To know the stopped reason from hook-stop

[Masatake YAMATO <yamato at redhat dot com>]

(I am very new to this list.
 If my topic is suitable to this list, tell me the better list.)

Is there way to know in hook-stop the reason why the execution 
is stopped?

I could not find the way to do it, so I've just written a patch.
The patch is far from complete, but I'd like to know how to improve
it and integrate it to gdb official source tree. So I post the patch 
here.


The reason is passed through with $arg. 
$arg0 is the number which represents the reason; $arg0 holds the
number defined in gdb/target.h::target_waitkind. When I started working
on this patch, I'd like to pass the reason in a string. However, I 
found that a string could not be used if the debuggee process was gone.
So currently I'm using a number to represent the reason. With my patch
you can do like this in your .gdbinit:

    define hook-stop
           # show stack trace only when the debuggee is 
           # received a signal.
	   if $arg0 == 1
	      where
	   else
	      quit
	   end
    end

Regards,
Masatake YAMATO

Index: gdb/command.h
===================================================================
RCS file: /cvs/src/src/gdb/command.h,v
retrieving revision 1.56
diff -u -r1.56 command.h
--- gdb/command.h	9 Jan 2007 17:58:50 -0000	1.56
+++ gdb/command.h	31 Jul 2007 13:14:33 -0000
@@ -152,6 +152,7 @@
 /* Execute CMD's pre/post hook.  Throw an error if the command fails.
    If already executing this pre/post hook, or there is no pre/post
    hook, the call is silently ignored.  */
+extern void execute_cmd_pre_hook_with_arg (struct cmd_list_element *cmd, char *arg);
 extern void execute_cmd_pre_hook (struct cmd_list_element *cmd);
 extern void execute_cmd_post_hook (struct cmd_list_element *cmd);
 
Index: gdb/infrun.c
===================================================================
RCS file: /cvs/src/src/gdb/infrun.c,v
retrieving revision 1.244
diff -u -r1.244 infrun.c
--- gdb/infrun.c	2 Jul 2007 21:29:27 -0000	1.244
+++ gdb/infrun.c	31 Jul 2007 13:14:34 -0000
@@ -3286,7 +3286,53 @@
 static int
 hook_stop_stub (void *cmd)
 {
-  execute_cmd_pre_hook ((struct cmd_list_element *) cmd);
+  char args_buffer[128];
+  struct target_waitstatus last;
+  ptid_t last_ptid;
+
+  get_last_target_status (&last_ptid, &last);
+
+
+  args_buffer[0] = '\0';
+  switch (last.kind)
+    {
+    case TARGET_WAITKIND_EXITED:
+      sprintf(args_buffer, "%d %s %d", last.kind, "exited", last.value.integer);
+      break;
+    case TARGET_WAITKIND_STOPPED:
+      sprintf(args_buffer, "%d %s %d", last.kind, "stopped", last.value.sig);
+      break;
+    case TARGET_WAITKIND_SIGNALLED:
+      sprintf(args_buffer, "%d %s %d", last.kind, "signalled", last.value.sig);
+      break;
+    case TARGET_WAITKIND_LOADED:
+      sprintf(args_buffer, "%d %s", last.kind, "loaded");
+      break;
+    case TARGET_WAITKIND_FORKED:
+      sprintf(args_buffer, "%d %s %u", last.kind, "forked", last.value.related_pid);
+      break;
+    case TARGET_WAITKIND_VFORKED:
+      sprintf(args_buffer, "%d %s %u", last.kind, "vforked", last.value.related_pid);
+      break;
+    case TARGET_WAITKIND_EXECD:
+      // sprintf(args_buffer, "%s %s", "execd", value.execd_pathname);
+      break;
+    case TARGET_WAITKIND_SYSCALL_ENTRY:
+      sprintf(args_buffer, "%d %s %u", last.kind, "syscall_entry", last.value.syscall_id);
+      break;
+    case TARGET_WAITKIND_SYSCALL_RETURN:
+      sprintf(args_buffer, "%d %s %u", last.kind, "syscall_return", last.value.syscall_id);
+      break;
+    case TARGET_WAITKIND_SPURIOUS:
+      sprintf(args_buffer, "%d %s", last.kind, "spurious");
+      break;
+    case TARGET_WAITKIND_IGNORE:
+      sprintf(args_buffer, "%d %s", last.kind, "ignore");
+      break;
+    }
+  
+  execute_cmd_pre_hook_with_arg ((struct cmd_list_element *) cmd,
+				 args_buffer);
   return (0);
 }
 
cvs diff: Diffing gdb/cli
Index: gdb/cli/cli-script.c
===================================================================
RCS file: /cvs/src/src/gdb/cli/cli-script.c,v
retrieving revision 1.42
diff -u -r1.42 cli-script.c
--- gdb/cli/cli-script.c	3 Jul 2007 01:23:01 -0000	1.42
+++ gdb/cli/cli-script.c	31 Jul 2007 13:14:34 -0000
@@ -242,18 +242,24 @@
 }
 
 void
-execute_cmd_pre_hook (struct cmd_list_element *c)
+execute_cmd_pre_hook_with_arg (struct cmd_list_element *c, char *arg)
 {
   if ((c->hook_pre) && (!c->hook_in))
     {
       struct cleanup *cleanups = make_cleanup (clear_hook_in_cleanup, c);
       c->hook_in = 1; /* Prevent recursive hooking */
-      execute_user_command (c->hook_pre, (char *) 0);
+      execute_user_command (c->hook_pre, arg);
       do_cleanups (cleanups);
     }
 }
 
 void
+execute_cmd_pre_hook (struct cmd_list_element *c)
+{
+  execute_cmd_pre_hook_with_arg(c, (char *)0);
+}
+
+void
 execute_cmd_post_hook (struct cmd_list_element *c)
 {
   if ((c->hook_post) && (!c->hook_in))