[llvm] r223671 - Add Chapter 8 to the Kaleidoscope tutorial. This chapter adds
Eric Christopher
echristo at gmail.com
Mon Dec 8 10:00:47 PST 2014
Author: echristo
Date: Mon Dec 8 12:00:47 2014
New Revision: 223671
URL: http://llvm.org/viewvc/llvm-project?rev=223671&view=rev
Log:
Add Chapter 8 to the Kaleidoscope tutorial. This chapter adds
a description of how to add debug information using DWARF and
DIBuilder to the language.
Thanks to David Blaikie for his assistance with this tutorial.
Added:
llvm/trunk/docs/tutorial/LangImpl9.rst
- copied, changed from r223670, llvm/trunk/docs/tutorial/LangImpl8.rst
llvm/trunk/examples/Kaleidoscope/Chapter8/
llvm/trunk/examples/Kaleidoscope/Chapter8/CMakeLists.txt
llvm/trunk/examples/Kaleidoscope/Chapter8/Makefile
- copied, changed from r223670, llvm/trunk/examples/Kaleidoscope/Makefile
llvm/trunk/examples/Kaleidoscope/Chapter8/toy.cpp
Modified:
llvm/trunk/docs/tutorial/LangImpl8.rst
llvm/trunk/examples/Kaleidoscope/Makefile
Modified: llvm/trunk/docs/tutorial/LangImpl8.rst
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl8.rst?rev=223671&r1=223670&r2=223671&view=diff
==============================================================================
--- llvm/trunk/docs/tutorial/LangImpl8.rst (original)
+++ llvm/trunk/docs/tutorial/LangImpl8.rst Mon Dec 8 12:00:47 2014
@@ -1,267 +1,425 @@
-======================================================
-Kaleidoscope: Conclusion and other useful LLVM tidbits
-======================================================
+=======================================================
+Kaleidoscope: Extending the Language: Debug Information
+=======================================================
.. contents::
:local:
-Tutorial Conclusion
-===================
+Chapter 8 Introduction
+======================
-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#i_getelementptr>`_ 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 `llvmdev mailing
-list <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>`_: 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 `llvmdev
-mailing list <http://lists.cs.uiuc.edu/mailman/listinfo/llvmdev>`_ 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 llvmdev 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).
+Welcome to Chapter 8 of the "`Implementing a language with
+LLVM <index.html>`_" tutorial. In chapters 1 through 7, 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
+
+- PrototypeAST *Proto = new PrototypeAST("", std::vector<std::string>());
++ PrototypeAST *Proto = new 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 (FunctionAST *F = ParseTopLevelExpr()) {
+- if (Function *LF = F->Codegen()) {
+- // We're just doing this to make sure it executes.
+- TheExecutionEngine->finalizeObject();
+- // JIT the function, returning a function pointer.
+- void *FPtr = TheExecutionEngine->getPointerToFunction(LF);
+-
+- // 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-Ch8 < 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.isValid())
+ return DblTy;
+
+ DblTy = DBuilder->createBasicType("double", 64, 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, "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 a 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++
+
+ DIDescriptor FContext(Unit);
+ unsigned LineNo = 0;
+ unsigned ScopeLine = 0;
+ DISubprogram SP = DBuilder->createFunction(
+ FContext, Name, StringRef(), Unit, LineNo,
+ CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
+ true /* definition */, ScopeLine, DIDescriptor::FlagPrototyped, false, F);
+
+and we now have a 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:
+ int getLine() const { return Loc.Line; }
+ int getCol() const { return Loc.Col; }
+ ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ return out << ':' << getLine() << ':' << getCol() << '\n';
+ }
+
+that we pass down through when we create a new expression:
+
+.. code-block:: c++
+
+ LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
+
+giving us locations for each of our expressions and variables.
+
+From this we can make sure to tell ``DIBuilder`` when we're at a new source
+location so it can use that when we generate the rest of our code and make
+sure that each instruction has source location information. We do this
+by constructing another small function:
+
+.. 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(), DIScope(*Scope)));
+ }
+
+that both tells the main ``IRBuilder`` where we are, but also what scope
+we're in. Since we've just created a function above we can either be in
+the main file scope (like when we created our function), or now we can be
+in the function scope we just created. To represent this we create a stack
+of scopes:
+
+.. code-block:: c++
+
+ std::vector<DIScope *> LexicalBlocks;
+ std::map<const PrototypeAST *, DIScope> FnScopeMap;
+
+and keep a map of each function to the scope that it represents (a DISubprogram
+is also a DIScope).
+
+Then we make sure to:
+
+.. code-block:: c++
+
+ KSDbgInfo.emitLocation(this);
+
+emit the location every time we start to generate code for a new AST, and
+also:
+
+.. code-block:: c++
+
+ KSDbgInfo.FnScopeMap[this] = SP;
+
+store the scope (function) when we create it and use it:
+
+ KSDbgInfo.LexicalBlocks.push_back(&KSDbgInfo.FnScopeMap[Proto]);
+
+when we start generating the code for each function.
+
+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 a couple of 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);
+
+also, don't forget to pop the scope back off of your 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();
+
+
+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 jit native` -O3 -o toy
+ # Run
+ ./toy
+
+Here is the code:
+
+.. literalinclude:: ../../examples/Kaleidoscope/Chapter8/toy.cpp
+ :language: c++
+
+`Next: Conclusion and other useful LLVM tidbits <LangImpl9.html>`_
Copied: llvm/trunk/docs/tutorial/LangImpl9.rst (from r223670, llvm/trunk/docs/tutorial/LangImpl8.rst)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/docs/tutorial/LangImpl9.rst?p2=llvm/trunk/docs/tutorial/LangImpl9.rst&p1=llvm/trunk/docs/tutorial/LangImpl8.rst&r1=223670&r2=223671&rev=223671&view=diff
==============================================================================
(empty)
Added: llvm/trunk/examples/Kaleidoscope/Chapter8/CMakeLists.txt
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/examples/Kaleidoscope/Chapter8/CMakeLists.txt?rev=223671&view=auto
==============================================================================
--- llvm/trunk/examples/Kaleidoscope/Chapter8/CMakeLists.txt (added)
+++ llvm/trunk/examples/Kaleidoscope/Chapter8/CMakeLists.txt Mon Dec 8 12:00:47 2014
@@ -0,0 +1,17 @@
+set(LLVM_LINK_COMPONENTS
+ Analysis
+ Core
+ ExecutionEngine
+ InstCombine
+ MC
+ ScalarOpts
+ Support
+ TransformUtils
+ nativecodegen
+ )
+
+set(LLVM_REQUIRES_RTTI 1)
+
+add_llvm_example(Kaleidoscope-Ch8
+ toy.cpp
+ )
Copied: llvm/trunk/examples/Kaleidoscope/Chapter8/Makefile (from r223670, llvm/trunk/examples/Kaleidoscope/Makefile)
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/examples/Kaleidoscope/Chapter8/Makefile?p2=llvm/trunk/examples/Kaleidoscope/Chapter8/Makefile&p1=llvm/trunk/examples/Kaleidoscope/Makefile&r1=223670&r2=223671&rev=223671&view=diff
==============================================================================
--- llvm/trunk/examples/Kaleidoscope/Makefile (original)
+++ llvm/trunk/examples/Kaleidoscope/Chapter8/Makefile Mon Dec 8 12:00:47 2014
@@ -1,4 +1,4 @@
-##===- examples/Kaleidoscope/Makefile ----------------------*- Makefile -*-===##
+##===- examples/Kaleidoscope/Chapter7/Makefile -------------*- Makefile -*-===##
