// Copyright 2012 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_
#define V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_

#ifdef V8_INTERPRETED_REGEXP

#include "src/regexp/regexp-macro-assembler.h"

namespace v8 {
namespace internal {

// A light-weight assembler for the Irregexp byte code.
class RegExpMacroAssemblerIrregexp: public RegExpMacroAssembler {
 public:
  // Create an assembler. Instructions and relocation information are emitted
  // into a buffer, with the instructions starting from the beginning and the
  // relocation information starting from the end of the buffer. See CodeDesc
  // for a detailed comment on the layout (globals.h).
  //
  // If the provided buffer is nullptr, the assembler allocates and grows its
  // own buffer, and buffer_size determines the initial buffer size. The buffer
  // is owned by the assembler and deallocated upon destruction of the
  // assembler.
  //
  // If the provided buffer is not nullptr, the assembler uses the provided
  // buffer for code generation and assumes its size to be buffer_size. If the
  // buffer is too small, a fatal error occurs. No deallocation of the buffer is
  // done upon destruction of the assembler.
  RegExpMacroAssemblerIrregexp(Isolate* isolate, Vector<byte> buffer,
                               Zone* zone);
  virtual ~RegExpMacroAssemblerIrregexp();
  // The byte-code interpreter checks on each push anyway.
  virtual int stack_limit_slack() { return 1; }
  virtual bool CanReadUnaligned() { return false; }
  virtual void Bind(Label* label);
  virtual void AdvanceCurrentPosition(int by);  // Signed cp change.
  virtual void PopCurrentPosition();
  virtual void PushCurrentPosition();
  virtual void Backtrack();
  virtual void GoTo(Label* label);
  virtual void PushBacktrack(Label* label);
  virtual bool Succeed();
  virtual void Fail();
  virtual void PopRegister(int register_index);
  virtual void PushRegister(int register_index,
                            StackCheckFlag check_stack_limit);
  virtual void AdvanceRegister(int reg, int by);  // r[reg] += by.
  virtual void SetCurrentPositionFromEnd(int by);
  virtual void SetRegister(int register_index, int to);
  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset);
  virtual void ClearRegisters(int reg_from, int reg_to);
  virtual void ReadCurrentPositionFromRegister(int reg);
  virtual void WriteStackPointerToRegister(int reg);
  virtual void ReadStackPointerFromRegister(int reg);
  virtual void LoadCurrentCharacter(int cp_offset,
                                    Label* on_end_of_input,
                                    bool check_bounds = true,
                                    int characters = 1);
  virtual void CheckCharacter(unsigned c, Label* on_equal);
  virtual void CheckCharacterAfterAnd(unsigned c,
                                      unsigned mask,
                                      Label* on_equal);
  virtual void CheckCharacterGT(uc16 limit, Label* on_greater);
  virtual void CheckCharacterLT(uc16 limit, Label* on_less);
  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position);
  virtual void CheckAtStart(Label* on_at_start);
  virtual void CheckNotAtStart(int cp_offset, Label* on_not_at_start);
  virtual void CheckNotCharacter(unsigned c, Label* on_not_equal);
  virtual void CheckNotCharacterAfterAnd(unsigned c,
                                         unsigned mask,
                                         Label* on_not_equal);
  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
                                              uc16 minus,
                                              uc16 mask,
                                              Label* on_not_equal);
  virtual void CheckCharacterInRange(uc16 from,
                                     uc16 to,
                                     Label* on_in_range);
  virtual void CheckCharacterNotInRange(uc16 from,
                                        uc16 to,
                                        Label* on_not_in_range);
  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set);
  virtual void CheckNotBackReference(int start_reg, bool read_backward,
                                     Label* on_no_match);
  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
                                               bool read_backward, bool unicode,
                                               Label* on_no_match);
  virtual void IfRegisterLT(int register_index, int comparand, Label* if_lt);
  virtual void IfRegisterGE(int register_index, int comparand, Label* if_ge);
  virtual void IfRegisterEqPos(int register_index, Label* if_eq);

  virtual IrregexpImplementation Implementation();
  virtual Handle<HeapObject> GetCode(Handle<String> source);

 private:
  void Expand();
  // Code and bitmap emission.
  inline void EmitOrLink(Label* label);
  inline void Emit32(uint32_t x);
  inline void Emit16(uint32_t x);
  inline void Emit8(uint32_t x);
  inline void Emit(uint32_t bc, uint32_t arg);
  // Bytecode buffer.
  int length();
  void Copy(byte* a);

  // The buffer into which code and relocation info are generated.
  Vector<byte> buffer_;
  // The program counter.
  int pc_;
  // True if the assembler owns the buffer, false if buffer is external.
  bool own_buffer_;
  Label backtrack_;

  int advance_current_start_;
  int advance_current_offset_;
  int advance_current_end_;

  Isolate* isolate_;

  static const int kInvalidPC = -1;

  DISALLOW_IMPLICIT_CONSTRUCTORS(RegExpMacroAssemblerIrregexp);
};

}  // namespace internal
}  // namespace v8

#endif  // V8_INTERPRETED_REGEXP

#endif  // V8_REGEXP_REGEXP_MACRO_ASSEMBLER_IRREGEXP_H_