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 <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   /* Check for required procs.  */
 105   gdb_assert (procs->command_loop_proc != NULL);
 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           xsnprintf (buffer, sizeof (buffer),
 216                      "Switching to interpreter \"%.24s\".\n", 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 int
 257 current_interp_set_logging (int start_log, struct ui_file *out,
 258                             struct ui_file *logfile)
 259 {
 260   if (current_interpreter == NULL
 261       || current_interpreter->procs->set_logging_proc == NULL)
 262     return 0;
 263
 264   return current_interpreter->procs->set_logging_proc (current_interpreter,
 265                                                        start_log, out,
 266                                                        logfile);
 267 }
 268
 269 /* Temporarily overrides the current interpreter.  */
 270 struct interp *
 271 interp_set_temp (const char *name)
 272 {
 273   struct interp *interp = interp_lookup (name);
 274   struct interp *old_interp = current_interpreter;
 275
 276   if (interp)
 277     current_interpreter = interp;
 278   return old_interp;
 279 }
 280
 281 /* Returns the interpreter's cookie.  */
 282
 283 void *
 284 interp_data (struct interp *interp)
 285 {
 286   return interp->data;
 287 }
 288
 289 /* Returns the interpreter's name.  */
 290
 291 const char *
 292 interp_name (struct interp *interp)
 293 {
 294   return interp->name;
 295 }
 296
 297 /* Returns true if the current interp is the passed in name.  */
 298 int
 299 current_interp_named_p (const char *interp_name)
 300 {
 301   if (current_interpreter)
 302     return (strcmp (current_interpreter->name, interp_name) == 0);
 303
 304   return 0;
 305 }
 306
 307 /* This is called in display_gdb_prompt.  If the proc returns a zero
 308    value, display_gdb_prompt will return without displaying the
 309    prompt.  */
 310 int
 311 current_interp_display_prompt_p (void)
 312 {
 313   if (current_interpreter == NULL
 314       || current_interpreter->procs->prompt_proc_p == NULL)
 315     return 0;
 316   else
 317     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 318                                                       data);
 319 }
 320
 321 /* Run the current command interpreter's main loop.  */
 322 void
 323 current_interp_command_loop (void)
 324 {
 325   gdb_assert (current_interpreter != NULL);
 326
 327   current_interpreter->procs->command_loop_proc (current_interpreter->data);
 328 }
 329
 330 int
 331 interp_quiet_p (struct interp *interp)
 332 {
 333   if (interp != NULL)
 334     return interp->quiet_p;
 335   else
 336     return current_interpreter->quiet_p;
 337 }
 338
 339 static int
 340 interp_set_quiet (struct interp *interp, int quiet)
 341 {
 342   int old_val = interp->quiet_p;
 343
 344   interp->quiet_p = quiet;
 345   return old_val;
 346 }
 347
 348 /* interp_exec - This executes COMMAND_STR in the current
 349    interpreter.  */
 350
 351 struct gdb_exception
 352 interp_exec (struct interp *interp, const char *command_str)
 353 {
 354   gdb_assert (interp->procs->exec_proc != NULL);
 355
 356   return interp->procs->exec_proc (interp->data, command_str);
 357 }
 358
 359 /* A convenience routine that nulls out all the common command hooks.
