This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
bump perl5db.pl's $VERSION
[perl5.git] / lib / perl5db.pl
CommitLineData
e22ea7cc 1
b570d64b 2=head1 NAME
69893cff 3
be9a9b1d 4perl5db.pl - the perl debugger
69893cff
RGS
5
6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
69893cff
RGS
26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
69893cff
RGS
38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
69893cff
RGS
44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
69893cff
RGS
52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
69893cff
RGS
63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
69893cff
RGS
66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
69893cff
RGS
70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
69893cff
RGS
79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
69893cff
RGS
83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
69893cff
RGS
89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
69893cff
RGS
93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
69893cff
RGS
97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
69893cff
RGS
101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
69893cff
RGS
109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
69893cff
RGS
118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
69893cff
RGS
126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
69893cff
RGS
131it?
132
133=over 4
134
be9a9b1d 135=item *
69893cff 136
be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
69893cff
RGS
141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
69893cff
RGS
144works.
145
be9a9b1d
AT
146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
69893cff
RGS
149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
be9a9b1d
AT
153=item *
154
b570d64b
SF
155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
69893cff
RGS
158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
69893cff
RGS
166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
69893cff
RGS
172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
7e17a74c
JJ
176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
b570d64b
SF
182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
69893cff
RGS
187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
da052516 189The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
be9a9b1d
AT
190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
ee59ac17 192like C<(eval 34)>.
69893cff
RGS
193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
69893cff
RGS
200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
69893cff
RGS
204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
69893cff
RGS
214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
69893cff
RGS
218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
69893cff
RGS
221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
69893cff
RGS
227ReadLine applications.
228
b570d64b 229=item * NonStop
69893cff
RGS
230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
69893cff
RGS
234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
69893cff
RGS
239
240host:port to connect to on remote host for remote debugging.
241
5561b870
AK
242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
69893cff
RGS
252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
69893cff
RGS
262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
69893cff
RGS
269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
69893cff
RGS
285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
69893cff
RGS
308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
69893cff
RGS
314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
69893cff
RGS
318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
7e3426ea 321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
69893cff
RGS
322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
69893cff
RGS
326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
b570d64b
SF
331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
69893cff
RGS
333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
69893cff
RGS
354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
69893cff
RGS
368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
be9a9b1d
AT
375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
69893cff
RGS
377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
69893cff
RGS
383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
69893cff
RGS
406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
69893cff
RGS
446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
69893cff
RGS
454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 476=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
69893cff
RGS
477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
69893cff
RGS
486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
b570d64b
SF
490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
69893cff
RGS
494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
69893cff
RGS
504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
a687059c
LW
511package DB;
512
6b24a4b7
SF
513use strict;
514
c59f1e04
SF
515use Cwd ();
516
517my $_initial_cwd;
518
2dbd01ad 519BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 520
e56c1e8d
SF
521BEGIN {
522 require feature;
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
c59f1e04 525 $_initial_cwd = Cwd::getcwd();
e56c1e8d
SF
526}
527
54d04a52 528# Debugger for Perl 5.00x; perl5db.pl patch level:
6b24a4b7
SF
529use vars qw($VERSION $header);
530
dcfbcce2
TC
531# bump to X.XX in blead, only use X.XX_XX in maint
532$VERSION = '1.50';
69893cff 533
e22ea7cc 534$header = "perl5db.pl version $VERSION";
d338d6fe 535
69893cff
RGS
536=head1 DEBUGGER ROUTINES
537
538=head2 C<DB::eval()>
539
540This function replaces straight C<eval()> inside the debugger; it simplifies
541the process of evaluating code in the user's context.
542
b570d64b 543The code to be evaluated is passed via the package global variable
69893cff
RGS
544C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
545
be9a9b1d
AT
546Before we do the C<eval()>, we preserve the current settings of C<$trace>,
547C<$single>, C<$^D> and C<$usercontext>. The latter contains the
548preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
549user's current package, grabbed when C<DB::DB> got control. This causes the
550proper context to be used when the eval is actually done. Afterward, we
551restore C<$trace>, C<$single>, and C<$^D>.
