src/third_party/icu/source/i18n/regexcmp.h

   1 //
   2 //  regexcmp.h
   3 //
   4 //  Copyright (C) 2002-2012, International Business Machines Corporation and others.
   5 //  All Rights Reserved.
   6 //
   7 //  This file contains declarations for the class RegexCompile
   8 //
   9 //  This class is internal to the regular expression implementation.
  10 //  For the public Regular Expression API, see the file "unicode/regex.h"
  11 //
  12
  13
  14 #ifndef RBBISCAN_H
  15 #define RBBISCAN_H
  16
  17 #include "unicode/utypes.h"
  18 #if !UCONFIG_NO_REGULAR_EXPRESSIONS
  19
  20 #include "unicode/uobject.h"
  21 #include "unicode/uniset.h"
  22 #include "unicode/parseerr.h"
  23 #include "uhash.h"
  24 #include "uvector.h"
  25
  26
  27
  28 U_NAMESPACE_BEGIN
  29
  30
  31 //--------------------------------------------------------------------------------
  32 //
  33 //  class RegexCompile    Contains the regular expression compiler.
  34 //
  35 //--------------------------------------------------------------------------------
  36 struct  RegexTableEl;
  37 class   RegexPattern;
  38
  39
  40 class RegexCompile : public UMemory {
  41 public:
  42
  43     enum {
  44         kStackSize = 100            // The size of the state stack for
  45     };                              //   pattern parsing.  Corresponds roughly
  46                                     //   to the depth of parentheses nesting
  47                                     //   that is allowed in the rules.
  48
  49     struct RegexPatternChar {
  50         UChar32             fChar;
  51         UBool               fQuoted;
  52     };
  53
  54     RegexCompile(RegexPattern *rp, UErrorCode &e);
  55
  56     void       compile(const UnicodeString &pat, UParseError &pp, UErrorCode &e);
  57     void       compile(UText *pat, UParseError &pp, UErrorCode &e);
  58
  59
  60     virtual    ~RegexCompile();
  61
  62     void        nextChar(RegexPatternChar &c);      // Get the next char from the input stream.
  63
  64     static void cleanup();                       // Memory cleanup
  65
  66
  67
  68     // Categories of parentheses in pattern.
  69     //   The category is saved in the compile-time parentheses stack frame, and
  70     //   determines the code to be generated when the matching close ) is encountered.
  71     enum EParenClass {
  72         plain        = -1,               // No special handling
  73         capturing    = -2,
  74         atomic       = -3,
  75         lookAhead    = -4,
  76         negLookAhead = -5,
  77         flags        = -6,
  78         lookBehind   = -7,
  79         lookBehindN  = -8
  80     };
  81
  82 private:
  83
  84
  85     UBool       doParseActions(int32_t a);
  86     void        error(UErrorCode e);                   // error reporting convenience function.
  87
  88     UChar32     nextCharLL();
  89     UChar32     peekCharLL();
  90     UnicodeSet  *scanProp();
  91     UnicodeSet  *scanPosixProp();
  92     void        handleCloseParen();
  93     int32_t     blockTopLoc(UBool reserve);          // Locate a position in the compiled pattern
  94                                                      //  at the top of the just completed block
  95                                                      //  or operation, and optionally ensure that
  96                                                      //  there is space to add an opcode there.
  97     void        compileSet(UnicodeSet *theSet);      // Generate the compiled pattern for
  98                                                      //   a reference to a UnicodeSet.
  99     void        compileInterval(int32_t InitOp,      // Generate the code for a {min,max} quantifier.
 100                                int32_t LoopOp);
 101     UBool       compileInlineInterval();             // Generate inline code for a {min,max} quantifier
 102     void        literalChar(UChar32 c);              // Compile a literal char
 103     void        fixLiterals(UBool split=FALSE);      // Generate code for pending literal characters.
 104     void        insertOp(int32_t where);             // Open up a slot for a new op in the
 105                                                      //   generated code at the specified location.
 106     void        appendOp(int32_t op);                // Append a new op to the compiled pattern.
 107     int32_t     allocateData(int32_t size);          // Allocate space in the matcher data area.
 108                                                      //   Return index of the newly allocated data.
 109     int32_t     allocateStackData(int32_t size);     // Allocate space in the match back-track stack frame.
 110                                                      //   Return offset index in the frame.
 111     int32_t     minMatchLength(int32_t start,
 112                                int32_t end);
 113     int32_t     maxMatchLength(int32_t start,
 114                                int32_t end);
 115     void        matchStartType();
 116     void        stripNOPs();
 117
 118     void        setEval(int32_t op);
 119     void        setPushOp(int32_t op);
 120     UChar32     scanNamedChar();
 121     UnicodeSet *createSetForProperty(const UnicodeString &propName, UBool negated);
 122
 123
 124     UErrorCode                    *fStatus;
 125     RegexPattern                  *fRXPat;
 126     UParseError                   *fParseErr;
 127
 128     //
 129     //  Data associated with low level character scanning
 130     //
 131     int64_t                       fScanIndex;        // Index of current character being processed
 132                                                      //   in the rule input string.
