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      1 //
      2 //   Copyright (C) 2002-2012 International Business Machines Corporation
      3 //   and others. All rights reserved.
      4 //
      5 //   file:  regeximp.h
      6 //
      7 //           ICU Regular Expressions,
      8 //               Definitions of constant values used in the compiled form of
      9 //               a regular expression pattern.
     10 //
     11 
     12 #ifndef _REGEXIMP_H
     13 #define _REGEXIMP_H
     14 
     15 #include "unicode/utypes.h"
     16 #include "unicode/uobject.h"
     17 #include "unicode/uniset.h"
     18 #include "unicode/utext.h"
     19 
     20 #include "cmemory.h"
     21 #include "ucase.h"
     22 
     23 U_NAMESPACE_BEGIN
     24 
     25 // For debugging, define REGEX_DEBUG
     26 // To define with configure,
     27 //   ./runConfigureICU --enable-debug --disable-release Linux CPPFLAGS="-DREGEX_DEBUG"
     28 
     29 #ifdef REGEX_DEBUG
     30 //
     31 //  debugging options.  Enable one or more of the three #defines immediately following
     32 //
     33 
     34 //#define REGEX_SCAN_DEBUG
     35 #define REGEX_DUMP_DEBUG
     36 #define REGEX_RUN_DEBUG
     37 
     38 //  End of #defines inteded to be directly set.
     39 
     40 #include <stdio.h>
     41 #endif
     42 
     43 #ifdef REGEX_SCAN_DEBUG
     44 #define REGEX_SCAN_DEBUG_PRINTF(a) printf a
     45 #else
     46 #define REGEX_SCAN_DEBUG_PRINTF(a)
     47 #endif
     48 
     49 #ifdef REGEX_DUMP_DEBUG
     50 #define REGEX_DUMP_DEBUG_PRINTF(a) printf a
     51 #else
     52 #define REGEX_DUMP_DEBUG_PRINTF(a)
     53 #endif
     54 
     55 #ifdef REGEX_RUN_DEBUG
     56 #define REGEX_RUN_DEBUG_PRINTF(a) printf a
     57 #define REGEX_DUMP_DEBUG_PRINTF(a) printf a
     58 #else
     59 #define REGEX_RUN_DEBUG_PRINTF(a)
     60 #endif
     61 
     62 
     63 //
     64 //  Opcode types     In the compiled form of the regexp, these are the type, or opcodes,
     65 //                   of the entries.
     66 //
     67 enum {
     68      URX_RESERVED_OP   = 0,    // For multi-operand ops, most non-first words.
     69      URX_RESERVED_OP_N = 255,  // For multi-operand ops, negative operand values.
     70      URX_BACKTRACK     = 1,    // Force a backtrack, as if a match test had failed.
     71      URX_END           = 2,
     72      URX_ONECHAR       = 3,    // Value field is the 21 bit unicode char to match
     73      URX_STRING        = 4,    // Value field is index of string start
     74      URX_STRING_LEN    = 5,    // Value field is string length (code units)
     75      URX_STATE_SAVE    = 6,    // Value field is pattern position to push
     76      URX_NOP           = 7,
     77      URX_START_CAPTURE = 8,    // Value field is capture group number.
     78      URX_END_CAPTURE   = 9,    // Value field is capture group number
     79      URX_STATIC_SETREF = 10,   // Value field is index of set in array of sets.
     80      URX_SETREF        = 11,   // Value field is index of set in array of sets.
     81      URX_DOTANY        = 12,
     82      URX_JMP           = 13,   // Value field is destination position in
     83                                                     //   the pattern.
     84      URX_FAIL          = 14,   // Stop match operation,  No match.
     85 
     86      URX_JMP_SAV       = 15,   // Operand:  JMP destination location
     87      URX_BACKSLASH_B   = 16,   // Value field:  0:  \b    1:  \B
     88      URX_BACKSLASH_G   = 17,
     89      URX_JMP_SAV_X     = 18,   // Conditional JMP_SAV,
     90                                //    Used in (x)+, breaks loop on zero length match.
     91                                //    Operand:  Jmp destination.
     92      URX_BACKSLASH_X   = 19,
     93      URX_BACKSLASH_Z   = 20,   // \z   Unconditional end of line.
     94 
     95      URX_DOTANY_ALL    = 21,   // ., in the . matches any mode.
     96      URX_BACKSLASH_D   = 22,   // Value field:  0:  \d    1:  \D
     97      URX_CARET         = 23,   // Value field:  1:  multi-line mode.
     98      URX_DOLLAR        = 24,  // Also for \Z
     99 
    100      URX_CTR_INIT      = 25,   // Counter Inits for {Interval} loops.
    101      URX_CTR_INIT_NG   = 26,   //   2 kinds, normal and non-greedy.
    102                                //   These are 4 word opcodes.  See description.
