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 
292 /* is an arc colored, and hence on a color chain? */
293 #define COLORED(a) \
294  ((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND)
295 
296 
297 /* static function list */
298 static const struct fns functions = {
299  rfree, /* regfree insides */
300  rcancelrequested, /* check for cancel request */
301  rstacktoodeep /* check for stack getting dangerously deep */
302 };
303 
304 
305 
306 /*
307  * pg_regcomp - compile regular expression
308  *
309  * Note: on failure, no resources remain allocated, so pg_regfree()
310  * need not be applied to re.
311  */
312 int
314  const chr *string,
315  size_t len,
316  int flags,
317  Oid collation)
318 {
319  struct vars var;
320  struct vars *v = &var;
321  struct guts *g;
322  int i;
323  size_t j;
324 
325 #ifdef REG_DEBUG
326  FILE *debug = (flags & REG_PROGRESS) ? stdout : (FILE *) NULL;
327 #else
328  FILE *debug = (FILE *) NULL;
329 #endif
330 
331 #define CNOERR() { if (ISERR()) return freev(v, v->err); }
332 
333  /* sanity checks */
334 
335  if (re == NULL || string == NULL)
336  return REG_INVARG;
337  if ((flags & REG_QUOTE) &&
338  (flags & (REG_ADVANCED | REG_EXPANDED | REG_NEWLINE)))
339  return REG_INVARG;
340  if (!(flags & REG_EXTENDED) && (flags & REG_ADVF))
341  return REG_INVARG;
342 
343  /* Initialize locale-dependent support */
344  pg_set_regex_collation(collation);
345 
346  /* initial setup (after which freev() is callable) */
347  v->re = re;
348  v->now = string;
349  v->stop = v->now + len;
350  v->savenow = v->savestop = NULL;
351  v->err = 0;
352  v->cflags = flags;
353  v->nsubexp = 0;
354  v->subs = v->sub10;
355  v->nsubs = 10;
356  for (j = 0; j < v->nsubs; j++)
357  v->subs[j] = NULL;
358  v->nfa = NULL;
359  v->cm = NULL;
360  v->nlcolor = COLORLESS;
361  v->wordchrs = NULL;
362  v->tree = NULL;
363  v->treechain = NULL;
364  v->treefree = NULL;
365  v->cv = NULL;
366  v->cv2 = NULL;
367  v->lacons = NULL;
368  v->nlacons = 0;
369  v->spaceused = 0;
370  re->re_magic = REMAGIC;
371  re->re_info = 0; /* bits get set during parse */
372  re->re_csize = sizeof(chr);
373  re->re_collation = collation;
374  re->re_guts = NULL;
375  re->re_fns = VS(&functions);
376 
377  /* more complex setup, malloced things */
378  re->re_guts = VS(MALLOC(sizeof(struct guts)));
379  if (re->re_guts == NULL)
380  return freev(v, REG_ESPACE);
381  g = (struct guts *) re->re_guts;
382  g->tree = NULL;
383  initcm(v, &g->cmap);
384  v->cm = &g->cmap;
385  g->lacons = NULL;
386  g->nlacons = 0;
387  ZAPCNFA(g->search);
388  v->nfa = newnfa(v, v->cm, (struct nfa *) NULL);
389  CNOERR();
390  /* set up a reasonably-sized transient cvec for getcvec usage */
391  v->cv = newcvec(100, 20);
392  if (v->cv == NULL)
393  return freev(v, REG_ESPACE);
394 
395  /* parsing */
396  lexstart(v); /* also handles prefixes */
397  if ((v->cflags & REG_NLSTOP) || (v->cflags & REG_NLANCH))
398  {
399  /* assign newline a unique color */
400  v->nlcolor = subcolor(v->cm, newline());
401  okcolors(v->nfa, v->cm);
402  }
403  CNOERR();
404  v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
405  assert(SEE(EOS)); /* even if error; ISERR() => SEE(EOS) */
406  CNOERR();
407  assert(v->tree != NULL);
408 
409  /* finish setup of nfa and its subre tree */
410  specialcolors(v->nfa);
411  CNOERR();
412 #ifdef REG_DEBUG
413  if (debug != NULL)
414  {
415  fprintf(debug, "\n\n\n========= RAW ==========\n");
416  dumpnfa(v->nfa, debug);
417  dumpst(v->tree, debug, 1);
418  }
419 #endif
420  optst(v, v->tree);
421  v->ntree = numst(v->tree, 1);
422  markst(v->tree);
423  cleanst(v);
424 #ifdef REG_DEBUG
425  if (debug != NULL)
426  {
427  fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
428  dumpst(v->tree, debug, 1);
429  }
430 #endif
431 
432  /* build compacted NFAs for tree and lacons */
433  re->re_info |= nfatree(v, v->tree, debug);
434  CNOERR();
435  assert(v->nlacons == 0 || v->lacons != NULL);
436  for (i = 1; i < v->nlacons; i++)
437  {
438  struct subre *lasub = &v->lacons[i];
439 
440 #ifdef REG_DEBUG
441  if (debug != NULL)
442  fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
443 #endif
444 
445  /* Prepend .* to pattern if it's a lookbehind LACON */
446  nfanode(v, lasub, !LATYPE_IS_AHEAD(lasub->subno), debug);
447  }
448  CNOERR();
449  if (v->tree->flags & SHORTER)
451 
452  /* build compacted NFAs for tree, lacons, fast search */
453 #ifdef REG_DEBUG
454  if (debug != NULL)
455  fprintf(debug, "\n\n\n========= SEARCH ==========\n");
456 #endif
457  /* can sacrifice main NFA now, so use it as work area */
458  (DISCARD) optimize(v->nfa, debug);
459  CNOERR();
460  makesearch(v, v->nfa);
461  CNOERR();
462  compact(v->nfa, &g->search);
463  CNOERR();
464 
465  /* looks okay, package it up */
466  re->re_nsub = v->nsubexp;
467  v->re = NULL; /* freev no longer frees re */
468  g->magic = GUTSMAGIC;
469  g->cflags = v->cflags;
470  g->info = re->re_info;
471  g->nsub = re->re_nsub;
472  g->tree = v->tree;
473  v->tree = NULL;
474  g->ntree = v->ntree;
475  g->compare = (v->cflags & REG_ICASE) ? casecmp : cmp;
476  g->lacons = v->lacons;
477  v->lacons = NULL;
478  g->nlacons = v->nlacons;
479 
480 #ifdef REG_DEBUG
481  if (flags & REG_DUMP)
482  dump(re, stdout);
483 #endif
484 
485  assert(v->err == 0);
486  return freev(v, 0);
487 }
488 
489 /*
490  * moresubs - enlarge subRE vector
491  */
492 static void
493 moresubs(struct vars *v,
494  int wanted) /* want enough room for this one */
495 {
496  struct subre **p;
497  size_t n;
498 
499  assert(wanted > 0 && (size_t) wanted >= v->nsubs);
500  n = (size_t) wanted * 3 / 2 + 1;
501 
502  if (v->subs == v->sub10)
503  {
504  p = (struct subre **) MALLOC(n * sizeof(struct subre *));
505  if (p != NULL)
506  memcpy(VS(p), VS(v->subs),
507  v->nsubs * sizeof(struct subre *));
508  }
509  else
510  p = (struct subre **) REALLOC(v->subs, n * sizeof(struct subre *));
511  if (p == NULL)
512  {
513  ERR(REG_ESPACE);
514  return;
515  }
516  v->subs = p;
517  for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++)
518  *p = NULL;
519  assert(v->nsubs == n);
520  assert((size_t) wanted < v->nsubs);
521 }
522 
523 /*
524  * freev - free vars struct's substructures where necessary
525  *
526  * Optionally does error-number setting, and always returns error code
527  * (if any), to make error-handling code terser.
