X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FAnalysis%2FMemoryBuiltins.cpp;h=37e2e271ceeaaaaa229a9be1128f3b298b662a1f;hb=b68ca3e9c5791db9da07b7767a8ee915a104e99a;hp=dd05c298f6e571f13559e9b3791fdbec56d90cb1;hpb=a44766a4dd5783b2acfae83eb0428a19636cdd3a;p=oota-llvm.git diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp index dd05c298f6e..37e2e271cee 100644 --- a/lib/Analysis/MemoryBuiltins.cpp +++ b/lib/Analysis/MemoryBuiltins.cpp @@ -8,7 +8,7 @@ //===----------------------------------------------------------------------===// // // This family of functions identifies calls to builtin functions that allocate -// or free memory. +// or free memory. // //===----------------------------------------------------------------------===// @@ -17,12 +17,12 @@ #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/Statistic.h" #include "llvm/Analysis/ValueTracking.h" -#include "llvm/DataLayout.h" -#include "llvm/GlobalVariable.h" -#include "llvm/Instructions.h" -#include "llvm/Intrinsics.h" -#include "llvm/Metadata.h" -#include "llvm/Module.h" +#include "llvm/IR/DataLayout.h" +#include "llvm/IR/GlobalVariable.h" +#include "llvm/IR/Instructions.h" +#include "llvm/IR/Intrinsics.h" +#include "llvm/IR/Metadata.h" +#include "llvm/IR/Module.h" #include "llvm/Support/Debug.h" #include "llvm/Support/MathExtras.h" #include "llvm/Support/raw_ostream.h" @@ -31,12 +31,13 @@ using namespace llvm; enum AllocType { - MallocLike = 1<<0, // allocates - CallocLike = 1<<1, // allocates + bzero - ReallocLike = 1<<2, // reallocates - StrDupLike = 1<<3, + OpNewLike = 1<<0, // allocates; never returns null + MallocLike = 1<<1 | OpNewLike, // allocates; may return null + CallocLike = 1<<2, // allocates + bzero + ReallocLike = 1<<3, // reallocates + StrDupLike = 1<<4, AllocLike = MallocLike | CallocLike | StrDupLike, - AnyAlloc = MallocLike | CallocLike | ReallocLike | StrDupLike + AnyAlloc = AllocLike | ReallocLike }; struct AllocFnsTy { @@ -52,20 +53,20 @@ struct AllocFnsTy { static const AllocFnsTy AllocationFnData[] = { {LibFunc::malloc, MallocLike, 1, 0, -1}, {LibFunc::valloc, MallocLike, 1, 0, -1}, - {LibFunc::Znwj, MallocLike, 1, 0, -1}, // new(unsigned int) + {LibFunc::Znwj, OpNewLike, 1, 0, -1}, // new(unsigned int) {LibFunc::ZnwjRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned int, nothrow) - {LibFunc::Znwm, MallocLike, 1, 0, -1}, // new(unsigned long) + {LibFunc::Znwm, OpNewLike, 1, 0, -1}, // new(unsigned long) {LibFunc::ZnwmRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned long, nothrow) - {LibFunc::Znaj, MallocLike, 1, 0, -1}, // new[](unsigned int) + {LibFunc::Znaj, OpNewLike, 1, 0, -1}, // new[](unsigned int) {LibFunc::ZnajRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned int, nothrow) - {LibFunc::Znam, MallocLike, 1, 0, -1}, // new[](unsigned long) + {LibFunc::Znam, OpNewLike, 1, 0, -1}, // new[](unsigned long) {LibFunc::ZnamRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned long, nothrow) - {LibFunc::posix_memalign, MallocLike, 3, 2, -1}, {LibFunc::calloc, CallocLike, 2, 0, 1}, {LibFunc::realloc, ReallocLike, 2, 1, -1}, {LibFunc::reallocf, ReallocLike, 2, 1, -1}, {LibFunc::strdup, StrDupLike, 1, -1, -1}, {LibFunc::strndup, StrDupLike, 2, 1, -1} + // TODO: Handle "int posix_memalign(void **, size_t, size_t)" }; @@ -77,6 +78,9 @@ static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) { if (!CS.getInstruction()) return 0; + if (CS.isNoBuiltin()) + return 0; + Function *Callee = CS.getCalledFunction(); if (!Callee || !Callee->isDeclaration()) return 0; @@ -88,6 +92,10 @@ static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) { static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy, const TargetLibraryInfo *TLI, bool LookThroughBitCast = false) { + // Skip intrinsics + if (isa(V)) + return 0; + Function *Callee = getCalledFunction(V, LookThroughBitCast); if (!Callee) return 0; @@ -110,7 +118,7 @@ static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy, return 0; const AllocFnsTy *FnData = &AllocationFnData[i]; - if ((FnData->AllocTy & AllocTy) == 0) + if ((FnData->AllocTy & AllocTy) != FnData->AllocTy) return 0; // Check function prototype. @@ -182,6 +190,13 @@ bool llvm::isReallocLikeFn(const Value *V, const