PostgreSQL Source Code  git master
regcomp.c
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1 /*
2  * re_*comp and friends - compile REs
3  * This file #includes several others (see the bottom).
4  *
5  * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
6  *
7  * Development of this software was funded, in part, by Cray Research Inc.,
8  * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
9  * Corporation, none of whom are responsible for the results. The author
10  * thanks all of them.
11  *
12  * Redistribution and use in source and binary forms -- with or without
13  * modification -- are permitted for any purpose, provided that
14  * redistributions in source form retain this entire copyright notice and
15  * indicate the origin and nature of any modifications.
16  *
17  * I'd appreciate being given credit for this package in the documentation
18  * of software which uses it, but that is not a requirement.
19  *
20  * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
21  * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
22  * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
23  * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
24  * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
25  * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
26  * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
27  * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
28  * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
29  * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
30  *
31  * src/backend/regex/regcomp.c
32  *
33  */
34 
35 #include "regex/regguts.h"
36 
37 /*
38  * forward declarations, up here so forward datatypes etc. are defined early
39  */
40 /* === regcomp.c === */
41 static void moresubs(struct vars *, int);
42 static int freev(struct vars *, int);
43 static void makesearch(struct vars *, struct nfa *);
44 static struct subre *parse(struct vars *, int, int, struct state *, struct state *);
45 static struct subre *parsebranch(struct vars *, int, int, struct state *, struct state *, int);
46 static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *);
47 static void nonword(struct vars *, int, struct state *, struct state *);
48 static void word(struct vars *, int, struct state *, struct state *);
49 static int scannum(struct vars *);
50 static void repeat(struct vars *, struct state *, struct state *, int, int);
51 static void bracket(struct vars *, struct state *, struct state *);
52 static void cbracket(struct vars *, struct state *, struct state *);
53 static void brackpart(struct vars *, struct state *, struct state *);
54 static const chr *scanplain(struct vars *);
55 static void onechr(struct vars *, chr, struct state *, struct state *);
56 static void wordchrs(struct vars *);
57 static void processlacon(struct vars *, struct state *, struct state *, int,
58  struct state *, struct state *);
59 static struct subre *subre(struct vars *, int, int, struct state *, struct state *);
60 static void freesubre(struct vars *, struct subre *);
61 static void freesrnode(struct vars *, struct subre *);
62 static void optst(struct vars *, struct subre *);
63 static int numst(struct subre *, int);
64 static void markst(struct subre *);
65 static void cleanst(struct vars *);
66 static long nfatree(struct vars *, struct subre *, FILE *);
67 static long nfanode(struct vars *, struct subre *, int, FILE *);
68 static int newlacon(struct vars *, struct state *, struct state *, int);
69 static void freelacons(struct subre *, int);
70 static void rfree(regex_t *);
71 static int rcancelrequested(void);
72 static int rstacktoodeep(void);
73 
74 #ifdef REG_DEBUG
75 static void dump(regex_t *, FILE *);
76 static void dumpst(struct subre *, FILE *, int);
77 static void stdump(struct subre *, FILE *, int);
78 static const char *stid(struct subre *, char *, size_t);
79 #endif
80 /* === regc_lex.c === */
81 static void lexstart(struct vars *);
82 static void prefixes(struct vars *);
83 static void lexnest(struct vars *, const chr *, const chr *);
84 static void lexword(struct vars *);
85 static int next(struct vars *);
86 static int lexescape(struct vars *);
87 static chr lexdigits(struct vars *, int, int, int);
88 static int brenext(struct vars *, chr);
89 static void skip(struct vars *);
90 static chr newline(void);
91 static chr chrnamed(struct vars *, const chr *, const chr *, chr);
92 
93 /* === regc_color.c === */
94 static void initcm(struct vars *, struct colormap *);
95 static void freecm(struct colormap *);
96 static color maxcolor(struct colormap *);
97 static color newcolor(struct colormap *);
98 static void freecolor(struct colormap *, color);
99 static color pseudocolor(struct colormap *);
100 static color subcolor(struct colormap *, chr);
101 static color subcolorhi(struct colormap *, color *);
102 static color newsub(struct colormap *, color);
103 static int newhicolorrow(struct colormap *, int);
104 static void newhicolorcols(struct colormap *);
105 static void subcolorcvec(struct vars *, struct cvec *, struct state *, struct state *);
106 static void subcoloronechr(struct vars *, chr, struct state *, struct state *, color *);
107 static void subcoloronerange(struct vars *, chr, chr, struct state *, struct state *, color *);
108 static void subcoloronerow(struct vars *, int, struct state *, struct state *, color *);
109 static void okcolors(struct nfa *, struct colormap *);
110 static void colorchain(struct colormap *, struct arc *);
111 static void uncolorchain(struct colormap *, struct arc *);
112 static void rainbow(struct nfa *, struct colormap *, int, color, struct state *, struct state *);
113 static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *);
114 
115 #ifdef REG_DEBUG
116 static void dumpcolors(struct colormap *, FILE *);
117 static void dumpchr(chr, FILE *);
118 #endif
119 /* === regc_nfa.c === */
120 static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *);
121 static void freenfa(struct nfa *);
122 static struct state *newstate(struct nfa *);
123 static struct state *newfstate(struct nfa *, int flag);
124 static void dropstate(struct nfa *, struct state *);
125 static void freestate(struct nfa *, struct state *);
126 static void destroystate(struct nfa *, struct state *);
127 static void newarc(struct nfa *, int, color, struct state *, struct state *);
128 static void createarc(struct nfa *, int, color, struct state *, struct state *);
129 static struct arc *allocarc(struct nfa *, struct state *);
130 static void freearc(struct nfa *, struct arc *);
131 static void changearctarget(struct arc *, struct state *);
132 static int hasnonemptyout(struct state *);
133 static struct arc *findarc(struct state *, int, color);
134 static void cparc(struct nfa *, struct arc *, struct state *, struct state *);
135 static void sortins(struct nfa *, struct state *);
136 static int sortins_cmp(const void *, const void *);
137 static void sortouts(struct nfa *, struct state *);
138 static int sortouts_cmp(const void *, const void *);
139 static void moveins(struct nfa *, struct state *, struct state *);
140 static void copyins(struct nfa *, struct state *, struct state *);
141 static void mergeins(struct nfa *, struct state *, struct arc **, int);
142 static void moveouts(struct nfa *, struct state *, struct state *);
143 static void copyouts(struct nfa *, struct state *, struct state *);
144 static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
145 static void delsub(struct nfa *, struct state *, struct state *);
146 static void deltraverse(struct nfa *, struct state *, struct state *);
147 static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *);
148 static void duptraverse(struct nfa *, struct state *, struct state *);
149 static void cleartraverse(struct nfa *, struct state *);
150 static struct state *single_color_transition(struct state *, struct state *);
151 static void specialcolors(struct nfa *);
152 static long optimize(struct nfa *, FILE *);
153 static void pullback(struct nfa *, FILE *);
154 static int pull(struct nfa *, struct arc *, struct state **);
155 static void pushfwd(struct nfa *, FILE *);
156 static int push(struct nfa *, struct arc *, struct state **);
157 
158 #define INCOMPATIBLE 1 /* destroys arc */
159 #define SATISFIED 2 /* constraint satisfied */
160 #define COMPATIBLE 3 /* compatible but not satisfied yet */
161 static int combine(struct arc *, struct arc *);
162 static void fixempties(struct nfa *, FILE *);
163 static struct state *emptyreachable(struct nfa *, struct state *,
164  struct state *, struct arc **);
165 static int isconstraintarc(struct arc *);
166 static int hasconstraintout(struct state *);
167 static void fixconstraintloops(struct nfa *, FILE *);
168 static int findconstraintloop(struct nfa *, struct state *);
169 static void breakconstraintloop(struct nfa *, struct state *);
170 static void clonesuccessorstates(struct nfa *, struct state *, struct state *,
171  struct state *, struct arc *,
172  char *, char *, int);
173 static void cleanup(struct nfa *);
174 static void markreachable(struct nfa *, struct state *, struct state *, struct state *);
175 static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
176 static long analyze(struct nfa *);
177 static void compact(struct nfa *, struct cnfa *);
178 static void carcsort(struct carc *, size_t);
179 static int carc_cmp(const void *, const void *);
180 static void freecnfa(struct cnfa *);
181 static void dumpnfa(struct nfa *, FILE *);
182 
183 #ifdef REG_DEBUG
184 static void dumpstate(struct state *, FILE *);
185 static void dumparcs(struct state *, FILE *);
186 static void dumparc(struct arc *, struct state *, FILE *);
187 static void dumpcnfa(struct cnfa *, FILE *);
188 static void dumpcstate(int, struct cnfa *, FILE *);
189 #endif
190 /* === regc_cvec.c === */
191 static struct cvec *newcvec(int, int);
192 static struct cvec *clearcvec(struct cvec *);
193 static void addchr(struct cvec *, chr);
194 static void addrange(struct cvec *, chr, chr);
195 static struct cvec *getcvec(struct vars *, int, int);
196 static void freecvec(struct cvec *);
197 
198 /* === regc_pg_locale.c === */
199 static int pg_wc_isdigit(pg_wchar c);
200 static int pg_wc_isalpha(pg_wchar c);
201 static int pg_wc_isalnum(pg_wchar c);
202 static int pg_wc_isupper(pg_wchar c);
203 static int pg_wc_islower(pg_wchar c);
204 static int pg_wc_isgraph(pg_wchar c);
205 static int pg_wc_isprint(pg_wchar c);
206 static int pg_wc_ispunct(pg_wchar c);
207 static int pg_wc_isspace(pg_wchar c);
210 
211 /* === regc_locale.c === */
212 static chr element(struct vars *, const chr *, const chr *);
213 static struct cvec *range(struct vars *, chr, chr, int);
214 static int before(chr, chr);
215 static struct cvec *eclass(struct vars *, chr, int);
216 static struct cvec *cclass(struct vars *, const chr *, const chr *, int);
217 static int cclass_column_index(struct colormap *, chr);
218 static struct cvec *allcases(struct vars *, chr);
219 static int cmp(const chr *, const chr *, size_t);
220 static int casecmp(const chr *, const chr *, size_t);
221 
222 
223 /* internal variables, bundled for easy passing around */
224 struct vars
225 {
227  const chr *now; /* scan pointer into string */
228  const chr *stop; /* end of string */
229  const chr *savenow; /* saved now and stop for "subroutine call" */
230  const chr *savestop;
231  int err; /* error code (0 if none) */
232  int cflags; /* copy of compile flags */
233  int lasttype; /* type of previous token */
234  int nexttype; /* type of next token */
235  chr nextvalue; /* value (if any) of next token */
236  int lexcon; /* lexical context type (see lex.c) */
237  int nsubexp; /* subexpression count */
238  struct subre **subs; /* subRE pointer vector */
239  size_t nsubs; /* length of vector */
240  struct subre *sub10[10]; /* initial vector, enough for most */
241  struct nfa *nfa; /* the NFA */
242  struct colormap *cm; /* character color map */
243  color nlcolor; /* color of newline */
244  struct state *wordchrs; /* state in nfa holding word-char outarcs */
245  struct subre *tree; /* subexpression tree */
246  struct subre *treechain; /* all tree nodes allocated */
247  struct subre *treefree; /* any free tree nodes */
248  int ntree; /* number of tree nodes, plus one */
249  struct cvec *cv; /* interface cvec */
250  struct cvec *cv2; /* utility cvec */
251  struct subre *lacons; /* lookaround-constraint vector */
252  int nlacons; /* size of lacons[]; note that only slots
253  * numbered 1 .. nlacons-1 are used */
254  size_t spaceused; /* approx. space used for compilation */
255 };
256 
257 /* parsing macros; most know that `v' is the struct vars pointer */
258 #define NEXT() (next(v)) /* advance by one token */
259 #define SEE(t) (v->nexttype == (t)) /* is next token this? */
260 #define EAT(t) (SEE(t) && next(v)) /* if next is this, swallow it */
261 #define VISERR(vv) ((vv)->err != 0) /* have we seen an error yet? */
262 #define ISERR() VISERR(v)
263 #define VERR(vv,e) ((vv)->nexttype = EOS, \
264  (vv)->err = ((vv)->err ? (vv)->err : (e)))
265 #define ERR(e) VERR(v, e) /* record an error */
266 #define NOERR() {if (ISERR()) return;} /* if error seen, return */
267 #define NOERRN() {if (ISERR()) return NULL;} /* NOERR with retval */
268 #define NOERRZ() {if (ISERR()) return 0;} /* NOERR with retval */
269 #define INSIST(c, e) do { if (!(c)) ERR(e); } while (0) /* error if c false */
270 #define NOTE(b) (v->re->re_info |= (b)) /* note visible condition */
271 #define EMPTYARC(x, y) newarc(v->nfa, EMPTY, 0, x, y)
272 
273 /* token type codes, some also used as NFA arc types */
274 #define EMPTY 'n' /* no token present */
275 #define EOS 'e' /* end of string */
276 #define PLAIN 'p' /* ordinary character */
277 #define DIGIT 'd' /* digit (in bound) */
278 #define BACKREF 'b' /* back reference */
279 #define COLLEL 'I' /* start of [. */
280 #define ECLASS 'E' /* start of [= */
281 #define CCLASS 'C' /* start of [: */
282 #define END 'X' /* end of [. [= [: */
283 #define RANGE 'R' /* - within [] which might be range delim. */
284 #define LACON 'L' /* lookaround constraint subRE */
285 #define AHEAD 'a' /* color-lookahead arc */
286 #define BEHIND 'r' /* color-lookbehind arc */
287 #define WBDRY 'w' /* word boundary constraint */
288 #define NWBDRY 'W' /* non-word-boundary constraint */
289 #define SBEGIN 'A' /* beginning of string (even if not BOL) */
290 #define SEND 'Z' /* end of string (even if not EOL) */
291 #define PREFER 'P' /* length preference */
292 
293 /* is an arc colored, and hence on a color chain? */
294 #define COLORED(a) \
295  ((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND)
296 
297 
298 /* static function list */
299 static const struct fns functions = {
300  rfree, /* regfree insides */
301  rcancelrequested, /* check for cancel request */
302  rstacktoodeep /* check for stack getting dangerously deep */
303 };
304 
305 
306 
307 /*
308  * pg_regcomp - compile regular expression
309  *
310  * Note: on failure, no resources remain allocated, so pg_regfree()
311  * need not be applied to re.
