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Diffstat (limited to 'Source/JavaScriptCore/pcre/pcre_compile.cpp')
| -rw-r--r-- | Source/JavaScriptCore/pcre/pcre_compile.cpp | 2708 |
1 files changed, 2708 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/pcre/pcre_compile.cpp b/Source/JavaScriptCore/pcre/pcre_compile.cpp new file mode 100644 index 0000000..9d472d8 --- /dev/null +++ b/Source/JavaScriptCore/pcre/pcre_compile.cpp @@ -0,0 +1,2708 @@ +/* This is JavaScriptCore's variant of the PCRE library. While this library +started out as a copy of PCRE, many of the features of PCRE have been +removed. This library now supports only the regular expression features +required by the JavaScript language specification, and has only the functions +needed by JavaScriptCore and the rest of WebKit. + + Originally written by Philip Hazel + Copyright (c) 1997-2006 University of Cambridge + Copyright (C) 2002, 2004, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved. + Copyright (C) 2007 Eric Seidel <eric@webkit.org> + +----------------------------------------------------------------------------- +Redistribution and use in source and binary forms, with or without +modification, are permitted provided that the following conditions are met: + + * Redistributions of source code must retain the above copyright notice, + this list of conditions and the following disclaimer. + + * Redistributions in binary form must reproduce the above copyright + notice, this list of conditions and the following disclaimer in the + documentation and/or other materials provided with the distribution. + + * Neither the name of the University of Cambridge nor the names of its + contributors may be used to endorse or promote products derived from + this software without specific prior written permission. + +THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" +AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE +IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE +ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE +LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR +CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF +SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS +INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN +CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) +ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE +POSSIBILITY OF SUCH DAMAGE. +----------------------------------------------------------------------------- +*/ + +/* This module contains the external function jsRegExpExecute(), along with +supporting internal functions that are not used by other modules. */ + +#include "config.h" + +#include "pcre_internal.h" + +#include <string.h> +#include <wtf/ASCIICType.h> +#include <wtf/FastMalloc.h> +#include <wtf/FixedArray.h> +#include <wtf/StdLibExtras.h> + +using namespace WTF; + +/* Negative values for the firstchar and reqchar variables */ + +#define REQ_UNSET (-2) +#define REQ_NONE (-1) + +/************************************************* +* Code parameters and static tables * +*************************************************/ + +/* Maximum number of items on the nested bracket stacks at compile time. This +applies to the nesting of all kinds of parentheses. It does not limit +un-nested, non-capturing parentheses. This number can be made bigger if +necessary - it is used to dimension one int and one unsigned char vector at +compile time. */ + +#define BRASTACK_SIZE 200 + +/* 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 escapes[] = { + 0, 0, 0, 0, 0, 0, 0, 0, /* 0 - 7 */ + 0, 0, ':', ';', '<', '=', '>', '?', /* 8 - ? */ + '@', 0, -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, 0, '[', '\\', ']', '^', '_', /* X - _ */ + '`', 7, -ESC_b, 0, -ESC_d, 0, '\f', 0, /* ` - g */ + 0, 0, 0, 0, 0, 0, '\n', 0, /* h - o */ + 0, 0, '\r', -ESC_s, '\t', 0, '\v', -ESC_w, /* p - w */ + 0, 0, 0 /* x - z */ +}; + +/* Error code numbers. They are given names so that they can more easily be +tracked. */ + +enum ErrorCode { + ERR0, ERR1, ERR2, ERR3, ERR4, ERR5, ERR6, ERR7, ERR8, ERR9, + ERR10, ERR11, ERR12, ERR13, ERR14, ERR15, ERR16, ERR17 +}; + +/* The texts of compile-time error messages. These are "char *" because they +are passed to the outside world. */ + +static const char* errorText(ErrorCode code) +{ + static const char errorTexts[] = + /* 1 */ + "\\ at end of pattern\0" + "\\c at end of pattern\0" + "character value in \\x{...} sequence is too large\0" + "numbers out of order in {} quantifier\0" + /* 5 */ + "number too big in {} quantifier\0" + "missing terminating ] for character class\0" + "internal error: code overflow\0" + "range out of order in character class\0" + "nothing to repeat\0" + /* 10 */ + "unmatched parentheses\0" + "internal error: unexpected repeat\0" + "unrecognized character after (?\0" + "failed to get memory\0" + "missing )\0" + /* 15 */ + "reference to non-existent subpattern\0" + "regular expression too large\0" + "parentheses nested too deeply" + ; + + int i = code; + const char* text = errorTexts; + while (i > 1) + i -= !*text++; + return text; +} + +/* Structure for passing "static" information around between the functions +doing the compiling. */ + +struct CompileData { + CompileData() { + topBackref = 0; + backrefMap = 0; + reqVaryOpt = 0; + needOuterBracket = false; + numCapturingBrackets = 0; + } + int topBackref; /* Maximum back reference */ + unsigned backrefMap; /* Bitmap of low back refs */ + int reqVaryOpt; /* "After variable item" flag for reqByte */ + bool needOuterBracket; + int numCapturingBrackets; +}; + +/* Definitions to allow mutual recursion */ + +static bool compileBracket(int, int*, unsigned char**, const UChar**, const UChar*, ErrorCode*, int, int*, int*, CompileData&); +static bool bracketIsAnchored(const unsigned char* code); +static bool bracketNeedsLineStart(const unsigned char* code, unsigned captureMap, unsigned backrefMap); +static int bracketFindFirstAssertedCharacter(const unsigned char* code, bool inassert); + +/************************************************* +* 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. When UTF-8 is enabled, +a positive value greater than 255 may be returned. 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 + errorCodePtr points to the errorcode variable + 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 checkEscape(const UChar** ptrPtr, const UChar* patternEnd, ErrorCode* errorCodePtr, int bracount, bool isClass) +{ + const UChar* ptr = *ptrPtr + 1; + + /* If backslash is at the end of the pattern, it's an error. */ + if (ptr == patternEnd) { + *errorCodePtr = ERR1; + *ptrPtr = ptr; + return 0; + } + + int c = *ptr; + + /* Non-alphamerics are literals. For digits or letters, do an initial lookup in + a table. A non-zero result is something that can be returned immediately. + Otherwise further processing may be required. */ + + if (c < '0' || c > 'z') { /* Not alphameric */ + } else if (int escapeValue = escapes[c - '0']) { + c = escapeValue; + if (isClass) { + if (-c == ESC_b) + c = '\b'; /* \b is backslash in a class */ + else if (-c == ESC_B) + c = 'B'; /* and \B is a capital B in a class (in browsers event though ECMAScript 15.10.2.19 says it raises an error) */ + } + /* Escapes that need further processing, or are illegal. */ + + } else { + switch (c) { + case '1': + case '2': + case '3': + case '4': + case '5': + case '6': + case '7': + case '8': + case '9': + /* Escape sequences starting with a non-zero digit are backreferences, + unless there are insufficient brackets, in which case they are octal + escape sequences. Those sequences end on the first non-octal character + or when we overflow 0-255, whichever comes first. */ + + if (!isClass) { + const UChar* oldptr = ptr; + c -= '0'; + while ((ptr + 1 < patternEnd) && isASCIIDigit(ptr[1]) && c <= bracount) + c = c * 10 + *(++ptr) - '0'; + if (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, + this is not octal. */ + + if ((c = *ptr) >= '8') { + c = '\\'; + ptr -= 1; + break; + } + + /* \0 always starts an octal number, but we may drop through to here with a + larger first octal digit. */ + + case '0': { + c -= '0'; + int i; + for (i = 1; i <= 2; ++i) { + if (ptr + i >= patternEnd || ptr[i] < '0' || ptr[i] > '7') + break; + int cc = c * 8 + ptr[i] - '0'; + if (cc > 255) + break; + c = cc; + } + ptr += i - 1; + break; + } + + case 'x': { + c = 0; + int i; + for (i = 1; i <= 2; ++i) { + if (ptr + i >= patternEnd || !isASCIIHexDigit(ptr[i])) { + c = 'x'; + i = 1; + break; + } + int cc = ptr[i]; + if (cc >= 'a') + cc -= 32; /* Convert to upper case */ + c = c * 16 + cc - ((cc < 'A') ? '0' : ('A' - 10)); + } + ptr += i - 1; + break; + } + + case 'u': { + c = 0; + int i; + for (i = 1; i <= 4; ++i) { + if (ptr + i >= patternEnd || !isASCIIHexDigit(ptr[i])) { + c = 'u'; + i = 1; + break; + } + int cc = ptr[i]; + if (cc >= 'a') + cc -= 32; /* Convert to upper case */ + c = c * 16 + cc - ((cc < 'A') ? '0' : ('A' - 10)); + } + ptr += i - 1; + break; + } + + case 'c': + if (++ptr == patternEnd) { + *errorCodePtr = ERR2; + return 0; + } + + c = *ptr; + + /* To match Firefox, inside a character class, we also accept + numbers and '_' as control characters */ + if ((!isClass && !isASCIIAlpha(c)) || (!isASCIIAlphanumeric(c) && c != '_')) { + c = '\\'; + ptr -= 2; + break; + } + + /* A letter is upper-cased; then the 0x40 bit is flipped. This coding + is ASCII-specific, but then the whole concept of \cx is ASCII-specific. */ + c = toASCIIUpper(c) ^ 0x40; + 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 isCountedRepeat(const UChar* p, const UChar* patternEnd) +{ + if (p >= patternEnd || !isASCIIDigit(*p)) + return false; + p++; + while (p < patternEnd && isASCIIDigit(*p)) + p++; + if (p < patternEnd && *p == '}') + return true; + + if (p >= patternEnd || *p++ != ',') + return false; + if (p < patternEnd && *p == '}') + return true; + + if (p >= patternEnd || !isASCIIDigit(*p)) + return false; + p++; + while (p < patternEnd && isASCIIDigit(*p)) + p++; + + return (p < patternEnd && *p == '}'); +} + +/************************************************* +* Read repeat counts * +*************************************************/ + +/* Read an item of the form {n,m} and return the values. This is called only +after isCountedRepeat() 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 + errorCodePtr points to error code variable + +Returns: pointer to '}' on success; + current ptr on error, with errorCodePtr set non-zero +*/ + +static const UChar* readRepeatCounts(const UChar* p, int* minp, int* maxp, ErrorCode* errorCodePtr) +{ + int min = 0; + int max = -1; + + /* Read the minimum value and do a paranoid check: a negative value indicates + an integer overflow. */ + + while (isASCIIDigit(*p)) + min = min * 10 + *p++ - '0'; + if (min < 0 || min > 65535) { + *errorCodePtr = ERR5; + return p; + } + + /* Read the maximum value if there is one, and again do a paranoid on its size. + Also, max must not be less than min. */ + + if (*p == '}') + max = min; + else { + if (*(++p) != '}') { + max = 0; + while (isASCIIDigit(*p)) + max = max * 10 + *p++ - '0'; + if (max < 0 || max > 65535) { + *errorCodePtr = ERR5; + return p; + } + if (max < min) { + *errorCodePtr = ERR4; + return p; + } + } + } + + /* Fill in the required variables, and pass back the pointer to the terminating + '}'. */ + + *minp = min; + *maxp = max; + return p; +} + +/************************************************* +* 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. + +Arguments: + code pointer to the start of the group +Returns: pointer to the first significant opcode +*/ + +static const unsigned char* firstSignificantOpcode(const unsigned char* code) +{ + while (*code == OP_BRANUMBER) + code += 3; + return code; +} + +static const unsigned char* firstSignificantOpcodeSkippingAssertions(const unsigned char* code) +{ + while (true) { + switch (*code) { + case OP_ASSERT_NOT: + advanceToEndOfBracket(code); + code += 1 + LINK_SIZE; + break; + case OP_WORD_BOUNDARY: + case OP_NOT_WORD_BOUNDARY: + ++code; + break; + case OP_BRANUMBER: + code += 3; + break; + default: + return code; + } + } +} + +/************************************************* +* Get othercase range * +*************************************************/ + +/* This function is passed the start and end of a class range, in UTF-8 mode +with UCP support. It searches up the characters, looking for internal ranges of +characters in the "other" case. Each call returns the next one, updating the +start address. + +Arguments: + cptr points to starting character value; updated + d end value + ocptr where to put start of othercase range + odptr where to put end of othercase range + +Yield: true when range returned; false when no more +*/ + +static bool getOthercaseRange(int* cptr, int d, int* ocptr, int* odptr) +{ + int c, othercase = 0; + + for (c = *cptr; c <= d; c++) { + if ((othercase = jsc_pcre_ucp_othercase(c)) >= 0) + break; + } + + if (c > d) + return false; + + *ocptr = othercase; + int next = othercase + 1; + + for (++c; c <= d; c++) { + if (jsc_pcre_ucp_othercase(c) != next) + break; + next++; + } + + *odptr = next - 1; + *cptr = c; + + return true; +} + +/************************************************* + * Convert character value to UTF-8 * + *************************************************/ + +/* This function takes an integer value in the range 0 - 0x7fffffff + and encodes it as a UTF-8 character in 0 to 6 bytes. + + Arguments: + cvalue the character value + buffer pointer to buffer for result - at least 6 bytes long + + Returns: number of characters placed in the buffer + */ + +static int encodeUTF8(int cvalue, unsigned char *buffer) +{ + int i; + for (i = 0; i < jsc_pcre_utf8_table1_size; i++) + if (cvalue <= jsc_pcre_utf8_table1[i]) + break; + buffer += i; + for (int j = i; j > 0; j--) { + *buffer-- = 0x80 | (cvalue & 0x3f); + cvalue >>= 6; + } + *buffer = jsc_pcre_utf8_table2[i] | cvalue; + return i + 1; +} + +/************************************************* +* Compile one branch * +*************************************************/ + +/* Scan the pattern, compiling it into the code vector. + +Arguments: + options the option bits + brackets points to number of extracting brackets used + codePtr points to the pointer to the current code point + ptrPtr points to the current pattern pointer + errorCodePtr points to error code variable + firstbyteptr set to initial literal character, or < 0 (REQ_UNSET, REQ_NONE) + reqbyteptr set to the last literal character required, else < 0 + cd contains pointers to tables etc. + +Returns: true on success + false, with *errorCodePtr set non-zero on error +*/ + +static inline bool safelyCheckNextChar(const UChar* ptr, const UChar* patternEnd, UChar expected) +{ + return ((ptr + 1 < patternEnd) && ptr[1] == expected); +} + +static bool +compileBranch(int options, int* brackets, unsigned char** codePtr, + const UChar** ptrPtr, const UChar* patternEnd, ErrorCode* errorCodePtr, int *firstbyteptr, + int* reqbyteptr, CompileData& cd) +{ + int repeatType, opType; + int repeatMin = 0, repeat_max = 0; /* To please picky compilers */ + int bravalue = 0; + int reqvary, tempreqvary; + int c; + unsigned char* code = *codePtr; + unsigned char* tempcode; + bool didGroupSetFirstByte = false; + const UChar* ptr = *ptrPtr; + const UChar* tempptr; + unsigned char* previous = NULL; + unsigned char classbits[32]; + + bool class_utf8; + unsigned char* class_utf8data; + unsigned char utf8_char[6]; + + /* Initialize no first byte, no required byte. REQ_UNSET means "no char + matching encountered yet". It gets changed to REQ_NONE if we hit something that + matches a non-fixed char first char; reqByte just remains unset if we never + find one. + + When we hit a repeat whose minimum is zero, we may have to adjust these values + to take the zero repeat into account. This is implemented by setting them to + zeroFirstByte and zeroReqByte when such a repeat is encountered. The individual + item types that can be repeated set these backoff variables appropriately. */ + + int firstByte = REQ_UNSET; + int reqByte = REQ_UNSET; + int zeroReqByte = REQ_UNSET; + int zeroFirstByte = REQ_UNSET; + + /* The variable reqCaseOpt contains either the REQ_IGNORE_CASE value or zero, + according to the current setting of the ignores-case flag. REQ_IGNORE_CASE is a bit + value > 255. It is added into the firstByte or reqByte variables to record the + case status of the value. This is used only for ASCII characters. */ + + int reqCaseOpt = (options & IgnoreCaseOption) ? REQ_IGNORE_CASE : 0; + + /* Switch on next character until the end of the branch */ + + for (;; ptr++) { + bool negateClass; + bool shouldFlipNegation; /* If a negative special such as \S is used, we should negate the whole class to properly support Unicode. */ + int classCharCount; + int classLastChar; + int skipBytes; + int subReqByte; + int subFirstByte; + int mcLength; + unsigned char mcbuffer[8]; + + /* Next byte in the pattern */ + + c = ptr < patternEnd ? *ptr : 0; + + /* Fill in length of a previous callout, except when the next thing is + a quantifier. */ + + bool isQuantifier = c == '*' || c == '+' || c == '?' || (c == '{' && isCountedRepeat(ptr + 1, patternEnd)); + + switch (c) { + /* The branch terminates at end of string, |, or ). */ + + case 0: + if (ptr < patternEnd) + goto NORMAL_CHAR; + // End of string; fall through + case '|': + case ')': + *firstbyteptr = firstByte; + *reqbyteptr = reqByte; + *codePtr = code; + *ptrPtr = ptr; + return true; + + /* Handle single-character metacharacters. In multiline mode, ^ disables + the setting of any following char as a first character. */ + + case '^': + if (options & MatchAcrossMultipleLinesOption) { + if (firstByte == REQ_UNSET) + firstByte = REQ_NONE; + *code++ = OP_BOL; + } else + *code++ = OP_CIRC; + previous = NULL; + break; + + case '$': + previous = NULL; + if (options & MatchAcrossMultipleLinesOption) + *code++ = OP_EOL; + else + *code++ = OP_DOLL; + break; + + /* There can never be a first char if '.' is first, whatever happens about + repeats. The value of reqByte doesn't change either. */ + + case '.': + if (firstByte == REQ_UNSET) + firstByte = REQ_NONE; + zeroFirstByte = firstByte; + zeroReqByte = reqByte; + previous = code; + *code++ = OP_NOT_NEWLINE; + break; + + /* Character classes. If the included characters are all < 256, we build a + 32-byte bitmap of the permitted characters, except in the special case + where there is only one such character. For negated classes, we build the + map as usual, then invert it at the end. However, we use a different opcode + so that data characters > 255 can be handled correctly. + + If the class contains characters outside the 0-255 range, a different + opcode is compiled. It may