[PATCH] D42740: Implement a case-folding version of DJB hash

[Paul Robinson via Phabricator via llvm-commits]

probinson added a comment.

In https://reviews.llvm.org/D42740#994762, @labath wrote:

> In https://reviews.llvm.org/D42740#993464, @aprantl wrote:
>
> > Is this function something that needs to be updated with every new version of Unicode? Should we add a "How to update this for newer versions" comment?
>
>
> That's a good question. The DWARF spec specifically cites the version 9 of the Unicode Standard. This was the latest version at the time dwarf v5 was published, so it's not fully clear whether they meant to hard-code the version or they just meant "the latest".
>
> Currently, the latest version is v10 that came out in June 2017. However, it has no changes in the case folding database, so we don't have to figure this out yet.


I don't remember the discussion that well, but I'd guess the idea was to fix it permanently (or at least permanently for DWARF v5).  Changes to the folding would change the hash for strings that used those characters, which is a Bad Thing.
If there's a change to the case-folding database before DWARF v6 comes out, and the committee notices, the hash might become version-dependent.  But that's years away.


Repository:
  rL LLVM

https://reviews.llvm.org/D42740