cpython/configure.in

dnl Process this file with autoconf 2.0 or later to make a configure script.
AC_REVISION($Revision$)
AC_PREREQ(2.0)
AC_INIT(Include/object.h)
AC_CONFIG_HEADER(config.h)

# Set VERSION so we only need to edit in one place (i.e., here)
AC_SUBST(VERSION)
VERSION=2.0

# NEXTSTEP|MacOSX|Darwin stuff
if test -f /usr/lib/NextStep/software_version -o -f /System/Library/CoreServices/software_version ; then

	AC_MSG_CHECKING(for --with-next-archs)
	AC_ARG_WITH(next-archs,
	 [  --with-next-archs='arch1 arch2 ..'   build MAB binary], [
		if test -n "$withval"; then
		    ac_arch_flags=`/usr/lib/arch_tool -archify_list $withval`
		    # GCC does not currently support multi archs on the NeXT
		    with_gcc=no
		fi
		AC_MSG_RESULT($with_next_archs)
	], [AC_MSG_RESULT(none: using `arch`)])
	
	if test -z "$MACHDEP"
	then
	    ac_sys_system=`uname -s`
	    if test "$ac_sys_system" = "Darwin" ; then
		ac_sys_release=`uname -r`
	    else
		set X `hostinfo | egrep '(NeXT Mach|Kernel Release).*:' | \
			sed -e 's/://' -e 's/\./_/'` && \
		ac_sys_system=next && ac_sys_release=$4
	    fi

	    MACHDEP="$ac_sys_system$ac_sys_release"
	fi
fi

AC_ARG_WITH(next-framework,
[  --with-next-framework           Build (OpenStep|Rhapsody|MacOSX|Darwin) framework],,)
AC_ARG_WITH(dyld,
[  --with-dyld                     Use (OpenStep|Rhapsody|MacOSX|Darwin) dynamic linker],,)

# Set name for machine-dependent library files
AC_SUBST(MACHDEP)
AC_MSG_CHECKING(MACHDEP)
if test -z "$MACHDEP"
then
	ac_sys_system=`uname -s`
	if test "$ac_sys_system" = "AIX" -o "$ac_sys_system" = "Monterey64"; then
		ac_sys_release=`uname -v`
	else
		ac_sys_release=`uname -r`
	fi
	ac_md_system=`echo $ac_sys_system |
			   tr -d '[/ ]' | tr '[[A-Z]]' '[[a-z]]'`
	ac_md_release=`echo $ac_sys_release |
			   tr -d '[/ ]' | sed 's/\..*//'`
	MACHDEP="$ac_md_system$ac_md_release"

	case $MACHDEP in
	'')	MACHDEP="unknown";;
	esac
fi

#
# SGI compilers allow the specification of the both the ABI and the
# ISA on the command line.  Depending on the values of these switches,
# different and often incompatable code will be generated.
#
# The SGI_ABI variable can be used to modify the CC and LDFLAGS and
# thus supply support for various ABI/ISA combinations.  The MACHDEP
# variable is also adjusted.
#
AC_SUBST(SGI_ABI)
if test ! -z "$SGI_ABI"
then
        CC="cc $SGI_ABI"
        LDFLAGS="$SGI_ABI $LDFLAGS"
        MACHDEP=`echo "${MACHDEP}${SGI_ABI}" | sed 's/ *//g'`
fi
AC_MSG_RESULT($MACHDEP)

#
# CCC is the command that compiles C++ programs
#
# Not all make programs have this predefined.
#
#AC_SUBST(SET_CCC)
#AC_MSG_CHECKING(CCC)
#if test -z "$CCC"
#then
#	case $ac_sys_system in
#	IRIX*)	SET_CCC="CCC= CC ${SGI_ABI}";;
#	Linux*) SET_CCC="CCC= g++";;
#	*)	SET_CCC=""
#	esac
#else
#        SET_CCC="CCC= ${CCC}"
#fi
#AC_MSG_RESULT($SET_CCC)


# checks for alternative programs
AC_MSG_CHECKING(for --without-gcc)
AC_ARG_WITH(gcc, [  --without-gcc                   never use gcc], [
	case $withval in
	no)	CC=cc
		without_gcc=yes;;
	yes)	CC=gcc
		without_gcc=no;;
	*)	CC=$withval
		without_gcc=$withval;;
	esac], [
	case $ac_sys_system in
	OSF1)	CC=cc
		without_gcc=;;
	BeOS*)
		case $BE_HOST_CPU in
		ppc)
			CC=mwcc
			without_gcc=yes
			OPT="-O -D'DL_EXPORT(RTYPE)=__declspec(dllexport) RTYPE' -D'DL_IMPORT(RTYPE)=__declspec(dllexport) RTYPE' -export pragma"
			CCSHARED="UDL_IMPORT -D'DL_IMPORT(RTYPE)=__declspec(dllimport) RTYPE'"
			LDFLAGS="$LDFLAGS -nodup"

			AR="$PWD/BeOS/ar-fake"
			RANLIB=:
			;;
		x86)
			CC=gcc
			without_gcc=no
			OPT=-O
			# Really should use srcdir instead of PWD
			AR="$PWD/BeOS/ar-fake"
			RANLIB=:
			;;
		*)
			AC_ERROR(Unknown BeOS platform \"$BE_HOST_CPU\")
			;;
		esac
		;;
    Monterey*)
        RANLIB=:
        without_gcc=;;
	*)	without_gcc=no;;
	esac])
AC_MSG_RESULT($without_gcc)

AC_SUBST(SET_CXX)
AC_SUBST(MAINOBJ)
MAINOBJ=python.o
AC_MSG_CHECKING(for --with-cxx=<compiler>)
AC_ARG_WITH(cxx, [  --with-cxx=<compiler>           enable C++ support],[
	check_cxx=no
	case $withval in
	no)	CXX=
		with_cxx=no;;
	*)	CXX=$withval
		MAINOBJ=ccpython.o
		with_cxx=$withval;;
	esac], [
	with_cxx=no
	check_cxx=yes
])
AC_MSG_RESULT($with_cxx)

dnl The following fragment works similar to AC_PROG_CXX.
dnl It does not fail if CXX is not found, and it is not executed if 
dnl --with-cxx was given.
dnl Finally, it does not test whether CXX is g++.

if test "$check_cxx" = "yes" 
then
	AC_CHECK_PROGS(CXX, $CCC c++ g++ gcc CC cxx cc++ cl, notfound)
	if test "$CXX" = "notfound"
	then
		CXX=
	else
		AC_PROG_CXX_WORKS
	fi
fi

SET_CXX="CXX=$CXX"


