libguile/debug.c

   1 /* Debugging extensions for Guile
   2  * Copyright (C) 1995,1996,1997,1998,1999,2000,2001, 2002, 2003, 2006, 2008, 2009 Free Software Foundation
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2.1 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the Free Software
  16  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  17  */
  18
  19
  20 #ifdef HAVE_CONFIG_H
  21 # include <config.h>
  22 #endif
  23
  24 #include "libguile/_scm.h"
  25 #include "libguile/async.h"
  26 #include "libguile/eval.h"
  27 #include "libguile/list.h"
  28 #include "libguile/stackchk.h"
  29 #include "libguile/throw.h"
  30 #include "libguile/macros.h"
  31 #include "libguile/smob.h"
  32 #include "libguile/procprop.h"
  33 #include "libguile/srcprop.h"
  34 #include "libguile/alist.h"
  35 #include "libguile/continuations.h"
  36 #include "libguile/strports.h"
  37 #include "libguile/read.h"
  38 #include "libguile/feature.h"
  39 #include "libguile/dynwind.h"
  40 #include "libguile/modules.h"
  41 #include "libguile/ports.h"
  42 #include "libguile/root.h"
  43 #include "libguile/fluids.h"
  44 #include "libguile/objects.h"
  45
  46 #include "libguile/validate.h"
  47 #include "libguile/debug.h"
  48
  49 #include "libguile/private-options.h"
  50 \f
  51
  52
  53 /* {Run time control of the debugging evaluator}
  54  */
  55
  56 SCM_DEFINE (scm_debug_options, "debug-options-interface", 0, 1, 0,
  57             (SCM setting),
  58             "Option interface for the debug options. Instead of using\n"
  59             "this procedure directly, use the procedures @code{debug-enable},\n"
  60             "@code{debug-disable}, @code{debug-set!} and @code{debug-options}.")
  61 #define FUNC_NAME s_scm_debug_options
  62 {
  63   SCM ans;
  64
  65   scm_dynwind_begin (0);
  66   scm_dynwind_critical_section (SCM_BOOL_F);
  67
  68   ans = scm_options (setting, scm_debug_opts, FUNC_NAME);
  69   if (!(1 <= SCM_N_FRAMES && SCM_N_FRAMES <= SCM_MAX_FRAME_SIZE))
  70     {
  71       scm_options (ans, scm_debug_opts, FUNC_NAME);
  72       SCM_OUT_OF_RANGE (1, setting);
  73     }
  74   SCM_RESET_DEBUG_MODE;
  75   scm_stack_checking_enabled_p = SCM_STACK_CHECKING_P;
  76   scm_debug_eframe_size = 2 * SCM_N_FRAMES;
  77
  78   scm_dynwind_end ();
  79   return ans;
  80 }
  81 #undef FUNC_NAME
  82
  83
  84 static void
  85 with_traps_before (void *data)
  86 {
  87   int *trap_flag = data;
  88   *trap_flag = SCM_TRAPS_P;
  89   SCM_TRAPS_P = 1;
  90 }
  91
  92 static void
  93 with_traps_after (void *data)
  94 {
  95   int *trap_flag = data;
  96   SCM_TRAPS_P = *trap_flag;
  97 }
  98
  99 static SCM
 100 with_traps_inner (void *data)
 101 {
 102   SCM thunk = SCM_PACK ((scm_t_bits) data);
 103   return scm_call_0 (thunk);
 104 }
 105
 106 SCM_DEFINE (scm_with_traps, "with-traps", 1, 0, 0,
 107             (SCM thunk),
 108             "Call @var{thunk} with traps enabled.")
