Re: [RFA] findvar.c: support LOC_BASEREG[_ARG] on Harvard archs

[Jim Blandy <jimb at zwingli dot cygnus dot com>]

Andrew Cagney <ac131313@cygnus.com> writes:
> > Index: gdb/findvar.c
> > ===================================================================
> > diff -up gdb/findvar.c gdb/findvar.c> --- gdb/findvar.c	Mon Jul 16 12:41:21 2001
> > +++ gdb/findvar.c	Mon Jul 16 12:39:40 2001
> > @@ -612,9 +612,10 @@ addresses have not been bound by the dyn
> >      case LOC_BASEREG_ARG:
> >        {
> >  	char *buf = (char*) alloca (MAX_REGISTER_RAW_SIZE);
> > +	memset (buf, 0, MAX_REGISTER_RAW_SIZE);
> >  	get_saved_register (buf, NULL, NULL, frame, SYMBOL_BASEREG (var),
> >  			    NULL);
> > -	addr = extract_address (buf, REGISTER_RAW_SIZE (SYMBOL_BASEREG (var)));
> > +	addr = POINTER_TO_ADDRESS (builtin_type_void_data_ptr, buf);
> >  	addr += SYMBOL_VALUE (var);
> >  	break;
> 
> 
> FYI, I think this change will break the MIPS o64 ABI in big-endian mode.
> Under that ABI, 8 byte registers are used (and saved on the stack) but 
> sizeof (void*) == 4.  If I'm reading the above change correctly, 
> pointer_to_address() will always extract the value from the first 4 
> bytes of of the register when, for o64/BE, it should be using the second 
> 4 bytes.

That's right, it will.  :(

Probably using register_value and value_as_pointer is best, then.