xref: /dragonfly/contrib/gdb-7/gdb/tui/tui-interp.c (revision 6e278935)
1 /* TUI Interpreter definitions for GDB, the GNU debugger.
2 
3    Copyright (C) 2003, 2007, 2008, 2009, 2010, 2011
4    Free Software Foundation, Inc.
5 
6    This file is part of GDB.
7 
8    This program is free software; you can redistribute it and/or modify
9    it under the terms of the GNU General Public License as published by
10    the Free Software Foundation; either version 3 of the License, or
11    (at your option) any later version.
12 
13    This program is distributed in the hope that it will be useful,
14    but WITHOUT ANY WARRANTY; without even the implied warranty of
15    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
16    GNU General Public License for more details.
17 
18    You should have received a copy of the GNU General Public License
19    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
20 
21 #include "defs.h"
22 #include "interps.h"
23 #include "top.h"
24 #include "event-top.h"
25 #include "event-loop.h"
26 #include "ui-out.h"
27 #include "cli-out.h"
28 #include "tui/tui-data.h"
29 #include "readline/readline.h"
30 #include "tui/tui-win.h"
31 #include "tui/tui.h"
32 #include "tui/tui-io.h"
33 #include "exceptions.h"
34 
35 /* Set to 1 when the TUI mode must be activated when we first start
36    gdb.  */
37 static int tui_start_enabled = 0;
38 
39 /* Cleanup the tui before exiting.  */
40 
41 static void
42 tui_exit (void)
43 {
44   /* Disable the tui.  Curses mode is left leaving the screen in a
45      clean state (see endwin()).  */
46   tui_disable ();
47 }
48 
49 /* True if TUI is the top-level interpreter.  */
50 static int tui_is_toplevel = 0;
51 
52 /* These implement the TUI interpreter.  */
53 
54 static void *
55 tui_init (int top_level)
56 {
57   tui_is_toplevel = top_level;
58 
59   /* Install exit handler to leave the screen in a good shape.  */
60   atexit (tui_exit);
61 
62   tui_initialize_static_data ();
63 
64   tui_initialize_io ();
65   tui_initialize_win ();
66   if (ui_file_isatty (gdb_stdout))
67     tui_initialize_readline ();
68 
69   return NULL;
70 }
71 
72 /* True if enabling the TUI is allowed.  Example, if the top level
73    interpreter is MI, enabling curses will certainly lose.  */
74 
75 int
76 tui_allowed_p (void)
77 {
78   /* Only if TUI is the top level interpreter.  Also don't try to
79      setup curses (and print funny control characters) if we're not
80      outputting to a terminal.  */
81   return tui_is_toplevel && ui_file_isatty (gdb_stdout);
82 }
83 
84 static int
85 tui_resume (void *data)
86 {
87   struct ui_file *stream;
88 
89   /* gdb_setup_readline will change gdb_stdout.  If the TUI was
90      previously writing to gdb_stdout, then set it to the new
91      gdb_stdout afterwards.  */
92 
93   stream = cli_out_set_stream (tui_old_uiout, gdb_stdout);
94   if (stream != gdb_stdout)
95     {
96       cli_out_set_stream (tui_old_uiout, stream);
97       stream = NULL;
98     }
99 
100   gdb_setup_readline ();
101 
102   if (stream != NULL)
103     cli_out_set_stream (tui_old_uiout, gdb_stdout);
104 
105   if (tui_start_enabled)
106     tui_enable ();
107   return 1;
108 }
109 
110 static int
111 tui_suspend (void *data)
112 {
113   tui_start_enabled = tui_active;
114   tui_disable ();
115   return 1;
116 }
117 
118 /* Display the prompt if we are silent.  */
119 
120 static int
121 tui_display_prompt_p (void *data)
122 {
123   if (interp_quiet_p (NULL))
124     return 0;
125   else
126     return 1;
127 }
128 
129 static struct gdb_exception
130 tui_exec (void *data, const char *command_str)
131 {
132   internal_error (__FILE__, __LINE__, _("tui_exec called"));
133 }
134 
135 
136 /* Initialize all the necessary variables, start the event loop,
