3.10.2.4 Form of Definitions File

The definitions file contains lines of the form:

    symbol := value

where symbol is a preprocessing symbol, and value is one of the following:

• Empty, corresponding to a null substitution,
• A string literal using normal Ada syntax, or
• Any sequence of characters from the set {letters, digits, period, underline}.

Comment lines may also appear in the definitions file, starting with the usual --, and comments may be added to the definitions lines.