gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002, 2003, 2007, 2008, 2009
   4    Free Software Foundation, 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
  45 struct interp
  46 {
  47   /* This is the name in "-i=" and set interpreter. */
  48   const char *name;
  49
  50   /* Interpreters are stored in a linked list, this is the next
  51      one...  */
  52   struct interp *next;
  53
  54   /* This is a cookie that an instance of the interpreter can use.
  55      This is a bit confused right now as the exact initialization
  56      sequence for it, and how it relates to the interpreter's uiout
  57      object is a bit confused.  */
  58   void *data;
  59
  60   /* Has the init_proc been run? */
  61   int inited;
  62
  63   /* This is the ui_out used to collect results for this interpreter.
  64      It can be a formatter for stdout, as is the case for the console
  65      & mi outputs, or it might be a result formatter.  */
  66   struct ui_out *interpreter_out;
  67
  68   const struct interp_procs *procs;
  69   int quiet_p;
  70 };
  71
  72 /* Functions local to this file. */
  73 static void initialize_interps (void);
  74 static char **interpreter_completer (char *text, char *word);
  75
  76 /* The magic initialization routine for this module. */
  77
  78 void _initialize_interpreter (void);
  79
  80 /* Variables local to this file: */
  81
  82 static struct interp *interp_list = NULL;
  83 static struct interp *current_interpreter = NULL;
  84 static struct interp *top_level_interpreter_ptr = NULL;
  85
  86 static int interpreter_initialized = 0;
  87
  88 /* interp_new - This allocates space for a new interpreter,
  89    fills the fields from the inputs, and returns a pointer to the
  90    interpreter. */
  91 struct interp *
  92 interp_new (const char *name, void *data, struct ui_out *uiout,
  93             const struct interp_procs *procs)
  94 {
  95   struct interp *new_interp;
  96
  97   new_interp = XMALLOC (struct interp);
  98
  99   new_interp->name = xstrdup (name);
 100   new_interp->data = data;
 101   new_interp->interpreter_out = uiout;
 102   new_interp->quiet_p = 0;
 103   new_interp->procs = procs;
 104   new_interp->inited = 0;
 105
 106   return new_interp;
 107 }
 108
 109 /* Add interpreter INTERP to the gdb interpreter list.  The
 110    interpreter must not have previously been added.  */
 111 void
 112 interp_add (struct interp *interp)
 113 {
 114   if (!interpreter_initialized)
 115     initialize_interps ();
 116
 117   gdb_assert (interp_lookup (interp->name) == NULL);
 118
 119   interp->next = interp_list;
 120   interp_list = interp;
 121 }
 122
 123 /* This sets the current interpreter to be INTERP.  If INTERP has not
 124    been initialized, then this will also run the init proc.  If the
 125    init proc is successful, return 1, if it fails, set the old
 126    interpreter back in place and return 0.  If we can't restore the
 127    old interpreter, then raise an internal error, since we are in
 128    pretty bad shape at this point.
 129
 130    The TOP_LEVEL parameter tells if this new interpreter is
 131    the top-level one.  The top-level is what is requested
 132    on the command line, and is responsible for reporting general
 133    notification about target state changes.  For example, if
 134    MI is the top-level interpreter, then it will always report
 135    events such as target stops and new thread creation, even if they
 136    are caused by CLI commands.  */
 137 int
 138 interp_set (struct interp *interp, int top_level)
 139 {
 140   struct interp *old_interp = current_interpreter;
 141   int first_time = 0;
 142   char buffer[64];
 143
 144   /* If we already have an interpreter, then trying to
 145      set top level interpreter is kinda pointless.  */
 146   gdb_assert (!top_level || !current_interpreter);
 147   gdb_assert (!top_level || !top_level_interpreter_ptr);
 148
 149   if (current_interpreter != NULL)
 150     {
 151       do_all_continuations ();
 152       ui_out_flush (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   uiout = interp->interpreter_out;
 181
 182   /* Run the init proc.  If it fails, try to restore the old interp. */
 183
 184   if (!interp->inited)
 185     {
 186       if (interp->procs->init_proc != NULL)
 187         {
 188           interp->data = interp->procs->init_proc (top_level);
 189         }
 190       interp->inited = 1;
 191     }
 192
 193   /* Clear out any installed interpreter hooks/event handlers.  */
 194   clear_interpreter_hooks ();
 195
 196   if (interp->procs->resume_proc != NULL
 197       && (!interp->procs->resume_proc (interp->data)))
 198     {
 199       if (old_interp == NULL || !interp_set (old_interp, 0))
 200         internal_error (__FILE__, __LINE__,
 201                         _("Failed to initialize new interp \"%s\" %s"),
 202                         interp->name, "and could not restore old interp!\n");
 203       return 0;
 204     }
 205
 206   /* Finally, put up the new prompt to show that we are indeed here.
