lread.c 92.5 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* Lisp parsing and input streams.
Richard M. Stallman's avatar
Richard M. Stallman committed
2
   Copyright (C) 1985, 86, 87, 88, 89, 93, 94, 95, 97, 1998
3
      Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
4 5 6 7 8

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
9
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
10 11 12 13 14 15 16 17 18
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
19 20
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
21 22


Richard M. Stallman's avatar
Richard M. Stallman committed
23
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
24 25 26 27
#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/file.h>
28
#include <errno.h>
Jim Blandy's avatar
Jim Blandy committed
29 30 31 32
#include "lisp.h"

#ifndef standalone
#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"
Jim Blandy's avatar
Jim Blandy committed
38 39 40 41 42 43
#endif

#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
#ifndef X_OK
#define X_OK 01
#endif

#ifdef LISP_FLOAT_TYPE
60 61 62
#ifdef STDC_HEADERS
#include <stdlib.h>
#endif
63

Jim Blandy's avatar
Jim Blandy committed
64 65 66
#include <math.h>
#endif /* LISP_FLOAT_TYPE */

Richard M. Stallman's avatar
Richard M. Stallman committed
67 68 69 70
#ifdef HAVE_SETLOCALE
#include <locale.h>
#endif /* HAVE_SETLOCALE */

Richard M. Stallman's avatar
Richard M. Stallman committed
71 72 73 74
#ifndef O_RDONLY
#define O_RDONLY 0
#endif

75 76
extern int errno;

77
Lisp_Object Qread_char, Qget_file_char, Qstandard_input, Qcurrent_load_list;
Jim Blandy's avatar
Jim Blandy committed
78
Lisp_Object Qvariable_documentation, Vvalues, Vstandard_input, Vafter_load_alist;
79
Lisp_Object Qascii_character, Qload, Qload_file_name;
80
Lisp_Object Qbackquote, Qcomma, Qcomma_at, Qcomma_dot, Qfunction;
81
Lisp_Object Qinhibit_file_name_operation;
82 83

extern Lisp_Object Qevent_symbol_element_mask;
84
extern Lisp_Object Qfile_exists_p;
Jim Blandy's avatar
Jim Blandy committed
85 86 87 88

/* non-zero if inside `load' */
int load_in_progress;

89 90 91
/* Directory in which the sources were found.  */
Lisp_Object Vsource_directory;

Jim Blandy's avatar
Jim Blandy committed
92 93 94
/* Search path for files to be loaded. */
Lisp_Object Vload_path;

Karl Heuer's avatar
Karl Heuer committed
95 96 97
/* File name of user's init file.  */
Lisp_Object Vuser_init_file;

98 99 100 101
/* This is the user-visible association list that maps features to
   lists of defs in their load files. */
Lisp_Object Vload_history;

102
/* This is used to build the load history. */
103 104
Lisp_Object Vcurrent_load_list;

105 106 107
/* List of files that were preloaded.  */
Lisp_Object Vpreloaded_file_list;

108 109 110
/* Name of file actually being read by `load'.  */
Lisp_Object Vload_file_name;

111 112 113
/* Function to use for reading, in `load' and friends.  */
Lisp_Object Vload_read_function;

114 115 116 117 118 119
/* 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;

120 121 122
/* Nonzero means load should forcibly load all dynamic doc strings.  */
static int load_force_doc_strings;

123 124 125
/* Nonzero means read should convert strings to unibyte.  */
static int load_convert_to_unibyte;

Karl Heuer's avatar
Karl Heuer committed
126 127 128 129
/* Function to use for loading an Emacs lisp source file (not
   compiled) instead of readevalloop.  */
Lisp_Object Vload_source_file_function;

130 131 132
/* List of descriptors now open for Fload.  */
static Lisp_Object load_descriptor_list;

133
/* File for get_file_char to read from.  Use by load.  */
Jim Blandy's avatar
Jim Blandy committed
134 135 136 137 138
static FILE *instream;

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

139
/* For use within read-from-string (this reader is non-reentrant!!)  */
Jim Blandy's avatar
Jim Blandy committed
140
static int read_from_string_index;
141
static int read_from_string_index_byte;
Jim Blandy's avatar
Jim Blandy committed
142
static int read_from_string_limit;
143

144 145 146 147
/* Number of bytes left to read in the buffer character
   that `readchar' has already advanced over.  */
static int readchar_backlog;

148
/* This contains the last string skipped with #@.  */
149 150 151 152 153 154 155 156
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.  */
static int saved_doc_string_position;

157 158 159 160 161 162 163 164 165 166 167
/* 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.  */
static int prev_saved_doc_string_position;

168 169 170 171 172
/* 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;
Jim Blandy's avatar
Jim Blandy committed
173 174 175

/* Handle unreading and rereading of characters.
   Write READCHAR to read a character,
Karl Heuer's avatar
Karl Heuer committed
176 177 178 179 180
   UNREAD(c) to unread c to be read again.

