X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=m4%2Fsigrok.m4;h=2d0d70fc0af83da629ec5f21e3dc7a9a85e6dee6;hb=e5d953b5592c1ca2af9a0f64f2dfc817a931e59a;hp=875bd1633cf4998c329d2695a135b21dedb00b3a;hpb=b84a733105eea68cbc568850eba20bd571debad7;p=libsigrok.git

diff --git a/m4/sigrok.m4 b/m4/sigrok.m4
index 875bd163..2d0d70fc 100644
--- a/m4/sigrok.m4
+++ b/m4/sigrok.m4
@@ -1,22 +1,24 @@
-## 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
+## Copyright (C) 2009 Openismus GmbH
+## Copyright (C) 2015 Daniel Elstner <daniel.kitta@gmail.com>
+##
+## This program 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,
+## This program 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
+## 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/>.
+## along with this program.  If not, see <http://www.gnu.org/licenses/>.
+##
 
-#serial 20150823
+#serial 20150825
 
 ## SR_APPEND(var-name, [list-sep,] element)
 ##
@@ -31,6 +33,19 @@ m4_assert([$# >= 2])[]dnl
 $1=[$]{$1[}]m4_if([$#], [2], [[$]{$1:+' '}$2], [[$]{$1:+$2}$3])[]dnl
 ])
 
+## SR_PREPEND(var-name, [list-sep,] element)
+##
+## Prepend the shell word <element> to the shell variable named <var-name>,
+## suffixed by <list-sep> unless the list was empty before prepending. If
+## only two arguments are supplied, <list-sep> defaults to a single space
+## character.
+##
+AC_DEFUN([SR_PREPEND],
+[dnl
+m4_assert([$# >= 2])[]dnl
+$1=m4_if([$#], [2], [$2[$]{$1:+' '}], [$3[$]{$1:+$2}])[$]$1[]dnl
+])
+
 ## _SR_PKG_VERSION_SET(var-prefix, pkg-name, tag-prefix, base-version, major, minor, [micro])
 ##
 m4_define([_SR_PKG_VERSION_SET],
@@ -115,6 +130,24 @@ _SR_LIB_VERSION_SET([$1],
 	[$2], m4_unquote(m4_split([$2], [:])))
 ])
 
+## SR_SEARCH_LIBS(libs-var, function, search-libs,
+##                [action-if-found], [action-if-not-found], [other-libs])
+##
+## Same as AC_SEARCH_LIBS, except that the result is prepended
+## to <libs-var> instead of LIBS. Calls AC_SUBST on <libs-var>.
+##
+AC_DEFUN([SR_SEARCH_LIBS],
+[dnl
+m4_assert([$# >= 3])[]dnl
+sr_sl_save_LIBS=$LIBS
+AC_SEARCH_LIBS([$2], [$3],,, m4_join([$6], [[$]$1]))
+LIBS=$sr_sl_save_LIBS
+AS_CASE([$ac_cv_search_$2], [no*],,
+	[SR_PREPEND([$1], [$ac_cv_search_$2])])
+m4_ifvaln([$4$5], [AS_IF([test "x$ac_cv_search_$2" = xno], [$5], [$4])])[]dnl
+AC_SUBST([$1])[]dnl
+])
+
 ## _SR_VAR_SUMMARY(tag, var-name, line-leader, align-columns, align-char)
 ##
 m4_define([_SR_VAR_SUMMARY], [dnl
@@ -257,7 +290,8 @@ do
 	test "x$sr_ccf_result" = xno || break
 done
 CPPFLAGS=$sr_ccf_save_CPPFLAGS
-SR_APPEND([$1], [$sr_ccf_result])
+AS_IF([test "x$sr_ccf_result" != xno],
+	[SR_APPEND([$1], [$sr_ccf_result])])
 AC_MSG_RESULT([$sr_ccf_result])
 AC_SUBST([$1])
 ])