record btrace: add configuration struct

Add a struct to describe the branch trace configuration and use it for
enabling branch tracing.

The user will be able to set configuration fields for each tracing format
to be used for new threads.

The actual configuration that is active for a given thread will be shown
in the "info record" command.

At the moment, the configuration struct only contains a format field
that is set to the only available format.

The format is the only configuration option that can not be set via set
commands.  It is given as argument to the "record btrace" command when
starting recording.

2015-02-09  Markus Metzger  <markus.t.metzger@intel.com>

	* Makefile.in (XMLFILES): Add btrace-conf.dtd.
	* x86-linux-nat.c (x86_linux_enable_btrace): Update parameters.
	(x86_linux_btrace_conf): New.
	(x86_linux_create_target): Initialize to_btrace_conf.
	* nat/linux-btrace.c (linux_enable_btrace): Update parameters.
	Check format.  Split into this and ...
	(linux_enable_bts): ... this.
	(linux_btrace_conf): New.
	(perf_event_skip_record): Renamed into ...
	(perf_event_skip_bts_record): ... this.  Updated users.
	(linux_disable_btrace): Split into this and ...
	(linux_disable_bts): ... this.
	(linux_read_btrace): Check format.
	* nat/linux-btrace.h (linux_enable_btrace): Update parameters.
	(linux_btrace_conf): New.
	(btrace_target_info)<ptid>: Moved.
	(btrace_target_info)<conf>: New.
	(btrace_target_info): Split into this and ...
	(btrace_tinfo_bts): ... this.  Updated users.
	* btrace.c (btrace_enable): Update parameters.
	(btrace_conf, parse_xml_btrace_conf_bts, parse_xml_btrace_conf)
	(btrace_conf_children, btrace_conf_attributes)
	(btrace_conf_elements): New.
	* btrace.h (btrace_enable): Update parameters.
	(btrace_conf, parse_xml_btrace_conf): New.
	* common/btrace-common.h (btrace_config): New.
	* feature/btrace-conf.dtd: New.
	* record-btrace.c (record_btrace_conf): New.
	(record_btrace_cmdlist): New.
	(record_btrace_enable_warn, record_btrace_open): Pass
	&record_btrace_conf.
	(record_btrace_info): Print recording format.
	(cmd_record_btrace_bts_start): New.
	(cmd_record_btrace_start): Call cmd_record_btrace_bts_start.
	(_initialize_record_btrace): Add "record btrace bts" subcommand.
	Add "record bts" alias command.
	* remote.c (remote_state)<btrace_config>: New.
	(remote_btrace_reset, PACKET_qXfer_btrace_conf): New.
	(remote_protocol_features): Add qXfer:btrace-conf:read.
	(remote_open_1): Call remote_btrace_reset.
	(remote_xfer_partial): Handle TARGET_OBJECT_BTRACE_CONF.
	(btrace_target_info)<conf>: New.
	(btrace_sync_conf, btrace_read_config): New.
	(remote_enable_btrace): Update parameters.  Call btrace_sync_conf and
	btrace_read_conf.
	(remote_btrace_conf): New.
	(init_remote_ops): Initialize to_btrace_conf.
	(_initialize_remote): Add qXfer:btrace-conf packet.
	* target.c (target_enable_btrace): Update parameters.
	(target_btrace_conf): New.
	* target.h (target_enable_btrace): Update parameters.
	(target_btrace_conf): New.
	(target_object)<TARGET_OBJECT_BTRACE_CONF>: New.
	(target_ops)<to_enable_btrace>: Update parameters and comment.
	(target_ops)<to_btrace_conf>: New.
	* target-delegates: Regenerate.
	* target-debug.h (target_debug_print_const_struct_btrace_config_p)
	(target_debug_print_const_struct_btrace_target_info_p): New.
	NEWS: Announce new command and new packet.

doc/
	* gdb.texinfo (Process Record and Replay): Describe the "record
	btrace bts" command.
	(General Query Packets): Describe qXfer:btrace-conf:read packet.
	(Branch Trace Configuration Format): New.

gdbserver/
	* linux-low.c (linux_low_enable_btrace): Update parameters.
	(linux_low_btrace_conf): New.
	(linux_target_ops)<to_btrace_conf>: Initialize.
	* server.c (current_btrace_conf): New.
	(handle_btrace_enable): Rename to ...
	(handle_btrace_enable_bts): ... this.  Pass &current_btrace_conf
	to target_enable_btrace.  Update comment.  Update users.
	(handle_qxfer_btrace_conf): New.
    (qxfer_packets): Add btrace-conf entry.
	(handle_query): Report qXfer:btrace-conf:read as supported packet.
	* target.h (target_ops)<enable_btrace>: Update parameters and comment.
	(target_ops)<read_btrace_conf>: New.
	(target_enable_btrace): Update parameters.
	(target_read_btrace_conf): New.

testsuite/
	* gdb.btrace/delta.exp: Update "info record" output.
	* gdb.btrace/enable.exp: Update "info record" output.
	* gdb.btrace/finish.exp: Update "info record" output.
	* gdb.btrace/instruction_history.exp: Update "info record" output.
	* gdb.btrace/next.exp: Update "info record" output.
	* gdb.btrace/nexti.exp: Update "info record" output.
	* gdb.btrace/step.exp: Update "info record" output.
	* gdb.btrace/stepi.exp: Update "info record" output.
	* gdb.btrace/nohist.exp: Update "info record" output.

