[VM/Compiler] Mark instructions related to late initialization error checks as synthetic

TEST=pkg/vm_service/test/breakpoints_ignore_late_initialization_error_instructions_test.dart

Fixes: #53376
Change-Id: Iab7d2489f29bfc4a586b9de6e3caa0a7c1a35454
Reviewed-on: https://dart-review.googlesource.com/c/sdk/+/355000
Reviewed-by: Ben Konyi <bkonyi@google.com>
Commit-Queue: Derek Xu <derekx@google.com>

Author: derekxu16

pkg/vm_service/test/breakpoints_ignore_late_initialization_error_instructions_test.dart

@@ -0,0 +1,79 @@
+// 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.
+
+// Regression test for https://dartbug.com/53376.
+
+import 'common/service_test_common.dart';
+import 'common/test_helper.dart';
+
+const String shortFile =
+    'breakpoints_ignore_late_initialization_error_instructions_test.dart';
+
+// AUTOGENERATED START
+//
+// Update these constants by running:
+//
+// dart pkg/vm_service/test/update_line_numbers.dart <test.dart>
+//
+const LINE_A = 33;
+const LINE_B = 42;
+const LINE_C = 51;
+// AUTOGENERATED END
+
+int getThree() => 3;
+
+void testeeMain() {
+  // ignore: prefer_final_locals
+  late int x = 1;
+  // When a late variable is read, the VM performs checks to ensure that the
+  // variable has been initialized. When a breakpoint is set on the following
+  // line, it should resolve to the [toDouble] call instruction, not to an
+  // instruction part of the late variable initialization checks.
+  final double xd = x.toDouble(); // LINE_A
+  print(xd);
+
+  late final int y = 2;
+  // When a late final variable is read, the VM performs checks to ensure that
+  // the variable has been assigned a value exactly once. When a breakpoint is
+  // set on the following line, it should resolve to the [toDouble] call
+  // instruction, not to an instruction part of the late variable assignment
+  // checks.
+  final double yd = y.toDouble(); // LINE_B
+  print(yd);
+
+  late final int z;
+  // When a late final variable is assigned a value, the VM performs checks to
+  // ensure that the variable has not already been initialized. When a
+  // breakpoint is set on the following line, it should resolve to the
+  // [getThree] call instruction, not to an instruction part of the late
+  // variable initialization checks.
+  z = getThree(); // LINE_C
+  print(z);
+}
+
+List<String> stops = [];
+
+const List<String> expected = [
+  '$shortFile:$LINE_A:23', // on 'toDouble'
+  '$shortFile:$LINE_B:23', // on 'toDouble'
+  '$shortFile:$LINE_C:7', // on 'getThree'
+];
+
+final tests = <IsolateTest>[
+  hasPausedAtStart,
+  setBreakpointAtLine(LINE_A),
+  setBreakpointAtLine(LINE_B),
+  setBreakpointAtLine(LINE_C),
+  resumeProgramRecordingStops(stops, false),
+  checkRecordedStops(stops, expected),
+];
+
+Future<void> main([args = const <String>[]]) => runIsolateTests(
+      args,
+      tests,
+      shortFile,
+      testeeConcurrent: testeeMain,
+      pauseOnStart: true,
+      pauseOnExit: true,
+    );

runtime/vm/compiler/frontend/kernel_to_il.cc

@@ -511,8 +511,9 @@ Fragment FlowGraphBuilder::ThrowLateInitializationError(
 
   // Call LateError._throwFoo.
   instructions += Constant(name);
-  instructions += StaticCall(position, throw_new,
-                             /* argument_count = */ 1, ICData::kStatic);
+  instructions +=
+      StaticCall(TokenPosition::Synthetic(position.Pos()), throw_new,
+                 /* argument_count = */ 1, ICData::kStatic);
   instructions += Drop();
 
   return instructions;