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

dnl
dnl Initialize configure bits.
dnl
dnl GLIBCPP_CONFIGURE
AC_DEFUN(GLIBCPP_CONFIGURE, [
  dnl Default to --enable-multilib
  AC_ARG_ENABLE(multilib,
  [  --enable-multilib       build hella library versions (default)],
  [case "${enableval}" in
    yes) multilib=yes ;;
    no)  multilib=no ;;
    *)   AC_MSG_ERROR(bad value ${enableval} for multilib option) ;;
   esac], [multilib=yes])dnl

  # When building with srcdir == objdir, links to the source files will
  # be created in directories within the target_subdir.  We have to
  # adjust toplevel_srcdir accordingly, so that configure finds
  # install-sh and other auxiliary files that live in the top-level
  # source directory.
  if test "${srcdir}" = "."; then
    if test -z "${with_target_subdir}"; then
      toprel=".."
    else
      if test "${with_target_subdir}" != "."; then
        toprel="${with_multisrctop}../.."
      else
        toprel="${with_multisrctop}.."
      fi
    fi
  else
    toprel=".."
  fi
  AC_CONFIG_AUX_DIR(${srcdir}/$toprel)
  toplevel_srcdir=\${top_srcdir}/$toprel
  AC_SUBST(toplevel_srcdir)

  # Export build and source directories.
  # 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.
  glibcpp_builddir=`pwd`
  case $srcdir in
  [\\/$]* | ?:[\\/]*) glibcpp_srcdir=${srcdir} ;;
  *) glibcpp_srcdir=`cd "$srcdir" && ${PWDCMD-pwd} || echo "$srcdir"` ;;
  esac
  AC_SUBST(glibcpp_builddir)
  AC_SUBST(glibcpp_srcdir)

  dnl This is here just to satisfy automake.
  ifelse(not,equal,[AC_CONFIG_AUX_DIR(..)])

  AC_PROG_AWK
  # Will set LN_S to either 'ln -s' or 'ln'.  With autoconf 2.5x, can also
  # be 'cp -p' if linking isn't available.
  #ac_cv_prog_LN_S='cp -p'
  AC_PROG_LN_S

  # We use these options to decide which functions to include.
  AC_ARG_WITH(target-subdir,
  [  --with-target-subdir=SUBDIR
                          configuring in a subdirectory])
  AC_ARG_WITH(cross-host,
  [  --with-cross-host=HOST  configuring with a cross compiler])

  glibcpp_basedir=$srcdir/$toprel/$1/libstdc++-v3
  AC_SUBST(glibcpp_basedir)

  # Never versions of autoconf add an underscore to these functions.
  # Prevent future problems ...
  ifdef([AC_PROG_CC_G],[],[define([AC_PROG_CC_G],defn([_AC_PROG_CC_G]))])
  ifdef([AC_PROG_CC_GNU],[],[define([AC_PROG_CC_GNU],defn([_AC_PROG_CC_GNU]))])
  ifdef([AC_PROG_CXX_G],[],[define([AC_PROG_CXX_G],defn([_AC_PROG_CXX_G]))])
  ifdef([AC_PROG_CXX_GNU],[],[define([AC_PROG_CXX_GNU],defn([_AC_PROG_CXX_GNU]))])

  # AC_PROG_CC
  # FIXME: We temporarily define our own version of AC_PROG_CC.  This is
  # copied from autoconf 2.12, but does not call AC_PROG_CC_WORKS.  We
  # are probably using a cross compiler, which will not be able to fully
  # link an executable.  This is addressed in later versions of autoconf.

