libguile/backtrace.c

   1 /* Printing of backtraces and error messages
   2  * Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006, 2009, 2010, 2011 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 License
   6  * as published by the Free Software Foundation; either version 3 of
   7  * the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful, but
  10  * 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
  17  * 02110-1301 USA
  18  */
  19
  20 #ifdef HAVE_CONFIG_H
  21 #  include <config.h>
  22 #endif
  23
  24 #include <stdio.h>
  25 #include <ctype.h>
  26
  27 #include "libguile/_scm.h"
  28
  29 #ifdef HAVE_UNISTD_H
  30 #include <unistd.h>
  31 #endif
  32 #ifdef HAVE_IO_H
  33 #include <io.h>
  34 #endif
  35
  36 #include "libguile/deprecation.h"
  37 #include "libguile/stacks.h"
  38 #include "libguile/srcprop.h"
  39 #include "libguile/struct.h"
  40 #include "libguile/strports.h"
  41 #include "libguile/throw.h"
  42 #include "libguile/fluids.h"
  43 #include "libguile/ports.h"
  44 #include "libguile/strings.h"
  45 #include "libguile/dynwind.h"
  46 #include "libguile/frames.h"
  47
  48 #include "libguile/validate.h"
  49 #include "libguile/backtrace.h"
  50 #include "libguile/filesys.h"
  51 #include "libguile/private-options.h"
  52
  53 /* {Error reporting and backtraces}
  54  *
  55  * Note that these functions shouldn't generate errors themselves.
  56  */
  57
  58 static SCM
  59 boot_print_exception (SCM port, SCM frame, SCM key, SCM args)
  60 #define FUNC_NAME "boot-print-exception"
  61 {
  62   scm_puts ("Throw to key ", port);
  63   scm_write (key, port);
  64   scm_puts (" with args ", port);
  65   scm_write (args, port);
  66   return SCM_UNSPECIFIED;
  67 }
  68 #undef FUNC_NAME
  69
  70 SCM
  71 scm_print_exception (SCM port, SCM frame, SCM key, SCM args)
  72 #define FUNC_NAME "print-exception"
  73 {
  74   static SCM print_exception = SCM_BOOL_F;
  75
  76   SCM_VALIDATE_OPOUTPORT (1, port);
  77   if (scm_is_true (frame))
  78     SCM_VALIDATE_FRAME (2, frame);
  79   SCM_VALIDATE_SYMBOL (3, key);
  80   SCM_VALIDATE_LIST (4, args);
  81
  82   if (scm_is_false (print_exception))
  83     print_exception =
  84       scm_module_variable (scm_the_root_module (),
  85                            scm_from_latin1_symbol ("print-exception"));
  86
  87   return scm_call_4 (scm_variable_ref (print_exception),
  88                      port, frame, key, args);
  89 }
  90 #undef FUNC_NAME
  91
  92
  93 \f
  94
  95 /* Print parameters for error messages. */
  96
  97 #define DISPLAY_ERROR_MESSAGE_MAX_LEVEL   7
  98 #define DISPLAY_ERROR_MESSAGE_MAX_LENGTH 10
  99
 100 /* Print parameters for failing expressions in error messages.
 101  * (See also `print_params' below for backtrace print parameters.)
 102  */
 103
 104 #define DISPLAY_EXPRESSION_MAX_LEVEL      2
 105 #define DISPLAY_EXPRESSION_MAX_LENGTH     3
 106
 107 #undef SCM_ASSERT
 108 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 109         if (!(_cond)) \
 110           return SCM_BOOL_F;
 111
 112
 113 void
 114 scm_display_error_message (SCM message, SCM args, SCM port)
 115 {
 116   scm_print_exception (port, SCM_BOOL_F, scm_misc_error_key,
 117                        scm_list_3 (SCM_BOOL_F, message, args));
 118 }
 119
 120
 121 /* The function scm_i_display_error prints out a detailed error message.  This
 122  * function will be called directly within libguile to signal error messages.
 123  * No parameter checks will be performed by scm_i_display_error.  Thus, User
 124  * code should rather use the function scm_display_error.
