lread.c 118 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp parsing and input streams.
2 3
   Copyright (C) 1985, 1986, 1987, 1988, 1989, 1993, 1994, 1995,
                 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
Glenn Morris's avatar
Glenn Morris committed
4
                 2005, 2006, 2007 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7 8 9

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
10
the Free Software Foundation; either version 3, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
11 12 13 14 15 16 17 18 19
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
20 21
the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
Boston, MA 02110-1301, USA.  */
Jim Blandy's avatar
Jim Blandy committed
22 23


Richard M. Stallman's avatar
Richard M. Stallman committed
24
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
25 26 27 28
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
29
#include <errno.h>
30
#include <setjmp.h>
Jim Blandy's avatar
Jim Blandy committed
31
#include "lisp.h"
32
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
33
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
34
#include "charset.h"
35
#include <epaths.h>
Jim Blandy's avatar
Jim Blandy committed
36
#include "commands.h"
Jim Blandy's avatar
Jim Blandy committed
37
#include "keyboard.h"
38
#include "frame.h"
39
#include "termhooks.h"
40
#include "coding.h"
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
41
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
42 43 44 45 46

#ifdef lint
#include <sys/inode.h>
#endif /* lint */

47 48 49 50 51 52 53
#ifdef MSDOS
#if __DJGPP__ < 2
#include <unistd.h>	/* to get X_OK */
#endif
#include "msdos.h"
#endif

Andreas Schwab's avatar
Andreas Schwab committed
54 55 56 57
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
58 59 60 61 62 63
#ifndef X_OK
#define X_OK 01
#endif

#include <math.h>

Richard M. Stallman's avatar
Richard M. Stallman committed
64 65 66 67
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Dave Love's avatar
Dave Love committed
68 69 70
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
Richard M. Stallman's avatar
Richard M. Stallman committed
71 72 73 74
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

75
#ifdef HAVE_FSEEKO
76 77 78 79 80 81 82
#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

83
#ifndef USE_CRT_DLL
84
extern int errno;
85
#endif
86

87
Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
Jim Blandy's avatar
Jim Blandy committed
88
Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
89
Lisp_Object Qascii_character, Qload, Qload_file_name;
90
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
91
Lisp_Object Qinhibit_file_name_operation;
92
Lisp_Object Qeval_buffer_list, Veval_buffer_list;
93
Lisp_Object Qfile_truename, Qdo_after_load_evaluation; /* ACM 2006/5/16 */
94 95

extern Lisp_Object Qevent_symbol_element_mask;
96
extern Lisp_Object Qfile_exists_p;
Jim Blandy's avatar
Jim Blandy committed
97

Glenn Morris's avatar
Glenn Morris committed
98
/* non-zero if inside `load' */
Jim Blandy's avatar
Jim Blandy committed
99 100
int load_in_progress;

101 102 103
/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

104
/* Search path and suffixes for files to be loaded. */
105
Lisp_Object Vload_path, Vload_suffixes, Vload_file_rep_suffixes;
Jim Blandy's avatar
Jim Blandy committed
106

Karl Heuer's avatar
Karl Heuer committed
107 108 109
/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

110 111 112 113
/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

114
/* This is used to build the load history. */
115 116
Lisp_Object Vcurrent_load_list;

117 118 119
/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

120 121 122
/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

123 124 125
/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

126 127 128 129 130 131
/* The association list of objects read with the #n=object form.
   Each member of the list has the form (n . object), and is used to
   look up the object for the corresponding #n# construct.
   It must be set to nil before all top-level calls to read0.  */
Lisp_Object read_objects;

132 133 134
/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

135 136 137
/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

138
/* Function to use for loading an Emacs Lisp source file (not
Karl Heuer's avatar
Karl Heuer committed
139 140 141
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

142 143 144
/* List of all DEFVAR_BOOL variables.  Used by the byte optimizer.  */
Lisp_Object Vbyte_boolean_vars;

145 146 147 148 149 150 151
/* Whether or not to add a `read-positions' property to symbols
   read. */
Lisp_Object Vread_with_symbol_positions;

/* List of (SYMBOL . POSITION) accumulated so far. */
Lisp_Object Vread_symbol_positions_list;

152 153 154
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

155
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
156 157 158 159 160
static FILE *instream;

/* When nonzero, read conses in pure space */
static int read_pure;

