[6.1] ConformanceChecker: Make actor_isolated_witness call out the protocol

include/swift/AST/DiagnosticsSema.def

@@ -42,6 +42,8 @@ NOTE(opaque_return_type_declared_here,none,
      "opaque return type declared here", ())
 NOTE(default_value_declared_here,none,
      "default value declared here", ())
+NOTE(protocol_requirement_declared_here,none,
+     "requirement %0 declared here", (const ValueDecl *))
 
 //------------------------------------------------------------------------------
 // MARK: Constraint solver diagnostics
@@ -5643,9 +5645,10 @@ NOTE(shared_state_make_immutable,none,
 NOTE(shared_state_nonisolated_unsafe,none,
      "disable concurrency-safety checks if accesses are protected by an external synchronization mechanism", (const ValueDecl *))
 ERROR(actor_isolated_witness,none,
-     "%select{|distributed }0%1 %kind2 cannot be used to satisfy %3 protocol "
-     "requirement",
-     (bool, ActorIsolation, const ValueDecl *, ActorIsolation))
+     "%select{|distributed }0%1 %kind2 cannot be used to satisfy %3 "
+     "requirement from protocol %base4",
+     (bool, ActorIsolation, const ValueDecl *, ActorIsolation,
+      const ValueDecl *))
 ERROR(actor_cannot_conform_to_global_actor_protocol,none,
       "actor %0 cannot conform to global actor isolated protocol %1",
       (Type, Type))

lib/Sema/TypeCheckProtocol.cpp

@@ -3396,10 +3396,12 @@ ConformanceChecker::checkActorIsolation(ValueDecl *requirement,
 
   // Complain that this witness cannot conform to the requirement due to
   // actor isolation.
-  witness->diagnose(diag::actor_isolated_witness,
-                    isDistributed && !isDistributedDecl(witness),
-                    refResult.isolation, witness, requirementIsolation)
-    .limitBehaviorUntilSwiftVersion(behavior, 6);
+  witness
+      ->diagnose(diag::actor_isolated_witness,
+                 isDistributed && !isDistributedDecl(witness),
+                 refResult.isolation, witness, requirementIsolation,
+                 Conformance->getProtocol())
+      .limitBehaviorUntilSwiftVersion(behavior, 6);
 
   // If we need 'distributed' on the witness, add it.
   if (missingOptions.contains(MissingFlags::WitnessDistributed)) {
@@ -3437,8 +3439,12 @@ ConformanceChecker::checkActorIsolation(ValueDecl *requirement,
   // If there are remaining options, they are missing async/throws on the
   // requirement itself. If we have a source location for the requirement,
   // provide those in a note.
-  if (missingOptions && requirement->getLoc().isValid() &&
-      isa<AbstractFunctionDecl>(requirement)) {
+
+  if (requirement->getLoc().isInvalid()) {
+    return std::nullopt;
+  }
+
+  if (missingOptions && isa<AbstractFunctionDecl>(requirement)) {
     int suggestAddingModifiers = 0;
     std::string modifiers;
     if (missingOptions.contains(MissingFlags::RequirementAsync)) {
@@ -3484,7 +3490,8 @@ ConformanceChecker::checkActorIsolation(ValueDecl *requirement,
         diag.fixItInsert(insertLoc, modifiers);
     }
   } else {
-    requirement->diagnose(diag::decl_declared_here, requirement);
+    requirement->diagnose(diag::protocol_requirement_declared_here,
+                          requirement);
   }
 
   return std::nullopt;

test/Concurrency/actor_isolation.swift

@@ -1508,7 +1508,7 @@ protocol SGA_Proto {
 // try to override a MA method with inferred isolation from a protocol requirement
 class SGA_MA: MA, SGA_Proto {
   // expected-error@+2 {{call to global actor 'SomeGlobalActor'-isolated global function 'onions_sga()' in a synchronous main actor-isolated context}}
-  // expected-warning@+1 {{main actor-isolated instance method 'method()' cannot be used to satisfy global actor 'SomeGlobalActor'-isolated protocol requirement}}
+  // expected-warning@+1 {{main actor-isolated instance method 'method()' cannot be used to satisfy global actor 'SomeGlobalActor'-isolated requirement from protocol 'SGA_Proto'}}
   override func method() { onions_sga() }
   // expected-note@-1{{add 'nonisolated' to 'method()' to make this instance method not isolated to the actor}}{{3-3=nonisolated }}
 }
@@ -1612,13 +1612,13 @@ class OverridesNonsiolatedInit: SuperWithNonisolatedInit {
 class NonSendable {}
 
 protocol NonisolatedProtocol {
-  var ns: NonSendable { get } // expected-note {{'ns' declared here}}
+  var ns: NonSendable { get } // expected-note {{requirement 'ns' declared here}}
 }
 
 actor ActorWithNonSendableLet: NonisolatedProtocol {
   // expected-note@-1{{add '@preconcurrency' to the 'NonisolatedProtocol' conformance to defer isolation checking to run time}}{{32-32=@preconcurrency }}
 
