[libcamera-devel] [PATCH] meson: Use dependency() instead of find_library() where possible

[Kieran Bingham]

Quoting Laurent Pinchart via libcamera-devel (2022-08-14 20:11:09)
> Usage of find_library() to find dependencies that libcamera needs to
> compile against can lead to the library being found even if the
> corresponding headers are not installed. This will then result in a
> compilation failure. Switch to dependency() for libdw, libunwind and
> lttng-ust to fix this, all three libraries come with a pkgconfig file
> that is usually installed by the distribution package that contains the
> library headers.

Can you clarify (perhaps here in the commit message even) why you
haven't changed the others?

In particular, gnutls does have a pkg-config for me, so I would expect
it to be updated too?

atomic, dl, and libc++ I suspect are special cases?

> Reported-by: Christian Rauch <Rauch.Christian at gmx.de>
> Signed-off-by: Laurent Pinchart <laurent.pinchart at ideasonboard.com>
> ---
>  meson.build                    | 2 +-
>  src/libcamera/base/meson.build | 4 ++--
>  2 files changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/meson.build b/meson.build
> index e8b81ad87a6e..72919102ad55 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -122,7 +122,7 @@ libcamera_includes = include_directories('include')
>  py_modules = []
>  
>  # Libraries used by multiple components
> -liblttng = cc.find_library('lttng-ust', required : get_option('tracing'))
> +liblttng = dependency('lttng-ust', required : get_option('tracing'))
>  
>  # Pipeline handlers
>  #
> diff --git a/src/libcamera/base/meson.build b/src/libcamera/base/meson.build
> index 7030ad1f5927..3b9d74efe935 100644
> --- a/src/libcamera/base/meson.build
> +++ b/src/libcamera/base/meson.build
> @@ -22,8 +22,8 @@ libcamera_base_sources = files([
>      'utils.cpp',
>  ])
>  
> -libdw = cc.find_library('libdw', required : false)
> -libunwind = cc.find_library('libunwind', required : false)
> +libdw = dependency('libdw', required : false)
> +libunwind = dependency('libunwind', required : false)
>  
>  if cc.has_header_symbol('execinfo.h', 'backtrace')
>      config_h.set('HAVE_BACKTRACE', 1)
> 
> base-commit: dfc6d711c9f7f0a9868afa5158aa2089163bded3
> -- 
> Regards,
> 
> Laurent Pinchart
>