use variadic macros/templates in IPC message implementation

ipc/ipc_message_templates_impl.h

+// Copyright 2015 The Chromium 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 IPC_IPC_MESSAGE_TEMPLATES_IMPL_H_
+#define IPC_IPC_MESSAGE_TEMPLATES_IMPL_H_
+
+#include "ipc/ipc_message_utils_impl.h"
+
+namespace IPC {
+
+template <uint32_t Id, const char* Name, typename... Ins>
+CommonAsyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<>>::
+    CommonAsyncMessage(int32_t routing_id, const Ins&... ins)
+    : Message(routing_id, ID, PRIORITY_NORMAL) {
+  Schema::Write(this, base::MakeRefTuple(ins...));
+}
+
+template <uint32_t Id, const char* Name, typename... Ins>
+bool CommonAsyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<>>::Read(
+    const Message* msg,
+    Param* p) {
+  return Schema::Read(msg, p);
+}
+
+template <uint32_t Id, const char* Name, typename... Ins>
+void CommonAsyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<>>::Log(
+    std::string* name,
+    const Message* msg,
+    std::string* l) {
+  if (name)
+    *name = Name;
+  if (!msg || !l)
+    return;
+  Param p;
+  if (Schema::Read(msg, &p))
+    LogParam(p, l);
+}
+
+template <uint32_t Id, const char* Name, typename... Ins, typename... Outs>
+CommonSyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<Outs...>>::
+    CommonSyncMessage(int32_t routing_id, const Ins&... ins, Outs*... outs)
+    : SyncMessage(
+          routing_id,
+          ID,
+          PRIORITY_NORMAL,
+          new ParamDeserializer<ReplyParam>(base::MakeRefTuple(*outs...))) {
+  Schema::Write(this, base::MakeRefTuple(ins...));
+}
+
+template <uint32_t Id, const char* Name, typename... Ins, typename... Outs>
+bool CommonSyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<Outs...>>::
+    ReadSendParam(const Message* msg, SendParam* p) {
+  return Schema::ReadSendParam(msg, p);
+}
+
+template <uint32_t Id, const char* Name, typename... Ins, typename... Outs>
+bool CommonSyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<Outs...>>::
+    ReadReplyParam(const Message* msg,
+                   typename base::TupleTypes<ReplyParam>::ValueTuple* p) {
+  return Schema::ReadReplyParam(msg, p);
+}
+
+template <uint32_t Id, const char* Name, typename... Ins, typename... Outs>
+void CommonSyncMessage<Id, Name, base::Tuple<Ins...>, base::Tuple<Outs...>>::
+    Log(std::string* name, const Message* msg, std::string* l) {
+  if (name)
+    *name = Name;
+  if (!msg || !l)
+    return;
+  if (msg->is_sync()) {
+    typename base::TupleTypes<SendParam>::ValueTuple p;
+    if (Schema::ReadSendParam(msg, &p))
+      LogParam(p, l);
+    AddOutputParamsToLog(msg, l);
+  } else {
+    typename base::TupleTypes<ReplyParam>::ValueTuple p;
+    if (Schema::ReadReplyParam(msg, &p))
+      LogParam(p, l);
+  }
+}
+
+}  // namespace IPC
+
+#endif  // IPC_IPC_MESSAGE_TEMPLATES_IMPL_H_