Re: [RFC PATCH v3 1/5] build-sys: Add rust feature option

[Zhao Liu <zhao1.liu@intel.com>]

[snip]

> diff --git a/meson.build b/meson.build
> index c5360fbd299..ad7dbc0d641 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -290,6 +290,11 @@ foreach lang : all_languages
>    endif
>  endforeach
> +cargo = not_found
> +if 'RUST_TARGET_TRIPLE' in config_host
> +  cargo = find_program('cargo', required: true)
> +endif
> +

As with the original Manos version, it looks like there's no need to
check cargo here? Since patch 2 checks cargo and others in rust/meson.build.

Otherwise, cargo was checked twice.

>  # default flags for all hosts
>  # We use -fwrapv to tell the compiler that we require a C dialect where
>  # left shift of signed integers is well defined and has the expected
> @@ -4239,6 +4244,10 @@ if 'objc' in all_languages
>  else
>    summary_info += {'Objective-C compiler': false}
>  endif
> +summary_info += {'Rust support':      cargo.found()}
> +if cargo.found() and config_host['RUST_TARGET_TRIPLE']) != config_host['RUST_HOST_TRIPLE']
> +  summary_info += {'Rust target':     config_host['RUST_TARGET_TRIPLE']}
> +endif
>  option_cflags = (get_option('debug') ? ['-g'] : [])
>  if get_option('optimization') != 'plain'
>    option_cflags += ['-O' + get_option('optimization')]
> 
>