lread.c 134 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp parsing and input streams.
2

3 4
Copyright (C) 1985-1989, 1993-1995, 1997-2013 Free Software Foundation,
Inc.
Jim Blandy's avatar
Jim Blandy committed
5 6 7

This file is part of GNU Emacs.

8
GNU Emacs is free software: you can redistribute it and/or modify
Jim Blandy's avatar
Jim Blandy committed
9
it under the terms of the GNU General Public License as published by
10 11
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.
Jim Blandy's avatar
Jim Blandy committed
12 13 14 15 16 17 18

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
19
along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
Jim Blandy's avatar
Jim Blandy committed
20 21


Richard M. Stallman's avatar
Richard M. Stallman committed
22
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
23 24 25 26
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
27
#include <errno.h>
28
#include <limits.h>	/* For CHAR_BIT.  */
29
#include <stat-time.h>
Jim Blandy's avatar
Jim Blandy committed
30
#include "lisp.h"
31
#include "intervals.h"
Kenichi Handa's avatar
Kenichi Handa committed
32
#include "character.h"
33
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
34
#include "charset.h"
Kenichi Handa's avatar
Kenichi Handa committed
35
#include "coding.h"
36
#include <epaths.h>
Jim Blandy's avatar
Jim Blandy committed
37
#include "commands.h"
Jim Blandy's avatar
Jim Blandy committed
38
#include "keyboard.h"
39
#include "frame.h"
40
#include "termhooks.h"
41
#include "coding.h"
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
42
#include "blockinput.h"
Jim Blandy's avatar
Jim Blandy committed
43

44 45 46 47
#ifdef MSDOS
#include "msdos.h"
#endif

48 49 50 51
#ifdef HAVE_NS
#include "nsterm.h"
#endif

Andreas Schwab's avatar
Andreas Schwab committed
52
#include <unistd.h>
Jim Blandy's avatar
Jim Blandy committed
53

Richard M. Stallman's avatar
Richard M. Stallman committed
54 55 56 57
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Dave Love's avatar
Dave Love committed
58
#include <fcntl.h>
Richard M. Stallman's avatar
Richard M. Stallman committed
59

60
#ifdef HAVE_FSEEKO
61 62 63 64 65 66 67
#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

68
/* Hash table read constants.  */
69 70 71 72 73 74 75 76
static Lisp_Object Qhash_table, Qdata;
static Lisp_Object Qtest, Qsize;
static Lisp_Object Qweakness;
static Lisp_Object Qrehash_size;
static Lisp_Object Qrehash_threshold;

static Lisp_Object Qread_char, Qget_file_char, Qcurrent_load_list;
Lisp_Object Qstandard_input;
77
Lisp_Object Qvariable_documentation;
78
static Lisp_Object Qascii_character, Qload, Qload_file_name;
79
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
80 81
static Lisp_Object Qinhibit_file_name_operation;
static Lisp_Object Qeval_buffer_list;
82
Lisp_Object Qlexical_binding;
83
static Lisp_Object Qfile_truename, Qdo_after_load_evaluation; /* ACM 2006/5/16 */
84

Kenichi Handa's avatar
Kenichi Handa committed
85 86 87 88 89 90
/* 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;

91
static Lisp_Object Qload_in_progress;
Ken Raeburn's avatar
Ken Raeburn committed
92

93 94 95 96
/* 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.  */
97
static Lisp_Object read_objects;
98

99 100 101
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

102
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
103 104
static FILE *instream;

105
/* For use within read-from-string (this reader is non-reentrant!!)  */
106 107 108
static ptrdiff_t read_from_string_index;
static ptrdiff_t read_from_string_index_byte;
static ptrdiff_t read_from_string_limit;
109

110
/* Number of characters read in the current call to Fread or
111
   Fread_from_string.  */
112
static EMACS_INT readchar_count;
113

