1 # ===========================================================================
2 # https://www.gnu.org/software/autoconf-archive/ax_prefix_config_h.html
3 # ===========================================================================
7 # AX_PREFIX_CONFIG_H [(OUTPUT-HEADER [,PREFIX [,ORIG-HEADER]])]
11 # Generate an installable config.h.
13 # A package should not normally install its config.h as a system header,
14 # but if it must, this macro can be used to avoid namespace pollution by
15 # making a copy of config.h with a prefix added to all the macro names.
17 # Each "#define SOMEDEF" line of the configuration header has the given
18 # prefix added, in the same case as the first character of the macro name.
22 # OUTPUT-HEADER = $PACKAGE-config.h
24 # ORIG-HEADER, from AM_CONFIG_HEADER(config.h)
26 # Your configure.ac script should contain both macros in this order.
30 # AC_INIT(config.h.in) # config.h.in as created by "autoheader"
31 # AM_INIT_AUTOMAKE(testpkg, 0.1.1) # makes #undef VERSION and PACKAGE
32 # AM_CONFIG_HEADER(config.h) # prep config.h from config.h.in
33 # AX_PREFIX_CONFIG_H(mylib/_config.h) # prep mylib/_config.h from it..
34 # AC_MEMORY_H # makes "#undef NEED_MEMORY_H"
35 # AC_C_CONST_H # makes "#undef const"
36 # AC_OUTPUT(Makefile) # creates the "config.h" now
37 # # and also mylib/_config.h
39 # If the argument to AX_PREFIX_CONFIG_H would have been omitted then the
40 # default output file would have been called simply "testpkg-config.h",
41 # but even under the name "mylib/_config.h" it contains prefix-defines
44 # #ifndef TESTPKG_VERSION
45 # #define TESTPKG_VERSION "0.1.1"
47 # #ifndef TESTPKG_NEED_MEMORY_H
48 # #define TESTPKG_NEED_MEMORY_H 1
50 # #ifndef _testpkg_const
51 # #define _testpkg_const _const
54 # and this "mylib/_config.h" can be installed along with other header
55 # files, which is most convenient when creating a shared library (that has
56 # some headers) whose functionality depends on features detected at
57 # compile-time. No need to invent some "mylib-confdefs.h.in" manually.
59 # Note that some AC_DEFINEs that end up in the config.h file are actually
60 # self-referential - e.g. AC_C_INLINE, AC_C_CONST, and the AC_TYPE_OFF_T
61 # say that they "will define inline|const|off_t if the system does not do
62 # it by itself". You might want to clean up about these - consider an
63 # extra mylib/conf.h that reads something like:
65 # #include <mylib/_config.h>
66 # #ifndef _testpkg_const
67 # #define _testpkg_const const
70 # and then start using _testpkg_const in the header files. That is also a
71 # good thing to differentiate whether some library-user has starting to
72 # take up with a different compiler, so perhaps it could read something
76 # #include <mylib/_msvc.h>
78 # #include <mylib/_config.h>
80 # #ifndef _testpkg_const
81 # #define _testpkg_const const
86 # Copyright (c) 2014 Reuben Thomas <rrt@sc3d.org>
87 # Copyright (c) 2008 Guido U. Draheim <guidod@gmx.de>
88 # Copyright (c) 2008 Marten Svantesson
89 # Copyright (c) 2008 Gerald Point <Gerald.Point@labri.fr>
91 # This program is free software; you can redistribute it and/or modify it
92 # under the terms of the GNU General Public License as published by the
93 # Free Software Foundation; either version 3 of the License, or (at your
94 # option) any later version.
96 # This program is distributed in the hope that it will be useful, but
97 # WITHOUT ANY WARRANTY; without even the implied warranty of
98 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
99 # Public License for more details.
101 # You should have received a copy of the GNU General Public License along
102 # with this program. If not, see <https://www.gnu.org/licenses/>.
104 # As a special exception, the respective Autoconf Macro's copyright owner
105 # gives unlimited permission to copy, distribute and modify the configure
106 # scripts that are the output of Autoconf when processing the Macro. You
107 # need not follow the terms of the GNU General Public License when using
108 # or distributing such scripts, even though portions of the text of the
109 # Macro appear in them. The GNU General Public License (GPL) does govern
110 # all other use of the material that constitutes the Autoconf Macro.
112 # This special exception to the GPL applies to versions of the Autoconf
113 # Macro released by the Autoconf Archive. When you make and distribute a
114 # modified version of the Autoconf Macro, you may extend this special
115 # exception to the GPL to apply to your modified version as well.
