Sema: Don't diagnose declarations more available than unavailable container

include/swift/AST/DiagnosticsSema.def

@@ -5990,10 +5990,6 @@ ERROR(availability_decl_more_than_enclosing, none,
       "%0 cannot be more available than enclosing scope",
       (DescriptiveDeclKind))
 
-WARNING(availability_decl_more_than_unavailable_enclosing, none,
-        "%0 cannot be more available than unavailable enclosing scope",
-        (DescriptiveDeclKind))
-
 NOTE(availability_implicit_decl_here, none,
      "%0 implicitly declared here with availability of %1 %2 or newer",
      (DescriptiveDeclKind, StringRef, llvm::VersionTuple))

lib/AST/Availability.cpp

@@ -109,15 +109,6 @@ static AvailableAttr *createAvailableAttr(PlatformKind Platform,
   llvm::VersionTuple Obsoleted =
       Inferred.Obsoleted.value_or(llvm::VersionTuple());
 
-  // If a decl is unavailable then it cannot have any introduced, deprecated, or
-  // obsoleted version.
-  if (Inferred.PlatformAgnostic ==
-      PlatformAgnosticAvailabilityKind::Unavailable) {
-    Introduced = llvm::VersionTuple();
-    Deprecated = llvm::VersionTuple();
-    Obsoleted = llvm::VersionTuple();
-  }
-
   return new (Context)
       AvailableAttr(SourceLoc(), SourceRange(), Platform,
                     Message, Rename, RenameDecl,
@@ -168,27 +159,6 @@ void AvailabilityInference::applyInferredAvailableAttrs(
 
   DeclAttributes &Attrs = ToDecl->getAttrs();
 
-  // Some kinds of platform agnostic availability supersede any platform
-  // specific availability.
-  auto InferredAgnostic = Inferred.find(PlatformKind::none);
-  if (InferredAgnostic != Inferred.end()) {
-    switch (InferredAgnostic->second.PlatformAgnostic) {
-    case PlatformAgnosticAvailabilityKind::Deprecated:
-    case PlatformAgnosticAvailabilityKind::UnavailableInSwift:
-    case PlatformAgnosticAvailabilityKind::Unavailable:
-      Attrs.add(createAvailableAttr(PlatformKind::none,
-                                    InferredAgnostic->second, Message, Rename,
-                                    RenameDecl, Context));
-      return;
-
-    case PlatformAgnosticAvailabilityKind::None:
-    case PlatformAgnosticAvailabilityKind::SwiftVersionSpecific:
-    case PlatformAgnosticAvailabilityKind::PackageDescriptionVersionSpecific:
-    case PlatformAgnosticAvailabilityKind::NoAsync:
-      break;
-    }
-  }
-
   // Create an availability attribute for each observed platform and add
   // to ToDecl.
   for (auto &Pair : Inferred) {

lib/Sema/TypeCheckAttr.cpp

@@ -1945,17 +1945,7 @@ void AttributeChecker::visitAvailableAttr(AvailableAttr *attr) {
       AvailabilityInference::availableRange(attr, Ctx);
 
   if (auto *parent = getEnclosingDeclForDecl(D)) {
-    if (auto enclosingUnavailable = parent->getSemanticUnavailableAttr()) {
-      if (!AttrRange.isKnownUnreachable()) {
-        const Decl *enclosingDecl = enclosingUnavailable.value().second;
-        diagnose(D->isImplicit() ? enclosingDecl->getLoc()
-                                 : attr->getLocation(),
-                 diag::availability_decl_more_than_unavailable_enclosing,
-                 D->getDescriptiveKind());
-        diagnose(parent->getLoc(),
-                 diag::availability_decl_more_than_unavailable_enclosing_here);
-      }
-    } else if (auto enclosingAvailable =
+    if (auto enclosingAvailable =
                    parent->getSemanticAvailableRangeAttr()) {
       const AvailableAttr *enclosingAttr = enclosingAvailable.value().first;
       const Decl *enclosingDecl = enclosingAvailable.value().second;

test/ModuleInterface/actor_availability.swift

@@ -1,7 +1,9 @@
 // RUN: %empty-directory(%t)
-// RUN: %target-swift-emit-module-interface(%t/Library.swiftinterface) %s -module-name Library -target %target-swift-abi-5.3-triple
+// RUN: %target-swift-emit-module-interfaces(%t/Library.swiftinterface, %t/Library.private.swiftinterface) %s -module-name Library -target %target-swift-abi-5.3-triple
 // RUN: %target-swift-typecheck-module-from-interface(%t/Library.swiftinterface) -module-name Library
-// RUN: %FileCheck %s < %t/Library.swiftinterface
+// RUN: %target-swift-typecheck-module-from-interface(%t/Library.private.swiftinterface) -module-name Library
+// RUN: %FileCheck %s --check-prefixes=CHECK,CHECK-PUBLIC < %t/Library.swiftinterface
+// RUN: %FileCheck %s --check-prefixes=CHECK,CHECK-PRIVATE < %t/Library.private.swiftinterface
 
