lread.c 117 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>
Jim Blandy's avatar
Jim Blandy committed
30
#include "lisp.h"
31
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
32
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
33
#include "charset.h"
34
#include <epaths.h>
Jim Blandy's avatar
Jim Blandy committed
35
#include "commands.h"
Jim Blandy's avatar
Jim Blandy committed
36
#include "keyboard.h"
37
#include "termhooks.h"
38
#include "coding.h"
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
39
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
40 41 42 43 44

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

45 46 47 48 49 50 51
#ifdef MSDOS
#if __DJGPP__ < 2
#include <unistd.h>	/* to get X_OK */
#endif
#include "msdos.h"
#endif

Andreas Schwab's avatar
Andreas Schwab committed
52 53 54 55
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
56 57 58 59 60 61
#ifndef X_OK
#define X_OK 01
#endif

#include <math.h>

Richard M. Stallman's avatar
Richard M. Stallman committed
62 63 64 65
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Dave Love's avatar
Dave Love committed
66 67 68
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
Richard M. Stallman's avatar
Richard M. Stallman committed
69 70 71 72
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

73
#ifdef HAVE_FSEEKO
74 75 76 77 78 79 80
#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

81
#ifndef USE_CRT_DLL
82
extern int errno;
83
#endif
84

85
Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
Jim Blandy's avatar
Jim Blandy committed
86
Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
87
Lisp_Object Qascii_character, Qload, Qload_file_name;
88
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
89
Lisp_Object Qinhibit_file_name_operation;
90
Lisp_Object Qeval_buffer_list, Veval_buffer_list;
91
Lisp_Object Qfile_truename, Qdo_after_load_evaluation; /* ACM 2006/5/16 */
92 93

extern Lisp_Object Qevent_symbol_element_mask;
94
extern Lisp_Object Qfile_exists_p;
Jim Blandy's avatar
Jim Blandy committed
95

Lute Kamstra's avatar
Lute Kamstra committed
96
/* non-zero iff inside `load' */
Jim Blandy's avatar
Jim Blandy committed
97 98
int load_in_progress;

99 100 101
/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

102
/* Search path and suffixes for files to be loaded. */
103
Lisp_Object Vload_path, Vload_suffixes, Vload_file_rep_suffixes;
Jim Blandy's avatar
Jim Blandy committed
104

Karl Heuer's avatar
Karl Heuer committed
105 106 107
/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

108 109 110 111
/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

112
/* This is used to build the load history. */
113 114
Lisp_Object Vcurrent_load_list;

115 116 117
/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

118 119 120
/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

121 122 123
/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

124 125 126 127 128 129
/* 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;

130 131 132
/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

133 134 135
/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

136
/* Function to use for loading an Emacs Lisp source file (not
Karl Heuer's avatar
Karl Heuer committed
137 138 139
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

140 141 142
/* List of all DEFVAR_BOOL variables.  Used by the byte optimizer.  */
Lisp_Object Vbyte_boolean_vars;

143 144 145 146 147 148 149
/* 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;

150 151 152
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

153
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
154 155 156 157 158
static FILE *instream;

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

159
/* For use within read-from-string (this reader is non-reentrant!!)  */
Jim Blandy's avatar
Jim Blandy committed
160
static int read_from_string_index;
161
static int read_from_string_index_byte;
Jim Blandy's avatar
Jim Blandy committed
162
static int read_from_string_limit;
163

164 165 166
/* Number of bytes left to read in the buffer character
   that `readchar' has already advanced over.  */
static int readchar_backlog;
167 168 169
/* Number of characters read in the current call to Fread or
   Fread_from_string. */
static int readchar_count;
170

171
/* This contains the last string skipped with #@.  */
172 173 174 175 176 177
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.  */
178
static file_offset saved_doc_string_position;
179

180 181 182 183 184 185 186 187 188
/* 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.  */
189
static file_offset prev_saved_doc_string_position;
190

191 192 193 194 195
/* 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;
196 197 198 199

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

Lute Kamstra's avatar
Lute Kamstra committed
200
static Lisp_Object Vloads_in_progress;
201

202 203 204 205 206 207 208 209
/* 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
210
static void to_multibyte P_ ((char **, char **, int *));
211
static void readevalloop P_ ((Lisp_Object, FILE*, Lisp_Object,
212
			      Lisp_Object (*) (), int,
213
			      Lisp_Object, Lisp_Object,
214 215 216 217
			      Lisp_Object, Lisp_Object));
static Lisp_Object load_unwind P_ ((Lisp_Object));
static Lisp_Object load_descriptor_unwind P_ ((Lisp_Object));

218
static void invalid_syntax P_ ((const char *, int)) NO_RETURN;
219
static void end_of_file_error P_ (()) NO_RETURN;
220

Jim Blandy's avatar
Jim Blandy committed
221 222 223

/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
224 225
   UNREAD(c) to unread c to be read again.

