gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2013 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 "gdb_string.h"
  40 #include "gdb_assert.h"
  41 #include "top.h"                /* For command_loop.  */
  42 #include "exceptions.h"
  43 #include "continuations.h"
  44
  45 /* True if the current interpreter in is async mode.  See interps.h
  46    for more details.  This starts out disabled, until all the explicit
  47    command line arguments (e.g., `gdb -ex "start" -ex "next"') are
  48    processed.  */
  49 int interpreter_async = 0;
  50
  51 struct interp
  52 {
  53   /* This is the name in "-i=" and set interpreter.  */
  54   const char *name;
  55
  56   /* Interpreters are stored in a linked list, this is the next
  57      one...  */
  58   struct interp *next;
  59
  60   /* This is a cookie that an instance of the interpreter can use.
  61      This is a bit confused right now as the exact initialization
  62      sequence for it, and how it relates to the interpreter's uiout
  63      object is a bit confused.  */
  64   void *data;
  65
  66   /* Has the init_proc been run?  */
  67   int inited;
  68
  69   const struct interp_procs *procs;
  70   int quiet_p;
  71 };
  72
  73 /* Functions local to this file.  */
  74 static void initialize_interps (void);
  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, const struct interp_procs *procs)
  93 {
  94   struct interp *new_interp;
  95
  96   new_interp = XMALLOC (struct interp);
  97
  98   new_interp->name = xstrdup (name);
  99   new_interp->data = NULL;
 100   new_interp->quiet_p = 0;
 101   new_interp->procs = procs;
 102   new_interp->inited = 0;
 103
 104   return new_interp;
 105 }
 106
 107 /* Add interpreter INTERP to the gdb interpreter list.  The
 108    interpreter must not have previously been added.  */
 109 void
 110 interp_add (struct interp *interp)
 111 {
 112   if (!interpreter_initialized)
 113     initialize_interps ();
 114
 115   gdb_assert (interp_lookup (interp->name) == NULL);
 116
 117   interp->next = interp_list;
 118   interp_list = interp;
 119 }
 120
 121 /* This sets the current interpreter to be INTERP.  If INTERP has not
 122    been initialized, then this will also run the init proc.  If the
 123    init proc is successful, return 1, if it fails, set the old
 124    interpreter back in place and return 0.  If we can't restore the
 125    old interpreter, then raise an internal error, since we are in
 126    pretty bad shape at this point.
 127
 128    The TOP_LEVEL parameter tells if this new interpreter is
 129    the top-level one.  The top-level is what is requested
 130    on the command line, and is responsible for reporting general
 131    notification about target state changes.  For example, if
 132    MI is the top-level interpreter, then it will always report
 133    events such as target stops and new thread creation, even if they
 134    are caused by CLI commands.  */
 135 int
 136 interp_set (struct interp *interp, int top_level)
 137 {
 138   struct interp *old_interp = current_interpreter;
 139   int first_time = 0;
 140   char buffer[64];
 141
 142   /* If we already have an interpreter, then trying to
 143      set top level interpreter is kinda pointless.  */
 144   gdb_assert (!top_level || !current_interpreter);
 145   gdb_assert (!top_level || !top_level_interpreter_ptr);
 146
 147   if (current_interpreter != NULL)
 148     {
 149       ui_out_flush (current_uiout);
 150       if (current_interpreter->procs->suspend_proc
 151           && !current_interpreter->procs->suspend_proc (current_interpreter->
 152                                                         data))
 153         {
 154           error (_("Could not suspend interpreter \"%s\"."),
 155                  current_interpreter->name);
 156         }
 157     }
 158   else
 159     {
 160       first_time = 1;
 161     }
 162
 163   current_interpreter = interp;
 164   if (top_level)
 165     top_level_interpreter_ptr = interp;
 166
 167   /* We use interpreter_p for the "set interpreter" variable, so we need
 168      to make sure we have a malloc'ed copy for the set command to free.  */
 169   if (interpreter_p != NULL
 170       && strcmp (current_interpreter->name, interpreter_p) != 0)
 171     {
 172       xfree (interpreter_p);
 173
 174       interpreter_p = xstrdup (current_interpreter->name);
 175     }
 176
 177   /* Run the init proc.  If it fails, try to restore the old interp.  */
 178
 179   if (!interp->inited)
 180     {
 181       if (interp->procs->init_proc != NULL)
 182         {
 183           interp->data = interp->procs->init_proc (interp, top_level);
 184         }
 185       interp->inited = 1;
 186     }
 187
 188   /* Do this only after the interpreter is initialized.  */
 189   current_uiout = interp->procs->ui_out_proc (interp);
 190
 191   /* Clear out any installed interpreter hooks/event handlers.  */
 192   clear_interpreter_hooks ();
 193
 194   if (interp->procs->resume_proc != NULL
 195       && (!interp->procs->resume_proc (interp->data)))
 196     {
 197       if (old_interp == NULL || !interp_set (old_interp, 0))
 198         internal_error (__FILE__, __LINE__,
 199                         _("Failed to initialize new interp \"%s\" %s"),
 200                         interp->name, "and could not restore old interp!\n");
 201       return 0;
 202     }
 203
 204   /* Finally, put up the new prompt to show that we are indeed here.
