macemu/SheepShaver/src/Unix/configure.in

dnl Process this file with autoconf to produce a configure script.
dnl Written in 2002 by Christian Bauer

AC_INIT(main_unix.cpp)
AC_PREREQ(2.12)
AC_CONFIG_HEADER(config.h)

dnl Canonical system information.
AC_CANONICAL_HOST
AC_CANONICAL_TARGET

dnl Options.
AC_ARG_ENABLE(jit,          [  --enable-jit            enable JIT compiler [default=yes]], [WANT_JIT=$enableval], [WANT_JIT=yes])
AC_ARG_ENABLE(ppc-emulator, [  --enable-ppc-emulator   use the selected PowerPC emulator [default=auto]], [WANT_EMULATED_PPC=$enableval], [WANT_EMULATED_PPC=auto])
AC_ARG_ENABLE(xf86-dga,     [  --enable-xf86-dga       use the XFree86 DGA extension [default=yes]], [WANT_XF86_DGA=$enableval], [WANT_XF86_DGA=yes])
AC_ARG_ENABLE(xf86-vidmode, [  --enable-xf86-vidmode   use the XFree86 VidMode extension [default=yes]], [WANT_XF86_VIDMODE=$enableval], [WANT_XF86_VIDMODE=yes])
AC_ARG_ENABLE(vosf,         [  --enable-vosf           enable video on SEGV signals [default=yes]], [WANT_VOSF=$enableval], [WANT_VOSF=yes])
AC_ARG_WITH(esd,            [  --with-esd              support ESD for sound under Linux/FreeBSD [default=yes]], [WANT_ESD=$withval], [WANT_ESD=yes])
AC_ARG_WITH(gtk,            [  --with-gtk              use GTK user interface [default=yes]], [WANT_GTK=$withval], [WANT_GTK=yes])
AC_ARG_WITH(mon,            [  --with-mon              use mon as debugger [default=yes]], [WANT_MON=$withval], [WANT_MON=yes])

dnl Checks for programs.
AC_PROG_CC
AC_PROG_CPP
AC_PROG_CXX
AC_PROG_MAKE_SET
AC_PROG_INSTALL

dnl Check for PowerPC target CPU.
HAVE_PPC=no
AC_MSG_CHECKING(for PowerPC target CPU)
AC_EGREP_CPP(yes,
[
#ifdef __powerpc__
  yes
#endif
#ifdef __ppc__
  yes
#endif
], [AC_MSG_RESULT(yes); HAVE_PPC=yes], AC_MSG_RESULT(no))

dnl We use native CPU if possible.
EMULATED_PPC=yes
case $WANT_EMULATED_PPC in
  auto) [[ "x$HAVE_PPC" = "xyes" ]] && EMULATED_PPC=no;;
  no)   EMULATED_PPC=no;;
esac
if [[ "x$EMULATED_PPC" = "xyes" ]]; then
  AC_DEFINE(EMULATED_PPC)
fi

dnl We use mon if possible.
MONSRCS=
case "x$WANT_MON" in
x/* | x.*)
  mon_srcdir=$WANT_MON
  WANT_MON=yes
  ;;
xyes)
  mon_srcdir=../../../mon/src
  ;;
esac
if [[ "x$WANT_MON" = "xyes" ]]; then
  AC_MSG_CHECKING(for mon)
  if grep mon_init $mon_srcdir/mon.h >/dev/null 2>/dev/null; then
    AC_MSG_RESULT(yes)
    AC_DEFINE(ENABLE_MON)
    MONSRCS="$mon_srcdir/mon.cpp $mon_srcdir/mon_6502.cpp $mon_srcdir/mon_z80.cpp $mon_srcdir/mon_cmd.cpp $mon_srcdir/mon_lowmem.cpp $mon_srcdir/mon_disass.cpp $mon_srcdir/mon_ppc.cpp $mon_srcdir/disass/floatformat.c $mon_srcdir/disass/i386-dis.c $mon_srcdir/disass/m68k-dis.c $mon_srcdir/disass/m68k-opc.c"
    CXXFLAGS="$CXXFLAGS -I$mon_srcdir -I$mon_srcdir/disass"
    AC_CHECK_LIB(ncurses, tgetent, ,
      AC_CHECK_LIB(termcap, tgetent, ,
        AC_CHECK_LIB(termlib, tgetent, ,
          AC_CHECK_LIB(terminfo, tgetent, ,
            AC_CHECK_LIB(Hcurses, tgetent, ,
              AC_CHECK_LIB(curses, tgetent))))))
    AC_CHECK_LIB(readline, readline)
    AC_CHECK_HEADERS(readline.h history.h readline/readline.h readline/history.h)
  else
    AC_MSG_RESULT(no)
    AC_MSG_WARN([Could not find mon, ignoring --with-mon.])
    WANT_MON=no
  fi
fi

