acinclude.m4

      AC_DEFINE_UNQUOTED(SEND_TYPE_ARG3, $[3],
        [Define to the type of arg 3 for send.])
      AC_DEFINE_UNQUOTED(SEND_TYPE_ARG4, $[4],
        [Define to the type of arg 4 for send.])
      AC_DEFINE_UNQUOTED(SEND_TYPE_RETV, $[5],
        [Define to the function return type for send.])
      #
      prev_sh_opts=$-
      #
      case $prev_sh_opts in
        *f*)
          ;;
        *)
          set -f
          ;;
      esac
      #
      case "$send_qual_type_arg2" in
        const*)
          send_qual_arg2=const
          send_type_arg2=`echo $send_qual_type_arg2 | sed 's/^const //'`
        ;;
        *)
          send_qual_arg2=
          send_type_arg2=$send_qual_type_arg2
        ;;
      esac
      #
      AC_DEFINE_UNQUOTED(SEND_QUAL_ARG2, $send_qual_arg2,
        [Define to the type qualifier of arg 2 for send.])
      AC_DEFINE_UNQUOTED(SEND_TYPE_ARG2, $send_type_arg2,
        [Define to the type of arg 2 for send.])
      #
      case $prev_sh_opts in
        *f*)
          ;;
        *)
          set +f
          ;;
      esac
      #
      AC_DEFINE_UNQUOTED(HAVE_SEND, 1,
        [Define to 1 if you have the send function.])
      ac_cv_func_send="yes"
    fi
  else
    AC_MSG_ERROR([Unable to link function send])
  fi
]) # AC_DEFUN


dnl CURL_CHECK_MSG_NOSIGNAL
dnl -------------------------------------------------
dnl Check for MSG_NOSIGNAL

AC_DEFUN([CURL_CHECK_MSG_NOSIGNAL], [
  AC_CHECK_HEADERS(sys/types.h sys/socket.h)
  AC_CACHE_CHECK([for MSG_NOSIGNAL], [ac_cv_msg_nosignal], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
#undef inline 
#ifdef HAVE_WINDOWS_H
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#else
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#endif
#else
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#endif
      ]],[[
        int flag=MSG_NOSIGNAL;
      ]])
    ],[
      ac_cv_msg_nosignal="yes"
    ],[
      ac_cv_msg_nosignal="no"
    ])
  ])
  case "$ac_cv_msg_nosignal" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_MSG_NOSIGNAL, 1,
        [Define to 1 if you have the MSG_NOSIGNAL flag.])
      ;;
  esac
]) # AC_DEFUN


dnl CURL_CHECK_STRUCT_TIMEVAL
dnl -------------------------------------------------
dnl Check for timeval struct

AC_DEFUN([CURL_CHECK_STRUCT_TIMEVAL], [
  AC_REQUIRE([AC_HEADER_TIME])dnl
  AC_REQUIRE([CURL_CHECK_HEADER_WINSOCK])dnl
  AC_REQUIRE([CURL_CHECK_HEADER_WINSOCK2])dnl
  AC_CHECK_HEADERS(sys/types.h sys/time.h time.h)
  AC_CACHE_CHECK([for struct timeval], [ac_cv_struct_timeval], [
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
#undef inline 
#ifdef HAVE_WINDOWS_H
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#else
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#endif
#endif
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#ifdef TIME_WITH_SYS_TIME
#include <time.h>
#endif
#else
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#endif
      ]],[[
        struct timeval ts;
        ts.tv_sec  = 0;
        ts.tv_usec = 0;
      ]])
    ],[
      ac_cv_struct_timeval="yes"
    ],[
      ac_cv_struct_timeval="no"
    ])
  ])
  case "$ac_cv_struct_timeval" in
    yes)
      AC_DEFINE_UNQUOTED(HAVE_STRUCT_TIMEVAL, 1,
        [Define to 1 if you have the timeval struct.])
      ;;
  esac
]) # AC_DEFUN


dnl TYPE_SIG_ATOMIC_T
dnl -------------------------------------------------
dnl Check if the sig_atomic_t type is available, and
dnl verify if it is already defined as volatile.

