Gary Guo comments

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                                            Gary Guo

`_Unwind_GetIP` returns `0x0`, and then jumps to it.

Could you provide a MCVE?

What registers should be restored/saved by save_context and restore_context?

For the save routine, saving caller-saved registers are moot because these register can be considered already-clobbered when _Unwind_RaiseException is called. For restore, I play a bit conservative and restore all...

What registers should be restored/saved by save_context and restore_context?

I have no much experience with MIPS, but in RISC-V, callee-saved FP registers need to restored. For example, in https://godbolt.org/z/6aKvv5EcE you can see the landing pad uses `fmv.s fa0, fs0`...

What registers should be restored/saved by save_context and restore_context?

For RISC-V we use `cfg(target_feature = "d")` to detect FP support. Is there no equivalent for MIPS?

What registers should be restored/saved by save_context and restore_context?

I guess "soft-float" should be used then.

.eh_frame for unwinding crate itself missing?

I think for riscv64gc-unknown-none-elf panic=abort is the default?

Build failure on aarch64 and riscv64 with recent nightlies

I guess I could check the IR to see where resume calls are generated, and try to tweak the code to not generate them... This will be fragile though

Build failure on aarch64 and riscv64 with recent nightlies

BTW I tried to reproduce this on my x64 machine with rustc cross-compiling to aarch64 and riscv64 but can't reproduce it. Maybe Rustc's LLVM is compiled with different flags on...

Build failure on aarch64 and riscv64 with recent nightlies

Ah I can produce it by downloading the prebuilt standard library, but not with `-Zbuild-std`, weird.

Build failure on aarch64 and riscv64 with recent nightlies

It looks like things work with a non-zero `opt-level` even with debug info enabled. @sunfishcode maybe you workaround on c-ward side by something like this while waiting for LLVM fix...