[Cloning] Clone metadata on function declarations

Previously we missed cloning metadata on function declarations because
we don't call CloneFunctionInto() on declarations in CloneModule().

Reviewed By: dexonsmith

Differential Revision: https://reviews.llvm.org/D113812

1 files changed, 10 insertions, 2 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneModule.cpp b/llvm/lib/Transforms/Utils/CloneModule.cpp
index 200deca..57c273a 100644
--- a/llvm/lib/Transforms/Utils/CloneModule.cpp
+++ b/llvm/lib/Transforms/Utils/CloneModule.cpp
@@ -135,10 +135,18 @@ std::unique_ptr<Module> llvm::CloneModule(
   // Similarly, copy over function bodies now...
   //
   for (const Function &I : M) {
-    if (I.isDeclaration())
+    Function *F = cast<Function>(VMap[&I]);
+
+    if (I.isDeclaration()) {
+      // Copy over metadata for declarations since we're not doing it below in
+      // CloneFunctionInto().
+      SmallVector<std::pair<unsigned, MDNode *>, 1> MDs;
+      I.getAllMetadata(MDs);
+      for (auto MD : MDs)
+        F->addMetadata(MD.first, *MapMetadata(MD.second, VMap));
       continue;
+    }
 
-    Function *F = cast<Function>(VMap[&I]);
     if (!ShouldCloneDefinition(&I)) {
       // Skip after setting the correct linkage for an external reference.
       F->setLinkage(GlobalValue::ExternalLinkage);