  AC_DEFUN(LIB_AC_PROG_CC,
  [AC_BEFORE([$0], [AC_PROG_CPP])dnl
  dnl Fool anybody using AC_PROG_CC.
  AC_PROVIDE([AC_PROG_CC])
  AC_CHECK_PROG(CC, gcc, gcc)
  if test -z "$CC"; then
    AC_CHECK_PROG(CC, cc, cc, , , /usr/ucb/cc)
    test -z "$CC" && AC_MSG_ERROR([no acceptable cc found in \$PATH])
  fi

  AC_PROG_CC_GNU

  if test $ac_cv_prog_gcc = yes; then
    GCC=yes
  dnl Check whether -g works, even if CFLAGS is set, in case the package
  dnl plays around with CFLAGS (such as to build both debugging and
  dnl normal versions of a library), tasteless as that idea is.
    ac_test_CFLAGS="${CFLAGS+set}"
    ac_save_CFLAGS="$CFLAGS"
    CFLAGS=
    AC_PROG_CC_G
    if test "$ac_test_CFLAGS" = set; then
      CFLAGS="$ac_save_CFLAGS"
    elif test $ac_cv_prog_cc_g = yes; then
      CFLAGS="-g -O2"
    else
      CFLAGS="-O2"
    fi
  else
    GCC=
    test "${CFLAGS+set}" = set || CFLAGS="-g"
  fi
  ])

  LIB_AC_PROG_CC

  # Likewise for AC_PROG_CXX.  We can't just call it directly because g++
  # will try to link in libstdc++.
  AC_DEFUN(LIB_AC_PROG_CXX,
  [AC_BEFORE([$0], [AC_PROG_CXXCPP])dnl
  dnl Fool anybody using AC_PROG_CXX.
  AC_PROVIDE([AC_PROG_CXX])
  # Use glibcpp_CXX so that we do not cause CXX to be cached with the
  # flags that come in CXX while configuring libstdc++.  They're different
  # from those used for all other target libraries.  If CXX is set in
  # the environment, respect that here.
  glibcpp_CXX=$CXX
  AC_CHECK_PROGS(glibcpp_CXX, $CCC c++ g++ gcc CC cxx cc++, gcc)
  AC_SUBST(glibcpp_CXX)
  CXX=$glibcpp_CXX
  test -z "$glibcpp_CXX" && AC_MSG_ERROR([no acceptable c++ found in \$PATH])

  AC_PROG_CXX_GNU

  if test $ac_cv_prog_gxx = yes; then
    GXX=yes
    dnl Check whether -g works, even if CXXFLAGS is set, in case the package
    dnl plays around with CXXFLAGS (such as to build both debugging and
    dnl normal versions of a library), tasteless as that idea is.
    ac_test_CXXFLAGS="${CXXFLAGS+set}"
    ac_save_CXXFLAGS="$CXXFLAGS"
    CXXFLAGS=
    AC_PROG_CXX_G
    if test "$ac_test_CXXFLAGS" = set; then
      CXXFLAGS="$ac_save_CXXFLAGS"
    elif test $ac_cv_prog_cxx_g = yes; then
      CXXFLAGS="-g -O2"
    else
      CXXFLAGS="-O2"
    fi
  else
    GXX=
    test "${CXXFLAGS+set}" = set || CXXFLAGS="-g"
  fi
  ])

  LIB_AC_PROG_CXX

  # For some reason, gettext needs this.
  AC_ISC_POSIX

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

  AM_MAINTAINER_MODE

  # We need AC_EXEEXT to keep automake happy in cygnus mode.  However,
  # at least currently, we never actually build a program, so we never
  # need to use $(EXEEXT).  Moreover, the test for EXEEXT normally
  # fails, because we are probably configuring with a cross compiler
  # which can't create executables.  So we include AC_EXEEXT to keep
  # automake happy, but we don't execute it, since we don't care about
  # the result.
  if false; then
    # autoconf 2.50 runs AC_EXEEXT by default, and the macro expands
    # to nothing, so nothing would remain between `then' and `fi' if it
    # were not for the `:' below.
    :
    AC_EXEEXT
  fi

  . [$]{glibcpp_basedir}/configure.host

  case [$]{glibcpp_basedir} in
    /* | [A-Za-z]:[\\/]*) libgcj_flagbasedir=[$]{glibcpp_basedir} ;;
    *) glibcpp_flagbasedir='[$](top_builddir)/'[$]{glibcpp_basedir} ;;
  esac

  # This does for the target what configure.host does for the host.  In
  # addition to possibly modifying the same flags, it also sets up symlinks.
  GLIBCPP_CHECK_TARGET

