From: Mike Stump <mrs@apple.com>
Date: Sat, 7 Feb 2009 20:09:00 +0000 (+0000)
Subject: Ensure that we don't miscodegen if vlas creap into the top of the for.
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=501af1f721d837a565b947bf194a3476db32d926;p=clang

Ensure that we don't miscodegen if vlas creap into the top of the for.
This will allow us to generate break and continue even if vlas are
involved without worry that we'll silently generate bad code.


git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@64028 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/CodeGen/CGObjC.cpp b/lib/CodeGen/CGObjC.cpp
index d62cfdc306..a116316641 100644
--- a/lib/CodeGen/CGObjC.cpp
+++ b/lib/CodeGen/CGObjC.cpp
@@ -446,6 +446,10 @@ void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S)
   llvm::BasicBlock *LoopStart = createBasicBlock("loopstart");
   EmitBlock(LoopStart);
 
+  // We want to ensure there are no vlas between here and when we
+  // push the break and continue context below.
+  llvm::Value *saveStackDepth = StackDepth;
+
   llvm::Value *CounterPtr = CreateTempAlloca(UnsignedLongLTy, "counter.ptr");
   Builder.CreateStore(Zero, CounterPtr);
   
@@ -515,6 +519,8 @@ void CodeGenFunction::EmitObjCForCollectionStmt(const ObjCForCollectionStmt &S)
   llvm::BasicBlock *LoopEnd = createBasicBlock("loopend");
   llvm::BasicBlock *AfterBody = createBasicBlock("afterbody");
   
+  assert (StackDepth == saveStackDepth && "vla unhandled in for");
+
   BreakContinuePush(LoopEnd, AfterBody);
 
   EmitStmt(S.getBody());