Merge pull request #81943 from gottesmm/release/6.2-rdar152436817

[6.2][rbi] Lookthrough an invocation of DistributedActor.asLocalActor when determining actor instances.

Author: gottesmm

lib/SILOptimizer/Utils/SILIsolationInfo.cpp

@@ -13,6 +13,7 @@
 #include "swift/SILOptimizer/Utils/SILIsolationInfo.h"
 
 #include "swift/AST/ASTWalker.h"
+#include "swift/AST/DistributedDecl.h"
 #include "swift/AST/Expr.h"
 #include "swift/SIL/AddressWalker.h"
 #include "swift/SIL/ApplySite.h"
@@ -1336,6 +1337,30 @@ SILValue ActorInstance::lookThroughInsts(SILValue value) {
       }
     }
 
+    // See if this is distributed asLocalActor. In such a case, we want to
+    // consider the result actor to be the same actor as the input isolated
+    // parameter.
+    if (auto fas = FullApplySite::isa(svi)) {
+      if (auto *functionRef = fas.getReferencedFunctionOrNull()) {
+        if (auto declRef = functionRef->getDeclRef()) {
+          if (auto *accessor =
+                  dyn_cast_or_null<AccessorDecl>(declRef.getFuncDecl())) {
+            if (auto asLocalActorDecl =
+                    getDistributedActorAsLocalActorComputedProperty(
+                        functionRef->getDeclContext()->getParentModule())) {
+              if (auto asLocalActorGetter =
+                      asLocalActorDecl->getAccessor(AccessorKind::Get);
+                  asLocalActorGetter && asLocalActorGetter == accessor) {
+                value = lookThroughInsts(
+                    fas.getIsolatedArgumentOperandOrNullPtr()->get());
+                continue;
+              }
+            }
+          }
+        }
+      }
+    }
+
     break;
   }
 

test/Distributed/distributed_actor_transfernonsendable.swift

@@ -65,6 +65,19 @@ distributed actor MyDistributedActor {
       // expected-note @-1 {{'self'-isolated 'x' is captured by a main actor-isolated closure. main actor-isolated uses in closure may race against later nonisolated uses}}
     }
   }
+
+
+  func doSomething() async { }
+
+  // Make sure that we consider asLocalActor's result to be the same actor as
+  // its actor parameter.
+  func testAsLocalActorForwards() async {
+    await withTaskGroup { group in
+      group.addTask {
+        await self.doSomething()
+      }
+    }
+  }
 }
 
 /////////////////////////////////