Allow loading of static plugins if QT_NO_LIBRARY is set.

We keep two symbols from QPluginLoader defined, even if QT_NO_LIBRARY
is set in order to be able to locate static plugins. This doesn't
constitute any loading of shared libraries or plugins from external
files at runtime.

Using these symbols we can enable most of QFactoryLoader even if
QT_NO_LIBRARY is set. Only update(), refreshAll(), library() and
the dtor make no sense then. This way QGenericPlugin also becomes
useful with QT_NO_LIBRARY.

Task-number: QTBUG-3045
Change-Id: Ib7842ce5799e8e2caa46431d95fddd1adda0fc41
Reviewed-by: Thiago Macieira <thiago.macieira@intel.com>

10 files changed, 77 insertions, 44 deletions

diff --git a/src/corelib/plugin/qfactoryloader.cpp b/src/corelib/plugin/qfactoryloader.cpp
index daecf0d3b0..f7545b5bcb 100644
--- a/src/corelib/plugin/qfactoryloader.cpp
+++ b/src/corelib/plugin/qfactoryloader.cpp
@@ -33,7 +33,7 @@
 
 #include "qfactoryloader_p.h"
 
-#ifndef QT_NO_LIBRARY
+#ifndef QT_NO_QOBJECT
 #include "qfactoryinterface.h"
 #include "qmap.h"
 #include <qdir.h>
@@ -66,6 +66,7 @@ class QFactoryLoaderPrivate : public QObjectPrivate
 public:
     QFactoryLoaderPrivate(){}
     QByteArray iid;
+#ifndef QT_NO_LIBRARY
     ~QFactoryLoaderPrivate();
     mutable QMutex mutex;
     QList<QLibraryPrivate*> libraryList;
@@ -73,8 +74,11 @@ public:
     QString suffix;
     Qt::CaseSensitivity cs;
     QStringList loadedPaths;
+#endif
 };
 
+#ifndef QT_NO_LIBRARY
+
 Q_GLOBAL_STATIC(QList<QFactoryLoader *>, qt_factory_loaders)
 
 Q_GLOBAL_STATIC_WITH_ARGS(QMutex, qt_factoryloader_mutex, (QMutex::Recursive))
@@ -226,6 +230,8 @@ void QFactoryLoader::refreshAll()
     }
 }
 
+#endif // QT_NO_LIBRARY
+
 QFactoryLoader::QFactoryLoader(const char *iid,
                                const QString &suffix,
                                Qt::CaseSensitivity cs)
@@ -234,21 +240,28 @@ QFactoryLoader::QFactoryLoader(const char *iid,
     moveToThread(QCoreApplicationPrivate::mainThread());
     Q_D(QFactoryLoader);
     d->iid = iid;
+#ifndef QT_NO_LIBRARY
     d->cs = cs;
     d->suffix = suffix;
 
     QMutexLocker locker(qt_factoryloader_mutex());
     update();
     qt_factory_loaders()->append(this);
+#else
+    Q_UNUSED(suffix);
+    Q_UNUSED(cs);
+#endif
 }
 
 QList<QJsonObject> QFactoryLoader::metaData() const
 {
     Q_D(const QFactoryLoader);
     QList<QJsonObject> metaData;
+#ifndef QT_NO_LIBRARY
     QMutexLocker locker(&d->mutex);
     for (int i = 0; i < d->libraryList.size(); ++i)
         metaData.append(d->libraryList.at(i)->metaData);
+#endif
 
     foreach (const QStaticPlugin &plugin, QPluginLoader::staticPlugins()) {
         const QJsonObject object = plugin.metaData();
@@ -265,6 +278,7 @@ QObject *QFactoryLoader::instance(int index) const
     if (index < 0)
         return 0;
 
+#ifndef QT_NO_LIBRARY
     if (index < d->libraryList.size()) {
         QLibraryPrivate *library = d->libraryList.at(index);
         if (library->instance || library->loadPlugin()) {
@@ -280,6 +294,7 @@ QObject *QFactoryLoader::instance(int index) const
         return 0;
     }
     index -= d->libraryList.size();
+#endif
 