-  // expected-warning@+1 {{actor-isolated property 'ns' cannot be used to satisfy nonisolated protocol requirement; this is an error in the Swift 6 language mode}}
+  // expected-warning@+1 {{actor-isolated property 'ns' cannot be used to satisfy nonisolated requirement from protocol 'NonisolatedProtocol'; this is an error in the Swift 6 language mode}}
   let ns = NonSendable()
 }
 

test/Concurrency/actor_isolation_unsafe.swift

@@ -40,12 +40,12 @@ struct S3_P1: P1 {
 
 struct S4_P1_not_quietly: P1 {
   @SomeGlobalActor func onMainActor() { }
-  // expected-warning @-1 {{global actor 'SomeGlobalActor'-isolated instance method 'onMainActor()' cannot be used to satisfy main actor-isolated protocol requirement}}
+  // expected-warning @-1 {{global actor 'SomeGlobalActor'-isolated instance method 'onMainActor()' cannot be used to satisfy main actor-isolated requirement from protocol 'P1'}}
 }
 
 @SomeGlobalActor
 struct S4_P1: P1 {
-  @SomeGlobalActor func onMainActor() { } // expected-warning{{global actor 'SomeGlobalActor'-isolated instance method 'onMainActor()' cannot be used to satisfy main actor-isolated protocol requirement}}
+  @SomeGlobalActor func onMainActor() { } // expected-warning{{global actor 'SomeGlobalActor'-isolated instance method 'onMainActor()' cannot be used to satisfy main actor-isolated requirement from protocol 'P1'}}
 }
 
 // expected-warning@+1 {{'(unsafe)' global actors are deprecated; use '@preconcurrency' instead}}

test/Concurrency/global_actor_inference.swift

@@ -120,14 +120,14 @@ func testNotAllInP1(nap1: NotAllInP1) { // expected-note{{add '@SomeGlobalActor'
 // Make sure we don't infer 'nonisolated' for stored properties.
 @MainActor
 protocol Interface {
-  nonisolated var baz: Int { get } // expected-note{{'baz' declared here}}
+  nonisolated var baz: Int { get } // expected-note{{requirement 'baz' declared here}}
 }
 
 @MainActor
 class Object: Interface {
   // expected-note@-1{{add '@preconcurrency' to the 'Interface' conformance to defer isolation checking to run time}}{{15-15=@preconcurrency }}
 
-  var baz: Int = 42 // expected-warning{{main actor-isolated property 'baz' cannot be used to satisfy nonisolated protocol requirement}}
+  var baz: Int = 42 // expected-warning{{main actor-isolated property 'baz' cannot be used to satisfy nonisolated requirement from protocol 'Interface'}}
 }
 
 

test/Concurrency/global_actor_inference_swift6.swift

@@ -176,7 +176,7 @@ struct S3: InferenceConflict {
 
 extension S3 {
   func f() { }
-  // expected-error@-1{{global actor 'SomeGlobalActor'-isolated instance method 'f()' cannot be used to satisfy main actor-isolated protocol requirement}}
+  // expected-error@-1{{global actor 'SomeGlobalActor'-isolated instance method 'f()' cannot be used to satisfy main actor-isolated requirement from protocol 'InferMainActorInherited'}}
   //expected-note@-2{{add 'nonisolated' to 'f()' to make this instance method not isolated to the actor}}
 }
 
@@ -208,7 +208,7 @@ class C2: MainActorSuperclass, InferenceConflictWithSuperclass {
   func f() {}
 
   func g() {}
-  // expected-error@-1 {{main actor-isolated instance method 'g()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1 {{main actor-isolated instance method 'g()' cannot be used to satisfy nonisolated requirement from protocol 'InferenceConflictWithSuperclass'}}
   // expected-note@-2 {{add 'nonisolated' to 'g()' to make this instance method not isolated to the actor}}
 }
 

test/Concurrency/preconcurrency_conformances.swift

@@ -107,7 +107,7 @@ final class K : @preconcurrency Initializable {
 @MainActor
 final class MainActorK: Initializable {
   // expected-note@-1{{add '@preconcurrency' to the 'Initializable' conformance to defer isolation checking to run time}}{{25-25=@preconcurrency }}
-  init() { } // expected-warning{{main actor-isolated initializer 'init()' cannot be used to satisfy nonisolated protocol requirement}}
+  init() { } // expected-warning{{main actor-isolated initializer 'init()' cannot be used to satisfy nonisolated requirement from protocol 'Initializable'}}
   // expected-note@-1{{add 'nonisolated' to 'init()' to make this initializer not isolated to the actor}}
 }
 
