shiboken2: Handle virtual methods returning a reference

Although it is a questionable practice, it occurs in Qt 6:

virtual const QEventPoint &QPointerEvent::point(int i) const;

Previously, the generated return statement

return QEventPoint();

would cause a warning about returning a temporary.
Fix by creating a static variable and returning a
reference to it.

Task-number: PYSIDE-1339
Task-number: PYSIDE-904
Change-Id: Id6467be22a166e99e8dcf08b2c7c14df33cd2786
Reviewed-by: Christian Tismer <tismer@stackless.com>

1 files changed, 5 insertions, 0 deletions

diff --git a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
index 65e12c7bc..54af34180 100644
--- a/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
+++ b/sources/shiboken2/generator/shiboken2/cppgenerator.cpp
@@ -869,6 +869,11 @@ QString CppGenerator::virtualMethodReturn(QTextStream &s,
         qCWarning(lcShiboken).noquote().nospace() << errorMsg;
         s << Qt::endl << INDENT << "#error " << errorMsg << Qt::endl;
     }
+    if (returnType->referenceType() == LValueReference) {
+        s << INDENT << "static " << returnType->typeEntry()->qualifiedCppName()
+            << " result;\n";
+        return QLatin1String("return result;");
+    }
     return QLatin1String("return ") + defaultReturnExpr.returnValue()
            + QLatin1Char(';');
 }