Commit | Line | Data |
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43d8869b GS |
1 | # |
2 | # Documentation is at the __END__ | |
3 | # | |
4 | ||
5 | package DB; | |
6 | ||
7 | # "private" globals | |
8 | ||
9 | my ($running, $ready, $deep, $usrctxt, $evalarg, | |
10 | @stack, @saved, @skippkg, @clients); | |
11 | my $preeval = {}; | |
12 | my $posteval = {}; | |
13 | my $ineval = {}; | |
14 | ||
15 | #### | |
16 | # | |
17 | # Globals - must be defined at startup so that clients can refer to | |
18 | # them right after a C<require DB;> | |
19 | # | |
20 | #### | |
21 | ||
22 | BEGIN { | |
23 | ||
24 | # these are hardcoded in perl source (some are magical) | |
25 | ||
26 | $DB::sub = ''; # name of current subroutine | |
27 | %DB::sub = (); # "filename:fromline-toline" for every known sub | |
28 | $DB::single = 0; # single-step flag (set it to 1 to enable stops in BEGIN/use) | |
29 | $DB::signal = 0; # signal flag (will cause a stop at the next line) | |
30 | $DB::trace = 0; # are we tracing through subroutine calls? | |
31 | @DB::args = (); # arguments of current subroutine or @ARGV array | |
32 | @DB::dbline = (); # list of lines in currently loaded file | |
33 | %DB::dbline = (); # actions in current file (keyed by line number) | |
34 | @DB::ret = (); # return value of last sub executed in list context | |
35 | $DB::ret = ''; # return value of last sub executed in scalar context | |
36 | ||
37 | # other "public" globals | |
38 | ||
39 | $DB::package = ''; # current package space | |
40 | $DB::filename = ''; # current filename | |
41 | $DB::subname = ''; # currently executing sub (fullly qualified name) | |
42 | $DB::lineno = ''; # current line number | |
43 | ||
44 | $DB::VERSION = $DB::VERSION = '1.0'; | |
45 | ||
46 | # initialize private globals to avoid warnings | |
47 | ||
48 | $running = 1; # are we running, or are we stopped? | |
49 | @stack = (0); | |
50 | @clients = (); | |
51 | $deep = 100; | |
52 | $ready = 0; | |
53 | @saved = (); | |
54 | @skippkg = (); | |
55 | $usrctxt = ''; | |
56 | $evalarg = ''; | |
57 | } | |
58 | ||
59 | #### | |
60 | # entry point for all subroutine calls | |
61 | # | |
62 | sub sub { | |
63 | push(@stack, $DB::single); | |
64 | $DB::single &= 1; | |
65 | $DB::single |= 4 if $#stack == $deep; | |
66 | # print $DB::sub, "\n"; | |
67 | if ($DB::sub =~ /(?:^|::)DESTROY$/ or not defined wantarray) { | |
68 | &$DB::sub; | |
69 | $DB::single |= pop(@stack); | |
70 | $DB::ret = undef; | |
71 | } | |
72 | elsif (wantarray) { | |
73 | @DB::ret = &$DB::sub; | |
74 | $DB::single |= pop(@stack); | |
75 | @DB::ret; | |
76 | } | |
77 | else { | |
78 | $DB::ret = &$DB::sub; | |
79 | $DB::single |= pop(@stack); | |
80 | $DB::ret; | |
81 | } | |
82 | } | |
83 | ||
84 | #### | |
85 | # this is called by perl for every statement | |
86 | # | |
87 | sub DB { | |
88 | return unless $ready; | |
89 | &save; | |
90 | ($DB::package, $DB::filename, $DB::lineno) = caller; | |
91 | ||
92 | return if @skippkg and grep { $_ eq $DB::package } @skippkg; | |
93 | ||
94 | $usrctxt = "package $DB::package;"; # this won't let them modify, alas | |
95 | local(*DB::dbline) = "::_<$DB::filename"; | |
96 | my ($stop, $action); | |
97 | if (($stop,$action) = split(/\0/,$DB::dbline{$DB::lineno})) { | |
98 | if ($stop eq '1') { | |
99 | $DB::signal |= 1; | |
100 | } | |
101 | else { | |
102 | $stop = 0 unless $stop; # avoid un_init warning | |
103 | $evalarg = "\$DB::signal |= do { $stop; }"; &eval; | |
104 | $DB::dbline{$DB::lineno} =~ s/;9($|\0)/$1/; # clear any temp breakpt | |
105 | } | |
106 | } | |
