[libsigrok.git] / m4 / sigrok.m4

## Copyright (c) 2009  Openismus GmbH
## Copyright (c) 2015  Daniel Elstner <daniel.kitta@gmail.com>
##
## This file is part of the sigrok project.
##
## sigrok is free software: you can redistribute it and/or modify it
## under the terms of the GNU General Public License as published by
## the Free Software Foundation, either version 3 of the License, or
## (at your option) any later version.
##
## sigrok is distributed in the hope that it will be useful,
## but WITHOUT ANY WARRANTY; without even the implied warranty of
## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
## GNU General Public License for more details.
##
## You should have received a copy of the GNU General Public License
## along with sigrok. If not, see <http://www.gnu.org/licenses/>.

#serial 20150823

## SR_APPEND(var-name, [list-sep,] element)
##
## Append the shell word <element> to the shell variable named <var-name>,
## prefixed by <list-sep> unless the list was empty before appending. If
## only two arguments are supplied, <list-sep> defaults to a single space
## character.
##
AC_DEFUN([SR_APPEND],
[dnl
m4_assert([$# >= 2])[]dnl
$1=[$]{$1[}]m4_if([$#], [2], [[$]{$1:+' '}$2], [[$]{$1:+$2}$3])[]dnl
])

## _SR_PKG_VERSION_SET(var-prefix, pkg-name, tag-prefix, base-version, major, minor, [micro])
##
m4_define([_SR_PKG_VERSION_SET],
[dnl
m4_assert([$# >= 6])[]dnl
$1=$4
sr_git_deps=
# Check if we can get revision information from git.
sr_head=`git -C "$srcdir" rev-parse --verify --short HEAD 2>&AS_MESSAGE_LOG_FD`

AS_IF([test "$?" = 0 && test "x$sr_head" != x], [dnl
	test ! -f "$srcdir/.git/HEAD" \
		|| sr_git_deps="$sr_git_deps \$(top_srcdir)/.git/HEAD"

	sr_head_name=`git -C "$srcdir" rev-parse --symbolic-full-name HEAD 2>&AS_MESSAGE_LOG_FD`
	AS_IF([test "$?" = 0 && test -f "$srcdir/.git/$sr_head_name"],
		[sr_git_deps="$sr_git_deps \$(top_srcdir)/.git/$sr_head_name"])

	# Append the revision hash unless we are exactly on a tagged release.
	git -C "$srcdir" describe --match "$3$4" \
		--exact-match >&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD \
		|| $1="[$]$1-git-$sr_head"
])
# Use $(wildcard) so that things do not break if for whatever
# reason these files do not exist anymore at make time.
AS_IF([test -n "$sr_git_deps"],
	[SR_APPEND([CONFIG_STATUS_DEPENDENCIES], ["\$(wildcard$sr_git_deps)"])])
AC_SUBST([CONFIG_STATUS_DEPENDENCIES])[]dnl
AC_SUBST([$1])[]dnl
dnl
AC_DEFINE([$1_MAJOR], [$5], [Major version number of $2.])[]dnl
AC_DEFINE([$1_MINOR], [$6], [Minor version number of $2.])[]dnl
m4_ifval([$7], [AC_DEFINE([$1_MICRO], [$7], [Micro version number of $2.])])[]dnl
AC_DEFINE_UNQUOTED([$1_STRING], ["[$]$1"], [Version of $2.])[]dnl
])

## SR_PKG_VERSION_SET(var-prefix, version-triple)
##
## Set up substitution variables and macro definitions for the package
## version components. Derive the version suffix from the repository
## revision if possible.
##
## Substitutions: <var-prefix>
## Macro defines: <var-prefix>_{MAJOR,MINOR,MICRO,STRING}
##
AC_DEFUN([SR_PKG_VERSION_SET],
[dnl
m4_assert([$# >= 2])[]dnl
_SR_PKG_VERSION_SET([$1],
	m4_defn([AC_PACKAGE_NAME]),
	m4_defn([AC_PACKAGE_TARNAME])[-],
	m4_expand([$2]),
	m4_unquote(m4_split(m4_expand([$2]), [\.])))
])

