gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2014 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 = XNEW (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   if (!first_time && !interp_quiet_p (interp))
 208     {
 209       xsnprintf (buffer, sizeof (buffer),
 210                  "Switching to interpreter \"%.24s\".\n", interp->name);
 211       ui_out_text (current_uiout, buffer);
 212     }
 213
 214   return 1;
 215 }
 216
 217 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 218    interpreter exists, return NULL, otherwise return a pointer to the
 219    interpreter.  */
 220 struct interp *
 221 interp_lookup (const char *name)
 222 {
 223   struct interp *interp;
 224
 225   if (name == NULL || strlen (name) == 0)
 226     return NULL;
 227
 228   for (interp = interp_list; interp != NULL; interp = interp->next)
 229     {
 230       if (strcmp (interp->name, name) == 0)
 231         return interp;
 232     }
 233
 234   return NULL;
 235 }
 236
 237 /* Returns the current interpreter.  */
 238
 239 struct ui_out *
 240 interp_ui_out (struct interp *interp)
 241 {
 242   if (interp != NULL)
 243     return interp->procs->ui_out_proc (interp);
 244
 245   return current_interpreter->procs->ui_out_proc (current_interpreter);
 246 }
 247
 248 int
 249 current_interp_set_logging (int start_log, struct ui_file *out,
 250                             struct ui_file *logfile)
 251 {
 252   if (current_interpreter == NULL
 253       || current_interpreter->procs->set_logging_proc == NULL)
 254     return 0;
 255
 256   return current_interpreter->procs->set_logging_proc (current_interpreter,
 257                                                        start_log, out,
 258                                                        logfile);
 259 }
 260
 261 /* Temporarily overrides the current interpreter.  */
 262 struct interp *
 263 interp_set_temp (const char *name)
 264 {
 265   struct interp *interp = interp_lookup (name);
 266   struct interp *old_interp = current_interpreter;
 267
 268   if (interp)
 269     current_interpreter = interp;
 270   return old_interp;
 271 }
 272
 273 /* Returns the interpreter's cookie.  */
 274
 275 void *
 276 interp_data (struct interp *interp)
 277 {
 278   return interp->data;
 279 }
 280
 281 /* Returns the interpreter's name.  */
 282
 283 const char *
 284 interp_name (struct interp *interp)
 285 {
 286   return interp->name;
 287 }
 288
 289 /* Returns true if the current interp is the passed in name.  */
 290 int
 291 current_interp_named_p (const char *interp_name)
 292 {
 293   if (current_interpreter)
 294     return (strcmp (current_interpreter->name, interp_name) == 0);
 295
 296   return 0;
 297 }
 298
 299 /* The interpreter that is active while `interp_exec' is active, NULL
 300    at all other times.  */
 301 static struct interp *command_interpreter;
 302
 303 /* The interpreter that was active when a command was executed.
 304    Normally that'd always be CURRENT_INTERPRETER, except that MI's
 305    -interpreter-exec command doesn't actually flip the current
 306    interpreter when running its sub-command.  The
 307    `command_interpreter' global tracks when interp_exec is called
 308    (IOW, when -interpreter-exec is called).  If that is set, it is
 309    INTERP in '-interpreter-exec INTERP "CMD"' or in 'interpreter-exec
 310    INTERP "CMD".  Otherwise, interp_exec isn't active, and so the
 311    interpreter running the command is the current interpreter.  */
 312
 313 struct interp *
 314 command_interp (void)
 315 {
 316   if (command_interpreter != NULL)
 317     return command_interpreter;
 318   else
 319     return current_interpreter;
 320 }
 321
 322 /* Run the current command interpreter's main loop.  */
 323 void
 324 current_interp_command_loop (void)
 325 {
 326   gdb_assert (current_interpreter != NULL);
 327
 328   current_interpreter->procs->command_loop_proc (current_interpreter->data);
 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
 352 struct gdb_exception
 353 interp_exec (struct interp *interp, const char *command_str)
 354 {
 355   struct gdb_exception ex;
 356   struct interp *save_command_interp;
 357
 358   gdb_assert (interp->procs->exec_proc != NULL);
 359
 360   /* See `command_interp' for why we do this.  */
 361   save_command_interp = command_interpreter;
 362   command_interpreter = interp;
 363
 364   ex = interp->procs->exec_proc (interp->data, command_str);
 365
 366   command_interpreter = save_command_interp;
 367
 368   return ex;
 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 }
 391
 392 /* This is a lazy init routine, called the first time the interpreter
 393    module is used.  I put it here just in case, but I haven't thought
 394    of a use for it yet.  I will probably bag it soon, since I don't
 395    think it will be necessary.  */
 396 static void
 397 initialize_interps (void)
 398 {
 399   interpreter_initialized = 1;
 400   /* Don't know if anything needs to be done here...  */
 401 }
 402
 403 static void
 404 interpreter_exec_cmd (char *args, int from_tty)
 405 {
 406   struct interp *old_interp, *interp_to_use;
 407   char **prules = NULL;
 408   char **trule = NULL;
 409   unsigned int nrules;
 410   unsigned int i;
 411   int old_quiet, use_quiet;
 412   struct cleanup *cleanup;
 413
 414   if (args == NULL)
 415     error_no_arg (_("interpreter-exec command"));
 416
 417   prules = gdb_buildargv (args);
 418   cleanup = 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   do_cleanups (cleanup);
 458 }
 459
 460 /* List the possible interpreters which could complete the given text.  */
 461 static VEC (char_ptr) *
 462 interpreter_completer (struct cmd_list_element *ignore,
 463                        const char *text, const char *word)
 464 {
 465   int textlen;
 466   VEC (char_ptr) *matches = NULL;
 467   struct interp *interp;
 468
 469   textlen = strlen (text);
 470   for (interp = interp_list; interp != NULL; interp = interp->next)
 471     {
 472       if (strncmp (interp->name, text, textlen) == 0)
 473         {
 474           char *match;
 475
 476           match = (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 477           if (word == text)
 478             strcpy (match, interp->name);
 479           else if (word > text)
 480             {
 481               /* Return some portion of interp->name.  */
 482               strcpy (match, interp->name + (word - text));
 483             }
 484           else
 485             {
 486               /* Return some of text plus interp->name.  */
 487               strncpy (match, word, text - word);
 488               match[text - word] = '\0';
 489               strcat (match, interp->name);
 490             }
 491           VEC_safe_push (char_ptr, matches, match);
 492         }
 493     }
 494
 495   return matches;
 496 }
 497
 498 struct interp *
 499 top_level_interpreter (void)
 500 {
 501   return top_level_interpreter_ptr;
 502 }
 503
 504 void *
 505 top_level_interpreter_data (void)
 506 {
 507   gdb_assert (top_level_interpreter_ptr);
 508   return top_level_interpreter_ptr->data;
 509 }
 510
 511 /* This just adds the "interpreter-exec" command.  */
 512 void
 513 _initialize_interpreter (void)
 514 {
 515   struct cmd_list_element *c;
 516
 517   c = add_cmd ("interpreter-exec", class_support,
 518                interpreter_exec_cmd, _("\
 519 Execute a command in an interpreter.  It takes two arguments:\n\
 520 The first argument is the name of the interpreter to use.\n\
 521 The second argument is the command to execute.\n"), &cmdlist);
 522   set_cmd_completer (c, interpreter_completer);
 523 }