107 | if ($DB::single || $DB::trace || $DB::signal) { | |
108 | $DB::subname = ($DB::sub =~ /\'|::/) ? $DB::sub : "${DB::package}::$DB::sub"; #'; | |
109 | DB->loadfile($DB::filename, $DB::lineno); | |
110 | } | |
111 | $evalarg = $action, &eval if $action; | |
112 | if ($DB::single || $DB::signal) { | |
113 | _outputall($#stack . " levels deep in subroutine calls.\n") if $DB::single & 4; | |
114 | $DB::single = 0; | |
115 | $DB::signal = 0; | |
116 | $running = 0; | |
117 | ||
118 | &eval if ($evalarg = DB->prestop); | |
119 | my $c; | |
120 | for $c (@clients) { | |
121 | # perform any client-specific prestop actions | |
122 | &eval if ($evalarg = $c->cprestop); | |
123 | ||
124 | # Now sit in an event loop until something sets $running | |
125 | do { | |
126 | $c->idle; # call client event loop; must not block | |
127 | if ($running == 2) { # client wants something eval-ed | |
128 | &eval if ($evalarg = $c->evalcode); | |
129 | $running = 0; | |
130 | } | |
131 | } until $running; | |
132 | ||
133 | # perform any client-specific poststop actions | |
134 | &eval if ($evalarg = $c->cpoststop); | |
135 | } | |
136 | &eval if ($evalarg = DB->poststop); | |
137 | } | |
138 | ($@, $!, $,, $/, $\, $^W) = @saved; | |
139 | (); | |
140 | } | |
141 | ||
142 | #### | |
143 | # this takes its argument via $evalarg to preserve current @_ | |
144 | # | |
145 | sub eval { | |
146 | ($@, $!, $,, $/, $\, $^W) = @saved; | |
147 | eval "$usrctxt $evalarg; &DB::save"; | |
148 | _outputall($@) if $@; | |
149 | } | |
150 | ||
151 | ############################################################################### | |
152 | # no compile-time subroutine call allowed before this point # | |
153 | ############################################################################### | |
154 | ||
155 | use strict; # this can run only after DB() and sub() are defined | |
156 | ||
157 | sub save { | |
158 | @saved = ($@, $!, $,, $/, $\, $^W); | |
159 | $, = ""; $/ = "\n"; $\ = ""; $^W = 0; | |
160 | } | |
161 | ||
162 | sub catch { | |
163 | for (@clients) { $_->awaken; } | |
164 | $DB::signal = 1; | |
165 | $ready = 1; | |
166 | } | |
167 | ||
168 | #### | |
169 | # | |
170 | # Client callable (read inheritable) methods defined after this point | |
171 | # | |
172 | #### | |
173 | ||
174 | sub register { | |
175 | my $s = shift; | |
176 | $s = _clientname($s) if ref($s); | |
177 | push @clients, $s; | |
178 | } | |
179 | ||
180 | sub done { | |
181 | my $s = shift; | |
182 | $s = _clientname($s) if ref($s); | |
183 | @clients = grep {$_ ne $s} @clients; | |
184 | $s->cleanup; | |
185 | # $running = 3 unless @clients; | |
186 | exit(0) unless @clients; | |
187 | } | |
188 | ||
189 | sub _clientname { | |
190 | my $name = shift; | |
191 | "$name" =~ /^(.+)=[A-Z]+\(.+\)$/; | |
192 | return $1; | |
193 | } | |
194 | ||
195 | sub next { | |
196 | my $s = shift; | |
197 | $DB::single = 2; | |
198 | $running = 1; | |
199 | } | |
200 | ||
201 | sub step { | |
202 | my $s = shift; | |
203 | $DB::single = 1; | |
204 | $running = 1; | |
205 | } | |
206 | ||
207 | sub cont { | |
208 | my $s = shift; | |
209 | my $i = shift; | |
210 | $s->set_tbreak($i) if $i; | |
211 | for ($i = 0; $i <= $#stack;) { | |
212 | $stack[$i++] &= ~1; | |
213 | } | |
214 | $DB::single = 0; | |
215 | $running = 1; | |
216 | } | |
217 | ||
218 | #### | |
219 | # XXX caller must experimentally determine $i (since it depends | |
220 | # on how many client call frames are between this call and the DB call). | |
221 | # Such is life. | |
222 | # | |
223 | sub ret { | |
224 | my $s = shift; | |
