r184321 - [CodeGen] Move EHScopeStack into its own header
Reid Kleckner
reid at kleckner.net
Wed Jun 19 10:07:50 PDT 2013
Author: rnk
Date: Wed Jun 19 12:07:50 2013
New Revision: 184321
URL: http://llvm.org/viewvc/llvm-project?rev=184321&view=rev
Log:
[CodeGen] Move EHScopeStack into its own header
CGCleanup.h isn't meant to be included by all of CodeGen according to
John.
Added:
cfe/trunk/lib/CodeGen/EHScopeStack.h
- copied, changed from r184319, cfe/trunk/lib/CodeGen/CGCleanup.h
Modified:
cfe/trunk/lib/CodeGen/CGCleanup.h
cfe/trunk/lib/CodeGen/CodeGenFunction.h
Modified: cfe/trunk/lib/CodeGen/CGCleanup.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CGCleanup.h?rev=184321&r1=184320&r2=184321&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCleanup.h (original)
+++ cfe/trunk/lib/CodeGen/CGCleanup.h Wed Jun 19 12:07:50 2013
@@ -14,474 +14,20 @@
#ifndef CLANG_CODEGEN_CGCLEANUP_H
#define CLANG_CODEGEN_CGCLEANUP_H
-#include "clang/Basic/LLVM.h"
+#include "EHScopeStack.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
-#include "llvm/IR/BasicBlock.h"
-#include "llvm/IR/Value.h"
-#include "llvm/IR/Instructions.h"
+
+namespace llvm {
+class BasicBlock;
+class Value;
+class ConstantInt;
+class AllocaInst;
+}
namespace clang {
namespace CodeGen {
-class CodeGenFunction;
-
-/// A branch fixup. These are required when emitting a goto to a
-/// label which hasn't been emitted yet. The goto is optimistically
-/// emitted as a branch to the basic block for the label, and (if it
-/// occurs in a scope with non-trivial cleanups) a fixup is added to
-/// the innermost cleanup. When a (normal) cleanup is popped, any
-/// unresolved fixups in that scope are threaded through the cleanup.
-struct BranchFixup {
- /// The block containing the terminator which needs to be modified
- /// into a switch if this fixup is resolved into the current scope.
- /// If null, LatestBranch points directly to the destination.
- llvm::BasicBlock *OptimisticBranchBlock;
-
- /// The ultimate destination of the branch.
- ///
- /// This can be set to null to indicate that this fixup was
- /// successfully resolved.
- llvm::BasicBlock *Destination;
-
- /// The destination index value.
- unsigned DestinationIndex;
-
- /// The initial branch of the fixup.
- llvm::BranchInst *InitialBranch;
-};
-
-template <class T> struct InvariantValue {
- typedef T type;
- typedef T saved_type;
- static bool needsSaving(type value) { return false; }
- static saved_type save(CodeGenFunction &CGF, type value) { return value; }
- static type restore(CodeGenFunction &CGF, saved_type value) { return value; }
-};
-
-/// A metaprogramming class for ensuring that a value will dominate an
-/// arbitrary position in a function.
-template <class T> struct DominatingValue : InvariantValue<T> {};
-
-template <class T, bool mightBeInstruction =
- llvm::is_base_of<llvm::Value, T>::value &&
- !llvm::is_base_of<llvm::Constant, T>::value &&
- !llvm::is_base_of<llvm::BasicBlock, T>::value>
-struct DominatingPointer;
-template <class T> struct DominatingPointer<T,false> : InvariantValue<T*> {};
-// template <class T> struct DominatingPointer<T,true> at end of file
-
-template <class T> struct DominatingValue<T*> : DominatingPointer<T> {};
-
-enum CleanupKind {
- EHCleanup = 0x1,
- NormalCleanup = 0x2,
- NormalAndEHCleanup = EHCleanup | NormalCleanup,
-
- InactiveCleanup = 0x4,
- InactiveEHCleanup = EHCleanup | InactiveCleanup,
- InactiveNormalCleanup = NormalCleanup | InactiveCleanup,
- InactiveNormalAndEHCleanup = NormalAndEHCleanup | InactiveCleanup
-};
-
-/// A stack of scopes which respond to exceptions, including cleanups
-/// and catch blocks.
-class EHScopeStack {
-public:
- /// A saved depth on the scope stack. This is necessary because
- /// pushing scopes onto the stack invalidates iterators.
- class stable_iterator {
- friend class EHScopeStack;
-
- /// Offset from StartOfData to EndOfBuffer.
- ptrdiff_t Size;
-
- stable_iterator(ptrdiff_t Size) : Size(Size) {}
-
- public:
- static stable_iterator invalid() { return stable_iterator(-1); }
- stable_iterator() : Size(-1) {}
-
- bool isValid() const { return Size >= 0; }
-
- /// Returns true if this scope encloses I.
- /// Returns false if I is invalid.
- /// This scope must be valid.
- bool encloses(stable_iterator I) const { return Size <= I.Size; }
-
- /// Returns true if this scope strictly encloses I: that is,
- /// if it encloses I and is not I.
