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 /* Temporarily overrides the current interpreter.  */
 257 struct interp *
 258 interp_set_temp (const char *name)
 259 {
 260   struct interp *interp = interp_lookup (name);
 261   struct interp *old_interp = current_interpreter;
 262
 263   if (interp)
 264     current_interpreter = interp;
 265   return old_interp;
 266 }
 267
 268 /* Returns the interpreter's cookie.  */
 269
 270 void *
 271 interp_data (struct interp *interp)
 272 {
 273   return interp->data;
 274 }
 275
 276 /* Returns the interpreter's name.  */
 277
 278 const char *
 279 interp_name (struct interp *interp)
 280 {
 281   return interp->name;
 282 }
 283
 284 /* Returns true if the current interp is the passed in name.  */
 285 int
 286 current_interp_named_p (const char *interp_name)
 287 {
 288   if (current_interpreter)
 289     return (strcmp (current_interpreter->name, interp_name) == 0);
 290
 291   return 0;
 292 }
 293
 294 /* This is called in display_gdb_prompt.  If the proc returns a zero
 295    value, display_gdb_prompt will return without displaying the
 296    prompt.  */
 297 int
 298 current_interp_display_prompt_p (void)
 299 {
 300   if (current_interpreter == NULL
 301       || current_interpreter->procs->prompt_proc_p == NULL)
 302     return 0;
 303   else
 304     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 305                                                       data);
 306 }
 307
 308 /* Run the current command interpreter's main loop.  */
 309 void
 310 current_interp_command_loop (void)
 311 {
 312   /* Somewhat messy.  For the moment prop up all the old ways of
 313      selecting the command loop.  `deprecated_command_loop_hook'
 314      should be deprecated.  */
 315   if (deprecated_command_loop_hook != NULL)
 316     deprecated_command_loop_hook ();
 317   else if (current_interpreter != NULL
 318            && current_interpreter->procs->command_loop_proc != NULL)
 319     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 320   else
 321     cli_command_loop ();
 322 }
 323
 324 int
 325 interp_quiet_p (struct interp *interp)
 326 {
 327   if (interp != NULL)
 328     return interp->quiet_p;
 329   else
 330     return current_interpreter->quiet_p;
 331 }
 332
 333 static int
 334 interp_set_quiet (struct interp *interp, int quiet)
 335 {
 336   int old_val = interp->quiet_p;
 337
 338   interp->quiet_p = quiet;
 339   return old_val;
 340 }
 341
 342 /* interp_exec - This executes COMMAND_STR in the current
 343    interpreter.  */
 344 int
 345 interp_exec_p (struct interp *interp)
 346 {
 347   return interp->procs->exec_proc != NULL;
 348 }
 349
 350 struct gdb_exception
 351 interp_exec (struct interp *interp, const char *command_str)
 352 {
 353   if (interp->procs->exec_proc != NULL)
 354     {
 355       return interp->procs->exec_proc (interp->data, command_str);
 356     }
 357   return exception_none;
 358 }
 359
 360 /* A convenience routine that nulls out all the common command hooks.
