RFC: DWARF2 support for VAX ELF.

[Richard Henderson]

On Mon, Jun 10, 2002 at 11:46:38PM -0700, Matt Thomas wrote:
> But DWARF2 seems to want to use SP whereas use of FP is more natural on a
> VAX.  Note that all stack based variables are referenced off of FP
> rather than SP.

Add an INCOMING_FRAME_CFA_REGNUM and default it to the stack pointer.

Rename INCOMING_FRAME_SP_OFFSET to INCOMING_FRAME_CFA_REG_OFFSET for
consistency.  There aren't many uses.  Delete the three definitions
that are the default 0.  Move the defaults to, gasp, defaults.h.

> Again, my next problem is DWARF2's insistence of using SP.  I want to
> define EH_RETURN_HANDLER_RTX as INCOMING_RETURN_ADDR_RTX but that defined
> in terms of FP which initial_return_save find's objectionable (it aborts
> if the REG is not the SP).
> 
> Along the same lines, I'd to define EH_RETURN_STACKADJ_RTX as "-4(%fp)"
> but again DWARF2 wants it to be SP based.

Have them abort if the reg isn't INCOMING_FRAME_CFA_REGNUM.


r~