Merge pull request #61117 from apple/revert-60790-rdar99047747

Revert "[Freestanding] Disable checked continuations."

Author: swift-ci

stdlib/public/Concurrency/CheckedContinuation.swift

@@ -16,7 +16,6 @@ import Swift
 @_silgen_name("swift_continuation_logFailedCheck")
 internal func logFailedCheck(_ message: UnsafeRawPointer)
 
-#if !SWIFT_STDLIB_TASK_TO_THREAD_MODEL_CONCURRENCY
 /// Implementation class that holds the `UnsafeContinuation` instance for
 /// a `CheckedContinuation`.
 @available(SwiftStdlib 5.1, *)
@@ -83,9 +82,7 @@ internal final class CheckedContinuationCanary: @unchecked Sendable {
     }
   }
 }
-#endif
 
-#if !SWIFT_STDLIB_TASK_TO_THREAD_MODEL_CONCURRENCY
 /// A mechanism to interface
 /// between synchronous and asynchronous code,
 /// logging correctness violations.
@@ -299,65 +296,4 @@ public func withCheckedThrowingContinuation<T>(
     body(CheckedContinuation(continuation: $0, function: function))
   }
 }
-#else
-@available(SwiftStdlib 5.1, *)
-@available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-public struct CheckedContinuation<T, E: Error>: Sendable {
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public init(continuation: UnsafeContinuation<T, E>, function: String = #function) {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
-  
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public func resume(returning value: __owned T) {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
-  
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public func resume(throwing error: __owned E) {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
-}
-@available(SwiftStdlib 5.1, *)
-@available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-extension CheckedContinuation {
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public func resume<Er: Error>(with result: Result<T, Er>) where E == Error {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
-
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public func resume(with result: Result<T, E>) {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
 
-  @available(SwiftStdlib 5.1, *)
-  @available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-  public func resume() where T == Void {
-    fatalError("Unavailable in task-to-thread concurrency model")
-  }
-}
-
-@available(SwiftStdlib 5.1, *)
-@available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-public func withCheckedContinuation<T>(
-    function: String = #function,
-    _ body: (CheckedContinuation<T, Never>) -> Void
-) async -> T {
-  fatalError("Unavailable in task-to-thread concurrency model")
-}
-
-@available(SwiftStdlib 5.1, *)
-@available(*, unavailable, message: "Unavailable in task-to-thread concurrency model")
-public func withCheckedThrowingContinuation<T>(
-    function: String = #function,
-    _ body: (CheckedContinuation<T, Error>) -> Void
-) async throws -> T {
-  fatalError("Unavailable in task-to-thread concurrency model")
-}
-#endif

test/stdlib/freestanding_diags_stdlib.swift

@@ -24,13 +24,6 @@ func foo() async {
   asyncDetached { () async -> () in } // expected-error{{Unavailable in task-to-thread concurrency model}}
   asyncDetached { () async throws -> () in } // expected-error{{Unavailable in task-to-thread concurrency model}}
   _ = MainActor.self // expected-error{{Unavailable in task-to-thread concurrency model}}
-  let _: Int = await withCheckedContinuation { _ in } // expected-error{{Unavailable in task-to-thread concurrency model}}
-  do {
-  let _: Int = try await withCheckedThrowingContinuation { _ in } // expected-error{{Unavailable in task-to-thread concurrency model}}
-  } catch let error {
-    _ = error
-  }
-  _ = CheckedContinuation<Int, Never>.self // expected-error{{Unavailable in task-to-thread concurrency model}}
 }
 
 func foo2(