Meson, how to get include directories of external dependency?

Question

I have a subproject in meson that uses imgui. Due to a bug in meson, I have to override a command line argument for imgui, otherwise things won't compile:

i.e. I do something like this:

imgui_lib = library(
    'imgui',
    sources : [imgui_sources],
    dependencies : [dependency('imgui')],
    include_directories : [
        '../../../ext/imgui/bindings'
    ],
    cpp_args : ['-DIMGUI_USER_CONFIG="imgui_user_config.h"'])
imgui_dep = declare_dependency(
    link_with:imgui_lib,
    include_directories: [
        '.',
        imgui_bindings,
    ])

The bug is that meson deletes quotations in variables so -DIMGUI_USER_CONFIG="imgui_user_config.h" becomes -DIMGUI_USER_CONFIG=imgui_user_config.h

Which is trivially wrong and causes compilation errors.

This works fine, however it requires me to repeat this pattern whenever I use imgui, i.e. I have to do that override every single time, which is not fun.

I want, as part of my imgui_dep object for the imgui path to be part of the includes, i.e. I want something like:

imgui_dep = declare_dependency(
    link_with:imgui_lib,
    include_directories: [
        '.',
        imgui_bindings,
        imgui.get_include_dirs()
    ])

So far I tried:

imgui.get_variable('includedir')

But this results in the error: ERROR: Could not get pkg-config variable and no default provided for <PkgConfigDependency imgui: True None>

All I want is the path to the include directories in that dependency, that's it, how do I fetch them?

Answer 1

What I usually do is simple:

my_lib_inc_dir = './my_lib/includes'

# Create dependency
my_lib_dep = declare_dependency(
  dependencies: my_lib,
  include_directories: include_directories(my_lib_inc_dir)
)

And then just link your lib with this dependency and it pulls include dir location automatically.