[libcamera-devel] [PATCH] meson: Only build pipeline handlers needed in the host architecture

[Laurent Pinchart]

Hi Javier,

Thank you for the patch.

On Fri, Dec 23, 2022 at 09:22:29AM +0100, Javier Martinez Canillas wrote:
> By default all pipeline handlers are built, regardless on whether these
> are needed in the host architecture or not. It makes more sense to build
> only the pipeline handlers that will be used for the given architecture.
> 
> Let's do that by default now, but still allow to build the other pipeline
> handlers if needed, by using the `pipelines` meson option. For example:

As long as CI systems can build all pipeline handlers, that's fine with
me. We may start getting somes patches that introduce compilation
breakages on pipeline handlers that are not compile-tested by
developers, but we can catch that in CI.

>   $ meson build
>   ...
>     Configuration
>     Enabled pipelines        : ipu3
>                                simple
>                                uvcvideo
>     Enabled IPA modules      : ipu3
>   ...
> 
>   $ meson build -Dpipelines="ipu3,raspberrypi,rkisp1" -Dtest=true
>   ...
>     Configuration
>     Enabled pipelines        : ipu3
>                                raspberrypi
>                                rkisp1
>                                vimc
>     Enabled IPA modules      : ipu3
>                                raspberrypi
>                                rkisp1
>                                vimc
>   ...
> 
> Suggested-by: Kieran Bingham <kieran.bingham at ideasonboard.com>
> Signed-off-by: Javier Martinez Canillas <javierm at redhat.com>
> ---
> 
>  meson.build       | 14 ++++++++++++++
>  meson_options.txt |  6 ++++--
>  2 files changed, 18 insertions(+), 2 deletions(-)
> 
> diff --git a/meson.build b/meson.build
> index d02f9917965c..fc1023326ed3 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -164,6 +164,20 @@ liblttng = dependency('lttng-ust', required : get_option('tracing'))
>  # are enabled.
>  pipelines = get_option('pipelines')
>  
> +if pipelines.contains('auto')
> +    host_cpu = host_machine.cpu_family()
> +    if host_cpu == 'x86' or host_cpu == 'x86_64'
> +        pipelines = ['ipu3']
> +    elif host_cpu == 'aarch64'
> +        pipelines = ['imx8-isi', 'ipu3', 'raspberrypi', 'rkisp1']

ipu3 is only for x86.

> +    elif host_cpu == 'arm'
> +        pipelines = ['raspberrypi']
> +    endif
> +
> +    # Always include the simple and uvcvideo pipeline handlers.
> +    pipelines += ['simple', 'uvcvideo']

The simple pipeline handler is only useful on ARM platforms (both 32 and
64 bits) at the moment.

> +endif
> +
>  if get_option('test') and 'vimc' not in pipelines
>      message('Enabling vimc pipeline handler to support tests')
>      pipelines += ['vimc']
> diff --git a/meson_options.txt b/meson_options.txt
> index 1ba6778ce257..23505805de41 100644
> --- a/meson_options.txt
> +++ b/meson_options.txt
> @@ -37,8 +37,10 @@ option('lc-compliance',
>  
>  option('pipelines',
>          type : 'array',
> -        choices : ['imx8-isi', 'ipu3', 'raspberrypi', 'rkisp1', 'simple', 'uvcvideo', 'vimc'],
> -        description : 'Select which pipeline handlers to include')
> +        value : ['auto'],
> +        choices : ['auto', 'imx8-isi', 'ipu3', 'raspberrypi', 'rkisp1', 'simple', 'uvcvideo', 'vimc'],

This is getting long, let's wrap it:

        choices : [
            'auto',
            'imx8-isi',
            'ipu3',
            'raspberrypi',
            'rkisp1',
            'simple',
            'uvcvideo',
            'vimc',
        ],

> +        description : '''Select which pipeline handlers to build. If this is set to auto, all
> +                       the pipelines applicable to the target architecture will be built.''')

The spaces in the description cause weird-looking output depending on
the terminal width:

  pipelines                     [imx8-isi, ipu3, raspberrypi,   [auto, imx8-isi, ipu3,          Select which pipeline handlers to build. If this is set to auto,
                                rkisp1, simple, uvcvideo, vimc] raspberrypi, rkisp1, simple,    all                        the pipelines applicable to the
                                                                uvcvideo,                       target architecture will be built.
                                                                 vimc]

You can write

        description : '''Select which pipeline handlers to build. If this is set
to auto, all the pipelines applicable to the target architecture will be built.''')

or

        description : 'Select which pipeline handlers to build. If this is set to auto, all the pipelines applicable to the target architecture will be built.')

>  
>  option('qcam',
>          type : 'feature',

-- 
Regards,

Laurent Pinchart