   These macros actually read/unread a byte code, multibyte characters
   are not handled here.  The caller should manage them if necessary.
 */
Jim Blandy's avatar
Jim Blandy committed
181 182 183 184 185 186 187 188 189 190 191

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

static int
readchar (readcharfun)
     Lisp_Object readcharfun;
{
  Lisp_Object tem;
  register int c, mpos;

192
  if (BUFFERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
193
    {
194
      register struct buffer *inbuffer = XBUFFER (readcharfun);
Jim Blandy's avatar
Jim Blandy committed
195

196 197
      int pt_byte = BUF_PT_BYTE (inbuffer);
      int orig_pt_byte = pt_byte;
198

199 200 201 202 203 204 205 206
      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);

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

210 211
      readchar_backlog = -1;

212 213
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
214 215 216 217 218
	  unsigned char workbuf[4];
	  unsigned char *str = workbuf;
	  int length;

	  /* Fetch the character code from the buffer.  */
219 220 221
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, pt_byte);
	  BUF_INC_POS (inbuffer, pt_byte);
	  c = STRING_CHAR (p, pt_byte - orig_pt_byte);
222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238

	  /* Find the byte-sequence representation of that character.  */
	  if (SINGLE_BYTE_CHAR_P (c))
	    length = 1, workbuf[0] = c;
	  else
	    length = non_ascii_char_to_string (c, workbuf, &str);

	  /* If the bytes for this character in the buffer
	     are not identical with what the character code implies,
	     read the bytes one by one from the buffer.  */
	  if (length != pt_byte - orig_pt_byte
	      || (length == 1 ? *str != *p : bcmp (str, p, length)))
	    {
	      readchar_backlog = pt_byte - orig_pt_byte;
	      c = BUF_FETCH_BYTE (inbuffer, orig_pt_byte);
	      readchar_backlog--;
	    }
239 240 241 242 243
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, pt_byte);
	  pt_byte++;
244
	}
245
      SET_BUF_PT_BOTH (inbuffer, BUF_PT (inbuffer) + 1, pt_byte);
246

247
      return c;
Jim Blandy's avatar
Jim Blandy committed
248
    }
249
  if (MARKERP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
250
    {
251
      register struct buffer *inbuffer = XMARKER (readcharfun)->buffer;
Jim Blandy's avatar
Jim Blandy committed
252

253 254
      int bytepos = marker_byte_position (readcharfun);
      int orig_bytepos = bytepos;
255

256 257 258 259 260 261 262 263
      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);

264 265
      if (bytepos >= BUF_ZV_BYTE (inbuffer))
	return -1;
266

267 268
      readchar_backlog = -1;

269 270
      if (! NILP (inbuffer->enable_multibyte_characters))
	{
271 272 273 274 275
	  unsigned char workbuf[4];
	  unsigned char *str = workbuf;
	  int length;

	  /* Fetch the character code from the buffer.  */
276 277 278
	  unsigned char *p = BUF_BYTE_ADDRESS (inbuffer, bytepos);
	  BUF_INC_POS (inbuffer, bytepos);
	  c = STRING_CHAR (p, bytepos - orig_bytepos);
279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295

	  /* Find the byte-sequence representation of that character.  */
	  if (SINGLE_BYTE_CHAR_P (c))
	    length = 1, workbuf[0] = c;
	  else
	    length = non_ascii_char_to_string (c, workbuf, &str);

	  /* If the bytes for this character in the buffer
	     are not identical with what the character code implies,
	     read the bytes one by one from the buffer.  */
	  if (length != bytepos - orig_bytepos
	      || (length == 1 ? *str != *p : bcmp (str, p, length)))
	    {
	      readchar_backlog = bytepos - orig_bytepos;
	      c = BUF_FETCH_BYTE (inbuffer, orig_bytepos);
	      readchar_backlog--;
	    }
296 297 298 299 300
	}
      else
	{
	  c = BUF_FETCH_BYTE (inbuffer, bytepos);
	  bytepos++;
301 302
	}

303 304 305 306
      XMARKER (readcharfun)->bytepos = bytepos;
      XMARKER (readcharfun)->charpos++;

      return c;
Jim Blandy's avatar
Jim Blandy committed
307
    }
308 309 310 311

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

Jim Blandy's avatar
Jim Blandy committed
312
  if (EQ (readcharfun, Qget_file_char))
313 314 315 316 317 318 319 320 321 322 323 324
    {
      c = getc (instream);
#ifdef EINTR
      /* Interrupted reads have been observed while reading over the network */
      while (c == EOF && ferror (instream) && errno == EINTR)
	{
	  clearerr (instream);
	  c = getc (instream);
	}
#endif
      return c;
    }
Jim Blandy's avatar
Jim Blandy committed
325