528  */
529 static int
530 freev(struct vars *v,
531  int err)
532 {
533  if (v->re != NULL)
534  rfree(v->re);
535  if (v->subs != v->sub10)
536  FREE(v->subs);
537  if (v->nfa != NULL)
538  freenfa(v->nfa);
539  if (v->tree != NULL)
540  freesubre(v, v->tree);
541  if (v->treechain != NULL)
542  cleanst(v);
543  if (v->cv != NULL)
544  freecvec(v->cv);
545  if (v->cv2 != NULL)
546  freecvec(v->cv2);
547  if (v->lacons != NULL)
548  freelacons(v->lacons, v->nlacons);
549  ERR(err); /* nop if err==0 */
550 
551  return v->err;
552 }
553 
554 /*
555  * makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
556  * NFA must have been optimize()d already.
557  */
558 static void
559 makesearch(struct vars *v,
560  struct nfa *nfa)
561 {
562  struct arc *a;
563  struct arc *b;
564  struct state *pre = nfa->pre;
565  struct state *s;
566  struct state *s2;
567  struct state *slist;
568 
569  /* no loops are needed if it's anchored */
570  for (a = pre->outs; a != NULL; a = a->outchain)
571  {
572  assert(a->type == PLAIN);
573  if (a->co != nfa->bos[0] && a->co != nfa->bos[1])
574  break;
575  }
576  if (a != NULL)
577  {
578  /* add implicit .* in front */
579  rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
580 
581  /* and ^* and \A* too -- not always necessary, but harmless */
582  newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
583  newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
584  }
585 
586  /*
587  * Now here's the subtle part. Because many REs have no lookback
588  * constraints, often knowing when you were in the pre state tells you
589  * little; it's the next state(s) that are informative. But some of them
590  * may have other inarcs, i.e. it may be possible to make actual progress
591  * and then return to one of them. We must de-optimize such cases,
592  * splitting each such state into progress and no-progress states.
593  */
594 
595  /* first, make a list of the states reachable from pre and elsewhere */
596  slist = NULL;
597  for (a = pre->outs; a != NULL; a = a->outchain)
598  {
599  s = a->to;
600  for (b = s->ins; b != NULL; b = b->inchain)
601  {
602  if (b->from != pre)
603  break;
604  }
605 
606  /*
607  * We want to mark states as being in the list already by having non
608  * NULL tmp fields, but we can't just store the old slist value in tmp
609  * because that doesn't work for the first such state. Instead, the
610  * first list entry gets its own address in tmp.
611  */
612  if (b != NULL && s->tmp == NULL)
613  {
614  s->tmp = (slist != NULL) ? slist : s;
615  slist = s;
616  }
617  }
618 
619  /* do the splits */
620  for (s = slist; s != NULL; s = s2)
621  {
622  s2 = newstate(nfa);
623  NOERR();
624  copyouts(nfa, s, s2);
625  NOERR();
626  for (a = s->ins; a != NULL; a = b)
627  {
628  b = a->inchain;
629  if (a->from != pre)
630  {
631  cparc(nfa, a, a->from, s2);
632  freearc(nfa, a);
633  }
634  }
635  s2 = (s->tmp != s) ? s->tmp : NULL;
636  s->tmp = NULL; /* clean up while we're at it */
637  }
638 }
639 
640 /*
641  * parse - parse an RE
642  *
643  * This is actually just the top level, which parses a bunch of branches
644  * tied together with '|'. They appear in the tree as the left children
645  * of a chain of '|' subres.
646  */
647 static struct subre *
648 parse(struct vars *v,
649  int stopper, /* EOS or ')' */
650  int type, /* LACON (lookaround subRE) or PLAIN */
651  struct state *init, /* initial state */
652  struct state *final) /* final state */
653 {
654  struct state *left; /* scaffolding for branch */
655  struct state *right;
656  struct subre *branches; /* top level */
657  struct subre *branch; /* current branch */
658  struct subre *t; /* temporary */
659  int firstbranch; /* is this the first branch? */
660 
661  assert(stopper == ')' || stopper == EOS);
662 
663  branches = subre(v, '|', LONGER, init, final);
664  NOERRN();
665  branch = branches;
666  firstbranch = 1;
667  do
668  { /* a branch */
669  if (!firstbranch)
670  {
671  /* need a place to hang it */
672  branch->right = subre(v, '|', LONGER, init, final);
673  NOERRN();
674  branch = branch->right;
675  }
676  firstbranch = 0;
677  left = newstate(v->nfa);
678  right = newstate(v->nfa);
679  NOERRN();
680  EMPTYARC(init, left);
681  EMPTYARC(right, final);
682  NOERRN();
683  branch->left = parsebranch(v, stopper, type, left, right, 0);
684  NOERRN();
685  branch->flags |= UP(branch->flags | branch->left->flags);
686  if ((branch->flags & ~branches->flags) != 0) /* new flags */
687  for (t = branches; t != branch; t = t->right)
688  t->flags |= branch->flags;
689  } while (EAT('|'));
690  assert(SEE(stopper) || SEE(EOS));
691 
692  if (!SEE(stopper))
693  {
694  assert(stopper == ')' && SEE(EOS));
695  ERR(REG_EPAREN);
696  }
697 
698  /* optimize out simple cases */
699  if (branch == branches)
700  { /* only one branch */
701  assert(branch->right == NULL);
702  t = branch->left;
703  branch->left = NULL;
704  freesubre(v, branches);
705  branches = t;
706  }
707  else if (!MESSY(branches->flags))
708  { /* no interesting innards */
709  freesubre(v, branches->left);
710  branches->left = NULL;
711  freesubre(v, branches->right);
712  branches->right = NULL;
713  branches->op = '=';
714  }
715 
716  return branches;
717 }
718 
719 /*
720  * parsebranch - parse one branch of an RE
721  *
722  * This mostly manages concatenation, working closely with parseqatom().
723  * Concatenated things are bundled up as much as possible, with separate
724  * ',' nodes introduced only when necessary due to substructure.
725  */
726 static struct subre *
727 parsebranch(struct vars *v,
728  int stopper, /* EOS or ')' */
729  int type, /* LACON (lookaround subRE) or PLAIN */
730  struct state *left, /* leftmost state */
731  struct state *right, /* rightmost state */
732  int partial) /* is this only part of a branch? */
733 {
734  struct state *lp; /* left end of current construct */
735  int seencontent; /* is there anything in this branch yet? */
736  struct subre *t;
737 
738  lp = left;
739  seencontent = 0;
740  t = subre(v, '=', 0, left, right); /* op '=' is tentative */
741  NOERRN();
742  while (!SEE('|') && !SEE(stopper) && !SEE(EOS))
743  {
744  if (seencontent)
745  { /* implicit concat operator */
746  lp = newstate(v->nfa);
747  NOERRN();
748  moveins(v->nfa, right, lp);
749  }
750  seencontent = 1;
751 
752  /* NB, recursion in parseqatom() may swallow rest of branch */
753  parseqatom(v, stopper, type, lp, right, t);
754  NOERRN();
755  }
756 
757  if (!seencontent)
758  { /* empty branch */
759  if (!partial)
760  NOTE(REG_UUNSPEC);
761  assert(lp == left);
762  EMPTYARC(left, right);
763  }
764 
765  return t;
766 }
767 
768 /*
769  * parseqatom - parse one quantified atom or constraint of an RE
770  *
771  * The bookkeeping near the end cooperates very closely with parsebranch();
772  * in particular, it contains a recursion that can involve parsing the rest
773  * of the branch, making this function's name somewhat inaccurate.
