15a249832418d5ca30321291d073ff00259a245e
[perl.git] / 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 # Is Perl being run from Emacs?
19 $emacs = ((defined $main::ARGV[0]) and ($main::ARGV[0] eq '-emacs'));
20 shift(@main::ARGV) if $emacs;
21
22 #require Term::ReadLine;
23
24 local($^W) = 0;
25
26 if (-e "/dev/tty") {
27     $console = "/dev/tty";
28     $rcfile=".perldb";
29 }
30 elsif (-e "con") {
31     $console = "con";
32     $rcfile="perldb.ini";
33 }
34 else {
35     $console = "sys\$command";
36     $rcfile="perldb.ini";
37 }
38
39 # Around a bug:
40 if (defined $ENV{'OS2_SHELL'}) { # In OS/2
41   if ($DB::emacs) {
42     $console = undef;
43   } else {
44     $console = "/dev/con";
45   }
46 }
47
48 open(IN, "<$console") || open(IN,  "<&STDIN");  # so we don't dingle stdin
49 open(OUT,">$console") || open(OUT, ">&STDERR")
50     || open(OUT, ">&STDOUT");   # so we don't dongle stdout
51 select(OUT);
52 $| = 1;                         # for DB::OUT
53 select(STDOUT);
54 $| = 1;                         # for real STDOUT
55 $sub = '';
56
57 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
58 print OUT "\nLoading DB routines from $header\n";
59 print OUT ("Emacs support ",
60            $emacs ? "enabled" : "available",
61            ".\n");
62 print OUT "\nEnter h for help.\n\n";
63
64 @ARGS;
65
66 sub DB {
67     &save;
68     ($pkg, $filename, $line) = caller;
69     $usercontext = '($@, $!, $,, $/, $\, $^W) = @saved;' .
70         "package $pkg;";                # this won't let them modify, alas
71     local(*dbline) = "::_<$filename";
72     $max = $#dbline;
73     if (($stop,$action) = split(/\0/,$dbline{$line})) {
74         if ($stop eq '1') {
75             $signal |= 1;
76         }
77         else {
78             $evalarg = "\$DB::signal |= do {$stop;}"; &eval;
79             $dbline{$line} =~ s/;9($|\0)/$1/;
80         }
81     }
82     if ($single || $trace || $signal) {
83         if ($emacs) {
84             print OUT "\032\032$filename:$line:0\n";
85         } else {
86             $prefix = $sub =~ /'|::/ ? "" : "${pkg}::";
87             $prefix .= "$sub($filename:";
88             if (length($prefix) > 30) {
89                 print OUT "$prefix$line):\n$line:\t",$dbline[$line];
90                 $prefix = "";
91                 $infix = ":\t";
92             }
93             else {
94                 $infix = "):\t";
95                 print OUT "$prefix$line$infix",$dbline[$line];
96             }
97             for ($i = $line + 1; $i <= $max && $dbline[$i] == 0; ++$i) {
98                 last if $dbline[$i] =~ /^\s*(}|#|\n)/;
99                 print OUT "$prefix$i$infix",$dbline[$i];
100             }
101         }
102     }
103     $evalarg = $action, &eval if $action;
104     if ($single || $signal) {
105         $evalarg = $pre, &eval if $pre;
106         print OUT $#stack . " levels deep in subroutine calls!\n"
107             if $single & 4;
108         $start = $line;
109       CMD:
110         while ((print OUT "  DB<", $#hist+1, "> "), $cmd=&gets) {
111             {
112                 $single = 0;
113                 $signal = 0;
114                 $cmd eq '' && exit 0;
115                 chop($cmd);
116                 $cmd =~ s/\\$// && do {
117                     print OUT "  cont: ";
118                     $cmd .= &gets;
119                     redo CMD;
120                 };
121                 $cmd =~ /^q$/ && exit 0;
122                 $cmd =~ /^$/ && ($cmd = $laststep);
123                 push(@hist,$cmd) if length($cmd) > 1;
124                 ($i) = split(/\s+/,$cmd);
125                 eval "\$cmd =~ $alias{$i}", print OUT $@ if $alias{$i};
126                 $cmd =~ /^h$/ && do {
127                     print OUT "
128 T               Stack trace.
129 s               Single step.
130 n               Next, steps over subroutine calls.
131 r               Return from current subroutine.
