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      1 //  2016 and later: Unicode, Inc. and others.
      2 // License & terms of use: http://www.unicode.org/copyright.html
      3 //
      4 //   Copyright (C) 2002-2015 International Business Machines Corporation
      5 //   and others. All rights reserved.
      6 //
      7 //   file:  regeximp.h
      8 //
      9 //           ICU Regular Expressions,
     10 //               Definitions of constant values used in the compiled form of
     11 //               a regular expression pattern.
     12 //
     13 
     14 #ifndef _REGEXIMP_H
     15 #define _REGEXIMP_H
     16 
     17 #include "unicode/utypes.h"
     18 #include "unicode/uobject.h"
     19 #include "unicode/uniset.h"
     20 #include "unicode/utext.h"
     21 
     22 #include "cmemory.h"
     23 #include "ucase.h"
     24 
     25 U_NAMESPACE_BEGIN
     26 
     27 // For debugging, define REGEX_DEBUG
     28 // To define with configure,
     29 //   CPPFLAGS="-DREGEX_DEBUG" ./runConfigureICU --enable-debug --disable-release Linux
     30 
     31 #ifdef REGEX_DEBUG
     32 //
     33 //  debugging options.  Enable one or more of the three #defines immediately following
     34 //
     35 
     36 //#define REGEX_SCAN_DEBUG
     37 #define REGEX_DUMP_DEBUG
     38 #define REGEX_RUN_DEBUG
     39 
     40 //  End of #defines inteded to be directly set.
     41 
     42 #include <stdio.h>
     43 #endif
     44 
     45 #ifdef REGEX_SCAN_DEBUG
     46 #define REGEX_SCAN_DEBUG_PRINTF(a) printf a
     47 #else
     48 #define REGEX_SCAN_DEBUG_PRINTF(a)
     49 #endif
     50 
     51 
     52 //
     53 //  Opcode types     In the compiled form of the regexp, these are the type, or opcodes,
     54 //                   of the entries.
     55 //
     56 enum {
     57      URX_RESERVED_OP   = 0,    // For multi-operand ops, most non-first words.
     58      URX_RESERVED_OP_N = 255,  // For multi-operand ops, negative operand values.
     59      URX_BACKTRACK     = 1,    // Force a backtrack, as if a match test had failed.
     60      URX_END           = 2,
     61      URX_ONECHAR       = 3,    // Value field is the 21 bit unicode char to match
     62      URX_STRING        = 4,    // Value field is index of string start
     63      URX_STRING_LEN    = 5,    // Value field is string length (code units)
     64      URX_STATE_SAVE    = 6,    // Value field is pattern position to push
     65      URX_NOP           = 7,
     66      URX_START_CAPTURE = 8,    // Value field is capture group number.
     67      URX_END_CAPTURE   = 9,    // Value field is capture group number
     68      URX_STATIC_SETREF = 10,   // Value field is index of set in array of sets.
     69      URX_SETREF        = 11,   // Value field is index of set in array of sets.
     70      URX_DOTANY        = 12,
     71      URX_JMP           = 13,   // Value field is destination position in
     72                                                     //   the pattern.
     73      URX_FAIL          = 14,   // Stop match operation,  No match.
     74 
     75      URX_JMP_SAV       = 15,   // Operand:  JMP destination location
     76      URX_BACKSLASH_B   = 16,   // Value field:  0:  \b    1:  \B
     77      URX_BACKSLASH_G   = 17,
     78      URX_JMP_SAV_X     = 18,   // Conditional JMP_SAV,
     79                                //    Used in (x)+, breaks loop on zero length match.
     80                                //    Operand:  Jmp destination.
     81      URX_BACKSLASH_X   = 19,
     82      URX_BACKSLASH_Z   = 20,   // \z   Unconditional end of line.
     83 
     84      URX_DOTANY_ALL    = 21,   // ., in the . matches any mode.
     85      URX_BACKSLASH_D   = 22,   // Value field:  0:  \d    1:  \D
     86      URX_CARET         = 23,   // Value field:  1:  multi-line mode.
     87      URX_DOLLAR        = 24,  // Also for \Z
     88 
     89      URX_CTR_INIT      = 25,   // Counter Inits for {Interval} loops.
     90      URX_CTR_INIT_NG   = 26,   //   2 kinds, normal and non-greedy.
     91                                //   These are 4 word opcodes.  See description.
     92                                //    First Operand:  Data loc of counter variable
     93                                //    2nd   Operand:  Pat loc of the URX_CTR_LOOPx
     94                                //                    at the end of the loop.
     95                                //    3rd   Operand:  Minimum count.
     96                                //    4th   Operand:  Max count, -1 for unbounded.
