[waffle] [PATCH 04/10] cmake: add autodetection for waffle_has_egl, glx...

[Emil Velikov]

On 06/06/14 07:18, Chad Versace wrote:
> On Sat, May 31, 2014 at 03:22:02AM +0100, Emil Velikov wrote:
>> Silence the pkg_check_modules and check set the default
>> options depending on the packages found.
> 
> This is a good idea and will make Waffle easier to configure for
> everyone.
> 
> There are a few problems though.
> 
> If configuration fails because the user tried to enable a platform for
> which his system lacks the dependencies, then post-patch CMake no longer
> gives sufficient explanation why it failed. For example, if
> -Dwaffle_has_gbm=1 fails, CMake informs the user thta "gbm requirements
> are not met" but does explain what those requirements are. And, since
> waffle_pkg_config is now silenced by QUIET, CMake's earlier output
> provides no clue.
> 
> To avoid providing the user a silent mystery, this block
> 
>> +    if(waffle_has_wayland)
>> +        if(NOT wayland-client_FOUND OR
>> +           NOT wayland-egl_FOUND OR NOT egl_FOUND)
>> +            message(FATAL_ERROR "wayland requirements are not met.")
>> +        endif()
>> +    endif()
> 
> should explain which requirements, including the version if any, were
> not met.  For example, if -Dwaffle_has_wayland=1 but the system lacks
> wayland-egl>=9.1, then CMake should print something like
>     "wayland dependency is missing: wayland-egl>=9.1"
> or
>     "wayland requirement wayland-egl>=9.1 is not met"
> 
This would add a few extra lines, although it would be very nice to have.

> 
> Why did you decide to silece waffle_pkg_config with QUIET? I feel that
> it's useful to get notification for each item that CMake probes for.
> 
Was under the impression that when REQUIRED|QUIET is missing cmake defaults to
the former, which errors out when the package is missing. Seems like I got
confused with another cmake command.

Updated patch will follow shortly.

-Emil