lread.c 109 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp parsing and input streams.
2 3 4
   Copyright (C) 1985, 1986, 1987, 1988, 1989, 1993, 1994, 1995,
                 1997, 1998, 1999, 2000, 2001, 2002, 2003, 2004,
                 2005 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
Jim Blandy's avatar
Jim Blandy committed
10
the Free Software Foundation; either version 2, 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"
Jim Blandy's avatar
Jim Blandy committed
39 40 41 42 43

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

44 45 46 47 48 49 50
#ifdef MSDOS
#if __DJGPP__ < 2
#include <unistd.h>	/* to get X_OK */
#endif
#include "msdos.h"
#endif

Andreas Schwab's avatar
Andreas Schwab committed
51 52 53 54
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif

Jim Blandy's avatar
Jim Blandy committed
55 56 57 58 59 60
#ifndef X_OK
#define X_OK 01
#endif

#include <math.h>

Richard M. Stallman's avatar
Richard M. Stallman committed
61 62 63 64
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Dave Love's avatar
Dave Love committed
65 66 67
#ifdef HAVE_FCNTL_H
#include <fcntl.h>
#endif
Richard M. Stallman's avatar
Richard M. Stallman committed
68 69 70 71
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

72
#ifdef HAVE_FSEEKO
73 74 75 76 77 78 79
#define file_offset off_t
#define file_tell ftello
#else
#define file_offset long
#define file_tell ftell
#endif

80
#ifndef USE_CRT_DLL
81
extern int errno;
82
#endif
83

84
Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
Jim Blandy's avatar
Jim Blandy committed
85
Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
86
Lisp_Object Qascii_character, Qload, Qload_file_name;
87
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
88
Lisp_Object Qinhibit_file_name_operation;
89
Lisp_Object Qeval_buffer_list, Veval_buffer_list;
90 91

extern Lisp_Object Qevent_symbol_element_mask;
92
extern Lisp_Object Qfile_exists_p;
Jim Blandy's avatar
Jim Blandy committed
93

Lute Kamstra's avatar
Lute Kamstra committed
94
/* non-zero iff inside `load' */
Jim Blandy's avatar
Jim Blandy committed
95 96
int load_in_progress;

97 98 99
/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

100 101
/* Search path and suffixes for files to be loaded. */
Lisp_Object Vload_path, Vload_suffixes, default_suffixes;
Jim Blandy's avatar
Jim Blandy committed
102

Karl Heuer's avatar
Karl Heuer committed
103 104 105
/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

106 107 108 109
/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

110
/* This is used to build the load history. */
111 112
Lisp_Object Vcurrent_load_list;

113 114 115
/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

116 117 118
/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

119 120 121
/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

122 123 124 125 126 127
/* 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;

128 129 130
/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

131 132 133
/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

Karl Heuer's avatar
Karl Heuer committed
134 135 136 137
/* Function to use for loading an Emacs lisp source file (not
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

138 139 140
/* List of all DEFVAR_BOOL variables.  Used by the byte optimizer.  */
Lisp_Object Vbyte_boolean_vars;

141 142 143 144 145 146 147
/* 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;

148 149 150
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

151
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
152 153 154 155 156
static FILE *instream;

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

157
/* For use within read-from-string (this reader is non-reentrant!!)  */
Jim Blandy's avatar
Jim Blandy committed
158
static int read_from_string_index;
159
static int read_from_string_index_byte;
Jim Blandy's avatar
Jim Blandy committed
160
static int read_from_string_limit;
161

162 163 164
/* Number of bytes left to read in the buffer character
   that `readchar' has already advanced over.  */
static int readchar_backlog;
165 166 167
/* Number of characters read in the current call to Fread or
   Fread_from_string. */
static int readchar_count;
168

169
/* This contains the last string skipped with #@.  */
170 171 172 173 174 175
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.  */
176
static file_offset saved_doc_string_position;
177

178 179 180 181 182 183 184 185 186
/* 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.  */
187
static file_offset prev_saved_doc_string_position;
188

189 190 191 192 193
/* 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;
194 195 196 197

