X-Git-Url: http://plrg.eecs.uci.edu/git/?p=oota-llvm.git;a=blobdiff_plain;f=lib%2FAnalysis%2FMemoryBuiltins.cpp;h=8ddac8ffb971c7de573cd76e6e8411ef4db392d4;hp=8d99ec3e5643600127f701323eda5e94fbaa69de;hb=f6f87835dae0dc05884652ef57d0c969c1ffe2a6;hpb=c606c3ff911eddcbf8bab95e67c7d8c1f69a493e diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp index 8d99ec3e564..8ddac8ffb97 100644 --- a/lib/Analysis/MemoryBuiltins.cpp +++ b/lib/Analysis/MemoryBuiltins.cpp @@ -8,38 +8,41 @@ //===----------------------------------------------------------------------===// // // This family of functions identifies calls to builtin functions that allocate -// or free memory. +// or free memory. // //===----------------------------------------------------------------------===// -#define DEBUG_TYPE "memory-builtins" -#include "llvm/ADT/Statistic.h" -#include "llvm/ADT/STLExtras.h" #include "llvm/Analysis/MemoryBuiltins.h" -#include "llvm/GlobalVariable.h" -#include "llvm/Instructions.h" -#include "llvm/Intrinsics.h" -#include "llvm/Metadata.h" -#include "llvm/Module.h" +#include "llvm/ADT/STLExtras.h" +#include "llvm/ADT/Statistic.h" +#include "llvm/Analysis/TargetLibraryInfo.h" #include "llvm/Analysis/ValueTracking.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" -#include "llvm/Target/TargetData.h" #include "llvm/Transforms/Utils/Local.h" using namespace llvm; +#define DEBUG_TYPE "memory-builtins" + 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 { - const char *Name; + LibFunc::Func Func; AllocType AllocTy; unsigned char NumParams; // First and Second size parameters (or -1 if unused) @@ -49,22 +52,22 @@ struct AllocFnsTy { // FIXME: certain users need more information. E.g., SimplifyLibCalls needs to // know which functions are nounwind, noalias, nocapture parameters, etc. static const AllocFnsTy AllocationFnData[] = { - {"malloc", MallocLike, 1, 0, -1}, - {"valloc", MallocLike, 1, 0, -1}, - {"_Znwj", MallocLike, 1, 0, -1}, // new(unsigned int) - {"_ZnwjRKSt9nothrow_t", MallocLike, 2, 0, -1}, // new(unsigned int, nothrow) - {"_Znwm", MallocLike, 1, 0, -1}, // new(unsigned long) - {"_ZnwmRKSt9nothrow_t", MallocLike, 2, 0, -1}, // new(unsigned long, nothrow) - {"_Znaj", MallocLike, 1, 0, -1}, // new[](unsigned int) - {"_ZnajRKSt9nothrow_t", MallocLike, 2, 0, -1}, // new[](unsigned int, nothrow) - {"_Znam", MallocLike, 1, 0, -1}, // new[](unsigned long) - {"_ZnamRKSt9nothrow_t", MallocLike, 2, 0, -1}, // new[](unsigned long, nothrow) - {"posix_memalign", MallocLike, 3, 2, -1}, - {"calloc", CallocLike, 2, 0, 1}, - {"realloc", ReallocLike, 2, 1, -1}, - {"reallocf", ReallocLike, 2, 1, -1}, - {"strdup", StrDupLike, 1, -1, -1}, - {"strndup", StrDupLike, 2, -1, -1} + {LibFunc::malloc, MallocLike, 1, 0, -1}, + {LibFunc::valloc, MallocLike, 1, 0, -1}, + {LibFunc::Znwj, OpNewLike, 1, 0, -1}, // new(unsigned int) + {LibFunc::ZnwjRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned int, nothrow) + {LibFunc::Znwm, OpNewLike, 1, 0, -1}, // new(unsigned long) + {LibFunc::ZnwmRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned long, nothrow) + {LibFunc::Znaj, OpNewLike, 1, 0, -1}, // new[](unsigned int) + {LibFunc::ZnajRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned int, nothrow) + {LibFunc::Znam, OpNewLike, 1, 0, -1}, // new[](unsigned long) + {LibFunc::ZnamRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned long, nothrow) + {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)" }; @@ -74,39 +77,52 @@ static Function *getCalledFunction(const Value *V, bool LookThroughBitCast) { CallSite CS(const_cast(V)); if (!CS.getInstruction()) - return 0; + return nullptr; + + if (CS.isNoBuiltin()) + return nullptr; Function *Callee = CS.getCalledFunction(); if (!Callee || !Callee->isDeclaration()) - return 0; + return