eval.c 98.4 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Evaluator for GNU Emacs Lisp interpreter.
2 3
   Copyright (C) 1985, 1986, 1987, 1993, 1994, 1995, 1999, 2000, 2001,
     2002, 2004, 2005 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
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 22


23
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
24
#include "lisp.h"
25
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
26
#include "commands.h"
Jim Blandy's avatar
Jim Blandy committed
27
#include "keyboard.h"
28
#include "dispextern.h"
Jim Blandy's avatar
Jim Blandy committed
29 30 31 32 33 34
#include <setjmp.h>

/* This definition is duplicated in alloc.c and keyboard.c */
/* Putting it in lisp.h makes cc bomb out! */

struct backtrace
35 36 37 38 39
{
  struct backtrace *next;
  Lisp_Object *function;
  Lisp_Object *args;	/* Points to vector of args. */
  int nargs;		/* Length of vector.
Jim Blandy's avatar
Jim Blandy committed
40 41
			   If nargs is UNEVALLED, args points to slot holding
			   list of unevalled args */
42 43 44 45
  char evalargs;
  /* Nonzero means call value of debugger when done with this operation. */
  char debug_on_exit;
};
Jim Blandy's avatar
Jim Blandy committed
46 47 48

struct backtrace *backtrace_list;

49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66
/* This structure helps implement the `catch' and `throw' control
   structure.  A struct catchtag contains all the information needed
   to restore the state of the interpreter after a non-local jump.

   Handlers for error conditions (represented by `struct handler'
   structures) just point to a catch tag to do the cleanup required
   for their jumps.

   catchtag structures are chained together in the C calling stack;
   the `next' member points to the next outer catchtag.

   A call like (throw TAG VAL) searches for a catchtag whose `tag'
   member is TAG, and then unbinds to it.  The `val' member is used to
   hold VAL while the stack is unwound; `val' is returned as the value
   of the catch form.

   All the other members are concerned with restoring the interpreter
   state.  */
67

Jim Blandy's avatar
Jim Blandy committed
68
struct catchtag
69 70 71 72 73 74 75 76 77 78 79
{
  Lisp_Object tag;
  Lisp_Object val;
  struct catchtag *next;
  struct gcpro *gcpro;
  jmp_buf jmp;
  struct backtrace *backlist;
  struct handler *handlerlist;
  int lisp_eval_depth;
  int pdlcount;
  int poll_suppress_count;
80
  int interrupt_input_blocked;
81 82
  struct byte_stack *byte_stack;
};
Jim Blandy's avatar
Jim Blandy committed
83 84 85

struct catchtag *catchlist;

86 87 88 89 90
#ifdef DEBUG_GCPRO
/* Count levels of GCPRO to detect failure to UNGCPRO.  */
int gcpro_level;
#endif

91
Lisp_Object Qautoload, Qmacro, Qexit, Qinteractive, Qcommandp, Qdefun;
Jim Blandy's avatar
Jim Blandy committed
92
Lisp_Object Qinhibit_quit, Vinhibit_quit, Vquit_flag;
Jim Blandy's avatar
Jim Blandy committed
93 94
Lisp_Object Qand_rest, Qand_optional;
Lisp_Object Qdebug_on_error;
95
Lisp_Object Qdeclare;
Jim Blandy's avatar
Jim Blandy committed
96

97 98 99
/* This holds either the symbol `run-hooks' or nil.
   It is nil at an early stage of startup, and when Emacs
   is shutting down.  */
100

Jim Blandy's avatar
Jim Blandy committed
101 102 103 104 105 106 107 108 109 110
Lisp_Object Vrun_hooks;

/* Non-nil means record all fset's and provide's, to be undone
   if the file being autoloaded is not fully loaded.
   They are recorded by being consed onto the front of Vautoload_queue:
   (FUN . ODEF) for a defun, (OFEATURES . nil) for a provide.  */

Lisp_Object Vautoload_queue;

/* Current number of specbindings allocated in specpdl.  */
111

Jim Blandy's avatar
Jim Blandy committed
112 113 114
int specpdl_size;

/* Pointer to beginning of specpdl.  */
115

Jim Blandy's avatar
Jim Blandy committed
116 117 118
struct specbinding *specpdl;

/* Pointer to first unused element in specpdl.  */
119

120
volatile struct specbinding *specpdl_ptr;
Jim Blandy's avatar
Jim Blandy committed
121 122

/* Maximum size allowed for specpdl allocation */
123

124
EMACS_INT max_specpdl_size;
Jim Blandy's avatar
Jim Blandy committed
125 126

/* Depth in Lisp evaluations and function calls.  */
127

Jim Blandy's avatar
Jim Blandy committed
128 129 130
int lisp_eval_depth;

/* Maximum allowed depth in Lisp evaluations and function calls.  */
131

132
EMACS_INT max_lisp_eval_depth;
Jim Blandy's avatar
Jim Blandy committed
133 134

/* Nonzero means enter debugger before next function call */
135

Jim Blandy's avatar
Jim Blandy committed
136 137
int debug_on_next_call;

138
/* Non-zero means debugger may continue.  This is zero when the
139 140 141 142 143
   debugger is called during redisplay, where it might not be safe to
   continue the interrupted redisplay. */

int debugger_may_continue;

Roland McGrath's avatar
Roland McGrath committed
144
/* List of conditions (non-nil atom means all) which cause a backtrace
145
   if an error is handled by the command loop's error handler.  */
146

Roland McGrath's avatar
Roland McGrath committed
147
Lisp_Object Vstack_trace_on_error;
Jim Blandy's avatar
Jim Blandy committed
148

