| /* |
| regexec.c - TRE POSIX compatible matching functions (and more). |
| |
| Copyright (c) 2001-2009 Ville Laurikari <vl@iki.fi> |
| All rights reserved. |
| |
| Redistribution and use in source and binary forms, with or without |
| modification, are permitted provided that the following conditions |
| are met: |
| |
| 1. Redistributions of source code must retain the above copyright |
| notice, this list of conditions and the following disclaimer. |
| |
| 2. Redistributions in binary form must reproduce the above copyright |
| notice, this list of conditions and the following disclaimer in the |
| documentation and/or other materials provided with the distribution. |
| |
| THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDER AND CONTRIBUTORS |
| ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT |
| LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR |
| A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT |
| HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, |
| SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT |
| LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, |
| DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY |
| THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT |
| (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE |
| OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. |
| |
| */ |
| |
| #include <stdlib.h> |
| #include <string.h> |
| #include <wchar.h> |
| #include <wctype.h> |
| #include <limits.h> |
| #include <stdint.h> |
| |
| #include <regex.h> |
| |
| #include "tre.h" |
| |
| #include <assert.h> |
| |
| static void |
| tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags, |
| const tre_tnfa_t *tnfa, regoff_t *tags, regoff_t match_eo); |
| |
| /*********************************************************************** |
| from tre-match-utils.h |
| ***********************************************************************/ |
| |
| #define GET_NEXT_WCHAR() do { \ |
| prev_c = next_c; pos += pos_add_next; \ |
| if ((pos_add_next = mbtowc(&next_c, str_byte, MB_LEN_MAX)) <= 0) { \ |
| if (pos_add_next < 0) { ret = REG_NOMATCH; goto error_exit; } \ |
| else pos_add_next++; \ |
| } \ |
| str_byte += pos_add_next; \ |
| } while (0) |
| |
| #define IS_WORD_CHAR(c) ((c) == L'_' || tre_isalnum(c)) |
| |
| #define CHECK_ASSERTIONS(assertions) \ |
| (((assertions & ASSERT_AT_BOL) \ |
| && (pos > 0 || reg_notbol) \ |
| && (prev_c != L'\n' || !reg_newline)) \ |
| || ((assertions & ASSERT_AT_EOL) \ |
| && (next_c != L'\0' || reg_noteol) \ |
| && (next_c != L'\n' || !reg_newline)) \ |
| || ((assertions & ASSERT_AT_BOW) \ |
| && (IS_WORD_CHAR(prev_c) || !IS_WORD_CHAR(next_c))) \ |
| || ((assertions & ASSERT_AT_EOW) \ |
| && (!IS_WORD_CHAR(prev_c) || IS_WORD_CHAR(next_c))) \ |
| || ((assertions & ASSERT_AT_WB) \ |
| && (pos != 0 && next_c != L'\0' \ |
| && IS_WORD_CHAR(prev_c) == IS_WORD_CHAR(next_c))) \ |
| || ((assertions & ASSERT_AT_WB_NEG) \ |
| && (pos == 0 || next_c == L'\0' \ |
| || IS_WORD_CHAR(prev_c) != IS_WORD_CHAR(next_c)))) |
| |
| #define CHECK_CHAR_CLASSES(trans_i, tnfa, eflags) \ |
| (((trans_i->assertions & ASSERT_CHAR_CLASS) \ |
| && !(tnfa->cflags & REG_ICASE) \ |
| && !tre_isctype((tre_cint_t)prev_c, trans_i->u.class)) \ |
| || ((trans_i->assertions & ASSERT_CHAR_CLASS) \ |
| && (tnfa->cflags & REG_ICASE) \ |
| && !tre_isctype(tre_tolower((tre_cint_t)prev_c),trans_i->u.class) \ |
| && !tre_isctype(tre_toupper((tre_cint_t)prev_c),trans_i->u.class)) \ |
| || ((trans_i->assertions & ASSERT_CHAR_CLASS_NEG) \ |