114
/* This contains the last string skipped with #@.  */
115 116
static char *saved_doc_string;
/* Length of buffer allocated in saved_doc_string.  */
117
static ptrdiff_t saved_doc_string_size;
118
/* Length of actual data in saved_doc_string.  */
119
static ptrdiff_t saved_doc_string_length;
120
/* This is the file position that string came from.  */
121
static file_offset saved_doc_string_position;
122

123 124 125 126 127
/* 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.  */
128
static ptrdiff_t prev_saved_doc_string_size;
129
/* Length of actual data in prev_saved_doc_string.  */
130
static ptrdiff_t prev_saved_doc_string_length;
131
/* This is the file position that string came from.  */
132
static file_offset prev_saved_doc_string_position;
133

134
/* True means inside a new-style backquote
135
   with no surrounding parentheses.
136
   Fread initializes this to false, so we need not specbind it
137
   or worry about what happens to it when there is an error.  */
138
static bool new_backquote_flag;
139
static Lisp_Object Qold_style_backquotes;
140 141 142 143

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

Lute Kamstra's avatar
Lute Kamstra committed
144
static Lisp_Object Vloads_in_progress;
145

146 147
static int read_emacs_mule_char (int, int (*) (int, Lisp_Object),
                                 Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
148

149
static void readevalloop (Lisp_Object, FILE *, Lisp_Object, bool,
150 151 152 153
                          Lisp_Object, Lisp_Object,
                          Lisp_Object, Lisp_Object);
static Lisp_Object load_unwind (Lisp_Object);
static Lisp_Object load_descriptor_unwind (Lisp_Object);
Jim Blandy's avatar
Jim Blandy committed
154

Kenichi Handa's avatar
Kenichi Handa committed
155 156 157 158 159 160
/* 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.  */

161 162 163
static int readbyte_for_lambda (int, Lisp_Object);
static int readbyte_from_file (int, Lisp_Object);
static int readbyte_from_string (int, Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
164

Jim Blandy's avatar
Jim Blandy committed
165 166
/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
167 168
   UNREAD(c) to unread c to be read again.

Kenichi Handa's avatar
Kenichi Handa committed
169
   These macros correctly read/unread multibyte characters.  */
Jim Blandy's avatar
Jim Blandy committed
170

171
#define READCHAR readchar (readcharfun, NULL)
Jim Blandy's avatar
Jim Blandy committed
172 173
#define UNREAD(c) unreadchar (readcharfun, c)

174 175 176
/* Same as READCHAR but set *MULTIBYTE to the multibyteness of the source.  */
#define READCHAR_REPORT_MULTIBYTE(multibyte) readchar (readcharfun, multibyte)

Kenichi Handa's avatar
Kenichi Handa committed
177
/* When READCHARFUN is Qget_file_char, Qget_emacs_mule_file_char,
Kenichi Handa's avatar
Kenichi Handa committed
178 179
   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
180
   means that there's no unread character.  */
Kenichi Handa's avatar
Kenichi Handa committed
181 182
static int unread_char;

Jim Blandy's avatar
Jim Blandy committed
183
static int
184
readchar (Lisp_Object readcharfun, bool *multibyte)
Jim Blandy's avatar
Jim Blandy committed
185 186
{
  Lisp_Object tem;
187
  register int c;
188
  int (*readbyte) (int, Lisp_Object);
Kenichi Handa's avatar
Kenichi Handa committed
189 190
  unsigned char buf[MAX_MULTIBYTE_LENGTH];
  int i, len;
191
  bool emacs_mule_encoding = 0;
Jim Blandy's avatar
Jim Blandy committed
192

193 194 195
  if (multibyte)
    *multibyte = 0;

196
  readchar_count++;
197

198
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
199
    {
200
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
201

202
      ptrdiff_t pt_byte = BUF_PT_BYTE (inbuffer);
203

204 205 206
      if (! BUFFER_LIVE_P (inbuffer))
	return -1;

207 208
      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
Jim Blandy's avatar
Jim Blandy committed
209

