+
+/*
+ - zapmem - initialize the retry memory of a subtree to zeros
+ ^ static VOID zapmem(struct vars *, struct subre *);
+ */
+static VOID
+zapmem(v, t)
+struct vars *v;
+struct subre *t;
+{
+ if (t == NULL)
+ return;
+
+ assert(v->mem != NULL);
+ v->mem[t->retry] = 0;
+ if (t->op == '(') {
+ assert(t->subno > 0);
+ v->pmatch[t->subno].rm_so = -1;
+ v->pmatch[t->subno].rm_eo = -1;
+ }
+
+ if (t->left != NULL)
+ zapmem(v, t->left);
+ if (t->right != NULL)
+ zapmem(v, t->right);
+}
+
+/*
+ - subset - set any subexpression relevant to a successful subre
+ ^ static VOID subset(struct vars *, struct subre *, chr *, chr *);
+ */
+static VOID
+subset(v, sub, begin, end)
+struct vars *v;
+struct subre *sub;
+chr *begin;
+chr *end;
+{
+ int n = sub->subno;
+
+ assert(n > 0);
+ if ((size_t)n >= v->nmatch)
+ return;
+
+ MDEBUG(("setting %d\n", n));
+ v->pmatch[n].rm_so = OFF(begin);
+ v->pmatch[n].rm_eo = OFF(end);
+}
+
+/*
+ - dissect - determine subexpression matches (uncomplicated case)
+ ^ static int dissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+dissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ assert(t != NULL);
+ MDEBUG(("dissect %ld-%ld\n", LOFF(begin), LOFF(end)));
+
+ switch (t->op) {
+ case '=': /* terminal node */
+ assert(t->left == NULL && t->right == NULL);
+ return REG_OKAY; /* no action, parent did the work */
+ break;
+ case '|': /* alternation */
+ assert(t->left != NULL);
+ return altdissect(v, t, begin, end);
+ break;
+ case 'b': /* back ref -- shouldn't be calling us! */
+ return REG_ASSERT;
+ break;
+ case '.': /* concatenation */
+ assert(t->left != NULL && t->right != NULL);
+ return condissect(v, t, begin, end);
+ break;
+ case '(': /* capturing */
+ assert(t->left != NULL && t->right == NULL);
+ assert(t->subno > 0);
+ subset(v, t, begin, end);
+ return dissect(v, t->left, begin, end);
+ break;
+ default:
+ return REG_ASSERT;
+ break;
+ }
+}
+
+/*
+ - condissect - determine concatenation subexpression matches (uncomplicated)
+ ^ static int condissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+condissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ struct dfa *d;
+ struct dfa *d2;
+ chr *mid;
+ int i;
+ int shorter = (t->left->flags&SHORTER) ? 1 : 0;
+ chr *stop = (shorter) ? end : begin;
+
+ assert(t->op == '.');
+ assert(t->left != NULL && t->left->cnfa.nstates > 0);
+ assert(t->right != NULL && t->right->cnfa.nstates > 0);
+
+ d = newdfa(v, &t->left->cnfa, &v->g->cmap, &v->dfa1);
+ NOERR();
+ d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, &v->dfa2);
+ if (ISERR()) {
+ assert(d2 == NULL);
+ freedfa(d);
+ return v->err;
+ }
+
+ /* pick a tentative midpoint */
+ if (shorter)
+ mid = shortest(v, d, begin, begin, end, (chr **)NULL,
+ (int *)NULL);
+ else
+ mid = longest(v, d, begin, end, (int *)NULL);
+ if (mid == NULL) {
+ freedfa(d);
+ freedfa(d2);
+ return REG_ASSERT;
+ }
+ MDEBUG(("tentative midpoint %ld\n", LOFF(mid)));
+
+ /* iterate until satisfaction or failure */
