1 // Copyright 2014 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_COMPILER_SOURCE_POSITION_H_
6 #define V8_COMPILER_SOURCE_POSITION_H_
7 
8 #include "src/assembler.h"
9 #include "src/compiler/node-aux-data.h"
10 
11 namespace v8 {
12 namespace internal {
13 namespace compiler {
14 
15 // Encapsulates encoding and decoding of sources positions from which Nodes
16 // originated.
17 class SourcePosition FINAL {
18  public:
raw_(raw)19   explicit SourcePosition(int raw = kUnknownPosition) : raw_(raw) {}
20 
Unknown()21   static SourcePosition Unknown() { return SourcePosition(kUnknownPosition); }
IsUnknown()22   bool IsUnknown() const { return raw() == kUnknownPosition; }
23 
Invalid()24   static SourcePosition Invalid() { return SourcePosition(kInvalidPosition); }
IsInvalid()25   bool IsInvalid() const { return raw() == kInvalidPosition; }
26 
raw()27   int raw() const { return raw_; }
28 
29  private:
30   static const int kInvalidPosition = -2;
31   static const int kUnknownPosition = RelocInfo::kNoPosition;
32   STATIC_ASSERT(kInvalidPosition != kUnknownPosition);
33   int raw_;
34 };
35 
36 
37 inline bool operator==(const SourcePosition& lhs, const SourcePosition& rhs) {
38   return lhs.raw() == rhs.raw();
39 }
40 
41 inline bool operator!=(const SourcePosition& lhs, const SourcePosition& rhs) {
42   return !(lhs == rhs);
43 }
44 
45 
46 class SourcePositionTable FINAL {
47  public:
48   class Scope {
49    public:
Scope(SourcePositionTable * source_positions,SourcePosition position)50     Scope(SourcePositionTable* source_positions, SourcePosition position)
51         : source_positions_(source_positions),
52           prev_position_(source_positions->current_position_) {
53       Init(position);
54     }
Scope(SourcePositionTable * source_positions,Node * node)55     Scope(SourcePositionTable* source_positions, Node* node)
56         : source_positions_(source_positions),
57           prev_position_(source_positions->current_position_) {
58       Init(source_positions_->GetSourcePosition(node));
59     }
~Scope()60     ~Scope() { source_positions_->current_position_ = prev_position_; }
61 
62    private:
Init(SourcePosition position)63     void Init(SourcePosition position) {
64       if (!position.IsUnknown() || prev_position_.IsInvalid()) {
65         source_positions_->current_position_ = position;
66       }
67     }
68 
69     SourcePositionTable* source_positions_;
70     SourcePosition prev_position_;
71     DISALLOW_COPY_AND_ASSIGN(Scope);
72   };
73 
74   explicit SourcePositionTable(Graph* graph);
~SourcePositionTable()75   ~SourcePositionTable() {
76     if (decorator_ != NULL) RemoveDecorator();
77   }
78 
79   void AddDecorator();
80   void RemoveDecorator();
81 
82   SourcePosition GetSourcePosition(Node* node);
83 
84  private:
85   class Decorator;
86 
87   Graph* graph_;
88   Decorator* decorator_;
89   SourcePosition current_position_;
90   NodeAuxData<SourcePosition> table_;
91 
92   DISALLOW_COPY_AND_ASSIGN(SourcePositionTable);
93 };
94 
95 }  // namespace compiler
96 }  // namespace internal
97 }  // namespace v8
98 
99 #endif
100