| && tre_neg_char_classes_match(trans_i->neg_classes,(tre_cint_t)prev_c,\ |
| tnfa->cflags & REG_ICASE))) |
| |
| |
| |
| |
| /* Returns 1 if `t1' wins `t2', 0 otherwise. */ |
| static int |
| tre_tag_order(int num_tags, tre_tag_direction_t *tag_directions, |
| regoff_t *t1, regoff_t *t2) |
| { |
| int i; |
| for (i = 0; i < num_tags; i++) |
| { |
| if (tag_directions[i] == TRE_TAG_MINIMIZE) |
| { |
| if (t1[i] < t2[i]) |
| return 1; |
| if (t1[i] > t2[i]) |
| return 0; |
| } |
| else |
| { |
| if (t1[i] > t2[i]) |
| return 1; |
| if (t1[i] < t2[i]) |
| return 0; |
| } |
| } |
| /* assert(0);*/ |
| return 0; |
| } |
| |
| static int |
| tre_neg_char_classes_match(tre_ctype_t *classes, tre_cint_t wc, int icase) |
| { |
| while (*classes != (tre_ctype_t)0) |
| if ((!icase && tre_isctype(wc, *classes)) |
| || (icase && (tre_isctype(tre_toupper(wc), *classes) |
| || tre_isctype(tre_tolower(wc), *classes)))) |
| return 1; /* Match. */ |
| else |
| classes++; |
| return 0; /* No match. */ |
| } |
| |
| |
| /*********************************************************************** |
| from tre-match-parallel.c |
| ***********************************************************************/ |
| |
| /* |
| This algorithm searches for matches basically by reading characters |
| in the searched string one by one, starting at the beginning. All |
| matching paths in the TNFA are traversed in parallel. When two or |
| more paths reach the same state, exactly one is chosen according to |
| tag ordering rules; if returning submatches is not required it does |
| not matter which path is chosen. |
| |
| The worst case time required for finding the leftmost and longest |
| match, or determining that there is no match, is always linearly |
| dependent on the length of the text being searched. |
| |
| This algorithm cannot handle TNFAs with back referencing nodes. |
| See `tre-match-backtrack.c'. |
| */ |
| |
| typedef struct { |
| tre_tnfa_transition_t *state; |
| regoff_t *tags; |
| } tre_tnfa_reach_t; |
| |
| typedef struct { |
| regoff_t pos; |
| regoff_t **tags; |
| } tre_reach_pos_t; |
| |
| |
| static reg_errcode_t |
| tre_tnfa_run_parallel(const tre_tnfa_t *tnfa, const void *string, |
| regoff_t *match_tags, int eflags, |
| regoff_t *match_end_ofs) |
| { |
| /* State variables required by GET_NEXT_WCHAR. */ |
| tre_char_t prev_c = 0, next_c = 0; |
| const char *str_byte = string; |
| regoff_t pos = -1; |
| regoff_t pos_add_next = 1; |
| #ifdef TRE_MBSTATE |
| mbstate_t mbstate; |
| #endif /* TRE_MBSTATE */ |
| int reg_notbol = eflags & REG_NOTBOL; |
| int reg_noteol = eflags & REG_NOTEOL; |
| int reg_newline = tnfa->cflags & REG_NEWLINE; |
| reg_errcode_t ret; |
| |
| char *buf; |
| tre_tnfa_transition_t *trans_i; |
| tre_tnfa_reach_t *reach, *reach_next, *reach_i, *reach_next_i; |
| tre_reach_pos_t *reach_pos; |
| int *tag_i; |
| int num_tags, i; |
| |
| regoff_t match_eo = -1; /* end offset of match (-1 if no match found yet) */ |
| int new_match = 0; |
| regoff_t *tmp_tags = NULL; |
| regoff_t *tmp_iptr; |
| |
| #ifdef TRE_MBSTATE |
| memset(&mbstate, '\0', sizeof(mbstate)); |
| #endif /* TRE_MBSTATE */ |
| |
| if (!match_tags) |
| num_tags = 0; |
| else |
| num_tags = tnfa->num_tags; |
| |
| /* Allocate memory for temporary data required for matching. This needs to |
| be done for every matching operation to be thread safe. This allocates |
| everything in a single large block with calloc(). */ |
| { |
| size_t tbytes, rbytes, pbytes, xbytes, total_bytes; |
| char *tmp_buf; |
| |
