/home/stan/gdb/src/gdb/serial.c

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/* Generic serial interface routines

   Copyright (C) 1992-2013 Free Software Foundation, Inc.

   This file is part of GDB.

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 3 of the License, or
   (at your option) any later version.

   This program is distributed in the hope that it will be useful,
   but WITHOUT ANY WARRANTY; without even the implied warranty of
   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
   GNU General Public License for more details.

   You should have received a copy of the GNU General Public License
   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */

#include "defs.h"
#include <ctype.h>
#include "serial.h"
#include "gdb_string.h"
#include "gdbcmd.h"
#include "cli/cli-utils.h"

extern void _initialize_serial (void);

/* Is serial being debugged?  */

static unsigned int global_serial_debug_p;

/* Linked list of serial I/O handlers.  */

static struct serial_ops *serial_ops_list = NULL;

/* Pointer to list of scb's.  */

static struct serial *scb_base;

/* Non-NULL gives filename which contains a recording of the remote session,
   suitable for playback by gdbserver.  */

static char *serial_logfile = NULL;
static struct ui_file *serial_logfp = NULL;

static struct serial_ops *serial_interface_lookup (const char *);
static void serial_logchar (struct ui_file *stream,
                            int ch_type, int ch, int timeout);
static const char logbase_hex[] = "hex";
static const char logbase_octal[] = "octal";
static const char logbase_ascii[] = "ascii";
static const char *const logbase_enums[] =
{logbase_hex, logbase_octal, logbase_ascii, NULL};
static const char *serial_logbase = logbase_ascii;


static int serial_current_type = 0;

/* Log char CH of type CHTYPE, with TIMEOUT.  */

/* Define bogus char to represent a BREAK.  Should be careful to choose a value
   that can't be confused with a normal char, or an error code.  */
#define SERIAL_BREAK 1235

static void
serial_logchar (struct ui_file *stream, int ch_type, int ch, int timeout)
{
  if (ch_type != serial_current_type)
    {
      fprintf_unfiltered (stream, "\n%c ", ch_type);
      serial_current_type = ch_type;
    }

  if (serial_logbase != logbase_ascii)
    fputc_unfiltered (' ', stream);

  switch (ch)
    {
    case SERIAL_TIMEOUT:
      fprintf_unfiltered (stream, "<Timeout: %d seconds>", timeout);
      return;
    case SERIAL_ERROR:
      fprintf_unfiltered (stream, "<Error: %s>", safe_strerror (errno));
      return;
    case SERIAL_EOF:
      fputs_unfiltered ("<Eof>", stream);
      return;
    case SERIAL_BREAK:
      fputs_unfiltered ("<Break>", stream);
      return;
    default:
      if (serial_logbase == logbase_hex)
        fprintf_unfiltered (stream, "%02x", ch & 0xff);
      else if (serial_logbase == logbase_octal)
        fprintf_unfiltered (stream, "%03o", ch & 0xff);
      else
        switch (ch)
          {
          case '\\':
            fputs_unfiltered ("\\\\", stream);
            break;
          case '\b':
            fputs_unfiltered ("\\b", stream);
            break;
          case '\f':
            fputs_unfiltered ("\\f", stream);
            break;
          case '\n':
            fputs_unfiltered ("\\n", stream);
            break;
          case '\r':
            fputs_unfiltered ("\\r", stream);
            break;
          case '\t':
            fputs_unfiltered ("\\t", stream);
            break;
          case '\v':
            fputs_unfiltered ("\\v", stream);
            break;
          default:
            fprintf_unfiltered (stream,
                                isprint (ch) ? "%c" : "\\x%02x", ch & 0xFF);
            break;
          }
    }
}

void
serial_log_command (const char *cmd)
{
  if (!serial_logfp)
    return;

  serial_current_type = 'c';

  fputs_unfiltered ("\nc ", serial_logfp);
  fputs_unfiltered (cmd, serial_logfp);

