1 /* Printing of backtraces and error messages
2 * Copyright (C) 1996,1997,1998,1999,2000,2001, 2003, 2004, 2006 Free Software Foundation
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.
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.
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
27 #include "libguile/_scm.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"
46 #include "libguile/validate.h"
47 #include "libguile/lang.h"
48 #include "libguile/backtrace.h"
49 #include "libguile/filesys.h"
51 /* {Error reporting and backtraces}
53 * Note that these functions shouldn't generate errors themselves.
56 /* Print parameters for error messages. */
58 #define DISPLAY_ERROR_MESSAGE_MAX_LEVEL 7
59 #define DISPLAY_ERROR_MESSAGE_MAX_LENGTH 10
61 /* Print parameters for failing expressions in error messages.
62 * (See also `print_params' below for backtrace print parameters.)
65 #define DISPLAY_EXPRESSION_MAX_LEVEL 2
66 #define DISPLAY_EXPRESSION_MAX_LENGTH 3
69 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
73 SCM scm_the_last_stack_fluid_var;
76 display_header (SCM source, SCM port)
78 if (SCM_MEMOIZEDP (source))
80 SCM fname = scm_source_property (source, scm_sym_filename);
81 SCM line = scm_source_property (source, scm_sym_line);
82 SCM col = scm_source_property (source, scm_sym_column);
84 /* Dirk:FIXME:: Maybe we should store the _port_ rather than the
85 * filename with the source properties? Then we could in case of
86 * non-file ports give at least some more details than just
87 * "<unnamed port>". */
88 if (scm_is_true (fname))
89 scm_prin1 (fname, port, 0);
91 scm_puts ("<unnamed port>", port);
93 if (scm_is_true (line) && scm_is_true (col))
96 scm_intprint (scm_to_long (line) + 1, 10, port);
98 scm_intprint (scm_to_long (col) + 1, 10, port);
102 scm_puts ("ERROR", port);
103 scm_puts (": ", port);
107 struct display_error_message_data {
111 scm_print_state *pstate;
118 display_error_message (struct display_error_message_data *d)
120 if (scm_is_string (d->message) && scm_is_true (scm_list_p (d->args)))
121 scm_simple_format (d->port, d->message, d->args);
123 scm_display (d->message, d->port);
124 scm_newline (d->port);
125 return SCM_UNSPECIFIED;
129 before_display_error_message (struct display_error_message_data *d)
131 scm_print_state *pstate = d->pstate;
132 d->old_fancyp = pstate->fancyp;
133 d->old_level = pstate->level;
134 d->old_length = pstate->length;
136 pstate->level = DISPLAY_ERROR_MESSAGE_MAX_LEVEL;
137 pstate->length = DISPLAY_ERROR_MESSAGE_MAX_LENGTH;
141 after_display_error_message (struct display_error_message_data *d)
143 scm_print_state *pstate = d->pstate;
144 pstate->fancyp = d->old_fancyp;
145 pstate->level = d->old_level;
146 pstate->length = d->old_length;
150 scm_display_error_message (SCM message, SCM args, SCM port)
152 struct display_error_message_data d;
154 scm_print_state *pstate;
156 port = scm_i_port_with_print_state (port, SCM_UNDEFINED);
157 print_state = SCM_PORT_WITH_PS_PS (port);
158 pstate = SCM_PRINT_STATE (print_state);
164 scm_internal_dynamic_wind ((scm_t_guard) before_display_error_message,
165 (scm_t_inner) display_error_message,
166 (scm_t_guard) after_display_error_message,
172 display_expression (SCM frame, SCM pname, SCM source, SCM port)
174 SCM print_state = scm_make_print_state ();
175 scm_print_state *pstate = SCM_PRINT_STATE (print_state);
176 pstate->writingp = 0;
178 pstate->level = DISPLAY_EXPRESSION_MAX_LEVEL;
179 pstate->length = DISPLAY_EXPRESSION_MAX_LENGTH;
180 if (scm_is_symbol (pname) || scm_is_string (pname))
182 if (SCM_FRAMEP (frame)
183 && SCM_FRAME_EVAL_ARGS_P (frame))
184 scm_puts ("While evaluating arguments to ", port);
186 scm_puts ("In procedure ", port);
187 scm_iprin1 (pname, port, pstate);
188 if (SCM_MEMOIZEDP (source))
190 scm_puts (" in expression ", port);
191 pstate->writingp = 1;