| /* Ensure that tbytes and xbytes*num_states cannot overflow, and that |
| * they don't contribute more than 1/8 of SIZE_MAX to total_bytes. */ |
| if (num_tags > SIZE_MAX/(8 * sizeof(regoff_t) * tnfa->num_states)) |
| return REG_ESPACE; |
| |
| /* Likewise check rbytes. */ |
| if (tnfa->num_states+1 > SIZE_MAX/(8 * sizeof(*reach_next))) |
| return REG_ESPACE; |
| |
| /* Likewise check pbytes. */ |
| if (tnfa->num_states > SIZE_MAX/(8 * sizeof(*reach_pos))) |
| return REG_ESPACE; |
| |
| /* Compute the length of the block we need. */ |
| tbytes = sizeof(*tmp_tags) * num_tags; |
| rbytes = sizeof(*reach_next) * (tnfa->num_states + 1); |
| pbytes = sizeof(*reach_pos) * tnfa->num_states; |
| xbytes = sizeof(regoff_t) * num_tags; |
| total_bytes = |
| (sizeof(long) - 1) * 4 /* for alignment paddings */ |
| + (rbytes + xbytes * tnfa->num_states) * 2 + tbytes + pbytes; |
| |
| /* Allocate the memory. */ |
| buf = calloc(total_bytes, 1); |
| if (buf == NULL) |
| return REG_ESPACE; |
| |
| /* Get the various pointers within tmp_buf (properly aligned). */ |
| tmp_tags = (void *)buf; |
| tmp_buf = buf + tbytes; |
| tmp_buf += ALIGN(tmp_buf, long); |
| reach_next = (void *)tmp_buf; |
| tmp_buf += rbytes; |
| tmp_buf += ALIGN(tmp_buf, long); |
| reach = (void *)tmp_buf; |
| tmp_buf += rbytes; |
| tmp_buf += ALIGN(tmp_buf, long); |
| reach_pos = (void *)tmp_buf; |
| tmp_buf += pbytes; |
| tmp_buf += ALIGN(tmp_buf, long); |
| for (i = 0; i < tnfa->num_states; i++) |
| { |
| reach[i].tags = (void *)tmp_buf; |
| tmp_buf += xbytes; |
| reach_next[i].tags = (void *)tmp_buf; |
| tmp_buf += xbytes; |
| } |
| } |
| |
| for (i = 0; i < tnfa->num_states; i++) |
| reach_pos[i].pos = -1; |
| |
| GET_NEXT_WCHAR(); |
| pos = 0; |
| |
| reach_next_i = reach_next; |
| while (1) |
| { |
| /* If no match found yet, add the initial states to `reach_next'. */ |
| if (match_eo < 0) |
| { |
| trans_i = tnfa->initial; |
| while (trans_i->state != NULL) |
| { |
| if (reach_pos[trans_i->state_id].pos < pos) |
| { |
| if (trans_i->assertions |
| && CHECK_ASSERTIONS(trans_i->assertions)) |
| { |
| trans_i++; |
| continue; |
| } |
| |
| reach_next_i->state = trans_i->state; |
| for (i = 0; i < num_tags; i++) |
| reach_next_i->tags[i] = -1; |
| tag_i = trans_i->tags; |
| if (tag_i) |
| while (*tag_i >= 0) |
| { |
| if (*tag_i < num_tags) |
| reach_next_i->tags[*tag_i] = pos; |
| tag_i++; |
| } |
| if (reach_next_i->state == tnfa->final) |
| { |
| match_eo = pos; |
| new_match = 1; |
| for (i = 0; i < num_tags; i++) |
| match_tags[i] = reach_next_i->tags[i]; |
| } |
| reach_pos[trans_i->state_id].pos = pos; |
| reach_pos[trans_i->state_id].tags = &reach_next_i->tags; |
| reach_next_i++; |
| } |
| trans_i++; |
| } |
| reach_next_i->state = NULL; |
| } |
| else |
| { |
| if (num_tags == 0 || reach_next_i == reach_next) |
| /* We have found a match. */ |
| break; |
| } |
| |
| /* Check for end of string. */ |
| if (!next_c) break; |
| |
| GET_NEXT_WCHAR(); |
| |
| /* Swap `reach' and `reach_next'. */ |
| reach_i = reach; |
| reach = reach_next; |
| reach_next = reach_i; |
| |
| /* For each state in `reach', weed out states that don't fulfill the |
| minimal matching conditions. */ |
| if (tnfa->num_minimals && new_match) |
| { |
| new_match = 0; |
| reach_next_i = reach_next; |
| for (reach_i = reach; reach_i->state; reach_i++) |
| { |
| int skip = 0; |
| for (i = 0; tnfa->minimal_tags[i] >= 0; i += 2) |
| { |
| int end = tnfa->minimal_tags[i]; |
| int start = tnfa->minimal_tags[i + 1]; |
| if (end >= num_tags) |
| { |
| skip = 1; |
