//===----------------------------------------------------------------------===//
//
// 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/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/Target/TargetLibraryInfo.h"
#include "llvm/Transforms/Utils/Local.h"
using namespace llvm;
};
struct AllocFnsTy {
- const char *Name;
+ LibFunc::Func Func;
AllocType AllocTy;
unsigned char NumParams;
// First and Second size parameters (or -1 if unused)
// 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, MallocLike, 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::ZnwmRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned long, nothrow)
+ {LibFunc::Znaj, MallocLike, 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::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}
};
if (!CS.getInstruction())
return 0;
+ if (CS.isNoBuiltin())
+ return 0;
+
Function *Callee = CS.getCalledFunction();
if (!Callee || !Callee->isDeclaration())
return 0;
/// \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<IntrinsicInst>(V))
+ return 0;
+
Function *Callee = getCalledFunction(V, LookThroughBitCast);
if (!Callee)
return 0;
+ // Make sure that the function is available.
+ StringRef FnName = Callee->getName();
+ LibFunc::Func TLIFn;
+ if (!TLI || !TLI->getLibFunc(FnName, TLIFn) || !TLI->has(TLIFn))
+ return 0;
+
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;
}
return 0;
// Check function prototype.
- // FIXME: Check the nobuiltin metadata?? (PR5130)
int FstParam = FnData->FstParam;
int SndParam = FnData->SndParam;
FunctionType *FTy = Callee->getFunctionType();
/// \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);
}
/// 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<CallInst>(I) : 0;
+const CallInst *llvm::extractMallocCall(const Value *I,
+ const TargetLibraryInfo *TLI) {
+ return isMallocLikeFn(I, TLI) ? dyn_cast<CallInst>(I) : 0;
}
-static Value *computeArraySize(const CallInst *CI, const TargetData *TD,
+static Value *computeArraySize(const CallInst *CI, const DataLayout *TD,
+ 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);
+ Type *T = getMallocAllocatedType(CI, TLI);
if (!T || !T->isSized() || !TD)
- return NULL;
+ return 0;
unsigned ElementSize = TD->getTypeAllocSize(T);
if (StructType *ST = dyn_cast<StructType>(T))
// 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 TargetData *TD) {
- const CallInst *CI = extractMallocCall(I);
- Value *ArraySize = computeArraySize(CI, TD);
+const CallInst *llvm::isArrayMalloc(const Value *I,
+ const DataLayout *TD,
+ const TargetLibraryInfo *TLI) {
+ const CallInst *CI = extractMallocCall(I, TLI);
+ Value *ArraySize = computeArraySize(CI, TD, TLI);
- if (ArraySize &&
- ArraySize != ConstantInt::get(CI->getArgOperand(0)->getType(), 1))
- return CI;
+ if (ConstantInt *ConstSize = dyn_cast_or_null<ConstantInt>(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.
/// 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 = 0;
unsigned NumOfBitCastUses = 0;
// Determine if CallInst has a bitcast use.
return cast<PointerType>(CI->getType());
// Type could not be determined.
- return NULL;
+ return 0;
}
/// getMallocAllocatedType - Returns the Type allocated by 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 *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() : 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 TargetData *TD,
+Value *llvm::getMallocArraySize(CallInst *CI, const DataLayout *TD,
+ 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, TD, 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<CallInst>(I) : 0;
+const CallInst *llvm::extractCallocCall(const Value *I,
+ const TargetLibraryInfo *TLI) {
+ return isCallocLikeFn(I, TLI) ? cast<CallInst>(I) : 0;
}
/// 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<CallInst>(I);
- if (!CI)
+ if (!CI || isa<IntrinsicInst>(CI))
return 0;
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*)
+ StringRef FnName = Callee->getName();
+ LibFunc::Func TLIFn;
+ 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*)
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())
/// 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) {
+bool llvm::getObjectSize(const Value *Ptr, uint64_t &Size, const DataLayout *TD,
+ const TargetLibraryInfo *TLI, bool RoundToAlign) {
if (!TD)
return false;
- ObjectSizeOffsetVisitor Visitor(TD, Ptr->getContext(), RoundToAlign);
+ ObjectSizeOffsetVisitor Visitor(TD, TLI, Ptr->getContext(), RoundToAlign);
SizeOffsetType Data = Visitor.compute(const_cast<Value*>(Ptr));
if (!Visitor.bothKnown(Data))
return false;
return Size;
}
-ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const TargetData *TD,
+ObjectSizeOffsetVisitor::ObjectSizeOffsetVisitor(const DataLayout *TD,
+ const TargetLibraryInfo *TLI,
LLVMContext &Context,
bool RoundToAlign)
-: TD(TD), RoundToAlign(RoundToAlign) {
+: TD(TD), TLI(TLI), RoundToAlign(RoundToAlign) {
IntegerType *IntTy = TD->getIntPtrType(Context);
IntTyBits = IntTy->getBitWidth();
Zero = APInt::getNullValue(IntTyBits);
SizeOffsetType ObjectSizeOffsetVisitor::compute(Value *V) {
V = V->stripPointerCasts();
+ if (Instruction *I = dyn_cast<Instruction>(V)) {
+ // If we have already seen this instruction, bail out. Cycles can happen in
+ // unreachable code after constant propagation.
