V8 API Reference, 7.2.502.16 (for Deno 0.2.4)
regexp-macro-assembler.h
1 // Copyright 2012 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_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
6 #define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
7 
8 #include "src/label.h"
9 #include "src/regexp/regexp-ast.h"
10 
11 namespace v8 {
12 namespace internal {
13 
14 static const uc32 kLeadSurrogateStart = 0xd800;
15 static const uc32 kLeadSurrogateEnd = 0xdbff;
16 static const uc32 kTrailSurrogateStart = 0xdc00;
17 static const uc32 kTrailSurrogateEnd = 0xdfff;
18 static const uc32 kNonBmpStart = 0x10000;
19 static const uc32 kNonBmpEnd = 0x10ffff;
20 
23  Label* on_match;
24 };
25 
26 
28  public:
29  // The implementation must be able to handle at least:
30  static const int kMaxRegister = (1 << 16) - 1;
31  static const int kMaxCPOffset = (1 << 15) - 1;
32  static const int kMinCPOffset = -(1 << 15);
33 
34  static const int kTableSizeBits = 7;
35  static const int kTableSize = 1 << kTableSizeBits;
36  static const int kTableMask = kTableSize - 1;
37 
38  enum IrregexpImplementation {
39  kIA32Implementation,
40  kARMImplementation,
41  kARM64Implementation,
42  kMIPSImplementation,
43  kS390Implementation,
44  kPPCImplementation,
45  kX64Implementation,
46  kX87Implementation,
47  kBytecodeImplementation
48  };
49 
50  enum StackCheckFlag {
51  kNoStackLimitCheck = false,
52  kCheckStackLimit = true
53  };
54 
55  RegExpMacroAssembler(Isolate* isolate, Zone* zone);
56  virtual ~RegExpMacroAssembler();
57  // This function is called when code generation is aborted, so that
58  // the assembler could clean up internal data structures.
59  virtual void AbortedCodeGeneration() {}
60  // The maximal number of pushes between stack checks. Users must supply
61  // kCheckStackLimit flag to push operations (instead of kNoStackLimitCheck)
62  // at least once for every stack_limit() pushes that are executed.
63  virtual int stack_limit_slack() = 0;
64  virtual bool CanReadUnaligned() = 0;
65  virtual void AdvanceCurrentPosition(int by) = 0; // Signed cp change.
66  virtual void AdvanceRegister(int reg, int by) = 0; // r[reg] += by.
67  // Continues execution from the position pushed on the top of the backtrack
68  // stack by an earlier PushBacktrack(Label*).
69  virtual void Backtrack() = 0;
70  virtual void Bind(Label* label) = 0;
71  virtual void CheckAtStart(Label* on_at_start) = 0;
72  // Dispatch after looking the current character up in a 2-bits-per-entry
73  // map. The destinations vector has up to 4 labels.
74  virtual void CheckCharacter(unsigned c, Label* on_equal) = 0;
75  // Bitwise and the current character with the given constant and then
76  // check for a match with c.
77  virtual void CheckCharacterAfterAnd(unsigned c,
78  unsigned and_with,
79  Label* on_equal) = 0;
80  virtual void CheckCharacterGT(uc16 limit, Label* on_greater) = 0;
81  virtual void CheckCharacterLT(uc16 limit, Label* on_less) = 0;
82  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position) = 0;
83  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start) = 0;
84  virtual void CheckNotBackReference(int start_reg, bool read_backward,
85  Label* on_no_match) = 0;
86  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
87  bool read_backward, bool unicode,
88  Label* on_no_match) = 0;
89  // Check the current character for a match with a literal character. If we
90  // fail to match then goto the on_failure label. End of input always
91  // matches. If the label is nullptr then we should pop a backtrack address
92  // off the stack and go to that.
93  virtual void CheckNotCharacter(unsigned c, Label* on_not_equal) = 0;
94  virtual void CheckNotCharacterAfterAnd(unsigned c,
95  unsigned and_with,
96  Label* on_not_equal) = 0;
97  // Subtract a constant from the current character, then and with the given
98  // constant and then check for a match with c.
99  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
100  uc16 minus,
101  uc16 and_with,
102  Label* on_not_equal) = 0;
103  virtual void CheckCharacterInRange(uc16 from,
104  uc16 to, // Both inclusive.
105  Label* on_in_range) = 0;
106  virtual void CheckCharacterNotInRange(uc16 from,
107  uc16 to, // Both inclusive.
108  Label* on_not_in_range) = 0;
109 
110  // The current character (modulus the kTableSize) is looked up in the byte
111  // array, and if the found byte is non-zero, we jump to the on_bit_set label.
112  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0;
113 
114  // Checks whether the given offset from the current position is before
115  // the end of the string. May overwrite the current character.
116  virtual void CheckPosition(int cp_offset, Label* on_outside_input);
117  // Check whether a standard/default character class matches the current
118  // character. Returns false if the type of special character class does
119  // not have custom support.
120  // May clobber the current loaded character.
121  virtual bool CheckSpecialCharacterClass(uc16 type, Label* on_no_match);
122  virtual void Fail() = 0;
123  virtual Handle<HeapObject> GetCode(Handle<String> source) = 0;
124  virtual void GoTo(Label* label) = 0;
125  // Check whether a register is >= a given constant and go to a label if it
126  // is. Backtracks instead if the label is nullptr.
127  virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0;
128  // Check whether a register is < a given constant and go to a label if it is.
129  // Backtracks instead if the label is nullptr.
130  virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0;
131  // Check whether a register is == to the current position and go to a
132  // label if it is.
