[polly] Add diagnostic remark for ReportVariantBasePtr

[Tobias Grosser]

On 26/06/2014 13:54, Andreas Simbuerger wrote:
> This adds a diagnostic remark for variant base pointers found inside loops.
>
> Question:
>   I'm not sure how to enhance the precision of the diagnostic remark because
>   the debug information gathered in the test case is very limited. Has
>   someone an idea how to generate & find debug info that delivers more precise
>   information than 'somewhere in this assignment'?

Very nice. I like such kind of incremental/small patches.

To my understanding there should be debug info on the base pointer that 
gives you the name of the Pointer 'A' (not by looking at the LLVM-IR 
name, but the name in the original source code).

You might also be able to find column infos, but that may not always be 
available.

It already looks good to me, but if you feel like extending the 
precision of this, you are very much invited to do so.

Cheers,
Tobias