bStack = bStack || [];
+ var length = aStack.length;
+ while (length--) {
+ // Linear search. Performance is inversely proportional to the number of
+ // unique nested structures.
+ if (aStack[length] === a) return bStack[length] === b;
+ }
+
+ // Add the first object to the stack of traversed objects.
+ aStack.push(a);
+ bStack.push(b);
+
+ // Recursively compare objects and arrays.
+ if (areArrays) {
+ // Compare array lengths to determine if a deep comparison is necessary.
+ length = a.length;
+ if (length !== b.length) return false;
+ // Deep compare the contents, ignoring non-numeric properties.
+ while (length--) {
+ if (!eq(a[length], b[length], aStack, bStack)) return false;
+ }
+ } else {
+ // Deep compare objects.
+ var keys = _.keys(a), key;
+ length = keys.length;
+ // Ensure that both objects contain the same number of properties before comparing deep equality.
+ if (_.keys(b).length !== length) return false;
+ while (length--) {
+ // Deep compare each member
+ key = keys[length];
+ if (!(_.has(b, key) && eq(a[key], b[key], aStack, bStack))) return false;
+ }
+ }
+ // Remove the first object from the stack of traversed objects.
+ aStack.pop();
+ bStack.pop();
+ return true;
+ };
+
+ // Perform a deep comparison to check if two objects are equal.
+ _.isEqual = function(a, b) {
+ return eq(a, b);
+ };
+
+ // Is a given array, string, or object empty?
+ // An "empty" object has no enumerable own-properties.
+ _.isEmpty = function(obj) {
+ if (obj == null) return true;
+ if (isArrayLike(obj) && (_.isArray(obj) || _.isString(obj) || _.isArguments(obj))) return obj.length === 0;
+ return _.keys(obj).length === 0;
+ };
+
+ // Is a given value a DOM element?
+ _.isElement = function(obj) {
+ return !!(obj && obj.nodeType === 1);
+ };
+
+ // Is a given value an array?
+ // Delegates to ECMA5's native Array.isArray
+ _.isArray = nativeIsArray || function(obj) {
+ return toString.call(obj) === '[object Array]';
+ };
+
+ // Is a given variable an object?
+ _.isObject = function(obj) {
+ var type = typeof obj;
+ return type === 'function' || type === 'object' && !!obj;
+ };
+
+ // Add some isType methods: isArguments, isFunction, isString, isNumber, isDate, isRegExp, isError.
+ _.each(['Arguments', 'Function', 'String', 'Number', 'Date', 'RegExp', 'Error'], function(name) {
+ _['is' + name] = function(obj) {
+ return toString.call(obj) === '[object ' + name + ']';
+ };
+ });
+
+ // Define a fallback version of the method in browsers (ahem, IE < 9), where
+ // there isn't any inspectable "Arguments" type.
+ if (!_.isArguments(arguments)) {
+ _.isArguments = function(obj) {
+ return _.has(obj, 'callee');
+ };
+ }
+
+ // Optimize `isFunction` if appropriate. Work around some typeof bugs in old v8,
+ // IE 11 (#1621), and in Safari 8 (#1929).
+ if (typeof /./ != 'function' && typeof Int8Array != 'object') {
+ _.isFunction = function(obj) {
+ return typeof obj == 'function' || false;
+ };
+ }
+
+ // Is a given object a finite number?
+ _.isFinite = function(obj) {
+ return isFinite(obj) && !isNaN(parseFloat(obj));
+ };
+
+ // Is the given value `NaN`? (NaN is the only number which does not equal itself).
+ _.isNaN = function(obj) {
+ return _.isNumber(obj) && obj !== +obj;
+ };
+
+ // Is a given value a boolean?
+ _.isBoolean = function(obj) {
+ return obj === true || obj === false || toString.call(obj) === '[object Boolean]';
+ };
+
+ // Is a given value equal to null?
+ _.isNull = function(obj) {
+ return obj === null;
+ };
+
+ // Is a given variable undefined?
+ _.isUndefined = function(obj) {
+ return obj === void 0;
+ };
+
+ // Shortcut function for checking if an object has a given property directly
+ // on itself (in other words, not on a prototype).
+ _.has = function(obj, key) {
+ return obj != null && hasOwnProperty.call(obj, key);
+ };
+
+ // Utility Functions
+ // -----------------
+
+ // Run Underscore.js in *noConflict* mode, returning the `_` variable to its
+ // previous owner. Returns a reference to the Underscore object.
+ _.noConflict = function() {
+ root._ = previousUnderscore;
+ return this;
+ };
+
+ // Keep the identity function around for default iteratees.
+ _.identity = function(value) {
+ return value;
+ };
+
+ // Predicate-generating functions. Often useful outside of Underscore.
+ _.constant = function(value) {
+ return function() {
+ return value;
+ };
+ };
+
+ _.noop = function(){};
+
+ _.property = property;
+
+ // Generates a function for a given object that returns a given property.
+ _.propertyOf = function(obj) {
+ return obj == null ? function(){} : function(key) {
+ return obj[key];
+ };
+ };
+
+ // Returns a predicate for checking whether an object has a given set of
+ // `key:value` pairs.
