[bpt/guile.git] / libguile / __scm.h

/* classes: h_files */

#ifndef __SCMH
#define __SCMH
/*	Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc.
 * 
 * This program 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.
 * 
 * This program 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 this software; see the file COPYING.  If not, write to
 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
 * Boston, MA 02111-1307 USA
 *
 * As a special exception, the Free Software Foundation gives permission
 * for additional uses of the text contained in its release of GUILE.
 *
 * The exception is that, if you link the GUILE library with other files
 * to produce an executable, this does not by itself cause the
 * resulting executable to be covered by the GNU General Public License.
 * Your use of that executable is in no way restricted on account of
 * linking the GUILE library code into it.
 *
 * This exception does not however invalidate any other reasons why
 * the executable file might be covered by the GNU General Public License.
 *
 * This exception applies only to the code released by the
 * Free Software Foundation under the name GUILE.  If you copy
 * code from other Free Software Foundation releases into a copy of
 * GUILE, as the General Public License permits, the exception does
 * not apply to the code that you add in this way.  To avoid misleading
 * anyone as to the status of such modified files, you must delete
 * this exception notice from them.
 *
 * If you write modifications of your own for GUILE, it is your choice
 * whether to permit this exception to apply to your modifications.
 * If you do not wish that, delete this exception notice.  */
\f
/* {Supported Options}
 *
 * These may be defined or undefined.
 */

/* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
 * arguments is always checked for application of closures.  If the
 * compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
 * Otherwise, number of argument checks for closures are made only when
 * the function position (whose value is the closure) of a combination is
 * not an ILOC or GLOC.  When the function position of a combination is a
 * symbol it will be checked only the first time it is evaluated because
 * it will then be replaced with an ILOC or GLOC.
 */
#undef SCM_RECKLESS
#define SCM_CAUTIOUS

/* After looking up a local for the first time, rewrite the
 * code graph, caching its position.
 */
#define MEMOIZE_LOCALS

/* All the number support there is.
 */
#define SCM_FLOATS
#define BIGNUMS

/* GC should relinquish empty cons-pair arenas. 
 */
#define GC_FREE_SEGMENTS

/* Provide a scheme-accessible count-down timer that
 * generates a pseudo-interrupt.
 */
#define TICKS


/* Use engineering notation when converting numbers strings?
 */
#undef ENGNOT

/* Include support for uniform arrays?
 *
 * Possibly some of the initialization code depends on this
 * being defined, but that is a bug and should be fixed.
 */
#define ARRAYS

#undef SCM_CAREFUL_INTS
\f
/* {Unsupported Options}
 *
 * These must be defined as given here.
 */


#define CCLO

/* Guile Scheme supports the #f/() distinction; Guile Lisp won't.  We
   have horrible plans for their unification.  */
#undef SICP

\f

/* Random options (not yet supported or in final form). */

#define STACK_CHECKING
#undef NO_CEVAL_STACK_CHECKING
#undef LONGLONGS

/* Some auto-generated .h files contain unused prototypes
 * that need these typedefs.
 */
typedef long long_long;
typedef unsigned long ulong_long;


\f
/* What did the configure script discover about the outside world?  */
#include "libguile/scmconfig.h"

\f
/* Write prototype declarations like this:
     int foo SCM_P ((int a, int b));
   At definitions, use K&R style declarations, but make sure there's a
   declarative prototype (as above) in scope.  This will give you
   argument type checking, when available, and be harmless otherwise.  */
#ifdef __STDC__
#  define SCM_P(x) x
#else
#  define SCM_P(x) ()
#endif

\f

/* Define
 *
 * SCM_CHAR_CODE_LIMIT		== UCHAR_MAX + 1
 * SCM_MOST_POSITIVE_FIXNUM 	(LONG_MAX>>2)
 * SCM_MOST_NEGATIVE_FIXNUM 	== SCM_SRS((long)LONG_MIN, 2)
 */

#ifdef HAVE_LIMITS_H
# include <limits.h>
# ifdef UCHAR_MAX
#  define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
# else
#  define SCM_CHAR_CODE_LIMIT 256L
# endif /* def UCHAR_MAX */
# define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
# ifdef _UNICOS			/* Stupid cray bug */
#  define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
# else
#  define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
# endif				/* UNICOS */
#else
# define SCM_CHAR_CODE_LIMIT 256L
# define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
# if (0 != ~0)
#  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
# else
#  define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
# endif /*  (0 != ~0) */
#endif /* def HAVE_LIMITS_H */
\f

