gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002, 2003, 2007, 2008 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 "gdb_string.h"
  40 #include "gdb-events.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 (char *text, char *word);
  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, void *data, struct ui_out *uiout,
  93             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 = data;
 101   new_interp->interpreter_out = uiout;
 102   new_interp->quiet_p = 0;
 103   new_interp->procs = procs;
 104   new_interp->inited = 0;
 105
 106   return new_interp;
 107 }
 108
 109 /* Add interpreter INTERP to the gdb interpreter list.  The
 110    interpreter must not have previously been added.  */
 111 void
 112 interp_add (struct interp *interp)
 113 {
 114   if (!interpreter_initialized)
 115     initialize_interps ();
 116
 117   gdb_assert (interp_lookup (interp->name) == NULL);
 118
 119   interp->next = interp_list;
 120   interp_list = interp;
 121 }
 122
 123 /* This sets the current interpreter to be INTERP.  If INTERP has not
 124    been initialized, then this will also run the init proc.  If the
 125    init proc is successful, return 1, if it fails, set the old
 126    interpreter back in place and return 0.  If we can't restore the
 127    old interpreter, then raise an internal error, since we are in
 128    pretty bad shape at this point.
 129
 130    The TOP_LEVEL parameter tells if this new interpreter is
 131    the top-level one.  The top-level is what is requested
 132    on the command line, and is responsible for reporting general
 133    notification about target state changes.  For example, if
 134    MI is the top-level interpreter, then it will always report
 135    events such as target stops and new thread creation, even if they
 136    are caused by CLI commands.  */
 137 int
 138 interp_set (struct interp *interp, int top_level)
 139 {
 140   struct interp *old_interp = current_interpreter;
 141   int first_time = 0;
 142   char buffer[64];
 143
 144   /* If we already have an interpreter, then trying to
 145      set top level interpreter is kinda pointless.  */
 146   gdb_assert (!top_level || !current_interpreter);
 147   gdb_assert (!top_level || !top_level_interpreter_ptr);
 148
 149   if (current_interpreter != NULL)
 150     {
 151       do_all_continuations (0);
 152       ui_out_flush (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   uiout = interp->interpreter_out;
 181
 182   /* Run the init proc.  If it fails, try to restore the old interp. */
 183
 184   if (!interp->inited)
 185     {
 186       if (interp->procs->init_proc != NULL)
 187         {
 188           interp->data = interp->procs->init_proc (top_level);
 189         }
 190       interp->inited = 1;
 191     }
 192
 193   /* Clear out any installed interpreter hooks/event handlers.  */
 194   clear_interpreter_hooks ();
 195
 196   if (interp->procs->resume_proc != NULL
 197       && (!interp->procs->resume_proc (interp->data)))
 198     {
 199       if (old_interp == NULL || !interp_set (old_interp, 0))
 200         internal_error (__FILE__, __LINE__,
 201                         _("Failed to initialize new interp \"%s\" %s"),
 202                         interp->name, "and could not restore old interp!\n");
 203       return 0;
 204     }
 205
 206   /* Finally, put up the new prompt to show that we are indeed here.
