search.c 83.6 KB
Newer Older
Jim Blandy's avatar
Jim Blandy committed
1
/* String search routines for GNU Emacs.
2
   Copyright (C) 1985, 86,87,93,94,97,98, 1999 Free Software Foundation, Inc.
Jim Blandy's avatar
Jim Blandy committed
3 4 5 6 7

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
Karl Heuer's avatar
Karl Heuer committed
8
the Free Software Foundation; either version 2, or (at your option)
Jim Blandy's avatar
Jim Blandy committed
9 10 11 12 13 14 15 16 17
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
18 19
the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
Boston, MA 02111-1307, USA.  */
Jim Blandy's avatar
Jim Blandy committed
20 21


22
#include <config.h>
Jim Blandy's avatar
Jim Blandy committed
23 24
#include "lisp.h"
#include "syntax.h"
Karl Heuer's avatar
Karl Heuer committed
25
#include "category.h"
Jim Blandy's avatar
Jim Blandy committed
26
#include "buffer.h"
Karl Heuer's avatar
Karl Heuer committed
27
#include "charset.h"
28
#include "region-cache.h"
Jim Blandy's avatar
Jim Blandy committed
29
#include "commands.h"
30
#include "blockinput.h"
31
#include "intervals.h"
Jim Blandy's avatar
Jim Blandy committed
32

Jim Blandy's avatar
Jim Blandy committed
33 34 35
#include <sys/types.h>
#include "regex.h"

36 37 38
#define min(a, b) ((a) < (b) ? (a) : (b))
#define max(a, b) ((a) > (b) ? (a) : (b))

39
#define REGEXP_CACHE_SIZE 20
Jim Blandy's avatar
Jim Blandy committed
40

41 42
/* If the regexp is non-nil, then the buffer contains the compiled form
   of that regexp, suitable for searching.  */
43 44
struct regexp_cache
{
45 46 47 48
  struct regexp_cache *next;
  Lisp_Object regexp;
  struct re_pattern_buffer buf;
  char fastmap[0400];
49 50
  /* Nonzero means regexp was compiled to do full POSIX backtracking.  */
  char posix;
51
};
Jim Blandy's avatar
Jim Blandy committed
52

53 54
/* The instances of that struct.  */
struct regexp_cache searchbufs[REGEXP_CACHE_SIZE];
Jim Blandy's avatar
Jim Blandy committed
55

56 57
/* The head of the linked list; points to the most recently used buffer.  */
struct regexp_cache *searchbuf_head;
Jim Blandy's avatar
Jim Blandy committed
58 59


Jim Blandy's avatar
Jim Blandy committed
60 61 62 63 64 65 66
/* Every call to re_match, etc., must pass &search_regs as the regs
   argument unless you can show it is unnecessary (i.e., if re_match
   is certainly going to be called again before region-around-match
   can be called).

   Since the registers are now dynamically allocated, we need to make
   sure not to refer to the Nth register before checking that it has
Jim Blandy's avatar
Jim Blandy committed
67 68 69
   been allocated by checking search_regs.num_regs.

   The regex code keeps track of whether it has allocated the search
70 71
   buffer using bits in the re_pattern_buffer.  This means that whenever
   you compile a new pattern, it completely forgets whether it has
Jim Blandy's avatar
Jim Blandy committed
72 73 74 75 76
   allocated any registers, and will allocate new registers the next
   time you call a searching or matching function.  Therefore, we need
   to call re_set_registers after compiling a new pattern or after
   setting the match registers, so that the regex functions will be
   able to free or re-allocate it properly.  */
Jim Blandy's avatar
Jim Blandy committed
77 78
static struct re_registers search_regs;

Jim Blandy's avatar
Jim Blandy committed
79 80 81 82
/* The buffer in which the last search was performed, or
   Qt if the last search was done in a string;
   Qnil if no searching has been done yet.  */
static Lisp_Object last_thing_searched;
Jim Blandy's avatar
Jim Blandy committed
83

Karl Heuer's avatar
Karl Heuer committed
84
/* error condition signaled when regexp compile_pattern fails */
Jim Blandy's avatar
Jim Blandy committed
85 86 87

Lisp_Object Qinvalid_regexp;

88
static void set_search_regs ();
89
static void save_search_regs ();
90 91
static int simple_search ();
static int boyer_moore ();
92 93
static int search_buffer ();

Jim Blandy's avatar
Jim Blandy committed
94 95 96 97 98 99
static void
matcher_overflow ()
{
  error ("Stack overflow in regexp matcher");
}

100 101 102
/* Compile a regexp and signal a Lisp error if anything goes wrong.
   PATTERN is the pattern to compile.
   CP is the place to put the result.
103
   TRANSLATE is a translation table for ignoring case, or nil for none.
104 105 106 107 108
   REGP is the structure that says where to store the "register"
   values that will result from matching this pattern.
   If it is 0, we should compile the pattern not to record any
   subexpression bounds.
   POSIX is nonzero if we want full backtracking (POSIX style)
Karl Heuer's avatar
Karl Heuer committed
109 110 111 112
   for this pattern.  0 means backtrack only enough to get a valid match.
   MULTIBYTE is nonzero if we want to handle multibyte characters in
   PATTERN.  0 means all multibyte characters are recognized just as
   sequences of binary data.  */
Jim Blandy's avatar
Jim Blandy committed
113

