[RFA] Remove unnecessary target defaults.

[Vladimir Prus <vladimir@codesourcery.com>]

In current GDB, at the bottom of the target stack, we always have dummy
target, which defines some target methods, including to_create_inferiour,
and to_attach. Those are implemented by calling find_default_attach
and find_default_create_inferior, which will call 'error' when nothing
is found.

On the other hand, update_current_target tries to set a default value
for those functions -- but because dummy target is always there, such
defaulting is not necessary. This patch removes it. No regressions on x86.

OK?

- Volodya

	* target.c (maybe_kill_then_attach)
	(maybe_kill_then_create_inferior): Remove.
	(update_current_target): Do not default to_attach,
	to_create_inferiour, to_is_async_p.
---
 gdb/target.c |   27 ---------------------------
 1 files changed, 0 insertions(+), 27 deletions(-)

diff --git a/gdb/target.c b/gdb/target.c
index 0dbe49b..050f71b 100644
--- a/gdb/target.c
+++ b/gdb/target.c
@@ -44,8 +44,6 @@
 
 static void target_info (char *, int);
 
-static void maybe_kill_then_attach (char *, int);
-
 static void kill_or_be_killed (int);
 
 static void default_terminal_info (char *, int);
@@ -358,21 +356,6 @@ kill_or_be_killed (int from_tty)
   tcomplain ();
 }
 
-static void
-maybe_kill_then_attach (char *args, int from_tty)
-{
-  kill_or_be_killed (from_tty);
-  target_attach (args, from_tty);
-}
-
-static void
-maybe_kill_then_create_inferior (char *exec, char *args, char **env,
-				 int from_tty)
-{
-  kill_or_be_killed (0);
-  target_create_inferior (exec, args, env, from_tty);
-}
-
 /* Go through the target stack from top to bottom, copying over zero
    entries in current_target, then filling in still empty entries.  In
    effect, we are doing class inheritance through the pushed target
@@ -500,8 +483,6 @@ update_current_target (void)
   de_fault (to_close,
 	    (void (*) (int))
 	    target_ignore);
-  de_fault (to_attach,
-	    maybe_kill_then_attach);
   de_fault (to_post_attach,
 	    (void (*) (int))
 	    target_ignore);
@@ -584,8 +565,6 @@ update_current_target (void)
   de_fault (to_lookup_symbol,
 	    (int (*) (char *, CORE_ADDR *))
 	    nosymbol);
-  de_fault (to_create_inferior,
-	    maybe_kill_then_create_inferior);
   de_fault (to_post_startup_inferior,
 	    (void (*) (ptid_t))
 	    target_ignore);
@@ -640,12 +619,6 @@ update_current_target (void)
   de_fault (to_pid_to_exec_file,
 	    (char *(*) (int))
 	    return_zero);
-  de_fault (to_can_async_p,
-	    (int (*) (void))
-	    return_zero);
-  de_fault (to_is_async_p,
-	    (int (*) (void))
-	    return_zero);
   de_fault (to_async,
 	    (void (*) (void (*) (enum inferior_event_type, void*), void*))
 	    tcomplain);
-- 
1.5.3.5