#ifdef STDC_HEADERS
# include <stdlib.h>
# ifdef AMIGA
#  include <stddef.h>
# endif /* def AMIGA */
# define scm_sizet size_t
#else
# ifdef _SIZE_T
#  define scm_sizet size_t
# else
#  define scm_sizet unsigned int
# endif /* def _SIZE_T */
#endif /* def STDC_HEADERS */

\f

#include "libguile/tags.h"

\f
#ifdef vms
# ifndef CHEAP_CONTINUATIONS
   typedef int jmp_buf[17];
   extern int setjump(jmp_buf env);
   extern int longjump(jmp_buf env, int ret);
#  define setjmp setjump
#  define longjmp longjump
# else
#  include <setjmp.h>
# endif
#else				/* ndef vms */
# ifdef _CRAY1
    typedef int jmp_buf[112];
    extern int setjump(jmp_buf env);
    extern int longjump(jmp_buf env, int ret);
#  define setjmp setjump
#  define longjmp longjump
# else				/* ndef _CRAY1 */
#  include <setjmp.h>
# endif				/* ndef _CRAY1 */
#endif				/* ndef vms */

/* James Clark came up with this neat one instruction fix for
 * continuations on the SPARC.  It flushes the register windows so
 * that all the state of the process is contained in the stack. 
 */

#ifdef sparc
# define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
#else
# define SCM_FLUSH_REGISTER_WINDOWS /* empty */
#endif

/* If stack is not longword aligned then 
 */

/* #define SHORT_ALIGN */
#ifdef THINK_C
# define SHORT_ALIGN
#endif
#ifdef MSDOS
# define SHORT_ALIGN
#endif
#ifdef atarist
# define SHORT_ALIGN
#endif

#ifdef SHORT_ALIGN
typedef short SCM_STACKITEM;
#else
typedef long SCM_STACKITEM;
#endif
\f

#ifndef USE_THREADS
#define SCM_THREAD_DEFER
#define SCM_THREAD_ALLOW
#define SCM_THREAD_REDEFER
#define SCM_THREAD_REALLOW_1
#define SCM_THREAD_REALLOW_2
#define SCM_THREAD_SWITCHING_CODE
#endif

extern unsigned int scm_async_clock;

#define SCM_ASYNC_TICK \
{ \
  if (0 == --scm_async_clock) \
    scm_async_click (); \
} \

#ifdef SCM_CAREFUL_INTS
#define SCM_CHECK_NOT_DISABLED \
  if (scm_ints_disabled) \
    fputs("ints already disabled\n", stderr); \

#define SCM_CHECK_NOT_ENABLED \
  if (!scm_ints_disabled) \
    fputs("ints already enabled\n", stderr); \

#else
#define SCM_CHECK_NOT_DISABLED
#define SCM_CHECK_NOT_ENABLED
#endif


/* Anthony Green writes:
   When the compiler sees...
	   DEFER_INTS;
	   [critical code here]
	   ALLOW_INTS;
   ...it doesn't actually promise to keep the critical code within the
   boundries of the DEFER/ALLOW_INTS instructions. It may very well
   schedule it outside of the magic defined in those macros.

   However, GCC's volatile asm feature forms a barrier over which code is
   never moved. So if you add...
	   asm ("");
   ...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
   code will always remain in place.  asm's without inputs or outputs
   are implicitly volatile. */
#ifdef __GNUC__
#define SCM_FENCE asm /* volatile */ ("")
#else
#define SCM_FENCE
#endif

#define SCM_DEFER_INTS \
{ \
  SCM_FENCE; \
  SCM_CHECK_NOT_DISABLED; \
  SCM_THREAD_DEFER; \
  SCM_FENCE; \
  scm_ints_disabled = 1; \
  SCM_FENCE; \
} \


#define SCM_ALLOW_INTS_ONLY \
{ \
  SCM_THREAD_ALLOW; \
  scm_ints_disabled = 0; \
} \


#define SCM_ALLOW_INTS \
{ \
  SCM_FENCE; \
  SCM_CHECK_NOT_ENABLED; \
  SCM_THREAD_SWITCHING_CODE; \
  SCM_FENCE; \
  scm_ints_disabled = 0; \
  SCM_FENCE; \
  SCM_THREAD_ALLOW; \
  SCM_ASYNC_TICK; \
  SCM_FENCE; \
} \


#define SCM_REDEFER_INTS  \
{ \
  SCM_FENCE; \
  SCM_THREAD_REDEFER; \
  ++scm_ints_disabled; \
  SCM_FENCE; \
} \