])


dnl
dnl Check to see if g++ can compile this library, and if so, if any version-
dnl specific precautions need to be taken. 
dnl 
dnl GLIBCPP_CHECK_COMPILER_VERSION
AC_DEFUN(GLIBCPP_CHECK_COMPILER_VERSION, [
if test ! -f stamp-sanity-compiler; then
  AC_MSG_CHECKING([for g++ that will successfully compile libstdc++-v3])
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_COMPILE(, [
  #if __GNUC__ < 3
    not_ok
  #endif
  ], gpp_satisfactory=yes, AC_MSG_ERROR([please upgrade to GCC 3.0 or above]))
  AC_LANG_RESTORE
  AC_MSG_RESULT($gpp_satisfactory)
  touch stamp-sanity-compiler
fi
])


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 Define 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
dnl Define SECTION_FLAGS='-ffunction-sections -fdata-sections' if
dnl compiler supports it and the user has not requested debug mode.
dnl
dnl GLIBCPP_CHECK_COMPILER_FEATURES
AC_DEFUN(GLIBCPP_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 GLIBCPP_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"$ac_fdsections" = x"yes" &&
     test x"$enable_debug" = x"no"; 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 Define SECTION_LDFLAGS='-Wl,--gc-sections' if possible.
dnl Define OPT_LDFLAGS='-Wl,-O1' if possible.
dnl Define LD, with_gnu_ld, and (possibly) glibcpp_gnu_ld_version as
dnl side-effects of testing.
dnl
dnl GLIBCPP_CHECK_LINKER_FEATURES
AC_DEFUN(GLIBCPP_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])

  # 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([,])
  glibcpp_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"$with_gnu_ld" = x"yes" && test x"$enable_debug" = x"no"; then
    OPT_LDFLAGS="-Wl,-O1 $OPT_LDFLAGS"
  fi

  AC_SUBST(SECTION_LDFLAGS)
  AC_SUBST(OPT_LDFLAGS)
])


dnl
dnl Check to see if the (math function) argument passed is
dnl declared when using the c++ compiler
dnl ASSUMES argument is a math function with ONE parameter
dnl
dnl GLIBCPP_CHECK_MATH_DECL_1
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_1, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <math.h>
		      #ifdef HAVE_IEEEFP_H
		      #include <ieeefp.h>
		      #endif
		     ], 
                     [ $1(0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
])

dnl
dnl Check to see if the (math function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl 3) if not, see if 1) and 2) for argument prepended with '_'
dnl
dnl Define HAVE_CARGF etc if "cargf" is declared and links
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a math function with ONE parameter
dnl
dnl GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1, [
  GLIBCPP_CHECK_MATH_DECL_1($1)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_CHECK_FUNCS($1)    
  else
    GLIBCPP_CHECK_MATH_DECL_1(_$1)
    if test x$glibcpp_cv_func__$1_use = x"yes"; then
      AC_CHECK_FUNCS(_$1)    
    fi
  fi
])


dnl
dnl Like GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1, but does a bunch of
dnl of functions at once.  It's an all-or-nothing check -- either 
dnl HAVE_XYZ is defined for each of the functions, or for none of them.
dnl Doing it this way saves significant configure time.
AC_DEFUN(GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1, [
  AC_MSG_CHECKING([for $1 functions])
  AC_CACHE_VAL(glibcpp_cv_func_$2_use, [
    AC_LANG_SAVE
    AC_LANG_CPLUSPLUS
    AC_TRY_COMPILE([#include <math.h>],
                   [ `for x in $3; do echo "$x (0);"; done` ],
                   [glibcpp_cv_func_$2_use=yes],
                   [glibcpp_cv_func_$2_use=no])
    AC_LANG_RESTORE])
  AC_MSG_RESULT($glibcpp_cv_func_$2_use)
  if test x$glibcpp_cv_func_$2_use = x"yes"; then
    AC_CHECK_FUNCS($3)
  fi
])

dnl
dnl Check to see if the (math function) argument passed is
dnl declared when using the c++ compiler
dnl ASSUMES argument is a math function with TWO parameters
dnl
dnl GLIBCPP_CHECK_MATH_DECL_2
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_2, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <math.h>], 
                     [ $1(0, 0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
])