#
# The LLVM Compiler Infrastructure
#
@@ -6,10 +6,11 @@
# License. See LICENSE.TXT for details.
#
##===----------------------------------------------------------------------===##
-LEVEL=../..
+LEVEL = ../../..
+TOOLNAME = Kaleidoscope-Ch8
+EXAMPLE_TOOL = 1
+REQUIRES_RTTI := 1
-include $(LEVEL)/Makefile.config
-
-PARALLEL_DIRS:= Chapter2 Chapter3 Chapter4 Chapter5 Chapter6 Chapter7
+LINK_COMPONENTS := core mcjit native
include $(LEVEL)/Makefile.common
Added: llvm/trunk/examples/Kaleidoscope/Chapter8/toy.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/examples/Kaleidoscope/Chapter8/toy.cpp?rev=223671&view=auto
==============================================================================
--- llvm/trunk/examples/Kaleidoscope/Chapter8/toy.cpp (added)
+++ llvm/trunk/examples/Kaleidoscope/Chapter8/toy.cpp Mon Dec 8 12:00:47 2014
@@ -0,0 +1,1493 @@
+#include "llvm/ADT/Triple.h"
+#include "llvm/Analysis/Passes.h"
+#include "llvm/ExecutionEngine/ExecutionEngine.h"
+#include "llvm/ExecutionEngine/MCJIT.h"
+#include "llvm/ExecutionEngine/SectionMemoryManager.h"
+#include "llvm/IR/DataLayout.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/DIBuilder.h"
+#include "llvm/IR/IRBuilder.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Module.h"
+#include "llvm/IR/Verifier.h"
+#include "llvm/PassManager.h"
+#include "llvm/Support/Host.h"
+#include "llvm/Support/TargetSelect.h"
+#include "llvm/Transforms/Scalar.h"
+#include <cctype>
+#include <cstdio>
+#include <map>
+#include <string>
+#include <vector>
+#include <iostream>
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// Lexer
+//===----------------------------------------------------------------------===//
+
+// The lexer returns tokens [0-255] if it is an unknown character, otherwise one
+// of these for known things.
+enum Token {
+ tok_eof = -1,
+
+ // commands
+ tok_def = -2,
+ tok_extern = -3,
+
+ // primary
+ tok_identifier = -4,
+ tok_number = -5,
+
+ // control
+ tok_if = -6,
+ tok_then = -7,
+ tok_else = -8,
+ tok_for = -9,
+ tok_in = -10,
+
+ // operators
+ tok_binary = -11,
+ tok_unary = -12,
+
+ // var definition
+ tok_var = -13
+};
+
+std::string getTokName(int Tok) {
+ switch (Tok) {
+ case tok_eof:
+ return "eof";
+ case tok_def:
+ return "def";
+ case tok_extern:
+ return "extern";
+ case tok_identifier:
+ return "identifier";
+ case tok_number:
+ return "number";
+ case tok_if:
+ return "if";
+ case tok_then:
+ return "then";
+ case tok_else:
+ return "else";
+ case tok_for:
+ return "for";
+ case tok_in:
+ return "in";
+ case tok_binary:
+ return "binary";
+ case tok_unary:
+ return "unary";
+ case tok_var:
+ return "var";
+ }
+ return std::string(1, (char)Tok);
+}
+
+namespace {
+class PrototypeAST;
+class ExprAST;
+}
+static IRBuilder<> Builder(getGlobalContext());
+struct DebugInfo {
+ DICompileUnit TheCU;
+ DIType DblTy;
+ std::vector<DIScope *> LexicalBlocks;
+ std::map<const PrototypeAST *, DIScope> FnScopeMap;
+
+ void emitLocation(ExprAST *AST);
+ DIType getDoubleTy();
+} KSDbgInfo;
+
+static std::string IdentifierStr; // Filled in if tok_identifier
+static double NumVal; // Filled in if tok_number
+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;
+}
+
+/// gettok - Return the next token from standard input.
+static int gettok() {
+ static int LastChar = ' ';
+
+ // Skip any whitespace.
+ while (isspace(LastChar))
+ LastChar = advance();
+
+ CurLoc = LexLoc;
+
+ if (isalpha(LastChar)) { // identifier: [a-zA-Z][a-zA-Z0-9]*
+ IdentifierStr = LastChar;
+ while (isalnum((LastChar = advance())))
+ IdentifierStr += LastChar;
+
+ 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;
+ if (IdentifierStr == "binary")
+ return tok_binary;
+ if (IdentifierStr == "unary")
+ return tok_unary;
+ if (IdentifierStr == "var")
+ return tok_var;
+ return tok_identifier;
+ }
+
+ if (isdigit(LastChar) || LastChar == '.') { // Number: [0-9.]+
+ std::string NumStr;
+ do {
+ NumStr += LastChar;
+ LastChar = advance();
+ } while (isdigit(LastChar) || LastChar == '.');
+
+ NumVal = strtod(NumStr.c_str(), 0);
+ return tok_number;
+ }
+
+ if (LastChar == '#') {
+ // Comment until end of line.
+ do
+ LastChar = advance();
+ while (LastChar != EOF && LastChar != '\n' && LastChar != '\r');
+
+ if (LastChar != EOF)
+ return gettok();
+ }
+
+ // Check for end of file. Don't eat the EOF.
