[VM | VMService] Fix expression evaluation when recursive types are used.
Bug:49209
TEST=pkg/vm_service/test/eval_issue_49209_test.dart
Change-Id: I7da8a195a624b34519aa64fffc248cad0fb7e6fb
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/247901
Reviewed-by: Kenzie Davisson <kenzieschmoll@google.com>
Reviewed-by: Ben Konyi <bkonyi@google.com>
diff --git a/pkg/vm_service/test/eval_issue_49209_test.dart b/pkg/vm_service/test/eval_issue_49209_test.dart
new file mode 100644
index 0000000..a0bbd56
--- /dev/null
+++ b/pkg/vm_service/test/eval_issue_49209_test.dart
@@ -0,0 +1,49 @@
+// Copyright (c) 2022, the Dart project authors. Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+import 'dart:developer';
+import 'package:test/test.dart';
+import 'package:vm_service/vm_service.dart';
+import 'common/service_test_common.dart';
+import 'common/test_helper.dart';
+
+void testFunction() {
+ final a = A<C>();
+ print(a.runtimeType);
+ debugger();
+}
+
+class A<T> {
+ A();
+}
+
+class B<T> {
+ final T data;
+ B(this.data);
+}
+
+class C extends B<C> {
+ C(C data) : super(data);
+}
+
+var tests = <IsolateTest>[
+ hasStoppedAtBreakpoint,
+
+ // Evaluate against top frame.
+ (VmService service, IsolateRef isolateRef) async {
+ final isolateId = isolateRef.id!;
+ var topFrame = 0;
+ final dynamic result = await service.evaluateInFrame(
+ isolateId, topFrame, 'a.runtimeType.toString()');
+ print(result);
+ expect(result.valueAsString, equals("A<C>"));
+ },
+];
+
+main([args = const <String>[]]) => runIsolateTests(
+ args,
+ tests,
+ 'eval_issue_49209_test.dart',
+ testeeConcurrent: testFunction,
+ );
diff --git a/runtime/vm/service.cc b/runtime/vm/service.cc
index c056360..85cf403 100644
--- a/runtime/vm/service.cc
+++ b/runtime/vm/service.cc
@@ -2881,6 +2881,13 @@
output.Add(instance);
return;
}
+ if (type.IsTypeRef()) {
+ // A TypeRef is used to break cycles in the representation of types
+ // calling type class on it will cause an infinite recursion.
+ // We use null instead.
+ output.Add(instance);
+ return;
+ }
const Class& cls = Class::Handle(type.type_class());
const Library& lib = Library::Handle(zone, cls.library());
