Re: [dpdk-dev] [PATCH 1/5] build: simplify subdirectory detection for EAL

[Luca Boccassi <bluca@debian.org>]

On Tue, 2019-04-09 at 10:29 +0100, Bruce Richardson wrote:
> Within EAL we had a series of if statements for selecting the EAL
> directory
> to use. Now that the directory names match those of the OS's they are
> for
> we can instead just use a generated subdirectory name, shortening the
> code.
> To avoid strange errors, we still need to check for unsupported OS's,
> but
> do this check up-front in the config meson.build file.
> 
> Signed-off-by: Bruce Richardson <
> bruce.richardson@intel.com
> >
> ---
>  config/meson.build         |  7 +++++++
>  lib/librte_eal/meson.build | 17 ++---------------
>  2 files changed, 9 insertions(+), 15 deletions(-)
> 
> diff --git a/config/meson.build b/config/meson.build
> index 483139b10..ce6af2595 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -1,6 +1,13 @@
>  # SPDX-License-Identifier: BSD-3-Clause
>  # Copyright(c) 2017-2019 Intel Corporation
>  
> +# check the OS is supported, rather than going any further
> +supported_exec_envs = ['freebsd', 'linux', 'windows']
> +exec_env = host_machine.system()
> +if not supported_exec_envs.contains(exec_env)
> +	error('unsupported system type "@0@"'.format(exec_env))
> +endif
> +
>  # set the major version, which might be used by drivers and
> libraries
>  # depending on the configuration options
>  pver = meson.project_version().split('.')
> diff --git a/lib/librte_eal/meson.build b/lib/librte_eal/meson.build
> index 1863622c0..fa36b20e0 100644
> --- a/lib/librte_eal/meson.build
> +++ b/lib/librte_eal/meson.build
> @@ -9,21 +9,8 @@ subdir('common') # defines common_sources,
> common_objs, etc.
>  
>  # Now do OS/exec-env specific settings, including building kernel
> modules
>  # The <exec-env>/eal/meson.build file should define env_sources,
> etc.
> -if host_machine.system() == 'linux'
> -	dpdk_conf.set('RTE_EXEC_ENV_LINUX', 1)
> -	subdir('linux/eal')
> -
> -elif host_machine.system() == 'freebsd'
> -	dpdk_conf.set('RTE_EXEC_ENV_FREEBSD', 1)
> -	subdir('freebsd/eal')
> -
> -elif host_machine.system() == 'windows'
> -	dpdk_conf.set('RTE_EXEC_ENV_WINDOWS', 1)
> -	subdir('windows/eal')
> -
> -else
> -	error('unsupported system type
> "@0@"'.format(host_machine.system()))
> -endif
> +dpdk_conf.set('RTE_EXEC_ENV_' + exec_env.to_upper(), 1)
> +subdir(exec_env + '/eal')

Shouldn't this use join_paths() for cross-platform compat? Or does
foo/bar work fine these days in Windows?

-- 
Kind regards,
Luca Boccassi