LibCore: Convert CTCPSocket to ObjectPtr, add construct() helper

The C_OBJECT macro now also inserts a static construct(...) helper into
the class. Now we can make the constructor(s) private and instead call:

    auto socket = CTCPSocket::construct(arguments);

construct() returns an ObjectPtr<T>, which we'll later switch to being
a NonnullRefPtr<T>, once everything else in in place for ref-counting.

Libraries/LibCore/CHttpJob.cpp

@@ -116,7 +116,7 @@ void CHttpJob::finish_up()
 void CHttpJob::start()
 {
     ASSERT(!m_socket);
-    m_socket = new CTCPSocket(this);
+    m_socket = CTCPSocket::construct(this);
     m_socket->on_connected = [this] {
         dbg() << "CHttpJob: on_connected callback";
         on_socket_connected();

Libraries/LibCore/CHttpJob.h

@@ -26,7 +26,7 @@ private:
     };
 
     CHttpRequest m_request;
-    CTCPSocket* m_socket { nullptr };
+    ObjectPtr<CTCPSocket> m_socket;
     State m_state { State::InStatus };
     int m_code { -1 };
     HashMap<String, String> m_headers;

Libraries/LibCore/CObject.h

@@ -1,11 +1,12 @@
 #pragma once
 
-#include <AK/String.h>
 #include <AK/Function.h>
 #include <AK/IntrusiveList.h>
 #include <AK/StdLibExtras.h>
+#include <AK/String.h>
 #include <AK/Vector.h>
 #include <AK/Weakable.h>
+#include <LibCore/ObjectPtr.h>
 
 namespace AK {
 class JsonObject;
@@ -16,9 +17,14 @@ class CChildEvent;
 class CCustomEvent;
 class CTimerEvent;
 
-#define C_OBJECT(klass) \
-public:                 \
-    virtual const char* class_name() const override { return #klass; }
+#define C_OBJECT(klass)                                                \
+public:                                                                \
+    virtual const char* class_name() const override { return #klass; } \
+    template<class... Args>                                            \
+    static inline ObjectPtr<klass> construct(Args&&... args)           \
+    {                                                                  \
+        return ObjectPtr<klass>(new klass(forward<Args>(args)...));    \
+    }
 
 class CObject : public Weakable<CObject> {
     // NOTE: No C_OBJECT macro for CObject itself.

Libraries/LibCore/CTCPServer.cpp

@@ -40,7 +40,7 @@ bool CTCPServer::listen(const IPv4Address& address, u16 port)
     return true;
 }
 
-CTCPSocket* CTCPServer::accept()
+ObjectPtr<CTCPSocket> CTCPServer::accept()
 {
     ASSERT(m_listening);
     sockaddr_in in;
@@ -51,5 +51,5 @@ CTCPSocket* CTCPServer::accept()
         return nullptr;
     }
 
-    return new CTCPSocket({}, accepted_fd);
+    return CTCPSocket::construct(accepted_fd);
 }

Libraries/LibCore/CTCPServer.h

@@ -15,7 +15,7 @@ public:
     bool is_listening() const { return m_listening; }
     bool listen(const IPv4Address& address, u16 port);
 
-    CTCPSocket* accept();
+    ObjectPtr<CTCPSocket> accept();
 
     Function<void()> on_ready_to_accept;
 

Libraries/LibCore/CTCPSocket.cpp

@@ -2,7 +2,7 @@
 #include <sys/socket.h>
 #include <errno.h>
 
-CTCPSocket::CTCPSocket(Badge<CTCPServer>, int fd, CObject* parent)
+CTCPSocket::CTCPSocket(int fd, CObject* parent)
     : CSocket(CSocket::Type::TCP, parent)
 {
     set_fd(fd);

Libraries/LibCore/CTCPSocket.h

@@ -8,7 +8,9 @@ class CTCPServer;
 class CTCPSocket final : public CSocket {
     C_OBJECT(CTCPSocket)
 public:
-    explicit CTCPSocket(CObject* parent = nullptr);
-    CTCPSocket(Badge<CTCPServer>, int fd, CObject* parent = nullptr);
     virtual ~CTCPSocket() override;
+
+private:
+    CTCPSocket(int fd, CObject* parent = nullptr);
+    explicit CTCPSocket(CObject* parent = nullptr);
 };

Libraries/LibCore/CoreIPCClient.h

@@ -47,7 +47,6 @@ namespace Client {
 
     template<typename ServerMessage, typename ClientMessage>
     class Connection : public CObject {
-        C_OBJECT(Connection)
     public:
         Connection(const StringView& address)
             : m_connection(this)
@@ -238,7 +237,6 @@ namespace Client {
 
     template<typename Endpoint>
     class ConnectionNG : public CObject {
-        C_OBJECT(Connection)
     public:
         ConnectionNG(const StringView& address)
             : m_connection(this)

Libraries/LibCore/CoreIPCServer.h

@@ -64,7 +64,6 @@ namespace Server {
 
     template<typename ServerMessage, typename ClientMessage>
     class Connection : public CObject {
-        C_OBJECT(Connection)
     public:
         Connection(CLocalSocket& socket, int client_id)
             : m_socket(socket)
@@ -206,7 +205,6 @@ namespace Server {
 
     template<typename Endpoint>
     class ConnectionNG : public CObject {
-        C_OBJECT(Connection)
     public:
         ConnectionNG(Endpoint& endpoint, CLocalSocket& socket, int client_id)
             : m_endpoint(endpoint)

Libraries/LibGUI/GEventLoop.h

@@ -11,6 +11,7 @@ class CNotifier;
 class GWindow;
 
 class GWindowServerConnection : public IPC::Client::Connection<WSAPI_ServerMessage, WSAPI_ClientMessage> {
+    C_OBJECT(GWindowServerConnection)
 public:
     GWindowServerConnection()
         : Connection("/tmp/wsportal")