libguile/backtrace.c

   1 /* Printing of backtraces and error messages
   2  * Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2009,
   3  *   2010, 2011, 2014 Free Software Foundation
   4  *
   5  * This library is free software; you can redistribute it and/or
   6  * modify it under the terms of the GNU Lesser General Public License
   7  * as published by the Free Software Foundation; either version 3 of
   8  * the License, or (at your option) any later version.
   9  *
  10  * This library is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * Lesser General Public License for more details.
  14  *
  15  * You should have received a copy of the GNU Lesser General Public
  16  * License along with this library; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
  18  * 02110-1301 USA
  19  */
  20
  21 #ifdef HAVE_CONFIG_H
  22 #  include <config.h>
  23 #endif
  24
  25 #include <stdio.h>
  26 #include <ctype.h>
  27
  28 #include "libguile/_scm.h"
  29
  30 #include <unistd.h>
  31 #ifdef HAVE_IO_H
  32 #include <io.h>
  33 #endif
  34
  35 #include "libguile/deprecation.h"
  36 #include "libguile/stacks.h"
  37 #include "libguile/srcprop.h"
  38 #include "libguile/struct.h"
  39 #include "libguile/strports.h"
  40 #include "libguile/throw.h"
  41 #include "libguile/fluids.h"
  42 #include "libguile/ports.h"
  43 #include "libguile/strings.h"
  44 #include "libguile/dynwind.h"
  45 #include "libguile/frames.h"
  46
  47 #include "libguile/validate.h"
  48 #include "libguile/backtrace.h"
  49 #include "libguile/filesys.h"
  50 #include "libguile/private-options.h"
  51
  52 /* {Error reporting and backtraces}
  53  *
  54  * Note that these functions shouldn't generate errors themselves.
  55  */
  56
  57 static SCM
  58 boot_print_exception (SCM port, SCM frame, SCM key, SCM args)
  59 #define FUNC_NAME "boot-print-exception"
  60 {
  61   scm_puts_unlocked ("Throw to key ", port);
  62   scm_write (key, port);
  63   scm_puts_unlocked (" with args ", port);
  64   scm_write (args, port);
  65   return SCM_UNSPECIFIED;
  66 }
  67 #undef FUNC_NAME
  68
  69 static SCM print_exception_var;
  70
  71 static void
  72 init_print_exception_var (void)
  73 {
  74   print_exception_var
  75     = scm_module_variable (scm_the_root_module (),
  76                            scm_from_latin1_symbol ("print-exception"));
  77 }
  78
  79 SCM
  80 scm_print_exception (SCM port, SCM frame, SCM key, SCM args)
  81 #define FUNC_NAME "print-exception"
  82 {
  83   static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
  84   scm_i_pthread_once (&once, init_print_exception_var);
  85
  86   SCM_VALIDATE_OPOUTPORT (1, port);
  87   if (scm_is_true (frame))
  88     SCM_VALIDATE_FRAME (2, frame);
  89   SCM_VALIDATE_SYMBOL (3, key);
  90   SCM_VALIDATE_LIST (4, args);
  91
  92   return scm_call_4 (scm_variable_ref (print_exception_var),
  93                      port, frame, key, args);
  94 }
  95 #undef FUNC_NAME
  96
  97
  98 \f
  99
 100 /* Print parameters for error messages. */
 101
 102 #define DISPLAY_ERROR_MESSAGE_MAX_LEVEL   7
 103 #define DISPLAY_ERROR_MESSAGE_MAX_LENGTH 10
 104
 105 /* Print parameters for failing expressions in error messages.
 106  * (See also `print_params' below for backtrace print parameters.)
 107  */
 108
 109 #define DISPLAY_EXPRESSION_MAX_LEVEL      2
 110 #define DISPLAY_EXPRESSION_MAX_LENGTH     3
 111
 112 #undef SCM_ASSERT
 113 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 114         if (!(_cond)) \
 115           return SCM_BOOL_F;
 116
 117
 118 void
 119 scm_display_error_message (SCM message, SCM args, SCM port)
 120 {
 121   scm_print_exception (port, SCM_BOOL_F, scm_misc_error_key,
 122                        scm_list_3 (SCM_BOOL_F, message, args));
 123 }
 124
 125
 126 /* The function scm_i_display_error prints out a detailed error message.  This
 127  * function will be called directly within libguile to signal error messages.
 128  * No parameter checks will be performed by scm_i_display_error.  Thus, User
 129  * code should rather use the function scm_display_error.
