| Commit | Line | Data |
|---|
| 43d8869b |
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 ($from) { |
| 409 | # XXX this needs local()-ization of some sort |
| 410 | *DB::dbline = "::_<$fname"; |
| 411 | ++$from while $DB::dbline[$from] == 0 && $from < $to; |
| 412 | return $from; |
| 413 | } |
| 414 | return undef; |
| 415 | } |
| 416 | |
| 417 | sub clr_breaks { |
| 418 | my $s = shift; |
| 419 | my $i; |
| 420 | if (@_) { |
| 421 | while (@_) { |
| 422 | $i = shift; |
| 423 | $i = _find_subline($i) if ($i =~ /\D/); |
| 424 | $s->output("Subroutine not found.\n") unless $i; |
| 425 | if (defined $DB::dbline{$i}) { |
| 426 | $DB::dbline{$i} =~ s/^[^\0]+//; |
| 427 | if ($DB::dbline{$i} =~ s/^\0?$//) { |
| 428 | delete $DB::dbline{$i}; |
| 429 | } |
| 430 | } |
| 431 | } |
| 432 | } |
| 433 | else { |
| 434 | for ($i = 1; $i <= $#DB::dbline ; $i++) { |
| 435 | if (defined $DB::dbline{$i}) { |
| 436 | $DB::dbline{$i} =~ s/^[^\0]+//; |
| 437 | if ($DB::dbline{$i} =~ s/^\0?$//) { |
| 438 | delete $DB::dbline{$i}; |
| 439 | } |
| 440 | } |
| 441 | } |
| 442 | } |
| 443 | } |
| 444 | |
| 445 | sub set_action { |
| 446 | my $s = shift; |
| 447 | my $i = shift; |
| 448 | my $act = shift; |
| 449 | $i = _find_subline($i) if ($i =~ /\D/); |
| 450 | $s->output("Subroutine not found.\n") unless $i; |
| 451 | if ($i) { |
| 452 | if ($DB::dbline[$i] == 0) { |
| 453 | $s->output("Line $i not actionable.\n"); |
| 454 | } |
| 455 | else { |
| 456 | $DB::dbline{$i} =~ s/\0[^\0]*//; |
| 457 | $DB::dbline{$i} .= "\0" . $act; |
| 458 | } |
| 459 | } |
| 460 | } |
| 461 | |
| 462 | sub clr_actions { |
| 463 | my $s = shift; |
| 464 | my $i; |
| 465 | if (@_) { |
| 466 | while (@_) { |
| 467 | my $i = shift; |
| 468 | $i = _find_subline($i) if ($i =~ /\D/); |
| 469 | $s->output("Subroutine not found.\n") unless $i; |
| 470 | if ($i && $DB::dbline[$i] != 0) { |
| 471 | $DB::dbline{$i} =~ s/\0[^\0]*//; |
| 472 | delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; |
| 473 | } |
| 474 | } |
| 475 | } |
| 476 | else { |
| 477 | for ($i = 1; $i <= $#DB::dbline ; $i++) { |
| 478 | if (defined $DB::dbline{$i}) { |
| 479 | $DB::dbline{$i} =~ s/\0[^\0]*//; |
| 480 | delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; |
| 481 | } |
| 482 | } |
| 483 | } |
| 484 | } |
| 485 | |
| 486 | sub prestop { |
| 487 | my ($client, $val) = @_; |
| 488 | return defined($val) ? $preeval->{$client} = $val : $preeval->{$client}; |
| 489 | } |
| 490 | |
| 491 | sub poststop { |
| 492 | my ($client, $val) = @_; |
| 493 | return defined($val) ? $posteval->{$client} = $val : $posteval->{$client}; |
| 494 | } |
| 495 | |
| 496 | # |
| 497 | # "pure virtual" methods |
| 498 | # |
| 499 | |
| 500 | # client-specific pre/post-stop actions. |
| 501 | sub cprestop {} |
| 502 | sub cpoststop {} |
| 503 | |
| 504 | # client complete startup |
| 505 | sub awaken {} |
| 506 | |
| 507 | sub skippkg { |
| 508 | my $s = shift; |
| 509 | push @skippkg, @_ if @_; |
| 510 | } |
| 511 | |
| 512 | sub evalcode { |
| 513 | my ($client, $val) = @_; |
| 514 | if (defined $val) { |
| 515 | $running = 2; # hand over to DB() to evaluate in its context |
| 516 | $ineval->{$client} = $val; |
