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_INTERPRETER_BYTECODE_SOURCE_INFO_H_ 6 #define V8_INTERPRETER_BYTECODE_SOURCE_INFO_H_ 7 8 #include "src/common/globals.h" 9 10 namespace v8 { 11 namespace internal { 12 namespace interpreter { 13 14 // Source code position information. 15 class BytecodeSourceInfo final { 16 public: 17 static const int kUninitializedPosition = -1; 18 BytecodeSourceInfo()19 BytecodeSourceInfo() 20 : position_type_(PositionType::kNone), 21 source_position_(kUninitializedPosition) {} 22 BytecodeSourceInfo(int source_position,bool is_statement)23 BytecodeSourceInfo(int source_position, bool is_statement) 24 : position_type_(is_statement ? PositionType::kStatement 25 : PositionType::kExpression), 26 source_position_(source_position) { 27 DCHECK_GE(source_position, 0); 28 } 29 30 // Makes instance into a statement position. MakeStatementPosition(int source_position)31 void MakeStatementPosition(int source_position) { 32 // Statement positions can be replaced by other statement 33 // positions. For example , "for (x = 0; x < 3; ++x) 7;" has a 34 // statement position associated with 7 but no bytecode associated 35 // with it. Then Next is emitted after the body and has 36 // statement position and overrides the existing one. 37 position_type_ = PositionType::kStatement; 38 source_position_ = source_position; 39 } 40 41 // Makes instance into an expression position. Instance should not 42 // be a statement position otherwise it could be lost and impair the 43 // debugging experience. MakeExpressionPosition(int source_position)44 void MakeExpressionPosition(int source_position) { 45 DCHECK(!is_statement()); 46 position_type_ = PositionType::kExpression; 47 source_position_ = source_position; 48 } 49 50 // Forces an instance into an expression position. ForceExpressionPosition(int source_position)51 void ForceExpressionPosition(int source_position) { 52 position_type_ = PositionType::kExpression; 53 source_position_ = source_position; 54 } 55 source_position()56 int source_position() const { 57 DCHECK(is_valid()); 58 return source_position_; 59 } 60 is_statement()61 bool is_statement() const { 62 return position_type_ == PositionType::kStatement; 63 } is_expression()64 bool is_expression() const { 65 return position_type_ == PositionType::kExpression; 66 } 67 is_valid()68 bool is_valid() const { return position_type_ != PositionType::kNone; } set_invalid()69 void set_invalid() { 70 position_type_ = PositionType::kNone; 71 source_position_ = kUninitializedPosition; 72 } 73 74 bool operator==(const BytecodeSourceInfo& other) const { 75 return position_type_ == other.position_type_ && 76 source_position_ == other.source_position_; 77 } 78 79 bool operator!=(const BytecodeSourceInfo& other) const { 80 return position_type_ != other.position_type_ || 81 source_position_ != other.source_position_; 82 } 83 84 private: 85 enum class PositionType : uint8_t { kNone, kExpression, kStatement }; 86 87 PositionType position_type_; 88 int source_position_; 89 }; 90 91 V8_EXPORT_PRIVATE std::ostream& operator<<(std::ostream& os, 92 const BytecodeSourceInfo& info); 93 94 } // namespace interpreter 95 } // namespace internal 96 } // namespace v8 97 98 #endif // V8_INTERPRETER_BYTECODE_SOURCE_INFO_H_ 99