Add @objc @implementation tests for custom availability domains.

These tests reveal that the `@objc @implementation` checker does not verify the
availability of implementations. It should reject implementations where the
extension or its members are more or less available than the class or method
that they implement.

Fixing this is tracked by rdar://156564928.

Author: tshortli

test/ClangImporter/Inputs/availability_domains_bridging_header.h

@@ -6,3 +6,65 @@ static struct __AvailabilityDomain bay_bridge
 static struct __AvailabilityDomain golden_gate_bridge
     __attribute__((availability_domain(GoldenGateBridge))) = {
         __AVAILABILITY_DOMAIN_DISABLED, 0};
+
+#define AVAIL 0
+#define UNAVAIL 1
+
+
+#if __OBJC__
+@import Foundation;
+
+__attribute__((availability(domain:BayBridge, AVAIL)))
+@interface BayBridgeAvailable : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:BayBridge, UNAVAIL)))
+@interface BayBridgeUnavailable : NSObject
+- (instancetype)init;
+@end
+
+@interface ImplementMe : NSObject
+- (instancetype)init;
+- (void)availableInBayBridge __attribute__((availability(domain:BayBridge, AVAIL)));
+- (void)unavailableInBayBridge __attribute__((availability(domain:BayBridge, UNAVAIL)));
+
+- (void)availableInGoldenGateBridge __attribute__((availability(domain:GoldenGateBridge, AVAIL)));
+- (void)unavailableInGoldenGateBridge __attribute__((availability(domain:GoldenGateBridge, UNAVAIL)));
+
+@end
+
+__attribute__((availability(domain:BayBridge, AVAIL)))
+@interface ImplementMeBayBridgeAvailable : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:BayBridge, UNAVAIL)))
+@interface ImplementMeBayBridgeUnavailable : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:GoldenGateBridge, AVAIL)))
+@interface ImplementMeGoldenGateBridgeAvailable : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:GoldenGateBridge, AVAIL)))
+@interface ImplementMeGoldenGateBridgeAvailable2 : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:GoldenGateBridge, AVAIL)))
+@interface ImplementMeGoldenGateBridgeAvailable3 : NSObject
+- (instancetype)init;
+@end
+
+__attribute__((availability(domain:GoldenGateBridge, UNAVAIL)))
+@interface ImplementMeGoldenGateBridgeUnavailable : NSObject
+- (instancetype)init;
+@end
+
+#endif // __OBJC__
+
+#undef UNAVAIL
+#undef AVAIL

test/ClangImporter/availability_custom_domains_objc.swift

@@ -0,0 +1,80 @@
+// RUN: %empty-directory(%t)
+
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -verify \
+// RUN:   -import-objc-header %S/Inputs/availability_domains_bridging_header.h \
+// RUN:   -I %S/../Inputs/custom-modules/availability-domains \
+// RUN:   -enable-experimental-feature CustomAvailability \
+// RUN:   %s %S/Inputs/availability_custom_domains_other.swift
+
+// Re-test with the bridging header precompiled into a .pch.
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -emit-pch \
+// RUN:   -o %t/bridging-header.pch %S/Inputs/availability_domains_bridging_header.h
+
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -verify \
+// RUN:   -import-objc-header %t/bridging-header.pch \
+// RUN:   -I %S/../Inputs/custom-modules/availability-domains \
+// RUN:   -enable-experimental-feature CustomAvailability \
+// RUN:   %s %S/Inputs/availability_custom_domains_other.swift
+
+// REQUIRES: swift_feature_CustomAvailability
+// REQUIRES: objc_interop
+
+import Oceans // re-exports Rivers
+
+func testObjCClasses( // expected-note {{add '@available' attribute to enclosing global function}}
+  _ bayBridgeAvailable: BayBridgeAvailable, // expected-error {{'BayBridgeAvailable' is only available in BayBridge}}
+  _ bayBridgeUnavailable: BayBridgeUnavailable, // expected-error {{'BayBridgeUnavailable' is unavailable}}
+) { }
+
+@objc @implementation
+extension ImplementMe {
+  // FIXME: [availability] @available(BayBridge) should be required
+  func availableInBayBridge() { }
+
+  // FIXME: [availability] Should match and suggest @available(BayBridge, unavailable)
+  func unavailableInBayBridge() { } // expected-error {{instance method 'unavailableInBayBridge()' does not match any instance method declared in the headers for 'ImplementMe'}}
+  // expected-note@-1 {{add 'private' or 'fileprivate'}}
+  // expected-note@-2 {{add 'final' to define a Swift-only instance method}}
+
+  @available(GoldenGateBridge)
+  func availableInGoldenGateBridge() { }
+
+  // FIXME: [availability] This should be accepted
+  @available(GoldenGateBridge, unavailable)
+  func unavailableInGoldenGateBridge() { } // expected-error {{instance method 'unavailableInGoldenGateBridge()' does not match any instance method declared in the headers for 'ImplementMe'}}
+  // expected-note@-1 {{add 'private' or 'fileprivate'}}
+  // expected-note@-2 {{add 'final' to define a Swift-only instance method}}
+}
+
+@objc @implementation
+extension ImplementMeBayBridgeAvailable { // expected-error {{'ImplementMeBayBridgeAvailable' is only available in BayBridge}}
+  // expected-note@-1 {{add '@available' attribute to enclosing extension}}
+}
+
+@objc @implementation
+extension ImplementMeBayBridgeUnavailable { // expected-error {{'ImplementMeBayBridgeUnavailable' is unavailable}}
+}
+
+@available(GoldenGateBridge)
+@objc @implementation
+extension ImplementMeGoldenGateBridgeAvailable {
+}
+
+@available(BayBridge)
+@objc @implementation
+extension ImplementMeGoldenGateBridgeAvailable2 { // expected-error {{'ImplementMeGoldenGateBridgeAvailable2' is only available in GoldenGateBridge}}
+  // expected-note@-1 {{add '@available' attribute to enclosing extension}}
+}
+
+// FIXME: [availability] This implementation should be rejected because its less
+// available than the original class declaration.
+@available(BayBridge)
+@available(GoldenGateBridge)
+@objc @implementation
+extension ImplementMeGoldenGateBridgeAvailable3 {
+}
+
+@available(GoldenGateBridge, unavailable)
+@objc @implementation
+extension ImplementMeGoldenGateBridgeUnavailable {
+}