Re: [PATCH] string.h: Mark 34 functions with __must_check

From: Dan Carpenter
Date: Wed Oct 09 2019 - 10:30:55 EST

On Wed, Oct 09, 2019 at 04:21:20PM +0200, Rasmus Villemoes wrote:
> On 09/10/2019 15.56, Dan Carpenter wrote:
> > That's because glibc strlen is annotated with __attribute_pure__ which
> > means it has no side effects.
> I know, except it has nothing to do with glibc headers. Just try the
> same thing in the kernel. gcc itself knows this about __builtin_strlen()
> etc. If anything, we could annotate some of our non-standard functions
> (say, memchr_inv) with __pure - then we'd both get the Wunused-value in
> the nonsense cases, and allow gcc to optimize or reorder the calls.

Huh. You're right. GCC already knows. So this patch is pointless like
you say.

dan carpenter