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author | Vincent Peyruqueou | 2023-03-27 11:46:59 +0200 |
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committer | Vincent Peyruqueou | 2023-03-27 11:46:59 +0200 |
commit | 0916b5f9072f7bd1b7b045ceb07758f9dc097ac2 (patch) | |
tree | 2904afe1d5d4d770695f78db5ccd722735a8e67b /pcre/pcre_study.c | |
parent | 5443d6828eaf5cbc7dc4613d9d75b4c192d17730 (diff) | |
download | ivy-c-master.zip ivy-c-master.tar.gz ivy-c-master.tar.bz2 ivy-c-master.tar.xz |
Diffstat (limited to 'pcre/pcre_study.c')
-rw-r--r-- | pcre/pcre_study.c | 1686 |
1 files changed, 1686 insertions, 0 deletions
diff --git a/pcre/pcre_study.c b/pcre/pcre_study.c new file mode 100644 index 0000000..d9d4960 --- /dev/null +++ b/pcre/pcre_study.c @@ -0,0 +1,1686 @@ +/************************************************* +* Perl-Compatible Regular Expressions * +*************************************************/ + +/* PCRE 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. + + Written by Philip Hazel + Copyright (c) 1997-2012 University of Cambridge + +----------------------------------------------------------------------------- +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + * 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. + + * Neither the name of the University of Cambridge nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS 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 OWNER 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. +----------------------------------------------------------------------------- +*/ + + +/* This module contains the external function pcre_study(), along with local +supporting functions. */ + + +#ifdef HAVE_CONFIG_H +#include "config.h" +#endif + +#include "pcre_internal.h" + +#define SET_BIT(c) start_bits[c/8] |= (1 << (c&7)) + +/* Returns from set_start_bits() */ + +enum { SSB_FAIL, SSB_DONE, SSB_CONTINUE, SSB_UNKNOWN }; + + + +/************************************************* +* Find the minimum subject length for a group * +*************************************************/ + +/* Scan a parenthesized group and compute the minimum length of subject that +is needed to match it. This is a lower bound; it does not mean there is a +string of that length that matches. In UTF8 mode, the result is in characters +rather than bytes. + +Arguments: + re compiled pattern block + code pointer to start of group (the bracket) + startcode pointer to start of the whole pattern's code + options the compiling options + recurses chain of recurse_check to catch mutual recursion + countptr pointer to call count (to catch over complexity) + +Returns: the minimum length + -1 if \C in UTF-8 mode or (*ACCEPT) was encountered + -2 internal error (missing capturing bracket) + -3 internal error (opcode not listed) +*/ + +static int +find_minlength(const REAL_PCRE *re, const pcre_uchar *code, + const pcre_uchar *startcode, int options, recurse_check *recurses, + int *countptr) +{ +int length = -1; +/* PCRE_UTF16 has the same value as PCRE_UTF8. */ +BOOL utf = (options & PCRE_UTF8) != 0; +BOOL had_recurse = FALSE; +recurse_check this_recurse; +register int branchlength = 0; +register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE; + +if ((*countptr)++ > 1000) return -1; /* too complex */ + +if (*code == OP_CBRA || *code == OP_SCBRA || + *code == OP_CBRAPOS || *code == OP_SCBRAPOS) cc += IMM2_SIZE; + +/* Scan along the opcodes for this branch. If we get to the end of the +branch, check the length against that of the other branches. */ + +for (;;) + { + int d, min; + pcre_uchar *cs, *ce; + register pcre_uchar op = *cc; + + switch (op) + { + case OP_COND: + case OP_SCOND: + + /* If there is only one branch in a condition, the implied branch has zero + length, so we don't add anything. This covers the DEFINE "condition" + automatically. */ + + cs = cc + GET(cc, 1); + if (*cs != OP_ALT) + { + cc = cs + 1 + LINK_SIZE; + break; + } + + /* Otherwise we can fall through and treat it the same as any other + subpattern. */ + + case OP_CBRA: + case OP_SCBRA: + case OP_BRA: + case OP_SBRA: + case OP_CBRAPOS: + case OP_SCBRAPOS: + case OP_BRAPOS: + case OP_SBRAPOS: + case OP_ONCE: + case OP_ONCE_NC: + d = find_minlength(re, cc, startcode, options, recurses, countptr); + if (d < 0) return d; + branchlength += d; + do cc += GET(cc, 1); while (*cc == OP_ALT); + cc += 1 + LINK_SIZE; + break; + + /* ACCEPT makes things far too complicated; we have to give up. */ + + case OP_ACCEPT: + case OP_ASSERT_ACCEPT: + return -1; + + /* Reached end of a branch; if it's a ket it is the end of a nested + call. If it's ALT it is an alternation in a nested call. If it is END it's + the end of the outer call. All can be handled by the same code. If an + ACCEPT was previously encountered, use the length that was in force at that + time, and pass back the shortest ACCEPT length. */ + + case OP_ALT: + case OP_KET: + case OP_KETRMAX: + case OP_KETRMIN: + case OP_KETRPOS: + case OP_END: + if (length < 0 || (!had_recurse && branchlength < length)) + length = branchlength; + if (op != OP_ALT) return length; + cc += 1 + LINK_SIZE; + branchlength = 0; + had_recurse = FALSE; + break; + + /* Skip over assertive subpatterns */ + + case OP_ASSERT: + case OP_ASSERT_NOT: + case OP_ASSERTBACK: + case OP_ASSERTBACK_NOT: + do cc += GET(cc, 1); while (*cc == OP_ALT); + /* Fall through */ + + /* Skip over things that