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      1 /* This is JavaScriptCore's variant of the PCRE library. While this library
      2 started out as a copy of PCRE, many of the features of PCRE have been
      3 removed. This library now supports only the regular expression features
      4 required by the JavaScript language specification, and has only the functions
      5 needed by JavaScriptCore and the rest of WebKit.
      6 
      7                  Originally written by Philip Hazel
      8            Copyright (c) 1997-2006 University of Cambridge
      9     Copyright (C) 2002, 2004, 2006, 2007, 2008, 2009 Apple Inc. All rights reserved.
     10 
     11 -----------------------------------------------------------------------------
     12 Redistribution and use in source and binary forms, with or without
     13 modification, are permitted provided that the following conditions are met:
     14 
     15     * Redistributions of source code must retain the above copyright notice,
     16       this list of conditions and the following disclaimer.
     17 
     18     * Redistributions in binary form must reproduce the above copyright
     19       notice, this list of conditions and the following disclaimer in the
     20       documentation and/or other materials provided with the distribution.
     21 
     22     * Neither the name of the University of Cambridge nor the names of its
     23       contributors may be used to endorse or promote products derived from
     24       this software without specific prior written permission.
     25 
     26 THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
     27 AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28 IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29 ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
     30 LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31 CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32 SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33 INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34 CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35 ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36 POSSIBILITY OF SUCH DAMAGE.
     37 -----------------------------------------------------------------------------
     38 */
     39 
     40 /* This header contains definitions that are shared between the different
     41 modules, but which are not relevant to the exported API. This includes some
     42 functions whose names all begin with "_pcre_". */
     43 
     44 #ifndef PCRE_INTERNAL_H
     45 #define PCRE_INTERNAL_H
     46 
     47 /* Bit definitions for entries in the pcre_ctypes table. */
     48 
     49 #define ctype_space   0x01
     50 #define ctype_xdigit  0x08
     51 #define ctype_word    0x10   /* alphameric or '_' */
     52 
     53 /* Offsets for the bitmap tables in pcre_cbits. Each table contains a set
     54 of bits for a class map. Some classes are built by combining these tables. */
     55 
     56 #define cbit_space     0      /* \s */
     57 #define cbit_digit    32      /* \d */
     58 #define cbit_word     64      /* \w */
     59 #define cbit_length   96      /* Length of the cbits table */
     60 
     61 /* Offsets of the various tables from the base tables pointer, and
     62 total length. */
     63 
     64 #define lcc_offset      0
     65 #define fcc_offset    128
     66 #define cbits_offset  256
     67 #define ctypes_offset (cbits_offset + cbit_length)
     68 #define tables_length (ctypes_offset + 128)
     69 
     70 #ifndef DFTABLES
     71 
     72 // Change the following to 1 to dump used regular expressions at process exit time.
     73 #define REGEXP_HISTOGRAM 0
     74 
     75 #include "Assertions.h"
     76 
     77 #if COMPILER(MSVC)
     78 #pragma warning(disable: 4232)
     79 #pragma warning(disable: 4244)
     80 #endif
     81 
     82 #include "pcre.h"
     83 
     84 /* The value of LINK_SIZE determines the number of bytes used to store links as
     85 offsets within the compiled regex. The default is 2, which allows for compiled
     86 patterns up to 64K long. */
     87 
     88 #define LINK_SIZE   3
     89 
     90 /* Define DEBUG to get debugging output on stdout. */
     91 
     92 #if 0
     93 #define DEBUG
     94 #endif
     95 
     96 /* Use a macro for debugging printing, 'cause that eliminates the use of #ifdef
     97 inline, and there are *still* stupid compilers about that don't like indented
     98 pre-processor statements, or at least there were when I first wrote this. After
     99 all, it had only been about 10 years then... */
    100 
    101 #ifdef DEBUG
    102 #define DPRINTF(p) printf p
    103 #else
    104 #define DPRINTF(p) /*nothing*/
    105 #endif
    106 
    107 /* PCRE keeps offsets in its compiled code as 2-byte quantities (always stored
    108 in big-endian order) by default. These are used, for example, to link from the
    109 start of a subpattern to its alternatives and its end. The use of 2 bytes per
    110 offset limits the size of the compiled regex to around 64K, which is big enough
    111 for almost everybody. However, I received a request for an even bigger limit.
