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-rw-r--r--generic/regcomp.c2225
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diff --git a/generic/regcomp.c b/generic/regcomp.c
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+++ b/generic/regcomp.c
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+/*
+ * re_*comp and friends - compile REs
+ * This file #includes several others (see the bottom).
+ *
+ * Copyright (c) 1998, 1999 Henry Spencer. All rights reserved.
+ *
+ * Development of this software was funded, in part, by Cray Research Inc.,
+ * UUNET Communications Services Inc., Sun Microsystems Inc., and Scriptics
+ * Corporation, none of whom are responsible for the results. The author
+ * thanks all of them.
+ *
+ * Redistribution and use in source and binary forms -- with or without
+ * modification -- are permitted for any purpose, provided that
+ * redistributions in source form retain this entire copyright notice and
+ * indicate the origin and nature of any modifications.
+ *
+ * I'd appreciate being given credit for this package in the documentation of
+ * software which uses it, but that is not a requirement.
+ *
+ * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES,
+ * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY
+ * AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL
+ * HENRY SPENCER BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+ * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+ * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+ * OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+ * WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+ * OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+ * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+ *
+ */
+
+#include "regguts.h"
+
+/*
+ * forward declarations, up here so forward datatypes etc. are defined early
+ */
+/* =====^!^===== begin forwards =====^!^===== */
+/* automatically gathered by fwd; do not hand-edit */
+/* === regcomp.c === */
+int compile(regex_t *, const chr *, size_t, int);
+static void moresubs(struct vars *, int);
+static int freev(struct vars *, int);
+static void makesearch(struct vars *, struct nfa *);
+static struct subre *parse(struct vars *, int, int, struct state *, struct state *);
+static struct subre *parsebranch(struct vars *, int, int, struct state *, struct state *, int);
+static void parseqatom(struct vars *, int, int, struct state *, struct state *, struct subre *);
+static void nonword(struct vars *, int, struct state *, struct state *);
+static void word(struct vars *, int, struct state *, struct state *);
+static int scannum(struct vars *);
+static void repeat(struct vars *, struct state *, struct state *, int, int);
+static void bracket(struct vars *, struct state *, struct state *);
+static void cbracket(struct vars *, struct state *, struct state *);
+static void brackpart(struct vars *, struct state *, struct state *);
+static const chr *scanplain(struct vars *);
+static void onechr(struct vars *, pchr, struct state *, struct state *);
+static void dovec(struct vars *, struct cvec *, struct state *, struct state *);
+static void wordchrs(struct vars *);
+static struct subre *subre(struct vars *, int, int, struct state *, struct state *);
+static void freesubre(struct vars *, struct subre *);
+static void freesrnode(struct vars *, struct subre *);
+static void optst(struct vars *, struct subre *);
+static int numst(struct subre *, int);
+static void markst(struct subre *);
+static void cleanst(struct vars *);
+static long nfatree(struct vars *, struct subre *, FILE *);
+static long nfanode(struct vars *, struct subre *, FILE *);
+static int newlacon(struct vars *, struct state *, struct state *, int);
+static void freelacons(struct subre *, int);
+static void rfree(regex_t *);
+static void dump(regex_t *, FILE *);
+static void dumpst(struct subre *, FILE *, int);
+static void stdump(struct subre *, FILE *, int);
+static const char *stid(struct subre *, char *, size_t);
+/* === regc_lex.c === */
+static void lexstart(struct vars *);
+static void prefixes(struct vars *);
+static void lexnest(struct vars *, const chr *, const chr *);
+static void lexword(struct vars *);
+static int next(struct vars *);
+static int lexescape(struct vars *);
+static int lexdigits(struct vars *, int, int, int);
+static int brenext(struct vars *, pchr);
+static void skip(struct vars *);
+static chr newline(void);
+static chr chrnamed(struct vars *, const chr *, const chr *, pchr);
+/* === regc_color.c === */
+static void initcm(struct vars *, struct colormap *);
+static void freecm(struct colormap *);
+static void cmtreefree(struct colormap *, union tree *, int);
+static color setcolor(struct colormap *, pchr, pcolor);
+static color maxcolor(struct colormap *);
+static color newcolor(struct colormap *);
+static void freecolor(struct colormap *, pcolor);
+static color pseudocolor(struct colormap *);
+static color subcolor(struct colormap *, pchr c);
+static color newsub(struct colormap *, pcolor);
+static void subrange(struct vars *, pchr, pchr, struct state *, struct state *);
+static void subblock(struct vars *, pchr, struct state *, struct state *);
+static void okcolors(struct nfa *, struct colormap *);
+static void colorchain(struct colormap *, struct arc *);
+static void uncolorchain(struct colormap *, struct arc *);
+static void rainbow(struct nfa *, struct colormap *, int, pcolor, struct state *, struct state *);
+static void colorcomplement(struct nfa *, struct colormap *, int, struct state *, struct state *, struct state *);
+#ifdef REG_DEBUG
+static void dumpcolors(struct colormap *, FILE *);
+static void fillcheck(struct colormap *, union tree *, int, FILE *);
+static void dumpchr(pchr, FILE *);
+#endif
+/* === regc_nfa.c === */
+static struct nfa *newnfa(struct vars *, struct colormap *, struct nfa *);
+static void freenfa(struct nfa *);
+static struct state *newstate(struct nfa *);
+static struct state *newfstate(struct nfa *, int flag);
+static void dropstate(struct nfa *, struct state *);
+static void freestate(struct nfa *, struct state *);
+static void destroystate(struct nfa *, struct state *);
+static void newarc(struct nfa *, int, pcolor, struct state *, struct state *);
+static void createarc(struct nfa *, int, pcolor, struct state *, struct state *);
+static struct arc *allocarc(struct nfa *, struct state *);
+static void freearc(struct nfa *, struct arc *);
+static void changearctarget(struct arc *, struct state *);
+static int hasnonemptyout(struct state *);
+static struct arc *findarc(struct state *, int, pcolor);
+static void cparc(struct nfa *, struct arc *, struct state *, struct state *);
+static void sortins(struct nfa *, struct state *);
+static int sortins_cmp(const void *, const void *);
+static void sortouts(struct nfa *, struct state *);
+static int sortouts_cmp(const void *, const void *);
+static void moveins(struct nfa *, struct state *, struct state *);
+static void copyins(struct nfa *, struct state *, struct state *);
+static void mergeins(struct nfa *, struct state *, struct arc **, int);
+static void moveouts(struct nfa *, struct state *, struct state *);
+static void copyouts(struct nfa *, struct state *, struct state *);
+static void cloneouts(struct nfa *, struct state *, struct state *, struct state *, int);
+static void delsub(struct nfa *, struct state *, struct state *);
+static void deltraverse(struct nfa *, struct state *, struct state *);
+static void dupnfa(struct nfa *, struct state *, struct state *, struct state *, struct state *);
+static void duptraverse(struct nfa *, struct state *, struct state *, int);
+static void cleartraverse(struct nfa *, struct state *);
+static void specialcolors(struct nfa *);
+static long optimize(struct nfa *, FILE *);
+static void pullback(struct nfa *, FILE *);
+static int pull(struct nfa *, struct arc *, struct state **);
+static void pushfwd(struct nfa *, FILE *);
+static int push(struct nfa *, struct arc *, struct state **);
+#define INCOMPATIBLE 1 /* destroys arc */
+#define SATISFIED 2 /* constraint satisfied */
+#define COMPATIBLE 3 /* compatible but not satisfied yet */
+static int combine(struct arc *, struct arc *);
+static void fixempties(struct nfa *, FILE *);
+static struct state *emptyreachable(struct nfa *, struct state *,
+ struct state *, struct arc **);