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

Lute Kamstra's avatar
Lute Kamstra committed
198
static Lisp_Object Vloads_in_progress;
199

200 201 202 203 204 205 206 207
/* 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
208
static void to_multibyte P_ ((char **, char **, int *));
209
static void readevalloop P_ ((Lisp_Object, FILE*, Lisp_Object,
210
			      Lisp_Object (*) (), int,
211
			      Lisp_Object, Lisp_Object,
212 213 214 215
			      Lisp_Object, Lisp_Object));
static Lisp_Object load_unwind P_ ((Lisp_Object));
static Lisp_Object load_descriptor_unwind P_ ((Lisp_Object));

Jim Blandy's avatar
Jim Blandy committed
216 217 218

/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
219 220
   UNREAD(c) to unread c to be read again.

221 222 223
   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.
224

225 226 227 228
   [ 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
229
 */
Jim Blandy's avatar
Jim Blandy committed
230 231 232 233 234 235 236 237 238

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

static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
239
  register int c;
Jim Blandy's avatar
Jim Blandy committed
240

241
  readchar_count++;
242

243
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
244
    {
245
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
246

247 248
      int pt_byte = BUF_PT_BYTE (inbuffer);
      int orig_pt_byte = pt_byte;
249

250 251 252 253 254 255 256 257
      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);

258 259
      if (pt_byte >= BUF_ZV_BYTE (inbuffer))
	return -1;
Jim Blandy's avatar
Jim Blandy committed
260

261 262
      readchar_backlog = -1;

263 264
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
265
	  /* Fetch the character code from the buffer.  */
266 267 268 269 270 271 272 273
	  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++;
274
	}
275
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
276

277
      return c;
Jim Blandy's avatar
Jim Blandy committed
278
    }
279
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
280
    {
281
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
282

283 284
      int bytepos = marker_byte_position (readcharfun);
      int orig_bytepos = bytepos;
285

286 287 288 289 290 291 292 293
      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);

294 295
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
296

297 298
      readchar_backlog = -1;

299 300
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
301
	  /* Fetch the character code from the buffer.  */
302 303 304 305 306 307 308 309
	  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++;
310 311
	}

312 313 314 315
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
316
    }
317 318 319 320

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

Jim Blandy's avatar
Jim Blandy committed
321
  if (EQ (readcharfun, Qget_file_char))
322 323 324 325 326 327
    {
      c = getc (instream);
#ifdef EINTR
      /* Interrupted reads have been observed while reading over the network */
      while (c == EOF && ferror (instream) && errno == EINTR)
	{
328
	  QUIT;
329 330 331 332 333 334
	  clearerr (instream);
	  c = getc (instream);
	}
#endif
      return c;
    }
Jim Blandy's avatar
Jim Blandy committed
335

336
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
337
    {
338
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
339
	c = -1;
340
      else
341 342 343
	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
344

Jim Blandy's avatar
Jim Blandy committed
345 346 347 348 349
      return c;
    }

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
350
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
351 352 353 354 355 356 357 358 359 360 361 362
    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;
{
363
  readchar_count--;
364 365 366 367
  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.  */
    ;
368
  else if (BUFFERP (readcharfun))
369
    {
370 371
      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
372

373 374
      if (readchar_backlog >= 0)
	readchar_backlog++;
375
      else
376 377 378 379 380 381
	{
	  BUF_PT (b)--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
382

383 384
	  BUF_PT_BYTE (b) = bytepos;
	}
385
    }
386
  else if (MARKERP (readcharfun))
387
    {
388 389
      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
390

391 392
      if (readchar_backlog >= 0)
	readchar_backlog++;
393
      else
394 395 396 397 398 399
	{
	  XMARKER (readcharfun)->charpos--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
400

401 402
	  XMARKER (readcharfun)->bytepos = bytepos;
	}
403
    }
404
  else if (STRINGP (readcharfun))
405 406 407 408 409
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
410 411
  else if (EQ (readcharfun, Qlambda))
    read_bytecode_char (1);
Jim Blandy's avatar
Jim Blandy committed
412 413 414 415 416 417
  else if (EQ (readcharfun, Qget_file_char))
    ungetc (c, instream);
  else
    call1 (readcharfun, make_number (c));
}

