Simplify target_async hook interface

All callers of target_async pass it the same callback
(inferior_event_handler).  Since both common code and target backends
need to be able to put the target in and out of target async mode at
any given time, there's really no way that a different callback could
be passed.  This commit simplifies things, and removes the indirection
altogether.  Bonus: with this, gdb's target_async method ends up with
the same signature as gdbserver's.

Tested on x86_64 Fedora 20, native and gdbserver.

gdb/ChangeLog:
2015-03-25  Pedro Alves  <palves@redhat.com>

	* target.h <to_async>: Replace 'callback' and 'context' parameters
	with boolean 'enable' parameter.
	(target_async): Replace CALLBACK and CONTEXT parameters with
	boolean ENABLE parameter.
	* inf-loop.c (inferior_event_handler): Adjust.
	* linux-nat.c (linux_nat_attach, linux_nat_resume)
	(linux_nat_resume): Adjust.
	(async_client_callback, async_client_context): Delete.
	(handle_target_event): Call inferior_event_handler directly.
	(linux_nat_async): Replace 'callback' and 'context' parameters
	with boolean 'enable' parameter.  Adjust.  Remove references to
	async_client_callback and async_client_context.
	(linux_nat_close): Adjust.
	* record-btrace.c (record_btrace_async): Replace 'callback' and
	'context' parameters with boolean 'enable' parameter.  Adjust.
	(record_btrace_resume): Adjust.
	* record-full.c (record_full_async): Replace 'callback' and
	'context' parameters with boolean 'enable' parameter.  Adjust.
	(record_full_resume, record_full_core_resume): Adjust.
	* remote.c (struct remote_state) <async_client_callback,
	async_client_context>: Delete fields.
	(remote_start_remote, extended_remote_attach_1, remote_resume)
	(extended_remote_create_inferior): Adjust.
	(remote_async_serial_handler): Call inferior_event_handler
	directly.
	(remote_async): Replace 'callback' and 'context' parameters with
	boolean 'enable' parameter.  Adjust.
	* top.c (gdb_readline_wrapper_cleanup, gdb_readline_wrapper):
	Adjust.
	* target-delegates.c: Regenerate.

1 files changed, 4 insertions, 4 deletions

diff --git a/gdb/target.h b/gdb/target.h
index 05dcd9f..19254d6 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -629,7 +629,7 @@ struct target_ops
       TARGET_DEFAULT_RETURN (0);
     int (*to_is_async_p) (struct target_ops *)
       TARGET_DEFAULT_RETURN (0);
-    void (*to_async) (struct target_ops *, async_callback_ftype *, void *)
+    void (*to_async) (struct target_ops *, int)
       TARGET_DEFAULT_NORETURN (tcomplain ());
     /* This method must be implemented in some situations.  See the
        comment on 'to_can_run'.  */
@@ -1686,9 +1686,9 @@ extern int target_async_permitted;
 /* Is the target in asynchronous execution mode?  */
 #define target_is_async_p() (current_target.to_is_async_p (&current_target))
 
-/* Put the target in async mode with the specified callback function.  */
-#define target_async(CALLBACK,CONTEXT) \
-     (current_target.to_async (&current_target, (CALLBACK), (CONTEXT)))
+/* Enables/disabled async target events.  */
+#define target_async(ENABLE) \
+     (current_target.to_async (&current_target, (ENABLE)))
 
 #define target_execution_direction() \
   (current_target.to_execution_direction (&current_target))