774  */
775 static void
776 parseqatom(struct vars *v,
777  int stopper, /* EOS or ')' */
778  int type, /* LACON (lookaround subRE) or PLAIN */
779  struct state *lp, /* left state to hang it on */
780  struct state *rp, /* right state to hang it on */
781  struct subre *top) /* subtree top */
782 {
783  struct state *s; /* temporaries for new states */
784  struct state *s2;
785 
786 #define ARCV(t, val) newarc(v->nfa, t, val, lp, rp)
787  int m,
788  n;
789  struct subre *atom; /* atom's subtree */
790  struct subre *t;
791  int cap; /* capturing parens? */
792  int latype; /* lookaround constraint type */
793  int subno; /* capturing-parens or backref number */
794  int atomtype;
795  int qprefer; /* quantifier short/long preference */
796  int f;
797  struct subre **atomp; /* where the pointer to atom is */
798 
799  /* initial bookkeeping */
800  atom = NULL;
801  assert(lp->nouts == 0); /* must string new code */
802  assert(rp->nins == 0); /* between lp and rp */
803  subno = 0; /* just to shut lint up */
804 
805  /* an atom or constraint... */
806  atomtype = v->nexttype;
807  switch (atomtype)
808  {
809  /* first, constraints, which end by returning */
810  case '^':
811  ARCV('^', 1);
812  if (v->cflags & REG_NLANCH)
813  ARCV(BEHIND, v->nlcolor);
814  NEXT();
815  return;
816  break;
817  case '$':
818  ARCV('$', 1);
819  if (v->cflags & REG_NLANCH)
820  ARCV(AHEAD, v->nlcolor);
821  NEXT();
822  return;
823  break;
824  case SBEGIN:
825  ARCV('^', 1); /* BOL */
826  ARCV('^', 0); /* or BOS */
827  NEXT();
828  return;
829  break;
830  case SEND:
831  ARCV('$', 1); /* EOL */
832  ARCV('$', 0); /* or EOS */
833  NEXT();
834  return;
835  break;
836  case '<':
837  wordchrs(v); /* does NEXT() */
838  s = newstate(v->nfa);
839  NOERR();
840  nonword(v, BEHIND, lp, s);
841  word(v, AHEAD, s, rp);
842  return;
843  break;
844  case '>':
845  wordchrs(v); /* does NEXT() */
846  s = newstate(v->nfa);
847  NOERR();
848  word(v, BEHIND, lp, s);
849  nonword(v, AHEAD, s, rp);
850  return;
851  break;
852  case WBDRY:
853  wordchrs(v); /* does NEXT() */
854  s = newstate(v->nfa);
855  NOERR();
856  nonword(v, BEHIND, lp, s);
857  word(v, AHEAD, s, rp);
858  s = newstate(v->nfa);
859  NOERR();
860  word(v, BEHIND, lp, s);
861  nonword(v, AHEAD, s, rp);
862  return;
863  break;
864  case NWBDRY:
865  wordchrs(v); /* does NEXT() */
866  s = newstate(v->nfa);
867  NOERR();
868  word(v, BEHIND, lp, s);
869  word(v, AHEAD, s, rp);
870  s = newstate(v->nfa);
871  NOERR();
872  nonword(v, BEHIND, lp, s);
873  nonword(v, AHEAD, s, rp);
874  return;
875  break;
876  case LACON: /* lookaround constraint */
877  latype = v->nextvalue;
878  NEXT();
879  s = newstate(v->nfa);
880  s2 = newstate(v->nfa);
881  NOERR();
882  t = parse(v, ')', LACON, s, s2);
883  freesubre(v, t); /* internal structure irrelevant */
884  NOERR();
885  assert(SEE(')'));
886  NEXT();
887  processlacon(v, s, s2, latype, lp, rp);
888  return;
889  break;
890  /* then errors, to get them out of the way */
891  case '*':
892  case '+':
893  case '?':
894  case '{':
895  ERR(REG_BADRPT);
896  return;
897  break;
898  default:
899  ERR(REG_ASSERT);
900  return;
901  break;
902  /* then plain characters, and minor variants on that theme */
903  case ')': /* unbalanced paren */
904  if ((v->cflags & REG_ADVANCED) != REG_EXTENDED)
905  {
906  ERR(REG_EPAREN);
907  return;
908  }
909  /* legal in EREs due to specification botch */
910  NOTE(REG_UPBOTCH);
911  /* fall through into case PLAIN */
912  /* FALLTHROUGH */
913  case PLAIN:
914  onechr(v, v->nextvalue, lp, rp);
915  okcolors(v->nfa, v->cm);
916  NOERR();
917  NEXT();
918  break;
919  case '[':
920  if (v->nextvalue == 1)
921  bracket(v, lp, rp);
922  else
923  cbracket(v, lp, rp);
924  assert(SEE(']') || ISERR());
925  NEXT();
926  break;
927  case '.':
928  rainbow(v->nfa, v->cm, PLAIN,
929  (v->cflags & REG_NLSTOP) ? v->nlcolor : COLORLESS,
930  lp, rp);
931  NEXT();
932  break;
933  /* and finally the ugly stuff */
934  case '(': /* value flags as capturing or non */
935  cap = (type == LACON) ? 0 : v->nextvalue;
936  if (cap)
937  {
938  v->nsubexp++;
939  subno = v->nsubexp;
940  if ((size_t) subno >= v->nsubs)
941  moresubs(v, subno);
942  assert((size_t) subno < v->nsubs);
943  }
944  else
945  atomtype = PLAIN; /* something that's not '(' */
946  NEXT();
947  /* need new endpoints because tree will contain pointers */
948  s = newstate(v->nfa);
949  s2 = newstate(v->nfa);
950  NOERR();
951  EMPTYARC(lp, s);
952  EMPTYARC(s2, rp);
953  NOERR();
954  atom = parse(v, ')', type, s, s2);
955  assert(SEE(')') || ISERR());
956  NEXT();
957  NOERR();
958  if (cap)
959  {
960  v->subs[subno] = atom;
961  t = subre(v, '(', atom->flags | CAP, lp, rp);
962  NOERR();
963  t->subno = subno;
964  t->left = atom;
965  atom = t;
966  }
967  /* postpone everything else pending possible {0} */
968  break;
969  case BACKREF: /* the Feature From The Black Lagoon */
970  INSIST(type != LACON, REG_ESUBREG);
971  INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
972  INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
973  NOERR();
974  assert(v->nextvalue > 0);
975  atom = subre(v, 'b', BACKR, lp, rp);
976  NOERR();
977  subno = v->nextvalue;
978  atom->subno = subno;
979  EMPTYARC(lp, rp); /* temporarily, so there's something */
980  NEXT();
981  break;
982  }
983 
984  /* ...and an atom may be followed by a quantifier */
985  switch (v->nexttype)
986  {
987  case '*':
988  m = 0;
989  n = DUPINF;
990  qprefer = (v->nextvalue) ? LONGER : SHORTER;
991  NEXT();
992  break;
993  case '+':
994  m = 1;
995  n = DUPINF;
996  qprefer = (v->nextvalue) ? LONGER : SHORTER;
997  NEXT();
998  break;
999  case '?':
1000  m = 0;
1001  n = 1;
1002  qprefer = (v->nextvalue) ? LONGER : SHORTER;
1003  NEXT();
1004  break;
1005  case '{':
1006  NEXT();
1007  m = scannum(v);
1008  if (EAT(','))
1009  {
1010  if (SEE(DIGIT))
1011  n = scannum(v);
1012  else
1013  n = DUPINF;
1014  if (m > n)
1015  {
1016  ERR(REG_BADBR);
1017  return;
1018  }
1019  /* {m,n} exercises preference, even if it's {m,m} */
1020  qprefer = (v->nextvalue) ? LONGER : SHORTER;
1021  }
1022  else
1023  {
1024  n = m;
1025  /* {m} passes operand's preference through */
1026  qprefer = 0;
1027  }
1028  if (!SEE('}'))
1029  { /* catches errors too */
1030  ERR(REG_BADBR);
1031  return;
1032  }
1033  NEXT();
1034  break;
1035  default: /* no quantifier */
1036  m = n = 1;
1037  qprefer = 0;
1038  break;
1039  }
1040 
1041  /* annoying special case: {0} or {0,0} cancels everything */
1042  if (m == 0 && n == 0)
1043  {
1044  if (atom != NULL)
1045  freesubre(v, atom);
1046  if (atomtype == '(')
1047  v->subs[subno] = NULL;
1048  delsub(v->nfa, lp, rp);
1049  EMPTYARC(lp, rp);
1050  return;
1051  }
1052 
1053  /* if not a messy case, avoid hard part */
1054  assert(!MESSY(top->flags));
1055  f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
1056  if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f)))
1057  {
1058  if (!(m == 1 && n == 1))
1059  repeat(v, lp, rp, m, n);
1060  if (atom != NULL)
1061  freesubre(v, atom);
1062  top->flags = f;
1063  return;
1064  }
1065 
1066  /*
1067  * hard part: something messy
1068  *
1069  * That is, capturing parens, back reference, short/long clash, or an atom
1070  * with substructure containing one of those.
