aclocal-flags

#!/bin/sh
#
# This script returns the flags to be fed to "aclocal" to ensure that
# it finds GLib's aclocal macros (we assume GTK+ is installed in the
# same place as GLib) and pkg-config's aclocal macros.
#
# aclocal will search, by default, only in a directory in the same
# tree where it was installed - e.g., if installed in "/usr/bin", it'll
# search only in "/usr/share/aclocal", and if installed in "/usr/local/bin",
# it'll search only in "/usr/local/share/aclocal".
#
# However, there is no guarantee that GLib, or pkg-config has been installed
# there; if either of them hasn't been installed there, aclocal won't find
# the autoconf macros for whichever of them wan't, and will complain
# bitterly.
#
# So:
#
#	if pkg-config is found with a path that ends with "bin/pkg-config",
#	and the "share/local" directory under the directory at the path
#	that's the part of the pkg-config path preceding "bin/pkg-config"
#	isn't the same directory as the directory reported by "aclocal
#	--print-ac-dir", we include in our output a "-I" flag with that
#	directory as its argument;
#
#	if the "share/local" directory under the directory reported by
#	"pkg-config --variable=prefix glib-2.0" isn't the same directory
#	as the directory reported by "aclocal --print-ac-dir", we include
#	in our output a "-I" flag with the first of those directories as
#	the argument.
#
# If either of them *is* the same directory as the directory reported by
# "aclocal --print-ac-dir", and we supply that "-I" flag, "aclocal" will
# look in that directory twice, and get well and truly confused, reporting
# a ton of duplicate macro definitions.  This also means that if pkg-config
# and Glib are installed with the same prefix, we should only supply one
# "-I" flag for both of them.
#
# $Id$
#

#
# OK, where will aclocal look by default?
#
aclocal_dir=`aclocal --print-ac-dir`

#
# And where do we want to make sure it looks?
# Look for pkg-config first.
#
pkg_config_path=`command -v pkg-config 2>/dev/null`
if [ -z "$pkg_config_path" ]
then
	#
	# Either we don't have "command" (which is required by recent
	# POSIX) or it didn't find pkg-config.
	#
	pkg_config_aclocal_dir=""
else
	#
	# OK, we found pkg-config; attempt to find the prefix for it, by
	# stripping off "bin/pkg-config".
	#
	pkg_config_prefix=`expr "$pkg_config_path" : '\(.*\)/bin/pkg-config'`
	if [ -z "$pkg_config_prefix" ]
	then
		#
		# Well, we couldn't strip it off, for whatever reason.
		#
		pkg_config_aclocal_dir=""
	else
		#
		# Solaris 11's default pkg-config installation puts
		# it in /usr/ccs/bin, but there's no /usr/ccs/share.
		# Map /usr/ccs to /usr.
		#
		# Ubuntu 7.10 has /usr/X11R6/bin as a symbolic link
		# to /usr/bin, but there's no /usr/X11R6/share.  If
		# /usr/X11R6/bin is a symlink to /usr/bin, map
		# /usr/X11R6 to /usr.
		#
		if [ "$pkg_config_prefix" = /usr/ccs ]
		then
			pkg_config_prefix=/usr
		elif [ "$pkg_config_prefix" = /usr/X11R6 ]
		then
			if expr "`ls -ld /usr/X11R6/bin`" : '.*/usr/X11R6/bin -> .*/bin$' >/dev/null
			then
				pkg_config_prefix=/usr
			fi
		fi

		#
		# Now get the path of its aclocal directory.
		#
		pkg_config_aclocal_dir=$pkg_config_prefix/share/aclocal
	fi
fi

#
# Now see where glib is installed.
#
glib_prefix=`pkg-config --variable=prefix glib-2.0 2>/dev/null`

#
# Now get the path of its aclocal directory.
#
if [ -z "$glib_prefix" ]
then
	glib_aclocal_dir=""
else
	glib_aclocal_dir=$glib_prefix/share/aclocal
fi

#
# Add our aclocal-fallback to the path.
# We write out the -I flag for it, and strip off CR and LF, as we may
# be writing more -I options, and we want all the options to be on
# one line.
#
ac_missing_dir=`dirname $0`
echo "-I $ac_missing_dir/aclocal-fallback" | tr -d '\012' | tr -d '\015'

#
# If there's no aclocal, aclocal_dir, which is the path where aclocal
# searches, will be empty; if we didn't find pkg-config,
# pkg_config_aclocal_dir, which is the path where it should search
# for pkg-config's macros, will be empty.  Add pkg_config_aclocal_dir only
# if both it and aclocal_dir are non-empty and different from each other.
#
if [ ! -z "$aclocal_dir" -a ! -z "$pkg_config_aclocal_dir" \
    -a "$aclocal_dir" != "$pkg_config_aclocal_dir" ]
then
	echo " -I $pkg_config_aclocal_dir" | tr -d '\012' | tr -d '\015'
fi

#
# If pkg-config doesn't know about glib-2.0, glib_aclocal_dir will be
# empty.  (Should we just fail in that case?  Does that mean we don't
# have GLib installed?)
#
# Add glib_aclocal_dir only if both it and aclocal_dir are non-empty and
# different from each other *and* pkg_config_aclocal_dir is different from
# glib_aclocal_dir.  (We don't need to check whether pkg_config_aclocal_dir
# is empty; if it is, then either glib_aclocal_dir is also empty, in which
# case we'll bail out before even looking at pkg_config_aclocal_dir, or
# it's non-empty, in which case it obviously won't be equal to
# pkg_config_aclocal_dir.)
#
if [ ! -z "$aclocal_dir" -a ! -z "$glib_aclocal_dir" \
    -a "$aclocal_dir" != "$glib_aclocal_dir" \
    -a "$pkg_config_aclocal_dir" != "$glib_aclocal_dir" ]
then
	echo " -I $glib_aclocal_dir" | tr -d '\012' | tr -d '\015'
fi

#
# Put out the final line ending.
#
echo
exit 0