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


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 the rest of the library configury.  At this point we have
dnl variables like $host.
dnl
dnl Sets:
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 doc 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)

  # 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

  # Check for uClibc since Linux platforms use different configuration
  # directories depending on the C library in use.
  AC_EGREP_CPP([_using_uclibc], [
  #include <stdio.h>
  #if __UCLIBC__
    _using_uclibc
  #endif
  ], uclibc=yes, uclibc=no)

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


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='-g -Werror -ffunction-sections -fdata-sections'
  AC_TRY_COMPILE([int foo; void bar() { };],, [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' and '-z,relro' if possible
dnl  LD (as a side effect of testing)
dnl Sets:
dnl  with_gnu_ld
dnl  glibcxx_ld_is_gold (set to "no" or "yes")
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.
  glibcxx_ld_is_gold=no
  if test x"$with_gnu_ld" = x"yes"; then
    AC_MSG_CHECKING([for ld version])
    changequote(,)
    if $LD --version 2>/dev/null | grep 'GNU gold' >/dev/null 2>&1; then
      glibcxx_ld_is_gold=yes
    fi
    ldver=`$LD --version 2>/dev/null | head -1 | \
           sed -e 's/GNU \(go\)\{0,1\}ld \(version \)\{0,1\}\(([^)]*) \)\{0,1\}\([0-9.][0-9.]*\).*/\4/'`
    changequote([,])
    glibcxx_gnu_ld_version=`echo $ldver | \
           $AWK -F. '{ if (NF<3) [$]3=0; print ([$]1*100+[$]2)*100+[$]3 }'`
    AC_MSG_RESULT($glibcxx_gnu_ld_version)
  fi

  # Set --gc-sections.
  glibcxx_have_gc_sections=no
  if test "$glibcxx_ld_is_gold" = "yes"; then
    if $LD --help 2>/dev/null | grep gc-sections >/dev/null 2>&1; then
      glibcxx_have_gc_sections=yes
    fi
  else
    glibcxx_gcsections_min_ld=21602
    if test x"$with_gnu_ld" = x"yes" && 
	test $glibcxx_gnu_ld_version -gt $glibcxx_gcsections_min_ld ; then
      glibcxx_have_gc_sections=yes
    fi
  fi
  if test "$glibcxx_have_gc_sections" = "yes"; then
    # Sufficiently young GNU ld it is!  Joy and bunny rabbits!
    # NB: This flag only works reliably after 2.16.1. Configure tests
    # for this are difficult, so hard wire a value that should work.

    ac_test_CFLAGS="${CFLAGS+set}"
    ac_save_CFLAGS="$CFLAGS"
    CFLAGS='-Wl,--gc-sections'

    # Check for -Wl,--gc-sections
    AC_MSG_CHECKING([for ld that supports -Wl,--gc-sections])
    AC_TRY_LINK([ int one(void) { return 1; }
     int two(void) { return 2; }
	], [ two(); ] , [ac_gcsections=yes], [ac_gcsections=no])
    if test "$ac_gcsections" = "yes"; then
      rm -f conftest.c
      touch conftest.c
      if $CC -c conftest.c; then
	if $LD --gc-sections -o conftest conftest.o 2>&1 | \
	   grep "Warning: gc-sections option ignored" > /dev/null; then
	  ac_gcsections=no
	fi
      fi
      rm -f conftest.c conftest.o conftest
    fi
    if test "$ac_gcsections" = "yes"; then
      SECTION_LDFLAGS="-Wl,--gc-sections $SECTION_LDFLAGS"
    fi
    AC_MSG_RESULT($ac_gcsections)

    if test "$ac_test_CFLAGS" = set; then
      CFLAGS="$ac_save_CFLAGS"
    else
      # this is the suspicious part
      CFLAGS=''
    fi
  fi

  # Set -z,relro.
  # Note this is only for shared objects.
  ac_ld_relro=no
  if test x"$with_gnu_ld" = x"yes"; then
    AC_MSG_CHECKING([for ld that supports -Wl,-z,relro])
    cxx_z_relo=`$LD -v --help 2>/dev/null | grep "z relro"`
    if test -n "$cxx_z_relo"; then
      OPT_LDFLAGS="-Wl,-z,relro"
      ac_ld_relro=yes
    fi
    AC_MSG_RESULT($ac_ld_relro)
  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 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_RES_LIMITS if we can set artificial resource limits 
dnl  various HAVE_LIMIT_* for individual limit names
dnl
AC_DEFUN([GLIBCXX_CHECK_SETRLIMIT_ancilliary], [
  AC_MSG_CHECKING([for RLIMIT_$1])
  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_LIMIT_$1, $glibcxx_mresult,
                     [Only used in build directory testsuite_hooks.h.])
  if test $glibcxx_mresult = 1 ; then res=yes ; else res=no ; fi
  AC_MSG_RESULT($res)
])

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)
    GLIBCXX_CHECK_SETRLIMIT_ancilliary(FSIZE)

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

  AC_MSG_CHECKING([for testsuite resource limits support])
  if test $setrlimit_have_headers = yes && test $glibcxx_cv_setrlimit = yes; then
    ac_res_limits=yes
    AC_DEFINE(_GLIBCXX_RES_LIMITS, 1,
              [Define if using setrlimit to set resource limits during
              "make check"])
  else
    ac_res_limits=no
  fi
  AC_MSG_RESULT($ac_res_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_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"

  AC_MSG_CHECKING([for S_ISREG or S_IFREG])
  AC_CACHE_VAL(glibcxx_cv_S_ISREG, [
    GCC_TRY_COMPILE_OR_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, [
    GCC_TRY_COMPILE_OR_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])
  ])
  res=no
  if test $glibcxx_cv_S_ISREG = yes; then
    AC_DEFINE(HAVE_S_ISREG, 1, 
              [Define if S_IFREG is available in <sys/stat.h>.])
    res=S_ISREG
  elif test $glibcxx_cv_S_IFREG = yes; then
    AC_DEFINE(HAVE_S_IFREG, 1,
              [Define if S_IFREG is available in <sys/stat.h>.])
    res=S_IFREG
  fi
  AC_MSG_RESULT($res)

