lib/perl5db.pl

   1 package DB;
   2
   3 # modified Perl debugger, to be run from Emacs in perldb-mode
   4 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
   5 # Johan Vromans -- upgrade to 4.0 pl 10
   6
   7 $header = '$RCSfile: perl5db.pl,v $$Revision: 4.1 $$Date: 92/08/07 18:24:07 $';
   8 #
   9 # This file is automatically included if you do perl -d.
  10 # It's probably not useful to include this yourself.
  11 #
  12 # Perl supplies the values for @line and %sub.  It effectively inserts
  13 # a &DB'DB(<linenum>); in front of every place that can
  14 # have a breakpoint.  It also inserts a do 'perldb.pl' before the first line.
  15 #
  16 # $Log: perldb.pl,v $
  17
  18 local($^W) = 0;
  19
  20 if (-e "/dev/tty") {
  21     $console = "/dev/tty";
  22     $rcfile=".perldb";
  23 }
  24 elsif (-e "con") {
  25     $console = "con";
  26     $rcfile="perldb.ini";
  27 }
  28 else {
  29     $console = "sys\$command";
  30     $rcfile="perldb.ini";
  31 }
  32
  33 open(IN, "<$console") || open(IN,  "<&STDIN");  # so we don't dingle stdin
  34 open(OUT,">$console") || open(OUT, ">&STDERR")
  35     || open(OUT, ">&STDOUT");   # so we don't dongle stdout
  36 select(OUT);
  37 $| = 1;                         # for DB::OUT
  38 select(STDOUT);
  39 $| = 1;                         # for real STDOUT
  40 $sub = '';
  41
  42 # Is Perl being run from Emacs?
  43 $emacs = $main::ARGV[0] eq '-emacs';
  44 shift(@main::ARGV) if $emacs;
  45
  46 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
  47 print OUT "\nLoading DB routines from $header\n";
  48 print OUT ("Emacs support ",
  49            $emacs ? "enabled" : "available",
  50            ".\n");
  51 print OUT "\nEnter h for help.\n\n";
  52
  53 sub DB {
  54     &save;
  55     ($package, $filename, $line) = caller;
  56     $usercontext = '($@, $!, $,, $/, $\, $^W) = @saved;' .
  57         "package $package;";            # this won't let them modify, alas
  58     local(*dbline) = "::_<$filename";
  59     $max = $#dbline;
  60     if (($stop,$action) = split(/\0/,$dbline{$line})) {
  61         if ($stop eq '1') {
  62             $signal |= 1;
  63         }
  64         else {
  65             $evalarg = "\$DB::signal |= do {$stop;}"; &eval;
  66             $dbline{$line} =~ s/;9($|\0)/$1/;
  67         }
  68     }
  69     if ($single || $trace || $signal) {
  70         if ($emacs) {
  71             print OUT "\032\032$filename:$line:0\n";
  72         } else {
  73             $prefix = $sub =~ /'|::/ ? "" : "${package}::";
  74             $prefix .= "$sub($filename:";
  75             if (length($prefix) > 30) {
  76                 print OUT "$prefix$line):\n$line:\t",$dbline[$line];
  77                 $prefix = "";
  78                 $infix = ":\t";
  79             }
  80             else {
  81                 $infix = "):\t";
  82                 print OUT "$prefix$line$infix",$dbline[$line];
  83             }
  84             for ($i = $line + 1; $i <= $max && $dbline[$i] == 0; ++$i) {
  85                 last if $dbline[$i] =~ /^\s*(}|#|\n)/;
  86                 print OUT "$prefix$i$infix",$dbline[$i];
  87             }
  88         }
  89     }
  90     $evalarg = $action, &eval if $action;
  91     if ($single || $signal) {
  92         $evalarg = $pre, &eval if $pre;
  93         print OUT $#stack . " levels deep in subroutine calls!\n"
  94             if $single & 4;
  95         $start = $line;
  96       CMD:
  97         while ((print OUT "  DB<", $#hist+1, "> "), $cmd=&gets) {
  98             {
  99                 $single = 0;
 100                 $signal = 0;
 101                 $cmd eq '' && exit 0;
 102                 chop($cmd);
 103                 $cmd =~ s/\\$// && do {
 104                     print OUT "  cont: ";
 105                     $cmd .= &gets;
 106                     redo CMD;
 107                 };
 108                 $cmd =~ /^q$/ && exit 0;
 109                 $cmd =~ /^$/ && ($cmd = $laststep);
 110                 push(@hist,$cmd) if length($cmd) > 1;
 111                 ($i) = split(/\s+/,$cmd);
 112                 eval "\$cmd =~ $alias{$i}", print OUT $@ if $alias{$i};
 113                 $cmd =~ /^h$/ && do {
 114                     print OUT "
 115 T               Stack trace.
 116 s               Single step.
