lisp.h 117 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Fundamental definitions for GNU Emacs Lisp interpreter.
2
   Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1997, 1998, 1999, 2000,
3
                 2001, 2002, 2003, 2004, 2005, 2006 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
4 5 6 7 8

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
Jim Blandy's avatar
Jim Blandy committed
9
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
10 11 12 13 14 15 16 17 18
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
Lute Kamstra's avatar
Lute Kamstra committed
19 20
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */
Jim Blandy's avatar
Jim Blandy committed
21

Dave Love's avatar
Dave Love committed
22 23 24
#ifndef EMACS_LISP_H
#define EMACS_LISP_H

Gerd Moellmann's avatar
Gerd Moellmann committed
25
/* Declare the prototype for a general external function.  */
26
#if defined (PROTOTYPES) || defined (WINDOWSNT)
Gerd Moellmann's avatar
Gerd Moellmann committed
27 28 29 30 31
#define P_(proto) proto
#else
#define P_(proto) ()
#endif

32
#if 0
33 34 35 36 37
/* Define this temporarily to hunt a bug.  If defined, the size of
   strings is redundantly recorded in sdata structures so that it can
   be compared to the sizes recorded in Lisp strings.  */

#define GC_CHECK_STRING_BYTES 1
38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53

/* Define this to check for short string overrun.  */

#define GC_CHECK_STRING_OVERRUN 1

/* Define this to check the string free list.  */

#define GC_CHECK_STRING_FREE_LIST 1

/* Define this to check for malloc buffer overrun.  */

#define XMALLOC_OVERRUN_CHECK 1

/* Define this to check for errors in cons list.  */
/* #define GC_CHECK_CONS_LIST 1 */

54
#endif /* 0 */
55

56 57 58 59 60
#ifdef GC_CHECK_CONS_LIST
#define CHECK_CONS_LIST() check_cons_list()
#else
#define CHECK_CONS_LIST() 0
#endif
Jim Blandy's avatar
Jim Blandy committed
61

62
/* These are default choices for the types to use.  */
63 64 65 66 67 68 69 70 71
#ifdef _LP64
#ifndef EMACS_INT
#define EMACS_INT long
#define BITS_PER_EMACS_INT BITS_PER_LONG
#endif
#ifndef EMACS_UINT
#define EMACS_UINT unsigned long
#endif
#else /* not _LP64 */
72 73
#ifndef EMACS_INT
#define EMACS_INT int
Richard M. Stallman's avatar
Richard M. Stallman committed
74
#define BITS_PER_EMACS_INT BITS_PER_INT
75 76 77 78
#endif
#ifndef EMACS_UINT
#define EMACS_UINT unsigned int
#endif
79
#endif
80

81 82 83
/* Extra internal type checking?  */
extern int suppress_checking;
extern void die P_((const char *, const char *, int));
84 85 86

#ifdef ENABLE_CHECKING

87
#define CHECK(check,msg) (((check) || suppress_checking		\
88
			   ? (void) 0				\
89
			   : die ((msg), __FILE__, __LINE__)),	\
90
			  0)
91
#else
92

93 94
/* Produce same side effects and result, but don't complain.  */
#define CHECK(check,msg) ((check),0)
95

96
#endif
97

98
/* Used for making sure that Emacs is compilable in all
99
   configurations.  */
100 101 102 103 104

#ifdef USE_LISP_UNION_TYPE
#undef NO_UNION_TYPE
#endif

105 106
/* Define an Emacs version of "assert", since some system ones are
   flaky.  */
107 108 109
#ifndef ENABLE_CHECKING
#define eassert(X)	(void) 0
#else /* ENABLE_CHECKING */
110 111 112 113 114
#if defined (__GNUC__) && __GNUC__ >= 2 && defined (__STDC__)
#define eassert(cond) CHECK(cond,"assertion failed: " #cond)
#else
#define eassert(cond) CHECK(cond,"assertion failed")
#endif
115
#endif /* ENABLE_CHECKING */
116

117
/* Define the fundamental Lisp data structures.  */
Jim Blandy's avatar
Jim Blandy committed
118

119
/* This is the set of Lisp data types.  */
Jim Blandy's avatar
Jim Blandy committed
120 121 122

enum Lisp_Type
  {
123
    /* Integer.  XINT (obj) is the integer value.  */
Jim Blandy's avatar
Jim Blandy committed
124 125
    Lisp_Int,

126
    /* Symbol.  XSYMBOL (object) points to a struct Lisp_Symbol.  */
Jim Blandy's avatar
Jim Blandy committed
127 128
    Lisp_Symbol,

129 130 131
    /* Miscellaneous.  XMISC (object) points to a union Lisp_Misc,
       whose first member indicates the subtype.  */
    Lisp_Misc,
Jim Blandy's avatar
Jim Blandy committed
132 133

    /* String.  XSTRING (object) points to a struct Lisp_String.
134
       The length of the string, and its contents, are stored therein.  */
Jim Blandy's avatar
Jim Blandy committed
135 136
    Lisp_String,

137
    /* Vector of Lisp objects, or something resembling it.
138
       XVECTOR (object) points to a struct Lisp_Vector, which contains
139 140 141
       the size and contents.  The size field also contains the type
       information, if it's not a real vector object.  */
    Lisp_Vectorlike,
Jim Blandy's avatar
Jim Blandy committed
142

143
    /* Cons.  XCONS (object) points to a struct Lisp_Cons.  */
Jim Blandy's avatar
Jim Blandy committed
144 145
    Lisp_Cons,

Jim Blandy's avatar
Jim Blandy committed
146
    Lisp_Float,
147 148

    /* This is not a type code.  It is for range checking.  */
149
    Lisp_Type_Limit
Jim Blandy's avatar
Jim Blandy committed
150 151
  };

152
/* This is the set of data types that share a common structure.
153 154 155 156
   The first member of the structure is a type code from this set.
   The enum values are arbitrary, but we'll use large numbers to make it
   more likely that we'll spot the error if a random word in memory is
   mistakenly interpreted as a Lisp_Misc.  */
Karl Heuer's avatar
Karl Heuer committed
157 158
enum Lisp_Misc_Type
  {
159
    Lisp_Misc_Free = 0x5eab,
160
    Lisp_Misc_Marker,
161 162 163
    Lisp_Misc_Intfwd,
    Lisp_Misc_Boolfwd,
    Lisp_Misc_Objfwd,
164 165
    Lisp_Misc_Buffer_Objfwd,
    Lisp_Misc_Buffer_Local_Value,
166
    Lisp_Misc_Some_Buffer_Local_Value,
167
    Lisp_Misc_Overlay,
168
    Lisp_Misc_Kboard_Objfwd,
169
    Lisp_Misc_Save_Value,
170 171 172 173 174
    /* Currently floats are not a misc type,
       but let's define this in case we want to change that.  */
    Lisp_Misc_Float,
    /* This is not a type code.  It is for range checking.  */
    Lisp_Misc_Limit
Karl Heuer's avatar
Karl Heuer committed
175 176
  };

