Pass gdbarch, not regset, to supply regset et.al.?

[Andrew Cagney <ac131313@redhat.com>]

Mark,

I'm wondering if it would be easier to explicitly pass the gdbarch 
instead of the regset to the regset function?

At present the lookup regset code does this:

           tdep->gregset = XMALLOC (struct regset);
           tdep->gregset->descr = tdep;
           tdep->gregset->supply_regset = i386_supply_gregset;

so that the architecture is tunneled through to the regset function.

   const struct gdbarch_tdep *tdep = regset->descr;
   ...
   for (i = 0; i < tdep->gregset_num_regs; i++)

I'm wondering if it would be easier to just pass the architecture?

At the same time, I'm wondering if i386_regset_from_core_section should 
be abstracted a little so that, like reggroups it was set up:

set_regset_supply_core_section (arch, ".reg", size, i386_supply_regset);
set_regset_supply_core_section (arch, ".reg2", i386_supply_fpregset);
...
f = regset_supply_from_core_section (core_arch, ".name", length);
f (core_arch, current_regcache, regnum, contents, length);
... or even the short cut ...
regset_supply_core_section (core_arch, ".name", current_regcache, 
regnum, contents, length);

Thoughts?

I just came across this bit of PPC64 GNU/Linux code

> void
> ppc_linux_supply_gregset (char *buf)
> {
>   int regi;
>   struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch); 
> 
>   for (regi = 0; regi < 32; regi++)
>     supply_register (regi, buf + 4 * regi);

(yes, that's a "4" not "8") and was studying the new mechanism.

Andrew