+ if (LastChar == EOF)
+ return tok_eof;
+
+ // Otherwise, just return the character as its ascii value.
+ int ThisChar = LastChar;
+ LastChar = advance();
+ return ThisChar;
+}
+
+//===----------------------------------------------------------------------===//
+// Abstract Syntax Tree (aka Parse Tree)
+//===----------------------------------------------------------------------===//
+namespace {
+
+std::ostream &indent(std::ostream &O, int size) {
+ return O << std::string(size, ' ');
+}
+
+/// ExprAST - Base class for all expression nodes.
+class ExprAST {
+ SourceLocation Loc;
+
+public:
+ int getLine() const { return Loc.Line; }
+ int getCol() const { return Loc.Col; }
+ ExprAST(SourceLocation Loc = CurLoc) : Loc(Loc) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ return out << ':' << getLine() << ':' << getCol() << '\n';
+ }
+ 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 std::ostream &dump(std::ostream &out, int ind) {
+ return ExprAST::dump(out << Val, ind);
+ }
+ virtual Value *Codegen();
+};
+
+/// VariableExprAST - Expression class for referencing a variable, like "a".
+class VariableExprAST : public ExprAST {
+ std::string Name;
+
+public:
+ VariableExprAST(SourceLocation Loc, const std::string &name)
+ : ExprAST(Loc), Name(name) {}
+ const std::string &getName() const { return Name; }
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ return ExprAST::dump(out << Name, ind);
+ }
+ virtual Value *Codegen();
+};
+
+/// UnaryExprAST - Expression class for a unary operator.
+class UnaryExprAST : public ExprAST {
+ char Opcode;
+ ExprAST *Operand;
+
+public:
+ UnaryExprAST(char opcode, ExprAST *operand)
+ : Opcode(opcode), Operand(operand) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "unary" << Opcode, ind);
+ Operand->dump(out, ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// BinaryExprAST - Expression class for a binary operator.
+class BinaryExprAST : public ExprAST {
+ char Op;
+ ExprAST *LHS, *RHS;
+
+public:
+ BinaryExprAST(SourceLocation Loc, char op, ExprAST *lhs, ExprAST *rhs)
+ : ExprAST(Loc), Op(op), LHS(lhs), RHS(rhs) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "binary" << Op, ind);
+ LHS->dump(indent(out, ind) << "LHS:", ind + 1);
+ RHS->dump(indent(out, ind) << "RHS:", ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// CallExprAST - Expression class for function calls.
+class CallExprAST : public ExprAST {
+ std::string Callee;
+ std::vector<ExprAST *> Args;
+
+public:
+ CallExprAST(SourceLocation Loc, const std::string &callee,
+ std::vector<ExprAST *> &args)
+ : ExprAST(Loc), Callee(callee), Args(args) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "call " << Callee, ind);
+ for (ExprAST *Arg : Args)
+ Arg->dump(indent(out, ind + 1), ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// IfExprAST - Expression class for if/then/else.
+class IfExprAST : public ExprAST {
+ ExprAST *Cond, *Then, *Else;
+
+public:
+ IfExprAST(SourceLocation Loc, ExprAST *cond, ExprAST *then, ExprAST *_else)
+ : ExprAST(Loc), Cond(cond), Then(then), Else(_else) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "if", ind);
+ Cond->dump(indent(out, ind) << "Cond:", ind + 1);
+ Then->dump(indent(out, ind) << "Then:", ind + 1);
+ Else->dump(indent(out, ind) << "Else:", ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// ForExprAST - Expression class for for/in.
+class ForExprAST : public ExprAST {
+ std::string VarName;
+ ExprAST *Start, *End, *Step, *Body;
+
+public:
+ ForExprAST(const std::string &varname, ExprAST *start, ExprAST *end,
+ ExprAST *step, ExprAST *body)
+ : VarName(varname), Start(start), End(end), Step(step), Body(body) {}
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "for", ind);
+ Start->dump(indent(out, ind) << "Cond:", ind + 1);
+ End->dump(indent(out, ind) << "End:", ind + 1);
+ Step->dump(indent(out, ind) << "Step:", ind + 1);
+ Body->dump(indent(out, ind) << "Body:", ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// VarExprAST - Expression class for var/in
+class VarExprAST : public ExprAST {
+ std::vector<std::pair<std::string, ExprAST *> > VarNames;
+ ExprAST *Body;
+
+public:
+ VarExprAST(const std::vector<std::pair<std::string, ExprAST *> > &varnames,
+ ExprAST *body)
+ : VarNames(varnames), Body(body) {}
+
+ virtual std::ostream &dump(std::ostream &out, int ind) {
+ ExprAST::dump(out << "var", ind);
+ for (const auto &NamedVar : VarNames)
+ NamedVar.second->dump(indent(out, ind) << NamedVar.first << ':', ind + 1);
+ Body->dump(indent(out, ind) << "Body:", ind + 1);
+ return out;
+ }
+ virtual Value *Codegen();
+};
+
+/// 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.
+ int Line;
+
+public:
+ PrototypeAST(SourceLocation Loc, const std::string &name,
+ const std::vector<std::string> &args, bool isoperator = false,
+ unsigned prec = 0)
+ : Name(name), Args(args), isOperator(isoperator), Precedence(prec),
+ Line(Loc.Line) {}
+
+ 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; }
+
+ Function *Codegen();
+
+ void CreateArgumentAllocas(Function *F);
+ const std::vector<std::string> &getArgs() const { return Args; }
+};
+
+/// FunctionAST - This class represents a function definition itself.
+class FunctionAST {
+ PrototypeAST *Proto;
+ ExprAST *Body;
+
+public:
+ FunctionAST(PrototypeAST *proto, ExprAST *body) : Proto(proto), Body(body) {}
+
+ std::ostream &dump(std::ostream &out, int ind) {
+ indent(out, ind) << "FunctionAST\n";
+ ++ind;
+ indent(out, ind) << "Body:";
+ return Body ? Body->dump(out, ind) : out << "null\n";
+ }
+
+ Function *Codegen();
+};
+} // end anonymous namespace
+
+//===----------------------------------------------------------------------===//
+// Parser
+//===----------------------------------------------------------------------===//
+
+/// CurTok/getNextToken - Provide a simple token buffer. CurTok is the current
+/// token the parser is looking at. getNextToken reads another token from the
+/// lexer and updates CurTok with its results.