TargetLibraryInfo *TLI, return getAllocationData(V, ReallocLike, TLI, LookThroughBitCast); } +/// \brief Tests if a value is a call or invoke to a library function that +/// allocates memory and never returns null (such as operator new). +bool llvm::isOperatorNewLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, OpNewLike, TLI, LookThroughBitCast); +} + /// extractMallocCall - Returns the corresponding CallInst if the instruction /// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we /// ignore InvokeInst here. @@ -190,47 +205,47 @@ const CallInst *llvm::extractMallocCall(const Value *I, return isMallocLikeFn(I, TLI) ? dyn_cast(I) : 0; } -static Value *computeArraySize(const CallInst *CI, const DataLayout *TD, +static Value *computeArraySize(const CallInst *CI, const DataLayout *DL, const TargetLibraryInfo *TLI, bool LookThroughSExt = false) { if (!CI) - return NULL; + return 0; // The size of the malloc's result type must be known to determine array size. Type *T = getMallocAllocatedType(CI, TLI); - if (!T || !T->isSized() || !TD) - return NULL; + if (!T || !T->isSized() || !DL) + return 0; - unsigned ElementSize = TD->getTypeAllocSize(T); + unsigned ElementSize = DL->getTypeAllocSize(T); if (StructType *ST = dyn_cast(T)) - ElementSize = TD->getStructLayout(ST)->getSizeInBytes(); + ElementSize = DL->getStructLayout(ST)->getSizeInBytes(); // If malloc call's arg can be determined to be a multiple of ElementSize, // return the multiple. Otherwise, return NULL. Value *MallocArg = CI->getArgOperand(0); - Value *Multiple = NULL; + Value *Multiple = 0; if (ComputeMultiple(MallocArg, ElementSize, Multiple, LookThroughSExt)) return Multiple; - return NULL; + return 0; } -/// isArrayMalloc - Returns the corresponding CallInst if the instruction +/// 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 *llvm::isArrayMalloc(const Value *I, - const DataLayout *TD, + const DataLayout *DL, const TargetLibraryInfo *TLI) { const CallInst *CI = extractMallocCall(I, TLI); - Value *ArraySize = computeArraySize(CI, TD, TLI); + Value *ArraySize = computeArraySize(CI, DL, TLI); - if (ArraySize && - ArraySize != ConstantInt::get(CI->getArgOperand(0)->getType(), 1)) - return CI; + if (ConstantInt *ConstSize = dyn_cast_or_null(ArraySize)) + if (ConstSize->isOne()) + return CI; // CI is a non-array malloc or we can't figure out that it is an array malloc. - return NULL; + return 0; } /// getMallocType - Returns the PointerType resulting from the malloc call. @@ -241,8 +256,8 @@ const CallInst *llvm::isArrayMalloc(const Value *I, PointerType *llvm::getMallocType(const CallInst *CI, const TargetLibraryInfo *TLI) { assert(isMallocLikeFn(CI, TLI) && "getMallocType and not malloc call"); - - PointerType *MallocType = NULL; + + PointerType *MallocType = 0; unsigned NumOfBitCastUses = 0; // Determine if CallInst has a bitcast use. @@ -262,7 +277,7 @@ PointerType *llvm::getMallocType(const CallInst *CI, return cast(CI->getType()); // Type could not be determined. - return NULL; + return 0; } /// getMallocAllocatedType - Returns the Type allocated by malloc call. @@ -273,19 +288,19 @@ PointerType *llvm::getMallocType(const CallInst *CI, Type *llvm::getMallocAllocatedType(const CallInst *CI, const TargetLibraryInfo *TLI) { PointerType *PT = getMallocType(CI, TLI); - return PT ? PT->getElementType() : NULL; + return PT ? PT->getElementType() : 0; } -/// getMallocArraySize - Returns the array size of a malloc call. If the +/// 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 *llvm::getMallocArraySize(CallInst *CI, const DataLayout *TD, +Value *llvm::getMallocArraySize(CallInst *CI, const DataLayout *DL, const TargetLibraryInfo *TLI, bool LookThroughSExt) { assert(isMallocLikeFn(CI, TLI) && "getMallocArraySize and not malloc call"); - return computeArraySize(CI, TD, TLI, LookThroughSExt); + return computeArraySize(CI, DL, TLI, LookThroughSExt); } @@ -300,7 +315,7 @@ const CallInst *llvm::extractCallocCall(const Value *I, /// isFreeCall - Returns non-null if the value is a call to the builtin free() const CallInst *llvm::isFreeCall(const Value *I, const TargetLibraryInfo *TLI) { const CallInst *CI = dyn_cast(I); - if (!CI) + if (!CI || isa(CI)) return 0; Function *Callee = CI->getCalledFunction(); if (Callee == 0 || !Callee->isDeclaration()) @@ -311,18 +326,24 @@ const CallInst *llvm::isFreeCall(const Value *I, const TargetLibraryInfo *TLI) { if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn)) return 0; - if (TLIFn != LibFunc::free && - TLIFn != LibFunc::ZdlPv && // operator delete(void*) - TLIFn != LibFunc::ZdaPv) // operator delete[](void*) + unsigned ExpectedNumParams; + if (TLIFn == LibFunc::free || + TLIFn == LibFunc::ZdlPv || // operator delete(void*) + TLIFn == LibFunc::ZdaPv) // operator delete[](void*) + ExpectedNumParams = 1; + else if (TLIFn == LibFunc::ZdlPvRKSt9nothrow_t || // delete(void*, nothrow) + TLIFn == LibFunc::ZdaPvRKSt9nothrow_t) // delete[](void*, nothrow) + ExpectedNumParams = 2; + else return 0; // Check free prototype. - // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin + // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin // attribute will exist. FunctionType *FTy = Callee->getFunctionType(); if (!FTy->getReturnType()->isVoidTy()) return 0; - if (FTy->getNumParams() != 1) + if (FTy->getNumParams() != ExpectedNumParams) return 0; if (FTy->getParamType(0) != Type::getInt8PtrTy(Callee->getContext())) return 0; @@ -341,12 +362,12 @@ const CallInst *llvm::isFreeCall(const Value *I, const TargetLibraryInfo *TLI) { /// 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 llvm::getObjectSize(const Value *Ptr, uint64_t &Size, const DataLayout *TD, +bool llvm::getObjectSize(const Value *Ptr, uint64_t &Size, const DataLayout *DL, const TargetLibraryInfo *TLI, bool RoundToAlign) { - if (!TD) + if (!DL) return false; - ObjectSizeOffsetVisitor Visitor(TD, TLI, Ptr->getContext(), RoundToAlign); + ObjectSizeOffsetVisitor Visitor(DL, TLI, Ptr->getContext(), RoundToAlign); SizeOffsetType Data = Visitor.compute(const_cast(Ptr)); if (!Visitor.bothKnown(Data)) return false; @@ -373,17 +394,19 @@ APInt ObjectSizeOffsetVisitor::align(APInt Size, uint64_t Align) { return Size; } -ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const DataLayout *TD, +ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const DataLayout *DL, const TargetLibraryInfo *TLI, LLVMContext &Context, bool RoundToAlign) -: TD(TD), TLI(TLI), RoundToAlign(RoundToAlign) { - IntegerType *IntTy = TD->getIntPtrType(Context); - IntTyBits = IntTy->getBitWidth(); - Zero = APInt::getNullValue(IntTyBits); +: DL(DL), TLI(TLI), RoundToAlign(RoundToAlign) { + // Pointer size must be rechecked for each object visited since it could have + // a different address space. } SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) { + IntTyBits = DL->getPointerTypeSizeInBits(V->getType()); + Zero = APInt::getNullValue(IntTyBits); + V = V->stripPointerCasts(); if (Instruction *I = dyn_cast(V)) { // If we have already seen this instruction, bail out. Cycles can happen in @@ -421,7 +444,7 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitAllocaInst(AllocaInst &I) { if (!I.getAllocatedType()->isSized()) return unknown(); - APInt Size(IntTyBits, TD->getTypeAllocSize(I.getAllocatedType())); + APInt Size(IntTyBits, DL->getTypeAllocSize(I.getAllocatedType())); if (!I.isArrayAllocation()) return std::make_pair(align(Size, I.getAlignment()), Zero); @@ -440,7 +463,7 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitArgument(Argument &A) { return unknown(); } PointerType *PT = cast(A.getType()); - APInt Size(IntTyBits, TD->getTypeAllocSize(PT->getElementType())); + APInt Size(IntTyBits, DL->getTypeAllocSize(PT->getElementType())); return std::make_pair(align(Size, A.getParamAlignment()), Zero); } @@ -513,7 +536,7 @@ ObjectSizeOffsetVisitor::visitExtractValueInst(ExtractValueInst&) { SizeOffsetType ObjectSizeOffsetVisitor::visitGEPOperator(GEPOperator &GEP) { SizeOffsetType PtrData = compute(GEP.getPointerOperand()); APInt Offset(IntTyBits, 0); - if (!bothKnown(PtrData) || !GEP.accumulateConstantOffset(*TD, Offset)) + if (!bothKnown(PtrData) || !GEP.accumulateConstantOffset(*DL, Offset)) return unknown(); return std::make_pair(PtrData.first, PtrData.second + Offset); @@ -529,7 +552,7 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitGlobalVariable(GlobalVariable &GV){ if (!GV.hasDefinitiveInitializer()) return unknown(); - APInt