gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000-2023 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 "gdbsupport/event-loop.h"
  36 #include "event-top.h"
  37 #include "interps.h"
  38 #include "completer.h"
  39 #include "ui.h"
  40 #include "main.h"
  41 #include "gdbsupport/buildargv.h"
  42 #include "gdbsupport/scope-exit.h"
  43
  44 /* The magic initialization routine for this module.  */
  45
  46 static struct interp *interp_lookup_existing (struct ui *ui,
  47                                               const char *name);
  48
  49 interp::interp (const char *name)
  50   : m_name (name)
  51 {
  52 }
  53
  54 interp::~interp () = default;
  55
  56 /* An interpreter factory.  Maps an interpreter name to the factory
  57    function that instantiates an interpreter by that name.  */
  58
  59 struct interp_factory
  60 {
  61   interp_factory (const char *name_, interp_factory_func func_)
  62   : name (name_), func (func_)
  63   {}
  64
  65   /* This is the name in "-i=INTERP" and "interpreter-exec INTERP".  */
  66   const char *name;
  67
  68   /* The function that creates the interpreter.  */
  69   interp_factory_func func;
  70 };
  71
  72 /* The registered interpreter factories.  */
  73 static std::vector<interp_factory> interpreter_factories;
  74
  75 /* See interps.h.  */
  76
  77 void
  78 interp_factory_register (const char *name, interp_factory_func func)
  79 {
  80   /* Assert that no factory for NAME is already registered.  */
  81   for (const interp_factory &f : interpreter_factories)
  82     if (strcmp (f.name, name) == 0)
  83       {
  84         internal_error (_("interpreter factory already registered: \"%s\"\n"),
  85                         name);
  86       }
  87
  88   interpreter_factories.emplace_back (name, func);
  89 }
  90
  91 /* Add interpreter INTERP to the gdb interpreter list.  The
  92    interpreter must not have previously been added.  */
  93 static void
  94 interp_add (struct ui *ui, struct interp *interp)
  95 {
  96   gdb_assert (interp_lookup_existing (ui, interp->name ()) == NULL);
  97
  98   ui->interp_list.push_back (*interp);
  99 }
 100
 101 /* This sets the current interpreter to be INTERP.  If INTERP has not
 102    been initialized, then this will also run the init method.
 103
 104    The TOP_LEVEL parameter tells if this new interpreter is
 105    the top-level one.  The top-level is what is requested
 106    on the command line, and is responsible for reporting general
 107    notification about target state changes.  For example, if
 108    MI is the top-level interpreter, then it will always report
 109    events such as target stops and new thread creation, even if they
 110    are caused by CLI commands.  */
 111
 112 static void
 113 interp_set (struct interp *interp, bool top_level)
 114 {
 115   struct interp *old_interp = current_ui->current_interpreter;
 116
 117   /* If we already have an interpreter, then trying to
 118      set top level interpreter is kinda pointless.  */
 119   gdb_assert (!top_level || !current_ui->current_interpreter);
 120   gdb_assert (!top_level || !current_ui->top_level_interpreter);
 121
 122   if (old_interp != NULL)
 123     {
 124       current_uiout->flush ();
 125       old_interp->suspend ();
 126     }
 127
 128   current_ui->current_interpreter = interp;
 129   if (top_level)
 130     current_ui->top_level_interpreter = interp;
 131
 132   if (interpreter_p != interp->name ())
 133     interpreter_p = interp->name ();
 134
 135   /* Run the init proc.  */
 136   if (!interp->inited)
 137     {
 138       interp->init (top_level);
 139       interp->inited = true;
 140     }
 141
 142   /* Do this only after the interpreter is initialized.  */
 143   current_uiout = interp->interp_ui_out ();
 144
 145   /* Clear out any installed interpreter hooks/event handlers.  */
