Using a custom VAPI does not generate a -pkg foo flag

[wblaszcz]

The current 'Using a custom VAPI' (with pkg-config file) example on the wiki does not work for me.
I need to explicitly add a --pkg=foo to the executable line. I can only assume that this is a bug?
e.g.
change

add_project_arguments(['--vapidir', join_paths(meson.current_source_dir(), 'vapi')], 
                      language: 'vala')
                      
glib_dep = dependency('glib-2.0')
gobject_dep = dependency('gobject-2.0')
foo_dep = dependency('foo') # 'foo.vapi' will be resolved in './vapi/foo.vapi'

executable('app', 'app.vala', dependencies: [glib_dep, gobject_dep, foo_dep])

to

add_project_arguments(['--vapidir', join_paths(meson.current_source_dir(), 'vapi')], 
                      language: 'vala')
                      
glib_dep = dependency('glib-2.0')
gobject_dep = dependency('gobject-2.0')
foo_dep = dependency('foo') # 'foo.vapi' will be resolved in './vapi/foo.vapi'

executable('app', 'app.vala', dependencies: [glib_dep, gobject_dep, foo_dep], vala_args: ['--pkg=foo'])

BTW, on the 'Using a custom VAPI' (with no pkg-config file) example, the foo_vapi line is missing a closing parentheses.

[arteymix]

The example assumes that there's a pkg-config file named foo.pc. I've tested it with libuv and it works as expected.

Could you provide a failing sample?

[wblaszcz]

The follow is my meson.build file:

project('model3d', 'vala', 'c')

add_project_arguments(['--vapidir', join_paths(meson.current_source_dir(), 'vapi')],
        language: 'vala')

m_dep = meson.get_compiler('c').find_library('m', required : false)
glib_dep = dependency('glib-2.0')
gobject_dep = dependency('gobject-2.0')
gl_dep = dependency('gl')
sdl2_dep = dependency('sdl2')

executable('model3d', ['src/model3d.vala', 'src/vector.vala'],
        dependencies : [m_dep, glib_dep, gobject_dep, gl_dep, sdl2_dep])

The vapi directory contains the gl.vapi and sdl2.vapi files.
The following files are located on my system.
/usr/lib/pkgconfig/gl.pc
/usr/lib/pkgconfig/sdl2.pc

The following is the output of meson build:

The Meson build system
Version: 0.41.1
Source dir: /home/wblaszcz/MyVala/model3d
Build dir: /home/wblaszcz/MyVala/model3d/build
Build type: native build
Project name: model3d
Native c compiler: cc (gcc 6.3.0)
Native vala compiler: valac (valac 0.36.1)
Build machine cpu family: x86_64
Build machine cpu: x86_64
Library m found: YES
Found pkg-config: /usr/bin/pkg-config (0.29.1)
Native dependency glib-2.0 found: YES 2.52.1
Native dependency gobject-2.0 found: YES 2.52.1
Native dependency gl found: YES 17.0.3
Native dependency sdl2 found: YES 2.0.5
Build targets in project: 1

The following is the output of ninja:

[1/4] Compiling Vala source ../src/model3d.vala ../src/vector.vala.
FAILED: model3d@exe/model3d.c model3d@exe/vector.c 
valac -C --debug --vapidir /home/wblaszcz/MyVala/model3d/vapi --pkg gobject-2.0 --pkg glib-2.0 -d model3d@exe ../src/model3d.vala ../src/vector.vala
../src/model3d.vala:1.7-1.8: error: The namespace name `GL' could not be found
using GL;
      ^^
../src/model3d.vala:2.7-2.9: error: The namespace name `SDL' could not be found
using SDL;
      ^^^
../src/model3d.vala:5.22-5.26: error: The symbol `Video' could not be found
    protected static Video.Window window;
...

As you can see, the valac line does not contain the --pkg=gl --pkg=sdl2 flags.
If I add vala_args : ['--pkg=gl', '--pkg=sdl2'] to the executable line, ninja builds successfully.
I think it is due to the fact that both these libraries are in uppercase? (-lGL and -lSDL2)
I've just tried adding libcurl as a dependency, I that worked fine, e.g.:

[1/4] Compiling Vala source ../src/model3d.vala ../src/vector.vala.
FAILED: model3d@exe/model3d.c model3d@exe/vector.c 
valac -C --debug --vapidir /home/wblaszcz/MyVala/model3d/vapi --pkg libcurl --pkg gobject-2.0 --pkg glib-2.0 -d model3d@exe ../src/model3d.vala ../src/vector.vala
../src/model3d.vala:1.7-1.8: error: The namespace name `GL' could not be found
using GL;
      ^^

[arteymix]

It's definately a bug, both sdl2 and gl are treated with a specific dependency objects and --pkg are only emitted for PkgConfigDependecy objects.

[hrxi]

I'm also affected by this bug, hitting this while trying to port Dino to Windows.

Workaround for vapi files shipped with Vala:

dep_gtk4 = [dep_gtk4, meson.get_compiler('vala').find_library('gtk4')]

General workaround:

executable(sources, vala_args: ['--pkg', 'icu-uc'], dependencies: dependencies)

[v1993]

This is probably caused by

meson/mesonbuild/backend/backends.py

Lines 1057 to 1067 in 39ecfc2

	if compiler.language == 'vala':
	if dep.type_name == 'pkgconfig':
	assert isinstance(dep, dependencies.ExternalDependency)
	if dep.name == 'glib-2.0' and dep.version_reqs is not None:
	for req in dep.version_reqs:
	if req.startswith(('>=', '==')):
	commands += ['--target-glib', req[2:]]
	break
	commands += ['--pkg', dep.name]
	elif isinstance(dep, dependencies.ExternalLibrary):
	commands += dep.get_link_args('vala')

Line 1058 probably should be replaced with if isinstance(dep, dependencies.ExternalDependency): and elif block removed completely.

Edit: an extra check in form of and (dep.language is None or dep.language == 'vala') may also be needed; I have not checked.

[hrxi]

I agree.