[Rpm-maint] [PATCH] RFC: Add build-id links to rpm for all ELF.

[Mark Wielaard]

Hi all,

On Wed, 2016-04-13 at 20:59 +0200, Mark Wielaard wrote:
> This is an RFC patch to move the main ELF file build-id symlinks
> from the debuginfo package into the main package and to use a
> different base directory for the main ELF file build-id symlink.
> Use /usr/lib/.build-id instead of /usr/lib/debug/.build-id
> 
> There are two reasons for doing this. The main package and the
> debuginfo package might get out of sync, or the debuginfo package
> might not be installed at all. In which case finding the main ELF
> file through the build-id symlink becomes impossible. Secondly by
> moving the main ELF build-id symlink in its own directory the
> /usr/lib/debug directory gets populated with only debuginfo files
> which is convenient if the user might want to have that directory
> populated through a network mountpoint.
> 
> This patch is still a work in progress. It seems to work, but might
> not be the best way to implement the above idea. The idea itself
> might not be perfect (comments more than welcome). I tried to
> follow the rpm coding style as much as I understood it. Please let
> me know if I use some wrong constructs, or if there are alternate
> ways to do what I am doing. It contains one testcase, that is fairly
> minimal. I'll add more if we agree on the semantics of the idea
> (help writing better testcases also very welcome). It obviously will
> need some config setting (pointers to examples that use configs
> for this kind of rpmbuild settings would be appreciated). And it
> needs corresponding adjustments to scripts/find-debuginfo.sh,
> including, when enabled, a backwards compatible link from the old
> /usr/lib/debug/.build-id/xx/yyy -> /usr/lib/.build-id/xx/yyy
> 
> Comments, ideas and suggestions how to move a change like this
> forward more than welcome.

I am integrating this patch with the patches I posted that integrate the
debuginfo package handling from fedora and the new testcases and wanted
to make the behavior configurable so a distro can setup a macro to
define what they want. Does the following make sense?

# Defines how and if build_id links are generated for ELF files.
# The following settings are supported:
#
# - none
#   No build_id links are generated.
#
# - debug
#   build_id links are generated only when the __debug_package global is
#   defined. This will generate build_id links in the -debuginfo package
#   for both the main file as /usr/lib/debug/.build-id/xx/yyy and for
#   the .debug file as /usr/lib/debug/.build-id/xx/yyy.debug.
#   This is the old style build_id links as generated by the original
#   find-debuginfo.sh script.
#
# - separate
#   build_id links are generate for all binary packages. If this is a
#   main package (the __debug_package global isn't set) then the
#   build_id link is generated as /usr/lib/.build-id/xx/yyy. If this is
#   a -debuginfo package (the __debug_package global is set) then the
#   build_id link is generated as /usr/lib/debug/.build-id/xx/yyy.
#
# - compat
#   Same as for "separate" but if the __debug_package global is set then
#   the -debuginfo package will have a compatibility link for the main
#   ELF /usr/lib/debug/.build-id/xx/yyy -> /usr/lib/.build-id/xx/yyy
%_build_id_links compat

Let me know if this makes sense and I will implement it and write some
testcases for the different settings.

Thanks,

Mark