Current Path : /usr/src/usr.bin/grep/regex/ |
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Current File : //usr/src/usr.bin/grep/regex/tre-fastmatch.c |
/* $FreeBSD: release/9.1.0/usr.bin/grep/regex/tre-fastmatch.c 226573 2011-10-20 16:08:11Z gabor $ */ /*- * Copyright (c) 1999 James Howard and Dag-Erling Coïdan Smørgrav * Copyright (C) 2008-2011 Gabor Kovesdan <gabor@FreeBSD.org> * 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 AUTHOR 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 AUTHOR 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 "glue.h" #include <ctype.h> #include <limits.h> #include <regex.h> #include <stdbool.h> #include <stdlib.h> #include <string.h> #ifdef TRE_WCHAR #include <wchar.h> #include <wctype.h> #endif #include "hashtable.h" #include "tre-fastmatch.h" #include "xmalloc.h" static int fastcmp(const fastmatch_t *fg, const void *data, tre_str_type_t type); /* * Clean up if pattern compilation fails. */ #define FAIL_COMP(errcode) \ { \ if (fg->pattern) \ xfree(fg->pattern); \ if (fg->wpattern) \ xfree(fg->wpattern); \ if (fg->qsBc_table) \ hashtable_free(fg->qsBc_table); \ fg = NULL; \ return errcode; \ } /* * Skips n characters in the input string and assigns the start * address to startptr. Note: as per IEEE Std 1003.1-2008 * matching is based on bit pattern not character representations * so we can handle MB strings as byte sequences just like * SB strings. */ #define SKIP_CHARS(n) \ switch (type) \ { \ case STR_WIDE: \ startptr = str_wide + n; \ break; \ default: \ startptr = str_byte + n; \ } /* * Converts the wide string pattern to SB/MB string and stores * it in fg->pattern. Sets fg->len to the byte length of the * converted string. */ #define STORE_MBS_PAT \ { \ size_t siz; \ \ siz = wcstombs(NULL, fg->wpattern, 0); \ if (siz == (size_t)-1) \ return REG_BADPAT; \ fg->len = siz; \ fg->pattern = xmalloc(siz + 1); \ if (fg->pattern == NULL) \ return REG_ESPACE; \ wcstombs(fg->pattern, fg->wpattern, siz); \ fg->pattern[siz] = '\0'; \ } \ #define IS_OUT_OF_BOUNDS \ ((!fg->reversed \ ? ((type == STR_WIDE) ? ((j + fg->wlen) > len) \ : ((j + fg->len) > len)) \ : (j < 0))) /* * Checks whether the new position after shifting in the input string * is out of the bounds and break out from the loop if so. */ #define CHECKBOUNDS \ if (IS_OUT_OF_BOUNDS) \ break; \ /* * Shifts in the input string after a mismatch. The position of the * mismatch is stored in the mismatch variable. */ #define SHIFT \ CHECKBOUNDS; \ \ { \ int r = -1; \ unsigned int bc = 0, gs = 0, ts; \ \ switch (type) \ { \ case STR_WIDE: \ if (!fg->hasdot) \ { \ if (u != 0 && (unsigned)mismatch == fg->wlen - 1 - shift) \ mismatch -= u; \ v = fg->wlen - 1 - mismatch; \ r = hashtable_get(fg->qsBc_table, \ &str_wide[!fg->reversed ? (size_t)j + fg->wlen \ : (size_t)j - 1], &bc); \ gs = fg->bmGs[mismatch]; \ } \ bc = (r == HASH_OK) ? bc : fg->defBc; \ DPRINT(("tre_fast_match: mismatch on character" CHF ", " \ "BC %d, GS %d\n", \ ((const tre_char_t *)startptr)[mismatch + 1], \ bc, gs)); \ break; \ default: \ if (!fg->hasdot) \ { \ if (u != 0 && (unsigned)mismatch == fg->len - 1 - shift) \ mismatch -= u; \ v = fg->len - 1 - mismatch; \ gs = fg->sbmGs[mismatch]; \ } \ bc = fg->qsBc[((const unsigned char *)str_byte) \ [!fg->reversed ? (size_t)j + fg->len \ : (size_t)j - 1]]; \ DPRINT(("tre_fast_match: mismatch on character %c, " \ "BC %d, GS %d\n", \ ((const unsigned char *)startptr)[mismatch + 1], \ bc, gs)); \ } \ if (fg->hasdot) \ shift = bc; \ else \ { \ ts = (u >= v) ? (u - v) : 0; \ shift = MAX(ts, bc); \ shift = MAX(shift, gs); \ if (shift == gs) \ u = MIN((type == STR_WIDE ? fg->wlen : fg->len) - shift, v); \ else \ { \ if (ts < bc) \ shift = MAX(shift, u + 1); \ u = 0; \ } \ } \ DPRINT(("tre_fast_match: shifting %u characters\n", shift)); \ j = !fg->reversed ? j + shift : j - shift; \ } /* * Normal Quick Search would require a shift based on the position the * next character after the comparison is within the pattern. With * wildcards, the position of the last dot effects the maximum shift * distance. * The closer to the end the wild card is the slower the search. * * Examples: * Pattern Max shift * ------- --------- * this 5 * .his 4 * t.is 3 * th.s 2 * thi. 1 */ /* * Fills in the bad character shift array for SB/MB strings. */ #define FILL_QSBC \ if (fg->reversed) \ { \ _FILL_QSBC_REVERSED \ } \ else \ { \ _FILL_QSBC \ } #define _FILL_QSBC \ for (unsigned int i = 0; i <= UCHAR_MAX; i++) \ fg->qsBc[i] = fg->len - hasdot; \ for (unsigned int i = hasdot + 1; i < fg->len; i++) \ { \ fg->qsBc[(unsigned char)fg->pattern[i]] = fg->len - i; \ DPRINT(("BC shift for char %c is %zu\n", fg->pattern[i], \ fg->len - i)); \ if (fg->icase) \ { \ char c = islower((unsigned char)fg->pattern[i]) ? \ toupper((unsigned char)fg->pattern[i]) : \ tolower((unsigned char)fg->pattern[i]); \ fg->qsBc[(unsigned char)c] = fg->len - i; \ DPRINT(("BC shift for char %c is %zu\n", c, fg->len - i)); \ } \ } #define _FILL_QSBC_REVERSED \ for (unsigned int i = 0; i <= UCHAR_MAX; i++) \ fg->qsBc[i] = firstdot + 1; \ for (int i = firstdot - 1; i >= 0; i--) \ { \ fg->qsBc[(unsigned char)fg->pattern[i]] = i + 1; \ DPRINT(("Reverse BC shift for char %c is %d\n", fg->pattern[i], \ i + 1)); \ if (fg->icase) \ { \ char c = islower((unsigned char)fg->pattern[i]) ? \ toupper((unsigned char)fg->pattern[i]) : \ tolower((unsigned char)fg->pattern[i]); \ fg->qsBc[(unsigned char)c] = i + 1; \ DPRINT(("Reverse BC shift for char %c is %d\n", c, i + 1)); \ } \ } /* * Fills in the bad character shifts into a hastable for wide strings. * With wide characters it is not possible any more to use a normal * array because there are too many characters and we could not * provide enough memory. Fortunately, we only have to store distinct * values for so many characters as the number of distinct characters * in the pattern, so we can store them in a hashtable and store a * default shift value for the rest. */ #define FILL_QSBC_WIDE \ if (fg->reversed) \ { \ _FILL_QSBC_WIDE_REVERSED \ } \ else \ { \ _FILL_QSBC_WIDE \ } #define _FILL_QSBC_WIDE \ /* Adjust the shift based on location of the last dot ('.'). */ \ fg->defBc = fg->wlen - whasdot; \ \ /* Preprocess pattern. */ \ fg->qsBc_table = hashtable_init(fg->wlen * (fg->icase ? 