[weston] xkbcommon library is not optional.

[Bryce Harrington]

On Tue, Oct 13, 2015 at 01:59:13PM +0200, Joaquim Duran wrote:
> Hello,
> 
> When configuring the Weston project, it is possible to disable (don't
> include) the library libxkbcommon. To compile Weston successfully,
> even if the option --disable-xkbcommon is specified, the library must
> be installed because the file src/compositor.h requires it.

Joaquim, good find.

>From the comments in configure.ac:

          AS_HELP_STRING([--disable-xkbcommon], [Disable libxkbcommon
                  support: This is only useful in environments
                  where you do not have a hardware keyboard. If
                  libxkbcommon support is disabled clients will not
                  be sent a keymap and and must know how to
                  interpret the keycode sent for any key event.]),,

So it sounds like this is a special case that is intended to work.

The header include was from commit 855028fe three years ago, while the
--disable-xkbcommon was added by 382ff46f just two years ago.  That
makes me think that your situation was simply overlooked.

If that's true, then presumably the fix would involve peppering
compositor.* and other files with tests like,

#ifdef ENABLE_XKBCOMMON
...
#endif

For example it looks like the weston_xkb_info struct would need to
either be removed or stubbed out, and users of it be disabled.  There
are also some weston calls that use xkb_keymap, xkb_rule_names,
etc. structures for params that'd need addressed.

On the face of it, seems like it could be a fair amount of work, and a
bit invasive, but maybe there's some tricks to make it simpler
(typedeffing the unsupported struct args and so on.)

Alternatively, --disable-xkbcommon could be dropped.  However I get the
sense it actually solves a real world need, and functional regression is
rarely a good idea.

Would you mind filing a bug report about this?  At the least we probably
ought to at least fix the documentation, to admit the fact if xkbcommon
still needs to be present.

Is this a situation that affects what you're working on, or just
something you noticed via analysis?  If the former, would you be open to
working on a patch to address it?

Bryce

> Some code of file src/compositor.h should only be compiled if
> xkbcommon library is enabed, but this is not the case. Here I include
> some lines from that file:
> 
> 
>     34 #include <stdbool.h>
>     35 #include <time.h>
>     36 #include <pixman.h>
>     37 #include <xkbcommon/xkbcommon.h>   <--- Always included
> 
>     450
>     451 struct weston_xkb_info {      <--- Always compiled
>     452         struct xkb_keymap *keymap;
>     453         int keymap_fd;
>     454         size_t keymap_size;
>     455         char *keymap_area;
>     456         int32_t ref_count;
>     457         xkb_mod_index_t shift_mod;
>     458         xkb_mod_index_t caps_mod;
>     459         xkb_mod_index_t ctrl_mod;
>     460         xkb_mod_index_t alt_mod;
>     461         xkb_mod_index_t mod2_mod;
>     462         xkb_mod_index_t mod3_mod;
>     463         xkb_mod_index_t super_mod;
>     464         xkb_mod_index_t mod5_mod;
>     465         xkb_led_index_t num_led;
>     466         xkb_led_index_t caps_led;
>     467         xkb_led_index_t scroll_led;
>     468 };
>     469
> 
> 
> Configuration of weston:
> 
> ./autogen.sh \
>     --disable-devdocs \
>     --disable-dbus \
>     --disable-xwayland \
>     --disable-xwayland-test \
>     --disable-x11-compositor \
>     --disable-drm-compositor \
>     --disable-wayland-compositor \
>     --disable-headless-compositor \
>     --disable-rpi-compositor \
>     --enable-fbdev-compositor \
>     --disable-rdp-compositor \
>     --disable-weston-launch \
>     --disable-wcap-tools \
>     --with-cairo=image \
>     --disable-xkbcommon \
>     --enable-clients \
>     --disable-simple-clients \
>     --disable-simple-egl-clients \
>     --build=i686-linux --host=arm-none-linux-gnueabi
> --target=arm-none-linux-gnueabi \
>     --prefix=$INSTALL_DIR --with-sysroot=${SYSROOT_DIR}
> 
> 
> Error:
> 
> gem-med at gemmed-VirtualBox:~/Logic_BSPs/Linux_3.0/src/weston$ make
> make  all-am
> make[1]: Entering directory `/home/gem-med/Logic_BSPs/Linux_3.0/src/weston'
>   CC     src/gl_renderer_la-gl-renderer.lo
> cc1: warning: include location "/usr/include/libdrm" is unsafe for
> cross-compilation [-Wpoison-system-directories]
> In file included from src/gl-renderer.h:28:0,
>                  from src/gl-renderer.c:41:
> src/compositor.h:37:33: fatal error: xkbcommon/xkbcommon.h: No such
> file or directory
> compilation terminated.
> make[1]: *** [src/gl_renderer_la-gl-renderer.lo] Error 1
> make[1]: Leaving directory `/home/gem-med/Logic_BSPs/Linux_3.0/src/weston'
> make: *** [all] Error 2
> 
> Joaquim Duran
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