[interpreter] Add basic framework for bytecode handler code generation.

src/interpreter/bytecodes.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_BYTECODES_H_
+#define V8_INTERPRETER_BYTECODES_H_
+
+#include <iosfwd>
+
+#include "src/utils.h"
+
+namespace v8 {
+namespace internal {
+namespace interpreter {
+
+// The list of bytecodes which are interpreted by the interpreter.
+#define BYTECODE_LIST(V) \
+  V(LoadLiteral0, 1)     \
+  V(Return, 0)
+
+enum class Bytecode : uint8_t {
+#define DECLARE_BYTECODE(Name, _) k##Name,
+  BYTECODE_LIST(DECLARE_BYTECODE)
+#undef DECLARE_BYTECODE
+#define COUNT_BYTECODE(x, _) +1
+  // The COUNT_BYTECODE macro will turn this into kLast = -1 +1 +1... which will
+  // evaluate to the same value as the last real bytecode.
+  kLast = -1 BYTECODE_LIST(COUNT_BYTECODE)
+#undef COUNT_BYTECODE
+};
+
+class Bytecodes {
+ public:
+  // Returns string representation of |bytecode|.
+  static const char* ToString(Bytecode bytecode);
+
+  // Returns the number of arguments expected by |bytecode|.
+  static const int NumberOfArguments(Bytecode bytecode);
+
+  // Returns the size of the bytecode including its arguments.
+  static const int Size(Bytecode bytecode);
+
+  // Returns true if the bytecode is a function return bytecode.
+  static const bool IsReturn(Bytecode bytecode);
+
+ private:
+  Bytecodes() { UNREACHABLE(); }
+};
+
+
+std::ostream& operator<<(std::ostream& os, const Bytecode& bytecode);
+
+}  // namespace interpreter
+}  // namespace internal
+}  // namespace v8
+
+#endif  // V8_INTERPRETER_BYTECODES_H_