- /// Returns false is I is invalid.
- /// This scope must be valid.
- bool strictlyEncloses(stable_iterator I) const { return Size < I.Size; }
-
- friend bool operator==(stable_iterator A, stable_iterator B) {
- return A.Size == B.Size;
- }
- friend bool operator!=(stable_iterator A, stable_iterator B) {
- return A.Size != B.Size;
- }
- };
-
- /// Information for lazily generating a cleanup. Subclasses must be
- /// POD-like: cleanups will not be destructed, and they will be
- /// allocated on the cleanup stack and freely copied and moved
- /// around.
- ///
- /// Cleanup implementations should generally be declared in an
- /// anonymous namespace.
- class Cleanup {
- // Anchor the construction vtable.
- virtual void anchor();
- public:
- /// Generation flags.
- class Flags {
- enum {
- F_IsForEH = 0x1,
- F_IsNormalCleanupKind = 0x2,
- F_IsEHCleanupKind = 0x4
- };
- unsigned flags;
-
- public:
- Flags() : flags(0) {}
-
- /// isForEH - true if the current emission is for an EH cleanup.
- bool isForEHCleanup() const { return flags & F_IsForEH; }
- bool isForNormalCleanup() const { return !isForEHCleanup(); }
- void setIsForEHCleanup() { flags |= F_IsForEH; }
-
- bool isNormalCleanupKind() const { return flags & F_IsNormalCleanupKind; }
- void setIsNormalCleanupKind() { flags |= F_IsNormalCleanupKind; }
-
- /// isEHCleanupKind - true if the cleanup was pushed as an EH
- /// cleanup.
- bool isEHCleanupKind() const { return flags & F_IsEHCleanupKind; }
- void setIsEHCleanupKind() { flags |= F_IsEHCleanupKind; }
- };
-
- // Provide a virtual destructor to suppress a very common warning
- // that unfortunately cannot be suppressed without this. Cleanups
- // should not rely on this destructor ever being called.
- virtual ~Cleanup() {}
-
- /// Emit the cleanup. For normal cleanups, this is run in the
- /// same EH context as when the cleanup was pushed, i.e. the
- /// immediately-enclosing context of the cleanup scope. For
- /// EH cleanups, this is run in a terminate context.
- ///
- // \param flags cleanup kind.
- virtual void Emit(CodeGenFunction &CGF, Flags flags) = 0;
- };
-
- /// ConditionalCleanupN stores the saved form of its N parameters,
- /// then restores them and performs the cleanup.
- template <class T, class A0>
- class ConditionalCleanup1 : public Cleanup {
- typedef typename DominatingValue<A0>::saved_type A0_saved;
- A0_saved a0_saved;
-
- void Emit(CodeGenFunction &CGF, Flags flags) {
- A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
- T(a0).Emit(CGF, flags);
- }
-
- public:
- ConditionalCleanup1(A0_saved a0)
- : a0_saved(a0) {}
- };
-
- template <class T, class A0, class A1>
- class ConditionalCleanup2 : public Cleanup {
- typedef typename DominatingValue<A0>::saved_type A0_saved;
- typedef typename DominatingValue<A1>::saved_type A1_saved;
- A0_saved a0_saved;
- A1_saved a1_saved;
-
- void Emit(CodeGenFunction &CGF, Flags flags) {
- A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
- A1 a1 = DominatingValue<A1>::restore(CGF, a1_saved);
- T(a0, a1).Emit(CGF, flags);
- }
-
- public:
- ConditionalCleanup2(A0_saved a0, A1_saved a1)
- : a0_saved(a0), a1_saved(a1) {}
- };
-
- template <class T, class A0, class A1, class A2>
- class ConditionalCleanup3 : public Cleanup {
- typedef typename DominatingValue<A0>::saved_type A0_saved;
- typedef typename DominatingValue<A1>::saved_type A1_saved;
- typedef typename DominatingValue<A2>::saved_type A2_saved;
- A0_saved a0_saved;
- A1_saved a1_saved;
- A2_saved a2_saved;
-
- void Emit(CodeGenFunction &CGF, Flags flags) {
- A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
- A1 a1 = DominatingValue<A1>::restore(CGF, a1_saved);
- A2 a2 = DominatingValue<A2>::restore(CGF, a2_saved);
- T(a0, a1, a2).Emit(CGF, flags);
- }
-
- public:
- ConditionalCleanup3(A0_saved a0, A1_saved a1, A2_saved a2)
- : a0_saved(a0), a1_saved(a1), a2_saved(a2) {}
- };
-
- template <class T, class A0, class A1, class A2, class A3>
- class ConditionalCleanup4 : public Cleanup {
- typedef typename DominatingValue<A0>::saved_type A0_saved;
- typedef typename DominatingValue<A1>::saved_type A1_saved;
- typedef typename DominatingValue<A2>::saved_type A2_saved;
- typedef typename DominatingValue<A3>::saved_type A3_saved;
- A0_saved a0_saved;
- A1_saved a1_saved;
- A2_saved a2_saved;
- A3_saved a3_saved;
-
- void Emit(CodeGenFunction &CGF, Flags flags) {
- A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
- A1 a1 = DominatingValue<A1>::restore(CGF, a1_saved);
- A2 a2 = DominatingValue<A2>::restore(CGF, a2_saved);
- A3 a3 = DominatingValue<A3>::restore(CGF, a3_saved);
- T(a0, a1, a2, a3).Emit(CGF, flags);
- }
-
- public:
- ConditionalCleanup4(A0_saved a0, A1_saved a1, A2_saved a2, A3_saved a3)
- : a0_saved(a0), a1_saved(a1), a2_saved(a2), a3_saved(a3) {}
- };
-
-private:
- // The implementation for this class is in CGException.h and
- // CGException.cpp; the definition is here because it's used as a
- // member of CodeGenFunction.
