On Monday 30 May 2005 20:58, Daniel Jacobowitz wrote:
> On Mon, May 30, 2005 at 06:22:19PM +0400, Vladimir Prus wrote:
> > Hello,
> > I'm working on a gdb port, and have problems with printing certain
> > registers of my target. The problem is that those registers are vector
> > buffers that can hold from 0 to 32 values at any given moment. I would
> > like the 'info registers' command to print exactly the number of values
> > that are present in a buffer. That is, on one invocation I might get 4
> > values printed, and on another 15, depending on the current processor
> > state.
> >
> > However, I don't see an easy way to do this. The
> > 'default_print_registers_info' function uses 'val_print' to print the
> > value, and 'val_print' uses register type (struct type*), which has a
> > fixed size. Anything I can do? Or I should just write arch-specific
> > 'print_registers_info' function?
>
> The last one.  The best you can do the rest of the time is going to be
> giving them a type containing the maximum number of values and fill in
> with dummies - maybe also including the count?

This's what I was doing -- assigning "array of 32 uin64s" type to those 
registers and they are printed with "info all-registers", but the dummy
values do no look nice when presented to the user.

> If you want "print $reg" to display them nicely, you're going to need
> to teach GDB's type system about it somehow.  I have no idea what that
> change would look like or how it would work, but it could be generally
> useful - it's the same concept as prettyprinting a tagged union, I think.

Ok, understood. With the attached patch I get what I want, but I have no idea 
if this patch is good or not.

- Volodya