[Concurrency] Split up the non-Sendable diagnostics and improve wording.

include/swift/AST/DiagnosticsSema.def

@@ -5635,36 +5635,73 @@ NOTE(in_derived_conformance, none,
 NOTE(in_derived_witness, none,
      "in %0 %1 for derived conformance to %2",
      (DescriptiveDeclKind, DeclName, Type))
-ERROR(non_sendable_param_type,none,
-      "non-sendable type %0 %select{passed in call to %3 %kind2|"
-      "exiting %3 context in call to nonisolated %kind2|"
-      "passed in implicitly asynchronous call to %3 %kind2|"
-      "in parameter of the protocol requirement satisfied by %3 %kind2|"
-      "in parameter of superclass method overridden by %3 %kind2|"
-      "in parameter of %3 '@objc' %kind2}1 cannot cross actor boundary",
-      (Type, unsigned, const ValueDecl *, ActorIsolation))
-ERROR(non_sendable_result_type,none,
-      "non-sendable type %0 returned by %select{call to %3 %kind2|"
-      "call from %4 context to nonisolated %kind2|"
-      "implicitly asynchronous call to %3 %kind2|"
-      "%3 %kind2 satisfying protocol requirement|"
-      "%3 overriding %kind2|"
-      "%3 '@objc' %kind2}1 cannot cross actor boundary",
-      (Type, unsigned, const ValueDecl *, ActorIsolation))
+
+ERROR(non_sendable_arg_into_actor,none,
+      "non-sendable type %0 cannot be sent into %2 context in call to %kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_arg_exits_actor,none,
+      "non-sendable type %0 cannot exit %2 context in call to nonisolated "
+      "%kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_param_in_witness,none,
+      "non-sendable parameter type %0 cannot be sent from caller of "
+      "protocol requirement %1 into %2 implementation",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_param_in_override,none,
+      "non-sendable parameter type %0 cannot be sent from caller of "
+      "superclass %kind1 into %2 override",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_param_in_objc,none,
+      "non-sendable parameter type %0 of %2 '@objc' %kind1 cannot cross actor "
+      "boundary",
+      (Type, const ValueDecl *, ActorIsolation))
+
+ERROR(non_sendable_result_into_actor,none,
+      "non-sendable result type %0 cannot be sent from %2 context in call "
+      "to %kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_result_exits_actor,none,
+      "non-sendable result type %0 cannot exit %2 context in call to "
+      "nonisolated %kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_result_in_witness,none,
+      "non-sendable type %0 cannot be returned from %2 implementation "
+      "to caller of protocol requirement %1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_result_in_override,none,
+      "non-sendable type %0 cannot be returned from %2 override to "
+      "caller of superclass %kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_result_in_objc,none,
+      "non-sendable type %0 returned by %2 '@objc' %kind1 cannot cross "
+      "actor boundary",
+      (Type, const ValueDecl *, ActorIsolation))
+
 ERROR(non_sendable_call_result_type,none,
-      "non-sendable type %0 returned by %select{|implicitly async }1"
-      "call to %2 function cannot cross actor boundary",
-      (Type, bool, ActorIsolation))
-ERROR(non_sendable_property_type,none,
-      "non-sendable type %0 in %select{"
-      "%select{asynchronous access to %4 %kind1|"
-      "asynchronous access from %4 context to nonisolated %kind1|"
-      "implicitly asynchronous access to %4 %kind1|"
-      "conformance of %4 %kind1 to protocol requirement|"
-      "%4 overriding %kind1|"
-      "%4 '@objc' %kind1}3|captured local %1}2 cannot "
-      "cross %select{actor|task}2 boundary",
-      (Type, const ValueDecl *, bool, unsigned, ActorIsolation))
+      "non-sendable result type %0 cannot be sent from %1 context in call "
+      "to async function",
+      (Type, ActorIsolation))
+
+ERROR(non_sendable_property_exits_actor,none,
+      "non-sendable type %0 of %kind1 cannot exit %2 context",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_property_into_actor,none,
+      "non-sendable type %0 of nonisolated %kind1 cannot be sent to "
+      "%2 context",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_property_in_witness,none,
+      "non-sendable type %0 cannot be returned from %2 implementation "
+      "to caller of protocol requirement %1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_property_in_override,none,
+      "non-sendable type %0 cannot be returned from %2 override to "
+      "caller of superclass %kind1",
+      (Type, const ValueDecl *, ActorIsolation))
+ERROR(non_sendable_property_in_objc,none,
+      "non-sendable type %0 returned by %2 '@objc' %kind1 cannot cross "
+      "actor boundary",
+      (Type, const ValueDecl *, ActorIsolation))
+
 ERROR(non_sendable_keypath_capture,none,
       "cannot form key path that captures non-sendable type %0",
       (Type))

lib/Sema/TypeCheckConcurrency.cpp

@@ -1121,6 +1121,72 @@ bool swift::diagnoseNonSendableTypes(
   return anyMissing;
 }
 
