[bpt/guile.git] / configure.ac

dnl   configuration script for Guile
dnl   Process this file with autoconf to produce configure.
dnl

define(GUILE_CONFIGURE_COPYRIGHT,[[

Copyright (C) 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008, 2009 Free Software Foundation, Inc.

This file is part of GUILE

GUILE is free software; you can redistribute it and/or modify it under
the terms of the GNU Lesser General Public License as published by the
Free Software Foundation; either version 3, or (at your option) any
later version.

GUILE is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
License for more details.

You should have received a copy of the GNU Lesser General Public
License along with GUILE; see the file COPYING.LESSER.  If not, write
to the Free Software Foundation, Inc., 51 Franklin Street, Fifth
Floor, Boston, MA 02110-1301, USA.

]])

AC_PREREQ(2.61)

dnl  `patsubst' here deletes the newline which "echo" prints.  We can't use
dnl  "echo -n" since -n is not portable (see autoconf manual "Limitations of
dnl  Builtins"), in particular on solaris it results in a literal "-n" in
dnl  the output.
dnl
AC_INIT(patsubst(m4_esyscmd(. ./GUILE-VERSION && echo ${PACKAGE}),[
]),
        patsubst(m4_esyscmd(. ./GUILE-VERSION && echo ${GUILE_VERSION}),[
]),
        [bug-guile@gnu.org])
AC_CONFIG_AUX_DIR([build-aux])
AC_CONFIG_MACRO_DIR([m4])
AC_CONFIG_SRCDIR(GUILE-VERSION)

AM_INIT_AUTOMAKE([gnu no-define check-news -Wall -Wno-override])

AC_COPYRIGHT(GUILE_CONFIGURE_COPYRIGHT)
AC_CONFIG_SRCDIR([GUILE-VERSION])

. $srcdir/GUILE-VERSION

AC_CONFIG_HEADERS([config.h])
AH_TOP(/*GUILE_CONFIGURE_COPYRIGHT*/)

#--------------------------------------------------------------------

AC_LANG([C])

dnl Some more checks for Win32
AC_CANONICAL_HOST

AC_LIBTOOL_WIN32_DLL

AC_PROG_INSTALL
AC_PROG_CC
gl_EARLY
AC_PROG_CPP
AC_PROG_AWK

dnl Gnulib.
gl_INIT

AC_PROG_CC_C89

# for per-target cflags in the libguile subdir
AM_PROG_CC_C_O

AC_LIBTOOL_DLOPEN
AC_PROG_LIBTOOL
AC_CHECK_LIB([ltdl], [lt_dlinit], ,
  [AC_MSG_ERROR([libltdl not found.  See README.])])
AC_CHECK_HEADER([ltdl.h], [],
  [AC_MSG_ERROR([<ltdl.h> not found.  See README.])])

AC_CHECK_PROG(have_makeinfo, makeinfo, yes, no)
AM_CONDITIONAL(HAVE_MAKEINFO, test "$have_makeinfo" = yes)

AM_PATH_LISPDIR

#--------------------------------------------------------------------
#
# User options (after above tests that may set default CFLAGS etc.)
#
#--------------------------------------------------------------------

GUILE_ERROR_ON_WARNING="yes"

AC_ARG_ENABLE(error-on-warning,
  [  --enable-error-on-warning    treat compile warnings as errors],
  [case "${enableval}" in
     yes | y) GUILE_ERROR_ON_WARNING="yes" ;;
     no | n)  GUILE_ERROR_ON_WARNING="no" ;;
     *) AC_MSG_ERROR(bad value ${enableval} for --enable-error-on-warning) ;;
   esac])

SCM_I_GSC_GUILE_DEBUG_FREELIST=0
AC_ARG_ENABLE(debug-freelist,
  [  --enable-debug-freelist include garbage collector freelist debugging code],
  if test "$enable_debug_freelist" = y \
     || test "$enable_debug_freelist" = yes; then
    SCM_I_GSC_GUILE_DEBUG_FREELIST=1
  fi)

AC_ARG_ENABLE(debug-malloc,
  [  --enable-debug-malloc   include malloc debugging code],
  if test "$enable_debug_malloc" = y || test "$enable_debug_malloc" = yes; then
    AC_DEFINE(GUILE_DEBUG_MALLOC, 1,
      [Define this if you want to debug scm_must_malloc/realloc/free calls.])
  fi)

SCM_I_GSC_GUILE_DEBUG=0
AC_ARG_ENABLE(guile-debug,
  [AS_HELP_STRING([--enable-guile-debug],
                  [include internal debugging functions])],
  if test "$enable_guile_debug" = y || test "$enable_guile_debug" = yes; then
    SCM_I_GSC_GUILE_DEBUG=1
  fi)

AC_ARG_ENABLE(posix,
  [  --disable-posix         omit posix interfaces],,
  enable_posix=yes)

AC_ARG_ENABLE(networking,
  [  --disable-networking    omit networking interfaces],,
  enable_networking=yes)

AC_ARG_ENABLE(regex,
  [  --disable-regex         omit regular expression interfaces],,
  enable_regex=yes)

AC_ARG_ENABLE([discouraged],
  AS_HELP_STRING([--disable-discouraged],[omit discouraged features]))

if test "$enable_discouraged" = no; then
  SCM_I_GSC_ENABLE_DISCOURAGED=0
else
  SCM_I_GSC_ENABLE_DISCOURAGED=1
fi

AC_ARG_ENABLE([deprecated],
  AS_HELP_STRING([--disable-deprecated],[omit deprecated features]))

if test "$enable_deprecated" = no; then
  SCM_I_GSC_ENABLE_DEPRECATED=0
  warn_default=no
else
  if test "$enable_deprecated" = yes || test "$enable_deprecated" = ""; then
    warn_default=summary
  elif test "$enable_deprecated" = shutup; then
    warn_default=no
  else
    warn_default=$enable_deprecated
  fi
  SCM_I_GSC_ENABLE_DEPRECATED=1
fi
AC_DEFINE_UNQUOTED(SCM_WARN_DEPRECATED_DEFAULT, "$warn_default",
[Define this to control the default warning level for deprecated features.])

AC_ARG_ENABLE(elisp,
  [  --disable-elisp         omit Emacs Lisp support],,
  enable_elisp=yes)

dnl  Added the following configure option in January 2008 following
dnl  investigation of problems with "64" system and library calls on
dnl  Darwin (MacOS X).  The libguile code (_scm.h) assumes that if a
dnl  system has stat64, it will have all the other 64 APIs too; but on
dnl  Darwin, stat64 is there but other APIs are missing.
dnl 
dnl  It also appears, from the Darwin docs, that most system call APIs
dnl  there (i.e. the traditional ones _without_ "64" in their names) have
dnl  been 64-bit-capable for a long time now, so it isn't necessary to
dnl  use "64" versions anyway.  For example, Darwin's off_t is 64-bit.
dnl 
dnl  A similar problem has been reported for HP-UX:
dnl  http://www.nabble.com/Building-guile-1.8.2-on-hpux-td13106681.html
dnl 
dnl  Therefore, and also because a Guile without LARGEFILE64 support is
dnl  better than no Guile at all, we provide this option to suppress
dnl  trying to use "64" calls.
dnl 
dnl  It may be that for some 64-bit function on Darwin/HP-UX we do need
dnl  to use a "64" call, and hence that by using --without-64-calls we're
dnl  missing out on that.  If so, someone can work on that in the future.
dnl  For now, --without-64-calls allows Guile to build on OSs where it
dnl  wasn't building before.
AC_MSG_CHECKING([whether to use system and library "64" calls])
AC_ARG_WITH([64-calls],
  AS_HELP_STRING([--without-64-calls],
                 [don't attempt to use system and library calls with "64" in their names]),
  [use_64_calls=$withval],
  [use_64_calls=yes
   case $host in
     *-apple-darwin* )
       use_64_calls=no
       ;;
     powerpc-ibm-aix* )
       use_64_calls=no
       ;;
   esac])
AC_MSG_RESULT($use_64_calls)
case "$use_64_calls" in
  y* )
    AC_DEFINE(GUILE_USE_64_CALLS, 1,
      [Define to 1 in order to try to use "64" versions of system and library calls.])
    ;;
esac