137    register readline, and stdin, start the loop.  */
138 
139 static void
140 tui_command_loop (void *data)
141 {
142   /* If we are using readline, set things up and display the first
143      prompt, otherwise just print the prompt.  */
144   if (async_command_editing_p)
145     {
146       int length;
147       char *a_prompt;
148       char *gdb_prompt = get_prompt ();
149 
150       /* Tell readline what the prompt to display is and what function
151          it will need to call after a whole line is read. This also
152          displays the first prompt.  */
153       length = strlen (PREFIX (0))
154 	+ strlen (gdb_prompt) + strlen (SUFFIX (0)) + 1;
155       a_prompt = (char *) alloca (length);
156       strcpy (a_prompt, PREFIX (0));
157       strcat (a_prompt, gdb_prompt);
158       strcat (a_prompt, SUFFIX (0));
159       rl_callback_handler_install (a_prompt, input_handler);
160     }
161   else
162     display_gdb_prompt (0);
163 
164   /* Loop until there is nothing to do. This is the entry point to the
165      event loop engine. gdb_do_one_event, called via catch_errors()
166      will process one event for each invocation.  It blocks waits for
167      an event and then processes it.  >0 when an event is processed, 0
168      when catch_errors() caught an error and <0 when there are no
169      longer any event sources registered.  */
170   while (1)
171     {
172       int result = catch_errors (gdb_do_one_event, 0, "", RETURN_MASK_ALL);
173 
174       if (result < 0)
175 	break;
176 
177       /* Update gdb output according to TUI mode.  Since catch_errors
178          preserves the uiout from changing, this must be done at top
179          level of event loop.  */
180       if (tui_active)
181         uiout = tui_out;
182       else
183         uiout = tui_old_uiout;
184 
185       if (result == 0)
186 	{
187 	  /* If any exception escaped to here, we better enable
188 	     stdin.  Otherwise, any command that calls async_disable_stdin,
189 	     and then throws, will leave stdin inoperable.  */
190 	  async_enable_stdin ();
191 	  /* FIXME: this should really be a call to a hook that is
192 	     interface specific, because interfaces can display the
193 	     prompt in their own way.  */
194 	  display_gdb_prompt (0);
195 	  /* This call looks bizarre, but it is required.  If the user
196 	     entered a command that caused an error,
197 	     after_char_processing_hook won't be called from
198 	     rl_callback_read_char_wrapper.  Using a cleanup there
199 	     won't work, since we want this function to be called
200 	     after a new prompt is printed.  */
201 	  if (after_char_processing_hook)
202 	    (*after_char_processing_hook) ();
203 	  /* Maybe better to set a flag to be checked somewhere as to
204 	     whether display the prompt or not.  */
205 	}
206     }
207 
208   /* We are done with the event loop. There are no more event sources
209      to listen to.  So we exit GDB.  */
210   return;
211 }
212 
213 /* Provide a prototype to silence -Wmissing-prototypes.  */
214 extern initialize_file_ftype _initialize_tui_interp;
215 
216 void
217 _initialize_tui_interp (void)
218 {
219   static const struct interp_procs procs = {
220     tui_init,
221     tui_resume,
222     tui_suspend,
223     tui_exec,
224     tui_display_prompt_p,
225     tui_command_loop,
226   };
227 
228   /* Create a default uiout builder for the TUI.  */
229   tui_out = tui_out_new (gdb_stdout);
230   interp_add (interp_new (INTERP_TUI, NULL, tui_out, &procs));
231   if (interpreter_p && strcmp (interpreter_p, INTERP_TUI) == 0)
232     tui_start_enabled = 1;
233 
234   if (interpreter_p && strcmp (interpreter_p, INTERP_CONSOLE) == 0)
235     {
236       xfree (interpreter_p);
237       interpreter_p = xstrdup (INTERP_TUI);
238     }
239 }
240