@@ -130,7 +130,7 @@ struct GlobalActor {
 protocol WithIndividuallyIsolatedRequirements {
   @MainActor var a: Int { get set }
   @GlobalActor var b: Int { get set }
-  // expected-note@-1 {{'b' declared here}}
+  // expected-note@-1 {{requirement 'b' declared here}}
 
   @GlobalActor func test()
   // expected-note@-1 {{mark the protocol requirement 'test()' 'async' to allow actor-isolated conformances}}
@@ -144,21 +144,21 @@ do {
     var a: Int = 42
 
     @MainActor var b: Int {
-      // expected-warning@-1 {{main actor-isolated property 'b' cannot be used to satisfy global actor 'GlobalActor'-isolated protocol requirement}}
+      // expected-warning@-1 {{main actor-isolated property 'b' cannot be used to satisfy global actor 'GlobalActor'-isolated requirement from protocol 'WithIndividuallyIsolatedRequirements'}}
       get { 0 }
       set {}
     }
 
     @MainActor func test() {
-      // expected-warning@-1 {{main actor-isolated instance method 'test()' cannot be used to satisfy global actor 'GlobalActor'-isolated protocol requirement}}
+      // expected-warning@-1 {{main actor-isolated instance method 'test()' cannot be used to satisfy global actor 'GlobalActor'-isolated requirement from protocol 'WithIndividuallyIsolatedRequirements'}}
     }
   }
 }
 
 @MainActor
 protocol WithNonIsolated {
   var prop: Int { get set }
-  // expected-note@-1 {{'prop' declared here}}
+  // expected-note@-1 {{requirement 'prop' declared here}}
   nonisolated func test()
   // expected-note@-1 {{mark the protocol requirement 'test()' 'async' to allow actor-isolated conformances}}
 }
@@ -168,10 +168,10 @@ do {
     // expected-warning@-1 {{@preconcurrency attribute on conformance to 'WithNonIsolated' has no effect}}{{38-54=}}
 
     @GlobalActor var prop: Int = 42
-    // expected-warning@-1 {{global actor 'GlobalActor'-isolated property 'prop' cannot be used to satisfy main actor-isolated protocol requirement}}
+    // expected-warning@-1 {{global actor 'GlobalActor'-isolated property 'prop' cannot be used to satisfy main actor-isolated requirement from protocol 'WithNonIsolated'}}
 
     @MainActor func test() {}
-    // expected-warning@-1 {{main actor-isolated instance method 'test()' cannot be used to satisfy nonisolated protocol requirement}}
+    // expected-warning@-1 {{main actor-isolated instance method 'test()' cannot be used to satisfy nonisolated requirement from protocol 'WithNonIsolated'}}
   }
 }
 

test/Concurrency/predates_concurrency.swift

@@ -235,7 +235,7 @@ extension MainActorPreconcurrency: NotIsolated {
   // expected-complete-tns-note@-2{{add '@preconcurrency' to the 'NotIsolated' conformance to defer isolation checking to run time}}{{36-36=@preconcurrency }}
 
   func requirement() {}
-  // expected-complete-tns-warning@-1 {{main actor-isolated instance method 'requirement()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-complete-tns-warning@-1 {{main actor-isolated instance method 'requirement()' cannot be used to satisfy nonisolated requirement from protocol 'NotIsolated'}}
   // expected-complete-tns-note@-2 {{add 'nonisolated' to 'requirement()' to make this instance method not isolated to the actor}}
   // expected-complete-tns-note@-3 {{calls to instance method 'requirement()' from outside of its actor context are implicitly asynchronous}}
 

test/Distributed/distributed_protocol_isolation.swift

@@ -109,22 +109,22 @@ distributed actor Nope1_StrictlyLocal: StrictlyLocal {
   // expected-note@-1{{add '@preconcurrency' to the 'StrictlyLocal' conformance to defer isolation checking to run time}}
 