dnl Checks for libraries.
AC_CHECK_LIB(posix4, sem_init)

dnl We need X11.
AC_PATH_XTRA
if [[ "x$no_x" = "xyes" ]]; then
  AC_MSG_ERROR([You need X11 to run SheepShaver.])
fi
CFLAGS="$CFLAGS $X_CFLAGS"
CXXFLAGS="$CXXFLAGS $X_CFLAGS"
LIBS="$LIBS $X_PRE_LIBS $X_LIBS -lX11 -lXext $X_EXTRA_LIBS"

dnl We need pthreads on non-PowerPC systems. Try libpthread first, then libc_r (FreeBSD), then PTL.
HAVE_PTHREADS=yes
case $EMULATED_PPC:$target_os in
no:linux*)
  dnl We do have our own pthread_cancel() implementation
  AC_DEFINE(HAVE_PTHREAD_CANCEL, 1, [Define if you have the pthread_cancel function.])
  ;;
*:*)
  AC_CHECK_LIB(pthread, pthread_create, , [
    AC_CHECK_LIB(c_r, pthread_create, , [
      AC_CHECK_LIB(PTL, pthread_create, , [
        AC_MSG_ERROR([You need pthreads to run Basilisk II.])
      ])
    ])
  ])
  AC_CHECK_FUNCS(pthread_cancel)
  AC_CHECK_FUNCS(pthread_mutexattr_setprotocol)
  AC_CHECK_FUNCS(pthread_mutexattr_settype)
  AC_CHECK_FUNCS(pthread_mutexattr_setpshared)
  if [[ "x$HAVE_PTHREADS" = "xyes" ]]; then
    AC_DEFINE(HAVE_PTHREADS, 1, [Define if pthreads are available.])
  fi
  dnl If POSIX.4 semaphores are not available, we emulate them with pthread mutexes.
  SEMSRC=
  AC_CHECK_FUNCS(sem_init, , [
  if test "x$HAVE_PTHREADS" = "xyes"; then
    SEMSRC=posix_sem.cpp
  fi
  ])
  ;;
esac

dnl We use XFree86 DGA if possible.
if [[ "x$WANT_XF86_DGA" = "xyes" ]]; then
  AC_CHECK_LIB(Xxf86dga, XF86DGAQueryExtension, [
    AC_DEFINE(ENABLE_XF86_DGA)
    LIBS="$LIBS -lXxf86dga"
  ], [
    AC_MSG_WARN([Could not find XFree86 DGA extension, ignoring --enable-xf86-dga.])
    WANT_XF86_DGA=no
  ])
fi

dnl We use XFree86 VidMode if possible.
if [[ "x$WANT_XF86_VIDMODE" = "xyes" ]]; then
  AC_CHECK_LIB(Xxf86vm, XF86VidModeQueryExtension, [
    AC_DEFINE(ENABLE_XF86_VIDMODE)
    LIBS="$LIBS -lXxf86vm"
  ], [
    AC_MSG_WARN([Could not find XFree86 VidMode extension, ignoring --enable-xf86-vidmode.])
    WANT_XF86_VIDMODE=no
  ])
fi

dnl We use GTK+ if possible.
UISRCS=../dummy/prefs_editor_dummy.cpp
if [[ "x$WANT_GTK" = "xyes" ]]; then
  AM_PATH_GTK(1.2.0, [
    AC_DEFINE(ENABLE_GTK)
    CFLAGS="$CFLAGS $GTK_CFLAGS"
    CXXFLAGS="$CXXFLAGS $GTK_CFLAGS"
    LIBS="$LIBS $GTK_LIBS"
    UISRCS=prefs_editor_gtk.cpp
  ], [
    AC_MSG_WARN([Could not find GTK+, disabling user interface.])
    WANT_GTK=no
  ])
fi