326
  if (STRINGP (readcharfun))
Jim Blandy's avatar
Jim Blandy committed
327
    {
328
      if (read_from_string_index >= read_from_string_limit)
Jim Blandy's avatar
Jim Blandy committed
329
	c = -1;
330 331 332 333 334 335
      else if (STRING_MULTIBYTE (readcharfun))
	FETCH_STRING_CHAR_ADVANCE (c, readcharfun,
				   read_from_string_index,
				   read_from_string_index_byte);
      else
	c = XSTRING (readcharfun)->data[read_from_string_index++];
336

Jim Blandy's avatar
Jim Blandy committed
337 338 339 340 341
      return c;
    }

  tem = call0 (readcharfun);

Jim Blandy's avatar
Jim Blandy committed
342
  if (NILP (tem))
Jim Blandy's avatar
Jim Blandy committed
343 344 345 346 347 348 349 350 351 352 353 354
    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;
{
355 356 357 358
  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.  */
    ;
359
  else if (BUFFERP (readcharfun))
360
    {
361 362
      struct buffer *b = XBUFFER (readcharfun);
      int bytepos = BUF_PT_BYTE (b);
363

364 365
      if (readchar_backlog >= 0)
	readchar_backlog++;
366
      else
367 368 369 370 371 372
	{
	  BUF_PT (b)--;
	  if (! NILP (b->enable_multibyte_characters))
	    BUF_DEC_POS (b, bytepos);
	  else
	    bytepos--;
373

374 375
	  BUF_PT_BYTE (b) = bytepos;
	}
376
    }
377
  else if (MARKERP (readcharfun))
378
    {
379 380
      struct buffer *b = XMARKER (readcharfun)->buffer;
      int bytepos = XMARKER (readcharfun)->bytepos;
381

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

392 393
	  XMARKER (readcharfun)->bytepos = bytepos;
	}
394
    }
395
  else if (STRINGP (readcharfun))
396 397 398 399 400
    {
      read_from_string_index--;
      read_from_string_index_byte
	= string_char_to_byte (readcharfun, read_from_string_index);
    }
401 402
  else if (EQ (readcharfun, Qlambda))
    read_bytecode_char (1);
Jim Blandy's avatar
Jim Blandy committed
403 404 405 406 407 408 409
  else if (EQ (readcharfun, Qget_file_char))
    ungetc (c, instream);
  else
    call1 (readcharfun, make_number (c));
}

static Lisp_Object read0 (), read1 (), read_list (), read_vector ();
410
static int read_multibyte ();
411 412 413
static Lisp_Object substitute_object_recurse ();
static void        substitute_object_in_subtree (), substitute_in_interval ();

Jim Blandy's avatar
Jim Blandy committed
414

415
/* Get a character from the tty.  */
Jim Blandy's avatar
Jim Blandy committed
416

417 418
extern Lisp_Object read_char ();

419 420 421 422 423 424 425 426 427 428 429 430 431
/* 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
432 433 434 435
   character.

   If INPUT_METHOD is nonzero, we invoke the current input method
   if the character warrants that.  */
436

437
Lisp_Object
438 439 440
read_filtered_event (no_switch_frame, ascii_required, error_nonascii,
		     input_method)
     int no_switch_frame, ascii_required, error_nonascii, input_method;
441 442 443 444
{
#ifdef standalone
  return make_number (getchar ());
#else
445 446 447
  register Lisp_Object val, delayed_switch_frame;

  delayed_switch_frame = Qnil;
448 449 450

  /* Read until we get an acceptable event.  */
 retry:
451 452 453
  val = read_char (0, 0, 0,
		   (input_method ? Qnil : Qt),
		   0);
454

455
  if (BUFFERP (val))
456 457
    goto retry;

458
  /* switch-frame events are put off until after the next ASCII
Karl Heuer's avatar
Karl Heuer committed
459
     character.  This is better than signaling an error just because
460 461 462 463 464 465 466 467 468 469 470 471 472 473
     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.  */
474
      if (SYMBOLP (val))
475 476 477 478 479 480 481 482 483
	{
	  Lisp_Object tem, tem1, tem2;
	  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))
484
		XSETFASTINT (val, XINT (tem1) | XINT (Fcar (Fcdr (tem))));
485 486 487 488
	    }
	}
	  
      /* If we don't have a character now, deal with it appropriately.  */
489
      if (!INTEGERP (val))
490 491 492
	{
	  if (error_nonascii)
	    {
493
	      Vunread_command_events = Fcons (val, Qnil);
494 495 496 497 498 499 500 501 502 503 504 505 506 507
	      error ("Non-character input-event");
	    }
	  else
	    goto retry;
	}
    }

