lread.c 119 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"
Kenichi Handa's avatar
Kenichi Handa committed
34
#include "character.h"
Karl Heuer's avatar
Karl Heuer committed
35
#include "charset.h"
Kenichi Handa's avatar
Kenichi Handa committed
36
#include "coding.h"
37
#include <epaths.h>
Jim Blandy's avatar
Jim Blandy committed
38
#include "commands.h"
Jim Blandy's avatar
Jim Blandy committed
39
#include "keyboard.h"
40
#include "frame.h"
41
#include "termhooks.h"
42
#include "coding.h"
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
43
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
44 45 46 47 48

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

49 50 51 52 53 54 55
#ifdef MSDOS
#if __DJGPP__ < 2
#include <unistd.h>	/* to get X_OK */
#endif
#include "msdos.h"
#endif

Andreas Schwab's avatar
Andreas Schwab committed
56 57 58 59
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
60 61 62 63 64 65
#ifndef X_OK
#define X_OK 01
#endif

#include <math.h>

Richard M. Stallman's avatar
Richard M. Stallman committed
66 67 68 69
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Dave Love's avatar
Dave Love committed
70 71 72
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
Richard M. Stallman's avatar
Richard M. Stallman committed
73 74 75 76
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

77
#ifdef HAVE_FSEEKO
78 79 80 81 82 83 84
#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

85
#ifndef USE_CRT_DLL
86
extern int errno;
87
#endif
88

89
Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
Jim Blandy's avatar
Jim Blandy committed
90
Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
91
Lisp_Object Qascii_character, Qload, Qload_file_name;
92
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
93
Lisp_Object Qinhibit_file_name_operation;
94
Lisp_Object Qeval_buffer_list, Veval_buffer_list;
95
Lisp_Object Qfile_truename, Qdo_after_load_evaluation; /* ACM 2006/5/16 */
96

Kenichi Handa's avatar
Kenichi Handa committed
97 98 99 100 101 102
/* Used instead of Qget_file_char while loading *.elc files compiled
   by Emacs 21 or older.  */
static Lisp_Object Qget_emacs_mule_file_char;

static Lisp_Object Qload_force_doc_strings;

103
extern Lisp_Object Qevent_symbol_element_mask;
104
extern Lisp_Object Qfile_exists_p;
Jim Blandy's avatar
Jim Blandy committed
105

Glenn Morris's avatar
Glenn Morris committed
106
/* non-zero if inside `load' */
Jim Blandy's avatar
Jim Blandy committed
107 108
int load_in_progress;

109 110 111
/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

112
/* Search path and suffixes for files to be loaded. */
113
Lisp_Object Vload_path, Vload_suffixes, Vload_file_rep_suffixes;
Jim Blandy's avatar
Jim Blandy committed
114

Karl Heuer's avatar
Karl Heuer committed
115 116 117
/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

118 119 120 121
/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

122
/* This is used to build the load history. */
123 124
Lisp_Object Vcurrent_load_list;

125 126 127
/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

128 129 130
/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

131 132 133
/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

134 135 136 137 138 139
/* 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;

140 141 142
/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

143 144 145
/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

Kenichi Handa's avatar
Kenichi Handa committed
146 147 148 149 150
/* Nonzero means READCHAR should read bytes one by one (not character)
   when READCHARFUN is Qget_file_char or Qget_emacs_mule_file_char.
   This is set to 1 by read1 temporarily while handling #@NUMBER.  */
static int load_each_byte;

151
/* Function to use for loading an Emacs Lisp source file (not
Karl Heuer's avatar
Karl Heuer committed
152 153 154
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

155 156 157
/* List of all DEFVAR_BOOL variables.  Used by the byte optimizer.  */
Lisp_Object Vbyte_boolean_vars;

158 159 160 161 162 163 164
/* 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;

165 166 167
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

168
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
169 170 171 172 173
static FILE *instream;

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

174
/* For use within read-from-string (this reader is non-reentrant!!)  */
Jim Blandy's avatar
Jim Blandy committed
175
static int read_from_string_index;
176
static int read_from_string_index_byte;
Jim Blandy's avatar
Jim Blandy committed
177
static int read_from_string_limit;
178

