Expose "indexed" attribute on event parameters (used to indicate incl…

…usion in bloom filter).

slither/core/variables/event_variable.py

@@ -1,5 +1,16 @@
 from .variable import Variable
 from slither.core.children.child_event import ChildEvent
 
-class EventVariable(ChildEvent, Variable): pass
+class EventVariable(ChildEvent, Variable):
+    def __init__(self):
+        super(EventVariable, self).__init__()
+        self._indexed = False
+
+    @property
+    def indexed(self):
+        """
+        Indicates whether the event variable is indexed in the bloom filter.
+        :return: Returns True if the variable is indexed in bloom filter, False otherwise.
+        """
+        return self._indexed
 

slither/solc_parsing/variables/event_variable.py

@@ -2,4 +2,18 @@
 from .variable_declaration import VariableDeclarationSolc
 from slither.core.variables.event_variable import EventVariable
 
-class EventVariableSolc(VariableDeclarationSolc, EventVariable): pass
+class EventVariableSolc(VariableDeclarationSolc, EventVariable):
+
+    def _analyze_variable_attributes(self, attributes):
+        """
+        Analyze event variable attributes
+        :param attributes: The event variable attributes to parse.
+        :return: None
+        """
+
+        # Check for the indexed attribute
+        if 'indexed' in attributes:
+            self._indexed = attributes['indexed']
+
+        super(EventVariableSolc, self)._analyze_variable_attributes(attributes)
+