#AC_MSG_CHECKING(CCC)
#if test -z "$CCC"
#then
#	case $ac_sys_system in
#	IRIX*)	SET_CCC="CCC= CC ${SGI_ABI}";;
#	Linux*) SET_CCC="CCC= g++";;
#	*)	SET_CCC=""
#	esac
#else
#        SET_CCC="CCC= ${CCC}"
#fi
#AC_MSG_RESULT($SET_CCC)

# If the user switches compilers, we can't believe the cache
if test ! -z "$ac_cv_prog_CC" -a ! -z "$CC" -a "$CC" != "$ac_cv_prog_CC"
then
  AC_ERROR(cached CC is different -- throw away $cache_file
(it is also a good idea to do 'make clean' before compiling))
fi

AC_PROG_CC
AC_SUBST(EXE)
AC_MSG_CHECKING(for --with-suffix)
AC_ARG_WITH(suffix, [  --with-suffix=.exe              set executable suffix],[
	case $withval in
	no)	EXE=;;
	yes)	EXE=.exe;;
	*)	EXE=$withval;;
	esac])
AC_MSG_RESULT($EXE)

case $MACHDEP in
bsdos*)
    case $CC in
    gcc) CC="$CC -D_HAVE_BSDI";;
    esac;;
esac

case $ac_sys_system in
hp*|HP*)
    case $CC in
    cc|*/cc) CC="$CC -Ae";;
    esac;;
Monterey*)
    case $CC in
    cc) CC="$CC -Wl,-Bexport";;
    esac;;
esac

# LDLIBRARY is the name of the library to link against (as opposed to the
# name of the library into which to insert object files). On systems
# without shared libraries, LDLIBRARY is the same as LIBRARY (defined in
# the Makefiles). 
AC_SUBST(MAKE_LDLIBRARY)
AC_SUBST(LDLIBRARY)
LDLIBRARY=''

# LINKCC is the command that links the python executable -- default is $(CC).
# This is altered for AIX in order to build the export list before 
# linking.
AC_SUBST(LINKCC)
AC_MSG_CHECKING(LINKCC)
if test -z "$LINKCC" -a ! -z "$CXX"
then
    LINKCC="$CXX"
fi
if test -z "$LINKCC"
then
	case $ac_sys_system in
	AIX*)
	   LINKCC="\$(srcdir)/makexp_aix python.exp \"\" \$(LIBRARY); \$(PURIFY) \$(CC)";;
	dgux*)
	   LINKCC="LD_RUN_PATH=$libdir \$(PURIFY) \$(CC)";;
	Monterey64*)
	   LINKCC="\$(PURIFY) \$(CC) -L/usr/lib/ia64l64";;
	*) LINKCC="\$(PURIFY) \$(CC)";;
	esac
fi
AC_MSG_RESULT($LINKCC)

AC_MSG_CHECKING(LDLIBRARY)

# NeXT framework builds require that the 'ar' library be converted into
# a bundle using libtool.
if test "$with_next_framework"
then
  LDLIBRARY='libpython$(VERSION).dylib'
fi  

# DG/UX requires some fancy ld contortions to produce a .so from an .a
case $MACHDEP in
dguxR4)
      LDLIBRARY='libpython$(VERSION).so'
      OPT="$OPT -pic"
      ;;
beos*)
      LDLIBRARY='libpython$(VERSION).so'
      ;;
esac
AC_MSG_RESULT($LDLIBRARY)

# If LDLIBRARY is different from LIBRARY, emit a rule to build it.
if test -z "$LDLIBRARY"
then
  LDLIBRARY='libpython$(VERSION).a'
  MAKE_LDLIBRARY="true"
else
  MAKE_LDLIBRARY='$(MAKE) $(LDLIBRARY)'
fi

AC_PROG_RANLIB
AC_SUBST(AR)
AC_CHECK_PROGS(AR, ar aal, ar)
AC_SUBST(INSTALL)
AC_SUBST(INSTALL_PROGRAM)
AC_SUBST(INSTALL_DATA)
# Install just never works :-(
if test -z "$INSTALL"
then
	INSTALL=cp
	INSTALL_PROGRAM=cp
	INSTALL_DATA=cp
else
	INSTALL_PROGRAM="$INSTALL"
	INSTALL_DATA="$INSTALL -m 644"
fi

# Not every filesystem supports hard links
AC_SUBST(LN)
if test -z "$LN" ; then
	case $ac_sys_system in
		BeOS*) LN="ln -s";;
		*) LN=ln;;
	esac
fi

# Optimizer/debugger flags passed between Makefiles
AC_SUBST(OPT)
if test -z "$OPT"
then
	case $GCC in
	yes)
		case $ac_cv_prog_cc_g in
		yes)	OPT="-g -O2 -Wall -Wstrict-prototypes -fPIC";;
		*)	OPT="-O2 -Wall -Wstrict-prototypes -fPIC";;
		esac
		;;
	*)	OPT="-O";;
	esac
fi

# The current (beta) Monterey compiler dies with optimizations
case $ac_sys_system in
Monterey*) OPT="";;
esac

if test "$ac_arch_flags"
then
	OPT="$OPT $ac_arch_flags"
fi
# checks for UNIX variants that set C preprocessor variables
AC_AIX
AC_MINIX

AC_MSG_CHECKING(whether $CC accepts -OPT:Olimit=0)
AC_CACHE_VAL(ac_cv_opt_olimit_ok,
[ac_save_cc="$CC"
CC="$CC -OPT:Olimit=0"
AC_TRY_RUN([int main() { return 0; }],
  ac_cv_opt_olimit_ok=yes,
  ac_cv_opt_olimit_ok=no)
CC="$ac_save_cc"])
AC_MSG_RESULT($ac_cv_opt_olimit_ok)
if test $ac_cv_opt_olimit_ok = yes; then
    case $ac_sys_system in
      Darwin*) OPT="$OPT" ;;
      *) OPT="$OPT -OPT:Olimit=0";;
    esac
else
  AC_MSG_CHECKING(whether $CC accepts -Olimit 1500)
  AC_CACHE_VAL(ac_cv_olimit_ok,
  [ac_save_cc="$CC"
  CC="$CC -Olimit 1500"
  AC_TRY_RUN([int main() { return 0; }],
    ac_cv_olimit_ok=yes,
    ac_cv_olimit_ok=no)
  CC="$ac_save_cc"])
  AC_MSG_RESULT($ac_cv_olimit_ok)
  if test $ac_cv_olimit_ok = yes; then
    OPT="$OPT -Olimit 1500"
  fi
fi

dnl # check for ANSI or K&R ("traditional") preprocessor
dnl AC_MSG_CHECKING(for C preprocessor type)
dnl AC_TRY_COMPILE([
dnl #define spam(name, doc) {#name, &name, #name "() -- " doc}
dnl int foo;
dnl struct {char *name; int *addr; char *doc;} desc = spam(foo, "something");
dnl ], [;], cpp_type=ansi, AC_DEFINE(HAVE_OLD_CPP) cpp_type=traditional)
dnl AC_MSG_RESULT($cpp_type)

