On 10/31/12 1:39 PM, "Paul Hargrove" <phhargr...@lbl.gov> wrote:
>No, I don't have specific usage cases that concern me. > > >As I said a minute or two ago in a reply to Ralph, my concern is that the >Sandia codes provide an "existence proof" that "really smart people" can >write questionable code at times. So, I fear that a larger-than-expected >fraction of real codes would generate warnings. Not surprisingly, most of the codes I'm concerned about are really old (like pre-MPI old). The authors were dealing with more than one communication library, so they wrote wrappers inside their code for communication. The wrappers were for a bunch of different communication interfaces and so fairly agnostic, but looked a lot like MPI (because MPI looks a lot like NX, PVM, etc.). Anyway, they squashed down everything to either a void* or char* (remember, this is when void* was not always supported), passed that to MPI with a datatype, and off we go. At present, we're not using clang as the front end. However, a lot of developers of these codes do a lot of development on their Mac laptops, meaning that they will be using clang in the not-too-distant future. And since their usage of MPI is not wrong, I'd have some objection to them getting warnings. That said, if we didn't throw a warning if the pointer is of type void* or char*, I think I'd be mostly ok with the patch being on by default. I'm not sure if that's possible or not... Brian -- Brian W. Barrett Dept. 1423: Scalable System Software Sandia National Laboratories
