1// © 2016 and later: Unicode, Inc. and others.
2// License & terms of use: http://www.unicode.org/copyright.html
3//
4// regexcmp.h
5//
6// Copyright (C) 2002-2016, International Business Machines Corporation and others.
7// All Rights Reserved.
8//
9// This file contains declarations for the class RegexCompile
10//
11// This class is internal to the regular expression implementation.
12// For the public Regular Expression API, see the file "unicode/regex.h"
13//
14
15
16#ifndef RBBISCAN_H
17#define RBBISCAN_H
18
19#include "unicode/utypes.h"
20#if !UCONFIG_NO_REGULAR_EXPRESSIONS
21
22#include "unicode/parseerr.h"
23#include "unicode/uniset.h"
24#include "unicode/uobject.h"
25#include "unicode/utext.h"
26#include "uhash.h"
27#include "uvector.h"
28#include "uvectr32.h"
29
30
31
32U_NAMESPACE_BEGIN
33
34
35//--------------------------------------------------------------------------------
36//
37// class RegexCompile Contains the regular expression compiler.
38//
39//--------------------------------------------------------------------------------
40class RegexPattern;
41
42
43class U_I18N_API RegexCompile : public UMemory {
44public:
45
46 enum {
47 kStackSize = 100 // The size of the state stack for
48 }; // pattern parsing. Corresponds roughly
49 // to the depth of parentheses nesting
50 // that is allowed in the rules.
51
52 struct RegexPatternChar {
53 UChar32 fChar;
54 UBool fQuoted;
55 };
56
57 RegexCompile(RegexPattern *rp, UErrorCode &e);
58
59 void compile(const UnicodeString &pat, UParseError &pp, UErrorCode &e);
60 void compile(UText *pat, UParseError &pp, UErrorCode &e);
61
62
63 virtual ~RegexCompile();
64
65 void nextChar(RegexPatternChar &c); // Get the next char from the input stream.
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
82private:
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 void appendOp(int32_t type, int32_t val); // Build & append a new op to the compiled pattern.
108 int32_t buildOp(int32_t type, int32_t val); // Construct a new pcode instruction.
109 int32_t allocateData(int32_t size); // Allocate space in the matcher data area.
110 // Return index of the newly allocated data.
111 int32_t allocateStackData(int32_t size); // Allocate space in the match back-track stack frame.
112 // Return offset index in the frame.
113 int32_t minMatchLength(int32_t start,
114 int32_t end);
115 int32_t maxMatchLength(int32_t start,
116 int32_t end);
117 void matchStartType();
118 void stripNOPs();
119
120 void setEval(int32_t op);
121 void setPushOp(int32_t op);
122 UChar32 scanNamedChar();
123 UnicodeSet *createSetForProperty(const UnicodeString &propName, UBool negated);
124
125public: // Public for testing only.
126 static void U_EXPORT2 findCaseInsensitiveStarters(UChar32 c, UnicodeSet *starterChars);
127private:
128
129
130 UErrorCode *fStatus;
131 RegexPattern *fRXPat;
132 UParseError *fParseErr;
133
134 //
135 // Data associated with low level character scanning
136 //
137 int64_t fScanIndex; // Index of current character being processed
138 // in the rule input string.
139 UBool fQuoteMode; // Scan is in a \Q...\E quoted region
140 UBool fInBackslashQuote; // Scan is between a '\' and the following char.
141 UBool fEOLComments; // When scan is just after '(?', inhibit #... to
142 // end of line comments, in favor of (?#...) comments.
143 int64_t fLineNum; // Line number in input file.
144 int64_t fCharNum; // Char position within the line.
145 UChar32 fLastChar; // Previous char, needed to count CR-LF
146 // as a single line, not two.
147 UChar32 fPeekChar; // Saved char, if we've scanned ahead.
148
149
150 RegexPatternChar fC; // Current char for parse state machine
151 // processing.
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 occurrences.)
203
204 UStack fSetStack; // Stack of UnicodeSets, used while evaluating
205 // (at compile time) set expressions within
206 // the pattern.
207 UStack fSetOpStack; // Stack of pending set operators (&&, --, union)
208
209 UChar32 fLastSetLiteral; // The last single code point added to a set.
210 // needed when "-y" is scanned, and we need
211 // to turn "x-y" into a range.
212
213 UnicodeString *fCaptureName; // Named Capture, the group name is built up
214 // in this string while being scanned.
215};
216
217// Constant values to be pushed onto fSetOpStack while scanning & evaluating [set expressions]
218// The high 16 bits are the operator precedence, and the low 16 are a code for the operation itself.
219
220enum SetOperations {
221 setStart = 0 << 16 | 1,
222 setEnd = 1 << 16 | 2,
223 setNegation = 2 << 16 | 3,
224 setCaseClose = 2 << 16 | 9,
225 setDifference2 = 3 << 16 | 4, // '--' set difference operator
226 setIntersection2 = 3 << 16 | 5, // '&&' set intersection operator
227 setUnion = 4 << 16 | 6, // implicit union of adjacent items
228 setDifference1 = 4 << 16 | 7, // '-', single dash difference op, for compatibility with old UnicodeSet.
229 setIntersection1 = 4 << 16 | 8 // '&', single amp intersection op, for compatibility with old UnicodeSet.
230 };
231
232U_NAMESPACE_END
233#endif // !UCONFIG_NO_REGULAR_EXPRESSIONS
234#endif // RBBISCAN_H
235

source code of flutter_engine/third_party/icu/source/i18n/regexcmp.h