Tom Tromey's avatar
Tom Tromey committed
210
      if (! NILP (BVAR (inbuffer, enable_multibyte_characters)))
211
	{
212
	  /* Fetch the character code from the buffer.  */
213 214
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, pt_byte);
	  BUF_INC_POS (inbuffer, pt_byte);
215
	  c = STRING_CHAR (p);
216 217
	  if (multibyte)
	    *multibyte = 1;
218 219 220 221
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, pt_byte);
Kenichi Handa's avatar
Kenichi Handa committed
222 223
	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
224
	  pt_byte++;
225
	}
226
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
227

228
      return c;
Jim Blandy's avatar
Jim Blandy committed
229
    }
230
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
231
    {
232
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
233

234
      ptrdiff_t bytepos = marker_byte_position (readcharfun);
235

236 237
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
238

Tom Tromey's avatar
Tom Tromey committed
239
      if (! NILP (BVAR (inbuffer, enable_multibyte_characters)))
240
	{
241
	  /* Fetch the character code from the buffer.  */
242 243
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, bytepos);
	  BUF_INC_POS (inbuffer, bytepos);
244
	  c = STRING_CHAR (p);
245 246
	  if (multibyte)
	    *multibyte = 1;
247 248 249 250
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, bytepos);
Kenichi Handa's avatar
Kenichi Handa committed
251 252
	  if (! ASCII_BYTE_P (c))
	    c = BYTE8_TO_CHAR (c);
253
	  bytepos++;
254 255
	}

256 257 258 259
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
260
    }
261 262

  if (EQ (readcharfun, Qlambda))
Kenichi Handa's avatar
Kenichi Handa committed
263 264 265 266
    {
      readbyte = readbyte_for_lambda;
      goto read_multibyte;
    }
267

Jim Blandy's avatar
Jim Blandy committed
268
  if (EQ (readcharfun, Qget_file_char))
269
    {
Kenichi Handa's avatar
Kenichi Handa committed
270 271
      readbyte = readbyte_from_file;
      goto read_multibyte;
272
    }
Jim Blandy's avatar
Jim Blandy committed
273

274
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
275
    {
276
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
277
	c = -1;
278 279 280 281 282 283 284 285
      else if (STRING_MULTIBYTE (readcharfun))
	{
	  if (multibyte)
	    *multibyte = 1;
	  FETCH_STRING_CHAR_ADVANCE_NO_CHECK (c, readcharfun,
					      read_from_string_index,
					      read_from_string_index_byte);
	}
286
      else
287 288 289 290 291
	{
	  c = SREF (readcharfun, read_from_string_index_byte);
	  read_from_string_index++;
	  read_from_string_index_byte++;
	}
Jim Blandy's avatar
Jim Blandy committed
292 293 294
      return c;
    }

Kenichi Handa's avatar
Kenichi Handa committed
295 296 297 298 299 300 301 302 303 304 305 306
  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
307

Kenichi Handa's avatar
Kenichi Handa committed
308 309 310 311 312 313
  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
314 315 316

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
317
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
318 319
    return -1;
  return XINT (tem);
Kenichi Handa's avatar
Kenichi Handa committed
320 321 322 323 324 325 326 327 328

 read_multibyte:
  if (unread_char >= 0)
    {
      c = unread_char;
      unread_char = -1;
      return c;
    }
  c = (*readbyte) (-1, readcharfun);
329
  if (c < 0)
330 331 332 333
    return c;
  if (multibyte)
    *multibyte = 1;
  if (ASCII_BYTE_P (c))
Kenichi Handa's avatar
Kenichi Handa committed
334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350
    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;
    }
351
  return STRING_CHAR (buf);
Jim Blandy's avatar
Jim Blandy committed
352 353
}

Stefan Monnier's avatar
Stefan Monnier committed
354 355 356 357
#define FROM_FILE_P(readcharfun)			\
  (EQ (readcharfun, Qget_file_char)			\
   || EQ (readcharfun, Qget_emacs_mule_file_char))

