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            $emacs ? "enabled" : "available",
  50            ".\n");
  51 print OUT "\nEnter h for help.\n\n";
  52
  53 @ARGS;
  54
  55 sub DB {
  56     &save;
  57     ($pkg, $filename, $line) = caller;
  58     $usercontext = '($@, $!, $,, $/, $\, $^W) = @saved;' .
  59         "package $pkg;";                # this won't let them modify, alas
  60     local(*dbline) = "::_<$filename";
  61     $max = $#dbline;
  62     if (($stop,$action) = split(/\0/,$dbline{$line})) {
  63         if ($stop eq '1') {
  64             $signal |= 1;
  65         }
  66         else {
  67             $evalarg = "\$DB::signal |= do {$stop;}"; &eval;
  68             $dbline{$line} =~ s/;9($|\0)/$1/;
  69         }
  70     }
  71     if ($single || $trace || $signal) {
  72         if ($emacs) {
  73             print OUT "\032\032$filename:$line:0\n";
  74         } else {
  75             $prefix = $sub =~ /'|::/ ? "" : "${pkg}::";
  76             $prefix .= "$sub($filename:";
  77             if (length($prefix) > 30) {
  78                 print OUT "$prefix$line):\n$line:\t",$dbline[$line];
  79                 $prefix = "";
  80                 $infix = ":\t";
  81             }
  82             else {
  83                 $infix = "):\t";
  84                 print OUT "$prefix$line$infix",$dbline[$line];
  85             }
  86             for ($i = $line + 1; $i <= $max && $dbline[$i] == 0; ++$i) {
  87                 last if $dbline[$i] =~ /^\s*(}|#|\n)/;
  88                 print OUT "$prefix$i$infix",$dbline[$i];
  89             }
  90         }
  91     }
  92     $evalarg = $action, &eval if $action;
  93     if ($single || $signal) {
  94         $evalarg = $pre, &eval if $pre;
  95         print OUT $#stack . " levels deep in subroutine calls!\n"
  96             if $single & 4;
  97         $start = $line;
  98       CMD:
  99         while ((print OUT "  DB<", $#hist+1, "> "), $cmd=&gets) {
 100             {
 101                 $single = 0;
 102                 $signal = 0;
 103                 $cmd eq '' && exit 0;
 104                 chop($cmd);
 105                 $cmd =~ s/\\$// && do {
 106                     print OUT "  cont: ";
 107                     $cmd .= &gets;
 108                     redo CMD;
 109                 };
 110                 $cmd =~ /^q$/ && exit 0;
 111                 $cmd =~ /^$/ && ($cmd = $laststep);
 112                 push(@hist,$cmd) if length($cmd) > 1;
 113                 ($i) = split(/\s+/,$cmd);
 114                 eval "\$cmd =~ $alias{$i}", print OUT $@ if $alias{$i};
 115                 $cmd =~ /^h$/ && do {
 116                     print OUT "
 117 T               Stack trace.
 118 s               Single step.
 119 n               Next, steps over subroutine calls.
 120 r               Return from current subroutine.
 121 c [line]        Continue; optionally inserts a one-time-only breakpoint
 122                 at the specified line.
 123 <CR>            Repeat last n or s.
 124 l min+incr      List incr+1 lines starting at min.
 125 l min-max       List lines.
 126 l line          List line;
 127 l               List next window.
 128 -               List previous window.
 129 w line          List window around line.
 130 l subname       List subroutine.
 131 f filename      Switch to filename.
 132 /pattern/       Search forwards for pattern; final / is optional.
 133 ?pattern?       Search backwards for pattern.
 134 L               List breakpoints and actions.
 135 S               List subroutine names.
 136 t               Toggle trace mode.
 137 b [line] [condition]
 138                 Set breakpoint; line defaults to the current execution line;
 139                 condition breaks if it evaluates to true, defaults to \'1\'.
 140 b subname [condition]
 141                 Set breakpoint at first line of subroutine.
 142 d [line]        Delete breakpoint.
 143 D               Delete all breakpoints.
 144 a [line] command
 145                 Set an action to be done before the line is executed.
 146                 Sequence is: check for breakpoint, print line if necessary,
 147                 do action, prompt user if breakpoint or step, evaluate line.
