Ben Murdoch | 097c5b2 | 2016-05-18 11:27:45 +0100 | [diff] [blame^] | 1 | // Copyright 2016 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_SOURCE_POSITION_H_ |
| 6 | #define V8_SOURCE_POSITION_H_ |
| 7 | |
| 8 | #include <ostream> |
| 9 | |
| 10 | #include "src/assembler.h" |
| 11 | #include "src/flags.h" |
| 12 | #include "src/utils.h" |
| 13 | |
| 14 | namespace v8 { |
| 15 | namespace internal { |
| 16 | |
| 17 | // This class encapsulates encoding and decoding of sources positions from |
| 18 | // which hydrogen values originated. |
| 19 | // When FLAG_track_hydrogen_positions is set this object encodes the |
| 20 | // identifier of the inlining and absolute offset from the start of the |
| 21 | // inlined function. |
| 22 | // When the flag is not set we simply track absolute offset from the |
| 23 | // script start. |
| 24 | class SourcePosition { |
| 25 | public: |
| 26 | static SourcePosition Unknown() { |
| 27 | return SourcePosition::FromRaw(kNoPosition); |
| 28 | } |
| 29 | |
| 30 | bool IsUnknown() const { return value_ == kNoPosition; } |
| 31 | |
| 32 | uint32_t position() const { return PositionField::decode(value_); } |
| 33 | void set_position(uint32_t position) { |
| 34 | if (FLAG_hydrogen_track_positions) { |
| 35 | value_ = static_cast<uint32_t>(PositionField::update(value_, position)); |
| 36 | } else { |
| 37 | value_ = position; |
| 38 | } |
| 39 | } |
| 40 | |
| 41 | uint32_t inlining_id() const { return InliningIdField::decode(value_); } |
| 42 | void set_inlining_id(uint32_t inlining_id) { |
| 43 | if (FLAG_hydrogen_track_positions) { |
| 44 | value_ = |
| 45 | static_cast<uint32_t>(InliningIdField::update(value_, inlining_id)); |
| 46 | } |
| 47 | } |
| 48 | |
| 49 | uint32_t raw() const { return value_; } |
| 50 | |
| 51 | private: |
| 52 | static const uint32_t kNoPosition = |
| 53 | static_cast<uint32_t>(RelocInfo::kNoPosition); |
| 54 | typedef BitField<uint32_t, 0, 9> InliningIdField; |
| 55 | |
| 56 | // Offset from the start of the inlined function. |
| 57 | typedef BitField<uint32_t, 9, 23> PositionField; |
| 58 | |
| 59 | friend class HPositionInfo; |
| 60 | friend class Deoptimizer; |
| 61 | |
| 62 | static SourcePosition FromRaw(uint32_t raw_position) { |
| 63 | SourcePosition position; |
| 64 | position.value_ = raw_position; |
| 65 | return position; |
| 66 | } |
| 67 | |
| 68 | // If FLAG_hydrogen_track_positions is set contains bitfields InliningIdField |
| 69 | // and PositionField. |
| 70 | // Otherwise contains absolute offset from the script start. |
| 71 | uint32_t value_; |
| 72 | }; |
| 73 | |
| 74 | inline std::ostream& operator<<(std::ostream& os, const SourcePosition& p) { |
| 75 | if (p.IsUnknown()) { |
| 76 | return os << "<?>"; |
| 77 | } else if (FLAG_hydrogen_track_positions) { |
| 78 | return os << "<" << p.inlining_id() << ":" << p.position() << ">"; |
| 79 | } else { |
| 80 | return os << "<0:" << p.raw() << ">"; |
| 81 | } |
| 82 | } |
| 83 | |
| 84 | } // namespace internal |
| 85 | } // namespace v8 |
| 86 | |
| 87 | #endif // V8_SOURCE_POSITION_H_ |