| break; |
| } |
| else if (reach_i->tags[start] == match_tags[start] |
| && reach_i->tags[end] < match_tags[end]) |
| { |
| skip = 1; |
| break; |
| } |
| } |
| if (!skip) |
| { |
| reach_next_i->state = reach_i->state; |
| tmp_iptr = reach_next_i->tags; |
| reach_next_i->tags = reach_i->tags; |
| reach_i->tags = tmp_iptr; |
| reach_next_i++; |
| } |
| } |
| reach_next_i->state = NULL; |
| |
| /* Swap `reach' and `reach_next'. */ |
| reach_i = reach; |
| reach = reach_next; |
| reach_next = reach_i; |
| } |
| |
| /* For each state in `reach' see if there is a transition leaving with |
| the current input symbol to a state not yet in `reach_next', and |
| add the destination states to `reach_next'. */ |
| reach_next_i = reach_next; |
| for (reach_i = reach; reach_i->state; reach_i++) |
| { |
| for (trans_i = reach_i->state; trans_i->state; trans_i++) |
| { |
| /* Does this transition match the input symbol? */ |
| if (trans_i->code_min <= (tre_cint_t)prev_c && |
| trans_i->code_max >= (tre_cint_t)prev_c) |
| { |
| if (trans_i->assertions |
| && (CHECK_ASSERTIONS(trans_i->assertions) |
| || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags))) |
| { |
| continue; |
| } |
| |
| /* Compute the tags after this transition. */ |
| for (i = 0; i < num_tags; i++) |
| tmp_tags[i] = reach_i->tags[i]; |
| tag_i = trans_i->tags; |
| if (tag_i != NULL) |
| while (*tag_i >= 0) |
| { |
| if (*tag_i < num_tags) |
| tmp_tags[*tag_i] = pos; |
| tag_i++; |
| } |
| |
| if (reach_pos[trans_i->state_id].pos < pos) |
| { |
| /* Found an unvisited node. */ |
| reach_next_i->state = trans_i->state; |
| tmp_iptr = reach_next_i->tags; |
| reach_next_i->tags = tmp_tags; |
| tmp_tags = tmp_iptr; |
| reach_pos[trans_i->state_id].pos = pos; |
| reach_pos[trans_i->state_id].tags = &reach_next_i->tags; |
| |
| if (reach_next_i->state == tnfa->final |
| && (match_eo == -1 |
| || (num_tags > 0 |
| && reach_next_i->tags[0] <= match_tags[0]))) |
| { |
| match_eo = pos; |
| new_match = 1; |
| for (i = 0; i < num_tags; i++) |
| match_tags[i] = reach_next_i->tags[i]; |
| } |
| reach_next_i++; |
| |
| } |
| else |
| { |
| assert(reach_pos[trans_i->state_id].pos == pos); |
| /* Another path has also reached this state. We choose |
| the winner by examining the tag values for both |
| paths. */ |
| if (tre_tag_order(num_tags, tnfa->tag_directions, |
| tmp_tags, |
| *reach_pos[trans_i->state_id].tags)) |
| { |
| /* The new path wins. */ |
| tmp_iptr = *reach_pos[trans_i->state_id].tags; |
| *reach_pos[trans_i->state_id].tags = tmp_tags; |
| if (trans_i->state == tnfa->final) |
| { |
| match_eo = pos; |
| new_match = 1; |
| for (i = 0; i < num_tags; i++) |
| match_tags[i] = tmp_tags[i]; |
| } |
| tmp_tags = tmp_iptr; |
| } |
| } |
| } |
| } |
| } |
| reach_next_i->state = NULL; |
| } |
| |
| *match_end_ofs = match_eo; |
| ret = match_eo >= 0 ? REG_OK : REG_NOMATCH; |
| error_exit: |
| xfree(buf); |
| return ret; |
| } |
| |
| |
| |
| /*********************************************************************** |
| from tre-match-backtrack.c |
| ***********************************************************************/ |
| |
| /* |
| This matcher is for regexps that use back referencing. Regexp matching |
| with back referencing is an NP-complete problem on the number of back |
| references. The easiest way to match them is to use a backtracking |
| routine which basically goes through all possible paths in the TNFA |
| and chooses the one which results in the best (leftmost and longest) |
| match. This can be spectacularly expensive and may run out of stack |
