Make the implementation .cc files go away, instead have the authors give us a...

ipc/ipc_param_traits_log_macros.h

+// Copyright (c) 2011 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_PARAM_TRAITS_LOG_MACROS_H_
+#define IPC_IPC_PARAM_TRAITS_LOG_MACROS_H_
+
+#include <string>
+
+// Enable IPC include guard convention multiple-inclusion semantics.
+#undef IPC_MESSAGE_REINCLUDE
+#define IPC_MESSAGE_REINCLUDE 1
+
+// Null out all the macros that need nulling.
+#include "ipc/ipc_message_null_macros.h"
+
+// STRUCT declarations cause corresponding STRUCT_TRAITS declarations to occur.
+#undef IPC_STRUCT_BEGIN
+#undef IPC_STRUCT_MEMBER
+#undef IPC_STRUCT_END
+#define IPC_STRUCT_BEGIN(struct_name) IPC_STRUCT_TRAITS_BEGIN(struct_name)
+#define IPC_STRUCT_MEMBER(type, name) IPC_STRUCT_TRAITS_MEMBER(name)
+#define IPC_STRUCT_END(struct_name) IPC_STRUCT_TRAITS_END(struct_name)
+
+// ENUM declarations cause corresponding ENUM_TRAITS declartions to occur.
+#undef IPC_ENUM_BEGIN
+#undef IPC_ENUM_VALUE
+#undef IPC_ENUM_VALUE
+#undef IPC_ENUM_END
+#define IPC_ENUM_BEGIN(enum_name) IPC_ENUM_TRAITS_BEGIN(enum_name)
+#define IPC_ENUM_VALUE(enum_name) IPC_ENUM_TRAITS_VALUE(enum_name)
+#define IPC_ENUM_END(enum_name) IPC_ENUM_TRAITS_END(enum_name)

[jam, 2011/02/07 20:17:01]

ditto: can we avoid listing the struct twice in IPC_ENUM_BEGIN and IPC_ENUM_END?

+
+// Set up so next include will generate log methods.
+#undef IPC_STRUCT_TRAITS_BEGIN
+#undef IPC_STRUCT_TRAITS_MEMBER
+#undef IPC_STRUCT_TRAITS_END
+#define IPC_STRUCT_TRAITS_BEGIN(struct_name) \
+  void ParamTraits<struct_name>::Log(const param_type& p, std::string* l) { \
+    bool needs_comma = false; \
+    l->append("(");
+#define IPC_STRUCT_TRAITS_MEMBER(name) \
+    if (needs_comma) \
+      l->append(", "); \
+    LogParam(p.name, l); \
+    needs_comma = true;
+#define IPC_STRUCT_TRAITS_END(struct_name) l->append(")"); }
+
+#undef IPC_ENUM_TRAITS_BEGIN
+#undef IPC_ENUM_TRAITS_VALUE
+#undef IPC_ENUM_TRAITS_END
+#define IPC_ENUM_TRAITS_BEGIN(enum_name) \
+  void ParamTraits<enum_name>::Log(const param_type& p, std::string* l) { \
+    std::string state; \
+    switch (p) {
+#define IPC_ENUM_TRAITS_VALUE(name) \
+      case name: \
+        state = #name; \
+        break;
+#define IPC_ENUM_TRAITS_END(enum_name) \
+      default: \
+        state = "INVALID " #enum_name; \
+        break; \
+    } \
+    LogParam(state, l); \
+  }
+
+#endif  // IPC_IPC_PARAM_TRAITS_LOG_MACROS_H_
+