+ _.matcher = _.matches = function(attrs) {
+ attrs = _.extendOwn({}, attrs);
+ return function(obj) {
+ return _.isMatch(obj, attrs);
+ };
+ };
+
+ // Run a function **n** times.
+ _.times = function(n, iteratee, context) {
+ var accum = Array(Math.max(0, n));
+ iteratee = optimizeCb(iteratee, context, 1);
+ for (var i = 0; i < n; i++) accum[i] = iteratee(i);
+ return accum;
+ };
+
+ // Return a random integer between min and max (inclusive).
+ _.random = function(min, max) {
+ if (max == null) {
+ max = min;
+ min = 0;
+ }
+ return min + Math.floor(Math.random() * (max - min + 1));
+ };
+
+ // A (possibly faster) way to get the current timestamp as an integer.
+ _.now = Date.now || function() {
+ return new Date().getTime();
+ };
+
+ // List of HTML entities for escaping.
+ var escapeMap = {
+ '&': '&',
+ '<': '<',
+ '>': '>',
+ '"': '"',
+ "'": ''',
+ '`': '`'
+ };
+ var unescapeMap = _.invert(escapeMap);
+
+ // Functions for escaping and unescaping strings to/from HTML interpolation.
+ var createEscaper = function(map) {
+ var escaper = function(match) {
+ return map[match];
+ };
+ // Regexes for identifying a key that needs to be escaped
+ var source = '(?:' + _.keys(map).join('|') + ')';
+ var testRegexp = RegExp(source);
+ var replaceRegexp = RegExp(source, 'g');
+ return function(string) {
+ string = string == null ? '' : '' + string;
+ return testRegexp.test(string) ? string.replace(replaceRegexp, escaper) : string;
+ };
+ };
+ _.escape = createEscaper(escapeMap);
+ _.unescape = createEscaper(unescapeMap);
+
+ // If the value of the named `property` is a function then invoke it with the
+ // `object` as context; otherwise, return it.
+ _.result = function(object, property, fallback) {
+ var value = object == null ? void 0 : object[property];
+ if (value === void 0) {
+ value = fallback;
+ }
+ return _.isFunction(value) ? value.call(object) : value;
+ };
+
+ // Generate a unique integer id (unique within the entire client session).
+ // Useful for temporary DOM ids.
+ var idCounter = 0;
+ _.uniqueId = function(prefix) {
+ var id = ++idCounter + '';
+ return prefix ? prefix + id : id;
+ };
+
+ // By default, Underscore uses ERB-style template delimiters, change the
+ // following template settings to use alternative delimiters.
+ _.templateSettings = {
+ evaluate : /<%([\s\S]+?)%>/g,
+ interpolate : /<%=([\s\S]+?)%>/g,
+ escape : /<%-([\s\S]+?)%>/g
+ };
+
+ // When customizing `templateSettings`, if you don't want to define an
+ // interpolation, evaluation or escaping regex, we need one that is
+ // guaranteed not to match.
+ var noMatch = /(.)^/;
+
+ // Certain characters need to be escaped so that they can be put into a
+ // string literal.
+ var escapes = {
+ "'": "'",
+ '\\': '\\',
+ '\r': 'r',
+ '\n': 'n',
+ '\u2028': 'u2028',
+ '\u2029': 'u2029'
+ };
+
+ var escaper = /\\|'|\r|\n|\u2028|\u2029/g;
+
+ var escapeChar = function(match) {
+ return '\\' + escapes[match];
+ };
+
+ // JavaScript micro-templating, similar to John Resig's implementation.
+ // Underscore templating handles arbitrary delimiters, preserves whitespace,
+ // and correctly escapes quotes within interpolated code.
+ // NB: `oldSettings` only exists for backwards compatibility.
+ _.template = function(text, settings, oldSettings) {
+ if (!settings && oldSettings) settings = oldSettings;
+ settings = _.defaults({}, settings, _.templateSettings);
+
+ // Combine delimiters into one regular expression via alternation.
+ var matcher = RegExp([
+ (settings.escape || noMatch).source,
+ (settings.interpolate || noMatch).source,
+ (settings.evaluate || noMatch).source
+ ].join('|') + '|$', 'g');
+
+ // Compile the template source, escaping string literals appropriately.
+ var index = 0;
+ var source = "__p+='";
+ text.replace(matcher, function(match, escape, interpolate, evaluate, offset) {
+ source += text.slice(index, offset).replace(escaper, escapeChar);
+ index = offset + match.length;
+
+ if (escape) {
+ source += "'+\n((__t=(" + escape + "))==null?'':_.escape(__t))+\n'";
+ } else if (interpolate) {
+ source += "'+\n((__t=(" + interpolate + "))==null?'':__t)+\n'";
+ } else if (evaluate) {
+ source += "';\n" + evaluate + "\n__p+='";
+ }
+
+ // Adobe VMs need the match returned to produce the correct offest.
+ return match;
+ });
+ source += "';\n";
+
+ // If a variable is not specified, place data values in local scope.
