[igt-dev] [PATCH i-g-t] meson: Add option to not build the assembler

[Arkadiusz Hiler]

On Mon, Aug 24, 2020 at 11:35:05AM +0300, Petri Latvala wrote:
> New option -Dassembler=disabled will omit assembler/ from the build.
> 
> Signed-off-by: Petri Latvala <petri.latvala at intel.com>
> Cc: Kalyan Kondapally <kalyan.kondapally at intel.com>
> Cc: Arkadiusz Hiler <arek at hiler.eu>
> Cc: Lukasz Fiedorowicz <lukasz.fiedorowicz at intel.com>
> ---
>  meson.build       | 4 +++-
>  meson_options.txt | 4 ++++
>  2 files changed, 7 insertions(+), 1 deletion(-)
> 
> diff --git a/meson.build b/meson.build
> index f4ee14f1..e8c8aaab 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -82,6 +82,7 @@ endforeach
>  build_chamelium = get_option('chamelium')
>  build_docs = get_option('docs')
>  build_tests = not get_option('tests').disabled()
> +build_assembler = get_option('assembler')
>  with_libdrm = get_option('libdrm_drivers')
>  
>  build_info = ['Build type: ' + get_option('buildtype')]
> @@ -306,9 +307,10 @@ build_info += 'Build tests: @0@'.format(build_tests)
>  subdir('benchmarks')
>  subdir('tools')
>  subdir('runner')
> -if libdrm_intel.found()
> +if libdrm_intel.found() and build_assembler.enabled()
>  	subdir('assembler')
>  endif
> +build_info += 'Build shader assembler: @0@'.format(build_assembler.enabled())

Are you sure this is going to do what you think it's going to do?

My understanding is that .enabled() on feature option object[0]
evaluates to true only if you explicityly set the option to 'enabled'.

Features default to auto unless changed with 'auto_features',
and we don't do that.

  $ meson build
  ...
  Message: Build shader assembler: false

vs

  $ meson -Dassembler=enabled build
  Message: Build shader assembler: true

This means we won't build assembler unless -Dassember=enabled, which
doesn't match with the commit message.

Also, drop a note in the NEWS - it may make some package maintainers a
bit happier :-)

[0]: https://mesonbuild.com/Reference-manual.html#feature-option-object

-- 
Cheers,
Arek