From 1d1a2976d5a49a4243d1b1add919edc6d8ba1430 Mon Sep 17 00:00:00 2001
From: David Majnemer <david.majnemer@gmail.com>
Date: Tue, 27 Oct 2015 22:43:56 +0000
Subject: [PATCH] [SimplifyCFG] Don't DCE catchret because the successor is
 unreachable

CatchReturnInst has side-effects: it runs a destructor.  This destructor
could conceivably run forever/call exit/etc. and should not be removed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@251461 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Transforms/Utils/SimplifyCFG.cpp          |  3 +--
 .../SimplifyCFG/wineh-unreachable.ll          | 20 +++++++++++++++++++
 2 files changed, 21 insertions(+), 2 deletions(-)

diff --git a/lib/Transforms/Utils/SimplifyCFG.cpp b/lib/Transforms/Utils/SimplifyCFG.cpp
index e435537c3a7..69c08e55283 100644
--- a/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -3178,8 +3178,7 @@ bool SimplifyCFGOpt::SimplifyUnreachable(UnreachableInst *UI) {
                isa<CatchEndPadInst>(TI) || isa<TerminatePadInst>(TI)) {
       removeUnwindEdge(TI->getParent());
       Changed = true;
-    } else if (isa<CleanupReturnInst>(TI) || isa<CleanupEndPadInst>(TI) ||
-               isa<CatchReturnInst>(TI)) {
+    } else if (isa<CleanupReturnInst>(TI) || isa<CleanupEndPadInst>(TI)) {
       new UnreachableInst(TI->getContext(), TI);
       TI->eraseFromParent();
       Changed = true;
diff --git a/test/Transforms/SimplifyCFG/wineh-unreachable.ll b/test/Transforms/SimplifyCFG/wineh-unreachable.ll
index 7db883b2412..31d567f6492 100644
--- a/test/Transforms/SimplifyCFG/wineh-unreachable.ll
+++ b/test/Transforms/SimplifyCFG/wineh-unreachable.ll
@@ -86,3 +86,23 @@ unreachable.unwind:
   cleanuppad []
   unreachable
 }
+
+; CHECK-LABEL: define void @test5()
+define void @test5() personality i8* bitcast (void ()* @Personality to i8*) {
+entry:
+  invoke void @f()
+          to label %exit unwind label %catch.pad
+
+catch.pad:
+  %catch = catchpad []
+          to label %catch.body unwind label %catch.end
+
+catch.body:
+  catchret %catch to label %exit
+
+catch.end:
+  catchendpad unwind to caller
+
+exit:
+  unreachable
+}
-- 
2.34.1