Hide objcImpl resilience support behind feature

Resilence support will require changes to the Objective-C runtime to expand support for metadata initialization functions. Add a separate experimental feature flag to help with staging that support in, and modify diagnostics to not suggest increasing the minimum deployment target for now.

Author: beccadax

include/swift/AST/DiagnosticsIRGen.def

@@ -69,7 +69,12 @@ NOTE(layout_strings_blocked,none,
      "Layout string value witnesses have been disabled for module '%0' "
      "through block list entry", (StringRef))
 
-ERROR(attr_objc_implementation_resilient_property_unsupported, none,
+ERROR(attr_objc_implementation_resilient_property_not_supported, none,
+      "'@implementation' does not support stored properties whose size can "
+      "change due to library evolution; store this value in an object or 'any' "
+      "type",
+      ())
+ERROR(attr_objc_implementation_resilient_property_deployment_target, none,
       "'@implementation' on %0 %1 does not support stored properties whose "
       "size can change due to library evolution; raise the minimum deployment "
       "target to %0 %2 or store this value in an object or 'any' type",

include/swift/Basic/Features.def

@@ -379,6 +379,11 @@ EXPERIMENTAL_FEATURE(GlobalActorIsolatedTypesUsability, true)
 // Enable @implementation on extensions of ObjC classes.
 EXPERIMENTAL_FEATURE(ObjCImplementation, true)
 
+// Enable @implementation on extensions of ObjC classes with non-fixed layout
+// due to resilient stored properties. Requires OS support; this flag exists for
+// staging purposes.
+EXPERIMENTAL_FEATURE(ObjCImplementationWithResilientStorage, true)
+
 // Enable @implementation on @_cdecl functions.
 EXPERIMENTAL_FEATURE(CImplementation, true)
 

lib/AST/FeatureSet.cpp

@@ -694,6 +694,7 @@ static bool usesFeatureGlobalActorIsolatedTypesUsability(Decl *decl) {
 }
 
 UNINTERESTING_FEATURE(ObjCImplementation)
+UNINTERESTING_FEATURE(ObjCImplementationWithResilientStorage)
 UNINTERESTING_FEATURE(CImplementation)
 
 static bool usesFeatureSensitive(Decl *decl) {

lib/IRGen/GenMeta.cpp

@@ -5096,12 +5096,19 @@ diagnoseUnsupportedObjCImplLayout(IRGenModule &IGM, ClassDecl *classDecl,
             elemLayout.getType().isFixedSize())
         return;
 
-      diags.diagnose(
-          field.getVarDecl(),
-          diag::attr_objc_implementation_resilient_property_unsupported,
-          prettyPlatformString(targetPlatform(ctx.LangOpts)),
-          currentAvailability.getOSVersion().getLowerEndpoint(),
-          requiredAvailability.getOSVersion().getLowerEndpoint());
+      if (ctx.LangOpts.hasFeature(
+                    Feature::ObjCImplementationWithResilientStorage))
+        diags.diagnose(
+            field.getVarDecl(),
+            diag::attr_objc_implementation_resilient_property_deployment_target,
+            prettyPlatformString(targetPlatform(ctx.LangOpts)),
+            currentAvailability.getOSVersion().getLowerEndpoint(),
+            requiredAvailability.getOSVersion().getLowerEndpoint());
+      else
+        diags.diagnose(
+            field.getVarDecl(),
+            diag::attr_objc_implementation_resilient_property_not_supported);
+
       diagnosed = true;
     });
 

test/IRGen/objc_implementation_deployment_target_resilience.swift

@@ -1,13 +1,14 @@
 // RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -target %target-stable-abi-triple -I %S/Inputs/abi -F %clang-importer-sdk-path/frameworks %s -import-objc-header %S/Inputs/objc_implementation.h -emit-ir -o %t.ir -enable-library-evolution -verify
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -target %target-stable-abi-triple -I %S/Inputs/abi -F %clang-importer-sdk-path/frameworks %s -import-objc-header %S/Inputs/objc_implementation.h -emit-ir -o %t.ir -enable-library-evolution -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple
 // REQUIRES: objc_interop
 