 148 A               Delete all actions.
 149 V [pkg [vars]]  List some (default all) variables in package (default current).
 150 X [vars]        Same as \"V currentpackage [vars]\".
 151 < command       Define command before prompt.
 152 > command       Define command after prompt.
 153 ! number        Redo command (default previous command).
 154 ! -number       Redo number\'th to last command.
 155 H -number       Display last number commands (default all).
 156 q or ^D         Quit.
 157 p expr          Same as \"print DB::OUT expr\" in current package.
 158 = [alias value] Define a command alias, or list current aliases.
 159 command         Execute as a perl statement in current package.
 160
 161 ";
 162                     next CMD; };
 163                 $cmd =~ /^t$/ && do {
 164                     $trace = !$trace;
 165                     print OUT "Trace = ".($trace?"on":"off")."\n";
 166                     next CMD; };
 167                 $cmd =~ /^S$/ && do {
 168                     foreach $subname (sort(keys %sub)) {
 169                         print OUT $subname,"\n";
 170                     }
 171                     next CMD; };
 172                 $cmd =~ s/^X\b/V $pkg/;
 173                 $cmd =~ /^V$/ && do {
 174                     $cmd = "V $pkg"; };
 175                 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
 176                     local ($savout) = select(OUT);
 177                     $packname = $1;
 178                     @vars = split(' ',$2);
 179                     do 'dumpvar.pl' unless defined &main::dumpvar;
 180                     if (defined &main::dumpvar) {
 181                         &main::dumpvar($packname,@vars);
 182                     }
 183                     else {
 184                         print DB::OUT "dumpvar.pl not available.\n";
 185                     }
 186                     select ($savout);
 187                     next CMD; };
 188                 $cmd =~ /^f\b\s*(.*)/ && do {
 189                     $file = $1;
 190                     if (!$file) {
 191                         print OUT "The old f command is now the r command.\n";
 192                         print OUT "The new f command switches filenames.\n";
 193                         next CMD;
 194                     }
 195                     if (!defined $main::{'_<' . $file}) {
 196                         if (($try) = grep(m#^_<.*$file#, keys %main::)) {
 197                             $file = substr($try,2);
 198                             print "\n$file:\n";
 199                         }
 200                     }
 201                     if (!defined $main::{'_<' . $file}) {
 202                         print OUT "There's no code here anything matching $file.\n";
 203                         next CMD;
 204                     }
 205                     elsif ($file ne $filename) {
 206                         *dbline = "::_<$file";
 207                         $max = $#dbline;
 208                         $filename = $file;
 209                         $start = 1;
 210                         $cmd = "l";
 211                     } };
 212                 $cmd =~ /^l\b\s*([':A-Za-z_][':\w]*)/ && do {
 213                     $subname = $1;
 214                     $subname = "main::" . $subname unless $subname =~ /'|::/;
 215                     $subname = "main" . $subname if substr($subname,0,1)eq "'";
 216                     $subname = "main" . $subname if substr($subname,0,2)eq "::";
 217                     ($file,$subrange) = split(/:/,$sub{$subname});
 218                     if ($file ne $filename) {
 219                         *dbline = "::_<$file";
 220                         $max = $#dbline;
 221                         $filename = $file;
 222                     }
 223                     if ($subrange) {
 224                         if (eval($subrange) < -$window) {
 225                             $subrange =~ s/-.*/+/;
 226                         }
 227                         $cmd = "l $subrange";
 228                     } else {
 229                         print OUT "Subroutine $1 not found.\n";
 230                         next CMD;
 231                     } };
 232                 $cmd =~ /^w\b\s*(\d*)$/ && do {
 233                     $incr = $window - 1;
 234                     $start = $1 if $1;
 235                     $start -= $preview;
 236                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 237                 $cmd =~ /^-$/ && do {
 238                     $incr = $window - 1;
 239                     $cmd = 'l ' . ($start-$window*2) . '+'; };
 240                 $cmd =~ /^l$/ && do {
 241                     $incr = $window - 1;
 242                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 243                 $cmd =~ /^l\b\s*(\d*)\+(\d*)$/ && do {
 244                     $start = $1 if $1;
 245                     $incr = $2;
 246                     $incr = $window - 1 unless $incr;
 247                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
 248                 $cmd =~ /^l\b\s*(([\d\$\.]+)([-,]([\d\$\.]+))?)?/ && do {
 249                     $end = (!$2) ? $max : ($4 ? $4 : $2);
 250                     $end = $max if $end > $max;
 251                     $i = $2;
 252                     $i = $line if $i eq '.';
