As preparation for non-stop and multi-process support in the remote
targets, I'd like to get rid of the current async duplication in remote.c.

The remote_wait/remote_async_wait merge is a bit hard to see in the
attached patch.  Below is a diff of both functions I used
to make sure nothing was left behind.

To get async behaviour, enable remote async support with 'maint set 
remote-async', and use 'target remote' to connect as normal.  Target
async and target extended-async are gone.

Here's remote_wait/remote_async_wait:

--- remote_sync.txt	2008-05-17 15:45:13.000000000 +0100
+++ remote_async.txt	2008-05-17 15:45:33.000000000 +0100
@@ -1,5 +1,5 @@
 static ptid_t
-remote_wait (ptid_t ptid, struct target_waitstatus *status)
+remote_async_wait (ptid_t ptid, struct target_waitstatus *status)
 {
   struct remote_state *rs = get_remote_state ();
   struct remote_arch_state *rsa = get_remote_arch_state ();
@@ -10,6 +10,8 @@ remote_wait (ptid_t ptid, struct target_
   status->kind = TARGET_WAITKIND_EXITED;
   status->value.integer = 0;
 
+  remote_stopped_by_watchpoint_p = 0;
+
   while (1)
     {
       char *buf, *p;
@@ -19,22 +21,28 @@ remote_wait (ptid_t ptid, struct target_
 	rs->cached_wait_status = 0;
       else
 	{
-	  ofunc = signal (SIGINT, remote_interrupt);
-	  /* If the user hit C-c before this packet, or between packets,
-	     pretend that it was hit right here.  */
-	  if (quit_flag)
+	  if (!target_is_async_p ())
 	    {
-	      quit_flag = 0;
-	      remote_interrupt (SIGINT);
+	      ofunc = signal (SIGINT, remote_interrupt);
+	      /* If the user hit C-c before this packet, or between packets,
+		 pretend that it was hit right here.  */
+	      if (quit_flag)
+		{
+		  quit_flag = 0;
+		  remote_interrupt (SIGINT);
+		}
 	    }
-	  getpkt (&rs->buf, &rs->buf_size, 1);
-	  signal (SIGINT, ofunc);
+	  /* FIXME: cagney/1999-09-27: If we're in async mode we should
+	     _never_ wait for ever -> test on target_is_async_p().
+	     However, before we do that we need to ensure that the caller
+	     knows how to take the target into/out of async mode.  */
+	  getpkt (&rs->buf, &rs->buf_size, wait_forever_enabled_p);
+	  if (!target_is_async_p ())
+	    signal (SIGINT, ofunc);
 	}
 
       buf = rs->buf;
 
-      remote_stopped_by_watchpoint_p = 0;
-
       switch (buf[0])
 	{
 	case 'E':		/* Error of some sort.  */
@@ -64,18 +72,18 @@ remote_wait (ptid_t ptid, struct target_
 		char *p1;
 		char *p_temp;
 		int fieldsize;
-		LONGEST pnum = 0;
+		long pnum = 0;
 
-		/* If the packet contains a register number save it in
-		   pnum and set p1 to point to the character following
-		   it.  Otherwise p1 points to p.  */
+		/* If the packet contains a register number, save it
+		   in pnum and set p1 to point to the character
+		   following it.  Otherwise p1 points to p.  */
 
-		/* If this packet is an awatch packet, don't parse the
-		   'a' as a register number.  */
+		/* If this packet is an awatch packet, don't parse the 'a'
+		   as a register number.  */
 
 		if (strncmp (p, "awatch", strlen("awatch")) != 0)
 		  {
-		    /* Read the ``P'' register number.  */
+		    /* Read the register number.  */
 		    pnum = strtol (p, &p_temp, 16);
 		    p1 = p_temp;
 		  }
@@ -121,20 +129,20 @@ Packet: '%s'\n"),
 			  p = p_temp;
  		      }
 		  }
+
 		else
 		  {
 		    struct packet_reg *reg = packet_reg_from_pnum (rsa, pnum);
 		    p = p1;
-
 		    if (*p++ != ':')
 		      error (_("Malformed packet(b) (missing colon): %s\n\
 Packet: '%s'\n"),
 			     p, buf);
 
 		    if (reg == NULL)
-		      error (_("Remote sent bad register number %s: %s\n\
+		      error (_("Remote sent bad register number %ld: %s\n\
 Packet: '%s'\n"),
-			     phex_nz (pnum, 0), p, buf);
+			     pnum, p, buf);
 
 		    fieldsize = hex2bin (p, regs,
 					 register_size (current_gdbarch,
@@ -184,7 +192,10 @@ Packet: '%s'\n"),
 	  goto got_status;
 	case 'O':		/* Console output.  */
 	  remote_console_output (buf + 1);
-	  continue;
+	  /* Return immediately to the event loop. The event loop will
+             still be waiting on the inferior afterwards.  */
+          status->kind = TARGET_WAITKIND_IGNORE;
+          goto got_status;
 	case '\0':
 	  if (last_sent_signal != TARGET_SIGNAL_0)
 	    {

Tested on with a local gdbserver on x86-64-unknown-linux-gnu, in sync
mode, with and without this patch; and async mode also with and without
this patch.  No regressions in both modes, compared to unpatched.

(applies on top of the kill kill_kludge patch I sent a bit earlier
today.)

OK?

-- 
Pedro Alves