AC_DEFUN([TYPE_SIG_ATOMIC_T], [
  AC_CHECK_HEADERS(signal.h)
  AC_CHECK_TYPE([sig_atomic_t],[
    AC_DEFINE(HAVE_SIG_ATOMIC_T, 1,
      [Define to 1 if sig_atomic_t is an available typedef.])
  ], ,[
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
  ])
  case "$ac_cv_type_sig_atomic_t" in
    yes)
      #
      AC_MSG_CHECKING([if sig_atomic_t is already defined as volatile])
      AC_LINK_IFELSE([
        AC_LANG_PROGRAM([[
#ifdef HAVE_SIGNAL_H
#include <signal.h>
#endif
        ]],[[
          static volatile sig_atomic_t dummy = 0;
        ]])
      ],[
        AC_MSG_RESULT([no])
        ac_cv_sig_atomic_t_volatile="no"
      ],[
        AC_MSG_RESULT([yes])
        ac_cv_sig_atomic_t_volatile="yes"
      ])
      #
      if test "$ac_cv_sig_atomic_t_volatile" = "yes"; then
        AC_DEFINE(HAVE_SIG_ATOMIC_T_VOLATILE, 1,
          [Define to 1 if sig_atomic_t is already defined as volatile.])
      fi
      ;;
  esac
]) # AC_DEFUN


dnl CURL_CHECK_NONBLOCKING_SOCKET
dnl -------------------------------------------------
dnl Check for how to set a socket to non-blocking state. There seems to exist
dnl four known different ways, with the one used almost everywhere being POSIX
dnl and XPG3, while the other different ways for different systems (old BSD,
dnl Windows and Amiga).
dnl
dnl There are two known platforms (AIX 3.x and SunOS 4.1.x) where the
dnl O_NONBLOCK define is found but does not work. This condition is attempted
dnl to get caught in this script by using an excessive number of #ifdefs...

AC_DEFUN([CURL_CHECK_NONBLOCKING_SOCKET], [
  AC_MSG_CHECKING([non-blocking sockets style])
  nonblock="unknown"
  #
  AC_COMPILE_IFELSE([
    AC_LANG_PROGRAM([[
/* headers for O_NONBLOCK test */
#include <sys/types.h>
#include <unistd.h>
#include <fcntl.h>
/* */
#if defined(sun) || defined(__sun__) || \
    defined(__SUNPRO_C) || defined(__SUNPRO_CC)
# if defined(__SVR4) || defined(__srv4__)
#  define PLATFORM_SOLARIS
# else
#  define PLATFORM_SUNOS4
# endif
#endif
#if (defined(_AIX) || defined(__xlC__)) && !defined(_AIX41)
# define PLATFORM_AIX_V3
#endif
/* */
#if defined(PLATFORM_SUNOS4) || defined(PLATFORM_AIX_V3) || defined(__BEOS__)
#error "O_NONBLOCK does not work on this platform"
#endif
    ]],[[
      /* O_NONBLOCK source test */
      int socket;
      int flags = fcntl(socket, F_SETFL, flags | O_NONBLOCK);
    ]])
  ],[
    dnl the O_NONBLOCK test was fine
    nonblock="O_NONBLOCK"
    AC_DEFINE(HAVE_O_NONBLOCK, 1,
      [use O_NONBLOCK for non-blocking sockets])
  ])
  #
  if test "$nonblock" = "unknown"; then
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
/* headers for FIONBIO test */
#include <unistd.h>
#include <stropts.h>
      ]],[[
        /* FIONBIO source test (old-style unix) */
        int socket;
        int flags = ioctl(socket, FIONBIO, &flags);
      ]])
    ],[
      dnl FIONBIO test was good
      nonblock="FIONBIO"
      AC_DEFINE(HAVE_FIONBIO, 1,
        [use FIONBIO for non-blocking sockets])
    ])
  fi
  #
  if test "$nonblock" = "unknown"; then
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
/* headers for ioctlsocket test (Windows) */
#undef inline
#ifdef HAVE_WINDOWS_H
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#else
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#endif
#endif
      ]],[[
        /* ioctlsocket source code (Windows) */
        SOCKET sd;
        unsigned long flags = 0;
        sd = socket(0, 0, 0);
        ioctlsocket(sd, FIONBIO, &flags);
      ]])
    ],[
      dnl ioctlsocket test was good
      nonblock="ioctlsocket"
      AC_DEFINE(HAVE_IOCTLSOCKET, 1,
        [use ioctlsocket() for non-blocking sockets])
    ])
  fi
  #
  if test "$nonblock" = "unknown"; then
    AC_LINK_IFELSE([
      AC_LANG_PROGRAM([[
/* headers for IoctlSocket test (Amiga?) */
#include <sys/ioctl.h>
      ]],[[
        /* IoctlSocket source code (Amiga?) */
        int socket;
        int flags = IoctlSocket(socket, FIONBIO, (long)1);
      ]])
    ],[
      dnl Ioctlsocket test was good
      nonblock="IoctlSocket"
      AC_DEFINE(HAVE_IOCTLSOCKET_CASE, 1,
        [use Ioctlsocket() for non-blocking sockets])
    ])
  fi
  #
  if test "$nonblock" = "unknown"; then
    AC_COMPILE_IFELSE([
      AC_LANG_PROGRAM([[
/* headers for SO_NONBLOCK test (BeOS) */
#include <socket.h>
      ]],[[
        /* SO_NONBLOCK source code (BeOS) */
        long b = 1;
        int socket;
        int flags = setsockopt(socket, SOL_SOCKET, SO_NONBLOCK, &b, sizeof(b));
      ]])
    ],[
      dnl the SO_NONBLOCK test was good
      nonblock="SO_NONBLOCK"
      AC_DEFINE(HAVE_SO_NONBLOCK, 1,
        [use SO_NONBLOCK for non-blocking sockets])
    ])
  fi
  #
  AC_MSG_RESULT($nonblock)
  #
  if test "$nonblock" = "unknown"; then
    AC_DEFINE(HAVE_DISABLED_NONBLOCKING, 1,
      [disabled non-blocking sockets])
    AC_MSG_WARN([non-block sockets disabled])
  fi
])