69893cff
RGS
552
553Next we need to handle C<$@> without getting confused. We save C<$@> in a
b570d64b
SF
554local lexical, localize C<$saved[0]> (which is where C<save()> will put
555C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 556C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
b570d64b
SF
557considered sane by the debugger. If there was an C<eval()> error, we print
558it on the debugger's output. If C<$onetimedump> is defined, we call
559C<dumpit> if it's set to 'dump', or C<methods> if it's set to
560'methods'. Setting it to something else causes the debugger to do the eval
561but not print the result - handy if you want to do something else with it
69893cff
RGS
562(the "watch expressions" code does this to get the value of the watch
563expression but not show it unless it matters).
564
b570d64b
SF
565In any case, we then return the list of output from C<eval> to the caller,
566and unwinding restores the former version of C<$@> in C<@saved> as well
69893cff
RGS
567(the localization of C<$saved[0]> goes away at the end of this scope).
568
569=head3 Parameters and variables influencing execution of DB::eval()
570
571C<DB::eval> isn't parameterized in the standard way; this is to keep the
572debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 573The variables listed below influence C<DB::eval()>'s execution directly.
69893cff
RGS
574
575=over 4
576
577=item C<$evalarg> - the thing to actually be eval'ed
578
be9a9b1d 579=item C<$trace> - Current state of execution tracing
69893cff 580
be9a9b1d 581=item C<$single> - Current state of single-stepping
69893cff 582
b570d64b 583=item C<$onetimeDump> - what is to be displayed after the evaluation
69893cff
RGS
584
585=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
586
587=back
588
589The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 590are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
591
592=over 4
593
594=item C<@res> - used to capture output from actual C<eval>.
595
596=item C<$otrace> - saved value of C<$trace>.
597
b570d64b 598=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
599
600=item C<$od> - saved value of C<$^D>.
601
602=item C<$saved[0]> - saved value of C<$@>.
603
b570d64b 604=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
605
606=back
607
608=head3 The problem of lexicals
609
610The context of C<DB::eval()> presents us with some problems. Obviously,
611we want to be 'sandboxed' away from the debugger's internals when we do
612the eval, but we need some way to control how punctuation variables and
b570d64b 613debugger globals are used.
69893cff
RGS
614
615We can't use local, because the code inside C<DB::eval> can see localized
616variables; and we can't use C<my> either for the same reason. The code
617in this routine compromises and uses C<my>.
618
619After this routine is over, we don't have user code executing in the debugger's
620context, so we can use C<my> freely.
621
622=cut
623
624############################################## Begin lexical danger zone
625
626# 'my' variables used here could leak into (that is, be visible in)
627# the context that the code being evaluated is executing in. This means that
628# the code could modify the debugger's variables.
629#
630# Fiddling with the debugger's context could be Bad. We insulate things as
631# much as we can.
