From 0549fc2448a47515237319a2078e7bcda1c19bbe Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Fri, 15 Aug 2014 20:17:08 +0000
Subject: [PATCH] Set comdats when lazily linking functions.

We were setting the comdat when functions were copied in the initial pass, but
not when they were linked only when we found out that they are needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@215765 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Linker/LinkModules.cpp    | 5 +++++
 test/Linker/Inputs/comdat9.ll | 5 +++++
 test/Linker/comdat9.ll        | 7 +++++++
 3 files changed, 17 insertions(+)
 create mode 100644 test/Linker/Inputs/comdat9.ll
 create mode 100644 test/Linker/comdat9.ll

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index 1970e7fa069..5c26b2610b1 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -546,6 +546,11 @@ Value *ValueMaterializerTy::materializeValueFor(Value *V) {
                                   SF->getLinkage(), SF->getName(), DstM);
   copyGVAttributes(DF, SF);
 
+  if (Comdat *SC = SF->getComdat()) {
+    Comdat *DC = DstM->getOrInsertComdat(SC->getName());
+    DF->setComdat(DC);
+  }
+
   LazilyLinkFunctions.push_back(SF);
   return DF;
 }
diff --git a/test/Linker/Inputs/comdat9.ll b/test/Linker/Inputs/comdat9.ll
new file mode 100644
index 00000000000..679dbde98c3
--- /dev/null
+++ b/test/Linker/Inputs/comdat9.ll
@@ -0,0 +1,5 @@
+$c = comdat any
+@a = alias void ()* @f
+define internal void @f() comdat $c {
+  ret void
+}
diff --git a/test/Linker/comdat9.ll b/test/Linker/comdat9.ll
new file mode 100644
index 00000000000..eada8c62bef
--- /dev/null
+++ b/test/Linker/comdat9.ll
@@ -0,0 +1,7 @@
+; RUN: llvm-link %s %p/Inputs/comdat9.ll -S -o - | FileCheck %s
+
+; CHECK: $c = comdat any
+; CHECK: @a = alias void ()* @f
+; CHECK: define internal void @f() comdat $c {
+; CHECK:   ret void
+; CHECK: }