Re: [PATCH 2/2] Disabling hardware single step in gdbserver

[Andrew Burgess <aburgess@redhat.com>]

Tom Tromey via Gdb-patches <gdb-patches@sourceware.org> writes:

> This patch gives gdbserver the ability to omit the 's' reply to
> 'vCont?'.  This tells gdb that hardware single-step is definitely not
> supported, causing it to fall back to using software single-step.
> This is useful for testing the earlier change to
> maybe_software_singlestep.

LGTM.

Approved-By: Andrew Burgess <aburgess@redhat.com>

Thanks,
Andrew

> ---
>  gdbserver/server.cc | 12 ++++++++----
>  gdbserver/server.h  |  1 +
>  2 files changed, 9 insertions(+), 4 deletions(-)
>
> diff --git a/gdbserver/server.cc b/gdbserver/server.cc
> index c57270175b4..afc18a87770 100644
> --- a/gdbserver/server.cc
> +++ b/gdbserver/server.cc
> @@ -135,6 +135,7 @@ unsigned long signal_pid;
>     in gdbserver, for the sake of testing GDB against stubs that don't
>     support them.  */
>  bool disable_packet_vCont;
> +bool disable_packet_vCont_step;
>  bool disable_packet_Tthread;
>  bool disable_packet_qC;
>  bool disable_packet_qfThreadInfo;
> @@ -3125,9 +3126,10 @@ handle_v_requests (char *own_buf, int packet_len, int *new_packet_len)
>  	{
>  	  strcpy (own_buf, "vCont;c;C;t");
>  
> -	  if (target_supports_hardware_single_step ()
> -	      || target_supports_software_single_step ()
> -	      || !cs.vCont_supported)
> +	  if (!disable_packet_vCont_step
> +	      && (target_supports_hardware_single_step ()
> +		  || target_supports_software_single_step ()
> +		  || !cs.vCont_supported))
>  	    {
>  	      /* If target supports single step either by hardware or by
>  		 software, add actions s and S to the list of supported
> @@ -3456,7 +3458,7 @@ gdbserver_usage (FILE *stream)
>  	   "  --disable-packet=OPT1[,OPT2,...]\n"
>  	   "                        Disable support for RSP packets or features.\n"
>  	   "                          Options:\n"
> -	   "                            vCont, T, Tthread, qC, qfThreadInfo and \n"
> +	   "                            vCont, vConts, T, Tthread, qC, qfThreadInfo and\n"
>  	   "                            threads (disable all threading packets).\n"
>  	   "\n"
>  	   "For more information, consult the GDB manual (available as on-line \n"
> @@ -3766,6 +3768,8 @@ captured_main (int argc, char *argv[])
>  	    {
>  	      if (strcmp ("vCont", tok) == 0)
>  		disable_packet_vCont = true;
> +	      else if (strcmp ("vConts", tok) == 0)
> +		disable_packet_vCont_step = true;
>  	      else if (strcmp ("Tthread", tok) == 0)
>  		disable_packet_Tthread = true;
>  	      else if (strcmp ("qC", tok) == 0)
> diff --git a/gdbserver/server.h b/gdbserver/server.h
> index fde7dfe7060..70fd8ff8b55 100644
> --- a/gdbserver/server.h
> +++ b/gdbserver/server.h
> @@ -68,6 +68,7 @@ void initialize_low ();
>  extern bool server_waiting;
>  
>  extern bool disable_packet_vCont;
> +extern bool disable_packet_vCont_step;
>  extern bool disable_packet_Tthread;
>  extern bool disable_packet_qC;
>  extern bool disable_packet_qfThreadInfo;
>
> -- 
> 2.40.1