632
6b24a4b7
SF
633use vars qw(
634 @args
635 %break_on_load
6b24a4b7
SF
636 $CommandSet
637 $CreateTTY
638 $DBGR
639 @dbline
640 $dbline
641 %dbline
642 $dieLevel
6b24a4b7 643 $filename
6b24a4b7
SF
644 $histfile
645 $histsize
6b24a4b7
SF
646 $IN
647 $inhibit_exit
648 @ini_INC
649 $ini_warn
6b24a4b7
SF
650 $maxtrace
651 $od
6b24a4b7
SF
652 @options
653 $osingle
654 $otrace
6b24a4b7
SF
655 $pager
656 $post
657 %postponed
658 $prc
659 $pre
660 $pretype
661 $psh
662 @RememberOnROptions
663 $remoteport
664 @res
665 $rl
666 @saved
6b24a4b7 667 $signalLevel
6b24a4b7 668 $sub
6b24a4b7 669 $term
6b24a4b7
SF
670 $usercontext
671 $warnLevel
6b24a4b7
SF
672);
673
0b83f3d9 674our (
2ef1dcdb 675 @cmdfhs,
0b83f3d9
SF
676 $evalarg,
677 $frame,
0664c09a 678 $hist,
0b83f3d9
SF
679 $ImmediateStop,
680 $line,
681 $onetimeDump,
b8d11fe0 682 $onetimedumpDepth,
1ce985d2 683 %option,
0b83f3d9 684 $OUT,
1ce985d2 685 $packname,
0b83f3d9
SF
686 $signal,
687 $single,
d1450c23 688 $start,
9d0b71b3
SF
689 %sub,
690 $subname,
0b83f3d9 691 $trace,
d1450c23 692 $window,
18b5b545 693);
931ac036 694
6b24a4b7
SF
695# Used to save @ARGV and extract any debugger-related flags.
696use vars qw(@ARGS);
697
698# Used to prevent multiple entries to diesignal()
699# (if for instance diesignal() itself dies)
700use vars qw($panic);
701
702# Used to prevent the debugger from running nonstop
703# after a restart
ebd0282e 704our ($second_time);
6b24a4b7
SF
705
706sub _calc_usercontext {
707 my ($package) = @_;
708
709 # Cancel strict completely for the evaluated code, so the code
710 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 711 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
712 . "package $package;"; # this won't let them modify, alas
713}
714
c1051fcf 715sub eval {
69893cff 716
c1051fcf 717 # 'my' would make it visible from user code
e22ea7cc 718 # but so does local! --tchrist
69893cff 719 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
720 local @res;
721 {
e22ea7cc
RF
722
723 # Try to keep the user code from messing with us. Save these so that
724 # even if the eval'ed code changes them, we can put them back again.
725 # Needed because the user could refer directly to the debugger's
69893cff
RGS
726 # package globals (and any 'my' variables in this containing scope)
727 # inside the eval(), and we want to try to stay safe.
e22ea7cc 728 local $otrace = $trace;
69893cff
RGS
729 local $osingle = $single;
730 local $od = $^D;
731
732 # Untaint the incoming eval() argument.
733 { ($evalarg) = $evalarg =~ /(.*)/s; }
734
e22ea7cc 735 # $usercontext built in DB::DB near the comment
69893cff
RGS
736 # "set up the context for DB::eval ..."
737 # Evaluate and save any results.
e22ea7cc 738 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
739
740 # Restore those old values.
741 $trace = $otrace;
742 $single = $osingle;
743 $^D = $od;
c1051fcf 744 }
69893cff
RGS
745
746 # Save the current value of $@, and preserve it in the debugger's copy
747 # of the saved precious globals.
c1051fcf 748 my $at = $@;
69893cff
RGS
749
750 # Since we're only saving $@, we only have to localize the array element
751 # that it will be stored in.
e22ea7cc 752 local $saved[0]; # Preserve the old value of $@
e3d167f6 753 eval { &DB::save };
69893cff
RGS
754
755 # Now see whether we need to report an error back to the user.
c1051fcf 756 if ($at) {
69893cff
RGS
757 local $\ = '';
758 print $OUT $at;
759 }
760
761 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
762 # are package globals.
763 elsif ($onetimeDump) {
e22ea7cc
RF
764 if ( $onetimeDump eq 'dump' ) {
765 local $option{dumpDepth} = $onetimedumpDepth
766 if defined $onetimedumpDepth;
767 dumpit( $OUT, \@res );
768 }
769 elsif ( $onetimeDump eq 'methods' ) {
770 methods( $res[0] );
771 }
69893cff 772 } ## end elsif ($onetimeDump)
c1051fcf 773 @res;
69893cff
RGS
774} ## end sub eval
775
776############################################## End lexical danger zone
c1051fcf 777
e22ea7cc
RF
778# After this point it is safe to introduce lexicals.
