Support C++17 fallthrough attribute

Replaces our mix of comments for annotating intended absence of break
in switches with the C++17 attribute [[fallthrough]], or its earlier
a clang extension counterpart.

Change-Id: I4b2d0b9b5e4425819c7f1bf01608093c536b6d14
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

4 files changed, 8 insertions, 6 deletions

diff --git a/src/network/access/qftp.cpp b/src/network/access/qftp.cpp
index 7b6f830333..52b9dd9169 100644
--- a/src/network/access/qftp.cpp
+++ b/src/network/access/qftp.cpp
@@ -1121,7 +1121,7 @@ bool QFtpPI::processReply()
         case Success:
             // success handling
             state = Idle;
-            // no break!
+            Q_FALLTHROUGH();
         case Idle:
             if (dtp.hasError()) {
                 emit error(QFtp::UnknownError, dtp.errorMessage());
diff --git a/src/network/access/qhttpnetworkconnectionchannel.cpp b/src/network/access/qhttpnetworkconnectionchannel.cpp
index 3a780f636b..87f88aad5f 100644
--- a/src/network/access/qhttpnetworkconnectionchannel.cpp
+++ b/src/network/access/qhttpnetworkconnectionchannel.cpp
@@ -1036,7 +1036,7 @@ void QHttpNetworkConnectionChannel::_q_encrypted()
 
     if (!protocolHandler) {
         switch (sslSocket->sslConfiguration().nextProtocolNegotiationStatus()) {
-        case QSslConfiguration::NextProtocolNegotiationNegotiated: /* fall through */
+        case QSslConfiguration::NextProtocolNegotiationNegotiated:
         case QSslConfiguration::NextProtocolNegotiationUnsupported: {
             QByteArray nextProtocol = sslSocket->sslConfiguration().nextNegotiatedProtocol();
             if (nextProtocol == QSslConfiguration::NextProtocolHttp1_1) {
@@ -1056,6 +1056,7 @@ void QHttpNetworkConnectionChannel::_q_encrypted()
                                       "detected unknown Next Protocol Negotiation protocol");
                 break;
             }
+            Q_FALLTHROUGH();
         }
         case QSslConfiguration::NextProtocolNegotiationNone:
             protocolHandler.reset(new QHttpProtocolHandler(this));
diff --git a/src/network/access/qhttpprotocolhandler.cpp b/src/network/access/qhttpprotocolhandler.cpp
index b486b75449..37e8b9bed8 100644
--- a/src/network/access/qhttpprotocolhandler.cpp
+++ b/src/network/access/qhttpprotocolhandler.cpp
@@ -99,7 +99,7 @@ void QHttpProtocolHandler::_q_receiveReply()
         switch (state) {
         case QHttpNetworkReplyPrivate::NothingDoneState: {
             m_reply->d_func()->state = QHttpNetworkReplyPrivate::ReadingStatusState;
-            // fallthrough
+            Q_FALLTHROUGH();
         }
         case QHttpNetworkReplyPrivate::ReadingStatusState: {
             qint64 statusBytes = m_reply->d_func()->readStatus(m_socket);
@@ -213,7 +213,8 @@ void QHttpProtocolHandler::_q_receiveReply()
             if (replyPrivate->state == QHttpNetworkReplyPrivate::ReadingDataState)
                 break;
 
-            // everything done, fall through
+            // everything done
+            Q_FALLTHROUGH();
             }
       case QHttpNetworkReplyPrivate::AllDoneState:
             m_channel->allDone();
@@ -428,7 +429,7 @@ bool QHttpProtocolHandler::sendRequest()
     }
     case QHttpNetworkConnectionChannel::ReadingState:
         // ignore _q_bytesWritten in these states
-        // fall through
+        Q_FALLTHROUGH();
     default:
         break;
     }
diff --git a/src/network/access/qnetworkcookie.cpp b/src/network/access/qnetworkcookie.cpp
index 7a538cbf08..b7cf989477 100644
--- a/src/network/access/qnetworkcookie.cpp
+++ b/src/network/access/qnetworkcookie.cpp
@@ -644,7 +644,7 @@ static QDateTime parseDateString(const QByteArray &dateString)
             switch (end - 1) {
             case 4:
                 minutes = atoi(dateString.mid(at + 3, 2).constData());
-                // fall through
+                Q_FALLTHROUGH();
             case 2:
                 hours = atoi(dateString.mid(at + 1, 2).constData());
                 break;