| space, but there really is no better known generic algorithm. Quoting |
| Henry Spencer from comp.compilers: |
| <URL: http://compilers.iecc.com/comparch/article/93-03-102> |
| |
| POSIX.2 REs require longest match, which is really exciting to |
| implement since the obsolete ("basic") variant also includes |
| \<digit>. I haven't found a better way of tackling this than doing |
| a preliminary match using a DFA (or simulation) on a modified RE |
| that just replicates subREs for \<digit>, and then doing a |
| backtracking match to determine whether the subRE matches were |
| right. This can be rather slow, but I console myself with the |
| thought that people who use \<digit> deserve very slow execution. |
| (Pun unintentional but very appropriate.) |
| |
| */ |
| |
| typedef struct { |
| regoff_t pos; |
| const char *str_byte; |
| tre_tnfa_transition_t *state; |
| int state_id; |
| int next_c; |
| regoff_t *tags; |
| #ifdef TRE_MBSTATE |
| mbstate_t mbstate; |
| #endif /* TRE_MBSTATE */ |
| } tre_backtrack_item_t; |
| |
| typedef struct tre_backtrack_struct { |
| tre_backtrack_item_t item; |
| struct tre_backtrack_struct *prev; |
| struct tre_backtrack_struct *next; |
| } *tre_backtrack_t; |
| |
| #ifdef TRE_MBSTATE |
| #define BT_STACK_MBSTATE_IN stack->item.mbstate = (mbstate) |
| #define BT_STACK_MBSTATE_OUT (mbstate) = stack->item.mbstate |
| #else /* !TRE_MBSTATE */ |
| #define BT_STACK_MBSTATE_IN |
| #define BT_STACK_MBSTATE_OUT |
| #endif /* !TRE_MBSTATE */ |
| |
| #define tre_bt_mem_new tre_mem_new |
| #define tre_bt_mem_alloc tre_mem_alloc |
| #define tre_bt_mem_destroy tre_mem_destroy |
| |
| |
| #define BT_STACK_PUSH(_pos, _str_byte, _str_wide, _state, _state_id, _next_c, _tags, _mbstate) \ |
| do \ |
| { \ |
| int i; \ |
| if (!stack->next) \ |
| { \ |
| tre_backtrack_t s; \ |
| s = tre_bt_mem_alloc(mem, sizeof(*s)); \ |
| if (!s) \ |
| { \ |
| tre_bt_mem_destroy(mem); \ |
| if (tags) \ |
| xfree(tags); \ |
| if (pmatch) \ |
| xfree(pmatch); \ |
| if (states_seen) \ |
| xfree(states_seen); \ |
| return REG_ESPACE; \ |
| } \ |
| s->prev = stack; \ |
| s->next = NULL; \ |
| s->item.tags = tre_bt_mem_alloc(mem, \ |
| sizeof(*tags) * tnfa->num_tags); \ |
| if (!s->item.tags) \ |
| { \ |
| tre_bt_mem_destroy(mem); \ |
| if (tags) \ |
| xfree(tags); \ |
| if (pmatch) \ |
| xfree(pmatch); \ |
| if (states_seen) \ |
| xfree(states_seen); \ |
| return REG_ESPACE; \ |
| } \ |
| stack->next = s; \ |
| stack = s; \ |
| } \ |
| else \ |
| stack = stack->next; \ |
| stack->item.pos = (_pos); \ |
| stack->item.str_byte = (_str_byte); \ |
| stack->item.state = (_state); \ |
| stack->item.state_id = (_state_id); \ |
| stack->item.next_c = (_next_c); \ |
| for (i = 0; i < tnfa->num_tags; i++) \ |
| stack->item.tags[i] = (_tags)[i]; \ |
| BT_STACK_MBSTATE_IN; \ |
| } \ |
| while (0) |
| |
| #define BT_STACK_POP() \ |
| do \ |
| { \ |
| int i; \ |
| assert(stack->prev); \ |
| pos = stack->item.pos; \ |
| str_byte = stack->item.str_byte; \ |
| state = stack->item.state; \ |
| next_c = stack->item.next_c; \ |
| for (i = 0; i < tnfa->num_tags; i++) \ |
| tags[i] = stack->item.tags[i]; \ |
| BT_STACK_MBSTATE_OUT; \ |
| stack = stack->prev; \ |
| } \ |
| while (0) |
| |
| #undef MIN |
| #define MIN(a, b) ((a) <= (b) ? (a) : (b)) |
| |
| static reg_errcode_t |
| tre_tnfa_run_backtrack(const tre_tnfa_t *tnfa, const void *string, |
| regoff_t *match_tags, int eflags, regoff_t *match_end_ofs) |
| { |
| /* State variables required by GET_NEXT_WCHAR. */ |
