From: Michael Gottesman <mgottesman@apple.com>
Date: Mon, 8 Jul 2013 23:30:23 +0000 (+0000)
Subject: [objc-arc] Fix assertion in EraseInstruction so that noop on null calls when passed... 
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=a75b293e4fa702d3e233839dc347ebf565be2d4d;p=oota-llvm.git

[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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@185885 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/Transforms/ObjCARC/ObjCARC.h b/lib/Transforms/ObjCARC/ObjCARC.h
index 39670f339e9..1462e85991a 100644
--- a/lib/Transforms/ObjCARC/ObjCARC.h
+++ b/lib/Transforms/ObjCARC/ObjCARC.h
@@ -286,7 +286,9 @@ static inline void EraseInstruction(Instruction *CI) {
 
   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);
   }