    112 For this reason, and also to make the code easier to maintain, the storing and
    113 loading of offsets from the byte string is now handled by the functions that are
    114 defined here. */
    115 
    116 /* PCRE uses some other 2-byte quantities that do not change when the size of
    117 offsets changes. There are used for repeat counts and for other things such as
    118 capturing parenthesis numbers in back references. */
    119 
    120 static inline void put2ByteValue(unsigned char* opcodePtr, int value)
    121 {
    122     ASSERT(value >= 0 && value <= 0xFFFF);
    123     opcodePtr[0] = value >> 8;
    124     opcodePtr[1] = value;
    125 }
    126 
    127 static inline void put3ByteValue(unsigned char* opcodePtr, int value)
    128 {
    129     ASSERT(value >= 0 && value <= 0xFFFFFF);
    130     opcodePtr[0] = value >> 16;
    131     opcodePtr[1] = value >> 8;
    132     opcodePtr[2] = value;
    133 }
    134 
    135 static inline int get2ByteValue(const unsigned char* opcodePtr)
    136 {
    137     return (opcodePtr[0] << 8) | opcodePtr[1];
    138 }
    139 
    140 static inline int get3ByteValue(const unsigned char* opcodePtr)
    141 {
    142     return (opcodePtr[0] << 16) | (opcodePtr[1] << 8) | opcodePtr[2];
    143 }
    144 
    145 static inline void put2ByteValueAndAdvance(unsigned char*& opcodePtr, int value)
    146 {
    147     put2ByteValue(opcodePtr, value);
    148     opcodePtr += 2;
    149 }
    150 
    151 static inline void put3ByteValueAndAdvance(unsigned char*& opcodePtr, int value)
    152 {
    153     put3ByteValue(opcodePtr, value);
    154     opcodePtr += 3;
    155 }
    156 
    157 static inline void putLinkValueAllowZero(unsigned char* opcodePtr, int value)
    158 {
    159 #if LINK_SIZE == 3
    160     put3ByteValue(opcodePtr, value);
    161 #elif LINK_SIZE == 2
    162     put2ByteValue(opcodePtr, value);
    163 #else
    164 #   error LINK_SIZE not supported.
    165 #endif
    166 }
    167 
    168 static inline int getLinkValueAllowZero(const unsigned char* opcodePtr)
    169 {
    170 #if LINK_SIZE == 3
    171     return get3ByteValue(opcodePtr);
    172 #elif LINK_SIZE == 2
    173     return get2ByteValue(opcodePtr);
    174 #else
    175 #   error LINK_SIZE not supported.
    176 #endif
    177 }
    178 
    179 #define MAX_PATTERN_SIZE 1024 * 1024 // Derived by empirical testing of compile time in PCRE and WREC.
    180 COMPILE_ASSERT(MAX_PATTERN_SIZE < (1 << (8 * LINK_SIZE)), pcre_max_pattern_fits_in_bytecode);
    181 
    182 static inline void putLinkValue(unsigned char* opcodePtr, int value)
    183 {
    184     ASSERT(value);
    185     putLinkValueAllowZero(opcodePtr, value);
    186 }
    187 
    188 static inline int getLinkValue(const unsigned char* opcodePtr)
    189 {
    190     int value = getLinkValueAllowZero(opcodePtr);
    191     ASSERT(value);
    192     return value;
    193 }
    194 
    195 static inline void putLinkValueAndAdvance(unsigned char*& opcodePtr, int value)
    196 {
    197     putLinkValue(opcodePtr, value);
    198     opcodePtr += LINK_SIZE;
    199 }
    200 
    201 static inline void putLinkValueAllowZeroAndAdvance(unsigned char*& opcodePtr, int value)
    202 {
    203     putLinkValueAllowZero(opcodePtr, value);
    204     opcodePtr += LINK_SIZE;
    205 }
    206 
    207 // FIXME: These are really more of a "compiled regexp state" than "regexp options"
    208 enum RegExpOptions {
    209     UseFirstByteOptimizationOption = 0x40000000,  /* firstByte is set */
    210     UseRequiredByteOptimizationOption = 0x20000000,  /* reqByte is set */
    211     UseMultiLineFirstByteOptimizationOption = 0x10000000,  /* start after \n for multiline */
    212     IsAnchoredOption = 0x02000000,  /* can't use partial with this regex */
    213     IgnoreCaseOption = 0x00000001,
    214     MatchAcrossMultipleLinesOption = 0x00000002
    215 };
    216 
    217 /* Flags added to firstByte or reqByte; a "non-literal" item is either a
    218 variable-length repeat, or a anything other than literal characters. */
    219 
    220 #define REQ_IGNORE_CASE 0x0100    /* indicates should ignore case */
    221 #define REQ_VARY     0x0200    /* reqByte followed non-literal item */
