From e71d60d2c948bef21443c3370a9922a2f58bcc3a Mon Sep 17 00:00:00 2001
From: John McCall <rjmccall@apple.com>
Date: Tue, 5 Oct 2010 20:48:15 +0000
Subject: Teach PopCleanupBlock to correctly handle the possibility of
 branching through a EH-only cleanup as part of a fallthrough branch-through. 
 That this happens for this test case is actually a separate bug.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@115668 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/CodeGen/CodeGenFunction.cpp | 23 ++++++++++++++---------
 1 file changed, 14 insertions(+), 9 deletions(-)

(limited to 'lib/CodeGen/CodeGenFunction.cpp')

diff --git a/lib/CodeGen/CodeGenFunction.cpp b/lib/CodeGen/CodeGenFunction.cpp
index 043195cecf..56dccc1c0a 100644
--- a/lib/CodeGen/CodeGenFunction.cpp
+++ b/lib/CodeGen/CodeGenFunction.cpp
@@ -846,26 +846,31 @@ void CodeGenFunction::PopCleanupBlock(bool FallthroughIsBranchThrough) {
   llvm::BasicBlock *FallthroughSource = Builder.GetInsertBlock();
   bool HasFallthrough = (FallthroughSource != 0 && IsActive);
 
-  // As a kindof crazy internal case, branch-through fall-throughs
-  // leave the insertion point set to the end of the last cleanup.
+  // Branch-through fall-throughs leave the insertion point set to the
+  // end of the last cleanup, which points to the current scope.  The
+  // rest of IR gen doesn't need to worry about this; it only happens
+  // during the execution of PopCleanupBlocks().
   bool HasPrebranchedFallthrough =
     (FallthroughSource && FallthroughSource->getTerminator());
 
+  // If this is a normal cleanup, then having a prebranched
+  // fallthrough implies that the fallthrough source unconditionally
+  // jumps here.
+  assert(!Scope.isNormalCleanup() || !HasPrebranchedFallthrough ||
+         (Scope.getNormalBlock() &&
+          FallthroughSource->getTerminator()->getSuccessor(0)
+            == Scope.getNormalBlock()));
+
   bool RequiresNormalCleanup = false;
   if (Scope.isNormalCleanup() &&
       (HasFixups || HasExistingBranches || HasFallthrough)) {
     RequiresNormalCleanup = true;
   }
 
-  assert(!HasPrebranchedFallthrough || RequiresNormalCleanup || !IsActive);
-  assert(!HasPrebranchedFallthrough ||
-         (Scope.isNormalCleanup() && Scope.getNormalBlock() &&
-          FallthroughSource->getTerminator()->getSuccessor(0)
-            == Scope.getNormalBlock()));
-
   // Even if we don't need the normal cleanup, we might still have
   // prebranched fallthrough to worry about.
-  if (!RequiresNormalCleanup && HasPrebranchedFallthrough) {
+  if (Scope.isNormalCleanup() && !RequiresNormalCleanup &&
+      HasPrebranchedFallthrough) {
     assert(!IsActive);
 
     llvm::BasicBlock *NormalEntry = Scope.getNormalBlock();
-- 
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