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_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   SCM proc = scm_frame_procedure (frame);
 266   SCM name = (scm_is_true (scm_procedure_p (proc))
 267               ? scm_procedure_name (proc)
 268               : SCM_BOOL_F);
 269   display_frame_expr ("[",
 270                       scm_cons (scm_is_true (name) ? name : proc,
 271                                 scm_frame_arguments (frame)),
 272                       "]",
 273                       indentation,
 274                       sport,
 275                       port,
 276                       pstate);
 277 }
 278
 279 SCM_DEFINE (scm_display_application, "display-application", 1, 2, 0,
 280            (SCM frame, SCM port, SCM indent),
 281             "Display a procedure application @var{frame} to the output port\n"
 282             "@var{port}. @var{indent} specifies the indentation of the\n"
 283             "output.")
 284 #define FUNC_NAME s_scm_display_application
 285 {
 286   SCM_VALIDATE_FRAME (1, frame);
 287   if (SCM_UNBNDP (port))
 288     port = scm_current_output_port ();
 289   else
 290     SCM_VALIDATE_OPOUTPORT (2, port);
 291   if (SCM_UNBNDP (indent))
 292     indent = SCM_INUM0;
 293
 294   /* Display an application. */
 295   {
 296     SCM sport, print_state;
 297     scm_print_state *pstate;
 298
 299     /* Create a string port used for adaptation of printing parameters. */
 300     sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 301                            SCM_OPN | SCM_WRTNG,
 302                            FUNC_NAME);
 303
 304     /* Create a print state for printing of frames. */
 305     print_state = scm_make_print_state ();
 306     pstate = SCM_PRINT_STATE (print_state);
 307     pstate->writingp = 1;
 308     pstate->fancyp = 1;
 309
 310     display_application (frame, scm_to_int (indent), sport, port, pstate);
 311     return SCM_BOOL_T;
 312   }
 313 }
 314 #undef FUNC_NAME
 315
 316 SCM_SYMBOL (sym_base, "base");
 317
 318 static void
 319 display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
 320 {
 321   SCM source = scm_frame_source (frame);
 322   *file = *line = SCM_BOOL_F;
 323   if (scm_is_pair (source)
 324       && scm_is_pair (scm_cdr (source))
 325       && scm_is_pair (scm_cddr (source))
 326       && !scm_is_pair (scm_cdddr (source)))
 327     {
 328       /* (addr . (filename . (line . column))), from vm compilation */
 329       *file = scm_cadr (source);
 330       *line = scm_caddr (source);
 331     }
 332 }
 333
 334 static void
 335 display_backtrace_file (frame, last_file, port, pstate)
 336      SCM frame;
 337      SCM *last_file;
 338      SCM port;
 339      scm_print_state *pstate;
 340 {
 341   SCM file, line;
 342
 343   display_backtrace_get_file_line (frame, &file, &line);
 344
 345   if (scm_is_true (scm_equal_p (file, *last_file)))
 346     return;
 347
 348   *last_file = file;
 349
 350   scm_puts_unlocked ("In ", port);
 351   if (scm_is_false (file))
 352     if (scm_is_false (line))
 353       scm_puts_unlocked ("unknown file", port);
 354     else
 355       scm_puts_unlocked ("current input", port);
 356   else
 357     {
 358       pstate->writingp = 0;
 359       scm_iprin1 (file, port, pstate);
 360       pstate->writingp = 1;
 361     }
 362   scm_puts_unlocked (":\n", port);
 363 }
 364
 365 static void
 366 display_backtrace_file_and_line (SCM frame, SCM port, scm_print_state *pstate)
 367 {
 368   SCM file, line;
 369
 370   display_backtrace_get_file_line (frame, &file, &line);
 371
 372   if (scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 373     {
 374       if (scm_is_false (file))
 375         {
 376           if (scm_is_false (line))
 377             scm_putc_unlocked ('?', port);
 378           else
 379             scm_puts_unlocked ("<stdin>", port);
 380         }
 381       else
 382         {
 383           pstate -> writingp = 0;
 384 #ifdef HAVE_POSIX
 385           scm_iprin1 ((scm_is_string (file)?