114
static void
Karl Heuer's avatar
Karl Heuer committed
115
compile_pattern_1 (cp, pattern, translate, regp, posix, multibyte)
116
     struct regexp_cache *cp;
Jim Blandy's avatar
Jim Blandy committed
117
     Lisp_Object pattern;
118
     Lisp_Object translate;
119
     struct re_registers *regp;
120
     int posix;
Karl Heuer's avatar
Karl Heuer committed
121
     int multibyte;
Jim Blandy's avatar
Jim Blandy committed
122
{
123
  unsigned char *raw_pattern;
124
  int raw_pattern_size;
125
  char *val;
126
  reg_syntax_t old;
Jim Blandy's avatar
Jim Blandy committed
127

128 129 130 131 132 133
  /* MULTIBYTE says whether the text to be searched is multibyte.
     We must convert PATTERN to match that, or we will not really
     find things right.  */

  if (multibyte == STRING_MULTIBYTE (pattern))
    {
134
      raw_pattern = (unsigned char *) XSTRING (pattern)->data;
135
      raw_pattern_size = STRING_BYTES (XSTRING (pattern));
136 137 138 139 140
    }
  else if (multibyte)
    {
      raw_pattern_size = count_size_as_multibyte (XSTRING (pattern)->data,
						  XSTRING (pattern)->size);
141
      raw_pattern = (unsigned char *) alloca (raw_pattern_size + 1);
142 143 144 145 146 147 148 149 150 151 152 153
      copy_text (XSTRING (pattern)->data, raw_pattern,
		 XSTRING (pattern)->size, 0, 1);
    }
  else
    {
      /* Converting multibyte to single-byte.

	 ??? Perhaps this conversion should be done in a special way
	 by subtracting nonascii-insert-offset from each non-ASCII char,
	 so that only the multibyte chars which really correspond to
	 the chosen single-byte character set can possibly match.  */
      raw_pattern_size = XSTRING (pattern)->size;
154
      raw_pattern = (unsigned char *) alloca (raw_pattern_size + 1);
155
      copy_text (XSTRING (pattern)->data, raw_pattern,
156
		 STRING_BYTES (XSTRING (pattern)), 1, 0);
157 158
    }

159
  cp->regexp = Qnil;
160
  cp->buf.translate = (! NILP (translate) ? translate : make_number (0));
161
  cp->posix = posix;
Karl Heuer's avatar
Karl Heuer committed
162
  cp->buf.multibyte = multibyte;
163
  BLOCK_INPUT;
164
  old = re_set_syntax (RE_SYNTAX_EMACS
165
		       | (posix ? 0 : RE_NO_POSIX_BACKTRACKING));
166 167
  val = (char *) re_compile_pattern ((char *)raw_pattern,
				     raw_pattern_size, &cp->buf);
168
  re_set_syntax (old);
169
  UNBLOCK_INPUT;
Jim Blandy's avatar
Jim Blandy committed
170
  if (val)
171
    Fsignal (Qinvalid_regexp, Fcons (build_string (val), Qnil));
Jim Blandy's avatar
Jim Blandy committed
172

173 174 175
  cp->regexp = Fcopy_sequence (pattern);
}

176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192
/* Shrink each compiled regexp buffer in the cache
   to the size actually used right now.
   This is called from garbage collection.  */

void
shrink_regexp_cache ()
{
  struct regexp_cache *cp, **cpp;

  for (cp = searchbuf_head; cp != 0; cp = cp->next)
    {
      cp->buf.allocated = cp->buf.used;
      cp->buf.buffer
	= (unsigned char *) realloc (cp->buf.buffer, cp->buf.used);
    }
}

193
/* Compile a regexp if necessary, but first check to see if there's one in
194 195
   the cache.
   PATTERN is the pattern to compile.
196
   TRANSLATE is a translation table for ignoring case, or nil for none.
197 198 199 200 201 202
   REGP is the structure that says where to store the "register"
   values that will result from matching this pattern.
   If it is 0, we should compile the pattern not to record any
   subexpression bounds.
   POSIX is nonzero if we want full backtracking (POSIX style)
   for this pattern.  0 means backtrack only enough to get a valid match.  */
203 204

struct re_pattern_buffer *
205
compile_pattern (pattern, regp, translate, posix, multibyte)
206 207
     Lisp_Object pattern;
     struct re_registers *regp;
208
     Lisp_Object translate;
209
     int posix, multibyte;
210 211 212 213 214 215
{
  struct regexp_cache *cp, **cpp;

  for (cpp = &searchbuf_head; ; cpp = &cp->next)
    {
      cp = *cpp;
216 217 218 219 220
      /* Entries are initialized to nil, and may be set to nil by
	 compile_pattern_1 if the pattern isn't valid.  Don't apply
	 XSTRING in those cases.  However, compile_pattern_1 is only
	 applied to the cache entry we pick here to reuse.  So nil
	 should never appear before a non-nil entry.  */
221
      if (NILP (cp->regexp))
222
	goto compile_it;
223 224
      if (XSTRING (cp->regexp)->size == XSTRING (pattern)->size
	  && !NILP (Fstring_equal (cp->regexp, pattern))
225
	  && EQ (cp->buf.translate, (! NILP (translate) ? translate : make_number (0)))
Karl Heuer's avatar
Karl Heuer committed
226 227
	  && cp->posix == posix
	  && cp->buf.multibyte == multibyte)
228 229
	break;