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

  return val;
#endif
}

508
DEFUN ("read-char", Fread_char, Sread_char, 0, 2, 0,
Jim Blandy's avatar
Jim Blandy committed
509
  "Read a character from the command input (keyboard or macro).\n\
Jim Blandy's avatar
Jim Blandy committed
510 511
It is returned as a number.\n\
If the user generates an event which is not a character (i.e. a mouse\n\
Jim Blandy's avatar
Jim Blandy committed
512 513 514 515
click or function key event), `read-char' signals an error.  As an\n\
exception, switch-frame events are put off until non-ASCII events can\n\
be read.\n\
If you want to read non-character events, or ignore them, call\n\
516 517 518
`read-event' or `read-char-exclusive' instead.\n\
\n\
If the optional argument PROMPT is non-nil, display that as a prompt.\n\
519 520 521 522 523
If the optional argument INHERIT-INPUT-METHOD is non-nil and some\n\
input method is turned on in the current buffer, that input method\n\
is used for reading a character.")
  (prompt, inherit_input_method)
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
524
{
525 526
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
527
  return read_filtered_event (1, 1, 1, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
528 529
}

530 531 532
DEFUN ("read-event", Fread_event, Sread_event, 0, 2, 0,
  "Read an event object from the input stream.\n\
If the optional argument PROMPT is non-nil, display that as a prompt.\n\
533 534 535 536 537
If the optional argument INHERIT-INPUT-METHOD is non-nil and some\n\
input method is turned on in the current buffer, that input method\n\
is used for reading a character.")
  (prompt, inherit_input_method)
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
538
{
539 540
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
541
  return read_filtered_event (0, 0, 0, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
542 543
}

544
DEFUN ("read-char-exclusive", Fread_char_exclusive, Sread_char_exclusive, 0, 2, 0,
Jim Blandy's avatar
Jim Blandy committed
545
  "Read a character from the command input (keyboard or macro).\n\
546 547 548
It is returned as a number.  Non-character events are ignored.\n\
\n\
If the optional argument PROMPT is non-nil, display that as a prompt.\n\
549 550 551 552 553
If the optional argument INHERIT-INPUT-METHOD is non-nil and some\n\
input method is turned on in the current buffer, that input method\n\
is used for reading a character.")
  (prompt, inherit_input_method)
     Lisp_Object prompt, inherit_input_method;
Jim Blandy's avatar
Jim Blandy committed
554
{
555 556
  if (! NILP (prompt))
    message_with_string ("%s", prompt, 0);
557
  return read_filtered_event (1, 1, 0, ! NILP (inherit_input_method));
Jim Blandy's avatar
Jim Blandy committed
558 559 560 561 562 563 564
}

DEFUN ("get-file-char", Fget_file_char, Sget_file_char, 0, 0, 0,
  "Don't use this yourself.")
  ()
{
  register Lisp_Object val;
565
  XSETINT (val, getc (instream));
Jim Blandy's avatar
Jim Blandy committed
566 567 568 569 570
  return val;
}

static void readevalloop ();
static Lisp_Object load_unwind ();
571
static Lisp_Object load_descriptor_unwind ();
Jim Blandy's avatar
Jim Blandy committed
572

573
DEFUN ("load", Fload, Sload, 1, 5, 0,
Jim Blandy's avatar
Jim Blandy committed
574 575 576 577 578 579 580 581 582 583
  "Execute a file of Lisp code named FILE.\n\
First try FILE with `.elc' appended, then try with `.el',\n\
 then try FILE unmodified.\n\
This function searches the directories in `load-path'.\n\
If optional second arg NOERROR is non-nil,\n\
 report no error if FILE doesn't exist.\n\
Print messages at start and end of loading unless\n\
 optional third arg NOMESSAGE is non-nil.\n\
If optional fourth arg NOSUFFIX is non-nil, don't try adding\n\
 suffixes `.elc' or `.el' to the specified name FILE.\n\
584
If optional fifth arg MUST-SUFFIX is non-nil, insist on\n\
Richard M. Stallman's avatar
Richard M. Stallman committed
585
 the suffix `.elc' or `.el'; don't accept just FILE unless\n\
586
 it ends in one of those suffixes or includes a directory name.\n\
Jim Blandy's avatar
Jim Blandy committed
587
Return t if file exists.")
588 589
  (file, noerror, nomessage, nosuffix, must_suffix)
     Lisp_Object file, noerror, nomessage, nosuffix, must_suffix;
Jim Blandy's avatar
Jim Blandy committed
590 591 592 593 594 595 596 597
{
  register FILE *stream;
  register int fd = -1;
  register Lisp_Object lispstream;
  int count = specpdl_ptr - specpdl;
  Lisp_Object temp;
  struct gcpro gcpro1;
  Lisp_Object found;
598 599 600 601
  /* 1 means we printed the ".el is newer" message.  */
  int newer = 0;
  /* 1 means we are loading a compiled file.  */
  int compiled = 0;
602
  Lisp_Object handler;
603
  char *fmode = "r";
604
#ifdef DOS_NT
605
  fmode = "rt";
606
#endif /* DOS_NT */
Jim Blandy's avatar
Jim Blandy committed
607