192 scm_iprin1 (scm_i_unmemoize_expr (source), port, pstate);
195 else if (SCM_MEMOIZEDP (source))
197 scm_puts ("In expression ", port);
198 pstate->writingp = 1;
199 scm_iprin1 (scm_i_unmemoize_expr (source), port, pstate);
201 scm_puts (":\n", port);
202 scm_free_print_state (print_state);
205 struct display_error_args {
215 display_error_body (struct display_error_args *a)
217 SCM current_frame = SCM_BOOL_F;
218 SCM source = SCM_BOOL_F;
219 SCM prev_frame = SCM_BOOL_F;
223 && SCM_STACKP (a->stack)
224 && SCM_STACK_LENGTH (a->stack) > 0)
226 current_frame = scm_stack_ref (a->stack, SCM_INUM0);
227 source = SCM_FRAME_SOURCE (current_frame);
228 prev_frame = SCM_FRAME_PREV (current_frame);
229 if (!SCM_MEMOIZEDP (source) && scm_is_true (prev_frame))
230 source = SCM_FRAME_SOURCE (prev_frame);
231 if (!scm_is_symbol (pname)
232 && !scm_is_string (pname)
233 && SCM_FRAME_PROC_P (current_frame)
234 && scm_is_true (scm_procedure_p (SCM_FRAME_PROC (current_frame))))
235 pname = scm_procedure_name (SCM_FRAME_PROC (current_frame));
237 if (scm_is_symbol (pname) || scm_is_string (pname) || SCM_MEMOIZEDP (source))
239 display_header (source, a->port);
240 display_expression (current_frame, pname, source, a->port);
242 display_header (source, a->port);
243 scm_display_error_message (a->message, a->args, a->port);
244 return SCM_UNSPECIFIED;
247 struct display_error_handler_data {
252 /* This is the exception handler for error reporting routines.
253 Note that it is very important that this handler *doesn't* try to
254 print more than the error tag, since the error very probably is
255 caused by an erroneous print call-back routine. If we would
256 try to print all objects, we would enter an infinite loop. */
258 display_error_handler (struct display_error_handler_data *data,
259 SCM tag, SCM args SCM_UNUSED)
261 SCM print_state = scm_make_print_state ();
262 scm_puts ("\nException during displaying of ", data->port);
263 scm_puts (data->mode, data->port);
264 scm_puts (": ", data->port);
265 scm_iprin1 (tag, data->port, SCM_PRINT_STATE (print_state));
266 scm_putc ('\n', data->port);
267 return SCM_UNSPECIFIED;
271 /* The function scm_i_display_error prints out a detailed error message. This
272 * function will be called directly within libguile to signal error messages.
273 * No parameter checks will be performed by scm_i_display_error. Thus, User
274 * code should rather use the function scm_display_error.
277 scm_i_display_error (SCM stack, SCM port, SCM subr, SCM message, SCM args, SCM rest)
279 struct display_error_args a;
280 struct display_error_handler_data data;
289 scm_internal_catch (SCM_BOOL_T,
290 (scm_t_catch_body) display_error_body, &a,
291 (scm_t_catch_handler) display_error_handler, &data);
295 SCM_DEFINE (scm_display_error, "display-error", 6, 0, 0,
296 (SCM stack, SCM port, SCM subr, SCM message, SCM args, SCM rest),
297 "Display an error message to the output port @var{port}.\n"
298 "@var{stack} is the saved stack for the error, @var{subr} is\n"
299 "the name of the procedure in which the error occurred and\n"
300 "@var{message} is the actual error message, which may contain\n"
301 "formatting instructions. These will format the arguments in\n"
302 "the list @var{args} accordingly. @var{rest} is currently\n"
304 #define FUNC_NAME s_scm_display_error
306 SCM_VALIDATE_OUTPUT_PORT (2, port);
308 scm_i_display_error (stack, port, subr, message, args, rest);
310 return SCM_UNSPECIFIED;
320 static int n_print_params = 9;
321 static print_params_t default_print_params[] = {
325 { 1, 4 }, { 1, 3 }, { 1, 2 }
327 static print_params_t *print_params = default_print_params;
330 SCM_DEFINE (scm_set_print_params_x, "set-print-params!", 1, 0, 0,
332 "Set the print parameters to the values from @var{params}.\n"
333 "@var{params} must be a list of two-element lists which must\n"
334 "hold two integer values.")
