implement basic plugin loader for laser

mythril/laser/ethereum/plugins/plugin_loader.py

@@ -0,0 +1,31 @@
+from mythril.laser.ethereum.svm import LaserEVM
+from mythril.laser.ethereum.plugins.plugin import LaserPlugin
+
+
+class LaserPluginLoader:
+    """
+    The LaserPluginLoader is used to abstract the logic relating to plugins.
+    Components outside of laser thus don't have to be aware of the interface that plugins provide
+    """
+    def __init__(self, symbolic_vm: LaserEVM):
+        """ Initializes the plugin loader
+
+        :param symbolic_vm: symbolic virtual machine to load plugins for
+        """
+        self.symbolic_vm = symbolic_vm
+        self.laser_plugins = []
+
+    def load(self, laser_plugin: LaserPlugin):
+        """ Loads the plugin
+
+        :param laser_plugin: plugin that will be loaded in the symbolic virtual machine
+        """
+        laser_plugin.initialize(self.symbolic_vm)
+        self.laser_plugins.append(laser_plugin)
+
+    def is_enabled(self, laser_plugin: LaserPlugin):
+        """ Returns whether the plugin is loaded in the symbolic_vm
+
+        :param laser_plugin: plugin that will be checked
+        """
+        return laser_plugin in self.laser_plugins