Copy irregexp related code from V8.

runtime/vm/regexp_assembler.h

Index: runtime/vm/regexp_assembler.h
diff --git a/runtime/vm/regexp_assembler.h b/runtime/vm/regexp_assembler.h
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index 0000000000000000000000000000000000000000..ace607b9c84400ad1691776770d1a274bd52931b
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+++ b/runtime/vm/regexp_assembler.h
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+// Copyright (c) 2014, the Dart project authors.  Please see the AUTHORS file
+// for details. All rights reserved. Use of this source code is governed by a
+// BSD-style license that can be found in the LICENSE file.
+
+#ifndef VM_REGEXP_ASSEMBLER_H_
+#define VM_REGEXP_ASSEMBLER_H_
+
+// SNIP
+
+namespace dart {
+
+// SNIP
+
+class RegExpMacroAssembler {
+ public:
+  // The implementation must be able to handle at least:
+  static const int kMaxRegister = (1 << 16) - 1;
+  static const int kMaxCPOffset = (1 << 15) - 1;
+  static const int kMinCPOffset = -(1 << 15);
+
+  static const int kTableSizeBits = 7;
+  static const int kTableSize = 1 << kTableSizeBits;
+  static const int kTableMask = kTableSize - 1;
+
+  enum IrregexpImplementation {
+    kIA32Implementation,
+    kARMImplementation,
+    kARM64Implementation,
+    kMIPSImplementation,
+    kX64Implementation,
+    kX87Implementation,
+    kBytecodeImplementation
+  };
+
+  enum StackCheckFlag {
+    kNoStackLimitCheck = false,
+    kCheckStackLimit = true
+  };
+
+  explicit RegExpMacroAssembler(Zone* zone);
+  virtual ~RegExpMacroAssembler();
+  // The maximal number of pushes between stack checks. Users must supply
+  // kCheckStackLimit flag to push operations (instead of kNoStackLimitCheck)
+  // at least once for every stack_limit() pushes that are executed.
+  virtual int stack_limit_slack() = 0;
+  virtual bool CanReadUnaligned() = 0;
+  virtual void AdvanceCurrentPosition(int by) = 0;  // Signed cp change.
+  virtual void AdvanceRegister(int reg, int by) = 0;  // r[reg] += by.
+  // Continues execution from the position pushed on the top of the backtrack
+  // stack by an earlier PushBacktrack(Label*).
+  virtual void Backtrack() = 0;
+  virtual void Bind(Label* label) = 0;
+  virtual void CheckAtStart(Label* on_at_start) = 0;
+  // Dispatch after looking the current character up in a 2-bits-per-entry
+  // map.  The destinations vector has up to 4 labels.
+  virtual void CheckCharacter(unsigned c, Label* on_equal) = 0;
+  // Bitwise and the current character with the given constant and then
+  // check for a match with c.
+  virtual void CheckCharacterAfterAnd(unsigned c,
+                                      unsigned and_with,
+                                      Label* on_equal) = 0;
+  virtual void CheckCharacterGT(uc16 limit, Label* on_greater) = 0;
+  virtual void CheckCharacterLT(uc16 limit, Label* on_less) = 0;
+  virtual void CheckGreedyLoop(Label* on_tos_equals_current_position) = 0;
+  virtual void CheckNotAtStart(Label* on_not_at_start) = 0;
+  virtual void CheckNotBackReference(int start_reg, Label* on_no_match) = 0;
+  virtual void CheckNotBackReferenceIgnoreCase(int start_reg,
+                                               Label* on_no_match) = 0;
+  // Check the current character for a match with a literal character.  If we
+  // fail to match then goto the on_failure label.  End of input always
+  // matches.  If the label is NULL then we should pop a backtrack address off
+  // the stack and go to that.
+  virtual void CheckNotCharacter(unsigned c, Label* on_not_equal) = 0;
+  virtual void CheckNotCharacterAfterAnd(unsigned c,
+                                         unsigned and_with,
+                                         Label* on_not_equal) = 0;
+  // Subtract a constant from the current character, then and with the given
+  // constant and then check for a match with c.
+  virtual void CheckNotCharacterAfterMinusAnd(uc16 c,
+                                              uc16 minus,
+                                              uc16 and_with,
+                                              Label* on_not_equal) = 0;
+  virtual void CheckCharacterInRange(uc16 from,
+                                     uc16 to,  // Both inclusive.
