diff options
Diffstat (limited to 'lib/regexec.c')
| -rw-r--r-- | lib/regexec.c | 123 |
1 files changed, 104 insertions, 19 deletions
diff --git a/lib/regexec.c b/lib/regexec.c index c84ce1ef339..ff62ac08ef1 100644 --- a/lib/regexec.c +++ b/lib/regexec.c @@ -627,6 +627,8 @@ re_search_internal (const regex_t *preg, const char *string, Idx length, /* We must check the longest matching, if nmatch > 0. */ fl_longest_match = (nmatch != 0 || dfa->nbackref); + re_dfastate_t **save_state_log = NULL; + err = re_string_allocate (&mctx.input, string, length, dfa->nodes_len + 1, preg->translate, (preg->syntax & RE_ICASE) != 0, dfa); @@ -802,11 +804,32 @@ re_search_internal (const regex_t *preg, const char *string, Idx length, if ((!preg->no_sub && nmatch > 1 && dfa->has_plural_match) || dfa->nbackref) { + /* Save state_log before pruning, in case set_regs + later fails and we need to retry with a shorter + match. */ + re_free (save_state_log); + save_state_log = NULL; + if (!preg->no_sub && nmatch > 1 && dfa->nbackref) + { + save_state_log + = re_malloc (re_dfastate_t *, + mctx.match_last + 1); + if (__glibc_unlikely (save_state_log == NULL)) + { + err = REG_ESPACE; + goto free_return; + } + memcpy (save_state_log, mctx.state_log, + sizeof (re_dfastate_t *) + * (mctx.match_last + 1)); + } err = prune_impossible_nodes (&mctx); if (err == REG_NOERROR) break; if (__glibc_unlikely (err != REG_NOMATCH)) goto free_return; + re_free (save_state_log); + save_state_log = NULL; match_last = -1; } else @@ -825,24 +848,79 @@ re_search_internal (const regex_t *preg, const char *string, Idx length, { Idx reg_idx; - /* Initialize registers. */ - for (reg_idx = 1; reg_idx < nmatch; ++reg_idx) - pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1; + /* When set_regs fails for a backref pattern, the structural + match at match_last has no valid register assignment. Try + shorter match lengths, since a valid shorter match may + exist (e.g., all groups matching empty). */ + for (;;) + { + /* Initialize registers. */ + for (reg_idx = 1; reg_idx < nmatch; ++reg_idx) + pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1; + pmatch[0].rm_so = 0; + pmatch[0].rm_eo = mctx.match_last; - /* Set the points where matching start/end. */ - pmatch[0].rm_so = 0; - pmatch[0].rm_eo = mctx.match_last; - /* FIXME: This function should fail if mctx.match_last exceeds - the maximum possible regoff_t value. We need a new error - code REG_OVERFLOW. */ + if (preg->no_sub || nmatch <= 1) + break; - if (!preg->no_sub && nmatch > 1) - { err = set_regs (preg, &mctx, nmatch, pmatch, dfa->has_plural_match && dfa->nbackref > 0); + if (__glibc_likely (err == REG_NOERROR) + || save_state_log == NULL + || err != REG_NOMATCH) + break; + + /* set_regs failed; try a shorter match_last. */ + Idx ml = mctx.match_last; + re_free (mctx.state_log); + do + { + --ml; + if (ml < 0) + break; + } + while (save_state_log[ml] == NULL + || !save_state_log[ml]->halt + || !check_halt_state_context + (&mctx, save_state_log[ml], ml)); + if (ml < 0) + { + err = REG_NOMATCH; + mctx.state_log = save_state_log; + save_state_log = NULL; + break; + } + mctx.state_log + = re_malloc (re_dfastate_t *, ml + 1); + if (__glibc_unlikely (mctx.state_log == NULL)) + { + mctx.state_log = save_state_log; + save_state_log = NULL; + err = REG_ESPACE; + break; + } + memcpy (mctx.state_log, save_state_log, + sizeof (re_dfastate_t *) * (ml + 1)); + mctx.match_last = ml; + mctx.last_node + = check_halt_state_context + (&mctx, save_state_log[ml], ml); + err = prune_impossible_nodes (&mctx); if (__glibc_unlikely (err != REG_NOERROR)) - goto free_return; + { + if (err == REG_NOMATCH) + { + re_free (mctx.state_log); + mctx.state_log = save_state_log; + save_state_log = NULL; + } + break; + } } + re_free (save_state_log); + save_state_log = NULL; + if (__glibc_unlikely (err != REG_NOERROR)) + goto free_return; /* At last, add the offset to each register, since we slid the buffers so that we could assume that the matching starts @@ -882,6 +960,7 @@ re_search_internal (const regex_t *preg, const char *string, Idx length, } free_return: + re_free (save_state_log); re_free (mctx.state_log); if (dfa->nbackref) match_ctx_free (&mctx); @@ -934,7 +1013,7 @@ prune_impossible_nodes (re_match_context_t *mctx) goto free_return; if (sifted_states[0] != NULL || lim_states[0] != NULL) break; - do + for (;;) { --match_last; if (match_last < 0) @@ -942,11 +1021,17 @@ prune_impossible_nodes (re_match_context_t *mctx) ret = REG_NOMATCH; goto free_return; } - } while (mctx->state_log[match_last] == NULL - || !mctx->state_log[match_last]->halt); - halt_node = check_halt_state_context (mctx, - mctx->state_log[match_last], - match_last); + if (mctx->state_log[match_last] != NULL + && mctx->state_log[match_last]->halt) + { + halt_node + = check_halt_state_context (mctx, + mctx->state_log[match_last], + match_last); + if (halt_node) + break; + } + } } ret = merge_state_array (dfa, sifted_states, lim_states, match_last + 1); @@ -2256,7 +2341,7 @@ merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx, mctx->state_log[cur_idx] = next_state; mctx->state_log_top = cur_idx; } - else if (mctx->state_log[cur_idx] == 0) + else if (mctx->state_log[cur_idx] == NULL) { mctx->state_log[cur_idx] = next_state; } |