 146   clear_interpreter_hooks ();
 147
 148   interp->resume ();
 149 }
 150
 151 /* Look up the interpreter for NAME.  If no such interpreter exists,
 152    return NULL, otherwise return a pointer to the interpreter.  */
 153
 154 static struct interp *
 155 interp_lookup_existing (struct ui *ui, const char *name)
 156 {
 157   for (interp &interp : ui->interp_list)
 158     if (strcmp (interp.name (), name) == 0)
 159       return &interp;
 160
 161   return nullptr;
 162 }
 163
 164 /* See interps.h.  */
 165
 166 struct interp *
 167 interp_lookup (struct ui *ui, const char *name)
 168 {
 169   if (name == NULL || strlen (name) == 0)
 170     return NULL;
 171
 172   /* Only create each interpreter once per top level.  */
 173   struct interp *interp = interp_lookup_existing (ui, name);
 174   if (interp != NULL)
 175     return interp;
 176
 177   for (const interp_factory &factory : interpreter_factories)
 178     if (strcmp (factory.name, name) == 0)
 179       {
 180         interp = factory.func (factory.name);
 181         interp_add (ui, interp);
 182         return interp;
 183       }
 184
 185   return NULL;
 186 }
 187
 188 /* See interps.h.  */
 189
 190 void
 191 set_top_level_interpreter (const char *name)
 192 {
 193   /* Find it.  */
 194   struct interp *interp = interp_lookup (current_ui, name);
 195
 196   if (interp == NULL)
 197     error (_("Interpreter `%s' unrecognized"), name);
 198   /* Install it.  */
 199   interp_set (interp, true);
 200 }
 201
 202 void
 203 current_interp_set_logging (ui_file_up logfile, bool logging_redirect,
 204                             bool debug_redirect)
 205 {
 206   struct interp *interp = current_ui->current_interpreter;
 207
 208   interp->set_logging (std::move (logfile), logging_redirect, debug_redirect);
 209 }
 210
 211 /* Temporarily overrides the current interpreter.  */
 212 struct interp *
 213 scoped_restore_interp::set_interp (const char *name)
 214 {
 215   struct interp *interp = interp_lookup (current_ui, name);
 216   struct interp *old_interp = current_ui->current_interpreter;
 217
 218   if (interp)
 219     current_ui->current_interpreter = interp;
 220
 221   return old_interp;
 222 }
 223
 224 /* Returns true if the current interp is the passed in name.  */
 225 int
 226 current_interp_named_p (const char *interp_name)
 227 {
 228   interp *interp = current_ui->current_interpreter;
 229
 230   if (interp != NULL)
 231     return (strcmp (interp->name (), interp_name) == 0);
 232
 233   return 0;
 234 }
 235
 236 /* The interpreter that was active when a command was executed.
 237    Normally that'd always be CURRENT_INTERPRETER, except that MI's
 238    -interpreter-exec command doesn't actually flip the current
 239    interpreter when running its sub-command.  The
 240    `command_interpreter' global tracks when interp_exec is called
 241    (IOW, when -interpreter-exec is called).  If that is set, it is
 242    INTERP in '-interpreter-exec INTERP "CMD"' or in 'interpreter-exec
 243    INTERP "CMD".  Otherwise, interp_exec isn't active, and so the
 244    interpreter running the command is the current interpreter.  */
 245
 246 struct interp *
 247 command_interp (void)
 248 {
 249   if (current_ui->command_interpreter != nullptr)
 250     return current_ui->command_interpreter;
 251   else
 252     return current_ui->current_interpreter;
 253 }
 254
 255 /* interp_exec - This executes COMMAND_STR in the current
 256    interpreter.  */
 257
 258 void
 259 interp_exec (struct interp *interp, const char *command_str)
 260 {
 261   /* See `command_interp' for why we do this.  */
 262   scoped_restore save_command_interp
 263     = make_scoped_restore (&current_ui->command_interpreter, interp);
 264
 265   interp->exec (command_str);
 266 }
 267
 268 /* A convenience routine that nulls out all the common command hooks.