## _SR_LIB_VERSION_SET(var-prefix, pkg-name, abi-triple, current, revision, age)
##
m4_define([_SR_LIB_VERSION_SET],
[dnl
m4_assert([$# >= 6])[]dnl
$1=$3
AC_SUBST([$1])[]dnl
AC_DEFINE([$1_CURRENT], [$4], [Binary version of $2.])[]dnl
AC_DEFINE([$1_REVISION], [$5], [Binary revision of $2.])[]dnl
AC_DEFINE([$1_AGE], [$6], [Binary age of $2.])[]dnl
AC_DEFINE([$1_STRING], ["$3"], [Binary version triple of $2.])[]dnl
])

## SR_LIB_VERSION_SET(var-prefix, abi-triple)
##
## Set up substitution variables and macro definitions for a library
## binary version.
##
## Substitutions: <var-prefix>
## Macro defines: <var-prefix>_{CURRENT,REVISION,AGE,STRING}
##
AC_DEFUN([SR_LIB_VERSION_SET],
[dnl
m4_assert([$# >= 1])[]dnl
_SR_LIB_VERSION_SET([$1],
	m4_defn([AC_PACKAGE_NAME]),
	[$2], m4_unquote(m4_split([$2], [:])))
])

## _SR_VAR_SUMMARY(tag, var-name, line-leader, align-columns, align-char)
##
m4_define([_SR_VAR_SUMMARY], [dnl
$2=
$1_append() {
	sr_aligned=`printf '%.$4s' "[$][1]m4_for([i], [1], [$4],, [$5])"`
	$2="[$]{$2}$3$sr_aligned [$]2"'
'
}
])

## SR_VAR_SUMMARY(tag, [var-name = <tag>],
##                [line-leader = [ - ]], [align-columns = 32], [align-char = .])
##
## Define a shell function <tag>_append() to be used for aggregating
## a summary of test results in the shell variable <var-name>.
##
AC_DEFUN([SR_VAR_SUMMARY],
[dnl
m4_assert([$# >= 1])[]dnl
_SR_VAR_SUMMARY([$1],
	m4_default_quoted([$2], [$1]),
	m4_default_quoted([$3], [ - ]),
	m4_default_quoted([$4], [32]),
	m4_default_quoted([$5], [.]))[]dnl
])

## SR_PKG_CHECK_SUMMARY([var-name = sr_pkg_check_summary],
##                      [line-leader = [ - ]], [align-columns = 32], [align-char = .])
##
## Prepare for the aggregation of package check results
## in the shell variable <var-name>.
##
AC_DEFUN([SR_PKG_CHECK_SUMMARY],
	[SR_VAR_SUMMARY([sr_pkg_check_summary], $@)])

## SR_PKG_CHECK(tag, [collect-var], module...)
##
## Check for each pkg-config <module> in the argument list. <module> may
## include a version constraint.
##
## Output variables: sr_have_<tag>, sr_<tag>_version
##
AC_DEFUN([SR_PKG_CHECK],
[dnl
m4_assert([$# >= 3])[]dnl
AC_REQUIRE([PKG_PROG_PKG_CONFIG])[]dnl
AC_REQUIRE([SR_PKG_CHECK_SUMMARY])[]dnl
dnl
PKG_CHECK_EXISTS([$3], [dnl
	sr_have_$1=yes
	m4_ifval([$2], [SR_APPEND([$2], ["$3"])
	])sr_$1_version=`$PKG_CONFIG --modversion "$3" 2>&AS_MESSAGE_LOG_FD`
	sr_pkg_check_summary_append "$3" "$sr_$1_version"[]dnl
], [dnl
	sr_pkg_check_summary_append "$3" no
	m4_ifval([$4],
		[SR_PKG_CHECK([$1], [$2], m4_shift3($@))],
		[sr_have_$1=no sr_$1_version=])[]dnl
])
])

