/************************************************* * 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 Copyright (c) 1998 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. ----------------------------------------------------------------------------- */ /* Define DEBUG to get debugging output on stdout. */ /* #define DEBUG */ /* Use a macro for debugging printing, 'cause that eliminates the use of #ifdef inline, and there are *still* stupid compilers about that don't like indented pre-processor statements. I suppose it's only been 10 years... */ #ifdef DEBUG #define DPRINTF(p) printf p #else #define DPRINTF(p) /*nothing*/ #endif /* Include the internals header, which itself includes Standard C headers plus the external pcre header. */ #include "internal.h" /* Allow compilation as C++ source code, should anybody want to do that. */ #ifdef __cplusplus #define class pcre_class #endif /* Number of items on the nested bracket stacks at compile time. This should not be set greater than 200. */ #define BRASTACK_SIZE 200 /* Min and max values for the common repeats; for the maxima, 0 => infinity */ static const char rep_min[] = { 0, 0, 1, 1, 0, 0 }; static const char rep_max[] = { 0, 0, 0, 0, 1, 1 }; /* Text forms of OP_ values and things, for debugging (not all used) */ #ifdef DEBUG static const char *OP_names[] = { "End", "\\A", "\\B", "\\b", "\\D", "\\d", "\\S", "\\s", "\\W", "\\w", "\\Z", "\\z", "Opt", "^", "$", "Any", "chars", "not", "*", "*?", "+", "+?", "?", "??", "{", "{", "{", "*", "*?", "+", "+?", "?", "??", "{", "{", "{", "*", "*?", "+", "+?", "?", "??", "{", "{", "{", "*", "*?", "+", "+?", "?", "??", "{", "{", "class", "Ref", "Alt", "Ket", "KetRmax", "KetRmin", "Assert", "Assert not", "AssertB", "AssertB not", "Reverse", "Once", "Cond", "Cref", "Brazero", "Braminzero", "Bra" }; #endif /* Table for handling escaped characters in the range '0'-'z'. Positive returns are simple data values; negative values are for special things like \d and so on. Zero means further processing is needed (for things like \x), or the escape is invalid. */ static const short int escapes[] = { 0, 0, 0, 0, 0, 0, 0, 0, /* 0 - 7 */ 0, 0, ':', ';', '<', '=', '>', '?', /* 8 - ? */ '@', -ESC_A, -ESC_B, 0, -ESC_D, 0, 0, 0, /* @ - G */ 0, 0, 0, 0, 0, 0, 0, 0, /* H - O */ 0, 0, 0, -ESC_S, 0, 0, 0, -ESC_W, /* P - W */ 0, 0, -ESC_Z, '[', '\\', ']', '^', '_', /* X - _ */ '`', 7, -ESC_b, 0, -ESC_d, 27, '\f', 0, /* ` - g */ 0, 0, 0, 0, 0, 0, '\n', 0, /* h - o */ 0, 0, '\r', -ESC_s, '\t', 0, 0, -ESC_w, /* p - w */ 0, 0, -ESC_z /* x - z */ }; /* Definition to allow mutual recursion */ static BOOL compile_regex(int, int, int *, uschar **, const uschar **, const char **, BOOL, int); /* Structure for passing "static" information around between the functions doing the matching, so that they are thread-safe. */ typedef struct match_data { int errorcode; /* As it says */ int *offset_vector; /* Offset vector */ int offset_end; /* One past the end */ int offset_max; /* The maximum usable for return data */ BOOL offset_overflow; /* Set if too many extractions */ BOOL notbol; /* NOTBOL flag */ BOOL noteol; /* NOTEOL flag */ BOOL endonly; /* Dollar not before final \n */ const uschar *start_subject; /* Start of the subject string */ const uschar *end_subject; /* End of the subject string */ const uschar *end_match_ptr; /* Subject position at end match */ int end_offset_top; /* Highwater mark at end of match */ } match_data; /************************************************* * Global variables * *************************************************/ /* PCRE is thread-clean and doesn't use any global variables in the normal sense. However, it calls memory allocation and free functions via the two indirections below, which are can be changed by the caller, but are shared between all threads. */ void *(*pcre_malloc)(size_t) = malloc; void (*pcre_free)(void *) = free; /************************************************* * Return version string * *************************************************/ const char * pcre_version(void) { return PCRE_VERSION; } /************************************************* * Return info about a compiled pattern * *************************************************/ /* This function picks potentially useful data out of the private structure. Arguments: external_re points to compiled code optptr where to pass back the options first_char where to pass back the first character, or -1 if multiline and all branches start ^, or -2 otherwise Returns: number of identifying extraction brackets or negative values on error */ int pcre_info(const pcre *external_re, int *optptr, int *first_char) { const real_pcre *re = (const real_pcre *)external_re; if (re == NULL) return PCRE_ERROR_NULL; if (re->magic_number != MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC; if (optptr != NULL) *optptr = (re->options & PUBLIC_OPTIONS); if (first_char != NULL) *first_char = ((re->options & PCRE_FIRSTSET) != 0)? re->first_char : ((re->options & PCRE_STARTLINE) != 0)? -1 : -2; return re->top_bracket; } #ifdef DEBUG /************************************************* * Debugging function to print chars * *************************************************/ /* Print a sequence of chars in printable format, stopping at the end of the subject if the requested. Arguments: p points to characters length number to print is_subject TRUE if printing from within md->start_subject md pointer to matching data block, if is_subject is TRUE Returns: nothing */ static void pchars(const uschar *p, int length, BOOL is_subject, match_data *md) { int c; if (is_subject && length > md->end_subject - p) length = md->end_subject - p; while (length-- > 0) if (isprint(c = *(p++))) printf("%c", c); else printf("\\x%02x", c); } #endif /************************************************* * Handle escapes * *************************************************/ /* This function is called when a \ has been encountered. It either returns a positive value for a simple escape such as \n, or a negative value which encodes one of the more complicated things such as \d. On entry, ptr is pointing at the \. On exit, it is on the final character of the escape sequence. Arguments: ptrptr points to the pattern position pointer errorptr points to the pointer to the error message bracount number of previous extracting brackets options the options bits isclass TRUE if inside a character class Returns: zero or positive => a data character negative => a special escape sequence on error, errorptr is set */ static int check_escape(const uschar **ptrptr, const char **errorptr, int bracount, int options, BOOL isclass) { const uschar *ptr = *ptrptr; int c = *(++ptr) & 255; /* Ensure > 0 on signed-char systems */ int i; if (c == 0) *errorptr = ERR1; /* Digits or letters may have special meaning; all others are literals. */ else if (c < '0' || c > 'z') {} /* Do an initial lookup in a table. A non-zero result is something that can be returned immediately. Otherwise further processing may be required. */ else if ((i = escapes[c - '0']) != 0) c = i; /* Escapes that need further processing, or are illegal. */ else { const uschar *oldptr; switch (c) { /* The handling of escape sequences consisting of a string of digits starting with one that is not zero is not straightforward. By experiment, the way Perl works seems to be as follows: Outside a character class, the digits are read as a decimal number. If the number is less than 10, or if there are that many previous extracting left brackets, then it is a back reference. Otherwise, up to three octal digits are read to form an escaped byte. Thus \123 is likely to be octal 123 (cf \0123, which is octal 012 followed by the literal 3). If the octal value is greater than 377, the least significant 8 bits are taken. Inside a character class, \ followed by a digit is always an octal number. */ case '1': case '2': case '3': case '4': case '5': case '6': case '7': case '8': case '9': if (!isclass) { oldptr = ptr; c -= '0'; while ((pcre_ctypes[ptr[1]] & ctype_digit) != 0) c = c * 10 + *(++ptr) - '0'; if (c < 10 || c <= bracount) { c = -(ESC_REF + c); break; } ptr = oldptr; /* Put the pointer back and fall through */ } /* Handle an octal number following \. If the first digit is 8 or 9, Perl generates a binary zero byte and treats the digit as a following literal. Thus we have to pull back the pointer by one. */ if ((c = *ptr) >= '8') { ptr--; c = 0; break; } /* \0 always starts an octal number, but we may drop through to here with a larger first octal digit */ case '0': c -= '0'; while(i++ < 2 && (pcre_ctypes[ptr[1]] & ctype_digit) != 0 && ptr[1] != '8' && ptr[1] != '9') c = c * 8 + *(++ptr) - '0'; break; /* Special escapes not starting with a digit are straightforward */ case 'x': c = 0; while (i++ < 2 && (pcre_ctypes[ptr[1]] & ctype_xdigit) != 0) { ptr++; c = c * 16 + pcre_lcc[*ptr] - (((pcre_ctypes[*ptr] & ctype_digit) != 0)? '0' : 'W'); } break; case 'c': c = *(++ptr); if (c == 0) { *errorptr = ERR2; return 0; } /* A letter is upper-cased; then the 0x40 bit is flipped */ if (c >= 'a' && c <= 'z') c = pcre_fcc[c]; c ^= 0x40; break; /* PCRE_EXTRA enables extensions to Perl in the matter of escapes. Any other alphameric following \ is an error if PCRE_EXTRA was set; otherwise, for Perl compatibility, it is a literal. */ default: if ((options & PCRE_EXTRA) != 0) switch(c) { default: *errorptr = ERR3; break; } break; } } *ptrptr = ptr; return c; } /************************************************* * Check for counted repeat * *************************************************/ /* This function is called when a '{' is encountered in a place where it might start a quantifier. It looks ahead to see if it really is a quantifier or not. It is only a quantifier if it is one of the forms {ddd} {ddd,} or {ddd,ddd} where the ddds are digits. Arguments: p pointer to the first char after '{' Returns: TRUE or FALSE */ static BOOL is_counted_repeat(const uschar *p) { if ((pcre_ctypes[*p++] & ctype_digit) == 0) return FALSE; while ((pcre_ctypes[*p] & ctype_digit) != 0) p++; if (*p == '}') return TRUE; if (*p++ != ',') return FALSE; if (*p == '}') return TRUE; if ((pcre_ctypes[*p++] & ctype_digit) == 0) return FALSE; while ((pcre_ctypes[*p] & ctype_digit) != 0) p++; return (*p == '}'); } /************************************************* * Read repeat counts * *************************************************/ /* Read an item of the form {n,m} and return the values. This is called only after is_counted_repeat() has confirmed that a repeat-count quantifier exists, so the syntax is guaranteed to be correct, but we need to check the values. Arguments: p pointer to first char after '{' minp pointer to int for min maxp pointer to int for max returned as -1 if no max errorptr points to pointer to error message Returns: pointer to '}' on success; current ptr on error, with errorptr set */ static const uschar * read_repeat_counts(const uschar *p, int *minp, int *maxp, const char **errorptr) { int min = 0; int max = -1; while ((pcre_ctypes[*p] & ctype_digit) != 0) min = min * 10 + *p++ - '0'; if (*p == '}') max = min; else { if (*(++p) != '}') { max = 0; while((pcre_ctypes[*p] & ctype_digit) != 0) max = max * 10 + *p++ - '0'; if (max < min) { *errorptr = ERR4; return p; } } } /* Do paranoid checks, then fill in the required variables, and pass back the pointer to the terminating '}'. */ if (min > 65535 || max > 65535) *errorptr = ERR5; else { *minp = min; *maxp = max; } return p; } /************************************************* * Find the fixed length of a pattern * *************************************************/ /* Scan a pattern and compute the fixed length of subject that will match it, if the length is fixed. This is needed for dealing with backward assertions. Arguments: code points to the start of the pattern (the bracket) Returns: the fixed length, or -1 if there is no fixed length */ static int find_fixedlength(uschar *code) { int length = -1; register int branchlength = 0; register uschar *cc = code + 3; /* 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; register int op = *cc; if (op >= OP_BRA) op = OP_BRA; switch (op) { case OP_BRA: case OP_ONCE: case OP_COND: d = find_fixedlength(cc); if (d < 0) return -1; branchlength += d; do cc += (cc[1] << 8) + cc[2]; while (*cc == OP_ALT); cc += 3; break; /* 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. */ case OP_ALT: case OP_KET: case OP_KETRMAX: case OP_KETRMIN: case OP_END: if (length < 0) length = branchlength; else if (length != branchlength) return -1; if (*cc != OP_ALT) return length; cc += 3; branchlength = 0; break; /* Skip over assertive subpatterns */ case OP_ASSERT: case OP_ASSERT_NOT: case OP_ASSERTBACK: case OP_ASSERTBACK_NOT: do cc += (cc[1] << 8) + cc[2]; while (*cc == OP_ALT); cc += 3; break; /* Skip over things that don't match chars */ case OP_REVERSE: cc++; case OP_CREF: case OP_OPT: cc++; /* Fall through */ case OP_SOD: case OP_EOD: case OP_EODN: case OP_CIRC: case OP_DOLL: case OP_NOT_WORD_BOUNDARY: case OP_WORD_BOUNDARY: cc++; break; /* Handle char strings */ case OP_CHARS: branchlength += *(++cc); cc += *cc + 1; break; /* Handle exact repetitions */ case OP_EXACT: case OP_TYPEEXACT: branchlength += (cc[1] << 8) + cc[2]; cc += 4; break; /* Handle single-char matchers */ case OP_NOT_DIGIT: case OP_DIGIT: case OP_NOT_WHITESPACE: case OP_WHITESPACE: case OP_NOT_WORDCHAR: case OP_WORDCHAR: case OP_ANY: branchlength++; cc++; break; /* Check a class for variable quantification */ case OP_CLASS: cc += (*cc == OP_REF)? 