| 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 |
|
| 97 |
# we need to check for pseudofiles on Mac OS (these are files |
| 98 |
# not attached to a filename, but instead stored in Dev:Pseudo) |
| 99 |
# since this is done late, $DB::filename will be "wrong" after |
| 100 |
# skippkg |
| 101 |
if ($^O eq 'MacOS' && $#DB::dbline < 0) { |
| 102 |
$DB::filename = 'Dev:Pseudo'; |
| 103 |
*DB::dbline = "::_<$DB::filename"; |
| 104 |
} |
| 105 |
|
| 106 |
my ($stop, $action); |
| 107 |
if (($stop,$action) = split(/\0/,$DB::dbline{$DB::lineno})) { |
| 108 |
if ($stop eq '1') { |
| 109 |
$DB::signal |= 1; |
| 110 |
} |
| 111 |
else { |
| 112 |
$stop = 0 unless $stop; # avoid un_init warning |
| 113 |
$evalarg = "\$DB::signal |= do { $stop; }"; &eval; |
| 114 |
$DB::dbline{$DB::lineno} =~ s/;9($|\0)/$1/; # clear any temp breakpt |
| 115 |
} |
| 116 |
} |
| 117 |
if ($DB::single || $DB::trace || $DB::signal) { |
| 118 |
$DB::subname = ($DB::sub =~ /\'|::/) ? $DB::sub : "${DB::package}::$DB::sub"; #'; |
| 119 |
DB->loadfile($DB::filename, $DB::lineno); |
| 120 |
} |
| 121 |
$evalarg = $action, &eval if $action; |
| 122 |
if ($DB::single || $DB::signal) { |
| 123 |
_outputall($#stack . " levels deep in subroutine calls.\n") if $DB::single & 4; |
| 124 |
$DB::single = 0; |
| 125 |
$DB::signal = 0; |
| 126 |
$running = 0; |
| 127 |
|
| 128 |
&eval if ($evalarg = DB->prestop); |
| 129 |
my $c; |
| 130 |
for $c (@clients) { |
| 131 |
# perform any client-specific prestop actions |
| 132 |
&eval if ($evalarg = $c->cprestop); |
| 133 |
|
| 134 |
# Now sit in an event loop until something sets $running |
| 135 |
do { |
| 136 |
$c->idle; # call client event loop; must not block |
| 137 |
if ($running == 2) { # client wants something eval-ed |
| 138 |
&eval if ($evalarg = $c->evalcode); |
| 139 |
$running = 0; |
| 140 |
} |
| 141 |
} until $running; |
| 142 |
|
| 143 |
# perform any client-specific poststop actions |
| 144 |
&eval if ($evalarg = $c->cpoststop); |
| 145 |
} |
| 146 |
&eval if ($evalarg = DB->poststop); |
| 147 |
} |
| 148 |
($@, $!, $,, $/, $\, $^W) = @saved; |
| 149 |
(); |
| 150 |
} |
| 151 |
|
| 152 |
#### |
| 153 |
# this takes its argument via $evalarg to preserve current @_ |
| 154 |
# |
| 155 |
sub eval { |
| 156 |
($@, $!, $,, $/, $\, $^W) = @saved; |
| 157 |
eval "$usrctxt $evalarg; &DB::save"; |
| 158 |
_outputall($@) if $@; |
| 159 |
} |
| 160 |
|
| 161 |
############################################################################### |
| 162 |
# no compile-time subroutine call allowed before this point # |
| 163 |
############################################################################### |
| 164 |
|
| 165 |
use strict; # this can run only after DB() and sub() are defined |
| 166 |
|
| 167 |
sub save { |
| 168 |
@saved = ($@, $!, $,, $/, $\, $^W); |
| 169 |
$, = ""; $/ = "\n"; $\ = ""; $^W = 0; |
| 170 |
} |
| 171 |
|
| 172 |
sub catch { |
| 173 |
for (@clients) { $_->awaken; } |
| 174 |
$DB::signal = 1; |
| 175 |
$ready = 1; |
| 176 |
} |
| 177 |
|
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#### |
| 179 |
# |
| 180 |
# Client callable (read inheritable) methods defined after this point |
| 181 |
# |
| 182 |
