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1 //
2 //  regexcmp.h
3 //
4 //  Copyright (C) 2002-2010, 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);      // Fix literal strings.
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        emitONE_CHAR(UChar32 c);             // Emit a ONE_CHAR op into the compiled code,
107                                                      //   taking case mode into account.
108     int32_t     minMatchLength(int32_t start,
109                                int32_t end);
110     int32_t     maxMatchLength(int32_t start,
111                                int32_t end);
112     void        matchStartType();
113     void        stripNOPs();
114 
115     void        setEval(int32_t op);
116     void        setPushOp(int32_t op);
117     UChar32     scanNamedChar();
118     UnicodeSet *createSetForProperty(const UnicodeString &propName, UBool negated);
119 
120 
121     UErrorCode                    *fStatus;
122     RegexPattern                  *fRXPat;
123     UParseError                   *fParseErr;
124 
125     //
126     //  Data associated with low level character scanning
127     //
128     int64_t                       fScanIndex;        // Index of current character being processed
129                                                      //   in the rule input string.
130     UBool                         fQuoteMode;        // Scan is in a \Q...\E quoted region
131     UBool                         fInBackslashQuote; // Scan is between a '\' and the following char.
132     UBool                         fEOLComments;      // When scan is just after '(?',  inhibit #... to
133                                                      //   end of line comments, in favor of (?#...) comments.
134     int64_t                       fLineNum;          // Line number in input file.
135     int64_t                       fCharNum;          // Char position within the line.
136     UChar32                       fLastChar;         // Previous char, needed to count CR-LF
137                                                      //   as a single line, not two.
138     UChar32                       fPeekChar;         // Saved char, if we've scanned ahead.
139 
140 
141     RegexPatternChar              fC;                // Current char for parse state machine
142                                                      //   processing.
143 
144     //
145     //   Data for the state machine that parses the regular expression.
146     //
147     RegexTableEl                  **fStateTable;     // State Transition Table for regex Rule
148                                                      //   parsing.  index by p[state][char-class]
149 
150     uint16_t                      fStack[kStackSize];  // State stack, holds state pushes
151     int32_t                       fStackPtr;           //  and pops as specified in the state
152                                                        //  transition rules.
153 
154     //
155     //  Data associated with the generation of the pcode for the match engine
156     //
157     int32_t                       fModeFlags;        // Match Flags.  (Case Insensitive, etc.)
158                                                      //   Always has high bit (31) set so that flag values
159                                                      //   on the paren stack are distinguished from relocatable
160                                                      //   pcode addresses.
161     int32_t                       fNewModeFlags;     // New flags, while compiling (?i, holds state
162                                                      //   until last flag is scanned.
163     UBool                         fSetModeFlag;      // true for (?ismx, false for (?-ismx
164 
165 
166     int32_t                       fStringOpStart;    // While a literal string is being scanned
167                                                      //   holds the start index within RegexPattern.
168                                                      //   fLiteralText where the string is being stored.
169 
170     int64_t                       fPatternLength;    // Length of the input pattern string.
171 
172     UVector32                     fParenStack;       // parentheses stack.  Each frame consists of
173                                                      //   the positions of compiled pattern operations
174                                                      //   needing fixup, followed by negative value.  The
175                                                      //   first entry in each frame is the position of the
176                                                      //   spot reserved for use when a quantifier
177                                                      //   needs to add a SAVE at the start of a (block)
178                                                      //   The negative value (-1, -2,...) indicates
179                                                      //   the kind of paren that opened the frame.  Some
180                                                      //   need special handling on close.
181 
182 
183     int32_t                       fMatchOpenParen;   // The position in the compiled pattern
184                                                      //   of the slot reserved for a state save
185                                                      //   at the start of the most recently processed
186                                                      //   parenthesized block.
187     int32_t                       fMatchCloseParen;  // The position in the pattern of the first
188                                                      //   location after the most recently processed
189                                                      //   parenthesized block.
190 
191     int32_t                       fIntervalLow;      // {lower, upper} interval quantifier values.
192     int32_t                       fIntervalUpper;    // Placed here temporarily, when pattern is
193                                                      //   initially scanned.  Each new interval
194                                                      //   encountered overwrites these values.
195                                                      //   -1 for the upper interval value means none
196                                                      //   was specified (unlimited occurences.)
197 
198     int64_t                       fNameStartPos;     // Starting position of a \N{NAME} name in a
199                                                      //   pattern, valid while remainder of name is
200                                                      //   scanned.
201 
202     UStack                        fSetStack;         // Stack of UnicodeSets, used while evaluating
203                                                      //   (at compile time) set expressions within
204                                                      //   the pattern.
205     UStack                        fSetOpStack;       // Stack of pending set operators (&&, --, union)
206 
207     UChar32                       fLastSetLiteral;   // The last single code point added to a set.
208                                                      //   needed when "-y" is scanned, and we need
209                                                      //   to turn "x-y" into a range.
210 };
211 
212 // Constant values to be pushed onto fSetOpStack while scanning & evalueating [set expressions]
213 //   The high 16 bits are the operator precedence, and the low 16 are a code for the operation itself.
214 
215 enum SetOperations {
216     setStart         = 0 << 16 | 1,
217     setEnd           = 1 << 16 | 2,
218     setNegation      = 2 << 16 | 3,
219     setCaseClose     = 2 << 16 | 9,
220     setDifference2   = 3 << 16 | 4,    // '--' set difference operator
221     setIntersection2 = 3 << 16 | 5,    // '&&' set intersection operator
222     setUnion         = 4 << 16 | 6,    // implicit union of adjacent items
223     setDifference1   = 4 << 16 | 7,    // '-', single dash difference op, for compatibility with old UnicodeSet.
224     setIntersection1 = 4 << 16 | 8     // '&', single amp intersection op, for compatibility with old UnicodeSet.
225     };
226 
227 U_NAMESPACE_END
228 #endif   // !UCONFIG_NO_REGULAR_EXPRESSIONS
229 #endif   // RBBISCAN_H
230