2008-10-17 Michael Snyder <msnyder@vmware.com>

	Target interface for reverse debugging.
	* target.h (enum target_waitkind):
	Add new wait event, TARGET_WAITKIND_NO_HISTORY.
	(struct target_ops): New method to_can_execute_reverse.
	(target_can_execute_reverse): New macro.
	* target.c (update_current_target): Inherit to_can_execute_reverse.

	Remote interface for reverse debugging.
	* remote.c (remote_can_execute_reverse): New target method.
	(remote_resume): Check for reverse exec direction, and send
	appropriate command to target.
	(remote_wait_as): Check target response for NO_HISTORY status.
	Also check for empty reply (target doesn't understand "bs" or "bc).
	(remote_vcont_resume): Jump out if attempting reverse execution.

	Event handling interface for reverse debugging.
	* infrun.c (execution_direction): New state variable.
	(enum inferior_stop_reason): Add NO_HISTORY reason.
	(handle_inferior_event): Handle TARGET_WAITKIND_NO_HISTORY.
	Handle stepping over a function call in reverse.
	Handle stepping thru a line range in reverse.
	Handle setting a step-resume breakpoint in reverse.
	Handle stepping into a function in reverse.
	Handle stepping between line ranges in reverse.
	(print_stop_reason): Print reason for NO_HISTORY.
	(step_into_function): Rename to handle_step_into_function.
	(handle_step_into_function_backward): New function.
	(set_exec_direction_func, show_exec_direction_func): New funcs.
	(proceed): No need to singlestep over a breakpoint
	when resuming in reverse.

	* inferior.h (enum exec_direction_kind): New enum.
	(execution_direction): Export new execution state variable.

	* breakpoint.c (make_breakpoint_silent): New function.
	* breakpoint.h (make_breakpoint_silent): Export.
	* infcmd.c (finish_command): Check for reverse exec direction.
	(finish_backward): New function, handle finish cmd in reverse.

	User interface for reverse execution.
	* Makefile.in (reverse.c): New file.
	* reverse.c: New file.  User interface for reverse execution.

1 files changed, 13 insertions, 1 deletions

diff --git a/gdb/target.h b/gdb/target.h
index e3537c4..cdc898f 100644
--- a/gdb/target.h
+++ b/gdb/target.h
@@ -128,7 +128,11 @@ enum target_waitkind
        inferior, rather than being stuck in the remote_async_wait()
        function. This way the event loop is responsive to other events,
        like for instance the user typing.  */
-    TARGET_WAITKIND_IGNORE
+    TARGET_WAITKIND_IGNORE,
+
+    /* The target has run out of history information,
+       and cannot run backward any further.  */
+    TARGET_WAITKIND_NO_HISTORY
   };
 
 struct target_waitstatus
@@ -523,6 +527,9 @@ struct target_ops
 			     const gdb_byte *pattern, ULONGEST pattern_len,
 			     CORE_ADDR *found_addrp);
 
+    /* Can target execute in reverse?  */
+    int (*to_can_execute_reverse) ();
+
     int to_magic;
     /* Need sub-structure for target machine related rather than comm related?
      */
@@ -1127,6 +1134,11 @@ extern int target_stopped_data_address_p (struct target_ops *);
 #define target_watchpoint_addr_within_range(target, addr, start, length) \
   (*target.to_watchpoint_addr_within_range) (target, addr, start, length)
 
+/* Target can execute in reverse?  */
+#define target_can_execute_reverse \
+     (current_target.to_can_execute_reverse ? \
+      current_target.to_can_execute_reverse () : 0)
+
 extern const struct target_desc *target_read_description (struct target_ops *);
 
 /* Utility implementation of searching memory.  */