 269    Use it when removing your interpreter in its suspend proc.  */
 270 void
 271 clear_interpreter_hooks (void)
 272 {
 273   deprecated_print_frame_info_listing_hook = 0;
 274   /*print_frame_more_info_hook = 0; */
 275   deprecated_query_hook = 0;
 276   deprecated_warning_hook = 0;
 277   deprecated_readline_begin_hook = 0;
 278   deprecated_readline_hook = 0;
 279   deprecated_readline_end_hook = 0;
 280   deprecated_context_hook = 0;
 281   deprecated_call_command_hook = 0;
 282   deprecated_error_begin_hook = 0;
 283 }
 284
 285 static void
 286 interpreter_exec_cmd (const char *args, int from_tty)
 287 {
 288   struct interp *interp_to_use;
 289   unsigned int nrules;
 290   unsigned int i;
 291
 292   /* Interpreters may clobber stdout/stderr (e.g.  in mi_interp::resume at time
 293      of writing), preserve their state here.  */
 294   scoped_restore save_stdout = make_scoped_restore (&gdb_stdout);
 295   scoped_restore save_stderr = make_scoped_restore (&gdb_stderr);
 296   scoped_restore save_stdlog = make_scoped_restore (&gdb_stdlog);
 297   scoped_restore save_stdtarg = make_scoped_restore (&gdb_stdtarg);
 298   scoped_restore save_stdtargerr = make_scoped_restore (&gdb_stdtargerr);
 299
 300   if (args == NULL)
 301     error_no_arg (_("interpreter-exec command"));
 302
 303   gdb_argv prules (args);
 304   nrules = prules.count ();
 305
 306   if (nrules < 2)
 307     error (_("Usage: interpreter-exec INTERPRETER COMMAND..."));
 308
 309   interp *old_interp = current_ui->current_interpreter;
 310
 311   interp_to_use = interp_lookup (current_ui, prules[0]);
 312   if (interp_to_use == NULL)
 313     error (_("Could not find interpreter \"%s\"."), prules[0]);
 314
 315   interp_set (interp_to_use, false);
 316   SCOPE_EXIT
 317     {
 318       interp_set (old_interp, false);
 319     };
 320
 321   for (i = 1; i < nrules; i++)
 322     interp_exec (interp_to_use, prules[i]);
 323 }
 324
 325 /* See interps.h.  */
 326
 327 void
 328 interpreter_completer (struct cmd_list_element *ignore,
 329                        completion_tracker &tracker,
 330                        const char *text, const char *word)
 331 {
 332   int textlen = strlen (text);
 333
 334   for (const interp_factory &interp : interpreter_factories)
 335     {
 336       if (strncmp (interp.name, text, textlen) == 0)
 337         {
 338           tracker.add_completion
 339             (make_completion_match_str (interp.name, text, word));
 340         }
 341     }
 342 }
 343
 344 struct interp *
 345 top_level_interpreter (void)
 346 {
 347   return current_ui->top_level_interpreter;
 348 }
 349
 350 /* See interps.h.  */
 351
 352 struct interp *
 353 current_interpreter (void)
 354 {
 355   return current_ui->current_interpreter;
 356 }
 357
 358 /* Helper interps_notify_* functions.  Call METHOD on the top-level interpreter
 359    of all UIs.  */
 360
 361 template <typename MethodType, typename ...Args>
 362 void
 363 interps_notify (MethodType method, Args&&... args)
 364 {
 365   SWITCH_THRU_ALL_UIS ()
 366     {
 367       interp *tli = top_level_interpreter ();
 368       if (tli != nullptr)
 369         (tli->*method) (std::forward<Args> (args)...);
 370     }
 371 }
 372
 373 /* See interps.h.  */
 374
 375 void
 376 interps_notify_signal_received (gdb_signal sig)
 377 {
 378   interps_notify (&interp::on_signal_received, sig);
 379 }
 380
 381 /* See interps.h.  */
 382
 383 void
 384 interps_notify_signal_exited (gdb_signal sig)
 385 {
 386   interps_notify (&interp::on_signal_exited, sig);
 387 }
 388
 389 /* See interps.h.  */
 390
 391 void
 392 interps_notify_no_history ()
 393 {
 394   interps_notify (&interp::on_no_history);
 395 }
 396
 397 /* See interps.h.  */
 398
 399 void
 400 interps_notify_normal_stop (bpstat *bs, int print_frame)
 401 {
 402   interps_notify (&interp::on_normal_stop, bs, print_frame);
 403 }
 404
 405 /* See interps.h.  */
 406
 407 void
 408 interps_notify_exited (int status)
 409 {
 410   interps_notify (&interp::on_exited, status);
 411 }
 412
 413 /* See interps.h.  */
 414
 415 void
 416 interps_notify_user_selected_context_changed (user_selected_what selection)
 417 {
 418   interps_notify (&interp::on_user_selected_context_changed, selection);
 419 }
 420
 421 /* See interps.h.  */
 422
 423 void
 424 interps_notify_new_thread (thread_info *t)