8 : 4), \ sizeof(tre_char_t), sizeof(int)); \ if (!fg->qsBc_table) \ FAIL_COMP(REG_ESPACE); \ for (unsigned int i = whasdot + 1; i < fg->wlen; i++) \ { \ int k = fg->wlen - i; \ int r; \ \ r = hashtable_put(fg->qsBc_table, &fg->wpattern[i], &k); \ if ((r == HASH_FAIL) || (r == HASH_FULL)) \ FAIL_COMP(REG_ESPACE); \ DPRINT(("BC shift for wide char " CHF " is %d\n", fg->wpattern[i],\ k)); \ if (fg->icase) \ { \ tre_char_t wc = iswlower(fg->wpattern[i]) ? \ towupper(fg->wpattern[i]) : towlower(fg->wpattern[i]); \ r = hashtable_put(fg->qsBc_table, &wc, &k); \ if ((r == HASH_FAIL) || (r == HASH_FULL)) \ FAIL_COMP(REG_ESPACE); \ DPRINT(("BC shift for wide char " CHF " is %d\n", wc, k)); \ } \ } #define _FILL_QSBC_WIDE_REVERSED \ /* Adjust the shift based on location of the last dot ('.'). */ \ fg->defBc = (size_t)wfirstdot; \ \ /* Preprocess pattern. */ \ fg->qsBc_table = hashtable_init(fg->wlen * (fg->icase ? 8 : 4), \ sizeof(tre_char_t), sizeof(int)); \ if (!fg->qsBc_table) \ FAIL_COMP(REG_ESPACE); \ for (int i = wfirstdot - 1; i >= 0; i--) \ { \ int k = i + 1; \ int r; \ \ r = hashtable_put(fg->qsBc_table, &fg->wpattern[i], &k); \ if ((r == HASH_FAIL) || (r == HASH_FULL)) \ FAIL_COMP(REG_ESPACE); \ DPRINT(("Reverse BC shift for wide char " CHF " is %d\n", \ fg->wpattern[i], k)); \ if (fg->icase) \ { \ tre_char_t wc = iswlower(fg->wpattern[i]) ? \ towupper(fg->wpattern[i]) : towlower(fg->wpattern[i]); \ r = hashtable_put(fg->qsBc_table, &wc, &k); \ if ((r == HASH_FAIL) || (r == HASH_FULL)) \ FAIL_COMP(REG_ESPACE); \ DPRINT(("Reverse BC shift for wide char " CHF " is %d\n", wc, \ k)); \ } \ } #ifdef _GREP_DEBUG #define DPRINT_BMGS(len, fmt_str, sh) \ for (unsigned int i = 0; i < len; i++) \ DPRINT((fmt_str, i, sh[i])); #else #define DPRINT_BMGS(len, fmt_str, sh) \ do { } while(/*CONSTCOND*/0) #endif /* * Fills in the good suffix table for SB/MB strings. */ #define FILL_BMGS \ if (!fg->hasdot) \ { \ fg->sbmGs = xmalloc(fg->len * sizeof(int)); \ if (!fg->sbmGs) \ return REG_ESPACE; \ if (fg->len == 1) \ fg->sbmGs[0] = 1; \ else \ _FILL_BMGS(fg->sbmGs, fg->pattern, fg->len, false); \ DPRINT_BMGS(fg->len, "GS shift for pos %d is %d\n", fg->sbmGs); \ } /* * Fills in the good suffix table for wide strings. */ #define FILL_BMGS_WIDE \ if (!fg->hasdot) \ { \ fg->bmGs = xmalloc(fg->wlen * sizeof(int)); \ if (!fg->bmGs) \ return REG_ESPACE; \ if (fg->wlen == 1) \ fg->bmGs[0] = 1; \ else \ _FILL_BMGS(fg->bmGs, fg->wpattern, fg->wlen, true); \ DPRINT_BMGS(fg->wlen, "GS shift (wide) for pos %d is %d\n", \ fg->bmGs); \ } #define _FILL_BMGS(arr, pat, plen, wide) \ { \ char *p; \ tre_char_t *wp; \ \ if (wide) \ { \ if (fg->icase) \ { \ wp = xmalloc(plen * sizeof(tre_char_t)); \ if (wp == NULL) \ return REG_ESPACE; \ for (unsigned int i = 0; i < plen; i++) \ wp[i] = towlower(pat[i]); \ _CALC_BMGS(arr, wp, plen); \ xfree(wp); \ } \ else \ _CALC_BMGS(arr, pat, plen); \ } \ else \ { \ if (fg->icase) \ { \ p = xmalloc(plen); \ if (p == NULL) \ return REG_ESPACE; \ for (unsigned int i = 0; i < plen; i++) \ p[i] = tolower(pat[i]); \ _CALC_BMGS(arr, p, plen); \ xfree(p); \ } \ else \ _CALC_BMGS(arr, pat, plen); \ } \ } #define _CALC_BMGS(arr, pat, plen) \ { \ int f = 0, g; \ \ int *suff = xmalloc(plen * sizeof(int)); \ if (suff == NULL) \ return REG_ESPACE; \ \ suff[plen - 1] = plen; \ g = plen - 1; \ for (int i = plen - 2; i >= 0; i--) \ { \ if (i > g && suff[i + plen - 1 - f] < i - g) \ suff[i] = suff[i + plen - 1 - f]; \ else \ { \ if (i < g) \ g = i; \ f = i; \ while (g >= 0 && pat[g] == pat[g + plen - 1 - f]) \ g--; \ suff[i] = f - g; \ } \ } \ \ for (unsigned int i = 0; i < plen; i++) \ arr[i] = plen; \ g = 0; \ for (int i = plen - 1; i >= 0; i--) \ if (suff[i] == i + 1) \ for(; (unsigned long)g < plen - 1 - i; g++) \ if (arr[g] == plen) \ arr[g] = plen - 1 - i; \ for (unsigned int i = 0; i <= plen - 2; i++) \ arr[plen - 1 - suff[i]] = plen - 1 - i; \ \ xfree(suff); \ } /* * Copies the pattern pat having lenght n to p and stores * the size in l. */ #define SAVE_PATTERN(src, srclen, dst, dstlen) \ dstlen = srclen; \ dst = xmalloc((dstlen + 1) * sizeof(tre_char_t)); \ if (dst == NULL) \ return REG_ESPACE; \ if (dstlen > 0) \ memcpy(dst, src, dstlen * sizeof(tre_char_t)); \ dst[dstlen] = TRE_CHAR('\0'); /* * Initializes pattern compiling. */ #define INIT_COMP \ /* Initialize. */ \ memset(fg, 0, sizeof(*fg)); \ fg->icase = (cflags & REG_ICASE); \ fg->word = (cflags & REG_WORD); \ fg->newline = (cflags & REG_NEWLINE); \ fg->nosub = (cflags & REG_NOSUB); \ \ /* Cannot handle REG_ICASE with MB string */ \ if (fg->icase && (TRE_MB_CUR_MAX > 1)) \ { \ DPRINT(("Cannot use fast matcher for MBS with REG_ICASE\n")); \ return REG_BADPAT; \ } /* * Checks whether we have a 0-length pattern that will match * anything. If literal is set to false, the EOL anchor is also * taken into account. */ #define CHECK_MATCHALL(literal) \ if (!literal && n == 1 && pat[0] == TRE_CHAR('$')) \ { \ n--; \ fg->eol = true; \ } \ \ if (n == 0) \ { \ fg->matchall = true; \ fg->pattern = xmalloc(sizeof(char)); \ if (!fg->pattern) \ FAIL_COMP(REG_ESPACE); \ fg->pattern[0] = '\0'; \ fg->wpattern = xmalloc(sizeof(tre_char_t)); \ if (!fg->wpattern) \ FAIL_COMP(REG_ESPACE); \ fg->wpattern[0] = TRE_CHAR('\0'); \ DPRINT(("Matching every input\n")); \ return REG_OK; \ } /* * Returns: REG_OK on success, error code otherwise */ int tre_compile_literal(fastmatch_t *fg, const tre_char_t *pat, size_t n, int cflags) { size_t hasdot = 0, whasdot = 0; ssize_t firstdot = -1, wfirstdot = -1; INIT_COMP; CHECK_MATCHALL(true); /* Cannot handle word boundaries with MB string */ if (fg->word && (TRE_MB_CUR_MAX > 1)) return REG_BADPAT; #ifdef TRE_WCHAR SAVE_PATTERN(pat, n, fg->wpattern, fg->wlen); STORE_MBS_PAT; #else SAVE_PATTERN(pat, n, fg->pattern, fg->len); #endif DPRINT(("tre_compile_literal: pattern: %s, len %zu, icase: %c, word: %c, " "newline %c\n", fg->pattern, fg->len, fg->icase ? 'y' : 'n', fg->word ? 'y' : 'n', fg->newline ? 'y' : 'n')); FILL_QSBC; FILL_BMGS; #ifdef TRE_WCHAR FILL_QSBC_WIDE; FILL_BMGS_WIDE; #endif return REG_OK; } /* * Returns: REG_OK on success, error code otherwise */ int tre_compile_fast(fastmatch_t *fg, const tre_char_t *pat, size_t n, int cflags) { tre_char_t *tmp; size_t pos = 0, hasdot = 0, whasdot = 0; ssize_t firstdot = -1, wfirstdot = -1; bool escaped = false; bool *_escmap = NULL; INIT_COMP; /* Remove beginning-of-line character ('^'). */ if (pat[0] == TRE_CHAR('^')) { fg->bol = true; n--; pat++; } CHECK_MATCHALL(false); /* Handle word-boundary