    222 
    223 /* Miscellaneous definitions */
    224 
    225 /* Flag bits and data types for the extended class (OP_XCLASS) for classes that
    226 contain UTF-8 characters with values greater than 255. */
    227 
    228 #define XCL_NOT    0x01    /* Flag: this is a negative class */
    229 #define XCL_MAP    0x02    /* Flag: a 32-byte map is present */
    230 
    231 #define XCL_END       0    /* Marks end of individual items */
    232 #define XCL_SINGLE    1    /* Single item (one multibyte char) follows */
    233 #define XCL_RANGE     2    /* A range (two multibyte chars) follows */
    234 
    235 /* These are escaped items that aren't just an encoding of a particular data
    236 value such as \n. They must have non-zero values, as check_escape() returns
    237 their negation. Also, they must appear in the same order as in the opcode
    238 definitions below, up to ESC_w. The final one must be
    239 ESC_REF as subsequent values are used for \1, \2, \3, etc. There is are two
    240 tests in the code for an escape > ESC_b and <= ESC_w to
    241 detect the types that may be repeated. These are the types that consume
    242 characters. If any new escapes are put in between that don't consume a
    243 character, that code will have to change. */
    244 
    245 enum { ESC_B = 1, ESC_b, ESC_D, ESC_d, ESC_S, ESC_s, ESC_W, ESC_w, ESC_REF };
    246 
    247 /* Opcode table: OP_BRA must be last, as all values >= it are used for brackets
    248 that extract substrings. Starting from 1 (i.e. after OP_END), the values up to
    249 OP_EOD must correspond in order to the list of escapes immediately above.
    250 Note that whenever this list is updated, the two macro definitions that follow
    251 must also be updated to match. */
    252 
    253 #define FOR_EACH_OPCODE(macro) \
    254     macro(END) \
    255     \
    256     macro(NOT_WORD_BOUNDARY) \
    257     macro(WORD_BOUNDARY) \
    258     macro(NOT_DIGIT) \
    259     macro(DIGIT) \
    260     macro(NOT_WHITESPACE) \
    261     macro(WHITESPACE) \
    262     macro(NOT_WORDCHAR) \
    263     macro(WORDCHAR) \
    264     \
    265     macro(NOT_NEWLINE) \
    266     \
    267     macro(CIRC) \
    268     macro(DOLL) \
    269     macro(BOL) \
    270     macro(EOL) \
    271     macro(CHAR) \
    272     macro(CHAR_IGNORING_CASE) \
    273     macro(ASCII_CHAR) \
    274     macro(ASCII_LETTER_IGNORING_CASE) \
    275     macro(NOT) \
    276     \
    277     macro(STAR) \
    278     macro(MINSTAR) \
    279     macro(PLUS) \
    280     macro(MINPLUS) \
    281     macro(QUERY) \
    282     macro(MINQUERY) \
    283     macro(UPTO) \
    284     macro(MINUPTO) \
    285     macro(EXACT) \
    286     \
    287     macro(NOTSTAR) \
    288     macro(NOTMINSTAR) \
    289     macro(NOTPLUS) \
    290     macro(NOTMINPLUS) \
    291     macro(NOTQUERY) \
    292     macro(NOTMINQUERY) \
    293     macro(NOTUPTO) \
    294     macro(NOTMINUPTO) \
    295     macro(NOTEXACT) \
    296     \
    297     macro(TYPESTAR) \
    298     macro(TYPEMINSTAR) \
    299     macro(TYPEPLUS) \
    300     macro(TYPEMINPLUS) \
    301     macro(TYPEQUERY) \
    302     macro(TYPEMINQUERY) \
    303     macro(TYPEUPTO) \
    304     macro(TYPEMINUPTO) \
    305     macro(TYPEEXACT) \
    306     \
    307     macro(CRSTAR) \
    308     macro(CRMINSTAR) \
    309     macro(CRPLUS) \
    310     macro(CRMINPLUS) \
    311     macro(CRQUERY) \
    312     macro(CRMINQUERY) \
    313     macro(CRRANGE) \
    314     macro(CRMINRANGE) \
    315     \
    316     macro(CLASS) \
    317     macro(NCLASS) \
    318     macro(XCLASS) \
    319     \
    320     macro(REF) \
    321     \
    322     macro(ALT) \
    323     macro(KET) \
    324     macro(KETRMAX) \
    325     macro(KETRMIN) \
    326     \
    327     macro(ASSERT) \
    328     macro(ASSERT_NOT) \
    329     \
    330     macro(BRAZERO) \
    331     macro(BRAMINZERO) \
    332     macro(BRANUMBER) \
    333     macro(BRA)
    334 
    335 #define OPCODE_ENUM_VALUE(opcode) OP_##opcode,
    336 enum { FOR_EACH_OPCODE(OPCODE_ENUM_VALUE) };
    337 
    338 /* WARNING WARNING WARNING: There is an implicit assumption in pcre.c and