#--------------------------------------------------------------------

dnl Check for dynamic linking

use_modules=yes
AC_ARG_WITH(modules,
[  --with-modules[=FILES]  Add support for dynamic modules],
use_modules="$withval")
test -z "$use_modules" && use_modules=yes
DLPREOPEN=
if test "$use_modules" != no; then
  if test "$use_modules" = yes; then
    DLPREOPEN="-dlpreopen force"
  else
    DLPREOPEN="-export-dynamic"
    for module in $use_modules; do
      DLPREOPEN="$DLPREOPEN -dlopen $module"
    done
  fi
fi

dnl files which are destined for separate modules.

if test "$use_modules" != no; then
   AC_LIBOBJ([dynl])
fi

if test "$enable_posix" = yes; then
   AC_LIBOBJ([filesys])
   AC_LIBOBJ([posix])
   AC_DEFINE(HAVE_POSIX, 1,
     [Define this if you want support for POSIX system calls in Guile.])
fi

if test "$enable_networking" = yes; then
   AC_LIBOBJ([net_db])
   AC_LIBOBJ([socket])
   AC_DEFINE(HAVE_NETWORKING, 1,
     [Define this if you want support for networking in Guile.])
fi

if test "$enable_debug_malloc" = yes; then
   AC_LIBOBJ([debug-malloc])
fi

if test "$enable_elisp" = yes; then
  SCM_I_GSC_ENABLE_ELISP=1
else
  SCM_I_GSC_ENABLE_ELISP=0
fi
AC_CHECK_LIB(uca, __uc_get_ar_bsp)

AC_C_CONST

# "volatile" is used in a couple of tests below.
AC_C_VOLATILE

AC_C_INLINE
if test "$ac_cv_c_inline" != no; then
  SCM_I_GSC_C_INLINE="\"${ac_cv_c_inline}\""
else
  SCM_I_GSC_C_INLINE=NULL
fi
AC_CHECK_LIB(uca, __uc_get_ar_bsp)

AC_C_BIGENDIAN

AC_C_LABELS_AS_VALUES

AC_CHECK_SIZEOF(char)
AC_CHECK_SIZEOF(unsigned char)
AC_CHECK_SIZEOF(short)
AC_CHECK_SIZEOF(unsigned short)
AC_CHECK_SIZEOF(int)
AC_CHECK_SIZEOF(unsigned int)
AC_CHECK_SIZEOF(long)
AC_CHECK_SIZEOF(unsigned long)
AC_CHECK_SIZEOF(size_t)
AC_CHECK_SIZEOF(long long)
AC_CHECK_SIZEOF(unsigned long long)
AC_CHECK_SIZEOF(__int64)
AC_CHECK_SIZEOF(unsigned __int64)
AC_CHECK_SIZEOF(void *)
AC_CHECK_SIZEOF(intptr_t)
AC_CHECK_SIZEOF(uintptr_t)
AC_CHECK_SIZEOF(ptrdiff_t)
AC_CHECK_SIZEOF(size_t)
AC_CHECK_SIZEOF(off_t)

if test "$ac_cv_sizeof_long" -ne "$ac_cv_sizeof_void_p"; then
  AC_MSG_ERROR(sizes of long and void* are not identical)
fi

if test "$ac_cv_sizeof_ptrdiff_t" -ne 0; then
  SCM_I_GSC_T_PTRDIFF='"ptrdiff_t"'
else
  SCM_I_GSC_T_PTRDIFF='"long"'
fi
AC_SUBST([SCM_I_GSC_T_PTRDIFF])

AC_CHECK_HEADERS([stdint.h])
AC_CHECK_HEADERS([inttypes.h])

AC_CHECK_SIZEOF(intmax_t)

SCM_I_GSC_NEEDS_STDINT_H=0
SCM_I_GSC_NEEDS_INTTYPES_H=0

### intptr and uintptr (try not to use inttypes if we don't have to)
if test "$ac_cv_header_inttypes_h" = yes; then
  if test "$ac_cv_sizeof_intptr_t" -eq 0; then
    AC_CHECK_SIZEOF([intptr_t],,[#include <inttypes.h>
#include <stdio.h>])
    if test "$ac_cv_sizeof_intptr_t" -ne 0; then
      SCM_I_GSC_NEEDS_INTTYPES_H=1
    fi
  fi
  if test "$ac_cv_sizeof_uintptr_t" -eq 0; then
    AC_CHECK_SIZEOF([uintptr_t],,[#include <inttypes.h>
#include <stdio.h>])
    if test "$ac_cv_sizeof_uintptr_t" -ne 0; then
      SCM_I_GSC_NEEDS_INTTYPES_H=1
    fi
  fi
fi

### See what's provided by stdint.h
if test "$ac_cv_header_stdint_h" = yes; then
   AC_CHECK_TYPE([int8_t],[scm_stdint_has_int8=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([uint8_t],[scm_stdint_has_uint8=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([int16_t],[scm_stdint_has_int16=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([uint16_t],[scm_stdint_has_uint16=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([int32_t],[scm_stdint_has_int32=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([uint32_t],[scm_stdint_has_uint32=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([int64_t],[scm_stdint_has_int64=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([uint64_t],[scm_stdint_has_uint64=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([intmax_t],[scm_stdint_has_intmax=1],,[#include <stdint.h>])
   AC_CHECK_TYPE([uintmax_t],[scm_stdint_has_uintmax=1],,[#include <stdint.h>])
fi

# so we don't get confused by the cache (wish there was a better way
# to check particular headers for the same type...)

unset ac_cv_type_int8_t
unset ac_cv_type_uint8_t
unset ac_cv_type_int16_t
unset ac_cv_type_uint16_t
unset ac_cv_type_int32_t
unset ac_cv_type_uint32_t
unset ac_cv_type_int64_t
unset ac_cv_type_uint64_t
unset ac_cv_type_intmax_t
unset ac_cv_type_uintmax_t

### See what's provided by inttypes.h
if test "$ac_cv_header_inttypes_h" = yes; then
  AC_CHECK_TYPE([int8_t],[scm_inttypes_has_int8=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([uint8_t],[scm_inttypes_has_uint8=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([int16_t],[scm_inttypes_has_int16=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([uint16_t],[scm_inttypes_has_uint16=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([int32_t],[scm_inttypes_has_int32=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([uint32_t],[scm_inttypes_has_uint32=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([int64_t],[scm_inttypes_has_int64=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([uint64_t],[scm_inttypes_has_uint64=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([intmax_t],[scm_inttypes_has_intmax=1],,[#include <inttypes.h>])
  AC_CHECK_TYPE([uintmax_t],[scm_inttypes_has_uintmax=1],,[#include <inttypes.h>])
fi

# Try hard to find definitions for some required scm_t_*int* types.

### Required type scm_t_int8
if test "$scm_stdint_has_int8"; then
  SCM_I_GSC_T_INT8='"int8_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_int8"; then
  SCM_I_GSC_T_INT8='"int8_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_char" -eq 1; then
  SCM_I_GSC_T_INT8='"signed char"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_int8.])
fi
AC_SUBST([SCM_I_GSC_T_INT8])

### Required type scm_t_uint8
if test "$scm_stdint_has_uint8"; then
  SCM_I_GSC_T_UINT8='"uint8_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_uint8"; then
  SCM_I_GSC_T_UINT8='"uint8_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_unsigned_char" -eq 1; then
  SCM_I_GSC_T_UINT8='"unsigned char"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_uint8.])
fi
AC_SUBST([SCM_I_GSC_T_UINT8])

### Required type scm_t_int16 (ANSI C says int or short might work)
if test "$scm_stdint_has_int16"; then
  SCM_I_GSC_T_INT16='"int16_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_int16"; then
  SCM_I_GSC_T_INT16='"int16_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_int" -eq 2; then
  SCM_I_GSC_T_INT16='"int"'
elif test "$ac_cv_sizeof_short" -eq 2; then
  SCM_I_GSC_T_INT16='"short"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_int16.])
fi
AC_SUBST([SCM_I_GSC_T_INT16])

