From: Linus Torvalds <torvalds@linux-foundation.org>
To: Pavel Roskin <proski@gnu.org>
Cc: linux-sparse@vger.kernel.org
Subject: Re: Feature request - allow boolean operations of undefined cpp symbols
Date: Fri, 2 Feb 2007 10:25:12 -0800 (PST) [thread overview]
Message-ID: <Pine.LNX.4.64.0702021021570.15057@woody.linux-foundation.org> (raw)
In-Reply-To: <1170437836.2272.22.camel@dv>
On Fri, 2 Feb 2007, Pavel Roskin wrote:
>
> I think sparse should distinguish between safe and unsafe preprocessor
> operations on undefined symbols.
It does.
Try this:
#define NECESSARY 1
#if NECESSARY || UNNECESSARY
#endif
and notice how sparse does NOT warn about UNNECESSARY not being defined.
Because it doesn't matter.
> For instance, "#if SYMBOL" has a very specific meaning
No.
#if SYMBOL
has a very specific *problem* - it very possibly is a typo.
So this is a warning I absolutely *want* for the kernel. If some other
projects don't want it, fine, but it should be on by default as a warnign
for potentially dangerous use of preprocessor symbols.
Linus
next prev parent reply other threads:[~2007-02-02 18:25 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2007-02-02 17:37 Feature request - allow boolean operations of undefined cpp symbols Pavel Roskin
2007-02-02 18:25 ` Linus Torvalds [this message]
2007-02-02 21:56 ` Christopher Li
2007-02-02 22:30 ` Pavel Roskin
2007-02-02 22:10 ` Christopher Li
2007-02-02 22:58 ` Pavel Roskin
2007-02-02 22:45 ` Linus Torvalds
2007-04-20 10:02 ` Josh Triplett
2007-04-20 22:42 ` Pavel Roskin
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=Pine.LNX.4.64.0702021021570.15057@woody.linux-foundation.org \
--to=torvalds@linux-foundation.org \
--cc=linux-sparse@vger.kernel.org \
--cc=proski@gnu.org \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).