gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002-2003, 2007-2012 Free Software Foundation,
   4    Inc.
   5
   6    Written by Jim Ingham <jingham@apple.com> of Apple Computer, Inc.
   7
   8    This file is part of GDB.
   9
  10    This program is free software; you can redistribute it and/or modify
  11    it under the terms of the GNU General Public License as published by
  12    the Free Software Foundation; either version 3 of the License, or
  13    (at your option) any later version.
  14
  15    This program is distributed in the hope that it will be useful,
  16    but WITHOUT ANY WARRANTY; without even the implied warranty of
  17    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18    GNU General Public License for more details.
  19
  20    You should have received a copy of the GNU General Public License
  21    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  22
  23 /* This is just a first cut at separating out the "interpreter"
  24    functions of gdb into self-contained modules.  There are a couple
  25    of open areas that need to be sorted out:
  26
  27    1) The interpreter explicitly contains a UI_OUT, and can insert itself
  28    into the event loop, but it doesn't explicitly contain hooks for readline.
  29    I did this because it seems to me many interpreters won't want to use
  30    the readline command interface, and it is probably simpler to just let
  31    them take over the input in their resume proc.  */
  32
  33 #include "defs.h"
  34 #include "gdbcmd.h"
  35 #include "ui-out.h"
  36 #include "event-loop.h"
  37 #include "event-top.h"
  38 #include "interps.h"
  39 #include "completer.h"
  40 #include "gdb_string.h"
  41 #include "gdb_assert.h"
  42 #include "top.h"                /* For command_loop.  */
  43 #include "exceptions.h"
  44 #include "continuations.h"
  45
  46 /* True if the current interpreter in is async mode.  See interps.h
  47    for more details.  This starts out disabled, until all the explicit
  48    command line arguments (e.g., `gdb -ex "start" -ex "next"') are
  49    processed.  */
  50 int interpreter_async = 0;
  51
  52 struct interp
  53 {
  54   /* This is the name in "-i=" and set interpreter.  */
  55   const char *name;
  56
  57   /* Interpreters are stored in a linked list, this is the next
  58      one...  */
  59   struct interp *next;
  60
  61   /* This is a cookie that an instance of the interpreter can use.
  62      This is a bit confused right now as the exact initialization
  63      sequence for it, and how it relates to the interpreter's uiout
  64      object is a bit confused.  */
  65   void *data;
  66
  67   /* Has the init_proc been run?  */
  68   int inited;
  69
  70   const struct interp_procs *procs;
  71   int quiet_p;
  72 };
  73
  74 /* Functions local to this file.  */
  75 static void initialize_interps (void);
  76 static char **interpreter_completer (struct cmd_list_element *cmd,
  77                                      char *text, char *word);
  78
  79 /* The magic initialization routine for this module.  */
  80
  81 void _initialize_interpreter (void);
  82
  83 /* Variables local to this file: */
  84
  85 static struct interp *interp_list = NULL;
  86 static struct interp *current_interpreter = NULL;
  87 static struct interp *top_level_interpreter_ptr = NULL;
  88
  89 static int interpreter_initialized = 0;
  90
  91 /* interp_new - This allocates space for a new interpreter,
  92    fills the fields from the inputs, and returns a pointer to the
  93    interpreter.  */
  94 struct interp *
  95 interp_new (const char *name, const struct interp_procs *procs)
  96 {
  97   struct interp *new_interp;
  98
  99   new_interp = XMALLOC (struct interp);
 100
 101   new_interp->name = xstrdup (name);
 102   new_interp->data = NULL;
 103   new_interp->quiet_p = 0;
 104   new_interp->procs = procs;
 105   new_interp->inited = 0;
 106
 107   return new_interp;
 108 }
 109
 110 /* Add interpreter INTERP to the gdb interpreter list.  The
 111    interpreter must not have previously been added.  */
 112 void
 113 interp_add (struct interp *interp)
 114 {
 115   if (!interpreter_initialized)
 116     initialize_interps ();
 117
 118   gdb_assert (interp_lookup (interp->name) == NULL);
 119
 120   interp->next = interp_list;
 121   interp_list = interp;
 122 }
 123
 124 /* This sets the current interpreter to be INTERP.  If INTERP has not
 125    been initialized, then this will also run the init proc.  If the
 126    init proc is successful, return 1, if it fails, set the old
 127    interpreter back in place and return 0.  If we can't restore the
 128    old interpreter, then raise an internal error, since we are in
 129    pretty bad shape at this point.