-
- /// The start of the scope-stack buffer, i.e. the allocated pointer
- /// for the buffer. All of these pointers are either simultaneously
- /// null or simultaneously valid.
- char *StartOfBuffer;
-
- /// The end of the buffer.
- char *EndOfBuffer;
-
- /// The first valid entry in the buffer.
- char *StartOfData;
-
- /// The innermost normal cleanup on the stack.
- stable_iterator InnermostNormalCleanup;
-
- /// The innermost EH scope on the stack.
- stable_iterator InnermostEHScope;
-
- /// The current set of branch fixups. A branch fixup is a jump to
- /// an as-yet unemitted label, i.e. a label for which we don't yet
- /// know the EH stack depth. Whenever we pop a cleanup, we have
- /// to thread all the current branch fixups through it.
- ///
- /// Fixups are recorded as the Use of the respective branch or
- /// switch statement. The use points to the final destination.
- /// When popping out of a cleanup, these uses are threaded through
- /// the cleanup and adjusted to point to the new cleanup.
- ///
- /// Note that branches are allowed to jump into protected scopes
- /// in certain situations; e.g. the following code is legal:
- /// struct A { ~A(); }; // trivial ctor, non-trivial dtor
- /// goto foo;
- /// A a;
- /// foo:
- /// bar();
- SmallVector<BranchFixup, 8> BranchFixups;
-
- char *allocate(size_t Size);
-
- void *pushCleanup(CleanupKind K, size_t DataSize);
-
-public:
- EHScopeStack() : StartOfBuffer(0), EndOfBuffer(0), StartOfData(0),
- InnermostNormalCleanup(stable_end()),
- InnermostEHScope(stable_end()) {}
- ~EHScopeStack() { delete[] StartOfBuffer; }
-
- // Variadic templates would make this not terrible.
-
- /// Push a lazily-created cleanup on the stack.
- template <class T>
- void pushCleanup(CleanupKind Kind) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T();
- (void) Obj;
- }
-
- /// Push a lazily-created cleanup on the stack.
- template <class T, class A0>
- void pushCleanup(CleanupKind Kind, A0 a0) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T(a0);
- (void) Obj;
- }
-
- /// Push a lazily-created cleanup on the stack.
- template <class T, class A0, class A1>
- void pushCleanup(CleanupKind Kind, A0 a0, A1 a1) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T(a0, a1);
- (void) Obj;
- }
-
- /// Push a lazily-created cleanup on the stack.
- template <class T, class A0, class A1, class A2>
- void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T(a0, a1, a2);
- (void) Obj;
- }
-
- /// Push a lazily-created cleanup on the stack.
- template <class T, class A0, class A1, class A2, class A3>
- void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2, A3 a3) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T(a0, a1, a2, a3);
- (void) Obj;
- }
-
- /// Push a lazily-created cleanup on the stack.
- template <class T, class A0, class A1, class A2, class A3, class A4>
- void pushCleanup(CleanupKind Kind, A0 a0, A1 a1, A2 a2, A3 a3, A4 a4) {
- void *Buffer = pushCleanup(Kind, sizeof(T));
- Cleanup *Obj = new(Buffer) T(a0, a1, a2, a3, a4);
- (void) Obj;
- }
-
- // Feel free to add more variants of the following:
-
- /// Push a cleanup with non-constant storage requirements on the
- /// stack. The cleanup type must provide an additional static method:
- /// static size_t getExtraSize(size_t);
- /// The argument to this method will be the value N, which will also
- /// be passed as the first argument to the constructor.
- ///
- /// The data stored in the extra storage must obey the same
- /// restrictions as normal cleanup member data.
- ///
- /// The pointer returned from this method is valid until the cleanup
- /// stack is modified.
- template <class T, class A0, class A1, class A2>
- T *pushCleanupWithExtra(CleanupKind Kind, size_t N, A0 a0, A1 a1, A2 a2) {
- void *Buffer = pushCleanup(Kind, sizeof(T) + T::getExtraSize(N));
- return new (Buffer) T(N, a0, a1, a2);
- }
-
- void pushCopyOfCleanup(CleanupKind Kind, const void *Cleanup, size_t Size) {
- void *Buffer = pushCleanup(Kind, Size);
- std::memcpy(Buffer, Cleanup, Size);
- }
-
- /// Pops a cleanup scope off the stack. This is private to CGCleanup.cpp.