 @_objcImplementation extension ImplClassWithResilientStoredProperty {
   @objc var beforeInt: Int32 = 0    // no-error
-  final var a: Mirror?              // expected-error {{does not support stored properties whose size can change due to library evolution; raise the minimum deployment target to}}
+  final var a: Mirror?              // expected-error {{does not support stored properties whose size can change due to library evolution; store this value in an object or 'any' type}}
   final var b: AnyKeyPath?          // no-error
   final var c: Int = 0              // no-error
   final var d: S1?                  // no-error
-  final var e: S2?                  // expected-error {{does not support stored properties whose size can change due to library evolution; raise the minimum deployment target to}}
+  final var e: S2?                  // expected-error {{does not support stored properties whose size can change due to library evolution; store this value in an object or 'any' type}}
   final var f: C1?                  // no-error
   @objc var afterInt: Int32 = 0     // no-error
 }

test/Interpreter/objc_implementation.swift

@@ -50,10 +50,12 @@ class LastWords {
   }
 
   @objc func testSelf() {
+#if RESILIENCE
     let resilientImpl = Self.makeResilientImpl()
     resilientImpl.printSelf(withLabel: 1)
     resilientImpl.mutate()
     resilientImpl.printSelf(withLabel: 2)
+#endif
 
     self.printSelf(withLabel: 1)
     self.implProperty = 42
@@ -72,7 +74,11 @@ class LastWords {
   @objc func someMethod() -> String { "ImplClass" }
 
   @objc class func makeResilientImpl() -> ImplClassWithResilientStoredProperty {
+#if RESILIENCE
     ImplClassWithResilientStoredProperty()
+#else
+    fatalError()
+#endif
   }
 
   open override var description: String {
@@ -102,11 +108,14 @@ class SwiftSubclass: ImplClass {
     print("\(type).otherProperty =", self.otherProperty)
   }
 
+#if RESILIENCE
   override class func makeResilientImpl() -> ImplClassWithResilientStoredProperty {
     SwiftResilientStoredSubclass()
   }
+#endif
 }
 
+#if RESILIENCE
 @_objcImplementation extension ImplClassWithResilientStoredProperty {
   final var mirror: Mirror?
   final var afterMirrorProperty: Int
@@ -151,6 +160,7 @@ extension SwiftSubclass {
     }
   }
 }
+#endif
 
 @_objcImplementation @_cdecl("implFunc") public func implFunc(_ param: Int32) {
   print("implFunc(\(param))")
@@ -162,12 +172,12 @@ ImplClass.runTests()
 // CHECK: implFunc(1989)
 // CHECK-LABEL: *** ImplClass init ***
 // CHECK: ImplClass.init()
-// CHECK-LABEL: *** ImplClassWithResilientStoredProperty #1 ***
-// CHECK: ImplClassWithResilientStoredProperty.mirror = nil
-// CHECK: ImplClassWithResilientStoredProperty.afterMirrorProperty = 0
-// CHECK-LABEL: *** ImplClassWithResilientStoredProperty #2 ***
-// CHECK: ImplClassWithResilientStoredProperty.mirror = nil
-// CHECK: ImplClassWithResilientStoredProperty.afterMirrorProperty = 42
+// CHECK-RESILIENCE-LABEL: *** ImplClassWithResilientStoredProperty #1 ***
+// CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.mirror = nil
+// CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.afterMirrorProperty = 0
+// CHECK-RESILIENCE-LABEL: *** ImplClassWithResilientStoredProperty #2 ***
+// CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.mirror = nil
+// CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.afterMirrorProperty = 42
 // CHECK-LABEL: *** ImplClass #1 ***
 // CHECK: ImplClass.someMethod() = ImplClass
 // CHECK: ImplClass.implProperty = 0
@@ -183,16 +193,16 @@ ImplClass.runTests()
 // CHECK-LABEL: *** SwiftSubclass init ***
 // CHECK: SwiftSubclass.init()
 // CHECK: ImplClass.init()
-// CHECK-LABEL: *** SwiftResilientStoredSubclass #1 ***
-// CHECK: SwiftResilientStoredSubclass.mirror = nil
-// CHECK: SwiftResilientStoredSubclass.afterMirrorProperty = 0
-// CHECK: SwiftResilientStoredSubclass.mirror2 = nil
-// CHECK: SwiftResilientStoredSubclass.afterMirrorProperty2 = 1
-// CHECK-LABEL: *** SwiftResilientStoredSubclass #2 ***
-// CHECK: SwiftResilientStoredSubclass.mirror = nil
-// CHECK: SwiftResilientStoredSubclass.afterMirrorProperty = 42
-// CHECK: SwiftResilientStoredSubclass.mirror2 = nil
-// CHECK: SwiftResilientStoredSubclass.afterMirrorProperty2 = 43
+// CHECK-RESILIENCE-LABEL: *** SwiftResilientStoredSubclass #1 ***
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror = nil
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty = 0
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror2 = nil
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty2 = 1
+// CHECK-RESILIENCE-LABEL: *** SwiftResilientStoredSubclass #2 ***
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror = nil
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty = 42
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror2 = nil
+// CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty2 = 43
 // CHECK-LABEL: *** SwiftSubclass #1 ***
 // CHECK: SwiftSubclass.someMethod() = SwiftSubclass
 // CHECK: SwiftSubclass.implProperty = 0