+static int isconstraintarc(struct arc *);
+static int hasconstraintout(struct state *);
+static void fixconstraintloops(struct nfa *, FILE *);
+static int findconstraintloop(struct nfa *, struct state *);
+static void breakconstraintloop(struct nfa *, struct state *);
+static void clonesuccessorstates(struct nfa *, struct state *, struct state *,
+ struct state *, struct arc *, char *, char *, int);
+static void cleanup(struct nfa *);
+static void markreachable(struct nfa *, struct state *, struct state *, struct state *);
+static void markcanreach(struct nfa *, struct state *, struct state *, struct state *);
+static long analyze(struct nfa *);
+static void compact(struct nfa *, struct cnfa *);
+static void carcsort(struct carc *, size_t);
+static int carc_cmp(const void *, const void *);
+static void freecnfa(struct cnfa *);
+static void dumpnfa(struct nfa *, FILE *);
+#ifdef REG_DEBUG
+static void dumpstate(struct state *, FILE *);
+static void dumparcs(struct state *, FILE *);
+static void dumparc(struct arc *, struct state *, FILE *);
+#endif
+static void dumpcnfa(struct cnfa *, FILE *);
+#ifdef REG_DEBUG
+static void dumpcstate(int, struct cnfa *, FILE *);
+#endif
+/* === regc_cvec.c === */
+static struct cvec *clearcvec(struct cvec *);
+static void addchr(struct cvec *, pchr);
+static void addrange(struct cvec *, pchr, pchr);
+static struct cvec *newcvec(int, int);
+static struct cvec *getcvec(struct vars *, int, int);
+static void freecvec(struct cvec *);
+/* === regc_locale.c === */
+static celt element(struct vars *, const chr *, const chr *);
+static struct cvec *range(struct vars *, celt, celt, int);
+static int before(celt, celt);
+static struct cvec *eclass(struct vars *, celt, int);
+static struct cvec *cclass(struct vars *, const chr *, const chr *, int);
+static struct cvec *allcases(struct vars *, pchr);
+static int cmp(const chr *, const chr *, size_t);
+static int casecmp(const chr *, const chr *, size_t);
+/* automatically gathered by fwd; do not hand-edit */
+/* =====^!^===== end forwards =====^!^===== */
+
+/* internal variables, bundled for easy passing around */
+struct vars {
+ regex_t *re;
+ const chr *now; /* scan pointer into string */
+ const chr *stop; /* end of string */
+ const chr *savenow; /* saved now and stop for "subroutine call" */
+ const chr *savestop;
+ int err; /* error code (0 if none) */
+ int cflags; /* copy of compile flags */
+ int lasttype; /* type of previous token */
+ int nexttype; /* type of next token */
+ chr nextvalue; /* value (if any) of next token */
+ int lexcon; /* lexical context type (see lex.c) */
+ int nsubexp; /* subexpression count */
+ struct subre **subs; /* subRE pointer vector */
+ size_t nsubs; /* length of vector */
+ struct subre *sub10[10]; /* initial vector, enough for most */
+ struct nfa *nfa; /* the NFA */
+ struct colormap *cm; /* character color map */
+ color nlcolor; /* color of newline */
+ struct state *wordchrs; /* state in nfa holding word-char outarcs */
+ struct subre *tree; /* subexpression tree */
+ struct subre *treechain; /* all tree nodes allocated */
+ struct subre *treefree; /* any free tree nodes */
+ int ntree; /* number of tree nodes, plus one */
+ struct cvec *cv; /* interface cvec */
+ struct cvec *cv2; /* utility cvec */
+ struct subre *lacons; /* lookahead-constraint vector */
+ int nlacons; /* size of lacons */
+ size_t spaceused; /* approx. space used for compilation */
+};
+
+/* parsing macros; most know that `v' is the struct vars pointer */
+#define NEXT() (next(v)) /* advance by one token */
+#define SEE(t) (v->nexttype == (t)) /* is next token this? */
+#define EAT(t) (SEE(t) && next(v)) /* if next is this, swallow it */
+#define VISERR(vv) ((vv)->err != 0)/* have we seen an error yet? */
+#define ISERR() VISERR(v)
+#define VERR(vv,e) ((vv)->nexttype = EOS, \
+ (vv)->err = ((vv)->err ? (vv)->err : (e)))
+#define ERR(e) VERR(v, e) /* record an error */
+#define NOERR() {if (ISERR()) return;} /* if error seen, return */
+#define NOERRN() {if (ISERR()) return NULL;} /* NOERR with retval */
+#define NOERRZ() {if (ISERR()) return 0;} /* NOERR with retval */
+#define INSIST(c, e) do { if (!(c)) ERR(e); } while (0) /* error if c false */
+#define NOTE(b) (v->re->re_info |= (b)) /* note visible condition */
+#define EMPTYARC(x, y) newarc(v->nfa, EMPTY, 0, x, y)
+
+/* token type codes, some also used as NFA arc types */
+#define EMPTY 'n' /* no token present */
+#define EOS 'e' /* end of string */
+#define PLAIN 'p' /* ordinary character */
+#define DIGIT 'd' /* digit (in bound) */
+#define BACKREF 'b' /* back reference */
+#define COLLEL 'I' /* start of [. */
+#define ECLASS 'E' /* start of [= */
+#define CCLASS 'C' /* start of [: */
+#define END 'X' /* end of [. [= [: */
+#define RANGE 'R' /* - within [] which might be range delim. */
+#define LACON 'L' /* lookahead constraint subRE */
+#define AHEAD 'a' /* color-lookahead arc */
+#define BEHIND 'r' /* color-lookbehind arc */
+#define WBDRY 'w' /* word boundary constraint */
+#define NWBDRY 'W' /* non-word-boundary constraint */
+#define SBEGIN 'A' /* beginning of string (even if not BOL) */
+#define SEND 'Z' /* end of string (even if not EOL) */
+#define PREFER 'P' /* length preference */
+
+/* is an arc colored, and hence on a color chain? */
+#define COLORED(a) \
+ ((a)->type == PLAIN || (a)->type == AHEAD || (a)->type == BEHIND)
+
+/* static function list */
+static const struct fns functions = {
+ rfree, /* regfree insides */
+};
+
+/*
+ - compile - compile regular expression
+ * Note: on failure, no resources remain allocated, so regfree()
+ * need not be applied to re.
+ ^ int compile(regex_t *, const chr *, size_t, int);
+ */
+int
+compile(
+ regex_t *re,
+ const chr *string,
+ size_t len,
+ int flags)
+{
+ AllocVars(v);
+ struct guts *g;
+ int i;
+ size_t j;
+ FILE *debug = (flags&REG_PROGRESS) ? stdout : NULL;
+#define CNOERR() { if (ISERR()) return freev(v, v->err); }
+
+ /*
+ * Sanity checks.
+ */
+
+ if (re == NULL || string == NULL) {
+ FreeVars(v);
+ return REG_INVARG;
+ }
+ if ((flags&REG_QUOTE) && (flags&(REG_ADVANCED|REG_EXPANDED|REG_NEWLINE))) {
+ FreeVars(v);
+ return REG_INVARG;
+ }
+ if (!(flags&REG_EXTENDED) && (flags&REG_ADVF)) {
+ FreeVars(v);
+ return REG_INVARG;
+ }
+
+ /*
+ * Initial setup (after which freev() is callable).
+ */
+
+ v->re = re;
+ v->now = string;
+ v->stop = v->now + len;
+ v->savenow = v->savestop = NULL;
+ v->err = 0;
+ v->cflags = flags;
+ v->nsubexp = 0;
+ v->subs = v->sub10;
+ v->nsubs = 10;
+ for (j = 0; j < v->nsubs; j++) {
+ v->subs[j] = NULL;
+ }
+ v->nfa = NULL;
+ v->cm = NULL;
+ v->nlcolor = COLORLESS;
+ v->wordchrs = NULL;
+ v->tree = NULL;
+ v->treechain = NULL;
+ v->treefree = NULL;
+ v->cv = NULL;
+ v->cv2 = NULL;
+ v->lacons = NULL;
+ v->nlacons = 0;
+ v->spaceused = 0;
+ re->re_magic = REMAGIC;
+ re->re_info = 0; /* bits get set during parse */
+ re->re_csize = sizeof(chr);
+ re->re_guts = NULL;
+ re->re_fns = (void*)(&functions);
+
+ /*
+ * More complex setup, malloced things.
+ */
+
+ re->re_guts = (void*)(MALLOC(sizeof(struct guts)));
+ if (re->re_guts == NULL) {
+ return freev(v, REG_ESPACE);
+ }
+ g = (struct guts *) re->re_guts;
+ g->tree = NULL;
+ initcm(v, &g->cmap);
+ v->cm = &g->cmap;
+ g->lacons = NULL;
+ g->nlacons = 0;
+ ZAPCNFA(g->search);
+ v->nfa = newnfa(v, v->cm, NULL);
+ CNOERR();
+ v->cv = newcvec(100, 20);
+ if (v->cv == NULL) {
+ return freev(v, REG_ESPACE);
+ }
+
+ /*
+ * Parsing.
+ */
+
+ lexstart(v); /* also handles prefixes */
+ if ((v->cflags&REG_NLSTOP) || (v->cflags&REG_NLANCH)) {
+ /*
+ * Assign newline a unique color.
+ */
+
+ v->nlcolor = subcolor(v->cm, newline());
+ okcolors(v->nfa, v->cm);
+ }
+ CNOERR();
+ v->tree = parse(v, EOS, PLAIN, v->nfa->init, v->nfa->final);
+ assert(SEE(EOS)); /* even if error; ISERR() => SEE(EOS) */
+ CNOERR();
+ assert(v->tree != NULL);
+
+ /*
+ * Finish setup of nfa and its subre tree.
+ */
+
+ specialcolors(v->nfa);
+ CNOERR();
+ if (debug != NULL) {
+ fprintf(debug, "\n\n\n========= RAW ==========\n");
+ dumpnfa(v->nfa, debug);
+ dumpst(v->tree, debug, 1);
+ }
+ optst(v, v->tree);
+ v->ntree = numst(v->tree, 1);
+ markst(v->tree);
+ cleanst(v);
+ if (debug != NULL) {
+ fprintf(debug, "\n\n\n========= TREE FIXED ==========\n");
+ dumpst(v->tree, debug, 1);
+ }
+
+ /*
+ * Build compacted NFAs for tree and lacons.
