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, 2014 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_unlocked ("Throw to key ", port);
  63   scm_write (key, port);
  64   scm_puts_unlocked (" with args ", port);
  65   scm_write (args, port);
  66   return SCM_UNSPECIFIED;
  67 }
  68 #undef FUNC_NAME
  69
  70 static SCM print_exception_var;
  71
  72 static void
  73 init_print_exception_var (void)
  74 {
  75   print_exception_var
  76     = scm_module_variable (scm_the_root_module (),
  77                            scm_from_latin1_symbol ("print-exception"));
  78 }
  79
  80 SCM
  81 scm_print_exception (SCM port, SCM frame, SCM key, SCM args)
  82 #define FUNC_NAME "print-exception"
  83 {
  84   static scm_i_pthread_once_t once = SCM_I_PTHREAD_ONCE_INIT;
  85   scm_i_pthread_once (&once, init_print_exception_var);
  86
  87   SCM_VALIDATE_OPOUTPORT (1, port);
  88   if (scm_is_true (frame))
  89     SCM_VALIDATE_FRAME (2, frame);
  90   SCM_VALIDATE_SYMBOL (3, key);
  91   SCM_VALIDATE_LIST (4, args);
  92
  93   return scm_call_4 (scm_variable_ref (print_exception_var),
  94                      port, frame, key, args);
  95 }
  96 #undef FUNC_NAME
  97
  98
  99 \f
 100
 101 /* Print parameters for error messages. */
 102
 103 #define DISPLAY_ERROR_MESSAGE_MAX_LEVEL   7
 104 #define DISPLAY_ERROR_MESSAGE_MAX_LENGTH 10
 105
 106 /* Print parameters for failing expressions in error messages.
 107  * (See also `print_params' below for backtrace print parameters.)
 108  */
 109
 110 #define DISPLAY_EXPRESSION_MAX_LEVEL      2
 111 #define DISPLAY_EXPRESSION_MAX_LENGTH     3
 112
 113 #undef SCM_ASSERT
 114 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
 115         if (!(_cond)) \
 116           return SCM_BOOL_F;
 117
 118
 119 void
 120 scm_display_error_message (SCM message, SCM args, SCM port)
 121 {
 122   scm_print_exception (port, SCM_BOOL_F, scm_misc_error_key,
 123                        scm_list_3 (SCM_BOOL_F, message, args));
 124 }
 125
 126
 127 /* The function scm_i_display_error prints out a detailed error message.  This
 128  * function will be called directly within libguile to signal error messages.
 129  * No parameter checks will be performed by scm_i_display_error.  Thus, User
 130  * code should rather use the function scm_display_error.
 131  */
 132 void
 133 scm_i_display_error (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest)
 134 {
 135   scm_print_exception (port, frame, scm_misc_error_key,
 136                        scm_list_3 (subr, message, args));
 137 }
 138
 139
 140 SCM_DEFINE (scm_display_error, "display-error", 6, 0, 0,
 141             (SCM frame, SCM port, SCM subr, SCM message, SCM args, SCM rest),
 142             "Display an error message to the output port @var{port}.\n"
 143             "@var{frame} is the frame in which the error occurred, @var{subr} is\n"
 144             "the name of the procedure in which the error occurred and\n"
 145             "@var{message} is the actual error message, which may contain\n"
 146             "formatting instructions. These will format the arguments in\n"
 147             "the list @var{args} accordingly.  @var{rest} is currently\n"
 148             "ignored.")
