[llvm] r185885 - [objc-arc] Fix assertion in EraseInstruction so that noop on null calls when passed null do not trigger the assert.

[Michael Gottesman]

Author: mgottesman
Date: Mon Jul  8 18:30:23 2013
New Revision: 185885

URL: http://llvm.org/viewvc/llvm-project?rev=185885&view=rev
Log:
[objc-arc] Fix assertion in EraseInstruction so that noop on null calls when passed null do not trigger the assert.

The specific case of interest is when objc_retainBlock is passed null.

Modified:
    llvm/trunk/lib/Transforms/ObjCARC/ObjCARC.h

Modified: llvm/trunk/lib/Transforms/ObjCARC/ObjCARC.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARC.h?rev=185885&r1=185884&r2=185885&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARC.h (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARC.h Mon Jul  8 18:30:23 2013
@@ -286,7 +286,9 @@ static inline void EraseInstruction(Inst
 
   if (!Unused) {
     // Replace the return value with the argument.
-    assert(IsForwarding(GetBasicInstructionClass(CI)) &&
+    assert((IsForwarding(GetBasicInstructionClass(CI)) ||
+            (IsNoopOnNull(GetBasicInstructionClass(CI)) &&
+             isa<ConstantPointerNull>(OldArg))) &&
            "Can't delete non-forwarding instruction with users!");
     CI->replaceAllUsesWith(OldArg);
   }