### Required type scm_t_uint16 (ANSI C says int or short might work)
if test "$scm_stdint_has_uint16"; then
  SCM_I_GSC_T_UINT16='"uint16_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_uint16"; then
  SCM_I_GSC_T_UINT16='"uint16_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_unsigned_int" -eq 2; then
  SCM_I_GSC_T_UINT16='"unsigned int"'
elif test "$ac_cv_sizeof_unsigned_short" -eq 2; then
  SCM_I_GSC_T_UINT16='"unsigned short"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_uint16.])
fi
AC_SUBST([SCM_I_GSC_T_UINT16])


### Required type scm_t_int32 (ANSI C says int, short, or long might work)
if test "$scm_stdint_has_int32"; then
  SCM_I_GSC_T_INT32='"int32_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_int32"; then
  SCM_I_GSC_T_INT32='"int32_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_int" -eq 4; then
  SCM_I_GSC_T_INT32='"int"'
elif test "$ac_cv_sizeof_long" -eq 4; then
  SCM_I_GSC_T_INT32='"long"'
elif test "$ac_cv_sizeof_short" -eq 4; then
  SCM_I_GSC_T_INT32='"short"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_int32.])
fi
AC_SUBST([SCM_I_GSC_T_INT32])

### Required type scm_t_uint32 (ANSI C says int, short, or long might work)
if test "$scm_stdint_has_uint32"; then
  SCM_I_GSC_T_UINT32='"uint32_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_uint32"; then
  SCM_I_GSC_T_UINT32='"uint32_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_unsigned_int" -eq 4; then
  SCM_I_GSC_T_UINT32='"unsigned int"'
elif test "$ac_cv_sizeof_unsigned_long" -eq 4; then
  SCM_I_GSC_T_UINT32='"unsigned long"'
elif test "$ac_cv_sizeof_unsigned_short" -eq 4; then
  SCM_I_GSC_T_UINT32='"unsigned short"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_uint32.])
fi
AC_SUBST([SCM_I_GSC_T_UINT32])

### Optional type scm_t_int64 (ANSI C says int, short, or long might work)
### Also try 'long long' and '__int64' if we have it.
SCM_I_GSC_T_INT64=0
if test "$scm_stdint_has_int64"; then
  SCM_I_GSC_T_INT64='"int64_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_int64"; then
  SCM_I_GSC_T_INT64='"int64_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_int" -eq 8; then
  SCM_I_GSC_T_INT64='"int"'
elif test "$ac_cv_sizeof_long" -eq 8; then
  SCM_I_GSC_T_INT64='"long"'
elif test "$ac_cv_sizeof_short" -eq 8; then
  SCM_I_GSC_T_INT64='"short"'
elif test "$ac_cv_sizeof_long_long" -eq 8; then
  SCM_I_GSC_T_INT64='"long long"'
elif test "$ac_cv_sizeof___int64" -eq 8; then
  SCM_I_GSC_T_INT64='"__int64"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_int64.])
fi
AC_SUBST([SCM_I_GSC_T_INT64])


### Optional type scm_t_uint64 (ANSI C says int, short, or long might work)
### Also try 'long long' and '__int64' if we have it.
SCM_I_GSC_T_UINT64=0
if test "$scm_stdint_has_uint64"; then
  SCM_I_GSC_T_UINT64='"uint64_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_uint64"; then
  SCM_I_GSC_T_UINT64='"uint64_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_unsigned_int" -eq 8; then
  SCM_I_GSC_T_UINT64='"unsigned int"'
elif test "$ac_cv_sizeof_unsigned_long" -eq 8; then
  SCM_I_GSC_T_UINT64='"unsigned long"'
elif test "$ac_cv_sizeof_unsigned_short" -eq 8; then
  SCM_I_GSC_T_UINT64='"unsigned short"'
elif test "$ac_cv_sizeof_unsigned_long_long" -eq 8; then
  SCM_I_GSC_T_UINT64='"unsigned long long"'
elif test "$ac_cv_sizeof_unsigned___int64" -eq 8; then
  SCM_I_GSC_T_UINT64='"unsigned __int64"'
else
  AC_MSG_ERROR([Can't find appropriate type for scm_t_uint64.])
fi
AC_SUBST([SCM_I_GSC_T_UINT64])

### Required type scm_t_intmax
###
### We try 'intmax_t', '__int64', 'long long' in this order.  When
### none of them is available, we use 'long'.
###
SCM_I_GSC_T_INTMAX=0
if test "$scm_stdint_has_intmax"; then
  SCM_I_GSC_T_INTMAX='"intmax_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_intmax"; then
  SCM_I_GSC_T_INTMAX='"intmax_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof___int64" -ne 0; then
  SCM_I_GSC_T_INTMAX='"__int64"'
elif test "$ac_cv_sizeof_long_long" -ne 0; then
  SCM_I_GSC_T_INTMAX='"long long"'
else
  SCM_I_GSC_T_INTMAX='"long"'
fi
AC_SUBST([SCM_I_GSC_T_INTMAX])

### Required type scm_t_uintmax
###
### We try 'uintmax_t', 'unsigned __int64', 'unsigned long long' in
### this order.  When none of them is available, we use 'unsigned long'.
###
SCM_I_GSC_T_UINTMAX=0
if test "$scm_stdint_has_uintmax"; then
  SCM_I_GSC_T_UINTMAX='"uintmax_t"'
  SCM_I_GSC_NEEDS_STDINT_H=1
elif test "$scm_inttypes_has_uintmax"; then
  SCM_I_GSC_T_UINTMAX='"uintmax_t"'
  SCM_I_GSC_NEEDS_INTTYPES_H=1
elif test "$ac_cv_sizeof_unsigned___int64" -ne 0; then
  SCM_I_GSC_T_UINTMAX='"unsigned __int64"'
elif test "$ac_cv_sizeof_unsigned_long_long" -ne 0; then
  SCM_I_GSC_T_UINTMAX='"unsigned long long"'
else
  SCM_I_GSC_T_UINTMAX='"unsigned long"'
fi
AC_SUBST([SCM_I_GSC_T_UINTMAX])


AC_SUBST([SCM_I_GSC_NEEDS_STDINT_H])
AC_SUBST([SCM_I_GSC_NEEDS_INTTYPES_H])

AC_HEADER_STDC
AC_HEADER_TIME
AC_HEADER_SYS_WAIT
AC_HEADER_DIRENT

# Reason for checking:
#
#   HP-UX 11.11 (at least) doesn't provide `struct dirent64', even
#   with `_LARGEFILE64_SOURCE', so check whether it's available.
#
AC_CHECK_MEMBER([struct dirent64.d_name],
  [SCM_I_GSC_HAVE_STRUCT_DIRENT64=1], [SCM_I_GSC_HAVE_STRUCT_DIRENT64=0],
  [ #ifndef _LARGEFILE64_SOURCE
    # define _LARGEFILE64_SOURCE
    #endif

    /* Per Autoconf manual.  */
    #include <sys/types.h>
    #ifdef HAVE_DIRENT_H
    # include <dirent.h>
    #else
    # define dirent direct
    # ifdef HAVE_SYS_NDIR_H
    #  include <sys/ndir.h>
    # endif
    # ifdef HAVE_SYS_DIR_H
    #  include <sys/dir.h>
    # endif
    # ifdef HAVE_NDIR_H
    #  include <ndir.h>
    # endif
    #endif ])
AC_SUBST([SCM_I_GSC_HAVE_STRUCT_DIRENT64])

