envconfig: add pkg_config_libdir property

[dabrain34]

In order to unify the use of sysroot in the cross-file,
the pkg_config_path can now be passed directly in the file.

[xclaesse]

For cross compilation, it's not PKG_CONFIG_PATH you need to set, but PKG_CONFIG_LIBDIR. The difference is the former is in addition to system paths, the latter is instead of system paths.

pkg-config doc recommends using this wrapper for cross compilation, I think Meson should set the same env vars using the cross file.

#!/bin/sh

SYSROOT=/build/root

export PKG_CONFIG_DIR=
export PKG_CONFIG_LIBDIR=${SYSROOT}/usr/lib/pkgconfig:${SYSROOT}/usr/share/pkgconfig
export PKG_CONFIG_SYSROOT_DIR=${SYSROOT}

exec pkg-config "$@"```

[xclaesse]

Implementation looks good to me. It's missing doc (grep for pkg_config_path to add at the same place), release notes, and unit test ( similar to run_unittest.py's test_cross_pkg_config_option() probably).

[xclaesse]

What the test could do:

• dependency('zlib', method : 'pkg-config', native : false) should return the system version
• dependency('zlib', method : 'pkg-config', native : true) should return the cross version, write a dummy zlib.pc in a subdir of the test project and set libdir there, you can verify it's your dummy version by checking the version.

Thinking more about it, I think if pkg_config_libdir is not set in the cross file and PKG_CONFIG_LIBDIR has not been set by the user in the environment, we should set it to empty "" when searching for cross dependencies. Otherwise it will lookup for system dependencies and that's never the right thing to do. Or we should at least warn and tell user to set pkg_config_libdir.

[dabrain34]

What the test could do:

* dependency('zlib', method : 'pkg-config', native : false) should return the system version

* dependency('zlib', method : 'pkg-config', native : true) should return the cross version, write a dummy zlib.pc in a subdir of the test project and set libdir there, you can verify it's your dummy version by checking the version.

Thx for the recommandation, I'll try to implement something like that. Is there a simple way to run a single unit test from CLI ?

Thinking more about it, I think if pkg_config_libdir is not set in the cross file and PKG_CONFIG_LIBDIR has not been set by the user in the environment, we should set it to empty "" when searching for cross dependencies. Otherwise it will lookup for system dependencies and that's never the right thing to do. Or we should at least warn and tell user to set pkg_config_libdir.

Yes I agree, we should warn some how the user.

[xclaesse]

Is there a simple way to run a single unit test from CLI ?

./run_unittests.py TheTestClass.test_function

[dcbaker]

I think there's a bug in your code if pkg_config_libdir is a string and not a list. I think it would be best if internally we always represented this as a list of strings or None.

[xclaesse]

@dabrain34 Oops, I just realised that test_native_dep_pkgconfig() does exactly what you want already. You can reuse the same unit test and just add a case where it generate a cross file with pkgconfig='pkg-config' (instead of cross_pkgconfig.py) and set pkg_config_libdir.

[dcbaker]

Code looks good, thanks for making changes.

You do need some documentation as @xclaesse said. You'll need a release snippet and to update the general docs.

[dabrain34]

Code looks good, thanks for making changes.

You do need some documentation as @xclaesse said. You'll need a release snippet and to update the general docs.

Can you give me more details if I have something special to perform here. I think I already updated the documentation.

[xclaesse]

Code looks good, thanks for making changes.
You do need some documentation as @xclaesse said. You'll need a release snippet and to update the general docs.

Can you give me more details if I have something special to perform here. I think I already updated the documentation.

The doc is fine, but it's missing a release notes snippet. Add a file into docs/markdown/snippets/

[xclaesse]

almost there, just small nitpickings. Thanks for your work :D

[xclaesse]

unit tests are failing, it seems unrelated, but that needs to be checked too :/

[xclaesse]

Looks all good to me now, when CI is green.

[xclaesse]

LGTM when CI is green.

For the record, we had to drop the change that uses os.pathsep instead of ':' because it causes CI to fail for obscure reasons. Since it requires more work and is unrelated to this PR, better do it separately.

[keven2116]

Hi,

This feature is not working on the meson 0.53.2, right?

Best Regards,
Wen

[dabrain34]

AFAIK its only in master and planned to be release in 0.54

If you need it, its quite easy to use meson as you checkout the master branch of this repo and make alias to meson.py in this repo.

alias meson=/home/user/DEV/meson/meson.py