Re: [RFA] block_innermost_frame tweak

Jim Blandy
2002-06-21T19:14:25Z

Andrew Cagney <ac131313@cygnus.com> writes:
> Is there a better name? As you note, it isn't a valid PC (it may not
> even point into an instruction!). Further, it is isn't the address of
> the instruction ``calling'' the ``frame''. Last time this came up
> address_in_block() was used - frame_address_in_block()?

I don't disagree with your objections (raised in a previous
discussion) that `frame->pc - 1' isn't a proper PC. It may never have
been the value of the PC register (if indeed the architecture has a
register named `PC'); it doesn't even necessarily point to an
instruction.

That said, I feel that replacing "PC" with just "address" actually
makes matters worse, not better. It's very helpful to see at a glance
that a particular CORE_ADDR value is a pointer into the instruction
stream. The exact semantics of the value --- is this the return
address or the address of the call? do we need to apply
DECR_PC_AFTER_BREAK? and so on --- is something that one uncovers
when one researches the value more carefully, as with anything else.

But if I'm the only one who has this reaction, then I don't mind the
renaming.

Is there some third terse term that indicates (or could indicate, by
establishing a convention) "pointer into the instruction stream that
isn't necessarily an instruction address or the value of a register"?