Roland McGrath's avatar
Roland McGrath committed
149
/* List of conditions (non-nil atom means all) which enter the debugger
150
   if an error is handled by the command loop's error handler.  */
151

Roland McGrath's avatar
Roland McGrath committed
152
Lisp_Object Vdebug_on_error;
Jim Blandy's avatar
Jim Blandy committed
153

Karl Heuer's avatar
Karl Heuer committed
154
/* List of conditions and regexps specifying error messages which
155
   do not enter the debugger even if Vdebug_on_error says they should.  */
156

Karl Heuer's avatar
Karl Heuer committed
157 158
Lisp_Object Vdebug_ignored_errors;

159
/* Non-nil means call the debugger even if the error will be handled.  */
160

161
Lisp_Object Vdebug_on_signal;
162 163

/* Hook for edebug to use.  */
164

165 166
Lisp_Object Vsignal_hook_function;

Jim Blandy's avatar
Jim Blandy committed
167
/* Nonzero means enter debugger if a quit signal
Roland McGrath's avatar
Roland McGrath committed
168
   is handled by the command loop's error handler. */
169

Jim Blandy's avatar
Jim Blandy committed
170 171
int debug_on_quit;

172
/* The value of num_nonmacro_input_events as of the last time we
173
   started to enter the debugger.  If we decide to enter the debugger
174
   again when this is still equal to num_nonmacro_input_events, then we
175 176 177
   know that the debugger itself has an error, and we should just
   signal the error instead of entering an infinite loop of debugger
   invocations.  */
178

179
int when_entered_debugger;
Jim Blandy's avatar
Jim Blandy committed
180 181 182

Lisp_Object Vdebugger;

183 184 185 186 187
/* The function from which the last `signal' was called.  Set in
   Fsignal.  */

Lisp_Object Vsignaling_function;

188 189 190 191 192 193
/* Set to non-zero while processing X events.  Checked in Feval to
   make sure the Lisp interpreter isn't called from a signal handler,
   which is unsafe because the interpreter isn't reentrant.  */

int handling_signal;

194 195 196 197 198
/* Function to process declarations in defmacro forms.  */

Lisp_Object Vmacro_declaration_function;


199
static Lisp_Object funcall_lambda P_ ((Lisp_Object, int, Lisp_Object*));
Jim Blandy's avatar
Jim Blandy committed
200

Andreas Schwab's avatar
Andreas Schwab committed
201
void
Jim Blandy's avatar
Jim Blandy committed
202 203 204
init_eval_once ()
{
  specpdl_size = 50;
205
  specpdl = (struct specbinding *) xmalloc (specpdl_size * sizeof (struct specbinding));
206
  specpdl_ptr = specpdl;
207
  max_specpdl_size = 1000;
208
  max_lisp_eval_depth = 300;
209 210

  Vrun_hooks = Qnil;
Jim Blandy's avatar
Jim Blandy committed
211 212
}

Andreas Schwab's avatar
Andreas Schwab committed
213
void
Jim Blandy's avatar
Jim Blandy committed
214 215 216 217 218 219 220 221 222
init_eval ()
{
  specpdl_ptr = specpdl;
  catchlist = 0;
  handlerlist = 0;
  backtrace_list = 0;
  Vquit_flag = Qnil;
  debug_on_next_call = 0;
  lisp_eval_depth = 0;
223
#ifdef DEBUG_GCPRO
224
  gcpro_level = 0;
225
#endif
226
  /* This is less than the initial value of num_nonmacro_input_events.  */
227
  when_entered_debugger = -1;
Jim Blandy's avatar
Jim Blandy committed
228 229
}

230 231 232 233 234 235 236 237 238 239 240 241
/* unwind-protect function used by call_debugger.  */

static Lisp_Object
restore_stack_limits (data)
     Lisp_Object data;
{
  max_specpdl_size = XINT (XCAR (data));
  max_lisp_eval_depth = XINT (XCDR (data));
}

/* Call the Lisp debugger, giving it argument ARG.  */

Jim Blandy's avatar
Jim Blandy committed
242 243 244 245
Lisp_Object
call_debugger (arg)
     Lisp_Object arg;
{
246
  int debug_while_redisplaying;
Juanma Barranquero's avatar
Juanma Barranquero committed
247
  int count = SPECPDL_INDEX ();
248
  Lisp_Object val;
249
  int old_max = max_specpdl_size;
250

251 252
  /* Temporarily bump up the stack limits,
     so the debugger won't run out of stack.  */
253

254 255 256 257 258 259 260 261 262 263 264
  max_specpdl_size += 1;
  record_unwind_protect (restore_stack_limits,
			 Fcons (make_number (old_max),
				make_number (max_lisp_eval_depth)));
  max_specpdl_size = old_max;

  if (lisp_eval_depth + 40 > max_lisp_eval_depth)
    max_lisp_eval_depth = lisp_eval_depth + 40;

  if (SPECPDL_INDEX () + 100 > max_specpdl_size)
    max_specpdl_size = SPECPDL_INDEX () + 100;
265

266
#ifdef HAVE_X_WINDOWS
267 268
  if (display_hourglass_p)
    cancel_hourglass ();
269 270
#endif

Jim Blandy's avatar
Jim Blandy committed
271
  debug_on_next_call = 0;
272
  when_entered_debugger = num_nonmacro_input_events;
273 274 275 276 277

  /* Resetting redisplaying_p to 0 makes sure that debug output is
     displayed if the debugger is invoked during redisplay.  */
  debug_while_redisplaying = redisplaying_p;
  redisplaying_p = 0;
278 279
  specbind (intern ("debugger-may-continue"),
	    debug_while_redisplaying ? Qnil : Qt);
280
  specbind (Qinhibit_redisplay, Qnil);
281
  specbind (Qdebug_on_error, Qnil);
282 283 284