312  */
313 int
315  const chr *string,
316  size_t len,
317  int flags,
318  Oid collation)
319 {
320  struct vars var;
321  struct vars *v = &var;
322  struct guts *g;
323  int i;
324  size_t j;
325 
326 #ifdef REG_DEBUG
327  FILE *debug = (flags & REG_PROGRESS) ? stdout : (FILE *) NULL;
328 #else
329  FILE *debug = (FILE *) NULL;
330 #endif
331 
332 #define CNOERR() { if (ISERR()) return freev(v, v->err); }
333 
334  /* sanity checks */
335 
336  if (re == NULL || string == NULL)
337  return REG_INVARG;
338  if ((flags & REG_QUOTE) &&
339  (flags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE)))
340  return REG_INVARG;
341  if (!(flags & REG_EXTENDED) && (flags & REG_ADVF))
342  return REG_INVARG;
343 
344  /* Initialize locale-dependent support */
345  pg_set_regex_collation(collation);
346 
347  /* initial setup (after which freev() is callable) */
348  v->re = re;
349  v->now = string;
350  v->stop = v->now + len;
351  v->savenow = v->savestop = NULL;
352  v->err = 0;
353  v->cflags = flags;
354  v->nsubexp = 0;
355  v->subs = v->sub10;
356  v->nsubs = 10;
357  for (j = 0; j < v->nsubs; j++)
358  v->subs[j] = NULL;
359  v->nfa = NULL;
360  v->cm = NULL;
361  v->nlcolor = COLORLESS;
362  v->wordchrs = NULL;
363  v->tree = NULL;
364  v->treechain = NULL;
365  v->treefree = NULL;
366  v->cv = NULL;
367  v->cv2 = NULL;
368  v->lacons = NULL;
369  v->nlacons = 0;
370  v->spaceused = 0;
371  re->re_magic = REMAGIC;
372  re->re_info = 0; /* bits get set during parse */
373  re->re_csize = sizeof(chr);
374  re->re_collation = collation;
375  re->re_guts = NULL;
376  re->re_fns = VS(&functions);
377 
378  /* more complex setup, malloced things */
379  re->re_guts = VS(MALLOC(sizeof(struct guts)));
380  if (re->re_guts == NULL)
381  return freev(v, REG_ESPACE);
382  g = (struct guts *) re->re_guts;
383  g->tree = NULL;
384  initcm(v, &g->cmap);
385  v->cm = &g->cmap;
386  g->lacons = NULL;
387  g->nlacons = 0;
388  ZAPCNFA(g->search);
389  v->nfa = newnfa(v, v->cm, (struct nfa *) NULL);
390  CNOERR();
391  /* set up a reasonably-sized transient cvec for getcvec usage */
392  v->cv = newcvec(100, 20);
393  if (v->cv == NULL)
394  return freev(v, REG_ESPACE);
395 
396  /* parsing */
397  lexstart(v); /* also handles prefixes */
398  if ((v->cflags & REG_NLSTOP) || (v->cflags & REG_NLANCH))
399  {
400  /* assign newline a unique color */
401  v->nlcolor = subcolor(v->cm, newline());
402  okcolors(v->nfa, v->cm);
403  }
404  CNOERR();
405  v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
406  assert(SEE(EOS)); /* even if error; ISERR() => SEE(EOS) */
407  CNOERR();
408  assert(v->tree != NULL);
409 
410  /* finish setup of nfa and its subre tree */
411  specialcolors(v->nfa);
412  CNOERR();
413 #ifdef REG_DEBUG
414  if (debug != NULL)
415  {
416  fprintf(debug, "\n\n\n========= RAW ==========\n");
417  dumpnfa(v->nfa, debug);
418  dumpst(v->tree, debug, 1);
419  }
420 #endif
421  optst(v, v->tree);
422  v->ntree = numst(v->tree, 1);
423  markst(v->tree);
424  cleanst(v);
425 #ifdef REG_DEBUG
426  if (debug != NULL)
427  {
428  fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
429  dumpst(v->tree, debug, 1);
430  }
431 #endif
432 
433  /* build compacted NFAs for tree and lacons */
434  re->re_info |= nfatree(v, v->tree, debug);
435  CNOERR();
436  assert(v->nlacons == 0 || v->lacons != NULL);
437  for (i = 1; i < v->nlacons; i++)
438  {
439  struct subre *lasub = &v->lacons[i];
440 
441 #ifdef REG_DEBUG
442  if (debug != NULL)
443  fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
444 #endif
445 
446  /* Prepend .* to pattern if it's a lookbehind LACON */
447  nfanode(v, lasub, !LATYPE_IS_AHEAD(lasub->subno), debug);
448  }
449  CNOERR();
450  if (v->tree->flags & SHORTER)
452 
453  /* build compacted NFAs for tree, lacons, fast search */
454 #ifdef REG_DEBUG
455  if (debug != NULL)
456  fprintf(debug, "\n\n\n========= SEARCH ==========\n");
457 #endif
458  /* can sacrifice main NFA now, so use it as work area */
459  (DISCARD) optimize(v->nfa, debug);
460  CNOERR();
461  makesearch(v, v->nfa);
462  CNOERR();
463  compact(v->nfa, &g->search);
464  CNOERR();
465 
466  /* looks okay, package it up */
467  re->re_nsub = v->nsubexp;
468  v->re = NULL; /* freev no longer frees re */
469  g->magic = GUTSMAGIC;
470  g->cflags = v->cflags;
471  g->info = re->re_info;
472  g->nsub = re->re_nsub;
473  g->tree = v->tree;
474  v->tree = NULL;
475  g->ntree = v->ntree;
476  g->compare = (v->cflags & REG_ICASE) ? casecmp : cmp;
477  g->lacons = v->lacons;
478  v->lacons = NULL;
479  g->nlacons = v->nlacons;
480 
481 #ifdef REG_DEBUG
482  if (flags & REG_DUMP)
483  dump(re, stdout);
484 #endif
485 
486  assert(v->err == 0);
487  return freev(v, 0);
488 }
489 
490 /*
491  * moresubs - enlarge subRE vector
492  */
493 static void
494 moresubs(struct vars *v,
495  int wanted) /* want enough room for this one */
496 {
497  struct subre **p;
498  size_t n;
499 
500  assert(wanted > 0 && (size_t) wanted >= v->nsubs);
501  n = (size_t) wanted * 3 / 2 + 1;
502 
503  if (v->subs == v->sub10)
504  {
505  p = (struct subre **) MALLOC(n * sizeof(struct subre *));
506  if (p != NULL)
507  memcpy(VS(p), VS(v->subs),
508  v->nsubs * sizeof(struct subre *));
509  }
510  else
511  p = (struct subre **) REALLOC(v->subs, n * sizeof(struct subre *));
512  if (p == NULL)
513  {
514  ERR(REG_ESPACE);
515  return;
516  }
517  v->subs = p;
518  for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++)
519  *p = NULL;
520  assert(v->nsubs == n);
521  assert((size_t) wanted < v->nsubs);
522 }
523 
524 /*
525  * freev - free vars struct's substructures where necessary
526  *
527  * Optionally does error-number setting, and always returns error code
528  * (if any), to make error-handling code terser.
529  */
530 static int
531 freev(struct vars *v,
532  int err)
533 {
534  if (v->re != NULL)
535  rfree(v->re);
536  if (v->subs != v->sub10)
537  FREE(v->subs);
538  if (v->nfa != NULL)
539  freenfa(v->nfa);
540  if (v->tree != NULL)
541  freesubre(v, v->tree);
542  if (v->treechain != NULL)
543  cleanst(v);
544  if (v->cv != NULL)
545  freecvec(v->cv);
546  if (v->cv2 != NULL)
547  freecvec(v->cv2);
548  if (v->lacons != NULL)
549  freelacons(v->lacons, v->nlacons);
550  ERR(err); /* nop if err==0 */
551 
552  return v->err;
553 }
554 
555 /*
556  * makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
557  * NFA must have been optimize()d already.
558  */
559 static void
560 makesearch(struct vars *v,
561  struct nfa *nfa)
562 {
563  struct arc *a;
564  struct arc *b;
565  struct state *pre = nfa->pre;
566  struct state *s;
567  struct state *s2;
568  struct state *slist;
569 
570  /* no loops are needed if it's anchored */
571  for (a = pre->outs; a != NULL; a = a->outchain)
572  {
573  assert(a->type == PLAIN);
574  if (a->co != nfa->bos[0] && a->co != nfa->bos[1])
575  break;
576  }
577  if (a != NULL)
578  {
579  /* add implicit .* in front */
580  rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
581 
582  /* and ^* and \A* too -- not always necessary, but harmless */
583  newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
584  newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
585  }
586 
587  /*
588  * Now here's the subtle part. Because many REs have no lookback
589  * constraints, often knowing when you were in the pre state tells you
590  * little; it's the next state(s) that are informative. But some of them
591  * may have other inarcs, i.e. it may be possible to make actual progress
592  * and then return to one of them. We must de-optimize such cases,
593  * splitting each such state into progress and no-progress states.
