1 files changed, 33 insertions, 10 deletions
diff --git a/clang/lib/Sema/SemaModule.cpp b/clang/lib/Sema/SemaModule.cpp
index af95b1a93cc4..a4b9f3c242c1 100644
--- a/clang/lib/Sema/SemaModule.cpp
+++ b/clang/lib/Sema/SemaModule.cpp
@@ -68,15 +68,8 @@ Sema::ActOnGlobalModuleFragmentDecl(SourceLocation ModuleLoc) {
 
   // We start in the global module; all those declarations are implicitly
   // module-private (though they do not have module linkage).
-  auto &Map = PP.getHeaderSearchInfo().getModuleMap();
-  auto *GlobalModule = Map.createGlobalModuleFragmentForModuleUnit(ModuleLoc);
-  assert(GlobalModule && "module creation should not fail");
-
-  // Enter the scope of the global module.
-  ModuleScopes.push_back({});
-  ModuleScopes.back().BeginLoc = ModuleLoc;
-  ModuleScopes.back().Module = GlobalModule;
-  VisibleModules.setVisible(GlobalModule, ModuleLoc);
+  Module *GlobalModule =
+      PushGlobalModuleFragment(ModuleLoc, /*IsImplicit=*/false);
 
   // All declarations created from now on are owned by the global module.
   auto *TU = Context.getTranslationUnitDecl();
@@ -390,11 +383,18 @@ DeclResult Sema::ActOnModuleImport(SourceLocation StartLoc,
   if (!ModuleScopes.empty())
     Context.addModuleInitializer(ModuleScopes.back().Module, Import);
 
-  // Re-export the module if needed.
   if (!ModuleScopes.empty() && ModuleScopes.back().ModuleInterface) {
+    // Re-export the module if the imported module is exported.
+    // Note that we don't need to add re-exported module to Imports field
+    // since `Exports` implies the module is imported already.
     if (ExportLoc.isValid() || getEnclosingExportDecl(Import))
       getCurrentModule()->Exports.emplace_back(Mod, false);
+    else
+      getCurrentModule()->Imports.insert(Mod);
   } else if (ExportLoc.isValid()) {
+    // [module.interface]p1:
+    // An export-declaration shall inhabit a namespace scope and appear in the
+    // purview of a module interface unit.
     Diag(ExportLoc, diag::err_export_not_in_module_interface);
   }
 
@@ -708,3 +708,26 @@ Decl *Sema::ActOnFinishExportDecl(Scope *S, Decl *D, SourceLocation RBraceLoc) {
 
   return D;
 }
+
+Module *Sema::PushGlobalModuleFragment(SourceLocation BeginLoc,
+                                       bool IsImplicit) {
+  ModuleMap &Map = PP.getHeaderSearchInfo().getModuleMap();
+  Module *GlobalModule =
+      Map.createGlobalModuleFragmentForModuleUnit(BeginLoc, getCurrentModule());
+  assert(GlobalModule && "module creation should not fail");
+
+  // Enter the scope of the global module.
+  ModuleScopes.push_back({BeginLoc, GlobalModule,
+                          /*ModuleInterface=*/false,
+                          /*ImplicitGlobalModuleFragment=*/IsImplicit,
+                          /*VisibleModuleSet*/{}});
+  VisibleModules.setVisible(GlobalModule, BeginLoc);
+
+  return GlobalModule;
+}
+
+void Sema::PopGlobalModuleFragment() {
+  assert(!ModuleScopes.empty() && getCurrentModule()->isGlobalModule() &&
+         "left the wrong module scope, which is not global module fragment");
+  ModuleScopes.pop_back();
+}