Internal Accessibility

The C# language specification is very vague when it describes internal visibility. We map "the program" to the assembly being compiled; internal accessibility is not extended to assemblies that import the compilation unless specifically granted that access by the use of InternalsVisibleToAttribute.

There are many places where this affects the semantics of the language without supporting language from the C# language specification. For example, if there is a type name in the current assembly that conflicts with the same name from another assembly, we allow the reference to the name and treat it as a reference to the name from the current assembly. Furthermore, the rule that a using alias may not conflict with a type of the same name is not enforced if the conflicting type comes from another assembly.