DebugInfo: New metadata representation for global variables.

This patch reverses the edge from DIGlobalVariable to GlobalVariable.
This will allow us to more easily preserve debug info metadata when
manipulating global variables.

Fixes PR30362. A program for upgrading test cases is attached to that
bug.

Differential Revision: http://reviews.llvm.org/D20147

llvm-svn: 281284

1 files changed, 5 insertions, 3 deletions

diff --git a/llvm/lib/Linker/IRMover.cpp b/llvm/lib/Linker/IRMover.cpp
index c02abd7e3aca..5a00aae7e8a2 100644
--- a/llvm/lib/Linker/IRMover.cpp
+++ b/llvm/lib/Linker/IRMover.cpp
@@ -465,7 +465,7 @@ class IRLinker {
 
   Error linkModuleFlagsMetadata();
 
-  void linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src);
+  void linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src);
   Error linkFunctionBody(Function &Dst, Function &Src);
   void linkAliasBody(GlobalAlias &Dst, GlobalAlias &Src);
   Error linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src);
@@ -942,7 +942,9 @@ Expected<Constant *> IRLinker::linkGlobalValueProto(GlobalValue *SGV,
 
 /// Update the initializers in the Dest module now that all globals that may be
 /// referenced are in Dest.
-void IRLinker::linkGlobalInit(GlobalVariable &Dst, GlobalVariable &Src) {
+void IRLinker::linkGlobalVariable(GlobalVariable &Dst, GlobalVariable &Src) {
+  Dst.copyMetadata(&Src, 0);
+
   // Figure out what the initializer looks like in the dest module.
   Mapper.scheduleMapGlobalInitializer(Dst, *Src.getInitializer());
 }
@@ -985,7 +987,7 @@ Error IRLinker::linkGlobalValueBody(GlobalValue &Dst, GlobalValue &Src) {
   if (auto *F = dyn_cast<Function>(&Src))
     return linkFunctionBody(cast<Function>(Dst), *F);
   if (auto *GVar = dyn_cast<GlobalVariable>(&Src)) {
-    linkGlobalInit(cast<GlobalVariable>(Dst), *GVar);
+    linkGlobalVariable(cast<GlobalVariable>(Dst), *GVar);
     return Error::success();
   }
   linkAliasBody(cast<GlobalAlias>(Dst), cast<GlobalAlias>(Src));