# Check for NTL
# Bradford Hovinen, 2001-06-13
# Modified by Pascal Giorgi, 2003-12-03
# Inspired by gnome-bonobo-check.m4 by Miguel de Icaza, 99-04-12
# Stolen from Chris Lahey       99-2-5
# stolen from Manish Singh again
# stolen back from Frank Belew
# stolen from Manish Singh
# Shamelessly stolen from Owen Taylor

dnl LB_CHECK_NTL ([MINIMUM-VERSION [, ACTION-IF-FOUND [, ACTION-IF-NOT-FOUND]]])
dnl
dnl Test for Victor Shoup's NTL (Number Theory Library) and define
dnl NTL_CFLAGS and NTL_LIBS

AC_DEFUN([LB_CHECK_NTL],
[
DEFAULT_CHECKING_PATH="/usr /usr/local /sw /opt/local"

AC_ARG_WITH(ntl,
[  --with-ntl=<path>|yes|no  Use NTL library. If argument is no, you do not have
                            the library installed on your machine (set as 
			    default). If argument is yes or <empty> that means 
			    the library is reachable with the standard search 
			    path (/usr or /usr/local). Otherwise you give the 
			    <path> to the directory which contain the library. 
	     ],
	     [if test "$withval" = yes ; then
			NTL_HOME_PATH="${DEFAULT_CHECKING_PATH}"
	      elif test "$withval" != no ; then
			NTL_HOME_PATH="$withval"
	     fi],
	     [NTL_HOME_PATH="${DEFAULT_CHECKING_PATH}"])

min_ntl_version=ifelse([$1], ,1.0,$1)


dnl Check for existence
BACKUP_CXXFLAGS=${CXXFLAGS}
BACKUP_LIBS=${LIBS}

AC_LANG_PUSH(C++)

if test -n "$NTL_HOME_PATH"; then
AC_MSG_CHECKING(for NTL >= $min_ntl_version)
fi

for NTL_HOME in ${NTL_HOME_PATH} 
 do	
if test -r "$NTL_HOME/include/NTL/ZZ.h"; then

	if test "x$NTL_HOME" != "x/usr"; then
		NTL_CFLAGS="-I${NTL_HOME}/include"
		NTL_LIBS="-L${NTL_HOME}/lib -lntl"
	else
		NTL_CFLAGS=
		NTL_LIBS="-lntl"		
	fi	
	CXXFLAGS="${BACKUP_CXXFLAGS} ${NTL_CFLAGS} ${GMP_CFLAGS}" 
	LIBS="${BACKUP_LIBS} ${NTL_LIBS} ${GMP_LIBS}"

	AC_TRY_LINK(
	[#include <NTL/ZZ.h>],
	[NTL::ZZ a;],
	[
	AC_TRY_RUN(
	[#include <NTL/version.h>
	int main () { if (NTL_MAJOR_VERSION < 5) return -1; else return 0; }	
	],[
	ntl_found="yes"	
	break
	],[	
	ntl_problem="$problem $NTL_HOME"	
	unset NTL_CFLAGS
	unset NTL_LIBS	
	],[
	ntl_found="yes"
	ntl_cross="yes"	
	break
	])	
	],
	[
	ntl_found="no"
	ntl_checked="$checked $NTL_HOME"
	unset NTL_CFLAGS
	unset NTL_LIBS	
	])
else
	ntl_found="no"
fi
done

if test "x$ntl_found" = "xyes" ; then		
	AC_SUBST(NTL_CFLAGS)
	AC_SUBST(NTL_LIBS)
	AC_DEFINE(HAVE_NTL,1,[Define if NTL is installed])
	HAVE_NTL=yes
	if test "x$ntl_cross" != "xyes"; then
		AC_MSG_RESULT(found)
	else
		AC_MSG_RESULT(unknown)
		echo "WARNING: You appear to be cross compiling, so there is no way to determine"
		echo "whether your NTL version is new enough. I am assuming it is."
	fi
	ifelse([$2], , :, [$2])
elif test -n "$ntl_problem"; then
	AC_MSG_RESULT(problem)
	echo "Sorry, your NTL version is too old. Disabling."
	ifelse([$3], , :, [$3])
elif test   "x$ntl_found" = "xno";  then
	AC_MSG_RESULT(not found)
	ifelse([$3], , :, [$3])	
fi	

AC_LANG_POP

AM_CONDITIONAL(SING_HAVE_NTL, test "x$HAVE_NTL" = "xyes")

# TODO: The following seems to set CXXFLAGS even if it was not defined previously!!!!
CXXFLAGS=${BACKUP_CXXFLAGS}
LIBS=${BACKUP_LIBS}
#unset LD_LIBRARY_PATH

])