gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright (C) 2000, 2002, 2003 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 2 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, write to the Free Software
  21    Foundation, Inc., 51 Franklin Street, Fifth Floor,
  22    Boston, MA 02110-1301, USA. */
  23
  24 /* This is just a first cut at separating out the "interpreter"
  25    functions of gdb into self-contained modules.  There are a couple
  26    of open areas that need to be sorted out:
  27
  28    1) The interpreter explicitly contains a UI_OUT, and can insert itself
  29    into the event loop, but it doesn't explicitly contain hooks for readline.
  30    I did this because it seems to me many interpreters won't want to use
  31    the readline command interface, and it is probably simpler to just let
  32    them take over the input in their resume proc.  */
  33
  34 #include "defs.h"
  35 #include "gdbcmd.h"
  36 #include "ui-out.h"
  37 #include "event-loop.h"
  38 #include "event-top.h"
  39 #include "interps.h"
  40 #include "completer.h"
  41 #include "gdb_string.h"
  42 #include "gdb-events.h"
  43 #include "gdb_assert.h"
  44 #include "top.h"                /* For command_loop.  */
  45 #include "exceptions.h"
  46
  47 struct interp
  48 {
  49   /* This is the name in "-i=" and set interpreter. */
  50   const char *name;
  51
  52   /* Interpreters are stored in a linked list, this is the next
  53      one...  */
  54   struct interp *next;
  55
  56   /* This is a cookie that an instance of the interpreter can use.
  57      This is a bit confused right now as the exact initialization
  58      sequence for it, and how it relates to the interpreter's uiout
  59      object is a bit confused.  */
  60   void *data;
  61
  62   /* Has the init_proc been run? */
  63   int inited;
  64
  65   /* This is the ui_out used to collect results for this interpreter.
  66      It can be a formatter for stdout, as is the case for the console
  67      & mi outputs, or it might be a result formatter.  */
  68   struct ui_out *interpreter_out;
  69
  70   const struct interp_procs *procs;
  71   int quiet_p;
  72 };
  73
  74 /* Functions local to this file. */
  75 static void initialize_interps (void);
  76 static char **interpreter_completer (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
  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 int
 131 interp_set (struct interp *interp)
 132 {
 133   struct interp *old_interp = current_interpreter;
 134   int first_time = 0;
 135
 136
 137   char buffer[64];
 138
 139   if (current_interpreter != NULL)
 140     {
 141       do_all_continuations ();
 142       ui_out_flush (uiout);
 143       if (current_interpreter->procs->suspend_proc
 144           && !current_interpreter->procs->suspend_proc (current_interpreter->
 145                                                         data))
 146         {
 147           error (_("Could not suspend interpreter \"%s\"."),
 148                  current_interpreter->name);
 149         }
 150     }
 151   else
 152     {
 153       first_time = 1;
 154     }
 155
 156   current_interpreter = interp;
 157
 158   /* We use interpreter_p for the "set interpreter" variable, so we need
 159      to make sure we have a malloc'ed copy for the set command to free. */
 160   if (interpreter_p != NULL
 161       && strcmp (current_interpreter->name, interpreter_p) != 0)
 162     {
 163       xfree (interpreter_p);
 164
 165       interpreter_p = xstrdup (current_interpreter->name);
 166     }
 167
 168   uiout = interp->interpreter_out;
 169
 170   /* Run the init proc.  If it fails, try to restore the old interp. */
 171
 172   if (!interp->inited)
 173     {
 174       if (interp->procs->init_proc != NULL)
 175         {
 176           interp->data = interp->procs->init_proc ();
 177         }
 178       interp->inited = 1;
 179     }
 180
 181   /* Clear out any installed interpreter hooks/event handlers.  */
 182   clear_interpreter_hooks ();
 183
 184   if (interp->procs->resume_proc != NULL
 185       && (!interp->procs->resume_proc (interp->data)))
 186     {
 187       if (old_interp == NULL || !interp_set (old_interp))
 188         internal_error (__FILE__, __LINE__,
 189                         _("Failed to initialize new interp \"%s\" %s"),
 190                         interp->name, "and could not restore old interp!\n");
 191       return 0;
 192     }
 193
 194   /* Finally, put up the new prompt to show that we are indeed here.
