DXR is a code search and navigation tool aimed at making sense of large projects. It supports full-text and regex searches as well as structural queries.

Implementation

Mercurial (31ec81b5d7bb)

VCS Links

Line Code
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422
//
//   Copyright (C) 2002-2012 International Business Machines Corporation
//   and others. All rights reserved.
//
//   file:  regeximp.h
//
//           ICU Regular Expressions,
//               Definitions of constant values used in the compiled form of
//               a regular expression pattern.
//

#ifndef _REGEXIMP_H
#define _REGEXIMP_H

#include "unicode/utypes.h"
#include "unicode/uobject.h"
#include "unicode/uniset.h"
#include "unicode/utext.h"

#include "cmemory.h"
#include "ucase.h"

U_NAMESPACE_BEGIN

// For debugging, define REGEX_DEBUG 
// To define with configure,
//   ./runConfigureICU --enable-debug --disable-release Linux CPPFLAGS="-DREGEX_DEBUG"

#ifdef REGEX_DEBUG   
//
//  debugging options.  Enable one or more of the three #defines immediately following
//

//#define REGEX_SCAN_DEBUG
#define REGEX_DUMP_DEBUG
#define REGEX_RUN_DEBUG

//  End of #defines inteded to be directly set.

#include <stdio.h>
#endif

#ifdef REGEX_SCAN_DEBUG
#define REGEX_SCAN_DEBUG_PRINTF(a) printf a
#else
#define REGEX_SCAN_DEBUG_PRINTF(a)
#endif

#ifdef REGEX_DUMP_DEBUG
#define REGEX_DUMP_DEBUG_PRINTF(a) printf a
#else
#define REGEX_DUMP_DEBUG_PRINTF(a)
#endif

#ifdef REGEX_RUN_DEBUG
#define REGEX_RUN_DEBUG_PRINTF(a) printf a
#define REGEX_DUMP_DEBUG_PRINTF(a) printf a
#else
#define REGEX_RUN_DEBUG_PRINTF(a)
#endif


//
//  Opcode types     In the compiled form of the regexp, these are the type, or opcodes,
//                   of the entries.
//
enum {
     URX_RESERVED_OP   = 0,    // For multi-operand ops, most non-first words.
     URX_RESERVED_OP_N = 255,  // For multi-operand ops, negative operand values.
     URX_BACKTRACK     = 1,    // Force a backtrack, as if a match test had failed.
     URX_END           = 2,
     URX_ONECHAR       = 3,    // Value field is the 21 bit unicode char to match
     URX_STRING        = 4,    // Value field is index of string start
     URX_STRING_LEN    = 5,    // Value field is string length (code units)
     URX_STATE_SAVE    = 6,    // Value field is pattern position to push
     URX_NOP           = 7,
     URX_START_CAPTURE = 8,    // Value field is capture group number.
     URX_END_CAPTURE   = 9,    // Value field is capture group number
     URX_STATIC_SETREF = 10,   // Value field is index of set in array of sets.
     URX_SETREF        = 11,   // Value field is index of set in array of sets.
     URX_DOTANY        = 12,
     URX_JMP           = 13,   // Value field is destination position in
                                                    //   the pattern.
     URX_FAIL          = 14,   // Stop match operation,  No match.

     URX_JMP_SAV       = 15,   // Operand:  JMP destination location
     URX_BACKSLASH_B   = 16,   // Value field:  0:  \b    1:  \B
     URX_BACKSLASH_G   = 17,
     URX_JMP_SAV_X     = 18,   // Conditional JMP_SAV,
                               //    Used in (x)+, breaks loop on zero length match.
                               //    Operand:  Jmp destination.
     URX_BACKSLASH_X   = 19,
     URX_BACKSLASH_Z   = 20,   // \z   Unconditional end of line.