+ if (!settings.variable) source = 'with(obj||{}){\n' + source + '}\n';
+
+ source = "var __t,__p='',__j=Array.prototype.join," +
+ "print=function(){__p+=__j.call(arguments,'');};\n" +
+ source + 'return __p;\n';
+
+ try {
+ var render = new Function(settings.variable || 'obj', '_', source);
+ } catch (e) {
+ e.source = source;
+ throw e;
+ }
+
+ var template = function(data) {
+ return render.call(this, data, _);
+ };
+
+ // Provide the compiled source as a convenience for precompilation.
+ var argument = settings.variable || 'obj';
+ template.source = 'function(' + argument + '){\n' + source + '}';
+
+ return template;
+ };
+
+ // Add a "chain" function. Start chaining a wrapped Underscore object.
+ _.chain = function(obj) {
+ var instance = _(obj);
+ instance._chain = true;
+ return instance;
+ };
+
+ // OOP
+ // ---------------
+ // If Underscore is called as a function, it returns a wrapped object that
+ // can be used OO-style. This wrapper holds altered versions of all the
+ // underscore functions. Wrapped objects may be chained.
+
+ // Helper function to continue chaining intermediate results.
+ var result = function(instance, obj) {
+ return instance._chain ? _(obj).chain() : obj;
+ };
+
+ // Add your own custom functions to the Underscore object.
+ _.mixin = function(obj) {
+ _.each(_.functions(obj), function(name) {
+ var func = _[name] = obj[name];
+ _.prototype[name] = function() {
+ var args = [this._wrapped];
+ push.apply(args, arguments);
+ return result(this, func.apply(_, args));
+ };
+ });
+ };
+
+ // Add all of the Underscore functions to the wrapper object.
+ _.mixin(_);
+
+ // Add all mutator Array functions to the wrapper.
+ _.each(['pop', 'push', 'reverse', 'shift', 'sort', 'splice', 'unshift'], function(name) {
+ var method = ArrayProto[name];
+ _.prototype[name] = function() {
+ var obj = this._wrapped;
+ method.apply(obj, arguments);
+ if ((name === 'shift' || name === 'splice') && obj.length === 0) delete obj[0];
+ return result(this, obj);
+ };
+ });
+
+ // Add all accessor Array functions to the wrapper.
+ _.each(['concat', 'join', 'slice'], function(name) {
+ var method = ArrayProto[name];
+ _.prototype[name] = function() {
+ return result(this, method.apply(this._wrapped, arguments));
+ };
+ });
+
+ // Extracts the result from a wrapped and chained object.
+ _.prototype.value = function() {
+ return this._wrapped;
+ };
+
+ // Provide unwrapping proxy for some methods used in engine operations
+ // such as arithmetic and JSON stringification.
+ _.prototype.valueOf = _.prototype.toJSON = _.prototype.value;
+
+ _.prototype.toString = function() {
+ return '' + this._wrapped;
+ };
+
+ // AMD registration happens at the end for compatibility with AMD loaders
+ // that may not enforce next-turn semantics on modules. Even though general
+ // practice for AMD registration is to be anonymous, underscore registers
+ // as a named module because, like jQuery, it is a base library that is
+ // popular enough to be bundled in a third party lib, but not be part of
+ // an AMD load request. Those cases could generate an error when an
+ // anonymous define() is called outside of a loader request.
+ if (typeof define === 'function' && define.amd) {
+ define('underscore', [], function() {
+ return _;
+ });
+ }
+}.call(this));
Added: www-releases/trunk/8.0.0/docs/_static/up-pressed.png
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Added: www-releases/trunk/8.0.0/docs/_static/websupport.js
URL: http://llvm.org/viewvc/llvm-project/www-releases/trunk/8.0.0/docs/_static/websupport.js?rev=356539&view=auto
==============================================================================
--- www-releases/trunk/8.0.0/docs/_static/websupport.js (added)
+++ www-releases/trunk/8.0.0/docs/_static/websupport.js Wed Mar 20 02:13:27 2019
@@ -0,0 +1,808 @@
+/*
+ * websupport.js
+ * ~~~~~~~~~~~~~
+ *
+ * sphinx.websupport utilities for all documentation.
+ *
+ * :copyright: Copyright 2007-2018 by the Sphinx team, see AUTHORS.
+ * :license: BSD, see LICENSE for details.
