Re: continuing continue - was Re: [patch] continue statement
[
Date Prev][
Date Next][
Thread Prev][
Thread Next]
[
Date Index]
[
Thread Index]
- Subject: Re: continuing continue - was Re: [patch] continue statement
- From: Glenn Maynard <glenn@...>
- Date: 2005年9月25日 04:43:43 -0400
On Sun, Sep 25, 2005 at 10:14:05AM +0200, Philippe Lhoste wrote:
> destroy(c);
> errorC:
>
> destroy(b);
> errorB:
>
> destroy(a);
> errorA:
This type of cleanup gives me headaches. I might occasionally point out
that "goto isn't *always* evil", but this is a textbook example of when
it is. :)
A label and a distinct goto for every error check; they have to be in a very
specific order; getting the order wrong will lead to breakage or memory leaks
(and possibly in the worst possible place: an error path, which can make
them obscure); it doesn't handle very well the case where the objects are
created in a less trivial order (eg. put the "b" and "c" cases inside opposite
conditionals) ...
> When possible, I avoid mixing true boolean with NULL/0 values, which you
> do in your cleanup code.
I try to, but it's valid and straightforward, so I often don't bother
(especially in example code typed into mail :).
> My code avoids tests, which is interesting only in time critical
> applications, I suppose.
Error cleanup paths are very rarely time-critical, though. I just don't
think that this style has any advantages (at least for the cleanup cases
we've looked at so far).
> IMHO, both codes are OK, your may be better suited to complex destroy cases.
My code is more straightforward for simple cases, too, IMO.
--
Glenn Maynard