gdb/tui/tui-interp.c

   1 /* TUI Interpreter definitions for GDB, the GNU debugger.
   2
   3    Copyright 2003 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 2 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, write to the Free Software
  19    Foundation, Inc., 59 Temple Place - Suite 330,
  20    Boston, MA 02111-1307, USA.  */
  21
  22 #include "defs.h"
  23 #include "interps.h"
  24 #include "top.h"
  25 #include "event-top.h"
  26 #include "event-loop.h"
  27 #include "ui-out.h"
  28 #include "cli-out.h"
  29 #include "tui/tui-data.h"
  30 #include "readline/readline.h"
  31 #include "tui/tui-win.h"
  32 #include "tui/tui.h"
  33 #include "tui/tui-io.h"
  34
  35 /* Set to 1 when the TUI mode must be activated when we first start 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
  44      in a clean state (see endwin()).  */
  45   tui_disable ();
  46 }
  47
  48 /* These implement the TUI interpreter.  */
  49
  50 static void *
  51 tui_init (void)
  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_readline ();
  60
  61   return NULL;
  62 }
  63
  64 static int
  65 tui_resume (void *data)
  66 {
  67   struct ui_file *stream;
  68
  69   /* gdb_setup_readline will change gdb_stdout.  If the TUI was previously
  70      writing to gdb_stdout, then set it to the new gdb_stdout afterwards.  */
  71
  72   stream = cli_out_set_stream (tui_old_uiout, gdb_stdout);
  73   if (stream != gdb_stdout)
  74     {
  75       cli_out_set_stream (tui_old_uiout, stream);
  76       stream = NULL;
  77     }
  78
  79   gdb_setup_readline ();
  80
  81   if (stream != NULL)
  82     cli_out_set_stream (tui_old_uiout, gdb_stdout);
  83
  84   if (tui_start_enabled)
  85     tui_enable ();
  86   return 1;
  87 }
  88
  89 static int
  90 tui_suspend (void *data)
  91 {
  92   tui_start_enabled = tui_active;
  93   tui_disable ();
  94   return 1;
  95 }
  96
  97 /* Display the prompt if we are silent.  */
  98
  99 static int
 100 tui_display_prompt_p (void *data)
 101 {
 102   if (interp_quiet_p (NULL))
 103     return 0;
 104   else
 105     return 1;
 106 }
 107
 108 static int
 109 tui_exec (void *data, const char *command_str)
 110 {
 111   internal_error (__FILE__, __LINE__, "tui_exec called");
 112 }
 113
 114
 115 /* Initialize all the necessary variables, start the event loop,
 116    register readline, and stdin, start the loop.  */
 117
 118 static void
 119 tui_command_loop (void *data)
 120 {
 121   int length;
 122   char *a_prompt;
 123   char *gdb_prompt = get_prompt ();
 124
 125   /* If we are using readline, set things up and display the first
 126      prompt, otherwise just print the prompt.  */
 127   if (async_command_editing_p)
 128     {
 129       /* Tell readline what the prompt to display is and what function
 130          it will need to call after a whole line is read. This also
 131          displays the first prompt.  */
 132       length = strlen (PREFIX (0)) + strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
 133       a_prompt = (char *) xmalloc (length);
 134       strcpy (a_prompt, PREFIX (0));
 135       strcat (a_prompt, gdb_prompt);
 136       strcat (a_prompt, SUFFIX (0));
 137       rl_callback_handler_install (a_prompt, input_handler);
 138     }
 139   else
 140     display_gdb_prompt (0);
 141
 142   /* Loop until there is nothing to do. This is the entry point to the
 143      event loop engine. gdb_do_one_event, called via catch_errors()
 144      will process one event for each invocation.  It blocks waits for
 145      an event and then processes it.  >0 when an event is processed, 0
 146      when catch_errors() caught an error and <0 when there are no
 147      longer any event sources registered.  */
 148   while (1)
 149     {
 150       int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
 151       if (result < 0)
 152         break;
 153
 154       /* Update gdb output according to TUI mode.  Since catch_errors
 155          preserves the uiout from changing, this must be done at top
 156          level of event loop.  */
 157       if (tui_active)
 158         uiout = tui_out;
 159       else
 160         uiout = tui_old_uiout;
 161
 162       if (result == 0)
 163         {
 164           /* FIXME: this should really be a call to a hook that is
 165              interface specific, because interfaces can display the
 166              prompt in their own way.  */
 167           display_gdb_prompt (0);
 168           /* This call looks bizarre, but it is required.  If the user
 169              entered a command that caused an error,
 170              after_char_processing_hook won't be called from
 171              rl_callback_read_char_wrapper.  Using a cleanup there
 172              won't work, since we want this function to be called
 173              after a new prompt is printed.  */
 174           if (after_char_processing_hook)
 175             (*after_char_processing_hook) ();
 176           /* Maybe better to set a flag to be checked somewhere as to
 177              whether display the prompt or not.  */
 178         }
 179     }
 180
 181   /* We are done with the event loop. There are no more event sources
 182      to listen to.  So we exit GDB.  */
 183   return;
 184 }
 185
 186 void
 187 _initialize_tui_interp (void)
 188 {
 189   static const struct interp_procs procs = {
 190     tui_init,
 191     tui_resume,
 192     tui_suspend,
 193     tui_exec,
 194     tui_display_prompt_p,
 195     tui_command_loop,
 196   };
 197   struct interp *tui_interp;
 198
 199   /* Create a default uiout builder for the TUI. */
 200   tui_out = tui_out_new (gdb_stdout);
 201   interp_add (interp_new ("tui", NULL, tui_out, &procs));
 202   if (interpreter_p && strcmp (interpreter_p, "tui") == 0)
 203     tui_start_enabled = 1;
 204
 205   if (interpreter_p && strcmp (interpreter_p, INTERP_CONSOLE) == 0)
 206     {
 207       xfree (interpreter_p);
 208       interpreter_p = xstrdup ("tui");
 209     }
 210 }