- void popCleanup();
-
- /// Push a set of catch handlers on the stack. The catch is
- /// uninitialized and will need to have the given number of handlers
- /// set on it.
- class EHCatchScope *pushCatch(unsigned NumHandlers);
-
- /// Pops a catch scope off the stack. This is private to CGException.cpp.
- void popCatch();
-
- /// Push an exceptions filter on the stack.
- class EHFilterScope *pushFilter(unsigned NumFilters);
-
- /// Pops an exceptions filter off the stack.
- void popFilter();
-
- /// Push a terminate handler on the stack.
- void pushTerminate();
-
- /// Pops a terminate handler off the stack.
- void popTerminate();
-
- /// Determines whether the exception-scopes stack is empty.
- bool empty() const { return StartOfData == EndOfBuffer; }
-
- bool requiresLandingPad() const {
- return InnermostEHScope != stable_end();
- }
-
- /// Determines whether there are any normal cleanups on the stack.
- bool hasNormalCleanups() const {
- return InnermostNormalCleanup != stable_end();
- }
-
- /// Returns the innermost normal cleanup on the stack, or
- /// stable_end() if there are no normal cleanups.
- stable_iterator getInnermostNormalCleanup() const {
- return InnermostNormalCleanup;
- }
- stable_iterator getInnermostActiveNormalCleanup() const;
-
- stable_iterator getInnermostEHScope() const {
- return InnermostEHScope;
- }
-
- stable_iterator getInnermostActiveEHScope() const;
-
- /// An unstable reference to a scope-stack depth. Invalidated by
- /// pushes but not pops.
- class iterator;
-
- /// Returns an iterator pointing to the innermost EH scope.
- iterator begin() const;
-
- /// Returns an iterator pointing to the outermost EH scope.
- iterator end() const;
-
- /// Create a stable reference to the top of the EH stack. The
- /// returned reference is valid until that scope is popped off the
- /// stack.
- stable_iterator stable_begin() const {
- return stable_iterator(EndOfBuffer - StartOfData);
- }
-
- /// Create a stable reference to the bottom of the EH stack.
- static stable_iterator stable_end() {
- return stable_iterator(0);
- }
-
- /// Translates an iterator into a stable_iterator.
- stable_iterator stabilize(iterator it) const;
-
- /// Turn a stable reference to a scope depth into a unstable pointer
- /// to the EH stack.
- iterator find(stable_iterator save) const;
-
- /// Removes the cleanup pointed to by the given stable_iterator.
- void removeCleanup(stable_iterator save);
-
- /// Add a branch fixup to the current cleanup scope.
- BranchFixup &addBranchFixup() {
- assert(hasNormalCleanups() && "adding fixup in scope without cleanups");
- BranchFixups.push_back(BranchFixup());
- return BranchFixups.back();
- }
-
- unsigned getNumBranchFixups() const { return BranchFixups.size(); }
- BranchFixup &getBranchFixup(unsigned I) {
- assert(I < getNumBranchFixups());
- return BranchFixups[I];
- }
-
- /// Pops lazily-removed fixups from the end of the list. This
- /// should only be called by procedures which have just popped a
- /// cleanup or resolved one or more fixups.
- void popNullFixups();
-
- /// Clears the branch-fixups list. This should only be called by
- /// ResolveAllBranchFixups.
- void clearFixups() { BranchFixups.clear(); }
-};
-
/// A protected scope for zero-cost EH handling.
class EHScope {
llvm::BasicBlock *CachedLandingPad;
Modified: cfe/trunk/lib/CodeGen/CodeGenFunction.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenFunction.h?rev=184321&r1=184320&r2=184321&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenFunction.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenFunction.h Wed Jun 19 12:07:50 2013
@@ -15,9 +15,9 @@
#define CLANG_CODEGEN_CODEGENFUNCTION_H
#include "CGBuilder.h"
-#include "CGCleanup.h"
#include "CGDebugInfo.h"
#include "CGValue.h"
+#include "EHScopeStack.h"
#include "CodeGenModule.h"
#include "clang/AST/CharUnits.h"
#include "clang/AST/ExprCXX.h"
Copied: cfe/trunk/lib/CodeGen/EHScopeStack.h (from r184319, cfe/trunk/lib/CodeGen/CGCleanup.h)
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/EHScopeStack.h?p2=cfe/trunk/lib/CodeGen/EHScopeStack.h&p1=cfe/trunk/lib/CodeGen/CGCleanup.h&r1=184319&r2=184321&rev=184321&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CGCleanup.h (original)
+++ cfe/trunk/lib/CodeGen/EHScopeStack.h Wed Jun 19 12:07:50 2013
@@ -1,4 +1,4 @@
-//===-- CGCleanup.h - Classes for cleanups IR generation --------*- C++ -*-===//
+//===-- EHScopeStack.h - Stack for cleanup IR generation --------*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
@@ -7,15 +7,16 @@
//
//===----------------------------------------------------------------------===//
//
-// These classes support the generation of LLVM IR for cleanups.