optionally have a bit map for characters < 256, + but those above are are explicitly listed afterwards. A flag byte tells + whether the bitmap is present, and whether this is a negated class or not. + */ + + case '[': { + previous = code; + shouldFlipNegation = false; + + /* PCRE supports POSIX class stuff inside a class. Perl gives an error if + they are encountered at the top level, so we'll do that too. */ + + /* If the first character is '^', set the negation flag and skip it. */ + + if (ptr + 1 >= patternEnd) { + *errorCodePtr = ERR6; + return false; + } + + if (ptr[1] == '^') { + negateClass = true; + ++ptr; + } else + negateClass = false; + + /* Keep a count of chars with values < 256 so that we can optimize the case + of just a single character (as long as it's < 256). For higher valued UTF-8 + characters, we don't yet do any optimization. */ + + classCharCount = 0; + classLastChar = -1; + + class_utf8 = false; /* No chars >= 256 */ + class_utf8data = code + LINK_SIZE + 34; /* For UTF-8 items */ + + /* 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 (< 256), because in that case the compiled code doesn't use the + bit map. */ + + memset(classbits, 0, 32 * sizeof(unsigned char)); + + /* Process characters until ] is reached. The first pass + through the regex checked the overall syntax, so we don't need to be very + strict here. At the start of the loop, c contains the first byte of the + character. */ + + while ((++ptr < patternEnd) && (c = *ptr) != ']') { + /* 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 classCharCount bigger than one. */ + + if (c == '\\') { + c = checkEscape(&ptr, patternEnd, errorCodePtr, cd.numCapturingBrackets, true); + if (c < 0) { + classCharCount += 2; /* Greater than 1 is what matters */ + switch (-c) { + case ESC_d: + for (c = 0; c < 32; c++) + classbits[c] |= classBitmapForChar(c + cbit_digit); + continue; + + case ESC_D: + shouldFlipNegation = true; + for (c = 0; c < 32; c++) + classbits[c] |= ~classBitmapForChar(c + cbit_digit); + continue; + + case ESC_w: + for (c = 0; c < 32; c++) + classbits[c] |= classBitmapForChar(c + cbit_word); + continue; + + case ESC_W: + shouldFlipNegation = true; + for (c = 0; c < 32; c++) + classbits[c] |= ~classBitmapForChar(c + cbit_word); + continue; + + case ESC_s: + for (c = 0; c < 32; c++) + classbits[c] |= classBitmapForChar(c + cbit_space); + continue; + + case ESC_S: + shouldFlipNegation = true; + for (c = 0; c < 32; c++) + classbits[c] |= ~classBitmapForChar(c + cbit_space); + continue; + + /* Unrecognized escapes are faulted if PCRE is running in its + strict mode. By default, for compatibility with Perl, they are + treated as literals. */ + + default: + c = *ptr; /* The final character */ + classCharCount -= 2; /* Undo the default count from above */ + } + } + + /* Fall through if we have a single character (c >= 0). This may be + > 256 in UTF-8 mode. */ + + } /* End of backslash handling */ + + /* 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 + 2 < patternEnd) && ptr[1] == '-' && ptr[2] != ']') { + ptr += 2; + + int d = *ptr; + + /* The second part of a range can be a single-character escape, but + not any of the other escapes. Perl 5.6 treats a hyphen as a literal + in such circumstances. */ + + if (d == '\\') { + const UChar* oldptr = ptr; + d = checkEscape(&ptr, patternEnd, errorCodePtr, cd.numCapturingBrackets, true); + + /* \X is literal X; any other special means the '-' was literal */ + if (d < 0) { + ptr = oldptr - 2; + goto LONE_SINGLE_CHARACTER; /* A few lines below */ + } + } + + /* The check that the two values are in the correct order happens in + the pre-pass. Optimize one-character ranges */ + + if (d == c) + goto LONE_SINGLE_CHARACTER; /* A few lines below */ + + /* In UTF-8 mode, if the upper limit is > 255, or > 127 for caseless + matching, we have to use an XCLASS with extra data items. Caseless + matching for characters > 127 is available only if UCP support is + available. */ + + if ((d > 255 || ((options & IgnoreCaseOption) && d > 127))) { + class_utf8 = true; + + /* With UCP support, we can find the other case equivalents of + the relevant characters. There may be several ranges. Optimize how + they fit with the basic range. */ + + if (options & IgnoreCaseOption) { + int occ, ocd; + int cc = c; + int origd = d; + while (getOthercaseRange(&cc, origd, &occ, &ocd)) { + if (occ >= c && ocd <= d) + continue; /* Skip embedded ranges */ + + if (occ < c && ocd >= c - 1) /* Extend the basic range */ + { /* if there is overlap, */ + c = occ; /* noting that if occ < c */ + continue; /* we can't have ocd > d */ + } /* because a subrange is */ + if (ocd > d && occ <= d + 1) /* always shorter than */ + { /* the basic range. */ + d = ocd; + continue; + } + + if (occ == ocd) + *class_utf8data++ = XCL_SINGLE; + else { + *class_utf8data++ = XCL_RANGE; + class_utf8data += encodeUTF8(occ, class_utf8data); + } + class_utf8data += encodeUTF8(ocd, class_utf8data); + } + } + + /* Now record the original range, possibly modified for UCP caseless + overlapping ranges. */ + + *class_utf8data++ = XCL_RANGE; + class_utf8data += encodeUTF8(c, class_utf8data); + class_utf8data += encodeUTF8(d, class_utf8data); + + /* With UCP support, we are done. Without UCP support, there is no + caseless matching for UTF-8 characters > 127; we can use the bit map + for the smaller ones. */ + + continue; /* With next character in the class */ + } + + /* We use the bit map for all cases when not in UTF-8 mode; else + ranges that lie entirely within 0-127 when there is UCP support; else + for partial ranges without UCP support. */ + + for (; c <= d; c++) { + classbits[c/8] |= (1 << (c&7)); + if (options & IgnoreCaseOption) { + int uc = flipCase(c); + classbits[uc/8] |= (1 << (uc&7)); + } + classCharCount++; /* in case a one-char range */ + classLastChar = 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 or for an + apparent range that isn't. */ + + LONE_SINGLE_CHARACTER: + + /* Handle a character that cannot go in the bit map */ + + if ((c > 255 || ((options & IgnoreCaseOption) && c > 127))) { + class_utf8 = true; + *class_utf8data++ = XCL_SINGLE; + class_utf8data += encodeUTF8(c, class_utf8data); + + if (options & IgnoreCaseOption) { + int othercase; + if ((othercase = jsc_pcre_ucp_othercase(c)) >= 0) { + *class_utf8data++ = XCL_SINGLE; + class_utf8data += encodeUTF8(othercase, class_utf8data); + } + } + } else { + /* Handle a single-byte character */ + classbits[c/8] |= (1 << (c&7)); + if (options & IgnoreCaseOption) { + c = flipCase(c); + classbits[c/8] |= (1 << (c&7)); + } + classCharCount++; + classLastChar = c; + } + } + + /* If classCharCount is 1, we saw precisely one character whose value is + less than 256. In non-UTF-8 mode we can always optimize. In UTF-8 mode, we + can optimize the negative case only if there were no characters >= 128 + because OP_NOT and the related opcodes like OP_NOTSTAR operate on + single-bytes only. This is an historical hangover. Maybe one day we can + tidy these opcodes to handle multi-byte characters. + + The optimization throws away the bit map. We turn the item into a + 1-character OP_CHAR[NC] if it's positive, or OP_NOT if it's negative. Note + that OP_NOT does not support multibyte characters. In the positive case, it + can cause firstByte to be set. Otherwise, there can be no first char if + this item is first, whatever repeat count may follow. In the case of + reqByte, save the previous value for reinstating. */ + + if (classCharCount == 1 && (!class_utf8 && (!negateClass || classLastChar < 128))) { + zeroReqByte = reqByte; + + /* The OP_NOT opcode works on one-byte characters only. */ + + if (negateClass) { + if (firstByte == REQ_UNSET) + firstByte = REQ_NONE; + zeroFirstByte = firstByte; + *code++ = OP_NOT; + *code++ = classLastChar; + break; + } + + /* For a single, positive character, get the value into c, and + then we can handle this with the normal one-character code. */ + + c = classLastChar; + goto NORMAL_CHAR; + } /* End of 1-char optimization */ + + /* The general case - not the one-char optimization. If this is the first + thing in the branch, there can be no first char setting, whatever the + repeat count. Any reqByte setting must remain unchanged after any kind of + repeat. */ + + if (firstByte == REQ_UNSET) firstByte = REQ_NONE; + zeroFirstByte = firstByte; + zeroReqByte = reqByte; + + /* If there are characters with values > 255, we have to compile an + extended class, with its own opcode. If there are no characters < 256, + we can omit the bitmap. */ + + if (class_utf8 && !shouldFlipNegation) { + *class_utf8data++ = XCL_END; /* Marks the end of extra data */ + *code++ = OP_XCLASS; + code += LINK_SIZE; + *code = negateClass? XCL_NOT : 0; + + /* If the map is required, install it, and move on to the end of + the extra data */ + + if (classCharCount > 0) { + *code++ |= XCL_MAP; + memcpy(code, classbits, 32); + code = class_utf8data; + } + + /* If the map is not required, slide down the extra data. */ + + else { + int len = class_utf8data - (code + 33); + memmove(code + 1, code + 33, len); + code += len + 1; + } + + /* Now fill in the complete length of the item */ + + putLinkValue(previous + 1, code - previous); + break; /* End of class handling */ + } + + /* If there are no characters > 255, negate the 32-byte map if necessary, + and copy it into the code vector. If this is the first thing in the branch, + there can be no first char setting, whatever the repeat count. Any reqByte + setting must remain unchanged after any kind of repeat. */ + + *code++ = (negateClass == shouldFlipNegation) ? OP_CLASS : OP_NCLASS; + if (negateClass) + for (c = 0; c < 32; c++) + code[c] = ~classbits[c]; + else + memcpy(code, classbits, 32); + code += 32; + break; + } + + /* Various kinds of repeat; '{' is not necessarily a quantifier, but this + has been tested above. */ + + case '{': + if (!isQuantifier) + goto NORMAL_CHAR; + ptr = readRepeatCounts(ptr + 1, &repeatMin, &repeat_max, errorCodePtr); + if (*errorCodePtr) + goto FAILED; + goto REPEAT; + + case '*': + repeatMin = 0; + repeat_max = -1; + goto REPEAT; + + case '+': + repeatMin = 1; + repeat_max = -1; + goto REPEAT; + + case '?': + repeatMin = 0; + repeat_max = 1; + + REPEAT: + if (!previous) { + *errorCodePtr = ERR9; + goto FAILED; + } + + if (repeatMin == 0) { + firstByte = zeroFirstByte; /* Adjust for zero repeat */ + reqByte = zeroReqByte; /* Ditto */ + } + + /* Remember whether this is a variable length repeat */ + + reqvary = (repeatMin == repeat_max) ? 