[RFC 06/32] convert to_supports_btrace

[Tom Tromey <tromey@redhat.com>]

---
 gdb/common/linux-btrace.c |  4 ++--
 gdb/common/linux-btrace.h |  2 +-
 gdb/gdbserver/target.h    |  7 ++++---
 gdb/remote.c              |  2 +-
 gdb/target-delegates.c    | 16 ++++++++++++++++
 gdb/target.c              | 14 --------------
 gdb/target.h              |  6 ++++--
 7 files changed, 28 insertions(+), 23 deletions(-)

diff --git a/gdb/common/linux-btrace.c b/gdb/common/linux-btrace.c
index 7e20745..b3d1aaa 100644
--- a/gdb/common/linux-btrace.c
+++ b/gdb/common/linux-btrace.c
@@ -400,7 +400,7 @@ cpu_supports_btrace (void)
 /* See linux-btrace.h.  */
 
 int
-linux_supports_btrace (void)
+linux_supports_btrace (struct target_ops *ops)
 {
   static int cached;
 
@@ -554,7 +554,7 @@ linux_read_btrace (struct btrace_target_info *tinfo,
 /* See linux-btrace.h.  */
 
 int
-linux_supports_btrace (void)
+linux_supports_btrace (struct target_ops *ops)
 {
   return 0;
 }
diff --git a/gdb/common/linux-btrace.h b/gdb/common/linux-btrace.h
index d4e8402..16c4bb1 100644
--- a/gdb/common/linux-btrace.h
+++ b/gdb/common/linux-btrace.h
@@ -62,7 +62,7 @@ struct btrace_target_info
 };
 
 /* Check whether branch tracing is supported.  */
-extern int linux_supports_btrace (void);
+extern int linux_supports_btrace (struct target_ops *);
 
 /* Enable branch tracing for @ptid.  */
 extern struct btrace_target_info *linux_enable_btrace (ptid_t ptid);
diff --git a/gdb/gdbserver/target.h b/gdb/gdbserver/target.h
index c5e6fee..277838d 100644
--- a/gdb/gdbserver/target.h
+++ b/gdb/gdbserver/target.h
@@ -350,7 +350,7 @@ struct target_ops
   int (*supports_agent) (void);
 
   /* Check whether the target supports branch tracing.  */
-  int (*supports_btrace) (void);
+  int (*supports_btrace) (struct target_ops *);
 
   /* Enable branch tracing for @ptid and allocate a branch trace target
      information struct for reading and for disabling branch trace.  */
@@ -488,8 +488,9 @@ int kill_inferior (int);
   (the_target->supports_agent ? \
    (*the_target->supports_agent) () : 0)
 
-#define target_supports_btrace() \
-  (the_target->supports_btrace ? (*the_target->supports_btrace) () : 0)
+#define target_supports_btrace()			\
+  (the_target->supports_btrace				\
+   ? (*the_target->supports_btrace) (the_target) : 0)
 
 #define target_enable_btrace(ptid) \
   (*the_target->enable_btrace) (ptid)
diff --git a/gdb/remote.c b/gdb/remote.c
index a91e6aa..6f3fc91 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -11340,7 +11340,7 @@ struct btrace_target_info
 /* Check whether the target supports branch tracing.  */
 
 static int
-remote_supports_btrace (void)
+remote_supports_btrace (struct target_ops *self)
 {
   if (remote_protocol_packets[PACKET_Qbtrace_off].support != PACKET_ENABLE)
     return 0;
diff --git a/gdb/target-delegates.c b/gdb/target-delegates.c
index 484945f..77f3113 100644
--- a/gdb/target-delegates.c
+++ b/gdb/target-delegates.c
@@ -122,6 +122,19 @@ tdefault_xfer_partial (struct target_ops *self, enum target_object  arg1, const
   return -1;
 }
 
+static int
+delegate_supports_btrace (struct target_ops *self)
+{
+  self = self->beneath;
+  return self->to_supports_btrace (self);
+}
+
+static int
+tdefault_supports_btrace (struct target_ops *self)
+{
+  return 0;
+}
+
 static void
 install_delegators (struct target_ops *ops)
 {
@@ -147,6 +160,8 @@ install_delegators (struct target_ops *ops)
     ops->to_async = delegate_async;
   if (ops->to_xfer_partial == NULL)
     ops->to_xfer_partial = delegate_xfer_partial;
+  if (ops->to_supports_btrace == NULL)
+    ops->to_supports_btrace = delegate_supports_btrace;
 }
 
 static void
@@ -163,4 +178,5 @@ install_dummy_methods (struct target_ops *ops)
   ops->to_is_async_p = find_default_is_async_p;
   ops->to_async = tdefault_async;
   ops->to_xfer_partial = tdefault_xfer_partial;
+  ops->to_supports_btrace = tdefault_supports_btrace;
 }
diff --git a/gdb/target.c b/gdb/target.c
index 0f614bf..6fc95fc 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -4090,20 +4090,6 @@ target_ranged_break_num_registers (void)
 
 /* See target.h.  */
 
-int
-target_supports_btrace (void)
-{
-  struct target_ops *t;
-
-  for (t = current_target.beneath; t != NULL; t = t->beneath)
-    if (t->to_supports_btrace != NULL)
-      return t->to_supports_btrace ();
-
-  return 0;
-}
-
-/* See target.h.  */
-
 struct btrace_target_info *
 target_enable_btrace (ptid_t ptid)
 {
diff --git a/gdb/target.h b/gdb/target.h
index 538bdf4..d1fa12f 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -854,7 +854,8 @@ struct target_ops
     int (*to_can_use_agent) (void);
 
     /* Check whether the target supports branch tracing.  */
-    int (*to_supports_btrace) (void);
+    int (*to_supports_btrace) (struct target_ops *)
+      TARGET_DEFAULT_RETURN (0);
 
     /* Enable branch tracing for PTID and allocate a branch trace target
        information struct for reading and for disabling branch trace.  */
@@ -1988,7 +1989,8 @@ extern void update_target_permissions (void);
 void target_ignore (void);
 
 /* See to_supports_btrace in struct target_ops.  */
-extern int target_supports_btrace (void);
+#define target_supports_btrace() \
+  (current_target.to_supports_btrace (&current_target))
 
 /* See to_enable_btrace in struct target_ops.  */
 extern struct btrace_target_info *target_enable_btrace (ptid_t ptid);
-- 
1.8.1.4