| tre_char_t prev_c = 0, next_c = 0; |
| const char *str_byte = string; |
| regoff_t pos = 0; |
| regoff_t pos_add_next = 1; |
| #ifdef TRE_MBSTATE |
| mbstate_t mbstate; |
| #endif /* TRE_MBSTATE */ |
| int reg_notbol = eflags & REG_NOTBOL; |
| int reg_noteol = eflags & REG_NOTEOL; |
| int reg_newline = tnfa->cflags & REG_NEWLINE; |
| |
| /* These are used to remember the necessary values of the above |
| variables to return to the position where the current search |
| started from. */ |
| int next_c_start; |
| const char *str_byte_start; |
| regoff_t pos_start = -1; |
| #ifdef TRE_MBSTATE |
| mbstate_t mbstate_start; |
| #endif /* TRE_MBSTATE */ |
| |
| /* End offset of best match so far, or -1 if no match found yet. */ |
| regoff_t match_eo = -1; |
| /* Tag arrays. */ |
| int *next_tags; |
| regoff_t *tags = NULL; |
| /* Current TNFA state. */ |
| tre_tnfa_transition_t *state; |
| int *states_seen = NULL; |
| |
| /* Memory allocator to for allocating the backtracking stack. */ |
| tre_mem_t mem = tre_bt_mem_new(); |
| |
| /* The backtracking stack. */ |
| tre_backtrack_t stack; |
| |
| tre_tnfa_transition_t *trans_i; |
| regmatch_t *pmatch = NULL; |
| int ret; |
| |
| #ifdef TRE_MBSTATE |
| memset(&mbstate, '\0', sizeof(mbstate)); |
| #endif /* TRE_MBSTATE */ |
| |
| if (!mem) |
| return REG_ESPACE; |
| stack = tre_bt_mem_alloc(mem, sizeof(*stack)); |
| if (!stack) |
| { |
| ret = REG_ESPACE; |
| goto error_exit; |
| } |
| stack->prev = NULL; |
| stack->next = NULL; |
| |
| if (tnfa->num_tags) |
| { |
| tags = xmalloc(sizeof(*tags) * tnfa->num_tags); |
| if (!tags) |
| { |
| ret = REG_ESPACE; |
| goto error_exit; |
| } |
| } |
| if (tnfa->num_submatches) |
| { |
| pmatch = xmalloc(sizeof(*pmatch) * tnfa->num_submatches); |
| if (!pmatch) |
| { |
| ret = REG_ESPACE; |
| goto error_exit; |
| } |
| } |
| if (tnfa->num_states) |
| { |
| states_seen = xmalloc(sizeof(*states_seen) * tnfa->num_states); |
| if (!states_seen) |
| { |
| ret = REG_ESPACE; |
| goto error_exit; |
| } |
| } |
| |
| retry: |
| { |
| int i; |
| for (i = 0; i < tnfa->num_tags; i++) |
| { |
| tags[i] = -1; |
| if (match_tags) |
| match_tags[i] = -1; |
| } |
| for (i = 0; i < tnfa->num_states; i++) |
| states_seen[i] = 0; |
| } |
| |
| state = NULL; |
| pos = pos_start; |
| GET_NEXT_WCHAR(); |
| pos_start = pos; |
| next_c_start = next_c; |
| str_byte_start = str_byte; |
| #ifdef TRE_MBSTATE |
| mbstate_start = mbstate; |
| #endif /* TRE_MBSTATE */ |
| |
| /* Handle initial states. */ |
| next_tags = NULL; |
| for (trans_i = tnfa->initial; trans_i->state; trans_i++) |
| { |
| if (trans_i->assertions && CHECK_ASSERTIONS(trans_i->assertions)) |
| { |
| continue; |
| } |
| if (state == NULL) |
| { |
| /* Start from this state. */ |
| state = trans_i->state; |
| next_tags = trans_i->tags; |
| } |
| else |
| { |
| /* Backtrack to this state. */ |
| BT_STACK_PUSH(pos, str_byte, 0, trans_i->state, |
| trans_i->state_id, next_c, tags, mbstate); |
| { |
| int *tmp = trans_i->tags; |
| if (tmp) |
| while (*tmp >= 0) |
| stack->item.tags[*tmp++] = pos; |
| } |
| } |
| } |
| |
| if (next_tags) |
| for (; *next_tags >= 0; next_tags++) |
| tags[*next_tags] = pos; |
| |
| |
| if (state == NULL) |
| goto backtrack; |
| |
| while (1) |
| { |
| tre_tnfa_transition_t *next_state; |
| int empty_br_match; |
| |
| if (state == tnfa->final) |
| { |
| if (match_eo < pos |
| || (match_eo == pos |
| && match_tags |
| && tre_tag_order(tnfa->num_tags, tnfa->tag_directions, |
| tags, match_tags))) |
| { |
| int i; |
| /* This match wins the previous match. */ |