779# The code being debugged will be executing in its own context, and
69893cff 780# can't see the inside of the debugger.
d338d6fe 781#
e22ea7cc 782# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
783# possible. If you make something a lexical, it's not going to be addressable
784# from outside the debugger even if you know its name.
785
d338d6fe
PP
786# This file is automatically included if you do perl -d.
787# It's probably not useful to include this yourself.
788#
e22ea7cc 789# Before venturing further into these twisty passages, it is
2f7e9187
MS
790# wise to read the perldebguts man page or risk the ire of dragons.
791#
69893cff
RGS
792# (It should be noted that perldebguts will tell you a lot about
793# the underlying mechanics of how the debugger interfaces into the
794# Perl interpreter, but not a lot about the debugger itself. The new
795# comments in this code try to address this problem.)
796
d338d6fe 797# Note that no subroutine call is possible until &DB::sub is defined
36477c24 798# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 799# true if $deep is not defined.
055fd3a9
GS
800
801# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
802
803# modified Perl debugger, to be run from Emacs in perldb-mode
804# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
805# Johan Vromans -- upgrade to 4.0 pl 10
806# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 807########################################################################
d338d6fe 808
69893cff
RGS
809=head1 DEBUGGER INITIALIZATION
810
811The debugger starts up in phases.
812
813=head2 BASIC SETUP
814
815First, it initializes the environment it wants to run in: turning off
816warnings during its own compilation, defining variables which it will need
817to avoid warnings later, setting itself up to not exit when the program
818terminates, and defaulting to printing return values for the C<r> command.
819
820=cut
821
eda6e075 822# Needed for the statement after exec():
69893cff
RGS
823#
824# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 825# compilation. Probably it would be better practice to fix the warnings,
69893cff 826# but this is how it's done at the moment.
eda6e075 827
e22ea7cc
RF
828BEGIN {
829 $ini_warn = $^W;
830 $^W = 0;
831} # Switch compilation warnings off until another BEGIN.
d12a4851 832
69893cff
RGS
833local ($^W) = 0; # Switch run-time warnings off during init.
834
2cbb2ee1
RGS
835=head2 THREADS SUPPORT
836
837If we are running under a threaded Perl, we require threads and threads::shared
838if the environment variable C<PERL5DB_THREADED> is set, to enable proper
839threaded debugger control. C<-dt> can also be used to set this.
840
841Each new thread will be announced and the debugger prompt will always inform
842you of each new thread created. It will also indicate the thread id in which
843we are currently running within the prompt like this:
844
2dbd01ad 845 [tid] DB<$i>
2cbb2ee1
RGS
846
847Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
848command prompt. The prompt will show: C<[0]> when running under threads, but
849not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
850
851While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 852will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
853in a currently executing thread, you will stay there until it completes. With
854the current implementation it is not currently possible to hop from one thread
855to another.
856
857The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
858
859Note that threading support was built into the debugger as of Perl version
860C<5.8.6> and debugger version C<1.2.8>.
861
862=cut
863
864BEGIN {
2dbd01ad
SF
865 # ensure we can share our non-threaded variables or no-op
866 if ($ENV{PERL5DB_THREADED}) {
867 require threads;
868 require threads::shared;
869 import threads::shared qw(share);
870 $DBGR;
871 share(\$DBGR);
872 lock($DBGR);
873 print "Threads support enabled\n";
874 } else {
41ef2c66 875 *lock = sub(*) {};
cde405a6 876 *share = sub(\[$@%]) {};
2dbd01ad 877 }
2cbb2ee1
RGS
878}
879
2218c045
SF
880# These variables control the execution of 'dumpvar.pl'.
