Add OptimizedCodeList and DeoptimizedCodeList to native contexts. Both lists are weak. This makes i…

src/objects.h

 // Copyright 2012 the V8 project authors. 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.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 4795 matching lines @@
   // [relocation_info]: Code relocation information
   DECL_ACCESSORS(relocation_info, ByteArray)
   void InvalidateRelocation();
 
   // [handler_table]: Fixed array containing offsets of exception handlers.
   DECL_ACCESSORS(handler_table, FixedArray)
 
   // [deoptimization_data]: Array containing data for deopt.
   DECL_ACCESSORS(deoptimization_data, FixedArray)
 
-  // [type_feedback_info]: Struct containing type feedback information for
-  // unoptimized code. Optimized code can temporarily store the head of
-  // the list of code to be deoptimized during mark-compact GC.
-  // STUBs can use this slot to store arbitrary information as a Smi.
-  // Will contain either a TypeFeedbackInfo object, or JSFunction object,
-  // or undefined, or a Smi.
+  // [type_feedback_info]: This field stores various things, depending on the
+  // kind of the code object.
+  //   FUNCTION           => type feedback information.
+  //   STUB               => various things, e.g. a SMI
+  //   OPTIMIZED_FUNCTION => the next_code_link for optimized code list.
   DECL_ACCESSORS(type_feedback_info, Object)
   inline void InitializeTypeFeedbackInfoNoWriteBarrier(Object* value);
   inline int stub_info();
   inline void set_stub_info(int info);
 
-  // Used during GC to code a list of code objects to deoptimize.
-  inline Object* code_to_deoptimize_link();
-  inline void set_code_to_deoptimize_link(Object* value);
-  inline Object** code_to_deoptimize_link_slot();
+  // [next_code_link]: Link for lists of optimized or deoptimized code.
+  // Note that storage for this field is overlapped with typefeedback_info.
+  DECL_ACCESSORS(next_code_link, Object)
 
   // [gc_metadata]: Field used to hold GC related metadata. The contents of this
   // field does not have to be traced during garbage collection since
   // it is only used by the garbage collector itself.
   DECL_ACCESSORS(gc_metadata, Object)
 
   // [ic_age]: Inline caching age: the value of the Heap::global_ic_age
   // at the moment when this object was created.
   inline void set_ic_age(int count);
   inline int ic_age();
@@ skipping 298 matching lines @@
   static const int kMaxLoopNestingMarker = 6;
 
   // Layout description.
   static const int kInstructionSizeOffset = HeapObject::kHeaderSize;
   static const int kRelocationInfoOffset = kInstructionSizeOffset + kIntSize;
   static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize;
   static const int kDeoptimizationDataOffset =
       kHandlerTableOffset + kPointerSize;
   static const int kTypeFeedbackInfoOffset =
       kDeoptimizationDataOffset + kPointerSize;
+  static const int kNextCodeLinkOffset = kTypeFeedbackInfoOffset;  // Shared.
   static const int kGCMetadataOffset = kTypeFeedbackInfoOffset + kPointerSize;
   static const int kICAgeOffset =
       kGCMetadataOffset + kPointerSize;
   static const int kFlagsOffset = kICAgeOffset + kIntSize;
   static const int kKindSpecificFlags1Offset = kFlagsOffset + kIntSize;
   static const int kKindSpecificFlags2Offset =
       kKindSpecificFlags1Offset + kIntSize;
   // Note: We might be able to squeeze this into the flags above.
   static const int kPrologueOffset = kKindSpecificFlags2Offset + kIntSize;
 
@@ skipping 1853 matching lines @@
   // not have one. Note that this method does not copy the initial map
   // if it has one already, but simply replaces it with the new value.
   // Instances created afterwards will have a map whose [[class]] is
   // set to 'value', but there is no guarantees on instances created
   // before.
   void SetInstanceClassName(String* name);
 
   // Returns if this function has been compiled to native code yet.
   inline bool is_compiled();
 
-  // [next_function_link]: Field for linking functions. This list is treated as
-  // a weak list by the GC.
+  // [next_function_link]: Links functions into various lists, e.g. the list
+  // of optimized functions hanging off the native_context. The CodeFlusher
+  // uses this link to chain together flushing candidates. Treated weakly
+  // by the garbage collector.
   DECL_ACCESSORS(next_function_link, Object)
 
   // Prints the name of the function using PrintF.
   void PrintName(FILE* out = stdout);
 
   // Casting.
   static inline JSFunction* cast(Object* obj);
 
   // Iterates the objects, including code objects indirectly referenced
   // through pointers to the first instruction in the code object.
@@ skipping 3140 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_