  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])


dnl
dnl Check whether poll is available in <poll.h>, and define HAVE_POLL.
dnl
AC_DEFUN([GLIBCXX_CHECK_POLL], [

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"

  AC_MSG_CHECKING([for poll])
  AC_CACHE_VAL(glibcxx_cv_POLL, [
    GCC_TRY_COMPILE_OR_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 $glibcxx_cv_POLL = yes; then
    AC_DEFINE(HAVE_POLL, 1, [Define if poll is available in <poll.h>.])
  fi
  AC_MSG_RESULT($glibcxx_cv_POLL)

  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])


dnl
dnl Check whether writev is available in <sys/uio.h>, and define HAVE_WRITEV.
dnl
AC_DEFUN([GLIBCXX_CHECK_WRITEV], [

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"

  AC_MSG_CHECKING([for writev])
  AC_CACHE_VAL(glibcxx_cv_WRITEV, [
    GCC_TRY_COMPILE_OR_LINK(
      [#include <sys/uio.h>],
      [struct iovec iov[2];
       writev(0, iov, 0);],
      [glibcxx_cv_WRITEV=yes],
      [glibcxx_cv_WRITEV=no])
  ])
  if test $glibcxx_cv_WRITEV = yes; then
    AC_DEFINE(HAVE_WRITEV, 1, [Define if writev is available in <sys/uio.h>.])
  fi
  AC_MSG_RESULT($glibcxx_cv_WRITEV)

  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])


dnl
dnl Check whether int64_t is available in <stdint.h>, and define HAVE_INT64_T.
dnl Also check whether int64_t is actually a typedef to long or long long.
dnl
AC_DEFUN([GLIBCXX_CHECK_INT64_T], [

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS

  AC_MSG_CHECKING([for 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 $glibcxx_cv_INT64_T = yes; then
    AC_DEFINE(HAVE_INT64_T, 1, [Define if int64_t is available in <stdint.h>.])
    AC_MSG_RESULT($glibcxx_cv_INT64_T)

    AC_MSG_CHECKING([for int64_t as long])
    AC_CACHE_VAL(glibcxx_cv_int64_t_long, [
      AC_TRY_COMPILE(
        [#include <stdint.h>
        template<typename, typename> struct same { enum { value = -1 }; };
        template<typename Tp> struct same<Tp, Tp> { enum { value = 1 }; };
        int array[same<int64_t, long>::value];], [],
	[glibcxx_cv_int64_t_long=yes], [glibcxx_cv_int64_t_long=no])
    ])

    if test $glibcxx_cv_int64_t_long = yes; then
      AC_DEFINE(HAVE_INT64_T_LONG, 1, [Define if int64_t is a long.])
      AC_MSG_RESULT($glibcxx_cv_int64_t_long)
    fi

    AC_MSG_CHECKING([for int64_t as long long])
    AC_CACHE_VAL(glibcxx_cv_int64_t_long_long, [
      AC_TRY_COMPILE(
        [#include <stdint.h>
        template<typename, typename> struct same { enum { value = -1 }; };
        template<typename Tp> struct same<Tp, Tp> { enum { value = 1 }; };
        int array[same<int64_t, long long>::value];], [],
	[glibcxx_cv_int64_t_long_long=yes], [glibcxx_cv_int64_t_long_long=no])
    ])

    if test $glibcxx_cv_int64_t_long_long = yes; then
      AC_DEFINE(HAVE_INT64_T_LONG_LONG, 1, [Define if int64_t is a long long.])
      AC_MSG_RESULT($glibcxx_cv_int64_t_long_long)
    fi
  fi

  AC_LANG_RESTORE
])


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_MSG_CHECKING([for LFS support])
  AC_CACHE_VAL(glibcxx_cv_LFS, [
    GCC_TRY_COMPILE_OR_LINK(
      [#include <unistd.h>
       #include <stdio.h>
       #include <sys/stat.h>
      ],
      [FILE* fp;
       fopen64("t", "w");
       fseeko64(fp, 0, SEEK_CUR);
       ftello64(fp);
       lseek64(1, 0, SEEK_CUR);
       struct stat64 buf;
       fstat64(1, &buf);],
      [glibcxx_cv_LFS=yes],
      [glibcxx_cv_LFS=no])
  ])
  if test $glibcxx_cv_LFS = yes; then
    AC_DEFINE(_GLIBCXX_USE_LFS, 1, [Define if LFS support is available.])
  fi
  AC_MSG_RESULT($glibcxx_cv_LFS)
  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])


dnl
dnl Check for whether a fully dynamic basic_string implementation should
dnl be turned on, that does not put empty objects in per-process static
dnl memory (mostly useful together with shared memory allocators, see PR
dnl libstdc++/16612 for details).
dnl
dnl --enable-fully-dynamic-string defines _GLIBCXX_FULLY_DYNAMIC_STRING
dnl --disable-fully-dynamic-string leaves _GLIBCXX_FULLY_DYNAMIC_STRING undefined
dnl  +  Usage:  GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING[(DEFAULT)]
dnl       Where DEFAULT is either `yes' or `no'.
dnl
AC_DEFUN([GLIBCXX_ENABLE_FULLY_DYNAMIC_STRING], [
  GLIBCXX_ENABLE(fully-dynamic-string,$1,,[do not put empty strings in per-process static memory])
  if test $enable_fully_dynamic_string = yes; then
    AC_DEFINE(_GLIBCXX_FULLY_DYNAMIC_STRING, 1,
              [Define if a fully dynamic basic_string is wanted.])
  fi
])


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 
dnl  GLIBCXX_TEST_WCHAR_T
dnl  GLIBCXX_TEST_THREAD
dnl Substs:
dnl  baseline_dir
dnl
AC_DEFUN([GLIBCXX_CONFIGURE_TESTSUITE], [
  if $GLIBCXX_IS_NATIVE ; then
    # Do checks for resource limit functions.
    GLIBCXX_CHECK_SETRLIMIT

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

  if $GLIBCXX_IS_NATIVE && test $is_hosted = yes &&
     test $enable_symvers != no; then
    case "$host" in
      *-*-cygwin*)
        enable_abi_check=no ;;
      *)
        enable_abi_check=yes ;;
    esac
  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="$glibcxx_srcdir/config/abi/post/${abi_baseline_pair}\$(MULTISUBDIR)"
  AC_SUBST(baseline_dir)
])


