[4/6] Change serial "open" functions to throw exception

diff --git a/gdb/remote.c b/gdb/remote.c
index 9346ae8b3a1..646f869ef3a 100644
--- a/gdb/remote.c
+++ b/gdb/remote.c
@@ -5954,8 +5954,6 @@  remote_target::open_1 (const char *name, int from_tty, int extended_p)
     rs->wait_forever_enabled_p = true;
 
   rs->remote_desc = remote_serial_open (name);
-  if (!rs->remote_desc)
-    perror_with_name (name);
 
   if (baud_rate != -1)
     {
diff --git a/gdb/ser-event.c b/gdb/ser-event.c
index 5865e847bb5..fb02327492a 100644
--- a/gdb/ser-event.c
+++ b/gdb/ser-event.c
@@ -48,7 +48,7 @@  struct serial_event_state
 
 /* Open a new serial event.  */
 
-static int
+static void
 serial_event_open (struct serial *scb, const char *name)
 {
   struct serial_event_state *state;
@@ -85,8 +85,6 @@  serial_event_open (struct serial *scb, const char *name)
     scb->fd = _open_osfhandle ((intptr_t) dummy_file, 0);
   }
 #endif
-
-  return 0;
 }
 
 static void
diff --git a/gdb/ser-mingw.c b/gdb/ser-mingw.c
index 65ee1697331..30d908576da 100644
--- a/gdb/ser-mingw.c
+++ b/gdb/ser-mingw.c
@@ -48,7 +48,7 @@  static CancelIo_ftype *CancelIo;
 
 /* Open up a real live device for serial I/O.  */
 
-static int
+static void
 ser_windows_open (struct serial *scb, const char *name)
 {
   HANDLE h;
@@ -59,22 +59,18 @@  ser_windows_open (struct serial *scb, const char *name)
 		  OPEN_EXISTING, FILE_FLAG_OVERLAPPED, NULL);
   if (h == INVALID_HANDLE_VALUE)
     {
-      errno = ENOENT;
-      return -1;
+      std::string msg = string_printf(_("could not open file: %s"),
+				      name);
+      throw_winerror_with_name (msg.c_str (), GetLastError ());
     }
 
   scb->fd = _open_osfhandle ((intptr_t) h, O_RDWR);
   if (scb->fd < 0)
-    {
-      errno = ENOENT;
-      return -1;
-    }
+    error (_("could not get underlying file descriptor"));
 
   if (!SetCommMask (h, EV_RXCHAR))
-    {
-      errno = EINVAL;
-      return -1;
-    }
+    throw_winerror_with_name (_("error calling SetCommMask"),
+			      GetLastError ());
 
   timeouts.ReadIntervalTimeout = MAXDWORD;
   timeouts.ReadTotalTimeoutConstant = 0;
@@ -82,10 +78,8 @@  ser_windows_open (struct serial *scb, const char *name)
   timeouts.WriteTotalTimeoutConstant = 0;
   timeouts.WriteTotalTimeoutMultiplier = 0;
   if (!SetCommTimeouts (h, &timeouts))
-    {
-      errno = EINVAL;
-      return -1;
-    }
+    throw_winerror_with_name (_("error calling SetCommTimeouts"),
+			      GetLastError ());
 
   state = XCNEW (struct ser_windows_state);
   scb->state = state;
@@ -95,8 +89,6 @@  ser_windows_open (struct serial *scb, const char *name)
 
   /* Create a (currently unused) handle to record exceptions.  */
   state->except_event = CreateEvent (0, TRUE, FALSE, 0);
-
-  return 0;
 }
 
 /* Wait for the output to drain away, as opposed to flushing (discarding)
@@ -860,7 +852,7 @@  struct pipe_state_destroyer
 
 typedef std::unique_ptr<pipe_state, pipe_state_destroyer> pipe_state_up;
 
-static int
+static void
 pipe_windows_open (struct serial *scb, const char *name)
 {
   FILE *pex_stderr;
@@ -883,10 +875,10 @@  pipe_windows_open (struct serial *scb, const char *name)
 
   ps->pex = pex_init (PEX_USE_PIPES, "target remote pipe", NULL);
   if (! ps->pex)
-    return -1;
+    error (_("could not start pipeline"));
   ps->input = pex_input_pipe (ps->pex, 1);
   if (! ps->input)
-    return -1;
+    error (_("could not find input pipe"));
 
