[thirdparty/gcc.git] / libstdc++-v3 / aclocal.m4

# generated automatically by aclocal 1.7.8 -*- Autoconf -*-

# Copyright (C) 1996, 1997, 1998, 1999, 2000, 2001, 2002
# Free Software Foundation, Inc.
# This file is free software; the Free Software Foundation
# gives unlimited permission to copy and/or distribute it,
# with or without modifications, as long as this notice is preserved.

# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY, to the extent permitted by law; without
# even the implied warranty of MERCHANTABILITY or FITNESS FOR A
# PARTICULAR PURPOSE.


dnl
dnl GLIBCXX_CONDITIONAL (NAME, SHELL-TEST)
dnl
dnl Exactly like AM_CONDITIONAL, but delays evaluation of the test until the
dnl end of configure.  This lets tested variables be reassigned, and the
dnl conditional will depend on the final state of the variable.  For a simple
dnl example of why this is needed, see GLIBCXX_ENABLE_HOSTED.
dnl
m4_define([_m4_divert(glibcxx_diversion)], 8000)dnl
AC_DEFUN([GLIBCXX_CONDITIONAL], [dnl
  m4_divert_text([glibcxx_diversion],dnl
   AM_CONDITIONAL([$1],[$2])
  )dnl
])dnl
AC_DEFUN([GLIBCXX_EVALUATE_CONDITIONALS], [m4_undivert([glibcxx_diversion])])dnl


dnl
dnl Check to see what architecture and operating system we are compiling
dnl for.  Also, if architecture- or OS-specific flags are required for
dnl compilation, pick them up here.
dnl
AC_DEFUN([GLIBCXX_CHECK_HOST], [
  . $glibcxx_srcdir/configure.host
  AC_MSG_NOTICE([CPU config directory is $cpu_include_dir])
  AC_MSG_NOTICE([OS config directory is $os_include_dir])
])


dnl
dnl Initialize basic configure bits.
dnl
dnl Substs:
dnl  multi_basedir
dnl
AC_DEFUN([GLIBCXX_TOPREL_CONFIGURE], [
  # Sets up multi_basedir, which is srcdir/.. plus the usual
  # "multi_source_toprel_bottom_adjust" lunacy as needed.
  AM_ENABLE_MULTILIB(, ..)

  # The generated code is exactly the same, except that automake's looks in
  # ".. $srcdir/.." and autoconf's looks in multi_basedir.  Apparently other
  # things are triggered on the presence of the two ...AUX_DIR[S], but I don't
  # know what they are or what the other differences might be (and they keep
  # changing anyhow).
  #
  # Looking in multi_basedir seems smarter, so actually execute that branch.
  if false; then
    # this is for automake
    AC_CONFIG_AUX_DIR(..)
  else
    # this is for autoconf
    AC_CONFIG_AUX_DIRS(${multi_basedir})
  fi

  dnl XXX Turn this on.
  dnl AC_LANG_CPLUSPLUS
])


dnl
dnl Initialize the rest of the library configury.  At this point we have
dnl variables like $host.
dnl
dnl Sets:
dnl  gcc_version          (x.y.z format)
dnl  SUBDIRS
dnl Substs:
dnl  glibcxx_builddir     (absolute path)
dnl  glibcxx_srcdir       (absolute path)
dnl  toplevel_srcdir      (absolute path)
dnl  with_cross_host
dnl  with_newlib
dnl  with_target_subdir
dnl plus
dnl  - the variables in GLIBCXX_CHECK_HOST / configure.host
dnl  - default settings for all AM_CONFITIONAL test variables
dnl  - lots of tools, like CC and CXX
dnl
AC_DEFUN([GLIBCXX_CONFIGURE], [
  # Keep these sync'd with the list in Makefile.am.  The first provides an
  # expandable list at autoconf time; the second provides an expandable list
  # (i.e., shell variable) at configure time.
  m4_define([glibcxx_SUBDIRS],[include libmath libsupc++ src po testsuite])
  SUBDIRS='glibcxx_SUBDIRS'

  # These need to be absolute paths, yet at the same time need to
  # canonicalize only relative paths, because then amd will not unmount
  # drives. Thus the use of PWDCMD: set it to 'pawd' or 'amq -w' if using amd.
  glibcxx_builddir=`${PWDCMD-pwd}`
  case $srcdir in
    [\\/$]* | ?:[\\/]*) glibcxx_srcdir=${srcdir} ;;
    *) glibcxx_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} || echo "$srcdir"` ;;
  esac
  toplevel_srcdir=${glibcxx_srcdir}/..
  AC_SUBST(glibcxx_builddir)
  AC_SUBST(glibcxx_srcdir)
  AC_SUBST(toplevel_srcdir)

  # We use these options to decide which functions to include.  They are
  # set from the top level.
  AC_ARG_WITH([target-subdir],
    AC_HELP_STRING([--with-target-subdir=SUBDIR],
                   [configuring in a subdirectory]))

  AC_ARG_WITH([cross-host],
    AC_HELP_STRING([--with-cross-host=HOST],
                   [configuring with a cross compiler]))

  AC_ARG_WITH([newlib],
    AC_HELP_STRING([--with-newlib],
                   [assume newlib as a system C library]))

