| /* Extended regular expression matching and search library. |
| Copyright (C) 2002-2005, 2007, 2009, 2010 Free Software Foundation, Inc. |
| This file is part of the GNU C Library. |
| Contributed by Isamu Hasegawa <isamu@yamato.ibm.com>. |
| |
| The GNU C Library is free software; you can redistribute it and/or |
| modify it under the terms of the GNU Lesser General Public |
| License as published by the Free Software Foundation; either |
| version 2.1 of the License, or (at your option) any later version. |
| |
| The GNU C Library is distributed in the hope that it will be useful, |
| but WITHOUT ANY WARRANTY; without even the implied warranty of |
| MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| Lesser General Public License for more details. |
| |
| You should have received a copy of the GNU Lesser General Public |
| License along with the GNU C Library; if not, see |
| <http://www.gnu.org/licenses/>. */ |
| |
| static reg_errcode_t match_ctx_init (re_match_context_t *cache, int eflags, |
| int n) internal_function; |
| static void match_ctx_clean (re_match_context_t *mctx) internal_function; |
| static void match_ctx_free (re_match_context_t *cache) internal_function; |
| static reg_errcode_t match_ctx_add_entry (re_match_context_t *cache, int node, |
| int str_idx, int from, int to) |
| internal_function; |
| static int search_cur_bkref_entry (const re_match_context_t *mctx, int str_idx) |
| internal_function; |
| static reg_errcode_t match_ctx_add_subtop (re_match_context_t *mctx, int node, |
| int str_idx) internal_function; |
| static re_sub_match_last_t * match_ctx_add_sublast (re_sub_match_top_t *subtop, |
| int node, int str_idx) |
| internal_function; |
| static void sift_ctx_init (re_sift_context_t *sctx, re_dfastate_t **sifted_sts, |
| re_dfastate_t **limited_sts, int last_node, |
| int last_str_idx) |
| internal_function; |
| static reg_errcode_t re_search_internal (const regex_t *preg, |
| const char *string, int length, |
| int start, int range, int stop, |
| size_t nmatch, regmatch_t pmatch[], |
| int eflags); |
| static int re_search_2_stub (struct re_pattern_buffer *bufp, |
| const char *string1, int length1, |
| const char *string2, int length2, |
| int start, int range, struct re_registers *regs, |
| int stop, int ret_len); |
| static int re_search_stub (struct re_pattern_buffer *bufp, |
| const char *string, int length, int start, |
| int range, int stop, struct re_registers *regs, |
| int ret_len); |
| static unsigned re_copy_regs (struct re_registers *regs, regmatch_t *pmatch, |
| int nregs, int regs_allocated); |
| static reg_errcode_t prune_impossible_nodes (re_match_context_t *mctx); |
| static int check_matching (re_match_context_t *mctx, int fl_longest_match, |
| int *p_match_first) internal_function; |
| static int check_halt_state_context (const re_match_context_t *mctx, |
| const re_dfastate_t *state, int idx) |
| internal_function; |
| static void update_regs (const re_dfa_t *dfa, regmatch_t *pmatch, |
| regmatch_t *prev_idx_match, int cur_node, |
| int cur_idx, int nmatch) internal_function; |
| static reg_errcode_t push_fail_stack (struct re_fail_stack_t *fs, |
| int str_idx, int dest_node, int nregs, |
| regmatch_t *regs, |
| re_node_set *eps_via_nodes) |
| internal_function; |
| static reg_errcode_t set_regs (const regex_t *preg, |
| const re_match_context_t *mctx, |
| size_t nmatch, regmatch_t *pmatch, |
| int fl_backtrack) internal_function; |
| static reg_errcode_t free_fail_stack_return (struct re_fail_stack_t *fs) |
| internal_function; |
| |
| #ifdef RE_ENABLE_I18N |
| static int sift_states_iter_mb (const re_match_context_t *mctx, |
| re_sift_context_t *sctx, |
| int node_idx, int str_idx, int max_str_idx) |
| internal_function; |
| #endif /* RE_ENABLE_I18N */ |
| static reg_errcode_t sift_states_backward (const re_match_context_t *mctx, |
| re_sift_context_t *sctx) |
| internal_function; |
| static reg_errcode_t build_sifted_states (const re_match_context_t *mctx, |
| re_sift_context_t *sctx, int str_idx, |
| re_node_set *cur_dest) |
| internal_function; |
| static reg_errcode_t update_cur_sifted_state (const re_match_context_t *mctx, |
| re_sift_context_t *sctx, |
| int str_idx, |
| re_node_set *dest_nodes) |
| internal_function; |
| static reg_errcode_t add_epsilon_src_nodes (const re_dfa_t *dfa, |
| re_node_set *dest_nodes, |
| const re_node_set *candidates) |
| internal_function; |
| static int check_dst_limits (const re_match_context_t *mctx, |
| re_node_set *limits, |
| int dst_node, int dst_idx, int src_node, |
| int src_idx) internal_function; |
| static int check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, |
| int boundaries, int subexp_idx, |
| int from_node, int bkref_idx) |
| internal_function; |
| static int check_dst_limits_calc_pos (const re_match_context_t *mctx, |
| int limit, int subexp_idx, |
| int node, int str_idx, |
| int bkref_idx) internal_function; |
| static reg_errcode_t check_subexp_limits (const re_dfa_t *dfa, |
| re_node_set *dest_nodes, |
| const re_node_set *candidates, |
| re_node_set *limits, |
| struct re_backref_cache_entry *bkref_ents, |
| int str_idx) internal_function; |
| static reg_errcode_t sift_states_bkref (const re_match_context_t *mctx, |
| re_sift_context_t *sctx, |
| int str_idx, const re_node_set *candidates) |
| internal_function; |
| static reg_errcode_t merge_state_array (const re_dfa_t *dfa, |
| re_dfastate_t **dst, |
| re_dfastate_t **src, int num) |
| internal_function; |
| static re_dfastate_t *find_recover_state (reg_errcode_t *err, |
| re_match_context_t *mctx) internal_function; |
| static re_dfastate_t *transit_state (reg_errcode_t *err, |
| re_match_context_t *mctx, |
| re_dfastate_t *state) internal_function; |
| static re_dfastate_t *merge_state_with_log (reg_errcode_t *err, |
| re_match_context_t *mctx, |
| re_dfastate_t *next_state) |
| internal_function; |
| static reg_errcode_t check_subexp_matching_top (re_match_context_t *mctx, |
| re_node_set *cur_nodes, |
| int str_idx) internal_function; |
| #if 0 |
| static re_dfastate_t *transit_state_sb (reg_errcode_t *err, |
| re_match_context_t *mctx, |
| re_dfastate_t *pstate) |
| internal_function; |
| #endif |
| #ifdef RE_ENABLE_I18N |
| static reg_errcode_t transit_state_mb (re_match_context_t *mctx, |
| re_dfastate_t *pstate) |
| internal_function; |
| #endif /* RE_ENABLE_I18N */ |
| static reg_errcode_t transit_state_bkref (re_match_context_t *mctx, |
| const re_node_set *nodes) |
| internal_function; |
| static reg_errcode_t get_subexp (re_match_context_t *mctx, |
| int bkref_node, int bkref_str_idx) |
| internal_function; |
| static reg_errcode_t get_subexp_sub (re_match_context_t *mctx, |
| const re_sub_match_top_t *sub_top, |
| re_sub_match_last_t *sub_last, |
| int bkref_node, int bkref_str) |
| internal_function; |
| static int find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes, |
| int subexp_idx, int type) internal_function; |
| static reg_errcode_t check_arrival (re_match_context_t *mctx, |
| state_array_t *path, int top_node, |
| int top_str, int last_node, int last_str, |
| int type) internal_function; |
| static reg_errcode_t check_arrival_add_next_nodes (re_match_context_t *mctx, |
| int str_idx, |
| re_node_set *cur_nodes, |
| re_node_set *next_nodes) |
| internal_function; |
| static reg_errcode_t check_arrival_expand_ecl (const re_dfa_t *dfa, |
| re_node_set *cur_nodes, |
| int ex_subexp, int type) |
| internal_function; |
| static reg_errcode_t check_arrival_expand_ecl_sub (const re_dfa_t *dfa, |
| re_node_set *dst_nodes, |
| int target, int ex_subexp, |
| int type) internal_function; |
| static reg_errcode_t expand_bkref_cache (re_match_context_t *mctx, |
| re_node_set *cur_nodes, int cur_str, |
| int subexp_num, int type) |
| internal_function; |
| static int build_trtable (const re_dfa_t *dfa, |
| re_dfastate_t *state) internal_function; |
| #ifdef RE_ENABLE_I18N |
| static int check_node_accept_bytes (const re_dfa_t *dfa, int node_idx, |
| const re_string_t *input, int idx) |
| internal_function; |
| # ifdef _LIBC |
| static unsigned int find_collation_sequence_value (const unsigned char *mbs, |
| size_t name_len) |
| internal_function; |
| # endif /* _LIBC */ |
| #endif /* RE_ENABLE_I18N */ |
| static int group_nodes_into_DFAstates (const re_dfa_t *dfa, |
| const re_dfastate_t *state, |
| re_node_set *states_node, |
| bitset_t *states_ch) internal_function; |
| static int check_node_accept (const re_match_context_t *mctx, |
| const re_token_t *node, int idx) |
| internal_function; |
| static reg_errcode_t extend_buffers (re_match_context_t *mctx) |
| internal_function; |
| |
| /* Entry point for POSIX code. */ |
| |
| /* regexec searches for a given pattern, specified by PREG, in the |
| string STRING. |
| |
| If NMATCH is zero or REG_NOSUB was set in the cflags argument to |
| `regcomp', we ignore PMATCH. Otherwise, we assume PMATCH has at |
| least NMATCH elements, and we set them to the offsets of the |
| corresponding matched substrings. |
| |
| EFLAGS specifies `execution flags' which affect matching: if |
| REG_NOTBOL is set, then ^ does not match at the beginning of the |
| string; if REG_NOTEOL is set, then $ does not match at the end. |
| |
| We return 0 if we find a match and REG_NOMATCH if not. */ |
| |
| int |
| regexec ( |
| const regex_t *__restrict preg, |
| const char *__restrict string, |
| size_t nmatch, |
| regmatch_t pmatch[], |
| int eflags) |
| { |
| reg_errcode_t err; |
| int start, length; |
| |
| if (eflags & ~(REG_NOTBOL | REG_NOTEOL | REG_STARTEND)) |
| return REG_BADPAT; |
| |
| if (eflags & REG_STARTEND) |
| { |
| start = pmatch[0].rm_so; |
| length = pmatch[0].rm_eo; |
| } |
| else |
| { |
| start = 0; |
| length = strlen (string); |
| } |
| |
| __libc_lock_lock (dfa->lock); |
| if (preg->no_sub) |
| err = re_search_internal (preg, string, length, start, length - start, |
| length, 0, NULL, eflags); |
| else |
| err = re_search_internal (preg, string, length, start, length - start, |
| length, nmatch, pmatch, eflags); |
| __libc_lock_unlock (dfa->lock); |
| return err != REG_NOERROR; |
| } |
| |
| #ifdef _LIBC |
| # include <shlib-compat.h> |
| versioned_symbol (libc, __regexec, regexec, GLIBC_2_3_4); |
| |
| # if SHLIB_COMPAT (libc, GLIBC_2_0, GLIBC_2_3_4) |
| __typeof__ (__regexec) __compat_regexec; |
| |
| int |
| attribute_compat_text_section |
| __compat_regexec (const regex_t *__restrict preg, |
| const char *__restrict string, size_t nmatch, |
| regmatch_t pmatch[], int eflags) |
| { |
| return regexec (preg, string, nmatch, pmatch, |
| eflags & (REG_NOTBOL | REG_NOTEOL)); |
| } |
| compat_symbol (libc, __compat_regexec, regexec, GLIBC_2_0); |
| # endif |
| #endif |
| |
| /* Entry points for GNU code. */ |
| |
| /* re_match, re_search, re_match_2, re_search_2 |
| |
| The former two functions operate on STRING with length LENGTH, |
| while the later two operate on concatenation of STRING1 and STRING2 |
| with lengths LENGTH1 and LENGTH2, respectively. |
| |
| re_match() matches the compiled pattern in BUFP against the string, |
