[cfe-dev] Moving named cast helpers out of Sema

[Chris Lattner]

On Nov 5, 2008, at 11:02 AM, Sebastian Redl wrote:

> Hi,
>
> Attached patch moves the C++ named cast helper functions out of Sema  
> and makes them static functions local to their own file., as  
> requested by Chris. (The patch also moves all named cast stuff to  
> its own file.)

This looks great to me, thanks Sebastian!

> Unfortunately, this requires making a few helper functions that are  
> private in Sema public, so I'm not sure if this patch is a good  
> idea. What do you think?

I think it's the right thing to do.  The entire Sema class is private  
to the sema module.  C++ doesn't have very fine grained access  
control.  For example, in Java, we'd make a bunch of these things  
public within the sema package but private outside it.  In this case,  
it doesn't really matter, since all of Sema is private to the sema  
library (not even in include/clang) so access control is not critical  
here.

Quoeth Daniel:
> If the methods require the Sema object, I don't really think that  
> moving them out of Sema makes sense or makes the code better.

To me, the real issue is that the Sema *class* is really about the  
implementation of the actions module.  Given the shear size of the  
actions interface (which sema must implement) it is a huge class and  
lacks any good modular breakdown.  I'd much rather have complex/ 
involved subsystems split out as static functions where it makes  
sense, just to reduce the size of the sema interfaces and make it more  
clear what is part of the sema interface and part of the sema internal  
implementation details.

Does this seem reasonable?

-Chris