 133     UBool                         fQuoteMode;        // Scan is in a \Q...\E quoted region
 134     UBool                         fInBackslashQuote; // Scan is between a '\' and the following char.
 135     UBool                         fEOLComments;      // When scan is just after '(?',  inhibit #... to
 136                                                      //   end of line comments, in favor of (?#...) comments.
 137     int64_t                       fLineNum;          // Line number in input file.
 138     int64_t                       fCharNum;          // Char position within the line.
 139     UChar32                       fLastChar;         // Previous char, needed to count CR-LF
 140                                                      //   as a single line, not two.
 141     UChar32                       fPeekChar;         // Saved char, if we've scanned ahead.
 142
 143
 144     RegexPatternChar              fC;                // Current char for parse state machine
 145                                                      //   processing.
 146
 147     //
 148     //   Data for the state machine that parses the regular expression.
 149     //
 150     RegexTableEl                  **fStateTable;     // State Transition Table for regex Rule
 151                                                      //   parsing.  index by p[state][char-class]
 152
 153     uint16_t                      fStack[kStackSize];  // State stack, holds state pushes
 154     int32_t                       fStackPtr;           //  and pops as specified in the state
 155                                                        //  transition rules.
 156
 157     //
 158     //  Data associated with the generation of the pcode for the match engine
 159     //
 160     int32_t                       fModeFlags;        // Match Flags.  (Case Insensitive, etc.)
 161                                                      //   Always has high bit (31) set so that flag values
 162                                                      //   on the paren stack are distinguished from relocatable
 163                                                      //   pcode addresses.
 164     int32_t                       fNewModeFlags;     // New flags, while compiling (?i, holds state
 165                                                      //   until last flag is scanned.
 166     UBool                         fSetModeFlag;      // true for (?ismx, false for (?-ismx
 167
 168     UnicodeString                 fLiteralChars;     // Literal chars or strings from the pattern are accumulated here.
 169                                                      //   Once completed, meaning that some non-literal pattern
 170                                                      //   construct is encountered, the appropriate opcodes
 171                                                      //   to match the literal will be generated, and this
 172                                                      //   string will be cleared.
 173
 174     int64_t                       fPatternLength;    // Length of the input pattern string.
 175
 176     UVector32                     fParenStack;       // parentheses stack.  Each frame consists of
 177                                                      //   the positions of compiled pattern operations
 178                                                      //   needing fixup, followed by negative value.  The
 179                                                      //   first entry in each frame is the position of the
 180                                                      //   spot reserved for use when a quantifier
 181                                                      //   needs to add a SAVE at the start of a (block)
 182                                                      //   The negative value (-1, -2,...) indicates
 183                                                      //   the kind of paren that opened the frame.  Some
 184                                                      //   need special handling on close.
 185
 186
 187     int32_t                       fMatchOpenParen;   // The position in the compiled pattern
 188                                                      //   of the slot reserved for a state save
 189                                                      //   at the start of the most recently processed
 190                                                      //   parenthesized block. Updated when processing
 191                                                      //   a close to the location for the corresponding open.
 192
 193     int32_t                       fMatchCloseParen;  // The position in the pattern of the first
 194                                                      //   location after the most recently processed
 195                                                      //   parenthesized block.
 196
 197     int32_t                       fIntervalLow;      // {lower, upper} interval quantifier values.
 198     int32_t                       fIntervalUpper;    // Placed here temporarily, when pattern is
 199                                                      //   initially scanned.  Each new interval
 200                                                      //   encountered overwrites these values.
 201                                                      //   -1 for the upper interval value means none
 202                                                      //   was specified (unlimited occurences.)
 203
 204     int64_t                       fNameStartPos;     // Starting position of a \N{NAME} name in a
 205                                                      //   pattern, valid while remainder of name is
 206                                                      //   scanned.
 207
 208     UStack                        fSetStack;         // Stack of UnicodeSets, used while evaluating
 209                                                      //   (at compile time) set expressions within
 210                                                      //   the pattern.
 211     UStack                        fSetOpStack;       // Stack of pending set operators (&&, --, union)
 212
 213     UChar32                       fLastSetLiteral;   // The last single code point added to a set.
 214                                                      //   needed when "-y" is scanned, and we need
 215                                                      //   to turn "x-y" into a range.
 216 };
 217
 218 // Constant values to be pushed onto fSetOpStack while scanning & evalueating [set expressions]
 219 //   The high 16 bits are the operator precedence, and the low 16 are a code for the operation itself.
 220
 221 enum SetOperations {
 222     setStart         = 0 << 16 | 1,
 223     setEnd           = 1 << 16 | 2,
 224     setNegation      = 2 << 16 | 3,
 225     setCaseClose     = 2 << 16 | 9,
 226     setDifference2   = 3 << 16 | 4,    // '--' set difference operator
 227     setIntersection2 = 3 << 16 | 5,    // '&&' set intersection operator
 228     setUnion         = 4 << 16 | 6,    // implicit union of adjacent items
 229     setDifference1   = 4 << 16 | 7,    // '-', single dash difference op, for compatibility with old UnicodeSet.
 230     setIntersection1 = 4 << 16 | 8     // '&', single amp intersection op, for compatibility with old UnicodeSet.
 231     };
 232
 233 U_NAMESPACE_END
 234 #endif   // !UCONFIG_NO_REGULAR_EXPRESSIONS
 235 #endif   // RBBISCAN_H