Re: [Libunwind-devel] libunwind-1.2 released, patch roundup for 1.3-rc

[Dave Watson]

On 01/13/17 01:22 PM, Yichao Yu wrote:
> Fixing instruction pointer offset on ARM (hopefully non-controversial
> since it's just mirroring x86)
> https://github.com/JuliaLang/julia/blob/fd1495138b72df4e5e68208e032ac184d330bfca/deps/patches/libunwind-arm-pc-offset.patch

looks good, doesn't apply cleanly, looks like it depends on the exidx patch, 
I'll see if I can rework

> Accept newer DWARF version: This one is a total hack and even had a
> typo in it... ;-p. Do you have any plan about doing this more
> properly?
> I was told that DWARF 4 didn't add too much new stuff. Is it possible
> to only complain if a unsupported feature is detected so that we don't
> need to bump this version too often?
> https://github.com/JuliaLang/julia/blob/fd1495138b72df4e5e68208e032ac184d330bfca/deps/patches/libunwind-dwarf-ver.patch

We haven't run in to this yet - it looks like the eh_frame versions
haven't changed, only the debug_info?  Do you have an example I could
look at where it fails?

> Prefer EXIDX unwinding on ARM: This one is also a little hack. In my
> experience the unwind info is more reliable for unwinding than the
> debug info and since it's used by c++ I think it makes sense to use
> that method first.
> https://github.com/JuliaLang/julia/blob/fd1495138b72df4e5e68208e032ac184d330bfca/deps/patches/libunwind-prefer-extbl.patch

I'm not an arm expert, but looks reasonable to me.

> And yet another patch we carry that might be of general interest.
> https://github.com/JuliaLang/julia/blob/fd1495138b72df4e5e68208e032ac184d330bfca/deps/patches/libunwind-freebsd-mapper.patch

Someone else mentioned this as well. Applied as
09a598a3da5091f4f2cb522a0948d768c63de611, thanks.

Thanks