Merge pull request swiftlang#68961 from hborla/imported-as-preconcurrency

[Concurrency] Try harder to downgrade preconcurrency errors to warnings in Swift 5 mode.

Author: hborla

lib/Sema/TypeCheckConcurrency.cpp

@@ -2932,12 +2932,14 @@ namespace {
       // we're in an asynchronous context.
       if (requiresAsync && !getDeclContext()->isAsyncContext()) {
         if (calleeDecl) {
+          auto preconcurrency = getContextIsolation().preconcurrency() ||
+              calleeDecl->preconcurrency();
           ctx.Diags.diagnose(
               apply->getLoc(), diag::actor_isolated_call_decl,
               *unsatisfiedIsolation,
               calleeDecl,
               getContextIsolation())
-            .warnUntilSwiftVersionIf(getContextIsolation().preconcurrency(), 6);
+            .warnUntilSwiftVersionIf(preconcurrency, 6);
           calleeDecl->diagnose(diag::actor_isolated_sync_func, calleeDecl);
         } else {
           ctx.Diags.diagnose(
@@ -3573,7 +3575,8 @@ getIsolationFromAttributes(const Decl *decl, bool shouldDiagnose = true,
       isUnsafe = true;
 
     return ActorIsolation::forGlobalActor(
-        globalActorType->mapTypeOutOfContext(), isUnsafe);
+        globalActorType->mapTypeOutOfContext(), isUnsafe)
+        .withPreconcurrency(decl->preconcurrency());
   }
 
   llvm_unreachable("Forgot about an attribute?");
@@ -5460,7 +5463,8 @@ static ActorIsolation getActorIsolationForReference(
               return closure->isIsolatedByPreconcurrency();
             })) {
       declIsolation = ActorIsolation::forGlobalActor(
-          declIsolation.getGlobalActor(), /*unsafe=*/false);
+          declIsolation.getGlobalActor(), /*unsafe=*/false)
+          .withPreconcurrency(declIsolation.preconcurrency());
     } else {
       declIsolation = ActorIsolation::forUnspecified();
     }
@@ -5727,7 +5731,7 @@ ActorReferenceResult ActorReferenceResult::forReference(
   Options options = llvm::None;
 
   // Note if the reference originates from a @preconcurrency-isolated context.
-  if (contextIsolation.preconcurrency())
+  if (contextIsolation.preconcurrency() || declIsolation.preconcurrency())
     options |= Flags::Preconcurrency;
 
   // If the declaration isn't asynchronous, promote to async.

test/ClangImporter/objc_async.swift

@@ -210,7 +210,7 @@ class MyButton : NXButton {
   }
 
   @SomeGlobalActor func testOther() {
-    onButtonPress() // expected-error{{call to main actor-isolated instance method 'onButtonPress()' in a synchronous global actor 'SomeGlobalActor'-isolated context}}
+    onButtonPress() // expected-warning{{call to main actor-isolated instance method 'onButtonPress()' in a synchronous global actor 'SomeGlobalActor'-isolated context}}
   }
 
   func test() {

test/ClangImporter/objc_isolation_complete.swift

@@ -0,0 +1,17 @@
+// RUN: %target-swift-frontend(mock-sdk: %clang-importer-sdk) -typecheck -I %S/Inputs/custom-modules %s -verify -strict-concurrency=complete -parse-as-library
+
+// REQUIRES: objc_interop
+// REQUIRES: concurrency
+// REQUIRES: asserts
+
+import Foundation
+import ObjCConcurrency
+
+// expected-note@+1 2{{add '@MainActor' to make global function 'unsatisfiedPreconcurrencyIsolation(view:)' part of global actor 'MainActor'}}
+func unsatisfiedPreconcurrencyIsolation(view: MyView) {
+  // expected-warning@+1 {{call to main actor-isolated instance method 'display()' in a synchronous nonisolated context}}
+  view.display()
+
+  // expected-warning@+1 {{main actor-isolated property 'isVisible' can not be referenced from a non-isolated context}}
+  _ = view.isVisible
+}

test/Concurrency/preconcurrency_typealias.swift

@@ -20,11 +20,11 @@ struct Outer {
 
 func test() {
   var _: Outer.FN = {
-    f() // expected-complete-sns-error {{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
+    f() // expected-complete-sns-warning {{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
   }
 
   var _: FN = {
-    f() // expected-complete-sns-error {{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
+    f() // expected-complete-sns-warning {{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
     print("Hello")
   }
 
@@ -39,11 +39,11 @@ func test() {
 @available(SwiftStdlib 5.1, *)
 func testAsync() async {
   var _: Outer.FN = {
-    f() // expected-error{{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
+    f() // expected-warning{{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
   }
 
   var _: FN = {
-    f() // expected-error{{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
+    f() // expected-warning{{call to main actor-isolated global function 'f()' in a synchronous nonisolated context}}
     print("Hello")
   }
 

test/Concurrency/predates_concurrency.swift

@@ -97,7 +97,7 @@ func testCalls(x: X) {
     })
 
   onMainActorAlways() // okay with minimal/targeted concurrency. Not ok with complete.
-  // expected-complete-sns-error @-1 {{call to main actor-isolated global function 'onMainActorAlways()' in a synchronous nonisolated context}}
+  // expected-complete-sns-warning @-1 {{call to main actor-isolated global function 'onMainActorAlways()' in a synchronous nonisolated context}}
 
   // Ok with minimal/targeted concurrency, Not ok with complete.
   let _: () -> Void = onMainActorAlways // expected-complete-sns-warning {{converting function value of type '@MainActor () -> ()' to '() -> Void' loses global actor 'MainActor'}}

test/Inputs/clang-importer-sdk/usr/include/ObjCConcurrency.h

@@ -327,4 +327,10 @@ UI_ACTOR
 - (void)icedMochaService:(NSObject *)mochaService generateMochaWithCompletion:(void (^)(NSObject *_Nullable ingredient1, NSObject *ingredient2, NSObject *ingredient3))completionHandler;
 @end
 
+MAIN_ACTOR
+@interface MyView : NSObject
+- (void)display;
+@property(readonly) BOOL isVisible;
+@end
+
 #pragma clang assume_nonnull end