 117 n               Next, steps over subroutine calls.
 118 r               Return from current subroutine.
 119 c [line]        Continue; optionally inserts a one-time-only breakpoint
 120                 at the specified line.
 121 <CR>            Repeat last n or s.
 122 l min+incr      List incr+1 lines starting at min.
 123 l min-max       List lines.
 124 l line          List line;
 125 l               List next window.
 126 -               List previous window.
 127 w line          List window around line.
 128 l subname       List subroutine.
 129 f filename      Switch to filename.
 130 /pattern/       Search forwards for pattern; final / is optional.
 131 ?pattern?       Search backwards for pattern.
 132 L               List breakpoints and actions.
 133 S               List subroutine names.
 134 t               Toggle trace mode.
 135 b [line] [condition]
 136                 Set breakpoint; line defaults to the current execution line;
 137                 condition breaks if it evaluates to true, defaults to \'1\'.
 138 b subname [condition]
 139                 Set breakpoint at first line of subroutine.
 140 d [line]        Delete breakpoint.
 141 D               Delete all breakpoints.
 142 a [line] command
 143                 Set an action to be done before the line is executed.
 144                 Sequence is: check for breakpoint, print line if necessary,
 145                 do action, prompt user if breakpoint or step, evaluate line.
 146 A               Delete all actions.
 147 V [pkg [vars]]  List some (default all) variables in package (default current).
 148 X [vars]        Same as \"V currentpackage [vars]\".
 149 < command       Define command before prompt.
 150 > command       Define command after prompt.
 151 ! number        Redo command (default previous command).
 152 ! -number       Redo number\'th to last command.
 153 H -number       Display last number commands (default all).
 154 q or ^D         Quit.
 155 p expr          Same as \"print DB::OUT expr\" in current package.
 156 = [alias value] Define a command alias, or list current aliases.
 157 command         Execute as a perl statement in current package.
 158
 159 ";
 160                     next CMD; };
 161                 $cmd =~ /^t$/ && do {
 162                     $trace = !$trace;
 163                     print OUT "Trace = ".($trace?"on":"off")."\n";
 164                     next CMD; };
 165                 $cmd =~ /^S$/ && do {
 166                     foreach $subname (sort(keys %sub)) {
 167                         print OUT $subname,"\n";
 168                     }
 169                     next CMD; };
 170                 $cmd =~ s/^X\b/V $package/;
 171                 $cmd =~ /^V$/ && do {
 172                     $cmd = "V $package"; };
 173                 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
 174                     local ($savout) = select(OUT);
 175                     $packname = $1;
 176                     @vars = split(' ',$2);
 177                     do 'dumpvar.pl' unless defined &main::dumpvar;
 178                     if (defined &main::dumpvar) {
 179                         &main::dumpvar($packname,@vars);
 180                     }
 181                     else {
 182                         print DB::OUT "dumpvar.pl not available.\n";
 183                     }
 184                     select ($savout);
 185                     next CMD; };
 186                 $cmd =~ /^f\b\s*(.*)/ && do {
 187                     $file = $1;
 188                     if (!$file) {
 189                         print OUT "The old f command is now the r command.\n";
 190                         print OUT "The new f command switches filenames.\n";
 191                         next CMD;
 192                     }
 193                     if (!defined $main::{'_<' . $file}) {
 194                         if (($try) = grep(m#^_<.*$file#, keys %main::)) {
 195                             $file = substr($try,2);
 196                             print "\n$file:\n";
 197                         }
 198                     }
 199                     if (!defined $main::{'_<' . $file}) {
 200                         print OUT "There's no code here anything matching $file.\n";
 201                         next CMD;
 202                     }
 203                     elsif ($file ne $filename) {
 204                         *dbline = "::_<$file";
 205                         $max = $#dbline;
 206                         $filename = $file;
 207                         $start = 1;
 208                         $cmd = "l";
 209                     } };
 210                 $cmd =~ /^l\b\s*([':A-Za-z_][':\w]*)/ && do {
 211                     $subname = $1;
 212                     $subname = "main::" . $subname unless $subname =~ /'|::/;
 213                     $subname = "main" . $subname if substr($subname,0,1)eq "'";
 214                     $subname = "main" . $subname if substr($subname,0,2)eq "::";
 215                     ($file,$subrange) = split(/:/,$sub{$subname});