+ while (longest(v, d2, mid, end, (int *)NULL) != end) {
+ /* that midpoint didn't work, find a new one */
+ if (mid == stop) {
+ /* all possibilities exhausted! */
+ MDEBUG(("no midpoint!\n"));
+ freedfa(d);
+ freedfa(d2);
+ return REG_ASSERT;
+ }
+ if (shorter)
+ mid = shortest(v, d, begin, mid+1, end, (chr **)NULL,
+ (int *)NULL);
+ else
+ mid = longest(v, d, begin, mid-1, (int *)NULL);
+ if (mid == NULL) {
+ /* failed to find a new one! */
+ MDEBUG(("failed midpoint!\n"));
+ freedfa(d);
+ freedfa(d2);
+ return REG_ASSERT;
+ }
+ MDEBUG(("new midpoint %ld\n", LOFF(mid)));
+ }
+
+ /* satisfaction */
+ MDEBUG(("successful\n"));
+ freedfa(d);
+ freedfa(d2);
+ i = dissect(v, t->left, begin, mid);
+ if (i != REG_OKAY)
+ return i;
+ return dissect(v, t->right, mid, end);
+}
+
+/*
+ - altdissect - determine alternative subexpression matches (uncomplicated)
+ ^ static int altdissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+altdissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ struct dfa *d;
+ int i;
+
+ assert(t != NULL);
+ assert(t->op == '|');
+
+ for (i = 0; t != NULL; t = t->right, i++) {
+ MDEBUG(("trying %dth\n", i));
+ assert(t->left != NULL && t->left->cnfa.nstates > 0);
+ d = newdfa(v, &t->left->cnfa, &v->g->cmap, &v->dfa1);
+ if (ISERR())
+ return v->err;
+ if (longest(v, d, begin, end, (int *)NULL) == end) {
+ MDEBUG(("success\n"));
+ freedfa(d);
+ return dissect(v, t->left, begin, end);
+ }
+ freedfa(d);
+ }
+ return REG_ASSERT; /* none of them matched?!? */
+}
+
+/*
+ - cdissect - determine subexpression matches (with complications)
+ * The retry memory stores the offset of the trial midpoint from begin,
+ * plus 1 so that 0 uniquely means "clean slate".
+ ^ static int cdissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+cdissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ int er;
+
+ assert(t != NULL);
+ MDEBUG(("cdissect %ld-%ld %c\n", LOFF(begin), LOFF(end), t->op));
+
+ switch (t->op) {
+ case '=': /* terminal node */
+ assert(t->left == NULL && t->right == NULL);
+ return REG_OKAY; /* no action, parent did the work */
+ break;
+ case '|': /* alternation */
+ assert(t->left != NULL);
+ return caltdissect(v, t, begin, end);
+ break;
+ case 'b': /* back ref -- shouldn't be calling us! */
+ assert(t->left == NULL && t->right == NULL);
+ return cbrdissect(v, t, begin, end);
+ break;
+ case '.': /* concatenation */
+ assert(t->left != NULL && t->right != NULL);
+ return ccondissect(v, t, begin, end);
+ break;
+ case '(': /* capturing */
+ assert(t->left != NULL && t->right == NULL);
+ assert(t->subno > 0);
+ er = cdissect(v, t->left, begin, end);
+ if (er == REG_OKAY)
+ subset(v, t, begin, end);
+ return er;
+ break;
+ default:
+ return REG_ASSERT;
+ break;
+ }
+}
+
+/*
+ - ccondissect - concatenation subexpression matches (with complications)
+ * The retry memory stores the offset of the trial midpoint from begin,
+ * plus 1 so that 0 uniquely means "clean slate".
