This PR adds support to the cmake build scripts so to allow building SDL with the Tiny C Compiler (tcc).
TinyCC supports the subset of C99 used by SDL and will complete the build once the --version-script linker flag is removed. The changes have been tested with various build configurations, including X11 and Wayland, and using tcc version 0.9.28rc 2025-10-27 mob@f4e01bfc on x86_64 Linux.
The OpenGL headers are not always implicitly available, so this improves the check by calling `find_package` and using the `OPENGL_INCLUDE_DIRS` or `OPENGL_INCLUDE_DIR` var for the `check_c_source_compiles` test.
The minimum CMake version currently set is 3.16, `OPENGL_INCLUDE_DIRS` was only added in 3.29, so the code is set to choose `OPENGL_INCLUDE_DIRS` if it exists. If the minimum CMake version is ever set to >= 3.29 this check can be removed and just the `OPENGL_INCLUDE_DIRS` variable can be chosen.
It happens fairly often that people enable X11 support but don't install the extension libraries that SDL depends on. This makes those required if not explicitly disabled, which should help prevent accidentally broken builds.
This happens to work here because we don't have anything too complex, afaik.
Rejecting strings with underscores was crucial for other things, like video
with all its X11 variables, so this can't be applied to the other subsystems.
(Also, renaming the `SDL_VIDEO_RENDER_OGL_ES2` variable might be nice, too,
but let's keep this simple for now.)
Fixes#13938.
SDL has been building on GNU/Hurd for a long time, using either drivers
based on external libraries (e.g. X11, pulseaudio, sndio, etc) or dummy
drivers. This commit introduces it explicitly as platform, so it can be
recognized, and tweaked as needed. In particular:
- introduce the SDL_PLATFORM_HURD define
- tighten/improve the platform detection in cmake, and use "Hurd" as
identifier
- return the platform name in SDL_GetPlatform()
- tweak the CFLAGS/LDFLAGS so pthreads can be used properly
- implement SDL_GetExeName(), using /proc/self/exe as provided by the
basic Linux-like procfs
- enable GLES 2 in tests (mostly for consistency with Linux)
- Use modern Xkb functions where appropriate and cleanly separate the modern and legacy paths.
- Remove the deprecated XKeycodeToKeysym function in favor of directly querying the keymap on the legacy path.
- Look up virtual modifiers by name on the Xkb path to better handle remapping (equivalent to the modifier handling under Wayland).
- Optimize keymap creation on the Xkb path to cut keymap build times and enable fast group switching (equivalent to keymap handling on Wayland).
- Enable and handle Xkb events to handle changes to the group, mapping, and modifier states. This is more reliable than using the legacy events (group changes may not arrive if the window lacks pointer focus), and better handles cases where modifiers are latched, locked, or activated externally rather than physically pressed.
xkbcommon 1.10.0 declared certain modifier names to be deprecated, and the current plan is to remove them in 1.12.0. Use the new recommended names and modifier mask retrieval function when building against version 1.10.0 and higher.
This fixes the feature detection in cases where linking the final executable would fail.
This is fine since SDL only opens these libraries using dlopen as well.
These changes enable the Logitech G29 wheel to run on hidapi with both SDL_Joystick and SDL_Haptic interfaces.
While it is already possible to use the wheel on Linux in WINE + SDL2 thanks to the in-tree evdev driver as well as new-lg4ff, these set of changes allow the G29 to be used with WINE under MacOS and FreeBSD
These wheels should also be supported, but I can only test them from G29's compat modes: G27, G25, DFGT, DFP, DFEX
Haptic and led support are ported from https://github.com/berarma/new-lg4ff