| starting at index START. |
| |
| re_search() first tries matching at index START, then it tries to match |
| starting from index START + 1, and so on. The last start position tried |
| is START + RANGE. (Thus RANGE = 0 forces re_search to operate the same |
| way as re_match().) |
| |
| The parameter STOP of re_{match,search}_2 specifies that no match exceeding |
| the first STOP characters of the concatenation of the strings should be |
| concerned. |
| |
| If REGS is not NULL, and BUFP->no_sub is not set, the offsets of the match |
| and all groups is stroed in REGS. (For the "_2" variants, the offsets are |
| computed relative to the concatenation, not relative to the individual |
| strings.) |
| |
| On success, re_match* functions return the length of the match, re_search* |
| return the position of the start of the match. Return value -1 means no |
| match was found and -2 indicates an internal error. */ |
| |
| int |
| re_match (struct re_pattern_buffer *bufp, |
| const char *string, |
| int length, |
| int start, |
| struct re_registers *regs) |
| { |
| return re_search_stub (bufp, string, length, start, 0, length, regs, 1); |
| } |
| #ifdef _LIBC |
| weak_alias (__re_match, re_match) |
| #endif |
| |
| int |
| re_search (struct re_pattern_buffer *bufp, |
| const char *string, |
| int length, int start, int range, |
| struct re_registers *regs) |
| { |
| return re_search_stub (bufp, string, length, start, range, length, regs, 0); |
| } |
| #ifdef _LIBC |
| weak_alias (__re_search, re_search) |
| #endif |
| |
| int |
| re_match_2 (struct re_pattern_buffer *bufp, |
| const char *string1, int length1, |
| const char *string2, int length2, int start, |
| struct re_registers *regs, int stop) |
| { |
| return re_search_2_stub (bufp, string1, length1, string2, length2, |
| start, 0, regs, stop, 1); |
| } |
| #ifdef _LIBC |
| weak_alias (__re_match_2, re_match_2) |
| #endif |
| |
| int |
| re_search_2 (struct re_pattern_buffer *bufp, |
| const char *string1, int length1, |
| const char *string2, int length2, int start, |
| int range, struct re_registers *regs, int stop) |
| { |
| return re_search_2_stub (bufp, string1, length1, string2, length2, |
| start, range, regs, stop, 0); |
| } |
| #ifdef _LIBC |
| weak_alias (__re_search_2, re_search_2) |
| #endif |
| |
| static int |
| re_search_2_stub (struct re_pattern_buffer *bufp, |
| const char *string1, int length1, |
| const char *string2, int length2, int start, |
| int range, struct re_registers *regs, |
| int stop, int ret_len) |
| { |
| const char *str; |
| int rval; |
| int len = length1 + length2; |
| int free_str = 0; |
| |
| if (BE (length1 < 0 || length2 < 0 || stop < 0, 0)) |
| return -2; |
| |
| /* Concatenate the strings. */ |
| if (length2 > 0) |
| if (length1 > 0) |
| { |
| char *s = re_malloc (char, len); |
| |
| if (BE (s == NULL, 0)) |
| return -2; |
| memcpy (s, string1, length1); |
| memcpy (s + length1, string2, length2); |
| str = s; |
| free_str = 1; |
| } |
| else |
| str = string2; |
| else |
| str = string1; |
| |
| rval = re_search_stub (bufp, str, len, start, range, stop, regs, ret_len); |
| if (free_str) |
| re_free ((char *) str); |
| return rval; |
| } |
| |
| /* The parameters have the same meaning as those of re_search. |
| Additional parameters: |
| If RET_LEN is nonzero the length of the match is returned (re_match style); |
| otherwise the position of the match is returned. */ |
| |
| static int |
| re_search_stub (struct re_pattern_buffer *bufp, |
| const char *string, int length, int start, |
| int range, int stop, |
| struct re_registers *regs, int ret_len) |
| { |
| reg_errcode_t result; |
| regmatch_t *pmatch; |
| int nregs, rval; |
| int eflags = 0; |
| |
| /* Check for out-of-range. */ |
| if (BE (start < 0 || start > length, 0)) |
| return -1; |
| if (BE (start + range > length, 0)) |
| range = length - start; |
| else if (BE (start + range < 0, 0)) |
| range = -start; |
| |
| __libc_lock_lock (dfa->lock); |
| |
| eflags |= (bufp->not_bol) ? REG_NOTBOL : 0; |
| eflags |= (bufp->not_eol) ? REG_NOTEOL : 0; |
| |
| /* Compile fastmap if we haven't yet. */ |
| if (range > 0 && bufp->fastmap != NULL && !bufp->fastmap_accurate) |
| re_compile_fastmap (bufp); |
| |
| if (BE (bufp->no_sub, 0)) |
| regs = NULL; |
| |
| /* We need at least 1 register. */ |
| if (regs == NULL) |
| nregs = 1; |
| else if (BE (bufp->regs_allocated == REGS_FIXED && |
| regs->num_regs < bufp->re_nsub + 1, 0)) |
| { |
| nregs = regs->num_regs; |
| if (BE (nregs < 1, 0)) |
| { |
| /* Nothing can be copied to regs. */ |
| regs = NULL; |
| nregs = 1; |
| } |
| } |
| else |
| nregs = bufp->re_nsub + 1; |
| pmatch = re_malloc (regmatch_t, nregs); |
| if (BE (pmatch == NULL, 0)) |
| { |
| rval = -2; |
| goto out; |
| } |
| |
| result = re_search_internal (bufp, string, length, start, range, stop, |
| nregs, pmatch, eflags); |
| |
| rval = 0; |
| |
| /* I hope we needn't fill their regs with -1's when no match was found. */ |
| if (result != REG_NOERROR) |
| rval = -1; |
| else if (regs != NULL) |
| { |
| /* If caller wants register contents data back, copy them. */ |
| bufp->regs_allocated = re_copy_regs (regs, pmatch, nregs, |
| bufp->regs_allocated); |
| if (BE (bufp->regs_allocated == REGS_UNALLOCATED, 0)) |
| rval = -2; |
| } |
| |
| if (BE (rval == 0, 1)) |
| { |
| if (ret_len) |
| { |
| assert (pmatch[0].rm_so == start); |
| rval = pmatch[0].rm_eo - start; |
| } |
| else |
| rval = pmatch[0].rm_so; |
| } |
| re_free (pmatch); |
| out: |
| __libc_lock_unlock (dfa->lock); |
| return rval; |
| } |
| |
| static unsigned |
| re_copy_regs (struct re_registers *regs, |
| regmatch_t *pmatch, |
| int nregs, int regs_allocated) |
| { |
| int rval = REGS_REALLOCATE; |
| int i; |
| int need_regs = nregs + 1; |
| /* We need one extra element beyond `num_regs' for the `-1' marker GNU code |
| uses. */ |
| |
| /* Have the register data arrays been allocated? */ |
| if (regs_allocated == REGS_UNALLOCATED) |
| { /* No. So allocate them with malloc. */ |
| regs->start = re_malloc (regoff_t, need_regs); |
| if (BE (regs->start == NULL, 0)) |
| return REGS_UNALLOCATED; |
| regs->end = re_malloc (regoff_t, need_regs); |
| if (BE (regs->end == NULL, 0)) |
| { |
| re_free (regs->start); |
| return REGS_UNALLOCATED; |
| } |
| regs->num_regs = need_regs; |
| } |
| else if (regs_allocated == REGS_REALLOCATE) |
| { /* Yes. If we need more elements than were already |
| allocated, reallocate them. If we need fewer, just |
| leave it alone. */ |
| if (BE (need_regs > regs->num_regs, 0)) |
| { |
| regoff_t *new_start = re_realloc (regs->start, regoff_t, need_regs); |
| regoff_t *new_end; |
| if (BE (new_start == NULL, 0)) |
| return REGS_UNALLOCATED; |
| new_end = re_realloc (regs->end, regoff_t, need_regs); |
| if (BE (new_end == NULL, 0)) |
| { |
| re_free (new_start); |
| return REGS_UNALLOCATED; |
| } |
| regs->start = new_start; |
| regs->end = new_end; |
| regs->num_regs = need_regs; |
| } |
| } |
| else |
| { |
| assert (regs_allocated == REGS_FIXED); |
| /* This function may not be called with REGS_FIXED and nregs too big. */ |
| assert (regs->num_regs >= nregs); |
| rval = REGS_FIXED; |
| } |
| |
| /* Copy the regs. */ |
| for (i = 0; i < nregs; ++i) |
| { |
| regs->start[i] = pmatch[i].rm_so; |
| regs->end[i] = pmatch[i].rm_eo; |
| } |
| for ( ; i < regs->num_regs; ++i) |
| regs->start[i] = regs->end[i] = -1; |
| |
| return rval; |
| } |
| |
| /* Set REGS to hold NUM_REGS registers, storing them in STARTS and |
| ENDS. Subsequent matches using PATTERN_BUFFER and REGS will use |
| this memory for recording register information. STARTS and ENDS |
| must be allocated using the malloc library routine, and must each |
| be at least NUM_REGS * sizeof (regoff_t) bytes long. |
| |
| If NUM_REGS == 0, then subsequent matches should allocate their own |
| register data. |
| |
| Unless this function is called, the first search or match using |
| PATTERN_BUFFER will allocate its own register data, without |
| freeing the old data. */ |
| |
| void |
| re_set_registers (struct re_pattern_buffer *bufp, |
| struct re_registers *regs, |
| unsigned num_regs, |
| regoff_t *starts, |
| regoff_t *ends) |
| { |
| if (num_regs) |
| { |
| bufp->regs_allocated = REGS_REALLOCATE; |
| regs->num_regs = num_regs; |
| regs->start = starts; |
| regs->end = ends; |
| } |
| else |
| { |
| bufp->regs_allocated = REGS_UNALLOCATED; |
| regs->num_regs = 0; |
| regs->start = regs->end = (regoff_t *) 0; |
| } |
| } |
| #ifdef _LIBC |
| weak_alias (__re_set_registers, re_set_registers) |
| #endif |
| |
| /* Entry points compatible with 4.2 BSD regex library. We don't define |
| them unless specifically requested. */ |
| |
| #if defined _REGEX_RE_COMP || defined _LIBC |
| int |
| # ifdef _LIBC |
| weak_function |
| # endif |
| re_exec (s) |
| const char *s; |
| { |
| return 0 == regexec (&re_comp_buf, s, 0, NULL, 0); |
| } |
| #endif /* _REGEX_RE_COMP */ |
| |
| /* Internal entry point. */ |
| |
| /* Searches for a compiled pattern PREG in the string STRING, whose |
| length is LENGTH. NMATCH, PMATCH, and EFLAGS have the same |
| mingings with regexec. START, and RANGE have the same meanings |
| with re_search. |
| Return REG_NOERROR if we find a match, and REG_NOMATCH if not, |
| otherwise return the error code. |
| Note: We assume front end functions already check ranges. |
| (START + RANGE >= 0 && START + RANGE <= LENGTH) */ |
| |
| static reg_errcode_t |
| re_search_internal (const regex_t *preg, |
| const char *string, |
| int length, int start, int range, int stop, |
| size_t nmatch, regmatch_t pmatch[], |
| int eflags) |
| { |
| reg_errcode_t err; |
| const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer; |
| int left_lim, right_lim, incr; |
| int fl_longest_match, match_first, match_kind, match_last = -1; |
| int extra_nmatch; |
| int sb, ch; |
| #if defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L) |
| re_match_context_t mctx = { .dfa = dfa }; |
| #else |
| re_match_context_t mctx; |
| #endif |
| char *fastmap = (preg->fastmap != NULL && preg->fastmap_accurate |
| && range && !preg->can_be_null) ? preg->fastmap : NULL; |
| RE_TRANSLATE_TYPE t = preg->translate; |
| |
| #if !(defined _LIBC || (defined __STDC_VERSION__ && __STDC_VERSION__ >= 199901L)) |
| memset (&mctx, '\0', sizeof (re_match_context_t)); |
| mctx.dfa = dfa; |
| #endif |
| |
| extra_nmatch = (nmatch > preg->re_nsub) ? nmatch - (preg->re_nsub + 1) : 0; |
| nmatch -= extra_nmatch; |
| |
| /* Check if the DFA haven't been compiled. */ |
| if (BE (preg->used == 0 || dfa->init_state == NULL |
| || dfa->init_state_word == NULL || dfa->init_state_nl == NULL |
| || dfa->init_state_begbuf == NULL, 0)) |
| return REG_NOMATCH; |
| |
| #ifdef DEBUG |
| /* We assume front-end functions already check them. */ |
| assert (start + range >= 0 && start + range <= length); |
| #endif |
| |
| /* If initial states with non-begbuf contexts have no elements, |
| the regex must be anchored. If preg->newline_anchor is set, |
| we'll never use init_state_nl, so do not check it. */ |
| if (dfa->init_state->nodes.nelem == 0 |
