[libcamera-devel] [PATCH 07/11] Makes libdl optional when the runtime includes a dynamic loader.

[Laurent Pinchart]

Hi Nicholas,

Thank you for the patch.

On Mon, Oct 24, 2022 at 12:55:39AM -0500, Nicholas Roth via libcamera-devel wrote:
> From: Nicholas Roth <nicholas at rothemail.net>
> 
> ---
>  src/libcamera/meson.build | 7 ++++++-
>  1 file changed, 6 insertions(+), 1 deletion(-)
> 
> diff --git a/src/libcamera/meson.build b/src/libcamera/meson.build
> index 5f39d2e2..0494e808 100644
> --- a/src/libcamera/meson.build
> +++ b/src/libcamera/meson.build
> @@ -65,7 +65,12 @@ subdir('ipa')
>  subdir('pipeline')
>  subdir('proxy')
>  
> -libdl = cc.find_library('dl')
> +null_dep = dependency('', required : false)
> +
> +libdl = null_dep
> +if not cc.has_function('dlopen')
> +    libdl = cc.find_library('dl')
> +endif

I would have written that

if not cc.has_function('dlopen')
    libdl = cc.find_library('dl')
else
    libdl = null_dep
endif

but it's a matter of personal preference I suppose, I'm fine either way.

It would be nice to use dependency('dl') instead, but that has been
added in meson 0.62.0, and upgrading the minimum meson version would be
inconvenient as 0.62.0 isn't shipped by the latest Debian stable. Let's
capture that in a comment to simplify the code when we'll update the
requirement:

# TODO: Use dependency('dl') when updating to meson 0.62.0.
libdl = null_dep
if not cc.has_function('dlopen')
    libdl = cc.find_library('dl')
endif

Apart from that, this looks good.

>  libudev = dependency('libudev', required : false)
>  libyaml = dependency('yaml-0.1', required : false)
>  

-- 
Regards,

Laurent Pinchart