226 227 228
   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.
229

230 231 232 233
   [ 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
234
 */
Jim Blandy's avatar
Jim Blandy committed
235 236 237 238 239 240 241 242 243

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

static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
244
  register int c;
Jim Blandy's avatar
Jim Blandy committed
245

246
  readchar_count++;
247

248
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
249
    {
250
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
251

252 253
      int pt_byte = BUF_PT_BYTE (inbuffer);
      int orig_pt_byte = pt_byte;
254

255 256 257 258 259 260 261 262
      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);

263 264
      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
Jim Blandy's avatar
Jim Blandy committed
265

266 267
      readchar_backlog = -1;

268 269
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
270
	  /* Fetch the character code from the buffer.  */
271 272 273 274 275 276 277 278
	  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++;
279
	}
280
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
281

282
      return c;
Jim Blandy's avatar
Jim Blandy committed
283
    }
284
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
285
    {
286
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
287

288 289
      int bytepos = marker_byte_position (readcharfun);
      int orig_bytepos = bytepos;
290

291 292 293 294 295 296 297 298
      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);

299 300
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
301

302 303
      readchar_backlog = -1;

304 305
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
306
	  /* Fetch the character code from the buffer.  */
307 308 309 310 311 312 313 314
	  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++;
315 316
	}

317 318 319 320
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
321
    }
322 323 324 325

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

Jim Blandy's avatar
Jim Blandy committed
326
  if (EQ (readcharfun, Qget_file_char))
327
    {
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
328
      BLOCK_INPUT;
329 330 331 332 333
      c = getc (instream);
#ifdef EINTR
      /* Interrupted reads have been observed while reading over the network */
      while (c == EOF && ferror (instream) && errno == EINTR)
	{
334
	  UNBLOCK_INPUT;
335
	  QUIT;
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
336
	  BLOCK_INPUT;
337
	  clearerr (instream);
338 339 340
	  c = getc (instream);
	}
#endif
341
      UNBLOCK_INPUT;
342 343
      return c;
    }
Jim Blandy's avatar
Jim Blandy committed
344

345
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
346
    {
347
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
348
	c = -1;
349
      else
350 351 352
	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
353

Jim Blandy's avatar
Jim Blandy committed
354 355 356 357 358
      return c;
    }

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
359
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
360 361 362 363 364 365 366 367 368 369 370 371
    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;
{
372
  readchar_count--;
373 374 375 376
  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.  */
    ;
377
  else if (BUFFERP (readcharfun))
378
    {
379 380
      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
381

382 383
      if (readchar_backlog >= 0)
	readchar_backlog++;
384
      else
385 386 387 388 389 390
	{
	  BUF_PT (b)--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
391

392 393
	  BUF_PT_BYTE (b) = bytepos;
	}
394
    }
395
  else if (MARKERP (readcharfun))
396
    {
397 398
      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
399

400 401
      if (readchar_backlog >= 0)
	readchar_backlog++;
402
      else
403 404 405 406 407 408
	{
	  XMARKER (readcharfun)->charpos--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
409

410 411
	  XMARKER (readcharfun)->bytepos = bytepos;
	}
412
    }
413
  else if (STRINGP (readcharfun))
414 415 416 417 418
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
419 420
  else if (EQ (readcharfun, Qlambda))
    read_bytecode_char (1);
Jim Blandy's avatar
Jim Blandy committed
421
  else if (EQ (readcharfun, Qget_file_char))
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
422 423 424 425 426
    {
      BLOCK_INPUT;
      ungetc (c, instream);
      UNBLOCK_INPUT;
    }
Jim Blandy's avatar
Jim Blandy committed
427 428 429 430
  else
    call1 (readcharfun, make_number (c));
}

