From 3acfb58b178d25b0671cbfb4fb20194e62b01a98 Mon Sep 17 00:00:00 2001
From: Rafael Espindola <rafael.espindola@gmail.com>
Date: Wed, 4 Sep 2013 14:05:09 +0000
Subject: [PATCH] Fix linking of unnamed_addr.

This was regression from r134829. When linking we have to be conservative. If
one of the symbols has a significant address, then the result should have it
too.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@189935 91177308-0d34-0410-b5e6-96231b3b80d8
---
 lib/Linker/LinkModules.cpp     | 8 ++++++--
 test/Linker/unnamed-addr1-a.ll | 6 +++---
 2 files changed, 9 insertions(+), 5 deletions(-)

diff --git a/lib/Linker/LinkModules.cpp b/lib/Linker/LinkModules.cpp
index f32211245f6..ab37b8b12fb 100644
--- a/lib/Linker/LinkModules.cpp
+++ b/lib/Linker/LinkModules.cpp
@@ -746,6 +746,7 @@ bool ModuleLinker::linkAppendingVarProto(GlobalVariable *DstGV,
 bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
   GlobalValue *DGV = getLinkedToGlobal(SGV);
   llvm::Optional<GlobalValue::VisibilityTypes> NewVisibility;
+  bool HasUnnamedAddr = SGV->hasUnnamedAddr();
 
   if (DGV) {
     // Concatenation of appending linkage variables is magic and handled later.
@@ -755,6 +756,7 @@ bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
     // Determine whether linkage of these two globals follows the source
     // module's definition or the destination module's definition.
     GlobalValue::LinkageTypes NewLinkage = GlobalValue::InternalLinkage;
+    HasUnnamedAddr = HasUnnamedAddr && DGV->hasUnnamedAddr();
     GlobalValue::VisibilityTypes NV;
     bool LinkFromSrc = false;
     if (getLinkageResult(DGV, SGV, NewLinkage, NV, LinkFromSrc))
@@ -768,10 +770,11 @@ bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
       if (GlobalVariable *DGVar = dyn_cast<GlobalVariable>(DGV))
         if (DGVar->isDeclaration() && SGV->isConstant() && !DGVar->isConstant())
           DGVar->setConstant(true);
-      
-      // Set calculated linkage and visibility.
+
+      // Set calculated linkage, visibility and unnamed_addr.
       DGV->setLinkage(NewLinkage);
       DGV->setVisibility(*NewVisibility);
+      DGV->setUnnamedAddr(HasUnnamedAddr);
 
       // Make sure to remember this mapping.
       ValueMap[SGV] = ConstantExpr::getBitCast(DGV,TypeMap.get(SGV->getType()));
@@ -797,6 +800,7 @@ bool ModuleLinker::linkGlobalProto(GlobalVariable *SGV) {
   copyGVAttributes(NewDGV, SGV);
   if (NewVisibility)
     NewDGV->setVisibility(*NewVisibility);
+  NewDGV->setUnnamedAddr(HasUnnamedAddr);
 
   if (DGV) {
     DGV->replaceAllUsesWith(ConstantExpr::getBitCast(NewDGV, DGV->getType()));
diff --git a/test/Linker/unnamed-addr1-a.ll b/test/Linker/unnamed-addr1-a.ll
index e9c03ee1424..1ddac9ccc02 100644
--- a/test/Linker/unnamed-addr1-a.ll
+++ b/test/Linker/unnamed-addr1-a.ll
@@ -10,15 +10,15 @@
 @c = common unnamed_addr global i32 0
 ; CHECK: @c = common unnamed_addr global i32 0
 @d = external global i32
-; CHECK: @d = unnamed_addr global i32 42
+; CHECK: @d = global i32 42
 @e = external unnamed_addr global i32
 ; CHECK: @e = unnamed_addr global i32 42
 @f = weak global i32 42
-; CHECK: @f = unnamed_addr global i32 42
+; CHECK: @f = global i32 42
 
 ; Other file has non-unnamed_addr definition
 @g = common unnamed_addr global i32 0
-; CHECK: @g = common unnamed_addr global i32 0
+; CHECK: @g = common global i32 0
 @h = external global i32
 ; CHECK: @h = global i32 42
 @i = external unnamed_addr global i32