+static int CurTok;
+static int getNextToken() { return CurTok = gettok(); }
+
+/// BinopPrecedence - This holds the precedence for each binary operator that is
+/// defined.
+static std::map<char, int> BinopPrecedence;
+
+/// GetTokPrecedence - Get the precedence of the pending binary operator token.
+static int GetTokPrecedence() {
+ if (!isascii(CurTok))
+ return -1;
+
+ // Make sure it's a declared binop.
+ int TokPrec = BinopPrecedence[CurTok];
+ if (TokPrec <= 0)
+ return -1;
+ return TokPrec;
+}
+
+/// Error* - These are little helper functions for error handling.
+ExprAST *Error(const char *Str) {
+ fprintf(stderr, "Error: %s\n", Str);
+ return 0;
+}
+PrototypeAST *ErrorP(const char *Str) {
+ Error(Str);
+ return 0;
+}
+FunctionAST *ErrorF(const char *Str) {
+ Error(Str);
+ return 0;
+}
+
+static ExprAST *ParseExpression();
+
+/// identifierexpr
+/// ::= identifier
+/// ::= identifier '(' expression* ')'
+static ExprAST *ParseIdentifierExpr() {
+ std::string IdName = IdentifierStr;
+
+ SourceLocation LitLoc = CurLoc;
+
+ getNextToken(); // eat identifier.
+
+ if (CurTok != '(') // Simple variable ref.
+ return new VariableExprAST(LitLoc, IdName);
+
+ // Call.
+ getNextToken(); // eat (
+ std::vector<ExprAST *> Args;
+ if (CurTok != ')') {
+ while (1) {
+ ExprAST *Arg = ParseExpression();
+ if (!Arg)
+ return 0;
+ Args.push_back(Arg);
+
+ if (CurTok == ')')
+ break;
+
+ if (CurTok != ',')
+ return Error("Expected ')' or ',' in argument list");
+ getNextToken();
+ }
+ }
+
+ // Eat the ')'.
+ getNextToken();
+
+ return new CallExprAST(LitLoc, IdName, Args);
+}
+
+/// numberexpr ::= number
+static ExprAST *ParseNumberExpr() {
+ ExprAST *Result = new NumberExprAST(NumVal);
+ getNextToken(); // consume the number
+ return Result;
+}
+
+/// parenexpr ::= '(' expression ')'
+static ExprAST *ParseParenExpr() {
+ getNextToken(); // eat (.
+ ExprAST *V = ParseExpression();
+ if (!V)
+ return 0;
+
+ if (CurTok != ')')
+ return Error("expected ')'");
+ getNextToken(); // eat ).
+ return V;
+}
+
+/// ifexpr ::= 'if' expression 'then' expression 'else' expression
+static ExprAST *ParseIfExpr() {
+ SourceLocation IfLoc = CurLoc;
+
+ getNextToken(); // eat the if.
+
+ // condition.
+ ExprAST *Cond = ParseExpression();
+ if (!Cond)
+ return 0;
+
+ if (CurTok != tok_then)
+ return Error("expected then");
+ getNextToken(); // eat the then
+
+ ExprAST *Then = ParseExpression();
+ if (Then == 0)
+ return 0;
+
+ if (CurTok != tok_else)
+ return Error("expected else");
+
+ getNextToken();
+
+ ExprAST *Else = ParseExpression();
+ if (!Else)
+ return 0;
+
+ return new IfExprAST(IfLoc, Cond, Then, Else);
+}
+
+/// forexpr ::= 'for' identifier '=' expr ',' expr (',' expr)? 'in' expression
+static ExprAST *ParseForExpr() {
+ getNextToken(); // eat the for.
+
+ if (CurTok != tok_identifier)
+ return Error("expected identifier after for");
+
+ std::string IdName = IdentifierStr;
+ getNextToken(); // eat identifier.
+
+ if (CurTok != '=')
+ return Error("expected '=' after for");
+ getNextToken(); // eat '='.
+
+ ExprAST *Start = ParseExpression();
+ if (Start == 0)
+ return 0;
+ if (CurTok != ',')
+ return Error("expected ',' after for start value");
+ getNextToken();
+
+ ExprAST *End = ParseExpression();
+ if (End == 0)
+ return 0;
+
+ // The step value is optional.
+ ExprAST *Step = 0;
+ if (CurTok == ',') {
+ getNextToken();
+ Step = ParseExpression();
+ if (Step == 0)
+ return 0;
+ }
+
+ if (CurTok != tok_in)
+ return Error("expected 'in' after for");
+ getNextToken(); // eat 'in'.
+
+ ExprAST *Body = ParseExpression();
+ if (Body == 0)
+ return 0;
+
+ return new ForExprAST(IdName, Start, End, Step, Body);
+}
+
+/// varexpr ::= 'var' identifier ('=' expression)?
+// (',' identifier ('=' expression)?)* 'in' expression
+static ExprAST *ParseVarExpr() {
+ getNextToken(); // eat the var.
+
+ std::vector<std::pair<std::string, ExprAST *> > VarNames;
+
+ // At least one variable name is required.
+ if (CurTok != tok_identifier)
+ return Error("expected identifier after var");
+
+ while (1) {
+ std::string Name = IdentifierStr;
+ getNextToken(); // eat identifier.
+
+ // Read the optional initializer.
+ ExprAST *Init = 0;
+ if (CurTok == '=') {
+ getNextToken(); // eat the '='.
+
+ Init = ParseExpression();
+ if (Init == 0)
+ return 0;
+ }
+
+ VarNames.push_back(std::make_pair(Name, Init));
+
+ // End of var list, exit loop.
+ if (CurTok != ',')
+ break;
+ getNextToken(); // eat the ','.
+
+ if (CurTok != tok_identifier)
+ return Error("expected identifier list after var");
+ }
+
+ // At this point, we have to have 'in'.
+ if (CurTok != tok_in)
+ return Error("expected 'in' keyword after 'var'");
+ getNextToken(); // eat 'in'.