 195      Also, display_gdb_prompt for the console does some readline magic
 196      which is needed for the console interpreter, at least... */
 197
 198   if (!first_time)
 199     {
 200       if (!interp_quiet_p (interp))
 201         {
 202           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 203                    interp->name);
 204           ui_out_text (uiout, buffer);
 205         }
 206       display_gdb_prompt (NULL);
 207     }
 208
 209   return 1;
 210 }
 211
 212 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 213    interpreter exists, return NULL, otherwise return a pointer to the
 214    interpreter.  */
 215 struct interp *
 216 interp_lookup (const char *name)
 217 {
 218   struct interp *interp;
 219
 220   if (name == NULL || strlen (name) == 0)
 221     return NULL;
 222
 223   for (interp = interp_list; interp != NULL; interp = interp->next)
 224     {
 225       if (strcmp (interp->name, name) == 0)
 226         return interp;
 227     }
 228
 229   return NULL;
 230 }
 231
 232 /* Returns the current interpreter. */
 233
 234 struct ui_out *
 235 interp_ui_out (struct interp *interp)
 236 {
 237   if (interp != NULL)
 238     return interp->interpreter_out;
 239
 240   return current_interpreter->interpreter_out;
 241 }
 242
 243 /* Returns true if the current interp is the passed in name. */
 244 int
 245 current_interp_named_p (const char *interp_name)
 246 {
 247   if (current_interpreter)
 248     return (strcmp (current_interpreter->name, interp_name) == 0);
 249
 250   return 0;
 251 }
 252
 253 /* This is called in display_gdb_prompt.  If the proc returns a zero
 254    value, display_gdb_prompt will return without displaying the
 255    prompt.  */
 256 int
 257 current_interp_display_prompt_p (void)
 258 {
 259   if (current_interpreter == NULL
 260       || current_interpreter->procs->prompt_proc_p == NULL)
 261     return 0;
 262   else
 263     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 264                                                       data);
 265 }
 266
 267 /* Run the current command interpreter's main loop.  */
 268 void
 269 current_interp_command_loop (void)
 270 {
 271   /* Somewhat messy.  For the moment prop up all the old ways of
 272      selecting the command loop.  `deprecated_command_loop_hook'
 273      should be deprecated.  */
 274   if (deprecated_command_loop_hook != NULL)
 275     deprecated_command_loop_hook ();
 276   else if (current_interpreter != NULL
 277            && current_interpreter->procs->command_loop_proc != NULL)
 278     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 279   else
 280     cli_command_loop ();
 281 }
 282
 283 int
 284 interp_quiet_p (struct interp *interp)
 285 {
 286   if (interp != NULL)
 287     return interp->quiet_p;
 288   else
 289     return current_interpreter->quiet_p;
 290 }
 291
 292 static int
 293 interp_set_quiet (struct interp *interp, int quiet)
 294 {
 295   int old_val = interp->quiet_p;
 296   interp->quiet_p = quiet;
 297   return old_val;
 298 }
 299
 300 /* interp_exec - This executes COMMAND_STR in the current
 301    interpreter. */
 302 int
 303 interp_exec_p (struct interp *interp)
 304 {
 305   return interp->procs->exec_proc != NULL;
 306 }
 307
 308 struct gdb_exception
 309 interp_exec (struct interp *interp, const char *command_str)
 310 {
 311   if (interp->procs->exec_proc != NULL)
 312     {
 313       return interp->procs->exec_proc (interp->data, command_str);
 314     }
 315   return exception_none;
 316 }
 317
 318 /* A convenience routine that nulls out all the common command hooks.