# checks for header files
AC_HEADER_STDC
AC_CHECK_HEADERS(dlfcn.h fcntl.h limits.h locale.h ncurses.h poll.h pthread.h \
signal.h stdarg.h stddef.h stdlib.h thread.h unistd.h utime.h \
sys/audioio.h sys/file.h sys/lock.h db_185.h db.h \
sys/param.h sys/select.h sys/socket.h sys/time.h sys/times.h \
sys/un.h sys/utsname.h sys/wait.h pty.h libutil.h \
ndbm.h db1/ndbm.h gdbm/ndbm.h)
AC_HEADER_DIRENT

# checks for typedefs
was_it_defined=no
AC_MSG_CHECKING(for clock_t in time.h)
AC_EGREP_HEADER(clock_t, time.h, was_it_defined=yes, AC_DEFINE(clock_t, long))
AC_MSG_RESULT($was_it_defined)

# Add some code to confdefs.h so that the test for off_t works on SCO
cat >> confdefs.h <<\EOF
#if defined(SCO_DS)
#undef _OFF_T
#endif
EOF

# Type availability checks
AC_TYPE_MODE_T
AC_TYPE_OFF_T
AC_TYPE_PID_T
AC_TYPE_SIGNAL
AC_TYPE_SIZE_T
AC_TYPE_UID_T

# Sizes of various common basic types
AC_CHECK_SIZEOF(int)
AC_CHECK_SIZEOF(long)
AC_CHECK_SIZEOF(void *)
AC_CHECK_SIZEOF(char)
AC_CHECK_SIZEOF(short)
AC_CHECK_SIZEOF(float)
AC_CHECK_SIZEOF(double)
AC_CHECK_SIZEOF(fpos_t)

AC_MSG_CHECKING(for long long support)
have_long_long=no
AC_TRY_COMPILE([], [long long x; x = (long long)0;], AC_DEFINE(HAVE_LONG_LONG) have_long_long=yes)
AC_MSG_RESULT($have_long_long)
if test "$have_long_long" = yes ; then
AC_CHECK_SIZEOF(long long)
fi

AC_MSG_CHECKING(for uintptr_t support)
have_uintptr_t=no
AC_TRY_COMPILE([], [uintptr_t x; x = (uintptr_t)0;], AC_DEFINE(HAVE_UINTPTR_T) have_uintptr_t=yes)
AC_MSG_RESULT($have_uintptr_t)
if test "$have_uintptr_t" = yes ; then
AC_CHECK_SIZEOF(uintptr_t)
fi

# Hmph. AC_CHECK_SIZEOF() doesn't include <sys/types.h>.
AC_MSG_CHECKING(size of off_t)
AC_CACHE_VAL(ac_cv_sizeof_off_t,
[AC_TRY_RUN([#include <stdio.h>
#include <sys/types.h>
main()
{
  FILE *f=fopen("conftestval", "w");
  if (!f) exit(1);
  fprintf(f, "%d\n", sizeof(off_t));
  exit(0);
}], ac_cv_sizeof_off_t=`cat conftestval`, ac_cv_sizeof_off_t=0)
])
AC_MSG_RESULT($ac_cv_sizeof_off_t)
AC_DEFINE_UNQUOTED(SIZEOF_OFF_T, $ac_cv_sizeof_off_t)

AC_MSG_CHECKING(whether to enable large file support)
if test "$have_long_long" = yes -a \
	"$ac_cv_sizeof_off_t" -gt "$ac_cv_sizeof_long" -a \
	"$ac_cv_sizeof_long_long" -ge "$ac_cv_sizeof_off_t"; then
  AC_DEFINE(HAVE_LARGEFILE_SUPPORT)
  AC_MSG_RESULT(yes)
else
  AC_MSG_RESULT(no)
fi

# AC_CHECK_SIZEOF() doesn't include <time.h>.
AC_MSG_CHECKING(size of time_t)
AC_CACHE_VAL(ac_cv_sizeof_time_t,
[AC_TRY_RUN([#include <stdio.h>
#include <time.h>
main()
{
  FILE *f=fopen("conftestval", "w");
  if (!f) exit(1);
  fprintf(f, "%d\n", sizeof(time_t));
  exit(0);
}], ac_cv_sizeof_time_t=`cat conftestval`, ac_cv_sizeof_time_t=0)
])
AC_MSG_RESULT($ac_cv_sizeof_time_t)
AC_DEFINE_UNQUOTED(SIZEOF_TIME_T, $ac_cv_sizeof_time_t)


# if have pthread_t then define SIZEOF_PTHREAD_T
AC_MSG_CHECKING(for pthread_t)
have_pthread_t=no
AC_TRY_COMPILE([#include <pthread.h>], [pthread_t x; x = *(pthread_t*)0;], have_pthread_t=yes)
AC_MSG_RESULT($have_pthread_t)
if test "$have_pthread_t" = yes ; then
  # AC_CHECK_SIZEOF() doesn't include <pthread.h>.
  AC_MSG_CHECKING(size of pthread_t)
  AC_CACHE_VAL(ac_cv_sizeof_pthread_t,
  [AC_TRY_RUN([#include <stdio.h>
  #include <pthread.h>
  main()
  {
    FILE *f=fopen("conftestval", "w");
    if (!f) exit(1);
    fprintf(f, "%d\n", sizeof(pthread_t));
    exit(0);
  }], ac_cv_sizeof_pthread_t=`cat conftestval`, ac_cv_sizeof_pthread_t=0)
  ])
  AC_MSG_RESULT($ac_cv_sizeof_pthread_t)
  AC_DEFINE_UNQUOTED(SIZEOF_PTHREAD_T, $ac_cv_sizeof_pthread_t)
fi


# Minor variations in building a framework between NextStep versions 4 and 5
AC_SUBST(LIBTOOL_CRUFT)
case $ac_sys_system/$ac_sys_release in
  Darwin/*)
    ns_undef_sym='_environ'
    LIBTOOL_CRUFT="-lcc_dynamic -arch_only ppc -U $ns_undef_sym" ;;
  next/4*)
    ns_undef_sym='__environ'
    LIBTOOL_CRUFT="-U $ns_undef_sym" ;;
  next/5*)
    ns_undef_sym='_environ'
    LIBTOOL_CRUFT="-lcc_dynamic -U $ns_undef_sym" ;;
esac