     97 
     98      URX_DOTANY_UNIX   = 27,   // '.' operator in UNIX_LINES mode, only \n marks end of line.
     99 
    100      URX_CTR_LOOP      = 28,   // Loop Ops for {interval} loops.
    101      URX_CTR_LOOP_NG   = 29,   //   Also in three flavors.
    102                                //   Operand is loc of corresponding CTR_INIT.
    103 
    104      URX_CARET_M_UNIX  = 30,   // '^' operator, test for start of line in multi-line
    105                                //      plus UNIX_LINES mode.
    106 
    107      URX_RELOC_OPRND   = 31,   // Operand value in multi-operand ops that refers
    108                                //   back into compiled pattern code, and thus must
    109                                //   be relocated when inserting/deleting ops in code.
    110 
    111      URX_STO_SP        = 32,   // Store the stack ptr.  Operand is location within
    112                                //   matcher data (not stack data) to store it.
    113      URX_LD_SP         = 33,   // Load the stack pointer.  Operand is location
    114                                //   to load from.
    115      URX_BACKREF       = 34,   // Back Reference.  Parameter is the index of the
    116                                //   capture group variables in the state stack frame.
    117      URX_STO_INP_LOC   = 35,   // Store the input location.  Operand is location
    118                                //   within the matcher stack frame.
    119      URX_JMPX          = 36,  // Conditional JMP.
    120                                //   First Operand:  JMP target location.
    121                                //   Second Operand:  Data location containing an
    122                                //     input position.  If current input position ==
    123                                //     saved input position, FAIL rather than taking
    124                                //     the JMP
    125      URX_LA_START      = 37,   // Starting a LookAround expression.
    126                                //   Save InputPos and SP in static data.
    127                                //   Operand:  Static data offset for the save
    128      URX_LA_END        = 38,   // Ending a Lookaround expression.
    129                                //   Restore InputPos and Stack to saved values.
    130                                //   Operand:  Static data offset for saved data.
    131      URX_ONECHAR_I     = 39,   // Test for case-insensitive match of a literal character.
    132                                //   Operand:  the literal char.
    133      URX_STRING_I      = 40,   // Case insensitive string compare.
    134                                //   First Operand:  Index of start of string in string literals
    135                                //   Second Operand (next word in compiled code):
    136                                //     the length of the string.
    137      URX_BACKREF_I     = 41,   // Case insensitive back reference.
    138                                //   Parameter is the index of the
    139                                //   capture group variables in the state stack frame.
    140      URX_DOLLAR_M      = 42,   // $ in multi-line mode.
    141      URX_CARET_M       = 43,   // ^ in multi-line mode.
    142      URX_LB_START      = 44,   // LookBehind Start.
    143                                //   Paramater is data location
    144      URX_LB_CONT       = 45,   // LookBehind Continue.
    145                                //   Param 0:  the data location
    146                                //   Param 1:  The minimum length of the look-behind match
    147                                //   Param 2:  The max length of the look-behind match
    148      URX_LB_END        = 46,   // LookBehind End.
    149                                //   Parameter is the data location.
    150                                //     Check that match ended at the right spot,
    151                                //     Restore original input string len.
    152      URX_LBN_CONT      = 47,   // Negative LookBehind Continue
    153                                //   Param 0:  the data location
    154                                //   Param 1:  The minimum length of the look-behind match
    155                                //   Param 2:  The max     length of the look-behind match
    156                                //   Param 3:  The pattern loc following the look-behind block.
    157      URX_LBN_END       = 48,   // Negative LookBehind end
    158                                //   Parameter is the data location.
    159                                //   Check that the match ended at the right spot.
    160      URX_STAT_SETREF_N = 49,   // Reference to a prebuilt set (e.g. \w), negated
    161                                //   Operand is index of set in array of sets.
    162      URX_LOOP_SR_I     = 50,   // Init a [set]* loop.
    163                                //   Operand is the sets index in array of user sets.
    164      URX_LOOP_C        = 51,   // Continue a [set]* or OneChar* loop.
    165                                //   Operand is a matcher static data location.
    166                                //   Must always immediately follow  LOOP_x_I instruction.
    167      URX_LOOP_DOT_I    = 52,   // .*, initialization of the optimized loop.
    168                                //   Operand value:
    169                                //      bit 0:
    170                                //         0:  Normal (. doesn't match new-line) mode.
    171                                //         1:  . matches new-line mode.
    172                                //      bit 1:  controls what new-lines are recognized by this operation.
    173                                //         0:  All Unicode New-lines
    174                                //         1:  UNIX_LINES, \u000a only.
    175      URX_BACKSLASH_BU  = 53,   // \b or \B in UREGEX_UWORD mode, using Unicode style
    176                                //   word boundaries.