dnl TYPE_IN_ADDR_T
dnl -------------------------------------------------
dnl Check for in_addr_t: it is used to receive the return code of inet_addr()
dnl and a few other things.

AC_DEFUN([TYPE_IN_ADDR_T], [
  AC_CHECK_TYPE([in_addr_t], ,[
    dnl in_addr_t not available
    AC_CACHE_CHECK([for in_addr_t equivalent],
      [curl_cv_in_addr_t_equiv], [
      curl_cv_in_addr_t_equiv="unknown"
      for t in "unsigned long" int size_t unsigned long; do
        if test "$curl_cv_in_addr_t_equiv" = "unknown"; then
          AC_LINK_IFELSE([
            AC_LANG_PROGRAM([[
#undef inline
#ifdef HAVE_WINDOWS_H
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#else
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#endif
#else
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#endif
            ]],[[
              $t data = inet_addr ("1.2.3.4");
            ]])
          ],[
            curl_cv_in_addr_t_equiv="$t"
          ])
        fi
      done
    ])
    case "$curl_cv_in_addr_t_equiv" in
      unknown)
        AC_MSG_ERROR([Cannot find a type to use in place of in_addr_t])
        ;;
      *)
        AC_DEFINE_UNQUOTED(in_addr_t, $curl_cv_in_addr_t_equiv,
          [Type to use in place of in_addr_t when system does not provide it.])
        ;;
    esac
  ],[
#undef inline
#ifdef HAVE_WINDOWS_H
#ifndef WIN32_LEAN_AND_MEAN
#define WIN32_LEAN_AND_MEAN
#endif
#include <windows.h>
#ifdef HAVE_WINSOCK2_H
#include <winsock2.h>
#else
#ifdef HAVE_WINSOCK_H
#include <winsock.h>
#endif
#endif
#else
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
#ifdef HAVE_NETINET_IN_H
#include <netinet/in.h>
#endif
#ifdef HAVE_ARPA_INET_H
#include <arpa/inet.h>
#endif
#endif
  ]) dnl AC_CHECK_TYPE
]) dnl AC_DEFUN


dnl CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC
dnl -------------------------------------------------
dnl Check if monotonic clock_gettime is available.

AC_DEFUN([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC], [
  AC_REQUIRE([AC_HEADER_TIME])dnl
  AC_CHECK_HEADERS(sys/types.h unistd.h sys/time.h time.h)
  AC_MSG_CHECKING([for monotonic clock_gettime])
  AC_COMPILE_IFELSE([
    AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#ifdef TIME_WITH_SYS_TIME
#include <time.h>
#endif
#else
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#endif
    ]],[[
#if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK > 0)
      /*
      The monotonic clock will not be used unless the feature test macro is
      defined with a value greater than zero indicating _always_ supported.
      */
      struct timespec ts;
      (void)clock_gettime(CLOCK_MONOTONIC, &ts);
#else
      HAVE_CLOCK_GETTIME_MONOTONIC shall not be defined.
#endif
    ]])
  ],[
    AC_MSG_RESULT([yes])
    ac_cv_func_clock_gettime="yes"
  ],[
    AC_MSG_RESULT([no])
    ac_cv_func_clock_gettime="no"
  ])
  dnl Definition of HAVE_CLOCK_GETTIME_MONOTONIC is intentionally
  dnl postponed until library linking checks for clock_gettime pass.
]) dnl AC_DEFUN


dnl CURL_CHECK_LIBS_CLOCK_GETTIME_MONOTONIC
dnl -------------------------------------------------
dnl If monotonic clock_gettime is available then,
dnl check and prepended to LIBS any needed libraries.