| && dfa->init_state_word->nodes.nelem == 0 |
| && (dfa->init_state_nl->nodes.nelem == 0 |
| || !preg->newline_anchor)) |
| { |
| if (start != 0 && start + range != 0) |
| return REG_NOMATCH; |
| start = range = 0; |
| } |
| |
| /* We must check the longest matching, if nmatch > 0. */ |
| fl_longest_match = (nmatch != 0 || dfa->nbackref); |
| |
| err = re_string_allocate (&mctx.input, string, length, dfa->nodes_len + 1, |
| preg->translate, preg->syntax & RE_ICASE, dfa); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| mctx.input.stop = stop; |
| mctx.input.raw_stop = stop; |
| mctx.input.newline_anchor = preg->newline_anchor; |
| |
| err = match_ctx_init (&mctx, eflags, dfa->nbackref * 2); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| |
| /* We will log all the DFA states through which the dfa pass, |
| if nmatch > 1, or this dfa has "multibyte node", which is a |
| back-reference or a node which can accept multibyte character or |
| multi character collating element. */ |
| if (nmatch > 1 || dfa->has_mb_node) |
| { |
| /* Avoid overflow. */ |
| if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= mctx.input.bufs_len, 0)) |
| { |
| err = REG_ESPACE; |
| goto free_return; |
| } |
| |
| mctx.state_log = re_malloc (re_dfastate_t *, mctx.input.bufs_len + 1); |
| if (BE (mctx.state_log == NULL, 0)) |
| { |
| err = REG_ESPACE; |
| goto free_return; |
| } |
| } |
| else |
| mctx.state_log = NULL; |
| |
| match_first = start; |
| mctx.input.tip_context = (eflags & REG_NOTBOL) ? CONTEXT_BEGBUF |
| : CONTEXT_NEWLINE | CONTEXT_BEGBUF; |
| |
| /* Check incrementally whether of not the input string match. */ |
| incr = (range < 0) ? -1 : 1; |
| left_lim = (range < 0) ? start + range : start; |
| right_lim = (range < 0) ? start : start + range; |
| sb = dfa->mb_cur_max == 1; |
| match_kind = |
| (fastmap |
| ? ((sb || !(preg->syntax & RE_ICASE || t) ? 4 : 0) |
| | (range >= 0 ? 2 : 0) |
| | (t != NULL ? 1 : 0)) |
| : 8); |
| |
| for (;; match_first += incr) |
| { |
| err = REG_NOMATCH; |
| if (match_first < left_lim || right_lim < match_first) |
| goto free_return; |
| |
| /* Advance as rapidly as possible through the string, until we |
| find a plausible place to start matching. This may be done |
| with varying efficiency, so there are various possibilities: |
| only the most common of them are specialized, in order to |
| save on code size. We use a switch statement for speed. */ |
| switch (match_kind) |
| { |
| case 8: |
| /* No fastmap. */ |
| break; |
| |
| case 7: |
| /* Fastmap with single-byte translation, match forward. */ |
| while (BE (match_first < right_lim, 1) |
| && !fastmap[t[(unsigned char) string[match_first]]]) |
| ++match_first; |
| goto forward_match_found_start_or_reached_end; |
| |
| case 6: |
| /* Fastmap without translation, match forward. */ |
| while (BE (match_first < right_lim, 1) |
| && !fastmap[(unsigned char) string[match_first]]) |
| ++match_first; |
| |
| forward_match_found_start_or_reached_end: |
| if (BE (match_first == right_lim, 0)) |
| { |
| ch = match_first >= length |
| ? 0 : (unsigned char) string[match_first]; |
| if (!fastmap[t ? t[ch] : ch]) |
| goto free_return; |
| } |
| break; |
| |
| case 4: |
| case 5: |
| /* Fastmap without multi-byte translation, match backwards. */ |
| while (match_first >= left_lim) |
| { |
| ch = match_first >= length |
| ? 0 : (unsigned char) string[match_first]; |
| if (fastmap[t ? t[ch] : ch]) |
| break; |
| --match_first; |
| } |
| if (match_first < left_lim) |
| goto free_return; |
| break; |
| |
| default: |
| /* In this case, we can't determine easily the current byte, |
| since it might be a component byte of a multibyte |
| character. Then we use the constructed buffer instead. */ |
| for (;;) |
| { |
| /* If MATCH_FIRST is out of the valid range, reconstruct the |
| buffers. */ |
| unsigned int offset = match_first - mctx.input.raw_mbs_idx; |
| if (BE (offset >= (unsigned int) mctx.input.valid_raw_len, 0)) |
| { |
| err = re_string_reconstruct (&mctx.input, match_first, |
| eflags); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| |
| offset = match_first - mctx.input.raw_mbs_idx; |
| } |
| /* If MATCH_FIRST is out of the buffer, leave it as '\0'. |
| Note that MATCH_FIRST must not be smaller than 0. */ |
| ch = (match_first >= length |
| ? 0 : re_string_byte_at (&mctx.input, offset)); |
| if (fastmap[ch]) |
| break; |
| match_first += incr; |
| if (match_first < left_lim || match_first > right_lim) |
| { |
| err = REG_NOMATCH; |
| goto free_return; |
| } |
| } |
| break; |
| } |
| |
| /* Reconstruct the buffers so that the matcher can assume that |
| the matching starts from the beginning of the buffer. */ |
| err = re_string_reconstruct (&mctx.input, match_first, eflags); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| |
| #ifdef RE_ENABLE_I18N |
| /* Don't consider this char as a possible match start if it part, |
| yet isn't the head, of a multibyte character. */ |
| if (!sb && !re_string_first_byte (&mctx.input, 0)) |
| continue; |
| #endif |
| |
| /* It seems to be appropriate one, then use the matcher. */ |
| /* We assume that the matching starts from 0. */ |
| mctx.state_log_top = mctx.nbkref_ents = mctx.max_mb_elem_len = 0; |
| match_last = check_matching (&mctx, fl_longest_match, |
| range >= 0 ? &match_first : NULL); |
| if (match_last != -1) |
| { |
| if (BE (match_last == -2, 0)) |
| { |
| err = REG_ESPACE; |
| goto free_return; |
| } |
| else |
| { |
| mctx.match_last = match_last; |
| if ((!preg->no_sub && nmatch > 1) || dfa->nbackref) |
| { |
| re_dfastate_t *pstate = mctx.state_log[match_last]; |
| mctx.last_node = check_halt_state_context (&mctx, pstate, |
| match_last); |
| } |
| if ((!preg->no_sub && nmatch > 1 && dfa->has_plural_match) |
| || dfa->nbackref) |
| { |
| err = prune_impossible_nodes (&mctx); |
| if (err == REG_NOERROR) |
| break; |
| if (BE (err != REG_NOMATCH, 0)) |
| goto free_return; |
| match_last = -1; |
| } |
| else |
| break; /* We found a match. */ |
| } |
| } |
| |
| match_ctx_clean (&mctx); |
| } |
| |
| #ifdef DEBUG |
| assert (match_last != -1); |
| assert (err == REG_NOERROR); |
| #endif |
| |
| /* Set pmatch[] if we need. */ |
| if (nmatch > 0) |
| { |
| int reg_idx; |
| |
| /* Initialize registers. */ |
| for (reg_idx = 1; reg_idx < nmatch; ++reg_idx) |
| pmatch[reg_idx].rm_so = pmatch[reg_idx].rm_eo = -1; |
| |
| /* Set the points where matching start/end. */ |
| pmatch[0].rm_so = 0; |
| pmatch[0].rm_eo = mctx.match_last; |
| |
| if (!preg->no_sub && nmatch > 1) |
| { |
| err = set_regs (preg, &mctx, nmatch, pmatch, |
| dfa->has_plural_match && dfa->nbackref > 0); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| |
| /* At last, add the offset to the each registers, since we slided |
| the buffers so that we could assume that the matching starts |
| from 0. */ |
| for (reg_idx = 0; reg_idx < nmatch; ++reg_idx) |
| if (pmatch[reg_idx].rm_so != -1) |
| { |
| #ifdef RE_ENABLE_I18N |
| if (BE (mctx.input.offsets_needed != 0, 0)) |
| { |
| pmatch[reg_idx].rm_so = |
| (pmatch[reg_idx].rm_so == mctx.input.valid_len |
| ? mctx.input.valid_raw_len |
| : mctx.input.offsets[pmatch[reg_idx].rm_so]); |
| pmatch[reg_idx].rm_eo = |
| (pmatch[reg_idx].rm_eo == mctx.input.valid_len |
| ? mctx.input.valid_raw_len |
| : mctx.input.offsets[pmatch[reg_idx].rm_eo]); |
| } |
| #else |
| assert (mctx.input.offsets_needed == 0); |
| #endif |
| pmatch[reg_idx].rm_so += match_first; |
| pmatch[reg_idx].rm_eo += match_first; |
| } |
| for (reg_idx = 0; reg_idx < extra_nmatch; ++reg_idx) |
| { |
| pmatch[nmatch + reg_idx].rm_so = -1; |
| pmatch[nmatch + reg_idx].rm_eo = -1; |
| } |
| |
| if (dfa->subexp_map) |
| for (reg_idx = 0; reg_idx + 1 < nmatch; reg_idx++) |
| if (dfa->subexp_map[reg_idx] != reg_idx) |
| { |
| pmatch[reg_idx + 1].rm_so |
| = pmatch[dfa->subexp_map[reg_idx] + 1].rm_so; |
| pmatch[reg_idx + 1].rm_eo |
| = pmatch[dfa->subexp_map[reg_idx] + 1].rm_eo; |
| } |
| } |
| |
| free_return: |
| re_free (mctx.state_log); |
| if (dfa->nbackref) |
| match_ctx_free (&mctx); |
| re_string_destruct (&mctx.input); |
| return err; |
| } |
| |
| static reg_errcode_t |
| prune_impossible_nodes (re_match_context_t *mctx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int halt_node, match_last; |
| reg_errcode_t ret; |
| re_dfastate_t **sifted_states; |
| re_dfastate_t **lim_states = NULL; |
| re_sift_context_t sctx; |
| #ifdef DEBUG |
| assert (mctx->state_log != NULL); |
| #endif |
| match_last = mctx->match_last; |
| halt_node = mctx->last_node; |
| |
| /* Avoid overflow. */ |
| if (BE (SIZE_MAX / sizeof (re_dfastate_t *) <= match_last, 0)) |
| return REG_ESPACE; |
| |
| sifted_states = re_malloc (re_dfastate_t *, match_last + 1); |
| if (BE (sifted_states == NULL, 0)) |
| { |
| ret = REG_ESPACE; |
| goto free_return; |
| } |
| if (dfa->nbackref) |
| { |
| lim_states = re_malloc (re_dfastate_t *, match_last + 1); |
| if (BE (lim_states == NULL, 0)) |
| { |
| ret = REG_ESPACE; |
| goto free_return; |
| } |
| while (1) |
| { |
| memset (lim_states, '\0', |
| sizeof (re_dfastate_t *) * (match_last + 1)); |
| sift_ctx_init (&sctx, sifted_states, lim_states, halt_node, |
| match_last); |
| ret = sift_states_backward (mctx, &sctx); |
| re_node_set_free (&sctx.limits); |
| if (BE (ret != REG_NOERROR, 0)) |
| goto free_return; |
| if (sifted_states[0] != NULL || lim_states[0] != NULL) |
| break; |
| do |
| { |
| --match_last; |
| if (match_last < 0) |
| { |
| 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); |
| } |
| ret = merge_state_array (dfa, sifted_states, lim_states, |
| match_last + 1); |
| re_free (lim_states); |
| lim_states = NULL; |
| if (BE (ret != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| else |
| { |
| sift_ctx_init (&sctx, sifted_states, lim_states, halt_node, match_last); |
| ret = sift_states_backward (mctx, &sctx); |
| re_node_set_free (&sctx.limits); |
| if (BE (ret != REG_NOERROR, 0)) |
| goto free_return; |
| if (sifted_states[0] == NULL) |
| { |
| ret = REG_NOMATCH; |
| goto free_return; |
| } |
| } |
| re_free (mctx->state_log); |
| mctx->state_log = sifted_states; |
| sifted_states = NULL; |
| mctx->last_node = halt_node; |
| mctx->match_last = match_last; |
| ret = REG_NOERROR; |
| free_return: |
| re_free (sifted_states); |
| re_free (lim_states); |
| return ret; |
| } |
| |
| /* Acquire an initial state and return it. |
| We must select appropriate initial state depending on the context, |
| since initial states may have constraints like "\<", "^", etc.. */ |
| |
| static inline re_dfastate_t * |
| __attribute ((always_inline)) internal_function |
| acquire_init_state_context (reg_errcode_t *err, const re_match_context_t *mctx, |
| int idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| if (dfa->init_state->has_constraint) |
| { |
| unsigned int context; |
| context = re_string_context_at (&mctx->input, idx - 1, mctx->eflags); |
| if (IS_WORD_CONTEXT (context)) |
| return dfa->init_state_word; |
| else if (IS_ORDINARY_CONTEXT (context)) |
| return dfa->init_state; |
