Incorrect location of 'async' for protocol in actor's fix suggestion (#69246)

* implementing changes and tests

* added unit test using throws

* adding test with distributed actor

* moved distributed-actor tests to another file

* revert import Distributed

Author: dancamarotto

lib/Sema/TypeCheckProtocol.cpp

@@ -3288,12 +3288,6 @@ ConformanceChecker::checkActorIsolation(ValueDecl *requirement,
       } else if (requirementAbstractFunc->getThrowsLoc().isValid()) {
         // Insert before the "throws" (we only have async)".
         insertLoc = requirementAbstractFunc->getThrowsLoc();
-      } else if (auto requirementFunc =
-                     dyn_cast<FuncDecl>(requirementAbstractFunc)) {
-        // Insert before the result type, if there is one.
-        if (auto resultTypeRepr = requirementFunc->getResultTypeRepr()) {
-          insertLoc = resultTypeRepr->getStartLoc();
-        }
       }
 
       // Insert after the parentheses.

test/decl/class/actor/conformance.swift

@@ -22,6 +22,12 @@ protocol SyncProtocol {
 
   func syncMethodC() -> Int
 
+  func syncMethodE() -> Void // expected-note{{mark the protocol requirement 'syncMethodE()' 'async' to allow actor-isolated conformances}}{{21-21= async}}
+
+  func syncMethodF(param: String) -> Int // expected-note{{mark the protocol requirement 'syncMethodF(param:)' 'async' to allow actor-isolated conformances}}{{34-34= async}}
+
+  func syncMethodG() throws -> Void // expected-note{{mark the protocol requirement 'syncMethodG()' 'async' to allow actor-isolated conformances}}{{22-22=async }}
+
   subscript (index: Int) -> String { get } // expected-note{{'subscript(_:)' declared here}}
 
   static func staticMethod()
@@ -44,6 +50,18 @@ actor OtherActor: SyncProtocol {
   // FIXME: Consider suggesting nonisolated if this didn't match.
   nonisolated func syncMethodC() -> Int { 5 }
 
+  func syncMethodE() -> Void { }
+  // expected-error@-1{{actor-isolated instance method 'syncMethodE()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-note@-2{{add 'nonisolated' to 'syncMethodE()' to make this instance method not isolated to the actor}}{{3-3=nonisolated }}
+
+  func syncMethodF(param: String) -> Int { 5 }
+  // expected-error@-1{{actor-isolated instance method 'syncMethodF(param:)' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-note@-2{{add 'nonisolated' to 'syncMethodF(param:)' to make this instance method not isolated to the actor}}{{3-3=nonisolated }}
+
+  func syncMethodG() { }
+  // expected-error@-1{{actor-isolated instance method 'syncMethodG()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-note@-2{{add 'nonisolated' to 'syncMethodG()' to make this instance method not isolated to the actor}}{{3-3=nonisolated }}
+
   subscript (index: Int) -> String { "\(index)" }
   // expected-error@-1{{actor-isolated subscript 'subscript(_:)' cannot be used to satisfy nonisolated protocol requirement}}
   // expected-note@-2{{add 'nonisolated' to 'subscript(_:)' to make this subscript not isolated to the actor}}{{3-3=nonisolated }}
@@ -77,4 +95,4 @@ actor A2: Initializers {
   init(int: Int) { }
 
   func withBells() async -> A2 { self }
-}
+}

test/decl/protocol/special/DistributedActor.swift

@@ -74,3 +74,16 @@ func testConformance() {
   acceptDistributedActor(D1.self)
   acceptAnyActor(D1.self)
 }
+
+// https://github.com/apple/swift/issues/69244
+protocol P {
+  func foo() -> Void
+  // expected-note@-1{{mark the protocol requirement 'foo()' 'async throws' to allow actor-isolated conformances}}{{13-13= async throws}}
+}
+
+distributed actor A: P {
+  typealias ActorSystem = LocalTestingDistributedActorSystem
+  distributed func foo() { }
+  // expected-error@-1{{actor-isolated distributed instance method 'foo()' cannot be used to satisfy nonisolated protocol requirement}}
+}
+// ---