230 231 232
      /* If we're at the end of the cache, compile into the nil cell
	 we found, or the last (least recently used) cell with a
	 string value.  */
233 234
      if (cp->next == 0)
	{
235
	compile_it:
Karl Heuer's avatar
Karl Heuer committed
236
	  compile_pattern_1 (cp, pattern, translate, regp, posix, multibyte);
237 238 239 240 241 242 243 244 245 246
	  break;
	}
    }

  /* When we get here, cp (aka *cpp) contains the compiled pattern,
     either because we found it in the cache or because we just compiled it.
     Move it to the front of the queue to mark it as most recently used.  */
  *cpp = cp->next;
  cp->next = searchbuf_head;
  searchbuf_head = cp;
Jim Blandy's avatar
Jim Blandy committed
247

248 249 250 251 252
  /* Advise the searching functions about the space we have allocated
     for register data.  */
  if (regp)
    re_set_registers (&cp->buf, regp, regp->num_regs, regp->start, regp->end);

253
  return &cp->buf;
Jim Blandy's avatar
Jim Blandy committed
254 255 256 257 258 259 260 261 262 263 264 265 266
}

/* Error condition used for failing searches */
Lisp_Object Qsearch_failed;

Lisp_Object
signal_failure (arg)
     Lisp_Object arg;
{
  Fsignal (Qsearch_failed, Fcons (arg, Qnil));
  return Qnil;
}

267 268
static Lisp_Object
looking_at_1 (string, posix)
Jim Blandy's avatar
Jim Blandy committed
269
     Lisp_Object string;
270
     int posix;
Jim Blandy's avatar
Jim Blandy committed
271 272 273 274 275
{
  Lisp_Object val;
  unsigned char *p1, *p2;
  int s1, s2;
  register int i;
276
  struct re_pattern_buffer *bufp;
Jim Blandy's avatar
Jim Blandy committed
277

278 279 280
  if (running_asynch_code)
    save_search_regs ();

Jim Blandy's avatar
Jim Blandy committed
281
  CHECK_STRING (string, 0);
282 283
  bufp = compile_pattern (string, &search_regs,
			  (!NILP (current_buffer->case_fold_search)
284
			   ? DOWNCASE_TABLE : Qnil),
285 286
			  posix,
			  !NILP (current_buffer->enable_multibyte_characters));
Jim Blandy's avatar
Jim Blandy committed
287 288 289 290 291 292 293 294

  immediate_quit = 1;
  QUIT;			/* Do a pending quit right away, to avoid paradoxical behavior */

  /* Get pointers and sizes of the two strings
     that make up the visible portion of the buffer. */

  p1 = BEGV_ADDR;
295
  s1 = GPT_BYTE - BEGV_BYTE;
Jim Blandy's avatar
Jim Blandy committed
296
  p2 = GAP_END_ADDR;
297
  s2 = ZV_BYTE - GPT_BYTE;
Jim Blandy's avatar
Jim Blandy committed
298 299 300
  if (s1 < 0)
    {
      p2 = p1;
301
      s2 = ZV_BYTE - BEGV_BYTE;
Jim Blandy's avatar
Jim Blandy committed
302 303 304 305
      s1 = 0;
    }
  if (s2 < 0)
    {
306
      s1 = ZV_BYTE - BEGV_BYTE;
Jim Blandy's avatar
Jim Blandy committed
307 308
      s2 = 0;
    }
309 310

  re_match_object = Qnil;
Jim Blandy's avatar
Jim Blandy committed
311
  
312
  i = re_match_2 (bufp, (char *) p1, s1, (char *) p2, s2,
313 314
		  PT_BYTE - BEGV_BYTE, &search_regs,
		  ZV_BYTE - BEGV_BYTE);
315 316
  immediate_quit = 0;
  
Jim Blandy's avatar
Jim Blandy committed
317 318 319 320
  if (i == -2)
    matcher_overflow ();

  val = (0 <= i ? Qt : Qnil);
321 322 323 324 325 326 327 328 329
  if (i >= 0)
    for (i = 0; i < search_regs.num_regs; i++)
      if (search_regs.start[i] >= 0)
	{
	  search_regs.start[i]
	    = BYTE_TO_CHAR (search_regs.start[i] + BEGV_BYTE);
	  search_regs.end[i]
	    = BYTE_TO_CHAR (search_regs.end[i] + BEGV_BYTE);
	}
330
  XSETBUFFER (last_thing_searched, current_buffer);
Jim Blandy's avatar
Jim Blandy committed
331 332 333
  return val;
}

334
DEFUN ("looking-at", Flooking_at, Slooking_at, 1, 1, 0,
335
  "Return t if text after point matches regular expression REGEXP.\n\
336 337 338
This function modifies the match data that `match-beginning',\n\
`match-end' and `match-data' access; save and restore the match\n\
data if you want to preserve them.")
339 340
  (regexp)
     Lisp_Object regexp;
341
{
342
  return looking_at_1 (regexp, 0);
343 344 345
}