608
  CHECK_STRING (file, 0);
Jim Blandy's avatar
Jim Blandy committed
609

610
  /* If file name is magic, call the handler.  */
611
  handler = Ffind_file_name_handler (file, Qload);
612
  if (!NILP (handler))
613
    return call5 (handler, Qload, file, noerror, nomessage, nosuffix);
614

615 616 617
  /* Do this after the handler to avoid
     the need to gcpro noerror, nomessage and nosuffix.
     (Below here, we care only whether they are nil or not.)  */
618
  file = Fsubstitute_in_file_name (file);
619

Jim Blandy's avatar
Jim Blandy committed
620 621
  /* Avoid weird lossage with null string as arg,
     since it would try to load a directory as a Lisp file */
622
  if (XSTRING (file)->size > 0)
Jim Blandy's avatar
Jim Blandy committed
623
    {
624 625
      int size = XSTRING (file)->size;

626
      GCPRO1 (file);
627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642

      if (! NILP (must_suffix))
	{
	  /* Don't insist on adding a suffix if FILE already ends with one.  */
	  if (size > 3
	      && !strcmp (XSTRING (file)->data + size - 3, ".el"))
	    must_suffix = Qnil;
	  else if (size > 4
		   && !strcmp (XSTRING (file)->data + size - 4, ".elc"))
	    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;
	}

643 644 645 646
      fd = openp (Vload_path, file,
		  (!NILP (nosuffix) ? ""
		   : ! NILP (must_suffix) ? ".elc:.el"
		   : ".elc:.el:"),
Jim Blandy's avatar
Jim Blandy committed
647
		  &found, 0);
648
      UNGCPRO;
Jim Blandy's avatar
Jim Blandy committed
649 650 651 652
    }

  if (fd < 0)
    {
Jim Blandy's avatar
Jim Blandy committed
653
      if (NILP (noerror))
Jim Blandy's avatar
Jim Blandy committed
654 655
	while (1)
	  Fsignal (Qfile_error, Fcons (build_string ("Cannot open load file"),
656
				       Fcons (file, Qnil)));
Jim Blandy's avatar
Jim Blandy committed
657 658 659 660
      else
	return Qnil;
    }

Karl Heuer's avatar
Karl Heuer committed
661 662 663
  if (EQ (Qt, Vuser_init_file))
    Vuser_init_file = found;

664
  /* If FD is 0, that means openp found a magic file.  */
665 666
  if (fd == 0)
    {
667 668 669 670 671 672 673 674 675
      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);
676 677
    }

678 679
  /* Load .elc files directly, but not when they are
     remote and have no handler!  */
Jim Blandy's avatar
Jim Blandy committed
680
  if (!bcmp (&(XSTRING (found)->data[XSTRING (found)->size - 4]),
681 682
	     ".elc", 4)
      && fd != 0)
Jim Blandy's avatar
Jim Blandy committed
683 684 685 686
    {
      struct stat s1, s2;
      int result;

687 688
      compiled = 1;

689
#ifdef DOS_NT
690
      fmode = "rb";
691
#endif /* DOS_NT */
692
      stat ((char *)XSTRING (found)->data, &s1);
Jim Blandy's avatar
Jim Blandy committed
693
      XSTRING (found)->data[XSTRING (found)->size - 1] = 0;
694
      result = stat ((char *)XSTRING (found)->data, &s2);
Jim Blandy's avatar
Jim Blandy committed
695
      if (result >= 0 && (unsigned) s1.st_mtime < (unsigned) s2.st_mtime)
696
	{
697 698 699 700 701
	  /* Make the progress messages mention that source is newer.  */
	  newer = 1;

	  /* If we won't print another message, mention this anyway.  */
	  if (! NILP (nomessage))
702 703
	    message_with_string ("Source file `%s' newer than byte-compiled file",
				 found, 1);
704
	}
Jim Blandy's avatar
Jim Blandy committed
705 706
      XSTRING (found)->data[XSTRING (found)->size - 1] = 'c';
    }
Karl Heuer's avatar
Karl Heuer committed
707 708 709 710 711
  else
    {
      /* We are loading a source file (*.el).  */
      if (!NILP (Vload_source_file_function))
	{
712 713
	  if (fd != 0)
	    close (fd);
714
	  return call4 (Vload_source_file_function, found, file,
Karl Heuer's avatar
Karl Heuer committed
715 716 717 718
			NILP (noerror) ? Qnil : Qt,
			NILP (nomessage) ? Qnil : Qt);
	}
    }
Jim Blandy's avatar
Jim Blandy committed
719

