[Concurrency] Implicit global actor attributes imply Sendable.

lib/Sema/TypeCheckConcurrency.cpp

@@ -6055,7 +6055,7 @@ ProtocolConformance *swift::deriveImplicitSendableConformance(
   }
 
   // A non-protocol type with a global actor is implicitly Sendable.
-  if (nominal->getGlobalActorAttr()) {
+  if (getActorIsolation(nominal).isGlobalActor()) {
     // Form the implicit conformance to Sendable.
     return formConformance(nullptr);
   }

test/Concurrency/sendable_checking.swift

@@ -407,3 +407,23 @@ struct DowngradeForPreconcurrency {
     }
   }
 }
+
+@available(SwiftStdlib 5.1, *)
+@MainActor protocol InferMainActor {}
+
+@available(SwiftStdlib 5.1, *)
+struct ImplicitSendableViaMain: InferMainActor {}
+
+@available(SwiftStdlib 5.1, *)
+extension ImplicitSendableViaMain {
+  nonisolated func capture() {
+    Task { @MainActor in
+      _ = self
+    }
+  }
+}
+
+@available(SwiftStdlib 5.1, *)
+struct TestImplicitSendable: Sendable {
+  var x: ImplicitSendableViaMain
+}

validation-test/Sema/SwiftUI/rdar76252310.swift

@@ -1,15 +1,20 @@
-// RUN: %target-typecheck-verify-swift -target %target-cpu-apple-macosx10.15 -swift-version 5 -strict-concurrency=targeted
+// RUN: %target-typecheck-verify-swift -target %target-cpu-apple-macosx10.15 -swift-version 5 -strict-concurrency=complete
 
 // REQUIRES: objc_interop
 // REQUIRES: OS=macosx
 
 import SwiftUI
 
-class Visibility: ObservableObject { // expected-note 2{{class 'Visibility' does not conform to the 'Sendable' protocol}}
+@MainActor
+class Visibility: ObservableObject {
+    nonisolated init() {}
+
     @Published var yes = false // some nonsense
 }
 
-struct CoffeeTrackerView: View { // expected-note 4{{consider making struct 'CoffeeTrackerView' conform to the 'Sendable' protocol}}
+struct CoffeeTrackerView: View {
+    nonisolated init() {}
+
     @ObservedObject var showDrinkList: Visibility = Visibility()
 
     var storage: Visibility = Visibility()
@@ -34,24 +39,16 @@ func fromMainActor() async {
 
 
 func fromConcurrencyAware() async {
-  // expected-note@+3 {{calls to initializer 'init()' from outside of its actor context are implicitly asynchronous}}
-  // expected-warning@+2 {{expression is 'async' but is not marked with 'await'}}
-  // expected-warning@+1 {{non-sendable type 'CoffeeTrackerView' returned by call to main actor-isolated function cannot cross actor boundary}}
-  let view = CoffeeTrackerView()
+  let view = CoffeeTrackerView() // synthesized 'init' is 'nonisolated'
 
-  // expected-warning@+4 {{non-sendable type 'CoffeeTrackerView' passed in implicitly asynchronous call to main actor-isolated property 'body' cannot cross actor boundary}}
   // expected-note@+3 {{property access is 'async'}}
   // expected-warning@+2 {{non-sendable type 'some View' in implicitly asynchronous access to main actor-isolated property 'body' cannot cross actor boundary}}
   // expected-warning@+1 {{expression is 'async' but is not marked with 'await'}}
   _ = view.body
 
-  // expected-warning@+4 {{non-sendable type 'CoffeeTrackerView' passed in implicitly asynchronous call to main actor-isolated property 'showDrinkList' cannot cross actor boundary}}
-  // expected-note@+3 {{property access is 'async'}}
-  // expected-warning@+2 {{non-sendable type 'Visibility' in implicitly asynchronous access to main actor-isolated property 'showDrinkList' cannot cross actor boundary}}
+  // expected-note@+2 {{property access is 'async'}}
   // expected-warning@+1 {{expression is 'async' but is not marked with 'await'}}
   _ = view.showDrinkList
 
-  // expected-warning@+2 {{non-sendable type 'CoffeeTrackerView' passed in implicitly asynchronous call to main actor-isolated property 'storage' cannot cross actor boundary}}
-  // expected-warning@+1 {{non-sendable type 'Visibility' in implicitly asynchronous access to main actor-isolated property 'storage' cannot cross actor boundary}}
-  _ = await view.storage
+  _ = view.storage
 }