#### |
| 183 |
|
| 184 |
sub register { |
| 185 |
my $s = shift; |
| 186 |
$s = _clientname($s) if ref($s); |
| 187 |
push @clients, $s; |
| 188 |
} |
| 189 |
|
| 190 |
sub done { |
| 191 |
my $s = shift; |
| 192 |
$s = _clientname($s) if ref($s); |
| 193 |
@clients = grep {$_ ne $s} @clients; |
| 194 |
$s->cleanup; |
| 195 |
# $running = 3 unless @clients; |
| 196 |
exit(0) unless @clients; |
| 197 |
} |
| 198 |
|
| 199 |
sub _clientname { |
| 200 |
my $name = shift; |
| 201 |
"$name" =~ /^(.+)=[A-Z]+\(.+\)$/; |
| 202 |
return $1; |
| 203 |
} |
| 204 |
|
| 205 |
sub next { |
| 206 |
my $s = shift; |
| 207 |
$DB::single = 2; |
| 208 |
$running = 1; |
| 209 |
} |
| 210 |
|
| 211 |
sub step { |
| 212 |
my $s = shift; |
| 213 |
$DB::single = 1; |
| 214 |
$running = 1; |
| 215 |
} |
| 216 |
|
| 217 |
sub cont { |
| 218 |
my $s = shift; |
| 219 |
my $i = shift; |
| 220 |
$s->set_tbreak($i) if $i; |
| 221 |
for ($i = 0; $i <= $#stack;) { |
| 222 |
$stack[$i++] &= ~1; |
| 223 |
} |
| 224 |
$DB::single = 0; |
| 225 |
$running = 1; |
| 226 |
} |
| 227 |
|
| 228 |
#### |
| 229 |
# XXX caller must experimentally determine $i (since it depends |
| 230 |
# on how many client call frames are between this call and the DB call). |
| 231 |
# Such is life. |
| 232 |
# |
| 233 |
sub ret { |
| 234 |
my $s = shift; |
| 235 |
my $i = shift; # how many levels to get to DB sub |
| 236 |
$i = 0 unless defined $i; |
| 237 |
$stack[$#stack-$i] |= 1; |
| 238 |
$DB::single = 0; |
| 239 |
$running = 1; |
| 240 |
} |
| 241 |
|
| 242 |
#### |
| 243 |
# XXX caller must experimentally determine $start (since it depends |
| 244 |
# on how many client call frames are between this call and the DB call). |
| 245 |
# Such is life. |
| 246 |
# |
| 247 |
sub backtrace { |
| 248 |
my $self = shift; |
| 249 |
my $start = shift; |
| 250 |
my($p,$f,$l,$s,$h,$w,$e,$r,$a, @a, @ret,$i); |
| 251 |
$start = 1 unless $start; |
| 252 |
for ($i = $start; ($p,$f,$l,$s,$h,$w,$e,$r) = caller($i); $i++) { |
| 253 |
@a = @DB::args; |
| 254 |
for (@a) { |
| 255 |
s/'/\\'/g; |
| 256 |
s/([^\0]*)/'$1'/ unless /^-?[\d.]+$/; |
| 257 |
s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg; |
| 258 |
s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg; |
| 259 |
} |
| 260 |
$w = $w ? '@ = ' : '$ = '; |
| 261 |
$a = $h ? '(' . join(', ', @a) . ')' : ''; |
| 262 |
$e =~ s/\n\s*\;\s*\Z// if $e; |
| 263 |
$e =~ s/[\\\']/\\$1/g if $e; |
| 264 |
if ($r) { |
| 265 |
$s = "require '$e'"; |
| 266 |
} elsif (defined $r) { |
| 267 |
$s = "eval '$e'"; |
| 268 |
} elsif ($s eq '(eval)') { |
| 269 |
$s = "eval {...}"; |
| 270 |
} |
| 271 |
$f = "file `$f'" unless $f eq '-e'; |
| 272 |
push @ret, "$w&$s$a from $f line $l"; |
| 273 |
last if $DB::signal; |
| 274 |
} |
| 275 |
return @ret; |
| 276 |
} |
| 277 |
|
| 278 |
sub _outputall { |
| 279 |
my $c; |
| 280 |
for $c (@clients) { |
| 281 |
$c->output(@_); |
| 282 |
} |
| 283 |
} |
| 284 |
|
| 285 |
sub trace_toggle { |
| 286 |
my $s = shift; |
| 287 |
$DB::trace = !$DB::trace; |
| 288 |
} |
| 289 |
|
| 290 |
|
| 291 |
#### |
| 292 |
# without args: returns all defined subroutine names |
| 293 |
# with subname args: returns a listref [file, start, end] |
| 294 |
