gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002, 2003, 2007, 2008, 2009, 2010, 2011
   4    Free Software Foundation, 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
  45 struct interp
  46 {
  47   /* This is the name in "-i=" and set interpreter. */
  48   const char *name;
  49
  50   /* Interpreters are stored in a linked list, this is the next
  51      one...  */
  52   struct interp *next;
  53
  54   /* This is a cookie that an instance of the interpreter can use.
  55      This is a bit confused right now as the exact initialization
  56      sequence for it, and how it relates to the interpreter's uiout
  57      object is a bit confused.  */
  58   void *data;
  59
  60   /* Has the init_proc been run? */
  61   int inited;
  62
  63   /* This is the ui_out used to collect results for this interpreter.
  64      It can be a formatter for stdout, as is the case for the console
  65      & mi outputs, or it might be a result formatter.  */
  66   struct ui_out *interpreter_out;
  67
  68   const struct interp_procs *procs;
  69   int quiet_p;
  70 };
  71
  72 /* Functions local to this file. */
  73 static void initialize_interps (void);
  74 static char **interpreter_completer (struct cmd_list_element *cmd,
  75                                      char *text, char *word);
  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, void *data, struct ui_out *uiout,
  94             const struct interp_procs *procs)
  95 {
  96   struct interp *new_interp;
  97
  98   new_interp = XMALLOC (struct interp);
  99
 100   new_interp->name = xstrdup (name);
 101   new_interp->data = data;
 102   new_interp->interpreter_out = uiout;
 103   new_interp->quiet_p = 0;
 104   new_interp->procs = procs;
 105   new_interp->inited = 0;
 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       do_all_continuations ();
 153       ui_out_flush (uiout);
 154       if (current_interpreter->procs->suspend_proc
 155           && !current_interpreter->procs->suspend_proc (current_interpreter->
 156                                                         data))
 157         {
 158           error (_("Could not suspend interpreter \"%s\"."),
 159                  current_interpreter->name);
 160         }
 161     }
 162   else
 163     {
 164       first_time = 1;
 165     }
 166
 167   current_interpreter = interp;
 168   if (top_level)
 169     top_level_interpreter_ptr = interp;
 170
 171   /* We use interpreter_p for the "set interpreter" variable, so we need
 172      to make sure we have a malloc'ed copy for the set command to free. */
 173   if (interpreter_p != NULL
 174       && strcmp (current_interpreter->name, interpreter_p) != 0)
 175     {
 176       xfree (interpreter_p);
 177
 178       interpreter_p = xstrdup (current_interpreter->name);
 179     }
 180
 181   uiout = interp->interpreter_out;
 182
 183   /* Run the init proc.  If it fails, try to restore the old interp. */
 184
 185   if (!interp->inited)
 186     {
 187       if (interp->procs->init_proc != NULL)
 188         {
 189           interp->data = interp->procs->init_proc (top_level);
 190         }
 191       interp->inited = 1;
 192     }
 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           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 216                    interp->name);
 217           ui_out_text (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->interpreter_out;
 252
 253   return current_interpreter->interpreter_out;
 254 }
 255
 256 /* Returns true if the current interp is the passed in name. */
 257 int
 258 current_interp_named_p (const char *interp_name)
 259 {
 260   if (current_interpreter)
 261     return (strcmp (current_interpreter->name, interp_name) == 0);
 262
 263   return 0;
 264 }
 265
 266 /* This is called in display_gdb_prompt.  If the proc returns a zero
 267    value, display_gdb_prompt will return without displaying the
 268    prompt.  */
 269 int
 270 current_interp_display_prompt_p (void)
 271 {
 272   if (current_interpreter == NULL
 273       || current_interpreter->procs->prompt_proc_p == NULL)
 274     return 0;
 275   else
 276     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 277                                                       data);
 278 }
 279
 280 /* Run the current command interpreter's main loop.  */
 281 void
 282 current_interp_command_loop (void)
 283 {
 284   /* Somewhat messy.  For the moment prop up all the old ways of
 285      selecting the command loop.  `deprecated_command_loop_hook'
 286      should be deprecated.  */
 287   if (deprecated_command_loop_hook != NULL)
 288     deprecated_command_loop_hook ();
 289   else if (current_interpreter != NULL
 290            && current_interpreter->procs->command_loop_proc != NULL)
 291     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 292   else
 293     cli_command_loop ();
 294 }
 295
 296 int
 297 interp_quiet_p (struct interp *interp)
 298 {
 299   if (interp != NULL)
 300     return interp->quiet_p;
 301   else
 302     return current_interpreter->quiet_p;
 303 }
 304
 305 static int
 306 interp_set_quiet (struct interp *interp, int quiet)
 307 {
 308   int old_val = interp->quiet_p;
 309
 310   interp->quiet_p = quiet;
 311   return old_val;
 312 }
 313
 314 /* interp_exec - This executes COMMAND_STR in the current
 315    interpreter. */
 316 int
 317 interp_exec_p (struct interp *interp)
 318 {
 319   return interp->procs->exec_proc != NULL;
 320 }
 321
 322 struct gdb_exception
 323 interp_exec (struct interp *interp, const char *command_str)
 324 {
 325   if (interp->procs->exec_proc != NULL)
 326     {
 327       return interp->procs->exec_proc (interp->data, command_str);
 328     }
 329   return exception_none;
 330 }
 331
 332 /* A convenience routine that nulls out all the common command hooks.