#define SCM_REALLOW_INTS \
{ \
  SCM_FENCE; \
  SCM_THREAD_REALLOW_1; \
  SCM_THREAD_SWITCHING_CODE; \
  SCM_FENCE; \
  --scm_ints_disabled; \
  if (!scm_ints_disabled) \
    { \
      SCM_THREAD_REALLOW_2; \
      SCM_ASYNC_TICK; \
    } \
  SCM_FENCE; \
} \


#define SCM_TICK \
{ \
  SCM_DEFER_INTS; \
  SCM_ALLOW_INTS; \
} \

\f

/* Classification of critical sections
 *
 * When Guile moves to POSIX threads, it won't be possible to prevent
 * context switching.  In fact, the whole idea of context switching is
 * bogus if threads are run by different processors.  Therefore, we
 * must ultimately eliminate all critical sections or enforce them by
 * use of mutecis.
 *
 * All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
 * be classified and replaced by one of the delimiters below.  If you
 * understand what this is all about, I'd like to encourage you to
 * help with this task.  The set of classes below must of course be
 * incrementally augmented.
 *
 * MDJ 980419 <djurfeldt@nada.kth.se>
 */

/* A sections
 *
 * Allocation of a cell with type tag in the CAR.
 *
 * With POSIX threads, each thread will have a private pool of free
 * cells.  Therefore, this type of section can be removed.  But!  It
 * is important that the CDR is initialized first (with the CAR still
 * indicating a free cell) so that we can guarantee a consistent heap
 * at all times.
 */

#ifdef SCM_POSIX_THREADS
#define SCM_ENTER_A_SECTION
#define SCM_EXIT_A_SECTION
#else
#define SCM_ENTER_A_SECTION SCM_DEFER_INTS
#define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
#endif

\f

/** SCM_ASSERT
 ** 
 **/


#ifdef SCM_RECKLESS
#define SCM_ASSERT(_cond, _arg, _pos, _subr)
#define SCM_ASRTGO(_cond, _label)
#else
#define SCM_ASSERT(_cond, _arg, _pos, _subr) \
	if (!(_cond)) \
          scm_wta(_arg, (char *)(_pos), _subr)
#define SCM_ASRTGO(_cond, _label) \
        if (!(_cond)) \
          goto _label
#endif

/*
 * SCM_WTA_DISPATCH
 */

extern SCM scm_call_generic_1 (SCM gf, SCM a1);

#define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
  return ((gf) \
          ? scm_call_generic_1 ((gf), (a1)) \
          : scm_wta ((a1), (char *) (pos), (subr)))
#define SCM_GASSERT1(cond, gf, a1, pos, subr) \
  if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))

extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);

#define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
  return ((gf) \
          ? scm_call_generic_2 ((gf), (a1), (a2)) \
          : scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
#define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
  if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))

#define SCM_ARGn 		0
#define SCM_ARG1 		1
#define SCM_ARG2 		2
#define SCM_ARG3 		3
#define SCM_ARG4 		4
#define SCM_ARG5 		5
#define SCM_ARG6 		6
#define SCM_ARG7 		7 
     /* #define SCM_ARGERR(X) 		((X) < SCM_WNA \
				 ? (char *)(X) \
				 : "wrong type argument")
				 */

/* Following must match entry indexes in scm_errmsgs[].
 * Also, SCM_WNA must follow the last SCM_ARGn in sequence.
 */
#define SCM_WNA 		8
     /* #define SCM_OVSCM_FLOW 		9 */
#define SCM_OUTOFRANGE 		10
#define SCM_NALLOC 		11
     /* #define SCM_STACK_OVFLOW	12 */
     /* #define SCM_EXIT 		13 */


/* (...still matching scm_errmsgs)  These
 * are signals.  Signals may become errors
 * but are distinguished because they first
 * try to invoke a handler that can resume
 * the interrupted routine.
 */
#define SCM_HUP_SIGNAL 		14
#define SCM_INT_SIGNAL 		15
#define SCM_FPE_SIGNAL 		16
#define SCM_BUS_SIGNAL 		17
#define SCM_SEGV_SIGNAL 	18
#define SCM_ALRM_SIGNAL 	19
#define SCM_GC_SIGNAL		20
#define SCM_TICK_SIGNAL		21

#define SCM_SIG_ORD(X)		((X) - SCM_HUP_SIGNAL)
#define SCM_ORD_SIG(X)		((X) + SCM_HUP_SIGNAL)
#define SCM_NUM_SIGS		(SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)