# |
| 295 |
sub subs { |
| 296 |
my $s = shift; |
| 297 |
if (@_) { |
| 298 |
my(@ret) = (); |
| 299 |
while (@_) { |
| 300 |
my $name = shift; |
| 301 |
push @ret, [$DB::sub{$name} =~ /^(.*)\:(\d+)-(\d+)$/] |
| 302 |
if exists $DB::sub{$name}; |
| 303 |
} |
| 304 |
return @ret; |
| 305 |
} |
| 306 |
return keys %DB::sub; |
| 307 |
} |
| 308 |
|
| 309 |
#### |
| 310 |
# first argument is a filename whose subs will be returned |
| 311 |
# if a filename is not supplied, all subs in the current |
| 312 |
# filename are returned. |
| 313 |
# |
| 314 |
sub filesubs { |
| 315 |
my $s = shift; |
| 316 |
my $fname = shift; |
| 317 |
$fname = $DB::filename unless $fname; |
| 318 |
return grep { $DB::sub{$_} =~ /^$fname/ } keys %DB::sub; |
| 319 |
} |
| 320 |
|
| 321 |
#### |
| 322 |
# returns a list of all filenames that DB knows about |
| 323 |
# |
| 324 |
sub files { |
| 325 |
my $s = shift; |
| 326 |
my(@f) = grep(m|^_<|, keys %main::); |
| 327 |
return map { substr($_,2) } @f; |
| 328 |
} |
| 329 |
|
| 330 |
#### |
| 331 |
# returns reference to an array holding the lines in currently |
| 332 |
# loaded file |
| 333 |
# |
| 334 |
sub lines { |
| 335 |
my $s = shift; |
| 336 |
return \@DB::dbline; |
| 337 |
} |
| 338 |
|
| 339 |
#### |
| 340 |
# loadfile($file, $line) |
| 341 |
# |
| 342 |
sub loadfile { |
| 343 |
my $s = shift; |
| 344 |
my($file, $line) = @_; |
| 345 |
if (!defined $main::{'_<' . $file}) { |
| 346 |
my $try; |
| 347 |
if (($try) = grep(m|^_<.*$file|, keys %main::)) { |
| 348 |
$file = substr($try,2); |
| 349 |
} |
| 350 |
} |
| 351 |
if (defined($main::{'_<' . $file})) { |
| 352 |
my $c; |
| 353 |
# _outputall("Loading file $file.."); |
| 354 |
*DB::dbline = "::_<$file"; |
| 355 |
$DB::filename = $file; |
| 356 |
for $c (@clients) { |
| 357 |
# print "2 ", $file, '|', $line, "\n"; |
| 358 |
$c->showfile($file, $line); |
| 359 |
} |
| 360 |
return $file; |
| 361 |
} |
| 362 |
return undef; |
| 363 |
} |
| 364 |
|
| 365 |
sub lineevents { |
| 366 |
my $s = shift; |
| 367 |
my $fname = shift; |
| 368 |
my(%ret) = (); |
| 369 |
my $i; |
| 370 |
$fname = $DB::filename unless $fname; |
| 371 |
local(*DB::dbline) = "::_<$fname"; |
| 372 |
for ($i = 1; $i <= $#DB::dbline; $i++) { |
| 373 |
$ret{$i} = [$DB::dbline[$i], split(/\0/, $DB::dbline{$i})] |
| 374 |
if defined $DB::dbline{$i}; |
| 375 |
} |
| 376 |
return %ret; |
| 377 |
} |
| 378 |
|
| 379 |
sub set_break { |
| 380 |
my $s = shift; |
| 381 |
my $i = shift; |
| 382 |
my $cond = shift; |
| 383 |
$i ||= $DB::lineno; |
| 384 |
$cond ||= '1'; |
| 385 |
$i = _find_subline($i) if ($i =~ /\D/); |
| 386 |
$s->output("Subroutine not found.\n") unless $i; |
| 387 |
if ($i) { |
| 388 |
if ($DB::dbline[$i] == 0) { |
| 389 |
$s->output("Line $i not breakable.\n"); |
| 390 |
} |
| 391 |
else { |
| 392 |
$DB::dbline{$i} =~ s/^[^\0]*/$cond/; |
| 393 |
} |
| 394 |
} |
| 395 |
} |
| 396 |
|
| 397 |
sub set_tbreak { |
| 398 |
my $s = shift; |
| 399 |
my $i = shift; |
| 400 |
$i = _find_subline($i) if ($i =~ /\D/); |
| 401 |
$s->output("Subroutine not found.\n") unless $i; |
| 402 |
if ($i) { |
| 403 |
if ($DB::dbline[$i] == 0) { |
| 404 |
$s->output("Line $i not breakable.\n"); |
