1 /* Printing of backtraces and error messages
2 * Copyright (C) 1996, 1997, 1998, 1999, 2000 Free Software Foundation
4 * This program is free software; you can redistribute it and/or modify
5 * it under the terms of the GNU General Public License as published by
6 * the Free Software Foundation; either version 2, or (at your option)
9 * This program 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
12 * GNU General Public License for more details.
14 * You should have received a copy of the GNU General Public License
15 * along with this software; see the file COPYING. If not, write to
16 * the Free Software Foundation, Inc., 59 Temple Place, Suite 330,
17 * Boston, MA 02111-1307 USA
19 * As a special exception, the Free Software Foundation gives permission
20 * for additional uses of the text contained in its release of GUILE.
22 * The exception is that, if you link the GUILE library with other files
23 * to produce an executable, this does not by itself cause the
24 * resulting executable to be covered by the GNU General Public License.
25 * Your use of that executable is in no way restricted on account of
26 * linking the GUILE library code into it.
28 * This exception does not however invalidate any other reasons why
29 * the executable file might be covered by the GNU General Public License.
31 * This exception applies only to the code released by the
32 * Free Software Foundation under the name GUILE. If you copy
33 * code from other Free Software Foundation releases into a copy of
34 * GUILE, as the General Public License permits, the exception does
35 * not apply to the code that you add in this way. To avoid misleading
36 * anyone as to the status of such modified files, you must delete
37 * this exception notice from them.
39 * If you write modifications of your own for GUILE, it is your choice
40 * whether to permit this exception to apply to your modifications.
41 * If you do not wish that, delete this exception notice.
43 * The author can be reached at djurfeldt@nada.kth.se
44 * Mikael Djurfeldt, SANS/NADA KTH, 10044 STOCKHOLM, SWEDEN */
46 /* Software engineering face-lift by Greg J. Badros, 11-Dec-1999,
47 gjb@cs.washington.edu, http://www.cs.washington.edu/homes/gjb */
52 #include "libguile/_scm.h"
58 #include "libguile/stacks.h"
59 #include "libguile/srcprop.h"
60 #include "libguile/struct.h"
61 #include "libguile/strports.h"
62 #include "libguile/throw.h"
63 #include "libguile/fluids.h"
64 #include "libguile/ports.h"
65 #include "libguile/strings.h"
67 #include "libguile/validate.h"
68 #include "libguile/backtrace.h"
70 /* {Error reporting and backtraces}
71 * (A first approximation.)
73 * Note that these functions shouldn't generate errors themselves.
78 #define SCM_ASSERT(_cond, _arg, _pos, _subr) \
83 SCM scm_the_last_stack_fluid
;
86 display_header (SCM source
, SCM port
)
88 if (SCM_MEMOIZEDP (source
))
90 SCM fname
= scm_source_property (source
, scm_sym_filename
);
91 SCM line
= scm_source_property (source
, scm_sym_line
);
92 SCM col
= scm_source_property (source
, scm_sym_column
);
94 /* Dirk:FIXME:: Maybe we should store the _port_ rather than the
95 * filename with the source properties? Then we could in case of
96 * non-file ports give at least some more details than just
97 * "<unnamed port>". */
98 if (SCM_STRINGP (fname
))
99 scm_prin1 (fname
, port
, 0);
101 scm_puts ("<unnamed port>", port
);
103 if (!SCM_FALSEP (line
) && !SCM_FALSEP (col
))
105 scm_putc (':', port
);
106 scm_intprint (SCM_INUM (line
) + 1, 10, port
);
107 scm_putc (':', port
);
108 scm_intprint (SCM_INUM (col
) + 1, 10, port
);
112 scm_puts ("ERROR", port
);
113 scm_puts (": ", port
);
118 scm_display_error_message (SCM message
, SCM args
, SCM port
)
120 if (SCM_STRINGP (message
) && !SCM_FALSEP (scm_list_p (args
)))
122 scm_simple_format (port
, message
, args
);
127 scm_display (message
, port
);
133 display_expression (SCM frame
,SCM pname
,SCM source
,SCM port
)
135 SCM print_state
= scm_make_print_state ();
136 scm_print_state
*pstate
= SCM_PRINT_STATE (print_state
);
137 pstate
->writingp
= 0;
141 if (SCM_SYMBOLP (pname
) || SCM_STRINGP (pname
))
143 if (SCM_FRAMEP (frame
)
