Android: Fix loading of plugins

In 5bb178c479, the Android platform plugin was moved from
platforms/android to platforms/. The unforeseen consequence of this was that the plugin
loader for plugins/platforms would now find it, whereas before it would be ignored. It
would therefore be detected as the appropriate plugin, but since it was intended to be
loaded as a static plugin, loading it dynamically would fail.

Instead of fixing the static plugin loading, we remove this hack.

Fixes: QTBUG-78440
Change-Id: Idcb6c075fdebaf67644f32a59d7aaf0d1c0bbe20
Reviewed-by: Eskil Abrahamsen Blomfeldt <eskil.abrahamsen-blomfeldt@qt.io>

src/corelib/kernel/qcoreapplication.cpp

@@ -2708,7 +2708,7 @@ QStringList QCoreApplication::libraryPathsLocked()
         QStringList *app_libpaths = new QStringList;
         coreappdata()->app_libpaths.reset(app_libpaths);
 
-        QString libPathEnv = qEnvironmentVariable("QT_PLUGIN_PATH");
+        auto setPathsFromEnv = [&](QString libPathEnv) {
             if (!libPathEnv.isEmpty()) {
                 QStringList paths = libPathEnv.split(QDir::listSeparator(), QString::SkipEmptyParts);
                 for (QStringList::const_iterator it = paths.constBegin(); it != paths.constEnd(); ++it) {
@@ -2719,7 +2719,11 @@ QStringList QCoreApplication::libraryPathsLocked()
                     }
                 }
             }
-
+        };
+        setPathsFromEnv(qEnvironmentVariable("QT_PLUGIN_PATH"));
+#ifdef Q_OS_ANDROID
+        setPathsFromEnv(qEnvironmentVariable("QT_BUNDLED_LIBS_PATH"));
+#endif
 #ifdef Q_OS_DARWIN
         // Check the main bundle's PlugIns directory as this is a standard location for Apple OSes.
         // Note that the QLibraryInfo::PluginsPath below will coincidentally be the same as this value

src/corelib/plugin/qfactoryloader.cpp

@@ -193,7 +193,11 @@ void QFactoryLoader::update()
             continue;
         d->loadedPaths << pluginDir;
 
+#ifdef Q_OS_ANDROID
+        QString path = pluginDir;
+#else
         QString path = pluginDir + d->suffix;
+#endif
 
         if (qt_debug_component())
             qDebug() << "QFactoryLoader::QFactoryLoader() checking directory path" << path << "...";
@@ -202,8 +206,10 @@ void QFactoryLoader::update()
             continue;
 
         QStringList plugins = QDir(path).entryList(
-#ifdef Q_OS_WIN
+#if defined(Q_OS_WIN)
                     QStringList(QStringLiteral("*.dll")),
+#elif defined(Q_OS_ANDROID)
+                    QStringList(QLatin1String("plugins_%1_*.so").arg(d->suffix)),
 #endif
                     QDir::Files);
         QLibraryPrivate *library = 0;
@@ -339,6 +345,10 @@ QFactoryLoader::QFactoryLoader(const char *iid,
 #if QT_CONFIG(library)
     d->cs = cs;
     d->suffix = suffix;
+# ifdef Q_OS_ANDROID
+    if (!d->suffix.isEmpty() && d->suffix.at(0) == QLatin1Char('/'))
+        d->suffix.remove(0, 1);
+# endif
 
     QMutexLocker locker(qt_factoryloader_mutex());
     update();

src/corelib/plugin/qlibrary_unix.cpp

@@ -236,6 +236,14 @@ bool QLibraryPrivate::load_sys()
                 auto attemptFromBundle = attempt;
                 pHnd = dlopen(QFile::encodeName(attemptFromBundle.replace(QLatin1Char('/'), QLatin1Char('_'))), dlFlags);
             }
+            if (pHnd) {
+                using JniOnLoadPtr = jint (*)(JavaVM *vm, void *reserved);
+                JniOnLoadPtr jniOnLoad = reinterpret_cast<JniOnLoadPtr>(dlsym(pHnd, "JNI_OnLoad"));
+                if (jniOnLoad && jniOnLoad(QtAndroidPrivate::javaVM(), nullptr) == JNI_ERR) {
+                    dlclose(pHnd);
+                    pHnd = nullptr;
+                }
+            }
 #endif
 