| match_eo = pos; |
| if (match_tags) |
| for (i = 0; i < tnfa->num_tags; i++) |
| match_tags[i] = tags[i]; |
| } |
| /* Our TNFAs never have transitions leaving from the final state, |
| so we jump right to backtracking. */ |
| goto backtrack; |
| } |
| |
| /* Go to the next character in the input string. */ |
| empty_br_match = 0; |
| trans_i = state; |
| if (trans_i->state && trans_i->assertions & ASSERT_BACKREF) |
| { |
| /* This is a back reference state. All transitions leaving from |
| this state have the same back reference "assertion". Instead |
| of reading the next character, we match the back reference. */ |
| regoff_t so, eo; |
| int bt = trans_i->u.backref; |
| regoff_t bt_len; |
| int result; |
| |
| /* Get the substring we need to match against. Remember to |
| turn off REG_NOSUB temporarily. */ |
| tre_fill_pmatch(bt + 1, pmatch, tnfa->cflags & ~REG_NOSUB, |
| tnfa, tags, pos); |
| so = pmatch[bt].rm_so; |
| eo = pmatch[bt].rm_eo; |
| bt_len = eo - so; |
| |
| result = strncmp((const char*)string + so, str_byte - 1, |
| (size_t)bt_len); |
| |
| if (result == 0) |
| { |
| /* Back reference matched. Check for infinite loop. */ |
| if (bt_len == 0) |
| empty_br_match = 1; |
| if (empty_br_match && states_seen[trans_i->state_id]) |
| { |
| goto backtrack; |
| } |
| |
| states_seen[trans_i->state_id] = empty_br_match; |
| |
| /* Advance in input string and resync `prev_c', `next_c' |
| and pos. */ |
| str_byte += bt_len - 1; |
| pos += bt_len - 1; |
| GET_NEXT_WCHAR(); |
| } |
| else |
| { |
| goto backtrack; |
| } |
| } |
| else |
| { |
| /* Check for end of string. */ |
| if (next_c == L'\0') |
| goto backtrack; |
| |
| /* Read the next character. */ |
| GET_NEXT_WCHAR(); |
| } |
| |
| next_state = NULL; |
| for (trans_i = state; trans_i->state; trans_i++) |
| { |
| if (trans_i->code_min <= (tre_cint_t)prev_c |
| && trans_i->code_max >= (tre_cint_t)prev_c) |
| { |
| if (trans_i->assertions |
| && (CHECK_ASSERTIONS(trans_i->assertions) |
| || CHECK_CHAR_CLASSES(trans_i, tnfa, eflags))) |
| { |
| continue; |
| } |
| |
| if (next_state == NULL) |
| { |
| /* First matching transition. */ |
| next_state = trans_i->state; |
| next_tags = trans_i->tags; |
| } |
| else |
| { |
| /* Second matching transition. We may need to backtrack here |
| to take this transition instead of the first one, so we |
| push this transition in the backtracking stack so we can |
| jump back here if needed. */ |
| BT_STACK_PUSH(pos, str_byte, 0, trans_i->state, |
| trans_i->state_id, next_c, tags, mbstate); |
| { |
| int *tmp; |
| for (tmp = trans_i->tags; tmp && *tmp >= 0; tmp++) |
| stack->item.tags[*tmp] = pos; |
| } |
| #if 0 /* XXX - it's important not to look at all transitions here to keep |
| the stack small! */ |
| break; |
| #endif |
| } |
| } |
| } |
| |
| if (next_state != NULL) |
| { |
| /* Matching transitions were found. Take the first one. */ |
| state = next_state; |
| |
| /* Update the tag values. */ |
| if (next_tags) |
| while (*next_tags >= 0) |
| tags[*next_tags++] = pos; |
| } |
| else |
| { |
| backtrack: |
| /* A matching transition was not found. Try to backtrack. */ |
| if (stack->prev) |
| { |
| if (stack->item.state->assertions & ASSERT_BACKREF) |
| { |
| states_seen[stack->item.state_id] = 0; |
| } |
| |
| BT_STACK_POP(); |
| } |
| else if (match_eo < 0) |
| { |
| /* Try starting from a later position in the input string. */ |
| /* Check for end of string. */ |
| if (next_c == L'\0') |
| { |
| break; |
| } |
| next_c = next_c_start; |
| #ifdef TRE_MBSTATE |
