| # Building and using `gn` with MinGW on Windows |
| At the time of writing: 2024-04-13 |
| Test environment: Windows 11, intel x86_64 CPU |
| 1. Install [MSYS2](https://www.msys2.org/) |
| 1. Start a Terminal windows for MSYS2's MinGW development by opening one of `clang32.exe`, `clang64.exe`, `clangarm64.exe`,`mingw32.exe`, `mingw64.exe`, `ucrt64.exe`. |
| 1. To download clang toolchain, Ninja and git programs, run command: `pacman -S mingw-w64-clang-x86_64-toolchain mingw-w64-clang-x86_64-ninja git` |
| 1. To clone `gn` source code, run command: `git clone https://gn.googlesource.com/gn` |
| 1. Run command: `build/gen.py --platform mingw` |
| This configuration generates a static executable that does not depend on MSYS2, and can be run in any development environment. |
| Use `--help` flag to check more configuration options. |
| Use `--allow-warning` flag to build with warnings. |
| 1. Run command: `ninja -C out` |
| 1. Run command: `out/gn --version` |
| 1. Run command: `out/gn_unittests` |
| > For "mingw-w64-clang-x86_64-toolchain" in the clang64 environment, g++ is a copy of clang++. |
| > The toolchain that builds `gn` does not use vendor lock-in compiler command flags, |
| > so `gn` can be built with these clang++, g++. |
| > However the build rules in [examples/simple_build](../examples/simple_build/) require GCC-specific compiler macros, and thus only work in the `ucrt64` MSYS2 development environment. |