1071  */
1072 
1073  /* now we'll need a subre for the contents even if they're boring */
1074  if (atom == NULL)
1075  {
1076  atom = subre(v, '=', 0, lp, rp);
1077  NOERR();
1078  }
1079 
1080  /*----------
1081  * Prepare a general-purpose state skeleton.
1082  *
1083  * In the no-backrefs case, we want this:
1084  *
1085  * [lp] ---> [s] ---prefix---> [begin] ---atom---> [end] ---rest---> [rp]
1086  *
1087  * where prefix is some repetitions of atom. In the general case we need
1088  *
1089  * [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp]
1090  *
1091  * where the iterator wraps around [begin] ---atom---> [end]
1092  *
1093  * We make the s state here for both cases; s2 is made below if needed
1094  *----------
1095  */
1096  s = newstate(v->nfa); /* first, new endpoints for the atom */
1097  s2 = newstate(v->nfa);
1098  NOERR();
1099  moveouts(v->nfa, lp, s);
1100  moveins(v->nfa, rp, s2);
1101  NOERR();
1102  atom->begin = s;
1103  atom->end = s2;
1104  s = newstate(v->nfa); /* set up starting state */
1105  NOERR();
1106  EMPTYARC(lp, s);
1107  NOERR();
1108 
1109  /* break remaining subRE into x{...} and what follows */
1110  t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
1111  NOERR();
1112  t->left = atom;
1113  atomp = &t->left;
1114 
1115  /* here we should recurse... but we must postpone that to the end */
1116 
1117  /* split top into prefix and remaining */
1118  assert(top->op == '=' && top->left == NULL && top->right == NULL);
1119  top->left = subre(v, '=', top->flags, top->begin, lp);
1120  NOERR();
1121  top->op = '.';
1122  top->right = t;
1123 
1124  /* if it's a backref, now is the time to replicate the subNFA */
1125  if (atomtype == BACKREF)
1126  {
1127  assert(atom->begin->nouts == 1); /* just the EMPTY */
1128  delsub(v->nfa, atom->begin, atom->end);
1129  assert(v->subs[subno] != NULL);
1130 
1131  /*
1132  * And here's why the recursion got postponed: it must wait until the
1133  * skeleton is filled in, because it may hit a backref that wants to
1134  * copy the filled-in skeleton.
1135  */
1136  dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
1137  atom->begin, atom->end);
1138  NOERR();
1139  }
1140 
1141  /*
1142  * It's quantifier time. If the atom is just a backref, we'll let it deal
1143  * with quantifiers internally.
1144  */
1145  if (atomtype == BACKREF)
1146  {
1147  /* special case: backrefs have internal quantifiers */
1148  EMPTYARC(s, atom->begin); /* empty prefix */
1149  /* just stuff everything into atom */
1150  repeat(v, atom->begin, atom->end, m, n);
1151  atom->min = (short) m;
1152  atom->max = (short) n;
1153  atom->flags |= COMBINE(qprefer, atom->flags);
1154  /* rest of branch can be strung starting from atom->end */
1155  s2 = atom->end;
1156  }
1157  else if (m == 1 && n == 1 &&
1158  (qprefer == 0 ||
1159  (atom->flags & (LONGER | SHORTER | MIXED)) == 0 ||
1160  qprefer == (atom->flags & (LONGER | SHORTER | MIXED))))
1161  {
1162  /* no/vacuous quantifier: done */
1163  EMPTYARC(s, atom->begin); /* empty prefix */
1164  /* rest of branch can be strung starting from atom->end */
1165  s2 = atom->end;
1166  }
1167  else if (m > 0 && !(atom->flags & BACKR))
1168  {
1169  /*
1170  * If there's no backrefs involved, we can turn x{m,n} into
1171  * x{m-1,n-1}x, with capturing parens in only the second x. This is
1172  * valid because we only care about capturing matches from the final
1173  * iteration of the quantifier. It's a win because we can implement
1174  * the backref-free left side as a plain DFA node, since we don't
1175  * really care where its submatches are.
1176  */
1177  dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
1178  assert(m >= 1 && m != DUPINF && n >= 1);
1179  repeat(v, s, atom->begin, m - 1, (n == DUPINF) ? n : n - 1);
1180  f = COMBINE(qprefer, atom->flags);
1181  t = subre(v, '.', f, s, atom->end); /* prefix and atom */
1182  NOERR();
1183  t->left = subre(v, '=', PREF(f), s, atom->begin);
1184  NOERR();
1185  t->right = atom;
1186  *atomp = t;
1187  /* rest of branch can be strung starting from atom->end */
1188  s2 = atom->end;
1189  }
1190  else
1191  {
1192  /* general case: need an iteration node */
1193  s2 = newstate(v->nfa);
1194  NOERR();
1195  moveouts(v->nfa, atom->end, s2);
1196  NOERR();
1197  dupnfa(v->nfa, atom->begin, atom->end, s, s2);
1198  repeat(v, s, s2, m, n);
1199  f = COMBINE(qprefer, atom->flags);
1200  t = subre(v, '*', f, s, s2);
1201  NOERR();
1202  t->min = (short) m;
1203  t->max = (short) n;
1204  t->left = atom;
1205  *atomp = t;
1206  /* rest of branch is to be strung from iteration's end state */
1207  }
1208 
1209  /* and finally, look after that postponed recursion */
1210  t = top->right;
1211  if (!(SEE('|') || SEE(stopper) || SEE(EOS)))
1212  t->right = parsebranch(v, stopper, type, s2, rp, 1);
1213  else
1214  {
1215  EMPTYARC(s2, rp);
1216  t->right = subre(v, '=', 0, s2, rp);
1217  }
1218  NOERR();
1219  assert(SEE('|') || SEE(stopper) || SEE(EOS));
1220  t->flags |= COMBINE(t->flags, t->right->flags);
1221  top->flags |= COMBINE(top->flags, t->flags);
1222 }
1223 
1224 /*
1225  * nonword - generate arcs for non-word-character ahead or behind
1226  */
1227 static void
1228 nonword(struct vars *v,
1229  int dir, /* AHEAD or BEHIND */
1230  struct state *lp,
1231  struct state *rp)
1232 {
1233  int anchor = (dir == AHEAD) ? '$' : '^';
1234 
1235  assert(dir == AHEAD || dir == BEHIND);
1236  newarc(v->nfa, anchor, 1, lp, rp);
1237  newarc(v->nfa, anchor, 0, lp, rp);
1238  colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
1239  /* (no need for special attention to \n) */
1240 }
1241 
1242 /*
1243  * word - generate arcs for word character ahead or behind
1244  */
1245 static void
1246 word(struct vars *v,
1247  int dir, /* AHEAD or BEHIND */
1248  struct state *lp,
1249  struct state *rp)
1250 {
1251  assert(dir == AHEAD || dir == BEHIND);
1252  cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
1253  /* (no need for special attention to \n) */
1254 }
1255 
1256 /*
1257  * scannum - scan a number
1258  */
1259 static int /* value, <= DUPMAX */
1260 scannum(struct vars *v)
1261 {
1262  int n = 0;
1263 
1264  while (SEE(DIGIT) && n < DUPMAX)
1265  {
1266  n = n * 10 + v->nextvalue;
1267  NEXT();
1268  }
1269  if (SEE(DIGIT) || n > DUPMAX)
1270  {
1271  ERR(REG_BADBR);
1272  return 0;
1273  }
1274  return n;
1275 }
1276 
1277 /*
1278  * repeat - replicate subNFA for quantifiers
1279  *
1280  * The sub-NFA strung from lp to rp is modified to represent m to n
1281  * repetitions of its initial contents.
