1 files changed, 30 insertions, 15 deletions

diff --git a/clang/lib/Serialization/ASTReaderDecl.cpp b/clang/lib/Serialization/ASTReaderDecl.cpp
index 4ff81d8d92b..ed684537a66 100644
--- a/clang/lib/Serialization/ASTReaderDecl.cpp
+++ b/clang/lib/Serialization/ASTReaderDecl.cpp
@@ -458,24 +458,28 @@ void ASTDeclReader::VisitDecl(Decl *D) {
   D->FromASTFile = true;
   D->setModulePrivate(Record[Idx++]);
   D->Hidden = D->isModulePrivate();
-  
+
   // Determine whether this declaration is part of a (sub)module. If so, it
   // may not yet be visible.
   if (unsigned SubmoduleID = readSubmoduleID(Record, Idx)) {
     // Store the owning submodule ID in the declaration.
     D->setOwningModuleID(SubmoduleID);
-    
-    // Module-private declarations are never visible, so there is no work to do.
-    if (!D->isModulePrivate()) {
-      if (Module *Owner = Reader.getSubmodule(SubmoduleID)) {
-        if (Owner->NameVisibility != Module::AllVisible) {
-          // The owning module is not visible. Mark this declaration as hidden.
-          D->Hidden = true;
-          
-          // Note that this declaration was hidden because its owning module is 
-          // not yet visible.
-          Reader.HiddenNamesMap[Owner].push_back(D);
-        }
+
+    if (D->Hidden) {
+      // Module-private declarations are never visible, so there is no work to do.
+    } else if (Reader.getContext().getLangOpts().ModulesLocalVisibility) {
+      // If local visibility is being tracked, this declaration will become
+      // hidden and visible as the owning module does. Inform Sema that this
+      // declaration might not be visible.
+      D->Hidden = true;
+    } else if (Module *Owner = Reader.getSubmodule(SubmoduleID)) {
+      if (Owner->NameVisibility != Module::AllVisible) {
+        // The owning module is not visible. Mark this declaration as hidden.
+        D->Hidden = true;
+        
+        // Note that this declaration was hidden because its owning module is 
+        // not yet visible.
+        Reader.HiddenNamesMap[Owner].push_back(D);
       }
     }
   }
@@ -1399,7 +1403,12 @@ void ASTDeclReader::MergeDefinitionData(
       // If MergeDD is visible or becomes visible, make the definition visible.
       if (!MergeDD.Definition->isHidden())
         DD.Definition->Hidden = false;
-      else {
+      else if (Reader.getContext().getLangOpts().ModulesLocalVisibility) {
+        Reader.getContext().mergeDefinitionIntoModule(
+            DD.Definition, MergeDD.Definition->getImportedOwningModule(),
+            /*NotifyListeners*/ false);
+        Reader.PendingMergedDefinitionsToDeduplicate.insert(DD.Definition);
+      } else {
         auto SubmoduleID = MergeDD.Definition->getOwningModuleID();
         assert(SubmoduleID && "hidden definition in no module");
         Reader.HiddenNamesMap[Reader.getSubmodule(SubmoduleID)].push_back(
@@ -3813,7 +3822,13 @@ void ASTDeclReader::UpdateDecl(Decl *D, ModuleFile &ModuleFile,
     case UPD_DECL_EXPORTED:
       unsigned SubmoduleID = readSubmoduleID(Record, Idx);
       Module *Owner = SubmoduleID ? Reader.getSubmodule(SubmoduleID) : nullptr;
-      if (Owner && Owner->NameVisibility != Module::AllVisible) {
+      if (Reader.getContext().getLangOpts().ModulesLocalVisibility) {
+        // FIXME: This doesn't send the right notifications if there are
+        // ASTMutationListeners other than an ASTWriter.
+        Reader.getContext().mergeDefinitionIntoModule(cast<NamedDecl>(D), Owner,
+                                                      /*NotifyListeners*/false);
+        Reader.PendingMergedDefinitionsToDeduplicate.insert(cast<NamedDecl>(D));
+      } else if (Owner && Owner->NameVisibility != Module::AllVisible) {
         // If Owner is made visible at some later point, make this declaration
         // visible too.
         Reader.HiddenNamesMap[Owner].push_back(D);