[Distributed] Add test case covering #58663 explicitly

Author: ktoso

lib/Sema/TypeCheckConcurrency.cpp

@@ -3001,11 +3001,6 @@ void swift::checkTopLevelActorIsolation(TopLevelCodeDecl *decl) {
 }
 
 void swift::checkFunctionActorIsolation(AbstractFunctionDecl *decl) {
-  if (decl->hasName()) {
-    fprintf(stderr, "[%s:%d] (%s) HERE\n", __FILE__, __LINE__, __FUNCTION__);
-    decl->getDeclContext()->dumpContext();
-  }
-
   // Disable this check for @LLDBDebuggerFunction functions.
   if (decl->getAttrs().hasAttribute<LLDBDebuggerFunctionAttr>())
     return;

lib/Sema/TypeCheckDeclPrimary.cpp

@@ -3391,29 +3391,4 @@ void TypeChecker::checkParameterList(ParameterList *params,
     // Check for duplicate parameter names.
     diagnoseDuplicateDecls(*params);
   }
-
-//  if (auto proto = dyn_cast<ProtocolDecl>(owner->getParent())) {
-//    fprintf(stderr, "[%s:%d] (%s) IS PROTO: %s\n", __FILE__, __LINE__, __FUNCTION__, proto->getNameStr().str().c_str());
-//    proto->dump();
-//    auto p = owner->getASTContext().getProtocol(KnownProtocolKind::DistributedActor);
-//
-//    for (auto member : proto->getMembers()) {
-//      auto func = dyn_cast<AbstractFunctionDecl>(member);
-//      if (!func)
-//        continue;
-//      if (!func->isDistributed())
-//        continue;
-//      auto serializationRequirementTy = getConcreteReplacementForProtocolActorSystemType(func);
-//
-//      if (serializationRequirementTy) {
-//        checkDistributedFunction(func)
-//      }
-//    }
-//
-//    if (auto x = getDistributedSerializationRequirementType(proto, p)) {
-//      fprintf(stderr, "[%s:%d] (%s) REQS: %p\n", __FILE__, __LINE__,
-//              __FUNCTION__, x);
-//      x.dump();
-//    }
-//  }
 }

test/Distributed/distributed_actor_system_missing.swift

@@ -18,3 +18,16 @@ distributed actor DA {
   // Note to add the typealias is diagnosed on the protocol:
   // _Distributed.DistributedActor:3:20: note: diagnostic produced elsewhere: protocol requires nested type 'ActorSystem'; do you want to add it?
 }
+
+
+// When an actor declares a typealias for a system, but that system does not exist,
+// we need to fail gracefully, rather than crash trying to use the non-existing type.
+//
+// Test case for: https://github.com/apple/swift/issues/58663
+distributed actor Server { // expected-error 2 {{distributed actor 'Server' does not declare ActorSystem it can be used with.}}
+  // expected-note@-1{{you can provide a module-wide default actor system by declaring:}}
+  typealias ActorSystem = DoesNotExistDataSystem
+  // expected-error@-1{{cannot find type 'DoesNotExistDataSystem' in scope}}
+  typealias SerializationRequirement = any Codable
+  distributed func send() { }
+}

test/Distributed/distributed_protocols_distributed_func_serialization_requirements.swift

@@ -66,7 +66,6 @@ distributed actor ProtocolWithChecksSeqReqDA: ProtocolWithChecksSeqReq {
   distributed func testAT() async throws -> NotCodable { .init() }
 }
 
-
 extension NoSerializationRequirementYet {
   // Still OK, we don't know if this will be implementable or not
   distributed func test2() -> NotCodable {