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
  77 /* The magic initialization routine for this module.  */
  78
  79 void _initialize_interpreter (void);
  80
  81 /* Variables local to this file: */
  82
  83 static struct interp *interp_list = NULL;
  84 static struct interp *current_interpreter = NULL;
  85 static struct interp *top_level_interpreter_ptr = NULL;
  86
  87 static int interpreter_initialized = 0;
  88
  89 /* interp_new - This allocates space for a new interpreter,
  90    fills the fields from the inputs, and returns a pointer to the
  91    interpreter.  */
  92 struct interp *
  93 interp_new (const char *name, 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 = NULL;
 101   new_interp->quiet_p = 0;
 102   new_interp->procs = procs;
 103   new_interp->inited = 0;
 104
 105   return new_interp;
 106 }
 107
 108 /* Add interpreter INTERP to the gdb interpreter list.  The
 109    interpreter must not have previously been added.  */
 110 void
 111 interp_add (struct interp *interp)
 112 {
 113   if (!interpreter_initialized)
 114     initialize_interps ();
 115
 116   gdb_assert (interp_lookup (interp->name) == NULL);
 117
 118   interp->next = interp_list;
 119   interp_list = interp;
 120 }
 121
 122 /* This sets the current interpreter to be INTERP.  If INTERP has not
 123    been initialized, then this will also run the init proc.  If the
 124    init proc is successful, return 1, if it fails, set the old
 125    interpreter back in place and return 0.  If we can't restore the
 126    old interpreter, then raise an internal error, since we are in
 127    pretty bad shape at this point.
 128
 129    The TOP_LEVEL parameter tells if this new interpreter is
 130    the top-level one.  The top-level is what is requested
 131    on the command line, and is responsible for reporting general
 132    notification about target state changes.  For example, if
 133    MI is the top-level interpreter, then it will always report
 134    events such as target stops and new thread creation, even if they
 135    are caused by CLI commands.  */
 136 int
 137 interp_set (struct interp *interp, int top_level)
 138 {
 139   struct interp *old_interp = current_interpreter;
 140   int first_time = 0;
 141   char buffer[64];
 142
 143   /* If we already have an interpreter, then trying to
 144      set top level interpreter is kinda pointless.  */
 145   gdb_assert (!top_level || !current_interpreter);
 146   gdb_assert (!top_level || !top_level_interpreter_ptr);
 147
 148   if (current_interpreter != NULL)
 149     {
 150       ui_out_flush (current_uiout);
 151       if (current_interpreter->procs->suspend_proc
 152           && !current_interpreter->procs->suspend_proc (current_interpreter->
 153                                                         data))
 154         {
 155           error (_("Could not suspend interpreter \"%s\"."),
 156                  current_interpreter->name);
 157         }
 158     }
 159   else
 160     {
 161       first_time = 1;
 162     }
 163
 164   current_interpreter = interp;
 165   if (top_level)
 166     top_level_interpreter_ptr = interp;
 167
 168   /* We use interpreter_p for the "set interpreter" variable, so we need
 169      to make sure we have a malloc'ed copy for the set command to free.  */
 170   if (interpreter_p != NULL
 171       && strcmp (current_interpreter->name, interpreter_p) != 0)
 172     {
 173       xfree (interpreter_p);
 174
 175       interpreter_p = xstrdup (current_interpreter->name);
 176     }
 177
 178   /* Run the init proc.  If it fails, try to restore the old interp.  */
 179
 180   if (!interp->inited)
 181     {
 182       if (interp->procs->init_proc != NULL)
 183         {
 184           interp->data = interp->procs->init_proc (interp, top_level);
 185         }
 186       interp->inited = 1;
 187     }
 188
 189   /* Do this only after the interpreter is initialized.  */
 190   current_uiout = interp->procs->ui_out_proc (interp);
 191
 192   /* Clear out any installed interpreter hooks/event handlers.  */
 193   clear_interpreter_hooks ();
 194
 195   if (interp->procs->resume_proc != NULL
 196       && (!interp->procs->resume_proc (interp->data)))
 197     {
 198       if (old_interp == NULL || !interp_set (old_interp, 0))
 199         internal_error (__FILE__, __LINE__,
 200                         _("Failed to initialize new interp \"%s\" %s"),
 201                         interp->name, "and could not restore old interp!\n");
 202       return 0;
 203     }
 204
 205   /* Finally, put up the new prompt to show that we are indeed here.