+static
+Diag<Type, const ValueDecl *, ActorIsolation>
+getSendableParamDiag(SendableCheckReason refKind) {
+  switch (refKind) {
+  case SendableCheckReason::CrossActor:
+  case SendableCheckReason::SynchronousAsAsync:
+    return diag::non_sendable_arg_into_actor;
+
+  case SendableCheckReason::ExitingActor:
+    return diag::non_sendable_arg_exits_actor;
+
+  case SendableCheckReason::Conformance:
+    return diag::non_sendable_param_in_witness;
+
+  case SendableCheckReason::Override:
+    return diag::non_sendable_param_in_override;
+
+  case SendableCheckReason::ObjC:
+    return diag::non_sendable_param_in_objc;
+  }
+}
+
+static
+Diag<Type, const ValueDecl *, ActorIsolation>
+getSendableResultDiag(SendableCheckReason refKind) {
+  switch (refKind) {
+  case SendableCheckReason::CrossActor:
+  case SendableCheckReason::SynchronousAsAsync:
+    return diag::non_sendable_result_into_actor;
+
+  case SendableCheckReason::ExitingActor:
+    return diag::non_sendable_result_exits_actor;
+
+  case SendableCheckReason::Conformance:
+    return diag::non_sendable_result_in_witness;
+
+  case SendableCheckReason::Override:
+    return diag::non_sendable_result_in_override;
+
+  case SendableCheckReason::ObjC:
+    return diag::non_sendable_result_in_objc;
+  }
+}
+
+static
+Diag<Type, const ValueDecl *, ActorIsolation>
+getSendablePropertyDiag(SendableCheckReason refKind) {
+  switch (refKind) {
+  case SendableCheckReason::CrossActor:
+  case SendableCheckReason::SynchronousAsAsync:
+    return diag::non_sendable_property_exits_actor;
+
+  case SendableCheckReason::ExitingActor:
+    return diag::non_sendable_property_into_actor;
+
+  case SendableCheckReason::Conformance:
+    return diag::non_sendable_property_in_witness;
+
+  case SendableCheckReason::Override:
+    return diag::non_sendable_property_in_override;
+
+  case SendableCheckReason::ObjC:
+    return diag::non_sendable_property_in_objc;
+  }
+}
+
 bool swift::diagnoseNonSendableTypesInReference(
     Expr *base, ConcreteDeclRef declRef, const DeclContext *fromDC,
     SourceLoc refLoc, SendableCheckReason refKind,
@@ -1155,8 +1221,8 @@ bool swift::diagnoseNonSendableTypesInReference(
             base->getType(),
             fromDC, derivedConformanceType,
             base->getStartLoc(),
-            diag::non_sendable_param_type,
-            (unsigned)refKind, declRef.getDecl(),
+            getSendableParamDiag(refKind),
+            declRef.getDecl(),
             getActorIsolation()))
       return true;
   }
@@ -1171,8 +1237,8 @@ bool swift::diagnoseNonSendableTypesInReference(
         if (diagnoseNonSendableTypes(
                 paramType, fromDC, derivedConformanceType,
                 refLoc, diagnoseLoc.isInvalid() ? refLoc : diagnoseLoc,
-                diag::non_sendable_param_type,
-            (unsigned)refKind, function, getActorIsolation()))
+                getSendableParamDiag(refKind),
+                function, getActorIsolation()))
           return true;
       }
     }
@@ -1185,8 +1251,8 @@ bool swift::diagnoseNonSendableTypesInReference(
         if (diagnoseNonSendableTypes(
             resultType, fromDC, derivedConformanceType,
             refLoc, diagnoseLoc.isInvalid() ? refLoc : diagnoseLoc,
-                diag::non_sendable_result_type,
-            (unsigned)refKind, func, getActorIsolation()))
+            getSendableResultDiag(refKind),
+            func, getActorIsolation()))
           return true;
       }
     }
@@ -1201,11 +1267,8 @@ bool swift::diagnoseNonSendableTypesInReference(
     if (diagnoseNonSendableTypes(
             propertyType, fromDC,
             derivedConformanceType, refLoc,
-            diag::non_sendable_property_type,
-            var,
-            var->isLocalCapture(),
-            (unsigned)refKind,
-            getActorIsolation()))
+            getSendablePropertyDiag(refKind),
+            var, getActorIsolation()))
       return true;
   }
 