 109 #define FUNC_NAME s_scm_with_traps
 110 {
 111   int trap_flag;
 112   SCM_VALIDATE_THUNK (1, thunk);
 113   return scm_internal_dynamic_wind (with_traps_before,
 114                                     with_traps_inner,
 115                                     with_traps_after,
 116                                     (void *) SCM_UNPACK (thunk),
 117                                     &trap_flag);
 118 }
 119 #undef FUNC_NAME
 120
 121 \f
 122 SCM_SYMBOL (scm_sym_procname, "procname");
 123 SCM_SYMBOL (scm_sym_dots, "...");
 124 SCM_SYMBOL (scm_sym_source, "source");
 125
 126 /* {Memoized Source}
 127  */
 128
 129 scm_t_bits scm_tc16_memoized;
 130
 131 static int
 132 memoized_print (SCM obj, SCM port, scm_print_state *pstate)
 133 {
 134   int writingp = SCM_WRITINGP (pstate);
 135   scm_puts ("#<memoized ", port);
 136   SCM_SET_WRITINGP (pstate, 1);
 137   scm_iprin1 (SCM_MEMOIZED_EXP (obj), port, pstate);
 138   SCM_SET_WRITINGP (pstate, writingp);
 139   scm_putc ('>', port);
 140   return 1;
 141 }
 142
 143 SCM_DEFINE (scm_memoized_p, "memoized?", 1, 0, 0,
 144             (SCM obj),
 145             "Return @code{#t} if @var{obj} is memoized.")
 146 #define FUNC_NAME s_scm_memoized_p
 147 {
 148   return scm_from_bool(SCM_MEMOIZEDP (obj));
 149 }
 150 #undef FUNC_NAME
 151
 152 SCM
 153 scm_make_memoized (SCM exp, SCM env)
 154 {
 155   /* *fixme* Check that env is a valid environment. */
 156   SCM_RETURN_NEWSMOB (scm_tc16_memoized, SCM_UNPACK (scm_cons (exp, env)));
 157 }
 158
 159 #ifdef GUILE_DEBUG
 160 /*
 161  * Some primitives for construction of memoized code
 162  *
 163  * - procedure: memcons CAR CDR [ENV]
 164  *
 165  *     Construct a pair, encapsulated in a memoized object.
 166  *
 167  *     The CAR and CDR can be either normal or memoized.  If ENV isn't
 168  *     specified, the top-level environment of the current module will
 169  *     be assumed.  All environments must match.
 170  *
 171  * - procedure: make-iloc FRAME BINDING CDRP
 172  *
 173  *     Return an iloc referring to frame no. FRAME, binding
 174  *     no. BINDING.  If CDRP is non-#f, the iloc is referring to a
 175  *     frame consisting of a single pair, with the value stored in the
 176  *     CDR.
 177  *
 178  * - procedure: iloc? OBJECT
 179  *
 180  *     Return #t if OBJECT is an iloc.
 181  *
 182  * - procedure: mem->proc MEMOIZED
 183  *
 184  *     Construct a closure from the memoized lambda expression MEMOIZED
 185  *
 186  *     WARNING! The code is not copied!
 187  *
 188  * - procedure: proc->mem CLOSURE
 189  *
 190  *     Turn the closure CLOSURE into a memoized object.
 191  *
 192  *     WARNING! The code is not copied!
 193  *
 194  * - constant: SCM_IM_AND
 195  * - constant: SCM_IM_BEGIN
 196  * - constant: SCM_IM_CASE
 197  * - constant: SCM_IM_COND
 198  * - constant: SCM_IM_DO
 199  * - constant: SCM_IM_IF
 200  * - constant: SCM_IM_LAMBDA
 201  * - constant: SCM_IM_LET
 202  * - constant: SCM_IM_LETSTAR
 203  * - constant: SCM_IM_LETREC
 204  * - constant: SCM_IM_OR
 205  * - constant: SCM_IM_QUOTE
 206  * - constant: SCM_IM_SET
 207  * - constant: SCM_IM_DEFINE
 208  * - constant: SCM_IM_APPLY
 209  * - constant: SCM_IM_CONT
 210  * - constant: SCM_IM_DISPATCH
 211  */
 212
 213 #include "libguile/variable.h"
 214 #include "libguile/procs.h"
 215
 216 SCM_DEFINE (scm_memcons, "memcons", 2, 1, 0,
 217             (SCM car, SCM cdr, SCM env),
 218             "Return a new memoized cons cell with @var{car} and @var{cdr}\n"
 219             "as members and @var{env} as the environment.")
