[dpdk-dev] [PATCH v3 01/33] meson: add libatomic as a global dependency for i686 clang

[Bruce Richardson]

On Sun, Mar 29, 2020 at 08:13:10PM +0530, jerinj at marvell.com wrote:
> From: Pavan Nikhilesh <pbhagavatula at marvell.com>
> 
> Add libatomic as a global dependency when compiling for 32-bit using
> clang. As we need libatomic for 64-bit atomic ops.
> 
> Cc: bruce.richardson at intel.com
> Signed-off-by: Pavan Nikhilesh <pbhagavatula at marvell.com>
> ---
>  config/meson.build                  | 10 ++++++++++
>  drivers/event/octeontx/meson.build  |  5 -----
>  drivers/event/octeontx2/meson.build |  5 -----
>  drivers/event/opdl/meson.build      |  5 -----
>  examples/l2fwd-event/meson.build    |  5 -----
>  lib/librte_distributor/meson.build  |  5 -----
>  lib/librte_rcu/meson.build          |  5 -----
>  7 files changed, 10 insertions(+), 30 deletions(-)
> 
> diff --git a/config/meson.build b/config/meson.build
> index abedd76f2..6e5530110 100644
> --- a/config/meson.build
> +++ b/config/meson.build
> @@ -173,6 +173,16 @@ if pcap_dep.found() and cc.has_header('pcap.h', dependencies: pcap_dep)
>  	dpdk_extra_ldflags += '-lpcap'
>  endif
>  
> +
> +# for clang 32-bit compiles we need libatomic for 64-bit atomic ops
> +if cc.get_id() == 'clang' and dpdk_conf.get('RTE_ARCH_64') == false
> +	atomic_dep = cc.find_library('atomic', required: true)
> +	if atomic_dep.found()
> +		add_project_link_arguments('-latomic', language: 'c')
> +		dpdk_extra_ldflags += '-latomic'
> +	endif
> +endif
> +

Minor nit, you don't need to check for .found(), since the configure will
fail if it's not found, since "required" is set to true.

For cleanliness, you may also be able to use get_pkgconfig_variable() or
get_configtool_variable() to get -latomic, rather than hard-coding it,
though in this case I suspect hard-coding is fine.

With the superfluous if removed

Acked-by: Bruce Richardson <bruce.richardson at intel.com>