[SILGen] avoid hop before autoreleased foreign error is retained

lib/SILGen/SILGenApply.cpp

@@ -5608,10 +5608,6 @@ RValue SILGenFunction::emitApply(
     // plan's finish method is called, because it must happen in the
     // successors of the `await_async_continuation` terminator.
     resultPlan->deferExecutorBreadcrumb(std::move(breadcrumb));
-
-  } else {
-    // In the ordinary case, we hop back to the current executor
-    breadcrumb.emit(*this, loc);
   }
 
   // Pop the argument scope.
@@ -5684,6 +5680,14 @@ RValue SILGenFunction::emitApply(
         });
   }
 
+  if (!calleeTypeInfo.foreign.async) {
+    // For a non-foreign-async callee, we hop back to the current executor
+    // _after_ popping the argument scope and collecting the results. This is
+    // important because we may need to, for example, retain one of the results
+    // prior to changing actors in the case of an autorelease'd return value.
+    breadcrumb.emit(*this, loc);
+  }
+
   SILValue bridgedForeignError;
   // If there was a foreign error convention, consider it.
   // TODO: maybe this should happen after managing the result if it's

test/Concurrency/isolated_default_argument_eval.swift

@@ -20,6 +20,8 @@ func nonisolatedAsyncCaller() async {
   // CHECK: [[GETARG:%[0-9]+]] = function_ref @$s30isolated_default_argument_eval19mainActorDefaultArg5valueySi_tFfA_
   // CHECK: hop_to_executor {{.*}} : $MainActor
   // CHECK-NEXT: apply [[GETARG]]()
+  // CHECK-NEXT: end_borrow {{.*}} : $MainActor
+  // CHECK-NEXT: destroy_value {{.*}} : $MainActor
   // CHECK-NEXT: hop_to_executor {{.*}} : $Optional<Builtin.Executor>
   await mainActorDefaultArg()
 }

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

@@ -336,4 +336,11 @@ MAIN_ACTOR
 @property(readonly) BOOL isVisible;
 @end
 
+// rdar://114049646
+MAIN_ACTOR
+@protocol HotdogCompetitor
+- (nullable NSString *)pileOfHotdogsToEatWithLimit:(NSObject *)limit
+                                                   error:(NSError * __autoreleasing *)error;
+@end
+
 #pragma clang assume_nonnull end

test/SILGen/async_initializer.swift

@@ -131,7 +131,7 @@ enum Birb {
 // CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:          hop_to_executor {{%[0-9]+}} : $MainActor
 // CHECK-NEXT:     {{%[0-9]+}} = apply {{%[0-9]+}}({{%[0-9]+}}, {{%[0-9]+}}) : $@convention(method) (@owned String, @thick Cat.Type) -> @owned Cat
-// CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
+// CHECK:          hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:        } // end sil function '$s12initializers7makeCatyyYaF'
 func makeCat() async {
   _ = await Cat(name: "Socks")
@@ -142,7 +142,7 @@ func makeCat() async {
 // CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:          hop_to_executor {{%[0-9]+}} : $MainActor
 // CHECK-NEXT:     {{%[0-9]+}} = apply {{%[0-9]+}}({{%[0-9]+}}, {{%[0-9]+}}) : $@convention(method) (@owned String, @thin Dog.Type) -> Dog
-// CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
+// CHECK:          hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:        } // end sil function '$s12initializers7makeDogyyYaF'
 func makeDog() async {
   _ = await Dog(name: "Lassie")
@@ -153,7 +153,7 @@ func makeDog() async {
 // CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:          hop_to_executor {{%[0-9]+}} : $MainActor
 // CHECK-NEXT:     {{%[0-9]+}} = apply {{%[0-9]+}}({{%[0-9]+}}, {{%[0-9]+}}) : $@convention(method) (@owned String, @thin Birb.Type) -> Birb
-// CHECK-NEXT:     hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
+// CHECK:          hop_to_executor [[GENERIC_EXEC]] : $Optional<Builtin.Executor>
 // CHECK:        } // end sil function '$s12initializers8makeBirbyyYaF'
 func makeBirb() async {
   _ = await Birb(name: "Chirpy")