1282  *
1283  * The duplication sequences used here are chosen carefully so that any
1284  * pointers starting out pointing into the subexpression end up pointing into
1285  * the last occurrence. (Note that it may not be strung between the same
1286  * left and right end states, however!) This used to be important for the
1287  * subRE tree, although the important bits are now handled by the in-line
1288  * code in parse(), and when this is called, it doesn't matter any more.
1289  */
1290 static void
1291 repeat(struct vars *v,
1292  struct state *lp,
1293  struct state *rp,
1294  int m,
1295  int n)
1296 {
1297 #define SOME 2
1298 #define INF 3
1299 #define PAIR(x, y) ((x)*4 + (y))
1300 #define REDUCE(x) ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) )
1301  const int rm = REDUCE(m);
1302  const int rn = REDUCE(n);
1303  struct state *s;
1304  struct state *s2;
1305 
1306  switch (PAIR(rm, rn))
1307  {
1308  case PAIR(0, 0): /* empty string */
1309  delsub(v->nfa, lp, rp);
1310  EMPTYARC(lp, rp);
1311  break;
1312  case PAIR(0, 1): /* do as x| */
1313  EMPTYARC(lp, rp);
1314  break;
1315  case PAIR(0, SOME): /* do as x{1,n}| */
1316  repeat(v, lp, rp, 1, n);
1317  NOERR();
1318  EMPTYARC(lp, rp);
1319  break;
1320  case PAIR(0, INF): /* loop x around */
1321  s = newstate(v->nfa);
1322  NOERR();
1323  moveouts(v->nfa, lp, s);
1324  moveins(v->nfa, rp, s);
1325  EMPTYARC(lp, s);
1326  EMPTYARC(s, rp);
1327  break;
1328  case PAIR(1, 1): /* no action required */
1329  break;
1330  case PAIR(1, SOME): /* do as x{0,n-1}x = (x{1,n-1}|)x */
1331  s = newstate(v->nfa);
1332  NOERR();
1333  moveouts(v->nfa, lp, s);
1334  dupnfa(v->nfa, s, rp, lp, s);
1335  NOERR();
1336  repeat(v, lp, s, 1, n - 1);
1337  NOERR();
1338  EMPTYARC(lp, s);
1339  break;
1340  case PAIR(1, INF): /* add loopback arc */
1341  s = newstate(v->nfa);
1342  s2 = newstate(v->nfa);
1343  NOERR();
1344  moveouts(v->nfa, lp, s);
1345  moveins(v->nfa, rp, s2);
1346  EMPTYARC(lp, s);
1347  EMPTYARC(s2, rp);
1348  EMPTYARC(s2, s);
1349  break;
1350  case PAIR(SOME, SOME): /* do as x{m-1,n-1}x */
1351  s = newstate(v->nfa);
1352  NOERR();
1353  moveouts(v->nfa, lp, s);
1354  dupnfa(v->nfa, s, rp, lp, s);
1355  NOERR();
1356  repeat(v, lp, s, m - 1, n - 1);
1357  break;
1358  case PAIR(SOME, INF): /* do as x{m-1,}x */
1359  s = newstate(v->nfa);
1360  NOERR();
1361  moveouts(v->nfa, lp, s);
1362  dupnfa(v->nfa, s, rp, lp, s);
1363  NOERR();
1364  repeat(v, lp, s, m - 1, n);
1365  break;
1366  default:
1367  ERR(REG_ASSERT);
1368  break;
1369  }
1370 }
1371 
1372 /*
1373  * bracket - handle non-complemented bracket expression
1374  * Also called from cbracket for complemented bracket expressions.
1375  */
1376 static void
1377 bracket(struct vars *v,
1378  struct state *lp,
1379  struct state *rp)
1380 {
1381  assert(SEE('['));
1382  NEXT();
1383  while (!SEE(']') && !SEE(EOS))
1384  brackpart(v, lp, rp);
1385  assert(SEE(']') || ISERR());
1386  okcolors(v->nfa, v->cm);
1387 }
1388 
1389 /*
1390  * cbracket - handle complemented bracket expression
1391  * We do it by calling bracket() with dummy endpoints, and then complementing
1392  * the result. The alternative would be to invoke rainbow(), and then delete
1393  * arcs as the b.e. is seen... but that gets messy.
1394  */
1395 static void
1396 cbracket(struct vars *v,
1397  struct state *lp,
1398  struct state *rp)
1399 {
1400  struct state *left = newstate(v->nfa);
1401  struct state *right = newstate(v->nfa);
1402 
1403  NOERR();
1404  bracket(v, left, right);
1405  if (v->cflags & REG_NLSTOP)
1406  newarc(v->nfa, PLAIN, v->nlcolor, left, right);
1407  NOERR();
1408 
1409  assert(lp->nouts == 0); /* all outarcs will be ours */
1410 
1411  /*
1412  * Easy part of complementing, and all there is to do since the MCCE code
1413  * was removed.
1414  */
1415  colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
1416  NOERR();
1417  dropstate(v->nfa, left);
1418  assert(right->nins == 0);
1419  freestate(v->nfa, right);
1420 }
1421 
1422 /*
1423  * brackpart - handle one item (or range) within a bracket expression
1424  */
1425 static void
1426 brackpart(struct vars *v,
1427  struct state *lp,
1428  struct state *rp)
1429 {
1430  chr startc;
1431  chr endc;
1432  struct cvec *cv;
1433  const chr *startp;
1434  const chr *endp;
1435  chr c[1];
1436 
1437  /* parse something, get rid of special cases, take shortcuts */
1438  switch (v->nexttype)
1439  {
1440  case RANGE: /* a-b-c or other botch */
1441  ERR(REG_ERANGE);
1442  return;
1443  break;
1444  case PLAIN:
1445  c[0] = v->nextvalue;
1446  NEXT();
1447  /* shortcut for ordinary chr (not range) */
1448  if (!SEE(RANGE))
1449  {
1450  onechr(v, c[0], lp, rp);
1451  return;
1452  }
1453  startc = element(v, c, c + 1);
1454  NOERR();
1455  break;
1456  case COLLEL:
1457  startp = v->now;
1458  endp = scanplain(v);
1459  INSIST(startp < endp, REG_ECOLLATE);
1460  NOERR();
1461  startc = element(v, startp, endp);
1462  NOERR();
1463  break;
1464  case ECLASS:
1465  startp = v->now;
1466  endp = scanplain(v);
1467  INSIST(startp < endp, REG_ECOLLATE);
1468  NOERR();
1469  startc = element(v, startp, endp);
1470  NOERR();
1471  cv = eclass(v, startc, (v->cflags & REG_ICASE));
1472  NOERR();
1473  subcolorcvec(v, cv, lp, rp);
1474  return;
1475  break;
1476  case CCLASS:
1477  startp = v->now;
1478  endp = scanplain(v);
1479  INSIST(startp < endp, REG_ECTYPE);
1480  NOERR();
1481  cv = cclass(v, startp, endp, (v->cflags & REG_ICASE));
1482  NOERR();
1483  subcolorcvec(v, cv, lp, rp);
1484  return;
1485  break;
1486  default:
1487  ERR(REG_ASSERT);
1488  return;
1489  break;
1490  }
1491 
1492  if (SEE(RANGE))
1493  {
1494  NEXT();
1495  switch (v->nexttype)
1496  {
1497  case PLAIN:
1498  case RANGE:
1499  c[0] = v->nextvalue;
1500  NEXT();
1501  endc = element(v, c, c + 1);
1502  NOERR();
1503  break;
1504  case COLLEL:
1505  startp = v->now;
1506  endp = scanplain(v);
1507  INSIST(startp < endp, REG_ECOLLATE);
1508  NOERR();
1509  endc = element(v, startp, endp);
1510  NOERR();
1511  break;
1512  default:
1513  ERR(REG_ERANGE);
1514  return;
1515  break;
1516  }
1517  }
1518  else
1519  endc = startc;
1520 
1521  /*
1522  * Ranges are unportable. Actually, standard C does guarantee that digits
1523  * are contiguous, but making that an exception is just too complicated.
