/* Command-line output logging for GDB, the GNU debugger.

   Copyright (C) 2003-2015 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 "gdbcmd.h"
#include "ui-out.h"
#include "interps.h"

/* These hold the pushed copies of the gdb output files.
   If NULL then nothing has yet been pushed.  */
struct saved_output_files
{
  struct ui_file *out;
  struct ui_file *err;
  struct ui_file *log;
  struct ui_file *targ;
  struct ui_file *targerr;
};
static struct saved_output_files saved_output;
static char *saved_filename;

static char *logging_filename;
static void
show_logging_filename (struct ui_file *file, int from_tty,
		       struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file, _("The current logfile is \"%s\".\n"),
		    value);
}

static int logging_overwrite;

static void
set_logging_overwrite (char *args, int from_tty, struct cmd_list_element *c)
{
  if (saved_filename)
    warning (_("Currently logging to %s.  Turn the logging off and on to "
	       "make the new setting effective."), saved_filename);
}

static void
show_logging_overwrite (struct ui_file *file, int from_tty,
			struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file,
		    _("Whether logging overwrites or "
		      "appends to the log file is %s.\n"),
		    value);
}

/* Value as configured by the user.  */
static int logging_redirect;

/* The on-disk file in use if logging is currently active together
   with redirection turned off (and therefore using tee_file_new).
   For active logging with redirection the on-disk file is directly in
   GDB_STDOUT and this variable is NULL.  */
static struct ui_file *logging_no_redirect_file;

static void
set_logging_redirect (char *args, int from_tty, struct cmd_list_element *c)
{
  struct cleanup *cleanups;
  struct ui_file *output, *new_logging_no_redirect_file;
  struct ui_out *uiout = current_uiout;

  if (saved_filename == NULL
      || (logging_redirect != 0 && logging_no_redirect_file == NULL)
      || (logging_redirect == 0 && logging_no_redirect_file != NULL))
    return;

  cleanups = make_cleanup (null_cleanup, NULL);

  if (logging_redirect != 0)
    {
      gdb_assert (logging_no_redirect_file != NULL);

      /* ui_out_redirect still has not been called for next
	 gdb_stdout.  */
      make_cleanup_ui_file_delete (gdb_stdout);

      output = logging_no_redirect_file;
      new_logging_no_redirect_file = NULL;

      if (from_tty)
	fprintf_unfiltered (saved_output.out, "Redirecting output to %s.\n",
			    logging_filename);
    }
  else
    {
      gdb_assert (logging_no_redirect_file == NULL);
      output = tee_file_new (saved_output.out, 0, gdb_stdout, 0);
      if (output == NULL)
	perror_with_name (_("set logging"));
      new_logging_no_redirect_file = gdb_stdout;

      if (from_tty)
	fprintf_unfiltered (saved_output.out, "Copying output to %s.\n",
			    logging_filename);
    }

  /* Give the current interpreter a chance to do anything special that
     it might need for logging, such as updating other channels.  */
  if (current_interp_set_logging (1, output, NULL) == 0)
    {
      gdb_stdout = output;
      gdb_stdlog = output;
      gdb_stderr = output;
      gdb_stdtarg = output;
      gdb_stdtargerr = output;
    }

  logging_no_redirect_file = new_logging_no_redirect_file;

  /* There is a former output pushed on the ui_out_redirect stack.  We
     want to replace it by OUTPUT so we must pop the former value
     first.  We should either do both the pop and push or to do
     neither of it.  At least do not try to push OUTPUT if the pop
     already failed.  */

  if (ui_out_redirect (uiout, NULL) < 0
      || ui_out_redirect (uiout, output) < 0)
    warning (_("Current output protocol does not support redirection"));

  do_cleanups (cleanups);
}

static void
show_logging_redirect (struct ui_file *file, int from_tty,
		       struct cmd_list_element *c, const char *value)
{
  fprintf_filtered (file, _("The logging output mode is %s.\n"), value);
}

/* If we've pushed output files, close them and pop them.  */
static void
pop_output_files (void)
{
  if (logging_no_redirect_file)
    {
      ui_file_delete (logging_no_redirect_file);
      logging_no_redirect_file = NULL;
    }

  if (current_interp_set_logging (0, NULL, NULL) == 0)
    {
      /* Only delete one of the files -- they are all set to the same
	 value.  */
      ui_file_delete (gdb_stdout);

      gdb_stdout = saved_output.out;
      gdb_stderr = saved_output.err;
      gdb_stdlog = saved_output.log;
      gdb_stdtarg = saved_output.targ;
      gdb_stdtargerr = saved_output.targerr;
    }

  saved_output.out = NULL;
  saved_output.err = NULL;
  saved_output.log = NULL;
  saved_output.targ = NULL;
  saved_output.targerr = NULL;

  ui_out_redirect (current_uiout, NULL);
}

/* This is a helper for the `set logging' command.  */
static void
handle_redirections (int from_tty)
{
  struct cleanup *cleanups;
  struct ui_file *output;
  struct ui_file *no_redirect_file = NULL;

  if (saved_filename != NULL)
    {
      fprintf_unfiltered (gdb_stdout, "Already logging to %s.\n",
			  saved_filename);
      return;
    }

  output = gdb_fopen (logging_filename, logging_overwrite ? "w" : "a");
  if (output == NULL)
    perror_with_name (_("set logging"));
  cleanups = make_cleanup_ui_file_delete (output);