#if 0 /* Binding this prevents execution of Lisp code during
	 redisplay, which necessarily leads to display problems.  */
285
  specbind (Qinhibit_eval_during_redisplay, Qt);
286
#endif
287

288 289 290 291
  val = apply1 (Vdebugger, arg);

  /* Interrupting redisplay and resuming it later is not safe under
     all circumstances.  So, when the debugger returns, abort the
292
     interrupted redisplay by going back to the top-level.  */
293 294 295
  if (debug_while_redisplaying)
    Ftop_level ();

296
  return unbind_to (count, val);
Jim Blandy's avatar
Jim Blandy committed
297 298
}

Andreas Schwab's avatar
Andreas Schwab committed
299
void
Jim Blandy's avatar
Jim Blandy committed
300 301 302 303 304 305 306 307 308 309 310 311 312
do_debug_on_call (code)
     Lisp_Object code;
{
  debug_on_next_call = 0;
  backtrace_list->debug_on_exit = 1;
  call_debugger (Fcons (code, Qnil));
}

/* NOTE!!! Every function that can call EVAL must protect its args
   and temporaries from garbage collection while it needs them.
   The definition of `For' shows what you have to do.  */

DEFUN ("or", For, Sor, 0, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
313 314 315
       doc: /* Eval args until one of them yields non-nil, then return that value.
The remaining args are not evalled at all.
If all args return nil, return nil.
316
usage: (or CONDITIONS ...)  */)
Pavel Janík's avatar
Pavel Janík committed
317
     (args)
Jim Blandy's avatar
Jim Blandy committed
318 319
     Lisp_Object args;
{
320
  register Lisp_Object val = Qnil;
Jim Blandy's avatar
Jim Blandy committed
321 322
  struct gcpro gcpro1;

323
  GCPRO1 (args);
Jim Blandy's avatar
Jim Blandy committed
324

325
  while (CONSP (args))
Jim Blandy's avatar
Jim Blandy committed
326
    {
327
      val = Feval (XCAR (args));
Jim Blandy's avatar
Jim Blandy committed
328
      if (!NILP (val))
Jim Blandy's avatar
Jim Blandy committed
329
	break;
330
      args = XCDR (args);
Jim Blandy's avatar
Jim Blandy committed
331 332 333 334 335 336 337
    }

  UNGCPRO;
  return val;
}

DEFUN ("and", Fand, Sand, 0, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
338
       doc: /* Eval args until one of them yields nil, then return nil.
Pavel Janík's avatar
Pavel Janík committed
339 340
The remaining args are not evalled at all.
If no arg yields nil, return the last arg's value.
341
usage: (and CONDITIONS ...)  */)
Pavel Janík's avatar
Pavel Janík committed
342
     (args)
Jim Blandy's avatar
Jim Blandy committed
343 344
     Lisp_Object args;
{
345
  register Lisp_Object val = Qt;
Jim Blandy's avatar
Jim Blandy committed
346 347
  struct gcpro gcpro1;

348
  GCPRO1 (args);
Jim Blandy's avatar
Jim Blandy committed
349

350
  while (CONSP (args))
Jim Blandy's avatar
Jim Blandy committed
351
    {
352
      val = Feval (XCAR (args));
Jim Blandy's avatar
Jim Blandy committed
353
      if (NILP (val))
Jim Blandy's avatar
Jim Blandy committed
354
	break;
355
      args = XCDR (args);
Jim Blandy's avatar
Jim Blandy committed
356 357 358 359 360 361 362
    }

  UNGCPRO;
  return val;
}

DEFUN ("if", Fif, Sif, 2, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
363
       doc: /* If COND yields non-nil, do THEN, else do ELSE...
Pavel Janík's avatar
Pavel Janík committed
364 365 366
Returns the value of THEN or the value of the last of the ELSE's.
THEN must be one expression, but ELSE... can be zero or more expressions.
If COND yields nil, and there are no ELSE's, the value is nil.
367
usage: (if COND THEN ELSE...)  */)
Pavel Janík's avatar
Pavel Janík committed
368
     (args)
Jim Blandy's avatar
Jim Blandy committed
369 370 371 372 373 374 375 376 377
     Lisp_Object args;
{
  register Lisp_Object cond;
  struct gcpro gcpro1;

  GCPRO1 (args);
  cond = Feval (Fcar (args));
  UNGCPRO;

Jim Blandy's avatar
Jim Blandy committed
378
  if (!NILP (cond))
Jim Blandy's avatar
Jim Blandy committed
379 380 381 382 383
    return Feval (Fcar (Fcdr (args)));
  return Fprogn (Fcdr (Fcdr (args)));
}

DEFUN ("cond", Fcond, Scond, 0, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
384 385 386 387 388 389 390 391
       doc: /* Try each clause until one succeeds.
Each clause looks like (CONDITION BODY...).  CONDITION is evaluated
and, if the value is non-nil, this clause succeeds:
then the expressions in BODY are evaluated and the last one's
value is the value of the cond-form.
If no clause succeeds, cond returns nil.
If a clause has one element, as in (CONDITION),
CONDITION's value if non-nil is returned from the cond-form.
392
usage: (cond CLAUSES...)  */)
Pavel Janík's avatar
Pavel Janík committed
393
     (args)
Jim Blandy's avatar
Jim Blandy committed
394 395 396 397 398 399 400
     Lisp_Object args;
{
  register Lisp_Object clause, val;
  struct gcpro gcpro1;

