#!/bin/sh
#
# This file is in the public domain.

ident='$FreeBSD$'

#
# usage: show { settings | options } ...
#
show()
{

	mode=$1; shift
	case ${mode} in
	settings)
		yes_prefix=WITH
		no_prefix=WITHOUT
		;;
	options)
		yes_prefix=WITHOUT
		no_prefix=WITH
		;;
	*)
		echo "internal error" >/dev/stderr
		exit 1
		;;
	esac
	(
		cd ../../..
		make "$@" showconfig SRCCONF=/dev/null __MAKE_CONF=/dev/null
	) |
	while read var _ val; do
		opt=${var#MK_}
		case ${val} in
		yes)
			echo ${yes_prefix}_${opt}
			;;
		no)
			echo ${no_prefix}_${opt}
			;;
		*)
			echo "make showconfig broken" >/dev/stderr
			exit 1
			;;
		esac
	done
}

main()
{

	trap 'rm -f _defcfg _config _config2 _deps _deps2' exit
	ident=${ident#$}
	ident=${ident% $}
	fbsdid='$'FreeBSD'$'
	cat <<EOF
.\" DO NOT EDIT-- this file is automatically generated.
.\" from ${ident}
.\" ${fbsdid}
.Dd $(LC_TIME=C date +'%B %e, %Y')
.Dt SRC.CONF 5
.Os
.Sh NAME
.Nm src.conf
.Nd "source build options"
.Sh DESCRIPTION
The
.Nm
file contains settings that will apply to every build involving the
.Fx
source tree; see
.Xr build 7 .
.Pp
The
.Nm
file uses the standard makefile syntax.
However,
.Nm
should not specify any dependencies to
.Xr make 1 .
Instead,
.Nm
is to set
.Xr make 1
variables that control the aspects of how the system builds.
.Pp
The default location of
.Nm
is
.Pa /etc/src.conf ,
though an alternative location can be specified in the
.Xr make 1
variable
.Va SRCCONF .
Overriding the location of
.Nm
may be necessary if the system-wide settings are not suitable
for a particular build.
For instance, setting
.Va SRCCONF
to
.Pa /dev/null
effectively resets all build controls to their defaults.
.Pp
The only purpose of
.Nm
is to control the compilation of the
.Fx
source code, which is usually located in
.Pa /usr/src .
As a rule, the system administrator creates
.Nm
when the values of certain control variables need to be changed
from their defaults.
.Pp
In addition, control variables can be specified
for a particular build via the
.Fl D
option of
.Xr make 1
or in environment; see
.Xr environ 7 .
.Pp
The values of variables are ignored regardless of their setting;
even if they would be set to
.Dq Li FALSE
or
.Dq Li NO .
Just the existence of an option will cause
it to be honoured by
.Xr make 1 .
.Pp
The following list provides a name and short description for variables
that can be used for source builds.
.Bl -tag -width indent
EOF
	show settings |sort >_defcfg
	show options |
	while read opt; do
		if [ -f ${opt} ]; then
			cat <<EOF
.It Va ${opt}
EOF
			sed -e's/\$\(FreeBSD: .*\) \$/from \1/' ${opt}
		else
			echo "no description found for ${opt}, skipping" >/dev/stderr
			continue
		fi
		show settings -D${opt} |sort >_config
		comm -13 _defcfg _config |grep -v "^${opt}$" >_deps
		if [ -s _deps ]; then
			cat <<EOF
When set, it also enforces the following options:
.Pp
.Bl -item -compact
EOF
			cat _deps |while read opt2; do
				cat <<EOF
.It
.Va ${opt2}
EOF
				show settings -D${opt} $(
				    echo ${opt2} |
				    sed -e's/^WITHOUT_/-DWITH_/' -e's/^WITH_/-DWITHOUT_/'
				) |sort >_config2
				comm -13 _config _config2 >_deps2
				if [ -s _deps2 ]; then
					cat <<EOF
(can be overridden with
.Va $(cat _deps2) )
EOF
				fi
			done
				cat <<EOF
.El
EOF
		fi
	done
	cat <<EOF
.El
.Sh FILES
.Bl -tag -compact
.It Pa /etc/src.conf
.It Pa /usr/share/mk/bsd.own.mk
.El
.Sh SEE ALSO
.Xr make 1 ,
.Xr make.conf 5 ,
.Xr build 7 ,
.Xr ports 7
.Sh HISTORY
The
.Nm
file appeared in
.Fx 7.0 .
.Sh AUTHORS
This manual page was autogenerated.
EOF
}

main