Userland: Split IPC endpoints into proxies and stubs

This enables support for automatically generating client methods.
With this added the user gets code completion support for all
IPC methods which are available on a connection object.

Userland/DevTools/HackStudio/LanguageServers/ClientConnection.h

@@ -20,8 +20,7 @@ namespace LanguageServers {
 
 class ClientConnection
     : public IPC::ClientConnection<LanguageClientEndpoint, LanguageServerEndpoint>
-    , public LanguageServerEndpoint {
-
+{
 public:
     explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id);
     ~ClientConnection() override;

Userland/DevTools/IPCCompiler/main.cpp

@@ -60,6 +60,25 @@ static String snake_case(String const& identifier)
     return builder.to_string();
 }
 
+bool is_primitive_type(String const& type)
+{
+    return (type == "u8" || type == "i8" || type == "u16" || type == "i16"
+        || type == "u32" || type == "i32" || type == "bool" || type == "double"
+        || type == "float" || type == "int" || type == "unsigned" || type == "unsigned int");
+}
+
+String message_name(String const& endpoint, String& message, bool is_response)
+{
+    StringBuilder builder;
+    builder.append("Messages::");
+    builder.append(endpoint);
+    builder.append("::");
+    builder.append(message);
+    if (is_response)
+        builder.append("Response");
+    return builder.to_string();
+}
+
 int main(int argc, char** argv)
 {
     if (argc != 2) {
@@ -231,10 +250,11 @@ int main(int argc, char** argv)
 #include <LibGfx/Color.h>
 #include <LibGfx/Rect.h>
 #include <LibGfx/ShareableBitmap.h>
+#include <LibIPC/Connection.h>
 #include <LibIPC/Decoder.h>
 #include <LibIPC/Dictionary.h>
 #include <LibIPC/Encoder.h>
-#include <LibIPC/Endpoint.h>
+#include <LibIPC/Stub.h>
 #include <LibIPC/File.h>
 #include <LibIPC/Message.h>
 )~~~");
@@ -329,6 +349,9 @@ public:
 
             message_generator.append(R"~~~(
     @message.name@(decltype(nullptr)) : m_ipc_message_valid(false) { }
+    @message.name@(@message.name@ const&) = default;
+    @message.name@(@message.name@&&) = default;
+    @message.name@& operator=(@message.name@ const&) = default;
     @message.constructor@
     virtual ~@message.name@() override {}
 
@@ -452,15 +475,109 @@ private:
         )~~~");
 
