xref: /dragonfly/contrib/grep/lib/regcomp.c (revision 52f9f0d9)
1 /* Extended regular expression matching and search library.
2    Copyright (C) 2002-2012 Free Software Foundation, Inc.
3    This file is part of the GNU C Library.
4    Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>.
5 
6    This program is free software; you can redistribute it and/or modify
7    it under the terms of the GNU General Public License as published by
8    the Free Software Foundation; either version 3, or (at your option)
9    any later version.
10 
11    This program is distributed in the hope that it will be useful,
12    but WITHOUT ANY WARRANTY; without even the implied warranty of
13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14    GNU General Public License for more details.
15 
16    You should have received a copy of the GNU General Public License along
17    with this program; if not, see <http://www.gnu.org/licenses/>.  */
18 
19 static reg_errcode_t re_compile_internal (regex_t *preg, const char * pattern,
20 					  size_t length, reg_syntax_t syntax);
21 static void re_compile_fastmap_iter (regex_t *bufp,
22 				     const re_dfastate_t *init_state,
23 				     char *fastmap);
24 static reg_errcode_t init_dfa (re_dfa_t *dfa, size_t pat_len);
25 #ifdef RE_ENABLE_I18N
26 static void free_charset (re_charset_t *cset);
27 #endif /* RE_ENABLE_I18N */
28 static void free_workarea_compile (regex_t *preg);
29 static reg_errcode_t create_initial_state (re_dfa_t *dfa);
30 #ifdef RE_ENABLE_I18N
31 static void optimize_utf8 (re_dfa_t *dfa);
32 #endif
33 static reg_errcode_t analyze (regex_t *preg);
34 static reg_errcode_t preorder (bin_tree_t *root,
35 			       reg_errcode_t (fn (void *, bin_tree_t *)),
36 			       void *extra);
37 static reg_errcode_t postorder (bin_tree_t *root,
38 				reg_errcode_t (fn (void *, bin_tree_t *)),
39 				void *extra);
40 static reg_errcode_t optimize_subexps (void *extra, bin_tree_t *node);
41 static reg_errcode_t lower_subexps (void *extra, bin_tree_t *node);
42 static bin_tree_t *lower_subexp (reg_errcode_t *err, regex_t *preg,
43 				 bin_tree_t *node);
44 static reg_errcode_t calc_first (void *extra, bin_tree_t *node);
45 static reg_errcode_t calc_next (void *extra, bin_tree_t *node);
46 static reg_errcode_t link_nfa_nodes (void *extra, bin_tree_t *node);
47 static Idx duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint);
48 static Idx search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
49 				   unsigned int constraint);
50 static reg_errcode_t calc_eclosure (re_dfa_t *dfa);
51 static reg_errcode_t calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa,
52 					 Idx node, bool root);
53 static reg_errcode_t calc_inveclosure (re_dfa_t *dfa);
54 static Idx fetch_number (re_string_t *input, re_token_t *token,
55 			 reg_syntax_t syntax);
56 static int peek_token (re_token_t *token, re_string_t *input,
57 			reg_syntax_t syntax) internal_function;
58 static bin_tree_t *parse (re_string_t *regexp, regex_t *preg,
59 			  reg_syntax_t syntax, reg_errcode_t *err);
60 static bin_tree_t *parse_reg_exp (re_string_t *regexp, regex_t *preg,
61 				  re_token_t *token, reg_syntax_t syntax,
62 				  Idx nest, reg_errcode_t *err);
63 static bin_tree_t *parse_branch (re_string_t *regexp, regex_t *preg,
64 				 re_token_t *token, reg_syntax_t syntax,
65 				 Idx nest, reg_errcode_t *err);
66 static bin_tree_t *parse_expression (re_string_t *regexp, regex_t *preg,
67 				     re_token_t *token, reg_syntax_t syntax,
68 				     Idx nest, reg_errcode_t *err);
69 static bin_tree_t *parse_sub_exp (re_string_t *regexp, regex_t *preg,
70 				  re_token_t *token, reg_syntax_t syntax,
71 				  Idx nest, reg_errcode_t *err);
72 static bin_tree_t *parse_dup_op (bin_tree_t *dup_elem, re_string_t *regexp,
73 				 re_dfa_t *dfa, re_token_t *token,
74 				 reg_syntax_t syntax, reg_errcode_t *err);
75 static bin_tree_t *parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa,
76 				      re_token_t *token, reg_syntax_t syntax,
77 				      reg_errcode_t *err);
78 static reg_errcode_t parse_bracket_element (bracket_elem_t *elem,
79 					    re_string_t *regexp,
80 					    re_token_t *token, int token_len,
81 					    re_dfa_t *dfa,
82 					    reg_syntax_t syntax,
83 					    bool accept_hyphen);
84 static reg_errcode_t parse_bracket_symbol (bracket_elem_t *elem,
85 					  re_string_t *regexp,
86 					  re_token_t *token);
87 #ifdef RE_ENABLE_I18N
88 static reg_errcode_t build_equiv_class (bitset_t sbcset,
89 					re_charset_t *mbcset,
90 					Idx *equiv_class_alloc,
91 					const unsigned char *name);
92 static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
93 				      bitset_t sbcset,
94 				      re_charset_t *mbcset,
95 				      Idx *char_class_alloc,
96 				      const unsigned char *class_name,
97 				      reg_syntax_t syntax);
98 #else  /* not RE_ENABLE_I18N */
99 static reg_errcode_t build_equiv_class (bitset_t sbcset,
100 					const unsigned char *name);
101 static reg_errcode_t build_charclass (RE_TRANSLATE_TYPE trans,
102 				      bitset_t sbcset,
103 				      const unsigned char *class_name,
104 				      reg_syntax_t syntax);
105 #endif /* not RE_ENABLE_I18N */
106 static bin_tree_t *build_charclass_op (re_dfa_t *dfa,
107 				       RE_TRANSLATE_TYPE trans,
108 				       const unsigned char *class_name,
109 				       const unsigned char *extra,
110 				       bool non_match, reg_errcode_t *err);
111 static bin_tree_t *create_tree (re_dfa_t *dfa,
112 				bin_tree_t *left, bin_tree_t *right,
113 				re_token_type_t type);
114 static bin_tree_t *create_token_tree (re_dfa_t *dfa,
115 				      bin_tree_t *left, bin_tree_t *right,
116 				      const re_token_t *token);
117 static bin_tree_t *duplicate_tree (const bin_tree_t *src, re_dfa_t *dfa);
118 static void free_token (re_token_t *node);
119 static reg_errcode_t free_tree (void *extra, bin_tree_t *node);
120 static reg_errcode_t mark_opt_subexp (void *extra, bin_tree_t *node);
121 
122 /* This table gives an error message for each of the error codes listed
123    in regex.h.  Obviously the order here has to be same as there.
124    POSIX doesn't require that we do anything for REG_NOERROR,
125    but why not be nice?  */
126 
127 static const char __re_error_msgid[] =
128   {
129 #define REG_NOERROR_IDX	0
130     gettext_noop ("Success")	/* REG_NOERROR */
131     "\0"
132 #define REG_NOMATCH_IDX (REG_NOERROR_IDX + sizeof "Success")
133     gettext_noop ("No match")	/* REG_NOMATCH */
134     "\0"
135 #define REG_BADPAT_IDX	(REG_NOMATCH_IDX + sizeof "No match")
136     gettext_noop ("Invalid regular expression") /* REG_BADPAT */
137     "\0"
138 #define REG_ECOLLATE_IDX (REG_BADPAT_IDX + sizeof "Invalid regular expression")
139     gettext_noop ("Invalid collation character") /* REG_ECOLLATE */
140     "\0"
141 #define REG_ECTYPE_IDX	(REG_ECOLLATE_IDX + sizeof "Invalid collation character")
142     gettext_noop ("Invalid character class name") /* REG_ECTYPE */
143     "\0"
144 #define REG_EESCAPE_IDX	(REG_ECTYPE_IDX + sizeof "Invalid character class name")
145     gettext_noop ("Trailing backslash") /* REG_EESCAPE */
146     "\0"
147 #define REG_ESUBREG_IDX	(REG_EESCAPE_IDX + sizeof "Trailing backslash")
148     gettext_noop ("Invalid back reference") /* REG_ESUBREG */
149     "\0"
150 #define REG_EBRACK_IDX	(REG_ESUBREG_IDX + sizeof "Invalid back reference")
151     gettext_noop ("Unmatched [ or [^")	/* REG_EBRACK */
152     "\0"
153 #define REG_EPAREN_IDX	(REG_EBRACK_IDX + sizeof "Unmatched [ or [^")
154     gettext_noop ("Unmatched ( or \\(") /* REG_EPAREN */
155     "\0"
156 #define REG_EBRACE_IDX	(REG_EPAREN_IDX + sizeof "Unmatched ( or \\(")
157     gettext_noop ("Unmatched \\{") /* REG_EBRACE */
158     "\0"
159 #define REG_BADBR_IDX	(REG_EBRACE_IDX + sizeof "Unmatched \\{")
160     gettext_noop ("Invalid content of \\{\\}") /* REG_BADBR */
161     "\0"
162 #define REG_ERANGE_IDX	(REG_BADBR_IDX + sizeof "Invalid content of \\{\\}")
163     gettext_noop ("Invalid range end")	/* REG_ERANGE */
164     "\0"
165 #define REG_ESPACE_IDX	(REG_ERANGE_IDX + sizeof "Invalid range end")
166     gettext_noop ("Memory exhausted") /* REG_ESPACE */
167     "\0"
168 #define REG_BADRPT_IDX	(REG_ESPACE_IDX + sizeof "Memory exhausted")
169     gettext_noop ("Invalid preceding regular expression") /* REG_BADRPT */
170     "\0"
171 #define REG_EEND_IDX	(REG_BADRPT_IDX + sizeof "Invalid preceding regular expression")
172     gettext_noop ("Premature end of regular expression") /* REG_EEND */
173     "\0"
174 #define REG_ESIZE_IDX	(REG_EEND_IDX + sizeof "Premature end of regular expression")
175     gettext_noop ("Regular expression too big") /* REG_ESIZE */
176     "\0"
177 #define REG_ERPAREN_IDX	(REG_ESIZE_IDX + sizeof "Regular expression too big")
178     gettext_noop ("Unmatched ) or \\)") /* REG_ERPAREN */
179   };
180 
181 static const size_t __re_error_msgid_idx[] =
182   {
183     REG_NOERROR_IDX,
184     REG_NOMATCH_IDX,
185     REG_BADPAT_IDX,
186     REG_ECOLLATE_IDX,
187     REG_ECTYPE_IDX,
188     REG_EESCAPE_IDX,
189     REG_ESUBREG_IDX,
190     REG_EBRACK_IDX,
191     REG_EPAREN_IDX,
192     REG_EBRACE_IDX,
193     REG_BADBR_IDX,
194     REG_ERANGE_IDX,
195     REG_ESPACE_IDX,
196     REG_BADRPT_IDX,
197     REG_EEND_IDX,
198     REG_ESIZE_IDX,
199     REG_ERPAREN_IDX
200   };
201 
202 /* Entry points for GNU code.  */
203 
204 /* re_compile_pattern is the GNU regular expression compiler: it
205    compiles PATTERN (of length LENGTH) and puts the result in BUFP.
206    Returns 0 if the pattern was valid, otherwise an error string.
207 
208    Assumes the 'allocated' (and perhaps 'buffer') and 'translate' fields
209    are set in BUFP on entry.  */
210 
211 #ifdef _LIBC
212 const char *
213 re_compile_pattern (pattern, length, bufp)
214     const char *pattern;
215     size_t length;
216     struct re_pattern_buffer *bufp;
217 #else /* size_t might promote */
218 const char *
219 re_compile_pattern (const char *pattern, size_t length,
220 		    struct re_pattern_buffer *bufp)
221 #endif
222 {
223   reg_errcode_t ret;
224 
225   /* And GNU code determines whether or not to get register information
226      by passing null for the REGS argument to re_match, etc., not by
227      setting no_sub, unless RE_NO_SUB is set.  */
228   bufp->no_sub = !!(re_syntax_options & RE_NO_SUB);
229 
230   /* Match anchors at newline.  */
231   bufp->newline_anchor = 1;
232 
233   ret = re_compile_internal (bufp, pattern, length, re_syntax_options);
234 
235   if (!ret)
236     return NULL;
237   return gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
238 }
239 #ifdef _LIBC
240 weak_alias (__re_compile_pattern, re_compile_pattern)
241 #endif
242 
243 /* Set by 're_set_syntax' to the current regexp syntax to recognize.  Can
244    also be assigned to arbitrarily: each pattern buffer stores its own
245    syntax, so it can be changed between regex compilations.  */
246 /* This has no initializer because initialized variables in Emacs
247    become read-only after dumping.  */
248 reg_syntax_t re_syntax_options;
249 
250 
251 /* Specify the precise syntax of regexps for compilation.  This provides
252    for compatibility for various utilities which historically have
253    different, incompatible syntaxes.
254 
255    The argument SYNTAX is a bit mask comprised of the various bits
256    defined in regex.h.  We return the old syntax.  */
257 
258 reg_syntax_t
259 re_set_syntax (syntax)
260     reg_syntax_t syntax;
261 {
262   reg_syntax_t ret = re_syntax_options;
263 
264   re_syntax_options = syntax;
265   return ret;
266 }
267 #ifdef _LIBC
268 weak_alias (__re_set_syntax, re_set_syntax)
269 #endif
270 
271 int
272 re_compile_fastmap (bufp)
273     struct re_pattern_buffer *bufp;
274 {
275   re_dfa_t *dfa = bufp->buffer;
276   char *fastmap = bufp->fastmap;
277 
278   memset (fastmap, '\0', sizeof (char) * SBC_MAX);
279   re_compile_fastmap_iter (bufp, dfa->init_state, fastmap);
280   if (dfa->init_state != dfa->init_state_word)
281     re_compile_fastmap_iter (bufp, dfa->init_state_word, fastmap);
282   if (dfa->init_state != dfa->init_state_nl)
283     re_compile_fastmap_iter (bufp, dfa->init_state_nl, fastmap);
284   if (dfa->init_state != dfa->init_state_begbuf)
285     re_compile_fastmap_iter (bufp, dfa->init_state_begbuf, fastmap);
286   bufp->fastmap_accurate = 1;
287   return 0;
288 }
289 #ifdef _LIBC
290 weak_alias (__re_compile_fastmap, re_compile_fastmap)
291 #endif
292 
293 static inline void
294 __attribute ((always_inline))
295 re_set_fastmap (char *fastmap, bool icase, int ch)
296 {
297   fastmap[ch] = 1;
298   if (icase)
299     fastmap[tolower (ch)] = 1;
300 }
301 
302 /* Helper function for re_compile_fastmap.
303    Compile fastmap for the initial_state INIT_STATE.  */
304 
305 static void
306 re_compile_fastmap_iter (regex_t *bufp, const re_dfastate_t *init_state,
307 			 char *fastmap)
308 {
309   re_dfa_t *dfa = bufp->buffer;
310   Idx node_cnt;
311   bool icase = (dfa->mb_cur_max == 1 && (bufp->syntax & RE_ICASE));
312   for (node_cnt = 0; node_cnt < init_state->nodes.nelem; ++node_cnt)
313     {
314       Idx node = init_state->nodes.elems[node_cnt];
315       re_token_type_t type = dfa->nodes[node].type;
316 
317       if (type == CHARACTER)
318 	{
319 	  re_set_fastmap (fastmap, icase, dfa->nodes[node].opr.c);
320 #ifdef RE_ENABLE_I18N
321 	  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
322 	    {
323 	      unsigned char buf[MB_LEN_MAX];
324 	      unsigned char *p;
325 	      wchar_t wc;
326 	      mbstate_t state;
327 
328 	      p = buf;
329 	      *p++ = dfa->nodes[node].opr.c;
330 	      while (++node < dfa->nodes_len
331 		     &&	dfa->nodes[node].type == CHARACTER
332 		     && dfa->nodes[node].mb_partial)
333 		*p++ = dfa->nodes[node].opr.c;
334 	      memset (&state, '\0', sizeof (state));
335 	      if (__mbrtowc (&wc, (const char *) buf, p - buf,
336 			     &state) == p - buf
337 		  && (__wcrtomb ((char *) buf, towlower (wc), &state)
338 		      != (size_t) -1))
339 		re_set_fastmap (fastmap, false, buf[0]);
340 	    }
341 #endif
342 	}
343       else if (type == SIMPLE_BRACKET)
344 	{
345 	  int i, ch;
346 	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
347 	    {
348 	      int j;
349 	      bitset_word_t w = dfa->nodes[node].opr.sbcset[i];
350 	      for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
351 		if (w & ((bitset_word_t) 1 << j))
352 		  re_set_fastmap (fastmap, icase, ch);
353 	    }
354 	}
355 #ifdef RE_ENABLE_I18N
356       else if (type == COMPLEX_BRACKET)
357 	{
358 	  re_charset_t *cset = dfa->nodes[node].opr.mbcset;
359 	  Idx i;
360 
361 # ifdef _LIBC
362 	  /* See if we have to try all bytes which start multiple collation
363 	     elements.
364 	     e.g. In da_DK, we want to catch 'a' since "aa" is a valid
365 		  collation element, and don't catch 'b' since 'b' is
366 		  the only collation element which starts from 'b' (and
367 		  it is caught by SIMPLE_BRACKET).  */
368 	      if (_NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES) != 0
369 		  && (cset->ncoll_syms || cset->nranges))
370 		{
371 		  const int32_t *table = (const int32_t *)
372 		    _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
373 		  for (i = 0; i < SBC_MAX; ++i)
374 		    if (table[i] < 0)
375 		      re_set_fastmap (fastmap, icase, i);
376 		}
377 # endif /* _LIBC */
378 
379 	  /* See if we have to start the match at all multibyte characters,
380 	     i.e. where we would not find an invalid sequence.  This only
381 	     applies to multibyte character sets; for single byte character
382 	     sets, the SIMPLE_BRACKET again suffices.  */
383 	  if (dfa->mb_cur_max > 1
384 	      && (cset->nchar_classes || cset->non_match || cset->nranges
385 # ifdef _LIBC
386 		  || cset->nequiv_classes
387 # endif /* _LIBC */
388 		 ))
389 	    {
390 	      unsigned char c = 0;
391 	      do
392 		{
393 		  mbstate_t mbs;
394 		  memset (&mbs, 0, sizeof (mbs));
395 		  if (__mbrtowc (NULL, (char *) &c, 1, &mbs) == (size_t) -2)
396 		    re_set_fastmap (fastmap, false, (int) c);
397 		}
398 	      while (++c != 0);
399 	    }
400 
401 	  else
402 	    {
403 	      /* ... Else catch all bytes which can start the mbchars.  */
404 	      for (i = 0; i < cset->nmbchars; ++i)
405 		{
406 		  char buf[256];
407 		  mbstate_t state;
408 		  memset (&state, '\0', sizeof (state));
409 		  if (__wcrtomb (buf, cset->mbchars[i], &state) != (size_t) -1)
410 		    re_set_fastmap (fastmap, icase, *(unsigned char *) buf);
411 		  if ((bufp->syntax & RE_ICASE) && dfa->mb_cur_max > 1)
412 		    {
413 		      if (__wcrtomb (buf, towlower (cset->mbchars[i]), &state)
414 			  != (size_t) -1)
415 			re_set_fastmap (fastmap, false, *(unsigned char *) buf);
416 		    }
417 		}
418 	    }
419 	}
420 #endif /* RE_ENABLE_I18N */
421       else if (type == OP_PERIOD
422 #ifdef RE_ENABLE_I18N
423 	       || type == OP_UTF8_PERIOD
424 #endif /* RE_ENABLE_I18N */
425 	       || type == END_OF_RE)
426 	{
427 	  memset (fastmap, '\1', sizeof (char) * SBC_MAX);
428 	  if (type == END_OF_RE)
429 	    bufp->can_be_null = 1;
430 	  return;
431 	}
432     }
433 }
434 
435 /* Entry point for POSIX code.  */
436 /* regcomp takes a regular expression as a string and compiles it.
