Add native callbacks to FastAccessorAssembler.

src/compiler/fast-accessor-assembler.h

 // Copyright 2015 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_COMPILER_FAST_ACCESSOR_ASSEMBLER_H_
 #define V8_COMPILER_FAST_ACCESSOR_ASSEMBLER_H_
 
 #include <stdint.h>
 #include <vector>
 
@@ skipping 30 matching lines @@
 // - After creating the instance, you can call an arbitrary sequence of
 //   builder functions to build the desired function.
 // - When done, you can Build() the accessor and query for the build results.
 //
 // You cannot call any result getters before Build() was called & successful;
 // and you cannot call any builder functions after Build() was called.
 class FastAccessorAssembler {
  public:
   typedef v8::experimental::FastAccessorBuilder::ValueId ValueId;
   typedef v8::experimental::FastAccessorBuilder::LabelId LabelId;
+  typedef v8::FunctionCallback FunctionCallback;
 
   explicit FastAccessorAssembler(Isolate* isolate);
   ~FastAccessorAssembler();
 
   // Builder / assembler functions:
   ValueId IntegerConstant(int int_constant);
   ValueId GetReceiver();
   ValueId LoadInternalField(ValueId value_id, int field_no);
   ValueId LoadValue(ValueId value_id, int offset);
   ValueId LoadObject(ValueId value_id, int offset);
 
   // Builder / assembler functions for control flow.
   void ReturnValue(ValueId value_id);
   void CheckFlagSetOrReturnNull(ValueId value_id, int mask);
   void CheckNotZeroOrReturnNull(ValueId value_id);
-
-  // TODO(vogelheim): Implement a C++ callback.
-  //  void CheckNotNullOrCallback(ValueId value_id, ..c++-callback type...,
-  //     ValueId arg1, ValueId arg2, ...);
-
   LabelId MakeLabel();
   void SetLabel(LabelId label_id);
   void CheckNotZeroOrJump(ValueId value_id, LabelId label_id);
 
+  // C++ callback.
+  ValueId Call(FunctionCallback callback, ValueId arg);
+
   // Assemble the code.
   MaybeHandle<Code> Build();
 
  private:
   ValueId FromRaw(Node* node);
   LabelId FromRaw(RawMachineLabel* label);
   Node* FromId(ValueId value) const;
   RawMachineLabel* FromId(LabelId value) const;
 
   Zone* zone() { return &zone_; }
@@ skipping 12 matching lines @@
   enum { kBuilding, kBuilt, kError } state_;
 
   DISALLOW_COPY_AND_ASSIGN(FastAccessorAssembler);
 };
 
 }  // namespace compiler
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_COMPILER_FAST_ACCESSOR_ASSEMBLER_H_