335 #define FUNC_NAME s_scm_set_print_params_x
340 print_params_t *new_params;
342 SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, params, n);
343 for (ls = params; !SCM_NULL_OR_NIL_P (ls); ls = SCM_CDR (ls))
344 SCM_ASSERT (scm_ilength (SCM_CAR (params)) == 2
345 && scm_is_unsigned_integer (SCM_CAAR (ls), 0, INT_MAX)
346 && scm_is_unsigned_integer (SCM_CADAR (ls), 0, INT_MAX),
349 s_scm_set_print_params_x);
350 new_params = scm_malloc (n * sizeof (print_params_t));
351 if (print_params != default_print_params)
353 print_params = new_params;
354 for (i = 0; i < n; ++i)
356 print_params[i].level = scm_to_int (SCM_CAAR (params));
357 print_params[i].length = scm_to_int (SCM_CADAR (params));
358 params = SCM_CDR (params);
361 return SCM_UNSPECIFIED;
367 indent (int n, SCM port)
370 for (i = 0; i < n; ++i)
371 scm_putc (' ', port);
375 display_frame_expr (char *hdr, SCM exp, char *tlr, int indentation, SCM sport, SCM port, scm_print_state *pstate)
378 scm_t_ptob_descriptor *ptob = scm_ptobs + SCM_PTOBNUM (sport);
381 pstate->length = print_params[i].length;
382 ptob->seek (sport, 0, SEEK_SET);
383 if (scm_is_pair (exp))
385 pstate->level = print_params[i].level - 1;
386 scm_iprlist (hdr, exp, tlr[0], sport, pstate);
387 scm_puts (&tlr[1], sport);
391 pstate->level = print_params[i].level;
392 scm_iprin1 (exp, sport, pstate);
395 n = ptob->seek (sport, 0, SEEK_CUR);
398 while (indentation + n > SCM_BACKTRACE_WIDTH && i < n_print_params);
399 ptob->truncate (sport, n);
401 scm_display (scm_strport_to_string (sport), port);
405 display_application (SCM frame, int indentation, SCM sport, SCM port, scm_print_state *pstate)
407 SCM proc = SCM_FRAME_PROC (frame);
408 SCM name = (scm_is_true (scm_procedure_p (proc))
409 ? scm_procedure_name (proc)
411 display_frame_expr ("[",
412 scm_cons (scm_is_true (name) ? name : proc,
413 SCM_FRAME_ARGS (frame)),
414 SCM_FRAME_EVAL_ARGS_P (frame) ? " ..." : "]",
421 SCM_DEFINE (scm_display_application, "display-application", 1, 2, 0,
422 (SCM frame, SCM port, SCM indent),
423 "Display a procedure application @var{frame} to the output port\n"
424 "@var{port}. @var{indent} specifies the indentation of the\n"
426 #define FUNC_NAME s_scm_display_application
428 SCM_VALIDATE_FRAME (1, frame);
429 if (SCM_UNBNDP (port))
430 port = scm_current_output_port ();
432 SCM_VALIDATE_OPOUTPORT (2, port);
433 if (SCM_UNBNDP (indent))
436 if (SCM_FRAME_PROC_P (frame))
437 /* Display an application. */
439 SCM sport, print_state;
440 scm_print_state *pstate;
442 /* Create a string port used for adaptation of printing parameters. */
443 sport = scm_mkstrport (SCM_INUM0,
444 scm_make_string (scm_from_int (240),
449 /* Create a print state for printing of frames. */
450 print_state = scm_make_print_state ();
451 pstate = SCM_PRINT_STATE (print_state);
452 pstate->writingp = 1;
455 display_application (frame, scm_to_int (indent), sport, port, pstate);
463 SCM_SYMBOL (sym_base, "base");
466 display_backtrace_get_file_line (SCM frame, SCM *file, SCM *line)
468 SCM source = SCM_FRAME_SOURCE (frame);
469 *file = SCM_MEMOIZEDP (source) ? scm_source_property (source, scm_sym_filename) : SCM_BOOL_F;
470 *line = (SCM_MEMOIZEDP (source)) ? scm_source_property (source, scm_sym_line) : SCM_BOOL_F;
474 display_backtrace_file (frame, last_file, port, pstate)
478 scm_print_state *pstate;
482 display_backtrace_get_file_line (frame, &file, &line);
484 if (scm_is_eq (file, *last_file))
489 scm_puts ("In ", port);
490 if (scm_is_false (file))
491 if (scm_is_false (line))
492 scm_puts ("unknown file", port);
494 scm_puts ("current input", port);
497 pstate->writingp = 0;
498 scm_iprin1 (file, port, pstate);
499 pstate->writingp = 1;
501 scm_puts (":\n", port);
505 display_backtrace_file_and_line (SCM frame, SCM port, scm_print_state *pstate)
509 display_backtrace_get_file_line (frame, &file, &line);
511 if (scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
513 if (scm_is_false (file))
515 if (scm_is_false (line))
516 scm_putc ('?', port);
518 scm_puts ("<stdin>", port);
522 pstate -> writingp = 0;
524 scm_iprin1 ((scm_is_string (file)?