test/Interpreter/objc_implementation_objc_client.m

@@ -77,12 +77,12 @@ int main() {
   // CHECK: implFunc(1989)
   // CHECK-LABEL: *** ImplClass init ***
   // CHECK: ImplClass.init()
-  // CHECK-LABEL: *** ImplClassWithResilientStoredProperty #1 ***
-  // CHECK: ImplClassWithResilientStoredProperty.mirror = nil
-  // CHECK: ImplClassWithResilientStoredProperty.afterMirrorProperty = 0
-  // CHECK-LABEL: *** ImplClassWithResilientStoredProperty #2 ***
-  // CHECK: ImplClassWithResilientStoredProperty.mirror = nil
-  // CHECK: ImplClassWithResilientStoredProperty.afterMirrorProperty = 42
+  // CHECK-RESILIENCE-LABEL: *** ImplClassWithResilientStoredProperty #1 ***
+  // CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.mirror = nil
+  // CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.afterMirrorProperty = 0
+  // CHECK-RESILIENCE-LABEL: *** ImplClassWithResilientStoredProperty #2 ***
+  // CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.mirror = nil
+  // CHECK-RESILIENCE: ImplClassWithResilientStoredProperty.afterMirrorProperty = 42
   // CHECK-LABEL: *** ImplClass #1 ***
   // CHECK: ImplClass.someMethod() = ImplClass
   // CHECK: ImplClass.implProperty = 0
@@ -98,16 +98,16 @@ int main() {
   // CHECK-LABEL: *** SwiftSubclass init ***
   // CHECK: SwiftSubclass.init()
   // CHECK: ImplClass.init()
-  // CHECK-LABEL: *** SwiftResilientStoredSubclass #1 ***
-  // CHECK: SwiftResilientStoredSubclass.mirror = nil
-  // CHECK: SwiftResilientStoredSubclass.afterMirrorProperty = 0
-  // CHECK: SwiftResilientStoredSubclass.mirror2 = nil
-  // CHECK: SwiftResilientStoredSubclass.afterMirrorProperty2 = 1
-  // CHECK-LABEL: *** SwiftResilientStoredSubclass #2 ***
-  // CHECK: SwiftResilientStoredSubclass.mirror = nil
-  // CHECK: SwiftResilientStoredSubclass.afterMirrorProperty = 42
-  // CHECK: SwiftResilientStoredSubclass.mirror2 = nil
-  // CHECK: SwiftResilientStoredSubclass.afterMirrorProperty2 = 43
+  // CHECK-RESILIENCE-LABEL: *** SwiftResilientStoredSubclass #1 ***
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror = nil
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty = 0
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror2 = nil
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty2 = 1
+  // CHECK-RESILIENCE-LABEL: *** SwiftResilientStoredSubclass #2 ***
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror = nil
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty = 42
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.mirror2 = nil
+  // CHECK-RESILIENCE: SwiftResilientStoredSubclass.afterMirrorProperty2 = 43
   // CHECK-LABEL: *** SwiftSubclass #1 ***
   // CHECK: SwiftSubclass.someMethod() = SwiftSubclass
   // CHECK: SwiftSubclass.implProperty = 0
@@ -138,14 +138,14 @@ int main() {
   // CHECK-LABEL: *** ObjCClientSubclass init ***
   // CHECK: -[ObjCClientSubclass init]
   // CHECK: ImplClass.init()
-  // CHECK-LABEL: *** ObjCClientResilientSubclass #1 ***
-  // CHECK: ObjCClientResilientSubclass.mirror = nil
-  // CHECK: ObjCClientResilientSubclass.afterMirrorProperty = 0
-  // CHECK: ObjCClientResilientSubclass.subclassProperty = 100
-  // CHECK-LABEL: *** ObjCClientResilientSubclass #2 ***
-  // CHECK: ObjCClientResilientSubclass.mirror = nil
-  // CHECK: ObjCClientResilientSubclass.afterMirrorProperty = 42
-  // CHECK: ObjCClientResilientSubclass.subclassProperty = 101
+  // CHECK-RESILIENCE-LABEL: *** ObjCClientResilientSubclass #1 ***
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.mirror = nil
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.afterMirrorProperty = 0
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.subclassProperty = 100
+  // CHECK-RESILIENCE-LABEL: *** ObjCClientResilientSubclass #2 ***
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.mirror = nil
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.afterMirrorProperty = 42
+  // CHECK-RESILIENCE: ObjCClientResilientSubclass.subclassProperty = 101
   // CHECK-LABEL: *** ObjCClientSubclass #1 ***
   // CHECK: ObjCClientSubclass.someMethod() = ObjCClientSubclass
   // CHECK: ObjCClientSubclass.implProperty = 0
@@ -194,11 +194,13 @@ int main() {
   return 0;
 }
 
