diff options
| -rw-r--r-- | regex.c | 76 |
1 files changed, 36 insertions, 40 deletions
@@ -190,7 +190,7 @@ typedef union char_set { } char_set_t; typedef enum { - nfa_accept, nfa_reject, nfa_empty, nfa_wild, nfa_single, nfa_set + nfa_accept, nfa_empty, nfa_wild, nfa_single, nfa_set } nfa_kind_t; struct nfa_state_accept { @@ -814,14 +814,6 @@ static nfa_state_t *nfa_state_accept(void) return st; } -static nfa_state_t *nfa_state_reject(void) -{ - nfa_state_t *st = coerce(nfa_state_t *, chk_malloc(sizeof *st)); - st->a.kind = nfa_reject; - st->a.visited = 0; - return st; -} - static nfa_state_t *nfa_state_empty(nfa_state_t *t0, nfa_state_t *t1) { nfa_state_t *st = coerce(nfa_state_t *, chk_malloc(sizeof *st)); @@ -1055,9 +1047,7 @@ static nfa_t nfa_compile_regex(val exp) uw_throwf(error_s, lit("bad operator in regex syntax: ~s"), sym, nao); } } else if (exp == t) { - nfa_state_t *acc = nfa_state_accept(); - nfa_state_t *s = nfa_state_reject(); - return nfa_make(s, acc); + return nfa_make(0, 0); } else { uw_throwf(error_s, lit("bad object in regex syntax: ~s"), exp, nao); } @@ -1068,13 +1058,12 @@ static void nfa_map_states(nfa_state_t *s, mem_t *ctx), unsigned visited) { - if (s != 0 && s->a.visited != visited) { + if (s && s->a.visited != visited) { s->a.visited = visited; fun(s, ctx); switch (s->a.kind) { case nfa_accept: - case nfa_reject: break; case nfa_empty: nfa_map_states(s->e.trans0, ctx, fun, visited); @@ -1099,14 +1088,16 @@ static void nfa_count_one(nfa_state_t *s, mem_t *ctx) static int nfa_count_states(nfa_state_t *s) { int count = 0; - unsigned visited = s->a.visited + 1; - nfa_map_states(s, coerce(mem_t *, &count), nfa_count_one, visited); + if (s) { + unsigned visited = s->a.visited + 1; + nfa_map_states(s, coerce(mem_t *, &count), nfa_count_one, visited); + } return count; } static void nfa_handle_wraparound(nfa_state_t *s, unsigned *pvisited) { - if (*pvisited == UINT_MAX) { + if (s && *pvisited == UINT_MAX) { s->a.visited = UINT_MAX - 1; (void) nfa_count_states(s); s->a.visited = UINT_MAX; @@ -1249,11 +1240,13 @@ static int nfa_move_closure(nfa_state_t **stack, nfa_state_t **set, int nin, bug_unless (stackp < nstates); - mov->a.visited = visited; - stack[stackp++] = mov; - set[nout++] = mov; - if (mov->a.kind == nfa_accept) - *accept = 1; + if (mov != 0) { + mov->a.visited = visited; + stack[stackp++] = mov; + set[nout++] = mov; + if (mov->a.kind == nfa_accept) + *accept = 1; + } } } @@ -1314,18 +1307,18 @@ static int nfa_move_closure(nfa_state_t **stack, nfa_state_t **set, int nin, static cnum nfa_run(nfa_t nfa, int nstates, const wchar_t *str) { const wchar_t *last_accept_pos = 0, *ptr = str; - unsigned visited = nfa.start->a.visited + 1; + unsigned visited = nfa.start ? (nfa.start->a.visited + 1) : 0; nfa_state_t **set = coerce(nfa_state_t **, alloca(nstates * sizeof *set)); nfa_state_t **stack = coerce(nfa_state_t **, alloca(nstates * sizeof *stack)); - int nclos; + int nclos = 0; int accept = 0; nfa_handle_wraparound(nfa.start, &visited); - set[0] = nfa.start; - - nclos = nfa_closure(stack, set, 1, - nstates, visited++, &accept); + if (nfa.start) { + set[0] = nfa.start; + nclos = nfa_closure(stack, set, 1, nstates, visited++, &accept); + } if (accept) last_accept_pos = ptr; @@ -1347,7 +1340,8 @@ static cnum nfa_run(nfa_t nfa, int nstates, const wchar_t *str) break; } - nfa.start->a.visited = visited; + if (nfa.start) + nfa.start->a.visited = visited; return last_accept_pos ? last_accept_pos - str : -1; } @@ -2351,16 +2345,17 @@ static void regex_machine_reset(regex_machine_t *regm) if (regm->n.is_nfa) { nfa_state_t *s = regm->n.nfa.start; - regm->n.visited = regm->n.nfa.start->a.visited + 1; - nfa_handle_wraparound(s, ®m->n.visited); - - regm->n.set[0] = regm->n.nfa.start; - - regm->n.nclos = nfa_closure(regm->n.stack, regm->n.set, 1, - regm->n.nstates, - regm->n.visited++, &accept); - - regm->n.nfa.start->a.visited = regm->n.visited; + if (s) { + regm->n.visited = s->a.visited + 1; + nfa_handle_wraparound(s, ®m->n.visited); + regm->n.set[0] = s; + regm->n.nclos = nfa_closure(regm->n.stack, regm->n.set, 1, + regm->n.nstates, + regm->n.visited++, &accept); + s->a.visited = regm->n.visited; + } else { + regm->n.nclos = 0; + } } else { regm->d.deriv = regm->d.regex; accept = (reg_nullable(regm->d.regex) != nil); @@ -2418,7 +2413,8 @@ static regm_result_t regex_machine_feed(regex_machine_t *regm, wchar_t ch) regm->n.nstates, ch, regm->n.visited++, &accept); - regm->n.nfa.start->a.visited = regm->n.visited; + if (regm->n.nfa.start) + regm->n.nfa.start->a.visited = regm->n.visited; if (accept) { regm->n.last_accept_pos = regm->n.count; |