llvm-6502/include/llvm/Analysis/MemoryBuiltins.h
Bill Wendling 167ede898a Reverting r171325 & r172363. This was causing a mis-compile on the self-hosted LTO build bots.
Okay, here's how to reproduce the problem:

1) Build a Release (or Release+Asserts) version of clang in the normal way.

2) Using the clang & clang++ binaries from (1), build a Release (or
   Release+Asserts) version of the same sources, but this time enable LTO ---
   specify the `-flto' flag on the command line.

3) Run the ARC migrator tests:

    $ arcmt-test --args -triple x86_64-apple-darwin10 -fsyntax-only -x objective-c++ ./src/tools/clang/test/ARCMT/cxx-rewrite.mm

You'll see that the output isn't correct (the whitespace is off).

The mis-compile is in the function `RewriteBuffer::RemoveText' in the
clang/lib/Rewrite/Core/Rewriter.cpp file. When that function and RewriteRope.cpp
are compiled with LTO and the `arcmt-test' executable is regenerated, you'll see
the error. When those files are not LTO'ed, then the output of the `arcmt-test'
is fine.

It is *really* hard to get a testcase out of this. I'll file a PR with what I
have currently.

--- Reverse-merging r172363 into '.':
U    include/llvm/Analysis/MemoryBuiltins.h
U    lib/Analysis/MemoryBuiltins.cpp

--- Reverse-merging r171325 into '.':
U    test/Transforms/InstCombine/objsize.ll
G    include/llvm/Analysis/MemoryBuiltins.h
G    lib/Analysis/MemoryBuiltins.cpp




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172756 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-17 21:28:46 +00:00

