[PATCH] D25199: [ubsan] Sanitize deleted pointers

[Kostya Serebryany via cfe-commits]

kcc added a reviewer: pcc.
kcc added a comment.

In https://reviews.llvm.org/D25199#559407, @vsk wrote:

> It looks like programs which trip -fsanitize-value-after-delete will just crash without further reporting, which isn't in keeping with the way other ubsan checks are implemented.
>
> IMO, address sanitizer is better-equipped to diagnose this issue.


of course, but asan's overhead is much greater. 
This tool might be fast enough to be always on in production.

The code looks reasonable to me, but as I am not too familiar with clang code, so asking pcc@ to have a look.

Also, please

- update the ubsan documentation
- add a runnable test to compiler-rt/test/ubsan


https://reviews.llvm.org/D25199