Path: utzoo!mnetor!uunet!mcvax!inria!blueberry!shapiro
From: shapiro@blueberry.inria.fr (Marc Shapiro)
Newsgroups: comp.lang.c++
Subject: Re: Exception handling
Message-ID: <627@inria.UUCP>
Date: 4 Mar 88 08:33:50 GMT
References: <3117@okstate.UUCP> <306@nih-csl.UUCP>
Sender: news@inria.UUCP
Organization: Institut National de Recherche en Informatique et Automatique, Rocquencourt, France
Lines: 27
Summary: you can do exception handling in C++

In article <306@nih-csl.UUCP> keith@nih-csl.UUCP (keith gorlen) writes:
>But don't get excited -- the real problem is that when an exception
>occurs and you want to jump out to an enclosing exception frame,
>there's no way to get the destructors of all the objects local to
>blocks that are going out of scope called without help from the
>compiler.

Well, it can be fudged.  We have a macro package for exceptions
(thanks to Dima Abrossimov) which does the right thing.  This is how
it works: macro-expand a "raise exception" into "fudge the stack;
return".  Cfront sees the return and generates calls to destructors of
local variables; however you have fudged the stack so that the return
jumps into your exception handler instead of continuing in sequence.

I'm not saying it's the right way.  Proper compiler support is a much
better idea.


						Marc Shapiro

INRIA, B.P. 105, 78153 Le Chesnay Cedex, France.  Tel.: +33 (1) 39-63-53-25
e-mail: shapiro@inria.inria.fr or: ...!mcvax!inria!shapiro

						Marc Shapiro

INRIA, B.P. 105, 78153 Le Chesnay Cedex, France.  Tel.: +33 (1) 39-63-53-25
e-mail: shapiro@inria.inria.fr or: ...!mcvax!inria!shapiro