[PATCH 1/2] build: fail if explicitly requested lib is unbuildable

[Bruce Richardson]

Recheck-request: iol-unit-arm64-testing, iol-intel-Performance

I'm informed now that there were infra issues which should now have been fixed,
so requesting a second re-check.

/Bruce
On Fri, Sep 01, 2023 at 03:23:31PM +0100, Bruce Richardson wrote:
> When the user passes a list of desired libraries to build via the
> "enable_libs" option, the expectation is that those libraries should be
> part of the build. However, if those libs have either external or
> internal dependencies, they still may be silently disabled, for example:
> running "meson setup -Denable_libs=security build" will successfully
> run, but the security lib will not be configured as "cryptodev" is
> missing.
> 
> We can fix this by setting a flag to indicate when the libraries are
> specified via an enable_libs flag. If so, then we error out when a
> library is unbuildable, giving a suitable error message. For the above
> example case, the "meson setup" run fails with:
> 
> Message: Disabling security [lib/security]: missing internal dependency "cryptodev"
> 
> lib/meson.build:218:16: ERROR: Problem encountered: Cannot build explicitly requested lib "security".
> 	Please add missing dependency "cryptodev" to "enable_libs" option
> 
> Signed-off-by: Bruce Richardson <bruce.richardson at intel.com>
> ---
>  lib/meson.build | 10 ++++++++++
>  1 file changed, 10 insertions(+)
> 
> diff --git a/lib/meson.build b/lib/meson.build
> index 099b0ed18a..cf4aa63630 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -131,7 +131,9 @@ endforeach
>  disable_libs = run_command(list_dir_globs, get_option('disable_libs'), check: true).stdout().split()
>  
>  enable_libs = run_command(list_dir_globs, get_option('enable_libs'), check: true).stdout().split()
> +require_libs = true
>  if enable_libs.length() == 0
> +    require_libs = false
>      enable_libs += optional_libs
>  endif
>  enable_libs += always_enable
> @@ -189,6 +191,10 @@ foreach l:libraries
>  
>      if build
>          subdir(l)
> +        if not build and require_libs
> +            error('Cannot build explicitly requested lib "@0@".\n'.format(name)
> +                    +'\tReason: ' + reason)
> +        endif
>      endif
>      if name != l
>          warning('Library name, "@0@", and directory name, "@1@", do not match'.format(name, l))
> @@ -208,6 +214,10 @@ foreach l:libraries
>              endif
>              message('Disabling @1@ [@2@]: missing internal dependency "@0@"'
>                      .format(d, name, 'lib/' + l))
> +            if require_libs
> +                error('Cannot build explicitly requested lib "@0@".\n'.format(name)
> +                        + '\tPlease add missing dependency "@0@" to "enable_libs" option'.format(d))
> +            endif
>          else
>              shared_deps += [get_variable('shared_rte_' + d)]
>              static_deps += [get_variable('static_rte_' + d)]
> -- 
> 2.39.2
>