  /* Make sure that the log file is as up-to-date as possible,
     in case we are getting ready to dump core or something.  */
  gdb_flush (serial_logfp);
}


static struct serial_ops *
serial_interface_lookup (const char *name)
{
  struct serial_ops *ops;

  for (ops = serial_ops_list; ops; ops = ops->next)
    if (strcmp (name, ops->name) == 0)
      return ops;

  return NULL;
}

void
serial_add_interface (struct serial_ops *optable)
{
  optable->next = serial_ops_list;
  serial_ops_list = optable;
}

/* Return the open serial device for FD, if found, or NULL if FD is
   not already opened.  */

struct serial *
serial_for_fd (int fd)
{
  struct serial *scb;

  for (scb = scb_base; scb; scb = scb->next)
    if (scb->fd == fd)
      return scb;

  return NULL;
}

/* Open up a device or a network socket, depending upon the syntax of NAME.  */

struct serial *
serial_open (const char *name)
{
  struct serial *scb;
  struct serial_ops *ops;
  const char *open_name = name;

  if (strcmp (name, "pc") == 0)
    ops = serial_interface_lookup ("pc");
  else if (strncmp (name, "lpt", 3) == 0)
    ops = serial_interface_lookup ("parallel");
  else if (strncmp (name, "|", 1) == 0)
    {
      ops = serial_interface_lookup ("pipe");
      /* Discard ``|'' and any space before the command itself.  */
      ++open_name;
      open_name = skip_spaces_const (open_name);
    }
  /* Check for a colon, suggesting an IP address/port pair.
     Do this *after* checking for all the interesting prefixes.  We
     don't want to constrain the syntax of what can follow them.  */
  else if (strchr (name, ':'))
    ops = serial_interface_lookup ("tcp");
  else
    ops = serial_interface_lookup ("hardwire");

  if (!ops)
    return NULL;

  scb = XMALLOC (struct serial);

  scb->ops = ops;

  scb->bufcnt = 0;
  scb->bufp = scb->buf;
  scb->error_fd = -1;
  scb->refcnt = 1;

  /* `...->open (...)' would get expanded by the open(2) syscall macro.  */
  if ((*scb->ops->open) (scb, open_name))
    {
      xfree (scb);
      return NULL;
    }

  scb->name = xstrdup (name);
  scb->next = scb_base;
  scb->debug_p = 0;
  scb->async_state = 0;
  scb->async_handler = NULL;
  scb->async_context = NULL;
  scb_base = scb;

  if (serial_logfile != NULL)
    {
      serial_logfp = gdb_fopen (serial_logfile, "w");
      if (serial_logfp == NULL)
        perror_with_name (serial_logfile);
    }

  return scb;
}

/* Open a new serial stream using a file handle, using serial
   interface ops OPS.  */

static struct serial *
serial_fdopen_ops (const int fd, struct serial_ops *ops)
{
  struct serial *scb;

  if (!ops)
    {
      ops = serial_interface_lookup ("terminal");
      if (!ops)
        ops = serial_interface_lookup ("hardwire");
    }

  if (!ops)
    return NULL;

  scb = XCALLOC (1, struct serial);

  scb->ops = ops;

  scb->bufcnt = 0;
  scb->bufp = scb->buf;
  scb->error_fd = -1;
  scb->refcnt = 1;

  scb->name = NULL;
  scb->next = scb_base;
  scb->debug_p = 0;
  scb->async_state = 0;
  scb->async_handler = NULL;
  scb->async_context = NULL;
  scb_base = scb;

  if ((ops->fdopen) != NULL)
    (*ops->fdopen) (scb, fd);
  else
    scb->fd = fd;

  return scb;
}

struct serial *
serial_fdopen (const int fd)
{
  return serial_fdopen_ops (fd, NULL);
}

static void
do_serial_close (struct serial *scb, int really_close)
{
  struct serial *tmp_scb;

  if (serial_logfp)
    {
      fputs_unfiltered ("\nEnd of log\n", serial_logfp);
      serial_current_type = 0;

