use static library of subproject

[andy5995]

In one of my subprobjects, I have

buildtarget = both_libraries(
  meson.project_name(),
  src,
  include_directories : inc,
  version : meson.project_version(),
  soversion : '0',
  install: true)

dep_canfigger = declare_dependency(include_directories : inc,
  link_with : buildtarget)

In the superproject, I have

canfigger_proj = subproject('canfigger')
dep_canfigger = canfigger_proj.get_variable('dep_canfigger')

which works, but I want to link to the static library instead of shared. How can I alter the "static" element of the dep_canfigger object returned by canfigger_proj.get_variable('dep_canfigger') so it will be 'true'?

In the subproject, I had

dep_canfigger_static = declare_dependency(include_directories : inc,
  link_with : buildtarget.get_static_lib())
dep_canfigger_shared = declare_dependency(include_directories : inc,
  link_with : buildtarget.get_shared_lib())

then in the superproject, I used

dep_canfigger_static = canfigger_proj.get_variable('dep_canfigger_static')

but I'm thinking there's a better way...

UPDATE:

I've changed

canfigger_proj = subproject('canfigger')
dep_canfigger = canfigger_proj.get_variable('dep_canfigger')

to

dep_canfigger = dependency(
  'canfigger',
  fallback : ['canfigger', 'dep_canfigger_static']
  )

I still want it to statically link when using the fallback.

Using this in the subproject (canfigger library meson.build)

dep_canfigger_static = declare_dependency(include_directories : inc,
  link_with : buildtarget.get_static_lib())
dep_canfigger_shared = declare_dependency(include_directories : inc,
  link_with : buildtarget.get_shared_lib())

isn't so terrible, but I just wanted to check if there's a more efficient way of doing it.

[eli-schwartz]

Is there any particular reason to use both_libraries() to build both static and shared, rather than using library() and letting the person building the project choose which one(s) they want by configuring with -Ddefault_library={static|shared|both}?

You can also configure it on a per subproject level using -Dcanfigger:default_library=static or by passing default_options: ['default_library=static'] as a kwarg to the subproject/dependency invocation.

(Also you can add "both" as a default_options in the project() definition of canfigger.)

[andy5995]

Now when I try to init the superproject builddir, I get this "unknown method" error.

Correction/clarification... when I init with:

meson builddir -Dcanfigger:default_library=static

[eli-schwartz]

Now when I try to init the superproject builddir, I get this "unknown method" error.

Makes sense. get_shared_lib is only useful or valid for a both_libraries(), and in fact I question the value of get_shared_lib there either since using the result is basically identical to using the both_libraries object anyway.

You cannot guarantee get_shared_lib() will succeed if -Ddefault_library=static is used, but in that case the user determined to have a preferred link model of linking statically, so it is all good...

[andy5995]

But then nothing works...

[andy@prometheus rmw]$ cd builddir/
[andy@prometheus builddir]$ ls
config.h  meson-info  meson-logs  meson-private  meson-uninstalled  po  subprojects
[andy@prometheus builddir]$ ninja
ninja: error: loading 'build.ninja': No such file or directory
[andy@prometheus builddir]$ meson compile
Traceback (most recent call last):
  File "/usr/lib/python3.10/site-packages/mesonbuild/mesonmain.py", line 138, in run
    return options.run_func(options)
  File "/usr/lib/python3.10/site-packages/mesonbuild/mcompile.py", line 324, in run
    cdata = coredata.load(options.wd)
  File "/usr/lib/python3.10/site-packages/mesonbuild/coredata.py", line 1030, in load
    with open(filename, 'rb') as f:
FileNotFoundError: [Errno 2] No such file or directory: '/home/andy/src/rmw-project/rmw/builddir/meson-private/coredata.dat'

[eli-schwartz]

Of course if meson setup builddir <options> fails then ninja won't work either.

The error nevertheless makes sense -- libfoo.get_shared_lib() assumes you use both_libraries, but you might as well just use libfoo directly. Fix that, and a meson setup will work.

[andy5995]

Ok, I see that I was still using 'buildtarget.get_shared_lib()' in the canfigger/tests/meson build (I had forgotten to change it).

Thanks again, @eli-schwartz