418 419 420
static Lisp_Object read_internal_start P_ ((Lisp_Object, Lisp_Object,
					    Lisp_Object));
static Lisp_Object read0 P_ ((Lisp_Object));
421
static Lisp_Object read1 P_ ((Lisp_Object, int *, int));
422 423 424 425 426 427 428 429 430 431

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));
432

Jim Blandy's avatar
Jim Blandy committed
433

434
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
435

436 437
extern Lisp_Object read_char ();

438 439 440 441 442 443 444 445 446 447 448 449 450
/* 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
451 452 453 454
   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
   if the character warrants that.  */
455

456
Lisp_Object
457 458 459
read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
		     input_method)
     int no_switch_frame, ascii_required, error_nonascii, input_method;
460
{
461 462
  register Lisp_Object val, delayed_switch_frame;

463
#ifdef HAVE_WINDOW_SYSTEM
464 465
  if (display_hourglass_p)
    cancel_hourglass ();
466
#endif
467

468
  delayed_switch_frame = Qnil;
469 470 471

  /* Read until we get an acceptable event.  */
 retry:
472 473 474
  val = read_char (0, 0, 0,
		   (input_method ? Qnil : Qt),
		   0);
475

476
  if (BUFFERP (val))
477 478
    goto retry;

479
  /* switch-frame events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
480
     character.  This is better than signaling an error just because
481 482 483 484 485 486 487 488 489 490 491 492 493 494
     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)
      && EQ (EVENT_HEAD (val), Qswitch_frame))
    {
      delayed_switch_frame = val;
      goto retry;
    }

  if (ascii_required)
    {
      /* Convert certain symbols to their ASCII equivalents.  */
495
      if (SYMBOLP (val))
496
	{
497
	  Lisp_Object tem, tem1;
498 499 500 501 502 503 504
	  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))
505
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
506 507
	    }
	}
508

509
      /* If we don't have a character now, deal with it appropriately.  */
510
      if (!INTEGERP (val))
511 512 513
	{
	  if (error_nonascii)
	    {
514
	      Vunread_command_events = Fcons (val, Qnil);
515 516 517 518 519 520 521 522 523 524
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

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

525 526
#if 0

527
#ifdef HAVE_WINDOW_SYSTEM
528 529
  if (display_hourglass_p)
    start_hourglass ();
530
#endif
531 532 533

#endif

534 535 536
  return val;
}

537
DEFUN ("read-char", Fread_char, Sread_char, 0, 2, 0,
538 539 540 541 542 543 544 545 546 547 548 549 550 551
       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
is used for reading a character.  */)
     (prompt, inherit_input_method)
552
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
553
{
554 555
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
556
  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
557 558
}

559
DEFUN ("read-event", Fread_event, Sread_event, 0, 2, 0,
560 561 562 563 564 565
       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
is used for reading a character.  */)
     (prompt, inherit_input_method)
566
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
567
{
568 569
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
570
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
571 572
}

573
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 2, 0,
574 575 576 577 578 579 580 581
       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
is used for reading a character.  */)
     (prompt, inherit_input_method)
582
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
583
{
584 585
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
586
  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
587 588 589
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
590 591
       doc: /* Don't use this yourself.  */)
     ()
Jim Blandy's avatar
Jim Blandy committed
592 593
{
  register Lisp_Object val;
594
  XSETINT (val, getc (instream));
Jim Blandy's avatar
Jim Blandy committed
595 596
  return val;
}
597 598


599

600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636
/* 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;
}


637 638 639 640 641 642 643 644 645 646
/* 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;
}

647 648 649 650 651 652 653 654
/* This handler function is used via internal_condition_case_1.  */

static Lisp_Object
load_error_handler (data)
     Lisp_Object data;
{
  return Qnil;
}
655