 130  */
 131 void
 132 scm_i_display_error (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest)
 133 {
 134   scm_print_exception (port, frame, scm_misc_error_key,
 135                        scm_list_3 (subr, message, args));
 136 }
 137
 138
 139 SCM_DEFINE (scm_display_error, "display-error", 6, 0, 0,
 140             (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest),
 141             "Display an error message to the output port @var{port}.\n"
 142             "@var{frame} is the frame in which the error occurred, @var{subr} is\n"
 143             "the name of the procedure in which the error occurred and\n"
 144             "@var{message} is the actual error message, which may contain\n"
 145             "formatting instructions. These will format the arguments in\n"
 146             "the list @var{args} accordingly.  @var{rest} is currently\n"
 147             "ignored.")
 148 #define FUNC_NAME s_scm_display_error
 149 {
 150   SCM_VALIDATE_OUTPUT_PORT (2, port);
 151
 152 #if SCM_ENABLE_DEPRECATED
 153   if (SCM_STACKP (frame))
 154     {
 155       scm_c_issue_deprecation_warning
 156         ("Passing a stack as the first argument to `scm_display_error' is "
 157          "deprecated.  Pass a frame instead.");
 158       if (SCM_STACK_LENGTH (frame))
 159         frame = scm_stack_ref (frame, SCM_INUM0);
 160       else
 161         frame = SCM_BOOL_F;
 162     }
 163 #endif
 164
 165   scm_i_display_error (frame, port, subr, message, args, rest);
 166
 167   return SCM_UNSPECIFIED;
 168 }
 169 #undef FUNC_NAME
 170
 171
 172 typedef struct {
 173   int level;
 174   int length;
 175 } print_params_t;
 176
 177 static int n_print_params = 9;
 178 static print_params_t default_print_params[] = {
 179   { 4, 9 }, { 4, 3 },
 180   { 3, 4 }, { 3, 3 },
 181   { 2, 4 }, { 2, 3 },
 182   { 1, 4 }, { 1, 3 }, { 1, 2 }
 183 };
 184 static print_params_t *print_params = default_print_params;
 185
 186 #ifdef GUILE_DEBUG
 187 SCM_DEFINE (scm_set_print_params_x, "set-print-params!", 1, 0, 0,
 188            (SCM params),
 189             "Set the print parameters to the values from @var{params}.\n"
 190             "@var{params} must be a list of two-element lists which must\n"
 191             "hold two integer values.")
 192 #define FUNC_NAME s_scm_set_print_params_x
 193 {
 194   int i;
 195   int n;
 196   SCM ls;
 197   print_params_t *new_params;
 198
 199   SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, params, n);
 200   for (ls = params; !SCM_NULL_OR_NIL_P (ls); ls = SCM_CDR (ls))
 201     SCM_ASSERT (scm_ilength (SCM_CAR (params)) == 2
 202                 && scm_is_unsigned_integer (SCM_CAAR (ls), 0, INT_MAX)
 203                 && scm_is_unsigned_integer (SCM_CADAR (ls), 0, INT_MAX),
 204                 params,
 205                 SCM_ARG2,
 206                 s_scm_set_print_params_x);
 207   new_params = scm_malloc (n * sizeof (print_params_t));
 208   if (print_params != default_print_params)
 209     free (print_params);
 210   print_params = new_params;
 211   for (i = 0; i < n; ++i)
 212     {
 213       print_params[i].level = scm_to_int (SCM_CAAR (params));
 214       print_params[i].length = scm_to_int (SCM_CADAR (params));
 215       params = SCM_CDR (params);
 216     }
 217   n_print_params = n;
 218   return SCM_UNSPECIFIED;
 219 }
 220 #undef FUNC_NAME
 221 #endif
 222
 223 static void
 224 indent (int n, SCM port)
 225 {
 226   int i;
 227   for (i = 0; i < n; ++i)
 228     scm_putc_unlocked (' ', port);
 229 }
 230
 231 static void
 232 display_frame_expr (char *hdr, SCM exp, char *tlr, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 233 {
 234   int i = 0, n;
 235   scm_t_ptob_descriptor *ptob = SCM_PORT_DESCRIPTOR (sport);
 236   do
 237     {
 238       pstate->length = print_params[i].length;
 239       ptob->seek (sport, 0, SEEK_SET);
 240       if (scm_is_pair (exp))
 241         {
 242           pstate->level = print_params[i].level - 1;
 243           scm_iprlist (hdr, exp, tlr[0], sport, pstate);
 244           scm_puts_unlocked (&tlr[1], sport);
 245         }
 246       else
 247         {
 248           pstate->level = print_params[i].level;
 249           scm_iprin1 (exp, sport, pstate);
 250         }
 251       ptob->flush (sport);
 252       n = ptob->seek (sport, 0, SEEK_CUR);
 253       ++i;
 254     }
 255   while (indentation + n > SCM_BACKTRACE_WIDTH && i < n_print_params);
 256   ptob->truncate (sport, n);
 257
 258   scm_display (scm_strport_to_string (sport), port);
 259 }
 260
 261 static void
 262 display_application (SCM frame, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 263 {
 264   display_frame_expr ("[", scm_frame_call_representation (frame), "]",
 265                       indentation,
 266                       sport,
 267                       port,
 268                       pstate);
 269 }
 270
 271 SCM_DEFINE (scm_display_application, "display-application", 1, 2, 0,
 272            (SCM frame, SCM port, SCM indent),
 273             "Display a procedure application @var{frame} to the output port\n"
 274             "@var{port}. @var{indent} specifies the indentation of the\n"
 275             "output.")
