r206986 - Replacing a naked pointer with a unique_ptr. No functional changes intended.

[David Blaikie]

On Wed, Apr 23, 2014 at 10:18 AM, Aaron Ballman <aaron at aaronballman.com> wrote:
> On Wed, Apr 23, 2014 at 1:08 PM, David Blaikie <dblaikie at gmail.com> wrote:
>> On Wed, Apr 23, 2014 at 7:26 AM, Aaron Ballman <aaron at aaronballman.com> wrote:
>>> Author: aaronballman
>>> Date: Wed Apr 23 09:26:59 2014
>>> New Revision: 206986
>>>
>>> URL: http://llvm.org/viewvc/llvm-project?rev=206986&view=rev
>>> Log:
>>> Replacing a naked pointer with a unique_ptr. No functional changes intended.
>>
>> Any particular reason this needs to be dynamically allocated (it
>> doesn't appear to be polymorphic - but perhaps it will be in the
>> future?)? Would Optional<CallingContext> suffice?
>
> I think it would be possible to do -- CallingContext::Prev would have
> to change to be Optional<CallingContext> Prev,

Well, that wouldn't work (then you'd have an infinitely recursive type
- optional has inline storage, so if a T has an Optional<T> then T has
to be infinitely large), but it doesn't need to - it can remain as a
non-owning pointer. (we could add a utility to Optional<T> to retrieve
a T*, null if the Optional has no current value, if it doesn't already
have such an operation)

>but I don't see the
> extra copies being overly expensive. I'll let DeLesley make the call
> since this is in perf-sensitive code.
>
> ~Aaron