2 : 33; switch (*cc) { case OP_CRSTAR: case OP_CRMINSTAR: case OP_CRQUERY: case OP_CRMINQUERY: return -1; case OP_CRRANGE: case OP_CRMINRANGE: if ((cc[1] << 8) + cc[2] != (cc[3] << 8) + cc[4]) return -1; branchlength += (cc[1] << 8) + cc[2]; cc += 5; break; default: branchlength++; } break; /* Anything else is variable length */ default: return -1; } } /* Control never gets here */ } /************************************************* * Compile one branch * *************************************************/ /* Scan the pattern, compiling it into the code vector. Arguments: options the option bits brackets points to number of brackets used code points to the pointer to the current code point ptrptr points to the current pattern pointer errorptr points to pointer to error message optchanged set to the value of the last OP_OPT item compiled Returns: TRUE on success FALSE, with *errorptr set on error */ static BOOL compile_branch(int options, int *brackets, uschar **codeptr, const uschar **ptrptr, const char **errorptr, int *optchanged) { int repeat_type, op_type; int repeat_min, repeat_max; int bravalue, length; int greedy_default, greedy_non_default; register int c; register uschar *code = *codeptr; uschar *tempcode; const uschar *ptr = *ptrptr; const uschar *tempptr; uschar *previous = NULL; uschar class[32]; /* Set up the default and non-default settings for greediness */ greedy_default = ((options & PCRE_UNGREEDY) != 0); greedy_non_default = greedy_default ^ 1; /* Switch on next character until the end of the branch */ for (;; ptr++) { BOOL negate_class; int class_charcount; int class_lastchar; int newoptions; int condref; c = *ptr; if ((options & PCRE_EXTENDED) != 0) { if ((pcre_ctypes[c] & ctype_space) != 0) continue; if (c == '#') { while ((c = *(++ptr)) != 0 && c != '\n'); continue; } } switch(c) { /* The branch terminates at end of string, |, or ). */ case 0: case '|': case ')': *codeptr = code; *ptrptr = ptr; return TRUE; /* Handle single-character metacharacters */ case '^': previous = NULL; *code++ = OP_CIRC; break; case '$': previous = NULL; *code++ = OP_DOLL; break; case '.': previous = code; *code++ = OP_ANY; break; /* Character classes. These always build a 32-byte bitmap of the permitted characters, except in the special case where there is only one character. For negated classes, we build the map as usual, then invert it at the end. */ case '[': previous = code; *code++ = OP_CLASS; /* If the first character is '^', set the negation flag and skip it. */ if ((c = *(++ptr)) == '^') { negate_class = TRUE; c = *(++ptr); } else negate_class = FALSE; /* Keep a count of chars so that we can optimize the case of just a single character. */ class_charcount = 0; class_lastchar = -1; /* Initialize the 32-char bit map to all zeros. We have to build the map in a temporary bit of store, in case the class contains only 1 character, because in that case the compiled code doesn't use the bit map. */ memset(class, 0, 32 * sizeof(uschar)); /* Process characters until ] is reached. By writing this as a "do" it means that an initial ] is taken as a data character. */ do { if (c == 0) { *errorptr = ERR6; goto FAILED; } /* Backslash may introduce a single character, or it may introduce one of the specials, which just set a flag. Escaped items are checked for validity in the pre-compiling pass. The sequence \b is a special case. Inside a class (and only there) it is treated as backspace. Elsewhere it marks a word boundary. Other escapes have preset maps ready to or into the one we are building. We assume they have more than one character in them, so set class_count bigger than one. */ if (c == '\\') { c = check_escape(&ptr, errorptr, *brackets, options, TRUE); if (-c == ESC_b) c = '\b'; else if (c < 0) { class_charcount = 10; switch (-c) { case ESC_d: for (c = 0; c < 32; c++) class[c] |= pcre_cbits[c+cbit_digit]; continue; case ESC_D: for (c = 0; c < 32; c++) class[c] |= ~pcre_cbits[c+cbit_digit]; continue; case ESC_w: for (c = 0; c < 32; c++) class[c] |= (pcre_cbits[c] | pcre_cbits[c+cbit_word]); continue; case ESC_W: for (c = 0; c < 32; c++) class[c] |= ~(pcre_cbits[c] | pcre_cbits[c+cbit_word]); continue; case ESC_s: for (c = 0; c < 32; c++) class[c] |= pcre_cbits[c+cbit_space]; continue; case ESC_S: for (c = 0; c < 32; c++) class[c] |= ~pcre_cbits[c+cbit_space]; continue; default: *errorptr = ERR7; goto FAILED; } } /* Fall through if single character */ } /* A single character may be followed by '-' to form a range. However, Perl does not permit ']' to be the end of the range. A '-' character here is treated as a literal. */ if (ptr[1] == '-' && ptr[2] != ']') { int d; ptr += 2; d = *ptr; if (d == 0) { *errorptr = ERR6; goto FAILED; } /* The second part of a range can be a single-character escape, but not any of the other escapes. */ if (d == '\\') { d = check_escape(&ptr, errorptr, *brackets, options, TRUE); if (d < 0) { if (d == -ESC_b) d = '\b'; else { *errorptr = ERR7; goto FAILED; } } } if (d < c) { *errorptr = ERR8; goto FAILED; } for (; c <= d; c++) { class[c/8] |= (1 << (c&7)); if ((options & PCRE_CASELESS) != 0) { int uc = pcre_fcc[c]; /* flip case */ class[uc/8] |= (1 << (uc&7)); } class_charcount++; /* in case a one-char range */ class_lastchar = c; } continue; /* Go get the next char in the class */ } /* Handle a lone single character - we can get here for a normal non-escape char, or after \ that introduces a single character. */ class [c/8] |= (1 << (c&7)); if ((options & PCRE_CASELESS) != 0) { c = pcre_fcc[c]; /* flip case */ class[c/8] |= (1 << (c&7)); } class_charcount++; class_lastchar = c; } /* Loop until ']' reached; the check for end of string happens inside the loop. This "while" is the end of the "do" above. */ while ((c = *(++ptr)) != ']'); /* If class_charcount is 1 and class_lastchar is not negative, we saw precisely one character. This doesn't need the whole 32-byte bit map. We turn it into a 1-character OP_CHAR if it's positive, or OP_NOT if it's negative. */ if (class_charcount == 1 && class_lastchar >= 0) { if (negate_class) { code[-1] = OP_NOT; } else { code[-1] = OP_CHARS; *code++ = 1; } *code++ = class_lastchar; } /* Otherwise, negate the 32-byte map if necessary, and copy it into the code vector. */ else { if (negate_class) for (c = 0; c < 32; c++) code[c] = ~class[c]; else memcpy(code, class, 32); code += 32; } break; /* Various kinds of repeat */ case '{': if (!is_counted_repeat(ptr+1)) goto NORMAL_CHAR; ptr = read_repeat_counts(ptr+1, &repeat_min, &repeat_max, errorptr); if (*errorptr != NULL) goto FAILED; goto REPEAT; case '*': repeat_min = 0; repeat_max = -1; goto REPEAT; case '+': repeat_min = 1; repeat_max = -1; goto REPEAT; case '?': repeat_min = 0; repeat_max = 1; REPEAT: if (previous == NULL) { *errorptr = ERR9; goto FAILED; } /* If the next character is '?' this is a minimizing repeat, by default, but if PCRE_UNGREEDY is set, it works the other way round. Advance to the next character. */ if (ptr[1] == '?') { repeat_type = greedy_non_default; ptr++; } else repeat_type = greedy_default; /* If the maximum is zero then the minimum must also be zero; Perl allows this case, so we do too - by simply omitting the item altogether. */ if (repeat_max == 0) code = previous; /* If previous was a string of characters, chop off the last one and use it as the subject of the repeat. If there was only one character, we can abolish the previous item altogether. */ else if (*previous == OP_CHARS) { int len = previous[1]; if (len == 1) { c = previous[2]; code = previous; } else { c = previous[len+1]; previous[1]--; code--; } op_type = 0; /* Use single-char op codes */ goto OUTPUT_SINGLE_REPEAT; /* Code shared with single character types */ } /* If previous was a single negated character ([^a] or similar), we use one of the special opcodes, replacing it. The code is shared with single- character repeats by adding a suitable offset into repeat_type. */ else if ((int)*previous == OP_NOT) { op_type = OP_NOTSTAR - OP_STAR; /* Use "not" opcodes */ c = previous[1]; code = previous; goto OUTPUT_SINGLE_REPEAT; } /* If previous was a character type match (\d or similar), abolish it and create a suitable repeat item. The code is shared with single-character repeats by adding a suitable offset into repeat_type. */ else if ((int)*previous < OP_EODN || *previous == OP_ANY) { op_type = OP_TYPESTAR - OP_STAR; /* Use type opcodes */ c = *previous; code = previous; OUTPUT_SINGLE_REPEAT: repeat_type += op_type; /* Combine both values for many cases */ /* A minimum of zero is handled either as the special case * or ?, or as an UPTO, with the maximum given. */ if (repeat_min == 0) { if (repeat_max == -1) *code++ = OP_STAR + repeat_type; else if (repeat_max == 1) *code++ = OP_QUERY + repeat_type; else { *code++ = OP_UPTO + repeat_type; *code++ = repeat_max >> 8; *code++ = (repeat_max & 255); } } /* The case {1,} is handled as the special case + */ else if (repeat_min == 1 && repeat_max == -1) *code++ = OP_PLUS + repeat_type; /* The case {n,n} is just an EXACT, while the general case {n,m} is handled as an EXACT followed by an UPTO. An EXACT of 1 is optimized. */ else { if (repeat_min != 1) { *code++ = OP_EXACT + op_type; /* NB EXACT doesn't have repeat_type */ *code++ = repeat_min >> 8; *code++ = (repeat_min & 255); } /* If the mininum is 1 and the previous item was a character string, we either have to put back the item that got cancelled if the string length was 1, or add the character back onto the end of a longer string. For a character type nothing need be done; it will just get put back naturally. Note that the final character is always going to get added below. */ else if (*previous == OP_CHARS) { if (code == previous) code += 2; else previous[1]++; } /* For a single negated character we also have to put back the item that got cancelled. */ else if (*previous == OP_NOT) code++; /* If the maximum is unlimited, insert an OP_STAR. */ if (repeat_max < 0) { *code++ = c; *code++ = OP_STAR + repeat_type; } /* Else insert an UPTO if the max is greater than the min. */ else if (repeat_max != repeat_min) { *code++ = c; repeat_max -= repeat_min; *code++ = OP_UPTO + repeat_type; *code++ = repeat_max >> 8; *code++ = (repeat_max & 255); } } /* The character or character type itself comes last in all cases. */ *code++ = c; } /* If previous was a character class or a back reference, we put the repeat stuff after it. */ else if (*previous == OP_CLASS || *previous == OP_REF) { if (repeat_min == 0 && repeat_max == -1) *code++ = OP_CRSTAR + repeat_type; else if (repeat_min == 1 && repeat_max == -1) *code++ = OP_CRPLUS + repeat_type; else if (repeat_min == 0 && repeat_max == 1) *code++ = OP_CRQUERY + repeat_type; else { *code++ = OP_CRRANGE + repeat_type; *code++ = repeat_min >> 8; *code++ = repeat_min & 255; if (repeat_max == -1) repeat_max = 0; /* 2-byte encoding for max */ *code++ = repeat_max >> 8; *code++ = repeat_max & 255; } } /* If previous was a bracket group, we may have to replicate it in certain cases. */ else if ((int)*previous >= OP_BRA || (int)*previous == OP_ONCE || (int)*previous == OP_COND) { int i, ketoffset = 0; int len = code - previous; /* If the maximum repeat count is unlimited, find the end of the bracket by scanning through from the start, and compute the offset back to it from the current code pointer. There may be an OP_OPT setting following the final KET, so we can't find the end just by going back from the code pointer. */ if (repeat_max == -1) { register uschar *ket = previous; do ket += (ket[1] << 8) + ket[2]; while (*ket != OP_KET); ketoffset = code - ket; } /* If the minimum is greater than zero, and the maximum is unlimited or equal to the minimum, the first copy remains where it is, and is replicated up to the minimum number of times. This case includes the + repeat, but of course no replication is needed in that case. */ if (repeat_min > 0 && (repeat_max == -1 || repeat_max == repeat_min)) { for (i = 1; i < repeat_min; i++) { memcpy(code, previous, len); code += len; } } /* If the minimum is zero, stick BRAZERO in front of the first copy. Then, if there is a fixed upper limit, replicated up to that many times, sticking BRAZERO in front of all the optional ones. */ else { if (repeat_min == 0) { memmove(previous+1, previous, len); code++; *previous++ = OP_BRAZERO + repeat_type; } for (i = 1; i < repeat_min; i++) { memcpy(code, previous, len); code += len; } for (i = (repeat_min > 0)? repeat_min : 1; i < repeat_max; i++) { *code++ = OP_BRAZERO + repeat_type; memcpy(code, previous, len); code += len; } } /* If the maximum is unlimited, set a repeater in the final copy. We can't just offset backwards from the current code point, because we don't know if there's been an options resetting after the ket. The correct offset was computed above. */ if (repeat_max == -1) code[-ketoffset] = OP_KETRMAX + repeat_type; } /* Else there's some kind of shambles */ else { *errorptr = ERR11; goto FAILED; } /* In all case we no longer have a previous item. */ previous = NULL; break; /* Start of nested bracket sub-expression, or comment or lookahead or lookbehind or option setting or condition. First deal with special things that can come after a bracket; all are introduced by ?, and the appearance of any of them means that this is not a referencing group. They were checked for validity in the first pass over the string, so we don't have to check for syntax errors here. */ case '(': newoptions = options; condref = -1; if (*(++ptr) == '?') { int set, unset; int *optset; switch (*(++ptr)) { case '#': /* Comment; skip to ket */ ptr++; while (*ptr != ')') ptr++; continue; case ':': /* Non-extracting bracket */ bravalue = OP_BRA; ptr++; break; case '(': bravalue = OP_COND; /* Conditional group */ if ((pcre_ctypes[*(++ptr)] & ctype_digit) != 0) { condref = *ptr - '0'; while (*(++ptr) != ')') condref = condref*10 + *ptr - '0'; ptr++; } else ptr--; break; case '=': /* Positive lookahead */ bravalue = OP_ASSERT; ptr++; break; case '!': /* Negative lookahead */ bravalue = OP_ASSERT_NOT; ptr++; break; case '<': /* Lookbehinds */ switch (*(++ptr)) { case '=': /* Positive lookbehind */ bravalue = OP_ASSERTBACK; ptr++; break; case '!': /* Negative lookbehind */ bravalue = OP_ASSERTBACK_NOT; ptr++; break; default: /* Syntax error */ *errorptr = ERR24; goto FAILED; } break; case '>': /* One-time brackets */ bravalue = OP_ONCE; ptr++; break; default: /* Option setting */ set = unset = 0; optset = &set; while (*ptr != ')' && *ptr != ':') { switch (*ptr++) { case '-': optset = &unset; break; case 'i': *optset |= PCRE_CASELESS; break; case 'm': *optset |= PCRE_MULTILINE; break; case 's': *optset |= PCRE_DOTALL; break; case 'x': *optset |= PCRE_EXTENDED; break; case 'U': *optset |= PCRE_UNGREEDY; break; case 'X': *optset |= PCRE_EXTRA; break; default: *errorptr = ERR12; goto FAILED; } } /* Set up the changed option bits, but don't change anything yet. */ newoptions = (options | set) & (~unset); /* If the options ended with ')' this is not the start of a nested group with option changes, so the options change at this level. At top level there is nothing else to be done (the options will in fact have been set from the start of compiling as a result of the first pass) but at an inner level we must compile code to change the ims options if necessary, and pass the new setting back so that it can be put at the start of any following branches, and when this group ends, a resetting item can be compiled. */ if (*ptr == ')') { if ((options & PCRE_INGROUP) != 0 && (options & PCRE_IMS) != (newoptions & PCRE_IMS)) { *code++ = OP_OPT; *code++ = *optchanged = newoptions & PCRE_IMS; } options = newoptions; /* Change options at this level */ previous = NULL; /* This item can't be repeated */ continue; /* It is complete */ } /* If the options ended with ':' we are heading into a nested group with possible change of options. Such groups are non-capturing and are not assertions of any kind. All we need to do is skip over the ':'; the newoptions value is handled below. */ bravalue = OP_BRA; ptr++; } } /* Else we have a referencing group; adjust the opcode. */ else { if (++(*brackets) > EXTRACT_MAX) { *errorptr = ERR13; goto FAILED; } bravalue = OP_BRA + *brackets; } /* Process nested bracketed re. Assertions may not be repeated, but other kinds can be. We copy code into a non-register variable in order to be able to pass its address because some compilers complain otherwise. Pass in a new setting for the ims options if they have changed. */ previous = (bravalue >= OP_ONCE)? code : NULL; *code = bravalue; tempcode = code; if (!compile_regex( options | PCRE_INGROUP, /* Set for all nested groups */ ((options & PCRE_IMS) != (newoptions & PCRE_IMS))? newoptions & PCRE_IMS : -1, /* Pass ims options if changed */ brackets, /* Bracket level */ &tempcode, /* Where to put code (updated) */ &ptr, /* Input pointer (updated) */ errorptr, /* Where to put an error message */ (bravalue == OP_ASSERTBACK || bravalue == OP_ASSERTBACK_NOT), /* TRUE if back assert */ condref)) /* Condition reference number */ goto FAILED; /* At the end of compiling, code is still pointing to the start of the group, while tempcode has been updated to point past the end of the group and any option resetting that may follow it. The pattern pointer (ptr) is on the bracket. */ /* If this is a conditional bracket, check that there are no more than two branches in the group. */ if (bravalue == OP_COND) { int branchcount = 0; uschar *tc = code; do { branchcount++; tc += (tc[1] << 8) | tc[2]; } while (*tc != OP_KET); if (branchcount > 2) { *errorptr = ERR27; goto FAILED; } } /* Now update the main code pointer to the end of the group. */ code = tempcode; /* Error if hit end of pattern */ if (*ptr != ')') { *errorptr = ERR14; goto FAILED; } break; /* Check \ for being a real metacharacter; if not, fall through and handle it as a data character at the start of a string. Escape items are checked for validity in the pre-compiling pass. */ case '\\': tempptr = ptr; c = check_escape(&ptr, errorptr, *brackets, options, FALSE); /* Handle metacharacters introduced by \. For ones like \d, the ESC_ values are arranged to be the negation of the corresponding OP_values. For the back references, the values are ESC_REF plus the reference number. Only back references and those types that consume a character may be repeated. We can test for values between ESC_b and ESC_Z for the latter; this may have to change if any new ones are ever created. */ if (c < 0) { if (-c >= ESC_REF) { previous = code; *code++ = OP_REF; *code++ = -c - ESC_REF; } else { previous = (-c > ESC_b && -c < ESC_Z)? code : NULL; *code++ = -c; } continue; } /* Data character: reset and fall through */ ptr = tempptr; c = '\\'; /* Handle a run of data characters until a metacharacter is encountered. The first character is guaranteed not to be whitespace or # when the extended flag is set. */ NORMAL_CHAR: default: previous = code; *code = OP_CHARS; code += 2; length = 0; do { if ((options & PCRE_EXTENDED) != 0) { if ((pcre_ctypes[c] & ctype_space) != 0) continue; if (c == '#') { while ((c = *(++ptr)) != 0 && c != '\n'); if (c == 0) break; continue; } } /* Backslash may introduce a data char or a metacharacter. Escaped items are checked for validity in the pre-compiling pass. Stop the string before a metaitem. */ if (c == '\\') { tempptr = ptr; c = check_escape(&ptr, errorptr, *brackets, options, FALSE); if (c < 0) { ptr = tempptr; break; } } /* Ordinary character or single-char escape */ *code++ = c; length++; } /* This "while" is the end of the "do" above. */ while (length < 255 && (pcre_ctypes[c = *(++ptr)] & ctype_meta) == 0); /* Compute the length and set it in the data vector, and advance to the next state. */ previous[1] = length; if (length < 255) ptr--; break; } } /* end of big loop */ /* Control never reaches here by falling through, only by a goto for all the error states. Pass back the position in the pattern so that it can be displayed to the user for diagnosing the error. */ FAILED: *ptrptr = ptr; return FALSE; } /************************************************* * Compile sequence of alternatives * *************************************************/ /* On entry, ptr is pointing past the bracket character, but on return it points to the closing bracket, or vertical bar, or end of string. The code variable is pointing at the byte into which the BRA operator has been stored. If the ims options are changed at the start (for a (?ims: group) or during any branch, we need to insert an OP_OPT item at the start of every following branch to ensure they get set correctly at run time, and also pass the new options into every subsequent branch compile. Argument: options the option bits optchanged new ims options to set as if (?ims) were at the start, or -1 for no change brackets -> int containing the number of extracting brackets used codeptr -> the address of the current code pointer ptrptr -> the address of the current pattern pointer errorptr -> pointer to error message lookbehind TRUE if this is a lookbehind assertion condref > 0 for OPT_CREF setting at start of conditional group Returns: TRUE on success */ static BOOL compile_regex(int options, int optchanged, int *brackets, uschar **codeptr, const uschar **ptrptr, const char **errorptr, BOOL lookbehind, int condref) { const uschar *ptr = *ptrptr; uschar *code = *codeptr; uschar *last_branch = code; uschar *start_bracket = code; uschar *reverse_count = NULL; int oldoptions = options & PCRE_IMS; code += 3; /* At the start of a reference-based conditional group, insert the reference number as an OP_CREF item. */ if (condref > 0) { *code++ = OP_CREF; *code++ = condref; } /* Loop for each alternative branch */ for (;;) { int length; /* Handle change of options */ if (optchanged >= 0) { *code++ = OP_OPT; *code++ = optchanged; options = (options & ~PCRE_IMS) | optchanged; } /* Set up dummy OP_REVERSE if lookbehind assertion */ if (lookbehind) { *code++ = OP_REVERSE; reverse_count = code; *code++ = 0; *code++ = 0; } /* Now compile the branch */ if (!compile_branch(options, brackets, &code, &ptr, errorptr, &optchanged)) { *ptrptr = ptr; return FALSE; } /* Fill in the length of the last branch */ length = code - last_branch; last_branch[1] = length >> 8; last_branch[2] = length & 255; /* If lookbehind, check that this branch matches a fixed-length string, and put the length into the OP_REVERSE item. Temporarily mark the end of the branch with OP_END. */ if (lookbehind) { *code = OP_END; length = find_fixedlength(last_branch); DPRINTF(("fixed length = %d\n", length)); if (length < 0) { *errorptr = ERR25; *ptrptr = ptr; return FALSE; } reverse_count[0] = (length >> 8); reverse_count[1] = length & 255; } /* Reached end of expression, either ')' or end of pattern. Insert a terminating ket and the length of the whole bracketed item, and return, leaving the pointer at the terminating char. If any of the ims options were changed inside the group, compile a resetting op-code following. */ if (*ptr != '|') { length = code - start_bracket; *code++ = OP_KET; *code++ = length >> 8; *code++ = length & 255; if (optchanged >= 0) { *code++ = OP_OPT; *code++ = oldoptions; } *codeptr = code; *ptrptr = ptr; return TRUE; } /* Another branch follows; insert an "or" node and advance the pointer. */ *code = OP_ALT; last_branch = code; code += 3; ptr++; } /* Control never reaches here */ } /************************************************* * Find first significant op code * *************************************************/ /* This is called by several functions that scan a compiled expression looking for a fixed first character, or an anchoring op code etc. It skips over things that do not influence this. For one application, a change of caseless option is important. Arguments: code pointer to the start of the group options pointer to external options optbit the option bit whose changing is significant, or zero if none are optstop TRUE to return on option change, otherwise change the options value and continue Returns: pointer to the first significant opcode */ static const uschar* first_significant_code(const uschar *code, int *options, int optbit, BOOL optstop) { for (;;) { switch ((int)*code) { case OP_OPT: if (optbit > 0 && ((int)code[1] & optbit) != (*options & optbit)) { if (optstop) return code; *options = (int)code[1]; } code += 2; break; case OP_CREF: code += 2; break; case OP_ASSERT_NOT: case OP_ASSERTBACK: case OP_ASSERTBACK_NOT: do code += (code[1] << 8) + code[2]; while (*code == OP_ALT); code += 3; break; default: return code; } } /* Control never reaches here */ } /************************************************* * Check for anchored expression * *************************************************/ /* Try to find out if this is an anchored regular expression. Consider each alternative branch. If they all start with OP_SOD or OP_CIRC, or with a bracket all of whose alternatives start with OP_SOD or OP_CIRC (recurse ad lib), then it's anchored. However, if this is a multiline pattern, then only OP_SOD counts, since OP_CIRC can match in the middle. A branch is also implicitly anchored if it starts with .* because that will try the rest of the pattern at all possible matching points, so there is no point trying them again. Arguments: code points to start of expression (the bracket) options points to the options setting Returns: TRUE or FALSE */ static BOOL is_anchored(register const uschar *code, int *options) { do { const uschar *scode = first_significant_code(code + 3, options, PCRE_MULTILINE, FALSE); register int op = *scode; if (op >= OP_BRA || op == OP_ASSERT || op == OP_ONCE || op == OP_COND) { if (!is_anchored(scode, options)) return FALSE; } else if (op == OP_TYPESTAR || op == OP_TYPEMINSTAR) { if (scode[1] != OP_ANY) return FALSE; } else if (op != OP_SOD && ((*options & PCRE_MULTILINE) != 0 || op != OP_CIRC)) return FALSE; code += (code[1] << 8) + code[2]; } while (*code == OP_ALT); return TRUE; } /************************************************* * Check for start with \n line expression * *************************************************/ /* This is called for multiline expressions to try to find out if every branch starts with ^ so that "first char" processing can be done to speed things up. Argument: points to start of expression (the bracket) Returns: TRUE or FALSE */ static BOOL is_startline(const uschar *code) { do { const uschar *scode = first_significant_code(code + 3, NULL, 0, FALSE); register int op = *scode; if (op >= OP_BRA || op == OP_ASSERT || op == OP_ONCE || op == OP_COND) { if (!is_startline(scode)) return FALSE; } else if (op != OP_CIRC) return FALSE; code += (code[1] << 8) + code[2]; } while (*code == OP_ALT); return TRUE; } /************************************************* * Check for fixed first char * *************************************************/ /* Try to find out if there is a fixed first character. This is called for unanchored expressions, as it speeds up their processing quite considerably. Consider each alternative branch. If they all start with the same char, or with a bracket all of whose alternatives start with the same char (recurse ad lib), then we return that char, otherwise -1. Arguments: code points to start of expression (the bracket) options pointer to the options (used to check casing changes) Returns: -1 or the fixed first char */ static int find_firstchar(const uschar *code, int *options) { register int c = -1; do { int d; const uschar *scode = first_significant_code(code + 3, options, PCRE_CASELESS, TRUE); register int op = *scode; if (op >= OP_BRA) op = OP_BRA; switch(op) { default: return -1; case OP_BRA: case OP_ASSERT: case OP_ONCE: case OP_COND: if ((d = find_firstchar(scode, options)) < 0) return -1; if (c < 0) c = d; else if (c != d) return -1; break; case OP_EXACT: /* Fall through */ scode++; case OP_CHARS: /* Fall through */ scode++; case OP_PLUS: case OP_MINPLUS: if (c < 0) c = scode[1]; else if (c != scode[1]) return -1; break; } code += (code[1] << 8) + code[2]; } while (*code == OP_ALT); return c; } /************************************************* * Compile a Regular Expression * *************************************************/ /* This function takes a string and returns a pointer to a block of store holding a compiled version of the expression. Arguments: pattern the regular expression options various option bits errorptr pointer to pointer to error text erroroffset ptr offset in pattern where error was detected Returns: pointer to compiled data block, or NULL on error, with errorptr and erroroffset set */ pcre * pcre_compile(const char *pattern, int options, const char **errorptr, int *erroroffset) { real_pcre *re; int length = 3; /* For initial BRA plus length */ int runlength; int c, size; int bracount = 0; int top_backref = 0; int branch_extra = 0; int branch_newextra; unsigned int brastackptr = 0; uschar *code; const uschar *ptr; int brastack[BRASTACK_SIZE]; uschar bralenstack[BRASTACK_SIZE]; #ifdef DEBUG uschar *code_base, *code_end; #endif /* We can't pass back an error message if errorptr is NULL; I guess the best we can do is just return NULL. */ if (errorptr == NULL) return NULL; *errorptr = NULL; /* However, we can give a message for this error */ if (erroroffset == NULL) { *errorptr = ERR16; return NULL; } *erroroffset = 0; if ((options & ~PUBLIC_OPTIONS) != 0) { *errorptr = ERR17; return NULL; } DPRINTF(("------------------------------------------------------------------\n")); DPRINTF(("%s\n", pattern)); /* The first thing to do is to make a pass over the pattern to compute the amount of store required to hold the compiled code. This does not have to be perfect as long as errors are overestimates. At the same time we can detect any internal flag settings. Make an attempt to correct for any counted white space if an "extended" flag setting appears late in the pattern. We can't be so clever for #-comments. */ ptr = (const uschar *)(pattern - 1); while ((c = *(++ptr)) != 0) { int min, max; int class_charcount; if ((options & PCRE_EXTENDED) != 0) { if ((pcre_ctypes[c] & ctype_space) != 0) continue; if (c == '#') { while ((c = *(++ptr)) != 0 && c != '\n'); continue; } } switch(c) { /* A backslashed item may be an escaped "normal" character or a character type. For a "normal" character, put the pointers and character back so that tests for whitespace etc. in the input are done correctly. */ case '\\': { const uschar *save_ptr = ptr; c = check_escape(&ptr, errorptr, bracount, options, FALSE); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if (c >= 0) { ptr = save_ptr; c = '\\'; goto NORMAL_CHAR; } } length++; /* A back reference needs an additional char, plus either one or 5 bytes for a repeat. We also need to keep the value of the highest back reference. */ if (c <= -ESC_REF) { int refnum = -c - ESC_REF; if (refnum > top_backref) top_backref = refnum; length++; /* For single back reference */ if (ptr[1] == '{' && is_counted_repeat(ptr+2)) { ptr = read_repeat_counts(ptr+2, &min, &max, errorptr); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if ((min == 0 && (max == 1 || max == -1)) || (min == 1 && max == -1)) length++; else length += 5; if (ptr[1] == '?') ptr++; } } continue; case '^': case '.': case '$': case '*': /* These repeats won't be after brackets; */ case '+': /* those are handled separately */ case '?': length++; continue; /* This covers the cases of repeats after a single char, metachar, class, or back reference. */ case '{': if (!is_counted_repeat(ptr+1)) goto NORMAL_CHAR; ptr = read_repeat_counts(ptr+1, &min, &max, errorptr); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if ((min == 0 && (max == 1 || max == -1)) || (min == 1 && max == -1)) length++; else { length--; /* Uncount the original char or metachar */ if (min == 1) length++; else if (min > 0) length += 4; if (max > 0) length += 4; else length += 2; } if (ptr[1] == '?') ptr++; continue; /* An alternation contains an offset to the next branch or ket. If any ims options changed in the previous branch(es), and/or if we are in a lookbehind assertion, extra space will be needed at the start of the branch. This is handled by branch_extra. */ case '|': length += 3 + branch_extra; continue; /* A character class uses 33 characters. Don't worry about character types that aren't allowed in classes - they'll get picked up during the compile. A character class that contains only one character uses 2 or 3 bytes, depending on whether it is negated or not. Notice this where we can. */ case '[': class_charcount = 0; if (*(++ptr) == '^') ptr++; do { if (*ptr == '\\') { int ch = check_escape(&ptr, errorptr, bracount, options, TRUE); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if (-ch == ESC_b) class_charcount++; else class_charcount = 10; } else class_charcount++; ptr++; } while (*ptr != 0 && *ptr != ']'); /* Repeats for negated single chars are handled by the general code */ if (class_charcount == 1) length += 3; else { length += 33; /* A repeat needs either 1 or 5 bytes. */ if (*ptr != 0 && ptr[1] == '{' && is_counted_repeat(ptr+2)) { ptr = read_repeat_counts(ptr+2, &min, &max, errorptr); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if ((min == 0 && (max == 1 || max == -1)) || (min == 1 && max == -1)) length++; else length += 5; if (ptr[1] == '?') ptr++; } } continue; /* Brackets may be genuine groups or special things */ case '(': branch_newextra = 0; /* Handle special forms of bracket, which all start (? */ if (ptr[1] == '?') { int set, unset; int *optset; switch (c = ptr[2]) { /* Skip over comments entirely */ case '#': ptr += 3; while (*ptr != 0 && *ptr != ')') ptr++; if (*ptr == 0) { *errorptr = ERR18; goto PCRE_ERROR_RETURN; } continue; /* Non-referencing groups and lookaheads just move the pointer on, and then behave like a non-special bracket, except that they don't increment the count of extracting brackets. Ditto for the "once only" bracket, which is in Perl from version 5.005. */ case ':': case '=': case '!': case '>': ptr += 2; break; /* Lookbehinds are in Perl from version 5.005 */ case '<': if (ptr[3] == '=' || ptr[3] == '!') { ptr += 3; branch_newextra = 3; length += 3; /* For the first branch */ break; } *errorptr = ERR24; goto PCRE_ERROR_RETURN; /* Conditionals are in Perl from version 5.005. The bracket must either be followed by a number (for bracket reference) or by an assertion group. */ case '(': if ((pcre_ctypes[ptr[3]] & ctype_digit) != 0) { ptr += 4; length += 2; while ((pcre_ctypes[*ptr] & ctype_digit) != 0) ptr++; if (*ptr != ')') { *errorptr = ERR26; goto PCRE_ERROR_RETURN; } } else /* An assertion must follow */ { ptr++; /* Can treat like ':' as far as spacing is concerned */ if (ptr[2] != '?' || strchr("=!