 220 #define FUNC_NAME s_scm_memcons
 221 {
 222   if (SCM_MEMOIZEDP (car))
 223     {
 224       /*fixme* environments may be two different but equal top-level envs */
 225       if (!SCM_UNBNDP (env) && SCM_MEMOIZED_ENV (car) != env)
 226         SCM_MISC_ERROR ("environment mismatch arg1 <-> arg3",
 227                         scm_list_2 (car, env));
 228       else
 229         env = SCM_MEMOIZED_ENV (car);
 230       car = SCM_MEMOIZED_EXP (car);
 231     }
 232   if (SCM_MEMOIZEDP (cdr))
 233     {
 234       if (!SCM_UNBNDP (env) && SCM_MEMOIZED_ENV (cdr) != env)
 235         SCM_MISC_ERROR ("environment mismatch arg2 <-> arg3",
 236                         scm_list_2 (cdr, env));
 237       else
 238         env = SCM_MEMOIZED_ENV (cdr);
 239       cdr = SCM_MEMOIZED_EXP (cdr);
 240     }
 241   if (SCM_UNBNDP (env))
 242     env = scm_top_level_env (SCM_TOP_LEVEL_LOOKUP_CLOSURE);
 243   else
 244     SCM_VALIDATE_NULLORCONS (3, env);
 245   return scm_make_memoized (scm_cons (car, cdr), env);
 246 }
 247 #undef FUNC_NAME
 248
 249 SCM_DEFINE (scm_mem_to_proc, "mem->proc", 1, 0, 0,
 250             (SCM obj),
 251             "Convert a memoized object (which must represent a body)\n"
 252             "to a procedure.")
 253 #define FUNC_NAME s_scm_mem_to_proc
 254 {
 255   SCM env;
 256   SCM_VALIDATE_MEMOIZED (1, obj);
 257   env = SCM_MEMOIZED_ENV (obj);
 258   obj = SCM_MEMOIZED_EXP (obj);
 259   return scm_closure (obj, env);
 260 }
 261 #undef FUNC_NAME
 262
 263 SCM_DEFINE (scm_proc_to_mem, "proc->mem", 1, 0, 0,
 264             (SCM obj),
 265             "Convert a procedure to a memoized object.")
 266 #define FUNC_NAME s_scm_proc_to_mem
 267 {
 268   SCM_VALIDATE_CLOSURE (1, obj);
 269   return scm_make_memoized (SCM_CODE (obj), SCM_ENV (obj));
 270 }
 271 #undef FUNC_NAME
 272
 273 #endif /* GUILE_DEBUG */
 274
 275 SCM_DEFINE (scm_i_unmemoize_expr, "unmemoize-expr", 1, 0, 0,
 276             (SCM m),
 277             "Unmemoize the memoized expression @var{m},")
 278 #define FUNC_NAME s_scm_i_unmemoize_expr
 279 {
 280   SCM_VALIDATE_MEMOIZED (1, m);
 281   return scm_i_unmemocopy_expr (SCM_MEMOIZED_EXP (m), SCM_MEMOIZED_ENV (m));
 282 }
 283 #undef FUNC_NAME
 284
 285 SCM_DEFINE (scm_memoized_environment, "memoized-environment", 1, 0, 0,
 286             (SCM m),
 287             "Return the environment of the memoized expression @var{m}.")