  # We're almost certainly being configured before anything else which uses
  # C++, so all of our AC_PROG_* discoveries will be cached.  It's vital that
  # we not cache the value of CXX that we "discover" here, because it's set
  # to something unique for us and libjava.  Other target libraries need to
  # find CXX for themselves.  We yank the rug out from under the normal AC_*
  # process by sneakily renaming the cache variable.  This also lets us debug
  # the value of "our" CXX in postmortems.
  #
  # We must also force CXX to /not/ be a precious variable, otherwise the
  # wrong (non-multilib-adjusted) value will be used in multilibs.  This
  # little trick also affects CPPFLAGS, CXXFLAGS, and LDFLAGS.  And as a side
  # effect, CXXFLAGS is no longer automagically subst'd, so we have to do
  # that ourselves.  Un-preciousing AC_PROG_CC also affects CC and CFLAGS.
  #
  # -fno-builtin must be present here so that a non-conflicting form of
  # std::exit can be guessed by AC_PROG_CXX, and used in later tests.

  m4_define([ac_cv_prog_CXX],[glibcxx_cv_prog_CXX])
  m4_rename([_AC_ARG_VAR_PRECIOUS],[glibcxx_PRECIOUS])
  m4_define([_AC_ARG_VAR_PRECIOUS],[])
  save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-builtin"
  AC_PROG_CC
  AC_PROG_CXX
  CXXFLAGS="$save_CXXFLAGS"
  m4_rename([glibcxx_PRECIOUS],[_AC_ARG_VAR_PRECIOUS])
  AC_SUBST(CFLAGS)
  AC_SUBST(CXXFLAGS)

  # For directory versioning (e.g., headers) and other variables.
  AC_MSG_CHECKING([for GCC version number])
  gcc_version=`$CXX -dumpversion`
  AC_MSG_RESULT($gcc_version)

  # Will set LN_S to either 'ln -s', 'ln', or 'cp -p' (if linking isn't
  # available).  Uncomment the next line to force a particular method.
  AC_PROG_LN_S
  #LN_S='cp -p'

  AC_CHECK_TOOL(AS, as)
  AC_CHECK_TOOL(AR, ar)
  AC_CHECK_TOOL(RANLIB, ranlib, ranlib-not-found-in-path-error)

  AM_MAINTAINER_MODE

  # Set up safe default values for all subsequent AM_CONDITIONAL tests
  # which are themselves conditionally expanded.
  ## (Right now, this only matters for enable_wchar_t, but nothing prevents
  ## other macros from doing the same.  This should be automated.)  -pme
  need_libmath=no
  enable_wchar_t=no
  #enable_libstdcxx_debug=no
  #enable_libstdcxx_pch=no
  #enable_cheaders=c
  #c_compatibility=no
  #enable_abi_check=no
  #enable_symvers=no
  #enable_hosted_libstdcxx=yes

  # Find platform-specific directories containing configuration info.
  # Also possibly modify flags used elsewhere, as needed by the platform.
  GLIBCXX_CHECK_HOST
])


m4_include([linkage.m4])
m4_include([../config/no-executables.m4])


dnl
dnl Tests for newer compiler features, or features that are present in newer
dnl compiler versions but not older compiler versions still in use, should
dnl be placed here.
dnl
dnl Defines:
dnl  WERROR='-Werror' if requested and possible; g++'s that lack the
dnl   new inlining code or the new system_header pragma will die on -Werror.
dnl   Leave it out by default and use maint-mode to use it.
dnl  SECTION_FLAGS='-ffunction-sections -fdata-sections' if
dnl   compiler supports it and the user has not requested debug mode.
dnl
AC_DEFUN([GLIBCXX_CHECK_COMPILER_FEATURES], [
  # All these tests are for C++; save the language and the compiler flags.
  # The CXXFLAGS thing is suspicious, but based on similar bits previously
  # found in GLIBCXX_CONFIGURE.
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_test_CXXFLAGS="${CXXFLAGS+set}"
  ac_save_CXXFLAGS="$CXXFLAGS"

  # Check for maintainer-mode bits.
  if test x"$USE_MAINTAINER_MODE" = xno; then
    WERROR=''
  else
    WERROR='-Werror'
  fi

  # Check for -ffunction-sections -fdata-sections
  AC_MSG_CHECKING([for g++ that supports -ffunction-sections -fdata-sections])
  CXXFLAGS='-Werror -ffunction-sections -fdata-sections'
  AC_TRY_COMPILE(, [int foo;], [ac_fdsections=yes], [ac_fdsections=no])
  if test "$ac_test_CXXFLAGS" = set; then
    CXXFLAGS="$ac_save_CXXFLAGS"
  else
    # this is the suspicious part
    CXXFLAGS=''
  fi
  if test x"$ac_fdsections" = x"yes"; then
    SECTION_FLAGS='-ffunction-sections -fdata-sections'
  fi
  AC_MSG_RESULT($ac_fdsections)

  AC_LANG_RESTORE
  AC_SUBST(WERROR)
  AC_SUBST(SECTION_FLAGS)
])


dnl
dnl If GNU ld is in use, check to see if tricky linker opts can be used.  If
dnl the native linker is in use, all variables will be defined to something
dnl safe (like an empty string).
dnl
dnl Defines:
dnl  SECTION_LDFLAGS='-Wl,--gc-sections' if possible
dnl  OPT_LDFLAGS='-Wl,-O1' if possible
dnl  LD (as a side effect of testing)
dnl Sets:
dnl  with_gnu_ld
dnl  glibcxx_gnu_ld_version (possibly)
dnl
dnl The last will be a single integer, e.g., version 1.23.45.0.67.89 will
dnl set glibcxx_gnu_ld_version to 12345.  Zeros cause problems.
dnl
AC_DEFUN([GLIBCXX_CHECK_LINKER_FEATURES], [
  # If we're not using GNU ld, then there's no point in even trying these
  # tests.  Check for that first.  We should have already tested for gld
  # by now (in libtool), but require it now just to be safe...
  test -z "$SECTION_LDFLAGS" && SECTION_LDFLAGS=''
  test -z "$OPT_LDFLAGS" && OPT_LDFLAGS=''
  AC_REQUIRE([AC_PROG_LD])
  AC_REQUIRE([AC_PROG_AWK])