177 178 179 180
#ifndef GCTYPEBITS
#define GCTYPEBITS 3
#endif

181 182
/* These values are overridden by the m- file on some machines.  */
#ifndef VALBITS
183
#define VALBITS (BITS_PER_EMACS_INT - GCTYPEBITS)
184 185
#endif

Jim Blandy's avatar
Jim Blandy committed
186 187
#ifndef NO_UNION_TYPE

188
#ifndef WORDS_BIG_ENDIAN
Jim Blandy's avatar
Jim Blandy committed
189 190 191 192 193 194 195

/* Definition of Lisp_Object for little-endian machines.  */

typedef
union Lisp_Object
  {
    /* Used for comparing two Lisp_Objects;
196
       also, positive integers can be accessed fast this way.  */
197
    EMACS_INT i;
Jim Blandy's avatar
Jim Blandy committed
198 199 200

    struct
      {
201
	EMACS_INT val  : VALBITS;
202
	enum Lisp_Type type : GCTYPEBITS;
Jim Blandy's avatar
Jim Blandy committed
203 204 205
      } s;
    struct
      {
206
	EMACS_UINT val : VALBITS;
207
	enum Lisp_Type type : GCTYPEBITS;
Jim Blandy's avatar
Jim Blandy committed
208 209 210 211
      } u;
  }
Lisp_Object;

212
#else /* If WORDS_BIG_ENDIAN */
Jim Blandy's avatar
Jim Blandy committed
213 214 215 216 217

typedef
union Lisp_Object
  {
    /* Used for comparing two Lisp_Objects;
218
       also, positive integers can be accessed fast this way.  */
219
    EMACS_INT i;
Jim Blandy's avatar
Jim Blandy committed
220 221 222

    struct
      {
223
	enum Lisp_Type type : GCTYPEBITS;
224
	EMACS_INT val  : VALBITS;
Jim Blandy's avatar
Jim Blandy committed
225 226 227
      } s;
    struct
      {
228
	enum Lisp_Type type : GCTYPEBITS;
229
	EMACS_UINT val : VALBITS;
Jim Blandy's avatar
Jim Blandy committed
230 231 232 233
      } u;
  }
Lisp_Object;

234
#endif /* WORDS_BIG_ENDIAN */
Jim Blandy's avatar
Jim Blandy committed
235

236 237 238 239 240 241 242
#ifdef __GNUC__
static __inline__ Lisp_Object
LISP_MAKE_RVALUE (Lisp_Object o)
{
    return o;
}
#else
243 244 245 246 247
/* This isn't quite right - it keeps the argument as an lvalue.
   Making it const via casting would help avoid code actually
   modifying the location in question, but the casting could cover
   other type-related bugs.  */
#define LISP_MAKE_RVALUE(o) (o)
248 249
#endif

Jim Blandy's avatar
Jim Blandy committed
250 251 252
#endif /* NO_UNION_TYPE */


253
/* If union type is not wanted, define Lisp_Object as just a number.  */
Jim Blandy's avatar
Jim Blandy committed
254 255

#ifdef NO_UNION_TYPE
256
typedef EMACS_INT Lisp_Object;
257
#define LISP_MAKE_RVALUE(o) (0+(o))
258
#endif /* NO_UNION_TYPE */
Jim Blandy's avatar
Jim Blandy committed
259

260 261 262
/* Two flags that are set during GC.  On some machines, these flags
   are defined differently by the m- file.  */

Stefan Monnier's avatar
Stefan Monnier committed
263
/* In the size word of a vector, this bit means the vector has been marked.  */
264 265

#ifndef ARRAY_MARK_FLAG
266
#define ARRAY_MARK_FLAG ((EMACS_INT) ((EMACS_UINT) 1 << (VALBITS + GCTYPEBITS - 1)))
267 268
#endif /* no ARRAY_MARK_FLAG */

269 270 271 272 273 274
/* In the size word of a struct Lisp_Vector, this bit means it's really
   some other vector-like object.  */
#ifndef PSEUDOVECTOR_FLAG
#define PSEUDOVECTOR_FLAG ((ARRAY_MARK_FLAG >> 1) & ~ARRAY_MARK_FLAG)
#endif

275
/* In a pseudovector, the size field actually contains a word with one
276 277
   PSEUDOVECTOR_FLAG bit set, and exactly one of the following bits to
   indicate the actual type.  */
278 279 280 281 282 283 284 285 286
enum pvec_type
{
  PVEC_NORMAL_VECTOR = 0,
  PVEC_PROCESS = 0x200,
  PVEC_FRAME = 0x400,
  PVEC_COMPILED = 0x800,
  PVEC_WINDOW = 0x1000,
  PVEC_WINDOW_CONFIGURATION = 0x2000,
  PVEC_SUBR = 0x4000,
287 288 289
  PVEC_CHAR_TABLE = 0x8000,
  PVEC_BOOL_VECTOR = 0x10000,
  PVEC_BUFFER = 0x20000,
Gerd Moellmann's avatar
Gerd Moellmann committed
290
  PVEC_HASH_TABLE = 0x40000,
Gerd Moellmann's avatar
Gerd Moellmann committed
291
  PVEC_TYPE_MASK = 0x7fe00
292

Gerd Moellmann's avatar
Gerd Moellmann committed
293 294 295
#if 0 /* This is used to make the value of PSEUDOVECTOR_FLAG available to
	 GDB.  It doesn't work on OS Alpha.  Moved to a variable in
	 emacs.c.  */
296
  PVEC_FLAG = PSEUDOVECTOR_FLAG
Gerd Moellmann's avatar
Gerd Moellmann committed
297
#endif
298
};
299 300

/* For convenience, we also store the number of elements in these bits.  */
301
#define PSEUDOVECTOR_SIZE_MASK 0x1ff
302 303 304 305

/* Number of bits to put in each character in the internal representation
   of bool vectors.  This should not vary across implementations.  */
#define BOOL_VECTOR_BITS_PER_CHAR 8
306 307

/***** Select the tagging scheme.  *****/
308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323
/* There are basically two options that control the tagging scheme:
   - NO_UNION_TYPE says that Lisp_Object should be an integer instead
     of a union.
   - USE_LSB_TAG means that we can assume the least 3 bits of pointers are
     always 0, and we can thus use them to hold tag bits, without
     restricting our addressing space.