 288 #define FUNC_NAME s_scm_memoized_environment
 289 {
 290   SCM_VALIDATE_MEMOIZED (1, m);
 291   return SCM_MEMOIZED_ENV (m);
 292 }
 293 #undef FUNC_NAME
 294
 295 SCM_DEFINE (scm_procedure_name, "procedure-name", 1, 0, 0,
 296             (SCM proc),
 297             "Return the name of the procedure @var{proc}")
 298 #define FUNC_NAME s_scm_procedure_name
 299 {
 300   SCM_VALIDATE_PROC (1, proc);
 301   switch (SCM_TYP7 (proc)) {
 302   case scm_tcs_subrs:
 303     return SCM_SNAME (proc);
 304   default:
 305     {
 306       SCM name = scm_procedure_property (proc, scm_sym_name);
 307 #if 0
 308       /* Source property scm_sym_procname not implemented yet... */
 309       SCM name = scm_source_property (SCM_CAR (SCM_CLOSURE_BODY (proc)), scm_sym_procname);
 310       if (scm_is_false (name))
 311         name = scm_procedure_property (proc, scm_sym_name);
 312 #endif
 313       if (scm_is_false (name) && SCM_CLOSUREP (proc))
 314         name = scm_reverse_lookup (SCM_ENV (proc), proc);
 315       return name;
 316     }
 317   }
 318 }
 319 #undef FUNC_NAME
 320
 321 SCM_DEFINE (scm_procedure_source, "procedure-source", 1, 0, 0,
 322             (SCM proc),
 323             "Return the source of the procedure @var{proc}.")
 324 #define FUNC_NAME s_scm_procedure_source
 325 {
 326   SCM_VALIDATE_NIM (1, proc);
 327  again:
 328   switch (SCM_TYP7 (proc)) {
 329   case scm_tcs_closures:
 330     {
 331       const SCM formals = SCM_CLOSURE_FORMALS (proc);
 332       const SCM body = SCM_CLOSURE_BODY (proc);
 333       const SCM src = scm_source_property (body, scm_sym_copy);
 334
 335       if (scm_is_true (src))
 336         {
 337           return scm_cons2 (scm_sym_lambda, formals, src);
 338         }
 339       else
 340         {
 341           const SCM env = SCM_EXTEND_ENV (formals, SCM_EOL, SCM_ENV (proc));
 342           return scm_cons2 (scm_sym_lambda,
 343                             scm_i_finite_list_copy (formals),
 344                             scm_i_unmemocopy_body (body, env));
 345         }
 346     }
 347   case scm_tcs_struct:
 348     if (!SCM_I_OPERATORP (proc))
 349       break;
 350     goto procprop;
 351   case scm_tc7_smob:
 352     if (!SCM_SMOB_DESCRIPTOR (proc).apply)
 353       break;
 354   case scm_tcs_subrs:
 355   procprop:
 356     /* It would indeed be a nice thing if we supplied source even for
 357        built in procedures! */
 358     return scm_procedure_property (proc, scm_sym_source);
 359   case scm_tc7_pws:
 360     {
 361       SCM src = scm_procedure_property (proc, scm_sym_source);
 362       if (scm_is_true (src))
 363         return src;
 364       proc = SCM_PROCEDURE (proc);
 365       goto again;
 366     }
 367   default:
 368     ;
 369   }
 370   SCM_WRONG_TYPE_ARG (1, proc);
 371   return SCM_BOOL_F; /* not reached */
 372 }
 373 #undef FUNC_NAME
 374
 375 SCM_DEFINE (scm_procedure_environment, "procedure-environment", 1, 0, 0,
 376             (SCM proc),
 377             "Return the environment of the procedure @var{proc}.")