# Reasons for testing:
#   complex.h - new in C99
#   fenv.h - available in C99, but not older systems
#   machine/fpu.h - on Tru64 5.1b, the declaration of fesetround(3) is in
#     this file instead of <fenv.h>
#   process.h - mingw specific
#   langinfo.h, nl_types.h - SuS v2
#
AC_CHECK_HEADERS([complex.h fenv.h io.h libc.h limits.h malloc.h memory.h process.h string.h \
regex.h rxposix.h rx/rxposix.h sys/dir.h sys/ioctl.h sys/select.h \
sys/time.h sys/timeb.h sys/times.h sys/stdtypes.h sys/types.h \
sys/utime.h time.h unistd.h utime.h pwd.h grp.h sys/utsname.h \
direct.h langinfo.h nl_types.h machine/fpu.h])

# "complex double" is new in C99, and "complex" is only a keyword if
# <complex.h> is included
AC_CHECK_TYPES(complex double,,,
[#if HAVE_COMPLEX_H
#include <complex.h>
#endif])

# On MacOS X <sys/socklen.h> contains socklen_t, so must include that
# when testing.
AC_CHECK_TYPE(socklen_t, ,
  [AC_DEFINE_UNQUOTED(socklen_t, int,
                      [Define to `int' if <sys/socket.h> does not define.])],
  [#if HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <sys/socket.h>
])
AC_CHECK_TYPE(struct ip_mreq)

GUILE_HEADER_LIBC_WITH_UNISTD

AC_TYPE_GETGROUPS
AC_TYPE_SIGNAL
AC_TYPE_MODE_T

# On mingw -lm is empty, so this test is unnecessary, but it's
# harmless so we don't hard-code to suppress it.
#
AC_CHECK_LIB(m, cos)

AC_CHECK_FUNCS(gethostbyname)
if test $ac_cv_func_gethostbyname = no; then
    AC_CHECK_LIB(nsl, gethostbyname)
fi

AC_CHECK_FUNCS(connect)
if test $ac_cv_func_connect = no; then
    AC_CHECK_LIB(socket, connect)
fi

dnl
dnl Check for Winsock and other functionality on Win32 (*not* CygWin)
dnl
EXTRA_DEFS=""
case $host in
  *-*-mingw*)
    AC_CHECK_HEADER(winsock2.h, [AC_DEFINE([HAVE_WINSOCK2_H], 1,
      [Define if you have the <winsock2.h> header file.])])
    AC_CHECK_LIB(ws2_32, main)
    AC_LIBOBJ([win32-uname])
    AC_LIBOBJ([win32-dirent])
    if test "$enable_networking" = yes ; then
      AC_LIBOBJ([win32-socket])
    fi
    if test "$enable_shared" = yes ; then
      EXTRA_DEFS="-DSCM_IMPORT"
      AC_DEFINE(USE_DLL_IMPORT, 1,
        [Define if you need additional CPP macros on Win32 platforms.])
    fi
    ;;
esac
AC_SUBST(EXTRA_DEFS)

# Reasons for testing:
#   crt_externs.h - Darwin specific
#
AC_CHECK_HEADERS([assert.h crt_externs.h])

# Reasons for testing:
#   DINFINITY - OSF specific
#   DQNAN - OSF specific
#       (DINFINITY and DQNAN are actually global variables, not functions)
#   chsize - an MS-DOS-ism, found in mingw
#   cexp, clog - not in various pre-c99 systems, and note that it's possible
#       for gcc to provide the "complex double" type but the system to not
#       have functions like cexp and clog
#   clog10 - not in mingw (though others like clog and csqrt are)
#   fesetround - available in C99, but not older systems
#   ftruncate - posix, but probably not older systems (current mingw
#               has it as an inline for chsize)
#   ioctl - not in mingw.
#   gmtime_r - recent posix, not on old systems
#   pipe - not in mingw
#   _pipe - specific to mingw, taking 3 args
#   readdir_r - recent posix, not on old systems
#   readdir64_r - not available on HP-UX 11.11
#   stat64 - SuS largefile stuff, not on old systems
#   sysconf - not on old systems
#   truncate - not in mingw
#   isblank - available as a GNU extension or in C99
#   _NSGetEnviron - Darwin specific
#   strcoll_l, newlocale - GNU extensions (glibc), also available on Darwin
#   nl_langinfo - X/Open, not available on Windows.
#
AC_CHECK_FUNCS([DINFINITY DQNAN cexp chsize clog clog10 ctermid fesetround ftime ftruncate fchown getcwd geteuid gettimeofday gmtime_r ioctl lstat mkdir mknod nice pipe _pipe readdir_r readdir64_r readlink rename rmdir select setegid seteuid setlocale setpgid setsid sigaction siginterrupt stat64 strftime strptime symlink sync sysconf tcgetpgrp tcsetpgrp times uname waitpid strdup system usleep atexit on_exit chown link fcntl ttyname getpwent getgrent kill getppid getpgrp fork setitimer getitimer strchr strcmp index bcopy memcpy rindex truncate unsetenv isblank _NSGetEnviron strcoll strcoll_l newlocale nl_langinfo])

# Reasons for testing:
#   netdb.h - not in mingw
#   sys/param.h - not in mingw
#   pthread.h - only available with pthreads.  ACX_PTHREAD doesn't
#       check this specifically, we need it for the timespec test below.
#   sethostname - the function itself check because it's not in mingw,
#       the DECL is checked because Solaris 10 doens't have in any header
#   xlocale.h - needed on Darwin for the `locale_t' API
#   hstrerror - on Tru64 5.1b the symbol is available in libc but the
#       declaration isn't anywhere.
#   cuserid - on Tru64 5.1b the declaration is documented to be available
#       only with `_XOPEN_SOURCE' or some such.
#
AC_CHECK_HEADERS(crypt.h netdb.h pthread.h sys/param.h sys/resource.h sys/file.h xlocale.h)
AC_CHECK_FUNCS(chroot flock getlogin cuserid getpriority setpriority getpass sethostname gethostname)
AC_CHECK_DECLS([sethostname, hstrerror, cuserid])

# crypt() may or may not be available, for instance in some countries there
# are restrictions on cryptography.
#
# crypt() might be in libc (eg. OpenBSD), or it might be in a separate
# -lcrypt library (eg. Debian GNU/Linux).
#
# On HP-UX 11, crypt() is in libc and there's a dummy libcrypt.a.  We must
# be careful to avoid -lcrypt in this case, since libtool will see there's
# only a static libcrypt and decide to build only a static libguile.
#
# AC_SEARCH_LIBS lets us add -lcrypt to LIBS only if crypt() is not in the
# libraries already in that list.
#
AC_SEARCH_LIBS(crypt, crypt,
  [AC_DEFINE(HAVE_CRYPT,1,
             [Define to 1 if you have the `crypt' function.])])

# When compiling with GCC on some OSs (Solaris, AIX), _Complex_I doesn't
# work; in the reported cases so far, 1.0fi works well instead.  According
# to the C99 spec, the complex.h header must provide a working definition
# of _Complex_I, so we always try _Complex_I first.  The 1.0fi fallback
# is a workaround for the failure of some systems to conform to C99.
if test "$ac_cv_type_complex_double" = yes; then
  AC_MSG_CHECKING([for i])
  AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#if HAVE_COMPLEX_H
#include <complex.h>
#endif
complex double z;
]], [[
z = _Complex_I;
]])],
    [AC_DEFINE(GUILE_I,_Complex_I,[The imaginary unit (positive square root of -1).])
     AC_MSG_RESULT([_Complex_I])],
    [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#if HAVE_COMPLEX_H
#include <complex.h>
#endif
complex double z;
]],[[
z = 1.0fi;
]])],
  [AC_DEFINE(GUILE_I,1.0fi)
   AC_MSG_RESULT([1.0fi])],
  [ac_cv_type_complex_double=no
   AC_MSG_RESULT([not available])])])
fi

# glibc 2.3.6 (circa 2006) and various prior versions had a bug where
# csqrt(-i) returned a negative real part, when it should be positive
# for the principal root.
#
if test "$ac_cv_type_complex_double" = yes; then