   {
     int err;
@@ -913,17 +905,15 @@  pipe_windows_open (struct serial *scb, const char *name)
 
   ps->output = pex_read_output (ps->pex, 1);
   if (! ps->output)
-    return -1;
+    error (_("could not find output pipe"));
   scb->fd = fileno (ps->output);
 
   pex_stderr = pex_read_err (ps->pex, 1);
   if (! pex_stderr)
-    return -1;
+    error (_("could not find error pipe"));
   scb->error_fd = fileno (pex_stderr);
 
   scb->state = ps.release ();
-
-  return 0;
 }
 
 static int
@@ -1191,15 +1181,12 @@  net_windows_done_wait_handle (struct serial *scb)
   stop_select_thread (&state->base);
 }
 
-static int
+static void
 net_windows_open (struct serial *scb, const char *name)
 {
   struct net_windows_state *state;
-  int ret;
 
-  ret = net_open (scb, name);
-  if (ret != 0)
-    return ret;
+  net_open (scb, name);
 
   state = XCNEW (struct net_windows_state);
   scb->state = state;
@@ -1210,8 +1197,6 @@  net_windows_open (struct serial *scb, const char *name)
 
   /* Start the thread.  */
   create_select_thread (net_windows_select_thread, scb, &state->base);
-
-  return 0;
 }
 
 
diff --git a/gdb/ser-pipe.c b/gdb/ser-pipe.c
index 47ccd33cece..7bdaaa071dc 100644
--- a/gdb/ser-pipe.c
+++ b/gdb/ser-pipe.c
@@ -34,7 +34,6 @@ 
 
 #include <signal.h>
 
-static int pipe_open (struct serial *scb, const char *name);
 static void pipe_close (struct serial *scb);
 
 struct pipe_state
@@ -44,7 +43,7 @@  struct pipe_state
 
 /* Open up a raw pipe.  */
 
-static int
+static void
 pipe_open (struct serial *scb, const char *name)
 {
 #if !HAVE_SOCKETPAIR
@@ -69,12 +68,13 @@  pipe_open (struct serial *scb, const char *name)
     }
 
   if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, pdes) < 0)
-    return -1;
+    perror_with_name (_("could not open socket pair"));
   if (gdb_socketpair_cloexec (AF_UNIX, SOCK_STREAM, 0, err_pdes) < 0)
     {
+      int save = errno;
       close (pdes[0]);
       close (pdes[1]);
-      return -1;
+      perror_with_name (_("could not open socket pair"), save);
     }
 
   /* Create the child process to run the command in.  Note that the
@@ -86,11 +86,12 @@  pipe_open (struct serial *scb, const char *name)
   /* Error.  */
   if (pid == -1)
     {
+      int save = errno;
       close (pdes[0]);
       close (pdes[1]);
       close (err_pdes[0]);
       close (err_pdes[1]);
-      return -1;
+      perror_with_name (_("could not vfork"), save);
     }
 
   if (fcntl (err_pdes[0], F_SETFL, O_NONBLOCK) == -1)
@@ -148,7 +149,6 @@  pipe_open (struct serial *scb, const char *name)
 
   /* If we don't do this, GDB simply exits when the remote side dies.  */
   signal (SIGPIPE, SIG_IGN);
-  return 0;
 #endif
 }
 
diff --git a/gdb/ser-tcp.c b/gdb/ser-tcp.c
index 6083bd61e62..75ea4c80051 100644
--- a/gdb/ser-tcp.c
+++ b/gdb/ser-tcp.c
@@ -84,11 +84,11 @@  static unsigned int tcp_retry_limit = 15;
 
 /* Helper function to wait a while.  If SOCK is not -1, wait on its
    file descriptor.  Otherwise just wait on a timeout, updating
-   *POLLS.  Returns -1 on timeout or interrupt, otherwise the value of
-   select.  */
+   *POLLS.  Returns -1 on timeout or interrupt and set OUT_ERROR,
+   otherwise the value of select.  */
 
 static int
-wait_for_connect (int sock, unsigned int *polls)
+wait_for_connect (int sock, unsigned int *polls, ULONGEST *out_error)
 {
   struct timeval t;
   int n;
@@ -98,14 +98,14 @@  wait_for_connect (int sock, unsigned int *polls)
      interrupt.  */
   if (deprecated_ui_loop_hook && deprecated_ui_loop_hook (0))
     {
-      errno = EINTR;
+      *out_error = EINTR;
       return -1;
     }
 