  # The name set by libtool depends on the version of libtool.  Shame on us
  # for depending on an impl detail, but c'est la vie.  Older versions used
  # ac_cv_prog_gnu_ld, but now it's lt_cv_prog_gnu_ld, and is copied back on
  # top of with_gnu_ld (which is also set by --with-gnu-ld, so that actually
  # makes sense).  We'll test with_gnu_ld everywhere else, so if that isn't
  # set (hence we're using an older libtool), then set it.
  if test x${with_gnu_ld+set} != xset; then
    if test x${ac_cv_prog_gnu_ld+set} != xset; then
      # We got through "ac_require(ac_prog_ld)" and still not set?  Huh?
      with_gnu_ld=no
    else
      with_gnu_ld=$ac_cv_prog_gnu_ld
    fi
  fi

  # Start by getting the version number.  I think the libtool test already
  # does some of this, but throws away the result.
  changequote(,)
  ldver=`$LD --version 2>/dev/null | head -1 | \
         sed -e 's/GNU ld version \([0-9.][0-9.]*\).*/\1/'`
  changequote([,])
  glibcxx_gnu_ld_version=`echo $ldver | \
         $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`

  # Set --gc-sections.
  if test "$with_gnu_ld" = "notbroken"; then
    # GNU ld it is!  Joy and bunny rabbits!

    # All these tests are for C++; save the language and the compiler flags.
    # Need to do this so that g++ won't try to link in libstdc++
    ac_test_CFLAGS="${CFLAGS+set}"
    ac_save_CFLAGS="$CFLAGS"
    CFLAGS='-x c++  -Wl,--gc-sections'

    # Check for -Wl,--gc-sections
    # XXX This test is broken at the moment, as symbols required for linking
    # are now in libsupc++ (not built yet).  In addition, this test has
    # cored on solaris in the past.  In addition, --gc-sections doesn't
    # really work at the moment (keeps on discarding used sections, first
    # .eh_frame and now some of the glibc sections for iconv).
    # Bzzzzt.  Thanks for playing, maybe next time.
    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
    AC_TRY_RUN([
     int main(void)
     {
       try { throw 1; }
       catch (...) { };
       return 0;
     }
    ], [ac_sectionLDflags=yes],[ac_sectionLDflags=no], [ac_sectionLDflags=yes])
    if test "$ac_test_CFLAGS" = set; then
      CFLAGS="$ac_save_CFLAGS"
    else
      # this is the suspicious part
      CFLAGS=''
    fi
    if test "$ac_sectionLDflags" = "yes"; then
      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
    fi
    AC_MSG_RESULT($ac_sectionLDflags)
  fi

  # Set linker optimization flags.
  if test x"$with_gnu_ld" = x"yes"; then
    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
  fi

  AC_SUBST(SECTION_LDFLAGS)
  AC_SUBST(OPT_LDFLAGS)
])


dnl
dnl Check to see if this target can enable the wchar_t parts.
dnl If --disable-c-mbchar was given, no wchar_t stuff is enabled.  (This
dnl must have been previously checked.)  By default, wide characters are
dnl disabled.
dnl
dnl Defines:
dnl  HAVE_MBSTATE_T if mbstate_t is not in wchar.h
dnl  _GLIBCXX_USE_WCHAR_T if all the bits are found.
dnl
AC_DEFUN([GLIBCXX_CHECK_WCHAR_T_SUPPORT], [
  # Test wchar.h for mbstate_t, which is needed for char_traits and
  # others even if wchar_t support is not on.
  AC_MSG_CHECKING([for mbstate_t])
  AC_TRY_COMPILE([#include <wchar.h>],
  [mbstate_t teststate;],
  have_mbstate_t=yes, have_mbstate_t=no)
  AC_MSG_RESULT($have_mbstate_t)
  if test x"$have_mbstate_t" = xyes; then
    AC_DEFINE(HAVE_MBSTATE_T)
  fi

  # Sanity check for existence of ISO C99 headers for extended encoding.
  AC_CHECK_HEADERS(wchar.h, ac_has_wchar_h=yes, ac_has_wchar_h=no)
  AC_CHECK_HEADERS(wctype.h, ac_has_wctype_h=yes, ac_has_wctype_h=no)

  # Only continue checking if the ISO C99 headers exist and support is on.
  if test x"$ac_has_wchar_h" = xyes &&
     test x"$ac_has_wctype_h" = xyes &&
     test x"$enable_c_mbchar" != xno; then

    # Test wchar.h for WCHAR_MIN, WCHAR_MAX, which is needed before
    # numeric_limits can instantiate type_traits<wchar_t>
    AC_MSG_CHECKING([for WCHAR_MIN and WCHAR_MAX])
    AC_TRY_COMPILE([#include <wchar.h>],
    [int i = WCHAR_MIN; int j = WCHAR_MAX;],
    has_wchar_minmax=yes, has_wchar_minmax=no)
    AC_MSG_RESULT($has_wchar_minmax)

    # Test wchar.h for WEOF, which is what we use to determine whether
    # to specialize for char_traits<wchar_t> or not.
    AC_MSG_CHECKING([for WEOF])
    AC_TRY_COMPILE([
      #include <wchar.h>
      #include <stddef.h>],
    [wint_t i = WEOF;],
    has_weof=yes, has_weof=no)
    AC_MSG_RESULT($has_weof)

