Preserve extern_weak linkage in CloneModule.

Only force "extern" linkage if the function used to be a definition
in the source module. Declarations keep their original linkage.

llvm-svn: 265043

1 files changed, 15 insertions, 10 deletions

diff --git a/llvm/lib/Transforms/Utils/CloneModule.cpp b/llvm/lib/Transforms/Utils/CloneModule.cpp
index 929f51b..6fb86da 100644
--- a/llvm/lib/Transforms/Utils/CloneModule.cpp
+++ b/llvm/lib/Transforms/Utils/CloneModule.cpp
@@ -109,6 +109,9 @@ std::unique_ptr<Module> llvm::CloneModule(
   //
   for (Module::const_global_iterator I = M->global_begin(), E = M->global_end();
        I != E; ++I) {
+    if (I->isDeclaration())
+      continue;
+
     GlobalVariable *GV = cast<GlobalVariable>(VMap[&*I]);
     if (!ShouldCloneDefinition(&*I)) {
       // Skip after setting the correct linkage for an external reference.
@@ -122,6 +125,9 @@ std::unique_ptr<Module> llvm::CloneModule(
   // Similarly, copy over function bodies now...
   //
   for (Module::const_iterator I = M->begin(), E = M->end(); I != E; ++I) {
+    if (I->isDeclaration())
+      continue;
+
     Function *F = cast<Function>(VMap[&*I]);
     if (!ShouldCloneDefinition(&*I)) {
       // Skip after setting the correct linkage for an external reference.
@@ -130,18 +136,17 @@ std::unique_ptr<Module> llvm::CloneModule(
       F->setPersonalityFn(nullptr);
       continue;
     }
-    if (!I->isDeclaration()) {
-      Function::arg_iterator DestI = F->arg_begin();
-      for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
-           ++J) {
-        DestI->setName(J->getName());
-        VMap[&*J] = &*DestI++;
-      }
-
-      SmallVector<ReturnInst*, 8> Returns;  // Ignore returns cloned.
-      CloneFunctionInto(F, &*I, VMap, /*ModuleLevelChanges=*/true, Returns);
+
+    Function::arg_iterator DestI = F->arg_begin();
+    for (Function::const_arg_iterator J = I->arg_begin(); J != I->arg_end();
+         ++J) {
+      DestI->setName(J->getName());
+      VMap[&*J] = &*DestI++;
     }
 
+    SmallVector<ReturnInst *, 8> Returns; // Ignore returns cloned.
+    CloneFunctionInto(F, &*I, VMap, /*ModuleLevelChanges=*/true, Returns);
+
     if (I->hasPersonalityFn())
       F->setPersonalityFn(MapValue(I->getPersonalityFn(), VMap));
   }