     QVector<QStaticPlugin> staticPlugins = QPluginLoader::staticPlugins();
     for (int i = 0; i < staticPlugins.count(); ++i) {
@@ -330,4 +345,4 @@ int QFactoryLoader::indexOf(const QString &needle) const
 
 QT_END_NAMESPACE
 
-#endif // QT_NO_LIBRARY
+#endif // QT_NO_QOBJECT
diff --git a/src/corelib/plugin/qfactoryloader_p.h b/src/corelib/plugin/qfactoryloader_p.h
index 1c48491b0d..ee07084180 100644
--- a/src/corelib/plugin/qfactoryloader_p.h
+++ b/src/corelib/plugin/qfactoryloader_p.h
@@ -45,17 +45,18 @@
 // We mean it.
 //
 
+#include "QtCore/qglobal.h"
+#ifndef QT_NO_QOBJECT
+
 #include "QtCore/qobject.h"
 #include "QtCore/qstringlist.h"
 #include "QtCore/qjsonobject.h"
 #include "QtCore/qmap.h"
 #include "private/qlibrary_p.h"
-#ifndef QT_NO_LIBRARY
 
 QT_BEGIN_NAMESPACE
 
 class QFactoryLoaderPrivate;
-
 class Q_CORE_EXPORT QFactoryLoader : public QObject
 {
     Q_OBJECT
@@ -65,21 +66,23 @@ public:
     explicit QFactoryLoader(const char *iid,
                    const QString &suffix = QString(),
                    Qt::CaseSensitivity = Qt::CaseSensitive);
+
+#ifndef QT_NO_LIBRARY
     ~QFactoryLoader();
 
-    QList<QJsonObject> metaData() const;
-    QObject *instance(int index) const;
+    void update();
+    static void refreshAll();
 
 #if defined(Q_OS_UNIX) && !defined (Q_OS_MAC)
     QLibraryPrivate *library(const QString &key) const;
-#endif
+#endif // Q_OS_UNIX && !Q_OS_MAC
+#endif // !QT_NO_LIBRARY
 
     QMultiMap<int, QString> keyMap() const;
     int indexOf(const QString &needle) const;
 
-    void update();
-
-    static void refreshAll();
+    QList<QJsonObject> metaData() const;
+    QObject *instance(int index) const;
 };
 
 template <class PluginInterface, class FactoryInterface>
@@ -112,6 +115,6 @@ PluginInterface *qLoadPlugin1(const QFactoryLoader *loader,
 
 QT_END_NAMESPACE
 
-#endif // QT_NO_LIBRARY
+#endif // QT_NO_QOBJECT
 
 #endif // QFACTORYLOADER_P_H
diff --git a/src/corelib/plugin/qlibrary.cpp b/src/corelib/plugin/qlibrary.cpp
index 920e02ae5a..763f0fb1e9 100644
--- a/src/corelib/plugin/qlibrary.cpp
+++ b/src/corelib/plugin/qlibrary.cpp
@@ -302,7 +302,7 @@ static bool findPatternUnloaded(const QString &library, QLibraryPrivate *lib)
     if (pos >= 0) {
         if (hasMetaData) {
             const char *data = filedata + pos;
-            QJsonDocument doc = QLibraryPrivate::fromRawMetaData(data);
+            QJsonDocument doc = qJsonFromRawLibraryMetaData(data);
             lib->metaData = doc.object();
             if (qt_debug_component())
                 qWarning("Found metadata in lib %s, metadata=\n%s\n",
@@ -677,7 +677,7 @@ static bool qt_get_metadata(QtPluginQueryVerificationDataFunction pfn, QLibraryP
     if (!szData)
         return false;
 
-    QJsonDocument doc = QLibraryPrivate::fromRawMetaData(szData);
+    QJsonDocument doc = qJsonFromRawLibraryMetaData(szData);
     if (doc.isNull())
         return false;
     priv->metaData = doc.object();
diff --git a/src/corelib/plugin/qlibrary_p.h b/src/corelib/plugin/qlibrary_p.h
index ada90d7bfd..11b0cb1eb9 100644
--- a/src/corelib/plugin/qlibrary_p.h
+++ b/src/corelib/plugin/qlibrary_p.h
@@ -57,9 +57,20 @@
 #  include "QtCore/qt_windows.h"
 #endif
 