161
/* For use within read-from-string (this reader is non-reentrant!!)  */
Jim Blandy's avatar
Jim Blandy committed
162
static int read_from_string_index;
163
static int read_from_string_index_byte;
Jim Blandy's avatar
Jim Blandy committed
164
static int read_from_string_limit;
165

166 167 168
/* Number of bytes left to read in the buffer character
   that `readchar' has already advanced over.  */
static int readchar_backlog;
169 170 171
/* Number of characters read in the current call to Fread or
   Fread_from_string. */
static int readchar_count;
172

173
/* This contains the last string skipped with #@.  */
174 175 176 177 178 179
static char *saved_doc_string;
/* Length of buffer allocated in saved_doc_string.  */
static int saved_doc_string_size;
/* Length of actual data in saved_doc_string.  */
static int saved_doc_string_length;
/* This is the file position that string came from.  */
180
static file_offset saved_doc_string_position;
181

182 183 184 185 186 187 188 189 190
/* This contains the previous string skipped with #@.
   We copy it from saved_doc_string when a new string
   is put in saved_doc_string.  */
static char *prev_saved_doc_string;
/* Length of buffer allocated in prev_saved_doc_string.  */
static int prev_saved_doc_string_size;
/* Length of actual data in prev_saved_doc_string.  */
static int prev_saved_doc_string_length;
/* This is the file position that string came from.  */
191
static file_offset prev_saved_doc_string_position;
192

193 194 195 196 197
/* Nonzero means inside a new-style backquote
   with no surrounding parentheses.
   Fread initializes this to zero, so we need not specbind it
   or worry about what happens to it when there is an error.  */
static int new_backquote_flag;
198
static Lisp_Object Vold_style_backquotes, Qold_style_backquotes;
199 200 201 202

/* A list of file names for files being loaded in Fload.  Used to
   check for recursive loads.  */

Lute Kamstra's avatar
Lute Kamstra committed
203
static Lisp_Object Vloads_in_progress;
204

205 206 207 208 209 210 211 212
/* Non-zero means load dangerous compiled Lisp files.  */

int load_dangerous_libraries;

/* A regular expression used to detect files compiled with Emacs.  */

static Lisp_Object Vbytecomp_version_regexp;

Gerd Moellmann's avatar
Gerd Moellmann committed
213
static void to_multibyte P_ ((char **, char **, int *));
214
static void readevalloop P_ ((Lisp_Object, FILE*, Lisp_Object,
215
			      Lisp_Object (*) (), int,
216
			      Lisp_Object, Lisp_Object,
217 218 219 220
			      Lisp_Object, Lisp_Object));
static Lisp_Object load_unwind P_ ((Lisp_Object));
static Lisp_Object load_descriptor_unwind P_ ((Lisp_Object));

221
static void invalid_syntax P_ ((const char *, int)) NO_RETURN;
222
static void end_of_file_error P_ (()) NO_RETURN;
223

Jim Blandy's avatar
Jim Blandy committed
224 225 226

/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
227 228
   UNREAD(c) to unread c to be read again.

229 230 231
   The READCHAR and UNREAD macros are meant for reading/unreading a
   byte code; they do not handle multibyte characters.  The caller
   should manage them if necessary.
232

233 234 235 236
   [ Actually that seems to be a lie; READCHAR will definitely read
     multibyte characters from buffer sources, at least.  Is the
     comment just out of date?
     -- Colin Walters <walters@gnu.org>, 22 May 2002 16:36:50 -0400 ]
Karl Heuer's avatar
Karl Heuer committed
237
 */
Jim Blandy's avatar
Jim Blandy committed
238 239 240 241 242 243 244 245 246

#define READCHAR readchar (readcharfun)
#define UNREAD(c) unreadchar (readcharfun, c)

static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
247
  register int c;
Jim Blandy's avatar
Jim Blandy committed
248

249
  readchar_count++;
250

251
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
252
    {
253
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
254

255 256
      int pt_byte = BUF_PT_BYTE (inbuffer);
      int orig_pt_byte = pt_byte;
257

258 259 260 261 262 263 264 265
      if (readchar_backlog > 0)
	/* We get the address of the byte just passed,
	   which is the last byte of the character.
	   The other bytes in this character are consecutive with it,
	   because the gap can't be in the middle of a character.  */
	return *(BUF_BYTE_ADDRESS (inbuffer, BUF_PT_BYTE (inbuffer) - 1)
		 - --readchar_backlog);

