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_assert.h"
  41 #include "top.h"                /* For command_loop.  */
  42 #include "exceptions.h"
  43
  44 struct interp
  45 {
  46   /* This is the name in "-i=" and set interpreter. */
  47   const char *name;
  48
  49   /* Interpreters are stored in a linked list, this is the next
  50      one...  */
  51   struct interp *next;
  52
  53   /* This is a cookie that an instance of the interpreter can use.
  54      This is a bit confused right now as the exact initialization
  55      sequence for it, and how it relates to the interpreter's uiout
  56      object is a bit confused.  */
  57   void *data;
  58
  59   /* Has the init_proc been run? */
  60   int inited;
  61
  62   /* This is the ui_out used to collect results for this interpreter.
  63      It can be a formatter for stdout, as is the case for the console
  64      & mi outputs, or it might be a result formatter.  */
  65   struct ui_out *interpreter_out;
  66
  67   const struct interp_procs *procs;
  68   int quiet_p;
  69 };
  70
  71 /* Functions local to this file. */
  72 static void initialize_interps (void);
  73 static char **interpreter_completer (char *text, char *word);
  74
  75 /* The magic initialization routine for this module. */
  76
  77 void _initialize_interpreter (void);
  78
  79 /* Variables local to this file: */
  80
  81 static struct interp *interp_list = NULL;
  82 static struct interp *current_interpreter = NULL;
  83 static struct interp *top_level_interpreter_ptr = NULL;
  84
  85 static int interpreter_initialized = 0;
  86
  87 /* interp_new - This allocates space for a new interpreter,
  88    fills the fields from the inputs, and returns a pointer to the
  89    interpreter. */
  90 struct interp *
  91 interp_new (const char *name, void *data, struct ui_out *uiout,
  92             const struct interp_procs *procs)
  93 {
  94   struct interp *new_interp;
  95
  96   new_interp = XMALLOC (struct interp);
  97
  98   new_interp->name = xstrdup (name);
  99   new_interp->data = data;
 100   new_interp->interpreter_out = uiout;
 101   new_interp->quiet_p = 0;
 102   new_interp->procs = procs;
 103   new_interp->inited = 0;
 104
 105   return new_interp;
 106 }
 107
 108 /* Add interpreter INTERP to the gdb interpreter list.  The
 109    interpreter must not have previously been added.  */
 110 void
 111 interp_add (struct interp *interp)
 112 {
 113   if (!interpreter_initialized)
 114     initialize_interps ();
 115
 116   gdb_assert (interp_lookup (interp->name) == NULL);
 117
 118   interp->next = interp_list;
 119   interp_list = interp;
 120 }
 121
 122 /* This sets the current interpreter to be INTERP.  If INTERP has not
 123    been initialized, then this will also run the init proc.  If the
 124    init proc is successful, return 1, if it fails, set the old
 125    interpreter back in place and return 0.  If we can't restore the
 126    old interpreter, then raise an internal error, since we are in
 127    pretty bad shape at this point.
 128
 129    The TOP_LEVEL parameter tells if this new interpreter is
 130    the top-level one.  The top-level is what is requested
 131    on the command line, and is responsible for reporting general
 132    notification about target state changes.  For example, if
 133    MI is the top-level interpreter, then it will always report
 134    events such as target stops and new thread creation, even if they
 135    are caused by CLI commands.  */
 136 int
 137 interp_set (struct interp *interp, int top_level)
 138 {
 139   struct interp *old_interp = current_interpreter;
 140   int first_time = 0;
 141   char buffer[64];
 142
 143   /* If we already have an interpreter, then trying to
 144      set top level interpreter is kinda pointless.  */
 145   gdb_assert (!top_level || !current_interpreter);
 146   gdb_assert (!top_level || !top_level_interpreter_ptr);
 147
 148   if (current_interpreter != NULL)
 149     {
 150       do_all_continuations ();
 151       ui_out_flush (uiout);
 152       if (current_interpreter->procs->suspend_proc
 153           && !current_interpreter->procs->suspend_proc (current_interpreter->
 154                                                         data))
 155         {
 156           error (_("Could not suspend interpreter \"%s\"."),
 157                  current_interpreter->name);
 158         }
 159     }
 160   else
 161     {
 162       first_time = 1;
 163     }
 164
 165   current_interpreter = interp;
 166   if (top_level)
 167     top_level_interpreter_ptr = interp;
 168
 169   /* We use interpreter_p for the "set interpreter" variable, so we need
 170      to make sure we have a malloc'ed copy for the set command to free. */
 171   if (interpreter_p != NULL
 172       && strcmp (current_interpreter->name, interpreter_p) != 0)
 173     {
 174       xfree (interpreter_p);
 175
 176       interpreter_p = xstrdup (current_interpreter->name);
 177     }
 178
 179   uiout = interp->interpreter_out;
 180
 181   /* Run the init proc.  If it fails, try to restore the old interp. */
 182
 183   if (!interp->inited)
 184     {
 185       if (interp->procs->init_proc != NULL)
 186         {
 187           interp->data = interp->procs->init_proc (top_level);
 188         }
 189       interp->inited = 1;
 190     }
 191
 192   /* Clear out any installed interpreter hooks/event handlers.  */
 193   clear_interpreter_hooks ();
 194
 195   if (interp->procs->resume_proc != NULL
 196       && (!interp->procs->resume_proc (interp->data)))
 197     {
 198       if (old_interp == NULL || !interp_set (old_interp, 0))
 199         internal_error (__FILE__, __LINE__,
 200                         _("Failed to initialize new interp \"%s\" %s"),
 201                         interp->name, "and could not restore old interp!\n");
 202       return 0;
 203     }
 204
 205   /* Finally, put up the new prompt to show that we are indeed here.