179 180 181
/* Number of characters read in the current call to Fread or
   Fread_from_string. */
static int readchar_count;
182

183
/* This contains the last string skipped with #@.  */
184 185 186 187 188 189
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.  */
190
static file_offset saved_doc_string_position;
191

192 193 194 195 196 197 198 199 200
/* 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.  */
201
static file_offset prev_saved_doc_string_position;
202

203 204 205 206 207
/* 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;
208
static Lisp_Object Vold_style_backquotes, Qold_style_backquotes;
209 210 211 212

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

Lute Kamstra's avatar
Lute Kamstra committed
213
static Lisp_Object Vloads_in_progress;
214

215 216 217 218 219 220 221 222
/* 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;

Kenichi Handa's avatar
Kenichi Handa committed
223 224 225
static int read_emacs_mule_char P_ ((int, int (*) (int, Lisp_Object),
				     Lisp_Object));

226
static void readevalloop P_ ((Lisp_Object, FILE*, Lisp_Object,
227
			      Lisp_Object (*) (), int,
228
			      Lisp_Object, Lisp_Object,
229 230 231 232
			      Lisp_Object, Lisp_Object));
static Lisp_Object load_unwind P_ ((Lisp_Object));
static Lisp_Object load_descriptor_unwind P_ ((Lisp_Object));

233
static void invalid_syntax P_ ((const char *, int)) NO_RETURN;
234
static void end_of_file_error P_ (()) NO_RETURN;
235

Jim Blandy's avatar
Jim Blandy committed
236

Kenichi Handa's avatar
Kenichi Handa committed
237 238 239 240 241 242 243 244 245 246
/* Functions that read one byte from the current source READCHARFUN
   or unreads one byte.  If the integer argument C is -1, it returns
   one read byte, or -1 when there's no more byte in the source.  If C
   is 0 or positive, it unreads C, and the return value is not
   interesting.  */

static int readbyte_for_lambda P_ ((int, Lisp_Object));
static int readbyte_from_file P_ ((int, Lisp_Object));
static int readbyte_from_string P_ ((int, Lisp_Object));

Jim Blandy's avatar
Jim Blandy committed
247 248
/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
249 250
   UNREAD(c) to unread c to be read again.

Kenichi Handa's avatar
Kenichi Handa committed
251
   These macros correctly read/unread multibyte characters.  */
Jim Blandy's avatar
Jim Blandy committed
252 253 254 255

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

Kenichi Handa's avatar
Kenichi Handa committed
256
/* When READCHARFUN is Qget_file_char, Qget_emacs_mule_file_char,
Kenichi Handa's avatar
Kenichi Handa committed
257 258
   Qlambda, or a cons, we use this to keep an unread character because
   a file stream can't handle multibyte-char unreading.  The value -1
Kenichi Handa's avatar
Kenichi Handa committed
259 260 261
   means that there's no unread character. */
static int unread_char;

Jim Blandy's avatar
Jim Blandy committed
262 263 264 265 266
static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
267
  register int c;
Kenichi Handa's avatar
Kenichi Handa committed
268 269 270 271
  int (*readbyte) P_ ((int, Lisp_Object));
  unsigned char buf[MAX_MULTIBYTE_LENGTH];
  int i, len;
  int emacs_mule_encoding = 0;
Jim Blandy's avatar
Jim Blandy committed
272

273
  readchar_count++;
274

275
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
276
    {
277
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
278

279
      int pt_byte = BUF_PT_BYTE (inbuffer);
280

281 282
      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
Jim Blandy's avatar
Jim Blandy committed
283

284 285
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
286
	  /* Fetch the character code from the buffer.  */
287 288 289 290 291 292 293
	  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);
Kenichi Handa's avatar
Kenichi Handa committed
294 295
	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
296
	  pt_byte++;
297
	}
298
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
299

300
      return c;
Jim Blandy's avatar
Jim Blandy committed
301
    }
302
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
303
    {
304
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
305