+ ^ static int ccondissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+ccondissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ struct dfa *d;
+ struct dfa *d2;
+ chr *mid;
+ int er;
+
+ assert(t->op == '.');
+ assert(t->left != NULL && t->left->cnfa.nstates > 0);
+ assert(t->right != NULL && t->right->cnfa.nstates > 0);
+
+ if (t->left->flags&SHORTER) /* reverse scan */
+ return crevdissect(v, t, begin, end);
+
+ d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC);
+ if (ISERR())
+ return v->err;
+ d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, DOMALLOC);
+ if (ISERR()) {
+ freedfa(d);
+ return v->err;
+ }
+ MDEBUG(("cconcat %d\n", t->retry));
+
+ /* pick a tentative midpoint */
+ if (v->mem[t->retry] == 0) {
+ mid = longest(v, d, begin, end, (int *)NULL);
+ if (mid == NULL) {
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ MDEBUG(("tentative midpoint %ld\n", LOFF(mid)));
+ v->mem[t->retry] = (mid - begin) + 1;
+ } else {
+ mid = begin + (v->mem[t->retry] - 1);
+ MDEBUG(("working midpoint %ld\n", LOFF(mid)));
+ }
+
+ /* iterate until satisfaction or failure */
+ for (;;) {
+ /* try this midpoint on for size */
+ er = cdissect(v, t->left, begin, mid);
+ if (er == REG_OKAY &&
+ longest(v, d2, mid, end, (int *)NULL) == end &&
+ (er = cdissect(v, t->right, mid, end)) ==
+ REG_OKAY)
+ break; /* NOTE BREAK OUT */
+ if (er != REG_OKAY && er != REG_NOMATCH) {
+ freedfa(d);
+ freedfa(d2);
+ return er;
+ }
+
+ /* that midpoint didn't work, find a new one */
+ if (mid == begin) {
+ /* all possibilities exhausted */
+ MDEBUG(("%d no midpoint\n", t->retry));
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ mid = longest(v, d, begin, mid-1, (int *)NULL);
+ if (mid == NULL) {
+ /* failed to find a new one */
+ MDEBUG(("%d failed midpoint\n", t->retry));
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ MDEBUG(("%d: new midpoint %ld\n", t->retry, LOFF(mid)));
+ v->mem[t->retry] = (mid - begin) + 1;
+ zapmem(v, t->left);
+ zapmem(v, t->right);
+ }
+
+ /* satisfaction */
+ MDEBUG(("successful\n"));
+ freedfa(d);
+ freedfa(d2);
+ return REG_OKAY;
+}
+
+/*
+ - crevdissect - determine backref shortest-first subexpression matches
+ * The retry memory stores the offset of the trial midpoint from begin,
+ * plus 1 so that 0 uniquely means "clean slate".
+ ^ static int crevdissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+crevdissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ struct dfa *d;
+ struct dfa *d2;
+ chr *mid;
+ int er;
+
+ assert(t->op == '.');
+ assert(t->left != NULL && t->left->cnfa.nstates > 0);
+ assert(t->right != NULL && t->right->cnfa.nstates > 0);
+ assert(t->left->flags&SHORTER);
+
+ /* concatenation -- need to split the substring between parts */
+ d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC);
+ if (ISERR())
+ return v->err;
+ d2 = newdfa(v, &t->right->cnfa, &v->g->cmap, DOMALLOC);
+ if (ISERR()) {
+ freedfa(d);
+ return v->err;
+ }
+ MDEBUG(("crev %d\n", t->retry));
+
+ /* pick a tentative midpoint */
+ if (v->mem[t->retry] == 0) {
+ mid = shortest(v, d, begin, begin, end, (chr **)NULL, (int *)NULL);
+ if (mid == NULL) {
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ MDEBUG(("tentative midpoint %ld\n", LOFF(mid)));
+ v->mem[t->retry] = (mid - begin) + 1;
+ } else {
+ mid = begin + (v->mem[t->retry] - 1);
+ MDEBUG(("working midpoint %ld\n", LOFF(mid)));
+ }
+
+ /* iterate until satisfaction or failure */
+ for (;;) {
+ /* try this midpoint on for size */
+ er = cdissect(v, t->left, begin, mid);
+ if (er == REG_OKAY &&
+ longest(v, d2, mid, end, (int *)NULL) == end &&
