[LLVMdev] Union type, is it really used or necessary?

[Chris Lattner]

On Sep 7, 2010, at 2:24 PM, Erik de Castro Lopo wrote:

> Eli Friedman wrote:
> 
>> On Tue, Sep 7, 2010 at 8:16 AM, Talin <viridia at gmail.com> wrote:
>>> Here's a suggestion - can we make the "union patch" (the inverse of the
>>> patch that removed unions) as a downloadable file so that people who are
>>> interested in finishing the work can do so?
>> 
>> Anyone who's really interested in working on it can just use "svn diff
>> -c 112356", and apply it with "patch -R".
> 
> Well I tried that, the patch fails to reverse apply. Out of the
> 34 files touched by the patch, not a single hunk actually manages
> to reverse apply.
> 
> Assuming I was to decide to embark on the effort of getting unions
> back into LLVM:
> 
>  a) What is required for them to be accepted back in?

It needs to work.  When reverted, it was broken in almost all cases.

>  b) What are the chances of getting them in the 2.8 release?

Zero.

-Chris