0 : REQ_VARY; + + opType = 0; /* Default single-char op codes */ + + /* Save start of previous item, in case we have to move it up to make space + for an inserted OP_ONCE for the additional '+' extension. */ + /* FIXME: Probably don't need this because we don't use OP_ONCE. */ + + tempcode = previous; + + /* If the next character is '+', we have a possessive quantifier. This + implies greediness, whatever the setting of the PCRE_UNGREEDY option. + If the next character is '?' this is a minimizing repeat, by default, + but if PCRE_UNGREEDY is set, it works the other way round. We change the + repeat type to the non-default. */ + + if (safelyCheckNextChar(ptr, patternEnd, '?')) { + repeatType = 1; + ptr++; + } else + repeatType = 0; + + /* If previous was a character match, abolish the item and generate a + repeat item instead. If a char item has a minumum of more than one, ensure + that it is set in reqByte - it might not be if a sequence such as x{3} is + the first thing in a branch because the x will have gone into firstByte + instead. */ + + if (*previous == OP_CHAR || *previous == OP_CHAR_IGNORING_CASE) { + /* Deal with UTF-8 characters that take up more than one byte. It's + easier to write this out separately than try to macrify it. Use c to + hold the length of the character in bytes, plus 0x80 to flag that it's a + length rather than a small character. */ + + if (code[-1] & 0x80) { + unsigned char *lastchar = code - 1; + while((*lastchar & 0xc0) == 0x80) + lastchar--; + c = code - lastchar; /* Length of UTF-8 character */ + memcpy(utf8_char, lastchar, c); /* Save the char */ + c |= 0x80; /* Flag c as a length */ + } + else { + c = code[-1]; + if (repeatMin > 1) + reqByte = c | reqCaseOpt | cd.reqVaryOpt; + } + + goto OUTPUT_SINGLE_REPEAT; /* Code shared with single character types */ + } + + else if (*previous == OP_ASCII_CHAR || *previous == OP_ASCII_LETTER_IGNORING_CASE) { + c = previous[1]; + if (repeatMin > 1) + reqByte = c | reqCaseOpt | cd.reqVaryOpt; + goto OUTPUT_SINGLE_REPEAT; + } + + /* 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 setting opt_type to add a suitable offset into + repeatType. OP_NOT is currently used only for single-byte chars. */ + + else if (*previous == OP_NOT) { + opType = OP_NOTSTAR - OP_STAR; /* Use "not" opcodes */ + c = previous[1]; + 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 setting opType to add a suitable offset into repeatType. */ + + else if (*previous <= OP_NOT_NEWLINE) { + opType = OP_TYPESTAR - OP_STAR; /* Use type opcodes */ + c = *previous; + + OUTPUT_SINGLE_REPEAT: + int prop_type = -1; + int prop_value = -1; + + unsigned char* oldcode = code; + code = previous; /* Usually overwrite previous item */ + + /* 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) + goto END_REPEAT; + + /* Combine the opType with the repeatType */ + + repeatType += opType; + + /* A minimum of zero is handled either as the special case * or ?, or as + an UPTO, with the maximum given. */ + + if (repeatMin == 0) { + if (repeat_max == -1) + *code++ = OP_STAR + repeatType; + else if (repeat_max == 1) + *code++ = OP_QUERY + repeatType; + else { + *code++ = OP_UPTO + repeatType; + put2ByteValueAndAdvance(code, repeat_max); + } + } + + /* A repeat minimum of 1 is optimized into some special cases. If the + maximum is unlimited, we use OP_PLUS. Otherwise, the original item it + left in place and, if the maximum is greater than 1, we use OP_UPTO with + one less than the maximum. */ + + else if (repeatMin == 1) { + if (repeat_max == -1) + *code++ = OP_PLUS + repeatType; + else { + code = oldcode; /* leave previous item in place */ + if (repeat_max == 1) + goto END_REPEAT; + *code++ = OP_UPTO + repeatType; + put2ByteValueAndAdvance(code, repeat_max - 1); + } + } + + /* The case {n,n} is just an EXACT, while the general case {n,m} is + handled as an EXACT followed by an UPTO. */ + + else { + *code++ = OP_EXACT + opType; /* NB EXACT doesn't have repeatType */ + put2ByteValueAndAdvance(code, repeatMin); + + /* If the maximum is unlimited, insert an OP_STAR. Before doing so, + we have to insert the character for the previous code. For a repeated + Unicode property match, there are two extra bytes that define the + required property. In UTF-8 mode, long characters have their length in + c, with the 0x80 bit as a flag. */ + + if (repeat_max < 0) { + if (c >= 128) { + memcpy(code, utf8_char, c & 7); + code += c & 7; + } else { + *code++ = c; + if (prop_type >= 0) { + *code++ = prop_type; + *code++ = prop_value; + } + } + *code++ = OP_STAR + repeatType; + } + + /* Else insert an UPTO if the max is greater than the min, again + preceded by the character, for the previously inserted code. */ + + else if (repeat_max != repeatMin) { + if (c >= 128) { + memcpy(code, utf8_char, c & 7); + code += c & 7; + } else + *code++ = c; + if (prop_type >= 0) { + *code++ = prop_type; + *code++ = prop_value; + } + repeat_max -= repeatMin; + *code++ = OP_UPTO + repeatType; + put2ByteValueAndAdvance(code, repeat_max); + } + } + + /* The character or character type itself comes last in all cases. */ + + if (c >= 128) { + memcpy(code, utf8_char, c & 7); + code += c & 7; + } else + *code++ = c; + + /* For a repeated Unicode property match, there are two extra bytes that + define the required property. */ + + if (prop_type >= 0) { + *code++ = prop_type; + *code++ = prop_value; + } + } + + /* If previous was a character class or a back reference, we put the repeat + stuff after it, but just skip the item if the repeat was {0,0}. */ + + else if (*previous == OP_CLASS || + *previous == OP_NCLASS || + *previous == OP_XCLASS || + *previous == OP_REF) + { + if (repeat_max == 0) { + code = previous; + goto END_REPEAT; + } + + if (repeatMin == 0 && repeat_max == -1) + *code++ = OP_CRSTAR + repeatType; + else if (repeatMin == 1 && repeat_max == -1) + *code++ = OP_CRPLUS + repeatType; + else if (repeatMin == 0 && repeat_max == 1) + *code++ = OP_CRQUERY + repeatType; + else { + *code++ = OP_CRRANGE + repeatType; + put2ByteValueAndAdvance(code, repeatMin); + if (repeat_max == -1) + repeat_max = 0; /* 2-byte encoding for max */ + put2ByteValueAndAdvance(code, repeat_max); + } + } + + /* If previous was a bracket group, we may have to replicate it in certain + cases. */ + + else if (*previous >= OP_BRA) { + int ketoffset = 0; + int len = code - previous; + unsigned char* bralink = NULL; + + /* 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) { + const unsigned char* ket = previous; + advanceToEndOfBracket(ket); + ketoffset = code - ket; + } + + /* The case of a zero minimum is special because of the need to stick + OP_BRAZERO in front of it, and because the group appears once in the + data, whereas in other cases it appears the minimum number of times. For + this reason, it is simplest to treat this case separately, as otherwise + the code gets far too messy. There are several special subcases when the + minimum is zero. */ + + if (repeatMin == 0) { + /* If the maximum is also zero, we just omit the group from the output + altogether. */ + + if (repeat_max == 0) { + code = previous; + goto END_REPEAT; + } + + /* If the maximum is 1 or unlimited, we just have to stick in the + BRAZERO and do no more at this point. However, we do need to adjust + any OP_RECURSE calls inside the group that refer to the group itself or + any internal group, because the offset is from the start of the whole + regex. Temporarily terminate the pattern while doing this. */ + + if (repeat_max <= 1) { + *code = OP_END; + memmove(previous+1, previous, len); + code++; + *previous++ = OP_BRAZERO + repeatType; + } + + /* If the maximum is greater than 1 and limited, we have to replicate + in a nested fashion, sticking OP_BRAZERO before each set of brackets. + The first one has to be handled carefully because it's the original + copy, which has to be moved up. The remainder can be handled by code + that is common with the non-zero minimum case below. We have to + adjust the value of repeat_max, since one less copy is required. */ + + else { + *code = OP_END; + memmove(previous + 2 + LINK_SIZE, previous, len); + code += 2 + LINK_SIZE; + *previous++ = OP_BRAZERO + repeatType; + *previous++ = OP_BRA; + + /* We chain together the bracket offset fields that have to be + filled in later when the ends of the brackets are reached. */ + + int offset = (!bralink) ? 