dnl
dnl Check to see if the (math function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl
dnl Define HAVE_CARGF etc if "cargf" is declared and links
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a math function with TWO parameters
dnl
dnl GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2, [
  GLIBCPP_CHECK_MATH_DECL_2($1)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_CHECK_FUNCS($1)    
  else
    GLIBCPP_CHECK_MATH_DECL_2(_$1)
    if test x$glibcpp_cv_func__$1_use = x"yes"; then
      AC_CHECK_FUNCS(_$1)    
    fi
  fi
])


dnl
dnl Check to see if the (math function) argument passed is
dnl declared when using the c++ compiler
dnl ASSUMES argument is a math function with THREE parameters
dnl
dnl GLIBCPP_CHECK_MATH_DECL_3
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_3, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <math.h>], 
                     [ $1(0, 0, 0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
])

dnl
dnl Check to see if the (math function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl
dnl Define HAVE_CARGF etc if "cargf" is declared and links
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a math function with THREE parameters
dnl
dnl GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_3
AC_DEFUN(GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_3, [
  GLIBCPP_CHECK_MATH_DECL_3($1)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_CHECK_FUNCS($1)    
  else
    GLIBCPP_CHECK_MATH_DECL_3(_$1)
    if test x$glibcpp_cv_func__$1_use = x"yes"; then
      AC_CHECK_FUNCS(_$1)    
    fi
  fi
])


dnl
dnl Check to see if the (stdlib function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a math function with TWO parameters
dnl
dnl GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_2
AC_DEFUN(GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_2, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <stdlib.h>], 
                     [ $1(0, 0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_CHECK_FUNCS($1)    
  fi
])


dnl
dnl Check to see if the (stdlib function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a function with THREE parameters
dnl
dnl GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_3
AC_DEFUN(GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_3, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <stdlib.h>], 
                     [ $1(0, 0, 0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_CHECK_FUNCS($1)    
  fi
])


dnl
dnl Because the builtins are picky picky picky about the arguments they take, 
dnl do an explict linkage tests here.
dnl Check to see if the (math function) argument passed is
dnl 1) declared when using the c++ compiler
dnl 2) has "C" linkage
dnl
dnl Define HAVE_CARGF etc if "cargf" is declared and links
dnl
dnl argument 1 is name of function to check
dnl
dnl ASSUMES argument is a math function with ONE parameter
dnl
dnl GLIBCPP_CHECK_BUILTIN_MATH_DECL_LINKAGE_1
AC_DEFUN(GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1, [
  AC_MSG_CHECKING([for $1 declaration])
  if test x${glibcpp_cv_func_$1_use+set} != xset; then
    AC_CACHE_VAL(glibcpp_cv_func_$1_use, [
      AC_LANG_SAVE
      AC_LANG_CPLUSPLUS
      AC_TRY_COMPILE([#include <math.h>], 
                     [ $1(0);], 
                     [glibcpp_cv_func_$1_use=yes], [glibcpp_cv_func_$1_use=no])
      AC_LANG_RESTORE
    ])
  fi
  AC_MSG_RESULT($glibcpp_cv_func_$1_use)
  if test x$glibcpp_cv_func_$1_use = x"yes"; then
    AC_MSG_CHECKING([for $1 linkage])
    if test x${glibcpp_cv_func_$1_link+set} != xset; then
      AC_CACHE_VAL(glibcpp_cv_func_$1_link, [
        AC_TRY_LINK([#include <math.h>], 
                    [ $1(0);], 
                    [glibcpp_cv_func_$1_link=yes], [glibcpp_cv_func_$1_link=no])
      ])
    fi
    AC_MSG_RESULT($glibcpp_cv_func_$1_link)
    if test x$glibcpp_cv_func_$1_link = x"yes"; then
      ac_tr_func=HAVE_`echo $1 | tr 'abcdefghijklmnopqrstuvwxyz' 'ABCDEFGHIJKLMNOPQRSTUVWXYZ'`
      AC_DEFINE_UNQUOTED(${ac_tr_func})
    fi
  fi
])