594  */
595 
596  /* first, make a list of the states reachable from pre and elsewhere */
597  slist = NULL;
598  for (a = pre->outs; a != NULL; a = a->outchain)
599  {
600  s = a->to;
601  for (b = s->ins; b != NULL; b = b->inchain)
602  {
603  if (b->from != pre)
604  break;
605  }
606 
607  /*
608  * We want to mark states as being in the list already by having non
609  * NULL tmp fields, but we can't just store the old slist value in tmp
610  * because that doesn't work for the first such state. Instead, the
611  * first list entry gets its own address in tmp.
612  */
613  if (b != NULL && s->tmp == NULL)
614  {
615  s->tmp = (slist != NULL) ? slist : s;
616  slist = s;
617  }
618  }
619 
620  /* do the splits */
621  for (s = slist; s != NULL; s = s2)
622  {
623  s2 = newstate(nfa);
624  NOERR();
625  copyouts(nfa, s, s2);
626  NOERR();
627  for (a = s->ins; a != NULL; a = b)
628  {
629  b = a->inchain;
630  if (a->from != pre)
631  {
632  cparc(nfa, a, a->from, s2);
633  freearc(nfa, a);
634  }
635  }
636  s2 = (s->tmp != s) ? s->tmp : NULL;
637  s->tmp = NULL; /* clean up while we're at it */
638  }
639 }
640 
641 /*
642  * parse - parse an RE
643  *
644  * This is actually just the top level, which parses a bunch of branches
645  * tied together with '|'. They appear in the tree as the left children
646  * of a chain of '|' subres.
647  */
648 static struct subre *
649 parse(struct vars *v,
650  int stopper, /* EOS or ')' */
651  int type, /* LACON (lookaround subRE) or PLAIN */
652  struct state *init, /* initial state */
653  struct state *final) /* final state */
654 {
655  struct state *left; /* scaffolding for branch */
656  struct state *right;
657  struct subre *branches; /* top level */
658  struct subre *branch; /* current branch */
659  struct subre *t; /* temporary */
660  int firstbranch; /* is this the first branch? */
661 
662  assert(stopper == ')' || stopper == EOS);
663 
664  branches = subre(v, '|', LONGER, init, final);
665  NOERRN();
666  branch = branches;
667  firstbranch = 1;
668  do
669  { /* a branch */
670  if (!firstbranch)
671  {
672  /* need a place to hang it */
673  branch->right = subre(v, '|', LONGER, init, final);
674  NOERRN();
675  branch = branch->right;
676  }
677  firstbranch = 0;
678  left = newstate(v->nfa);
679  right = newstate(v->nfa);
680  NOERRN();
681  EMPTYARC(init, left);
682  EMPTYARC(right, final);
683  NOERRN();
684  branch->left = parsebranch(v, stopper, type, left, right, 0);
685  NOERRN();
686  branch->flags |= UP(branch->flags | branch->left->flags);
687  if ((branch->flags & ~branches->flags) != 0) /* new flags */
688  for (t = branches; t != branch; t = t->right)
689  t->flags |= branch->flags;
690  } while (EAT('|'));
691  assert(SEE(stopper) || SEE(EOS));
692 
693  if (!SEE(stopper))
694  {
695  assert(stopper == ')' && SEE(EOS));
696  ERR(REG_EPAREN);
697  }
698 
699  /* optimize out simple cases */
700  if (branch == branches)
701  { /* only one branch */
702  assert(branch->right == NULL);
703  t = branch->left;
704  branch->left = NULL;
705  freesubre(v, branches);
706  branches = t;
707  }
708  else if (!MESSY(branches->flags))
709  { /* no interesting innards */
710  freesubre(v, branches->left);
711  branches->left = NULL;
712  freesubre(v, branches->right);
713  branches->right = NULL;
714  branches->op = '=';
715  }
716 
717  return branches;
718 }
719 
720 /*
721  * parsebranch - parse one branch of an RE
722  *
723  * This mostly manages concatenation, working closely with parseqatom().
724  * Concatenated things are bundled up as much as possible, with separate
725  * ',' nodes introduced only when necessary due to substructure.
726  */
727 static struct subre *
728 parsebranch(struct vars *v,
729  int stopper, /* EOS or ')' */
730  int type, /* LACON (lookaround subRE) or PLAIN */
731  struct state *left, /* leftmost state */
732  struct state *right, /* rightmost state */
733  int partial) /* is this only part of a branch? */
734 {
735  struct state *lp; /* left end of current construct */
736  int seencontent; /* is there anything in this branch yet? */
737  struct subre *t;
738 
739  lp = left;
740  seencontent = 0;
741  t = subre(v, '=', 0, left, right); /* op '=' is tentative */
742  NOERRN();
743  while (!SEE('|') && !SEE(stopper) && !SEE(EOS))
744  {
745  if (seencontent)
746  { /* implicit concat operator */
747  lp = newstate(v->nfa);
748  NOERRN();
749  moveins(v->nfa, right, lp);
750  }
751  seencontent = 1;
752 
753  /* NB, recursion in parseqatom() may swallow rest of branch */
754  parseqatom(v, stopper, type, lp, right, t);
755  NOERRN();
756  }
757 
758  if (!seencontent)
759  { /* empty branch */
760  if (!partial)
761  NOTE(REG_UUNSPEC);
762  assert(lp == left);
763  EMPTYARC(left, right);
764  }
765 
766  return t;
767 }
768 
769 /*
770  * parseqatom - parse one quantified atom or constraint of an RE
771  *
772  * The bookkeeping near the end cooperates very closely with parsebranch();
773  * in particular, it contains a recursion that can involve parsing the rest
774  * of the branch, making this function's name somewhat inaccurate.
775  */
776 static void
777 parseqatom(struct vars *v,
778  int stopper, /* EOS or ')' */
779  int type, /* LACON (lookaround subRE) or PLAIN */
780  struct state *lp, /* left state to hang it on */
781  struct state *rp, /* right state to hang it on */
782  struct subre *top) /* subtree top */
783 {
784  struct state *s; /* temporaries for new states */
785  struct state *s2;
786 
787 #define ARCV(t, val) newarc(v->nfa, t, val, lp, rp)
788  int m,
789  n;
790  struct subre *atom; /* atom's subtree */
791  struct subre *t;
792  int cap; /* capturing parens? */
793  int latype; /* lookaround constraint type */
794  int subno; /* capturing-parens or backref number */
795  int atomtype;
796  int qprefer; /* quantifier short/long preference */
797  int f;
798  struct subre **atomp; /* where the pointer to atom is */
799 
800  /* initial bookkeeping */
801  atom = NULL;
802  assert(lp->nouts == 0); /* must string new code */
803  assert(rp->nins == 0); /* between lp and rp */
804  subno = 0; /* just to shut lint up */
805 
806  /* an atom or constraint... */
807  atomtype = v->nexttype;
808  switch (atomtype)
809  {
810  /* first, constraints, which end by returning */
811  case '^':
812  ARCV('^', 1);
813  if (v->cflags & REG_NLANCH)
814  ARCV(BEHIND, v->nlcolor);
815  NEXT();
816  return;
817  break;
818  case '$':
819  ARCV('$', 1);
820  if (v->cflags & REG_NLANCH)
821  ARCV(AHEAD, v->nlcolor);
822  NEXT();
823  return;
824  break;
825  case SBEGIN:
826  ARCV('^', 1); /* BOL */
827  ARCV('^', 0); /* or BOS */
828  NEXT();
829  return;
830  break;
831  case SEND:
832  ARCV('$', 1); /* EOL */
833  ARCV('$', 0); /* or EOS */
834  NEXT();
835  return;
836  break;
837  case '<':
838  wordchrs(v); /* does NEXT() */
839  s = newstate(v->nfa);
840  NOERR();
841  nonword(v, BEHIND, lp, s);
842  word(v, AHEAD, s, rp);
843  return;
844  break;
845  case '>':
846  wordchrs(v); /* does NEXT() */
847  s = newstate(v->nfa);
848  NOERR();
849  word(v, BEHIND, lp, s);
850  nonword(v, AHEAD, s, rp);
851  return;
852  break;
853  case WBDRY:
854  wordchrs(v); /* does NEXT() */
855  s = newstate(v->nfa);
856  NOERR();
857  nonword(v, BEHIND, lp, s);
858  word(v, AHEAD, s, rp);
859  s = newstate(v->nfa);
860  NOERR();
861  word(v, BEHIND, lp, s);
862  nonword(v, AHEAD, s, rp);
863  return;
864  break;
865  case NWBDRY:
866  wordchrs(v); /* does NEXT() */
867  s = newstate(v->nfa);
868  NOERR();
869  word(v, BEHIND, lp, s);
870  word(v, AHEAD, s, rp);
871  s = newstate(v->nfa);
872  NOERR();
873  nonword(v, BEHIND, lp, s);
874  nonword(v, AHEAD, s, rp);
875  return;
876  break;
877  case LACON: /* lookaround constraint */
878  latype = v->nextvalue;
879  NEXT();
880  s = newstate(v->nfa);
881  s2 = newstate(v->nfa);
882  NOERR();
883  t = parse(v, ')', LACON, s, s2);
884  freesubre(v, t); /* internal structure irrelevant */
885  NOERR();
886  assert(SEE(')'));
887  NEXT();
888  processlacon(v, s, s2, latype, lp, rp);
889  return;
890  break;
891  /* then errors, to get them out of the way */
892  case '*':
893  case '+':
894  case '?':
895  case '{':
896  ERR(REG_BADRPT);
897  return;
898  break;
899  default:
900  ERR(REG_ASSERT);
901  return;
902  break;
903  /* then plain characters, and minor variants on that theme */
904  case ')': /* unbalanced paren */
905  if ((v->cflags & REG_ADVANCED) != REG_EXTENDED)
906  {
907  ERR(REG_EPAREN);
908  return;
909  }
910  /* legal in EREs due to specification botch */
911  NOTE(REG_UPBOTCH);
912  /* fall through into case PLAIN */
913  /* FALLTHROUGH */
914  case PLAIN:
915  onechr(v, v->nextvalue, lp, rp);
916  okcolors(v->nfa, v->cm);
917  NOERR();
918  NEXT();
919  break;
920  case '[':
921  if (v->nextvalue == 1)
922  bracket(v, lp, rp);
923  else
924  cbracket(v, lp, rp);
925  assert(SEE(']') || ISERR());
926  NEXT();
927  break;
928  case '.':
929  rainbow(v->nfa, v->cm, PLAIN,
930  (v->cflags & REG_NLSTOP) ? v->nlcolor : COLORLESS,
931  lp, rp);
932  NEXT();
933  break;
934  /* and finally the ugly stuff */
935  case '(': /* value flags as capturing or non */
936  cap = (type == LACON) ? 0 : v->nextvalue;
937  if (cap)
938  {
939  v->nsubexp++;
940  subno = v->nsubexp;
941  if ((size_t) subno >= v->nsubs)
942  moresubs(v, subno);
943  assert((size_t) subno < v->nsubs);
944  }
945  else
946  atomtype = PLAIN; /* something that's not '(' */
947  NEXT();
948  /* need new endpoints because tree will contain pointers */
949  s = newstate(v->nfa);
950  s2 = newstate(v->nfa);
951  NOERR();
952  EMPTYARC(lp, s);
953  EMPTYARC(s2, rp);
954  NOERR();
955  atom = parse(v, ')', type, s, s2);
