Possible memory leak related to `lldb-mi`

[hackroid]

Environment

• OS and version: macOS Ventura 13.0.1 (22A400)
• VS Code:
  • Version: 1.73.1
  • Commit: 6261075646f055b99068d3688932416f2346dd3b
  • Date: 2022-11-09T02:22:48.959Z
  • Electron: 19.0.17
  • Chromium: 102.0.5005.167
  • Node.js: 16.14.2
  • V8: 10.2.154.15-electron.0
  • OS: Darwin arm64 22.1.0
  • Sandboxed: No
• C/C++ extension: v1.12.4
• GDB / LLDB version: lldb-1400.0.38.13, Apple Swift version 5.7.1 (swiftlang-5.7.1.135.3 clang-1400.0.29.51)

Bug Summary and Steps to Reproduce

Bug Summary: lldb-mi kept eating memory (about +500MB/s) when debugging until the whole macOS froze.

Steps to reproduce:

1. Debug the following snippet with the provided environment above

   
   #include <iostream>
   #include <vector>
   
   using namespace std;
   
   int main()
   {
       vector<int> nn(4, 0);
       for (size_t i = 0; i < 4; i++) {
           int tt;
           cin >> tt;
           nn[i] = tt;
       }
       vector<int> k;
       cout << nn[1];
       return 0;
   }

2. With the config(launch/task) provided below
3. Make a break point at line 14: vector<int> k;
4. Start debugging
5. Input 4 integers 5 2 6 1 , press enter, then be like this
6. Variables monitor will show nothing but loading...
7. Open Activity Monitor (macOS app), lldb-mi start using lots of memory
8. Stop debugging, close the terminal windows, lldb-mi still won't stop and keep eating memory
9. Can stop lldb-mi only by force quit.

Debugger Configurations

{
    "configurations": [
        {
            "name": "clang++ dbg",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}/${fileBasenameNoExtension}",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${fileDirname}",
            "environment": [],
            "externalConsole": true,
            "MIMode": "lldb",
            "preLaunchTask": "C/C++: clang++ build active file",
            "logging": { "engineLogging": true, "trace": true, "traceResponse": true }
        }
    ],
    "version": "2.0.0"
}

{
    "tasks": [
        {
            "type": "cppbuild",
            "label": "C/C++: clang++ build active file",
            "command": "/usr/bin/clang++",
            "args": [
                "-fdiagnostics-color=always",
                "-g",
                "${file}",
                "-o",
                "${fileDirname}/${fileBasenameNoExtension}"
            ],
            "options": {
                "cwd": "${fileDirname}"
            },
            "problemMatcher": [
                "$gcc"
            ],
            "group": "build",
            "detail": "Task generated by Debugger."
        }
    ],
    "version": "2.0.0"
}

Debugger Logs

https://blog.hackroid.com/debug-log.html

Other Extensions

No response

Additional Information

No response

[hackroid]

Small changes to the code will avoid the problem, but, just wondering why. Like: line 10: move int tt; outside the for loop. Or like: line 9: change size_t to int.

[H-G-Hristov]

It's broken. I switched to CodeLLDB for debugging on macOS.

https://github.com/microsoft/vscode-cpptools/issues/9831

[bobbrow]

@WardenGnaw have you seen this?

[WardenGnaw]

Yeah, this is due to the external dependency the debugger uses lldb-mi.

[zanmato1984]

Observed the exact same issue, i.e., local variable keep loading, lldb-mi showing significant memory consumption after a while.

OS

macOS Ventura Version 13.2.1 (22D68)

VSCode

Version: 1.76.2 Commit: ee2b180d582a7f601fa6ecfdad8d9fd269ab1884 Date: 2023-03-14T17:53:46.528Z Electron: 19.1.11 Chromium: 102.0.5005.196 Node.js: 16.14.2 V8: 10.2.154.26-electron.0 OS: Darwin arm64 22.3.0 Sandboxed: No

[zanmato1984]

It's broken. I switched to CodeLLDB for debugging on macOS.

9831

This works for me too. Thanks bro!

[denniskb]

Same issue when trying to step through a googletest test case that involves popen(). Stepping through any other code is smooth and leak-free.