#if 0
struct errdesc
{
  char *msg;
  char *s_response;
  short parent_err;
};


extern struct errdesc scm_errmsgs[];
#endif

\f

/* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
 * were encountered.  SCM_EXIT_FAILURE is the default code to return from
 * SCM if errors were encountered.  The return code can be explicitly
 * specified in a SCM program with (scm_quit <n>).
 */

#ifndef SCM_EXIT_SUCCESS
#ifdef vms
#define SCM_EXIT_SUCCESS 1
#else
#define SCM_EXIT_SUCCESS 0
#endif /* def vms */
#endif /* ndef SCM_EXIT_SUCCESS */
#ifndef SCM_EXIT_FAILURE
#ifdef vms
#define SCM_EXIT_FAILURE 2
#else
#define SCM_EXIT_FAILURE 1
#endif /* def vms */
#endif /* ndef SCM_EXIT_FAILURE */


\f

#endif  /* __SCMH */
Commit	Line	Data
0f2d19dd JB	1	/* classes: h_files */
	2
	3	#ifndef __SCMH
	4	#define __SCMH
7dc6e754	5	/* Copyright (C) 1995, 1996, 1998 Free Software Foundation, Inc.
0f2d19dd JB	6	*
	7	* This program is free software; you can redistribute it and/or modify
	8	* it under the terms of the GNU General Public License as published by
	9	* the Free Software Foundation; either version 2, or (at your option)
	10	* any later version.
	11	*
	12	* This program is distributed in the hope that it will be useful,
	13	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	* GNU General Public License for more details.
	16	*
	17	* You should have received a copy of the GNU General Public License
	18	* along with this software; see the file COPYING. If not, write to
82892bed JB	19	* the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
82892bed JB	20	* Boston, MA 02111-1307 USA
0f2d19dd JB	21	*
	22	* As a special exception, the Free Software Foundation gives permission
	23	* for additional uses of the text contained in its release of GUILE.
	24	*
	25	* The exception is that, if you link the GUILE library with other files
	26	* to produce an executable, this does not by itself cause the
	27	* resulting executable to be covered by the GNU General Public License.
	28	* Your use of that executable is in no way restricted on account of
	29	* linking the GUILE library code into it.
	30	*
	31	* This exception does not however invalidate any other reasons why
	32	* the executable file might be covered by the GNU General Public License.
	33	*
	34	* This exception applies only to the code released by the
	35	* Free Software Foundation under the name GUILE. If you copy
	36	* code from other Free Software Foundation releases into a copy of
	37	* GUILE, as the General Public License permits, the exception does
	38	* not apply to the code that you add in this way. To avoid misleading
	39	* anyone as to the status of such modified files, you must delete
	40	* this exception notice from them.
	41	*
	42	* If you write modifications of your own for GUILE, it is your choice
	43	* whether to permit this exception to apply to your modifications.
82892bed	44	* If you do not wish that, delete this exception notice. */
0f2d19dd JB	45	\f
	46	/* {Supported Options}
	47	*
	48	* These may be defined or undefined.
	49	*/
	50
cf7c17e9	51	/* If the compile FLAG `SCM_CAUTIOUS' is #defined then the number of
0f2d19dd	52	* arguments is always checked for application of closures. If the
cf7c17e9	53	* compile FLAG `SCM_RECKLESS' is #defined then they are not checked.
0f2d19dd JB	54	* Otherwise, number of argument checks for closures are made only when
	55	* the function position (whose value is the closure) of a combination is