   If USE_LSB_TAG is not set, then we use the top 3 bits for tagging, thus
   restricting our possible address range.  Currently USE_LSB_TAG is not
   allowed together with a union.  This is not due to any fundamental
   technical (or political ;-) problem: nobody wrote the code to do it yet.

   USE_LSB_TAG not only requires the least 3 bits of pointers returned by
   malloc to be 0 but also needs to be able to impose a mult-of-8 alignment
   on the few static Lisp_Objects used: all the defsubr as well
   as the two special buffers buffer_defaults and buffer_local_symbols.  */
324 325 326 327

/* First, try and define DECL_ALIGN(type,var) which declares a static
   variable VAR of type TYPE with the added requirement that it be
   TYPEBITS-aligned. */
328 329
#ifndef NO_DECL_ALIGN
# ifndef DECL_ALIGN
330
/* What compiler directive should we use for non-gcc compilers?  -stef  */
331 332 333 334
#  if defined (__GNUC__)
#   define DECL_ALIGN(type, var) \
     type __attribute__ ((__aligned__ (1 << GCTYPEBITS))) var
#  endif
335
# endif
336 337
#endif

338 339 340 341 342 343 344 345 346 347 348
/* Let's USE_LSB_TAG on systems where we know malloc returns mult-of-8.  */
#if defined GNU_MALLOC || defined DOUG_LEA_MALLOC || defined __GLIBC__ || defined MAC_OSX
/* We also need to be able to specify mult-of-8 alignment on static vars.  */
# if defined DECL_ALIGN
/* We currently do not support USE_LSB_TAG with a union Lisp_Object.  */
#  if defined NO_UNION_TYPE
#   define USE_LSB_TAG
#  endif
# endif
#endif

349
/* If we cannot use 8-byte alignment, make DECL_ALIGN a no-op.  */
350 351 352 353 354
#ifndef DECL_ALIGN
# ifdef USE_LSB_TAG
#  error "USE_LSB_TAG used without defining DECL_ALIGN"
# endif
# define DECL_ALIGN(type, var) type var
355 356
#endif

Jim Blandy's avatar
Jim Blandy committed
357 358 359

/* These macros extract various sorts of values from a Lisp_Object.
 For example, if tem is a Lisp_Object whose type is Lisp_Cons,
360
 XCONS (tem) is the struct Lisp_Cons * pointing to the memory for that cons.  */
Jim Blandy's avatar
Jim Blandy committed
361 362 363

#ifdef NO_UNION_TYPE

364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384
#ifdef USE_LSB_TAG

#define TYPEMASK ((((EMACS_INT) 1) << GCTYPEBITS) - 1)
#define XTYPE(a) ((enum Lisp_Type) (((EMACS_UINT) (a)) & TYPEMASK))
#define XINT(a) (((EMACS_INT) (a)) >> GCTYPEBITS)
#define XUINT(a) (((EMACS_UINT) (a)) >> GCTYPEBITS)
#define XSET(var, type, ptr)					\
    (eassert (XTYPE (ptr) == 0), /* Check alignment.  */	\
     (var) = ((EMACS_INT) (type)) | ((EMACS_INT) (ptr)))
#define make_number(N) (((EMACS_INT) (N)) << GCTYPEBITS)

/* XFASTINT and XSETFASTINT are for use when the integer is known to be
   positive, in which case the implementation can sometimes be faster
   depending on the tagging scheme.  With USE_LSB_TAG, there's no benefit.  */
#define XFASTINT(a) XINT (a)
#define XSETFASTINT(a, b) ((a) = make_number (b))

#define XPNTR(a) ((EMACS_INT) ((a) & ~TYPEMASK))

#else  /* not USE_LSB_TAG */

385 386
#define VALMASK ((((EMACS_INT) 1) << VALBITS) - 1)

Jim Blandy's avatar
Jim Blandy committed
387 388
/* One need to override this if there must be high bits set in data space
   (doing the result of the below & ((1 << (GCTYPE + 1)) - 1) would work
389
    on all machines, but would penalize machines which don't need it)
Jim Blandy's avatar
Jim Blandy committed
390
 */
391
#define XTYPE(a) ((enum Lisp_Type) (((EMACS_UINT) (a)) >> VALBITS))
Jim Blandy's avatar
Jim Blandy committed
392

Karl Heuer's avatar
Karl Heuer committed
393 394
/* For integers known to be positive, XFASTINT provides fast retrieval
   and XSETFASTINT provides fast storage.  This takes advantage of the
395
   fact that Lisp_Int is 0.  */
396
#define XFASTINT(a) ((a) + 0)
Karl Heuer's avatar
Karl Heuer committed
397
#define XSETFASTINT(a, b) ((a) = (b))
Jim Blandy's avatar
Jim Blandy committed
398 399 400 401

/* Extract the value of a Lisp_Object as a signed integer.  */

#ifndef XINT   /* Some machines need to do this differently.  */
402 403
#define XINT(a) ((((EMACS_INT) (a)) << (BITS_PER_EMACS_INT - VALBITS))	\
		 >> (BITS_PER_EMACS_INT - VALBITS))
Jim Blandy's avatar
Jim Blandy committed
404 405 406 407 408 409
#endif

/* Extract the value as an unsigned integer.  This is a basis
   for extracting it as a pointer to a structure in storage.  */

#ifndef XUINT
410
#define XUINT(a) ((EMACS_UINT) ((a) & VALMASK))
Jim Blandy's avatar
Jim Blandy committed
411 412 413 414
#endif

#ifndef XSET
#define XSET(var, type, ptr) \
415
   ((var) = ((EMACS_INT)(type) << VALBITS) + ((EMACS_INT) (ptr) & VALMASK))
Jim Blandy's avatar
Jim Blandy committed
416 417
#endif

418 419 420 421 422
/* Convert a C integer into a Lisp_Object integer.  */

#define make_number(N)		\
  ((((EMACS_INT) (N)) & VALMASK) | ((EMACS_INT) Lisp_Int) << VALBITS)

423 424
#endif /* not USE_LSB_TAG */

425
#define EQ(x, y) ((x) == (y))
Jim Blandy's avatar
Jim Blandy committed
426

427
#else /* not NO_UNION_TYPE */
Jim Blandy's avatar
Jim Blandy committed
428 429 430

#define XTYPE(a) ((enum Lisp_Type) (a).u.type)

Karl Heuer's avatar
Karl Heuer committed
431 432 433
/* For integers known to be positive, XFASTINT provides fast retrieval
   and XSETFASTINT provides fast storage.  This takes advantage of the
   fact that Lisp_Int is 0.  */
434
#define XFASTINT(a) ((a).i + 0)
Karl Heuer's avatar
Karl Heuer committed
435
#define XSETFASTINT(a, b) ((a).i = (b))
Jim Blandy's avatar
Jim Blandy committed
436 437 438