test/SILGen/hop_to_executor.swift

@@ -47,7 +47,7 @@ actor MyActor {
   // CHECK:        [[BORROWED_SELF:%[0-9]+]] = begin_borrow %0 : $MyActor
   // CHECK:        hop_to_executor [[BORROWED_SELF]] : $MyActor 
   // CHECK:        = apply {{.*}} : $@convention(method) @async (Int, @guaranteed MyActor) -> ()
-  // CHECK-NEXT:   hop_to_executor [[BORROWED_SELF]] : $MyActor 
+  // CHECK:        hop_to_executor [[BORROWED_SELF]] : $MyActor
   // CHECK:      } // end sil function '$s4test7MyActorC0A22ConsumingAsyncFunctionyyYaF'
   __consuming func testConsumingAsyncFunction() async {
     await callee(p)
@@ -225,8 +225,8 @@ actor BlueActorImpl {
 // CHECK:       [[METH:%[0-9]+]] = class_method [[REDBORROW]] : $RedActorImpl, #RedActorImpl.hello : (isolated RedActorImpl) -> (Int) -> (), $@convention(method) (Int, @guaranteed RedActorImpl) -> ()
 // CHECK:       hop_to_executor [[REDBORROW]] : $RedActorImpl
 // CHECK-NEXT:  = apply [[METH]]([[INTARG]], [[REDBORROW]]) : $@convention(method) (Int, @guaranteed RedActorImpl) -> ()
+// CHECK-NEXT:  end_borrow [[REDBORROW]] : $RedActorImpl
 // CHECK-NEXT:  hop_to_executor [[BLUE]] : $BlueActorImpl
-// CHECK:       end_borrow [[REDBORROW]] : $RedActorImpl
 // CHECK:       destroy_value [[REDMOVE]] : $RedActorImpl
 // CHECK: } // end sil function '$s4test13BlueActorImplC14createAndGreetyyYaF'
   func createAndGreet() async {
@@ -272,9 +272,9 @@ struct BlueActor {
 // CHECK:       hop_to_executor [[REDEXE]] : $RedActorImpl
       // ---- now invoke redFn, hop back to Blue, and clean-up ----
 // CHECK-NEXT:  {{%[0-9]+}} = apply [[CALLEE]]([[ARG]]) : $@convention(thin) (Int) -> ()
+// CHECK-NEXT:  end_borrow [[REDEXE]] : $RedActorImpl
+// CHECK-NEXT:  destroy_value [[R]] : $RedActorImpl
 // CHECK-NEXT:  hop_to_executor [[BLUEEXE]] : $BlueActorImpl
-// CHECK:       end_borrow [[REDEXE]] : $RedActorImpl
-// CHECK:       destroy_value [[R]] : $RedActorImpl
 // CHECK:       end_borrow [[BLUEEXE]] : $BlueActorImpl
 // CHECK:       destroy_value [[B]] : $BlueActorImpl
 // CHECK: } // end sil function '$s4test6blueFnyyYaF'
@@ -288,8 +288,9 @@ struct BlueActor {
 // CHECK:         [[BORROW:%[0-9]+]] = begin_borrow {{%[0-9]+}} : $RedActorImpl
 // CHECK-NEXT:    hop_to_executor [[BORROW]] : $RedActorImpl
 // CHECK-NEXT:    {{%[0-9]+}} = apply {{%[0-9]+}}({{%[0-9]+}}) : $@convention(thin) (Int) -> ()
-// CHECK-NEXT:    hop_to_executor [[GENERIC_EXEC]]
 // CHECK-NEXT:    end_borrow [[BORROW]] : $RedActorImpl
+// CHECK-NEXT:    destroy_value
+// CHECK-NEXT:    hop_to_executor [[GENERIC_EXEC]]
 // CHECK: } // end sil function '$s4test20unspecifiedAsyncFuncyyYaF'
 func unspecifiedAsyncFunc() async {
   await redFn(200)
@@ -316,7 +317,7 @@ func anotherUnspecifiedAsyncFunc(_ red : RedActorImpl) async {
 // CHECK: hop_to_executor [[RED:%[0-9]+]] : $RedActorImpl
 // CHECK-NEXT: begin_borrow
 // CHECK-NEXT: apply
-// CHECK-NEXT: hop_to_executor [[GENERIC_EXEC:%[0-9]+]] : $Optional<Builtin.Executor>
+// CHECK:      hop_to_executor [[GENERIC_EXEC:%[0-9]+]] : $Optional<Builtin.Executor>
 func testGlobalActorFuncValue(_ fn: @RedActor () -> Void) async {
   await fn()
 }