| 405 |
} |
| 406 |
else { |
| 407 |
$DB::dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p. |
| 408 |
} |
| 409 |
} |
| 410 |
} |
| 411 |
|
| 412 |
sub _find_subline { |
| 413 |
my $name = shift; |
| 414 |
$name =~ s/\'/::/; |
| 415 |
$name = "${DB::package}\:\:" . $name if $name !~ /::/; |
| 416 |
$name = "main" . $name if substr($name,0,2) eq "::"; |
| 417 |
my($fname, $from, $to) = ($DB::sub{$name} =~ /^(.*):(\d+)-(\d+)$/); |
| 418 |
if ($from) { |
| 419 |
local *DB::dbline = "::_<$fname"; |
| 420 |
++$from while $DB::dbline[$from] == 0 && $from < $to; |
| 421 |
return $from; |
| 422 |
} |
| 423 |
return undef; |
| 424 |
} |
| 425 |
|
| 426 |
sub clr_breaks { |
| 427 |
my $s = shift; |
| 428 |
my $i; |
| 429 |
if (@_) { |
| 430 |
while (@_) { |
| 431 |
$i = shift; |
| 432 |
$i = _find_subline($i) if ($i =~ /\D/); |
| 433 |
$s->output("Subroutine not found.\n") unless $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 |
else { |
| 443 |
for ($i = 1; $i <= $#DB::dbline ; $i++) { |
| 444 |
if (defined $DB::dbline{$i}) { |
| 445 |
$DB::dbline{$i} =~ s/^[^\0]+//; |
| 446 |
if ($DB::dbline{$i} =~ s/^\0?$//) { |
| 447 |
delete $DB::dbline{$i}; |
| 448 |
} |
| 449 |
} |
| 450 |
} |
| 451 |
} |
| 452 |
} |
| 453 |
|
| 454 |
sub set_action { |
| 455 |
my $s = shift; |
| 456 |
my $i = shift; |
| 457 |
my $act = shift; |
| 458 |
$i = _find_subline($i) if ($i =~ /\D/); |
| 459 |
$s->output("Subroutine not found.\n") unless $i; |
| 460 |
if ($i) { |
| 461 |
if ($DB::dbline[$i] == 0) { |
| 462 |
$s->output("Line $i not actionable.\n"); |
| 463 |
} |
| 464 |
else { |
| 465 |
$DB::dbline{$i} =~ s/\0[^\0]*//; |
| 466 |
$DB::dbline{$i} .= "\0" . $act; |
| 467 |
} |
| 468 |
} |
| 469 |
} |
| 470 |
|
| 471 |
sub clr_actions { |
| 472 |
my $s = shift; |
| 473 |
my $i; |
| 474 |
if (@_) { |
| 475 |
while (@_) { |
| 476 |
my $i = shift; |
| 477 |
$i = _find_subline($i) if ($i =~ /\D/); |
| 478 |
$s->output("Subroutine not found.\n") unless $i; |
| 479 |
if ($i && $DB::dbline[$i] != 0) { |
| 480 |
$DB::dbline{$i} =~ s/\0[^\0]*//; |
| 481 |
delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; |
| 482 |
} |
| 483 |
} |
| 484 |
} |
| 485 |
else { |
| 486 |
for ($i = 1; $i <= $#DB::dbline ; $i++) { |
| 487 |
if (defined $DB::dbline{$i}) { |
| 488 |
$DB::dbline{$i} =~ s/\0[^\0]*//; |
| 489 |
delete $DB::dbline{$i} if $DB::dbline{$i} =~ s/^\0?$//; |
| 490 |
} |
| 491 |
} |
| 492 |
} |
| 493 |
} |
| 494 |
|
| 495 |
sub prestop { |
| 496 |
my ($client, $val) = @_; |
| 497 |
return defined($val) ? $preeval->{$client} = $val : $preeval->{$client}; |
| 498 |
} |
| 499 |
|
| 500 |
sub poststop { |
| 501 |
my ($client, $val) = @_; |
| 502 |
return defined($val) ? $posteval->{$client} = $val : $posteval->{$client}; |
| 503 |
} |
| 504 |
|
| 505 |
# |
| 506 |
# "pure virtual" methods |
| 507 |
# |
| 508 |
|
| 509 |
# client-specific pre/post-stop actions. |
| 510 |
sub cprestop {} |
| 511 |
sub cpoststop {} |
| 512 |
|
| 513 |
# client complete startup |
| 514 |
sub awaken {} |
| 515 |
|
| 516 |
sub skippkg { |
| 517 |
my $s = shift; |
| 518 |
push @skippkg, @_ if @_; |
| 519 |
} |
| 520 |
|
| 521 |
sub evalcode { |
| 522 |
my ($client, $val) = @_; |