   /* Check for timeout.  */
   if (*polls > tcp_retry_limit * POLL_INTERVAL)
     {
-      errno = ETIMEDOUT;
+      *out_error = ETIMEDOUT;
       return -1;
     }
 
@@ -155,19 +155,34 @@  wait_for_connect (int sock, unsigned int *polls)
   return n;
 }
 
+/* A helper to get the error number for either Windows or POSIX.  */
+static ULONGEST
+get_error ()
+{
+#ifdef USE_WIN32API
+  return WSAGetLastError ();
+#else
+  return errno;
+#endif
+}
+
 /* Try to connect to the host represented by AINFO.  If the connection
-   succeeds, return its socket.  Otherwise, return -1 and set ERRNO
+   succeeds, return its socket.  Otherwise, return -1 and set OUT_ERROR
    accordingly.  POLLS is used when 'connect' returns EINPROGRESS, and
    we need to invoke 'wait_for_connect' to obtain the status.  */
 
 static int
-try_connect (const struct addrinfo *ainfo, unsigned int *polls)
+try_connect (const struct addrinfo *ainfo, unsigned int *polls,
+	     ULONGEST *out_error)
 {
   int sock = gdb_socket_cloexec (ainfo->ai_family, ainfo->ai_socktype,
 				 ainfo->ai_protocol);
 
   if (sock < 0)
-    return -1;
+    {
+      *out_error = get_error ();
+      return -1;
+    }
 
   /* Set socket nonblocking.  */
 #ifdef USE_WIN32API
@@ -182,11 +197,7 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
      already.  */
   if (connect (sock, ainfo->ai_addr, ainfo->ai_addrlen) < 0)
     {
-#ifdef USE_WIN32API
-      int err = WSAGetLastError();
-#else
-      int err = errno;
-#endif
+      ULONGEST err = get_error ();
 
       /* If we've got a "connection refused" error, just return
 	 -1.  The caller will know what to do.  */
@@ -199,7 +210,7 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
 	  )
 	{
 	  close (sock);
-	  errno = err;
+	  *out_error = err;
 	  return -1;
 	}
 
@@ -218,7 +229,7 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
 	  )
 	{
 	  close (sock);
-	  errno = err;
+	  *out_error = err;
 	  return -1;
 	}
 
@@ -226,17 +237,15 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
       int n;
 
       do
-	n = wait_for_connect (sock, polls);
+	n = wait_for_connect (sock, polls, out_error);
       while (n == 0);
 
       if (n < 0)
 	{
-	  int saved_errno = errno;
-
 	  /* A negative value here means that we either timed out or
 	     got interrupted by the user.  Just return.  */
 	  close (sock);
-	  errno = saved_errno;
+	  /* OUT_ERROR was set by wait_for_connect, above.  */
 	  return -1;
 	}
     }
@@ -253,16 +262,14 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
 
   if (ret < 0)
     {
-      int saved_errno = errno;
-
+      *out_error = get_error ();
       close (sock);
-      errno = saved_errno;
       return -1;
     }
   else if (ret == 0 && err != 0)
     {
+      *out_error = err;
       close (sock);
-      errno = err;
       return -1;
     }
 
@@ -272,7 +279,7 @@  try_connect (const struct addrinfo *ainfo, unsigned int *polls)
 
 /* Open a tcp socket.  */
 
-int
+void
 net_open (struct serial *scb, const char *name)
 {
   struct addrinfo hint;
@@ -295,12 +302,7 @@  net_open (struct serial *scb, const char *name)
 		       &hint, &ainfo);
 
   if (r != 0)
-    {
-      gdb_printf (gdb_stderr, _("%s: cannot resolve name: %s\n"),
-		  name, gai_strerror (r));
-      errno = ENOENT;
-      return -1;
-    }
+    error (_("%s: cannot resolve name: %s\n"), name, gai_strerror (r));
 
   scoped_free_addrinfo free_ainfo (ainfo);
 
@@ -311,6 +313,7 @@  net_open (struct serial *scb, const char *name)
      'struct addrinfo' that succeed.  */
   struct addrinfo *success_ainfo = NULL;
   unsigned int polls = 0;
+  ULONGEST last_error = 0;
 
