btrace: add struct btrace_data

Add a structure to hold the branch trace data and an enum to describe
the format of that data.  So far, only BTS is supported.  Also added
a NONE format to indicate that no branch trace data is available.

This will make it easier to support different branch trace formats in
the future.

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

	* Makefile.in (SFILES): Add common/btrace-common.c.
	(COMMON_OBS): Add common/btrace-common.o.
	(btrace-common.o): Add build rules.
	* btrace.c (parse_xml_btrace): Update parameters.
	(parse_xml_btrace_block): Set format field.
	(btrace_add_pc, btrace_fetch): Use struct btrace_data.
	(do_btrace_data_cleanup, make_cleanup_btrace_data): New.
	(btrace_compute_ftrace): Split into this and...
	(btrace_compute_ftrace_bts): ...this.
	(btrace_stitch_trace): Split into this and...
	(btrace_stitch_bts): ...this.
	* btrace.h (parse_xml_btrace): Update parameters.
	(make_cleanup_btrace_data): New.
	* common/btrace-common.c: New.
	* common/btrace-common.h: Include common-defs.h.
	(btrace_block_s): Update comment.
	(btrace_format): New.
	(btrace_format_string): New.
	(btrace_data_bts): New.
	(btrace_data): New.
	(btrace_data_init, btrace_data_fini, btrace_data_empty): New.
	* remote.c (remote_read_btrace): Update parameters.
	* target.c (target_read_btrace): Update parameters.
	* target.h (target_read_btrace): Update parameters.
	(target_ops)<to_read_btrace>: Update parameters.
	* x86-linux-nat.c (x86_linux_read_btrace): Update parameters.
	* target-delegates.c: Regenerate.
	* target-debug (target_debug_print_struct_btrace_data_p): New.
	* nat/linux-btrace.c (linux_read_btrace): Split into this and...
	(linux_read_bts): ...this.
	* nat/linux-btrace.h (linux_read_btrace): Update parameters.

gdbserver/
	* Makefile.in (SFILES): Add common/btrace-common.c.
	(OBS): Add common/btrace-common.o.
	(btrace-common.o): Add build rules.
	* linux-low: Include btrace-common.h.
	(linux_low_read_btrace): Use struct btrace_data.  Call
	btrace_data_init and btrace_data_fini.

gdb/common/btrace-common.c

@@ -0,0 +1,83 @@
+/* Copyright (C) 2014-2015 Free Software Foundation, Inc.
+
+   Contributed by Intel Corp. <markus.t.metzger@intel.com>
+
+   This file is part of GDB.
+
+   This program is free software; you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+#include "common-defs.h"
+#include "btrace-common.h"
+
+
+/* See btrace-common.h.  */
+
+const char *
+btrace_format_string (enum btrace_format format)
+{
+  switch (format)
+    {
+    case BTRACE_FORMAT_NONE:
+      return _("No or unknown format");
+
+    case BTRACE_FORMAT_BTS:
+      return _("Branch Trace Store");
+    }
+
+  internal_error (__FILE__, __LINE__, _("Unknown branch trace format"));
+}
+
+/* See btrace-common.h.  */
+
+void
+btrace_data_init (struct btrace_data *data)
+{
+  data->format = BTRACE_FORMAT_NONE;
+}
+
+/* See btrace-common.h.  */
+
+void
+btrace_data_fini (struct btrace_data *data)
+{
+  switch (data->format)
+    {
+    case BTRACE_FORMAT_NONE:
+      /* Nothing to do.  */
+      return;
+
+    case BTRACE_FORMAT_BTS:
+      VEC_free (btrace_block_s, data->variant.bts.blocks);
+      return;
+    }
+
+  internal_error (__FILE__, __LINE__, _("Unkown branch trace format."));
+}
+
+/* See btrace-common.h.  */
+
+int
+btrace_data_empty (struct btrace_data *data)
+{
+  switch (data->format)
+    {
+    case BTRACE_FORMAT_NONE:
+      return 1;
+
+    case BTRACE_FORMAT_BTS:
+      return VEC_empty (btrace_block_s, data->variant.bts.blocks);
+    }
+
+  internal_error (__FILE__, __LINE__, _("Unkown branch trace format."));
+}

gdb/common/btrace-common.h

@@ -45,13 +45,42 @@ struct btrace_block
   CORE_ADDR end;
 };
 
-/* Branch trace is represented as a vector of branch trace blocks starting with
-   the most recent block.  */
-typedef struct btrace_block btrace_block_s;
-
 /* Define functions operating on a vector of branch trace blocks.  */
+typedef struct btrace_block btrace_block_s;
 DEF_VEC_O (btrace_block_s);
 
+/* Enumeration of btrace formats.  */
+
+enum btrace_format
+{
+  /* No branch trace format.  */
+  BTRACE_FORMAT_NONE,
+
+  /* Branch trace is in Branch Trace Store (BTS) format.
+     Actually, the format is a sequence of blocks derived from BTS.  */
+  BTRACE_FORMAT_BTS
+};
+
+/* Branch trace in BTS format.  */
+struct btrace_data_bts
+{
+  /* Branch trace is represented as a vector of branch trace blocks starting
+     with the most recent block.  */
+  VEC (btrace_block_s) *blocks;
+};
+
+/* The branch trace data.  */
+struct btrace_data
+{
+  enum btrace_format format;
+
+  union
+  {
+    /* Format == BTRACE_FORMAT_BTS.  */
+    struct btrace_data_bts bts;
+  } variant;
+};
+
 /* Target specific branch trace information.  */
 struct btrace_target_info;
 
@@ -87,4 +116,16 @@ enum btrace_error
   BTRACE_ERR_OVERFLOW
 };
 
+/* Return a string representation of FORMAT.  */
+extern const char *btrace_format_string (enum btrace_format format);
+
+/* Initialize DATA.  */
+extern void btrace_data_init (struct btrace_data *data);
+
+/* Cleanup DATA.  */
+extern void btrace_data_fini (struct btrace_data *data);
+
+/* Return non-zero if DATA is empty; zero otherwise.  */
+extern int btrace_data_empty (struct btrace_data *data);
+
 #endif /* BTRACE_COMMON_H */