 125  */
 126 void
 127 scm_i_display_error (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest)
 128 {
 129   scm_print_exception (port, frame, scm_misc_error_key,
 130                        scm_list_3 (subr, message, args));
 131 }
 132
 133
 134 SCM_DEFINE (scm_display_error, "display-error", 6, 0, 0,
 135             (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest),
 136             "Display an error message to the output port @var{port}.\n"
 137             "@var{frame} is the frame in which the error occurred, @var{subr} is\n"
 138             "the name of the procedure in which the error occurred and\n"
 139             "@var{message} is the actual error message, which may contain\n"
 140             "formatting instructions. These will format the arguments in\n"
 141             "the list @var{args} accordingly.  @var{rest} is currently\n"
 142             "ignored.")
 143 #define FUNC_NAME s_scm_display_error
 144 {
 145   SCM_VALIDATE_OUTPUT_PORT (2, port);
 146
 147   scm_i_display_error (frame, port, subr, message, args, rest);
 148
 149   return SCM_UNSPECIFIED;
 150 }
 151 #undef FUNC_NAME
 152
 153
 154 typedef struct {
 155   int level;
 156   int length;
 157 } print_params_t;
 158
 159 static int n_print_params = 9;
 160 static print_params_t default_print_params[] = {
 161   { 4, 9 }, { 4, 3 },
 162   { 3, 4 }, { 3, 3 },
 163   { 2, 4 }, { 2, 3 },
 164   { 1, 4 }, { 1, 3 }, { 1, 2 }
 165 };
 166 static print_params_t *print_params = default_print_params;
 167
 168 #ifdef GUILE_DEBUG
 169 SCM_DEFINE (scm_set_print_params_x, "set-print-params!", 1, 0, 0,
 170            (SCM params),
 171             "Set the print parameters to the values from @var{params}.\n"
 172             "@var{params} must be a list of two-element lists which must\n"
 173             "hold two integer values.")
 174 #define FUNC_NAME s_scm_set_print_params_x
 175 {
 176   int i;
 177   int n;
 178   SCM ls;
 179   print_params_t *new_params;
 180
 181   SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, params, n);
 182   for (ls = params; !SCM_NULL_OR_NIL_P (ls); ls = SCM_CDR (ls))
 183     SCM_ASSERT (scm_ilength (SCM_CAR (params)) == 2
 184                 && scm_is_unsigned_integer (SCM_CAAR (ls), 0, INT_MAX)
 185                 && scm_is_unsigned_integer (SCM_CADAR (ls), 0, INT_MAX),
 186                 params,
 187                 SCM_ARG2,
 188                 s_scm_set_print_params_x);
 189   new_params = scm_malloc (n * sizeof (print_params_t));
 190   if (print_params != default_print_params)
 191     free (print_params);
 192   print_params = new_params;
 193   for (i = 0; i < n; ++i)
 194     {
 195       print_params[i].level = scm_to_int (SCM_CAAR (params));
 196       print_params[i].length = scm_to_int (SCM_CADAR (params));
 197       params = SCM_CDR (params);
 198     }
 199   n_print_params = n;
 200   return SCM_UNSPECIFIED;
 201 }
 202 #undef FUNC_NAME
 203 #endif
 204
 205 static void
 206 indent (int n, SCM port)
 207 {
 208   int i;
 209   for (i = 0; i < n; ++i)
 210     scm_putc (' ', port);
 211 }
 212
 213 static void
 214 display_frame_expr (char *hdr, SCM exp, char *tlr, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 215 {
 216   int i = 0, n;
 217   scm_t_ptob_descriptor *ptob = scm_ptobs + SCM_PTOBNUM (sport);
 218   do
 219     {
 220       pstate->length = print_params[i].length;
 221       ptob->seek (sport, 0, SEEK_SET);
 222       if (scm_is_pair (exp))
 223         {
 224           pstate->level = print_params[i].level - 1;
 225           scm_iprlist (hdr, exp, tlr[0], sport, pstate);
 226           scm_puts (&tlr[1], sport);
 227         }
 228       else
 229         {
 230           pstate->level = print_params[i].level;
 231           scm_iprin1 (exp, sport, pstate);
 232         }
 233       ptob->flush (sport);
 234       n = ptob->seek (sport, 0, SEEK_CUR);
 235       ++i;
 236     }
 237   while (indentation + n > SCM_BACKTRACE_WIDTH && i < n_print_params);
 238   ptob->truncate (sport, n);
 239
 240   scm_display (scm_strport_to_string (sport), port);
 241 }
 242
 243 static void
 244 display_application (SCM frame, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 245 {
 246   SCM proc = scm_frame_procedure (frame);
 247   SCM name = (scm_is_true (scm_procedure_p (proc))
 248               ? scm_procedure_name (proc)
 249               : SCM_BOOL_F);
 250   display_frame_expr ("[",
 251                       scm_cons (scm_is_true (name) ? name : proc,
 252                                 scm_frame_arguments (frame)),
 253                       "]",
 254                       indentation,
 255                       sport,
 256                       port,
 257                       pstate);
 258 }
 259
 260 SCM_DEFINE (scm_display_application, "display-application", 1, 2, 0,
 261            (SCM frame, SCM port, SCM indent),
 262             "Display a procedure application @var{frame} to the output port\n"
 263             "@var{port}. @var{indent} specifies the indentation of the\n"
 264             "output.")