    # Tests for wide character functions used in char_traits<wchar_t>.
    ac_wfuncs=yes
    AC_CHECK_FUNCS([wcslen wmemchr wmemcmp wmemcpy wmemmove wmemset],
    [],[ac_wfuncs=no])

    # Checks for names injected into std:: by the c_std headers.
    AC_CHECK_FUNCS([btowc wctob fgetwc fgetws fputwc fputws fwide \
    fwprintf fwscanf swprintf swscanf vfwprintf vswprintf \
    vwprintf wprintf wscanf getwc getwchar mbsinit mbrlen mbrtowc \
    mbsrtowcs wcsrtombs putwc putwchar ungetwc wcrtomb wcstod wcstol \
    wcstoul wcscpy wcsncpy wcscat wcsncat wcscmp wcscoll wcsncmp wcsxfrm \
    wcscspn wcsspn wcstok wcsftime wcschr wcspbrk wcsrchr wcsstr],
    [],[ac_wfuncs=no])

    # Checks for wide character functions that are not required
    # for basic wchar_t support.  Don't disable support if they are missing.
    # Injection of these is wrapped with guard macros.
    AC_CHECK_FUNCS([vfwscanf vswscanf vwscanf wcstof iswblank],[],[])

    AC_MSG_CHECKING([for ISO C99 wchar_t support])
    if test x"$has_weof" = xyes &&
       test x"$has_wchar_minmax" = xyes &&
       test x"$ac_wfuncs" = xyes;
    then
      ac_isoC99_wchar_t=yes
    else
      ac_isoC99_wchar_t=no
    fi
    AC_MSG_RESULT($ac_isoC99_wchar_t)

    # Use iconv for wchar_t to char conversions. As such, check for
    # X/Open Portability Guide, version 2 features (XPG2).
    AC_CHECK_HEADER(iconv.h, ac_has_iconv_h=yes, ac_has_iconv_h=no)
    AC_CHECK_HEADER(langinfo.h, ac_has_langinfo_h=yes, ac_has_langinfo_h=no)

    # Check for existence of libiconv.a providing XPG2 wchar_t support.
    AC_CHECK_LIB(iconv, iconv, libiconv="-liconv")
    ac_save_LIBS="$LIBS"
    LIBS="$LIBS $libiconv"

    AC_CHECK_FUNCS([iconv_open iconv_close iconv nl_langinfo],
    [ac_XPG2funcs=yes], [ac_XPG2funcs=no])

    LIBS="$ac_save_LIBS"

    AC_MSG_CHECKING([for XPG2 wchar_t support])
    if test x"$ac_has_iconv_h" = xyes &&
       test x"$ac_has_langinfo_h" = xyes &&
       test x"$ac_XPG2funcs" = xyes;
    then
      ac_XPG2_wchar_t=yes
    else
      ac_XPG2_wchar_t=no
    fi
    AC_MSG_RESULT($ac_XPG2_wchar_t)

    # At the moment, only enable wchar_t specializations if all the
    # above support is present.
    if test x"$ac_isoC99_wchar_t" = xyes &&
       test x"$ac_XPG2_wchar_t" = xyes;
    then
      AC_DEFINE(_GLIBCXX_USE_WCHAR_T)
      enable_wchar_t=yes
    fi
  fi
  AC_MSG_CHECKING([for enabled wchar_t specializations])
  AC_MSG_RESULT($enable_wchar_t)
])


dnl
dnl Check for headers for, and arguments to, the setrlimit() function.
dnl Used only in testsuite_hooks.h.  Called from GLIBCXX_CONFIGURE_TESTSUITE.
dnl
dnl Defines:
dnl  _GLIBCXX_MEM_LIMITS if we can set artificial limits on memory
dnl  various HAVE_MEMLIMIT_* for individual limit names
dnl
AC_DEFUN([GLIBCXX_CHECK_SETRLIMIT_ancilliary], [
  AC_TRY_COMPILE(
    [#include <unistd.h>
     #include <sys/time.h>
     #include <sys/resource.h>
    ],
    [ int f = RLIMIT_$1 ; ],
    [glibcxx_mresult=1], [glibcxx_mresult=0])
  AC_DEFINE_UNQUOTED(HAVE_MEMLIMIT_$1, $glibcxx_mresult,
                     [Only used in build directory testsuite_hooks.h.])
])

AC_DEFUN([GLIBCXX_CHECK_SETRLIMIT], [
  setrlimit_have_headers=yes
  AC_CHECK_HEADERS(unistd.h sys/time.h sys/resource.h,
                   [],
                   [setrlimit_have_headers=no])
  # If don't have the headers, then we can't run the tests now, and we
  # won't be seeing any of these during testsuite compilation.
  if test $setrlimit_have_headers = yes; then
    # Can't do these in a loop, else the resulting syntax is wrong.
    GLIBCXX_CHECK_SETRLIMIT_ancilliary(DATA)
    GLIBCXX_CHECK_SETRLIMIT_ancilliary(RSS)
    GLIBCXX_CHECK_SETRLIMIT_ancilliary(VMEM)
    GLIBCXX_CHECK_SETRLIMIT_ancilliary(AS)

    # Check for rlimit, setrlimit.
    AC_CACHE_VAL(ac_setrlimit, [
      AC_TRY_COMPILE(
        [#include <unistd.h>
         #include <sys/time.h>
         #include <sys/resource.h>
        ],
        [struct rlimit r;
         setrlimit(0, &r);],
        [ac_setrlimit=yes], [ac_setrlimit=no])
    ])
  fi