DEFUN ("posix-looking-at", Fposix_looking_at, Sposix_looking_at, 1, 1, 0,
346
  "Return t if text after point matches regular expression REGEXP.\n\
347 348 349 350
Find the longest match, in accord with Posix regular expression rules.\n\
This function modifies the match data that `match-beginning',\n\
`match-end' and `match-data' access; save and restore the match\n\
data if you want to preserve them.")
351 352
  (regexp)
     Lisp_Object regexp;
353
{
354
  return looking_at_1 (regexp, 1);
355 356 357 358
}

static Lisp_Object
string_match_1 (regexp, string, start, posix)
Jim Blandy's avatar
Jim Blandy committed
359
     Lisp_Object regexp, string, start;
360
     int posix;
Jim Blandy's avatar
Jim Blandy committed
361 362
{
  int val;
363
  struct re_pattern_buffer *bufp;
364 365
  int pos, pos_byte;
  int i;
Jim Blandy's avatar
Jim Blandy committed
366

367 368 369
  if (running_asynch_code)
    save_search_regs ();

Jim Blandy's avatar
Jim Blandy committed
370 371 372 373
  CHECK_STRING (regexp, 0);
  CHECK_STRING (string, 1);

  if (NILP (start))
374
    pos = 0, pos_byte = 0;
Jim Blandy's avatar
Jim Blandy committed
375 376 377 378 379
  else
    {
      int len = XSTRING (string)->size;

      CHECK_NUMBER (start, 2);
380 381 382 383
      pos = XINT (start);
      if (pos < 0 && -pos <= len)
	pos = len + pos;
      else if (0 > pos || pos > len)
Jim Blandy's avatar
Jim Blandy committed
384
	args_out_of_range (string, start);
385
      pos_byte = string_char_to_byte (string, pos);
Jim Blandy's avatar
Jim Blandy committed
386 387
    }

388 389
  bufp = compile_pattern (regexp, &search_regs,
			  (!NILP (current_buffer->case_fold_search)
390
			   ? DOWNCASE_TABLE : Qnil),
391 392
			  posix,
			  STRING_MULTIBYTE (string));
Jim Blandy's avatar
Jim Blandy committed
393
  immediate_quit = 1;
394 395
  re_match_object = string;
  
396
  val = re_search (bufp, (char *) XSTRING (string)->data,
397 398
		   STRING_BYTES (XSTRING (string)), pos_byte,
		   STRING_BYTES (XSTRING (string)) - pos_byte,
Jim Blandy's avatar
Jim Blandy committed
399 400
		   &search_regs);
  immediate_quit = 0;
Jim Blandy's avatar
Jim Blandy committed
401
  last_thing_searched = Qt;
Jim Blandy's avatar
Jim Blandy committed
402 403 404
  if (val == -2)
    matcher_overflow ();
  if (val < 0) return Qnil;
405 406 407 408 409 410 411 412 413 414 415

  for (i = 0; i < search_regs.num_regs; i++)
    if (search_regs.start[i] >= 0)
      {
	search_regs.start[i]
	  = string_byte_to_char (string, search_regs.start[i]);
	search_regs.end[i]
	  = string_byte_to_char (string, search_regs.end[i]);
      }

  return make_number (string_byte_to_char (string, val));
Jim Blandy's avatar
Jim Blandy committed
416
}
Richard M. Stallman's avatar
Richard M. Stallman committed
417

418 419
DEFUN ("string-match", Fstring_match, Sstring_match, 2, 3, 0,
  "Return index of start of first match for REGEXP in STRING, or nil.\n\
420
Case is ignored if `case-fold-search' is non-nil in the current buffer.\n\
421 422 423 424 425 426 427 428 429 430 431 432 433
If third arg START is non-nil, start search at that index in STRING.\n\
For index of first char beyond the match, do (match-end 0).\n\
`match-end' and `match-beginning' also give indices of substrings\n\
matched by parenthesis constructs in the pattern.")
  (regexp, string, start)
     Lisp_Object regexp, string, start;
{
  return string_match_1 (regexp, string, start, 0);
}

DEFUN ("posix-string-match", Fposix_string_match, Sposix_string_match, 2, 3, 0,
  "Return index of start of first match for REGEXP in STRING, or nil.\n\
Find the longest match, in accord with Posix regular expression rules.\n\
434
Case is ignored if `case-fold-search' is non-nil in the current buffer.\n\
435 436 437 438 439 440 441 442 443 444
If third arg START is non-nil, start search at that index in STRING.\n\
For index of first char beyond the match, do (match-end 0).\n\
`match-end' and `match-beginning' also give indices of substrings\n\
matched by parenthesis constructs in the pattern.")
  (regexp, string, start)
     Lisp_Object regexp, string, start;
{
  return string_match_1 (regexp, string, start, 1);
}

Richard M. Stallman's avatar
Richard M. Stallman committed
445 446 447 448 449 450 451 452 453
/* Match REGEXP against STRING, searching all of STRING,
   and return the index of the match, or negative on failure.
   This does not clobber the match data.  */

int
fast_string_match (regexp, string)
     Lisp_Object regexp, string;
{
  int val;
454
  struct re_pattern_buffer *bufp;
Richard M. Stallman's avatar
Richard M. Stallman committed
455

456 457
  bufp = compile_pattern (regexp, 0, Qnil,
			  0, STRING_MULTIBYTE (string));
Richard M. Stallman's avatar
Richard M. Stallman committed
458
  immediate_quit = 1;
459 460
  re_match_object = string;
  