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...
  # Alternatively OPTIMIZE_CXXFLAGS can be set in configure.host.
  # OPTIMIZE_CXXFLAGS = -O3 -fstrict-aliasing -fvtable-gc
  AC_SUBST(OPTIMIZE_CXXFLAGS)

  WARN_FLAGS='-Wall -Wextra -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
dnl This logic must match gcc/configure.ac's setting of gcc_gxx_include_dir.
dnl config/gxx-include-dir.m4 must be kept consistant with this as well.
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 $gxx_include_dir = no; then
    gxx_include_dir='include/c++/${gcc_version}'
    if test -n "$with_cross_host" && 
       test x"$with_cross_host" != x"no"; then	
      gxx_include_dir='${prefix}/${target_alias}/'"$gxx_include_dir"
    else
      gxx_include_dir='${prefix}/'"$gxx_include_dir"
    fi
  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])

  if test x"$enable_c99" = x"yes"; then

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS

  # Use -std=c++98 because the default (-std=gnu++98) leaves __STRICT_ANSI__
  # undefined and fake C99 facilities - like pre-standard snprintf - may be
  # spuriously enabled.
  # Long term, -std=c++0x could be even better, could manage to explicitely
  # request C99 facilities to the underlying C headers.
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -std=c++98"
  ac_save_LIBS="$LIBS"
  ac_save_gcc_no_link="$gcc_no_link"

  if test x$gcc_no_link != xyes; then
    # Use -fno-exceptions to that the C driver can link these tests without
    # hitting undefined references to personality routines.
    CXXFLAGS="$CXXFLAGS -fno-exceptions"
    AC_CHECK_LIB(m, sin, [
      LIBS="$LIBS -lm"
    ], [
      # Use the default compile-only tests in GCC_TRY_COMPILE_OR_LINK
      gcc_no_link=yes
    ])
  fi

  # Check for the existence of <math.h> functions used if C99 is enabled.
  AC_MSG_CHECKING([for ISO C99 support in <math.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_math, [
  GCC_TRY_COMPILE_OR_LINK(
     [#include <math.h>
      volatile double d1, d2;
      volatile int i;],
     [i = fpclassify(d1);
      i = isfinite(d1);
      i = isinf(d1);
      i = isnan(d1);
      i = isnormal(d1);
      i = signbit(d1);
      i = isgreater(d1, d2);
      i = isgreaterequal(d1, d2);
      i = isless(d1, d2);
      i = islessequal(d1, d2);
      i = islessgreater(d1, d2);
      i = islessgreater(d1, d2);
      i = isunordered(d1, d2);
     ],[glibcxx_cv_c99_math=yes], [glibcxx_cv_c99_math=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_math)
  if test x"$glibcxx_cv_c99_math" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_MATH, 1,
              [Define if C99 functions or macros in <math.h> should be imported
              in <cmath> in namespace std.])
  fi

  # Check for the existence of <complex.h> complex math functions.
  # This is necessary even though libstdc++ uses the builtin versions
  # of these functions, because if the builtin cannot be used, a reference
  # to the library function is emitted.
  AC_CHECK_HEADERS(tgmath.h, ac_has_tgmath_h=yes, ac_has_tgmath_h=no)
  AC_CHECK_HEADERS(complex.h, ac_has_complex_h=yes, ac_has_complex_h=no)
  glibcxx_cv_c99_complex=no;
  if test x"$ac_has_complex_h" = x"yes"; then
    AC_MSG_CHECKING([for ISO C99 support in <complex.h>])
    GCC_TRY_COMPILE_OR_LINK(
       [#include <complex.h>
	typedef __complex__ float float_type;
	typedef __complex__ double double_type;
	typedef __complex__ long double ld_type;
	volatile float_type tmpf;
	volatile double_type tmpd;
	volatile ld_type tmpld;
	volatile float f;
	volatile double d;
	volatile long double ld;],
       [f = cabsf(tmpf);
	f = cargf(tmpf);
	tmpf = ccosf(tmpf);
	tmpf = ccoshf(tmpf);
	tmpf = cexpf(tmpf);
	tmpf = clogf(tmpf);
	tmpf = csinf(tmpf);
	tmpf = csinhf(tmpf);
	tmpf = csqrtf(tmpf);
	tmpf = ctanf(tmpf);
	tmpf = ctanhf(tmpf);
	tmpf = cpowf(tmpf, tmpf);
	tmpf = cprojf(tmpf);
	d = cabs(tmpd);
	d = carg(tmpd);
	tmpd = ccos(tmpd);
	tmpd = ccosh(tmpd);
	tmpd = cexp(tmpd);
	tmpd = clog(tmpd);
	tmpd = csin(tmpd);
	tmpd = csinh(tmpd);
	tmpd = csqrt(tmpd);
	tmpd = ctan(tmpd);
	tmpd = ctanh(tmpd);
	tmpd = cpow(tmpd, tmpd);
	tmpd = cproj(tmpd);
	ld = cabsl(tmpld);
	ld = cargl(tmpld);
	tmpld = ccosl(tmpld);
	tmpld = ccoshl(tmpld);
	tmpld = cexpl(tmpld);
	tmpld = clogl(tmpld);
	tmpld = csinl(tmpld);
	tmpld = csinhl(tmpld);
	tmpld = csqrtl(tmpld);
	tmpld = ctanl(tmpld);
	tmpld = ctanhl(tmpld);
	tmpld = cpowl(tmpld, tmpld);
	tmpld = cprojl(tmpld);
       ],[glibcxx_cv_c99_complex=yes], [glibcxx_cv_c99_complex=no])
  fi
  AC_MSG_RESULT($glibcxx_cv_c99_complex)
  if test x"$glibcxx_cv_c99_complex" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_COMPLEX, 1,
              [Define if C99 functions in <complex.h> should be used in
              <complex>. Using compiler builtins for these functions requires
              corresponding C99 library functions to be present.])
  fi

