Linker relaxation

[Stephane Carrez <Stephane dot Carrez at worldnet dot fr>]

Hi!

I would like to implement linker relaxation for some instructions of
68HC11/68HC12. I remember there was some discussions about that for m68K
(in April 17th, 2000), and I have some questions:

 o Existing targets are using specific relocations (.rel or .rela)
   to specify the relaxation points.  Some time ago there was a discussion
   that it would be more appropriate to use a specific section to
   store those relaxation information.

   So, what is the recommended way to store the relaxation relocs?

   (As far as I'm concerned, using relocs is easier, but well, I don't care)

 o If a specific section is dedicated to that, would it make sense to
   also take into account the GNU_VTINHERIT/VTENTRY within it?

 o Now, the hard question about gas -gdwarf2....

   Suppose you have an instruction that is linker-relaxable, and that
   you assembled the source with -gdwarf2.  In that case, Gas generated
   .debug_* sections that gives debugging info, and in particular the
   size of that insn.  If that instruction is shrunk, how can the debugging
   information be fixed?

   My understanding of gas/dwarf2dbg.c is that nothing is there to emit
   a relaxation info for an instruction that can be linker-relaxable.
   The difference with the instruction-relaxation is that the fix/correction
   must be made in the .debug_line.

Thanks,
  Stephane

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