The Enabled attribute allows an application program to check at compile
time to see if the designated check is currently enabled. The prefix is a
simple identifier, referencing any predefined check name (other than
All_Checks) or a check name introduced by pragma Check_Name. If
no argument is given for the attribute, the check is for the general state
of the check, if an argument is given, then it is an entity name, and the
check indicates whether an Suppress or Unsuppress has been
given naming the entity (if not, then the argument is ignored).
Note that instantiations inherit the check status at the point of the
instantiation, so a useful idiom is to have a library package that
introduces a check name with pragma Check_Name, and then contains
generic packages or subprograms which use the Enabled attribute
to see if the check is enabled. A user of this package can then issue
a pragma Suppress or pragma Unsuppress before instantiating
the package or subprogram, controlling whether the check will be present.