Add method/format information to =record-started

Message ID 20160603155220.22286-1-simon.marchi@ericsson.com
State New, archived
Headers

Commit Message

Simon Marchi June 3, 2016, 3:52 p.m. UTC
  Eclipse CDT now supports enabling execution recording using two methods
(full and btrace) and both formats for btrace (bts and pt).  In the
event that recording is enabled behind the back of the GUI (by the user
on the command line, or a script), we need to know which method/format
are being used, so it can be correctly reflected in the interface.  This
patch adds this information to the =record-started async record.

Before:

  =record-started,thread-group="i1"

After:

  =record-started,thread-group="i1",method="btrace",format="bts"
  =record-started,thread-group="i1",method="btrace",format="pt"
  =record-started,thread-group="i1",method="full"

The "format" field is only present when the current method supports
multiple formats (only the btrace method as of now).

gdb/ChangeLog:

	* NEWS: Mention the new fields in =record-started.
	* mi/mi-interp.c (mi_record_changed): Output method and format
	fields in the =record-started record.
	* record-btrace.c (record_btrace_open): Adapt record_changed
	notification.
	* record-full.c (record_full_open): Likewise.
	* record.c (cmd_record_stop): Likewise.

gdb/doc/ChangeLog:

	* gdb.texinfo (GDB/MI Async Records): Document method and
	format fields in =record-started.
	* observer.texi (record_changed): Add method and format
	parameters.

gdb/testsuite/ChangeLog:

	* gdb.mi/mi-record-changed.exp: Adjust =record-started output
	matching.
---
 gdb/NEWS                                   |  5 +++++
 gdb/doc/gdb.texinfo                        |  7 ++++++-
 gdb/doc/observer.texi                      |  7 ++++++-
 gdb/mi/mi-interp.c                         | 32 ++++++++++++++++++++++++++----
 gdb/record-btrace.c                        |  4 +++-
 gdb/record-full.c                          |  2 +-
 gdb/record.c                               |  2 +-
 gdb/testsuite/gdb.mi/mi-record-changed.exp |  4 ++--
 8 files changed, 52 insertions(+), 11 deletions(-)
  

Comments

Simon Marchi June 3, 2016, 5:03 p.m. UTC | #1
On 16-06-03 11:52 AM, Simon Marchi wrote:
> diff --git a/gdb/NEWS b/gdb/NEWS
> index dce79a2..5d59bc7 100644
> --- a/gdb/NEWS
> +++ b/gdb/NEWS
> @@ -67,6 +67,11 @@ maint selftest
>    including JIT compiling fast tracepoint's conditional expression
>    bytecode into native code.
>  
> +* MI async record =record-started new includes the method and format used for

Oops, typo here.  new -> now.
  
Metzger, Markus T June 6, 2016, 6:37 a.m. UTC | #2
> -----Original Message-----
> From: gdb-patches-owner@sourceware.org [mailto:gdb-patches-
> owner@sourceware.org] On Behalf Of Simon Marchi
> Sent: Friday, June 3, 2016 5:52 PM
> To: gdb-patches@sourceware.org
> Cc: Simon Marchi <simon.marchi@ericsson.com>
> Subject: [PATCH] Add method/format information to =record-started
> 
> Eclipse CDT now supports enabling execution recording using two methods
> (full and btrace) and both formats for btrace (bts and pt).  In the
> event that recording is enabled behind the back of the GUI (by the user
> on the command line, or a script), we need to know which method/format
> are being used, so it can be correctly reflected in the interface.  This
> patch adds this information to the =record-started async record.
> 
> Before:
> 
>   =record-started,thread-group="i1"
> 
> After:
> 
>   =record-started,thread-group="i1",method="btrace",format="bts"
>   =record-started,thread-group="i1",method="btrace",format="pt"
>   =record-started,thread-group="i1",method="full"
> 
> The "format" field is only present when the current method supports
> multiple formats (only the btrace method as of now).

Thanks for adding this.


> @@ -407,8 +409,30 @@ mi_record_changed (struct inferior *inferior, int started)
>    old_chain = make_cleanup_restore_target_terminal ();
>    target_terminal_ours_for_output ();
> 
> -  fprintf_unfiltered (mi->event_channel,  "record-%s,thread-group=\"i%d\"",
> -		      started ? "started" : "stopped", inferior->num);
> +  if (started)
> +    {
> +      if (format != NULL)
> +	{

Do we really need braces, here...

> +	  fprintf_unfiltered (
> +	    mi->event_channel,
> +	    "record-started,thread-
> group=\"i%d\",method=\"%s\",format=\"%s\"",
> +	    inferior->num, method, format);
> +	}
> +      else
> +	{
> +

...and here...