266 267
      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
Jim Blandy's avatar
Jim Blandy committed
268

269 270
      readchar_backlog = -1;

271 272
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
273
	  /* Fetch the character code from the buffer.  */
274 275 276 277 278 279 280 281
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, pt_byte);
	  BUF_INC_POS (inbuffer, pt_byte);
	  c = STRING_CHAR (p, pt_byte - orig_pt_byte);
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, pt_byte);
	  pt_byte++;
282
	}
283
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
284

285
      return c;
Jim Blandy's avatar
Jim Blandy committed
286
    }
287
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
288
    {
289
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
290

291 292
      int bytepos = marker_byte_position (readcharfun);
      int orig_bytepos = bytepos;
293

294 295 296 297 298 299 300 301
      if (readchar_backlog > 0)
	/* We get the address of the byte just passed,
	   which is the last byte of the character.
	   The other bytes in this character are consecutive with it,
	   because the gap can't be in the middle of a character.  */
	return *(BUF_BYTE_ADDRESS (inbuffer, XMARKER (readcharfun)->bytepos - 1)
		 - --readchar_backlog);

302 303
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
304

305 306
      readchar_backlog = -1;

307 308
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
309
	  /* Fetch the character code from the buffer.  */
310 311 312 313 314 315 316 317
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, bytepos);
	  BUF_INC_POS (inbuffer, bytepos);
	  c = STRING_CHAR (p, bytepos - orig_bytepos);
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, bytepos);
	  bytepos++;
318 319
	}

320 321 322 323
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
324
    }
325 326 327 328

  if (EQ (readcharfun, Qlambda))
    return read_bytecode_char (0);

Jim Blandy's avatar
Jim Blandy committed
329
  if (EQ (readcharfun, Qget_file_char))
330
    {
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
331
      BLOCK_INPUT;
332 333 334 335 336
      c = getc (instream);
#ifdef EINTR
      /* Interrupted reads have been observed while reading over the network */
      while (c == EOF && ferror (instream) && errno == EINTR)
	{
337
	  UNBLOCK_INPUT;
338
	  QUIT;
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
339
	  BLOCK_INPUT;
340
	  clearerr (instream);
341 342 343
	  c = getc (instream);
	}
#endif
344
      UNBLOCK_INPUT;
345 346
      return c;
    }
Jim Blandy's avatar
Jim Blandy committed
347

348
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
349
    {
350
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
351
	c = -1;
352
      else
353 354 355
	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
356

Jim Blandy's avatar
Jim Blandy committed
357 358 359 360 361
      return c;
    }

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
362
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
363 364 365 366 367 368 369 370 371 372 373 374
    return -1;
  return XINT (tem);
}

/* Unread the character C in the way appropriate for the stream READCHARFUN.
   If the stream is a user function, call it with the char as argument.  */

static void
unreadchar (readcharfun, c)
     Lisp_Object readcharfun;
     int c;
{
375
  readchar_count--;
376 377 378 379
  if (c == -1)
    /* Don't back up the pointer if we're unreading the end-of-input mark,
       since readchar didn't advance it when we read it.  */
    ;
380
  else if (BUFFERP (readcharfun))
381
    {
382 383
      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
384

385 386
      if (readchar_backlog >= 0)
	readchar_backlog++;
387
      else
388 389 390 391 392 393
	{
	  BUF_PT (b)--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
394

395 396
	  BUF_PT_BYTE (b) = bytepos;
	}
397
    }
398
  else if (MARKERP (readcharfun))
399
    {
400 401
      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
402

403 404
      if (readchar_backlog >= 0)
	readchar_backlog++;
405
      else
406 407 408 409 410 411
	{
	  XMARKER (readcharfun)->charpos--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
412

413 414
	  XMARKER (readcharfun)->bytepos = bytepos;
	}
415
    }
416
  else if (STRINGP (readcharfun))
417 418 419 420 421
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
422 423
  else if (EQ (readcharfun, Qlambda))
    read_bytecode_char (1);
Jim Blandy's avatar
Jim Blandy committed
424
  else if (EQ (readcharfun, Qget_file_char))
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
425 426 427 428 429
    {
      BLOCK_INPUT;
      ungetc (c, instream);
      UNBLOCK_INPUT;
    }
Jim Blandy's avatar
Jim Blandy committed
430 431 432 433
  else
    call1 (readcharfun, make_number (c));
}

