m4/libltdl-external.m4

   1 dnl Autoconf macro for an always external libltdl
   2 dnl       Copyright (C) 2009 Heikki Lindholm
   3 dnl
   4 dnl This file is free software; as a special exception the author gives
   5 dnl unlimited permission to copy and/or distribute it, with or without
   6 dnl modifications, as long as this notice is preserved.
   7 dnl
   8 dnl This file is distributed in the hope that it will be useful, but
   9 dnl WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
  10 dnl implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
  11
  12 dnl AM_PATH_LIBLTDL(
  13 dnl  [CHECK-SYMBOLS, [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]])
  14 dnl
  15 AC_DEFUN([AM_PATH_LIBLTDL],
  16 [ AC_ARG_WITH(libltdl-prefix,
  17             AC_HELP_STRING([--with-libltdl-prefix=PFX],
  18                            [prefix where libltdl is installed (optional)]),
  19      libltdl_prefix="$withval", libltdl_prefix="")
  20   ltdl_save_CPPFLAGS="$CPPFLAGS"
  21   ltdl_save_LDFLAGS="$LDFLAGS"
  22   if test x$libltdl_prefix != x ; then
  23     CPPFLAGS="-I$libltdl_prefix/include $CPPFLAGS"
  24     LDFLAGS="-L$libltdl_prefix/lib -lltdl $LDFLAGS"
  25   else
  26     if test x"$LIBLTDL" = x ; then
  27       LIBLTDL="-lltdl"
  28     fi
  29     CPPFLAGS="$LTDLINCL $CPPFLAGS"
  30     LDFLAGS="$LIBLTDL $LDFLAGS"
  31   fi
  32
  33   symbols_to_check=ifelse([$1], ,"ltdl_dlopen","$1")
  34   ltdl_found=yes
  35   AC_CHECK_HEADER([ltdl.h],
  36     [
  37     for sym in $symbols_to_check
  38     do
  39       AC_CHECK_DECL([$sym],
  40         [AC_LINK_IFELSE(AC_LANG_CALL([], [$sym]),
  41           [ltdl_found=yes],
  42           [ltdl_found=no])],
  43         [ltdl_found=no],
  44         [AC_INCLUDES_DEFAULT
  45          #include <ltdl.h>])
  46     done
  47     ],
  48     [ltdl_found=no],
  49     [AC_INCLUDES_DEFAULT]
  50   )
  51
  52   if test x$libltdl_prefix != x ; then
  53     LTDLINCL="-I$libltdl_prefix/include"
  54     LIBLTDL="-L$libltdl_prefix/lib -lltdl"
  55   else
  56     if test x"$LIBLTDL" = x ; then
  57       LIBLTDL="-lltdl"
  58     fi
  59   fi
  60   CPPFLAGS="$ltdl_save_CPPFLAGS"
  61   LDFLAGS="$ltdl_save_LDFLAGS"
  62
  63   AC_MSG_CHECKING(for libltdl with symbols $symbols_to_check)
  64   if test $ltdl_found = yes; then
  65     AC_MSG_RESULT(yes)
  66     ifelse([$2], , :, [$2])
  67   else
  68     LTDLINCL=""
  69     LIBLTDL=""
  70     AC_MSG_RESULT(no)
  71     ifelse([$3], , :, [$3])
  72   fi
  73   AC_SUBST(LTDLINCL)
  74   AC_SUBST(LIBLTDL)
  75 ])