 386                        scm_basename (file, SCM_UNDEFINED) : file),
 387                       port, pstate);
 388 #else
 389           scm_iprin1 (file, port, pstate);
 390 #endif
 391           pstate -> writingp = 1;
 392         }
 393
 394       scm_putc_unlocked (':', port);
 395     }
 396   else if (scm_is_true (line))
 397     {
 398       int i, j=0;
 399       for (i = scm_to_int (line)+1; i > 0; i = i/10, j++)
 400         ;
 401       indent (4-j, port);
 402     }
 403
 404   if (scm_is_false (line))
 405     scm_puts_unlocked ("   ?", port);
 406   else
 407     scm_intprint (scm_to_int (line) + 1, 10, port);
 408   scm_puts_unlocked (": ", port);
 409 }
 410
 411 static void
 412 display_frame (SCM frame, int n, int nfield, int indentation,
 413                SCM sport, SCM port, scm_print_state *pstate)
 414 {
 415   int i, j;
 416
 417   /* display file name and line number */
 418   if (scm_is_true (SCM_PACK (SCM_SHOW_FILE_NAME)))
 419     display_backtrace_file_and_line (frame, port, pstate);
 420
 421   /* Check size of frame number. */
 422   for (i = 0, j = n; j > 0; ++i) j /= 10;
 423
 424   /* Number indentation. */
 425   indent (nfield - (i ? i : 1), port);
 426
 427   /* Frame number. */
 428   scm_iprin1 (scm_from_int (n), port, pstate);
 429
 430   /* Indentation. */
 431   indent (indentation, port);
 432
 433   /* Display an application. */
 434   display_application (frame, nfield + 1 + indentation, sport, port, pstate);
 435   scm_putc_unlocked ('\n', port);
 436 }
 437
 438 struct display_backtrace_args {
 439   SCM stack;
 440   SCM port;
 441   SCM first;
 442   SCM depth;
 443   SCM highlight_objects;
 444 };
 445
 446 static SCM
 447 display_backtrace_body (struct display_backtrace_args *a)
 448 #define FUNC_NAME "display_backtrace_body"
 449 {
 450   int n_frames, beg, end, n, i, j;
 451   int nfield, indentation;
 452   SCM frame, sport, print_state;
 453   SCM last_file;
 454   scm_print_state *pstate;
 455
 456   a->port = SCM_COERCE_OUTPORT (a->port);
 457
 458   /* Argument checking and extraction. */
 459   SCM_VALIDATE_STACK (1, a->stack);
 460   SCM_VALIDATE_OPOUTPORT (2, a->port);
 461   n_frames = scm_to_int (scm_stack_length (a->stack));
 462   n = scm_is_integer (a->depth) ? scm_to_int (a->depth) : SCM_BACKTRACE_DEPTH;
 463   if (SCM_BACKWARDS_P)
 464     {
 465       beg = scm_is_integer (a->first) ? scm_to_int (a->first) : 0;
 466       end = beg + n - 1;
 467       if (end >= n_frames)
 468         end = n_frames - 1;
 469       n = end - beg + 1;
 470     }
 471   else
 472     {
 473       if (scm_is_integer (a->first))
 474         {
 475           beg = scm_to_int (a->first);
 476           end = beg - n + 1;
 477           if (end < 0)
 478             end = 0;
 479         }
 480       else
 481         {
 482           beg = n - 1;
 483           end = 0;
 484           if (beg >= n_frames)
 485             beg = n_frames - 1;
 486         }
 487       n = beg - end + 1;
 488     }
 489   SCM_ASSERT (beg >= 0 && beg < n_frames, a->first, SCM_ARG3, s_display_backtrace);
 490   SCM_ASSERT (n > 0, a->depth, SCM_ARG4, s_display_backtrace);
 491
 492   /* Create a string port used for adaptation of printing parameters. */
 493   sport = scm_mkstrport (SCM_INUM0, SCM_BOOL_F,
 494                          SCM_OPN | SCM_WRTNG,
 495                          FUNC_NAME);
 496
 497   /* Create a print state for printing of frames. */
 498   print_state = scm_make_print_state ();
 499   pstate = SCM_PRINT_STATE (print_state);
 500   pstate->writingp = 1;
 501   pstate->fancyp = 1;
 502   pstate->highlight_objects = a->highlight_objects;
 503
 504   /* Determine size of frame number field. */
 505   j = end;
 506   for (i = 0; j > 0; ++i) j /= 10;
 507   nfield = i ? i : 1;
 508
 509   /* Print frames. */
 510   indentation = 1;
 511   last_file = SCM_UNDEFINED;
 512   if (SCM_BACKWARDS_P)