 319    Use it when removing your interpreter in its suspend proc.  */
 320 void
 321 clear_interpreter_hooks (void)
 322 {
 323   deprecated_init_ui_hook = 0;
 324   deprecated_print_frame_info_listing_hook = 0;
 325   /*print_frame_more_info_hook = 0; */
 326   deprecated_query_hook = 0;
 327   deprecated_warning_hook = 0;
 328   deprecated_create_breakpoint_hook = 0;
 329   deprecated_delete_breakpoint_hook = 0;
 330   deprecated_modify_breakpoint_hook = 0;
 331   deprecated_interactive_hook = 0;
 332   deprecated_registers_changed_hook = 0;
 333   deprecated_readline_begin_hook = 0;
 334   deprecated_readline_hook = 0;
 335   deprecated_readline_end_hook = 0;
 336   deprecated_register_changed_hook = 0;
 337   deprecated_memory_changed_hook = 0;
 338   deprecated_context_hook = 0;
 339   deprecated_target_wait_hook = 0;
 340   deprecated_call_command_hook = 0;
 341   deprecated_error_hook = 0;
 342   deprecated_error_begin_hook = 0;
 343   deprecated_command_loop_hook = 0;
 344   clear_gdb_event_hooks ();
 345 }
 346
 347 /* This is a lazy init routine, called the first time the interpreter
 348    module is used.  I put it here just in case, but I haven't thought
 349    of a use for it yet.  I will probably bag it soon, since I don't
 350    think it will be necessary.  */
 351 static void
 352 initialize_interps (void)
 353 {
 354   interpreter_initialized = 1;
 355   /* Don't know if anything needs to be done here... */
 356 }
 357
 358 static void
 359 interpreter_exec_cmd (char *args, int from_tty)
 360 {
 361   struct interp *old_interp, *interp_to_use;
 362   char **prules = NULL;
 363   char **trule = NULL;
 364   unsigned int nrules;
 365   unsigned int i;
 366   int old_quiet, use_quiet;
 367
 368   prules = buildargv (args);
 369   if (prules == NULL)
 370     {
 371       error (_("unable to parse arguments"));
 372     }
 373
 374   nrules = 0;
 375   if (prules != NULL)
 376     {
 377       for (trule = prules; *trule != NULL; trule++)
 378         {
 379           nrules++;
 380         }
 381     }
 382
 383   if (nrules < 2)
 384     error (_("usage: interpreter-exec <interpreter> [ <command> ... ]"));
 385
 386   old_interp = current_interpreter;
 387
 388   interp_to_use = interp_lookup (prules[0]);
 389   if (interp_to_use == NULL)
 390     error (_("Could not find interpreter \"%s\"."), prules[0]);
 391
 392   /* Temporarily set interpreters quiet */
 393   old_quiet = interp_set_quiet (old_interp, 1);
 394   use_quiet = interp_set_quiet (interp_to_use, 1);
 395
 396   if (!interp_set (interp_to_use))
 397     error (_("Could not switch to interpreter \"%s\"."), prules[0]);
 398
 399   for (i = 1; i < nrules; i++)
 400     {
 401       struct gdb_exception e = interp_exec (interp_to_use, prules[i]);
 402       if (e.reason < 0)
 403         {
 404           interp_set (old_interp);
 405           interp_set_quiet (interp_to_use, old_quiet);
 406           error (_("error in command: \"%s\"."), prules[i]);
 407           break;
 408         }
 409     }
 410
 411   interp_set (old_interp);
 412   interp_set_quiet (interp_to_use, use_quiet);
 413   interp_set_quiet (old_interp, old_quiet);
 414 }
 415
 416 /* List the possible interpreters which could complete the given text. */
 417 static char **
 418 interpreter_completer (char *text, char *word)
 419 {
 420   int alloced = 0;
 421   int textlen;
 422   int num_matches;
 423   char **matches;
 424   struct interp *interp;
 425
 426   /* We expect only a very limited number of interpreters, so just
 427      allocate room for all of them plus one for the last that must be NULL
 428      to correctly end the list. */
 429   for (interp = interp_list; interp != NULL; interp = interp->next)
 430     ++alloced;
 431   matches = (char **) xcalloc (alloced + 1, sizeof (char *));
 432
 433   num_matches = 0;
 434   textlen = strlen (text);
 435   for (interp = interp_list; interp != NULL; interp = interp->next)
 436     {
 437       if (strncmp (interp->name, text, textlen) == 0)
 438         {
 439           matches[num_matches] =
 440             (char *) xmalloc (strlen (word) + strlen (interp->name) + 1);
 441           if (word == text)
 442             strcpy (matches[num_matches], interp->name);
 443           else if (word > text)
 444             {
 445               /* Return some portion of interp->name */
 446               strcpy (matches[num_matches], interp->name + (word - text));
 447             }
 448           else
 449             {
 450               /* Return some of text plus interp->name */
 451               strncpy (matches[num_matches], word, text - word);
 452               matches[num_matches][text - word] = '\0';
 453               strcat (matches[num_matches], interp->name);
 454             }
 455           ++num_matches;
 456         }
 457     }
 458
 459   if (num_matches == 0)
 460     {
 461       xfree (matches);
 462       matches = NULL;
 463     }
 464
 465   return matches;
 466 }
 467
 468 /* This just adds the "interpreter-exec" command.  */
 469 void
 470 _initialize_interpreter (void)
 471 {
 472   struct cmd_list_element *c;
 473
 474   c = add_cmd ("interpreter-exec", class_support,
 475                interpreter_exec_cmd, _("\
 476 Execute a command in an interpreter.  It takes two arguments:\n\
 477 The first argument is the name of the interpreter to use.\n\
 478 The second argument is the command to execute.\n"), &cmdlist);
 479   set_cmd_completer (c, interpreter_completer);
 480 }