Debugging meson

Recently I started using meson for personal mini projects. I have used CMake in the past and my personal impression is that things get rapidly complicated and I believe they don't need to be like so. I prefer meson for its simplicity.

These days meson build seems promising except its Xcode support is not very good (apparently not many Xcode users use meson). So I decided to fix it myself (at least the parts I know). I write my notes here since I am not very familiar with python and its development environment.

Notes on how to debug/fix issues with meson

1. Clone meson

   git clone git@github.com:mesonbuild/meson.git
   

2. Open meson directory in Visual Code

   code meson
   

3. Create settings.json and launch.json
   
   • settings.json
     Create settings.json to make sure the correct python version (3.5 or above) is set for the workspace (and also because I want Visual Code stop asking me frequently if it should install a linter. I set it to no because I already set the git commit hook recommended for this project. )
     
     This is my .vscode/settings.json file:

     {
         "python.linting.pylintEnabled": false,
         "python.pythonPath": "/usr/local/bin/python3"
     }
     

   • launch.json
     Create launch.json to be able to start the debugger from within the editor window and be able to put breakpoints and inspect variables more easily.
     Simple create file .vscode/launch.json with below contents.

     FYI: To create the default launch,json file change to the debug pane (Shift + Cmd + D) and add a configuration; The file will be created with various debug configurations. Most of them are for server/client development and are not relevant to meson project, feel free to delete them if not needed.

     
     This is my .vscode/launch.json file:

     {
         "version": "0.2.0",
         "configurations": [
             // Configuration that uses meson.py to run one of the project tests.
             // Move to a test dir and execute `meson.py build --backend=xcode`.
             {
                 "name": "run project test 1",
                 "type": "python",
                 "request": "launch",
                 "program": "${workspaceFolder}/meson.py",
                 "console": "integratedTerminal",
                 "args": [
                     "build",
                     "--backend=xcode",
                 ],
                 "cwd": "${workspaceFolder}/test cases/common/1 trivial"
             },
             // Configuration that uses run_unittests.py to run a particular test.
             // Move to root directory and execute:
             // `run_unittests.py -v TestCase.testMethod`. Since `--backend=xcode`
             // cannot be set via an argument use an environment variable.
             {
                 "name": "run_unittests.py",
                 "type": "python",
                 "request": "launch",
                 "program": "${workspaceFolder}/run_unittests.py",
                 "console": "integratedTerminal",
                 "args": [
                     "-v",
                     "AllPlatformTests.test_always_prefer_c_compiler_for_asm",
                 ],
                 "cwd": "${workspaceFolder}",
                 "env": {
                     "MESON_UNIT_TEST_BACKEND":"xcode"
                 }
             },
         ]
     }
     

4. Now just set your brake points and debug/code :)