  # Check for the existence in <stdio.h> of vscanf, et. al.
  AC_MSG_CHECKING([for ISO C99 support in <stdio.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_stdio, [
  GCC_TRY_COMPILE_OR_LINK(
     [#include <stdio.h>
      #include <stdarg.h>
      void foo(char* fmt, ...)
      {
	va_list args; va_start(args, fmt);
	vfscanf(stderr, "%i", args); 
	vscanf("%i", args);
	vsnprintf(fmt, 0, "%i", args);
	vsscanf(fmt, "%i", args);
      }],
     [snprintf("12", 0, "%i");],
     [glibcxx_cv_c99_stdio=yes], [glibcxx_cv_c99_stdio=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_stdio)

  # Check for the existence in <stdlib.h> of lldiv_t, et. al.
  AC_MSG_CHECKING([for ISO C99 support in <stdlib.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_stdlib, [
  GCC_TRY_COMPILE_OR_LINK(
     [#include <stdlib.h>
      volatile float f;
      volatile long double ld;
      volatile unsigned long long ll;
      lldiv_t mydivt;],
     [char* tmp;
      f = strtof("gnu", &tmp);
      ld = strtold("gnu", &tmp);
      ll = strtoll("gnu", &tmp, 10);
      ll = strtoull("gnu", &tmp, 10);
      ll = llabs(10);
      mydivt = lldiv(10,1);
      ll = mydivt.quot;
      ll = mydivt.rem;
      ll = atoll("10");
      _Exit(0);
      ],[glibcxx_cv_c99_stdlib=yes], [glibcxx_cv_c99_stdlib=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_stdlib)

  # Check for the existence in <wchar.h> of wcstold, etc.
  glibcxx_cv_c99_wchar=no;
  if test x"$ac_has_wchar_h" = xyes &&
     test x"$ac_has_wctype_h" = xyes; then
    AC_MSG_CHECKING([for ISO C99 support in <wchar.h>])	
    AC_TRY_COMPILE([#include <wchar.h>
                    namespace test
                    {
		      using ::wcstold;
		      using ::wcstoll;
		      using ::wcstoull;
		    }
		   ],[],[glibcxx_cv_c99_wchar=yes], [glibcxx_cv_c99_wchar=no])

    # Checks for wide character functions that may not be present.
    # Injection of these is wrapped with guard macros.
    # NB: only put functions here, instead of immediately above, if
    # absolutely necessary.
    AC_TRY_COMPILE([#include <wchar.h>
                    namespace test { using ::vfwscanf; } ], [],
 	    	   [AC_DEFINE(HAVE_VFWSCANF,1,
			[Defined if vfwscanf exists.])],[])

    AC_TRY_COMPILE([#include <wchar.h>
                    namespace test { using ::vswscanf; } ], [],
 	    	   [AC_DEFINE(HAVE_VSWSCANF,1,
			[Defined if vswscanf exists.])],[])

    AC_TRY_COMPILE([#include <wchar.h>
                    namespace test { using ::vwscanf; } ], [],
 	    	   [AC_DEFINE(HAVE_VWSCANF,1,[Defined if vwscanf exists.])],[])

    AC_TRY_COMPILE([#include <wchar.h>
                    namespace test { using ::wcstof; } ], [],
 	    	   [AC_DEFINE(HAVE_WCSTOF,1,[Defined if wcstof exists.])],[])

    AC_TRY_COMPILE([#include <wctype.h>],
                   [ wint_t t; int i = iswblank(t);], 
 	    	   [AC_DEFINE(HAVE_ISWBLANK,1,
			[Defined if iswblank exists.])],[])

    AC_MSG_RESULT($glibcxx_cv_c99_wchar)
  fi

  # Option parsed, now set things appropriately.
  if test x"$glibcxx_cv_c99_math" = x"no" ||
     test x"$glibcxx_cv_c99_complex" = x"no" ||
     test x"$glibcxx_cv_c99_stdio" = x"no" ||
     test x"$glibcxx_cv_c99_stdlib" = x"no" ||
     test x"$glibcxx_cv_c99_wchar" = x"no"; then
    enable_c99=no;
  else
    AC_DEFINE(_GLIBCXX_USE_C99, 1,
    [Define if C99 functions or macros from <wchar.h>, <math.h>,
    <complex.h>, <stdio.h>, and <stdlib.h> can be used or exposed.])
  fi

  gcc_no_link="$ac_save_gcc_no_link"
  LIBS="$ac_save_LIBS"
  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
  fi	

  AC_MSG_CHECKING([for fully enabled ISO C99 support])
  AC_MSG_RESULT($enable_c99)
])


dnl
dnl Check for clock_gettime clocks, used in the implementation of 20.8.5
dnl [time.clock] in the current C++0x working draft.
dnl
dnl --enable-clock-gettime
dnl --enable-clock-gettime=yes
dnl        checks for the availability of monotonic and realtime clocks
dnl        in libc and libposix4 and in case links the latter
dnl --enable-clock-gettime=rt
dnl        also searches (and, in case, links) librt.  Note that this is
dnl        not always desirable because, in glibc, for example, in turn it
dnl        triggers the linking of libpthread too, which activates locking,
dnl        a large overhead for single-thread programs.
dnl --enable-clock-gettime=no
dnl --disable-clock-gettime
dnl        disables the checks completely
dnl
AC_DEFUN([GLIBCXX_ENABLE_CLOCK_GETTIME], [

  AC_MSG_CHECKING([for clock_gettime clocks])					 
  GLIBCXX_ENABLE(clock-gettime,$1,[=KIND],
    [use KIND for check type],
    [permit yes|no|rt])

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"
  ac_save_LIBS="$LIBS"

  ac_has_clock_monotonic=no;  
  ac_has_clock_realtime=no;

  if test x"$enable_clock_gettime" != x"no"; then

    if test x"$enable_clock_gettime" = x"rt"; then
      AC_SEARCH_LIBS(clock_gettime, [rt posix4])
    else
      AC_SEARCH_LIBS(clock_gettime, [posix4])
    fi

    case "$ac_cv_search_clock_gettime" in
      -l*) GLIBCXX_LIBS=$ac_cv_search_clock_gettime
    esac