nullptr; return Callee; } /// \brief Returns the allocation data for the given value if it is a call to a /// known allocation function, and NULL otherwise. static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy, + const TargetLibraryInfo *TLI, bool LookThroughBitCast = false) { + // Skip intrinsics + if (isa(V)) + return nullptr; + Function *Callee = getCalledFunction(V, LookThroughBitCast); if (!Callee) - return 0; + return nullptr; + + // Make sure that the function is available. + StringRef FnName = Callee->getName(); + LibFunc::Func TLIFn; + if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn)) + return nullptr; unsigned i = 0; bool found = false; for ( ; i < array_lengthof(AllocationFnData); ++i) { - if (Callee->getName() == AllocationFnData[i].Name) { + if (AllocationFnData[i].Func == TLIFn) { found = true; break; } } if (!found) - return 0; + return nullptr; const AllocFnsTy *FnData = &AllocationFnData[i]; - if ((FnData->AllocTy & AllocTy) == 0) - return 0; + if ((FnData->AllocTy & AllocTy) != FnData->AllocTy) + return nullptr; // Check function prototype. - // FIXME: Check the nobuiltin metadata?? (PR5130) int FstParam = FnData->FstParam; int SndParam = FnData->SndParam; FunctionType *FTy = Callee->getFunctionType(); @@ -120,7 +136,7 @@ static const AllocFnsTy *getAllocationData(const Value *V, AllocType AllocTy, FTy->getParamType(SndParam)->isIntegerTy(32) || FTy->getParamType(SndParam)->isIntegerTy(64))) return FnData; - return 0; + return nullptr; } static bool hasNoAliasAttr(const Value *V, bool LookThroughBitCast) { @@ -132,88 +148,88 @@ static bool hasNoAliasAttr(const Value *V, bool LookThroughBitCast) { /// \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 llvm::isAllocationFn(const Value *V, bool LookThroughBitCast) { - return getAllocationData(V, AnyAlloc, LookThroughBitCast); +bool llvm::isAllocationFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, AnyAlloc, TLI, LookThroughBitCast); } /// \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 llvm::isNoAliasFn(const Value *V, bool LookThroughBitCast) { +bool llvm::isNoAliasFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { // it's safe to consider realloc as noalias since accessing the original // pointer is undefined behavior - return isAllocationFn(V, LookThroughBitCast) || + return isAllocationFn(V, TLI, LookThroughBitCast) || hasNoAliasAttr(V, LookThroughBitCast); } /// \brief Tests if a value is a call or invoke to a library function that /// allocates uninitialized memory (such as malloc). -bool llvm::isMallocLikeFn(const Value *V, bool LookThroughBitCast) { - return getAllocationData(V, MallocLike, LookThroughBitCast); +bool llvm::isMallocLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, MallocLike, TLI, LookThroughBitCast); } /// \brief Tests if a value is a call or invoke to a library function that /// allocates zero-filled memory (such as calloc). -bool llvm::isCallocLikeFn(const Value *V, bool LookThroughBitCast) { - return getAllocationData(V, CallocLike, LookThroughBitCast); +bool llvm::isCallocLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, CallocLike, TLI, LookThroughBitCast); } /// \brief Tests if a value is a call or invoke to a library function that /// allocates memory (either malloc, calloc, or strdup like). -bool llvm::isAllocLikeFn(const Value *V, bool LookThroughBitCast) { - return getAllocationData(V, AllocLike, LookThroughBitCast); +bool llvm::isAllocLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + return getAllocationData(V, AllocLike, TLI, LookThroughBitCast); } /// \brief Tests if a value is a call or invoke to a library function that /// reallocates memory (such as realloc). -bool llvm::isReallocLikeFn(const Value *V, bool LookThroughBitCast) { - return