| // Copyright 2020 the V8 project authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| var Debug = debug.Debug; |
| |
| var frame; |
| |
| Debug.setListener(function (event, exec_state, event_data, data) { |
| if (event == Debug.DebugEvent.Break) { |
| frame = exec_state.frame(0); |
| |
| // Try changing the value, which hasn't yet been initialized. |
| assertEquals(3, frame.evaluate("result = 3").value()); |
| assertEquals(3, frame.evaluate("result").value()); |
| } |
| }); |
| |
| function makeCounter() { |
| // If the variable `result` were stack-allocated, it would be 3 at this point |
| // due to the debugging activity during function entry. However, for a |
| // heap-allocated variable, the debugger evaluated `result = 3` in a temporary |
| // scope instead and had no effect on this variable. |
| assertEquals(undefined, result); |
| |
| var result = 0; |
| |
| // Regardless of how `result` is allocated, it should now be initialized. |
| assertEquals(0, result); |
| |
| // Close over `result` to cause it to be heap-allocated. |
| return () => ++result; |
| } |
| |
| // Break on entry to a function which includes heap-allocated variables. |
| %ScheduleBreak(); |
| makeCounter(); |
| |
| // Check the frame state which was collected during the breakpoint. |
| assertEquals(1, frame.localCount()); |
| assertEquals('result', frame.localName(0)); |
| assertEquals(undefined, frame.localValue(0).value()); |
| assertEquals(3, frame.scopeCount()); |
| assertEquals(debug.ScopeType.Local, frame.scope(0).scopeType()); |
| assertEquals(debug.ScopeType.Script, frame.scope(1).scopeType()); |
| assertEquals(debug.ScopeType.Global, frame.scope(2).scopeType()); |