[Mesa-dev] [PATCH] configure.ac: Add --with-wayland-scanner-path

[Emil Velikov]

On 29 May 2017 at 14:05, Jussi Kukkonen <jussi.kukkonen at intel.com> wrote:
> On 29 May 2017 at 15:20, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>>
>> On 26 May 2017 at 14:55, Jussi Kukkonen <jussi.kukkonen at intel.com> wrote:
>> > On 26 May 2017 at 14:32, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>> >>
>> >> On 26 May 2017 at 08:52, Jussi Kukkonen <jussi.kukkonen at intel.com>
>> >> wrote:
>> >> >
>> >> >
>> >> > On 24 May 2017 at 16:39, Emil Velikov <emil.l.velikov at gmail.com>
>> >> > wrote:
>> >> AFAICT there are a couple of alternative solutions - have you
>> >> considered/tried any of them?
>> >>
>> >> a) w/o a wrapper script
>> >> $ export PKG_CONFIG_PATH= // you need this if using the system
>> >> pkgo-config. if the local/native one is used, this should be optional
>> >> $ export
>> >>
>> >> PKG_CONFIG_LIBDIR=$path_to_non_system_host_pkgconfig:${SYSROOT}/usr/{lib,share}/pkgconfig
>> >> $ export PKG_CONFIG_SYSROOT_DIR=${SYSROOT}
>> >
>> > We're using a natively built pkg-config which sets all the pkg-config
>> > variables to what I believe are the correct values: the problem is that
>> > none
>> > of those variable is for the _native_ sysroot location so they don't
>> > help in
>> > this case. There is now way to say in a .pc file that this path should
>> > be
>> > prefixed with something like  "${pc_native_sysroot_dir}" if it's
>> > defined.
>> >
>> >> b) with a wrapper script - see [1].
>> >> I think that the "export PKG_CONFIG_DIR=" is a typo (should be ..PATH
>> >> instead) and is not strictly required - feel free to check either way.
>> >> Note that the exec at the end might need to be amended to
>> >> /path/to/$(CHOST)-pkg-config.
>> >
>> > We don't provide a target wrapper -- I believe because it provides no
>> > value
>> > at all on top of the setup we have (the pkg-config that autotools finds
>> > has
>> > all the environment variables set correctly. It is essentially
>> > $(CHOST)-pkg-config already).
>> >
>> > If I've missed something, I'd be happy to hear that. At the moment I
>> > think
>> > pkg-config just does not help in this case.
>> >
>> I'm confused a bit - did you try the above suggestions? If so can you
>> share which one and how it fails?
>
>
> I'm sorry but I do not see what I could test that could help: I mentioned
> that the pkg-config that gets used by PKG_CHECK_MODULES() is essentially a
> wrapped one: In more detail the build tool sets these variables:
>
Giving it a try won't hurt, right ;-)

But on a more serious note:
[1] Like any project in the wild Yocto might have bugs, please try w/o it.
[2] A simple test [w/o Yocto] with my earlier suggestion seems to work fine

Thanks
Emil

[1] From a quick look Yocto seems to be doing things a bit strange, wrong even?
This is the first time I'm looking through it, so I may be wrong.

Some examples, with the first and foremost being the prime suspect why
things don't work as expected.
* Yocto uses PKG_CONFIG_DIR. The variable is not a thing used by
pkg-config (or pkgconf).
Yes sometimes it's used only to be fed into LIBDIR/PATH
(meta/conf/bitbake.conf), but it does not seem consistent.
IMHO a good first step would be is to drop or rename it to PATH.

* The native pkg-config has correct PATH/LIBDIR burned into the binary
* A pkg-config-native wrapper also sets the PATH/LIBDIR variables
 - those are the default already stored within the binary
 - SYSROOT_DIR is explicitly discarded
* Any PKG_CHECK_MODULES(.*) calls are discarded(??) - see wayland_1.11.0.bb

[2] The following seems to work based on a quick test.

-- Layout

/usr/bin/{pkg-config,wayland-scanner}
/usr/lib/pkgconfig/wayland-scanner.pc

/native/usr/bin/{pkg-config,wayland-scanner}
/native/usr/lib/pkgconfig/wayland-scanner.pc

/target/usr/bin/{pkg-config,wayland-scanner} // just an example, one
or both can be missing
/target/usr/lib/pkgconfig/wayland-scanner.pc

-- cat $(CHOST)-pkg-config
#!/bin/sh

export SYSROOT=/target/
export PKG_CONFIG_LIBDIR=/native/usr/lib/pkgconfig/:${SYSROOT}/usr/lib/pkgconfig
export PKG_CONFIG_SYSROOT_DIR=${SYSROOT}

/native/usr/bin/pkg-config "$@"