 149 #define FUNC_NAME s_scm_display_error
 150 {
 151   SCM_VALIDATE_OUTPUT_PORT (2, port);
 152
 153 #if SCM_ENABLE_DEPRECATED
 154   if (SCM_STACKP (frame))
 155     {
 156       scm_c_issue_deprecation_warning
 157         ("Passing a stack as the first argument to `scm_display_error' is "
 158          "deprecated.  Pass a frame instead.");
 159       if (SCM_STACK_LENGTH (frame))
 160         frame = scm_stack_ref (frame, SCM_INUM0);
 161       else
 162         frame = SCM_BOOL_F;
 163     }
 164 #endif
 165
 166   scm_i_display_error (frame, port, subr, message, args, rest);
 167
 168   return SCM_UNSPECIFIED;
 169 }
 170 #undef FUNC_NAME
 171
 172
 173 typedef struct {
 174   int level;
 175   int length;
 176 } print_params_t;
 177
 178 static int n_print_params = 9;
 179 static print_params_t default_print_params[] = {
 180   { 4, 9 }, { 4, 3 },
 181   { 3, 4 }, { 3, 3 },
 182   { 2, 4 }, { 2, 3 },
 183   { 1, 4 }, { 1, 3 }, { 1, 2 }
 184 };
 185 static print_params_t *print_params = default_print_params;
 186
 187 #ifdef GUILE_DEBUG
 188 SCM_DEFINE (scm_set_print_params_x, "set-print-params!", 1, 0, 0,
 189            (SCM params),
 190             "Set the print parameters to the values from @var{params}.\n"
 191             "@var{params} must be a list of two-element lists which must\n"
 192             "hold two integer values.")
 193 #define FUNC_NAME s_scm_set_print_params_x
 194 {
 195   int i;
 196   int n;
 197   SCM ls;
 198   print_params_t *new_params;
 199
 200   SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, params, n);
 201   for (ls = params; !SCM_NULL_OR_NIL_P (ls); ls = SCM_CDR (ls))
 202     SCM_ASSERT (scm_ilength (SCM_CAR (params)) == 2
 203                 && scm_is_unsigned_integer (SCM_CAAR (ls), 0, INT_MAX)
 204                 && scm_is_unsigned_integer (SCM_CADAR (ls), 0, INT_MAX),
 205                 params,
 206                 SCM_ARG2,
 207                 s_scm_set_print_params_x);
 208   new_params = scm_malloc (n * sizeof (print_params_t));
 209   if (print_params != default_print_params)
 210     free (print_params);
 211   print_params = new_params;
 212   for (i = 0; i < n; ++i)
 213     {
 214       print_params[i].level = scm_to_int (SCM_CAAR (params));
 215       print_params[i].length = scm_to_int (SCM_CADAR (params));
 216       params = SCM_CDR (params);
 217     }
 218   n_print_params = n;
 219   return SCM_UNSPECIFIED;
 220 }
 221 #undef FUNC_NAME
 222 #endif
 223
 224 static void
 225 indent (int n, SCM port)
 226 {
 227   int i;
 228   for (i = 0; i < n; ++i)
 229     scm_putc_unlocked (' ', port);
 230 }
 231
 232 static void
 233 display_frame_expr (char *hdr, SCM exp, char *tlr, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 234 {
 235   int i = 0, n;
 236   scm_t_ptob_descriptor *ptob = SCM_PORT_DESCRIPTOR (sport);
 237   do
 238     {
 239       pstate->length = print_params[i].length;
 240       ptob->seek (sport, 0, SEEK_SET);
 241       if (scm_is_pair (exp))
 242         {
 243           pstate->level = print_params[i].level - 1;
 244           scm_iprlist (hdr, exp, tlr[0], sport, pstate);
 245           scm_puts_unlocked (&tlr[1], sport);
 246         }
 247       else
 248         {
 249           pstate->level = print_params[i].level;
 250           scm_iprin1 (exp, sport, pstate);
 251         }
 252       ptob->flush (sport);
 253       n = ptob->seek (sport, 0, SEEK_CUR);
 254       ++i;
 255     }
 256   while (indentation + n > SCM_BACKTRACE_WIDTH && i < n_print_params);
 257   ptob->truncate (sport, n);
 258
 259   scm_display (scm_strport_to_string (sport), port);
 260 }
 261
 262 static void
 263 display_application (SCM frame, int indentation, SCM sport, SCM port, scm_print_state *pstate)
 264 {
 265   display_frame_expr ("[", scm_frame_call_representation (frame), "]",
 266                       indentation,
 267                       sport,
 268                       port,
 269                       pstate);
 270 }
 271
 272 SCM_DEFINE (scm_display_application, "display-application", 1, 2, 0,
 273            (SCM frame, SCM port, SCM indent),
 274             "Display a procedure application @var{frame} to the output port\n"
 275             "@var{port}. @var{indent} specifies the indentation of the\n"
 276             "output.")
