Re: [patch v9 23/23] btrace, remote: drop qbtrace packet

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Mon, 04 Mar 2013 18:06:10 +0100, Markus Metzger wrote:
> Use the qXfer:btrace:read packet's annex to encode a trace read method:
> 
>   all ... read all trace
>   new ... read all trace if the trace has changed

BTW fixing previous patches by adding new patches is not right.  It clutters
GDB history.  There will be now target_btrace_has_changed in the history
despite it has never been approved for FSF GDB check-in.

I understand it is easier this way.

But GDB existing in many source variants and people (yes, incl. me) dig into
its history for various backports, regressions finding etc. so a minimal
logical changes are preferred.

Please merge it with the appropriate parts.


> 
> This obsoletes the need for the qbtrace packet.
> 
> CC: Pedro Alves <palves@redhat.com>
> CC: Jan Kratochvil <jan.kratochvil@redhat.com>
> CC: Eli Zaretskii <eliz@gnu.org>
> 
> 2013-03-04  Markus Metzger  <markus.t.metzger@intel.com>
> 
> 	* target.h (target_ops) <to_read_btrace>: Add type parameter.
> 	(target_ops) <to_btrace_has_changed>: Remove.
> 	(target_btrace_has_changed): Remove.
> 	(target_read_btrace): Add type parameter.
> 	* target.c (target_read_btrace): Add type parameter.
> 	(target_btrace_has_changed): Remove.
> 	* remote.c (PACKET_qbtrace): Remove.
> 	(remote_protocol_features): Remove qbtrace.
> 	(remote_supports_btrace): Remove check for qbtrace.
> 	(remote_btrace_has_changed): Remove.
> 	(remote_read_btrace): Consider read type.
> 	(init_remote_ops): Remove to_disable_btrace.
> 	(_initialize_remote): Remove qbtrace.
> 	* i386-linux-nat.c (_initialize_i386_linux_nat): Remove
> 	initialization of to_btrace_has_changed.
> 	* common/linux-btrace.h (linux_read_btrace): Add type parameter.
> 	(linux_btrace_has_changed): Removed.
> 	* common/linux-btrace.c (linux_btrace_has_changed): Moved.
> 	Changed to static.
> 	(linux_read_btrace): Consider read type.
> 	* common/btrace-common.h (btrace_read_type): New enum.
> 	* btrace.c (btrace_fetch): Only update branch trace if it
> 	changed.
> 	* amd64-linux-nat.c (_initialize_amd64_linux_nat): Remove
> 	initialization of to_btrace_has_changed.
> 
> gdbserver/
> 
> 	* target.h (target_ops): Remove btrace_has_changed. Add type
> 	parameter to read_btrace. Update target_ macros.
> 	* server.c: Include btrace-common.h.
> 	(handle_qxfer_btrace): Consider read type in annex.
> 	(handle_btrace_query): Removed.
> 	(handle_query): Remove qbtrace from qSupported. Remove call to
> 	handle_btrace_query.
> 	* linux-low.c (linux_low_read_btrace): Consider read type.
> 	(linux_target_ops): Remove linux_btrace_has_changed.
> 
> doc/
> 
> 	* gdb.texinfo (Remote Configuration): Remove qbtrace.
> 	Describe annex of Qbtrace.
[...]
> --- a/gdb/remote.c
> +++ b/gdb/remote.c
[...]
>  /* Read the branch trace.  */
>  
>  static VEC (btrace_block_s) *
> -remote_read_btrace (struct btrace_target_info *tinfo)
> +remote_read_btrace (struct btrace_target_info *tinfo,
> +		    enum btrace_read_type type)
>  {
>    struct packet_config *packet = &remote_protocol_packets[PACKET_qXfer_btrace];
>    struct remote_state *rs = get_remote_state ();
>    VEC (btrace_block_s) *btrace = NULL;
> +  const char *annex;
>    char *xml;
>  
>    if (packet->support != PACKET_ENABLE)
> @@ -11268,8 +11223,21 @@ remote_read_btrace (struct btrace_target_info *tinfo)
>    error (_("Cannot process branch tracing result. XML parsing not supported."));
>  #endif
>  
> +  switch (type)
> +    {
> +    case btrace_read_all:
> +      annex = "all";
> +      break;
> +    case btrace_read_new:
> +      annex = "new";
> +      break;
> +    default:

Here should be internal_error call.  It just cannot happen in valid GDB
binary.


> +      annex = NULL;
> +      break;
> +    }
> +
>    xml = target_read_stralloc (&current_target,
> -                              TARGET_OBJECT_BTRACE, NULL);
> +                              TARGET_OBJECT_BTRACE, annex);
>    if (xml != NULL)
>      {
>        struct cleanup *cleanup = make_cleanup (xfree, xml);