+ if (!SeenInsts.insert(I))
+ return unknown();
- if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
- return visitGEPOperator(*GEP);
- if (Instruction *I = dyn_cast<Instruction>(V))
+ if (GEPOperator *GEP = dyn_cast<GEPOperator>(V))
+ return visitGEPOperator(*GEP);
return visit(*I);
+ }
if (Argument *A = dyn_cast<Argument>(V))
return visitArgument(*A);
if (ConstantPointerNull *P = dyn_cast<ConstantPointerNull>(V))
return visitConstantPointerNull(*P);
+ if (GlobalAlias *GA = dyn_cast<GlobalAlias>(V))
+ return visitGlobalAlias(*GA);
if (GlobalVariable *GV = dyn_cast<GlobalVariable>(V))
return visitGlobalVariable(*GV);
if (UndefValue *UV = dyn_cast<UndefValue>(V))
return visitUndefValue(*UV);
- if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V))
+ if (ConstantExpr *CE = dyn_cast<ConstantExpr>(V)) {
if (CE->getOpcode() == Instruction::IntToPtr)
return unknown(); // clueless
+ if (CE->getOpcode() == Instruction::GetElementPtr)
+ return visitGEPOperator(cast<GEPOperator>(*CE));
+ }
DEBUG(dbgs() << "ObjectSizeOffsetVisitor::compute() unhandled value: " << *V
<< '\n');
}
SizeOffsetType ObjectSizeOffsetVisitor::visitCallSite(CallSite CS) {
- const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc);
+ const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc,
+ TLI);
if (!FnData)
return unknown();
SizeOffsetType ObjectSizeOffsetVisitor::visitGEPOperator(GEPOperator &GEP) {
SizeOffsetType PtrData = compute(GEP.getPointerOperand());
- if (!bothKnown(PtrData) || !GEP.hasAllConstantIndices())
+ APInt Offset(IntTyBits, 0);
+ if (!bothKnown(PtrData) || !GEP.accumulateConstantOffset(*TD, Offset))
return unknown();
- SmallVector<Value*, 8> 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();
}
SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) {
- // ignore malformed self-looping selects
- if (I.getTrueValue() == &I || I.getFalseValue() == &I)
- return unknown();
-
SizeOffsetType TrueSide = compute(I.getTrueValue());
SizeOffsetType FalseSide = compute(I.getFalseValue());
if (bothKnown(TrueSide) && bothKnown(FalseSide) && TrueSide == FalseSide)
}
-ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const TargetData *TD,
+ObjectSizeOffsetEvaluator::ObjectSizeOffsetEvaluator(const DataLayout *TD,
+ const TargetLibraryInfo *TLI,
LLVMContext &Context)
-: TD(TD), Context(Context), Builder(Context, TargetFolder(TD)),
-Visitor(TD, Context) {
+: TD(TD), TLI(TLI), Context(Context), Builder(Context, TargetFolder(TD)) {
IntTy = TD->getIntPtrType(Context);
Zero = ConstantInt::get(IntTy, 0);
}
}
SizeOffsetEvalType ObjectSizeOffsetEvaluator::compute_(Value *V) {
+ ObjectSizeOffsetVisitor Visitor(TD, TLI, Context);
SizeOffsetType Const = Visitor.compute(V);
if (Visitor.bothKnown(Const))
return std::make_pair(ConstantInt::get(Context, Const.first),
} else if (isa<Argument>(V) ||
(isa<ConstantExpr>(V) &&
cast<ConstantExpr>(V)->getOpcode() == Instruction::IntToPtr) ||
+ isa<GlobalAlias>(V) ||
isa<GlobalVariable>(V)) {
// ignore values where we cannot do more than what ObjectSizeVisitor can
Result = unknown();
}
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitCallSite(CallSite CS) {
- const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc);
+ const AllocFnsTy *FnData = getAllocationData(CS.getInstruction(), AnyAlloc,
+ TLI);
if (!FnData)
return unknown();
}
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitSelectInst(SelectInst &I) {
- // ignore malformed self-looping selects
- if (I.getTrueValue() == &I || I.getFalseValue() == &I)
- return unknown();
-
SizeOffsetEvalType TrueSide = compute_(I.getTrueValue());
SizeOffsetEvalType FalseSide = compute_(I.getFalseValue());
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