225 | my $i = shift; # how many levels to get to DB sub | |
226 | $i = 0 unless defined $i; | |
227 | $stack[$#stack-$i] |= 1; | |
228 | $DB::single = 0; | |
229 | $running = 1; | |
230 | } | |
231 | ||
232 | #### | |
233 | # XXX caller must experimentally determine $start (since it depends | |
234 | # on how many client call frames are between this call and the DB call). | |
235 | # Such is life. | |
236 | # | |
237 | sub backtrace { | |
238 | my $self = shift; | |
239 | my $start = shift; | |
240 | my($p,$f,$l,$s,$h,$w,$e,$r,$a, @a, @ret,$i); | |
241 | $start = 1 unless $start; | |
242 | for ($i = $start; ($p,$f,$l,$s,$h,$w,$e,$r) = caller($i); $i++) { | |
243 | @a = @DB::args; | |
244 | for (@a) { | |
245 | s/'/\\'/g; | |
246 | s/([^\0]*)/'$1'/ unless /^-?[\d.]+$/; | |
247 | s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg; | |
248 | s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg; | |
249 | } | |
250 | $w = $w ? '@ = ' : '$ = '; | |
251 | $a = $h ? '(' . join(', ', @a) . ')' : ''; | |
252 | $e =~ s/\n\s*\;\s*\Z// if $e; | |
253 | $e =~ s/[\\\']/\\$1/g if $e; | |
254 | if ($r) { | |
255 | $s = "require '$e'"; | |
256 | } elsif (defined $r) { | |
257 | $s = "eval '$e'"; | |
258 | } elsif ($s eq '(eval)') { | |
259 | $s = "eval {...}"; | |
260 | } | |
261 | $f = "file `$f'" unless $f eq '-e'; | |
262 | push @ret, "$w&$s$a from $f line $l"; | |
263 | last if $DB::signal; | |
264 | } | |
265 | return @ret; | |
266 | } | |
267 | ||
268 | sub _outputall { | |
269 | my $c; | |
270 | for $c (@clients) { | |
271 | $c->output(@_); | |
272 | } | |
273 | } | |
274 | ||
275 | sub trace_toggle { | |
276 | my $s = shift; | |
277 | $DB::trace = !$DB::trace; | |
278 | } | |
279 | ||
280 | ||
281 | #### | |
282 | # without args: returns all defined subroutine names | |
283 | # with subname args: returns a listref [file, start, end] | |
284 | # | |
285 | sub subs { | |
286 | my $s = shift; | |
287 | if (@_) { | |
288 | my(@ret) = (); | |
289 | while (@_) { | |
290 | my $name = shift; | |
291 | push @ret, [$DB::sub{$name} =~ /^(.*)\:(\d+)-(\d+)$/] | |
292 | if exists $DB::sub{$name}; | |
293 | } | |
294 | return @ret; | |
295 | } | |
296 | return keys %DB::sub; | |
297 | } | |
298 | ||
299 | #### | |
300 | # first argument is a filename whose subs will be returned | |
301 | # if a filename is not supplied, all subs in the current | |
302 | # filename are returned. | |
303 | # | |
304 | sub filesubs { | |
305 | my $s = shift; | |
306 | my $fname = shift; | |
307 | $fname = $DB::filename unless $fname; | |
308 | return grep { $DB::sub{$_} =~ /^$fname/ } keys %DB::sub; | |
309 | } | |
310 | ||
311 | #### | |
312 | # returns a list of all filenames that DB knows about | |
313 | # | |
314 | sub files { | |
315 | my $s = shift; | |
316 | my(@f) = grep(m|^_<|, keys %main::); | |
317 | return map { substr($_,2) } @f; | |
318 | } | |
319 | ||
320 | #### | |
321 | # returns reference to an array holding the lines in currently | |
322 | # loaded file | |
323 | # | |
324 | sub lines { | |
325 | my $s = shift; | |
326 | return \@DB::dbline; | |
327 | } | |
328 | ||
329 | #### | |
330 | # loadfile($file, $line) | |
331 | # | |
332 | sub loadfile { | |
333 | my $s = shift; | |
334 | my($file, $line) = @_; | |
335 | if (!defined $main::{'_<' . $file}) { | |
336 | my $try; | |
337 | if (($try) = grep(m|^_<.*$file|, keys %main::)) { | |
338 | $file = substr($try,2); | |
339 | } | |
340 | } | |
341 | if (defined($main::{'_<' . $file})) { | |
342 | my $c; | |
343 | # _outputall("Loading file $file.."); | |
344 | *DB::dbline = "::_<$file"; | |
345 | $DB::filename = $file; | |