     URX_DOTANY_ALL    = 21,   // ., in the . matches any mode.
     URX_BACKSLASH_D   = 22,   // Value field:  0:  \d    1:  \D
     URX_CARET         = 23,   // Value field:  1:  multi-line mode.
     URX_DOLLAR        = 24,  // Also for \Z

     URX_CTR_INIT      = 25,   // Counter Inits for {Interval} loops.
     URX_CTR_INIT_NG   = 26,   //   2 kinds, normal and non-greedy.
                               //   These are 4 word opcodes.  See description.
                               //    First Operand:  Data loc of counter variable
                               //    2nd   Operand:  Pat loc of the URX_CTR_LOOPx
                               //                    at the end of the loop.
                               //    3rd   Operand:  Minimum count.
                               //    4th   Operand:  Max count, -1 for unbounded.

     URX_DOTANY_UNIX   = 27,   // '.' operator in UNIX_LINES mode, only \n marks end of line.

     URX_CTR_LOOP      = 28,   // Loop Ops for {interval} loops.
     URX_CTR_LOOP_NG   = 29,   //   Also in three flavors.
                               //   Operand is loc of corresponding CTR_INIT.

     URX_CARET_M_UNIX  = 30,   // '^' operator, test for start of line in multi-line
                               //      plus UNIX_LINES mode.

     URX_RELOC_OPRND   = 31,   // Operand value in multi-operand ops that refers
                               //   back into compiled pattern code, and thus must
                               //   be relocated when inserting/deleting ops in code.

     URX_STO_SP        = 32,   // Store the stack ptr.  Operand is location within
                               //   matcher data (not stack data) to store it.
     URX_LD_SP         = 33,   // Load the stack pointer.  Operand is location
                               //   to load from.
     URX_BACKREF       = 34,   // Back Reference.  Parameter is the index of the
                               //   capture group variables in the state stack frame.
     URX_STO_INP_LOC   = 35,   // Store the input location.  Operand is location
                               //   within the matcher stack frame.
     URX_JMPX          = 36,  // Conditional JMP.
                               //   First Operand:  JMP target location.
                               //   Second Operand:  Data location containing an
                               //     input position.  If current input position ==
                               //     saved input position, FAIL rather than taking
                               //     the JMP
     URX_LA_START      = 37,   // Starting a LookAround expression.
                               //   Save InputPos and SP in static data.
                               //   Operand:  Static data offset for the save
     URX_LA_END        = 38,   // Ending a Lookaround expression.
                               //   Restore InputPos and Stack to saved values.
                               //   Operand:  Static data offset for saved data.
     URX_ONECHAR_I     = 39,   // Test for case-insensitive match of a literal character.
                               //   Operand:  the literal char.
     URX_STRING_I      = 40,   // Case insensitive string compare.
                               //   First Operand:  Index of start of string in string literals
                               //   Second Operand (next word in compiled code):
                               //     the length of the string.
     URX_BACKREF_I     = 41,   // Case insensitive back reference.
                               //   Parameter is the index of the
                               //   capture group variables in the state stack frame.
     URX_DOLLAR_M      = 42,   // $ in multi-line mode.
     URX_CARET_M       = 43,   // ^ in multi-line mode.
     URX_LB_START      = 44,   // LookBehind Start.
                               //   Paramater is data location
     URX_LB_CONT       = 45,   // LookBehind Continue.
                               //   Param 0:  the data location
                               //   Param 1:  The minimum length of the look-behind match
                               //   Param 2:  The max length of the look-behind match
     URX_LB_END        = 46,   // LookBehind End.
                               //   Parameter is the data location.
                               //     Check that match ended at the right spot,
                               //     Restore original input string len.
     URX_LBN_CONT      = 47,   // Negative LookBehind Continue
                               //   Param 0:  the data location
                               //   Param 1:  The minimum length of the look-behind match
                               //   Param 2:  The max     length of the look-behind match
                               //   Param 3:  The pattern loc following the look-behind block.
     URX_LBN_END       = 48,   // Negative LookBehind end
                               //   Parameter is the data location.
                               //   Check that the match ended at the right spot.
     URX_STAT_SETREF_N = 49,   // Reference to a prebuilt set (e.g. \w), negated
                               //   Operand is index of set in array of sets.
     URX_LOOP_SR_I     = 50,   // Init a [set]* loop.
                               //   Operand is the sets index in array of user sets.
     URX_LOOP_C        = 51,   // Continue a [set]* or OneChar* loop.
                               //   Operand is a matcher static data location.
                               //   Must always immediately follow  LOOP_x_I instruction.
     URX_LOOP_DOT_I    = 52,   // .*, initialization of the optimized loop.
                               //   Operand value:
                               //      bit 0:
                               //         0:  Normal (. doesn't match new-line) mode.
                               //         1:  . matches new-line mode.
                               //      bit 1:  controls what new-lines are recognized by this operation.
                               //         0:  All Unicode New-lines
                               //         1:  UNIX_LINES, \u000a only.
     URX_BACKSLASH_BU  = 53,   // \b or \B in UREGEX_UWORD mode, using Unicode style
                               //   word boundaries.
     URX_DOLLAR_D      = 54,   // $ end of input test, in UNIX_LINES mode.
     URX_DOLLAR_MD     = 55    // $ end of input test, in MULTI_LINE and UNIX_LINES mode.