434 435 436
static Lisp_Object read_internal_start P_ ((Lisp_Object, Lisp_Object,
					    Lisp_Object));
static Lisp_Object read0 P_ ((Lisp_Object));
437
static Lisp_Object read1 P_ ((Lisp_Object, int *, int));
438 439 440 441 442 443 444 445 446 447

static Lisp_Object read_list P_ ((int, Lisp_Object));
static Lisp_Object read_vector P_ ((Lisp_Object, int));
static int read_multibyte P_ ((int, Lisp_Object));

static Lisp_Object substitute_object_recurse P_ ((Lisp_Object, Lisp_Object,
						  Lisp_Object));
static void substitute_object_in_subtree P_ ((Lisp_Object,
					      Lisp_Object));
static void substitute_in_interval P_ ((INTERVAL, Lisp_Object));
448

Jim Blandy's avatar
Jim Blandy committed
449

450
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
451

452 453 454 455 456 457 458 459 460 461 462 463 464
/* Read input events until we get one that's acceptable for our purposes.

   If NO_SWITCH_FRAME is non-zero, switch-frame events are stashed
   until we get a character we like, and then stuffed into
   unread_switch_frame.

   If ASCII_REQUIRED is non-zero, we check function key events to see
   if the unmodified version of the symbol has a Qascii_character
   property, and use that character, if present.

   If ERROR_NONASCII is non-zero, we signal an error if the input we
   get isn't an ASCII character with modifiers.  If it's zero but
   ASCII_REQUIRED is non-zero, we just re-read until we get an ASCII
465 466 467
   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
468 469 470 471
   if the character warrants that.

   If SECONDS is a number, we wait that many seconds for input, and
   return Qnil if no input arrives within that time.  */
472

473
Lisp_Object
474
read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
475
		     input_method, seconds)
476
     int no_switch_frame, ascii_required, error_nonascii, input_method;
477
     Lisp_Object seconds;
478
{
479
  Lisp_Object val, delayed_switch_frame;
480
  EMACS_TIME end_time;
481

482
#ifdef HAVE_WINDOW_SYSTEM
483 484
  if (display_hourglass_p)
    cancel_hourglass ();
485
#endif
486

487
  delayed_switch_frame = Qnil;
488

489 490 491 492 493
  /* Compute timeout.  */
  if (NUMBERP (seconds))
    {
      EMACS_TIME wait_time;
      int sec, usec;
Karoly Lorentey's avatar
Karoly Lorentey committed
494
      double duration = extract_float (seconds);
495 496 497 498 499 500 501 502

      sec  = (int) duration;
      usec = (duration - sec) * 1000000;
      EMACS_GET_TIME (end_time);
      EMACS_SET_SECS_USECS (wait_time, sec, usec);
      EMACS_ADD_TIME (end_time, end_time, wait_time);
    }

Karoly Lorentey's avatar
Karoly Lorentey committed
503
/* Read until we get an acceptable event.  */
504
 retry:
505
  do
Karoly Lorentey's avatar
Karoly Lorentey committed
506 507
    val = read_char (0, 0, 0, (input_method ? Qnil : Qt), 0,
		     NUMBERP (seconds) ? &end_time : NULL);
508
  while (INTEGERP (val) && XINT (val) == -2); /* wrong_kboard_jmpbuf */
509

510
  if (BUFFERP (val))
511 512
    goto retry;

513
  /* switch-frame events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
514
     character.  This is better than signaling an error just because
515 516 517 518 519
     the last characters were typed to a separate minibuffer frame,
     for example.  Eventually, some code which can deal with
     switch-frame events will read it and process it.  */
  if (no_switch_frame
      && EVENT_HAS_PARAMETERS (val)
520
      && EQ (EVENT_HEAD_KIND (EVENT_HEAD (val)), Qswitch_frame))
521 522 523 524 525
    {
      delayed_switch_frame = val;
      goto retry;
    }