## SR_VAR_OPT_PKG([modules-var], [features-var])
##
## Enable the collection of SR_ARG_OPT_PKG results into the shell variables
## <modules-var> and <features-var>.
##
AC_DEFUN([SR_VAR_OPT_PKG],
[dnl
m4_define([_SR_VAR_OPT_PKG_MODULES], [$1])[]dnl
m4_define([_SR_VAR_OPT_PKG_FEATURES], [$2])[]dnl
m4_ifvaln([$1], [$1=])[]dnl
m4_ifvaln([$2], [$2=])[]dnl
])

## _SR_ARG_OPT_PKG(sh-name, [modules-var], [features-var],
##                 opt-name, [cpp-name], [cond-name], module...)
##
m4_define([_SR_ARG_OPT_PKG],
[dnl
AC_ARG_WITH([$4], [AS_HELP_STRING([--without-$4],
			[disable $4 support [default=detect]])])
AS_IF([test "x$with_$1" = xno], [sr_have_$1=no],
	[test "x$sr_have_$1" != xyes],
		[SR_PKG_CHECK([$1], [$2], m4_shiftn([6], $@))])
AS_IF([test "x$with_$1$sr_have_$1" = xyesno],
	[AC_MSG_ERROR([$4 support requested, but it was not found.])])
AS_IF([test "x$sr_have_$1" = xyes], [m4_ifval([$3], [
	SR_APPEND([$3], ["$4"])])[]m4_ifval([$5], [
	AC_DEFINE([HAVE_$5], [1], [Whether $4 is available.])
	AC_DEFINE_UNQUOTED([CONF_$5_VERSION], ["$sr_$1_version"],
		[Build-time version of $4.])])[]dnl
])
m4_ifvaln([$6], [AM_CONDITIONAL([$6], [test "x$sr_have_$1" = xyes])])[]dnl
])

## SR_ARG_OPT_PKG(opt-name, [cpp-name], [cond-name], module...)
##
## Provide a --without-<opt-name> configure option for explicit disabling
## of an optional dependency. If not disabled, the availability of the
## optional dependency is auto-detected.
##
## Each pkg-config <module> argument is checked in turn, and the first one
## found is selected. On success, the shell variable sr_have_<opt-name>
## is set to "yes", otherwise to "no". Optionally, a preprocessor macro
## HAVE_<cpp-name> and an Automake conditional <cond-name> are generated.
##
## Use SR_VAR_OPT_PKG to generate lists of available modules and features.
##
AC_DEFUN([SR_ARG_OPT_PKG],
[dnl
m4_assert([$# >= 4])[]dnl
AC_REQUIRE([PKG_PROG_PKG_CONFIG])[]dnl
AC_REQUIRE([SR_PKG_CHECK_SUMMARY])[]dnl
AC_REQUIRE([SR_VAR_OPT_PKG])[]dnl
dnl
_SR_ARG_OPT_PKG(m4_expand([AS_TR_SH([$1])]),
	m4_defn([_SR_VAR_OPT_PKG_MODULES]),
	m4_defn([_SR_VAR_OPT_PKG_FEATURES]),
	$@)[]dnl
])