+
+ ExprAST *Body = ParseExpression();
+ if (Body == 0)
+ return 0;
+
+ return new VarExprAST(VarNames, Body);
+}
+
+/// primary
+/// ::= identifierexpr
+/// ::= numberexpr
+/// ::= parenexpr
+/// ::= ifexpr
+/// ::= forexpr
+/// ::= varexpr
+static ExprAST *ParsePrimary() {
+ switch (CurTok) {
+ default:
+ return Error("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();
+ }
+}
+
+/// unary
+/// ::= primary
+/// ::= '!' unary
+static 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 (ExprAST *Operand = ParseUnary())
+ return new UnaryExprAST(Opc, Operand);
+ return 0;
+}
+
+/// binoprhs
+/// ::= ('+' unary)*
+static ExprAST *ParseBinOpRHS(int ExprPrec, ExprAST *LHS) {
+ // If this is a binop, find its precedence.
+ while (1) {
+ int TokPrec = GetTokPrecedence();
+
+ // If this is a binop that binds at least as tightly as the current binop,
+ // consume it, otherwise we are done.
+ if (TokPrec < ExprPrec)
+ return LHS;
+
+ // Okay, we know this is a binop.
+ int BinOp = CurTok;
+ SourceLocation BinLoc = CurLoc;
+ getNextToken(); // eat binop
+
+ // Parse the unary expression after the binary operator.
+ ExprAST *RHS = ParseUnary();
+ if (!RHS)
+ return 0;
+
+ // If BinOp binds less tightly with RHS than the operator after RHS, let
+ // the pending operator take RHS as its LHS.
+ int NextPrec = GetTokPrecedence();
+ if (TokPrec < NextPrec) {
+ RHS = ParseBinOpRHS(TokPrec + 1, RHS);
+ if (RHS == 0)
+ return 0;
+ }
+
+ // Merge LHS/RHS.
+ LHS = new BinaryExprAST(BinLoc, BinOp, LHS, RHS);
+ }
+}
+
+/// expression
+/// ::= unary binoprhs
+///
+static ExprAST *ParseExpression() {
+ ExprAST *LHS = ParseUnary();
+ if (!LHS)
+ return 0;
+
+ return ParseBinOpRHS(0, LHS);
+}
+
+/// prototype
+/// ::= id '(' id* ')'
+/// ::= binary LETTER number? (id, id)
+/// ::= unary LETTER (id)
+static PrototypeAST *ParsePrototype() {
+ std::string FnName;
+
+ SourceLocation FnLoc = CurLoc;
+
+ unsigned Kind = 0; // 0 = identifier, 1 = unary, 2 = binary.
+ unsigned BinaryPrecedence = 30;
+
+ switch (CurTok) {
+ default:
+ return ErrorP("Expected function name in prototype");
+ case tok_identifier:
+ FnName = IdentifierStr;
+ Kind = 0;
+ getNextToken();
+ break;
+ case tok_unary:
+ getNextToken();
+ if (!isascii(CurTok))
+ return ErrorP("Expected unary operator");
+ FnName = "unary";
+ FnName += (char)CurTok;
+ Kind = 1;
+ getNextToken();
+ break;
+ case tok_binary:
+ getNextToken();
+ if (!isascii(CurTok))
+ return ErrorP("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 ErrorP("Invalid precedecnce: must be 1..100");
+ BinaryPrecedence = (unsigned)NumVal;
+ getNextToken();
+ }
+ break;
+ }
+
+ if (CurTok != '(')
+ return ErrorP("Expected '(' in prototype");
+
+ std::vector<std::string> ArgNames;
+ while (getNextToken() == tok_identifier)
+ ArgNames.push_back(IdentifierStr);
+ if (CurTok != ')')
+ return ErrorP("Expected ')' in prototype");
+
+ // success.
+ getNextToken(); // eat ')'.
+
+ // Verify right number of names for operator.
+ if (Kind && ArgNames.size() != Kind)
+ return ErrorP("Invalid number of operands for operator");
+
+ return new PrototypeAST(FnLoc, FnName, ArgNames, Kind != 0, BinaryPrecedence);
+}
+
+/// definition ::= 'def' prototype expression
+static FunctionAST *ParseDefinition() {
+ getNextToken(); // eat def.
+ PrototypeAST *Proto = ParsePrototype();
+ if (Proto == 0)
+ return 0;
+
+ if (ExprAST *E = ParseExpression())
+ return new FunctionAST(Proto, E);
+ return 0;
+}
+
+/// toplevelexpr ::= expression
+static FunctionAST *ParseTopLevelExpr() {
+ SourceLocation FnLoc = CurLoc;
+ if (ExprAST *E = ParseExpression()) {
+ // Make an anonymous proto.
+ PrototypeAST *Proto =
+ new PrototypeAST(FnLoc, "main", std::vector<std::string>());
+ return new FunctionAST(Proto, E);
+ }
+ return 0;
+}
+
+/// external ::= 'extern' prototype
+static PrototypeAST *ParseExtern() {
+ getNextToken(); // eat extern.
+ return ParsePrototype();
+}
+
+//===----------------------------------------------------------------------===//
+// Debug Info Support
+//===----------------------------------------------------------------------===//
+
+static DIBuilder *DBuilder;
+
+DIType DebugInfo::getDoubleTy() {
+ if (DblTy.isValid())
+ return DblTy;
+
+ DblTy = DBuilder->createBasicType("double", 64, 64, dwarf::DW_ATE_float);
+ return DblTy;
+}
+
+void DebugInfo::emitLocation(ExprAST *AST) {
+ if (!AST)
+ return Builder.SetCurrentDebugLocation(DebugLoc());
+ DIScope *Scope;
+ if (LexicalBlocks.empty())
+ Scope = &TheCU;
+ else
+ Scope = LexicalBlocks.back();
+ Builder.SetCurrentDebugLocation(
+ DebugLoc::get(AST->getLine(), AST->getCol(), DIScope(*Scope)));
+}
+
+static DICompositeType CreateFunctionType(unsigned NumArgs, DIFile Unit) {
+ SmallVector<Value *, 8> EltTys;
+ DIType DblTy = KSDbgInfo.getDoubleTy();
+
+ // Add the result type.
