wsl-compile-commands-converter

TLDR

Use convert.py Python script to convert compile_commands.json with Windows paths to use Windows Subsystem for Linux (WSL) compatible paths. This enables tools on WSL side to provide autofill and compiling error messages using Windows side executables. Personally using this when running Vim on WSL and editing source code which resides on Windows side.

What Is This For

When you've C/C++ project which is built by CMake. It can output a compile_commands.json file which contains all information needed to compile individual files for the project. This output file can then be read by external tool to know how to compile individual files for the project. This can for example be used by you editor to autofill functions and inform you about compiling errors.

Sometimes I'm working on the project which is develop on Windows with Windows platform tools like Visual Studio, MinGW etc. I love to use Vim for all my editing (not Visual Studio) and on Windows I'm using WSL (Windows Subsystem for Linux) to run Vim. On WSL side you can access files on Windows side so editing source files is possible with Vim. For example path C:/ can be mounted on WSL side to /mnt/c/. When project is too tightly coupled with Windows platform and cannot be compiled from WSL side even using different CMake generators. In this case Vim on WSL side have no idea of the project structure or how to compile any files, thus no autofill or error messages.

To overcome above, CMake on Windows side can generate compile_commands.json file which will contains paths in Windows format. WSL side contains tool called wslpath, which can be used to convert Windows path to WSL path. This allows tools on WSL to execute *.exe files residing on Windows side which CMake originally used as well. Thus allowing Vim for example to provide compile error messages, autofill functions names etc.

This repository contains convert.py Python script which can be feed with compile_commands.json file containing Windows paths. Script convert paths using wslpath tool and output compile_commands.json file with corrected paths.

Requirements

Tested on WSL installed Ubuntu. Tested and developed with Python 3.6. Hopefully works with later versions too. PR's are welcome if issues are found.

How To Use

Make Windows installed CMake output compile_commands.json file by providing flag -DCMAKE_EXPORT_COMPILE_COMMANDS=1 on command line or edit CMakeLists.txt to contain line set(CMAKE_EXPORT_COMPILE_COMMANDS ON). After that CMake will output file in somewhere in it's subdirectories in the build folder.

After this on WSL side symlink this project's convert.py file to your project root where you want to use it or hard code the path to it when calling Python. It's important to know that script will write compile_commands.json to current directory where script is executed and script need to be executed on WSL side. So make sure you execute it on your project root directory. Invoke conversion with following:

python convert.py path-to-build-folder/compile_commands.json

This will output compile_commands.json file with WSL paths to current directory.

Now use your tool of choice to read newly created compile_commands.json file. For example my choice was to use Vim's plugin YouCompleteMe autocompletion engine which will automatically read compile_commands.json file from your project root. When codebase changes you need to execute Python script again. In this case you can provide Vim keybinding to do so without leaving your editor.