      /* XXX - What if serial_logfp == gdb_stdout or gdb_stderr?  */
      ui_file_delete (serial_logfp);
      serial_logfp = NULL;
    }

  /* ensure that the FD has been taken out of async mode.  */
  if (scb->async_handler != NULL)
    serial_async (scb, NULL, NULL);

  if (really_close)
    scb->ops->close (scb);

  if (scb->name)
    xfree (scb->name);

  /* For serial_is_open.  */
  scb->bufp = NULL;

  if (scb_base == scb)
    scb_base = scb_base->next;
  else
    for (tmp_scb = scb_base; tmp_scb; tmp_scb = tmp_scb->next)
      {
        if (tmp_scb->next != scb)
          continue;

        tmp_scb->next = tmp_scb->next->next;
        break;
      }

  serial_unref (scb);
}

void
serial_close (struct serial *scb)
{
  do_serial_close (scb, 1);
}

void
serial_un_fdopen (struct serial *scb)
{
  do_serial_close (scb, 0);
}

int
serial_is_open (struct serial *scb)
{
  return scb->bufp != NULL;
}

void
serial_ref (struct serial *scb)
{
  scb->refcnt++;
}

void
serial_unref (struct serial *scb)
{
  --scb->refcnt;
  if (scb->refcnt == 0)
    xfree (scb);
}

int
serial_readchar (struct serial *scb, int timeout)
{
  int ch;

  /* FIXME: cagney/1999-10-11: Don't enable this check until the ASYNC
     code is finished.  */
  if (0 && serial_is_async_p (scb) && timeout < 0)
    internal_error (__FILE__, __LINE__,
                    _("serial_readchar: blocking read in async mode"));

  ch = scb->ops->readchar (scb, timeout);
  if (serial_logfp != NULL)
    {
      serial_logchar (serial_logfp, 'r', ch, timeout);

      /* Make sure that the log file is as up-to-date as possible,
         in case we are getting ready to dump core or something.  */
      gdb_flush (serial_logfp);
    }
  if (serial_debug_p (scb))
    {
      fprintf_unfiltered (gdb_stdlog, "[");
      serial_logchar (gdb_stdlog, 'r', ch, timeout);
      fprintf_unfiltered (gdb_stdlog, "]");
      gdb_flush (gdb_stdlog);
    }

  return (ch);
}

int
serial_write (struct serial *scb, const void *buf, size_t count)
{
  if (serial_logfp != NULL)
    {
      const char *str = buf;
      size_t c;

      for (c = 0; c < count; c++)
        serial_logchar (serial_logfp, 'w', str[c] & 0xff, 0);

      /* Make sure that the log file is as up-to-date as possible,
         in case we are getting ready to dump core or something.  */
      gdb_flush (serial_logfp);
    }
  if (serial_debug_p (scb))
    {
      const char *str = buf;
      size_t c;

      for (c = 0; c < count; c++)
        {
          fprintf_unfiltered (gdb_stdlog, "[");
          serial_logchar (gdb_stdlog, 'w', str[count] & 0xff, 0);
          fprintf_unfiltered (gdb_stdlog, "]");
        }
      gdb_flush (gdb_stdlog);
    }

  return (scb->ops->write (scb, buf, count));
}

void
serial_printf (struct serial *desc, const char *format,...)
{
  va_list args;
  char *buf;
  va_start (args, format);

  buf = xstrvprintf (format, args);
  serial_write (desc, buf, strlen (buf));

  xfree (buf);
  va_end (args);
}

int
serial_drain_output (struct serial *scb)
{
  return scb->ops->drain_output (scb);
}

int
serial_flush_output (struct serial *scb)
{
  return scb->ops->flush_output (scb);
}