0 : previous - bralink; + bralink = previous; + putLinkValueAllowZeroAndAdvance(previous, offset); + } + + repeat_max--; + } + + /* If the minimum is greater than zero, replicate the group as many + times as necessary, and adjust the maximum to the number of subsequent + copies that we need. If we set a first char from the group, and didn't + set a required char, copy the latter from the former. */ + + else { + if (repeatMin > 1) { + if (didGroupSetFirstByte && reqByte < 0) + reqByte = firstByte; + for (int i = 1; i < repeatMin; i++) { + memcpy(code, previous, len); + code += len; + } + } + if (repeat_max > 0) + repeat_max -= repeatMin; + } + + /* This code is common to both the zero and non-zero minimum cases. If + the maximum is limited, it replicates the group in a nested fashion, + remembering the bracket starts on a stack. In the case of a zero minimum, + the first one was set up above. In all cases the repeat_max now specifies + the number of additional copies needed. */ + + if (repeat_max >= 0) { + for (int i = repeat_max - 1; i >= 0; i--) { + *code++ = OP_BRAZERO + repeatType; + + /* All but the final copy start a new nesting, maintaining the + chain of brackets outstanding. */ + + if (i != 0) { + *code++ = OP_BRA; + int offset = (!bralink) ? 0 : code - bralink; + bralink = code; + putLinkValueAllowZeroAndAdvance(code, offset); + } + + memcpy(code, previous, len); + code += len; + } + + /* Now chain through the pending brackets, and fill in their length + fields (which are holding the chain links pro tem). */ + + while (bralink) { + int offset = code - bralink + 1; + unsigned char* bra = code - offset; + int oldlinkoffset = getLinkValueAllowZero(bra + 1); + bralink = (!oldlinkoffset) ? 0 : bralink - oldlinkoffset; + *code++ = OP_KET; + putLinkValueAndAdvance(code, offset); + putLinkValue(bra + 1, offset); + } + } + + /* 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. */ + + else + code[-ketoffset] = OP_KETRMAX + repeatType; + } + + // A quantifier after an assertion is mostly meaningless, but it + // can nullify the assertion if it has a 0 minimum. + else if (*previous == OP_ASSERT || *previous == OP_ASSERT_NOT) { + if (repeatMin == 0) { + code = previous; + goto END_REPEAT; + } + } + + /* Else there's some kind of shambles */ + + else { + *errorCodePtr = ERR11; + goto FAILED; + } + + /* In all case we no longer have a previous item. We also set the + "follows varying string" flag for subsequently encountered reqbytes if + it isn't already set and we have just passed a varying length item. */ + + END_REPEAT: + previous = NULL; + cd.reqVaryOpt |= reqvary; + 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 '(': + skipBytes = 0; + + if (*(++ptr) == '?') { + switch (*(++ptr)) { + case ':': /* Non-extracting bracket */ + bravalue = OP_BRA; + ptr++; + break; + + case '=': /* Positive lookahead */ + bravalue = OP_ASSERT; + ptr++; + break; + + case '!': /* Negative lookahead */ + bravalue = OP_ASSERT_NOT; + ptr++; + break; + + /* Character after (? not specially recognized */ + + default: + *errorCodePtr = ERR12; + goto FAILED; + } + } + + /* Else we have a referencing group; adjust the opcode. If the bracket + number is greater than EXTRACT_BASIC_MAX, we set the opcode one higher, and + arrange for the true number to follow later, in an OP_BRANUMBER item. */ + + else { + if (++(*brackets) > EXTRACT_BASIC_MAX) { + bravalue = OP_BRA + EXTRACT_BASIC_MAX + 1; + code[1 + LINK_SIZE] = OP_BRANUMBER; + put2ByteValue(code + 2 + LINK_SIZE, *brackets); + skipBytes = 3; + } + else + bravalue = OP_BRA + *brackets; + } + + /* Process nested bracketed re. We copy code into a non-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 = code; + *code = bravalue; + tempcode = code; + tempreqvary = cd.reqVaryOpt; /* Save value before bracket */ + + if (!compileBracket( + options, + brackets, /* Extracting bracket count */ + &tempcode, /* Where to put code (updated) */ + &ptr, /* Input pointer (updated) */ + patternEnd, + errorCodePtr, /* Where to put an error message */ + skipBytes, /* Skip over OP_BRANUMBER */ + &subFirstByte, /* For possible first char */ + &subReqByte, /* For possible last char */ + cd)) /* Tables block */ + 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. */ + + /* Handle updating of the required and first characters. Update for normal + brackets of all kinds, and conditions with two branches (see code above). + If the bracket is followed by a quantifier with zero repeat, we have to + back off. Hence the definition of zeroReqByte and zeroFirstByte outside the + main loop so that they can be accessed for the back off. */ + + zeroReqByte = reqByte; + zeroFirstByte = firstByte; + didGroupSetFirstByte = false; + + if (bravalue >= OP_BRA) { + /* If we have not yet set a firstByte in this branch, take it from the + subpattern, remembering that it was set here so that a repeat of more + than one can replicate it as reqByte if necessary. If the subpattern has + no firstByte, set "none" for the whole branch. In both cases, a zero + repeat forces firstByte to "none". */ + + if (firstByte == REQ_UNSET) { + if (subFirstByte >= 0) { + firstByte = subFirstByte; + didGroupSetFirstByte = true; + } + else + firstByte = REQ_NONE; + zeroFirstByte = REQ_NONE; + } + + /* If firstByte was previously set, convert the subpattern's firstByte + into reqByte if there wasn't one, using the vary flag that was in + existence beforehand. */ + + else if (subFirstByte >= 0 && subReqByte < 0) + subReqByte = subFirstByte | tempreqvary; + + /* If the subpattern set a required byte (or set a first byte that isn't + really the first byte - see above), set it. */ + + if (subReqByte >= 0) + reqByte = subReqByte; + } + + /* For a forward assertion, we take the reqByte, if set. This can be + helpful if the pattern that follows the assertion doesn't set a different + char. For example, it's useful for /(?=abcde).+/. We can't set firstByte + for an assertion, however because it leads to incorrect effect for patterns + such as /(?=a)a.+/ when the "real" "a" would then become a reqByte instead + of a firstByte. This is overcome by a scan at the end if there's no + firstByte, looking for an asserted first char. */ + + else if (bravalue == OP_ASSERT && subReqByte >= 0) + reqByte = subReqByte; + + /* Now update the main code pointer to the end of the group. */ + + code = tempcode; + + /* Error if hit end of pattern */ + + if (ptr >= patternEnd || *ptr != ')') { + *errorCodePtr = 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 = checkEscape(&ptr, patternEnd, errorCodePtr, cd.numCapturingBrackets, 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_w for the latter; this may + have to change if any new ones are ever created. */ + + if (c < 0) { + /* For metasequences that actually match a character, we disable the + setting of a first character if it hasn't already been set. */ + + if (firstByte == REQ_UNSET && -c > ESC_b && -c <= ESC_w) + firstByte = REQ_NONE; + + /* Set values to reset to if this is followed by a zero repeat. */ + + zeroFirstByte = firstByte; + zeroReqByte = reqByte; + + /* Back references are handled specially */ + + if (-c >= ESC_REF) { + int number = -c - ESC_REF; + previous = code; + *code++ = OP_REF; + put2ByteValueAndAdvance(code, number); + } + + /* For the rest, we can obtain the OP value by negating the escape + value */ + + else { + previous = (-c > ESC_b && -c <= ESC_w) ? code : NULL; + *code++ = -c; + } + continue; + } + + /* Fall through. */ + + /* Handle a literal character. It is guaranteed not to be whitespace or # + when the extended flag is set. If we are in UTF-8 mode, it may be a + multi-byte literal character. */ + + default: + NORMAL_CHAR: + + previous = code; + + if (c < 128) { + mcLength = 1; + mcbuffer[0] = c; + + if ((options & IgnoreCaseOption) && (c | 0x20) >= 'a' && (c | 0x20) <= 'z') { + *code++ = OP_ASCII_LETTER_IGNORING_CASE; + *code++ = c | 0x20; + } else { + *code++ = OP_ASCII_CHAR; + *code++ = c; + } + } else { + mcLength = encodeUTF8(c, mcbuffer); + + *code++ = (options & IgnoreCaseOption) ? OP_CHAR_IGNORING_CASE : OP_CHAR; + for (c = 0; c < mcLength; c++) + *code++ = mcbuffer[c]; + } + + /* Set the first and required bytes appropriately. If no previous first + byte, set it from this character, but revert to none on a zero repeat. + Otherwise, leave the firstByte value alone, and don't change it on a zero + repeat. */ + + if (firstByte == REQ_UNSET) { + zeroFirstByte = REQ_NONE; + zeroReqByte = reqByte; + + /* If the character is more than one byte long, we can set firstByte + only if it is not to be matched caselessly. */ + + if (mcLength == 1 || reqCaseOpt == 0) { + firstByte = mcbuffer[0] | reqCaseOpt; + if (mcLength != 1) + reqByte = code[-1] | cd.reqVaryOpt; + } + else + firstByte = reqByte = REQ_NONE; + } + + /* firstByte was previously set; we can set reqByte only the length is + 1 or the matching is caseful. */ + + else { + zeroFirstByte = firstByte; + zeroReqByte = reqByte; + if (mcLength == 1 || reqCaseOpt == 0) + reqByte = code[-1] | reqCaseOpt | cd.reqVaryOpt; + } + + break; /* End of literal character handling */ + } + } /* 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 option bits, including any changes for this subpattern + 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 + errorCodePtr -> pointer to error code variable + skipBytes skip this many bytes at start (for OP_BRANUMBER) + firstbyteptr place to put the first required character, or a negative number + reqbyteptr place to put the last required character, or a negative number + cd points to the data block with tables pointers etc. + +Returns: true on success +*/ + +static bool +compileBracket(int options, int* brackets, unsigned char** codePtr, + const UChar** ptrPtr, const UChar* patternEnd, ErrorCode* errorCodePtr, int skipBytes, + int* firstbyteptr, int* reqbyteptr, CompileData& cd) +{ + const UChar* ptr = *ptrPtr; + unsigned char* code = *codePtr; + unsigned char* lastBranch = code; + unsigned char* start_bracket = code; + int firstByte = REQ_UNSET; + int reqByte = REQ_UNSET; + + /* Offset is set zero to mark that this bracket is still open */ + + putLinkValueAllowZero(code + 1, 0); + code += 1 + LINK_SIZE + skipBytes; + + /* Loop for each alternative branch */ + + while (true) { + /* Now compile the branch */ + + int branchFirstByte; + int branchReqByte; + if (!compileBranch(options, brackets, &code, &ptr, patternEnd, errorCodePtr, + &branchFirstByte, &branchReqByte, cd)) { + *ptrPtr = ptr; + return false; + } + + /* If this is the first branch, the firstByte and reqByte values for the + branch become the values for the regex. */ + + if (*lastBranch != OP_ALT) { + firstByte = branchFirstByte; + reqByte = branchReqByte; + } + + /* If this is not the first branch, the first char and reqByte have to + match the values from all the previous branches, except that if the previous + value for reqByte didn't have REQ_VARY set, it can still match, and we set + REQ_VARY for the regex. */ + + else { + /* If we previously had a firstByte, but it doesn't match the new branch, + we have to abandon the firstByte for the regex, but if there was previously + no reqByte, it takes on the value of the old firstByte. */ + + if (firstByte >= 0 && firstByte != branchFirstByte) { + if (reqByte < 0) + reqByte = firstByte; + firstByte = REQ_NONE; + } + + /* If we (now or from before) have no firstByte, a firstByte from the + branch becomes a reqByte if there isn't a branch reqByte. */ + + if (firstByte < 0 && branchFirstByte >= 0 && branchReqByte < 0) + branchReqByte = branchFirstByte; + + /* Now ensure that the reqbytes match */ + + if ((reqByte & ~REQ_VARY) != (branchReqByte & ~REQ_VARY)) + reqByte = REQ_NONE; + else + reqByte |= branchReqByte; /* To "or" REQ_VARY */ + } + + /* Reached end of expression, either ')' or end of pattern. Go back through + the alternative branches and reverse the chain of offsets, with the field in + the BRA item now becoming an offset to the first alternative. If there are + no alternatives, it points to the end of the group. The length in the + terminating ket is always the length of the whole bracketed item. If any of + the ims options were changed inside the group, compile a resetting op-code + following, except at the very end of the pattern. Return leaving the pointer + at the terminating char. */ + + if (ptr >= patternEnd || *ptr != '|') { + int length = code - lastBranch; + do { + int prevLength = getLinkValueAllowZero(lastBranch + 1); + putLinkValue(lastBranch + 1, length); + length = prevLength; + lastBranch -= length; + } while (length > 0); + + /* Fill in the ket */ + + *code = OP_KET; + putLinkValue(code + 1, code - start_bracket); + code += 1 + LINK_SIZE; + + /* Set values to pass back */ + + *codePtr = code; + *ptrPtr = ptr; + *firstbyteptr = firstByte; + *reqbyteptr = reqByte; + return true; + } + + /* Another branch follows; insert an "or" node. Its length field points back + to the previous branch while the bracket remains open. At the end the chain + is reversed. It's done like this so that the start of the bracket has a + zero offset until it is closed, making it possible to detect recursion. */ + + *code = OP_ALT; + putLinkValue(code + 1, code - lastBranch); + lastBranch = code; + code += 1 + LINK_SIZE; + ptr++; + } + ASSERT_NOT_REACHED(); +} + +/************************************************* +* Check for anchored expression * +*************************************************/ + +/* Try to find out if this is an anchored regular expression. Consider each +alternative branch. If they all start OP_CIRC, or with a bracket +all of whose alternatives start OP_CIRC (recurse ad lib), then +it's anchored. + +Arguments: + code points to start of expression (the bracket) + captureMap a bitmap of which brackets we are inside while testing; this + handles up to substring 31; all brackets after that share + the zero bit + backrefMap the back reference bitmap +*/ + +static bool branchIsAnchored(const unsigned char* code) +{ + const unsigned char* scode = firstSignificantOpcode(code); + int op = *scode; + + /* Brackets */ + if (op >= OP_BRA || op == OP_ASSERT) + return bracketIsAnchored(scode); + + /* Check for explicit anchoring */ + return op == OP_CIRC; +} + +static bool bracketIsAnchored(const unsigned char* code) +{ + do { + if (!branchIsAnchored(code + 1 + LINK_SIZE)) + return false; + code += getLinkValue(code + 1); + } while (*code == OP_ALT); /* Loop for each alternative */ + return true; +} + +/************************************************* +* Check for starting with ^ or .* * +*************************************************/ + +/* This is called to find out if every branch starts with ^ or .* so that +"first char" processing can be done to speed things up in multiline +matching and for non-DOTALL patterns that start with .* (which must start at +the beginning or after \n) + +Except when the .* appears inside capturing parentheses, and there is a +subsequent back reference to those parentheses. By keeping a bitmap of the +first 31 back references, we can catch some of the more common cases more +precisely; all the greater back references share a single bit. + +Arguments: + code points to start of expression (the bracket) + captureMap a bitmap of which brackets we are inside while testing; this + handles up to substring 31; all brackets after that share + the zero bit + backrefMap the back reference bitmap +*/ + +static bool branchNeedsLineStart(const unsigned char* code, unsigned captureMap, unsigned backrefMap) +{ + const unsigned char* scode = firstSignificantOpcode(code); + int op = *scode; + + /* Capturing brackets */ + if (op > OP_BRA) { + int captureNum = op - OP_BRA; + if (captureNum > EXTRACT_BASIC_MAX) + captureNum = get2ByteValue(scode + 2 + LINK_SIZE); + int bracketMask = (captureNum < 32) ? (1 << captureNum) : 1; + return bracketNeedsLineStart(scode, captureMap | bracketMask, backrefMap); + } + + /* Other brackets */ + if (op == OP_BRA || op == OP_ASSERT) + return bracketNeedsLineStart(scode, captureMap, backrefMap); + + /* .* means "start at start or after \n" if it isn't in brackets that + may be referenced. */ + + if (op == OP_TYPESTAR || op == OP_TYPEMINSTAR) + return scode[1] == OP_NOT_NEWLINE && !(captureMap & backrefMap); + + /* Explicit ^ */ + return op == OP_CIRC || op == OP_BOL; +} + +static bool bracketNeedsLineStart(const unsigned char* code, unsigned captureMap, unsigned backrefMap) +{ + do { + if (!branchNeedsLineStart(code + 1 + LINK_SIZE, captureMap, backrefMap)) + return false; + code += getLinkValue(code + 1); + } while (*code == OP_ALT); /* Loop for each alternative */ + return true; +} + +/************************************************* +* Check for asserted fixed first char * +*************************************************/ + +/* During compilation, the "first char" settings from forward assertions are +discarded, because they can cause conflicts with actual literals that follow. +However, if we end up without a first char setting for an unanchored pattern, +it is worth scanning the regex to see if there is an initial asserted first +char. If all branches start with the same asserted char, or with a bracket all +of whose alternatives start with the same asserted 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) + inassert true if in an assertion + +Returns: -1 or the fixed first char +*/ + +static int branchFindFirstAssertedCharacter(const unsigned char* code, bool inassert) +{ + const unsigned char* scode = firstSignificantOpcodeSkippingAssertions(code); + int op = *scode; + + if (op >= OP_BRA) + op = OP_BRA; + + switch (op) { + default: + return -1; + + case OP_BRA: + case OP_ASSERT: + return bracketFindFirstAssertedCharacter(scode, op == OP_ASSERT); + + case OP_EXACT: + scode += 2; + /* Fall through */ + + case OP_CHAR: + case OP_CHAR_IGNORING_CASE: + case OP_ASCII_CHAR: + case OP_ASCII_LETTER_IGNORING_CASE: + case OP_PLUS: + case OP_MINPLUS: + if (!inassert) + return -1; + return scode[1]; + } +} + +static int bracketFindFirstAssertedCharacter(const unsigned char* code, bool inassert) +{ + int c = -1; + do { + int d = branchFindFirstAssertedCharacter(code + 1 + LINK_SIZE, inassert); + if (d < 0) + return -1; + if (c < 0) + c = d; + else if (c != d) + return -1; + code += getLinkValue(code + 1); + } while (*code == OP_ALT); + return c; +} + +static inline int multiplyWithOverflowCheck(int a, int b) +{ + if (!a || !b) + return 0; + if (a > MAX_PATTERN_SIZE / b) + return -1; + return a * b; +} + +static int calculateCompiledPatternLength(const UChar* pattern, int patternLength, JSRegExpIgnoreCaseOption ignoreCase, + CompileData& cd, ErrorCode& errorcode) +{ + /* 