+                                     Label* on_in_range) = 0;
+  virtual void CheckCharacterNotInRange(uc16 from,
+                                        uc16 to,  // Both inclusive.
+                                        Label* on_not_in_range) = 0;
+
+  // The current character (modulus the kTableSize) is looked up in the byte
+  // array, and if the found byte is non-zero, we jump to the on_bit_set label.
+  virtual void CheckBitInTable(Handle<ByteArray> table, Label* on_bit_set) = 0;
+
+  // Checks whether the given offset from the current position is before
+  // the end of the string.  May overwrite the current character.
+  virtual void CheckPosition(int cp_offset, Label* on_outside_input) {
+    LoadCurrentCharacter(cp_offset, on_outside_input, true);
+  }
+  // Check whether a standard/default character class matches the current
+  // character. Returns false if the type of special character class does
+  // not have custom support.
+  // May clobber the current loaded character.
+  virtual bool CheckSpecialCharacterClass(uc16 type,
+                                          Label* on_no_match) {
+    return false;
+  }
+  virtual void Fail() = 0;
+  virtual Handle<HeapObject> GetCode(Handle<String> source) = 0;
+  virtual void GoTo(Label* label) = 0;
+  // Check whether a register is >= a given constant and go to a label if it
+  // is.  Backtracks instead if the label is NULL.
+  virtual void IfRegisterGE(int reg, int comparand, Label* if_ge) = 0;
+  // Check whether a register is < a given constant and go to a label if it is.
+  // Backtracks instead if the label is NULL.
+  virtual void IfRegisterLT(int reg, int comparand, Label* if_lt) = 0;
+  // Check whether a register is == to the current position and go to a
+  // label if it is.
+  virtual void IfRegisterEqPos(int reg, Label* if_eq) = 0;
+  virtual IrregexpImplementation Implementation() = 0;
+  virtual void LoadCurrentCharacter(int cp_offset,
+                                    Label* on_end_of_input,
+                                    bool check_bounds = true,
+                                    int characters = 1) = 0;
+  virtual void PopCurrentPosition() = 0;
+  virtual void PopRegister(int register_index) = 0;
+  // Pushes the label on the backtrack stack, so that a following Backtrack
+  // will go to this label. Always checks the backtrack stack limit.
+  virtual void PushBacktrack(Label* label) = 0;
+  virtual void PushCurrentPosition() = 0;
+  virtual void PushRegister(int register_index,
+                            StackCheckFlag check_stack_limit) = 0;
+  virtual void ReadCurrentPositionFromRegister(int reg) = 0;
+  virtual void ReadStackPointerFromRegister(int reg) = 0;
+  virtual void SetCurrentPositionFromEnd(int by) = 0;
+  virtual void SetRegister(int register_index, int to) = 0;
+  // Return whether the matching (with a global regexp) will be restarted.
+  virtual bool Succeed() = 0;
+  virtual void WriteCurrentPositionToRegister(int reg, int cp_offset) = 0;
+  virtual void ClearRegisters(int reg_from, int reg_to) = 0;
+  virtual void WriteStackPointerToRegister(int reg) = 0;
+
+  // Controls the generation of large inlined constants in the code.
+  void set_slow_safe(bool ssc) { slow_safe_compiler_ = ssc; }
+  bool slow_safe() { return slow_safe_compiler_; }
+
+  enum GlobalMode { NOT_GLOBAL, GLOBAL, GLOBAL_NO_ZERO_LENGTH_CHECK };
+  // Set whether the regular expression has the global flag.  Exiting due to
+  // a failure in a global regexp may still mean success overall.
+  inline void set_global_mode(GlobalMode mode) { global_mode_ = mode; }
+  inline bool global() { return global_mode_ != NOT_GLOBAL; }
+  inline bool global_with_zero_length_check() {
+    return global_mode_ == GLOBAL;
+  }
+
+  Zone* zone() const { return zone_; }
+
+ private:
+  bool slow_safe_compiler_;
+  bool global_mode_;
+  Zone* zone_;
+};
+
+// SNIP
+
+}  // namespace dart
+
+#endif  // VM_REGEXP_ASSEMBLER_H_