Add CRIS -sim* option from specs to cris/elf.opt

[Hans-Peter Nilsson]

> Date: Tue, 8 Feb 2011 23:42:03 +0000 (UTC)
> From: "Joseph S. Myers" <joseph@codesourcery.com>

> In preparation for the driver only accepting options listed in .opt
> files, and not other options that simply happen to match some spec,
> this patch adds the -sim* option from specs in cris/cris.h to
> cris/elf.opt (the targets for which those specs are active are exactly
> those using cris/elf.opt; cris-linux does not use these specs).

Correct, as you most likely understood this is used for
cross-testing with a simulator.  For "cris-linux" -static is
used; the src/sim simulator uses the Linux syscall ABI, for the
implemented subset.

> Tested building cc1 and xgcc for cross to cris-elf.  Committed.  Note
> that while the option description here matches that in the specs, I
> don't know if it accurately describes the set of options intended to
> be accepted.

Just currently either of "-sim", "-sim2", "-sim3"; very ad-hoc.
(You don't see the latter in config/cris/cris.h, it's passed by
the dejagnu cris-sim board.)  It's intended to control which
library and start/endfiles are used; a few variants and
memory-mappings.  FWIW, I no longer remember why I didn't
originally use the -m* namespace, then it stuck.

>  There is one spec matching -sim2, and others matching
> -sim*, meaning that all -sim* options are accepted, but the only
> distinction is between -sim2 and other -sim* options.  So CRIS
> maintainers may wish to refine the option description in the .opt file
> to reflect the actual intended set of options.

Right, and the intention was to leave it open, right or wrong. :)

> 2011-02-08  Joseph Myers  <joseph@codesourcery.com>
> 
> 	* config/cris/elf.opt (sim): New Driver option.

Ok, thanks!

brgds, H-P