437 
438    PREG is a regex_t *.  We do not expect any fields to be initialized,
439    since POSIX says we shouldn't.  Thus, we set
440 
441      'buffer' to the compiled pattern;
442      'used' to the length of the compiled pattern;
443      'syntax' to RE_SYNTAX_POSIX_EXTENDED if the
444        REG_EXTENDED bit in CFLAGS is set; otherwise, to
445        RE_SYNTAX_POSIX_BASIC;
446      'newline_anchor' to REG_NEWLINE being set in CFLAGS;
447      'fastmap' to an allocated space for the fastmap;
448      'fastmap_accurate' to zero;
449      're_nsub' to the number of subexpressions in PATTERN.
450 
451    PATTERN is the address of the pattern string.
452 
453    CFLAGS is a series of bits which affect compilation.
454 
455      If REG_EXTENDED is set, we use POSIX extended syntax; otherwise, we
456      use POSIX basic syntax.
457 
458      If REG_NEWLINE is set, then . and [^...] don't match newline.
459      Also, regexec will try a match beginning after every newline.
460 
461      If REG_ICASE is set, then we considers upper- and lowercase
462      versions of letters to be equivalent when matching.
463 
464      If REG_NOSUB is set, then when PREG is passed to regexec, that
465      routine will report only success or failure, and nothing about the
466      registers.
467 
468    It returns 0 if it succeeds, nonzero if it doesn't.  (See regex.h for
469    the return codes and their meanings.)  */
470 
471 int
472 regcomp (preg, pattern, cflags)
473     regex_t *_Restrict_ preg;
474     const char *_Restrict_ pattern;
475     int cflags;
476 {
477   reg_errcode_t ret;
478   reg_syntax_t syntax = ((cflags & REG_EXTENDED) ? RE_SYNTAX_POSIX_EXTENDED
479 			 : RE_SYNTAX_POSIX_BASIC);
480 
481   preg->buffer = NULL;
482   preg->allocated = 0;
483   preg->used = 0;
484 
485   /* Try to allocate space for the fastmap.  */
486   preg->fastmap = re_malloc (char, SBC_MAX);
487   if (BE (preg->fastmap == NULL, 0))
488     return REG_ESPACE;
489 
490   syntax |= (cflags & REG_ICASE) ? RE_ICASE : 0;
491 
492   /* If REG_NEWLINE is set, newlines are treated differently.  */
493   if (cflags & REG_NEWLINE)
494     { /* REG_NEWLINE implies neither . nor [^...] match newline.  */
495       syntax &= ~RE_DOT_NEWLINE;
496       syntax |= RE_HAT_LISTS_NOT_NEWLINE;
497       /* It also changes the matching behavior.  */
498       preg->newline_anchor = 1;
499     }
500   else
501     preg->newline_anchor = 0;
502   preg->no_sub = !!(cflags & REG_NOSUB);
503   preg->translate = NULL;
504 
505   ret = re_compile_internal (preg, pattern, strlen (pattern), syntax);
506 
507   /* POSIX doesn't distinguish between an unmatched open-group and an
508      unmatched close-group: both are REG_EPAREN.  */
509   if (ret == REG_ERPAREN)
510     ret = REG_EPAREN;
511 
512   /* We have already checked preg->fastmap != NULL.  */
513   if (BE (ret == REG_NOERROR, 1))
514     /* Compute the fastmap now, since regexec cannot modify the pattern
515        buffer.  This function never fails in this implementation.  */
516     (void) re_compile_fastmap (preg);
517   else
518     {
519       /* Some error occurred while compiling the expression.  */
520       re_free (preg->fastmap);
521       preg->fastmap = NULL;
522     }
523 
524   return (int) ret;
525 }
526 #ifdef _LIBC
527 weak_alias (__regcomp, regcomp)
528 #endif
529 
530 /* Returns a message corresponding to an error code, ERRCODE, returned
531    from either regcomp or regexec.   We don't use PREG here.  */
532 
533 #ifdef _LIBC
534 size_t
535 regerror (errcode, preg, errbuf, errbuf_size)
536     int errcode;
537     const regex_t *_Restrict_ preg;
538     char *_Restrict_ errbuf;
539     size_t errbuf_size;
540 #else /* size_t might promote */
541 size_t
542 regerror (int errcode, const regex_t *_Restrict_ preg _UNUSED_PARAMETER_,
543 	  char *_Restrict_ errbuf, size_t errbuf_size)
544 #endif
545 {
546   const char *msg;
547   size_t msg_size;
548 
549   if (BE (errcode < 0
550 	  || errcode >= (int) (sizeof (__re_error_msgid_idx)
551 			       / sizeof (__re_error_msgid_idx[0])), 0))
552     /* Only error codes returned by the rest of the code should be passed
553        to this routine.  If we are given anything else, or if other regex
554        code generates an invalid error code, then the program has a bug.
555        Dump core so we can fix it.  */
556     abort ();
557 
558   msg = gettext (__re_error_msgid + __re_error_msgid_idx[errcode]);
559 
560   msg_size = strlen (msg) + 1; /* Includes the null.  */
561 
562   if (BE (errbuf_size != 0, 1))
563     {
564       size_t cpy_size = msg_size;
565       if (BE (msg_size > errbuf_size, 0))
566 	{
567 	  cpy_size = errbuf_size - 1;
568 	  errbuf[cpy_size] = '\0';
569 	}
570       memcpy (errbuf, msg, cpy_size);
571     }
572 
573   return msg_size;
574 }
575 #ifdef _LIBC
576 weak_alias (__regerror, regerror)
577 #endif
578 
579 
580 #ifdef RE_ENABLE_I18N
581 /* This static array is used for the map to single-byte characters when
582    UTF-8 is used.  Otherwise we would allocate memory just to initialize
583    it the same all the time.  UTF-8 is the preferred encoding so this is
584    a worthwhile optimization.  */
585 static const bitset_t utf8_sb_map =
586 {
587   /* Set the first 128 bits.  */
588 # ifdef __GNUC__
589   [0 ... 0x80 / BITSET_WORD_BITS - 1] = BITSET_WORD_MAX
590 # else
591 #  if 4 * BITSET_WORD_BITS < ASCII_CHARS
592 #   error "bitset_word_t is narrower than 32 bits"
593 #  elif 3 * BITSET_WORD_BITS < ASCII_CHARS
594   BITSET_WORD_MAX, BITSET_WORD_MAX, BITSET_WORD_MAX,
595 #  elif 2 * BITSET_WORD_BITS < ASCII_CHARS
596   BITSET_WORD_MAX, BITSET_WORD_MAX,
597 #  elif 1 * BITSET_WORD_BITS < ASCII_CHARS
598   BITSET_WORD_MAX,
599 #  endif
600   (BITSET_WORD_MAX
601    >> (SBC_MAX % BITSET_WORD_BITS == 0
602        ? 0
603        : BITSET_WORD_BITS - SBC_MAX % BITSET_WORD_BITS))
604 # endif
605 };
606 #endif
607 
608 
609 static void
610 free_dfa_content (re_dfa_t *dfa)
611 {
612   Idx i, j;
613 
614   if (dfa->nodes)
615     for (i = 0; i < dfa->nodes_len; ++i)
616       free_token (dfa->nodes + i);
617   re_free (dfa->nexts);
618   for (i = 0; i < dfa->nodes_len; ++i)
619     {
620       if (dfa->eclosures != NULL)
621 	re_node_set_free (dfa->eclosures + i);
622       if (dfa->inveclosures != NULL)
623 	re_node_set_free (dfa->inveclosures + i);
624       if (dfa->edests != NULL)
625 	re_node_set_free (dfa->edests + i);
626     }
627   re_free (dfa->edests);
628   re_free (dfa->eclosures);
629   re_free (dfa->inveclosures);
630   re_free (dfa->nodes);
631 
632   if (dfa->state_table)
633     for (i = 0; i <= dfa->state_hash_mask; ++i)
634       {
635 	struct re_state_table_entry *entry = dfa->state_table + i;
636 	for (j = 0; j < entry->num; ++j)
637 	  {
638 	    re_dfastate_t *state = entry->array[j];
639 	    free_state (state);
640 	  }
641 	re_free (entry->array);
642       }
643   re_free (dfa->state_table);
644 #ifdef RE_ENABLE_I18N
645   if (dfa->sb_char != utf8_sb_map)
646     re_free (dfa->sb_char);
647 #endif
648   re_free (dfa->subexp_map);
649 #ifdef DEBUG
650   re_free (dfa->re_str);
651 #endif
652 
653   re_free (dfa);
654 }
655 
656 
657 /* Free dynamically allocated space used by PREG.  */
658 
659 void
660 regfree (preg)
661     regex_t *preg;
662 {
663   re_dfa_t *dfa = preg->buffer;
664   if (BE (dfa != NULL, 1))
665     free_dfa_content (dfa);
666   preg->buffer = NULL;
667   preg->allocated = 0;
668 
669   re_free (preg->fastmap);
670   preg->fastmap = NULL;
671 
672   re_free (preg->translate);
673   preg->translate = NULL;
674 }
675 #ifdef _LIBC
676 weak_alias (__regfree, regfree)
677 #endif
678 
679 /* Entry points compatible with 4.2 BSD regex library.  We don't define
680    them unless specifically requested.  */
681 
682 #if defined _REGEX_RE_COMP || defined _LIBC
683 
684 /* BSD has one and only one pattern buffer.  */
685 static struct re_pattern_buffer re_comp_buf;
686 
687 char *
688 # ifdef _LIBC
689 /* Make these definitions weak in libc, so POSIX programs can redefine
690    these names if they don't use our functions, and still use
691    regcomp/regexec above without link errors.  */
692 weak_function
693 # endif
694 re_comp (s)
695      const char *s;
696 {
697   reg_errcode_t ret;
698   char *fastmap;
699 
700   if (!s)
701     {
702       if (!re_comp_buf.buffer)
703 	return gettext ("No previous regular expression");
704       return 0;
705     }
706 
707   if (re_comp_buf.buffer)
708     {
709       fastmap = re_comp_buf.fastmap;
710       re_comp_buf.fastmap = NULL;
711       __regfree (&re_comp_buf);
712       memset (&re_comp_buf, '\0', sizeof (re_comp_buf));
713       re_comp_buf.fastmap = fastmap;
714     }
715 
716   if (re_comp_buf.fastmap == NULL)
717     {
718       re_comp_buf.fastmap = (char *) malloc (SBC_MAX);
719       if (re_comp_buf.fastmap == NULL)
720 	return (char *) gettext (__re_error_msgid
721 				 + __re_error_msgid_idx[(int) REG_ESPACE]);
722     }
723 
724   /* Since 're_exec' always passes NULL for the 'regs' argument, we
725      don't need to initialize the pattern buffer fields which affect it.  */
726 
727   /* Match anchors at newlines.  */
728   re_comp_buf.newline_anchor = 1;
729 
730   ret = re_compile_internal (&re_comp_buf, s, strlen (s), re_syntax_options);
731 
732   if (!ret)
733     return NULL;
734 
735   /* Yes, we're discarding 'const' here if !HAVE_LIBINTL.  */
736   return (char *) gettext (__re_error_msgid + __re_error_msgid_idx[(int) ret]);
737 }
738 
739 #ifdef _LIBC
740 libc_freeres_fn (free_mem)
741 {
742   __regfree (&re_comp_buf);
743 }
744 #endif
745 
746 #endif /* _REGEX_RE_COMP */
747 
748 /* Internal entry point.
749    Compile the regular expression PATTERN, whose length is LENGTH.
750    SYNTAX indicate regular expression's syntax.  */
751 
752 static reg_errcode_t
753 re_compile_internal (regex_t *preg, const char * pattern, size_t length,
754 		     reg_syntax_t syntax)
755 {
756   reg_errcode_t err = REG_NOERROR;
757   re_dfa_t *dfa;
758   re_string_t regexp;
759 
760   /* Initialize the pattern buffer.  */
761   preg->fastmap_accurate = 0;
762   preg->syntax = syntax;
763   preg->not_bol = preg->not_eol = 0;
764   preg->used = 0;
765   preg->re_nsub = 0;
766   preg->can_be_null = 0;
767   preg->regs_allocated = REGS_UNALLOCATED;
768 
769   /* Initialize the dfa.  */
770   dfa = preg->buffer;
771   if (BE (preg->allocated < sizeof (re_dfa_t), 0))
772     {
773       /* If zero allocated, but buffer is non-null, try to realloc
774 	 enough space.  This loses if buffer's address is bogus, but
775 	 that is the user's responsibility.  If ->buffer is NULL this
776 	 is a simple allocation.  */
777       dfa = re_realloc (preg->buffer, re_dfa_t, 1);
778       if (dfa == NULL)
779 	return REG_ESPACE;
780       preg->allocated = sizeof (re_dfa_t);
781       preg->buffer = dfa;
782     }
783   preg->used = sizeof (re_dfa_t);
784 
785   err = init_dfa (dfa, length);
786   if (BE (err != REG_NOERROR, 0))
787     {
788       free_dfa_content (dfa);
789       preg->buffer = NULL;
790       preg->allocated = 0;
791       return err;
792     }
793 #ifdef DEBUG
794   /* Note: length+1 will not overflow since it is checked in init_dfa.  */
795   dfa->re_str = re_malloc (char, length + 1);
796   strncpy (dfa->re_str, pattern, length + 1);
797 #endif
798 
799   __libc_lock_init (dfa->lock);
800 
801   err = re_string_construct (&regexp, pattern, length, preg->translate,
802 			     (syntax & RE_ICASE) != 0, dfa);
803   if (BE (err != REG_NOERROR, 0))
804     {
805     re_compile_internal_free_return:
806       free_workarea_compile (preg);
807       re_string_destruct (&regexp);
808       free_dfa_content (dfa);
809       preg->buffer = NULL;
810       preg->allocated = 0;
811       return err;
812     }
813 
814   /* Parse the regular expression, and build a structure tree.  */
815   preg->re_nsub = 0;
816   dfa->str_tree = parse (&regexp, preg, syntax, &err);
817   if (BE (dfa->str_tree == NULL, 0))
818     goto re_compile_internal_free_return;
819 
820   /* Analyze the tree and create the nfa.  */
821   err = analyze (preg);
822   if (BE (err != REG_NOERROR, 0))
823     goto re_compile_internal_free_return;
824 
825 #ifdef RE_ENABLE_I18N
826   /* If possible, do searching in single byte encoding to speed things up.  */
827   if (dfa->is_utf8 && !(syntax & RE_ICASE) && preg->translate == NULL)
828     optimize_utf8 (dfa);
829 #endif
830 
831   /* Then create the initial state of the dfa.  */
832   err = create_initial_state (dfa);
833 
834   /* Release work areas.  */
835   free_workarea_compile (preg);
836   re_string_destruct (&regexp);
837 
838   if (BE (err != REG_NOERROR, 0))
839     {
840       free_dfa_content (dfa);
841       preg->buffer = NULL;
842       preg->allocated = 0;
843     }
844 
845   return err;
846 }
847 
848 /* Initialize DFA.  We use the length of the regular expression PAT_LEN
849    as the initial length of some arrays.  */
850 
851 static reg_errcode_t
852 init_dfa (re_dfa_t *dfa, size_t pat_len)
853 {
854   __re_size_t table_size;
855 #ifndef _LIBC
856   const char *codeset_name;
857 #endif
858 #ifdef RE_ENABLE_I18N
859   size_t max_i18n_object_size = MAX (sizeof (wchar_t), sizeof (wctype_t));
860 #else
861   size_t max_i18n_object_size = 0;
862 #endif
863   size_t max_object_size =
864     MAX (sizeof (struct re_state_table_entry),
865 	 MAX (sizeof (re_token_t),
866 	      MAX (sizeof (re_node_set),
867 		   MAX (sizeof (regmatch_t),
868 			max_i18n_object_size))));
869 
870   memset (dfa, '\0', sizeof (re_dfa_t));
871 
872   /* Force allocation of str_tree_storage the first time.  */
873   dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
874 
875   /* Avoid overflows.  The extra "/ 2" is for the table_size doubling
876      calculation below, and for similar doubling calculations
877      elsewhere.  And it's <= rather than <, because some of the
878      doubling calculations add 1 afterwards.  */
879   if (BE (MIN (IDX_MAX, SIZE_MAX / max_object_size) / 2 <= pat_len, 0))
880     return REG_ESPACE;
881 
882   dfa->nodes_alloc = pat_len + 1;
883   dfa->nodes = re_malloc (re_token_t, dfa->nodes_alloc);
884 
885   /*  table_size = 2 ^ ceil(log pat_len) */
886   for (table_size = 1; ; table_size <<= 1)
887     if (table_size > pat_len)
888       break;
889 
890   dfa->state_table = calloc (sizeof (struct re_state_table_entry), table_size);
891   dfa->state_hash_mask = table_size - 1;
892 
893   dfa->mb_cur_max = MB_CUR_MAX;
894 #ifdef _LIBC
895   if (dfa->mb_cur_max == 6
896       && strcmp (_NL_CURRENT (LC_CTYPE, _NL_CTYPE_CODESET_NAME), "UTF-8") == 0)
897     dfa->is_utf8 = 1;
898   dfa->map_notascii = (_NL_CURRENT_WORD (LC_CTYPE, _NL_CTYPE_MAP_TO_NONASCII)
899 		       != 0);
900 #else
901   codeset_name = nl_langinfo (CODESET);
902   if (strcasecmp (codeset_name, "UTF-8") == 0
903       || strcasecmp (codeset_name, "UTF8") == 0)
904     dfa->is_utf8 = 1;
905 
906   /* We check exhaustively in the loop below if this charset is a
907      superset of ASCII.  */
908   dfa->map_notascii = 0;
909 #endif
910 
911 #ifdef RE_ENABLE_I18N
912   if (dfa->mb_cur_max > 1)
913     {
914       if (dfa->is_utf8)
915 	dfa->sb_char = (re_bitset_ptr_t) utf8_sb_map;
916       else
917 	{
918 	  int i, j, ch;
919 
920 	  dfa->sb_char = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
921 	  if (BE (dfa->sb_char == NULL, 0))
922 	    return REG_ESPACE;
923 
924 	  /* Set the bits corresponding to single byte chars.  */
925 	  for (i = 0, ch = 0; i < BITSET_WORDS; ++i)
926 	    for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
927 	      {
928 		wint_t wch = __btowc (ch);
929 		if (wch != WEOF)
930 		  dfa->sb_char[i] |= (bitset_word_t) 1 << j;
931 # ifndef _LIBC
932 		if (isascii (ch) && wch != ch)
933 		  dfa->map_notascii = 1;
934 # endif
935 	      }
936 	}
937     }
938 #endif
939 
940   if (BE (dfa->nodes == NULL || dfa->state_table == NULL, 0))
941     return REG_ESPACE;
942   return REG_NOERROR;
943 }
944 
945 /* Initialize WORD_CHAR table, which indicate which character is
946    "word".  In this case "word" means that it is the word construction
947    character used by some operators like "\<", "\>", etc.  */
948 
949 static void
950 internal_function
951 init_word_char (re_dfa_t *dfa)
952 {
953   dfa->word_ops_used = 1;
954   int i = 0;
955   int j;
956   int ch = 0;
957   if (BE (dfa->map_notascii == 0, 1))
958     {
959       if (BITSET_WORD_BITS == 64)
960 	{
961 	  dfa->word_char[0] = UINT64_C (0x03ff000000000000);
962 	  dfa->word_char[1] = UINT64_C (0x07fffffe87fffffe);
963 	  i = 2;
964 	}
965       else if (BITSET_WORD_BITS == 32)
966 	{
967 	  dfa->word_char[0] = UINT32_C (0x00000000);
968 	  dfa->word_char[1] = UINT32_C (0x03ff0000);
969 	  dfa->word_char[2] = UINT32_C (0x87fffffe);
970 	  dfa->word_char[3] = UINT32_C (0x07fffffe);
971 	  i = 4;
972 	}
973       else
974         goto general_case;
975       ch = 128;
976 
977       if (BE (dfa->is_utf8, 1))
978 	{
979 	  memset (&dfa->word_char[i], '\0', (SBC_MAX - ch) / 8);
980 	  return;
981 	}
982     }
983 
984  general_case:
985   for (; i < BITSET_WORDS; ++i)
986     for (j = 0; j < BITSET_WORD_BITS; ++j, ++ch)
987       if (isalnum (ch) || ch == '_')
988 	dfa->word_char[i] |= (bitset_word_t) 1 << j;
989 }
990 
991 /* Free the work area which are only used while compiling.  */
992 
993 static void
994 free_workarea_compile (regex_t *preg)
995 {
996   re_dfa_t *dfa = preg->buffer;
997   bin_tree_storage_t *storage, *next;
998   for (storage = dfa->str_tree_storage; storage; storage = next)
999     {
1000       next = storage->next;
1001       re_free (storage);
1002     }
1003   dfa->str_tree_storage = NULL;
1004   dfa->str_tree_storage_idx = BIN_TREE_STORAGE_SIZE;
1005   dfa->str_tree = NULL;
1006   re_free (dfa->org_indices);
1007   dfa->org_indices = NULL;
1008 }
1009 
1010 /* Create initial states for all contexts.  */
1011 
1012 static reg_errcode_t
1013 create_initial_state (re_dfa_t *dfa)
1014 {
1015   Idx first, i;
1016   reg_errcode_t err;
1017   re_node_set init_nodes;
1018 
1019   /* Initial states have the epsilon closure of the node which is
1020      the first node of the regular expression.  */
1021   first = dfa->str_tree->first->node_idx;
1022   dfa->init_node = first;
1023   err = re_node_set_init_copy (&init_nodes, dfa->eclosures + first);
1024   if (BE (err != REG_NOERROR, 0))
1025     return err;
1026 
1027   /* The back-references which are in initial states can epsilon transit,
1028      since in this case all of the subexpressions can be null.
