Add an assertion to verify a container is non-empty before calling 'back()'
This would've helped stabilize/deflake some failures that were seen
after some recent changes.
llvm-svn: 224943
diff --git a/clang/lib/CodeGen/CGDebugInfo.cpp b/clang/lib/CodeGen/CGDebugInfo.cpp
index 03f26df..37a0b8f 100644
--- a/clang/lib/CodeGen/CGDebugInfo.cpp
+++ b/clang/lib/CodeGen/CGDebugInfo.cpp
@@ -2627,6 +2627,7 @@
// Don't bother if things are the same as last time.
SourceManager &SM = CGM.getContext().getSourceManager();
+ assert(!LexicalBlockStack.empty());
if (CurLoc == PrevLoc ||
SM.getExpansionLoc(CurLoc) == SM.getExpansionLoc(PrevLoc))
// New Builder may not be in sync with CGDebugInfo.