| 523 |
if (defined $val) { |
| 524 |
$running = 2; # hand over to DB() to evaluate in its context |
| 525 |
$ineval->{$client} = $val; |
| 526 |
} |
| 527 |
return $ineval->{$client}; |
| 528 |
} |
| 529 |
|
| 530 |
sub ready { |
| 531 |
my $s = shift; |
| 532 |
return $ready = 1; |
| 533 |
} |
| 534 |
|
| 535 |
# stubs |
| 536 |
|
| 537 |
sub init {} |
| 538 |
sub stop {} |
| 539 |
sub idle {} |
| 540 |
sub cleanup {} |
| 541 |
sub output {} |
| 542 |
|
| 543 |
# |
| 544 |
# client init |
| 545 |
# |
| 546 |
for (@clients) { $_->init } |
| 547 |
|
| 548 |
$SIG{'INT'} = \&DB::catch; |
| 549 |
|
| 550 |
# disable this if stepping through END blocks is desired |
| 551 |
# (looks scary and deconstructivist with Swat) |
| 552 |
END { $ready = 0 } |
| 553 |
|
| 554 |
1; |
| 555 |
__END__ |
| 556 |
|
| 557 |
=head1 NAME |
| 558 |
|
| 559 |
DB - programmatic interface to the Perl debugging API (draft, subject to |
| 560 |
change) |
| 561 |
|
| 562 |
=head1 SYNOPSIS |
| 563 |
|
| 564 |
package CLIENT; |
| 565 |
use DB; |
| 566 |
@ISA = qw(DB); |
| 567 |
|
| 568 |
# these (inherited) methods can be called by the client |
| 569 |
|
| 570 |
CLIENT->register() # register a client package name |
| 571 |
CLIENT->done() # de-register from the debugging API |
| 572 |
CLIENT->skippkg('hide::hide') # ask DB not to stop in this package |
| 573 |
CLIENT->cont([WHERE]) # run some more (until BREAK or another breakpt) |
| 574 |
CLIENT->step() # single step |
| 575 |
CLIENT->next() # step over |
| 576 |
CLIENT->ret() # return from current subroutine |
| 577 |
CLIENT->backtrace() # return the call stack description |
| 578 |
CLIENT->ready() # call when client setup is done |
| 579 |
CLIENT->trace_toggle() # toggle subroutine call trace mode |
| 580 |
CLIENT->subs([SUBS]) # return subroutine information |
| 581 |
CLIENT->files() # return list of all files known to DB |
| 582 |
CLIENT->lines() # return lines in currently loaded file |
| 583 |
CLIENT->loadfile(FILE,LINE) # load a file and let other clients know |
| 584 |
CLIENT->lineevents() # return info on lines with actions |
| 585 |
CLIENT->set_break([WHERE],[COND]) |
| 586 |
CLIENT->set_tbreak([WHERE]) |
| 587 |
CLIENT->clr_breaks([LIST]) |
| 588 |
CLIENT->set_action(WHERE,ACTION) |
| 589 |
CLIENT->clr_actions([LIST]) |
| 590 |
CLIENT->evalcode(STRING) # eval STRING in executing code's context |
| 591 |
CLIENT->prestop([STRING]) # execute in code context before stopping |
| 592 |
CLIENT->poststop([STRING])# execute in code context before resuming |
| 593 |
|
| 594 |
# These methods will be called at the appropriate times. |
| 595 |
# Stub versions provided do nothing. |
| 596 |
# None of these can block. |
| 597 |
|
| 598 |
CLIENT->init() # called when debug API inits itself |
| 599 |
CLIENT->stop(FILE,LINE) # when execution stops |
| 600 |
CLIENT->idle() # while stopped (can be a client event loop) |
| 601 |
CLIENT->cleanup() # just before exit |
| 602 |
CLIENT->output(LIST) # called to print any output that API must show |
| 603 |
|
| 604 |
=head1 DESCRIPTION |
| 605 |
|
| 606 |
Perl debug information is frequently required not just by debuggers, |
| 607 |
but also by modules that need some "special" information to do their |
