Re: [PATCH 1/3] diff --stat: allow custom diffstat output width.

From: Linus Torvalds <torvalds@osdl.org>
Date: Sep 29, 2006, 05:58 UTC
Message-ID: <Pine.LNX.4.64.0609282252430.3952@g5.osdl.org>
In-Reply-To: <7vr6xvp7jm.fsf@assigned-by-dhcp.cox.net>

On Thu, 28 Sep 2006, Junio C Hamano wrote:

Show 5 quoted lines

> 
> This is simply too clever; -pedantic does not like assignment of
> arg to end (constness -- and strtoul takes pointer to non-const
> char *, so making the type of end const char * is not an answer
> either).

The _code_ really is right. The problem is "strtoul()" interfaces and a C typing oddity.

> And I do not like casting constness away: end = (char *) arg.

You could fix it by doing something like this:

	static inline unsigned long sane_strtoul(const char *n,
						 const char **p,
						 int base)
	{
		char *end;
		unsigned long res;

		res = strtoul(n, &end, base);
		*p = end;
		return res;
	}

because the only reason strtoul() warns now is that C type-rules don't allow the (obviously safe - but pointers migth have strange representations) conversion of "char **" into "const char **", even though "char *" can be converted into "const char *".

At that point, the cast is probably simpler, but the above should be strictly correct pedantic ANSI C.

I didn't even try it, though.

			Linus