[LLVMdev] Linker Question

[Chris Lattner]

On Oct 5, 2009, at 3:31 PM, David Greene wrote:

> On Monday 05 October 2009 17:21, Chris Lattner wrote:
>
>>> Would it break things horribly if I went in and taught
>>> RecursiveResolveTypes
>>> how to handle this or would that violate some deep-level assumption?
>>
>> This is intentional, but instcombine should clean it up.  Are you not
>> seeing this?  If not, instcombine should be improved.
>
> The problem is I need to examine this before instcombine and do  
> various
> nefarious things like spitting out IR and/or generating code without  
> any
> modifications to improve debuggability of our compiler.  Why is this
> intentional?

It is intentional because there are two things going on here: the  
linker needs to unify the prototypes, then something needs to massage  
the call to pass the arguments to the new prototype.  Just violating  
the type system won't work.  Doing this in two steps (the linker does  
something simple and always correct + instcombine improving  
performance/analyzability) is much better than the old and buggy thing  
we had before where the linker tried to do both.

-Chris