358 359 360
static void
skip_dyn_bytes (Lisp_Object readcharfun, ptrdiff_t n)
{
Stefan Monnier's avatar
Stefan Monnier committed
361
  if (FROM_FILE_P (readcharfun))
362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380
    {
      block_input ();		/* FIXME: Not sure if it's needed.  */
      fseek (instream, n, SEEK_CUR);
      unblock_input ();
    }
  else
    { /* We're not reading directly from a file.  In that case, it's difficult
	 to reliably count bytes, since these are usually meant for the file's
	 encoding, whereas we're now typically in the internal encoding.
	 But luckily, skip_dyn_bytes is used to skip over a single
	 dynamic-docstring (or dynamic byte-code) which is always quoted such
	 that \037 is the final char.  */
      int c;
      do {
	c = READCHAR;
      } while (c >= 0 && c != '\037');
    }
}

Jim Blandy's avatar
Jim Blandy committed
381 382 383 384
/* 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
385
unreadchar (Lisp_Object readcharfun, int c)
Jim Blandy's avatar
Jim Blandy committed
386
{
387
  readchar_count--;
388 389 390 391
  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.  */
    ;
392
  else if (BUFFERP (readcharfun))
393
    {
394
      struct buffer *b = XBUFFER (readcharfun);
395 396
      ptrdiff_t charpos = BUF_PT (b);
      ptrdiff_t bytepos = BUF_PT_BYTE (b);
397

Tom Tromey's avatar
Tom Tromey committed
398
      if (! NILP (BVAR (b, enable_multibyte_characters)))
Kenichi Handa's avatar
Kenichi Handa committed
399
	BUF_DEC_POS (b, bytepos);
400
      else
Kenichi Handa's avatar
Kenichi Handa committed
401
	bytepos--;
402

403
      SET_BUF_PT_BOTH (b, charpos - 1, bytepos);
404
    }
405
  else if (MARKERP (readcharfun))
406
    {
407
      struct buffer *b = XMARKER (readcharfun)->buffer;
408
      ptrdiff_t bytepos = XMARKER (readcharfun)->bytepos;
409

Kenichi Handa's avatar
Kenichi Handa committed
410
      XMARKER (readcharfun)->charpos--;
Tom Tromey's avatar
Tom Tromey committed
411
      if (! NILP (BVAR (b, enable_multibyte_characters)))
Kenichi Handa's avatar
Kenichi Handa committed
412
	BUF_DEC_POS (b, bytepos);
413
      else
Kenichi Handa's avatar
Kenichi Handa committed
414
	bytepos--;
415

Kenichi Handa's avatar
Kenichi Handa committed
416
      XMARKER (readcharfun)->bytepos = bytepos;
417
    }
418
  else if (STRINGP (readcharfun))
419 420 421 422 423
    {
      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
424 425 426 427
  else if (CONSP (readcharfun))
    {
      unread_char = c;
    }
428
  else if (EQ (readcharfun, Qlambda))
Kenichi Handa's avatar
Kenichi Handa committed
429 430 431
    {
      unread_char = c;
    }
Stefan Monnier's avatar
Stefan Monnier committed
432
  else if (FROM_FILE_P (readcharfun))
Kenichi Handa's avatar
Kenichi Handa committed
433
    {
434
      unread_char = c;
Kenichi Handa's avatar
Kenichi Handa committed
435
    }
Jim Blandy's avatar
Jim Blandy committed
436 437 438 439
  else
    call1 (readcharfun, make_number (c));
}

Kenichi Handa's avatar
Kenichi Handa committed
440
static int
441
readbyte_for_lambda (int c, Lisp_Object readcharfun)
Kenichi Handa's avatar
Kenichi Handa committed
442 443 444 445 446 447
{
  return read_bytecode_char (c >= 0);
}


static int
448
readbyte_from_file (int c, Lisp_Object readcharfun)
Kenichi Handa's avatar
Kenichi Handa committed
449 450 451
{
  if (c >= 0)
    {
452
      block_input ();
Kenichi Handa's avatar
Kenichi Handa committed
453
      ungetc (c, instream);
454
      unblock_input ();
Kenichi Handa's avatar
Kenichi Handa committed
455 456 457
      return 0;
    }

