[Bug ada/81361] [8 regression] broken exception handling at -O2

[iains at gcc dot gnu.org]

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=81361

--- Comment #13 from Iain Sandoe <iains at gcc dot gnu.org> ---
(In reply to Eric Botcazou from comment #12)
> Bootstrap completed on Darwin with the tentative fix (and the workaround for
> PR target/80556) and the ACATS testsuite is clean.

Also, doing a bootstrap on D15.6 with the patch and the
--with-xxxx-ldflags=-static-libstdc++.

So, FAOD, the fix is a work-around for a bug in either the assembler or
unwinder? (the original DWARF output is expected to be well-formed?)

Given that the GCC unwinder segvs in the same place, perhaps it's more likely
an assembler issue.  Are you using LLVM-backend-based assembler (i.e. via
clang) and, if so, what version?  Like GCC the DWARF code is mostly common in
LLVM, so we should raise an upstream bug report + a radar.

it could be interesting to compare as -q ... with as -Q to see if the bug is
also present in the GAS-based assembler .. dwarfdump --verify and --eh-frame
could be interesting too.

If it's the unwinder, then we can do both there too - but the radar is probably
more important.