306
      int bytepos = marker_byte_position (readcharfun);
307

308 309
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
310

311 312
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
313
	  /* Fetch the character code from the buffer.  */
314 315 316 317 318 319 320
	  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);
Kenichi Handa's avatar
Kenichi Handa committed
321 322
	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
323
	  bytepos++;
324 325
	}

326 327 328 329
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
330
    }
331 332

  if (EQ (readcharfun, Qlambda))
Kenichi Handa's avatar
Kenichi Handa committed
333 334 335 336
    {
      readbyte = readbyte_for_lambda;
      goto read_multibyte;
    }
337

Jim Blandy's avatar
Jim Blandy committed
338
  if (EQ (readcharfun, Qget_file_char))
339
    {
Kenichi Handa's avatar
Kenichi Handa committed
340 341
      readbyte = readbyte_from_file;
      goto read_multibyte;
342
    }
Jim Blandy's avatar
Jim Blandy committed
343

344
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
345
    {
346
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
347
	c = -1;
348
      else
349 350 351
	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
352

Jim Blandy's avatar
Jim Blandy committed
353 354 355
      return c;
    }

Kenichi Handa's avatar
Kenichi Handa committed
356 357 358 359 360 361 362 363 364 365 366 367
  if (CONSP (readcharfun))
    {
      /* This is the case that read_vector is reading from a unibyte
	 string that contains a byte sequence previously skipped
	 because of #@NUMBER.  The car part of readcharfun is that
	 string, and the cdr part is a value of readcharfun given to
	 read_vector.  */
      readbyte = readbyte_from_string;
      if (EQ (XCDR (readcharfun), Qget_emacs_mule_file_char))
	emacs_mule_encoding = 1;
      goto read_multibyte;
    }
Kenichi Handa's avatar
Kenichi Handa committed
368

Kenichi Handa's avatar
Kenichi Handa committed
369 370 371 372 373 374
  if (EQ (readcharfun, Qget_emacs_mule_file_char))
    {
      readbyte = readbyte_from_file;
      emacs_mule_encoding = 1;
      goto read_multibyte;
    }
Jim Blandy's avatar
Jim Blandy committed
375 376 377

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
378
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
379 380
    return -1;
  return XINT (tem);
Kenichi Handa's avatar
Kenichi Handa committed
381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408

 read_multibyte:
  if (unread_char >= 0)
    {
      c = unread_char;
      unread_char = -1;
      return c;
    }
  c = (*readbyte) (-1, readcharfun);
  if (c < 0 || ASCII_BYTE_P (c) || load_each_byte)
    return c;
  if (emacs_mule_encoding)
    return read_emacs_mule_char (c, readbyte, readcharfun);
  i = 0;
  buf[i++] = c;
  len = BYTES_BY_CHAR_HEAD (c);
  while (i < len)
    {
      c = (*readbyte) (-1, readcharfun);
      if (c < 0 || ! TRAILING_CODE_P (c))
	{
	  while (--i > 1)
	    (*readbyte) (buf[i], readcharfun);
	  return BYTE8_TO_CHAR (buf[0]);
	}
      buf[i++] = c;
    }
  return STRING_CHAR (buf, i);
Jim Blandy's avatar
Jim Blandy committed
409 410 411 412 413 414 415 416 417 418
}

/* 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;
{
419
  readchar_count--;
420 421 422 423
  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.  */
    ;
424
  else if (BUFFERP (readcharfun))
425
    {
426 427
      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
428

Kenichi Handa's avatar
Kenichi Handa committed
429 430 431
      BUF_PT (b)--;
      if (! NILP (b->enable_multibyte_characters))
	BUF_DEC_POS (b, bytepos);
432
      else
Kenichi Handa's avatar
Kenichi Handa committed
433
	bytepos--;
434

Kenichi Handa's avatar
Kenichi Handa committed
435
      BUF_PT_BYTE (b) = bytepos;
436
    }
437
  else if (MARKERP (readcharfun))
438
    {
439 440
      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
441

