[IR] Copy comdats in GlobalObject::copyAttributesFrom

This is probably correct for all uses except cross-module IR linking,
where we need to move the comdat from the source module to the
destination module.

Fixes PR27870.

Reviewers: majnemer

Differential Revision: http://reviews.llvm.org/D20631

llvm-svn: 270743

1 files changed, 1 insertions, 0 deletions

diff --git a/llvm/lib/IR/Globals.cpp b/llvm/lib/IR/Globals.cpp
index 7e8ef6526fc..3bf3cc25455 100644
--- a/llvm/lib/IR/Globals.cpp
+++ b/llvm/lib/IR/Globals.cpp
@@ -96,6 +96,7 @@ void GlobalObject::copyAttributesFrom(const GlobalValue *Src) {
   if (const auto *GV = dyn_cast<GlobalObject>(Src)) {
     setAlignment(GV->getAlignment());
     setSection(GV->getSection());
+    setComdat(const_cast<GlobalObject *>(GV)->getComdat());
   }
 }