+ *
+ */
+
+(function($) {
+ $.fn.autogrow = function() {
+ return this.each(function() {
+ var textarea = this;
+
+ $.fn.autogrow.resize(textarea);
+
+ $(textarea)
+ .focus(function() {
+ textarea.interval = setInterval(function() {
+ $.fn.autogrow.resize(textarea);
+ }, 500);
+ })
+ .blur(function() {
+ clearInterval(textarea.interval);
+ });
+ });
+ };
+
+ $.fn.autogrow.resize = function(textarea) {
+ var lineHeight = parseInt($(textarea).css('line-height'), 10);
+ var lines = textarea.value.split('\n');
+ var columns = textarea.cols;
+ var lineCount = 0;
+ $.each(lines, function() {
+ lineCount += Math.ceil(this.length / columns) || 1;
+ });
+ var height = lineHeight * (lineCount + 1);
+ $(textarea).css('height', height);
+ };
+})(jQuery);
+
+(function($) {
+ var comp, by;
+
+ function init() {
+ initEvents();
+ initComparator();
+ }
+
+ function initEvents() {
+ $(document).on("click", 'a.comment-close', function(event) {
+ event.preventDefault();
+ hide($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.vote', function(event) {
+ event.preventDefault();
+ handleVote($(this));
+ });
+ $(document).on("click", 'a.reply', function(event) {
+ event.preventDefault();
+ openReply($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.close-reply', function(event) {
+ event.preventDefault();
+ closeReply($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.sort-option', function(event) {
+ event.preventDefault();
+ handleReSort($(this));
+ });
+ $(document).on("click", 'a.show-proposal', function(event) {
+ event.preventDefault();
+ showProposal($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.hide-proposal', function(event) {
+ event.preventDefault();
+ hideProposal($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.show-propose-change', function(event) {
+ event.preventDefault();
+ showProposeChange($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.hide-propose-change', function(event) {
+ event.preventDefault();
+ hideProposeChange($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.accept-comment', function(event) {
+ event.preventDefault();
+ acceptComment($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.delete-comment', function(event) {
+ event.preventDefault();
+ deleteComment($(this).attr('id').substring(2));
+ });
+ $(document).on("click", 'a.comment-markup', function(event) {
+ event.preventDefault();
+ toggleCommentMarkupBox($(this).attr('id').substring(2));
+ });
+ }
+
+ /**
+ * Set comp, which is a comparator function used for sorting and
+ * inserting comments into the list.
+ */
+ function setComparator() {
+ // If the first three letters are "asc", sort in ascending order
+ // and remove the prefix.
+ if (by.substring(0,3) == 'asc') {
+ var i = by.substring(3);
+ comp = function(a, b) { return a[i] - b[i]; };
+ } else {
+ // Otherwise sort in descending order.
+ comp = function(a, b) { return b[by] - a[by]; };
+ }
+
+ // Reset link styles and format the selected sort option.
+ $('a.sel').attr('href', '#').removeClass('sel');
+ $('a.by' + by).removeAttr('href').addClass('sel');
+ }
+
+ /**
+ * Create a comp function. If the user has preferences stored in
+ * the sortBy cookie, use those, otherwise use the default.
+ */
+ function initComparator() {
+ by = 'rating'; // Default to sort by rating.
+ // If the sortBy cookie is set, use that instead.
+ if (document.cookie.length > 0) {
+ var start = document.cookie.indexOf('sortBy=');
+ if (start != -1) {
+ start = start + 7;
+ var end = document.cookie.indexOf(";", start);
+ if (end == -1) {
+ end = document.cookie.length;
+ by = unescape(document.cookie.substring(start, end));
+ }
+ }
+ }
+ setComparator();
+ }
+
+ /**
+ * Show a comment div.
+ */
+ function show(id) {
+ $('#ao' + id).hide();
+ $('#ah' + id).show();
+ var context = $.extend({id: id}, opts);
+ var popup = $(renderTemplate(popupTemplate, context)).hide();
+ popup.find('textarea[name="proposal"]').hide();
+ popup.find('a.by' + by).addClass('sel');
+ var form = popup.find('#cf' + id);
+ form.submit(function(event) {
+ event.preventDefault();
+ addComment(form);
+ });
+ $('#s' + id).after(popup);
+ popup.slideDown('fast', function() {
+ getComments(id);
+ });
+ }
+
+ /**
+ * Hide a comment div.
+ */
+ function hide(id) {
+ $('#ah' + id).hide();
+ $('#ao' + id).show();
+ var div = $('#sc' + id);
+ div.slideUp('fast', function() {
+ div.remove();
+ });
+ }
+
+ /**
+ * Perform an ajax request to get comments for a node
+ * and insert the comments into the comments tree.
+ */
+ function getComments(id) {
+ $.ajax({
+ type: 'GET',
+ url: opts.getCommentsURL,
+ data: {node: id},
+ success: function(data, textStatus, request) {
+ var ul = $('#cl' + id);
+ var speed = 100;
+ $('#cf' + id)
+ .find('textarea[name="proposal"]')
+ .data('source', data.source);
+
+ if (data.comments.length === 0) {
+ ul.html('<li>No comments yet.</li>');
+ ul.data('empty', true);
+ } else {
+ // If there are comments, sort them and put them in the list.
+ var comments = sortComments(data.comments);
+ speed = data.comments.length * 100;
+ appendComments(comments, ul);
+ ul.data('empty', false);
+ }
+ $('#cn' + id).slideUp(speed + 200);
+ ul.slideDown(speed);
+ },
+ error: function(request, textStatus, error) {
+ showError('Oops, there was a problem retrieving the comments.');
+ },
+ dataType: 'json'
+ });
+ }
+
+ /**
+ * Add a comment via ajax and insert the comment into the comment tree.
