gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2015 Free Software Foundation, Inc.
   4
   5    Written by Jim Ingham <jingham@apple.com> of Apple Computer, Inc.
   6
   7    This file is part of GDB.
   8
   9    This program is free software; you can redistribute it and/or modify
  10    it under the terms of the GNU General Public License as published by
  11    the Free Software Foundation; either version 3 of the License, or
  12    (at your option) any later version.
  13
  14    This program is distributed in the hope that it will be useful,
  15    but WITHOUT ANY WARRANTY; without even the implied warranty of
  16    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  17    GNU General Public License for more details.
  18
  19    You should have received a copy of the GNU General Public License
  20    along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
  21
  22 /* This is just a first cut at separating out the "interpreter"
  23    functions of gdb into self-contained modules.  There are a couple
  24    of open areas that need to be sorted out:
  25
  26    1) The interpreter explicitly contains a UI_OUT, and can insert itself
  27    into the event loop, but it doesn't explicitly contain hooks for readline.
  28    I did this because it seems to me many interpreters won't want to use
  29    the readline command interface, and it is probably simpler to just let
  30    them take over the input in their resume proc.  */
  31
  32 #include "defs.h"
  33 #include "gdbcmd.h"
  34 #include "ui-out.h"
  35 #include "event-loop.h"
  36 #include "event-top.h"
  37 #include "interps.h"
  38 #include "completer.h"
  39 #include "top.h"                /* For command_loop.  */
  40 #include "continuations.h"
  41
  42 /* True if the current interpreter in is async mode.  See interps.h
  43    for more details.  This starts out disabled, until all the explicit
  44    command line arguments (e.g., `gdb -ex "start" -ex "next"') are
  45    processed.  */
  46 int interpreter_async = 0;
  47
  48 struct interp
  49 {
  50   /* This is the name in "-i=" and set interpreter.  */
  51   const char *name;
  52
  53   /* Interpreters are stored in a linked list, this is the next
  54      one...  */
  55   struct interp *next;
  56
  57   /* This is a cookie that an instance of the interpreter can use.
  58      This is a bit confused right now as the exact initialization
  59      sequence for it, and how it relates to the interpreter's uiout
  60      object is a bit confused.  */
  61   void *data;
  62
  63   /* Has the init_proc been run?  */
  64   int inited;
  65
  66   const struct interp_procs *procs;
  67   int quiet_p;
  68 };
  69
  70 /* The magic initialization routine for this module.  */
  71
  72 void _initialize_interpreter (void);
  73
  74 /* Variables local to this file: */
  75
  76 static struct interp *interp_list = NULL;
  77 static struct interp *current_interpreter = NULL;
  78 static struct interp *top_level_interpreter_ptr = NULL;
  79
  80 /* interp_new - This allocates space for a new interpreter,
  81    fills the fields from the inputs, and returns a pointer to the
  82    interpreter.  */
  83 struct interp *
  84 interp_new (const char *name, const struct interp_procs *procs)
  85 {
  86   struct interp *new_interp;
  87
  88   new_interp = XNEW (struct interp);
  89
  90   new_interp->name = xstrdup (name);
  91   new_interp->data = NULL;
  92   new_interp->quiet_p = 0;
  93   new_interp->procs = procs;
  94   new_interp->inited = 0;
  95
  96   /* Check for required procs.  */
  97   gdb_assert (procs->command_loop_proc != NULL);
  98
  99   return new_interp;
 100 }
 101
 102 /* Add interpreter INTERP to the gdb interpreter list.  The
 103    interpreter must not have previously been added.  */
 104 void
 105 interp_add (struct interp *interp)
 106 {
 107   gdb_assert (interp_lookup (interp->name) == NULL);
 108
 109   interp->next = interp_list;
 110   interp_list = interp;
 111 }
 112
 113 /* This sets the current interpreter to be INTERP.  If INTERP has not
 114    been initialized, then this will also run the init proc.  If the
 115    init proc is successful, return 1, if it fails, set the old
 116    interpreter back in place and return 0.  If we can't restore the
 117    old interpreter, then raise an internal error, since we are in
 118    pretty bad shape at this point.