 207      Also, display_gdb_prompt for the console does some readline magic
 208      which is needed for the console interpreter, at least... */
 209
 210   if (!first_time)
 211     {
 212       if (!interp_quiet_p (interp))
 213         {
 214           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 215                    interp->name);
 216           ui_out_text (uiout, buffer);
 217         }
 218       display_gdb_prompt (NULL);
 219     }
 220
 221   return 1;
 222 }
 223
 224 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 225    interpreter exists, return NULL, otherwise return a pointer to the
 226    interpreter.  */
 227 struct interp *
 228 interp_lookup (const char *name)
 229 {
 230   struct interp *interp;
 231
 232   if (name == NULL || strlen (name) == 0)
 233     return NULL;
 234
 235   for (interp = interp_list; interp != NULL; interp = interp->next)
 236     {
 237       if (strcmp (interp->name, name) == 0)
 238         return interp;
 239     }
 240
 241   return NULL;
 242 }
 243
 244 /* Returns the current interpreter. */
 245
 246 struct ui_out *
 247 interp_ui_out (struct interp *interp)
 248 {
 249   if (interp != NULL)
 250     return interp->interpreter_out;
 251
 252   return current_interpreter->interpreter_out;
 253 }
 254
 255 /* Returns true if the current interp is the passed in name. */
 256 int
 257 current_interp_named_p (const char *interp_name)
 258 {
 259   if (current_interpreter)
 260     return (strcmp (current_interpreter->name, interp_name) == 0);
 261
 262   return 0;
 263 }
 264
 265 /* This is called in display_gdb_prompt.  If the proc returns a zero
 266    value, display_gdb_prompt will return without displaying the
 267    prompt.  */
 268 int
 269 current_interp_display_prompt_p (void)
 270 {
 271   if (current_interpreter == NULL
 272       || current_interpreter->procs->prompt_proc_p == NULL)
 273     return 0;
 274   else
 275     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 276                                                       data);
 277 }
 278
 279 /* Run the current command interpreter's main loop.  */
 280 void
 281 current_interp_command_loop (void)
 282 {
 283   /* Somewhat messy.  For the moment prop up all the old ways of
 284      selecting the command loop.  `deprecated_command_loop_hook'
 285      should be deprecated.  */
 286   if (deprecated_command_loop_hook != NULL)
 287     deprecated_command_loop_hook ();
 288   else if (current_interpreter != NULL
 289            && current_interpreter->procs->command_loop_proc != NULL)
 290     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 291   else
 292     cli_command_loop ();
 293 }
 294
 295 int
 296 interp_quiet_p (struct interp *interp)
 297 {
 298   if (interp != NULL)
 299     return interp->quiet_p;
 300   else
 301     return current_interpreter->quiet_p;
 302 }
 303
 304 static int
 305 interp_set_quiet (struct interp *interp, int quiet)
 306 {
 307   int old_val = interp->quiet_p;
 308   interp->quiet_p = quiet;
 309   return old_val;
 310 }
 311
 312 /* interp_exec - This executes COMMAND_STR in the current
 313    interpreter. */
 314 int
 315 interp_exec_p (struct interp *interp)
 316 {
 317   return interp->procs->exec_proc != NULL;
 318 }
 319
 320 struct gdb_exception
 321 interp_exec (struct interp *interp, const char *command_str)
 322 {
 323   if (interp->procs->exec_proc != NULL)
 324     {
 325       return interp->procs->exec_proc (interp->data, command_str);
 326     }
 327   return exception_none;
 328 }
 329
 330 /* A convenience routine that nulls out all the common command hooks.
 331    Use it when removing your interpreter in its suspend proc.  */
 332 void
 333 clear_interpreter_hooks (void)
 334 {
 335   deprecated_init_ui_hook = 0;
 336   deprecated_print_frame_info_listing_hook = 0;
 337   /*print_frame_more_info_hook = 0; */
 338   deprecated_query_hook = 0;
 339   deprecated_warning_hook = 0;
 340   deprecated_create_breakpoint_hook = 0;
 341   deprecated_delete_breakpoint_hook = 0;
 342   deprecated_modify_breakpoint_hook = 0;
 343   deprecated_interactive_hook = 0;
 344   deprecated_readline_begin_hook = 0;
 345   deprecated_readline_hook = 0;
 346   deprecated_readline_end_hook = 0;
 347   deprecated_register_changed_hook = 0;
 348   deprecated_memory_changed_hook = 0;
 349   deprecated_context_hook = 0;
 350   deprecated_target_wait_hook = 0;
 351   deprecated_call_command_hook = 0;
 352   deprecated_error_hook = 0;
 353   deprecated_error_begin_hook = 0;
 354   deprecated_command_loop_hook = 0;
 355   clear_gdb_event_hooks ();
 356 }
 357
 358 /* This is a lazy init routine, called the first time the interpreter
