gdb/interps.c

   1 /* Manages interpreters for GDB, the GNU debugger.
   2
   3    Copyright 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., 59 Temple Place - Suite 330,
  22    Boston, MA 02111-1307, 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
  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 (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
  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 int
 130 interp_set (struct interp *interp)
 131 {
 132   struct interp *old_interp = current_interpreter;
 133   int first_time = 0;
 134
 135
 136   char buffer[64];
 137
 138   if (current_interpreter != NULL)
 139     {
 140       do_all_continuations ();
 141       ui_out_flush (uiout);
 142       if (current_interpreter->procs->suspend_proc
 143           && !current_interpreter->procs->suspend_proc (current_interpreter->
 144                                                         data))
 145         {
 146           error ("Could not suspend interpreter \"%s\"\n",
 147                  current_interpreter->name);
 148         }
 149     }
 150   else
 151     {
 152       first_time = 1;
 153     }
 154
 155   current_interpreter = interp;
 156
 157   /* We use interpreter_p for the "set interpreter" variable, so we need
 158      to make sure we have a malloc'ed copy for the set command to free. */
 159   if (interpreter_p != NULL
 160       && strcmp (current_interpreter->name, interpreter_p) != 0)
 161     {
 162       xfree (interpreter_p);
 163
 164       interpreter_p = xstrdup (current_interpreter->name);
 165     }
 166
 167   uiout = interp->interpreter_out;
 168
 169   /* Run the init proc.  If it fails, try to restore the old interp. */
 170
 171   if (!interp->inited)
 172     {
 173       if (interp->procs->init_proc != NULL)
 174         {
 175           interp->data = interp->procs->init_proc ();
 176         }
 177       interp->inited = 1;
 178     }
 179
 180   /* Clear out any installed interpreter hooks/event handlers. */
 181   clear_interpreter_hooks ();
 182
 183   if (interp->procs->resume_proc != NULL
 184       && (!interp->procs->resume_proc (interp->data)))
 185     {
 186       if (old_interp == NULL || !interp_set (old_interp))
 187         internal_error (__FILE__, __LINE__,
 188                         "Failed to initialize new interp \"%s\" %s",
 189                         interp->name, "and could not restore old interp!\n");
 190       return 0;
 191     }
 192
 193   /* Finally, put up the new prompt to show that we are indeed here.
 194      Also, display_gdb_prompt for the console does some readline magic
 195      which is needed for the console interpreter, at least... */
 196
 197   if (!first_time)
 198     {
 199       if (!interp_quiet_p (interp))
 200         {
 201           sprintf (buffer, "Switching to interpreter \"%.24s\".\n",
 202                    interp->name);
 203           ui_out_text (uiout, buffer);
 204         }
 205       display_gdb_prompt (NULL);
 206     }
 207
 208   return 1;
 209 }
 210
 211 /* interp_lookup - Looks up the interpreter for NAME.  If no such
 212    interpreter exists, return NULL, otherwise return a pointer to the
 213    interpreter.  */
 214 struct interp *
 215 interp_lookup (const char *name)
 216 {
 217   struct interp *interp;
 218
 219   if (name == NULL || strlen (name) == 0)
 220     return NULL;
 221
 222   for (interp = interp_list; interp != NULL; interp = interp->next)
 223     {
 224       if (strcmp (interp->name, name) == 0)
 225         return interp;
 226     }
 227
 228   return NULL;
 229 }
 230
 231 /* Returns the current interpreter. */
 232
 233 struct ui_out *
 234 interp_ui_out (struct interp *interp)
 235 {
 236   if (interp != NULL)
 237     return interp->interpreter_out;
 238
 239   return current_interpreter->interpreter_out;
 240 }
 241
 242 /* Returns true if the current interp is the passed in name. */
 243 int
 244 current_interp_named_p (const char *interp_name)
 245 {
 246   if (current_interpreter)
 247     return (strcmp (current_interpreter->name, interp_name) == 0);
 248
 249   return 0;
 250 }
 251
 252 /* This is called in display_gdb_prompt.  If the proc returns a zero
 253    value, display_gdb_prompt will return without displaying the
 254    prompt.  */
 255 int
 256 current_interp_display_prompt_p (void)
 257 {
 258   if (current_interpreter == NULL
 259       || current_interpreter->procs->prompt_proc_p == NULL)
 260     return 0;
 261   else
 262     return current_interpreter->procs->prompt_proc_p (current_interpreter->
 263                                                       data);
 264 }
 265
 266 /* Run the current command interpreter's main loop.  */
 267 void
 268 current_interp_command_loop (void)
 269 {
 270   /* Somewhat messy.  For the moment prop up all the old ways of
 271      selecting the command loop.  `deprecated_command_loop_hook'
 272      should be deprecated.  */
 273   if (deprecated_command_loop_hook != NULL)
 274     deprecated_command_loop_hook ();
 275   else if (current_interpreter != NULL
 276            && current_interpreter->procs->command_loop_proc != NULL)