346 | for $c (@clients) { | |
347 | # print "2 ", $file, '|', $line, "\n"; | |
348 | $c->showfile($file, $line); | |
349 | } | |
350 | return $file; | |
351 | } | |
352 | return undef; | |
353 | } | |
354 | ||
355 | sub lineevents { | |
356 | my $s = shift; | |
357 | my $fname = shift; | |
358 | my(%ret) = (); | |
359 | my $i; | |
360 | $fname = $DB::filename unless $fname; | |
361 | local(*DB::dbline) = "::_<$fname"; | |
362 | for ($i = 1; $i <= $#DB::dbline; $i++) { | |
363 | $ret{$i} = [$DB::dbline[$i], split(/\0/, $DB::dbline{$i})] | |
364 | if defined $DB::dbline{$i}; | |
365 | } | |
366 | return %ret; | |
367 | } | |
368 | ||
369 | sub set_break { | |
370 | my $s = shift; | |
371 | my $i = shift; | |
372 | my $cond = shift; | |
373 | $i ||= $DB::lineno; | |
374 | $cond ||= '1'; | |
375 | $i = _find_subline($i) if ($i =~ /\D/); | |
376 | $s->output("Subroutine not found.\n") unless $i; | |
377 | if ($i) { | |
378 | if ($DB::dbline[$i] == 0) { | |
379 | $s->output("Line $i not breakable.\n"); | |
380 | } | |
381 | else { | |
382 | $DB::dbline{$i} =~ s/^[^\0]*/$cond/; | |
383 | } | |
384 | } | |
385 | } | |
386 | ||
387 | sub set_tbreak { | |
388 | my $s = shift; | |
389 | my $i = shift; | |
390 | $i = _find_subline($i) if ($i =~ /\D/); | |
391 | $s->output("Subroutine not found.\n") unless $i; | |
392 | if ($i) { | |
393 | if ($DB::dbline[$i] == 0) { | |
394 | $s->output("Line $i not breakable.\n"); | |
395 | } | |
396 | else { | |
397 | $DB::dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p. | |
398 | } | |
399 | } | |
400 | } | |
401 | ||
402 | sub _find_subline { | |
403 | my $name = shift; | |
404 | $name =~ s/\'/::/; | |
405 | $name = "${DB::package}\:\:" . $name if $name !~ /::/; | |
406 | $name = "main" . $name if substr($name,0,2) eq "::"; | |
407 | my($fname, $from, $to) = ($DB::sub{$name} =~ /^(.*):(\d+)-(\d+)$/); | |
408 | if ($from) { | |
c95f170b | 409 | local *DB::dbline = "::_<$fname"; |
43d8869b GS |
410 | ++$from while $DB::dbline[$from] == 0 && $from < $to; |
411 | return $from; | |
412 | } | |
413 | return undef; | |
414 | } | |
415 | ||
416 | sub clr_breaks { | |
417 | my $s = shift; | |
418 | my $i; | |
419 | if (@_) { | |
420 | while (@_) { | |
421 | $i = shift; | |
422 | $i = _find_subline($i) if ($i =~ /\D/); | |
423 | $s->output("Subroutine not found.\n") unless $i; | |
424 | if (defined $DB::dbline{$i}) { | |
425 | $DB::dbline{$i} =~ s/^[^\0]+//; | |
426 | if ($DB::dbline{$i} =~ s/^\0?$//) { | |
427 | delete $DB::dbline{$i}; | |
428 | } | |
429 | } | |
430 | } | |
431 | } | |
432 | else { | |
433 | for ($i = 1; $i <= $#DB::dbline ; $i++) { | |
434 | if (defined $DB::dbline{$i}) { | |
435 | $DB::dbline{$i} =~ s/^[^\0]+//; | |
436 | if ($DB::dbline{$i} =~ s/^\0?$//) { | |
437 | delete $DB::dbline{$i}; | |
438 | } | |
439 | } | |
440 | } | |
441 | } | |
442 | } | |
443 | ||
444 | sub set_action { | |
445 | my $s = shift; | |
446 | my $i = shift; | |
447 | my $act = shift; | |
448 | $i = _find_subline($i) if ($i =~ /\D/); | |
449 | $s->output("Subroutine not found.\n") unless $i; | |
450 | if ($i) { | |
451 | if ($DB::dbline[$i] == 0) { | |
452 | $s->output("Line $i not actionable.\n"); | |
453 | } | |
454 | else { | |
455 | $DB::dbline{$i} =~ s/\0[^\0]*//; | |
456 | $DB::dbline{$i} .= "\0" . $act; | |
457 | } | |
458 | } | |
459 | } | |
460 | ||
461 | sub clr_actions { | |
462 | my $s = shift; | |
463 | my $i; | |
464 | if (@_) { | |
465 | while (@_) { | |
466 | my $i = shift; | |
467 | $i = _find_subline($i) if ($i =~ /\D/); | |
468 | $s->output("Subroutine not found.\n") unless $i; | |
