[patch v4 16/24] record-btrace: provide target_find_new_threads method

[Markus Metzger <markus dot t dot metzger at intel dot com>]

The "info threads" command tries to read memory, which is not possible during
replay.  This results in an error message and aborts the command without showing
the existing threads.

Provide a to_find_new_threads target method to skip the search while replaying.

2013-07-03  Markus Metzger <markus.t.metzger@intel.com>

	* record-btrace.c (record_btrace_find_new_threads): New.
	(init_record_btrace_ops): Initialize to_find_new_threads.


---
 gdb/record-btrace.c |   19 +++++++++++++++++++
 1 files changed, 19 insertions(+), 0 deletions(-)

diff --git a/gdb/record-btrace.c b/gdb/record-btrace.c
index 430296a..2b552d5 100644
--- a/gdb/record-btrace.c
+++ b/gdb/record-btrace.c
@@ -1005,6 +1005,24 @@ record_btrace_wait (struct target_ops *ops, ptid_t ptid,
   error (_("You can't do this from here.  Do 'record goto end', first."));
 }
 
+/* The to_find_new_threads method of target record-btrace.  */
+
+static void
+record_btrace_find_new_threads (struct target_ops *ops)
+{
+  /* Don't expect new threads if we're replaying.  */
+  if (record_btrace_is_replaying ())
+    return;
+
+  /* Forward the request.  */
+  for (ops = ops->beneath; ops != NULL; ops = ops->beneath)
+    if (ops->to_find_new_threads != NULL)
+      {
+	ops->to_find_new_threads (ops);
+	break;
+      }
+}
+
 /* Initialize the record-btrace target ops.  */
 
 static void
@@ -1039,6 +1057,7 @@ init_record_btrace_ops (void)
   ops->to_get_unwinder = &record_btrace_frame_unwind;
   ops->to_resume = record_btrace_resume;
   ops->to_wait = record_btrace_wait;
+  ops->to_find_new_threads = record_btrace_find_new_threads;
   ops->to_stratum = record_stratum;
   ops->to_magic = OPS_MAGIC;
 }
-- 
1.7.1