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1 // Copyright 2017 the V8 project authors. All rights reserved.
2 // Use of this source code is governed by a BSD-style license that can be
3 // found in the LICENSE file.
4 
5 #ifndef V8_OBJECTS_JS_REGEXP_H_
6 #define V8_OBJECTS_JS_REGEXP_H_
7 
8 #include "src/objects/js-array.h"
9 
10 // Has to be the last include (doesn't have include guards):
11 #include "src/objects/object-macros.h"
12 
13 namespace v8 {
14 namespace internal {
15 
16 // Regular expressions
17 // The regular expression holds a single reference to a FixedArray in
18 // the kDataOffset field.
19 // The FixedArray contains the following data:
20 // - tag : type of regexp implementation (not compiled yet, atom or irregexp)
21 // - reference to the original source string
22 // - reference to the original flag string
23 // If it is an atom regexp
24 // - a reference to a literal string to search for
25 // If it is an irregexp regexp:
26 // - a reference to code for Latin1 inputs (bytecode or compiled), or a smi
27 // used for tracking the last usage (used for regexp code flushing).
28 // - a reference to code for UC16 inputs (bytecode or compiled), or a smi
29 // used for tracking the last usage (used for regexp code flushing).
30 // - max number of registers used by irregexp implementations.
31 // - number of capture registers (output values) of the regexp.
32 class JSRegExp : public JSObject {
33  public:
34   // Meaning of Type:
35   // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet.
36   // ATOM: A simple string to match against using an indexOf operation.
37   // IRREGEXP: Compiled with Irregexp.
38   enum Type { NOT_COMPILED, ATOM, IRREGEXP };
39   enum Flag {
40     kNone = 0,
41     kGlobal = 1 << 0,
42     kIgnoreCase = 1 << 1,
43     kMultiline = 1 << 2,
44     kSticky = 1 << 3,
45     kUnicode = 1 << 4,
46     kDotAll = 1 << 5,
47     // Update FlagCount when adding new flags.
48   };
49   typedef base::Flags<Flag> Flags;
50 
FlagCount()51   static constexpr int FlagCount() { return 6; }
52 
53   DECL_ACCESSORS(data, Object)
54   DECL_ACCESSORS(flags, Object)
55   DECL_ACCESSORS(last_index, Object)
56   DECL_ACCESSORS(source, Object)
57 
58   V8_EXPORT_PRIVATE static MaybeHandle<JSRegExp> New(Isolate* isolate,
59                                                      Handle<String> source,
60                                                      Flags flags);
61   static Handle<JSRegExp> Copy(Handle<JSRegExp> regexp);
62 
63   static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp,
64                                           Handle<String> source, Flags flags);
65   static MaybeHandle<JSRegExp> Initialize(Handle<JSRegExp> regexp,
66                                           Handle<String> source,
67                                           Handle<String> flags_string);
68 
69   inline Type TypeTag();
70   // Number of captures (without the match itself).
71   inline int CaptureCount();
72   inline Flags GetFlags();
73   inline String* Pattern();
74   inline Object* CaptureNameMap();
75   inline Object* DataAt(int index);
76   // Set implementation data after the object has been prepared.
77   inline void SetDataAt(int index, Object* value);
78 
code_index(bool is_latin1)79   static int code_index(bool is_latin1) {
80     if (is_latin1) {
81       return kIrregexpLatin1CodeIndex;
82     } else {
83       return kIrregexpUC16CodeIndex;
84     }
85   }
86 
87   DECL_CAST(JSRegExp)
88 
89   // Dispatched behavior.
90   DECL_PRINTER(JSRegExp)
91   DECL_VERIFIER(JSRegExp)
92 
93   static const int kDataOffset = JSObject::kHeaderSize;
94   static const int kSourceOffset = kDataOffset + kPointerSize;
95   static const int kFlagsOffset = kSourceOffset + kPointerSize;
96   static const int kSize = kFlagsOffset + kPointerSize;
97   static const int kLastIndexOffset = kSize;  // In-object field.
98 
99   // Indices in the data array.
100   static const int kTagIndex = 0;
101   static const int kSourceIndex = kTagIndex + 1;
102   static const int kFlagsIndex = kSourceIndex + 1;
103   static const int kDataIndex = kFlagsIndex + 1;
104   // The data fields are used in different ways depending on the
105   // value of the tag.
106   // Atom regexps (literal strings).
107   static const int kAtomPatternIndex = kDataIndex;
108 
109   static const int kAtomDataSize = kAtomPatternIndex + 1;
110 
111   // Irregexp compiled code or bytecode for Latin1. If compilation
112   // fails, this fields hold an exception object that should be
113   // thrown if the regexp is used again.
114   static const int kIrregexpLatin1CodeIndex = kDataIndex;
115   // Irregexp compiled code or bytecode for UC16.  If compilation
116   // fails, this fields hold an exception object that should be
117   // thrown if the regexp is used again.
118   static const int kIrregexpUC16CodeIndex = kDataIndex + 1;
119   // Maximal number of registers used by either Latin1 or UC16.
120   // Only used to check that there is enough stack space
121   static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 2;
122   // Number of captures in the compiled regexp.
123   static const int kIrregexpCaptureCountIndex = kDataIndex + 3;
124   // Maps names of named capture groups (at indices 2i) to their corresponding
125   // (1-based) capture group indices (at indices 2i + 1).
126   static const int kIrregexpCaptureNameMapIndex = kDataIndex + 4;
127 
128   static const int kIrregexpDataSize = kIrregexpCaptureNameMapIndex + 1;
129 
130   // In-object fields.
131   static const int kLastIndexFieldIndex = 0;
132   static const int kInObjectFieldCount = 1;
133 
134   // The uninitialized value for a regexp code object.
135   static const int kUninitializedValue = -1;
136 };
137 
DEFINE_OPERATORS_FOR_FLAGS(JSRegExp::Flags)138 DEFINE_OPERATORS_FOR_FLAGS(JSRegExp::Flags)
139 
140 // JSRegExpResult is just a JSArray with a specific initial map.
141 // This initial map adds in-object properties for "index" and "input"
142 // properties, as assigned by RegExp.prototype.exec, which allows
143 // faster creation of RegExp exec results.
144 // This class just holds constants used when creating the result.
145 // After creation the result must be treated as a JSArray in all regards.
146 class JSRegExpResult : public JSArray {
147  public:
148 #define REG_EXP_RESULT_FIELDS(V) \
149   V(kIndexOffset, kPointerSize)  \
150   V(kInputOffset, kPointerSize)  \
151   V(kGroupsOffset, kPointerSize) \
152   V(kSize, 0)
153 
154   DEFINE_FIELD_OFFSET_CONSTANTS(JSArray::kSize, REG_EXP_RESULT_FIELDS)
155 #undef REG_EXP_RESULT_FIELDS
156 
157   // Indices of in-object properties.
158   static const int kIndexIndex = 0;
159   static const int kInputIndex = 1;
160   static const int kGroupsIndex = 2;
161   static const int kInObjectPropertyCount = 3;
162 
163  private:
164   DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult);
165 };
166 
167 }  // namespace internal
168 }  // namespace v8
169 
170 #include "src/objects/object-macros-undef.h"
171 
172 #endif  // V8_OBJECTS_JS_REGEXP_H_
173