656
DEFUN ("load", Fload, Sload, 1, 5, 0,
657 658
       doc: /* Execute a file of Lisp code named FILE.
First try FILE with `.elc' appended, then try with `.el',
Markus Rost's avatar
Markus Rost committed
659 660
 then try FILE unmodified (the exact suffixes are determined by
`load-suffixes').  Environment variable references in FILE
661 662 663 664 665 666 667 668 669 670 671 672 673
 are replaced with their values by calling `substitute-in-file-name'.
This function searches the directories in `load-path'.
If optional second arg NOERROR is non-nil,
 report no error if FILE doesn't exist.
Print messages at start and end of loading unless
 optional third arg NOMESSAGE is non-nil.
If optional fourth arg NOSUFFIX is non-nil, don't try adding
 suffixes `.elc' or `.el' to the specified name FILE.
If optional fifth arg MUST-SUFFIX is non-nil, insist on
 the suffix `.elc' or `.el'; don't accept just FILE unless
 it ends in one of those suffixes or includes a directory name.
Return t if file exists.  */)
     (file, noerror, nomessage, nosuffix, must_suffix)
674
     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
Jim Blandy's avatar
Jim Blandy committed
675 676 677
{
  register FILE *stream;
  register int fd = -1;
Juanma Barranquero's avatar
Juanma Barranquero committed
678
  int count = SPECPDL_INDEX ();
Jim Blandy's avatar
Jim Blandy committed
679 680
  Lisp_Object temp;
  struct gcpro gcpro1;
681
  Lisp_Object found, efound;
682 683 684 685
  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
686
  Lisp_Object handler;
687
  int safe_p = 1;
688
  char *fmode = "r";
689
#ifdef DOS_NT
690
  fmode = "rt";
691
#endif /* DOS_NT */
Jim Blandy's avatar
Jim Blandy committed
692

693
  CHECK_STRING (file);
Jim Blandy's avatar
Jim Blandy committed
694

695
  /* If file name is magic, call the handler.  */
696 697 698 699
  /* 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); */
700

701 702
  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
703 704 705 706 707 708
     (Below here, we care only whether they are nil or not.)
     The presence of this call is the result of a historical accident:
     it used to be in every file-operations and when it got removed
     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.  */
709 710 711 712 713 714 715 716 717
  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);
718

719

Jim Blandy's avatar
Jim Blandy committed
720 721
  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
722
  if (SCHARS (file) > 0)
Jim Blandy's avatar
Jim Blandy committed
723
    {
724
      int size = SBYTES (file);
725
      Lisp_Object tmp[2];
726

727
      GCPRO1 (file);
728 729 730 731 732

      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
733
	      && !strcmp (SDATA (file) + size - 3, ".el"))
734 735
	    must_suffix = Qnil;
	  else if (size > 4
736
		   && !strcmp (SDATA (file) + size - 4, ".elc"))
737 738 739 740 741 742 743
	    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;
	}

744
      fd = openp (Vload_path, file,
745 746 747 748 749
		  (!NILP (nosuffix) ? Qnil
		   : !NILP (must_suffix) ? Vload_suffixes
		   : Fappend (2, (tmp[0] = Vload_suffixes,
				  tmp[1] = default_suffixes,
				  tmp))),
750
		  &found, Qnil);
751
      UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
752 753
    }

754
  if (fd == -1)
Jim Blandy's avatar
Jim Blandy committed
755
    {
Jim Blandy's avatar
Jim Blandy committed
756
      if (NILP (noerror))
757 758
	Fsignal (Qfile_error, Fcons (build_string ("Cannot open load file"),
				     Fcons (file, Qnil)));
Jim Blandy's avatar
Jim Blandy committed
759 760 761 762
      else
	return Qnil;
    }

763
  /* Tell startup.el whether or not we found the user's init file.  */
Karl Heuer's avatar
Karl Heuer committed
764 765 766
  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

767 768
  /* If FD is -2, that means openp found a magic file.  */
  if (fd == -2)
769
    {
770 771 772 773 774 775 776 777 778
      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);
779 780
    }

