Static plugins - mangle entry point

Namespaced qt should be protected against duplicate symbols in the same
process/dso. The static plugin factory had a flat name, so we should
name-mangle it.

[ChangeLog] In namespaced builds the entry function for static plugins
now appends the namespace via QT_MANGLE_NAMESPACE.

Task-number: QTBUG-138543
Pick-to: 6.10
Change-Id: Ic656a4fd27d5a3d2b2209ef553c34e75024acc3b
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

Author: timblechmann

src/corelib/plugin/qplugin.h

@@ -192,11 +192,11 @@ template <auto (&PluginMetaData)> class QPluginMetaDataV2
 };
 
 #define Q_IMPORT_PLUGIN(PLUGIN) \
-        extern const QT_PREPEND_NAMESPACE(QStaticPlugin) qt_static_plugin_##PLUGIN(); \
+        extern const QT_PREPEND_NAMESPACE(QStaticPlugin) QT_MANGLE_NAMESPACE(qt_static_plugin_##PLUGIN)(); \
         class Static##PLUGIN##PluginInstance{ \
         public: \
                 Static##PLUGIN##PluginInstance() { \
-                    qRegisterStaticPluginFunction(qt_static_plugin_##PLUGIN()); \
+                    qRegisterStaticPluginFunction(QT_MANGLE_NAMESPACE(qt_static_plugin_##PLUGIN)()); \
                 } \
         }; \
        static Static##PLUGIN##PluginInstance static##PLUGIN##Instance;
@@ -220,11 +220,11 @@ template <auto (&PluginMetaData)> class QPluginMetaDataV2
         }
 
 #if defined(QT_STATICPLUGIN)
-#  define QT_MOC_EXPORT_PLUGIN_COMMON(PLUGINCLASS, MANGLEDNAME)                                 \
-    static QT_PREPEND_NAMESPACE(QObject) *qt_plugin_instance_##MANGLEDNAME()                    \
-    Q_PLUGIN_INSTANCE(PLUGINCLASS)                                                              \
-    const QT_PREPEND_NAMESPACE(QStaticPlugin) qt_static_plugin_##MANGLEDNAME()                  \
-    { return { qt_plugin_instance_##MANGLEDNAME, qt_plugin_query_metadata_##MANGLEDNAME}; }     \
+#  define QT_MOC_EXPORT_PLUGIN_COMMON(PLUGINCLASS, MANGLEDNAME)                                     \
+    static QT_PREPEND_NAMESPACE(QObject) *qt_plugin_instance_##MANGLEDNAME()                        \
+    Q_PLUGIN_INSTANCE(PLUGINCLASS)                                                                  \
+    const QT_PREPEND_NAMESPACE(QStaticPlugin) QT_MANGLE_NAMESPACE(qt_static_plugin_##MANGLEDNAME)() \
+    { return { qt_plugin_instance_##MANGLEDNAME, qt_plugin_query_metadata_##MANGLEDNAME}; }         \
     /**/
 
 #  define QT_MOC_EXPORT_PLUGIN(PLUGINCLASS, PLUGINCLASSNAME) \

tests/auto/corelib/plugin/qpluginloader/tst_qpluginloader.cpp

@@ -1160,12 +1160,12 @@ void tst_QPluginLoader::staticPlugins()
 void tst_QPluginLoader::reregisteredStaticPlugins()
 {
     // the Q_IMPORT_PLUGIN macro will have already done this
-    qRegisterStaticPluginFunction(qt_static_plugin_StaticPlugin());
+    qRegisterStaticPluginFunction(QT_MANGLE_NAMESPACE(qt_static_plugin_StaticPlugin)());
     staticPlugins();
     if (QTest::currentTestFailed())
         return;
 
-    qRegisterStaticPluginFunction(qt_static_plugin_StaticPlugin());
+    qRegisterStaticPluginFunction(QT_MANGLE_NAMESPACE(qt_static_plugin_StaticPlugin)());
     staticPlugins();
 }