[llvm] r312266 - [ObjCARC] Pass the correct BasicBlock to fix assertion failure.

[Akira Hatanaka via llvm-commits]

Author: ahatanak
Date: Thu Aug 31 11:27:47 2017
New Revision: 312266

URL: http://llvm.org/viewvc/llvm-project?rev=312266&view=rev
Log:
[ObjCARC] Pass the correct BasicBlock to fix assertion failure.

The BasicBlock passed to FindPredecessorRetainWithSafePath should be the
parent block of Autorelease. This fixes a crash that occurs in
FindDependencies when StartInst is not in StartBB.

rdar://problem/33866381

Modified:
    llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
    llvm/trunk/test/Transforms/ObjCARC/rv.ll

Modified: llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp?rev=312266&r1=312265&r2=312266&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp (original)
+++ llvm/trunk/lib/Transforms/ObjCARC/ObjCARCOpts.cpp Thu Aug 31 11:27:47 2017
@@ -2027,7 +2027,8 @@ void ObjCARCOpt::OptimizeReturns(Functio
       continue;
 
     CallInst *Retain = FindPredecessorRetainWithSafePath(
-        Arg, &BB, Autorelease, DependingInstructions, Visited, PA);
+        Arg, Autorelease->getParent(), Autorelease, DependingInstructions,
+        Visited, PA);
     DependingInstructions.clear();
     Visited.clear();
 

Modified: llvm/trunk/test/Transforms/ObjCARC/rv.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/ObjCARC/rv.ll?rev=312266&r1=312265&r2=312266&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/ObjCARC/rv.ll (original)
+++ llvm/trunk/test/Transforms/ObjCARC/rv.ll Thu Aug 31 11:27:47 2017
@@ -314,6 +314,25 @@ define void @test25() {
   ret void
 }
 
+; Check that ObjCARCOpt::OptimizeReturns removes the redundant calls even when
+; they are not in the same basic block. This code used to cause an assertion
+; failure.
+
+; CHECK-LABEL: define i8* @test26()
+; CHECK: call i8* @returner()
+; CHECK-NOT:  call
+define i8* @test26() {
+bb0:
+  %v0 = call i8* @returner()
+  %v1 = tail call i8* @objc_retain(i8* %v0)
+  br label %bb1
+bb1:
+  %v2 = tail call i8* @objc_autoreleaseReturnValue(i8* %v1)
+  br label %bb2
+bb2:
+  ret i8* %v2
+}
+
 !0 = !{}
 
 ; CHECK: attributes [[NUW]] = { nounwind }