781 782 783 784 785 786 787 788 789 790
  /* 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.  */
791 792 793 794 795 796 797 798 799 800 801 802
  {
    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)
      Fsignal (Qerror, Fcons (build_string ("Recursive load"),
			      Fcons (found, Vloads_in_progress)));
    record_unwind_protect (record_load_unwind, Vloads_in_progress);
    Vloads_in_progress = Fcons (found, Vloads_in_progress);
  }
803

804
  if (!bcmp (SDATA (found) + SBYTES (found) - 4,
805 806 807
	     ".elc", 4))
    /* Load .elc files directly, but not when they are
       remote and have no handler!  */
Jim Blandy's avatar
Jim Blandy committed
808
    {
809
      if (fd != -2)
810
	{
811 812
	  struct stat s1, s2;
	  int result;
813

814 815 816 817
	  if (!safe_to_load_p (fd))
	    {
	      safe_p = 0;
	      if (!load_dangerous_libraries)
818 819 820 821 822 823
		{
		  if (fd >= 0)
		    emacs_close (fd);
		  error ("File `%s' was not compiled in Emacs",
			 SDATA (found));
		}
824 825 826
	      else if (!NILP (nomessage))
		message_with_string ("File `%s' not compiled in Emacs", found, 1);
	    }
827

828 829
	  compiled = 1;

830 831 832
	  GCPRO1 (efound);
	  efound = ENCODE_FILE (found);

Dave Love's avatar
Dave Love committed
833
#ifdef DOS_NT
834
	  fmode = "rb";
Dave Love's avatar
Dave Love committed
835
#endif /* DOS_NT */
836
	  stat ((char *)SDATA (efound), &s1);
837
	  SSET (efound, SBYTES (efound) - 1, 0);
838
	  result = stat ((char *)SDATA (efound), &s2);
839
	  SSET (efound, SBYTES (efound) - 1, 'c');
840 841
	  UNGCPRO;

842 843 844 845
	  if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
	    {
	      /* Make the progress messages mention that source is newer.  */
	      newer = 1;
846

847
	      /* If we won't print another message, mention this anyway.  */
848 849 850 851 852
	      if (!NILP (nomessage))
		{
		  Lisp_Object file;
		  file = Fsubstring (found, make_number (0), make_number (-1));
		  message_with_string ("Source file `%s' newer than byte-compiled file",
853
				       file, 1);
854
		}
855
	    }
856
	}
Jim Blandy's avatar
Jim Blandy committed
857
    }
Karl Heuer's avatar
Karl Heuer committed
858 859 860 861 862
  else
    {
      /* We are loading a source file (*.el).  */
      if (!NILP (Vload_source_file_function))
	{
863
	  Lisp_Object val;
864 865

	  if (fd >= 0)
866
	    emacs_close (fd);
867 868 869 870
	  val = call4 (Vload_source_file_function, found, file,
		       NILP (noerror) ? Qnil : Qt,
		       NILP (nomessage) ? Qnil : Qt);
	  return unbind_to (count, val);
Karl Heuer's avatar
Karl Heuer committed
871 872
	}
    }
Jim Blandy's avatar
Jim Blandy committed
873

874
#ifdef WINDOWSNT
875
  emacs_close (fd);
876 877
  GCPRO1 (efound);
  efound = ENCODE_FILE (found);
878
  stream = fopen ((char *) SDATA (efound), fmode);
879
  UNGCPRO;
880 881 882
#else  /* not WINDOWSNT */
  stream = fdopen (fd, fmode);
#endif /* not WINDOWSNT */
Jim Blandy's avatar
Jim Blandy committed
883 884
  if (stream == 0)
    {
885
      emacs_close (fd);
886
      error ("Failure to create stdio stream for %s", SDATA (file));
Jim Blandy's avatar
Jim Blandy committed
887 888
    }

889 890 891
  if (! NILP (Vpurify_flag))
    Vpreloaded_file_list = Fcons (file, Vpreloaded_file_list);

