data.c 67 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Primitive operations on Lisp data types for GNU Emacs Lisp interpreter.
2
   Copyright (C) 1985, 86, 88, 93, 94, 95 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22

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 1, 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, 675 Mass Ave, Cambridge, MA 02139, USA.  */


#include <signal.h>

23
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
24
#include "lisp.h"
Jim Blandy's avatar
Jim Blandy committed
25
#include "puresize.h"
Jim Blandy's avatar
Jim Blandy committed
26 27 28 29 30

#ifndef standalone
#include "buffer.h"
#endif

Jim Blandy's avatar
Jim Blandy committed
31
#include "syssignal.h"
Jim Blandy's avatar
Jim Blandy committed
32

33
#ifdef MSDOS
Karl Heuer's avatar
Karl Heuer committed
34
/* These are redefined (correctly, but differently) in values.h.  */
35 36 37 38 39
#undef INTBITS
#undef LONGBITS
#undef SHORTBITS
#endif

Jim Blandy's avatar
Jim Blandy committed
40
#ifdef LISP_FLOAT_TYPE
41

42 43 44
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif
45 46 47 48 49 50 51 52 53 54 55

/* Work around a problem that happens because math.h on hpux 7
   defines two static variables--which, in Emacs, are not really static,
   because `static' is defined as nothing.  The problem is that they are
   here, in floatfns.c, and in lread.c.
   These macros prevent the name conflict.  */
#if defined (HPUX) && !defined (HPUX8)
#define _MAXLDBL data_c_maxldbl
#define _NMAXLDBL data_c_nmaxldbl
#endif

Jim Blandy's avatar
Jim Blandy committed
56 57 58
#include <math.h>
#endif /* LISP_FLOAT_TYPE */

59 60 61 62
#if !defined (atof)
extern double atof ();
#endif /* !atof */

Jim Blandy's avatar
Jim Blandy committed
63 64 65
Lisp_Object Qnil, Qt, Qquote, Qlambda, Qsubr, Qunbound;
Lisp_Object Qerror_conditions, Qerror_message, Qtop_level;
Lisp_Object Qerror, Qquit, Qwrong_type_argument, Qargs_out_of_range;
Jim Blandy's avatar
Jim Blandy committed
66
Lisp_Object Qvoid_variable, Qvoid_function, Qcyclic_function_indirection;
Jim Blandy's avatar
Jim Blandy committed
67 68
Lisp_Object Qsetting_constant, Qinvalid_read_syntax;
Lisp_Object Qinvalid_function, Qwrong_number_of_arguments, Qno_catch;
Roland McGrath's avatar
Roland McGrath committed
69
Lisp_Object Qend_of_file, Qarith_error, Qmark_inactive;
Jim Blandy's avatar
Jim Blandy committed
70
Lisp_Object Qbeginning_of_buffer, Qend_of_buffer, Qbuffer_read_only;
71
Lisp_Object Qintegerp, Qnatnump, Qwholenump, Qsymbolp, Qlistp, Qconsp;
Jim Blandy's avatar
Jim Blandy committed
72 73
Lisp_Object Qstringp, Qarrayp, Qsequencep, Qbufferp;
Lisp_Object Qchar_or_string_p, Qmarkerp, Qinteger_or_marker_p, Qvectorp;
Joseph Arceneaux's avatar
Joseph Arceneaux committed
74
Lisp_Object Qbuffer_or_string_p;
Jim Blandy's avatar
Jim Blandy committed
75
Lisp_Object Qboundp, Qfboundp;
76

Jim Blandy's avatar
Jim Blandy committed
77
Lisp_Object Qcdr;
78
Lisp_Object Qad_advice_info, Qad_activate;
Jim Blandy's avatar
Jim Blandy committed
79

80 81 82
Lisp_Object Qrange_error, Qdomain_error, Qsingularity_error;
Lisp_Object Qoverflow_error, Qunderflow_error;

Jim Blandy's avatar
Jim Blandy committed
83
#ifdef LISP_FLOAT_TYPE
84
Lisp_Object Qfloatp;
Jim Blandy's avatar
Jim Blandy committed
85 86 87
Lisp_Object Qnumberp, Qnumber_or_marker_p;
#endif

88 89 90 91
static Lisp_Object Qinteger, Qsymbol, Qstring, Qcons, Qmarker, Qoverlay;
static Lisp_Object Qfloat, Qwindow_configuration, Qprocess, Qwindow;
static Lisp_Object Qcompiled_function, Qbuffer, Qframe, Qvector;

Jim Blandy's avatar
Jim Blandy committed
92 93 94 95 96 97 98 99 100 101 102
static Lisp_Object swap_in_symval_forwarding ();

Lisp_Object
wrong_type_argument (predicate, value)
     register Lisp_Object predicate, value;
{
  register Lisp_Object tem;
  do
    {
      if (!EQ (Vmocklisp_arguments, Qt))
	{
103
	 if (STRINGP (value) &&
Jim Blandy's avatar
Jim Blandy committed
104
	     (EQ (predicate, Qintegerp) || EQ (predicate, Qinteger_or_marker_p)))
105
	   return Fstring_to_number (value);
106
	 if (INTEGERP (value) && EQ (predicate, Qstringp))
107
	   return Fnumber_to_string (value);
Jim Blandy's avatar
Jim Blandy committed
108
	}
109 110 111

      /* If VALUE is not even a valid Lisp object, abort here
	 where we can get a backtrace showing where it came from.  */
112
      if ((unsigned int) XGCTYPE (value) >= Lisp_Type_Limit)
113 114
	abort ();

Jim Blandy's avatar
Jim Blandy committed
115 116 117
      value = Fsignal (Qwrong_type_argument, Fcons (predicate, Fcons (value, Qnil)));
      tem = call1 (predicate, value);
    }
Jim Blandy's avatar
Jim Blandy committed
118
  while (NILP (tem));
Jim Blandy's avatar
Jim Blandy committed
119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147
  return value;
}

pure_write_error ()
{
  error ("Attempt to modify read-only object");
}

void
args_out_of_range (a1, a2)
     Lisp_Object a1, a2;
{
  while (1)
    Fsignal (Qargs_out_of_range, Fcons (a1, Fcons (a2, Qnil)));
}

void
args_out_of_range_3 (a1, a2, a3)
     Lisp_Object a1, a2, a3;
{
  while (1)
    Fsignal (Qargs_out_of_range, Fcons (a1, Fcons (a2, Fcons (a3, Qnil))));
}

