2 files changed, 39 insertions, 12 deletions
diff --git a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
index e9633b015c1..fe0f5b7d4cb 100644
--- a/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
+++ b/llvm/lib/LTO/ThinLTOCodeGenerator.cpp
@@ -661,37 +661,52 @@ void ThinLTOCodeGenerator::crossModuleImport(Module &TheModule,
  * Compute the list of summaries needed for importing into module.
  */
 void ThinLTOCodeGenerator::gatherImportedSummariesForModule(
-    StringRef ModulePath, ModuleSummaryIndex &Index,
+    Module &TheModule, ModuleSummaryIndex &Index,
     std::map<std::string, GVSummaryMapTy> &ModuleToSummariesForIndex) {
   auto ModuleCount = Index.modulePaths().size();
+  auto ModuleIdentifier = TheModule.getModuleIdentifier();
 
   // Collect for each module the list of function it defines (GUID -> Summary).
   StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries(ModuleCount);
   Index.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
 
+  // Convert the preserved symbols set from string to GUID
+  auto GUIDPreservedSymbols = computeGUIDPreservedSymbols(
+      PreservedSymbols, Triple(TheModule.getTargetTriple()));
+
+  // Compute "dead" symbols, we don't want to import/export these!
+  computeDeadSymbolsInIndex(Index, GUIDPreservedSymbols);
+
   // Generate import/export list
   StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
   StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
   ComputeCrossModuleImport(Index, ModuleToDefinedGVSummaries, ImportLists,
                            ExportLists);
 
-  llvm::gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries,
-                                         ImportLists[ModulePath],
-                                         ModuleToSummariesForIndex);
+  llvm::gatherImportedSummariesForModule(
+      ModuleIdentifier, ModuleToDefinedGVSummaries,
+      ImportLists[ModuleIdentifier], ModuleToSummariesForIndex);
 }
 
 /**
  * Emit the list of files needed for importing into module.
  */
-void ThinLTOCodeGenerator::emitImports(StringRef ModulePath,
-                                       StringRef OutputName,
+void ThinLTOCodeGenerator::emitImports(Module &TheModule, StringRef OutputName,
                                        ModuleSummaryIndex &Index) {
   auto ModuleCount = Index.modulePaths().size();
+  auto ModuleIdentifier = TheModule.getModuleIdentifier();
 
   // Collect for each module the list of function it defines (GUID -> Summary).
   StringMap<GVSummaryMapTy> ModuleToDefinedGVSummaries(ModuleCount);
   Index.collectDefinedGVSummariesPerModule(ModuleToDefinedGVSummaries);
 
+  // Convert the preserved symbols set from string to GUID
+  auto GUIDPreservedSymbols = computeGUIDPreservedSymbols(
+      PreservedSymbols, Triple(TheModule.getTargetTriple()));
+
+  // Compute "dead" symbols, we don't want to import/export these!
+  computeDeadSymbolsInIndex(Index, GUIDPreservedSymbols);
+
   // Generate import/export list
   StringMap<FunctionImporter::ImportMapTy> ImportLists(ModuleCount);
   StringMap<FunctionImporter::ExportSetTy> ExportLists(ModuleCount);
@@ -699,13 +714,13 @@ void ThinLTOCodeGenerator::emitImports(StringRef ModulePath,
                            ExportLists);
 
   std::map<std::string, GVSummaryMapTy> ModuleToSummariesForIndex;
-  llvm::gatherImportedSummariesForModule(ModulePath, ModuleToDefinedGVSummaries,
-                                         ImportLists[ModulePath],
-                                         ModuleToSummariesForIndex);
+  llvm::gatherImportedSummariesForModule(
+      ModuleIdentifier, ModuleToDefinedGVSummaries,
+      ImportLists[ModuleIdentifier], ModuleToSummariesForIndex);
 
   std::error_code EC;
-  if ((EC =
-           EmitImportsFiles(ModulePath, OutputName, ModuleToSummariesForIndex)))
+  if ((EC = EmitImportsFiles(ModuleIdentifier, OutputName,
+                             ModuleToSummariesForIndex)))
     report_fatal_error(Twine("Failed to open ") + OutputName +
                        " to save imports lists\n");
 }
diff --git a/llvm/lib/Transforms/IPO/FunctionImport.cpp b/llvm/lib/Transforms/IPO/FunctionImport.cpp
index d8807f8a064..c5490f13d9a 100644
--- a/llvm/lib/Transforms/IPO/FunctionImport.cpp
+++ b/llvm/lib/Transforms/IPO/FunctionImport.cpp
@@ -293,9 +293,21 @@ static void computeImportForReferencedGlobals(
 
     LLVM_DEBUG(dbgs() << " ref -> " << VI << "\n");
 
+    // If this is a local variable, make sure we import the copy
+    // in the caller's module. The only time a local variable can
+    // share an entry in the index is if there is a local with the same name
+    // in another module that had the same source file name (in a different
+    // directory), where each was compiled in their own directory so there
+    // was not distinguishing path.
+    auto LocalNotInModule = [&](const GlobalValueSummary *RefSummary) -> bool {
+      return GlobalValue::isLocalLinkage(RefSummary->linkage()) &&
+             RefSummary->modulePath() != Summary.modulePath();
+    };
+
     for (auto &RefSummary : VI.getSummaryList())
       if (isa<GlobalVarSummary>(RefSummary.get()) &&
-          canImportGlobalVar(RefSummary.get())) {
+          canImportGlobalVar(RefSummary.get()) &&
+          !LocalNotInModule(RefSummary.get())) {
         auto ILI = ImportList[RefSummary->modulePath()].insert(VI.getGUID());
         // Only update stat if we haven't already imported this variable.
         if (ILI.second)