 119
 120    The TOP_LEVEL parameter tells if this new interpreter is
 121    the top-level one.  The top-level is what is requested
 122    on the command line, and is responsible for reporting general
 123    notification about target state changes.  For example, if
 124    MI is the top-level interpreter, then it will always report
 125    events such as target stops and new thread creation, even if they
 126    are caused by CLI commands.  */
 127 int
 128 interp_set (struct interp *interp, int top_level)
 129 {
 130   struct interp *old_interp = current_interpreter;
 131   int first_time = 0;
 132   char buffer[64];
 133
 134   /* If we already have an interpreter, then trying to
 135      set top level interpreter is kinda pointless.  */
 136   gdb_assert (!top_level || !current_interpreter);
 137   gdb_assert (!top_level || !top_level_interpreter_ptr);
 138
 139   if (current_interpreter != NULL)
 140     {
 141       ui_out_flush (current_uiout);
 142       if (current_interpreter->procs->suspend_proc
 143           && !current_interpreter->procs->suspend_proc (current_interpreter->
 144                                                         data))
 145         {
 146           error (_("Could not suspend interpreter \"%s\"."),
 147                  current_interpreter->name);
 148         }
 149     }
 150   else
 151     {
 152       first_time = 1;
 153     }
 154
 155   current_interpreter = interp;
 156   if (top_level)
 157     top_level_interpreter_ptr = interp;
 158
 159   /* We use interpreter_p for the "set interpreter" variable, so we need
 160      to make sure we have a malloc'ed copy for the set command to free.  */
 161   if (interpreter_p != NULL
 162       && strcmp (current_interpreter->name, interpreter_p) != 0)
 163     {
 164       xfree (interpreter_p);
 165
 166       interpreter_p = xstrdup (current_interpreter->name);
 167     }
 168
 169   /* Run the init proc.  If it fails, try to restore the old interp.  */
 170
 171   if (!interp->inited)
 172     {
 173       if (interp->procs->init_proc != NULL)
 174         {
 175           interp->data = interp->procs->init_proc (interp, top_level);
 176         }
 177       interp->inited = 1;
 178     }
 179
 180   /* Do this only after the interpreter is initialized.  */
 181   current_uiout = interp->procs->ui_out_proc (interp);
 182
 183   /* Clear out any installed interpreter hooks/event handlers.  */
 184   clear_interpreter_hooks ();
 185
 186   if (interp->procs->resume_proc != NULL
 187       && (!interp->procs->resume_proc (interp->data)))
 188     {
 189       if (old_interp == NULL || !interp_set (old_interp, 0))
 190         internal_error (__FILE__, __LINE__,
 191                         _("Failed to initialize new interp \"%s\" %s"),
 192                         interp->name, "and could not restore old interp!\n");
 193       return 0;
 194     }
 195
 196   if (!first_time && !interp_quiet_p (interp))
 197     {
 198       xsnprintf (buffer, sizeof (buffer),
 199                  "Switching to interpreter \"%.24s\".\n", interp->name);
 200       ui_out_text (current_uiout, buffer);
 201     }
 202
 203   return 1;
 204 }
 205
 206 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 207    interpreter exists, return NULL, otherwise return a pointer to the
 208    interpreter.  */
 209 struct interp *
 210 interp_lookup (const char *name)
 211 {
 212   struct interp *interp;
 213
 214   if (name == NULL || strlen (name) == 0)
 215     return NULL;
 216
 217   for (interp = interp_list; interp != NULL; interp = interp->next)
 218     {
 219       if (strcmp (interp->name, name) == 0)
 220         return interp;
 221     }
 222
 223   return NULL;
 224 }
 225
 226 /* Returns the current interpreter.  */
 227
 228 struct ui_out *