431 432 433
static Lisp_Object read_internal_start P_ ((Lisp_Object, Lisp_Object,
					    Lisp_Object));
static Lisp_Object read0 P_ ((Lisp_Object));
434
static Lisp_Object read1 P_ ((Lisp_Object, int *, int));
435 436 437 438 439 440 441 442 443 444

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));
445

Jim Blandy's avatar
Jim Blandy committed
446

447
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
448

449 450
extern Lisp_Object read_char ();

451 452 453 454 455 456 457 458 459 460 461 462 463
/* 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
464 465 466
   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
467 468 469 470
   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.  */
471

472
Lisp_Object
473
read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
474
		     input_method, seconds)
475
     int no_switch_frame, ascii_required, error_nonascii, input_method;
476
     Lisp_Object seconds;
477
{
478
  Lisp_Object val, delayed_switch_frame;
479
  EMACS_TIME end_time;
480

481
#ifdef HAVE_WINDOW_SYSTEM
482 483
  if (display_hourglass_p)
    cancel_hourglass ();
484
#endif
485

486
  delayed_switch_frame = Qnil;
487

488 489 490 491 492
  /* Compute timeout.  */
  if (NUMBERP (seconds))
    {
      EMACS_TIME wait_time;
      int sec, usec;
493
      double duration = extract_float (seconds);
494 495 496 497 498 499 500 501

      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);
    }

502 503
  /* Read until we get an acceptable event.  */
 retry:
504 505
  val = read_char (0, 0, 0, (input_method ? Qnil : Qt), 0,
		   NUMBERP (seconds) ? &end_time : NULL);
506

507
  if (BUFFERP (val))
508 509
    goto retry;

510
  /* switch-frame events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
511
     character.  This is better than signaling an error just because
512 513 514 515 516
     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)
517
      && EQ (EVENT_HEAD_KIND (EVENT_HEAD (val)), Qswitch_frame))
518 519 520 521 522
    {
      delayed_switch_frame = val;
      goto retry;
    }

523
  if (ascii_required && !(NUMBERP (seconds) && NILP (val)))
524 525
    {
      /* Convert certain symbols to their ASCII equivalents.  */
526
      if (SYMBOLP (val))
527
	{
528
	  Lisp_Object tem, tem1;
529 530 531 532 533 534 535
	  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))
536
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
537 538
	    }
	}
539

540
      /* If we don't have a character now, deal with it appropriately.  */
541
      if (!INTEGERP (val))
542 543 544
	{
	  if (error_nonascii)
	    {
545
	      Vunread_command_events = Fcons (val, Qnil);
546 547 548 549 550 551 552 553 554 555
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

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

556 557
#if 0

558
#ifdef HAVE_WINDOW_SYSTEM
559 560
  if (display_hourglass_p)
    start_hourglass ();
561
#endif
562 563 564

#endif

565 566 567
  return val;
}

568
DEFUN ("read-char", Fread_char, Sread_char, 0, 3, 0,
569 570 571 572 573 574 575 576 577 578 579 580
       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
581 582 583 584 585 586 587
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
588
{
589 590
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
591
  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
592 593
}

594
DEFUN ("read-event", Fread_event, Sread_event, 0, 3, 0,
595 596 597 598
       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
599 600 601 602 603 604 605
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
606
{
607 608
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
609
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
610 611
}

612
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 3, 0,
613 614 615 616 617 618
       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
619 620 621 622 623 624 625
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
626
{
627 628
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
629
  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
630 631 632
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
633 634
       doc: /* Don't use this yourself.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
635 636
{
  register Lisp_Object val;
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
637
  BLOCK_INPUT;
638
  XSETINT (val, getc (instream));
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
639
  UNBLOCK_INPUT;
Jim Blandy's avatar
Jim Blandy committed
640 641
  return val;
}
642 643


644

645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681
/* Value is non-zero if the file asswociated with file descriptor FD
   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;
}


682 683 684 685 686 687 688 689 690 691
/* 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;
}

692 693 694 695 696 697 698 699
/* This handler function is used via internal_condition_case_1.  */

static Lisp_Object
load_error_handler (data)
     Lisp_Object data;
{
  return Qnil;
}
700

701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722
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);
}