+ */
+ function addComment(form) {
+ var node_id = form.find('input[name="node"]').val();
+ var parent_id = form.find('input[name="parent"]').val();
+ var text = form.find('textarea[name="comment"]').val();
+ var proposal = form.find('textarea[name="proposal"]').val();
+
+ if (text == '') {
+ showError('Please enter a comment.');
+ return;
+ }
+
+ // Disable the form that is being submitted.
+ form.find('textarea,input').attr('disabled', 'disabled');
+
+ // Send the comment to the server.
+ $.ajax({
+ type: "POST",
+ url: opts.addCommentURL,
+ dataType: 'json',
+ data: {
+ node: node_id,
+ parent: parent_id,
+ text: text,
+ proposal: proposal
+ },
+ success: function(data, textStatus, error) {
+ // Reset the form.
+ if (node_id) {
+ hideProposeChange(node_id);
+ }
+ form.find('textarea')
+ .val('')
+ .add(form.find('input'))
+ .removeAttr('disabled');
+ var ul = $('#cl' + (node_id || parent_id));
+ if (ul.data('empty')) {
+ $(ul).empty();
+ ul.data('empty', false);
+ }
+ insertComment(data.comment);
+ var ao = $('#ao' + node_id);
+ ao.find('img').attr({'src': opts.commentBrightImage});
+ if (node_id) {
+ // if this was a "root" comment, remove the commenting box
+ // (the user can get it back by reopening the comment popup)
+ $('#ca' + node_id).slideUp();
+ }
+ },
+ error: function(request, textStatus, error) {
+ form.find('textarea,input').removeAttr('disabled');
+ showError('Oops, there was a problem adding the comment.');
+ }
+ });
+ }
+
+ /**
+ * Recursively append comments to the main comment list and children
+ * lists, creating the comment tree.
+ */
+ function appendComments(comments, ul) {
+ $.each(comments, function() {
+ var div = createCommentDiv(this);
+ ul.append($(document.createElement('li')).html(div));
+ appendComments(this.children, div.find('ul.comment-children'));
+ // To avoid stagnating data, don't store the comments children in data.
+ this.children = null;
+ div.data('comment', this);
+ });
+ }
+
+ /**
+ * After adding a new comment, it must be inserted in the correct
+ * location in the comment tree.
+ */
+ function insertComment(comment) {
+ var div = createCommentDiv(comment);
+
+ // To avoid stagnating data, don't store the comments children in data.
+ comment.children = null;
+ div.data('comment', comment);
+
+ var ul = $('#cl' + (comment.node || comment.parent));
+ var siblings = getChildren(ul);
+
+ var li = $(document.createElement('li'));
+ li.hide();
+
+ // Determine where in the parents children list to insert this comment.
+ for(var i=0; i < siblings.length; i++) {
+ if (comp(comment, siblings[i]) <= 0) {
+ $('#cd' + siblings[i].id)
+ .parent()
+ .before(li.html(div));
+ li.slideDown('fast');
+ return;
+ }
+ }
+
+ // If we get here, this comment rates lower than all the others,
+ // or it is the only comment in the list.
+ ul.append(li.html(div));
+ li.slideDown('fast');
+ }
+
+ function acceptComment(id) {
+ $.ajax({
+ type: 'POST',
+ url: opts.acceptCommentURL,
+ data: {id: id},
+ success: function(data, textStatus, request) {
+ $('#cm' + id).fadeOut('fast');
+ $('#cd' + id).removeClass('moderate');
+ },
+ error: function(request, textStatus, error) {
+ showError('Oops, there was a problem accepting the comment.');
+ }
+ });
+ }
+
+ function deleteComment(id) {
+ $.ajax({
+ type: 'POST',
+ url: opts.deleteCommentURL,
+ data: {id: id},
+ success: function(data, textStatus, request) {
+ var div = $('#cd' + id);
+ if (data == 'delete') {
+ // Moderator mode: remove the comment and all children immediately
+ div.slideUp('fast', function() {
+ div.remove();
+ });
+ return;
+ }
+ // User mode: only mark the comment as deleted
+ div
+ .find('span.user-id:first')
+ .text('[deleted]').end()
+ .find('div.comment-text:first')
+ .text('[deleted]').end()
+ .find('#cm' + id + ', #dc' + id + ', #ac' + id + ', #rc' + id +
+ ', #sp' + id + ', #hp' + id + ', #cr' + id + ', #rl' + id)
+ .remove();
+ var comment = div.data('comment');
+ comment.username = '[deleted]';
+ comment.text = '[deleted]';
+ div.data('comment', comment);
+ },
+ error: function(request, textStatus, error) {
+ showError('Oops, there was a problem deleting the comment.');
+ }
+ });
+ }
+
+ function showProposal(id) {
+ $('#sp' + id).hide();
+ $('#hp' + id).show();
+ $('#pr' + id).slideDown('fast');
+ }
+
+ function hideProposal(id) {
+ $('#hp' + id).hide();
+ $('#sp' + id).show();
+ $('#pr' + id).slideUp('fast');
+ }
+
+ function showProposeChange(id) {
+ $('#pc' + id).hide();
+ $('#hc' + id).show();
+ var textarea = $('#pt' + id);
+ textarea.val(textarea.data('source'));
+ $.fn.autogrow.resize(textarea[0]);
+ textarea.slideDown('fast');
+ }
+
+ function hideProposeChange(id) {
+ $('#hc' + id).hide();
+ $('#pc' + id).show();
+ var textarea = $('#pt' + id);
+ textarea.val('').removeAttr('disabled');
+ textarea.slideUp('fast');
+ }
+
+ function toggleCommentMarkupBox(id) {
+ $('#mb' + id).toggle();
+ }
+
+ /** Handle when the user clicks on a sort by link. */
+ function handleReSort(link) {
+ var classes = link.attr('class').split(/\s+/);
+ for (var i=0; i<classes.length; i++) {
+ if (classes[i] != 'sort-option') {
+ by = classes[i].substring(2);
+ }
+ }
+ setComparator();
+ // Save/update the sortBy cookie.