1029      Then we add epsilon closures of the nodes which are the next nodes of
1030      the back-references.  */
1031   if (dfa->nbackref > 0)
1032     for (i = 0; i < init_nodes.nelem; ++i)
1033       {
1034 	Idx node_idx = init_nodes.elems[i];
1035 	re_token_type_t type = dfa->nodes[node_idx].type;
1036 
1037 	Idx clexp_idx;
1038 	if (type != OP_BACK_REF)
1039 	  continue;
1040 	for (clexp_idx = 0; clexp_idx < init_nodes.nelem; ++clexp_idx)
1041 	  {
1042 	    re_token_t *clexp_node;
1043 	    clexp_node = dfa->nodes + init_nodes.elems[clexp_idx];
1044 	    if (clexp_node->type == OP_CLOSE_SUBEXP
1045 		&& clexp_node->opr.idx == dfa->nodes[node_idx].opr.idx)
1046 	      break;
1047 	  }
1048 	if (clexp_idx == init_nodes.nelem)
1049 	  continue;
1050 
1051 	if (type == OP_BACK_REF)
1052 	  {
1053 	    Idx dest_idx = dfa->edests[node_idx].elems[0];
1054 	    if (!re_node_set_contains (&init_nodes, dest_idx))
1055 	      {
1056 		reg_errcode_t merge_err
1057                   = re_node_set_merge (&init_nodes, dfa->eclosures + dest_idx);
1058 		if (merge_err != REG_NOERROR)
1059 		  return merge_err;
1060 		i = 0;
1061 	      }
1062 	  }
1063       }
1064 
1065   /* It must be the first time to invoke acquire_state.  */
1066   dfa->init_state = re_acquire_state_context (&err, dfa, &init_nodes, 0);
1067   /* We don't check ERR here, since the initial state must not be NULL.  */
1068   if (BE (dfa->init_state == NULL, 0))
1069     return err;
1070   if (dfa->init_state->has_constraint)
1071     {
1072       dfa->init_state_word = re_acquire_state_context (&err, dfa, &init_nodes,
1073 						       CONTEXT_WORD);
1074       dfa->init_state_nl = re_acquire_state_context (&err, dfa, &init_nodes,
1075 						     CONTEXT_NEWLINE);
1076       dfa->init_state_begbuf = re_acquire_state_context (&err, dfa,
1077 							 &init_nodes,
1078 							 CONTEXT_NEWLINE
1079 							 | CONTEXT_BEGBUF);
1080       if (BE (dfa->init_state_word == NULL || dfa->init_state_nl == NULL
1081 	      || dfa->init_state_begbuf == NULL, 0))
1082 	return err;
1083     }
1084   else
1085     dfa->init_state_word = dfa->init_state_nl
1086       = dfa->init_state_begbuf = dfa->init_state;
1087 
1088   re_node_set_free (&init_nodes);
1089   return REG_NOERROR;
1090 }
1091 
1092 #ifdef RE_ENABLE_I18N
1093 /* If it is possible to do searching in single byte encoding instead of UTF-8
1094    to speed things up, set dfa->mb_cur_max to 1, clear is_utf8 and change
1095    DFA nodes where needed.  */
1096 
1097 static void
1098 optimize_utf8 (re_dfa_t *dfa)
1099 {
1100   Idx node;
1101   int i;
1102   bool mb_chars = false;
1103   bool has_period = false;
1104 
1105   for (node = 0; node < dfa->nodes_len; ++node)
1106     switch (dfa->nodes[node].type)
1107       {
1108       case CHARACTER:
1109 	if (dfa->nodes[node].opr.c >= ASCII_CHARS)
1110 	  mb_chars = true;
1111 	break;
1112       case ANCHOR:
1113 	switch (dfa->nodes[node].opr.ctx_type)
1114 	  {
1115 	  case LINE_FIRST:
1116 	  case LINE_LAST:
1117 	  case BUF_FIRST:
1118 	  case BUF_LAST:
1119 	    break;
1120 	  default:
1121 	    /* Word anchors etc. cannot be handled.  It's okay to test
1122 	       opr.ctx_type since constraints (for all DFA nodes) are
1123 	       created by ORing one or more opr.ctx_type values.  */
1124 	    return;
1125 	  }
1126 	break;
1127       case OP_PERIOD:
1128 	has_period = true;
1129 	break;
1130       case OP_BACK_REF:
1131       case OP_ALT:
1132       case END_OF_RE:
1133       case OP_DUP_ASTERISK:
1134       case OP_OPEN_SUBEXP:
1135       case OP_CLOSE_SUBEXP:
1136 	break;
1137       case COMPLEX_BRACKET:
1138 	return;
1139       case SIMPLE_BRACKET:
1140 	/* Just double check.  */
1141 	{
1142 	  int rshift = (ASCII_CHARS % BITSET_WORD_BITS == 0
1143 			? 0
1144 			: BITSET_WORD_BITS - ASCII_CHARS % BITSET_WORD_BITS);
1145 	  for (i = ASCII_CHARS / BITSET_WORD_BITS; i < BITSET_WORDS; ++i)
1146 	    {
1147 	      if (dfa->nodes[node].opr.sbcset[i] >> rshift != 0)
1148 		return;
1149 	      rshift = 0;
1150 	    }
1151 	}
1152 	break;
1153       default:
1154 	abort ();
1155       }
1156 
1157   if (mb_chars || has_period)
1158     for (node = 0; node < dfa->nodes_len; ++node)
1159       {
1160 	if (dfa->nodes[node].type == CHARACTER
1161 	    && dfa->nodes[node].opr.c >= ASCII_CHARS)
1162 	  dfa->nodes[node].mb_partial = 0;
1163 	else if (dfa->nodes[node].type == OP_PERIOD)
1164 	  dfa->nodes[node].type = OP_UTF8_PERIOD;
1165       }
1166 
1167   /* The search can be in single byte locale.  */
1168   dfa->mb_cur_max = 1;
1169   dfa->is_utf8 = 0;
1170   dfa->has_mb_node = dfa->nbackref > 0 || has_period;
1171 }
1172 #endif
1173 
1174 /* Analyze the structure tree, and calculate "first", "next", "edest",
1175    "eclosure", and "inveclosure".  */
1176 
1177 static reg_errcode_t
1178 analyze (regex_t *preg)
1179 {
1180   re_dfa_t *dfa = preg->buffer;
1181   reg_errcode_t ret;
1182 
1183   /* Allocate arrays.  */
1184   dfa->nexts = re_malloc (Idx, dfa->nodes_alloc);
1185   dfa->org_indices = re_malloc (Idx, dfa->nodes_alloc);
1186   dfa->edests = re_malloc (re_node_set, dfa->nodes_alloc);
1187   dfa->eclosures = re_malloc (re_node_set, dfa->nodes_alloc);
1188   if (BE (dfa->nexts == NULL || dfa->org_indices == NULL || dfa->edests == NULL
1189 	  || dfa->eclosures == NULL, 0))
1190     return REG_ESPACE;
1191 
1192   dfa->subexp_map = re_malloc (Idx, preg->re_nsub);
1193   if (dfa->subexp_map != NULL)
1194     {
1195       Idx i;
1196       for (i = 0; i < preg->re_nsub; i++)
1197 	dfa->subexp_map[i] = i;
1198       preorder (dfa->str_tree, optimize_subexps, dfa);
1199       for (i = 0; i < preg->re_nsub; i++)
1200 	if (dfa->subexp_map[i] != i)
1201 	  break;
1202       if (i == preg->re_nsub)
1203 	{
1204 	  free (dfa->subexp_map);
1205 	  dfa->subexp_map = NULL;
1206 	}
1207     }
1208 
1209   ret = postorder (dfa->str_tree, lower_subexps, preg);
1210   if (BE (ret != REG_NOERROR, 0))
1211     return ret;
1212   ret = postorder (dfa->str_tree, calc_first, dfa);
1213   if (BE (ret != REG_NOERROR, 0))
1214     return ret;
1215   preorder (dfa->str_tree, calc_next, dfa);
1216   ret = preorder (dfa->str_tree, link_nfa_nodes, dfa);
1217   if (BE (ret != REG_NOERROR, 0))
1218     return ret;
1219   ret = calc_eclosure (dfa);
1220   if (BE (ret != REG_NOERROR, 0))
1221     return ret;
1222 
1223   /* We only need this during the prune_impossible_nodes pass in regexec.c;
1224      skip it if p_i_n will not run, as calc_inveclosure can be quadratic.  */
1225   if ((!preg->no_sub && preg->re_nsub > 0 && dfa->has_plural_match)
1226       || dfa->nbackref)
1227     {
1228       dfa->inveclosures = re_malloc (re_node_set, dfa->nodes_len);
1229       if (BE (dfa->inveclosures == NULL, 0))
1230 	return REG_ESPACE;
1231       ret = calc_inveclosure (dfa);
1232     }
1233 
1234   return ret;
1235 }
1236 
1237 /* Our parse trees are very unbalanced, so we cannot use a stack to
1238    implement parse tree visits.  Instead, we use parent pointers and
1239    some hairy code in these two functions.  */
1240 static reg_errcode_t
1241 postorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
1242 	   void *extra)
1243 {
1244   bin_tree_t *node, *prev;
1245 
1246   for (node = root; ; )
1247     {
1248       /* Descend down the tree, preferably to the left (or to the right
1249 	 if that's the only child).  */
1250       while (node->left || node->right)
1251 	if (node->left)
1252 	  node = node->left;
1253 	else
1254 	  node = node->right;
1255 
1256       do
1257 	{
1258 	  reg_errcode_t err = fn (extra, node);
1259 	  if (BE (err != REG_NOERROR, 0))
1260 	    return err;
1261 	  if (node->parent == NULL)
1262 	    return REG_NOERROR;
1263 	  prev = node;
1264 	  node = node->parent;
1265 	}
1266       /* Go up while we have a node that is reached from the right.  */
1267       while (node->right == prev || node->right == NULL);
1268       node = node->right;
1269     }
1270 }
1271 
1272 static reg_errcode_t
1273 preorder (bin_tree_t *root, reg_errcode_t (fn (void *, bin_tree_t *)),
1274 	  void *extra)
1275 {
1276   bin_tree_t *node;
1277 
1278   for (node = root; ; )
1279     {
1280       reg_errcode_t err = fn (extra, node);
1281       if (BE (err != REG_NOERROR, 0))
1282 	return err;
1283 
1284       /* Go to the left node, or up and to the right.  */
1285       if (node->left)
1286 	node = node->left;
1287       else
1288 	{
1289 	  bin_tree_t *prev = NULL;
1290 	  while (node->right == prev || node->right == NULL)
1291 	    {
1292 	      prev = node;
1293 	      node = node->parent;
1294 	      if (!node)
1295 		return REG_NOERROR;
1296 	    }
1297 	  node = node->right;
1298 	}
1299     }
1300 }
1301 
1302 /* Optimization pass: if a SUBEXP is entirely contained, strip it and tell
1303    re_search_internal to map the inner one's opr.idx to this one's.  Adjust
1304    backreferences as well.  Requires a preorder visit.  */
1305 static reg_errcode_t
1306 optimize_subexps (void *extra, bin_tree_t *node)
1307 {
1308   re_dfa_t *dfa = (re_dfa_t *) extra;
1309 
1310   if (node->token.type == OP_BACK_REF && dfa->subexp_map)
1311     {
1312       int idx = node->token.opr.idx;
1313       node->token.opr.idx = dfa->subexp_map[idx];
1314       dfa->used_bkref_map |= 1 << node->token.opr.idx;
1315     }
1316 
1317   else if (node->token.type == SUBEXP
1318 	   && node->left && node->left->token.type == SUBEXP)
1319     {
1320       Idx other_idx = node->left->token.opr.idx;
1321 
1322       node->left = node->left->left;
1323       if (node->left)
1324 	node->left->parent = node;
1325 
1326       dfa->subexp_map[other_idx] = dfa->subexp_map[node->token.opr.idx];
1327       if (other_idx < BITSET_WORD_BITS)
1328 	dfa->used_bkref_map &= ~((bitset_word_t) 1 << other_idx);
1329     }
1330 
1331   return REG_NOERROR;
1332 }
1333 
1334 /* Lowering pass: Turn each SUBEXP node into the appropriate concatenation
1335    of OP_OPEN_SUBEXP, the body of the SUBEXP (if any) and OP_CLOSE_SUBEXP.  */
1336 static reg_errcode_t
1337 lower_subexps (void *extra, bin_tree_t *node)
1338 {
1339   regex_t *preg = (regex_t *) extra;
1340   reg_errcode_t err = REG_NOERROR;
1341 
1342   if (node->left && node->left->token.type == SUBEXP)
1343     {
1344       node->left = lower_subexp (&err, preg, node->left);
1345       if (node->left)
1346 	node->left->parent = node;
1347     }
1348   if (node->right && node->right->token.type == SUBEXP)
1349     {
1350       node->right = lower_subexp (&err, preg, node->right);
1351       if (node->right)
1352 	node->right->parent = node;
1353     }
1354 
1355   return err;
1356 }
1357 
1358 static bin_tree_t *
1359 lower_subexp (reg_errcode_t *err, regex_t *preg, bin_tree_t *node)
1360 {
1361   re_dfa_t *dfa = preg->buffer;
1362   bin_tree_t *body = node->left;
1363   bin_tree_t *op, *cls, *tree1, *tree;
1364 
1365   if (preg->no_sub
1366       /* We do not optimize empty subexpressions, because otherwise we may
1367 	 have bad CONCAT nodes with NULL children.  This is obviously not
1368 	 very common, so we do not lose much.  An example that triggers
1369 	 this case is the sed "script" /\(\)/x.  */
1370       && node->left != NULL
1371       && (node->token.opr.idx >= BITSET_WORD_BITS
1372 	  || !(dfa->used_bkref_map
1373 	       & ((bitset_word_t) 1 << node->token.opr.idx))))
1374     return node->left;
1375 
1376   /* Convert the SUBEXP node to the concatenation of an
1377      OP_OPEN_SUBEXP, the contents, and an OP_CLOSE_SUBEXP.  */
1378   op = create_tree (dfa, NULL, NULL, OP_OPEN_SUBEXP);
1379   cls = create_tree (dfa, NULL, NULL, OP_CLOSE_SUBEXP);
1380   tree1 = body ? create_tree (dfa, body, cls, CONCAT) : cls;
1381   tree = create_tree (dfa, op, tree1, CONCAT);
1382   if (BE (tree == NULL || tree1 == NULL || op == NULL || cls == NULL, 0))
1383     {
1384       *err = REG_ESPACE;
1385       return NULL;
1386     }
1387 
1388   op->token.opr.idx = cls->token.opr.idx = node->token.opr.idx;
1389   op->token.opt_subexp = cls->token.opt_subexp = node->token.opt_subexp;
1390   return tree;
1391 }
1392 
1393 /* Pass 1 in building the NFA: compute FIRST and create unlinked automaton
1394    nodes.  Requires a postorder visit.  */
1395 static reg_errcode_t
1396 calc_first (void *extra, bin_tree_t *node)
1397 {
1398   re_dfa_t *dfa = (re_dfa_t *) extra;
1399   if (node->token.type == CONCAT)
1400     {
1401       node->first = node->left->first;
1402       node->node_idx = node->left->node_idx;
1403     }
1404   else
1405     {
1406       node->first = node;
1407       node->node_idx = re_dfa_add_node (dfa, node->token);
1408       if (BE (node->node_idx == REG_MISSING, 0))
1409 	return REG_ESPACE;
1410       if (node->token.type == ANCHOR)
1411 	dfa->nodes[node->node_idx].constraint = node->token.opr.ctx_type;
1412     }
1413   return REG_NOERROR;
1414 }
1415 
1416 /* Pass 2: compute NEXT on the tree.  Preorder visit.  */
1417 static reg_errcode_t
1418 calc_next (void *extra _UNUSED_PARAMETER_, bin_tree_t *node)
1419 {
1420   switch (node->token.type)
1421     {
1422     case OP_DUP_ASTERISK:
1423       node->left->next = node;
1424       break;
1425     case CONCAT:
1426       node->left->next = node->right->first;
1427       node->right->next = node->next;
1428       break;
1429     default:
1430       if (node->left)
1431 	node->left->next = node->next;
1432       if (node->right)
1433 	node->right->next = node->next;
1434       break;
1435     }
1436   return REG_NOERROR;
1437 }
1438 
1439 /* Pass 3: link all DFA nodes to their NEXT node (any order will do).  */
1440 static reg_errcode_t
1441 link_nfa_nodes (void *extra, bin_tree_t *node)
1442 {
1443   re_dfa_t *dfa = (re_dfa_t *) extra;
1444   Idx idx = node->node_idx;
1445   reg_errcode_t err = REG_NOERROR;
1446 
1447   switch (node->token.type)
1448     {
1449     case CONCAT:
1450       break;
1451 
1452     case END_OF_RE:
1453       assert (node->next == NULL);
1454       break;
1455 
1456     case OP_DUP_ASTERISK:
1457     case OP_ALT:
1458       {
1459 	Idx left, right;
1460 	dfa->has_plural_match = 1;
1461 	if (node->left != NULL)
1462 	  left = node->left->first->node_idx;
1463 	else
1464 	  left = node->next->node_idx;
1465 	if (node->right != NULL)
1466 	  right = node->right->first->node_idx;
1467 	else
1468 	  right = node->next->node_idx;
1469 	assert (REG_VALID_INDEX (left));
1470 	assert (REG_VALID_INDEX (right));
1471 	err = re_node_set_init_2 (dfa->edests + idx, left, right);
1472       }
1473       break;
1474 
1475     case ANCHOR:
1476     case OP_OPEN_SUBEXP:
1477     case OP_CLOSE_SUBEXP:
1478       err = re_node_set_init_1 (dfa->edests + idx, node->next->node_idx);
1479       break;
1480 
1481     case OP_BACK_REF:
1482       dfa->nexts[idx] = node->next->node_idx;
1483       if (node->token.type == OP_BACK_REF)
1484 	err = re_node_set_init_1 (dfa->edests + idx, dfa->nexts[idx]);
1485       break;
1486 
1487     default:
1488       assert (!IS_EPSILON_NODE (node->token.type));
1489       dfa->nexts[idx] = node->next->node_idx;
1490       break;
1491     }
1492 
1493   return err;
1494 }
1495 
1496 /* Duplicate the epsilon closure of the node ROOT_NODE.