 276 #define FUNC_NAME s_scm_display_application
 277 {
 278   SCM_VALIDATE_FRAME (1, frame);
 279   if (SCM_UNBNDP (port))
 280     port = scm_current_output_port ();
 281   else
 282     SCM_VALIDATE_OPOUTPORT (2, port);
 283   if (SCM_UNBNDP (indent))
 284     indent = SCM_INUM0;
 285
 286   /* Display an application. */
 287   {
 288     SCM sport, print_state;
 289     scm_print_state *pstate;
 290
 291     /* Create a string port used for adaptation of printing parameters. */
 292     sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 293                            SCM_OPN | SCM_WRTNG,
 294                            FUNC_NAME);
 295
 296     /* Create a print state for printing of frames. */
 297     print_state = scm_make_print_state ();
 298     pstate = SCM_PRINT_STATE (print_state);
 299     pstate->writingp = 1;
 300     pstate->fancyp = 1;
 301
 302     display_application (frame, scm_to_int (indent), sport, port, pstate);
 303     return SCM_BOOL_T;
 304   }
 305 }
 306 #undef FUNC_NAME
 307
 308 SCM_SYMBOL (sym_base, "base");
 309
 310 static void
 311 display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
 312 {
 313   SCM source = scm_frame_source (frame);
 314   *file = *line = SCM_BOOL_F;
 315   if (scm_is_pair (source)
 316       && scm_is_pair (scm_cdr (source))
 317       && scm_is_pair (scm_cddr (source))
 318       && !scm_is_pair (scm_cdddr (source)))
 319     {
 320       /* (addr . (filename . (line . column))), from vm compilation */
 321       *file = scm_cadr (source);
 322       *line = scm_caddr (source);
 323     }
 324 }
 325
 326 static void
 327 display_backtrace_file (frame, last_file, port, pstate)
 328      SCM frame;
 329      SCM *last_file;
 330      SCM port;
 331      scm_print_state *pstate;
 332 {
 333   SCM file, line;
 334
 335   display_backtrace_get_file_line (frame, &file, &line);
 336
 337   if (scm_is_true (scm_equal_p (file, *last_file)))
 338     return;
 339
 340   *last_file = file;
 341
 342   scm_puts_unlocked ("In ", port);
 343   if (scm_is_false (file))
 344     if (scm_is_false (line))
 345       scm_puts_unlocked ("unknown file", port);
 346     else
 347       scm_puts_unlocked ("current input", port);
 348   else
 349     {
 350       pstate->writingp = 0;
 351       scm_iprin1 (file, port, pstate);
 352       pstate->writingp = 1;
 353     }
 354   scm_puts_unlocked (":\n", port);
 355 }
 356
 357 static void
 358 display_backtrace_file_and_line (SCM frame, SCM port, scm_print_state *pstate)
 359 {
 360   SCM file, line;
 361
 362   display_backtrace_get_file_line (frame, &file, &line);
 363
 364   if (scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 365     {
 366       if (scm_is_false (file))
 367         {
 368           if (scm_is_false (line))
 369             scm_putc_unlocked ('?', port);
 370           else
 371             scm_puts_unlocked ("<stdin>", port);
 372         }
 373       else
 374         {
 375           pstate -> writingp = 0;
 376 #ifdef HAVE_POSIX
 377           scm_iprin1 ((scm_is_string (file)?
