gdbserver: Move detach code to its own function

The code required to handle the 'D' packet is non trivial, so move it
out to its own function.

The moved out code is identical, except for the call to strtol and some
breaks that became returns.

Tested manually, and by running gdb.base/*detach*.exp with
native-gdbserver and native-extended-gdbserver.

gdb/gdbserver/ChangeLog:

	* server.c (handle_detach): New function.
	(process_serial_event): Move code out, call handle_detach.

2 files changed, 101 insertions, 90 deletions

diff --git a/gdb/gdbserver/ChangeLog b/gdb/gdbserver/ChangeLog
index d7980b0dbd9..144e09afa32 100644
--- a/gdb/gdbserver/ChangeLog
+++ b/gdb/gdbserver/ChangeLog
@@ -1,5 +1,10 @@
 2017-09-15  Simon Marchi  <simon.marchi@ericsson.com>
 
+	* server.c (handle_detach): New function.
+	(process_serial_event): Move code out, call handle_detach.
+
+2017-09-15  Simon Marchi  <simon.marchi@ericsson.com>
+
 	* server.c (require_running): Rename to ...
 	(require_running_or_return): ... this ...
 	(require_running_or_break): ... and this.
diff --git a/gdb/gdbserver/server.c b/gdb/gdbserver/server.c
index 8e0bf5ba789..3de7f163412 100644
--- a/gdb/gdbserver/server.c
+++ b/gdb/gdbserver/server.c
@@ -1157,6 +1157,100 @@ handle_search_memory (char *own_buf, int packet_len)
   free (pattern);
 }
 
+/* Handle the "D" packet.  */
+
+static void
+handle_detach (char *own_buf)
+{
+  require_running_or_return (own_buf);
+
+  int pid;
+
+  if (multi_process)
+    {
+      /* skip 'D;' */
+      pid = strtol (&own_buf[2], NULL, 16);
+    }
+  else
+    pid = ptid_get_pid (current_ptid);
+
+  if ((tracing && disconnected_tracing) || any_persistent_commands ())
+    {
+      struct process_info *process = find_process_pid (pid);
+
+      if (process == NULL)
+	{
+	  write_enn (own_buf);
+	  return;
+	}
+
+      if (tracing && disconnected_tracing)
+	fprintf (stderr,
+		 "Disconnected tracing in effect, "
+		 "leaving gdbserver attached to the process\n");
+
+      if (any_persistent_commands ())
+	fprintf (stderr,
+		 "Persistent commands are present, "
+		 "leaving gdbserver attached to the process\n");
+
+      /* Make sure we're in non-stop/async mode, so we we can both
+	 wait for an async socket accept, and handle async target
+	 events simultaneously.  There's also no point either in
+	 having the target stop all threads, when we're going to
+	 pass signals down without informing GDB.  */
+      if (!non_stop)
+	{
+	  if (debug_threads)
+	    debug_printf ("Forcing non-stop mode\n");
+
+	  non_stop = 1;
+	  start_non_stop (1);
+	}
+
+      process->gdb_detached = 1;
+
+      /* Detaching implicitly resumes all threads.  */
+      target_continue_no_signal (minus_one_ptid);
+
+      write_ok (own_buf);
+      return;
+    }
+
+  fprintf (stderr, "Detaching from process %d\n", pid);
+  stop_tracing ();
+  if (detach_inferior (pid) != 0)
+    write_enn (own_buf);
+  else
+    {
+      discard_queued_stop_replies (pid_to_ptid (pid));
+      write_ok (own_buf);
+
+      if (extended_protocol || target_running ())
+	{
+	  /* There is still at least one inferior remaining or
+	     we are in extended mode, so don't terminate gdbserver,
+	     and instead treat this like a normal program exit.  */
+	  last_status.kind = TARGET_WAITKIND_EXITED;
+	  last_status.value.integer = 0;
+	  last_ptid = pid_to_ptid (pid);
+
+	  current_thread = NULL;
+	}
+      else
+	{
+	  putpkt (own_buf);
+	  remote_close ();
+
+	  /* If we are attached, then we can exit.  Otherwise, we
+	     need to hang around doing nothing, until the child is
+	     gone.  */
+	  join_inferior (pid);
+	  exit (0);
+	}
+    }
+}
+
 /* Parse options to --debug-format= and "monitor set debug-format".
    ARG is the text after "--debug-format=" or "monitor set debug-format".
    IS_MONITOR is non-zero if we're invoked via "monitor set debug-format".
@@ -4003,13 +4097,10 @@ process_point_options (struct gdb_breakpoint *bp, char **packet)
 static int
 process_serial_event (void)
 {
-  char ch;
-  int i = 0;
   int signal;
   unsigned int len;
   int res;
   CORE_ADDR mem_addr;
-  int pid;
   unsigned char sig;
   int packet_len;
   int new_packet_len = -1;
@@ -4026,8 +4117,7 @@ process_serial_event (void)
     }
   response_needed = 1;
 