 513     end++;
 514   else
 515     end--;
 516   for (i = beg; i != end; SCM_BACKWARDS_P ? ++i : --i)
 517     {
 518       frame = scm_stack_ref (a->stack, scm_from_int (i));
 519       if (!scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
 520         display_backtrace_file (frame, &last_file, a->port, pstate);
 521       display_frame (frame, i, nfield, indentation, sport, a->port, pstate);
 522     }
 523
 524   scm_remember_upto_here_1 (print_state);
 525
 526   return SCM_UNSPECIFIED;
 527 }
 528 #undef FUNC_NAME
 529
 530 static SCM
 531 error_during_backtrace (void *data, SCM tag, SCM throw_args)
 532 {
 533   SCM port = SCM_PACK_POINTER (data);
 534
 535   scm_puts_unlocked ("Exception thrown while printing backtrace:\n", port);
 536   scm_print_exception (port, SCM_BOOL_F, tag, throw_args);
 537
 538   return SCM_UNSPECIFIED;
 539 }
 540
 541
 542 SCM_DEFINE (scm_display_backtrace_with_highlights, "display-backtrace", 2, 3, 0,
 543             (SCM stack, SCM port, SCM first, SCM depth, SCM highlights),
 544             "Display a backtrace to the output port @var{port}.  @var{stack}\n"
 545             "is the stack to take the backtrace from, @var{first} specifies\n"
 546             "where in the stack to start and @var{depth} how many frames\n"
 547             "to display.  @var{first} and @var{depth} can be @code{#f},\n"
 548             "which means that default values will be used.\n"
 549             "If @var{highlights} is given it should be a list; the elements\n"
 550             "of this list will be highlighted wherever they appear in the\n"
 551             "backtrace.")
 552 #define FUNC_NAME s_scm_display_backtrace_with_highlights
 553 {
 554   struct display_backtrace_args a;
 555   a.stack = stack;
 556   a.port  = port;
 557   a.first = first;
 558   a.depth = depth;
 559   if (SCM_UNBNDP (highlights))
 560     a.highlight_objects = SCM_EOL;
 561   else
 562     a.highlight_objects = highlights;
 563
 564   scm_internal_catch (SCM_BOOL_T,
 565                       (scm_t_catch_body) display_backtrace_body, &a,
 566                       (scm_t_catch_handler) error_during_backtrace, SCM_UNPACK_POINTER (port));
 567
 568   return SCM_UNSPECIFIED;
 569 }
 570 #undef FUNC_NAME
 571
 572 SCM
 573 scm_display_backtrace (SCM stack, SCM port, SCM first, SCM depth)
 574 {
 575   return scm_display_backtrace_with_highlights (stack, port, first, depth,
 576                                                 SCM_EOL);
 577 }
 578
 579 SCM_VARIABLE (scm_has_shown_backtrace_hint_p_var, "has-shown-backtrace-hint?");
 580
 581 SCM_DEFINE (scm_backtrace_with_highlights, "backtrace", 0, 1, 0,
 582             (SCM highlights),
 583             "Display a backtrace of the current stack to the current\n"
 584             "output port.  If @var{highlights} is given, it should be\n"
 585             "a list; the elements of this list will be highlighted\n"
 586             "wherever they appear in the backtrace.")
 587 #define FUNC_NAME s_scm_backtrace_with_highlights
 588 {
 589   SCM port = scm_current_output_port ();
 590   SCM stack = scm_make_stack (SCM_BOOL_T, SCM_EOL);
 591
 592   if (SCM_UNBNDP (highlights))
 593     highlights = SCM_EOL;
 594
 595   scm_newline (port);
 596   scm_puts_unlocked ("Backtrace:\n", port);
 597   scm_display_backtrace_with_highlights (stack, port, SCM_BOOL_F, SCM_BOOL_F,
 598                                          highlights);
 599   scm_newline (port);
 600
 601   return SCM_UNSPECIFIED;
 602 }
 603 #undef FUNC_NAME
 604
 605 SCM
 606 scm_backtrace (void)
 607 {
 608   return scm_backtrace_with_highlights (SCM_EOL);
 609 }
 610
 611 \f
 612
 613 void
 614 scm_init_backtrace ()
 615 {
 616   scm_c_define_gsubr ("print-exception", 4, 0, 0, boot_print_exception);
 617 #include "libguile/backtrace.x"
 618 }
 619
 620 /*
 621   Local Variables:
 622   c-file-style: "gnu"
 623   End:
 624 */