don't match chars */ + + case OP_REVERSE: + case OP_CREF: + case OP_DNCREF: + case OP_RREF: + case OP_DNRREF: + case OP_DEF: + case OP_CALLOUT: + case OP_SOD: + case OP_SOM: + case OP_EOD: + case OP_EODN: + case OP_CIRC: + case OP_CIRCM: + case OP_DOLL: + case OP_DOLLM: + case OP_NOT_WORD_BOUNDARY: + case OP_WORD_BOUNDARY: + cc += PRIV(OP_lengths)[*cc]; + break; + + /* Skip over a subpattern that has a {0} or {0,x} quantifier */ + + case OP_BRAZERO: + case OP_BRAMINZERO: + case OP_BRAPOSZERO: + case OP_SKIPZERO: + cc += PRIV(OP_lengths)[*cc]; + do cc += GET(cc, 1); while (*cc == OP_ALT); + cc += 1 + LINK_SIZE; + break; + + /* Handle literal characters and + repetitions */ + + case OP_CHAR: + case OP_CHARI: + case OP_NOT: + case OP_NOTI: + case OP_PLUS: + case OP_PLUSI: + case OP_MINPLUS: + case OP_MINPLUSI: + case OP_POSPLUS: + case OP_POSPLUSI: + case OP_NOTPLUS: + case OP_NOTPLUSI: + case OP_NOTMINPLUS: + case OP_NOTMINPLUSI: + case OP_NOTPOSPLUS: + case OP_NOTPOSPLUSI: + branchlength++; + cc += 2; +#ifdef SUPPORT_UTF + if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]); +#endif + break; + + case OP_TYPEPLUS: + case OP_TYPEMINPLUS: + case OP_TYPEPOSPLUS: + branchlength++; + cc += (cc[1] == OP_PROP || cc[1] == OP_NOTPROP)? 4 : 2; + break; + + /* Handle exact repetitions. The count is already in characters, but we + need to skip over a multibyte character in UTF8 mode. */ + + case OP_EXACT: + case OP_EXACTI: + case OP_NOTEXACT: + case OP_NOTEXACTI: + branchlength += GET2(cc,1); + cc += 2 + IMM2_SIZE; +#ifdef SUPPORT_UTF + if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]); +#endif + break; + + case OP_TYPEEXACT: + branchlength += GET2(cc,1); + cc += 2 + IMM2_SIZE + ((cc[1 + IMM2_SIZE] == OP_PROP + || cc[1 + IMM2_SIZE] == OP_NOTPROP)? 2 : 0); + break; + + /* Handle single-char non-literal matchers */ + + case OP_PROP: + case OP_NOTPROP: + cc += 2; + /* Fall through */ + + case OP_NOT_DIGIT: + case OP_DIGIT: + case OP_NOT_WHITESPACE: + case OP_WHITESPACE: + case OP_NOT_WORDCHAR: + case OP_WORDCHAR: + case OP_ANY: + case OP_ALLANY: + case OP_EXTUNI: + case OP_HSPACE: + case OP_NOT_HSPACE: + case OP_VSPACE: + case OP_NOT_VSPACE: + branchlength++; + cc++; + break; + + /* "Any newline" might match two characters, but it also might match just + one. */ + + case OP_ANYNL: + branchlength += 1; + cc++; + break; + + /* The single-byte matcher means we can't proceed in UTF-8 mode. (In + non-UTF-8 mode \C will actually be turned into OP_ALLANY, so won't ever + appear, but leave the code, just in case.) */ + + case OP_ANYBYTE: +#ifdef SUPPORT_UTF + if (utf) return -1; +#endif + branchlength++; + cc++; + break; + + /* For repeated character types, we have to test for \p and \P, which have + an extra two bytes of parameters. */ + + case OP_TYPESTAR: + case OP_TYPEMINSTAR: + case OP_TYPEQUERY: + case OP_TYPEMINQUERY: + case OP_TYPEPOSSTAR: + case OP_TYPEPOSQUERY: + if (cc[1] == OP_PROP || cc[1] == OP_NOTPROP) cc += 2; + cc += PRIV(OP_lengths)[op]; + break; + + case OP_TYPEUPTO: + case OP_TYPEMINUPTO: + case OP_TYPEPOSUPTO: + if (cc[1 + IMM2_SIZE] == OP_PROP + || cc[1 + IMM2_SIZE] == OP_NOTPROP) cc += 2; + cc += PRIV(OP_lengths)[op]; + break; + + /* Check a class for variable quantification */ + + case OP_CLASS: + case OP_NCLASS: +#if defined SUPPORT_UTF || defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + case OP_XCLASS: + /* The original code caused an unsigned overflow in 64 bit systems, + so now we use a conditional statement. */ + if (op == OP_XCLASS) + cc += GET(cc, 1); + else + cc += PRIV(OP_lengths)[OP_CLASS]; +#else + cc += PRIV(OP_lengths)[OP_CLASS]; +#endif + + switch (*cc) + { + case OP_CRPLUS: + case OP_CRMINPLUS: + case OP_CRPOSPLUS: + branchlength++; + /* Fall through */ + + case OP_CRSTAR: + case OP_CRMINSTAR: + case OP_CRQUERY: + case OP_CRMINQUERY: + case OP_CRPOSSTAR: + case OP_CRPOSQUERY: + cc++; + break; + + case OP_CRRANGE: + case OP_CRMINRANGE: + case OP_CRPOSRANGE: + branchlength += GET2(cc,1); + cc += 1 + 2 * IMM2_SIZE; + break; + + default: + branchlength++; + break; + } + break; + + /* Backreferences and subroutine calls are treated in the same way: we find + the minimum length for the subpattern. A recursion, however, causes an + a flag to be set that causes the length of this branch to be ignored. The + logic is that a recursion can only make sense if there is another + alternation that stops the recursing. That will provide the minimum length + (when no recursion happens). A backreference within the group that it is + referencing behaves in the same way. + + If PCRE_JAVASCRIPT_COMPAT is set, a backreference to an unset bracket + matches an empty string (by default it causes a matching failure), so in + that case we must set the minimum length to zero. */ + + case OP_DNREF: /* Duplicate named pattern back reference */ + case OP_DNREFI: + if ((options & PCRE_JAVASCRIPT_COMPAT) == 0) + { + int count = GET2(cc, 1+IMM2_SIZE); + pcre_uchar *slot = (pcre_uchar *)re + + re->name_table_offset + GET2(cc, 1) * re->name_entry_size; + d = INT_MAX; + while (count-- > 0) + { + ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(slot, 0)); + if (cs == NULL) return -2; + do ce += GET(ce, 1); while (*ce == OP_ALT); + if (cc > cs && cc < ce) /* Simple recursion */ + { + d = 0; + had_recurse = TRUE; + break; + } + else + { + recurse_check *r = recurses; + for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break; + if (r != NULL) /* Mutual recursion */ + { + d = 0; + had_recurse = TRUE; + break; + } + else + { + int dd; + this_recurse.prev = recurses; + this_recurse.group = cs; + dd = find_minlength(re, cs, startcode, options, &this_recurse, + countptr); + if (dd < d) d = dd; + } + } + slot += re->name_entry_size; + } + } + else d = 0; + cc += 1 + 2*IMM2_SIZE; + goto REPEAT_BACK_REFERENCE; + + case OP_REF: /* Single back reference */ + case OP_REFI: + if ((options & PCRE_JAVASCRIPT_COMPAT) == 0) + { + ce = cs = (pcre_uchar *)PRIV(find_bracket)(startcode, utf, GET2(cc, 1)); + if (cs == NULL) return -2; + do ce += GET(ce, 1); while (*ce == OP_ALT); + if (cc > cs && cc < ce) /* Simple recursion */ + { + d = 0; + had_recurse = TRUE; + } + else + { + recurse_check *r = recurses; + for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break; + if (r != NULL) /* Mutual recursion */ + { + d = 0; + had_recurse = TRUE; + } + else + { + this_recurse.prev = recurses; + this_recurse.group = cs; + d = find_minlength(re, cs, startcode, options, &this_recurse, + countptr); + } + } + } + else d = 0; + cc += 1 + IMM2_SIZE; + + /* Handle repeated back references */ + + REPEAT_BACK_REFERENCE: + switch (*cc) + { + case OP_CRSTAR: + case OP_CRMINSTAR: + case OP_CRQUERY: + case OP_CRMINQUERY: + case OP_CRPOSSTAR: + case OP_CRPOSQUERY: + min = 0; + cc++; + break; + + case OP_CRPLUS: + case OP_CRMINPLUS: + case OP_CRPOSPLUS: + min = 1; + cc++; + break; + + case OP_CRRANGE: + case OP_CRMINRANGE: + case OP_CRPOSRANGE: + min = GET2(cc, 1); + cc += 1 + 2 * IMM2_SIZE; + break; + + default: + min = 1; + break; + } + + branchlength += min * d; + break; + + /* We can easily detect direct recursion, but not mutual recursion. This is + caught by a recursion depth count. */ + + case OP_RECURSE: + cs = ce = (pcre_uchar *)startcode + GET(cc, 1); + do ce += GET(ce, 1); while (*ce == OP_ALT); + if (cc > cs && cc < ce) /* Simple recursion */ + had_recurse = TRUE; + else + { + recurse_check *r = recurses; + for (r = recurses; r != NULL; r = r->prev) if (r->group == cs) break; + if (r != NULL) /* Mutual recursion */ + had_recurse = TRUE; + else + { + this_recurse.prev = recurses; + this_recurse.group = cs; + branchlength += find_minlength(re, cs, startcode, options, + &this_recurse, countptr); + } + } + cc += 1 + LINK_SIZE; + break; + + /* Anything else does not or need not match a character. We can get the + item's length from the table, but for those that can match zero occurrences + of a character, we must take special action for UTF-8 characters. As it + happens, the "NOT" versions of these opcodes are used at present only for + ASCII characters, so they could be omitted from this list. However, in + future that may change, so we include them here so as not to leave a + gotcha for a future maintainer. */ + + case OP_UPTO: + case OP_UPTOI: + case OP_NOTUPTO: + case OP_NOTUPTOI: + case OP_MINUPTO: + case OP_MINUPTOI: + case OP_NOTMINUPTO: + case OP_NOTMINUPTOI: + case OP_POSUPTO: + case OP_POSUPTOI: + case OP_NOTPOSUPTO: + case OP_NOTPOSUPTOI: + + case OP_STAR: + case OP_STARI: + case OP_NOTSTAR: + case OP_NOTSTARI: + case OP_MINSTAR: + case OP_MINSTARI: + case OP_NOTMINSTAR: + case OP_NOTMINSTARI: + case OP_POSSTAR: + case OP_POSSTARI: + case OP_NOTPOSSTAR: + case OP_NOTPOSSTARI: + + case OP_QUERY: + case OP_QUERYI: + case OP_NOTQUERY: + case OP_NOTQUERYI: + case OP_MINQUERY: + case OP_MINQUERYI: + case OP_NOTMINQUERY: + case OP_NOTMINQUERYI: + case OP_POSQUERY: + case OP_POSQUERYI: + case OP_NOTPOSQUERY: + case OP_NOTPOSQUERYI: + + cc += PRIV(OP_lengths)[op]; +#ifdef SUPPORT_UTF + if (utf && HAS_EXTRALEN(cc[-1])) cc += GET_EXTRALEN(cc[-1]); +#endif + break; + + /* Skip these, but we need to add in the name length. */ + + case OP_MARK: + case OP_PRUNE_ARG: + case OP_SKIP_ARG: + case OP_THEN_ARG: + cc += PRIV(OP_lengths)[op] + cc[1]; + break; + + /* The remaining opcodes are just skipped over. */ + + case OP_CLOSE: + case OP_COMMIT: + case OP_FAIL: + case OP_PRUNE: + case OP_SET_SOM: + case OP_SKIP: + case OP_THEN: + cc += PRIV(OP_lengths)[op]; + break; + + /* This should not occur: we list all opcodes explicitly so that when + new ones get added they are properly considered. */ + + default: + return -3; + } + } +/* Control never gets here */ +} + + + +/************************************************* +* Set a bit and maybe its alternate case * +*************************************************/ + +/* Given a character, set its first byte's bit in the table, and also the +corresponding bit for the other version of a letter if we are caseless. In +UTF-8 mode, for characters greater than 127, we can only do the caseless thing +when Unicode property support is available. + +Arguments: + start_bits points to the bit map + p points to the character + caseless the caseless flag + cd the block with char table pointers + utf TRUE for UTF-8 / UTF-16 / UTF-32 mode + +Returns: pointer after the character +*/ + +static const pcre_uchar * +set_table_bit(pcre_uint8 *start_bits, const pcre_uchar *p, BOOL caseless, + compile_data *cd, BOOL utf) +{ +pcre_uint32 c = *p; + +#ifdef COMPILE_PCRE8 +SET_BIT(c); + +#ifdef SUPPORT_UTF +if (utf && c > 127) + { + GETCHARINC(c, p); +#ifdef SUPPORT_UCP + if (caseless) + { + pcre_uchar buff[6]; + c = UCD_OTHERCASE(c); + (void)PRIV(ord2utf)(c, buff); + SET_BIT(buff[0]); + } +#endif /* Not SUPPORT_UCP */ + return p; + } +#else /* Not SUPPORT_UTF */ +(void)(utf); /* Stops warning for unused parameter */ +#endif /* SUPPORT_UTF */ + +/* Not UTF-8 mode, or character is less than 127. */ + +if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]); +return p + 1; +#endif /* COMPILE_PCRE8 */ + +#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32 +if (c > 0xff) + { + c = 0xff; + caseless = FALSE; + } +SET_BIT(c); + +#ifdef SUPPORT_UTF +if (utf && c > 127) + { + GETCHARINC(c, p); +#ifdef SUPPORT_UCP + if (caseless) + { + c = UCD_OTHERCASE(c); + if (c > 0xff) + c = 0xff; + SET_BIT(c); + } +#endif /* SUPPORT_UCP */ + return p; + } +#else /* Not SUPPORT_UTF */ +(void)(utf); /* Stops warning for unused parameter */ +#endif /* SUPPORT_UTF */ + +if (caseless && (cd->ctypes[c] & ctype_letter) != 0) SET_BIT(cd->fcc[c]); +return p + 1; +#endif +} + + + +/************************************************* +* Set bits for a positive character type * +*************************************************/ + +/* This function sets starting bits for a character type. In UTF-8 mode, we can +only do a direct setting for bytes less than 128, as otherwise there can be +confusion with bytes in the middle of UTF-8 characters. In a "traditional" +environment, the tables will only recognize ASCII characters anyway, but in at +least one Windows environment, some higher bytes bits were set in the tables. +So we deal with that case by considering the UTF-8 encoding. + +Arguments: + start_bits the starting bitmap + cbit type the type of character wanted + table_limit 32 for non-UTF-8; 16 for UTF-8 + cd the block with char table pointers + +Returns: nothing +*/ + +static void +set_type_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit, + compile_data *cd) +{ +register pcre_uint32 c; +for (c = 0; c < table_limit; c++) start_bits[c] |= cd->cbits[c+cbit_type]; +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 +if (table_limit == 32) return; +for (c = 128; c < 256; c++) + { + if ((cd->cbits[c/8] & (1 << (c&7))) != 0) + { + pcre_uchar buff[6]; + (void)PRIV(ord2utf)(c, buff); + SET_BIT(buff[0]); + } + } +#endif +} + + +/************************************************* +* Set bits for a negative character type * +*************************************************/ + +/* This function sets starting bits for a negative character type such as \D. +In UTF-8 mode, we can only do a direct setting for bytes less than 128, as +otherwise there can be confusion with bytes in the middle of UTF-8 characters. +Unlike in the positive case, where we can set appropriate starting bits for +specific high-valued UTF-8 characters, in this case we have to set the bits for +all high-valued characters. The lowest is 0xc2, but we overkill by starting at +0xc0 (192) for simplicity. + +Arguments: + start_bits the starting bitmap + cbit type the type of character wanted + table_limit 32 for non-UTF-8; 16 for UTF-8 + cd the block with char table pointers + +Returns: nothing +*/ + +static void +set_nottype_bits(pcre_uint8 *start_bits, int cbit_type, unsigned int table_limit, + compile_data *cd) +{ +register pcre_uint32 c; +for (c = 0; c < table_limit; c++) start_bits[c] |= ~cd->cbits[c+cbit_type]; +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 +if (table_limit != 32) for (c = 24; c < 32; c++) start_bits[c] = 0xff; +#endif +} + + + +/************************************************* +* Create bitmap of starting bytes * +*************************************************/ + +/* This function scans a compiled unanchored expression recursively and +attempts to build a bitmap of the set of possible starting bytes. As time goes +by, we may be able to get more clever at doing this. The SSB_CONTINUE return is +useful for parenthesized groups in patterns such as (a*)b where the group +provides some optional starting bytes but scanning must continue at the outer +level to find at least one mandatory byte. At the outermost level, this +function fails unless the result is SSB_DONE. + +Arguments: + code points to an expression + start_bits points to a 32-byte table, initialized to 0 + utf TRUE if in UTF-8 / UTF-16 / UTF-32 mode + cd the block with char table pointers + +Returns: SSB_FAIL => Failed to find any starting bytes + SSB_DONE => Found mandatory starting bytes + SSB_CONTINUE => Found optional starting bytes + SSB_UNKNOWN => Hit an unrecognized opcode +*/ + +static int +set_start_bits(const pcre_uchar *code, pcre_uint8 *start_bits, BOOL utf, + compile_data *cd) +{ +register pcre_uint32 c; +int yield = SSB_DONE; +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 +int table_limit = utf? 16:32; +#else +int table_limit = 32; +#endif + +#if 0 +/* ========================================================================= */ +/* The following comment and code was inserted in January 1999. In May 2006, +when it was observed to cause compiler warnings about unused values, I took it +out again. If anybody is still using OS/2, they will have to put it back +manually. */ + +/* 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; +/* ========================================================================= */ +#endif + +do + { + BOOL try_next = TRUE; + const pcre_uchar *tcode = code + 1 + LINK_SIZE; + + if (*code == OP_CBRA || *code == OP_SCBRA || + *code == OP_CBRAPOS || *code == OP_SCBRAPOS) tcode += IMM2_SIZE; + + while (try_next) /* Loop for items in this branch */ + { + int rc; + + switch(*tcode) + { + /* If