 253                     $i = 1 if $i < 1;
 254                     if ($emacs) {
 255                         print OUT "\032\032$filename:$i:0\n";
 256                         $i = $end;
 257                     } else {
 258                         for (; $i <= $end; $i++) {
 259                             print OUT "$i:\t", $dbline[$i];
 260                             last if $signal;
 261                         }
 262                     }
 263                     $start = $i;        # remember in case they want more
 264                     $start = $max if $start > $max;
 265                     next CMD; };
 266                 $cmd =~ /^D$/ && do {
 267                     print OUT "Deleting all breakpoints...\n";
 268                     for ($i = 1; $i <= $max ; $i++) {
 269                         if (defined $dbline{$i}) {
 270                             $dbline{$i} =~ s/^[^\0]+//;
 271                             if ($dbline{$i} =~ s/^\0?$//) {
 272                                 delete $dbline{$i};
 273                             }
 274                         }
 275                     }
 276                     next CMD; };
 277                 $cmd =~ /^L$/ && do {
 278                     for ($i = 1; $i <= $max; $i++) {
 279                         if (defined $dbline{$i}) {
 280                             print OUT "$i:\t", $dbline[$i];
 281                             ($stop,$action) = split(/\0/, $dbline{$i});
 282                             print OUT "  break if (", $stop, ")\n"
 283                                 if $stop;
 284                             print OUT "  action:  ", $action, "\n"
 285                                 if $action;
 286                             last if $signal;
 287                         }
 288                     }
 289                     next CMD; };
 290                 $cmd =~ /^b\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ && do {
 291                     $subname = $1;
 292                     $cond = $2 || '1';
 293                     $subname = "${pkg}::" . $subname
 294                         unless $subname =~ /'|::/;
 295                     $subname = "main" . $subname if substr($subname,0,1) eq "'";
 296                     $subname = "main" . $subname if substr($subname,0,2) eq "::";
 297                     ($filename,$i) = split(/:/, $sub{$subname});
 298                     $i += 0;
 299                     if ($i) {
 300                         *dbline = "::_<$filename";
 301                         ++$i while $dbline[$i] == 0 && $i < $#dbline;
 302                         $dbline{$i} =~ s/^[^\0]*/$cond/;
 303                     } else {
 304                         print OUT "Subroutine $subname not found.\n";
 305                     }
 306                     next CMD; };
 307                 $cmd =~ /^b\b\s*(\d*)\s*(.*)/ && do {
 308                     $i = ($1?$1:$line);
 309                     $cond = $2 || '1';
 310                     if ($dbline[$i] == 0) {
 311                         print OUT "Line $i not breakable.\n";
 312                     } else {
 313                         $dbline{$i} =~ s/^[^\0]*/$cond/;
 314                     }
 315                     next CMD; };
 316                 $cmd =~ /^d\b\s*(\d+)?/ && do {
 317                     $i = ($1?$1:$line);
 318                     $dbline{$i} =~ s/^[^\0]*//;
 319                     delete $dbline{$i} if $dbline{$i} eq '';
 320                     next CMD; };
 321                 $cmd =~ /^A$/ && do {
 322                     for ($i = 1; $i <= $max ; $i++) {
 323                         if (defined $dbline{$i}) {
 324                             $dbline{$i} =~ s/\0[^\0]*//;
 325                             delete $dbline{$i} if $dbline{$i} eq '';
 326                         }
 327                     }
 328                     next CMD; };
 329                 $cmd =~ /^<\s*(.*)/ && do {
 330                     $pre = action($1);
 331                     next CMD; };
 332                 $cmd =~ /^>\s*(.*)/ && do {
 333                     $post = action($1);
 334                     next CMD; };
 335                 $cmd =~ /^a\b\s*(\d+)(\s+(.*))?/ && do {
 336                     $i = $1;
 337                     if ($dbline[$i] == 0) {
 338                         print OUT "Line $i may not have an action.\n";
 339                     } else {
 340                         $dbline{$i} =~ s/\0[^\0]*//;
 341                         $dbline{$i} .= "\0" . action($3);
 342                     }
 343                     next CMD; };
 344                 $cmd =~ /^n$/ && do {
 345                     $single = 2;
 346                     $laststep = $cmd;
 347                     last CMD; };
 348                 $cmd =~ /^s$/ && do {
 349                     $single = 1;
 350                     $laststep = $cmd;
 351                     last CMD; };
 352                 $cmd =~ /^c\b\s*(\d*)\s*$/ && do {
 353                     $i = $1;
 354                     if ($i) {
 355                         if ($dbline[$i] == 0) {
 356                             print OUT "Line $i not breakable.\n";
 357                             next CMD;
 358                         }
 359                         $dbline{$i} =~ s/(\0|$)/;9$1/;  # add one-time-only b.p.
