Miscompiled C++ code? _Unwind_Resume_or_Rethrow

Hi all,

A large open source C++ project I work with has just recently become
compilable by clang++ (trunk). It builds with many other compilers on
many OSes. However, the result seems broken. Fully half of the unit
tests crash when run. This is not the case elsewhere.

The backtrace (on Mac OS BTW) always shows one or more threads in
_Unwind_Resume_or_Rethrow, and one of those threads is the one that's crashed.

Is that a clue? Assuming yes :), any advice on narrowing this down?


This could be one of several different things; it is probably at least
related to PR8098, if not necessarily a dupe.