From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cagney <ac131313@cygnus.com>
To: GDB Discussion <gdb@sources.redhat.com>
Subject: Re: A better register interface
Date: Fri, 16 Feb 2001 06:48:00 -0000
Message-id: <3A8D3CB1.56F453BA@cygnus.com>
References: <004a01c097b1$d149bc90$05d145cc@ppro> <3A8C8D34.A33813EE@cygnus.com>
X-SW-Source: 2001-02/msg00210.html

Andrew Cagney wrote:

> It would consist of roughly:
> 
>         core-gdb
>             \
>           cooked-regs   your-target
>               \         /
>              raw-regs-buffer

Actually, try this:

            context
             /    \  .----.
            /      \ |    |
           /      frame---'
          /       /   \
   continuation  /     \
        |       /       \
        |      /         \
        |   memcache   regcache
        |      |           |
..........................................
        |      |           |
   targ-run  targ-mem  targ-regs

Where:

context:
The execution thing that the user likes to manipulate. In the simple
case it represents a UNIX process with memory, stack and registers.

continuation:
The per context start/stop state.  It keeps track of what the user/GDB
is trying to do to a context while the context is running.

frame:
Frames make up more than just the context stack.  When moving between
frames, anything could change - the address space, registers,
architecture, target.  GDB already tries to handle (badly) targets that
have architecture changes between frames.

memcache:
gdb's representation a target's memory address space.

regcache:
gdb's representation of a target's registers.

	enjoy,
		Andrew