Re: Harvard proposal

[Andrew Cagney <ac131313@cygnus.com>]

Per Bothner wrote:
> 
> Andrew Cagney <ac131313@cygnus.com> writes:
> 
> > A CORE_ADDR is a cannonical address within the target address space.  A
> > CORE_ADDR should, in theory, be able to identify every target byte (or
> > if someone gets it working - word).
> 
> To clarify: By "target address space" do you mean the combined address
> spaces of all the targets put together, or the address space of any
> single target?  In other words, should a CORE_ADDR would also provide
> some way of identifying a specific sub-space (i.e. specific target)?
> Or should sub-space identification (which subsumes process id and host
> network address) be something *separate* from the CORE_ADDR?

In Chorus an ``actor''s address space; in UNIX, a single processes
memory space; on an SMP machine the address space visible to a single
CPU.

GDB currently doesn't understand the concept of multiple, separate
addresses spaces (as would be seen when debugging two separate UNIX
processes).

> > However, as with traditional C, I'd suggest following the convention of
> > CORE_ADDR (void*) for pointers and LONGEST (long) for offsets.
> 
> Again to clarify:  We're talking *target* void*, represented as an
> integer type in gdb, not a pointer type.

A C programmer would be accustomed to code using ``void*'' for a generic
address and ``long'' for a generic offset.  In a similar way, a GDB
developer would be accustomed to using CORE_ADDR when manipulating a
generic target address and (in theory) LONGEST when manipulating a
generic target offset.

	Andrew