881{
882 package dumpvar;
883 use vars qw(
884 $hashDepth
885 $arrayDepth
886 $dumpDBFiles
887 $dumpPackages
888 $quoteHighBit
889 $printUndef
890 $globPrint
891 $usageOnly
892 );
893}
69893cff 894
2218c045
SF
895# used to control die() reporting in diesignal()
896{
897 package Carp;
898 use vars qw($CarpLevel);
899}
d338d6fe 900
422c59bf 901# without threads, $filename is not defined until DB::DB is called
cde405a6 902share($main::{'_<'.$filename}) if defined $filename;
2cbb2ee1 903
54d04a52 904# Command-line + PERLLIB:
69893cff 905# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
906@ini_INC = @INC;
907
69893cff
RGS
908# This was an attempt to clear out the previous values of various
909# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
910# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
911
69893cff
RGS
912# We set these variables to safe values. We don't want to blindly turn
913# off warnings, because other packages may still want them.
e22ea7cc
RF
914$trace = $signal = $single = 0; # Uninitialized warning suppression
915 # (local $^W cannot help - other packages!).
69893cff
RGS
916
917# Default to not exiting when program finishes; print the return
918# value when the 'r' command is used to return from a subroutine.
55497cff 919$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 920
6b24a4b7
SF
921use vars qw($trace_to_depth);
922
5e2b42dd
SF
923# Default to 1E9 so it won't be limited to a certain recursion depth.
924$trace_to_depth = 1E9;
bdba49ad 925
69893cff
RGS
926=head1 OPTION PROCESSING
927
b570d64b
SF
928The debugger's options are actually spread out over the debugger itself and
929C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
930subs to be called with a value. To try to make this a little easier to
931manage, the debugger uses a few data structures to define what options
932are legal and how they are to be processed.
933
934First, the C<@options> array defines the I<names> of all the options that
935are to be accepted.
936
937=cut
938
939@options = qw(
5561b870 940 CommandSet HistFile HistSize
e22ea7cc
RF
941 hashDepth arrayDepth dumpDepth
942 DumpDBFiles DumpPackages DumpReused
943 compactDump veryCompact quote
944 HighBit undefPrint globPrint
945 PrintRet UsageOnly frame
946 AutoTrace TTY noTTY
947 ReadLine NonStop LineInfo
948 maxTraceLen recallCommand ShellBang
949 pager tkRunning ornaments
950 signalLevel warnLevel dieLevel
951 inhibit_exit ImmediateStop bareStringify
952 CreateTTY RemotePort windowSize
584420f0 953 DollarCaretP
e22ea7cc 954);
d12a4851 955
584420f0 956@RememberOnROptions = qw(DollarCaretP);
d12a4851 957
69893cff
RGS
958=pod
959
960Second, C<optionVars> lists the variables that each option uses to save its
961state.
962
963=cut
964
6b24a4b7
SF
965use vars qw(%optionVars);
966
69893cff 967%optionVars = (
e22ea7cc
RF
968 hashDepth => \$dumpvar::hashDepth,
969 arrayDepth => \$dumpvar::arrayDepth,
970 CommandSet => \$CommandSet,
971 DumpDBFiles => \$dumpvar::dumpDBFiles,
972 DumpPackages => \$dumpvar::dumpPackages,
973 DumpReused => \$dumpvar::dumpReused,
974 HighBit => \$dumpvar::quoteHighBit,
975 undefPrint => \$dumpvar::printUndef,
976 globPrint => \$dumpvar::globPrint,
977 UsageOnly => \$dumpvar::usageOnly,
978 CreateTTY => \$CreateTTY,
979 bareStringify => \$dumpvar::bareStringify,
980 frame => \$frame,
981 AutoTrace => \$trace,
982 inhibit_exit => \$inhibit_exit,
983 maxTraceLen => \$maxtrace,
984 ImmediateStop => \$ImmediateStop,
985 RemotePort => \$remoteport,
986 windowSize => \$window,
5561b870
AK
987 HistFile => \$histfile,
988 HistSize => \$histsize,
69893cff
RGS
989);
990
991=pod
992
993Third, C<%optionAction> defines the subroutine to be called to process each
994option.