461
  val = re_search (bufp, (char *) XSTRING (string)->data,
462 463
		   STRING_BYTES (XSTRING (string)), 0,
		   STRING_BYTES (XSTRING (string)), 0);
Richard M. Stallman's avatar
Richard M. Stallman committed
464 465 466
  immediate_quit = 0;
  return val;
}
Karl Heuer's avatar
Karl Heuer committed
467 468 469

/* Match REGEXP against STRING, searching all of STRING ignoring case,
   and return the index of the match, or negative on failure.
470 471
   This does not clobber the match data.
   We assume that STRING contains single-byte characters.  */
Karl Heuer's avatar
Karl Heuer committed
472 473 474 475

extern Lisp_Object Vascii_downcase_table;

int
476
fast_c_string_match_ignore_case (regexp, string)
Karl Heuer's avatar
Karl Heuer committed
477 478 479 480 481 482 483
     Lisp_Object regexp;
     char *string;
{
  int val;
  struct re_pattern_buffer *bufp;
  int len = strlen (string);

484
  regexp = string_make_unibyte (regexp);
485
  re_match_object = Qt;
Karl Heuer's avatar
Karl Heuer committed
486
  bufp = compile_pattern (regexp, 0,
487
			  Vascii_downcase_table, 0,
488
			  0);
Karl Heuer's avatar
Karl Heuer committed
489 490 491 492 493
  immediate_quit = 1;
  val = re_search (bufp, string, len, 0, len, 0);
  immediate_quit = 0;
  return val;
}
494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531

/* The newline cache: remembering which sections of text have no newlines.  */

/* If the user has requested newline caching, make sure it's on.
   Otherwise, make sure it's off.
   This is our cheezy way of associating an action with the change of
   state of a buffer-local variable.  */
static void
newline_cache_on_off (buf)
     struct buffer *buf;
{
  if (NILP (buf->cache_long_line_scans))
    {
      /* It should be off.  */
      if (buf->newline_cache)
        {
          free_region_cache (buf->newline_cache);
          buf->newline_cache = 0;
        }
    }
  else
    {
      /* It should be on.  */
      if (buf->newline_cache == 0)
        buf->newline_cache = new_region_cache ();
    }
}


/* Search for COUNT instances of the character TARGET between START and END.

   If COUNT is positive, search forwards; END must be >= START.
   If COUNT is negative, search backwards for the -COUNTth instance;
      END must be <= START.
   If COUNT is zero, do anything you please; run rogue, for all I care.

   If END is zero, use BEGV or ZV instead, as appropriate for the
   direction indicated by COUNT.
Jim Blandy's avatar
Jim Blandy committed
532 533

   If we find COUNT instances, set *SHORTAGE to zero, and return the
Richard M. Stallman's avatar
Richard M. Stallman committed
534 535
   position after the COUNTth match.  Note that for reverse motion
   this is not the same as the usual convention for Emacs motion commands.
Jim Blandy's avatar
Jim Blandy committed
536

537 538
   If we don't find COUNT instances before reaching END, set *SHORTAGE
   to the number of TARGETs left unfound, and return END.
Jim Blandy's avatar
Jim Blandy committed
539

540 541 542
   If ALLOW_QUIT is non-zero, set immediate_quit.  That's good to do
   except when inside redisplay.  */

Andreas Schwab's avatar
Andreas Schwab committed
543
int
544 545 546 547 548
scan_buffer (target, start, end, count, shortage, allow_quit)
     register int target;
     int start, end;
     int count;
     int *shortage;
549
     int allow_quit;
Jim Blandy's avatar
Jim Blandy committed
550
{
551 552
  struct region_cache *newline_cache;
  int direction; 
Jim Blandy's avatar
Jim Blandy committed
553

554 555 556 557 558 559 560 561 562 563
  if (count > 0)
    {
      direction = 1;
      if (! end) end = ZV;
    }
  else
    {
      direction = -1;
      if (! end) end = BEGV;
    }
Jim Blandy's avatar
Jim Blandy committed
564

565 566
  newline_cache_on_off (current_buffer);
  newline_cache = current_buffer->newline_cache;
Jim Blandy's avatar
Jim Blandy committed
567 568 569 570

  if (shortage != 0)
    *shortage = 0;

571
  immediate_quit = allow_quit;
Jim Blandy's avatar
Jim Blandy committed
572

Jim Blandy's avatar
Jim Blandy committed
573
  if (count > 0)
574
    while (start != end)
Jim Blandy's avatar
Jim Blandy committed
575
      {
576 577 578 579 580
        /* Our innermost scanning loop is very simple; it doesn't know
           about gaps, buffer ends, or the newline cache.  ceiling is
           the position of the last character before the next such
           obstacle --- the last character the dumb search loop should
           examine.  */
581 582
	int ceiling_byte = CHAR_TO_BYTE (end) - 1;
	int start_byte = CHAR_TO_BYTE (start);
583
	int tem;
584 585 586 587 588 589 590 591

        /* If we're looking for a newline, consult the newline cache
           to see where we can avoid some scanning.  */
        if (target == '\n' && newline_cache)
          {
            int next_change;
            immediate_quit = 0;
            while (region_cache_forward
592 593
                   (current_buffer, newline_cache, start_byte, &next_change))
              start_byte = next_change;
594
            immediate_quit = allow_quit;
595

596 597 598
            /* START should never be after END.  */
            if (start_byte > ceiling_byte)
              start_byte = ceiling_byte;
599 600 601