 277 #define FUNC_NAME s_scm_display_application
 278 {
 279   SCM_VALIDATE_FRAME (1, frame);
 280   if (SCM_UNBNDP (port))
 281     port = scm_current_output_port ();
 282   else
 283     SCM_VALIDATE_OPOUTPORT (2, port);
 284   if (SCM_UNBNDP (indent))
 285     indent = SCM_INUM0;
 286
 287   /* Display an application. */
 288   {
 289     SCM sport, print_state;
 290     scm_print_state *pstate;
 291
 292     /* Create a string port used for adaptation of printing parameters. */
 293     sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 294                            SCM_OPN | SCM_WRTNG,
 295                            FUNC_NAME);
 296
 297     /* Create a print state for printing of frames. */
 298     print_state = scm_make_print_state ();
 299     pstate = SCM_PRINT_STATE (print_state);
 300     pstate->writingp = 1;
 301     pstate->fancyp = 1;
 302
 303     display_application (frame, scm_to_int (indent), sport, port, pstate);
 304     return SCM_BOOL_T;
 305   }
 306 }
 307 #undef FUNC_NAME
 308
 309 SCM_SYMBOL (sym_base, "base");
 310
 311 static void
 312 display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
 313 {
 314   SCM source = scm_frame_source (frame);
 315   *file = *line = SCM_BOOL_F;
 316   if (scm_is_pair (source)
 317       && scm_is_pair (scm_cdr (source))
 318       && scm_is_pair (scm_cddr (source))
 319       && !scm_is_pair (scm_cdddr (source)))
 320     {
 321       /* (addr . (filename . (line . column))), from vm compilation */
 322       *file = scm_cadr (source);
 323       *line = scm_caddr (source);
 324     }
 325 }
 326
 327 static void
 328 display_backtrace_file (frame, last_file, port, pstate)
 329      SCM frame;
 330      SCM *last_file;
 331      SCM port;
 332      scm_print_state *pstate;
 333 {
 334   SCM file, line;
 335
 336   display_backtrace_get_file_line (frame, &file, &line);
 337
 338   if (scm_is_true (scm_equal_p (file, *last_file)))
 339     return;
 340
 341   *last_file = file;
 342
 343   scm_puts_unlocked ("In ", port);
 344   if (scm_is_false (file))
 345     if (scm_is_false (line))
 346       scm_puts_unlocked ("unknown file", port);
 347     else
 348       scm_puts_unlocked ("current input", port);
 349   else
 350     {
 351       pstate->writingp = 0;
 352       scm_iprin1 (file, port, pstate);
 353       pstate->writingp = 1;
 354     }
 355   scm_puts_unlocked (":\n", port);
 356 }
 357
 358 static void
 359 display_backtrace_file_and_line (SCM frame, SCM port, scm_print_state *pstate)
 360 {
 361   SCM file, line;
 362
 363   display_backtrace_get_file_line (frame, &file, &line);
 364
 365   if (scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 366     {
 367       if (scm_is_false (file))
 368         {
 369           if (scm_is_false (line))
 370             scm_putc_unlocked ('?', port);
 371           else
 372             scm_puts_unlocked ("<stdin>", port);
 373         }
 374       else
 375         {
 376           pstate -> writingp = 0;
 377 #ifdef HAVE_POSIX
 378           scm_iprin1 ((scm_is_string (file)?