Lisp_Object
make_number (num)
     int num;
{
  register Lisp_Object val;
148
  XSETINT (val, num);
Jim Blandy's avatar
Jim Blandy committed
149 150 151 152 153 154 155 156 157 158 159 160
  return val;
}

/* On some machines, XINT needs a temporary location.
   Here it is, in case it is needed.  */

int sign_extend_temp;

/* On a few machines, XINT can only be done by calling this.  */

int
sign_extend_lisp_int (num)
161
     EMACS_INT num;
Jim Blandy's avatar
Jim Blandy committed
162
{
163 164
  if (num & (((EMACS_INT) 1) << (VALBITS - 1)))
    return num | (((EMACS_INT) (-1)) << VALBITS);
Jim Blandy's avatar
Jim Blandy committed
165
  else
166
    return num & ((((EMACS_INT) 1) << VALBITS) - 1);
Jim Blandy's avatar
Jim Blandy committed
167 168 169 170 171 172 173 174 175 176 177 178 179 180 181
}

/* Data type predicates */

DEFUN ("eq", Feq, Seq, 2, 2, 0,
  "T if the two args are the same Lisp object.")
  (obj1, obj2)
     Lisp_Object obj1, obj2;
{
  if (EQ (obj1, obj2))
    return Qt;
  return Qnil;
}

DEFUN ("null", Fnull, Snull, 1, 1, 0, "T if OBJECT is nil.")
182 183
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
184
{
185
  if (NILP (object))
Jim Blandy's avatar
Jim Blandy committed
186 187 188 189
    return Qt;
  return Qnil;
}

190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211
DEFUN ("type-of", Ftype_of, Stype_of, 1, 1, 0,
  "Return a symbol representing the type of OBJECT.\n\
The symbol returned names the object's basic type;\n\
for example, (type-of 1) returns `integer'.")
  (object)
     Lisp_Object object;
{
  switch (XGCTYPE (object))
    {
    case Lisp_Int:
      return Qinteger;

    case Lisp_Symbol:
      return Qsymbol;

    case Lisp_String:
      return Qstring;

    case Lisp_Cons:
      return Qcons;

    case Lisp_Misc:
212
      switch (XMISCTYPE (object))
213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252
	{
	case Lisp_Misc_Marker:
	  return Qmarker;
	case Lisp_Misc_Overlay:
	  return Qoverlay;
	case Lisp_Misc_Float:
	  return Qfloat;
	}
      abort ();

    case Lisp_Vectorlike:
      if (GC_WINDOW_CONFIGURATIONP (object))
	return Qwindow_configuration;
      if (GC_PROCESSP (object))
	return Qprocess;
      if (GC_WINDOWP (object))
	return Qwindow;
      if (GC_SUBRP (object))
	return Qsubr;
      if (GC_COMPILEDP (object))
	return Qcompiled_function;
      if (GC_BUFFERP (object))
	return Qbuffer;

#ifdef MULTI_FRAME
      if (GC_FRAMEP (object))
	return Qframe;
#endif
      return Qvector;

#ifdef LISP_FLOAT_TYPE
    case Lisp_Float:
      return Qfloat;
#endif

    default:
      abort ();
    }
}

Jim Blandy's avatar
Jim Blandy committed
253
DEFUN ("consp", Fconsp, Sconsp, 1, 1, 0, "T if OBJECT is a cons cell.")
254 255
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
256
{
257
  if (CONSP (object))
Jim Blandy's avatar
Jim Blandy committed
258 259 260 261 262
    return Qt;
  return Qnil;
}

DEFUN ("atom", Fatom, Satom, 1, 1, 0, "T if OBJECT is not a cons cell.  This includes nil.")
263 264
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
265
{
266
  if (CONSP (object))
Jim Blandy's avatar
Jim Blandy committed
267 268 269 270 271
    return Qnil;
  return Qt;
}

DEFUN ("listp", Flistp, Slistp, 1, 1, 0, "T if OBJECT is a list.  This includes nil.")
272 273
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
274
{
275
  if (CONSP (object) || NILP (object))
Jim Blandy's avatar
Jim Blandy committed
276 277 278 279 280
    return Qt;
  return Qnil;
}

DEFUN ("nlistp", Fnlistp, Snlistp, 1, 1, 0, "T if OBJECT is not a list.  Lists include nil.")
281 282
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
283
{
284
  if (CONSP (object) || NILP (object))
Jim Blandy's avatar
Jim Blandy committed
285 286 287 288 289
    return Qnil;
  return Qt;
}

DEFUN ("symbolp", Fsymbolp, Ssymbolp, 1, 1, 0, "T if OBJECT is a symbol.")
290 291
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
292
{
293
  if (SYMBOLP (object))
Jim Blandy's avatar
Jim Blandy committed
294 295 296 297 298
    return Qt;
  return Qnil;
}

DEFUN ("vectorp", Fvectorp, Svectorp, 1, 1, 0, "T if OBJECT is a vector.")
299 300
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
301
{
302
  if (VECTORP (object))
Jim Blandy's avatar
Jim Blandy committed
303 304 305 306 307
    return Qt;
  return Qnil;
}

DEFUN ("stringp", Fstringp, Sstringp, 1, 1, 0, "T if OBJECT is a string.")
308 309
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
310
{
311
  if (STRINGP (object))
Jim Blandy's avatar
Jim Blandy committed
312 313 314 315 316
    return Qt;
  return Qnil;
}

DEFUN ("arrayp", Farrayp, Sarrayp, 1, 1, 0, "T if OBJECT is an array (string or vector).")
317 318
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
319
{
320
  if (VECTORP (object) || STRINGP (object))
Jim Blandy's avatar
Jim Blandy committed
321 322 323 324 325 326
    return Qt;
  return Qnil;
}

DEFUN ("sequencep", Fsequencep, Ssequencep, 1, 1, 0,
  "T if OBJECT is a sequence (list or array).")
327 328
  (object)
     register Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
329
{
330
  if (CONSP (object) || NILP (object) || VECTORP (object) || STRINGP (object))
Jim Blandy's avatar
Jim Blandy committed
331 332 333 334 335
    return Qt;
  return Qnil;
}