    177      URX_DOLLAR_D      = 54,   // $ end of input test, in UNIX_LINES mode.
    178      URX_DOLLAR_MD     = 55,   // $ end of input test, in MULTI_LINE and UNIX_LINES mode.
    179      URX_BACKSLASH_H   = 56,   // Value field:  0:  \h    1:  \H
    180      URX_BACKSLASH_R   = 57,   // Any line break sequence.
    181      URX_BACKSLASH_V   = 58    // Value field:  0:  \v    1:  \V
    182 
    183 };
    184 
    185 // Keep this list of opcode names in sync with the above enum
    186 //   Used for debug printing only.
    187 #define URX_OPCODE_NAMES       \
    188         "               ",     \
    189         "BACKTRACK",           \
    190         "END",                 \
    191         "ONECHAR",             \
    192         "STRING",              \
    193         "STRING_LEN",          \
    194         "STATE_SAVE",          \
    195         "NOP",                 \
    196         "START_CAPTURE",       \
    197         "END_CAPTURE",         \
    198         "URX_STATIC_SETREF",   \
    199         "SETREF",              \
    200         "DOTANY",              \
    201         "JMP",                 \
    202         "FAIL",                \
    203         "JMP_SAV",             \
    204         "BACKSLASH_B",         \
    205         "BACKSLASH_G",         \
    206         "JMP_SAV_X",           \
    207         "BACKSLASH_X",         \
    208         "BACKSLASH_Z",         \
    209         "DOTANY_ALL",          \
    210         "BACKSLASH_D",         \
    211         "CARET",               \
    212         "DOLLAR",              \
    213         "CTR_INIT",            \
    214         "CTR_INIT_NG",         \
    215         "DOTANY_UNIX",         \
    216         "CTR_LOOP",            \
    217         "CTR_LOOP_NG",         \
    218         "URX_CARET_M_UNIX",    \
    219         "RELOC_OPRND",         \
    220         "STO_SP",              \
    221         "LD_SP",               \
    222         "BACKREF",             \
    223         "STO_INP_LOC",         \
    224         "JMPX",                \
    225         "LA_START",            \
    226         "LA_END",              \
    227         "ONECHAR_I",           \
    228         "STRING_I",            \
    229         "BACKREF_I",           \
    230         "DOLLAR_M",            \
    231         "CARET_M",             \
    232         "LB_START",            \
    233         "LB_CONT",             \
    234         "LB_END",              \
    235         "LBN_CONT",            \
    236         "LBN_END",             \
    237         "STAT_SETREF_N",       \
    238         "LOOP_SR_I",           \
    239         "LOOP_C",              \
    240         "LOOP_DOT_I",          \
    241         "BACKSLASH_BU",        \
    242         "DOLLAR_D",            \
    243         "DOLLAR_MD",           \
    244         "URX_BACKSLASH_H",     \
    245         "URX_BACKSLASH_R",     \
    246         "URX_BACKSLASH_V"
    247 
    248 
    249 //
    250 //  Convenience macros for assembling and disassembling a compiled operation.
    251 //
    252 #define URX_TYPE(x)          ((uint32_t)(x) >> 24)
    253 #define URX_VAL(x)           ((x) & 0xffffff)
    254 
    255 
    256 //
    257 //  Access to Unicode Sets composite character properties
    258 //     The sets are accessed by the match engine for things like \w (word boundary)
    259 //
    260 enum {
    261      URX_ISWORD_SET  = 1,
    262      URX_ISALNUM_SET = 2,
    263      URX_ISALPHA_SET = 3,
    264      URX_ISSPACE_SET = 4,
    265 
    266      URX_GC_NORMAL,          // Sets for finding grapheme cluster boundaries.
    267      URX_GC_EXTEND,
    268      URX_GC_CONTROL,
    269      URX_GC_L,
    270      URX_GC_LV,
    271      URX_GC_LVT,
    272      URX_GC_V,
    273      URX_GC_T,
    274 
    275      URX_LAST_SET,
    276 
    277      URX_NEG_SET     = 0x800000          // Flag bit to reverse sense of set
    278                                          //   membership test.
    279 };
    280 
    281 
    282 //
    283 //  Match Engine State Stack Frame Layout.
    284 //
    285 struct REStackFrame {
    286     // Header
    287     int64_t            fInputIdx;        // Position of next character in the input string
    288     int64_t            fPatIdx;          // Position of next Op in the compiled pattern
    289                                          // (int64_t for UVector64, values fit in an int32_t)
    290     // Remainder
    291     int64_t            fExtra[1];        // Extra state, for capture group start/ends
    292                                          //   atomic parentheses, repeat counts, etc.
    293                                          //   Locations assigned at pattern compile time.
