From mboxrd@z Thu Jan  1 00:00:00 1970
From: Andrew Cagney <ac131313@cygnus.com>
To: GDB Discussion <gdb@sources.redhat.com>
Subject: nm.h, *-nat.c and multi-arch?
Date: Wed, 04 Jul 2001 09:12:00 -0000
Message-id: <3B43404E.6090805@cygnus.com>
X-SW-Source: 2001-07/msg00024.html

Hello,

I'm trying to eliminate xm.h, tm.h and possibly nm.h.  Part of that is 
actually understanding what should and what should not be in a nm.h and 
*-nat.c.

xm.h is pretty easy, it can be replaced by autoconf magic.  As they say, 
It is now ``done stage 7 - it was seen to work once'' (cf NetBSD/PPC).

tm.h is also straight forward.  It has been replaced by the gdbarch 
vector (gdbarch.h/c) and extra *-tdep.c code.

nm.h and *-nat.c, however are more interesting.  Studying the code I 
think it has been used for:

	o	interface code to make
		procfs, ptrace, ... work

		See below.

	o	Stuff that should have
		been put in the xm file.

		I'll pretend this didn't
		happen :-)

	o	Stuff that should have been
		put in a tm file.

		Ditto :-)

	o	OS specific info for
		standard features (core file,
		shared libraries, ...).

		This is now also being moved to gdbarch
		and being made host independant.  It
		is definitly a WIP though.

		See wart below.

	o	customize to enable
		extra (OS/arch specific?) features.
		(The i386 hw breakpoint code
		comes to mind.)

		Here again, I think this should really
		be host independant.

		See wart below.

Ignoring the warts, this just leaves the the first case.  As best as I 
can tell, the only things that, strictly speaking, should be in nm.h and 
*-nat.c are macros/functions that enable the native interface code 
(procfs, ptrace, ...).  Having an nm.h for those files is probably ok 
since procfs.[hc] is HOST=TARGET specific.

Anyway, this in turn begs the (for the moment largely accademic) 
question should procfs.c et.al. include nm.h directly instead of having 
defs.h include it.

--

The wart?  So far multi-arch has concentrated on problems like:

	MIPS2 embedded
	MIPS3 embedded

but has avoided cases such as:

	Linux/MIPS native and remote
	MIPS embedded
	*BSD/MIPS remote

i.e. OS as well as ISA/ABI as a variant.  For nm.h to be reduced to just 
_native_ interface support, multi-arch will need to be extended to 
include this.

	Andrew