+ EltTys.push_back(DblTy);
+
+ for (unsigned i = 0, e = NumArgs; i != e; ++i)
+ EltTys.push_back(DblTy);
+
+ DITypeArray EltTypeArray = DBuilder->getOrCreateTypeArray(EltTys);
+ return DBuilder->createSubroutineType(Unit, EltTypeArray);
+}
+
+//===----------------------------------------------------------------------===//
+// Code Generation
+//===----------------------------------------------------------------------===//
+
+static Module *TheModule;
+static std::map<std::string, AllocaInst *> NamedValues;
+static FunctionPassManager *TheFPM;
+
+Value *ErrorV(const char *Str) {
+ Error(Str);
+ return 0;
+}
+
+/// 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(getGlobalContext()), 0,
+ VarName.c_str());
+}
+
+Value *NumberExprAST::Codegen() {
+ KSDbgInfo.emitLocation(this);
+ return ConstantFP::get(getGlobalContext(), APFloat(Val));
+}
+
+Value *VariableExprAST::Codegen() {
+ // Look this variable up in the function.
+ Value *V = NamedValues[Name];
+ if (V == 0)
+ return ErrorV("Unknown variable name");
+
+ KSDbgInfo.emitLocation(this);
+ // Load the value.
+ return Builder.CreateLoad(V, Name.c_str());
+}
+
+Value *UnaryExprAST::Codegen() {
+ Value *OperandV = Operand->Codegen();
+ if (OperandV == 0)
+ return 0;
+
+ Function *F = TheModule->getFunction(std::string("unary") + Opcode);
+ if (F == 0)
+ return ErrorV("Unknown unary operator");
+
+ KSDbgInfo.emitLocation(this);
+ return Builder.CreateCall(F, OperandV, "unop");
+}
+
+Value *BinaryExprAST::Codegen() {
+ KSDbgInfo.emitLocation(this);
+
+ // 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);
+ if (!LHSE)
+ return ErrorV("destination of '=' must be a variable");
+ // Codegen the RHS.
+ Value *Val = RHS->Codegen();
+ if (Val == 0)
+ return 0;
+
+ // Look up the name.
+ Value *Variable = NamedValues[LHSE->getName()];
+ if (Variable == 0)
+ return ErrorV("Unknown variable name");
+
+ Builder.CreateStore(Val, Variable);
+ return Val;
+ }
+
+ Value *L = LHS->Codegen();
+ Value *R = RHS->Codegen();
+ if (L == 0 || R == 0)
+ return 0;
+
+ 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(getGlobalContext()),
+ "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 = TheModule->getFunction(std::string("binary") + Op);
+ assert(F && "binary operator not found!");
+
+ Value *Ops[] = { L, R };
+ return Builder.CreateCall(F, Ops, "binop");
+}
+
+Value *CallExprAST::Codegen() {
+ KSDbgInfo.emitLocation(this);
+
+ // Look up the name in the global module table.
+ Function *CalleeF = TheModule->getFunction(Callee);
+ if (CalleeF == 0)
+ return ErrorV("Unknown function referenced");
+
+ // If argument mismatch error.
+ if (CalleeF->arg_size() != Args.size())
+ return ErrorV("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() == 0)
+ return 0;
+ }
+
+ return Builder.CreateCall(CalleeF, ArgsV, "calltmp");
+}
+
+Value *IfExprAST::Codegen() {
+ KSDbgInfo.emitLocation(this);
+
+ Value *CondV = Cond->Codegen();
+ if (CondV == 0)
+ return 0;
+
+ // Convert condition to a bool by comparing equal to 0.0.
+ CondV = Builder.CreateFCmpONE(
+ CondV, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "ifcond");
+
+ 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(getGlobalContext(), "then", TheFunction);
+ BasicBlock *ElseBB = BasicBlock::Create(getGlobalContext(), "else");
+ BasicBlock *MergeBB = BasicBlock::Create(getGlobalContext(), "ifcont");
+
+ Builder.CreateCondBr(CondV, ThenBB, ElseBB);
+
+ // Emit then value.
+ Builder.SetInsertPoint(ThenBB);
+
+ Value *ThenV = Then->Codegen();
+ if (ThenV == 0)
+ return 0;
+
+ Builder.CreateBr(MergeBB);
+ // Codegen of 'Then' can change the current block, update ThenBB for the PHI.
+ ThenBB = Builder.GetInsertBlock();
+
+ // Emit else block.
+ TheFunction->getBasicBlockList().push_back(ElseBB);
+ Builder.SetInsertPoint(ElseBB);
+
+ Value *ElseV = Else->Codegen();
+ if (ElseV == 0)
+ return 0;
+
+ Builder.CreateBr(MergeBB);
+ // Codegen of 'Else' can change the current block, update ElseBB for the PHI.
+ ElseBB = Builder.GetInsertBlock();
+
+ // Emit merge block.
+ TheFunction->getBasicBlockList().push_back(MergeBB);
+ Builder.SetInsertPoint(MergeBB);
+ PHINode *PN =
+ Builder.CreatePHI(Type::getDoubleTy(getGlobalContext()), 2, "iftmp");
+
+ PN->addIncoming(ThenV, ThenBB);
+ PN->addIncoming(ElseV, ElseBB);
+ return PN;
+}
+
+Value *ForExprAST::Codegen() {
+ // 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:
+
+ Function *TheFunction = Builder.GetInsertBlock()->getParent();
+
+ // Create an alloca for the variable in the entry block.
+ AllocaInst *Alloca = CreateEntryBlockAlloca(TheFunction, VarName);
+
+ KSDbgInfo.emitLocation(this);
+
+ // Emit the start code first, without 'variable' in scope.
+ Value *StartVal = Start->Codegen();
+ if (StartVal == 0)
+ return 0;
+
+ // Store the value into the alloca.
+ Builder.CreateStore(StartVal, Alloca);
+
+ // Make the new basic block for the loop header, inserting after current
+ // block.
+ BasicBlock *LoopBB =
+ BasicBlock::Create(getGlobalContext(), "loop", TheFunction);
+
+ // Insert an explicit fall through from the current block to the LoopBB.
+ Builder.CreateBr(LoopBB);
+
+ // Start insertion in LoopBB.
+ Builder.SetInsertPoint(LoopBB);
+
+ // 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.
+ AllocaInst *OldVal = NamedValues[VarName];
+ NamedValues[VarName] = 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.
+ if (Body->Codegen() == 0)
+ return 0;
+
+ // Emit the step value.
+ Value *StepVal;
+ if (Step) {
+ StepVal = Step->Codegen();
+ if (StepVal == 0)
+ return 0;
+ } else {
+ // If not specified, use 1.0.
+ StepVal = ConstantFP::get(getGlobalContext(), APFloat(1.0));
+ }
+
+ // Compute the end condition.