 378                        scm_basename (file, SCM_UNDEFINED) : file),
 379                       port, pstate);
 380 #else
 381           scm_iprin1 (file, port, pstate);
 382 #endif
 383           pstate -> writingp = 1;
 384         }
 385
 386       scm_putc_unlocked (':', port);
 387     }
 388   else if (scm_is_true (line))
 389     {
 390       int i, j=0;
 391       for (i = scm_to_int (line)+1; i > 0; i = i/10, j++)
 392         ;
 393       indent (4-j, port);
 394     }
 395
 396   if (scm_is_false (line))
 397     scm_puts_unlocked ("   ?", port);
 398   else
 399     scm_intprint (scm_to_int (line) + 1, 10, port);
 400   scm_puts_unlocked (": ", port);
 401 }
 402
 403 static void
 404 display_frame (SCM frame, int n, int nfield, int indentation,
 405                SCM sport, SCM port, scm_print_state *pstate)
 406 {
 407   int i, j;
 408
 409   /* display file name and line number */
 410   if (scm_is_true (SCM_PACK (SCM_SHOW_FILE_NAME)))
 411     display_backtrace_file_and_line (frame, port, pstate);
 412
 413   /* Check size of frame number. */
 414   for (i = 0, j = n; j > 0; ++i) j /= 10;
 415
 416   /* Number indentation. */
 417   indent (nfield - (i ? i : 1), port);
 418
 419   /* Frame number. */
 420   scm_iprin1 (scm_from_int (n), port, pstate);
 421
 422   /* Indentation. */
 423   indent (indentation, port);
 424
 425   /* Display an application. */
 426   display_application (frame, nfield + 1 + indentation, sport, port, pstate);
 427   scm_putc_unlocked ('\n', port);
 428 }
 429
 430 struct display_backtrace_args {
 431   SCM stack;
 432   SCM port;
 433   SCM first;
 434   SCM depth;
 435   SCM highlight_objects;
 436 };
 437
 438 static SCM
 439 display_backtrace_body (struct display_backtrace_args *a)
 440 #define FUNC_NAME "display_backtrace_body"
 441 {
 442   int n_frames, beg, end, n, i, j;
 443   int nfield, indentation;
 444   SCM frame, sport, print_state;
 445   SCM last_file;
 446   scm_print_state *pstate;
 447
 448   a->port = SCM_COERCE_OUTPORT (a->port);
 449
 450   /* Argument checking and extraction. */
 451   SCM_VALIDATE_STACK (1, a->stack);
 452   SCM_VALIDATE_OPOUTPORT (2, a->port);
 453   n_frames = scm_to_int (scm_stack_length (a->stack));
 454   n = scm_is_integer (a->depth) ? scm_to_int (a->depth) : SCM_BACKTRACE_DEPTH;
 455   if (SCM_BACKWARDS_P)
 456     {
 457       beg = scm_is_integer (a->first) ? scm_to_int (a->first) : 0;
 458       end = beg + n - 1;
 459       if (end >= n_frames)
 460         end = n_frames - 1;
 461       n = end - beg + 1;
 462     }
 463   else
 464     {
 465       if (scm_is_integer (a->first))
 466         {
 467           beg = scm_to_int (a->first);
 468           end = beg - n + 1;
 469           if (end < 0)
 470             end = 0;
 471         }
 472       else
 473         {
 474           beg = n - 1;
 475           end = 0;
 476           if (beg >= n_frames)
 477             beg = n_frames - 1;
 478         }
 479       n = beg - end + 1;
 480     }
 481   SCM_ASSERT (beg >= 0 && beg < n_frames, a->first, SCM_ARG3, s_display_backtrace);
 482   SCM_ASSERT (n > 0, a->depth, SCM_ARG4, s_display_backtrace);
 483
 484   /* Create a string port used for adaptation of printing parameters. */
 485   sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 486                          SCM_OPN | SCM_WRTNG,
 487                          FUNC_NAME);
 488
 489   /* Create a print state for printing of frames. */
 490   print_state = scm_make_print_state ();
 491   pstate = SCM_PRINT_STATE (print_state);
 492   pstate->writingp = 1;
 493   pstate->fancyp = 1;
 494   pstate->highlight_objects = a->highlight_objects;
 495
 496   /* Determine size of frame number field. */
 497   j = end;
 498   for (i = 0; j > 0; ++i) j /= 10;
 499   nfield = i ? i : 1;
 500
 501   /* Print frames. */
 502   indentation = 1;
 503   last_file = SCM_UNDEFINED;
 504   if (SCM_BACKWARDS_P)