458
  block_input ();
Kenichi Handa's avatar
Kenichi Handa committed
459
  c = getc (instream);
Miles Bader's avatar
Miles Bader committed
460

461
  /* Interrupted reads have been observed while reading over the network.  */
Miles Bader's avatar
Miles Bader committed
462 463
  while (c == EOF && ferror (instream) && errno == EINTR)
    {
464
      unblock_input ();
Miles Bader's avatar
Miles Bader committed
465
      QUIT;
466
      block_input ();
Miles Bader's avatar
Miles Bader committed
467
      clearerr (instream);
Miles Bader's avatar
Miles Bader committed
468
      c = getc (instream);
YAMAMOTO Mitsuharu's avatar
YAMAMOTO Mitsuharu committed
469
    }
Miles Bader's avatar
Miles Bader committed
470

471
  unblock_input ();
Miles Bader's avatar
Miles Bader committed
472

Kenichi Handa's avatar
Kenichi Handa committed
473 474 475 476
  return (c == EOF ? -1 : c);
}

static int
477
readbyte_from_string (int c, Lisp_Object readcharfun)
Kenichi Handa's avatar
Kenichi Handa committed
478 479 480 481 482 483 484 485 486
{
  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
487

Kenichi Handa's avatar
Kenichi Handa committed
488 489 490 491 492 493 494 495 496 497 498 499 500 501 502
  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.  */

static int
503
read_emacs_mule_char (int c, int (*readbyte) (int, Lisp_Object), Lisp_Object readcharfun)
Kenichi Handa's avatar
Kenichi Handa committed
504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531
{
  /* 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)
    {
532
      charset = CHARSET_FROM_ID (emacs_mule_charset[buf[0]]);
Kenichi Handa's avatar
Kenichi Handa committed
533 534 535 536 537 538 539
      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)
	{
540
	  charset = CHARSET_FROM_ID (emacs_mule_charset[buf[1]]);
Kenichi Handa's avatar
Kenichi Handa committed
541 542 543 544
	  code = buf[2] & 0x7F;
	}
      else
	{
545
	  charset = CHARSET_FROM_ID (emacs_mule_charset[buf[0]]);
Kenichi Handa's avatar
Kenichi Handa committed
546 547 548 549 550
	  code = ((buf[1] << 8) | buf[2]) & 0x7F7F;
	}
    }
  else
    {
551
      charset = CHARSET_FROM_ID (emacs_mule_charset[buf[1]]);
Kenichi Handa's avatar
Kenichi Handa committed
552
      code = ((buf[2] << 8) | buf[3]) & 0x7F7F;
Kenichi Handa's avatar
Kenichi Handa committed
553 554 555 556 557 558 559 560 561
    }
  c = DECODE_CHAR (charset, code);
  if (c < 0)
    Fsignal (Qinvalid_read_syntax,
	     Fcons (build_string ("invalid multibyte form"), Qnil));
  return c;
}


562 563 564
static Lisp_Object read_internal_start (Lisp_Object, Lisp_Object,
                                        Lisp_Object);
static Lisp_Object read0 (Lisp_Object);
565
static Lisp_Object read1 (Lisp_Object, int *, bool);
566

567 568
static Lisp_Object read_list (bool, Lisp_Object);
static Lisp_Object read_vector (Lisp_Object, bool);
569

570 571 572 573 574
static Lisp_Object substitute_object_recurse (Lisp_Object, Lisp_Object,
                                              Lisp_Object);
static void substitute_object_in_subtree (Lisp_Object,
                                          Lisp_Object);
static void substitute_in_interval (INTERVAL, Lisp_Object);
575

Jim Blandy's avatar
Jim Blandy committed
576

577
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
578

579 580
/* Read input events until we get one that's acceptable for our purposes.