+ */
+
+ re->re_info |= nfatree(v, v->tree, debug);
+ CNOERR();
+ assert(v->nlacons == 0 || v->lacons != NULL);
+ for (i = 1; i < v->nlacons; i++) {
+ if (debug != NULL) {
+ fprintf(debug, "\n\n\n========= LA%d ==========\n", i);
+ }
+ nfanode(v, &v->lacons[i], debug);
+ }
+ CNOERR();
+ if (v->tree->flags&SHORTER) {
+ NOTE(REG_USHORTEST);
+ }
+
+ /*
+ * Build compacted NFAs for tree, lacons, fast search.
+ */
+
+ if (debug != NULL) {
+ fprintf(debug, "\n\n\n========= SEARCH ==========\n");
+ }
+
+ /*
+ * Can sacrifice main NFA now, so use it as work area.
+ */
+
+ (void) optimize(v->nfa, debug);
+ CNOERR();
+ makesearch(v, v->nfa);
+ CNOERR();
+ compact(v->nfa, &g->search);
+ CNOERR();
+
+ /*
+ * Looks okay, package it up.
+ */
+
+ re->re_nsub = v->nsubexp;
+ v->re = NULL; /* freev no longer frees re */
+ g->magic = GUTSMAGIC;
+ g->cflags = v->cflags;
+ g->info = re->re_info;
+ g->nsub = re->re_nsub;
+ g->tree = v->tree;
+ v->tree = NULL;
+ g->ntree = v->ntree;
+ g->compare = (v->cflags&REG_ICASE) ? casecmp : cmp;
+ g->lacons = v->lacons;
+ v->lacons = NULL;
+ g->nlacons = v->nlacons;
+
+ if (flags&REG_DUMP) {
+ dump(re, stdout);
+ }
+
+ assert(v->err == 0);
+ return freev(v, 0);
+}
+
+/*
+ - moresubs - enlarge subRE vector
+ ^ static void moresubs(struct vars *, int);
+ */
+static void
+moresubs(
+ struct vars *v,
+ int wanted) /* want enough room for this one */
+{
+ struct subre **p;
+ size_t n;
+
+ assert(wanted > 0 && (size_t)wanted >= v->nsubs);
+ n = (size_t)wanted * 3 / 2 + 1;
+ if (v->subs == v->sub10) {
+ p = (struct subre **) MALLOC(n * sizeof(struct subre *));
+ if (p != NULL) {
+ memcpy(p, v->subs, v->nsubs * sizeof(struct subre *));
+ }
+ } else {
+ p = (struct subre **) REALLOC(v->subs, n*sizeof(struct subre *));
+ }
+ if (p == NULL) {
+ ERR(REG_ESPACE);
+ return;
+ }
+
+ v->subs = p;
+ for (p = &v->subs[v->nsubs]; v->nsubs < n; p++, v->nsubs++) {
+ *p = NULL;
+ }
+ assert(v->nsubs == n);
+ assert((size_t)wanted < v->nsubs);
+}
+
+/*
+ - freev - free vars struct's substructures where necessary
+ * Optionally does error-number setting, and always returns error code (if
+ * any), to make error-handling code terser.
+ ^ static int freev(struct vars *, int);
+ */
+static int
+freev(
+ struct vars *v,
+ int err)
+{
+ register int ret;
+
+ if (v->re != NULL) {
+ rfree(v->re);
+ }
+ if (v->subs != v->sub10) {
+ FREE(v->subs);
+ }
+ if (v->nfa != NULL) {
+ freenfa(v->nfa);
+ }
+ if (v->tree != NULL) {
+ freesubre(v, v->tree);
+ }
+ if (v->treechain != NULL) {
+ cleanst(v);
+ }
+ if (v->cv != NULL) {
+ freecvec(v->cv);
+ }
+ if (v->cv2 != NULL) {
+ freecvec(v->cv2);
+ }
+ if (v->lacons != NULL) {
+ freelacons(v->lacons, v->nlacons);
+ }
+ ERR(err); /* nop if err==0 */
+
+ ret = v->err;
+ FreeVars(v);
+ return ret;
+}
+
+/*
+ - makesearch - turn an NFA into a search NFA (implicit prepend of .*?)
+ * NFA must have been optimize()d already.
+ ^ static void makesearch(struct vars *, struct nfa *);
+ */
+static void
+makesearch(
+ struct vars *v,
+ struct nfa *nfa)
+{
+ struct arc *a, *b;
+ struct state *pre = nfa->pre;
+ struct state *s, *s2, *slist;
+
+ /*
+ * No loops are needed if it's anchored.
+ */
+
+ for (a = pre->outs; a != NULL; a = a->outchain) {
+ assert(a->type == PLAIN);
+ if (a->co != nfa->bos[0] && a->co != nfa->bos[1]) {
+ break;
+ }
+ }
+ if (a != NULL) {
+ /*
+ * Add implicit .* in front.
+ */
+
+ rainbow(nfa, v->cm, PLAIN, COLORLESS, pre, pre);
+
+ /*
+ * And ^* and \A* too -- not always necessary, but harmless.
+ */
+
+ newarc(nfa, PLAIN, nfa->bos[0], pre, pre);
+ newarc(nfa, PLAIN, nfa->bos[1], pre, pre);
+ }
+
+ /*
+ * Now here's the subtle part. Because many REs have no lookback
+ * constraints, often knowing when you were in the pre state tells you
+ * little; it's the next state(s) that are informative. But some of them
+ * may have other inarcs, i.e. it may be possible to make actual progress
+ * and then return to one of them. We must de-optimize such cases,
+ * splitting each such state into progress and no-progress states.
+ */
+
+ /*
+ * First, make a list of the states.
+ */
+
+ slist = NULL;
+ for (a=pre->outs ; a!=NULL ; a=a->outchain) {
+ s = a->to;
+ for (b=s->ins ; b!=NULL ; b=b->inchain) {
+ if (b->from != pre) {
+ break;
+ }
+ }
+
+ /*
+ * We want to mark states as being in the list already by having non
+ * NULL tmp fields, but we can't just store the old slist value in tmp
+ * because that doesn't work for the first such state. Instead, the
+ * first list entry gets its own address in tmp.
+ */
+ if (b != NULL && s->tmp == NULL) {
+ s->tmp = (slist != NULL) ? slist : s;
+ slist = s;
+ }
+ }
+
+ /*
+ * Do the splits.
+ */
+
+ for (s=slist ; s!=NULL ; s=s2) {
+ s2 = newstate(nfa);
+ NOERR();
+ copyouts(nfa, s, s2);
+ NOERR();
+ for (a=s->ins ; a!=NULL ; a=b) {
+ b = a->inchain;
+
+ if (a->from != pre) {
+ cparc(nfa, a, a->from, s2);
+ freearc(nfa, a);
+ }
+ }
+ s2 = (s->tmp != s) ? s->tmp : NULL;
+ s->tmp = NULL; /* clean up while we're at it */
+ }
+}
+
+/*
+ - parse - parse an RE
+ * This is actually just the top level, which parses a bunch of branches tied
+ * together with '|'. They appear in the tree as the left children of a chain
+ * of '|' subres.
+ ^ static struct subre *parse(struct vars *, int, int, struct state *,
+ ^ struct state *);
+ */
+static struct subre *
+parse(
+ struct vars *v,
+ int stopper, /* EOS or ')' */
+ int type, /* LACON (lookahead subRE) or PLAIN */
+ struct state *init, /* initial state */
+ struct state *final) /* final state */
+{
+ struct state *left, *right; /* scaffolding for branch */
+ struct subre *branches; /* top level */
+ struct subre *branch; /* current branch */
+ struct subre *t; /* temporary */
+ int firstbranch; /* is this the first branch? */
+
+ assert(stopper == ')' || stopper == EOS);
+
+ branches = subre(v, '|', LONGER, init, final);
+ NOERRN();
+ branch = branches;
+ firstbranch = 1;
+ do { /* a branch */
+ if (!firstbranch) {
+ /*
+ * Need a place to hang the branch.
+ */
+
+ branch->right = subre(v, '|', LONGER, init, final);
+ NOERRN();
+ branch = branch->right;
+ }
+ firstbranch = 0;
+ left = newstate(v->nfa);
+ right = newstate(v->nfa);
+ NOERRN();
+ EMPTYARC(init, left);
+ EMPTYARC(right, final);
+ NOERRN();
+ branch->left = parsebranch(v, stopper, type, left, right, 0);
+ NOERRN();
+ branch->flags |= UP(branch->flags | branch->left->flags);
+ if ((branch->flags &~ branches->flags) != 0) { /* new flags */
+ for (t = branches; t != branch; t = t->right) {
+ t->flags |= branch->flags;
+ }
+ }
+ } while (EAT('|'));
+ assert(SEE(stopper) || SEE(EOS));
+
+ if (!SEE(stopper)) {
+ assert(stopper == ')' && SEE(EOS));
+ ERR(REG_EPAREN);
+ }
+
+ /*
+ * Optimize out simple cases.