AC_MSG_CHECKING(for --with-next-framework)
if test "$with_next_framework"
then
	OPT="$OPT -fno-common"
	# -U __environ is needed since bundles don't have access
	# to crt0 when built but will always be linked against it
	LDFLAGS="$LDFLAGS -Wl,-U,$ns_undef_sym"
	AC_DEFINE(WITH_NEXT_FRAMEWORK)
	AC_MSG_RESULT(yes)
else
	AC_MSG_RESULT(no)
fi

AC_MSG_CHECKING(for --with-dyld)
if test "$with_next_framework" -o "$with_dyld"
then
	if test "$with_dyld"
	then
		AC_MSG_RESULT(yes)
	else
		AC_MSG_RESULT(required for framework build)
	fi
	AC_DEFINE(WITH_DYLD)
	ns_dyld='set'
else
	AC_MSG_RESULT(no)
fi

# Set info about shared libraries.
AC_SUBST(SO)
AC_SUBST(LDSHARED)
AC_SUBST(CCSHARED)
AC_SUBST(LINKFORSHARED)
# SO is the extension of shared libraries `(including the dot!)
# -- usually .so, .sl on HP-UX
AC_MSG_CHECKING(SO)
if test -z "$SO"
then
	case $ac_sys_system in
	hp*|HP*)   SO=.sl;;
	*)	   SO=.so;;
	esac
fi
AC_MSG_RESULT($SO)
# LDSHARED is the ld *command* used to create shared library
# -- "ld" on SunOS 4.x.x, "ld -G" on SunOS 5.x, "ld -shared" on IRIX 5
# (Shared libraries in this instance are shared modules to be loaded into
# Python, as opposed to building Python itself as a shared library.)
AC_MSG_CHECKING(LDSHARED)
if test -z "$LDSHARED"
then
	case $ac_sys_system/$ac_sys_release in
	AIX*) LDSHARED="\$(srcdir)/ld_so_aix \$(CC)";;
	BeOS*) LDSHARED="\$(srcdir)/../BeOS/linkmodule -L.. -lpython\$(VERSION)";;
	IRIX/5*) LDSHARED="ld -shared";;
	IRIX*/6*) LDSHARED="ld ${SGI_ABI} -shared -all";;
	SunOS/4*) LDSHARED="ld";;
	SunOS/5*) 
		if test "$GCC" = "yes"
		then LDSHARED='$(CC) -shared'
		else LDSHARED="ld -G";
		fi ;;
	hp*|HP*) LDSHARED="ld -b";;
	OSF*) LDSHARED="ld -shared -expect_unresolved \"*\"";;
	DYNIX/ptx*) LDSHARED="ld -G";;
        Darwin/*|next/*) 
		if test "$ns_dyld"
		then 
		  if test "$ac_sys_system" = Darwin
		  then LDSHARED='$(CC) $(LDFLAGS) -bundle -undefined suppress'
		  else LDSHARED='$(CC) $(LDFLAGS) -bundle -prebind'
		  fi
		else LDSHARED='$(CC) $(CFLAGS) -nostdlib -r';
		fi
	if test "$with_next_framework" ; then
		    LDSHARED="$LDSHARED \$(LDLIBRARY)"
		fi ;;
	Linux*) LDSHARED="gcc -shared";;
	dgux*) LDSHARED="ld -G";;
	BSD/OS*/4*) LDSHARED="gcc -shared";;
	OpenBSD*) LDSHARED="ld -Bshareable";;
	NetBSD*)
		if [[ "`$CC -dM -E - </dev/null | grep __ELF__`" != "" ]]
		then
			LDSHARED="cc -shared"
		else
			LDSHARED="ld -Bshareable"
		fi;;
	FreeBSD*)
		if [[ "`$CC -dM -E - </dev/null | grep __ELF__`" != "" ]]
		then
			LDSHARED="cc -shared ${LDFLAGS}"
		else
			LDSHARED="ld -Bshareable ${LDFLAGS}"
		fi;;
	SCO_SV*) LDSHARED="cc -G -KPIC -Ki486 -belf -Wl,-Bexport";;
	Monterey*) LDSHARED="cc -G -dy -Bdynamic -Bexport -L/usr/lib/ia64l64";;
	*)	LDSHARED="ld";;
	esac
fi
AC_MSG_RESULT($LDSHARED)
# CCSHARED are the C *flags* used to create objects to go into a shared
# library (module) -- this is only needed for a few systems
AC_MSG_CHECKING(CCSHARED)
if test -z "$CCSHARED"
then
	case $ac_sys_system/$ac_sys_release in
	hp*|HP*) if test "$GCC" = yes;
		 then CCSHARED="-fpic";
		 else CCSHARED="+z";
		 fi;;
	Linux*) CCSHARED="-fpic";;
	BSD/OS*/4*) CCSHARED="-fpic";;
	OpenBSD*) CCSHARED="-fpic";;
	FreeBSD*|NetBSD*) CCSHARED="-fPIC";;
	SCO_SV*) CCSHARED="-KPIC -dy -Bdynamic";;
	Monterey*) CCSHARED="-G";;
	IRIX*/6*)  case $CC in
		   *gcc*) CCSHARED="-shared";;
		   *) CCSHARED="";;
		   esac;;
	esac
fi
AC_MSG_RESULT($CCSHARED)
# LINKFORSHARED are the flags passed to the $(CC) command that links
# the python executable -- this is only needed for a few systems
AC_MSG_CHECKING(LINKFORSHARED)
if test -z "$LINKFORSHARED"
then
	case $ac_sys_system/$ac_sys_release in
	AIX*)	LINKFORSHARED='-Wl,-bE:python.exp -lld';;
	hp*|HP*)
	    LINKFORSHARED="-Wl,-E -Wl,+s -Wl,+b\$(BINLIBDEST)/lib-dynload";;
	BSD/OS/4*) LINKFORSHARED="-Xlinker -export-dynamic";;
	Linux*) LINKFORSHARED="-Xlinker -export-dynamic";;
	# -u libsys_s pulls in all symbols in libsys
	next/2*|next/3*) LINKFORSHARED="-u libsys_s";;
	# -u __dummy makes the linker aware of the objc runtime
	# in System.framework; otherwise, __objcInit (referenced in
	# crt1.o) gets erroneously defined as common, which breaks dynamic
	# loading of any modules which reference it in System.framework
	next/4*|next/5*) LINKFORSHARED="-u __dummy -framework System" ;;
	Darwin/*) LINKFORSHARED="-framework System" ;;
	SCO_SV*) LINKFORSHARED="-Bdynamic -dy -Wl,-Bexport";;
	ReliantUNIX*) LINKFORSHARED="-W1 -Blargedynsym";;
	FreeBSD*|NetBSD*) 
		if [[ "`$CC -dM -E - </dev/null | grep __ELF__`" != "" ]]
		then
			LINKFORSHARED="-Wl,--export-dynamic"
		fi;;
	SunOS/5*) case $CC in
		  *gcc*)
		    if $CC -Xlinker -V 2>&1 | grep BFD >/dev/null
		    then
			LINKFORSHARED="-Xlinker --export-dynamic"
		    fi;;
		  esac;;
	esac
fi
AC_MSG_RESULT($LINKFORSHARED)