@@ -1217,8 +1280,8 @@ bool swift::diagnoseNonSendableTypesInReference(
         if (diagnoseNonSendableTypes(
                 paramType, fromDC, derivedConformanceType,
                 refLoc, diagnoseLoc.isInvalid() ? refLoc : diagnoseLoc,
-                diag::non_sendable_param_type,
-                (unsigned)refKind, subscript, getActorIsolation()))
+                getSendableParamDiag(refKind),
+                subscript, getActorIsolation()))
           return true;
       }
     }
@@ -1229,8 +1292,8 @@ bool swift::diagnoseNonSendableTypesInReference(
       if (diagnoseNonSendableTypes(
               resultType, fromDC, derivedConformanceType,
               refLoc, diagnoseLoc.isInvalid() ? refLoc : diagnoseLoc,
-              diag::non_sendable_result_type,
-          (unsigned)refKind, subscript, getActorIsolation()))
+              getSendableResultDiag(refKind),
+              subscript, getActorIsolation()))
         return true;
     }
 
@@ -3849,14 +3912,21 @@ namespace {
                  fnType->getResult().getPointer();
         };
 
-        if (!willDoubleError() &&
-            diagnoseNonSendableTypes(fnType->getResult(), getDeclContext(),
-                                     /*inDerivedConformance*/ Type(),
-                                     apply->getLoc(),
-                                     diag::non_sendable_call_result_type,
-                                     apply->isImplicitlyAsync().has_value(),
-                                     *unsatisfiedIsolation)) {
-          return true;
+        if (!willDoubleError()) {
+          if (calleeDecl) {
+            return diagnoseNonSendableTypes(fnType->getResult(), getDeclContext(),
+                /*inDerivedConformance*/ Type(),
+                apply->getLoc(),
+                diag::non_sendable_result_into_actor,
+                calleeDecl,
+                *unsatisfiedIsolation);
+          }
+
+          return diagnoseNonSendableTypes(fnType->getResult(), getDeclContext(),
+              /*inDerivedConformance*/ Type(),
+              apply->getLoc(),
+              diag::non_sendable_call_result_type,
+              *unsatisfiedIsolation);
         }
       }
 

test/ClangImporter/objc_async.swift

@@ -322,12 +322,12 @@ func check() async {
   _ = await BarFrame()
   _ = await FooFrame()
   _ = await BazFrame()
-  // expected-warning@-1 {{non-sendable type 'BazFrame' returned by implicitly async call to global actor 'SomeGlobalActor'-isolated function cannot cross actor boundary; this is an error in the Swift 6 language mode}}
+  // expected-warning@-1 {{non-sendable result type 'BazFrame' cannot be sent from global actor 'SomeGlobalActor'-isolated context in call to initializer 'init()'; this is an error in the Swift 6 language mode}}
 
   _ = await BarFrame(size: 0)
   _ = await FooFrame(size: 0)
   _ = await BazFrame(size: 0)
-  // expected-warning@-1 {{non-sendable type 'BazFrame' returned by implicitly async call to global actor 'SomeGlobalActor'-isolated function cannot cross actor boundary; this is an error in the Swift 6 language mode}}
+  // expected-warning@-1 {{non-sendable result type 'BazFrame' cannot be sent from global actor 'SomeGlobalActor'-isolated context in call to initializer 'init(size:)'; this is an error in the Swift 6 language mode}}
 }
 
 @available(SwiftStdlib 5.5, *)

test/Concurrency/actor_call_implicitly_async.swift

@@ -176,11 +176,11 @@ func someAsyncFunc() async {
   ////////////
   // effectful properties from outside the actor instance
 
-  // expected-warning@+2 {{non-sendable type 'Box' in asynchronous access to actor-isolated property 'effPropA' cannot cross actor boundary}}
+  // expected-warning@+2 {{non-sendable type 'Box' of property 'effPropA' cannot exit actor-isolated context}}
   // expected-error@+1{{expression is 'async' but is not marked with 'await'}} {{7-7=await }} expected-note@+1{{property access is 'async'}}
   _ = a.effPropA
 
-  // expected-warning@+3 {{non-sendable type 'Box' in implicitly asynchronous access to actor-isolated property 'effPropT' cannot cross actor boundary}}
+  // expected-warning@+3 {{non-sendable type 'Box' of property 'effPropT' cannot exit actor-isolated context}}
   // expected-error@+2{{property access can throw, but it is not marked with 'try' and the error is not handled}}
   // expected-error@+1{{expression is 'async' but is not marked with 'await'}} {{7-7=await }} expected-note@+1{{property access is 'async'}}
   _ = a.effPropT
@@ -190,8 +190,8 @@ func someAsyncFunc() async {
   _ = a.effPropAT
 