956  assert(SEE(')') || ISERR());
957  NEXT();
958  NOERR();
959  if (cap)
960  {
961  v->subs[subno] = atom;
962  t = subre(v, '(', atom->flags | CAP, lp, rp);
963  NOERR();
964  t->subno = subno;
965  t->left = atom;
966  atom = t;
967  }
968  /* postpone everything else pending possible {0} */
969  break;
970  case BACKREF: /* the Feature From The Black Lagoon */
971  INSIST(type != LACON, REG_ESUBREG);
972  INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
973  INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
974  NOERR();
975  assert(v->nextvalue > 0);
976  atom = subre(v, 'b', BACKR, lp, rp);
977  NOERR();
978  subno = v->nextvalue;
979  atom->subno = subno;
980  EMPTYARC(lp, rp); /* temporarily, so there's something */
981  NEXT();
982  break;
983  }
984 
985  /* ...and an atom may be followed by a quantifier */
986  switch (v->nexttype)
987  {
988  case '*':
989  m = 0;
990  n = DUPINF;
991  qprefer = (v->nextvalue) ? LONGER : SHORTER;
992  NEXT();
993  break;
994  case '+':
995  m = 1;
996  n = DUPINF;
997  qprefer = (v->nextvalue) ? LONGER : SHORTER;
998  NEXT();
999  break;
1000  case '?':
1001  m = 0;
1002  n = 1;
1003  qprefer = (v->nextvalue) ? LONGER : SHORTER;
1004  NEXT();
1005  break;
1006  case '{':
1007  NEXT();
1008  m = scannum(v);
1009  if (EAT(','))
1010  {
1011  if (SEE(DIGIT))
1012  n = scannum(v);
1013  else
1014  n = DUPINF;
1015  if (m > n)
1016  {
1017  ERR(REG_BADBR);
1018  return;
1019  }
1020  /* {m,n} exercises preference, even if it's {m,m} */
1021  qprefer = (v->nextvalue) ? LONGER : SHORTER;
1022  }
1023  else
1024  {
1025  n = m;
1026  /* {m} passes operand's preference through */
1027  qprefer = 0;
1028  }
1029  if (!SEE('}'))
1030  { /* catches errors too */
1031  ERR(REG_BADBR);
1032  return;
1033  }
1034  NEXT();
1035  break;
1036  default: /* no quantifier */
1037  m = n = 1;
1038  qprefer = 0;
1039  break;
1040  }
1041 
1042  /* annoying special case: {0} or {0,0} cancels everything */
1043  if (m == 0 && n == 0)
1044  {
1045  if (atom != NULL)
1046  freesubre(v, atom);
1047  if (atomtype == '(')
1048  v->subs[subno] = NULL;
1049  delsub(v->nfa, lp, rp);
1050  EMPTYARC(lp, rp);
1051  return;
1052  }
1053 
1054  /* if not a messy case, avoid hard part */
1055  assert(!MESSY(top->flags));
1056  f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
1057  if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f)))
1058  {
1059  if (!(m == 1 && n == 1))
1060  repeat(v, lp, rp, m, n);
1061  if (atom != NULL)
1062  freesubre(v, atom);
1063  top->flags = f;
1064  return;
1065  }
1066 
1067  /*
1068  * hard part: something messy
1069  *
1070  * That is, capturing parens, back reference, short/long clash, or an atom
1071  * with substructure containing one of those.
1072  */
1073 
1074  /* now we'll need a subre for the contents even if they're boring */
1075  if (atom == NULL)
1076  {
1077  atom = subre(v, '=', 0, lp, rp);
1078  NOERR();
1079  }
1080 
1081  /*----------
1082  * Prepare a general-purpose state skeleton.
1083  *
1084  * In the no-backrefs case, we want this:
1085  *
1086  * [lp] ---> [s] ---prefix---> [begin] ---atom---> [end] ---rest---> [rp]
1087  *
1088  * where prefix is some repetitions of atom. In the general case we need
1089  *
1090  * [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp]
1091  *
1092  * where the iterator wraps around [begin] ---atom---> [end]
1093  *
1094  * We make the s state here for both cases; s2 is made below if needed
1095  *----------
1096  */
1097  s = newstate(v->nfa); /* first, new endpoints for the atom */
1098  s2 = newstate(v->nfa);
1099  NOERR();
1100  moveouts(v->nfa, lp, s);
1101  moveins(v->nfa, rp, s2);
1102  NOERR();
1103  atom->begin = s;
1104  atom->end = s2;
1105  s = newstate(v->nfa); /* set up starting state */
1106  NOERR();
1107  EMPTYARC(lp, s);
1108  NOERR();
1109 
1110  /* break remaining subRE into x{...} and what follows */
1111  t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
1112  NOERR();
1113  t->left = atom;
1114  atomp = &t->left;
1115 
1116  /* here we should recurse... but we must postpone that to the end */
1117 
1118  /* split top into prefix and remaining */
1119  assert(top->op == '=' && top->left == NULL && top->right == NULL);
1120  top->left = subre(v, '=', top->flags, top->begin, lp);
1121  NOERR();
1122  top->op = '.';
1123  top->right = t;
1124 
1125  /* if it's a backref, now is the time to replicate the subNFA */
1126  if (atomtype == BACKREF)
1127  {
1128  assert(atom->begin->nouts == 1); /* just the EMPTY */
1129  delsub(v->nfa, atom->begin, atom->end);
1130  assert(v->subs[subno] != NULL);
1131 
1132  /*
1133  * And here's why the recursion got postponed: it must wait until the
1134  * skeleton is filled in, because it may hit a backref that wants to
1135  * copy the filled-in skeleton.
1136  */
1137  dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
1138  atom->begin, atom->end);
1139  NOERR();
1140  }
1141 
1142  /*
1143  * It's quantifier time. If the atom is just a backref, we'll let it deal
1144  * with quantifiers internally.
1145  */
1146  if (atomtype == BACKREF)
1147  {
1148  /* special case: backrefs have internal quantifiers */
1149  EMPTYARC(s, atom->begin); /* empty prefix */
1150  /* just stuff everything into atom */
1151  repeat(v, atom->begin, atom->end, m, n);
1152  atom->min = (short) m;
1153  atom->max = (short) n;
1154  atom->flags |= COMBINE(qprefer, atom->flags);
1155  /* rest of branch can be strung starting from atom->end */
1156  s2 = atom->end;
1157  }
1158  else if (m == 1 && n == 1)
1159  {
1160  /* no/vacuous quantifier: done */
1161  EMPTYARC(s, atom->begin); /* empty prefix */
1162  /* rest of branch can be strung starting from atom->end */
1163  s2 = atom->end;
1164  }
1165  else if (m > 0 && !(atom->flags & BACKR))
1166  {
1167  /*
1168  * If there's no backrefs involved, we can turn x{m,n} into
1169  * x{m-1,n-1}x, with capturing parens in only the second x. This is
1170  * valid because we only care about capturing matches from the final
1171  * iteration of the quantifier. It's a win because we can implement
1172  * the backref-free left side as a plain DFA node, since we don't
1173  * really care where its submatches are.
1174  */
1175  dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
1176  assert(m >= 1 && m != DUPINF && n >= 1);
1177  repeat(v, s, atom->begin, m - 1, (n == DUPINF) ? n : n - 1);
1178  f = COMBINE(qprefer, atom->flags);
1179  t = subre(v, '.', f, s, atom->end); /* prefix and atom */
1180  NOERR();
1181  t->left = subre(v, '=', PREF(f), s, atom->begin);
1182  NOERR();
1183  t->right = atom;
1184  *atomp = t;
1185  /* rest of branch can be strung starting from atom->end */
1186  s2 = atom->end;
1187  }
1188  else
1189  {
1190  /* general case: need an iteration node */
1191  s2 = newstate(v->nfa);
1192  NOERR();
1193  moveouts(v->nfa, atom->end, s2);
1194  NOERR();
1195  dupnfa(v->nfa, atom->begin, atom->end, s, s2);
1196  repeat(v, s, s2, m, n);
1197  f = COMBINE(qprefer, atom->flags);
1198  t = subre(v, '*', f, s, s2);
1199  NOERR();
1200  t->min = (short) m;
1201  t->max = (short) n;
1202  t->left = atom;
1203  *atomp = t;
1204  /* rest of branch is to be strung from iteration's end state */
1205  }
1206 
1207  /* and finally, look after that postponed recursion */
1208  t = top->right;
1209  if (!(SEE('|') || SEE(stopper) || SEE(EOS)))
1210  t->right = parsebranch(v, stopper, type, s2, rp, 1);
1211  else
1212  {
1213  EMPTYARC(s2, rp);
1214  t->right = subre(v, '=', 0, s2, rp);
1215  }
1216  NOERR();
1217  assert(SEE('|') || SEE(stopper) || SEE(EOS));
1218  t->flags |= COMBINE(t->flags, t->right->flags);
1219  top->flags |= COMBINE(top->flags, t->flags);
1220 }
1221 
1222 /*
1223  * nonword - generate arcs for non-word-character ahead or behind
1224  */
1225 static void
1226 nonword(struct vars *v,
1227  int dir, /* AHEAD or BEHIND */
1228  struct state *lp,
1229  struct state *rp)
1230 {
1231  int anchor = (dir == AHEAD) ? '$' : '^';
1232 
1233  assert(dir == AHEAD || dir == BEHIND);
1234  newarc(v->nfa, anchor, 1, lp, rp);
1235  newarc(v->nfa, anchor, 0, lp, rp);
1236  colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
1237  /* (no need for special attention to \n) */
1238 }
1239 
1240 /*
1241  * word - generate arcs for word character ahead or behind
1242  */
1243 static void
1244 word(struct vars *v,
1245  int dir, /* AHEAD or BEHIND */
1246  struct state *lp,
1247  struct state *rp)
1248 {
1249  assert(dir == AHEAD || dir == BEHIND);
1250  cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
1251  /* (no need for special attention to \n) */
1252 }
1253 
1254 /*
1255  * scannum - scan a number
1256  */
1257 static int /* value, <= DUPMAX */
1258 scannum(struct vars *v)
1259 {
1260  int n = 0;
1261 
1262  while (SEE(DIGIT) && n < DUPMAX)
1263  {
1264  n = n * 10 + v->nextvalue;
1265  NEXT();
1266  }
1267  if (SEE(DIGIT) || n > DUPMAX)
1268  {
1269  ERR(REG_BADBR);
1270  return 0;
1271  }
1272  return n;
1273 }
1274 
1275 /*
1276  * repeat - replicate subNFA for quantifiers
1277  *
1278  * The sub-NFA strung from lp to rp is modified to represent m to n
1279  * repetitions of its initial contents.
1280  *
1281  * The duplication sequences used here are chosen carefully so that any
1282  * pointers starting out pointing into the subexpression end up pointing into
1283  * the last occurrence. (Note that it may not be strung between the same
1284  * left and right end states, however!) This used to be important for the
1285  * subRE tree, although the important bits are now handled by the in-line
1286  * code in parse(), and when this is called, it doesn't matter any more.
