Path: utzoo!attcan!uunet!husc6!bbn!inmet!ishmael!inmet!ada-uts!stt
From: stt@ada-uts
Newsgroups: comp.lang.ada
Subject: Re: Dynamic Address Clauses??
Message-ID: <57900075@ada-uts>
Date: 10 Jun 88 14:38:00 GMT
References: <5697@aw.sei.cmu.edu>
Lines: 26
Nf-ID: #R:aw.sei.cmu.edu:-569700:ada-uts:57900075:000:1068
Nf-From: ada-uts!stt    Jun 10 10:38:00 1988


I have always presumed address clauses were directives to
the compiler or the linker, but certainly not to the run-time system.

The interpretation of the specified address is implementation-dependent,
including whether it is accepted.  The fact that
simple_expression is allowed rather than simply a literal
is simply to allow some freedom to the implementation, but
in no way requires that dynamic address clauses be supported.

As a compiler implementor one certainly has the freedom to
define address clauses as one sees fit, but if this discussion
is aimed at gaining a consensus as to the "normal" or "standard"
interpretation of address clauses, I would expect them to be
limited to expressions which can be evaluated at or before link-time.

For example, one might allow the sum of the address of one
unit and an offset for the address of a second unit.

To me it seems kind of pointless to try and figure out a meaning
for an address expression which will probably never be accepted by
an Ada compiler.

S. Tucker Taft
Intermetrics, Inc.
Cambridge, MA  02138