dnl Autoconf macros for libgcrypt
dnl       Copyright (C) 2002, 2004 Free Software Foundation, Inc.
dnl
dnl This file is free software; as a special exception the author gives
dnl unlimited permission to copy and/or distribute it, with or without
dnl modifications, as long as this notice is preserved.
dnl
dnl This file is distributed in the hope that it will be useful, but
dnl WITHOUT ANY WARRANTY, to the extent permitted by law; without even the
dnl implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.


dnl AM_PATH_LIBGCRYPT([MINIMUM-VERSION,
dnl                   [ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND ]]])
dnl Test for libgcrypt and define LIBGCRYPT_CFLAGS and LIBGCRYPT_LIBS.
dnl MINIMUN-VERSION is a string with the version number optionalliy prefixed
dnl with the API version to also check the API compatibility. Example:
dnl a MINIMUN-VERSION of 1:1.2.5 won't pass the test unless the installed 
dnl version of libgcrypt is at least 1.2.5 *and* the API number is 1.  Using
dnl this features allows to prevent build against newer versions of libgcrypt
dnl with a changed API.
dnl
AC_DEFUN([AM_PATH_LIBGCRYPT],
[ AC_ARG_WITH(libgcrypt-prefix,
            AC_HELP_STRING([--with-libgcrypt-prefix=PFX],
                           [prefix where LIBGCRYPT is installed (optional)]),
     libgcrypt_config_prefix="$withval", libgcrypt_config_prefix="")
  if test x$libgcrypt_config_prefix != x ; then
     if test x${LIBGCRYPT_CONFIG+set} != xset ; then
        LIBGCRYPT_CONFIG=$libgcrypt_config_prefix/bin/libgcrypt-config
     fi
  fi

  AC_PATH_PROG(LIBGCRYPT_CONFIG, libgcrypt-config, no)
  tmp=ifelse([$1], ,1:1.2.0,$1)
  if echo "$tmp" | grep ':' >/dev/null 2>/dev/null ; then
     req_libgcrypt_api=`echo "$tmp"     | sed 's/\(.*\):\(.*\)/\1/'`
     min_libgcrypt_version=`echo "$tmp" | sed 's/\(.*\):\(.*\)/\2/'`
  else
     req_libgcrypt_api=0
     min_libgcrypt_version="$tmp"
  fi

  AC_MSG_CHECKING(for LIBGCRYPT - version >= $min_libgcrypt_version)
  ok=no
  if test "$LIBGCRYPT_CONFIG" != "no" ; then
    req_major=`echo $min_libgcrypt_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\1/'`
    req_minor=`echo $min_libgcrypt_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\2/'`
    req_micro=`echo $min_libgcrypt_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\)/\3/'`
    libgcrypt_config_version=`$LIBGCRYPT_CONFIG --version`
    major=`echo $libgcrypt_config_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\1/'`
    minor=`echo $libgcrypt_config_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\2/'`
    micro=`echo $libgcrypt_config_version | \
               sed 's/\([[0-9]]*\)\.\([[0-9]]*\)\.\([[0-9]]*\).*/\3/'`
    if test "$major" -gt "$req_major"; then
        ok=yes
    else 
        if test "$major" -eq "$req_major"; then
            if test "$minor" -gt "$req_minor"; then
               ok=yes
            else
               if test "$minor" -eq "$req_minor"; then
                   if test "$micro" -ge "$req_micro"; then
                     ok=yes
                   fi
               fi
            fi
        fi
    fi
  fi
  if test $ok = yes; then
    AC_MSG_RESULT([yes ($libgcrypt_config_version)])
  else
    AC_MSG_RESULT(no)
  fi
  if test $ok = yes; then
     # If we have a recent libgcrypt, we should also check that the
     # API is compatible
     if test "$req_libgcrypt_api" -gt 0 ; then
        tmp=`$LIBGCRYPT_CONFIG --api-version 2>/dev/null || echo 0`
        if test "$tmp" -gt 0 ; then
           AC_MSG_CHECKING([LIBGCRYPT API version])
           if test "$req_libgcrypt_api" -eq "$tmp" ; then
             AC_MSG_RESULT([okay])
           else
             ok=no
             AC_MSG_RESULT([does not match. want=$req_libgcrypt_api got=$tmp])
           fi
        fi
     fi
  fi
  if test $ok = yes; then
    LIBGCRYPT_CFLAGS=`$LIBGCRYPT_CONFIG --cflags`
    LIBGCRYPT_LIBS=`$LIBGCRYPT_CONFIG --libs`
    ifelse([$2], , :, [$2])
  else
    LIBGCRYPT_CFLAGS=""
    LIBGCRYPT_LIBS=""
    ifelse([$3], , :, [$3])
  fi
  AC_SUBST(LIBGCRYPT_CFLAGS)
  AC_SUBST(LIBGCRYPT_LIBS)
])