1497    Note that duplicated nodes have constraint INIT_CONSTRAINT in addition
1498    to their own constraint.  */
1499 
1500 static reg_errcode_t
1501 internal_function
1502 duplicate_node_closure (re_dfa_t *dfa, Idx top_org_node, Idx top_clone_node,
1503 			Idx root_node, unsigned int init_constraint)
1504 {
1505   Idx org_node, clone_node;
1506   bool ok;
1507   unsigned int constraint = init_constraint;
1508   for (org_node = top_org_node, clone_node = top_clone_node;;)
1509     {
1510       Idx org_dest, clone_dest;
1511       if (dfa->nodes[org_node].type == OP_BACK_REF)
1512 	{
1513 	  /* If the back reference epsilon-transit, its destination must
1514 	     also have the constraint.  Then duplicate the epsilon closure
1515 	     of the destination of the back reference, and store it in
1516 	     edests of the back reference.  */
1517 	  org_dest = dfa->nexts[org_node];
1518 	  re_node_set_empty (dfa->edests + clone_node);
1519 	  clone_dest = duplicate_node (dfa, org_dest, constraint);
1520 	  if (BE (clone_dest == REG_MISSING, 0))
1521 	    return REG_ESPACE;
1522 	  dfa->nexts[clone_node] = dfa->nexts[org_node];
1523 	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
1524 	  if (BE (! ok, 0))
1525 	    return REG_ESPACE;
1526 	}
1527       else if (dfa->edests[org_node].nelem == 0)
1528 	{
1529 	  /* In case of the node can't epsilon-transit, don't duplicate the
1530 	     destination and store the original destination as the
1531 	     destination of the node.  */
1532 	  dfa->nexts[clone_node] = dfa->nexts[org_node];
1533 	  break;
1534 	}
1535       else if (dfa->edests[org_node].nelem == 1)
1536 	{
1537 	  /* In case of the node can epsilon-transit, and it has only one
1538 	     destination.  */
1539 	  org_dest = dfa->edests[org_node].elems[0];
1540 	  re_node_set_empty (dfa->edests + clone_node);
1541 	  /* If the node is root_node itself, it means the epsilon closure
1542 	     has a loop.  Then tie it to the destination of the root_node.  */
1543 	  if (org_node == root_node && clone_node != org_node)
1544 	    {
1545 	      ok = re_node_set_insert (dfa->edests + clone_node, org_dest);
1546 	      if (BE (! ok, 0))
1547 	        return REG_ESPACE;
1548 	      break;
1549 	    }
1550 	  /* In case the node has another constraint, append it.  */
1551 	  constraint |= dfa->nodes[org_node].constraint;
1552 	  clone_dest = duplicate_node (dfa, org_dest, constraint);
1553 	  if (BE (clone_dest == REG_MISSING, 0))
1554 	    return REG_ESPACE;
1555 	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
1556 	  if (BE (! ok, 0))
1557 	    return REG_ESPACE;
1558 	}
1559       else /* dfa->edests[org_node].nelem == 2 */
1560 	{
1561 	  /* In case of the node can epsilon-transit, and it has two
1562 	     destinations. In the bin_tree_t and DFA, that's '|' and '*'.   */
1563 	  org_dest = dfa->edests[org_node].elems[0];
1564 	  re_node_set_empty (dfa->edests + clone_node);
1565 	  /* Search for a duplicated node which satisfies the constraint.  */
1566 	  clone_dest = search_duplicated_node (dfa, org_dest, constraint);
1567 	  if (clone_dest == REG_MISSING)
1568 	    {
1569 	      /* There is no such duplicated node, create a new one.  */
1570 	      reg_errcode_t err;
1571 	      clone_dest = duplicate_node (dfa, org_dest, constraint);
1572 	      if (BE (clone_dest == REG_MISSING, 0))
1573 		return REG_ESPACE;
1574 	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
1575 	      if (BE (! ok, 0))
1576 		return REG_ESPACE;
1577 	      err = duplicate_node_closure (dfa, org_dest, clone_dest,
1578 					    root_node, constraint);
1579 	      if (BE (err != REG_NOERROR, 0))
1580 		return err;
1581 	    }
1582 	  else
1583 	    {
1584 	      /* There is a duplicated node which satisfies the constraint,
1585 		 use it to avoid infinite loop.  */
1586 	      ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
1587 	      if (BE (! ok, 0))
1588 		return REG_ESPACE;
1589 	    }
1590 
1591 	  org_dest = dfa->edests[org_node].elems[1];
1592 	  clone_dest = duplicate_node (dfa, org_dest, constraint);
1593 	  if (BE (clone_dest == REG_MISSING, 0))
1594 	    return REG_ESPACE;
1595 	  ok = re_node_set_insert (dfa->edests + clone_node, clone_dest);
1596 	  if (BE (! ok, 0))
1597 	    return REG_ESPACE;
1598 	}
1599       org_node = org_dest;
1600       clone_node = clone_dest;
1601     }
1602   return REG_NOERROR;
1603 }
1604 
1605 /* Search for a node which is duplicated from the node ORG_NODE, and
1606    satisfies the constraint CONSTRAINT.  */
1607 
1608 static Idx
1609 search_duplicated_node (const re_dfa_t *dfa, Idx org_node,
1610 			unsigned int constraint)
1611 {
1612   Idx idx;
1613   for (idx = dfa->nodes_len - 1; dfa->nodes[idx].duplicated && idx > 0; --idx)
1614     {
1615       if (org_node == dfa->org_indices[idx]
1616 	  && constraint == dfa->nodes[idx].constraint)
1617 	return idx; /* Found.  */
1618     }
1619   return REG_MISSING; /* Not found.  */
1620 }
1621 
1622 /* Duplicate the node whose index is ORG_IDX and set the constraint CONSTRAINT.
1623    Return the index of the new node, or REG_MISSING if insufficient storage is
1624    available.  */
1625 
1626 static Idx
1627 duplicate_node (re_dfa_t *dfa, Idx org_idx, unsigned int constraint)
1628 {
1629   Idx dup_idx = re_dfa_add_node (dfa, dfa->nodes[org_idx]);
1630   if (BE (dup_idx != REG_MISSING, 1))
1631     {
1632       dfa->nodes[dup_idx].constraint = constraint;
1633       dfa->nodes[dup_idx].constraint |= dfa->nodes[org_idx].constraint;
1634       dfa->nodes[dup_idx].duplicated = 1;
1635 
1636       /* Store the index of the original node.  */
1637       dfa->org_indices[dup_idx] = org_idx;
1638     }
1639   return dup_idx;
1640 }
1641 
1642 static reg_errcode_t
1643 calc_inveclosure (re_dfa_t *dfa)
1644 {
1645   Idx src, idx;
1646   bool ok;
1647   for (idx = 0; idx < dfa->nodes_len; ++idx)
1648     re_node_set_init_empty (dfa->inveclosures + idx);
1649 
1650   for (src = 0; src < dfa->nodes_len; ++src)
1651     {
1652       Idx *elems = dfa->eclosures[src].elems;
1653       for (idx = 0; idx < dfa->eclosures[src].nelem; ++idx)
1654 	{
1655 	  ok = re_node_set_insert_last (dfa->inveclosures + elems[idx], src);
1656 	  if (BE (! ok, 0))
1657 	    return REG_ESPACE;
1658 	}
1659     }
1660 
1661   return REG_NOERROR;
1662 }
1663 
1664 /* Calculate "eclosure" for all the node in DFA.  */
1665 
1666 static reg_errcode_t
1667 calc_eclosure (re_dfa_t *dfa)
1668 {
1669   Idx node_idx;
1670   bool incomplete;
1671 #ifdef DEBUG
1672   assert (dfa->nodes_len > 0);
1673 #endif
1674   incomplete = false;
1675   /* For each nodes, calculate epsilon closure.  */
1676   for (node_idx = 0; ; ++node_idx)
1677     {
1678       reg_errcode_t err;
1679       re_node_set eclosure_elem;
1680       if (node_idx == dfa->nodes_len)
1681 	{
1682 	  if (!incomplete)
1683 	    break;
1684 	  incomplete = false;
1685 	  node_idx = 0;
1686 	}
1687 
1688 #ifdef DEBUG
1689       assert (dfa->eclosures[node_idx].nelem != REG_MISSING);
1690 #endif
1691 
1692       /* If we have already calculated, skip it.  */
1693       if (dfa->eclosures[node_idx].nelem != 0)
1694 	continue;
1695       /* Calculate epsilon closure of 'node_idx'.  */
1696       err = calc_eclosure_iter (&eclosure_elem, dfa, node_idx, true);
1697       if (BE (err != REG_NOERROR, 0))
1698 	return err;
1699 
1700       if (dfa->eclosures[node_idx].nelem == 0)
1701 	{
1702 	  incomplete = true;
1703 	  re_node_set_free (&eclosure_elem);
1704 	}
1705     }
1706   return REG_NOERROR;
1707 }
1708 
1709 /* Calculate epsilon closure of NODE.  */
1710 
1711 static reg_errcode_t
1712 calc_eclosure_iter (re_node_set *new_set, re_dfa_t *dfa, Idx node, bool root)
1713 {
1714   reg_errcode_t err;
1715   Idx i;
1716   re_node_set eclosure;
1717   bool ok;
1718   bool incomplete = false;
1719   err = re_node_set_alloc (&eclosure, dfa->edests[node].nelem + 1);
1720   if (BE (err != REG_NOERROR, 0))
1721     return err;
1722 
1723   /* This indicates that we are calculating this node now.
1724      We reference this value to avoid infinite loop.  */
1725   dfa->eclosures[node].nelem = REG_MISSING;
1726 
1727   /* If the current node has constraints, duplicate all nodes
1728      since they must inherit the constraints.  */
1729   if (dfa->nodes[node].constraint
1730       && dfa->edests[node].nelem
1731       && !dfa->nodes[dfa->edests[node].elems[0]].duplicated)
1732     {
1733       err = duplicate_node_closure (dfa, node, node, node,
1734 				    dfa->nodes[node].constraint);
1735       if (BE (err != REG_NOERROR, 0))
1736 	return err;
1737     }
1738 
1739   /* Expand each epsilon destination nodes.  */
1740   if (IS_EPSILON_NODE(dfa->nodes[node].type))
1741     for (i = 0; i < dfa->edests[node].nelem; ++i)
1742       {
1743 	re_node_set eclosure_elem;
1744 	Idx edest = dfa->edests[node].elems[i];
1745 	/* If calculating the epsilon closure of 'edest' is in progress,
1746 	   return intermediate result.  */
1747 	if (dfa->eclosures[edest].nelem == REG_MISSING)
1748 	  {
1749 	    incomplete = true;
1750 	    continue;
1751 	  }
1752 	/* If we haven't calculated the epsilon closure of 'edest' yet,
1753 	   calculate now. Otherwise use calculated epsilon closure.  */
1754 	if (dfa->eclosures[edest].nelem == 0)
1755 	  {
1756 	    err = calc_eclosure_iter (&eclosure_elem, dfa, edest, false);
1757 	    if (BE (err != REG_NOERROR, 0))
1758 	      return err;
1759 	  }
1760 	else
1761 	  eclosure_elem = dfa->eclosures[edest];
1762 	/* Merge the epsilon closure of 'edest'.  */
1763 	err = re_node_set_merge (&eclosure, &eclosure_elem);
1764 	if (BE (err != REG_NOERROR, 0))
1765 	  return err;
1766 	/* If the epsilon closure of 'edest' is incomplete,
1767 	   the epsilon closure of this node is also incomplete.  */
1768 	if (dfa->eclosures[edest].nelem == 0)
1769 	  {
1770 	    incomplete = true;
1771 	    re_node_set_free (&eclosure_elem);
1772 	  }
1773       }
1774 
1775   /* An epsilon closure includes itself.  */
1776   ok = re_node_set_insert (&eclosure, node);
1777   if (BE (! ok, 0))
1778     return REG_ESPACE;
1779   if (incomplete && !root)
1780     dfa->eclosures[node].nelem = 0;
1781   else
1782     dfa->eclosures[node] = eclosure;
1783   *new_set = eclosure;
1784   return REG_NOERROR;
1785 }
1786 
1787 /* Functions for token which are used in the parser.  */
1788 
1789 /* Fetch a token from INPUT.
1790    We must not use this function inside bracket expressions.  */
1791 
1792 static void
1793 internal_function
1794 fetch_token (re_token_t *result, re_string_t *input, reg_syntax_t syntax)
1795 {
1796   re_string_skip_bytes (input, peek_token (result, input, syntax));
1797 }
1798 
1799 /* Peek a token from INPUT, and return the length of the token.
1800    We must not use this function inside bracket expressions.  */
1801 
1802 static int
1803 internal_function
1804 peek_token (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
1805 {
1806   unsigned char c;
1807 
1808   if (re_string_eoi (input))
1809     {
1810       token->type = END_OF_RE;
1811       return 0;
1812     }
1813 
1814   c = re_string_peek_byte (input, 0);
1815   token->opr.c = c;
1816 
1817   token->word_char = 0;
1818 #ifdef RE_ENABLE_I18N
1819   token->mb_partial = 0;
1820   if (input->mb_cur_max > 1 &&
1821       !re_string_first_byte (input, re_string_cur_idx (input)))
1822     {
1823       token->type = CHARACTER;
1824       token->mb_partial = 1;
1825       return 1;
1826     }
1827 #endif
1828   if (c == '\\')
1829     {
1830       unsigned char c2;
1831       if (re_string_cur_idx (input) + 1 >= re_string_length (input))
1832 	{
1833 	  token->type = BACK_SLASH;
1834 	  return 1;
1835 	}
1836 
1837       c2 = re_string_peek_byte_case (input, 1);
1838       token->opr.c = c2;
1839       token->type = CHARACTER;
1840 #ifdef RE_ENABLE_I18N
1841       if (input->mb_cur_max > 1)
1842 	{
1843 	  wint_t wc = re_string_wchar_at (input,
1844 					  re_string_cur_idx (input) + 1);
1845 	  token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
1846 	}
1847       else
1848 #endif
1849 	token->word_char = IS_WORD_CHAR (c2) != 0;
1850 
1851       switch (c2)
1852 	{
1853 	case '|':
1854 	  if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_NO_BK_VBAR))
1855 	    token->type = OP_ALT;
1856 	  break;
1857 	case '1': case '2': case '3': case '4': case '5':
1858 	case '6': case '7': case '8': case '9':
1859 	  if (!(syntax & RE_NO_BK_REFS))
1860 	    {
1861 	      token->type = OP_BACK_REF;
1862 	      token->opr.idx = c2 - '1';
1863 	    }
1864 	  break;
1865 	case '<':
1866 	  if (!(syntax & RE_NO_GNU_OPS))
1867 	    {
1868 	      token->type = ANCHOR;
1869 	      token->opr.ctx_type = WORD_FIRST;
1870 	    }
1871 	  break;
1872 	case '>':
1873 	  if (!(syntax & RE_NO_GNU_OPS))
1874 	    {
1875 	      token->type = ANCHOR;
1876 	      token->opr.ctx_type = WORD_LAST;
1877 	    }
1878 	  break;
1879 	case 'b':
1880 	  if (!(syntax & RE_NO_GNU_OPS))
1881 	    {
1882 	      token->type = ANCHOR;
1883 	      token->opr.ctx_type = WORD_DELIM;
1884 	    }
1885 	  break;
1886 	case 'B':
1887 	  if (!(syntax & RE_NO_GNU_OPS))
1888 	    {
1889 	      token->type = ANCHOR;
1890 	      token->opr.ctx_type = NOT_WORD_DELIM;
1891 	    }
1892 	  break;
1893 	case 'w':
1894 	  if (!(syntax & RE_NO_GNU_OPS))
1895 	    token->type = OP_WORD;
1896 	  break;
1897 	case 'W':
1898 	  if (!(syntax & RE_NO_GNU_OPS))
1899 	    token->type = OP_NOTWORD;
1900 	  break;
1901 	case 's':
1902 	  if (!(syntax & RE_NO_GNU_OPS))
1903 	    token->type = OP_SPACE;
1904 	  break;
1905 	case 'S':
1906 	  if (!(syntax & RE_NO_GNU_OPS))
1907 	    token->type = OP_NOTSPACE;
1908 	  break;
1909 	case '`':
1910 	  if (!(syntax & RE_NO_GNU_OPS))
1911 	    {
1912 	      token->type = ANCHOR;
1913 	      token->opr.ctx_type = BUF_FIRST;
1914 	    }
1915 	  break;
1916 	case '\'':
1917 	  if (!(syntax & RE_NO_GNU_OPS))
1918 	    {
1919 	      token->type = ANCHOR;
1920 	      token->opr.ctx_type = BUF_LAST;
1921 	    }
1922 	  break;
1923 	case '(':
1924 	  if (!(syntax & RE_NO_BK_PARENS))
1925 	    token->type = OP_OPEN_SUBEXP;
1926 	  break;
1927 	case ')':
1928 	  if (!(syntax & RE_NO_BK_PARENS))
1929 	    token->type = OP_CLOSE_SUBEXP;
1930 	  break;
1931 	case '+':
1932 	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
1933 	    token->type = OP_DUP_PLUS;
1934 	  break;
1935 	case '?':
1936 	  if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_BK_PLUS_QM))
1937 	    token->type = OP_DUP_QUESTION;
1938 	  break;
1939 	case '{':
1940 	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
1941 	    token->type = OP_OPEN_DUP_NUM;
1942 	  break;
1943 	case '}':
1944 	  if ((syntax & RE_INTERVALS) && (!(syntax & RE_NO_BK_BRACES)))
1945 	    token->type = OP_CLOSE_DUP_NUM;
1946 	  break;
1947 	default:
1948 	  break;
1949 	}
1950       return 2;
1951     }
1952 
1953   token->type = CHARACTER;
1954 #ifdef RE_ENABLE_I18N
1955   if (input->mb_cur_max > 1)
1956     {
1957       wint_t wc = re_string_wchar_at (input, re_string_cur_idx (input));
1958       token->word_char = IS_WIDE_WORD_CHAR (wc) != 0;
1959     }
1960   else
1961 #endif
1962     token->word_char = IS_WORD_CHAR (token->opr.c);
1963 
1964   switch (c)
1965     {
1966     case '\n':
1967       if (syntax & RE_NEWLINE_ALT)
1968 	token->type = OP_ALT;
1969       break;
1970     case '|':
1971       if (!(syntax & RE_LIMITED_OPS) && (syntax & RE_NO_BK_VBAR))
1972 	token->type = OP_ALT;
1973       break;
1974     case '*':
1975       token->type = OP_DUP_ASTERISK;
1976       break;
1977     case '+':
1978       if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
1979 	token->type = OP_DUP_PLUS;
1980       break;
1981     case '?':
1982       if (!(syntax & RE_LIMITED_OPS) && !(syntax & RE_BK_PLUS_QM))
1983 	token->type = OP_DUP_QUESTION;
1984       break;
1985     case '{':
1986       if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1987 	token->type = OP_OPEN_DUP_NUM;
1988       break;
1989     case '}':
1990       if ((syntax & RE_INTERVALS) && (syntax & RE_NO_BK_BRACES))
1991 	token->type = OP_CLOSE_DUP_NUM;
1992       break;
1993     case '(':
1994       if (syntax & RE_NO_BK_PARENS)
1995 	token->type = OP_OPEN_SUBEXP;
1996       break;
1997     case ')':
1998       if (syntax & RE_NO_BK_PARENS)
1999 	token->type = OP_CLOSE_SUBEXP;
2000       break;
2001     case '[':
2002       token->type = OP_OPEN_BRACKET;
2003       break;
2004     case '.':
2005       token->type = OP_PERIOD;
2006       break;
2007     case '^':
2008       if (!(syntax & (RE_CONTEXT_INDEP_ANCHORS | RE_CARET_ANCHORS_HERE)) &&
2009 	  re_string_cur_idx (input) != 0)
2010 	{
2011 	  char prev = re_string_peek_byte (input, -1);
2012 	  if (!(syntax & RE_NEWLINE_ALT) || prev != '\n')
2013 	    break;
2014 	}
2015       token->type = ANCHOR;
2016       token->opr.ctx_type = LINE_FIRST;
2017       break;
2018     case '$':
2019       if (!(syntax & RE_CONTEXT_INDEP_ANCHORS) &&
2020 	  re_string_cur_idx (input) + 1 != re_string_length (input))
2021 	{
2022 	  re_token_t next;
2023 	  re_string_skip_bytes (input, 1);
2024 	  peek_token (&next, input, syntax);
2025 	  re_string_skip_bytes (input, -1);
2026 	  if (next.type != OP_ALT && next.type != OP_CLOSE_SUBEXP)
2027 	    break;
2028 	}
2029       token->type = ANCHOR;
2030       token->opr.ctx_type = LINE_LAST;
2031       break;
2032     default:
2033       break;
2034     }
2035   return 1;
2036 }
2037 
2038 /* Peek a token from INPUT, and return the length of the token.
