obsolete vs. removed from the library

[amn@hutcs.UUCP.UUCP]

According to LRM 10.1:6  a subprogram body is treated as a secondary
unit if the program library already contains a library unit (= a sub-
program declaration) that is a subprogram with the same name.
This means that to recompile a library subprogram the declaration
or context clauses of which have been changed one has to compile
a genuine subprogram specification without the corresponding body
as a separate compilation unit.

LRM 10.3:5 states that obsolete compilation units must be recompiled
unless they are no longer needed.  I think this means you cannot
recompile a subprogram body if its specification is obsolete, as
the recompilation needs the specification.

I am not sure whether there is any need for having obsolete
compilation units in the library.  I think that 10.3:5 means that
obsolete compilation units cannot be utilized.  The only reason
to have obsolete compilation units in a program library could be
that the compilation library tools can decide which compilation
units need to be recompiled after an 'obsoleting' compilation.

Ari Mujunen
Helsinki University of Technology
(mcvax!penet!hut!amn, I suppose)