         endpoint_generator.append(R"~~~(
-class @endpoint.name@Endpoint : public IPC::Endpoint {
+template<typename LocalEndpoint, typename PeerEndpoint>
+class @endpoint.name@Proxy {
 public:
-    @endpoint.name@Endpoint() { }
-    virtual ~@endpoint.name@Endpoint() override { }
+    // Used to disambiguate the constructor call.
+    struct Tag { };
+
+    @endpoint.name@Proxy(IPC::Connection<LocalEndpoint, PeerEndpoint>& connection, Tag)
+        : m_connection(connection)
+    { }
+)~~~");
+
+        for (auto& message : endpoint.messages) {
+            auto message_generator = endpoint_generator.fork();
+
+            auto do_implement_proxy = [&](String const& name, Vector<Parameter> const& parameters, bool is_synchronous) {
+                String return_type = "void";
+                if (is_synchronous && !message.outputs.is_empty())
+                    return_type = message_name(endpoint.name, message.name, true);
+                message_generator.set("message.name", message.name);
+                message_generator.set("message.complex_return_type", return_type);
+                message_generator.set("async_prefix_maybe", is_synchronous ? "" : "async_");
+
+                message_generator.set("handler_name", snake_case(name));
+                message_generator.append(R"~~~(
+    @message.complex_return_type@ @async_prefix_maybe@@handler_name@()~~~");
+
+                for (size_t i = 0; i < parameters.size(); ++i) {
+                    auto& parameter = parameters[i];
+                    auto argument_generator = message_generator.fork();
+                    argument_generator.set("argument.type", parameter.type);
+                    argument_generator.set("argument.name", parameter.name);
+                    argument_generator.append("@argument.type@ @argument.name@");
+                    if (i != parameters.size() - 1)
+                        argument_generator.append(", ");
+                }
+
+                message_generator.append(") {");
+
+                if (is_synchronous) {
+                    if (return_type != "void") {
+                        message_generator.append(R"~~~(
+        return move(*)~~~");
+                    } else{
+                        message_generator.append(R"~~~(
+        )~~~");
+                    }
+
+                    message_generator.append("m_connection.template send_sync<Messages::@endpoint.name@::@message.name@>(");
+                } else {
+                    message_generator.append(R"~~~(
+        m_connection.post_message(Messages::@endpoint.name@::@message.name@ { )~~~");
+                }
+
+                for (size_t i = 0; i < parameters.size(); ++i) {
+                    auto& parameter = parameters[i];
+                    auto argument_generator = message_generator.fork();
+                    argument_generator.set("argument.name", parameter.name);
+                    if (is_primitive_type(parameters[i].type))
+                        argument_generator.append("@argument.name@");
+                    else
+                        argument_generator.append("move(@argument.name@)");
+                    if (i != parameters.size() - 1)
+                        argument_generator.append(", ");
+                }
+
+                if (is_synchronous) {
+                    if (return_type != "void") {
+                        message_generator.append(")");
+                    }
+
+                    message_generator.append(R"~~~();
+    }
+)~~~");
+                } else {
+                    message_generator.append(R"~~~( });
+    }
+)~~~");
+                }
+            };
+
+            do_implement_proxy(message.name, message.inputs, message.is_synchronous);
+            if (message.is_synchronous)
+                do_implement_proxy(message.name, message.inputs, false);
+        }
+
+        endpoint_generator.append(R"~~~(
+private:
+    IPC::Connection<LocalEndpoint, PeerEndpoint>& m_connection;
+};
+)~~~");
+
+        endpoint_generator.append(R"~~~(
+template<typename LocalEndpoint, typename PeerEndpoint>
+class @endpoint.name@Proxy;
+class @endpoint.name@Stub;
+
+class @endpoint.name@Endpoint {
+public:
+    template<typename LocalEndpoint>
+    using Proxy = @endpoint.name@Proxy<LocalEndpoint, @endpoint.name@Endpoint>;
+    using Stub = @endpoint.name@Stub;
 
     static u32 static_magic() { return @endpoint.magic@; }
-    virtual u32 magic() const override { return @endpoint.magic@; }
-    static String static_name() { return "@endpoint.name@"; }
-    virtual String name() const override { return "@endpoint.name@"; }
 
     static OwnPtr<IPC::Message> decode_message(ReadonlyBytes buffer, int sockfd)
     {
@@ -550,6 +667,16 @@ public:
         return message;
     }
 
+};
+
+class @endpoint.name@Stub : public IPC::Stub {
+public:
+    @endpoint.name@Stub() { }
+    virtual ~@endpoint.name@Stub() override { }
+
+    virtual u32 magic() const override { return @endpoint.magic@; }
+    virtual String name() const override { return "@endpoint.name@"; }
+
     virtual OwnPtr<IPC::MessageBuffer> handle(const IPC::Message& message) override
     {
         switch (message.message_id()) {
@@ -619,15 +746,8 @@ public:
 
             auto do_handle_message_decl = [&](String const& name, Vector<Parameter> const& parameters, bool is_response) {
                 String return_type = "void";
-                if (message.is_synchronous && !message.outputs.is_empty() && !is_response) {
-                    StringBuilder builder;
-                    builder.append("Messages::");
-                    builder.append(endpoint.name);
-                    builder.append("::");
-                    builder.append(message.name);
-                    builder.append("Response");
-                    return_type = builder.to_string();
-                }
+                if (message.is_synchronous && !message.outputs.is_empty() && !is_response)
+                    return_type = message_name(endpoint.name, message.name, true);
                 message_generator.set("message.complex_return_type", return_type);
 
                 message_generator.set("handler_name", snake_case(name));
@@ -637,11 +757,7 @@ public:
                 auto make_argument_type = [](String const& type) {
                     StringBuilder builder;
 
-                    bool const_ref = true;
-                    if (type == "u8" || type == "i8" || type == "u16" || type == "i16"
-                        || type == "u32" || type == "i32" || type == "bool" || type == "double"
-                        || type == "float" || type == "int" || type == "unsigned" || type == "unsigned int")
-                        const_ref = false;
+                    bool const_ref = !is_primitive_type(type);
 
                     builder.append(type);
                     if (const_ref)

