[PATCH] compress .gnu.debuglto_.debug_* sections if requested

[Alan Modra]

On Tue, Oct 04, 2022 at 10:12:46AM +0200, Martin Liška wrote:
> On 10/4/22 10:07, Alan Modra wrote:
> > On Fri, Sep 30, 2022 at 09:19:49AM +0200, Martin Liška wrote:
> >> 	* write.c (compress_debug): Compress also ".gnu.debuglto_.debug_"
> >> 	if the compression algorithm is different from zlib-gnu.
> > 
> > OK, choosing to skip compression for zlib-gnu is a reasonable approach
> > given that zlib-gnu has the clunky .debug_* to .zdebug_* section
> > renaming scheme.  I'm going to commit your patch, but then enable
> > zlib-gnu with a followup patch of mine that doesn't rename the lto
> > debug sections.  ld.bfd and the binutils work fine without renaming,
> > but there may be some other reason why zlib-gnu must have .zdebug
> > sections.  If that turns out to be the case, my patch below can be
> > reverted.
> 
> Makes sense. On the other hand, I would somehow slowly (but surely) make zlib-gnu
> obsolete. What do you think?

I don't see that happening in a hurry.  We'd want to keep the ability
to handle zlib-gnu compressed object files for as long as such objects
are still in use.  So decompression will stay supported for a long
time, and since we need to test decompression support it is also
necessary to support compression.

> For the future, people will likely move to the more
> modern and faster zstd compression algorithm. We're planning doing that once
> new binutils is released in openSUSE Tumbleweed.

Sure, that's fine.

-- 
Alan Modra
Australia Development Lab, IBM