AC_DEFUN([CURL_CHECK_LIBS_CLOCK_GETTIME_MONOTONIC], [
  AC_REQUIRE([CURL_CHECK_FUNC_CLOCK_GETTIME_MONOTONIC])dnl
  #
  if test "$ac_cv_func_clock_gettime" = "yes"; then
    #
    AC_MSG_CHECKING([for clock_gettime in libraries])
    #
    curl_cv_save_LIBS="$LIBS"
    curl_cv_gclk_LIBS="unknown"
    #
    for x_xlibs in '' '-lrt' '-lposix4' ; do
      if test "$curl_cv_gclk_LIBS" = "unknown"; then
        if test -z "$x_xlibs"; then
          LIBS="$curl_cv_save_LIBS"
        else
          LIBS="$x_xlibs $curl_cv_save_LIBS"
        fi
        AC_LINK_IFELSE([
          AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#ifdef TIME_WITH_SYS_TIME
#include <time.h>
#endif
#else
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#endif
          ]],[[
            struct timespec ts;
            (void)clock_gettime(CLOCK_MONOTONIC, &ts);
          ]])
        ],[
          curl_cv_gclk_LIBS="$x_xlibs"
        ])
      fi
    done
    #
    LIBS="$curl_cv_save_LIBS"
    #
    case X-"$curl_cv_gclk_LIBS" in
      X-unknown)
        AC_MSG_RESULT([cannot find clock_gettime])
        AC_MSG_WARN([HAVE_CLOCK_GETTIME_MONOTONIC will not be defined])
        ac_cv_func_clock_gettime="no"
        ;;
      X-)
        AC_MSG_RESULT([no additional lib required])
        ac_cv_func_clock_gettime="yes"
        ;;
      *)
        if test -z "$curl_cv_save_LIBS"; then
          LIBS="$curl_cv_gclk_LIBS"
        else
          LIBS="$curl_cv_gclk_LIBS $curl_cv_save_LIBS"
        fi
        AC_MSG_RESULT([$curl_cv_gclk_LIBS])
        ac_cv_func_clock_gettime="yes"
        ;;
    esac
    #
    dnl only do runtime verification when not cross-compiling
    if test "x$cross_compiling" != "xyes" &&
      test "$ac_cv_func_clock_gettime" = "yes"; then
      AC_MSG_CHECKING([if monotonic clock_gettime works])
      AC_RUN_IFELSE([
        AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#ifdef HAVE_SYS_TIME_H
#include <sys/time.h>
#ifdef TIME_WITH_SYS_TIME
#include <time.h>
#endif
#else
#ifdef HAVE_TIME_H
#include <time.h>
#endif
#endif
        ]],[[
#if defined(_POSIX_MONOTONIC_CLOCK) && (_POSIX_MONOTONIC_CLOCK > 0)
          struct timespec ts;
          if (0 == clock_gettime(CLOCK_MONOTONIC, &ts))
            exit(0);
#endif
          exit(1);
        ]])
      ],[
        AC_MSG_RESULT([yes])
      ],[
        AC_MSG_RESULT([no])
        AC_MSG_WARN([HAVE_CLOCK_GETTIME_MONOTONIC will not be defined])
        ac_cv_func_clock_gettime="no"
        LIBS="$curl_cv_save_LIBS"
      ])
    fi
    #
    case "$ac_cv_func_clock_gettime" in
      yes)
        AC_DEFINE_UNQUOTED(HAVE_CLOCK_GETTIME_MONOTONIC, 1,
          [Define to 1 if you have the clock_gettime function and monotonic timer.])
        ;;
    esac
    #
  fi
  #
]) dnl AC_DEFUN


