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 #include "continuations.h"
  45
  46 struct interp
  47 {
  48   /* This is the name in "-i=" and set interpreter.  */
  49   const char *name;
  50
  51   /* Interpreters are stored in a linked list, this is the next
  52      one...  */
  53   struct interp *next;
  54
  55   /* This is a cookie that an instance of the interpreter can use.
  56      This is a bit confused right now as the exact initialization
  57      sequence for it, and how it relates to the interpreter's uiout
  58      object is a bit confused.  */
  59   void *data;
  60
  61   /* Has the init_proc been run?  */
  62   int inited;
  63
  64   /* This is the ui_out used to collect results for this interpreter.
  65      It can be a formatter for stdout, as is the case for the console
  66      & mi outputs, or it might be a result formatter.  */
  67   struct ui_out *interpreter_out;
  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 static char **interpreter_completer (struct cmd_list_element *cmd,
  76                                      char *text, char *word);
  77
  78 /* The magic initialization routine for this module.  */
  79
  80 void _initialize_interpreter (void);
  81
  82 /* Variables local to this file: */
  83
  84 static struct interp *interp_list = NULL;
  85 static struct interp *current_interpreter = NULL;
  86 static struct interp *top_level_interpreter_ptr = NULL;
  87
  88 static int interpreter_initialized = 0;
  89
  90 /* interp_new - This allocates space for a new interpreter,
  91    fills the fields from the inputs, and returns a pointer to the
  92    interpreter.  */
  93 struct interp *
  94 interp_new (const char *name, void *data, struct ui_out *uiout,
  95             const struct interp_procs *procs)
  96 {
  97   struct interp *new_interp;
  98
  99   new_interp = XMALLOC (struct interp);
 100
 101   new_interp->name = xstrdup (name);
 102   new_interp->data = data;
 103   new_interp->interpreter_out = uiout;
 104   new_interp->quiet_p = 0;
 105   new_interp->procs = procs;
 106   new_interp->inited = 0;
 107
 108   return new_interp;
 109 }
 110
 111 /* Add interpreter INTERP to the gdb interpreter list.  The
 112    interpreter must not have previously been added.  */
 113 void
 114 interp_add (struct interp *interp)
 115 {
 116   if (!interpreter_initialized)
 117     initialize_interps ();
 118
 119   gdb_assert (interp_lookup (interp->name) == NULL);
 120
 121   interp->next = interp_list;
 122   interp_list = interp;
 123 }
 124
 125 /* This sets the current interpreter to be INTERP.  If INTERP has not
 126    been initialized, then this will also run the init proc.  If the
 127    init proc is successful, return 1, if it fails, set the old
 128    interpreter back in place and return 0.  If we can't restore the
 129    old interpreter, then raise an internal error, since we are in
 130    pretty bad shape at this point.
 131
 132    The TOP_LEVEL parameter tells if this new interpreter is
 133    the top-level one.  The top-level is what is requested
 134    on the command line, and is responsible for reporting general
 135    notification about target state changes.  For example, if
 136    MI is the top-level interpreter, then it will always report
 137    events such as target stops and new thread creation, even if they
 138    are caused by CLI commands.  */
 139 int
 140 interp_set (struct interp *interp, int top_level)
 141 {
 142   struct interp *old_interp = current_interpreter;
 143   int first_time = 0;
 144   char buffer[64];
 145
 146   /* If we already have an interpreter, then trying to
 147      set top level interpreter is kinda pointless.  */
 148   gdb_assert (!top_level || !current_interpreter);
 149   gdb_assert (!top_level || !top_level_interpreter_ptr);
 150
 151   if (current_interpreter != NULL)
 152     {
 153       do_all_continuations ();
 154       ui_out_flush (uiout);
 155       if (current_interpreter->procs->suspend_proc
 156           && !current_interpreter->procs->suspend_proc (current_interpreter->
 157                                                         data))
 158         {
 159           error (_("Could not suspend interpreter \"%s\"."),
 160                  current_interpreter->name);
 161         }
 162     }
 163   else
 164     {
 165       first_time = 1;
 166     }
 167
 168   current_interpreter = interp;
 169   if (top_level)
 170     top_level_interpreter_ptr = interp;
 171
 172   /* We use interpreter_p for the "set interpreter" variable, so we need
 173      to make sure we have a malloc'ed copy for the set command to free.  */
 174   if (interpreter_p != NULL
 175       && strcmp (current_interpreter->name, interpreter_p) != 0)
 176     {
 177       xfree (interpreter_p);
 178
 179       interpreter_p = xstrdup (current_interpreter->name);
 180     }
 181
 182   uiout = interp->interpreter_out;
 183
 184   /* Run the init proc.  If it fails, try to restore the old interp.  */
 185
 186   if (!interp->inited)
 187     {
 188       if (interp->procs->init_proc != NULL)
 189         {
 190           interp->data = interp->procs->init_proc (top_level);
 191         }
 192       interp->inited = 1;
 193     }
 194
 195   /* Clear out any installed interpreter hooks/event handlers.  */
 196   clear_interpreter_hooks ();
 197
 198   if (interp->procs->resume_proc != NULL
 199       && (!interp->procs->resume_proc (interp->data)))
 200     {
 201       if (old_interp == NULL || !interp_set (old_interp, 0))
 202         internal_error (__FILE__, __LINE__,
 203                         _("Failed to initialize new interp \"%s\" %s"),
 204                         interp->name, "and could not restore old interp!\n");
 205       return 0;
 206     }
 207
 208   /* Finally, put up the new prompt to show that we are indeed here.