| else if (IS_BEGBUF_CONTEXT (context) && IS_NEWLINE_CONTEXT (context)) |
| return dfa->init_state_begbuf; |
| else if (IS_NEWLINE_CONTEXT (context)) |
| return dfa->init_state_nl; |
| else if (IS_BEGBUF_CONTEXT (context)) |
| { |
| /* It is relatively rare case, then calculate on demand. */ |
| return re_acquire_state_context (err, dfa, |
| dfa->init_state->entrance_nodes, |
| context); |
| } |
| else |
| /* Must not happen? */ |
| return dfa->init_state; |
| } |
| else |
| return dfa->init_state; |
| } |
| |
| /* Check whether the regular expression match input string INPUT or not, |
| and return the index where the matching end, return -1 if not match, |
| or return -2 in case of an error. |
| FL_LONGEST_MATCH means we want the POSIX longest matching. |
| If P_MATCH_FIRST is not NULL, and the match fails, it is set to the |
| next place where we may want to try matching. |
| Note that the matcher assume that the matching starts from the current |
| index of the buffer. */ |
| |
| static int |
| internal_function |
| check_matching (re_match_context_t *mctx, int fl_longest_match, |
| int *p_match_first) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err; |
| int match = 0; |
| int match_last = -1; |
| int cur_str_idx = re_string_cur_idx (&mctx->input); |
| re_dfastate_t *cur_state; |
| int at_init_state = p_match_first != NULL; |
| int next_start_idx = cur_str_idx; |
| |
| err = REG_NOERROR; |
| cur_state = acquire_init_state_context (&err, mctx, cur_str_idx); |
| /* An initial state must not be NULL (invalid). */ |
| if (BE (cur_state == NULL, 0)) |
| { |
| assert (err == REG_ESPACE); |
| return -2; |
| } |
| |
| if (mctx->state_log != NULL) |
| { |
| mctx->state_log[cur_str_idx] = cur_state; |
| |
| /* Check OP_OPEN_SUBEXP in the initial state in case that we use them |
| later. E.g. Processing back references. */ |
| if (BE (dfa->nbackref, 0)) |
| { |
| at_init_state = 0; |
| err = check_subexp_matching_top (mctx, &cur_state->nodes, 0); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| |
| if (cur_state->has_backref) |
| { |
| err = transit_state_bkref (mctx, &cur_state->nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| } |
| } |
| |
| /* If the RE accepts NULL string. */ |
| if (BE (cur_state->halt, 0)) |
| { |
| if (!cur_state->has_constraint |
| || check_halt_state_context (mctx, cur_state, cur_str_idx)) |
| { |
| if (!fl_longest_match) |
| return cur_str_idx; |
| else |
| { |
| match_last = cur_str_idx; |
| match = 1; |
| } |
| } |
| } |
| |
| while (!re_string_eoi (&mctx->input)) |
| { |
| re_dfastate_t *old_state = cur_state; |
| int next_char_idx = re_string_cur_idx (&mctx->input) + 1; |
| |
| if (BE (next_char_idx >= mctx->input.bufs_len, 0) |
| || (BE (next_char_idx >= mctx->input.valid_len, 0) |
| && mctx->input.valid_len < mctx->input.len)) |
| { |
| err = extend_buffers (mctx); |
| if (BE (err != REG_NOERROR, 0)) |
| { |
| assert (err == REG_ESPACE); |
| return -2; |
| } |
| } |
| |
| cur_state = transit_state (&err, mctx, cur_state); |
| if (mctx->state_log != NULL) |
| cur_state = merge_state_with_log (&err, mctx, cur_state); |
| |
| if (cur_state == NULL) |
| { |
| /* Reached the invalid state or an error. Try to recover a valid |
| state using the state log, if available and if we have not |
| already found a valid (even if not the longest) match. */ |
| if (BE (err != REG_NOERROR, 0)) |
| return -2; |
| |
| if (mctx->state_log == NULL |
| || (match && !fl_longest_match) |
| || (cur_state = find_recover_state (&err, mctx)) == NULL) |
| break; |
| } |
| |
| if (BE (at_init_state, 0)) |
| { |
| if (old_state == cur_state) |
| next_start_idx = next_char_idx; |
| else |
| at_init_state = 0; |
| } |
| |
| if (cur_state->halt) |
| { |
| /* Reached a halt state. |
| Check the halt state can satisfy the current context. */ |
| if (!cur_state->has_constraint |
| || check_halt_state_context (mctx, cur_state, |
| re_string_cur_idx (&mctx->input))) |
| { |
| /* We found an appropriate halt state. */ |
| match_last = re_string_cur_idx (&mctx->input); |
| match = 1; |
| |
| /* We found a match, do not modify match_first below. */ |
| p_match_first = NULL; |
| if (!fl_longest_match) |
| break; |
| } |
| } |
| } |
| |
| if (p_match_first) |
| *p_match_first += next_start_idx; |
| |
| return match_last; |
| } |
| |
| /* Check NODE match the current context. */ |
| |
| static int |
| internal_function |
| check_halt_node_context (const re_dfa_t *dfa, int node, unsigned int context) |
| { |
| re_token_type_t type = dfa->nodes[node].type; |
| unsigned int constraint = dfa->nodes[node].constraint; |
| if (type != END_OF_RE) |
| return 0; |
| if (!constraint) |
| return 1; |
| if (NOT_SATISFY_NEXT_CONSTRAINT (constraint, context)) |
| return 0; |
| return 1; |
| } |
| |
| /* Check the halt state STATE match the current context. |
| Return 0 if not match, if the node, STATE has, is a halt node and |
| match the context, return the node. */ |
| |
| static int |
| internal_function |
| check_halt_state_context (const re_match_context_t *mctx, |
| const re_dfastate_t *state, int idx) |
| { |
| int i; |
| unsigned int context; |
| #ifdef DEBUG |
| assert (state->halt); |
| #endif |
| context = re_string_context_at (&mctx->input, idx, mctx->eflags); |
| for (i = 0; i < state->nodes.nelem; ++i) |
| if (check_halt_node_context (mctx->dfa, state->nodes.elems[i], context)) |
| return state->nodes.elems[i]; |
| return 0; |
| } |
| |
| /* Compute the next node to which "NFA" transit from NODE("NFA" is a NFA |
| corresponding to the DFA). |
| Return the destination node, and update EPS_VIA_NODES, return -1 in case |
| of errors. */ |
| |
| static int |
| internal_function |
| proceed_next_node (const re_match_context_t *mctx, int nregs, regmatch_t *regs, |
| int *pidx, int node, re_node_set *eps_via_nodes, |
| struct re_fail_stack_t *fs) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int i, err; |
| if (IS_EPSILON_NODE (dfa->nodes[node].type)) |
| { |
| re_node_set *cur_nodes = &mctx->state_log[*pidx]->nodes; |
| re_node_set *edests = &dfa->edests[node]; |
| int dest_node; |
| err = re_node_set_insert (eps_via_nodes, node); |
| if (BE (err < 0, 0)) |
| return -2; |
| /* Pick up a valid destination, or return -1 if none is found. */ |
| for (dest_node = -1, i = 0; i < edests->nelem; ++i) |
| { |
| int candidate = edests->elems[i]; |
| if (!re_node_set_contains (cur_nodes, candidate)) |
| continue; |
| if (dest_node == -1) |
| dest_node = candidate; |
| |
| else |
| { |
| /* In order to avoid infinite loop like "(a*)*", return the second |
| epsilon-transition if the first was already considered. */ |
| if (re_node_set_contains (eps_via_nodes, dest_node)) |
| return candidate; |
| |
| /* Otherwise, push the second epsilon-transition on the fail stack. */ |
| else if (fs != NULL |
| && push_fail_stack (fs, *pidx, candidate, nregs, regs, |
| eps_via_nodes)) |
| return -2; |
| |
| /* We know we are going to exit. */ |
| break; |
| } |
| } |
| return dest_node; |
| } |
| else |
| { |
| int naccepted = 0; |
| re_token_type_t type = dfa->nodes[node].type; |
| |
| #ifdef RE_ENABLE_I18N |
| if (dfa->nodes[node].accept_mb) |
| naccepted = check_node_accept_bytes (dfa, node, &mctx->input, *pidx); |
| else |
| #endif /* RE_ENABLE_I18N */ |
| if (type == OP_BACK_REF) |
| { |
| int subexp_idx = dfa->nodes[node].opr.idx + 1; |
| naccepted = regs[subexp_idx].rm_eo - regs[subexp_idx].rm_so; |
| if (fs != NULL) |
| { |
| if (regs[subexp_idx].rm_so == -1 || regs[subexp_idx].rm_eo == -1) |
| return -1; |
| else if (naccepted) |
| { |
| char *buf = (char *) re_string_get_buffer (&mctx->input); |
| if (memcmp (buf + regs[subexp_idx].rm_so, buf + *pidx, |
| naccepted) != 0) |
| return -1; |
| } |
| } |
| |
| if (naccepted == 0) |
| { |
| int dest_node; |
| err = re_node_set_insert (eps_via_nodes, node); |
| if (BE (err < 0, 0)) |
| return -2; |
| dest_node = dfa->edests[node].elems[0]; |
| if (re_node_set_contains (&mctx->state_log[*pidx]->nodes, |
| dest_node)) |
| return dest_node; |
| } |
| } |
| |
| if (naccepted != 0 |
| || check_node_accept (mctx, dfa->nodes + node, *pidx)) |
| { |
| int dest_node = dfa->nexts[node]; |
| *pidx = (naccepted == 0) ? *pidx + 1 : *pidx + naccepted; |
| if (fs && (*pidx > mctx->match_last || mctx->state_log[*pidx] == NULL |
| || !re_node_set_contains (&mctx->state_log[*pidx]->nodes, |
| dest_node))) |
| return -1; |
| re_node_set_empty (eps_via_nodes); |
| return dest_node; |
| } |
| } |
| return -1; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| push_fail_stack (struct re_fail_stack_t *fs, int str_idx, int dest_node, |
| int nregs, regmatch_t *regs, re_node_set *eps_via_nodes) |
| { |
| reg_errcode_t err; |
| int num = fs->num++; |
| if (fs->num == fs->alloc) |
| { |
| struct re_fail_stack_ent_t *new_array; |
| new_array = realloc (fs->stack, (sizeof (struct re_fail_stack_ent_t) |
| * fs->alloc * 2)); |
| if (new_array == NULL) |
| return REG_ESPACE; |
| fs->alloc *= 2; |
| fs->stack = new_array; |
| } |
| fs->stack[num].idx = str_idx; |
| fs->stack[num].node = dest_node; |
| fs->stack[num].regs = re_malloc (regmatch_t, nregs); |
| if (fs->stack[num].regs == NULL) |
| return REG_ESPACE; |
| memcpy (fs->stack[num].regs, regs, sizeof (regmatch_t) * nregs); |
| err = re_node_set_init_copy (&fs->stack[num].eps_via_nodes, eps_via_nodes); |
| return err; |
| } |
| |
| static int |
| internal_function |
| pop_fail_stack (struct re_fail_stack_t *fs, int *pidx, int nregs, |
| regmatch_t *regs, re_node_set *eps_via_nodes) |
| { |
| int num = --fs->num; |
| assert (num >= 0); |
| *pidx = fs->stack[num].idx; |
| memcpy (regs, fs->stack[num].regs, sizeof (regmatch_t) * nregs); |
| re_node_set_free (eps_via_nodes); |
| re_free (fs->stack[num].regs); |
| *eps_via_nodes = fs->stack[num].eps_via_nodes; |
| return fs->stack[num].node; |
| } |
| |
| /* Set the positions where the subexpressions are starts/ends to registers |
| PMATCH. |
| Note: We assume that pmatch[0] is already set, and |
| pmatch[i].rm_so == pmatch[i].rm_eo == -1 for 0 < i < nmatch. */ |
| |
| static reg_errcode_t |
| internal_function |
| set_regs (const regex_t *preg, const re_match_context_t *mctx, size_t nmatch, |
| regmatch_t *pmatch, int fl_backtrack) |
| { |
| const re_dfa_t *dfa = (const re_dfa_t *) preg->buffer; |
| int idx, cur_node; |
| re_node_set eps_via_nodes; |
| struct re_fail_stack_t *fs; |
| struct re_fail_stack_t fs_body = { 0, 2, NULL }; |
| regmatch_t *prev_idx_match; |
| int prev_idx_match_malloced = 0; |
| |
| #ifdef DEBUG |
| assert (nmatch > 1); |
| assert (mctx->state_log != NULL); |
| #endif |
| if (fl_backtrack) |
| { |
| fs = &fs_body; |
| fs->stack = re_malloc (struct re_fail_stack_ent_t, fs->alloc); |
| if (fs->stack == NULL) |
| return REG_ESPACE; |
| } |
| else |
| fs = NULL; |
| |
| cur_node = dfa->init_node; |
| re_node_set_init_empty (&eps_via_nodes); |
| |
| #ifdef HAVE_ALLOCA |
| if (__libc_use_alloca (nmatch * sizeof (regmatch_t))) |
| prev_idx_match = (regmatch_t *) alloca (nmatch * sizeof (regmatch_t)); |
| else |
| #endif |
| { |
| prev_idx_match = re_malloc (regmatch_t, nmatch); |