	56	* not an ILOC or GLOC. When the function position of a combination is a
	57	* symbol it will be checked only the first time it is evaluated because
	58	* it will then be replaced with an ILOC or GLOC.
	59	*/
cf7c17e9 JB	60	#undef SCM_RECKLESS
cf7c17e9 JB	61	#define SCM_CAUTIOUS
0f2d19dd JB	62
	63	/* After looking up a local for the first time, rewrite the
	64	* code graph, caching its position.
	65	*/
	66	#define MEMOIZE_LOCALS
	67
	68	/* All the number support there is.
	69	*/
	70	#define SCM_FLOATS
	71	#define BIGNUMS
	72
	73	/* GC should relinquish empty cons-pair arenas.
	74	*/
	75	#define GC_FREE_SEGMENTS
	76
	77	/* Provide a scheme-accessible count-down timer that
	78	* generates a pseudo-interrupt.
	79	*/
	80	#define TICKS
	81
	82
	83	/* Use engineering notation when converting numbers strings?
	84	*/
	85	#undef ENGNOT
	86
	87	/* Include support for uniform arrays?
	88	*
	89	* Possibly some of the initialization code depends on this
	90	* being defined, but that is a bug and should be fixed.
	91	*/
	92	#define ARRAYS
	93
	94	#undef SCM_CAREFUL_INTS
	95	\f
	96	/* {Unsupported Options}
	97	*
3c205827	98	* These must be defined as given here.
0f2d19dd JB	99	*/
	100
	101
	102	#define CCLO
3c205827 JB	103
	104	/* Guile Scheme supports the #f/() distinction; Guile Lisp won't. We
	105	have horrible plans for their unification. */
	106	#undef SICP
0f2d19dd JB	107
	108	\f
	109
80c78696	110	/* Random options (not yet supported or in final form). */
0f2d19dd	111
80c78696 MD	112	#define STACK_CHECKING
80c78696 MD	113	#undef NO_CEVAL_STACK_CHECKING
0f2d19dd JB	114	#undef LONGLONGS
	115
	116	/* Some auto-generated .h files contain unused prototypes
	117	* that need these typedefs.
	118	*/
	119	typedef long long_long;
	120	typedef unsigned long ulong_long;
	121
	122
	123	\f
b971d089	124	/* What did the configure script discover about the outside world? */
2a1d8241	125	#include "libguile/scmconfig.h"
b971d089 JB	126
	127	\f
	128	/* Write prototype declarations like this:
3e8a29f5	129	int foo SCM_P ((int a, int b));
b971d089 JB	130	At definitions, use K&R style declarations, but make sure there's a
	131	declarative prototype (as above) in scope. This will give you
	132	argument type checking, when available, and be harmless otherwise. */
	133	#ifdef __STDC__
3e8a29f5	134	# define SCM_P(x) x
b971d089	135	#else
72713b2f	136	# define SCM_P(x) ()
b971d089 JB	137	#endif
	138
	139	\f
0f2d19dd JB	140
	141	/* Define
	142	*
e2806c10	143	* SCM_CHAR_CODE_LIMIT == UCHAR_MAX + 1
0f2d19dd JB	144	* SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
	145	* SCM_MOST_NEGATIVE_FIXNUM == SCM_SRS((long)LONG_MIN, 2)
	146	*/
	147
b971d089	148	#ifdef HAVE_LIMITS_H
0f2d19dd JB	149	# include <limits.h>
0f2d19dd JB	150	# ifdef UCHAR_MAX
e2806c10	151	# define SCM_CHAR_CODE_LIMIT (UCHAR_MAX+1L)
0f2d19dd	152	# else
e2806c10	153	# define SCM_CHAR_CODE_LIMIT 256L
0f2d19dd JB	154	# endif /* def UCHAR_MAX */
	155	# define SCM_MOST_POSITIVE_FIXNUM (LONG_MAX>>2)
	156	# ifdef _UNICOS /* Stupid cray bug */
	157	# define SCM_MOST_NEGATIVE_FIXNUM ((long)LONG_MIN/4)
	158	# else
	159	# define SCM_MOST_NEGATIVE_FIXNUM SCM_SRS((long)LONG_MIN, 2)
	160	# endif /* UNICOS */
	161	#else
e2806c10	162	# define SCM_CHAR_CODE_LIMIT 256L
0f2d19dd JB	163	# define SCM_MOST_POSITIVE_FIXNUM ((long)((unsigned long)~0L>>3))
	164	# if (0 != ~0)