getAllocationData(V, ReallocLike, LookThroughBitCast); +bool llvm::isReallocLikeFn(const Value *V, const TargetLibraryInfo *TLI, + bool LookThroughBitCast) { + 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. -const CallInst *llvm::extractMallocCall(const Value *I) { - return isMallocLikeFn(I) ? dyn_cast(I) : 0; +const CallInst *llvm::extractMallocCall(const Value *I, + const TargetLibraryInfo *TLI) { + return isMallocLikeFn(I, TLI) ? dyn_cast(I) : nullptr; } -static Value *computeArraySize(const CallInst *CI, const TargetData *TD, +static Value *computeArraySize(const CallInst *CI, const DataLayout &DL, + const TargetLibraryInfo *TLI, bool LookThroughSExt = false) { if (!CI) - return NULL; + return nullptr; // The size of the malloc's result type must be known to determine array size. - Type *T = getMallocAllocatedType(CI); - if (!T || !T->isSized() || !TD) - return NULL; + Type *T = getMallocAllocatedType(CI, TLI); + if (!T || !T->isSized()) + return nullptr; - 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 = nullptr; if (ComputeMultiple(MallocArg, ElementSize, Multiple, LookThroughSExt)) return Multiple; - return NULL; -} - -/// 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 TargetData *TD) { - const CallInst *CI = extractMallocCall(I); - Value *ArraySize = computeArraySize(CI, TD); - - if (ArraySize && - ArraySize != ConstantInt::get(CI->getArgOperand(0)->getType(), 1)) - return CI; - - // CI is a non-array malloc or we can't figure out that it is an array malloc. - return NULL; + return nullptr; } /// getMallocType - Returns the PointerType resulting from the malloc call. @@ -221,15 +237,16 @@ const CallInst *llvm::isArrayMalloc(const Value *I, const TargetData *TD) { /// 0: PointerType is the calls' return type. /// 1: PointerType is the bitcast's result type. /// >1: Unique PointerType cannot be determined, return NULL. -PointerType *llvm::getMallocType(const CallInst *CI) { - assert(isMallocLikeFn(CI) && "getMallocType and not malloc call"); - - PointerType *MallocType = NULL; +PointerType *llvm::getMallocType(const CallInst *CI, + const TargetLibraryInfo *TLI) { + assert(isMallocLikeFn(CI, TLI) && "getMallocType and not malloc call"); + + PointerType *MallocType = nullptr; unsigned NumOfBitCastUses = 0; // Determine if CallInst has a bitcast use. - for (Value::const_use_iterator UI = CI->use_begin(), E = CI->use_end(); - UI != E; ) + for (Value::const_user_iterator UI = CI->user_begin(), E = CI->user_end(); + UI != E;) if (const BitCastInst *BCI = dyn_cast(*UI++)) { MallocType = cast(BCI->getDestTy()); NumOfBitCastUses++; @@ -244,7 +261,7 @@ PointerType *llvm::getMallocType(const CallInst *CI) { return cast(CI->getType()); // Type could not be determined. - return NULL; + return nullptr; } /// getMallocAllocatedType - Returns the Type allocated by malloc call. @@ -252,54 +269,72 @@ PointerType *llvm::getMallocType(const CallInst *CI) { /// 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 *llvm::getMallocAllocatedType(const CallInst *CI) { - PointerType *PT = getMallocType(CI); - return PT ? PT->getElementType() : NULL; +Type *llvm::getMallocAllocatedType(const CallInst *CI, + const TargetLibraryInfo *TLI) { + PointerType *PT = getMallocType(CI, TLI); + return PT ? PT->getElementType() : nullptr; } -/// 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 TargetData *TD, +Value *llvm::getMallocArraySize(CallInst *CI, const DataLayout &DL, + const TargetLibraryInfo *TLI, bool LookThroughSExt) { - assert(isMallocLikeFn(CI) && "getMallocArraySize and not malloc call"); - return computeArraySize(CI, TD, LookThroughSExt); + assert(isMallocLikeFn(CI, TLI) && "getMallocArraySize and not malloc call"); + return computeArraySize(CI, DL, TLI, LookThroughSExt); } /// extractCallocCall - Returns the