DEFUN ("bufferp", Fbufferp, Sbufferp, 1, 1, 0, "T if OBJECT is an editor buffer.")
336 337
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
338
{
339
  if (BUFFERP (object))
Jim Blandy's avatar
Jim Blandy committed
340 341 342 343 344
    return Qt;
  return Qnil;
}

DEFUN ("markerp", Fmarkerp, Smarkerp, 1, 1, 0, "T if OBJECT is a marker (editor pointer).")
345 346
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
347
{
348
  if (MARKERP (object))
Jim Blandy's avatar
Jim Blandy committed
349 350 351 352 353
    return Qt;
  return Qnil;
}

DEFUN ("subrp", Fsubrp, Ssubrp, 1, 1, 0, "T if OBJECT is a built-in function.")
354 355
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
356
{
357
  if (SUBRP (object))
Jim Blandy's avatar
Jim Blandy committed
358 359 360 361
    return Qt;
  return Qnil;
}

Jim Blandy's avatar
Jim Blandy committed
362 363
DEFUN ("byte-code-function-p", Fbyte_code_function_p, Sbyte_code_function_p,
       1, 1, 0, "T if OBJECT is a byte-compiled function object.")
364 365
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
366
{
367
  if (COMPILEDP (object))
Jim Blandy's avatar
Jim Blandy committed
368 369 370 371
    return Qt;
  return Qnil;
}

372 373
DEFUN ("char-or-string-p", Fchar_or_string_p, Schar_or_string_p, 1, 1, 0,
  "T if OBJECT is a character (an integer) or a string.")
374 375
  (object)
     register Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
376
{
377
  if (INTEGERP (object) || STRINGP (object))
Jim Blandy's avatar
Jim Blandy committed
378 379 380 381
    return Qt;
  return Qnil;
}

382
DEFUN ("integerp", Fintegerp, Sintegerp, 1, 1, 0, "T if OBJECT is an integer.")
383 384
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
385
{
386
  if (INTEGERP (object))
Jim Blandy's avatar
Jim Blandy committed
387 388 389 390
    return Qt;
  return Qnil;
}

391 392
DEFUN ("integer-or-marker-p", Finteger_or_marker_p, Sinteger_or_marker_p, 1, 1, 0,
  "T if OBJECT is an integer or a marker (editor pointer).")
393 394
  (object)
     register Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
395
{
396
  if (MARKERP (object) || INTEGERP (object))
Jim Blandy's avatar
Jim Blandy committed
397 398 399 400
    return Qt;
  return Qnil;
}

401 402
DEFUN ("natnump", Fnatnump, Snatnump, 1, 1, 0,
  "T if OBJECT is a nonnegative integer.")
403 404
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
405
{
406
  if (NATNUMP (object))
Jim Blandy's avatar
Jim Blandy committed
407 408 409 410 411 412
    return Qt;
  return Qnil;
}

DEFUN ("numberp", Fnumberp, Snumberp, 1, 1, 0,
       "T if OBJECT is a number (floating point or integer).")
413 414
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
415
{
416
  if (NUMBERP (object))
Jim Blandy's avatar
Jim Blandy committed
417
    return Qt;
Jim Blandy's avatar
Jim Blandy committed
418 419
  else
    return Qnil;
Jim Blandy's avatar
Jim Blandy committed
420 421 422 423 424
}

DEFUN ("number-or-marker-p", Fnumber_or_marker_p,
       Snumber_or_marker_p, 1, 1, 0,
       "T if OBJECT is a number or a marker.")
425 426
  (object)
     Lisp_Object object;
Jim Blandy's avatar
Jim Blandy committed
427
{
428
  if (NUMBERP (object) || MARKERP (object))
Jim Blandy's avatar
Jim Blandy committed
429 430 431
    return Qt;
  return Qnil;
}
432 433 434 435

#ifdef LISP_FLOAT_TYPE
DEFUN ("floatp", Ffloatp, Sfloatp, 1, 1, 0,
       "T if OBJECT is a floating point number.")
436 437
  (object)
     Lisp_Object object;
438
{
439
  if (FLOATP (object))
440 441 442
    return Qt;
  return Qnil;
}
Jim Blandy's avatar
Jim Blandy committed
443 444 445 446 447
#endif /* LISP_FLOAT_TYPE */

/* Extract and set components of lists */

DEFUN ("car", Fcar, Scar, 1, 1, 0,
448
  "Return the car of LIST.  If arg is nil, return nil.\n\
Jim Blandy's avatar
Jim Blandy committed
449 450 451 452 453 454
Error if arg is not nil and not a cons cell.  See also `car-safe'.")
  (list)
     register Lisp_Object list;
{
  while (1)
    {
455
      if (CONSP (list))
Jim Blandy's avatar
Jim Blandy committed
456 457 458 459 460 461 462 463 464 465 466 467 468
	return XCONS (list)->car;
      else if (EQ (list, Qnil))
	return Qnil;
      else
	list = wrong_type_argument (Qlistp, list);
    }
}

DEFUN ("car-safe", Fcar_safe, Scar_safe, 1, 1, 0,
  "Return the car of OBJECT if it is a cons cell, or else nil.")
  (object)
     Lisp_Object object;
{
469
  if (CONSP (object))
Jim Blandy's avatar
Jim Blandy committed
470 471 472 473 474 475
    return XCONS (object)->car;
  else
    return Qnil;
}

DEFUN ("cdr", Fcdr, Scdr, 1, 1, 0,
476
  "Return the cdr of LIST.  If arg is nil, return nil.\n\
Jim Blandy's avatar
Jim Blandy committed
477 478 479 480 481 482 483
Error if arg is not nil and not a cons cell.  See also `cdr-safe'.")