+// These classes should be the minimum interface required for other parts of
+// CodeGen to emit cleanups. The implementation is in CGCleanup.cpp and other
+// implemenentation details that are not widely needed are in CGCleanup.h.
//
//===----------------------------------------------------------------------===//
-#ifndef CLANG_CODEGEN_CGCLEANUP_H
-#define CLANG_CODEGEN_CGCLEANUP_H
+#ifndef CLANG_CODEGEN_EHSCOPESTACK_H
+#define CLANG_CODEGEN_EHSCOPESTACK_H
#include "clang/Basic/LLVM.h"
-#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/SmallVector.h"
#include "llvm/IR/BasicBlock.h"
#include "llvm/IR/Value.h"
@@ -217,14 +218,14 @@ public:
A0_saved a0_saved;
A1_saved a1_saved;
A2_saved a2_saved;
-
+
void Emit(CodeGenFunction &CGF, Flags flags) {
A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
A1 a1 = DominatingValue<A1>::restore(CGF, a1_saved);
A2 a2 = DominatingValue<A2>::restore(CGF, a2_saved);
T(a0, a1, a2).Emit(CGF, flags);
}
-
+
public:
ConditionalCleanup3(A0_saved a0, A1_saved a1, A2_saved a2)
: a0_saved(a0), a1_saved(a1), a2_saved(a2) {}
@@ -240,7 +241,7 @@ public:
A1_saved a1_saved;
A2_saved a2_saved;
A3_saved a3_saved;
-
+
void Emit(CodeGenFunction &CGF, Flags flags) {
A0 a0 = DominatingValue<A0>::restore(CGF, a0_saved);
A1 a1 = DominatingValue<A1>::restore(CGF, a1_saved);
@@ -248,7 +249,7 @@ public:
A3 a3 = DominatingValue<A3>::restore(CGF, a3_saved);
T(a0, a1, a2, a3).Emit(CGF, flags);
}
-
+
public:
ConditionalCleanup4(A0_saved a0, A1_saved a1, A2_saved a2, A3_saved a3)
: a0_saved(a0), a1_saved(a1), a2_saved(a2), a3_saved(a3) {}
@@ -482,514 +483,7 @@ public:
void clearFixups() { BranchFixups.clear(); }
};
-/// A protected scope for zero-cost EH handling.
-class EHScope {
- llvm::BasicBlock *CachedLandingPad;
- llvm::BasicBlock *CachedEHDispatchBlock;
-
- EHScopeStack::stable_iterator EnclosingEHScope;
-
- class CommonBitFields {
- friend class EHScope;
- unsigned Kind : 2;
- };
- enum { NumCommonBits = 2 };
-
-protected:
- class CatchBitFields {
- friend class EHCatchScope;
- unsigned : NumCommonBits;
-
- unsigned NumHandlers : 32 - NumCommonBits;
- };
-
- class CleanupBitFields {
- friend class EHCleanupScope;
- unsigned : NumCommonBits;
-
- /// Whether this cleanup needs to be run along normal edges.
- unsigned IsNormalCleanup : 1;
-
- /// Whether this cleanup needs to be run along exception edges.
- unsigned IsEHCleanup : 1;
-
- /// Whether this cleanup is currently active.
- unsigned IsActive : 1;
-
- /// Whether the normal cleanup should test the activation flag.
- unsigned TestFlagInNormalCleanup : 1;
-
- /// Whether the EH cleanup should test the activation flag.
- unsigned TestFlagInEHCleanup : 1;
-
- /// The amount of extra storage needed by the Cleanup.
- /// Always a multiple of the scope-stack alignment.
- unsigned CleanupSize : 12;
-
- /// The number of fixups required by enclosing scopes (not including
- /// this one). If this is the top cleanup scope, all the fixups
- /// from this index onwards belong to this scope.
- unsigned FixupDepth : 32 - 17 - NumCommonBits; // currently 13
- };
-
- class FilterBitFields {
- friend class EHFilterScope;
- unsigned : NumCommonBits;
-
- unsigned NumFilters : 32 - NumCommonBits;
- };
-
- union {
- CommonBitFields CommonBits;
- CatchBitFields CatchBits;
- CleanupBitFields CleanupBits;
- FilterBitFields FilterBits;
- };
-
-public:
- enum Kind { Cleanup, Catch, Terminate, Filter };
-
- EHScope(Kind kind, EHScopeStack::stable_iterator enclosingEHScope)
- : CachedLandingPad(0), CachedEHDispatchBlock(0),
- EnclosingEHScope(enclosingEHScope) {
- CommonBits.Kind = kind;
- }
-
- Kind getKind() const { return static_cast<Kind>(CommonBits.Kind); }
-
- llvm::BasicBlock *getCachedLandingPad() const {
- return CachedLandingPad;
- }
-
- void setCachedLandingPad(llvm::BasicBlock *block) {
- CachedLandingPad = block;
- }
-
- llvm::BasicBlock *getCachedEHDispatchBlock() const {
- return CachedEHDispatchBlock;
- }
-
- void setCachedEHDispatchBlock(llvm::BasicBlock *block) {
- CachedEHDispatchBlock = block;
- }
-
- bool hasEHBranches() const {
- if (llvm::BasicBlock *block = getCachedEHDispatchBlock())
- return !block->use_empty();
- return false;
- }
-
- EHScopeStack::stable_iterator getEnclosingEHScope() const {
- return EnclosingEHScope;
- }
-};
-
-/// A scope which attempts to handle some, possibly all, types of
-/// exceptions.
