Check in LLVM r95781.
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
new file mode 100644
index 0000000..297b588
--- /dev/null
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -0,0 +1,207 @@
+//===------ MemoryBuiltins.cpp - Identify calls to memory builtins --------===//
+//
+// 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.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/MemoryBuiltins.h"
+#include "llvm/Constants.h"
+#include "llvm/Instructions.h"
+#include "llvm/Module.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Target/TargetData.h"
+using namespace llvm;
+
+//===----------------------------------------------------------------------===//
+// malloc Call Utility Functions.
+//
+
+/// isMalloc - Returns true if the value is either a malloc call or a
+/// bitcast of the result of a malloc call.
+bool llvm::isMalloc(const Value *I) {
+ return extractMallocCall(I) || extractMallocCallFromBitCast(I);
+}
+
+static bool isMallocCall(const CallInst *CI) {
+ if (!CI)
+ return false;
+
+ Function *Callee = CI->getCalledFunction();
+ if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "malloc")
+ return false;
+
+ // Check malloc prototype.
+ // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
+ // attribute will exist.
+ const FunctionType *FTy = Callee->getFunctionType();
+ if (FTy->getNumParams() != 1)
+ return false;
+ if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
+ if (ITy->getBitWidth() != 32 && ITy->getBitWidth() != 64)
+ return false;
+ return true;
+ }
+
+ return false;
+}
+
+/// 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) {
+ const CallInst *CI = dyn_cast<CallInst>(I);
+ return (isMallocCall(CI)) ? CI : NULL;
+}
+
+CallInst *llvm::extractMallocCall(Value *I) {
+ CallInst *CI = dyn_cast<CallInst>(I);
+ return (isMallocCall(CI)) ? CI : NULL;
+}
+
+static bool isBitCastOfMallocCall(const BitCastInst *BCI) {
+ if (!BCI)
+ return false;
+
+ return isMallocCall(dyn_cast<CallInst>(BCI->getOperand(0)));
+}
+
+/// extractMallocCallFromBitCast - Returns the corresponding CallInst if the
+/// instruction is a bitcast of the result of a malloc call.
+CallInst *llvm::extractMallocCallFromBitCast(Value *I) {
+ BitCastInst *BCI = dyn_cast<BitCastInst>(I);
+ return (isBitCastOfMallocCall(BCI)) ? cast<CallInst>(BCI->getOperand(0))
+ : NULL;
+}
+
+const CallInst *llvm::extractMallocCallFromBitCast(const Value *I) {
+ const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
+ return (isBitCastOfMallocCall(BCI)) ? cast<CallInst>(BCI->getOperand(0))
+ : NULL;
+}
+
+static Value *computeArraySize(const CallInst *CI, const TargetData *TD,
+ bool LookThroughSExt = false) {
+ if (!CI)
+ return NULL;
+
+ // The size of the malloc's result type must be known to determine array size.
+ const Type *T = getMallocAllocatedType(CI);
+ if (!T || !T->isSized() || !TD)
+ return NULL;
+
+ unsigned ElementSize = TD->getTypeAllocSize(T);
+ if (const StructType *ST = dyn_cast<StructType>(T))
+ ElementSize = TD->getStructLayout(ST)->getSizeInBytes();
+
+ // If malloc calls' arg can be determined to be a multiple of ElementSize,
+ // return the multiple. Otherwise, return NULL.
+ Value *MallocArg = CI->getOperand(1);
+ Value *Multiple = NULL;
+ 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->getOperand(1)->getType(), 1))
+ return CI;
+
+ // CI is a non-array malloc or we can't figure out that it is an array malloc.
+ return NULL;
+}
+
+/// 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 calls' return type.
+/// 1: PointerType is the bitcast's result type.
+/// >1: Unique PointerType cannot be determined, return NULL.
+const PointerType *llvm::getMallocType(const CallInst *CI) {
+ assert(isMalloc(CI) && "getMallocType and not malloc call");
+
+ const PointerType *MallocType = NULL;
+ unsigned NumOfBitCastUses = 0;
+
+ // Determine if CallInst has a bitcast use.
+ for (Value::use_const_iterator UI = CI->use_begin(), E = CI->use_end();
+ UI != E; )
+ if (const BitCastInst *BCI = dyn_cast<BitCastInst>(*UI++)) {
+ MallocType = cast<PointerType>(BCI->getDestTy());
+ NumOfBitCastUses++;
+ }
+
+ // Malloc call has 1 bitcast use, so type is the bitcast's destination type.
+ if (NumOfBitCastUses == 1)
+ return MallocType;
+
+ // Malloc call was not bitcast, so type is the malloc function's return type.
+ if (NumOfBitCastUses == 0)
+ return cast<PointerType>(CI->getType());
+
+ // Type could not be determined.
+ return NULL;
+}
+
+/// 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.
+const Type *llvm::getMallocAllocatedType(const CallInst *CI) {
+ const PointerType *PT = getMallocType(CI);
+ return PT ? PT->getElementType() : NULL;
+}
+
+/// 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,
+ bool LookThroughSExt) {
+ assert(isMalloc(CI) && "getMallocArraySize and not malloc call");
+ return computeArraySize(CI, TD, LookThroughSExt);
+}
+
+//===----------------------------------------------------------------------===//
+// free Call Utility Functions.
+//
+
+/// isFreeCall - Returns true if the value is a call to the builtin free()
+bool llvm::isFreeCall(const Value *I) {
+ const CallInst *CI = dyn_cast<CallInst>(I);
+ if (!CI)
+ return false;
+ Function *Callee = CI->getCalledFunction();
+ if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "free")
+ return false;
+
+ // Check free prototype.
+ // FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
+ // attribute will exist.
+ const FunctionType *FTy = Callee->getFunctionType();
+ if (!FTy->getReturnType()->isVoidTy())
+ return false;
+ if (FTy->getNumParams() != 1)
+ return false;
+ if (FTy->param_begin()->get() != Type::getInt8PtrTy(Callee->getContext()))
+ return false;
+
+ return true;
+}