+ var expiration = new Date();
+ expiration.setDate(expiration.getDate() + 365);
+ document.cookie= 'sortBy=' + escape(by) +
+ ';expires=' + expiration.toUTCString();
+ $('ul.comment-ul').each(function(index, ul) {
+ var comments = getChildren($(ul), true);
+ comments = sortComments(comments);
+ appendComments(comments, $(ul).empty());
+ });
+ }
+
+ /**
+ * Function to process a vote when a user clicks an arrow.
+ */
+ function handleVote(link) {
+ if (!opts.voting) {
+ showError("You'll need to login to vote.");
+ return;
+ }
+
+ var id = link.attr('id');
+ if (!id) {
+ // Didn't click on one of the voting arrows.
+ return;
+ }
+ // If it is an unvote, the new vote value is 0,
+ // Otherwise it's 1 for an upvote, or -1 for a downvote.
+ var value = 0;
+ if (id.charAt(1) != 'u') {
+ value = id.charAt(0) == 'u' ? 1 : -1;
+ }
+ // The data to be sent to the server.
+ var d = {
+ comment_id: id.substring(2),
+ value: value
+ };
+
+ // Swap the vote and unvote links.
+ link.hide();
+ $('#' + id.charAt(0) + (id.charAt(1) == 'u' ? 'v' : 'u') + d.comment_id)
+ .show();
+
+ // The div the comment is displayed in.
+ var div = $('div#cd' + d.comment_id);
+ var data = div.data('comment');
+
+ // If this is not an unvote, and the other vote arrow has
+ // already been pressed, unpress it.
+ if ((d.value !== 0) && (data.vote === d.value * -1)) {
+ $('#' + (d.value == 1 ? 'd' : 'u') + 'u' + d.comment_id).hide();
+ $('#' + (d.value == 1 ? 'd' : 'u') + 'v' + d.comment_id).show();
+ }
+
+ // Update the comments rating in the local data.
+ data.rating += (data.vote === 0) ? d.value : (d.value - data.vote);
+ data.vote = d.value;
+ div.data('comment', data);
+
+ // Change the rating text.
+ div.find('.rating:first')
+ .text(data.rating + ' point' + (data.rating == 1 ? '' : 's'));
+
+ // Send the vote information to the server.
+ $.ajax({
+ type: "POST",
+ url: opts.processVoteURL,
+ data: d,
+ error: function(request, textStatus, error) {
+ showError('Oops, there was a problem casting that vote.');
+ }
+ });
+ }
+
+ /**
+ * Open a reply form used to reply to an existing comment.
+ */
+ function openReply(id) {
+ // Swap out the reply link for the hide link
+ $('#rl' + id).hide();
+ $('#cr' + id).show();
+
+ // Add the reply li to the children ul.
+ var div = $(renderTemplate(replyTemplate, {id: id})).hide();
+ $('#cl' + id)
+ .prepend(div)
+ // Setup the submit handler for the reply form.
+ .find('#rf' + id)
+ .submit(function(event) {
+ event.preventDefault();
+ addComment($('#rf' + id));
+ closeReply(id);
+ })
+ .find('input[type=button]')
+ .click(function() {
+ closeReply(id);
+ });
+ div.slideDown('fast', function() {
+ $('#rf' + id).find('textarea').focus();
+ });
+ }
+
+ /**
+ * Close the reply form opened with openReply.
+ */
+ function closeReply(id) {
+ // Remove the reply div from the DOM.
+ $('#rd' + id).slideUp('fast', function() {
+ $(this).remove();
+ });
+
+ // Swap out the hide link for the reply link
+ $('#cr' + id).hide();
+ $('#rl' + id).show();
+ }
+
+ /**
+ * Recursively sort a tree of comments using the comp comparator.
+ */
+ function sortComments(comments) {
+ comments.sort(comp);
+ $.each(comments, function() {
+ this.children = sortComments(this.children);
+ });
+ return comments;
+ }
+
+ /**
+ * Get the children comments from a ul. If recursive is true,
+ * recursively include childrens' children.