995
b570d64b 996=cut
69893cff 997
6b24a4b7
SF
998use vars qw(%optionAction);
999
69893cff
RGS
1000%optionAction = (
1001 compactDump => \&dumpvar::compactDump,
1002 veryCompact => \&dumpvar::veryCompact,
1003 quote => \&dumpvar::quote,
1004 TTY => \&TTY,
1005 noTTY => \&noTTY,
1006 ReadLine => \&ReadLine,
1007 NonStop => \&NonStop,
1008 LineInfo => \&LineInfo,
1009 recallCommand => \&recallCommand,
1010 ShellBang => \&shellBang,
1011 pager => \&pager,
1012 signalLevel => \&signalLevel,
1013 warnLevel => \&warnLevel,
1014 dieLevel => \&dieLevel,
1015 tkRunning => \&tkRunning,
1016 ornaments => \&ornaments,
1017 RemotePort => \&RemotePort,
1018 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1019);
1020
69893cff
RGS
1021=pod
1022
1023Last, the C<%optionRequire> notes modules that must be C<require>d if an
1024option is used.
1025
1026=cut
d338d6fe 1027
69893cff
RGS
1028# Note that this list is not complete: several options not listed here
1029# actually require that dumpvar.pl be loaded for them to work, but are
1030# not in the table. A subsequent patch will correct this problem; for
1031# the moment, we're just recommenting, and we are NOT going to change
1032# function.
6b24a4b7
SF
1033use vars qw(%optionRequire);
1034
eda6e075 1035%optionRequire = (
69893cff
RGS
1036 compactDump => 'dumpvar.pl',
1037 veryCompact => 'dumpvar.pl',
1038 quote => 'dumpvar.pl',
e22ea7cc 1039);
69893cff
RGS
1040
1041=pod
1042
1043There are a number of initialization-related variables which can be set
1044by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1045variable. These are:
1046
1047=over 4
1048
1049=item C<$rl> - readline control XXX needs more explanation
1050
1051=item C<$warnLevel> - whether or not debugger takes over warning handling
1052
1053=item C<$dieLevel> - whether or not debugger takes over die handling
1054
1055=item C<$signalLevel> - whether or not debugger takes over signal handling
1056
1057=item C<$pre> - preprompt actions (array reference)
1058
1059=item C<$post> - postprompt actions (array reference)
1060
1061=item C<$pretype>
1062
1063=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1064
1065=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1066
1067=back
1068
1069=cut
d338d6fe
PP
1070
1071# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1072$rl = 1 unless defined $rl;
1073$warnLevel = 1 unless defined $warnLevel;
1074$dieLevel = 1 unless defined $dieLevel;
1075$signalLevel = 1 unless defined $signalLevel;
1076$pre = [] unless defined $pre;
1077$post = [] unless defined $post;
1078$pretype = [] unless defined $pretype;
1079$CreateTTY = 3 unless defined $CreateTTY;
1080$CommandSet = '580' unless defined $CommandSet;
1081
2cbb2ee1
RGS
1082share($rl);
1083share($warnLevel);
1084share($dieLevel);
1085share($signalLevel);
1086share($pre);
1087share($post);
1088share($pretype);
1089share($rl);
1090share($CreateTTY);
1091share($CommandSet);
1092
69893cff
RGS
1093=pod
1094
1095The default C<die>, C<warn>, and C<signal> handlers are set up.
1096
1097=cut
055fd3a9 1098
d338d6fe
PP
1099warnLevel($warnLevel);
1100dieLevel($dieLevel);
1101signalLevel($signalLevel);
055fd3a9 1102
69893cff
RGS
1103=pod
1104
1105The pager to be used is needed next. We try to get it from the
5561b870 1106environment first. If it's not defined there, we try to find it in
69893cff
RGS
1107the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1108then call the C<pager()> function to save the pager name.