267 lines
9.8 KiB
C++

//===- llvm/Analysis/MemoryBuiltins.h- Calls to memory builtins -*- C++ -*-===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This family of functions identifies calls to builtin functions that allocate
// or free memory.
//
//===----------------------------------------------------------------------===//
#ifndef LLVM_ANALYSIS_MEMORYBUILTINS_H
#define LLVM_ANALYSIS_MEMORYBUILTINS_H
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/Operator.h"
#include "llvm/InstVisitor.h"
#include "llvm/Support/DataTypes.h"
#include "llvm/Support/TargetFolder.h"
#include "llvm/Support/ValueHandle.h"
namespace llvm {
class CallInst;
class PointerType;
class DataLayout;
class TargetLibraryInfo;
class Type;
class Value;
/// \brief Tests if a value is a call or invoke to a library function that
/// allocates or reallocates memory (either malloc, calloc, realloc, or strdup
/// like).
bool isAllocationFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
/// \brief Tests if a value is a call or invoke to a function that returns a
/// NoAlias pointer (including malloc/calloc/realloc/strdup-like functions).
bool isNoAliasFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
/// \brief Tests if a value is a call or invoke to a library function that
/// allocates uninitialized memory (such as malloc).
bool isMallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
/// \brief Tests if a value is a call or invoke to a library function that
/// allocates zero-filled memory (such as calloc).
bool isCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
/// \brief Tests if a value is a call or invoke to a library function that
/// allocates memory (either malloc, calloc, or strdup like).
bool isAllocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
/// \brief Tests if a value is a call or invoke to a library function that
/// reallocates memory (such as realloc).
bool isReallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
//===----------------------------------------------------------------------===//
// malloc Call Utility Functions.
//
/// extractMallocCall - Returns the corresponding CallInst if the instruction
/// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we
/// ignore InvokeInst here.
const CallInst *extractMallocCall(const Value *I, const TargetLibraryInfo *TLI);
static inline CallInst *extractMallocCall(Value *I,
const TargetLibraryInfo *TLI) {
return const_cast<CallInst*>(extractMallocCall((const Value*)I, TLI));
}
/// isArrayMalloc - Returns the corresponding CallInst if the instruction
/// is a call to malloc whose array size can be determined and the array size
/// is not constant 1. Otherwise, return NULL.
const CallInst *isArrayMalloc(const Value *I, const DataLayout *TD,
const TargetLibraryInfo *TLI);
/// getMallocType - Returns the PointerType resulting from the malloc call.
/// The PointerType depends on the number of bitcast uses of the malloc call:
/// 0: PointerType is the malloc calls' return type.
/// 1: PointerType is the bitcast's result type.
/// >1: Unique PointerType cannot be determined, return NULL.
PointerType *getMallocType(const CallInst *CI, const TargetLibraryInfo *TLI);
/// getMallocAllocatedType - Returns the Type allocated by malloc call.
/// The Type depends on the number of bitcast uses of the malloc call:
/// 0: PointerType is the malloc calls' return type.
/// 1: PointerType is the bitcast's result type.
/// >1: Unique PointerType cannot be determined, return NULL.
Type *getMallocAllocatedType(const CallInst *CI, const TargetLibraryInfo *TLI);
/// getMallocArraySize - Returns the array size of a malloc call. If the
/// argument passed to malloc is a multiple of the size of the malloced type,
/// then return that multiple. For non-array mallocs, the multiple is
/// constant 1. Otherwise, return NULL for mallocs whose array size cannot be
/// determined.
Value *getMallocArraySize(CallInst *CI, const DataLayout *TD,
const TargetLibraryInfo *TLI,
bool LookThroughSExt = false);
//===----------------------------------------------------------------------===//
// calloc Call Utility Functions.
//
/// extractCallocCall - Returns the corresponding CallInst if the instruction
/// is a calloc call.
const CallInst *extractCallocCall(const Value *I, const TargetLibraryInfo *TLI);
static inline CallInst *extractCallocCall(Value *I,
const TargetLibraryInfo *TLI) {
return const_cast<CallInst*>(extractCallocCall((const Value*)I, TLI));
}
//===----------------------------------------------------------------------===//
// free Call Utility Functions.
//
/// isFreeCall - Returns non-null if the value is a call to the builtin free()
const CallInst *isFreeCall(const Value *I, const TargetLibraryInfo *TLI);
static inline CallInst *isFreeCall(Value *I, const TargetLibraryInfo *TLI) {
return const_cast<CallInst*>(isFreeCall((const Value*)I, TLI));
}
//===----------------------------------------------------------------------===//
// Utility functions to compute size of objects.
//
/// \brief Compute the size of the object pointed by Ptr. Returns true and the
/// object size in Size if successful, and false otherwise.
/// If RoundToAlign is true, then Size is rounded up to the aligment of allocas,
/// byval arguments, and global variables.
bool getObjectSize(const Value *Ptr, uint64_t &Size, const DataLayout *TD,
const TargetLibraryInfo *TLI, bool RoundToAlign = false);
typedef std::pair<APInt, APInt> SizeOffsetType;
/// \brief Evaluate the size and offset of an object ponted by a Value*
/// statically. Fails if size or offset are not known at compile time.
class ObjectSizeOffsetVisitor
: public InstVisitor<ObjectSizeOffsetVisitor, SizeOffsetType> {
const DataLayout *TD;
const TargetLibraryInfo *TLI;
bool RoundToAlign;
unsigned IntTyBits;
APInt Zero;
SmallPtrSet<Instruction *, 8> SeenInsts;
APInt align(APInt Size, uint64_t Align);
SizeOffsetType unknown() {
return std::make_pair(APInt(), APInt());
}
public:
ObjectSizeOffsetVisitor(const DataLayout *TD, const TargetLibraryInfo *TLI,
LLVMContext &Context, bool RoundToAlign = false);
SizeOffsetType compute(Value *V);
bool knownSize(SizeOffsetType &SizeOffset) {
return SizeOffset.first.getBitWidth() > 1;
}
bool knownOffset(SizeOffsetType &SizeOffset) {
return SizeOffset.second.getBitWidth() > 1;
}
bool bothKnown(SizeOffsetType &SizeOffset) {
return knownSize(SizeOffset) && knownOffset(SizeOffset);
}
SizeOffsetType visitAllocaInst(AllocaInst &I);
SizeOffsetType visitArgument(Argument &A);
SizeOffsetType visitCallSite(CallSite CS);
SizeOffsetType visitConstantPointerNull(ConstantPointerNull&);
SizeOffsetType visitExtractElementInst(ExtractElementInst &I);
SizeOffsetType visitExtractValueInst(ExtractValueInst &I);
SizeOffsetType visitGEPOperator(GEPOperator &GEP);
SizeOffsetType visitGlobalAlias(GlobalAlias &GA);
SizeOffsetType visitGlobalVariable(GlobalVariable &GV);
SizeOffsetType visitIntToPtrInst(IntToPtrInst&);
SizeOffsetType visitLoadInst(LoadInst &I);
SizeOffsetType visitPHINode(PHINode&);
SizeOffsetType visitSelectInst(SelectInst &I);
SizeOffsetType visitUndefValue(UndefValue&);
SizeOffsetType visitInstruction(Instruction &I);
};
typedef std::pair<Value*, Value*> SizeOffsetEvalType;
/// \brief Evaluate the size and offset of an object ponted by a Value*.
/// May create code to compute the result at run-time.
class ObjectSizeOffsetEvaluator
: public InstVisitor<ObjectSizeOffsetEvaluator, SizeOffsetEvalType> {
typedef IRBuilder<true, TargetFolder> BuilderTy;
typedef std::pair<WeakVH, WeakVH> WeakEvalType;
typedef DenseMap<const Value*, WeakEvalType> CacheMapTy;
typedef SmallPtrSet<const Value*, 8> PtrSetTy;
const DataLayout *TD;
const TargetLibraryInfo *TLI;
LLVMContext &Context;
BuilderTy Builder;
IntegerType *IntTy;
Value *Zero;
CacheMapTy CacheMap;
PtrSetTy SeenVals;
SizeOffsetEvalType unknown() {
return std::make_pair((Value*)0, (Value*)0);
}
SizeOffsetEvalType compute_(Value *V);
public:
ObjectSizeOffsetEvaluator(const DataLayout *TD, const TargetLibraryInfo *TLI,
LLVMContext &Context);
SizeOffsetEvalType compute(Value *V);
bool knownSize(SizeOffsetEvalType SizeOffset) {
return SizeOffset.first;
}
bool knownOffset(SizeOffsetEvalType SizeOffset) {
return SizeOffset.second;
}
bool anyKnown(SizeOffsetEvalType SizeOffset) {
return knownSize(SizeOffset) || knownOffset(SizeOffset);
}
bool bothKnown(SizeOffsetEvalType SizeOffset) {
return knownSize(SizeOffset) && knownOffset(SizeOffset);
}
SizeOffsetEvalType visitAllocaInst(AllocaInst &I);
SizeOffsetEvalType visitCallSite(CallSite CS);
SizeOffsetEvalType visitExtractElementInst(ExtractElementInst &I);
SizeOffsetEvalType visitExtractValueInst(ExtractValueInst &I);
SizeOffsetEvalType visitGEPOperator(GEPOperator &GEP);
SizeOffsetEvalType visitIntToPtrInst(IntToPtrInst&);
SizeOffsetEvalType visitLoadInst(LoadInst &I);
SizeOffsetEvalType visitPHINode(PHINode &PHI);
SizeOffsetEvalType visitSelectInst(SelectInst &I);
SizeOffsetEvalType visitInstruction(Instruction &I);
};
} // End llvm namespace
#endif