corresponding CallInst if the instruction /// is a calloc call. -const CallInst *llvm::extractCallocCall(const Value *I) { - return isCallocLikeFn(I) ? cast(I) : 0; +const CallInst *llvm::extractCallocCall(const Value *I, + const TargetLibraryInfo *TLI) { + return isCallocLikeFn(I, TLI) ? cast(I) : nullptr; } /// isFreeCall - Returns non-null if the value is a call to the builtin free() -const CallInst *llvm::isFreeCall(const Value *I) { +const CallInst *llvm::isFreeCall(const Value *I, const TargetLibraryInfo *TLI) { const CallInst *CI = dyn_cast(I); - if (!CI) - return 0; + if (!CI || isa(CI)) + return nullptr; Function *Callee = CI->getCalledFunction(); - if (Callee == 0 || !Callee->isDeclaration()) - return 0; - - if (Callee->getName() != "free" && - Callee->getName() != "_ZdlPv" && // operator delete(void*) - Callee->getName() != "_ZdaPv") // operator delete[](void*) - return 0; + if (Callee == nullptr) + return nullptr; + + StringRef FnName = Callee->getName(); + LibFunc::Func TLIFn; + if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn)) + return nullptr; + + unsigned ExpectedNumParams; + if (TLIFn == LibFunc::free || + TLIFn == LibFunc::ZdlPv || // operator delete(void*) + TLIFn == LibFunc::ZdaPv) // operator delete[](void*) + ExpectedNumParams = 1; + else if (TLIFn == LibFunc::ZdlPvj || // delete(void*, uint) + TLIFn == LibFunc::ZdlPvm || // delete(void*, ulong) + TLIFn == LibFunc::ZdlPvRKSt9nothrow_t || // delete(void*, nothrow) + TLIFn == LibFunc::ZdaPvj || // delete[](void*, uint) + TLIFn == LibFunc::ZdaPvm || // delete[](void*, ulong) + TLIFn == LibFunc::ZdaPvRKSt9nothrow_t) // delete[](void*, nothrow) + ExpectedNumParams = 2; + else + return nullptr; // 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) - return 0; + return nullptr; + if (FTy->getNumParams() != ExpectedNumParams) + return nullptr; if (FTy->getParamType(0) != Type::getInt8PtrTy(Callee->getContext())) - return 0; + return nullptr; return CI; } @@ -315,12 +350,9 @@ const CallInst *llvm::isFreeCall(const Value *I) { /// 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 TargetData *TD, - bool RoundToAlign) { - if (!TD) - return false; - - ObjectSizeOffsetVisitor Visitor(TD, Ptr->getContext(), RoundToAlign); +bool llvm::getObjectSize(const Value *Ptr, uint64_t &Size, const DataLayout &DL, + const TargetLibraryInfo *TLI, bool RoundToAlign) { + ObjectSizeOffsetVisitor Visitor(DL, TLI, Ptr->getContext(), RoundToAlign); SizeOffsetType Data = Visitor.compute(const_cast(Ptr)); if (!Visitor.bothKnown(Data)) return false; @@ -347,33 +379,46 @@ APInt ObjectSizeOffsetVisitor::align(APInt Size, uint64_t Align) { return Size; } -ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const TargetData *TD, +ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const DataLayout &DL, + const TargetLibraryInfo *TLI, LLVMContext &Context, bool RoundToAlign) -: TD(TD), 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 + // unreachable code after constant propagation. + if (!SeenInsts.insert(I).second) + return unknown(); - if (GEPOperator *GEP = dyn_cast(V)) - return visitGEPOperator(*GEP); - if (Instruction *I = dyn_cast(V)) + if (GEPOperator *GEP = dyn_cast(V)) + return visitGEPOperator(*GEP); return visit(*I); + } if (Argument *A = dyn_cast(V)) return visitArgument(*A); if (ConstantPointerNull *P = dyn_cast(V)) return visitConstantPointerNull(*P); + if (GlobalAlias *GA = dyn_cast(V)) + return visitGlobalAlias(*GA); if (GlobalVariable *GV = dyn_cast(V)) return visitGlobalVariable(*GV); if (UndefValue *UV = dyn_cast(V)) return visitUndefValue(*UV); - if (ConstantExpr *CE = dyn_cast(V)) + if (ConstantExpr *CE = dyn_cast(V)) { if (CE->getOpcode() == Instruction::IntToPtr) return unknown(); // clueless + if (CE->getOpcode() == Instruction::GetElementPtr) + return