AST: Promote OptionalIsolatedParameters feature to baseline.

Author: tshortli

include/swift/Basic/Features.def

@@ -184,7 +184,7 @@ BASELINE_LANGUAGE_FEATURE(FreestandingMacros, 397, "freestanding declaration mac
 SUPPRESSIBLE_LANGUAGE_FEATURE(RetroactiveAttribute, 364, "@retroactive")
 BASELINE_LANGUAGE_FEATURE(ExtensionMacroAttr, 0, "@attached(extension)")
 BASELINE_LANGUAGE_FEATURE(TypedThrows, 413, "Typed throws")
-CONDITIONALLY_SUPPRESSIBLE_LANGUAGE_FEATURE(OptionalIsolatedParameters, 420, "Optional isolated parameters")
+BASELINE_LANGUAGE_FEATURE(OptionalIsolatedParameters, 420, "Optional isolated parameters")
 BASELINE_LANGUAGE_FEATURE(Extern, 0, "@_extern")
 BASELINE_LANGUAGE_FEATURE(ExpressionMacroDefaultArguments, 422, "Expression macro as caller-side default argument")
 BASELINE_LANGUAGE_FEATURE(BuiltinStoreRaw, 0, "Builtin.storeRaw")

lib/AST/ASTPrinter.cpp

@@ -3049,14 +3049,6 @@ static void suppressingFeatureIsolatedAny(PrintOptions &options,
   action();
 }
 
-static void suppressingFeatureOptionalIsolatedParameters(
-    PrintOptions &options,
-    llvm::function_ref<void()> action) {
-  llvm::SaveAndRestore<bool> scope(
-      options.SuppressOptionalIsolatedParams, true);
-  action();
-}
-
 static void
 suppressingFeatureSendingArgsAndResults(PrintOptions &options,
                                         llvm::function_ref<void()> action) {

lib/AST/FeatureSet.cpp

@@ -73,25 +73,6 @@ static bool usesFeatureRetroactiveAttribute(Decl *decl) {
       [](const InheritedEntry &entry) { return entry.isRetroactive(); });
 }
 
-static bool usesFeatureOptionalIsolatedParameters(Decl *decl) {
-  auto *value = dyn_cast<ValueDecl>(decl);
-  if (!value)
-    return false;
-
-  auto *paramList = getParameterList(value);
-  if (!paramList)
-    return false;
-
-  for (auto param : *paramList) {
-    if (param->isIsolated()) {
-      auto paramType = param->getInterfaceType();
-      return !paramType->getOptionalObjectType().isNull();
-    }
-  }
-
-  return false;
-}
-
 static bool usesFeatureAssociatedTypeImplements(Decl *decl) {
   return isa<TypeDecl>(decl) && decl->getAttrs().hasAttribute<ImplementsAttr>();
 }

stdlib/public/Concurrency/AsyncIteratorProtocol.swift

@@ -133,10 +133,6 @@ extension AsyncIteratorProtocol {
   @available(SwiftStdlib 6.0, *)
   @inlinable
   public mutating func next() async throws(Failure) -> Element? {
-#if $OptionalIsolatedParameters
     return try await next(isolation: nil)
-#else
-    fatalError("unsupported compiler")
-#endif
   }
 }

stdlib/public/Concurrency/Clock.swift

@@ -68,7 +68,6 @@ extension Clock {
   ///       }
   @available(SwiftStdlib 5.7, *)
   @_alwaysEmitIntoClient
-  @_allowFeatureSuppression(OptionalIsolatedParameters)
   public func measure(
     isolation: isolated (any Actor)? = #isolation,
     _ work: () async throws -> Void

test/Concurrency/sending_asynciteratornext_typechecker_error.swift

@@ -52,11 +52,7 @@ extension AsyncIteratorProtocol {
   @available(SwiftStdlib 6.0, *)
   @inlinable
   public mutating func next() async throws(Failure) -> sending Element? {
-#if $OptionalIsolatedParameters
     return try await next(isolation: nil)
-#else
-    fatalError("unsupported compiler")
-#endif
   }
 }
 

test/Concurrency/sending_conditional_suppression.swift

@@ -206,7 +206,6 @@ public struct TestInStruct {
 // Make sure that we emit compiler(>= 5.3) when emitting the suppressing check
 // to make sure we do not fail if we fail to parse sending in the if block.
 
-// CHECK-LABEL: #if compiler(>=5.3) && $OptionalIsolatedParameters // Suppression Count: 24
 // CHECK-NEXT: #if compiler(>=5.3) && $SendingArgsAndResults // Suppression Count: 25
 // CHECK-NEXT: @inlinable public func withCheckedContinuation<T>(isolation: isolated (any _Concurrency.Actor)? = #isolation, function: Swift.String = #function, _ body: (_Concurrency.CheckedContinuation<T, Swift.Never>) -> Swift.Void) async -> sending T {
 // CHECK-NEXT:   fatalError()
@@ -216,7 +215,6 @@ public struct TestInStruct {
 // CHECK-NEXT:   fatalError()
 // CHECK-NEXT: }
 // CHECK-NEXT: #endif
-// CHECK-NEXT: #endif
 @inlinable public func withCheckedContinuation<T>(
   isolation: isolated (any _Concurrency.Actor)? = #isolation,
   function: String = #function,