JavaScriptCore/pcre/pcre_internal.h
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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 */