[commit+7.6] [patch] Fix remote.c incorrectly using pop_target (wrt btrace)

[Jan Kratochvil <jan dot kratochvil at redhat dot com>]

On Fri, 22 Mar 2013 17:58:01 +0100, Pedro Alves wrote:
> On 03/15/2013 07:54 PM, Jan Kratochvil wrote:
> 
> > gdb/
> > 2013-03-15  Jan Kratochvil  <jan.kratochvil@redhat.com>
> > 
> > 	* remote.c (remote_unpush_target): New function.
> > 	(remote_open_1): Remove two pop_target calls, update one comment, add
> > 	comment to target_preopen call.  Replace pop_target call by
> > 	remote_unpush_target call.
> > 	(interrupt_query, readchar, getpkt_or_notif_sane_1): Replace
> > 	pop_target calls by remote_unpush_target calls.
> > 
> 
> Thanks.  I think this is fine.

Checked in:
	http://sourceware.org/ml/gdb-cvs/2013-03/msg00193.html
and for 7.6.
	http://sourceware.org/ml/gdb-cvs/2013-03/msg00194.html
	(This one has additional ", 0" for the QUITTING parameter.)


> I notice that some targets, like spu-multiarch.c or dec-thread.c
> don't seem to be very prepared to be brute-force deactivated.  E.g.,
> those targets (and linux-thread-db.c and bsd-uthread.c too), probably
> more) are deactivated when symbols or shared libraries are unloaded,
> and their to_close methods don't take care of cleaning up the target's
> variables / local state.  A similar scenario that doesn't
> involve remote, is when going from 'threaded core debugging'
>   -> 'non-threaded core debugging'.  But since target_pre_inferior
> discards the DSOs of the current inferior, and these targets are
> generally not multi-inferior aware, I guess things end up alright.
> This is very much a preexisting wart.  I suspect we'll end up
> getting back to this at some not-so-distant point.  :-)

OK, I did not notice before.


Thanks,
Jan


http://sourceware.org/ml/gdb-cvs/2013-03/msg00193.html

--- src/gdb/ChangeLog	2013/03/22 14:52:26	1.15301
+++ src/gdb/ChangeLog	2013/03/22 19:07:03	1.15302
@@ -1,3 +1,12 @@
+2013-03-22  Jan Kratochvil  <jan.kratochvil@redhat.com>
+
+	* remote.c (remote_unpush_target): New function.
+	(remote_open_1): Remove two pop_target calls, update one comment, add
+	comment to target_preopen call.  Replace pop_target call by
+	remote_unpush_target call.
+	(interrupt_query, readchar, getpkt_or_notif_sane_1): Replace
+	pop_target calls by remote_unpush_target calls.
+
 2013-03-22  Pedro Alves  <palves@redhat.com>
 
 	* linux-nat.c (linux_child_follow_fork): Don't call
--- src/gdb/remote.c	2013/03/20 15:46:24	1.530
+++ src/gdb/remote.c	2013/03/22 19:07:03	1.531
@@ -4188,6 +4188,14 @@
       }
 }
 
+/* Remove any of the remote.c targets from target stack.  Upper targets depend
+   on it so remove them first.  */
+
+static void
+remote_unpush_target (void)
+{
+  pop_all_targets_above (process_stratum - 1);
+}
 
 static void
 remote_open_1 (char *name, int from_tty,
@@ -4205,30 +4213,18 @@
     wait_forever_enabled_p = 1;
 
   /* If we're connected to a running target, target_preopen will kill it.
-     But if we're connected to a target system with no running process,
-     then we will still be connected when it returns.  Ask this question
-     first, before target_preopen has a chance to kill anything.  */
+     Ask this question first, before target_preopen has a chance to kill
+     anything.  */
   if (remote_desc != NULL && !have_inferiors ())
     {
-      if (!from_tty
-	  || query (_("Already connected to a remote target.  Disconnect? ")))
-	pop_target ();
-      else
+      if (from_tty
+	  && !query (_("Already connected to a remote target.  Disconnect? ")))
 	error (_("Still connected."));
     }
 
+  /* Here the possibly existing remote target gets unpushed.  */
   target_preopen (from_tty);
 
-  unpush_target (target);
-
-  /* This time without a query.  If we were connected to an
-     extended-remote target and target_preopen killed the running
-     process, we may still be connected.  If we are starting "target
-     remote" now, the extended-remote target will not have been
-     removed by unpush_target.  */
-  if (remote_desc != NULL && !have_inferiors ())
-    pop_target ();
-
   /* Make sure we send the passed signals list the next time we resume.  */
   xfree (last_pass_packet);
   last_pass_packet = NULL;
@@ -4348,7 +4344,7 @@
 	/* Pop the partially set up target - unless something else did
 	   already before throwing the exception.  */
 	if (remote_desc != NULL)
-	  pop_target ();
+	  remote_unpush_target ();
 	if (target_async_permitted)
 	  wait_forever_enabled_p = 1;
 	throw_exception (ex);
@@ -5096,7 +5092,7 @@
       if (query (_("Interrupted while waiting for the program.\n\
 Give up (and stop debugging it)? ")))
 	{
-	  pop_target ();
+	  remote_unpush_target ();
 	  deprecated_throw_reason (RETURN_QUIT);
 	}
     }
@@ -7051,11 +7047,11 @@
   switch ((enum serial_rc) ch)
     {
     case SERIAL_EOF:
-      pop_target ();
+      remote_unpush_target ();
       error (_("Remote connection closed"));
       /* no return */
     case SERIAL_ERROR:
-      pop_target ();
+      remote_unpush_target ();
       perror_with_name (_("Remote communication error.  "
 			  "Target disconnected."));
       /* no return */
@@ -7579,7 +7575,7 @@
 	      if (forever)	/* Watchdog went off?  Kill the target.  */
 		{
 		  QUIT;
-		  pop_target ();
+		  remote_unpush_target ();
 		  error (_("Watchdog timeout has expired.  Target detached."));
 		}
 	      if (remote_debug)