133  virtual void IfRegisterEqPos(int reg, Label* if_eq) = 0;
134  virtual IrregexpImplementation Implementation() = 0;
135  virtual void LoadCurrentCharacter(int cp_offset,
136  Label* on_end_of_input,
137  bool check_bounds = true,
138  int characters = 1) = 0;
139  virtual void PopCurrentPosition() = 0;
140  virtual void PopRegister(int register_index) = 0;
141  // Pushes the label on the backtrack stack, so that a following Backtrack
142  // will go to this label. Always checks the backtrack stack limit.
143  virtual void PushBacktrack(Label* label) = 0;
144  virtual void PushCurrentPosition() = 0;
145  virtual void PushRegister(int register_index,
146  StackCheckFlag check_stack_limit) = 0;
147  virtual void ReadCurrentPositionFromRegister(int reg) = 0;
148  virtual void ReadStackPointerFromRegister(int reg) = 0;
149  virtual void SetCurrentPositionFromEnd(int by) = 0;
150  virtual void SetRegister(int register_index, int to) = 0;
151  // Return whether the matching (with a global regexp) will be restarted.
152  virtual bool Succeed() = 0;
153  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset) = 0;
154  virtual void ClearRegisters(int reg_from, int reg_to) = 0;
155  virtual void WriteStackPointerToRegister(int reg) = 0;
156 
157  // Compares two-byte strings case insensitively.
158  // Called from generated RegExp code.
159  static int CaseInsensitiveCompareUC16(Address byte_offset1,
160  Address byte_offset2,
161  size_t byte_length, Isolate* isolate);
162 
163  // Check that we are not in the middle of a surrogate pair.
164  void CheckNotInSurrogatePair(int cp_offset, Label* on_failure);
165 
166  // Controls the generation of large inlined constants in the code.
167  void set_slow_safe(bool ssc) { slow_safe_compiler_ = ssc; }
168  bool slow_safe() { return slow_safe_compiler_; }
169 
170  enum GlobalMode {
171  NOT_GLOBAL,
172  GLOBAL_NO_ZERO_LENGTH_CHECK,
173  GLOBAL,
174  GLOBAL_UNICODE
175  };
176  // Set whether the regular expression has the global flag. Exiting due to
177  // a failure in a global regexp may still mean success overall.
178  inline void set_global_mode(GlobalMode mode) { global_mode_ = mode; }
179  inline bool global() { return global_mode_ != NOT_GLOBAL; }
180  inline bool global_with_zero_length_check() {
181  return global_mode_ == GLOBAL || global_mode_ == GLOBAL_UNICODE;
182  }
183  inline bool global_unicode() { return global_mode_ == GLOBAL_UNICODE; }
184 
185  Isolate* isolate() const { return isolate_; }
186  Zone* zone() const { return zone_; }
187 
188  private:
189  bool slow_safe_compiler_;
190  GlobalMode global_mode_;
191  Isolate* isolate_;
192  Zone* zone_;
193 };
194 
195 
196 #ifndef V8_INTERPRETED_REGEXP // Avoid compiling unused code.
197 
199  public:
200  // Type of input string to generate code for.
201  enum Mode { LATIN1 = 1, UC16 = 2 };
202 
203  // Result of calling generated native RegExp code.
204  // RETRY: Something significant changed during execution, and the matching
205  // should be retried from scratch.
206  // EXCEPTION: Something failed during execution. If no exception has been
207  // thrown, it's an internal out-of-memory, and the caller should
208  // throw the exception.
209  // FAILURE: Matching failed.
210  // SUCCESS: Matching succeeded, and the output array has been filled with
211  // capture positions.
212  enum Result { RETRY = -2, EXCEPTION = -1, FAILURE = 0, SUCCESS = 1 };
213 
214  NativeRegExpMacroAssembler(Isolate* isolate, Zone* zone);
215  ~NativeRegExpMacroAssembler() override;
216  bool CanReadUnaligned() override;
217 
218  static Result Match(Handle<Code> regexp,
219  Handle<String> subject,
220  int* offsets_vector,
221  int offsets_vector_length,
222  int previous_index,
223  Isolate* isolate);
224 
225  // Called from RegExp if the backtrack stack limit is hit.
226  // Tries to expand the stack. Returns the new stack-pointer if
227  // successful, and updates the stack_top address, or returns 0 if unable
228  // to grow the stack.
229  // This function must not trigger a garbage collection.
230  static Address GrowStack(Address stack_pointer, Address* stack_top,
231  Isolate* isolate);
232 
233  static const byte* StringCharacterPosition(String subject, int start_index);
234 
235  static int CheckStackGuardState(Isolate* isolate, int start_index,
236  bool is_direct_call, Address* return_address,
237  Code re_code, Address* subject,
238  const byte** input_start,
239  const byte** input_end);
240 
241  // Byte map of one byte characters with a 0xff if the character is a word
242  // character (digit, letter or underscore) and 0x00 otherwise.
243  // Used by generated RegExp code.
244  static const byte word_character_map[256];
245 
246  static Address word_character_map_address() {
247  return reinterpret_cast<Address>(&word_character_map[0]);
248  }
249 
250  static Result Execute(Code code, String input, int start_offset,
251  const byte* input_start, const byte* input_end,
252  int* output, int output_size, Isolate* isolate);
253 };
254 
255 #endif // V8_INTERPRETED_REGEXP
256 
257 } // namespace internal
258 } // namespace v8
259 
260 #endif // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_H_
Definition: libplatform.h:13