1287  */
1288 static void
1289 repeat(struct vars *v,
1290  struct state *lp,
1291  struct state *rp,
1292  int m,
1293  int n)
1294 {
1295 #define SOME 2
1296 #define INF 3
1297 #define PAIR(x, y) ((x)*4 + (y))
1298 #define REDUCE(x) ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) )
1299  const int rm = REDUCE(m);
1300  const int rn = REDUCE(n);
1301  struct state *s;
1302  struct state *s2;
1303 
1304  switch (PAIR(rm, rn))
1305  {
1306  case PAIR(0, 0): /* empty string */
1307  delsub(v->nfa, lp, rp);
1308  EMPTYARC(lp, rp);
1309  break;
1310  case PAIR(0, 1): /* do as x| */
1311  EMPTYARC(lp, rp);
1312  break;
1313  case PAIR(0, SOME): /* do as x{1,n}| */
1314  repeat(v, lp, rp, 1, n);
1315  NOERR();
1316  EMPTYARC(lp, rp);
1317  break;
1318  case PAIR(0, INF): /* loop x around */
1319  s = newstate(v->nfa);
1320  NOERR();
1321  moveouts(v->nfa, lp, s);
1322  moveins(v->nfa, rp, s);
1323  EMPTYARC(lp, s);
1324  EMPTYARC(s, rp);
1325  break;
1326  case PAIR(1, 1): /* no action required */
1327  break;
1328  case PAIR(1, SOME): /* do as x{0,n-1}x = (x{1,n-1}|)x */
1329  s = newstate(v->nfa);
1330  NOERR();
1331  moveouts(v->nfa, lp, s);
1332  dupnfa(v->nfa, s, rp, lp, s);
1333  NOERR();
1334  repeat(v, lp, s, 1, n - 1);
1335  NOERR();
1336  EMPTYARC(lp, s);
1337  break;
1338  case PAIR(1, INF): /* add loopback arc */
1339  s = newstate(v->nfa);
1340  s2 = newstate(v->nfa);
1341  NOERR();
1342  moveouts(v->nfa, lp, s);
1343  moveins(v->nfa, rp, s2);
1344  EMPTYARC(lp, s);
1345  EMPTYARC(s2, rp);
1346  EMPTYARC(s2, s);
1347  break;
1348  case PAIR(SOME, SOME): /* do as x{m-1,n-1}x */
1349  s = newstate(v->nfa);
1350  NOERR();
1351  moveouts(v->nfa, lp, s);
1352  dupnfa(v->nfa, s, rp, lp, s);
1353  NOERR();
1354  repeat(v, lp, s, m - 1, n - 1);
1355  break;
1356  case PAIR(SOME, INF): /* do as x{m-1,}x */
1357  s = newstate(v->nfa);
1358  NOERR();
1359  moveouts(v->nfa, lp, s);
1360  dupnfa(v->nfa, s, rp, lp, s);
1361  NOERR();
1362  repeat(v, lp, s, m - 1, n);
1363  break;
1364  default:
1365  ERR(REG_ASSERT);
1366  break;
1367  }
1368 }
1369 
1370 /*
1371  * bracket - handle non-complemented bracket expression
1372  * Also called from cbracket for complemented bracket expressions.
1373  */
1374 static void
1375 bracket(struct vars *v,
1376  struct state *lp,
1377  struct state *rp)
1378 {
1379  assert(SEE('['));
1380  NEXT();
1381  while (!SEE(']') && !SEE(EOS))
1382  brackpart(v, lp, rp);
1383  assert(SEE(']') || ISERR());
1384  okcolors(v->nfa, v->cm);
1385 }
1386 
1387 /*
1388  * cbracket - handle complemented bracket expression
1389  * We do it by calling bracket() with dummy endpoints, and then complementing
1390  * the result. The alternative would be to invoke rainbow(), and then delete
1391  * arcs as the b.e. is seen... but that gets messy.
1392  */
1393 static void
1394 cbracket(struct vars *v,
1395  struct state *lp,
1396  struct state *rp)
1397 {
1398  struct state *left = newstate(v->nfa);
1399  struct state *right = newstate(v->nfa);
1400 
1401  NOERR();
1402  bracket(v, left, right);
1403  if (v->cflags & REG_NLSTOP)
1404  newarc(v->nfa, PLAIN, v->nlcolor, left, right);
1405  NOERR();
1406 
1407  assert(lp->nouts == 0); /* all outarcs will be ours */
1408 
1409  /*
1410  * Easy part of complementing, and all there is to do since the MCCE code
1411  * was removed.
1412  */
1413  colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
1414  NOERR();
1415  dropstate(v->nfa, left);
1416  assert(right->nins == 0);
1417  freestate(v->nfa, right);
1418 }
1419 
1420 /*
1421  * brackpart - handle one item (or range) within a bracket expression
1422  */
1423 static void
1424 brackpart(struct vars *v,
1425  struct state *lp,
1426  struct state *rp)
1427 {
1428  chr startc;
1429  chr endc;
1430  struct cvec *cv;
1431  const chr *startp;
1432  const chr *endp;
1433  chr c[1];
1434 
1435  /* parse something, get rid of special cases, take shortcuts */
1436  switch (v->nexttype)
1437  {
1438  case RANGE: /* a-b-c or other botch */
1439  ERR(REG_ERANGE);
1440  return;
1441  break;
1442  case PLAIN:
1443  c[0] = v->nextvalue;
1444  NEXT();
1445  /* shortcut for ordinary chr (not range) */
1446  if (!SEE(RANGE))
1447  {
1448  onechr(v, c[0], lp, rp);
1449  return;
1450  }
1451  startc = element(v, c, c + 1);
1452  NOERR();
1453  break;
1454  case COLLEL:
1455  startp = v->now;
1456  endp = scanplain(v);
1457  INSIST(startp < endp, REG_ECOLLATE);
1458  NOERR();
1459  startc = element(v, startp, endp);
1460  NOERR();
1461  break;
1462  case ECLASS:
1463  startp = v->now;
1464  endp = scanplain(v);
1465  INSIST(startp < endp, REG_ECOLLATE);
1466  NOERR();
1467  startc = element(v, startp, endp);
1468  NOERR();
1469  cv = eclass(v, startc, (v->cflags & REG_ICASE));
1470  NOERR();
1471  subcolorcvec(v, cv, lp, rp);
1472  return;
1473  break;
1474  case CCLASS:
1475  startp = v->now;
1476  endp = scanplain(v);
1477  INSIST(startp < endp, REG_ECTYPE);
1478  NOERR();
1479  cv = cclass(v, startp, endp, (v->cflags & REG_ICASE));
1480  NOERR();
1481  subcolorcvec(v, cv, lp, rp);
1482  return;
1483  break;
1484  default:
1485  ERR(REG_ASSERT);
1486  return;
1487  break;
1488  }
1489 
1490  if (SEE(RANGE))
1491  {
1492  NEXT();
1493  switch (v->nexttype)
1494  {
1495  case PLAIN:
1496  case RANGE:
1497  c[0] = v->nextvalue;
1498  NEXT();
1499  endc = element(v, c, c + 1);
1500  NOERR();
1501  break;
1502  case COLLEL:
1503  startp = v->now;
1504  endp = scanplain(v);
1505  INSIST(startp < endp, REG_ECOLLATE);
1506  NOERR();
1507  endc = element(v, startp, endp);
1508  NOERR();
1509  break;
1510  default:
1511  ERR(REG_ERANGE);
1512  return;
1513  break;
1514  }
1515  }
1516  else
1517  endc = startc;
1518 
1519  /*
1520  * Ranges are unportable. Actually, standard C does guarantee that digits
1521  * are contiguous, but making that an exception is just too complicated.
1522  */
1523  if (startc != endc)
1524  NOTE(REG_UUNPORT);
1525  cv = range(v, startc, endc, (v->cflags & REG_ICASE));
1526  NOERR();
1527  subcolorcvec(v, cv, lp, rp);
1528 }
1529 
1530 /*
1531  * scanplain - scan PLAIN contents of [. etc.
1532  *
1533  * Certain bits of trickery in lex.c know that this code does not try
1534  * to look past the final bracket of the [. etc.
1535  */
1536 static const chr * /* just after end of sequence */
1537 scanplain(struct vars *v)
1538 {
1539  const chr *endp;
1540 
1541  assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
1542  NEXT();
1543 
1544  endp = v->now;
1545  while (SEE(PLAIN))
1546  {
1547  endp = v->now;
1548  NEXT();
1549  }
1550 
1551  assert(SEE(END) || ISERR());
1552  NEXT();
1553 
1554  return endp;
1555 }
1556 
1557 /*
1558  * onechr - fill in arcs for a plain character, and possible case complements
1559  * This is mostly a shortcut for efficient handling of the common case.
1560  */
1561 static void
1562 onechr(struct vars *v,
1563  chr c,
1564  struct state *lp,
1565  struct state *rp)
1566 {
1567  if (!(v->cflags & REG_ICASE))
1568  {
1569  color lastsubcolor = COLORLESS;
1570 
1571  subcoloronechr(v, c, lp, rp, &lastsubcolor);
1572  return;
1573  }
1574 
1575  /* rats, need general case anyway... */
1576  subcolorcvec(v, allcases(v, c), lp, rp);
1577 }
1578 
1579 /*
1580  * wordchrs - set up word-chr list for word-boundary stuff, if needed
1581  *
1582  * The list is kept as a bunch of arcs between two dummy states; it's
1583  * disposed of by the unreachable-states sweep in NFA optimization.
1584  * Does NEXT(). Must not be called from any unusual lexical context.
1585  * This should be reconciled with the \w etc. handling in lex.c, and
1586  * should be cleaned up to reduce dependencies on input scanning.
1587  */
1588 static void
1589 wordchrs(struct vars *v)
1590 {
1591  struct state *left;
1592  struct state *right;
1593 
1594  if (v->wordchrs != NULL)
1595  {
1596  NEXT(); /* for consistency */
1597  return;
1598  }
1599 
1600  left = newstate(v->nfa);
1601  right = newstate(v->nfa);
1602  NOERR();
1603  /* fine point: implemented with [::], and lexer will set REG_ULOCALE */
1604  lexword(v);
1605  NEXT();
1606  assert(v->savenow != NULL && SEE('['));
1607  bracket(v, left, right);
1608  assert((v->savenow != NULL && SEE(']')) || ISERR());
1609  NEXT();
1610  NOERR();
1611  v->wordchrs = left;
1612 }
1613 
1614 /*
1615  * processlacon - generate the NFA representation of a LACON
1616  *
1617  * In the general case this is just newlacon() + newarc(), but some cases
1618  * can be optimized.
1619  */
1620 static void
1621 processlacon(struct vars *v,
1622  struct state *begin, /* start of parsed LACON sub-re */
1623  struct state *end, /* end of parsed LACON sub-re */
1624  int latype,
1625  struct state *lp, /* left state to hang it on */
1626  struct state *rp) /* right state to hang it on */
1627 {
1628  struct state *s1;
1629  int n;
1630 
1631  /*
1632  * Check for lookaround RE consisting of a single plain color arc (or set
1633  * of arcs); this would typically be a simple chr or a bracket expression.
