EarlGrey 2.0 | Incompatibility with LLVM ASAN

There are issues when running EarlGrey with Address Sanatizer (ASAN) (or TSAN/UBSAN) enabled. These sanitizers _also_ hook some of the same methods (e.g. dispatch_async, dispatch_sync, etc...) that EarlGrey hooks as well. The LLVM wrappers for these functions happen before the EarlGrey wrappers are hooked.

When tests call these wrapped functions, it first goes into the EarlGrey wrapper, which then calls what it suspects to be the original implementation of these methods, but is instead the LLVM sanitizer wrapper, which then makes a call back to what _it_ thinks is the original function, which is actually the EarlGrey wrapper. This causes an infinite loop.

The resulting stack trace looks like this:

grey_dispatch_async
wrap_dispatch_async
grey_dispatch_async
wrap_dispatch_async
grey_dispatch_async
wrap_dispatch_async
...
...
...

It would be really nice for me to be able to run my EarlGrey test suite under these sanitizers, to test for additional breakages. Is there a way that both of these wrappers can coexist in a way that would allow for this?

Start by reproducing the recursion with EarlGrey and LLVM ASAN, TSAN, or UBSAN enabled, then trace the interaction between the named grey_dispatch_async and wrap_dispatch_async wrappers. Done means the EarlGrey test suite can run under these sanitizers without wrapper recursion.

Written by the indexing model from the issue text.