Improve some diagnostic with @_implementationOnly violations from internal bridging headers

Author: DougGregor

include/swift/AST/DiagnosticsSema.def

@@ -2702,8 +2702,8 @@ NOTE(module_imported_here,none,
 NOTE(decl_import_via_here,none,
      "%kind0 imported as "
      "'%select{private|fileprivate|internal|package|%ERROR|%ERROR}1' "
-     "from %2 here",
-     (const Decl *, AccessLevel, const ModuleDecl*))
+     "from %select{%2 here|bridging header}3",
+     (const Decl *, AccessLevel, const ModuleDecl*, bool))
 NOTE(decl_import_via_local,none,
      "%kind0 is imported by this file as "
      "'%select{private|fileprivate|internal|package|%ERROR|%ERROR}1' "

lib/Sema/ResilienceDiagnostics.cpp

@@ -133,7 +133,9 @@ bool TypeChecker::diagnoseInlinableDeclRefAccess(SourceLoc loc,
     Context.Diags.diagnose(problematicImport->importLoc,
                            diag::decl_import_via_here, D,
                            problematicImport->accessLevel,
-                           problematicImport->module.importedModule);
+                           problematicImport->module.importedModule,
+                           problematicImport->module.importedModule
+                             ->isClangHeaderImportModule());
   }
 
   return (downgradeToWarning == DowngradeToWarning::No);
@@ -213,7 +215,9 @@ static bool diagnoseTypeAliasDeclRefExportability(SourceLoc loc,
     ctx.Diags.diagnose(limitImport->importLoc,
                        diag::decl_import_via_here, D,
                        limitImport->accessLevel,
-                       limitImport->module.importedModule);
+                       limitImport->module.importedModule,
+                       limitImport->module.importedModule
+                         ->isClangHeaderImportModule());
   }
 
   return true;
@@ -368,7 +372,9 @@ static bool diagnoseValueDeclRefExportability(SourceLoc loc, const ValueDecl *D,
     ctx.Diags.diagnose(import->importLoc,
                        diag::decl_import_via_here, D,
                        import->accessLevel,
-                       import->module.importedModule);
+                       import->module.importedModule,
+                       import->module.importedModule
+                         ->isClangHeaderImportModule());
   }
 
   return true;
@@ -454,7 +460,9 @@ TypeChecker::diagnoseConformanceExportability(SourceLoc loc,
     ctx.Diags.diagnose(limitImport->importLoc,
                        diag::decl_import_via_here, ext,
                        limitImport->accessLevel,
-                       limitImport->module.importedModule);
+                       limitImport->module.importedModule,
+                       limitImport->module.importedModule
+                         ->isClangHeaderImportModule());
   }
 
   return true;

lib/Sema/TypeCheckAccess.cpp

@@ -461,7 +461,9 @@ static void noteLimitingImport(const Decl *userDecl, ASTContext &ctx,
     if (limitImport->importLoc.isValid())
       ctx.Diags.diagnose(limitImport->importLoc, diag::decl_import_via_here,
                          complainDecl, limitImport->accessLevel,
-                         limitImport->module.importedModule);
+                         limitImport->module.importedModule,
+                         limitImport->module.importedModule
+                           ->isClangHeaderImportModule());
   } else if (limitImport->importLoc.isValid()) {
     ctx.Diags.diagnose(limitImport->importLoc, diag::module_imported_here,
                        limitImport->module.importedModule,

test/ClangImporter/InternalBridgingHeader/implementation_only_checking.swift

@@ -0,0 +1,21 @@
+// RUN: %empty-directory(%t)
+// RUN: mkdir -p %t/tmp
+
+// Test with the normal bridging header.
+// RUN: %target-typecheck-verify-swift -internal-import-bridging-header %S/../Inputs/c-bridging-header.h -sdk %clang-importer-sdk -verify-ignore-unknown
+
+// RUN: not %target-swift-frontend -typecheck -internal-import-bridging-header %S/../Inputs/c-bridging-header.h -sdk %clang-importer-sdk %s 2>&1 | %FileCheck %s
+
+// Test with a precompiled bridging header.
+// RUN: %target-swift-frontend -emit-pch -o %t/c-bridging-header.pch %S/../Inputs/c-bridging-header.h -sdk %clang-importer-sdk
+// RUN: %target-typecheck-verify-swift -internal-import-bridging-header %t/c-bridging-header.pch -sdk %clang-importer-sdk -verify-ignore-unknown
+
+
+@inlinable
+public func f() -> Any {
+  return red
+  // expected-error@-1{{var 'red' is internal and cannot be referenced from an '@inlinable' function}}
+  // expected-warning@-2{{getter for var 'red' is internal and should not be referenced from an '@inlinable' function}}
+}
+
+// CHECK: var 'red' imported as 'internal' from bridging header