            /* Now the text after start is an unknown region, and
               next_change is the position of the next known region. */
602
            ceiling_byte = min (next_change - 1, ceiling_byte);
603 604 605 606 607 608
          }

        /* The dumb loop can only scan text stored in contiguous
           bytes. BUFFER_CEILING_OF returns the last character
           position that is contiguous, so the ceiling is the
           position after that.  */
609 610
	tem = BUFFER_CEILING_OF (start_byte);
	ceiling_byte = min (tem, ceiling_byte);
611 612 613

        {
          /* The termination address of the dumb loop.  */ 
614 615 616 617
          register unsigned char *ceiling_addr
	    = BYTE_POS_ADDR (ceiling_byte) + 1;
          register unsigned char *cursor
	    = BYTE_POS_ADDR (start_byte);
618 619 620 621 622 623 624 625 626 627 628 629 630 631
          unsigned char *base = cursor;

          while (cursor < ceiling_addr)
            {
              unsigned char *scan_start = cursor;

              /* The dumb loop.  */
              while (*cursor != target && ++cursor < ceiling_addr)
                ;

              /* If we're looking for newlines, cache the fact that
                 the region from start to cursor is free of them. */
              if (target == '\n' && newline_cache)
                know_region_cache (current_buffer, newline_cache,
632 633
                                   start_byte + scan_start - base,
                                   start_byte + cursor - base);
634 635 636 637 638 639 640

              /* Did we find the target character?  */
              if (cursor < ceiling_addr)
                {
                  if (--count == 0)
                    {
                      immediate_quit = 0;
641
                      return BYTE_TO_CHAR (start_byte + cursor - base + 1);
642 643 644 645 646
                    }
                  cursor++;
                }
            }

647
          start = BYTE_TO_CHAR (start_byte + cursor - base);
648
        }
Jim Blandy's avatar
Jim Blandy committed
649 650
      }
  else
651 652 653
    while (start > end)
      {
        /* The last character to check before the next obstacle.  */
654 655
	int ceiling_byte = CHAR_TO_BYTE (end);
	int start_byte = CHAR_TO_BYTE (start);
656
	int tem;
657 658 659 660 661 662 663

        /* Consult the newline cache, if appropriate.  */
        if (target == '\n' && newline_cache)
          {
            int next_change;
            immediate_quit = 0;
            while (region_cache_backward
664 665
                   (current_buffer, newline_cache, start_byte, &next_change))
              start_byte = next_change;
666
            immediate_quit = allow_quit;
667 668

            /* Start should never be at or before end.  */
669 670
            if (start_byte <= ceiling_byte)
              start_byte = ceiling_byte + 1;
671 672 673

            /* Now the text before start is an unknown region, and
               next_change is the position of the next known region. */
674
            ceiling_byte = max (next_change, ceiling_byte);
675 676 677
          }

        /* Stop scanning before the gap.  */
678 679
	tem = BUFFER_FLOOR_OF (start_byte - 1);
	ceiling_byte = max (tem, ceiling_byte);
680 681 682

        {
          /* The termination address of the dumb loop.  */
683 684
          register unsigned char *ceiling_addr = BYTE_POS_ADDR (ceiling_byte);
          register unsigned char *cursor = BYTE_POS_ADDR (start_byte - 1);
685 686 687 688 689 690 691 692 693 694 695 696 697
          unsigned char *base = cursor;

          while (cursor >= ceiling_addr)
            {
              unsigned char *scan_start = cursor;

              while (*cursor != target && --cursor >= ceiling_addr)
                ;

              /* If we're looking for newlines, cache the fact that
                 the region from after the cursor to start is free of them.  */
              if (target == '\n' && newline_cache)
                know_region_cache (current_buffer, newline_cache,
698 699
                                   start_byte + cursor - base,
                                   start_byte + scan_start - base);
700 701 702 703 704 705 706

              /* Did we find the target character?  */
              if (cursor >= ceiling_addr)
                {
                  if (++count >= 0)
                    {
                      immediate_quit = 0;
707
                      return BYTE_TO_CHAR (start_byte + cursor - base);
708 709 710 711 712
                    }
                  cursor--;
                }
            }

713
	  start = BYTE_TO_CHAR (start_byte + cursor - base);
714 715 716
        }
      }

Jim Blandy's avatar
Jim Blandy committed
717 718
  immediate_quit = 0;
  if (shortage != 0)
Jim Blandy's avatar
Jim Blandy committed
719
    *shortage = count * direction;
720
  return start;
Jim Blandy's avatar
Jim Blandy committed
721
}
722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737

/* Search for COUNT instances of a line boundary, which means either a
   newline or (if selective display enabled) a carriage return.
   Start at START.  If COUNT is negative, search backwards.

   We report the resulting position by calling TEMP_SET_PT_BOTH.

   If we find COUNT instances. we position after (always after,
   even if scanning backwards) the COUNTth match, and return 0.

   If we don't find COUNT instances before reaching the end of the
   buffer (or the beginning, if scanning backwards), we return
   the number of line boundaries left unfound, and position at
   the limit we bumped up against.