  (list)
     register Lisp_Object list;
{
  while (1)
    {
484
      if (CONSP (list))
Jim Blandy's avatar
Jim Blandy committed
485 486 487 488 489 490 491 492 493
	return XCONS (list)->cdr;
      else if (EQ (list, Qnil))
	return Qnil;
      else
	list = wrong_type_argument (Qlistp, list);
    }
}

DEFUN ("cdr-safe", Fcdr_safe, Scdr_safe, 1, 1, 0,
494
  "Return the cdr of OBJECT if it is a cons cell, or else nil.")
Jim Blandy's avatar
Jim Blandy committed
495 496 497
  (object)
     Lisp_Object object;
{
498
  if (CONSP (object))
Jim Blandy's avatar
Jim Blandy committed
499 500 501 502 503 504
    return XCONS (object)->cdr;
  else
    return Qnil;
}

DEFUN ("setcar", Fsetcar, Ssetcar, 2, 2, 0,
505
  "Set the car of CELL to be NEWCAR.  Returns NEWCAR.")
Jim Blandy's avatar
Jim Blandy committed
506 507 508
  (cell, newcar)
     register Lisp_Object cell, newcar;
{
509
  if (!CONSP (cell))
Jim Blandy's avatar
Jim Blandy committed
510 511 512 513 514 515 516 517
    cell = wrong_type_argument (Qconsp, cell);

  CHECK_IMPURE (cell);
  XCONS (cell)->car = newcar;
  return newcar;
}

DEFUN ("setcdr", Fsetcdr, Ssetcdr, 2, 2, 0,
518
  "Set the cdr of CELL to be NEWCDR.  Returns NEWCDR.")
Jim Blandy's avatar
Jim Blandy committed
519 520 521
  (cell, newcdr)
     register Lisp_Object cell, newcdr;
{
522
  if (!CONSP (cell))
Jim Blandy's avatar
Jim Blandy committed
523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540
    cell = wrong_type_argument (Qconsp, cell);

  CHECK_IMPURE (cell);
  XCONS (cell)->cdr = newcdr;
  return newcdr;
}

/* Extract and set components of symbols */

DEFUN ("boundp", Fboundp, Sboundp, 1, 1, 0, "T if SYMBOL's value is not void.")
  (sym)
     register Lisp_Object sym;
{
  Lisp_Object valcontents;
  CHECK_SYMBOL (sym, 0);

  valcontents = XSYMBOL (sym)->value;

Karl Heuer's avatar
Karl Heuer committed
541 542
  if (BUFFER_LOCAL_VALUEP (valcontents)
      || SOME_BUFFER_LOCAL_VALUEP (valcontents))
543
    valcontents = swap_in_symval_forwarding (sym, valcontents);
Jim Blandy's avatar
Jim Blandy committed
544

545
  return (EQ (valcontents, Qunbound) ? Qnil : Qt);
Jim Blandy's avatar
Jim Blandy committed
546 547 548 549 550 551 552
}

DEFUN ("fboundp", Ffboundp, Sfboundp, 1, 1, 0, "T if SYMBOL's function definition is not void.")
  (sym)
     register Lisp_Object sym;
{
  CHECK_SYMBOL (sym, 0);
553
  return (EQ (XSYMBOL (sym)->function, Qunbound) ? Qnil : Qt);
Jim Blandy's avatar
Jim Blandy committed
554 555 556 557 558 559 560
}

DEFUN ("makunbound", Fmakunbound, Smakunbound, 1, 1, 0, "Make SYMBOL's value be void.")
  (sym)
     register Lisp_Object sym;
{
  CHECK_SYMBOL (sym, 0);
Jim Blandy's avatar
Jim Blandy committed
561
  if (NILP (sym) || EQ (sym, Qt))
Jim Blandy's avatar
Jim Blandy committed
562 563 564 565 566 567 568 569 570 571
    return Fsignal (Qsetting_constant, Fcons (sym, Qnil));
  Fset (sym, Qunbound);
  return sym;
}

DEFUN ("fmakunbound", Ffmakunbound, Sfmakunbound, 1, 1, 0, "Make SYMBOL's function definition be void.")
  (sym)
     register Lisp_Object sym;
{
  CHECK_SYMBOL (sym, 0);
572 573
  if (NILP (sym) || EQ (sym, Qt))
    return Fsignal (Qsetting_constant, Fcons (sym, Qnil));
Jim Blandy's avatar
Jim Blandy committed
574 575 576 577 578 579
  XSYMBOL (sym)->function = Qunbound;
  return sym;
}

DEFUN ("symbol-function", Fsymbol_function, Ssymbol_function, 1, 1, 0,
  "Return SYMBOL's function definition.  Error if that is void.")
Jim Blandy's avatar
Jim Blandy committed
580 581
  (symbol)
     register Lisp_Object symbol;
Jim Blandy's avatar
Jim Blandy committed
582
{
Jim Blandy's avatar
Jim Blandy committed
583 584 585 586
  CHECK_SYMBOL (symbol, 0);
  if (EQ (XSYMBOL (symbol)->function, Qunbound))
    return Fsignal (Qvoid_function, Fcons (symbol, Qnil));
  return XSYMBOL (symbol)->function;
Jim Blandy's avatar
Jim Blandy committed
587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603
}

DEFUN ("symbol-plist", Fsymbol_plist, Ssymbol_plist, 1, 1, 0, "Return SYMBOL's property list.")
  (sym)
     register Lisp_Object sym;
{
  CHECK_SYMBOL (sym, 0);
  return XSYMBOL (sym)->plist;
}

DEFUN ("symbol-name", Fsymbol_name, Ssymbol_name, 1, 1, 0, "Return SYMBOL's name, a string.")
  (sym)
     register Lisp_Object sym;
{
  register Lisp_Object name;

  CHECK_SYMBOL (sym, 0);
604
  XSETSTRING (name, XSYMBOL (sym)->name);
Jim Blandy's avatar
Jim Blandy committed
605 606 607 608 609 610 611 612 613
  return name;
}

DEFUN ("fset", Ffset, Sfset, 2, 2, 0,
  "Set SYMBOL's function definition to NEWVAL, and return NEWVAL.")
  (sym, newdef)
     register Lisp_Object sym, newdef;
{
  CHECK_SYMBOL (sym, 0);
614 615
  if (NILP (sym) || EQ (sym, Qt))
    return Fsignal (Qsetting_constant, Fcons (sym, Qnil));
Jim Blandy's avatar
Jim Blandy committed
616
  if (!NILP (Vautoload_queue) && !EQ (XSYMBOL (sym)->function, Qunbound))
Jim Blandy's avatar
Jim Blandy committed
617 618 619
    Vautoload_queue = Fcons (Fcons (sym, XSYMBOL (sym)->function),
			     Vautoload_queue);
  XSYMBOL (sym)->function = newdef;
620
  /* Handle automatic advice activation */
621
  if (CONSP (XSYMBOL (sym)->plist) && !NILP (Fget (sym, Qad_advice_info)))
622
    {
623
      call2 (Qad_activate, sym, Qnil);
624 625
      newdef = XSYMBOL (sym)->function;
    }
Jim Blandy's avatar
Jim Blandy committed
626 627 628
  return newdef;
}

