A shiny revised version of my unwind-through-signal code for ARM EABI: https://github.com/mvduin/arm-signal-unwind/
For actual unwinding it now uses sigreturn as a cleanup handler (after diddling the ucontext to make it land right onto a call to _Unwind_Resume), which means that all state should get properly restored by the kernel. Virtual unwinding still only restores core registers, but hopefully that isn't too big a problem in practice. A small test is included that confirms throwing exceptions out of SEGV, checks VFP is restored properly, and that returning normally from an async signal handler still works (my original patch accidently broke that). I'd finally like to take a moment to say this was hell to figure out.... this shit is really documented nowhere properly since it appears to be a magic blend of ARM EABI and IA64 C++ ABI (meaning neither documentation quite applies) and I had to plow through the innards of libgcc and libsupc++ to figure out how things *actually* work. Argh. Anyhow, it only took four years, but you can now throw NullPointerExceptions on ARM. Enjoy. ;-) Matthijs van Duin