2039    We must not use this function out of bracket expressions.  */
2040 
2041 static int
2042 internal_function
2043 peek_token_bracket (re_token_t *token, re_string_t *input, reg_syntax_t syntax)
2044 {
2045   unsigned char c;
2046   if (re_string_eoi (input))
2047     {
2048       token->type = END_OF_RE;
2049       return 0;
2050     }
2051   c = re_string_peek_byte (input, 0);
2052   token->opr.c = c;
2053 
2054 #ifdef RE_ENABLE_I18N
2055   if (input->mb_cur_max > 1 &&
2056       !re_string_first_byte (input, re_string_cur_idx (input)))
2057     {
2058       token->type = CHARACTER;
2059       return 1;
2060     }
2061 #endif /* RE_ENABLE_I18N */
2062 
2063   if (c == '\\' && (syntax & RE_BACKSLASH_ESCAPE_IN_LISTS)
2064       && re_string_cur_idx (input) + 1 < re_string_length (input))
2065     {
2066       /* In this case, '\' escape a character.  */
2067       unsigned char c2;
2068       re_string_skip_bytes (input, 1);
2069       c2 = re_string_peek_byte (input, 0);
2070       token->opr.c = c2;
2071       token->type = CHARACTER;
2072       return 1;
2073     }
2074   if (c == '[') /* '[' is a special char in a bracket exps.  */
2075     {
2076       unsigned char c2;
2077       int token_len;
2078       if (re_string_cur_idx (input) + 1 < re_string_length (input))
2079 	c2 = re_string_peek_byte (input, 1);
2080       else
2081 	c2 = 0;
2082       token->opr.c = c2;
2083       token_len = 2;
2084       switch (c2)
2085 	{
2086 	case '.':
2087 	  token->type = OP_OPEN_COLL_ELEM;
2088 	  break;
2089 	case '=':
2090 	  token->type = OP_OPEN_EQUIV_CLASS;
2091 	  break;
2092 	case ':':
2093 	  if (syntax & RE_CHAR_CLASSES)
2094 	    {
2095 	      token->type = OP_OPEN_CHAR_CLASS;
2096 	      break;
2097 	    }
2098 	  /* else fall through.  */
2099 	default:
2100 	  token->type = CHARACTER;
2101 	  token->opr.c = c;
2102 	  token_len = 1;
2103 	  break;
2104 	}
2105       return token_len;
2106     }
2107   switch (c)
2108     {
2109     case '-':
2110       token->type = OP_CHARSET_RANGE;
2111       break;
2112     case ']':
2113       token->type = OP_CLOSE_BRACKET;
2114       break;
2115     case '^':
2116       token->type = OP_NON_MATCH_LIST;
2117       break;
2118     default:
2119       token->type = CHARACTER;
2120     }
2121   return 1;
2122 }
2123 
2124 /* Functions for parser.  */
2125 
2126 /* Entry point of the parser.
2127    Parse the regular expression REGEXP and return the structure tree.
2128    If an error occurs, ERR is set by error code, and return NULL.
2129    This function build the following tree, from regular expression <reg_exp>:
2130 	   CAT
2131 	   / \
2132 	  /   \
2133    <reg_exp>  EOR
2134 
2135    CAT means concatenation.
2136    EOR means end of regular expression.  */
2137 
2138 static bin_tree_t *
2139 parse (re_string_t *regexp, regex_t *preg, reg_syntax_t syntax,
2140        reg_errcode_t *err)
2141 {
2142   re_dfa_t *dfa = preg->buffer;
2143   bin_tree_t *tree, *eor, *root;
2144   re_token_t current_token;
2145   dfa->syntax = syntax;
2146   fetch_token (&current_token, regexp, syntax | RE_CARET_ANCHORS_HERE);
2147   tree = parse_reg_exp (regexp, preg, &current_token, syntax, 0, err);
2148   if (BE (*err != REG_NOERROR && tree == NULL, 0))
2149     return NULL;
2150   eor = create_tree (dfa, NULL, NULL, END_OF_RE);
2151   if (tree != NULL)
2152     root = create_tree (dfa, tree, eor, CONCAT);
2153   else
2154     root = eor;
2155   if (BE (eor == NULL || root == NULL, 0))
2156     {
2157       *err = REG_ESPACE;
2158       return NULL;
2159     }
2160   return root;
2161 }
2162 
2163 /* This function build the following tree, from regular expression
2164    <branch1>|<branch2>:
2165 	   ALT
2166 	   / \
2167 	  /   \
2168    <branch1> <branch2>
2169 
2170    ALT means alternative, which represents the operator '|'.  */
2171 
2172 static bin_tree_t *
2173 parse_reg_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
2174 	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
2175 {
2176   re_dfa_t *dfa = preg->buffer;
2177   bin_tree_t *tree, *branch = NULL;
2178   tree = parse_branch (regexp, preg, token, syntax, nest, err);
2179   if (BE (*err != REG_NOERROR && tree == NULL, 0))
2180     return NULL;
2181 
2182   while (token->type == OP_ALT)
2183     {
2184       fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
2185       if (token->type != OP_ALT && token->type != END_OF_RE
2186 	  && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
2187 	{
2188 	  branch = parse_branch (regexp, preg, token, syntax, nest, err);
2189 	  if (BE (*err != REG_NOERROR && branch == NULL, 0))
2190 	    return NULL;
2191 	}
2192       else
2193 	branch = NULL;
2194       tree = create_tree (dfa, tree, branch, OP_ALT);
2195       if (BE (tree == NULL, 0))
2196 	{
2197 	  *err = REG_ESPACE;
2198 	  return NULL;
2199 	}
2200     }
2201   return tree;
2202 }
2203 
2204 /* This function build the following tree, from regular expression
2205    <exp1><exp2>:
2206 	CAT
2207 	/ \
2208        /   \
2209    <exp1> <exp2>
2210 
2211    CAT means concatenation.  */
2212 
2213 static bin_tree_t *
2214 parse_branch (re_string_t *regexp, regex_t *preg, re_token_t *token,
2215 	      reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
2216 {
2217   bin_tree_t *tree, *expr;
2218   re_dfa_t *dfa = preg->buffer;
2219   tree = parse_expression (regexp, preg, token, syntax, nest, err);
2220   if (BE (*err != REG_NOERROR && tree == NULL, 0))
2221     return NULL;
2222 
2223   while (token->type != OP_ALT && token->type != END_OF_RE
2224 	 && (nest == 0 || token->type != OP_CLOSE_SUBEXP))
2225     {
2226       expr = parse_expression (regexp, preg, token, syntax, nest, err);
2227       if (BE (*err != REG_NOERROR && expr == NULL, 0))
2228 	{
2229 	  if (tree != NULL)
2230 	    postorder (tree, free_tree, NULL);
2231 	  return NULL;
2232 	}
2233       if (tree != NULL && expr != NULL)
2234 	{
2235 	  bin_tree_t *newtree = create_tree (dfa, tree, expr, CONCAT);
2236 	  if (newtree == NULL)
2237 	    {
2238 	      postorder (expr, free_tree, NULL);
2239 	      postorder (tree, free_tree, NULL);
2240 	      *err = REG_ESPACE;
2241 	      return NULL;
2242 	    }
2243 	  tree = newtree;
2244 	}
2245       else if (tree == NULL)
2246 	tree = expr;
2247       /* Otherwise expr == NULL, we don't need to create new tree.  */
2248     }
2249   return tree;
2250 }
2251 
2252 /* This function build the following tree, from regular expression a*:
2253 	 *
2254 	 |
2255 	 a
2256 */
2257 
2258 static bin_tree_t *
2259 parse_expression (re_string_t *regexp, regex_t *preg, re_token_t *token,
2260 		  reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
2261 {
2262   re_dfa_t *dfa = preg->buffer;
2263   bin_tree_t *tree;
2264   switch (token->type)
2265     {
2266     case CHARACTER:
2267       tree = create_token_tree (dfa, NULL, NULL, token);
2268       if (BE (tree == NULL, 0))
2269 	{
2270 	  *err = REG_ESPACE;
2271 	  return NULL;
2272 	}
2273 #ifdef RE_ENABLE_I18N
2274       if (dfa->mb_cur_max > 1)
2275 	{
2276 	  while (!re_string_eoi (regexp)
2277 		 && !re_string_first_byte (regexp, re_string_cur_idx (regexp)))
2278 	    {
2279 	      bin_tree_t *mbc_remain;
2280 	      fetch_token (token, regexp, syntax);
2281 	      mbc_remain = create_token_tree (dfa, NULL, NULL, token);
2282 	      tree = create_tree (dfa, tree, mbc_remain, CONCAT);
2283 	      if (BE (mbc_remain == NULL || tree == NULL, 0))
2284 		{
2285 		  *err = REG_ESPACE;
2286 		  return NULL;
2287 		}
2288 	    }
2289 	}
2290 #endif
2291       break;
2292     case OP_OPEN_SUBEXP:
2293       tree = parse_sub_exp (regexp, preg, token, syntax, nest + 1, err);
2294       if (BE (*err != REG_NOERROR && tree == NULL, 0))
2295 	return NULL;
2296       break;
2297     case OP_OPEN_BRACKET:
2298       tree = parse_bracket_exp (regexp, dfa, token, syntax, err);
2299       if (BE (*err != REG_NOERROR && tree == NULL, 0))
2300 	return NULL;
2301       break;
2302     case OP_BACK_REF:
2303       if (!BE (dfa->completed_bkref_map & (1 << token->opr.idx), 1))
2304 	{
2305 	  *err = REG_ESUBREG;
2306 	  return NULL;
2307 	}
2308       dfa->used_bkref_map |= 1 << token->opr.idx;
2309       tree = create_token_tree (dfa, NULL, NULL, token);
2310       if (BE (tree == NULL, 0))
2311 	{
2312 	  *err = REG_ESPACE;
2313 	  return NULL;
2314 	}
2315       ++dfa->nbackref;
2316       dfa->has_mb_node = 1;
2317       break;
2318     case OP_OPEN_DUP_NUM:
2319       if (syntax & RE_CONTEXT_INVALID_DUP)
2320 	{
2321 	  *err = REG_BADRPT;
2322 	  return NULL;
2323 	}
2324       /* FALLTHROUGH */
2325     case OP_DUP_ASTERISK:
2326     case OP_DUP_PLUS:
2327     case OP_DUP_QUESTION:
2328       if (syntax & RE_CONTEXT_INVALID_OPS)
2329 	{
2330 	  *err = REG_BADRPT;
2331 	  return NULL;
2332 	}
2333       else if (syntax & RE_CONTEXT_INDEP_OPS)
2334 	{
2335 	  fetch_token (token, regexp, syntax);
2336 	  return parse_expression (regexp, preg, token, syntax, nest, err);
2337 	}
2338       /* else fall through  */
2339     case OP_CLOSE_SUBEXP:
2340       if ((token->type == OP_CLOSE_SUBEXP) &&
2341 	  !(syntax & RE_UNMATCHED_RIGHT_PAREN_ORD))
2342 	{
2343 	  *err = REG_ERPAREN;
2344 	  return NULL;
2345 	}
2346       /* else fall through  */
2347     case OP_CLOSE_DUP_NUM:
2348       /* We treat it as a normal character.  */
2349 
2350       /* Then we can these characters as normal characters.  */
2351       token->type = CHARACTER;
2352       /* mb_partial and word_char bits should be initialized already
2353 	 by peek_token.  */
2354       tree = create_token_tree (dfa, NULL, NULL, token);
2355       if (BE (tree == NULL, 0))
2356 	{
2357 	  *err = REG_ESPACE;
2358 	  return NULL;
2359 	}
2360       break;
2361     case ANCHOR:
2362       if ((token->opr.ctx_type
2363 	   & (WORD_DELIM | NOT_WORD_DELIM | WORD_FIRST | WORD_LAST))
2364 	  && dfa->word_ops_used == 0)
2365 	init_word_char (dfa);
2366       if (token->opr.ctx_type == WORD_DELIM
2367 	  || token->opr.ctx_type == NOT_WORD_DELIM)
2368 	{
2369 	  bin_tree_t *tree_first, *tree_last;
2370 	  if (token->opr.ctx_type == WORD_DELIM)
2371 	    {
2372 	      token->opr.ctx_type = WORD_FIRST;
2373 	      tree_first = create_token_tree (dfa, NULL, NULL, token);
2374 	      token->opr.ctx_type = WORD_LAST;
2375 	    }
2376 	  else
2377 	    {
2378 	      token->opr.ctx_type = INSIDE_WORD;
2379 	      tree_first = create_token_tree (dfa, NULL, NULL, token);
2380 	      token->opr.ctx_type = INSIDE_NOTWORD;
2381 	    }
2382 	  tree_last = create_token_tree (dfa, NULL, NULL, token);
2383 	  tree = create_tree (dfa, tree_first, tree_last, OP_ALT);
2384 	  if (BE (tree_first == NULL || tree_last == NULL || tree == NULL, 0))
2385 	    {
2386 	      *err = REG_ESPACE;
2387 	      return NULL;
2388 	    }
2389 	}
2390       else
2391 	{
2392 	  tree = create_token_tree (dfa, NULL, NULL, token);
2393 	  if (BE (tree == NULL, 0))
2394 	    {
2395 	      *err = REG_ESPACE;
2396 	      return NULL;
2397 	    }
2398 	}
2399       /* We must return here, since ANCHORs can't be followed
2400 	 by repetition operators.