	165	# define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM-1)
	166	# else
	167	# define SCM_MOST_NEGATIVE_FIXNUM (-SCM_MOST_POSITIVE_FIXNUM)
	168	# endif /* (0 != ~0) */
b971d089	169	#endif /* def HAVE_LIMITS_H */
0f2d19dd JB	170	\f
0f2d19dd JB	171
2a1d8241 JB	172	#ifdef STDC_HEADERS
	173	# include <stdlib.h>
	174	# ifdef AMIGA
	175	# include <stddef.h>
	176	# endif /* def AMIGA */
	177	# define scm_sizet size_t
	178	#else
	179	# ifdef _SIZE_T
	180	# define scm_sizet size_t
	181	# else
	182	# define scm_sizet unsigned int
	183	# endif /* def _SIZE_T */
	184	#endif /* def STDC_HEADERS */
	185
	186	\f
	187
	188	#include "libguile/tags.h"
0f2d19dd JB	189
	190	\f
	191	#ifdef vms
	192	# ifndef CHEAP_CONTINUATIONS
	193	typedef int jmp_buf[17];
	194	extern int setjump(jmp_buf env);
	195	extern int longjump(jmp_buf env, int ret);
	196	# define setjmp setjump
	197	# define longjmp longjump
	198	# else
	199	# include <setjmp.h>
	200	# endif
	201	#else /* ndef vms */
	202	# ifdef _CRAY1
	203	typedef int jmp_buf[112];
	204	extern int setjump(jmp_buf env);
	205	extern int longjump(jmp_buf env, int ret);
	206	# define setjmp setjump
	207	# define longjmp longjump
	208	# else /* ndef _CRAY1 */
	209	# include <setjmp.h>
	210	# endif /* ndef _CRAY1 */
	211	#endif /* ndef vms */
	212
0f2d19dd JB	213	/* James Clark came up with this neat one instruction fix for
	214	* continuations on the SPARC. It flushes the register windows so
	215	* that all the state of the process is contained in the stack.
	216	*/
	217
	218	#ifdef sparc
	219	# define SCM_FLUSH_REGISTER_WINDOWS asm("ta 3")
	220	#else
	221	# define SCM_FLUSH_REGISTER_WINDOWS /* empty */
	222	#endif
	223
	224	/* If stack is not longword aligned then
	225	*/
	226
	227	/* #define SHORT_ALIGN */
	228	#ifdef THINK_C
	229	# define SHORT_ALIGN
	230	#endif
	231	#ifdef MSDOS
	232	# define SHORT_ALIGN
	233	#endif
	234	#ifdef atarist
	235	# define SHORT_ALIGN
	236	#endif
	237
	238	#ifdef SHORT_ALIGN
	239	typedef short SCM_STACKITEM;
	240	#else
	241	typedef long SCM_STACKITEM;
	242	#endif
	243	\f
	244
82339094	245	#ifndef USE_THREADS
25d3ee9d MD	246	#define SCM_THREAD_DEFER
	247	#define SCM_THREAD_ALLOW
	248	#define SCM_THREAD_REDEFER
	249	#define SCM_THREAD_REALLOW_1
	250	#define SCM_THREAD_REALLOW_2
	251	#define SCM_THREAD_SWITCHING_CODE
82339094 MD	252	#endif
82339094 MD	253
0f2d19dd	254	extern unsigned int scm_async_clock;
82339094	255
25d3ee9d MD	256	#define SCM_ASYNC_TICK \
	257	{ \
	258	if (0 == --scm_async_clock) \
	259	scm_async_click (); \
25d3ee9d MD	260	} \
25d3ee9d MD	261
0f2d19dd JB	262	#ifdef SCM_CAREFUL_INTS
	263	#define SCM_CHECK_NOT_DISABLED \
	264	if (scm_ints_disabled) \
	265	fputs("ints already disabled\n", stderr); \
	266
	267	#define SCM_CHECK_NOT_ENABLED \
	268	if (!scm_ints_disabled) \
	269	fputs("ints already enabled\n", stderr); \
	270
	271	#else
	272	#define SCM_CHECK_NOT_DISABLED
	273	#define SCM_CHECK_NOT_ENABLED
	274	#endif
	275
	276
8417b665 JB	277	/* Anthony Green writes:
	278	When the compiler sees...
	279	DEFER_INTS;
	280	[critical code here]
	281	ALLOW_INTS;
	282	...it doesn't actually promise to keep the critical code within the
	283	boundries of the DEFER/ALLOW_INTS instructions. It may very well
	284	schedule it outside of the magic defined in those macros.
	285
	286	However, GCC's volatile asm feature forms a barrier over which code is
	287	never moved. So if you add...
35eec738 JB	288	asm ("");