Size(IntTyBits, TD->getTypeAllocSize(GV.getType()->getElementType())); + APInt Size(IntTyBits, DL->getTypeAllocSize(GV.getType()->getElementType())); return std::make_pair(align(Size, GV.getAlignment()), Zero); } @@ -543,26 +566,15 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitLoadInst(LoadInst&) { return unknown(); } -SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode &PHI) { - if (PHI.getNumIncomingValues() == 0) - return unknown(); - - SizeOffsetType Ret = compute(PHI.getIncomingValue(0)); - if (!bothKnown(Ret)) - return unknown(); - - // verify that all PHI incoming pointers have the same size and offset - for (unsigned i = 1, e = PHI.getNumIncomingValues(); i != e; ++i) { - if (compute(PHI.getIncomingValue(i)) != Ret) - return unknown(); - } - return Ret; +SizeOffsetType ObjectSizeOffsetVisitor::visitPHINode(PHINode&) { + // too complex to analyze statically. + return unknown(); } SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) { SizeOffsetType TrueSide = compute(I.getTrueValue()); SizeOffsetType FalseSide = compute(I.getFalseValue()); - if (TrueSide == FalseSide) + if (bothKnown(TrueSide) && bothKnown(FalseSide) && TrueSide == FalseSide) return TrueSide; return unknown(); } @@ -576,16 +588,21 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitInstruction(Instruction &I) { return unknown(); } - -ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const DataLayout *TD, - const TargetLibraryInfo *TLI, - LLVMContext &Context) -: TD(TD), TLI(TLI), Context(Context), Builder(Context, TargetFolder(TD)) { - IntTy = TD->getIntPtrType(Context); - Zero = ConstantInt::get(IntTy, 0); +ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const DataLayout *DL, + const TargetLibraryInfo *TLI, + LLVMContext &Context, + bool RoundToAlign) +: DL(DL), TLI(TLI), Context(Context), Builder(Context, TargetFolder(DL)), + RoundToAlign(RoundToAlign) { + // IntTy and Zero must be set for each compute() since the address space may + // be different for later objects. } SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute(Value *V) { + // XXX - Are vectors of pointers possible here? + IntTy = cast(DL->getIntPtrType(V->getType())); + Zero = ConstantInt::get(IntTy, 0); + SizeOffsetEvalType Result = compute_(V); if (!bothKnown(Result)) { @@ -605,7 +622,7 @@ SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute(Value *V) { } SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) { - ObjectSizeOffsetVisitor Visitor(TD, TLI, Context); + ObjectSizeOffsetVisitor Visitor(DL, TLI, Context, RoundToAlign); SizeOffsetType Const = Visitor.compute(V); if (Visitor.bothKnown(Const)) return std::make_pair(ConstantInt::get(Context, Const.first), @@ -624,13 +641,15 @@ SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) { if (Instruction *I = dyn_cast(V)) Builder.SetInsertPoint(I); - // record the pointers that were handled in this run, so that they can be - // cleaned later if something fails - SeenVals.insert(V); - // now compute the size and offset SizeOffsetEvalType Result; - if (GEPOperator *GEP = dyn_cast(V)) { + + // Record the pointers that were handled in this run, so that they can be + // cleaned later if something fails. We also use this set to break cycles that + // can occur in dead code. + if (!SeenVals.insert(V)) { + Result = unknown(); + } else if (GEPOperator *GEP = dyn_cast(V)) { Result = visitGEPOperator(*GEP); } else if (Instruction *I = dyn_cast(V)) { Result = visit(*I); @@ -663,7 +682,7 @@ SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitAllocaInst(AllocaInst &I) { assert(I.isArrayAllocation()); Value *ArraySize = I.getArraySize(); Value *Size = ConstantInt::get(ArraySize->getType(), - TD->getTypeAllocSize(I.getAllocatedType())); + DL->getTypeAllocSize(I.getAllocatedType())); Size = Builder.CreateMul(Size, ArraySize); return std::make_pair(Size, Zero); } @@ -715,7 +734,7 @@ ObjectSizeOffsetEvaluator::visitGEPOperator(GEPOperator &GEP) { if (!bothKnown(PtrData)) return unknown(); - Value *Offset = EmitGEPOffset(&Builder, *TD, &GEP, /*NoAssumptions=*/true); + Value *Offset = EmitGEPOffset(&Builder, *DL, &GEP, /*NoAssumptions=*/true); Offset = Builder.CreateAdd(PtrData.second, Offset); return std::make_pair(PtrData.first, Offset); }