#ifdef EXPLICIT_SIGN_EXTEND
/* Make sure we sign-extend; compilers have been known to fail to do so.  */
439
#define XINT(a) (((a).s.val << (BITS_PER_EMACS_INT - VALBITS)) \
440
		 >> (BITS_PER_EMACS_INT - VALBITS))
Jim Blandy's avatar
Jim Blandy committed
441 442 443 444 445 446 447
#else
#define XINT(a) ((a).s.val)
#endif /* EXPLICIT_SIGN_EXTEND */

#define XUINT(a) ((a).u.val)

#define XSET(var, vartype, ptr) \
448
   (((var).s.val = ((EMACS_INT) (ptr))), ((var).s.type = ((char) (vartype))))
Jim Blandy's avatar
Jim Blandy committed
449

450 451 452 453
#if __GNUC__ >= 2 && defined (__OPTIMIZE__)
#define make_number(N) \
  (__extension__ ({ Lisp_Object _l; _l.s.val = (N); _l.s.type = Lisp_Int; _l; }))
#else
454
extern Lisp_Object make_number P_ ((EMACS_INT));
455
#endif
456

457
#define EQ(x, y) ((x).i == (y).i)
458

Stefan Monnier's avatar
Stefan Monnier committed
459 460
#endif /* NO_UNION_TYPE */

Jim Blandy's avatar
Jim Blandy committed
461
/* During garbage collection, XGCTYPE must be used for extracting types
Stefan Monnier's avatar
Stefan Monnier committed
462
 so that the mark bit is ignored.  XMARKBIT accesses the markbit.
Jim Blandy's avatar
Jim Blandy committed
463 464 465 466
 Markbits are used only in particular slots of particular structure types.
 Other markbits are always zero.
 Outside of garbage collection, all mark bits are always zero.  */

Stefan Monnier's avatar
Stefan Monnier committed
467 468
#ifndef XGCTYPE
/* The distinction does not exist now that the MARKBIT has been eliminated.  */
469
#define XGCTYPE(a) XTYPE (a)
Stefan Monnier's avatar
Stefan Monnier committed
470
#endif
Jim Blandy's avatar
Jim Blandy committed
471

472 473 474 475 476 477 478 479 480 481 482 483 484 485 486
#ifndef XPNTR
#ifdef HAVE_SHM
/* In this representation, data is found in two widely separated segments.  */
extern size_t pure_size;
#define XPNTR(a) \
  (XUINT (a) | (XUINT (a) > pure_size ? DATA_SEG_BITS : PURE_SEG_BITS))
#else /* not HAVE_SHM */
#ifdef DATA_SEG_BITS
/* This case is used for the rt-pc.
   In the diffs I was given, it checked for ptr = 0
   and did not adjust it in that case.
   But I don't think that zero should ever be found
   in a Lisp object whose data type says it points to something.  */
#define XPNTR(a) (XUINT (a) | DATA_SEG_BITS)
#else
487 488 489 490 491
/* Some versions of gcc seem to consider the bitfield width when
   issuing the "cast to pointer from integer of different size"
   warning, so the cast is here to widen the value back to its natural
   size.  */
#define XPNTR(a) ((EMACS_INT) XUINT (a))
492 493 494 495
#endif
#endif /* not HAVE_SHM */
#endif /* no XPNTR */

Gerd Moellmann's avatar
Gerd Moellmann committed
496 497
/* Largest and smallest representable fixnum values.  These are the C
   values.  */
498

Gerd Moellmann's avatar
Gerd Moellmann committed
499 500
#define MOST_NEGATIVE_FIXNUM	- ((EMACS_INT) 1 << (VALBITS - 1))
#define MOST_POSITIVE_FIXNUM	(((EMACS_INT) 1 << (VALBITS - 1)) - 1)
501 502 503
/* Mask indicating the significant bits of a Lisp_Int.
   I.e. (x & INTMASK) == XUINT (make_number (x)).  */
#define INTMASK ((((EMACS_INT) 1) << VALBITS) - 1)
504 505 506 507

/* Value is non-zero if C integer I doesn't fit into a Lisp fixnum.  */

#define FIXNUM_OVERFLOW_P(i) \
508 509
  ((EMACS_INT)(i) > MOST_POSITIVE_FIXNUM \
   || (EMACS_INT) (i) < MOST_NEGATIVE_FIXNUM)
510

511
/* Extract a value or address from a Lisp_Object.  */
Jim Blandy's avatar
Jim Blandy committed
512

513
#define XCONS(a) (eassert (GC_CONSP(a)),(struct Lisp_Cons *) XPNTR(a))
514
#define XVECTOR(a) (eassert (GC_VECTORLIKEP(a)),(struct Lisp_Vector *) XPNTR(a))
515 516 517
#define XSTRING(a) (eassert (GC_STRINGP(a)),(struct Lisp_String *) XPNTR(a))
#define XSYMBOL(a) (eassert (GC_SYMBOLP(a)),(struct Lisp_Symbol *) XPNTR(a))
#define XFLOAT(a) (eassert (GC_FLOATP(a)),(struct Lisp_Float *) XPNTR(a))
518 519

/* Misc types.  */
520

521
#define XMISC(a)   ((union Lisp_Misc *) XPNTR(a))
Richard M. Stallman's avatar
Richard M. Stallman committed
522
#define XMISCTYPE(a)   (XMARKER (a)->type)
523
#define XMARKER(a) (&(XMISC(a)->u_marker))
524 525 526 527
#define XINTFWD(a) (&(XMISC(a)->u_intfwd))
#define XBOOLFWD(a) (&(XMISC(a)->u_boolfwd))
#define XOBJFWD(a) (&(XMISC(a)->u_objfwd))
#define XBUFFER_OBJFWD(a) (&(XMISC(a)->u_buffer_objfwd))
528
#define XBUFFER_LOCAL_VALUE(a) (&(XMISC(a)->u_buffer_local_value))
529
#define XOVERLAY(a) (&(XMISC(a)->u_overlay))
530
#define XKBOARD_OBJFWD(a) (&(XMISC(a)->u_kboard_objfwd))
531
#define XSAVE_VALUE(a) (&(XMISC(a)->u_save_value))
Jim Blandy's avatar
Jim Blandy committed
532

