[libvirt PATCH 0.5/2] meson: link libm

[Daniel P. Berrangé]

On Wed, Aug 26, 2020 at 04:35:10PM -0400, Laine Stump wrote:
> ****************
> (So here is a separate patch to add linking of libm. Care to ACK it?
> Also, what are peoples' opinions of pushing these patches now, so that
> they'll be in the upcoming release? I've put them on a private gitlab
> branch so that the CI is run (and found two mingw build problems :-)),
> except I haven't been able to make the cirrus-ci thing that builds
> freebsd and macos to work.)
> ****************

Given that our CI currently succeeds, we clearly don't have any bug
which neeeds fixing. Either the C library contains the functions, or
we're getting linkage to libm indirectly. With glibc it appears to be
the former. Fedora / RHEL linker probably gets libm indirectly, but
the Ubuntu/Debian linker wont.

Either way, it isn't important for the release since we're not showing
any broken builds currently.

> 
> On some platforms libm (needed for the pow() function) isn't being
> linked in somehow. This patch adds the necessary bits to assure that
> it's linked in when necessary.
> 
> Suggested-by: Michal Privoznik <mprivozn at redhat.com>
> Signed-off-by: Laine Stump <laine at redhat.com>
> ---
>  meson.build          | 3 +++
>  src/util/meson.build | 1 +
>  2 files changed, 4 insertions(+)
> 
> diff --git a/meson.build b/meson.build
> index dabd4196e6..81668a6681 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -1176,6 +1176,9 @@ endif
>  libxml_version = '2.9.1'
>  libxml_dep = dependency('libxml-2.0', version: '>=' + libxml_version)
>  
> +cc = meson.get_compiler('c')
> +m_dep = cc.find_library('m', required : false)
> +
>  use_macvtap = false
>  if not get_option('macvtap').disabled()
>    if (cc.has_header_symbol('linux/if_link.h', 'MACVLAN_MODE_BRIDGE') and
> diff --git a/src/util/meson.build b/src/util/meson.build
> index a7017f459f..f7092cc3f1 100644
> --- a/src/util/meson.build
> +++ b/src/util/meson.build
> @@ -188,6 +188,7 @@ virt_util_lib = static_library(
>      devmapper_dep,
>      gnutls_dep,
>      libnl_dep,
> +    m_dep,
>      numactl_dep,
>      secdriver_dep,
>      src_dep,

Reviewed-by: Daniel P. Berrangé <berrange at redhat.com>

Regards,
Daniel
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