Change note for non marked with main actor global variables

include/swift/AST/DiagnosticsSema.def

@@ -5393,7 +5393,7 @@ NOTE(note_add_distributed_to_decl,none,
 ERROR(invalid_isolated_calls_in_body,none,
      "calls to '@%0'-isolated' code in %kind1",
      (StringRef, const ValueDecl *))
-NOTE(add_globalactor_to_function,none,
+NOTE(add_globalactor_to_decl,none,
      "add '@%0' to make %kind1 part of global actor %2",
      (StringRef, const ValueDecl *, Type))
 FIXIT(insert_globalactor_attr, "@%0 ", (Type))
@@ -5645,8 +5645,6 @@ ERROR(shared_immutable_state_decl,none,
 NOTE(shared_state_make_immutable,none,
      "convert %0 to a 'let' constant to make 'Sendable' shared state immutable",
      (const ValueDecl *))
-NOTE(shared_state_main_actor_node,none,
-     "annotate %0 with '@MainActor' if property should only be accessed from the main actor", (const ValueDecl *))
 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,

lib/Sema/TypeCheckConcurrency.cpp

@@ -2436,7 +2436,7 @@ namespace {
             if (fn->getOverriddenDecl())
               return false;
 
-            fn->diagnose(diag::add_globalactor_to_function,
+            fn->diagnose(diag::add_globalactor_to_decl,
                          globalActor->getWithoutParens().getString(),
                          fn, globalActor)
                 .fixItInsert(fn->getAttributeInsertionLoc(false),
@@ -5403,7 +5403,7 @@ ActorIsolation ActorIsolationRequest::evaluate(
 
   // Diagnose global state that is not either immutable plus Sendable or
   // isolated to a global actor.
-  auto checkGlobalIsolation = [var = dyn_cast<VarDecl>(value)](
+  auto checkGlobalIsolation = [var = dyn_cast<VarDecl>(value), &ctx](
                                   ActorIsolation isolation) {
     // Diagnose only declarations in the same module.
     //
@@ -5447,10 +5447,14 @@ ActorIsolation ActorIsolationRequest::evaluate(
             }
           }
 
-          diagVar->diagnose(diag::shared_state_main_actor_node,
-                            diagVar)
-              .fixItInsert(diagVar->getAttributeInsertionLoc(false),
-                           "@MainActor ");
+          auto mainActor = ctx.getMainActorType();
+          if (mainActor) {
+            diagVar->diagnose(diag::add_globalactor_to_decl,
+                              mainActor->getWithoutParens().getString(),
+                              diagVar, mainActor)
+                .fixItInsert(diagVar->getAttributeInsertionLoc(false),
+                             diag::insert_globalactor_attr, mainActor);
+          }
           diagVar->diagnose(diag::shared_state_nonisolated_unsafe,
                             diagVar)
               .fixItInsert(diagVar->getAttributeInsertionLoc(true),

test/Concurrency/Inputs/sendable_cycle_other.swift

@@ -1,5 +1,5 @@
 struct Foo {
   static let member = Bar() // expected-complete-warning {{static property 'member' is not concurrency-safe because non-'Sendable' type 'Bar' may have shared mutable state; this is an error in the Swift 6 language mode}}
-  // expected-complete-note@-1 {{annotate 'member' with '@MainActor' if property should only be accessed from the main actor}}
+  // expected-complete-note@-1 {{add '@MainActor' to make static property 'member' part of global actor 'MainActor'}}
   // expected-complete-note@-2{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
 }

test/Concurrency/concurrency_warnings.swift

@@ -13,7 +13,7 @@ class GlobalCounter { // expected-note{{class 'GlobalCounter' does not conform t
 
 let rs = GlobalCounter() // expected-warning {{let 'rs' is not concurrency-safe because non-'Sendable' type 'GlobalCounter' may have shared mutable state; this is an error in the Swift 6 language mode}}
 // expected-note@-1 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
-// expected-note@-2 {{annotate 'rs' with '@MainActor' if property should only be accessed from the main actor}}
+// expected-note@-2 {{add '@MainActor' to make let 'rs' part of global actor 'MainActor'}}
 
