[Simh] fprint_sym and parse_sym limitation

[Paul Koning]

> On Sep 14, 2015, at 12:53 AM, Mark Pizzolato - Info Comm <Mark at infocomm.com> wrote:
> 
> ...
> Paul said:
>> parse_addr and fprint_addr are another area that gave me surprises.  They
>> don't see the switches, so there isn't any way for command switches to
>> affect the address printing, which is what I wanted to be able to do.
> 
> The current command's switches are visible via the global sim_switches.  Accessing this variable is done throughout the codebase.  How doesn't this work for you?

It sounds fine.  I noticed that simh.doc needs to be updated and made more complete, since a bunch of information in it is incorrect, and a bunch of useful things (like this one) are not mentioned.  I'll make a stab at doing some updates and sending the result to this list.  Or is there another way to submit work?

> Paul said:
>> We have a context pointer in
>> the device, but not in the unit (I ended up having to abuse the filebuf for
>> that).  
> 
> Reusing the filebuf could certainly be used for an arbitrary context variable if it isn't being used otherwise.  Alternatively fileref can optionally also not be a FILE *.  When it isn't a FILE *, the unit->dynflags UNIT_NO_FIO flag should be set.  When set, it becomes a unit specific void * which can be used for context or anything else.

Ok.  This is another example of something undocumented.

> Dave's suggestion seems most reasonable due to the zero impact on the existing simulators.  Can you work with that?

It certainly looks that way.  Thanks.

	paul