 205      Also, display_gdb_prompt for the console does some readline magic
 206      which is needed for the console interpreter, at least...  */
 207
 208   if (!first_time)
 209     {
 210       if (!interp_quiet_p (interp))
 211         {
 212           xsnprintf (buffer, sizeof (buffer),
 213                      "Switching to interpreter \"%.24s\".\n", interp->name);
 214           ui_out_text (current_uiout, buffer);
 215         }
 216       display_gdb_prompt (NULL);
 217     }
 218
 219   return 1;
 220 }
 221
 222 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 223    interpreter exists, return NULL, otherwise return a pointer to the
 224    interpreter.  */
 225 struct interp *
 226 interp_lookup (const char *name)
 227 {
 228   struct interp *interp;
 229
 230   if (name == NULL || strlen (name) == 0)
 231     return NULL;
 232
 233   for (interp = interp_list; interp != NULL; interp = interp->next)
 234     {
 235       if (strcmp (interp->name, name) == 0)
 236         return interp;
 237     }
 238
 239   return NULL;
 240 }
 241
 242 /* Returns the current interpreter.  */
 243
 244 struct ui_out *
 245 interp_ui_out (struct interp *interp)
 246 {
 247   if (interp != NULL)
 248     return interp->procs->ui_out_proc (interp);
 249
 250   return current_interpreter->procs->ui_out_proc (current_interpreter);
 251 }
 252
 253 int
 254 current_interp_set_logging (int start_log, struct ui_file *out,
 255                             struct ui_file *logfile)
 256 {
 257   if (current_interpreter == NULL
 258       || current_interpreter->procs->set_logging_proc == NULL)
 259     return 0;
 260
 261   return current_interpreter->procs->set_logging_proc (current_interpreter,
 262                                                        start_log, out,
 263                                                        logfile);
 264 }
 265
 266 /* Temporarily overrides the current interpreter.  */
 267 struct interp *
 268 interp_set_temp (const char *name)
 269 {
 270   struct interp *interp = interp_lookup (name);
 271   struct interp *old_interp = current_interpreter;
 272
 273   if (interp)
 274     current_interpreter = interp;
 275   return old_interp;
 276 }
 277
 278 /* Returns the interpreter's cookie.  */
 279
 280 void *
 281 interp_data (struct interp *interp)
 282 {
 283   return interp->data;
 284 }
 285
 286 /* Returns the interpreter's name.  */
 287
 288 const char *
 289 interp_name (struct interp *interp)
 290 {
 291   return interp->name;
 292 }
 293
 294 /* Returns true if the current interp is the passed in name.  */
 295 int
 296 current_interp_named_p (const char *interp_name)
 297 {
 298   if (current_interpreter)
 299     return (strcmp (current_interpreter->name, interp_name) == 0);
 300
 301   return 0;
 302 }
 303
 304 /* This is called in display_gdb_prompt.  If the proc returns a zero
 305    value, display_gdb_prompt will return without displaying the
 306    prompt.  */
 307 int
 308 current_interp_display_prompt_p (void)
 309 {
 310   if (current_interpreter == NULL
 311       || current_interpreter->procs->prompt_proc_p == NULL)
 312     return 0;
 313   else
 314     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 315                                                       data);
 316 }
 317
 318 /* Run the current command interpreter's main loop.  */
 319 void
 320 current_interp_command_loop (void)
 321 {
 322   /* Somewhat messy.  For the moment prop up all the old ways of
 323      selecting the command loop.  */
 324   if (current_interpreter != NULL
 325       && current_interpreter->procs->command_loop_proc != NULL)
 326     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 327   else
 328     cli_command_loop ();
 329 }
 330
 331 int
 332 interp_quiet_p (struct interp *interp)
 333 {
 334   if (interp != NULL)
 335     return interp->quiet_p;
 336   else
 337     return current_interpreter->quiet_p;
 338 }
 339
 340 static int
 341 interp_set_quiet (struct interp *interp, int quiet)
 342 {
 343   int old_val = interp->quiet_p;
 344
 345   interp->quiet_p = quiet;
 346   return old_val;
 347 }
 348
 349 /* interp_exec - This executes COMMAND_STR in the current
 350    interpreter.  */
 351 int
 352 interp_exec_p (struct interp *interp)
 353 {
 354   return interp->procs->exec_proc != NULL;
 355 }
 356
 357 struct gdb_exception
 358 interp_exec (struct interp *interp, const char *command_str)
 359 {
 360   if (interp->procs->exec_proc != NULL)
 361     {
 362       return interp->procs->exec_proc (interp->data, command_str);
 363     }
 364   return exception_none;
 365 }
 366
 367 /* A convenience routine that nulls out all the common command hooks.