    103                                //    First Operand:  Data loc of counter variable
    104                                //    2nd   Operand:  Pat loc of the URX_CTR_LOOPx
    105                                //                    at the end of the loop.
    106                                //    3rd   Operand:  Minimum count.
    107                                //    4th   Operand:  Max count, -1 for unbounded.
    108 
    109      URX_DOTANY_UNIX   = 27,   // '.' operator in UNIX_LINES mode, only \n marks end of line.
    110 
    111      URX_CTR_LOOP      = 28,   // Loop Ops for {interval} loops.
    112      URX_CTR_LOOP_NG   = 29,   //   Also in three flavors.
    113                                //   Operand is loc of corresponding CTR_INIT.
    114 
    115      URX_CARET_M_UNIX  = 30,   // '^' operator, test for start of line in multi-line
    116                                //      plus UNIX_LINES mode.
    117 
    118      URX_RELOC_OPRND   = 31,   // Operand value in multi-operand ops that refers
    119                                //   back into compiled pattern code, and thus must
    120                                //   be relocated when inserting/deleting ops in code.
    121 
    122      URX_STO_SP        = 32,   // Store the stack ptr.  Operand is location within
    123                                //   matcher data (not stack data) to store it.
    124      URX_LD_SP         = 33,   // Load the stack pointer.  Operand is location
    125                                //   to load from.
    126      URX_BACKREF       = 34,   // Back Reference.  Parameter is the index of the
    127                                //   capture group variables in the state stack frame.
    128      URX_STO_INP_LOC   = 35,   // Store the input location.  Operand is location
    129                                //   within the matcher stack frame.
    130      URX_JMPX          = 36,  // Conditional JMP.
    131                                //   First Operand:  JMP target location.
    132                                //   Second Operand:  Data location containing an
    133                                //     input position.  If current input position ==
    134                                //     saved input position, FAIL rather than taking
    135                                //     the JMP
    136      URX_LA_START      = 37,   // Starting a LookAround expression.
    137                                //   Save InputPos and SP in static data.
    138                                //   Operand:  Static data offset for the save
    139      URX_LA_END        = 38,   // Ending a Lookaround expression.
    140                                //   Restore InputPos and Stack to saved values.
    141                                //   Operand:  Static data offset for saved data.
    142      URX_ONECHAR_I     = 39,   // Test for case-insensitive match of a literal character.
    143                                //   Operand:  the literal char.
    144      URX_STRING_I      = 40,   // Case insensitive string compare.
    145                                //   First Operand:  Index of start of string in string literals
    146                                //   Second Operand (next word in compiled code):
    147                                //     the length of the string.
    148      URX_BACKREF_I     = 41,   // Case insensitive back reference.
    149                                //   Parameter is the index of the
    150                                //   capture group variables in the state stack frame.
    151      URX_DOLLAR_M      = 42,   // $ in multi-line mode.
    152      URX_CARET_M       = 43,   // ^ in multi-line mode.
    153      URX_LB_START      = 44,   // LookBehind Start.
    154                                //   Paramater is data location
    155      URX_LB_CONT       = 45,   // LookBehind Continue.
    156                                //   Param 0:  the data location
    157                                //   Param 1:  The minimum length of the look-behind match
    158                                //   Param 2:  The max length of the look-behind match
    159      URX_LB_END        = 46,   // LookBehind End.
    160                                //   Parameter is the data location.
    161                                //     Check that match ended at the right spot,
    162                                //     Restore original input string len.
    163      URX_LBN_CONT      = 47,   // Negative LookBehind Continue
    164                                //   Param 0:  the data location
    165                                //   Param 1:  The minimum length of the look-behind match
    166                                //   Param 2:  The max     length of the look-behind match
    167                                //   Param 3:  The pattern loc following the look-behind block.
    168      URX_LBN_END       = 48,   // Negative LookBehind end
    169                                //   Parameter is the data location.
    170                                //   Check that the match ended at the right spot.
    171      URX_STAT_SETREF_N = 49,   // Reference to a prebuilt set (e.g. \w), negated
    172                                //   Operand is index of set in array of sets.
    173      URX_LOOP_SR_I     = 50,   // Init a [set]* loop.
    174                                //   Operand is the sets index in array of user sets.
    175      URX_LOOP_C        = 51,   // Continue a [set]* or OneChar* loop.
    176                                //   Operand is a matcher static data location.
    177                                //   Must always immediately follow  LOOP_x_I instruction.
    178      URX_LOOP_DOT_I    = 52,   // .*, initialization of the optimized loop.
    179                                //   Operand value:
    180                                //      bit 0:
    181                                //         0:  Normal (. doesn't match new-line) mode.
