Remove cleanups from btrace code

This removes some cleanups from the btrace code by minorly C++-ifying
struct btrace_data.

gdb/ChangeLog
2018-06-08  Tom Tromey  <tom@tromey.com>

	* common/btrace-common.h (struct btrace_data): Add constructor,
	destructor, move assignment operator.
	<empty, clear, fini>: New methods.
	<format>: Initialize.
	(btrace_data_init, btrace_data_fini, btrace_data_clear)
	(btrace_data_empty): Don't declare.
	* common/btrace-common.c (btrace_data_init): Remove.
	(btrace_data::fini): Rename from btrace_data_fini.
	(btrace_data::empty): Rename from btrace_data_empty.
	(btrace_data::clear): Rename from btrace_data_clear.  Return
	bool.
	* btrace.h (make_cleanup_btrace_data): Don't declare.
	* btrace.c (btrace_add_pc, btrace_stitch_trace, btrace_clear)
	(parse_xml_btrace): Update.
	(do_btrace_data_cleanup, make_cleanup_btrace_data): Remove.
	(maint_btrace_clear_packet_history_cmd): Update.

gdb/gdbserver/ChangeLog
2018-06-08  Tom Tromey  <tom@tromey.com>

	* linux-low.c (linux_low_read_btrace): Update.

2 files changed, 45 insertions, 34 deletions

diff --git a/gdb/common/btrace-common.c b/gdb/common/btrace-common.c
index 6cbbdc1..ec0ba6a 100644
--- a/gdb/common/btrace-common.c
+++ b/gdb/common/btrace-common.c
@@ -64,28 +64,20 @@ btrace_format_short_string (enum btrace_format format)
 /* See btrace-common.h.  */
 
 void
-btrace_data_init (struct btrace_data *data)
+btrace_data::fini ()
 {
-  data->format = BTRACE_FORMAT_NONE;
-}
-
-/* See btrace-common.h.  */
-
-void
-btrace_data_fini (struct btrace_data *data)
-{
-  switch (data->format)
+  switch (format)
     {
     case BTRACE_FORMAT_NONE:
       /* Nothing to do.  */
       return;
 
     case BTRACE_FORMAT_BTS:
-      VEC_free (btrace_block_s, data->variant.bts.blocks);
+      VEC_free (btrace_block_s, variant.bts.blocks);
       return;
 
     case BTRACE_FORMAT_PT:
-      xfree (data->variant.pt.data);
+      xfree (variant.pt.data);
       return;
     }
 
@@ -94,19 +86,19 @@ btrace_data_fini (struct btrace_data *data)
 
 /* See btrace-common.h.  */
 
-int
-btrace_data_empty (struct btrace_data *data)
+bool
+btrace_data::empty () const
 {
-  switch (data->format)
+  switch (format)
     {
     case BTRACE_FORMAT_NONE:
-      return 1;
+      return true;
 
     case BTRACE_FORMAT_BTS:
-      return VEC_empty (btrace_block_s, data->variant.bts.blocks);
+      return VEC_empty (btrace_block_s, variant.bts.blocks);
 
     case BTRACE_FORMAT_PT:
-      return (data->variant.pt.size == 0);
+      return (variant.pt.size == 0);
     }
 
   internal_error (__FILE__, __LINE__, _("Unkown branch trace format."));
@@ -115,10 +107,10 @@ btrace_data_empty (struct btrace_data *data)
 /* See btrace-common.h.  */
 
 void
-btrace_data_clear (struct btrace_data *data)
+btrace_data::clear ()
 {
-  btrace_data_fini (data);
-  btrace_data_init (data);
+  fini ();
+  format = BTRACE_FORMAT_NONE;
 }
 
 /* See btrace-common.h.  */
diff --git a/gdb/common/btrace-common.h b/gdb/common/btrace-common.h
index 80e9fc6..debf833 100644
--- a/gdb/common/btrace-common.h
+++ b/gdb/common/btrace-common.h
@@ -164,7 +164,32 @@ struct btrace_data_pt
 /* The branch trace data.  */
 struct btrace_data
 {
-  enum btrace_format format;
+  btrace_data () = default;
+
+  ~btrace_data ()
+  {
+    fini ();
+  }
+
+  btrace_data &operator= (btrace_data &&other)
+  {
+    if (this != &other)
+      {
+	fini ();
+	format = other.format;
+	variant = other.variant;
+	other.format = BTRACE_FORMAT_NONE;
+      }
+    return *this;
+  }
+
+  /* Return true if this is empty; false otherwise.  */
+  bool empty () const;
+
+  /* Clear this object.  */
+  void clear ();
+
+  enum btrace_format format = BTRACE_FORMAT_NONE;
 
   union
   {
@@ -174,6 +199,12 @@ struct btrace_data
     /* Format == BTRACE_FORMAT_PT.  */
     struct btrace_data_pt pt;
   } variant;
+
+private:
+
+  DISABLE_COPY_AND_ASSIGN (btrace_data);
+
+  void fini ();
 };
 
 /* Target specific branch trace information.  */
@@ -217,18 +248,6 @@ extern const char *btrace_format_string (enum btrace_format format);
 /* Return an abbreviation string representation of FORMAT.  */
 extern const char *btrace_format_short_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);
-
-/* Clear DATA.  */
-extern void btrace_data_clear (struct btrace_data *data);
-
-/* Return non-zero if DATA is empty; zero otherwise.  */
-extern int btrace_data_empty (struct btrace_data *data);
-
 /* Append the branch trace data from SRC to the end of DST.
    Both SRC and DST must use the same format.
    Returns zero on success; a negative number otherwise.  */