 216                     if ($file ne $filename) {
 217                         *dbline = "::_<$file";
 218                         $max = $#dbline;
 219                         $filename = $file;
 220                     }
 221                     if ($subrange) {
 222                         if (eval($subrange) < -$window) {
 223                             $subrange =~ s/-.*/+/;
 224                         }
 225                         $cmd = "l $subrange";
 226                     } else {
 227                         print OUT "Subroutine $1 not found.\n";
 228                         next CMD;
 229                     } };
 230                 $cmd =~ /^w\b\s*(\d*)$/ && do {
 231                     $incr = $window - 1;
 232                     $start = $1 if $1;
 233                     $start -= $preview;
 234                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 235                 $cmd =~ /^-$/ && do {
 236                     $incr = $window - 1;
 237                     $cmd = 'l ' . ($start-$window*2) . '+'; };
 238                 $cmd =~ /^l$/ && do {
 239                     $incr = $window - 1;
 240                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 241                 $cmd =~ /^l\b\s*(\d*)\+(\d*)$/ && do {
 242                     $start = $1 if $1;
 243                     $incr = $2;
 244                     $incr = $window - 1 unless $incr;
 245                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 246                 $cmd =~ /^l\b\s*(([\d\$\.]+)([-,]([\d\$\.]+))?)?/ && do {
 247                     $end = (!$2) ? $max : ($4 ? $4 : $2);
 248                     $end = $max if $end > $max;
 249                     $i = $2;
 250                     $i = $line if $i eq '.';
 251                     $i = 1 if $i < 1;
 252                     if ($emacs) {
 253                         print OUT "\032\032$filename:$i:0\n";
 254                         $i = $end;
 255                     } else {
 256                         for (; $i <= $end; $i++) {
 257                             print OUT "$i:\t", $dbline[$i];
 258                             last if $signal;
 259                         }
 260                     }
 261                     $start = $i;        # remember in case they want more
 262                     $start = $max if $start > $max;
 263                     next CMD; };
 264                 $cmd =~ /^D$/ && do {
 265                     print OUT "Deleting all breakpoints...\n";
 266                     for ($i = 1; $i <= $max ; $i++) {
 267                         if (defined $dbline{$i}) {
 268                             $dbline{$i} =~ s/^[^\0]+//;
 269                             if ($dbline{$i} =~ s/^\0?$//) {
 270                                 delete $dbline{$i};
 271                             }
 272                         }
 273                     }
 274                     next CMD; };
 275                 $cmd =~ /^L$/ && do {
 276                     for ($i = 1; $i <= $max; $i++) {
 277                         if (defined $dbline{$i}) {
 278                             print OUT "$i:\t", $dbline[$i];
 279                             ($stop,$action) = split(/\0/, $dbline{$i});
 280                             print OUT "  break if (", $stop, ")\n"
 281                                 if $stop;
 282                             print OUT "  action:  ", $action, "\n"
 283                                 if $action;
 284                             last if $signal;
 285                         }
 286                     }
 287                     next CMD; };
 288                 $cmd =~ /^b\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ && do {
 289                     $subname = $1;
 290                     $cond = $2 || '1';
 291                     $subname = "${package}::" . $subname
 292                         unless $subname =~ /'|::/;
 293                     $subname = "main" . $subname if substr($subname,0,1) eq "'";
 294                     $subname = "main" . $subname if substr($subname,0,2) eq "::";
 295                     ($filename,$i) = split(/:/, $sub{$subname});
 296                     $i += 0;
 297                     if ($i) {
 298                         *dbline = "::_<$filename";
 299                         ++$i while $dbline[$i] == 0 && $i < $#dbline;
 300                         $dbline{$i} =~ s/^[^\0]*/$cond/;
 301                     } else {
 302                         print OUT "Subroutine $subname not found.\n";
 303                     }
 304                     next CMD; };
 305                 $cmd =~ /^b\b\s*(\d*)\s*(.*)/ && do {
 306                     $i = ($1?$1:$line);
 307                     $cond = $2 || '1';
 308                     if ($dbline[$i] == 0) {
 309                         print OUT "Line $i not breakable.\n";
 310                     } else {
 311                         $dbline{$i} =~ s/^[^\0]*/$cond/;
 312                     }
 313                     next CMD; };
 314                 $cmd =~ /^d\b\s*(\d+)?/ && do {