   /* Assume the worst.  */
   scb->fd = -1;
@@ -324,7 +327,7 @@  net_open (struct serial *scb, const char *name)
 	  /* Iterate over the list of possible addresses to connect
 	     to.  For each, we'll try to connect and see if it
 	     succeeds.  */
-	  int sock = try_connect (iter, &polls);
+	  int sock = try_connect (iter, &polls, &last_error);
 
 	  if (sock >= 0)
 	    {
@@ -336,9 +339,9 @@  net_open (struct serial *scb, const char *name)
 	    }
 	  else if (
 #ifdef USE_WIN32API
-	  errno == WSAECONNREFUSED
+		   last_error == WSAECONNREFUSED
 #else
-	  errno == ECONNREFUSED
+		   last_error == ECONNREFUSED
 #endif
 		   )
 	    got_connrefused = true;
@@ -353,12 +356,16 @@  net_open (struct serial *scb, const char *name)
   while (tcp_auto_retry
 	 && success_ainfo == NULL
 	 && got_connrefused
-	 && wait_for_connect (-1, &polls) >= 0);
+	 && wait_for_connect (-1, &polls, &last_error) >= 0);
 
   if (success_ainfo == NULL)
     {
       net_close (scb);
-      return -1;
+#ifdef USE_WIN32API
+      throw_winerror_with_name (_("could not connect"), last_error);
+#else
+      perror_with_name (_("could not connect"), last_error);
+#endif
     }
 
   /* Turn off nonblocking.  */
@@ -384,8 +391,6 @@  net_open (struct serial *scb, const char *name)
      when the remote side dies.  */
   signal (SIGPIPE, SIG_IGN);
 #endif
-
-  return 0;
 }
 
 void
diff --git a/gdb/ser-tcp.h b/gdb/ser-tcp.h
index aeb4de04a3b..444d77c0b74 100644
--- a/gdb/ser-tcp.h
+++ b/gdb/ser-tcp.h
@@ -22,7 +22,7 @@ 
 
 struct serial;
 
-extern int net_open (struct serial *scb, const char *name);
+extern void net_open (struct serial *scb, const char *name);
 extern void net_close (struct serial *scb);
 extern int net_read_prim (struct serial *scb, size_t count);
 extern int net_write_prim (struct serial *scb, const void *buf, size_t count);
diff --git a/gdb/ser-uds.c b/gdb/ser-uds.c
index 665aab912da..e51058b534c 100644
--- a/gdb/ser-uds.c
+++ b/gdb/ser-uds.c
@@ -30,36 +30,30 @@ 
 
 /* Open an AF_UNIX socket.  */
 
-static int
+static void
 uds_open (struct serial *scb, const char *name)
 {
   struct sockaddr_un addr;
 
   if (strlen (name) > UNIX_PATH_MAX - 1)
-    {
-      warning
-	(_("The socket name is too long.  It may be no longer than %s bytes."),
-	 pulongest (UNIX_PATH_MAX - 1L));
-      return -1;
-    }
+    error (_("The socket name is too long.  It may be no longer than %s bytes."),
+	   pulongest (UNIX_PATH_MAX - 1L));
 
   memset (&addr, 0, sizeof addr);
   addr.sun_family = AF_UNIX;
   strncpy (addr.sun_path, name, UNIX_PATH_MAX - 1);
 
-  int sock = socket (AF_UNIX, SOCK_STREAM, 0);
+  scb->fd = socket (AF_UNIX, SOCK_STREAM, 0);
+  if (scb->fd < 0)
+    perror_with_name (_("could not open socket"));
 
-  if (connect (sock, (struct sockaddr *) &addr,
+  if (connect (scb->fd, (struct sockaddr *) &addr,
 	       sizeof (struct sockaddr_un)) < 0)
     {
-      close (sock);
-      scb->fd = -1;
-      return -1;
+      int saved = errno;
+      close (scb->fd);
+      perror_with_name (_("could not connect to remote"), saved);
     }
-
-  scb->fd = sock;
-
-  return 0;
 }
 
 static void
diff --git a/gdb/ser-unix.c b/gdb/ser-unix.c
index 5bd15985d8c..020b41e563d 100644
--- a/gdb/ser-unix.c
+++ b/gdb/ser-unix.c
@@ -50,7 +50,6 @@  show_serial_hwflow (struct ui_file *file, int from_tty,
 }
 #endif
 
