[LLVMdev] summer of code idea — checking bounds overflow bugs

[John Regehr]

John-- a couple questions:

Can you explain the SAFECode model in a bit more detail?  I am getting 
conflicting information.  On one hand, some of the papers describe a 
system that is primarily designed to hide safety violations.  On the other 
hand, the 2006 ICSE paper that I cited earlier today seems to be talking 
about catching violations.  These are very different goals!  What does the 
code in the SAFECode repository actually do?

Can you comment on the speed of LLVM when shelling out to Omega?  My guess 
would be that this will result in unacceptable compile times for large 
software, and that something fast and relatively simple like ABCD is a 
better choice for general usage.

Finally a comment: it's a clear that a comprehensive system for trapping 
undefined behavior in Clang is a multi-year project.  Some parts of this 
must live in Clang.  Some parts, such as bounds check optimizations, 
should go into LLVM passes.  Anyway I'm just saying that the project you 
outlines seems to fit very well into the overall vision of detecting 
undefined behavior in C programs.

John