Re: Discrepency between gdbarch_frame_locals_address and get_frame_locals_address?

[Andrew Cagney <ac131313 at redhat dot com>]

> Andrew,
>
> Whilst poking around on related things, I observed that, at least on
> Linux,

Um, which GNU/Linux, which architecture, and how recent a GDB?  Lets 
assume i386 and gdb_6_0-branch.

> the values of gdbarch_frame_locals_address and
> get_frame_locals_address disagree.  The latter appears to be correct,
> since it is used in read_var_value in what I assume is the intended
> way (add SYMBOL_VALUE to get_frame_locals_address (frame) to get
> variable address).

Yes.  get_frame_locals_address returns what debug info thinks of as the 
frame base.  Local variables being specified as offsets from that 
address.  Just don't confuse it with gdb's [deprecated] get_frame_base :-(

> Would you like a patch, or is there a subtle
> point here that I am missing?

There is likely a subtle point^D^D^Dproblem vis:  The backward 
compatible path is
	get_frame_locals_address
	-> [deprecated] gdbarch_frame_locals_address
	-> get_frame_base
	-> get_frame_id.stack_addr
and, so pre-frame code has identical values for both.  New code, 
however, has a different frame ID .stack_addr and frame-locals-address.

You've probably found code using the wrong one.

Andrew