RFR: 8360791: [ubsan] Adjust signal handling when using clang

[Kim Barrett]

On Fri, 27 Jun 2025 21:13:32 GMT, Magnus Ihse Bursie <ihse at openjdk.org> wrote:

>>> I agree, this does not seem to be limited to clang, unless the signal handling stuff differs in ubsan in different compilers.
>> 
>> I only see issues with clang (on macOS and AIX) ;  the Linux platforms using gcc are fine.
>
> This does not seem to be something related to compiler. I guess there might be other environmental factors determining if you encounter this as a problem or not. Given that we know that we do these things with signals, on all unix platforms, then it makes sense to tell ubsan about it.

Does the same problem arise when building with clang on linux?  I tried it, but ran into some linking errors
that I don't understand, and I've not done much with ubsan before.


ld.lld: error: non-exported symbol '__ubsan_handle_type_mismatch_v1' in '/usr/bin/../lib/clang/19/lib/aarch64-redhat-linux-gnu/libclang_rt.ubsan_standalone.a(ubsan_handlers.cpp.o)' is referenced by DSO '/home/kab/gitsb/ubsan-vs-signals/fastdebug/hotspot/variant-server/libjvm/gtest/libjvm.so'

and similarly for a bunch of other ubsan functions. I expect these are some configuration issue on my end,
but I'm not going to try digging into it right now.

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PR Review Comment: https://git.openjdk.org/jdk/pull/26015#discussion_r2173110905