581
   If NO_SWITCH_FRAME, switch-frame events are stashed
582 583 584
   until we get a character we like, and then stuffed into
   unread_switch_frame.

585
   If ASCII_REQUIRED, check function key events to see
586 587 588
   if the unmodified version of the symbol has a Qascii_character
   property, and use that character, if present.

589 590 591
   If ERROR_NONASCII, signal an error if the input we
   get isn't an ASCII character with modifiers.  If it's false but
   ASCII_REQUIRED is true, just re-read until we get an ASCII
592 593
   character.

594
   If INPUT_METHOD, invoke the current input method
595 596
   if the character warrants that.

597
   If SECONDS is a number, wait that many seconds for input, and
598
   return Qnil if no input arrives within that time.  */
599

Andreas Schwab's avatar
Andreas Schwab committed
600
static Lisp_Object
601 602
read_filtered_event (bool no_switch_frame, bool ascii_required,
		     bool error_nonascii, bool input_method, Lisp_Object seconds)
603
{
604
  Lisp_Object val, delayed_switch_frame;
605
  EMACS_TIME end_time;
606

607
#ifdef HAVE_WINDOW_SYSTEM
608 609
  if (display_hourglass_p)
    cancel_hourglass ();
610
#endif
611

612
  delayed_switch_frame = Qnil;
613

614 615 616
  /* Compute timeout.  */
  if (NUMBERP (seconds))
    {
617
      double duration = extract_float (seconds);
618
      EMACS_TIME wait_time = EMACS_TIME_FROM_DOUBLE (duration);
619
      end_time = add_emacs_time (current_emacs_time (), wait_time);
620 621
    }

622
  /* Read until we get an acceptable event.  */
623
 retry:
624
  do
625
    val = read_char (0, Qnil, (input_method ? Qnil : Qt), 0,
Karoly Lorentey's avatar
Karoly Lorentey committed
626
		     NUMBERP (seconds) ? &end_time : NULL);
627
  while (INTEGERP (val) && XINT (val) == -2); /* wrong_kboard_jmpbuf */
628

629
  if (BUFFERP (val))
630 631
    goto retry;

632
  /* `switch-frame' events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
633
     character.  This is better than signaling an error just because
634 635 636 637 638
     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)
639
      && EQ (EVENT_HEAD_KIND (EVENT_HEAD (val)), Qswitch_frame))
640 641 642 643 644
    {
      delayed_switch_frame = val;
      goto retry;
    }

645
  if (ascii_required && !(NUMBERP (seconds) && NILP (val)))
646 647
    {
      /* Convert certain symbols to their ASCII equivalents.  */
648
      if (SYMBOLP (val))
649
	{
650
	  Lisp_Object tem, tem1;
651 652 653 654 655 656 657
	  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))
658
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
659 660
	    }
	}
661

662
      /* If we don't have a character now, deal with it appropriately.  */
663
      if (!INTEGERP (val))
664 665 666
	{
	  if (error_nonascii)
	    {
667
	      Vunread_command_events = Fcons (val, Qnil);
668 669 670 671 672 673 674 675 676 677
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

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

678 679
#if 0

680
#ifdef HAVE_WINDOW_SYSTEM
681 682
  if (display_hourglass_p)
    start_hourglass ();
683
#endif
684 685 686

#endif

687 688 689
  return val;
}

Paul Eggert's avatar
Paul Eggert committed
690
DEFUN ("read-char", Fread_char, Sread_char, 0, 3, 0,
691 692
       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.
693 694 695
If the character has modifiers, they are resolved and reflected to the
character code if possible (e.g. C-SPC -> 0).