 // REQUIRES: VENDOR=apple
 
@@ -33,7 +35,7 @@ public actor ActorWithExplicitAvailability {
 @available(macOS, unavailable)
 public actor UnavailableActor {
   // CHECK: @available(iOS 13.0, tvOS 13.0, watchOS 6.0, *)
-  // CHECK-NEXT: @available(macOS, unavailable)
+  // CHECK-NEXT: @available(macOS, unavailable, introduced: 10.15)
   // CHECK-NEXT: @_semantics("defaultActor") nonisolated final public var unownedExecutor: _Concurrency.UnownedSerialExecutor {
   // CHECK-NEXT:   get
   // CHECK-NEXT: }
@@ -72,9 +74,39 @@ extension Enum {
   @available(macOS, unavailable)
   public actor UnavailableExtensionNestedActor {
     // CHECK: @available(iOS 13.4, tvOS 13.4, watchOS 6.2, *)
-    // CHECK-NEXT: @available(macOS, unavailable)
+    // CHECK-NEXT: @available(macOS, unavailable, introduced: 10.15.4)
     // CHECK-NEXT: @_semantics("defaultActor") nonisolated final public var unownedExecutor: _Concurrency.UnownedSerialExecutor {
     // CHECK-NEXT:   get
     // CHECK-NEXT: }
   }
 }
+
+// CHECK-PUBLIC: @available(macOS, unavailable)
+// CHECK-PUBLIC-NEXT: @available(iOS, unavailable)
+// CHECK-PUBLIC-NEXT: @available(watchOS, unavailable)
+// CHECK-PUBLIC-NEXT: @available(tvOS, unavailable)
+// CHECK-PUBLIC-NEXT: public struct SPIAvailableStruct
+// CHECK-PRIVATE: @_spi_available(macOS, introduced: 10.15.4)
+// CHECK-PRIVATE-NEXT: @_spi_available(iOS, introduced: 13.4)
+// CHECK-PRIVATE-NEXT: @_spi_available(watchOS, introduced: 6.2)
+// CHECK-PRIVATE-NEXT: @_spi_available(tvOS, introduced: 13.4)
+// CHECK-PRIVATE-NEXT: public struct SPIAvailableStruct
+@_spi_available(SwiftStdlib 5.2, *)
+public struct SPIAvailableStruct {
+  // CHECK: #if compiler(>=5.3) && $Actors
+  // CHECK-NEXT: @_hasMissingDesignatedInitializers @available(macOS, unavailable)
+  // CHECK-NEXT: public actor UnavailableNestedActor
+  @available(macOS, unavailable)
+  public actor UnavailableNestedActor {
+    // CHECK-PUBLIC: @available(iOS, unavailable)
+    // CHECK-PUBLIC-NEXT: @available(tvOS, unavailable)
+    // CHECK-PUBLIC-NEXT: @available(watchOS, unavailable)
+    // CHECK-PUBLIC-NEXT: @available(macOS, unavailable)
+    // CHECK-PUBLIC-NEXT: @_semantics("defaultActor") nonisolated final public var unownedExecutor: _Concurrency.UnownedSerialExecutor
+    // CHECK-PRIVATE: @_spi_available(iOS, introduced: 13.4)
+    // CHECK-PRIVATE-NEXT: @_spi_available(tvOS, introduced: 13.4)
+    // CHECK-PRIVATE-NEXT: @_spi_available(watchOS, introduced: 6.2)
+    // CHECK-PRIVATE-NEXT: @_spi_available(macOS, unavailable, introduced: 10.15.4)
+    // CHECK-PRIVATE-NEXT: @_semantics("defaultActor") nonisolated final public var unownedExecutor: _Concurrency.UnownedSerialExecutor
+  }
+}

test/Sema/availability_versions.swift

@@ -1731,12 +1731,11 @@ struct HasUnavailableExtension {
 
 @available(OSX, unavailable)
 extension HasUnavailableExtension {
-    // expected-note@-1 {{enclosing scope has been explicitly marked unavailable here}}
 
   public func inheritsUnavailable() { }
       // expected-note@-1 {{'inheritsUnavailable()' has been explicitly marked unavailable here}}
 
-  @available(OSX 10.9, *) // expected-warning {{instance method cannot be more available than unavailable enclosing scope}}
+  @available(OSX 10.9, *)
   public func moreAvailableButStillUnavailable() { }
       // expected-note@-1 {{'moreAvailableButStillUnavailable()' has been explicitly marked unavailable here}}
 }

test/Sema/generalized_accessors_availability.swift

@@ -131,6 +131,20 @@ func testButtNested(x: inout Butt.Nested) { // expected-error {{'Nested' is unav
   x.$wrapped_modify_more_available = 0 // expected-error {{is unavailable in macOS}}
 }
 
+@available(iOS, unavailable)
+@_spi_available(macOS, introduced: 10.51)
+extension Butt {
+  struct NestedInSPIAvailableExtension {
+    @available(macOS, unavailable)
+    public var unavailable: Int // expected-note {{'unavailable' has been explicitly marked unavailable here}}
+  }
+}
+
+@available(macOS, introduced: 10.51)
+func testButtNested(x: inout Butt.NestedInSPIAvailableExtension) {
+  x.unavailable = 0 // expected-error {{is unavailable in macOS}}
+}
+
 @available(macOS 11.0, *)
 struct LessAvailable {
   @SetterConditionallyAvailable

test/attr/attr_availability_transitive_osx.swift

@@ -105,7 +105,6 @@ extension Outer {
 }
 
 @available(OSX, unavailable)
-// expected-note@+1 {{enclosing scope has been explicitly marked unavailable here}}
 extension Outer {
   // expected-note@+1 {{'outer_osx_init_osx' has been explicitly marked unavailable here}}
   static var outer_osx_init_osx = osx() // OK
@@ -124,7 +123,7 @@ extension Outer {
   }
 
   // This @available should be ignored; inherited unavailability takes precedence
-  @available(OSX 999, *) // expected-warning {{instance method cannot be more available than unavailable enclosing scope}}
+  @available(OSX 999, *)
   // expected-note@+1 {{'osx_more_available_but_still_unavailable_call_osx()' has been explicitly marked unavailable here}}
   func osx_more_available_but_still_unavailable_call_osx() {
     osx() // OK