| if (prev_idx_match == NULL) |
| { |
| free_fail_stack_return (fs); |
| return REG_ESPACE; |
| } |
| prev_idx_match_malloced = 1; |
| } |
| memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch); |
| |
| for (idx = pmatch[0].rm_so; idx <= pmatch[0].rm_eo ;) |
| { |
| update_regs (dfa, pmatch, prev_idx_match, cur_node, idx, nmatch); |
| |
| if (idx == pmatch[0].rm_eo && cur_node == mctx->last_node) |
| { |
| int reg_idx; |
| if (fs) |
| { |
| for (reg_idx = 0; reg_idx < nmatch; ++reg_idx) |
| if (pmatch[reg_idx].rm_so > -1 && pmatch[reg_idx].rm_eo == -1) |
| break; |
| if (reg_idx == nmatch) |
| { |
| re_node_set_free (&eps_via_nodes); |
| if (prev_idx_match_malloced) |
| re_free (prev_idx_match); |
| return free_fail_stack_return (fs); |
| } |
| cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, |
| &eps_via_nodes); |
| } |
| else |
| { |
| re_node_set_free (&eps_via_nodes); |
| if (prev_idx_match_malloced) |
| re_free (prev_idx_match); |
| return REG_NOERROR; |
| } |
| } |
| |
| /* Proceed to next node. */ |
| cur_node = proceed_next_node (mctx, nmatch, pmatch, &idx, cur_node, |
| &eps_via_nodes, fs); |
| |
| if (BE (cur_node < 0, 0)) |
| { |
| if (BE (cur_node == -2, 0)) |
| { |
| re_node_set_free (&eps_via_nodes); |
| if (prev_idx_match_malloced) |
| re_free (prev_idx_match); |
| free_fail_stack_return (fs); |
| return REG_ESPACE; |
| } |
| if (fs) |
| cur_node = pop_fail_stack (fs, &idx, nmatch, pmatch, |
| &eps_via_nodes); |
| else |
| { |
| re_node_set_free (&eps_via_nodes); |
| if (prev_idx_match_malloced) |
| re_free (prev_idx_match); |
| return REG_NOMATCH; |
| } |
| } |
| } |
| re_node_set_free (&eps_via_nodes); |
| if (prev_idx_match_malloced) |
| re_free (prev_idx_match); |
| return free_fail_stack_return (fs); |
| } |
| |
| static reg_errcode_t |
| internal_function |
| free_fail_stack_return (struct re_fail_stack_t *fs) |
| { |
| if (fs) |
| { |
| int fs_idx; |
| for (fs_idx = 0; fs_idx < fs->num; ++fs_idx) |
| { |
| re_node_set_free (&fs->stack[fs_idx].eps_via_nodes); |
| re_free (fs->stack[fs_idx].regs); |
| } |
| re_free (fs->stack); |
| } |
| return REG_NOERROR; |
| } |
| |
| static void |
| internal_function |
| update_regs (const re_dfa_t *dfa, regmatch_t *pmatch, |
| regmatch_t *prev_idx_match, int cur_node, int cur_idx, int nmatch) |
| { |
| int type = dfa->nodes[cur_node].type; |
| if (type == OP_OPEN_SUBEXP) |
| { |
| int reg_num = dfa->nodes[cur_node].opr.idx + 1; |
| |
| /* We are at the first node of this sub expression. */ |
| if (reg_num < nmatch) |
| { |
| pmatch[reg_num].rm_so = cur_idx; |
| pmatch[reg_num].rm_eo = -1; |
| } |
| } |
| else if (type == OP_CLOSE_SUBEXP) |
| { |
| int reg_num = dfa->nodes[cur_node].opr.idx + 1; |
| if (reg_num < nmatch) |
| { |
| /* We are at the last node of this sub expression. */ |
| if (pmatch[reg_num].rm_so < cur_idx) |
| { |
| pmatch[reg_num].rm_eo = cur_idx; |
| /* This is a non-empty match or we are not inside an optional |
| subexpression. Accept this right away. */ |
| memcpy (prev_idx_match, pmatch, sizeof (regmatch_t) * nmatch); |
| } |
| else |
| { |
| if (dfa->nodes[cur_node].opt_subexp |
| && prev_idx_match[reg_num].rm_so != -1) |
| /* We transited through an empty match for an optional |
| subexpression, like (a?)*, and this is not the subexp's |
| first match. Copy back the old content of the registers |
| so that matches of an inner subexpression are undone as |
| well, like in ((a?))*. */ |
| memcpy (pmatch, prev_idx_match, sizeof (regmatch_t) * nmatch); |
| else |
| /* We completed a subexpression, but it may be part of |
| an optional one, so do not update PREV_IDX_MATCH. */ |
| pmatch[reg_num].rm_eo = cur_idx; |
| } |
| } |
| } |
| } |
| |
| /* This function checks the STATE_LOG from the SCTX->last_str_idx to 0 |
| and sift the nodes in each states according to the following rules. |
| Updated state_log will be wrote to STATE_LOG. |
| |
| Rules: We throw away the Node `a' in the STATE_LOG[STR_IDX] if... |
| 1. When STR_IDX == MATCH_LAST(the last index in the state_log): |
| If `a' isn't the LAST_NODE and `a' can't epsilon transit to |
| the LAST_NODE, we throw away the node `a'. |
| 2. When 0 <= STR_IDX < MATCH_LAST and `a' accepts |
| string `s' and transit to `b': |
| i. If 'b' isn't in the STATE_LOG[STR_IDX+strlen('s')], we throw |
| away the node `a'. |
| ii. If 'b' is in the STATE_LOG[STR_IDX+strlen('s')] but 'b' is |
| thrown away, we throw away the node `a'. |
| 3. When 0 <= STR_IDX < MATCH_LAST and 'a' epsilon transit to 'b': |
| i. If 'b' isn't in the STATE_LOG[STR_IDX], we throw away the |
| node `a'. |
| ii. If 'b' is in the STATE_LOG[STR_IDX] but 'b' is thrown away, |
| we throw away the node `a'. */ |
| |
| #define STATE_NODE_CONTAINS(state,node) \ |
| ((state) != NULL && re_node_set_contains (&(state)->nodes, node)) |
| |
| static reg_errcode_t |
| internal_function |
| sift_states_backward (const re_match_context_t *mctx, re_sift_context_t *sctx) |
| { |
| reg_errcode_t err; |
| int null_cnt = 0; |
| int str_idx = sctx->last_str_idx; |
| re_node_set cur_dest; |
| |
| #ifdef DEBUG |
| assert (mctx->state_log != NULL && mctx->state_log[str_idx] != NULL); |
| #endif |
| |
| /* Build sifted state_log[str_idx]. It has the nodes which can epsilon |
| transit to the last_node and the last_node itself. */ |
| err = re_node_set_init_1 (&cur_dest, sctx->last_node); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| |
| /* Then check each states in the state_log. */ |
| while (str_idx > 0) |
| { |
| /* Update counters. */ |
| null_cnt = (sctx->sifted_states[str_idx] == NULL) ? null_cnt + 1 : 0; |
| if (null_cnt > mctx->max_mb_elem_len) |
| { |
| memset (sctx->sifted_states, '\0', |
| sizeof (re_dfastate_t *) * str_idx); |
| re_node_set_free (&cur_dest); |
| return REG_NOERROR; |
| } |
| re_node_set_empty (&cur_dest); |
| --str_idx; |
| |
| if (mctx->state_log[str_idx]) |
| { |
| err = build_sifted_states (mctx, sctx, str_idx, &cur_dest); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| |
| /* Add all the nodes which satisfy the following conditions: |
| - It can epsilon transit to a node in CUR_DEST. |
| - It is in CUR_SRC. |
| And update state_log. */ |
| err = update_cur_sifted_state (mctx, sctx, str_idx, &cur_dest); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| err = REG_NOERROR; |
| free_return: |
| re_node_set_free (&cur_dest); |
| return err; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| build_sifted_states (const re_match_context_t *mctx, re_sift_context_t *sctx, |
| int str_idx, re_node_set *cur_dest) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| const re_node_set *cur_src = &mctx->state_log[str_idx]->non_eps_nodes; |
| int i; |
| |
| /* Then build the next sifted state. |
| We build the next sifted state on `cur_dest', and update |
| `sifted_states[str_idx]' with `cur_dest'. |
| Note: |
| `cur_dest' is the sifted state from `state_log[str_idx + 1]'. |
| `cur_src' points the node_set of the old `state_log[str_idx]' |
| (with the epsilon nodes pre-filtered out). */ |
| for (i = 0; i < cur_src->nelem; i++) |
| { |
| int prev_node = cur_src->elems[i]; |
| int naccepted = 0; |
| int ret; |
| |
| #ifdef DEBUG |
| re_token_type_t type = dfa->nodes[prev_node].type; |
| assert (!IS_EPSILON_NODE (type)); |
| #endif |
| #ifdef RE_ENABLE_I18N |
| /* If the node may accept `multi byte'. */ |
| if (dfa->nodes[prev_node].accept_mb) |
| naccepted = sift_states_iter_mb (mctx, sctx, prev_node, |
| str_idx, sctx->last_str_idx); |
| #endif /* RE_ENABLE_I18N */ |
| |
| /* We don't check backreferences here. |
| See update_cur_sifted_state(). */ |
| if (!naccepted |
| && check_node_accept (mctx, dfa->nodes + prev_node, str_idx) |
| && STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + 1], |
| dfa->nexts[prev_node])) |
| naccepted = 1; |
| |
| if (naccepted == 0) |
| continue; |
| |
| if (sctx->limits.nelem) |
| { |
| int to_idx = str_idx + naccepted; |
| if (check_dst_limits (mctx, &sctx->limits, |
| dfa->nexts[prev_node], to_idx, |
| prev_node, str_idx)) |
| continue; |
| } |
| ret = re_node_set_insert (cur_dest, prev_node); |
| if (BE (ret == -1, 0)) |
| return REG_ESPACE; |
| } |
| |
| return REG_NOERROR; |
| } |
| |
| /* Helper functions. */ |
| |
| static reg_errcode_t |
| internal_function |
| clean_state_log_if_needed (re_match_context_t *mctx, int next_state_log_idx) |
| { |
| int top = mctx->state_log_top; |
| |
| if (next_state_log_idx >= mctx->input.bufs_len |
| || (next_state_log_idx >= mctx->input.valid_len |
| && mctx->input.valid_len < mctx->input.len)) |
| { |
| reg_errcode_t err; |
| err = extend_buffers (mctx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| |
| if (top < next_state_log_idx) |
| { |
| memset (mctx->state_log + top + 1, '\0', |
| sizeof (re_dfastate_t *) * (next_state_log_idx - top)); |
| mctx->state_log_top = next_state_log_idx; |
| } |
| return REG_NOERROR; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| merge_state_array (const re_dfa_t *dfa, re_dfastate_t **dst, |
| re_dfastate_t **src, int num) |
| { |
| int st_idx; |
| reg_errcode_t err; |
| for (st_idx = 0; st_idx < num; ++st_idx) |
| { |
| if (dst[st_idx] == NULL) |
| dst[st_idx] = src[st_idx]; |
| else if (src[st_idx] != NULL) |
| { |
| re_node_set merged_set; |
| err = re_node_set_init_union (&merged_set, &dst[st_idx]->nodes, |
| &src[st_idx]->nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| dst[st_idx] = re_acquire_state (&err, dfa, &merged_set); |
| re_node_set_free (&merged_set); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| } |
| return REG_NOERROR; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| update_cur_sifted_state (const re_match_context_t *mctx, |
| re_sift_context_t *sctx, int str_idx, |
| re_node_set *dest_nodes) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err = REG_NOERROR; |
| const re_node_set *candidates; |
| candidates = ((mctx->state_log[str_idx] == NULL) ? NULL |
| : &mctx->state_log[str_idx]->nodes); |
| |
| if (dest_nodes->nelem == 0) |
| sctx->sifted_states[str_idx] = NULL; |
| else |
| { |
| if (candidates) |
| { |
| /* At first, add the nodes which can epsilon transit to a node in |
| DEST_NODE. */ |
| err = add_epsilon_src_nodes (dfa, dest_nodes, candidates); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| |
| /* Then, check the limitations in the current sift_context. */ |
| if (sctx->limits.nelem) |
| { |
| err = check_subexp_limits (dfa, dest_nodes, candidates, &sctx->limits, |
| mctx->bkref_ents, str_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| } |
| |
| sctx->sifted_states[str_idx] = re_acquire_state (&err, dfa, dest_nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| |
| if (candidates && mctx->state_log[str_idx]->has_backref) |
| { |
| err = sift_states_bkref (mctx, sctx, str_idx, candidates); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| return REG_NOERROR; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| add_epsilon_src_nodes (const re_dfa_t *dfa, re_node_set *dest_nodes, |
| const re_node_set *candidates) |
| { |
| reg_errcode_t err = REG_NOERROR; |