1524  */
1525  if (startc != endc)
1526  NOTE(REG_UUNPORT);
1527  cv = range(v, startc, endc, (v->cflags & REG_ICASE));
1528  NOERR();
1529  subcolorcvec(v, cv, lp, rp);
1530 }
1531 
1532 /*
1533  * scanplain - scan PLAIN contents of [. etc.
1534  *
1535  * Certain bits of trickery in lex.c know that this code does not try
1536  * to look past the final bracket of the [. etc.
1537  */
1538 static const chr * /* just after end of sequence */
1539 scanplain(struct vars *v)
1540 {
1541  const chr *endp;
1542 
1543  assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
1544  NEXT();
1545 
1546  endp = v->now;
1547  while (SEE(PLAIN))
1548  {
1549  endp = v->now;
1550  NEXT();
1551  }
1552 
1553  assert(SEE(END) || ISERR());
1554  NEXT();
1555 
1556  return endp;
1557 }
1558 
1559 /*
1560  * onechr - fill in arcs for a plain character, and possible case complements
1561  * This is mostly a shortcut for efficient handling of the common case.
1562  */
1563 static void
1564 onechr(struct vars *v,
1565  chr c,
1566  struct state *lp,
1567  struct state *rp)
1568 {
1569  if (!(v->cflags & REG_ICASE))
1570  {
1571  color lastsubcolor = COLORLESS;
1572 
1573  subcoloronechr(v, c, lp, rp, &lastsubcolor);
1574  return;
1575  }
1576 
1577  /* rats, need general case anyway... */
1578  subcolorcvec(v, allcases(v, c), lp, rp);
1579 }
1580 
1581 /*
1582  * wordchrs - set up word-chr list for word-boundary stuff, if needed
1583  *
1584  * The list is kept as a bunch of arcs between two dummy states; it's
1585  * disposed of by the unreachable-states sweep in NFA optimization.
1586  * Does NEXT(). Must not be called from any unusual lexical context.
1587  * This should be reconciled with the \w etc. handling in lex.c, and
1588  * should be cleaned up to reduce dependencies on input scanning.
1589  */
1590 static void
1591 wordchrs(struct vars *v)
1592 {
1593  struct state *left;
1594  struct state *right;
1595 
1596  if (v->wordchrs != NULL)
1597  {
1598  NEXT(); /* for consistency */
1599  return;
1600  }
1601 
1602  left = newstate(v->nfa);
1603  right = newstate(v->nfa);
1604  NOERR();
1605  /* fine point: implemented with [::], and lexer will set REG_ULOCALE */
1606  lexword(v);
1607  NEXT();
1608  assert(v->savenow != NULL && SEE('['));
1609  bracket(v, left, right);
1610  assert((v->savenow != NULL && SEE(']')) || ISERR());
1611  NEXT();
1612  NOERR();
1613  v->wordchrs = left;
1614 }
1615 
1616 /*
1617  * processlacon - generate the NFA representation of a LACON
1618  *
1619  * In the general case this is just newlacon() + newarc(), but some cases
1620  * can be optimized.
1621  */
1622 static void
1623 processlacon(struct vars *v,
1624  struct state *begin, /* start of parsed LACON sub-re */
1625  struct state *end, /* end of parsed LACON sub-re */
1626  int latype,
1627  struct state *lp, /* left state to hang it on */
1628  struct state *rp) /* right state to hang it on */
1629 {
1630  struct state *s1;
1631  int n;
1632 
1633  /*
1634  * Check for lookaround RE consisting of a single plain color arc (or set
1635  * of arcs); this would typically be a simple chr or a bracket expression.
1636  */
1637  s1 = single_color_transition(begin, end);
1638  switch (latype)
1639  {
1640  case LATYPE_AHEAD_POS:
1641  /* If lookahead RE is just colorset C, convert to AHEAD(C) */
1642  if (s1 != NULL)
1643  {
1644  cloneouts(v->nfa, s1, lp, rp, AHEAD);
1645  return;
1646  }
1647  break;
1648  case LATYPE_AHEAD_NEG:
1649  /* If lookahead RE is just colorset C, convert to AHEAD(^C)|$ */
1650  if (s1 != NULL)
1651  {
1652  colorcomplement(v->nfa, v->cm, AHEAD, s1, lp, rp);
1653  newarc(v->nfa, '$', 1, lp, rp);
1654  newarc(v->nfa, '$', 0, lp, rp);
1655  return;
1656  }
1657  break;
1658  case LATYPE_BEHIND_POS:
1659  /* If lookbehind RE is just colorset C, convert to BEHIND(C) */
1660  if (s1 != NULL)
1661  {
1662  cloneouts(v->nfa, s1, lp, rp, BEHIND);
1663  return;
1664  }
1665  break;
1666  case LATYPE_BEHIND_NEG:
1667  /* If lookbehind RE is just colorset C, convert to BEHIND(^C)|^ */
1668  if (s1 != NULL)
1669  {
1670  colorcomplement(v->nfa, v->cm, BEHIND, s1, lp, rp);
1671  newarc(v->nfa, '^', 1, lp, rp);
1672  newarc(v->nfa, '^', 0, lp, rp);
1673  return;
1674  }
1675  break;
1676  default:
1677  assert(NOTREACHED);
1678  }
1679 
1680  /* General case: we need a LACON subre and arc */
1681  n = newlacon(v, begin, end, latype);
1682  newarc(v->nfa, LACON, n, lp, rp);
1683 }
1684 
1685 /*
1686  * subre - allocate a subre
1687  */
1688 static struct subre *
1689 subre(struct vars *v,
1690  int op,
1691  int flags,
1692  struct state *begin,
1693  struct state *end)
1694 {
1695  struct subre *ret = v->treefree;
1696 
1697  /*
1698  * Checking for stack overflow here is sufficient to protect parse() and
1699  * its recursive subroutines.
1700  */
1701  if (STACK_TOO_DEEP(v->re))
1702  {
1703  ERR(REG_ETOOBIG);
1704  return NULL;
1705  }
1706 
1707  if (ret != NULL)
1708  v->treefree = ret->left;
1709  else
1710  {
1711  ret = (struct subre *) MALLOC(sizeof(struct subre));
1712  if (ret == NULL)
1713  {
1714  ERR(REG_ESPACE);
1715  return NULL;
1716  }
1717  ret->chain = v->treechain;
1718  v->treechain = ret;
1719  }
1720 
1721  assert(strchr("=b|.*(", op) != NULL);
1722 
1723  ret->op = op;
1724  ret->flags = flags;
1725  ret->id = 0; /* will be assigned later */
1726  ret->subno = 0;
1727  ret->min = ret->max = 1;
1728  ret->left = NULL;
1729  ret->right = NULL;
1730  ret->begin = begin;
1731  ret->end = end;
1732  ZAPCNFA(ret->cnfa);
1733 
1734  return ret;
1735 }
1736 
1737 /*
1738  * freesubre - free a subRE subtree
1739  */
1740 static void
1741 freesubre(struct vars *v, /* might be NULL */
1742  struct subre *sr)
1743 {
1744  if (sr == NULL)
1745  return;
1746 
1747  if (sr->left != NULL)
1748  freesubre(v, sr->left);
1749  if (sr->right != NULL)
1750  freesubre(v, sr->right);
1751 
1752  freesrnode(v, sr);
1753 }
1754 
1755 /*
1756  * freesrnode - free one node in a subRE subtree
1757  */
1758 static void
1759 freesrnode(struct vars *v, /* might be NULL */
1760  struct subre *sr)
1761 {
1762  if (sr == NULL)
1763  return;
1764 
1765  if (!NULLCNFA(sr->cnfa))
1766  freecnfa(&sr->cnfa);
1767  sr->flags = 0;
1768 
1769  if (v != NULL && v->treechain != NULL)
1770  {
1771  /* we're still parsing, maybe we can reuse the subre */
1772  sr->left = v->treefree;
1773  v->treefree = sr;
1774  }
1775  else
1776  FREE(sr);
1777 }
1778 
1779 /*
1780  * optst - optimize a subRE subtree
1781  */
1782 static void
1783 optst(struct vars *v,
1784  struct subre *t)
1785 {
1786  /*
1787  * DGP (2007-11-13): I assume it was the programmer's intent to eventually
1788  * come back and add code to optimize subRE trees, but the routine coded
1789  * just spends effort traversing the tree and doing nothing. We can do
1790  * nothing with less effort.
