From: Jonathan Wakely <jwakely@redhat.com>
To: Joseph Myers <joseph@codesourcery.com>
Cc: libc-alpha@sourceware.org
Subject: Re: [PATCH] Suppress -Wcast-qual warnings in bsearch
Date: Wed, 19 May 2021 16:50:37 +0100 [thread overview]
Message-ID: <YKUzzZwNF3YajJaX@redhat.com> (raw)
In-Reply-To: <alpine.DEB.2.22.394.2105191535500.14970@digraph.polyomino.org.uk>
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On 19/05/21 15:37 +0000, Joseph Myers wrote:
>On Wed, 19 May 2021, Jonathan Wakely via Libc-alpha wrote:
>
>> +#pragma GCC diagnostic push
>> +#pragma GCC diagnostic ignored "-Wcast-qual"
>> return (void *) __p;
>> +#pragma GCC diagnostic pop
>
>I think such pragma uses in installed headers should be conditional on
>__GNUC_PREREQ (4, 6) (either directly or via conditionally defining a
>macro in sys/cdefs.h).
Good point.
I spent about two minutes trying to do something with _Pragma in
sys/cdefs.h to allow:
__GLIBC_IGNORE_WARNING("-Wcast-qual")
return (void *) __p;
__GLIBC_UNIGNORE_WARNING
but didn't get it working, so here's a patch that just tests
__GNUC_PREREQ directly.
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commit ee7c2451a102b4cd3c87a31b3156ad4458729840
Author: Jonathan Wakely <jwakely@redhat.com>
Date: Wed May 19 16:48:19 2021 +0100
Suppress -Wcast-qual warnings in bsearch
The first cast to (void *) is redundant but should be (const void *)
anyway, because that's the type of the lvalue being assigned to.
The second cast is necessary and intentionally not const-correct, so
tell the compiler not to warn about it.
diff --git a/bits/stdlib-bsearch.h b/bits/stdlib-bsearch.h
index 4132dc6af0..d688ed2e15 100644
--- a/bits/stdlib-bsearch.h
+++ b/bits/stdlib-bsearch.h
@@ -29,14 +29,21 @@ bsearch (const void *__key, const void *__base, size_t __nmemb, size_t __size,
while (__l < __u)
{
__idx = (__l + __u) / 2;
- __p = (void *) (((const char *) __base) + (__idx * __size));
+ __p = (const void *) (((const char *) __base) + (__idx * __size));
__comparison = (*__compar) (__key, __p);
if (__comparison < 0)
__u = __idx;
else if (__comparison > 0)
__l = __idx + 1;
else
+#if __GNUC_PREREQ(4, 6)
+# pragma GCC diagnostic push
+# pragma GCC diagnostic ignored "-Wcast-qual"
+#endif
return (void *) __p;
+#if __GNUC_PREREQ(4, 6)
+# pragma GCC diagnostic pop
+#endif
}
return NULL;
next prev parent reply other threads:[~2021-05-19 15:50 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-05-19 14:14 Jonathan Wakely
2021-05-19 15:37 ` Joseph Myers
2021-05-19 15:50 ` Jonathan Wakely [this message]
2021-06-01 10:09 ` [PATCH v3] " Jonathan Wakely
2021-09-30 9:22 ` [PATCH v2] " Jonathan Wakely
2021-09-30 10:43 ` Florian Weimer
2021-09-30 14:49 ` Adhemerval Zanella
2021-09-30 15:07 ` Joseph Myers
2021-09-30 15:19 ` Adhemerval Zanella
2021-09-30 15:30 ` Andreas Schwab
2021-09-30 16:41 ` Florian Weimer
2021-09-30 16:42 ` Joseph Myers
2021-09-30 16:52 ` Jonathan Wakely
2021-09-30 17:54 ` H.J. Lu
2021-09-30 18:04 ` Florian Weimer
2021-09-30 18:09 ` H.J. Lu
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