# checks for libraries
AC_CHECK_LIB(dl, dlopen)	# Dynamic linking for SunOS/Solaris and SYSV
AC_CHECK_LIB(dld, shl_load)	# Dynamic linking for HP-UX

# Check for --with-pydebug
AC_MSG_CHECKING(for --with-pydebug)
AC_ARG_WITH(pydebug, 
[  --with-pydebug                  build with Py_DEBUG defined], [
if test "$withval" != no
then AC_DEFINE(Py_DEBUG) AC_MSG_RESULT(yes)
else AC_MSG_RESULT(no)
fi],
[AC_MSG_RESULT(no)])

# checks for system dependent C++ extensions support
case "$ac_sys_system" in
	AIX*)	AC_MSG_CHECKING(for genuine AIX C++ extensions support)
		AC_TRY_LINK([#include "/usr/lpp/xlC/include/load.h"],
			    [loadAndInit("", 0, "")],
			    [AC_DEFINE(AIX_GENUINE_CPLUSPLUS)
			     AC_MSG_RESULT(yes)],
			    [AC_MSG_RESULT(no)]);;
	*) ;;
esac

# Most SVR4 platforms (e.g. Solaris) need -lsocket and -lnsl.
# However on SGI IRIX, these exist but are broken.
# BeOS' sockets are stashed in libnet.
case "$ac_sys_system" in
IRIX*) ;;
*)
AC_CHECK_LIB(nsl, t_open, [LIBS="-lnsl $LIBS"]) # SVR4
AC_CHECK_LIB(socket, socket, [LIBS="-lsocket $LIBS"], [], $LIBS) # SVR4 sockets
;;
esac
case "$ac_sys_system" in
BeOS*)
AC_CHECK_LIB(net, socket, [LIBS="-lnet $LIBS"], [], $LIBS) # BeOS
;;
esac

AC_MSG_CHECKING(for --with-libs)
AC_ARG_WITH(libs,
[  --with-libs='lib1 ...'          link against additional libs], [
AC_MSG_RESULT($withval)
LIBS="$withval $LIBS"
], AC_MSG_RESULT(no))

AC_SUBST(USE_THREAD_MODULE)
USE_THREAD_MODULE=""

AC_MSG_CHECKING(for --with-dec-threads)
AC_SUBST(LDLAST)
AC_ARG_WITH(dec-threads,
[  --with-dec-threads              use DEC Alpha/OSF1 thread-safe libraries], [
AC_MSG_RESULT($withval)
LDLAST=-threads
if test "${with_thread+set}" != set; then
   with_thread="$withval";
fi],
AC_MSG_RESULT(no))

AC_MSG_CHECKING(for --with-threads)
AC_ARG_WITH(threads,
[  --with(out)-threads[=DIRECTORY] disable/enable thread support])

# --with-thread is deprecated, but check for it anyway
AC_ARG_WITH(thread,
[  --with(out)-thread[=DIRECTORY]  deprecated; use --with(out)-threads],[
with_threads=$with_thread])

if test -z "$with_threads"
then with_threads="yes"
fi
AC_MSG_RESULT($with_threads)

if test "$with_threads" = "no"
then
    USE_THREAD_MODULE="#"
else
    if test ! -z "$with_threads" -a -d "$with_threads"
    then LDFLAGS="$LDFLAGS -L$with_threads"
    fi
    if test ! -z "$withval" -a -d "$withval"
    then LDFLAGS="$LDFLAGS -L$withval"
    fi
    AC_DEFINE(_REENTRANT)
    AC_CHECK_HEADER(mach/cthreads.h, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(C_THREADS)
    LIBOBJS="$LIBOBJS thread.o"],[
    AC_MSG_CHECKING(for --with-pth)
    AC_ARG_WITH(pth,
    [  --with-pth                      use GNU pth threading libraries], [
    AC_MSG_RESULT($withval)
    AC_DEFINE(WITH_THREAD)
    AC_DEFINE(HAVE_PTH)
    LIBS="-lpth $LIBS"
    LIBOBJS="$LIBOBJS thread.o"],[
    AC_MSG_RESULT(no)
    AC_CHECK_LIB(pthread, pthread_create, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="-lpthread $LIBS"
    LIBOBJS="$LIBOBJS thread.o"],[
    AC_CHECK_FUNC(pthread_detach, [AC_DEFINE(WITH_THREAD)
    case $ac_sys_system in
      Darwin*) ;;
      *) AC_DEFINE(_POSIX_THREADS);;
    esac
    LIBOBJS="$LIBOBJS thread.o"],[
    AC_CHECK_HEADER(kernel/OS.h, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(BEOS_THREADS)
    LIBOBJS="$LIBOBJS thread.o"],[
    AC_CHECK_LIB(pthreads, pthread_create, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="$LIBS -lpthreads"
    LIBOBJS="$LIBOBJS thread.o"], [
    AC_CHECK_LIB(c_r, pthread_create, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="$LIBS -lc_r"
    LIBOBJS="$LIBOBJS thread.o"], [
    AC_CHECK_LIB(thread, __d6_pthread_create, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="$LIBS -lthread"
    LIBOBJS="$LIBOBJS thread.o"], [
    AC_CHECK_LIB(pthread, __pthread_create_system, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="$LIBS -lpthread"
    LIBOBJS="$LIBOBJS thread.o"], [
    AC_CHECK_LIB(cma, pthread_create, [AC_DEFINE(WITH_THREAD)
    AC_DEFINE(_POSIX_THREADS)
    LIBS="$LIBS -lcma"
    LIBOBJS="$LIBOBJS thread.o"],[
    USE_THREAD_MODULE="#"])
    ])])])])])])])])])

