Make IC patching resilient to flushing of the original target() ic.

src/stub-cache.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 59 matching lines @@
     Name* key;
     Code* value;
     Map* map;
   };
 
   void Initialize();
 
   Handle<JSObject> StubHolder(Handle<JSObject> receiver,
                               Handle<JSObject> holder);
 
+  Handle<Code> FindIC(Handle<Name> name,
+                      Handle<JSObject> stub_holder,
+                      Code::Kind kind,
+                      Code::StubType type);
+
   Handle<Code> FindStub(Handle<Name> name,
                         Handle<JSObject> stub_holder,
                         Code::Kind kind,
-                        Code::StubType type,
-                        Code::IcFragment fragment);
-
-  Handle<Code> FindHandler(Handle<Name> name,
-                           Handle<JSObject> stub_holder,
-                           Code::Kind kind,
-                           Code::StubType type);
+                        Code::StubType type);
 
   Handle<Code> ComputeMonomorphicIC(Handle<JSObject> receiver,
                                     Handle<Code> handler,
                                     Handle<Name> name);
   Handle<Code> ComputeKeyedMonomorphicIC(Handle<JSObject> receiver,
                                          Handle<Code> handler,
                                          Handle<Name> name);
 
   // Computes the right stub matching. Inserts the result in the
   // cache before returning.  This might compile a stub if needed.
@@ skipping 559 matching lines @@
   void GenerateLoadInterceptor(Register holder_reg,
                                Handle<JSObject> object,
                                Handle<JSObject> holder,
                                LookupResult* lookup,
                                Handle<Name> name);
   void GenerateLoadPostInterceptor(Register reg,
                                    Handle<JSObject> interceptor_holder,
                                    Handle<Name> name,
                                    LookupResult* lookup);
 
-  Handle<Code> GetCode(Code::IcFragment fragment,
+  Handle<Code> GetICCode(Code::Kind kind,
+                         Code::StubType type,
+                         Handle<Name> name,
+                         InlineCacheState state = MONOMORPHIC);
+
+  Handle<Code> GetCode(Code::Kind kind,
                        Code::StubType type,
-                       Handle<Name> name,
-                       InlineCacheState state = MONOMORPHIC);
+                       Handle<Name> name);
 
   Register receiver() { return registers_[0]; }
   Register name()     { return registers_[1]; }
   Register scratch1() { return registers_[2]; }
   Register scratch2() { return registers_[3]; }
   Register scratch3() { return registers_[4]; }
   Register scratch4() { return registers_[5]; }
 
  private:
   virtual Code::Kind kind() = 0;
@@ skipping 29 matching lines @@
                                  Handle<JSGlobalPropertyCell> cell,
                                  Handle<Name> name,
                                  bool is_dont_delete);
 
   static Register receiver() { return registers()[0]; }
 
  private:
   static Register* registers();
   virtual Code::Kind kind() { return Code::LOAD_IC; }
   virtual Logger::LogEventsAndTags log_kind(Handle<Code> code) {
+    if (!code->is_inline_cache_stub()) return Logger::STUB_TAG;
     return code->ic_state() == MONOMORPHIC
         ? Logger::LOAD_IC_TAG : Logger::LOAD_POLYMORPHIC_IC_TAG;
   }
   virtual void JitEvent(Handle<Name> name, Handle<Code> code);
 };
 
 
 class KeyedLoadStubCompiler: public BaseLoadStubCompiler {
  public:
   explicit KeyedLoadStubCompiler(Isolate* isolate)
       : BaseLoadStubCompiler(isolate, registers()) { }
 
   Handle<Code> CompileLoadElement(Handle<Map> receiver_map);
 
   void CompileElementHandlers(MapHandleList* receiver_maps,
                               CodeHandleList* handlers);
 
   Handle<Code> CompileLoadElementPolymorphic(MapHandleList* receiver_maps);
 
   static void GenerateLoadDictionaryElement(MacroAssembler* masm);
 
   static Register receiver() { return registers()[0]; }
 
  private:
   static Register* registers();
   virtual Code::Kind kind() { return Code::KEYED_LOAD_IC; }
   virtual Logger::LogEventsAndTags log_kind(Handle<Code> code) {
+    if (!code->is_inline_cache_stub()) return Logger::STUB_TAG;
     return code->ic_state() == MONOMORPHIC
         ? Logger::KEYED_LOAD_IC_TAG : Logger::KEYED_LOAD_POLYMORPHIC_IC_TAG;
   }
   virtual void JitEvent(Handle<Name> name, Handle<Code> code);
   virtual void GenerateNameCheck(Handle<Name> name,
                                  Register name_reg,
                                  Label* miss);
 };
 
 
@@ skipping 244 matching lines @@
   Handle<JSFunction> constant_function_;
   bool is_simple_api_call_;
   Handle<FunctionTemplateInfo> expected_receiver_type_;
   Handle<CallHandlerInfo> api_call_info_;
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_STUB_CACHE_H_