2401 	 eg. RE"^*" is invalid or "<ANCHOR(^)><CHAR(*)>",
2402 	     it must not be "<ANCHOR(^)><REPEAT(*)>".  */
2403       fetch_token (token, regexp, syntax);
2404       return tree;
2405     case OP_PERIOD:
2406       tree = create_token_tree (dfa, NULL, NULL, token);
2407       if (BE (tree == NULL, 0))
2408 	{
2409 	  *err = REG_ESPACE;
2410 	  return NULL;
2411 	}
2412       if (dfa->mb_cur_max > 1)
2413 	dfa->has_mb_node = 1;
2414       break;
2415     case OP_WORD:
2416     case OP_NOTWORD:
2417       tree = build_charclass_op (dfa, regexp->trans,
2418 				 (const unsigned char *) "alnum",
2419 				 (const unsigned char *) "_",
2420 				 token->type == OP_NOTWORD, err);
2421       if (BE (*err != REG_NOERROR && tree == NULL, 0))
2422 	return NULL;
2423       break;
2424     case OP_SPACE:
2425     case OP_NOTSPACE:
2426       tree = build_charclass_op (dfa, regexp->trans,
2427 				 (const unsigned char *) "space",
2428 				 (const unsigned char *) "",
2429 				 token->type == OP_NOTSPACE, err);
2430       if (BE (*err != REG_NOERROR && tree == NULL, 0))
2431 	return NULL;
2432       break;
2433     case OP_ALT:
2434     case END_OF_RE:
2435       return NULL;
2436     case BACK_SLASH:
2437       *err = REG_EESCAPE;
2438       return NULL;
2439     default:
2440       /* Must not happen?  */
2441 #ifdef DEBUG
2442       assert (0);
2443 #endif
2444       return NULL;
2445     }
2446   fetch_token (token, regexp, syntax);
2447 
2448   while (token->type == OP_DUP_ASTERISK || token->type == OP_DUP_PLUS
2449 	 || token->type == OP_DUP_QUESTION || token->type == OP_OPEN_DUP_NUM)
2450     {
2451       tree = parse_dup_op (tree, regexp, dfa, token, syntax, err);
2452       if (BE (*err != REG_NOERROR && tree == NULL, 0))
2453 	return NULL;
2454       /* In BRE consecutive duplications are not allowed.  */
2455       if ((syntax & RE_CONTEXT_INVALID_DUP)
2456 	  && (token->type == OP_DUP_ASTERISK
2457 	      || token->type == OP_OPEN_DUP_NUM))
2458 	{
2459 	  *err = REG_BADRPT;
2460 	  return NULL;
2461 	}
2462     }
2463 
2464   return tree;
2465 }
2466 
2467 /* This function build the following tree, from regular expression
2468    (<reg_exp>):
2469 	 SUBEXP
2470 	    |
2471 	<reg_exp>
2472 */
2473 
2474 static bin_tree_t *
2475 parse_sub_exp (re_string_t *regexp, regex_t *preg, re_token_t *token,
2476 	       reg_syntax_t syntax, Idx nest, reg_errcode_t *err)
2477 {
2478   re_dfa_t *dfa = preg->buffer;
2479   bin_tree_t *tree;
2480   size_t cur_nsub;
2481   cur_nsub = preg->re_nsub++;
2482 
2483   fetch_token (token, regexp, syntax | RE_CARET_ANCHORS_HERE);
2484 
2485   /* The subexpression may be a null string.  */
2486   if (token->type == OP_CLOSE_SUBEXP)
2487     tree = NULL;
2488   else
2489     {
2490       tree = parse_reg_exp (regexp, preg, token, syntax, nest, err);
2491       if (BE (*err == REG_NOERROR && token->type != OP_CLOSE_SUBEXP, 0))
2492 	{
2493 	  if (tree != NULL)
2494 	    postorder (tree, free_tree, NULL);
2495 	  *err = REG_EPAREN;
2496 	}
2497       if (BE (*err != REG_NOERROR, 0))
2498 	return NULL;
2499     }
2500 
2501   if (cur_nsub <= '9' - '1')
2502     dfa->completed_bkref_map |= 1 << cur_nsub;
2503 
2504   tree = create_tree (dfa, tree, NULL, SUBEXP);
2505   if (BE (tree == NULL, 0))
2506     {
2507       *err = REG_ESPACE;
2508       return NULL;
2509     }
2510   tree->token.opr.idx = cur_nsub;
2511   return tree;
2512 }
2513 
2514 /* This function parse repetition operators like "*", "+", "{1,3}" etc.  */
2515 
2516 static bin_tree_t *
2517 parse_dup_op (bin_tree_t *elem, re_string_t *regexp, re_dfa_t *dfa,
2518 	      re_token_t *token, reg_syntax_t syntax, reg_errcode_t *err)
2519 {
2520   bin_tree_t *tree = NULL, *old_tree = NULL;
2521   Idx i, start, end, start_idx = re_string_cur_idx (regexp);
2522   re_token_t start_token = *token;
2523 
2524   if (token->type == OP_OPEN_DUP_NUM)
2525     {
2526       end = 0;
2527       start = fetch_number (regexp, token, syntax);
2528       if (start == REG_MISSING)
2529 	{
2530 	  if (token->type == CHARACTER && token->opr.c == ',')
2531 	    start = 0; /* We treat "{,m}" as "{0,m}".  */
2532 	  else
2533 	    {
2534 	      *err = REG_BADBR; /* <re>{} is invalid.  */
2535 	      return NULL;
2536 	    }
2537 	}
2538       if (BE (start != REG_ERROR, 1))
2539 	{
2540 	  /* We treat "{n}" as "{n,n}".  */
2541 	  end = ((token->type == OP_CLOSE_DUP_NUM) ? start
2542 		 : ((token->type == CHARACTER && token->opr.c == ',')
2543 		    ? fetch_number (regexp, token, syntax) : REG_ERROR));
2544 	}
2545       if (BE (start == REG_ERROR || end == REG_ERROR, 0))
2546 	{
2547 	  /* Invalid sequence.  */
2548 	  if (BE (!(syntax & RE_INVALID_INTERVAL_ORD), 0))
2549 	    {
2550 	      if (token->type == END_OF_RE)
2551 		*err = REG_EBRACE;
2552 	      else
2553 		*err = REG_BADBR;
2554 
2555 	      return NULL;
2556 	    }
2557 
2558 	  /* If the syntax bit is set, rollback.  */
2559 	  re_string_set_index (regexp, start_idx);
2560 	  *token = start_token;
2561 	  token->type = CHARACTER;
2562 	  /* mb_partial and word_char bits should be already initialized by
2563 	     peek_token.  */
2564 	  return elem;
2565 	}
2566 
2567       if (BE ((end != REG_MISSING && start > end)
2568 	      || token->type != OP_CLOSE_DUP_NUM, 0))
2569 	{
2570 	  /* First number greater than second.  */
2571 	  *err = REG_BADBR;
2572 	  return NULL;
2573 	}
2574 
2575       if (BE (RE_DUP_MAX < (end == REG_MISSING ? start : end), 0))
2576 	{
2577 	  *err = REG_ESIZE;
2578 	  return NULL;
2579 	}
2580     }
2581   else
2582     {
2583       start = (token->type == OP_DUP_PLUS) ? 1 : 0;
2584       end = (token->type == OP_DUP_QUESTION) ? 1 : REG_MISSING;
2585     }
2586 
2587   fetch_token (token, regexp, syntax);
2588 
2589   if (BE (elem == NULL, 0))
2590     return NULL;
2591   if (BE (start == 0 && end == 0, 0))
2592     {
2593       postorder (elem, free_tree, NULL);
2594       return NULL;
2595     }
2596 
2597   /* Extract "<re>{n,m}" to "<re><re>...<re><re>{0,<m-n>}".  */
2598   if (BE (start > 0, 0))
2599     {
2600       tree = elem;
2601       for (i = 2; i <= start; ++i)
2602 	{
2603 	  elem = duplicate_tree (elem, dfa);
2604 	  tree = create_tree (dfa, tree, elem, CONCAT);
2605 	  if (BE (elem == NULL || tree == NULL, 0))
2606 	    goto parse_dup_op_espace;
2607 	}
2608 
2609       if (start == end)
2610 	return tree;
2611 
2612       /* Duplicate ELEM before it is marked optional.  */
2613       elem = duplicate_tree (elem, dfa);
2614       old_tree = tree;
2615     }
2616   else
2617     old_tree = NULL;
2618 
2619   if (elem->token.type == SUBEXP)
2620     postorder (elem, mark_opt_subexp, (void *) (long) elem->token.opr.idx);
2621 
2622   tree = create_tree (dfa, elem, NULL,
2623 		      (end == REG_MISSING ? OP_DUP_ASTERISK : OP_ALT));
2624   if (BE (tree == NULL, 0))
2625     goto parse_dup_op_espace;
2626 
2627 /* From gnulib's "intprops.h":
2628    True if the arithmetic type T is signed.  */
2629 #define TYPE_SIGNED(t) (! ((t) 0 < (t) -1))
2630 
2631   /* This loop is actually executed only when end != REG_MISSING,
2632      to rewrite <re>{0,n} as (<re>(<re>...<re>?)?)?...  We have
2633      already created the start+1-th copy.  */
2634   if (TYPE_SIGNED (Idx) || end != REG_MISSING)
2635     for (i = start + 2; i <= end; ++i)
2636       {
2637 	elem = duplicate_tree (elem, dfa);
2638 	tree = create_tree (dfa, tree, elem, CONCAT);
2639 	if (BE (elem == NULL || tree == NULL, 0))
2640 	  goto parse_dup_op_espace;
2641 
2642 	tree = create_tree (dfa, tree, NULL, OP_ALT);
2643 	if (BE (tree == NULL, 0))
2644 	  goto parse_dup_op_espace;
2645       }
2646 
2647   if (old_tree)
2648     tree = create_tree (dfa, old_tree, tree, CONCAT);
2649 
2650   return tree;
2651 
2652  parse_dup_op_espace:
2653   *err = REG_ESPACE;
2654   return NULL;
2655 }
2656 
2657 /* Size of the names for collating symbol/equivalence_class/character_class.
2658    I'm not sure, but maybe enough.  */
2659 #define BRACKET_NAME_BUF_SIZE 32
2660 
2661 #ifndef _LIBC
2662   /* Local function for parse_bracket_exp only used in case of NOT _LIBC.
2663      Build the range expression which starts from START_ELEM, and ends
2664      at END_ELEM.  The result are written to MBCSET and SBCSET.
2665      RANGE_ALLOC is the allocated size of mbcset->range_starts, and
2666      mbcset->range_ends, is a pointer argument since we may
2667      update it.  */
2668 
2669 static reg_errcode_t
2670 internal_function
2671 # ifdef RE_ENABLE_I18N
2672 build_range_exp (const reg_syntax_t syntax,
2673                  bitset_t sbcset,
2674                  re_charset_t *mbcset,
2675                  Idx *range_alloc,
2676                  const bracket_elem_t *start_elem,
2677                  const bracket_elem_t *end_elem)
2678 # else /* not RE_ENABLE_I18N */
2679 build_range_exp (const reg_syntax_t syntax,
2680                  bitset_t sbcset,
2681                  const bracket_elem_t *start_elem,
2682                  const bracket_elem_t *end_elem)
2683 # endif /* not RE_ENABLE_I18N */
2684 {
2685   unsigned int start_ch, end_ch;
2686   /* Equivalence Classes and Character Classes can't be a range start/end.  */
2687   if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
2688 	  || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
2689 	  0))
2690     return REG_ERANGE;
2691 
2692   /* We can handle no multi character collating elements without libc
2693      support.  */
2694   if (BE ((start_elem->type == COLL_SYM
2695 	   && strlen ((char *) start_elem->opr.name) > 1)
2696 	  || (end_elem->type == COLL_SYM
2697 	      && strlen ((char *) end_elem->opr.name) > 1), 0))
2698     return REG_ECOLLATE;
2699 
2700 # ifdef RE_ENABLE_I18N
2701   {
2702     wchar_t wc;
2703     wint_t start_wc;
2704     wint_t end_wc;
2705     wchar_t cmp_buf[6] = {L'\0', L'\0', L'\0', L'\0', L'\0', L'\0'};
2706 
2707     start_ch = ((start_elem->type == SB_CHAR) ? start_elem->opr.ch
2708 		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
2709 		   : 0));
2710     end_ch = ((end_elem->type == SB_CHAR) ? end_elem->opr.ch
2711 	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
2712 		 : 0));
2713     start_wc = ((start_elem->type == SB_CHAR || start_elem->type == COLL_SYM)
2714 		? __btowc (start_ch) : start_elem->opr.wch);
2715     end_wc = ((end_elem->type == SB_CHAR || end_elem->type == COLL_SYM)
2716 	      ? __btowc (end_ch) : end_elem->opr.wch);
2717     if (start_wc == WEOF || end_wc == WEOF)
2718       return REG_ECOLLATE;
2719     cmp_buf[0] = start_wc;
2720     cmp_buf[4] = end_wc;
2721 
2722     if (BE ((syntax & RE_NO_EMPTY_RANGES)
2723             && wcscoll (cmp_buf, cmp_buf + 4) > 0, 0))
2724       return REG_ERANGE;
2725 
2726     /* Got valid collation sequence values, add them as a new entry.
2727        However, for !_LIBC we have no collation elements: if the
2728        character set is single byte, the single byte character set
2729        that we build below suffices.  parse_bracket_exp passes
2730        no MBCSET if dfa->mb_cur_max == 1.  */
2731     if (mbcset)
2732       {
2733 	/* Check the space of the arrays.  */
2734 	if (BE (*range_alloc == mbcset->nranges, 0))
2735 	  {
2736 	    /* There is not enough space, need realloc.  */
2737 	    wchar_t *new_array_start, *new_array_end;
2738 	    Idx new_nranges;
2739 
2740 	    /* +1 in case of mbcset->nranges is 0.  */
2741 	    new_nranges = 2 * mbcset->nranges + 1;
2742 	    /* Use realloc since mbcset->range_starts and mbcset->range_ends
2743 	       are NULL if *range_alloc == 0.  */
2744 	    new_array_start = re_realloc (mbcset->range_starts, wchar_t,
2745 					  new_nranges);
2746 	    new_array_end = re_realloc (mbcset->range_ends, wchar_t,
2747 					new_nranges);
2748 
2749 	    if (BE (new_array_start == NULL || new_array_end == NULL, 0))
2750 	      return REG_ESPACE;
2751 
2752 	    mbcset->range_starts = new_array_start;
2753 	    mbcset->range_ends = new_array_end;
2754 	    *range_alloc = new_nranges;
2755 	  }
2756 
2757 	mbcset->range_starts[mbcset->nranges] = start_wc;
2758 	mbcset->range_ends[mbcset->nranges++] = end_wc;
2759       }
2760 
2761     /* Build the table for single byte characters.  */
2762     for (wc = 0; wc < SBC_MAX; ++wc)
2763       {
2764 	cmp_buf[2] = wc;
2765 	if (wcscoll (cmp_buf, cmp_buf + 2) <= 0
2766 	    && wcscoll (cmp_buf + 2, cmp_buf + 4) <= 0)
2767 	  bitset_set (sbcset, wc);
2768       }
2769   }
2770 # else /* not RE_ENABLE_I18N */
2771   {
2772     unsigned int ch;
2773     start_ch = ((start_elem->type == SB_CHAR ) ? start_elem->opr.ch
2774 		: ((start_elem->type == COLL_SYM) ? start_elem->opr.name[0]
2775 		   : 0));
2776     end_ch = ((end_elem->type == SB_CHAR ) ? end_elem->opr.ch
2777 	      : ((end_elem->type == COLL_SYM) ? end_elem->opr.name[0]
2778 		 : 0));
2779     if (start_ch > end_ch)
2780       return REG_ERANGE;
2781     /* Build the table for single byte characters.  */
2782     for (ch = 0; ch < SBC_MAX; ++ch)
2783       if (start_ch <= ch  && ch <= end_ch)
2784 	bitset_set (sbcset, ch);
2785   }
2786 # endif /* not RE_ENABLE_I18N */
2787   return REG_NOERROR;
2788 }
2789 #endif /* not _LIBC */
2790 
2791 #ifndef _LIBC
2792 /* Helper function for parse_bracket_exp only used in case of NOT _LIBC..
2793    Build the collating element which is represented by NAME.
2794    The result are written to MBCSET and SBCSET.
2795    COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
2796    pointer argument since we may update it.  */
2797 
2798 static reg_errcode_t
2799 internal_function
2800 # ifdef RE_ENABLE_I18N
2801 build_collating_symbol (bitset_t sbcset,
2802                         re_charset_t *mbcset _UNUSED_PARAMETER_,
2803 			Idx *coll_sym_alloc _UNUSED_PARAMETER_,
2804                         const unsigned char *name)
2805 # else /* not RE_ENABLE_I18N */
2806 build_collating_symbol (bitset_t sbcset, const unsigned char *name)
2807 # endif /* not RE_ENABLE_I18N */
2808 {
2809   size_t name_len = strlen ((const char *) name);
2810   if (BE (name_len != 1, 0))
2811     return REG_ECOLLATE;
2812   else
2813     {
2814       bitset_set (sbcset, name[0]);
2815       return REG_NOERROR;
2816     }
2817 }
2818 #endif /* not _LIBC */
2819 
2820 /* This function parse bracket expression like "[abc]", "[a-c]",
2821    "[[.a-a.]]" etc.  */
2822 
2823 static bin_tree_t *
2824 parse_bracket_exp (re_string_t *regexp, re_dfa_t *dfa, re_token_t *token,
2825 		   reg_syntax_t syntax, reg_errcode_t *err)
2826 {
2827 #ifdef _LIBC
2828   const unsigned char *collseqmb;
2829   const char *collseqwc;
2830   uint32_t nrules;
2831   int32_t table_size;
2832   const int32_t *symb_table;
2833   const unsigned char *extra;
2834 
2835   /* Local function for parse_bracket_exp used in _LIBC environment.
2836      Seek the collating symbol entry corresponding to NAME.
2837      Return the index of the symbol in the SYMB_TABLE.  */
2838 
2839   auto inline int32_t
2840   __attribute ((always_inline))
2841   seek_collating_symbol_entry (name, name_len)
2842 	 const unsigned char *name;
2843 	 size_t name_len;
2844     {
2845       int32_t hash = elem_hash ((const char *) name, name_len);
2846       int32_t elem = hash % table_size;
2847       if (symb_table[2 * elem] != 0)
2848 	{
2849 	  int32_t second = hash % (table_size - 2) + 1;
2850 
2851 	  do
2852 	    {
2853 	      /* First compare the hashing value.  */
2854 	      if (symb_table[2 * elem] == hash
2855 		  /* Compare the length of the name.  */
2856 		  && name_len == extra[symb_table[2 * elem + 1]]
2857 		  /* Compare the name.  */
2858 		  && memcmp (name, &extra[symb_table[2 * elem + 1] + 1],
2859 			     name_len) == 0)
2860 		{
2861 		  /* Yep, this is the entry.  */
2862 		  break;
2863 		}
2864 
2865 	      /* Next entry.  */
2866 	      elem += second;
2867 	    }
2868 	  while (symb_table[2 * elem] != 0);
2869 	}
2870       return elem;
2871     }
2872 
2873   /* Local function for parse_bracket_exp used in _LIBC environment.
2874      Look up the collation sequence value of BR_ELEM.
2875      Return the value if succeeded, UINT_MAX otherwise.  */
2876 
2877   auto inline unsigned int
2878   __attribute ((always_inline))
2879   lookup_collation_sequence_value (br_elem)
2880 	 bracket_elem_t *br_elem;
2881     {
2882       if (br_elem->type == SB_CHAR)
2883 	{
2884 	  /*
2885 	  if (MB_CUR_MAX == 1)
2886 	  */
2887 	  if (nrules == 0)
2888 	    return collseqmb[br_elem->opr.ch];
2889 	  else
2890 	    {
2891 	      wint_t wc = __btowc (br_elem->opr.ch);
2892 	      return __collseq_table_lookup (collseqwc, wc);
2893 	    }
2894 	}
2895       else if (br_elem->type == MB_CHAR)
2896 	{
2897 	  if (nrules != 0)
2898 	    return __collseq_table_lookup (collseqwc, br_elem->opr.wch);
2899 	}
2900       else if (br_elem->type == COLL_SYM)
2901 	{
2902 	  size_t sym_name_len = strlen ((char *) br_elem->opr.name);
2903 	  if (nrules != 0)
2904 	    {
2905 	      int32_t elem, idx;
2906 	      elem = seek_collating_symbol_entry (br_elem->opr.name,
2907 						  sym_name_len);
2908 	      if (symb_table[2 * elem] != 0)
2909 		{
2910 		  /* We found the entry.  */
2911 		  idx = symb_table[2 * elem + 1];
2912 		  /* Skip the name of collating element name.  */
2913 		  idx += 1 + extra[idx];
2914 		  /* Skip the byte sequence of the collating element.  */
2915 		  idx += 1 + extra[idx];
2916 		  /* Adjust for the alignment.  */
2917 		  idx = (idx + 3) & ~3;
2918 		  /* Skip the multibyte collation sequence value.  */
2919 		  idx += sizeof (unsigned int);
2920 		  /* Skip the wide char sequence of the collating element.  */
2921 		  idx += sizeof (unsigned int) *
2922 		    (1 + *(unsigned int *) (extra + idx));
2923 		  /* Return the collation sequence value.  */
2924 		  return *(unsigned int *) (extra + idx);
2925 		}
2926 	      else if (symb_table[2 * elem] == 0 && sym_name_len == 1)
2927 		{
2928 		  /* No valid character.  Match it as a single byte
2929 		     character.  */
2930 		  return collseqmb[br_elem->opr.name[0]];
2931 		}
2932 	    }
2933 	  else if (sym_name_len == 1)
2934 	    return collseqmb[br_elem->opr.name[0]];
2935 	}
2936       return UINT_MAX;
2937     }
2938 
2939   /* Local function for parse_bracket_exp used in _LIBC environment.
2940      Build the range expression which starts from START_ELEM, and ends
2941      at END_ELEM.  The result are written to MBCSET and SBCSET.
2942      RANGE_ALLOC is the allocated size of mbcset->range_starts, and
2943      mbcset->range_ends, is a pointer argument since we may
2944      update it.  */
2945 
2946   auto inline reg_errcode_t
2947   __attribute ((always_inline))
2948   build_range_exp (sbcset, mbcset, range_alloc, start_elem, end_elem)
2949 	 re_charset_t *mbcset;
2950 	 Idx *range_alloc;
2951 	 bitset_t sbcset;
2952 	 bracket_elem_t *start_elem, *end_elem;
2953     {
2954       unsigned int ch;
2955       uint32_t start_collseq;
2956       uint32_t end_collseq;
2957 
2958       /* Equivalence Classes and Character Classes can't be a range
2959 	 start/end.  */
2960       if (BE (start_elem->type == EQUIV_CLASS || start_elem->type == CHAR_CLASS
2961 	      || end_elem->type == EQUIV_CLASS || end_elem->type == CHAR_CLASS,
2962 	      0))
2963 	return REG_ERANGE;
2964 
2965       start_collseq = lookup_collation_sequence_value (start_elem);
2966       end_collseq = lookup_collation_sequence_value (end_elem);
2967       /* Check start/end collation sequence values.  */
2968       if (BE (start_collseq == UINT_MAX || end_collseq == UINT_MAX, 0))
2969 	return REG_ECOLLATE;
2970       if (BE ((syntax & RE_NO_EMPTY_RANGES) && start_collseq > end_collseq, 0))
2971 	return REG_ERANGE;
2972 
2973       /* Got valid collation sequence values, add them as a new entry.