 import GlobalVariables
 

test/Concurrency/concurrent_value_checking.swift

@@ -295,7 +295,7 @@ typealias BadGenericCF<T> = @Sendable () -> T?
 typealias GoodGenericCF<T: Sendable> = @Sendable () -> T? // okay
 
 var concurrentFuncVar: (@Sendable (NotConcurrent) -> Void)? = nil // expected-warning{{var 'concurrentFuncVar' is not concurrency-safe because it is nonisolated global shared mutable state; this is an error in the Swift 6 language mode}}
-// expected-note@-1 {{annotate 'concurrentFuncVar' with '@MainActor' if property should only be accessed from the main actor}}
+// expected-note@-1 {{add '@MainActor' to make var 'concurrentFuncVar' part of global actor 'MainActor'}}
 // expected-note@-2 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
 // expected-note@-3 {{convert 'concurrentFuncVar' to a 'let' constant to make 'Sendable' shared state immutable}}
 

test/Concurrency/flow_isolation.swift

@@ -520,7 +520,7 @@ struct CardboardBox<T> {
 
 @available(SwiftStdlib 5.1, *)
 var globalVar: EscapeArtist? // expected-warning {{var 'globalVar' is not concurrency-safe because it is nonisolated global shared mutable state; this is an error in the Swift 6 language mode}}
-// expected-note@-1 {{annotate 'globalVar' with '@MainActor' if property should only be accessed from the main actor}}
+// expected-note@-1 {{add '@MainActor' to make var 'globalVar' part of global actor 'MainActor'}}
 // expected-note@-2 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
 // expected-note@-3 {{convert 'globalVar' to a 'let' constant to make 'Sendable' shared state immutable}}
 

test/Concurrency/freestanding_top_level.swift

@@ -2,7 +2,7 @@
 // RUN: %target-swift-frontend -concurrency-model=task-to-thread -typecheck  -verify -verify-additional-prefix complete- -strict-concurrency=complete %s
 
 // expected-complete-warning@+4 {{var 'global' is not concurrency-safe because it is nonisolated global shared mutable state; this is an error in the Swift 6 language mode}}
-// expected-complete-note@+3 {{annotate 'global' with '@MainActor' if property should only be accessed from the main actor}}{{1-1=@MainActor }}
+// expected-complete-note@+3 {{add '@MainActor' to make var 'global' part of global actor 'MainActor'}}{{1-1=@MainActor }}
 // expected-complete-note@+2 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}{{1-1=nonisolated(unsafe) }}
 // expected-complete-note@+1 {{convert 'global' to a 'let' constant to make 'Sendable' shared state immutable}}{{1-4=let}}
 var global = 10

test/Concurrency/global_variables.swift

@@ -15,7 +15,7 @@ actor TestGlobalActor {
 var mutableIsolatedGlobal = 1
 
 var mutableNonisolatedGlobal = 1 // expected-error{{var 'mutableNonisolatedGlobal' is not concurrency-safe because it is nonisolated global shared mutable state}}
-// expected-note@-1{{annotate 'mutableNonisolatedGlobal' with '@MainActor' if property should only be accessed from the main actor}}{{1-1=@MainActor }}
+// expected-note@-1{{add '@MainActor' to make var 'mutableNonisolatedGlobal' part of global actor 'MainActor'}}{{1-1=@MainActor }}
 // expected-note@-2{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}{{1-1=nonisolated(unsafe) }}
 // expected-note@-3{{convert 'mutableNonisolatedGlobal' to a 'let' constant to make 'Sendable' shared state immutable}}{{1-4=let}}
 
