My project (in C) has a third party dependency at build time. But the third party library is, by default, installed to /opt/ instead of /lib, and I cannot find it in pkg-config. From mesonbuild's documentation, should I use declare_dependency, I don't have its source code to treat it as my sub-project. If I use dependency() to define it, I can't find the correct argument to define a customized location.
How to declare dependency for a non-standard third party library?
As documented here and here
The main use case for this [
declare_dependency()] is in subprojects.
and
[
dependency()] finds an external dependency ... withpkg-config[or] library-specific fallback detection logic ...
You can, instead, use find_library() provided by the compiler
object and include_directories() . find_library() returns an object just like the one declare_dependency() returns. include_directories() returns an opaque object which contains the directories.
Assuming you are using a C compiler and your 3rd party library and its header file are /opt/hello/libhello.so and /opt/hello/hello.h, you can do:
project('myproj', 'c')
cc = meson.get_compiler('c')
lib_hello = cc.find_library('hello',
dirs : ['/opt/hello'])
inc_hello = include_directories('/opt/hello')
exec = executable('app',
'main.c',
dependencies : [lib_hello],
include_directories : inc_hello)
Refer to meson object here : current_source_dir() method returns a string to the current source directory.
Use it for the case libhello.so and libhello.h are located in
<workspace>/hello directory
<workspace>/main.c
<workspace>/meson.build
<workspace>/hello/libhello.so
<workspace>/hello/libhello.h
<workspace>/hello/meson.build
In <workspace>/hello/meson.build:
lib_hello = cc.find_library('hello', dirs : meson.current_source_dir())
In <workspace>/meson.build:
project('myproj', 'c')
subdir('hello')
inc_hello = include_directories('./')
exec = executable('app',
'main.c',
dependencies : [lib_hello],
include_directories : inc_hello)