+ */
+ function getChildren(ul, recursive) {
+ var children = [];
+ ul.children().children("[id^='cd']")
+ .each(function() {
+ var comment = $(this).data('comment');
+ if (recursive)
+ comment.children = getChildren($(this).find('#cl' + comment.id), true);
+ children.push(comment);
+ });
+ return children;
+ }
+
+ /** Create a div to display a comment in. */
+ function createCommentDiv(comment) {
+ if (!comment.displayed && !opts.moderator) {
+ return $('<div class="moderate">Thank you! Your comment will show up '
+ + 'once it is has been approved by a moderator.</div>');
+ }
+ // Prettify the comment rating.
+ comment.pretty_rating = comment.rating + ' point' +
+ (comment.rating == 1 ? '' : 's');
+ // Make a class (for displaying not yet moderated comments differently)
+ comment.css_class = comment.displayed ? '' : ' moderate';
+ // Create a div for this comment.
+ var context = $.extend({}, opts, comment);
+ var div = $(renderTemplate(commentTemplate, context));
+
+ // If the user has voted on this comment, highlight the correct arrow.
+ if (comment.vote) {
+ var direction = (comment.vote == 1) ? 'u' : 'd';
+ div.find('#' + direction + 'v' + comment.id).hide();
+ div.find('#' + direction + 'u' + comment.id).show();
+ }
+
+ if (opts.moderator || comment.text != '[deleted]') {
+ div.find('a.reply').show();
+ if (comment.proposal_diff)
+ div.find('#sp' + comment.id).show();
+ if (opts.moderator && !comment.displayed)
+ div.find('#cm' + comment.id).show();
+ if (opts.moderator || (opts.username == comment.username))
+ div.find('#dc' + comment.id).show();
+ }
+ return div;
+ }
+
+ /**
+ * A simple template renderer. Placeholders such as <%id%> are replaced
+ * by context['id'] with items being escaped. Placeholders such as <#id#>
+ * are not escaped.
+ */
+ function renderTemplate(template, context) {
+ var esc = $(document.createElement('div'));
+
+ function handle(ph, escape) {
+ var cur = context;
+ $.each(ph.split('.'), function() {
+ cur = cur[this];
+ });
+ return escape ? esc.text(cur || "").html() : cur;
+ }
+
+ return template.replace(/<([%#])([\w\.]*)\1>/g, function() {
+ return handle(arguments[2], arguments[1] == '%' ? true : false);
+ });
+ }
+
+ /** Flash an error message briefly. */
+ function showError(message) {
+ $(document.createElement('div')).attr({'class': 'popup-error'})
+ .append($(document.createElement('div'))
+ .attr({'class': 'error-message'}).text(message))
+ .appendTo('body')
+ .fadeIn("slow")
+ .delay(2000)
+ .fadeOut("slow");
+ }
+
+ /** Add a link the user uses to open the comments popup. */
+ $.fn.comment = function() {
+ return this.each(function() {
+ var id = $(this).attr('id').substring(1);
+ var count = COMMENT_METADATA[id];
+ var title = count + ' comment' + (count == 1 ? '' : 's');
+ var image = count > 0 ? opts.commentBrightImage : opts.commentImage;
+ var addcls = count == 0 ? ' nocomment' : '';
+ $(this)
+ .append(
+ $(document.createElement('a')).attr({
+ href: '#',
+ 'class': 'sphinx-comment-open' + addcls,
+ id: 'ao' + id
+ })
+ .append($(document.createElement('img')).attr({
+ src: image,
+ alt: 'comment',
+ title: title
+ }))
+ .click(function(event) {
+ event.preventDefault();
+ show($(this).attr('id').substring(2));
+ })
+ )
+ .append(
+ $(document.createElement('a')).attr({
+ href: '#',
+ 'class': 'sphinx-comment-close hidden',
+ id: 'ah' + id
+ })
+ .append($(document.createElement('img')).attr({
+ src: opts.closeCommentImage,
+ alt: 'close',
+ title: 'close'
+ }))
+ .click(function(event) {
+ event.preventDefault();
+ hide($(this).attr('id').substring(2));
+ })
+ );
+ });
+ };
+
+ var opts = {
+ processVoteURL: '/_process_vote',
+ addCommentURL: '/_add_comment',
+ getCommentsURL: '/_get_comments',
+ acceptCommentURL: '/_accept_comment',
+ deleteCommentURL: '/_delete_comment',
+ commentImage: '/static/_static/comment.png',
+ closeCommentImage: '/static/_static/comment-close.png',
+ loadingImage: '/static/_static/ajax-loader.gif',
+ commentBrightImage: '/static/_static/comment-bright.png',
+ upArrow: '/static/_static/up.png',
+ downArrow: '/static/_static/down.png',
+ upArrowPressed: '/static/_static/up-pressed.png',
+ downArrowPressed: '/static/_static/down-pressed.png',
+ voting: false,
+ moderator: false
+ };
+