dnl
dnl Check to see what builtin math functions are supported
dnl
dnl check for __builtin_abs
dnl check for __builtin_fabsf
dnl check for __builtin_fabs
dnl check for __builtin_fabl
dnl check for __builtin_labs
dnl check for __builtin_sqrtf
dnl check for __builtin_sqrtl
dnl check for __builtin_sqrt
dnl check for __builtin_sinf
dnl check for __builtin_sin
dnl check for __builtin_sinl
dnl check for __builtin_cosf
dnl check for __builtin_cos
dnl check for __builtin_cosl
dnl
dnl GLIBCPP_CHECK_BUILTIN_MATH_SUPPORT
AC_DEFUN(GLIBCPP_CHECK_BUILTIN_MATH_SUPPORT, [
  dnl Test for builtin math functions.
  dnl These are made in gcc/c-common.c 
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_abs)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_fabsf)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_fabs)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_fabsl)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_labs)

  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sqrtf)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sqrt)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sqrtl)

  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sinf)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sin)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_sinl)

  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_cosf)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_cos)
  GLIBCPP_CHECK_BUILTIN_MATH_DECL_AND_LINKAGE_1(__builtin_cosl)

  dnl There is, without a doubt, a more elegant way to have these
  dnl names exported so that they won't be stripped out of acconfig.h by
  dnl autoheader. I leave this as an exercise to somebody less frustrated
  dnl than I.... please email the libstdc++ list if you can figure out a
  dnl more elegant approach (see autoconf/acgen.m4 and specifically
  dnl AC_CHECK_FUNC for things to steal.)
  dummyvar=no
  if test x$dummyvar = x"yes"; then
    AC_DEFINE(HAVE___BUILTIN_ABS)
    AC_DEFINE(HAVE___BUILTIN_LABS)
    AC_DEFINE(HAVE___BUILTIN_COS)
    AC_DEFINE(HAVE___BUILTIN_COSF)
    AC_DEFINE(HAVE___BUILTIN_COSL)
    AC_DEFINE(HAVE___BUILTIN_FABS)
    AC_DEFINE(HAVE___BUILTIN_FABSF)
    AC_DEFINE(HAVE___BUILTIN_FABSL)
    AC_DEFINE(HAVE___BUILTIN_SIN)
    AC_DEFINE(HAVE___BUILTIN_SINF)
    AC_DEFINE(HAVE___BUILTIN_SINL)
    AC_DEFINE(HAVE___BUILTIN_SQRT)
    AC_DEFINE(HAVE___BUILTIN_SQRTF)
    AC_DEFINE(HAVE___BUILTIN_SQRTL)
  fi
])


dnl
dnl Check to see what the underlying c library 
dnl These checks need to do two things: 
dnl 1) make sure the name is declared when using the c++ compiler
dnl 2) make sure the name has "C" linkage
dnl This might seem like overkill but experience has shown that it's not...
dnl
dnl Define HAVE_STRTOLD if "strtold" is declared and links
dnl Define HAVE_STRTOF if "strtof" is declared and links
dnl Define HAVE_DRAND48 if "drand48" is declared and links
dnl
dnl GLIBCPP_CHECK_STDLIB_SUPPORT
AC_DEFUN(GLIBCPP_CHECK_STDLIB_SUPPORT, [
  ac_test_CXXFLAGS="${CXXFLAGS+set}"
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS='-fno-builtins -D_GNU_SOURCE'

  GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_2(strtold)
  GLIBCPP_CHECK_STDLIB_DECL_AND_LINKAGE_2(strtof)
  AC_CHECK_FUNCS(drand48)

  CXXFLAGS="$ac_save_CXXFLAGS"
])


dnl
dnl Check to see what the underlying c library or math library is like.
dnl These checks need to do two things: 
dnl 1) make sure the name is declared when using the c++ compiler
dnl 2) make sure the name has "C" linkage
dnl This might seem like overkill but experience has shown that it's not...
dnl
dnl Define HAVE_CARGF etc if "cargf" is found.
dnl
dnl GLIBCPP_CHECK_MATH_SUPPORT
AC_DEFUN(GLIBCPP_CHECK_MATH_SUPPORT, [
  ac_test_CXXFLAGS="${CXXFLAGS+set}"
  ac_save_CXXFLAGS="$CXXFLAGS"
  CXXFLAGS='-fno-builtins -D_GNU_SOURCE'