   func local() {}
-  // expected-error@-1{{distributed actor-isolated instance method 'local()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{distributed actor-isolated instance method 'local()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
   // expected-note@-2{{add 'nonisolated' to 'local()' to make this instance method not isolated to the actor}}
   func localThrows() throws {}
-  // expected-error@-1{{distributed actor-isolated instance method 'localThrows()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{distributed actor-isolated instance method 'localThrows()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
   // expected-note@-2{{add 'nonisolated' to 'localThrows()' to make this instance method not isolated to the actor}}
   func localAsync() async {}
-  // expected-error@-1{{distributed actor-isolated instance method 'localAsync()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{distributed actor-isolated instance method 'localAsync()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
   // expected-note@-2{{add 'nonisolated' to 'localAsync()' to make this instance method not isolated to the actor}}
 }
 distributed actor Nope2_StrictlyLocal: StrictlyLocal {
   distributed func local() {}
-  // expected-error@-1{{actor-isolated distributed instance method 'local()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated distributed instance method 'local()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
   distributed func localThrows() throws {}
-  // expected-error@-1{{actor-isolated distributed instance method 'localThrows()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated distributed instance method 'localThrows()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
   distributed func localAsync() async {}
-  // expected-error@-1{{actor-isolated distributed instance method 'localAsync()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated distributed instance method 'localAsync()' cannot be used to satisfy nonisolated requirement from protocol 'StrictlyLocal'}}
 }
 distributed actor OK_StrictlyLocal: StrictlyLocal {
   nonisolated func local() {}
@@ -162,7 +162,7 @@ distributed actor Nope1_AsyncThrowsAll: AsyncThrowsAll {
   // expected-note@-1{{add '@preconcurrency' to the 'AsyncThrowsAll' conformance to defer isolation checking to run time}}
 
   func maybe(param: String, int: Int) async throws -> Int { 111 }
-  // expected-error@-1{{distributed actor-isolated instance method 'maybe(param:int:)' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{distributed actor-isolated instance method 'maybe(param:int:)' cannot be used to satisfy nonisolated requirement from protocol 'AsyncThrowsAll'}}
   // expected-note@-2{{add 'nonisolated' to 'maybe(param:int:)' to make this instance method not isolated to the actor}}
   // expected-note@-3{{add 'distributed' to 'maybe(param:int:)' to make this instance method satisfy the protocol requirement}}
 }
@@ -209,7 +209,7 @@ distributed actor DA_TerminationWatchingA: TerminationWatchingA {
   // expected-note@-1{{add '@preconcurrency' to the 'TerminationWatchingA' conformance to defer isolation checking to run time}}
 
   func terminated(a: String) { }
-  // expected-error@-1{{distributed actor-isolated instance method 'terminated(a:)' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{distributed actor-isolated instance method 'terminated(a:)' cannot be used to satisfy nonisolated requirement from protocol 'TerminationWatchingA'}}
   // expected-note@-2{{add 'nonisolated' to 'terminated(a:)' to make this instance method not isolated to the actor}}
 }
 

test/decl/class/actor/conformance.swift

@@ -15,8 +15,8 @@ extension MyActor: AsyncProtocol {
 }
 
 protocol SyncProtocol {
-  var propertyA: Int { get } // expected-note{{'propertyA' declared here}}
-  var propertyB: Int { get set } // expected-note{{'propertyB' declared here}}
+  var propertyA: Int { get } // expected-note{{requirement 'propertyA' declared here}}
+  var propertyB: Int { get set } // expected-note{{requirement 'propertyB' declared here}}
 
   func syncMethodA() // expected-note{{mark the protocol requirement 'syncMethodA()' 'async' to allow actor-isolated conformances}}{{21-21= async}}
 
@@ -28,7 +28,7 @@ protocol SyncProtocol {
 
   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}}
+  subscript (index: Int) -> String { get } // expected-note{{requirement 'subscript(_:)' declared here}}
 
   static func staticMethod()
   static var staticProperty: Int { get }
@@ -39,33 +39,33 @@ actor OtherActor: SyncProtocol {
   // expected-note@-1{{add '@preconcurrency' to the 'SyncProtocol' conformance to defer isolation checking to run time}}{{19-19=@preconcurrency }}
 
   var propertyB: Int = 17
-  // expected-error@-1{{actor-isolated property 'propertyB' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated property 'propertyB' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
 
   var propertyA: Int { 17 }
-  // expected-error@-1{{actor-isolated property 'propertyA' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated property 'propertyA' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
 
   func syncMethodA() { }
-  // expected-error@-1{{actor-isolated instance method 'syncMethodA()' cannot be used to satisfy nonisolated protocol requirement}}
+  // expected-error@-1{{actor-isolated instance method 'syncMethodA()' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
   // expected-note@-2{{add 'nonisolated' to 'syncMethodA()' to make this instance method not isolated to the actor}}{{3-3=nonisolated }}
 
   // nonisolated methods are okay.
   // 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-error@-1{{actor-isolated instance method 'syncMethodE()' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
   // 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-error@-1{{actor-isolated instance method 'syncMethodF(param:)' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
   // 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-error@-1{{actor-isolated instance method 'syncMethodG()' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
   // 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-error@-1{{actor-isolated subscript 'subscript(_:)' cannot be used to satisfy nonisolated requirement from protocol 'SyncProtocol'}}
   // expected-note@-2{{add 'nonisolated' to 'subscript(_:)' to make this subscript not isolated to the actor}}{{3-3=nonisolated }}
 
   // Static methods and properties are okay.