[Cloning] Copy metadata of global declarations

We have modules with metadata on declarations, and out-of-tree passes
use that metadata, and we need to clone those modules. We really expect
such metadata is kept during the clone operation.

Reviewed by: arsenm, aprantl

Differential Revision: https://reviews.llvm.org/D93451

1 files changed, 8 insertions, 7 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneModule.cpp b/llvm/lib/Transforms/Utils/CloneModule.cpp
index 2c8c3ab..a6327bb 100644
--- a/llvm/lib/Transforms/Utils/CloneModule.cpp
+++ b/llvm/lib/Transforms/Utils/CloneModule.cpp
@@ -117,10 +117,17 @@ std::unique_ptr<Module> llvm::CloneModule(
   //
   for (Module::const_global_iterator I = M.global_begin(), E = M.global_end();
        I != E; ++I) {
+    GlobalVariable *GV = cast<GlobalVariable>(VMap[&*I]);
+
+    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
+    I->getAllMetadata(MDs);
+    for (auto MD : MDs)
+      GV->addMetadata(MD.first,
+                      *MapMetadata(MD.second, VMap, RF_MoveDistinctMDs));
+
     if (I->isDeclaration())
       continue;
 
-    GlobalVariable *GV = cast<GlobalVariable>(VMap[&*I]);
     if (!ShouldCloneDefinition(&*I)) {
       // Skip after setting the correct linkage for an external reference.
       GV->setLinkage(GlobalValue::ExternalLinkage);
@@ -129,12 +136,6 @@ std::unique_ptr<Module> llvm::CloneModule(
     if (I->hasInitializer())
       GV->setInitializer(MapValue(I->getInitializer(), VMap));
 
-    SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
-    I->getAllMetadata(MDs);
-    for (auto MD : MDs)
-      GV->addMetadata(MD.first,
-                      *MapMetadata(MD.second, VMap, RF_MoveDistinctMDs));
-
     copyComdat(GV, &*I);
   }