 130
 131    The TOP_LEVEL parameter tells if this new interpreter is
 132    the top-level one.  The top-level is what is requested
 133    on the command line, and is responsible for reporting general
 134    notification about target state changes.  For example, if
 135    MI is the top-level interpreter, then it will always report
 136    events such as target stops and new thread creation, even if they
 137    are caused by CLI commands.  */
 138 int
 139 interp_set (struct interp *interp, int top_level)
 140 {
 141   struct interp *old_interp = current_interpreter;
 142   int first_time = 0;
 143   char buffer[64];
 144
 145   /* If we already have an interpreter, then trying to
 146      set top level interpreter is kinda pointless.  */
 147   gdb_assert (!top_level || !current_interpreter);
 148   gdb_assert (!top_level || !top_level_interpreter_ptr);
 149
 150   if (current_interpreter != NULL)
 151     {
 152       ui_out_flush (current_uiout);
 153       if (current_interpreter->procs->suspend_proc
 154           && !current_interpreter->procs->suspend_proc (current_interpreter->
 155                                                         data))
 156         {
 157           error (_("Could not suspend interpreter \"%s\"."),
 158                  current_interpreter->name);
 159         }
 160     }
 161   else
 162     {
 163       first_time = 1;
 164     }
 165
 166   current_interpreter = interp;
 167   if (top_level)
 168     top_level_interpreter_ptr = interp;
 169
 170   /* We use interpreter_p for the "set interpreter" variable, so we need
 171      to make sure we have a malloc'ed copy for the set command to free.  */
 172   if (interpreter_p != NULL
 173       && strcmp (current_interpreter->name, interpreter_p) != 0)
 174     {
 175       xfree (interpreter_p);
 176
 177       interpreter_p = xstrdup (current_interpreter->name);
 178     }
 179
 180   /* Run the init proc.  If it fails, try to restore the old interp.  */
 181
 182   if (!interp->inited)
 183     {
 184       if (interp->procs->init_proc != NULL)
 185         {
 186           interp->data = interp->procs->init_proc (interp, top_level);
 187         }
 188       interp->inited = 1;
 189     }
 190
 191   /* Do this only after the interpreter is initialized.  */
 192   current_uiout = interp->procs->ui_out_proc (interp);
 193
 194   /* Clear out any installed interpreter hooks/event handlers.  */
 195   clear_interpreter_hooks ();
 196
 197   if (interp->procs->resume_proc != NULL
 198       && (!interp->procs->resume_proc (interp->data)))
 199     {
 200       if (old_interp == NULL || !interp_set (old_interp, 0))
 201         internal_error (__FILE__, __LINE__,
 202                         _("Failed to initialize new interp \"%s\" %s"),
 203                         interp->name, "and could not restore old interp!\n");
 204       return 0;
 205     }
 206
 207   /* Finally, put up the new prompt to show that we are indeed here.