1634  */
1635  s1 = single_color_transition(begin, end);
1636  switch (latype)
1637  {
1638  case LATYPE_AHEAD_POS:
1639  /* If lookahead RE is just colorset C, convert to AHEAD(C) */
1640  if (s1 != NULL)
1641  {
1642  cloneouts(v->nfa, s1, lp, rp, AHEAD);
1643  return;
1644  }
1645  break;
1646  case LATYPE_AHEAD_NEG:
1647  /* If lookahead RE is just colorset C, convert to AHEAD(^C)|$ */
1648  if (s1 != NULL)
1649  {
1650  colorcomplement(v->nfa, v->cm, AHEAD, s1, lp, rp);
1651  newarc(v->nfa, '$', 1, lp, rp);
1652  newarc(v->nfa, '$', 0, lp, rp);
1653  return;
1654  }
1655  break;
1656  case LATYPE_BEHIND_POS:
1657  /* If lookbehind RE is just colorset C, convert to BEHIND(C) */
1658  if (s1 != NULL)
1659  {
1660  cloneouts(v->nfa, s1, lp, rp, BEHIND);
1661  return;
1662  }
1663  break;
1664  case LATYPE_BEHIND_NEG:
1665  /* If lookbehind RE is just colorset C, convert to BEHIND(^C)|^ */
1666  if (s1 != NULL)
1667  {
1668  colorcomplement(v->nfa, v->cm, BEHIND, s1, lp, rp);
1669  newarc(v->nfa, '^', 1, lp, rp);
1670  newarc(v->nfa, '^', 0, lp, rp);
1671  return;
1672  }
1673  break;
1674  default:
1675  assert(NOTREACHED);
1676  }
1677 
1678  /* General case: we need a LACON subre and arc */
1679  n = newlacon(v, begin, end, latype);
1680  newarc(v->nfa, LACON, n, lp, rp);
1681 }
1682 
1683 /*
1684  * subre - allocate a subre
1685  */
1686 static struct subre *
1687 subre(struct vars *v,
1688  int op,
1689  int flags,
1690  struct state *begin,
1691  struct state *end)
1692 {
1693  struct subre *ret = v->treefree;
1694 
1695  /*
1696  * Checking for stack overflow here is sufficient to protect parse() and
1697  * its recursive subroutines.
1698  */
1699  if (STACK_TOO_DEEP(v->re))
1700  {
1701  ERR(REG_ETOOBIG);
1702  return NULL;
1703  }
1704 
1705  if (ret != NULL)
1706  v->treefree = ret->left;
1707  else
1708  {
1709  ret = (struct subre *) MALLOC(sizeof(struct subre));
1710  if (ret == NULL)
1711  {
1712  ERR(REG_ESPACE);
1713  return NULL;
1714  }
1715  ret->chain = v->treechain;
1716  v->treechain = ret;
1717  }
1718 
1719  assert(strchr("=b|.*(", op) != NULL);
1720 
1721  ret->op = op;
1722  ret->flags = flags;
1723  ret->id = 0; /* will be assigned later */
1724  ret->subno = 0;
1725  ret->min = ret->max = 1;
1726  ret->left = NULL;
1727  ret->right = NULL;
1728  ret->begin = begin;
1729  ret->end = end;
1730  ZAPCNFA(ret->cnfa);
1731 
1732  return ret;
1733 }
1734 
1735 /*
1736  * freesubre - free a subRE subtree
1737  */
1738 static void
1739 freesubre(struct vars *v, /* might be NULL */
1740  struct subre *sr)
1741 {
1742  if (sr == NULL)
1743  return;
1744 
1745  if (sr->left != NULL)
1746  freesubre(v, sr->left);
1747  if (sr->right != NULL)
1748  freesubre(v, sr->right);
1749 
1750  freesrnode(v, sr);
1751 }
1752 
1753 /*
1754  * freesrnode - free one node in a subRE subtree
1755  */
1756 static void
1757 freesrnode(struct vars *v, /* might be NULL */
1758  struct subre *sr)
1759 {
1760  if (sr == NULL)
1761  return;
1762 
1763  if (!NULLCNFA(sr->cnfa))
1764  freecnfa(&sr->cnfa);
1765  sr->flags = 0;
1766 
1767  if (v != NULL && v->treechain != NULL)
1768  {
1769  /* we're still parsing, maybe we can reuse the subre */
1770  sr->left = v->treefree;
1771  v->treefree = sr;
1772  }
1773  else
1774  FREE(sr);
1775 }
1776 
1777 /*
1778  * optst - optimize a subRE subtree
1779  */
1780 static void
1781 optst(struct vars *v,
1782  struct subre *t)
1783 {
1784  /*
1785  * DGP (2007-11-13): I assume it was the programmer's intent to eventually
1786  * come back and add code to optimize subRE trees, but the routine coded
1787  * just spends effort traversing the tree and doing nothing. We can do
1788  * nothing with less effort.
1789  */
1790  return;
1791 }
1792 
1793 /*
1794  * numst - number tree nodes (assigning "id" indexes)
1795  */
1796 static int /* next number */
1797 numst(struct subre *t,
1798  int start) /* starting point for subtree numbers */
1799 {
1800  int i;
1801 
1802  assert(t != NULL);
1803 
1804  i = start;
1805  t->id = (short) i++;
1806  if (t->left != NULL)
1807  i = numst(t->left, i);
1808  if (t->right != NULL)
1809  i = numst(t->right, i);
1810  return i;
1811 }
1812 
1813 /*
1814  * markst - mark tree nodes as INUSE
1815  *
1816  * Note: this is a great deal more subtle than it looks. During initial
1817  * parsing of a regex, all subres are linked into the treechain list;
1818  * discarded ones are also linked into the treefree list for possible reuse.
1819  * After we are done creating all subres required for a regex, we run markst()
1820  * then cleanst(), which results in discarding all subres not reachable from
1821  * v->tree. We then clear v->treechain, indicating that subres must be found
1822  * by descending from v->tree. This changes the behavior of freesubre(): it
1823  * will henceforth FREE() unwanted subres rather than sticking them into the
1824  * treefree list. (Doing that any earlier would result in dangling links in
1825  * the treechain list.) This all means that freev() will clean up correctly
1826  * if invoked before or after markst()+cleanst(); but it would not work if
1827  * called partway through this state conversion, so we mustn't error out
1828  * in or between these two functions.
1829  */
1830 static void
1831 markst(struct subre *t)
1832 {
1833  assert(t != NULL);
1834 
1835  t->flags |= INUSE;
1836  if (t->left != NULL)
1837  markst(t->left);
1838  if (t->right != NULL)
1839  markst(t->right);
1840 }
1841 
1842 /*
1843  * cleanst - free any tree nodes not marked INUSE
1844  */
1845 static void
1846 cleanst(struct vars *v)
1847 {
1848  struct subre *t;
1849  struct subre *next;
1850 
1851  for (t = v->treechain; t != NULL; t = next)
1852  {
1853  next = t->chain;
1854  if (!(t->flags & INUSE))
1855  FREE(t);
1856  }
1857  v->treechain = NULL;
1858  v->treefree = NULL; /* just on general principles */
1859 }
1860 
1861 /*
1862  * nfatree - turn a subRE subtree into a tree of compacted NFAs
1863  */
1864 static long /* optimize results from top node */
1865 nfatree(struct vars *v,
1866  struct subre *t,
1867  FILE *f) /* for debug output */
1868 {
1869  assert(t != NULL && t->begin != NULL);
1870 
1871  if (t->left != NULL)
1872  (DISCARD) nfatree(v, t->left, f);
1873  if (t->right != NULL)
1874  (DISCARD) nfatree(v, t->right, f);
1875 
1876  return nfanode(v, t, 0, f);
1877 }
1878 
1879 /*
1880  * nfanode - do one NFA for nfatree or lacons
1881  *
1882  * If converttosearch is true, apply makesearch() to the NFA.
1883  */
1884 static long /* optimize results */
1885 nfanode(struct vars *v,
1886  struct subre *t,
1887  int converttosearch,
1888  FILE *f) /* for debug output */
1889 {
1890  struct nfa *nfa;
1891  long ret = 0;
1892 
1893  assert(t->begin != NULL);
1894 
1895 #ifdef REG_DEBUG
1896  if (f != NULL)
1897  {
1898  char idbuf[50];
1899 
1900  fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
1901  stid(t, idbuf, sizeof(idbuf)));
1902  }
1903 #endif
1904  nfa = newnfa(v, v->cm, v->nfa);
1905  NOERRZ();
1906  dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
1907  if (!ISERR())
1908  specialcolors(nfa);
1909  if (!ISERR())
1910  ret = optimize(nfa, f);
1911  if (converttosearch && !ISERR())
1912  makesearch(v, nfa);
1913  if (!ISERR())
1914  compact(nfa, &t->cnfa);
1915 
1916  freenfa(nfa);
1917  return ret;
1918 }
1919 
1920 /*
1921  * newlacon - allocate a lookaround-constraint subRE
1922  */
1923 static int /* lacon number */
1924 newlacon(struct vars *v,
1925  struct state *begin,
1926  struct state *end,
1927  int latype)
1928 {
1929  int n;
1930  struct subre *newlacons;
1931  struct subre *sub;
1932 
1933  if (v->nlacons == 0)
1934  {
1935  n = 1; /* skip 0th */
1936  newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre));
1937  }
1938  else
1939  {
1940  n = v->nlacons;
1941  newlacons = (struct subre *) REALLOC(v->lacons,
1942  (n + 1) * sizeof(struct subre));
1943  }
1944  if (newlacons == NULL)
1945  {
1946  ERR(REG_ESPACE);
1947  return 0;
1948  }
1949  v->lacons = newlacons;
1950  v->nlacons = n + 1;
1951  sub = &v->lacons[n];
1952  sub->begin = begin;
1953  sub->end = end;
1954  sub->subno = latype;
1955  ZAPCNFA(sub->cnfa);
1956  return n;
1957 }
1958 
1959 /*
1960  * freelacons - free lookaround-constraint subRE vector
1961  */
1962 static void
1964  int n)
1965 {
1966  struct subre *sub;
1967  int i;
1968 
1969  assert(n > 0);
1970  for (sub = subs + 1, i = n - 1; i > 0; sub++, i--) /* no 0th */
1971  if (!NULLCNFA(sub->cnfa))
1972  freecnfa(&sub->cnfa);
1973  FREE(subs);
1974 }
1975 
1976 /*
1977  * rfree - free a whole RE (insides of regfree)
1978  */
1979 static void
1981 {
1982  struct guts *g;
1983 
1984  if (re == NULL || re->re_magic != REMAGIC)
1985  return;
1986 
1987  re->re_magic = 0; /* invalidate RE */
1988  g = (struct guts *) re->re_guts;
1989  re->re_guts = NULL;
1990  re->re_fns = NULL;
1991  if (g != NULL)
1992  {
1993  g->magic = 0;
1994  freecm(&g->cmap);
1995  if (g->tree != NULL)
1996  freesubre((struct vars *) NULL, g->tree);
1997  if (g->lacons != NULL)
1998  freelacons(g->lacons, g->nlacons);
1999  if (!NULLCNFA(g->search))
2000  freecnfa(&g->search);
2001  FREE(g);
2002  }
2003 }
2004 
2005 /*
2006  * rcancelrequested - check for external request to cancel regex operation
2007  *
2008  * Return nonzero to fail the operation with error code REG_CANCEL,
2009  * zero to keep going
2010  *
2011  * The current implementation is Postgres-specific. If we ever get around
2012  * to splitting the regex code out as a standalone library, there will need
2013  * to be some API to let applications define a callback function for this.
2014  */
2015 static int
2017 {
2019 }
2020 
2021 /*
2022  * rstacktoodeep - check for stack getting dangerously deep
2023  *
2024  * Return nonzero to fail the operation with error code REG_ETOOBIG,
2025  * zero to keep going
2026  *
2027  * The current implementation is Postgres-specific. If we ever get around
2028  * to splitting the regex code out as a standalone library, there will need
2029  * to be some API to let applications define a callback function for this.