 265 #define FUNC_NAME s_scm_display_application
 266 {
 267   SCM_VALIDATE_FRAME (1, frame);
 268   if (SCM_UNBNDP (port))
 269     port = scm_current_output_port ();
 270   else
 271     SCM_VALIDATE_OPOUTPORT (2, port);
 272   if (SCM_UNBNDP (indent))
 273     indent = SCM_INUM0;
 274
 275   /* Display an application. */
 276   {
 277     SCM sport, print_state;
 278     scm_print_state *pstate;
 279
 280     /* Create a string port used for adaptation of printing parameters. */
 281     sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 282                            SCM_OPN | SCM_WRTNG,
 283                            FUNC_NAME);
 284
 285     /* Create a print state for printing of frames. */
 286     print_state = scm_make_print_state ();
 287     pstate = SCM_PRINT_STATE (print_state);
 288     pstate->writingp = 1;
 289     pstate->fancyp = 1;
 290
 291     display_application (frame, scm_to_int (indent), sport, port, pstate);
 292     return SCM_BOOL_T;
 293   }
 294 }
 295 #undef FUNC_NAME
 296
 297 SCM_SYMBOL (sym_base, "base");
 298
 299 static void
 300 display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
 301 {
 302   SCM source = scm_frame_source (frame);
 303   *file = *line = SCM_BOOL_F;
 304   if (scm_is_pair (source)
 305       && scm_is_pair (scm_cdr (source))
 306       && scm_is_pair (scm_cddr (source))
 307       && !scm_is_pair (scm_cdddr (source)))
 308     {
 309       /* (addr . (filename . (line . column))), from vm compilation */
 310       *file = scm_cadr (source);
 311       *line = scm_caddr (source);
 312     }
 313 }
 314
 315 static void
 316 display_backtrace_file (frame, last_file, port, pstate)
 317      SCM frame;
 318      SCM *last_file;
 319      SCM port;
 320      scm_print_state *pstate;
 321 {
 322   SCM file, line;
 323
 324   display_backtrace_get_file_line (frame, &file, &line);
 325
 326   if (scm_is_true (scm_equal_p (file, *last_file)))
 327     return;
 328
 329   *last_file = file;
 330
 331   scm_puts ("In ", port);
 332   if (scm_is_false (file))
 333     if (scm_is_false (line))
 334       scm_puts ("unknown file", port);
 335     else
 336       scm_puts ("current input", port);
 337   else
 338     {
 339       pstate->writingp = 0;
 340       scm_iprin1 (file, port, pstate);
 341       pstate->writingp = 1;
 342     }
 343   scm_puts (":\n", port);
 344 }
 345
 346 static void
 347 display_backtrace_file_and_line (SCM frame, SCM port, scm_print_state *pstate)
 348 {
 349   SCM file, line;
 350
 351   display_backtrace_get_file_line (frame, &file, &line);
 352
 353   if (scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 354     {
 355       if (scm_is_false (file))
 356         {
 357           if (scm_is_false (line))
 358             scm_putc ('?', port);
 359           else
 360             scm_puts ("<stdin>", port);
 361         }
 362       else
 363         {
 364           pstate -> writingp = 0;
 365 #ifdef HAVE_POSIX
 366           scm_iprin1 ((scm_is_string (file)?
 367                        scm_basename (file, SCM_UNDEFINED) : file),
 368                       port, pstate);
 369 #else
 370           scm_iprin1 (file, port, pstate);
 371 #endif
 372           pstate -> writingp = 1;
 373         }
 374
 375       scm_putc (':', port);
 376     }
 377   else if (scm_is_true (line))
 378     {
 379       int i, j=0;
 380       for (i = scm_to_int (line)+1; i > 0; i = i/10, j++)
 381         ;
 382       indent (4-j, port);
 383     }
 384
 385   if (scm_is_false (line))
 386     scm_puts ("   ?", port);
 387   else
 388     scm_intprint (scm_to_int (line) + 1, 10, port);
 389   scm_puts (": ", port);
 390 }
 391
 392 static void
 393 display_frame (SCM frame, int n, int nfield, int indentation,
 394                SCM sport, SCM port, scm_print_state *pstate)
 395 {
 396   int i, j;
 397
 398   /* display file name and line number */
 399   if (scm_is_true (SCM_PACK (SCM_SHOW_FILE_NAME)))
 400     display_backtrace_file_and_line (frame, port, pstate);
 401
 402   /* Check size of frame number. */
 403   for (i = 0, j = n; j > 0; ++i) j /= 10;
 404
 405   /* Number indentation. */
 406   indent (nfield - (i ? i : 1), port);
 407
 408   /* Frame number. */
 409   scm_iprin1 (scm_from_int (n), port, pstate);
 410
 411   /* Indentation. */
 412   indent (indentation, port);
 413
 414   /* Display an application. */
 415   display_application (frame, nfield + 1 + indentation, sport, port, pstate);
 416   scm_putc ('\n', port);
 417 }
 418
 419 struct display_backtrace_args {
 420   SCM stack;
 421   SCM port;
 422   SCM first;
 423   SCM depth;
 424   SCM highlight_objects;
 425 };
 426
 427 static SCM
 428 display_backtrace_body (struct display_backtrace_args *a)
 429 #define FUNC_NAME "display_backtrace_body"
 430 {
 431   int n_frames, beg, end, n, i, j;
 432   int nfield, indentation;
 433   SCM frame, sport, print_state;
 434   SCM last_file;
 435   scm_print_state *pstate;
 436
 437   a->port = SCM_COERCE_OUTPORT (a->port);
 438
 439   /* Argument checking and extraction. */
 440   SCM_VALIDATE_STACK (1, a->stack);
 441   SCM_VALIDATE_OPOUTPORT (2, a->port);
 442   n_frames = scm_to_int (scm_stack_length (a->stack));
 443   n = scm_is_integer (a->depth) ? scm_to_int (a->depth) : SCM_BACKTRACE_DEPTH;
 444   if (SCM_BACKWARDS_P)
 445     {
 446       beg = scm_is_integer (a->first) ? scm_to_int (a->first) : 0;
 447       end = beg + n - 1;
 448       if (end >= n_frames)
 449         end = n_frames - 1;
 450       n = end - beg + 1;
 451     }
 452   else
 453     {
 454       if (scm_is_integer (a->first))
 455         {
 456           beg = scm_to_int (a->first);
 457           end = beg - n + 1;
 458           if (end < 0)
 459             end = 0;
 460         }
 461       else
 462         {
 463           beg = n - 1;
 464           end = 0;
 465           if (beg >= n_frames)
 466             beg = n_frames - 1;
 467         }
 468       n = beg - end + 1;
 469     }
 470   SCM_ASSERT (beg >= 0 && beg < n_frames, a->first, SCM_ARG3, s_display_backtrace);
 471   SCM_ASSERT (n > 0, a->depth, SCM_ARG4, s_display_backtrace);
 472
 473   /* Create a string port used for adaptation of printing parameters. */
 474   sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 475                          SCM_OPN | SCM_WRTNG,
 476                          FUNC_NAME);
 477
 478   /* Create a print state for printing of frames. */
 479   print_state = scm_make_print_state ();
 480   pstate = SCM_PRINT_STATE (print_state);
 481   pstate->writingp = 1;
 482   pstate->fancyp = 1;
 483   pstate->highlight_objects = a->highlight_objects;
 484
 485   /* Determine size of frame number field. */
 486   j = end;
 487   for (i = 0; j > 0; ++i) j /= 10;
 488   nfield = i ? i : 1;
 489
 490   /* Print frames. */
 491   indentation = 1;
 492   last_file = SCM_UNDEFINED;
 493   if (SCM_BACKWARDS_P)
 494     end++;
 495   else
 496     end--;
 497   for (i = beg; i != end; SCM_BACKWARDS_P ? ++i : --i)
 498     {
 499       frame = scm_stack_ref (a->stack, scm_from_int (i));
 500       if (!scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 501         display_backtrace_file (frame, &last_file, a->port, pstate);
 502       display_frame (frame, i, nfield, indentation, sport, a->port, pstate);
 503     }
 504
 505   scm_remember_upto_here_1 (print_state);
 506
 507   return SCM_UNSPECIFIED;
 508 }
 509 #undef FUNC_NAME
 510
 511 static SCM
 512 error_during_backtrace (void *data, SCM tag, SCM throw_args)
 513 {
 514   SCM port = PTR2SCM (data);
 515
 516   scm_puts ("Exception thrown while printing backtrace:\n", port);
 517   scm_print_exception (port, SCM_BOOL_F, tag, throw_args);
 518
 519   return SCM_UNSPECIFIED;
 520 }
 521
 522
 523 SCM_DEFINE (scm_display_backtrace_with_highlights, "display-backtrace", 2, 3, 0,
 524             (SCM stack, SCM port, SCM first, SCM depth, SCM highlights),
 525             "Display a backtrace to the output port @var{port}.  @var{stack}\n"
 526             "is the stack to take the backtrace from, @var{first} specifies\n"
 527             "where in the stack to start and @var{depth} how many frames\n"
 528             "to display.  @var{first} and @var{depth} can be @code{#f},\n"
 529             "which means that default values will be used.\n"
 530             "If @var{highlights} is given it should be a list; the elements\n"
 531             "of this list will be highlighted wherever they appear in the\n"
 532             "backtrace.")
 533 #define FUNC_NAME s_scm_display_backtrace_with_highlights
 534 {
 535   struct display_backtrace_args a;
 536   a.stack = stack;
 537   a.port  = port;
 538   a.first = first;
 539   a.depth = depth;
 540   if (SCM_UNBNDP (highlights))
 541     a.highlight_objects = SCM_EOL;
 542   else
 543     a.highlight_objects = highlights;
 544
 545   scm_internal_catch (SCM_BOOL_T,
 546                       (scm_t_catch_body) display_backtrace_body, &a,
 547                       (scm_t_catch_handler) error_during_backtrace, SCM2PTR (port));
 548
 549   return SCM_UNSPECIFIED;
 550 }
 551 #undef FUNC_NAME
 552
 553 SCM
 554 scm_display_backtrace (SCM stack, SCM port, SCM first, SCM depth)
 555 {
 556   return scm_display_backtrace_with_highlights (stack, port, first, depth,
 557                                                 SCM_EOL);
 558 }
 559
 560 SCM_VARIABLE (scm_has_shown_backtrace_hint_p_var, "has-shown-backtrace-hint?");
 561
 562 SCM_DEFINE (scm_backtrace_with_highlights, "backtrace", 0, 1, 0,
 563             (SCM highlights),
 564             "Display a backtrace of the current stack to the current\n"
 565             "output port.  If @var{highlights} is given, it should be\n"
 566             "a list; the elements of this list will be highlighted\n"
 567             "wherever they appear in the backtrace.")
 568 #define FUNC_NAME s_scm_backtrace_with_highlights
 569 {
 570   SCM port = scm_current_output_port ();
 571   SCM stack = scm_make_stack (SCM_BOOL_T, SCM_EOL);
 572
 573   if (SCM_UNBNDP (highlights))
 574     highlights = SCM_EOL;
 575
 576   scm_newline (port);
 577   scm_puts ("Backtrace:\n", port);
 578   scm_display_backtrace_with_highlights (stack, port, SCM_BOOL_F, SCM_BOOL_F,
 579                                          highlights);
 580   scm_newline (port);
 581
 582   return SCM_UNSPECIFIED;
 583 }
 584 #undef FUNC_NAME
 585
 586 SCM
 587 scm_backtrace (void)
 588 {
 589   return scm_backtrace_with_highlights (SCM_EOL);
 590 }
 591
 592 \f
 593
 594 void
 595 scm_init_backtrace ()
 596 {
 597   scm_c_define_gsubr ("print-exception", 4, 0, 0, boot_print_exception);
 598 #include "libguile/backtrace.x"
 599 }
 600
 601 /*
 602   Local Variables:
 603   c-file-style: "gnu"
 604   End:
 605 */