| 608 |
job properly, like profilers. |
| 609 |
|
| 610 |
This module abstracts and provides all of the hooks into Perl internal |
| 611 |
debugging functionality, so that various implementations of Perl debuggers |
| 612 |
(or packages that want to simply get at the "privileged" debugging data) |
| 613 |
can all benefit from the development of this common code. Currently used |
| 614 |
by Swat, the perl/Tk GUI debugger. |
| 615 |
|
| 616 |
Note that multiple "front-ends" can latch into this debugging API |
| 617 |
simultaneously. This is intended to facilitate things like |
| 618 |
debugging with a command line and GUI at the same time, debugging |
| 619 |
debuggers etc. [Sounds nice, but this needs some serious support -- GSAR] |
| 620 |
|
| 621 |
In particular, this API does B<not> provide the following functions: |
| 622 |
|
| 623 |
=over 4 |
| 624 |
|
| 625 |
=item * |
| 626 |
|
| 627 |
data display |
| 628 |
|
| 629 |
=item * |
| 630 |
|
| 631 |
command processing |
| 632 |
|
| 633 |
=item * |
| 634 |
|
| 635 |
command alias management |
| 636 |
|
| 637 |
=item * |
| 638 |
|
| 639 |
user interface (tty or graphical) |
| 640 |
|
| 641 |
=back |
| 642 |
|
| 643 |
These are intended to be services performed by the clients of this API. |
| 644 |
|
| 645 |
This module attempts to be squeaky clean w.r.t C<use strict;> and when |
| 646 |
warnings are enabled. |
| 647 |
|
| 648 |
|
| 649 |
=head2 Global Variables |
| 650 |
|
| 651 |
The following "public" global names can be read by clients of this API. |
| 652 |
Beware that these should be considered "readonly". |
| 653 |
|
| 654 |
=over 8 |
| 655 |
|
| 656 |
=item $DB::sub |
| 657 |
|
| 658 |
Name of current executing subroutine. |
| 659 |
|
| 660 |
=item %DB::sub |
| 661 |
|
| 662 |
The keys of this hash are the names of all the known subroutines. Each value |
| 663 |
is an encoded string that has the sprintf(3) format |
| 664 |
C<("%s:%d-%d", filename, fromline, toline)>. |
| 665 |
|
| 666 |
=item $DB::single |
| 667 |
|
| 668 |
Single-step flag. Will be true if the API will stop at the next statement. |
| 669 |
|
| 670 |
=item $DB::signal |
| 671 |
|
| 672 |
Signal flag. Will be set to a true value if a signal was caught. Clients may |
| 673 |
check for this flag to abort time-consuming operations. |
| 674 |
|
| 675 |
=item $DB::trace |
| 676 |
|
| 677 |
This flag is set to true if the API is tracing through subroutine calls. |
| 678 |
|
| 679 |
=item @DB::args |
| 680 |
|
| 681 |
Contains the arguments of current subroutine, or the C<@ARGV> array if in the |
| 682 |
toplevel context. |
| 683 |
|
| 684 |
=item @DB::dbline |
| 685 |
|
| 686 |
List of lines in currently loaded file. |
| 687 |
|
| 688 |
=item %DB::dbline |
| 689 |
|
| 690 |
Actions in current file (keys are line numbers). The values are strings that |
| 691 |
have the sprintf(3) format C<("%s\000%s", breakcondition, actioncode)>. |
| 692 |
|
| 693 |
=item $DB::package |
| 694 |
|
| 695 |
Package namespace of currently executing code. |
| 696 |
|
| 697 |
=item $DB::filename |
| 698 |
|
| 699 |
Currently loaded filename. |
| 700 |
|
| 701 |
=item $DB::subname |
| 702 |
|
| 703 |