 206      Also, display_gdb_prompt for the console does some readline magic
 207      which is needed for the console interpreter, at least...  */
 208
 209   if (!first_time)
 210     {
 211       if (!interp_quiet_p (interp))
 212         {
 213           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 214                    interp->name);
 215           ui_out_text (current_uiout, buffer);
 216         }
 217       display_gdb_prompt (NULL);
 218     }
 219
 220   return 1;
 221 }
 222
 223 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 224    interpreter exists, return NULL, otherwise return a pointer to the
 225    interpreter.  */
 226 struct interp *
 227 interp_lookup (const char *name)
 228 {
 229   struct interp *interp;
 230
 231   if (name == NULL || strlen (name) == 0)
 232     return NULL;
 233
 234   for (interp = interp_list; interp != NULL; interp = interp->next)
 235     {
 236       if (strcmp (interp->name, name) == 0)
 237         return interp;
 238     }
 239
 240   return NULL;
 241 }
 242
 243 /* Returns the current interpreter.  */
 244
 245 struct ui_out *
 246 interp_ui_out (struct interp *interp)
 247 {
 248   if (interp != NULL)
 249     return interp->procs->ui_out_proc (interp);
 250
 251   return current_interpreter->procs->ui_out_proc (current_interpreter);
 252 }
 253
 254 int
 255 current_interp_set_logging (int start_log, struct ui_file *out,
 256                             struct ui_file *logfile)
 257 {
 258   if (current_interpreter == NULL
 259       || current_interpreter->procs->set_logging_proc == NULL)
 260     return 0;
 261
 262   return current_interpreter->procs->set_logging_proc (current_interpreter,
 263                                                        start_log, out,
 264                                                        logfile);
 265 }
 266
 267 /* Temporarily overrides the current interpreter.  */
 268 struct interp *
 269 interp_set_temp (const char *name)
 270 {
 271   struct interp *interp = interp_lookup (name);
 272   struct interp *old_interp = current_interpreter;
 273
 274   if (interp)
 275     current_interpreter = interp;
 276   return old_interp;
 277 }
 278
 279 /* Returns the interpreter's cookie.  */
 280
 281 void *
 282 interp_data (struct interp *interp)
 283 {
 284   return interp->data;
 285 }
 286
 287 /* Returns the interpreter's name.  */
 288
 289 const char *
 290 interp_name (struct interp *interp)
 291 {
 292   return interp->name;
 293 }
 294
 295 /* Returns true if the current interp is the passed in name.  */
 296 int
 297 current_interp_named_p (const char *interp_name)
 298 {
 299   if (current_interpreter)
 300     return (strcmp (current_interpreter->name, interp_name) == 0);
 301
 302   return 0;
 303 }
 304
 305 /* This is called in display_gdb_prompt.  If the proc returns a zero
 306    value, display_gdb_prompt will return without displaying the
 307    prompt.  */
 308 int
 309 current_interp_display_prompt_p (void)
 310 {
 311   if (current_interpreter == NULL
 312       || current_interpreter->procs->prompt_proc_p == NULL)
 313     return 0;
 314   else
 315     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 316                                                       data);
 317 }
 318
 319 /* Run the current command interpreter's main loop.  */
 320 void
 321 current_interp_command_loop (void)
 322 {
 323   /* Somewhat messy.  For the moment prop up all the old ways of
 324      selecting the command loop.  `deprecated_command_loop_hook'
 325      should be deprecated.  */
 326   if (deprecated_command_loop_hook != NULL)
 327     deprecated_command_loop_hook ();
 328   else if (current_interpreter != NULL
 329            && current_interpreter->procs->command_loop_proc != NULL)
 330     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 331   else
 332     cli_command_loop ();
 333 }
 334
 335 int
 336 interp_quiet_p (struct interp *interp)
 337 {
 338   if (interp != NULL)
 339     return interp->quiet_p;
 340   else
 341     return current_interpreter->quiet_p;
 342 }
 343
 344 static int
 345 interp_set_quiet (struct interp *interp, int quiet)
 346 {
 347   int old_val = interp->quiet_p;
 348
 349   interp->quiet_p = quiet;
 350   return old_val;
 351 }
 352
 353 /* interp_exec - This executes COMMAND_STR in the current
 354    interpreter.  */
 355 int
 356 interp_exec_p (struct interp *interp)
 357 {
 358   return interp->procs->exec_proc != NULL;
 359 }
 360
 361 struct gdb_exception
 362 interp_exec (struct interp *interp, const char *command_str)
 363 {
 364   if (interp->procs->exec_proc != NULL)
 365     {
 366       return interp->procs->exec_proc (interp->data, command_str);
 367     }
 368   return exception_none;
 369 }
 370
 371 /* A convenience routine that nulls out all the common command hooks.