int
serial_flush_input (struct serial *scb)
{
  return scb->ops->flush_input (scb);
}

int
serial_send_break (struct serial *scb)
{
  if (serial_logfp != NULL)
    serial_logchar (serial_logfp, 'w', SERIAL_BREAK, 0);

  return (scb->ops->send_break (scb));
}

void
serial_raw (struct serial *scb)
{
  scb->ops->go_raw (scb);
}

serial_ttystate
serial_get_tty_state (struct serial *scb)
{
  return scb->ops->get_tty_state (scb);
}

serial_ttystate
serial_copy_tty_state (struct serial *scb, serial_ttystate ttystate)
{
  return scb->ops->copy_tty_state (scb, ttystate);
}

int
serial_set_tty_state (struct serial *scb, serial_ttystate ttystate)
{
  return scb->ops->set_tty_state (scb, ttystate);
}

void
serial_print_tty_state (struct serial *scb,
                        serial_ttystate ttystate,
                        struct ui_file *stream)
{
  scb->ops->print_tty_state (scb, ttystate, stream);
}

int
serial_noflush_set_tty_state (struct serial *scb,
                              serial_ttystate new_ttystate,
                              serial_ttystate old_ttystate)
{
  return scb->ops->noflush_set_tty_state (scb, new_ttystate, old_ttystate);
}

int
serial_setbaudrate (struct serial *scb, int rate)
{
  return scb->ops->setbaudrate (scb, rate);
}

int
serial_setstopbits (struct serial *scb, int num)
{
  return scb->ops->setstopbits (scb, num);
}

int
serial_can_async_p (struct serial *scb)
{
  return (scb->ops->async != NULL);
}

int
serial_is_async_p (struct serial *scb)
{
  return (scb->ops->async != NULL) && (scb->async_handler != NULL);
}

void
serial_async (struct serial *scb,
              serial_event_ftype *handler,
              void *context)
{
  int changed = ((scb->async_handler == NULL) != (handler == NULL));

  scb->async_handler = handler;
  scb->async_context = context;
  /* Only change mode if there is a need.  */
  if (changed)
    scb->ops->async (scb, handler != NULL);
}

void
serial_debug (struct serial *scb, int debug_p)
{
  scb->debug_p = debug_p;
}

int
serial_debug_p (struct serial *scb)
{
  return scb->debug_p || global_serial_debug_p;
}

#ifdef USE_WIN32API
void
serial_wait_handle (struct serial *scb, HANDLE *read, HANDLE *except)
{
  if (scb->ops->wait_handle)
    scb->ops->wait_handle (scb, read, except);
  else
    {
      *read = (HANDLE) _get_osfhandle (scb->fd);
      *except = NULL;
    }
}

void
serial_done_wait_handle (struct serial *scb)
{
  if (scb->ops->done_wait_handle)
    scb->ops->done_wait_handle (scb);
}
#endif

int
serial_pipe (struct serial *scbs[2])
{
  struct serial_ops *ops;
  int fildes[2];

  ops = serial_interface_lookup ("pipe");
  if (!ops)
    {
      errno = ENOSYS;
      return -1;
    }

  if (gdb_pipe (fildes) == -1)
    return -1;

  scbs[0] = serial_fdopen_ops (fildes[0], ops);
  scbs[1] = serial_fdopen_ops (fildes[1], ops);
  return 0;
}

/* Serial set/show framework.  */

static struct cmd_list_element *serial_set_cmdlist;
static struct cmd_list_element *serial_show_cmdlist;

static void
serial_set_cmd (char *args, int from_tty)
{
  printf_unfiltered ("\"set serial\" must be followed "
                     "by the name of a command.\n");
  help_list (serial_set_cmdlist, "set serial ", -1, gdb_stdout);
}

static void
serial_show_cmd (char *args, int from_tty)
{
  cmd_show_list (serial_show_cmdlist, from_tty, "");
}

