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regexp-bytecode-generator.h (6603B)


      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_BYTECODE_GENERATOR_H_
      6 #define V8_REGEXP_REGEXP_BYTECODE_GENERATOR_H_
      7 
      8 #include "irregexp/imported/regexp-macro-assembler.h"
      9 
     10 namespace v8 {
     11 namespace internal {
     12 
     13 // An assembler/generator for the Irregexp byte code.
     14 class V8_EXPORT_PRIVATE RegExpBytecodeGenerator : public RegExpMacroAssembler {
     15 public:
     16  // Create an assembler. Instructions and relocation information are emitted
     17  // into a buffer, with the instructions starting from the beginning and the
     18  // relocation information starting from the end of the buffer. See CodeDesc
     19  // for a detailed comment on the layout (globals.h).
     20  //
     21  // The assembler allocates and grows its own buffer, and buffer_size
     22  // determines the initial buffer size. The buffer is owned by the assembler
     23  // and deallocated upon destruction of the assembler.
     24  RegExpBytecodeGenerator(Isolate* isolate, Zone* zone);
     25  ~RegExpBytecodeGenerator() override;
     26  // The byte-code interpreter checks on each push anyway.
     27  int stack_limit_slack_slot_count() override { return 1; }
     28  bool CanReadUnaligned() const override { return false; }
     29  void Bind(Label* label) override;
     30  void AdvanceCurrentPosition(int by) override;  // Signed cp change.
     31  void PopCurrentPosition() override;
     32  void PushCurrentPosition() override;
     33  void Backtrack() override;
     34  void GoTo(Label* label) override;
     35  void PushBacktrack(Label* label) override;
     36  bool Succeed() override;
     37  void Fail() override;
     38  void PopRegister(int register_index) override;
     39  void PushRegister(int register_index,
     40                    StackCheckFlag check_stack_limit) override;
     41  void AdvanceRegister(int reg, int by) override;  // r[reg] += by.
     42  void SetCurrentPositionFromEnd(int by) override;
     43  void SetRegister(int register_index, int to) override;
     44  void WriteCurrentPositionToRegister(int reg, int cp_offset) override;
     45  void ClearRegisters(int reg_from, int reg_to) override;
     46  void ReadCurrentPositionFromRegister(int reg) override;
     47  void WriteStackPointerToRegister(int reg) override;
     48  void ReadStackPointerFromRegister(int reg) override;
     49  void LoadCurrentCharacterImpl(int cp_offset, Label* on_end_of_input,
     50                                bool check_bounds, int characters,
     51                                int eats_at_least) override;
     52  void CheckCharacter(unsigned c, Label* on_equal) override;
     53  void CheckCharacterAfterAnd(unsigned c, unsigned mask,
     54                              Label* on_equal) override;
     55  void CheckCharacterGT(base::uc16 limit, Label* on_greater) override;
     56  void CheckCharacterLT(base::uc16 limit, Label* on_less) override;
     57  void CheckFixedLengthLoop(Label* on_tos_equals_current_position) override;
     58  void CheckAtStart(int cp_offset, Label* on_at_start) override;
     59  void CheckNotAtStart(int cp_offset, Label* on_not_at_start) override;
     60  void CheckNotCharacter(unsigned c, Label* on_not_equal) override;
     61  void CheckNotCharacterAfterAnd(unsigned c, unsigned mask,
     62                                 Label* on_not_equal) override;
     63  void CheckNotCharacterAfterMinusAnd(base::uc16 c, base::uc16 minus,
     64                                      base::uc16 mask,
     65                                      Label* on_not_equal) override;
     66  void CheckCharacterInRange(base::uc16 from, base::uc16 to,
     67                             Label* on_in_range) override;
     68  void CheckCharacterNotInRange(base::uc16 from, base::uc16 to,
     69                                Label* on_not_in_range) override;
     70  bool CheckCharacterInRangeArray(const ZoneList<CharacterRange>* ranges,
     71                                  Label* on_in_range) override {
     72    // Disabled in the interpreter, because 1) there is no constant pool that
     73    // could store the ByteArray pointer, 2) bytecode size limits are not as
     74    // restrictive as code (e.g. branch distances on arm), 3) bytecode for
     75    // large character classes is already quite compact.
     76    // TODO(jgruber): Consider using BytecodeArrays (with a constant pool)
     77    // instead of plain ByteArrays; then we could implement
     78    // CheckCharacterInRangeArray in the interpreter.
     79    return false;
     80  }
     81  bool CheckCharacterNotInRangeArray(const ZoneList<CharacterRange>* ranges,
     82                                     Label* on_not_in_range) override {
     83    return false;
     84  }
     85  void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) override;
     86  void SkipUntilBitInTable(int cp_offset, Handle<ByteArray> table,
     87                           Handle<ByteArray> nibble_table,
     88                           int advance_by) override;
     89  void CheckNotBackReference(int start_reg, bool read_backward,
     90                             Label* on_no_match) override;
     91  void CheckNotBackReferenceIgnoreCase(int start_reg, bool read_backward,
     92                                       bool unicode,
     93                                       Label* on_no_match) override;
     94  void IfRegisterLT(int register_index, int comparand, Label* if_lt) override;
     95  void IfRegisterGE(int register_index, int comparand, Label* if_ge) override;
     96  void IfRegisterEqPos(int register_index, Label* if_eq) override;
     97 
     98  IrregexpImplementation Implementation() override;
     99  DirectHandle<HeapObject> GetCode(DirectHandle<String> source,
    100                                   RegExpFlags flags) override;
    101 
    102 private:
    103  void ExpandBuffer();
    104 
    105  // Code and bitmap emission.
    106  inline void EmitOrLink(Label* label);
    107  inline void Emit32(uint32_t x);
    108  inline void Emit16(uint32_t x);
    109  inline void Emit8(uint32_t x);
    110  inline void Emit(uint32_t bc, uint32_t arg);
    111  inline void Emit(uint32_t bc, int32_t arg);
    112  void EmitSkipTable(DirectHandle<ByteArray> table);
    113  // Bytecode buffer.
    114  int length();
    115  void Copy(uint8_t* a);
    116 
    117  // The buffer into which code and relocation info are generated.
    118  static constexpr int kInitialBufferSize = 1024;
    119  ZoneVector<uint8_t> buffer_;
    120 
    121  // The program counter.
    122  int pc_;
    123  Label backtrack_;
    124 
    125  int advance_current_start_;
    126  int advance_current_offset_;
    127  int advance_current_end_;
    128 
    129  // Stores jump edges emitted for the bytecode (used by
    130  // RegExpBytecodePeepholeOptimization).
    131  // Key: jump source (offset in buffer_ where jump destination is stored).
    132  // Value: jump destination (offset in buffer_ to jump to).
    133  ZoneUnorderedMap<int, int> jump_edges_;
    134 
    135  Isolate* isolate_;
    136 
    137  static const int kInvalidPC = -1;
    138 
    139  DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpBytecodeGenerator);
    140 };
    141 
    142 }  // namespace internal
    143 }  // namespace v8
    144 
    145 #endif  // V8_REGEXP_REGEXP_BYTECODE_GENERATOR_H_