[VM] Mark initializing formal variables as invisible

Fixes #59661

Tested: pkg/vm_service/test/issue_59661.dart and existing tests.
Change-Id: I09f708dabfeb71ae8aa078d73fc23295562a451c
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/399900
Commit-Queue: Jens Johansen <[email protected]>
Reviewed-by: Ben Konyi <[email protected]>

Author: jensjoha

pkg/vm_service/test/issue_59661.dart

@@ -0,0 +1,139 @@
+// Copyright (c) 2024, 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';
+
+// AUTOGENERATED START
+//
+// Update these constants by running:
+//
+// dart pkg/vm_service/test/update_line_numbers.dart <test.dart>
+//
+const LINE_CLASS_A = 29;
+const LINE_CLASS_A_NAMED = 34;
+const LINE_CLASS_A_NAMED2_BREAK_1 = 40;
+const LINE_CLASS_A_NAMED2_BREAK_2 = 43;
+const LINE_CLASS_A_NAMED2_BREAK_3 = 46;
+const LINE_CLASS_B = 55;
+// AUTOGENERATED END
+
+class A {
+  List list;
+  A(this.list) {
+    list = [3];
+    debugger(); // LINE_CLASS_A
+    print(list);
+  }
+  A.named(this.list) {
+    list = [4];
+    debugger(); // LINE_CLASS_A_NAMED
+    print(list);
+  }
+  A.named2(this.list) {
+    {
+      final list = [5];
+      debugger(); // LINE_CLASS_A_NAMED2_BREAK_1
+      print(list);
+    }
+    debugger(); // LINE_CLASS_A_NAMED2_BREAK_2
+    print(list);
+    list = [6];
+    debugger(); // LINE_CLASS_A_NAMED2_BREAK_3
+    print(list);
+  }
+  A.noDebugger(this.list);
+}
+
+class B extends A {
+  B(super.list) : super.noDebugger() {
+    list = [7];
+    debugger(); // LINE_CLASS_B
+    print(list);
+  }
+}
+
+void code() {
+  A([1, 2]);
+  A.named([1, 2]);
+  A.named2([1, 2]);
+  B([1, 2]);
+}
+
+Future<void> Function(VmService, IsolateRef) test(
+  String topFrameName,
+  List<String> availableVariables,
+  List<(String evaluate, String evaluationResult)> evaluations,
+) {
+  return (VmService service, IsolateRef isolateRef) async {
+    final isolateId = isolateRef.id!;
+    final stack = await service.getStack(isolateId);
+
+    // Make sure we are in the right place.
+    expect(stack.frames!.length, greaterThanOrEqualTo(1));
+    expect(stack.frames![0].function!.name, topFrameName);
+
+    // Check variables.
+    expect(
+      (stack.frames![0].vars ?? []).map((v) => v.name).toList(),
+      equals(availableVariables),
+    );
+
+    // Evaluate.
+    for (final (expression, expectedResult) in evaluations) {
+      final dynamic result = await service.evaluateInFrame(
+        isolateId,
+        /* frame = */ 0,
+        expression,
+      );
+      print(result.valueAsString);
+      expect(result.valueAsString, equals(expectedResult));
+    }
+  };
+}
+
+final tests = <IsolateTest>[
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_A),
+  test('A', ['this'], [('list.toString()', '[3]')]),
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_A_NAMED),
+  test('A.named', ['this'], [('list.toString()', '[4]')]),
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_A_NAMED2_BREAK_1),
+  test(
+    'A.named2',
+    ['this', 'list'],
+    [
+      ('list.toString()', '[5]'),
+      ('this.list.toString()', '[1, 2]'),
+    ],
+  ),
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_A_NAMED2_BREAK_2),
+  test('A.named2', ['this'], [('list.toString()', '[1, 2]')]),
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_A_NAMED2_BREAK_3),
+  test('A.named2', ['this'], [('list.toString()', '[6]')]),
+  resumeIsolate,
+  hasStoppedAtBreakpoint,
+  stoppedAtLine(LINE_CLASS_B),
+  test('B', ['this'], [('list.toString()', '[7]')]),
+];
+
+void main([args = const <String>[]]) => runIsolateTests(
+      args,
+      tests,
+      'issue_59661.dart',
+      testeeConcurrent: code,
+      pauseOnStart: false,
+      pauseOnExit: true,
+    );

runtime/vm/compiler/frontend/kernel_translation_helper.h

@@ -412,6 +412,7 @@ class VariableDeclarationHelper {
     kFinal = 1 << 0,
     kConst = 1 << 1,
     kHasDeclaredInitializer = 1 << 2,
+    kIsInitializingFormal = 1 << 3,
     kIsGenericCovariantImpl = 1 << 4,
     kLate = 1 << 5,
     kRequired = 1 << 6,
@@ -420,6 +421,7 @@ class VariableDeclarationHelper {
     kSynthesized = 1 << 9,
     kHoisted = 1 << 10,
     kWildcard = 1 << 11,
+    kIsSuperInitializingFormal = 1 << 12,
   };
 
   explicit VariableDeclarationHelper(KernelReaderHelper* helper)
@@ -442,6 +444,12 @@ class VariableDeclarationHelper {
   bool IsSynthesized() const { return (flags_ & kSynthesized) != 0; }
   bool IsHoisted() const { return (flags_ & kHoisted) != 0; }
   bool IsWildcard() const { return (flags_ & kWildcard) != 0; }
+  bool IsInitializingFormal() const {
+    return (flags_ & kIsInitializingFormal) != 0;
+  }
+  bool IsSuperInitializingFormal() const {
+    return (flags_ & kIsSuperInitializingFormal) != 0;
+  }
   bool HasDeclaredInitializer() const {
     return (flags_ & kHasDeclaredInitializer) != 0;
   }

runtime/vm/compiler/frontend/scope_builder.cc

@@ -1408,7 +1408,8 @@ void ScopeBuilder::VisitVariableDeclaration() {
     variable->set_is_late();
     variable->set_late_init_offset(initializer_offset);
   }
-  if (helper.IsSynthesized() || helper.IsWildcard()) {
+  if (helper.IsSynthesized() || helper.IsWildcard() ||
+      helper.IsInitializingFormal() || helper.IsSuperInitializingFormal()) {
     variable->set_invisible(true);
   }
 
@@ -1715,7 +1716,8 @@ void ScopeBuilder::AddVariableDeclarationParameter(
   if (helper.IsCovariant()) {
     variable->set_is_explicit_covariant_parameter();
   }
-  if (helper.IsWildcard()) {
+  if (helper.IsWildcard() || helper.IsInitializingFormal() ||
+      helper.IsSuperInitializingFormal()) {
     variable->set_invisible(true);
   }