723
DEFUN ("load", Fload, Sload, 1, 5, 0,
724 725
       doc: /* Execute a file of Lisp code named FILE.
First try FILE with `.elc' appended, then try with `.el',
726 727 728
then try FILE unmodified (the exact suffixes in the exact order are
determined by  `load-suffixes').  Environment variable references in
FILE are replaced with their values by calling `substitute-in-file-name'.
729
This function searches the directories in `load-path'.
730

731
If optional second arg NOERROR is non-nil,
732
report no error if FILE doesn't exist.
733
Print messages at start and end of loading unless
734
optional third arg NOMESSAGE is non-nil.
735
If optional fourth arg NOSUFFIX is non-nil, don't try adding
736
suffixes `.elc' or `.el' to the specified name FILE.
737
If optional fifth arg MUST-SUFFIX is non-nil, insist on
738 739 740 741 742 743 744 745 746 747 748 749 750 751 752
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.
753 754 755 756 757

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'.

758
Return t if the file exists and loads successfully.  */)
759
     (file, noerror, nomessage, nosuffix, must_suffix)
760
     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
Jim Blandy's avatar
Jim Blandy committed
761 762 763
{
  register FILE *stream;
  register int fd = -1;
Juanma Barranquero's avatar
Juanma Barranquero committed
764
  int count = SPECPDL_INDEX ();
Jim Blandy's avatar
Jim Blandy committed
765
  Lisp_Object temp;
766 767
  struct gcpro gcpro1, gcpro2, gcpro3;
  Lisp_Object found, efound, hist_file_name;
768 769 770 771
  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
772
  Lisp_Object handler;
773
  int safe_p = 1;
774
  char *fmode = "r";
775
  Lisp_Object tmp[2];
776
#ifdef DOS_NT
777
  fmode = "rt";
778
#endif /* DOS_NT */
Jim Blandy's avatar
Jim Blandy committed
779

780
  CHECK_STRING (file);
Jim Blandy's avatar
Jim Blandy committed
781

782
  /* If file name is magic, call the handler.  */
783 784 785 786
  /* 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); */
787

788 789
  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
790 791
     (Below here, we care only whether they are nil or not.)
     The presence of this call is the result of a historical accident:
792
     it used to be in every file-operation and when it got removed
793 794 795
     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.  */
796 797 798 799 800 801 802 803 804
  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);
805

806

Jim Blandy's avatar
Jim Blandy committed
807 808
  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
809
  if (SCHARS (file) > 0)
Jim Blandy's avatar
Jim Blandy committed
810
    {
811
      int size = SBYTES (file);
812

813 814
      found = Qnil;
      GCPRO2 (file, found);
815 816 817 818 819

      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
820
	      && !strcmp (SDATA (file) + size - 3, ".el"))
821 822
	    must_suffix = Qnil;
	  else if (size > 4
823
		   && !strcmp (SDATA (file) + size - 4, ".elc"))
824 825 826 827 828 829 830
	    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;
	}

831
      fd = openp (Vload_path, file,
832
		  (!NILP (nosuffix) ? Qnil
833 834 835
		   : !NILP (must_suffix) ? Fget_load_suffixes ()
		   : Fappend (2, (tmp[0] = Fget_load_suffixes (),
				  tmp[1] = Vload_file_rep_suffixes,
836
				  tmp))),
837
		  &found, Qnil);
838
      UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
839 840
    }

841
  if (fd == -1)
Jim Blandy's avatar
Jim Blandy committed
842
    {
Jim Blandy's avatar
Jim Blandy committed
843
      if (NILP (noerror))
844 845
	xsignal2 (Qfile_error, build_string ("Cannot open load file"), file);
      return Qnil;
Jim Blandy's avatar
Jim Blandy committed
846 847
    }

848
  /* Tell startup.el whether or not we found the user's init file.  */
Karl Heuer's avatar
Karl Heuer committed
849 850 851
  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

852 853
  /* If FD is -2, that means openp found a magic file.  */
  if (fd == -2)
854
    {
855 856 857 858 859 860 861 862 863
      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);
864 865
    }