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. */ + + if (patternLength > MAX_PATTERN_SIZE) { + errorcode = ERR16; + return -1; + } + + int length = 1 + LINK_SIZE; /* For initial BRA plus length */ + int branch_extra = 0; + int lastitemlength = 0; + unsigned brastackptr = 0; + FixedArray<int, BRASTACK_SIZE> brastack; + FixedArray<unsigned char, BRASTACK_SIZE> bralenstack; + int bracount = 0; + + const UChar* ptr = (const UChar*)(pattern - 1); + const UChar* patternEnd = (const UChar*)(pattern + patternLength); + + while (++ptr < patternEnd) { + int minRepeats = 0, maxRepeats = 0; + int c = *ptr; + + switch (c) { + /* A backslashed item may be an escaped data character or it may be a + character type. */ + + case '\\': + c = checkEscape(&ptr, patternEnd, &errorcode, cd.numCapturingBrackets, false); + if (errorcode != 0) + return -1; + + lastitemlength = 1; /* Default length of last item for repeats */ + + if (c >= 0) { /* Data character */ + length += 2; /* For a one-byte character */ + + if (c > 127) { + int i; + for (i = 0; i < jsc_pcre_utf8_table1_size; i++) + if (c <= jsc_pcre_utf8_table1[i]) break; + length += i; + lastitemlength += i; + } + + continue; + } + + /* Other escapes need one byte */ + + length++; + + /* A back reference needs an additional 2 bytes, 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; + cd.backrefMap |= (refnum < 32) ? (1 << refnum) : 1; + if (refnum > cd.topBackref) + cd.topBackref = refnum; + length += 2; /* For single back reference */ + if (safelyCheckNextChar(ptr, patternEnd, '{') && isCountedRepeat(ptr + 2, patternEnd)) { + ptr = readRepeatCounts(ptr + 2, &minRepeats, &maxRepeats, &errorcode); + if (errorcode) + return -1; + if ((minRepeats == 0 && (maxRepeats == 1 || maxRepeats == -1)) || + (minRepeats == 1 && maxRepeats == -1)) + length++; + else + length += 5; + if (safelyCheckNextChar(ptr, patternEnd, '?')) + ptr++; + } + } + continue; + + case '^': /* Single-byte metacharacters */ + case '.': + case '$': + length++; + lastitemlength = 1; + continue; + + case '*': /* These repeats won't be after brackets; */ + case '+': /* those are handled separately */ + case '?': + length++; + goto POSSESSIVE; + + /* This covers the cases of braced repeats after a single char, metachar, + class, or back reference. */ + + case '{': + if (!isCountedRepeat(ptr + 1, patternEnd)) + goto NORMAL_CHAR; + ptr = readRepeatCounts(ptr + 1, &minRepeats, &maxRepeats, &errorcode); + if (errorcode != 0) + return -1; + + /* These special cases just insert one extra opcode */ + + if ((minRepeats == 0 && (maxRepeats == 1 || maxRepeats == -1)) || + (minRepeats == 1 && maxRepeats == -1)) + length++; + + /* These cases might insert additional copies of a preceding character. */ + + else { + if (minRepeats != 1) { + length -= lastitemlength; /* Uncount the original char or metachar */ + if (minRepeats > 0) + length += 3 + lastitemlength; + } + length += lastitemlength + ((maxRepeats > 0) ? 3 : 1); + } + + if (safelyCheckNextChar(ptr, patternEnd, '?')) + ptr++; /* Needs no extra length */ + + POSSESSIVE: /* Test for possessive quantifier */ + if (safelyCheckNextChar(ptr, patternEnd, '+')) { + ptr++; + length += 2 + 2 * LINK_SIZE; /* Allow for atomic brackets */ + } + 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 '|': + if (brastackptr == 0) + cd.needOuterBracket = true; + length += 1 + LINK_SIZE + branch_extra; + continue; + + /* A character class uses 33 characters provided that all the character + values are less than 256. Otherwise, it uses a bit map for low valued + characters, and individual items for others. 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 single-byte character + uses 2 or 3 bytes, depending on whether it is negated or not. Notice this + where we can. (In UTF-8 mode we can do this only for chars < 128.) */ + + case '[': { + int class_optcount; + if (*(++ptr) == '^') { + class_optcount = 10; /* Greater than one */ + ptr++; + } + else + class_optcount = 0; + + bool class_utf8 = false; + + for (; ptr < patternEnd && *ptr != ']'; ++ptr) { + /* Check for escapes */ + + if (*ptr == '\\') { + c = checkEscape(&ptr, patternEnd, &errorcode, cd.numCapturingBrackets, true); + if (errorcode != 0) + return -1; + + /* Handle escapes that turn into characters */ + + if (c >= 0) + goto NON_SPECIAL_CHARACTER; + + /* Escapes that are meta-things. The normal ones just affect the + bit map, but Unicode properties require an XCLASS extended item. */ + + else + class_optcount = 10; /* \d, \s etc; make sure > 1 */ + } + + /* Anything else increments the possible optimization count. We have to + detect ranges here so that we can compute the number of extra ranges for + caseless wide characters when UCP support is available. If there are wide + characters, we are going to have to use an XCLASS, even for single + characters. */ + + else { + c = *ptr; + + /* Come here from handling \ above when it escapes to a char value */ + + NON_SPECIAL_CHARACTER: + class_optcount++; + + int d = -1; + if (safelyCheckNextChar(ptr, patternEnd, '-')) { + const UChar* hyptr = ptr++; + if (safelyCheckNextChar(ptr, patternEnd, '\\')) { + ptr++; + d = checkEscape(&ptr, patternEnd, &errorcode, cd.numCapturingBrackets, true); + if (errorcode != 0) + return -1; + } + else if ((ptr + 1 < patternEnd) && ptr[1] != ']') + d = *++ptr; + if (d < 0) + ptr = hyptr; /* go back to hyphen as data */ + } + + /* If d >= 0 we have a range. In UTF-8 mode, if the end is > 255, or > + 127 for caseless matching, we will need to use an XCLASS. */ + + if (d >= 0) { + class_optcount = 10; /* Ensure > 1 */ + if (d < c) { + errorcode = ERR8; + return -1; + } + + if ((d > 255 || (ignoreCase && d > 127))) { + unsigned char buffer[6]; + if (!class_utf8) /* Allow for XCLASS overhead */ + { + class_utf8 = true; + length += LINK_SIZE + 2; + } + + /* If we have UCP support, find out how many extra ranges are + needed to map the other case of characters within this range. We + have to mimic the range optimization here, because extending the + range upwards might push d over a boundary that makes it use + another byte in the UTF-8 representation. */ + + if (ignoreCase) { + int occ, ocd; + int cc = c; + int origd = d; + while (getOthercaseRange(&cc, origd, &occ, &ocd)) { + if (occ >= c && ocd <= d) + continue; /* Skip embedded */ + + if (occ < c && ocd >= c - 1) /* Extend the basic range */ + { /* if there is overlap, */ + c = occ; /* noting that if occ < c */ + continue; /* we can't have ocd > d */ + } /* because a subrange is */ + if (ocd > d && occ <= d + 1) /* always shorter than */ + { /* the basic range. */ + d = ocd; + continue; + } + + /* An extra item is needed */ + + length += 1 + encodeUTF8(occ, buffer) + + ((occ == ocd) ? 0 : encodeUTF8(ocd, buffer)); + } + } + + /* The length of the (possibly extended) range */ + + length += 1 + encodeUTF8(c, buffer) + encodeUTF8(d, buffer); + } + + } + + /* We have a single character. There is nothing to be done unless we + are in UTF-8 mode. If the char is > 255, or 127 when caseless, we must + allow for an XCL_SINGLE item, doubled for caselessness if there is UCP + support. */ + + else { + if ((c > 255 || (ignoreCase && c > 127))) { + unsigned char buffer[6]; + class_optcount = 10; /* Ensure > 1 */ + if (!class_utf8) /* Allow for XCLASS overhead */ + { + class_utf8 = true; + length += LINK_SIZE + 2; + } + length += (ignoreCase ? 2 : 1) * (1 + encodeUTF8(c, buffer)); + } + } + } + } + + if (ptr >= patternEnd) { /* Missing terminating ']' */ + errorcode = ERR6; + return -1; + } + + /* We can optimize when there was only one optimizable character. + Note that this does not detect the case of a negated single character. + In that case we do an incorrect length computation, but it's not a serious + problem because the computed length is too large rather than too small. */ + + if (class_optcount == 1) + goto NORMAL_CHAR; + + /* Here, we handle repeats for the class opcodes. */ + { + length += 33; + + /* A repeat needs either 1 or 5 bytes. If it is a possessive quantifier, + we also need extra for wrapping the whole thing in a sub-pattern. */ + + if (safelyCheckNextChar(ptr, patternEnd, '{') && isCountedRepeat(ptr + 2, patternEnd)) { + ptr = readRepeatCounts(ptr + 2, &minRepeats, &maxRepeats, &errorcode); + if (errorcode != 0) + return -1; + if ((minRepeats == 0 && (maxRepeats == 1 || maxRepeats == -1)) || + (minRepeats == 1 && maxRepeats == -1)) + length++; + else + length += 5; + if (safelyCheckNextChar(ptr, patternEnd, '+')) { + ptr++; + length += 2 + 2 * LINK_SIZE; + } else if (safelyCheckNextChar(ptr, patternEnd, '?')) + ptr++; + } + } + continue; + } + + /* Brackets may be genuine groups or special things */ + + case '(': { + int branch_newextra = 0; + int bracket_length = 1 + LINK_SIZE; + bool capturing = false; + + /* Handle special forms of bracket, which all start (? */ + + if (safelyCheckNextChar(ptr, patternEnd, '?')) { + switch (c = (ptr + 2 < patternEnd ? ptr[2] : 0)) { + /* 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 '!': + ptr += 2; + 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: + errorcode = ERR12; + return -1; + } + } else + capturing = 1; + + /* Capturing brackets must be counted so we can process escapes in a + Perlish way. If the number exceeds EXTRACT_BASIC_MAX we are going to need + an additional 3 bytes of memory per capturing bracket. */ + + if (capturing) { + bracount++; + if (bracount > EXTRACT_BASIC_MAX) + bracket_length += 3; + } + + /* 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)) { + errorcode = ERR17; + return -1; + } + + bralenstack[brastackptr] = branch_extra; + branch_extra = branch_newextra; + + brastack[brastackptr++] = length; + length += bracket_length; + continue; + } + + /* Handle ket. Look for subsequent maxRepeats/minRepeats; 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 ')': { + int duplength; + length += 1 + LINK_SIZE; + if (brastackptr > 0) { + duplength = length - brastack[--brastackptr]; + branch_extra = bralenstack[brastackptr]; + } + else + duplength = 0; + + /* Leave ptr at the final char; for readRepeatCounts this happens + automatically; for the others we need an increment. */ + + if ((ptr + 1 < patternEnd) && (c = ptr[1]) == '{' && isCountedRepeat(ptr + 2, patternEnd)) { + ptr = readRepeatCounts(ptr + 2, &minRepeats, &maxRepeats, &errorcode); + if (errorcode) + return -1; + } else if (c == '*') { + minRepeats = 0; + maxRepeats = -1; + ptr++; + } else if (c == '+') { + minRepeats = 1; + maxRepeats = -1; + ptr++; + } else if (c == '?') { + minRepeats = 0; + maxRepeats = 1; + ptr++; + } else { + minRepeats = 1; + maxRepeats = 1; + } + + /* If the minimum is zero, we have to allow for an OP_BRAZERO before the + group, and if the maximum is greater than zero, we have to replicate + maxval-1 times; each replication acquires an OP_BRAZERO plus a nesting + bracket set. */ + + int repeatsLength; + if (minRepeats == 0) { + length++; + if (maxRepeats > 0) { + repeatsLength = multiplyWithOverflowCheck(maxRepeats - 1, duplength + 3 + 2 * LINK_SIZE); + if (repeatsLength < 0) { + errorcode = ERR16; + return -1; + } + length += repeatsLength; + if (length > MAX_PATTERN_SIZE) { + errorcode = ERR16; + return -1; + } + } + } + + /* When the minimum is greater than zero, we have to replicate up to + minval-1 times, with no additions required in the copies. Then, if there + is a limited maximum we have to replicate up to maxval-1 times allowing + for a BRAZERO item before each optional copy and nesting brackets for all + but one of the optional copies. */ + + else { + repeatsLength = multiplyWithOverflowCheck(minRepeats - 1, duplength); + if (repeatsLength < 0) { + errorcode = ERR16; + return -1; + } + length += repeatsLength; + if (maxRepeats > minRepeats) { /* Need this test as maxRepeats=-1 means no limit */ + repeatsLength = multiplyWithOverflowCheck(maxRepeats - minRepeats, duplength + 3 + 2 * LINK_SIZE); + if (repeatsLength < 0) { + errorcode = ERR16; + return -1; + } + length += repeatsLength - (2 + 2 * LINK_SIZE); + } + if (length > MAX_PATTERN_SIZE) { + errorcode = ERR16; + return -1; + } + } + + /* Allow space for once brackets for "possessive quantifier" */ + + if (safelyCheckNextChar(ptr, patternEnd, '+')) { + ptr++; + length += 2 + 2 * LINK_SIZE; + } + continue; + } + + /* Non-special character. It won't be space or # in extended mode, so it is + always a genuine character. If we are in a \Q...\E sequence, check for the + end; if not, we have a literal. */ + + default: + NORMAL_CHAR: + length += 2; /* For a one-byte character */ + lastitemlength = 1; /* Default length of last item for repeats */ + + if (c > 127) { + int i; + for (i = 0; i < jsc_pcre_utf8_table1_size; i++) + if (c <= jsc_pcre_utf8_table1[i]) + break; + length += i; + lastitemlength += i; + } + + continue; + } + } + + length += 2 + LINK_SIZE; /* For final KET and END */ + + cd.numCapturingBrackets = bracount; + return length; +} + +/************************************************* +* 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. The original API for this +function had no error code return variable; it is retained for backwards +compatibility. The new function is given a new name. + +Arguments: + pattern the regular expression + options various option bits + errorCodePtr pointer to error code variable (pcre_compile2() only) + can be NULL if you don't want a code value + errorPtr pointer to pointer to error text + erroroffset ptr offset in pattern where error was detected + tables pointer to character tables or NULL + +Returns: pointer to compiled data block, or NULL on error, + with errorPtr and erroroffset set +*/ + +static inline JSRegExp* returnError(ErrorCode errorcode, const char** errorPtr) +{ + *errorPtr = errorText(errorcode); + return 0; +} + +JSRegExp* jsRegExpCompile(const UChar* pattern, int patternLength, + JSRegExpIgnoreCaseOption ignoreCase, JSRegExpMultilineOption multiline, + unsigned* numSubpatterns, const char** errorPtr) +{ + /* We can't pass back an error message if errorPtr is NULL; I guess the best we + can do is just return NULL, but we can set a code value if there is a code pointer. */ + if (!errorPtr) + return 0; + *errorPtr = NULL; + + CompileData cd; + + ErrorCode errorcode = ERR0; + /* Call this once just to count the brackets. */ + calculateCompiledPatternLength(pattern, patternLength, ignoreCase, cd, errorcode); + /* Call it again to compute the length. */ + int length = calculateCompiledPatternLength(pattern, patternLength, ignoreCase, cd, errorcode); + if (errorcode) + return returnError(errorcode, errorPtr); + + if (length > MAX_PATTERN_SIZE) + return returnError(ERR16, errorPtr); + + size_t size = length + sizeof(JSRegExp); +#if REGEXP_HISTOGRAM + size_t stringOffset = (size + sizeof(UChar) - 1) / sizeof(UChar) * sizeof(UChar); + size = stringOffset + patternLength * sizeof(UChar); +#endif + JSRegExp* re = reinterpret_cast_ptr<JSRegExp*>(new char[size]); + + if (!re) + return returnError(ERR13, errorPtr); + + re->options = (ignoreCase ? IgnoreCaseOption : 0) | (multiline ? MatchAcrossMultipleLinesOption : 0); + + /* The starting points of the name/number translation table and of the code are + passed around in the compile data block. */ + + const unsigned char* codeStart = (const unsigned char*)(re + 1); + + /* Set up a starting, non-extracting bracket, then compile the expression. On + error, errorcode will be set non-zero, so we don't need to look at the result + of the function here. */ + + const UChar* ptr = (const UChar*)pattern; + const UChar* patternEnd = pattern + patternLength; + unsigned char* code = const_cast<unsigned char*>(codeStart); + int firstByte, reqByte; + int bracketCount = 0; + if (!cd.needOuterBracket) + compileBranch(re->options, &bracketCount, &code, &ptr, patternEnd, &errorcode, &firstByte, &reqByte, cd); + else { + *code = OP_BRA; + compileBracket(re->options, &bracketCount, &code, &ptr, patternEnd, &errorcode, 0, &firstByte, &reqByte, cd); + } + re->topBracket = bracketCount; + re->topBackref = cd.topBackref; + + /* If not reached end of pattern on success, there's an excess bracket. */ + + if (errorcode == 0 && ptr < patternEnd) + errorcode = ERR10; + + /* 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; + + ASSERT(code - codeStart <= length); + if (code - codeStart > length) + errorcode = ERR7; + + /* Give an error if there's back reference to a non-existent capturing + subpattern. */ + + if (re->topBackref > re->topBracket) + errorcode = ERR15; + + /* Failed to compile, or error while post-processing */ + + if (errorcode != ERR0) { + delete [] reinterpret_cast<char*>(re); + return returnError(errorcode, errorPtr); + } + + /* If the anchored option was not passed, set the flag if we can determine that + the pattern is anchored by virtue of ^ characters or \A or anything else (such + as starting with .* when DOTALL is set). + + Otherwise, if we know what the first character has to be, save it, because that + speeds up unanchored matches no end. If not, see if we can set the + UseMultiLineFirstByteOptimizationOption flag. This is helpful for multiline matches when all branches + start with ^. and also when all branches start with .* for non-DOTALL matches. + */ + + if (cd.needOuterBracket ? bracketIsAnchored(codeStart) : branchIsAnchored(codeStart)) + re->options |= IsAnchoredOption; + else { + if (firstByte < 0) { + firstByte = (cd.needOuterBracket + ? bracketFindFirstAssertedCharacter(codeStart, false) + : branchFindFirstAssertedCharacter(codeStart, false)) + | ((re->options & IgnoreCaseOption) ? REQ_IGNORE_CASE : 0); + } + if (firstByte >= 0) { + int ch = firstByte & 255; + if (ch < 127) { + re->firstByte = ((firstByte & REQ_IGNORE_CASE) && flipCase(ch) == ch) ? ch : firstByte; + re->options |= UseFirstByteOptimizationOption; + } + } else { + if (cd.needOuterBracket ? bracketNeedsLineStart(codeStart, 0, cd.backrefMap) : branchNeedsLineStart(codeStart, 0, cd.backrefMap)) + re->options |= UseMultiLineFirstByteOptimizationOption; + } + } + + /* For an anchored pattern, we use the "required byte" only if it follows a + variable length item in the regex. Remove the caseless flag for non-caseable + bytes. */ + + if (reqByte >= 0 && (!(re->options & IsAnchoredOption) || (reqByte & REQ_VARY))) { + int ch = reqByte & 255; + if (ch < 127) { + re->reqByte = ((reqByte & REQ_IGNORE_CASE) && flipCase(ch) == ch) ? (reqByte & ~REQ_IGNORE_CASE) : reqByte; + re->options |= UseRequiredByteOptimizationOption; + } + } + +#if REGEXP_HISTOGRAM + re->stringOffset = stringOffset; + re->stringLength = patternLength; + memcpy(reinterpret_cast<char*>(re) + stringOffset, pattern, patternLength * 2); +#endif + + if (numSubpatterns) + *numSubpatterns = re->topBracket; + return re; +} + +void jsRegExpFree(JSRegExp* re) +{ + delete [] reinterpret_cast<char*>(re); +} |