	289	...to each of the DEFER_INTS and ALLOW_INTS macros, the critical
	290	code will always remain in place. asm's without inputs or outputs
	291	are implicitly volatile. */
8417b665	292	#ifdef __GNUC__
35eec738	293	#define SCM_FENCE asm /* volatile */ ("")
8417b665 JB	294	#else
	295	#define SCM_FENCE
	296	#endif
	297
0f2d19dd JB	298	#define SCM_DEFER_INTS \
0f2d19dd JB	299	{ \
8417b665	300	SCM_FENCE; \
0f2d19dd	301	SCM_CHECK_NOT_DISABLED; \
25d3ee9d	302	SCM_THREAD_DEFER; \
8417b665	303	SCM_FENCE; \
0f2d19dd	304	scm_ints_disabled = 1; \
8417b665	305	SCM_FENCE; \
0f2d19dd JB	306	} \
	307
	308
	309	#define SCM_ALLOW_INTS_ONLY \
	310	{ \
25d3ee9d	311	SCM_THREAD_ALLOW; \
0f2d19dd JB	312	scm_ints_disabled = 0; \
	313	} \
	314
	315
	316	#define SCM_ALLOW_INTS \
	317	{ \
8417b665	318	SCM_FENCE; \
0f2d19dd	319	SCM_CHECK_NOT_ENABLED; \
c72cc5fb MD	320	SCM_THREAD_SWITCHING_CODE; \
c72cc5fb MD	321	SCM_FENCE; \
0f2d19dd	322	scm_ints_disabled = 0; \
8417b665 JB	323	SCM_FENCE; \
8417b665 JB	324	SCM_THREAD_ALLOW; \
0f2d19dd	325	SCM_ASYNC_TICK; \
8417b665	326	SCM_FENCE; \
0f2d19dd JB	327	} \
	328
	329
	330	#define SCM_REDEFER_INTS \
	331	{ \
c72cc5fb	332	SCM_FENCE; \
25d3ee9d	333	SCM_THREAD_REDEFER; \
0f2d19dd	334	++scm_ints_disabled; \
c72cc5fb	335	SCM_FENCE; \
0f2d19dd JB	336	} \
	337
	338
	339	#define SCM_REALLOW_INTS \
	340	{ \
c72cc5fb	341	SCM_FENCE; \
25d3ee9d	342	SCM_THREAD_REALLOW_1; \
c72cc5fb MD	343	SCM_THREAD_SWITCHING_CODE; \
c72cc5fb MD	344	SCM_FENCE; \
0f2d19dd JB	345	--scm_ints_disabled; \
0f2d19dd JB	346	if (!scm_ints_disabled) \
25d3ee9d MD	347	{ \
	348	SCM_THREAD_REALLOW_2; \
	349	SCM_ASYNC_TICK; \
	350	} \
c72cc5fb	351	SCM_FENCE; \
0f2d19dd JB	352	} \
	353
	354
c72cc5fb MD	355	#define SCM_TICK \
	356	{ \
	357	SCM_DEFER_INTS; \
	358	SCM_ALLOW_INTS; \
	359	} \
0f2d19dd JB	360
	361	\f
	362
f83e2737 MD	363	/* Classification of critical sections
	364	*
	365	* When Guile moves to POSIX threads, it won't be possible to prevent
	366	* context switching. In fact, the whole idea of context switching is
	367	* bogus if threads are run by different processors. Therefore, we
	368	* must ultimately eliminate all critical sections or enforce them by
	369	* use of mutecis.
	370	*
	371	* All instances of SCM_DEFER_INTS and SCM_ALLOW_INTS should therefore
	372	* be classified and replaced by one of the delimiters below. If you
	373	* understand what this is all about, I'd like to encourage you to
	374	* help with this task. The set of classes below must of course be
	375	* incrementally augmented.
	376	*
	377	* MDJ 980419 <djurfeldt@nada.kth.se>
	378	*/
	379
	380	/* A sections
	381	*
	382	* Allocation of a cell with type tag in the CAR.
	383	*
	384	* With POSIX threads, each thread will have a private pool of free
	385	* cells. Therefore, this type of section can be removed. But! It
	386	* is important that the CDR is initialized first (with the CAR still
	387	* indicating a free cell) so that we can guarantee a consistent heap
	388	* at all times.
	389	*/
	390
	391	#ifdef SCM_POSIX_THREADS
	392	#define SCM_ENTER_A_SECTION
	393	#define SCM_EXIT_A_SECTION
	394	#else
	395	#define SCM_ENTER_A_SECTION SCM_DEFER_INTS
	396	#define SCM_EXIT_A_SECTION SCM_ALLOW_INTS
	397	#endif
	398
	399	\f
	400
0f2d19dd JB	401	/** SCM_ASSERT
	402	**
	403	**/
	404
	405
	406	#ifdef SCM_RECKLESS
	407	#define SCM_ASSERT(_cond, _arg, _pos, _subr)
	408	#define SCM_ASRTGO(_cond, _label)
	409	#else