    339 study.c that all opcodes are less than 128 in value. This makes handling UTF-8
    340 character sequences easier. */
    341 
    342 /* The highest extraction number before we have to start using additional
    343 bytes. (Originally PCRE didn't have support for extraction counts higher than
    344 this number.) The value is limited by the number of opcodes left after OP_BRA,
    345 i.e. 255 - OP_BRA. We actually set it a bit lower to leave room for additional
    346 opcodes. */
    347 
    348 /* FIXME: Note that OP_BRA + 100 is > 128, so the two comments above
    349 are in conflict! */
    350 
    351 #define EXTRACT_BASIC_MAX  100
    352 
    353 /* The code vector runs on as long as necessary after the end. */
    354 
    355 struct JSRegExp {
    356     unsigned options;
    357 
    358     unsigned short topBracket;
    359     unsigned short topBackref;
    360 
    361     unsigned short firstByte;
    362     unsigned short reqByte;
    363 
    364 #if REGEXP_HISTOGRAM
    365     size_t stringOffset;
    366     size_t stringLength;
    367 #endif
    368 };
    369 
    370 /* Internal shared data tables. These are tables that are used by more than one
    371  of the exported public functions. They have to be "external" in the C sense,
    372  but are not part of the PCRE public API. The data for these tables is in the
    373  pcre_tables.c module. */
    374 
    375 #define jsc_pcre_utf8_table1_size 6
    376 
    377 extern const int    jsc_pcre_utf8_table1[6];
    378 extern const int    jsc_pcre_utf8_table2[6];
    379 extern const int    jsc_pcre_utf8_table3[6];
    380 extern const unsigned char jsc_pcre_utf8_table4[0x40];
    381 
    382 extern const unsigned char jsc_pcre_default_tables[tables_length];
    383 
    384 static inline unsigned char toLowerCase(unsigned char c)
    385 {
    386     static const unsigned char* lowerCaseChars = jsc_pcre_default_tables + lcc_offset;
    387     return lowerCaseChars[c];
    388 }
    389 
    390 static inline unsigned char flipCase(unsigned char c)
    391 {
    392     static const unsigned char* flippedCaseChars = jsc_pcre_default_tables + fcc_offset;
    393     return flippedCaseChars[c];
    394 }
    395 
    396 static inline unsigned char classBitmapForChar(unsigned char c)
    397 {
    398     static const unsigned char* charClassBitmaps = jsc_pcre_default_tables + cbits_offset;
    399     return charClassBitmaps[c];
    400 }
    401 
    402 static inline unsigned char charTypeForChar(unsigned char c)
    403 {
    404     const unsigned char* charTypeMap = jsc_pcre_default_tables + ctypes_offset;
    405     return charTypeMap[c];
    406 }
    407 
    408 static inline bool isWordChar(UChar c)
    409 {
    410     return c < 128 && (charTypeForChar(c) & ctype_word);
    411 }
    412 
    413 static inline bool isSpaceChar(UChar c)
    414 {
    415     return (c < 128 && (charTypeForChar(c) & ctype_space)) || c == 0x00A0;
    416 }
    417 
    418 static inline bool isNewline(UChar nl)
    419 {
    420     return (nl == 0xA || nl == 0xD || nl == 0x2028 || nl == 0x2029);
    421 }
    422 
    423 static inline bool isBracketStartOpcode(unsigned char opcode)
    424 {
    425     if (opcode >= OP_BRA)
    426         return true;
    427     switch (opcode) {
    428         case OP_ASSERT:
    429         case OP_ASSERT_NOT:
    430             return true;
    431         default:
    432             return false;
    433     }
    434 }
    435 
    436 static inline void advanceToEndOfBracket(const unsigned char*& opcodePtr)
    437 {
    438     ASSERT(isBracketStartOpcode(*opcodePtr) || *opcodePtr == OP_ALT);
    439     do
    440         opcodePtr += getLinkValue(opcodePtr + 1);
    441     while (*opcodePtr == OP_ALT);
    442 }
    443 
    444 /* Internal shared functions. These are functions that are used in more
    445 that one of the source files. They have to have external linkage, but
    446 but are not part of the public API and so not exported from the library. */
    447 
    448 extern int jsc_pcre_ucp_othercase(unsigned);
    449 extern bool jsc_pcre_xclass(int, const unsigned char*);
    450 
    451 #endif
    452 
    453 #endif
    454 
    455 /* End of pcre_internal.h */
    456