dependency and option in meson project - meson-build

Question

I have a project with a similar folder trees:
├── meson.build (1)
├── meson_options.txt
├── README.md
└── src
└── mysub
├── meson.build (2)
└── mesonTest.c
the meson.options.txt contains
option('avx_opt', type : 'combo', choices : ['avx2', 'avx512'], value : 'avx512')
the mysub project is a dependency of the main proj
so the meson.build (1) :
project(
'my_proj',
'c',
version : '1.1.0',
default_options : ['buildtype=plain','warning_level=3'],
subproject_dir : 'src'
)
project_source_files = [
''
]
message('## source root : ' + meson.project_source_root() + ' ##')
project_dependencies = [
dependency('mysub', fallback : ['mysub', 'mysub_dep']),
]
build_args = [
]
# ===================================================================
# ======
# Target
# ======
build_args += [
'-DPROJECT_NAME=' + meson.project_name(),
'-DPROJECT_VERSION=' + meson.project_version(),
]
the meson.build (2) of the mysub proj is:
project(
'mysub',
'c',
version : '1.1.0',
default_options : ['warning_level=3']
)
project_description = 'mysub binary'
project_source_files = [
'mesonTest.c'
]
project_headers = [
]
avx_type = get_option('avx_opt')
if (avx_type == 'avx512')
build_args_avx512 = [
'-mavx512f',
'-mavx512cd',
'-mavx512vl',
'-mavx512bw',
'-mavx512dq',
'-DNEWLDPC=1'
]
else
build_args_avx512 = [
'-DNEWLDPC=0'
]
endif
project_target = executable(
meson.project_name(),
project_source_files,
install : true,
c_args : build_args,
link_args : '-Wl,--allow-shlib-undefined',
)
# =======
# Project
# =======
# Make this library usable as a Meson subproject.
project_dep = declare_dependency(
include_directories: public_headers,
link_with : project_target
)
set_variable(meson.project_name() + '_dep', project_dep)
# Make this library usable from the system's
# package manager.
install_headers(project_headers, subdir : meson.project_name())
pkg_mod = import('pkgconfig')
pkg_mod.generate(
name : meson.project_name(),
filebase : meson.project_name(),
description : project_description,
subdirs : meson.project_name(),
# libraries : project_target,
)
I have tried to configure in the following way:
meson builddir -Davx_opt=avx512
or
meson builddir -Davx_opt:mysub=avx512
but in both case I got:
The Meson build system
Version: 0.59.1
Source dir: /home/roccasal/wsEclipse/Intel/mesonTest/proj
Build dir: /home/roccasal/wsEclipse/Intel/mesonTest/proj/builddir
Build type: native build
Project name: my_proj
Project version: 1.1.0
C compiler for the host machine: cc (gcc 8.5.0 "cc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4)")
C linker for the host machine: cc ld.bfd 2.30-108
Host machine cpu family: x86_64
Host machine cpu: x86_64
Message: ## source root : /home/roccasal/wsEclipse/Intel/mesonTest/proj ##
Found pkg-config: /usr/bin/pkg-config (1.4.2)
Found CMake: /usr/bin/cmake (3.20.2)
Run-time dependency mysub found: NO (tried pkgconfig and cmake)
Looking for a fallback subproject for the dependency mysub
Executing subproject mysub
mysub| Project name: mysub
mysub| Project version: 1.1.0
mysub| C compiler for the host machine: cc (gcc 8.5.0 "cc (GCC) 8.5.0 20210514 (Red Hat 8.5.0-4)")
mysub| C linker for the host machine: cc ld.bfd 2.30-108
src/mysub/meson.build:32:0: ERROR: Tried to access unknown option "avx_opt".
what is wrong in the meson build configuration?
the meson ver used is 0.59.1
//thanks

Answer 1

Check Build-options page in reference manual:
To change values in subprojects prepend the name of the subproject and
a colon:
$ meson configure -Dsubproject:option=newvalue
Thus, try create new build dir with:
meson builddir -Dmysub:avx_opt=avx512
or configure existing with:
meson configure builddir -Dmysub:avx_opt=avx512
To make it working you also need this option defined in meson_options.txt in every subproject that uses it, but to simplify configuration you can as #dcbaker suggested use yielding, i.e. update option definition for the main project:
option('avx_opt', ...., yield : true)
This will give you possibility to configure it the same way for main and subprojects with just:
meson configure builddir -Davx_opt=avx512
Also, (I guess it's just typo in question) file with options should have name meson_options.txt (with underscore).