dnl Process this file with autoconf to produce a configure script.
AC_INIT(engine.c)

AC_ARG_ENABLE(force-reg,
[  --enable-force-reg	  Use explicit register declarations if they appear in
			  the machine.h file. This can cause a good speedup,
			  but also incorrect code with some gcc versions on
			  some processors (default disabled).],

AC_DEFINE(FORCE_REG))
dnl this is not quite according to the autoconf manual, it causes a replacement
AC_ARG_ENABLE(direct-threaded,
[  --enable-direct-threaded	Force direct threading. This may not work on
				some machines and may cause slowdown on others.
				(default processor-dependent)],
AC_DEFINE(DIRECT_THREADED))
AC_ARG_ENABLE(indirect-threaded,
[  --enable-indirect-threaded	Force indirect threading. This can cause a
				slowdown on some machines.
				(default processor-dependent)],
AC_DEFINE(INDIRECT_THREADED))

AC_ARG_WITH(debug,
[  --with-debug     specifies option -g to compile with debug info (default)
   --without-debug  omits the -g switch and creates smaller images on
                    machines where "strip" has problems with gcc style
                    debugging informations.],
if test "$withval" = "yes"; then DEBUGFLAG=-g; fi)

AC_PROG_CC

if test "$GCC" = "yes"
then
   echo "Fine, gcc is available"
else
   cat <<'EOF'
Gforth uses the GNU-C extensions for better performance. It does not work
with other C compilers. Please install a new version of the GNU-C compiler, and
try again.
EOF
   exit 1
fi

AC_SUBST(CC)
AC_SUBST(GCCLDFLAGS)
AC_SUBST(DEBUGFLAG)

dnl the following macro produces a warning with autoconf-2.1
AC_CHECK_SIZEOF(char *)
case "$ac_cv_sizeof_char_p" in
  2)
    wordsize=16
    ;;
  4)
    wordsize=32
    ;;
  8)
    wordsize=64
dnl    AC_CHECK_SIZEOF(long long)
dnl    if [ $ac_cv_sizeof_long_long != 16 ]
dnl    then
dnl       try the whole thing with -mlonglong128
dnl complain about C compiler and OS vendor
dnl    fi
    ;;
esac

#terminology is a bit unusual here: The host is the system on which
#gforth will run; the system on which configure will run is the `build'
AC_CANONICAL_HOST
case "$host_cpu" in
	hppa*)
		mach_h=hppa
		LIBOBJS="cache.o"
		LDFLAGS="-Xlinker -N"
		LIBS="-L/lib/pa1.1/"
		;;
	sparc*)
		mach_h=sparc
		;;
	i386|i486|i586)
		mach_h=386
		CFLAGS="-fomit-frame-pointer -fforce-addr -fforce-mem"
		#!! direct/indirect threading switch
		#!! -m486 flag
		;;
	m68*)
		mach_h=m68k
		;;
	mips*)
		mach_h=mips
		#link text and data segment into the same 256M region!
		GCCLDFLAGS="-Xlinker -T -Xlinker 10000000 -Xlinker -D -Xlinker 10400000"
		;;
	alpha*)
		mach_h=alpha
		echo Very Preliminary Support for Alpha!!!
		;;
	*)
		echo "No direct threading support for $host_cpu, using indirect threading."
		echo "Using a generic 32-bit machine description. It will only work if char * AND"
		echo "long values have 32 bits."
		echo "I'll assume that C floats and doubles are represented by IEEE single and"
		echo "double numbers. If this is not so, SF@ etc. will not work correctly."
		mach_h=32bit
esac
AC_SUBST(host)
AC_SUBST(ENGINE_FLAGS)

dnl Now a little support for DOS/DJGCC
AC_SUBST(MAKE_EXE)
MAKE_EXE=""

dnl copy commands for systems that don't have links
AC_SUBST(LINK_KERNL16L)
LINK_KERNL16L=""
AC_SUBST(LINK_KERNL16B)
LINK_KERNL16B=""
AC_SUBST(LINK_KERNL32L)
LINK_KERNL32L=""
AC_SUBST(LINK_KERNL32B)
LINK_KERNL32B=""
AC_SUBST(LINK_KERNL64L)
LINK_KERNL64L=""
AC_SUBST(LINK_KERNL64B)
LINK_KERNL64B=""

#if test $host_os=dos
#then
#  echo Configuring for DOS!!!
#  MAKE_EXE="coff2exe gforth"
#  LINK_KERNL32L='$(CP) kernl32l.fi kernal.fi'
#fi

dnl the following macro produces a warning with autoconf-2.1
AC_C_BIGENDIAN
AC_SUBST(KERNAL)
dnl ac_cv_c_bigendian is an undocumented variable of autoconf-2.1
if test $ac_cv_c_bigendian = yes; then
  bytesex=b
  KERNAL="kernl16b.fi kernl16l.fi kernl32b.fi kernl32l.fi kernl64b.fi kernl64l.fi"
else
  bytesex=l
  KERNAL="kernl16l.fi kernl16b.fi kernl32l.fi kernl32b.fi kernl64l.fi kernl64b.fi"
fi

dnl Checks for programs.
AC_PROG_LN_S
AC_PROG_INSTALL

dnl Checks for library functions
dnl This check is just for making later checks link with libm.
dnl using sin here is no good idea since it is built-into gcc and typechecked
AC_CHECK_LIB(m,asin)
AC_FUNC_MEMCMP
AC_REPLACE_FUNCS(memmove strtoul pow10 strerror strsignal)
AC_CHECK_FUNC(getopt_long,getopt_long="",getopt_long="getopt.o getopt1.o")
AC_SUBST(getopt_long)
AC_CHECK_FUNCS(rint expm1 log1p)
AC_REPLACE_FUNCS(ecvt)
dnl No check for select, because our replacement is no good under
dnl anything but DOS

kernal_fi=kernl${wordsize}${bytesex}.fi
AC_SUBST(kernal_fi)

AC_LINK_FILES(${mach_h}.h $kernal_fi,machine.h kernal.fi)
AC_OUTPUT(Makefile)