 229 interp_ui_out (struct interp *interp)
 230 {
 231   if (interp != NULL)
 232     return interp->procs->ui_out_proc (interp);
 233
 234   return current_interpreter->procs->ui_out_proc (current_interpreter);
 235 }
 236
 237 int
 238 current_interp_set_logging (int start_log, struct ui_file *out,
 239                             struct ui_file *logfile)
 240 {
 241   if (current_interpreter == NULL
 242       || current_interpreter->procs->set_logging_proc == NULL)
 243     return 0;
 244
 245   return current_interpreter->procs->set_logging_proc (current_interpreter,
 246                                                        start_log, out,
 247                                                        logfile);
 248 }
 249
 250 /* Temporarily overrides the current interpreter.  */
 251 struct interp *
 252 interp_set_temp (const char *name)
 253 {
 254   struct interp *interp = interp_lookup (name);
 255   struct interp *old_interp = current_interpreter;
 256
 257   if (interp)
 258     current_interpreter = interp;
 259   return old_interp;
 260 }
 261
 262 /* Returns the interpreter's cookie.  */
 263
 264 void *
 265 interp_data (struct interp *interp)
 266 {
 267   return interp->data;
 268 }
 269
 270 /* Returns the interpreter's name.  */
 271
 272 const char *
 273 interp_name (struct interp *interp)
 274 {
 275   return interp->name;
 276 }
 277
 278 /* Returns true if the current interp is the passed in name.  */
 279 int
 280 current_interp_named_p (const char *interp_name)
 281 {
 282   if (current_interpreter)
 283     return (strcmp (current_interpreter->name, interp_name) == 0);
 284
 285   return 0;
 286 }
 287
 288 /* The interpreter that is active while `interp_exec' is active, NULL
 289    at all other times.  */
 290 static struct interp *command_interpreter;
 291
 292 /* The interpreter that was active when a command was executed.
 293    Normally that'd always be CURRENT_INTERPRETER, except that MI's
 294    -interpreter-exec command doesn't actually flip the current
 295    interpreter when running its sub-command.  The
 296    `command_interpreter' global tracks when interp_exec is called
 297    (IOW, when -interpreter-exec is called).  If that is set, it is
 298    INTERP in '-interpreter-exec INTERP "CMD"' or in 'interpreter-exec
 299    INTERP "CMD".  Otherwise, interp_exec isn't active, and so the
 300    interpreter running the command is the current interpreter.  */
 301
 302 struct interp *
 303 command_interp (void)
 304 {
 305   if (command_interpreter != NULL)
 306     return command_interpreter;
 307   else
 308     return current_interpreter;
 309 }
 310
 311 /* Run the current command interpreter's main loop.  */
 312 void
 313 current_interp_command_loop (void)
 314 {
 315   gdb_assert (current_interpreter != NULL);
 316
 317   current_interpreter->procs->command_loop_proc (current_interpreter->data);
 318 }
 319
 320 int
 321 interp_quiet_p (struct interp *interp)
 322 {
 323   if (interp != NULL)
 324     return interp->quiet_p;
 325   else
 326     return current_interpreter->quiet_p;
 327 }
 328
 329 static int
 330 interp_set_quiet (struct interp *interp, int quiet)
 331 {
 332   int old_val = interp->quiet_p;
 333
 334   interp->quiet_p = quiet;
 335   return old_val;
 336 }
 337
 338 /* interp_exec - This executes COMMAND_STR in the current
 339    interpreter.  */
 340
 341 struct gdb_exception
 342 interp_exec (struct interp *interp, const char *command_str)
 343 {
 344   struct gdb_exception ex;
 345   struct interp *save_command_interp;
 346
 347   gdb_assert (interp->procs->exec_proc != NULL);
 348
 349   /* See `command_interp' for why we do this.  */
 350   save_command_interp = command_interpreter;
 351   command_interpreter = interp;
 352
 353   ex = interp->procs->exec_proc (interp->data, command_str);