    AC_CHECK_LIB(mpc, usconfig, [AC_DEFINE(WITH_THREAD)
    LIBS="$LIBS -lmpc"
    LIBOBJS="$LIBOBJS thread.o"
    USE_THREAD_MODULE=""])
    AC_CHECK_LIB(thread, thr_create, [AC_DEFINE(WITH_THREAD)
    LIBS="$LIBS -lthread"
    LIBOBJS="$LIBOBJS thread.o"
    USE_THREAD_MODULE=""])

    if test "$USE_THREAD_MODULE" != "#"
    then
        # If the above checks didn't disable threads, (at least) OSF1
        # needs this '-threads' argument during linking.
        case $ac_sys_system in
        OSF1) LDLAST=-threads;;
        esac
    fi
fi

# Check for GC support
AC_SUBST(USE_GC_MODULE)
USE_GC_MODULE=""
AC_MSG_CHECKING(for --with-cycle-gc)
AC_ARG_WITH(cycle-gc,
[  --with(out)-cycle-gc            disable/enable garbage collection])

if test -z "$with_cycle_gc"
then with_cycle_gc="yes"
fi
if test "$with_cycle_gc" = "no"
then
    USE_GC_MODULE="#"
else
    AC_DEFINE(WITH_CYCLE_GC)
fi
AC_MSG_RESULT($with_cycle_gc)

# Check for LIBDB support
# either --with-libdb or, in its absence, the presence of db.h
AC_SUBST(USE_BSDDB_MODULE)
USE_BSDDB_MODULE=""
AC_MSG_CHECKING(for --with-libdb)
AC_ARG_WITH(libdb,
[  --with(out)-libdb               disable/enable bsddb module])

# enabled by default, but db.h must be found
if test "$ac_cv_header_db_h" = "yes"
then
    if test "$with_libdb" != "no"
    then with_libdb="yes"
    fi
else
    # make sure user knows why bsddb support wasn't enabled even
    # though s/he requested it
    if test "$with_libdb" = "yes"
    then echo $ac_n "(requested, but db.h was not found) $ac_c"
    fi
    with_libdb="no"
fi

if test "$with_libdb" = "no"
then
    USE_BSDDB_MODULE="#"
else
    AC_DEFINE(WITH_LIBDB)
fi
AC_MSG_RESULT($with_libdb)

if test "$with_libdb" = "yes"
then
    # check for libdb; BSD systems have the DB routines in libc  --tg
    AC_SUBST(HAVE_LIBDB)
    # If dbopen is not in libc, then checking whether it is in libdb
    # is difficult: db_185.h may #define it as __db185_open
    # Instead, we just trust it is in libdb; linking will fail if it
    # is not.
    AC_CHECK_FUNC(dbopen, [HAVE_LIBDB=], [HAVE_LIBDB=-ldb])
fi

# Check for --with-wctype-functions
AC_MSG_CHECKING(for --with-wctype-functions)
AC_ARG_WITH(wctype-functions, 
[  --with-wctype-functions         use wctype.h functions], [
if test "$withval" != no
then AC_DEFINE(WANT_WCTYPE_FUNCTIONS) AC_MSG_RESULT(yes)
else AC_MSG_RESULT(no)
fi],
[AC_MSG_RESULT(no)])

# -I${DLINCLDIR} is added to the compile rule for importdl.o
AC_SUBST(DLINCLDIR)
DLINCLDIR=/

AC_MSG_CHECKING(for --with-sgi-dl)
AC_ARG_WITH(sgi-dl,
[  --with-sgi-dl=DIRECTORY         IRIX 4 dynamic linking], [
AC_MSG_RESULT($withval)
AC_DEFINE(WITH_SGI_DL)
DYNLOADFILE="dynload_dl.o"
dldir=$withval
if test ! -z "$dldir" -a -d "$dldir"
then LDFLAGS="$LDFLAGS -L$dldir"
else AC_ERROR(proper usage is --with-sgi-dl=DIRECTORY)
fi
DLINCLDIR=${dldir}
LIBS="$LIBS -ldl -lmld"], AC_MSG_RESULT(no))

AC_MSG_CHECKING(for --with-dl-dld)
AC_ARG_WITH(dl-dld, [  --with-dl-dld=DL_DIR,DLD_DIR    GNU dynamic linking], [
AC_MSG_RESULT($withval)
AC_DEFINE(WITH_DL_DLD)
DYNLOADFILE="dynload_dl.o"
dldir=`echo "$withval" | sed 's/,.*//'`
dlddir=`echo "$withval" | sed 's/.*,//'`
if test ! -z "$dldir" -a -d "$dldir" -a ! -z "$dlddir" -a -d "$dlddir"
then LDFLAGS="$LDFLAGS -L$dldir -L$dlddir"
else AC_ERROR(proper usage is --with-dl-dld=DL_DIRECTORY,DLD_DIRECTORY)
fi
DLINCLDIR=${dldir}
LIBS="$LIBS -ldl -ldld"], AC_MSG_RESULT(no))

# the dlopen() function means we might want to use dynload_shlib.o. some
# platforms, such as AIX, have dlopen(), but don't want to use it.
AC_CHECK_FUNCS(dlopen)

# DYNLOADFILE specifies which dynload_*.o file we will use for dynamic
# loading of modules.
AC_SUBST(DYNLOADFILE)
AC_MSG_CHECKING(DYNLOADFILE)
if test -z "$DYNLOADFILE"
then
	case $ac_sys_system/$ac_sys_release in
	AIX*) DYNLOADFILE="dynload_aix.o";;
	BeOS*) DYNLOADFILE="dynload_beos.o";;
	hp*|HP*) DYNLOADFILE="dynload_hpux.o";;
	Darwin/*|next/*) DYNLOADFILE="dynload_next.o";;
	*)
	# use dynload_shlib.c and dlopen() if we have it; otherwise stub
	# out any dynamic loading
	if test "$ac_cv_func_dlopen" = yes
	then DYNLOADFILE="dynload_shlib.o"
	else DYNLOADFILE="dynload_stub.o"
	fi
	;;
	esac
fi
AC_MSG_RESULT($DYNLOADFILE)
if test "$DYNLOADFILE" != "dynload_stub.o"
then
	AC_DEFINE(HAVE_DYNAMIC_LOADING)
fi

# checks for library functions
AC_CHECK_FUNCS(alarm chown clock confstr ctermid ctermid_r execv \
 flock fork fsync fdatasync fpathconf ftime ftruncate \
 getgroups getline getlogin getpeername getpid getpwent getwd \
 kill link lstat mkfifo mktime mremap \
 nice pathconf pause plock poll pthread_init \
 putenv readlink \
 select setegid seteuid setgid \
 setlocale setregid setreuid setsid setpgid setuid setvbuf \
 sigaction siginterrupt sigrelse strftime strptime symlink sysconf \
 tcgetpgrp tcsetpgrp tempnam timegm times tmpfile tmpnam tmpnam_r \
 truncate uname waitpid _getpty)