144 && SCM_FRAME_EVAL_ARGS_P (frame
))
145 scm_puts ("While evaluating arguments to ", port
);
147 scm_puts ("In procedure ", port
);
148 scm_iprin1 (pname
, port
, pstate
);
149 if (SCM_MEMOIZEDP (source
))
151 scm_puts (" in expression ", port
);
152 pstate
->writingp
= 1;
153 scm_iprin1 (scm_unmemoize (source
), port
, pstate
);
156 else if (SCM_NIMP (source
))
158 scm_puts ("In expression ", port
);
159 pstate
->writingp
= 1;
160 scm_iprin1 (scm_unmemoize (source
), port
, pstate
);
162 scm_puts (":\n", port
);
163 scm_free_print_state (print_state
);
166 struct display_error_args
{
176 display_error_body (struct display_error_args
*a
)
178 SCM current_frame
= SCM_BOOL_F
;
179 SCM source
= SCM_BOOL_F
;
180 SCM prev_frame
= SCM_BOOL_F
;
184 && SCM_STACKP (a
->stack
)
185 && SCM_STACK_LENGTH (a
->stack
) > 0)
187 current_frame
= scm_stack_ref (a
->stack
, SCM_INUM0
);
188 source
= SCM_FRAME_SOURCE (current_frame
);
189 prev_frame
= SCM_FRAME_PREV (current_frame
);
190 if (!SCM_MEMOIZEDP (source
) && !SCM_FALSEP (prev_frame
))
191 source
= SCM_FRAME_SOURCE (prev_frame
);
192 if (!SCM_SYMBOLP (pname
) && !SCM_STRINGP (pname
) && SCM_FRAME_PROC_P (current_frame
)
193 && SCM_EQ_P (scm_procedure_p (SCM_FRAME_PROC (current_frame
)), SCM_BOOL_T
))
194 pname
= scm_procedure_name (SCM_FRAME_PROC (current_frame
));
196 if (SCM_SYMBOLP (pname
) || SCM_STRINGP (pname
) || SCM_MEMOIZEDP (source
))
198 display_header (source
, a
->port
);
199 display_expression (current_frame
, pname
, source
, a
->port
);
201 display_header (source
, a
->port
);
202 scm_display_error_message (a
->message
, a
->args
, a
->port
);
203 return SCM_UNSPECIFIED
;
206 struct display_error_handler_data
{
211 /* This is the exception handler for error reporting routines.
212 Note that it is very important that this handler *doesn't* try to
213 print more than the error tag, since the error very probably is
214 caused by an erroneous print call-back routine. If we would
215 try to print all objects, we would enter an infinite loop. */
217 display_error_handler (struct display_error_handler_data
*data
,
220 SCM print_state
= scm_make_print_state ();
221 scm_puts ("\nException during displaying of ", data
->port
);
222 scm_puts (data
->mode
, data
->port
);
223 scm_puts (": ", data
->port
);
224 scm_iprin1 (tag
, data
->port
, SCM_PRINT_STATE (print_state
));
225 scm_putc ('\n', data
->port
);
226 return SCM_UNSPECIFIED
;
230 /* The function scm_i_display_error prints out a detailed error message. This
231 * function will be called directly within libguile to signal error messages.
232 * No parameter checks will be performed by scm_i_display_error. Thus, User
233 * code should rather use the function scm_display_error.
236 scm_i_display_error (SCM stack
, SCM port
, SCM subr
, SCM message
, SCM args
, SCM rest
)
238 struct display_error_args a
;
239 struct display_error_handler_data data
;
248 scm_internal_catch (SCM_BOOL_T
,
249 (scm_catch_body_t
) display_error_body
, &a
,
250 (scm_catch_handler_t
) display_error_handler
, &data
);
254 SCM_DEFINE (scm_display_error
, "display-error", 6, 0, 0,
255 (SCM stack
, SCM port
, SCM subr
, SCM message
, SCM args
, SCM rest
),
256 "Display an error message to the output port @var{port}.\n"
257 "@var{stack} is the saved stack for the error, @var{subr} is\n"
258 "the name of the procedure in which the error occured and\n"
259 "@var{message} is the actual error message, which may contain\n"
260 "formatting instructions. These will format the arguments in\n"
261 "the list @var{args} accordingly. @var{rest} is currently\n"
263 #define FUNC_NAME s_scm_display_error
265 SCM_VALIDATE_OUTPUT_PORT (2, port
);
267 scm_i_display_error (stack
, port
, subr
, message
, args
, rest
);
269 return SCM_UNSPECIFIED
;
279 static int n_print_params
= 9;
280 static print_params_t default_print_params
[] = {
284 { 1, 4 }, { 1, 3 }, { 1, 2 }
286 static print_params_t
*print_params
= default_print_params
;
289 SCM_DEFINE (scm_set_print_params_x
, "set-print-params!", 1, 0, 0,
291 "Set the print parameters to the values from @var{params}.\n"
292 "@var{params} must be a list of two-element lists which must\n"
293 "hold two integer values.")