| 517 | } |
| 518 | return $ineval->{$client}; |
| 519 | } |
| 520 | |
| 521 | sub ready { |
| 522 | my $s = shift; |
| 523 | return $ready = 1; |
| 524 | } |
| 525 | |
| 526 | # stubs |
| 527 | |
| 528 | sub init {} |
| 529 | sub stop {} |
| 530 | sub idle {} |
| 531 | sub cleanup {} |
| 532 | sub output {} |
| 533 | |
| 534 | # |
| 535 | # client init |
| 536 | # |
| 537 | for (@clients) { $_->init } |
| 538 | |
| 539 | $SIG{'INT'} = \&DB::catch; |
| 540 | |
| 541 | # disable this if stepping through END blocks is desired |
| 542 | # (looks scary and deconstructivist with Swat) |
| 543 | END { $ready = 0 } |
| 544 | |
| 545 | 1; |
| 546 | __END__ |
| 547 | |
| 548 | =head1 NAME |
| 549 | |
| 550 | DB - programmatic interface to the Perl debugging API (draft, subject to |
| 551 | change) |
| 552 | |
| 553 | =head1 SYNOPSIS |
| 554 | |
| 555 | package CLIENT; |
| 556 | use DB; |
| 557 | @ISA = qw(DB); |
| 3cb6de81 |
558 | |
| 43d8869b |
559 | # these (inherited) methods can be called by the client |
| 3cb6de81 |
560 | |
| 43d8869b |
561 | CLIENT->register() # register a client package name |
| 562 | CLIENT->done() # de-register from the debugging API |
| 563 | CLIENT->skippkg('hide::hide') # ask DB not to stop in this package |
| 564 | CLIENT->cont([WHERE]) # run some more (until BREAK or another breakpt) |
| 565 | CLIENT->step() # single step |
| 566 | CLIENT->next() # step over |
| 567 | CLIENT->ret() # return from current subroutine |
| 568 | CLIENT->backtrace() # return the call stack description |
| 569 | CLIENT->ready() # call when client setup is done |
| 570 | CLIENT->trace_toggle() # toggle subroutine call trace mode |
| 571 | CLIENT->subs([SUBS]) # return subroutine information |
| 572 | CLIENT->files() # return list of all files known to DB |
| 573 | CLIENT->lines() # return lines in currently loaded file |
| 574 | CLIENT->loadfile(FILE,LINE) # load a file and let other clients know |
| 575 | CLIENT->lineevents() # return info on lines with actions |
| 576 | CLIENT->set_break([WHERE],[COND]) |
| 577 | CLIENT->set_tbreak([WHERE]) |
| 578 | CLIENT->clr_breaks([LIST]) |
| 579 | CLIENT->set_action(WHERE,ACTION) |
| 580 | CLIENT->clr_actions([LIST]) |
| 581 | CLIENT->evalcode(STRING) # eval STRING in executing code's context |
| 582 | CLIENT->prestop([STRING]) # execute in code context before stopping |
| 583 | CLIENT->poststop([STRING])# execute in code context before resuming |
| 584 | |
| 585 | # These methods will be called at the appropriate times. |
| 586 | # Stub versions provided do nothing. |
| 587 | # None of these can block. |
| 3cb6de81 |
588 | |
| 43d8869b |
589 | CLIENT->init() # called when debug API inits itself |
| 590 | CLIENT->stop(FILE,LINE) # when execution stops |
| 591 | CLIENT->idle() # while stopped (can be a client event loop) |
| 592 | CLIENT->cleanup() # just before exit |
| 593 | CLIENT->output(LIST) # called to print any output that API must show |
| 594 | |
| 595 | =head1 DESCRIPTION |
| 596 | |
| 597 | Perl debug information is frequently required not just by debuggers, |
| 598 | but also by modules that need some "special" information to do their |
| 599 | job properly, like profilers. |
