[llvm-commits] [llvm] r109021 - in /llvm/trunk: include/llvm/Metadata.h lib/VMCore/Metadata.cpp

[Chris Lattner]

On Jul 21, 2010, at 11:07 AM, Devang Patel wrote:

> 
> On Jul 21, 2010, at 11:01 AM, Dan Gohman wrote:
> 
>> Author: djg
>> Date: Wed Jul 21 13:01:42 2010
>> New Revision: 109021
>> 
>> URL: http://llvm.org/viewvc/llvm-project?rev=109021&view=rev
>> Log:
>> Use TrackingVH instead of WeakVH for NamedMDNode's operands, since nodes
>> referenced by NamedMDNodes shouldn't be deleted.
> 
> That was not required earlier. Why would you want to impose this restriction ?
> One could manually delete a MDNode for whatever reason. It does not happen for the debug info case though.

In what case is that valid and desirable?  Since MDNodes are uniqued, you don't know what is using them.

-Chris