720
#ifdef WINDOWSNT
721
  close (fd);
722 723 724 725
  stream = fopen ((char *) XSTRING (found)->data, fmode);
#else  /* not WINDOWSNT */
  stream = fdopen (fd, fmode);
#endif /* not WINDOWSNT */
Jim Blandy's avatar
Jim Blandy committed
726 727 728
  if (stream == 0)
    {
      close (fd);
729
      error ("Failure to create stdio stream for %s", XSTRING (file)->data);
Jim Blandy's avatar
Jim Blandy committed
730 731
    }

732 733 734
  if (! NILP (Vpurify_flag))
    Vpreloaded_file_list = Fcons (file, Vpreloaded_file_list);

735 736
  if (NILP (nomessage))
    {
737
      if (!compiled)
738
	message_with_string ("Loading %s (source)...", file, 1);
739
      else if (newer)
740 741
	message_with_string ("Loading %s (compiled; note, source file is newer)...",
		 file, 1);
742
      else /* The typical case; compiled file newer than source file.  */
743
	message_with_string ("Loading %s...", file, 1);
744
    }
Jim Blandy's avatar
Jim Blandy committed
745

746
  GCPRO1 (file);
747 748 749
  lispstream = Fcons (Qnil, Qnil);
  XSETFASTINT (XCONS (lispstream)->car, (EMACS_UINT)stream >> 16);
  XSETFASTINT (XCONS (lispstream)->cdr, (EMACS_UINT)stream & 0xffff);
Jim Blandy's avatar
Jim Blandy committed
750
  record_unwind_protect (load_unwind, lispstream);
751
  record_unwind_protect (load_descriptor_unwind, load_descriptor_list);
752
  specbind (Qload_file_name, found);
753
  specbind (Qinhibit_file_name_operation, Qnil);
754 755
  load_descriptor_list
    = Fcons (make_number (fileno (stream)), load_descriptor_list);
Jim Blandy's avatar
Jim Blandy committed
756
  load_in_progress++;
757
  readevalloop (Qget_file_char, stream, file, Feval, 0, Qnil, Qnil);
Jim Blandy's avatar
Jim Blandy committed
758 759 760
  unbind_to (count, Qnil);

  /* Run any load-hooks for this file.  */
761
  temp = Fassoc (file, Vafter_load_alist);
Jim Blandy's avatar
Jim Blandy committed
762
  if (!NILP (temp))
Jim Blandy's avatar
Jim Blandy committed
763 764 765
    Fprogn (Fcdr (temp));
  UNGCPRO;

766 767 768 769 770
  if (saved_doc_string)
    free (saved_doc_string);
  saved_doc_string = 0;
  saved_doc_string_size = 0;

771 772 773 774 775
  if (prev_saved_doc_string)
    free (prev_saved_doc_string);
  prev_saved_doc_string = 0;
  prev_saved_doc_string_size = 0;

Jim Blandy's avatar
Jim Blandy committed
776
  if (!noninteractive && NILP (nomessage))
777
    {
778
      if (!compiled)
779
	message_with_string ("Loading %s (source)...done", file, 1);
780
      else if (newer)
781 782
	message_with_string ("Loading %s (compiled; note, source file is newer)...done",
		 file, 1);
783
      else /* The typical case; compiled file newer than source file.  */
784
	message_with_string ("Loading %s...done", file, 1);
785
    }
Jim Blandy's avatar
Jim Blandy committed
786 787 788 789 790 791 792
  return Qt;
}

static Lisp_Object
load_unwind (stream)  /* used as unwind-protect function in load */
     Lisp_Object stream;
{
793 794
  fclose ((FILE *) (XFASTINT (XCONS (stream)->car) << 16
		    | XFASTINT (XCONS (stream)->cdr)));
Jim Blandy's avatar
Jim Blandy committed
795 796 797 798
  if (--load_in_progress < 0) load_in_progress = 0;
  return Qnil;
}

799 800 801 802 803
static Lisp_Object
load_descriptor_unwind (oldlist)
     Lisp_Object oldlist;
{
  load_descriptor_list = oldlist;
804
  return Qnil;
805 806 807 808 809 810 811 812
}