132 c [line]        Continue; optionally inserts a one-time-only breakpoint 
133                 at the specified line.
134 <CR>            Repeat last n or s.
135 l min+incr      List incr+1 lines starting at min.
136 l min-max       List lines.
137 l line          List line;
138 l               List next window.
139 -               List previous window.
140 w line          List window around line.
141 l subname       List subroutine.
142 f filename      Switch to filename.
143 /pattern/       Search forwards for pattern; final / is optional.
144 ?pattern?       Search backwards for pattern.
145 L               List breakpoints and actions.
146 S               List subroutine names.
147 t               Toggle trace mode.
148 b [line] [condition]
149                 Set breakpoint; line defaults to the current execution line; 
150                 condition breaks if it evaluates to true, defaults to \'1\'.
151 b subname [condition]
152                 Set breakpoint at first line of subroutine.
153 d [line]        Delete breakpoint.
154 D               Delete all breakpoints.
155 a [line] command
156                 Set an action to be done before the line is executed.
157                 Sequence is: check for breakpoint, print line if necessary,
158                 do action, prompt user if breakpoint or step, evaluate line.
159 A               Delete all actions.
160 V [pkg [vars]]  List some (default all) variables in package (default current).
161 X [vars]        Same as \"V currentpackage [vars]\".
162 < command       Define command before prompt.
163 > command       Define command after prompt.
164 ! number        Redo command (default previous command).
165 ! -number       Redo number\'th to last command.
166 H -number       Display last number commands (default all).
167 q or ^D         Quit.
168 p expr          Same as \"print DB::OUT expr\" in current package.
169 = [alias value] Define a command alias, or list current aliases.
170 command         Execute as a perl statement in current package.
171
172 ";
173                     next CMD; };
174                 $cmd =~ /^t$/ && do {
175                     $trace = !$trace;
176                     print OUT "Trace = ".($trace?"on":"off")."\n";
177                     next CMD; };
178                 $cmd =~ /^S$/ && do {
179                     foreach $subname (sort(keys %sub)) {
180                         print OUT $subname,"\n";
181                     }
182                     next CMD; };
183                 $cmd =~ s/^X\b/V $pkg/;
184                 $cmd =~ /^V$/ && do {
185                     $cmd = "V $pkg"; };
186                 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
187                     local ($savout) = select(OUT);
188                     $packname = $1;
189                     @vars = split(' ',$2);
190                     do 'dumpvar.pl' unless defined &main::dumpvar;
191                     if (defined &main::dumpvar) {
192                         &main::dumpvar($packname,@vars);
193                     }
194                     else {
195                         print DB::OUT "dumpvar.pl not available.\n";
196                     }
197                     select ($savout);
198                     next CMD; };
199                 $cmd =~ /^f\b\s*(.*)/ && do {
200                     $file = $1;
201                     if (!$file) {
202                         print OUT "The old f command is now the r command.\n";
203                         print OUT "The new f command switches filenames.\n";
204                         next CMD;
205                     }
206                     if (!defined $main::{'_<' . $file}) {
207                         if (($try) = grep(m#^_<.*$file#, keys %main::)) {
208                             $file = substr($try,2);
209                             print "\n$file:\n";
210                         }
211                     }
212                     if (!defined $main::{'_<' . $file}) {
213                         print OUT "There's no code here anything matching $file.\n";
214                         next CMD;
215                     }
216                     elsif ($file ne $filename) {
217                         *dbline = "::_<$file";
218                         $max = $#dbline;
219                         $filename = $file;
220                         $start = 1;
221                         $cmd = "l";
222                     } };
223                 $cmd =~ /^l\b\s*([':A-Za-z_][':\w]*)/ && do {
224                     $subname = $1;
225                     $subname = "main::" . $subname unless $subname =~ /'|::/;
226                     $subname = "main" . $subname if substr($subname,0,1)eq "'";
227                     $subname = "main" . $subname if substr($subname,0,2)eq "::";
228                     # VMS filespecs may (usually do) contain ':', so don't use split
229                     ($file,$subrange) = $sub{$subname} =~ /(.*):(.*)/;
230                     if ($file ne $filename) {