 209      Also, display_gdb_prompt for the console does some readline magic
 210      which is needed for the console interpreter, at least...  */
 211
 212   if (!first_time)
 213     {
 214       if (!interp_quiet_p (interp))
 215         {
 216           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 217                    interp->name);
 218           ui_out_text (uiout, buffer);
 219         }
 220       display_gdb_prompt (NULL);
 221     }
 222
 223   return 1;
 224 }
 225
 226 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 227    interpreter exists, return NULL, otherwise return a pointer to the
 228    interpreter.  */
 229 struct interp *
 230 interp_lookup (const char *name)
 231 {
 232   struct interp *interp;
 233
 234   if (name == NULL || strlen (name) == 0)
 235     return NULL;
 236
 237   for (interp = interp_list; interp != NULL; interp = interp->next)
 238     {
 239       if (strcmp (interp->name, name) == 0)
 240         return interp;
 241     }
 242
 243   return NULL;
 244 }
 245
 246 /* Returns the current interpreter.  */
 247
 248 struct ui_out *
 249 interp_ui_out (struct interp *interp)
 250 {
 251   if (interp != NULL)
 252     return interp->interpreter_out;
 253
 254   return current_interpreter->interpreter_out;
 255 }
 256
 257 /* Returns true if the current interp is the passed in name.  */
 258 int
 259 current_interp_named_p (const char *interp_name)
 260 {
 261   if (current_interpreter)
 262     return (strcmp (current_interpreter->name, interp_name) == 0);
 263
 264   return 0;
 265 }
 266
 267 /* This is called in display_gdb_prompt.  If the proc returns a zero
 268    value, display_gdb_prompt will return without displaying the
 269    prompt.  */
 270 int
 271 current_interp_display_prompt_p (void)
 272 {
 273   if (current_interpreter == NULL
 274       || current_interpreter->procs->prompt_proc_p == NULL)
 275     return 0;
 276   else
 277     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 278                                                       data);
 279 }
 280
 281 /* Run the current command interpreter's main loop.  */
 282 void
 283 current_interp_command_loop (void)
 284 {
 285   /* Somewhat messy.  For the moment prop up all the old ways of
 286      selecting the command loop.  `deprecated_command_loop_hook'
 287      should be deprecated.  */
 288   if (deprecated_command_loop_hook != NULL)
 289     deprecated_command_loop_hook ();
 290   else if (current_interpreter != NULL
 291            && current_interpreter->procs->command_loop_proc != NULL)
 292     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 293   else
 294     cli_command_loop ();
 295 }
 296
 297 int
 298 interp_quiet_p (struct interp *interp)
 299 {
 300   if (interp != NULL)
 301     return interp->quiet_p;
 302   else
 303     return current_interpreter->quiet_p;
 304 }
 305
 306 static int
 307 interp_set_quiet (struct interp *interp, int quiet)
 308 {
 309   int old_val = interp->quiet_p;
 310
 311   interp->quiet_p = quiet;
 312   return old_val;
 313 }
 314
 315 /* interp_exec - This executes COMMAND_STR in the current
 316    interpreter.  */
 317 int
 318 interp_exec_p (struct interp *interp)
 319 {
 320   return interp->procs->exec_proc != NULL;
 321 }
 322
 323 struct gdb_exception
 324 interp_exec (struct interp *interp, const char *command_str)
 325 {
 326   if (interp->procs->exec_proc != NULL)
 327     {
 328       return interp->procs->exec_proc (interp->data, command_str);
 329     }
 330   return exception_none;
 331 }
 332
 333 /* A convenience routine that nulls out all the common command hooks.