| int i; |
| |
| re_dfastate_t *state = re_acquire_state (&err, dfa, dest_nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| |
| if (!state->inveclosure.alloc) |
| { |
| err = re_node_set_alloc (&state->inveclosure, dest_nodes->nelem); |
| if (BE (err != REG_NOERROR, 0)) |
| return REG_ESPACE; |
| for (i = 0; i < dest_nodes->nelem; i++) |
| { |
| err = re_node_set_merge (&state->inveclosure, |
| dfa->inveclosures + dest_nodes->elems[i]); |
| if (BE (err != REG_NOERROR, 0)) |
| return REG_ESPACE; |
| } |
| } |
| return re_node_set_add_intersect (dest_nodes, candidates, |
| &state->inveclosure); |
| } |
| |
| static reg_errcode_t |
| internal_function |
| sub_epsilon_src_nodes (const re_dfa_t *dfa, int node, re_node_set *dest_nodes, |
| const re_node_set *candidates) |
| { |
| int ecl_idx; |
| reg_errcode_t err; |
| re_node_set *inv_eclosure = dfa->inveclosures + node; |
| re_node_set except_nodes; |
| re_node_set_init_empty (&except_nodes); |
| for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx) |
| { |
| int cur_node = inv_eclosure->elems[ecl_idx]; |
| if (cur_node == node) |
| continue; |
| if (IS_EPSILON_NODE (dfa->nodes[cur_node].type)) |
| { |
| int edst1 = dfa->edests[cur_node].elems[0]; |
| int edst2 = ((dfa->edests[cur_node].nelem > 1) |
| ? dfa->edests[cur_node].elems[1] : -1); |
| if ((!re_node_set_contains (inv_eclosure, edst1) |
| && re_node_set_contains (dest_nodes, edst1)) |
| || (edst2 > 0 |
| && !re_node_set_contains (inv_eclosure, edst2) |
| && re_node_set_contains (dest_nodes, edst2))) |
| { |
| err = re_node_set_add_intersect (&except_nodes, candidates, |
| dfa->inveclosures + cur_node); |
| if (BE (err != REG_NOERROR, 0)) |
| { |
| re_node_set_free (&except_nodes); |
| return err; |
| } |
| } |
| } |
| } |
| for (ecl_idx = 0; ecl_idx < inv_eclosure->nelem; ++ecl_idx) |
| { |
| int cur_node = inv_eclosure->elems[ecl_idx]; |
| if (!re_node_set_contains (&except_nodes, cur_node)) |
| { |
| int idx = re_node_set_contains (dest_nodes, cur_node) - 1; |
| re_node_set_remove_at (dest_nodes, idx); |
| } |
| } |
| re_node_set_free (&except_nodes); |
| return REG_NOERROR; |
| } |
| |
| static int |
| internal_function |
| check_dst_limits (const re_match_context_t *mctx, re_node_set *limits, |
| int dst_node, int dst_idx, int src_node, int src_idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int lim_idx, src_pos, dst_pos; |
| |
| int dst_bkref_idx = search_cur_bkref_entry (mctx, dst_idx); |
| int src_bkref_idx = search_cur_bkref_entry (mctx, src_idx); |
| for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx) |
| { |
| int subexp_idx; |
| struct re_backref_cache_entry *ent; |
| ent = mctx->bkref_ents + limits->elems[lim_idx]; |
| subexp_idx = dfa->nodes[ent->node].opr.idx; |
| |
| dst_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx], |
| subexp_idx, dst_node, dst_idx, |
| dst_bkref_idx); |
| src_pos = check_dst_limits_calc_pos (mctx, limits->elems[lim_idx], |
| subexp_idx, src_node, src_idx, |
| src_bkref_idx); |
| |
| /* In case of: |
| <src> <dst> ( <subexp> ) |
| ( <subexp> ) <src> <dst> |
| ( <subexp1> <src> <subexp2> <dst> <subexp3> ) */ |
| if (src_pos == dst_pos) |
| continue; /* This is unrelated limitation. */ |
| else |
| return 1; |
| } |
| return 0; |
| } |
| |
| static int |
| internal_function |
| check_dst_limits_calc_pos_1 (const re_match_context_t *mctx, int boundaries, |
| int subexp_idx, int from_node, int bkref_idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| const re_node_set *eclosures = dfa->eclosures + from_node; |
| int node_idx; |
| |
| /* Else, we are on the boundary: examine the nodes on the epsilon |
| closure. */ |
| for (node_idx = 0; node_idx < eclosures->nelem; ++node_idx) |
| { |
| int node = eclosures->elems[node_idx]; |
| switch (dfa->nodes[node].type) |
| { |
| case OP_BACK_REF: |
| if (bkref_idx != -1) |
| { |
| struct re_backref_cache_entry *ent = mctx->bkref_ents + bkref_idx; |
| do |
| { |
| int dst, cpos; |
| |
| if (ent->node != node) |
| continue; |
| |
| if (subexp_idx < BITSET_WORD_BITS |
| && !(ent->eps_reachable_subexps_map |
| & ((bitset_word_t) 1 << subexp_idx))) |
| continue; |
| |
| /* Recurse trying to reach the OP_OPEN_SUBEXP and |
| OP_CLOSE_SUBEXP cases below. But, if the |
| destination node is the same node as the source |
| node, don't recurse because it would cause an |
| infinite loop: a regex that exhibits this behavior |
| is ()\1*\1* */ |
| dst = dfa->edests[node].elems[0]; |
| if (dst == from_node) |
| { |
| if (boundaries & 1) |
| return -1; |
| else /* if (boundaries & 2) */ |
| return 0; |
| } |
| |
| cpos = |
| check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx, |
| dst, bkref_idx); |
| if (cpos == -1 /* && (boundaries & 1) */) |
| return -1; |
| if (cpos == 0 && (boundaries & 2)) |
| return 0; |
| |
| if (subexp_idx < BITSET_WORD_BITS) |
| ent->eps_reachable_subexps_map |
| &= ~((bitset_word_t) 1 << subexp_idx); |
| } |
| while (ent++->more); |
| } |
| break; |
| |
| case OP_OPEN_SUBEXP: |
| if ((boundaries & 1) && subexp_idx == dfa->nodes[node].opr.idx) |
| return -1; |
| break; |
| |
| case OP_CLOSE_SUBEXP: |
| if ((boundaries & 2) && subexp_idx == dfa->nodes[node].opr.idx) |
| return 0; |
| break; |
| |
| default: |
| break; |
| } |
| } |
| |
| return (boundaries & 2) ? 1 : 0; |
| } |
| |
| static int |
| internal_function |
| check_dst_limits_calc_pos (const re_match_context_t *mctx, int limit, |
| int subexp_idx, int from_node, int str_idx, |
| int bkref_idx) |
| { |
| struct re_backref_cache_entry *lim = mctx->bkref_ents + limit; |
| int boundaries; |
| |
| /* If we are outside the range of the subexpression, return -1 or 1. */ |
| if (str_idx < lim->subexp_from) |
| return -1; |
| |
| if (lim->subexp_to < str_idx) |
| return 1; |
| |
| /* If we are within the subexpression, return 0. */ |
| boundaries = (str_idx == lim->subexp_from); |
| boundaries |= (str_idx == lim->subexp_to) << 1; |
| if (boundaries == 0) |
| return 0; |
| |
| /* Else, examine epsilon closure. */ |
| return check_dst_limits_calc_pos_1 (mctx, boundaries, subexp_idx, |
| from_node, bkref_idx); |
| } |
| |
| /* Check the limitations of sub expressions LIMITS, and remove the nodes |
| which are against limitations from DEST_NODES. */ |
| |
| static reg_errcode_t |
| internal_function |
| check_subexp_limits (const re_dfa_t *dfa, re_node_set *dest_nodes, |
| const re_node_set *candidates, re_node_set *limits, |
| struct re_backref_cache_entry *bkref_ents, int str_idx) |
| { |
| reg_errcode_t err; |
| int node_idx, lim_idx; |
| |
| for (lim_idx = 0; lim_idx < limits->nelem; ++lim_idx) |
| { |
| int subexp_idx; |
| struct re_backref_cache_entry *ent; |
| ent = bkref_ents + limits->elems[lim_idx]; |
| |
| if (str_idx <= ent->subexp_from || ent->str_idx < str_idx) |
| continue; /* This is unrelated limitation. */ |
| |
| subexp_idx = dfa->nodes[ent->node].opr.idx; |
| if (ent->subexp_to == str_idx) |
| { |
| int ops_node = -1; |
| int cls_node = -1; |
| for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx) |
| { |
| int node = dest_nodes->elems[node_idx]; |
| re_token_type_t type = dfa->nodes[node].type; |
| if (type == OP_OPEN_SUBEXP |
| && subexp_idx == dfa->nodes[node].opr.idx) |
| ops_node = node; |
| else if (type == OP_CLOSE_SUBEXP |
| && subexp_idx == dfa->nodes[node].opr.idx) |
| cls_node = node; |
| } |
| |
| /* Check the limitation of the open subexpression. */ |
| /* Note that (ent->subexp_to = str_idx != ent->subexp_from). */ |
| if (ops_node >= 0) |
| { |
| err = sub_epsilon_src_nodes (dfa, ops_node, dest_nodes, |
| candidates); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| |
| /* Check the limitation of the close subexpression. */ |
| if (cls_node >= 0) |
| for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx) |
| { |
| int node = dest_nodes->elems[node_idx]; |
| if (!re_node_set_contains (dfa->inveclosures + node, |
| cls_node) |
| && !re_node_set_contains (dfa->eclosures + node, |
| cls_node)) |
| { |
| /* It is against this limitation. |
| Remove it form the current sifted state. */ |
| err = sub_epsilon_src_nodes (dfa, node, dest_nodes, |
| candidates); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| --node_idx; |
| } |
| } |
| } |
| else /* (ent->subexp_to != str_idx) */ |
| { |
| for (node_idx = 0; node_idx < dest_nodes->nelem; ++node_idx) |
| { |
| int node = dest_nodes->elems[node_idx]; |
| re_token_type_t type = dfa->nodes[node].type; |
| if (type == OP_CLOSE_SUBEXP || type == OP_OPEN_SUBEXP) |
| { |
| if (subexp_idx != dfa->nodes[node].opr.idx) |
| continue; |
| /* It is against this limitation. |
| Remove it form the current sifted state. */ |
| err = sub_epsilon_src_nodes (dfa, node, dest_nodes, |
| candidates); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| } |
| } |
| } |
| return REG_NOERROR; |
| } |
| |
| static reg_errcode_t |
| internal_function |
| sift_states_bkref (const re_match_context_t *mctx, re_sift_context_t *sctx, |
| int str_idx, const re_node_set *candidates) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err; |
| int node_idx, node; |
| re_sift_context_t local_sctx; |
| int first_idx = search_cur_bkref_entry (mctx, str_idx); |
| |
| if (first_idx == -1) |
| return REG_NOERROR; |
| |
| local_sctx.sifted_states = NULL; /* Mark that it hasn't been initialized. */ |
| |
| for (node_idx = 0; node_idx < candidates->nelem; ++node_idx) |
| { |
| int enabled_idx; |
| re_token_type_t type; |
| struct re_backref_cache_entry *entry; |
| node = candidates->elems[node_idx]; |
| type = dfa->nodes[node].type; |
| /* Avoid infinite loop for the REs like "()\1+". */ |
| if (node == sctx->last_node && str_idx == sctx->last_str_idx) |
| continue; |
| if (type != OP_BACK_REF) |
| continue; |
| |
| entry = mctx->bkref_ents + first_idx; |
| enabled_idx = first_idx; |
| do |
| { |
| int subexp_len; |
| int to_idx; |
| int dst_node; |
| int ret; |
| re_dfastate_t *cur_state; |
| |
| if (entry->node != node) |
| continue; |
| subexp_len = entry->subexp_to - entry->subexp_from; |
| to_idx = str_idx + subexp_len; |
| dst_node = (subexp_len ? dfa->nexts[node] |
| : dfa->edests[node].elems[0]); |
| |
| if (to_idx > sctx->last_str_idx |
| || sctx->sifted_states[to_idx] == NULL |
| || !STATE_NODE_CONTAINS (sctx->sifted_states[to_idx], dst_node) |
| || check_dst_limits (mctx, &sctx->limits, node, |
| str_idx, dst_node, to_idx)) |
| continue; |
| |
| if (local_sctx.sifted_states == NULL) |
| { |
| local_sctx = *sctx; |
| err = re_node_set_init_copy (&local_sctx.limits, &sctx->limits); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| local_sctx.last_node = node; |
| local_sctx.last_str_idx = str_idx; |
| ret = re_node_set_insert (&local_sctx.limits, enabled_idx); |
| if (BE (ret < 0, 0)) |
| { |
| err = REG_ESPACE; |
| goto free_return; |
| } |
| cur_state = local_sctx.sifted_states[str_idx]; |
| err = sift_states_backward (mctx, &local_sctx); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| if (sctx->limited_states != NULL) |
| { |
| err = merge_state_array (dfa, sctx->limited_states, |
| local_sctx.sifted_states, |