  AC_CACHE_CHECK([whether csqrt is usable],
    guile_cv_use_csqrt,
    [AC_RUN_IFELSE([AC_LANG_SOURCE([[
#include <complex.h>
/* "volatile" is meant to prevent gcc from calculating the sqrt as a
   constant, we want to test libc. */
volatile complex double z = - _Complex_I;
int
main (void)
{
  z = csqrt (z);	
  if (creal (z) > 0.0)
    return 0;  /* good */
  else
    return 1;  /* bad */
}]])],
    [guile_cv_use_csqrt=yes],
    [guile_cv_use_csqrt="no, glibc 2.3 bug"],
    [guile_cv_use_csqrt="yes, hopefully (cross-compiling)"])])
  case $guile_cv_use_csqrt in
    yes*)
      AC_DEFINE(HAVE_USABLE_CSQRT, 1, [Define to 1 if csqrt is bug-free])
      ;;
  esac
fi


dnl GMP tests
AC_LIB_HAVE_LINKFLAGS(gmp,
  [],
  [#include <gmp.h>],
  [mpz_import (0, 0, 0, 0, 0, 0, 0);],
  AC_MSG_ERROR([GNU MP 4.1 or greater not found, see README]))

dnl GNU libunistring is checked for by Gnulib's `libunistring' module.

dnl i18n tests
#AC_CHECK_HEADERS([libintl.h])
#AC_CHECK_FUNCS(gettext)
#if test $ac_cv_func_gettext = no; then
#   AC_CHECK_LIB(intl, gettext)
#fi
#AC_CHECK_FUNCS([bindtextdomain textdomain])
AM_GNU_GETTEXT([external], [need-ngettext])

### Some systems don't declare some functions.  On such systems, we
### need to at least provide our own K&R-style declarations.

### GUILE_FUNC_DECLARED(function, headerfile)

### Check for a declaration of FUNCTION in HEADERFILE; if it is
### not there, #define MISSING_FUNCTION_DECL.
AC_DEFUN([GUILE_FUNC_DECLARED], [
  AC_CACHE_CHECK(for $1 declaration, guile_cv_func_$1_declared,
    AC_EGREP_HEADER($1, $2,
		    guile_cv_func_$1_declared=yes,
		    guile_cv_func_$1_declared=no))
  if test [x$guile_cv_func_]$1[_declared] = xno; then
    AC_DEFINE([MISSING_]translit($1, [a-z], [A-Z])[_DECL], 1,
      [Define if the operating system supplies $1 without declaring it.])
  fi
])

GUILE_FUNC_DECLARED(sleep, unistd.h)
GUILE_FUNC_DECLARED(usleep, unistd.h)

AC_CHECK_DECLS([strptime],,,
[#define _GNU_SOURCE /* ask glibc to give strptime prototype */
#include <time.h>])

### On some systems usleep has no return value.  If it does have one,
### we'd like to return it; otherwise, we'll fake it.
AC_CACHE_CHECK([return type of usleep], guile_cv_func_usleep_return_type,
  [AC_EGREP_HEADER(changequote(<, >)<void[ 	]+usleep>changequote([, ]),
                   unistd.h,
		   [guile_cv_func_usleep_return_type=void],
		   [guile_cv_func_usleep_return_type=int])])
case "$guile_cv_func_usleep_return_type" in
  "void" )
    AC_DEFINE(USLEEP_RETURNS_VOID, 1,
      [Define if the system headers declare usleep to return void.])
  ;;
esac

AC_CHECK_HEADER(sys/un.h, have_sys_un_h=1)
if test -n "$have_sys_un_h" ; then
  AC_DEFINE(HAVE_UNIX_DOMAIN_SOCKETS, 1,
    [Define if the system supports Unix-domain (file-domain) sockets.])
fi

AC_CHECK_FUNCS(getrlimit setrlimit)

AC_CHECK_FUNCS(socketpair getgroups setgroups setpwent pause tzset)

AC_CHECK_FUNCS(sethostent   gethostent   endhostent   dnl
               setnetent    getnetent    endnetent    dnl
               setprotoent  getprotoent  endprotoent  dnl
               setservent   getservent   endservent   dnl
               getnetbyaddr getnetbyname dnl
	       inet_lnaof inet_makeaddr inet_netof hstrerror dnl
	       inet_pton inet_ntop)

# struct sockaddr field sin_len is only present on BSD systems.
# On 4.4BSD apparently a #define SIN_LEN exists, but on other BSD systems
# (eg. FreeBSD 4.9) it doesn't and we must use this configure check
AC_CHECK_MEMBERS([struct sockaddr.sin_len],,,
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <netinet/in.h>])

AC_MSG_CHECKING(for __libc_stack_end)
AC_CACHE_VAL(guile_cv_have_libc_stack_end,
[AC_LINK_IFELSE([AC_LANG_PROGRAM([[#include <stdio.h>
extern char *__libc_stack_end;]],
   [[printf("%p", (char*) __libc_stack_end);]])],
   [guile_cv_have_libc_stack_end=yes],
   [guile_cv_have_libc_stack_end=no])])
AC_MSG_RESULT($guile_cv_have_libc_stack_end)

if test $guile_cv_have_libc_stack_end = yes; then
  AC_DEFINE(HAVE_LIBC_STACK_END, 1,
           [Define if you have the __libc_stack_end variable.])
fi

dnl Some systems do not declare this.  Some systems do declare it, as a
dnl macro.  With cygwin it may be in a DLL.

AC_MSG_CHECKING(whether netdb.h declares h_errno)
AC_CACHE_VAL(guile_cv_have_h_errno,
  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <netdb.h>]],
                                      [[int a = h_errno;]])],
  [guile_cv_have_h_errno=yes],
  [guile_cv_have_h_errno=no])])
AC_MSG_RESULT($guile_cv_have_h_errno)
if test $guile_cv_have_h_errno = yes; then
  AC_DEFINE(HAVE_H_ERRNO, 1, [Define if h_errno is declared in netdb.h.])
fi

AC_MSG_CHECKING(whether uint32_t is defined)
AC_CACHE_VAL(guile_cv_have_uint32_t,
  [AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[#include <sys/types.h>
		   #if HAVE_STDINT_H
		   #include <stdint.h>
                   #endif
		   #ifndef HAVE_NETDB_H
	           #include <netdb.h>
		   #endif]],
		   [[uint32_t a;]])],
		   [guile_cv_have_uint32_t=yes],
		   [guile_cv_have_uint32_t=no])])
AC_MSG_RESULT($guile_cv_have_uint32_t)
if test $guile_cv_have_uint32_t = yes; then
  AC_DEFINE(HAVE_UINT32_T, 1,
    [Define if uint32_t typedef is defined when netdb.h is include.])
fi

AC_MSG_CHECKING(for working IPv6 support)
AC_CACHE_VAL(guile_cv_have_ipv6,
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <netinet/in.h>
#include <sys/socket.h>]],
[[struct sockaddr_in6 a;  a.sin6_family = AF_INET6;]])],
[guile_cv_have_ipv6=yes],
[guile_cv_have_ipv6=no])])
AC_MSG_RESULT($guile_cv_have_ipv6)
if test $guile_cv_have_ipv6 = yes; then
  AC_DEFINE(HAVE_IPV6, 1, [Define if you want support for IPv6.])
fi

# included in rfc2553 but not in older implementations, e.g., glibc 2.1.3.
AC_MSG_CHECKING(whether sockaddr_in6 has sin6_scope_id)
AC_CACHE_VAL(guile_cv_have_sin6_scope_id,
[AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <netinet/in.h>]],
[[struct sockaddr_in6 sok;  sok.sin6_scope_id = 0;]])],
[guile_cv_have_sin6_scope_id=yes],
[guile_cv_have_sin6_scope_id=no])])
AC_MSG_RESULT($guile_cv_have_sin6_scope_id)
if test $guile_cv_have_sin6_scope_id = yes; then
  AC_DEFINE(HAVE_SIN6_SCOPE_ID, 1,
    [Define this if your IPv6 has sin6_scope_id in sockaddr_in6 struct.])
fi

# struct sockaddr_in6 field sin_len is only present on BSD systems
AC_CHECK_MEMBERS([struct sockaddr_in6.sin6_len],,,
[#ifdef HAVE_SYS_TYPES_H
#include <sys/types.h>
#endif
#include <netinet/in.h>])