469 | if ($i && $DB::dbline[$i] != 0) { | |
470 | $DB::dbline{$i} =~ s/\0[^\0]*//; | |
471 | delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; | |
472 | } | |
473 | } | |
474 | } | |
475 | else { | |
476 | for ($i = 1; $i <= $#DB::dbline ; $i++) { | |
477 | if (defined $DB::dbline{$i}) { | |
478 | $DB::dbline{$i} =~ s/\0[^\0]*//; | |
479 | delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; | |
480 | } | |
481 | } | |
482 | } | |
483 | } | |
484 | ||
485 | sub prestop { | |
486 | my ($client, $val) = @_; | |
487 | return defined($val) ? $preeval->{$client} = $val : $preeval->{$client}; | |
488 | } | |
489 | ||
490 | sub poststop { | |
491 | my ($client, $val) = @_; | |
492 | return defined($val) ? $posteval->{$client} = $val : $posteval->{$client}; | |
493 | } | |
494 | ||
495 | # | |
496 | # "pure virtual" methods | |
497 | # | |
498 | ||
499 | # client-specific pre/post-stop actions. | |
500 | sub cprestop {} | |
501 | sub cpoststop {} | |
502 | ||
503 | # client complete startup | |
504 | sub awaken {} | |
505 | ||
506 | sub skippkg { | |
507 | my $s = shift; | |
508 | push @skippkg, @_ if @_; | |
509 | } | |
510 | ||
511 | sub evalcode { | |
512 | my ($client, $val) = @_; | |
513 | if (defined $val) { | |
514 | $running = 2; # hand over to DB() to evaluate in its context | |
515 | $ineval->{$client} = $val; | |
516 | } | |
517 | return $ineval->{$client}; | |
518 | } | |
519 | ||
520 | sub ready { | |
521 | my $s = shift; | |
522 | return $ready = 1; | |
523 | } | |
524 | ||
525 | # stubs | |
526 | ||
527 | sub init {} | |
528 | sub stop {} | |
529 | sub idle {} | |
530 | sub cleanup {} | |
531 | sub output {} | |
532 | ||
533 | # | |
534 | # client init | |
535 | # | |
536 | for (@clients) { $_->init } | |
537 | ||
538 | $SIG{'INT'} = \&DB::catch; | |
539 | ||
540 | # disable this if stepping through END blocks is desired | |
541 | # (looks scary and deconstructivist with Swat) | |
542 | END { $ready = 0 } | |
543 | ||
544 | 1; | |
545 | __END__ | |
546 | ||
547 | =head1 NAME | |
548 | ||
549 | DB - programmatic interface to the Perl debugging API (draft, subject to | |
550 | change) | |
551 | ||
552 | =head1 SYNOPSIS | |
553 | ||
554 | package CLIENT; | |
555 | use DB; | |
556 | @ISA = qw(DB); | |
3cb6de81 | 557 | |
43d8869b | 558 | # these (inherited) methods can be called by the client |
3cb6de81 | 559 | |
43d8869b GS |
560 | CLIENT->register() # register a client package name |
561 | CLIENT->done() # de-register from the debugging API | |
562 | CLIENT->skippkg('hide::hide') # ask DB not to stop in this package | |
563 | CLIENT->cont([WHERE]) # run some more (until BREAK or another breakpt) | |
564 | CLIENT->step() # single step | |
565 | CLIENT->next() # step over | |
566 | CLIENT->ret() # return from current subroutine | |
567 | CLIENT->backtrace() # return the call stack description | |
568 | CLIENT->ready() # call when client setup is done | |
569 | CLIENT->trace_toggle() # toggle subroutine call trace mode | |
570 | CLIENT->subs([SUBS]) # return subroutine information | |
571 | CLIENT->files() # return list of all files known to DB | |
572 | CLIENT->lines() # return lines in currently loaded file | |
573 | CLIENT->loadfile(FILE,LINE) # load a file and let other clients know | |
574 | CLIENT->lineevents() # return info on lines with actions | |
575 | CLIENT->set_break([WHERE],[COND]) | |
576 | CLIENT->set_tbreak([WHERE]) | |
577 | CLIENT->clr_breaks([LIST]) | |
578 | CLIENT->set_action(WHERE,ACTION) | |
579 | CLIENT->clr_actions([LIST]) | |
580 | CLIENT->evalcode(STRING) # eval STRING in executing code's context | |
