From: Alejandro Colomar <alx@kernel.org>
To: Andreas Schwab <schwab@linux-m68k.org>
Cc: libc-alpha@sourceware.org, "Arsen Arsenović" <arsen@gentoo.org>
Subject: Re: free(3) const void *
Date: Fri, 26 Jan 2024 16:33:49 +0100 [thread overview]
Message-ID: <ZbPQ3dONrhf8znMB@debian> (raw)
In-Reply-To: <87y1cc3z64.fsf@igel.home>
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Hi Andreas,
On Fri, Jan 26, 2024 at 04:13:55PM +0100, Andreas Schwab wrote:
> On Jan 26 2024, Alejandro Colomar wrote:
>
> > It is sometimes (often?) useful to allocate some object, write
> > immediately to it, and then use it read-only. The standard definition
> > of free() forces the programmer to keep a non-const pointer around just
> > for the sake of freeing, which is unnecessarily dangerous.
>
> It is even more dangerous to pretend that the contents are unmodified,
> when in fact they are no longer accessible (the memory can be reused any
> time in any way).
But that's why [[gnu::malloc(deallocator)]] exists, to helps determine
the lifetime of an object (although it's imperfect, since it doesn't
take into account reallocations).
Have a lovely day,
Alex
--
<https://www.alejandro-colomar.es/>
Looking for a remote C programming job at the moment.
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next prev parent reply other threads:[~2024-01-26 15:33 UTC|newest]
Thread overview: 33+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-01-26 13:21 Alejandro Colomar
2024-01-26 14:24 ` Arsen Arsenović
2024-01-26 15:35 ` Alejandro Colomar
2024-01-26 17:22 ` Arsen Arsenović
2024-01-26 17:55 ` Xi Ruoyao
2024-01-26 18:11 ` Alejandro Colomar
2024-01-26 20:04 ` Arsen Arsenović
2024-01-26 20:07 ` Arsen Arsenović
2024-01-26 17:40 ` Andreas Schwab
2024-01-26 19:45 ` Florian Weimer
2024-01-26 15:13 ` Andreas Schwab
2024-01-26 15:33 ` Alejandro Colomar [this message]
2024-01-26 18:09 ` Russ Allbery
2024-01-26 18:23 ` Alejandro Colomar
2024-01-26 18:36 ` Xi Ruoyao
2024-01-26 18:40 ` Alejandro Colomar
2024-01-26 18:49 ` Xi Ruoyao
2024-01-26 18:57 ` Alejandro Colomar
2024-01-26 18:40 ` Russ Allbery
2024-01-26 18:45 ` Alejandro Colomar
2024-01-26 19:41 ` Florian Weimer
2024-01-26 18:39 ` [PATCH] Use [[gnu::access(none)]] on free(3) Alejandro Colomar
2024-01-26 18:41 ` Alejandro Colomar
2024-01-26 21:23 ` Paul Eggert
2024-01-26 23:19 ` Alejandro Colomar
2024-01-27 13:21 ` Cristian Rodríguez
2024-02-13 15:19 ` Gabriel Ravier
2024-02-13 15:28 ` Alejandro Colomar
2024-01-26 21:11 ` free(3) const void * DJ Delorie
2024-01-26 21:30 ` Andreas Schwab
2024-01-26 21:47 ` DJ Delorie
2024-01-26 22:07 ` Andreas Schwab
2024-01-26 23:25 ` Alejandro Colomar
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