AC_MSG_CHECKING(whether localtime caches TZ)
AC_CACHE_VAL(guile_cv_localtime_cache,
[if test x$ac_cv_func_tzset = xyes; then
AC_RUN_IFELSE([AC_LANG_SOURCE([[#include <time.h>
#if STDC_HEADERS
# include <stdlib.h>
#endif
extern char **environ;
unset_TZ ()
{
  char **from, **to;
  for (to = from = environ; (*to = *from); from++)
    if (! (to[0][0] == 'T' && to[0][1] == 'Z' && to[0][2] == '='))
      to++;
}
char TZ_GMT0[] = "TZ=GMT0";
char TZ_PST8[] = "TZ=PST8";
main()
{
  time_t now = time ((time_t *) 0);
  int hour_GMT0, hour_unset;
  if (putenv (TZ_GMT0) != 0)
    exit (1);
  hour_GMT0 = localtime (&now)->tm_hour;
  unset_TZ ();
  hour_unset = localtime (&now)->tm_hour;
  if (putenv (TZ_PST8) != 0)
    exit (1);
  if (localtime (&now)->tm_hour == hour_GMT0)
    exit (1);
  unset_TZ ();
  if (localtime (&now)->tm_hour != hour_unset)
    exit (1);
  exit (0);
}]])],
[guile_cv_localtime_cache=no],
[guile_cv_localtime_cache=yes],
[# If we have tzset, assume the worst when cross-compiling.
guile_cv_localtime_cache=yes])
else
        # If we lack tzset, report that localtime does not cache TZ,
        # since we can't invalidate the cache if we don't have tzset.
        guile_cv_localtime_cache=no
fi])dnl
AC_MSG_RESULT($guile_cv_localtime_cache)
if test $guile_cv_localtime_cache = yes; then
  AC_DEFINE(LOCALTIME_CACHE, 1, [Define if localtime caches the TZ setting.])
fi

if test "$enable_regex" = yes; then
   if test "$ac_cv_header_regex_h" = yes ||
      test "$ac_cv_header_rxposix_h" = yes ||
      test "$ac_cv_header_rx_rxposix_h" = yes; then
     GUILE_NAMED_CHECK_FUNC(regcomp, norx, [AC_LIBOBJ([regex-posix])],
     [AC_CHECK_LIB(rx, main)
      GUILE_NAMED_CHECK_FUNC(regcomp, rx, [AC_LIBOBJ([regex-posix])],
     [AC_CHECK_LIB(regex, main)
      GUILE_NAMED_CHECK_FUNC(regcomp, regex, [AC_LIBOBJ([regex-posix])])])]
     )
     dnl The following should not be necessary, but for some reason
     dnl autoheader misses it if we don't include it!
     if test "$ac_cv_func_regcomp_norx" = yes ||
        test "$ac_cv_func_regcomp_regex" = yes ||
        test "$ac_cv_func_regcomp_rx" = yes; then
       AC_DEFINE(HAVE_REGCOMP, 1,
         [This is included as part of a workaround for a autoheader bug.])
     fi
   fi
fi

AC_REPLACE_FUNCS(inet_aton putenv strerror memmove mkstemp)

AC_CHECK_HEADERS(floatingpoint.h ieeefp.h nan.h)

# Reasons for testing:
#   asinh, acosh, atanh, trunc - C99 standard, generally not available on
#                                older systems
#   sincos - GLIBC extension
#
AC_CHECK_FUNCS(asinh acosh atanh copysign finite sincos trunc)

# C99 specifies isinf and isnan as macros.
# HP-UX provides only macros, no functions.
# glibc 2.3.2 provides both macros and functions.
# IRIX 6.5 and Solaris 8 only provide functions.
#
# The following tests detect isinf and isnan either as functions or as
# macros from <math.h>.  Plain AC_CHECK_FUNCS is insufficient, it doesn't
# use <math.h> so doesn't detect on macro-only systems like HP-UX.
#
AC_MSG_CHECKING([for isinf])
AC_LINK_IFELSE(AC_LANG_SOURCE(
[[#include <math.h>
volatile double x = 0.0;
int main () { return (isinf(x) != 0); }]]),
  [AC_MSG_RESULT([yes])
   AC_DEFINE(HAVE_ISINF, 1,
             [Define to 1 if you have the `isinf' macro or function.])],
  [AC_MSG_RESULT([no])])
AC_MSG_CHECKING([for isnan])
AC_LINK_IFELSE(AC_LANG_SOURCE(
[[#include <math.h>
volatile double x = 0.0;
int main () { return (isnan(x) != 0); }]]),
  [AC_MSG_RESULT([yes])
   AC_DEFINE(HAVE_ISNAN, 1,
             [Define to 1 if you have the `isnan' macro or function.])],
  [AC_MSG_RESULT([no])])

# Reasons for checking:
#
#     st_rdev
#     st_blksize
#     st_blocks   not in mingw
#     tm_gmtoff   BSD+GNU, not in C99
#
# Note AC_STRUCT_ST_BLOCKS is not used here because we don't want the
# AC_LIBOBJ(fileblocks) replacement which that macro gives.
#
AC_CHECK_MEMBERS([struct stat.st_rdev, struct stat.st_blksize, struct stat.st_blocks])

AC_STRUCT_TIMEZONE
AC_CHECK_MEMBERS([struct tm.tm_gmtoff],,,
[#include <time.h>
#ifdef TIME_WITH_SYS_TIME
# include <sys/time.h>
# include <time.h>
#else
# if HAVE_SYS_TIME_H
#  include <sys/time.h>
# else
#  include <time.h>
# endif
#endif
])
GUILE_STRUCT_UTIMBUF


#--------------------------------------------------------------------
#
# Which way does the stack grow?
#
# Following code comes from Autoconf 2.61's internal _AC_LIBOBJ_ALLOCA
# macro (/usr/share/autoconf/autoconf/functions.m4).  Gnulib has
# very similar code, so in future we could look at using that.
#
# An important detail is that the code involves find_stack_direction
# calling _itself_ - which means that find_stack_direction (or at
# least the second find_stack_direction() call) cannot be inlined.
# If the code could be inlined, that might cause the test to give
# an incorrect answer.
#--------------------------------------------------------------------

SCM_I_GSC_STACK_GROWS_UP=0
AC_RUN_IFELSE([AC_LANG_SOURCE(
[AC_INCLUDES_DEFAULT
int
find_stack_direction ()
{
  static char *addr = 0;
  auto char dummy;
  if (addr == 0)
    {
      addr = &dummy;
      return find_stack_direction ();
    }
  else
    return (&dummy > addr) ? 1 : -1;
}

int
main ()
{
  return find_stack_direction () < 0;
}])],
	       [SCM_I_GSC_STACK_GROWS_UP=1],
	       [],
	       [AC_MSG_WARN(Guessing that stack grows down -- see scmconfig.h)])

AC_CHECK_SIZEOF(float)
if test "$ac_cv_sizeof_float" -le "$ac_cv_sizeof_long"; then
    AC_DEFINE(SCM_SINGLES, 1, 
              [Define this if floats are the same size as longs.])
fi

AC_MSG_CHECKING(for struct linger)
AC_CACHE_VAL(scm_cv_struct_linger,
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <sys/types.h>
#include <sys/socket.h>]],
	                  [[struct linger lgr;  lgr.l_linger = 100]])],
			  [scm_cv_struct_linger="yes"],
			  [scm_cv_struct_linger="no"]))
AC_MSG_RESULT($scm_cv_struct_linger)
if test $scm_cv_struct_linger = yes; then
	AC_DEFINE(HAVE_STRUCT_LINGER, 1,
          [Define this if your system defines struct linger, for use with the
           getsockopt and setsockopt system calls.])
fi