 505     end++;
 506   else
 507     end--;
 508   for (i = beg; i != end; SCM_BACKWARDS_P ? ++i : --i)
 509     {
 510       frame = scm_stack_ref (a->stack, scm_from_int (i));
 511       if (!scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 512         display_backtrace_file (frame, &last_file, a->port, pstate);
 513       display_frame (frame, i, nfield, indentation, sport, a->port, pstate);
 514     }
 515
 516   scm_remember_upto_here_1 (print_state);
 517
 518   return SCM_UNSPECIFIED;
 519 }
 520 #undef FUNC_NAME
 521
 522 static SCM
 523 error_during_backtrace (void *data, SCM tag, SCM throw_args)
 524 {
 525   SCM port = SCM_PACK_POINTER (data);
 526
 527   scm_puts_unlocked ("Exception thrown while printing backtrace:\n", port);
 528   scm_print_exception (port, SCM_BOOL_F, tag, throw_args);
 529
 530   return SCM_UNSPECIFIED;
 531 }
 532
 533
 534 SCM_DEFINE (scm_display_backtrace_with_highlights, "display-backtrace", 2, 3, 0,
 535             (SCM stack, SCM port, SCM first, SCM depth, SCM highlights),
 536             "Display a backtrace to the output port @var{port}.  @var{stack}\n"
 537             "is the stack to take the backtrace from, @var{first} specifies\n"
 538             "where in the stack to start and @var{depth} how many frames\n"
 539             "to display.  @var{first} and @var{depth} can be @code{#f},\n"
 540             "which means that default values will be used.\n"
 541             "If @var{highlights} is given it should be a list; the elements\n"
 542             "of this list will be highlighted wherever they appear in the\n"
 543             "backtrace.")
 544 #define FUNC_NAME s_scm_display_backtrace_with_highlights
 545 {
 546   struct display_backtrace_args a;
 547   a.stack = stack;
 548   a.port  = port;
 549   a.first = first;
 550   a.depth = depth;
 551   if (SCM_UNBNDP (highlights))
 552     a.highlight_objects = SCM_EOL;
 553   else
 554     a.highlight_objects = highlights;
 555
 556   scm_internal_catch (SCM_BOOL_T,
 557                       (scm_t_catch_body) display_backtrace_body, &a,
 558                       (scm_t_catch_handler) error_during_backtrace, SCM_UNPACK_POINTER (port));
 559
 560   return SCM_UNSPECIFIED;
 561 }
 562 #undef FUNC_NAME
 563
 564 SCM
 565 scm_display_backtrace (SCM stack, SCM port, SCM first, SCM depth)
 566 {
 567   return scm_display_backtrace_with_highlights (stack, port, first, depth,
 568                                                 SCM_EOL);
 569 }
 570
 571 SCM_VARIABLE (scm_has_shown_backtrace_hint_p_var, "has-shown-backtrace-hint?");
 572
 573 SCM_DEFINE (scm_backtrace_with_highlights, "backtrace", 0, 1, 0,
 574             (SCM highlights),
 575             "Display a backtrace of the current stack to the current\n"
 576             "output port.  If @var{highlights} is given, it should be\n"
 577             "a list; the elements of this list will be highlighted\n"
 578             "wherever they appear in the backtrace.")
 579 #define FUNC_NAME s_scm_backtrace_with_highlights
 580 {
 581   SCM port = scm_current_output_port ();
 582   SCM stack = scm_make_stack (SCM_BOOL_T, SCM_EOL);
 583
 584   if (SCM_UNBNDP (highlights))
 585     highlights = SCM_EOL;
 586
 587   scm_newline (port);
 588   scm_puts_unlocked ("Backtrace:\n", port);
 589   scm_display_backtrace_with_highlights (stack, port, SCM_BOOL_F, SCM_BOOL_F,
 590                                          highlights);
 591   scm_newline (port);
 592
 593   return SCM_UNSPECIFIED;
 594 }
 595 #undef FUNC_NAME
 596
 597 SCM
 598 scm_backtrace (void)
 599 {
 600   return scm_backtrace_with_highlights (SCM_EOL);
 601 }
 602
 603 \f
 604
 605 void
 606 scm_init_backtrace ()
 607 {
 608   scm_c_define_gsubr ("print-exception", 4, 0, 0, boot_print_exception);
 609 #include "libguile/backtrace.x"
 610 }
 611
 612 /*
 613   Local Variables:
 614   c-file-style: "gnu"
 615   End:
 616 */