[Modules TS] Diagnose attempts to enter module implementation units without the module interface being available.

llvm-svn: 315381

1 files changed, 7 insertions, 5 deletions

diff --git a/clang/lib/Sema/SemaDecl.cpp b/clang/lib/Sema/SemaDecl.cpp
index a74cb57eab6..84cae84dec7 100644
--- a/clang/lib/Sema/SemaDecl.cpp
+++ b/clang/lib/Sema/SemaDecl.cpp
@@ -16168,6 +16168,7 @@ Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc,
     // implementation unit. That indicates the 'export' is missing.
     Diag(ModuleLoc, diag::err_module_interface_implementation_mismatch)
       << FixItHint::CreateInsertion(ModuleLoc, "export ");
+    MDK = ModuleDeclKind::Interface;
     break;
 
   case LangOptions::CMK_ModuleMap:
@@ -16207,7 +16208,7 @@ Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc,
   assert(ModuleScopes.size() == 1 && "expected to be at global module scope");
 
   switch (MDK) {
-  case ModuleDeclKind::Module: {
+  case ModuleDeclKind::Interface: {
     // We can't have parsed or imported a definition of this module or parsed a
     // module map defining it already.
     if (auto *M = Map.findModule(ModuleName)) {
@@ -16237,14 +16238,16 @@ Sema::DeclGroupPtrTy Sema::ActOnModuleDecl(SourceLocation StartLoc,
         PP.getIdentifierInfo(ModuleName), Path[0].second);
     Mod = getModuleLoader().loadModule(ModuleLoc, Path, Module::AllVisible,
                                        /*IsIncludeDirective=*/false);
-    // FIXME: Produce an error in this case.
-    if (!Mod)
+    if (!Mod) {
+      Diag(ModuleLoc, diag::err_module_not_defined) << ModuleName;
       return nullptr;
+    }
     break;
   }
 
   // Switch from the global module to the named module.
   ModuleScopes.back().Module = Mod;
+  ModuleScopes.back().ModuleInterface = MDK != ModuleDeclKind::Implementation;
   VisibleModules.setVisible(Mod, ModuleLoc);
 
   // From now on, we have an owning module for all declarations we see.
@@ -16430,8 +16433,7 @@ Decl *Sema::ActOnStartExportDecl(Scope *S, SourceLocation ExportLoc,
   // C++ Modules TS draft:
   //   An export-declaration shall appear in the purview of a module other than
   //   the global module.
-  if (ModuleScopes.empty() ||
-      ModuleScopes.back().Module->Kind != Module::ModuleInterfaceUnit)
+  if (ModuleScopes.empty() || !ModuleScopes.back().ModuleInterface)
     Diag(ExportLoc, diag::err_export_not_in_module_interface);
 
   //   An export-declaration [...] shall not contain more than one