Userland/Libraries/LibIPC/CMakeLists.txt

@@ -1,8 +1,8 @@
 set(SOURCES
     Decoder.cpp
     Encoder.cpp
-    Endpoint.cpp
     Message.cpp
+    Stub.cpp
 )
 
 serenity_lib(LibIPC ipc)

Userland/Libraries/LibIPC/ClientConnection.h

@@ -17,10 +17,13 @@ NonnullRefPtr<T> new_client_connection(Args&&... args)
 }
 
 template<typename ClientEndpoint, typename ServerEndpoint>
-class ClientConnection : public Connection<ServerEndpoint, ClientEndpoint> {
+class ClientConnection : public Connection<ServerEndpoint, ClientEndpoint>, public ServerEndpoint::Stub {
 public:
-    ClientConnection(ServerEndpoint& endpoint, NonnullRefPtr<Core::LocalSocket> socket, int client_id)
-        : IPC::Connection<ServerEndpoint, ClientEndpoint>(endpoint, move(socket))
+    using ClientProxy = typename ClientEndpoint::Proxy;
+    using ServerStub = typename ServerEndpoint::Stub;
+
+    ClientConnection(ServerStub& stub, NonnullRefPtr<Core::LocalSocket> socket, int client_id)
+        : IPC::Connection<ServerEndpoint, ClientEndpoint>(stub, move(socket))
         , m_client_id(client_id)
     {
         VERIFY(this->socket().is_connected());

Userland/Libraries/LibIPC/Connection.h

@@ -28,8 +28,11 @@ namespace IPC {
 template<typename LocalEndpoint, typename PeerEndpoint>
 class Connection : public Core::Object {
 public:
-    Connection(LocalEndpoint& local_endpoint, NonnullRefPtr<Core::LocalSocket> socket)
-        : m_local_endpoint(local_endpoint)
+    using LocalStub = typename LocalEndpoint::Stub;
+    using PeerProxy = typename PeerEndpoint::Proxy;
+
+    Connection(LocalStub& local_stub, NonnullRefPtr<Core::LocalSocket> socket)
+        : m_local_stub(local_stub)
         , m_socket(move(socket))
         , m_notifier(Core::Notifier::construct(m_socket->fd(), Core::Notifier::Read, this))
     {
@@ -248,13 +251,13 @@ protected:
         auto messages = move(m_unprocessed_messages);
         for (auto& message : messages) {
             if (message.endpoint_magic() == LocalEndpoint::static_magic())
-                if (auto response = m_local_endpoint.handle(message))
+                if (auto response = m_local_stub.handle(message))
                     post_message(*response);
         }
     }
 
 protected:
-    LocalEndpoint& m_local_endpoint;
+    LocalStub& m_local_stub;
     NonnullRefPtr<Core::LocalSocket> m_socket;
     RefPtr<Core::Timer> m_responsiveness_timer;
 

Userland/Libraries/LibIPC/ServerConnection.h

@@ -11,9 +11,12 @@
 namespace IPC {
 
 template<typename ClientEndpoint, typename ServerEndpoint>
-class ServerConnection : public IPC::Connection<ClientEndpoint, ServerEndpoint> {
+class ServerConnection : public IPC::Connection<ClientEndpoint, ServerEndpoint>, public ClientEndpoint::Stub {
 public:
-    ServerConnection(ClientEndpoint& local_endpoint, const StringView& address)
+    using ClientStub = typename ClientEndpoint::Stub;
+    using ServerProxy = typename ServerEndpoint::Proxy;
+
+    ServerConnection(ClientStub& local_endpoint, const StringView& address)
         : Connection<ClientEndpoint, ServerEndpoint>(local_endpoint, Core::LocalSocket::construct())
     {
         // We want to rate-limit our clients

Userland/Libraries/LibIPC/Stub.cpp

@@ -4,15 +4,15 @@
  * SPDX-License-Identifier: BSD-2-Clause
  */
 
-#include <LibIPC/Endpoint.h>
+#include <LibIPC/Stub.h>
 
 namespace IPC {
 
-Endpoint::Endpoint()
+Stub::Stub()
 {
 }
 
-Endpoint::~Endpoint()
+Stub::~Stub()
 {
 }
 

Userland/Libraries/LibIPC/Stub.h

@@ -18,16 +18,16 @@ namespace IPC {
 class Message;
 class MessageBuffer;
 
