[PATCH/i386newframe/RFC] DWARF CFI frame unwinder

[Andrew Cagney]

Mark, fyi,

> +    case REG_SAVED_REG:
> +      *optimizedp = 0;
> +      *lvalp = lval_register;
> +      *addrp = 0;
> +      *realnump = DWARF2_REG_TO_REGNUM (cache->reg[regnum].loc.reg);
> +      if (valuep)
> +	{
> +	  /* Read the value from the register.  */
> +	  frame_unwind_register (next_frame, *realnump, valuep);
> +	}
> +      break;
> +

Set *addrp to the register offset hack (Otherwize something mysterious 
fails.  What? I don't remember).

Using the frame obstack for memory looks right.

> +static CORE_ADDR
> +dwarf_frame_base_address (struct frame_info *next_frame, void **this_cache)
> +{
> +  struct dwarf_frame_cache *cache = dwarf_frame_cache (next_frame, this_cache);
> +
> +  return cache->cfa;
> +}

This isn't right.  It should return DW_AT_frame_base.  However, since 
dwarf2expr.c doesn't yet use these methods it doesn't [?] really matter. 
  Only affects ``info frame''.

I suspect things like execute_stack_op might need more cleanups.  A dead 
target, or bad memory read, can throw an error.

Looks like the interface works (and oh so much cleaner than the old 
code) :-)

Andrew