| str_idx + 1); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| local_sctx.sifted_states[str_idx] = cur_state; |
| re_node_set_remove (&local_sctx.limits, enabled_idx); |
| |
| /* mctx->bkref_ents may have changed, reload the pointer. */ |
| entry = mctx->bkref_ents + enabled_idx; |
| } |
| while (enabled_idx++, entry++->more); |
| } |
| err = REG_NOERROR; |
| free_return: |
| if (local_sctx.sifted_states != NULL) |
| { |
| re_node_set_free (&local_sctx.limits); |
| } |
| |
| return err; |
| } |
| |
| |
| #ifdef RE_ENABLE_I18N |
| static int |
| internal_function |
| sift_states_iter_mb (const re_match_context_t *mctx, re_sift_context_t *sctx, |
| int node_idx, int str_idx, int max_str_idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int naccepted; |
| /* Check the node can accept `multi byte'. */ |
| naccepted = check_node_accept_bytes (dfa, node_idx, &mctx->input, str_idx); |
| if (naccepted > 0 && str_idx + naccepted <= max_str_idx && |
| !STATE_NODE_CONTAINS (sctx->sifted_states[str_idx + naccepted], |
| dfa->nexts[node_idx])) |
| /* The node can't accept the `multi byte', or the |
| destination was already thrown away, then the node |
| couldn't accept the current input `multi byte'. */ |
| naccepted = 0; |
| /* Otherwise, it is sure that the node could accept |
| `naccepted' bytes input. */ |
| return naccepted; |
| } |
| #endif /* RE_ENABLE_I18N */ |
| |
| |
| /* Functions for state transition. */ |
| |
| /* Return the next state to which the current state STATE will transit by |
| accepting the current input byte, and update STATE_LOG if necessary. |
| If STATE can accept a multibyte char/collating element/back reference |
| update the destination of STATE_LOG. */ |
| |
| static re_dfastate_t * |
| internal_function |
| transit_state (reg_errcode_t *err, re_match_context_t *mctx, |
| re_dfastate_t *state) |
| { |
| re_dfastate_t **trtable; |
| unsigned char ch; |
| |
| #ifdef RE_ENABLE_I18N |
| /* If the current state can accept multibyte. */ |
| if (BE (state->accept_mb, 0)) |
| { |
| *err = transit_state_mb (mctx, state); |
| if (BE (*err != REG_NOERROR, 0)) |
| return NULL; |
| } |
| #endif /* RE_ENABLE_I18N */ |
| |
| /* Then decide the next state with the single byte. */ |
| #if 0 |
| if (0) |
| /* don't use transition table */ |
| return transit_state_sb (err, mctx, state); |
| #endif |
| |
| /* Use transition table */ |
| ch = re_string_fetch_byte (&mctx->input); |
| for (;;) |
| { |
| trtable = state->trtable; |
| if (BE (trtable != NULL, 1)) |
| return trtable[ch]; |
| |
| trtable = state->word_trtable; |
| if (BE (trtable != NULL, 1)) |
| { |
| unsigned int context; |
| context |
| = re_string_context_at (&mctx->input, |
| re_string_cur_idx (&mctx->input) - 1, |
| mctx->eflags); |
| if (IS_WORD_CONTEXT (context)) |
| return trtable[ch + SBC_MAX]; |
| else |
| return trtable[ch]; |
| } |
| |
| if (!build_trtable (mctx->dfa, state)) |
| { |
| *err = REG_ESPACE; |
| return NULL; |
| } |
| |
| /* Retry, we now have a transition table. */ |
| } |
| } |
| |
| /* Update the state_log if we need */ |
| static re_dfastate_t * |
| internal_function |
| merge_state_with_log (reg_errcode_t *err, re_match_context_t *mctx, |
| re_dfastate_t *next_state) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int cur_idx = re_string_cur_idx (&mctx->input); |
| |
| if (cur_idx > mctx->state_log_top) |
| { |
| mctx->state_log[cur_idx] = next_state; |
| mctx->state_log_top = cur_idx; |
| } |
| else if (mctx->state_log[cur_idx] == NULL) |
| { |
| mctx->state_log[cur_idx] = next_state; |
| } |
| else |
| { |
| re_dfastate_t *pstate; |
| unsigned int context; |
| re_node_set next_nodes, *log_nodes, *table_nodes = NULL; |
| /* If (state_log[cur_idx] != 0), it implies that cur_idx is |
| the destination of a multibyte char/collating element/ |
| back reference. Then the next state is the union set of |
| these destinations and the results of the transition table. */ |
| pstate = mctx->state_log[cur_idx]; |
| log_nodes = pstate->entrance_nodes; |
| if (next_state != NULL) |
| { |
| table_nodes = next_state->entrance_nodes; |
| *err = re_node_set_init_union (&next_nodes, table_nodes, |
| log_nodes); |
| if (BE (*err != REG_NOERROR, 0)) |
| return NULL; |
| } |
| else |
| next_nodes = *log_nodes; |
| /* Note: We already add the nodes of the initial state, |
| then we don't need to add them here. */ |
| |
| context = re_string_context_at (&mctx->input, |
| re_string_cur_idx (&mctx->input) - 1, |
| mctx->eflags); |
| next_state = mctx->state_log[cur_idx] |
| = re_acquire_state_context (err, dfa, &next_nodes, context); |
| /* We don't need to check errors here, since the return value of |
| this function is next_state and ERR is already set. */ |
| |
| if (table_nodes != NULL) |
| re_node_set_free (&next_nodes); |
| } |
| |
| if (BE (dfa->nbackref, 0) && next_state != NULL) |
| { |
| /* Check OP_OPEN_SUBEXP in the current state in case that we use them |
| later. We must check them here, since the back references in the |
| next state might use them. */ |
| *err = check_subexp_matching_top (mctx, &next_state->nodes, |
| cur_idx); |
| if (BE (*err != REG_NOERROR, 0)) |
| return NULL; |
| |
| /* If the next state has back references. */ |
| if (next_state->has_backref) |
| { |
| *err = transit_state_bkref (mctx, &next_state->nodes); |
| if (BE (*err != REG_NOERROR, 0)) |
| return NULL; |
| next_state = mctx->state_log[cur_idx]; |
| } |
| } |
| |
| return next_state; |
| } |
| |
| /* Skip bytes in the input that correspond to part of a |
| multi-byte match, then look in the log for a state |
| from which to restart matching. */ |
| static re_dfastate_t * |
| internal_function |
| find_recover_state (reg_errcode_t *err, re_match_context_t *mctx) |
| { |
| re_dfastate_t *cur_state; |
| do |
| { |
| int max = mctx->state_log_top; |
| int cur_str_idx = re_string_cur_idx (&mctx->input); |
| |
| do |
| { |
| if (++cur_str_idx > max) |
| return NULL; |
| re_string_skip_bytes (&mctx->input, 1); |
| } |
| while (mctx->state_log[cur_str_idx] == NULL); |
| |
| cur_state = merge_state_with_log (err, mctx, NULL); |
| } |
| while (*err == REG_NOERROR && cur_state == NULL); |
| return cur_state; |
| } |
| |
| /* Helper functions for transit_state. */ |
| |
| /* From the node set CUR_NODES, pick up the nodes whose types are |
| OP_OPEN_SUBEXP and which have corresponding back references in the regular |
| expression. And register them to use them later for evaluating the |
| corresponding back references. */ |
| |
| static reg_errcode_t |
| internal_function |
| check_subexp_matching_top (re_match_context_t *mctx, re_node_set *cur_nodes, |
| int str_idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int node_idx; |
| reg_errcode_t err; |
| |
| /* TODO: This isn't efficient. |
| Because there might be more than one nodes whose types are |
| OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all |
| nodes. |
| E.g. RE: (a){2} */ |
| for (node_idx = 0; node_idx < cur_nodes->nelem; ++node_idx) |
| { |
| int node = cur_nodes->elems[node_idx]; |
| if (dfa->nodes[node].type == OP_OPEN_SUBEXP |
| && dfa->nodes[node].opr.idx < BITSET_WORD_BITS |
| && (dfa->used_bkref_map |
| & ((bitset_word_t) 1 << dfa->nodes[node].opr.idx))) |
| { |
| err = match_ctx_add_subtop (mctx, node, str_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| } |
| return REG_NOERROR; |
| } |
| |
| #if 0 |
| /* Return the next state to which the current state STATE will transit by |
| accepting the current input byte. */ |
| |
| static re_dfastate_t * |
| transit_state_sb (reg_errcode_t *err, re_match_context_t *mctx, |
| re_dfastate_t *state) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| re_node_set next_nodes; |
| re_dfastate_t *next_state; |
| int node_cnt, cur_str_idx = re_string_cur_idx (&mctx->input); |
| unsigned int context; |
| |
| *err = re_node_set_alloc (&next_nodes, state->nodes.nelem + 1); |
| if (BE (*err != REG_NOERROR, 0)) |
| return NULL; |
| for (node_cnt = 0; node_cnt < state->nodes.nelem; ++node_cnt) |
| { |
| int cur_node = state->nodes.elems[node_cnt]; |
| if (check_node_accept (mctx, dfa->nodes + cur_node, cur_str_idx)) |
| { |
| *err = re_node_set_merge (&next_nodes, |
| dfa->eclosures + dfa->nexts[cur_node]); |
| if (BE (*err != REG_NOERROR, 0)) |
| { |
| re_node_set_free (&next_nodes); |
| return NULL; |
| } |
| } |
| } |
| context = re_string_context_at (&mctx->input, cur_str_idx, mctx->eflags); |
| next_state = re_acquire_state_context (err, dfa, &next_nodes, context); |
| /* We don't need to check errors here, since the return value of |
| this function is next_state and ERR is already set. */ |
| |
| re_node_set_free (&next_nodes); |
| re_string_skip_bytes (&mctx->input, 1); |
| return next_state; |
| } |
| #endif |
| |
| #ifdef RE_ENABLE_I18N |
| static reg_errcode_t |
| internal_function |
| transit_state_mb (re_match_context_t *mctx, re_dfastate_t *pstate) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err; |
| int i; |
| |
| for (i = 0; i < pstate->nodes.nelem; ++i) |
| { |
| re_node_set dest_nodes, *new_nodes; |
| int cur_node_idx = pstate->nodes.elems[i]; |
| int naccepted, dest_idx; |
| unsigned int context; |
| re_dfastate_t *dest_state; |
| |
| if (!dfa->nodes[cur_node_idx].accept_mb) |
| continue; |
| |
| if (dfa->nodes[cur_node_idx].constraint) |
| { |
| context = re_string_context_at (&mctx->input, |
| re_string_cur_idx (&mctx->input), |
| mctx->eflags); |
| if (NOT_SATISFY_NEXT_CONSTRAINT (dfa->nodes[cur_node_idx].constraint, |
| context)) |
| continue; |
| } |
| |
| /* How many bytes the node can accept? */ |
| naccepted = check_node_accept_bytes (dfa, cur_node_idx, &mctx->input, |
| re_string_cur_idx (&mctx->input)); |
| if (naccepted == 0) |
| continue; |
| |
| /* The node can accepts `naccepted' bytes. */ |
| dest_idx = re_string_cur_idx (&mctx->input) + naccepted; |
| mctx->max_mb_elem_len = ((mctx->max_mb_elem_len < naccepted) ? naccepted |
| : mctx->max_mb_elem_len); |
| err = clean_state_log_if_needed (mctx, dest_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| #ifdef DEBUG |
| assert (dfa->nexts[cur_node_idx] != -1); |
| #endif |
| new_nodes = dfa->eclosures + dfa->nexts[cur_node_idx]; |
| |
| dest_state = mctx->state_log[dest_idx]; |
| if (dest_state == NULL) |
| dest_nodes = *new_nodes; |
| else |
| { |
| err = re_node_set_init_union (&dest_nodes, |
| dest_state->entrance_nodes, new_nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| context = re_string_context_at (&mctx->input, dest_idx - 1, |
| mctx->eflags); |
| mctx->state_log[dest_idx] |
| = re_acquire_state_context (&err, dfa, &dest_nodes, context); |
| if (dest_state != NULL) |
| re_node_set_free (&dest_nodes); |
| if (BE (mctx->state_log[dest_idx] == NULL && err != REG_NOERROR, 0)) |
| return err; |
| } |
| return REG_NOERROR; |
| } |
| #endif /* RE_ENABLE_I18N */ |
| |
| static reg_errcode_t |
| internal_function |
| transit_state_bkref (re_match_context_t *mctx, const re_node_set *nodes) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err; |
| int i; |
| int cur_str_idx = re_string_cur_idx (&mctx->input); |