  AC_MSG_CHECKING([for testsuite memory limit support])
  if test $setrlimit_have_headers = yes && test $ac_setrlimit = yes; then
    ac_mem_limits=yes
    AC_DEFINE(_GLIBCXX_MEM_LIMITS)
  else
    ac_mem_limits=no
  fi
  AC_MSG_RESULT($ac_mem_limits)
])


dnl
dnl Check whether S_ISREG (Posix) or S_IFREG is available in <sys/stat.h>.
dnl Define HAVE_S_ISREG / HAVE_S_IFREG appropriately.
dnl
AC_DEFUN([GLIBCXX_CHECK_S_ISREG_OR_S_IFREG], [
  AC_CACHE_VAL(glibcxx_cv_S_ISREG, [
    AC_TRY_LINK(
      [#include <sys/stat.h>],
      [struct stat buffer;
       fstat(0, &buffer);
       S_ISREG(buffer.st_mode);],
      [glibcxx_cv_S_ISREG=yes],
      [glibcxx_cv_S_ISREG=no])
  ])
  AC_CACHE_VAL(glibcxx_cv_S_IFREG, [
    AC_TRY_LINK(
      [#include <sys/stat.h>],
      [struct stat buffer;
       fstat(0, &buffer);
       S_IFREG & buffer.st_mode;],
      [glibcxx_cv_S_IFREG=yes],
      [glibcxx_cv_S_IFREG=no])
  ])
  if test $glibcxx_cv_S_ISREG = yes; then
    AC_DEFINE(HAVE_S_ISREG)
  elif test $glibcxx_cv_S_IFREG = yes; then
    AC_DEFINE(HAVE_S_IFREG)
  fi
])


dnl
dnl Check whether poll is available in <poll.h>, and define HAVE_POLL.
dnl
AC_DEFUN([GLIBCXX_CHECK_POLL], [
  AC_CACHE_VAL(glibcxx_cv_POLL, [
    AC_TRY_LINK(
      [#include <poll.h>],
      [struct pollfd pfd[1];
       pfd[0].events = POLLIN;
       poll(pfd, 1, 0);],
      [glibcxx_cv_POLL=yes],
      [glibcxx_cv_POLL=no])
  ])
  if test $glibcxx_cv_POLL = yes; then
    AC_DEFINE(HAVE_POLL)
  fi
])


dnl
dnl Check whether writev is available in <sys/uio.h>, and define HAVE_WRITEV.
dnl
AC_DEFUN([GLIBCXX_CHECK_WRITEV], [
  AC_CACHE_VAL(glibcxx_cv_WRITEV, [
    AC_TRY_LINK(
      [#include <sys/uio.h>],
      [struct iovec iov[2];
       writev(0, iov, 0);],
      [glibcxx_cv_WRITEV=yes],
      [glibcxx_cv_WRITEV=no])
  ])
  if test $glibcxx_cv_WRITEV = yes; then
    AC_DEFINE(HAVE_WRITEV)
  fi
])


dnl
dnl Check whether int64_t is available in <stdint.h>, and define HAVE_INT64_T.
dnl
AC_DEFUN([GLIBCXX_CHECK_INT64_T], [
  AC_CACHE_VAL(glibcxx_cv_INT64_T, [
    AC_TRY_COMPILE(
      [#include <stdint.h>],
      [int64_t var;],
      [glibcxx_cv_INT64_T=yes],
      [glibcxx_cv_INT64_T=no])
  ])
  if test $glibcxx_cv_INT64_T = yes; then
    AC_DEFINE(HAVE_INT64_T)
  fi
])


dnl
dnl Check whether LFS support is available.
dnl
AC_DEFUN([GLIBCXX_CHECK_LFS], [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"	
  AC_CACHE_VAL(glibcxx_cv_LFS, [
    AC_TRY_LINK(
      [#include <unistd.h>
       #include <stdio.h>
      ],
      [FILE* fp;
       fopen64("t", "w");
       fseeko64(fp, 0, SEEK_CUR);
       ftello64(fp);
       lseek64(1, 0, SEEK_CUR);],	
      [glibcxx_cv_LFS=yes],
      [glibcxx_cv_LFS=no])
  ])
  if test $glibcxx_cv_LFS = yes; then
    AC_DEFINE(_GLIBCXX_USE_LFS)
  fi
  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])


dnl
dnl Does any necessary configuration of the testsuite directory.  Generates
dnl the testsuite_hooks.h header.
dnl
dnl GLIBCXX_ENABLE_SYMVERS and GLIBCXX_IS_NATIVE must be done before this.
dnl
dnl Sets:
dnl  enable_abi_check / GLIBCXX_TEST_ABI
dnl Substs:
dnl  baseline_dir
dnl
AC_DEFUN([GLIBCXX_CONFIGURE_TESTSUITE], [
  if $GLIBCXX_IS_NATIVE && test $is_hosted = yes; then
    # Do checks for memory limit functions.
    GLIBCXX_CHECK_SETRLIMIT

    # Look for setenv, so that extended locale tests can be performed.
    GLIBCXX_CHECK_STDLIB_DECL_AND_LINKAGE_3(setenv)

    if test $enable_symvers = no; then
      enable_abi_check=no
    else
      case "$host" in
        *-*-cygwin*)
          enable_abi_check=no ;;
        *)
          enable_abi_check=yes ;;
      esac
    fi
  else
    # Only build this as native, since automake does not understand
    # CXX_FOR_BUILD.
    enable_abi_check=no
  fi