+ (er = cdissect(v, t->right, mid, end)) ==
+ REG_OKAY)
+ break; /* NOTE BREAK OUT */
+ if (er != REG_OKAY && er != REG_NOMATCH) {
+ freedfa(d);
+ freedfa(d2);
+ return er;
+ }
+
+ /* that midpoint didn't work, find a new one */
+ if (mid == end) {
+ /* all possibilities exhausted */
+ MDEBUG(("%d no midpoint\n", t->retry));
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ mid = shortest(v, d, begin, mid+1, end, (chr **)NULL, (int *)NULL);
+ if (mid == NULL) {
+ /* failed to find a new one */
+ MDEBUG(("%d failed midpoint\n", t->retry));
+ freedfa(d);
+ freedfa(d2);
+ return REG_NOMATCH;
+ }
+ MDEBUG(("%d: new midpoint %ld\n", t->retry, LOFF(mid)));
+ v->mem[t->retry] = (mid - begin) + 1;
+ zapmem(v, t->left);
+ zapmem(v, t->right);
+ }
+
+ /* satisfaction */
+ MDEBUG(("successful\n"));
+ freedfa(d);
+ freedfa(d2);
+ return REG_OKAY;
+}
+
+/*
+ - cbrdissect - determine backref subexpression matches
+ ^ static int cbrdissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+cbrdissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ int i;
+ int n = t->subno;
+ size_t len;
+ chr *paren;
+ chr *p;
+ chr *stop;
+ int min = t->min;
+ int max = t->max;
+
+ assert(t != NULL);
+ assert(t->op == 'b');
+ assert(n >= 0);
+ assert((size_t)n < v->nmatch);
+
+ MDEBUG(("cbackref n%d %d{%d-%d}\n", t->retry, n, min, max));
+
+ if (v->pmatch[n].rm_so == -1)
+ return REG_NOMATCH;
+ paren = v->start + v->pmatch[n].rm_so;
+ len = v->pmatch[n].rm_eo - v->pmatch[n].rm_so;
+
+ /* no room to maneuver -- retries are pointless */
+ if (v->mem[t->retry])
+ return REG_NOMATCH;
+ v->mem[t->retry] = 1;
+
+ /* special-case zero-length string */
+ if (len == 0) {
+ if (begin == end)
+ return REG_OKAY;
+ return REG_NOMATCH;
+ }
+
+ /* and too-short string */
+ assert(end >= begin);
+ if ((size_t)(end - begin) < len)
+ return REG_NOMATCH;
+ stop = end - len;
+
+ /* count occurrences */
+ i = 0;
+ for (p = begin; p <= stop && (i < max || max == INFINITY); p += len) {
+ if ((*v->g->compare)(paren, p, len) != 0)
+ break;
+ i++;
+ }
+ MDEBUG(("cbackref found %d\n", i));
+
+ /* and sort it out */
+ if (p != end) /* didn't consume all of it */
+ return REG_NOMATCH;
+ if (min <= i && (i <= max || max == INFINITY))
+ return REG_OKAY;
+ return REG_NOMATCH; /* out of range */
+}
+
+/*
+ - caltdissect - determine alternative subexpression matches (w. complications)
+ ^ static int caltdissect(struct vars *, struct subre *, chr *, chr *);
+ */
+static int /* regexec return code */
+caltdissect(v, t, begin, end)
+struct vars *v;
+struct subre *t;
+chr *begin; /* beginning of relevant substring */
+chr *end; /* end of same */
+{
+ struct dfa *d;
+ int er;
+# define UNTRIED 0 /* not yet tried at all */
+# define TRYING 1 /* top matched, trying submatches */
+# define TRIED 2 /* top didn't match or submatches exhausted */
+
+ if (t == NULL)
+ return REG_NOMATCH;
+ assert(t->op == '|');
+ if (v->mem[t->retry] == TRIED)
+ return caltdissect(v, t->right, begin, end);
+
+ MDEBUG(("calt n%d\n", t->retry));
+ assert(t->left != NULL);
+
+ if (v->mem[t->retry] == UNTRIED) {
+ d = newdfa(v, &t->left->cnfa, &v->g->cmap, DOMALLOC);
+ if (ISERR())
+ return v->err;
+ if (longest(v, d, begin, end, (int *)NULL) != end) {
+ freedfa(d);
+ v->mem[t->retry] = TRIED;
+ return caltdissect(v, t->right, begin, end);
+ }
+ freedfa(d);
+ MDEBUG(("calt matched\n"));
+ v->mem[t->retry] = TRYING;
+ }
+
+ er = cdissect(v, t->left, begin, end);
+ if (er != REG_NOMATCH)
+ return er;
+
+ v->mem[t->retry] = TRIED;
+ return caltdissect(v, t->right, begin, end);
+}
+
+
+
+#include "rege_dfa.c"
projects / wxWidgets.git / blobdiff