matching when GNU extensions are enabled */ if ((cflags & REG_GNU) && (n >= 14) && (memcmp(pat, TRE_CHAR("[[:<:]]"), 7 * sizeof(tre_char_t)) == 0) && (memcmp(pat + n - 7, TRE_CHAR("[[:>:]]"), 7 * sizeof(tre_char_t)) == 0)) { n -= 14; pat += 7; fg->word = true; } /* Cannot handle word boundaries with MB string */ if (fg->word && (TRE_MB_CUR_MAX > 1)) return REG_BADPAT; tmp = xmalloc((n + 1) * sizeof(tre_char_t)); if (tmp == NULL) return REG_ESPACE; /* Copies the char into the stored pattern and skips to the next char. */ #define STORE_CHAR \ do \ { \ tmp[pos++] = pat[i]; \ escaped = false; \ continue; \ } while (0) /* Traverse the input pattern for processing */ for (unsigned int i = 0; i < n; i++) { switch (pat[i]) { case TRE_CHAR('\\'): if (escaped) STORE_CHAR; else if (i == n - 1) goto badpat; else escaped = true; continue; case TRE_CHAR('['): if (escaped) STORE_CHAR; else goto badpat; continue; case TRE_CHAR('*'): if (escaped || (!(cflags & REG_EXTENDED) && (i == 0))) STORE_CHAR; else goto badpat; continue; case TRE_CHAR('+'): case TRE_CHAR('?'): if ((cflags & REG_EXTENDED) && (i == 0)) continue; else if ((cflags & REG_EXTENDED) ^ !escaped) STORE_CHAR; else goto badpat; continue; case TRE_CHAR('.'): if (escaped) { if (!_escmap) _escmap = xmalloc(n * sizeof(bool)); if (!_escmap) { xfree(tmp); return REG_ESPACE; } _escmap[i] = true; STORE_CHAR; } else { whasdot = i; if (wfirstdot == -1) wfirstdot = i; STORE_CHAR; } continue; case TRE_CHAR('^'): STORE_CHAR; continue; case TRE_CHAR('$'): if (!escaped && (i == n - 1)) fg->eol = true; else STORE_CHAR; continue; case TRE_CHAR('('): if ((cflags & REG_EXTENDED) ^ escaped) goto badpat; else STORE_CHAR; continue; case TRE_CHAR('{'): if (!(cflags & REG_EXTENDED) ^ escaped) STORE_CHAR; else if (!(cflags & REG_EXTENDED) && (i == 0)) STORE_CHAR; else if ((cflags & REG_EXTENDED) && (i == 0)) continue; else goto badpat; continue; case TRE_CHAR('|'): if ((cflags & REG_EXTENDED) ^ escaped) goto badpat; else STORE_CHAR; continue; default: if (escaped) goto badpat; else STORE_CHAR; continue; } continue; badpat: xfree(tmp); DPRINT(("tre_compile_fast: compilation of pattern failed, falling" "back to NFA\n")); return REG_BADPAT; } fg->hasdot = wfirstdot > -1; /* * The pattern has been processed and copied to tmp as a literal string * with escapes, anchors (^$) and the word boundary match character * classes stripped out. */ #ifdef TRE_WCHAR SAVE_PATTERN(tmp, pos, fg->wpattern, fg->wlen); fg->wescmap = _escmap; STORE_MBS_PAT; /* * The position of dots and escaped dots is different in the MB string * than in to the wide string so traverse the converted string, as well, * to store these positions. */ if (fg->hasdot || (fg->wescmap != NULL)) { if (fg->wescmap != NULL) { fg->escmap = xmalloc(fg->len * sizeof(bool)); if (!fg->escmap) { tre_free_fast(fg); return REG_ESPACE; } } escaped = false; for (unsigned int i = 0; i < fg->len; i++) if (fg->pattern[i] == '\\') escaped = !escaped; else if (fg->pattern[i] == '.' && escaped) { fg->escmap[i] = true; escaped = false; } else if (fg->pattern[i] == '.' && !escaped) { hasdot = i; if (firstdot == -1) firstdot = i; } else escaped = false; } #else SAVE_PATTERN(tmp, pos, fg->pattern, fg->len); fg->escmap = _escmap; #endif xfree(tmp); DPRINT(("tre_compile_fast: pattern: %s, len %zu, bol %c, eol %c, " "icase: %c, word: %c, newline %c\n", fg->pattern, fg->len, fg->bol ? 