Re: gdbserver target description: info reg displays or not according to group presence ???

["Philippe Waroquiers" <philippe dot waroquiers at skynet dot be>]

On Sun, 1 Aug 2010 22:39:47 -0400, Daniel Jacobowitz wrote:
> Separately, note "must be".  Don't use group="s1".  Target-defined
> register groups aren't supported.

In target-description.c, I found the following comment:
  Arbitrary strings (other than "general", "float", and "vector")
  from the description are not used; they cause the register to be
  displayed in "info all-registers" but excluded from "info
  registers" et al.  The names of containing features are also not
  used.  This might be extended to display registers in some more
  useful groupings.

I guess the idea is that one day, something like
   info registers a_target_defined_abitrary_group
will show the registers of this group.

So, it looks like the code currently already accepts arbitrary
register group but that the doc about GROUP does not mention this.


> Yes, it looks like a bug in i386_register_reggroup_p, in the last bit
> (group == general_reggroup_p).  One way to fix it would be to add a
> range check (&& regnum < I386_NUM_GREGS).

Not too sure of what I did but a small test seems ok with the below code:
 if (group == general_reggroup)
   return (!fp_regnum_p
    && !mmx_regnum_p
    && !mxcsr_regnum_p
    && !xmm_regnum_p
    && !ymm_regnum_p
    && !ymmh_regnum_p
           && regnum < I386_NUM_GREGS);
Note that the tests above seems redundant: none of the registers 
below I386_NUM_GREGS are fp or mmx or ...


Should I do a bug entry for this and also for clarifying the doc/comment ?

The documentation of GROUP could probably be clarified and/or the comment
in the code could be changed :
  * the code accepts any string as group name, doc does not mention this.
  * also the target xml files for i386 does not specify any
    group for e.g. eax, but eax is shown in info registers.
    I imagine we need an additional sentence such as 
      "Pre-defined standard registers have an hard-coded set of groups. 
       Use 'maint print register-groups' to look at these. The standard
       registers belonging to general group will be shown by 
       'info registers'."


Philippe