Patch: Add __restrict to string.h

[Craig Howland]

On 07/19/2013 05:55 AM, Corinna Vinschen wrote:
> On Jul 18 17:42, Joel Sherrill wrote:
>> I was leaning that way but waffled. Anyone else want restrict in the docs?
> Yes, that makes sense, following SUS docs.
>
>
> Corinna
>
We should be using "restrict" everywhere, not only in the docs.  The C standard 
defines restrict as a keyword, just as it does const, volatile, etc.  And it has 
been standard for more than 13 years.  We do not use __const in headers, even 
though before C89 it was not standard but available as a GCC extension.  So 
while 15 years ago using __restrict would have made sense, it is not appropriate 
now.

$ cd libc/include
$ grep __const *.h | wc -l
1
$ grep const *.h | grep -v __const | wc -l
402

I do realize that this does not fit exactly with the sys/cdefs.h which has 
recently been brought into sync with FreeBSD, but this would be a trivial 
difference.  This type of thing--having gratuitous differences from the 
standard--will only lead to confusion and questions among the majority of 
maintainers.  Why is it this way?  Etc.  Then we'll need someone in the know to 
explain. You get the point.  While I do see the advantages of trying to be the 
same, we should not be blindly using someone else's excess baggage (or 
13.5-year-old extension diction).

We're making a new start on restrict in newlib.  (Thank you, Joel, for starting 
the ball rolling.)  We should make it clean.

Craig

(Sorry for the lag on this, but I was away.  Joel, if you'd like, I'd even edit 
your patch to make the change.)