+ */
+
+ if (branch == branches) { /* only one branch */
+ assert(branch->right == NULL);
+ t = branch->left;
+ branch->left = NULL;
+ freesubre(v, branches);
+ branches = t;
+ } else if (!MESSY(branches->flags)) { /* no interesting innards */
+ freesubre(v, branches->left);
+ branches->left = NULL;
+ freesubre(v, branches->right);
+ branches->right = NULL;
+ branches->op = '=';
+ }
+
+ return branches;
+}
+
+/*
+ - parsebranch - parse one branch of an RE
+ * This mostly manages concatenation, working closely with parseqatom().
+ * Concatenated things are bundled up as much as possible, with separate
+ * ',' nodes introduced only when necessary due to substructure.
+ ^ static struct subre *parsebranch(struct vars *, int, int, struct state *,
+ ^ struct state *, int);
+ */
+static struct subre *
+parsebranch(
+ struct vars *v,
+ int stopper, /* EOS or ')' */
+ int type, /* LACON (lookahead subRE) or PLAIN */
+ struct state *left, /* leftmost state */
+ struct state *right, /* rightmost state */
+ int partial) /* is this only part of a branch? */
+{
+ struct state *lp; /* left end of current construct */
+ int seencontent; /* is there anything in this branch yet? */
+ struct subre *t;
+
+ lp = left;
+ seencontent = 0;
+ t = subre(v, '=', 0, left, right); /* op '=' is tentative */
+ NOERRN();
+ while (!SEE('|') && !SEE(stopper) && !SEE(EOS)) {
+ if (seencontent) { /* implicit concat operator */
+ lp = newstate(v->nfa);
+ NOERRN();
+ moveins(v->nfa, right, lp);
+ }
+ seencontent = 1;
+
+ /* NB, recursion in parseqatom() may swallow rest of branch */
+ parseqatom(v, stopper, type, lp, right, t);
+ NOERRN();
+ }
+
+ if (!seencontent) { /* empty branch */
+ if (!partial) {
+ NOTE(REG_UUNSPEC);
+ }
+ assert(lp == left);
+ EMPTYARC(left, right);
+ }
+
+ return t;
+}
+
+/*
+ - parseqatom - parse one quantified atom or constraint of an RE
+ * The bookkeeping near the end cooperates very closely with parsebranch(); in
+ * particular, it contains a recursion that can involve parsing the rest of
+ * the branch, making this function's name somewhat inaccurate.
+ ^ static void parseqatom(struct vars *, int, int, struct state *,
+ ^ struct state *, struct subre *);
+ */
+static void
+parseqatom(
+ struct vars *v,
+ int stopper, /* EOS or ')' */
+ int type, /* LACON (lookahead subRE) or PLAIN */
+ struct state *lp, /* left state to hang it on */
+ struct state *rp, /* right state to hang it on */
+ struct subre *top) /* subtree top */
+{
+ struct state *s; /* temporaries for new states */
+ struct state *s2;
+#define ARCV(t, val) newarc(v->nfa, t, val, lp, rp)
+ int m, n;
+ struct subre *atom; /* atom's subtree */
+ struct subre *t;
+ int cap; /* capturing parens? */
+ int pos; /* positive lookahead? */
+ int subno; /* capturing-parens or backref number */
+ int atomtype;
+ int qprefer; /* quantifier short/long preference */
+ int f;
+ struct subre **atomp; /* where the pointer to atom is */
+
+ /*
+ * Initial bookkeeping.
+ */
+
+ atom = NULL;
+ assert(lp->nouts == 0); /* must string new code */
+ assert(rp->nins == 0); /* between lp and rp */
+ subno = 0; /* just to shut lint up */
+
+ /*
+ * An atom or constraint...
+ */
+
+ atomtype = v->nexttype;
+ switch (atomtype) {
+ /* first, constraints, which end by returning */
+ case '^':
+ ARCV('^', 1);
+ if (v->cflags&REG_NLANCH) {
+ ARCV(BEHIND, v->nlcolor);
+ }
+ NEXT();
+ return;
+ case '$':
+ ARCV('$', 1);
+ if (v->cflags&REG_NLANCH) {
+ ARCV(AHEAD, v->nlcolor);
+ }
+ NEXT();
+ return;
+ case SBEGIN:
+ ARCV('^', 1); /* BOL */
+ ARCV('^', 0); /* or BOS */
+ NEXT();
+ return;
+ case SEND:
+ ARCV('$', 1); /* EOL */
+ ARCV('$', 0); /* or EOS */
+ NEXT();
+ return;
+ case '<':
+ wordchrs(v); /* does NEXT() */
+ s = newstate(v->nfa);
+ NOERR();
+ nonword(v, BEHIND, lp, s);
+ word(v, AHEAD, s, rp);
+ return;
+ case '>':
+ wordchrs(v); /* does NEXT() */
+ s = newstate(v->nfa);
+ NOERR();
+ word(v, BEHIND, lp, s);
+ nonword(v, AHEAD, s, rp);
+ return;
+ case WBDRY:
+ wordchrs(v); /* does NEXT() */
+ s = newstate(v->nfa);
+ NOERR();
+ nonword(v, BEHIND, lp, s);
+ word(v, AHEAD, s, rp);
+ s = newstate(v->nfa);
+ NOERR();
+ word(v, BEHIND, lp, s);
+ nonword(v, AHEAD, s, rp);
+ return;
+ case NWBDRY:
+ wordchrs(v); /* does NEXT() */
+ s = newstate(v->nfa);
+ NOERR();
+ word(v, BEHIND, lp, s);
+ word(v, AHEAD, s, rp);
+ s = newstate(v->nfa);
+ NOERR();
+ nonword(v, BEHIND, lp, s);
+ nonword(v, AHEAD, s, rp);
+ return;
+ case LACON: /* lookahead constraint */
+ pos = v->nextvalue;
+ NEXT();
+ s = newstate(v->nfa);
+ s2 = newstate(v->nfa);
+ NOERR();
+ t = parse(v, ')', LACON, s, s2);
+ freesubre(v, t); /* internal structure irrelevant */
+ assert(SEE(')') || ISERR());
+ NEXT();
+ n = newlacon(v, s, s2, pos);
+ NOERR();
+ ARCV(LACON, n);
+ return;
+
+ /*
+ * Then errors, to get them out of the way.
+ */
+
+ case '*':
+ case '+':
+ case '?':
+ case '{':
+ ERR(REG_BADRPT);
+ return;
+ default:
+ ERR(REG_ASSERT);
+ return;
+
+ /*
+ * Then plain characters, and minor variants on that theme.
+ */
+
+ case ')': /* unbalanced paren */
+ if ((v->cflags&REG_ADVANCED) != REG_EXTENDED) {
+ ERR(REG_EPAREN);
+ return;
+ }
+
+ /*
+ * Legal in EREs due to specification botch.
+ */
+
+ NOTE(REG_UPBOTCH);
+ /* fallthrough into case PLAIN */
+ case PLAIN:
+ onechr(v, v->nextvalue, lp, rp);
+ okcolors(v->nfa, v->cm);
+ NOERR();
+ NEXT();
+ break;
+ case '[':
+ if (v->nextvalue == 1) {
+ bracket(v, lp, rp);
+ } else {
+ cbracket(v, lp, rp);
+ }
+ assert(SEE(']') || ISERR());
+ NEXT();
+ break;
+ case '.':
+ rainbow(v->nfa, v->cm, PLAIN,
+ (v->cflags&REG_NLSTOP) ? v->nlcolor : COLORLESS, lp, rp);
+ NEXT();
+ break;
+
+ /*
+ * And finally the ugly stuff.
+ */
+
+ case '(': /* value flags as capturing or non */
+ cap = (type == LACON) ? 0 : v->nextvalue;
+ if (cap) {
+ v->nsubexp++;
+ subno = v->nsubexp;
+ if ((size_t)subno >= v->nsubs) {
+ moresubs(v, subno);
+ }
+ assert((size_t)subno < v->nsubs);
+ } else {
+ atomtype = PLAIN; /* something that's not '(' */
+ }
+ NEXT();
+
+ /*
+ * Need new endpoints because tree will contain pointers.
+ */
+
+ s = newstate(v->nfa);
+ s2 = newstate(v->nfa);
+ NOERR();
+ EMPTYARC(lp, s);
+ EMPTYARC(s2, rp);
+ NOERR();
+ atom = parse(v, ')', PLAIN, s, s2);
+ assert(SEE(')') || ISERR());
+ NEXT();
+ NOERR();
+ if (cap) {
+ v->subs[subno] = atom;
+ t = subre(v, '(', atom->flags|CAP, lp, rp);
+ NOERR();
+ t->subno = subno;
+ t->left = atom;
+ atom = t;
+ }
+
+ /*
+ * Postpone everything else pending possible {0}.