 379                        scm_basename (file, SCM_UNDEFINED) : file),
 380                       port, pstate);
 381 #else
 382           scm_iprin1 (file, port, pstate);
 383 #endif
 384           pstate -> writingp = 1;
 385         }
 386
 387       scm_putc_unlocked (':', port);
 388     }
 389   else if (scm_is_true (line))
 390     {
 391       int i, j=0;
 392       for (i = scm_to_int (line)+1; i > 0; i = i/10, j++)
 393         ;
 394       indent (4-j, port);
 395     }
 396
 397   if (scm_is_false (line))
 398     scm_puts_unlocked ("   ?", port);
 399   else
 400     scm_intprint (scm_to_int (line) + 1, 10, port);
 401   scm_puts_unlocked (": ", port);
 402 }
 403
 404 static void
 405 display_frame (SCM frame, int n, int nfield, int indentation,
 406                SCM sport, SCM port, scm_print_state *pstate)
 407 {
 408   int i, j;
 409
 410   /* display file name and line number */
 411   if (scm_is_true (SCM_PACK (SCM_SHOW_FILE_NAME)))
 412     display_backtrace_file_and_line (frame, port, pstate);
 413
 414   /* Check size of frame number. */
 415   for (i = 0, j = n; j > 0; ++i) j /= 10;
 416
 417   /* Number indentation. */
 418   indent (nfield - (i ? i : 1), port);
 419
 420   /* Frame number. */
 421   scm_iprin1 (scm_from_int (n), port, pstate);
 422
 423   /* Indentation. */
 424   indent (indentation, port);
 425
 426   /* Display an application. */
 427   display_application (frame, nfield + 1 + indentation, sport, port, pstate);
 428   scm_putc_unlocked ('\n', port);
 429 }
 430
 431 struct display_backtrace_args {
 432   SCM stack;
 433   SCM port;
 434   SCM first;
 435   SCM depth;
 436   SCM highlight_objects;
 437 };
 438
 439 static SCM
 440 display_backtrace_body (struct display_backtrace_args *a)
 441 #define FUNC_NAME "display_backtrace_body"
 442 {
 443   int n_frames, beg, end, n, i, j;
 444   int nfield, indentation;
 445   SCM frame, sport, print_state;
 446   SCM last_file;
 447   scm_print_state *pstate;
 448
 449   a->port = SCM_COERCE_OUTPORT (a->port);
 450
 451   /* Argument checking and extraction. */
 452   SCM_VALIDATE_STACK (1, a->stack);
 453   SCM_VALIDATE_OPOUTPORT (2, a->port);
 454   n_frames = scm_to_int (scm_stack_length (a->stack));
 455   n = scm_is_integer (a->depth) ? scm_to_int (a->depth) : SCM_BACKTRACE_DEPTH;
 456   if (SCM_BACKWARDS_P)
 457     {
 458       beg = scm_is_integer (a->first) ? scm_to_int (a->first) : 0;
 459       end = beg + n - 1;
 460       if (end >= n_frames)
 461         end = n_frames - 1;
 462       n = end - beg + 1;
 463     }
 464   else
 465     {
 466       if (scm_is_integer (a->first))
 467         {
 468           beg = scm_to_int (a->first);
 469           end = beg - n + 1;
 470           if (end < 0)
 471             end = 0;
 472         }
 473       else
 474         {
 475           beg = n - 1;
 476           end = 0;
 477           if (beg >= n_frames)
 478             beg = n_frames - 1;
 479         }
 480       n = beg - end + 1;
 481     }
 482   SCM_ASSERT (beg >= 0 && beg < n_frames, a->first, SCM_ARG3, s_display_backtrace);
 483   SCM_ASSERT (n > 0, a->depth, SCM_ARG4, s_display_backtrace);
 484
 485   /* Create a string port used for adaptation of printing parameters. */
 486   sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 487                          SCM_OPN | SCM_WRTNG,
 488                          FUNC_NAME);
 489
 490   /* Create a print state for printing of frames. */
 491   print_state = scm_make_print_state ();
 492   pstate = SCM_PRINT_STATE (print_state);
 493   pstate->writingp = 1;
 494   pstate->fancyp = 1;
 495   pstate->highlight_objects = a->highlight_objects;
 496
 497   /* Determine size of frame number field. */
 498   j = end;
 499   for (i = 0; j > 0; ++i) j /= 10;
 500   nfield = i ? i : 1;
 501
 502   /* Print frames. */
 503   indentation = 1;
 504   last_file = SCM_UNDEFINED;
 505   if (SCM_BACKWARDS_P)