    182                                //         1:  . matches new-line mode.
    183                                //      bit 1:  controls what new-lines are recognized by this operation.
    184                                //         0:  All Unicode New-lines
    185                                //         1:  UNIX_LINES, \u000a only.
    186      URX_BACKSLASH_BU  = 53,   // \b or \B in UREGEX_UWORD mode, using Unicode style
    187                                //   word boundaries.
    188      URX_DOLLAR_D      = 54,   // $ end of input test, in UNIX_LINES mode.
    189      URX_DOLLAR_MD     = 55    // $ end of input test, in MULTI_LINE and UNIX_LINES mode.
    190 
    191 };
    192 
    193 // Keep this list of opcode names in sync with the above enum
    194 //   Used for debug printing only.
    195 #define URX_OPCODE_NAMES       \
    196         "               ",     \
    197         "BACKTRACK",           \
    198         "END",                 \
    199         "ONECHAR",             \
    200         "STRING",              \
    201         "STRING_LEN",          \
    202         "STATE_SAVE",          \
    203         "NOP",                 \
    204         "START_CAPTURE",       \
    205         "END_CAPTURE",         \
    206         "URX_STATIC_SETREF",   \
    207         "SETREF",              \
    208         "DOTANY",              \
    209         "JMP",                 \
    210         "FAIL",                \
    211         "JMP_SAV",             \
    212         "BACKSLASH_B",         \
    213         "BACKSLASH_G",         \
    214         "JMP_SAV_X",           \
    215         "BACKSLASH_X",         \
    216         "BACKSLASH_Z",         \
    217         "DOTANY_ALL",          \
    218         "BACKSLASH_D",         \
    219         "CARET",               \
    220         "DOLLAR",              \
    221         "CTR_INIT",            \
    222         "CTR_INIT_NG",         \
    223         "DOTANY_UNIX",         \
    224         "CTR_LOOP",            \
    225         "CTR_LOOP_NG",         \
    226         "URX_CARET_M_UNIX",    \
    227         "RELOC_OPRND",         \
    228         "STO_SP",              \
    229         "LD_SP",               \
    230         "BACKREF",             \
    231         "STO_INP_LOC",         \
    232         "JMPX",                \
    233         "LA_START",            \
    234         "LA_END",              \
    235         "ONECHAR_I",           \
    236         "STRING_I",            \
    237         "BACKREF_I",           \
    238         "DOLLAR_M",            \
    239         "CARET_M",             \
    240         "LB_START",            \
    241         "LB_CONT",             \
    242         "LB_END",              \
    243         "LBN_CONT",            \
    244         "LBN_END",             \
    245         "STAT_SETREF_N",       \
    246         "LOOP_SR_I",           \
    247         "LOOP_C",              \
    248         "LOOP_DOT_I",          \
    249         "BACKSLASH_BU",        \
    250         "DOLLAR_D",            \
    251         "DOLLAR_MD"
    252 
    253 
    254 //
    255 //  Convenience macros for assembling and disassembling a compiled operation.
    256 //
    257 #define URX_BUILD(type, val) (int32_t)((type << 24) | (val))
    258 #define URX_TYPE(x)          ((uint32_t)(x) >> 24)
    259 #define URX_VAL(x)           ((x) & 0xffffff)
    260 
    261 
    262 //
    263 //  Access to Unicode Sets composite character properties
    264 //     The sets are accessed by the match engine for things like \w (word boundary)
    265 //
    266 enum {
    267      URX_ISWORD_SET  = 1,
    268      URX_ISALNUM_SET = 2,
    269      URX_ISALPHA_SET = 3,
    270      URX_ISSPACE_SET = 4,
    271 
    272      URX_GC_NORMAL,          // Sets for finding grapheme cluster boundaries.
    273      URX_GC_EXTEND,
    274      URX_GC_CONTROL,
    275      URX_GC_L,
    276      URX_GC_LV,
    277      URX_GC_LVT,
    278      URX_GC_V,
    279      URX_GC_T,
    280 
    281      URX_LAST_SET,
    282 
    283      URX_NEG_SET     = 0x800000          // Flag bit to reverse sense of set
    284                                          //   membership test.
    285 };
    286 
    287 
    288 //
    289 //  Match Engine State Stack Frame Layout.
    290 //
    291 struct REStackFrame {
    292     // Header
    293     int64_t            fInputIdx;        // Position of next character in the input string
    294     int64_t            fPatIdx;          // Position of next Op in the compiled pattern
    295                                          // (int64_t for UVector64, values fit in an int32_t)
    296     // Remainder
    297     int64_t            fExtra[1];        // Extra state, for capture group start/ends
    298                                          //   atomic parentheses, repeat counts, etc.
    299                                          //   Locations assigned at pattern compile time.