 360                     }
 361                     for ($i=0; $i <= $#stack; ) {
 362                         $stack[$i++] &= ~1;
 363                     }
 364                     last CMD; };
 365                 $cmd =~ /^r$/ && do {
 366                     $stack[$#stack] |= 2;
 367                     last CMD; };
 368                 $cmd =~ /^T$/ && do {
 369                     local($p,$f,$l,$s,$h,$a,@a,@sub);
 370                     for ($i = 1; ($p,$f,$l,$s,$h,$w) = caller($i); $i++) {
 371                         @a = ();
 372                         for $arg (@args) {
 373                             $_ = "$arg";
 374                             s/'/\\'/g;
 375                             s/([^\0]*)/'$1'/
 376                                 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
 377                             s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
 378                             s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
 379                             push(@a, $_);
 380                         }
 381                         $w = $w ? '@ = ' : '$ = ';
 382                         $a = $h ? '(' . join(', ', @a) . ')' : '';
 383                         push(@sub, "$w$s$a from file $f line $l\n");
 384                         last if $signal;
 385                     }
 386                     for ($i=0; $i <= $#sub; $i++) {
 387                         last if $signal;
 388                         print OUT $sub[$i];
 389                     }
 390                     next CMD; };
 391                 $cmd =~ /^\/(.*)$/ && do {
 392                     $inpat = $1;
 393                     $inpat =~ s:([^\\])/$:$1:;
 394                     if ($inpat ne "") {
 395                         eval '$inpat =~ m'."\a$inpat\a";
 396                         if ($@ ne "") {
 397                             print OUT "$@";
 398                             next CMD;
 399                         }
 400                         $pat = $inpat;
 401                     }
 402                     $end = $start;
 403                     eval '
 404                     for (;;) {
 405                         ++$start;
 406                         $start = 1 if ($start > $max);
 407                         last if ($start == $end);
 408                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
 409                             if ($emacs) {
 410                                 print OUT "\032\032$filename:$start:0\n";
 411                             } else {
 412                                 print OUT "$start:\t", $dbline[$start], "\n";
 413                             }
 414                             last;
 415                         }
 416                     } ';
 417                     print OUT "/$pat/: not found\n" if ($start == $end);
 418                     next CMD; };
 419                 $cmd =~ /^\?(.*)$/ && do {
 420                     $inpat = $1;
 421                     $inpat =~ s:([^\\])\?$:$1:;
 422                     if ($inpat ne "") {
 423                         eval '$inpat =~ m'."\a$inpat\a";
 424                         if ($@ ne "") {
 425                             print OUT "$@";
 426                             next CMD;
 427                         }
 428                         $pat = $inpat;
 429                     }
 430                     $end = $start;
 431                     eval '
 432                     for (;;) {
 433                         --$start;
 434                         $start = $max if ($start <= 0);
 435                         last if ($start == $end);
 436                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
 437                             if ($emacs) {
 438                                 print OUT "\032\032$filename:$start:0\n";
 439                             } else {
 440                                 print OUT "$start:\t", $dbline[$start], "\n";
 441                             }
 442                             last;
 443                         }
