From: Eric Gallager <egall@gwmail.gwu.edu>
To: Jonathan Wakely <jwakely.gcc@gmail.com>
Cc: Andrea Monaco <andrea.monaco@autistici.org>,
"gcc@gcc.gnu.org" <gcc@gcc.gnu.org>
Subject: Re: No type checking in ctype builtins
Date: Thu, 28 Apr 2022 08:02:28 -0400 [thread overview]
Message-ID: <CAMfHzOv7v2V9Sax=rpGMQMcouaqXxhF+-BtNWdFdhNR=N=qo6A@mail.gmail.com> (raw)
In-Reply-To: <CAH6eHdRN8a09+ivse7JRPDSG73hRFUbWnofLpwTJ9+Gd+BzdMQ@mail.gmail.com>
On Wed, Apr 27, 2022 at 12:20 PM Jonathan Wakely via Gcc
<gcc@gcc.gnu.org> wrote:
>
> On Wed, 27 Apr 2022 at 16:29, Andrea Monaco via Gcc <gcc@gcc.gnu.org> wrote:
> >
> >
> > This program
> >
> > #include <ctype.h>
> >
> > int main ()
> > {
> > char *s;
> > isspace (s);
> > }
> >
> > compiles with no warning in gcc 8.3.0, even though there's a type
> > mistake; the correct call would be isspace (*s).
>
> N.B. The correct call would be isspace((unsigned char)*s) because
> isspace has undefined behaviour if you pass it a char with a negative
> value.
>
> It would be nice if GCC warned about *that*.
Related bugs:
78155: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=78155
99950: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=99950
prev parent reply other threads:[~2022-04-28 12:02 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-04-27 15:29 Andrea Monaco
2022-04-27 15:54 ` Andreas Schwab
2022-04-27 18:07 ` Andrea Monaco
2022-04-28 11:13 ` Florian Weimer
2022-04-27 16:19 ` Jonathan Wakely
2022-04-28 12:02 ` Eric Gallager [this message]
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='CAMfHzOv7v2V9Sax=rpGMQMcouaqXxhF+-BtNWdFdhNR=N=qo6A@mail.gmail.com' \
--to=egall@gwmail.gwu.edu \
--cc=andrea.monaco@autistici.org \
--cc=gcc@gcc.gnu.org \
--cc=jwakely.gcc@gmail.com \
/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 read-only IMAP folder(s) and NNTP newsgroup(s).