    AC_CHECK_HEADERS(unistd.h, ac_has_unistd_h=yes, ac_has_unistd_h=no)

    if test x"$ac_has_unistd_h" = x"yes"; then
      AC_MSG_CHECKING([for monotonic clock])
      AC_TRY_LINK(
        [#include <unistd.h>
         #include <time.h>
        ],
        [#if _POSIX_TIMERS > 0 && defined(_POSIX_MONOTONIC_CLOCK)
          timespec tp;     
         #endif
          clock_gettime(CLOCK_MONOTONIC, &tp);
        ], [ac_has_clock_monotonic=yes], [ac_has_clock_monotonic=no])

      AC_MSG_RESULT($ac_has_clock_monotonic)   
    
      AC_MSG_CHECKING([for realtime clock])
      AC_TRY_LINK(
        [#include <unistd.h>
         #include <time.h>
        ],
        [#if _POSIX_TIMERS > 0
          timespec tp;      
         #endif
          clock_gettime(CLOCK_REALTIME, &tp);
        ], [ac_has_clock_realtime=yes], [ac_has_clock_realtime=no])

      AC_MSG_RESULT($ac_has_clock_realtime)
    fi

  fi

  if test x"$ac_has_clock_monotonic" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_CLOCK_MONOTONIC, 1,
      [ Defined if clock_gettime has monotonic clock support. ])
  fi

  if test x"$ac_has_clock_realtime" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_CLOCK_REALTIME, 1,
      [ Defined if clock_gettime has realtime clock support. ])
  fi

  AC_SUBST(GLIBCXX_LIBS)

  CXXFLAGS="$ac_save_CXXFLAGS"
  LIBS="$ac_save_LIBS"
  AC_LANG_RESTORE
])

dnl
dnl Check for gettimeofday, used in the implementation of 20.8.5
dnl [time.clock] in the current C++0x working draft.
dnl
AC_DEFUN([GLIBCXX_CHECK_GETTIMEOFDAY], [
  
  AC_MSG_CHECKING([for gettimeofday])

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -fno-exceptions"
  
  ac_has_gettimeofday=no;
  AC_CHECK_HEADERS(sys/time.h, ac_has_sys_time_h=yes, ac_has_sys_time_h=no)
  if test x"$ac_has_sys_time_h" = x"yes"; then
    AC_MSG_CHECKING([for gettimeofday])
    GCC_TRY_COMPILE_OR_LINK([#include <sys/time.h>],
      [timeval tv; gettimeofday(&tv, 0);],
      [ac_has_gettimeofday=yes], [ac_has_gettimeofday=no])
    
    AC_MSG_RESULT($ac_has_gettimeofday)
  fi
  
  if test x"$ac_has_gettimeofday" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_GETTIMEOFDAY, 1,
      [ Defined if gettimeofday is available. ])
  fi
  
  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])

dnl
dnl Check for ISO/IEC 9899:1999 "C99" support to ISO/IEC DTR 19768 "TR1"
dnl facilities in Chapter 8, "C compatibility".
dnl
AC_DEFUN([GLIBCXX_CHECK_C99_TR1], [

  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS

  # Use -std=c++98 because the default (-std=gnu++98) leaves __STRICT_ANSI__
  # undefined and fake C99 facilities may be spuriously enabled.
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS="$CXXFLAGS -std=c++98"

  # Check for the existence of <complex.h> complex math functions used
  # by tr1/complex.
  AC_CHECK_HEADERS(complex.h, ac_has_complex_h=yes, ac_has_complex_h=no)
  ac_c99_complex_tr1=no;
  if test x"$ac_has_complex_h" = x"yes"; then
    AC_MSG_CHECKING([for ISO C99 support to TR1 in <complex.h>])
    AC_TRY_COMPILE([#include <complex.h>],
	           [typedef __complex__ float float_type; float_type tmpf;
	            cacosf(tmpf);
	            casinf(tmpf);
	            catanf(tmpf);
	            cacoshf(tmpf);
	            casinhf(tmpf);
	            catanhf(tmpf);
		    typedef __complex__ double double_type; double_type tmpd;
	            cacos(tmpd);
	            casin(tmpd);
	            catan(tmpd);
	            cacosh(tmpd);
	            casinh(tmpd);
	            catanh(tmpd);
		    typedef __complex__ long double ld_type; ld_type tmpld;
	            cacosl(tmpld);
	            casinl(tmpld);
	            catanl(tmpld);
	            cacoshl(tmpld);
	            casinhl(tmpld);
	            catanhl(tmpld);
		   ],[ac_c99_complex_tr1=yes], [ac_c99_complex_tr1=no])
  fi
  AC_MSG_RESULT($ac_c99_complex_tr1)
  if test x"$ac_c99_complex_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_COMPLEX_TR1, 1,
              [Define if C99 functions in <complex.h> should be used in
              <tr1/complex>. Using compiler builtins for these functions
	      requires corresponding C99 library functions to be present.])
  fi

  # Check for the existence of <ctype.h> functions.
  AC_MSG_CHECKING([for ISO C99 support to TR1 in <ctype.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_ctype_tr1, [
  AC_TRY_COMPILE([#include <ctype.h>],
	         [int ch;
	          int ret;
	          ret = isblank(ch);
		 ],[glibcxx_cv_c99_ctype_tr1=yes],
		   [glibcxx_cv_c99_ctype_tr1=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_ctype_tr1)
  if test x"$glibcxx_cv_c99_ctype_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_CTYPE_TR1, 1,
              [Define if C99 functions in <ctype.h> should be imported in
	      <tr1/cctype> in namespace std::tr1.])
  fi

  # Check for the existence of <fenv.h> functions.
  AC_CHECK_HEADERS(fenv.h, ac_has_fenv_h=yes, ac_has_fenv_h=no)
  ac_c99_fenv_tr1=no;
  if test x"$ac_has_fenv_h" = x"yes"; then
    AC_MSG_CHECKING([for ISO C99 support to TR1 in <fenv.h>])
    AC_TRY_COMPILE([#include <fenv.h>],
	           [int except, mode;
	            fexcept_t* pflag;
                    fenv_t* penv;
	            int ret;
	            ret = feclearexcept(except);
	            ret = fegetexceptflag(pflag, except);
	            ret = feraiseexcept(except);
	            ret = fesetexceptflag(pflag, except);
	            ret = fetestexcept(except);
	            ret = fegetround();
	            ret = fesetround(mode);
	            ret = fegetenv(penv);
	            ret = feholdexcept(penv);
	            ret = fesetenv(penv);
	            ret = feupdateenv(penv);
		   ],[ac_c99_fenv_tr1=yes], [ac_c99_fenv_tr1=no])
  fi
  AC_MSG_RESULT($ac_c99_fenv_tr1)
  if test x"$ac_c99_fenv_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_FENV_TR1, 1,
              [Define if C99 functions in <fenv.h> should be imported in
	      <tr1/cfenv> in namespace std::tr1.])
  fi