dnl We use ESD if possible.
if [[ "x$WANT_ESD" = "xyes" ]]; then
  AM_PATH_ESD(0.2.8, [
    AC_DEFINE(ENABLE_ESD)
    CFLAGS="$CFLAGS $ESD_CFLAGS"
    CXXFLAGS="$CXXFLAGS $ESD_CFLAGS"
    LIBS="$LIBS $ESD_LIBS"
  ], [
    AC_MSG_WARN([Could not find ESD, disabling ESD support.])
    WANT_ESD=no
  ])
fi

dnl Checks for header files.
AC_HEADER_STDC
AC_HEADER_SYS_WAIT
AC_CHECK_HEADERS(mach/vm_map.h mach/mach_init.h sys/mman.h)
AC_CHECK_HEADERS(sys/time.h sys/times.h)
AC_CHECK_HEADERS(unistd.h fcntl.h byteswap.h)

dnl Checks for typedefs, structures, and compiler characteristics.
AC_C_BIGENDIAN
AC_C_CONST
AC_C_INLINE
AC_CHECK_SIZEOF(short, 2)
AC_CHECK_SIZEOF(int, 4)
AC_CHECK_SIZEOF(long, 4)
AC_CHECK_SIZEOF(long long, 8)
AC_CHECK_SIZEOF(float, 4)
AC_CHECK_SIZEOF(double, 8)
AC_CHECK_SIZEOF(void *, 4)
AC_TYPE_OFF_T
AC_CHECK_TYPE(loff_t, off_t)
AC_TYPE_SIZE_T
AC_TYPE_SIGNAL
AC_HEADER_TIME
AC_STRUCT_TM

dnl Check whether struct sigaction has sa_restorer member.
AC_CACHE_CHECK([whether struct sigaction has sa_restorer],
  ac_cv_signal_sa_restorer, [
  AC_TRY_COMPILE([
    #include <signal.h>
  ], [struct sigaction sa; sa.sa_restorer = 0;],
  ac_cv_signal_sa_restorer=yes, ac_cv_signal_sa_restorer=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_signal_sa_restorer=no
  )
])
if [[ "x$ac_cv_signal_sa_restorer" = "xyes" ]]; then
  AC_DEFINE(HAVE_SIGNAL_SA_RESTORER)
fi

dnl Checks for library functions.
AC_CHECK_FUNCS(strdup cfmakeraw)
AC_CHECK_FUNCS(nanosleep)
AC_CHECK_FUNCS(sigaction signal)
AC_CHECK_FUNCS(mmap mprotect munmap)
AC_CHECK_FUNCS(vm_allocate vm_deallocate vm_protect)

dnl Darwin seems to define mach_task_self() instead of task_self().
AC_CHECK_FUNCS(mach_task_self task_self)

dnl We need clock_gettime() for better performance but it may drag
dnl libpthread in, which we don't want for native ppc mode
case $EMULATED_PPC:$target_os in
no:linux*)
  ;;
*:*)
  AC_SEARCH_LIBS(clock_gettime, [rt posix4])
  AC_CHECK_FUNCS(clock_gettime)
  ;;
esac

dnl Select system-dependant sources.
SERIALSRC=serial_unix.cpp
ETHERSRC=../dummy/ether_dummy.cpp
SCSISRC=../dummy/scsi_dummy.cpp
AUDIOSRC=../dummy/audio_dummy.cpp
EXTRASYSSRCS=
case "$target_os" in
linux*)
  ETHERSRC=Linux/ether_linux.cpp
  AUDIOSRC=audio_oss_esd.cpp
  SCSISRC=Linux/scsi_linux.cpp
  if [[ "x$EMULATED_PPC" = "xno" ]]; then
    EXTRASYSSRCS="Linux/paranoia.cpp Linux/sheepthreads.c Linux/asm_linux.S"
  fi
  ;;
darwin*)
  if [[ "x$EMULATED_PPC" = "xno" ]]; then
    EXTRASYSSRCS="Darwin/paranoia.cpp Linux/asm_linux.S"
  fi
  ;;
esac
SYSSRCS="$SERIALSRC $ETHERSRC $SCSISRC $AUDIOSRC $SEMSRC $UISRCS $MONSRCS $EXTRASYSSRCS"