  /* Redirects everything to gdb_stdout while this is running.  */
  if (!logging_redirect)
    {
      no_redirect_file = output;

      output = tee_file_new (gdb_stdout, 0, no_redirect_file, 0);
      if (output == NULL)
	perror_with_name (_("set logging"));
      make_cleanup_ui_file_delete (output);
      if (from_tty)
	fprintf_unfiltered (gdb_stdout, "Copying output to %s.\n",
			    logging_filename);
      logging_no_redirect_file = no_redirect_file;
    }
  else
    {
      gdb_assert (logging_no_redirect_file == NULL);

      if (from_tty)
	fprintf_unfiltered (gdb_stdout, "Redirecting output to %s.\n",
			    logging_filename);
    }

  discard_cleanups (cleanups);

  saved_filename = xstrdup (logging_filename);
  saved_output.out = gdb_stdout;
  saved_output.err = gdb_stderr;
  saved_output.log = gdb_stdlog;
  saved_output.targ = gdb_stdtarg;
  saved_output.targerr = gdb_stdtargerr;

  /* Let the interpreter do anything it needs.  */
  if (current_interp_set_logging (1, output, no_redirect_file) == 0)
    {
      gdb_stdout = output;
      gdb_stdlog = output;
      gdb_stderr = output;
      gdb_stdtarg = output;
      gdb_stdtargerr = output;
    }

  /* Don't do the redirect for MI, it confuses MI's ui-out scheme.  */
  if (!ui_out_is_mi_like_p (current_uiout))
    {
      if (ui_out_redirect (current_uiout, output) < 0)
	warning (_("Current output protocol does not support redirection"));
    }
}

static void
set_logging_on (char *args, int from_tty)
{
  char *rest = args;

  if (rest && *rest)
    {
      xfree (logging_filename);
      logging_filename = xstrdup (rest);
    }
  handle_redirections (from_tty);
}

static void 
set_logging_off (char *args, int from_tty)
{
  if (saved_filename == NULL)
    return;

  pop_output_files ();
  if (from_tty)
    fprintf_unfiltered (gdb_stdout, "Done logging to %s.\n", saved_filename);
  xfree (saved_filename);
  saved_filename = NULL;
}

static void
set_logging_command (char *args, int from_tty)
{
  printf_unfiltered (_("\"set logging\" lets you log output to a file.\n"
		       "Usage: set logging on [FILENAME]\n"
		       "       set logging off\n"
		       "       set logging file FILENAME\n"
		       "       set logging overwrite [on|off]\n"
		       "       set logging redirect [on|off]\n"));
}

static void
show_logging_command (char *args, int from_tty)
{
  if (saved_filename)
    printf_unfiltered (_("Currently logging to \"%s\".\n"), saved_filename);
  if (saved_filename == NULL
      || strcmp (logging_filename, saved_filename) != 0)
    printf_unfiltered (_("Future logs will be written to %s.\n"),
		       logging_filename);

  if (logging_overwrite)
    printf_unfiltered (_("Logs will overwrite the log file.\n"));
  else
    printf_unfiltered (_("Logs will be appended to the log file.\n"));

  if (saved_filename)
    {
      if (logging_redirect)
	printf_unfiltered (_("Output is being sent only to the log file.\n"));
      else
	printf_unfiltered (_("Output is being logged and displayed.\n"));
    }
  else
    {
      if (logging_redirect)
	printf_unfiltered (_("Output will be sent only to the log file.\n"));
      else
	printf_unfiltered (_("Output will be logged and displayed.\n"));
    }
}

/* Provide a prototype to silence -Wmissing-prototypes.  */
extern initialize_file_ftype _initialize_cli_logging;

void
_initialize_cli_logging (void)
{
  static struct cmd_list_element *set_logging_cmdlist, *show_logging_cmdlist;

  add_prefix_cmd ("logging", class_support, set_logging_command,
		  _("Set logging options"), &set_logging_cmdlist,
		  "set logging ", 0, &setlist);
  add_prefix_cmd ("logging", class_support, show_logging_command,
		  _("Show logging options"), &show_logging_cmdlist,
		  "show logging ", 0, &showlist);
  add_setshow_boolean_cmd ("overwrite", class_support, &logging_overwrite, _("\
Set whether logging overwrites or appends to the log file."), _("\
Show whether logging overwrites or appends to the log file."), _("\
If set, logging overrides the log file."),
			   set_logging_overwrite,
			   show_logging_overwrite,
			   &set_logging_cmdlist, &show_logging_cmdlist);
  add_setshow_boolean_cmd ("redirect", class_support, &logging_redirect, _("\
Set the logging output mode."), _("\
Show the logging output mode."), _("\
If redirect is off, output will go to both the screen and the log file.\n\
If redirect is on, output will go only to the log file."),
			   set_logging_redirect,
			   show_logging_redirect,
			   &set_logging_cmdlist, &show_logging_cmdlist);
  add_setshow_filename_cmd ("file", class_support, &logging_filename, _("\
Set the current logfile."), _("\
Show the current logfile."), _("\
The logfile is used when directing GDB's output."),
			    NULL,
			    show_logging_filename,
			    &set_logging_cmdlist, &show_logging_cmdlist);
  add_cmd ("on", class_support, set_logging_on,
	   _("Enable logging."), &set_logging_cmdlist);
  add_cmd ("off", class_support, set_logging_off,
	   _("Disable logging."), &set_logging_cmdlist);

  logging_filename = xstrdup ("gdb.txt");
}