119 AC_DEFUN([AX_PREFIX_CONFIG_H],[dnl
121 AC_BEFORE([AC_CONFIG_HEADERS],[$0])dnl
122 AC_CONFIG_COMMANDS(m4_default([$1], [$PACKAGE-config.h]),[dnl
123 AS_VAR_PUSHDEF([_OUT],[ac_prefix_conf_OUT])dnl
124 AS_VAR_PUSHDEF([_DEF],[ac_prefix_conf_DEF])dnl
125 AS_VAR_PUSHDEF([_PKG],[ac_prefix_conf_PKG])dnl
126 AS_VAR_PUSHDEF([_LOW],[ac_prefix_conf_LOW])dnl
127 AS_VAR_PUSHDEF([_UPP],[ac_prefix_conf_UPP])dnl
128 AS_VAR_PUSHDEF([_INP],[ac_prefix_conf_INP])dnl
129 m4_pushdef([_script],[conftest.prefix])dnl
130 m4_pushdef([_symbol],[m4_cr_Letters[]m4_cr_digits[]_])dnl
131 _OUT=`echo m4_default([$1], [$PACKAGE-config.h])`
132 _DEF=`echo _$_OUT | sed -e "y:m4_cr_letters:m4_cr_LETTERS[]:" -e "s/@<:@^m4_cr_Letters@:>@/_/g"`
133 _PKG=`echo m4_default([$2], [$PACKAGE])`
134 _LOW=`echo _$_PKG | sed -e "y:m4_cr_LETTERS-:m4_cr_letters[]_:"`
135 _UPP=`echo $_PKG | sed -e "y:m4_cr_letters-:m4_cr_LETTERS[]_:" -e "/^@<:@m4_cr_digits@:>@/s/^/_/"`
136 _INP=`echo "$3" | sed -e 's/ *//'`
137 if test ".$_INP" = "."; then
138 for ac_file in : $CONFIG_HEADERS; do test "_$ac_file" = _: && continue
140 *.h) _INP=$ac_file ;;
143 test ".$_INP" != "." && break
146 if test ".$_INP" = "."; then
148 */*) _INP=`basename "$_OUT"`
150 *-*) _INP=`echo "$_OUT" | sed -e "s/@<:@_symbol@:>@*-//"`
156 if test -z "$_PKG" ; then
157 AC_MSG_ERROR([no prefix for _PREFIX_PKG_CONFIG_H])
159 if test ! -f "$_INP" ; then if test -f "$srcdir/$_INP" ; then
162 AC_MSG_NOTICE(creating $_OUT - prefix $_UPP for $_INP defines)
163 if test -f $_INP ; then
164 AS_ECHO(["s/^@%:@undef *\\(@<:@m4_cr_LETTERS[]_@:>@\\)/@%:@undef $_UPP""_\\1/"]) > _script
165 AS_ECHO(["s/^@%:@undef *\\(@<:@m4_cr_letters@:>@\\)/@%:@undef $_LOW""_\\1/"]) >> _script
166 AS_ECHO(["s/^@%:@def[]ine *\\(@<:@m4_cr_LETTERS[]_@:>@@<:@_symbol@:>@*\\)\\(.*\\)/@%:@ifndef $_UPP""_\\1\\"]) >> _script
167 AS_ECHO(["@%:@def[]ine $_UPP""_\\1\\2\\"]) >> _script
168 AS_ECHO(["@%:@endif/"]) >> _script
169 AS_ECHO(["s/^@%:@def[]ine *\\(@<:@m4_cr_letters@:>@@<:@_symbol@:>@*\\)\\(.*\\)/@%:@ifndef $_LOW""_\\1\\"]) >> _script
170 AS_ECHO(["@%:@define $_LOW""_\\1\\2\\"]) >> _script
171 AS_ECHO(["@%:@endif/"]) >> _script
172 # now executing _script on _DEF input to create _OUT output file
173 echo "@%:@ifndef $_DEF" >$tmp/pconfig.h
174 echo "@%:@def[]ine $_DEF 1" >>$tmp/pconfig.h
175 echo ' ' >>$tmp/pconfig.h
176 echo /'*' $_OUT. Generated automatically at end of configure. '*'/ >>$tmp/pconfig.h
178 sed -f _script $_INP >>$tmp/pconfig.h
179 echo ' ' >>$tmp/pconfig.h
180 echo '/* once:' $_DEF '*/' >>$tmp/pconfig.h
181 echo "@%:@endif" >>$tmp/pconfig.h
182 if cmp -s $_OUT $tmp/pconfig.h 2>/dev/null; then
183 AC_MSG_NOTICE([$_OUT is unchanged])
185 ac_dir=`AS_DIRNAME(["$_OUT"])`
186 AS_MKDIR_P(["$ac_dir"])
188 mv $tmp/pconfig.h "$_OUT"
191 AC_MSG_ERROR([input file $_INP does not exist - skip generating $_OUT])
195 m4_popdef([_symbol])dnl
196 m4_popdef([_script])dnl
197 AS_VAR_POPDEF([_INP])dnl
198 AS_VAR_POPDEF([_UPP])dnl
199 AS_VAR_POPDEF([_LOW])dnl
200 AS_VAR_POPDEF([_PKG])dnl
201 AS_VAR_POPDEF([_DEF])dnl
202 AS_VAR_POPDEF([_OUT])dnl
203 ],[PACKAGE="$PACKAGE"])])