Re: free(3) const void *

[Alejandro Colomar <alx@kernel.org>]

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Hi Xi,

On Sat, Jan 27, 2024 at 02:49:42AM +0800, Xi Ruoyao wrote:
> Back on the topic, IMO you may tell others to create wrappers like
> 
> [[gnu::access(none, 1)]] static inline void
> aggressive_free (const void *p)
> {
>   (free) ((void *)p);
> }
> #define free(x) aggressive_free (x)
> 
> with some texts to explain all the caveats (like `free ("string
> literal");` will be incorrectly accepted, and the glibc.malloc.perturb
> or similar facilities in other malloc implementations, etc) in the man
> page...  But for the standard and/or the libc header it's a different
> story.  Anyway if such a wrapper is adopted widely it will be easier to
> raise it to WG14 and Austin.

Sure!  I'll play with that in the following days, and will write
something in the manual page about it.  I raised the topic because for
fixing a const-correctness warning in shadow-utils, I had to make a
pointer non-const for its entire lifetime, and the only call that
required non-const was free(3), which was awkward.  So, I'll definitely
write a free(3) wrapper in shadow utils.  I also had similar problems
about const in Nginx last week.  Let's see if this catches up.  :)

I'll ask you about it if I have any doubts.

Have a lovely night,
Alex

-- 
<https://www.alejandro-colomar.es/>
Looking for a remote C programming job at the moment.

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