[asan] small code simplification

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159522 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Kostya Serebryany 2012-07-02 11:42:29 +00:00
parent 7e621f3242
commit 56139bc493

View File

@ -157,7 +157,6 @@ struct AddressSanitizer : public ModulePass {
bool poisonStackInFunction(Module &M, Function &F);
virtual bool runOnModule(Module &M);
bool insertGlobalRedzones(Module &M);
BranchInst *splitBlockAndInsertIfThen(Instruction *SplitBefore, Value *Cmp);
static char ID; // Pass identification, replacement for typeid
private:
@ -220,29 +219,27 @@ static GlobalVariable *createPrivateGlobalForString(Module &M, StringRef Str) {
// Split the basic block and insert an if-then code.
// Before:
// Head
// SplitBefore
// Cmp
// Tail
// After:
// Head
// if (Cmp)
// NewBasicBlock
// SplitBefore
// ThenBlock
// Tail
//
// Returns the NewBasicBlock's terminator.
BranchInst *AddressSanitizer::splitBlockAndInsertIfThen(
Instruction *SplitBefore, Value *Cmp) {
// Returns the ThenBlock's terminator.
static BranchInst *splitBlockAndInsertIfThen(Value *Cmp) {
Instruction *SplitBefore = cast<Instruction>(Cmp)->getNextNode();
BasicBlock *Head = SplitBefore->getParent();
BasicBlock *Tail = Head->splitBasicBlock(SplitBefore);
TerminatorInst *HeadOldTerm = Head->getTerminator();
BasicBlock *NewBasicBlock =
BasicBlock::Create(*C, "", Head->getParent());
BranchInst *HeadNewTerm = BranchInst::Create(/*ifTrue*/NewBasicBlock,
/*ifFalse*/Tail,
Cmp);
LLVMContext &C = Head->getParent()->getParent()->getContext();
BasicBlock *ThenBlock = BasicBlock::Create(C, "", Head->getParent());
BranchInst *HeadNewTerm =
BranchInst::Create(/*ifTrue*/ThenBlock, /*ifFalse*/Tail, Cmp);
ReplaceInstWithInst(HeadOldTerm, HeadNewTerm);
BranchInst *CheckTerm = BranchInst::Create(Tail, NewBasicBlock);
BranchInst *CheckTerm = BranchInst::Create(Tail, ThenBlock);
return CheckTerm;
}
@ -291,8 +288,8 @@ bool AddressSanitizer::instrumentMemIntrinsic(MemIntrinsic *MI) {
IRBuilder<> IRB(InsertBefore);
Value *Cmp = IRB.CreateICmpNE(Length,
Constant::getNullValue(Length->getType()));
InsertBefore = splitBlockAndInsertIfThen(InsertBefore, Cmp);
Constant::getNullValue(Length->getType()));
InsertBefore = splitBlockAndInsertIfThen(Cmp);
}
instrumentMemIntrinsicParam(MI, Dst, Length, InsertBefore, true);
@ -389,8 +386,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
Instruction *CheckTerm = splitBlockAndInsertIfThen(
cast<Instruction>(Cmp)->getNextNode(), Cmp);
Instruction *CheckTerm = splitBlockAndInsertIfThen(Cmp);
IRBuilder<> IRB2(CheckTerm);
size_t Granularity = 1 << MappingScale;
@ -408,7 +404,7 @@ void AddressSanitizer::instrumentAddress(Instruction *OrigIns,
// ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
Value *Cmp2 = IRB2.CreateICmpSGE(LastAccessedByte, ShadowValue);
CheckTerm = splitBlockAndInsertIfThen(CheckTerm, Cmp2);
CheckTerm = splitBlockAndInsertIfThen(Cmp2);
}
IRBuilder<> IRB1(CheckTerm);