Stop trying to maintain a per-file _POSIX_C_SOURCE. Instead,
require POSIX.1-2008 globally. A lot of core source files depend
on that already.
Some care must be taken on a few select files where we need a bit
more than POSIX. Some files need XSI extensions (_XOPEN_SOURCE) and
some files need BSD extensions (_DEFAULT_SOURCE). In both cases,
these feature test macros imply _POSIX_C_SOURCE. Make sure to not
define both these macros and _POSIX_C_SOURCE explicitly to avoid
POSIX requirement conflicts (e.g. _POSIX_C_SOURCE says POSIX.1-2001
but _XOPEN_SOURCE says POSIX.1-2008).
Additionally, there is one special case in render/vulkan/vulkan.c.
That file needs major()/minor(), and these are system-specific.
On FreeBSD, _POSIX_C_SOURCE hides system-specific symbols so we need
to make sure it's not defined for this file. On Linux, we can
explicitly include <sys/sysmacros.h> and ensure that apart from
symbols defined there the file only uses POSIX toys.
Since we only use the backend capabilities here we can simply pass
them in directly. This allows other locations to create an allocator
even if they don't have a backend. They can simply specify the caps
they want instead.
Replace them with wlr_signal_emit_safe, which correctly handles
cases where a listener removes another listener.
Reported-by: Isaac Freund <ifreund@ifreund.xyz>
Now that the DRM backend no longer depends on GBM, we can make it
optional. The GLES2 renderer still depends on it because of our EGL
device selection.
This is useful for compositors with their own renderers, and for
compositors using the Vulkan renderer.
If the backend doesn't have a DRM FD, fallback to the renderer's.
This accomodates for the situation where the headless backend hasn't
picked a DRM FD in particular, but the renderer has picked one.
If we aren't trying to create a dumb buffer allocator, and if the
DRM device has a render node (ie, not a split render/display SoC),
then we can use the render node instead of the primary node. This
should allow wlroots to run under seatd when the current user
doesn't have the permission to open primary nodes (logind has a
quirk to allow physically logged in users to open primary nodes).