  dnl Check libm
  AC_CHECK_LIB(m, sin, libm="-lm")
  ac_save_LIBS="$LIBS"
  LIBS="$LIBS $libm"

  dnl Check to see if certain C math functions exist.
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isinf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isnan)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(finite)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(copysign)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_3(sincos)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(fpclass)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(qfpclass)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(hypot)

  dnl Check to see if basic C math functions have float versions.
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(float trig,
                                          float_trig,
                                          acosf asinf atanf \
                                          cosf sinf tanf \
                                          coshf sinhf tanhf)
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(float round,
                                          float_round,
                                          ceilf floorf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(expf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isnanf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isinff)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(atan2f)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(fabsf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(fmodf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(frexpf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(hypotf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(ldexpf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(logf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(log10f)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(modff)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(powf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(sqrtf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_3(sincosf)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(finitef)

  dnl Check to see if basic C math functions have long double versions.
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(long double trig,
                                          long_double_trig,
                                          acosl asinl atanl \
                                          cosl sinl tanl \
                                          coshl sinhl tanhl)
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(long double round,
                                          long_double_round,
                                          ceill floorl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isnanl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(isinfl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(copysignl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(atan2l)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(expl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(fabsl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(fmodl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(frexpl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(hypotl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(ldexpl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(logl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(log10l)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(modfl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_2(powl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(sqrtl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_3(sincosl)
  GLIBCPP_CHECK_MATH_DECL_AND_LINKAGE_1(finitel)

  dnl Some runtimes have these functions with a preceding underscore. Please
  dnl keep this sync'd with the one above. And if you add any new symbol,
  dnl please add the corresponding block in the @BOTTOM@ section of acconfig.h.
  dnl Check to see if certain C math functions exist.

  dnl Check to see if basic C math functions have float versions.
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(_float trig,
                                          _float_trig,
                                          _acosf _asinf _atanf \
                                          _cosf _sinf _tanf \
                                          _coshf _sinhf _tanhf)
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(_float round,
                                          _float_round,
                                          _ceilf _floorf)

  dnl Check to see if basic C math functions have long double versions.
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(_long double trig,
                                          _long_double_trig,
                                          _acosl _asinl _atanl \
                                          _cosl _sinl _tanl \
                                          _coshl _sinhl _tanhl)
  GLIBCPP_CHECK_MATH_DECLS_AND_LINKAGES_1(_long double round,
                                          _long_double_round,
                                          _ceill _floorl)

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


dnl
dnl Check to see if there is native support for complex 
dnl
dnl Don't compile bits in math/* if native support exits.
dnl
dnl Define USE_COMPLEX_LONG_DOUBLE etc if "copysignl" is found.
dnl
dnl GLIBCPP_CHECK_COMPLEX_MATH_SUPPORT
AC_DEFUN(GLIBCPP_CHECK_COMPLEX_MATH_SUPPORT, [
  dnl Check for complex versions of math functions of platform.
  AC_CHECK_LIB(m, main)
  AC_REPLACE_MATHFUNCS(nan copysignf)

  dnl For __signbit to signbit conversions.
  AC_CHECK_FUNCS([__signbit], , [LIBMATHOBJS="$LIBMATHOBJS signbit.lo"])
  AC_CHECK_FUNCS([__signbitf], , [LIBMATHOBJS="$LIBMATHOBJS signbitf.lo"])

  dnl Compile the long double complex functions only if the function 
  dnl provides the non-complex long double functions that are needed.
  dnl Currently this includes copysignl, which should be
  dnl cached from the GLIBCPP_CHECK_MATH_SUPPORT macro, above.
  if test x$ac_cv_func_copysignl = x"yes"; then
    AC_CHECK_FUNCS([__signbitl], , [LIBMATHOBJS="$LIBMATHOBJS signbitl.lo"])
  fi

  AC_SUBST(LIBMATHOBJS)
])