 208      Also, display_gdb_prompt for the console does some readline magic
 209      which is needed for the console interpreter, at least...  */
 210
 211   if (!first_time)
 212     {
 213       if (!interp_quiet_p (interp))
 214         {
 215           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 216                    interp->name);
 217           ui_out_text (current_uiout, buffer);
 218         }
 219       display_gdb_prompt (NULL);
 220     }
 221
 222   return 1;
 223 }
 224
 225 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 226    interpreter exists, return NULL, otherwise return a pointer to the
 227    interpreter.  */
 228 struct interp *
 229 interp_lookup (const char *name)
 230 {
 231   struct interp *interp;
 232
 233   if (name == NULL || strlen (name) == 0)
 234     return NULL;
 235
 236   for (interp = interp_list; interp != NULL; interp = interp->next)
 237     {
 238       if (strcmp (interp->name, name) == 0)
 239         return interp;
 240     }
 241
 242   return NULL;
 243 }
 244
 245 /* Returns the current interpreter.  */
 246
 247 struct ui_out *
 248 interp_ui_out (struct interp *interp)
 249 {
 250   if (interp != NULL)
 251     return interp->procs->ui_out_proc (interp);
 252
 253   return current_interpreter->procs->ui_out_proc (current_interpreter);
 254 }
 255
 256 /* Returns the interpreter's cookie.  */
 257
 258 void *
 259 interp_data (struct interp *interp)
 260 {
 261   return interp->data;
 262 }
 263
 264 /* Returns the interpreter's name.  */
 265
 266 const char *
 267 interp_name (struct interp *interp)
 268 {
 269   return interp->name;
 270 }
 271
 272 /* Returns true if the current interp is the passed in name.  */
 273 int
 274 current_interp_named_p (const char *interp_name)
 275 {
 276   if (current_interpreter)
 277     return (strcmp (current_interpreter->name, interp_name) == 0);
 278
 279   return 0;
 280 }
 281
 282 /* This is called in display_gdb_prompt.  If the proc returns a zero
 283    value, display_gdb_prompt will return without displaying the
 284    prompt.  */
 285 int
 286 current_interp_display_prompt_p (void)
 287 {
 288   if (current_interpreter == NULL
 289       || current_interpreter->procs->prompt_proc_p == NULL)
 290     return 0;
 291   else
 292     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 293                                                       data);
 294 }
 295
 296 /* Run the current command interpreter's main loop.  */
 297 void
 298 current_interp_command_loop (void)
 299 {
 300   /* Somewhat messy.  For the moment prop up all the old ways of
 301      selecting the command loop.  `deprecated_command_loop_hook'
 302      should be deprecated.  */
 303   if (deprecated_command_loop_hook != NULL)
 304     deprecated_command_loop_hook ();
 305   else if (current_interpreter != NULL
 306            && current_interpreter->procs->command_loop_proc != NULL)
 307     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 308   else
 309     cli_command_loop ();
 310 }
 311
 312 int
 313 interp_quiet_p (struct interp *interp)
 314 {
 315   if (interp != NULL)
 316     return interp->quiet_p;
 317   else
 318     return current_interpreter->quiet_p;
 319 }
 320
 321 static int
 322 interp_set_quiet (struct interp *interp, int quiet)
 323 {
 324   int old_val = interp->quiet_p;
 325
 326   interp->quiet_p = quiet;
 327   return old_val;
 328 }
 329
 330 /* interp_exec - This executes COMMAND_STR in the current
 331    interpreter.  */
 332 int
 333 interp_exec_p (struct interp *interp)
 334 {
 335   return interp->procs->exec_proc != NULL;
 336 }
 337
 338 struct gdb_exception
 339 interp_exec (struct interp *interp, const char *command_str)
 340 {
 341   if (interp->procs->exec_proc != NULL)
 342     {
 343       return interp->procs->exec_proc (interp->data, command_str);
 344     }
 345   return exception_none;
 346 }
 347
 348 /* A convenience routine that nulls out all the common command hooks.
 349    Use it when removing your interpreter in its suspend proc.  */
 350 void
 351 clear_interpreter_hooks (void)
 352 {
 353   deprecated_init_ui_hook = 0;
 354   deprecated_print_frame_info_listing_hook = 0;
 355   /*print_frame_more_info_hook = 0; */
 356   deprecated_query_hook = 0;
 357   deprecated_warning_hook = 0;
 358   deprecated_interactive_hook = 0;
 359   deprecated_readline_begin_hook = 0;
 360   deprecated_readline_hook = 0;
 361   deprecated_readline_end_hook = 0;
 362   deprecated_register_changed_hook = 0;
 363   deprecated_context_hook = 0;
 364   deprecated_target_wait_hook = 0;
 365   deprecated_call_command_hook = 0;
 366   deprecated_error_begin_hook = 0;
 367   deprecated_command_loop_hook = 0;
 368 }
 369
