[Distributed] Explicitly ban a class extending AnyActor as well

Author: ktoso

include/swift/AST/DiagnosticsSema.def

@@ -4495,8 +4495,8 @@ ERROR(actor_inheritance,none,
       (bool))
 
 ERROR(actor_protocol_illegal_inheritance,none,
-      "non-actor type %0 cannot conform to the 'Actor' protocol",
-      (DeclName))
+      "non-actor type %0 cannot conform to the %1 protocol",
+      (DeclName, DeclName))
 ERROR(distributed_actor_conformance_missing_system_type,none,
       "distributed actor %0 does not declare ActorSystem it can be used with.",
       (DeclName))

include/swift/AST/KnownProtocols.def

@@ -59,6 +59,7 @@
     BUILTIN_EXPRESSIBLE_BY_LITERAL_PROTOCOL_WITH_NAME(name, "_" #name)
 
 PROTOCOL(Actor)
+PROTOCOL(AnyActor)
 PROTOCOL(Sequence)
 PROTOCOL(Identifiable)
 PROTOCOL(IteratorProtocol)

lib/IRGen/GenMeta.cpp

@@ -5770,6 +5770,7 @@ SpecialProtocol irgen::getSpecialProtocolID(ProtocolDecl *P) {
   case KnownProtocolKind::Differentiable:
   case KnownProtocolKind::FloatingPoint:
   case KnownProtocolKind::Identifiable:
+  case KnownProtocolKind::AnyActor:
   case KnownProtocolKind::Actor:
   case KnownProtocolKind::DistributedActor:
   case KnownProtocolKind::DistributedActorSystem:

lib/Sema/TypeCheckProtocol.cpp

@@ -6439,7 +6439,19 @@ void TypeChecker::checkConformancesInContext(IterableDeclContext *idc) {
         if (!classDecl->isExplicitActor()) {
           dc->getSelfNominalTypeDecl()
               ->diagnose(diag::actor_protocol_illegal_inheritance,
-                         dc->getSelfNominalTypeDecl()->getName())
+                         dc->getSelfNominalTypeDecl()->getName(),
+                         proto->getName())
+              .fixItReplace(nominal->getStartLoc(), "actor");
+        }
+      }
+    } else if (proto->isSpecificProtocol(KnownProtocolKind::AnyActor)) {
+      if (auto classDecl = dyn_cast<ClassDecl>(nominal)) {
+        if (!classDecl->isExplicitActor() &&
+            !classDecl->isExplicitDistributedActor()) {
+          dc->getSelfNominalTypeDecl()
+              ->diagnose(diag::actor_protocol_illegal_inheritance,
+                         dc->getSelfNominalTypeDecl()->getName(),
+                         proto->getName())
               .fixItReplace(nominal->getStartLoc(), "actor");
         }
       }

stdlib/public/Concurrency/Actor.cpp

@@ -1066,7 +1066,7 @@ static void traceJobQueue(DefaultActorImpl *actor, Job *first) {
 static SWIFT_ATTRIBUTE_ALWAYS_INLINE void traceActorStateTransition(DefaultActorImpl *actor,
     ActiveActorStatus oldState, ActiveActorStatus newState) {
 
-  SWIFT_TASK_DEBUG_LOG("Actor %p transitioned from %#x to %#x (%s)\n", actor,
+  SWIFT_TASK_DEBUG_LOG("Actor %p transitioned from %#x to %#x (%s)", actor,
                        oldState.getOpaqueFlags(), newState.getOpaqueFlags(),
                        __FUNCTION__);
   newState.traceStateChanged(actor);

test/Distributed/actor_protocols.swift

@@ -14,8 +14,9 @@ typealias DefaultDistributedActorSystem = FakeActorSystem
 actor A: Actor {} // ok
 
 class C: Actor, UnsafeSendable {
-  // expected-error@-1{{non-actor type 'C' cannot conform to the 'Actor' protocol}} {{1-6=actor}}
-  // expected-warning@-2{{'UnsafeSendable' is deprecated: Use @unchecked Sendable instead}}
+  // expected-error@-1{{non-actor type 'C' cannot conform to the 'AnyActor' protocol}} {{1-6=actor}}
+  // expected-error@-2{{non-actor type 'C' cannot conform to the 'Actor' protocol}} {{1-6=actor}}
+  // expected-warning@-3{{'UnsafeSendable' is deprecated: Use @unchecked Sendable instead}}
   nonisolated var unownedExecutor: UnownedSerialExecutor {
     fatalError()
   }
@@ -43,10 +44,10 @@ distributed actor DA: DistributedActor {
   typealias ActorSystem = FakeActorSystem
 }
 
-// FIXME(distributed): error reporting is a bit whacky here; needs cleanup
-// expected-error@+2{{actor type 'A2' cannot conform to the 'DistributedActor' protocol. Isolation rules of these actor types are not interchangeable.}}
-// expected-error@+1{{actor type 'A2' cannot conform to the 'DistributedActor' protocol. Isolation rules of these actor types are not interchangeable.}}
 actor A2: DistributedActor {
+// FIXME(distributed): error reporting is a bit whacky here; needs cleanup
+// expected-error@-2{{actor type 'A2' cannot conform to the 'DistributedActor' protocol. Isolation rules of these actor types are not interchangeable.}}
+// expected-error@-3{{actor type 'A2' cannot conform to the 'DistributedActor' protocol. Isolation rules of these actor types are not interchangeable.}}
   nonisolated var id: ID {
     fatalError()
   }
@@ -63,8 +64,9 @@ actor A2: DistributedActor {
   }
 }
 
-// expected-error@+1{{non-distributed actor type 'C2' cannot conform to the 'DistributedActor' protocol}}
-final class C2: DistributedActor {
+final class DA2: DistributedActor {
+// expected-error@-1{{non-actor type 'DA2' cannot conform to the 'AnyActor' protocol}}
+// expected-error@-2{{non-distributed actor type 'DA2' cannot conform to the 'DistributedActor' protocol}}
   nonisolated var id: ID {
     fatalError()
   }
@@ -86,3 +88,19 @@ struct S2: DistributedActor {
   // expected-error@-3{{type 'S2' does not conform to protocol 'Identifiable'}}
 }
 
+// ==== -----------------------------------------------------------------------
+
+actor A3: AnyActor {} // ok
+distributed actor DA3: AnyActor {} // ok
+
+class C3: AnyActor, @unchecked Sendable {
+  // expected-error@-1{{non-actor type 'C3' cannot conform to the 'AnyActor' protocol}} {{1-6=actor}}
+}
+
+struct S3: AnyActor {
+  // expected-error@-1{{non-class type 'S3' cannot conform to class protocol 'AnyActor'}}
+}
+
+enum E3: AnyActor {
+  // expected-error@-1{{non-class type 'E3' cannot conform to class protocol 'AnyActor'}}
+}