// Returns the ThenBlock's terminator.
static BranchInst *splitBlockAndInsertIfThen(Value *Cmp) {
Instruction *SplitBefore = cast<Instruction>(Cmp)->getNextNode();
+
+ // Create three basic blocks, with the middle block empty, by splitting twice.
BasicBlock *Head = SplitBefore->getParent();
- BasicBlock *Tail = Head->splitBasicBlock(SplitBefore);
+ BasicBlock *Then = Head->splitBasicBlock(SplitBefore);
+ BasicBlock *Tail = Then->splitBasicBlock(SplitBefore);
+
TerminatorInst *HeadOldTerm = Head->getTerminator();
- 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, ThenBlock);
- return CheckTerm;
+ IRBuilder<>(HeadOldTerm).CreateCondBr(Cmp, Then, Tail);
+ HeadOldTerm->eraseFromParent();
+
+ return cast<BranchInst>(Then->getTerminator());
}
Value *AddressSanitizer::memToShadow(Value *Shadow, IRBuilder<> &IRB) {
Value *Cmp = IRB.CreateICmpNE(ShadowValue, CmpVal);
Instruction *CheckTerm = splitBlockAndInsertIfThen(Cmp);
- IRBuilder<> IRB2(CheckTerm);
+ IRB.SetInsertPoint(CheckTerm);
size_t Granularity = 1 << MappingScale;
if (TypeSize < 8 * Granularity) {
// Addr & (Granularity - 1)
- Value *LastAccessedByte = IRB2.CreateAnd(
+ Value *LastAccessedByte = IRB.CreateAnd(
AddrLong, ConstantInt::get(IntptrTy, Granularity - 1));
// (Addr & (Granularity - 1)) + size - 1
if (TypeSize / 8 > 1)
- LastAccessedByte = IRB2.CreateAdd(
+ LastAccessedByte = IRB.CreateAdd(
LastAccessedByte, ConstantInt::get(IntptrTy, TypeSize / 8 - 1));
// (uint8_t) ((Addr & (Granularity-1)) + size - 1)
- LastAccessedByte = IRB2.CreateIntCast(
+ LastAccessedByte = IRB.CreateIntCast(
LastAccessedByte, IRB.getInt8Ty(), false);
// ((uint8_t) ((Addr & (Granularity-1)) + size - 1)) >= ShadowValue
- Value *Cmp2 = IRB2.CreateICmpSGE(LastAccessedByte, ShadowValue);
+ Value *Cmp2 = IRB.CreateICmpSGE(LastAccessedByte, ShadowValue);
CheckTerm = splitBlockAndInsertIfThen(Cmp2);
+ IRB.SetInsertPoint(CheckTerm);
}
- IRBuilder<> IRB1(CheckTerm);
- Instruction *Crash = generateCrashCode(IRB1, AddrLong, IsWrite, TypeSize);
+ Instruction *Crash = generateCrashCode(IRB, AddrLong, IsWrite, TypeSize);
Crash->setDebugLoc(OrigIns->getDebugLoc());
ReplaceInstWithInst(CheckTerm, new UnreachableInst(*C));
}
; CHECK: icmp ne i8
; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
;
-; The actual load comes next because ASan adds the last instrumentation block
-; to the end of the function.
-; CHECK: %tmp1 = load i32* %a
-; CHECK: ret i32 %tmp1
-;
; First instrumentation block refines the shadow test.
; CHECK: and i64 %[[LOAD_ADDR]], 7
; CHECK: add i64 %{{.*}}, 3
; CHECK: icmp sge i8 %{{.*}}, %[[LOAD_SHADOW]]
; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
;
-; Final instrumentation block reports the error.
+; Second instrumentation block reports the error.
; CHECK: call void @__asan_report_load4(i64 %[[LOAD_ADDR]]) noreturn
; CHECK: unreachable
+;
+; Finally the instrumented load.
+; CHECK: %tmp1 = load i32* %a
+; CHECK: ret i32 %tmp1
entry:
%tmp1 = load i32* %a
; CHECK: icmp ne i8
; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
;
-; The actual store comes next because ASan adds the last instrumentation block
-; to the end of the function.
-; CHECK: store i32 42, i32* %a
-; CHECK: ret void
-;
; First instrumentation block refines the shadow test.
; CHECK: and i64 %[[STORE_ADDR]], 7
; CHECK: add i64 %{{.*}}, 3
; CHECK: icmp sge i8 %{{.*}}, %[[STORE_SHADOW]]
; CHECK: br i1 %{{.*}}, label %{{.*}}, label %{{.*}}
;
-; Final instrumentation block reports the error.
+; Second instrumentation block reports the error.
; CHECK: call void @__asan_report_store4(i64 %[[STORE_ADDR]]) noreturn
; CHECK: unreachable
+;
+; Finally the instrumented store.
+; CHECK: store i32 42, i32* %a
+; CHECK: ret void
entry:
store i32 42, i32* %a