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, SP and active region 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 
Regex8BitSet()332 inline Regex8BitSet::Regex8BitSet() {
333     uprv_memset(d, 0, sizeof(d));
334 }
335 
contains(UChar32 c)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 
add(UChar32 c)341 inline void  Regex8BitSet::add(UChar32 c) {
342     d[c>>3] |= 1 << (c&7);
343 }
344 
init(const UnicodeSet * s)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