/************************************************* * 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 PCRE_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 int RECURSE depth 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, int recurse_depth) { int length = -1; /* PCRE_UTF16 has the same value as PCRE_UTF8. */ BOOL utf = (options & PCRE_UTF8) != 0; BOOL had_recurse = FALSE; register int branchlength = 0; register pcre_uchar *cc = (pcre_uchar *)code + 1 + LINK_SIZE; 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, recurse_depth); 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) { d = 0; had_recurse = TRUE; break; } else { int dd = find_minlength(re, cs, startcode, options, recurse_depth); 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) { d = 0; had_recurse = TRUE; } else { d = find_minlength(re, cs, startcode, options, recurse_depth); } } 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) || recurse_depth > 10) had_recurse = TRUE; else { branchlength += find_minlength(re, cs, startcode, options, recurse_depth + 1); } 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_PROP: 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: #if defined SUPPORT_UTF || !defined COMPILE_PCRE8 case OP_XCLASS: #endif return SSB_FAIL; /* 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 have to ensure it is set as not whitespace. Luckily, the code value is the same (0x0b) in ASCII and EBCDIC, so we can just adjust the appropriate bit. */ case OP_NOT_WHITESPACE: set_nottype_bits(start_bits, cbit_space, table_limit, cd); start_bits[1] |= 0x08; try_next = FALSE; break; /* The cbit_space table has vertical tab as whitespace; we have to not set it from the table. Luckily, the code value is the same (0x0b) in ASCII and EBCDIC, so we can just adjust the appropriate bit. */ case OP_WHITESPACE: c = start_bits[1]; /* Save in case it was already set */ set_type_bits(start_bits, cbit_space, table_limit, cd); start_bits[1] = (start_bits[1] & ~0x08) | c; 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. */ 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; tcode++; map = (pcre_uint8 *)tcode; /* 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 (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. */ tcode += 32 / sizeof(pcre_uchar); 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; 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, 0)) { 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 */