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 
dnl GLIBCPP_CHECK_TARGET
AC_DEFUN(GLIBCPP_CHECK_TARGET, [
    . [$]{glibcpp_basedir}/configure.target
    AC_MSG_RESULT(CPU config directory is $cpu_include_dir)
    AC_MSG_RESULT(OS config directory is $os_include_dir)
])


dnl
dnl Check to see if this target can enable the wchar_t parts of libstdc++.
dnl If --disable-c-mbchar was given, no wchar_t stuff is enabled.  (This
dnl must have been previously checked.)
dnl
dnl Define _GLIBCPP_USE_WCHAR_T if all the bits are found 
dnl Define HAVE_MBSTATE_T if mbstate_t is not in wchar.h
dnl
dnl GLIBCPP_CHECK_WCHAR_T_SUPPORT
AC_DEFUN(GLIBCPP_CHECK_WCHAR_T_SUPPORT, [

  dnl Test wchar.h for mbstate_t, which is needed for char_traits and
  dnl 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

  dnl 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)
  
  dnl 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
      
    dnl Test wchar.h for WCHAR_MIN, WCHAR_MAX, which is needed before
    dnl 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)
    
    dnl Test wchar.h for WEOF, which is what we use to determine whether
    dnl 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)
  
    dnl 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)
  
    dnl Checks for names injected into std:: by the c_std headers.
    AC_CHECK_FUNCS(btowc wctob fgetwc fgetwc fgetws fputwc fputws fwide \
    fwprintf fwscanf swprintf swscanf vfwprintf vfwscanf vswprintf vswscanf \
    vwprintf vwscanf wprintf wscanf getwc getwchar mbsinit mbrlen mbrtowc \
    mbsrtowcs wcsrtombs putwc putwchar ungetwc wcrtomb wcstod wcstof wcstol \
    wcstoul wcscpy wcsncpy wcscat wcsncat wcscmp wcscoll wcsncmp wcsxfrm \
    wcscspn wcsspn wcstok wcsftime wcschr wcspbrk wcsrchr wcsstr,, \
    ac_wfuncs=no)

    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)
  
    dnl Use iconv for wchar_t to char conversions. As such, check for 
    dnl 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)

    dnl 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)
  
    dnl At the moment, only enable wchar_t specializations if all the
    dnl above support is present.
    AC_MSG_CHECKING([for enabled wchar_t specializations])
    if test x"$ac_isoC99_wchar_t" = xyes &&
       test x"$ac_XPG2_wchar_t" = xyes; then
      AC_DEFINE(_GLIBCPP_USE_WCHAR_T)
      AC_MSG_RESULT("yes")
    else
      AC_MSG_RESULT("no")
    fi
  else
    dnl Wide characters disabled by the user. 
    AC_MSG_WARN([wchar_t support disabled.])
  fi
])


dnl
dnl Check for special debugging mode; not for production use.
dnl
dnl GLIBCPP_ENABLE_DEBUG
dnl --enable-debug sets '-ggdb3 -O0'.
dnl --disable-debug sets '-g' and whatever optimization options the
dnl     compiler can handle.
dnl  +  --enable-maintainer-mode automatically defaults this to on.
dnl  +  Perhaps -D/-U of NDEBUG, DEBUG, DEBUG_ASSERT, ...?
dnl  +  Usage:  GLIBCPP_ENABLE_DEBUG[(DEFAULT)]
dnl       Where DEFAULT is either `yes' or `no'.  If ommitted, it
dnl       defaults to `no'.
AC_DEFUN(GLIBCPP_ENABLE_DEBUG, [dnl
define([GLIBCPP_ENABLE_DEBUG_DEFAULT], ifelse($1, yes, yes, no))dnl
AC_ARG_ENABLE(debug,
changequote(<<, >>)dnl
<<  --enable-debug          extra debugging, turn off optimization [default=>>GLIBCPP_ENABLE_DEBUG_DEFAULT],
changequote([, ])dnl
[case "${enableval}" in
 yes) enable_debug=yes ;;
 no)  enable_debug=no ;;
 *)   AC_MSG_ERROR([Unknown argument to enable/disable extra debugging]) ;;
 esac],
enable_debug=GLIBCPP_ENABLE_DEBUG_DEFAULT)dnl

