[cfe-commits] r105882 - in /cfe/trunk: include/clang/AST/Decl.h lib/AST/Decl.cpp lib/Sema/SemaDecl.cpp lib/Sema/SemaTemplate.cpp

[Ted Kremenek]

On Jun 15, 2010, at 3:47 PM, Douglas Gregor wrote:

> 
> On Jun 15, 2010, at 3:16 PM, Ted Kremenek wrote:
> 
>> 
>> On Jun 15, 2010, at 3:09 PM, Daniel Dunbar wrote:
>> 
>>>> However, we don't really use the Destroy methods consistently, so they're in a state of disarray. There has been some discussion of eliminating them entirely (and committing to the BumpPtrAllocator model fully), but I don't think we're ready to commit to that (or to making all of the Destroy methods perfect) yet.
>>> 
>>> What is left to get us to commit to that? :)
>>> 
>>> - Daniel
>> 
>> For me there is the issue about clients that want to modify the AST after it is built by Sema.  Do we really want all pieces of the AST to stay around, even if they are no longer referenced?
> 
> 
> It's not clear to me that it will be reasonable to implement such clients. Removing anything from the AST is risky business, since there might be references into the part of the AST you're removing. We might be better off with a "transform + copy" approach to AST modification, based on the ASTImporter or TreeTransform.
> 
> 	- Doug

I'd be very happy to take a functional approach to transforming the AST, which is what is done in CIL.  There is still the issue of reclaiming memory no longer referenced by the "newer" AST once we drop the reference to the "old" AST.