  # Export file names for ABI checking.
  baseline_dir="$glibcxx_srcdir/config/abi/${abi_baseline_pair}\$(MULTISUBDIR)"
  AC_SUBST(baseline_dir)

  GLIBCXX_CONDITIONAL(GLIBCXX_TEST_WCHAR_T, test $enable_wchar_t = yes)
  GLIBCXX_CONDITIONAL(GLIBCXX_TEST_ABI, test $enable_abi_check = yes)
])


dnl
dnl Set up *_INCLUDES variables for all sundry Makefile.am's.
dnl
dnl Substs:
dnl  GLIBCXX_INCLUDES
dnl  TOPLEVEL_INCLUDES
dnl
AC_DEFUN([GLIBCXX_EXPORT_INCLUDES], [
  # Used for every C++ compile we perform.
  GLIBCXX_INCLUDES="\
-I$glibcxx_builddir/include/$host_alias \
-I$glibcxx_builddir/include \
-I$glibcxx_srcdir/libsupc++"

  # For Canadian crosses, pick this up too.
  if test $CANADIAN = yes; then
    GLIBCXX_INCLUDES="$GLIBCXX_INCLUDES -I\${includedir}"
  fi

  # Stuff in the actual top level.  Currently only used by libsupc++ to
  # get unwind* headers from the gcc dir.
  #TOPLEVEL_INCLUDES='-I$(toplevel_srcdir)/gcc -I$(toplevel_srcdir)/include'
  TOPLEVEL_INCLUDES='-I$(toplevel_srcdir)/gcc'

  # Now, export this to all the little Makefiles....
  AC_SUBST(GLIBCXX_INCLUDES)
  AC_SUBST(TOPLEVEL_INCLUDES)
])


dnl
dnl Set up *_FLAGS and *FLAGS variables for all sundry Makefile.am's.
dnl (SECTION_FLAGS is done under CHECK_COMPILER_FEATURES.)
dnl
dnl Substs:
dnl  OPTIMIZE_CXXFLAGS
dnl  WARN_FLAGS
dnl
AC_DEFUN([GLIBCXX_EXPORT_FLAGS], [
  # Optimization flags that are probably a good idea for thrill-seekers. Just
  # uncomment the lines below and make, everything else is ready to go...
  # OPTIMIZE_CXXFLAGS = -O3 -fstrict-aliasing -fvtable-gc
  OPTIMIZE_CXXFLAGS=
  AC_SUBST(OPTIMIZE_CXXFLAGS)

  WARN_FLAGS='-Wall -W -Wwrite-strings -Wcast-qual'
  AC_SUBST(WARN_FLAGS)
])


dnl
dnl All installation directory information is determined here.
dnl
dnl Substs:
dnl  gxx_install_dir
dnl  glibcxx_prefixdir
dnl  glibcxx_toolexecdir
dnl  glibcxx_toolexeclibdir
dnl
dnl Assumes cross_compiling bits already done, and with_cross_host in
dnl particular.
dnl
AC_DEFUN([GLIBCXX_EXPORT_INSTALL_INFO], [
  glibcxx_toolexecdir=no
  glibcxx_toolexeclibdir=no
  glibcxx_prefixdir=$prefix

  AC_MSG_CHECKING([for gxx-include-dir])
  AC_ARG_WITH([gxx-include-dir],
    AC_HELP_STRING([--with-gxx-include-dir=DIR],
                   [installation directory for include files]),
    [case "$withval" in
      yes) AC_MSG_ERROR([Missing directory for --with-gxx-include-dir]) ;;
      no)  gxx_include_dir=no ;;
      *)   gxx_include_dir=$withval ;;
     esac],
    [gxx_include_dir=no])
  AC_MSG_RESULT($gxx_include_dir)

  AC_MSG_CHECKING([for --enable-version-specific-runtime-libs])
  AC_ARG_ENABLE([version-specific-runtime-libs],
    AC_HELP_STRING([--enable-version-specific-runtime-libs],
                   [Specify that runtime libraries should be installed in a compiler-specific directory]),
    [case "$enableval" in
      yes) version_specific_libs=yes ;;
      no)  version_specific_libs=no ;;
      *)   AC_MSG_ERROR([Unknown argument to enable/disable version-specific libs]);;
     esac],
    [version_specific_libs=no])
  AC_MSG_RESULT($version_specific_libs)

  # Default case for install directory for include files.
  if test $version_specific_libs = no && test $gxx_include_dir = no; then
    gxx_include_dir='${prefix}'/include/c++/${gcc_version}
  fi

  # Version-specific runtime libs processing.
  if test $version_specific_libs = yes; then
    # Need the gcc compiler version to know where to install libraries
    # and header files if --enable-version-specific-runtime-libs option
    # is selected.  FIXME: these variables are misnamed, there are
    # no executables installed in _toolexecdir or _toolexeclibdir.
    if test x"$gxx_include_dir" = x"no"; then
      gxx_include_dir='${libdir}/gcc/${host_alias}/'$gcc_version/include/c++
    fi
    glibcxx_toolexecdir='${libdir}/gcc/${host_alias}'
    glibcxx_toolexeclibdir='${toolexecdir}/'$gcc_version'$(MULTISUBDIR)'
  fi