we reach something we don't understand, it means a new opcode has + been created that hasn't been added to this code. Hopefully this problem + will be discovered during testing. */ + + default: + return SSB_UNKNOWN; + + /* Fail for a valid opcode that implies no starting bits. */ + + case OP_ACCEPT: + case OP_ASSERT_ACCEPT: + case OP_ALLANY: + case OP_ANY: + case OP_ANYBYTE: + case OP_CIRC: + case OP_CIRCM: + case OP_CLOSE: + case OP_COMMIT: + case OP_COND: + case OP_CREF: + case OP_DEF: + case OP_DNCREF: + case OP_DNREF: + case OP_DNREFI: + case OP_DNRREF: + case OP_DOLL: + case OP_DOLLM: + case OP_END: + case OP_EOD: + case OP_EODN: + case OP_EXTUNI: + case OP_FAIL: + case OP_MARK: + case OP_NOT: + case OP_NOTEXACT: + case OP_NOTEXACTI: + case OP_NOTI: + case OP_NOTMINPLUS: + case OP_NOTMINPLUSI: + case OP_NOTMINQUERY: + case OP_NOTMINQUERYI: + case OP_NOTMINSTAR: + case OP_NOTMINSTARI: + case OP_NOTMINUPTO: + case OP_NOTMINUPTOI: + case OP_NOTPLUS: + case OP_NOTPLUSI: + case OP_NOTPOSPLUS: + case OP_NOTPOSPLUSI: + case OP_NOTPOSQUERY: + case OP_NOTPOSQUERYI: + case OP_NOTPOSSTAR: + case OP_NOTPOSSTARI: + case OP_NOTPOSUPTO: + case OP_NOTPOSUPTOI: + case OP_NOTPROP: + case OP_NOTQUERY: + case OP_NOTQUERYI: + case OP_NOTSTAR: + case OP_NOTSTARI: + case OP_NOTUPTO: + case OP_NOTUPTOI: + case OP_NOT_HSPACE: + case OP_NOT_VSPACE: + case OP_PRUNE: + case OP_PRUNE_ARG: + case OP_RECURSE: + case OP_REF: + case OP_REFI: + case OP_REVERSE: + case OP_RREF: + case OP_SCOND: + case OP_SET_SOM: + case OP_SKIP: + case OP_SKIP_ARG: + case OP_SOD: + case OP_SOM: + case OP_THEN: + case OP_THEN_ARG: + return SSB_FAIL; + + /* A "real" property test implies no starting bits, but the fake property + PT_CLIST identifies a list of characters. These lists are short, as they + are used for characters with more than one "other case", so there is no + point in recognizing them for OP_NOTPROP. */ + + case OP_PROP: + if (tcode[1] != PT_CLIST) return SSB_FAIL; + { + const pcre_uint32 *p = PRIV(ucd_caseless_sets) + tcode[2]; + while ((c = *p++) < NOTACHAR) + { +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 + if (utf) + { + pcre_uchar buff[6]; + (void)PRIV(ord2utf)(c, buff); + c = buff[0]; + } +#endif + if (c > 0xff) SET_BIT(0xff); else SET_BIT(c); + } + } + try_next = FALSE; + break; + + /* We can ignore word boundary tests. */ + + case OP_WORD_BOUNDARY: + case OP_NOT_WORD_BOUNDARY: + tcode++; + break; + + /* If we hit a bracket or a positive lookahead assertion, recurse to set + bits from within the subpattern. If it can't find anything, we have to + give up. If it finds some mandatory character(s), we are done for this + branch. Otherwise, carry on scanning after the subpattern. */ + + case OP_BRA: + case OP_SBRA: + case OP_CBRA: + case OP_SCBRA: + case OP_BRAPOS: + case OP_SBRAPOS: + case OP_CBRAPOS: + case OP_SCBRAPOS: + case OP_ONCE: + case OP_ONCE_NC: + case OP_ASSERT: + rc = set_start_bits(tcode, start_bits, utf, cd); + if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc; + if (rc == SSB_DONE) try_next = FALSE; else + { + do tcode += GET(tcode, 1); while (*tcode == OP_ALT); + tcode += 1 + LINK_SIZE; + } + break; + + /* If we hit ALT or KET, it means we haven't found anything mandatory in + this branch, though we might have found something optional. For ALT, we + continue with the next alternative, but we have to arrange that the final + result from subpattern is SSB_CONTINUE rather than SSB_DONE. For KET, + return SSB_CONTINUE: if this is the top level, that indicates failure, + but after a nested subpattern, it causes scanning to continue. */ + + case OP_ALT: + yield = SSB_CONTINUE; + try_next = FALSE; + break; + + case OP_KET: + case OP_KETRMAX: + case OP_KETRMIN: + case OP_KETRPOS: + return SSB_CONTINUE; + + /* Skip over callout */ + + case OP_CALLOUT: + tcode += 2 + 2*LINK_SIZE; + break; + + /* Skip over lookbehind and negative lookahead assertions */ + + case OP_ASSERT_NOT: + case OP_ASSERTBACK: + case OP_ASSERTBACK_NOT: + do tcode += GET(tcode, 1); while (*tcode == OP_ALT); + tcode += 1 + LINK_SIZE; + break; + + /* BRAZERO does the bracket, but carries on. */ + + case OP_BRAZERO: + case OP_BRAMINZERO: + case OP_BRAPOSZERO: + rc = set_start_bits(++tcode, start_bits, utf, cd); + if (rc == SSB_FAIL || rc == SSB_UNKNOWN) return rc; +/* ========================================================================= + See the comment at the head of this function concerning the next line, + which was an old fudge for the benefit of OS/2. + dummy = 1; + ========================================================================= */ + do tcode += GET(tcode,1); while (*tcode == OP_ALT); + tcode += 1 + LINK_SIZE; + break; + + /* SKIPZERO skips the bracket. */ + + case OP_SKIPZERO: + tcode++; + do tcode += GET(tcode,1); while (*tcode == OP_ALT); + tcode += 1 + LINK_SIZE; + break; + + /* Single-char * or ? sets the bit and tries the next item */ + + case OP_STAR: + case OP_MINSTAR: + case OP_POSSTAR: + case OP_QUERY: + case OP_MINQUERY: + case OP_POSQUERY: + tcode = set_table_bit(start_bits, tcode + 1, FALSE, cd, utf); + break; + + case OP_STARI: + case OP_MINSTARI: + case OP_POSSTARI: + case OP_QUERYI: + case OP_MINQUERYI: + case OP_POSQUERYI: + tcode = set_table_bit(start_bits, tcode + 1, TRUE, cd, utf); + break; + + /* Single-char upto sets the bit and tries the next */ + + case OP_UPTO: + case OP_MINUPTO: + case OP_POSUPTO: + tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, FALSE, cd, utf); + break; + + case OP_UPTOI: + case OP_MINUPTOI: + case OP_POSUPTOI: + tcode = set_table_bit(start_bits, tcode + 1 + IMM2_SIZE, TRUE, cd, utf); + break; + + /* At least one single char sets the bit and stops */ + + case OP_EXACT: + tcode += IMM2_SIZE; + /* Fall through */ + case OP_CHAR: + case OP_PLUS: + case OP_MINPLUS: + case OP_POSPLUS: + (void)set_table_bit(start_bits, tcode + 1, FALSE, cd, utf); + try_next = FALSE; + break; + + case OP_EXACTI: + tcode += IMM2_SIZE; + /* Fall through */ + case OP_CHARI: + case OP_PLUSI: + case OP_MINPLUSI: + case OP_POSPLUSI: + (void)set_table_bit(start_bits, tcode + 1, TRUE, cd, utf); + try_next = FALSE; + break; + + /* Special spacing and line-terminating items. These recognize specific + lists of characters. The difference between VSPACE and ANYNL is that the + latter can match the two-character CRLF sequence, but that is not + relevant for finding the first character, so their code here is + identical. */ + + case OP_HSPACE: + SET_BIT(CHAR_HT); + SET_BIT(CHAR_SPACE); +#ifdef SUPPORT_UTF + if (utf) + { +#ifdef COMPILE_PCRE8 + SET_BIT(0xC2); /* For U+00A0 */ + SET_BIT(0xE1); /* For U+1680, U+180E */ + SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */ + SET_BIT(0xE3); /* For U+3000 */ +#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(0xA0); + SET_BIT(0xFF); /* For characters > 255 */ +#endif /* COMPILE_PCRE[8|16|32] */ + } + else +#endif /* SUPPORT_UTF */ + { +#ifndef EBCDIC + SET_BIT(0xA0); +#endif /* Not EBCDIC */ +#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(0xFF); /* For characters > 255 */ +#endif /* COMPILE_PCRE[16|32] */ + } + try_next = FALSE; + break; + + case OP_ANYNL: + case OP_VSPACE: + SET_BIT(CHAR_LF); + SET_BIT(CHAR_VT); + SET_BIT(CHAR_FF); + SET_BIT(CHAR_CR); +#ifdef SUPPORT_UTF + if (utf) + { +#ifdef COMPILE_PCRE8 + SET_BIT(0xC2); /* For U+0085 */ + SET_BIT(0xE2); /* For U+2028, U+2029 */ +#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(CHAR_NEL); + SET_BIT(0xFF); /* For characters > 255 */ +#endif /* COMPILE_PCRE[8|16|32] */ + } + else +#endif /* SUPPORT_UTF */ + { + SET_BIT(CHAR_NEL); +#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(0xFF); /* For characters > 255 */ +#endif + } + try_next = FALSE; + break; + + /* Single character types set the bits and stop. Note that if PCRE_UCP + is set, we do not see these op codes because \d etc are converted to + properties. Therefore, these apply in the case when only characters less + than 256 are recognized to match the types. */ + + case OP_NOT_DIGIT: + set_nottype_bits(start_bits, cbit_digit, table_limit, cd); + try_next = FALSE; + break; + + case OP_DIGIT: + set_type_bits(start_bits, cbit_digit, table_limit, cd); + try_next = FALSE; + break; + + /* The cbit_space table has vertical tab as whitespace; we no longer + have to play fancy tricks because Perl added VT to its whitespace at + release 5.18. PCRE added it at release 8.34. */ + + case OP_NOT_WHITESPACE: + set_nottype_bits(start_bits, cbit_space, table_limit, cd); + try_next = FALSE; + break; + + case OP_WHITESPACE: + set_type_bits(start_bits, cbit_space, table_limit, cd); + try_next = FALSE; + break; + + case OP_NOT_WORDCHAR: + set_nottype_bits(start_bits, cbit_word, table_limit, cd); + try_next = FALSE; + break; + + case OP_WORDCHAR: + set_type_bits(start_bits, cbit_word, table_limit, cd); + try_next = FALSE; + 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: + case OP_TYPEPOSPLUS: + tcode++; + break; + + case OP_TYPEEXACT: + tcode += 1 + IMM2_SIZE; + break; + + /* Zero or more repeats of character types set the bits and then + try again. */ + + case OP_TYPEUPTO: + case OP_TYPEMINUPTO: + case OP_TYPEPOSUPTO: + tcode += IMM2_SIZE; /* Fall through */ + + case OP_TYPESTAR: + case OP_TYPEMINSTAR: + case OP_TYPEPOSSTAR: + case OP_TYPEQUERY: + case OP_TYPEMINQUERY: + case OP_TYPEPOSQUERY: + switch(tcode[1]) + { + default: + case OP_ANY: + case OP_ALLANY: + return SSB_FAIL; + + case OP_HSPACE: + SET_BIT(CHAR_HT); + SET_BIT(CHAR_SPACE); +#ifdef SUPPORT_UTF + if (utf) + { +#ifdef COMPILE_PCRE8 + SET_BIT(0xC2); /* For U+00A0 */ + SET_BIT(0xE1); /* For U+1680, U+180E */ + SET_BIT(0xE2); /* For U+2000 - U+200A, U+202F, U+205F */ + SET_BIT(0xE3); /* For U+3000 */ +#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(0xA0); + SET_BIT(0xFF); /* For characters > 255 */ +#endif /* COMPILE_PCRE[8|16|32] */ + } + else +#endif /* SUPPORT_UTF */ +#ifndef EBCDIC + SET_BIT(0xA0); +#endif /* Not EBCDIC */ + break; + + case OP_ANYNL: + case OP_VSPACE: + SET_BIT(CHAR_LF); + SET_BIT(CHAR_VT); + SET_BIT(CHAR_FF); + SET_BIT(CHAR_CR); +#ifdef SUPPORT_UTF + if (utf) + { +#ifdef COMPILE_PCRE8 + SET_BIT(0xC2); /* For U+0085 */ + SET_BIT(0xE2); /* For U+2028, U+2029 */ +#elif defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(CHAR_NEL); + SET_BIT(0xFF); /* For characters > 255 */ +#endif /* COMPILE_PCRE16 */ + } + else +#endif /* SUPPORT_UTF */ + SET_BIT(CHAR_NEL); + break; + + case OP_NOT_DIGIT: + set_nottype_bits(start_bits, cbit_digit, table_limit, cd); + break; + + case OP_DIGIT: + set_type_bits(start_bits, cbit_digit, table_limit, cd); + break; + + /* The cbit_space table has vertical tab as whitespace; we no longer + have to play fancy tricks because Perl added VT to its whitespace at + release 5.18. PCRE added it at release 8.34. */ + + case OP_NOT_WHITESPACE: + set_nottype_bits(start_bits, cbit_space, table_limit, cd); + break; + + case OP_WHITESPACE: + set_type_bits(start_bits, cbit_space, table_limit, cd); + break; + + case OP_NOT_WORDCHAR: + set_nottype_bits(start_bits, cbit_word, table_limit, cd); + break; + + case OP_WORDCHAR: + set_type_bits(start_bits, cbit_word, table_limit, cd); + break; + } + + tcode += 2; + break; + + /* Character class where all the information is in a bit map: set the + bits and either carry on or not, according to the repeat count. If it was + a negative class, and we are operating with UTF-8 characters, any byte + with a value >= 0xc4 is a potentially valid starter because it starts a + character with a value > 255. */ + +#if defined SUPPORT_UTF || !defined COMPILE_PCRE8 + case OP_XCLASS: + if ((tcode[1 + LINK_SIZE] & XCL_HASPROP) != 0) + return SSB_FAIL; + /* All bits are set. */ + if ((tcode[1 + LINK_SIZE] & XCL_MAP) == 0 && (tcode[1 + LINK_SIZE] & XCL_NOT) != 0) + return SSB_FAIL; +#endif + /* Fall through */ + + case OP_NCLASS: +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 + if (utf) + { + start_bits[24] |= 0xf0; /* Bits for 0xc4 - 0xc8 */ + memset(start_bits+25, 0xff, 7); /* Bits for 0xc9 - 0xff */ + } +#endif +#if defined COMPILE_PCRE16 || defined COMPILE_PCRE32 + SET_BIT(0xFF); /* For characters > 255 */ +#endif + /* Fall through */ + + case OP_CLASS: + { + pcre_uint8 *map; +#if defined SUPPORT_UTF || !defined COMPILE_PCRE8 + map = NULL; + if (*tcode == OP_XCLASS) + { + if ((tcode[1 + LINK_SIZE] & XCL_MAP) != 0) + map = (pcre_uint8 *)(tcode + 1 + LINK_SIZE + 1); + tcode += GET(tcode, 1); + } + else +#endif + { + tcode++; + map = (pcre_uint8 *)tcode; + tcode += 32 / sizeof(pcre_uchar); + } + + /* In UTF-8 mode, the bits in a bit map correspond to character + values, not to byte values. However, the bit map we are constructing is + for byte values. So we have to do a conversion for characters whose + value is > 127. In fact, there are only two possible starting bytes for + characters in the range 128 - 255. */ + +#if defined SUPPORT_UTF || !defined COMPILE_PCRE8 + if (map != NULL) +#endif + { +#if defined SUPPORT_UTF && defined COMPILE_PCRE8 + if (utf) + { + for (c = 0; c < 16; c++) start_bits[c] |= map[c]; + for (c = 128; c < 256; c++) + { + if ((map[c/8] & (1 << (c&7))) != 0) + { + int d = (c >> 6) | 0xc0; /* Set bit for this starter */ + start_bits[d/8] |= (1 << (d&7)); /* and then skip on to the */ + c = (c & 0xc0) + 0x40 - 1; /* next relevant character. */ + } + } + } + else +#endif + { + /* In non-UTF-8 mode, the two bit maps are completely compatible. */ + for (c = 0; c < 32; c++) start_bits[c] |= map[c]; + } + } + + /* Advance past the bit map, and act on what follows. For a zero + minimum repeat, continue; otherwise stop processing. */ + + switch (*tcode) + { + case OP_CRSTAR: + case OP_CRMINSTAR: + case OP_CRQUERY: + case OP_CRMINQUERY: + case OP_CRPOSSTAR: + case OP_CRPOSQUERY: + tcode++; + break; + + case OP_CRRANGE: + case OP_CRMINRANGE: + case OP_CRPOSRANGE: + if (GET2(tcode, 1) == 0) tcode += 1 + 2 * IMM2_SIZE; + else try_next = FALSE; + break; + + default: + try_next = FALSE; + break; + } + } + break; /* End of bitmap class handling */ + + } /* End of switch */ + } /* End of try_next loop */ + + code += GET(code, 1); /* Advance to next branch */ + } +while (*code == OP_ALT); +return yield; +} + + + + + +/************************************************* +* 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[16]_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[16]_extra block, with study_data filled in and + the appropriate flags set; + NULL on error or if no optimization possible +*/ + +#if defined COMPILE_PCRE8 +PCRE_EXP_DEFN pcre_extra * PCRE_CALL_CONVENTION +pcre_study(const pcre *external_re, int options, const char **errorptr) +#elif defined COMPILE_PCRE16 +PCRE_EXP_DEFN pcre16_extra * PCRE_CALL_CONVENTION +pcre16_study(const pcre16 *external_re, int options, const char **errorptr) +#elif defined COMPILE_PCRE32 +PCRE_EXP_DEFN pcre32_extra * PCRE_CALL_CONVENTION +pcre32_study(const pcre32 *external_re, int options, const char **errorptr) +#endif +{ +int min; +int count = 0; +BOOL bits_set = FALSE; +pcre_uint8 start_bits[32]; +PUBL(extra) *extra = NULL; +pcre_study_data *study; +const pcre_uint8 *tables; +pcre_uchar *code; +compile_data compile_block; +const REAL_PCRE *re = (const REAL_PCRE *)external_re; + + +*errorptr = NULL; + +if (re == NULL || re->magic_number != MAGIC_NUMBER) + { + *errorptr = "argument is not a compiled regular expression"; + return NULL; + } + +if ((re->flags & PCRE_MODE) == 0) + { +#if defined COMPILE_PCRE8 + *errorptr = "argument not compiled in 8 bit mode"; +#elif defined COMPILE_PCRE16 + *errorptr = "argument not compiled in 16 bit mode"; +#elif defined COMPILE_PCRE32 + *errorptr = "argument not compiled in 32 bit mode"; +#endif + return NULL; + } + +if ((options & ~PUBLIC_STUDY_OPTIONS) != 0) + { + *errorptr = "unknown or incorrect option bit(s) set"; + return NULL; + } + +code = (pcre_uchar *)re + re->name_table_offset + + (re->name_count * re->name_entry_size); + +/* For an anchored pattern, or an unanchored pattern that has a first char, or +a multiline pattern that matches only at "line starts", there is no point in +seeking a list of starting bytes. */ + +if ((re->options & PCRE_ANCHORED) == 0 && + (re->flags & (PCRE_FIRSTSET|PCRE_STARTLINE)) == 0) + { + int