Re: [PATCH 3/6] Use std::vector<bool> for agent_expr::reg_mask

[John Baldwin <jhb@FreeBSD.org>]

On 6/19/23 2:06 PM, Tom Tromey wrote:
> agent_expr::reg_mask implements its own packed boolean vector.  This
> patch replaces it with a std::vector<bool>, simplifying the code.
> ---
>   gdb/ax-general.c | 30 ++++++------------------------
>   gdb/ax.h         | 15 +++++----------
>   gdb/tracepoint.c | 16 +++++-----------
>   3 files changed, 16 insertions(+), 45 deletions(-)
> 
> diff --git a/gdb/ax-general.c b/gdb/ax-general.c
> index d5f4c51e65d..89e297eddc6 100644
> --- a/gdb/ax-general.c
> +++ b/gdb/ax-general.c
> @@ -330,8 +325,9 @@ ax_print (struct ui_file *f, struct agent_expr *x)
>   
>     gdb_printf (f, _("Scope: %s\n"), paddress (x->gdbarch, x->scope));
>     gdb_printf (f, _("Reg mask:"));
> -  for (i = 0; i < x->reg_mask_len; ++i)
> -    gdb_printf (f, _(" %02x"), x->reg_mask[i]);
> +  for (i = 0; i < x->reg_mask.size (); ++i)
> +    if (x->reg_mask[i])
> +      gdb_printf (f, _(" %02x"), i);
>     gdb_printf (f, _("\n"));

This was previously printing the bytes of the raw bitmask so that the mask was
printed in packed hex.  Now it is printing each bit as a 2 character hex value
(so you now end up with 01 01 00 00 00 01 00 00 instead of c4 for example).
Re-synthesizing the packed hex output may not be useful, but perhaps you could
print it as binary instead by only printing 0 or 1 for each bit without spaces
(or maybe only spaces between each 8 bits?).  Something like:

    for (i = 0; i < x->reg_mask.size (); ++i)
      {
        if (i % 8 == 0)
          gdb_printf(f, _(" "));
        gdb_printf (f, _("%u"), x->reg_mask[i]);
      }

-- 
John Baldwin