#include "llvm/Constants.h"
#include "llvm/Instructions.h"
#include "llvm/Module.h"
-#include "llvm/Analysis/ConstantFolding.h"
+#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/Target/TargetData.h"
using namespace llvm;
//===----------------------------------------------------------------------===//
// malloc Call Utility Functions.
//
-/// isMalloc - Returns true if the the value is either a malloc call or a
+/// 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) {
+bool llvm::isMalloc(const Value *I) {
return extractMallocCall(I) || extractMallocCallFromBitCast(I);
}
if (!CI)
return false;
- const Module* M = CI->getParent()->getParent()->getParent();
- Function *MallocFunc = M->getFunction("malloc");
-
- if (CI->getOperand(0) != MallocFunc)
+ 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 = MallocFunc->getFunctionType();
+ const FunctionType *FTy = Callee->getFunctionType();
if (FTy->getNumParams() != 1)
return false;
if (IntegerType *ITy = dyn_cast<IntegerType>(FTy->param_begin()->get())) {
/// 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 *llvm::extractMallocCall(const Value *I) {
const CallInst *CI = dyn_cast<CallInst>(I);
return (isMallocCall(CI)) ? CI : NULL;
}
-CallInst* llvm::extractMallocCall(Value* I) {
+CallInst *llvm::extractMallocCall(Value *I) {
CallInst *CI = dyn_cast<CallInst>(I);
return (isMallocCall(CI)) ? CI : NULL;
}
-static bool isBitCastOfMallocCall(const BitCastInst* BCI) {
+static bool isBitCastOfMallocCall(const BitCastInst *BCI) {
if (!BCI)
return false;
/// extractMallocCallFromBitCast - Returns the corresponding CallInst if the
/// instruction is a bitcast of the result of a malloc call.
-CallInst* llvm::extractMallocCallFromBitCast(Value* I) {
+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 CallInst *llvm::extractMallocCallFromBitCast(const Value *I) {
const BitCastInst *BCI = dyn_cast<BitCastInst>(I);
return (isBitCastOfMallocCall(BCI)) ? cast<CallInst>(BCI->getOperand(0))
: NULL;
}
-static bool isArrayMallocHelper(const CallInst *CI, LLVMContext &Context,
- const TargetData* TD) {
+static Value *computeArraySize(const CallInst *CI, const TargetData *TD,
+ bool LookThroughSExt = false) {
if (!CI)
- return false;
-
- const Type* T = getMallocAllocatedType(CI);
-
- // We can only indentify an array malloc if we know the type of the malloc
- // call.
- if (!T) return false;
-
- Value* MallocArg = CI->getOperand(1);
- Constant *ElementSize = ConstantExpr::getSizeOf(T);
- ElementSize = ConstantExpr::getTruncOrBitCast(ElementSize,
- MallocArg->getType());
- Constant *FoldedElementSize = ConstantFoldConstantExpression(
- cast<ConstantExpr>(ElementSize),
- Context, TD);
-
-
- if (isa<ConstantExpr>(MallocArg))
- return (MallocArg != ElementSize);
+ return NULL;
- BinaryOperator *BI = dyn_cast<BinaryOperator>(MallocArg);
- if (!BI)
- return false;
+ // 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;
- if (BI->getOpcode() == Instruction::Mul)
- // ArraySize * ElementSize
- if (BI->getOperand(1) == ElementSize ||
- (FoldedElementSize && BI->getOperand(1) == FoldedElementSize))
- return true;
+ unsigned ElementSize = TD->getTypeAllocSize(T);
+ if (const StructType *ST = dyn_cast<StructType>(T))
+ ElementSize = TD->getStructLayout(ST)->getSizeInBytes();
- // TODO: Detect case where MallocArg mul has been transformed to shl.
+ // 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;
+ if (ComputeMultiple(MallocArg, ElementSize, Multiple,
+ LookThroughSExt))
+ return Multiple;
- return false;
+ return NULL;
}
/// isArrayMalloc - Returns the corresponding CallInst if the instruction
-/// matches the malloc call IR generated by CallInst::CreateMalloc(). This
-/// means that it is a malloc call with one bitcast use AND the malloc call's
-/// size argument is:
-/// 1. a constant not equal to the size of the malloced type
-/// or
-/// 2. the result of a multiplication by the size of the malloced type
-/// Otherwise it returns NULL.
-/// The unique bitcast is needed to determine the type/size of the array
-/// allocation.
-CallInst* llvm::isArrayMalloc(Value* I, LLVMContext &Context,
- const TargetData* TD) {
- CallInst *CI = extractMallocCall(I);
- return (isArrayMallocHelper(CI, Context, TD)) ? CI : NULL;
-}
-
-const CallInst* llvm::isArrayMalloc(const Value* I, LLVMContext &Context,
- const TargetData* TD) {
+/// 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);
- return (isArrayMallocHelper(CI, Context, TD)) ? CI : NULL;
+ 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;
}
/// getMallocType - Returns the PointerType resulting from the malloc call.
-/// This PointerType is the result type of the call's only bitcast use.
-/// If there is no unique bitcast use, then return NULL.
-const PointerType* llvm::getMallocType(const CallInst* CI) {
- assert(isMalloc(CI) && "GetMallocType and not malloc call");
-
- const BitCastInst* BCI = NULL;
+/// 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();
+ for (Value::const_use_iterator UI = CI->use_begin(), E = CI->use_end();
UI != E; )
- if ((BCI = dyn_cast<BitCastInst>(cast<Instruction>(*UI++))))
- break;
+ if (const BitCastInst *BCI = dyn_cast<BitCastInst>(*UI++)) {
+ MallocType = cast<PointerType>(BCI->getDestTy());
+ NumOfBitCastUses++;
+ }
- // Malloc call has 1 bitcast use and no other uses, so type is the bitcast's
- // destination type.