581 | CLIENT->prestop([STRING]) # execute in code context before stopping | |
582 | CLIENT->poststop([STRING])# execute in code context before resuming | |
583 | ||
584 | # These methods will be called at the appropriate times. | |
585 | # Stub versions provided do nothing. | |
586 | # None of these can block. | |
3cb6de81 | 587 | |
43d8869b GS |
588 | CLIENT->init() # called when debug API inits itself |
589 | CLIENT->stop(FILE,LINE) # when execution stops | |
590 | CLIENT->idle() # while stopped (can be a client event loop) | |
591 | CLIENT->cleanup() # just before exit | |
592 | CLIENT->output(LIST) # called to print any output that API must show | |
593 | ||
594 | =head1 DESCRIPTION | |
595 | ||
596 | Perl debug information is frequently required not just by debuggers, | |
597 | but also by modules that need some "special" information to do their | |
598 | job properly, like profilers. | |
599 | ||
600 | This module abstracts and provides all of the hooks into Perl internal | |
601 | debugging functionality, so that various implementations of Perl debuggers | |
602 | (or packages that want to simply get at the "privileged" debugging data) | |
603 | can all benefit from the development of this common code. Currently used | |
604 | by Swat, the perl/Tk GUI debugger. | |
605 | ||
606 | Note that multiple "front-ends" can latch into this debugging API | |
607 | simultaneously. This is intended to facilitate things like | |
608 | debugging with a command line and GUI at the same time, debugging | |
609 | debuggers etc. [Sounds nice, but this needs some serious support -- GSAR] | |
610 | ||
611 | In particular, this API does B<not> provide the following functions: | |
612 | ||
613 | =over 4 | |
614 | ||
615 | =item * | |
616 | ||
617 | data display | |
618 | ||
619 | =item * | |
620 | ||
621 | command processing | |
622 | ||
623 | =item * | |
624 | ||
625 | command alias management | |
626 | ||
627 | =item * | |
628 | ||
629 | user interface (tty or graphical) | |
630 | ||
631 | =back | |
632 | ||
633 | These are intended to be services performed by the clients of this API. | |
634 | ||
635 | This module attempts to be squeaky clean w.r.t C<use strict;> and when | |
636 | warnings are enabled. | |
637 | ||
638 | ||
639 | =head2 Global Variables | |
640 | ||
641 | The following "public" global names can be read by clients of this API. | |
642 | Beware that these should be considered "readonly". | |
643 | ||
644 | =over 8 | |
645 | ||
646 | =item $DB::sub | |
647 | ||
648 | Name of current executing subroutine. | |
649 | ||
650 | =item %DB::sub | |
651 | ||
652 | The keys of this hash are the names of all the known subroutines. Each value | |
653 | is an encoded string that has the sprintf(3) format | |
654 | C<("%s:%d-%d", filename, fromline, toline)>. | |
655 | ||
656 | =item $DB::single | |
657 | ||
658 | Single-step flag. Will be true if the API will stop at the next statement. | |
659 | ||
660 | =item $DB::signal | |
661 | ||
662 | Signal flag. Will be set to a true value if a signal was caught. Clients may | |
663 | check for this flag to abort time-consuming operations. | |
664 | ||
665 | =item $DB::trace | |
666 | ||
667 | This flag is set to true if the API is tracing through subroutine calls. | |
668 | ||
669 | =item @DB::args | |
670 | ||
671 | Contains the arguments of current subroutine, or the C<@ARGV> array if in the | |
672 | toplevel context. | |
673 | ||
674 | =item @DB::dbline | |
675 | ||
676 | List of lines in currently loaded file. | |
677 | ||
678 | =item %DB::dbline | |
679 | ||