 333    Use it when removing your interpreter in its suspend proc.  */
 334 void
 335 clear_interpreter_hooks (void)
 336 {
 337   deprecated_init_ui_hook = 0;
 338   deprecated_print_frame_info_listing_hook = 0;
 339   /*print_frame_more_info_hook = 0; */
 340   deprecated_query_hook = 0;
 341   deprecated_warning_hook = 0;
 342   deprecated_interactive_hook = 0;
 343   deprecated_readline_begin_hook = 0;
 344   deprecated_readline_hook = 0;
 345   deprecated_readline_end_hook = 0;
 346   deprecated_register_changed_hook = 0;
 347   deprecated_context_hook = 0;
 348   deprecated_target_wait_hook = 0;
 349   deprecated_call_command_hook = 0;
 350   deprecated_error_begin_hook = 0;
 351   deprecated_command_loop_hook = 0;
 352 }
 353
 354 /* This is a lazy init routine, called the first time the interpreter
 355    module is used.  I put it here just in case, but I haven't thought
 356    of a use for it yet.  I will probably bag it soon, since I don't
 357    think it will be necessary.  */
 358 static void
 359 initialize_interps (void)
 360 {
 361   interpreter_initialized = 1;
 362   /* Don't know if anything needs to be done here... */
 363 }
 364
 365 static void
 366 interpreter_exec_cmd (char *args, int from_tty)
 367 {
 368   struct interp *old_interp, *interp_to_use;
 369   char **prules = NULL;
 370   char **trule = NULL;
 371   unsigned int nrules;
 372   unsigned int i;
 373   int old_quiet, use_quiet;
 374
 375   if (args == NULL)
 376     error_no_arg (_("interpreter-exec command"));
 377
 378   prules = gdb_buildargv (args);
 379   make_cleanup_freeargv (prules);
 380
 381   nrules = 0;
 382   for (trule = prules; *trule != NULL; trule++)
 383     nrules++;
 384
 385   if (nrules < 2)
 386     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 387
 388   old_interp = current_interpreter;
 389
 390   interp_to_use = interp_lookup (prules[0]);
 391   if (interp_to_use == NULL)
 392     error (_("Could not find interpreter \"%s\"."), prules[0]);
 393
 394   /* Temporarily set interpreters quiet */
 395   old_quiet = interp_set_quiet (old_interp, 1);
 396   use_quiet = interp_set_quiet (interp_to_use, 1);
 397
 398   if (!interp_set (interp_to_use, 0))
 399     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 400
 401   for (i = 1; i < nrules; i++)
 402     {
 403       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 404
 405       if (e.reason < 0)
 406         {
 407           interp_set (old_interp, 0);
 408           interp_set_quiet (interp_to_use, use_quiet);
 409           interp_set_quiet (old_interp, old_quiet);
 410           error (_("error in command: \"%s\"."), prules[i]);
 411         }
 412     }
 413
 414   interp_set (old_interp, 0);
 415   interp_set_quiet (interp_to_use, use_quiet);
 416   interp_set_quiet (old_interp, old_quiet);
 417 }
 418
 419 /* List the possible interpreters which could complete the given text. */
 420 static char **
 421 interpreter_completer (struct cmd_list_element *ignore, char *text, char *word)
 422 {
 423   int alloced = 0;
 424   int textlen;
 425   int num_matches;
 426   char **matches;
 427   struct interp *interp;
 428
 429   /* We expect only a very limited number of interpreters, so just
 430      allocate room for all of them plus one for the last that must be NULL
 431      to correctly end the list. */
 432   for (interp = interp_list; interp != NULL; interp = interp->next)
 433     ++alloced;
 434   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 435
 436   num_matches = 0;
 437   textlen = strlen (text);
 438   for (interp = interp_list; interp != NULL; interp = interp->next)
 439     {
 440       if (strncmp (interp->name, text, textlen) == 0)
 441         {
 442           matches[num_matches] =
 443             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 444           if (word == text)
 445             strcpy (matches[num_matches], interp->name);
 446           else if (word > text)
 447             {
 448               /* Return some portion of interp->name */
 449               strcpy (matches[num_matches], interp->name + (word - text));
 450             }
 451           else
 452             {
 453               /* Return some of text plus interp->name */
 454               strncpy (matches[num_matches], word, text - word);
 455               matches[num_matches][text - word] = '\0';
 456               strcat (matches[num_matches], interp->name);
 457             }
 458           ++num_matches;
 459         }
 460     }
 461
 462   if (num_matches == 0)
 463     {
 464       xfree (matches);
 465       matches = NULL;
 466     }
 467
 468   return matches;
 469 }
 470
 471 struct interp *
 472 top_level_interpreter (void)
 473 {
 474   return top_level_interpreter_ptr;
 475 }
 476
 477 void *
 478 top_level_interpreter_data (void)
 479 {
 480   gdb_assert (top_level_interpreter_ptr);
 481   return top_level_interpreter_ptr->data;
 482 }
 483
 484 /* This just adds the "interpreter-exec" command.  */
 485 void
 486 _initialize_interpreter (void)
 487 {
 488   struct cmd_list_element *c;
 489
 490   c = add_cmd ("interpreter-exec", class_support,
 491                interpreter_exec_cmd, _("\
 492 Execute a command in an interpreter.  It takes two arguments:\n\
 493 The first argument is the name of the interpreter to use.\n\
 494 The second argument is the command to execute.\n"), &cmdlist);
 495   set_cmd_completer (c, interpreter_completer);
 496 }