};

// Keep this list of opcode names in sync with the above enum
//   Used for debug printing only.
#define URX_OPCODE_NAMES       \
        "               ",     \
        "BACKTRACK",           \
        "END",                 \
        "ONECHAR",             \
        "STRING",              \
        "STRING_LEN",          \
        "STATE_SAVE",          \
        "NOP",                 \
        "START_CAPTURE",       \
        "END_CAPTURE",         \
        "URX_STATIC_SETREF",   \
        "SETREF",              \
        "DOTANY",              \
        "JMP",                 \
        "FAIL",                \
        "JMP_SAV",             \
        "BACKSLASH_B",         \
        "BACKSLASH_G",         \
        "JMP_SAV_X",           \
        "BACKSLASH_X",         \
        "BACKSLASH_Z",         \
        "DOTANY_ALL",          \
        "BACKSLASH_D",         \
        "CARET",               \
        "DOLLAR",              \
        "CTR_INIT",            \
        "CTR_INIT_NG",         \
        "DOTANY_UNIX",         \
        "CTR_LOOP",            \
        "CTR_LOOP_NG",         \
        "URX_CARET_M_UNIX",    \
        "RELOC_OPRND",         \
        "STO_SP",              \
        "LD_SP",               \
        "BACKREF",             \
        "STO_INP_LOC",         \
        "JMPX",                \
        "LA_START",            \
        "LA_END",              \
        "ONECHAR_I",           \
        "STRING_I",            \
        "BACKREF_I",           \
        "DOLLAR_M",            \
        "CARET_M",             \
        "LB_START",            \
        "LB_CONT",             \
        "LB_END",              \
        "LBN_CONT",            \
        "LBN_END",             \
        "STAT_SETREF_N",       \
        "LOOP_SR_I",           \
        "LOOP_C",              \
        "LOOP_DOT_I",          \
        "BACKSLASH_BU",        \
        "DOLLAR_D",            \
        "DOLLAR_MD"


//
//  Convenience macros for assembling and disassembling a compiled operation.
//
#define URX_BUILD(type, val) (int32_t)((type << 24) | (val))
#define URX_TYPE(x)          ((uint32_t)(x) >> 24)
#define URX_VAL(x)           ((x) & 0xffffff)


//
//  Access to Unicode Sets composite character properties
//     The sets are accessed by the match engine for things like \w (word boundary)
//
enum {
     URX_ISWORD_SET  = 1,
     URX_ISALNUM_SET = 2,
     URX_ISALPHA_SET = 3,
     URX_ISSPACE_SET = 4,

     URX_GC_NORMAL,          // Sets for finding grapheme cluster boundaries.
     URX_GC_EXTEND,
     URX_GC_CONTROL,
     URX_GC_L,
     URX_GC_LV,
     URX_GC_LVT,
     URX_GC_V,
     URX_GC_T,

     URX_LAST_SET,

     URX_NEG_SET     = 0x800000          // Flag bit to reverse sense of set
                                         //   membership test.
};