+#if RESILIENCE
 @interface ObjCClientResilientSubclass : ImplClassWithResilientStoredProperty
 
 @property (assign) NSInteger subclassProperty;
 
 @end
+#endif
 
 @implementation ObjCClientSubclass
 
@@ -225,12 +227,15 @@ - (NSString *)someMethod {
   return @"ObjCClientSubclass";
 }
 
+#if RESILIENCE
 + (ImplClassWithResilientStoredProperty *)makeResilientImpl {
   return [ObjCClientResilientSubclass new];
 }
+#endif
 
 @end
 
+#if RESILIENCE
 @implementation ObjCClientResilientSubclass
 
 - (id)init {
@@ -251,3 +256,4 @@ - (void)mutate {
 }
 
 @end
+#endif

test/Interpreter/objc_implementation_resilience.swift

@@ -0,0 +1,7 @@
+// Variant of Interpreter/objc_implementation.swift that tests resilient stored properties.
+// Will not execute correctly without ObjC runtime support.
+// REQUIRES: rdar109171643
+
+// RUN: %target-run-simple-swift(-import-objc-header %S/Inputs/objc_implementation.h -D TOP_LEVEL_CODE -D RESILIENCE -swift-version 5 -enable-experimental-feature CImplementation -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple) %S/objc_implementation.swift | %FileCheck %S/objc_implementation.swift --check-prefixes CHECK,CHECK-RESILIENCE
+// REQUIRES: executable_test
+// REQUIRES: objc_interop