 354
 355   command_interpreter = save_command_interp;
 356
 357   return ex;
 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 }
 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   struct cleanup *cleanup;
 391
 392   if (args == NULL)
 393     error_no_arg (_("interpreter-exec command"));
 394
 395   prules = gdb_buildargv (args);
 396   cleanup = make_cleanup_freeargv (prules);
 397
 398   nrules = 0;
 399   for (trule = prules; *trule != NULL; trule++)
 400     nrules++;
 401
 402   if (nrules < 2)
 403     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 404
 405   old_interp = current_interpreter;
 406
 407   interp_to_use = interp_lookup (prules[0]);
 408   if (interp_to_use == NULL)
 409     error (_("Could not find interpreter \"%s\"."), prules[0]);
 410
 411   /* Temporarily set interpreters quiet.  */
 412   old_quiet = interp_set_quiet (old_interp, 1);
 413   use_quiet = interp_set_quiet (interp_to_use, 1);
 414
 415   if (!interp_set (interp_to_use, 0))
 416     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 417
 418   for (i = 1; i < nrules; i++)
 419     {
 420       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 421
 422       if (e.reason < 0)
 423         {
 424           interp_set (old_interp, 0);
 425           interp_set_quiet (interp_to_use, use_quiet);
 426           interp_set_quiet (old_interp, old_quiet);
 427           error (_("error in command: \"%s\"."), prules[i]);
 428         }
 429     }
 430
 431   interp_set (old_interp, 0);
 432   interp_set_quiet (interp_to_use, use_quiet);
 433   interp_set_quiet (old_interp, old_quiet);
 434
 435   do_cleanups (cleanup);
 436 }
 437
 438 /* List the possible interpreters which could complete the given text.  */
 439 static VEC (char_ptr) *
 440 interpreter_completer (struct cmd_list_element *ignore,
 441                        const char *text, const char *word)
 442 {
 443   int textlen;
 444   VEC (char_ptr) *matches = NULL;
 445   struct interp *interp;
 446
 447   textlen = strlen (text);
 448   for (interp = interp_list; interp != NULL; interp = interp->next)
 449     {
 450       if (strncmp (interp->name, text, textlen) == 0)
 451         {
 452           char *match;
 453
 454           match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 455           if (word == text)
 456             strcpy (match, interp->name);
 457           else if (word > text)
 458             {
 459               /* Return some portion of interp->name.  */
 460               strcpy (match, interp->name + (word - text));
 461             }
 462           else
 463             {
 464               /* Return some of text plus interp->name.  */
 465               strncpy (match, word, text - word);
 466               match[text - word] = '\0';
 467               strcat (match, interp->name);
 468             }
 469           VEC_safe_push (char_ptr, matches, match);
 470         }
 471     }
 472
 473   return matches;
 474 }
 475
 476 struct interp *
 477 top_level_interpreter (void)
 478 {
 479   return top_level_interpreter_ptr;
 480 }
 481
 482 void *
 483 top_level_interpreter_data (void)
 484 {
 485   gdb_assert (top_level_interpreter_ptr);
 486   return top_level_interpreter_ptr->data;
 487 }
 488
 489 /* This just adds the "interpreter-exec" command.  */
 490 void
 491 _initialize_interpreter (void)
 492 {
 493   struct cmd_list_element *c;
 494
 495   c = add_cmd ("interpreter-exec", class_support,
 496                interpreter_exec_cmd, _("\
 497 Execute a command in an interpreter.  It takes two arguments:\n\
 498 The first argument is the name of the interpreter to use.\n\
 499 The second argument is the command to execute.\n"), &cmdlist);
 500   set_cmd_completer (c, interpreter_completer);
 501 }