(Coding Conventions): Node renamed from Style Tips.

[bpt/emacs.git] / src / syssignal.h

/* syssignal.h - System-dependent definitions for signals.
   Copyright (C) 1993 Free Software Foundation, Inc.

This file is part of GNU Emacs.

GNU Emacs is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2, or (at your option)
any later version.

GNU Emacs 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 General Public License for more details.

You should have received a copy of the GNU General Public License
along with GNU Emacs; see the file COPYING.  If not, write to
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */

#ifdef POSIX_SIGNALS

/* Don't #include <signal.h>.  That header should always be #included
   before "config.h", because some configuration files (like s/hpux.h)
   indicate that SIGIO doesn't work by #undef-ing SIGIO.  If this file
   #includes <signal.h>, then that will re-#define SIGIO and confuse
   things.  */

#define SIGMASKTYPE sigset_t

#define SIGEMPTYMASK (empty_mask)
#define SIGFULLMASK (full_mask)
extern sigset_t empty_mask, full_mask, temp_mask;

/* POSIX pretty much destroys any possibility of writing sigmask as a
   macro in standard C.  */
#ifndef sigmask
#ifdef __GNUC__
#define sigmask(SIG) 				\
  ({						\
    sigset_t _mask;				\
    sigemptyset (&_mask);			\
    sigaddset (&_mask, SIG);			\
    _mask;					\
  })
#else /* ! defined (__GNUC__) */
extern sigset_t sys_sigmask ();
#define sigmask(SIG) (sys_sigmask (SIG))
#endif /* ! defined (__GNUC__) */
#endif

#define sigpause(SIG)    sys_sigpause (SIG)
#define sigblock(SIG)    sys_sigblock (SIG)
#define sigunblock(SIG)  sys_sigunblock (SIG)
#ifndef sigsetmask
#define sigsetmask(SIG)  sys_sigsetmask (SIG)
#endif
#define sighold(SIG)     ONLY_USED_IN_BSD_4_1
#define sigrelse(SIG)    ONLY_USED_IN_BSD_4_1
#undef signal
#define signal(SIG,ACT)      sys_signal(SIG,ACT)

/* Whether this is what all systems want or not, this is what
   appears to be assumed in the source, for example data.c:arith_error.  */
typedef RETSIGTYPE (*signal_handler_t) (/*int*/);

signal_handler_t sys_signal (/*int signal_number, signal_handler_t action*/);
int      sys_sigpause   (/*sigset_t new_mask*/);
sigset_t sys_sigblock   (/*sigset_t new_mask*/);
sigset_t sys_sigunblock (/*sigset_t new_mask*/);
sigset_t sys_sigsetmask (/*sigset_t new_mask*/);

#define sys_sigdel(MASK,SIG) sigdelset (&MASK,SIG)

#else /* ! defined (POSIX_SIGNALS) */
#ifdef USG5_4

#ifndef sigblock
#define sigblock(sig) (sigprocmask (SIG_BLOCK, SIGEMPTYMASK | sig, NULL))
#endif

#define sigunblock(sig) (sigprocmask (SIG_SETMASK, SIGFULLMASK & ~(sig), NULL))

#else
#ifdef USG

#define sigunblock(sig) 

#else

#define sigunblock(SIG) \
{ SIGMASKTYPE omask = sigblock (SIGEMPTYMASK); sigsetmask (omask & ~SIG); }

#endif /* ! defined (USG) */
#endif /* ! defined (USG5_4) */
#endif /* ! defined (POSIX_SIGNALS) */

#ifndef SIGMASKTYPE
#define SIGMASKTYPE int
#endif

#ifndef SIGEMPTYMASK
#define SIGEMPTYMASK (0)
#endif

#ifndef SIGFULLMASK
#define SIGFULLMASK (0xffffffff)
#endif

#ifndef sigmask
#define sigmask(no) (1L << ((no) - 1))
#endif

#ifndef sigunblock
#define sigunblock(SIG) \
{ SIGMASKTYPE omask = sigblock (SIGFULLMASK); sigsetmask (omask & ~SIG); }
#endif

#ifndef BSD4_1
#define sigfree() sigsetmask (SIGEMPTYMASK)
#endif /* not BSD4_1 */

#ifdef BSD4_1
#define SIGIO SIGTINT
/* sigfree is in sysdep.c */
#endif /* BSD4_1 */

/* On bsd, [man says] kill does not accept a negative number to kill a pgrp.
   Must do that using the killpg call.  */
#ifdef BSD_SYSTEM
#define EMACS_KILLPG(gid, signo) (killpg ( (gid), (signo)))
#else
#ifdef WINDOWSNT
#define EMACS_KILLPG(gid, signo) (kill (gid, signo))
#else
#define EMACS_KILLPG(gid, signo) (kill   (-(gid), (signo)))
#endif
#endif

/* Define SIGCHLD as an alias for SIGCLD.  There are many conditionals
   testing SIGCHLD.  */
#ifndef VMS
#ifdef SIGCLD
#ifndef SIGCHLD
#define SIGCHLD SIGCLD
#endif /* SIGCHLD */
#endif /* ! defined (SIGCLD) */
#endif /* VMS */