 277     current_interpreter->procs->command_loop_proc (current_interpreter->data);
 278   else if (event_loop_p)
 279     cli_command_loop ();
 280   else
 281     command_loop ();
 282 }
 283
 284 int
 285 interp_quiet_p (struct interp *interp)
 286 {
 287   if (interp != NULL)
 288     return interp->quiet_p;
 289   else
 290     return current_interpreter->quiet_p;
 291 }
 292
 293 static int
 294 interp_set_quiet (struct interp *interp, int quiet)
 295 {
 296   int old_val = interp->quiet_p;
 297   interp->quiet_p = quiet;
 298   return old_val;
 299 }
 300
 301 /* interp_exec - This executes COMMAND_STR in the current
 302    interpreter. */
 303 int
 304 interp_exec_p (struct interp *interp)
 305 {
 306   return interp->procs->exec_proc != NULL;
 307 }
 308
 309 int
 310 interp_exec (struct interp *interp, const char *command_str)
 311 {
 312   if (interp->procs->exec_proc != NULL)
 313     {
 314       return interp->procs->exec_proc (interp->data, command_str);
 315     }
 316   return 0;
 317 }
 318
 319 /* A convenience routine that nulls out all the
 320    common command hooks.  Use it when removing your interpreter in its
 321    suspend proc. */
 322 void
 323 clear_interpreter_hooks (void)
 324 {
 325   deprecated_init_ui_hook = 0;
 326   deprecated_print_frame_info_listing_hook = 0;
 327   /*print_frame_more_info_hook = 0; */
 328   deprecated_query_hook = 0;
 329   deprecated_warning_hook = 0;
 330   deprecated_create_breakpoint_hook = 0;
 331   deprecated_delete_breakpoint_hook = 0;
 332   deprecated_modify_breakpoint_hook = 0;
 333   deprecated_interactive_hook = 0;
 334   deprecated_registers_changed_hook = 0;
 335   deprecated_readline_begin_hook = 0;
 336   deprecated_readline_hook = 0;
 337   deprecated_readline_end_hook = 0;
 338   deprecated_register_changed_hook = 0;
 339   deprecated_memory_changed_hook = 0;
 340   deprecated_context_hook = 0;
 341   deprecated_target_wait_hook = 0;
 342   deprecated_call_command_hook = 0;
 343   deprecated_error_hook = 0;
 344   deprecated_error_begin_hook = 0;
 345   deprecated_command_loop_hook = 0;
 346   clear_gdb_event_hooks ();
 347 }
 348
 349 /* This is a lazy init routine, called the first time
 350    the interpreter module is used.  I put it here just in case, but I haven't
 351    thought of a use for it yet.  I will probably bag it soon, since I don't
 352    think it will be necessary. */
 353 static void
 354 initialize_interps (void)
 355 {
 356   interpreter_initialized = 1;
 357   /* Don't know if anything needs to be done here... */
 358 }
 359
 360 static void
 361 interpreter_exec_cmd (char *args, int from_tty)
 362 {
 363   struct interp *old_interp, *interp_to_use;
 364   char **prules = NULL;
 365   char **trule = NULL;
 366   unsigned int nrules;
 367   unsigned int i;
 368   int old_quiet, use_quiet;
 369
 370   prules = buildargv (args);
 371   if (prules == NULL)
 372     {
 373       error ("unable to parse arguments");
 374     }
 375
 376   nrules = 0;
 377   if (prules != NULL)
 378     {
 379       for (trule = prules; *trule != NULL; trule++)
 380         {
 381           nrules++;
 382         }
 383     }
 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))
 399     error ("Could not switch to interpreter \"%s\".", prules[0]);
 400
 401   for (i = 1; i < nrules; i++)
 402     {
 403       if (!interp_exec (interp_to_use, prules[i]))
 404         {
 405           interp_set (old_interp);
 406           interp_set_quiet (interp_to_use, old_quiet);
 407           error ("error in command: \"%s\".", prules[i]);
 408           break;
 409         }
 410     }
 411
 412   interp_set (old_interp);
 413   interp_set_quiet (interp_to_use, use_quiet);
 414   interp_set_quiet (old_interp, old_quiet);
 415 }
 416
 417 /* List the possible interpreters which could complete the given text. */
 418 static char **
 419 interpreter_completer (char *text, char *word)
 420 {
 421   int alloced = 0;
 422   int textlen;
 423   int num_matches;
 424   char **matches;
 425   struct interp *interp;
 426
 427   /* We expect only a very limited number of interpreters, so just
 428      allocate room for all of them. */
 429   for (interp = interp_list; interp != NULL; interp = interp->next)
 430     ++alloced;
 431   matches = (char **) xmalloc (alloced * 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   else if (num_matches < alloced)
 465     {
 466       matches = (char **) xrealloc ((char *) matches, ((num_matches + 1)
 467                                                        * sizeof (char *)));
 468       matches[num_matches] = NULL;
 469     }
 470
 471   return matches;
 472 }
 473
 474 /* This just adds the "interpreter-exec" command.  */
 475 void
 476 _initialize_interpreter (void)
 477 {
 478   struct cmd_list_element *c;
 479
 480   c = add_cmd ("interpreter-exec", class_support,
 481                interpreter_exec_cmd,
 482                "Execute a command in an interpreter.  It takes two arguments:\n\
 483 The first argument is the name of the interpreter to use.\n\
 484 The second argument is the command to execute.\n", &cmdlist);
 485   set_cmd_completer (c, interpreter_completer);
 486 }