Kenichi Handa's avatar
Kenichi Handa committed
442 443 444
      XMARKER (readcharfun)->charpos--;
      if (! NILP (b->enable_multibyte_characters))
	BUF_DEC_POS (b, bytepos);
445
      else
Kenichi Handa's avatar
Kenichi Handa committed
446
	bytepos--;
447

Kenichi Handa's avatar
Kenichi Handa committed
448
      XMARKER (readcharfun)->bytepos = bytepos;
449
    }
450
  else if (STRINGP (readcharfun))
451 452 453 454 455
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
Kenichi Handa's avatar
Kenichi Handa committed
456 457 458 459
  else if (CONSP (readcharfun))
    {
      unread_char = c;
    }
460
  else if (EQ (readcharfun, Qlambda))
Kenichi Handa's avatar
Kenichi Handa committed
461 462 463 464 465 466 467
    {
      unread_char = c;
    }
  else if (EQ (readcharfun, Qget_file_char)
	   || EQ (readcharfun, Qget_emacs_mule_file_char))
    {
      if (load_each_byte)
Miles Bader's avatar
Miles Bader committed
468 469 470 471 472
	{
	  BLOCK_INPUT;
	  ungetc (c, instream);
	  UNBLOCK_INPUT;
	}
Kenichi Handa's avatar
Kenichi Handa committed
473 474 475
      else
	unread_char = c;
    }
Jim Blandy's avatar
Jim Blandy committed
476 477 478 479
  else
    call1 (readcharfun, make_number (c));
}

Kenichi Handa's avatar
Kenichi Handa committed
480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495
static int
readbyte_for_lambda (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  return read_bytecode_char (c >= 0);
}


static int
readbyte_from_file (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  if (c >= 0)
    {
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
496
      BLOCK_INPUT;
Kenichi Handa's avatar
Kenichi Handa committed
497
      ungetc (c, instream);
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
498
      UNBLOCK_INPUT;
Kenichi Handa's avatar
Kenichi Handa committed
499 500 501
      return 0;
    }

Miles Bader's avatar
Miles Bader committed
502
  BLOCK_INPUT;
Kenichi Handa's avatar
Kenichi Handa committed
503
  c = getc (instream);
Miles Bader's avatar
Miles Bader committed
504

Kenichi Handa's avatar
Kenichi Handa committed
505
#ifdef EINTR
Miles Bader's avatar
Miles Bader committed
506 507 508
  /* Interrupted reads have been observed while reading over the network */
  while (c == EOF && ferror (instream) && errno == EINTR)
    {
Miles Bader's avatar
Miles Bader committed
509
      UNBLOCK_INPUT;
Miles Bader's avatar
Miles Bader committed
510 511
      QUIT;
      BLOCK_INPUT;
Miles Bader's avatar
Miles Bader committed
512
      clearerr (instream);
Miles Bader's avatar
Miles Bader committed
513
      c = getc (instream);
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
514
    }
Kenichi Handa's avatar
Kenichi Handa committed
515
#endif
Miles Bader's avatar
Miles Bader committed
516

Miles Bader's avatar
Miles Bader committed
517 518
  UNBLOCK_INPUT;

Kenichi Handa's avatar
Kenichi Handa committed
519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534
  return (c == EOF ? -1 : c);
}

static int
readbyte_from_string (c, readcharfun)
     int c;
     Lisp_Object readcharfun;
{
  Lisp_Object string = XCAR (readcharfun);

  if (c >= 0)
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (string, read_from_string_index);
    }
Kenichi Handa's avatar
Kenichi Handa committed
535

Kenichi Handa's avatar
Kenichi Handa committed
536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584
  if (read_from_string_index >= read_from_string_limit)
    c = -1;
  else
    FETCH_STRING_CHAR_ADVANCE (c, string,
			       read_from_string_index,
			       read_from_string_index_byte);
  return c;
}


/* Read one non-ASCII character from INSTREAM.  The character is
   encoded in `emacs-mule' and the first byte is already read in
   C.  */

extern char emacs_mule_bytes[256];

static int
read_emacs_mule_char (c, readbyte, readcharfun)
     int c;
     int (*readbyte) P_ ((int, Lisp_Object));
     Lisp_Object readcharfun;
{
  /* Emacs-mule coding uses at most 4-byte for one character.  */
  unsigned char buf[4];
  int len = emacs_mule_bytes[c];
  struct charset *charset;
  int i;
  unsigned code;

  if (len == 1)
    /* C is not a valid leading-code of `emacs-mule'.  */
    return BYTE8_TO_CHAR (c);

  i = 0;
  buf[i++] = c;
  while (i < len)
    {
      c = (*readbyte) (-1, readcharfun);
      if (c < 0xA0)
	{
	  while (--i > 1)
	    (*readbyte) (buf[i], readcharfun);
	  return BYTE8_TO_CHAR (buf[0]);
	}
      buf[i++] = c;
    }

  if (len == 2)
    {
Dave Love's avatar
Dave Love committed
585
      charset = emacs_mule_charset[buf[0]];
Kenichi Handa's avatar
Kenichi Handa committed
586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604
      code = buf[1] & 0x7F;
    }
  else if (len == 3)
    {
      if (buf[0] == EMACS_MULE_LEADING_CODE_PRIVATE_11
	  || buf[0] == EMACS_MULE_LEADING_CODE_PRIVATE_12)
	{
	  charset = emacs_mule_charset[buf[1]];
	  code = buf[2] & 0x7F;
	}
      else
	{
	  charset = emacs_mule_charset[buf[0]];
	  code = ((buf[1] << 8) | buf[2]) & 0x7F7F;
	}
    }
  else
    {
      charset = emacs_mule_charset[buf[1]];
Kenichi Handa's avatar
Kenichi Handa committed
605
      code = ((buf[2] << 8) | buf[3]) & 0x7F7F;
Kenichi Handa's avatar
Kenichi Handa committed
606 607 608 609 610 611 612 613 614
    }
  c = DECODE_CHAR (charset, code);
  if (c < 0)
    Fsignal (Qinvalid_read_syntax,
	     Fcons (build_string ("invalid multibyte form"), Qnil));
  return c;
}


615 616 617
static Lisp_Object read_internal_start P_ ((Lisp_Object, Lisp_Object,
					    Lisp_Object));
static Lisp_Object read0 P_ ((Lisp_Object));
618
static Lisp_Object read1 P_ ((Lisp_Object, int *, int));
619 620 621 622 623 624 625 626 627

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

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));
628

Jim Blandy's avatar
Jim Blandy committed
629

630
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
631

632 633 634 635 636 637 638 639 640 641 642 643 644
/* 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
645 646 647
   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
648 649 650 651
   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.  */
652

653
Lisp_Object
654
read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
655
		     input_method, seconds)
656
     int no_switch_frame, ascii_required, error_nonascii, input_method;
657
     Lisp_Object seconds;
658
{
659
  Lisp_Object val, delayed_switch_frame;
660
  EMACS_TIME end_time;
661

662
#ifdef HAVE_WINDOW_SYSTEM
663 664
  if (display_hourglass_p)
    cancel_hourglass ();
665
#endif
666

667
  delayed_switch_frame = Qnil;
668

669 670 671 672 673
  /* Compute timeout.  */
  if (NUMBERP (seconds))
    {
      EMACS_TIME wait_time;
      int sec, usec;
674
      double duration = extract_float (seconds);
675 676 677 678 679 680 681 682

      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
683
/* Read until we get an acceptable event.  */
684
 retry:
685
  do
Karoly Lorentey's avatar
Karoly Lorentey committed
686 687
    val = read_char (0, 0, 0, (input_method ? Qnil : Qt), 0,
		     NUMBERP (seconds) ? &end_time : NULL);
688
  while (INTEGERP (val) && XINT (val) == -2); /* wrong_kboard_jmpbuf */
689

690
  if (BUFFERP (val))
691 692
    goto retry;

693
  /* switch-frame events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
694
     character.  This is better than signaling an error just because
695 696 697 698 699
     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)
700
      && EQ (EVENT_HEAD_KIND (EVENT_HEAD (val)), Qswitch_frame))
701 702 703 704 705
    {
      delayed_switch_frame = val;
      goto retry;
    }