 444                     } ';
 445                     print OUT "?$pat?: not found\n" if ($start == $end);
 446                     next CMD; };
 447                 $cmd =~ /^!+\s*(-)?(\d+)?$/ && do {
 448                     pop(@hist) if length($cmd) > 1;
 449                     $i = ($1?($#hist-($2?$2:1)):($2?$2:$#hist));
 450                     $cmd = $hist[$i] . "\n";
 451                     print OUT $cmd;
 452                     redo CMD; };
 453                 $cmd =~ /^!(.+)$/ && do {
 454                     $pat = "^$1";
 455                     pop(@hist) if length($cmd) > 1;
 456                     for ($i = $#hist; $i; --$i) {
 457                         last if $hist[$i] =~ $pat;
 458                     }
 459                     if (!$i) {
 460                         print OUT "No such command!\n\n";
 461                         next CMD;
 462                     }
 463                     $cmd = $hist[$i] . "\n";
 464                     print OUT $cmd;
 465                     redo CMD; };
 466                 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
 467                     $end = $2?($#hist-$2):0;
 468                     $hist = 0 if $hist < 0;
 469                     for ($i=$#hist; $i>$end; $i--) {
 470                         print OUT "$i: ",$hist[$i],"\n"
 471                             unless $hist[$i] =~ /^.?$/;
 472                     };
 473                     next CMD; };
 474                 $cmd =~ s/^p( .*)?$/print DB::OUT$1/;
 475                 $cmd =~ /^=/ && do {
 476                     if (local($k,$v) = ($cmd =~ /^=\s*(\S+)\s+(.*)/)) {
 477                         $alias{$k}="s~$k~$v~";
 478                         print OUT "$k = $v\n";
 479                     } elsif ($cmd =~ /^=\s*$/) {
 480                         foreach $k (sort keys(%alias)) {
 481                             if (($v = $alias{$k}) =~ s~^s\~$k\~(.*)\~$~$1~) {
 482                                 print OUT "$k = $v\n";
 483                             } else {
 484                                 print OUT "$k\t$alias{$k}\n";
 485                             };
 486                         };
 487                     };
 488                     next CMD; };
 489             }
 490             $evalarg = $cmd; &eval;
 491             print OUT "\n";
 492         }
 493         if ($post) {
 494             $evalarg = $post; &eval;
 495         }
 496     }
 497     ($@, $!, $,, $/, $\, $^W) = @saved;
 498     ();
 499 }
 500
 501 sub save {
 502     @saved = ($@, $!, $,, $/, $\, $^W);
 503     $, = ""; $/ = "\n"; $\ = ""; $^W = 0;
 504 }
 505
 506 # The following takes its argument via $evalarg to preserve current @_
 507
 508 sub eval {
 509     eval "$usercontext $evalarg; &DB::save";
 510     print OUT $@;
 511 }
 512
 513 sub action {
 514     local($action) = @_;
 515     while ($action =~ s/\\$//) {
 516         print OUT "+ ";
 517         $action .= &gets;
 518     }
 519     $action;
 520 }
 521
 522 sub gets {
 523     local($.);
 524     <IN>;
 525 }
 526
 527 sub catch {
 528     $signal = 1;
 529 }
 530
 531 sub sub {
 532     push(@stack, $single);
 533     $single &= 1;
 534     $single |= 4 if $#stack == $deep;
 535     if (wantarray) {
 536         @i = &$sub;
 537         $single |= pop(@stack);
 538         @i;
 539     }
 540     else {
 541         $i = &$sub;
 542         $single |= pop(@stack);
 543         $i;
 544     }
 545 }
 546
 547 $trace = $signal = $single = 0; # uninitialized warning suppression
 548
 549 @hist = ('?');
 550 $SIG{'INT'} = "DB::catch";
 551 $deep = 100;            # warning if stack gets this deep
 552 $window = 10;
 553 $preview = 3;
 554
 555 @stack = (0);
 556 @ARGS = @ARGV;
 557 for (@args) {
 558     s/'/\\'/g;
 559     s/(.*)/'$1'/ unless /^-?[\d.]+$/;
 560 }
 561
 562 if (-f $rcfile) {
 563     do "./$rcfile";
 564 }
 565 elsif (-f "$ENV{'LOGDIR'}/$rcfile") {
 566     do "$ENV{'LOGDIR'}/$rcfile";
 567 }
 568 elsif (-f "$ENV{'HOME'}/$rcfile") {
 569     do "$ENV{'HOME'}/$rcfile";
 570 }
 571
 572 1;