-///
-/// Objective C \@finally blocks are represented using a cleanup scope
-/// after the catch scope.
-class EHCatchScope : public EHScope {
- // In effect, we have a flexible array member
- // Handler Handlers[0];
- // But that's only standard in C99, not C++, so we have to do
- // annoying pointer arithmetic instead.
-
-public:
- struct Handler {
- /// A type info value, or null (C++ null, not an LLVM null pointer)
- /// for a catch-all.
- llvm::Value *Type;
-
- /// The catch handler for this type.
- llvm::BasicBlock *Block;
-
- bool isCatchAll() const { return Type == 0; }
- };
-
-private:
- friend class EHScopeStack;
-
- Handler *getHandlers() {
- return reinterpret_cast<Handler*>(this+1);
- }
-
- const Handler *getHandlers() const {
- return reinterpret_cast<const Handler*>(this+1);
- }
-
-public:
- static size_t getSizeForNumHandlers(unsigned N) {
- return sizeof(EHCatchScope) + N * sizeof(Handler);
- }
-
- EHCatchScope(unsigned numHandlers,
- EHScopeStack::stable_iterator enclosingEHScope)
- : EHScope(Catch, enclosingEHScope) {
- CatchBits.NumHandlers = numHandlers;
- }
-
- unsigned getNumHandlers() const {
- return CatchBits.NumHandlers;
- }
-
- void setCatchAllHandler(unsigned I, llvm::BasicBlock *Block) {
- setHandler(I, /*catchall*/ 0, Block);
- }
-
- void setHandler(unsigned I, llvm::Value *Type, llvm::BasicBlock *Block) {
- assert(I < getNumHandlers());
- getHandlers()[I].Type = Type;
- getHandlers()[I].Block = Block;
- }
-
- const Handler &getHandler(unsigned I) const {
- assert(I < getNumHandlers());
- return getHandlers()[I];
- }
-
- typedef const Handler *iterator;
- iterator begin() const { return getHandlers(); }
- iterator end() const { return getHandlers() + getNumHandlers(); }
-
- static bool classof(const EHScope *Scope) {
- return Scope->getKind() == Catch;
- }
-};
-
-/// A cleanup scope which generates the cleanup blocks lazily.
-class EHCleanupScope : public EHScope {
- /// The nearest normal cleanup scope enclosing this one.
- EHScopeStack::stable_iterator EnclosingNormal;
-
- /// The nearest EH scope enclosing this one.
- EHScopeStack::stable_iterator EnclosingEH;
-
- /// The dual entry/exit block along the normal edge. This is lazily
- /// created if needed before the cleanup is popped.
- llvm::BasicBlock *NormalBlock;
-
- /// An optional i1 variable indicating whether this cleanup has been
- /// activated yet.
- llvm::AllocaInst *ActiveFlag;
-
- /// Extra information required for cleanups that have resolved
- /// branches through them. This has to be allocated on the side
- /// because everything on the cleanup stack has be trivially
- /// movable.
- struct ExtInfo {
- /// The destinations of normal branch-afters and branch-throughs.
- llvm::SmallPtrSet<llvm::BasicBlock*, 4> Branches;
-
- /// Normal branch-afters.
- SmallVector<std::pair<llvm::BasicBlock*,llvm::ConstantInt*>, 4>
- BranchAfters;
- };
- mutable struct ExtInfo *ExtInfo;
-
- struct ExtInfo &getExtInfo() {
- if (!ExtInfo) ExtInfo = new struct ExtInfo();
- return *ExtInfo;
- }
-
- const struct ExtInfo &getExtInfo() const {
- if (!ExtInfo) ExtInfo = new struct ExtInfo();
- return *ExtInfo;
- }
-
-public:
- /// Gets the size required for a lazy cleanup scope with the given
- /// cleanup-data requirements.