	410	#define SCM_ASSERT(_cond, _arg, _pos, _subr) \
	411	if (!(_cond)) \
	412	scm_wta(_arg, (char *)(_pos), _subr)
	413	#define SCM_ASRTGO(_cond, _label) \
	414	if (!(_cond)) \
	415	goto _label
	416	#endif
95b88819	417
9de33deb MD	418	/*
	419	* SCM_WTA_DISPATCH
	420	*/
	421
	422	extern SCM scm_call_generic_1 (SCM gf, SCM a1);
	423
	424	#define SCM_WTA_DISPATCH_1(gf, a1, pos, subr) \
	425	return ((gf) \
	426	? scm_call_generic_1 ((gf), (a1)) \
	427	: scm_wta ((a1), (char *) (pos), (subr)))
	428	#define SCM_GASSERT1(cond, gf, a1, pos, subr) \
	429	if (!(cond)) SCM_WTA_DISPATCH_1((gf), (a1), (pos), (subr))
	430
	431	extern SCM scm_call_generic_2 (SCM gf, SCM a1, SCM a2);
	432
	433	#define SCM_WTA_DISPATCH_2(gf, a1, a2, pos, subr) \
	434	return ((gf) \
	435	? scm_call_generic_2 ((gf), (a1), (a2)) \
	436	: scm_wta ((pos) == SCM_ARG1 ? (a1) : (a2), (char *) (pos), (subr)))
	437	#define SCM_GASSERT2(cond, gf, a1, a2, pos, subr) \
	438	if (!(cond)) SCM_WTA_DISPATCH_2((gf), (a1), (a2), (pos), (subr))
	439
0f2d19dd JB	440	#define SCM_ARGn 0
	441	#define SCM_ARG1 1
	442	#define SCM_ARG2 2
	443	#define SCM_ARG3 3
	444	#define SCM_ARG4 4
	445	#define SCM_ARG5 5
1146b6cd GH	446	#define SCM_ARG6 6
1146b6cd GH	447	#define SCM_ARG7 7
f5bf2977	448	/* #define SCM_ARGERR(X) ((X) < SCM_WNA \
0f2d19dd JB	449	? (char *)(X) \
0f2d19dd JB	450	: "wrong type argument")
f5bf2977	451	*/
0f2d19dd JB	452
	453	/* Following must match entry indexes in scm_errmsgs[].
	454	* Also, SCM_WNA must follow the last SCM_ARGn in sequence.
	455	*/
	456	#define SCM_WNA 8
e1724d20	457	/* #define SCM_OVSCM_FLOW 9 */
0f2d19dd JB	458	#define SCM_OUTOFRANGE 10
0f2d19dd JB	459	#define SCM_NALLOC 11
f5bf2977 GH	460	/* #define SCM_STACK_OVFLOW 12 */
f5bf2977 GH	461	/* #define SCM_EXIT 13 */
0f2d19dd JB	462
	463
	464	/* (...still matching scm_errmsgs) These
	465	* are signals. Signals may become errors
	466	* but are distinguished because they first
	467	* try to invoke a handler that can resume
	468	* the interrupted routine.
	469	*/
	470	#define SCM_HUP_SIGNAL 14
	471	#define SCM_INT_SIGNAL 15
	472	#define SCM_FPE_SIGNAL 16
	473	#define SCM_BUS_SIGNAL 17
	474	#define SCM_SEGV_SIGNAL 18
	475	#define SCM_ALRM_SIGNAL 19
	476	#define SCM_GC_SIGNAL 20
	477	#define SCM_TICK_SIGNAL 21
	478
	479	#define SCM_SIG_ORD(X) ((X) - SCM_HUP_SIGNAL)
	480	#define SCM_ORD_SIG(X) ((X) + SCM_HUP_SIGNAL)
	481	#define SCM_NUM_SIGS (SCM_SIG_ORD (SCM_TICK_SIGNAL) + 1)
	482
82339094	483	#if 0
0f2d19dd JB	484	struct errdesc
	485	{
	486	char *msg;
	487	char *s_response;
	488	short parent_err;
	489	};
	490
	491
	492	extern struct errdesc scm_errmsgs[];
82339094	493	#endif
0f2d19dd JB	494
	495	\f
	496
	497	/* SCM_EXIT_SUCCESS is the default code to return from SCM if no errors
	498	* were encountered. SCM_EXIT_FAILURE is the default code to return from
	499	* SCM if errors were encountered. The return code can be explicitly
	500	* specified in a SCM program with (scm_quit <n>).
	501	*/
	502
	503	#ifndef SCM_EXIT_SUCCESS
	504	#ifdef vms
	505	#define SCM_EXIT_SUCCESS 1
	506	#else
	507	#define SCM_EXIT_SUCCESS 0
	508	#endif /* def vms */
	509	#endif /* ndef SCM_EXIT_SUCCESS */
	510	#ifndef SCM_EXIT_FAILURE
	511	#ifdef vms
	512	#define SCM_EXIT_FAILURE 2
	513	#else
	514	#define SCM_EXIT_FAILURE 1
	515	#endif /* def vms */
	516	#endif /* ndef SCM_EXIT_FAILURE */
	517
	518
	519
	520	\f
0f2d19dd JB	521
0f2d19dd JB	522	#endif /* __SCMH */