+ */
+
+ break;
+ case BACKREF: /* the Feature From The Black Lagoon */
+ INSIST(type != LACON, REG_ESUBREG);
+ INSIST(v->nextvalue < v->nsubs, REG_ESUBREG);
+ INSIST(v->subs[v->nextvalue] != NULL, REG_ESUBREG);
+ NOERR();
+ assert(v->nextvalue > 0);
+ atom = subre(v, 'b', BACKR, lp, rp);
+ NOERR();
+ subno = v->nextvalue;
+ atom->subno = subno;
+ EMPTYARC(lp, rp); /* temporarily, so there's something */
+ NEXT();
+ break;
+ }
+
+ /*
+ * ...and an atom may be followed by a quantifier.
+ */
+
+ switch (v->nexttype) {
+ case '*':
+ m = 0;
+ n = DUPINF;
+ qprefer = (v->nextvalue) ? LONGER : SHORTER;
+ NEXT();
+ break;
+ case '+':
+ m = 1;
+ n = DUPINF;
+ qprefer = (v->nextvalue) ? LONGER : SHORTER;
+ NEXT();
+ break;
+ case '?':
+ m = 0;
+ n = 1;
+ qprefer = (v->nextvalue) ? LONGER : SHORTER;
+ NEXT();
+ break;
+ case '{':
+ NEXT();
+ m = scannum(v);
+ if (EAT(',')) {
+ if (SEE(DIGIT)) {
+ n = scannum(v);
+ } else {
+ n = DUPINF;
+ }
+ if (m > n) {
+ ERR(REG_BADBR);
+ return;
+ }
+
+ /*
+ * {m,n} exercises preference, even if it's {m,m}
+ */
+
+ qprefer = (v->nextvalue) ? LONGER : SHORTER;
+ } else {
+ n = m;
+ /*
+ * {m} passes operand's preference through.
+ */
+
+ qprefer = 0;
+ }
+ if (!SEE('}')) { /* catches errors too */
+ ERR(REG_BADBR);
+ return;
+ }
+ NEXT();
+ break;
+ default: /* no quantifier */
+ m = n = 1;
+ qprefer = 0;
+ break;
+ }
+
+ /*
+ * Annoying special case: {0} or {0,0} cancels everything.
+ */
+
+ if (m == 0 && n == 0) {
+ if (atom != NULL) {
+ freesubre(v, atom);
+ }
+ if (atomtype == '(') {
+ v->subs[subno] = NULL;
+ }
+ delsub(v->nfa, lp, rp);
+ EMPTYARC(lp, rp);
+ return;
+ }
+
+ /*
+ * If not a messy case, avoid hard part.
+ */
+
+ assert(!MESSY(top->flags));
+ f = top->flags | qprefer | ((atom != NULL) ? atom->flags : 0);
+ if (atomtype != '(' && atomtype != BACKREF && !MESSY(UP(f))) {
+ if (!(m == 1 && n == 1)) {
+ repeat(v, lp, rp, m, n);
+ }
+ if (atom != NULL) {
+ freesubre(v, atom);
+ }
+ top->flags = f;
+ return;
+ }
+
+ /*
+ * hard part: something messy
+ * That is, capturing parens, back reference, short/long clash, or an atom
+ * with substructure containing one of those.
+ */
+
+ /*
+ * Now we'll need a subre for the contents even if they're boring.
+ */
+
+ if (atom == NULL) {
+ atom = subre(v, '=', 0, lp, rp);
+ NOERR();
+ }
+
+ /*
+ * Prepare a general-purpose state skeleton.
+ *
+ * In the no-backrefs case, we want this:
+ *
+ * [lp] ---> [s] ---prefix---> [begin] ---atom---> [end] ---rest---> [rp]
+ *
+ * where prefix is some repetitions of atom. In the general case we need
+ *
+ * [lp] ---> [s] ---iterator---> [s2] ---rest---> [rp]
+ *
+ * where the iterator wraps around [begin] ---atom---> [end]
+ *
+ * We make the s state here for both cases; s2 is made below if needed
+ */
+
+ s = newstate(v->nfa); /* first, new endpoints for the atom */
+ s2 = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ moveins(v->nfa, rp, s2);
+ NOERR();
+ atom->begin = s;
+ atom->end = s2;
+ s = newstate(v->nfa); /* set up starting state */
+ NOERR();
+ EMPTYARC(lp, s);
+ NOERR();
+
+ /*
+ * Break remaining subRE into x{...} and what follows.
+ */
+
+ t = subre(v, '.', COMBINE(qprefer, atom->flags), lp, rp);
+ NOERR();
+ t->left = atom;
+ atomp = &t->left;
+
+ /*
+ * Here we should recurse... but we must postpone that to the end.
+ */
+
+ /*
+ * Split top into prefix and remaining.
+ */
+
+ assert(top->op == '=' && top->left == NULL && top->right == NULL);
+ top->left = subre(v, '=', top->flags, top->begin, lp);
+ NOERR();
+ top->op = '.';
+ top->right = t;
+
+ /*
+ * If it's a backref, now is the time to replicate the subNFA.
+ */
+
+ if (atomtype == BACKREF) {
+ assert(atom->begin->nouts == 1); /* just the EMPTY */
+ delsub(v->nfa, atom->begin, atom->end);
+ assert(v->subs[subno] != NULL);
+
+ /*
+ * And here's why the recursion got postponed: it must wait until the
+ * skeleton is filled in, because it may hit a backref that wants to
+ * copy the filled-in skeleton.
+ */
+
+ dupnfa(v->nfa, v->subs[subno]->begin, v->subs[subno]->end,
+ atom->begin, atom->end);
+ NOERR();
+ }
+
+ /*
+ * It's quantifier time. If the atom is just a backref, we'll let it deal
+ * with quantifiers internally.
+ */
+
+ if (atomtype == BACKREF) {
+ /*
+ * Special case: backrefs have internal quantifiers.
+ */
+
+ EMPTYARC(s, atom->begin); /* empty prefix */
+
+ /*
+ * Just stuff everything into atom.
+ */
+
+ repeat(v, atom->begin, atom->end, m, n);
+ atom->min = (short) m;
+ atom->max = (short) n;
+ atom->flags |= COMBINE(qprefer, atom->flags);
+ /* rest of branch can be strung starting from atom->end */
+ s2 = atom->end;
+ } else if (m == 1 && n == 1) {
+ /*
+ * No/vacuous quantifier: done.
+ */
+
+ EMPTYARC(s, atom->begin); /* empty prefix */
+ /* rest of branch can be strung starting from atom->end */
+ s2 = atom->end;
+ } else if (m > 0 && !(atom->flags & BACKR)) {
+ /*
+ * If there's no backrefs involved, we can turn x{m,n} into
+ * x{m-1,n-1}x, with capturing parens in only the second x. This
+ * is valid because we only care about capturing matches from the
+ * final iteration of the quantifier. It's a win because we can
+ * implement the backref-free left side as a plain DFA node, since
+ * we don't really care where its submatches are.
+ */
+
+ dupnfa(v->nfa, atom->begin, atom->end, s, atom->begin);
+ assert(m >= 1 && m != DUPINF && n >= 1);
+ repeat(v, s, atom->begin, m-1, (n == DUPINF) ? n : n-1);
+ f = COMBINE(qprefer, atom->flags);
+ t = subre(v, '.', f, s, atom->end); /* prefix and atom */
+ NOERR();
+ t->left = subre(v, '=', PREF(f), s, atom->begin);
+ NOERR();
+ t->right = atom;
+ *atomp = t;
+ /* rest of branch can be strung starting from atom->end */
+ s2 = atom->end;
+ } else {
+ /* general case: need an iteration node */
+ s2 = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, atom->end, s2);
+ NOERR();
+ dupnfa(v->nfa, atom->begin, atom->end, s, s2);
+ repeat(v, s, s2, m, n);
+ f = COMBINE(qprefer, atom->flags);
+ t = subre(v, '*', f, s, s2);
+ NOERR();
+ t->min = (short) m;
+ t->max = (short) n;
+ t->left = atom;
+ *atomp = t;
+ /* rest of branch is to be strung from iteration's end state */
+ }
+
+ /*
+ * And finally, look after that postponed recursion.