test/SILGen/hop_to_executor_async_prop.swift

@@ -123,9 +123,9 @@ func accessSweaterOfSweater(cat : Cat) async -> Sweater {
 
 // CHECK:    hop_to_executor [[GLOBAL_CAT]] : $Cat
 // CHECK:    [[THE_STRING:%[0-9]+]] = apply [[GETTER]]([[CAT]]) : $@convention(method) (@guaranteed Cat) -> @owned String
-// CHECK:    hop_to_executor [[GENERIC_EXEC]]
 // CHECK:    end_borrow [[GLOBAL_CAT]] : $Cat
 // CHECK:    destroy_value [[GLOBAL_CAT_REF]] : $Cat
+// CHECK:    hop_to_executor [[GENERIC_EXEC]]
 // CHECK:    return [[THE_STRING]] : $String
 // CHECK: } // end sil function '$s4test26accessGlobalIsolatedMember3catSSAA3CatC_tYaF'
 func accessGlobalIsolatedMember(cat : Cat) async -> String {

test/SILGen/objc_async.swift

@@ -301,3 +301,21 @@ extension OptionalMemberLookups {
     await self.generateMaybe!()
   }
 }
+
+
+// CHECK-LABEL: sil {{.*}} @$s10objc_async12checkHotdogsySSSgx_So8NSObjectCtYaKSo16HotdogCompetitorRzlF
+// CHECK: hop_to_executor {{.*}} : $MainActor
+// CHECK: [[AUTO_REL_STR:%.*]] = apply {{.*}}<some HotdogCompetitor>({{.*}}) : $@convention(objc_method)
+// CHECK: [[UNMANAGED_OPTIONAL:%.*]] = load [trivial] {{.*}} : $*@sil_unmanaged Optional<NSError>
+// CHECK: [[MANAGED_OPTIONAL:%.*]] = unmanaged_to_ref [[UNMANAGED_OPTIONAL]] : $@sil_unmanaged Optional<NSError> to $Optional<NSError>
+// CHECK: [[RETAINED_OPTIONAL:%.*]] = copy_value [[MANAGED_OPTIONAL]] : $Optional<NSError>
+// CHECK: [[MARKED:%.*]] = mark_dependence [[RETAINED_OPTIONAL]] : $Optional<NSError> on {{.*}} : $*Optional<NSError> // user: %32
+// CHECK: assign [[MARKED]] to {{.*}} : $*Optional<NSError>
+// CHECK: destroy_value {{.*}} : $MainActor
+// CHECK: dealloc_stack {{.*}} : $*AutoreleasingUnsafeMutablePointer<Optional<NSError>>
+// CHECK: dealloc_stack {{.*}} : $*@sil_unmanaged Optional<NSError>
+// CHECK: hop_to_executor {{.*}} : $Optional<Builtin.Executor>
+// CHECK: switch_enum
+func checkHotdogs(_ v: some HotdogCompetitor, _ timeLimit: NSObject) async throws -> String? {
+    return try await v.pileOfHotdogsToEat(withLimit: timeLimit)
+}

test/SILGen/toplevel_globalactorvars.swift

@@ -66,8 +66,8 @@ await printFromMyActor(value: a)
 // CHECK: [[ACTORREF:%[0-9]+]] = begin_borrow {{%[0-9]+}} : $MyActorImpl
 // CHECK: hop_to_executor [[ACTORREF]] : $MyActorImpl
 // CHECK: {{%[0-9]+}} = apply [[PRINTFROMMYACTOR_FUNC]]([[AGLOBAL]])
-// CHECK: hop_to_executor [[MAIN_OPTIONAL]]
 // CHECK: end_borrow [[ACTORREF]]
+// CHECK: hop_to_executor [[MAIN_OPTIONAL]]
 
 if a < 10 {
 // CHECK: [[AACCESS:%[0-9]+]] = begin_access [read] [dynamic] [[AREF]] : $*Int
@@ -120,6 +120,6 @@ if a < 10 {
     // CHECK: [[ACTORREF:%[0-9]+]] = begin_borrow {{%[0-9]+}} : $MyActorImpl
     // CHECK: hop_to_executor [[ACTORREF]] : $MyActorImpl
     // CHECK: {{%[0-9]+}} = apply [[PRINTFROMMYACTOR_FUNC]]([[AGLOBAL]])
-    // CHECK: hop_to_executor [[MAIN_OPTIONAL]]
     // CHECK: end_borrow [[ACTORREF]]
+    // CHECK: hop_to_executor [[MAIN_OPTIONAL]]
 }