Expand DisallowedOriginKind with an explicit entry for internal bridging headers

include/swift/AST/DiagnosticsSema.def

@@ -3834,6 +3834,7 @@ ERROR(decl_from_hidden_module,none,
       "%2 was imported for SPI only|"
       "%2 was not imported by this file|"
       "C++ types from imported module %2 do not support library evolution|"
+      "it was imported via the internal bridging header|"
       "%2 was not imported publicly}3",
       (const Decl *, unsigned, Identifier, unsigned))
 ERROR(typealias_desugars_to_type_from_hidden_module,none,
@@ -3850,6 +3851,7 @@ ERROR(typealias_desugars_to_type_from_hidden_module,none,
       "%4 was imported for SPI only|"
       "%4 was not imported by this file|"
       "C++ types from imported module %4 do not support library evolution|"
+      "it was imported via the internal bridging header|"
       "%4 was not imported publicly}5",
       (const TypeAliasDecl *, StringRef, StringRef, unsigned, Identifier, unsigned))
 ERROR(conformance_from_implementation_only_module,none,
@@ -3864,6 +3866,7 @@ ERROR(conformance_from_implementation_only_module,none,
       "%3 was imported for SPI only|"
       "%3 was not imported by this file|"
       "C++ types from imported module %3 do not support library evolution|"
+      "it was imported via the internal bridging header|"
       "%3 was not imported publicly}4",
       (Type, Identifier, unsigned, Identifier, unsigned))
 NOTE(assoc_conformance_from_implementation_only_module,none,
@@ -7317,6 +7320,7 @@ ERROR(inlinable_decl_ref_from_hidden_module,
       "%2 was imported for SPI only|"
       "%2 was not imported by this file|"
       "C++ APIs from imported module %2 do not support library evolution|"
+      "it was imported via the internal bridging header|"
       "%2 was not imported publicly}3",
       (const ValueDecl *, unsigned, Identifier, unsigned))
 
@@ -7328,6 +7332,7 @@ ERROR(inlinable_typealias_desugars_to_type_from_hidden_module,
       "%4 was imported for SPI only|"
       "%4 was not imported by this file|"
       "C++ types from imported module %4 do not support library evolution|"
+      "it was imported via the internal bridging header|"
       "%4 was not imported publicly}5",
       (const TypeAliasDecl *, StringRef, StringRef, unsigned, Identifier, unsigned))
 

lib/Sema/ResilienceDiagnostics.cpp

@@ -277,7 +277,8 @@ static bool diagnoseValueDeclRefExportability(SourceLoc loc, const ValueDecl *D,
       D, DC, AccessLevel::Public,
       [&](AttributedImport<ImportedModule> attributedImport) {
         if (where.isExported() && reason != ExportabilityReason::General &&
-            originKind != DisallowedOriginKind::NonPublicImport) {
+            originKind != DisallowedOriginKind::NonPublicImport &&
+            originKind != DisallowedOriginKind::InternalBridgingHeaderImport) {
           // These may be reported twice, for the Type and for the TypeRepr.
           ModuleDecl *importedVia = attributedImport.module.importedModule,
                      *sourceModule = D->getModuleContext();
@@ -294,6 +295,7 @@ static bool diagnoseValueDeclRefExportability(SourceLoc loc, const ValueDecl *D,
     return false;
 
   case DisallowedOriginKind::NonPublicImport:
+  case DisallowedOriginKind::InternalBridgingHeaderImport:
     // With a few exceptions, access levels from imports are diagnosed during
     // access checking and should be skipped here.
     if (!shouldDiagnoseDeclAccess(D, where))

lib/Sema/TypeCheckAccess.cpp

@@ -2167,8 +2167,11 @@ swift::getDisallowedOriginKind(const Decl *decl,
   // See \c diagnoseValueDeclRefExportability.
   auto importSource = decl->getImportAccessFrom(where.getDeclContext());
   if (importSource.has_value() &&
-      importSource->accessLevel < AccessLevel::Public)
-    return DisallowedOriginKind::NonPublicImport;
+      importSource->accessLevel < AccessLevel::Public) {
+    return importSource->module.importedModule->isClangHeaderImportModule()
+      ? DisallowedOriginKind::InternalBridgingHeaderImport
+      : DisallowedOriginKind::NonPublicImport;
+  }
 
   return DisallowedOriginKind::None;
 }

lib/Sema/TypeCheckAccess.h

@@ -47,6 +47,10 @@ enum class DisallowedOriginKind : uint8_t {
   SPIOnly,
   MissingImport,
   FragileCxxAPI,
+
+  /// An import that is internal via the internally-imported bridging header.
+  InternalBridgingHeaderImport,
+
   NonPublicImport,
   None
 };

test/ClangImporter/Inputs/c-bridging-header.h

@@ -8,4 +8,5 @@ typedef struct {
   double x, y;
 } MyPoint;
 
+typedef double MyDouble;
 #endif

test/ClangImporter/InternalBridgingHeader/access_checking.swift

@@ -20,3 +20,20 @@ public func getX(point: MyPoint) -> Double { point.x } // expected-error{{functi
 
 // Comes from the macros module.
 public func returnsFromMacrosModule() -> okay_t { 0 }
+
+public protocol P {
+  associatedtype A
+}
+
+public struct MyType: P {
+  public typealias A = MyDouble
+  // expected-error@-1{{type alias cannot be declared public because its underlying type uses an internal type}}
+  // expected-note@-2{{type alias 'MyDouble' is imported by this file as 'internal' from bridging header}}
+}
+
+// expected-error@+1{{cannot use struct 'MyPoint' in an extension with public or '@usableFromInline' members; it was imported via the internal bridging header}}
+extension MyPoint: P {
+  public typealias A = MyDouble
+  // expected-error@-1{{type alias cannot be declared public because its underlying type uses an internal type}}
+  // expected-note@-2{{type alias 'MyDouble' is imported by this file as 'internal' from bridging header}}
+}