             if (!pHnd && fileName.startsWith(QLatin1Char('/')) && QFile::exists(attempt)) {

src/corelib/plugin/qpluginloader.cpp

@@ -311,6 +311,16 @@ static QString locatePlugin(const QString& fileName)
     for (const QString &path : qAsConst(paths)) {
         for (const QString &prefix : qAsConst(prefixes)) {
             for (const QString &suffix : qAsConst(suffixes)) {
+#ifdef Q_OS_ANDROID
+                {
+                    QString pluginPath = basePath + prefix + baseName + suffix;
+                    const QString fn = path + QLatin1String("/lib") + pluginPath.replace(QLatin1Char('/'), QLatin1Char('_'));
+                    if (debug)
+                        qDebug() << "Trying..." << fn;
+                    if (QFileInfo(fn).isFile())
+                        return fn;
+                }
+#endif
                 const QString fn = path + QLatin1Char('/') + basePath + prefix + baseName + suffix;
                 if (debug)
                     qDebug() << "Trying..." << fn;

src/plugins/platforms/android/android.pro

@@ -1,9 +1,5 @@
 TARGET = qtforandroid
 
-# STATICPLUGIN needed because there's a Q_IMPORT_PLUGIN in androidjnimain.cpp
-# Yes, the plugin imports itself statically
-DEFINES += QT_STATICPLUGIN
-
 LIBS += -ljnigraphics -landroid
 
 QT += \
@@ -19,7 +15,8 @@ INCLUDEPATH += \
     $$PWD \
     $$QT_SOURCE_TREE/src/3rdparty/android
 
-SOURCES += $$PWD/androidplatformplugin.cpp \
+SOURCES += $$PWD/main.cpp \
+           $$PWD/androidplatformplugin.cpp \
            $$PWD/androidcontentfileengine.cpp \
            $$PWD/androiddeadlockprotector.cpp \
            $$PWD/androidjnimain.cpp \
@@ -92,4 +89,5 @@ qtConfig(vulkan) {
 }
 
 PLUGIN_TYPE = platforms
+PLUGIN_CLASS_NAME = QAndroidIntegrationPlugin
 load(qt_plugin)

src/plugins/platforms/android/androidjnimain.cpp

@@ -68,8 +68,6 @@
 
 #include <qpa/qwindowsysteminterface.h>
 
-Q_IMPORT_PLUGIN(QAndroidPlatformIntegrationPlugin)
-
 QT_BEGIN_NAMESPACE
 
 static JavaVM *m_javaVM = nullptr;

src/plugins/platforms/android/main.cpp

@@ -0,0 +1,63 @@
+/****************************************************************************
+**
+** Copyright (C) 2019 BogDan Vatra <bogdan@kde.org>
+** Contact: https://www.qt.io/licensing/
+**
+** This file is part of the plugins of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** Commercial License Usage
+** Licensees holding valid commercial Qt licenses may use this file in
+** accordance with the commercial license agreement provided with the
+** Software or, alternatively, in accordance with the terms contained in
+** a written agreement between you and The Qt Company. For licensing terms
+** and conditions see https://www.qt.io/terms-conditions. For further
+** information use the contact form at https://www.qt.io/contact-us.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 3 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL3 included in the
+** packaging of this file. Please review the following information to
+** ensure the GNU Lesser General Public License version 3 requirements
+** will be met: https://www.gnu.org/licenses/lgpl-3.0.html.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 2.0 or (at your option) the GNU General
+** Public license version 3 or any later version approved by the KDE Free
+** Qt Foundation. The licenses are as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL2 and LICENSE.GPL3
+** included in the packaging of this file. Please review the following
+** information to ensure the GNU General Public License requirements will
+** be met: https://www.gnu.org/licenses/gpl-2.0.html and
+** https://www.gnu.org/licenses/gpl-3.0.html.
+**
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+
+#include <qpa/qplatformintegrationplugin.h>
+#include "qandroidplatformintegration.h"
+
+QT_BEGIN_NAMESPACE
+
+class QAndroidIntegrationPlugin : public QPlatformIntegrationPlugin
+{
+    Q_OBJECT
+    Q_PLUGIN_METADATA(IID QPlatformIntegrationFactoryInterface_iid FILE "android.json")
+
+public:
+    QPlatformIntegration *create(const QString& system, const QStringList& paramList) override;
+};
+
+QPlatformIntegration *QAndroidIntegrationPlugin::create(const QString& system, const QStringList& paramList)
+{
+    if (!system.compare(QLatin1String("android"), Qt::CaseInsensitive))
+        return new QAndroidPlatformIntegration(paramList);
+
+    return nullptr;
+}
+
+QT_END_NAMESPACE