 334    Use it when removing your interpreter in its suspend proc.  */
 335 void
 336 clear_interpreter_hooks (void)
 337 {
 338   deprecated_init_ui_hook = 0;
 339   deprecated_print_frame_info_listing_hook = 0;
 340   /*print_frame_more_info_hook = 0; */
 341   deprecated_query_hook = 0;
 342   deprecated_warning_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_context_hook = 0;
 349   deprecated_target_wait_hook = 0;
 350   deprecated_call_command_hook = 0;
 351   deprecated_error_begin_hook = 0;
 352   deprecated_command_loop_hook = 0;
 353 }
 354
 355 /* This is a lazy init routine, called the first time the interpreter
 356    module is used.  I put it here just in case, but I haven't thought
 357    of a use for it yet.  I will probably bag it soon, since I don't
 358    think it will be necessary.  */
 359 static void
 360 initialize_interps (void)
 361 {
 362   interpreter_initialized = 1;
 363   /* Don't know if anything needs to be done here...  */
 364 }
 365
 366 static void
 367 interpreter_exec_cmd (char *args, int from_tty)
 368 {
 369   struct interp *old_interp, *interp_to_use;
 370   char **prules = NULL;
 371   char **trule = NULL;
 372   unsigned int nrules;
 373   unsigned int i;
 374   int old_quiet, use_quiet;
 375
 376   if (args == NULL)
 377     error_no_arg (_("interpreter-exec command"));
 378
 379   prules = gdb_buildargv (args);
 380   make_cleanup_freeargv (prules);
 381
 382   nrules = 0;
 383   for (trule = prules; *trule != NULL; trule++)
 384     nrules++;
 385
 386   if (nrules < 2)
 387     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 388
 389   old_interp = current_interpreter;
 390
 391   interp_to_use = interp_lookup (prules[0]);
 392   if (interp_to_use == NULL)
 393     error (_("Could not find interpreter \"%s\"."), prules[0]);
 394
 395   /* Temporarily set interpreters quiet.  */
 396   old_quiet = interp_set_quiet (old_interp, 1);
 397   use_quiet = interp_set_quiet (interp_to_use, 1);
 398
 399   if (!interp_set (interp_to_use, 0))
 400     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 401
 402   for (i = 1; i < nrules; i++)
 403     {
 404       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 405
 406       if (e.reason < 0)
 407         {
 408           interp_set (old_interp, 0);
 409           interp_set_quiet (interp_to_use, use_quiet);
 410           interp_set_quiet (old_interp, old_quiet);
 411           error (_("error in command: \"%s\"."), prules[i]);
 412         }
 413     }
 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 }
 419
 420 /* List the possible interpreters which could complete the given text.  */
 421 static char **
 422 interpreter_completer (struct cmd_list_element *ignore, char *text, char *word)
 423 {
 424   int alloced = 0;
 425   int textlen;
 426   int num_matches;
 427   char **matches;
 428   struct interp *interp;
 429
 430   /* We expect only a very limited number of interpreters, so just
 431      allocate room for all of them plus one for the last that must be NULL
 432      to correctly end the list.  */
 433   for (interp = interp_list; interp != NULL; interp = interp->next)
 434     ++alloced;
 435   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 436
 437   num_matches = 0;
 438   textlen = strlen (text);
 439   for (interp = interp_list; interp != NULL; interp = interp->next)
 440     {
 441       if (strncmp (interp->name, text, textlen) == 0)
 442         {
 443           matches[num_matches] =
 444             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 445           if (word == text)
 446             strcpy (matches[num_matches], interp->name);
 447           else if (word > text)
 448             {
 449               /* Return some portion of interp->name.  */
 450               strcpy (matches[num_matches], interp->name + (word - text));
 451             }
 452           else
 453             {
 454               /* Return some of text plus interp->name.  */
 455               strncpy (matches[num_matches], word, text - word);
 456               matches[num_matches][text - word] = '\0';
 457               strcat (matches[num_matches], interp->name);
 458             }
 459           ++num_matches;
 460         }
 461     }
 462
 463   if (num_matches == 0)
 464     {
 465       xfree (matches);
 466       matches = NULL;
 467     }
 468
 469   return matches;
 470 }
 471
 472 struct interp *
 473 top_level_interpreter (void)
 474 {
 475   return top_level_interpreter_ptr;
 476 }
 477
 478 void *
 479 top_level_interpreter_data (void)
 480 {
 481   gdb_assert (top_level_interpreter_ptr);
 482   return top_level_interpreter_ptr->data;
 483 }
 484
 485 /* This just adds the "interpreter-exec" command.  */
 486 void
 487 _initialize_interpreter (void)
 488 {
 489   struct cmd_list_element *c;
 490
 491   c = add_cmd ("interpreter-exec", class_support,
 492                interpreter_exec_cmd, _("\
 493 Execute a command in an interpreter.  It takes two arguments:\n\
 494 The first argument is the name of the interpreter to use.\n\
 495 The second argument is the command to execute.\n"), &cmdlist);
 496   set_cmd_completer (c, interpreter_completer);
 497 }