2974 	 However, if we have no collation elements, and the character set
2975 	 is single byte, the single byte character set that we
2976 	 build below suffices. */
2977       if (nrules > 0 || dfa->mb_cur_max > 1)
2978 	{
2979 	  /* Check the space of the arrays.  */
2980 	  if (BE (*range_alloc == mbcset->nranges, 0))
2981 	    {
2982 	      /* There is not enough space, need realloc.  */
2983 	      uint32_t *new_array_start;
2984 	      uint32_t *new_array_end;
2985 	      Idx new_nranges;
2986 
2987 	      /* +1 in case of mbcset->nranges is 0.  */
2988 	      new_nranges = 2 * mbcset->nranges + 1;
2989 	      new_array_start = re_realloc (mbcset->range_starts, uint32_t,
2990 					    new_nranges);
2991 	      new_array_end = re_realloc (mbcset->range_ends, uint32_t,
2992 					  new_nranges);
2993 
2994 	      if (BE (new_array_start == NULL || new_array_end == NULL, 0))
2995 		return REG_ESPACE;
2996 
2997 	      mbcset->range_starts = new_array_start;
2998 	      mbcset->range_ends = new_array_end;
2999 	      *range_alloc = new_nranges;
3000 	    }
3001 
3002 	  mbcset->range_starts[mbcset->nranges] = start_collseq;
3003 	  mbcset->range_ends[mbcset->nranges++] = end_collseq;
3004 	}
3005 
3006       /* Build the table for single byte characters.  */
3007       for (ch = 0; ch < SBC_MAX; ch++)
3008 	{
3009 	  uint32_t ch_collseq;
3010 	  /*
3011 	  if (MB_CUR_MAX == 1)
3012 	  */
3013 	  if (nrules == 0)
3014 	    ch_collseq = collseqmb[ch];
3015 	  else
3016 	    ch_collseq = __collseq_table_lookup (collseqwc, __btowc (ch));
3017 	  if (start_collseq <= ch_collseq && ch_collseq <= end_collseq)
3018 	    bitset_set (sbcset, ch);
3019 	}
3020       return REG_NOERROR;
3021     }
3022 
3023   /* Local function for parse_bracket_exp used in _LIBC environment.
3024      Build the collating element which is represented by NAME.
3025      The result are written to MBCSET and SBCSET.
3026      COLL_SYM_ALLOC is the allocated size of mbcset->coll_sym, is a
3027      pointer argument since we may update it.  */
3028 
3029   auto inline reg_errcode_t
3030   __attribute ((always_inline))
3031   build_collating_symbol (sbcset, mbcset, coll_sym_alloc, name)
3032 	 re_charset_t *mbcset;
3033 	 Idx *coll_sym_alloc;
3034 	 bitset_t sbcset;
3035 	 const unsigned char *name;
3036     {
3037       int32_t elem, idx;
3038       size_t name_len = strlen ((const char *) name);
3039       if (nrules != 0)
3040 	{
3041 	  elem = seek_collating_symbol_entry (name, name_len);
3042 	  if (symb_table[2 * elem] != 0)
3043 	    {
3044 	      /* We found the entry.  */
3045 	      idx = symb_table[2 * elem + 1];
3046 	      /* Skip the name of collating element name.  */
3047 	      idx += 1 + extra[idx];
3048 	    }
3049 	  else if (symb_table[2 * elem] == 0 && name_len == 1)
3050 	    {
3051 	      /* No valid character, treat it as a normal
3052 		 character.  */
3053 	      bitset_set (sbcset, name[0]);
3054 	      return REG_NOERROR;
3055 	    }
3056 	  else
3057 	    return REG_ECOLLATE;
3058 
3059 	  /* Got valid collation sequence, add it as a new entry.  */
3060 	  /* Check the space of the arrays.  */
3061 	  if (BE (*coll_sym_alloc == mbcset->ncoll_syms, 0))
3062 	    {
3063 	      /* Not enough, realloc it.  */
3064 	      /* +1 in case of mbcset->ncoll_syms is 0.  */
3065 	      Idx new_coll_sym_alloc = 2 * mbcset->ncoll_syms + 1;
3066 	      /* Use realloc since mbcset->coll_syms is NULL
3067 		 if *alloc == 0.  */
3068 	      int32_t *new_coll_syms = re_realloc (mbcset->coll_syms, int32_t,
3069 						   new_coll_sym_alloc);
3070 	      if (BE (new_coll_syms == NULL, 0))
3071 		return REG_ESPACE;
3072 	      mbcset->coll_syms = new_coll_syms;
3073 	      *coll_sym_alloc = new_coll_sym_alloc;
3074 	    }
3075 	  mbcset->coll_syms[mbcset->ncoll_syms++] = idx;
3076 	  return REG_NOERROR;
3077 	}
3078       else
3079 	{
3080 	  if (BE (name_len != 1, 0))
3081 	    return REG_ECOLLATE;
3082 	  else
3083 	    {
3084 	      bitset_set (sbcset, name[0]);
3085 	      return REG_NOERROR;
3086 	    }
3087 	}
3088     }
3089 #endif
3090 
3091   re_token_t br_token;
3092   re_bitset_ptr_t sbcset;
3093 #ifdef RE_ENABLE_I18N
3094   re_charset_t *mbcset;
3095   Idx coll_sym_alloc = 0, range_alloc = 0, mbchar_alloc = 0;
3096   Idx equiv_class_alloc = 0, char_class_alloc = 0;
3097 #endif /* not RE_ENABLE_I18N */
3098   bool non_match = false;
3099   bin_tree_t *work_tree;
3100   int token_len;
3101   bool first_round = true;
3102 #ifdef _LIBC
3103   collseqmb = (const unsigned char *)
3104     _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQMB);
3105   nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
3106   if (nrules)
3107     {
3108       /*
3109       if (MB_CUR_MAX > 1)
3110       */
3111       collseqwc = _NL_CURRENT (LC_COLLATE, _NL_COLLATE_COLLSEQWC);
3112       table_size = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_SYMB_HASH_SIZEMB);
3113       symb_table = (const int32_t *) _NL_CURRENT (LC_COLLATE,
3114 						  _NL_COLLATE_SYMB_TABLEMB);
3115       extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
3116 						   _NL_COLLATE_SYMB_EXTRAMB);
3117     }
3118 #endif
3119   sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
3120 #ifdef RE_ENABLE_I18N
3121   mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
3122 #endif /* RE_ENABLE_I18N */
3123 #ifdef RE_ENABLE_I18N
3124   if (BE (sbcset == NULL || mbcset == NULL, 0))
3125 #else
3126   if (BE (sbcset == NULL, 0))
3127 #endif /* RE_ENABLE_I18N */
3128     {
3129       re_free (sbcset);
3130 #ifdef RE_ENABLE_I18N
3131       re_free (mbcset);
3132 #endif
3133       *err = REG_ESPACE;
3134       return NULL;
3135     }
3136 
3137   token_len = peek_token_bracket (token, regexp, syntax);
3138   if (BE (token->type == END_OF_RE, 0))
3139     {
3140       *err = REG_BADPAT;
3141       goto parse_bracket_exp_free_return;
3142     }
3143   if (token->type == OP_NON_MATCH_LIST)
3144     {
3145 #ifdef RE_ENABLE_I18N
3146       mbcset->non_match = 1;
3147 #endif /* not RE_ENABLE_I18N */
3148       non_match = true;
3149       if (syntax & RE_HAT_LISTS_NOT_NEWLINE)
3150 	bitset_set (sbcset, '\n');
3151       re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
3152       token_len = peek_token_bracket (token, regexp, syntax);
3153       if (BE (token->type == END_OF_RE, 0))
3154 	{
3155 	  *err = REG_BADPAT;
3156 	  goto parse_bracket_exp_free_return;
3157 	}
3158     }
3159 
3160   /* We treat the first ']' as a normal character.  */
3161   if (token->type == OP_CLOSE_BRACKET)
3162     token->type = CHARACTER;
3163 
3164   while (1)
3165     {
3166       bracket_elem_t start_elem, end_elem;
3167       unsigned char start_name_buf[BRACKET_NAME_BUF_SIZE];
3168       unsigned char end_name_buf[BRACKET_NAME_BUF_SIZE];
3169       reg_errcode_t ret;
3170       int token_len2 = 0;
3171       bool is_range_exp = false;
3172       re_token_t token2;
3173 
3174       start_elem.opr.name = start_name_buf;
3175       ret = parse_bracket_element (&start_elem, regexp, token, token_len, dfa,
3176 				   syntax, first_round);
3177       if (BE (ret != REG_NOERROR, 0))
3178 	{
3179 	  *err = ret;
3180 	  goto parse_bracket_exp_free_return;
3181 	}
3182       first_round = false;
3183 
3184       /* Get information about the next token.  We need it in any case.  */
3185       token_len = peek_token_bracket (token, regexp, syntax);
3186 
3187       /* Do not check for ranges if we know they are not allowed.  */
3188       if (start_elem.type != CHAR_CLASS && start_elem.type != EQUIV_CLASS)
3189 	{
3190 	  if (BE (token->type == END_OF_RE, 0))
3191 	    {
3192 	      *err = REG_EBRACK;
3193 	      goto parse_bracket_exp_free_return;
3194 	    }
3195 	  if (token->type == OP_CHARSET_RANGE)
3196 	    {
3197 	      re_string_skip_bytes (regexp, token_len); /* Skip '-'.  */
3198 	      token_len2 = peek_token_bracket (&token2, regexp, syntax);
3199 	      if (BE (token2.type == END_OF_RE, 0))
3200 		{
3201 		  *err = REG_EBRACK;
3202 		  goto parse_bracket_exp_free_return;
3203 		}
3204 	      if (token2.type == OP_CLOSE_BRACKET)
3205 		{
3206 		  /* We treat the last '-' as a normal character.  */
3207 		  re_string_skip_bytes (regexp, -token_len);
3208 		  token->type = CHARACTER;
3209 		}
3210 	      else
3211 		is_range_exp = true;
3212 	    }
3213 	}
3214 
3215       if (is_range_exp == true)
3216 	{
3217 	  end_elem.opr.name = end_name_buf;
3218 	  ret = parse_bracket_element (&end_elem, regexp, &token2, token_len2,
3219 				       dfa, syntax, true);
3220 	  if (BE (ret != REG_NOERROR, 0))
3221 	    {
3222 	      *err = ret;
3223 	      goto parse_bracket_exp_free_return;
3224 	    }
3225 
3226 	  token_len = peek_token_bracket (token, regexp, syntax);
3227 
3228 #ifdef _LIBC
3229 	  *err = build_range_exp (sbcset, mbcset, &range_alloc,
3230 				  &start_elem, &end_elem);
3231 #else
3232 # ifdef RE_ENABLE_I18N
3233 	  *err = build_range_exp (syntax, sbcset,
3234 				  dfa->mb_cur_max > 1 ? mbcset : NULL,
3235 				  &range_alloc, &start_elem, &end_elem);
3236 # else
3237 	  *err = build_range_exp (syntax, sbcset, &start_elem, &end_elem);
3238 # endif
3239 #endif /* RE_ENABLE_I18N */
3240 	  if (BE (*err != REG_NOERROR, 0))
3241 	    goto parse_bracket_exp_free_return;
3242 	}
3243       else
3244 	{
3245 	  switch (start_elem.type)
3246 	    {
3247 	    case SB_CHAR:
3248 	      bitset_set (sbcset, start_elem.opr.ch);
3249 	      break;
3250 #ifdef RE_ENABLE_I18N
3251 	    case MB_CHAR:
3252 	      /* Check whether the array has enough space.  */
3253 	      if (BE (mbchar_alloc == mbcset->nmbchars, 0))
3254 		{
3255 		  wchar_t *new_mbchars;
3256 		  /* Not enough, realloc it.  */
3257 		  /* +1 in case of mbcset->nmbchars is 0.  */
3258 		  mbchar_alloc = 2 * mbcset->nmbchars + 1;
3259 		  /* Use realloc since array is NULL if *alloc == 0.  */
3260 		  new_mbchars = re_realloc (mbcset->mbchars, wchar_t,
3261 					    mbchar_alloc);
3262 		  if (BE (new_mbchars == NULL, 0))
3263 		    goto parse_bracket_exp_espace;
3264 		  mbcset->mbchars = new_mbchars;
3265 		}
3266 	      mbcset->mbchars[mbcset->nmbchars++] = start_elem.opr.wch;
3267 	      break;
3268 #endif /* RE_ENABLE_I18N */
3269 	    case EQUIV_CLASS:
3270 	      *err = build_equiv_class (sbcset,
3271 #ifdef RE_ENABLE_I18N
3272 					mbcset, &equiv_class_alloc,
3273 #endif /* RE_ENABLE_I18N */
3274 					start_elem.opr.name);
3275 	      if (BE (*err != REG_NOERROR, 0))
3276 		goto parse_bracket_exp_free_return;
3277 	      break;
3278 	    case COLL_SYM:
3279 	      *err = build_collating_symbol (sbcset,
3280 #ifdef RE_ENABLE_I18N
3281 					     mbcset, &coll_sym_alloc,
3282 #endif /* RE_ENABLE_I18N */
3283 					     start_elem.opr.name);
3284 	      if (BE (*err != REG_NOERROR, 0))
3285 		goto parse_bracket_exp_free_return;
3286 	      break;
3287 	    case CHAR_CLASS:
3288 	      *err = build_charclass (regexp->trans, sbcset,
3289 #ifdef RE_ENABLE_I18N
3290 				      mbcset, &char_class_alloc,
3291 #endif /* RE_ENABLE_I18N */
3292 				      start_elem.opr.name, syntax);
3293 	      if (BE (*err != REG_NOERROR, 0))
3294 	       goto parse_bracket_exp_free_return;
3295 	      break;
3296 	    default:
3297 	      assert (0);
3298 	      break;
3299 	    }
3300 	}
3301       if (BE (token->type == END_OF_RE, 0))
3302 	{
3303 	  *err = REG_EBRACK;
3304 	  goto parse_bracket_exp_free_return;
3305 	}
3306       if (token->type == OP_CLOSE_BRACKET)
3307 	break;
3308     }
3309 
3310   re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
3311 
3312   /* If it is non-matching list.  */
3313   if (non_match)
3314     bitset_not (sbcset);
3315 
3316 #ifdef RE_ENABLE_I18N
3317   /* Ensure only single byte characters are set.  */
3318   if (dfa->mb_cur_max > 1)
3319     bitset_mask (sbcset, dfa->sb_char);
3320 
3321   if (mbcset->nmbchars || mbcset->ncoll_syms || mbcset->nequiv_classes
3322       || mbcset->nranges || (dfa->mb_cur_max > 1 && (mbcset->nchar_classes
3323 						     || mbcset->non_match)))
3324     {
3325       bin_tree_t *mbc_tree;
3326       int sbc_idx;
3327       /* Build a tree for complex bracket.  */
3328       dfa->has_mb_node = 1;
3329       br_token.type = COMPLEX_BRACKET;
3330       br_token.opr.mbcset = mbcset;
3331       mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
3332       if (BE (mbc_tree == NULL, 0))
3333 	goto parse_bracket_exp_espace;
3334       for (sbc_idx = 0; sbc_idx < BITSET_WORDS; ++sbc_idx)
3335 	if (sbcset[sbc_idx])
3336 	  break;
3337       /* If there are no bits set in sbcset, there is no point
3338 	 of having both SIMPLE_BRACKET and COMPLEX_BRACKET.  */
3339       if (sbc_idx < BITSET_WORDS)
3340 	{
3341 	  /* Build a tree for simple bracket.  */
3342 	  br_token.type = SIMPLE_BRACKET;
3343 	  br_token.opr.sbcset = sbcset;
3344 	  work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
3345 	  if (BE (work_tree == NULL, 0))
3346 	    goto parse_bracket_exp_espace;
3347 
3348 	  /* Then join them by ALT node.  */
3349 	  work_tree = create_tree (dfa, work_tree, mbc_tree, OP_ALT);
3350 	  if (BE (work_tree == NULL, 0))
3351 	    goto parse_bracket_exp_espace;
3352 	}
3353       else
3354 	{
3355 	  re_free (sbcset);
3356 	  work_tree = mbc_tree;
3357 	}
3358     }
3359   else
3360 #endif /* not RE_ENABLE_I18N */
3361     {
3362 #ifdef RE_ENABLE_I18N
3363       free_charset (mbcset);
3364 #endif
3365       /* Build a tree for simple bracket.  */
3366       br_token.type = SIMPLE_BRACKET;
3367       br_token.opr.sbcset = sbcset;
3368       work_tree = create_token_tree (dfa, NULL, NULL, &br_token);
3369       if (BE (work_tree == NULL, 0))
3370 	goto parse_bracket_exp_espace;
3371     }
3372   return work_tree;
3373 
3374  parse_bracket_exp_espace:
3375   *err = REG_ESPACE;
3376  parse_bracket_exp_free_return:
3377   re_free (sbcset);
3378 #ifdef RE_ENABLE_I18N
3379   free_charset (mbcset);
3380 #endif /* RE_ENABLE_I18N */
3381   return NULL;
3382 }
3383 
3384 /* Parse an element in the bracket expression.  */
3385 
3386 static reg_errcode_t
3387 parse_bracket_element (bracket_elem_t *elem, re_string_t *regexp,
3388 		       re_token_t *token, int token_len,
3389 		       re_dfa_t *dfa _UNUSED_PARAMETER_,
3390 		       reg_syntax_t syntax, bool accept_hyphen)
3391 {
3392 #ifdef RE_ENABLE_I18N
3393   int cur_char_size;
3394   cur_char_size = re_string_char_size_at (regexp, re_string_cur_idx (regexp));
3395   if (cur_char_size > 1)
3396     {
3397       elem->type = MB_CHAR;
3398       elem->opr.wch = re_string_wchar_at (regexp, re_string_cur_idx (regexp));
3399       re_string_skip_bytes (regexp, cur_char_size);
3400       return REG_NOERROR;
3401     }
3402 #endif /* RE_ENABLE_I18N */
3403   re_string_skip_bytes (regexp, token_len); /* Skip a token.  */
3404   if (token->type == OP_OPEN_COLL_ELEM || token->type == OP_OPEN_CHAR_CLASS
3405       || token->type == OP_OPEN_EQUIV_CLASS)
3406     return parse_bracket_symbol (elem, regexp, token);
3407   if (BE (token->type == OP_CHARSET_RANGE, 0) && !accept_hyphen)
3408     {
3409       /* A '-' must only appear as anything but a range indicator before
3410 	 the closing bracket.  Everything else is an error.  */
3411       re_token_t token2;
3412       (void) peek_token_bracket (&token2, regexp, syntax);
3413       if (token2.type != OP_CLOSE_BRACKET)
3414 	/* The actual error value is not standardized since this whole
3415 	   case is undefined.  But ERANGE makes good sense.  */
3416 	return REG_ERANGE;
3417     }
3418   elem->type = SB_CHAR;
3419   elem->opr.ch = token->opr.c;
3420   return REG_NOERROR;
3421 }
3422 
3423 /* Parse a bracket symbol in the bracket expression.  Bracket symbols are
3424    such as [:<character_class>:], [.<collating_element>.], and
3425    [=<equivalent_class>=].  */
3426 
3427 static reg_errcode_t
3428 parse_bracket_symbol (bracket_elem_t *elem, re_string_t *regexp,
3429 		      re_token_t *token)
3430 {
3431   unsigned char ch, delim = token->opr.c;
3432   int i = 0;
3433   if (re_string_eoi(regexp))
3434     return REG_EBRACK;
3435   for (;; ++i)
3436     {
3437       if (i >= BRACKET_NAME_BUF_SIZE)
3438 	return REG_EBRACK;
3439       if (token->type == OP_OPEN_CHAR_CLASS)
3440 	ch = re_string_fetch_byte_case (regexp);
3441       else
3442 	ch = re_string_fetch_byte (regexp);
3443       if (re_string_eoi(regexp))
3444 	return REG_EBRACK;
3445       if (ch == delim && re_string_peek_byte (regexp, 0) == ']')
3446 	break;
3447       elem->opr.name[i] = ch;
3448     }
3449   re_string_skip_bytes (regexp, 1);
3450   elem->opr.name[i] = '\0';
3451   switch (token->type)
3452     {
3453     case OP_OPEN_COLL_ELEM:
3454       elem->type = COLL_SYM;
3455       break;
3456     case OP_OPEN_EQUIV_CLASS:
3457       elem->type = EQUIV_CLASS;
3458       break;
3459     case OP_OPEN_CHAR_CLASS:
3460       elem->type = CHAR_CLASS;
3461       break;
3462     default:
3463       break;
3464     }
3465   return REG_NOERROR;
3466 }
3467 
3468   /* Helper function for parse_bracket_exp.
3469      Build the equivalence class which is represented by NAME.
3470      The result are written to MBCSET and SBCSET.
3471      EQUIV_CLASS_ALLOC is the allocated size of mbcset->equiv_classes,
3472      is a pointer argument since we may update it.  */
3473 
3474 static reg_errcode_t
3475 #ifdef RE_ENABLE_I18N
3476 build_equiv_class (bitset_t sbcset,
3477                    re_charset_t *mbcset _UNUSED_PARAMETER_,
3478 		   Idx *equiv_class_alloc _UNUSED_PARAMETER_,
3479 		   const unsigned char *name)
3480 #else /* not RE_ENABLE_I18N */
3481 build_equiv_class (bitset_t sbcset, const unsigned char *name)
3482 #endif /* not RE_ENABLE_I18N */
3483 {
3484 #ifdef _LIBC
3485   uint32_t nrules = _NL_CURRENT_WORD (LC_COLLATE, _NL_COLLATE_NRULES);
3486   if (nrules != 0)
3487     {
3488       const int32_t *table, *indirect;
3489       const unsigned char *weights, *extra, *cp;
3490       unsigned char char_buf[2];
3491       int32_t idx1, idx2;
3492       unsigned int ch;
3493       size_t len;
3494       /* This #include defines a local function!  */
3495 # include <locale/weight.h>
3496       /* Calculate the index for equivalence class.  */
3497       cp = name;
3498       table = (const int32_t *) _NL_CURRENT (LC_COLLATE, _NL_COLLATE_TABLEMB);
3499       weights = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
3500 					       _NL_COLLATE_WEIGHTMB);
3501       extra = (const unsigned char *) _NL_CURRENT (LC_COLLATE,
3502 						   _NL_COLLATE_EXTRAMB);
3503       indirect = (const int32_t *) _NL_CURRENT (LC_COLLATE,
3504 						_NL_COLLATE_INDIRECTMB);
3505       idx1 = findidx (&cp, -1);
3506       if (BE (idx1 == 0 || *cp != '\0', 0))
3507 	/* This isn't a valid character.  */
3508 	return REG_ECOLLATE;
3509 
3510       /* Build single byte matching table for this equivalence class.  */
3511       len = weights[idx1 & 0xffffff];
3512       for (ch = 0; ch < SBC_MAX; ++ch)
3513 	{
3514 	  char_buf[0] = ch;
3515 	  cp = char_buf;
3516 	  idx2 = findidx (&cp, 1);
3517 /*
3518 	  idx2 = table[ch];
3519 */
3520 	  if (idx2 == 0)
3521 	    /* This isn't a valid character.  */
3522 	    continue;
3523 	  /* Compare only if the length matches and the collation rule
3524 	     index is the same.  */
3525 	  if (len == weights[idx2 & 0xffffff] && (idx1 >> 24) == (idx2 >> 24))
3526 	    {
3527 	      int cnt = 0;
3528 
3529 	      while (cnt <= len &&
3530 		     weights[(idx1 & 0xffffff) + 1 + cnt]
3531 		     == weights[(idx2 & 0xffffff) + 1 + cnt])
3532 		++cnt;
3533 
3534 	      if (cnt > len)
3535 		bitset_set (sbcset, ch);
3536 	    }
3537 	}
3538       /* Check whether the array has enough space.  */
3539       if (BE (*equiv_class_alloc == mbcset->nequiv_classes, 0))
3540 	{
3541 	  /* Not enough, realloc it.  */
3542 	  /* +1 in case of mbcset->nequiv_classes is 0.  */
3543 	  Idx new_equiv_class_alloc = 2 * mbcset->nequiv_classes + 1;
3544 	  /* Use realloc since the array is NULL if *alloc == 0.  */
3545 	  int32_t *new_equiv_classes = re_realloc (mbcset->equiv_classes,
3546 						   int32_t,
3547 						   new_equiv_class_alloc);
3548 	  if (BE (new_equiv_classes == NULL, 0))
3549 	    return REG_ESPACE;
3550 	  mbcset->equiv_classes = new_equiv_classes;
3551 	  *equiv_class_alloc = new_equiv_class_alloc;
3552 	}
3553       mbcset->equiv_classes[mbcset->nequiv_classes++] = idx1;
3554     }
3555   else
3556 #endif /* _LIBC */
3557     {
3558       if (BE (strlen ((const char *) name) != 1, 0))
3559 	return REG_ECOLLATE;
3560       bitset_set (sbcset, *name);
3561     }
3562   return REG_NOERROR;
3563 }
3564 
3565   /* Helper function for parse_bracket_exp.
3566      Build the character class which is represented by NAME.
3567      The result are written to MBCSET and SBCSET.
3568      CHAR_CLASS_ALLOC is the allocated size of mbcset->char_classes,
3569      is a pointer argument since we may update it.  */
3570 
3571 static reg_errcode_t
3572 #ifdef RE_ENABLE_I18N
3573 build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
3574 		 re_charset_t *mbcset, Idx *char_class_alloc,
3575 		 const unsigned char *class_name, reg_syntax_t syntax)
3576 #else /* not RE_ENABLE_I18N */
3577 build_charclass (RE_TRANSLATE_TYPE trans, bitset_t sbcset,
3578 		 const unsigned char *class_name, reg_syntax_t syntax)
3579 #endif /* not RE_ENABLE_I18N */
3580 {
3581   int i;
3582   const char *name = (const char *) class_name;
3583 
3584   /* In case of REG_ICASE "upper" and "lower" match the both of
3585      upper and lower cases.  */
3586   if ((syntax & RE_ICASE)
3587       && (strcmp (name, "upper") == 0 || strcmp (name, "lower") == 0))
3588     name = "alpha";
3589 
3590 #ifdef RE_ENABLE_I18N
3591   /* Check the space of the arrays.  */
3592   if (BE (*char_class_alloc == mbcset->nchar_classes, 0))
3593     {
3594       /* Not enough, realloc it.  */
3595       /* +1 in case of mbcset->nchar_classes is 0.  */
3596       Idx new_char_class_alloc = 2 * mbcset->nchar_classes + 1;
3597       /* Use realloc since array is NULL if *alloc == 0.  */
3598       wctype_t *new_char_classes = re_realloc (mbcset->char_classes, wctype_t,
3599 					       new_char_class_alloc);
3600       if (BE (new_char_classes == NULL, 0))
3601 	return REG_ESPACE;
3602       mbcset->char_classes = new_char_classes;
3603       *char_class_alloc = new_char_class_alloc;
3604     }
3605   mbcset->char_classes[mbcset->nchar_classes++] = __wctype (name);
3606 #endif /* RE_ENABLE_I18N */
3607 
3608 #define BUILD_CHARCLASS_LOOP(ctype_func)	\
3609   do {						\
3610     if (BE (trans != NULL, 0))			\
3611       {						\
3612 	for (i = 0; i < SBC_MAX; ++i)		\
3613 	  if (ctype_func (i))			\
3614 	    bitset_set (sbcset, trans[i]);	\
3615       }						\
3616     else					\
3617       {						\
3618 	for (i = 0; i < SBC_MAX; ++i)		\
3619 	  if (ctype_func (i))			\
3620 	    bitset_set (sbcset, i);		\
3621       }						\
3622   } while (0)
3623 
3624   if (strcmp (name, "alnum") == 0)
3625     BUILD_CHARCLASS_LOOP (isalnum);
3626   else if (strcmp (name, "cntrl") == 0)
3627     BUILD_CHARCLASS_LOOP (iscntrl);
3628   else if (strcmp (name, "lower") == 0)
3629     BUILD_CHARCLASS_LOOP (islower);
3630   else if (strcmp (name, "space") == 0)
3631     BUILD_CHARCLASS_LOOP (isspace);
3632   else if (strcmp (name, "alpha") == 0)
3633     BUILD_CHARCLASS_LOOP (isalpha);
3634   else if (strcmp (name, "digit") == 0)
3635     BUILD_CHARCLASS_LOOP (isdigit);
3636   else if (strcmp (name, "print") == 0)
3637     BUILD_CHARCLASS_LOOP (isprint);
3638   else if (strcmp (name, "upper") == 0)
3639     BUILD_CHARCLASS_LOOP (isupper);
3640   else if (strcmp (name, "blank") == 0)
3641     BUILD_CHARCLASS_LOOP (isblank);
3642   else if (strcmp (name, "graph") == 0)
3643     BUILD_CHARCLASS_LOOP (isgraph);
3644   else if (strcmp (name, "punct") == 0)
3645     BUILD_CHARCLASS_LOOP (ispunct);
3646   else if (strcmp (name, "xdigit") == 0)
3647     BUILD_CHARCLASS_LOOP (isxdigit);
3648   else
3649     return REG_ECTYPE;
3650 
3651   return REG_NOERROR;
3652 }
3653 
3654 static bin_tree_t *
3655 build_charclass_op (re_dfa_t *dfa, RE_TRANSLATE_TYPE trans,
3656 		    const unsigned char *class_name,
3657 		    const unsigned char *extra, bool non_match,
3658 		    reg_errcode_t *err)
3659 {
3660   re_bitset_ptr_t sbcset;
3661 #ifdef RE_ENABLE_I18N
3662   re_charset_t *mbcset;
3663   Idx alloc = 0;
3664 #endif /* not RE_ENABLE_I18N */
3665   reg_errcode_t ret;
3666   re_token_t br_token;
3667   bin_tree_t *tree;
3668 
3669   sbcset = (re_bitset_ptr_t) calloc (sizeof (bitset_t), 1);
3670 #ifdef RE_ENABLE_I18N
3671   mbcset = (re_charset_t *) calloc (sizeof (re_charset_t), 1);
3672 #endif /* RE_ENABLE_I18N */
3673 
3674 #ifdef RE_ENABLE_I18N
3675   if (BE (sbcset == NULL || mbcset == NULL, 0))
3676 #else /* not RE_ENABLE_I18N */
3677   if (BE (sbcset == NULL, 0))
3678 #endif /* not RE_ENABLE_I18N */
3679     {
3680       *err = REG_ESPACE;
3681       return NULL;
3682     }
3683 
3684   if (non_match)
3685     {
3686 #ifdef RE_ENABLE_I18N
3687       mbcset->non_match = 1;
3688 #endif /* not RE_ENABLE_I18N */
3689     }
3690 
3691   /* We don't care the syntax in this case.  */
3692   ret = build_charclass (trans, sbcset,
3693 #ifdef RE_ENABLE_I18N
3694 			 mbcset, &alloc,
3695 #endif /* RE_ENABLE_I18N */
3696 			 class_name, 0);
3697 
3698   if (BE (ret != REG_NOERROR, 0))
3699     {
3700       re_free (sbcset);
3701 #ifdef RE_ENABLE_I18N
3702       free_charset (mbcset);
3703 #endif /* RE_ENABLE_I18N */
3704       *err = ret;
3705       return NULL;
3706     }
3707   /* \w match '_' also.  */
3708   for (; *extra; extra++)
3709     bitset_set (sbcset, *extra);
3710 
3711   /* If it is non-matching list.  */
3712   if (non_match)
3713     bitset_not (sbcset);
3714 
3715 #ifdef RE_ENABLE_I18N
3716   /* Ensure only single byte characters are set.  */
3717   if (dfa->mb_cur_max > 1)
3718     bitset_mask (sbcset, dfa->sb_char);
3719 #endif
3720 
3721   /* Build a tree for simple bracket.  */
3722   br_token.type = SIMPLE_BRACKET;
3723   br_token.opr.sbcset = sbcset;
3724   tree = create_token_tree (dfa, NULL, NULL, &br_token);
3725   if (BE (tree == NULL, 0))
3726     goto build_word_op_espace;
3727 
3728 #ifdef RE_ENABLE_I18N
3729   if (dfa->mb_cur_max > 1)
3730     {
3731       bin_tree_t *mbc_tree;
3732       /* Build a tree for complex bracket.  */
3733       br_token.type = COMPLEX_BRACKET;
3734       br_token.opr.mbcset = mbcset;
3735       dfa->has_mb_node = 1;
3736       mbc_tree = create_token_tree (dfa, NULL, NULL, &br_token);
3737       if (BE (mbc_tree == NULL, 0))
3738 	goto build_word_op_espace;
3739       /* Then join them by ALT node.  */
3740       tree = create_tree (dfa, tree, mbc_tree, OP_ALT);
3741       if (BE (mbc_tree != NULL, 1))
3742 	return tree;
3743     }
3744   else
3745     {
3746       free_charset (mbcset);
3747       return tree;
3748     }
3749 #else /* not RE_ENABLE_I18N */
3750   return tree;
3751 #endif /* not RE_ENABLE_I18N */
3752 
3753  build_word_op_espace:
3754   re_free (sbcset);
3755 #ifdef RE_ENABLE_I18N
3756   free_charset (mbcset);
3757 #endif /* RE_ENABLE_I18N */
3758   *err = REG_ESPACE;
3759   return NULL;
3760 }
3761 
3762 /* This is intended for the expressions like "a{1,3}".
3763    Fetch a number from 'input', and return the number.
3764    Return REG_MISSING if the number field is empty like "{,1}".
3765    Return RE_DUP_MAX + 1 if the number field is too large.
3766    Return REG_ERROR if an error occurred.  */
3767 
3768 static Idx
3769 fetch_number (re_string_t *input, re_token_t *token, reg_syntax_t syntax)
3770 {
3771   Idx num = REG_MISSING;
3772   unsigned char c;
3773   while (1)
3774     {
3775       fetch_token (token, input, syntax);
3776       c = token->opr.c;
3777       if (BE (token->type == END_OF_RE, 0))
3778 	return REG_ERROR;
3779       if (token->type == OP_CLOSE_DUP_NUM || c == ',')
3780 	break;
3781       num = ((token->type != CHARACTER || c < '0' || '9' < c
3782 	      || num == REG_ERROR)
3783 	     ? REG_ERROR
3784 	     : num == REG_MISSING
3785 	     ? c - '0'
3786 	     : MIN (RE_DUP_MAX + 1, num * 10 + c - '0'));
3787     }
3788   return num;
3789 }
3790 
3791 #ifdef RE_ENABLE_I18N
3792 static void
3793 free_charset (re_charset_t *cset)
3794 {
3795   re_free (cset->mbchars);
3796 # ifdef _LIBC
3797   re_free (cset->coll_syms);
3798   re_free (cset->equiv_classes);
3799   re_free (cset->range_starts);
3800   re_free (cset->range_ends);
3801 # endif
3802   re_free (cset->char_classes);
3803   re_free (cset);
3804 }
3805 #endif /* RE_ENABLE_I18N */
3806 
3807 /* Functions for binary tree operation.  */
3808 
3809 /* Create a tree node.  */
3810 
3811 static bin_tree_t *
3812 create_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
3813 	     re_token_type_t type)
3814 {
3815   re_token_t t;
3816   t.type = type;
3817   return create_token_tree (dfa, left, right, &t);
3818 }
3819 
3820 static bin_tree_t *
3821 create_token_tree (re_dfa_t *dfa, bin_tree_t *left, bin_tree_t *right,
3822 		   const re_token_t *token)
3823 {
3824   bin_tree_t *tree;
3825   if (BE (dfa->str_tree_storage_idx == BIN_TREE_STORAGE_SIZE, 0))
3826     {
3827       bin_tree_storage_t *storage = re_malloc (bin_tree_storage_t, 1);
3828 
3829       if (storage == NULL)
3830 	return NULL;
3831       storage->next = dfa->str_tree_storage;
3832       dfa->str_tree_storage = storage;
3833       dfa->str_tree_storage_idx = 0;
3834     }
3835   tree = &dfa->str_tree_storage->data[dfa->str_tree_storage_idx++];
3836 
3837   tree->parent = NULL;
3838   tree->left = left;
3839   tree->right = right;
3840   tree->token = *token;
3841   tree->token.duplicated = 0;
3842   tree->token.opt_subexp = 0;
3843   tree->first = NULL;
3844   tree->next = NULL;
3845   tree->node_idx = REG_MISSING;
3846 
3847   if (left != NULL)
3848     left->parent = tree;
3849   if (right != NULL)
3850     right->parent = tree;
3851   return tree;
3852 }
3853 
3854 /* Mark the tree SRC as an optional subexpression.
3855    To be called from preorder or postorder.  */
3856 
3857 static reg_errcode_t
3858 mark_opt_subexp (void *extra, bin_tree_t *node)
3859 {
3860   Idx idx = (Idx) (long) extra;
3861   if (node->token.type == SUBEXP && node->token.opr.idx == idx)
3862     node->token.opt_subexp = 1;
3863 
3864   return REG_NOERROR;
3865 }
3866 
3867 /* Free the allocated memory inside NODE. */
3868 
3869 static void
3870 free_token (re_token_t *node)
3871 {
3872 #ifdef RE_ENABLE_I18N
3873   if (node->type == COMPLEX_BRACKET && node->duplicated == 0)
3874     free_charset (node->opr.mbcset);
3875   else
3876 #endif /* RE_ENABLE_I18N */
3877     if (node->type == SIMPLE_BRACKET && node->duplicated == 0)
3878       re_free (node->opr.sbcset);
3879 }
3880 
3881 /* Worker function for tree walking.  Free the allocated memory inside NODE
3882    and its children. */
3883 
3884 static reg_errcode_t
3885 free_tree (void *extra _UNUSED_PARAMETER_, bin_tree_t *node)
3886 {
3887   free_token (&node->token);
3888   return REG_NOERROR;
3889 }
3890 
3891 
3892 /* Duplicate the node SRC, and return new node.  This is a preorder
3893    visit similar to the one implemented by the generic visitor, but
3894    we need more infrastructure to maintain two parallel trees --- so,
3895    it's easier to duplicate.  */
3896 
3897 static bin_tree_t *
3898 duplicate_tree (const bin_tree_t *root, re_dfa_t *dfa)
3899 {
3900   const bin_tree_t *node;
3901   bin_tree_t *dup_root;
3902   bin_tree_t **p_new = &dup_root, *dup_node = root->parent;
3903 
3904   for (node = root; ; )
3905     {
3906       /* Create a new tree and link it back to the current parent.  */
3907       *p_new = create_token_tree (dfa, NULL, NULL, &node->token);
3908       if (*p_new == NULL)
3909 	return NULL;
3910       (*p_new)->parent = dup_node;
3911       (*p_new)->token.duplicated = 1;
3912       dup_node = *p_new;
3913 
3914       /* Go to the left node, or up and to the right.  */
3915       if (node->left)
3916 	{
3917 	  node = node->left;
3918 	  p_new = &dup_node->left;
3919 	}
3920       else
3921 	{
3922 	  const bin_tree_t *prev = NULL;
3923 	  while (node->right == prev || node->right == NULL)
3924 	    {
3925 	      prev = node;
3926 	      node = node->parent;
3927 	      dup_node = dup_node->parent;
3928 	      if (!node)
3929 		return dup_root;
3930 	    }
3931 	  node = node->right;
3932 	  p_new = &dup_node->right;
3933 	}
3934     }
3935 }
3936