From: Jeffrey Walton <noloader@gmail.com>
To: "Marc Nieper-Wißkirchen" <marc.nieper+gnu@gmail.com>
Cc: "bug-gnulib@gnu.org List" <bug-gnulib@gnu.org>
Subject: Re: New function xpalloc in module xalloc
Date: Sun, 4 Apr 2021 02:23:57 -0400 [thread overview]
Message-ID: <CAH8yC8mest8Po9NdmQ3qv3Q391_Hj03uTrNHK4McDGkSZ6rtxw@mail.gmail.com> (raw)
In-Reply-To: <CAEYrNrTWcLXUWw_Fno_-S3cfs-iDoA-5Kd0TfCHqpSB8tbw6Ow@mail.gmail.com>
On Sun, Apr 4, 2021 at 2:17 AM Marc Nieper-Wißkirchen
<marc.nieper+gnu@gmail.com> wrote:
>
> GCC prints the following warning when compiling the new code:
>
> lib/xmalloc.c: In function 'xpalloc':
> lib/xmalloc.c:132:64: warning: comparison of integer expressions of different signedness: 'long unsigned int' and 'idx_t' {aka 'long int'} [-Wsign-compare]
> 132 | = ((INT_MULTIPLY_WRAPV (n, item_size, &nbytes) || SIZE_MAX < nbytes)
>
> If I understand the error message correctly, it is because 'nbytes' is a signed type while SIZE_MAX is unsigned.
>
> Does the comparison make any sense, by the way?
Only for positive integers.
If idx_t is negative, like -1, then -1 will be promoted to an unsigned
type and then -1 > 0.
Jeff
next prev parent reply other threads:[~2021-04-04 6:24 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-04-04 6:17 New function xpalloc in module xalloc Marc Nieper-Wißkirchen
2021-04-04 6:23 ` Jeffrey Walton [this message]
2021-04-04 6:43 ` Marc Nieper-Wißkirchen
2021-04-06 3:19 ` Paul Eggert
2021-04-06 6:48 ` Marc Nieper-Wißkirchen
2021-04-06 19:05 ` Paul Eggert
2021-04-06 19:23 ` Marc Nieper-Wißkirchen
2021-04-06 20:07 ` Paul Eggert
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