 506     end++;
 507   else
 508     end--;
 509   for (i = beg; i != end; SCM_BACKWARDS_P ? ++i : --i)
 510     {
 511       frame = scm_stack_ref (a->stack, scm_from_int (i));
 512       if (!scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 513         display_backtrace_file (frame, &last_file, a->port, pstate);
 514       display_frame (frame, i, nfield, indentation, sport, a->port, pstate);
 515     }
 516
 517   scm_remember_upto_here_1 (print_state);
 518
 519   return SCM_UNSPECIFIED;
 520 }
 521 #undef FUNC_NAME
 522
 523 static SCM
 524 error_during_backtrace (void *data, SCM tag, SCM throw_args)
 525 {
 526   SCM port = SCM_PACK_POINTER (data);
 527
 528   scm_puts_unlocked ("Exception thrown while printing backtrace:\n", port);
 529   scm_print_exception (port, SCM_BOOL_F, tag, throw_args);
 530
 531   return SCM_UNSPECIFIED;
 532 }
 533
 534
 535 SCM_DEFINE (scm_display_backtrace_with_highlights, "display-backtrace", 2, 3, 0,
 536             (SCM stack, SCM port, SCM first, SCM depth, SCM highlights),
 537             "Display a backtrace to the output port @var{port}.  @var{stack}\n"
 538             "is the stack to take the backtrace from, @var{first} specifies\n"
 539             "where in the stack to start and @var{depth} how many frames\n"
 540             "to display.  @var{first} and @var{depth} can be @code{#f},\n"
 541             "which means that default values will be used.\n"
 542             "If @var{highlights} is given it should be a list; the elements\n"
 543             "of this list will be highlighted wherever they appear in the\n"
 544             "backtrace.")
 545 #define FUNC_NAME s_scm_display_backtrace_with_highlights
 546 {
 547   struct display_backtrace_args a;
 548   a.stack = stack;
 549   a.port  = port;
 550   a.first = first;
 551   a.depth = depth;
 552   if (SCM_UNBNDP (highlights))
 553     a.highlight_objects = SCM_EOL;
 554   else
 555     a.highlight_objects = highlights;
 556
 557   scm_internal_catch (SCM_BOOL_T,
 558                       (scm_t_catch_body) display_backtrace_body, &a,
 559                       (scm_t_catch_handler) error_during_backtrace, SCM_UNPACK_POINTER (port));
 560
 561   return SCM_UNSPECIFIED;
 562 }
 563 #undef FUNC_NAME
 564
 565 SCM
 566 scm_display_backtrace (SCM stack, SCM port, SCM first, SCM depth)
 567 {
 568   return scm_display_backtrace_with_highlights (stack, port, first, depth,
 569                                                 SCM_EOL);
 570 }
 571
 572 SCM_VARIABLE (scm_has_shown_backtrace_hint_p_var, "has-shown-backtrace-hint?");
 573
 574 SCM_DEFINE (scm_backtrace_with_highlights, "backtrace", 0, 1, 0,
 575             (SCM highlights),
 576             "Display a backtrace of the current stack to the current\n"
 577             "output port.  If @var{highlights} is given, it should be\n"
 578             "a list; the elements of this list will be highlighted\n"
 579             "wherever they appear in the backtrace.")
 580 #define FUNC_NAME s_scm_backtrace_with_highlights
 581 {
 582   SCM port = scm_current_output_port ();
 583   SCM stack = scm_make_stack (SCM_BOOL_T, SCM_EOL);
 584
 585   if (SCM_UNBNDP (highlights))
 586     highlights = SCM_EOL;
 587
 588   scm_newline (port);
 589   scm_puts_unlocked ("Backtrace:\n", port);
 590   scm_display_backtrace_with_highlights (stack, port, SCM_BOOL_F, SCM_BOOL_F,
 591                                          highlights);
 592   scm_newline (port);
 593
 594   return SCM_UNSPECIFIED;
 595 }
 596 #undef FUNC_NAME
 597
 598 SCM
 599 scm_backtrace (void)
 600 {
 601   return scm_backtrace_with_highlights (SCM_EOL);
 602 }
 603
 604 \f
 605
 606 void
 607 scm_init_backtrace ()
 608 {
 609   scm_c_define_gsubr ("print-exception", 4, 0, 0, boot_print_exception);
 610 #include "libguile/backtrace.x"
 611 }
 612
 613 /*
 614   Local Variables:
 615   c-file-style: "gnu"
 616   End:
 617 */