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Diffstat (limited to 'srclib/pcre/study.c')
| -rw-r--r-- | srclib/pcre/study.c | 397 |
1 files changed, 0 insertions, 397 deletions
diff --git a/srclib/pcre/study.c b/srclib/pcre/study.c deleted file mode 100644 index 676db94665..0000000000 --- a/srclib/pcre/study.c +++ /dev/null @@ -1,397 +0,0 @@ -/************************************************* -* Perl-Compatible Regular Expressions * -*************************************************/ - -/* -This is a library of functions to support regular expressions whose syntax -and semantics are as close as possible to those of the Perl 5 language. See -the file Tech.Notes for some information on the internals. - -Written by: Philip Hazel <ph10@cam.ac.uk> - - Copyright (c) 1997-2000 University of Cambridge - ------------------------------------------------------------------------------ -Permission is granted to anyone to use this software for any purpose on any -computer system, and to redistribute it freely, subject to the following -restrictions: - -1. This software 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. - -2. The origin of this software must not be misrepresented, either by - explicit claim or by omission. - -3. Altered versions must be plainly marked as such, and must not be - misrepresented as being the original software. - -4. If PCRE is embedded in any software that is released under the GNU - General Purpose Licence (GPL), then the terms of that licence shall - supersede any condition above with which it is incompatible. ------------------------------------------------------------------------------ -*/ - - -/* Include the internals header, which itself includes Standard C headers plus -the external pcre header. */ - -#include "internal.h" - - - -/************************************************* -* Set a bit and maybe its alternate case * -*************************************************/ - -/* Given a character, set its bit in the table, and also the bit for the other -version of a letter if we are caseless. - -Arguments: - start_bits points to the bit map - c is the character - caseless the caseless flag - cd the block with char table pointers - -Returns: nothing -*/ - -static void -set_bit(uschar *start_bits, int c, BOOL caseless, compile_data *cd) -{ -start_bits[c/8] |= (1 << (c&7)); -if (caseless && (cd->ctypes[c] & ctype_letter) != 0) - start_bits[cd->fcc[c]/8] |= (1 << (cd->fcc[c]&7)); -} - - - -/************************************************* -* Create bitmap of starting chars * -*************************************************/ - -/* This function scans a compiled unanchored expression and attempts to build a -bitmap of the set of initial characters. If it can't, it returns FALSE. As time -goes by, we may be able to get more clever at doing this. - -Arguments: - code points to an expression - start_bits points to a 32-byte table, initialized to 0 - caseless the current state of the caseless flag - cd the block with char table pointers - -Returns: TRUE if table built, FALSE otherwise -*/ - -static BOOL -set_start_bits(const uschar *code, uschar *start_bits, BOOL caseless, - compile_data *cd) -{ -register int c; - -/* This next statement and the later reference to dummy are here in order to -trick the optimizer of the IBM C compiler for OS/2 into generating correct -code. Apparently IBM isn't going to fix the problem, and we would rather not -disable optimization (in this module it actually makes a big difference, and -the pcre module can use all the optimization it can get). */ - -volatile int dummy; - -do - { - const uschar *tcode = code + 3; - BOOL try_next = TRUE; - - while (try_next) - { - try_next = FALSE; - - /* If a branch starts with a bracket or a positive lookahead assertion, - recurse to set bits from within them. That's all for this branch. */ - - if ((int)*tcode >= OP_BRA || *tcode == OP_ASSERT) - { - if (!set_start_bits(tcode, start_bits, caseless, cd)) - return FALSE; - } - - else switch(*tcode) - { - default: - return FALSE; - - /* Skip over lookbehind and negative lookahead assertions */ - - case OP_ASSERT_NOT: - case OP_ASSERTBACK: - case OP_ASSERTBACK_NOT: - try_next = TRUE; - do tcode += (tcode[1] << 8) + tcode[2]; while (*tcode == OP_ALT); - tcode += 3; - break; - - /* Skip over an option setting, changing the caseless flag */ - - case OP_OPT: - caseless = (tcode[1] & PCRE_CASELESS) != 0; - tcode += 2; - try_next = TRUE; - break; - - /* BRAZERO does the bracket, but carries on. */ - - case OP_BRAZERO: - case OP_BRAMINZERO: - if (!set_start_bits(++tcode, start_bits, caseless, cd)) - return FALSE; - dummy = 1; - do tcode += (tcode[1] << 8) + tcode[2]; while (*tcode == OP_ALT); - tcode += 3; - try_next = TRUE; - break; - - /* Single-char * or ? sets the bit and tries the next item */ - - case OP_STAR: - case OP_MINSTAR: - case OP_QUERY: - case OP_MINQUERY: - set_bit(start_bits, tcode[1], caseless, cd); - tcode += 2; - try_next = TRUE; - break; - - /* Single-char upto sets the bit and tries the next */ - - case OP_UPTO: - case OP_MINUPTO: - set_bit(start_bits, tcode[3], caseless, cd); - tcode += 4; - try_next = TRUE; - break; - - /* At least one single char sets the bit and stops */ - - case OP_EXACT: /* Fall through */ - tcode++; - - case OP_CHARS: /* Fall through */ - tcode++; - - case OP_PLUS: - case OP_MINPLUS: - set_bit(start_bits, tcode[1], caseless, cd); - break; - - /* Single character type sets the bits and stops */ - - case OP_NOT_DIGIT: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_digit]; - break; - - case OP_DIGIT: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_digit]; - break; - - case OP_NOT_WHITESPACE: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_space]; - break; - - case OP_WHITESPACE: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_space]; - break; - - case OP_NOT_WORDCHAR: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_word]; - break; - - case OP_WORDCHAR: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_word]; - break; - - /* One or more character type fudges the pointer and restarts, knowing - it will hit a single character type and stop there. */ - - case OP_TYPEPLUS: - case OP_TYPEMINPLUS: - tcode++; - try_next = TRUE; - break; - - case OP_TYPEEXACT: - tcode += 3; - try_next = TRUE; - break; - - /* Zero or more repeats of character types set the bits and then - try again. */ - - case OP_TYPEUPTO: - case OP_TYPEMINUPTO: - tcode += 2; /* Fall through */ - - case OP_TYPESTAR: - case OP_TYPEMINSTAR: - case OP_TYPEQUERY: - case OP_TYPEMINQUERY: - switch(tcode[1]) - { - case OP_NOT_DIGIT: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_digit]; - break; - - case OP_DIGIT: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_digit]; - break; - - case OP_NOT_WHITESPACE: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_space]; - break; - - case OP_WHITESPACE: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_space]; - break; - - case OP_NOT_WORDCHAR: - for (c = 0; c < 32; c++) - start_bits[c] |= ~cd->cbits[c+cbit_word]; - break; - - case OP_WORDCHAR: - for (c = 0; c < 32; c++) - start_bits[c] |= cd->cbits[c+cbit_word]; - break; - } - - tcode += 2; - try_next = TRUE; - break; - - /* Character class: set the bits and either carry on or not, - according to the repeat count. */ - - case OP_CLASS: - { - tcode++; - for (c = 0; c < 32; c++) start_bits[c] |= tcode[c]; - tcode += 32; - switch (*tcode) - { - case OP_CRSTAR: - case OP_CRMINSTAR: - case OP_CRQUERY: - case OP_CRMINQUERY: - tcode++; - try_next = TRUE; - break; - - case OP_CRRANGE: - case OP_CRMINRANGE: - if (((tcode[1] << 8) + tcode[2]) == 0) - { - tcode += 5; - try_next = TRUE; - } - break; - } - } - break; /* End of class handling */ - - } /* End of switch */ - } /* End of try_next loop */ - - code += (code[1] << 8) + code[2]; /* Advance to next branch */ - } -while (*code == OP_ALT); -return TRUE; -} - - - -/************************************************* -* Study a compiled expression * -*************************************************/ - -/* This function is handed a compiled expression that it must study to produce -information that will speed up the matching. It returns a pcre_extra block -which then gets handed back to pcre_exec(). - -Arguments: - re points to the compiled expression - options contains option bits - errorptr points to where to place error messages; - set NULL unless error - -Returns: pointer to a pcre_extra block, - NULL on error or if no optimization possible -*/ - -pcre_extra * -pcre_study(const pcre *external_re, int options, const char **errorptr) -{ -uschar start_bits[32]; -real_pcre_extra *extra; -const real_pcre *re = (const real_pcre *)external_re; -compile_data compile_block; - -*errorptr = NULL; - -if (re == NULL || re->magic_number != MAGIC_NUMBER) - { - *errorptr = "argument is not a compiled regular expression"; - return NULL; - } - -if ((options & ~PUBLIC_STUDY_OPTIONS) != 0) - { - *errorptr = "unknown or incorrect option bit(s) set"; - return NULL; - } - -/* For an anchored pattern, or an unchored pattern that has a first char, or a -multiline pattern that matches only at "line starts", no further processing at -present. */ - -if ((re->options & (PCRE_ANCHORED|PCRE_FIRSTSET|PCRE_STARTLINE)) != 0) - return NULL; - -/* Set the character tables in the block which is passed around */ - -compile_block.lcc = re->tables + lcc_offset; -compile_block.fcc = re->tables + fcc_offset; -compile_block.cbits = re->tables + cbits_offset; -compile_block.ctypes = re->tables + ctypes_offset; - -/* See if we can find a fixed set of initial characters for the pattern. */ - -memset(start_bits, 0, 32 * sizeof(uschar)); -if (!set_start_bits(re->code, start_bits, (re->options & PCRE_CASELESS) != 0, - &compile_block)) return NULL; - -/* Get an "extra" block and put the information therein. */ - -extra = (real_pcre_extra *)(pcre_malloc)(sizeof(real_pcre_extra)); - -if (extra == NULL) - { - *errorptr = "failed to get memory"; - return NULL; - } - -extra->options = PCRE_STUDY_MAPPED; -memcpy(extra->start_bits, start_bits, sizeof(start_bits)); - -return (pcre_extra *)extra; -} - -/* End of study.c */ |