526
  if (ascii_required && !(NUMBERP (seconds) && NILP (val)))
527 528
    {
      /* Convert certain symbols to their ASCII equivalents.  */
529
      if (SYMBOLP (val))
530
	{
531
	  Lisp_Object tem, tem1;
532 533 534 535 536 537 538
	  tem = Fget (val, Qevent_symbol_element_mask);
	  if (!NILP (tem))
	    {
	      tem1 = Fget (Fcar (tem), Qascii_character);
	      /* Merge this symbol's modifier bits
		 with the ASCII equivalent of its basic code.  */
	      if (!NILP (tem1))
539
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
540 541
	    }
	}
542

543
      /* If we don't have a character now, deal with it appropriately.  */
544
      if (!INTEGERP (val))
545 546 547
	{
	  if (error_nonascii)
	    {
548
	      Vunread_command_events = Fcons (val, Qnil);
549 550 551 552 553 554 555 556 557 558
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

  if (! NILP (delayed_switch_frame))
    unread_switch_frame = delayed_switch_frame;

559 560
#if 0

561
#ifdef HAVE_WINDOW_SYSTEM
562 563
  if (display_hourglass_p)
    start_hourglass ();
564
#endif
565 566 567

#endif

568 569 570
  return val;
}

571
DEFUN ("read-char", Fread_char, Sread_char, 0, 3, 0,
572 573 574 575 576 577 578 579 580 581 582 583
       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.
If the user generates an event which is not a character (i.e. a mouse
click or function key event), `read-char' signals an error.  As an
exception, switch-frame events are put off until non-ASCII events can
be read.
If you want to read non-character events, or ignore them, call
`read-event' or `read-char-exclusive' instead.

If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
584 585 586 587 588 589 590
is used for reading a character.
If the optional argument SECONDS is non-nil, it should be a number
specifying the maximum number of seconds to wait for input.  If no
input arrives in that time, return nil.  SECONDS may be a
floating-point value.  */)
     (prompt, inherit_input_method, seconds)
     Lisp_Object prompt, inherit_input_method, seconds;
Jim Blandy's avatar
Jim Blandy committed
591
{
592 593
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
594
  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
595 596
}

597
DEFUN ("read-event", Fread_event, Sread_event, 0, 3, 0,
598 599 600 601
       doc: /* Read an event object from the input stream.
If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
602 603 604 605 606 607 608
is used for reading a character.
If the optional argument SECONDS is non-nil, it should be a number
specifying the maximum number of seconds to wait for input.  If no
input arrives in that time, return nil.  SECONDS may be a
floating-point value.  */)
     (prompt, inherit_input_method, seconds)
     Lisp_Object prompt, inherit_input_method, seconds;
Jim Blandy's avatar
Jim Blandy committed
609
{
610 611
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
612
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
613 614
}

615
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 3, 0,
616 617 618 619 620 621
       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.  Non-character events are ignored.

If the optional argument PROMPT is non-nil, display that as a prompt.
If the optional argument INHERIT-INPUT-METHOD is non-nil and some
input method is turned on in the current buffer, that input method
622 623 624 625 626 627 628
is used for reading a character.
If the optional argument SECONDS is non-nil, it should be a number
specifying the maximum number of seconds to wait for input.  If no
input arrives in that time, return nil.  SECONDS may be a
floating-point value.  */)
     (prompt, inherit_input_method, seconds)
     Lisp_Object prompt, inherit_input_method, seconds;
Jim Blandy's avatar
Jim Blandy committed
629
{
630 631
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
632
  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
633 634 635
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
636 637
       doc: /* Don't use this yourself.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
638 639
{
  register Lisp_Object val;
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
640
  BLOCK_INPUT;
641
  XSETINT (val, getc (instream));
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
642
  UNBLOCK_INPUT;
Jim Blandy's avatar
Jim Blandy committed
643 644
  return val;
}
645 646


647

648
/* Value is non-zero if the file associated with file descriptor FD
649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684
   is a compiled Lisp file that's safe to load.  Only files compiled
   with Emacs are safe to load.  Files compiled with XEmacs can lead
   to a crash in Fbyte_code because of an incompatible change in the
   byte compiler.  */

static int
safe_to_load_p (fd)
     int fd;
{
  char buf[512];
  int nbytes, i;
  int safe_p = 1;

