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/flags.h"
11 #include "src/globals.h"
12 #include "src/handles.h"
13 #include "src/utils.h"
14 
15 namespace v8 {
16 namespace internal {
17 
18 class Code;
19 class CompilationInfo;
20 class Script;
21 class SharedFunctionInfo;
22 struct SourcePositionInfo;
23 
24 // SourcePosition stores
25 // - script_offset (31 bit non-negative int or kNoSourcePosition)
26 // - inlining_id (16 bit non-negative int or kNotInlined).
27 //
28 // A defined inlining_id refers to positions in
29 // CompilationInfo::inlined_functions or
30 // DeoptimizationInputData::InliningPositions, depending on the compilation
31 // stage.
32 class SourcePosition final {
33  public:
34   explicit SourcePosition(int script_offset, int inlining_id = kNotInlined)
35       : value_(0) {
36     SetScriptOffset(script_offset);
37     SetInliningId(inlining_id);
38   }
39 
Unknown()40   static SourcePosition Unknown() { return SourcePosition(kNoSourcePosition); }
IsKnown()41   bool IsKnown() const {
42     return ScriptOffset() != kNoSourcePosition || InliningId() != kNotInlined;
43   }
isInlined()44   bool isInlined() const { return InliningId() != kNotInlined; }
45 
46   std::vector<SourcePositionInfo> InliningStack(Handle<Code> code) const;
47   std::vector<SourcePositionInfo> InliningStack(CompilationInfo* code) const;
48 
49   void Print(std::ostream& out, Code* function) const;
50 
ScriptOffset()51   int ScriptOffset() const { return ScriptOffsetField::decode(value_) - 1; }
InliningId()52   int InliningId() const { return InliningIdField::decode(value_) - 1; }
53 
SetScriptOffset(int script_offset)54   void SetScriptOffset(int script_offset) {
55     DCHECK(script_offset <= ScriptOffsetField::kMax - 2);
56     DCHECK(script_offset >= kNoSourcePosition);
57     value_ = ScriptOffsetField::update(value_, script_offset + 1);
58   }
SetInliningId(int inlining_id)59   void SetInliningId(int inlining_id) {
60     DCHECK(inlining_id <= InliningIdField::kMax - 2);
61     DCHECK(inlining_id >= kNotInlined);
62     value_ = InliningIdField::update(value_, inlining_id + 1);
63   }
64 
65   static const int kNotInlined = -1;
66   STATIC_ASSERT(kNoSourcePosition == -1);
67 
raw()68   int64_t raw() const { return static_cast<int64_t>(value_); }
FromRaw(int64_t raw)69   static SourcePosition FromRaw(int64_t raw) {
70     SourcePosition position = Unknown();
71     DCHECK_GE(raw, 0);
72     position.value_ = static_cast<uint64_t>(raw);
73     return position;
74   }
75 
76  private:
77   void Print(std::ostream& out, SharedFunctionInfo* function) const;
78   SourcePositionInfo Info(Handle<SharedFunctionInfo> script) const;
79 
80   // InliningId is in the high bits for better compression in
81   // SourcePositionTable.
82   typedef BitField64<int, 0, 31> ScriptOffsetField;
83   typedef BitField64<int, 31, 16> InliningIdField;
84   // Leaving the highest bit untouched to allow for signed conversion.
85   uint64_t value_;
86 };
87 
88 inline bool operator==(const SourcePosition& lhs, const SourcePosition& rhs) {
89   return lhs.raw() == rhs.raw();
90 }
91 
92 inline bool operator!=(const SourcePosition& lhs, const SourcePosition& rhs) {
93   return !(lhs == rhs);
94 }
95 
96 struct InliningPosition {
97   // position of the inlined call
98   SourcePosition position = SourcePosition::Unknown();
99 
100   // references position in DeoptimizationInputData::literals()
101   int inlined_function_id;
102 };
103 
104 struct SourcePositionInfo {
SourcePositionInfoSourcePositionInfo105   explicit SourcePositionInfo(SourcePosition pos, Handle<SharedFunctionInfo> f)
106       : position(pos), function(f) {}
107 
108   SourcePosition position;
109   Handle<SharedFunctionInfo> function;
110   int line = -1;
111   int column = -1;
112 };
113 
114 std::ostream& operator<<(std::ostream& out, const SourcePosition& pos);
115 
116 std::ostream& operator<<(std::ostream& out, const SourcePositionInfo& pos);
117 std::ostream& operator<<(std::ostream& out,
118                          const std::vector<SourcePositionInfo>& stack);
119 
120 }  // namespace internal
121 }  // namespace v8
122 
123 #endif  // V8_SOURCE_POSITION_H_
124