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

void
close_load_descs ()
{
813
#ifndef WINDOWSNT
814 815 816
  Lisp_Object tail;
  for (tail = load_descriptor_list; !NILP (tail); tail = XCONS (tail)->cdr)
    close (XFASTINT (XCONS (tail)->car));
817
#endif
818
}
Jim Blandy's avatar
Jim Blandy committed
819 820 821 822 823 824

static int
complete_filename_p (pathname)
     Lisp_Object pathname;
{
  register unsigned char *s = XSTRING (pathname)->data;
825 826 827
  return (IS_DIRECTORY_SEP (s[0])
	  || (XSTRING (pathname)->size > 2
	      && IS_DEVICE_SEP (s[1]) && IS_DIRECTORY_SEP (s[2]))
Jim Blandy's avatar
Jim Blandy committed
828 829 830 831 832 833 834 835 836 837 838 839 840 841 842 843 844 845 846 847
#ifdef ALTOS
	  || *s == '@'
#endif
#ifdef VMS
	  || index (s, ':')
#endif /* VMS */
	  );
}

/* Search for a file whose name is STR, looking in directories
   in the Lisp list PATH, and trying suffixes from SUFFIX.
   SUFFIX is a string containing possible suffixes separated by colons.
   On success, returns a file descriptor.  On failure, returns -1.

   EXEC_ONLY nonzero means don't open the files,
   just look for one that is executable.  In this case,
   returns 1 on success.

   If STOREPTR is nonzero, it points to a slot where the name of
   the file actually found should be stored as a Lisp string.
848 849 850 851 852
   nil is stored there on failure.

   If the file we find is remote, return 0
   but store the found remote file name in *STOREPTR.
   We do not check for remote files if EXEC_ONLY is nonzero.  */
Jim Blandy's avatar
Jim Blandy committed
853 854 855 856 857 858 859 860 861 862 863 864 865 866

int
openp (path, str, suffix, storeptr, exec_only)
     Lisp_Object path, str;
     char *suffix;
     Lisp_Object *storeptr;
     int exec_only;
{
  register int fd;
  int fn_size = 100;
  char buf[100];
  register char *fn = buf;
  int absolute = 0;
  int want_size;
867
  Lisp_Object filename;
Jim Blandy's avatar
Jim Blandy committed
868
  struct stat st;
869
  struct gcpro gcpro1;
Jim Blandy's avatar
Jim Blandy committed
870

871
  GCPRO1 (str);
Jim Blandy's avatar
Jim Blandy committed
872 873 874 875 876 877
  if (storeptr)
    *storeptr = Qnil;

  if (complete_filename_p (str))
    absolute = 1;

Jim Blandy's avatar
Jim Blandy committed
878
  for (; !NILP (path); path = Fcdr (path))
Jim Blandy's avatar
Jim Blandy committed
879 880 881 882 883 884 885 886 887 888 889 890 891 892 893 894 895 896 897 898 899 900 901 902 903 904 905 906
    {
      char *nsuffix;

      filename = Fexpand_file_name (str, Fcar (path));
      if (!complete_filename_p (filename))
	/* If there are non-absolute elts in PATH (eg ".") */
	/* Of course, this could conceivably lose if luser sets
	   default-directory to be something non-absolute... */
	{
	  filename = Fexpand_file_name (filename, current_buffer->directory);
	  if (!complete_filename_p (filename))
	    /* Give up on this path element! */
	    continue;
	}

      /* Calculate maximum size of any filename made from
	 this path element/specified file name and any possible suffix.  */
      want_size = strlen (suffix) + XSTRING (filename)->size + 1;
      if (fn_size < want_size)
	fn = (char *) alloca (fn_size = 100 + want_size);

      nsuffix = suffix;

      /* Loop over suffixes.  */
      while (1)
	{
	  char *esuffix = (char *) index (nsuffix, ':');
	  int lsuffix = esuffix ? esuffix - nsuffix : strlen (nsuffix);
907
	  Lisp_Object handler;
Jim Blandy's avatar
Jim Blandy committed
908

909 910 911 912 913 914 915 916 917 918 919 920 921 922 923 924
	  /* Concatenate path element/specified name with the suffix.
	     If the directory starts with /:, remove that.  */
	  if (XSTRING (filename)->size > 2
	      && XSTRING (filename)->data[0] == '/'
	      && XSTRING (filename)->data[1] == ':')
	    {
	      strncpy (fn, XSTRING (filename)->data + 2,
		       XSTRING (filename)->size - 2);
	      fn[XSTRING (filename)->size - 2] = 0;
	    }
	  else
	    {
	      strncpy (fn, XSTRING (filename)->data, XSTRING (filename)->size);
	      fn[XSTRING (filename)->size] = 0;
	    }

Jim Blandy's avatar
Jim Blandy committed
925 926 927
	  if (lsuffix != 0)  /* Bug happens on CCI if lsuffix is 0.  */
	    strncat (fn, nsuffix, lsuffix);

