dnl  Copyright (C) 2003  OPEN CASCADE, EADS/CCR, LIP6, CEA/DEN,
dnl  CEDRAT, EDF R&D, LEG, PRINCIPIA R&D, BUREAU VERITAS 
dnl 
dnl  This library is free software; you can redistribute it and/or 
dnl  modify it under the terms of the GNU Lesser General Public 
dnl  License as published by the Free Software Foundation; either 
dnl  version 2.1 of the License. 
dnl 
dnl  This library is distributed in the hope that it will be useful, 
dnl  but WITHOUT ANY WARRANTY; without even the implied warranty of 
dnl  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU 
dnl  Lesser General Public License for more details. 
dnl 
dnl  You should have received a copy of the GNU Lesser General Public 
dnl  License along with this library; if not, write to the Free Software 
dnl  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307 USA 
dnl 
dnl  See http://www.opencascade.org/SALOME/ or email : webmaster.salome@opencascade.org 
dnl
dnl
dnl
dnl @synopsis AC_C_DEPEND_FLAG
dnl
dnl define C_DEPEND_FLAG
dnl define CXX_DEPEND_FLAG
dnl
dnl @version $Id$
dnl @author Marc Tajchman
dnl
AC_DEFUN(AC_DEPEND_FLAG,
[AC_CACHE_CHECK(which flag for dependency information generation,
ac_cv_depend_flag,
[AC_LANG_SAVE
 AC_LANG_C
 echo "conftest.o: conftest.c" > conftest.verif
 echo "int  main() { return 0; }" > conftest.c

dnl Evolution portage sur CCRT/osf system
 case $host_os in
   osf*)
dnl sur CCRT/osf pas d'equivalent de l'option -MG de gcc avec compilo natif
dnl on utilise donc gnu pour generer les dependances.
     DEPCC=gcc
     DEPCXX=g++
     DEPCXXFLAGS="-Wno-deprecated"
     DIFFFLAGS="-w"
     MACHINE="OSF1"
     ;;
   *)
     DEPCC=${CC-cc}
     DEPCXX=${CXX-c++}
     DEPCXXFLAGS="\${CXXFLAGS}"
     DIFFFLAGS="-b -B"
     MACHINE="PCLINUX"
     ;;
 esac
 C_DEPEND_FLAG=
 for ac_C_DEPEND_FLAG in -xM -MM -M ; do

    rm -f conftest.d conftest.err
    ${DEPCC} ${ac_C_DEPEND_FLAG} -c conftest.c 1> conftest.d 2> conftest.err
    if test -f conftest.u ; then
       mv conftest.u conftest.d
    fi

    rm -f conftest
    diff ${DIFFFLAGS} conftest.d conftest.verif > conftest
    if test ! -s conftest ; then
       C_DEPEND_FLAG=${ac_C_DEPEND_FLAG}
       break
    fi
 done

dnl use gcc option -MG : asume unknown file will be construct later
 rm -f conftest.d conftest.err
 ${DEPCC} ${C_DEPEND_FLAG} -MG -c conftest.c 1> conftest.d 2> conftest.err
 if test -f conftest.u ; then
    mv conftest.u conftest.d
 fi
 rm -f conftest
 diff ${DIFFFLAGS} conftest.d conftest.verif > conftest
 if test ! -s conftest ; then
    C_DEPEND_FLAG=${C_DEPEND_FLAG}" -MG"
 fi

 rm -f conftest*
 if test "x${C_DEPEND_FLAG}" = "x" ; then
    echo "cannot determine flag (C language)"
    exit
 fi

 printf " C :  ${DEPCC} ${C_DEPEND_FLAG}"

 AC_LANG_CPLUSPLUS
 echo "conftest.o: conftest.cxx" > conftest.verif
 echo "int  main() { return 0; }" > conftest.cxx

 CXX_DEPEND_FLAG=
 for ac_CXX_DEPEND_FLAG in -xM -MM -M ; do

    rm -f conftest.d conftest.err
    ${DEPCXX} ${ac_CXX_DEPEND_FLAG} -c conftest.cxx 1> conftest.d 2> conftest.err
    if test -f conftest.u ; then
       mv conftest.u conftest.d
    fi

    rm -f conftest
    diff ${DIFFFLAGS} conftest.d conftest.verif > conftest
    if test ! -s conftest ; then
       CXX_DEPEND_FLAG=${ac_CXX_DEPEND_FLAG}
       break
    fi
 done

dnl use g++ option -MG : asume unknown file will be construct later
 rm -f conftest.d conftest.err
 ${DEPCXX} ${CXX_DEPEND_FLAG} -MG -c conftest.cxx 1> conftest.d 2> conftest.err
 if test -f conftest.u ; then
    mv conftest.u conftest.d
 fi
 rm -f conftest
 diff ${DIFFFLAGS} conftest.d conftest.verif > conftest
 if test ! -s conftest ; then
    CXX_DEPEND_FLAG=${CXX_DEPEND_FLAG}" -MG"
 fi


 rm -f conftest*
 if test "x${CXX_DEPEND_FLAG}" = "x" ; then
    echo "cannot determine flag (C++ language)"
    exit
 fi

 printf " C++ : ${DEPCXX} ${CXX_DEPEND_FLAG}"
 AC_LANG_RESTORE

 AC_SUBST(DEPCC)
 AC_SUBST(DEPCXX)
 AC_SUBST(DEPCXXFLAGS)
 AC_SUBST(C_DEPEND_FLAG)
 AC_SUBST(CXX_DEPEND_FLAG)
 AC_SUBST(MACHINE)
])
])