Re: [PATCH RFC] Add debuginfod support to objdump and readelf

[Nick Clifton <nickc at redhat dot com>]

Hi Aaron,

> Since there does not appear to be a
> straightforward way to get a build-id from Filedata, readelf's
> get_build_id iterates through the file's ELF notes searching for
> NT_GNU_BUILD_ID. The code borrows a lot from process_notes_at,
> including separate handling of IA-64 files. Should this separate
> handling for IA-64 remain or does it just result in clutter?

Yes.  Best to be safe in this area I think.

> One feature of the debuginfod client library is the ability to attach
> a user-defined progress update function to a query that prints
> information during a download such as the size of the file being
> downloaded or the completion percentage of the download. This patch
> does not make use of this feature. Should it be added?  

As an extra option yes.  I think that the default should be to not
display anything though.

> Any other comments or suggestions are appreciated.

It would helpful if you could include updates to the binutils/NEWS
and binutils/doc/binutils.texi files as well.  It would also be
really nice if you could create some new entries in the binutils 
testsuite to check the feature, but I can see how this might be
rather hard to do.

I am slightly worried however about adding a new dependency to the
binutils, albeit one that is only needed if enabled via a configuration
option.  Is the database querying code in libdebuginfod complex ?
Maybe it could be separated out into a separate library (ie not part of
elfutils) or even imported directly into the binutils sources.
(This probably is a bad idea, but I just wanted to check).

The configure check does not appear to work correctly.  I tried the
following:

  % mkdir /dev/shm/test
  % cd /edv/shm/test
  % /work/sources/binutils/current/configure --quiet --with-debuginfod --enable-gold
  % make all-binutils
  mkdir -p -- ./intl
  Configuring in ./intl
  mkdir -p -- ./binutils
  Configuring in ./binutils
  configure: error: debuginfod is missing or unusable
  make: *** [Makefile:3566: configure-binutils] Error 1

So the configure succeeded, but the build failed.  (This was on an 
x86_64 box running Fedora 29).

Cheers
  Nick