Path: utzoo!attcan!utgpu!news-server.csri.toronto.edu!mailrus!cs.utexas.edu!sun-barr!rutgers!att!cbnewsh!warren
From: warren@cbnewsh.att.com (warren.a.montgomery)
Newsgroups: comp.lang.c++
Subject: Re: AT&T 2.1 and stdargs
Summary: Turn off optimization when using stdargs on a Sparc machine
Message-ID: <1990Sep23.162833.2936@cbnewsh.att.com>
Date: 23 Sep 90 16:28:33 GMT
References: <1990Sep19.062219.29519@cs.nott.ac.uk>
Organization: AT&T Bell Laboratories
Lines: 19

My work group spent quite a bit of time tracking down problems
with the use of stdargs on a Sparc based machine.  We concluded
that you cannot compile code that uses stdargs with the optimizer
on a Sparc based Sun.  The trouble appears to be that the optizer
uses the name of the arguments to a function to deterine whether
or not the function may take varying arguments, and if so whether
it needs to be compiled so as to preserve the argument stack for
use by the varargs or stdargs library.  The C++ name mangling
procedure does not always produce the right "magic" parameter name
to trigger the generation of the varying arguments code, and
the call will fail if it isn't generated correctly.  I believe
that the optimization only has to be disabled on the compilation
of the varying arguments function itself, not the things that call
it.

-- 

	Warren Montgomery
	att!ihlpf!warren