| 600 | |
| 601 | This module abstracts and provides all of the hooks into Perl internal |
| 602 | debugging functionality, so that various implementations of Perl debuggers |
| 603 | (or packages that want to simply get at the "privileged" debugging data) |
| 604 | can all benefit from the development of this common code. Currently used |
| 605 | by Swat, the perl/Tk GUI debugger. |
| 606 | |
| 607 | Note that multiple "front-ends" can latch into this debugging API |
| 608 | simultaneously. This is intended to facilitate things like |
| 609 | debugging with a command line and GUI at the same time, debugging |
| 610 | debuggers etc. [Sounds nice, but this needs some serious support -- GSAR] |
| 611 | |
| 612 | In particular, this API does B<not> provide the following functions: |
| 613 | |
| 614 | =over 4 |
| 615 | |
| 616 | =item * |
| 617 | |
| 618 | data display |
| 619 | |
| 620 | =item * |
| 621 | |
| 622 | command processing |
| 623 | |
| 624 | =item * |
| 625 | |
| 626 | command alias management |
| 627 | |
| 628 | =item * |
| 629 | |
| 630 | user interface (tty or graphical) |
| 631 | |
| 632 | =back |
| 633 | |
| 634 | These are intended to be services performed by the clients of this API. |
| 635 | |
| 636 | This module attempts to be squeaky clean w.r.t C<use strict;> and when |
| 637 | warnings are enabled. |
| 638 | |
| 639 | |
| 640 | =head2 Global Variables |
| 641 | |
| 642 | The following "public" global names can be read by clients of this API. |
| 643 | Beware that these should be considered "readonly". |
| 644 | |
| 645 | =over 8 |
| 646 | |
| 647 | =item $DB::sub |
| 648 | |
| 649 | Name of current executing subroutine. |
| 650 | |
| 651 | =item %DB::sub |
| 652 | |
| 653 | The keys of this hash are the names of all the known subroutines. Each value |
| 654 | is an encoded string that has the sprintf(3) format |
| 655 | C<("%s:%d-%d", filename, fromline, toline)>. |
| 656 | |
| 657 | =item $DB::single |
| 658 | |
| 659 | Single-step flag. Will be true if the API will stop at the next statement. |
| 660 | |
| 661 | =item $DB::signal |
| 662 | |
| 663 | Signal flag. Will be set to a true value if a signal was caught. Clients may |
| 664 | check for this flag to abort time-consuming operations. |
| 665 | |
| 666 | =item $DB::trace |
| 667 | |
| 668 | This flag is set to true if the API is tracing through subroutine calls. |
| 669 | |
| 670 | =item @DB::args |
| 671 | |
| 672 | Contains the arguments of current subroutine, or the C<@ARGV> array if in the |
| 673 | toplevel context. |
| 674 | |
| 675 | =item @DB::dbline |
| 676 | |
| 677 | List of lines in currently loaded file. |
| 678 | |
| 679 | =item %DB::dbline |
| 680 | |
| 681 | Actions in current file (keys are line numbers). The values are strings that |
| 682 | have the sprintf(3) format C<("%s\000%s", breakcondition, actioncode)>. |
| 683 | |
| 684 | =item $DB::package |
| 685 | |
| 686 | Package namespace of currently executing code. |
| 687 | |
| 688 | =item $DB::filename |
| 689 | |
| 690 | Currently loaded filename. |
| 691 | |
| 692 | =item $DB::subname |
| 693 | |
| 694 | Fully qualified name of currently executing subroutine. |
| 695 | |