+ if (typeof COMMENT_OPTIONS != "undefined") {
+ opts = jQuery.extend(opts, COMMENT_OPTIONS);
+ }
+
+ var popupTemplate = '\
+ <div class="sphinx-comments" id="sc<%id%>">\
+ <p class="sort-options">\
+ Sort by:\
+ <a href="#" class="sort-option byrating">best rated</a>\
+ <a href="#" class="sort-option byascage">newest</a>\
+ <a href="#" class="sort-option byage">oldest</a>\
+ </p>\
+ <div class="comment-header">Comments</div>\
+ <div class="comment-loading" id="cn<%id%>">\
+ loading comments... <img src="<%loadingImage%>" alt="" /></div>\
+ <ul id="cl<%id%>" class="comment-ul"></ul>\
+ <div id="ca<%id%>">\
+ <p class="add-a-comment">Add a comment\
+ (<a href="#" class="comment-markup" id="ab<%id%>">markup</a>):</p>\
+ <div class="comment-markup-box" id="mb<%id%>">\
+ reStructured text markup: <i>*emph*</i>, <b>**strong**</b>, \
+ <code>``code``</code>, \
+ code blocks: <code>::</code> and an indented block after blank line</div>\
+ <form method="post" id="cf<%id%>" class="comment-form" action="">\
+ <textarea name="comment" cols="80"></textarea>\
+ <p class="propose-button">\
+ <a href="#" id="pc<%id%>" class="show-propose-change">\
+ Propose a change ▹\
+ </a>\
+ <a href="#" id="hc<%id%>" class="hide-propose-change">\
+ Propose a change ▿\
+ </a>\
+ </p>\
+ <textarea name="proposal" id="pt<%id%>" cols="80"\
+ spellcheck="false"></textarea>\
+ <input type="submit" value="Add comment" />\
+ <input type="hidden" name="node" value="<%id%>" />\
+ <input type="hidden" name="parent" value="" />\
+ </form>\
+ </div>\
+ </div>';
+
+ var commentTemplate = '\
+ <div id="cd<%id%>" class="sphinx-comment<%css_class%>">\
+ <div class="vote">\
+ <div class="arrow">\
+ <a href="#" id="uv<%id%>" class="vote" title="vote up">\
+ <img src="<%upArrow%>" />\
+ </a>\
+ <a href="#" id="uu<%id%>" class="un vote" title="vote up">\
+ <img src="<%upArrowPressed%>" />\
+ </a>\
+ </div>\
+ <div class="arrow">\
+ <a href="#" id="dv<%id%>" class="vote" title="vote down">\
+ <img src="<%downArrow%>" id="da<%id%>" />\
+ </a>\
+ <a href="#" id="du<%id%>" class="un vote" title="vote down">\
+ <img src="<%downArrowPressed%>" />\
+ </a>\
+ </div>\
+ </div>\
+ <div class="comment-content">\
+ <p class="tagline comment">\
+ <span class="user-id"><%username%></span>\
+ <span class="rating"><%pretty_rating%></span>\
+ <span class="delta"><%time.delta%></span>\
+ </p>\
+ <div class="comment-text comment"><#text#></div>\
+ <p class="comment-opts comment">\
+ <a href="#" class="reply hidden" id="rl<%id%>">reply ▹</a>\
+ <a href="#" class="close-reply" id="cr<%id%>">reply ▿</a>\
+ <a href="#" id="sp<%id%>" class="show-proposal">proposal ▹</a>\
+ <a href="#" id="hp<%id%>" class="hide-proposal">proposal ▿</a>\
+ <a href="#" id="dc<%id%>" class="delete-comment hidden">delete</a>\
+ <span id="cm<%id%>" class="moderation hidden">\
+ <a href="#" id="ac<%id%>" class="accept-comment">accept</a>\
+ </span>\
+ </p>\
+ <pre class="proposal" id="pr<%id%>">\
+<#proposal_diff#>\
+ </pre>\
+ <ul class="comment-children" id="cl<%id%>"></ul>\
+ </div>\
+ <div class="clearleft"></div>\
+ </div>\
+ </div>';
+
+ var replyTemplate = '\
+ <li>\
+ <div class="reply-div" id="rd<%id%>">\
+ <form id="rf<%id%>">\
+ <textarea name="comment" cols="80"></textarea>\
+ <input type="submit" value="Add reply" />\
+ <input type="button" value="Cancel" />\
+ <input type="hidden" name="parent" value="<%id%>" />\
+ <input type="hidden" name="node" value="" />\
+ </form>\
+ </div>\
+ </li>';
+
+ $(document).ready(function() {
+ init();
+ });
+})(jQuery);
+
+$(document).ready(function() {
+ // add comment anchors for all paragraphs that are commentable
+ $('.sphinx-has-comment').comment();
+
+ // highlight search words in search results
+ $("div.context").each(function() {
+ var params = $.getQueryParameters();
+ var terms = (params.q) ? params.q[0].split(/\s+/) : [];
+ var result = $(this);
+ $.each(terms, function() {
+ result.highlightText(this.toLowerCase(), 'highlighted');
+ });
+ });
+
+ // directly open comment window if requested
+ var anchor = document.location.hash;
+ if (anchor.substring(0, 9) == '#comment-') {
+ $('#ao' + anchor.substring(9)).click();
+ document.location.hash = '#s' + anchor.substring(9);
+ }
+});
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