+ */
+
+ t = top->right;
+ if (!(SEE('|') || SEE(stopper) || SEE(EOS))) {
+ t->right = parsebranch(v, stopper, type, s2, rp, 1);
+ } else {
+ EMPTYARC(s2, rp);
+ t->right = subre(v, '=', 0, s2, rp);
+ }
+ NOERR();
+ assert(SEE('|') || SEE(stopper) || SEE(EOS));
+ t->flags |= COMBINE(t->flags, t->right->flags);
+ top->flags |= COMBINE(top->flags, t->flags);
+}
+
+/*
+ - nonword - generate arcs for non-word-character ahead or behind
+ ^ static void nonword(struct vars *, int, struct state *, struct state *);
+ */
+static void
+nonword(
+ struct vars *v,
+ int dir, /* AHEAD or BEHIND */
+ struct state *lp,
+ struct state *rp)
+{
+ int anchor = (dir == AHEAD) ? '$' : '^';
+
+ assert(dir == AHEAD || dir == BEHIND);
+ newarc(v->nfa, anchor, 1, lp, rp);
+ newarc(v->nfa, anchor, 0, lp, rp);
+ colorcomplement(v->nfa, v->cm, dir, v->wordchrs, lp, rp);
+ /* (no need for special attention to \n) */
+}
+
+/*
+ - word - generate arcs for word character ahead or behind
+ ^ static void word(struct vars *, int, struct state *, struct state *);
+ */
+static void
+word(
+ struct vars *v,
+ int dir, /* AHEAD or BEHIND */
+ struct state *lp,
+ struct state *rp)
+{
+ assert(dir == AHEAD || dir == BEHIND);
+ cloneouts(v->nfa, v->wordchrs, lp, rp, dir);
+ /* (no need for special attention to \n) */
+}
+
+/*
+ - scannum - scan a number
+ ^ static int scannum(struct vars *);
+ */
+static int /* value, <= DUPMAX */
+scannum(
+ struct vars *v)
+{
+ int n = 0;
+
+ while (SEE(DIGIT) && n < DUPMAX) {
+ n = n*10 + v->nextvalue;
+ NEXT();
+ }
+ if (SEE(DIGIT) || n > DUPMAX) {
+ ERR(REG_BADBR);
+ return 0;
+ }
+ return n;
+}
+
+/*
+ - repeat - replicate subNFA for quantifiers
+ * The sub-NFA strung from lp to rp is modified to represent m to n
+ * repetitions of its initial contents.
+ * The duplication sequences used here are chosen carefully so that any
+ * pointers starting out pointing into the subexpression end up pointing into
+ * the last occurrence. (Note that it may not be strung between the same left
+ * and right end states, however!) This used to be important for the subRE
+ * tree, although the important bits are now handled by the in-line code in
+ * parse(), and when this is called, it doesn't matter any more.
+ ^ static void repeat(struct vars *, struct state *, struct state *, int, int);
+ */
+static void
+repeat(
+ struct vars *v,
+ struct state *lp,
+ struct state *rp,
+ int m,
+ int n)
+{
+#define SOME 2
+#define INF 3
+#define PAIR(x, y) ((x)*4 + (y))
+#define REDUCE(x) ( ((x) == DUPINF) ? INF : (((x) > 1) ? SOME : (x)) )
+ const int rm = REDUCE(m);
+ const int rn = REDUCE(n);
+ struct state *s, *s2;
+
+ switch (PAIR(rm, rn)) {
+ case PAIR(0, 0): /* empty string */
+ delsub(v->nfa, lp, rp);
+ EMPTYARC(lp, rp);
+ break;
+ case PAIR(0, 1): /* do as x| */
+ EMPTYARC(lp, rp);
+ break;
+ case PAIR(0, SOME): /* do as x{1,n}| */
+ repeat(v, lp, rp, 1, n);
+ NOERR();
+ EMPTYARC(lp, rp);
+ break;
+ case PAIR(0, INF): /* loop x around */
+ s = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ moveins(v->nfa, rp, s);
+ EMPTYARC(lp, s);
+ EMPTYARC(s, rp);
+ break;
+ case PAIR(1, 1): /* no action required */
+ break;
+ case PAIR(1, SOME): /* do as x{0,n-1}x = (x{1,n-1}|)x */
+ s = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ dupnfa(v->nfa, s, rp, lp, s);
+ NOERR();
+ repeat(v, lp, s, 1, n-1);
+ NOERR();
+ EMPTYARC(lp, s);
+ break;
+ case PAIR(1, INF): /* add loopback arc */
+ s = newstate(v->nfa);
+ s2 = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ moveins(v->nfa, rp, s2);
+ EMPTYARC(lp, s);
+ EMPTYARC(s2, rp);
+ EMPTYARC(s2, s);
+ break;
+ case PAIR(SOME, SOME): /* do as x{m-1,n-1}x */
+ s = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ dupnfa(v->nfa, s, rp, lp, s);
+ NOERR();
+ repeat(v, lp, s, m-1, n-1);
+ break;
+ case PAIR(SOME, INF): /* do as x{m-1,}x */
+ s = newstate(v->nfa);
+ NOERR();
+ moveouts(v->nfa, lp, s);
+ dupnfa(v->nfa, s, rp, lp, s);
+ NOERR();
+ repeat(v, lp, s, m-1, n);
+ break;
+ default:
+ ERR(REG_ASSERT);
+ break;
+ }
+}
+
+/*
+ - bracket - handle non-complemented bracket expression
+ * Also called from cbracket for complemented bracket expressions.
+ ^ static void bracket(struct vars *, struct state *, struct state *);
+ */
+static void
+bracket(
+ struct vars *v,
+ struct state *lp,
+ struct state *rp)
+{
+ assert(SEE('['));
+ NEXT();
+ while (!SEE(']') && !SEE(EOS)) {
+ brackpart(v, lp, rp);
+ }
+ assert(SEE(']') || ISERR());
+ okcolors(v->nfa, v->cm);
+}
+
+/*
+ - cbracket - handle complemented bracket expression
+ * We do it by calling bracket() with dummy endpoints, and then complementing
+ * the result. The alternative would be to invoke rainbow(), and then delete
+ * arcs as the b.e. is seen... but that gets messy.
+ ^ static void cbracket(struct vars *, struct state *, struct state *);
+ */
+static void
+cbracket(
+ struct vars *v,
+ struct state *lp,
+ struct state *rp)
+{
+ struct state *left = newstate(v->nfa);
+ struct state *right = newstate(v->nfa);
+
+ NOERR();
+ bracket(v, left, right);
+ if (v->cflags&REG_NLSTOP) {
+ newarc(v->nfa, PLAIN, v->nlcolor, left, right);
+ }
+ NOERR();
+
+ assert(lp->nouts == 0); /* all outarcs will be ours */
+
+ /*
+ * Easy part of complementing, and all there is to do since the MCCE code
+ * was removed.
+ */
+
+ colorcomplement(v->nfa, v->cm, PLAIN, left, lp, rp);
+ NOERR();
+ dropstate(v->nfa, left);
+ assert(right->nins == 0);
+ freestate(v->nfa, right);
+ return;
+}
+
+/*
+ - brackpart - handle one item (or range) within a bracket expression
+ ^ static void brackpart(struct vars *, struct state *, struct state *);
+ */
+static void
+brackpart(
+ struct vars *v,
+ struct state *lp,
+ struct state *rp)
+{
+ celt startc, endc;
+ struct cvec *cv;
+ const chr *startp, *endp;
+ chr c;
+
+ /*
+ * Parse something, get rid of special cases, take shortcuts.
+ */
+
+ switch (v->nexttype) {
+ case RANGE: /* a-b-c or other botch */
+ ERR(REG_ERANGE);
+ return;
+ break;
+ case PLAIN:
+ c = v->nextvalue;
+ NEXT();
+
+ /*
+ * Shortcut for ordinary chr (not range).
+ */
+
+ if (!SEE(RANGE)) {
+ onechr(v, c, lp, rp);
+ return;
+ }
+ startc = element(v, &c, &c+1);
+ NOERR();
+ break;
+ case COLLEL:
+ startp = v->now;
+ endp = scanplain(v);
+ INSIST(startp < endp, REG_ECOLLATE);
+ NOERR();
+ startc = element(v, startp, endp);
+ NOERR();
+ break;
+ case ECLASS:
+ startp = v->now;
+ endp = scanplain(v);
+ INSIST(startp < endp, REG_ECOLLATE);
+ NOERR();
+ startc = element(v, startp, endp);
+ NOERR();
+ cv = eclass(v, startc, (v->cflags&REG_ICASE));
+ NOERR();
+ dovec(v, cv, lp, rp);
+ return;
+ break;
+ case CCLASS:
+ startp = v->now;
+ endp = scanplain(v);
+ INSIST(startp < endp, REG_ECTYPE);
+ NOERR();
+ cv = cclass(v, startp, endp, (v->cflags&REG_ICASE));
+ NOERR();
+ dovec(v, cv, lp, rp);
+ return;
+ break;
+ default:
+ ERR(REG_ASSERT);
+ return;
+ break;
+ }
+
+ if (SEE(RANGE)) {
+ NEXT();
+ switch (v->nexttype) {
+ case PLAIN:
+ case RANGE:
+ c = v->nextvalue;
+ NEXT();
+ endc = element(v, &c, &c+1);
+ NOERR();
+ break;
+ case COLLEL:
+ startp = v->now;
+ endp = scanplain(v);
+ INSIST(startp < endp, REG_ECOLLATE);
+ NOERR();
+ endc = element(v, startp, endp);
+ NOERR();
+ break;
+ default:
+ ERR(REG_ERANGE);
+ return;
+ break;
+ }
+ } else {
+ endc = startc;
+ }
+
+ /*
+ * Ranges are unportable. Actually, standard C does guarantee that digits
+ * are contiguous, but making that an exception is just too complicated.