dnl **********************************************************************
dnl CURL_DETECT_ICC ([ACTION-IF-YES])
dnl
dnl check if this is the Intel ICC compiler, and if so run the ACTION-IF-YES
dnl sets the $ICC variable to "yes" or "no"
dnl **********************************************************************
AC_DEFUN([CURL_DETECT_ICC],
[
    ICC="no"
    AC_MSG_CHECKING([for icc in use])
    if test "$GCC" = "yes"; then
       dnl check if this is icc acting as gcc in disguise
       AC_EGREP_CPP([^__INTEL_COMPILER], [__INTEL_COMPILER],
         dnl action if the text is found, this it has not been replaced by the
         dnl cpp
         ICC="no",
         dnl the text was not found, it was replaced by the cpp
         ICC="yes"
         AC_MSG_RESULT([yes])
         [$1]
       )
    fi
    if test "$ICC" = "no"; then
        # this is not ICC
        AC_MSG_RESULT([no])
    fi
])

dnl We create a function for detecting which compiler we use and then set as
dnl pendantic compiler options as possible for that particular compiler. The
dnl options are only used for debug-builds.

dnl This is a copy of the original found in curl's configure script. Don't
dnl modify this one, edit the one in curl and copy it back here when that one
dnl is changed.

AC_DEFUN([CURL_CC_DEBUG_OPTS],
[
    if test "z$ICC" = "z"; then
      CURL_DETECT_ICC
    fi

    if test "$GCC" = "yes"; then

       dnl figure out gcc version!
       AC_MSG_CHECKING([gcc version])
       gccver=`$CC -dumpversion`
       num1=`echo $gccver | cut -d . -f1`
       num2=`echo $gccver | cut -d . -f2`
       gccnum=`(expr $num1 "*" 100 + $num2) 2>/dev/null`
       AC_MSG_RESULT($gccver)

       if test "$ICC" = "yes"; then
         dnl this is icc, not gcc.

         dnl ICC warnings we ignore:
         dnl * 269 warns on our "%Od" printf formatters for curl_off_t output:
         dnl   "invalid format string conversion"
         dnl * 279 warns on static conditions in while expressions
         dnl * 981 warns on "operands are evaluated in unspecified order"
         dnl * 1418 "external definition with no prior declaration"
         dnl * 1419 warns on "external declaration in primary source file"
         dnl   which we know and do on purpose.

         WARN="-wd279,269,981,1418,1419"

         if test "$gccnum" -gt "600"; then
            dnl icc 6.0 and older doesn't have the -Wall flag
            WARN="-Wall $WARN"
         fi
       else dnl $ICC = yes
         dnl this is a set of options we believe *ALL* gcc versions support:
         WARN="-W -Wall -Wwrite-strings -pedantic -Wpointer-arith -Wnested-externs -Winline -Wmissing-prototypes"

         dnl -Wcast-align is a bit too annoying on all gcc versions ;-)

         if test "$gccnum" -ge "207"; then
           dnl gcc 2.7 or later
           WARN="$WARN -Wmissing-declarations"
         fi

         if test "$gccnum" -gt "295"; then
           dnl only if the compiler is newer than 2.95 since we got lots of
           dnl "`_POSIX_C_SOURCE' is not defined" in system headers with
           dnl gcc 2.95.4 on FreeBSD 4.9!
           WARN="$WARN -Wundef -Wno-long-long -Wsign-compare -Wshadow -Wno-multichar"
         fi

         if test "$gccnum" -ge "296"; then
           dnl gcc 2.96 or later
           WARN="$WARN -Wfloat-equal"
         fi

         if test "$gccnum" -gt "296"; then
           dnl this option does not exist in 2.96
           WARN="$WARN -Wno-format-nonliteral"
         fi

         dnl -Wunreachable-code seems totally unreliable on my gcc 3.3.2 on
         dnl on i686-Linux as it gives us heaps with false positives.
         dnl Also, on gcc 4.0.X it is totally unbearable and complains all
         dnl over making it unusable for generic purposes. Let's not use it.

         if test "$gccnum" -ge "303"; then
           dnl gcc 3.3 and later
           WARN="$WARN -Wendif-labels -Wstrict-prototypes"
         fi

         if test "$gccnum" -ge "304"; then
           # try these on gcc 3.4
           WARN="$WARN -Wdeclaration-after-statement"
         fi

         for flag in $CPPFLAGS; do
           case "$flag" in
            -I*)
              dnl Include path, provide a -isystem option for the same dir
              dnl to prevent warnings in those dirs. The -isystem was not very
              dnl reliable on earlier gcc versions.
              add=`echo $flag | sed 's/^-I/-isystem /g'`
              WARN="$WARN $add"
              ;;
           esac
         done

       fi dnl $ICC = no

       CFLAGS="$CFLAGS $WARN"