<", ptr[3]) == NULL) { ptr += 2; /* To get right offset in message */ *errorptr = ERR28; goto PCRE_ERROR_RETURN; } } break; /* Else loop checking valid options until ) is met. Anything else is an error. If we are without any brackets, i.e. at top level, the settings act as if specified in the options, so massage the options immediately. This is for backward compatibility with Perl 5.004. */ default: set = unset = 0; optset = &set; ptr += 2; for (;; ptr++) { c = *ptr; switch (c) { case 'i': *optset |= PCRE_CASELESS; continue; case 'm': *optset |= PCRE_MULTILINE; continue; case 's': *optset |= PCRE_DOTALL; continue; case 'x': *optset |= PCRE_EXTENDED; continue; case 'X': *optset |= PCRE_EXTRA; continue; case 'U': *optset |= PCRE_UNGREEDY; continue; case '-': optset = &unset; continue; /* A termination by ')' indicates an options-setting-only item; this is global at top level; otherwise nothing is done here and it is handled during the compiling process on a per-bracket-group basis. */ case ')': if (brastackptr == 0) { options = (options | set) & (~unset); set = unset = 0; /* To save length */ } /* Fall through */ /* A termination by ':' indicates the start of a nested group with the given options set. This is again handled at compile time, but we must allow for compiled space if any of the ims options are set. We also have to allow for resetting space at the end of the group, which is why 4 is added to the length and not just 2. If there are several changes of options within the same group, this will lead to an over-estimate on the length, but this shouldn't matter very much. We also have to allow for resetting options at the start of any alternations, which we do by setting branch_newextra to 2. */ case ':': if (((set|unset) & PCRE_IMS) != 0) { length += 4; branch_newextra = 2; } goto END_OPTIONS; /* Unrecognized option character */ default: *errorptr = ERR12; goto PCRE_ERROR_RETURN; } } /* If we hit a closing bracket, that's it - this is a freestanding option-setting. We need to ensure that branch_extra is updated if necessary. The only values branch_newextra can have here are 0 or 2. If the value is 2, then branch_extra must either be 2 or 5, depending on whether this is a lookbehind group or not. */ END_OPTIONS: if (c == ')') { if (branch_newextra == 2 && (branch_extra == 0 || branch_extra == 3)) branch_extra += branch_newextra; continue; } /* If options were terminated by ':' control comes here. Fall through to handle the group below. */ } } /* Extracting brackets must be counted so we can process escapes in a Perlish way. */ else bracount++; /* Non-special forms of bracket. Save length for computing whole length at end if there's a repeat that requires duplication of the group. Also save the current value of branch_extra, and start the new group with the new value. If non-zero, this will either be 2 for a (?imsx: group, or 3 for a lookbehind assertion. */ if (brastackptr >= sizeof(brastack)/sizeof(int)) { *errorptr = ERR19; goto PCRE_ERROR_RETURN; } bralenstack[brastackptr] = branch_extra; branch_extra = branch_newextra; brastack[brastackptr++] = length; length += 3; continue; /* Handle ket. Look for subsequent max/min; for certain sets of values we have to replicate this bracket up to that many times. If brastackptr is 0 this is an unmatched bracket which will generate an error, but take care not to try to access brastack[-1] when computing the length and restoring the branch_extra value. */ case ')': length += 3; { int minval = 1; int maxval = 1; int duplength; if (brastackptr > 0) { duplength = length - brastack[--brastackptr]; branch_extra = bralenstack[brastackptr]; } else duplength = 0; /* Leave ptr at the final char; for read_repeat_counts this happens automatically; for the others we need an increment. */ if ((c = ptr[1]) == '{' && is_counted_repeat(ptr+2)) { ptr = read_repeat_counts(ptr+2, &minval, &maxval, errorptr); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; } else if (c == '*') { minval = 0; maxval = -1; ptr++; } else if (c == '+') { maxval = -1; ptr++; } else if (c == '?') { minval = 0; ptr++; } /* If there is a minimum > 1 we have to replicate up to minval-1 times; if there is a limited maximum we have to replicate up to maxval-1 times and allow for a BRAZERO item before each optional copy, as we also have to do before the first copy if the minimum is zero. */ if (minval == 0) length++; else if (minval > 1) length += (minval - 1) * duplength; if (maxval > minval) length += (maxval - minval) * (duplength + 1); } continue; /* Non-special character. For a run of such characters the length required is the number of characters + 2, except that the maximum run length is 255. We won't get a skipped space or a non-data escape or the start of a # comment as the first character, so the length can't be zero. */ NORMAL_CHAR: default: length += 2; runlength = 0; do { if ((options & PCRE_EXTENDED) != 0) { if ((pcre_ctypes[c] & ctype_space) != 0) continue; if (c == '#') { while ((c = *(++ptr)) != 0 && c != '\n'); continue; } } /* Backslash may introduce a data char or a metacharacter; stop the string before the latter. */ if (c == '\\') { const uschar *saveptr = ptr; c = check_escape(&ptr, errorptr, bracount, options, FALSE); if (*errorptr != NULL) goto PCRE_ERROR_RETURN; if (c < 0) { ptr = saveptr; break; } } /* Ordinary character or single-char escape */ runlength++; } /* This "while" is the end of the "do" above. */ while (runlength < 255 && (pcre_ctypes[c = *(++ptr)] & ctype_meta) == 0); ptr--; length += runlength; continue; } } length += 4; /* For final KET and END */ if (length > 65539) { *errorptr = ERR20; return NULL; } /* Compute the size of data block needed and get it, either from malloc or externally provided function. We specify "code[0]" in the offsetof() expression rather than just "code", because it has been reported that one broken compiler fails on "code" because it is also an independent variable. It should make no difference to the value of the offsetof(). */ size = length + offsetof(real_pcre, code[0]); re = (real_pcre *)(pcre_malloc)(size); if (re == NULL) { *errorptr = ERR21; return NULL; } /* Put in the magic number and the options. */ re->magic_number = MAGIC_NUMBER; re->options = options; /* Set up a starting, non-extracting bracket, then compile the expression. On error, *errorptr will be set non-NULL, so we don't need to look at the result of the function here. */ ptr = (const uschar *)pattern; code = re->code; *code = OP_BRA; bracount = 0; (void)compile_regex(options, -1, &bracount, &code, &ptr, errorptr, FALSE, -1); re->top_bracket = bracount; re->top_backref = top_backref; /* If not reached end of pattern on success, there's an excess bracket. */ if (*errorptr == NULL && *ptr != 0) *errorptr = ERR22; /* Fill in the terminating state and check for disastrous overflow, but if debugging, leave the test till after things are printed out. */ *code++ = OP_END; #ifndef DEBUG if (code - re->code > length) *errorptr = ERR23; #endif /* Give an error if there's back reference to a non-existent capturing subpattern. */ if (top_backref > re->top_bracket) *errorptr = ERR15; /* Failed to compile */ if (*errorptr != NULL) { (pcre_free)(re); PCRE_ERROR_RETURN: *erroroffset = ptr - (const uschar *)pattern; return NULL; } /* If the anchored option was not passed, set flag if we can determine that it is anchored by virtue of ^ characters or \A or anything else. Otherwise, see if we can determine what the first character has to be, because that speeds up unanchored matches no end. In the case of multiline matches, an alternative is to set the PCRE_STARTLINE flag if all branches start with ^. */ if ((options & PCRE_ANCHORED) == 0) { int temp_options = options; if (is_anchored(re->code, &temp_options)) re->options |= PCRE_ANCHORED; else { int ch = find_firstchar(re->code, &temp_options); if (ch >= 0) { re->first_char = ch; re->options |= PCRE_FIRSTSET; } else if (is_startline(re->code)) re->options |= PCRE_STARTLINE; } } /* Print out the compiled data for debugging */ #ifdef DEBUG printf("Length = %d top_bracket = %d top_backref = %d\n", length, re->top_bracket, re->top_backref); if (re->options != 0) { printf("%s%s%s%s%s%s%s%s\n", ((re->options & PCRE_ANCHORED) != 0)? "anchored " : "", ((re->options & PCRE_CASELESS) != 0)? "caseless " : "", ((re->options & PCRE_EXTENDED) != 0)? "extended " : "", ((re->options & PCRE_MULTILINE) != 0)? "multiline " : "", ((re->options & PCRE_DOTALL) != 0)? "dotall " : "", ((re->options & PCRE_DOLLAR_ENDONLY) != 0)? "endonly " : "", ((re->options & PCRE_EXTRA) != 0)? "extra " : "", ((re->options & PCRE_UNGREEDY) != 0)? "ungreedy " : ""); } if ((re->options & PCRE_FIRSTSET) != 0) { if (isprint(re->first_char)) printf("First char = %c\n", re->first_char); else printf("First char = \\x%02x\n", re->first_char); } code_end = code; code_base = code = re->code; while (code < code_end) { int charlength; printf("%3d ", code - code_base); if (*code >= OP_BRA) { printf("%3d Bra %d", (code[1] << 8) + code[2], *code - OP_BRA); code += 2; } else switch(*code) { case OP_OPT: printf(" %.2x %s", code[1], OP_names[*code]); code++; break; case OP_COND: printf("%3d Cond", (code[1] << 8) + code[2]); code += 2; break; case OP_CREF: printf(" %.2d %s", code[1], OP_names[*code]); code++; break; case OP_CHARS: charlength = *(++code); printf("%3d ", charlength); while (charlength-- > 0) if (isprint(c = *(++code))) printf("%c", c); else printf("\\x%02x", c); break; case OP_KETRMAX: case OP_KETRMIN: case OP_ALT: case OP_KET: case OP_ASSERT: case OP_ASSERT_NOT: case OP_ASSERTBACK: case OP_ASSERTBACK_NOT: case OP_ONCE: printf("%3d %s", (code[1] << 8) + code[2], OP_names[*code]); code += 2; break; case OP_REVERSE: printf("%3d %s", (code[1] << 8) + code[2], OP_names[*code]); code += 2; break; case OP_STAR: case OP_MINSTAR: case OP_PLUS: case OP_MINPLUS: case OP_QUERY: case OP_MINQUERY: case OP_TYPESTAR: case OP_TYPEMINSTAR: case OP_TYPEPLUS: case OP_TYPEMINPLUS: case OP_TYPEQUERY: case OP_TYPEMINQUERY: if (*code >= OP_TYPESTAR) printf(" %s", OP_names[code[1]]); else if (isprint(c = code[1])) printf(" %c", c); else printf(" \\x%02x", c); printf("%s", OP_names[*code++]); break; case OP_EXACT: case OP_UPTO: case OP_MINUPTO: if (isprint(c = code[3])) printf(" %c{", c); else printf(" \\x%02x{", c); if (*code != OP_EXACT) printf("0,"); printf("%d}", (code[1] << 8) + code[2]); if (*code == OP_MINUPTO) printf("?"); code += 3; break; case OP_TYPEEXACT: case OP_TYPEUPTO: case OP_TYPEMINUPTO: printf(" %s{", OP_names[code[3]]); if (*code != OP_TYPEEXACT) printf(","); printf("%d}", (code[1] << 8) + code[2]); if (*code == OP_TYPEMINUPTO) printf("?"); code += 3; break; case OP_NOT: if (isprint(c = *(++code))) printf(" [^%c]", c); else printf(" [^\\x%02x]", c); break; case OP_NOTSTAR: case OP_NOTMINSTAR: case OP_NOTPLUS: case OP_NOTMINPLUS: case OP_NOTQUERY: case OP_NOTMINQUERY: if (isprint(c = code[1])) printf(" [^%c]", c); else printf(" [^\\x%02x]", c); printf("%s", OP_names[*code++]); break; case OP_NOTEXACT: case OP_NOTUPTO: case OP_NOTMINUPTO: if (isprint(c = code[3])) printf(" [^%c]{", c); else printf(" [^\\x%02x]{", c); if (*code != OP_NOTEXACT) printf(","); printf("%d}", (code[1] << 8) + code[2]); if (*code == OP_NOTMINUPTO) printf("?"); code += 3; break; case OP_REF: printf(" \\%d", *(++code)); code ++; goto CLASS_REF_REPEAT; case OP_CLASS: { int i, min, max; code++; printf(" ["); for (i = 0; i < 256; i++) { if ((code[i/8] & (1 << (i&7))) != 0) { int j; for (j = i+1; j < 256; j++) if ((code[j/8] & (1 << (j&7))) == 0) break; if (i == '-' || i == ']') printf("\\"); if (isprint(i)) printf("%c", i); else printf("\\x%02x", i); if (--j > i) { printf("-"); if (j == '-' || j == ']') printf("\\"); if (isprint(j)) printf("%c", j); else printf("\\x%02x", j); } i = j; } } printf("]"); code += 32; CLASS_REF_REPEAT: switch(*code) { case OP_CRSTAR: case OP_CRMINSTAR: case OP_CRPLUS: case OP_CRMINPLUS: case OP_CRQUERY: case OP_CRMINQUERY: printf("%s", OP_names[*code]); break; case OP_CRRANGE: case OP_CRMINRANGE: min = (code[1] << 8) + code[2]; max = (code[3] << 8) + code[4]; if (max == 0) printf("{%d,}", min); else printf("{%d,%d}", min, max); if (*code == OP_CRMINRANGE) printf("?"); code += 4; break; default: code--; } } break; /* Anything else is just a one-node item */ default: printf(" %s", OP_names[*code]); break; } code++; printf("\n"); } printf("------------------------------------------------------------------\n"); /* This check is done here in the debugging case so that the code that was compiled can be seen. */ if (code - re->code > length) { *errorptr = ERR23; (pcre_free)(re); *erroroffset = ptr - (uschar *)pattern; return NULL; } #endif return (pcre *)re; } /************************************************* * Match a character type * *************************************************/ /* Not used in all the places it might be as it's sometimes faster to put the code inline. Arguments: type the character type c the character dotall the dotall flag Returns: TRUE if character is of the type */ static BOOL match_type(int type, int c, BOOL dotall) { #ifdef DEBUG if (isprint(c)) printf("matching subject %c against ", c); else printf("matching subject \\x%02x against ", c); printf("%s\n", OP_names[type]); #endif switch(type) { case OP_ANY: return dotall || c != '\n'; case OP_NOT_DIGIT: return (pcre_ctypes[c] & ctype_digit) == 0; case OP_DIGIT: return (pcre_ctypes[c] & ctype_digit) != 0; case OP_NOT_WHITESPACE: return (pcre_ctypes[c] & ctype_space) == 0; case OP_WHITESPACE: return (pcre_ctypes[c] & ctype_space) != 0; case OP_NOT_WORDCHAR: return (pcre_ctypes[c] & ctype_word) == 0; case OP_WORDCHAR: return (pcre_ctypes[c] & ctype_word) != 0; } return FALSE; } /************************************************* * Match a back-reference * *************************************************/ /* If a back reference hasn't been set, the length that is passed is greater than the number of characters left in the string, so the match fails. Arguments: offset index into the offset vector eptr points into the subject length length to be matched md points to match data block ims the ims flags Returns: TRUE if matched */ static BOOL match_ref(int offset, register const uschar *eptr, int length, match_data *md, int ims) { const uschar *p = md->start_subject + md->offset_vector[offset]; #ifdef DEBUG if (eptr >= md->end_subject) printf("matching subject "); else { printf("matching subject "); pchars(eptr, length, TRUE, md); } printf(" against backref "); pchars(p, length, FALSE, md); printf("\n"); #endif /* Always fail if not enough characters left */ if (length > md->end_subject - eptr) return FALSE; /* Separate the caselesss case for speed */ if ((ims & PCRE_CASELESS) != 0) { while (length-- > 0) if (pcre_lcc[*p++] != pcre_lcc[*eptr++]) return FALSE; } else { while (length-- > 0) if (*p++ != *eptr++) return FALSE; } return TRUE; } /************************************************* * Match from current position * *************************************************/ /* On entry ecode points to the first opcode, and eptr to the first character in the subject string, while eptrb holds the value of eptr at the start of the last bracketed group - used for breaking infinite loops matching zero-length strings. Arguments: eptr pointer in subject ecode position in code offset_top current top pointer md pointer to "static" info for the match ims current /i, /m, and /s options condassert TRUE if called to check a condition assertion eptrb eptr at start of last bracket Returns: TRUE if matched */ static BOOL match(register const uschar *eptr, register const uschar *ecode, int offset_top, match_data *md, int ims, BOOL condassert, const uschar *eptrb) { int original_ims = ims; /* Save for resetting on ')' */ for (;;) { int op = (int)*ecode; int min, max, ctype; register int i; register int c; BOOL minimize = FALSE; /* Opening capturing bracket. If there is space in the offset vector, save the current subject position in the working slot at the top of the vector. We mustn't change the current values of the data slot, because they may be set from a previous iteration of this group, and be referred to by a reference inside the group. If the bracket fails to match, we need to restore this value and also the values of the final offsets, in case they were set by a previous iteration of the same bracket. If there isn't enough space in the offset vector, treat this as if it were a non-capturing bracket. Don't worry about setting the flag for the error case here; that is handled in the code for KET. */ if (op > OP_BRA) { int number = op - OP_BRA; int offset = number << 1; DPRINTF(("start bracket %d\n", number)); if (offset < md->offset_max) { int save_offset1 = md->offset_vector[offset]; int save_offset2 = md->offset_vector[offset+1]; int save_offset3 = md->offset_vector[md->offset_end - number]; DPRINTF(("saving %d %d %d\n", save_offset1, save_offset2, save_offset3)); md->offset_vector[md->offset_end - number] = eptr - md->start_subject; do { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr)) return TRUE; ecode += (ecode[1] << 8) + ecode[2]; } while (*ecode == OP_ALT); DPRINTF(("bracket %d failed\n", number)); md->offset_vector[offset] = save_offset1; md->offset_vector[offset+1] = save_offset2; md->offset_vector[md->offset_end - number] = save_offset3; return FALSE; } /* Insufficient room for saving captured contents */ else op = OP_BRA; } /* Other types of node can be handled by a switch */ switch(op) { case OP_BRA: /* Non-capturing bracket: optimized */ DPRINTF(("start bracket 0\n")); do { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr)) return TRUE; ecode += (ecode[1] << 8) + ecode[2]; } while (*ecode == OP_ALT); DPRINTF(("bracket 0 failed\n")); return FALSE; /* Conditional group: compilation checked that there are no more than two branches. If the condition is false, skipping the first branch takes us past the end if there is only one branch, but that's OK because that is exactly what going to the ket would do. */ case OP_COND: if (ecode[3] == OP_CREF) /* Condition is extraction test */ { int offset = ecode[4] << 1; /* Doubled reference number */ return match(eptr, ecode + ((offset < offset_top && md->offset_vector[offset] >= 0)? 5 : 3 + (ecode[1] << 8) + ecode[2]), offset_top, md, ims, FALSE, eptr); } /* The condition is an assertion. Call match() to evaluate it - setting the final argument TRUE causes it to stop at the end of an assertion. */ else { if (match(eptr, ecode+3, offset_top, md, ims, TRUE, NULL)) { ecode += 3 + (ecode[4] << 8) + ecode[5]; while (*ecode == OP_ALT) ecode += (ecode[1] << 8) + ecode[2]; } else ecode += (ecode[1] << 8) + ecode[2]; return match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr); } /* Control never reaches here */ /* Skip over conditional reference data if encountered (should not be) */ case OP_CREF: ecode += 2; break; /* End of the pattern */ case OP_END: md->end_match_ptr = eptr; /* Record where we ended */ md->end_offset_top = offset_top; /* and how many extracts were taken */ return TRUE; /* Change option settings */ case OP_OPT: ims = ecode[1]; ecode += 2; DPRINTF(("ims set to %02x\n", ims)); break; /* Assertion brackets. Check the alternative branches in turn - the matching won't pass the KET for an assertion. If any one branch matches, the assertion is true. Lookbehind assertions have an OP_REVERSE item at the start of each branch to move the current point backwards, so the code at this level is identical to the lookahead case. */ case OP_ASSERT: case OP_ASSERTBACK: do { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, NULL)) break; ecode += (ecode[1] << 8) + ecode[2]; } while (*ecode == OP_ALT); if (*ecode == OP_KET) return FALSE; /* If checking an assertion for a condition, return TRUE. */ if (condassert) return TRUE; /* Continue from after the assertion, updating the offsets high water mark, since extracts may have been taken during the assertion. */ do ecode += (ecode[1] << 8) + ecode[2]; while (*ecode == OP_ALT); ecode += 3; offset_top = md->end_offset_top; continue; /* Negative assertion: all branches must fail to match */ case OP_ASSERT_NOT: case OP_ASSERTBACK_NOT: do { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, NULL)) return FALSE; ecode += (ecode[1] << 8) + ecode[2]; } while (*ecode == OP_ALT); if (condassert) return TRUE; ecode += 3; continue; /* Move the subject pointer back. This occurs only at the start of each branch of a lookbehind assertion. If we are too close to the start to move back, this match function fails. */ case OP_REVERSE: eptr -= (ecode[1] << 8) + ecode[2]; if (eptr < md->start_subject) return FALSE; ecode += 3; break; /* "Once" brackets are like assertion brackets except that after a match, the point in the subject string is not moved back. Thus there can never be a move back into the brackets. Check the alternative branches in turn - the matching won't pass the KET for this kind of subpattern. If any one branch matches, we carry on as at the end of a normal bracket, leaving the subject pointer. */ case OP_ONCE: { const uschar *prev = ecode; do { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr)) break; ecode += (ecode[1] << 8) + ecode[2]; } while (*ecode == OP_ALT); /* If hit the end of the group (which could be repeated), fail */ if (*ecode != OP_ONCE && *ecode != OP_ALT) return FALSE; /* Continue as from after the assertion, updating the offsets high water mark, since extracts may have been taken. */ do ecode += (ecode[1] << 8) + ecode[2]; while (*ecode == OP_ALT); offset_top = md->end_offset_top; eptr = md->end_match_ptr; /* For a non-repeating ket, just continue at this level. This also happens for a repeating ket if no characters were matched in the group. This is the forcible breaking of infinite loops as implemented in Perl 5.005. If there is an options reset, it will get obeyed in the normal course of events. */ if (*ecode == OP_KET || eptr == eptrb) { ecode += 3; break; } /* The repeating kets try the rest of the pattern or restart from the preceding bracket, in the appropriate order. We need to reset any options that changed within the bracket before re-running it, so check the next opcode. */ if (ecode[3] == OP_OPT) { ims = (ims & ~PCRE_IMS) | ecode[4]; DPRINTF(("ims set to %02x at group repeat\n", ims)); } if (*ecode == OP_KETRMIN) { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr) || match(eptr, prev, offset_top, md, ims, FALSE, eptr)) return TRUE; } else /* OP_KETRMAX */ { if (match(eptr, prev, offset_top, md, ims, FALSE, eptr) || match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr)) return TRUE; } } return FALSE; /* An alternation is the end of a branch; scan along to find the end of the bracketed group and go to there. */ case OP_ALT: do ecode += (ecode[1] << 8) + ecode[2]; while (*ecode == OP_ALT); break; /* BRAZERO and BRAMINZERO occur just before a bracket group, indicating that it may occur zero times. It may repeat infinitely, or not at all - i.e. it could be ()* or ()? in the pattern. Brackets with fixed upper repeat limits are compiled as a number of copies, with the optional ones preceded by BRAZERO or BRAMINZERO. */ case OP_BRAZERO: { const uschar *next = ecode+1; if (match(eptr, next, offset_top, md, ims, FALSE, eptr)) return TRUE; do next += (next[1] << 8) + next[2]; while (*next == OP_ALT); ecode = next + 3; } break; case OP_BRAMINZERO: { const uschar *next = ecode+1; do next += (next[1] << 8) + next[2]; while (*next == OP_ALT); if (match(eptr, next+3, offset_top, md, ims, FALSE, eptr)) return TRUE; ecode++; } break; /* End of a group, repeated or non-repeating. If we are at the end of an assertion "group", stop matching and return TRUE, but record the current high water mark for use by positive assertions. Do this also for the "once" (not-backup up) groups. */ case OP_KET: case OP_KETRMIN: case OP_KETRMAX: { const uschar *prev = ecode - (ecode[1] << 8) - ecode[2]; if (*prev == OP_ASSERT || *prev == OP_ASSERT_NOT || *prev == OP_ASSERTBACK || *prev == OP_ASSERTBACK_NOT || *prev == OP_ONCE) { md->end_match_ptr = eptr; /* For ONCE */ md->end_offset_top = offset_top; return TRUE; } /* In all other cases except a conditional group we have to check the group number back at the start and if necessary complete handling an extraction by setting the offsets and bumping the high water mark. */ if (*prev != OP_COND) { int number = *prev - OP_BRA; int offset = number << 1; DPRINTF(("end bracket %d\n", number)); if (number > 0) { if (offset >= md->offset_max) md->offset_overflow = TRUE; else { md->offset_vector[offset] = md->offset_vector[md->offset_end - number]; md->offset_vector[offset+1] = eptr - md->start_subject; if (offset_top <= offset) offset_top = offset + 2; } } } /* Reset the value of the ims flags, in case they got changed during the group. */ ims = original_ims; DPRINTF(("ims reset to %02x\n", ims)); /* For a non-repeating ket, just continue at this level. This also happens for a repeating ket if no characters were matched in the