Who provides $host_os variable for xserver's configure.ac script?

[Alan Coopersmith]

On 06/22/15 04:30 PM, Laércio de Sousa wrote:
> I'm figuring out why Debian xorg-server builds are failing to automatically
> enable kdrive's evdev input driver. It seems variable "host_os", which is
> referenced several times in configure.ac <http://configure.ac>, is undefined
> when Xorg is built in Debian. However, I've found no other occurrence of this
> variable in any other file in xserver tree.
>
> Where host_os should be defined?

By autoconf's AC_CANONICAL_HOST macro:
http://www.gnu.org/savannah-checkouts/gnu/autoconf/manual/autoconf-2.69/html_node/Canonicalizing.html#Canonicalizing

which is called via the XORG_MANPAGE_SECTIONS macro in xorg-macros.m4,
which is called via the XORG_DEFAULT_OPTIONS macro in xorg-macros.m4,
which is called from the xserver/configure.ac script.

-- 
	-Alan Coopersmith-              alan.coopersmith at oracle.com
	 Oracle Solaris Engineering - http://blogs.oracle.com/alanc