  # Check for the existence of <stdint.h> types.
  AC_MSG_CHECKING([for ISO C99 support to TR1 in <stdint.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_stdint_tr1, [
  AC_TRY_COMPILE([#define __STDC_LIMIT_MACROS
                  #define __STDC_CONSTANT_MACROS
                  #include <stdint.h>],
	         [typedef int8_t          my_int8_t;
		  my_int8_t               i8 = INT8_MIN;
		  i8 = INT8_MAX;
	          typedef int16_t         my_int16_t;
		  my_int16_t              i16 = INT16_MIN;
		  i16 = INT16_MAX;
	          typedef int32_t         my_int32_t;
		  my_int32_t              i32 = INT32_MIN;
		  i32 = INT32_MAX;
	          typedef int64_t         my_int64_t;
		  my_int64_t              i64 = INT64_MIN;
		  i64 = INT64_MAX;
	          typedef int_fast8_t     my_int_fast8_t;
		  my_int_fast8_t          if8 = INT_FAST8_MIN;
		  if8 = INT_FAST8_MAX;
	          typedef int_fast16_t    my_int_fast16_t;
		  my_int_fast16_t         if16 = INT_FAST16_MIN;
		  if16 = INT_FAST16_MAX;
	          typedef int_fast32_t    my_int_fast32_t;
		  my_int_fast32_t         if32 = INT_FAST32_MIN;
		  if32 = INT_FAST32_MAX;
	          typedef int_fast64_t    my_int_fast64_t;
		  my_int_fast64_t         if64 = INT_FAST64_MIN;
		  if64 = INT_FAST64_MAX;
	          typedef int_least8_t    my_int_least8_t;
		  my_int_least8_t         il8 = INT_LEAST8_MIN;
		  il8 = INT_LEAST8_MAX;
	          typedef int_least16_t   my_int_least16_t;
		  my_int_least16_t        il16 = INT_LEAST16_MIN;
		  il16 = INT_LEAST16_MAX;
	          typedef int_least32_t   my_int_least32_t;
		  my_int_least32_t        il32 = INT_LEAST32_MIN;
		  il32 = INT_LEAST32_MAX;
	          typedef int_least64_t   my_int_least64_t;
		  my_int_least64_t        il64 = INT_LEAST64_MIN;
		  il64 = INT_LEAST64_MAX;
		  typedef intmax_t        my_intmax_t;
		  my_intmax_t             im = INTMAX_MAX;
		  im = INTMAX_MIN;
		  typedef intptr_t        my_intptr_t;
		  my_intptr_t             ip = INTPTR_MAX;
		  ip = INTPTR_MIN;
	          typedef uint8_t         my_uint8_t;
		  my_uint8_t              ui8 = UINT8_MAX;
		  ui8 = UINT8_MAX;
	          typedef uint16_t        my_uint16_t;
		  my_uint16_t             ui16 = UINT16_MAX;
		  ui16 = UINT16_MAX;
	          typedef uint32_t        my_uint32_t;
		  my_uint32_t             ui32 = UINT32_MAX;
		  ui32 = UINT32_MAX;
	          typedef uint64_t        my_uint64_t;
		  my_uint64_t             ui64 = UINT64_MAX;
		  ui64 = UINT64_MAX;
	          typedef uint_fast8_t    my_uint_fast8_t;
		  my_uint_fast8_t         uif8 = UINT_FAST8_MAX;
		  uif8 = UINT_FAST8_MAX;
	          typedef uint_fast16_t   my_uint_fast16_t;
		  my_uint_fast16_t        uif16 = UINT_FAST16_MAX;
		  uif16 = UINT_FAST16_MAX;
	          typedef uint_fast32_t   my_uint_fast32_t;
		  my_uint_fast32_t        uif32 = UINT_FAST32_MAX;
		  uif32 = UINT_FAST32_MAX;
	          typedef uint_fast64_t   my_uint_fast64_t;
		  my_uint_fast64_t        uif64 = UINT_FAST64_MAX;
		  uif64 = UINT_FAST64_MAX;
	          typedef uint_least8_t   my_uint_least8_t;
		  my_uint_least8_t        uil8 = UINT_LEAST8_MAX;
		  uil8 = UINT_LEAST8_MAX;
	          typedef uint_least16_t  my_uint_least16_t;
		  my_uint_least16_t       uil16 = UINT_LEAST16_MAX;
		  uil16 = UINT_LEAST16_MAX;
	          typedef uint_least32_t  my_uint_least32_t;
		  my_uint_least32_t       uil32 = UINT_LEAST32_MAX;
		  uil32 = UINT_LEAST32_MAX;
	          typedef uint_least64_t  my_uint_least64_t;
		  my_uint_least64_t       uil64 = UINT_LEAST64_MAX;
		  uil64 = UINT_LEAST64_MAX;
		  typedef uintmax_t       my_uintmax_t;
		  my_uintmax_t            uim = UINTMAX_MAX;
		  uim = UINTMAX_MAX;
		  typedef uintptr_t       my_uintptr_t;
		  my_uintptr_t            uip = UINTPTR_MAX;
		  uip = UINTPTR_MAX;
		 ],[glibcxx_cv_c99_stdint_tr1=yes],
		   [glibcxx_cv_c99_stdint_tr1=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_stdint_tr1)
  if test x"$glibcxx_cv_c99_stdint_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_STDINT_TR1, 1,
              [Define if C99 types in <stdint.h> should be imported in
	      <tr1/cstdint> in namespace std::tr1.])
  fi