 372    Use it when removing your interpreter in its suspend proc.  */
 373 void
 374 clear_interpreter_hooks (void)
 375 {
 376   deprecated_init_ui_hook = 0;
 377   deprecated_print_frame_info_listing_hook = 0;
 378   /*print_frame_more_info_hook = 0; */
 379   deprecated_query_hook = 0;
 380   deprecated_warning_hook = 0;
 381   deprecated_interactive_hook = 0;
 382   deprecated_readline_begin_hook = 0;
 383   deprecated_readline_hook = 0;
 384   deprecated_readline_end_hook = 0;
 385   deprecated_register_changed_hook = 0;
 386   deprecated_context_hook = 0;
 387   deprecated_target_wait_hook = 0;
 388   deprecated_call_command_hook = 0;
 389   deprecated_error_begin_hook = 0;
 390   deprecated_command_loop_hook = 0;
 391 }
 392
 393 /* This is a lazy init routine, called the first time the interpreter
 394    module is used.  I put it here just in case, but I haven't thought
 395    of a use for it yet.  I will probably bag it soon, since I don't
 396    think it will be necessary.  */
 397 static void
 398 initialize_interps (void)
 399 {
 400   interpreter_initialized = 1;
 401   /* Don't know if anything needs to be done here...  */
 402 }
 403
 404 static void
 405 interpreter_exec_cmd (char *args, int from_tty)
 406 {
 407   struct interp *old_interp, *interp_to_use;
 408   char **prules = NULL;
 409   char **trule = NULL;
 410   unsigned int nrules;
 411   unsigned int i;
 412   int old_quiet, use_quiet;
 413
 414   if (args == NULL)
 415     error_no_arg (_("interpreter-exec command"));
 416
 417   prules = gdb_buildargv (args);
 418   make_cleanup_freeargv (prules);
 419
 420   nrules = 0;
 421   for (trule = prules; *trule != NULL; trule++)
 422     nrules++;
 423
 424   if (nrules < 2)
 425     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 426
 427   old_interp = current_interpreter;
 428
 429   interp_to_use = interp_lookup (prules[0]);
 430   if (interp_to_use == NULL)
 431     error (_("Could not find interpreter \"%s\"."), prules[0]);
 432
 433   /* Temporarily set interpreters quiet.  */
 434   old_quiet = interp_set_quiet (old_interp, 1);
 435   use_quiet = interp_set_quiet (interp_to_use, 1);
 436
 437   if (!interp_set (interp_to_use, 0))
 438     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 439
 440   for (i = 1; i < nrules; i++)
 441     {
 442       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 443
 444       if (e.reason < 0)
 445         {
 446           interp_set (old_interp, 0);
 447           interp_set_quiet (interp_to_use, use_quiet);
 448           interp_set_quiet (old_interp, old_quiet);
 449           error (_("error in command: \"%s\"."), prules[i]);
 450         }
 451     }
 452
 453   interp_set (old_interp, 0);
 454   interp_set_quiet (interp_to_use, use_quiet);
 455   interp_set_quiet (old_interp, old_quiet);
 456 }
 457
 458 /* List the possible interpreters which could complete the given text.  */
 459 static VEC (char_ptr) *
 460 interpreter_completer (struct cmd_list_element *ignore, char *text, char *word)
 461 {
 462   int textlen;
 463   VEC (char_ptr) *matches = NULL;
 464   struct interp *interp;
 465
 466   textlen = strlen (text);
 467   for (interp = interp_list; interp != NULL; interp = interp->next)
 468     {
 469       if (strncmp (interp->name, text, textlen) == 0)
 470         {
 471           char *match;
 472
 473           match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 474           if (word == text)
 475             strcpy (match, interp->name);
 476           else if (word > text)
 477             {
 478               /* Return some portion of interp->name.  */
 479               strcpy (match, interp->name + (word - text));
 480             }
 481           else
 482             {
 483               /* Return some of text plus interp->name.  */
 484               strncpy (match, word, text - word);
 485               match[text - word] = '\0';
 486               strcat (match, interp->name);
 487             }
 488           VEC_safe_push (char_ptr, matches, match);
 489         }
 490     }
 491
 492   return matches;
 493 }
 494
 495 struct interp *
 496 top_level_interpreter (void)
 497 {
 498   return top_level_interpreter_ptr;
 499 }
 500
 501 void *
 502 top_level_interpreter_data (void)
 503 {
 504   gdb_assert (top_level_interpreter_ptr);
 505   return top_level_interpreter_ptr->data;
 506 }
 507
 508 /* This just adds the "interpreter-exec" command.  */
 509 void
 510 _initialize_interpreter (void)
 511 {
 512   struct cmd_list_element *c;
 513
 514   c = add_cmd ("interpreter-exec", class_support,
 515                interpreter_exec_cmd, _("\
 516 Execute a command in an interpreter.  It takes two arguments:\n\
 517 The first argument is the name of the interpreter to use.\n\
 518 The second argument is the command to execute.\n"), &cmdlist);
 519   set_cmd_completer (c, interpreter_completer);
 520 }