# On mingw, struct timespec is in <pthread.h>.
#
AC_MSG_CHECKING(for struct timespec)
AC_CACHE_VAL(scm_cv_struct_timespec,
	AC_COMPILE_IFELSE([AC_LANG_PROGRAM([[
#include <time.h>
#if HAVE_PTHREAD_H
#include <pthread.h>
#endif]], [[struct timespec t;  t.tv_nsec = 100]])],
          [scm_cv_struct_timespec="yes"],
          [scm_cv_struct_timespec="no"]))
AC_MSG_RESULT($scm_cv_struct_timespec)
if test $scm_cv_struct_timespec = yes; then
  AC_DEFINE(HAVE_STRUCT_TIMESPEC, 1,
    [Define this if your system defines struct timespec via either <time.h> or <pthread.h>.])
fi

#--------------------------------------------------------------------
#
# Flags for thread support
#
#--------------------------------------------------------------------

SCM_I_GSC_USE_PTHREAD_THREADS=0
SCM_I_GSC_USE_NULL_THREADS=0
AC_SUBST([SCM_I_GSC_USE_PTHREAD_THREADS])
AC_SUBST([SCM_I_GSC_USE_NULL_THREADS])

### What thread package has the user asked for?
AC_ARG_WITH(threads, [  --with-threads          thread interface],
            , with_threads=yes)

AC_SUBST(SCM_I_GSC_NEED_BRACES_ON_PTHREAD_ONCE_INIT, 0)
AC_SUBST(SCM_I_GSC_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER, 0)

case "$with_threads" in
  "yes" | "pthread" | "pthreads" | "pthread-threads" | "")

    build_pthread_support="yes"

    ACX_PTHREAD([CC="$PTHREAD_CC"
       LIBS="$PTHREAD_LIBS $LIBS"
       SCM_I_GSC_USE_PTHREAD_THREADS=1
       with_threads="pthreads"],
      [with_threads="null"
       build_pthread_support="no"])

    old_CFLAGS="$CFLAGS"
    CFLAGS="$PTHREAD_CFLAGS $CFLAGS"

    # Reasons for testing:
    #     pthread_getattr_np - "np" meaning "non portable" says it
    #         all; not present on MacOS X or Solaris 10
    #     pthread_get_stackaddr_np - "np" meaning "non portable" says it
    #         all; specific to MacOS X
    #     pthread_sigmask - not available on mingw
    #
    AC_CHECK_FUNCS(pthread_attr_getstack pthread_getattr_np pthread_get_stackaddr_np pthread_sigmask)

    # On past versions of Solaris, believe 8 through 10 at least, you
    # had to write "pthread_once_t foo = { PTHREAD_ONCE_INIT };".
    # This is contrary to POSIX:
    # http://www.opengroup.org/onlinepubs/000095399/functions/pthread_once.html
    # Check here if this style is required.
    #
    # glibc (2.3.6 at least) works both with or without braces, so the
    # test checks whether it works without.
    #

    if test "$GCC" = "yes"; then
      # Since GCC only issues a warning for missing braces, so we need
      # `-Werror' to catch it.
      CFLAGS="-Werror -Wmissing-braces $CFLAGS"
    fi

    AC_CACHE_CHECK([whether PTHREAD_ONCE_INIT needs braces],
      guile_cv_need_braces_on_pthread_once_init,
      [AC_COMPILE_IFELSE([#include <pthread.h>
         pthread_once_t foo = PTHREAD_ONCE_INIT;],
        [guile_cv_need_braces_on_pthread_once_init=no],
        [guile_cv_need_braces_on_pthread_once_init=yes])])
    if test "$guile_cv_need_braces_on_pthread_once_init" = yes; then
      SCM_I_GSC_NEED_BRACES_ON_PTHREAD_ONCE_INIT=1
    fi

    # Same problem with `PTHREAD_MUTEX_INITIALIZER', e.g., on IRIX
    # 6.5.30m with GCC 3.3.
    AC_CACHE_CHECK([whether PTHREAD_MUTEX_INITIALIZER needs braces],
      guile_cv_need_braces_on_pthread_mutex_initializer,
      [AC_COMPILE_IFELSE([#include <pthread.h>
         pthread_mutex_t foo = PTHREAD_MUTEX_INITIALIZER;],
        [guile_cv_need_braces_on_pthread_mutex_initializer=no],
        [guile_cv_need_braces_on_pthread_mutex_initializer=yes])])
    if test "$guile_cv_need_braces_on_pthread_mutex_initializer" = yes; then
      SCM_I_GSC_NEED_BRACES_ON_PTHREAD_MUTEX_INITIALIZER=1
    fi

    CFLAGS="$old_CFLAGS"

    # On Solaris, sched_yield lives in -lrt.
    AC_SEARCH_LIBS(sched_yield, rt)
    
  ;;
esac

case "$with_threads" in
  "pthreads")
  ;;
  "no" | "null")
    SCM_I_GSC_USE_NULL_THREADS=1
    with_threads="null-threads"
  ;;
  * )
    AC_MSG_ERROR(invalid value for --with-threads: $with_threads)
  ;;
esac

AC_MSG_CHECKING(what kind of threads to support)
AC_MSG_RESULT($with_threads)

AM_CONDITIONAL([BUILD_PTHREAD_SUPPORT],
  [test "x$build_pthread_support" = "xyes"])


## Check whether pthread_attr_getstack works for the main thread

if test "$with_threads" = pthreads; then

AC_MSG_CHECKING(whether pthread_attr_getstack works for the main thread)
old_CFLAGS="$CFLAGS"
CFLAGS="$PTHREAD_CFLAGS $CFLAGS"
AC_RUN_IFELSE([AC_LANG_SOURCE([[
#if HAVE_PTHREAD_ATTR_GETSTACK
#include <pthread.h>

int main ()
{
  pthread_attr_t attr;
  void *start, *end;
  size_t size;

  pthread_getattr_np (pthread_self (), &attr);
  pthread_attr_getstack (&attr, &start, &size);
  end = (char *)start + size;

  if ((void *)&attr < start || (void *)&attr >= end)
    return 1;
  else
    return 0;
}
#else
int main ()
{
  return 1;
}
#endif
]])],
[works=yes
AC_DEFINE(PTHREAD_ATTR_GETSTACK_WORKS, [1], [Define when pthread_att_get_stack works for the main thread])],
[works=no],
[])
CFLAGS="$old_CFLAGS"
AC_MSG_RESULT($works)

fi # with_threads=pthreads


## Cross building	
if test "$cross_compiling" = "yes"; then
  AC_MSG_CHECKING(cc for build)
  ## /usr/bin/cc still uses wrong assembler
  ## CC_FOR_BUILD="${CC_FOR_BUILD-/usr/bincc}"
  CC_FOR_BUILD="${CC_FOR_BUILD-PATH=/usr/bin:$PATH cc}"
else
  CC_FOR_BUILD="${CC_FOR_BUILD-$CC}"
fi   
     
## AC_MSG_CHECKING("if we are cross compiling")
## AC_MSG_RESULT($cross_compiling)
if test "$cross_compiling" = "yes"; then
   AC_MSG_RESULT($CC_FOR_BUILD)
fi

## No need as yet to be more elaborate
CCLD_FOR_BUILD="$CC_FOR_BUILD"

AC_SUBST(cross_compiling)
AC_ARG_VAR(CC_FOR_BUILD,[build system C compiler])
AC_SUBST(CCLD_FOR_BUILD)
	
## libtool erroneously calls CC_FOR_BUILD HOST_CC;
## --HOST is the platform that PACKAGE is compiled for.
HOST_CC="$CC_FOR_BUILD"
AC_SUBST(HOST_CC)

if test "$cross_compiling" = "yes"; then
  AC_MSG_CHECKING(guile for build)
  GUILE_FOR_BUILD="${GUILE_FOR_BUILD-guile}"
else
  GUILE_FOR_BUILD='$(preinstguile)'
fi   

## AC_MSG_CHECKING("if we are cross compiling")
## AC_MSG_RESULT($cross_compiling)
if test "$cross_compiling" = "yes"; then
   AC_MSG_RESULT($GUILE_FOR_BUILD)
fi
AC_ARG_VAR(GUILE_FOR_BUILD,[guile for build system])
AC_SUBST(GUILE_FOR_BUILD)
  			