294 #define FUNC_NAME s_scm_set_print_params_x
299 print_params_t
*new_params
;
301 SCM_VALIDATE_NONEMPTYLIST_COPYLEN (2, params
, n
);
302 for (ls
= params
; SCM_NNULLP (ls
); ls
= SCM_CDR (ls
))
303 SCM_ASSERT (scm_ilength (SCM_CAR (params
)) == 2
304 && SCM_INUMP (SCM_CAAR (ls
))
305 && SCM_INUM (SCM_CAAR (ls
)) >= 0
306 && SCM_INUMP (SCM_CADAR (ls
))
307 && SCM_INUM (SCM_CADAR (ls
)) >= 0,
310 s_scm_set_print_params_x
);
311 new_params
= scm_must_malloc (n
* sizeof (print_params_t
),
313 if (print_params
!= default_print_params
)
314 scm_must_free (print_params
);
315 print_params
= new_params
;
316 for (i
= 0; i
< n
; ++i
)
318 print_params
[i
].level
= SCM_INUM (SCM_CAAR (params
));
319 print_params
[i
].length
= SCM_INUM (SCM_CADAR (params
));
320 params
= SCM_CDR (params
);
323 return SCM_UNSPECIFIED
;
329 indent (int n
, SCM port
)
332 for (i
= 0; i
< n
; ++i
)
333 scm_putc (' ', port
);
337 display_frame_expr (char *hdr
,SCM exp
,char *tlr
,int indentation
,SCM sport
,SCM port
,scm_print_state
*pstate
)
341 scm_ptob_descriptor
*ptob
= scm_ptobs
+ SCM_PTOBNUM (sport
);
344 pstate
->length
= print_params
[i
].length
;
345 ptob
->seek (sport
, 0, SEEK_SET
);
348 pstate
->level
= print_params
[i
].level
- 1;
349 scm_iprlist (hdr
, exp
, tlr
[0], sport
, pstate
);
350 scm_puts (&tlr
[1], sport
);
354 pstate
->level
= print_params
[i
].level
;
355 scm_iprin1 (exp
, sport
, pstate
);
358 n
= ptob
->seek (sport
, 0, SEEK_CUR
);
361 while (indentation
+ n
> SCM_BACKTRACE_WIDTH
&& i
< n_print_params
);
362 ptob
->truncate (sport
, n
);
363 string
= scm_strport_to_string (sport
);
364 /* Remove control characters */
365 for (i
= 0; i
< n
; ++i
)
366 if (iscntrl (SCM_STRING_CHARS (string
)[i
]))
367 SCM_STRING_CHARS (string
)[i
] = ' ';
369 if (indentation
+ n
> SCM_BACKTRACE_WIDTH
)
371 n
= SCM_BACKTRACE_WIDTH
- indentation
;
372 SCM_STRING_CHARS (string
)[n
- 1] = '$';
375 scm_lfwrite (SCM_STRING_CHARS (string
), n
, port
);
379 display_application (SCM frame
,int indentation
,SCM sport
,SCM port
,scm_print_state
*pstate
)
381 SCM proc
= SCM_FRAME_PROC (frame
);
382 SCM name
= (SCM_NFALSEP (scm_procedure_p (proc
))
383 ? scm_procedure_name (proc
)
385 display_frame_expr ("[",
386 scm_cons (SCM_NFALSEP (name
) ? name
: proc
,
387 SCM_FRAME_ARGS (frame
)),
388 SCM_FRAME_EVAL_ARGS_P (frame
) ? " ..." : "]",
395 SCM_DEFINE (scm_display_application
, "display-application", 1, 2, 0,
396 (SCM frame
, SCM port
, SCM indent
),
397 "Display a procedure application @var{frame} to the output port\n"
398 "@var{port}. @var{indent} specifies the indentation of the\n"
400 #define FUNC_NAME s_scm_display_application
402 SCM_VALIDATE_FRAME (1,frame
);
403 if (SCM_UNBNDP (port
))
406 SCM_VALIDATE_OPOUTPORT (2,port
);
407 if (SCM_UNBNDP (indent
))
410 SCM_VALIDATE_INUM (3,indent
);
412 if (SCM_FRAME_PROC_P (frame
))
413 /* Display an application. */
415 SCM sport
, print_state
;
416 scm_print_state
*pstate
;
418 /* Create a string port used for adaptation of printing parameters. */
419 sport
= scm_mkstrport (SCM_INUM0
,
420 scm_make_string (SCM_MAKINUM (240),
425 /* Create a print state for printing of frames. */
426 print_state
= scm_make_print_state ();
427 pstate
= SCM_PRINT_STATE (print_state
);
428 pstate
->writingp
= 1;
431 display_application (frame
, SCM_INUM (indent
), sport
, port
, pstate
);
440 display_frame (SCM frame
,int nfield
,int indentation
,SCM sport
,SCM port
,scm_print_state
*pstate
)
444 /* Announce missing frames? */
445 if (!SCM_BACKWARDS_P
&& SCM_FRAME_OVERFLOW_P (frame
))
447 indent (nfield
+ 1 + indentation
, port
);
448 scm_puts ("...\n", port
);
451 /* Check size of frame number. */
452 n
= SCM_FRAME_NUMBER (frame
);
453 for (i
= 0, j
= n
; j
> 0; ++i
) j
/= 10;
455 /* Number indentation. */
456 indent (nfield
- (i
? i
: 1), port
);
459 scm_iprin1 (SCM_MAKINUM (n
), port
, pstate
);
461 /* Real frame marker */
462 scm_putc (SCM_FRAME_REAL_P (frame
) ? '*' : ' ', port
);
465 indent (indentation
, port
);
467 if (SCM_FRAME_PROC_P (frame
))
468 /* Display an application. */
469 display_application (frame
, nfield
+ 1 + indentation
, sport
, port
, pstate
);
471 /* Display a special form. */
473 SCM source
= SCM_FRAME_SOURCE (frame
);
474 SCM copy
= (SCM_CONSP (source
)
475 ? scm_source_property (source
, scm_sym_copy
)
477 SCM umcopy
= (SCM_MEMOIZEDP (source
)
478 ? scm_unmemoize (source
)
480 display_frame_expr ("(",
481 SCM_CONSP (copy
) ? copy
: umcopy
,
483 nfield
+ 1 + indentation
,
488 scm_putc ('\n', port
);
490 /* Announce missing frames? */
491 if (SCM_BACKWARDS_P
&& SCM_FRAME_OVERFLOW_P (frame
))
493 indent (nfield
+ 1 + indentation
, port
);
494 scm_puts ("...\n", port
);
498 struct display_backtrace_args
{
506 display_backtrace_body(struct display_backtrace_args
*a
)
507 #define FUNC_NAME "display_backtrace_body"
509 int n_frames
, beg
, end
, n
, i
, j
;
510 int nfield
, indent_p
, indentation
;
511 SCM frame
, sport
, print_state
;
512 scm_print_state
*pstate
;
514 a
->port
= SCM_COERCE_OUTPORT (a
->port
);
516 /* Argument checking and extraction. */
517 SCM_ASSERT (SCM_STACKP (a
->stack
),
520 s_display_backtrace
);
521 SCM_ASSERT (SCM_OPOUTPORTP (a
->port
),
524 s_display_backtrace
);
525 n_frames
= SCM_INUM (scm_stack_length (a
->stack
));
526 n
= SCM_INUMP (a
->depth
) ? SCM_INUM (a
->depth
) : SCM_BACKTRACE_DEPTH
;
529 beg
= SCM_INUMP (a
->first
) ? SCM_INUM (a
->first
) : 0;
537 if (SCM_INUMP (a
->first
))
539 beg
= SCM_INUM (a
->first
);
553 SCM_ASSERT (beg
>= 0 && beg
< n_frames
, a
->first
, SCM_ARG3
, s_display_backtrace
);
554 SCM_ASSERT (n
> 0, a
->depth
, SCM_ARG4
, s_display_backtrace
);
556 /* Create a string port used for adaptation of printing parameters. */
557 sport
= scm_mkstrport (SCM_INUM0
,
558 scm_make_string (SCM_MAKINUM (240), SCM_UNDEFINED
),
562 /* Create a print state for printing of frames. */
563 print_state
= scm_make_print_state ();
564 pstate
= SCM_PRINT_STATE (print_state
);
565 pstate
->writingp
= 1;
568 /* First find out if it's reasonable to do indentation. */
574 frame
= scm_stack_ref (a
->stack
, SCM_MAKINUM (beg
));
575 for (i
= 0, j
= 0; i
< n
; ++i
)
577 if (SCM_FRAME_REAL_P (frame
))
579 if (j
> SCM_BACKTRACE_INDENT
)
584 frame
= (SCM_BACKWARDS_P
585 ? SCM_FRAME_PREV (frame
)
586 : SCM_FRAME_NEXT (frame
));
590 /* Determine size of frame number field. */
591 j
= SCM_FRAME_NUMBER (scm_stack_ref (a
->stack
, SCM_MAKINUM (end
)));
592 for (i
= 0; j
> 0; ++i
) j
/= 10;
596 frame
= scm_stack_ref (a
->stack
, SCM_MAKINUM (beg
));
598 display_frame (frame
, nfield
, indentation
, sport
, a
->port
, pstate
);
599 for (i
= 1; i
< n
; ++i
)
601 if (indent_p
&& SCM_FRAME_EVAL_ARGS_P (frame
))
603 frame
= SCM_BACKWARDS_P
? SCM_FRAME_PREV (frame
) : SCM_FRAME_NEXT (frame
);
604 display_frame (frame
, nfield
, indentation
, sport
, a
->port
, pstate
);
607 scm_remember_upto_here_1 (print_state
);
609 return SCM_UNSPECIFIED
;
613 SCM_DEFINE (scm_display_backtrace
, "display-backtrace", 2, 2, 0,
614 (SCM stack
, SCM port
, SCM first
, SCM depth
),
615 "Display a backtrace to the output port @var{port}. @var{stack}\n"
616 "is the stack to take the backtrace from, @var{first} specifies\n"
617 "where in the stack to start and @var{depth} how much frames\n"
618 "to display. Both @var{first} and @var{depth} can be @code{#f},\n"
619 "which means that default values will be used.")
620 #define FUNC_NAME s_scm_display_backtrace
622 struct display_backtrace_args a
;
623 struct display_error_handler_data data
;
628 data
.mode
= "backtrace";
630 scm_internal_catch (SCM_BOOL_T
,
631 (scm_catch_body_t
) display_backtrace_body
, &a
,
632 (scm_catch_handler_t
) display_error_handler
, &data
);
633 return SCM_UNSPECIFIED
;
637 SCM_VCELL (scm_has_shown_backtrace_hint_p_var
, "has-shown-backtrace-hint?");
639 SCM_DEFINE (scm_backtrace
, "backtrace", 0, 0, 0,
641 "Display a backtrace of the stack saved by the last error\n"
642 "to the current output port.")
643 #define FUNC_NAME s_scm_backtrace
645 SCM the_last_stack
= scm_fluid_ref (SCM_CDR (scm_the_last_stack_fluid
));
646 if (SCM_NFALSEP (the_last_stack
))
648 scm_newline (scm_cur_outp
);
649 scm_puts ("Backtrace:\n", scm_cur_outp
);
650 scm_display_backtrace (the_last_stack
,
654 scm_newline (scm_cur_outp
);
655 if (SCM_FALSEP (SCM_CDR (scm_has_shown_backtrace_hint_p_var
))
658 scm_puts ("Type \"(debug-enable 'backtrace)\" if you would like "
660 "automatically if an error occurs in the future.\n",
662 SCM_SETCDR (scm_has_shown_backtrace_hint_p_var
, SCM_BOOL_T
);
667 scm_puts ("No backtrace available.\n", scm_cur_outp
);
669 return SCM_UNSPECIFIED
;
676 scm_init_backtrace ()
678 SCM f
= scm_make_fluid ();
679 scm_the_last_stack_fluid
= scm_sysintern ("the-last-stack", f
);
681 #ifndef SCM_MAGIC_SNARFER
682 #include "libguile/backtrace.x"