(declaim (ignore ignore))

[george@hsvaic.boeing.com (George Williams)]

This was posted a while back on the MCL mailing list, and I never saw
any responses.  Is there a reason that this doesn't work in ACL 4.1?

George Williams            BCS Huntsville Advanced Computing Group
Boeing Computer Services   Internet: george@hsvaic.boeing.com
POBox 240002, M/S JY-58    UUCP: ...!uw-beaver!bcsaic!hsvaic!george
Huntsville AL 35824-6402   Phone: 205+464-4968 FAX: 205+464-4930

--- Forwarded mail from hall@allegra.att.com (Bob Hall)

Date: Tue, 1 Dec 92 09:34:33 EST
From: hall@allegra.att.com (Bob Hall)
To: info-mcl@cambridge.apple.com
Subject: (declaim (ignore ignore))

The toplevel form
  (DECLAIM (IGNORE IGNORE))
works nicely in MCL to allow me to write, e.g.
  (DEFUN FOO (IGNORE) 4)
and avoid a compiler warning.  Also nicely, it issues a warning
if I DO use IGNORE when I declaimed it to be ignored.

What I'm having trouble with is whether this is defined in
"the" language (CLtL2? ANSI?) or is it an
extension?  It doesn't work in, for example, Allegro CL v4.1.
The DECLAIM above appears to have no effect, though it doesn't warn/error.
My recollection is that Symbolics CL just implicitly does the DECLAIM;
that is, if you name a local variable IGNORE, then the compiler
knows not to issue "unused" warnings.  (I don't remember if it warns
if you DO use such a var).

-- Bob

--- End of forwarded message from hall@allegra.att.com (Bob Hall)