dnl Define a macro that translates a yesno-variable into a C macro definition
dnl to be put into the config.h file
dnl $1 -- the macro to define
dnl $2 -- the value to translate
dnl $3 -- template name
AC_DEFUN(AC_TRANSLATE_DEFINE, [
    if [[ "x$2" = "xyes" -o "x$2" = "xguessing yes" ]]; then
        AC_DEFINE($1, 1, $3)
    fi
])

dnl Various checks if the system supports vm_allocate() and the like functions.
have_mach_vm=no
if [[ "x$ac_cv_func_vm_allocate" = "xyes" -a "x$ac_cv_func_vm_deallocate" = "xyes" -a \
      "x$ac_cv_func_vm_protect" = "xyes" ]]; then
  have_mach_vm=yes
fi
AC_TRANSLATE_DEFINE(HAVE_MACH_VM, "$have_mach_vm",
  [Define if your system has a working vm_allocate()-based memory allocator.])

dnl Check that vm_allocate(), vm_protect() work
if [[ "x$have_mach_vm" = "xyes" ]]; then

AC_CACHE_CHECK([whether vm_protect works],
  ac_cv_vm_protect_works, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_cv_vm_protect_works=yes
  dnl First the tests that should segfault
  for test_def in NONE_READ NONE_WRITE READ_WRITE; do
    AC_TRY_RUN([
      #define CONFIGURE_TEST_VM_MAP
      #define TEST_VM_PROT_$test_def
      #include "vm_alloc.cpp"
    ], ac_cv_vm_protect_works=no, rm -f core,
    dnl When cross-compiling, do not assume anything
    ac_cv_vm_protect_works="guessing no"
    )
  done
  AC_TRY_RUN([
    #define CONFIGURE_TEST_VM_MAP
    #define TEST_VM_PROT_RDWR_WRITE
    #include "vm_alloc.cpp"
  ], , ac_cv_vm_protect_works=no,
  dnl When cross-compiling, do not assume anything
  ac_cv_vm_protect_works="guessing no"
  )
  AC_LANG_RESTORE
  ]
)

dnl Remove support for vm_allocate() if vm_protect() does not work
if [[ "x$have_mach_vm" = "xyes" ]]; then
  case $ac_cv_vm_protect_works in
    *yes) have_mach_vm=yes;;
    *no) have_mach_vm=no;;
  esac
fi
AC_TRANSLATE_DEFINE(HAVE_MACH_VM, "$have_mach_vm",
  [Define if your system has a working vm_allocate()-based memory allocator.])

fi dnl HAVE_MACH_VM

dnl Various checks if the system supports mmap() and the like functions.
dnl ... and Mach memory allocators are not supported
have_mmap_vm=no
if [[ "x$ac_cv_func_mmap" = "xyes" -a "x$ac_cv_func_munmap" = "xyes" -a \
      "x$ac_cv_func_mprotect" = "xyes" ]]; then
  if [[ "x$have_mach_vm" = "xno" ]]; then
    have_mmap_vm=yes
  fi
fi
AC_TRANSLATE_DEFINE(HAVE_MMAP_VM, "$have_mmap_vm",
  [Define if your system has a working mmap()-based memory allocator.])

dnl Check that mmap() and associated functions work.
if [[ "x$have_mmap_vm" = "xyes" ]]; then

dnl Check if we have a working anonymous mmap()
AC_CACHE_CHECK([whether mmap supports MAP_ANON],
  ac_cv_mmap_anon, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #define HAVE_MMAP_ANON
    #define CONFIGURE_TEST_VM_MAP
    #define TEST_VM_MMAP_ANON
    #include "vm_alloc.cpp"
  ], ac_cv_mmap_anon=yes, ac_cv_mmap_anon=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_mmap_anon="guessing no"
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(HAVE_MMAP_ANON, "$ac_cv_mmap_anon",
  [Define if <sys/mman.h> defines MAP_ANON and mmap()'ing with MAP_ANON works.])

