Bug#939656: dh_strip should strip sections with LTO information from .a and .o files / lintian should warn about these

[Niels Thykier <niels@thykier.net>]

Control: tags -1 moreinfo

Matthias Klose:
> Package: debhelper,lintian
> Severity: important
> 
> Some packages build with link time optimizations enabled, which is ok,
> whoever then these packages may ship with static libs which still have
> the LTO information in some sections of the object files (e.g.
> ext2fsprogs).  This is not desired in most cases, so this information
> should be removed from these files, and not shipped in the archive. Plus
> the streaming format for the LTO information changes (even in GCC minor
> releases), and leads to build errors when you try to use an old
> streaming format with a newer compiler.  I'm asking for
> 
>  - dh_strip removing sections, as in
> 
>      strip -R .gnu.lto_* -R .gnu.debuglto_* -N __gnu_lto_slim -N
> __gnu_lto_v1
> 
>    which is turned on by default.
> 
>  - dh_strip providing an option not to remove these sections.
> 
>  - lintian warning about object files and static archives having such
>    sections.
> 
> I'd like to see that implemented in debhelper, because LTO builds are
> also sometimes enabled in upstream sources.
> 
> LTO is turned on by default in Suse, and their dh_strip equivalent
> provides the functionality above for the removal of the LTO information.
> 
> Please feel free to split this issue into separate debhelper and lintian
> tasks once a solution is agree upon.
> 

When would you need to keep these LTO sections (but not use -k to keep
everything)?

Thanks,
~Niels