## If we're using GCC, ask for aggressive warnings.
case "$GCC" in
  yes )
    ## We had -Wstrict-prototypes in here for a bit, but Guile does too
    ## much stuff with generic function pointers for that to really be
    ## less than exasperating.
    ## -Wpointer-arith was here too, but something changed in gcc/glibc
    ## and it became equally exasperating (gcc 2.95 and/or glibc 2.1.2).
    GCC_CFLAGS="-Wall -Wmissing-prototypes"
    # Do this here so we don't screw up any of the tests above that might
    # not be "warning free"
    if test "${GUILE_ERROR_ON_WARNING}" = yes
    then
	GCC_CFLAGS="${GCC_CFLAGS} -Werror"
	enable_compile_warnings=no
    fi
    ;;
esac

AC_SUBST(GCC_CFLAGS)

## If we're creating a shared library (using libtool!), then we'll
## need to generate a list of .lo files corresponding to the .o files
## given in LIBOBJS.  We'll call it LIBLOBJS.
LIBLOBJS="`echo ${LIB@&t@OBJS} | sed 's,\.[[^.]]* ,.lo ,g;s,\.[[^.]]*$,.lo,'`"

## We also need to create corresponding .doc and .x files
EXTRA_DOT_DOC_FILES="`echo ${LIB@&t@OBJS} | sed 's,\.[[^.]]* ,.doc ,g;s,\.[[^.]]*$,.doc,'`"
EXTRA_DOT_X_FILES="`echo ${LIB@&t@OBJS} | sed 's,\.[[^.]]* ,.x ,g;s,\.[[^.]]*$,.x,'`"

# GNU Readline bindings.
GUILE_READLINE

AC_SUBST(GUILE_MAJOR_VERSION)
AC_SUBST(GUILE_MINOR_VERSION)
AC_SUBST(GUILE_MICRO_VERSION)
AC_SUBST(GUILE_EFFECTIVE_VERSION)
AC_SUBST(GUILE_VERSION)

#######################################################################
# library versioning

AC_SUBST(LIBGUILE_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_INTERFACE_AGE)
AC_SUBST(LIBGUILE_INTERFACE)

AC_SUBST(LIBGUILE_SRFI_SRFI_1_MAJOR)
AC_SUBST(LIBGUILE_SRFI_SRFI_1_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_SRFI_SRFI_1_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_SRFI_SRFI_1_INTERFACE_AGE)
AC_SUBST(LIBGUILE_SRFI_SRFI_1_INTERFACE)

AC_SUBST(LIBGUILE_SRFI_SRFI_4_MAJOR)
AC_SUBST(LIBGUILE_SRFI_SRFI_4_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_SRFI_SRFI_4_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_SRFI_SRFI_4_INTERFACE_AGE)
AC_SUBST(LIBGUILE_SRFI_SRFI_4_INTERFACE)

AC_SUBST(LIBGUILE_SRFI_SRFI_13_14_MAJOR)
AC_SUBST(LIBGUILE_SRFI_SRFI_13_14_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_SRFI_SRFI_13_14_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_SRFI_SRFI_13_14_INTERFACE_AGE)
AC_SUBST(LIBGUILE_SRFI_SRFI_13_14_INTERFACE)

AC_SUBST(LIBGUILE_SRFI_SRFI_60_MAJOR)
AC_SUBST(LIBGUILE_SRFI_SRFI_60_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_SRFI_SRFI_60_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_SRFI_SRFI_60_INTERFACE_AGE)
AC_SUBST(LIBGUILE_SRFI_SRFI_60_INTERFACE)

AC_SUBST(LIBGUILE_I18N_MAJOR)
AC_SUBST(LIBGUILE_I18N_INTERFACE_CURRENT)
AC_SUBST(LIBGUILE_I18N_INTERFACE_REVISION)
AC_SUBST(LIBGUILE_I18N_INTERFACE_AGE)
AC_SUBST(LIBGUILE_I18N_INTERFACE)


#######################################################################

dnl Tell guile-config what flags guile users should compile and link with.
GUILE_LIBS="$LDFLAGS $LIBS"
GUILE_CFLAGS="$CPPFLAGS $PTHREAD_CFLAGS"
AC_SUBST(GUILE_LIBS)
AC_SUBST(GUILE_CFLAGS)

AC_SUBST(AWK)
AC_SUBST(LIBLOBJS)
AC_SUBST(EXTRA_DOT_DOC_FILES)
AC_SUBST(EXTRA_DOT_X_FILES)

dnl See also top_builddir in info node: (libtool)AC_PROG_LIBTOOL
top_builddir_absolute=`pwd`
AC_SUBST(top_builddir_absolute)
top_srcdir_absolute=`(cd $srcdir && pwd)`
AC_SUBST(top_srcdir_absolute)

dnl We need `sitedir' in `guile-1.8.pc'.
dnl Note: `sitedir' must be kept in sync with `GUILE_SITE_DIR' in `guile.m4'.
pkgdatadir="$datadir/guile"
sitedir="$pkgdatadir/site"
AC_SUBST([sitedir])

# Additional SCM_I_GSC definitions are above.
AC_SUBST([SCM_I_GSC_GUILE_DEBUG])
AC_SUBST([SCM_I_GSC_GUILE_DEBUG_FREELIST])
AC_SUBST([SCM_I_GSC_ENABLE_DISCOURAGED])
AC_SUBST([SCM_I_GSC_ENABLE_DEPRECATED])
AC_SUBST([SCM_I_GSC_ENABLE_ELISP])
AC_SUBST([SCM_I_GSC_STACK_GROWS_UP])
AC_SUBST([SCM_I_GSC_C_INLINE])
AC_CONFIG_FILES([libguile/gen-scmconfig.h])

AC_CONFIG_FILES([
  Makefile
  am/Makefile
  lib/Makefile
  benchmark-suite/Makefile
  doc/Makefile
  doc/r5rs/Makefile
  doc/ref/Makefile
  doc/tutorial/Makefile
  emacs/Makefile
  examples/Makefile
  lang/Makefile
  libguile/Makefile
  srfi/Makefile
  guile-readline/Makefile
  test-suite/Makefile
  test-suite/standalone/Makefile
  meta/Makefile
  module/Makefile
  testsuite/Makefile
])

AC_CONFIG_FILES([meta/guile-2.0.pc])
AC_CONFIG_FILES([meta/guile-2.0-uninstalled.pc])
AC_CONFIG_FILES([check-guile], [chmod +x check-guile])
AC_CONFIG_FILES([benchmark-guile], [chmod +x benchmark-guile])
AC_CONFIG_FILES([meta/guile], [chmod +x meta/guile])
AC_CONFIG_FILES([meta/uninstalled-env], [chmod +x meta/uninstalled-env])
AC_CONFIG_FILES([meta/gdb-uninstalled-guile], [chmod +x meta/gdb-uninstalled-guile])
AC_CONFIG_FILES([meta/guile-tools], [chmod +x meta/guile-tools])
AC_CONFIG_FILES([libguile/guile-snarf],
                [chmod +x libguile/guile-snarf])
AC_CONFIG_FILES([libguile/guile-doc-snarf],
                [chmod +x libguile/guile-doc-snarf])
AC_CONFIG_FILES([libguile/guile-func-name-check],
                [chmod +x libguile/guile-func-name-check])
AC_CONFIG_FILES([libguile/guile-snarf-docs],
                [chmod +x libguile/guile-snarf-docs])
AC_CONFIG_FILES([test-suite/standalone/test-use-srfi],
                [chmod +x test-suite/standalone/test-use-srfi])
AC_CONFIG_FILES([test-suite/standalone/test-fast-slot-ref],
                [chmod +x test-suite/standalone/test-fast-slot-ref])
AC_CONFIG_FILES([doc/ref/effective-version.texi])

AC_OUTPUT

dnl Local Variables:
dnl comment-start: "dnl "
dnl comment-end: ""
dnl comment-start-skip: "\\bdnl\\b\\s *"
dnl End: