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Re: [PATCH] treat -Wxxx-larger-than=HWI_MAX special (PR 86631)
On 07/26/2018 02:38 AM, Richard Biener wrote:
On Wed, Jul 25, 2018 at 5:54 PM Martin Sebor <firstname.lastname@example.org> wrote:
On 07/25/2018 08:57 AM, Jakub Jelinek wrote:
On Wed, Jul 25, 2018 at 08:54:13AM -0600, Martin Sebor wrote:
I don't mean for the special value to be used except internally
for the defaults. Otherwise, users wanting to override the default
will choose a value other than it. I'm happy to document it in
the .opt file for internal users though.
-1 has the documented effect of disabling the warnings altogether
(-1 is SIZE_MAX) so while I agree that -1 looks better it doesn't
work. (It would need more significant changes.)
The variable is signed, so -1 is not SIZE_MAX. Even if -1 disables it, you
could use e.g. -2 or other negative value for the other special case.
The -Wxxx-larger-than=N distinguish three ranges of argument
values (treated as unsigned):
1. [0, HOST_WIDE_INT_MAX)
3. [HOST_WIDE_INT_MAX + 1, Infinity)
But it doesn't make sense for those to be host dependent.
It isn't when the values are handled by each warning. That's
also the point of this patch: to remove this (unintended)
I think numerical user input should be limited to [0, ptrdiff_max]
and cases (1) and (2) should be simply merged, I see no value
in distinguishing them. -Wxxx-larger-than should be aliased
to [0, ptrdiff_max], case (3) is achieved by -Wno-xxx-larger-than.
I think you are over-engineering this and the user-interface is
I agree that what you describe would be the ideal solution.
As I explained in the description of the patch, I did consider
handling PTRDIFF_MAX but the target-dependent value is not
available at the time the option argument is processed. We
don't even know yet what the target data model is.
This is the best I came up with. What do you suggest instead?