525 scm_basename (file, SCM_UNDEFINED) : file),
528 scm_iprin1 (file, port, pstate);
530 pstate -> writingp = 1;
533 scm_putc (':', port);
535 else if (scm_is_true (line))
538 for (i = scm_to_int (line)+1; i > 0; i = i/10, j++)
543 if (scm_is_false (line))
544 scm_puts (" ?", port);
546 scm_intprint (scm_to_int (line) + 1, 10, port);
547 scm_puts (": ", port);
551 display_frame (SCM frame, int nfield, int indentation, SCM sport, SCM port, scm_print_state *pstate)
555 /* Announce missing frames? */
556 if (!SCM_BACKWARDS_P && SCM_FRAME_OVERFLOW_P (frame))
558 indent (nfield + 1 + indentation, port);
559 scm_puts ("...\n", port);
562 /* display file name and line number */
563 if (scm_is_true (SCM_PACK (SCM_SHOW_FILE_NAME)))
564 display_backtrace_file_and_line (frame, port, pstate);
566 /* Check size of frame number. */
567 n = SCM_FRAME_NUMBER (frame);
568 for (i = 0, j = n; j > 0; ++i) j /= 10;
570 /* Number indentation. */
571 indent (nfield - (i ? i : 1), port);
574 scm_iprin1 (scm_from_int (n), port, pstate);
576 /* Real frame marker */
577 scm_putc (SCM_FRAME_REAL_P (frame) ? '*' : ' ', port);
580 indent (indentation, port);
582 if (SCM_FRAME_PROC_P (frame))
583 /* Display an application. */
584 display_application (frame, nfield + 1 + indentation, sport, port, pstate);
586 /* Display a special form. */
588 SCM source = SCM_FRAME_SOURCE (frame);
589 SCM copy = (scm_is_pair (source)
590 ? scm_source_property (source, scm_sym_copy)
592 SCM umcopy = (SCM_MEMOIZEDP (source)
593 ? scm_i_unmemoize_expr (source)
595 display_frame_expr ("(",
596 scm_is_pair (copy) ? copy : umcopy,
598 nfield + 1 + indentation,
603 scm_putc ('\n', port);
605 /* Announce missing frames? */
606 if (SCM_BACKWARDS_P && SCM_FRAME_OVERFLOW_P (frame))
608 indent (nfield + 1 + indentation, port);
609 scm_puts ("...\n", port);
613 struct display_backtrace_args {
618 SCM highlight_objects;
622 display_backtrace_body (struct display_backtrace_args *a)
623 #define FUNC_NAME "display_backtrace_body"
625 int n_frames, beg, end, n, i, j;
626 int nfield, indent_p, indentation;
627 SCM frame, sport, print_state;
629 scm_print_state *pstate;
631 a->port = SCM_COERCE_OUTPORT (a->port);
633 /* Argument checking and extraction. */
634 SCM_VALIDATE_STACK (1, a->stack);
635 SCM_VALIDATE_OPOUTPORT (2, a->port);
636 n_frames = scm_to_int (scm_stack_length (a->stack));
637 n = scm_is_integer (a->depth) ? scm_to_int (a->depth) : SCM_BACKTRACE_DEPTH;
640 beg = scm_is_integer (a->first) ? scm_to_int (a->first) : 0;
648 if (scm_is_integer (a->first))
650 beg = scm_to_int (a->first);
664 SCM_ASSERT (beg >= 0 && beg < n_frames, a->first, SCM_ARG3, s_display_backtrace);
665 SCM_ASSERT (n > 0, a->depth, SCM_ARG4, s_display_backtrace);
667 /* Create a string port used for adaptation of printing parameters. */
668 sport = scm_mkstrport (SCM_INUM0,
669 scm_make_string (scm_from_int (240), SCM_UNDEFINED),
673 /* Create a print state for printing of frames. */
674 print_state = scm_make_print_state ();
675 pstate = SCM_PRINT_STATE (print_state);
676 pstate->writingp = 1;
678 pstate->highlight_objects = a->highlight_objects;
680 /* First find out if it's reasonable to do indentation. */
688 frame = scm_stack_ref (a->stack, scm_from_int (beg));
689 for (i = 0, j = 0; i < n; ++i)
691 if (SCM_FRAME_REAL_P (frame))
693 if (j > SCM_BACKTRACE_INDENT)
698 frame = (SCM_BACKWARDS_P
699 ? SCM_FRAME_PREV (frame)
700 : SCM_FRAME_NEXT (frame));
704 /* Determine size of frame number field. */
705 j = SCM_FRAME_NUMBER (scm_stack_ref (a->stack, scm_from_int (end)));
706 for (i = 0; j > 0; ++i) j /= 10;
710 frame = scm_stack_ref (a->stack, scm_from_int (beg));
712 last_file = SCM_UNDEFINED;
713 for (i = 0; i < n; ++i)
715 if (!scm_is_eq (SCM_PACK (SCM_SHOW_FILE_NAME), sym_base))
716 display_backtrace_file (frame, &last_file, a->port, pstate);
718 display_frame (frame, nfield, indentation, sport, a->port, pstate);
719 if (indent_p && SCM_FRAME_EVAL_ARGS_P (frame))
721 frame = (SCM_BACKWARDS_P ?