 370 /* This is a lazy init routine, called the first time the interpreter
 371    module is used.  I put it here just in case, but I haven't thought
 372    of a use for it yet.  I will probably bag it soon, since I don't
 373    think it will be necessary.  */
 374 static void
 375 initialize_interps (void)
 376 {
 377   interpreter_initialized = 1;
 378   /* Don't know if anything needs to be done here...  */
 379 }
 380
 381 static void
 382 interpreter_exec_cmd (char *args, int from_tty)
 383 {
 384   struct interp *old_interp, *interp_to_use;
 385   char **prules = NULL;
 386   char **trule = NULL;
 387   unsigned int nrules;
 388   unsigned int i;
 389   int old_quiet, use_quiet;
 390
 391   if (args == NULL)
 392     error_no_arg (_("interpreter-exec command"));
 393
 394   prules = gdb_buildargv (args);
 395   make_cleanup_freeargv (prules);
 396
 397   nrules = 0;
 398   for (trule = prules; *trule != NULL; trule++)
 399     nrules++;
 400
 401   if (nrules < 2)
 402     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 403
 404   old_interp = current_interpreter;
 405
 406   interp_to_use = interp_lookup (prules[0]);
 407   if (interp_to_use == NULL)
 408     error (_("Could not find interpreter \"%s\"."), prules[0]);
 409
 410   /* Temporarily set interpreters quiet.  */
 411   old_quiet = interp_set_quiet (old_interp, 1);
 412   use_quiet = interp_set_quiet (interp_to_use, 1);
 413
 414   if (!interp_set (interp_to_use, 0))
 415     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 416
 417   for (i = 1; i < nrules; i++)
 418     {
 419       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 420
 421       if (e.reason < 0)
 422         {
 423           interp_set (old_interp, 0);
 424           interp_set_quiet (interp_to_use, use_quiet);
 425           interp_set_quiet (old_interp, old_quiet);
 426           error (_("error in command: \"%s\"."), prules[i]);
 427         }
 428     }
 429
 430   interp_set (old_interp, 0);
 431   interp_set_quiet (interp_to_use, use_quiet);
 432   interp_set_quiet (old_interp, old_quiet);
 433 }
 434
 435 /* List the possible interpreters which could complete the given text.  */
 436 static char **
 437 interpreter_completer (struct cmd_list_element *ignore, char *text, char *word)
 438 {
 439   int alloced = 0;
 440   int textlen;
 441   int num_matches;
 442   char **matches;
 443   struct interp *interp;
 444
 445   /* We expect only a very limited number of interpreters, so just
 446      allocate room for all of them plus one for the last that must be NULL
 447      to correctly end the list.  */
 448   for (interp = interp_list; interp != NULL; interp = interp->next)
 449     ++alloced;
 450   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 451
 452   num_matches = 0;
 453   textlen = strlen (text);
 454   for (interp = interp_list; interp != NULL; interp = interp->next)
 455     {
 456       if (strncmp (interp->name, text, textlen) == 0)
 457         {
 458           matches[num_matches] =
 459             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 460           if (word == text)
 461             strcpy (matches[num_matches], interp->name);
 462           else if (word > text)
 463             {
 464               /* Return some portion of interp->name.  */
 465               strcpy (matches[num_matches], interp->name + (word - text));
 466             }
 467           else
 468             {
 469               /* Return some of text plus interp->name.  */
 470               strncpy (matches[num_matches], word, text - word);
 471               matches[num_matches][text - word] = '\0';
 472               strcat (matches[num_matches], interp->name);
 473             }
 474           ++num_matches;
 475         }
 476     }
 477
 478   if (num_matches == 0)
 479     {
 480       xfree (matches);
 481       matches = NULL;
 482     }
 483
 484   return matches;
 485 }
 486
 487 struct interp *
 488 top_level_interpreter (void)
 489 {
 490   return top_level_interpreter_ptr;
 491 }
 492
 493 void *
 494 top_level_interpreter_data (void)
 495 {
 496   gdb_assert (top_level_interpreter_ptr);
 497   return top_level_interpreter_ptr->data;
 498 }
 499
 500 /* This just adds the "interpreter-exec" command.  */
 501 void
 502 _initialize_interpreter (void)
 503 {
 504   struct cmd_list_element *c;
 505
 506   c = add_cmd ("interpreter-exec", class_support,
 507                interpreter_exec_cmd, _("\
 508 Execute a command in an interpreter.  It takes two arguments:\n\
 509 The first argument is the name of the interpreter to use.\n\
 510 The second argument is the command to execute.\n"), &cmdlist);
 511   set_cmd_completer (c, interpreter_completer);
 512 }