-class Endpoint {
+class Stub {
 public:
-    virtual ~Endpoint();
+    virtual ~Stub();
 
     virtual u32 magic() const = 0;
     virtual String name() const = 0;
     virtual OwnPtr<MessageBuffer> handle(const Message&) = 0;
 
 protected:
-    Endpoint();
+    Stub();
 
 private:
     String m_name;

Userland/Services/AudioServer/ClientConnection.h

@@ -21,7 +21,7 @@ class BufferQueue;
 class Mixer;
 
 class ClientConnection final : public IPC::ClientConnection<AudioClientEndpoint, AudioServerEndpoint>
-    , public AudioServerEndpoint {
+{
     C_OBJECT(ClientConnection)
 public:
     explicit ClientConnection(NonnullRefPtr<Core::LocalSocket>, int client_id, Mixer& mixer);

Userland/Services/Clipboard/ClientConnection.h

@@ -15,8 +15,7 @@ namespace Clipboard {
 
 class ClientConnection final
     : public IPC::ClientConnection<ClipboardClientEndpoint, ClipboardServerEndpoint>
-    , public ClipboardServerEndpoint {
-
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/ImageDecoder/ClientConnection.h

@@ -17,7 +17,7 @@ namespace ImageDecoder {
 
 class ClientConnection final
     : public IPC::ClientConnection<ImageDecoderClientEndpoint, ImageDecoderServerEndpoint>
-    , public ImageDecoderServerEndpoint {
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/LaunchServer/ClientConnection.h

@@ -13,7 +13,7 @@
 namespace LaunchServer {
 
 class ClientConnection final : public IPC::ClientConnection<LaunchClientEndpoint, LaunchServerEndpoint>
-    , public LaunchServerEndpoint {
+{
     C_OBJECT(ClientConnection)
 public:
     ~ClientConnection() override;

Userland/Services/LookupServer/ClientConnection.h

@@ -15,8 +15,7 @@ namespace LookupServer {
 
 class ClientConnection final
     : public IPC::ClientConnection<LookupClientEndpoint, LookupServerEndpoint>
-    , public LookupServerEndpoint {
-
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/NotificationServer/ClientConnection.h

@@ -13,7 +13,7 @@
 namespace NotificationServer {
 
 class ClientConnection final : public IPC::ClientConnection<NotificationClientEndpoint, NotificationServerEndpoint>
-    , public NotificationServerEndpoint {
+{
     C_OBJECT(ClientConnection)
 public:
     ~ClientConnection() override;

Userland/Services/RequestServer/ClientConnection.h

@@ -16,7 +16,7 @@ namespace RequestServer {
 
 class ClientConnection final
     : public IPC::ClientConnection<RequestClientEndpoint, RequestServerEndpoint>
-    , public RequestServerEndpoint {
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/SymbolServer/ClientConnection.h

@@ -17,7 +17,7 @@ namespace SymbolServer {
 
 class ClientConnection final
     : public IPC::ClientConnection<SymbolClientEndpoint, SymbolServerEndpoint>
-    , public SymbolServerEndpoint {
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/WebContent/ClientConnection.h

@@ -20,7 +20,7 @@ namespace WebContent {
 
 class ClientConnection final
     : public IPC::ClientConnection<WebContentClientEndpoint, WebContentServerEndpoint>
-    , public WebContentServerEndpoint {
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/WebSocket/ClientConnection.h

@@ -16,7 +16,7 @@ namespace WebSocket {
 
 class ClientConnection final
     : public IPC::ClientConnection<WebSocketClientEndpoint, WebSocketServerEndpoint>
-    , public WebSocketServerEndpoint {
+{
     C_OBJECT(ClientConnection);
 
 public:

Userland/Services/WindowServer/ClientConnection.h

@@ -29,7 +29,7 @@ class WMClientConnection;
 
 class ClientConnection final
     : public IPC::ClientConnection<WindowClientEndpoint, WindowServerEndpoint>
-    , public WindowServerEndpoint {
+{
     C_OBJECT(ClientConnection)
 public:
     ~ClientConnection() override;

Userland/Services/WindowServer/WMClientConnection.h

@@ -16,7 +16,7 @@ namespace WindowServer {
 
 class WMClientConnection final
     : public IPC::ClientConnection<WindowManagerClientEndpoint, WindowManagerServerEndpoint>
-    , public WindowManagerServerEndpoint {
+{
     C_OBJECT(WMClientConnection)
 
 public: