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      1 # ===========================================================================
      2 #    http://www.gnu.org/software/autoconf-archive/ax_prefix_config_h.html
      3 # ===========================================================================
      4 #
      5 # SYNOPSIS
      6 #
      7 #   AX_PREFIX_CONFIG_H [(OUTPUT-HEADER [,PREFIX [,ORIG-HEADER]])]
      8 #
      9 # DESCRIPTION
     10 #
     11 #   Generate an installable config.h.
     12 #
     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.
     16 #
     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.
     19 #
     20 #   Defaults:
     21 #
     22 #     OUTPUT-HEADER = $PACKAGE-config.h
     23 #     PREFIX = $PACKAGE
     24 #     ORIG-HEADER, from AM_CONFIG_HEADER(config.h)
     25 #
     26 #   Your configure.ac script should contain both macros in this order.
     27 #
     28 #   Example:
     29 #
     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
     38 #
     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
     42 #   like
     43 #
     44 #     #ifndef TESTPKG_VERSION
     45 #     #define TESTPKG_VERSION "0.1.1"
     46 #     #endif
     47 #     #ifndef TESTPKG_NEED_MEMORY_H
     48 #     #define TESTPKG_NEED_MEMORY_H 1
     49 #     #endif
     50 #     #ifndef _testpkg_const
     51 #     #define _testpkg_const _const
     52 #     #endif
     53 #
     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.
     58 #
     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:
     64 #
     65 #     #include <mylib/_config.h>
     66 #     #ifndef _testpkg_const
     67 #     #define _testpkg_const const
     68 #     #endif
     69 #
     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
     73 #   like this:
     74 #
     75 #     #ifdef _MSC_VER
     76 #     #include <mylib/_msvc.h>
     77 #     #else
     78 #     #include <mylib/_config.h>
     79 #     #endif
     80 #     #ifndef _testpkg_const
     81 #     #define _testpkg_const const
     82 #     #endif
     83 #
     84 # LICENSE
     85 #
     86 #   Copyright (c) 2014 Reuben Thomas <rrt (a] sc3d.org>
     87 #   Copyright (c) 2008 Guido U. Draheim <guidod (a] gmx.de>
     88 #   Copyright (c) 2008 Marten Svantesson
     89 #   Copyright (c) 2008 Gerald Point <Gerald.Point (a] labri.fr>
     90 #
     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.
     95 #
     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.
    100 #
    101 #   You should have received a copy of the GNU General Public License along
    102 #   with this program. If not, see <http://www.gnu.org/licenses/>.
    103 #
    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.
    111 #
    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.
    116 
    117 #serial 15
    118 
    119 AC_DEFUN([AX_PREFIX_CONFIG_H],[dnl
    120 AC_PREREQ([2.62])
    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
    139      case "$ac_file" in
    140         *.h) _INP=$ac_file ;;
    141         *)
    142      esac
    143      test ".$_INP" != "." && break
    144    done
    145 fi
    146 if test ".$_INP" = "."; then
    147    case "$_OUT" in
    148       */*) _INP=`basename "$_OUT"`
    149       ;;
    150       *-*) _INP=`echo "$_OUT" | sed -e "s/@<:@_symbol@:>@*-//"`
    151       ;;
    152       *) _INP=config.h
    153       ;;
    154    esac
    155 fi
    156 if test -z "$_PKG" ; then
    157    AC_MSG_ERROR([no prefix for _PREFIX_PKG_CONFIG_H])
    158 else
    159   if test ! -f "$_INP" ; then if test -f "$srcdir/$_INP" ; then
    160      _INP="$srcdir/$_INP"
    161   fi fi
    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
    177 
    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])
    184     else
    185       ac_dir=`AS_DIRNAME(["$_OUT"])`
    186       AS_MKDIR_P(["$ac_dir"])
    187       rm -f "$_OUT"
    188       mv $tmp/pconfig.h "$_OUT"
    189     fi
    190   else
    191     AC_MSG_ERROR([input file $_INP does not exist - skip generating $_OUT])
    192   fi
    193   rm -f conftest.*
    194 fi
    195 m4_popdef([_symbol])dnl
    196 m4_popdef([_script])dnl
    197 AS_VAR_POPDEF([_INP])dnl
    198 AS_VAR_POPDEF([_UPP])dnl
    199 AS_VAR_POPDEF([_LOW])dnl
    200 AS_VAR_POPDEF([_PKG])dnl
    201 AS_VAR_POPDEF([_DEF])dnl
    202 AS_VAR_POPDEF([_OUT])dnl
    203 ],[PACKAGE="$PACKAGE"])])
    204