Fully qualified name of currently executing subroutine. |
| 704 |
|
| 705 |
=item $DB::lineno |
| 706 |
|
| 707 |
Line number that will be executed next. |
| 708 |
|
| 709 |
=back |
| 710 |
|
| 711 |
=head2 API Methods |
| 712 |
|
| 713 |
The following are methods in the DB base class. A client must |
| 714 |
access these methods by inheritance (*not* by calling them directly), |
| 715 |
since the API keeps track of clients through the inheritance |
| 716 |
mechanism. |
| 717 |
|
| 718 |
=over 8 |
| 719 |
|
| 720 |
=item CLIENT->register() |
| 721 |
|
| 722 |
register a client object/package |
| 723 |
|
| 724 |
=item CLIENT->evalcode(STRING) |
| 725 |
|
| 726 |
eval STRING in executing code context |
| 727 |
|
| 728 |
=item CLIENT->skippkg('D::hide') |
| 729 |
|
| 730 |
ask DB not to stop in these packages |
| 731 |
|
| 732 |
=item CLIENT->run() |
| 733 |
|
| 734 |
run some more (until a breakpt is reached) |
| 735 |
|
| 736 |
=item CLIENT->step() |
| 737 |
|
| 738 |
single step |
| 739 |
|
| 740 |
=item CLIENT->next() |
| 741 |
|
| 742 |
step over |
| 743 |
|
| 744 |
=item CLIENT->done() |
| 745 |
|
| 746 |
de-register from the debugging API |
| 747 |
|
| 748 |
=back |
| 749 |
|
| 750 |
=head2 Client Callback Methods |
| 751 |
|
| 752 |
The following "virtual" methods can be defined by the client. They will |
| 753 |
be called by the API at appropriate points. Note that unless specified |
| 754 |
otherwise, the debug API only defines empty, non-functional default versions |
| 755 |
of these methods. |
| 756 |
|
| 757 |
=over 8 |
| 758 |
|
| 759 |
=item CLIENT->init() |
| 760 |
|
| 761 |
Called after debug API inits itself. |
| 762 |
|
| 763 |
=item CLIENT->prestop([STRING]) |
| 764 |
|
| 765 |
Usually inherited from DB package. If no arguments are passed, |
| 766 |
returns the prestop action string. |
| 767 |
|
| 768 |
=item CLIENT->stop() |
| 769 |
|
| 770 |
Called when execution stops (w/ args file, line). |
| 771 |
|
| 772 |
=item CLIENT->idle() |
| 773 |
|
| 774 |
Called while stopped (can be a client event loop). |
| 775 |
|
| 776 |
=item CLIENT->poststop([STRING]) |
| 777 |
|
| 778 |
Usually inherited from DB package. If no arguments are passed, |
| 779 |
returns the poststop action string. |
| 780 |
|
| 781 |
=item CLIENT->evalcode(STRING) |
| 782 |
|
| 783 |
Usually inherited from DB package. Ask for a STRING to be C<eval>-ed |
| 784 |
in executing code context. |
| 785 |
|
| 786 |
=item CLIENT->cleanup() |
| 787 |
|
| 788 |
Called just before exit. |
| 789 |
|
| 790 |
=item CLIENT->output(LIST) |
| 791 |
|
| 792 |
Called when API must show a message (warnings, errors etc.). |
| 793 |
|
| 794 |
|
| 795 |
=back |
| 796 |
|
| 797 |
|
| 798 |
=head1 BUGS |
| 799 |
|
| 800 |
The interface defined by this module is missing some of the later additions |
| 801 |
to perl's debugging functionality. As such, this interface should be considered |
| 802 |
highly experimental and subject to change. |
| 803 |
|
| 804 |
=head1 AUTHOR |
| 805 |
|
| 806 |
Gurusamy Sarathy gsar@activestate.com |
| 807 |
|
| 808 |
This code heavily adapted from an early version of perl5db.pl attributable |
| 809 |
to Larry Wall and the Perl Porters. |
| 810 |
|
| 811 |
=cut |