dnl Option parsed, now set things appropriately
case "${enable_debug}" in
    yes) 
        DEBUG_FLAGS='-O0 -ggdb3'                        
        ;; 
    no)   
        DEBUG_FLAGS='-g'
        ;;
esac
AC_SUBST(DEBUG_FLAGS)
])


dnl
dnl Check for "unusual" flags to pass to the compiler while building.
dnl
dnl GLIBCPP_ENABLE_CXX_FLAGS
dnl --enable-cxx-flags='-foo -bar -baz' is a general method for passing
dnl     experimental flags such as -fhonor-std, -fsquangle, -Dfloat=char, etc.
dnl     Somehow this same set of flags must be passed when [re]building
dnl     libgcc.
dnl --disable-cxx-flags passes nothing.
dnl  +  See http://gcc.gnu.org/ml/libstdc++/2000-q2/msg00131.html
dnl         http://gcc.gnu.org/ml/libstdc++/2000-q2/msg00284.html
dnl         http://gcc.gnu.org/ml/libstdc++/2000-q1/msg00035.html
dnl  +  Usage:  GLIBCPP_ENABLE_CXX_FLAGS(default flags)
dnl       If "default flags" is an empty string (or "none"), the effect is
dnl       the same as --disable or --enable=no.
AC_DEFUN(GLIBCPP_ENABLE_CXX_FLAGS, [dnl
define([GLIBCPP_ENABLE_CXX_FLAGS_DEFAULT], ifelse($1,,, $1))dnl
AC_ARG_ENABLE(cxx-flags,
changequote(<<, >>)dnl
<<  --enable-cxx-flags=FLAGS      pass compiler FLAGS when building library;
                                [default=>>GLIBCPP_ENABLE_CXX_FLAGS_DEFAULT],
changequote([, ])dnl
[case "x$enableval" in
 xyes)   
        AC_MSG_ERROR([--enable-cxx-flags needs compiler flags as arguments]) ;;
 xno|x)  
        enable_cxx_flags='' ;;
 *)      
        enable_cxx_flags="$enableval" ;;
 esac],
enable_cxx_flags='GLIBCPP_ENABLE_CXX_FLAGS_DEFAULT')

dnl Thinko on my part during design.  This kludge is the workaround.
if test "$enable_cxx_flags" = "none"; then 
  enable_cxx_flags=''; 
fi

dnl Run through flags (either default or command-line) and set anything
dnl extra (e.g., #defines) that must accompany particular g++ options.
if test -n "$enable_cxx_flags"; then
    for f in $enable_cxx_flags; do
        case "$f" in
            -fhonor-std)  ;;
            -*)  ;;
            *)   # and we're trying to pass /what/ exactly?
                 AC_MSG_ERROR([compiler flags start with a -]) ;;
        esac
    done
fi
EXTRA_CXX_FLAGS="$enable_cxx_flags"
AC_SUBST(EXTRA_CXX_FLAGS)
])


dnl
dnl Check for which locale library to use:  gnu or generic.
dnl
dnl GLIBCPP_ENABLE_CLOCALE
dnl --enable-clocale=gnu sets config/locale/c_locale_gnu.cc and friends
dnl --enable-clocale=generic sets config/locale/c_locale_generic.cc and friends
dnl 
dnl default is generic
dnl
AC_DEFUN(GLIBCPP_ENABLE_CLOCALE, [
  AC_MSG_CHECKING([for clocale to use])
  AC_ARG_ENABLE(clocale,
  [  --enable-clocale        enable model for target locale package. 
  --enable-clocale=MODEL  use MODEL target-speific locale package. [default=generic]
  ], 
  if test x$enable_clocale = xno; then
     enable_clocale=no
  fi,
     enable_clocale=no)

  enable_clocale_flag=$enable_clocale

  dnl Probe for locale support if no specific model is specified.
  dnl Default to "generic"
  if test x$enable_clocale_flag = xno; then
    case x${target_os} in
      xlinux* | xgnu*)
	AC_EGREP_CPP([_GLIBCPP_ok], [
        #include <features.h>
        #if __GLIBC__ > 2 || (__GLIBC__ == 2 && __GLIBC_MINOR__ >= 2) 
          _GLIBCPP_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>
	  int main()
	  {