680 | Actions in current file (keys are line numbers). The values are strings that | |
681 | have the sprintf(3) format C<("%s\000%s", breakcondition, actioncode)>. | |
682 | ||
683 | =item $DB::package | |
684 | ||
685 | Package namespace of currently executing code. | |
686 | ||
687 | =item $DB::filename | |
688 | ||
689 | Currently loaded filename. | |
690 | ||
691 | =item $DB::subname | |
692 | ||
693 | Fully qualified name of currently executing subroutine. | |
694 | ||
695 | =item $DB::lineno | |
696 | ||
697 | Line number that will be executed next. | |
698 | ||
699 | =back | |
700 | ||
701 | =head2 API Methods | |
702 | ||
703 | The following are methods in the DB base class. A client must | |
704 | access these methods by inheritance (*not* by calling them directly), | |
705 | since the API keeps track of clients through the inheritance | |
706 | mechanism. | |
707 | ||
708 | =over 8 | |
709 | ||
710 | =item CLIENT->register() | |
711 | ||
712 | register a client object/package | |
713 | ||
714 | =item CLIENT->evalcode(STRING) | |
715 | ||
716 | eval STRING in executing code context | |
717 | ||
718 | =item CLIENT->skippkg('D::hide') | |
719 | ||
720 | ask DB not to stop in these packages | |
721 | ||
722 | =item CLIENT->run() | |
723 | ||
724 | run some more (until a breakpt is reached) | |
725 | ||
726 | =item CLIENT->step() | |
727 | ||
728 | single step | |
729 | ||
730 | =item CLIENT->next() | |
731 | ||
732 | step over | |
733 | ||
734 | =item CLIENT->done() | |
735 | ||
736 | de-register from the debugging API | |
737 | ||
738 | =back | |
739 | ||
740 | =head2 Client Callback Methods | |
741 | ||
742 | The following "virtual" methods can be defined by the client. They will | |
743 | be called by the API at appropriate points. Note that unless specified | |
744 | otherwise, the debug API only defines empty, non-functional default versions | |
745 | of these methods. | |
746 | ||
747 | =over 8 | |
748 | ||
749 | =item CLIENT->init() | |
750 | ||
751 | Called after debug API inits itself. | |
752 | ||
753 | =item CLIENT->prestop([STRING]) | |
754 | ||
755 | Usually inherited from DB package. If no arguments are passed, | |
756 | returns the prestop action string. | |
757 | ||
758 | =item CLIENT->stop() | |
759 | ||
760 | Called when execution stops (w/ args file, line). | |
761 | ||
762 | =item CLIENT->idle() | |
763 | ||
764 | Called while stopped (can be a client event loop). | |
765 | ||
766 | =item CLIENT->poststop([STRING]) | |
767 | ||
768 | Usually inherited from DB package. If no arguments are passed, | |
769 | returns the poststop action string. | |
770 | ||
771 | =item CLIENT->evalcode(STRING) | |
772 | ||
773 | Usually inherited from DB package. Ask for a STRING to be C<eval>-ed | |
774 | in executing code context. | |
775 | ||
776 | =item CLIENT->cleanup() | |
777 | ||
778 | Called just before exit. | |
779 | ||
780 | =item CLIENT->output(LIST) | |
781 | ||
782 | Called when API must show a message (warnings, errors etc.). | |
783 | ||
784 | ||
785 | =back | |
786 | ||
787 | ||
788 | =head1 BUGS | |
789 | ||
790 | The interface defined by this module is missing some of the later additions | |
791 | to perl's debugging functionality. As such, this interface should be considered | |
792 | highly experimental and subject to change. | |
793 | ||
794 | =head1 AUTHOR | |
795 | ||
6e238990 | 796 | Gurusamy Sarathy gsar@activestate.com |
43d8869b GS |
797 | |
798 | This code heavily adapted from an early version of perl5db.pl attributable | |
799 | to Larry Wall and the Perl Porters. | |
800 | ||
801 | =cut |