Re: [PATCH] Add cast to unsigned char to strverscmp

[email protected]
Newsgroups gmane.comp.lib.newlib
Organization Systematic Software
Message-ID <[email protected]>
On 2024-11-07 09:53, Jeremy Bettis wrote:
> GCC 14.2 with -Werror=sign-compare fails on this code.
> 
> Signed-off-by: Jeremy Bettis <[email protected] <mailto:[email protected]>>
> ---
>   newlib/libc/string/strverscmp.c | 2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> diff --git a/newlib/libc/string/strverscmp.c b/newlib/libc/string/strverscmp.c
> index 55966335f..e86718faa 100644
> --- a/newlib/libc/string/strverscmp.c
> +++ b/newlib/libc/string/strverscmp.c
> @@ -76,7 +76,7 @@ int strverscmp(const char *l0, const char *r0)
>    else if (c!='0') z=0;
>    }
> 
> - if (l[dp]<'1' + 9U && r[dp]<'1' + 9U) {

I'd call that a false positive?

> + if ((unsigned char)(l[dp]-'1')<9U && (unsigned char)(r[dp]-'1')<9U) {

What happens when chars are '\0' or '\x80'?

>    /* If we're looking at non-degenerate digit sequences starting
>    * with nonzero digits, longest digit string is greater. */
>    for (j=i; isdigit(l[j]); j++)

-- 
Take care. Thanks, Brian Inglis              Calgary, Alberta, Canada

La perfection est atteinte                   Perfection is achieved
non pas lorsqu'il n'y a plus rien à ajouter  not when there is no more to add
mais lorsqu'il n'y a plus rien à retirer     but when there is no more to cut
                                 -- Antoine de Saint-Exupéry
lmpx.com only provides a reader for public news (NNTP) servers. It is not affiliated with the servers or forums shown here and is not responsible for the content of articles, which is written by their respective authors.