[LLVMdev] Proposal: type uniquing of debug info for LTO

[Robinson, Paul]

> From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu]
> On Thu, Jun 20, 2013 at 10:52 PM, Manman Ren <mren at apple.com> wrote:
> > ---------------------
> > Option b) I am going to expand David's description with more details,
> correct me if I am wrong.
> 
> I'll let David continue this part of the thread with you.
> 
> >
> > I personally prefer option b over a since it is much cleaner.
> >
> 
> Option b is more general and should probably work. I suggested a
> originally because I know it would work and the impact is limited to
> debug info. Also it doesn't involve touching the generic metadata
> interface or code and could be done quickly and incrementally. b may
> also require further changes to the debug info infrastructure to deal
> with lookup, etc so may end up being as much churn as a. b is more
> useful if we think other users of metadata may want/need similar
> functionality in the future.

I can't say I've followed all the details but would this be useful
in moving toward support of .debug_types at all?  There's a
superficial resemblance in conjuring up hashes of types referenced
from elsewhere, and I can't help wondering if the resemblance is
any deeper than that.  (I'm not insisting that it has to be, at
worst it shouldn't get in the way if we can anticipate what would
be required for .debug_types to work.)

Thanks
--paulr