866 867 868 869 870 871 872 873 874 875
  /* 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.  */
876 877 878 879 880 881 882
  {
    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)
883 884 885
      {
	if (fd >= 0)
	  emacs_close (fd);
886
	signal_error ("Recursive load", Fcons (found, Vloads_in_progress));
887
      }
888 889 890
    record_unwind_protect (record_load_unwind, Vloads_in_progress);
    Vloads_in_progress = Fcons (found, Vloads_in_progress);
  }
891

892 893 894 895 896 897 898
  /* 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) ;

899
  if (!bcmp (SDATA (found) + SBYTES (found) - 4,
900 901 902
	     ".elc", 4))
    /* Load .elc files directly, but not when they are
       remote and have no handler!  */
Jim Blandy's avatar
Jim Blandy committed
903
    {
904
      if (fd != -2)
905
	{
906 907
	  struct stat s1, s2;
	  int result;
908

909
	  GCPRO3 (file, found, hist_file_name);
910

911 912 913 914
	  if (!safe_to_load_p (fd))
	    {
	      safe_p = 0;
	      if (!load_dangerous_libraries)
915 916 917 918 919 920
		{
		  if (fd >= 0)
		    emacs_close (fd);
		  error ("File `%s' was not compiled in Emacs",
			 SDATA (found));
		}
921 922 923
	      else if (!NILP (nomessage))
		message_with_string ("File `%s' not compiled in Emacs", found, 1);
	    }
924

925 926
	  compiled = 1;

927 928
	  efound = ENCODE_FILE (found);

Dave Love's avatar
Dave Love committed
929
#ifdef DOS_NT
930
	  fmode = "rb";
Dave Love's avatar
Dave Love committed
931
#endif /* DOS_NT */
932
	  stat ((char *)SDATA (efound), &s1);
933
	  SSET (efound, SBYTES (efound) - 1, 0);
934
	  result = stat ((char *)SDATA (efound), &s2);
935
	  SSET (efound, SBYTES (efound) - 1, 'c');
936

937 938 939 940
	  if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
	    {
	      /* Make the progress messages mention that source is newer.  */
	      newer = 1;
941

942
	      /* If we won't print another message, mention this anyway.  */
943 944
	      if (!NILP (nomessage))
		{
945 946
		  Lisp_Object msg_file;
		  msg_file = Fsubstring (found, make_number (0), make_number (-1));
947
		  message_with_string ("Source file `%s' newer than byte-compiled file",
948
				       msg_file, 1);
949
		}
950
	    }
951
	  UNGCPRO;
952
	}
Jim Blandy's avatar
Jim Blandy committed
953
    }
Karl Heuer's avatar
Karl Heuer committed
954 955 956 957 958
  else
    {
      /* We are loading a source file (*.el).  */
      if (!NILP (Vload_source_file_function))
	{
959
	  Lisp_Object val;
960 961

	  if (fd >= 0)
962
	    emacs_close (fd);
963
	  val = call4 (Vload_source_file_function, found, hist_file_name,
964 965 966
		       NILP (noerror) ? Qnil : Qt,
		       NILP (nomessage) ? Qnil : Qt);
	  return unbind_to (count, val);
Karl Heuer's avatar
Karl Heuer committed
967 968
	}
    }
Jim Blandy's avatar
Jim Blandy committed
969

970
  GCPRO3 (file, found, hist_file_name);
971

972
#ifdef WINDOWSNT
973
  emacs_close (fd);
974
  efound = ENCODE_FILE (found);
975
  stream = fopen ((char *) SDATA (efound), fmode);
976 977 978
#else  /* not WINDOWSNT */
  stream = fdopen (fd, fmode);
#endif /* not WINDOWSNT */
Jim Blandy's avatar
Jim Blandy committed
979 980
  if (stream == 0)
    {
981
      emacs_close (fd);
982
      error ("Failure to create stdio stream for %s", SDATA (file));
Jim Blandy's avatar
Jim Blandy committed
983 984
    }

985 986 987
  if (! NILP (Vpurify_flag))
    Vpreloaded_file_list = Fcons (file, Vpreloaded_file_list);

988 989
  if (NILP (nomessage))
    {
990 991 992 993
      if (!safe_p)
	message_with_string ("Loading %s (compiled; note unsafe, not compiled in Emacs)...",
		 file, 1);
      else if (!compiled)
994
	message_with_string ("Loading %s (source)...", file, 1);
995
      else if (newer)