> +	  fprintf_unfiltered (
> +	    mi->event_channel,
> +	    "record-started,thread-group=\"i%d\",method=\"%s\"",
> +	    inferior->num, method);
> +	}
> +    }
> +  else
> +    {

...and here?

> +      fprintf_unfiltered (mi->event_channel,
> +			  "record-stopped,thread-group=\"i%d\"", inferior-
> >num);
> +    }
> +


> @@ -234,7 +235,8 @@ record_btrace_open (const char *args, int from_tty)
>  				  NULL);
>    record_btrace_generating_corefile = 0;
> 
> -  observer_notify_record_changed (current_inferior (),  1);
> +  format = record_btrace_conf.format == BTRACE_FORMAT_PT ? "pt" : "bts";

I'd use a switch here and not assume that format != pt means bts.  If we added
another format (LBR maybe?) we might miss this.


Regards,
Markus.

Intel Deutschland GmbH
Registered Address: Am Campeon 10-12, 85579 Neubiberg, Germany
Tel: +49 89 99 8853-0, www.intel.de
Managing Directors: Christin Eisenschmid, Christian Lamprechter
Chairperson of the Supervisory Board: Nicole Lau
Registered Office: Munich
Commercial Register: Amtsgericht Muenchen HRB 186928
  
Yao Qi June 6, 2016, 1:03 p.m. UTC | #3
"Metzger, Markus T" <markus.t.metzger@intel.com> writes:

Hi Markus,
Thanks for reviewing the patch....

>> +      if (format != NULL)
>> +	{
>
> Do we really need braces, here...
>

Yes, two or more lines in code should be wrapped in braces.
https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards

>> @@ -234,7 +235,8 @@ record_btrace_open (const char *args, int from_tty)
>>  				  NULL);
>>    record_btrace_generating_corefile = 0;
>> 
>> -  observer_notify_record_changed (current_inferior (),  1);
>> +  format = record_btrace_conf.format == BTRACE_FORMAT_PT ? "pt" : "bts";
>
> I'd use a switch here and not assume that format != pt means bts.  If we added
> another format (LBR maybe?) we might miss this.

I agree, otherwise, the patch is good to me.
  
Simon Marchi June 6, 2016, 1:24 p.m. UTC | #4
On 16-06-06 09:03 AM, Yao Qi wrote:
> "Metzger, Markus T" <markus.t.metzger@intel.com> writes:
> 
> Hi Markus,
> Thanks for reviewing the patch....
> 
>>> +      if (format != NULL)
>>> +	{
>>
>> Do we really need braces, here...
>>
> 
> Yes, two or more lines in code should be wrapped in braces.
> https://sourceware.org/gdb/wiki/Internals%20GDB-C-Coding-Standards

Just to be clear, the inner if/else doesn't need them, but the outer one does.

Here's the result:


  if (started)
    {
      if (format != NULL)
	fprintf_unfiltered (
	  mi->event_channel,
	  "record-started,thread-group=\"i%d\",method=\"%s\",format=\"%s\"",
	  inferior->num, method, format);
      else
	fprintf_unfiltered (
	  mi->event_channel,
	  "record-started,thread-group=\"i%d\",method=\"%s\"",
	  inferior->num, method);
    }
  else
    fprintf_unfiltered (mi->event_channel,
			"record-stopped,thread-group=\"i%d\"", inferior->num);
  
Yao Qi June 7, 2016, 9:32 a.m. UTC | #5
Simon Marchi <simon.marchi@ericsson.com> writes:

> Just to be clear, the inner if/else doesn't need them, but the outer one does.
>

No, it is not "GDB C Coding Standard" compliant, IMO.  In the quoted url
I gave,

"Any two or more lines in code should be wrapped in braces, even if they
are comments, as they look like separate statements:"

so...

> Here's the result:
>
>
>   if (started)
>     {
>       if (format != NULL)

brace is needed here...

> 	fprintf_unfiltered (
> 	  mi->event_channel,
> 	  "record-started,thread-group=\"i%d\",method=\"%s\",format=\"%s\"",
> 	  inferior->num, method, format);

and here

>       else
> 	fprintf_unfiltered (
> 	  mi->event_channel,
> 	  "record-started,thread-group=\"i%d\",method=\"%s\"",
> 	  inferior->num, method);
>     }
>   else
>     fprintf_unfiltered (mi->event_channel,
> 			"record-stopped,thread-group=\"i%d\"", inferior->num);
  
Simon Marchi June 7, 2016, 12:53 p.m. UTC | #6
On 16-06-07 05:32 AM, Yao Qi wrote:
> Simon Marchi <simon.marchi@ericsson.com> writes:
> 
>> Just to be clear, the inner if/else doesn't need them, but the outer one does.
>>
> 
> No, it is not "GDB C Coding Standard" compliant, IMO.  In the quoted url
> I gave,
> 
> "Any two or more lines in code should be wrapped in braces, even if they
> are comments, as they look like separate statements:"

Ahh ok, I thought braces were only needed in the case where you added a comment.

