Initial commit

backends/plugins/dynamic-plugin.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+#ifndef BACKENDS_PLUGINS_DYNAMICPLUGIN_H
+#define BACKENDS_PLUGINS_DYNAMICPLUGIN_H
+
+#include "base/plugins.h"
+#include "common/textconsole.h"
+
+
+class DynamicPlugin : public Plugin {
+protected:
+	typedef int32 (*IntFunc)();
+	typedef void (*VoidFunc)();
+	typedef PluginObject *(*GetObjectFunc)();
+
+	virtual VoidFunc findSymbol(const char *symbol) = 0;
+
+	const Common::Path _filename;
+
+public:
+	DynamicPlugin(const Common::Path &filename) :
+		_filename(filename) {}
+
+	bool loadPlugin() override {
+		// Validate the plugin API version
+		IntFunc verFunc = (IntFunc)findSymbol("PLUGIN_getVersion");
+		if (!verFunc) {
+			unloadPlugin();
+			return false;
+		}
+		if (verFunc() != PLUGIN_VERSION) {
+			warning("Plugin uses a different API version (you have: '%d', needed is: '%d')", verFunc(), PLUGIN_VERSION);
+			unloadPlugin();
+			return false;
+		}
+
+		// Get the type of the plugin
+		IntFunc typeFunc = (IntFunc)findSymbol("PLUGIN_getType");
+		if (!typeFunc) {
+			unloadPlugin();
+			return false;
+		}
+		_type = (PluginType)typeFunc();
+		if (_type >= PLUGIN_TYPE_MAX) {
+			warning("Plugin type unknown: %d", _type);
+			unloadPlugin();
+			return false;
+		}
+
+		// Validate the plugin type API version
+		IntFunc typeVerFunc = (IntFunc)findSymbol("PLUGIN_getTypeVersion");
+		if (!typeVerFunc) {
+			unloadPlugin();
+			return false;
+		}
+		if (typeVerFunc() != pluginTypeVersions[_type]) {
+			warning("Plugin uses a different type API version (you have: '%d', needed is: '%d')", typeVerFunc(), pluginTypeVersions[_type]);
+			unloadPlugin();
+			return false;
+		}
+
+		// Get the plugin's instantiator object
+		GetObjectFunc getObject = (GetObjectFunc)findSymbol("PLUGIN_getObject");
+		if (!getObject) {
+			unloadPlugin();
+			return false;
+		}
+
+		// Get the plugin object
+		_pluginObject = getObject();
+		if (!_pluginObject) {
+			warning("Couldn't get the plugin object");
+			unloadPlugin();
+			return false;
+		}
+
+		return true;
+	}
+
+	void unloadPlugin() override {
+		delete _pluginObject;
+		_pluginObject = nullptr;
+	}
+
+	Common::Path getFileName() const override {
+		return _filename;
+	}
+};
+
+#endif