[region-isolation] When emitting an error for an isolated closure use of a never transferrable value, use the dynamic isolation. Do not assume it is task isolated.

rdar://125372336

Author: gottesmm

lib/SILOptimizer/Mandatory/TransferNonSendable.cpp

@@ -1023,8 +1023,13 @@ class TransferNonTransferrableDiagnosticEmitter {
 
   void emitFunctionArgumentClosure(SourceLoc loc, Type type,
                                    ApplyIsolationCrossing crossing) {
+    SmallString<64> descriptiveKindStr;
+    {
+      llvm::raw_svector_ostream os(descriptiveKindStr);
+      getIsolationRegionInfo().printForDiagnostics(os);
+    }
     diagnoseError(loc, diag::regionbasedisolation_arg_transferred,
-                  "task-isolated", type, crossing.getCalleeIsolation())
+                  descriptiveKindStr, type, crossing.getCalleeIsolation())
         .highlight(getOperand()->getUser()->getLoc().getSourceRange());
   }
 

test/Concurrency/transfernonsendable_global_actor.swift

@@ -8,7 +8,7 @@
 // MARK: Declarations //
 ////////////////////////
 
-class NonSendableKlass {}
+class NonSendableKlass {} // expected-complete-note {{}}
 final class SendableKlass : Sendable {}
 
 actor CustomActorInstance {}
@@ -24,6 +24,8 @@ func transferToNonIsolated<T>(_ t: T) async {}
 func useValue<T>(_ t: T) {}
 
 var booleanFlag: Bool { false }
+@MainActor var mainActorIsolatedGlobal = NonSendableKlass()
+@CustomActor var customActorIsolatedGlobal = NonSendableKlass()
 
 /////////////////
 // MARK: Tests //
@@ -170,3 +172,25 @@ struct Clock {
     try! await c.sleep()
   }
 }
+
+@CustomActor func testGlobalAndGlobalIsolatedPartialApplyMismatch() {
+  let ns = customActorIsolatedGlobal
+
+  let _ = { @MainActor in
+    print(ns) // expected-tns-warning {{global actor 'CustomActor'-isolated value of type 'NonSendableKlass' transferred to main actor-isolated context}}
+    // expected-complete-warning @-1 {{capture of 'ns' with non-sendable type 'NonSendableKlass' in an isolated closure}}
+  }
+
+  useValue(ns)
+}
+
+@MainActor func testGlobalAndGlobalIsolatedPartialApplyMatch() {
+  let ns = mainActorIsolatedGlobal
+
+  // TODO: We should not consider this to be a transfer.
+  let _ = { @MainActor in
+    print(ns) // expected-tns-warning {{main actor-isolated value of type 'NonSendableKlass' transferred to main actor-isolated context}}
+  }
+
+  useValue(ns)
+}

test/Concurrency/transfernonsendable_isolationcrossing_partialapply.swift

@@ -36,18 +36,19 @@ func doSomething(_ x: NonSendableKlass, _ y: NonSendableKlass) { }
 actor ProtectsNonSendable {
   var ns: NonSendableKlass = .init()
 
-  nonisolated func testParameter(_ ns: NonSendableKlass) async {
+  nonisolated func testParameter(_ nsArg: NonSendableKlass) async {
+    // TODO: This is wrong, we should get an error saying that nsArg is task
+    // isolated since this is nonisolated.
     self.assumeIsolated { isolatedSelf in
-      isolatedSelf.ns = ns // expected-warning {{task-isolated value of type 'NonSendableKlass' transferred to actor-isolated context; later accesses to value could race}}
+      isolatedSelf.ns = nsArg // expected-warning {{actor-isolated value of type 'NonSendableKlass' transferred to actor-isolated context; later accesses to value could race}}
     }
   }
 
-  // This should get the note since l is different from 'ns'.
-  nonisolated func testParameterMergedIntoLocal(_ ns: NonSendableKlass) async {
+  nonisolated func testParameterMergedIntoLocal(_ nsArg: NonSendableKlass) async {
     let l = NonSendableKlass()
-    doSomething(l, ns)
+    doSomething(l, nsArg)
     self.assumeIsolated { isolatedSelf in
-      isolatedSelf.ns = l // expected-warning {{task-isolated value of type 'NonSendableKlass' transferred to actor-isolated context; later accesses to value could race}}
+      isolatedSelf.ns = l // expected-warning {{actor-isolated value of type 'NonSendableKlass' transferred to actor-isolated context; later accesses to value could race}}
     }
   }