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      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 OptimizedCompilationInfo;
     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 // OptimizedCompilationInfo::inlined_functions or
     30 // DeoptimizationData::InliningPositions, depending on the compilation stage.
     31 class SourcePosition final {
     32  public:
     33   explicit SourcePosition(int script_offset, int inlining_id = kNotInlined)
     34       : value_(0) {
     35     SetScriptOffset(script_offset);
     36     SetInliningId(inlining_id);
     37   }
     38 
     39   static SourcePosition Unknown() { return SourcePosition(kNoSourcePosition); }
     40   bool IsKnown() const {
     41     return ScriptOffset() != kNoSourcePosition || InliningId() != kNotInlined;
     42   }
     43   bool isInlined() const { return InliningId() != kNotInlined; }
     44 
     45   // Assumes that the code object is optimized
     46   std::vector<SourcePositionInfo> InliningStack(Handle<Code> code) const;
     47   std::vector<SourcePositionInfo> InliningStack(
     48       OptimizedCompilationInfo* cinfo) const;
     49 
     50   void Print(std::ostream& out, Code* code) const;
     51   void PrintJson(std::ostream& out) const;
     52 
     53   int ScriptOffset() const { return ScriptOffsetField::decode(value_) - 1; }
     54   int InliningId() const { return InliningIdField::decode(value_) - 1; }
     55 
     56   void SetScriptOffset(int script_offset) {
     57     DCHECK(script_offset <= ScriptOffsetField::kMax - 2);
     58     DCHECK_GE(script_offset, kNoSourcePosition);
     59     value_ = ScriptOffsetField::update(value_, script_offset + 1);
     60   }
     61   void SetInliningId(int inlining_id) {
     62     DCHECK(inlining_id <= InliningIdField::kMax - 2);
     63     DCHECK_GE(inlining_id, kNotInlined);
     64     value_ = InliningIdField::update(value_, inlining_id + 1);
     65   }
     66 
     67   static const int kNotInlined = -1;
     68   STATIC_ASSERT(kNoSourcePosition == -1);
     69 
     70   int64_t raw() const { return static_cast<int64_t>(value_); }
     71   static SourcePosition FromRaw(int64_t raw) {
     72     SourcePosition position = Unknown();
     73     DCHECK_GE(raw, 0);
     74     position.value_ = static_cast<uint64_t>(raw);
     75     return position;
     76   }
     77 
     78  private:
     79   void Print(std::ostream& out, SharedFunctionInfo* function) const;
     80 
     81   // InliningId is in the high bits for better compression in
     82   // SourcePositionTable.
     83   typedef BitField64<int, 0, 31> ScriptOffsetField;
     84   typedef BitField64<int, 31, 16> InliningIdField;
     85   // Leaving the highest bit untouched to allow for signed conversion.
     86   uint64_t value_;
     87 };
     88 
     89 inline bool operator==(const SourcePosition& lhs, const SourcePosition& rhs) {
     90   return lhs.raw() == rhs.raw();
     91 }
     92 
     93 inline bool operator!=(const SourcePosition& lhs, const SourcePosition& rhs) {
     94   return !(lhs == rhs);
     95 }
     96 
     97 struct InliningPosition {
     98   // position of the inlined call
     99   SourcePosition position = SourcePosition::Unknown();
    100 
    101   // references position in DeoptimizationData::literals()
    102   int inlined_function_id;
    103 };
    104 
    105 struct SourcePositionInfo {
    106   SourcePositionInfo(SourcePosition pos, Handle<SharedFunctionInfo> f);
    107 
    108   SourcePosition position;
    109   Handle<Script> script;
    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