Re: [bug #60798] Make does not compile with GCC 11.1.0

[Paul Smith]

On Sat, 2021-06-19 at 15:31 +0100, Dmitrii Pasechnik wrote:
> On Fri, Jun 18, 2021 at 12:53:32PM -0400, Paul D. Smith wrote:
> 
> > Follow-up Comment #1, bug #60798 (project make):
> > FWIW, this warning is not valid in this situation.  The code is
> > correct; p will always be pointing into a valid buffer and never
> > pointing at the first character in that buffer, so p[-1] always
> > points to valid memory.
> 
> It's undefined behaviour in C to point to such a location, isn't it?

To point to which such location?  As I said, we know for a fact that p
does not point at the first character of the array.  It's clearly legal
in C to walk backwards through an array!!  And referencing the previous
element in an array is certainly not a hack.

I don't think I understand.