'y' : 'n', fg->eol ? 'y' : 'n', fg->icase ? 'y' : 'n', fg->word ? 'y' : 'n', fg->newline ? 'y' : 'n')); /* Check whether reverse QS algorithm is more efficient */ if ((wfirstdot > -1) && (fg->wlen - whasdot + 1 < (size_t)wfirstdot) && fg->nosub) { fg->reversed = true; DPRINT(("tre_compile_fast: using reverse QS algorithm\n")); } FILL_QSBC; FILL_BMGS; #ifdef TRE_WCHAR FILL_QSBC_WIDE; FILL_BMGS_WIDE; #endif return REG_OK; } #define _SHIFT_ONE \ { \ shift = 1; \ j = !fg->reversed ? j + shift : j - shift; \ continue; \ } #define _BBOUND_COND \ ((type == STR_WIDE) ? \ ((j == 0) || !(tre_isalnum(str_wide[j - 1]) || \ (str_wide[j - 1] == TRE_CHAR('_')))) : \ ((j == 0) || !(tre_isalnum(str_byte[j - 1]) || \ (str_byte[j - 1] == '_')))) #define _EBOUND_COND \ ((type == STR_WIDE) ? \ ((j + fg->wlen == len) || !(tre_isalnum(str_wide[j + fg->wlen]) || \ (str_wide[j + fg->wlen] == TRE_CHAR('_')))) : \ ((j + fg->len == len) || !(tre_isalnum(str_byte[j + fg->len]) || \ (str_byte[j + fg->len] == '_')))) /* * Condition to check whether the match on position j is on a * word boundary. */ #define IS_ON_WORD_BOUNDARY \ (_BBOUND_COND && _EBOUND_COND) /* * Checks word boundary and shifts one if match is not on a * boundary. */ #define CHECK_WORD_BOUNDARY \ if (!IS_ON_WORD_BOUNDARY) \ _SHIFT_ONE; #define _BOL_COND \ ((j == 0) || ((type == STR_WIDE) ? (str_wide[j - 1] == TRE_CHAR('\n'))\ : (str_byte[j - 1] == '\n'))) /* * Checks BOL anchor and shifts one if match is not on a * boundary. */ #define CHECK_BOL_ANCHOR \ if (!_BOL_COND) \ _SHIFT_ONE; #define _EOL_COND \ ((type == STR_WIDE) \ ? ((j + fg->wlen == len) || \ (str_wide[j + fg->wlen] == TRE_CHAR('\n'))) \ : ((j + fg->len == len) || (str_byte[j + fg->wlen] == '\n'))) /* * Checks EOL anchor and shifts one if match is not on a * boundary. */ #define CHECK_EOL_ANCHOR \ if (!_EOL_COND) \ _SHIFT_ONE; /* * Executes matching of the precompiled pattern on the input string. * Returns REG_OK or REG_NOMATCH depending on if we find a match or not. */ int tre_match_fast(const fastmatch_t *fg, const void *data, size_t len, tre_str_type_t type, int nmatch, regmatch_t pmatch[], int eflags) { unsigned int shift, u = 0, v = 0; ssize_t j = 0; int ret = REG_NOMATCH; int mismatch; const char *str_byte = data; const void *startptr = NULL; const tre_char_t *str_wide = data; /* Calculate length if unspecified. */ if (len == (size_t)-1) switch (type) { case STR_WIDE: len = tre_strlen(str_wide); break; default: len = strlen(str_byte); break; } /* Shortcut for empty pattern */ if (fg->matchall) { if (!fg->nosub && nmatch >= 1) { pmatch[0].rm_so = 0; pmatch[0].rm_eo = len; } if (fg->bol && fg->eol) return (len == 0) ? REG_OK : REG_NOMATCH; else return REG_OK; } /* No point in going farther if we do not have enough data. */ switch (type) { case STR_WIDE: if (len < fg->wlen) return ret; shift = fg->wlen; break; default: if (len < fg->len) return ret; shift = fg->len; } /* * REG_NOTBOL means not anchoring ^ to the beginning of the line, so we * can shift one because there can't be a match at the beginning. */ if (fg->bol && (eflags & REG_NOTBOL)) j = 1; /* * Like above, we cannot have a match at the very end when anchoring to * the end and REG_NOTEOL is specified. */ if (fg->eol && (eflags & REG_NOTEOL)) len--; if (fg->reversed) j = len - (type == STR_WIDE ? fg->wlen : fg->len); /* Only try once at the beginning or ending of the line. */ if ((fg->bol || fg->eol) && !fg->newline && !