[Interpreter] Add option to trace bytecode execution.

src/interpreter/interpreter.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_INTERPRETER_INTERPRETER_H_
 #define V8_INTERPRETER_INTERPRETER_H_
 
 // Clients of this interface shouldn't depend on lots of interpreter internals.
 // Do not include anything from src/interpreter other than
 // src/interpreter/bytecodes.h here!
@@ skipping 97 matching lines @@
                 compiler::InterpreterAssembler* assembler);
 
   // Generates code to perform a lookup slot load via |function_id|.
   void DoLoadLookupSlot(Runtime::FunctionId function_id,
                         compiler::InterpreterAssembler* assembler);
 
   // Generates code to perform a lookup slot store depending on |language_mode|.
   void DoStoreLookupSlot(LanguageMode language_mode,
                          compiler::InterpreterAssembler* assembler);
 
+  // Generates code to trace the currently executing bytecode.
+  void DoTraceBytecodeEntry(compiler::InterpreterAssembler* assembler);
+  void DoTraceBytecodeExit(compiler::InterpreterAssembler* assembler);

[Michael Starzinger, 2016/01/28 12:07:06]

nit: Doesn't seem to be used nor implemented. Looks like leftover.

[rmcilroy, 2016/01/28 16:39:51]

Yup, leftover, thanks. Done.

+
   bool IsInterpreterTableInitialized(Handle<FixedArray> handler_table);
 
   Isolate* isolate_;
 
   DISALLOW_COPY_AND_ASSIGN(Interpreter);
 };
 
 }  // namespace interpreter
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_INTERPRETER_INTERPRETER_H_