   If ALLOW_QUIT is non-zero, set immediate_quit.  That's good to do
738
   except in special cases.  */
Jim Blandy's avatar
Jim Blandy committed
739

740
int
741 742 743 744 745
scan_newline (start, start_byte, limit, limit_byte, count, allow_quit)
     int start, start_byte;
     int limit, limit_byte;
     register int count;
     int allow_quit;
746
{
747 748 749 750 751 752 753 754
  int direction = ((count > 0) ? 1 : -1);

  register unsigned char *cursor;
  unsigned char *base;

  register int ceiling;
  register unsigned char *ceiling_addr;

755 756
  int old_immediate_quit = immediate_quit;

757 758 759 760 761 762 763 764
  /* If we are not in selective display mode,
     check only for newlines.  */
  int selective_display = (!NILP (current_buffer->selective_display)
			   && !INTEGERP (current_buffer->selective_display));

  /* The code that follows is like scan_buffer
     but checks for either newline or carriage return.  */

765 766
  if (allow_quit)
    immediate_quit++;
767 768 769 770 771 772 773 774 775 776 777 778 779 780 781 782 783 784 785 786

  start_byte = CHAR_TO_BYTE (start);

  if (count > 0)
    {
      while (start_byte < limit_byte)
	{
	  ceiling =  BUFFER_CEILING_OF (start_byte);
	  ceiling = min (limit_byte - 1, ceiling);
	  ceiling_addr = BYTE_POS_ADDR (ceiling) + 1;
	  base = (cursor = BYTE_POS_ADDR (start_byte));
	  while (1)
	    {
	      while (*cursor != '\n' && ++cursor != ceiling_addr)
		;

	      if (cursor != ceiling_addr)
		{
		  if (--count == 0)
		    {
787
		      immediate_quit = old_immediate_quit;
788 789 790 791 792 793 794 795 796 797 798 799 800 801 802 803 804 805 806 807 808 809 810 811 812 813 814 815 816 817 818 819
		      start_byte = start_byte + cursor - base + 1;
		      start = BYTE_TO_CHAR (start_byte);
		      TEMP_SET_PT_BOTH (start, start_byte);
		      return 0;
		    }
		  else
		    if (++cursor == ceiling_addr)
		      break;
		}
	      else
		break;
	    }
	  start_byte += cursor - base;
	}
    }
  else
    {
      while (start_byte > limit_byte)
	{
	  ceiling = BUFFER_FLOOR_OF (start_byte - 1);
	  ceiling = max (limit_byte, ceiling);
	  ceiling_addr = BYTE_POS_ADDR (ceiling) - 1;
	  base = (cursor = BYTE_POS_ADDR (start_byte - 1) + 1);
	  while (1)
	    {
	      while (--cursor != ceiling_addr && *cursor != '\n')
		;

	      if (cursor != ceiling_addr)
		{
		  if (++count == 0)
		    {
820
		      immediate_quit = old_immediate_quit;
821 822 823 824 825 826 827 828 829 830 831 832 833 834 835 836 837
		      /* Return the position AFTER the match we found.  */
		      start_byte = start_byte + cursor - base + 1;
		      start = BYTE_TO_CHAR (start_byte);
		      TEMP_SET_PT_BOTH (start, start_byte);
		      return 0;
		    }
		}
	      else
		break;
	    }
	  /* Here we add 1 to compensate for the last decrement
	     of CURSOR, which took it past the valid range.  */
	  start_byte += cursor - base + 1;
	}
    }

  TEMP_SET_PT_BOTH (limit, limit_byte);
838
  immediate_quit = old_immediate_quit;
839 840

  return count * direction;
841 842
}

Jim Blandy's avatar
Jim Blandy committed
843
int
844
find_next_newline_no_quit (from, cnt)
Jim Blandy's avatar
Jim Blandy committed
845 846
     register int from, cnt;
{
847
  return scan_buffer ('\n', from, 0, cnt, (int *) 0, 0);
848 849 850 851 852
}

/* Like find_next_newline, but returns position before the newline,
   not after, and only search up to TO.  This isn't just
   find_next_newline (...)-1, because you might hit TO.  */
853

854 855
int
find_before_next_newline (from, to, cnt)
856
     int from, to, cnt;
857 858 859 860 861 862 863 864
{
  int shortage;
  int pos = scan_buffer ('\n', from, to, cnt, &shortage, 1);

  if (shortage == 0)
    pos--;
  
  return pos;
Jim Blandy's avatar
Jim Blandy committed
865 866 867 868 869
}

/* Subroutines of Lisp buffer search functions. */

static Lisp_Object
870
search_command (string, bound, noerror, count, direction, RE, posix)
Jim Blandy's avatar
Jim Blandy committed
871 872 873
     Lisp_Object string, bound, noerror, count;
     int direction;
     int RE;
874
     int posix;
Jim Blandy's avatar
Jim Blandy committed
875 876
{
  register int np;
877
  int lim, lim_byte;
Jim Blandy's avatar
Jim Blandy committed
878 879 880 881 882 883 884 885 886 887
  int n = direction;

  if (!NILP (count))
    {
      CHECK_NUMBER (count, 3);
      n *= XINT (count);
    }

