[llvm] r277067 - maned

[Vitaly Buka via llvm-commits]

Author: vitalybuka
Date: Thu Jul 28 17:50:45 2016
New Revision: 277067

URL: http://llvm.org/viewvc/llvm-project?rev=277067&view=rev
Log:
maned

Added:
    llvm/trunk/test/Transforms/InstCombine/lifetime-asan.ll
Modified:
    llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp

Modified: llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp?rev=277067&r1=277066&r2=277067&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp (original)
+++ llvm/trunk/lib/Transforms/InstCombine/InstCombineCalls.cpp Thu Jul 28 17:50:45 2016
@@ -1211,10 +1211,6 @@ static bool removeTriviallyEmptyRange(In
                                       unsigned EndID, InstCombiner &IC) {
   assert(I.getIntrinsicID() == StartID &&
          "Start intrinsic does not have expected ID");
-  // Even if the range is empty asan need to poison memory to detect invalid
-  // access latter.
-  if (ClUseAfterScope)
-    return false;
   BasicBlock::iterator BI(I), BE(I.getParent()->end());
   for (++BI; BI != BE; ++BI) {
     if (auto *E = dyn_cast<IntrinsicInst>(BI)) {
@@ -2248,11 +2244,18 @@ Instruction *InstCombiner::visitCallInst
       return eraseInstFromFunction(CI);
     break;
   }
-  case Intrinsic::lifetime_start:
+  case Intrinsic::lifetime_start: {
+    const Function *func = II->getFunction();
+    // Asan needs to poison memory to detect invalid access possible even for
+    // empty lifetime range.
+    if (func && func->hasFnAttribute(Attribute::SanitizeAddress))
+      break;
+
     if (removeTriviallyEmptyRange(*II, Intrinsic::lifetime_start,
                                   Intrinsic::lifetime_end, *this))
       return nullptr;
     break;
+  }
   case Intrinsic::assume: {
     Value *IIOperand = II->getArgOperand(0);
     // Remove an assume if it is immediately followed by an identical assume.
@@ -2483,7 +2486,6 @@ static IntrinsicInst *findInitTrampoline
 
 /// Improvements for call and invoke instructions.
 Instruction *InstCombiner::visitCallSite(CallSite CS) {
-
   if (isAllocLikeFn(CS.getInstruction(), TLI))
     return visitAllocSite(*CS.getInstruction());
 

Added: llvm/trunk/test/Transforms/InstCombine/lifetime-asan.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstCombine/lifetime-asan.ll?rev=277067&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/InstCombine/lifetime-asan.ll (added)
+++ llvm/trunk/test/Transforms/InstCombine/lifetime-asan.ll Thu Jul 28 17:50:45 2016
@@ -0,0 +1,37 @@
+; RUN: opt < %s -instcombine -S | FileCheck %s
+
+declare void @llvm.lifetime.start(i64, i8* nocapture)
+declare void @llvm.lifetime.end(i64, i8* nocapture)
+declare void @foo(i8* nocapture)
+
+define void @asan() sanitize_address {
+entry:
+  ; CHECK-LABEL: @asan(
+  %text = alloca [1 x i8], align 1
+  %0 = getelementptr inbounds [1 x i8], [1 x i8]* %text, i64 0, i64 0
+
+  call void @llvm.lifetime.start(i64 1, i8* %0)
+  call void @llvm.lifetime.end(i64 1, i8* %0)
+  ; CHECK: call void @llvm.lifetime.start
+  ; CHECK-NEXT: call void @llvm.lifetime.end
+
+  call void @foo(i8* %0) ; Keep alloca alive
+
+  ret void
+}
+
+
+define void @no_asan() {
+entry:
+  ; CHECK-LABEL: @no_asan(
+  %text = alloca [1 x i8], align 1
+  %0 = getelementptr inbounds [1 x i8], [1 x i8]* %text, i64 0, i64 0
+
+  call void @llvm.lifetime.start(i64 1, i8* %0)
+  call void @llvm.lifetime.end(i64 1, i8* %0)
+  ; CHECK-NO: call void @llvm.lifetime
+
+  call void @foo(i8* %0) ; Keep alloca alive
+
+  ret void
+}