## _SR_ARG_ENABLE_WARNINGS_ONCE
##
## Implementation helper macro of SR_ARG_ENABLE_WARNINGS. Pulled in
## through AC_REQUIRE so that it is only expanded once.
##
m4_define([_SR_ARG_ENABLE_WARNINGS_ONCE],
[dnl
AC_PROVIDE([$0])[]dnl
AC_ARG_ENABLE([warnings],
		[AS_HELP_STRING([[--enable-warnings[=min|max|fatal|no]]],
				[set compile pedantry level [default=max]])],
		[sr_enable_warnings=$enableval],
		[sr_enable_warnings=max])[]dnl
dnl
# Test whether the compiler accepts each flag.  Look at standard output,
# since GCC only shows a warning message if an option is not supported.
sr_check_compile_warning_flags() {
	for sr_flag
	do
		sr_cc_out=`$sr_cc $sr_warning_flags $sr_flag -c "$sr_conftest" 2>&1 || echo failed`
		AS_IF([test "$?$sr_cc_out" = 0],
			[SR_APPEND([sr_warning_flags], [$sr_flag])],
			[AS_ECHO(["$sr_cc: $sr_cc_out"]) >&AS_MESSAGE_LOG_FD])
		rm -f "conftest.[$]{OBJEXT:-o}"
	done
}
])

