uic: Avoid use of Q_UNUSED in the generated code

Instead, use (void)x; directly.

The current use of Q_UNUSED(x); generates warnings for an
empty statement the expansion of Q_UNUSED contains a semicolon
already.

Emitting Q_UNUSED(x) without the extra semicolon would be
an option, too, but as the future of Q_UNUSED's embedded
semicolon seems unclear right now, avoid its use altogether.

The change affects only generated code that's barely ever
read by a human, so the overall utility of "improved readability"
of Q_UNUSED in that place is questionable anyway.

Change-Id: I332527ed7c202f779bd82290517837e3ecf09a08
Reviewed-by: Jarek Kobus <jaroslaw.kobus@qt.io>

2 files changed, 4 insertions, 3 deletions

diff --git a/src/tools/uic/cpp/cppwriteinitialization.cpp b/src/tools/uic/cpp/cppwriteinitialization.cpp
index d16c859eed..fd5f8c9017 100644
--- a/src/tools/uic/cpp/cppwriteinitialization.cpp
+++ b/src/tools/uic/cpp/cppwriteinitialization.cpp
@@ -547,10 +547,11 @@ void WriteInitialization::acceptUI(DomUI *node)
     m_output << m_option.indent << language::endFunctionDefinition("setupUi");
 
     if (!m_mainFormUsedInRetranslateUi && language::language() == Language::Cpp) {
+        // Mark varName as unused to avoid compiler warnings.
         m_refreshInitialization += m_indent;
-        m_refreshInitialization += QLatin1String("Q_UNUSED(");
+        m_refreshInitialization += QLatin1String("(void)");
         m_refreshInitialization += varName ;
-        m_refreshInitialization += QLatin1String(");\n");
+        m_refreshInitialization += QLatin1String(";\n");
     }
 
     m_output << m_option.indent
diff --git a/tests/auto/tools/uic/baseline/qfiledialog.ui.h b/tests/auto/tools/uic/baseline/qfiledialog.ui.h
index 9e51ee6a7c..52f8d25c75 100644
--- a/tests/auto/tools/uic/baseline/qfiledialog.ui.h
+++ b/tests/auto/tools/uic/baseline/qfiledialog.ui.h
@@ -291,7 +291,7 @@ public:
         detailModeButton->setToolTip(QCoreApplication::translate("QFileDialog", "Detail View", nullptr));
 #endif // QT_CONFIG(tooltip)
         fileTypeLabel->setText(QCoreApplication::translate("QFileDialog", "Files of type:", nullptr));
-        Q_UNUSED(QFileDialog);
+        (void)QFileDialog;
     } // retranslateUi
 
 };