visitGEPOperator(cast(*CE)); + } DEBUG(dbgs() << "ObjectSizeOffsetVisitor::compute() unhandled value: " << *V << '\n'); @@ -384,7 +429,7 @@ 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); @@ -398,24 +443,38 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitAllocaInst(AllocaInst &I) { SizeOffsetType ObjectSizeOffsetVisitor::visitArgument(Argument &A) { // no interprocedural analysis is done at the moment - if (!A.hasByValAttr()) { + if (!A.hasByValOrInAllocaAttr()) { ++ObjectVisitorArgument; 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); } SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) { - const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc); + const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc, + TLI); if (!FnData) return unknown(); // handle strdup-like functions separately if (FnData->AllocTy == StrDupLike) { - // TODO - return unknown(); + APInt Size(IntTyBits, GetStringLength(CS.getArgument(0))); + if (!Size) + return unknown(); + + // strndup limits strlen + if (FnData->FstParam > 0) { + ConstantInt *Arg= dyn_cast(CS.getArgument(FnData->FstParam)); + if (!Arg) + return unknown(); + + APInt MaxSize = Arg->getValue().zextOrSelf(IntTyBits); + if (Size.ugt(MaxSize)) + Size = MaxSize + 1; + } + return std::make_pair(Size, Zero); } ConstantInt *Arg = dyn_cast(CS.getArgument(FnData->FstParam)); @@ -461,19 +520,24 @@ ObjectSizeOffsetVisitor::visitExtractValueInst(ExtractValueInst&) { SizeOffsetType ObjectSizeOffsetVisitor::visitGEPOperator(GEPOperator &GEP) { SizeOffsetType PtrData = compute(GEP.getPointerOperand()); - if (!bothKnown(PtrData) || !GEP.hasAllConstantIndices()) + APInt Offset(IntTyBits, 0); + if (!bothKnown(PtrData) || !GEP.accumulateConstantOffset(DL, Offset)) return unknown(); - SmallVector Ops(GEP.idx_begin(), GEP.idx_end()); - APInt Offset(IntTyBits,TD->getIndexedOffset(GEP.getPointerOperandType(),Ops)); return std::make_pair(PtrData.first, PtrData.second + Offset); } +SizeOffsetType ObjectSizeOffsetVisitor::visitGlobalAlias(GlobalAlias &GA) { + if (GA.mayBeOverridden()) + return unknown(); + return compute(GA.getAliasee()); +} + 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); } @@ -509,16 +573,20 @@ SizeOffsetType ObjectSizeOffsetVisitor::visitInstruction(Instruction &I) { return unknown(); } - -ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const TargetData *TD, - LLVMContext &Context) -: TD(TD), Context(Context), Builder(Context, TargetFolder(TD)), -Visitor(TD, Context) { - 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)) { @@ -538,6 +606,7 @@ SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute(Value *V) { } SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) { + ObjectSizeOffsetVisitor Visitor(DL, TLI, Context, RoundToAlign); SizeOffsetType Const = Visitor.compute(V); if (Visitor.bothKnown(Const)) return std::make_pair(ConstantInt::get(Context, Const.first), @@ -556,19 +625,22 @@ 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).second) { + Result = unknown(); + } else if (GEPOperator *GEP = dyn_cast(V)) { Result = visitGEPOperator(*GEP); } else if (Instruction *I = dyn_cast(V)) { Result = visit(*I); } else if (isa(V) || (isa(V) && cast(V)->getOpcode() == Instruction::IntToPtr) || + isa(V) || isa(V)) { // ignore values where we cannot do more than what ObjectSizeVisitor can Result = unknown(); @@ -594,13 +666,14 @@ 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); } SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitCallSite(CallSite CS) { - const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc); + const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc, + TLI); if (!FnData) return unknown(); @@ -645,7 +718,7 @@ 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); }