merge main into amd-staging

Author: z1.cciauto

clang/include/clang/Basic/DiagnosticSemaKinds.td

@@ -12391,6 +12391,13 @@ def err_invalid_module_name : Error<"%0 is an invalid name for a module">;
 def err_extern_def_in_header_unit : Error<
   "non-inline external definitions are not permitted in C++ header units">;
 
+def warn_exposure : Warning <
+  "TU local entity %0 is exposed">,
+  InGroup<DiagGroup<"TU-local-entity-exposure">>;
+def warn_reference_tu_local_entity_in_other_tu : Warning <
+  "instantiation of %0 triggers reference to TU-local entity %1 from other TU '%2'">,
+  InGroup<DiagGroup<"reference-tu-local-entity-in-other-tu">>;
+
 def warn_experimental_header_unit : Warning<
   "the implementation of header units is in an experimental phase">,
   InGroup<DiagGroup<"experimental-header-units">>;

clang/include/clang/Sema/Sema.h

@@ -9945,6 +9945,20 @@ class Sema final : public SemaBase {
 
   VisibleModuleSet VisibleModules;
 
+  /// Whether we had imported any named modules.
+  bool HadImportedNamedModules = false;
+  /// The set of instantiations we need to check if they references TU-local
+  /// entity from TUs. This only makes sense if we imported any named modules.
+  llvm::SmallVector<std::pair<FunctionDecl *, SourceLocation>>
+      PendingCheckReferenceForTULocal;
+  /// Implement [basic.link]p18, which requires that we can't use TU-local
+  /// entities from other TUs (ignoring header units).
+  void checkReferenceToTULocalFromOtherTU(FunctionDecl *FD,
+                                          SourceLocation PointOfInstantiation);
+  /// Implement [basic.link]p17, which diagnose for non TU local exposure in
+  /// module interface or module partition.
+  void checkExposure(const TranslationUnitDecl *TU);
+
   ///@}
 
   //

clang/lib/Sema/Sema.cpp

@@ -1621,6 +1621,8 @@ void Sema::ActOnEndOfTranslationUnit() {
 
   if (!PP.isIncrementalProcessingEnabled())
     TUScope = nullptr;
+
+  checkExposure(Context.getTranslationUnitDecl());
 }