  # Check for the existence of <math.h> functions.
  AC_MSG_CHECKING([for ISO C99 support to TR1 in <math.h>])
  AC_CACHE_VAL(glibcxx_cv_c99_math_tr1, [
  AC_TRY_COMPILE([#include <math.h>],
	         [typedef double_t  my_double_t;
	          typedef float_t   my_float_t;
	          acosh(0.0);
	          acoshf(0.0f);
	          acoshl(0.0l);
	          asinh(0.0);
	          asinhf(0.0f);
	          asinhl(0.0l);
	          atanh(0.0);
	          atanhf(0.0f);
	          atanhl(0.0l);
	          cbrt(0.0);
	          cbrtf(0.0f);
	          cbrtl(0.0l);
	          copysign(0.0, 0.0);
	          copysignf(0.0f, 0.0f);
	          copysignl(0.0l, 0.0l);
	          erf(0.0);
	          erff(0.0f);
	          erfl(0.0l);
	          erfc(0.0);
	          erfcf(0.0f);
	          erfcl(0.0l);
	          exp2(0.0);
	          exp2f(0.0f);
	          exp2l(0.0l);
	          expm1(0.0);
	          expm1f(0.0f);
	          expm1l(0.0l);
	          fdim(0.0, 0.0);
	          fdimf(0.0f, 0.0f);
	          fdiml(0.0l, 0.0l);
	          fma(0.0, 0.0, 0.0);
	          fmaf(0.0f, 0.0f, 0.0f);
	          fmal(0.0l, 0.0l, 0.0l);
	          fmax(0.0, 0.0);
	          fmaxf(0.0f, 0.0f);
	          fmaxl(0.0l, 0.0l);
	          fmin(0.0, 0.0);
	          fminf(0.0f, 0.0f);
	          fminl(0.0l, 0.0l);
	          hypot(0.0, 0.0);
	          hypotf(0.0f, 0.0f);
	          hypotl(0.0l, 0.0l);
	          ilogb(0.0);
	          ilogbf(0.0f);
	          ilogbl(0.0l);
	          lgamma(0.0);
	          lgammaf(0.0f);
	          lgammal(0.0l);
	          llrint(0.0);
	          llrintf(0.0f);
	          llrintl(0.0l);
	          llround(0.0);
	          llroundf(0.0f);
	          llroundl(0.0l);
	          log1p(0.0);
	          log1pf(0.0f);
	          log1pl(0.0l);
	          log2(0.0);
	          log2f(0.0f);
	          log2l(0.0l);
	          logb(0.0);
	          logbf(0.0f);
	          logbl(0.0l);
	          lrint(0.0);
	          lrintf(0.0f);
	          lrintl(0.0l);
	          lround(0.0);
	          lroundf(0.0f);
	          lroundl(0.0l);
	          nan(0);
	          nanf(0);
	          nanl(0);
	          nearbyint(0.0);
	          nearbyintf(0.0f);
	          nearbyintl(0.0l);
	          nextafter(0.0, 0.0);
	          nextafterf(0.0f, 0.0f);
	          nextafterl(0.0l, 0.0l);
	          nexttoward(0.0, 0.0);
	          nexttowardf(0.0f, 0.0f);
	          nexttowardl(0.0l, 0.0l);
	          remainder(0.0, 0.0);
	          remainderf(0.0f, 0.0f);
	          remainderl(0.0l, 0.0l);
	          remquo(0.0, 0.0, 0);
	          remquo(0.0f, 0.0f, 0);
	          remquo(0.0l, 0.0l, 0);
	          rint(0.0);
	          rintf(0.0f);
	          rintl(0.0l);
	          round(0.0);
	          roundf(0.0f);
	          roundl(0.0l);
	          scalbln(0.0, 0l);
	          scalblnf(0.0f, 0l);
	          scalblnl(0.0l, 0l);
	          scalbn(0.0, 0);
	          scalbnf(0.0f, 0);
	          scalbnl(0.0l, 0);
	          tgamma(0.0);
	          tgammaf(0.0f);
	          tgammal(0.0l);
	          trunc(0.0);
	          truncf(0.0f);
	          truncl(0.0l);
		 ],[glibcxx_cv_c99_math_tr1=yes], [glibcxx_cv_c99_math_tr1=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_c99_math_tr1)
  if test x"$glibcxx_cv_c99_math_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_MATH_TR1, 1,
              [Define if C99 functions or macros in <math.h> should be imported
              in <tr1/cmath> in namespace std::tr1.])
  fi

  # Check for the existence of <inttypes.h> functions (NB: doesn't make
  # sense if the previous check fails, per C99, 7.8/1).
  ac_c99_inttypes_tr1=no;
  if test x"$glibcxx_cv_c99_stdint_tr1" = x"yes"; then
    AC_MSG_CHECKING([for ISO C99 support to TR1 in <inttypes.h>])
    AC_TRY_COMPILE([#include <inttypes.h>],
	           [intmax_t i, numer, denom, base;
	            const char* s;
	            char** endptr;
	            intmax_t ret = imaxabs(i);
	            imaxdiv_t dret = imaxdiv(numer, denom);
	            ret = strtoimax(s, endptr, base);
	            uintmax_t uret = strtoumax(s, endptr, base);
        	   ],[ac_c99_inttypes_tr1=yes], [ac_c99_inttypes_tr1=no])
  fi
  AC_MSG_RESULT($ac_c99_inttypes_tr1)
  if test x"$ac_c99_inttypes_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_C99_INTTYPES_TR1, 1,
              [Define if C99 functions in <inttypes.h> should be imported in
              <tr1/cinttypes> in namespace std::tr1.])
  fi

  # Check for the existence of the <stdbool.h> header.	
  AC_CHECK_HEADERS(stdbool.h)

  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
])

dnl
dnl Check whether "/dev/random" and "/dev/urandom" are available for the
dnl random_device of "TR1" (Chapter 5.1, "Random number generation").
dnl
AC_DEFUN([GLIBCXX_CHECK_RANDOM_TR1], [

  AC_MSG_CHECKING([for "/dev/random" and "/dev/urandom" for TR1 random_device])
  AC_CACHE_VAL(glibcxx_cv_random_tr1, [
    if test -r /dev/random && test -r /dev/urandom; then
      glibcxx_cv_random_tr1=yes;
    else
      glibcxx_cv_random_tr1=no;
    fi
  ])
  AC_MSG_RESULT($glibcxx_cv_random_tr1)

  if test x"$glibcxx_cv_random_tr1" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_RANDOM_TR1, 1,
              [Define if /dev/random and /dev/urandom are available for
	       the random_device of TR1 (Chapter 5.1).])
  fi