 378 #define FUNC_NAME s_scm_procedure_environment
 379 {
 380   SCM_VALIDATE_NIM (1, proc);
 381   switch (SCM_TYP7 (proc)) {
 382   case scm_tcs_closures:
 383     return SCM_ENV (proc);
 384   case scm_tcs_subrs:
 385     return SCM_EOL;
 386   default:
 387     SCM_WRONG_TYPE_ARG (1, proc);
 388     /* not reached */
 389   }
 390 }
 391 #undef FUNC_NAME
 392
 393 \f
 394
 395 /* Eval in a local environment.  We would like to have the ability to
 396  * evaluate in a specified local environment, but due to the
 397  * memoization this isn't normally possible.  We solve it by copying
 398  * the code before evaluating.  One solution would be to have eval.c
 399  * generate yet another evaluator.  They are not very big actually.
 400  */
 401 SCM_DEFINE (scm_local_eval, "local-eval", 1, 1, 0,
 402             (SCM exp, SCM env),
 403             "Evaluate @var{exp} in its environment.  If @var{env} is supplied,\n"
 404             "it is the environment in which to evaluate @var{exp}.  Otherwise,\n"
 405             "@var{exp} must be a memoized code object (in which case, its environment\n"
 406             "is implicit).")
 407 #define FUNC_NAME s_scm_local_eval
 408 {
 409   if (SCM_UNBNDP (env))
 410   {
 411     SCM_VALIDATE_MEMOIZED (1, exp);
 412     return scm_i_eval_x (SCM_MEMOIZED_EXP (exp), SCM_MEMOIZED_ENV (exp));
 413   }
 414   return scm_i_eval (exp, env);
 415 }
 416 #undef FUNC_NAME
 417
 418 #if 0
 419 SCM_REGISTER_PROC (s_reverse_lookup, "reverse-lookup", 2, 0, 0, scm_reverse_lookup);
 420 #endif
 421
 422 SCM
 423 scm_reverse_lookup (SCM env, SCM data)
 424 {
 425   while (scm_is_pair (env) && scm_is_pair (SCM_CAR (env)))
 426     {
 427       SCM names = SCM_CAAR (env);
 428       SCM values = SCM_CDAR (env);
 429       while (scm_is_pair (names))
 430         {
 431           if (scm_is_eq (SCM_CAR (values), data))
 432             return SCM_CAR (names);
 433           names = SCM_CDR (names);
 434           values = SCM_CDR (values);
 435         }
 436       if (!scm_is_null (names) && scm_is_eq (values, data))
 437         return names;
 438       env = SCM_CDR (env);
 439     }
 440   return SCM_BOOL_F;
 441 }
 442
 443 SCM
 444 scm_start_stack (SCM id, SCM exp, SCM env)
 445 {
 446   SCM answer;
 447   scm_t_debug_frame vframe;
 448   scm_t_debug_info vframe_vect_body;
 449   vframe.prev = scm_i_last_debug_frame ();
 450   vframe.status = SCM_VOIDFRAME;
 451   vframe.vect = &vframe_vect_body;
 452   vframe.vect[0].id = id;
 453   scm_i_set_last_debug_frame (&vframe);
 454   answer = scm_i_eval (exp, env);
 455   scm_i_set_last_debug_frame (vframe.prev);
 456   return answer;
 457 }
 458
 459 SCM_SYNTAX(s_start_stack, "start-stack", scm_makacro, scm_m_start_stack);
 460
 461 static SCM
 462 scm_m_start_stack (SCM exp, SCM env)
 463 #define FUNC_NAME s_start_stack
 464 {
 465   exp = SCM_CDR (exp);
 466   if (!scm_is_pair (exp)
 467       || !scm_is_pair (SCM_CDR (exp))
 468       || !scm_is_null (SCM_CDDR (exp)))
 469     SCM_WRONG_NUM_ARGS ();
 470   return scm_start_stack (scm_eval_car (exp, env), SCM_CADR (exp), env);
 471 }
 472 #undef FUNC_NAME
 473
 474
 475 /* {Debug Objects}
 476  *
 477  * The debugging evaluator throws these on frame traps.
