[cfe-dev] Proposed: change tracking for RegionStore

[Zhongxing Xu]

On Mon, Aug 2, 2010 at 7:53 AM, Jordy Rose <jediknil at belkadan.com> wrote:
>
> On Sun, 1 Aug 2010 16:23:51 +0800, Zhongxing Xu <xuzhongxing at gmail.com>
> wrote:
>> Are we trying to solve the problem that, some checkers want to be
>> informed when some region bindings are changed?
>>
>> Can we do this:
>>
>> GRExprEngine maintains a RegionWatcher, which is basically a map:
>>       MemRegion *  => list of Checkers who are interested in the
> MemRegion
>>
>> Checkers first register themselves with the region they are interested
>> in to the RegionWatcher.
>>
>> In StoreManager::bind and other necessary places, call
>> RegionWatcher::RegionChanged() with the new store and a list of
>> changed regions. RegionWatcher then inform each Checker that
>> registered before.
>
> That's a good idea. I'd be a little worried transferring from one
> GRExprEngine to the next during far inline calls, but I guess that can wait
> until there's more support for that. (Plenty of checkers, for example,
> assume the ASTContext doesn't change between invocations.) And I assume
> these callbacks would happen at the end of the StoreManager public
> interface methods.

We should try to make more components ASTContext agnostic.

>
> I'd actually still like to push this up to GRStateManager, since that
> would allow checkers to mess with their GDM store as a side effect of a
> region change (in the case of CStringChecker, to invalidate any recorded
> strlen).
>
This makes sense.