  # Calculate glibcxx_toolexecdir, glibcxx_toolexeclibdir
  # Install a library built with a cross compiler in tooldir, not libdir.
  if test x"$glibcxx_toolexecdir" = x"no"; then
    if test -n "$with_cross_host" &&
       test x"$with_cross_host" != x"no"; then
      glibcxx_toolexecdir='${exec_prefix}/${host_alias}'
      glibcxx_toolexeclibdir='${toolexecdir}/lib'
    else
      glibcxx_toolexecdir='${libdir}/gcc/${host_alias}'
      glibcxx_toolexeclibdir='${libdir}'
    fi
    multi_os_directory=`$CXX -print-multi-os-directory`
    case $multi_os_directory in
      .) ;; # Avoid trailing /.
      *) glibcxx_toolexeclibdir=$glibcxx_toolexeclibdir/$multi_os_directory ;;
    esac
  fi

  AC_MSG_CHECKING([for install location])
  AC_MSG_RESULT($gxx_include_dir)

  AC_SUBST(glibcxx_prefixdir)
  AC_SUBST(gxx_include_dir)
  AC_SUBST(glibcxx_toolexecdir)
  AC_SUBST(glibcxx_toolexeclibdir)
])


dnl
dnl GLIBCXX_ENABLE
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING)
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, permit a|b|c)
dnl    (FEATURE, DEFAULT, HELP-ARG, HELP-STRING, SHELL-CODE-HANDLER)
dnl
dnl See docs/html/17_intro/configury.html#enable for documentation.
dnl
m4_define([GLIBCXX_ENABLE],[dnl
m4_define([_g_switch],[--enable-$1])dnl
m4_define([_g_help],[AC_HELP_STRING(_g_switch$3,[$4 @<:@default=$2@:>@])])dnl
 AC_ARG_ENABLE($1,_g_help,
  m4_bmatch([$5],
   [^permit ],
     [[
      case "$enableval" in
       m4_bpatsubst([$5],[permit ])) ;;
       *) AC_MSG_ERROR(Unknown argument to enable/disable $1) ;;
          dnl Idea for future:  generate a URL pointing to
          dnl "onlinedocs/configopts.html#whatever"
      esac
     ]],
   [^$],
     [[
      case "$enableval" in
       yes|no) ;;
       *) AC_MSG_ERROR(Argument to enable/disable $1 must be yes or no) ;;
      esac
     ]],
   [[$5]]),
  [enable_]m4_bpatsubst([$1],-,_)[=][$2])
m4_undefine([_g_switch])dnl
m4_undefine([_g_help])dnl
])


dnl
dnl Check for ISO/IEC 9899:1999 "C99" support.
dnl
dnl --enable-c99 defines _GLIBCXX_USE_C99
dnl --disable-c99 leaves _GLIBCXX_USE_C99 undefined
dnl  +  Usage:  GLIBCXX_ENABLE_C99[(DEFAULT)]
dnl       Where DEFAULT is either `yes' or `no'.
dnl  +  If 'C99' stuff is not available, ignores DEFAULT and sets `no'.
dnl
AC_DEFUN([GLIBCXX_ENABLE_C99], [
  GLIBCXX_ENABLE(c99,$1,,[turns on ISO/IEC 9899:1999 support])

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS

  # Check for the existence of <math.h> functions used if C99 is enabled.
  ac_c99_math=yes;
  AC_MSG_CHECKING([for ISO C99 support in <math.h>])
  AC_TRY_COMPILE([#include <math.h>],[fpclassify(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isfinite(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isinf(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isnan(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isnormal(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[signbit(0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isgreater(0.0,0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],
                 [isgreaterequal(0.0,0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[isless(0.0,0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],[islessequal(0.0,0.0);],,[ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],
                 [islessgreater(0.0,0.0);],, [ac_c99_math=no])
  AC_TRY_COMPILE([#include <math.h>],
                 [isunordered(0.0,0.0);],, [ac_c99_math=no])
  AC_MSG_RESULT($ac_c99_math)

  if test x"$ac_c99_math" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_MATH)
  fi

  # Check for the existence in <stdio.h> of vscanf, et. al.
  ac_c99_stdio=yes;
  AC_MSG_CHECKING([for ISO C99 support in <stdio.h>])
  AC_TRY_COMPILE([#include <stdio.h>],
                 [snprintf("12", 0, "%i");],, [ac_c99_stdio=no])
  AC_TRY_COMPILE([#include <stdio.h>
                  #include <stdarg.h>
                  void foo(char* fmt, ...)
                  {va_list args; va_start(args, fmt);
                  vfscanf(stderr, "%i", args);}],
                  [],, [ac_c99_stdio=no])
  AC_TRY_COMPILE([#include <stdio.h>
                  #include <stdarg.h>
                  void foo(char* fmt, ...)
                  {va_list args; va_start(args, fmt);
                  vscanf("%i", args);}],
                  [],, [ac_c99_stdio=no])
  AC_TRY_COMPILE([#include <stdio.h>
                  #include <stdarg.h>
                  void foo(char* fmt, ...)
                  {va_list args; va_start(args, fmt);
                  vsnprintf(fmt, 0, "%i", args);}],
                  [],, [ac_c99_stdio=no])
  AC_TRY_COMPILE([#include <stdio.h>
                  #include <stdarg.h>
                  void foo(char* fmt, ...)
                  {va_list args; va_start(args, fmt);
                  vsscanf(fmt, "%i", args);}],
                  [],, [ac_c99_stdio=no])
  AC_MSG_RESULT($ac_c99_stdio)

  # Check for the existence in <stdlib.h> of lldiv_t, et. al.
  ac_c99_stdlib=yes;
  AC_MSG_CHECKING([for lldiv_t declaration])
  AC_CACHE_VAL(ac_c99_lldiv_t, [
  AC_TRY_COMPILE([#include <stdlib.h>],
                   [ lldiv_t mydivt;],
                   [ac_c99_lldiv_t=yes], [ac_c99_lldiv_t=no])
  ])
  AC_MSG_RESULT($ac_c99_lldiv_t)