629 630
/* This name should be removed once it is eliminated from elsewhere.  */

631
DEFUN ("defalias", Fdefalias, Sdefalias, 2, 2, 0,
632 633 634 635 636 637 638 639 640 641
  "Set SYMBOL's function definition to NEWVAL, and return NEWVAL.\n\
Associates the function with the current load file, if any.")
  (sym, newdef)
     register Lisp_Object sym, newdef;
{
  CHECK_SYMBOL (sym, 0);
  if (!NILP (Vautoload_queue) && !EQ (XSYMBOL (sym)->function, Qunbound))
    Vautoload_queue = Fcons (Fcons (sym, XSYMBOL (sym)->function),
			     Vautoload_queue);
  XSYMBOL (sym)->function = newdef;
642 643 644 645 646 647
  /* Handle automatic advice activation */
  if (CONSP (XSYMBOL (sym)->plist) && !NILP (Fget (sym, Qad_advice_info)))
    {
      call2 (Qad_activate, sym, Qnil);
      newdef = XSYMBOL (sym)->function;
    }
648 649 650 651
  LOADHIST_ATTACH (sym);
  return newdef;
}

652 653 654 655 656 657 658 659 660 661 662
DEFUN ("define-function", Fdefine_function, Sdefine_function, 2, 2, 0,
  "Set SYMBOL's function definition to NEWVAL, and return NEWVAL.\n\
Associates the function with the current load file, if any.")
  (sym, newdef)
     register Lisp_Object sym, newdef;
{
  CHECK_SYMBOL (sym, 0);
  if (!NILP (Vautoload_queue) && !EQ (XSYMBOL (sym)->function, Qunbound))
    Vautoload_queue = Fcons (Fcons (sym, XSYMBOL (sym)->function),
			     Vautoload_queue);
  XSYMBOL (sym)->function = newdef;
663 664 665 666 667 668
  /* Handle automatic advice activation */
  if (CONSP (XSYMBOL (sym)->plist) && !NILP (Fget (sym, Qad_advice_info)))
    {
      call2 (Qad_activate, sym, Qnil);
      newdef = XSYMBOL (sym)->function;
    }
669 670 671 672
  LOADHIST_ATTACH (sym);
  return newdef;
}

Jim Blandy's avatar
Jim Blandy committed
673 674 675 676 677 678 679 680 681
DEFUN ("setplist", Fsetplist, Ssetplist, 2, 2, 0,
  "Set SYMBOL's property list to NEWVAL, and return NEWVAL.")
  (sym, newplist)
     register Lisp_Object sym, newplist;
{
  CHECK_SYMBOL (sym, 0);
  XSYMBOL (sym)->plist = newplist;
  return newplist;
}
Jim Blandy's avatar
Jim Blandy committed
682

Jim Blandy's avatar
Jim Blandy committed
683 684 685 686 687 688 689 690 691 692 693 694 695

/* Getting and setting values of symbols */

/* Given the raw contents of a symbol value cell,
   return the Lisp value of the symbol.
   This does not handle buffer-local variables; use
   swap_in_symval_forwarding for that.  */

Lisp_Object
do_symval_forwarding (valcontents)
     register Lisp_Object valcontents;
{
  register Lisp_Object val;
696 697
  int offset;
  if (MISCP (valcontents))
698
    switch (XMISCTYPE (valcontents))
699 700 701 702
      {
      case Lisp_Misc_Intfwd:
	XSETINT (val, *XINTFWD (valcontents)->intvar);
	return val;
Jim Blandy's avatar
Jim Blandy committed
703

704 705
      case Lisp_Misc_Boolfwd:
	return (*XBOOLFWD (valcontents)->boolvar ? Qt : Qnil);
Jim Blandy's avatar
Jim Blandy committed
706

707 708
      case Lisp_Misc_Objfwd:
	return *XOBJFWD (valcontents)->objvar;
Jim Blandy's avatar
Jim Blandy committed
709

710 711 712
      case Lisp_Misc_Buffer_Objfwd:
	offset = XBUFFER_OBJFWD (valcontents)->offset;
	return *(Lisp_Object *)(offset + (char *)current_buffer);
713

714 715 716
      case Lisp_Misc_Kboard_Objfwd:
	offset = XKBOARD_OBJFWD (valcontents)->offset;
	return *(Lisp_Object *)(offset + (char *)current_kboard);
717
      }
Jim Blandy's avatar
Jim Blandy committed
718 719 720 721 722 723 724 725 726 727 728 729 730
  return valcontents;
}

/* Store NEWVAL into SYM, where VALCONTENTS is found in the value cell
   of SYM.  If SYM is buffer-local, VALCONTENTS should be the
   buffer-independent contents of the value cell: forwarded just one
   step past the buffer-localness.  */

void
store_symval_forwarding (sym, valcontents, newval)
     Lisp_Object sym;
     register Lisp_Object valcontents, newval;
{
731
  switch (SWITCH_ENUM_CAST (XTYPE (valcontents)))
Jim Blandy's avatar
Jim Blandy committed
732
    {
733
    case Lisp_Misc:
734
      switch (XMISCTYPE (valcontents))
735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760
	{
	case Lisp_Misc_Intfwd:
	  CHECK_NUMBER (newval, 1);
	  *XINTFWD (valcontents)->intvar = XINT (newval);
	  break;

	case Lisp_Misc_Boolfwd:
	  *XBOOLFWD (valcontents)->boolvar = NILP (newval) ? 0 : 1;
	  break;

	case Lisp_Misc_Objfwd:
	  *XOBJFWD (valcontents)->objvar = newval;
	  break;

	case Lisp_Misc_Buffer_Objfwd:
	  {
	    int offset = XBUFFER_OBJFWD (valcontents)->offset;
	    Lisp_Object type;

	    type = *(Lisp_Object *)(offset + (char *)&buffer_local_types);
	    if (! NILP (type) && ! NILP (newval)
		&& XTYPE (newval) != XINT (type))
	      buffer_slot_type_mismatch (offset);

	    *(Lisp_Object *)(offset + (char *)current_buffer) = newval;
	  }
761 762
	  break;

763 764 765
	case Lisp_Misc_Kboard_Objfwd:
	  (*(Lisp_Object *)((char *)current_kboard
			    + XKBOARD_OBJFWD (valcontents)->offset))
766 767 768
	    = newval;
	  break;