 315                     $i = ($1?$1:$line);
 316                     $dbline{$i} =~ s/^[^\0]*//;
 317                     delete $dbline{$i} if $dbline{$i} eq '';
 318                     next CMD; };
 319                 $cmd =~ /^A$/ && do {
 320                     for ($i = 1; $i <= $max ; $i++) {
 321                         if (defined $dbline{$i}) {
 322                             $dbline{$i} =~ s/\0[^\0]*//;
 323                             delete $dbline{$i} if $dbline{$i} eq '';
 324                         }
 325                     }
 326                     next CMD; };
 327                 $cmd =~ /^<\s*(.*)/ && do {
 328                     $pre = action($1);
 329                     next CMD; };
 330                 $cmd =~ /^>\s*(.*)/ && do {
 331                     $post = action($1);
 332                     next CMD; };
 333                 $cmd =~ /^a\b\s*(\d+)(\s+(.*))?/ && do {
 334                     $i = $1;
 335                     if ($dbline[$i] == 0) {
 336                         print OUT "Line $i may not have an action.\n";
 337                     } else {
 338                         $dbline{$i} =~ s/\0[^\0]*//;
 339                         $dbline{$i} .= "\0" . action($3);
 340                     }
 341                     next CMD; };
 342                 $cmd =~ /^n$/ && do {
 343                     $single = 2;
 344                     $laststep = $cmd;
 345                     last CMD; };
 346                 $cmd =~ /^s$/ && do {
 347                     $single = 1;
 348                     $laststep = $cmd;
 349                     last CMD; };
 350                 $cmd =~ /^c\b\s*(\d*)\s*$/ && do {
 351                     $i = $1;
 352                     if ($i) {
 353                         if ($dbline[$i] == 0) {
 354                             print OUT "Line $i not breakable.\n";
 355                             next CMD;
 356                         }
 357                         $dbline{$i} =~ s/(\0|$)/;9$1/;  # add one-time-only b.p.
 358                     }
 359                     for ($i=0; $i <= $#stack; ) {
 360                         $stack[$i++] &= ~1;
 361                     }
 362                     last CMD; };
 363                 $cmd =~ /^r$/ && do {
 364                     $stack[$#stack] |= 2;
 365                     last CMD; };
 366                 $cmd =~ /^T$/ && do {
 367                     local($p,$f,$l,$s,$h,$a,@a,@sub);
 368                     for ($i = 1; ($p,$f,$l,$s,$h,$w) = caller($i); $i++) {
 369                         @a = ();
 370                         for $arg (@args) {
 371                             $_ = "$arg";
 372                             s/'/\\'/g;
 373                             s/([^\0]*)/'$1'/
 374                                 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
 375                             s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
 376                             s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
 377                             push(@a, $_);
 378                         }
 379                         $w = $w ? '@ = ' : '$ = ';
 380                         $a = $h ? '(' . join(', ', @a) . ')' : '';
 381                         push(@sub, "$w$s$a from file $f line $l\n");
 382                         last if $signal;
 383                     }
 384                     for ($i=0; $i <= $#sub; $i++) {
 385                         last if $signal;
 386                         print OUT $sub[$i];
 387                     }
 388                     next CMD; };
 389                 $cmd =~ /^\/(.*)$/ && do {
 390                     $inpat = $1;
 391                     $inpat =~ s:([^\\])/$:$1:;
 392                     if ($inpat ne "") {
 393                         eval '$inpat =~ m'."\a$inpat\a";
 394                         if ($@ ne "") {
 395                             print OUT "$@";
 396                             next CMD;
 397                         }
 398                         $pat = $inpat;
 399                     }
 400                     $end = $start;
 401                     eval '
 402                     for (;;) {
 403                         ++$start;
 404                         $start = 1 if ($start > $max);
 405                         last if ($start == $end);
 406                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
 407                             if ($emacs) {
 408                                 print OUT "\032\032$filename:$start:0\n";
 409                             } else {
 410                                 print OUT "$start:\t", $dbline[$start], "\n";
 411                             }
 412                             last;
 413                         }
 414                     } ';
 415                     print OUT "/$pat/: not found\n" if ($start == $end);
 416                     next CMD; };
 417                 $cmd =~ /^\?(.*)$/ && do {
 418                     $inpat = $1;
 419                     $inpat =~ s:([^\\])\?$:$1:;