## SR_ARG_ENABLE_WARNINGS(variable, min-flags, max-flags)
##
## Provide the --enable-warnings configure argument, set to "min" by default.
## <min-flags> and <max-flags> should be space-separated lists of compiler
## warning flags to use with --enable-warnings=min or --enable-warnings=max,
## respectively. Warning level "fatal" is the same as "max" but in addition
## enables -Werror mode.
##
## In order to determine the warning options to use with the C++ compiler,
## call AC_LANG([C++]) first to change the current language. If different
## output variables are used, it is also fine to call SR_ARG_ENABLE_WARNINGS
## repeatedly, once for each language setting.
##
AC_DEFUN([SR_ARG_ENABLE_WARNINGS],
[dnl
m4_assert([$# >= 3])[]dnl
AC_REQUIRE([_SR_ARG_ENABLE_WARNINGS_ONCE])[]dnl
dnl
AS_CASE([$ac_compile],
	[[*'$CXXFLAGS '*]], [sr_lang='C++' sr_cc=$CXX sr_conftest="conftest.[$]{ac_ext:-cc}"],
	[[*'$CFLAGS '*]],   [sr_lang=C sr_cc=$CC sr_conftest="conftest.[$]{ac_ext:-c}"],
	[AC_MSG_ERROR([[current language is neither C nor C++]])])
dnl
AC_MSG_CHECKING([which $sr_lang compiler warning flags to use])
sr_warning_flags=
AC_LANG_CONFTEST([AC_LANG_SOURCE([[
int main(int argc, char** argv) { return (argv != 0) ? argc : 0; }
]])])
AS_CASE([$sr_enable_warnings],
	[no], [],
	[min], [sr_check_compile_warning_flags $2],
	[fatal], [sr_check_compile_warning_flags $3 -Werror],
	[sr_check_compile_warning_flags $3])
rm -f "$sr_conftest"
AC_SUBST([$1], [$sr_warning_flags])
AC_MSG_RESULT([[$]{sr_warning_flags:-none}])[]dnl
])
Commit	Line	Data
24138539 DE	1	## Copyright (c) 2009 Openismus GmbH
	2	## Copyright (c) 2015 Daniel Elstner <daniel.kitta@gmail.com>
	3	##
	4	## This file is part of the sigrok project.
	5	##
	6	## sigrok is free software: you can redistribute it and/or modify it
	7	## under the terms of the GNU General Public License as published by
	8	## the Free Software Foundation, either version 3 of the License, or
	9	## (at your option) any later version.
	10	##
	11	## sigrok is distributed in the hope that it will be useful,
	12	## but WITHOUT ANY WARRANTY; without even the implied warranty of
	13	## MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	14	## GNU General Public License for more details.
	15	##
	16	## You should have received a copy of the GNU General Public License
	17	## along with sigrok. If not, see <http://www.gnu.org/licenses/>.
	18
4cf2f34f	19	#serial 20150823
24138539 DE	20
	21	## SR_APPEND(var-name, [list-sep,] element)
	22	##
	23	## Append the shell word <element> to the shell variable named <var-name>,
	24	## prefixed by <list-sep> unless the list was empty before appending. If
	25	## only two arguments are supplied, <list-sep> defaults to a single space
	26	## character.
	27	##
	28	AC_DEFUN([SR_APPEND],
	29	[dnl
	30	m4_assert([$# >= 2])[]dnl
	31	$1=[$]{$1[}]m4_if([$#], [2], [[$]{$1:+' '}$2], [[$]{$1:+$2}$3])[]dnl
	32	])
	33
	34	## _SR_PKG_VERSION_SET(var-prefix, pkg-name, tag-prefix, base-version, major, minor, [micro])
	35	##
	36	m4_define([_SR_PKG_VERSION_SET],
	37	[dnl
	38	m4_assert([$# >= 6])[]dnl
	39	$1=$4
	40	sr_git_deps=
	41	# Check if we can get revision information from git.
	42	sr_head=`git -C "$srcdir" rev-parse --verify --short HEAD 2>&AS_MESSAGE_LOG_FD`
	43
	44	AS_IF([test "$?" = 0 && test "x$sr_head" != x], [dnl