 478  */
 479
 480 scm_t_bits scm_tc16_debugobj;
 481
 482 static int
 483 debugobj_print (SCM obj, SCM port, scm_print_state *pstate SCM_UNUSED)
 484 {
 485   scm_puts ("#<debug-object ", port);
 486   scm_intprint ((long) SCM_DEBUGOBJ_FRAME (obj), 16, port);
 487   scm_putc ('>', port);
 488   return 1;
 489 }
 490
 491 SCM_DEFINE (scm_debug_object_p, "debug-object?", 1, 0, 0,
 492             (SCM obj),
 493             "Return @code{#t} if @var{obj} is a debug object.")
 494 #define FUNC_NAME s_scm_debug_object_p
 495 {
 496   return scm_from_bool(SCM_DEBUGOBJP (obj));
 497 }
 498 #undef FUNC_NAME
 499
 500
 501 SCM
 502 scm_make_debugobj (scm_t_debug_frame *frame)
 503 {
 504   return scm_cell (scm_tc16_debugobj, (scm_t_bits) frame);
 505 }
 506
 507 \f
 508
 509 /* Undocumented debugging procedure */
 510 #ifdef GUILE_DEBUG
 511 SCM_DEFINE (scm_debug_hang, "debug-hang", 0, 1, 0,
 512             (SCM obj),
 513             "Go into an endless loop, which can be only terminated with\n"
 514             "a debugger.")
 515 #define FUNC_NAME s_scm_debug_hang
 516 {
 517   int go = 0;
 518   while (!go) ;
 519   return SCM_UNSPECIFIED;
 520 }
 521 #undef FUNC_NAME
 522 #endif
 523
 524 \f
 525
 526 void
 527 scm_init_debug ()
 528 {
 529   scm_init_opts (scm_debug_options, scm_debug_opts);
 530
 531   scm_tc16_memoized = scm_make_smob_type ("memoized", 0);
 532   scm_set_smob_mark (scm_tc16_memoized, scm_markcdr);
 533   scm_set_smob_print (scm_tc16_memoized, memoized_print);
 534
 535   scm_tc16_debugobj = scm_make_smob_type ("debug-object", 0);
 536   scm_set_smob_print (scm_tc16_debugobj, debugobj_print);
 537
 538 #ifdef GUILE_DEBUG
 539   scm_c_define ("SCM_IM_AND", SCM_IM_AND);
 540   scm_c_define ("SCM_IM_BEGIN", SCM_IM_BEGIN);
 541   scm_c_define ("SCM_IM_CASE", SCM_IM_CASE);
 542   scm_c_define ("SCM_IM_COND", SCM_IM_COND);
 543   scm_c_define ("SCM_IM_DO", SCM_IM_DO);
 544   scm_c_define ("SCM_IM_IF", SCM_IM_IF);
 545   scm_c_define ("SCM_IM_LAMBDA", SCM_IM_LAMBDA);
 546   scm_c_define ("SCM_IM_LET", SCM_IM_LET);
 547   scm_c_define ("SCM_IM_LETSTAR", SCM_IM_LETSTAR);
 548   scm_c_define ("SCM_IM_LETREC", SCM_IM_LETREC);
 549   scm_c_define ("SCM_IM_OR", SCM_IM_OR);
 550   scm_c_define ("SCM_IM_QUOTE", SCM_IM_QUOTE);
 551   scm_c_define ("SCM_IM_SET_X", SCM_IM_SET_X);
 552   scm_c_define ("SCM_IM_DEFINE", SCM_IM_DEFINE);
 553   scm_c_define ("SCM_IM_APPLY", SCM_IM_APPLY);
 554   scm_c_define ("SCM_IM_CONT", SCM_IM_CONT);
 555   scm_c_define ("SCM_IM_DISPATCH", SCM_IM_DISPATCH);
 556 #endif
 557   scm_add_feature ("debug-extensions");
 558
 559 #include "libguile/debug.x"
 560 }
 561
 562 /*
 563   Local Variables:
 564   c-file-style: "gnu"
 565   End:
 566 */