[PATCH] D91968: llvm/ADT/StringExtras.h hexDigitValue - Init of integer buffer

[Duncan P. N. Exon Smith via Phabricator via llvm-commits]

dexonsmith added a comment.

In D91968#2425795 <https://reviews.llvm.org/D91968#2425795>, @jerker.back wrote:

> In D91968#2424469 <https://reviews.llvm.org/D91968#2424469>, @dexonsmith wrote:
>
>> In D91968#2412092 <https://reviews.llvm.org/D91968#2412092>, @joerg wrote:
>>
>>> Do we really want to change the code here? It is perfectly well defined behavior.
>>
>> I weakly agree with @joerg, I would have thought we have lots of cases of `-1U` since it's a common / well-understood way to get this value. Is the warning possible to turn off? Have you reported a compiler bug?
>
> As I said in the beginning, this is a compiler warning turned into an error by a default compiler option (-sdl, Security Development Lifecycle (SDL) checks). The option can be turned off. It's a bit unclear under what conditions exactly the option is default, off or disabled. The issue is well known and not a bug.

Well, it seems like a bigger decision than just this patch, since there are 306 instances of this in llvm-project:

  $ git grep -e -1U | wc -l
       306

I don't know if you were planning to change them all one-by-one, but it seems like a policy change if we're going to disallow this literal. Personally I find `-1U` more readable than `~0U` and certainly easier to type (there are 121 of those, too, though).

I don't feel that strongly one way or the other, but this might deserve a discussion on llvm-dev.


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  https://reviews.llvm.org/D91968/new/

https://reviews.llvm.org/D91968