	45	test ! -f "$srcdir/.git/HEAD" \
	46	\|\| sr_git_deps="$sr_git_deps \$(top_srcdir)/.git/HEAD"
	47
	48	sr_head_name=`git -C "$srcdir" rev-parse --symbolic-full-name HEAD 2>&AS_MESSAGE_LOG_FD`
	49	AS_IF([test "$?" = 0 && test -f "$srcdir/.git/$sr_head_name"],
	50	[sr_git_deps="$sr_git_deps \$(top_srcdir)/.git/$sr_head_name"])
	51
	52	# Append the revision hash unless we are exactly on a tagged release.
	53	git -C "$srcdir" describe --match "$3$4" \
	54	--exact-match >&AS_MESSAGE_LOG_FD 2>&AS_MESSAGE_LOG_FD \
	55	\|\| $1="[$]$1-git-$sr_head"
	56	])
	57	# Use $(wildcard) so that things do not break if for whatever
	58	# reason these files do not exist anymore at make time.
	59	AS_IF([test -n "$sr_git_deps"],
	60	[SR_APPEND([CONFIG_STATUS_DEPENDENCIES], ["\$(wildcard$sr_git_deps)"])])
	61	AC_SUBST([CONFIG_STATUS_DEPENDENCIES])[]dnl
	62	AC_SUBST([$1])[]dnl
	63	dnl
	64	AC_DEFINE([$1_MAJOR], [$5], [Major version number of $2.])[]dnl
	65	AC_DEFINE([$1_MINOR], [$6], [Minor version number of $2.])[]dnl
	66	m4_ifval([$7], [AC_DEFINE([$1_MICRO], [$7], [Micro version number of $2.])])[]dnl
	67	AC_DEFINE_UNQUOTED([$1_STRING], ["[$]$1"], [Version of $2.])[]dnl
	68	])
	69
	70	## SR_PKG_VERSION_SET(var-prefix, version-triple)
	71	##
	72	## Set up substitution variables and macro definitions for the package
	73	## version components. Derive the version suffix from the repository
	74	## revision if possible.
	75	##
	76	## Substitutions: <var-prefix>
	77	## Macro defines: <var-prefix>_{MAJOR,MINOR,MICRO,STRING}
	78	##
	79	AC_DEFUN([SR_PKG_VERSION_SET],
	80	[dnl
	81	m4_assert([$# >= 2])[]dnl
	82	_SR_PKG_VERSION_SET([$1],
	83	m4_defn([AC_PACKAGE_NAME]),
84	m4_defn([AC_PACKAGE_TARNAME])[-],
85	m4_expand([$2]),
86	m4_unquote(m4_split(m4_expand([$2]), [\.])))
87	])
88
89	## _SR_LIB_VERSION_SET(var-prefix, pkg-name, abi-triple, current, revision, age)
90	##
91	m4_define([_SR_LIB_VERSION_SET],
92	[dnl
93	m4_assert([$# >= 6])[]dnl
94	$1=$3
95	AC_SUBST([$1])[]dnl
96	AC_DEFINE([$1_CURRENT], [$4], [Binary version of $2.])[]dnl
97	AC_DEFINE([$1_REVISION], [$5], [Binary revision of $2.])[]dnl
98	AC_DEFINE([$1_AGE], [$6], [Binary age of $2.])[]dnl
99	AC_DEFINE([$1_STRING], ["$3"], [Binary version triple of $2.])[]dnl
100	])
101
102	## SR_LIB_VERSION_SET(var-prefix, abi-triple)
103	##
104	## Set up substitution variables and macro definitions for a library
105	## binary version.
106	##
107	## Substitutions: <var-prefix>
108	## Macro defines: <var-prefix>_{CURRENT,REVISION,AGE,STRING}
109	##
110	AC_DEFUN([SR_LIB_VERSION_SET],
111	[dnl
112	m4_assert([$# >= 1])[]dnl
113	_SR_LIB_VERSION_SET([$1],
114	m4_defn([AC_PACKAGE_NAME]),
115	[$2], m4_unquote(m4_split([$2], [:])))
116	])
117
1bb196e4 DE	118	## _SR_VAR_SUMMARY(tag, var-name, line-leader, align-columns, align-char)
	119	##
	120	m4_define([_SR_VAR_SUMMARY], [dnl
	121	$2=
	122	$1_append() {
	123	sr_aligned=`printf '%.$4s' "[$][1]m4_for([i], [1], [$4],, [$5])"`
	124	$2="[$]{$2}$3$sr_aligned [$]2"'
	125	'
	126	}
	127	])
	128
	129	## SR_VAR_SUMMARY(tag, [var-name = <tag>],
	130	## [line-leader = [ - ]], [align-columns = 32], [align-char = .])
	131	##
	132	## Define a shell function <tag>_append() to be used for aggregating
	133	## a summary of test results in the shell variable <var-name>.
	134	##
