[PATCH weston] configure.ac: make use of wayland-scanner.pc

[Bill Spitzak]

This sounds good to me. Thanks for running the test, I got swamped with 
other stuff and could not get to it.

I think the reason it does not fail is that the output of 
wayland-scanner is in the git repository and therefore it does not need 
to be run the first time. I suppose it would fail if somebody altered 
the xml file before the first build, but I'm not sure if that is a big 
problem.

On 02/23/2015 05:53 PM, Bryce Harrington wrote:
> On Mon, Feb 23, 2015 at 11:11:36PM +0000, Emil Velikov wrote:
>> On 23 February 2015 at 22:32, Bill Spitzak <spitzak at gmail.com> wrote:
>>> wayland-scanner is built as part of "make" in wayland. However it is also
>>> used to convert the xml descriptions to .c and .h files, which are also used
>>> by "make".
>>>
>>> In some early versions of Wayland this would never work for a new user. It
>>> would not find wayland-scanner and fail, so "make install" never worked and
>>> you could not get things working without doing a manual step of copying the
>>> wayland-scanner executable to the path.
>>>
>>> A big annoyance is that once you get wayland to install, this never happens
>>> again, leading the developers to not notice if it breaks.
>>>
>>> A related annoyance is that editing the source for wayland scanner should
>>> cause the .h/.C files to be regenerated using the new version and used to
>>> compile the rest of wayland and weston. This can make it easy to not realize
>>> a bug was introduced into wayland scanner.
>>>
>> So to sum it all up (see if I got it correct):
>>   - Wayland (as opposed to weston) issue
>>   - During a wayland build, there is a dependency of wayland-scanner.
>>   - One can manually work around the problem by copying wayland-scanner.
>>   - The dependencies are still not honoured and wayland-scanner never
>> gets rebuild and/or reused(reinstalled).
>>
>> I would assume that removing wayland{,-scanner} and tracking down the
>> dependency sounds like a bit of a pain :-)
>
> Shouldn't it be sufficient to just move wayland-scanner out of your path?
>
> I deleted or moved aside all wayland-scanner binaries, so 'which
> wayland-scanner' returned nothing.  Then 'make distclean' in my wayland
> tree.  This should replicate Bill's wayland newbie's environment.
>
> Now:
>
> $ ./autogen.sh --prefix=$WLD 2>&1 | grep scanner
>    config.status: creating src/wayland-scanner-uninstalled.pc
>    config.status: creating src/wayland-scanner.pc
>
> $ cat src/wayland-scanner-uninstalled.pc
>    pkgdatadir=/home/bryce/build/Wayland/wayland
>    wayland_scanner=/home/bryce/build/Wayland/wayland/src/wayland-scanner
>
>    Name: Wayland Scanner
>    Description: Wayland scanner (not installed)
>    Version: 1.7.90
>
> $ cat src/wayland-scanner.pc
>    prefix=/home/bryce/build/Wayland/install
>    exec_prefix=${prefix}
>    datarootdir=${prefix}/share
>    pkgdatadir=${datarootdir}/wayland
>    wayland_scanner=${exec_prefix}/bin/wayland-scanner
>
>    Name: Wayland Scanner
>    Description: Wayland scanner
>    Version: 1.7.90
>
> $ which wayland-scanner
>
> $ ls /usr/local/bin/*scanner*
>
> $ make 2>&1 | grep wayland-scanner
>    CCLD     wayland-scanner
>
> $ make install 2>&1 | grep scanner
>    /bin/bash ./libtool   --mode=install /usr/bin/install -c wayland-scanner '/home/bryce/build/Wayland/install/bin'
> libtool: install: /usr/bin/install -c wayland-scanner /home/bryce/build/Wayland/install/bin/wayland-scanner
>   /usr/bin/install -c -m 644 wayland-scanner.m4 '/home/bryce/build/Wayland/install/share/aclocal'
>   /usr/bin/install -c -m 644 wayland-scanner.mk protocol/wayland.xml protocol/wayland.dtd '/home/bryce/build/Wayland/install/share/wayland'
>   /usr/bin/install -c -m 644 src/wayland-client.pc src/wayland-server.pc src/wayland-scanner.pc cursor/wayland-cursor.pc '/home/bryce/build/Wayland/install/lib/pkgconfig'
>
>
> So...  Everything appears to be hanging together just fine.  I'm
> gathering that when wayland-scanner isn't found on the path it's using
> the locally built binary instead?
>
>>> My proposed test, with a --prefix to an install directory:
>>>
>>> 1. clear out the install directory
>>> 2. make sure "wayland-scanner" does not exist on the machine
>>> 3. go into wayland and type "make install"
>>>
>>> Another test I would like to do is:
>>>
>>> 1. Edit wayland-scanner to put an obvious typo into the .h file
>>> 2. Run "make" and insure that it fails.
>>>
>> Sounds like you might want to have a OBS(-like) [1] solution which
>> does a clean [2] build of wayland.
>
> As it happens, I set such a thing up a few months back via Launchpad[3],
> to create a daily-builds PPA for ubuntu[4].  During this time it's been
> building successfully.
>
>> No disrespect but isn't all this somewhat orthogonal to what I'm
>> proposing/fixing, or did it just remind you of the problem ?
>
> It's maybe a bit orthogonal but better to ask too many questions than
> not enough.  Plus I wondered the same as Bill about it.
>
>> Thanks for the comprehensive explanation Bill :-)
>> Emil
>
> Bryce
>
>> [1] http://openbuildservice.org/
>> [2] Create a VM/container with the bare dependencies, with which one
>> builds the package.
>
> [3] https://code.launchpad.net/~wayland.admin/+recipe/wayland-daily
> [4] https://launchpad.net/~wayland.admin/+archive/ubuntu/daily-builds
>