QtBase (remainder): use printf-style qWarning/qDebug where possible (I)

The printf-style version of QDebug expands to a lot less code than the
std::ostream-style version. Of course, you pay in type safety (but
compilers warn about it these days), you cannot stream complex Qt
types and streaming QStrings is awkward, but in many cases you
actually improve on readability.

But the main reason is that something that's not supposed to be
executed under normal operation has no business bloating executable
code size.

This is not an attempt at converting all qWarnings() to printf-style,
only the low-hanging fruit.

In this first part, replace
   qWarning() << ""
with
   qWarning("...").

Had to fix broken qImDebug() definition. Instead of defining it as
a nullary macro in the QT_NO_DEBUG case and as a variadic macro in
the other, define it in both cases, as is customary, as a non-function
macro so that overload selection works without requiring variadic
macro support of the compiler.

Saves e.g. ~250b in text size in QtPrintSupport on optimized GCC 5.3
AMD64 builds.

Change-Id: Ie30fe2f7942115d5dbf99fff1750ae0d477c379f
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

2 files changed, 3 insertions, 3 deletions

diff --git a/src/plugins/platforms/windows/qwindowstabletsupport.cpp b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
index 8db6895999..3689978b41 100644
--- a/src/plugins/platforms/windows/qwindowstabletsupport.cpp
+++ b/src/plugins/platforms/windows/qwindowstabletsupport.cpp
@@ -208,7 +208,7 @@ QWindowsTabletSupport *QWindowsTabletSupport::create()
     if (currentQueueSize != TabletPacketQSize) {
         if (!QWindowsTabletSupport::m_winTab32DLL.wTQueueSizeSet(context, TabletPacketQSize)) {
             if (!QWindowsTabletSupport::m_winTab32DLL.wTQueueSizeSet(context, currentQueueSize))  {
-                qWarning() << "Unable to set queue size on tablet. The tablet will not work.";
+                qWarning("Unable to set queue size on tablet. The tablet will not work.");
                 QWindowsTabletSupport::m_winTab32DLL.wTClose(context);
                 DestroyWindow(window);
                 return 0;
diff --git a/src/plugins/platforms/windows/qwindowswindow.cpp b/src/plugins/platforms/windows/qwindowswindow.cpp
index d9a7586096..d1c5cccbcf 100644
--- a/src/plugins/platforms/windows/qwindowswindow.cpp
+++ b/src/plugins/platforms/windows/qwindowswindow.cpp
@@ -700,7 +700,7 @@ void WindowCreationData::initialize(const QWindow *w, HWND hwnd, bool frameChang
         if ((flags & Qt::WindowStaysOnTopHint) || (type == Qt::ToolTip)) {
             SetWindowPos(hwnd, HWND_TOPMOST, 0, 0, 0, 0, swpFlags);
             if (flags & Qt::WindowStaysOnBottomHint)
-                qWarning() << "QWidget: Incompatible window flags: the window can't be on top and on bottom at the same time";
+                qWarning("QWidget: Incompatible window flags: the window can't be on top and on bottom at the same time");
         } else if (flags & Qt::WindowStaysOnBottomHint) {
             SetWindowPos(hwnd, HWND_BOTTOM, 0, 0, 0, 0, swpFlags);
         } else if (frameChange) { // Force WM_NCCALCSIZE with wParam=1 in case of custom margins.
@@ -2213,7 +2213,7 @@ void QWindowsWindow::getSizeHints(MINMAXINFO *mmi) const
             mmi->ptMaxPosition.x = availableGeometry.x();
             mmi->ptMaxPosition.y = availableGeometry.y();
         } else if (!screen){
-            qWarning() << "window()->screen() returned a null screen";
+            qWarning("window()->screen() returned a null screen");
         }
     }