533
/* Pseudovector types.  */
534

535 536 537 538
#define XPROCESS(a) (eassert (GC_PROCESSP(a)),(struct Lisp_Process *) XPNTR(a))
#define XWINDOW(a) (eassert (GC_WINDOWP(a)),(struct window *) XPNTR(a))
#define XSUBR(a) (eassert (GC_SUBRP(a)),(struct Lisp_Subr *) XPNTR(a))
#define XBUFFER(a) (eassert (GC_BUFFERP(a)),(struct buffer *) XPNTR(a))
539 540
#define XCHAR_TABLE(a) ((struct Lisp_Char_Table *) XPNTR(a))
#define XBOOL_VECTOR(a) ((struct Lisp_Bool_Vector *) XPNTR(a))
541 542

/* Construct a Lisp_Object from a value or address.  */
543

544
#define XSETINT(a, b) (a) = make_number (b)
545
#define XSETCONS(a, b) XSET (a, Lisp_Cons, b)
546
#define XSETVECTOR(a, b) XSET (a, Lisp_Vectorlike, b)
547 548 549
#define XSETSTRING(a, b) XSET (a, Lisp_String, b)
#define XSETSYMBOL(a, b) XSET (a, Lisp_Symbol, b)
#define XSETFLOAT(a, b) XSET (a, Lisp_Float, b)
550 551

/* Misc types.  */
552

553
#define XSETMISC(a, b) XSET (a, Lisp_Misc, b)
Richard M. Stallman's avatar
Richard M. Stallman committed
554
#define XSETMARKER(a, b) (XSETMISC (a, b), XMISCTYPE (a) = Lisp_Misc_Marker)
555 556

/* Pseudovector types.  */
557

558 559 560 561 562 563 564 565
#define XSETPSEUDOVECTOR(a, b, code) \
  (XSETVECTOR (a, b), XVECTOR (a)->size |= PSEUDOVECTOR_FLAG | (code))
#define XSETWINDOW_CONFIGURATION(a, b) \
  (XSETPSEUDOVECTOR (a, b, PVEC_WINDOW_CONFIGURATION))
#define XSETPROCESS(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_PROCESS))
#define XSETWINDOW(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_WINDOW))
#define XSETSUBR(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_SUBR))
#define XSETCOMPILED(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_COMPILED))
566
#define XSETBUFFER(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_BUFFER))
567 568
#define XSETCHAR_TABLE(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_CHAR_TABLE))
#define XSETBOOL_VECTOR(a, b) (XSETPSEUDOVECTOR (a, b, PVEC_BOOL_VECTOR))
569 570 571 572 573 574 575

/* Convenience macros for dealing with Lisp arrays.  */

#define AREF(ARRAY, IDX)	XVECTOR ((ARRAY))->contents[IDX]
#define ASET(ARRAY, IDX, VAL)	(AREF ((ARRAY), (IDX)) = (VAL))
#define ASIZE(ARRAY)		XVECTOR ((ARRAY))->size

576 577
/* Convenience macros for dealing with Lisp strings.  */

Ken Raeburn's avatar
Ken Raeburn committed
578 579
#define SREF(string, index)	(XSTRING (string)->data[index] + 0)
#define SSET(string, index, new) (XSTRING (string)->data[index] = (new))
Ken Raeburn's avatar
Ken Raeburn committed
580
#define SDATA(string)		(XSTRING (string)->data + 0)
581 582 583 584 585
#define SCHARS(string)		(XSTRING (string)->size + 0)
#define SBYTES(string)		(STRING_BYTES (XSTRING (string)) + 0)

#define STRING_SET_CHARS(string, newsize) \
    (XSTRING (string)->size = (newsize))
586

Ken Raeburn's avatar
Ken Raeburn committed
587 588 589
#define STRING_COPYIN(string, index, new, count) \
    bcopy (new, XSTRING (string)->data + index, count)

Jim Blandy's avatar
Jim Blandy committed
590

591
/* See the macros in intervals.h.  */
592 593 594 595

typedef struct interval *INTERVAL;

/* Complain if object is not string or buffer type */
596
#define CHECK_STRING_OR_BUFFER(x) \
597
  { if (!STRINGP ((x)) && !BUFFERP ((x))) \
598 599
      x = wrong_type_argument (Qbuffer_or_string_p, (x)); }

Jim Blandy's avatar
Jim Blandy committed
600 601 602 603
/* In a cons, the markbit of the car is the gc mark bit */

struct Lisp_Cons
  {
604 605 606
    /* Please do not use the names of these elements in code other
       than the core lisp implementation.  Use XCAR and XCDR below.  */
#ifdef HIDE_LISP_IMPLEMENTATION
607 608 609 610 611 612
    Lisp_Object car_;
    union
    {
      Lisp_Object cdr_;
      struct Lisp_Cons *chain;
    } u;
613
#else
614 615 616 617 618 619
    Lisp_Object car;
    union
    {
      Lisp_Object cdr;
      struct Lisp_Cons *chain;
    } u;
620
#endif
Jim Blandy's avatar
Jim Blandy committed
621 622
  };

623
/* Take the car or cdr of something known to be a cons cell.  */
624 625 626 627 628 629
/* The _AS_LVALUE macros shouldn't be used outside of the minimal set
   of code that has to know what a cons cell looks like.  Other code not
   part of the basic lisp implementation should assume that the car and cdr
   fields are not accessible as lvalues.  (What if we want to switch to
   a copying collector someday?  Cached cons cell field addresses may be
   invalidated at arbitrary points.)  */
630
#ifdef HIDE_LISP_IMPLEMENTATION
631
#define XCAR_AS_LVALUE(c) (XCONS ((c))->car_)
632
#define XCDR_AS_LVALUE(c) (XCONS ((c))->u.cdr_)
633
#else
634
#define XCAR_AS_LVALUE(c) (XCONS ((c))->car)
635
#define XCDR_AS_LVALUE(c) (XCONS ((c))->u.cdr)
636
#endif
637

638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655
/* Use these from normal code.  */
#define XCAR(c)	LISP_MAKE_RVALUE(XCAR_AS_LVALUE(c))
#define XCDR(c) LISP_MAKE_RVALUE(XCDR_AS_LVALUE(c))

/* Use these to set the fields of a cons cell.