])

dnl
dnl Check whether EOF, SEEK_CUR, and SEEK_END have the most common values:
dnl in that case including <cstdio> in some C++ headers can be avoided.
dnl
AC_DEFUN([GLIBCXX_CHECK_STDIO_MACROS], [

  AC_MSG_CHECKING([for EOF == -1, SEEK_CUR == 1, SEEK_END == 2])
  AC_CACHE_VAL(glibcxx_cv_stdio_macros, [
  AC_TRY_COMPILE([#include <stdio.h>],
                 [#if ((EOF != -1) || (SEEK_CUR != 1) || (SEEK_END != 2))
	            unusual values...
	          #endif
	         ], [glibcxx_cv_stdio_macros=yes],
		    [glibcxx_cv_stdio_macros=no])
  ])
  AC_MSG_RESULT($glibcxx_cv_stdio_macros)
  if test x"$glibcxx_cv_stdio_macros" = x"yes"; then
    AC_DEFINE(_GLIBCXX_STDIO_MACROS, 1,
              [Define if EOF == -1, SEEK_CUR == 1, SEEK_END == 2.])
  fi

])

dnl
dnl Check whether macros, etc are present for <system_error>
dnl
AC_DEFUN([GLIBCXX_CHECK_SYSTEM_ERROR], [

m4_pushdef([n_syserr], [1])dnl
m4_foreach([syserr], [EOWNERDEAD, ENOTRECOVERABLE, ENOLINK, EPROTO, ENODATA,
		      ENOSR, ENOSTR, ETIME, EBADMSG, ECANCELED,
		      EOVERFLOW, ENOTSUP, EIDRM, ETXTBSY],
[m4_pushdef([SYSERR], m4_toupper(syserr))dnl
AC_MSG_CHECKING([for syserr])
AC_CACHE_VAL([glibcxx_cv_system_error[]n_syserr], [
AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <errno.h>]],
				   [int i = syserr;])],
		  [glibcxx_cv_system_error[]n_syserr=yes],
		  [glibcxx_cv_system_error[]n_syserr=no])
])
AC_MSG_RESULT([$glibcxx_cv_system_error[]n_syserr])
if test x"$glibcxx_cv_system_error[]n_syserr" = x"yes"; then
  AC_DEFINE([HAVE_]SYSERR, 1, [Define if ]syserr[ exists.])
fi
m4_define([n_syserr], m4_incr(n_syserr))dnl
m4_popdef([SYSERR])dnl
])
m4_popdef([n_syserr])dnl
])

dnl
dnl Check whether C++200x's standard layout types are supported. 
dnl
AC_DEFUN([GLIBCXX_CHECK_STANDARD_LAYOUT], [

  AC_MSG_CHECKING([for ISO C++200x standard layout type support])
  AC_CACHE_VAL(ac_standard_layout, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_test_CXXFLAGS="${CXXFLAGS+set}"
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS='-std=gnu++0x'

  AC_TRY_COMPILE([struct b
                  {
  		    bool t;

		    // Need standard layout relaxation from POD
		    private:	    
  		    b& operator=(const b&);
  		    b(const b&);
		    };

		    int main()
		    {
		      b tst1 = { false };
		       return 0;
		    }],,
             [ac_standard_layout=yes], [ac_standard_layout=no])

  CXXFLAGS="$ac_save_CXXFLAGS"
  AC_LANG_RESTORE
  ])
  AC_MSG_RESULT($ac_standard_layout)
  if test x"$ac_standard_layout" = x"yes"; then
    AC_DEFINE(_GLIBCXX_USE_STANDARD_LAYOUT, 1,
              [Define if standard layout types are supported in C++200x.])
  fi
])

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' or 'c_global'.
dnl
AC_DEFUN([GLIBCXX_ENABLE_CHEADERS], [
  GLIBCXX_ENABLE(cheaders,$1,[=KIND],
    [construct "C" headers for g++], [permit c|c_std|c_global])
  AC_MSG_NOTICE("C" header strategy set to $enable_cheaders)

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

  # Allow overrides to configure.host here.
  if test $enable_cheaders = c_global; then
     c_compatibility=yes
  fi

  if test $enable_cheaders = c_global || test $enable_cheaders = c_std; then
     c_extra=yes
  fi

  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_C_GLOBAL, test $enable_cheaders = c_global)
  GLIBCXX_CONDITIONAL(GLIBCXX_C_HEADERS_COMPATIBILITY, test $c_compatibility = yes)
  GLIBCXX_CONDITIONAL(GLIBCXX_C_HEADERS_EXTRA, test $c_extra = 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], [
  GLIBCXX_ENABLE(clocale,auto,[@<:@=MODEL@:>@],
    [use MODEL for target locale package],
    [permit generic|gnu|ieee_1003.1-2001|yes|no|auto])

  # Deal with gettext issues.  Default to not using it (=no) until we detect
  # support for it later.  Let the user turn it off via --e/d, but let that
  # default to on for easier handling.
  USE_NLS=no
  AC_ARG_ENABLE(nls,
    AC_HELP_STRING([--enable-nls],[use Native Language Support (default)]),
    [],
    [enable_nls=yes])
  
  # Either a known packaage, or "auto"
  if test $enable_clocale = no || test $enable_clocale = yes; then
     enable_clocale=auto
  fi
  enable_clocale_flag=$enable_clocale

  # Probe for locale model to use if none specified.
  # Default to "generic".
  if test $enable_clocale_flag = auto; then
    case ${target_os} in
      linux* | gnu* | kfreebsd*-gnu | knetbsd*-gnu)
        enable_clocale_flag=gnu	
        ;;
      darwin* | freebsd*)
        enable_clocale_flag=darwin
	;;
      *)
        enable_clocale_flag=generic
        ;;
    esac
  fi

  # Sanity check model, and test for special functionality.
  if test $enable_clocale_flag = gnu; then
    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)

    if test $enable_clocale = auto; then
      # Test for bugs early in glibc-2.2.x series
      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()
      {