[PATCH v2] Limit BFD_SUPPORTS_PLUGINS check to plugin.h and targets.c

[H.J. Lu]

On Sun, Aug 17, 2025 at 6:32 PM Alan Modra <amodra@gmail.com> wrote:
>
> On Sun, Aug 17, 2025 at 07:58:45AM -0700, H.J. Lu wrote:
> > On Sun, Aug 17, 2025 at 6:00 AM Alan Modra <amodra@gmail.com> wrote:
> > >
> > > On Sat, Aug 16, 2025 at 03:05:49PM -0700, H.J. Lu wrote:
> > > > Minimize the BFD_SUPPORTS_PLUGINS check to make code more readable and
> > > > maintainable by:
> > > >
> > > > 1. Update bfd_check_format_matches to require the plugin target for slim
> > > > LTO IR object if it isn't a linker input.
> > >
> > > I already said I didn't like this part.  You haven't given me any
> > > reason to change my mind.
> >
> > Only linker doesn't use the BFD plugin target on slim IR objects.  Everyone
> > else should use the BFD plugin target on slim IR objects.
>
> That is just an assertion.
>
> >  There is no need for
> > ar, nm, objcopy to use the BFD plugin target explicitly.
>
> The plugin target needs to be used so that archive maps pick up LTO IR
> symbols, and so that nm displays LTO IR symbols by default.  It is
> true that we might be able to enable the plugin target inside BFD.  I
> thought about doing that in check_format, something along the lines of
> checking for a plugin target match first before the current target if
> bfd_object and target_defaulted and not a linker input.  I decided
> against doing that, because I wanted to make incremental changes in
> removing plugin archive support.  I also wanted to minimise the number
> of places that do something special for LTO IR, and document those
> that are necessary with comments giving the reason.
>
> Removing all of the places in binutils/ that set the target to
> "plugin" was on my list of things to do, but that should not be a
> special case for slim LTO only.  We usually want to see LTO IR symbols
> for fat LTO, don't we?

Linker never uses the BFD plugin target.  For others, the non-IR symbols
are no different from IR symbols in fat IR objects.

> Also, minimising BFD_SUPPORTS_PLUGINS should be a separate patch.  I
> quite like that part of your change BTW.
>

I will make it a separate patch.



-- 
H.J.