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) 2012 Brian Aker <brian@tangent.org>
  36 #   Copyright (c) 2010 Diego Elio Petteno` <flameeyes@gmail.com>
  37 #
  38 #   This program is free software: you can redistribute it and/or modify it
  39 #   under the terms of the GNU General Public License as published by the
  40 #   Free Software Foundation, either version 3 of the License, or (at your
  41 #   option) any later version.
  42 #
  43 #   This program is distributed in the hope that it will be useful, but
  44 #   WITHOUT ANY WARRANTY; without even the implied warranty of
  45 #   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General
  46 #   Public License for more details.
  47 #
  48 #   You should have received a copy of the GNU General Public License along
  49 #   with this program. If not, see <http://www.gnu.org/licenses/>.
  50 #
  51 #   As a special exception, the respective Autoconf Macro's copyright owner
  52 #   gives unlimited permission to copy, distribute and modify the configure
  53 #   scripts that are the output of Autoconf when processing the Macro. You
  54 #   need not follow the terms of the GNU General Public License when using
  55 #   or distributing such scripts, even though portions of the text of the
  56 #   Macro appear in them. The GNU General Public License (GPL) does govern
  57 #   all other use of the material that constitutes the Autoconf Macro.
  58 #
  59 #   This special exception to the GPL applies to versions of the Autoconf
  60 #   Macro released by the Autoconf Archive. When you make and distribute a
  61 #   modified version of the Autoconf Macro, you may extend this special
  62 #   exception to the GPL to apply to your modified version as well.
  63
  64 #serial 7
  65
  66 AC_DEFUN([AX_CHECK_LIBRARY],
  67     [AC_ARG_VAR($1[_CPPFLAGS],[C preprocessor flags for ]$1[ headers])
  68     AC_ARG_VAR($1[_LDFLAGS],[linker flags for ]$1[ libraries])
  69
  70     AC_CACHE_VAL(AS_TR_SH([ax_cv_have_]$1),
  71       [AX_SAVE_FLAGS
  72
  73       AS_IF([test "x$]$1[_CPPFLAGS" != "x"],
  74         [CPPFLAGS="$CPPFLAGS $]$1[_CPPFLAGS"])
  75
  76       AS_IF([test "x$]$1[_LDFLAGS" != "x"],
  77         [LDFLAGS="$LDFLAGS $]$1[_LDFLAGS"])
  78
  79       AC_CHECK_HEADER($2, [
  80         AC_CHECK_LIB($3, [main],
  81           [AS_TR_SH([ax_cv_have_]$1)=yes],
  82           [AS_TR_SH([ax_cv_have_]$1)=no])
  83         ], [AS_TR_SH([ax_cv_have_]$1)=no])
  84
  85       AX_RESTORE_FLAGS
  86       ])
  87
  88     AS_IF([test "$]AS_TR_SH([ax_cv_have_]$1)[" = "yes"],
  89         [AC_DEFINE([HAVE_]$1, [1], [Define to 1 if ]$1[ is found])
  90         AC_SUBST($1[_CPPFLAGS])
  91         AC_SUBST($1[_LDFLAGS])
  92         AC_SUBST($1[_LIB],[-l]$3)
  93         ifelse([$4], , :, [$4])],
  94         [ifelse([$5], , :, [$5])])
  95     ])