Annotate more implicit fallthroughs

Reduces our number of gcc 7 warnings

Change-Id: I792d658cbc11cad15cf45da3a36fc93fcdcc67ea
Reviewed-by: Marc Mutz <marc.mutz@kdab.com>

src/gui/painting/qdrawhelper.cpp

@@ -5980,13 +5980,13 @@ inline void qt_memfill_template(T *dest, T color, int count)
     int n = (count + 7) / 8;
     switch (count & 0x07)
     {
-    case 0: do { *dest++ = color;
-    case 7:      *dest++ = color;
-    case 6:      *dest++ = color;
-    case 5:      *dest++ = color;
-    case 4:      *dest++ = color;
-    case 3:      *dest++ = color;
-    case 2:      *dest++ = color;
+    case 0: do { *dest++ = color; Q_FALLTHROUGH();
+    case 7:      *dest++ = color; Q_FALLTHROUGH();
+    case 6:      *dest++ = color; Q_FALLTHROUGH();
+    case 5:      *dest++ = color; Q_FALLTHROUGH();
+    case 4:      *dest++ = color; Q_FALLTHROUGH();
+    case 3:      *dest++ = color; Q_FALLTHROUGH();
+    case 2:      *dest++ = color; Q_FALLTHROUGH();
     case 1:      *dest++ = color;
     } while (--n > 0);
     }
@@ -5997,7 +5997,7 @@ inline void qt_memfill_template(quint16 *dest, quint16 value, int count)
 {
     if (count < 3) {
         switch (count) {
-        case 2: *dest++ = value;
+        case 2: *dest++ = value; Q_FALLTHROUGH();
         case 1: *dest = value;
         }
         return;

src/gui/painting/qdrawhelper_sse2.cpp

@@ -237,11 +237,11 @@ void qt_memfill32(quint32 *dest, quint32 value, int count)
 {
     if (count < 7) {
         switch (count) {
-        case 6: *dest++ = value;
-        case 5: *dest++ = value;
-        case 4: *dest++ = value;
-        case 3: *dest++ = value;
-        case 2: *dest++ = value;
+        case 6: *dest++ = value; Q_FALLTHROUGH();
+        case 5: *dest++ = value; Q_FALLTHROUGH();
+        case 4: *dest++ = value; Q_FALLTHROUGH();
+        case 3: *dest++ = value; Q_FALLTHROUGH();
+        case 2: *dest++ = value; Q_FALLTHROUGH();
         case 1: *dest   = value;
         }
         return;
@@ -249,16 +249,16 @@ void qt_memfill32(quint32 *dest, quint32 value, int count)
 
     const int align = (quintptr)(dest) & 0xf;
     switch (align) {
-    case 4:  *dest++ = value; --count;
-    case 8:  *dest++ = value; --count;
+    case 4:  *dest++ = value; --count; Q_FALLTHROUGH();
+    case 8:  *dest++ = value; --count; Q_FALLTHROUGH();
     case 12: *dest++ = value; --count;
     }
 
     const int rest = count & 0x3;
     if (rest) {
         switch (rest) {
-        case 3: dest[count - 3] = value;
-        case 2: dest[count - 2] = value;
+        case 3: dest[count - 3] = value; Q_FALLTHROUGH();
+        case 2: dest[count - 2] = value; Q_FALLTHROUGH();
         case 1: dest[count - 1] = value;
         }
     }
@@ -277,8 +277,8 @@ void qt_memfill32(quint32 *dest, quint32 value, int count)
     }
 
     switch (count128 & 0x3) {
-    case 3:      _mm_stream_si128(dst128++, value128);
-    case 2:      _mm_stream_si128(dst128++, value128);
+    case 3:      _mm_stream_si128(dst128++, value128); Q_FALLTHROUGH();
+    case 2:      _mm_stream_si128(dst128++, value128); Q_FALLTHROUGH();
     case 1:      _mm_stream_si128(dst128++, value128);
     }
 }
@@ -318,7 +318,7 @@ void qt_memfill16(quint16 *dest, quint16 value, int count)
 {
     if (count < 3) {
         switch (count) {
-        case 2: *dest++ = value;
+        case 2: *dest++ = value; Q_FALLTHROUGH();
         case 1: *dest = value;
         }
         return;

src/printsupport/kernel/qcups.cpp

@@ -101,6 +101,7 @@ static inline QString jobHoldToString(const QCUPSSupport::JobHoldUntil jobHold,
             return localDateTime.toUTC().time().toString(QStringLiteral("HH:mm"));
         }
         // else fall through:
+        Q_FALLTHROUGH();
     case QCUPSSupport::NoHold:
         return QString();
     }

src/widgets/accessible/itemviews.cpp

@@ -310,6 +310,7 @@ bool QAccessibleTable::selectColumn(int column)
     case QAbstractItemView::SingleSelection:
         if (view()->selectionBehavior() != QAbstractItemView::SelectColumns && rowCount() > 1)
             return false;
+        Q_FALLTHROUGH();
     case QAbstractItemView::ContiguousSelection:
         if ((!column || !view()->selectionModel()->isColumnSelected(column - 1, view()->rootIndex()))
             && !view()->selectionModel()->isColumnSelected(column + 1, view()->rootIndex()))

src/widgets/graphicsview/qgraphicswidget.cpp

@@ -1500,6 +1500,7 @@ void QGraphicsWidget::changeEvent(QEvent *event)
         unsetWindowFrameMargins();
         if (d->layout)
             d->layout->invalidate();
+        Q_FALLTHROUGH();
     case QEvent::FontChange:
         update();
         updateGeometry();

src/widgets/itemviews/qabstractitemview.cpp

@@ -4035,6 +4035,7 @@ QItemSelectionModel::SelectionFlags QAbstractItemViewPrivate::extendedSelectionC
             switch (static_cast<const QKeyEvent*>(event)->key()) {
             case Qt::Key_Backtab:
                 modifiers = modifiers & ~Qt::ShiftModifier; // special case for backtab
+                Q_FALLTHROUGH();
             case Qt::Key_Down:
             case Qt::Key_Up:
             case Qt::Key_Left:

src/widgets/itemviews/qheaderview.cpp

@@ -2558,6 +2558,7 @@ void QHeaderView::mouseReleaseEvent(QMouseEvent *e)
             d->updateSectionIndicator(d->section, pos);
             break;
         } // not moving
+        Q_FALLTHROUGH();
     case QHeaderViewPrivate::SelectSections:
         if (!d->clickableSections) {
             int section = logicalIndexAt(pos);

src/widgets/itemviews/qlistview.cpp

@@ -1157,6 +1157,7 @@ QModelIndex QListView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifie
         rect.moveTop(rect.top() - d->viewport->height() + 2 * rect.height());
         if (rect.top() < rect.height())
             rect.moveTop(rect.height());
+        Q_FALLTHROUGH();
     case MovePrevious:
     case MoveUp:
         while (intersectVector.isEmpty()) {
@@ -1185,6 +1186,7 @@ QModelIndex QListView::moveCursor(CursorAction cursorAction, Qt::KeyboardModifie
         rect.moveTop(rect.top() + d->viewport->height() - 2 * rect.height());
         if (rect.bottom() > contents.height() - rect.height())
             rect.moveBottom(contents.height() - rect.height());
+        Q_FALLTHROUGH();
     case MoveNext:
     case MoveDown:
         while (intersectVector.isEmpty()) {