/* Baud rate specified for talking to serial target systems.  Default
   is left as -1, so targets can choose their own defaults.  */
/* FIXME: This means that "show serial baud" and gr_files_info can
   print -1 or (unsigned int)-1.  This is a Bad User Interface.  */

int baud_rate = -1;

static void
serial_baud_show_cmd (struct ui_file *file, int from_tty,
                      struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file, _("Baud rate for remote serial I/O is %s.\n"),
                    value);
}

void
_initialize_serial (void)
{
#if 0
  add_com ("connect", class_obscure, connect_command, _("\
Connect the terminal directly up to the command monitor.\n\
Use <CR>~. or <CR>~^D to break out."));
#endif /* 0 */

  add_prefix_cmd ("serial", class_maintenance, serial_set_cmd, _("\
Set default serial/parallel port configuration."),
                  &serial_set_cmdlist, "set serial ",
                  0/*allow-unknown*/,
                  &setlist);

  add_prefix_cmd ("serial", class_maintenance, serial_show_cmd, _("\
Show default serial/parallel port configuration."),
                  &serial_show_cmdlist, "show serial ",
                  0/*allow-unknown*/,
                  &showlist);

  /* If target is open when baud changes, it doesn't take effect until
     the next open (I think, not sure).  */
  add_setshow_zinteger_cmd ("baud", no_class, &baud_rate, _("\
Set baud rate for remote serial I/O."), _("\
Show baud rate for remote serial I/O."), _("\
This value is used to set the speed of the serial port when debugging\n\
using remote targets."),
                            NULL,
                            serial_baud_show_cmd,
                            &serial_set_cmdlist, &serial_show_cmdlist);

  /* The commands "set/show serial baud" used to have a different name.
     Add aliases to those names to facilitate the transition, and mark
     them as deprecated, in order to make users aware of the fact that
     the command names have been changed.  */
    {
      const char *cmd_name;
      struct cmd_list_element *cmd;

      /* FIXME: There is a limitation in the deprecation mechanism,
         and the warning ends up not being displayed for prefixed
         aliases.  So use a real command instead of an alias.  */
      add_setshow_zinteger_cmd ("remotebaud", class_alias, &baud_rate, _("\
Set baud rate for remote serial I/O."), _("\
Show baud rate for remote serial I/O."), _("\
This value is used to set the speed of the serial port when debugging\n\
using remote targets."),
                                NULL,
                                serial_baud_show_cmd,
                                &setlist, &showlist);
      cmd_name = "remotebaud";
      cmd = lookup_cmd (&cmd_name, setlist, "", -1, 1);
      deprecate_cmd (cmd, "set serial baud");
      cmd_name
        = "remotebaud"; /* needed because lookup_cmd updates the pointer */
      cmd = lookup_cmd (&cmd_name, showlist, "", -1, 1);
      deprecate_cmd (cmd, "show serial baud");
    }

  add_setshow_filename_cmd ("remotelogfile", no_class, &serial_logfile, _("\
Set filename for remote session recording."), _("\
Show filename for remote session recording."), _("\
This file is used to record the remote session for future playback\n\
by gdbserver."),
                            NULL,
                            NULL, /* FIXME: i18n: */
                            &setlist, &showlist);

  add_setshow_enum_cmd ("remotelogbase", no_class, logbase_enums,
                        &serial_logbase, _("\
Set numerical base for remote session logging"), _("\
Show numerical base for remote session logging"), NULL,
                        NULL,
                        NULL, /* FIXME: i18n: */
                        &setlist, &showlist);

  add_setshow_zuinteger_cmd ("serial", class_maintenance,
                             &global_serial_debug_p, _("\
Set serial debugging."), _("\
Show serial debugging."), _("\
When non-zero, serial port debugging is enabled."),
                             NULL,
                             NULL, /* FIXME: i18n: */
                             &setdebuglist, &showdebuglist);
}