gdb/tui/tui-interp.c

   1 /* TUI Interpreter definitions for GDB, the GNU debugger.
   2
   3    Copyright (C) 2003, 2007, 2008 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   tui_initialize_readline ();
  61
  62   return NULL;
  63 }
  64
  65 static int
  66 tui_resume (void *data)
  67 {
  68   struct ui_file *stream;
  69
  70   /* gdb_setup_readline will change gdb_stdout.  If the TUI was
  71      previously writing to gdb_stdout, then set it to the new
  72      gdb_stdout afterwards.  */
  73
  74   stream = cli_out_set_stream (tui_old_uiout, gdb_stdout);
  75   if (stream != gdb_stdout)
  76     {
  77       cli_out_set_stream (tui_old_uiout, stream);
  78       stream = NULL;
  79     }
  80
  81   gdb_setup_readline ();
  82
  83   if (stream != NULL)
  84     cli_out_set_stream (tui_old_uiout, gdb_stdout);
  85
  86   if (tui_start_enabled)
  87     tui_enable ();
  88   return 1;
  89 }
  90
  91 static int
  92 tui_suspend (void *data)
  93 {
  94   tui_start_enabled = tui_active;
  95   tui_disable ();
  96   return 1;
  97 }
  98
  99 /* Display the prompt if we are silent.  */
 100
 101 static int
 102 tui_display_prompt_p (void *data)
 103 {
 104   if (interp_quiet_p (NULL))
 105     return 0;
 106   else
 107     return 1;
 108 }
 109
 110 static struct gdb_exception
 111 tui_exec (void *data, const char *command_str)
 112 {
 113   internal_error (__FILE__, __LINE__, _("tui_exec called"));
 114 }
 115
 116
 117 /* Initialize all the necessary variables, start the event loop,
 118    register readline, and stdin, start the loop.  */
 119
 120 static void
 121 tui_command_loop (void *data)
 122 {
 123   /* If we are using readline, set things up and display the first
 124      prompt, otherwise just print the prompt.  */
 125   if (async_command_editing_p)
 126     {
 127       int length;
 128       char *a_prompt;
 129       char *gdb_prompt = get_prompt ();
 130
 131       /* Tell readline what the prompt to display is and what function
 132          it will need to call after a whole line is read. This also
 133          displays the first prompt.  */
 134       length = strlen (PREFIX (0))
 135         + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
 136       a_prompt = (char *) alloca (length);
 137       strcpy (a_prompt, PREFIX (0));
 138       strcat (a_prompt, gdb_prompt);
 139       strcat (a_prompt, SUFFIX (0));
 140       rl_callback_handler_install (a_prompt, input_handler);
 141     }
 142   else
 143     display_gdb_prompt (0);
 144
 145   /* Loop until there is nothing to do. This is the entry point to the
 146      event loop engine. gdb_do_one_event, called via catch_errors()
 147      will process one event for each invocation.  It blocks waits for
 148      an event and then processes it.  >0 when an event is processed, 0
 149      when catch_errors() caught an error and <0 when there are no
 150      longer any event sources registered.  */
 151   while (1)
 152     {
 153       int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
 154       if (result < 0)
 155         break;
 156
 157       /* Update gdb output according to TUI mode.  Since catch_errors
 158          preserves the uiout from changing, this must be done at top
 159          level of event loop.  */
 160       if (tui_active)
 161         uiout = tui_out;
 162       else
 163         uiout = tui_old_uiout;
 164
 165       if (result == 0)
 166         {
 167           /* If any exception escaped to here, we better enable
 168              stdin.  Otherwise, any command that calls async_disable_stdin,
 169              and then throws, will leave stdin inoperable.  */
 170           async_enable_stdin ((void *) 0);
 171           /* FIXME: this should really be a call to a hook that is
 172              interface specific, because interfaces can display the
 173              prompt in their own way.  */
 174           display_gdb_prompt (0);
 175           /* This call looks bizarre, but it is required.  If the user
 176              entered a command that caused an error,
 177              after_char_processing_hook won't be called from
 178              rl_callback_read_char_wrapper.  Using a cleanup there
 179              won't work, since we want this function to be called
 180              after a new prompt is printed.  */
 181           if (after_char_processing_hook)
 182             (*after_char_processing_hook) ();
 183           /* Maybe better to set a flag to be checked somewhere as to
 184              whether display the prompt or not.  */
 185         }
 186     }
 187
 188   /* We are done with the event loop. There are no more event sources
 189      to listen to.  So we exit GDB.  */
 190   return;
 191 }
 192
 193 void
 194 _initialize_tui_interp (void)
 195 {
 196   static const struct interp_procs procs = {
 197     tui_init,
 198     tui_resume,
 199     tui_suspend,
 200     tui_exec,
 201     tui_display_prompt_p,
 202     tui_command_loop,
 203   };
 204   struct interp *tui_interp;
 205
 206   /* Create a default uiout builder for the TUI.  */
 207   tui_out = tui_out_new (gdb_stdout);
 208   interp_add (interp_new (INTERP_TUI, NULL, tui_out, &procs));
 209   if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
 210     tui_start_enabled = 1;
 211
 212   if (interpreter_p && strcmp (interpreter_p, INTERP_CONSOLE) == 0)
 213     {
 214       xfree (interpreter_p);
 215       interpreter_p = xstrdup (INTERP_TUI);
 216     }
 217 }