pwbh/zig_test_debugging_vscode.md

Forked from floooh/zig_test_debugging_vscode.md

Created September 2, 2024 16:41

Star () You must be signed in to star a gist
Fork () You must be signed in to fork a gist

Learn more about clone URLs
Clone this repository at <script src="https://gist.github.com/pwbh/883d9aff7cdffceb2c110f1df5c2aedf.js"></script>
Save pwbh/883d9aff7cdffceb2c110f1df5c2aedf to your computer and use it in GitHub Desktop.

Download ZIP

How to debug Zig tests in VSCode

Raw

zig_test_debugging_vscode.md

Tested on macOS:

Install the CodeLLDB VSCode extension. Unlike the debugger in the C/C++ extension, this allows to set breakpoints inside Zig "test" blocks (in the MS C/C++ extension debugger, breakpoints inside test blocks will be disabled once the debugger starts for unknown reasons.
When compiling the test, tell it to also emit a binary: zig test -femit-bin=zig-out/bin/my-test src/bla.zig, otherwise there will be no executable to debug.
The compiled test executable expects the path to the Zig executable as first command line argument, the launch.json file needs to be setup accordingly (note the args item):

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug",
            "program": "${workspaceFolder}/zig-out/bin/my-test",
            "args": ["/usr/local/bin/zig"],
            "cwd": "${workspaceFolder}",
            
        }
    ]
}

That should be all, now set breakpoints inside tests and start the debugger with F5.

Author

pwbh commented Sep 2, 2024

My current setup is a combination of the VSCode Zig extension (https://marketplace.visualstudio.com/items?itemName=ziglang.vscode-zig) and CodeLLDB with the following vanilla launch.json:
{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "lldb",
            "request": "launch",
            "name": "Debug",
            "program": "${workspaceFolder}/zig-out/bin/kc853",
            "args": [],
            "cwd": "${workspaceFolder}"
        }
    ]
}
Debugging and breakpoints work (on macOS). Only bug I see is a debug line mismatch at the end of scope blocks. Sometimes the debugger appears to step through or stop at the last line of an if-else else branch even though that else branch isn't taken.

For tests I simply install them as artifact, so that an executable file is created in the file system, and simply build them during zig build:

https://github.com/floooh/chipz/blob/8dd374eb1e5605e1f86f0d3cd7206e8ddf1f29a5/tests/build.zig#L37-L56