 207      Also, display_gdb_prompt for the console does some readline magic
 208      which is needed for the console interpreter, at least... */
 209
 210   if (!first_time)
 211     {
 212       if (!interp_quiet_p (interp))
 213         {
 214           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 215                    interp->name);
 216           ui_out_text (uiout, buffer);
 217         }
 218       display_gdb_prompt (NULL);
 219     }
 220
 221   return 1;
 222 }
 223
 224 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 225    interpreter exists, return NULL, otherwise return a pointer to the
 226    interpreter.  */
 227 struct interp *
 228 interp_lookup (const char *name)
 229 {
 230   struct interp *interp;
 231
 232   if (name == NULL || strlen (name) == 0)
 233     return NULL;
 234
 235   for (interp = interp_list; interp != NULL; interp = interp->next)
 236     {
 237       if (strcmp (interp->name, name) == 0)
 238         return interp;
 239     }
 240
 241   return NULL;
 242 }
 243
 244 /* Returns the current interpreter. */
 245
 246 struct ui_out *
 247 interp_ui_out (struct interp *interp)
 248 {
 249   if (interp != NULL)
 250     return interp->interpreter_out;
 251
 252   return current_interpreter->interpreter_out;
 253 }
 254
 255 /* Returns true if the current interp is the passed in name. */
 256 int
 257 current_interp_named_p (const char *interp_name)
 258 {
 259   if (current_interpreter)
 260     return (strcmp (current_interpreter->name, interp_name) == 0);
 261
 262   return 0;
 263 }
 264
 265 /* This is called in display_gdb_prompt.  If the proc returns a zero
 266    value, display_gdb_prompt will return without displaying the
 267    prompt.  */
 268 int
 269 current_interp_display_prompt_p (void)
 270 {
 271   if (current_interpreter == NULL
 272       || current_interpreter->procs->prompt_proc_p == NULL)
 273     return 0;
 274   else
 275     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 276                                                       data);
 277 }
 278
 279 /* Run the current command interpreter's main loop.  */
 280 void
 281 current_interp_command_loop (void)
 282 {
 283   /* Somewhat messy.  For the moment prop up all the old ways of
 284      selecting the command loop.  `deprecated_command_loop_hook'
 285      should be deprecated.  */
 286   if (deprecated_command_loop_hook != NULL)
 287     deprecated_command_loop_hook ();
 288   else if (current_interpreter != NULL
 289            && current_interpreter->procs->command_loop_proc != NULL)
 290     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 291   else
 292     cli_command_loop ();
 293 }
 294
 295 int
 296 interp_quiet_p (struct interp *interp)
 297 {
 298   if (interp != NULL)
 299     return interp->quiet_p;
 300   else
 301     return current_interpreter->quiet_p;
 302 }
 303
 304 static int
 305 interp_set_quiet (struct interp *interp, int quiet)
 306 {
 307   int old_val = interp->quiet_p;
 308   interp->quiet_p = quiet;
 309   return old_val;
 310 }
 311
 312 /* interp_exec - This executes COMMAND_STR in the current
 313    interpreter. */
 314 int
 315 interp_exec_p (struct interp *interp)
 316 {
 317   return interp->procs->exec_proc != NULL;
 318 }
 319
 320 struct gdb_exception
 321 interp_exec (struct interp *interp, const char *command_str)
 322 {
 323   if (interp->procs->exec_proc != NULL)
 324     {
 325       return interp->procs->exec_proc (interp->data, command_str);
 326     }
 327   return exception_none;
 328 }
 329
 330 /* A convenience routine that nulls out all the common command hooks.