-static int hardwire_open (struct serial *scb, const char *name);
 static void hardwire_raw (struct serial *scb);
 static int rate_to_code (int rate);
 static void hardwire_setbaudrate (struct serial *scb, int rate);
@@ -72,14 +71,12 @@  static int hardwire_setstopbits (struct serial *, int);
 
 /* Open up a real live device for serial I/O.  */
 
-static int
+static void
 hardwire_open (struct serial *scb, const char *name)
 {
   scb->fd = gdb_open_cloexec (name, O_RDWR, 0).release ();
   if (scb->fd < 0)
-    return -1;
-
-  return 0;
+    perror_with_name ("could not open device");
 }
 
 static int
diff --git a/gdb/serial.c b/gdb/serial.c
index 122ab0bd10e..720af1a356d 100644
--- a/gdb/serial.c
+++ b/gdb/serial.c
@@ -173,12 +173,10 @@  serial_for_fd (int fd)
 
 /* Create a new serial for OPS.  */
 
-static struct serial *
+static gdb::unique_xmalloc_ptr<struct serial>
 new_serial (const struct serial_ops *ops)
 {
-  struct serial *scb;
-
-  scb = XCNEW (struct serial);
+  gdb::unique_xmalloc_ptr<struct serial> scb (XCNEW (struct serial));
 
   scb->ops = ops;
 
@@ -221,7 +219,7 @@  serial_open (const char *name)
     }
 
   if (!ops)
-    return NULL;
+    error (_("could not find serial handler for '%s'"), name);
 
   return serial_open_ops_1 (ops, open_name);
 }
@@ -231,20 +229,14 @@  serial_open (const char *name)
 static struct serial *
 serial_open_ops_1 (const struct serial_ops *ops, const char *open_name)
 {
-  struct serial *scb;
-
-  scb = new_serial (ops);
+  gdb::unique_xmalloc_ptr<struct serial> scb = new_serial (ops);
 
   /* `...->open (...)' would get expanded by the open(2) syscall macro.  */
-  if ((*scb->ops->open) (scb, open_name))
-    {
-      xfree (scb);
-      return NULL;
-    }
+  (*scb->ops->open) (scb.get (), open_name);
 
   scb->name = open_name != NULL ? xstrdup (open_name) : NULL;
   scb->next = scb_base;
-  scb_base = scb;
+  scb_base = scb.get ();
 
   if (!serial_logfile.empty ())
     {
@@ -256,7 +248,7 @@  serial_open_ops_1 (const struct serial_ops *ops, const char *open_name)
       serial_logfp = file.release ();
     }
 
-  return scb;
+  return scb.release ();
 }
 
 /* See serial.h.  */
@@ -273,8 +265,6 @@  serial_open_ops (const struct serial_ops *ops)
 static struct serial *
 serial_fdopen_ops (const int fd, const struct serial_ops *ops)
 {
-  struct serial *scb;
-
   if (!ops)
     {
       ops = serial_interface_lookup ("terminal");
@@ -285,18 +275,18 @@  serial_fdopen_ops (const int fd, const struct serial_ops *ops)
   if (!ops)
     return NULL;
 
-  scb = new_serial (ops);
+  gdb::unique_xmalloc_ptr<struct serial> scb = new_serial (ops);
 
   scb->name = NULL;
   scb->next = scb_base;
-  scb_base = scb;
+  scb_base = scb.get ();
 
   if ((ops->fdopen) != NULL)
-    (*ops->fdopen) (scb, fd);
+    (*ops->fdopen) (scb.get (), fd);
   else
     scb->fd = fd;
 
-  return scb;
+  return scb.release ();
 }
 
 struct serial *
diff --git a/gdb/serial.h b/gdb/serial.h
index 9a51fdf7816..9ae7f4f13f1 100644
--- a/gdb/serial.h
+++ b/gdb/serial.h
@@ -259,7 +259,7 @@  struct serial
 struct serial_ops
   {
     const char *name;
-    int (*open) (struct serial *, const char *name);
+    void (*open) (struct serial *, const char *name);
     void (*close) (struct serial *);
     int (*fdopen) (struct serial *, int fd);
     int (*readchar) (struct serial *, int timeout);