+ */
+
+ if (startc != endc) {
+ NOTE(REG_UUNPORT);
+ }
+ cv = range(v, startc, endc, (v->cflags&REG_ICASE));
+ NOERR();
+ dovec(v, cv, lp, rp);
+}
+
+/*
+ - scanplain - scan PLAIN contents of [. etc.
+ * Certain bits of trickery in lex.c know that this code does not try to look
+ * past the final bracket of the [. etc.
+ ^ static const chr *scanplain(struct vars *);
+ */
+static const chr * /* just after end of sequence */
+scanplain(
+ struct vars *v)
+{
+ const chr *endp;
+
+ assert(SEE(COLLEL) || SEE(ECLASS) || SEE(CCLASS));
+ NEXT();
+
+ endp = v->now;
+ while (SEE(PLAIN)) {
+ endp = v->now;
+ NEXT();
+ }
+
+ assert(SEE(END) || ISERR());
+ NEXT();
+
+ return endp;
+}
+
+/*
+ - onechr - fill in arcs for a plain character, and possible case complements
+ * This is mostly a shortcut for efficient handling of the common case.
+ ^ static void onechr(struct vars *, pchr, struct state *, struct state *);
+ */
+static void
+onechr(
+ struct vars *v,
+ pchr c,
+ struct state *lp,
+ struct state *rp)
+{
+ if (!(v->cflags&REG_ICASE)) {
+ newarc(v->nfa, PLAIN, subcolor(v->cm, c), lp, rp);
+ return;
+ }
+
+ /*
+ * Rats, need general case anyway...
+ */
+
+ dovec(v, allcases(v, c), lp, rp);
+}
+
+/*
+ - dovec - fill in arcs for each element of a cvec
+ ^ static void dovec(struct vars *, struct cvec *, struct state *,
+ ^ struct state *);
+ */
+static void
+dovec(
+ struct vars *v,
+ struct cvec *cv,
+ struct state *lp,
+ struct state *rp)
+{
+ chr ch, from, to;
+ const chr *p;
+ int i;
+
+ for (p = cv->chrs, i = cv->nchrs; i > 0; p++, i--) {
+ ch = *p;
+ newarc(v->nfa, PLAIN, subcolor(v->cm, ch), lp, rp);
+ }
+
+ for (p = cv->ranges, i = cv->nranges; i > 0; p += 2, i--) {
+ from = *p;
+ to = *(p+1);
+ if (from <= to) {
+ subrange(v, from, to, lp, rp);
+ }
+ }
+
+}
+
+/*
+ - wordchrs - set up word-chr list for word-boundary stuff, if needed
+ * The list is kept as a bunch of arcs between two dummy states; it's disposed
+ * of by the unreachable-states sweep in NFA optimization. Does NEXT(). Must
+ * not be called from any unusual lexical context. This should be reconciled
+ * with the \w etc. handling in lex.c, and should be cleaned up to reduce
+ * dependencies on input scanning.
+ ^ static void wordchrs(struct vars *);
+ */
+static void
+wordchrs(
+ struct vars *v)
+{
+ struct state *left, *right;
+
+ if (v->wordchrs != NULL) {
+ NEXT(); /* for consistency */
+ return;
+ }
+
+ left = newstate(v->nfa);
+ right = newstate(v->nfa);
+ NOERR();
+
+ /*
+ * Fine point: implemented with [::], and lexer will set REG_ULOCALE.
+ */
+
+ lexword(v);
+ NEXT();
+ assert(v->savenow != NULL && SEE('['));
+ bracket(v, left, right);
+ assert((v->savenow != NULL && SEE(']')) || ISERR());
+ NEXT();
+ NOERR();
+ v->wordchrs = left;
+}
+
+/*
+ - subre - allocate a subre
+ ^ static struct subre *subre(struct vars *, int, int, struct state *,
+ ^ struct state *);
+ */
+static struct subre *
+subre(
+ struct vars *v,
+ int op,
+ int flags,
+ struct state *begin,
+ struct state *end)
+{
+ struct subre *ret = v->treefree;
+
+ if (ret != NULL) {
+ v->treefree = ret->left;
+ } else {
+ ret = (struct subre *) MALLOC(sizeof(struct subre));
+ if (ret == NULL) {
+ ERR(REG_ESPACE);
+ return NULL;
+ }
+ ret->chain = v->treechain;
+ v->treechain = ret;
+ }
+
+ assert(strchr("=b|.*(", op) != NULL);
+
+ ret->op = op;
+ ret->flags = flags;
+ ret->id = 0; /* will be assigned later */
+ ret->subno = 0;
+ ret->min = ret->max = 1;
+ ret->left = NULL;
+ ret->right = NULL;
+ ret->begin = begin;
+ ret->end = end;
+ ZAPCNFA(ret->cnfa);
+
+ return ret;
+}
+
+/*
+ - freesubre - free a subRE subtree
+ ^ static void freesubre(struct vars *, struct subre *);
+ */
+static void
+freesubre(
+ struct vars *v, /* might be NULL */
+ struct subre *sr)
+{
+ if (sr == NULL) {
+ return;
+ }
+
+ if (sr->left != NULL) {
+ freesubre(v, sr->left);
+ }
+ if (sr->right != NULL) {
+ freesubre(v, sr->right);
+ }
+
+ freesrnode(v, sr);
+}
+
+/*
+ - freesrnode - free one node in a subRE subtree
+ ^ static void freesrnode(struct vars *, struct subre *);
+ */
+static void
+freesrnode(
+ struct vars *v, /* might be NULL */
+ struct subre *sr)
+{
+ if (sr == NULL) {
+ return;
+ }
+
+ if (!NULLCNFA(sr->cnfa)) {
+ freecnfa(&sr->cnfa);
+ }
+ sr->flags = 0;
+
+ if (v != NULL && v->treechain != NULL) {
+ /* we're still parsing, maybe we can reuse the subre */
+ sr->left = v->treefree;
+ v->treefree = sr;
+ } else {
+ FREE(sr);
+ }
+}
+
+/*
+ - optst - optimize a subRE subtree
+ ^ static void optst(struct vars *, struct subre *);
+ */
+static void
+optst(
+ struct vars *v,
+ struct subre *t)
+{
+ /*
+ * DGP (2007-11-13): I assume it was the programmer's intent to eventually
+ * come back and add code to optimize subRE trees, but the routine coded
+ * just spends effort traversing the tree and doing nothing. We can do
+ * nothing with less effort.
+ */
+
+ return;
+}
+
+/*
+ - numst - number tree nodes (assigning "id" indexes)
+ ^ static int numst(struct subre *, int);
+ */
+static int /* next number */
+numst(
+ struct subre *t,
+ int start) /* starting point for subtree numbers */
+{
+ int i;
+
+ assert(t != NULL);
+
+ i = start;
+ t->id = (short) i++;
+ if (t->left != NULL) {
+ i = numst(t->left, i);
+ }
+ if (t->right != NULL) {
+ i = numst(t->right, i);
+ }
+ return i;
+}
+
+/*
+ - markst - mark tree nodes as INUSE
+ * Note: this is a great deal more subtle than it looks. During initial
+ * parsing of a regex, all subres are linked into the treechain list;
+ * discarded ones are also linked into the treefree list for possible reuse.
+ * After we are done creating all subres required for a regex, we run markst()
+ * then cleanst(), which results in discarding all subres not reachable from
+ * v->tree. We then clear v->treechain, indicating that subres must be found
+ * by descending from v->tree. This changes the behavior of freesubre(): it
+ * will henceforth FREE() unwanted subres rather than sticking them into the
+ * treefree list. (Doing that any earlier would result in dangling links in
+ * the treechain list.) This all means that freev() will clean up correctly
+ * if invoked before or after markst()+cleanst(); but it would not work if
+ * called partway through this state conversion, so we mustn't error out
+ * in or between these two functions.