   Note that both arguments may refer to the same object, so 'n'
   should not be read after 'c' is first modified.  Also, neither
   argument should be evaluated more than once; side effects are
   especially common in the second argument.  */
#define XSETCAR(c,n) (XCAR_AS_LVALUE(c) = (n))
#define XSETCDR(c,n) (XCDR_AS_LVALUE(c) = (n))

/* For performance: Fast storage of positive integers into the
   fields of a cons cell.  See above caveats.  */
#define XSETCARFASTINT(c,n)  XSETFASTINT(XCAR_AS_LVALUE(c),(n))
#define XSETCDRFASTINT(c,n)  XSETFASTINT(XCDR_AS_LVALUE(c),(n))

656 657 658 659 660 661 662 663 664 665 666
/* Take the car or cdr of something whose type is not known.  */
#define CAR(c)					\
 (CONSP ((c)) ? XCAR ((c))			\
  : NILP ((c)) ? Qnil				\
  : wrong_type_argument (Qlistp, (c)))

#define CDR(c)					\
 (CONSP ((c)) ? XCDR ((c))			\
  : NILP ((c)) ? Qnil				\
  : wrong_type_argument (Qlistp, (c)))

Kenichi Handa's avatar
Kenichi Handa committed
667 668 669 670 671
/* Nonzero if STR is a multibyte string.  */
#define STRING_MULTIBYTE(STR)  \
  (XSTRING (STR)->size_byte >= 0)

/* Return the length in bytes of STR.  */
672 673 674 675 676 677 678 679 680

#ifdef GC_CHECK_STRING_BYTES

struct Lisp_String;
extern int string_bytes P_ ((struct Lisp_String *));
#define STRING_BYTES(S) string_bytes ((S))

#else /* not GC_CHECK_STRING_BYTES */

Kenichi Handa's avatar
Kenichi Handa committed
681 682 683
#define STRING_BYTES(STR)  \
  ((STR)->size_byte < 0 ? (STR)->size : (STR)->size_byte)

684 685
#endif /* not GC_CHECK_STRING_BYTES */

686 687 688 689
/* Mark STR as a unibyte string.  */
#define STRING_SET_UNIBYTE(STR)      (XSTRING (STR)->size_byte = -1)

/* Get text properties.  */
690 691 692 693
#define STRING_INTERVALS(STR)  (XSTRING (STR)->intervals + 0)

/* Set text properties.  */
#define STRING_SET_INTERVALS(STR, INT) (XSTRING (STR)->intervals = (INT))
Kenichi Handa's avatar
Kenichi Handa committed
694

Jim Blandy's avatar
Jim Blandy committed
695 696 697 698
/* In a string or vector, the sign bit of the `size' is the gc mark bit */

struct Lisp_String
  {
699
    EMACS_INT size;
700
    EMACS_INT size_byte;
701
    INTERVAL intervals;		/* text properties in this string */
702
    unsigned char *data;
Jim Blandy's avatar
Jim Blandy committed
703 704
  };

Karl Heuer's avatar
Karl Heuer committed
705
/* If a struct is made to look like a vector, this macro returns the length
706 707 708 709
   of the shortest vector that would hold that struct.  */
#define VECSIZE(type) ((sizeof (type) - (sizeof (struct Lisp_Vector)  \
                                         - sizeof (Lisp_Object))      \
                        + sizeof(Lisp_Object) - 1) /* round up */     \
Karl Heuer's avatar
Karl Heuer committed
710 711
		       / sizeof (Lisp_Object))

Jim Blandy's avatar
Jim Blandy committed
712 713
struct Lisp_Vector
  {
714
    EMACS_INT size;
Jim Blandy's avatar
Jim Blandy committed
715 716 717 718
    struct Lisp_Vector *next;
    Lisp_Object contents[1];
  };

719 720 721 722 723 724 725 726 727 728
/* A char table is a kind of vectorlike, with contents are like a
   vector but with a few other slots.  For some purposes, it makes
   sense to handle a chartable with type struct Lisp_Vector.  An
   element of a char table can be any Lisp objects, but if it is a sub
   char-table, we treat it a table that contains information of a
   group of characters of the same charsets or a specific character of
   a charset.  A sub char-table has the same structure as a char table
   except for that the former omits several slots at the tail.  A sub
   char table appears only in an element of a char table, and there's
   no way to access it directly from Emacs Lisp program.  */
729

730 731
/* This is the number of slots that apply to characters or character
   sets.  The first 128 are for ASCII, the next 128 are for 8-bit
732 733 734
   European characters, and the last 128 are for multibyte characters.
   The first 256 are indexed by the code itself, but the last 128 are
   indexed by (charset-id + 128).  */
735 736
#define CHAR_TABLE_ORDINARY_SLOTS 384

737 738 739 740 741 742 743 744
/* These are the slot of the default values for single byte
   characters.  As 0x9A is never be a charset-id, it is safe to use
   that slot for ASCII.  0x9E and 0x80 are charset-ids of
   eight-bit-control and eight-bit-graphic respectively.  */
#define CHAR_TABLE_DEFAULT_SLOT_ASCII (0x9A + 128)
#define CHAR_TABLE_DEFAULT_SLOT_8_BIT_CONTROL (0x9E + 128)
#define CHAR_TABLE_DEFAULT_SLOT_8_BIT_GRAPHIC (0x80 + 128)

745 746 747
/* This is the number of slots that apply to characters of ASCII and
   8-bit Europeans only.  */
#define CHAR_TABLE_SINGLE_BYTE_SLOTS 256
748

749 750 751 752 753 754 755 756 757 758 759 760
/* This is the number of slots that every char table must have.  This
   counts the ordinary slots and the top, defalt, parent, and purpose
   slots.  */
#define CHAR_TABLE_STANDARD_SLOTS (CHAR_TABLE_ORDINARY_SLOTS + 4)

/* This is the number of slots that apply to position-code-1 and
   position-code-2 of a multibyte character at the 2nd and 3rd level
   sub char tables respectively.  */
#define SUB_CHAR_TABLE_ORDINARY_SLOTS 128

/* This is the number of slots that every sub char table must have.
   This counts the ordinary slots and the top and defalt slot.  */
761
#define SUB_CHAR_TABLE_STANDARD_SLOTS (SUB_CHAR_TABLE_ORDINARY_SLOTS + 2)
762 763 764 765 766 767

/* Return the number of "extra" slots in the char table CT.  */

#define CHAR_TABLE_EXTRA_SLOTS(CT)	\
  (((CT)->size & PSEUDOVECTOR_SIZE_MASK) - CHAR_TABLE_STANDARD_SLOTS)

768
/* Almost equivalent to Faref (CT, IDX) with optimization for ASCII
769 770 771
   and 8-bit Europeans characters.  For these characters, do not check
   validity of CT.  Do not follow parent.  */
#define CHAR_TABLE_REF(CT, IDX)				\
772
  ((IDX) >= 0 && (IDX) < CHAR_TABLE_SINGLE_BYTE_SLOTS	\
773 774
   ? (!NILP (XCHAR_TABLE (CT)->contents[IDX])		\
      ? XCHAR_TABLE (CT)->contents[IDX]			\
775
      : XCHAR_TABLE (CT)->defalt)			\
776
   : Faref (CT, make_number (IDX)))
777

778 779 780 781 782 783 784 785 786 787 788 789 790
/* Almost equivalent to Faref (CT, IDX) with optimization for ASCII
   and 8-bit Europeans characters.  However, if the result is nil,
   return IDX.