  val = Qnil;
  GCPRO1 (args);
Jim Blandy's avatar
Jim Blandy committed
401
  while (!NILP (args))
Jim Blandy's avatar
Jim Blandy committed
402 403 404
    {
      clause = Fcar (args);
      val = Feval (Fcar (clause));
Jim Blandy's avatar
Jim Blandy committed
405
      if (!NILP (val))
Jim Blandy's avatar
Jim Blandy committed
406
	{
407 408
	  if (!EQ (XCDR (clause), Qnil))
	    val = Fprogn (XCDR (clause));
Jim Blandy's avatar
Jim Blandy committed
409 410
	  break;
	}
411
      args = XCDR (args);
Jim Blandy's avatar
Jim Blandy committed
412 413 414 415 416 417 418
    }
  UNGCPRO;

  return val;
}

DEFUN ("progn", Fprogn, Sprogn, 0, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
419
       doc: /* Eval BODY forms sequentially and return value of last one.
420
usage: (progn BODY ...)  */)
Pavel Janík's avatar
Pavel Janík committed
421
     (args)
Jim Blandy's avatar
Jim Blandy committed
422 423
     Lisp_Object args;
{
424
  register Lisp_Object val = Qnil;
Jim Blandy's avatar
Jim Blandy committed
425 426
  struct gcpro gcpro1;

427
  GCPRO1 (args);
Jim Blandy's avatar
Jim Blandy committed
428

429
  while (CONSP (args))
Jim Blandy's avatar
Jim Blandy committed
430
    {
431 432
      val = Feval (XCAR (args));
      args = XCDR (args);
Jim Blandy's avatar
Jim Blandy committed
433 434 435 436 437 438 439
    }

  UNGCPRO;
  return val;
}

DEFUN ("prog1", Fprog1, Sprog1, 1, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
440 441 442
       doc: /* Eval FIRST and BODY sequentially; value from FIRST.
The value of FIRST is saved during the evaluation of the remaining args,
whose values are discarded.
443
usage: (prog1 FIRST BODY...)  */)
Pavel Janík's avatar
Pavel Janík committed
444
     (args)
Jim Blandy's avatar
Jim Blandy committed
445 446 447 448 449 450 451
     Lisp_Object args;
{
  Lisp_Object val;
  register Lisp_Object args_left;
  struct gcpro gcpro1, gcpro2;
  register int argnum = 0;

Jim Blandy's avatar
Jim Blandy committed
452
  if (NILP(args))
Jim Blandy's avatar
Jim Blandy committed
453 454 455 456 457 458 459 460 461 462 463 464 465 466
    return Qnil;

  args_left = args;
  val = Qnil;
  GCPRO2 (args, val);

  do
    {
      if (!(argnum++))
        val = Feval (Fcar (args_left));
      else
	Feval (Fcar (args_left));
      args_left = Fcdr (args_left);
    }
Jim Blandy's avatar
Jim Blandy committed
467
  while (!NILP(args_left));
Jim Blandy's avatar
Jim Blandy committed
468 469 470 471 472 473

  UNGCPRO;
  return val;
}

DEFUN ("prog2", Fprog2, Sprog2, 2, UNEVALLED, 0,
474 475 476 477
       doc: /* Eval FORM1, FORM2 and BODY sequentially; value from FORM2.
The value of FORM2 is saved during the evaluation of the
remaining args, whose values are discarded.
usage: (prog2 FORM1 FORM2 BODY...)  */)
Pavel Janík's avatar
Pavel Janík committed
478
     (args)
Jim Blandy's avatar
Jim Blandy committed
479 480 481 482 483 484 485 486 487
     Lisp_Object args;
{
  Lisp_Object val;
  register Lisp_Object args_left;
  struct gcpro gcpro1, gcpro2;
  register int argnum = -1;

  val = Qnil;

Richard M. Stallman's avatar
Richard M. Stallman committed
488
  if (NILP (args))
Jim Blandy's avatar
Jim Blandy committed
489 490 491 492 493 494 495 496 497 498 499 500 501 502
    return Qnil;

  args_left = args;
  val = Qnil;
  GCPRO2 (args, val);

  do
    {
      if (!(argnum++))
        val = Feval (Fcar (args_left));
      else
	Feval (Fcar (args_left));
      args_left = Fcdr (args_left);
    }
Richard M. Stallman's avatar
Richard M. Stallman committed
503
  while (!NILP (args_left));
Jim Blandy's avatar
Jim Blandy committed
504 505 506 507 508 509

  UNGCPRO;
  return val;
}

DEFUN ("setq", Fsetq, Ssetq, 0, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
510 511 512 513 514 515 516 517 518
       doc: /* Set each SYM to the value of its VAL.
The symbols SYM are variables; they are literal (not evaluated).
The values VAL are expressions; they are evaluated.
Thus, (setq x (1+ y)) sets `x' to the value of `(1+ y)'.
The second VAL is not computed until after the first SYM is set, and so on;
each VAL can use the new value of variables set earlier in the `setq'.
The return value of the `setq' form is the value of the last VAL.
usage: (setq SYM VAL SYM VAL ...)  */)
     (args)
Jim Blandy's avatar
Jim Blandy committed
519 520 521 522 523 524
     Lisp_Object args;
{
  register Lisp_Object args_left;
  register Lisp_Object val, sym;
  struct gcpro gcpro1;

Jim Blandy's avatar
Jim Blandy committed
525
  if (NILP(args))
Jim Blandy's avatar
Jim Blandy committed
526 527 528 529 530 531 532 533 534 535 536 537
    return Qnil;

  args_left = args;
  GCPRO1 (args);

  do
    {
      val = Feval (Fcar (Fcdr (args_left)));
      sym = Fcar (args_left);
      Fset (sym, val);
      args_left = Fcdr (Fcdr (args_left));
    }
Jim Blandy's avatar
Jim Blandy committed
538
  while (!NILP(args_left));
Jim Blandy's avatar
Jim Blandy committed
539 540 541 542