 368    Use it when removing your interpreter in its suspend proc.  */
 369 void
 370 clear_interpreter_hooks (void)
 371 {
 372   deprecated_init_ui_hook = 0;
 373   deprecated_print_frame_info_listing_hook = 0;
 374   /*print_frame_more_info_hook = 0; */
 375   deprecated_query_hook = 0;
 376   deprecated_warning_hook = 0;
 377   deprecated_interactive_hook = 0;
 378   deprecated_readline_begin_hook = 0;
 379   deprecated_readline_hook = 0;
 380   deprecated_readline_end_hook = 0;
 381   deprecated_register_changed_hook = 0;
 382   deprecated_context_hook = 0;
 383   deprecated_target_wait_hook = 0;
 384   deprecated_call_command_hook = 0;
 385   deprecated_error_begin_hook = 0;
 386 }
 387
 388 /* This is a lazy init routine, called the first time the interpreter
 389    module is used.  I put it here just in case, but I haven't thought
 390    of a use for it yet.  I will probably bag it soon, since I don't
 391    think it will be necessary.  */
 392 static void
 393 initialize_interps (void)
 394 {
 395   interpreter_initialized = 1;
 396   /* Don't know if anything needs to be done here...  */
 397 }
 398
 399 static void
 400 interpreter_exec_cmd (char *args, int from_tty)
 401 {
 402   struct interp *old_interp, *interp_to_use;
 403   char **prules = NULL;
 404   char **trule = NULL;
 405   unsigned int nrules;
 406   unsigned int i;
 407   int old_quiet, use_quiet;
 408   struct cleanup *cleanup;
 409
 410   if (args == NULL)
 411     error_no_arg (_("interpreter-exec command"));
 412
 413   prules = gdb_buildargv (args);
 414   cleanup = make_cleanup_freeargv (prules);
 415
 416   nrules = 0;
 417   for (trule = prules; *trule != NULL; trule++)
 418     nrules++;
 419
 420   if (nrules < 2)
 421     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 422
 423   old_interp = current_interpreter;
 424
 425   interp_to_use = interp_lookup (prules[0]);
 426   if (interp_to_use == NULL)
 427     error (_("Could not find interpreter \"%s\"."), prules[0]);
 428
 429   /* Temporarily set interpreters quiet.  */
 430   old_quiet = interp_set_quiet (old_interp, 1);
 431   use_quiet = interp_set_quiet (interp_to_use, 1);
 432
 433   if (!interp_set (interp_to_use, 0))
 434     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 435
 436   for (i = 1; i < nrules; i++)
 437     {
 438       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 439
 440       if (e.reason < 0)
 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           error (_("error in command: \"%s\"."), prules[i]);
 446         }
 447     }
 448
 449   interp_set (old_interp, 0);
 450   interp_set_quiet (interp_to_use, use_quiet);
 451   interp_set_quiet (old_interp, old_quiet);
 452
 453   do_cleanups (cleanup);
 454 }
 455
 456 /* List the possible interpreters which could complete the given text.  */
 457 static VEC (char_ptr) *
 458 interpreter_completer (struct cmd_list_element *ignore,
 459                        const char *text, const char *word)
 460 {
 461   int textlen;
 462   VEC (char_ptr) *matches = NULL;
 463   struct interp *interp;
 464
 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           char *match;
 471
 472           match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 473           if (word == text)
 474             strcpy (match, interp->name);
 475           else if (word > text)
 476             {
 477               /* Return some portion of interp->name.  */
 478               strcpy (match, interp->name + (word - text));
 479             }
 480           else
 481             {
 482               /* Return some of text plus interp->name.  */
 483               strncpy (match, word, text - word);
 484               match[text - word] = '\0';
 485               strcat (match, interp->name);
 486             }
 487           VEC_safe_push (char_ptr, matches, match);
 488         }
 489     }
 490
 491   return matches;
 492 }
 493
 494 struct interp *
 495 top_level_interpreter (void)
 496 {
 497   return top_level_interpreter_ptr;
 498 }
 499
 500 void *
 501 top_level_interpreter_data (void)
 502 {
 503   gdb_assert (top_level_interpreter_ptr);
 504   return top_level_interpreter_ptr->data;
 505 }
 506
 507 /* This just adds the "interpreter-exec" command.  */
 508 void
 509 _initialize_interpreter (void)
 510 {
 511   struct cmd_list_element *c;
 512
 513   c = add_cmd ("interpreter-exec", class_support,
 514                interpreter_exec_cmd, _("\
 515 Execute a command in an interpreter.  It takes two arguments:\n\
 516 The first argument is the name of the interpreter to use.\n\
 517 The second argument is the command to execute.\n"), &cmdlist);
 518   set_cmd_completer (c, interpreter_completer);
 519 }