AC_CACHE_CHECK([whether mmap supports MAP_ANONYMOUS],
  ac_cv_mmap_anonymous, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #define HAVE_MMAP_ANONYMOUS
    #define CONFIGURE_TEST_VM_MAP
    #define TEST_VM_MMAP_ANON
    #include "vm_alloc.cpp"
  ], ac_cv_mmap_anonymous=yes, ac_cv_mmap_anonymous=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_mmap_anonymous="guessing no"
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(HAVE_MMAP_ANONYMOUS, "$ac_cv_mmap_anonymous",
  [Define if <sys/mman.h> defines MAP_ANONYMOUS and mmap()'ing with MAP_ANONYMOUS works.])

AC_CACHE_CHECK([whether mprotect works],
  ac_cv_mprotect_works, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  ac_cv_mprotect_works=yes
  dnl First the tests that should segfault
  for test_def in NONE_READ NONE_WRITE READ_WRITE; do
    AC_TRY_RUN([
      #define CONFIGURE_TEST_VM_MAP
      #define TEST_VM_PROT_$test_def
      #include "vm_alloc.cpp"
    ], ac_cv_mprotect_works=no, rm -f core,
    dnl When cross-compiling, do not assume anything
    ac_cv_mprotect_works="guessing no"
    )
  done
  AC_TRY_RUN([
    #define CONFIGURE_TEST_VM_MAP
    #define TEST_VM_PROT_RDWR_WRITE
    #include "vm_alloc.cpp"
  ], , ac_cv_mprotect_works=no,
  dnl When cross-compiling, do not assume anything
  ac_cv_mprotect_works="guessing no"
  )
  AC_LANG_RESTORE
  ]
)

dnl Remove support for mmap() if mprotect() does not work
if [[ "x$have_mmap_vm" = "xyes" ]]; then
  case $ac_cv_mprotect_works in
    *yes) have_mmap_vm=yes;;
    *no) have_mmap_vm=no;;
  esac
fi
AC_TRANSLATE_DEFINE(HAVE_MMAP_VM, $have_mmap_vm,
  [Define if your system has a working mmap()-based memory allocator.])

fi dnl HAVE_MMAP_VM

dnl Check if we can modify the __PAGEZERO segment for use as Low Memory
AC_CACHE_CHECK([whether __PAGEZERO can be Low Memory area 0x0000-0x3000],
  ac_cv_pagezero_hack, [
  ac_cv_pagezero_hack=no 
  if AC_TRY_COMMAND([Darwin/testlmem.sh 0x3000]); then
    ac_cv_pagezero_hack=yes
    dnl might as well skip the test for mmap-able low memory
    ac_cv_can_map_lm=no
  fi
])
AC_TRANSLATE_DEFINE(PAGEZERO_HACK, "$ac_cv_pagezero_hack",
  [Define if the __PAGEZERO Mach-O Low Memory Globals hack works on this system.])

dnl Check if we can mmap 0x3000 bytes from 0x0000
AC_CACHE_CHECK([whether we can map Low Memory area 0x0000-0x3000],
  ac_cv_can_map_lm, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #include "vm_alloc.cpp"
    int main(void) { /* returns 0 if we could map the lowmem globals */
      volatile char * lm = 0;
      if (vm_init() < 0) exit(1);
      if (vm_acquire_fixed(0, 0x2000) < 0) exit(1);
      lm[0] = 'z';
      if (vm_release((char *)lm, 0x2000) < 0) exit(1);
      vm_exit(); exit(0);
    }
  ], ac_cv_can_map_lm=yes, ac_cv_can_map_lm=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_can_map_lm="guessing no"
  )
  AC_LANG_RESTORE
  ]
)

dnl Check signal handlers need to be reinstalled
AC_CACHE_CHECK([whether signal handlers need to be reinstalled],
  ac_cv_signal_need_reinstall, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #include <stdlib.h>
    #ifdef HAVE_UNISTD_H
    #include <unistd.h>
    #endif
    #include <signal.h>
    static int handled_signal = 0;
    RETSIGTYPE sigusr1_handler(int) { handled_signal++; }
    int main(void) { /* returns 0 if signals need not to be reinstalled */
      signal(SIGUSR1, sigusr1_handler); raise(SIGUSR1); raise(SIGUSR1);
      exit(handled_signal == 2);
    }
  ], ac_cv_signal_need_reinstall=yes, ac_cv_signal_need_reinstall=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_signal_need_reinstall="guessing yes"
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(SIGNAL_NEED_REINSTALL, "$ac_cv_signal_need_reinstall",
  [Define if your system requires signals to be reinstalled.])

