[ThinLTO] Use new in-place symbol changes for exporting module

Due to the new in-place ThinLTO symbol handling support added in
r257174, we now invoke renameModuleForThinLTO on the current
module from within the FunctionImport pass.

Additionally, renameModuleForThinLTO no longer needs to return the
Module as it is performing the renaming in place on the one provided.

This commit will be immediately preceeded by a companion clang patch to
remove its invocation of renameModuleForThinLTO.

llvm-svn: 257181

llvm/include/llvm/Linker/Linker.h

@@ -69,8 +69,7 @@ public:
 
 /// Perform in-place global value handling on the given Module for
 /// exported local functions renamed and promoted for ThinLTO.
-std::unique_ptr<Module> renameModuleForThinLTO(std::unique_ptr<Module> M,
-                                               const FunctionInfoIndex *Index);
+bool renameModuleForThinLTO(Module &M, const FunctionInfoIndex *Index);
 
 } // End llvm namespace
 

llvm/lib/Linker/LinkModules.cpp

@@ -863,13 +863,9 @@ bool Linker::linkModules(Module &Dest, std::unique_ptr<Module> Src,
   return L.linkInModule(std::move(Src), Flags);
 }
 
-std::unique_ptr<Module>
-llvm::renameModuleForThinLTO(std::unique_ptr<Module> M,
-                             const FunctionInfoIndex *Index) {
-  ThinLTOGlobalProcessing ThinLTOProcessing(*M, Index);
-  if (ThinLTOProcessing.run())
-    return nullptr;
-  return M;
+bool llvm::renameModuleForThinLTO(Module &M, const FunctionInfoIndex *Index) {
+  ThinLTOGlobalProcessing ThinLTOProcessing(M, Index);
+  return ThinLTOProcessing.run();
 }
 
 //===----------------------------------------------------------------------===//

llvm/lib/Transforms/IPO/FunctionImport.cpp

@@ -413,14 +413,19 @@ public:
       Index = IndexPtr.get();
     }
 
+    // First we need to promote to global scope and rename any local values that
+    // are potentially exported to other modules.
+    if (renameModuleForThinLTO(M, Index)) {
+      errs() << "Error renaming module\n";
+      return false;
+    }
+
     // Perform the import now.
     auto ModuleLoader = [&M](StringRef Identifier) {
       return loadFile(Identifier, M.getContext());
     };
     FunctionImporter Importer(*Index, ModuleLoader);
     return Importer.importFunctions(M);
-
-    return false;
   }
 };
 } // anonymous namespace