add util part 4,util/linux,util/unix and modify warns

Signed-off-by: libenyao <libenyao@h-partners.com>

util/WebSocketServer.cpp

@@ -13,10 +13,10 @@
  * limitations under the License.
  */
 
+#include <thread>
 #include "CommandLineInterface.h"
 #include "PreviewerEngineLog.h"
 #include "WebSocketServer.h"
-#include <thread>
 using namespace std;
 
 lws* WebSocketServer::webSocket = nullptr;
@@ -96,7 +96,9 @@ void WebSocketServer::sigint_handler(int sig)
 
 void WebSocketServer::StartWebsocketListening()
 {
-    signal(SIGINT, sigint_handler);
+    if (signal(SIGINT, sigint_handler) == SIG_ERR) {
+        return;
+    }
     ILOG("Begin to start websocket listening!");
     struct lws_context_creation_info contextInfo = {0};
     contextInfo.port = serverPort;

util/WebSocketServer.h

@@ -17,7 +17,7 @@
 #define WEBSOCKETSERVER_H
 
 #include <thread>
-#include <signal.h>
+#include <csignal>
 #include <mutex>
 #include "libwebsockets.h"
 
@@ -34,7 +34,7 @@ public:
     void StartWebsocketListening();
     void Run();
     size_t WriteData(unsigned char* data, size_t length);
-    enum WebSocketState { INIT = -1, UNWRITEABLE = 0, WRITEABLE = 1 };
+    enum class WebSocketState { INIT = -1, UNWRITEABLE = 0, WRITEABLE = 1 };
     static WebSocketState webSocketWritable;
     static uint8_t* firstImageBuffer;
     static uint64_t firstImagebufferSize;

util/linux/ClipboardX11.cpp

@@ -39,7 +39,7 @@ const string ClipboardX11::GetClipboardData()
     int ret = DefaultScreen(display);
     window = XCreateSimpleWindow(display, RootWindow(display, ret), 0, 0, 1, 1, 0,
                                  BlackPixel(display, ret), WhitePixel(display, ret));
-    string retStr;
+    string retStr; // NOLINT
     UTF8 = XInternAtom(display, "UTF8_STRING", True);
     if (UTF8 != None) retStr = GetPasteType(UTF8);
     if (retStr.empty()) retStr = GetPasteType(XA_STRING);

util/unix/CrashHandler.cpp

@@ -28,7 +28,9 @@ using namespace std;
 
 void CrashHandler::InitExceptionHandler()
 {
-    signal(SIGSEGV, ApplicationCrashHandler);
+    if (signal(SIGSEGV, ApplicationCrashHandler) == SIG_ERR) {
+        return;
+    }
 }
 
 void CrashHandler::ApplicationCrashHandler(int signal)