696 697
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
698 699
exception, switch-frame events are put off until non-character events
can be read.
700 701 702 703 704 705
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
706 707 708 709 710
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.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
711
  (Lisp_Object prompt, Lisp_Object inherit_input_method, Lisp_Object seconds)
Jim Blandy's avatar
Jim Blandy committed
712
{
713 714
  Lisp_Object val;

715 716
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
717
  val = read_filtered_event (1, 1, 1, ! NILP (inherit_input_method), seconds);
718 719 720

  return (NILP (val) ? Qnil
	  : make_number (char_resolve_modifier_mask (XINT (val))));
Jim Blandy's avatar
Jim Blandy committed
721 722
}

Paul Eggert's avatar
Paul Eggert committed
723
DEFUN ("read-event", Fread_event, Sread_event, 0, 3, 0,
724 725 726 727
       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
728 729 730 731 732
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.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
733
  (Lisp_Object prompt, Lisp_Object inherit_input_method, Lisp_Object seconds)
Jim Blandy's avatar
Jim Blandy committed
734
{
735 736
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
737
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method), seconds);
Jim Blandy's avatar
Jim Blandy committed
738 739
}

740
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 3, 0,
741 742
       doc: /* Read a character from the command input (keyboard or macro).
It is returned as a number.  Non-character events are ignored.
743 744
If the character has modifiers, they are resolved and reflected to the
character code if possible (e.g. C-SPC -> 0).
745 746 747 748

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
749 750 751 752 753
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.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
754
  (Lisp_Object prompt, Lisp_Object inherit_input_method, Lisp_Object seconds)
Jim Blandy's avatar
Jim Blandy committed
755
{
756 757
  Lisp_Object val;

758 759
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
760

761
  val = read_filtered_event (1, 1, 0, ! NILP (inherit_input_method), seconds);
762 763 764

  return (NILP (val) ? Qnil
	  : make_number (char_resolve_modifier_mask (XINT (val))));
Jim Blandy's avatar
Jim Blandy committed
765 766 767
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
768
       doc: /* Don't use this yourself.  */)
Dan Nicolaescu's avatar
Dan Nicolaescu committed
769
  (void)
Jim Blandy's avatar
Jim Blandy committed
770 771
{
  register Lisp_Object val;
772
  block_input ();
773
  XSETINT (val, getc (instream));
774
  unblock_input ();
Jim Blandy's avatar
Jim Blandy committed
775 776
  return val;
}
777 778


779 780 781 782


/* Return true if the lisp code read using READCHARFUN defines a non-nil
   `lexical-binding' file variable.  After returning, the stream is
783 784
   positioned following the first line, if it is a comment or #! line,
   otherwise nothing is read.  */
785

786
static bool
Stefan Monnier's avatar
Stefan Monnier committed
787
lisp_file_lexically_bound_p (Lisp_Object readcharfun)
788 789
{
  int ch = READCHAR;
790 791 792 793 794 795 796 797 798 799 800 801 802

  if (ch == '#')
    {
      ch = READCHAR;
      if (ch != '!')
        {
          UNREAD (ch);
          UNREAD ('#');
          return 0;
        }
      while (ch != '\n' && ch != EOF)
        ch = READCHAR;
      if (ch == '\n') ch = READCHAR;
Glenn Morris's avatar
Comment  
Glenn Morris committed
803 804
      /* It is OK to leave the position after a #! line, since
         that is what read1 does.  */
805 806
    }

807 808 809 810 811 812 813 814 815
  if (ch != ';')
    /* The first line isn't a comment, just give up.  */
    {
      UNREAD (ch);
      return 0;
    }
  else
    /* Look for an appropriate file-variable in the first line.  */
    {
816
      bool rv = 0;
817 818 819
      enum {
	NOMINAL, AFTER_FIRST_DASH, AFTER_ASTERIX,
      } beg_end_state = NOMINAL;
820
      bool in_file_vars = 0;
821

822 823 824 825 826 827 828 829 830 831
#define UPDATE_BEG_END_STATE(ch)				\
  if (beg_end_state == NOMINAL)					\
    beg_end_state = (ch == '-' ? AFTER_FIRST_DASH : NOMINAL);	\
  else if (beg_end_state == AFTER_FIRST_DASH)			\
    beg_end_state = (ch == '*' ? AFTER_ASTERIX : NOMINAL);	\
  else if (beg_end_state == AFTER_ASTERIX)			\
    {								\
      if (ch == '-')						\
	in_file_vars = !in_file_vars;				\
      beg_end_state = NOMINAL;					\
832 833 834 835 836 837 838 839 840 841 842 843
    }

      /* Skip until we get to the file vars, if any.  */
      do
	{
	  ch = READCHAR;
	  UPDATE_BEG_END_STATE (ch);
	}
      while (!in_file_vars && ch != '\n' && ch != EOF);

      while (in_file_vars)
	{
844
	  char var[100], val[100];
845
	  unsigned i;
846 847 848 849 850 851 852

	  ch = READCHAR;

	  /* Read a variable name.  */
	  while (ch == ' ' || ch == '\t')
	    ch = READCHAR;

853
	  i = 0;
854
	  while (ch != ':' && ch != '\n' && ch != EOF && in_file_vars)
855
	    {
856 857
	      if (i < sizeof var - 1)
		var[i++] = ch;
858 859 860
	      UPDATE_BEG_END_STATE (ch);
	      ch = READCHAR;
	    }
861

862
	  /* Stop scanning if no colon was found before end marker.  */
863
	  if (!in_file_vars || ch == '\n' || ch == EOF)
864 865
	    break;

866 867 868
	  while (i > 0 && (var[i - 1] == ' ' || var[i - 1] == '\t'))
	    i--;
	  var[i] = '\0';
869 870 871 872 873 874 875 876 877

	  if (ch == ':')
	    {
	      /* Read a variable value.  */
	      ch = READCHAR;

	      while (ch == ' ' || ch == '\t')
		ch = READCHAR;

878
	      i = 0;
879 880
	      while (ch != ';' && ch != '\n' && ch != EOF && in_file_vars)
		{
881 882
		  if (i < sizeof val - 1)
		    val[i++] = ch;
883 884 885 886
		  UPDATE_BEG_END_STATE (ch);
		  ch = READCHAR;
		}
	      if (! in_file_vars)
887
		/* The value was terminated by an end-marker, which remove.  */
888 889 890 891
		i -= 3;
	      while (i > 0 && (val[i - 1] == ' ' || val[i - 1] == '\t'))
		i--;
	      val[i] = '\0';
892 893 894 895 896 897 898 899 900 901 902 903 904 905 906 907

	      if (strcmp (var, "lexical-binding") == 0)
		/* This is it...  */
		{
		  rv = (strcmp (val, "nil") != 0);
		  break;
		}
	    }
	}

      while (ch != '\n' && ch != EOF)
	ch = READCHAR;

      return rv;
    }
}
908

Kenichi Handa's avatar
Kenichi Handa committed
909
/* Value is a version number of byte compiled code if the file
Miles Bader's avatar
Miles Bader committed
910
   associated with file descriptor FD is a compiled Lisp file that's
Kenichi Handa's avatar
Kenichi Handa committed
911 912 913
   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.  */
914 915

static int
916
safe_to_load_version (int fd)
917 918 919
{
  char buf[512];
  int nbytes, i;
Kenichi Handa's avatar
Kenichi Handa committed
920
  int version = 1;
921 922 923

  /* Read the first few bytes from the file, and look for a line
     specifying the byte compiler version used.  */
924
  nbytes = emacs_read (fd, buf, sizeof buf);
925 926 927
  if (nbytes > 0)
    {
      /* Skip to the next newline, skipping over the initial `ELC'
Dave Love's avatar
Dave Love committed
928
	 with NUL bytes following it, but note the version.  */
929
      for (i = 0; i < nbytes && buf[i] != '\n'; ++i)
Dave Love's avatar
Dave Love committed
930
	if (i == 4)
Kenichi Handa's avatar
Kenichi Handa committed
931
	  version = buf[i];
932

933
      if (i >= nbytes
934
	  || fast_c_string_match_ignore_case (Vbytecomp_version_regexp,