| 696 | =item $DB::lineno |
| 697 | |
| 698 | Line number that will be executed next. |
| 699 | |
| 700 | =back |
| 701 | |
| 702 | =head2 API Methods |
| 703 | |
| 704 | The following are methods in the DB base class. A client must |
| 705 | access these methods by inheritance (*not* by calling them directly), |
| 706 | since the API keeps track of clients through the inheritance |
| 707 | mechanism. |
| 708 | |
| 709 | =over 8 |
| 710 | |
| 711 | =item CLIENT->register() |
| 712 | |
| 713 | register a client object/package |
| 714 | |
| 715 | =item CLIENT->evalcode(STRING) |
| 716 | |
| 717 | eval STRING in executing code context |
| 718 | |
| 719 | =item CLIENT->skippkg('D::hide') |
| 720 | |
| 721 | ask DB not to stop in these packages |
| 722 | |
| 723 | =item CLIENT->run() |
| 724 | |
| 725 | run some more (until a breakpt is reached) |
| 726 | |
| 727 | =item CLIENT->step() |
| 728 | |
| 729 | single step |
| 730 | |
| 731 | =item CLIENT->next() |
| 732 | |
| 733 | step over |
| 734 | |
| 735 | =item CLIENT->done() |
| 736 | |
| 737 | de-register from the debugging API |
| 738 | |
| 739 | =back |
| 740 | |
| 741 | =head2 Client Callback Methods |
| 742 | |
| 743 | The following "virtual" methods can be defined by the client. They will |
| 744 | be called by the API at appropriate points. Note that unless specified |
| 745 | otherwise, the debug API only defines empty, non-functional default versions |
| 746 | of these methods. |
| 747 | |
| 748 | =over 8 |
| 749 | |
| 750 | =item CLIENT->init() |
| 751 | |
| 752 | Called after debug API inits itself. |
| 753 | |
| 754 | =item CLIENT->prestop([STRING]) |
| 755 | |
| 756 | Usually inherited from DB package. If no arguments are passed, |
| 757 | returns the prestop action string. |
| 758 | |
| 759 | =item CLIENT->stop() |
| 760 | |
| 761 | Called when execution stops (w/ args file, line). |
| 762 | |
| 763 | =item CLIENT->idle() |
| 764 | |
| 765 | Called while stopped (can be a client event loop). |
| 766 | |
| 767 | =item CLIENT->poststop([STRING]) |
| 768 | |
| 769 | Usually inherited from DB package. If no arguments are passed, |
| 770 | returns the poststop action string. |
| 771 | |
| 772 | =item CLIENT->evalcode(STRING) |
| 773 | |
| 774 | Usually inherited from DB package. Ask for a STRING to be C<eval>-ed |
| 775 | in executing code context. |
| 776 | |
| 777 | =item CLIENT->cleanup() |
| 778 | |
| 779 | Called just before exit. |
| 780 | |
| 781 | =item CLIENT->output(LIST) |
| 782 | |
| 783 | Called when API must show a message (warnings, errors etc.). |
| 784 | |
| 785 | |
| 786 | =back |
| 787 | |
| 788 | |
| 789 | =head1 BUGS |
| 790 | |
| 791 | The interface defined by this module is missing some of the later additions |
| 792 | to perl's debugging functionality. As such, this interface should be considered |
| 793 | highly experimental and subject to change. |
| 794 | |
| 795 | =head1 AUTHOR |
| 796 | |
| 6e238990 |
797 | Gurusamy Sarathy gsar@activestate.com |
| 43d8869b |
798 | |
| 799 | This code heavily adapted from an early version of perl5db.pl attributable |
| 800 | to Larry Wall and the Perl Porters. |
| 801 | |
| 802 | =cut |
projects / p5sagit/p5-mst-13.2.git / blame