 206      Also, display_gdb_prompt for the console does some readline magic
 207      which is needed for the console interpreter, at least... */
 208
 209   if (!first_time)
 210     {
 211       if (!interp_quiet_p (interp))
 212         {
 213           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 214                    interp->name);
 215           ui_out_text (uiout, buffer);
 216         }
 217       display_gdb_prompt (NULL);
 218     }
 219
 220   return 1;
 221 }
 222
 223 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 224    interpreter exists, return NULL, otherwise return a pointer to the
 225    interpreter.  */
 226 struct interp *
 227 interp_lookup (const char *name)
 228 {
 229   struct interp *interp;
 230
 231   if (name == NULL || strlen (name) == 0)
 232     return NULL;
 233
 234   for (interp = interp_list; interp != NULL; interp = interp->next)
 235     {
 236       if (strcmp (interp->name, name) == 0)
 237         return interp;
 238     }
 239
 240   return NULL;
 241 }
 242
 243 /* Returns the current interpreter. */
 244
 245 struct ui_out *
 246 interp_ui_out (struct interp *interp)
 247 {
 248   if (interp != NULL)
 249     return interp->interpreter_out;
 250
 251   return current_interpreter->interpreter_out;
 252 }
 253
 254 /* Returns true if the current interp is the passed in name. */
 255 int
 256 current_interp_named_p (const char *interp_name)
 257 {
 258   if (current_interpreter)
 259     return (strcmp (current_interpreter->name, interp_name) == 0);
 260
 261   return 0;
 262 }
 263
 264 /* This is called in display_gdb_prompt.  If the proc returns a zero
 265    value, display_gdb_prompt will return without displaying the
 266    prompt.  */
 267 int
 268 current_interp_display_prompt_p (void)
 269 {
 270   if (current_interpreter == NULL
 271       || current_interpreter->procs->prompt_proc_p == NULL)
 272     return 0;
 273   else
 274     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 275                                                       data);
 276 }
 277
 278 /* Run the current command interpreter's main loop.  */
 279 void
 280 current_interp_command_loop (void)
 281 {
 282   /* Somewhat messy.  For the moment prop up all the old ways of
 283      selecting the command loop.  `deprecated_command_loop_hook'
 284      should be deprecated.  */
 285   if (deprecated_command_loop_hook != NULL)
 286     deprecated_command_loop_hook ();
 287   else if (current_interpreter != NULL
 288            && current_interpreter->procs->command_loop_proc != NULL)
 289     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 290   else
 291     cli_command_loop ();
 292 }
 293
 294 int
 295 interp_quiet_p (struct interp *interp)
 296 {
 297   if (interp != NULL)
 298     return interp->quiet_p;
 299   else
 300     return current_interpreter->quiet_p;
 301 }
 302
 303 static int
 304 interp_set_quiet (struct interp *interp, int quiet)
 305 {
 306   int old_val = interp->quiet_p;
 307   interp->quiet_p = quiet;
 308   return old_val;
 309 }
 310
 311 /* interp_exec - This executes COMMAND_STR in the current
 312    interpreter. */
 313 int
 314 interp_exec_p (struct interp *interp)
 315 {
 316   return interp->procs->exec_proc != NULL;
 317 }
 318
 319 struct gdb_exception
 320 interp_exec (struct interp *interp, const char *command_str)
 321 {
 322   if (interp->procs->exec_proc != NULL)
 323     {
 324       return interp->procs->exec_proc (interp->data, command_str);
 325     }
 326   return exception_none;
 327 }
 328
 329 /* A convenience routine that nulls out all the common command hooks.