  UNGCPRO;
  return val;
}
543

Jim Blandy's avatar
Jim Blandy committed
544
DEFUN ("quote", Fquote, Squote, 1, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
545 546 547
       doc: /* Return the argument, without evaluating it.  `(quote x)' yields `x'.
usage: (quote ARG)  */)
     (args)
Jim Blandy's avatar
Jim Blandy committed
548 549 550 551
     Lisp_Object args;
{
  return Fcar (args);
}
552

Jim Blandy's avatar
Jim Blandy committed
553
DEFUN ("function", Ffunction, Sfunction, 1, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
554 555 556 557 558
       doc: /* Like `quote', but preferred for objects which are functions.
In byte compilation, `function' causes its argument to be compiled.
`quote' cannot do that.
usage: (function ARG)  */)
     (args)
Jim Blandy's avatar
Jim Blandy committed
559 560 561 562 563
     Lisp_Object args;
{
  return Fcar (args);
}

564

Jim Blandy's avatar
Jim Blandy committed
565
DEFUN ("interactive-p", Finteractive_p, Sinteractive_p, 0, 0, 0,
566
       doc: /* Return t if the function was run directly by user input.
567 568
This means that the function was called with `call-interactively'
\(which includes being called as the binding of a key)
569 570 571 572 573 574 575 576 577 578 579 580 581
and input is currently coming from the keyboard (not in keyboard macro),
and Emacs is not running in batch mode (`noninteractive' is nil).

The only known proper use of `interactive-p' is in deciding whether to
display a helpful message, or how to display it.  If you're thinking
of using it for any other purpose, it is quite likely that you're
making a mistake.  Think: what do you want to do when the command is
called from a keyboard macro?

If you want to test whether your function was called with
`call-interactively', the way to do that is by adding an extra
optional argument, and making the `interactive' spec specify non-nil
unconditionally for that argument.  (`p' is a good way to do this.)  */)
Pavel Janík's avatar
Pavel Janík committed
582
     ()
Jim Blandy's avatar
Jim Blandy committed
583
{
584
  return (INTERACTIVE && interactive_p (1)) ? Qt : Qnil;
585 586 587
}


588
DEFUN ("called-interactively-p", Fcalled_interactively_p, Scalled_interactively_p, 0, 0, 0,
589
       doc: /* Return t if the function using this was called with `call-interactively'.
590 591 592 593
This is used for implementing advice and other function-modifying
features of Emacs.

The cleanest way to test whether your function was called with
594 595 596
`call-interactively' is by adding an extra optional argument,
and making the `interactive' spec specify non-nil unconditionally
for that argument.  (`p' is a good way to do this.)  */)
597 598
     ()
{
599
  return interactive_p (1) ? Qt : Qnil;
600 601 602 603 604
}


/*  Return 1 if function in which this appears was called using
    call-interactively.
605 606 607 608 609 610 611 612 613 614

    EXCLUDE_SUBRS_P non-zero means always return 0 if the function
    called is a built-in.  */

int
interactive_p (exclude_subrs_p)
     int exclude_subrs_p;
{
  struct backtrace *btp;
  Lisp_Object fun;
Jim Blandy's avatar
Jim Blandy committed
615 616

  btp = backtrace_list;
Jim Blandy's avatar
Jim Blandy committed
617 618

  /* If this isn't a byte-compiled function, there may be a frame at
619
     the top for Finteractive_p.  If so, skip it.  */
Jim Blandy's avatar
Jim Blandy committed
620
  fun = Findirect_function (*btp->function);
621 622
  if (SUBRP (fun) && (XSUBR (fun) == &Sinteractive_p
		      || XSUBR (fun) == &Scalled_interactively_p))
Jim Blandy's avatar
Jim Blandy committed
623
    btp = btp->next;
Jim Blandy's avatar
Jim Blandy committed
624 625

  /* If we're running an Emacs 18-style byte-compiled function, there
626 627 628
     may be a frame for Fbytecode at the top level.  In any version of
     Emacs there can be Fbytecode frames for subexpressions evaluated
     inside catch and condition-case.  Skip past them.
Jim Blandy's avatar
Jim Blandy committed
629

630
     If this isn't a byte-compiled function, then we may now be
Jim Blandy's avatar
Jim Blandy committed
631
     looking at several frames for special forms.  Skip past them.  */
632 633 634
  while (btp
	 && (EQ (*btp->function, Qbytecode)
	     || btp->nargs == UNEVALLED))
Jim Blandy's avatar
Jim Blandy committed
635 636
    btp = btp->next;

Jim Blandy's avatar
Jim Blandy committed
637 638 639 640
  /* btp now points at the frame of the innermost function that isn't
     a special form, ignoring frames for Finteractive_p and/or
     Fbytecode at the top.  If this frame is for a built-in function
     (such as load or eval-region) return nil.  */
Jim Blandy's avatar
Jim Blandy committed
641
  fun = Findirect_function (*btp->function);
642 643
  if (exclude_subrs_p && SUBRP (fun))
    return 0;
644

Jim Blandy's avatar
Jim Blandy committed
645 646 647
  /* btp points to the frame of a Lisp function that called interactive-p.
     Return t if that function was called interactively.  */
  if (btp && btp->next && EQ (*btp->next->function, Qcall_interactively))
648 649
    return 1;
  return 0;
Jim Blandy's avatar
Jim Blandy committed
650 651
}

652

Jim Blandy's avatar
Jim Blandy committed
653
DEFUN ("defun", Fdefun, Sdefun, 2, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
654 655 656
       doc: /* Define NAME as a function.
The definition is (lambda ARGLIST [DOCSTRING] BODY...).
See also the function `interactive'.
657
usage: (defun NAME ARGLIST [DOCSTRING] BODY...)  */)
Pavel Janík's avatar
Pavel Janík committed
658
     (args)
Jim Blandy's avatar
Jim Blandy committed
659 660 661 662 663 664
     Lisp_Object args;
{
  register Lisp_Object fn_name;
  register Lisp_Object defn;

  fn_name = Fcar (args);
665
  CHECK_SYMBOL (fn_name);
Jim Blandy's avatar
Jim Blandy committed
666
  defn = Fcons (Qlambda, Fcdr (args));
Jim Blandy's avatar
Jim Blandy committed
667
  if (!NILP (Vpurify_flag))
Jim Blandy's avatar
Jim Blandy committed
668
    defn = Fpurecopy (defn);
669 670 671
  if (CONSP (XSYMBOL (fn_name)->function)
      && EQ (XCAR (XSYMBOL (fn_name)->function), Qautoload))
    LOADHIST_ATTACH (Fcons (Qt, fn_name));
Jim Blandy's avatar
Jim Blandy committed
672
  Ffset (fn_name, defn);
673
  LOADHIST_ATTACH (Fcons (Qdefun, fn_name));
Jim Blandy's avatar
Jim Blandy committed
674 675 676 677
  return fn_name;
}

DEFUN ("defmacro", Fdefmacro, Sdefmacro, 2, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
678
       doc: /* Define NAME as a macro.
Richard M. Stallman's avatar
Richard M. Stallman committed
679 680
The actual definition looks like
 (macro lambda ARGLIST [DOCSTRING] [DECL] BODY...).
Pavel Janík's avatar
Pavel Janík committed
681 682 683 684
When the macro is called, as in (NAME ARGS...),
the function (lambda ARGLIST BODY...) is applied to
the list ARGS... as it appears in the expression,
and the result should be a form to be evaluated instead of the original.
Richard M. Stallman's avatar
Richard M. Stallman committed
685 686 687 688 689 690 691 692

DECL is a declaration, optional, which can specify how to indent
calls to this macro and how Edebug should handle it.  It looks like this:
  (declare SPECS...)
The elements can look like this:
  (indent INDENT)
	Set NAME's `lisp-indent-function' property to INDENT.

693
  (debug DEBUG)
Richard M. Stallman's avatar
Richard M. Stallman committed
694
	Set NAME's `edebug-form-spec' property to DEBUG.  (This is
Juanma Barranquero's avatar
Juanma Barranquero committed
695
	equivalent to writing a `def-edebug-spec' for the macro.)
Richard M. Stallman's avatar
Richard M. Stallman committed
696
usage: (defmacro NAME ARGLIST [DOCSTRING] [DECL] BODY...)  */)
Pavel Janík's avatar
Pavel Janík committed
697
     (args)
Jim Blandy's avatar
Jim Blandy committed
698 699 700 701
     Lisp_Object args;
{
  register Lisp_Object fn_name;
  register Lisp_Object defn;
702
  Lisp_Object lambda_list, doc, tail;
Jim Blandy's avatar
Jim Blandy committed
703 704

  fn_name = Fcar (args);
705
  CHECK_SYMBOL (fn_name);
706 707 708 709 710 711
  lambda_list = Fcar (Fcdr (args));
  tail = Fcdr (Fcdr (args));

  doc = Qnil;
  if (STRINGP (Fcar (tail)))
    {
712 713
      doc = XCAR (tail);
      tail = XCDR (tail);
714 715 716 717 718 719 720 721 722 723 724 725
    }

  while (CONSP (Fcar (tail))
	 && EQ (Fcar (Fcar (tail)), Qdeclare))
    {
      if (!NILP (Vmacro_declaration_function))
	{
	  struct gcpro gcpro1;
	  GCPRO1 (args);
	  call2 (Vmacro_declaration_function, fn_name, Fcar (tail));
	  UNGCPRO;
	}
726

727 728 729 730 731 732 733 734
      tail = Fcdr (tail);
    }

  if (NILP (doc))
    tail = Fcons (lambda_list, tail);
  else
    tail = Fcons (lambda_list, Fcons (doc, tail));
  defn = Fcons (Qmacro, Fcons (Qlambda, tail));
735

Jim Blandy's avatar
Jim Blandy committed
736
  if (!NILP (Vpurify_flag))
Jim Blandy's avatar
Jim Blandy committed
737
    defn = Fpurecopy (defn);
738 739 740
  if (CONSP (XSYMBOL (fn_name)->function)
      && EQ (XCAR (XSYMBOL (fn_name)->function), Qautoload))
    LOADHIST_ATTACH (Fcons (Qt, fn_name));
Jim Blandy's avatar
Jim Blandy committed
741
  Ffset (fn_name, defn);
742
  LOADHIST_ATTACH (Fcons (Qdefun, fn_name));
Jim Blandy's avatar
Jim Blandy committed
743 744 745
  return fn_name;
}