      AC_MSG_NOTICE([Added this set of compiler options: $WARN])

    else dnl $GCC = yes

      AC_MSG_NOTICE([Added no extra compiler options])

    fi dnl $GCC = yes

    dnl strip off optimizer flags
    NEWFLAGS=""
    for flag in $CFLAGS; do
      case "$flag" in
      -O*)
        dnl echo "cut off $flag"
        ;;
      *)
        NEWFLAGS="$NEWFLAGS $flag"
        ;;
      esac
    done
    CFLAGS=$NEWFLAGS

]) dnl end of AC_DEFUN()


dnl This macro determines if the specified struct exists in the specified file
dnl Syntax:
dnl CARES_CHECK_STRUCT(headers, struct name, if found, [if not found])

AC_DEFUN([CARES_CHECK_STRUCT], [
  AC_MSG_CHECKING([for struct $2])
  AC_TRY_COMPILE([$1], 
    [
      struct $2 struct_instance;
    ], ac_struct="yes", ac_found="no")
  if test "$ac_struct" = "yes" ; then
    AC_MSG_RESULT(yes)
    $3
  else
    AC_MSG_RESULT(no)
    $4
  fi
])

dnl This macro determines if the specified constant exists in the specified file
dnl Syntax:
dnl CARES_CHECK_CONSTANT(headers, constant name, if found, [if not found])

AC_DEFUN([CARES_CHECK_CONSTANT], [
  AC_MSG_CHECKING([for $2])
  AC_EGREP_CPP(VARIABLEWASDEFINED,
   [
      $1

      #ifdef $2
        VARIABLEWASDEFINED
      #else
        NJET
      #endif
    ], ac_constant="yes", ac_constant="no"
  )
  if test "$ac_constant" = "yes" ; then
    AC_MSG_RESULT(yes)
    $3
  else
    AC_MSG_RESULT(no)
    $4
  fi
])


dnl CARES_CHECK_GETSERVBYPORT_R
dnl -------------------------------------------------
dnl Test if the getservbyport_r function is available,
dnl and find out how many parameters it takes.

AC_DEFUN([CARES_CHECK_GETSERVBYPORT_R], [
  AC_MSG_CHECKING([how many arguments getservbyport_r takes])
  ac_func_getservbyport_r="unknown"

  AC_LINK_IFELSE([
    AC_LANG_PROGRAM([[
#include <netdb.h>
    ]],[[
      int p1, p5;
      char *p2, p4[4096];
      struct servent *p3, *p6;
      getservbyport_r(p1, p2, p3, p4, p5, &p6);
    ]])
  ],[
    ac_func_getservbyport_r="6"
  ])

  if test "$ac_func_getservbyport_r" = "unknown"; then
    AC_LINK_IFELSE([
      AC_LANG_PROGRAM([[
#include <netdb.h>
      ]],[[
        int p1, p5;
        char *p2, p4[4096];
        struct servent *p3;
        getservbyport_r(p1, p2, p3, p4, p5);
      ]])
    ],[
      ac_func_getservbyport_r="5"
    ])
  fi

  if test "$ac_func_getservbyport_r" = "unknown"; then
    AC_LINK_IFELSE([
      AC_LANG_PROGRAM([[
#include <netdb.h>
      ]],[[
        int p1;
        char *p2;
        struct servent *p3;
        struct servent_data p4;
        getservbyport_r(p1, p2, p3, &p4);
      ]])
    ],[
      ac_func_getservbyport_r="4"
    ])
  fi

  if test "$ac_func_getservbyport_r" = "unknown"; then
    AC_MSG_RESULT([not found])
  else
    AC_MSG_RESULT($ac_func_getservbyport_r)
    AC_DEFINE(HAVE_GETSERVBYPORT_R, 1,
      [Specifies whether getservbyport_r is present])
    AC_DEFINE_UNQUOTED(GETSERVBYPORT_R_ARGS, $ac_func_getservbyport_r,
      [Specifies the number of arguments to getservbyport_r])
    if test "$ac_func_getservbyport_r" = "4" ; then
      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, sizeof(struct servent_data),
        [Specifies the size of the buffer to pass to getservbyport_r])
    else
      AC_DEFINE(GETSERVBYPORT_R_BUFSIZE, 4096,
        [Specifies the size of the buffer to pass to getservbyport_r])
    fi
  fi
])