group. This is the forcible breaking of infinite loops as implemented in Perl 5.005. If there is an options reset, it will get obeyed in the normal course of events. */ if (*ecode == OP_KET || eptr == eptrb) { ecode += 3; break; } /* The repeating kets try the rest of the pattern or restart from the preceding bracket, in the appropriate order. */ if (*ecode == OP_KETRMIN) { if (match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr) || match(eptr, prev, offset_top, md, ims, FALSE, eptr)) return TRUE; } else /* OP_KETRMAX */ { if (match(eptr, prev, offset_top, md, ims, FALSE, eptr) || match(eptr, ecode+3, offset_top, md, ims, FALSE, eptr)) return TRUE; } } return FALSE; /* Start of subject unless notbol, or after internal newline if multiline */ case OP_CIRC: if (md->notbol && eptr == md->start_subject) return FALSE; if ((ims & PCRE_MULTILINE) != 0) { if (eptr != md->start_subject && eptr[-1] != '\n') return FALSE; ecode++; break; } /* ... else fall through */ /* Start of subject assertion */ case OP_SOD: if (eptr != md->start_subject) return FALSE; ecode++; break; /* Assert before internal newline if multiline, or before a terminating newline unless endonly is set, else end of subject unless noteol is set. */ case OP_DOLL: if ((ims & PCRE_MULTILINE) != 0) { if (eptr < md->end_subject) { if (*eptr != '\n') return FALSE; } else { if (md->noteol) return FALSE; } ecode++; break; } else { if (md->noteol) return FALSE; if (!md->endonly) { if (eptr < md->end_subject - 1 || (eptr == md->end_subject - 1 && *eptr != '\n')) return FALSE; ecode++; break; } } /* ... else fall through */ /* End of subject assertion (\z) */ case OP_EOD: if (eptr < md->end_subject) return FALSE; ecode++; break; /* End of subject or ending \n assertion (\Z) */ case OP_EODN: if (eptr < md->end_subject - 1 || (eptr == md->end_subject - 1 && *eptr != '\n')) return FALSE; ecode++; break; /* Word boundary assertions */ case OP_NOT_WORD_BOUNDARY: case OP_WORD_BOUNDARY: { BOOL prev_is_word = (eptr != md->start_subject) && ((pcre_ctypes[eptr[-1]] & ctype_word) != 0); BOOL cur_is_word = (eptr < md->end_subject) && ((pcre_ctypes[*eptr] & ctype_word) != 0); if ((*ecode++ == OP_WORD_BOUNDARY)? cur_is_word == prev_is_word : cur_is_word != prev_is_word) return FALSE; } break; /* Match a single character type; inline for speed */ case OP_ANY: if ((ims & PCRE_DOTALL) == 0 && eptr < md->end_subject && *eptr == '\n') return FALSE; if (eptr++ >= md->end_subject) return FALSE; ecode++; break; case OP_NOT_DIGIT: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_digit) != 0) return FALSE; ecode++; break; case OP_DIGIT: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_digit) == 0) return FALSE; ecode++; break; case OP_NOT_WHITESPACE: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_space) != 0) return FALSE; ecode++; break; case OP_WHITESPACE: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_space) == 0) return FALSE; ecode++; break; case OP_NOT_WORDCHAR: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_word) != 0) return FALSE; ecode++; break; case OP_WORDCHAR: if (eptr >= md->end_subject || (pcre_ctypes[*eptr++] & ctype_word) == 0) return FALSE; ecode++; break; /* Match a back reference, possibly repeatedly. Look past the end of the item to see if there is repeat information following. The code is similar to that for character classes, but repeated for efficiency. Then obey similar code to character type repeats - written out again for speed. However, if the referenced string is the empty string, always treat it as matched, any number of times (otherwise there could be infinite loops). */ case OP_REF: { int length; int offset = ecode[1] << 1; /* Doubled reference number */ ecode += 2; /* Advance past the item */ /* If the reference is unset, set the length to be longer than the amount of subject left; this ensures that every attempt at a match fails. We can't just fail here, because of the possibility of quantifiers with zero minima. */ length = (offset >= offset_top || md->offset_vector[offset] < 0)? md->end_subject - eptr + 1 : md->offset_vector[offset+1] - md->offset_vector[offset]; /* Set up for repetition, or handle the non-repeated case */ switch (*ecode) { case OP_CRSTAR: case OP_CRMINSTAR: case OP_CRPLUS: case OP_CRMINPLUS: case OP_CRQUERY: case OP_CRMINQUERY: c = *ecode++ - OP_CRSTAR; minimize = (c & 1) != 0; min = rep_min[c]; /* Pick up values from tables; */ max = rep_max[c]; /* zero for max => infinity */ if (max == 0) max = INT_MAX; break; case OP_CRRANGE: case OP_CRMINRANGE: minimize = (*ecode == OP_CRMINRANGE); min = (ecode[1] << 8) + ecode[2]; max = (ecode[3] << 8) + ecode[4]; if (max == 0) max = INT_MAX; ecode += 5; break; default: /* No repeat follows */ if (!match_ref(offset, eptr, length, md, ims)) return FALSE; eptr += length; continue; /* With the main loop */ } /* If the length of the reference is zero, just continue with the main loop. */ if (length == 0) continue; /* First, ensure the minimum number of matches are present. We get back the length of the reference string explicitly rather than passing the address of eptr, so that eptr can be a register variable. */ for (i = 1; i <= min; i++) { if (!match_ref(offset, eptr, length, md, ims)) return FALSE; eptr += length; } /* If min = max, continue at the same level without recursion. They are not both allowed to be zero. */ if (min == max) continue; /* If minimizing, keep trying and advancing the pointer */ if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || !match_ref(offset, eptr, length, md, ims)) return FALSE; eptr += length; } /* Control never gets here */ } /* If maximizing, find the longest string and work backwards */ else { const uschar *pp = eptr; for (i = min; i < max; i++) { if (!match_ref(offset, eptr, length, md, ims)) break; eptr += length; } while (eptr >= pp) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; eptr -= length; } return FALSE; } } /* Control never gets here */ /* Match a character class, possibly repeatedly. Look past the end of the item to see if there is repeat information following. Then obey similar code to character type repeats - written out again for speed. */ case OP_CLASS: { const uschar *data = ecode + 1; /* Save for matching */ ecode += 33; /* Advance past the item */ switch (*ecode) { case OP_CRSTAR: case OP_CRMINSTAR: case OP_CRPLUS: case OP_CRMINPLUS: case OP_CRQUERY: case OP_CRMINQUERY: c = *ecode++ - OP_CRSTAR; minimize = (c & 1) != 0; min = rep_min[c]; /* Pick up values from tables; */ max = rep_max[c]; /* zero for max => infinity */ if (max == 0) max = INT_MAX; break; case OP_CRRANGE: case OP_CRMINRANGE: minimize = (*ecode == OP_CRMINRANGE); min = (ecode[1] << 8) + ecode[2]; max = (ecode[3] << 8) + ecode[4]; if (max == 0) max = INT_MAX; ecode += 5; break; default: /* No repeat follows */ min = max = 1; break; } /* First, ensure the minimum number of matches are present. */ for (i = 1; i <= min; i++) { if (eptr >= md->end_subject) return FALSE; c = *eptr++; if ((data[c/8] & (1 << (c&7))) != 0) continue; return FALSE; } /* If max == min we can continue with the main loop without the need to recurse. */ if (min == max) continue; /* If minimizing, keep testing the rest of the expression and advancing the pointer while it matches the class. */ if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject) return FALSE; c = *eptr++; if ((data[c/8] & (1 << (c&7))) != 0) continue; return FALSE; } /* Control never gets here */ } /* If maximizing, find the longest possible run, then work backwards. */ else { const uschar *pp = eptr; for (i = min; i < max; eptr++, i++) { if (eptr >= md->end_subject) break; c = *eptr; if ((data[c/8] & (1 << (c&7))) != 0) continue; break; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } } /* Control never gets here */ /* Match a run of characters */ case OP_CHARS: { register int length = ecode[1]; ecode += 2; #ifdef DEBUG /* Sigh. Some compilers never learn. */ if (eptr >= md->end_subject) printf("matching subject against pattern "); else { printf("matching subject "); pchars(eptr, length, TRUE, md); printf(" against pattern "); } pchars(ecode, length, FALSE, md); printf("\n"); #endif if (length > md->end_subject - eptr) return FALSE; if ((ims & PCRE_CASELESS) != 0) { while (length-- > 0) if (pcre_lcc[*ecode++] != pcre_lcc[*eptr++]) return FALSE; } else { while (length-- > 0) if (*ecode++ != *eptr++) return FALSE; } } break; /* Match a single character repeatedly; different opcodes share code. */ case OP_EXACT: min = max = (ecode[1] << 8) + ecode[2]; ecode += 3; goto REPEATCHAR; case OP_UPTO: case OP_MINUPTO: min = 0; max = (ecode[1] << 8) + ecode[2]; minimize = *ecode == OP_MINUPTO; ecode += 3; goto REPEATCHAR; case OP_STAR: case OP_MINSTAR: case OP_PLUS: case OP_MINPLUS: case OP_QUERY: case OP_MINQUERY: c = *ecode++ - OP_STAR; minimize = (c & 1) != 0; min = rep_min[c]; /* Pick up values from tables; */ max = rep_max[c]; /* zero for max => infinity */ if (max == 0) max = INT_MAX; /* Common code for all repeated single-character matches. We can give up quickly if there are fewer than the minimum number of characters left in the subject. */ REPEATCHAR: if (min > md->end_subject - eptr) return FALSE; c = *ecode++; /* The code is duplicated for the caseless and caseful cases, for speed, since matching characters is likely to be quite common. First, ensure the minimum number of matches are present. If min = max, continue at the same level without recursing. Otherwise, if minimizing, keep trying the rest of the expression and advancing one matching character if failing, up to the maximum. Alternatively, if maximizing, find the maximum number of characters and work backwards. */ DPRINTF(("matching %c{%d,%d} against subject %.*s\n", c, min, max, max, eptr)); if ((ims & PCRE_CASELESS) != 0) { c = pcre_lcc[c]; for (i = 1; i <= min; i++) if (c != pcre_lcc[*eptr++]) return FALSE; if (min == max) continue; if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject || c != pcre_lcc[*eptr++]) return FALSE; } /* Control never gets here */ } else { const uschar *pp = eptr; for (i = min; i < max; i++) { if (eptr >= md->end_subject || c != pcre_lcc[*eptr]) break; eptr++; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } /* Control never gets here */ } /* Caseful comparisons */ else { for (i = 1; i <= min; i++) if (c != *eptr++) return FALSE; if (min == max) continue; if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject || c != *eptr++) return FALSE; } /* Control never gets here */ } else { const uschar *pp = eptr; for (i = min; i < max; i++) { if (eptr >= md->end_subject || c != *eptr) break; eptr++; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } } /* Control never gets here */ /* Match a negated single character */ case OP_NOT: if (eptr >= md->end_subject) return FALSE; ecode++; if ((ims & PCRE_CASELESS) != 0) { if (pcre_lcc[*ecode++] == pcre_lcc[*eptr++]) return FALSE; } else { if (*ecode++ == *eptr++) return FALSE; } break; /* Match a negated single character repeatedly. This is almost a repeat of the code for a repeated single character, but I haven't found a nice way of commoning these up that doesn't require a test of the positive/negative option for each character match. Maybe that wouldn't add very much to the time taken, but character matching *is* what this is all about... */ case OP_NOTEXACT: min = max = (ecode[1] << 8) + ecode[2]; ecode += 3; goto REPEATNOTCHAR; case OP_NOTUPTO: case OP_NOTMINUPTO: min = 0; max = (ecode[1] << 8) + ecode[2]; minimize = *ecode == OP_NOTMINUPTO; ecode += 3; goto REPEATNOTCHAR; case OP_NOTSTAR: case OP_NOTMINSTAR: case OP_NOTPLUS: case OP_NOTMINPLUS: case OP_NOTQUERY: case OP_NOTMINQUERY: c = *ecode++ - OP_NOTSTAR; minimize = (c & 1) != 0; min = rep_min[c]; /* Pick up values from tables; */ max = rep_max[c]; /* zero for max => infinity */ if (max == 0) max = INT_MAX; /* Common code for all repeated single-character matches. We can give up quickly if there are fewer than the minimum number of characters left in the subject. */ REPEATNOTCHAR: if (min > md->end_subject - eptr) return FALSE; c = *ecode++; /* The code is duplicated for the caseless and caseful cases, for speed, since matching characters is likely to be quite common. First, ensure the minimum number of matches are present. If min = max, continue at the same level without recursing. Otherwise, if minimizing, keep trying the rest of the expression and advancing one matching character if failing, up to the maximum. Alternatively, if maximizing, find the maximum number of characters and work backwards. */ DPRINTF(("negative matching %c{%d,%d} against subject %.