769 770 771
	default:
	  goto def;
	}
Jim Blandy's avatar
Jim Blandy committed
772 773 774
      break;

    default:
775
    def:
Jim Blandy's avatar
Jim Blandy committed
776
      valcontents = XSYMBOL (sym)->value;
777 778
      if (BUFFER_LOCAL_VALUEP (valcontents)
	  || SOME_BUFFER_LOCAL_VALUEP (valcontents))
779
	XBUFFER_LOCAL_VALUE (valcontents)->car = newval;
Jim Blandy's avatar
Jim Blandy committed
780 781 782 783 784 785 786 787 788 789 790 791 792
      else
	XSYMBOL (sym)->value = newval;
    }
}

/* Set up the buffer-local symbol SYM for validity in the current
   buffer.  VALCONTENTS is the contents of its value cell.
   Return the value forwarded one step past the buffer-local indicator.  */

static Lisp_Object
swap_in_symval_forwarding (sym, valcontents)
     Lisp_Object sym, valcontents;
{
793
  /* valcontents is a pointer to a struct resembling the cons
Jim Blandy's avatar
Jim Blandy committed
794
     (REALVALUE BUFFER CURRENT-ALIST-ELEMENT . DEFAULT-VALUE)).
795

Jim Blandy's avatar
Jim Blandy committed
796
     CURRENT-ALIST-ELEMENT is a pointer to an element of BUFFER's
797 798 799 800 801 802 803 804 805 806 807
     local_var_alist, that being the element whose car is this
     variable.  Or it can be a pointer to the
     (CURRENT-ALIST-ELEMENT . DEFAULT-VALUE), if BUFFER does not have
     an element in its alist for this variable.

     If the current buffer is not BUFFER, we store the current
     REALVALUE value into CURRENT-ALIST-ELEMENT, then find the
     appropriate alist element for the buffer now current and set up
     CURRENT-ALIST-ELEMENT.  Then we set REALVALUE out of that
     element, and store into BUFFER.

Jim Blandy's avatar
Jim Blandy committed
808 809 810
     Note that REALVALUE can be a forwarding pointer. */

  register Lisp_Object tem1;
811
  tem1 = XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->car;
Jim Blandy's avatar
Jim Blandy committed
812

Jim Blandy's avatar
Jim Blandy committed
813
  if (NILP (tem1) || current_buffer != XBUFFER (tem1))
Jim Blandy's avatar
Jim Blandy committed
814
    {
815 816 817
      tem1 = XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car;
      Fsetcdr (tem1,
	       do_symval_forwarding (XBUFFER_LOCAL_VALUE (valcontents)->car));
Jim Blandy's avatar
Jim Blandy committed
818
      tem1 = assq_no_quit (sym, current_buffer->local_var_alist);
Jim Blandy's avatar
Jim Blandy committed
819
      if (NILP (tem1))
820 821 822 823 824 825
	tem1 = XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr;
      XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car = tem1;
      XSETBUFFER (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->car,
		  current_buffer);
      store_symval_forwarding (sym, XBUFFER_LOCAL_VALUE (valcontents)->car,
			       Fcdr (tem1));
Jim Blandy's avatar
Jim Blandy committed
826
    }
827
  return XBUFFER_LOCAL_VALUE (valcontents)->car;
Jim Blandy's avatar
Jim Blandy committed
828 829
}

Jim Blandy's avatar
Jim Blandy committed
830 831 832 833 834
/* Find the value of a symbol, returning Qunbound if it's not bound.
   This is helpful for code which just wants to get a variable's value
   if it has one, without signalling an error.
   Note that it must not be possible to quit
   within this function.  Great care is required for this.  */
Jim Blandy's avatar
Jim Blandy committed
835

Jim Blandy's avatar
Jim Blandy committed
836 837
Lisp_Object
find_symbol_value (sym)
Jim Blandy's avatar
Jim Blandy committed
838 839 840 841 842 843 844
     Lisp_Object sym;
{
  register Lisp_Object valcontents, tem1;
  register Lisp_Object val;
  CHECK_SYMBOL (sym, 0);
  valcontents = XSYMBOL (sym)->value;

Karl Heuer's avatar
Karl Heuer committed
845 846
  if (BUFFER_LOCAL_VALUEP (valcontents)
      || SOME_BUFFER_LOCAL_VALUEP (valcontents))
847
    valcontents = swap_in_symval_forwarding (sym, valcontents);
Jim Blandy's avatar
Jim Blandy committed
848

849 850
  if (MISCP (valcontents))
    {
851
      switch (XMISCTYPE (valcontents))
852 853 854 855
	{
	case Lisp_Misc_Intfwd:
	  XSETINT (val, *XINTFWD (valcontents)->intvar);
	  return val;
Jim Blandy's avatar
Jim Blandy committed
856

857 858
	case Lisp_Misc_Boolfwd:
	  return (*XBOOLFWD (valcontents)->boolvar ? Qt : Qnil);
Jim Blandy's avatar
Jim Blandy committed
859

860 861
	case Lisp_Misc_Objfwd:
	  return *XOBJFWD (valcontents)->objvar;
Jim Blandy's avatar
Jim Blandy committed
862

863 864 865
	case Lisp_Misc_Buffer_Objfwd:
	  return *(Lisp_Object *)(XBUFFER_OBJFWD (valcontents)->offset
				  + (char *)current_buffer);
866

867 868 869
	case Lisp_Misc_Kboard_Objfwd:
	  return *(Lisp_Object *)(XKBOARD_OBJFWD (valcontents)->offset
				  + (char *)current_kboard);
870
	}
Jim Blandy's avatar
Jim Blandy committed
871 872 873 874 875
    }

  return valcontents;
}

Jim Blandy's avatar
Jim Blandy committed
876 877 878 879 880
DEFUN ("symbol-value", Fsymbol_value, Ssymbol_value, 1, 1, 0,
  "Return SYMBOL's value.  Error if that is void.")
  (sym)
     Lisp_Object sym;
{
881
  Lisp_Object val;
Jim Blandy's avatar
Jim Blandy committed
882

883
  val = find_symbol_value (sym);
Jim Blandy's avatar
Jim Blandy committed
884 885 886 887 888 889
  if (EQ (val, Qunbound))
    return Fsignal (Qvoid_variable, Fcons (sym, Qnil));
  else
    return val;
}