2030  */
2031 static int
2033 {
2034  return stack_is_too_deep();
2035 }
2036 
2037 #ifdef REG_DEBUG
2038 
2039 /*
2040  * dump - dump an RE in human-readable form
2041  */
2042 static void
2043 dump(regex_t *re,
2044  FILE *f)
2045 {
2046  struct guts *g;
2047  int i;
2048 
2049  if (re->re_magic != REMAGIC)
2050  fprintf(f, "bad magic number (0x%x not 0x%x)\n", re->re_magic,
2051  REMAGIC);
2052  if (re->re_guts == NULL)
2053  {
2054  fprintf(f, "NULL guts!!!\n");
2055  return;
2056  }
2057  g = (struct guts *) re->re_guts;
2058  if (g->magic != GUTSMAGIC)
2059  fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", g->magic,
2060  GUTSMAGIC);
2061 
2062  fprintf(f, "\n\n\n========= DUMP ==========\n");
2063  fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
2064  (int) re->re_nsub, re->re_info, re->re_csize, g->ntree);
2065 
2066  dumpcolors(&g->cmap, f);
2067  if (!NULLCNFA(g->search))
2068  {
2069  fprintf(f, "\nsearch:\n");
2070  dumpcnfa(&g->search, f);
2071  }
2072  for (i = 1; i < g->nlacons; i++)
2073  {
2074  struct subre *lasub = &g->lacons[i];
2075  const char *latype;
2076 
2077  switch (lasub->subno)
2078  {
2079  case LATYPE_AHEAD_POS:
2080  latype = "positive lookahead";
2081  break;
2082  case LATYPE_AHEAD_NEG:
2083  latype = "negative lookahead";
2084  break;
2085  case LATYPE_BEHIND_POS:
2086  latype = "positive lookbehind";
2087  break;
2088  case LATYPE_BEHIND_NEG:
2089  latype = "negative lookbehind";
2090  break;
2091  default:
2092  latype = "???";
2093  break;
2094  }
2095  fprintf(f, "\nla%d (%s):\n", i, latype);
2096  dumpcnfa(&lasub->cnfa, f);
2097  }
2098  fprintf(f, "\n");
2099  dumpst(g->tree, f, 0);
2100 }
2101 
2102 /*
2103  * dumpst - dump a subRE tree
2104  */
2105 static void
2106 dumpst(struct subre *t,
2107  FILE *f,
2108  int nfapresent) /* is the original NFA still around? */
2109 {
2110  if (t == NULL)
2111  fprintf(f, "null tree\n");
2112  else
2113  stdump(t, f, nfapresent);
2114  fflush(f);
2115 }
2116 
2117 /*
2118  * stdump - recursive guts of dumpst
2119  */
2120 static void
2121 stdump(struct subre *t,
2122  FILE *f,
2123  int nfapresent) /* is the original NFA still around? */
2124 {
2125  char idbuf[50];
2126 
2127  fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
2128  if (t->flags & LONGER)
2129  fprintf(f, " longest");
2130  if (t->flags & SHORTER)
2131  fprintf(f, " shortest");
2132  if (t->flags & MIXED)
2133  fprintf(f, " hasmixed");
2134  if (t->flags & CAP)
2135  fprintf(f, " hascapture");
2136  if (t->flags & BACKR)
2137  fprintf(f, " hasbackref");
2138  if (!(t->flags & INUSE))
2139  fprintf(f, " UNUSED");
2140  if (t->subno != 0)
2141  fprintf(f, " (#%d)", t->subno);
2142  if (t->min != 1 || t->max != 1)
2143  {
2144  fprintf(f, " {%d,", t->min);
2145  if (t->max != DUPINF)
2146  fprintf(f, "%d", t->max);
2147  fprintf(f, "}");
2148  }
2149  if (nfapresent)
2150  fprintf(f, " %ld-%ld", (long) t->begin->no, (long) t->end->no);
2151  if (t->left != NULL)
2152  fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
2153  if (t->right != NULL)
2154  fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
2155  if (!NULLCNFA(t->cnfa))
2156  {
2157  fprintf(f, "\n");
2158  dumpcnfa(&t->cnfa, f);
2159  }
2160  fprintf(f, "\n");
2161  if (t->left != NULL)
2162  stdump(t->left, f, nfapresent);
2163  if (t->right != NULL)
2164  stdump(t->right, f, nfapresent);
2165 }
2166 
2167 /*
2168  * stid - identify a subtree node for dumping
2169  */
2170 static const char * /* points to buf or constant string */
2171 stid(struct subre *t,
2172  char *buf,
2173  size_t bufsize)
2174 {
2175  /* big enough for hex int or decimal t->id? */
2176  if (bufsize < sizeof(void *) * 2 + 3 || bufsize < sizeof(t->id) * 3 + 1)
2177  return "unable";
2178  if (t->id != 0)
2179  sprintf(buf, "%d", t->id);
2180  else
2181  sprintf(buf, "%p", t);
2182  return buf;
2183 }
2184 #endif /* REG_DEBUG */
2185 
2186 
2187 #include "regc_lex.c"
2188 #include "regc_color.c"
2189 #include "regc_nfa.c"
2190 #include "regc_cvec.c"
2191 #include "regc_pg_locale.c"
2192 #include "regc_locale.c"
#define REG_USHORTEST
Definition: regex.h:73
static color newcolor(struct colormap *)
#define EAT(t)
Definition: regcomp.c:260
static void subcolorcvec(struct vars *, struct cvec *, struct state *, struct state *)
#define RANGE
Definition: regcomp.c:283
static int scannum(struct vars *)
Definition: regcomp.c:1258
#define PAIR(x, y)
#define REG_ESUBREG
Definition: regex.h:143
static int isconstraintarc(struct arc *)
static chr newline(void)
static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int)
int nexttype
Definition: regcomp.c:234
static int pg_wc_islower(pg_wchar c)
struct subre * treefree
Definition: regcomp.c:247
int no
Definition: regguts.h:300
static void sortouts(struct nfa *, struct state *)
static void optst(struct vars *, struct subre *)
Definition: regcomp.c:1781
#define REG_NLSTOP
Definition: regex.h:109
static void cparc(struct nfa *, struct arc *, struct state *, struct state *)
static int lexescape(struct vars *)
struct state * from
Definition: regguts.h:280
#define END
Definition: regcomp.c:282
char * re_fns
Definition: regex.h:79
static int pg_wc_isgraph(pg_wchar c)
static void okcolors(struct nfa *, struct colormap *)
static void lexword(struct vars *)
#define CCLASS
Definition: regcomp.c:281
static void changearctarget(struct arc *, struct state *)
int type
Definition: regguts.h:278
static void destroystate(struct nfa *, struct state *)
static void freelacons(struct subre *, int)
Definition: regcomp.c:1963
static int numst(struct subre *, int)
Definition: regcomp.c:1797
static long optimize(struct nfa *, FILE *)
int ntree
Definition: regcomp.c:248
chr nextvalue
Definition: regcomp.c:235
static void rfree(regex_t *)
Definition: regcomp.c:1980
#define DUPMAX
Definition: regguts.h:93
static int brenext(struct vars *, chr)
#define REG_EPAREN
Definition: regex.h:145
struct subre * lacons
Definition: regguts.h:474
#define NOERRN()
Definition: regcomp.c:267
static chr element(struct vars *, const chr *, const chr *)
static int rcancelrequested(void)
Definition: regcomp.c:2016
static void bracket(struct vars *, struct state *, struct state *)
Definition: regcomp.c:1375
struct subre * tree
Definition: regguts.h:469
struct state * final
Definition: regguts.h:319
static long nfatree(struct vars *, struct subre *, FILE *)
Definition: regcomp.c:1865
struct subre * treechain
Definition: regcomp.c:246
static chr lexdigits(struct vars *, int, int, int)
#define REDUCE(x)
static void freecm(struct colormap *)
static void nonword(struct vars *, int, struct state *, struct state *)
Definition: regcomp.c:1226
static void mergeins(struct nfa *, struct state *, struct arc **, int)
static int pg_wc_isspace(pg_wchar c)
struct subre * right
Definition: regguts.h:432
#define REG_ESPACE
Definition: regex.h:149
static int cclass_column_index(struct colormap *, chr)
int subno
Definition: regguts.h:427
static int freev(struct vars *, int)
Definition: regcomp.c:531
Definition: regguts.h:276
static void carcsort(struct carc *, size_t)
static void specialcolors(struct nfa *)
#define REG_QUOTE
Definition: regex.h:104
static void prefixes(struct vars *)
#define NEXT()
Definition: regcomp.c:258
#define NULLCNFA(cnfa)
Definition: regguts.h:372
const chr * savenow
Definition: regcomp.c:229
#define MESSY(f)
Definition: regguts.h:422
static void markreachable(struct nfa *, struct state *, struct state *, struct state *)
#define LATYPE_BEHIND_POS
Definition: regguts.h:101
static struct cvec * newcvec(int, int)
static struct cvec * getcvec(struct vars *, int, int)
Definition: regguts.h:354
short color
Definition: regguts.h:134
static void colorchain(struct colormap *, struct arc *)
int nins
Definition: regguts.h:303
Definition: regguts.h:445
color nlcolor
Definition: regcomp.c:243
char op
Definition: regguts.h:410
static struct cvec * range(struct vars *, chr, chr, int)
static void fixempties(struct nfa *, FILE *)
static void lexnest(struct vars *, const chr *, const chr *)
int nlacons
Definition: regguts.h:475
static struct cvec * eclass(struct vars *, chr, int)
static struct subre * subre(struct vars *, int, int, struct state *, struct state *)
Definition: regcomp.c:1687
static void pushfwd(struct nfa *, FILE *)
static int hasconstraintout(struct state *)
int lasttype
Definition: regcomp.c:233
static struct state * emptyreachable(struct nfa *, struct state *, struct state *, struct arc **)
short min
Definition: regguts.h:429
#define REMAGIC
Definition: regguts.h:96
static void onechr(struct vars *, chr, struct state *, struct state *)
Definition: regcomp.c:1562
static color subcolor(struct colormap *, chr)
static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *)
Definition: regcomp.c:777
static void wordchrs(struct vars *)
Definition: regcomp.c:1589
struct state * begin
Definition: regguts.h:433
#define COMBINE(f1, f2)
Definition: regguts.h:425
Definition: regguts.h:315
static int hasnonemptyout(struct state *)
#define LATYPE_AHEAD_NEG
Definition: regguts.h:100
unsigned int Oid
Definition: postgres_ext.h:31
#define ISERR()
Definition: regcomp.c:262
static void subcoloronechr(struct vars *, chr, struct state *, struct state *, color *)
volatile bool QueryCancelPending
Definition: globals.c:33
#define BEHIND
Definition: regcomp.c:286
#define REG_ICASE
Definition: regex.h:106
int re_csize
Definition: regex.h:74
static void makesearch(struct vars *, struct nfa *)
Definition: regcomp.c:560
int pg_regcomp(regex_t *re, const chr *string, size_t len, int flags, Oid collation)
Definition: regcomp.c:314
static int sortouts_cmp(const void *, const void *)
static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *)
#define NOTREACHED
Definition: regguts.h:91
int nsubexp
Definition: regcomp.c:237
#define LATYPE_AHEAD_POS
Definition: regguts.h:99
chr * start
Definition: regexec.c:111
#define MALLOC(n)
Definition: regcustom.h:62
#define SOME
static struct state * single_color_transition(struct state *, struct state *)
#define REG_PROGRESS
Definition: regex.h:117
#define ERR(e)
Definition: regcomp.c:265
struct subre * chain
Definition: regguts.h:436
struct vars * v
Definition: regguts.h:328
int re_magic
Definition: regex.h:57
static void addchr(struct cvec *, chr)
struct cnfa search
Definition: regguts.h:470