dnl Check if sigaction handlers need to be reinstalled
AC_CACHE_CHECK([whether sigaction handlers need to be reinstalled],
  ac_cv_sigaction_need_reinstall, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #include <stdlib.h>
    #ifdef HAVE_UNISTD_H
    #include <unistd.h>
    #endif
    #include <signal.h>
    static int handled_signal = 0;
    RETSIGTYPE sigusr1_handler(int) { handled_signal++; }
    typedef RETSIGTYPE (*signal_handler)(int);
    static signal_handler mysignal(int sig, signal_handler handler) {
      struct sigaction old_sa;
      struct sigaction new_sa;
      new_sa.sa_handler = handler;
      return ((sigaction(sig,&new_sa,&old_sa) < 0) ? SIG_IGN : old_sa.sa_handler);
    }
    int main(void) { /* returns 0 if signals need not to be reinstalled */
      mysignal(SIGUSR1, sigusr1_handler); raise(SIGUSR1); raise(SIGUSR1);
      exit(handled_signal == 2);
    }
  ], ac_cv_sigaction_need_reinstall=yes, ac_cv_sigaction_need_reinstall=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_sigaction_need_reinstall="guessing yes"
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(SIGACTION_NEED_REINSTALL, "$ac_cv_sigaction_need_reinstall",
  [Define if your system requires sigactions to be reinstalled.])

dnl Check if Mach exceptions supported.
AC_CACHE_CHECK([whether your system supports Mach exceptions],
  ac_cv_have_mach_exceptions, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #define HAVE_MACH_EXCEPTIONS 1
    #define CONFIGURE_TEST_SIGSEGV_RECOVERY
    #include "vm_alloc.cpp"
    #include "sigsegv.cpp"
  ], [
  sigsegv_recovery=mach
  ac_cv_have_mach_exceptions=yes
  ],
  ac_cv_have_mach_exceptions=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_have_mach_exceptions=no
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(HAVE_MACH_EXCEPTIONS, "$ac_cv_have_mach_exceptions",
  [Define if your system supports Mach exceptions.])

dnl Otherwise, check if extended signals are supported.
if [[ -z "$sigsegv_recovery" ]]; then
  AC_CACHE_CHECK([whether your system supports extended signal handlers],
    ac_cv_have_extended_signals, [
    AC_LANG_SAVE
    AC_LANG_CPLUSPLUS
    AC_TRY_RUN([
      #define HAVE_SIGINFO_T 1
      #define CONFIGURE_TEST_SIGSEGV_RECOVERY
      #include "vm_alloc.cpp"
      #include "sigsegv.cpp"
    ], [
    sigsegv_recovery=siginfo
    ac_cv_have_extended_signals=yes
    ],
    ac_cv_have_extended_signals=no,
    dnl When cross-compiling, do not assume anything.
    ac_cv_have_extended_signals=no
    )
    AC_LANG_RESTORE
    ]
  )
  AC_TRANSLATE_DEFINE(HAVE_SIGINFO_T, "$ac_cv_have_extended_signals",
    [Define if your system support extended signals.])
fi

dnl Otherwise, check for subterfuges.
if [[ -z "$sigsegv_recovery" ]]; then
  AC_CACHE_CHECK([whether we then have a subterfuge for your system],
  ac_cv_have_sigcontext_hack, [
    AC_LANG_SAVE
    AC_LANG_CPLUSPLUS
    AC_TRY_RUN([
      #define HAVE_SIGCONTEXT_SUBTERFUGE 1
      #define CONFIGURE_TEST_SIGSEGV_RECOVERY
      #include "vm_alloc.cpp"
      #include "sigsegv.cpp"
    ], [
    sigsegv_recovery=sigcontext
    ac_cv_have_sigcontext_hack=yes
    ],
    ac_cv_have_sigcontext_hack=no,
    dnl When cross-compiling, do not assume anything.
    ac_cv_have_sigcontext_hack=no
    )
    AC_LANG_RESTORE
  ])
  AC_TRANSLATE_DEFINE(HAVE_SIGCONTEXT_SUBTERFUGE, "$ac_cv_have_sigcontext_hack",
    [Define if we know a hack to replace siginfo_t->si_addr member.])
fi