# check for openpty and forkpty

AC_CHECK_FUNCS(openpty,, AC_CHECK_LIB(util,openpty, [AC_DEFINE(HAVE_OPENPTY)] [LIBS="$LIBS -lutil"]))
AC_CHECK_FUNCS(forkpty,, AC_CHECK_LIB(util,forkpty, [AC_DEFINE(HAVE_FORKPTY)] [LIBS="$LIBS -lutil"]))

# check for long file support functions
AC_CHECK_FUNCS(fseek64 fseeko fstatvfs ftell64 ftello statvfs)

AC_REPLACE_FUNCS(dup2 getcwd strdup strerror memmove)
AC_CHECK_FUNCS(getpgrp, AC_TRY_COMPILE([#include <unistd.h>], [getpgrp(0);], AC_DEFINE(GETPGRP_HAVE_ARG)))
AC_CHECK_FUNCS(setpgrp, AC_TRY_COMPILE([#include <unistd.h>], [setpgrp(0,0);], AC_DEFINE(SETPGRP_HAVE_ARG)))
AC_CHECK_FUNCS(gettimeofday, AC_TRY_COMPILE([#include <sys/time.h>], [gettimeofday((struct timeval*)0,(struct timezone*)0);], ,AC_DEFINE(GETTIMEOFDAY_NO_TZ)))

# checks for structures
AC_HEADER_TIME
AC_STRUCT_TM
AC_STRUCT_TIMEZONE

AC_MSG_CHECKING(for time.h that defines altzone)
AC_CACHE_VAL(ac_cv_header_time_altzone,
[AC_TRY_COMPILE([#include <time.h>], [return altzone;],
  ac_cv_header_time_altzone=yes,
  ac_cv_header_time_altzone=no)])
AC_MSG_RESULT($ac_cv_header_time_altzone)
if test $ac_cv_header_time_altzone = yes; then
  AC_DEFINE(HAVE_ALTZONE)
fi

was_it_defined=no
AC_MSG_CHECKING(whether sys/select.h and sys/time.h may both be included)
AC_TRY_COMPILE([
#include <sys/types.h>
#include <sys/select.h>
#include <sys/time.h>
], [;], [AC_DEFINE(SYS_SELECT_WITH_SYS_TIME) was_it_defined=yes])
AC_MSG_RESULT($was_it_defined)

# checks for compiler characteristics

AC_C_CHAR_UNSIGNED
AC_C_CONST

works=no
AC_MSG_CHECKING(for working volatile)
AC_TRY_COMPILE([],[volatile int x; x = 0;], works=yes, AC_DEFINE(volatile, []))
AC_MSG_RESULT($works)

works=no
AC_MSG_CHECKING(for working signed char)
AC_TRY_COMPILE([], [signed char c;], works=yes, AC_DEFINE(signed, []))
AC_MSG_RESULT($works)

have_prototypes=no
AC_MSG_CHECKING(for prototypes)
AC_TRY_COMPILE([int foo(int x) { return 0; }], [return foo(10);],
AC_DEFINE(HAVE_PROTOTYPES) have_prototypes=yes)
AC_MSG_RESULT($have_prototypes)

works=no
AC_MSG_CHECKING(for variable length prototypes and stdarg.h)
AC_TRY_COMPILE([
#include <stdarg.h>
int foo(int x, ...) {
	va_list va;
	va_start(va, x);
	va_arg(va, int);
	va_arg(va, char *);
	va_arg(va, double);
	return 0;
}
], [return foo(10, "", 3.14);],
AC_DEFINE(HAVE_STDARG_PROTOTYPES) works=yes)
AC_MSG_RESULT($works)

if test "$have_prototypes" = yes; then
bad_prototypes=no
AC_MSG_CHECKING(for bad exec* prototypes)
AC_TRY_COMPILE([#include <unistd.h>], [char **t;execve("@",t,t);], ,
	AC_DEFINE(BAD_EXEC_PROTOTYPES) bad_prototypes=yes)
AC_MSG_RESULT($bad_prototypes)
fi

bad_forward=no
AC_MSG_CHECKING(for bad static forward)
AC_TRY_RUN([
struct s { int a; int b; };
static struct s foo;
int foobar() {
 static int random;
 random = (int) &foo;
 return random;
}
static struct s foo = { 1, 2 };
main() {
 exit(!((int)&foo == foobar()));
}
], , AC_DEFINE(BAD_STATIC_FORWARD) bad_forward=yes)
AC_MSG_RESULT($bad_forward)

va_list_is_array=no
AC_MSG_CHECKING(whether va_list is an array)
AC_TRY_COMPILE([
#ifdef HAVE_STDARG_PROTOTYPES
#include <stdarg.h>
#else
#include <varargs.h>
#endif
], [va_list list1, list2; list1 = list2;], , 
AC_DEFINE(VA_LIST_IS_ARRAY) va_list_is_array=yes)
AC_MSG_RESULT($va_list_is_array)

# sigh -- gethostbyname_r is a mess; it can have 3, 5 or 6 arguments :-(
AC_CHECK_FUNC(gethostbyname_r, [
  AC_DEFINE(HAVE_GETHOSTBYNAME_R)
  AC_MSG_CHECKING([gethostbyname_r with 6 args])
  OLD_CFLAGS=$CFLAGS
  CFLAGS="$CFLAGS $MY_CPPFLAGS $MY_THREAD_CPPFLAGS $MY_CFLAGS"
  AC_TRY_COMPILE([
#   include <netdb.h>
  ], [
    char *name;
    struct hostent *he, *res;
    char buffer[2048];
    int buflen = 2048;
    int h_errnop;

    (void) gethostbyname_r(name, he, buffer, buflen, &res, &h_errnop)
  ], [
    AC_DEFINE(HAVE_GETHOSTBYNAME_R)
    AC_DEFINE(HAVE_GETHOSTBYNAME_R_6_ARG)
    AC_MSG_RESULT(yes)
  ], [
    AC_MSG_RESULT(no)
    AC_MSG_CHECKING([gethostbyname_r with 5 args])
    AC_TRY_COMPILE([
#     include <netdb.h>
    ], [
      char *name;
      struct hostent *he;
      char buffer[2048];
      int buflen = 2048;
      int h_errnop;