test/Interpreter/objc_implementation_resilience_objc_client.m

@@ -0,0 +1,29 @@
+// Variant of Interpreter/objc_implementation_objc_client.m that tests resilient stored properties.
+// Will not execute correctly without ObjC runtime support.
+// REQUIRES: rdar109171643
+
+// REQUIRES-X: rdar101497120
+
+//
+// Build objc_implementation.framework
+//
+// RUN: %empty-directory(%t-frameworks)
+// RUN: %empty-directory(%t-frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule)
+// RUN: %empty-directory(%t-frameworks/objc_implementation.framework/Headers)
+// RUN: cp %S/Inputs/objc_implementation.modulemap %t-frameworks/objc_implementation.framework/Modules/module.modulemap
+// RUN: cp %S/Inputs/objc_implementation.h %t-frameworks/objc_implementation.framework/Headers
+// RUN: %target-build-swift-dylib(%t-frameworks/objc_implementation.framework/objc_implementation) -emit-module-path %t-frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule/%module-target-triple.swiftmodule -module-name objc_implementation -F %t-frameworks -import-underlying-module -Xlinker -install_name -Xlinker %t-frameworks/objc_implementation.framework/objc_implementation %S/objc_implementation.swift -D RESILIENCE -enable-experimental-feature CImplementation -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple
+//
+// Execute this file
+//
+// RUN: %empty-directory(%t)
+// RUN: %target-clang %S/objc_implementation_objc_client.m -isysroot %sdk -F %t-frameworks -lobjc -fmodules -fobjc-arc -o %t/objc_implementation_objc_client -D RESILIENCE
+// RUN: %target-codesign %t/objc_implementation_objc_client
+// RUN: %target-run %t/objc_implementation_objc_client 2>&1 | %FileCheck %S/objc_implementation_objc_client.m --check-prefixes CHECK,CHECK-RESILIENCE
+
+// REQUIRES: executable_test
+// REQUIRES: objc_interop
+
+// FIXME: This test fails in Swift CI simulators, but I have not been able to
+//        reproduce this locally.
+// REQUIRES: OS=macosx

test/Interpreter/objc_implementation_resilience_swift_client.swift

@@ -0,0 +1,39 @@
+// Variant of Interpreter/objc_implementation_swift_client.swift that tests resilient stored properties.
+// Will not execute correctly without ObjC runtime support.
+// REQUIRES: rdar109171643
+
+// Test doesn't pass on all platforms (rdar://101543397)
+// REQUIRES: OS=macosx
+// UNSUPPORTED: use_os_stdlib
+// UNSUPPORTED: back_deployment_runtime
+
+//
+// Build objc_implementation.framework
+//
+// RUN: %empty-directory(%t)
+// RUN: %empty-directory(%t/frameworks)
+// RUN: %empty-directory(%t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule)
+// RUN: %empty-directory(%t/frameworks/objc_implementation.framework/Headers)
+// RUN: cp %S/Inputs/objc_implementation.modulemap %t/frameworks/objc_implementation.framework/Modules/module.modulemap
+// RUN: cp %S/Inputs/objc_implementation.h %t/frameworks/objc_implementation.framework/Headers
+// RUN: %target-build-swift-dylib(%t/frameworks/objc_implementation.framework/objc_implementation) -D RESILIENCE -enable-experimental-feature CImplementation -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple -emit-module-path %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule/%module-target-triple.swiftmodule -module-name objc_implementation -F %t/frameworks -import-underlying-module -Xlinker -install_name -Xlinker %t/frameworks/objc_implementation.framework/objc_implementation %S/objc_implementation.swift
+
+//
+// Execute this file
+//
+// RUN: %empty-directory(%t/swiftmod)
+// RUN: %target-build-swift %S/objc_implementation_swift_client.swift -module-cache-path %t/swiftmod/mcp -F %t/frameworks -o %t/swiftmod/a.out -module-name main -D RESILIENCE -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple
+// RUN: %target-codesign %t/swiftmod/a.out
+// RUN: %target-run %t/swiftmod/a.out | %FileCheck %S/objc_implementation_swift_client.swift -check-prefixes CHECK,CHECK-RESILIENCE
+
+//
+// Execute again, without the swiftmodule this time
+//
+// RUN: mv %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule %t/frameworks/objc_implementation.framework/Modules/objc_implementation.swiftmodule.disabled
+// RUN: %empty-directory(%t/clangmod)
+// RUN: %target-build-swift %S/objc_implementation_swift_client.swift -module-cache-path %t/clangmod/mcp -F %t/frameworks -o %t/clangmod/a.out -module-name main -D RESILIENCE -enable-experimental-feature ObjCImplementationWithResilientStorage -target %target-future-triple
+// RUN: %target-codesign %t/clangmod/a.out
+// RUN: %target-run %t/clangmod/a.out | %FileCheck %S/objc_implementation_swift_client.swift --check-prefixes CHECK,CHECK-RESILIENCE
+
+// REQUIRES: executable_test
+// REQUIRES: objc_interop