 360    Use it when removing your interpreter in its suspend proc.  */
 361 void
 362 clear_interpreter_hooks (void)
 363 {
 364   deprecated_init_ui_hook = 0;
 365   deprecated_print_frame_info_listing_hook = 0;
 366   /*print_frame_more_info_hook = 0; */
 367   deprecated_query_hook = 0;
 368   deprecated_warning_hook = 0;
 369   deprecated_interactive_hook = 0;
 370   deprecated_readline_begin_hook = 0;
 371   deprecated_readline_hook = 0;
 372   deprecated_readline_end_hook = 0;
 373   deprecated_register_changed_hook = 0;
 374   deprecated_context_hook = 0;
 375   deprecated_target_wait_hook = 0;
 376   deprecated_call_command_hook = 0;
 377   deprecated_error_begin_hook = 0;
 378 }
 379
 380 /* This is a lazy init routine, called the first time the interpreter
 381    module is used.  I put it here just in case, but I haven't thought
 382    of a use for it yet.  I will probably bag it soon, since I don't
 383    think it will be necessary.  */
 384 static void
 385 initialize_interps (void)
 386 {
 387   interpreter_initialized = 1;
 388   /* Don't know if anything needs to be done here...  */
 389 }
 390
 391 static void
 392 interpreter_exec_cmd (char *args, int from_tty)
 393 {
 394   struct interp *old_interp, *interp_to_use;
 395   char **prules = NULL;
 396   char **trule = NULL;
 397   unsigned int nrules;
 398   unsigned int i;
 399   int old_quiet, use_quiet;
 400   struct cleanup *cleanup;
 401
 402   if (args == NULL)
 403     error_no_arg (_("interpreter-exec command"));
 404
 405   prules = gdb_buildargv (args);
 406   cleanup = make_cleanup_freeargv (prules);
 407
 408   nrules = 0;
 409   for (trule = prules; *trule != NULL; trule++)
 410     nrules++;
 411
 412   if (nrules < 2)
 413     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 414
 415   old_interp = current_interpreter;
 416
 417   interp_to_use = interp_lookup (prules[0]);
 418   if (interp_to_use == NULL)
 419     error (_("Could not find interpreter \"%s\"."), prules[0]);
 420
 421   /* Temporarily set interpreters quiet.  */
 422   old_quiet = interp_set_quiet (old_interp, 1);
 423   use_quiet = interp_set_quiet (interp_to_use, 1);
 424
 425   if (!interp_set (interp_to_use, 0))
 426     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 427
 428   for (i = 1; i < nrules; i++)
 429     {
 430       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 431
 432       if (e.reason < 0)
 433         {
 434           interp_set (old_interp, 0);
 435           interp_set_quiet (interp_to_use, use_quiet);
 436           interp_set_quiet (old_interp, old_quiet);
 437           error (_("error in command: \"%s\"."), prules[i]);
 438         }
 439     }
 440
 441   interp_set (old_interp, 0);
 442   interp_set_quiet (interp_to_use, use_quiet);
 443   interp_set_quiet (old_interp, old_quiet);
 444
 445   do_cleanups (cleanup);
 446 }
 447
 448 /* List the possible interpreters which could complete the given text.  */
 449 static VEC (char_ptr) *
 450 interpreter_completer (struct cmd_list_element *ignore,
 451                        const char *text, const char *word)
 452 {
 453   int textlen;
 454   VEC (char_ptr) *matches = NULL;
 455   struct interp *interp;
 456
 457   textlen = strlen (text);
 458   for (interp = interp_list; interp != NULL; interp = interp->next)
 459     {
 460       if (strncmp (interp->name, text, textlen) == 0)
 461         {
 462           char *match;
 463
 464           match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 465           if (word == text)
 466             strcpy (match, interp->name);
 467           else if (word > text)
 468             {
 469               /* Return some portion of interp->name.  */
 470               strcpy (match, interp->name + (word - text));
 471             }
 472           else
 473             {
 474               /* Return some of text plus interp->name.  */
 475               strncpy (match, word, text - word);
 476               match[text - word] = '\0';
 477               strcat (match, interp->name);
 478             }
 479           VEC_safe_push (char_ptr, matches, match);
 480         }
 481     }
 482
 483   return matches;
 484 }
 485
 486 struct interp *
 487 top_level_interpreter (void)
 488 {
 489   return top_level_interpreter_ptr;
 490 }
 491
 492 void *
 493 top_level_interpreter_data (void)
 494 {
 495   gdb_assert (top_level_interpreter_ptr);
 496   return top_level_interpreter_ptr->data;
 497 }
 498
 499 /* This just adds the "interpreter-exec" command.  */
 500 void
 501 _initialize_interpreter (void)
 502 {
 503   struct cmd_list_element *c;
 504
 505   c = add_cmd ("interpreter-exec", class_support,
 506                interpreter_exec_cmd, _("\
 507 Execute a command in an interpreter.  It takes two arguments:\n\
 508 The first argument is the name of the interpreter to use.\n\
 509 The second argument is the command to execute.\n"), &cmdlist);
 510   set_cmd_completer (c, interpreter_completer);
 511 }