From 2983e63983cd3d65a9b56a642a000a088897e7c6 Mon Sep 17 00:00:00 2001
From: Vlad Zagorodniy <vladzzag@gmail.com>
Date: Sun, 1 Apr 2018 11:45:42 +0300
Subject: [PATCH] [kstyle] use Q_FALLTHROUGH in breezesplitterproxy

Summary:
Qt has its own macro to tell the compiler that the lack of the break
statement is intentional. One of the advantages of using Q_FALLTHROUGH
is that it explicitly says other developers that the break statement is
missing on purpose. Another advantage is that we can use directives,
see https://gcc.gnu.org/bugzilla/show_bug.cgi?id=77817

Test Plan:
Compiled Breeze with GCC 7 and Clang, no "this statement may fall
through" warnings whatsoever.

Reviewers: #breeze, davidedmundson

Reviewed By: davidedmundson

Subscribers: plasma-devel

Tags: #plasma

Differential Revision: https://phabricator.kde.org/D11860
---
 kstyle/breezesplitterproxy.cpp | 25 ++++++++++++++++++++++++-
 1 file changed, 24 insertions(+), 1 deletion(-)

diff --git a/kstyle/breezesplitterproxy.cpp b/kstyle/breezesplitterproxy.cpp
index 17a15880..3079c7fc 100644
--- a/kstyle/breezesplitterproxy.cpp
+++ b/kstyle/breezesplitterproxy.cpp
@@ -26,6 +26,28 @@
 #include <QDebug>
 #include <QPainter>
 
+// Q_FALLTHROUGH() for Qt < 5.8
+#ifndef Q_FALLTHROUGH
+#if defined(__has_cpp_attribute)
+#if __has_cpp_attribute(fallthrough)
+#define Q_FALLTHROUGH() [[fallthrough]]
+#elif __has_cpp_attribute(clang::fallthrough)
+#define Q_FALLTHROUGH() [[clang::fallthrough]]
+#elif __has_cpp_attribute(gnu::fallthrough)
+#define Q_FALLTHROUGH() [[gnu::fallthrough]]
+#endif
+#endif
+#ifndef Q_FALLTHROUGH
+#if defined(Q_CC_GNU) && Q_CC_GNU >= 700
+#define Q_FALLTHROUGH() __attribute__((fallthrough))
+#elif defined(Q_CC_CLANG) && Q_CC_CLANG >= 305
+#define Q_FALLTHROUGH() [[clang::fallthrough]]
+#else
+#define Q_FALLTHROUGH()
+#endif
+#endif
+#endif
+
 namespace Breeze
 {
 
@@ -269,12 +291,13 @@ namespace Breeze
             if( static_cast<QTimerEvent*>( event )->timerId() != _timerId )
             { return QWidget::event( event ); }
 
-            // fall-through
             /*
             Fall through is intended.
             We somehow lost a QEvent::Leave before timeout. We fix it from here
             */
 
+            Q_FALLTHROUGH();
+
             case QEvent::HoverLeave:
             case QEvent::Leave:
             {