  /* Read the first few bytes from the file, and look for a line
     specifying the byte compiler version used.  */
  nbytes = emacs_read (fd, buf, sizeof buf - 1);
  if (nbytes > 0)
    {
      buf[nbytes] = '\0';

      /* Skip to the next newline, skipping over the initial `ELC'
	 with NUL bytes following it.  */
      for (i = 0; i < nbytes && buf[i] != '\n'; ++i)
	;

      if (i < nbytes
	  && fast_c_string_match_ignore_case (Vbytecomp_version_regexp,
					      buf + i) < 0)
	safe_p = 0;
    }

  lseek (fd, 0, SEEK_SET);
  return safe_p;
}


685 686 687 688 689 690 691 692 693 694
/* Callback for record_unwind_protect.  Restore the old load list OLD,
   after loading a file successfully.  */

static Lisp_Object
record_load_unwind (old)
     Lisp_Object old;
{
  return Vloads_in_progress = old;
}

695 696 697 698 699 700 701 702
/* This handler function is used via internal_condition_case_1.  */

static Lisp_Object
load_error_handler (data)
     Lisp_Object data;
{
  return Qnil;
}
703

704 705 706 707 708 709
static Lisp_Object
load_warn_old_style_backquotes (file)
     Lisp_Object file;
{
  if (!NILP (Vold_style_backquotes))
    {
710
      Lisp_Object args[2];
711
      args[0] = build_string ("Loading `%s': old-style backquotes detected!");
712 713 714 715 716 717
      args[1] = file;
      Fmessage (2, args);
    }
  return Qnil;
}

718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739
DEFUN ("get-load-suffixes", Fget_load_suffixes, Sget_load_suffixes, 0, 0, 0,
       doc: /* Return the suffixes that `load' should try if a suffix is \
required.
This uses the variables `load-suffixes' and `load-file-rep-suffixes'.  */)
     ()
{
  Lisp_Object lst = Qnil, suffixes = Vload_suffixes, suffix, ext;
  while (CONSP (suffixes))
    {
      Lisp_Object exts = Vload_file_rep_suffixes;
      suffix = XCAR (suffixes);
      suffixes = XCDR (suffixes);
      while (CONSP (exts))
	{
	  ext = XCAR (exts);
	  exts = XCDR (exts);
	  lst = Fcons (concat2 (suffix, ext), lst);
	}
    }
  return Fnreverse (lst);
}

740
DEFUN ("load", Fload, Sload, 1, 5, 0,
741 742
       doc: /* Execute a file of Lisp code named FILE.
First try FILE with `.elc' appended, then try with `.el',
743
then try FILE unmodified (the exact suffixes in the exact order are
744
determined by `load-suffixes').  Environment variable references in
745
FILE are replaced with their values by calling `substitute-in-file-name'.
746
This function searches the directories in `load-path'.
747

748
If optional second arg NOERROR is non-nil,
749
report no error if FILE doesn't exist.
750
Print messages at start and end of loading unless
751
optional third arg NOMESSAGE is non-nil.
752
If optional fourth arg NOSUFFIX is non-nil, don't try adding
753
suffixes `.elc' or `.el' to the specified name FILE.
754
If optional fifth arg MUST-SUFFIX is non-nil, insist on
755 756 757 758 759 760 761 762 763 764 765 766 767 768 769
the suffix `.elc' or `.el'; don't accept just FILE unless
it ends in one of those suffixes or includes a directory name.

If this function fails to find a file, it may look for different
representations of that file before trying another file.
It does so by adding the non-empty suffixes in `load-file-rep-suffixes'
to the file name.  Emacs uses this feature mainly to find compressed
versions of files when Auto Compression mode is enabled.

The exact suffixes that this function tries out, in the exact order,
are given by the value of the variable `load-file-rep-suffixes' if
NOSUFFIX is non-nil and by the return value of the function
`get-load-suffixes' if MUST-SUFFIX is non-nil.  If both NOSUFFIX and
MUST-SUFFIX are nil, this function first tries out the latter suffixes
and then the former.
770 771 772 773 774

Loading a file records its definitions, and its `provide' and
`require' calls, in an element of `load-history' whose
car is the file name loaded.  See `load-history'.

775
Return t if the file exists and loads successfully.  */)
776
     (file, noerror, nomessage, nosuffix, must_suffix)
777
     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
Jim Blandy's avatar
Jim Blandy committed
778 779 780
{
  register FILE *stream;
  register int fd = -1;
Juanma Barranquero's avatar
Juanma Barranquero committed
781
  int count = SPECPDL_INDEX ();
782 783
  struct gcpro gcpro1, gcpro2, gcpro3;
  Lisp_Object found, efound, hist_file_name;
784 785 786 787
  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
788
  Lisp_Object handler;
789
  int safe_p = 1;
790
  char *fmode = "r";
791
  Lisp_Object tmp[2];
792
#ifdef DOS_NT
793
  fmode = "rt";
794
#endif /* DOS_NT */
Jim Blandy's avatar
Jim Blandy committed
795

796
  CHECK_STRING (file);
Jim Blandy's avatar
Jim Blandy committed
797

798
  /* If file name is magic, call the handler.  */
799 800 801 802
  /* This shouldn't be necessary any more now that `openp' handles it right.
    handler = Ffind_file_name_handler (file, Qload);
    if (!NILP (handler))
      return call5 (handler, Qload, file, noerror, nomessage, nosuffix); */
803

804 805
  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
806 807
     (Below here, we care only whether they are nil or not.)
     The presence of this call is the result of a historical accident:
808
     it used to be in every file-operation and when it got removed
809 810 811
     everywhere, it accidentally stayed here.  Since then, enough people
     supposedly have things like (load "$PROJECT/foo.el") in their .emacs
     that it seemed risky to remove.  */
812 813 814 815 816 817 818 819 820
  if (! NILP (noerror))
    {
      file = internal_condition_case_1 (Fsubstitute_in_file_name, file,
					Qt, load_error_handler);
      if (NILP (file))
	return Qnil;
    }
  else
    file = Fsubstitute_in_file_name (file);
821

822

Jim Blandy's avatar
Jim Blandy committed
823 824
  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
825
  if (SCHARS (file) > 0)
Jim Blandy's avatar
Jim Blandy committed
826
    {
827
      int size = SBYTES (file);
828

829 830
      found = Qnil;
      GCPRO2 (file, found);
831 832 833 834 835

      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
836
	      && !strcmp (SDATA (file) + size - 3, ".el"))
837 838
	    must_suffix = Qnil;
	  else if (size > 4
839
		   && !strcmp (SDATA (file) + size - 4, ".elc"))
840 841 842 843 844 845 846
	    must_suffix = Qnil;
	  /* Don't insist on adding a suffix
	     if the argument includes a directory name.  */
	  else if (! NILP (Ffile_name_directory (file)))
	    must_suffix = Qnil;
	}

847
      fd = openp (Vload_path, file,
848
		  (!NILP (nosuffix) ? Qnil
849 850 851
		   : !NILP (must_suffix) ? Fget_load_suffixes ()
		   : Fappend (2, (tmp[0] = Fget_load_suffixes (),
				  tmp[1] = Vload_file_rep_suffixes,
852
				  tmp))),
853
		  &found, Qnil);
854
      UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
855 856
    }

857
  if (fd == -1)
Jim Blandy's avatar
Jim Blandy committed
858
    {
Jim Blandy's avatar
Jim Blandy committed
859
      if (NILP (noerror))
860 861
	xsignal2 (Qfile_error, build_string ("Cannot open load file"), file);
      return Qnil;
Jim Blandy's avatar
Jim Blandy committed
862 863
    }

864
  /* Tell startup.el whether or not we found the user's init file.  */
Karl Heuer's avatar
Karl Heuer committed
865 866 867
  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

868 869
  /* If FD is -2, that means openp found a magic file.  */
  if (fd == -2)
870
    {
871 872 873 874 875 876 877 878 879
      if (NILP (Fequal (found, file)))
	/* If FOUND is a different file name from FILE,
	   find its handler even if we have already inhibited
	   the `load' operation on FILE.  */
	handler = Ffind_file_name_handler (found, Qt);
      else
	handler = Ffind_file_name_handler (found, Qload);
      if (! NILP (handler))
	return call5 (handler, Qload, found, noerror, nomessage, Qt);
880 881
    }

882 883 884 885 886 887 888 889 890 891
  /* Check if we're stuck in a recursive load cycle.

     2000-09-21: It's not possible to just check for the file loaded
     being a member of Vloads_in_progress.  This fails because of the
     way the byte compiler currently works; `provide's are not
     evaluted, see font-lock.el/jit-lock.el as an example.  This
     leads to a certain amount of ``normal'' recursion.