*s\n", c, min, max, max, eptr)); if ((ims & PCRE_CASELESS) != 0) { c = pcre_lcc[c]; for (i = 1; i <= min; i++) if (c == pcre_lcc[*eptr++]) return FALSE; if (min == max) continue; if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject || c == pcre_lcc[*eptr++]) return FALSE; } /* Control never gets here */ } else { const uschar *pp = eptr; for (i = min; i < max; i++) { if (eptr >= md->end_subject || c == pcre_lcc[*eptr]) break; eptr++; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } /* Control never gets here */ } /* Caseful comparisons */ else { for (i = 1; i <= min; i++) if (c == *eptr++) return FALSE; if (min == max) continue; if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject || c == *eptr++) return FALSE; } /* Control never gets here */ } else { const uschar *pp = eptr; for (i = min; i < max; i++) { if (eptr >= md->end_subject || c == *eptr) break; eptr++; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } } /* Control never gets here */ /* Match a single character type repeatedly; several different opcodes share code. This is very similar to the code for single characters, but we repeat it in the interests of efficiency. */ case OP_TYPEEXACT: min = max = (ecode[1] << 8) + ecode[2]; minimize = TRUE; ecode += 3; goto REPEATTYPE; case OP_TYPEUPTO: case OP_TYPEMINUPTO: min = 0; max = (ecode[1] << 8) + ecode[2]; minimize = *ecode == OP_TYPEMINUPTO; ecode += 3; goto REPEATTYPE; case OP_TYPESTAR: case OP_TYPEMINSTAR: case OP_TYPEPLUS: case OP_TYPEMINPLUS: case OP_TYPEQUERY: case OP_TYPEMINQUERY: c = *ecode++ - OP_TYPESTAR; minimize = (c & 1) != 0; min = rep_min[c]; /* Pick up values from tables; */ max = rep_max[c]; /* zero for max => infinity */ if (max == 0) max = INT_MAX; /* Common code for all repeated single character type matches */ REPEATTYPE: ctype = *ecode++; /* Code for the character type */ /* First, ensure the minimum number of matches are present. Use inline code for maximizing the speed, and do the type test once at the start (i.e. keep it out of the loop). Also test that there are at least the minimum number of characters before we start. */ if (min > md->end_subject - eptr) return FALSE; if (min > 0) switch(ctype) { case OP_ANY: if ((ims & PCRE_DOTALL) == 0) { for (i = 1; i <= min; i++) if (*eptr++ == '\n') return FALSE; } else eptr += min; break; case OP_NOT_DIGIT: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_digit) != 0) return FALSE; break; case OP_DIGIT: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_digit) == 0) return FALSE; break; case OP_NOT_WHITESPACE: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_space) != 0) return FALSE; break; case OP_WHITESPACE: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_space) == 0) return FALSE; break; case OP_NOT_WORDCHAR: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_word) != 0) return FALSE; break; case OP_WORDCHAR: for (i = 1; i <= min; i++) if ((pcre_ctypes[*eptr++] & ctype_word) == 0) return FALSE; break; } /* If min = max, continue at the same level without recursing */ if (min == max) continue; /* If minimizing, we have to test the rest of the pattern before each subsequent match, so inlining isn't much help; just use the function. */ if (minimize) { for (i = min;; i++) { if (match(eptr, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; if (i >= max || eptr >= md->end_subject || !match_type(ctype, *eptr++, (ims & PCRE_DOTALL) != 0)) return FALSE; } /* Control never gets here */ } /* If maximizing it is worth using inline code for speed, doing the type test once at the start (i.e. keep it out of the loop). */ else { const uschar *pp = eptr; switch(ctype) { case OP_ANY: if ((ims & PCRE_DOTALL) == 0) { for (i = min; i < max; i++) { if (eptr >= md->end_subject || *eptr == '\n') break; eptr++; } } else { c = max - min; if (c > md->end_subject - eptr) c = md->end_subject - eptr; eptr += c; } break; case OP_NOT_DIGIT: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_digit) != 0) break; eptr++; } break; case OP_DIGIT: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_digit) == 0) break; eptr++; } break; case OP_NOT_WHITESPACE: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_space) != 0) break; eptr++; } break; case OP_WHITESPACE: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_space) == 0) break; eptr++; } break; case OP_NOT_WORDCHAR: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_word) != 0) break; eptr++; } break; case OP_WORDCHAR: for (i = min; i < max; i++) { if (eptr >= md->end_subject || (pcre_ctypes[*eptr] & ctype_word) == 0) break; eptr++; } break; } while (eptr >= pp) if (match(eptr--, ecode, offset_top, md, ims, FALSE, eptrb)) return TRUE; return FALSE; } /* Control never gets here */ /* There's been some horrible disaster. */ default: DPRINTF(("Unknown opcode %d\n", *ecode)); md->errorcode = PCRE_ERROR_UNKNOWN_NODE; return FALSE; } /* Do not stick any code in here without much thought; it is assumed that "continue" in the code above comes out to here to repeat the main loop. */ } /* End of main loop */ /* Control never reaches here */ } /************************************************* * Execute a Regular Expression * *************************************************/ /* This function applies a compiled re to a subject string and picks out portions of the string if it matches. Two elements in the vector are set for each substring: the offsets to the start and end of the substring. Arguments: external_re points to the compiled expression external_extra points to "hints" from pcre_study() or is NULL subject points to the subject string length length of subject string (may contain binary zeros) options option bits offsets points to a vector of ints to be filled in with offsets offsetcount the number of elements in the vector Returns: > 0 => success; value is the number of elements filled in = 0 => success, but offsets is not big enough -1 => failed to match < -1 => some kind of unexpected problem */ int pcre_exec(const pcre *external_re, const pcre_extra *external_extra, const char *subject, int length, int options, int *offsets, int offsetcount) { int resetcount, ocount; int first_char = -1; int ims = 0; match_data match_block; const uschar *start_bits = NULL; const uschar *start_match = (const uschar *)subject; const uschar *end_subject; const real_pcre *re = (const real_pcre *)external_re; const real_pcre_extra *extra = (const real_pcre_extra *)external_extra; BOOL using_temporary_offsets = FALSE; BOOL anchored = ((re->options | options) & PCRE_ANCHORED) != 0; BOOL startline = (re->options & PCRE_STARTLINE) != 0; if ((options & ~PUBLIC_EXEC_OPTIONS) != 0) return PCRE_ERROR_BADOPTION; if (re == NULL || subject == NULL || (offsets == NULL && offsetcount > 0)) return PCRE_ERROR_NULL; if (re->magic_number != MAGIC_NUMBER) return PCRE_ERROR_BADMAGIC; match_block.start_subject = (const uschar *)subject; match_block.end_subject = match_block.start_subject + length; end_subject = match_block.end_subject; match_block.endonly = (re->options & PCRE_DOLLAR_ENDONLY) != 0; match_block.notbol = (options & PCRE_NOTBOL) != 0; match_block.noteol = (options & PCRE_NOTEOL) != 0; match_block.errorcode = PCRE_ERROR_NOMATCH; /* Default error */ /* The ims options can vary during the matching as a result of the presence of (?ims) items in the pattern. They are kept in a local variable so that restoring at the exit of a group is easy. */ ims = re->options & (PCRE_CASELESS|PCRE_MULTILINE|PCRE_DOTALL); /* If the expression has got more back references than the offsets supplied can hold, we get a temporary bit of working store to use during the matching. Otherwise, we can use the vector supplied, rounding down its size to a multiple of 3. */ ocount = offsetcount - (offsetcount % 3); if (re->top_backref > 0 && re->top_backref >= ocount/3) { ocount = re->top_backref * 3 + 3; match_block.offset_vector = (int *)(pcre_malloc)(ocount * sizeof(int)); if (match_block.offset_vector == NULL) return PCRE_ERROR_NOMEMORY; using_temporary_offsets = TRUE; DPRINTF(("Got memory to hold back references\n")); } else match_block.offset_vector = offsets; match_block.offset_end = ocount; match_block.offset_max = (2*ocount)/3; match_block.offset_overflow = FALSE; /* Compute the minimum number of offsets that we need to reset each time. Doing this makes a huge difference to execution time when there aren't many brackets in the pattern. */ resetcount = 2 + re->top_bracket * 2; if (resetcount > offsetcount) resetcount = ocount; /* Set up the first character to match, if available. The first_char value is never set for an anchored regular expression, but the anchoring may be forced at run time, so we have to test for anchoring. The first char may be unset for an unanchored pattern, of course. If there's no first char and the pattern was studied, there may be a bitmap of possible first characters. */ if (!anchored) { if ((re->options & PCRE_FIRSTSET) != 0) { first_char = re->first_char; if ((ims & PCRE_CASELESS) != 0) first_char = pcre_lcc[first_char]; } else if (!startline && extra != NULL && (extra->options & PCRE_STUDY_MAPPED) != 0) start_bits = extra->start_bits; } /* Loop for unanchored matches; for anchored regexps the loop runs just once. */ do { int rc; register int *iptr = match_block.offset_vector; register int *iend = iptr + resetcount; /* Reset the maximum number of extractions we might see. */ while (iptr < iend) *iptr++ = -1; /* Advance to a unique first char if possible */ if (first_char >= 0) { if ((ims & PCRE_CASELESS) != 0) while (start_match < end_subject && pcre_lcc[*start_match] != first_char) start_match++; else while (start_match < end_subject && *start_match != first_char) start_match++; } /* Or to just after \n for a multiline match if possible */ else if (startline) { if (start_match > match_block.start_subject) { while (start_match < end_subject && start_match[-1] != '\n') start_match++; } } /* Or to a non-unique first char */ else if (start_bits != NULL) { while (start_match < end_subject) { register int c = *start_match; if ((start_bits[c/8] & (1 << (c&7))) == 0) start_match++; else break; } } #ifdef DEBUG /* Sigh. Some compilers never learn. */ printf(">>>> Match against: "); pchars(start_match, end_subject - start_match, TRUE, &match_block); printf("\n"); #endif /* When a match occurs, substrings will be set for all internal extractions; we just need to set up the whole thing as substring 0 before returning. If there were too many extractions, set the return code to zero. In the case where we had to get some local store to hold offsets for backreferences, copy those back references that we can. In this case there need not be overflow if certain parts of the pattern were not used. */ if (!match(start_match, re->code, 2, &match_block, ims, FALSE, start_match)) continue; /* Copy the offset information from temporary store if necessary */ if (using_temporary_offsets) { if (offsetcount >= 4) { memcpy(offsets + 2, match_block.offset_vector + 2, (offsetcount - 2) * sizeof(int)); DPRINTF(("Copied offsets from temporary memory\n")); } if (match_block.end_offset_top > offsetcount) match_block.offset_overflow = TRUE; DPRINTF(("Freeing temporary memory\n")); (pcre_free)(match_block.offset_vector); } rc = match_block.offset_overflow? 0 : match_block.end_offset_top/2; if (match_block.offset_end < 2) rc = 0; else { offsets[0] = start_match - match_block.start_subject; offsets[1] = match_block.end_match_ptr - match_block.start_subject; } DPRINTF((">>>> returning %d\n", rc)); return rc; } while (!anchored && match_block.errorcode == PCRE_ERROR_NOMATCH && start_match++ < end_subject); if (using_temporary_offsets) { DPRINTF(("Freeing temporary memory\n")); (pcre_free)(match_block.offset_vector); } DPRINTF((">>>> returning %d\n", match_block.errorcode)); return match_block.errorcode; } /* End of pcre.c */