+QT_BEGIN_NAMESPACE
+
+// Needed also in case of QT_NO_LIBRARY, for static plugin loading.
+inline QJsonDocument qJsonFromRawLibraryMetaData(const char *raw)
+{
+    raw += strlen("QTMETADATA  ");
+    // the size of the embedded JSON object can be found 8 bytes into the data (see qjson_p.h),
+    // but doesn't include the size of the header (8 bytes)
+    QByteArray json(raw, qFromLittleEndian<uint>(*(const uint *)(raw + 8)) + 8);
+    return QJsonDocument::fromBinaryData(json);
+}
+
 #ifndef QT_NO_LIBRARY
 
-QT_BEGIN_NAMESPACE
 
 bool qt_debug_component();
 
@@ -104,14 +115,6 @@ public:
     void updatePluginState();
     bool isPlugin();
 
-    static inline QJsonDocument fromRawMetaData(const char *raw) {
-        raw += strlen("QTMETADATA  ");
-        // the size of the embedded JSON object can be found 8 bytes into the data (see qjson_p.h),
-        // but doesn't include the size of the header (8 bytes)
-        QByteArray json(raw, qFromLittleEndian<uint>(*(const uint *)(raw + 8)) + 8);
-        return QJsonDocument::fromBinaryData(json);
-    }
-
 private:
     explicit QLibraryPrivate(const QString &canonicalFileName, const QString &version, QLibrary::LoadHints loadHints);
     ~QLibraryPrivate();
@@ -132,8 +135,8 @@ private:
     friend class QLibraryStore;
 };
 
-QT_END_NAMESPACE
-
 #endif // QT_NO_LIBRARY
 
+QT_END_NAMESPACE
+
 #endif // QLIBRARY_P_H
diff --git a/src/corelib/plugin/qpluginloader.cpp b/src/corelib/plugin/qpluginloader.cpp
index 292ad30525..b95f7539f6 100644
--- a/src/corelib/plugin/qpluginloader.cpp
+++ b/src/corelib/plugin/qpluginloader.cpp
@@ -41,10 +41,10 @@
 #include "qdebug.h"
 #include "qdir.h"
 
-#ifndef QT_NO_LIBRARY
-
 QT_BEGIN_NAMESPACE
 
+#ifndef QT_NO_LIBRARY
+
 /*!
     \class QPluginLoader
     \inmodule QtCore
@@ -382,9 +382,6 @@ QString QPluginLoader::errorString() const
     return (!d || d->errorString.isEmpty()) ? tr("Unknown error") : d->errorString;
 }
 
-typedef QVector<QStaticPlugin> StaticPluginList;
-Q_GLOBAL_STATIC(StaticPluginList, staticPluginList)
-
 /*! \since 4.4
 
     \property QPluginLoader::loadHints
@@ -413,6 +410,11 @@ QLibrary::LoadHints QPluginLoader::loadHints() const
     return d ? d->loadHints() : QLibrary::LoadHints();
 }
 
+#endif // QT_NO_LIBRARY
+
+typedef QVector<QStaticPlugin> StaticPluginList;
+Q_GLOBAL_STATIC(StaticPluginList, staticPluginList)
+
 /*!
     \relates QPluginLoader
     \since 5.0
@@ -465,9 +467,8 @@ QVector<QStaticPlugin> QPluginLoader::staticPlugins()
 */
 QJsonObject QStaticPlugin::metaData() const
 {
-    return QLibraryPrivate::fromRawMetaData(rawMetaData()).object();
+    return qJsonFromRawLibraryMetaData(rawMetaData()).object();
 }
 
 QT_END_NAMESPACE
 
-#endif // QT_NO_LIBRARY
diff --git a/src/corelib/plugin/qpluginloader.h b/src/corelib/plugin/qpluginloader.h
index 0ab25bbb07..5dc7d1b66c 100644
--- a/src/corelib/plugin/qpluginloader.h
+++ b/src/corelib/plugin/qpluginloader.h
@@ -37,10 +37,10 @@
 #include <QtCore/qlibrary.h>
 #include <QtCore/qplugin.h>
 
-#ifndef QT_NO_LIBRARY
-
 QT_BEGIN_NAMESPACE
 
+#ifndef QT_NO_LIBRARY
+
 class QLibraryPrivate;
 class QJsonObject;
 