	135	AC_DEFUN([SR_VAR_SUMMARY],
	136	[dnl
	137	m4_assert([$# >= 1])[]dnl
	138	_SR_VAR_SUMMARY([$1],
	139	m4_default_quoted([$2], [$1]),
	140	m4_default_quoted([$3], [ - ]),
	141	m4_default_quoted([$4], [32]),
	142	m4_default_quoted([$5], [.]))[]dnl
	143	])
	144
	145	## SR_PKG_CHECK_SUMMARY([var-name = sr_pkg_check_summary],
	146	## [line-leader = [ - ]], [align-columns = 32], [align-char = .])
	147	##
	148	## Prepare for the aggregation of package check results
	149	## in the shell variable <var-name>.
	150	##
	151	AC_DEFUN([SR_PKG_CHECK_SUMMARY],
	152	[SR_VAR_SUMMARY([sr_pkg_check_summary], $@)])
	153
	154	## SR_PKG_CHECK(tag, [collect-var], module...)
	155	##
	156	## Check for each pkg-config <module> in the argument list. <module> may
	157	## include a version constraint.
	158	##
	159	## Output variables: sr_have_<tag>, sr_<tag>_version
	160	##
	161	AC_DEFUN([SR_PKG_CHECK],
	162	[dnl
	163	m4_assert([$# >= 3])[]dnl
	164	AC_REQUIRE([PKG_PROG_PKG_CONFIG])[]dnl
	165	AC_REQUIRE([SR_PKG_CHECK_SUMMARY])[]dnl
	166	dnl
	167	PKG_CHECK_EXISTS([$3], [dnl
	168	sr_have_$1=yes
	169	m4_ifval([$2], [SR_APPEND([$2], ["$3"])
	170	])sr_$1_version=`$PKG_CONFIG --modversion "$3" 2>&AS_MESSAGE_LOG_FD`
	171	sr_pkg_check_summary_append "$3" "$sr_$1_version"[]dnl
	172	], [dnl
	173	sr_pkg_check_summary_append "$3" no
	174	m4_ifval([$4],
	175	[SR_PKG_CHECK([$1], [$2], m4_shift3($@))],
	176	[sr_have_$1=no sr_$1_version=])[]dnl
	177	])
	178	])
	179
	180	## SR_VAR_OPT_PKG([modules-var], [features-var])
	181	##
182	## Enable the collection of SR_ARG_OPT_PKG results into the shell variables
183	## <modules-var> and <features-var>.
184	##
185	AC_DEFUN([SR_VAR_OPT_PKG],
186	[dnl
187	m4_define([_SR_VAR_OPT_PKG_MODULES], [$1])[]dnl
188	m4_define([_SR_VAR_OPT_PKG_FEATURES], [$2])[]dnl
189	m4_ifvaln([$1], [$1=])[]dnl
190	m4_ifvaln([$2], [$2=])[]dnl
191	])
192
193	## _SR_ARG_OPT_PKG(sh-name, [modules-var], [features-var],
194	## opt-name, [cpp-name], [cond-name], module...)
195	##
196	m4_define([_SR_ARG_OPT_PKG],
197	[dnl
198	AC_ARG_WITH([$4], [AS_HELP_STRING([--without-$4],
199	[disable $4 support [default=detect]])])
200	AS_IF([test "x$with_$1" = xno], [sr_have_$1=no],
201	[test "x$sr_have_$1" != xyes],
202	[SR_PKG_CHECK([$1], [$2], m4_shiftn([6], $@))])
203	AS_IF([test "x$with_$1$sr_have_$1" = xyesno],
204	[AC_MSG_ERROR([$4 support requested, but it was not found.])])
205	AS_IF([test "x$sr_have_$1" = xyes], [m4_ifval([$3], [
206	SR_APPEND([$3], ["$4"])])[]m4_ifval([$5], [
207	AC_DEFINE([HAVE_$5], [1], [Whether $4 is available.])
208	AC_DEFINE_UNQUOTED([CONF_$5_VERSION], ["$sr_$1_version"],
209	[Build-time version of $4.])])[]dnl
210	])
211	m4_ifvaln([$6], [AM_CONDITIONAL([$6], [test "x$sr_have_$1" = xyes])])[]dnl
212	])
213
214	## SR_ARG_OPT_PKG(opt-name, [cpp-name], [cond-name], module...)
215	##
216	## Provide a --without-<opt-name> configure option for explicit disabling
217	## of an optional dependency. If not disabled, the availability of the
218	## optional dependency is auto-detected.
219	##
220	## Each pkg-config <module> argument is checked in turn, and the first one
221	## found is selected. On success, the shell variable sr_have_<opt-name>
222	## is set to "yes", otherwise to "no". Optionally, a preprocessor macro
223	## HAVE_<cpp-name> and an Automake conditional <cond-name> are generated.