    300                                          //   Variable-length array.
    301 };
    302 // number of UVector elements in the header
    303 #define RESTACKFRAME_HDRCOUNT 2
    304 
    305 //
    306 //  Start-Of-Match type.  Used by find() to quickly scan to positions where a
    307 //                        match might start before firing up the full match engine.
    308 //
    309 enum StartOfMatch {
    310     START_NO_INFO,             // No hint available.
    311     START_CHAR,                // Match starts with a literal code point.
    312     START_SET,                 // Match starts with something matching a set.
    313     START_START,               // Match starts at start of buffer only (^ or \A)
    314     START_LINE,                // Match starts with ^ in multi-line mode.
    315     START_STRING               // Match starts with a literal string.
    316 };
    317 
    318 #define START_OF_MATCH_STR(v) ((v)==START_NO_INFO? "START_NO_INFO" : \
    319                                (v)==START_CHAR?    "START_CHAR"    : \
    320                                (v)==START_SET?     "START_SET"     : \
    321                                (v)==START_START?   "START_START"   : \
    322                                (v)==START_LINE?    "START_LINE"    : \
    323                                (v)==START_STRING?  "START_STRING"  : \
    324                                                    "ILLEGAL")
    325 
    326 //
    327 //  8 bit set, to fast-path latin-1 set membership tests.
    328 //
    329 struct Regex8BitSet : public UMemory {
    330     inline Regex8BitSet();
    331     inline void operator = (const Regex8BitSet &s);
    332     inline void init(const UnicodeSet *src);
    333     inline UBool contains(UChar32 c);
    334     inline void  add(UChar32 c);
    335     int8_t d[32];
    336 };
    337 
    338 inline Regex8BitSet::Regex8BitSet() {
    339     uprv_memset(d, 0, sizeof(d));
    340 }
    341 
    342 inline UBool Regex8BitSet::contains(UChar32 c) {
    343     // No bounds checking!  This is deliberate.
    344     return ((d[c>>3] & 1 <<(c&7)) != 0);
    345 }
    346 
    347 inline void  Regex8BitSet::add(UChar32 c) {
    348     d[c>>3] |= 1 << (c&7);
    349 }
    350 
    351 inline void Regex8BitSet::init(const UnicodeSet *s) {
    352     if (s != NULL) {
    353         for (int32_t i=0; i<=255; i++) {
    354             if (s->contains(i)) {
    355                 this->add(i);
    356             }
    357         }
    358     }
    359 }
    360 
    361 inline void Regex8BitSet::operator = (const Regex8BitSet &s) {
    362    uprv_memcpy(d, s.d, sizeof(d));
    363 }
    364 
    365 
    366 //  Case folded UText Iterator helper class.
    367 //  Wraps a UText, provides a case-folded enumeration over its contents.
    368 //  Used in implementing case insensitive matching constructs.
    369 //  Implementation in rematch.cpp
    370 
    371 class CaseFoldingUTextIterator: public UMemory {
    372       public:
    373         CaseFoldingUTextIterator(UText &text);
    374         ~CaseFoldingUTextIterator();
    375 
    376         UChar32 next();           // Next case folded character
    377 
    378         UBool   inExpansion();    // True if last char returned from next() and the
    379                                   //  next to be returned both originated from a string
    380                                   //  folding of the same code point from the orignal UText.
    381       private:
    382         UText             &fUText;
    383         const  UCaseProps *fcsp;
    384         const  UChar      *fFoldChars;
    385         int32_t            fFoldLength;
    386         int32_t            fFoldIndex;
    387 
    388 };
    389 
    390 
    391 // Case folded UChar * string iterator.
    392 //  Wraps a UChar  *, provides a case-folded enumeration over its contents.
    393 //  Used in implementing case insensitive matching constructs.
    394 //  Implementation in rematch.cpp
    395 
    396 class CaseFoldingUCharIterator: public UMemory {
    397       public:
    398         CaseFoldingUCharIterator(const UChar *chars, int64_t start, int64_t limit);
    399         ~CaseFoldingUCharIterator();
    400 
    401         UChar32 next();           // Next case folded character
    402 
    403         UBool   inExpansion();    // True if last char returned from next() and the
    404                                   //  next to be returned both originated from a string
    405                                   //  folding of the same code point from the orignal UText.
    406 
    407         int64_t  getIndex();      // Return the current input buffer index.
    408 
    409       private:
    410         const  UChar      *fChars;
    411         int64_t            fIndex;
    412         int64_t            fLimit;
    413         const  UCaseProps *fcsp;
    414         const  UChar      *fFoldChars;
    415         int32_t            fFoldLength;
    416         int32_t            fFoldIndex;
    417 
    418 };
    419 
    420 U_NAMESPACE_END
    421 #endif
    422 
    423