892 893
  if (NILP (nomessage))
    {
894 895 896 897
      if (!safe_p)
	message_with_string ("Loading %s (compiled; note unsafe, not compiled in Emacs)...",
		 file, 1);
      else if (!compiled)
898
	message_with_string ("Loading %s (source)...", file, 1);
899
      else if (newer)
900 901
	message_with_string ("Loading %s (compiled; note, source file is newer)...",
		 file, 1);
902
      else /* The typical case; compiled file newer than source file.  */
903
	message_with_string ("Loading %s...", file, 1);
904
    }
Jim Blandy's avatar
Jim Blandy committed
905

906
  GCPRO1 (file);
907
  record_unwind_protect (load_unwind, make_save_value (stream, 0));
908
  record_unwind_protect (load_descriptor_unwind, load_descriptor_list);
909
  specbind (Qload_file_name, found);
910
  specbind (Qinhibit_file_name_operation, Qnil);
911 912
  load_descriptor_list
    = Fcons (make_number (fileno (stream)), load_descriptor_list);
Jim Blandy's avatar
Jim Blandy committed
913
  load_in_progress++;
914 915
  readevalloop (Qget_file_char, stream, file, Feval,
		0, Qnil, Qnil, Qnil, Qnil);
Jim Blandy's avatar
Jim Blandy committed
916 917 918
  unbind_to (count, Qnil);

  /* Run any load-hooks for this file.  */
919
  temp = Fassoc (file, Vafter_load_alist);
Jim Blandy's avatar
Jim Blandy committed
920
  if (!NILP (temp))
Jim Blandy's avatar
Jim Blandy committed
921 922 923
    Fprogn (Fcdr (temp));
  UNGCPRO;

924 925 926 927 928
  if (saved_doc_string)
    free (saved_doc_string);
  saved_doc_string = 0;
  saved_doc_string_size = 0;

929
  if (prev_saved_doc_string)
930
    xfree (prev_saved_doc_string);
931 932 933
  prev_saved_doc_string = 0;
  prev_saved_doc_string_size = 0;

Jim Blandy's avatar
Jim Blandy committed
934
  if (!noninteractive && NILP (nomessage))
935
    {
936 937 938 939
      if (!safe_p)
	message_with_string ("Loading %s (compiled; note unsafe, not compiled in Emacs)...done",
		 file, 1);
      else if (!compiled)
940
	message_with_string ("Loading %s (source)...done", file, 1);
941
      else if (newer)
942 943
	message_with_string ("Loading %s (compiled; note, source file is newer)...done",
		 file, 1);
944
      else /* The typical case; compiled file newer than source file.  */
945
	message_with_string ("Loading %s...done", file, 1);
946
    }
947

948 949 950 951 952
  if (!NILP (Fequal (build_string ("obsolete"),
		     Ffile_name_nondirectory
		     (Fdirectory_file_name (Ffile_name_directory (found))))))
    message_with_string ("Package %s is obsolete", file, 1);

Jim Blandy's avatar
Jim Blandy committed
953 954 955 956
  return Qt;
}

static Lisp_Object
957 958
load_unwind (arg)  /* used as unwind-protect function in load */
     Lisp_Object arg;
Jim Blandy's avatar
Jim Blandy committed
959
{
960 961 962
  FILE *stream = (FILE *) XSAVE_VALUE (arg)->pointer;
  if (stream != NULL)
    fclose (stream);
Jim Blandy's avatar
Jim Blandy committed
963 964 965 966
  if (--load_in_progress < 0) load_in_progress = 0;
  return Qnil;
}

967 968 969 970 971
static Lisp_Object
load_descriptor_unwind (oldlist)
     Lisp_Object oldlist;
{
  load_descriptor_list = oldlist;
972
  return Qnil;
973 974 975 976 977 978 979 980
}

/* Close all descriptors in use for Floads.
   This is used when starting a subprocess.  */

void
close_load_descs ()
{
981
#ifndef WINDOWSNT
982
  Lisp_Object tail;
983
  for (tail = load_descriptor_list; !NILP (tail); tail = XCDR (tail))
984
    emacs_close (XFASTINT (XCAR (tail)));
985
#endif