Jim Blandy's avatar
Jim Blandy committed
890 891 892 893 894
DEFUN ("set", Fset, Sset, 2, 2, 0,
  "Set SYMBOL's value to NEWVAL, and return NEWVAL.")
  (sym, newval)
     register Lisp_Object sym, newval;
{
895
  int voide = EQ (newval, Qunbound);
Jim Blandy's avatar
Jim Blandy committed
896 897 898 899

  register Lisp_Object valcontents, tem1, current_alist_element;

  CHECK_SYMBOL (sym, 0);
Jim Blandy's avatar
Jim Blandy committed
900
  if (NILP (sym) || EQ (sym, Qt))
Jim Blandy's avatar
Jim Blandy committed
901 902 903
    return Fsignal (Qsetting_constant, Fcons (sym, Qnil));
  valcontents = XSYMBOL (sym)->value;

904
  if (BUFFER_OBJFWDP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
905
    {
906
      register int idx = XBUFFER_OBJFWD (valcontents)->offset;
907 908
      register int mask = XINT (*((Lisp_Object *)
				  (idx + (char *)&buffer_local_flags)));
Jim Blandy's avatar
Jim Blandy committed
909 910 911 912
      if (mask > 0)
	current_buffer->local_var_flags |= mask;
    }

913 914
  else if (BUFFER_LOCAL_VALUEP (valcontents)
	   || SOME_BUFFER_LOCAL_VALUEP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
915
    {
916 917
      /* valcontents is actually a pointer to a struct resembling a cons,
	 with contents something like:
Jim Blandy's avatar
Jim Blandy committed
918 919 920 921 922 923 924 925 926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945
	 (REALVALUE BUFFER CURRENT-ALIST-ELEMENT . DEFAULT-VALUE).

	 BUFFER is the last buffer for which this symbol's value was
	 made up to date.

	 CURRENT-ALIST-ELEMENT is a pointer to an element of BUFFER's
	 local_var_alist, that being the element whose car is this
	 variable.  Or it can be a pointer to the
	 (CURRENT-ALIST-ELEMENT . DEFAULT-VALUE), if BUFFER does not
	 have an element in its alist for this variable (that is, if
	 BUFFER sees the default value of this variable).

	 If we want to examine or set the value and BUFFER is current,
	 we just examine or set REALVALUE. If BUFFER is not current, we
	 store the current REALVALUE value into CURRENT-ALIST-ELEMENT,
	 then find the appropriate alist element for the buffer now
	 current and set up CURRENT-ALIST-ELEMENT.  Then we set
	 REALVALUE out of that element, and store into BUFFER.

	 If we are setting the variable and the current buffer does
	 not have an alist entry for this variable, an alist entry is
	 created.

	 Note that REALVALUE can be a forwarding pointer.  Each time
	 it is examined or set, forwarding must be done.  */

      /* What value are we caching right now?  */
      current_alist_element =
946
	XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car;
Jim Blandy's avatar
Jim Blandy committed
947 948 949 950 951 952

      /* If the current buffer is not the buffer whose binding is
	 currently cached, or if it's a Lisp_Buffer_Local_Value and
	 we're looking at the default value, the cache is invalid; we
	 need to write it out, and find the new CURRENT-ALIST-ELEMENT.  */
      if ((current_buffer
953
	   != XBUFFER (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->car))
954
	  || (BUFFER_LOCAL_VALUEP (valcontents)
955 956
	      && EQ (XCONS (current_alist_element)->car,
		     current_alist_element)))
Jim Blandy's avatar
Jim Blandy committed
957
	{
Jim Blandy's avatar
Jim Blandy committed
958 959 960 961
	  /* Write out the cached value for the old buffer; copy it
	     back to its alist element.  This works if the current
	     buffer only sees the default value, too.  */
          Fsetcdr (current_alist_element,
962
		   do_symval_forwarding (XBUFFER_LOCAL_VALUE (valcontents)->car));
Jim Blandy's avatar
Jim Blandy committed
963

Jim Blandy's avatar
Jim Blandy committed
964
	  /* Find the new value for CURRENT-ALIST-ELEMENT.  */
Jim Blandy's avatar
Jim Blandy committed
965
	  tem1 = Fassq (sym, current_buffer->local_var_alist);
Jim Blandy's avatar
Jim Blandy committed
966
	  if (NILP (tem1))
Jim Blandy's avatar
Jim Blandy committed
967 968 969 970 971 972
	    {
	      /* This buffer still sees the default value.  */

	      /* If the variable is a Lisp_Some_Buffer_Local_Value,
		 make CURRENT-ALIST-ELEMENT point to itself,
		 indicating that we're seeing the default value.  */
973
	      if (SOME_BUFFER_LOCAL_VALUEP (valcontents))
974
		tem1 = XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr;
Jim Blandy's avatar
Jim Blandy committed
975 976 977 978 979 980 981 982 983 984 985 986

	      /* If it's a Lisp_Buffer_Local_Value, give this buffer a
		 new assoc for a local value and set
		 CURRENT-ALIST-ELEMENT to point to that.  */
	      else
		{
		  tem1 = Fcons (sym, Fcdr (current_alist_element));
		  current_buffer->local_var_alist =
		    Fcons (tem1, current_buffer->local_var_alist);
		}
	    }
	  /* Cache the new buffer's assoc in CURRENT-ALIST-ELEMENT.  */
987 988
	  XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car
	    = tem1;
Jim Blandy's avatar
Jim Blandy committed
989 990

	  /* Set BUFFER, now that CURRENT-ALIST-ELEMENT is accurate.  */
991 992
	  XSETBUFFER (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->car,
		      current_buffer);
Jim Blandy's avatar
Jim Blandy committed
993
	}
994
      valcontents = XBUFFER_LOCAL_VALUE (valcontents)->car;
Jim Blandy's avatar
Jim Blandy committed
995
    }
Jim Blandy's avatar
Jim Blandy committed
996

Jim Blandy's avatar
Jim Blandy committed
997 998 999 1000 1001 1002
  /* If storing void (making the symbol void), forward only through
     buffer-local indicator, not through Lisp_Objfwd, etc.  */
  if (voide)
    store_symval_forwarding (sym, Qnil, newval);
  else
    store_symval_forwarding (sym, valcontents, newval);
Jim Blandy's avatar
Jim Blandy committed
1003