  CHECK_STRING (string, 0);
  if (NILP (bound))
888 889 890 891 892 893
    {
      if (n > 0)
	lim = ZV, lim_byte = ZV_BYTE;
      else
	lim = BEGV, lim_byte = BEGV_BYTE;
    }
Jim Blandy's avatar
Jim Blandy committed
894 895 896 897
  else
    {
      CHECK_NUMBER_COERCE_MARKER (bound, 1);
      lim = XINT (bound);
898
      if (n > 0 ? lim < PT : lim > PT)
Jim Blandy's avatar
Jim Blandy committed
899 900
	error ("Invalid search bound (wrong side of point)");
      if (lim > ZV)
901
	lim = ZV, lim_byte = ZV_BYTE;
902
      else if (lim < BEGV)
903
	lim = BEGV, lim_byte = BEGV_BYTE;
904 905
      else
	lim_byte = CHAR_TO_BYTE (lim);
Jim Blandy's avatar
Jim Blandy committed
906 907
    }

908
  np = search_buffer (string, PT, PT_BYTE, lim, lim_byte, n, RE,
Jim Blandy's avatar
Jim Blandy committed
909
		      (!NILP (current_buffer->case_fold_search)
910
		       ? current_buffer->case_canon_table
911
		       : Qnil),
Jim Blandy's avatar
Jim Blandy committed
912
		      (!NILP (current_buffer->case_fold_search)
913
		       ? current_buffer->case_eqv_table
914
		       : Qnil),
915
		      posix);
Jim Blandy's avatar
Jim Blandy committed
916 917 918 919 920 921 922 923
  if (np <= 0)
    {
      if (NILP (noerror))
	return signal_failure (string);
      if (!EQ (noerror, Qt))
	{
	  if (lim < BEGV || lim > ZV)
	    abort ();
924
	  SET_PT_BOTH (lim, lim_byte);
925 926 927
	  return Qnil;
#if 0 /* This would be clean, but maybe programs depend on
	 a value of nil here.  */
928
	  np = lim;
929
#endif
Jim Blandy's avatar
Jim Blandy committed
930
	}
931 932
      else
	return Qnil;
Jim Blandy's avatar
Jim Blandy committed
933 934 935 936 937 938 939 940 941 942
    }

  if (np < BEGV || np > ZV)
    abort ();

  SET_PT (np);

  return make_number (np);
}

943 944
/* Return 1 if REGEXP it matches just one constant string.  */

Karl Heuer's avatar
Karl Heuer committed
945 946 947 948
static int
trivial_regexp_p (regexp)
     Lisp_Object regexp;
{
949
  int len = STRING_BYTES (XSTRING (regexp));
Karl Heuer's avatar
Karl Heuer committed
950 951 952 953 954 955 956 957 958 959 960 961 962 963 964
  unsigned char *s = XSTRING (regexp)->data;
  unsigned char c;
  while (--len >= 0)
    {
      switch (*s++)
	{
	case '.': case '*': case '+': case '?': case '[': case '^': case '$':
	  return 0;
	case '\\':
	  if (--len < 0)
	    return 0;
	  switch (*s++)
	    {
	    case '|': case '(': case ')': case '`': case '\'': case 'b':
	    case 'B': case '<': case '>': case 'w': case 'W': case 's':
965
	    case 'S': case '=':
Karl Heuer's avatar
Karl Heuer committed
966
	    case 'c': case 'C':	/* for categoryspec and notcategoryspec */
967
	    case '1': case '2': case '3': case '4': case '5':
Karl Heuer's avatar
Karl Heuer committed
968 969 970 971 972 973 974 975
	    case '6': case '7': case '8': case '9':
	      return 0;
	    }
	}
    }
  return 1;
}

976
/* Search for the n'th occurrence of STRING in the current buffer,
Jim Blandy's avatar
Jim Blandy committed
977
   starting at position POS and stopping at position LIM,
978
   treating STRING as a literal string if RE is false or as
Jim Blandy's avatar
Jim Blandy committed
979 980 981 982 983
   a regular expression if RE is true.

   If N is positive, searching is forward and LIM must be greater than POS.
   If N is negative, searching is backward and LIM must be less than POS.

984
   Returns -x if x occurrences remain to be found (x > 0),
Jim Blandy's avatar
Jim Blandy committed
985
   or else the position at the beginning of the Nth occurrence
986 987 988 989
   (if searching backward) or the end (if searching forward).

   POSIX is nonzero if we want full backtracking (POSIX style)
   for this pattern.  0 means backtrack only enough to get a valid match.  */
Jim Blandy's avatar
Jim Blandy committed
990

991 992 993 994 995 996 997 998 999 1000 1001 1002 1003 1004 1005 1006
#define TRANSLATE(out, trt, d)			\
do						\
  {						\
    if (! NILP (trt))				\
      {						\
	Lisp_Object temp;			\
	temp = Faref (trt, make_number (d));	\
	if (INTEGERP (temp))			\
	  out = XINT (temp);			\
	else					\
	  out = d;				\
      }						\
    else					\
      out = d;					\
  }						\
while (0)
1007

1008
static int
1009 1010
search_buffer (string, pos, pos_byte, lim, lim_byte, n,
	       RE, trt, inverse_trt, posix)
Jim Blandy's avatar
Jim Blandy committed
1011 1012
     Lisp_Object string;
     int pos;
1013
     int pos_byte;
Jim Blandy's avatar
Jim Blandy committed
1014
     int lim;
1015
     int lim_byte;
Jim Blandy's avatar
Jim Blandy committed
1016 1017
     int n;
     int RE;
1018 1019
     Lisp_Object trt;
     Lisp_Object inverse_trt;
1020
     int posix;
Jim Blandy's avatar
Jim Blandy committed