+/* Handle btrace enabling. */
+
+static const char *
+handle_btrace_enable (struct thread_info *thread)
+{
+ if (thread->btrace != NULL)
+ return "E.Btrace already enabled.";
+
+ thread->btrace = target_enable_btrace (thread->entry.id);
+ if (thread->btrace == NULL)
+ return "E.Could not enable btrace.";
+
+ return NULL;
+}
+
+/* Handle btrace disabling. */
+
+static const char *
+handle_btrace_disable (struct thread_info *thread)
+{
+
+ if (thread->btrace == NULL)
+ return "E.Branch tracing not enabled.";
+
+ if (target_disable_btrace (thread->btrace) != 0)
+ return "E.Could not disable branch tracing.";
+
+ thread->btrace = NULL;
+ return NULL;
+}
+
+/* Handle the "Qbtrace" packet. */
+
+static int
+handle_btrace_general_set (char *own_buf)
+{
+ struct thread_info *thread;
+ const char *err;
+ char *op;
+
+ if (strncmp ("Qbtrace:", own_buf, strlen ("Qbtrace:")) != 0)
+ return 0;
+
+ op = own_buf + strlen ("Qbtrace:");
+
+ if (!target_supports_btrace ())
+ {
+ strcpy (own_buf, "E.Target does not support branch tracing.");
+ return -1;
+ }
+
+ if (ptid_equal (general_thread, null_ptid)
+ || ptid_equal (general_thread, minus_one_ptid))
+ {
+ strcpy (own_buf, "E.Must select a single thread.");
+ return -1;
+ }
+
+ thread = find_thread_ptid (general_thread);
+ if (thread == NULL)
+ {
+ strcpy (own_buf, "E.No such thread.");
+ return -1;
+ }
+
+ err = NULL;
+
+ if (strcmp (op, "bts") == 0)
+ err = handle_btrace_enable (thread);
+ else if (strcmp (op, "off") == 0)
+ err = handle_btrace_disable (thread);
+ else
+ err = "E.Bad Qbtrace operation. Use bts or off.";
+
+ if (err != 0)
+ strcpy (own_buf, err);
+ else
+ write_ok (own_buf);
+
+ return 1;
+}
+