Gerd Moellmann's avatar
Gerd Moellmann committed
746

747
DEFUN ("defvaralias", Fdefvaralias, Sdefvaralias, 2, 3, 0,
748 749 750 751 752 753 754 755 756 757
       doc: /* Make NEW-ALIAS a variable alias for symbol BASE-VARIABLE.
Setting the value of NEW-ALIAS will subsequently set the value of BASE-VARIABLE,
 and getting the value of NEW-ALIAS will return the value BASE-VARIABLE has.
Third arg DOCSTRING, if non-nil, is documentation for NEW-ALIAS.  If it is
 omitted or nil, NEW-ALIAS gets the documentation string of BASE-VARIABLE,
 or of the variable at the end of the chain of aliases, if BASE-VARIABLE is
 itself an alias.
The return value is BASE-VARIABLE.  */)
     (new_alias, base_variable, docstring)
     Lisp_Object new_alias, base_variable, docstring;
Gerd Moellmann's avatar
Gerd Moellmann committed
758 759
{
  struct Lisp_Symbol *sym;
760

761 762
  CHECK_SYMBOL (new_alias);
  CHECK_SYMBOL (base_variable);
Gerd Moellmann's avatar
Gerd Moellmann committed
763

764
  if (SYMBOL_CONSTANT_P (new_alias))
Gerd Moellmann's avatar
Gerd Moellmann committed
765 766
    error ("Cannot make a constant an alias");

767
  sym = XSYMBOL (new_alias);
Gerd Moellmann's avatar
Gerd Moellmann committed
768
  sym->indirect_variable = 1;
769 770 771
  sym->value = base_variable;
  sym->constant = SYMBOL_CONSTANT_P (base_variable);
  LOADHIST_ATTACH (new_alias);
772
  if (!NILP (docstring))
773
    Fput (new_alias, Qvariable_documentation, docstring);
774
  else
775
    Fput (new_alias, Qvariable_documentation, Qnil);
776

777
  return base_variable;
Gerd Moellmann's avatar
Gerd Moellmann committed
778 779 780
}


Jim Blandy's avatar
Jim Blandy committed
781
DEFUN ("defvar", Fdefvar, Sdefvar, 1, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
782 783 784 785 786 787 788 789 790 791 792 793 794
       doc: /* Define SYMBOL as a variable.
You are not required to define a variable in order to use it,
but the definition can supply documentation and an initial value
in a way that tags can recognize.

INITVALUE is evaluated, and used to set SYMBOL, only if SYMBOL's value is void.
If SYMBOL is buffer-local, its default value is what is set;
 buffer-local values are not affected.
INITVALUE and DOCSTRING are optional.
If DOCSTRING starts with *, this variable is identified as a user option.
 This means that M-x set-variable recognizes it.
 See also `user-variable-p'.
If INITVALUE is missing, SYMBOL's value is not set.
795 796 797 798 799 800 801

If SYMBOL has a local binding, then this form affects the local
binding.  This is usually not what you want.  Thus, if you need to
load a file defining variables, with this form or with `defconst' or
`defcustom', you should always load that file _outside_ any bindings
for these variables.  \(`defconst' and `defcustom' behave similarly in
this respect.)
802
usage: (defvar SYMBOL &optional INITVALUE DOCSTRING)  */)
Pavel Janík's avatar
Pavel Janík committed
803
     (args)
Jim Blandy's avatar
Jim Blandy committed
804 805
     Lisp_Object args;
{
806
  register Lisp_Object sym, tem, tail;
Jim Blandy's avatar
Jim Blandy committed
807 808

  sym = Fcar (args);
809
  if (SYMBOL_CONSTANT_P (sym))
810 811 812 813 814 815 816 817 818 819
    {
      /* For updward compatibility, allow (defvar :foo (quote :foo)).  */
      tem = Fcar (Fcdr (args));
      if (! (CONSP (tem)
	     && EQ (XCAR (tem), Qquote)
	     && CONSP (XCDR (tem))
	     && EQ (XCAR (XCDR (tem)), sym)))
	error ("Constant symbol `%s' specified in defvar",
	       SDATA (SYMBOL_NAME (sym)));
    }
820

821 822
  tail = Fcdr (args);
  if (!NILP (Fcdr (Fcdr (tail))))
823
    error ("Too many arguments");
824

825
  tem = Fdefault_boundp (sym);
826
  if (!NILP (tail))
Jim Blandy's avatar
Jim Blandy committed
827
    {
Jim Blandy's avatar
Jim Blandy committed
828
      if (NILP (tem))
829
	Fset_default (sym, Feval (Fcar (tail)));
830 831 832
      else
	{ /* Check if there is really a global binding rather than just a let
	     binding that shadows the global unboundness of the var.  */
833
	  volatile struct specbinding *pdl = specpdl_ptr;
834 835 836 837 838 839 840 841 842 843 844
	  while (--pdl >= specpdl)
	    {
	      if (EQ (pdl->symbol, sym) && !pdl->func
		  && EQ (pdl->old_value, Qunbound))
		{
		  message_with_string ("Warning: defvar ignored because %s is let-bound",
				       SYMBOL_NAME (sym), 1);
		  break;
		}
	    }
	}
845
      tail = Fcdr (tail);
846 847
      tem = Fcar (tail);
      if (!NILP (tem))
848 849 850 851 852
	{
	  if (!NILP (Vpurify_flag))
	    tem = Fpurecopy (tem);
	  Fput (sym, Qvariable_documentation, tem);
	}
853
      LOADHIST_ATTACH (sym);
Jim Blandy's avatar
Jim Blandy committed
854
    }
855
  else
856 857 858
    /* Simple (defvar <var>) should not count as a definition at all.
       It could get in the way of other definitions, and unloading this
       package could try to make the variable unbound.  */
Andreas Schwab's avatar
Andreas Schwab committed
859 860
    ;

Jim Blandy's avatar
Jim Blandy committed
861 862 863 864
  return sym;
}

DEFUN ("defconst", Fdefconst, Sdefconst, 2, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
865 866 867 868 869 870
       doc: /* Define SYMBOL as a constant variable.
The intent is that neither programs nor users should ever change this value.
Always sets the value of SYMBOL to the result of evalling INITVALUE.
If SYMBOL is buffer-local, its default value is what is set;
 buffer-local values are not affected.
DOCSTRING is optional.
871 872 873 874

If SYMBOL has a local binding, then this form sets the local binding's
value.  However, you should normally not make local bindings for
variables defined with this form.
875
usage: (defconst SYMBOL INITVALUE [DOCSTRING])  */)
Pavel Janík's avatar
Pavel Janík committed
876
     (args)
Jim Blandy's avatar
Jim Blandy committed
877 878 879 880 881
     Lisp_Object args;
{
  register Lisp_Object sym, tem;

  sym = Fcar (args);
882
  if (!NILP (Fcdr (Fcdr (Fcdr (args)))))
883
    error ("Too many arguments");
884

885 886 887 888
  tem = Feval (Fcar (Fcdr (args)));
  if (!NILP (Vpurify_flag))
    tem = Fpurecopy (tem);
  Fset_default (sym, tem);
Jim Blandy's avatar
Jim Blandy committed
889
  tem = Fcar (Fcdr (Fcdr (args)));
Jim Blandy's avatar
Jim Blandy committed
890
  if (!NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
891
    {
Jim Blandy's avatar
Jim Blandy committed
892
      if (!NILP (Vpurify_flag))
Jim Blandy's avatar
Jim Blandy committed
893 894 895
	tem = Fpurecopy (tem);
      Fput (sym, Qvariable_documentation, tem);
    }
896
  LOADHIST_ATTACH (sym);
Jim Blandy's avatar
Jim Blandy committed
897 898 899
  return sym;
}

900 901 902 903 904 905 906 907
/* Error handler used in Fuser_variable_p.  */
static Lisp_Object
user_variable_p_eh (ignore)
     Lisp_Object ignore;
{
  return Qnil;
}

Jim Blandy's avatar
Jim Blandy committed
908
DEFUN ("user-variable-p", Fuser_variable_p, Suser_variable_p, 1, 1, 0,
909
       doc: /* Return t if VARIABLE is intended to be set and modified by users.
Pavel Janík's avatar
Pavel Janík committed
910
\(The alternative is a variable used internally in a Lisp program.)
911 912 913 914 915 916 917
A variable is a user variable if
\(1) the first character of its documentation is `*', or
\(2) it is customizable (its property list contains a non-nil value
    of `standard-value' or `custom-autoload'), or
\(3) it is an alias for another user variable.
Return nil if VARIABLE is an alias and there is a loop in the
chain of symbols.  */)
Pavel Janík's avatar
Pavel Janík committed
918
     (variable)
Jim Blandy's avatar
Jim Blandy committed
919 920 921
     Lisp_Object variable;
{
  Lisp_Object documentation;
922

923 924 925
  if (!SYMBOLP (variable))
      return Qnil;

926 927 928 929 930 931 932 933 934 935 936 937 938 939 940 941 942 943 944 945 946 947 948 949 950 951 952 953 954 955 956
  /* If indirect and there's an alias loop, don't check anything else.  */
  if (XSYMBOL (variable)->indirect_variable
      && NILP (internal_condition_case_1 (indirect_variable, variable,
                                          Qt, user_variable_p_eh)))
    return Qnil;

  while (1)
    {
      documentation = Fget (variable, Qvariable_documentation);
      if (INTEGERP (documentation) && XINT (documentation) < 0)
        return Qt;
      if (STRINGP (documentation)
          && ((unsigned char) SREF (documentation, 0) == '*'))
        return Qt;
      /* If it is (STRING . INTEGER), a negative integer means a user variable.  */
      if (CONSP (documentation)
          && STRINGP (XCAR (documentation))
          && INTEGERP (XCDR (documentation))
          && XINT (XCDR (documentation)) < 0)
        return Qt;
      /* Customizable?  See `custom-variable-p'.  */
      if ((!NILP (Fget (variable, intern ("standard-value"))))
          || (!NILP (Fget (variable, intern ("custom-autoload")))))
        return Qt;

      if (!XSYMBOL (variable)->indirect_variable)
        return Qnil;

      /* An indirect variable?  Let's follow the chain.  */
      variable = XSYMBOL (variable)->value;
    }
957
}
Jim Blandy's avatar
Jim Blandy committed
958 959

DEFUN ("let*", FletX, SletX, 1, UNEVALLED, 0,
Pavel Janík's avatar
Pavel Janík committed
960 961 962 963 964
       doc: /* Bind variables according to VARLIST then eval BODY.
The value of the last form in BODY is returned.
Each element of VARLIST is a symbol (which is bound to nil)
or a list (SYMBOL VALUEFORM) (which binds SYMBOL to the value of VALUEFORM).
Each VALUEFORM can refer to the symbols already bound by this VARLIST.
965
usage: (let* VARLIST BODY...)  */)
Pavel Janík's avatar
Pavel Janík committed
966
     (args)
Jim Blandy's avatar
Jim Blandy committed
967 968 969
     Lisp_Object args;
{
  Lisp_Object varlist, val, elt;
Juanma Barranquero's avatar
Juanma Barranquero committed
970
  int count = SPECPDL_INDEX ();
Jim Blandy's avatar
Jim Blandy committed
971 972 973 974 975
  struct gcpro gcpro1, gcpro2, gcpro3;

  GCPRO3 (args, elt, varlist);

  varlist = Fcar (args);
Jim Blandy's avatar
Jim Blandy committed
976
  while (!NILP (varlist))