1791  */
1792  return;
1793 }
1794 
1795 /*
1796  * numst - number tree nodes (assigning "id" indexes)
1797  */
1798 static int /* next number */
1799 numst(struct subre *t,
1800  int start) /* starting point for subtree numbers */
1801 {
1802  int i;
1803 
1804  assert(t != NULL);
1805 
1806  i = start;
1807  t->id = (short) i++;
1808  if (t->left != NULL)
1809  i = numst(t->left, i);
1810  if (t->right != NULL)
1811  i = numst(t->right, i);
1812  return i;
1813 }
1814 
1815 /*
1816  * markst - mark tree nodes as INUSE
1817  *
1818  * Note: this is a great deal more subtle than it looks. During initial
1819  * parsing of a regex, all subres are linked into the treechain list;
1820  * discarded ones are also linked into the treefree list for possible reuse.
1821  * After we are done creating all subres required for a regex, we run markst()
1822  * then cleanst(), which results in discarding all subres not reachable from
1823  * v->tree. We then clear v->treechain, indicating that subres must be found
1824  * by descending from v->tree. This changes the behavior of freesubre(): it
1825  * will henceforth FREE() unwanted subres rather than sticking them into the
1826  * treefree list. (Doing that any earlier would result in dangling links in
1827  * the treechain list.) This all means that freev() will clean up correctly
1828  * if invoked before or after markst()+cleanst(); but it would not work if
1829  * called partway through this state conversion, so we mustn't error out
1830  * in or between these two functions.
1831  */
1832 static void
1833 markst(struct subre *t)
1834 {
1835  assert(t != NULL);
1836 
1837  t->flags |= INUSE;
1838  if (t->left != NULL)
1839  markst(t->left);
1840  if (t->right != NULL)
1841  markst(t->right);
1842 }
1843 
1844 /*
1845  * cleanst - free any tree nodes not marked INUSE
1846  */
1847 static void
1848 cleanst(struct vars *v)
1849 {
1850  struct subre *t;
1851  struct subre *next;
1852 
1853  for (t = v->treechain; t != NULL; t = next)
1854  {
1855  next = t->chain;
1856  if (!(t->flags & INUSE))
1857  FREE(t);
1858  }
1859  v->treechain = NULL;
1860  v->treefree = NULL; /* just on general principles */
1861 }
1862 
1863 /*
1864  * nfatree - turn a subRE subtree into a tree of compacted NFAs
1865  */
1866 static long /* optimize results from top node */
1867 nfatree(struct vars *v,
1868  struct subre *t,
1869  FILE *f) /* for debug output */
1870 {
1871  assert(t != NULL && t->begin != NULL);
1872 
1873  if (t->left != NULL)
1874  (DISCARD) nfatree(v, t->left, f);
1875  if (t->right != NULL)
1876  (DISCARD) nfatree(v, t->right, f);
1877 
1878  return nfanode(v, t, 0, f);
1879 }
1880 
1881 /*
1882  * nfanode - do one NFA for nfatree or lacons
1883  *
1884  * If converttosearch is true, apply makesearch() to the NFA.
1885  */
1886 static long /* optimize results */
1887 nfanode(struct vars *v,
1888  struct subre *t,
1889  int converttosearch,
1890  FILE *f) /* for debug output */
1891 {
1892  struct nfa *nfa;
1893  long ret = 0;
1894 
1895  assert(t->begin != NULL);
1896 
1897 #ifdef REG_DEBUG
1898  if (f != NULL)
1899  {
1900  char idbuf[50];
1901 
1902  fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
1903  stid(t, idbuf, sizeof(idbuf)));
1904  }
1905 #endif
1906  nfa = newnfa(v, v->cm, v->nfa);
1907  NOERRZ();
1908  dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
1909  if (!ISERR())
1910  specialcolors(nfa);
1911  if (!ISERR())
1912  ret = optimize(nfa, f);
1913  if (converttosearch && !ISERR())
1914  makesearch(v, nfa);
1915  if (!ISERR())
1916  compact(nfa, &t->cnfa);
1917 
1918  freenfa(nfa);
1919  return ret;
1920 }
1921 
1922 /*
1923  * newlacon - allocate a lookaround-constraint subRE
1924  */
1925 static int /* lacon number */
1926 newlacon(struct vars *v,
1927  struct state *begin,
1928  struct state *end,
1929  int latype)
1930 {
1931  int n;
1932  struct subre *newlacons;
1933  struct subre *sub;
1934 
1935  if (v->nlacons == 0)
1936  {
1937  n = 1; /* skip 0th */
1938  newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre));
1939  }
1940  else
1941  {
1942  n = v->nlacons;
1943  newlacons = (struct subre *) REALLOC(v->lacons,
1944  (n + 1) * sizeof(struct subre));
1945  }
1946  if (newlacons == NULL)
1947  {
1948  ERR(REG_ESPACE);
1949  return 0;
1950  }
1951  v->lacons = newlacons;
1952  v->nlacons = n + 1;
1953  sub = &v->lacons[n];
1954  sub->begin = begin;
1955  sub->end = end;
1956  sub->subno = latype;
1957  ZAPCNFA(sub->cnfa);
1958  return n;
1959 }
1960 
1961 /*
1962  * freelacons - free lookaround-constraint subRE vector
1963  */
1964 static void
1966  int n)
1967 {
1968  struct subre *sub;
1969  int i;
1970 
1971  assert(n > 0);
1972  for (sub = subs + 1, i = n - 1; i > 0; sub++, i--) /* no 0th */
1973  if (!NULLCNFA(sub->cnfa))
1974  freecnfa(&sub->cnfa);
1975  FREE(subs);
1976 }
1977 
1978 /*
1979  * rfree - free a whole RE (insides of regfree)
1980  */
1981 static void
1983 {
1984  struct guts *g;
1985 
1986  if (re == NULL || re->re_magic != REMAGIC)
1987  return;
1988 
1989  re->re_magic = 0; /* invalidate RE */
1990  g = (struct guts *) re->re_guts;
1991  re->re_guts = NULL;
1992  re->re_fns = NULL;
1993  if (g != NULL)
1994  {
1995  g->magic = 0;
1996  freecm(&g->cmap);
1997  if (g->tree != NULL)
1998  freesubre((struct vars *) NULL, g->tree);
1999  if (g->lacons != NULL)
2000  freelacons(g->lacons, g->nlacons);
2001  if (!NULLCNFA(g->search))
2002  freecnfa(&g->search);
2003  FREE(g);
2004  }
2005 }
2006 
2007 /*
2008  * rcancelrequested - check for external request to cancel regex operation
2009  *
2010  * Return nonzero to fail the operation with error code REG_CANCEL,
2011  * zero to keep going
2012  *
2013  * The current implementation is Postgres-specific. If we ever get around
2014  * to splitting the regex code out as a standalone library, there will need
2015  * to be some API to let applications define a callback function for this.