- static size_t getSizeForCleanupSize(size_t Size) {
- return sizeof(EHCleanupScope) + Size;
- }
-
- size_t getAllocatedSize() const {
- return sizeof(EHCleanupScope) + CleanupBits.CleanupSize;
- }
-
- EHCleanupScope(bool isNormal, bool isEH, bool isActive,
- unsigned cleanupSize, unsigned fixupDepth,
- EHScopeStack::stable_iterator enclosingNormal,
- EHScopeStack::stable_iterator enclosingEH)
- : EHScope(EHScope::Cleanup, enclosingEH), EnclosingNormal(enclosingNormal),
- NormalBlock(0), ActiveFlag(0), ExtInfo(0) {
- CleanupBits.IsNormalCleanup = isNormal;
- CleanupBits.IsEHCleanup = isEH;
- CleanupBits.IsActive = isActive;
- CleanupBits.TestFlagInNormalCleanup = false;
- CleanupBits.TestFlagInEHCleanup = false;
- CleanupBits.CleanupSize = cleanupSize;
- CleanupBits.FixupDepth = fixupDepth;
-
- assert(CleanupBits.CleanupSize == cleanupSize && "cleanup size overflow");
- }
-
- ~EHCleanupScope() {
- delete ExtInfo;
- }
-
- bool isNormalCleanup() const { return CleanupBits.IsNormalCleanup; }
- llvm::BasicBlock *getNormalBlock() const { return NormalBlock; }
- void setNormalBlock(llvm::BasicBlock *BB) { NormalBlock = BB; }
-
- bool isEHCleanup() const { return CleanupBits.IsEHCleanup; }
- llvm::BasicBlock *getEHBlock() const { return getCachedEHDispatchBlock(); }
- void setEHBlock(llvm::BasicBlock *BB) { setCachedEHDispatchBlock(BB); }
-
- bool isActive() const { return CleanupBits.IsActive; }
- void setActive(bool A) { CleanupBits.IsActive = A; }
-
- llvm::AllocaInst *getActiveFlag() const { return ActiveFlag; }
- void setActiveFlag(llvm::AllocaInst *Var) { ActiveFlag = Var; }
-
- void setTestFlagInNormalCleanup() {
- CleanupBits.TestFlagInNormalCleanup = true;
- }
- bool shouldTestFlagInNormalCleanup() const {
- return CleanupBits.TestFlagInNormalCleanup;
- }
-
- void setTestFlagInEHCleanup() {
- CleanupBits.TestFlagInEHCleanup = true;
- }
- bool shouldTestFlagInEHCleanup() const {
- return CleanupBits.TestFlagInEHCleanup;
- }
-
- unsigned getFixupDepth() const { return CleanupBits.FixupDepth; }
- EHScopeStack::stable_iterator getEnclosingNormalCleanup() const {
- return EnclosingNormal;
- }
-
- size_t getCleanupSize() const { return CleanupBits.CleanupSize; }
- void *getCleanupBuffer() { return this + 1; }
-
- EHScopeStack::Cleanup *getCleanup() {
- return reinterpret_cast<EHScopeStack::Cleanup*>(getCleanupBuffer());
- }
-
- /// True if this cleanup scope has any branch-afters or branch-throughs.
- bool hasBranches() const { return ExtInfo && !ExtInfo->Branches.empty(); }
-
- /// Add a branch-after to this cleanup scope. A branch-after is a
- /// branch from a point protected by this (normal) cleanup to a
- /// point in the normal cleanup scope immediately containing it.
- /// For example,
- /// for (;;) { A a; break; }
- /// contains a branch-after.
- ///
- /// Branch-afters each have their own destination out of the
- /// cleanup, guaranteed distinct from anything else threaded through
- /// it. Therefore branch-afters usually force a switch after the
- /// cleanup.
- void addBranchAfter(llvm::ConstantInt *Index,
- llvm::BasicBlock *Block) {
- struct ExtInfo &ExtInfo = getExtInfo();
- if (ExtInfo.Branches.insert(Block))
- ExtInfo.BranchAfters.push_back(std::make_pair(Block, Index));
- }
-
- /// Return the number of unique branch-afters on this scope.
- unsigned getNumBranchAfters() const {
- return ExtInfo ? ExtInfo->BranchAfters.size() : 0;
- }
-
- llvm::BasicBlock *getBranchAfterBlock(unsigned I) const {
- assert(I < getNumBranchAfters());
- return ExtInfo->BranchAfters[I].first;
- }
-
- llvm::ConstantInt *getBranchAfterIndex(unsigned I) const {
- assert(I < getNumBranchAfters());
- return ExtInfo->BranchAfters[I].second;
- }
-
- /// Add a branch-through to this cleanup scope. A branch-through is
- /// a branch from a scope protected by this (normal) cleanup to an
- /// enclosing scope other than the immediately-enclosing normal
- /// cleanup scope.
- ///
- /// In the following example, the branch through B's scope is a
- /// branch-through, while the branch through A's scope is a
- /// branch-after:
- /// for (;;) { A a; B b; break; }
- ///
- /// All branch-throughs have a common destination out of the
- /// cleanup, one possibly shared with the fall-through. Therefore
- /// branch-throughs usually don't force a switch after the cleanup.
- ///
- /// \return true if the branch-through was new to this scope
- bool addBranchThrough(llvm::BasicBlock *Block) {
- return getExtInfo().Branches.insert(Block);
- }
-
- /// Determines if this cleanup scope has any branch throughs.
- bool hasBranchThroughs() const {
- if (!ExtInfo) return false;
- return (ExtInfo->BranchAfters.size() != ExtInfo->Branches.size());
- }
-
- static bool classof(const EHScope *Scope) {
- return (Scope->getKind() == Cleanup);
- }
-};
-
-/// An exceptions scope which filters exceptions thrown through it.
