QtGui: 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("...");

In QTransform shared warning strings.

Saves 3KiB in text size on optimized GCC 5.3 AMD64 builds.

Change-Id: I142a8020eaab043d78465178192f2c8c6d1cc4f9
Reviewed-by: Friedemann Kleint <Friedemann.Kleint@theqtcompany.com>
Reviewed-by: Kai Koehne <kai.koehne@theqtcompany.com>

1 files changed, 1 insertions, 1 deletions

diff --git a/src/gui/kernel/qstylehints.cpp b/src/gui/kernel/qstylehints.cpp
index e184fed275..ecc2886a04 100644
--- a/src/gui/kernel/qstylehints.cpp
+++ b/src/gui/kernel/qstylehints.cpp
@@ -54,7 +54,7 @@ static inline QVariant themeableHint(QPlatformTheme::ThemeHint th,
                                      QPlatformIntegration::StyleHint ih)
 {
     if (!QCoreApplication::instance()) {
-        qWarning() << "Must construct a QGuiApplication before accessing a platform theme hint.";
+        qWarning("Must construct a QGuiApplication before accessing a platform theme hint.");
         return QVariant();
     }
     if (const QPlatformTheme *theme = QGuiApplicationPrivate::platformTheme()) {