   // (mostly) corrected ones
-  _ = await a.effPropA  // expected-warning {{non-sendable type 'Box' in asynchronous access to actor-isolated property 'effPropA' cannot cross actor boundary}}
-  _ = try! await a.effPropT // expected-warning {{non-sendable type 'Box' in implicitly asynchronous access to actor-isolated property 'effPropT' cannot cross actor boundary}}
+  _ = await a.effPropA  // expected-warning {{non-sendable type 'Box' of property 'effPropA' cannot exit actor-isolated context}}
+  _ = try! await a.effPropT // expected-warning {{non-sendable type 'Box' of property 'effPropT' cannot exit actor-isolated context}}
   _ = try? await a.effPropAT
 
   print("ok!")
@@ -353,23 +353,23 @@ actor Calculator {
 
 @OrangeActor func doSomething() async {
   let _ = (await bananaAdd(1))(2)
-  // expected-warning@-1{{non-sendable type '(Int) -> Int' returned by implicitly async call to global actor 'BananaActor'-isolated function cannot cross actor boundary}}
+  // expected-warning@-1{{non-sendable result type '(Int) -> Int' cannot be sent from global actor 'BananaActor'-isolated context in call to global function 'bananaAdd'}}
   // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
   let _ = await (await bananaAdd(1))(2) // expected-warning{{no 'async' operations occur within 'await' expression}}
-  // expected-warning@-1{{non-sendable type '(Int) -> Int' returned by implicitly async call to global actor 'BananaActor'-isolated function cannot cross actor boundary}}
+  // expected-warning@-1{{non-sendable result type '(Int) -> Int' cannot be sent from global actor 'BananaActor'-isolated context in call to global function 'bananaAdd'}}
   // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
 
   let calc = Calculator()
 
   let _ = (await calc.addCurried(1))(2)
-  // expected-warning@-1{{non-sendable type '(Int) -> Int' returned by implicitly async call to actor-isolated function cannot cross actor boundary}}
+  // expected-warning@-1{{non-sendable result type '(Int) -> Int' cannot be sent from actor-isolated context in call to instance method 'addCurried'}}
   // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
   let _ = await (await calc.addCurried(1))(2) // expected-warning{{no 'async' operations occur within 'await' expression}}
-  // expected-warning@-1{{non-sendable type '(Int) -> Int' returned by implicitly async call to actor-isolated function cannot cross actor boundary}}
+  // expected-warning@-1{{non-sendable result type '(Int) -> Int' cannot be sent from actor-isolated context in call to instance method 'addCurried'}}
   // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
 
   let plusOne = await calc.addCurried(await calc.add(0, 1))
-  // expected-warning@-1{{non-sendable type '(Int) -> Int' returned by implicitly async call to actor-isolated function cannot cross actor boundary}}
+  // expected-warning@-1{{non-sendable result type '(Int) -> Int' cannot be sent from actor-isolated context in call to instance method 'addCurried'}}
   // expected-note@-2{{a function type must be marked '@Sendable' to conform to 'Sendable'}}
   let _ = plusOne(2)
 }

test/Concurrency/actor_inout_isolation.swift

@@ -119,7 +119,7 @@ extension TestActor {
   func passStateIntoDifferentClassMethod() async {
     let other = NonAsyncClass()
     let otherCurry = other.modifyOtherAsync
-    // expected-targeted-complete-tns-warning @-1 {{non-sendable type 'NonAsyncClass' exiting actor-isolated context in call to nonisolated instance method 'modifyOtherAsync' cannot cross actor boundary}}
+    // expected-targeted-complete-tns-warning @-1 {{non-sendable type 'NonAsyncClass' cannot exit actor-isolated context in call to nonisolated instance method 'modifyOtherAsync'}}
     await other.modifyOtherAsync(&value2)
     // expected-error @-1 {{actor-isolated property 'value2' cannot be passed 'inout' to 'async' function call}}
 
@@ -288,11 +288,11 @@ actor ProtectArray {
   func test() async {
     // FIXME: this is invalid too!
     _ = await array.mutateAsynchronously
-    // expected-targeted-complete-tns-warning@-1 {{non-sendable type '@lvalue [Int]' exiting actor-isolated context in call to nonisolated property 'mutateAsynchronously' cannot cross actor boundary}}
+    // expected-targeted-complete-tns-warning@-1 {{non-sendable type '@lvalue [Int]' cannot exit actor-isolated context in call to nonisolated property 'mutateAsynchronously'}}
 
     _ = await array[mutateAsynchronously: 0]
     // expected-error@-1 {{actor-isolated property 'array' cannot be passed 'inout' to 'async' function call}}
-    // expected-targeted-complete-tns-warning@-2 {{non-sendable type 'inout Array<Int>' exiting actor-isolated context in call to nonisolated subscript 'subscript(mutateAsynchronously:)' cannot cross actor boundary}}
+    // expected-targeted-complete-tns-warning@-2 {{non-sendable type 'inout Array<Int>' cannot exit actor-isolated context in call to nonisolated subscript 'subscript(mutateAsynchronously:)'}}
 
     await passToAsync(array[0])