   For these characters, do not check validity of CT
   and do not follow parent.  */
#define CHAR_TABLE_TRANSLATE(CT, IDX)			\
  ((IDX) < CHAR_TABLE_SINGLE_BYTE_SLOTS			\
   ? (!NILP (XCHAR_TABLE (CT)->contents[IDX])		\
      ? XINT (XCHAR_TABLE (CT)->contents[IDX])		\
      : IDX)						\
   : char_table_translate (CT, IDX))

791
/* Equivalent to Faset (CT, IDX, VAL) with optimization for ASCII and
792 793 794 795 796 797 798
   8-bit Europeans characters.  Do not check validity of CT.  */
#define CHAR_TABLE_SET(CT, IDX, VAL)			\
  do {							\
    if (XFASTINT (IDX) < CHAR_TABLE_SINGLE_BYTE_SLOTS)	\
      XCHAR_TABLE (CT)->contents[XFASTINT (IDX)] = VAL;	\
    else						\
      Faset (CT, IDX, VAL);				\
799 800
  } while (0)

801 802 803 804
struct Lisp_Char_Table
  {
    /* This is the vector's size field, which also holds the
       pseudovector type information.  It holds the size, too.
805 806
       The size counts the top, defalt, purpose, and parent slots.
       The last three are not counted if this is a sub char table.  */
807 808
    EMACS_INT size;
    struct Lisp_Vector *next;
809 810 811
    /* This holds a flag to tell if this is a top level char table (t)
       or a sub char table (nil).  */
    Lisp_Object top;
812 813 814
    /* This holds a default value,
       which is used whenever the value for a specific character is nil.  */
    Lisp_Object defalt;
815 816 817 818 819 820
    /* This holds an actual value of each element.  A sub char table
       has only SUB_CHAR_TABLE_ORDINARY_SLOTS number of elements.  */
    Lisp_Object contents[CHAR_TABLE_ORDINARY_SLOTS];

    /* A sub char table doesn't has the following slots.  */

821 822 823 824
    /* This points to another char table, which we inherit from
       when the value for a specific character is nil.
       The `defalt' slot takes precedence over this.  */
    Lisp_Object parent;
825 826 827 828
    /* This should be a symbol which says what kind of use
       this char-table is meant for.
       Typically now the values can be `syntax-table' and `display-table'.  */
    Lisp_Object purpose;
829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845
    /* These hold additional data.  */
    Lisp_Object extras[1];
  };

/* A boolvector is a kind of vectorlike, with contents are like a string.  */
struct Lisp_Bool_Vector
  {
    /* This is the vector's size field.  It doesn't have the real size,
       just the subtype information.  */
    EMACS_INT vector_size;
    struct Lisp_Vector *next;
    /* This is the size in bits.  */
    EMACS_INT size;
    /* This contains the actual bits, packed into bytes.  */
    unsigned char data[1];
  };

846 847 848 849 850 851 852
/* This structure describes a built-in function.
   It is generated by the DEFUN macro only.
   defsubr makes it into a Lisp object.

   This type is treated in most respects as a pseudovector,
   but since we never dynamically allocate or free them,
   we don't need a next-vector field.  */
853

Jim Blandy's avatar
Jim Blandy committed
854 855
struct Lisp_Subr
  {
856
    EMACS_INT size;
Jim Blandy's avatar
Jim Blandy committed
857 858 859 860 861 862
    Lisp_Object (*function) ();
    short min_args, max_args;
    char *symbol_name;
    char *prompt;
    char *doc;
  };
Gerd Moellmann's avatar
Gerd Moellmann committed
863

864 865 866 867 868 869 870 871 872 873 874 875 876 877 878 879 880 881

/***********************************************************************
			       Symbols
 ***********************************************************************/

/* Interned state of a symbol.  */

enum symbol_interned
{
  SYMBOL_UNINTERNED = 0,
  SYMBOL_INTERNED = 1,
  SYMBOL_INTERNED_IN_INITIAL_OBARRAY = 2
};

/* In a symbol, the markbit of the plist is used as the gc mark bit */

struct Lisp_Symbol
{
882 883
  unsigned gcmarkbit : 1;

884 885 886 887 888 889 890 891 892 893 894 895
  /* Non-zero means symbol serves as a variable alias.  The symbol
     holding the real value is found in the value slot.  */
  unsigned indirect_variable : 1;

  /* Non-zero means symbol is constant, i.e. changing its value
     should signal an error.  */
  unsigned constant : 1;

  /* Interned state of the symbol.  This is an enumerator from
     enum symbol_interned.  */
  unsigned interned : 2;

896 897 898 899 900
  /* The symbol's name, as a Lisp string.

     The name "xname" is used to intentionally break code referring to
     the old field "name" of type pointer to struct Lisp_String.  */
  Lisp_Object xname;
901 902 903 904 905 906 907

  /* Value of the symbol or Qunbound if unbound.  If this symbol is a
     defvaralias, `value' contains the symbol for which it is an
     alias.  Use the SYMBOL_VALUE and SET_SYMBOL_VALUE macros to get
     and set a symbol's value, to take defvaralias into account.  */
  Lisp_Object value;

908
  /* Function value of the symbol or Qunbound if not fboundp.  */
909 910 911 912
  Lisp_Object function;

  /* The symbol's property list.  */
  Lisp_Object plist;
913

914 915 916 917
  /* Next symbol in obarray bucket, if the symbol is interned.  */
  struct Lisp_Symbol *next;
};

918 919 920 921 922
/* Value is name of symbol.  */

#define SYMBOL_NAME(sym)  \
     LISP_MAKE_RVALUE (XSYMBOL (sym)->xname)

923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955
/* Value is non-zero if SYM is an interned symbol.  */

#define SYMBOL_INTERNED_P(sym)  \
     (XSYMBOL (sym)->interned != SYMBOL_UNINTERNED)

/* Value is non-zero if SYM is interned in initial_obarray.  */

#define SYMBOL_INTERNED_IN_INITIAL_OBARRAY_P(sym) \
     (XSYMBOL (sym)->interned == SYMBOL_INTERNED_IN_INITIAL_OBARRAY)

/* Value is non-zero if symbol is considered a constant, i.e. its
   value cannot be changed (there is an exception for keyword symbols,
   whose value can be set to the keyword symbol itself).  */

#define SYMBOL_CONSTANT_P(sym)   XSYMBOL (sym)->constant

/* Value is the value of SYM, with defvaralias taken into
   account.  */

#define SYMBOL_VALUE(sym)			\
   (XSYMBOL (sym)->indirect_variable		\
    ? XSYMBOL (indirect_variable (sym))->value	\
    : XSYMBOL (sym)->value)