706
  if (ascii_required && !(NUMBERP (seconds) && NILP (val)))
707 708
    {
      /* Convert certain symbols to their ASCII equivalents.  */
709
      if (SYMBOLP (val))
710
	{
711
	  Lisp_Object tem, tem1;
712 713 714 715 716 717 718
	  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))
719
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
720 721
	    }
	}
722

723
      /* If we don't have a character now, deal with it appropriately.  */
724
      if (!INTEGERP (val))
725 726 727
	{
	  if (error_nonascii)
	    {
728
	      Vunread_command_events = Fcons (val, Qnil);
729 730 731 732 733 734 735 736 737 738
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

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

739 740
#if 0

741
#ifdef HAVE_WINDOW_SYSTEM
742 743
  if (display_hourglass_p)
    start_hourglass ();
744
#endif
745 746 747

#endif

748 749 750
  return val;
}

751
DEFUN ("read-char", Fread_char, Sread_char, 0, 3, 0,
752 753 754 755 756 757 758 759 760 761 762 763
       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
764 765 766 767 768 769 770
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
771
{
772 773
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
774
  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
775 776
}

777
DEFUN ("read-event", Fread_event, Sread_event, 0, 3, 0,
778 779 780 781
       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
782 783 784 785 786 787 788
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
789
{
790 791
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
792
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
793 794
}

795
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 3, 0,
796 797 798 799 800 801
       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
802 803 804 805 806 807 808
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
809
{
810 811
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
812
  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
813 814 815
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
816 817
       doc: /* Don't use this yourself.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
818 819
{
  register Lisp_Object val;
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
820
  BLOCK_INPUT;
821
  XSETINT (val, getc (instream));
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
822
  UNBLOCK_INPUT;
Jim Blandy's avatar
Jim Blandy committed
823 824
  return val;
}
825 826


827

Kenichi Handa's avatar
Kenichi Handa committed
828
/* Value is a version number of byte compiled code if the file
Miles Bader's avatar
Miles Bader committed
829
   associated with file descriptor FD is a compiled Lisp file that's
Kenichi Handa's avatar
Kenichi Handa committed
830 831 832
   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.  */
833 834 835 836 837 838 839 840

static int
safe_to_load_p (fd)
     int fd;
{
  char buf[512];
  int nbytes, i;
  int safe_p = 1;
Kenichi Handa's avatar
Kenichi Handa committed
841
  int version = 1;
842 843 844 845 846 847 848 849 850

  /* 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'
Dave Love's avatar
Dave Love committed
851
	 with NUL bytes following it, but note the version.  */
852
      for (i = 0; i < nbytes && buf[i] != '\n'; ++i)
Dave Love's avatar
Dave Love committed
853
	if (i == 4)
Kenichi Handa's avatar
Kenichi Handa committed
854
	  version = buf[i];
855

856 857
      if (i == nbytes
	  || fast_c_string_match_ignore_case (Vbytecomp_version_regexp,
858 859 860
					      buf + i) < 0)
	safe_p = 0;
    }
Dave Love's avatar
Dave Love committed
861 862
  if (safe_p)
    safe_p = version;
863 864 865 866 867 868

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


869 870 871 872 873 874 875 876 877 878
/* 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;
}

879 880 881 882 883 884 885 886
/* This handler function is used via internal_condition_case_1.  */

static Lisp_Object
load_error_handler (data)
     Lisp_Object data;
{
  return Qnil;
}
887

888 889 890 891 892 893
static Lisp_Object
load_warn_old_style_backquotes (file)
     Lisp_Object file;
{
  if (!NILP (Vold_style_backquotes))
    {
894
      Lisp_Object args[2];
895
      args[0] = build_string ("Loading `%s': old-style backquotes detected!");
896 897 898 899 900 901
      args[1] = file;
      Fmessage (2, args);
    }
  return Qnil;
}

902 903 904 905 906 907 908 909 910 911 912 913 914 915 916 917 918 919 920 921 922 923
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);
}

