Will eu-addr2line support debuginfod?

[Mark Wielaard]

Hi,

On Tue, 2020-12-01 at 10:23 -0500, Frank Ch. Eigler via Elfutils-devel
wrote:
> Is it planned to have eu-addr2line supporting debuginfod? I try to
> > pass '[build-id]@address' (in the same format that eu-stack
> > outputting)
> > without success [...]
> 
> For a broader discussion of the same topic, see:
>      https://sourceware.org/bugzilla/show_bug.cgi?id=25793
> I remain of the opinion that all elfutils tools should automagically
> attempt debuginfod queries, if they encounter incomplete data.
> 
> If we cannot overcome objections to that, we may end up having to
> invent a new elfutils tool that does general elf/dwarf dumping.

I think that is a different discussion.
eu-addr2line and eu-stack will already query a debuginfod server when
DEBUGINFOD_URLS is set (and the debuginfo isn't already available
locally).

The discussion about eu-readelf is that the utility itself doesn't
really deal with DWARF except that it dumps the data contents of
sections containing DWARF. We could introduce an option like binutils
has, --debug-dump=follow-links, which could drop. This would be
somewhat like the current --debug-dump=info+ which follows links to
split DWARF files. I just don't understand (or maybe I do, but don't
like) the semantics of --debug-dump=follow-links. It seems somewhat
imprecise and arbitrary IMHO.

The question is whether eu-addr2line could accept a new kind of address
specification that include the build-id like how eu-stack -b produces
output.

I guess we could, but is that really something people would use?
eu-stack -b shows module build-id, load address and pc offset. Which
can be mapped back to the actual (relative address) inside the build-
id.

Is '[c017df57d6194b6479cef409cba575bbaa537c94]@0x7ffa8d3c5000+0xfd886'
really something people want to query eu-addr2line about? We would
basically throw away the load address, and just use build-id + offset.
So something like c017df57d6194b6479cef409cba575bbaa537c94+0xfd886
would be fine.

If you think something like that is useful, then please do open a bug
report https://sourceware.org/bugzilla/enter_bug.cgi?product=elfutils

Thanks,

Mark