 425 {
 426   interps_notify (&interp::on_new_thread, t);
 427 }
 428
 429 /* See interps.h.  */
 430
 431 void
 432 interps_notify_thread_exited (thread_info *t,
 433                               std::optional<ULONGEST> exit_code,
 434                               int silent)
 435 {
 436   interps_notify (&interp::on_thread_exited, t, exit_code, silent);
 437 }
 438
 439 /* See interps.h.  */
 440
 441 void
 442 interps_notify_inferior_added (inferior *inf)
 443 {
 444   interps_notify (&interp::on_inferior_added, inf);
 445 }
 446
 447 /* See interps.h.  */
 448
 449 void
 450 interps_notify_inferior_appeared (inferior *inf)
 451 {
 452   interps_notify (&interp::on_inferior_appeared, inf);
 453 }
 454
 455 /* See interps.h.  */
 456
 457 void
 458 interps_notify_inferior_disappeared (inferior *inf)
 459 {
 460   interps_notify (&interp::on_inferior_disappeared, inf);
 461 }
 462
 463 /* See interps.h.  */
 464
 465 void
 466 interps_notify_inferior_removed (inferior *inf)
 467 {
 468   interps_notify (&interp::on_inferior_removed, inf);
 469 }
 470
 471 /* See interps.h.  */
 472
 473 void
 474 interps_notify_record_changed (inferior *inf, int started, const char *method,
 475                                const char *format)
 476 {
 477   interps_notify (&interp::on_record_changed, inf, started, method, format);
 478 }
 479
 480 /* See interps.h.  */
 481
 482 void
 483 interps_notify_target_resumed (ptid_t ptid)
 484 {
 485   interps_notify (&interp::on_target_resumed, ptid);
 486 }
 487
 488 /* See interps.h.  */
 489
 490 void
 491 interps_notify_solib_loaded (const shobj &so)
 492 {
 493   interps_notify (&interp::on_solib_loaded, so);
 494 }
 495
 496 /* See interps.h.  */
 497
 498 void
 499 interps_notify_solib_unloaded (const shobj &so)
 500 {
 501   interps_notify (&interp::on_solib_unloaded, so);
 502 }
 503
 504 /* See interps.h.  */
 505
 506 void
 507 interps_notify_traceframe_changed (int tfnum, int tpnum)
 508 {
 509   interps_notify (&interp::on_traceframe_changed, tfnum, tpnum);
 510 }
 511
 512 /* See interps.h.  */
 513
 514 void
 515 interps_notify_tsv_created (const trace_state_variable *tsv)
 516 {
 517   interps_notify (&interp::on_tsv_created, tsv);
 518 }
 519
 520 /* See interps.h.  */
 521
 522 void
 523 interps_notify_tsv_deleted (const trace_state_variable *tsv)
 524 {
 525   interps_notify (&interp::on_tsv_deleted, tsv);
 526 }
 527
 528 /* See interps.h.  */
 529
 530 void
 531 interps_notify_tsv_modified (const trace_state_variable *tsv)
 532 {
 533   interps_notify (&interp::on_tsv_modified, tsv);
 534 }
 535
 536 /* See interps.h.  */
 537
 538 void
 539 interps_notify_breakpoint_created (breakpoint *b)
 540 {
 541   interps_notify (&interp::on_breakpoint_created, b);
 542 }
 543
 544 /* See interps.h.  */
 545
 546 void
 547 interps_notify_breakpoint_deleted (breakpoint *b)
 548 {
 549   interps_notify (&interp::on_breakpoint_deleted, b);
 550 }
 551
 552 /* See interps.h.  */
 553
 554 void
 555 interps_notify_breakpoint_modified (breakpoint *b)
 556 {
 557   interps_notify (&interp::on_breakpoint_modified, b);
 558 }
 559
 560 /* See interps.h.  */
 561
 562 void
 563 interps_notify_param_changed (const char *param, const char *value)
 564 {
 565   interps_notify (&interp::on_param_changed, param, value);
 566 }
 567
 568 /* See interps.h.  */
 569
 570 void
 571 interps_notify_memory_changed (inferior *inf, CORE_ADDR addr, ssize_t len,
 572                                const bfd_byte *data)
 573 {
 574   interps_notify (&interp::on_memory_changed, inf, addr, len, data);
 575 }
 576
 577 /* This just adds the "interpreter-exec" command.  */
 578 void _initialize_interpreter ();
 579 void
 580 _initialize_interpreter ()
 581 {
 582   struct cmd_list_element *c;
 583
 584   c = add_cmd ("interpreter-exec", class_support,
 585                interpreter_exec_cmd, _("\
 586 Execute a command in an interpreter.\n\
 587 Usage: interpreter-exec INTERPRETER COMMAND...\n\
 588 The first argument is the name of the interpreter to use.\n\
 589 The following arguments are the commands to execute.\n\
 590 A command can have arguments, separated by spaces.\n\
 591 These spaces must be escaped using \\ or the command\n\
 592 and its arguments must be enclosed in double quotes."), &cmdlist);
 593   set_cmd_completer (c, interpreter_completer);
 594 }