gdb/tui/tui-interp.c

   1 /* TUI Interpreter definitions for GDB, the GNU debugger.
   2
   3    Copyright (C) 2003, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
   4
   5    This file is part of GDB.
   6
   7    This program is free software; you can redistribute it and/or modify
   8    it under the terms of the GNU General Public License as published by
   9    the Free Software Foundation; either version 3 of the License, or
  10    (at your option) any later version.
  11
  12    This program is distributed in the hope that it will be useful,
  13    but WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15    GNU General Public License for more details.
  16
  17    You should have received a copy of the GNU General Public License
  18    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 #include "defs.h"
  21 #include "interps.h"
  22 #include "top.h"
  23 #include "event-top.h"
  24 #include "event-loop.h"
  25 #include "ui-out.h"
  26 #include "cli-out.h"
  27 #include "tui/tui-data.h"
  28 #include "readline/readline.h"
  29 #include "tui/tui-win.h"
  30 #include "tui/tui.h"
  31 #include "tui/tui-io.h"
  32 #include "exceptions.h"
  33
  34 /* Set to 1 when the TUI mode must be activated when we first start
  35    gdb.  */
  36 static int tui_start_enabled = 0;
  37
  38 /* Cleanup the tui before exiting.  */
  39
  40 static void
  41 tui_exit (void)
  42 {
  43   /* Disable the tui.  Curses mode is left leaving the screen in a
  44      clean state (see endwin()).  */
  45   tui_disable ();
  46 }
  47
  48 /* These implement the TUI interpreter.  */
  49
  50 static void *
  51 tui_init (int top_level)
  52 {
  53   /* Install exit handler to leave the screen in a good shape.  */
  54   atexit (tui_exit);
  55
  56   tui_initialize_static_data ();
  57
  58   tui_initialize_io ();
  59   tui_initialize_win ();
  60   if (ui_file_isatty (gdb_stdout))
  61     tui_initialize_readline ();
  62
  63   return NULL;
  64 }
  65
  66 static int
  67 tui_resume (void *data)
  68 {
  69   struct ui_file *stream;
  70
  71   /* gdb_setup_readline will change gdb_stdout.  If the TUI was
  72      previously writing to gdb_stdout, then set it to the new
  73      gdb_stdout afterwards.  */
  74
  75   stream = cli_out_set_stream (tui_old_uiout, gdb_stdout);
  76   if (stream != gdb_stdout)
  77     {
  78       cli_out_set_stream (tui_old_uiout, stream);
  79       stream = NULL;
  80     }
  81
  82   gdb_setup_readline ();
  83
  84   if (stream != NULL)
  85     cli_out_set_stream (tui_old_uiout, gdb_stdout);
  86
  87   if (tui_start_enabled)
  88     tui_enable ();
  89   return 1;
  90 }
  91
  92 static int
  93 tui_suspend (void *data)
  94 {
  95   tui_start_enabled = tui_active;
  96   tui_disable ();
  97   return 1;
  98 }
  99
 100 /* Display the prompt if we are silent.  */
 101
 102 static int
 103 tui_display_prompt_p (void *data)
 104 {
 105   if (interp_quiet_p (NULL))
 106     return 0;
 107   else
 108     return 1;
 109 }
 110
 111 static struct gdb_exception
 112 tui_exec (void *data, const char *command_str)
 113 {
 114   internal_error (__FILE__, __LINE__, _("tui_exec called"));
 115 }
 116
 117
 118 /* Initialize all the necessary variables, start the event loop,
 119    register readline, and stdin, start the loop.  */
 120
 121 static void
 122 tui_command_loop (void *data)
 123 {
 124   /* If we are using readline, set things up and display the first
 125      prompt, otherwise just print the prompt.  */
 126   if (async_command_editing_p)
 127     {
 128       int length;
 129       char *a_prompt;
 130       char *gdb_prompt = get_prompt ();
 131
 132       /* Tell readline what the prompt to display is and what function
 133          it will need to call after a whole line is read. This also
 134          displays the first prompt.  */
 135       length = strlen (PREFIX (0))
 136         + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
 137       a_prompt = (char *) alloca (length);
 138       strcpy (a_prompt, PREFIX (0));
 139       strcat (a_prompt, gdb_prompt);
 140       strcat (a_prompt, SUFFIX (0));
 141       rl_callback_handler_install (a_prompt, input_handler);
 142     }
 143   else
 144     display_gdb_prompt (0);
 145
 146   /* Loop until there is nothing to do. This is the entry point to the
 147      event loop engine. gdb_do_one_event, called via catch_errors()
 148      will process one event for each invocation.  It blocks waits for
 149      an event and then processes it.  >0 when an event is processed, 0
 150      when catch_errors() caught an error and <0 when there are no
 151      longer any event sources registered.  */
 152   while (1)
 153     {
 154       int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
 155       if (result < 0)
 156         break;
 157
 158       /* Update gdb output according to TUI mode.  Since catch_errors
 159          preserves the uiout from changing, this must be done at top
 160          level of event loop.  */
 161       if (tui_active)
 162         uiout = tui_out;
 163       else
 164         uiout = tui_old_uiout;
 165
 166       if (result == 0)
 167         {
 168           /* If any exception escaped to here, we better enable
 169              stdin.  Otherwise, any command that calls async_disable_stdin,
 170              and then throws, will leave stdin inoperable.  */
 171           async_enable_stdin ();
 172           /* FIXME: this should really be a call to a hook that is
 173              interface specific, because interfaces can display the
 174              prompt in their own way.  */
 175           display_gdb_prompt (0);
 176           /* This call looks bizarre, but it is required.  If the user
 177              entered a command that caused an error,
 178              after_char_processing_hook won't be called from
 179              rl_callback_read_char_wrapper.  Using a cleanup there
 180              won't work, since we want this function to be called
 181              after a new prompt is printed.  */
 182           if (after_char_processing_hook)
 183             (*after_char_processing_hook) ();
 184           /* Maybe better to set a flag to be checked somewhere as to
 185              whether display the prompt or not.  */
 186         }
 187     }
 188
 189   /* We are done with the event loop. There are no more event sources
 190      to listen to.  So we exit GDB.  */
 191   return;
 192 }
 193
 194 /* Provide a prototype to silence -Wmissing-prototypes.  */
 195 extern initialize_file_ftype _initialize_tui_interp;
 196
 197 void
 198 _initialize_tui_interp (void)
 199 {
 200   static const struct interp_procs procs = {
 201     tui_init,
 202     tui_resume,
 203     tui_suspend,
 204     tui_exec,
 205     tui_display_prompt_p,
 206     tui_command_loop,
 207   };
 208   struct interp *tui_interp;
 209
 210   /* Create a default uiout builder for the TUI.  */
 211   tui_out = tui_out_new (gdb_stdout);
 212   interp_add (interp_new (INTERP_TUI, NULL, tui_out, &procs));
 213   if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
 214     tui_start_enabled = 1;
 215
 216   if (interpreter_p && strcmp (interpreter_p, INTERP_CONSOLE) == 0)
 217     {
 218       xfree (interpreter_p);
 219       interpreter_p = xstrdup (INTERP_TUI);
 220     }
 221 }