Track JS allocations as they arrive with no affection on performance when tracking is switched off

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 47 matching lines @@
  public:
   AssemblerBase(Isolate* isolate, void* buffer, int buffer_size);
   virtual ~AssemblerBase();
 
   Isolate* isolate() const { return isolate_; }
   int jit_cookie() const { return jit_cookie_; }
 
   bool emit_debug_code() const { return emit_debug_code_; }
   void set_emit_debug_code(bool value) { emit_debug_code_ = value; }
 
+  bool emit_allocations_tracking_code() const {
+    return emit_allocations_tracking_code_;
+  }
+  void set_emit_allocations_tracking_code(bool value) {
+    emit_allocations_tracking_code_ = value;
+  }
+
   bool predictable_code_size() const { return predictable_code_size_; }
   void set_predictable_code_size(bool value) { predictable_code_size_ = value; }
 
   uint64_t enabled_cpu_features() const { return enabled_cpu_features_; }
   void set_enabled_cpu_features(uint64_t features) {
     enabled_cpu_features_ = features;
   }
   bool IsEnabled(CpuFeature f) {
     return (enabled_cpu_features_ & (static_cast<uint64_t>(1) << f)) != 0;
   }
@@ skipping 14 matching lines @@
   bool own_buffer_;
 
   // The program counter, which points into the buffer above and moves forward.
   byte* pc_;
 
  private:
   Isolate* isolate_;
   int jit_cookie_;
   uint64_t enabled_cpu_features_;
   bool emit_debug_code_;
+  bool emit_allocations_tracking_code_;
   bool predictable_code_size_;
 };
 
 
 // Avoids using instructions that vary in size in unpredictable ways between the
 // snapshot and the running VM.
 class PredictableCodeSizeScope {
  public:
   PredictableCodeSizeScope(AssemblerBase* assembler, int expected_size);
   ~PredictableCodeSizeScope();
@@ skipping 610 matching lines @@
       Isolate* isolate);
   static ExternalReference random_uint32_function(Isolate* isolate);
   static ExternalReference transcendental_cache_array_address(Isolate* isolate);
   static ExternalReference delete_handle_scope_extensions(Isolate* isolate);
 
   static ExternalReference get_date_field_function(Isolate* isolate);
   static ExternalReference date_cache_stamp(Isolate* isolate);
 
   static ExternalReference get_make_code_young_function(Isolate* isolate);
 
+  // New heap objects tracking support.
+  static ExternalReference record_object_allocation_function(Isolate* isolate);
+
   // Deoptimization support.
   static ExternalReference new_deoptimizer_function(Isolate* isolate);
   static ExternalReference compute_output_frames_function(Isolate* isolate);
 
   // Log support.
   static ExternalReference log_enter_external_function(Isolate* isolate);
   static ExternalReference log_leave_external_function(Isolate* isolate);
 
   // Static data in the keyed lookup cache.
   static ExternalReference keyed_lookup_cache_keys(Isolate* isolate);
@@ skipping 327 matching lines @@
  public:
   NullCallWrapper() { }
   virtual ~NullCallWrapper() { }
   virtual void BeforeCall(int call_size) const { }
   virtual void AfterCall() const { }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_ASSEMBLER_H_