  AC_MSG_CHECKING([for ISO C99 support in <stdlib.h>])
  AC_TRY_COMPILE([#include <stdlib.h>],
                 [char* tmp; strtof("gnu", &tmp);],, [ac_c99_stdlib=no])
  AC_TRY_COMPILE([#include <stdlib.h>],
                 [char* tmp; strtold("gnu", &tmp);],, [ac_c99_stdlib=no])
  AC_TRY_COMPILE([#include <stdlib.h>], [llabs(10);],, [ac_c99_stdlib=no])
  AC_TRY_COMPILE([#include <stdlib.h>], [lldiv(10,1);],, [ac_c99_stdlib=no])
  AC_TRY_COMPILE([#include <stdlib.h>], [atoll("10");],, [ac_c99_stdlib=no])
  AC_TRY_COMPILE([#include <stdlib.h>], [_Exit(0);],, [ac_c99_stdlib=no])
  if test x"$ac_c99_lldiv_t" = x"no"; then
    ac_c99_stdlib=no;
  fi;
  AC_MSG_RESULT($ac_c99_stdlib)

  # Check for the existence of <wchar.h> functions used if C99 is enabled.
  # XXX the wchar.h checks should be rolled into the general C99 bits.
  ac_c99_wchar=yes;
  AC_MSG_CHECKING([for additional ISO C99 support in <wchar.h>])
  AC_TRY_COMPILE([#include <wchar.h>],
                 [wcstold(L"10.0", NULL);],, [ac_c99_wchar=no])
  AC_TRY_COMPILE([#include <wchar.h>],
                 [wcstoll(L"10", NULL, 10);],, [ac_c99_wchar=no])
  AC_TRY_COMPILE([#include <wchar.h>],
                 [wcstoull(L"10", NULL, 10);],, [ac_c99_wchar=no])
  AC_MSG_RESULT($ac_c99_wchar)

  AC_MSG_CHECKING([for enabled ISO C99 support])
  if test x"$ac_c99_math" = x"no" ||
     test x"$ac_c99_stdio" = x"no" ||
     test x"$ac_c99_stdlib" = x"no" ||
     test x"$ac_c99_wchar" = x"no"; then
    enable_c99=no;
  fi;
  AC_MSG_RESULT($enable_c99)

  if test x"$ac_99_math" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_MATH)
  fi

  # Option parsed, now set things appropriately
  if test x"$enable_c99" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99)
  fi

  AC_LANG_RESTORE
])


dnl
dnl Check for what type of C headers to use.
dnl
dnl --enable-cheaders= [does stuff].
dnl --disable-cheaders [does not do anything, really].
dnl  +  Usage:  GLIBCXX_ENABLE_CHEADERS[(DEFAULT)]
dnl       Where DEFAULT is either `c' or `c_std'.
dnl
AC_DEFUN([GLIBCXX_ENABLE_CHEADERS], [
  GLIBCXX_ENABLE(cheaders,$1,[=KIND],
    [construct "C" headers for g++], [permit c|c_std])
  AC_MSG_NOTICE("C" header strategy set to $enable_cheaders)

  C_INCLUDE_DIR='${glibcxx_srcdir}/include/'$enable_cheaders

  AC_SUBST(C_INCLUDE_DIR)
  GLIBCXX_CONDITIONAL(GLIBCXX_C_HEADERS_C, test $enable_cheaders = c)
  GLIBCXX_CONDITIONAL(GLIBCXX_C_HEADERS_C_STD, test $enable_cheaders = c_std)
  GLIBCXX_CONDITIONAL(GLIBCXX_C_HEADERS_COMPATIBILITY, test $c_compatibility = yes)
])


dnl
dnl Check for which locale library to use.  The choice is mapped to
dnl a subdirectory of config/locale.
dnl
dnl Default is generic.
dnl
AC_DEFUN([GLIBCXX_ENABLE_CLOCALE], [
  AC_MSG_CHECKING([for C locale to use])
  GLIBCXX_ENABLE(clocale,auto,[@<:@=MODEL@:>@],
    [use MODEL for target locale package],
    [permit generic|gnu|ieee_1003.1-2001|yes|no|auto])
  
  # If they didn't use this option switch, or if they specified --enable
  # with no specific model, we'll have to look for one.  If they
  # specified --disable (???), do likewise.
  if test $enable_clocale = no || test $enable_clocale = yes; then
     enable_clocale=auto
  fi

  # Either a known package, or "auto"
  enable_clocale_flag=$enable_clocale

  # Probe for locale support if no specific model is specified.
  # Default to "generic".
  if test $enable_clocale_flag = auto; then
    case x${target_os} in
      xlinux* | xgnu* | xkfreebsd*-gnu | xknetbsd*-gnu)
        AC_EGREP_CPP([_GLIBCXX_ok], [
        #include <features.h>
        #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2)
          _GLIBCXX_ok
        #endif
        ], enable_clocale_flag=gnu, enable_clocale_flag=generic)

        # Test for bugs early in glibc-2.2.x series
          if test x$enable_clocale_flag = xgnu; then
          AC_TRY_RUN([
          #define _GNU_SOURCE 1
          #include <locale.h>
          #include <string.h>
          #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ > 2)
          extern __typeof(newlocale) __newlocale;
          extern __typeof(duplocale) __duplocale;
          extern __typeof(strcoll_l) __strcoll_l;
          #endif
          int main()
          {