+ Value *EndCond = End->Codegen();
+ if (EndCond == 0)
+ return EndCond;
+
+ // Reload, increment, and restore the alloca. This handles the case where
+ // the body of the loop mutates the variable.
+ Value *CurVar = Builder.CreateLoad(Alloca, VarName.c_str());
+ Value *NextVar = Builder.CreateFAdd(CurVar, StepVal, "nextvar");
+ Builder.CreateStore(NextVar, Alloca);
+
+ // Convert condition to a bool by comparing equal to 0.0.
+ EndCond = Builder.CreateFCmpONE(
+ EndCond, ConstantFP::get(getGlobalContext(), APFloat(0.0)), "loopcond");
+
+ // Create the "after loop" block and insert it.
+ BasicBlock *AfterBB =
+ BasicBlock::Create(getGlobalContext(), "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);
+
+ // Restore the unshadowed variable.
+ if (OldVal)
+ NamedValues[VarName] = OldVal;
+ else
+ NamedValues.erase(VarName);
+
+ // for expr always returns 0.0.
+ return Constant::getNullValue(Type::getDoubleTy(getGlobalContext()));
+}
+
+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;
+
+ // 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 == 0)
+ return 0;
+ } else { // If not specified, use 0.0.
+ InitVal = ConstantFP::get(getGlobalContext(), 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;
+ }
+
+ KSDbgInfo.emitLocation(this);
+
+ // Codegen the body, now that all vars are in scope.
+ Value *BodyVal = Body->Codegen();
+ if (BodyVal == 0)
+ return 0;
+
+ // 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;
+}
+
+Function *PrototypeAST::Codegen() {
+ // Make the function type: double(double,double) etc.
+ std::vector<Type *> Doubles(Args.size(),
+ Type::getDoubleTy(getGlobalContext()));
+ FunctionType *FT =
+ FunctionType::get(Type::getDoubleTy(getGlobalContext()), Doubles, false);
+
+ Function *F =
+ Function::Create(FT, Function::ExternalLinkage, Name, TheModule);
+
+ // If F conflicted, there was already something named 'Name'. If it has a
+ // body, don't allow redefinition or reextern.
+ if (F->getName() != Name) {
+ // Delete the one we just made and get the existing one.
+ F->eraseFromParent();
+ F = TheModule->getFunction(Name);
+
+ // If F already has a body, reject this.
+ if (!F->empty()) {
+ ErrorF("redefinition of function");
+ return 0;
+ }
+
+ // If F took a different number of args, reject.
+ if (F->arg_size() != Args.size()) {
+ ErrorF("redefinition of function with different # args");
+ return 0;
+ }
+ }
+
+ // Set names for all arguments.
+ unsigned Idx = 0;
+ for (Function::arg_iterator AI = F->arg_begin(); Idx != Args.size();
+ ++AI, ++Idx)
+ AI->setName(Args[Idx]);
+
+ // Create a subprogram DIE for this function.
+ DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
+ KSDbgInfo.TheCU.getDirectory());
+ DIDescriptor FContext(Unit);
+ unsigned LineNo = Line;
+ unsigned ScopeLine = Line;
+ DISubprogram SP = DBuilder->createFunction(
+ FContext, Name, StringRef(), Unit, LineNo,
+ CreateFunctionType(Args.size(), Unit), false /* internal linkage */,
+ true /* definition */, ScopeLine, DIDescriptor::FlagPrototyped, false, F);
+
+ KSDbgInfo.FnScopeMap[this] = SP;
+ return F;
+}
+
+/// CreateArgumentAllocas - Create an alloca for each argument and register the
+/// argument in the symbol table so that references to it will succeed.
+void PrototypeAST::CreateArgumentAllocas(Function *F) {
+ Function::arg_iterator AI = F->arg_begin();
+ for (unsigned Idx = 0, e = Args.size(); Idx != e; ++Idx, ++AI) {
+ // Create an alloca for this variable.
+ AllocaInst *Alloca = CreateEntryBlockAlloca(F, Args[Idx]);
+
+ // Create a debug descriptor for the variable.
+ DIScope *Scope = KSDbgInfo.LexicalBlocks.back();
+ DIFile Unit = DBuilder->createFile(KSDbgInfo.TheCU.getFilename(),
+ KSDbgInfo.TheCU.getDirectory());
+ DIVariable D = DBuilder->createLocalVariable(dwarf::DW_TAG_arg_variable,
+ *Scope, Args[Idx], Unit, Line,
+ KSDbgInfo.getDoubleTy(), Idx);
+
+ Instruction *Call = DBuilder->insertDeclare(
+ Alloca, D, DBuilder->createExpression(), Builder.GetInsertBlock());
+ Call->setDebugLoc(DebugLoc::get(Line, 0, *Scope));
+
+ // Store the initial value into the alloca.
+ Builder.CreateStore(AI, Alloca);
+
+ // Add arguments to variable symbol table.
+ NamedValues[Args[Idx]] = Alloca;
+ }
+}
+
+Function *FunctionAST::Codegen() {
+ NamedValues.clear();
+
+ Function *TheFunction = Proto->Codegen();
+ if (TheFunction == 0)
+ return 0;
+
+ // Push the current scope.
+ KSDbgInfo.LexicalBlocks.push_back(&KSDbgInfo.FnScopeMap[Proto]);
+
+ // 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);
+
+ // If this is an operator, install it.
+ if (Proto->isBinaryOp())
+ BinopPrecedence[Proto->getOperatorName()] = Proto->getBinaryPrecedence();
+
+ // Create a new basic block to start insertion into.
+ BasicBlock *BB = BasicBlock::Create(getGlobalContext(), "entry", TheFunction);
+ Builder.SetInsertPoint(BB);
+
+ // Add all arguments to the symbol table and create their allocas.
+ Proto->CreateArgumentAllocas(TheFunction);
+
+ KSDbgInfo.emitLocation(Body);
+
+ if (Value *RetVal = Body->Codegen()) {
+ // Finish off the function.
+ Builder.CreateRet(RetVal);
+
+ // Pop off the lexical block for the function.
+ KSDbgInfo.LexicalBlocks.pop_back();
+
+ // Validate the generated code, checking for consistency.
+ verifyFunction(*TheFunction);
+
+ // Optimize the function.
+ TheFPM->run(*TheFunction);
+
+ return TheFunction;
+ }
+
+ // Error reading body, remove function.