224	##
225	## Use SR_VAR_OPT_PKG to generate lists of available modules and features.
226	##
227	AC_DEFUN([SR_ARG_OPT_PKG],
228	[dnl
229	m4_assert([$# >= 4])[]dnl
230	AC_REQUIRE([PKG_PROG_PKG_CONFIG])[]dnl
231	AC_REQUIRE([SR_PKG_CHECK_SUMMARY])[]dnl
232	AC_REQUIRE([SR_VAR_OPT_PKG])[]dnl
233	dnl
234	_SR_ARG_OPT_PKG(m4_expand([AS_TR_SH([$1])]),
235	m4_defn([_SR_VAR_OPT_PKG_MODULES]),
236	m4_defn([_SR_VAR_OPT_PKG_FEATURES]),
237	$@)[]dnl
238	])
239
24138539 DE	240	## _SR_ARG_ENABLE_WARNINGS_ONCE
	241	##
	242	## Implementation helper macro of SR_ARG_ENABLE_WARNINGS. Pulled in
	243	## through AC_REQUIRE so that it is only expanded once.
	244	##
	245	m4_define([_SR_ARG_ENABLE_WARNINGS_ONCE],
	246	[dnl
	247	AC_PROVIDE([$0])[]dnl
	248	AC_ARG_ENABLE([warnings],
	249	[AS_HELP_STRING([[--enable-warnings[=min\|max\|fatal\|no]]],
4cf2f34f	250	[set compile pedantry level [default=max]])],
24138539	251	[sr_enable_warnings=$enableval],
4cf2f34f	252	[sr_enable_warnings=max])[]dnl
24138539 DE	253	dnl
	254	# Test whether the compiler accepts each flag. Look at standard output,
	255	# since GCC only shows a warning message if an option is not supported.
	256	sr_check_compile_warning_flags() {
	257	for sr_flag
	258	do
	259	sr_cc_out=`$sr_cc $sr_warning_flags $sr_flag -c "$sr_conftest" 2>&1 \|\| echo failed`
	260	AS_IF([test "$?$sr_cc_out" = 0],
	261	[SR_APPEND([sr_warning_flags], [$sr_flag])],
	262	[AS_ECHO(["$sr_cc: $sr_cc_out"]) >&AS_MESSAGE_LOG_FD])
	263	rm -f "conftest.[$]{OBJEXT:-o}"
	264	done
	265	}
	266	])
	267
	268	## SR_ARG_ENABLE_WARNINGS(variable, min-flags, max-flags)
	269	##
	270	## Provide the --enable-warnings configure argument, set to "min" by default.
	271	## <min-flags> and <max-flags> should be space-separated lists of compiler
	272	## warning flags to use with --enable-warnings=min or --enable-warnings=max,
	273	## respectively. Warning level "fatal" is the same as "max" but in addition
	274	## enables -Werror mode.
	275	##
	276	## In order to determine the warning options to use with the C++ compiler,
	277	## call AC_LANG([C++]) first to change the current language. If different
	278	## output variables are used, it is also fine to call SR_ARG_ENABLE_WARNINGS
	279	## repeatedly, once for each language setting.
	280	##
	281	AC_DEFUN([SR_ARG_ENABLE_WARNINGS],
	282	[dnl
	283	m4_assert([$# >= 3])[]dnl
	284	AC_REQUIRE([_SR_ARG_ENABLE_WARNINGS_ONCE])[]dnl
	285	dnl
	286	AS_CASE([$ac_compile],
	287	[['$CXXFLAGS ']], [sr_lang='C++' sr_cc=$CXX sr_conftest="conftest.[$]{ac_ext:-cc}"],
	288	[['$CFLAGS ']], [sr_lang=C sr_cc=$CC sr_conftest="conftest.[$]{ac_ext:-c}"],
	289	[AC_MSG_ERROR([[current language is neither C nor C++]])])
	290	dnl
	291	AC_MSG_CHECKING([which $sr_lang compiler warning flags to use])
	292	sr_warning_flags=
	293	AC_LANG_CONFTEST([AC_LANG_SOURCE([[
	294	int main(int argc, char** argv) { return (argv != 0) ? argc : 0; }
	295	]])])
	296	AS_CASE([$sr_enable_warnings],
	297	[no], [],
4cf2f34f	298	[min], [sr_check_compile_warning_flags $2],
24138539	299	[fatal], [sr_check_compile_warning_flags $3 -Werror],
4cf2f34f	300	[sr_check_compile_warning_flags $3])
24138539 DE	301	rm -f "$sr_conftest"
	302	AC_SUBST([$1], [$sr_warning_flags])
	303	AC_MSG_RESULT([[$]{sr_warning_flags:-none}])[]dnl
	304	])