Interface for diagnostics from tools. A diagnostic usually reports a problem at a specific position in a source file. However, not all diagnostics are associated with a position or a file.
A position is a zero-based character offset from the beginning of
a file. Negative values (except NOPOS) are not valid
positions.
Line and column numbers begin at 1. Negative values (except
NOPOS) and 0 are not valid line or column numbers.
<S> | the type of source object used by this diagnostic |