- if (BCI && CI->hasOneUse())
- return cast<PointerType>(BCI->getDestTy());
+ // 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 (!BCI)
+ if (NumOfBitCastUses == 0)
return cast<PointerType>(CI->getType());
// Type could not be determined.
return NULL;
}
-/// getMallocAllocatedType - Returns the Type allocated by malloc call. This
-/// Type is the result type of the call's only bitcast use. If there is no
-/// unique bitcast use, then return NULL.
-const Type* llvm::getMallocAllocatedType(const CallInst* CI) {
- const PointerType* PT = getMallocType(CI);
+/// 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;
}
-/// isSafeToGetMallocArraySize - Returns true if the array size of a malloc can
-/// be determined. It can be determined in these 3 cases of malloc codegen:
-/// 1. non-array malloc: The malloc's size argument is a constant and equals the /// size of the type being malloced.
-/// 2. array malloc: This is a malloc call with one bitcast use AND the malloc
-/// call's size argument is a constant multiple of the size of the malloced
-/// type.
-/// 3. array malloc: This is a malloc call with one bitcast use AND the malloc
-/// call's size argument is the result of a multiplication by the size of the
-/// malloced type.
-/// Otherwise returns false.
-static bool isSafeToGetMallocArraySize(const CallInst *CI,
- LLVMContext &Context,
- const TargetData* TD) {
- if (!CI)
- return false;
-
- // Type must be known to determine array size.
- const Type* T = getMallocAllocatedType(CI);
- if (!T) return false;
-
- Value* MallocArg = CI->getOperand(1);
- Constant *ElementSize = ConstantExpr::getSizeOf(T);
- ElementSize = ConstantExpr::getTruncOrBitCast(ElementSize,
- MallocArg->getType());
-
- // First, check if it is a non-array malloc.
- if (isa<ConstantExpr>(MallocArg) && (MallocArg == ElementSize))
- return true;
-
- // Second, check if it can be determined that this is an array malloc.
- return isArrayMallocHelper(CI, Context, TD);
-}
-
-/// isConstantOne - Return true only if val is constant int 1.
-static bool isConstantOne(Value *val) {
- return isa<ConstantInt>(val) && cast<ConstantInt>(val)->isOne();
-}
-
-/// getMallocArraySize - Returns the array size of a malloc call. For array
-/// mallocs, the size is computated in 1 of 3 ways:
-/// 1. If the element type is of size 1, then array size is the argument to
-/// malloc.
-/// 2. Else if the malloc's argument is a constant, the array size is that
-/// argument divided by the element type's size.
-/// 3. Else the malloc argument must be a multiplication and the array size is
-/// the first operand of the multiplication.
-/// For non-array mallocs, the computed size is constant 1.
-/// This function returns NULL for all mallocs whose array size cannot be
+/// 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, LLVMContext &Context,
- const TargetData* TD) {
- if (!isSafeToGetMallocArraySize(CI, Context, TD))
- return NULL;
-
- // Match CreateMalloc's use of constant 1 array-size for non-array mallocs.
- if (!isArrayMalloc(CI, Context, TD))
- return ConstantInt::get(CI->getOperand(1)->getType(), 1);
-
- Value* MallocArg = CI->getOperand(1);
- assert(getMallocAllocatedType(CI) && "getMallocArraySize and no type");
- Constant *ElementSize = ConstantExpr::getSizeOf(getMallocAllocatedType(CI));
- ElementSize = ConstantExpr::getTruncOrBitCast(ElementSize,
- MallocArg->getType());
-
- Constant* CO = dyn_cast<Constant>(MallocArg);
- BinaryOperator* BO = dyn_cast<BinaryOperator>(MallocArg);
- assert((isConstantOne(ElementSize) || CO || BO) &&
- "getMallocArraySize and malformed malloc IR");
-
- if (isConstantOne(ElementSize))
- return MallocArg;
-
- if (CO)
- return CO->getOperand(0);
-
- // TODO: Detect case where MallocArg mul has been transformed to shl.
-
- assert(BO && "getMallocArraySize not constant but not multiplication either");
- return BO->getOperand(0);
+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 the value is a call to the builtin free()
-bool llvm::isFreeCall(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 CallInst *CI = dyn_cast<CallInst>(I);
if (!CI)
- return false;
-
- const Module* M = CI->getParent()->getParent()->getParent();
- Function *FreeFunc = M->getFunction("free");
-
- if (CI->getOperand(0) != FreeFunc)
- return false;
+ return 0;
+ Function *Callee = CI->getCalledFunction();
+ if (Callee == 0 || !Callee->isDeclaration() || Callee->getName() != "free")
+ return 0;
// Check free prototype.
// FIXME: workaround for PR5130, this will be obsolete when a nobuiltin
// attribute will exist.
- const FunctionType *FTy = FreeFunc->getFunctionType();
- if (FTy->getReturnType() != Type::getVoidTy(M->getContext()))
- return false;
+ const FunctionType *FTy = Callee->getFunctionType();
+ if (!FTy->getReturnType()->isVoidTy())
+ return 0;
if (FTy->getNumParams() != 1)
- return false;
- if (FTy->param_begin()->get() != Type::getInt8PtrTy(M->getContext()))
- return false;
+ return 0;
+ if (FTy->param_begin()->get() != Type::getInt8PtrTy(Callee->getContext()))
+ return 0;
- return true;
+ return CI;
}