 331    Use it when removing your interpreter in its suspend proc.  */
 332 void
 333 clear_interpreter_hooks (void)
 334 {
 335   deprecated_init_ui_hook = 0;
 336   deprecated_print_frame_info_listing_hook = 0;
 337   /*print_frame_more_info_hook = 0; */
 338   deprecated_query_hook = 0;
 339   deprecated_warning_hook = 0;
 340   deprecated_interactive_hook = 0;
 341   deprecated_readline_begin_hook = 0;
 342   deprecated_readline_hook = 0;
 343   deprecated_readline_end_hook = 0;
 344   deprecated_register_changed_hook = 0;
 345   deprecated_memory_changed_hook = 0;
 346   deprecated_context_hook = 0;
 347   deprecated_target_wait_hook = 0;
 348   deprecated_call_command_hook = 0;
 349   deprecated_error_begin_hook = 0;
 350   deprecated_command_loop_hook = 0;
 351 }
 352
 353 /* This is a lazy init routine, called the first time the interpreter
 354    module is used.  I put it here just in case, but I haven't thought
 355    of a use for it yet.  I will probably bag it soon, since I don't
 356    think it will be necessary.  */
 357 static void
 358 initialize_interps (void)
 359 {
 360   interpreter_initialized = 1;
 361   /* Don't know if anything needs to be done here... */
 362 }
 363
 364 static void
 365 interpreter_exec_cmd (char *args, int from_tty)
 366 {
 367   struct interp *old_interp, *interp_to_use;
 368   char **prules = NULL;
 369   char **trule = NULL;
 370   unsigned int nrules;
 371   unsigned int i;
 372   int old_quiet, use_quiet;
 373
 374   if (args == NULL)
 375     error_no_arg (_("interpreter-exec command"));
 376
 377   prules = gdb_buildargv (args);
 378   make_cleanup_freeargv (prules);
 379
 380   nrules = 0;
 381   for (trule = prules; *trule != NULL; trule++)
 382     nrules++;
 383
 384   if (nrules < 2)
 385     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 386
 387   old_interp = current_interpreter;
 388
 389   interp_to_use = interp_lookup (prules[0]);
 390   if (interp_to_use == NULL)
 391     error (_("Could not find interpreter \"%s\"."), prules[0]);
 392
 393   /* Temporarily set interpreters quiet */
 394   old_quiet = interp_set_quiet (old_interp, 1);
 395   use_quiet = interp_set_quiet (interp_to_use, 1);
 396
 397   if (!interp_set (interp_to_use, 0))
 398     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 399
 400   for (i = 1; i < nrules; i++)
 401     {
 402       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 403       if (e.reason < 0)
 404         {
 405           interp_set (old_interp, 0);
 406           interp_set_quiet (interp_to_use, use_quiet);
 407           interp_set_quiet (old_interp, old_quiet);
 408           error (_("error in command: \"%s\"."), prules[i]);
 409         }
 410     }
 411
 412   interp_set (old_interp, 0);
 413   interp_set_quiet (interp_to_use, use_quiet);
 414   interp_set_quiet (old_interp, old_quiet);
 415 }
 416
 417 /* List the possible interpreters which could complete the given text. */
 418 static char **
 419 interpreter_completer (char *text, char *word)
 420 {
 421   int alloced = 0;
 422   int textlen;
 423   int num_matches;
 424   char **matches;
 425   struct interp *interp;
 426
 427   /* We expect only a very limited number of interpreters, so just
 428      allocate room for all of them plus one for the last that must be NULL
 429      to correctly end the list. */
 430   for (interp = interp_list; interp != NULL; interp = interp->next)
 431     ++alloced;
 432   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 433
 434   num_matches = 0;
 435   textlen = strlen (text);
 436   for (interp = interp_list; interp != NULL; interp = interp->next)
 437     {
 438       if (strncmp (interp->name, text, textlen) == 0)
 439         {
 440           matches[num_matches] =
 441             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 442           if (word == text)
 443             strcpy (matches[num_matches], interp->name);
 444           else if (word > text)
 445             {
 446               /* Return some portion of interp->name */
 447               strcpy (matches[num_matches], interp->name + (word - text));
 448             }
 449           else
 450             {
 451               /* Return some of text plus interp->name */
 452               strncpy (matches[num_matches], word, text - word);
 453               matches[num_matches][text - word] = '\0';
 454               strcat (matches[num_matches], interp->name);
 455             }
 456           ++num_matches;
 457         }
 458     }
 459
 460   if (num_matches == 0)
 461     {
 462       xfree (matches);
 463       matches = NULL;
 464     }
 465
 466   return matches;
 467 }
 468
 469 struct interp *
 470 top_level_interpreter (void)
 471 {
 472   return top_level_interpreter_ptr;
 473 }
 474
 475 void *
 476 top_level_interpreter_data (void)
 477 {
 478   gdb_assert (top_level_interpreter_ptr);
 479   return top_level_interpreter_ptr->data;
 480 }
 481
 482 /* This just adds the "interpreter-exec" command.  */
 483 void
 484 _initialize_interpreter (void)
 485 {
 486   struct cmd_list_element *c;
 487
 488   c = add_cmd ("interpreter-exec", class_support,
 489                interpreter_exec_cmd, _("\
 490 Execute a command in an interpreter.  It takes two arguments:\n\
 491 The first argument is the name of the interpreter to use.\n\
 492 The second argument is the command to execute.\n"), &cmdlist);
 493   set_cmd_completer (c, interpreter_completer);
 494 }