/* Set SYM's value to VAL, taking defvaralias into account.  */

#define SET_SYMBOL_VALUE(sym, val)				\
     do {							\
       if (XSYMBOL (sym)->indirect_variable)			\
	 XSYMBOL (indirect_variable ((sym)))->value = (val);	\
       else							\
	 XSYMBOL (sym)->value = (val);				\
     } while (0)
956

Gerd Moellmann's avatar
Gerd Moellmann committed
957 958 959 960 961 962 963 964 965 966 967 968

/***********************************************************************
			     Hash Tables
 ***********************************************************************/

/* The structure of a Lisp hash table.  */

struct Lisp_Hash_Table
{
  /* Vector fields.  The hash table code doesn't refer to these.  */
  EMACS_INT size;
  struct Lisp_Vector *vec_next;
969

Gerd Moellmann's avatar
Gerd Moellmann committed
970 971 972 973 974 975
  /* Function used to compare keys.  */
  Lisp_Object test;

  /* Nil if table is non-weak.  Otherwise a symbol describing the
     weakness of the table.  */
  Lisp_Object weak;
976

Gerd Moellmann's avatar
Gerd Moellmann committed
977 978 979 980 981 982 983 984 985 986 987 988 989 990 991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037
  /* When the table is resized, and this is an integer, compute the
     new size by adding this to the old size.  If a float, compute the
     new size by multiplying the old size with this factor.  */
  Lisp_Object rehash_size;

  /* Resize hash table when number of entries/ table size is >= this
     ratio, a float.  */
  Lisp_Object rehash_threshold;

  /* Number of key/value entries in the table.  */
  Lisp_Object count;

  /* Vector of keys and values.  The key of item I is found at index
     2 * I, the value is found at index 2 * I + 1.  */
  Lisp_Object key_and_value;

  /* Vector of hash codes.. If hash[I] is nil, this means that that
     entry I is unused.  */
  Lisp_Object hash;

  /* Vector used to chain entries.  If entry I is free, next[I] is the
     entry number of the next free item.  If entry I is non-free,
     next[I] is the index of the next entry in the collision chain.  */
  Lisp_Object next;

  /* Index of first free entry in free list.  */
  Lisp_Object next_free;

  /* Bucket vector.  A non-nil entry is the index of the first item in
     a collision chain.  This vector's size can be larger than the
     hash table size to reduce collisions.  */
  Lisp_Object index;

  /* Next weak hash table if this is a weak hash table.  The head
     of the list is in Vweak_hash_tables.  */
  Lisp_Object next_weak;

  /* User-supplied hash function, or nil.  */
  Lisp_Object user_hash_function;

  /* User-supplied key comparison function, or nil.  */
  Lisp_Object user_cmp_function;

  /* C function to compare two keys.  */
  int (* cmpfn) P_ ((struct Lisp_Hash_Table *, Lisp_Object,
		     unsigned, Lisp_Object, unsigned));

  /* C function to compute hash code.  */
  unsigned (* hashfn) P_ ((struct Lisp_Hash_Table *, Lisp_Object));
};


#define XHASH_TABLE(OBJ) \
     ((struct Lisp_Hash_Table *) XPNTR (OBJ))

#define XSET_HASH_TABLE(VAR, PTR) \
     (XSETPSEUDOVECTOR (VAR, PTR, PVEC_HASH_TABLE))

#define HASH_TABLE_P(OBJ)  PSEUDOVECTORP (OBJ, PVEC_HASH_TABLE)
#define GC_HASH_TABLE_P(x) GC_PSEUDOVECTORP (x, PVEC_HASH_TABLE)

1038
#define CHECK_HASH_TABLE(x)					\
Gerd Moellmann's avatar
Gerd Moellmann committed
1039 1040 1041 1042 1043 1044 1045
     do								\
       {							\
	 if (!HASH_TABLE_P ((x)))				\
	   x = wrong_type_argument (Qhash_table_p, (x));	\
       }							\
     while (0)

1046 1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061 1062 1063 1064 1065 1066 1067 1068 1069 1070 1071
/* Value is the key part of entry IDX in hash table H.  */

#define HASH_KEY(H, IDX)   AREF ((H)->key_and_value, 2 * (IDX))

/* Value is the value part of entry IDX in hash table H.  */

#define HASH_VALUE(H, IDX) AREF ((H)->key_and_value, 2 * (IDX) + 1)

/* Value is the index of the next entry following the one at IDX
   in hash table H.  */

#define HASH_NEXT(H, IDX)  AREF ((H)->next, (IDX))

/* Value is the hash code computed for entry IDX in hash table H.  */

#define HASH_HASH(H, IDX)  AREF ((H)->hash, (IDX))

/* Value is the index of the element in hash table H that is the
   start of the collision list at index IDX in the index vector of H.  */

#define HASH_INDEX(H, IDX)  AREF ((H)->index, (IDX))

/* Value is the size of hash table H.  */

#define HASH_TABLE_SIZE(H) XVECTOR ((H)->next)->size

Gerd Moellmann's avatar
Gerd Moellmann committed
1072 1073 1074 1075 1076 1077 1078 1079 1080 1081 1082 1083 1084 1085
/* Default size for hash tables if not specified.  */

#define DEFAULT_HASH_SIZE 65

/* Default threshold specifying when to resize a hash table.  The
   value gives the ratio of current entries in the hash table and the
   size of the hash table.  */

#define DEFAULT_REHASH_THRESHOLD 0.8

/* Default factor by which to increase the size of a hash table.  */

#define DEFAULT_REHASH_SIZE 1.5

1086

1087 1088
/* These structures are used for various misc types.  */

Jim Blandy's avatar
Jim Blandy committed
1089
struct Lisp_Marker
1090 1091
{
  int type : 16;		/* = Lisp_Misc_Marker */
1092 1093
  unsigned gcmarkbit : 1;
  int spacer : 14;
1094 1095 1096
  /* 1 means normal insertion at the marker's position
     leaves the marker after the inserted text.  */
  unsigned int insertion_type : 1;
1097 1098
  /* This is the buffer that the marker points into,
     or 0 if it points nowhere.  */
1099
  struct buffer *buffer;
1100 1101 1102 1103 1104 1105

  /* The remaining fields are meaningless in a marker that
     does not point anywhere.  */

  /* For markers that point somewhere,
     this is used to chain of all the markers in a given buffer.  */
1106
  struct Lisp_Marker *next;
1107
  /* This is the char position where the marker points.  */
1108
  EMACS_INT charpos;
1109
  /* This is the byte position.  */
1110
  EMACS_INT bytepos;
1111
};