> so...
> 
>> Here's the result:
>>
>>
>>   if (started)
>>     {
>>       if (format != NULL)
> 
> brace is needed here...
> 
>> 	fprintf_unfiltered (
>> 	  mi->event_channel,
>> 	  "record-started,thread-group=\"i%d\",method=\"%s\",format=\"%s\"",
>> 	  inferior->num, method, format);
> 
> and here
> 
>>       else
>> 	fprintf_unfiltered (
>> 	  mi->event_channel,
>> 	  "record-started,thread-group=\"i%d\",method=\"%s\"",
>> 	  inferior->num, method);
>>     }
>>   else
>>     fprintf_unfiltered (mi->event_channel,
>> 			"record-stopped,thread-group=\"i%d\"", inferior->num);

I suppose here too?
  
Yao Qi June 7, 2016, 3:38 p.m. UTC | #7
Simon Marchi <simon.marchi@ericsson.com> writes:

>>>   else
>>>     fprintf_unfiltered (mi->event_channel,
>>> 			"record-stopped,thread-group=\"i%d\"", inferior->num);
>
> I suppose here too?

Yes, I think so.
  

Patch

diff --git a/gdb/NEWS b/gdb/NEWS
index dce79a2..5d59bc7 100644
--- a/gdb/NEWS
+++ b/gdb/NEWS
@@ -67,6 +67,11 @@  maint selftest
   including JIT compiling fast tracepoint's conditional expression
   bytecode into native code.
 
+* MI async record =record-started new includes the method and format used for
+  recording.  For example:
+
+    =record-started,thread-group="i1",method="btrace",format="bts"
+
 *** Changes in GDB 7.11
 
 * GDB now supports debugging kernel-based threads on FreeBSD.
diff --git a/gdb/doc/gdb.texinfo b/gdb/doc/gdb.texinfo
index 7e89003..5739d05 100644
--- a/gdb/doc/gdb.texinfo
+++ b/gdb/doc/gdb.texinfo
@@ -26423,12 +26423,17 @@  breakpoint commands; @xref{GDB/MI Breakpoint Commands}.  The
 Note that if a breakpoint is emitted in the result record of a
 command, then it will not also be emitted in an async record.
 
-@item =record-started,thread-group="@var{id}"
+@item =record-started,thread-group="@var{id}",method="@var{method}"[,format="@var{format}"]
 @itemx =record-stopped,thread-group="@var{id}"
 Execution log recording was either started or stopped on an
 inferior.  The @var{id} is the @value{GDBN} identifier of the thread
 group corresponding to the affected inferior.
 
+The @var{method} field contains the method used to record execution.  If the
+method in use supports multiple recording formats, @var{format} will be present
+and contain the currently used format.  See @xref{Process Record and Replay}
+for existing method and format values.
+
 @item =cmd-param-changed,param=@var{param},value=@var{value}
 Reports that a parameter of the command @code{set @var{param}} is
 changed to @var{value}.  In the multi-word @code{set} command,
diff --git a/gdb/doc/observer.texi b/gdb/doc/observer.texi
index f4049ad..fc7aac4 100644
--- a/gdb/doc/observer.texi
+++ b/gdb/doc/observer.texi
@@ -141,11 +141,16 @@  at the entry-point instruction.  For @samp{attach} and @samp{core},
 inferior, and before any information on the inferior has been printed.
 @end deftypefun
 
-@deftypefun void record_changed (struct inferior *@var{inferior}, int @var{started})
+@deftypefun void record_changed (struct inferior *@var{inferior}, int @var{started}, const char *@var{method}, const char *@var{format})
 The status of process record for inferior @var{inferior} in
 @value{GDBN} has changed.  The process record is started if
 @var{started} is true, and the process record is stopped if
 @var{started} is false.
+
+When @var{started} is true, @var{method} indicates the short name of the method
+used for recording.  If the method supports multiple formats, @var{format}
+indicates which one is being used, otherwise it is NULL.  When @var{started} is
+false, they are both NULL.
 @end deftypefun
 
