Re: [dpdk-dev] [PATCH v2 1/1] build: enable BSD features visibility for FreeBSD

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> 
> When a component uses either XOPEN_SOURCE or POSIX_C_SOURCE macro
> explicitly in its build recipe, it restricts visibility of a non POSIX
> features subset, such as IANA protocol numbers (IPPROTO_* macros).
> Non standard features are enabled by default for DPDK both for Linux
> thanks to _GNU_SOURCE and for FreeBSD thanks to __BSD_VISIBLE. However
> using XOPEN_SOURCE or POSIX_(C_)SOURCE in a component causes
> __BSD_VISIBLE to be defined to 0 for FreeBSD, causing different feature
> sets visibility for Linux and FreeBSD. It restricts from using IPPROTO
> macros in public headers, such as rte_ip.h, despite the fact they are
> already widely used in sources.
> 
> Add __BSD_VISIBLE macro specified unconditionally for FreeBSD targets
> which enforces feature sets visibility unification between Linux and
> FreeBSD.
> 
> Add single -D_GNU_SOURCE to config/meson.build as a project argument
> instead of adding separate directive for each project subtree.
> 
> This patch solves the problem of build breaks for [1] on FreeBSD [2]
> following the discussion [3].
> 
> [1] https://mails.dpdk.org/archives/dev/2019-May/131885.html
> [2] http://mails.dpdk.org/archives/test-report/2019-May/082263.html
> [3] https://mails.dpdk.org/archives/dev/2019-May/132110.html
> 
> Signed-off-by: Marcin Smoczynski <marcinx.smoczynski@intel.com>
> ---
>  app/meson.build               | 3 ---
>  config/meson.build            | 8 ++++++++
>  drivers/meson.build           | 3 ---
>  examples/meson.build          | 3 ---
>  lib/meson.build               | 3 ---
>  meson.build                   | 6 +++++-
>  mk/target/generic/rte.vars.mk | 5 +++++
>  7 files changed, 18 insertions(+), 13 deletions(-)
> 
> diff --git a/app/meson.build b/app/meson.build
> index 2b9fdef74..b0e6afbbe 100644
> --- a/app/meson.build
> +++ b/app/meson.build
> @@ -22,9 +22,6 @@ lib_execinfo = cc.find_library('execinfo', required: false)
> 
>  default_cflags = machine_args
> 
> -# specify -D_GNU_SOURCE unconditionally
> -default_cflags += '-D_GNU_SOURCE'
> -
>  foreach app:apps
>  	build = true
>  	name = app
> diff --git a/config/meson.build b/config/meson.build
> index 0d25646f5..b77c87811 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -187,3 +187,11 @@ install_headers('rte_config.h', subdir: get_option('include_subdir_arch'))
> 
>  # enable VFIO only if it is linux OS
>  dpdk_conf.set('RTE_EAL_VFIO', is_linux)
> +
> +# specify -D_GNU_SOURCE unconditionally
> +add_project_arguments('-D_GNU_SOURCE', language: 'c')
> +
> +# specify -D__BSD_VISIBLE for FreeBSD
> +if is_freebsd
> +	add_project_arguments('-D__BSD_VISIBLE', language: 'c')
> +endif
> diff --git a/drivers/meson.build b/drivers/meson.build
> index 4c444f495..dc47b45ec 100644
> --- a/drivers/meson.build
> +++ b/drivers/meson.build
> @@ -21,9 +21,6 @@ if cc.has_argument('-Wno-format-truncation')
>  	default_cflags += '-Wno-format-truncation'
>  endif
> 
> -# specify -D_GNU_SOURCE unconditionally
> -default_cflags += '-D_GNU_SOURCE'
> -
>  foreach class:dpdk_driver_classes
>  	drivers = []
>  	std_deps = []
> diff --git a/examples/meson.build b/examples/meson.build
> index 1a6134f12..6e18ca8ec 100644
> --- a/examples/meson.build
> +++ b/examples/meson.build
> @@ -31,9 +31,6 @@ if cc.has_argument('-Wno-format-truncation')
>  	default_cflags += '-Wno-format-truncation'
>  endif
> 
> -# specify -D_GNU_SOURCE unconditionally
> -default_cflags += '-D_GNU_SOURCE'
> -
>  foreach example: examples
>  	name = example
>  	build = true
> diff --git a/lib/meson.build b/lib/meson.build
> index e067ce5ea..dd7c94c03 100644
> --- a/lib/meson.build
> +++ b/lib/meson.build
> @@ -41,9 +41,6 @@ endif
> 
>  enabled_libs = [] # used to print summary at the end
> 
> -# -D_GNU_SOURCE unconditionally
> -default_cflags += '-D_GNU_SOURCE'
> -
>  foreach l:libraries
>  	build = true
>  	name = l
> diff --git a/meson.build b/meson.build
> index 46f9c5683..05c816a9e 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -64,6 +64,10 @@ configure_file(output: build_cfg,
>  dpdk_drivers = ['-Wl,--whole-archive'] + dpdk_drivers + ['-Wl,--no-whole-archive']
> 
>  pkg = import('pkgconfig')
> +pkg_extra_cflags = ['-include', 'rte_config.h'] + machine_args
> +if is_freebsd
> +	pkg_extra_cflags += ['-D__BSD_VISIBLE']
> +endif
>  pkg.generate(name: meson.project_name(),
>  	filebase: 'lib' + meson.project_name().to_lower(),
>  	version: meson.project_version(),
> @@ -76,7 +80,7 @@ pkg.generate(name: meson.project_name(),
>  Note that CFLAGS might contain an -march flag higher than typical baseline.
>  This is required for a number of static inline functions in the public headers.''',
>  	subdirs: [get_option('include_subdir_arch'), '.'],
> -	extra_cflags: ['-include', 'rte_config.h'] + machine_args
> +	extra_cflags: pkg_extra_cflags
>  )
> 
>  # final output, list all the libs and drivers to be built
> diff --git a/mk/target/generic/rte.vars.mk b/mk/target/generic/rte.vars.mk
> index 25a578ad7..5f00a0bfa 100644
> --- a/mk/target/generic/rte.vars.mk
> +++ b/mk/target/generic/rte.vars.mk
> @@ -111,6 +111,11 @@ endif
>  # always define _GNU_SOURCE
>  CFLAGS += -D_GNU_SOURCE
> 
> +# define __BSD_VISIBLE when building for FreeBSD
> +ifeq ($(CONFIG_RTE_EXEC_ENV_FREEBSD),y)
> +CFLAGS += -D__BSD_VISIBLE
> +endif
> +
>  export CFLAGS
>  export LDFLAGS
> 
> --

Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

> 2.17.1