[PATCH] tui: replace deprecated_register_changed_hook with observer

[Patrick Palka <patrick@parcs.ath.cx>]

This is a straightforward replacement of the TUI's use of the
aforementioned hook with the register_changed observer.  Since this was
the only user of the hook, this patch also removes the hook.

gdb/ChangeLog:

	* defs.h (deprecated_register_changed_hook): Remove prototype.
	* interps.c (clear_iterpreter_hooks): Remove reference to
	deprecated_register_changed_hook.
	* top.c (deprecated_register_changed_hook): Remove prototype.
	* valops.c (value_assign): Remove reference to
	deprecated_register_changed_hook.
	* tui/tui-hooks.c (tui_register_changed): Add parameter "frame".
	Add comment documenting the function.
	(tui_register_changed_observer): Define.
	(tui_install_hooks): Remove reference to
	deprecated_register_changed_hook.  Set
	tui_register_changed_observer.
	(tui_remove_hooks): Remove reference to
	deprecated_register_changed_hook.  Unset
	tui_register_changed_observer.
---
 gdb/defs.h          |  1 -
 gdb/interps.c       |  1 -
 gdb/top.c           |  5 -----
 gdb/tui/tui-hooks.c | 18 +++++++++++++-----
 gdb/valops.c        |  2 --
 5 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/gdb/defs.h b/gdb/defs.h
index 32b08bb..a555da1 100644
--- a/gdb/defs.h
+++ b/gdb/defs.h
@@ -649,7 +649,6 @@ extern void (*deprecated_readline_begin_hook) (char *, ...)
      ATTRIBUTE_FPTR_PRINTF_1;
 extern char *(*deprecated_readline_hook) (const char *);
 extern void (*deprecated_readline_end_hook) (void);
-extern void (*deprecated_register_changed_hook) (int regno);
 extern void (*deprecated_context_hook) (int);
 extern ptid_t (*deprecated_target_wait_hook) (ptid_t ptid,
 					      struct target_waitstatus *status,
diff --git a/gdb/interps.c b/gdb/interps.c
index 4c1e6cc..d825e14 100644
--- a/gdb/interps.c
+++ b/gdb/interps.c
@@ -370,7 +370,6 @@ clear_interpreter_hooks (void)
   deprecated_readline_begin_hook = 0;
   deprecated_readline_hook = 0;
   deprecated_readline_end_hook = 0;
-  deprecated_register_changed_hook = 0;
   deprecated_context_hook = 0;
   deprecated_target_wait_hook = 0;
   deprecated_call_command_hook = 0;
diff --git a/gdb/top.c b/gdb/top.c
index 01fddd2..1e30b1c 100644
--- a/gdb/top.c
+++ b/gdb/top.c
@@ -221,11 +221,6 @@ void (*deprecated_detach_hook) (void);
 
 void (*deprecated_interactive_hook) (void);
 
-/* Tell the GUI someone changed the register REGNO.  -1 means
-   that the caller does not know which register changed or
-   that several registers have changed (see value_assign).  */
-void (*deprecated_register_changed_hook) (int regno);
-
 /* Called when going to wait for the target.  Usually allows the GUI
    to run while waiting for target events.  */
 
diff --git a/gdb/tui/tui-hooks.c b/gdb/tui/tui-hooks.c
index 0eb2f07..c885108 100644
--- a/gdb/tui/tui-hooks.c
+++ b/gdb/tui/tui-hooks.c
@@ -66,11 +66,18 @@ tui_new_objfile_hook (struct objfile* objfile)
 /* Prevent recursion of deprecated_register_changed_hook().  */
 static int tui_refreshing_registers = 0;
 
+/* Observer for the register_changed notification.  */
+
 static void
-tui_register_changed_hook (int regno)
+tui_register_changed (struct frame_info *frame, int regno)
 {
   struct frame_info *fi;
 
+  /* The frame of the register that was changed may differ from the selected
+     frame, but we only want to show the register values of the selected frame.
+     And even if the frames differ a register change made in one can still show
+     up in the other.  So we always use the selected frame here, and ignore
+     FRAME.  */
   fi = get_selected_frame (NULL);
   if (tui_refreshing_registers == 0)
     {
@@ -226,6 +233,7 @@ static struct observer *tui_inferior_exit_observer;
 static struct observer *tui_about_to_proceed_observer;
 static struct observer *tui_before_prompt_observer;
 static struct observer *tui_normal_stop_observer;
+static struct observer *tui_register_changed_observer;
 
 /* Install the TUI specific hooks.  */
 void
@@ -253,8 +261,8 @@ tui_install_hooks (void)
     = observer_attach_before_prompt (tui_before_prompt);
   tui_normal_stop_observer
     = observer_attach_normal_stop (tui_normal_stop);
-
-  deprecated_register_changed_hook = tui_register_changed_hook;
+  tui_register_changed_observer
+    = observer_attach_register_changed (tui_register_changed);
 }
 
 /* Remove the TUI specific hooks.  */
@@ -263,8 +271,6 @@ tui_remove_hooks (void)
 {
   deprecated_print_frame_info_listing_hook = 0;
   deprecated_query_hook = 0;
-  deprecated_register_changed_hook = 0;
-
   /* Remove our observers.  */
   observer_detach_breakpoint_created (tui_bp_created_observer);
   tui_bp_created_observer = NULL;
@@ -280,6 +286,8 @@ tui_remove_hooks (void)
   tui_before_prompt_observer = NULL;
   observer_detach_normal_stop (tui_normal_stop_observer);
   tui_normal_stop_observer = NULL;
+  observer_detach_register_changed (tui_register_changed_observer);
+  tui_register_changed_observer = NULL;
 }
 
 void _initialize_tui_hooks (void);
diff --git a/gdb/valops.c b/gdb/valops.c
index 50082c9..403e088 100644
--- a/gdb/valops.c
+++ b/gdb/valops.c
@@ -1170,8 +1170,6 @@ value_assign (struct value *toval, struct value *fromval)
 	  }
 
 	observer_notify_register_changed (frame, value_reg);
-	if (deprecated_register_changed_hook)
-	  deprecated_register_changed_hook (-1);
 	break;
       }
 
-- 
2.5.0.rc0.5.g91e10c5.dirty