+ TheFunction->eraseFromParent();
+
+ if (Proto->isBinaryOp())
+ BinopPrecedence.erase(Proto->getOperatorName());
+
+ // Pop off the lexical block for the function since we added it
+ // unconditionally.
+ KSDbgInfo.LexicalBlocks.pop_back();
+
+ return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Top-Level parsing and JIT Driver
+//===----------------------------------------------------------------------===//
+
+static ExecutionEngine *TheExecutionEngine;
+
+static void HandleDefinition() {
+ if (FunctionAST *F = ParseDefinition()) {
+ if (!F->Codegen()) {
+ fprintf(stderr, "Error reading function definition:");
+ }
+ } else {
+ // Skip token for error recovery.
+ getNextToken();
+ }
+}
+
+static void HandleExtern() {
+ if (PrototypeAST *P = ParseExtern()) {
+ if (!P->Codegen()) {
+ fprintf(stderr, "Error reading extern");
+ }
+ } else {
+ // Skip token for error recovery.
+ getNextToken();
+ }
+}
+
+static void HandleTopLevelExpression() {
+ // Evaluate a top-level expression into an anonymous function.
+ if (FunctionAST *F = ParseTopLevelExpr()) {
+ if (!F->Codegen()) {
+ fprintf(stderr, "Error generating code for top level expr");
+ }
+ } else {
+ // Skip token for error recovery.
+ getNextToken();
+ }
+}
+
+/// top ::= definition | external | expression | ';'
+static void MainLoop() {
+ while (1) {
+ switch (CurTok) {
+ case tok_eof:
+ return;
+ case ';':
+ getNextToken();
+ break; // ignore top-level semicolons.
+ case tok_def:
+ HandleDefinition();
+ break;
+ case tok_extern:
+ HandleExtern();
+ break;
+ default:
+ HandleTopLevelExpression();
+ break;
+ }
+ }
+}
+
+//===----------------------------------------------------------------------===//
+// "Library" functions that can be "extern'd" from user code.
+//===----------------------------------------------------------------------===//
+
+/// putchard - putchar that takes a double and returns 0.
+extern "C" double putchard(double X) {
+ putchar((char)X);
+ return 0;
+}
+
+/// printd - printf that takes a double prints it as "%f\n", returning 0.
+extern "C" double printd(double X) {
+ printf("%f\n", X);
+ return 0;
+}
+
+//===----------------------------------------------------------------------===//
+// Main driver code.
+//===----------------------------------------------------------------------===//
+
+int main() {
+ InitializeNativeTarget();
+ InitializeNativeTargetAsmPrinter();
+ InitializeNativeTargetAsmParser();
+ LLVMContext &Context = getGlobalContext();
+
+ // Install standard binary operators.
+ // 1 is lowest precedence.
+ BinopPrecedence['='] = 2;
+ BinopPrecedence['<'] = 10;
+ BinopPrecedence['+'] = 20;
+ BinopPrecedence['-'] = 20;
+ BinopPrecedence['*'] = 40; // highest.
+
+ // Prime the first token.
+ getNextToken();
+
+ // Make the module, which holds all the code.
+ std::unique_ptr<Module> Owner = make_unique<Module>("my cool jit", Context);
+ TheModule = Owner.get();
+
+ // Add the current debug info version into the module.
+ TheModule->addModuleFlag(Module::Warning, "Debug Info Version",
+ DEBUG_METADATA_VERSION);
+
+ // Darwin only supports dwarf2.
+ if (Triple(sys::getProcessTriple()).isOSDarwin())
+ TheModule->addModuleFlag(llvm::Module::Warning, "Dwarf Version", 2);
+
+ // Construct the DIBuilder, we do this here because we need the module.
+ DBuilder = new DIBuilder(*TheModule);
+
+ // Create the compile unit for the module.
+ // Currently down as "fib.ks" as a filename since we're redirecting stdin
+ // but we'd like actual source locations.
+ KSDbgInfo.TheCU = DBuilder->createCompileUnit(
+ dwarf::DW_LANG_C, "fib.ks", ".", "Kaleidoscope Compiler", 0, "", 0);
+
+ // Create the JIT. This takes ownership of the module.
+ std::string ErrStr;
+ TheExecutionEngine = EngineBuilder(std::move(Owner))
+ .setErrorStr(&ErrStr)
+ .setMCJITMemoryManager(new SectionMemoryManager())
+ .create();
+ if (!TheExecutionEngine) {
+ fprintf(stderr, "Could not create ExecutionEngine: %s\n", ErrStr.c_str());
+ exit(1);
+ }
+
+ FunctionPassManager OurFPM(TheModule);
+
+ // Set up the optimizer pipeline. Start with registering info about how the
+ // target lays out data structures.
+ TheModule->setDataLayout(TheExecutionEngine->getDataLayout());
+ OurFPM.add(new DataLayoutPass());
+#if 0
+ // Provide basic AliasAnalysis support for GVN.
+ OurFPM.add(createBasicAliasAnalysisPass());
+ // Promote allocas to registers.
+ OurFPM.add(createPromoteMemoryToRegisterPass());
+ // Do simple "peephole" optimizations and bit-twiddling optzns.
+ OurFPM.add(createInstructionCombiningPass());
+ // Reassociate expressions.
+ OurFPM.add(createReassociatePass());
+ // Eliminate Common SubExpressions.
+ 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.
+ TheFPM = &OurFPM;
+
+ // Run the main "interpreter loop" now.
+ MainLoop();
+
+ TheFPM = 0;
+
+ // Finalize the debug info.
+ DBuilder->finalize();
+
+ // Print out all of the generated code.
+ TheModule->dump();
+
+ return 0;
+}
Modified: llvm/trunk/examples/Kaleidoscope/Makefile
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/examples/Kaleidoscope/Makefile?rev=223671&r1=223670&r2=223671&view=diff
==============================================================================
--- llvm/trunk/examples/Kaleidoscope/Makefile (original)
+++ llvm/trunk/examples/Kaleidoscope/Makefile Mon Dec 8 12:00:47 2014
@@ -10,6 +10,6 @@ LEVEL=../..
include $(LEVEL)/Makefile.config
-PARALLEL_DIRS:= Chapter2 Chapter3 Chapter4 Chapter5 Chapter6 Chapter7
+PARALLEL_DIRS:= Chapter2 Chapter3 Chapter4 Chapter5 Chapter6 Chapter7 Chapter8
include $(LEVEL)/Makefile.common
More information about the llvm-commits
mailing list