-/// Only exceptions matching the filter types will be permitted to be
-/// thrown.
-///
-/// This is used to implement C++ exception specifications.
-class EHFilterScope : public EHScope {
- // Essentially ends in a flexible array member:
- // llvm::Value *FilterTypes[0];
-
- llvm::Value **getFilters() {
- return reinterpret_cast<llvm::Value**>(this+1);
- }
-
- llvm::Value * const *getFilters() const {
- return reinterpret_cast<llvm::Value* const *>(this+1);
- }
-
-public:
- EHFilterScope(unsigned numFilters)
- : EHScope(Filter, EHScopeStack::stable_end()) {
- FilterBits.NumFilters = numFilters;
- }
-
- static size_t getSizeForNumFilters(unsigned numFilters) {
- return sizeof(EHFilterScope) + numFilters * sizeof(llvm::Value*);
- }
-
- unsigned getNumFilters() const { return FilterBits.NumFilters; }
-
- void setFilter(unsigned i, llvm::Value *filterValue) {
- assert(i < getNumFilters());
- getFilters()[i] = filterValue;
- }
-
- llvm::Value *getFilter(unsigned i) const {
- assert(i < getNumFilters());
- return getFilters()[i];
- }
-
- static bool classof(const EHScope *scope) {
- return scope->getKind() == Filter;
- }
-};
-
-/// An exceptions scope which calls std::terminate if any exception
-/// reaches it.
-class EHTerminateScope : public EHScope {
-public:
- EHTerminateScope(EHScopeStack::stable_iterator enclosingEHScope)
- : EHScope(Terminate, enclosingEHScope) {}
- static size_t getSize() { return sizeof(EHTerminateScope); }
-
- static bool classof(const EHScope *scope) {
- return scope->getKind() == Terminate;
- }
-};
-
-/// A non-stable pointer into the scope stack.
-class EHScopeStack::iterator {
- char *Ptr;
-
- friend class EHScopeStack;
- explicit iterator(char *Ptr) : Ptr(Ptr) {}
-
-public:
- iterator() : Ptr(0) {}
-
- EHScope *get() const {
- return reinterpret_cast<EHScope*>(Ptr);
- }
-
- EHScope *operator->() const { return get(); }
- EHScope &operator*() const { return *get(); }
-
- iterator &operator++() {
- switch (get()->getKind()) {
- case EHScope::Catch:
- Ptr += EHCatchScope::getSizeForNumHandlers(
- static_cast<const EHCatchScope*>(get())->getNumHandlers());
- break;
-
- case EHScope::Filter:
- Ptr += EHFilterScope::getSizeForNumFilters(
- static_cast<const EHFilterScope*>(get())->getNumFilters());
- break;
-
- case EHScope::Cleanup:
- Ptr += static_cast<const EHCleanupScope*>(get())
- ->getAllocatedSize();
- break;
-
- case EHScope::Terminate:
- Ptr += EHTerminateScope::getSize();
- break;
- }
-
- return *this;
- }
-
- iterator next() {
- iterator copy = *this;
- ++copy;
- return copy;
- }
-
- iterator operator++(int) {
- iterator copy = *this;
- operator++();
- return copy;
- }
-
- bool encloses(iterator other) const { return Ptr >= other.Ptr; }
- bool strictlyEncloses(iterator other) const { return Ptr > other.Ptr; }
-
- bool operator==(iterator other) const { return Ptr == other.Ptr; }
- bool operator!=(iterator other) const { return Ptr != other.Ptr; }
-};
-
-inline EHScopeStack::iterator EHScopeStack::begin() const {
- return iterator(StartOfData);
-}
-
-inline EHScopeStack::iterator EHScopeStack::end() const {
- return iterator(EndOfBuffer);
-}
-
-inline void EHScopeStack::popCatch() {
- assert(!empty() && "popping exception stack when not empty");
-
- EHCatchScope &scope = cast<EHCatchScope>(*begin());
- InnermostEHScope = scope.getEnclosingEHScope();
- StartOfData += EHCatchScope::getSizeForNumHandlers(scope.getNumHandlers());
-}
-
-inline void EHScopeStack::popTerminate() {
- assert(!empty() && "popping exception stack when not empty");
-
- EHTerminateScope &scope = cast<EHTerminateScope>(*begin());
- InnermostEHScope = scope.getEnclosingEHScope();
- StartOfData += EHTerminateScope::getSize();
-}
-
-inline EHScopeStack::iterator EHScopeStack::find(stable_iterator sp) const {
- assert(sp.isValid() && "finding invalid savepoint");
- assert(sp.Size <= stable_begin().Size && "finding savepoint after pop");
- return iterator(EndOfBuffer - sp.Size);
-}
-
-inline EHScopeStack::stable_iterator
-EHScopeStack::stabilize(iterator ir) const {
- assert(StartOfData <= ir.Ptr && ir.Ptr <= EndOfBuffer);
- return stable_iterator(EndOfBuffer - ir.Ptr);
-}
-
-}
-}
+} // namespace CodeGen
+} // namespace clang
#endif
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