231                         *dbline = "::_<$file";
232                         $max = $#dbline;
233                         $filename = $file;
234                     }
235                     if ($subrange) {
236                         if (eval($subrange) < -$window) {
237                             $subrange =~ s/-.*/+/;
238                         }
239                         $cmd = "l $subrange";
240                     } else {
241                         print OUT "Subroutine $1 not found.\n";
242                         next CMD;
243                     } };
244                 $cmd =~ /^w\b\s*(\d*)$/ && do {
245                     $incr = $window - 1;
246                     $start = $1 if $1;
247                     $start -= $preview;
248                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
249                 $cmd =~ /^-$/ && do {
250                     $incr = $window - 1;
251                     $cmd = 'l ' . ($start-$window*2) . '+'; };
252                 $cmd =~ /^l$/ && do {
253                     $incr = $window - 1;
254                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
255                 $cmd =~ /^l\b\s*(\d*)\+(\d*)$/ && do {
256                     $start = $1 if $1;
257                     $incr = $2;
258                     $incr = $window - 1 unless $incr;
259                     $cmd = 'l ' . $start . '-' . ($start + $incr); };
260                 $cmd =~ /^l\b\s*(([\d\$\.]+)([-,]([\d\$\.]+))?)?/ && do {
261                     $end = (!$2) ? $max : ($4 ? $4 : $2);
262                     $end = $max if $end > $max;
263                     $i = $2;
264                     $i = $line if $i eq '.';
265                     $i = 1 if $i < 1;
266                     if ($emacs) {
267                         print OUT "\032\032$filename:$i:0\n";
268                         $i = $end;
269                     } else {
270                         for (; $i <= $end; $i++) {
271                             print OUT "$i:\t", $dbline[$i];
272                             last if $signal;
273                         }
274                     }
275                     $start = $i;        # remember in case they want more
276                     $start = $max if $start > $max;
277                     next CMD; };
278                 $cmd =~ /^D$/ && do {
279                     print OUT "Deleting all breakpoints...\n";
280                     for ($i = 1; $i <= $max ; $i++) {
281                         if (defined $dbline{$i}) {
282                             $dbline{$i} =~ s/^[^\0]+//;
283                             if ($dbline{$i} =~ s/^\0?$//) {
284                                 delete $dbline{$i};
285                             }
286                         }
287                     }
288                     next CMD; };
289                 $cmd =~ /^L$/ && do {
290                     for ($i = 1; $i <= $max; $i++) {
291                         if (defined $dbline{$i}) {
292                             print OUT "$i:\t", $dbline[$i];
293                             ($stop,$action) = split(/\0/, $dbline{$i});
294                             print OUT "  break if (", $stop, ")\n" 
295                                 if $stop;
296                             print OUT "  action:  ", $action, "\n" 
297                                 if $action;
298                             last if $signal;
299                         }
300                     }
301                     next CMD; };
302                 $cmd =~ /^b\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ && do {
303                     $subname = $1;
304                     $cond = $2 || '1';
305                     $subname = "${pkg}::" . $subname
306                         unless $subname =~ /'|::/;
307                     $subname = "main" . $subname if substr($subname,0,1) eq "'";
308                     $subname = "main" . $subname if substr($subname,0,2) eq "::";
309                     # VMS filespecs may (usually do) contain ':', so don't use split
310                     ($filename,$i) = $sub{$subname} =~ /(.*):(.*)/;
311                     $i += 0;
312                     if ($i) {
313                         *dbline = "::_<$filename";
314                         ++$i while $dbline[$i] == 0 && $i < $#dbline;
315                         $dbline{$i} =~ s/^[^\0]*/$cond/;
316                     } else {
317                         print OUT "Subroutine $subname not found.\n";
318                     }
319                     next CMD; };
320                 $cmd =~ /^b\b\s*(\d*)\s*(.*)/ && do {
321                     $i = ($1?$1:$line);
322                     $cond = $2 || '1';
323                     if ($dbline[$i] == 0) {
324                         print OUT "Line $i not breakable.\n";
325                     } else {
326                         $dbline{$i} =~ s/^[^\0]*/$cond/;
327                     }
328                     next CMD; };