Jim Blandy's avatar
Jim Blandy committed
1004 1005 1006 1007 1008 1009
  return newval;
}

/* Access or set a buffer-local symbol's default value.  */

/* Return the default value of SYM, but don't check for voidness.
1010
   Return Qunbound if it is void.  */
Jim Blandy's avatar
Jim Blandy committed
1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022

Lisp_Object
default_value (sym)
     Lisp_Object sym;
{
  register Lisp_Object valcontents;

  CHECK_SYMBOL (sym, 0);
  valcontents = XSYMBOL (sym)->value;

  /* For a built-in buffer-local variable, get the default value
     rather than letting do_symval_forwarding get the current value.  */
1023
  if (BUFFER_OBJFWDP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
1024
    {
1025
      register int idx = XBUFFER_OBJFWD (valcontents)->offset;
Jim Blandy's avatar
Jim Blandy committed
1026

1027
      if (XINT (*(Lisp_Object *) (idx + (char *) &buffer_local_flags)) != 0)
Jim Blandy's avatar
Jim Blandy committed
1028 1029 1030 1031
	return *(Lisp_Object *)(idx + (char *) &buffer_defaults);
    }

  /* Handle user-created local variables.  */
1032 1033
  if (BUFFER_LOCAL_VALUEP (valcontents)
      || SOME_BUFFER_LOCAL_VALUEP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
1034 1035 1036 1037 1038 1039 1040
    {
      /* If var is set up for a buffer that lacks a local value for it,
	 the current value is nominally the default value.
	 But the current value slot may be more up to date, since
	 ordinary setq stores just that slot.  So use that.  */
      Lisp_Object current_alist_element, alist_element_car;
      current_alist_element
1041
	= XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car;
Jim Blandy's avatar
Jim Blandy committed
1042 1043
      alist_element_car = XCONS (current_alist_element)->car;
      if (EQ (alist_element_car, current_alist_element))
1044
	return do_symval_forwarding (XBUFFER_LOCAL_VALUE (valcontents)->car);
Jim Blandy's avatar
Jim Blandy committed
1045
      else
1046
	return XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->cdr;
Jim Blandy's avatar
Jim Blandy committed
1047 1048 1049 1050 1051 1052 1053 1054 1055 1056 1057 1058 1059 1060 1061
    }
  /* For other variables, get the current value.  */
  return do_symval_forwarding (valcontents);
}

DEFUN ("default-boundp", Fdefault_boundp, Sdefault_boundp, 1, 1, 0,
  "Return T if SYMBOL has a non-void default value.\n\
This is the value that is seen in buffers that do not have their own values\n\
for this variable.")
  (sym)
     Lisp_Object sym;
{
  register Lisp_Object value;

  value = default_value (sym);
1062
  return (EQ (value, Qunbound) ? Qnil : Qt);
Jim Blandy's avatar
Jim Blandy committed
1063 1064 1065 1066 1067 1068 1069 1070 1071 1072 1073 1074 1075
}

DEFUN ("default-value", Fdefault_value, Sdefault_value, 1, 1, 0,
  "Return SYMBOL's default value.\n\
This is the value that is seen in buffers that do not have their own values\n\
for this variable.  The default value is meaningful for variables with\n\
local bindings in certain buffers.")
  (sym)
     Lisp_Object sym;
{
  register Lisp_Object value;

  value = default_value (sym);
1076
  if (EQ (value, Qunbound))
Jim Blandy's avatar
Jim Blandy committed
1077 1078 1079 1080 1081 1082 1083 1084 1085 1086 1087 1088 1089 1090 1091 1092 1093 1094 1095
    return Fsignal (Qvoid_variable, Fcons (sym, Qnil));
  return value;
}

DEFUN ("set-default", Fset_default, Sset_default, 2, 2, 0,
  "Set SYMBOL's default value to VAL.  SYMBOL and VAL are evaluated.\n\
The default value is seen in buffers that do not have their own values\n\
for this variable.")
  (sym, value)
     Lisp_Object sym, value;
{
  register Lisp_Object valcontents, current_alist_element, alist_element_buffer;

  CHECK_SYMBOL (sym, 0);
  valcontents = XSYMBOL (sym)->value;

  /* Handle variables like case-fold-search that have special slots
     in the buffer.  Make them work apparently like Lisp_Buffer_Local_Value
     variables.  */
1096
  if (BUFFER_OBJFWDP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
1097
    {
1098
      register int idx = XBUFFER_OBJFWD (valcontents)->offset;
Jim Blandy's avatar
Jim Blandy committed
1099
      register struct buffer *b;
1100 1101
      register int mask = XINT (*((Lisp_Object *)
				  (idx + (char *)&buffer_local_flags)));
Jim Blandy's avatar
Jim Blandy committed
1102 1103 1104 1105 1106 1107 1108 1109 1110 1111 1112

      if (mask > 0)
	{
	  *(Lisp_Object *)(idx + (char *) &buffer_defaults) = value;
	  for (b = all_buffers; b; b = b->next)
	    if (!(b->local_var_flags & mask))
	      *(Lisp_Object *)(idx + (char *) b) = value;
	}
      return value;
    }

1113 1114
  if (!BUFFER_LOCAL_VALUEP (valcontents)
      && !SOME_BUFFER_LOCAL_VALUEP (valcontents))
Jim Blandy's avatar
Jim Blandy committed
1115 1116 1117
    return Fset (sym, value);

  /* Store new value into the DEFAULT-VALUE slot */
1118
  XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->cdr = value;
Jim Blandy's avatar
Jim Blandy committed
1119 1120

  /* If that slot is current, we must set the REALVALUE slot too */
1121 1122
  current_alist_element
    = XCONS (XCONS (XBUFFER_LOCAL_VALUE (valcontents)->cdr)->cdr)->car;
Jim Blandy's avatar
Jim Blandy committed
1123 1124
  alist_element_buffer = Fcar (current_alist_element);
  if (EQ (alist_element_buffer, current_alist_element))
1125 1126
    store_symval_forwarding (sym, XBUFFER_LOCAL_VALUE (valcontents)->car,
			     value);
Jim Blandy's avatar
Jim Blandy committed
1127 1128 1129 1130 1131

  return value;
}

DEFUN ("setq-default", Fsetq_default, Ssetq_default, 2, UNEVALLED, 0,