From bba25501249ff99fce930aaea0c194956aeee2b4 Mon Sep 17 00:00:00 2001
From: "Duncan P. N. Exon Smith" <dexonsmith@apple.com>
Date: Wed, 7 May 2014 22:55:46 +0000
Subject: [PATCH] LTO: Assert visibility of local linkage when merging symbols

`ModuleLinker::getLinkageResult()` shouldn't create symbols with local
linkage and non-default visibility -- in fact, symbols with local
linkage shouldn't be merged at all.  Assert to that effect.

llvm-svn: 208262
---
 lib/Linker/LinkModules.cpp | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 55654ac25d6..49c5e1cc13e 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -604,6 +604,8 @@ bool ModuleLinker::getLinkageResult(GlobalValue *Dest, const GlobalValue *Src,
 
   // Compute the visibility. We follow the rules in the System V Application
   // Binary Interface.
+  assert(!GlobalValue::isLocalLinkage(LT) &&
+         "Symbols with local linkage should not be merged");
   Vis = isLessConstraining(Src->getVisibility(), Dest->getVisibility()) ?
     Dest->getVisibility() : Src->getVisibility();
   return false;