      (void) gethostbyname_r(name, he, buffer, buflen, &h_errnop)
    ], [
      AC_DEFINE(HAVE_GETHOSTBYNAME_R)
      AC_DEFINE(HAVE_GETHOSTBYNAME_R_5_ARG)
      AC_MSG_RESULT(yes)
    ], [
      AC_MSG_RESULT(no)
      AC_MSG_CHECKING([gethostbyname_r with 3 args])
      AC_TRY_COMPILE([
#       include <netdb.h>
      ], [
        char *name;
        struct hostent *he;
        struct hostent_data data;

        (void) gethostbyname_r(name, he, &data);
      ], [
        AC_DEFINE(HAVE_GETHOSTBYNAME_R)
        AC_DEFINE(HAVE_GETHOSTBYNAME_R_3_ARG)
        AC_MSG_RESULT(yes)
      ], [
        AC_MSG_RESULT(no)
      ])
    ])
  ])
  CFLAGS=$OLD_CFLAGS
], [
  AC_CHECK_FUNCS(gethostbyname)
])
AC_SUBST(HAVE_GETHOSTBYNAME_R_6_ARG)
AC_SUBST(HAVE_GETHOSTBYNAME_R_5_ARG)
AC_SUBST(HAVE_GETHOSTBYNAME_R_3_ARG)
AC_SUBST(HAVE_GETHOSTBYNAME_R)
AC_SUBST(HAVE_GETHOSTBYNAME)

# checks for system services
# (none yet)

# Linux requires this for correct f.p. operations
AC_CHECK_FUNC(__fpu_control,
  [],
  [AC_CHECK_LIB(ieee, __fpu_control)
])

# Check for --with-fpectl
AC_MSG_CHECKING(for --with-fpectl)
AC_ARG_WITH(fpectl,
[  --with-fpectl                   enable SIGFPE catching], [
if test "$withval" != no
then AC_DEFINE(WANT_SIGFPE_HANDLER) AC_MSG_RESULT(yes)
else AC_MSG_RESULT(no)
fi],
[AC_MSG_RESULT(no)])

# check for --with-libm=...
AC_SUBST(LIBM)
case $ac_sys_system in
Darwin) ;;
next) ;;
BeOS) ;;
*) LIBM=-lm
esac
AC_MSG_CHECKING(for --with-libm=STRING)
AC_ARG_WITH(libm, [  --with-libm=STRING              math library], [
if test "$withval" = no
then LIBM=
     AC_MSG_RESULT(force LIBM empty)
elif test "$withval" != yes
then LIBM=$withval
     AC_MSG_RESULT(set LIBM=\"$withval\")
else AC_ERROR(proper usage is --with-libm=STRING)
fi],
[AC_MSG_RESULT(default LIBM=\"$LIBM\")])

# check for --with-libc=...
AC_SUBST(LIBC)
AC_MSG_CHECKING(for --with-libc=STRING)
AC_ARG_WITH(libc, [  --with-libc=STRING              C library], [
if test "$withval" = no
then LIBC=
     AC_MSG_RESULT(force LIBC empty)
elif test "$withval" != yes
then LIBC=$withval
     AC_MSG_RESULT(set LIBC=\"$withval\")
else AC_ERROR(proper usage is --with-libc=STRING)
fi],
[AC_MSG_RESULT(default LIBC=\"$LIBC\")])

# check for hypot() in math library
LIBS_SAVE=$LIBS
LIBS="$LIBS $LIBM"
AC_REPLACE_FUNCS(hypot)
LIBS=$LIBS_SAVE

# check whether malloc(0) returns NULL or not
AC_MSG_CHECKING(what malloc(0) returns)
AC_CACHE_VAL(ac_cv_malloc_zero,
[AC_TRY_RUN([#include <stdio.h>
#ifdef HAVE_STDLIB
#include <stdlib.h>
#else
char *malloc(), *realloc();
int *free();
#endif
main() {
	char *p;
	p = malloc(0);
	if (p == NULL) exit(1);
	p = realloc(p, 0);
	if (p == NULL) exit(1);
	free(p);
	exit(0);
}], ac_cv_malloc_zero=nonnull, ac_cv_malloc_zero=null)])
AC_MSG_RESULT($ac_cv_malloc_zero)
if test "$ac_cv_malloc_zero" = null
then
  AC_DEFINE(MALLOC_ZERO_RETURNS_NULL)
fi

# check for wchar.h
AC_CHECK_HEADER(wchar.h,
AC_DEFINE(HAVE_WCHAR_H) wchar_h="yes",
wchar_h="no"
)

# check for usable wchar_t
usable_wchar_t="unkown"
AC_MSG_CHECKING(for usable wchar_t)
AC_TRY_RUN([
#include "wchar.h"
#include "wctype.h"
main() {
 wchar_t s;
 if (sizeof(s) == 2)
  exit(0);
 else
  exit(1);
}
], 
AC_DEFINE(HAVE_USABLE_WCHAR_T) usable_wchar_t="yes",
usable_wchar_t="no")
AC_MSG_RESULT($usable_wchar_t)

# check for endianness
AC_C_BIGENDIAN

# Check whether right shifting a negative integer extends the sign bit
# or fills with zeros (like the Cray J90, according to Tim Peters).
AC_MSG_CHECKING(whether right shift extends the sign bit)
AC_CACHE_VAL(ac_cv_rshift_extends_sign, [
AC_TRY_RUN([
int main()
{
	exit(((-1)>>3 == -1) ? 0 : 1);
}
], ac_cv_rshift_extends_sign=yes, ac_cv_rshift_extends_sign=no)])
AC_MSG_RESULT($ac_cv_rshift_extends_sign)
if test "$ac_cv_rshift_extends_sign" = no
then
  AC_DEFINE(SIGNED_RIGHT_SHIFT_ZERO_FILLS)
fi


# THIS MUST BE LAST, IT CAN BREAK OTHER TESTS!
# Add sys/socket.h to confdefs.h
cat >> confdefs.h <<\EOF
#ifdef HAVE_SYS_SOCKET_H
#include <sys/socket.h>
#endif
EOF
AC_CHECK_TYPE(socklen_t, int)

AC_MSG_CHECKING(for Modules/Setup)
if test ! -f Modules/Setup ; then
    if test ! -d Modules ; then
        mkdir Modules
    fi
    cp "$srcdir/Modules/Setup.dist" Modules/Setup
    AC_MSG_RESULT(creating)
else
    AC_MSG_RESULT(already exists)
fi

# generate output files
AC_OUTPUT(Makefile \
 Objects/Makefile \
 Parser/Makefile \
 Grammar/Makefile \
 Python/Makefile \
 Modules/Makefile.pre \
 Modules/Setup.config)