    294                                          //   Variable-length array.
    295 };
    296 // number of UVector elements in the header
    297 #define RESTACKFRAME_HDRCOUNT 2
    298 
    299 //
    300 //  Start-Of-Match type.  Used by find() to quickly scan to positions where a
    301 //                        match might start before firing up the full match engine.
    302 //
    303 enum StartOfMatch {
    304     START_NO_INFO,             // No hint available.
    305     START_CHAR,                // Match starts with a literal code point.
    306     START_SET,                 // Match starts with something matching a set.
    307     START_START,               // Match starts at start of buffer only (^ or \A)
    308     START_LINE,                // Match starts with ^ in multi-line mode.
    309     START_STRING               // Match starts with a literal string.
    310 };
    311 
    312 #define START_OF_MATCH_STR(v) ((v)==START_NO_INFO? "START_NO_INFO" : \
    313                                (v)==START_CHAR?    "START_CHAR"    : \
    314                                (v)==START_SET?     "START_SET"     : \
    315                                (v)==START_START?   "START_START"   : \
    316                                (v)==START_LINE?    "START_LINE"    : \
    317                                (v)==START_STRING?  "START_STRING"  : \
    318                                                    "ILLEGAL")
    319 
    320 //
    321 //  8 bit set, to fast-path latin-1 set membership tests.
    322 //
    323 struct Regex8BitSet : public UMemory {
    324     inline Regex8BitSet();
    325     inline void operator = (const Regex8BitSet &s);
    326     inline void init(const UnicodeSet *src);
    327     inline UBool contains(UChar32 c);
    328     inline void  add(UChar32 c);
    329     int8_t d[32];
    330 };
    331 
    332 inline Regex8BitSet::Regex8BitSet() {
    333     uprv_memset(d, 0, sizeof(d));
    334 }
    335 
    336 inline UBool Regex8BitSet::contains(UChar32 c) {
    337     // No bounds checking!  This is deliberate.
    338     return ((d[c>>3] & 1 <<(c&7)) != 0);
    339 }
    340 
    341 inline void  Regex8BitSet::add(UChar32 c) {
    342     d[c>>3] |= 1 << (c&7);
    343 }
    344 
    345 inline void Regex8BitSet::init(const UnicodeSet *s) {
    346     if (s != NULL) {
    347         for (int32_t i=0; i<=255; i++) {
    348             if (s->contains(i)) {
    349                 this->add(i);
    350             }
    351         }
    352     }
    353 }
    354 
    355 inline void Regex8BitSet::operator = (const Regex8BitSet &s) {
    356    uprv_memcpy(d, s.d, sizeof(d));
    357 }
    358 
    359 
    360 //  Case folded UText Iterator helper class.
    361 //  Wraps a UText, provides a case-folded enumeration over its contents.
    362 //  Used in implementing case insensitive matching constructs.
    363 //  Implementation in rematch.cpp
    364 
    365 class CaseFoldingUTextIterator: public UMemory {
    366       public:
    367         CaseFoldingUTextIterator(UText &text);
    368         ~CaseFoldingUTextIterator();
    369 
    370         UChar32 next();           // Next case folded character
    371 
    372         UBool   inExpansion();    // True if last char returned from next() and the
    373                                   //  next to be returned both originated from a string
    374                                   //  folding of the same code point from the orignal UText.
    375       private:
    376         UText             &fUText;
    377         const  UChar      *fFoldChars;
    378         int32_t            fFoldLength;
    379         int32_t            fFoldIndex;
    380 
    381 };
    382 
    383 
    384 // Case folded UChar * string iterator.
    385 //  Wraps a UChar  *, provides a case-folded enumeration over its contents.
    386 //  Used in implementing case insensitive matching constructs.
    387 //  Implementation in rematch.cpp
    388 
    389 class CaseFoldingUCharIterator: public UMemory {
    390       public:
    391         CaseFoldingUCharIterator(const UChar *chars, int64_t start, int64_t limit);
    392         ~CaseFoldingUCharIterator();
    393 
    394         UChar32 next();           // Next case folded character
    395 
    396         UBool   inExpansion();    // True if last char returned from next() and the
    397                                   //  next to be returned both originated from a string
    398                                   //  folding of the same code point from the orignal UText.
    399 
    400         int64_t  getIndex();      // Return the current input buffer index.
    401 
    402       private:
    403         const  UChar      *fChars;
    404         int64_t            fIndex;
    405         int64_t            fLimit;
    406         const  UChar      *fFoldChars;
    407         int32_t            fFoldLength;
    408         int32_t            fFoldIndex;
    409 
    410 };
    411 
    412 U_NAMESPACE_END
    413 #endif
    414 
    415