# Configure path for the GNU Scientific Library

# Christopher R. Gabriel <cgabriel@linux.it>, April 2000

AC_DEFUN([AX_PATH_GSL],

[

AC_ARG_WITH(gsl-prefix,[  --with-gsl-prefix=PFX   Prefix where GSL is installed (optional)],

            gsl_prefix="$withval", gsl_prefix="")

AC_ARG_WITH(gsl-exec-prefix,[  --with-gsl-exec-prefix=PFX Exec prefix where GSL is installed (optional)],

            gsl_exec_prefix="$withval", gsl_exec_prefix="")

AC_ARG_ENABLE(gsltest, [  --disable-gsltest       Do not try to compile and run a test GSL program],

		    , enable_gsltest=yes)

  if test "x${GSL_CONFIG+set}" != xset ; then

     if test "x$gsl_prefix" != x ; then

         GSL_CONFIG="$gsl_prefix/bin/gsl-config"

     fi

     if test "x$gsl_exec_prefix" != x ; then

        GSL_CONFIG="$gsl_exec_prefix/bin/gsl-config"

     fi

  fi

  AC_PATH_PROG(GSL_CONFIG, gsl-config, no)

  min_gsl_version=ifelse([$1], ,0.2.5,$1)

  AC_MSG_CHECKING(for GSL - version >= $min_gsl_version)

  no_gsl=""

  if test "$GSL_CONFIG" = "no" ; then

    no_gsl=yes

  else

    GSL_CFLAGS=`$GSL_CONFIG --cflags`

    GSL_LIBS=`$GSL_CONFIG --libs`

    gsl_major_version=`$GSL_CONFIG --version | \

           sed 's/^\([[0-9]]*\).*/\1/'`

    if test "x${gsl_major_version}" = "x" ; then

       gsl_major_version=0

    fi

    gsl_minor_version=`$GSL_CONFIG --version | \

           sed 's/^\([[0-9]]*\)\.\{0,1\}\([[0-9]]*\).*/\2/'`

    if test "x${gsl_minor_version}" = "x" ; then

       gsl_minor_version=0

    fi

    gsl_micro_version=`$GSL_CONFIG --version | \

           sed 's/^\([[0-9]]*\)\.\{0,1\}\([[0-9]]*\)\.\{0,1\}\([[0-9]]*\).*/\3/'`

    if test "x${gsl_micro_version}" = "x" ; then

       gsl_micro_version=0

    fi

    if test "x$enable_gsltest" = "xyes" ; then

      ac_save_CFLAGS="$CFLAGS"

      ac_save_LIBS="$LIBS"

      CFLAGS="$CFLAGS $GSL_CFLAGS"

      LIBS="$LIBS $GSL_LIBS"

      rm -f conf.gsltest

      AC_TRY_RUN([

#include <stdio.h>

#include <stdlib.h>

#include <string.h>

char* my_strdup (const char *str);

char*

my_strdup (const char *str)

{

  char *new_str;

  if (str)

    {

      new_str = (char *)malloc ((strlen (str) + 1) * sizeof(char));

      strcpy (new_str, str);

    }

  else

    new_str = NULL;

  return new_str;

}

int main (void)

{

  int major = 0, minor = 0, micro = 0;

  int n;

  char *tmp_version;

  system ("touch conf.gsltest");

  /* HP/UX 9 (%@#!) writes to sscanf strings */

  tmp_version = my_strdup("$min_gsl_version");

  n = sscanf(tmp_version, "%d.%d.%d", &major, &minor, &micro) ;

  if (n != 2 && n != 3) {

     printf("%s, bad version string\n", "$min_gsl_version");

     exit(1);

   }

   if (($gsl_major_version > major) ||

      (($gsl_major_version == major) && ($gsl_minor_version > minor)) ||

      (($gsl_major_version == major) && ($gsl_minor_version == minor) && ($gsl_micro_version >= micro)))

     { 

       exit(0);

     }   

   else

     {

       exit(1);

     }

}

],, no_gsl=yes,[echo $ac_n "cross compiling; assumed OK... $ac_c"])

       CFLAGS="$ac_save_CFLAGS"

       LIBS="$ac_save_LIBS"

     fi

  fi

  if test "x$no_gsl" = x ; then

     AC_MSG_RESULT(yes)

     ifelse([$2], , :, [$2])     

  else

     AC_MSG_RESULT(no)

     if test "$GSL_CONFIG" = "no" ; then

       echo "*** The gsl-config script installed by GSL could not be found"

       echo "*** If GSL was installed in PREFIX, make sure PREFIX/bin is in"

       echo "*** your path, or set the GSL_CONFIG environment variable to the"

       echo "*** full path to gsl-config."

     else

       if test -f conf.gsltest ; then

        :

       else

          echo "*** Could not run GSL test program, checking why..."

          CFLAGS="$CFLAGS $GSL_CFLAGS"

          LIBS="$LIBS $GSL_LIBS"

          AC_TRY_LINK([

#include <stdio.h>

],      [ return 0; ],

        [ echo "*** The test program compiled, but did not run. This usually means"

          echo "*** that the run-time linker is not finding GSL or finding the wrong"

          echo "*** version of GSL. If it is not finding GSL, you'll need to set your"

          echo "*** LD_LIBRARY_PATH environment variable, or edit /etc/ld.so.conf to point"

          echo "*** to the installed location  Also, make sure you have run ldconfig if that"

          echo "*** is required on your system"

	  echo "***"

          echo "*** If you have an old version installed, it is best to remove it, although"

          echo "*** you may also be able to get things to work by modifying LD_LIBRARY_PATH"],

        [ echo "*** The test program failed to compile or link. See the file config.log for the"

          echo "*** exact error that occured. This usually means GSL was incorrectly installed"

          echo "*** or that you have moved GSL since it was installed. In the latter case, you"

          echo "*** may want to edit the gsl-config script: $GSL_CONFIG" ])

          CFLAGS="$ac_save_CFLAGS"

          LIBS="$ac_save_LIBS"

       fi

     fi

#     GSL_CFLAGS=""

#     GSL_LIBS=""

     ifelse([$3], , :, [$3])

  fi

  AC_SUBST(GSL_CFLAGS)

  AC_SUBST(GSL_LIBS)

  rm -f conf.gsltest

])

AU_ALIAS([AM_PATH_GSL], [AX_PATH_GSL])