 420                     if ($inpat ne "") {
 421                         eval '$inpat =~ m'."\a$inpat\a";
 422                         if ($@ ne "") {
 423                             print OUT "$@";
 424                             next CMD;
 425                         }
 426                         $pat = $inpat;
 427                     }
 428                     $end = $start;
 429                     eval '
 430                     for (;;) {
 431                         --$start;
 432                         $start = $max if ($start <= 0);
 433                         last if ($start == $end);
 434                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
 435                             if ($emacs) {
 436                                 print OUT "\032\032$filename:$start:0\n";
 437                             } else {
 438                                 print OUT "$start:\t", $dbline[$start], "\n";
 439                             }
 440                             last;
 441                         }
 442                     } ';
 443                     print OUT "?$pat?: not found\n" if ($start == $end);
 444                     next CMD; };
 445                 $cmd =~ /^!+\s*(-)?(\d+)?$/ && do {
 446                     pop(@hist) if length($cmd) > 1;
 447                     $i = ($1?($#hist-($2?$2:1)):($2?$2:$#hist));
 448                     $cmd = $hist[$i] . "\n";
 449                     print OUT $cmd;
 450                     redo CMD; };
 451                 $cmd =~ /^!(.+)$/ && do {
 452                     $pat = "^$1";
 453                     pop(@hist) if length($cmd) > 1;
 454                     for ($i = $#hist; $i; --$i) {
 455                         last if $hist[$i] =~ $pat;
 456                     }
 457                     if (!$i) {
 458                         print OUT "No such command!\n\n";
 459                         next CMD;
 460                     }
 461                     $cmd = $hist[$i] . "\n";
 462                     print OUT $cmd;
 463                     redo CMD; };
 464                 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
 465                     $end = $2?($#hist-$2):0;
 466                     $hist = 0 if $hist < 0;
 467                     for ($i=$#hist; $i>$end; $i--) {
 468                         print OUT "$i: ",$hist[$i],"\n"
 469                             unless $hist[$i] =~ /^.?$/;
 470                     };
 471                     next CMD; };
 472                 $cmd =~ s/^p( .*)?$/print DB::OUT$1/;
 473                 $cmd =~ /^=/ && do {
 474                     if (local($k,$v) = ($cmd =~ /^=\s*(\S+)\s+(.*)/)) {
 475                         $alias{$k}="s~$k~$v~";
 476                         print OUT "$k = $v\n";
 477                     } elsif ($cmd =~ /^=\s*$/) {
 478                         foreach $k (sort keys(%alias)) {
 479                             if (($v = $alias{$k}) =~ s~^s\~$k\~(.*)\~$~$1~) {
 480                                 print OUT "$k = $v\n";
 481                             } else {
 482                                 print OUT "$k\t$alias{$k}\n";
 483                             };
 484                         };
 485                     };
 486                     next CMD; };
 487             }
 488             $evalarg = $cmd; &eval;
 489             print OUT "\n";
 490         }
 491         if ($post) {
 492             $evalarg = $post; &eval;
 493         }
 494     }
 495     ($@, $!, $,, $/, $\) = @saved;
 496 }
 497
 498 sub save {
 499     @saved = ($@, $!, $,, $/, $\, $^W);
 500     $, = ""; $/ = "\n"; $\ = ""; $^W = 0;
 501 }
 502
 503 # The following takes its argument via $evalarg to preserve current @_
 504
 505 sub eval {
 506     eval "$usercontext $evalarg; &DB::save";
 507     print OUT $@;
 508 }
 509
 510 sub action {
 511     local($action) = @_;
 512     while ($action =~ s/\\$//) {
 513         print OUT "+ ";
 514         $action .= &gets;
 515     }
 516     $action;
 517 }
 518
 519 sub gets {
 520     local($.);
 521     <IN>;
 522 }
 523
 524 sub catch {
 525     $signal = 1;
 526 }
 527
 528 sub sub {
 529     push(@stack, $single);
 530     $single &= 1;
 531     $single |= 4 if $#stack == $deep;
 532     if (wantarray) {
 533         @i = &$sub;
 534         $single |= pop(@stack);
 535         @i;
 536     }
 537     else {
 538         $i = &$sub;
 539         $single |= pop(@stack);
 540         $i;
 541     }
 542 }
 543
 544 $trace = $signal = $single = 0; # uninitialized warning suppression
 545
 546 @hist = ('?');
 547 $SIG{'INT'} = "DB::catch";
 548 $deep = 100;            # warning if stack gets this deep
 549 $window = 10;
 550 $preview = 3;
 551
 552 @stack = (0);
 553 @ARGS = @ARGV;
 554 for (@args) {
 555     s/'/\\'/g;
 556     s/(.*)/'$1'/ unless /^-?[\d.]+$/;
 557 }
 558
 559 if (-f $rcfile) {
 560     do "./$rcfile";
 561 }
 562 elsif (-f "$ENV{'LOGDIR'}/$rcfile") {
 563     do "$ENV{'LOGDIR'}/$rcfile";
 564 }
 565 elsif (-f "$ENV{'HOME'}/$rcfile") {
 566     do "$ENV{'HOME'}/$rcfile";
 567 }
 568
 569 1;