static int push(struct nfa *, struct arc *, struct state **)
static void newhicolorcols(struct colormap *)
pg_wchar chr
Definition: regcustom.h:68
#define REALLOC(p, n)
Definition: regcustom.h:64
size_t re_nsub
Definition: regex.h:58
static void freesrnode(struct vars *, struct subre *)
Definition: regcomp.c:1757
static void duptraverse(struct nfa *, struct state *, struct state *)
struct colormap * cm
Definition: regcomp.c:242
#define ZAPCNFA(cnfa)
Definition: regguts.h:371
static void dumpnfa(struct nfa *, FILE *)
static int newhicolorrow(struct colormap *, int)
bool debug
Definition: pg_standby.c:48
char * s1
static void rainbow(struct nfa *, struct colormap *, int, color, struct state *, struct state *)
#define LACON
Definition: regcomp.c:284
regex_t * re
Definition: regcomp.c:226
int nlacons
Definition: regcomp.c:252
#define REG_BADBR
Definition: regex.h:147
int magic
Definition: regguts.h:464
static void uncolorchain(struct colormap *, struct arc *)
static void clonesuccessorstates(struct nfa *, struct state *, struct state *, struct state *, struct arc *, char *, char *, int)
char * c
#define REG_INVARG
Definition: regex.h:152
static char * buf
Definition: pg_test_fsync.c:67
static void markst(struct subre *)
Definition: regcomp.c:1831
static void fixconstraintloops(struct nfa *, FILE *)
static void freesubre(struct vars *, struct subre *)
Definition: regcomp.c:1739
#define REG_BADRPT
Definition: regex.h:150
static void processlacon(struct vars *, struct state *, struct state *, int, struct state *, struct state *)
Definition: regcomp.c:1621
static long analyze(struct nfa *)
static int next(struct vars *)
struct arc * outchain
Definition: regguts.h:282
char * flag(int b)
Definition: test-ctype.c:33
char flags
Definition: regguts.h:411
struct subre ** subs
Definition: regcomp.c:238
static struct nfa * newnfa(struct vars *, struct colormap *, struct nfa *)
char string[11]
Definition: preproc-type.c:46
color bos[2]
Definition: regguts.h:326
static int pg_wc_isupper(pg_wchar c)
struct colormap cmap
Definition: regguts.h:472
#define assert(TEST)
Definition: imath.c:37
static void freecolor(struct colormap *, color)
#define LATYPE_IS_AHEAD(la)
Definition: regguts.h:104
static void moveins(struct nfa *, struct state *, struct state *)
static pg_wchar pg_wc_tolower(pg_wchar c)
struct arc * outs
Definition: regguts.h:306
#define REG_NEWLINE
Definition: regex.h:111
static void moveouts(struct nfa *, struct state *, struct state *)
static const chr * scanplain(struct vars *)
Definition: regcomp.c:1537
#define REG_ADVANCED
Definition: regex.h:103
#define SEE(t)
Definition: regcomp.c:259
static int findconstraintloop(struct nfa *, struct state *)
#define REG_ECOLLATE
Definition: regex.h:140
static int pg_wc_isdigit(pg_wchar c)
struct subre * left
Definition: regguts.h:431
size_t nsubs
Definition: regcomp.c:239
static struct cvec * clearcvec(struct cvec *)
static void sortins(struct nfa *, struct state *)
static struct cvec * allcases(struct vars *, chr)
unsigned int pg_wchar
Definition: mbprint.c:31
static struct state * newstate(struct nfa *)
#define SBEGIN
Definition: regcomp.c:289
static void delsub(struct nfa *, struct state *, struct state *)
struct guts * g
Definition: regexec.c:106
#define BACKREF
Definition: regcomp.c:278
static void copyouts(struct nfa *, struct state *, struct state *)
struct state * tmp
Definition: regguts.h:308
Definition: regguts.h:256
int err
Definition: regcomp.c:231
static struct state * newfstate(struct nfa *, int flag)
static void copyins(struct nfa *, struct state *, struct state *)
#define LATYPE_BEHIND_NEG
Definition: regguts.h:102
static long nfanode(struct vars *, struct subre *, int, FILE *)
Definition: regcomp.c:1885
static int pg_wc_isalpha(pg_wchar c)
static struct arc * allocarc(struct nfa *, struct state *)
#define REG_EXTENDED
Definition: regex.h:101
struct nfa * nfa
Definition: regcomp.c:241
#define PREF(f)
Definition: regguts.h:423
struct cvec * cv
Definition: regcomp.c:249
static color subcolorhi(struct colormap *, color *)
static void freestate(struct nfa *, struct state *)
static int pull(struct nfa *, struct arc *, struct state **)
struct state * to
Definition: regguts.h:281
char * s2
struct cvec * cv2
Definition: regcomp.c:250
static chr chrnamed(struct vars *, const chr *, const chr *, chr)
#define REG_UUNPORT
Definition: regex.h:69
#define REG_ADVF
Definition: regex.h:102
const chr * savestop
Definition: regcomp.c:230
static void brackpart(struct vars *, struct state *, struct state *)
Definition: regcomp.c:1424
#define PLAIN
Definition: regcomp.c:276
#define EMPTYARC(x, y)
Definition: regcomp.c:271
struct state * wordchrs
Definition: regcomp.c:244
#define BACKR
Definition: regguts.h:416
long re_info
Definition: regex.h:59
static struct subre * parsebranch(struct vars *, int, int, struct state *, struct state *, int)
Definition: regcomp.c:728
#define REG_DUMP
Definition: regex.h:115
Definition: regguts.h:462
int ntree
Definition: regguts.h:471
static void cleanup(struct nfa *)
static color newsub(struct colormap *, color)
static int rstacktoodeep(void)
Definition: regcomp.c:2032
static void createarc(struct nfa *, int, color, struct state *, struct state *)
#define EOS
Definition: regcomp.c:275
volatile bool InterruptPending
Definition: globals.c:32
#define REG_ECTYPE
Definition: regex.h:141
static struct cvec * cclass(struct vars *, const chr *, const chr *, int)
static void cbracket(struct vars *, struct state *, struct state *)
Definition: regcomp.c:1394
color co
Definition: regguts.h:279
#define NWBDRY
Definition: regcomp.c:288
#define DUPINF
Definition: regguts.h:94
#define REG_ASSERT
Definition: regex.h:151
#define MIXED
Definition: regguts.h:414
static void deltraverse(struct nfa *, struct state *, struct state *)
#define GUTSMAGIC
Definition: regguts.h:465
#define REG_UUNSPEC
Definition: regex.h:68
void pg_set_regex_collation(Oid collation)
Definition: regguts.h:298
static void skip(struct vars *)
short max
Definition: regguts.h:430
static void newarc(struct nfa *, int, color, struct state *, struct state *)
static int carc_cmp(const void *, const void *)
static pg_wchar pg_wc_toupper(pg_wchar c)
#define REG_ERANGE
Definition: regex.h:148
static int pg_wc_isalnum(pg_wchar c)
const chr * now
Definition: regcomp.c:227
#define REG_NLANCH
Definition: regex.h:110
#define REG_ETOOBIG
Definition: regex.h:155
static const struct fns functions
Definition: regcomp.c:299
static void subcoloronerange(struct vars *, chr, chr, struct state *, struct state *, color *)
#define COLLEL
Definition: regcomp.c:279
static int sortins_cmp(const void *, const void *)
#define VS(x)
Definition: regguts.h:61
static int cmp(const chr *, const chr *, size_t)
struct state * end
Definition: regguts.h:434
static void initcm(struct vars *, struct colormap *)
static void subcoloronerow(struct vars *, int, struct state *, struct state *, color *)
#define INUSE
Definition: regguts.h:417
long info
Definition: regguts.h:467
Definition: regguts.h:408
#define NOTE(b)
Definition: regcomp.c:270
#define NOERRZ()
Definition: regcomp.c:268
int lexcon
Definition: regcomp.c:236
struct cnfa cnfa
Definition: regguts.h:435
#define CNOERR()
#define LONGER
Definition: regguts.h:412
static void pullback(struct nfa *, FILE *)
static void repeat(struct vars *, struct state *, struct state *, int, int)
Definition: regcomp.c:1289
static void word(struct vars *, int, struct state *, struct state *)
Definition: regcomp.c:1244
static void freecvec(struct cvec *)
const chr * stop
Definition: regcomp.c:228
char * re_guts
Definition: regex.h:78
int nouts
Definition: regguts.h:305
#define CAP
Definition: regguts.h:415
volatile bool ProcDiePending
Definition: globals.c:34
static int pg_wc_isprint(pg_wchar c)
static struct arc * findarc(struct state *, int, color)
int cflags
Definition: regguts.h:466
static int before(chr, chr)
static void addrange(struct cvec *, chr, chr)
#define NOERR()
Definition: regcomp.c:266
#define UP(f)
Definition: regguts.h:421
struct state * init
Definition: regguts.h:318
#define SEND
Definition: regcomp.c:290
int cflags
Definition: regcomp.c:232
size_t nsub
Definition: regguts.h:468
struct arc * inchain
Definition: regguts.h:285
static void lexstart(struct vars *)
static int casecmp(const chr *, const chr *, size_t)
#define ARCV(t, val)
static color pseudocolor(struct colormap *)
short id
Definition: regguts.h:426
#define SHORTER
Definition: regguts.h:413
int i
struct subre * sub10[10]
Definition: regcomp.c:240
#define COLORLESS
Definition: regguts.h:137
#define REG_EXPANDED
Definition: regex.h:108
#define DISCARD
Definition: regguts.h:58
static void freearc(struct nfa *, struct arc *)
static void freenfa(struct nfa *)
struct subre * tree
Definition: regcomp.c:245
static color maxcolor(struct colormap *)
#define WBDRY
Definition: regcomp.c:287
static void cleanst(struct vars *)
Definition: regcomp.c:1846
static void dropstate(struct nfa *, struct state *)
#define INF
size_t spaceused
Definition: regcomp.c:254
#define INSIST(c, e)
Definition: regcomp.c:269
struct subre * lacons
Definition: regcomp.c:251
static void freecnfa(struct cnfa *)
static int pg_wc_ispunct(pg_wchar c)
static void breakconstraintloop(struct nfa *, struct state *)
Definition: regcomp.c:224
Oid re_collation
Definition: regex.h:76
static void compact(struct nfa *, struct cnfa *)
Definition: regex.h:55
static void moresubs(struct vars *, int)
Definition: regcomp.c:494
#define FREE(size)
Definition: saslprep.c:51
static void cleartraverse(struct nfa *, struct state *)
#define STACK_TOO_DEEP(re)
Definition: regguts.h:455
#define DIGIT
Definition: regcomp.c:277
#define AHEAD
Definition: regcomp.c:285
struct arc * ins
Definition: regguts.h:304
static int newlacon(struct vars *, struct state *, struct state *, int)
Definition: regcomp.c:1924
static int combine(struct arc *, struct arc *)
struct state * pre
Definition: regguts.h:317
static void markcanreach(struct nfa *, struct state *, struct state *, struct state *)
static struct subre * parse(struct vars *, int, int, struct state *, struct state *)
Definition: regcomp.c:649
bool stack_is_too_deep(void)
Definition: postgres.c:3173
static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *)
Definition: regguts.h:348
#define ECLASS
Definition: regcomp.c:280
#define REG_UPBOTCH
Definition: regex.h:65