kc3-lang/SDL

2022-10-31T12:05:36

sdl2-config.in: Deprecate sdl2-config Library-specific foo-config scripts duplicate very similar logic across various different projects, and tend to break cross-compiling, multilib (gcc -m32), Debian/Ubuntu multiarch and so on by only being able to have one sdl2-config at a time as the first one in the PATH. The direct replacement is pkg-config(1) or a compatible reimplementation like pkgconf(1), which relies on each library installing declarative metadata, like SDL's sdl2.pc (available since at least 2.0.0) and centralizes the logic into the pkg-config/pkgconf tool. Most uses of `sdl2-config --foo` can be replaced by something similar to `${PKG_CONFIG:-pkg-config} --foo sdl2`. Instead of adding a custom sdl2-config to the PATH or using its --prefix or --exec-prefix options, users of a custom installation prefix can use any of pkg-config's non-SDL-specific ways to influence the result, for example setting PKG_CONFIG_PATH, PKG_CONFIG_SYSROOT_DIR or PKG_CONFIG_LIBDIR environment variables, or setting the PKG_CONFIG environment variable to point to a wrapper script. For Autotools specifically, the replacement for AM_PATH_SDL2 (which will be officially deprecated in a subsequent commit) is PKG_CHECK_MODULES. CMake has its own semi-declarative mechanism for dependency discovery, "config packages", and the SDL build already installs a config package. There's a good example of using a config package to discover SDL in `cmake/test/`. Meson natively supports pkg-config, and already uses it in preference to sdl2-config. Other build systems can run pkg-config instead of sdl2-config, preferably checking the PKG_CONFIG environment variable first. https://github.com/ioquake/ioq3 is a good example of a project doing this correctly. Helps: #6140, #3516 Signed-off-by: Simon McVittie <smcv@collabora.com>