Remove redundant source position information in RelocInfo

src/assembler.h

 // Copyright (c) 1994-2006 Sun Microsystems Inc.
 // All Rights Reserved.
 //
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 // - Redistributions of source code must retain the above copyright notice,
 // this list of conditions and the following disclaimer.
 //
@@ skipping 626 matching lines @@
   // is returned by RelocInfo::target_reference_address().
   Address reconstructed_adr_ptr_;
   friend class RelocIterator;
 };
 
 
 // RelocInfoWriter serializes a stream of relocation info. It writes towards
 // lower addresses.
 class RelocInfoWriter BASE_EMBEDDED {
  public:
-  RelocInfoWriter() : pos_(NULL),
-                      last_pc_(NULL),
-                      last_id_(0),
-                      last_position_(0) {}
-  RelocInfoWriter(byte* pos, byte* pc) : pos_(pos),
-                                         last_pc_(pc),
-                                         last_id_(0),
-                                         last_position_(0) {}
+  RelocInfoWriter()
+      : pos_(NULL),
+        last_pc_(NULL),
+        last_id_(0),
+        last_position_(0),
+        last_mode_(RelocInfo::NUMBER_OF_MODES),
+        next_position_candidate_pos_delta_(0),
+        next_position_candidate_pc_delta_(0),
+        next_position_candidate_flushed_(true) {}
+  RelocInfoWriter(byte* pos, byte* pc)
+      : pos_(pos),
+        last_pc_(pc),
+        last_id_(0),
+        last_position_(0),
+        last_mode_(RelocInfo::NUMBER_OF_MODES),
+        next_position_candidate_pos_delta_(0),
+        next_position_candidate_pc_delta_(0),
+        next_position_candidate_flushed_(true) {}
 
   byte* pos() const { return pos_; }
   byte* last_pc() const { return last_pc_; }
 
   void Write(const RelocInfo* rinfo);
 
   // Update the state of the stream after reloc info buffer
   // and/or code is moved while the stream is active.
   void Reposition(byte* pos, byte* pc) {
     pos_ = pos;
     last_pc_ = pc;
   }
 
+  void Finish() { FlushPosition(); }
+
   // Max size (bytes) of a written RelocInfo. Longest encoding is
   // ExtraTag, VariableLengthPCJump, ExtraTag, pc_delta, ExtraTag, data_delta.
   // On ia32 and arm this is 1 + 4 + 1 + 1 + 1 + 4 = 12.
   // On x64 this is 1 + 4 + 1 + 1 + 1 + 8 == 16;
   // Here we use the maximum of the two.
   static const int kMaxSize = 16;
 
  private:
   inline uint32_t WriteVariableLengthPCJump(uint32_t pc_delta);
   inline void WriteTaggedPC(uint32_t pc_delta, int tag);
   inline void WriteExtraTaggedPC(uint32_t pc_delta, int extra_tag);
   inline void WriteExtraTaggedIntData(int data_delta, int top_tag);
   inline void WriteExtraTaggedPoolData(int data, int pool_type);
   inline void WriteExtraTaggedData(intptr_t data_delta, int top_tag);
   inline void WriteTaggedData(intptr_t data_delta, int tag);
   inline void WriteExtraTag(int extra_tag, int top_tag);
+  inline void WritePosition(int pc_delta, int pos_delta, RelocInfo::Mode rmode);
+
+  void FlushPosition();
 
   byte* pos_;
   byte* last_pc_;
   int last_id_;
   int last_position_;
+  RelocInfo::Mode last_mode_;
+  int next_position_candidate_pos_delta_;
+  uint32_t next_position_candidate_pc_delta_;
+  bool next_position_candidate_flushed_;
+
   DISALLOW_COPY_AND_ASSIGN(RelocInfoWriter);
 };
 
 
 // A RelocIterator iterates over relocation information.
 // Typical use:
 //
 //   for (RelocIterator it(code); !it.done(); it.next()) {
 //     // do something with it.rinfo() here
 //   }
@@ skipping 433 matching lines @@
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_