git.m6w6.name Git - m6w6/libmemcached/blob - m4/ax_check_library.m4

   1 # ===========================================================================
   2 #     http://www.gnu.org/software/autoconf-archive/ax_check_library.html
   3 # ===========================================================================
   4 #
   5 # SYNOPSIS
   6 #
   7 #   AX_CHECK_LIBRARY(VARIABLE-PREFIX, HEADER-FILE, LIBRARY-FILE,
   8 #                    [ACTION-IF-FOUND], [ACTION-IF-NOT_FOUND])
   9 #
  10 # DESCRIPTION
  11 #
  12 #   Provides a generic test for a given library, similar in concept to the
  13 #   PKG_CHECK_MODULES macro used by pkg-config.
  14 #
  15 #   Most simplest libraries can be checked against simply through the
  16 #   presence of a header file and a library to link to. This macro allows to
  17 #   wrap around the test so that it doesn't have to be recreated each time.
  18 #
  19 #   Rather than define --with-$LIBRARY arguments, it uses variables in the
  20 #   same way that PKG_CHECK_MODULES does. It doesn't, though, use the same
  21 #   names, since you shouldn't provide a value for LIBS or CFLAGS but rather
  22 #   for LDFLAGS and CPPFLAGS, to tell the linker and compiler where to find
  23 #   libraries and headers respectively.
  24 #
  25 #   If the library is find, HAVE_PREFIX is defined, and in all cases
  26 #   PREFIX_LDFLAGS and PREFIX_CPPFLAGS are substituted.
  27 #
  28 #   Example:
  29 #
  30 #     AX_CHECK_LIBRARY([LIBEVENT], [event.h], [event], [],
  31 #                      [AC_MSG_ERROR([Unable to find libevent])])
  32 #
  33 # LICENSE
  34 #
  35 #   Copyright (c) 2010 Diego Elio Petteno` <flameeyes@gmail.com>
  36 #
  37 #   This program is free software: you can redistribute it and/or modify it
  38 #   under the terms of the GNU General Public License as published by the
  39 #   Free Software Foundation, either version 3 of the License, or (at your
  40 #   option) any later version.
  41 #
  42 #   This program is distributed in the hope that it will be useful, but
  43 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  44 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  45 #   Public License for more details.
  46 #
  47 #   You should have received a copy of the GNU General Public License along
  48 #   with this program. If not, see <http://www.gnu.org/licenses/>.
  49 #
  50 #   As a special exception, the respective Autoconf Macro's copyright owner
  51 #   gives unlimited permission to copy, distribute and modify the configure
  52 #   scripts that are the output of Autoconf when processing the Macro. You
  53 #   need not follow the terms of the GNU General Public License when using
  54 #   or distributing such scripts, even though portions of the text of the
  55 #   Macro appear in them. The GNU General Public License (GPL) does govern
  56 #   all other use of the material that constitutes the Autoconf Macro.
  57 #
  58 #   This special exception to the GPL applies to versions of the Autoconf
  59 #   Macro released by the Autoconf Archive. When you make and distribute a
  60 #   modified version of the Autoconf Macro, you may extend this special
  61 #   exception to the GPL to apply to your modified version as well.
  62
  63 #serial 4
  64
  65 AC_DEFUN([AX_CHECK_LIBRARY], [
  66   AC_ARG_VAR($1[_CPPFLAGS], [C preprocessor flags for ]$1[ headers])
  67   AC_ARG_VAR($1[_LDFLAGS], [linker flags for ]$1[ libraries])
  68
  69   AC_CACHE_VAL(AS_TR_SH([ax_cv_have_]$1),
  70     [save_CPPFLAGS="$CPPFLAGS"
  71      save_LDFLAGS="$LDFLAGS"
  72      save_LIBS="$LIBS"
  73
  74      AS_IF([test "x$]$1[_CPPFLAGS" != "x"],
  75        [CPPFLAGS="$CPPFLAGS $]$1[_CPPFLAGS"])
  76
  77      AS_IF([test "x$]$1[_LDFLAGS" != "x"],
  78        [LDFLAGS="$LDFLAGS $]$1[_LDFLAGS"])
  79
  80      AC_CHECK_HEADER($2, [
  81        AC_CHECK_LIB($3, [main],
  82          [AS_TR_SH([ax_cv_have_]$1)=yes],
  83          [AS_TR_SH([ax_cv_have_]$1)=no])
  84      ], [AS_TR_SH([ax_cv_have_]$1)=no])
  85
  86      CPPFLAGS="$save_CPPFLAGS"
  87      LDFLAGS="$save_LDFLAGS"
  88      LIBS="$save_LIBS"
  89     ])
  90
  91   AS_IF([test "$]AS_TR_SH([ax_cv_have_]$1)[" = "yes"],
  92     AC_DEFINE([HAVE_]$1, [1], [Define to 1 if ]$1[ is found])
  93       m4_ifval( m4_normalize([$4]), [$4]),
  94     m4_ifval( m4_normalize([$5]), [$5]))
  95 ])