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, 27 insertions, 8 deletions

diff --git a/gdb/nat/linux-btrace.h b/gdb/nat/linux-btrace.h
index 602a571..12cdcde 100644
--- a/gdb/nat/linux-btrace.h
+++ b/gdb/nat/linux-btrace.h
@@ -48,18 +48,13 @@ struct perf_event_buffer
   /* The data_head value from the last read.  */
   unsigned long long last_head;
 };
-#endif /* HAVE_LINUX_PERF_EVENT_H */
 
-/* Branch trace target information per thread.  */
-struct btrace_target_info
+/* Branch trace target information for BTS tracing.  */
+struct btrace_tinfo_bts
 {
-#if HAVE_LINUX_PERF_EVENT_H
   /* The Linux perf_event configuration for collecting the branch trace.  */
   struct perf_event_attr attr;
 
-  /* The ptid of this thread.  */
-  ptid_t ptid;
-
   /* The perf event file.  */
   int file;
 
@@ -68,6 +63,25 @@ struct btrace_target_info
 
   /* The BTS perf event buffer.  */
   struct perf_event_buffer bts;
+};
+#endif /* HAVE_LINUX_PERF_EVENT_H */
+
+/* Branch trace target information per thread.  */
+struct btrace_target_info
+{
+  /* The ptid of this thread.  */
+  ptid_t ptid;
+
+  /* The obtained branch trace configuration.  */
+  struct btrace_config conf;
+
+#if HAVE_LINUX_PERF_EVENT_H
+  /* The branch tracing format specific information.  */
+  union
+  {
+    /* CONF.FORMAT == BTRACE_FORMAT_BTS.  */
+    struct btrace_tinfo_bts bts;
+  } variant;
 #endif /* HAVE_LINUX_PERF_EVENT_H */
 
   /* The size of a pointer in bits for this thread.
@@ -80,7 +94,8 @@ struct btrace_target_info
 extern int linux_supports_btrace (struct target_ops *, enum btrace_format);
 
 /* See to_enable_btrace in target.h.  */
-extern struct btrace_target_info *linux_enable_btrace (ptid_t ptid);
+extern struct btrace_target_info *
+  linux_enable_btrace (ptid_t ptid, const struct btrace_config *conf);
 
 /* See to_disable_btrace in target.h.  */
 extern enum btrace_error linux_disable_btrace (struct btrace_target_info *ti);
@@ -90,4 +105,8 @@ extern enum btrace_error linux_read_btrace (struct btrace_data *btrace,
 					    struct btrace_target_info *btinfo,
 					    enum btrace_read_type type);
 
+/* See to_btrace_conf in target.h.  */
+extern const struct btrace_config *
+  linux_btrace_conf (const struct btrace_target_info *);
+
 #endif /* LINUX_BTRACE_H */