-  i = 0;
-  ch = own_buf[i++];
+  char ch = own_buf[0];
   switch (ch)
     {
     case 'q':
@@ -4037,91 +4127,7 @@ process_serial_event (void)
       handle_general_set (own_buf);
       break;
     case 'D':
-      require_running_or_break (own_buf);
-
-      if (multi_process)
-	{
-	  i++; /* skip ';' */
-	  pid = strtol (&own_buf[i], NULL, 16);
-	}
-      else
-	pid = ptid_get_pid (current_ptid);
-
-      if ((tracing && disconnected_tracing) || any_persistent_commands ())
-	{
-	  struct process_info *process = find_process_pid (pid);
-
-	  if (process == NULL)
-	    {
-	      write_enn (own_buf);
-	      break;
-	    }
-
-	  if (tracing && disconnected_tracing)
-	    fprintf (stderr,
-		     "Disconnected tracing in effect, "
-		     "leaving gdbserver attached to the process\n");
-
-	  if (any_persistent_commands ())
-	    fprintf (stderr,
-		     "Persistent commands are present, "
-		     "leaving gdbserver attached to the process\n");
-
-	  /* Make sure we're in non-stop/async mode, so we we can both
-	     wait for an async socket accept, and handle async target
-	     events simultaneously.  There's also no point either in
-	     having the target stop all threads, when we're going to
-	     pass signals down without informing GDB.  */
-	  if (!non_stop)
-	    {
-	      if (debug_threads)
-		debug_printf ("Forcing non-stop mode\n");
-
-	      non_stop = 1;
-	      start_non_stop (1);
-	    }
-
-	  process->gdb_detached = 1;
-
-	  /* Detaching implicitly resumes all threads.  */
-	  target_continue_no_signal (minus_one_ptid);
-
-	  write_ok (own_buf);
-	  break; /* from switch/case */
-	}
-
-      fprintf (stderr, "Detaching from process %d\n", pid);
-      stop_tracing ();
-      if (detach_inferior (pid) != 0)
-	write_enn (own_buf);
-      else
-	{
-	  discard_queued_stop_replies (pid_to_ptid (pid));
-	  write_ok (own_buf);
-
-	  if (extended_protocol || target_running ())
-	    {
-	      /* There is still at least one inferior remaining or
-		 we are in extended mode, so don't terminate gdbserver,
-		 and instead treat this like a normal program exit.  */
-	      last_status.kind = TARGET_WAITKIND_EXITED;
-	      last_status.value.integer = 0;
-	      last_ptid = pid_to_ptid (pid);
-
-	      current_thread = NULL;
-	    }
-	  else
-	    {
-	      putpkt (own_buf);
-	      remote_close ();
-
-	      /* If we are attached, then we can exit.  Otherwise, we
-		 need to hang around doing nothing, until the child is
-		 gone.  */
-	      join_inferior (pid);
-	      exit (0);
-	    }
-	}
+      handle_detach (own_buf);
       break;
     case '!':
       extended_protocol = 1;