//
//  Match Engine State Stack Frame Layout.
//
struct REStackFrame {
    // Header
    int64_t            fInputIdx;        // Position of next character in the input string
    int64_t            fPatIdx;          // Position of next Op in the compiled pattern
                                         // (int64_t for UVector64, values fit in an int32_t)
    // Remainder
    int64_t            fExtra[1];        // Extra state, for capture group start/ends
                                         //   atomic parentheses, repeat counts, etc.
                                         //   Locations assigned at pattern compile time.
                                         //   Variable-length array.
};
// number of UVector elements in the header
#define RESTACKFRAME_HDRCOUNT 2

//
//  Start-Of-Match type.  Used by find() to quickly scan to positions where a
//                        match might start before firing up the full match engine.
//
enum StartOfMatch {
    START_NO_INFO,             // No hint available.
    START_CHAR,                // Match starts with a literal code point.
    START_SET,                 // Match starts with something matching a set.
    START_START,               // Match starts at start of buffer only (^ or \A)
    START_LINE,                // Match starts with ^ in multi-line mode.
    START_STRING               // Match starts with a literal string.
};

#define START_OF_MATCH_STR(v) ((v)==START_NO_INFO? "START_NO_INFO" : \
                               (v)==START_CHAR?    "START_CHAR"    : \
                               (v)==START_SET?     "START_SET"     : \
                               (v)==START_START?   "START_START"   : \
                               (v)==START_LINE?    "START_LINE"    : \
                               (v)==START_STRING?  "START_STRING"  : \
                                                   "ILLEGAL")

//
//  8 bit set, to fast-path latin-1 set membership tests.
//
struct Regex8BitSet : public UMemory {
    inline Regex8BitSet();
    inline void operator = (const Regex8BitSet &s);
    inline void init(const UnicodeSet *src);
    inline UBool contains(UChar32 c);
    inline void  add(UChar32 c);
    int8_t d[32];
};

inline Regex8BitSet::Regex8BitSet() {
    uprv_memset(d, 0, sizeof(d));
}

inline UBool Regex8BitSet::contains(UChar32 c) {
    // No bounds checking!  This is deliberate.
    return ((d[c>>3] & 1 <<(c&7)) != 0);
}

inline void  Regex8BitSet::add(UChar32 c) {
    d[c>>3] |= 1 << (c&7);
}

inline void Regex8BitSet::init(const UnicodeSet *s) {
    if (s != NULL) {
        for (int32_t i=0; i<=255; i++) {
            if (s->contains(i)) {
                this->add(i);
            }
        }
    }
}

inline void Regex8BitSet::operator = (const Regex8BitSet &s) {
   uprv_memcpy(d, s.d, sizeof(d));
}


//  Case folded UText Iterator helper class.
//  Wraps a UText, provides a case-folded enumeration over its contents.
//  Used in implementing case insensitive matching constructs.
//  Implementation in rematch.cpp

class CaseFoldingUTextIterator: public UMemory {
      public:
        CaseFoldingUTextIterator(UText &text);
        ~CaseFoldingUTextIterator();

        UChar32 next();           // Next case folded character 

        UBool   inExpansion();    // True if last char returned from next() and the 
                                  //  next to be returned both originated from a string
                                  //  folding of the same code point from the orignal UText.
      private:
        UText             &fUText;
        const  UCaseProps *fcsp;
        const  UChar      *fFoldChars;
        int32_t            fFoldLength;
        int32_t            fFoldIndex;

};


// Case folded UChar * string iterator.
//  Wraps a UChar  *, provides a case-folded enumeration over its contents.
//  Used in implementing case insensitive matching constructs.
//  Implementation in rematch.cpp

class CaseFoldingUCharIterator: public UMemory {
      public:
        CaseFoldingUCharIterator(const UChar *chars, int64_t start, int64_t limit);
        ~CaseFoldingUCharIterator();

        UChar32 next();           // Next case folded character 

        UBool   inExpansion();    // True if last char returned from next() and the 
                                  //  next to be returned both originated from a string
                                  //  folding of the same code point from the orignal UText.

        int64_t  getIndex();      // Return the current input buffer index.

      private:
        const  UChar      *fChars;
        int64_t            fIndex;
        int64_t            fLimit;
        const  UCaseProps *fcsp;
        const  UChar      *fFoldChars;
        int32_t            fFoldLength;
        int32_t            fFoldIndex;

};

U_NAMESPACE_END
#endif