@@ -48,25 +48,25 @@ actor TestActor {
 struct TestStatics {
   static let immutableExplicitSendable = TestSendable()
   static let immutableNonsendable = TestNonsendable() // expected-error{{static property 'immutableNonsendable' is not concurrency-safe because non-'Sendable' type 'TestNonsendable' may have shared mutable state}}
-  // expected-note@-1 {{annotate 'immutableNonsendable' with '@MainActor' if property should only be accessed from the main actor}}
+  // expected-note@-1 {{add '@MainActor' to make static property 'immutableNonsendable' part of global actor 'MainActor'}}
   // expected-note@-2 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
   static nonisolated(unsafe) let immutableNonisolatedUnsafe = TestNonsendable()
   static nonisolated let immutableNonisolated = TestNonsendable() // expected-error{{static property 'immutableNonisolated' is not concurrency-safe because non-'Sendable' type 'TestNonsendable' may have shared mutable state}}
   // expected-note@-1 {{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
   // expected-error@-2 {{'nonisolated' can not be applied to variable with non-'Sendable' type 'TestNonsendable'}}
-  // expected-note@-3{{annotate 'immutableNonisolated' with '@MainActor' if property should only be accessed from the main actor}}
+  // expected-note@-3{{add '@MainActor' to make static property 'immutableNonisolated' part of global actor 'MainActor'}}
   static nonisolated(unsafe) let immutableNonisolatedUnsafeSendable = TestSendable()
   // expected-warning@-1 {{'nonisolated(unsafe)' is unnecessary for a constant with 'Sendable' type 'TestSendable', consider removing it}} {{10-30=}}
   static let immutableInferredSendable = 0
   static var mutable = 0 // expected-error{{static property 'mutable' is not concurrency-safe because it is nonisolated global shared mutable state}}
   // expected-note@-1{{convert 'mutable' to a 'let' constant to make 'Sendable' shared state immutable}}
   // expected-note@-2{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
-  // expected-note@-3{{annotate 'mutable' with '@MainActor' if property should only be accessed from the main actor}}
+  // expected-note@-3{{add '@MainActor' to make static property 'mutable' part of global actor 'MainActor'}}
   static var computedProperty: Int { 0 } // computed property that, though static, has no storage so is not a global
   @TestWrapper static var wrapped: Int // expected-error{{static property 'wrapped' is not concurrency-safe because it is nonisolated global shared mutable state}}
   // expected-note@-1{{convert 'wrapped' to a 'let' constant to make 'Sendable' shared state immutable}}{{23-26=let}}
   // expected-note@-2{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}{{16-16=nonisolated(unsafe) }}
-  // expected-note@-3{{annotate 'wrapped' with '@MainActor' if property should only be accessed from the main actor}}{{3-3=@MainActor }}
+  // expected-note@-3{{add '@MainActor' to make static property 'wrapped' part of global actor 'MainActor'}}{{3-3=@MainActor }}
 }
 
 public actor TestPublicActor {

test/Concurrency/predates_concurrency_import.swift

@@ -44,7 +44,7 @@ let nonStrictGlobal = NonStrictClass() // no warning
 
 let strictGlobal = StrictStruct() // expected-warning{{let 'strictGlobal' is not concurrency-safe because non-'Sendable' type 'StrictStruct' may have shared mutable state}}
 // expected-note@-1{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
-// expected-note@-2{{annotate 'strictGlobal' with '@MainActor' if property should only be accessed from the main actor}}
+// expected-note@-2{{add '@MainActor' to make let 'strictGlobal' part of global actor 'MainActor'}}
 
 extension NonStrictClass {
   @Sendable func f() { }
@@ -62,7 +62,7 @@ struct HasStatics {
   // expected-warning@-1{{'nonisolated' can not be applied to variable with non-'Sendable' type 'StrictStruct'}}
   // expected-warning@-2{{static property 'ss' is not concurrency-safe because non-'Sendable' type 'StrictStruct' may have shared mutable state}}
   // expected-note@-3{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
-  // expected-note@-4{{annotate 'ss' with '@MainActor' if property should only be accessed from the main actor}}
+  // expected-note@-4{{add '@MainActor' to make static property 'ss' part of global actor 'MainActor'}}
 }
 
 extension NonStrictClass2: @retroactive MySendableProto { }

test/Concurrency/predates_concurrency_import_swift6.swift

@@ -18,7 +18,7 @@ func test(ss: StrictStruct, ns: NonStrictClass) {
 
 let nonStrictGlobal = NonStrictClass()
 let strictGlobal = StrictStruct() // expected-warning{{let 'strictGlobal' is not concurrency-safe because non-'Sendable' type 'StrictStruct' may have shared mutable state}}
-// expected-note@-1{{annotate 'strictGlobal' with '@MainActor' if property should only be accessed from the main actor}}
+// expected-note@-1{{add '@MainActor' to make let 'strictGlobal' part of global actor 'MainActor'}}
 // expected-note@-2{{disable concurrency-safety checks if accesses are protected by an external synchronization mechanism}}
 
 extension NonStrictClass {