Re: [PATCH] gas: Add --force-compress-debug-sections

[Pedro Alves <pedro@palves.net>]

On 2023-02-27 11:24 p.m., Tom de Vries wrote:
> On 2/27/23 15:07, Jan Beulich wrote:

> OK, so say we have --compress-debug-sections=none|zlib|zstd|no|yes|sizewin.
> 
> We have the two existing aliases, --compress-debug-sections and --nocompress-debug-sections, how do we translate those?
> 
> Currently --nocompress-debug-sections maps to --compress-debug-sections=none, but I suppose that would have to become --compress-debug-sections=no, otherwise things will get extremely confusing.

Let's drop the new (when) "no" option, as it's not really needed, and rename "yes" -> when-always, and "sizewin" -> "when-always".

So we end up with:

  --compress-debug-sections=none|zlib|zstd|when-always|when-sizewin
                            ^^^^^^^^^^^^^^ ^^^^^^^^^^^^^^^^^^^^^^^^
                                group1           group2


And then the "no" in nocompress-debug-sections is no longer ambiguous.


> 
> Then --compress-debug-sections currently maps to --compress-debug-sections=zlib.  So, should that become --compress-debug-sections=zlib,sizewin?  Or just stay --compress-debug-sections=zlib?  I'm not sure if we have made things clearer or more orthogonal this way.

I think it's clearer to make it map to whatever are the defaults in all subgroups,
so no subgroup is special cased.

The default compression format is zlib, and the default "when" is "sizewin", so:

  "--compress-debug-sections" => "--compress-debug-sections=zlib,sizewin"

And then:

  "--compress-debug-sections=always --compress-debug-sections"  =>   "--compress-debug-sections=zlib,sizewin"

> 
> I'm starting to wonder if not a simple --compress-debug-sections=heuristic-sizewin|heuristic-always is the solution, in the sense that these two would only influence the heuristics and nothing else, which would work well with the existing options.

I prefer "when" (or no leading prefix) to "heuristic", as "always" is not an heuristic, there's no trial
and error nor is it loosely defined what it does.

But that's a nitpick, it's actually fine with me.  FWIW.