Cannot check array[0].lengh variable in debugger

首先在 VS Code 中运行附带的 TestDebugger.java.txt 复现，并结合调试器对 array.length 和 array[0].length 的表达式求值行为检查 client.log.2023-08-24.txt。监视表达式以及涉及 array[0].length 的条件断点能够无错误地求值，即表示完成。

Hi everyone.

I have an issue when trying to debug a program that contains 2D array. If I try to put breakpoints checking for array[0].length, it fails with:

Breakpoint condition 'array[0].length > 0' error: Cannot evaluate because of compilation error(s): length cannot be resolved or is not a field.

After somme diggining, it seems that the debugger considers the array[0] object as a double:

Breakpoint condition 'array[0][0] == 0' error: Cannot evaluate because of compilation error(s): The type of the expression must be an array type but it resolved to double.

Do you have any idea on how to solve this?

Thanks

Nicolas

Environment

• Operating System: Ubuntu 22.04.3 LTS
• JDK version:

openjdk 19.0.2 2023-01-17
OpenJDK Runtime Environment (build 19.0.2+7-Ubuntu-0ubuntu322.04)
OpenJDK 64-Bit Server VM (build 19.0.2+7-Ubuntu-0ubuntu322.04, mixed mode, sharing)

• Visual Studio Code version:

Version: 1.81.1
Commit: 6c3e3dba23e8fadc360aed75ce363ba185c49794
Date: 2023-08-09T22:18:39.991Z
Electron: 22.3.18
ElectronBuildId: 22689846
Chromium: 108.0.5359.215
Node.js: 16.17.1
V8: 10.8.168.25-electron.0
OS: Linux x64 6.2.0-26-generic snap

• Java extension version: Java Extension Pack (v0.25.13)
• Java Debugger extension version: v0.53.0

Steps To Reproduce

1. Add in Watch array.length
2. Add in Watch array[0].length
3. Add coniditional breakpoint in line 15: array[0].length > 0

Current Result

Breakpoint condition 'array[0].length > 0' error: Cannot evaluate because of compilation error(s): length cannot be resolved or is not a field.

Expected Result

Debugger should stop on breakpoint without error

Files

Code source: TestDebugger.java.txt
Log file:
client.log.2023-08-24.txt