Re: [PATCH] pthread_cleanup_push macro generates warning when -Wclobbered is set

[Florian Weimer <fweimer at redhat dot com>]

On 11/14/2017 10:47 PM, Joseph Myers wrote:
> On Tue, 14 Nov 2017, Florian Weimer wrote:
>
> > Your test case already used an indirect call before the change with GCC 7.  I
> > think we should try to fix this in GCC.  GCC 4.8 used to generate a direct
> > call here, so this is a minor regression in the area of security hardening.
>
> How do you suggest the compiler could tell that longjmp is only ever
> called from the same iteration of the outer loop as setjmp?

I'm not sure if I understand your question correctly.

The jump buffer does not even live as long as one iteration of the loop, 
so it necessarily has to be the same iteration.

Thanks,
Florian