 359    module is used.  I put it here just in case, but I haven't thought
 360    of a use for it yet.  I will probably bag it soon, since I don't
 361    think it will be necessary.  */
 362 static void
 363 initialize_interps (void)
 364 {
 365   interpreter_initialized = 1;
 366   /* Don't know if anything needs to be done here... */
 367 }
 368
 369 static void
 370 interpreter_exec_cmd (char *args, int from_tty)
 371 {
 372   struct interp *old_interp, *interp_to_use;
 373   char **prules = NULL;
 374   char **trule = NULL;
 375   unsigned int nrules;
 376   unsigned int i;
 377   int old_quiet, use_quiet;
 378
 379   prules = buildargv (args);
 380   if (prules == NULL)
 381     {
 382       error (_("unable to parse arguments"));
 383     }
 384
 385   nrules = 0;
 386   if (prules != NULL)
 387     {
 388       for (trule = prules; *trule != NULL; trule++)
 389         {
 390           nrules++;
 391         }
 392     }
 393
 394   if (nrules < 2)
 395     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 396
 397   old_interp = current_interpreter;
 398
 399   interp_to_use = interp_lookup (prules[0]);
 400   if (interp_to_use == NULL)
 401     error (_("Could not find interpreter \"%s\"."), prules[0]);
 402
 403   /* Temporarily set interpreters quiet */
 404   old_quiet = interp_set_quiet (old_interp, 1);
 405   use_quiet = interp_set_quiet (interp_to_use, 1);
 406
 407   if (!interp_set (interp_to_use, 0))
 408     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 409
 410   for (i = 1; i < nrules; i++)
 411     {
 412       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 413       if (e.reason < 0)
 414         {
 415           interp_set (old_interp, 0);
 416           interp_set_quiet (interp_to_use, use_quiet);
 417           interp_set_quiet (old_interp, old_quiet);
 418           error (_("error in command: \"%s\"."), prules[i]);
 419         }
 420     }
 421
 422   interp_set (old_interp, 0);
 423   interp_set_quiet (interp_to_use, use_quiet);
 424   interp_set_quiet (old_interp, old_quiet);
 425 }
 426
 427 /* List the possible interpreters which could complete the given text. */
 428 static char **
 429 interpreter_completer (char *text, char *word)
 430 {
 431   int alloced = 0;
 432   int textlen;
 433   int num_matches;
 434   char **matches;
 435   struct interp *interp;
 436
 437   /* We expect only a very limited number of interpreters, so just
 438      allocate room for all of them plus one for the last that must be NULL
 439      to correctly end the list. */
 440   for (interp = interp_list; interp != NULL; interp = interp->next)
 441     ++alloced;
 442   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 443
 444   num_matches = 0;
 445   textlen = strlen (text);
 446   for (interp = interp_list; interp != NULL; interp = interp->next)
 447     {
 448       if (strncmp (interp->name, text, textlen) == 0)
 449         {
 450           matches[num_matches] =
 451             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 452           if (word == text)
 453             strcpy (matches[num_matches], interp->name);
 454           else if (word > text)
 455             {
 456               /* Return some portion of interp->name */
 457               strcpy (matches[num_matches], interp->name + (word - text));
 458             }
 459           else
 460             {
 461               /* Return some of text plus interp->name */
 462               strncpy (matches[num_matches], word, text - word);
 463               matches[num_matches][text - word] = '\0';
 464               strcat (matches[num_matches], interp->name);
 465             }
 466           ++num_matches;
 467         }
 468     }
 469
 470   if (num_matches == 0)
 471     {
 472       xfree (matches);
 473       matches = NULL;
 474     }
 475
 476   return matches;
 477 }
 478
 479 struct interp *
 480 top_level_interpreter (void)
 481 {
 482   return top_level_interpreter_ptr;
 483 }
 484
 485 void *
 486 top_level_interpreter_data (void)
 487 {
 488   gdb_assert (top_level_interpreter_ptr);
 489   return top_level_interpreter_ptr->data;
 490 }
 491
 492 /* This just adds the "interpreter-exec" command.  */
 493 void
 494 _initialize_interpreter (void)
 495 {
 496   struct cmd_list_element *c;
 497
 498   c = add_cmd ("interpreter-exec", class_support,
 499                interpreter_exec_cmd, _("\
 500 Execute a command in an interpreter.  It takes two arguments:\n\
 501 The first argument is the name of the interpreter to use.\n\
 502 The second argument is the command to execute.\n"), &cmdlist);
 503   set_cmd_completer (c, interpreter_completer);
 504 }