Re: [PATCH] tree-optimization/107561 - reduce -Wstringop-overflow false positives

[Jeff Law <jeffreyalaw@gmail.com>]

On 3/29/23 06:11, Richard Biener via Gcc-patches wrote:
> The following tells pointer-query to prefer a zero size when we
> are querying for the size range for a write into an object we've
> determined is of zero size.  That avoids diagnostics about really
> varying size arguments that just get a meaningful range for example
> because they are multiplied by an element size.
> 
> I've adjusted only one call to get_size_range since that's what
> I have a testcase for.  I think this is the most sensible
> "workaround" for some of the false positives we see.
> 
> Bootstrapped on x86_64-unknown-linux-gnu, testing in progress.
> 
> OK if it succeeds?
> 
> Thanks,
> Richard.
> 
> 	PR tree-optimization/107561
> 	* gimple-ssa-warn-access.cc (get_size_range): Add flags
> 	argument and pass it on.
> 	(check_access): When querying for the size range pass
> 	SR_ALLOW_ZERO when the known destination size is zero.
> 
> 	* g++.dg/pr71488.C: Remove XFAILed bogus diagnostic again.
> 	* g++.dg/warn/Warray-bounds-16.C: Likewise.
OK.
jeff