329                 $cmd =~ /^d\b\s*(\d+)?/ && do {
330                     $i = ($1?$1:$line);
331                     $dbline{$i} =~ s/^[^\0]*//;
332                     delete $dbline{$i} if $dbline{$i} eq '';
333                     next CMD; };
334                 $cmd =~ /^A$/ && do {
335                     for ($i = 1; $i <= $max ; $i++) {
336                         if (defined $dbline{$i}) {
337                             $dbline{$i} =~ s/\0[^\0]*//;
338                             delete $dbline{$i} if $dbline{$i} eq '';
339                         }
340                     }
341                     next CMD; };
342                 $cmd =~ /^<\s*(.*)/ && do {
343                     $pre = action($1);
344                     next CMD; };
345                 $cmd =~ /^>\s*(.*)/ && do {
346                     $post = action($1);
347                     next CMD; };
348                 $cmd =~ /^a\b\s*(\d+)(\s+(.*))?/ && do {
349                     $i = $1;
350                     if ($dbline[$i] == 0) {
351                         print OUT "Line $i may not have an action.\n";
352                     } else {
353                         $dbline{$i} =~ s/\0[^\0]*//;
354                         $dbline{$i} .= "\0" . action($3);
355                     }
356                     next CMD; };
357                 $cmd =~ /^n$/ && do {
358                     $single = 2;
359                     $laststep = $cmd;
360                     last CMD; };
361                 $cmd =~ /^s$/ && do {
362                     $single = 1;
363                     $laststep = $cmd;
364                     last CMD; };
365                 $cmd =~ /^c\b\s*(\d*)\s*$/ && do {
366                     $i = $1;
367                     if ($i) {
368                         if ($dbline[$i] == 0) {
369                             print OUT "Line $i not breakable.\n";
370                             next CMD;
371                         }
372                         $dbline{$i} =~ s/(\0|$)/;9$1/;  # add one-time-only b.p.
373                     }
374                     for ($i=0; $i <= $#stack; ) {
375                         $stack[$i++] &= ~1;
376                     }
377                     last CMD; };
378                 $cmd =~ /^r$/ && do {
379                     $stack[$#stack] |= 2;
380                     last CMD; };
381                 $cmd =~ /^T$/ && do {
382                     local($p,$f,$l,$s,$h,$a,@a,@sub);
383                     for ($i = 1; ($p,$f,$l,$s,$h,$w) = caller($i); $i++) {
384                         @a = ();
385                         for $arg (@args) {
386                             $_ = "$arg";
387                             s/'/\\'/g;
388                             s/([^\0]*)/'$1'/
389                                 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x;
390                             s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
391                             s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
392                             push(@a, $_);
393                         }
394                         $w = $w ? '@ = ' : '$ = ';
395                         $a = $h ? '(' . join(', ', @a) . ')' : '';
396                         push(@sub, "$w$s$a from file $f line $l\n");
397                         last if $signal;
398                     }
399                     for ($i=0; $i <= $#sub; $i++) {
400                         last if $signal;
401                         print OUT $sub[$i];
402                     }
403                     next CMD; };
404                 $cmd =~ /^\/(.*)$/ && do {
405                     $inpat = $1;
406                     $inpat =~ s:([^\\])/$:$1:;
407                     if ($inpat ne "") {
408                         eval '$inpat =~ m'."\a$inpat\a";        
409                         if ($@ ne "") {
410                             print OUT "$@";
411                             next CMD;
412                         }
413                         $pat = $inpat;
414                     }
415                     $end = $start;
416                     eval '
417                     for (;;) {
418                         ++$start;
419                         $start = 1 if ($start > $max);
420                         last if ($start == $end);
421                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
422                             if ($emacs) {
423                                 print OUT "\032\032$filename:$start:0\n";
424                             } else {
425                                 print OUT "$start:\t", $dbline[$start], "\n";
426                             }
427                             last;
428                         }
429                     } ';
430                     print OUT "/$pat/: not found\n" if ($start == $end);
431                     next CMD; };
432                 $cmd =~ /^\?(.*)$/ && do {
433                     $inpat = $1;