 361    Use it when removing your interpreter in its suspend proc.  */
 362 void
 363 clear_interpreter_hooks (void)
 364 {
 365   deprecated_init_ui_hook = 0;
 366   deprecated_print_frame_info_listing_hook = 0;
 367   /*print_frame_more_info_hook = 0; */
 368   deprecated_query_hook = 0;
 369   deprecated_warning_hook = 0;
 370   deprecated_interactive_hook = 0;
 371   deprecated_readline_begin_hook = 0;
 372   deprecated_readline_hook = 0;
 373   deprecated_readline_end_hook = 0;
 374   deprecated_register_changed_hook = 0;
 375   deprecated_context_hook = 0;
 376   deprecated_target_wait_hook = 0;
 377   deprecated_call_command_hook = 0;
 378   deprecated_error_begin_hook = 0;
 379   deprecated_command_loop_hook = 0;
 380 }
 381
 382 /* This is a lazy init routine, called the first time the interpreter
 383    module is used.  I put it here just in case, but I haven't thought
 384    of a use for it yet.  I will probably bag it soon, since I don't
 385    think it will be necessary.  */
 386 static void
 387 initialize_interps (void)
 388 {
 389   interpreter_initialized = 1;
 390   /* Don't know if anything needs to be done here...  */
 391 }
 392
 393 static void
 394 interpreter_exec_cmd (char *args, int from_tty)
 395 {
 396   struct interp *old_interp, *interp_to_use;
 397   char **prules = NULL;
 398   char **trule = NULL;
 399   unsigned int nrules;
 400   unsigned int i;
 401   int old_quiet, use_quiet;
 402
 403   if (args == NULL)
 404     error_no_arg (_("interpreter-exec command"));
 405
 406   prules = gdb_buildargv (args);
 407   make_cleanup_freeargv (prules);
 408
 409   nrules = 0;
 410   for (trule = prules; *trule != NULL; trule++)
 411     nrules++;
 412
 413   if (nrules < 2)
 414     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 415
 416   old_interp = current_interpreter;
 417
 418   interp_to_use = interp_lookup (prules[0]);
 419   if (interp_to_use == NULL)
 420     error (_("Could not find interpreter \"%s\"."), prules[0]);
 421
 422   /* Temporarily set interpreters quiet.  */
 423   old_quiet = interp_set_quiet (old_interp, 1);
 424   use_quiet = interp_set_quiet (interp_to_use, 1);
 425
 426   if (!interp_set (interp_to_use, 0))
 427     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 428
 429   for (i = 1; i < nrules; i++)
 430     {
 431       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 432
 433       if (e.reason < 0)
 434         {
 435           interp_set (old_interp, 0);
 436           interp_set_quiet (interp_to_use, use_quiet);
 437           interp_set_quiet (old_interp, old_quiet);
 438           error (_("error in command: \"%s\"."), prules[i]);
 439         }
 440     }
 441
 442   interp_set (old_interp, 0);
 443   interp_set_quiet (interp_to_use, use_quiet);
 444   interp_set_quiet (old_interp, old_quiet);
 445 }
 446
 447 /* List the possible interpreters which could complete the given text.  */
 448 static char **
 449 interpreter_completer (struct cmd_list_element *ignore, char *text, char *word)
 450 {
 451   int alloced = 0;
 452   int textlen;
 453   int num_matches;
 454   char **matches;
 455   struct interp *interp;
 456
 457   /* We expect only a very limited number of interpreters, so just
 458      allocate room for all of them plus one for the last that must be NULL
 459      to correctly end the list.  */
 460   for (interp = interp_list; interp != NULL; interp = interp->next)
 461     ++alloced;
 462   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 463
 464   num_matches = 0;
 465   textlen = strlen (text);
 466   for (interp = interp_list; interp != NULL; interp = interp->next)
 467     {
 468       if (strncmp (interp->name, text, textlen) == 0)
 469         {
 470           matches[num_matches] =
 471             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 472           if (word == text)
 473             strcpy (matches[num_matches], interp->name);
 474           else if (word > text)
 475             {
 476               /* Return some portion of interp->name.  */
 477               strcpy (matches[num_matches], interp->name + (word - text));
 478             }
 479           else
 480             {
 481               /* Return some of text plus interp->name.  */
 482               strncpy (matches[num_matches], word, text - word);
 483               matches[num_matches][text - word] = '\0';
 484               strcat (matches[num_matches], interp->name);
 485             }
 486           ++num_matches;
 487         }
 488     }
 489
 490   if (num_matches == 0)
 491     {
 492       xfree (matches);
 493       matches = NULL;
 494     }
 495
 496   return matches;
 497 }
 498
 499 struct interp *
 500 top_level_interpreter (void)
 501 {
 502   return top_level_interpreter_ptr;
 503 }
 504
 505 void *
 506 top_level_interpreter_data (void)
 507 {
 508   gdb_assert (top_level_interpreter_ptr);
 509   return top_level_interpreter_ptr->data;
 510 }
 511
 512 /* This just adds the "interpreter-exec" command.  */
 513 void
 514 _initialize_interpreter (void)
 515 {
 516   struct cmd_list_element *c;
 517
 518   c = add_cmd ("interpreter-exec", class_support,
 519                interpreter_exec_cmd, _("\
 520 Execute a command in an interpreter.  It takes two arguments:\n\
 521 The first argument is the name of the interpreter to use.\n\
 522 The second argument is the command to execute.\n"), &cmdlist);
 523   set_cmd_completer (c, interpreter_completer);
 524 }