722 SCM_FRAME_PREV (frame) : SCM_FRAME_NEXT (frame));
725 scm_remember_upto_here_1 (print_state);
727 return SCM_UNSPECIFIED;
731 SCM_DEFINE (scm_display_backtrace_with_highlights, "display-backtrace", 2, 3, 0,
732 (SCM stack, SCM port, SCM first, SCM depth, SCM highlights),
733 "Display a backtrace to the output port @var{port}. @var{stack}\n"
734 "is the stack to take the backtrace from, @var{first} specifies\n"
735 "where in the stack to start and @var{depth} how much frames\n"
736 "to display. Both @var{first} and @var{depth} can be @code{#f},\n"
737 "which means that default values will be used.\n"
738 "When @var{highlights} is given,\n"
739 "it should be a list and all members of it are highligthed in\n"
741 #define FUNC_NAME s_scm_display_backtrace_with_highlights
743 struct display_backtrace_args a;
744 struct display_error_handler_data data;
749 if (SCM_UNBNDP (highlights))
750 a.highlight_objects = SCM_EOL;
752 a.highlight_objects = highlights;
753 data.mode = "backtrace";
755 scm_internal_catch (SCM_BOOL_T,
756 (scm_t_catch_body) display_backtrace_body, &a,
757 (scm_t_catch_handler) display_error_handler, &data);
758 return SCM_UNSPECIFIED;
763 scm_display_backtrace (SCM stack, SCM port, SCM first, SCM depth)
765 return scm_display_backtrace_with_highlights (stack, port, first, depth,
769 SCM_VARIABLE (scm_has_shown_backtrace_hint_p_var, "has-shown-backtrace-hint?");
771 SCM_DEFINE (scm_backtrace_with_highlights, "backtrace", 0, 1, 0,
773 "Display a backtrace of the stack saved by the last error\n"
774 "to the current output port. When @var{highlights} is given,\n"
775 "it should be a list and all members of it are highligthed in\n"
777 #define FUNC_NAME s_scm_backtrace_with_highlights
779 SCM port = scm_current_output_port ();
781 scm_fluid_ref (SCM_VARIABLE_REF (scm_the_last_stack_fluid_var));
783 if (SCM_UNBNDP (highlights))
784 highlights = SCM_EOL;
786 if (scm_is_true (the_last_stack))
789 scm_puts ("Backtrace:\n", port);
790 scm_display_backtrace_with_highlights (the_last_stack,
796 if (scm_is_false (SCM_VARIABLE_REF (scm_has_shown_backtrace_hint_p_var))
799 scm_puts ("Type \"(debug-enable 'backtrace)\" if you would like "
801 "automatically if an error occurs in the future.\n",
803 SCM_VARIABLE_SET (scm_has_shown_backtrace_hint_p_var, SCM_BOOL_T);
808 scm_puts ("No backtrace available.\n", port);
810 return SCM_UNSPECIFIED;
817 return scm_backtrace_with_highlights (SCM_EOL);
823 scm_init_backtrace ()
825 SCM f = scm_make_fluid ();
826 scm_the_last_stack_fluid_var = scm_c_define ("the-last-stack", f);
828 #include "libguile/backtrace.x"