928 929 930 931 932 933
	  /* Check that the file exists and is not a directory.  */
	  if (absolute)
	    handler = Qnil;
	  else
	    handler = Ffind_file_name_handler (filename, Qfile_exists_p);
	  if (! NILP (handler) && ! exec_only)
Jim Blandy's avatar
Jim Blandy committed
934
	    {
935 936
	      Lisp_Object string;
	      int exists;
Jim Blandy's avatar
Jim Blandy committed
937

938 939 940 941 942 943 944 945
	      string = build_string (fn);
	      exists = ! NILP (exec_only ? Ffile_executable_p (string)
			       : Ffile_readable_p (string));
	      if (exists
		  && ! NILP (Ffile_directory_p (build_string (fn))))
		exists = 0;

	      if (exists)
Jim Blandy's avatar
Jim Blandy committed
946 947 948 949
		{
		  /* We succeeded; return this descriptor and filename.  */
		  if (storeptr)
		    *storeptr = build_string (fn);
950
		  UNGCPRO;
951 952 953 954 955 956 957 958 959 960 961 962 963 964 965 966 967 968 969 970 971 972 973
		  return 0;
		}
	    }
	  else
	    {
	      int exists = (stat (fn, &st) >= 0
			    && (st.st_mode & S_IFMT) != S_IFDIR);
	      if (exists)
		{
		  /* Check that we can access or open it.  */
		  if (exec_only)
		    fd = (access (fn, X_OK) == 0) ? 1 : -1;
		  else
		    fd = open (fn, O_RDONLY, 0);

		  if (fd >= 0)
		    {
		      /* We succeeded; return this descriptor and filename.  */
		      if (storeptr)
			*storeptr = build_string (fn);
		      UNGCPRO;
		      return fd;
		    }
Jim Blandy's avatar
Jim Blandy committed
974 975 976 977 978 979 980 981
		}
	    }

	  /* Advance to next suffix.  */
	  if (esuffix == 0)
	    break;
	  nsuffix += lsuffix + 1;
	}
982
      if (absolute)
983
	break;
Jim Blandy's avatar
Jim Blandy committed
984 985
    }

986 987
  UNGCPRO;
  return -1;
Jim Blandy's avatar
Jim Blandy committed
988 989 990
}


991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006 1007 1008 1009 1010 1011 1012 1013 1014 1015 1016 1017 1018 1019 1020 1021 1022 1023 1024 1025 1026 1027 1028 1029 1030 1031 1032 1033 1034 1035 1036 1037 1038 1039 1040 1041 1042 1043 1044 1045 1046 1047 1048 1049 1050
/* Merge the list we've accumulated of globals from the current input source
   into the load_history variable.  The details depend on whether
   the source has an associated file name or not. */

static void
build_load_history (stream, source)
     FILE *stream;
     Lisp_Object source;
{
  register Lisp_Object tail, prev, newelt;
  register Lisp_Object tem, tem2;
  register int foundit, loading;

  loading = stream || !NARROWED;

  tail = Vload_history;
  prev = Qnil;
  foundit = 0;
  while (!NILP (tail))
    {
      tem = Fcar (tail);

      /* Find the feature's previous assoc list... */
      if (!NILP (Fequal (source, Fcar (tem))))
	{
	  foundit = 1;

	  /*  If we're loading, remove it. */
	  if (loading)
	    {	  
	      if (NILP (prev))
		Vload_history = Fcdr (tail);
	      else
		Fsetcdr (prev, Fcdr (tail));
	    }

	  /*  Otherwise, cons on new symbols that are not already members.  */
	  else
	    {
	      tem2 = Vcurrent_load_list;

	      while (CONSP (tem2))
		{
		  newelt = Fcar (tem2);

		  if (NILP (Fmemq (newelt, tem)))
		    Fsetcar (tail, Fcons (Fcar (tem),
					  Fcons (newelt, Fcdr (tem))));

		  tem2 = Fcdr (tem2);
		  QUIT;
		}
	    }
	}
      else
	prev = tail;
      tail = Fcdr (tail);
      QUIT;
    }

1051 1052 1053 1054 1055 1056
  /* If we're loading, cons the new assoc onto the front of load-history,
     the most-recently-loaded position.  Also do this if we didn't find
     an existing member for the current source.  */
  if (loading || !foundit)
    Vload_history = Fcons (Fnreverse (Vcurrent_load_list),
			   Vload_history);
1057 1058
}

Jim Blandy's avatar
Jim Blandy committed
1059 1060 1061 1062 1063 1064 1065
Lisp_Object
unreadpure ()	/* Used as unwind-protect function in readevalloop */
{
  read_pure = 0;
  return Qnil;
}

1066 1067 1068 1069 1070 1071 1072 1073 1074
static Lisp_Object
readevalloop_1 (old)
     Lisp_Object old;
{
  load_convert_to_unibyte = ! NILP (old);
  return Qnil;
}

/* UNIBYTE specifies how to set load_convert_to_unibyte
1075 1076