dnl Check if we can ignore the fault (instruction skipping in SIGSEGV handler)
AC_CACHE_CHECK([whether we can skip instruction in SIGSEGV handler],
  ac_cv_have_skip_instruction, [
  AC_LANG_SAVE
  AC_LANG_CPLUSPLUS
  AC_TRY_RUN([
    #define HAVE_SIGSEGV_SKIP_INSTRUCTION 1
    #define CONFIGURE_TEST_SIGSEGV_RECOVERY
    #include "vm_alloc.cpp"
    #include "sigsegv.cpp"
  ], ac_cv_have_skip_instruction=yes, ac_cv_have_skip_instruction=no,
  dnl When cross-compiling, do not assume anything.
  ac_cv_have_skip_instruction=no
  )
  AC_LANG_RESTORE
  ]
)
AC_TRANSLATE_DEFINE(HAVE_SIGSEGV_SKIP_INSTRUCTION, "$ac_cv_have_skip_instruction",
  [Define if we can ignore the fault (instruction skipping in SIGSEGV handler).])

dnl Can we do Video on SEGV Signals ?
CAN_VOSF=no
if [[ -n "$sigsegv_recovery" ]]; then
  CAN_VOSF=yes
fi

dnl Enable VOSF screen updates with this feature is requested and feasible
if [[ "x$WANT_VOSF" = "xyes" -a "x$CAN_VOSF" = "xyes" ]]; then
    AC_DEFINE(ENABLE_VOSF, 1, [Define if using video enabled on SEGV signals.])
else
    WANT_VOSF=no
fi

dnl Platform specific binary postprocessor
BLESS=/bin/true
if [[ "x$ac_cv_pagezero_hack" = "xyes" ]]; then
  BLESS=Darwin/lowmem
  LDFLAGS="$LDFLAGS -pagezero_size 0x3000"
fi

dnl Check for GCC 2.7 or higher.
HAVE_GCC27=no
AC_MSG_CHECKING(for GCC 2.7 or higher)
AC_EGREP_CPP(xyes,
[#if __GNUC__ - 1 > 1 || __GNUC_MINOR__ - 1 > 5
  xyes
#endif
], [AC_MSG_RESULT(yes); HAVE_GCC27=yes], AC_MSG_RESULT(no))

dnl Check for GCC 3.0 or higher.
HAVE_GCC30=no
AC_MSG_CHECKING(for GCC 3.0 or higher)
AC_EGREP_CPP(xyes,
[#if __GNUC__ >= 3
  xyes
#endif
], [AC_MSG_RESULT(yes); HAVE_GCC30=yes], AC_MSG_RESULT(no))

# Test if the compiler can generate ELF objects
AC_CACHE_CHECK([whether the compiler can generate ELF objects],
  ac_cv_elf_objects, [
  echo 'int i;' > conftest.$ac_ext
  ac_cv_elf_objects=no
  if AC_TRY_EVAL(ac_compile); then
    case `/usr/bin/file conftest.$ac_objext` in
    *"ELF"*)
      ac_cv_elf_objects=yes
      ;;
    esac
  fi
  rm -rf conftest*
])
ELF_OBJECTS=$ac_cv_elf_objects

dnl CPU emulator sources
if [[ "x$EMULATED_PPC" = "xyes" ]]; then
  CPUSRCS="\
    ../kpx_cpu/src/cpu/ppc/ppc-cpu.cpp \
    ../kpx_cpu/src/cpu/ppc/ppc-decode.cpp \
    ../kpx_cpu/src/cpu/ppc/ppc-execute.cpp \
    ../kpx_cpu/src/cpu/ppc/ppc-translate.cpp"
  CPPFLAGS="$CPPFLAGS -I../kpx_cpu/include -I../kpx_cpu/src"