@@ -78,8 +78,17 @@ private:
     Q_DISABLE_COPY(QPluginLoader)
 };
 
-QT_END_NAMESPACE
+#else
+
+class Q_CORE_EXPORT QPluginLoader
+{
+public:
+    static QObjectList staticInstances();
+    static QVector<QStaticPlugin> staticPlugins();
+};
 
 #endif // QT_NO_LIBRARY
 
+QT_END_NAMESPACE
+
 #endif //QPLUGINLOADER_H
diff --git a/src/gui/kernel/qgenericplugin.cpp b/src/gui/kernel/qgenericplugin.cpp
index 47f3ea5811..ae423b93e3 100644
--- a/src/gui/kernel/qgenericplugin.cpp
+++ b/src/gui/kernel/qgenericplugin.cpp
@@ -33,8 +33,6 @@
 
 #include "qgenericplugin.h"
 
-#ifndef QT_NO_LIBRARY
-
 QT_BEGIN_NAMESPACE
 
 /*!
@@ -90,5 +88,3 @@ QGenericPlugin::~QGenericPlugin()
 */
 
 QT_END_NAMESPACE
-
-#endif // QT_NO_LIBRARY
diff --git a/src/gui/kernel/qgenericplugin.h b/src/gui/kernel/qgenericplugin.h
index 03c1df7fba..21ae97f045 100644
--- a/src/gui/kernel/qgenericplugin.h
+++ b/src/gui/kernel/qgenericplugin.h
@@ -39,9 +39,6 @@
 
 QT_BEGIN_NAMESPACE
 
-
-#ifndef QT_NO_LIBRARY
-
 #define QGenericPluginFactoryInterface_iid "org.qt-project.Qt.QGenericPluginFactoryInterface"
 
 class Q_GUI_EXPORT QGenericPlugin : public QObject
@@ -54,8 +51,6 @@ public:
     virtual QObject* create(const QString& name, const QString &spec) = 0;
 };
 
-#endif // QT_NO_LIBRARY
-
 QT_END_NAMESPACE
 
 #endif // QGENERICPLUGIN_H
diff --git a/tests/auto/corelib/plugin/qfactoryloader/test/test.pro b/tests/auto/corelib/plugin/qfactoryloader/test/test.pro
index d8dfaac29e..5e7f44c005 100644
--- a/tests/auto/corelib/plugin/qfactoryloader/test/test.pro
+++ b/tests/auto/corelib/plugin/qfactoryloader/test/test.pro
@@ -20,3 +20,8 @@ win32 {
 
 mac: CONFIG -= app_bundle
 DEFINES += QT_DISABLE_DEPRECATED_BEFORE=0
+
+load(qfeatures)
+contains(QT_DISABLED_FEATURES, library) {
+    LIBS += -L ../bin/ -lplugin1 -lplugin2
+}
diff --git a/tests/auto/corelib/plugin/qfactoryloader/tst_qfactoryloader.cpp b/tests/auto/corelib/plugin/qfactoryloader/tst_qfactoryloader.cpp
index 474f4e9868..92a4dda252 100644
--- a/tests/auto/corelib/plugin/qfactoryloader/tst_qfactoryloader.cpp
+++ b/tests/auto/corelib/plugin/qfactoryloader/tst_qfactoryloader.cpp
@@ -38,6 +38,11 @@
 #include "plugin1/plugininterface1.h"
 #include "plugin2/plugininterface2.h"
 
+#ifdef QT_NO_LIBRARY
+Q_IMPORT_PLUGIN(Plugin1)
+Q_IMPORT_PLUGIN(Plugin2)
+#endif
+
 class tst_QFactoryLoader : public QObject
 {
     Q_OBJECT
@@ -54,8 +59,9 @@ void tst_QFactoryLoader::initTestCase()
 {
     const QString binFolder = QFINDTESTDATA(binFolderC);
     QVERIFY2(!binFolder.isEmpty(), "Unable to locate 'bin' folder");
-
+#ifndef QT_NO_LIBRARY
     QCoreApplication::setLibraryPaths(QStringList(QFileInfo(binFolder).absolutePath()));
+#endif
 }
 
 void tst_QFactoryLoader::usingTwoFactoriesFromSameDir()