 330    Use it when removing your interpreter in its suspend proc.  */
 331 void
 332 clear_interpreter_hooks (void)
 333 {
 334   deprecated_init_ui_hook = 0;
 335   deprecated_print_frame_info_listing_hook = 0;
 336   /*print_frame_more_info_hook = 0; */
 337   deprecated_query_hook = 0;
 338   deprecated_warning_hook = 0;
 339   deprecated_interactive_hook = 0;
 340   deprecated_readline_begin_hook = 0;
 341   deprecated_readline_hook = 0;
 342   deprecated_readline_end_hook = 0;
 343   deprecated_register_changed_hook = 0;
 344   deprecated_memory_changed_hook = 0;
 345   deprecated_context_hook = 0;
 346   deprecated_target_wait_hook = 0;
 347   deprecated_call_command_hook = 0;
 348   deprecated_error_hook = 0;
 349   deprecated_error_begin_hook = 0;
 350   deprecated_command_loop_hook = 0;
 351 }
 352
 353 /* This is a lazy init routine, called the first time the interpreter
 354    module is used.  I put it here just in case, but I haven't thought
 355    of a use for it yet.  I will probably bag it soon, since I don't
 356    think it will be necessary.  */
 357 static void
 358 initialize_interps (void)
 359 {
 360   interpreter_initialized = 1;
 361   /* Don't know if anything needs to be done here... */
 362 }
 363
 364 static void
 365 interpreter_exec_cmd (char *args, int from_tty)
 366 {
 367   struct interp *old_interp, *interp_to_use;
 368   char **prules = NULL;
 369   char **trule = NULL;
 370   unsigned int nrules;
 371   unsigned int i;
 372   int old_quiet, use_quiet;
 373
 374   prules = buildargv (args);
 375   if (prules == NULL)
 376     {
 377       error (_("unable to parse arguments"));
 378     }
 379
 380   nrules = 0;
 381   if (prules != NULL)
 382     {
 383       for (trule = prules; *trule != NULL; trule++)
 384         {
 385           nrules++;
 386         }
 387     }
 388
 389   if (nrules < 2)
 390     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 391
 392   old_interp = current_interpreter;
 393
 394   interp_to_use = interp_lookup (prules[0]);
 395   if (interp_to_use == NULL)
 396     error (_("Could not find interpreter \"%s\"."), prules[0]);
 397
 398   /* Temporarily set interpreters quiet */
 399   old_quiet = interp_set_quiet (old_interp, 1);
 400   use_quiet = interp_set_quiet (interp_to_use, 1);
 401
 402   if (!interp_set (interp_to_use, 0))
 403     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 404
 405   for (i = 1; i < nrules; i++)
 406     {
 407       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 408       if (e.reason < 0)
 409         {
 410           interp_set (old_interp, 0);
 411           interp_set_quiet (interp_to_use, use_quiet);
 412           interp_set_quiet (old_interp, old_quiet);
 413           error (_("error in command: \"%s\"."), prules[i]);
 414         }
 415     }
 416
 417   interp_set (old_interp, 0);
 418   interp_set_quiet (interp_to_use, use_quiet);
 419   interp_set_quiet (old_interp, old_quiet);
 420 }
 421
 422 /* List the possible interpreters which could complete the given text. */
 423 static char **
 424 interpreter_completer (char *text, char *word)
 425 {
 426   int alloced = 0;
 427   int textlen;
 428   int num_matches;
 429   char **matches;
 430   struct interp *interp;
 431
 432   /* We expect only a very limited number of interpreters, so just
 433      allocate room for all of them plus one for the last that must be NULL
 434      to correctly end the list. */
 435   for (interp = interp_list; interp != NULL; interp = interp->next)
 436     ++alloced;
 437   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 438
 439   num_matches = 0;
 440   textlen = strlen (text);
 441   for (interp = interp_list; interp != NULL; interp = interp->next)
 442     {
 443       if (strncmp (interp->name, text, textlen) == 0)
 444         {
 445           matches[num_matches] =
 446             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 447           if (word == text)
 448             strcpy (matches[num_matches], interp->name);
 449           else if (word > text)
 450             {
 451               /* Return some portion of interp->name */
 452               strcpy (matches[num_matches], interp->name + (word - text));
 453             }
 454           else
 455             {
 456               /* Return some of text plus interp->name */
 457               strncpy (matches[num_matches], word, text - word);
 458               matches[num_matches][text - word] = '\0';
 459               strcat (matches[num_matches], interp->name);
 460             }
 461           ++num_matches;
 462         }
 463     }
 464
 465   if (num_matches == 0)
 466     {
 467       xfree (matches);
 468       matches = NULL;
 469     }
 470
 471   return matches;
 472 }
 473
 474 struct interp *
 475 top_level_interpreter (void)
 476 {
 477   return top_level_interpreter_ptr;
 478 }
 479
 480 void *
 481 top_level_interpreter_data (void)
 482 {
 483   gdb_assert (top_level_interpreter_ptr);
 484   return top_level_interpreter_ptr->data;
 485 }
 486
 487 /* This just adds the "interpreter-exec" command.  */
 488 void
 489 _initialize_interpreter (void)
 490 {
 491   struct cmd_list_element *c;
 492
 493   c = add_cmd ("interpreter-exec", class_support,
 494                interpreter_exec_cmd, _("\
 495 Execute a command in an interpreter.  It takes two arguments:\n\
 496 The first argument is the name of the interpreter to use.\n\
 497 The second argument is the command to execute.\n"), &cmdlist);
 498   set_cmd_completer (c, interpreter_completer);
 499 }