| |
| for (i = 0; i < nodes->nelem; ++i) |
| { |
| int dest_str_idx, prev_nelem, bkc_idx; |
| int node_idx = nodes->elems[i]; |
| unsigned int context; |
| const re_token_t *node = dfa->nodes + node_idx; |
| re_node_set *new_dest_nodes; |
| |
| /* Check whether `node' is a backreference or not. */ |
| if (node->type != OP_BACK_REF) |
| continue; |
| |
| if (node->constraint) |
| { |
| context = re_string_context_at (&mctx->input, cur_str_idx, |
| mctx->eflags); |
| if (NOT_SATISFY_NEXT_CONSTRAINT (node->constraint, context)) |
| continue; |
| } |
| |
| /* `node' is a backreference. |
| Check the substring which the substring matched. */ |
| bkc_idx = mctx->nbkref_ents; |
| err = get_subexp (mctx, node_idx, cur_str_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| |
| /* And add the epsilon closures (which is `new_dest_nodes') of |
| the backreference to appropriate state_log. */ |
| #ifdef DEBUG |
| assert (dfa->nexts[node_idx] != -1); |
| #endif |
| for (; bkc_idx < mctx->nbkref_ents; ++bkc_idx) |
| { |
| int subexp_len; |
| re_dfastate_t *dest_state; |
| struct re_backref_cache_entry *bkref_ent; |
| bkref_ent = mctx->bkref_ents + bkc_idx; |
| if (bkref_ent->node != node_idx || bkref_ent->str_idx != cur_str_idx) |
| continue; |
| subexp_len = bkref_ent->subexp_to - bkref_ent->subexp_from; |
| new_dest_nodes = (subexp_len == 0 |
| ? dfa->eclosures + dfa->edests[node_idx].elems[0] |
| : dfa->eclosures + dfa->nexts[node_idx]); |
| dest_str_idx = (cur_str_idx + bkref_ent->subexp_to |
| - bkref_ent->subexp_from); |
| context = re_string_context_at (&mctx->input, dest_str_idx - 1, |
| mctx->eflags); |
| dest_state = mctx->state_log[dest_str_idx]; |
| prev_nelem = ((mctx->state_log[cur_str_idx] == NULL) ? 0 |
| : mctx->state_log[cur_str_idx]->nodes.nelem); |
| /* Add `new_dest_node' to state_log. */ |
| if (dest_state == NULL) |
| { |
| mctx->state_log[dest_str_idx] |
| = re_acquire_state_context (&err, dfa, new_dest_nodes, |
| context); |
| if (BE (mctx->state_log[dest_str_idx] == NULL |
| && err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| else |
| { |
| re_node_set dest_nodes; |
| err = re_node_set_init_union (&dest_nodes, |
| dest_state->entrance_nodes, |
| new_dest_nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| { |
| re_node_set_free (&dest_nodes); |
| goto free_return; |
| } |
| mctx->state_log[dest_str_idx] |
| = re_acquire_state_context (&err, dfa, &dest_nodes, context); |
| re_node_set_free (&dest_nodes); |
| if (BE (mctx->state_log[dest_str_idx] == NULL |
| && err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| /* We need to check recursively if the backreference can epsilon |
| transit. */ |
| if (subexp_len == 0 |
| && mctx->state_log[cur_str_idx]->nodes.nelem > prev_nelem) |
| { |
| err = check_subexp_matching_top (mctx, new_dest_nodes, |
| cur_str_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| err = transit_state_bkref (mctx, new_dest_nodes); |
| if (BE (err != REG_NOERROR, 0)) |
| goto free_return; |
| } |
| } |
| } |
| err = REG_NOERROR; |
| free_return: |
| return err; |
| } |
| |
| /* Enumerate all the candidates which the backreference BKREF_NODE can match |
| at BKREF_STR_IDX, and register them by match_ctx_add_entry(). |
| Note that we might collect inappropriate candidates here. |
| However, the cost of checking them strictly here is too high, then we |
| delay these checking for prune_impossible_nodes(). */ |
| |
| static reg_errcode_t |
| internal_function |
| get_subexp (re_match_context_t *mctx, int bkref_node, int bkref_str_idx) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| int subexp_num, sub_top_idx; |
| const char *buf = (const char *) re_string_get_buffer (&mctx->input); |
| /* Return if we have already checked BKREF_NODE at BKREF_STR_IDX. */ |
| int cache_idx = search_cur_bkref_entry (mctx, bkref_str_idx); |
| if (cache_idx != -1) |
| { |
| const struct re_backref_cache_entry *entry |
| = mctx->bkref_ents + cache_idx; |
| do |
| if (entry->node == bkref_node) |
| return REG_NOERROR; /* We already checked it. */ |
| while (entry++->more); |
| } |
| |
| subexp_num = dfa->nodes[bkref_node].opr.idx; |
| |
| /* For each sub expression */ |
| for (sub_top_idx = 0; sub_top_idx < mctx->nsub_tops; ++sub_top_idx) |
| { |
| reg_errcode_t err; |
| re_sub_match_top_t *sub_top = mctx->sub_tops[sub_top_idx]; |
| re_sub_match_last_t *sub_last; |
| int sub_last_idx, sl_str, bkref_str_off; |
| |
| if (dfa->nodes[sub_top->node].opr.idx != subexp_num) |
| continue; /* It isn't related. */ |
| |
| sl_str = sub_top->str_idx; |
| bkref_str_off = bkref_str_idx; |
| /* At first, check the last node of sub expressions we already |
| evaluated. */ |
| for (sub_last_idx = 0; sub_last_idx < sub_top->nlasts; ++sub_last_idx) |
| { |
| int sl_str_diff; |
| sub_last = sub_top->lasts[sub_last_idx]; |
| sl_str_diff = sub_last->str_idx - sl_str; |
| /* The matched string by the sub expression match with the substring |
| at the back reference? */ |
| if (sl_str_diff > 0) |
| { |
| if (BE (bkref_str_off + sl_str_diff > mctx->input.valid_len, 0)) |
| { |
| /* Not enough chars for a successful match. */ |
| if (bkref_str_off + sl_str_diff > mctx->input.len) |
| break; |
| |
| err = clean_state_log_if_needed (mctx, |
| bkref_str_off |
| + sl_str_diff); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| buf = (const char *) re_string_get_buffer (&mctx->input); |
| } |
| if (memcmp (buf + bkref_str_off, buf + sl_str, sl_str_diff) != 0) |
| /* We don't need to search this sub expression any more. */ |
| break; |
| } |
| bkref_str_off += sl_str_diff; |
| sl_str += sl_str_diff; |
| err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node, |
| bkref_str_idx); |
| |
| /* Reload buf, since the preceding call might have reallocated |
| the buffer. */ |
| buf = (const char *) re_string_get_buffer (&mctx->input); |
| |
| if (err == REG_NOMATCH) |
| continue; |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| } |
| |
| if (sub_last_idx < sub_top->nlasts) |
| continue; |
| if (sub_last_idx > 0) |
| ++sl_str; |
| /* Then, search for the other last nodes of the sub expression. */ |
| for (; sl_str <= bkref_str_idx; ++sl_str) |
| { |
| int cls_node, sl_str_off; |
| const re_node_set *nodes; |
| sl_str_off = sl_str - sub_top->str_idx; |
| /* The matched string by the sub expression match with the substring |
| at the back reference? */ |
| if (sl_str_off > 0) |
| { |
| if (BE (bkref_str_off >= mctx->input.valid_len, 0)) |
| { |
| /* If we are at the end of the input, we cannot match. */ |
| if (bkref_str_off >= mctx->input.len) |
| break; |
| |
| err = extend_buffers (mctx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| |
| buf = (const char *) re_string_get_buffer (&mctx->input); |
| } |
| if (buf [bkref_str_off++] != buf[sl_str - 1]) |
| break; /* We don't need to search this sub expression |
| any more. */ |
| } |
| if (mctx->state_log[sl_str] == NULL) |
| continue; |
| /* Does this state have a ')' of the sub expression? */ |
| nodes = &mctx->state_log[sl_str]->nodes; |
| cls_node = find_subexp_node (dfa, nodes, subexp_num, |
| OP_CLOSE_SUBEXP); |
| if (cls_node == -1) |
| continue; /* No. */ |
| if (sub_top->path == NULL) |
| { |
| sub_top->path = calloc (sizeof (state_array_t), |
| sl_str - sub_top->str_idx + 1); |
| if (sub_top->path == NULL) |
| return REG_ESPACE; |
| } |
| /* Can the OP_OPEN_SUBEXP node arrive the OP_CLOSE_SUBEXP node |
| in the current context? */ |
| err = check_arrival (mctx, sub_top->path, sub_top->node, |
| sub_top->str_idx, cls_node, sl_str, |
| OP_CLOSE_SUBEXP); |
| if (err == REG_NOMATCH) |
| continue; |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| sub_last = match_ctx_add_sublast (sub_top, cls_node, sl_str); |
| if (BE (sub_last == NULL, 0)) |
| return REG_ESPACE; |
| err = get_subexp_sub (mctx, sub_top, sub_last, bkref_node, |
| bkref_str_idx); |
| if (err == REG_NOMATCH) |
| continue; |
| } |
| } |
| return REG_NOERROR; |
| } |
| |
| /* Helper functions for get_subexp(). */ |
| |
| /* Check SUB_LAST can arrive to the back reference BKREF_NODE at BKREF_STR. |
| If it can arrive, register the sub expression expressed with SUB_TOP |
| and SUB_LAST. */ |
| |
| static reg_errcode_t |
| internal_function |
| get_subexp_sub (re_match_context_t *mctx, const re_sub_match_top_t *sub_top, |
| re_sub_match_last_t *sub_last, int bkref_node, int bkref_str) |
| { |
| reg_errcode_t err; |
| int to_idx; |
| /* Can the subexpression arrive the back reference? */ |
| err = check_arrival (mctx, &sub_last->path, sub_last->node, |
| sub_last->str_idx, bkref_node, bkref_str, |
| OP_OPEN_SUBEXP); |
| if (err != REG_NOERROR) |
| return err; |
| err = match_ctx_add_entry (mctx, bkref_node, bkref_str, sub_top->str_idx, |
| sub_last->str_idx); |
| if (BE (err != REG_NOERROR, 0)) |
| return err; |
| to_idx = bkref_str + sub_last->str_idx - sub_top->str_idx; |
| return clean_state_log_if_needed (mctx, to_idx); |
| } |
| |
| /* Find the first node which is '(' or ')' and whose index is SUBEXP_IDX. |
| Search '(' if FL_OPEN, or search ')' otherwise. |
| TODO: This function isn't efficient... |
| Because there might be more than one nodes whose types are |
| OP_OPEN_SUBEXP and whose index is SUBEXP_IDX, we must check all |
| nodes. |
| E.g. RE: (a){2} */ |
| |
| static int |
| internal_function |
| find_subexp_node (const re_dfa_t *dfa, const re_node_set *nodes, |
| int subexp_idx, int type) |
| { |
| int cls_idx; |
| for (cls_idx = 0; cls_idx < nodes->nelem; ++cls_idx) |
| { |
| int cls_node = nodes->elems[cls_idx]; |
| const re_token_t *node = dfa->nodes + cls_node; |
| if (node->type == type |
| && node->opr.idx == subexp_idx) |
| return cls_node; |
| } |
| return -1; |
| } |
| |
| /* Check whether the node TOP_NODE at TOP_STR can arrive to the node |
| LAST_NODE at LAST_STR. We record the path onto PATH since it will be |
| heavily reused. |
| Return REG_NOERROR if it can arrive, or REG_NOMATCH otherwise. */ |
| |
| static reg_errcode_t |
| internal_function |
| check_arrival (re_match_context_t *mctx, state_array_t *path, int top_node, |
| int top_str, int last_node, int last_str, int type) |
| { |
| const re_dfa_t *const dfa = mctx->dfa; |
| reg_errcode_t err = REG_NOERROR; |
| int subexp_num, backup_cur_idx, str_idx, null_cnt; |
| re_dfastate_t *cur_state = NULL; |
| re_node_set *cur_nodes, next_nodes; |
| re_dfastate_t **backup_state_log; |
| unsigned int context; |
| |
| subexp_num = dfa->nodes[top_node].opr.idx; |
| /* Extend the buffer if we need. */ |
| if (BE (path->alloc < last_str + mctx->max_mb_elem_len + 1, 0)) |
| { |
| re_dfastate_t **new_array; |
| int old_alloc = path->alloc; |
| path->alloc += last_str + mctx->max_mb_elem_len + 1; |
| new_array = re_realloc (path->array, re_dfastate_t *, path->alloc); |
| if (BE (new_array == NULL, 0)) |
| { |
| path->alloc = old_alloc; |
| return REG_ESPACE; |
| } |
| path->array = new_array; |
| memset (new_array + old_alloc, '\0', |
| sizeof (re_dfastate_t *) * (path->alloc - old_alloc)); |
| } |
| |
| str_idx = path->next_idx ? path->next_idx : top_str; |
| |