+ ^ static void markst(struct subre *);
+ */
+static void
+markst(
+ struct subre *t)
+{
+ assert(t != NULL);
+
+ t->flags |= INUSE;
+ if (t->left != NULL) {
+ markst(t->left);
+ }
+ if (t->right != NULL) {
+ markst(t->right);
+ }
+}
+
+/*
+ - cleanst - free any tree nodes not marked INUSE
+ ^ static void cleanst(struct vars *);
+ */
+static void
+cleanst(
+ struct vars *v)
+{
+ struct subre *t;
+ struct subre *next;
+
+ for (t = v->treechain; t != NULL; t = next) {
+ next = t->chain;
+ if (!(t->flags&INUSE)) {
+ FREE(t);
+ }
+ }
+ v->treechain = NULL;
+ v->treefree = NULL; /* just on general principles */
+}
+
+/*
+ - nfatree - turn a subRE subtree into a tree of compacted NFAs
+ ^ static long nfatree(struct vars *, struct subre *, FILE *);
+ */
+static long /* optimize results from top node */
+nfatree(
+ struct vars *v,
+ struct subre *t,
+ FILE *f) /* for debug output */
+{
+ assert(t != NULL && t->begin != NULL);
+
+ if (t->left != NULL) {
+ (void) nfatree(v, t->left, f);
+ }
+ if (t->right != NULL) {
+ (void) nfatree(v, t->right, f);
+ }
+
+ return nfanode(v, t, f);
+}
+
+/*
+ - nfanode - do one NFA for nfatree
+ ^ static long nfanode(struct vars *, struct subre *, FILE *);
+ */
+static long /* optimize results */
+nfanode(
+ struct vars *v,
+ struct subre *t,
+ FILE *f) /* for debug output */
+{
+ struct nfa *nfa;
+ long ret = 0;
+ char idbuf[50];
+
+ assert(t->begin != NULL);
+
+ if (f != NULL) {
+ fprintf(f, "\n\n\n========= TREE NODE %s ==========\n",
+ stid(t, idbuf, sizeof(idbuf)));
+ }
+ nfa = newnfa(v, v->cm, v->nfa);
+ NOERRZ();
+ dupnfa(nfa, t->begin, t->end, nfa->init, nfa->final);
+ if (!ISERR()) {
+ specialcolors(nfa);
+ ret = optimize(nfa, f);
+ }
+ if (!ISERR()) {
+ compact(nfa, &t->cnfa);
+ }
+
+ freenfa(nfa);
+ return ret;
+}
+
+/*
+ - newlacon - allocate a lookahead-constraint subRE
+ ^ static int newlacon(struct vars *, struct state *, struct state *, int);
+ */
+static int /* lacon number */
+newlacon(
+ struct vars *v,
+ struct state *begin,
+ struct state *end,
+ int pos)
+{
+ int n;
+ struct subre *newlacons;
+ struct subre *sub;
+
+ if (v->nlacons == 0) {
+ n = 1; /* skip 0th */
+ newlacons = (struct subre *) MALLOC(2 * sizeof(struct subre));
+ } else {
+ n = v->nlacons;
+ newlacons = (struct subre *) REALLOC(v->lacons,
+ (n + 1) * sizeof(struct subre));
+ }
+
+ if (newlacons == NULL) {
+ ERR(REG_ESPACE);
+ return 0;
+ }
+
+ v->lacons = newlacons;
+ v->nlacons = n + 1;
+ sub = &v->lacons[n];
+ sub->begin = begin;
+ sub->end = end;
+ sub->subno = pos;
+ ZAPCNFA(sub->cnfa);
+ return n;
+}
+
+/*
+ - freelacons - free lookahead-constraint subRE vector
+ ^ static void freelacons(struct subre *, int);
+ */
+static void
+freelacons(
+ struct subre *subs,
+ int n)
+{
+ struct subre *sub;
+ int i;
+
+ assert(n > 0);
+ for (sub=subs+1, i=n-1; i>0; sub++, i--) { /* no 0th */
+ if (!NULLCNFA(sub->cnfa)) {
+ freecnfa(&sub->cnfa);
+ }
+ }
+ FREE(subs);
+}
+
+/*
+ - rfree - free a whole RE (insides of regfree)
+ ^ static void rfree(regex_t *);
+ */
+static void
+rfree(
+ regex_t *re)
+{
+ struct guts *g;
+
+ if (re == NULL || re->re_magic != REMAGIC) {
+ return;
+ }
+
+ re->re_magic = 0; /* invalidate RE */
+ g = (struct guts *) re->re_guts;
+ re->re_guts = NULL;
+ re->re_fns = NULL;
+ if (g != NULL) {
+ g->magic = 0;
+ freecm(&g->cmap);
+ if (g->tree != NULL) {
+ freesubre(NULL, g->tree);
+ }
+ if (g->lacons != NULL) {
+ freelacons(g->lacons, g->nlacons);
+ }
+ if (!NULLCNFA(g->search)) {
+ freecnfa(&g->search);
+ }
+ FREE(g);
+ }
+}
+
+/*
+ - dump - dump an RE in human-readable form
+ ^ static void dump(regex_t *, FILE *);
+ */
+static void
+dump(
+ regex_t *re,
+ FILE *f)
+{
+#ifdef REG_DEBUG
+ struct guts *g;
+ int i;
+
+ if (re->re_magic != REMAGIC) {
+ fprintf(f, "bad magic number (0x%x not 0x%x)\n",
+ re->re_magic, REMAGIC);
+ }
+ if (re->re_guts == NULL) {
+ fprintf(f, "NULL guts!!!\n");
+ return;
+ }
+ g = (struct guts *) re->re_guts;
+ if (g->magic != GUTSMAGIC) {
+ fprintf(f, "bad guts magic number (0x%x not 0x%x)\n",
+ g->magic, GUTSMAGIC);
+ }
+
+ fprintf(f, "\n\n\n========= DUMP ==========\n");
+ fprintf(f, "nsub %d, info 0%lo, csize %d, ntree %d\n",
+ (int) re->re_nsub, re->re_info, re->re_csize, g->ntree);
+
+ dumpcolors(&g->cmap, f);
+ if (!NULLCNFA(g->search)) {
+ fprintf(f, "\nsearch:\n");
+ dumpcnfa(&g->search, f);
+ }
+ for (i = 1; i < g->nlacons; i++) {
+ fprintf(f, "\nla%d (%s):\n", i,
+ (g->lacons[i].subno) ? "positive" : "negative");
+ dumpcnfa(&g->lacons[i].cnfa, f);
+ }
+ fprintf(f, "\n");
+ dumpst(g->tree, f, 0);
+#endif
+}
+
+/*
+ - dumpst - dump a subRE tree
+ ^ static void dumpst(struct subre *, FILE *, int);
+ */
+static void
+dumpst(
+ struct subre *t,
+ FILE *f,
+ int nfapresent) /* is the original NFA still around? */
+{
+ if (t == NULL) {
+ fprintf(f, "null tree\n");
+ } else {
+ stdump(t, f, nfapresent);
+ }
+ fflush(f);
+}
+
+/*
+ - stdump - recursive guts of dumpst
+ ^ static void stdump(struct subre *, FILE *, int);
+ */
+static void
+stdump(
+ struct subre *t,
+ FILE *f,
+ int nfapresent) /* is the original NFA still around? */
+{
+ char idbuf[50];
+
+ fprintf(f, "%s. `%c'", stid(t, idbuf, sizeof(idbuf)), t->op);
+ if (t->flags&LONGER) {
+ fprintf(f, " longest");
+ }
+ if (t->flags&SHORTER) {
+ fprintf(f, " shortest");
+ }
+ if (t->flags&MIXED) {
+ fprintf(f, " hasmixed");
+ }
+ if (t->flags&CAP) {
+ fprintf(f, " hascapture");
+ }
+ if (t->flags&BACKR) {
+ fprintf(f, " hasbackref");
+ }
+ if (!(t->flags&INUSE)) {
+ fprintf(f, " UNUSED");
+ }
+ if (t->subno != 0) {
+ fprintf(f, " (#%d)", t->subno);
+ }
+ if (t->min != 1 || t->max != 1) {
+ fprintf(f, " {%d,", t->min);
+ if (t->max != DUPINF) {
+ fprintf(f, "%d", t->max);
+ }
+ fprintf(f, "}");
+ }
+ if (nfapresent) {
+ fprintf(f, " %ld-%ld", (long)t->begin->no, (long)t->end->no);
+ }
+ if (t->left != NULL) {
+ fprintf(f, " L:%s", stid(t->left, idbuf, sizeof(idbuf)));
+ }
+ if (t->right != NULL) {
+ fprintf(f, " R:%s", stid(t->right, idbuf, sizeof(idbuf)));
+ }
+ if (!NULLCNFA(t->cnfa)) {
+ fprintf(f, "\n");
+ dumpcnfa(&t->cnfa, f);
+ }
+ fprintf(f, "\n");
+ if (t->left != NULL) {
+ stdump(t->left, f, nfapresent);
+ }
+ if (t->right != NULL) {
+ stdump(t->right, f, nfapresent);
+ }
+}
+
+/*
+ - stid - identify a subtree node for dumping
+ ^ static const char *stid(struct subre *, char *, size_t);
+ */
+static const char * /* points to buf or constant string */
+stid(
+ struct subre *t,
+ char *buf,
+ size_t bufsize)
+{
+ /*
+ * Big enough for hex int or decimal t->id?
+ */
+
+ if (bufsize < sizeof(void*)*2 + 3 || bufsize < sizeof(t->id)*3 + 1) {
+ return "unable";
+ }
+ if (t->id != 0) {
+ sprintf(buf, "%d", t->id);
+ } else {
+ sprintf(buf, "%p", t);
+ }
+ return buf;
+}
+
+#include "regc_lex.c"
+#include "regc_color.c"
+#include "regc_nfa.c"
+#include "regc_cvec.c"
+#include "regc_locale.c"
+
+/*
+ * Local Variables:
+ * mode: c
+ * c-basic-offset: 4
+ * fill-column: 78
+ * End:
+ */
generated by cgit v0.12 at 2024-09-28 21:53:54 (GMT)