2016  */
2017 static int
2019 {
2021 }
2022 
2023 /*
2024  * rstacktoodeep - check for stack getting dangerously deep
2025  *
2026  * Return nonzero to fail the operation with error code REG_ETOOBIG,
2027  * zero to keep going
2028  *
2029  * The current implementation is Postgres-specific. If we ever get around
2030  * to splitting the regex code out as a standalone library, there will need
2031  * to be some API to let applications define a callback function for this.
2032  */
2033 static int
2035 {
2036  return stack_is_too_deep();
2037 }
2038 
2039 #ifdef REG_DEBUG
2040 
2041 /*
2042  * dump - dump an RE in human-readable form
2043  */
2044 static void
2045 dump(regex_t *re,
2046  FILE *f)
2047 {
2048  struct guts *g;
2049  int i;
2050 
2051  if (re->re_magic != REMAGIC)
2052  fprintf(f, "bad magic number (0x%x not 0x%x)\n", re->re_magic,
2053  REMAGIC);
2054  if (re->re_guts == NULL)
2055  {
2056  fprintf(f, "NULL guts!!!\n");
2057  return;
2058  }
2059  g = (struct guts *) re->re_guts;
2060  if (g->magic != GUTSMAGIC)
2061  fprintf(f, "bad guts magic number (0x%x not 0x%x)\n", g->magic,
2062  GUTSMAGIC);
2063 
2064  fprintf(f, "\n\n\n========= DUMP ==========\n");
2065  fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
2066  (int) re->re_nsub, re->re_info, re->re_csize, g->ntree);
2067 
2068  dumpcolors(&g->cmap, f);
2069  if (!NULLCNFA(g->search))
2070  {
2071  fprintf(f, "\nsearch:\n");
2072  dumpcnfa(&g->search, f);
2073  }
2074  for (i = 1; i < g->nlacons; i++)
2075  {
2076  struct subre *lasub = &g->lacons[i];
2077  const char *latype;
2078 
2079  switch (lasub->subno)
2080  {
2081  case LATYPE_AHEAD_POS:
2082  latype = "positive lookahead";
2083  break;
2084  case LATYPE_AHEAD_NEG:
2085  latype = "negative lookahead";
2086  break;
2087  case LATYPE_BEHIND_POS:
2088  latype = "positive lookbehind";
2089  break;
2090  case LATYPE_BEHIND_NEG:
2091  latype = "negative lookbehind";
2092  break;
2093  default:
2094  latype = "???";
2095  break;
2096  }
2097  fprintf(f, "\nla%d (%s):\n", i, latype);
2098  dumpcnfa(&lasub->cnfa, f);
2099  }
2100  fprintf(f, "\n");
2101  dumpst(g->tree, f, 0);
2102 }
2103 
2104 /*
2105  * dumpst - dump a subRE tree
2106  */
2107 static void
2108 dumpst(struct subre *t,
2109  FILE *f,
2110  int nfapresent) /* is the original NFA still around? */
2111 {
2112  if (t == NULL)
2113  fprintf(f, "null tree\n");
2114  else
2115  stdump(t, f, nfapresent);
2116  fflush(f);
2117 }
2118 
2119 /*
2120  * stdump - recursive guts of dumpst
2121  */
2122 static void
2123 stdump(struct subre *t,
2124  FILE *f,
2125  int nfapresent) /* is the original NFA still around? */
2126 {
2127  char idbuf[50];
2128 
2129  fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
2130  if (t->flags & LONGER)
2131  fprintf(f, " longest");
2132  if (t->flags & SHORTER)
2133  fprintf(f, " shortest");
2134  if (t->flags & MIXED)
2135  fprintf(f, " hasmixed");
2136  if (t->flags & CAP)
2137  fprintf(f, " hascapture");
2138  if (t->flags & BACKR)
2139  fprintf(f, " hasbackref");
2140  if (!(t->flags & INUSE))
2141  fprintf(f, " UNUSED");
2142  if (t->subno != 0)
2143  fprintf(f, " (#%d)", t->subno);
2144  if (t->min != 1 || t->max != 1)
2145  {
2146  fprintf(f, " {%d,", t->min);
2147  if (t->max != DUPINF)
2148  fprintf(f, "%d", t->max);
2149  fprintf(f, "}");
2150  }
2151  if (nfapresent)
2152  fprintf(f, " %ld-%ld", (long) t->begin->no, (long) t->end->no);
2153  if (t->left != NULL)
2154  fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
2155  if (t->right != NULL)
2156  fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
2157  if (!NULLCNFA(t->cnfa))
2158  {
2159  fprintf(f, "\n");
2160  dumpcnfa(&t->cnfa, f);
2161  }
2162  fprintf(f, "\n");
2163  if (t->left != NULL)
2164  stdump(t->left, f, nfapresent);
2165  if (t->right != NULL)
2166  stdump(t->right, f, nfapresent);
2167 }
2168 
2169 /*
2170  * stid - identify a subtree node for dumping
2171  */
2172 static const char * /* points to buf or constant string */
2173 stid(struct subre *t,
2174  char *buf,
2175  size_t bufsize)
2176 {
2177  /* big enough for hex int or decimal t->id? */
2178  if (bufsize < sizeof(void *) * 2 + 3 || bufsize < sizeof(t->id) * 3 + 1)
2179  return "unable";
2180  if (t->id != 0)
2181  sprintf(buf, "%d", t->id);
2182  else
2183  sprintf(buf, "%p", t);
2184  return buf;
2185 }
2186 #endif /* REG_DEBUG */
2187 
2188 
2189 #include "regc_lex.c"
2190 #include "regc_color.c"
2191 #include "regc_nfa.c"
2192 #include "regc_cvec.c"
2193 #include "regc_pg_locale.c"
2194 #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:1260
#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:1783
#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 *)
volatile sig_atomic_t QueryCancelPending
Definition: globals.c:31
static void freelacons(struct subre *, int)
Definition: regcomp.c:1965
static int numst(struct subre *, int)
Definition: regcomp.c:1799
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:1982
#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:2018
static void bracket(struct vars *, struct state *, struct state *)
Definition: regcomp.c:1377
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:1867
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:1228
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:530
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:1689
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:1564
static color subcolor(struct colormap *, chr)
static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *)
Definition: regcomp.c:776
static void wordchrs(struct vars *)
Definition: regcomp.c:1591
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 *)
#define fprintf
Definition: port.h:196
#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:559
int pg_regcomp(regex_t *re, const chr *string, size_t len, int flags, Oid collation)
Definition: regcomp.c:313
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)
#define sprintf
Definition: port.h:194
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:1759
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:68
static void markst(struct subre *)
Definition: regcomp.c:1833
static void fixconstraintloops(struct nfa *, FILE *)
static void freesubre(struct vars *, struct subre *)
Definition: regcomp.c:1741
#define REG_BADRPT
Definition: regex.h:150
static void processlacon(struct vars *, struct state *, struct state *, int, struct state *, struct state *)
Definition: regcomp.c:1623
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:73
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:1539
#define REG_ADVANCED
Definition: regex.h:103
#define SEE(t)
Definition: regcomp.c:259
static int findconstraintloop(struct nfa *, struct state *)
#define init()
#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:1887
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:1426
#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:727
#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:2034
static void createarc(struct nfa *, int, color, struct state *, struct state *)
#define EOS
Definition: regcomp.c:275
#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:1396
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
volatile sig_atomic_t ProcDiePending
Definition: globals.c:32
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:298
static void subcoloronerange(struct vars *, chr, chr, struct state *, struct state *, color *)
volatile sig_atomic_t InterruptPending
Definition: globals.c:30
#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:1291
static void word(struct vars *, int, struct state *, struct state *)
Definition: regcomp.c:1246
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
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:1848
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:493
#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:1926
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:648
bool stack_is_too_deep(void)
Definition: postgres.c:3276
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