434                     $inpat =~ s:([^\\])\?$:$1:;
435                     if ($inpat ne "") {
436                         eval '$inpat =~ m'."\a$inpat\a";        
437                         if ($@ ne "") {
438                             print OUT "$@";
439                             next CMD;
440                         }
441                         $pat = $inpat;
442                     }
443                     $end = $start;
444                     eval '
445                     for (;;) {
446                         --$start;
447                         $start = $max if ($start <= 0);
448                         last if ($start == $end);
449                         if ($dbline[$start] =~ m'."\a$pat\a".'i) {
450                             if ($emacs) {
451                                 print OUT "\032\032$filename:$start:0\n";
452                             } else {
453                                 print OUT "$start:\t", $dbline[$start], "\n";
454                             }
455                             last;
456                         }
457                     } ';
458                     print OUT "?$pat?: not found\n" if ($start == $end);
459                     next CMD; };
460                 $cmd =~ /^!+\s*(-)?(\d+)?$/ && do {
461                     pop(@hist) if length($cmd) > 1;
462                     $i = ($1?($#hist-($2?$2:1)):($2?$2:$#hist));
463                     $cmd = $hist[$i] . "\n";
464                     print OUT $cmd;
465                     redo CMD; };
466                 $cmd =~ /^!(.+)$/ && do {
467                     $pat = "^$1";
468                     pop(@hist) if length($cmd) > 1;
469                     for ($i = $#hist; $i; --$i) {
470                         last if $hist[$i] =~ $pat;
471                     }
472                     if (!$i) {
473                         print OUT "No such command!\n\n";
474                         next CMD;
475                     }
476                     $cmd = $hist[$i] . "\n";
477                     print OUT $cmd;
478                     redo CMD; };
479                 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
480                     $end = $2?($#hist-$2):0;
481                     $hist = 0 if $hist < 0;
482                     for ($i=$#hist; $i>$end; $i--) {
483                         print OUT "$i: ",$hist[$i],"\n"
484                             unless $hist[$i] =~ /^.?$/;
485                     };
486                     next CMD; };
487                 $cmd =~ s/^p( .*)?$/print DB::OUT$1/;
488                 $cmd =~ /^=/ && do {
489                     if (local($k,$v) = ($cmd =~ /^=\s*(\S+)\s+(.*)/)) {
490                         $alias{$k}="s~$k~$v~";
491                         print OUT "$k = $v\n";
492                     } elsif ($cmd =~ /^=\s*$/) {
493                         foreach $k (sort keys(%alias)) {
494                             if (($v = $alias{$k}) =~ s~^s\~$k\~(.*)\~$~$1~) {
495                                 print OUT "$k = $v\n";
496                             } else {
497                                 print OUT "$k\t$alias{$k}\n";
498                             };
499                         };
500                     };
501                     next CMD; };
502             }
503             $evalarg = $cmd; &eval;
504             print OUT "\n";
505         }
506         if ($post) {
507             $evalarg = $post; &eval;
508         }
509     }
510     ($@, $!, $,, $/, $\, $^W) = @saved;
511     ();
512 }
513
514 sub save {
515     @saved = ($@, $!, $,, $/, $\, $^W);
516     $, = ""; $/ = "\n"; $\ = ""; $^W = 0;
517 }
518
519 # The following takes its argument via $evalarg to preserve current @_
520
521 sub eval {
522     eval "$usercontext $evalarg; &DB::save";
523     print OUT $@;
524 }
525
526 sub action {
527     local($action) = @_;
528     while ($action =~ s/\\$//) {
529         print OUT "+ ";
530         $action .= &gets;
531     }
532     $action;
533 }
534
535 sub gets {
536     local($.);
537     <IN>;
538 }
539
540 sub catch {
541     $signal = 1;
542 }
543
544 sub sub {
545     push(@stack, $single);
546     $single &= 1;
547     $single |= 4 if $#stack == $deep;
548     if (wantarray) {
549         @i = &$sub;
550         $single |= pop(@stack);
551         @i;
552     }
553     else {
554         $i = &$sub;
555         $single |= pop(@stack);
556         $i;
557     }
558 }
559
560 $trace = $signal = $single = 0; # uninitialized warning suppression
561
562 @hist = ('?');
563 $SIG{'INT'} = "DB::catch";
564 $deep = 100;            # warning if stack gets this deep
565 $window = 10;
566 $preview = 3;
567
568 @stack = (0);
569 @ARGS = @ARGV;
570 for (@args) {
571     s/'/\\'/g;
572     s/(.*)/'$1'/ unless /^-?[\d.]+$/;
573 }
574
575 if (-f $rcfile) {
576     do "./$rcfile";
577 }
578 elsif (-f "$ENV{'LOGDIR'}/$rcfile") {
579     do "$ENV{'LOGDIR'}/$rcfile";
580 }
581 elsif (-f "$ENV{'HOME'}/$rcfile") {
582     do "$ENV{'HOME'}/$rcfile";
583 }
584
585 1;