| mbstate = mbstate_start; |
| #endif /* TRE_MBSTATE */ |
| str_byte = str_byte_start; |
| goto retry; |
| } |
| else |
| { |
| break; |
| } |
| } |
| } |
| |
| ret = match_eo >= 0 ? REG_OK : REG_NOMATCH; |
| *match_end_ofs = match_eo; |
| |
| error_exit: |
| tre_bt_mem_destroy(mem); |
| #ifndef TRE_USE_ALLOCA |
| if (tags) |
| xfree(tags); |
| if (pmatch) |
| xfree(pmatch); |
| if (states_seen) |
| xfree(states_seen); |
| #endif /* !TRE_USE_ALLOCA */ |
| |
| return ret; |
| } |
| |
| /*********************************************************************** |
| from regexec.c |
| ***********************************************************************/ |
| |
| /* Fills the POSIX.2 regmatch_t array according to the TNFA tag and match |
| endpoint values. */ |
| static void |
| tre_fill_pmatch(size_t nmatch, regmatch_t pmatch[], int cflags, |
| const tre_tnfa_t *tnfa, regoff_t *tags, regoff_t match_eo) |
| { |
| tre_submatch_data_t *submatch_data; |
| unsigned int i, j; |
| int *parents; |
| |
| i = 0; |
| if (match_eo >= 0 && !(cflags & REG_NOSUB)) |
| { |
| /* Construct submatch offsets from the tags. */ |
| submatch_data = tnfa->submatch_data; |
| while (i < tnfa->num_submatches && i < nmatch) |
| { |
| if (submatch_data[i].so_tag == tnfa->end_tag) |
| pmatch[i].rm_so = match_eo; |
| else |
| pmatch[i].rm_so = tags[submatch_data[i].so_tag]; |
| |
| if (submatch_data[i].eo_tag == tnfa->end_tag) |
| pmatch[i].rm_eo = match_eo; |
| else |
| pmatch[i].rm_eo = tags[submatch_data[i].eo_tag]; |
| |
| /* If either of the endpoints were not used, this submatch |
| was not part of the match. */ |
| if (pmatch[i].rm_so == -1 || pmatch[i].rm_eo == -1) |
| pmatch[i].rm_so = pmatch[i].rm_eo = -1; |
| |
| i++; |
| } |
| /* Reset all submatches that are not within all of their parent |
| submatches. */ |
| i = 0; |
| while (i < tnfa->num_submatches && i < nmatch) |
| { |
| if (pmatch[i].rm_eo == -1) |
| assert(pmatch[i].rm_so == -1); |
| assert(pmatch[i].rm_so <= pmatch[i].rm_eo); |
| |
| parents = submatch_data[i].parents; |
| if (parents != NULL) |
| for (j = 0; parents[j] >= 0; j++) |
| { |
| if (pmatch[i].rm_so < pmatch[parents[j]].rm_so |
| || pmatch[i].rm_eo > pmatch[parents[j]].rm_eo) |
| pmatch[i].rm_so = pmatch[i].rm_eo = -1; |
| } |
| i++; |
| } |
| } |
| |
| while (i < nmatch) |
| { |
| pmatch[i].rm_so = -1; |
| pmatch[i].rm_eo = -1; |
| i++; |
| } |
| } |
| |
| |
| /* |
| Wrapper functions for POSIX compatible regexp matching. |
| */ |
| |
| int |
| regexec(const regex_t *restrict preg, const char *restrict string, |
| size_t nmatch, regmatch_t pmatch[restrict], int eflags) |
| { |
| tre_tnfa_t *tnfa = (void *)preg->TRE_REGEX_T_FIELD; |
| reg_errcode_t status; |
| regoff_t *tags = NULL, eo; |
| if (tnfa->cflags & REG_NOSUB) nmatch = 0; |
| if (tnfa->num_tags > 0 && nmatch > 0) |
| { |
| tags = xmalloc(sizeof(*tags) * tnfa->num_tags); |
| if (tags == NULL) |
| return REG_ESPACE; |
| } |
| |
| /* Dispatch to the appropriate matcher. */ |
| if (tnfa->have_backrefs) |
| { |
| /* The regex has back references, use the backtracking matcher. */ |
| status = tre_tnfa_run_backtrack(tnfa, string, tags, eflags, &eo); |
| } |
| else |
| { |
| /* Exact matching, no back references, use the parallel matcher. */ |
| status = tre_tnfa_run_parallel(tnfa, string, tags, eflags, &eo); |
| } |
| |
| if (status == REG_OK) |
| /* A match was found, so fill the submatch registers. */ |
| tre_fill_pmatch(nmatch, pmatch, tnfa->cflags, tnfa, tags, eo); |
| if (tags) |
| xfree(tags); |
| return status; |
| } |