rc; + + /* Set the character tables in the block that is passed around */ + + tables = re->tables; + +#if defined COMPILE_PCRE8 + if (tables == NULL) + (void)pcre_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES, + (void *)(&tables)); +#elif defined COMPILE_PCRE16 + if (tables == NULL) + (void)pcre16_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES, + (void *)(&tables)); +#elif defined COMPILE_PCRE32 + if (tables == NULL) + (void)pcre32_fullinfo(external_re, NULL, PCRE_INFO_DEFAULT_TABLES, + (void *)(&tables)); +#endif + + compile_block.lcc = tables + lcc_offset; + compile_block.fcc = tables + fcc_offset; + compile_block.cbits = tables + cbits_offset; + compile_block.ctypes = tables + ctypes_offset; + + /* See if we can find a fixed set of initial characters for the pattern. */ + + memset(start_bits, 0, 32 * sizeof(pcre_uint8)); + rc = set_start_bits(code, start_bits, (re->options & PCRE_UTF8) != 0, + &compile_block); + bits_set = rc == SSB_DONE; + if (rc == SSB_UNKNOWN) + { + *errorptr = "internal error: opcode not recognized"; + return NULL; + } + } + +/* Find the minimum length of subject string. */ + +switch(min = find_minlength(re, code, code, re->options, NULL, &count)) + { + case -2: *errorptr = "internal error: missing capturing bracket"; return NULL; + case -3: *errorptr = "internal error: opcode not recognized"; return NULL; + default: break; + } + +/* If a set of starting bytes has been identified, or if the minimum length is +greater than zero, or if JIT optimization has been requested, or if +PCRE_STUDY_EXTRA_NEEDED is set, get a pcre[16]_extra block and a +pcre_study_data block. The study data is put in the latter, which is pointed to +by the former, which may also get additional data set later by the calling +program. At the moment, the size of pcre_study_data is fixed. We nevertheless +save it in a field for returning via the pcre_fullinfo() function so that if it +becomes variable in the future, we don't have to change that code. */ + +if (bits_set || min > 0 || (options & ( +#ifdef SUPPORT_JIT + PCRE_STUDY_JIT_COMPILE | PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE | + PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE | +#endif + PCRE_STUDY_EXTRA_NEEDED)) != 0) + { + extra = (PUBL(extra) *)(PUBL(malloc)) + (sizeof(PUBL(extra)) + sizeof(pcre_study_data)); + if (extra == NULL) + { + *errorptr = "failed to get memory"; + return NULL; + } + + study = (pcre_study_data *)((char *)extra + sizeof(PUBL(extra))); + extra->flags = PCRE_EXTRA_STUDY_DATA; + extra->study_data = study; + + study->size = sizeof(pcre_study_data); + study->flags = 0; + + /* Set the start bits always, to avoid unset memory errors if the + study data is written to a file, but set the flag only if any of the bits + are set, to save time looking when none are. */ + + if (bits_set) + { + study->flags |= PCRE_STUDY_MAPPED; + memcpy(study->start_bits, start_bits, sizeof(start_bits)); + } + else memset(study->start_bits, 0, 32 * sizeof(pcre_uint8)); + +#ifdef PCRE_DEBUG + if (bits_set) + { + pcre_uint8 *ptr = start_bits; + int i; + + printf("Start bits:\n"); + for (i = 0; i < 32; i++) + printf("%3d: %02x%s", i * 8, *ptr++, ((i + 1) & 0x7) != 0? " " : "\n"); + } +#endif + + /* Always set the minlength value in the block, because the JIT compiler + makes use of it. However, don't set the bit unless the length is greater than + zero - the interpretive pcre_exec() and pcre_dfa_exec() needn't waste time + checking the zero case. */ + + if (min > 0) + { + study->flags |= PCRE_STUDY_MINLEN; + study->minlength = min; + } + else study->minlength = 0; + + /* If JIT support was compiled and requested, attempt the JIT compilation. + If no starting bytes were found, and the minimum length is zero, and JIT + compilation fails, abandon the extra block and return NULL, unless + PCRE_STUDY_EXTRA_NEEDED is set. */ + +#ifdef SUPPORT_JIT + extra->executable_jit = NULL; + if ((options & PCRE_STUDY_JIT_COMPILE) != 0) + PRIV(jit_compile)(re, extra, JIT_COMPILE); + if ((options & PCRE_STUDY_JIT_PARTIAL_SOFT_COMPILE) != 0) + PRIV(jit_compile)(re, extra, JIT_PARTIAL_SOFT_COMPILE); + if ((options & PCRE_STUDY_JIT_PARTIAL_HARD_COMPILE) != 0) + PRIV(jit_compile)(re, extra, JIT_PARTIAL_HARD_COMPILE); + + if (study->flags == 0 && (extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) == 0 && + (options & PCRE_STUDY_EXTRA_NEEDED) == 0) + { +#if defined COMPILE_PCRE8 + pcre_free_study(extra); +#elif defined COMPILE_PCRE16 + pcre16_free_study(extra); +#elif defined COMPILE_PCRE32 + pcre32_free_study(extra); +#endif + extra = NULL; + } +#endif + } + +return extra; +} + + +/************************************************* +* Free the study data * +*************************************************/ + +/* This function frees the memory that was obtained by pcre_study(). + +Argument: a pointer to the pcre[16]_extra block +Returns: nothing +*/ + +#if defined COMPILE_PCRE8 +PCRE_EXP_DEFN void +pcre_free_study(pcre_extra *extra) +#elif defined COMPILE_PCRE16 +PCRE_EXP_DEFN void +pcre16_free_study(pcre16_extra *extra) +#elif defined COMPILE_PCRE32 +PCRE_EXP_DEFN void +pcre32_free_study(pcre32_extra *extra) +#endif +{ +if (extra == NULL) + return; +#ifdef SUPPORT_JIT +if ((extra->flags & PCRE_EXTRA_EXECUTABLE_JIT) != 0 && + extra->executable_jit != NULL) + PRIV(jit_free)(extra->executable_jit); +#endif +PUBL(free)(extra); +} + +/* End of pcre_study.c */ |