A null checking Roslyn diagnostic analyzer for C#
This is a prototype used to explore the feasability of using a Roslyn code analyzer to perform checking for improper dereferencing of potentially null variables and improper assignment of potentially null values to variables that are not meant to be null.
It relies on the existence of custom attributes marking fields, parameters and return types to denote intent. Variables not declared with an attribute are not considered for null checking, unless through analysis they are shown to be in a known null or not-null state.
The specific attributes are CouldBeNullAttribute and ShouldNotBeNullAttribute. They are not defined by the analyzer,
but the analyzer will respond to any attributes with these names.