(eflags & REG_NOTBOL) && !(eflags & REG_NOTEOL)) { /* Simple text comparison. */ if (!((fg->bol && fg->eol) && (type == STR_WIDE ? (len != fg->wlen) : (len != fg->len)))) { /* Determine where in data to start search at. */ j = fg->eol ? len - (type == STR_WIDE ? fg->wlen : fg->len) : 0; SKIP_CHARS(j); mismatch = fastcmp(fg, startptr, type); if (mismatch == REG_OK) { if (fg->word && !IS_ON_WORD_BOUNDARY) return ret; if (!fg->nosub && nmatch >= 1) { pmatch[0].rm_so = j; pmatch[0].rm_eo = j + (type == STR_WIDE ? fg->wlen : fg->len); } return REG_OK; } } } else { /* Quick Search / Turbo Boyer-Moore algorithm. */ do { SKIP_CHARS(j); mismatch = fastcmp(fg, startptr, type); if (mismatch == REG_OK) { if (fg->word) CHECK_WORD_BOUNDARY; if (fg->bol) CHECK_BOL_ANCHOR; if (fg->eol) CHECK_EOL_ANCHOR; if (!fg->nosub && nmatch >= 1) { pmatch[0].rm_so = j; pmatch[0].rm_eo = j + ((type == STR_WIDE) ? fg->wlen : fg->len); } return REG_OK; } else if (mismatch > 0) return mismatch; mismatch = -mismatch - 1; SHIFT; } while (!IS_OUT_OF_BOUNDS); } return ret; } /* * Frees the resources that were allocated when the pattern was compiled. */ void tre_free_fast(fastmatch_t *fg) { DPRINT(("tre_fast_free: freeing structures for pattern %s\n", fg->pattern)); #ifdef TRE_WCHAR hashtable_free(fg->qsBc_table); if (!fg->hasdot) xfree(fg->bmGs); if (fg->wescmap) xfree(fg->wescmap); xfree(fg->wpattern); #endif if (!fg->hasdot) xfree(fg->sbmGs); if (fg->escmap) xfree(fg->escmap); xfree(fg->pattern); } /* * Returns: -(i + 1) on failure (position that it failed with minus sign) * error code on error * REG_OK on success */ static inline int fastcmp(const fastmatch_t *fg, const void *data, tre_str_type_t type) { const char *str_byte = data; const char *pat_byte = fg->pattern; const tre_char_t *str_wide = data; const tre_char_t *pat_wide = fg->wpattern; const bool *escmap = (type == STR_WIDE) ? fg->wescmap : fg->escmap; size_t len = (type == STR_WIDE) ? fg->wlen : fg->len; int ret = REG_OK; /* Compare the pattern and the input char-by-char from the last position. */ for (int i = len - 1; i >= 0; i--) { switch (type) { case STR_WIDE: /* Check dot */ if (fg->hasdot && pat_wide[i] == TRE_CHAR('.') && (!escmap || !escmap[i]) && (!fg->newline || (str_wide[i] != TRE_CHAR('\n')))) continue; /* Compare */ if (fg->icase ? (towlower(pat_wide[i]) == towlower(str_wide[i])) : (pat_wide[i] == str_wide[i])) continue; break; default: /* Check dot */ if (fg->hasdot && pat_byte[i] == '.' && (!escmap || !escmap[i]) && (!fg->newline || (str_byte[i] != '\n'))) continue; /* Compare */ if (fg->icase ? (tolower(pat_byte[i]) == tolower(str_byte[i])) : (pat_byte[i] == str_byte[i])) continue; } DPRINT(("fastcmp: mismatch at position %d\n", i)); ret = -(i + 1); break; } return ret; }