     Also, just loading a file recursively is not always an error in
     the general case; the second load may do something different.  */
892 893 894 895 896 897 898
  {
    int count = 0;
    Lisp_Object tem;
    for (tem = Vloads_in_progress; CONSP (tem); tem = XCDR (tem))
      if (!NILP (Fequal (found, XCAR (tem))))
	count++;
    if (count > 3)
899 900 901
      {
	if (fd >= 0)
	  emacs_close (fd);
902
	signal_error ("Recursive load", Fcons (found, Vloads_in_progress));
903
      }
904 905 906
    record_unwind_protect (record_load_unwind, Vloads_in_progress);
    Vloads_in_progress = Fcons (found, Vloads_in_progress);
  }
907

908 909 910 911 912 913 914
  /* Get the name for load-history. */
  hist_file_name = (! NILP (Vpurify_flag)
                    ? Fconcat (2, (tmp[0] = Ffile_name_directory (file),
                                   tmp[1] = Ffile_name_nondirectory (found),
                                   tmp))
                    : found) ;

915
  /* Check for the presence of old-style quotes and warn about them.  */
916 917 918
  specbind (Qold_style_backquotes, Qnil);
  record_unwind_protect (load_warn_old_style_backquotes, file);

919
  if (!bcmp (SDATA (found) + SBYTES (found) - 4,
920 921 922
	     ".elc", 4))
    /* Load .elc files directly, but not when they are
       remote and have no handler!  */
Jim Blandy's avatar
Jim Blandy committed
923
    {
924
      if (fd != -2)
925
	{
926 927
	  struct stat s1, s2;
	  int result;
928

929
	  GCPRO3 (file, found, hist_file_name);
930

931 932 933 934
	  if (!safe_to_load_p (fd))
	    {
	      safe_p = 0;
	      if (!load_dangerous_libraries)
935 936 937 938 939 940
		{
		  if (fd >= 0)
		    emacs_close (fd);
		  error ("File `%s' was not compiled in Emacs",
			 SDATA (found));
		}
941 942 943
	      else if (!NILP (nomessage))
		message_with_string ("File `%s' not compiled in Emacs", found, 1);
	    }
944

945 946
	  compiled = 1;

947 948
	  efound = ENCODE_FILE (found);

Dave Love's avatar
Dave Love committed
949
#ifdef DOS_NT
950
	  fmode = "rb";
Dave Love's avatar
Dave Love committed
951
#endif /* DOS_NT */
952
	  stat ((char *)SDATA (efound), &s1);
953
	  SSET (efound, SBYTES (efound) - 1, 0);
954
	  result = stat ((char *)SDATA (efound), &s2);
955
	  SSET (efound, SBYTES (efound) - 1, 'c');
956

957 958 959 960
	  if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
	    {
	      /* Make the progress messages mention that source is newer.  */
	      newer = 1;
961

962
	      /* If we won't print another message, mention this anyway.  */
963 964
	      if (!NILP (nomessage))
		{
965 966
		  Lisp_Object msg_file;
		  msg_file = Fsubstring (found, make_number (0), make_number (-1));
967
		  message_with_string ("Source file `%s' newer than byte-compiled file",
968
				       msg_file, 1);
969
		}
970
	    }
971
	  UNGCPRO;
972
	}
Jim Blandy's avatar
Jim Blandy committed
973
    }
Karl Heuer's avatar
Karl Heuer committed
974 975 976 977 978
  else
    {
      /* We are loading a source file (*.el).  */
      if (!NILP (Vload_source_file_function))
	{
979
	  Lisp_Object val;
980 981

	  if (fd >= 0)
982
	    emacs_close (fd);
983
	  val = call4 (Vload_source_file_function, found, hist_file_name,
984 985 986
		       NILP (noerror) ? Qnil : Qt,
		       NILP (nomessage) ? Qnil : Qt);
	  return unbind_to (count, val);
Karl Heuer's avatar
Karl Heuer committed
987 988
	}
    }
Jim Blandy's avatar
Jim Blandy committed
989

990
  GCPRO3 (file, found, hist_file_name);
991

992
#ifdef WINDOWSNT
993
  emacs_close (fd);