bug-gnulib
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: restrict


From: Bruno Haible
Subject: Re: restrict
Date: Mon, 17 Feb 2020 04:53:14 +0100
User-agent: KMail/5.1.3 (Linux/4.4.0-171-generic; KDE/5.18.0; x86_64; ; )

Paul Eggert wrote:
> if GCC generated warnings for that sort of thing, the warnings would be false
> alarms.

Yes, and this in turn means that the ability to produce useful warnings via
'restrict' is limited. In this example:
===================================================================
#include <string.h>
extern void memmcpy (void *restrict, const void *restrict, size_t);

void shuffle (char array[10])
{
  memmcpy (array + 2, array, 8);
  memcpy (array + 2, array, 8);
}
===================================================================
gcc gives no warning about 'memmcpy' - because it does not know
how many elements the function will access. gcc does give a warning
about 'memcpy' - apparently due to custom logic in the compiler.

Bruno




reply via email to

[Prev in Thread] Current Thread [Next in Thread]