1 files changed, 61 insertions, 8 deletions

diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 99c6684..5c6ee43 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -70,6 +70,12 @@ static struct async_event_handler *record_btrace_async_inferior_event_handler;
 /* A flag indicating that we are currently generating a core file.  */
 static int record_btrace_generating_corefile;
 
+/* The current branch trace configuration.  */
+static struct btrace_config record_btrace_conf;
+
+/* Command list for "record btrace".  */
+static struct cmd_list_element *record_btrace_cmdlist;
+
 /* Print a record-btrace debug message.  Use do ... while (0) to avoid
    ambiguities when used in if statements.  */
 
@@ -132,7 +138,7 @@ record_btrace_enable_warn (struct thread_info *tp)
   volatile struct gdb_exception error;
 
   TRY_CATCH (error, RETURN_MASK_ERROR)
-    btrace_enable (tp);
+    btrace_enable (tp, &record_btrace_conf);
 
   if (error.message != NULL)
     warning ("%s", error.message);
@@ -208,7 +214,7 @@ record_btrace_open (const char *args, int from_tty)
   ALL_NON_EXITED_THREADS (tp)
     if (args == NULL || *args == 0 || number_is_in_list (args, tp->num))
       {
-	btrace_enable (tp);
+	btrace_enable (tp, &record_btrace_conf);
 
 	make_cleanup (record_btrace_disable_callback, tp);
       }
@@ -285,6 +291,7 @@ static void
 record_btrace_info (struct target_ops *self)
 {
   struct btrace_thread_info *btinfo;
+  const struct btrace_config *conf;
   struct thread_info *tp;
   unsigned int insns, calls;
 
@@ -294,13 +301,18 @@ record_btrace_info (struct target_ops *self)
   if (tp == NULL)
     error (_("No thread."));
 
+  btinfo = &tp->btrace;
+
+  conf = btrace_conf (btinfo);
+  if (conf != NULL)
+    printf_unfiltered (_("Recording format: %s.\n"),
+		       btrace_format_string (conf->format));
+
   btrace_fetch (tp);
 
   insns = 0;
   calls = 0;
 
-  btinfo = &tp->btrace;
-
   if (!btrace_is_empty (tp))
     {
       struct btrace_call_iterator call;
@@ -1991,15 +2003,48 @@ init_record_btrace_ops (void)
   ops->to_magic = OPS_MAGIC;
 }
 
+/* Start recording in BTS format.  */
+
+static void
+cmd_record_btrace_bts_start (char *args, int from_tty)
+{
+  volatile struct gdb_exception exception;
+
+  if (args != NULL && *args != 0)
+    error (_("Invalid argument."));
+
+  record_btrace_conf.format = BTRACE_FORMAT_BTS;
+
+  TRY_CATCH (exception, RETURN_MASK_ALL)
+    execute_command ("target record-btrace", from_tty);
+
+  if (exception.error != 0)
+    {
+      record_btrace_conf.format = BTRACE_FORMAT_NONE;
+      throw_exception (exception);
+    }
+}
+
 /* Alias for "target record".  */
 
 static void
 cmd_record_btrace_start (char *args, int from_tty)
 {
+  volatile struct gdb_exception exception;
+
   if (args != NULL && *args != 0)
     error (_("Invalid argument."));
 
-  execute_command ("target record-btrace", from_tty);
+  record_btrace_conf.format = BTRACE_FORMAT_BTS;
+
+  TRY_CATCH (exception, RETURN_MASK_ALL)
+    execute_command ("target record-btrace", from_tty);
+
+  if (exception.error == 0)
+    return;
+
+  record_btrace_conf.format = BTRACE_FORMAT_NONE;
+  throw_exception (exception);
 }
 
 /* The "set record btrace" command.  */
@@ -2035,11 +2080,19 @@ void _initialize_record_btrace (void);
 void
 _initialize_record_btrace (void)
 {
-  add_cmd ("btrace", class_obscure, cmd_record_btrace_start,
-	   _("Start branch trace recording."),
-	   &record_cmdlist);
+  add_prefix_cmd ("btrace", class_obscure, cmd_record_btrace_start,
+		  _("Start branch trace recording."), &record_btrace_cmdlist,
+		  "record btrace ", 0, &record_cmdlist);
   add_alias_cmd ("b", "btrace", class_obscure, 1, &record_cmdlist);
 
+  add_cmd ("bts", class_obscure, cmd_record_btrace_bts_start,
+	   _("\
+Start branch trace recording in Branch Trace Store (BTS) format.\n\n\
+The processor stores a from/to record for each branch into a cyclic buffer.\n\
+This format may not be available on all processors."),
+	   &record_btrace_cmdlist);
+  add_alias_cmd ("bts", "btrace bts", class_obscure, 1, &record_cmdlist);
+
   add_prefix_cmd ("btrace", class_support, cmd_set_record_btrace,
 		  _("Set record options"), &set_record_btrace_cmdlist,
 		  "set record btrace ", 0, &set_record_cmdlist);