924
DEFUN ("load", Fload, Sload, 1, 5, 0,
925 926
       doc: /* Execute a file of Lisp code named FILE.
First try FILE with `.elc' appended, then try with `.el',
927
then try FILE unmodified (the exact suffixes in the exact order are
928
determined by `load-suffixes').  Environment variable references in
929
FILE are replaced with their values by calling `substitute-in-file-name'.
930
This function searches the directories in `load-path'.
931

932
If optional second arg NOERROR is non-nil,
933
report no error if FILE doesn't exist.
934
Print messages at start and end of loading unless
935
optional third arg NOMESSAGE is non-nil.
936
If optional fourth arg NOSUFFIX is non-nil, don't try adding
937
suffixes `.elc' or `.el' to the specified name FILE.
938
If optional fifth arg MUST-SUFFIX is non-nil, insist on
939 940 941 942 943 944 945 946 947 948 949 950 951 952 953
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.
954 955 956 957 958

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'.

959
Return t if the file exists and loads successfully.  */)
960
     (file, noerror, nomessage, nosuffix, must_suffix)
961
     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
Jim Blandy's avatar
Jim Blandy committed
962 963 964
{
  register FILE *stream;
  register int fd = -1;
Juanma Barranquero's avatar
Juanma Barranquero committed
965
  int count = SPECPDL_INDEX ();
966 967
  struct gcpro gcpro1, gcpro2, gcpro3;
  Lisp_Object found, efound, hist_file_name;
968 969 970 971
  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
972
  Lisp_Object handler;
973
  int safe_p = 1;
974
  char *fmode = "r";
975
  Lisp_Object tmp[2];
Kenichi Handa's avatar
Kenichi Handa committed
976 977
  int version;

978
#ifdef DOS_NT
979
  fmode = "rt";
980
#endif /* DOS_NT */
Jim Blandy's avatar
Jim Blandy committed
981

982
  CHECK_STRING (file);
Jim Blandy's avatar
Jim Blandy committed
983

984
  /* If file name is magic, call the handler.  */
985 986 987 988
  /* 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); */
989

990 991
  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
992 993
     (Below here, we care only whether they are nil or not.)
     The presence of this call is the result of a historical accident:
994
     it used to be in every file-operation and when it got removed
995 996 997
     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.  */
998 999 1000 1001 1002 1003 1004 1005 1006
  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);
1007

1008

Jim Blandy's avatar
Jim Blandy committed
1009 1010
  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
1011
  if (SCHARS (file) > 0)
Jim Blandy's avatar
Jim Blandy committed
1012
    {
1013
      int size = SBYTES (file);
1014

1015 1016
      found = Qnil;
      GCPRO2 (file, found);
1017 1018 1019 1020 1021

      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
1022
	      && !strcmp (SDATA (file) + size - 3, ".el"))
1023 1024
	    must_suffix = Qnil;
	  else if (size > 4
1025
		   && !strcmp (SDATA (file) + size - 4, ".elc"))
1026 1027 1028 1029 1030 1031 1032
	    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;
	}

1033
      fd = openp (Vload_path, file,
1034
		  (!NILP (nosuffix) ? Qnil
1035 1036 1037
		   : !NILP (must_suffix) ? Fget_load_suffixes ()
		   : Fappend (2, (tmp[0] = Fget_load_suffixes (),
				  tmp[1] = Vload_file_rep_suffixes,
1038
				  tmp))),
1039
		  &found, Qnil);
1040
      UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
1041 1042
    }

1043
  if (fd == -1)
Jim Blandy's avatar
Jim Blandy committed
1044
    {
Jim Blandy's avatar
Jim Blandy committed
1045
      if (NILP (noerror))
1046 1047
	xsignal2 (Qfile_error, build_string ("Cannot open load file"), file);
      return Qnil;
Jim Blandy's avatar
Jim Blandy committed
1048 1049
    }

1050
  /* Tell startup.el whether or not we found the user's init file.  */
Karl Heuer's avatar
Karl Heuer committed
1051 1052 1053
  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

1054 1055
  /* If FD is -2, that means openp found a magic file.  */
  if (fd == -2)
Richard M. Stallman's avatar