  dnl Enable JIT compiler, if possible
  if [[ "x$WANT_JIT" = "xyes" ]]; then
    AC_CACHE_CHECK([whether dyngen can be used],
      ac_cv_use_dyngen, [
      case $host_cpu:$ELF_OBJECTS in
      powerpc:yes)
        ac_cv_use_dyngen=yes
        ;;
      x86_64:yes)
        ac_cv_use_dyngen=yes
        ;;
      i?86:yes)
        ac_cv_use_dyngen=yes
        ;;
      *:*)
        ac_cv_use_dyngen=no
        ;;
      esac
    ])
    if [[ "x$ac_cv_use_dyngen" = "xyes" ]]; then
      case $host_cpu in
      i?86)
        DYNGEN_OP_FLAGS="-fomit-frame-pointer -mpreferred-stack-boundary=2"
        if [[ "x$HAVE_GCC30" = "xyes" ]]; then
          DYNGEN_OP_FLAGS="$DYNGEN_OP_FLAGS -falign-functions=0"
        else
          DYNGEN_OP_FLAGS="$DYNGEN_OP_FLAGS -malign-functions=0"
        fi
        ;;
      esac
      DYNGEN_OP_FLAGS="$DYNGEN_OP_FLAGS -finline-limit=10000"
      if [[ "x$HAVE_GCC30" = "xyes" ]]; then
        DYNGEN_OP_FLAGS="$DYNGEN_OP_FLAGS -fno-reorder-blocks -fno-optimize-sibling-calls"
      fi
    else
      WANT_JIT=no
    fi
    AC_TRANSLATE_DEFINE(ENABLE_DYNGEN, $ac_cv_use_dyngen, [Define to enable dyngen engine])
    if [[ "x$WANT_JIT" = "xyes" ]]; then
      DYNGENSRCS="\
        ../kpx_cpu/src/cpu/jit/dyngen.c \
        ../kpx_cpu/src/cpu/jit/cxxdemangle.cpp"
      CPUSRCS="\
        ../kpx_cpu/src/cpu/jit/jit-cache.cpp \
        ../kpx_cpu/src/cpu/jit/basic-dyngen.cpp \
        ../kpx_cpu/src/cpu/ppc/ppc-dyngen.cpp $CPUSRCS"
    fi
  fi
  CPUSRCS="$CPUSRCS ../kpx_cpu/sheepshaver_glue.cpp"
else
  WANT_JIT=no
fi
if [[ "x$ac_cv_use_dyngen" = "xyes" ]]; then
  AC_CACHE_CHECK([whether static data regions are executable],
    ac_cv_have_static_data_exec, [
    AC_TRY_RUN([int main(void) {
#if defined(__powerpc__)
      static unsigned int p[8] = {0x4e800020,};
      asm volatile("dcbst 0,%0" : : "r" (p) : "memory");
      asm volatile("sync" : : : "memory");
      asm volatile("icbi 0,%0" : : "r" (p) : "memory");
      asm volatile("sync" : : : "memory");
      asm volatile("isync" : : : "memory");
      ((void (*)(void))p)();
      return 0;
#endif
      return 1;
    }], ac_cv_have_static_data_exec=yes, ac_cv_have_static_data_exec=no,
    dnl When cross-compiling, do not assume anything.
    ac_cv_have_static_data_exec=no
    )
  ])
fi
AC_TRANSLATE_DEFINE(HAVE_STATIC_DATA_EXEC, "$ac_cv_have_static_data_exec",
  [Define if your system marks static data pages as executable.])

if [[ "x$WANT_JIT" = "xyes" ]]; then
  CPPFLAGS="$CPPFLAGS -DUSE_JIT"
fi

dnl Generate Makefile.
AC_SUBST(DYNGENSRCS)
AC_SUBST(DYNGEN_OP_FLAGS)
AC_SUBST(SYSSRCS)
AC_SUBST(CPUSRCS)
AC_SUBST(BLESS)
AC_OUTPUT(Makefile)

dnl Print summary.
echo
echo SheepShaver configuration summary:
echo
echo XFree86 DGA support .............. : $WANT_XF86_DGA
echo XFree86 VidMode support .......... : $WANT_XF86_VIDMODE
echo Using PowerPC emulator ........... : $EMULATED_PPC
echo Enable JIT compiler .............. : $WANT_JIT
echo Enable video on SEGV signals ..... : $WANT_VOSF
echo ESD sound support ................ : $WANT_ESD
echo GTK user interface ............... : $WANT_GTK
echo mon debugger support ............. : $WANT_MON
echo Bad memory access recovery type .. : $sigsegv_recovery
echo
echo "Configuration done. Now type \"make\"."