 @deftypefun void solib_loaded (struct so_list *@var{solib})
diff --git a/gdb/mi/mi-interp.c b/gdb/mi/mi-interp.c
index 0fe19af..09de9fe 100644
--- a/gdb/mi/mi-interp.c
+++ b/gdb/mi/mi-interp.c
@@ -65,7 +65,8 @@  static void mi_on_no_history (void);
 
 static void mi_new_thread (struct thread_info *t);
 static void mi_thread_exit (struct thread_info *t, int silent);
-static void mi_record_changed (struct inferior*, int);
+static void mi_record_changed (struct inferior*, int, const char *,
+			       const char *);
 static void mi_inferior_added (struct inferior *inf);
 static void mi_inferior_appeared (struct inferior *inf);
 static void mi_inferior_exit (struct inferior *inf);
@@ -399,7 +400,8 @@  mi_thread_exit (struct thread_info *t, int silent)
 /* Emit notification on changing the state of record.  */
 
 static void
-mi_record_changed (struct inferior *inferior, int started)
+mi_record_changed (struct inferior *inferior, int started, const char *method,
+		   const char *format)
 {
   struct mi_interp *mi = (struct mi_interp *) top_level_interpreter_data ();
   struct cleanup *old_chain;
@@ -407,8 +409,30 @@  mi_record_changed (struct inferior *inferior, int started)
   old_chain = make_cleanup_restore_target_terminal ();
   target_terminal_ours_for_output ();
 
-  fprintf_unfiltered (mi->event_channel,  "record-%s,thread-group=\"i%d\"",
-		      started ? "started" : "stopped", inferior->num);
+  if (started)
+    {
+      if (format != NULL)
+	{
+	  fprintf_unfiltered (
+	    mi->event_channel,
+	    "record-started,thread-group=\"i%d\",method=\"%s\",format=\"%s\"",
+	    inferior->num, method, format);
+	}
+      else
+	{
+
+	  fprintf_unfiltered (
+	    mi->event_channel,
+	    "record-started,thread-group=\"i%d\",method=\"%s\"",
+	    inferior->num, method);
+	}
+    }
+  else
+    {
+      fprintf_unfiltered (mi->event_channel,
+			  "record-stopped,thread-group=\"i%d\"", inferior->num);
+    }
+
 
   gdb_flush (mi->event_channel);
 
diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 77b5180..a1df75a 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -206,6 +206,7 @@  record_btrace_open (const char *args, int from_tty)
 {
   struct cleanup *disable_chain;
   struct thread_info *tp;
+  const char *format;
 
   DEBUG ("open");
 
@@ -234,7 +235,8 @@  record_btrace_open (const char *args, int from_tty)
 				  NULL);
   record_btrace_generating_corefile = 0;
 
-  observer_notify_record_changed (current_inferior (),  1);
+  format = record_btrace_conf.format == BTRACE_FORMAT_PT ? "pt" : "bts";
+  observer_notify_record_changed (current_inferior (), 1, "btrace", format);
 
   discard_cleanups (disable_chain);
 }
diff --git a/gdb/record-full.c b/gdb/record-full.c
index f307b48..0f61bcb 100644
--- a/gdb/record-full.c
+++ b/gdb/record-full.c
@@ -869,7 +869,7 @@  record_full_open (const char *name, int from_tty)
 
   record_full_init_record_breakpoints ();
 
-  observer_notify_record_changed (current_inferior (),  1);
+  observer_notify_record_changed (current_inferior (),  1, "full", NULL);
 }
 
 /* "to_close" target method.  Close the process record target.  */
diff --git a/gdb/record.c b/gdb/record.c
index 6190794..1af134f 100644
--- a/gdb/record.c
+++ b/gdb/record.c
@@ -268,7 +268,7 @@  cmd_record_stop (char *args, int from_tty)
   printf_unfiltered (_("Process record is stopped and all execution "
 		       "logs are deleted.\n"));
 
-  observer_notify_record_changed (current_inferior (), 0);
+  observer_notify_record_changed (current_inferior (), 0, NULL, NULL);
 }
 
 /* The "set record" command.  */
diff --git a/gdb/testsuite/gdb.mi/mi-record-changed.exp b/gdb/testsuite/gdb.mi/mi-record-changed.exp
index 2b5fcd6..22cf076 100644
--- a/gdb/testsuite/gdb.mi/mi-record-changed.exp
+++ b/gdb/testsuite/gdb.mi/mi-record-changed.exp
@@ -31,14 +31,14 @@  if [mi_gdb_start] {
 }
 mi_run_to_main
 
-mi_gdb_test "record" ".*=record-started,thread-group=\"i${decimal}\".*\\^done" \
+mi_gdb_test "record" ".*=record-started,thread-group=\"i${decimal}\",method=\"full\".*\\^done" \
     "record"
 mi_gdb_test "record stop" \
     ".*=record-stopped,thread-group=\"i${decimal}\".*\\^done" \
     "record end"
 
 mi_gdb_test "target record" \
-    ".*=record-started,thread-group=\"i${decimal}\".*\\^done" \
+    ".*=record-started,thread-group=\"i${decimal}\",method=\"full\".*\\^done" \
     "target record"
 
 return 0