dnl @synopsis AC_COMPILE_WARNINGS
dnl
dnl Set the maximum warning verbosity according to C and C++ compiler used.
dnl Currently supports g++ and gcc.
dnl
dnl The compiler options are always added CFLAGS and CXXFLAGS even if
dnl these are overridden at configure time. Removing the maximum warning
dnl flags can be removed with --without-maximum-compile-warnings. For example:
dnl
dnl   ./configure --without-maximum-compile-warnings CFLAGS= CXXFLAGS=
dnl
dnl @category Misc
dnl @author Loic Dachary <loic@senga.org>
dnl @author William Fulton <wsf@fultondesigns.co.uk>
dnl @version 2005-04-29
dnl @license GPLWithACException

AC_DEFUN([AC_COMPILE_WARNINGS], [
AC_MSG_CHECKING([maximum warning verbosity option])
  AC_REQUIRE([AC_PROG_CC])
  AC_REQUIRE([AC_PROG_CXX])

  AC_ARG_WITH([maximum-compile-warnings], 
              AS_HELP_STRING([--without-maximum-compile-warnings],
                             [Disable maximum warning verbosity]),
              [ac_compile_warnings_on="$withval"],
              [ac_compile_warnings_on=""])

  if test x"$ac_compile_warnings_on" = xno
  then
    ac_compile_warnings_msg=no
  else
    if test -n "$CXX"
    then
      if test "$GXX" = "yes"
      then
        ac_compile_warnings_opt='-Wall -W -ansi -pedantic'
      fi
      CXXFLAGS="$CXXFLAGS $ac_compile_warnings_opt"
      ac_compile_warnings_msg="$ac_compile_warnings_opt for C++"
    fi

  if test -n "$CC"
  then
    if test "$GCC" = "yes"
    then
      ac_compile_warnings_opt='-Wall -W -ansi -pedantic'
    fi
    CFLAGS="$CFLAGS $ac_compile_warnings_opt"
    ac_compile_warnings_msg="$ac_compile_warnings_msg $ac_compile_warnings_opt for C"
  fi
  fi
  AC_MSG_RESULT([$ac_compile_warnings_msg])
  unset ac_compile_warnings_msg
  unset ac_compile_warnings_opt
])