[Valgrind-developers] Rearranging the tree

[Jeremy F. <je...@go...>]

I've been thinking about how to rearrange the source tree to handle
multiple OS and CPU combinations.  I'm basing my thinking from looking
at Doug's FreeBSD port, and Dirk's initial cut at an arch/ directory.

It looks to me that there's a lot more in common between FreeBSD and
Linux than I would have hoped for; almost all of vg_syscalls and
vg_signals is intact, and vg_libpthread is mostly just syntactic changes
rather than anything of substance.  It would be really nice to put all
that common stuff into a common place, to try and cut down on
duplication.  I'd also like to minimise #ifdefs in shared code.

To this end, I think we'll need a number of arch directories:
	i386-linux	machine-specific linux stuff
	i386-freebsd	machine-specific freebsd stuff
	common-linux	general linux stuff
	common-freebsd	general freebsd stuff
	i386-common	OS-independent i386 stuff
	common-unix	things common to Unix-like systems

(I decided to go with CPU names like autoconf/uname -i uses)

So far, i386-linux/freebsd has things like vg_syscall.S, and the various
very machine-dependent parts of ume.  Later it will get things like the
details of how to get/set syscall args for vg_syscalls.c, signal
restart, etc.  Also syscall numbering, and CPU-specific syscalls (LDT
stuff, etc).

common-linux/freebsd will probably get most of the rest of vg_signals
where they differ, and probably most of the OS-specific parts of
vg_syscalls.c

i386-common will ultimately get most of vg_to/from_ucode.c.

common-unix will get all the really generic syscall handling (things
like read/write/exit/fork/exec, etc).

I'm attaching my patch-in-progress.  This is all still an experiment, so
if it doesn't work out, I'm happy to throw it away.  But I'd like to get
something like this in place as I merge the FreeBSD port (or before, and
merge FreeBSD into it).

Comments?  Thoughts?

BTW: I put some stuff in the Makefile.am files which doesn't look good,
and surely can't be right - there seems to be a lot of duplication.  How
can I fix this?  Maybe something to do with aclocal?

	J