1109
1110=cut
1111
1112# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1113pager(
e22ea7cc 1114
69893cff 1115 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1116 defined $ENV{PAGER}
1117 ? $ENV{PAGER}
69893cff
RGS
1118
1119 # If not, see if Config.pm defines it.
e22ea7cc
RF
1120 : eval { require Config }
1121 && defined $Config::Config{pager}
1122 ? $Config::Config{pager}
69893cff
RGS
1123
1124 # If not, fall back to 'more'.
e22ea7cc
RF
1125 : 'more'
1126 )
1127 unless defined $pager;
69893cff
RGS
1128
1129=pod
1130
1131We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1132recall character (C<!> unless otherwise defined) and the shell escape
1133character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1134neither works in the debugger at the moment.
1135
1136=cut
1137
055fd3a9 1138setman();
69893cff
RGS
1139
1140# Set up defaults for command recall and shell escape (note:
1141# these currently don't work in linemode debugging).
2218c045
SF
1142recallCommand("!") unless defined $prc;
1143shellBang("!") unless defined $psh;
69893cff
RGS
1144
1145=pod
1146
1147We then set up the gigantic string containing the debugger help.
1148We also set the limit on the number of arguments we'll display during a
1149trace.
1150
1151=cut
1152
04e43a21 1153sethelp();
69893cff
RGS
1154
1155# If we didn't get a default for the length of eval/stack trace args,
1156# set it here.
1d06cb2d 1157$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1158
1159=head2 SETTING UP THE DEBUGGER GREETING
1160
be9a9b1d 1161The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1162running, and whether the current debugger is the primary or a child.
1163
1164If we are the primary, we just hang onto our pid so we'll have it when
1165or if we start a child debugger. If we are a child, we'll set things up
1166so we'll have a unique greeting and so the parent will give us our own
1167TTY later.
1168
1169We save the current contents of the C<PERLDB_PIDS> environment variable
1170because we mess around with it. We'll also need to hang onto it because
1171we'll need it if we restart.
1172
1173Child debuggers make a label out of the current PID structure recorded in
1174PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1175yet so the parent will give them one later via C<resetterm()>.
1176
1177=cut
1178
e22ea7cc 1179# Save the current contents of the environment; we're about to
69893cff 1180# much with it. We'll need this if we have to restart.
6b24a4b7 1181use vars qw($ini_pids);
f1583d8f 1182$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1183
6b24a4b7
SF
1184use vars qw ($pids $term_pid);
1185
e22ea7cc
RF
1186if ( defined $ENV{PERLDB_PIDS} ) {
1187
69893cff 1188 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1189 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1190 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1191
1192 my $env_pids = $ENV{PERLDB_PIDS};
1193 $pids = "[$env_pids]";
1194
1195 # Unless we are on OpenVMS, all programs under the DCL shell run under
1196 # the same PID.
1197
1198 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1199 $term_pid = $$;
1200 }
1201 else {
1202 $ENV{PERLDB_PIDS} .= "->$$";
1203 $term_pid = -1;
1204 }
1205
69893cff
RGS
1206} ## end if (defined $ENV{PERLDB_PIDS...
1207else {
e22ea7cc
RF
1208
1209 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1210 # child debugger, and mark us as the parent, so we'll know to set up
1211 # more TTY's is we have to.
1212 $ENV{PERLDB_PIDS} = "$$";
619a0444 1213 $pids = "[pid=$$]";
e22ea7cc 1214 $term_pid = $$;
f1583d8f 1215}
69893cff 1216
6b24a4b7 1217use vars qw($pidprompt);
f1583d8f 1218$pidprompt = '';
69893cff
RGS
1219
1220# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1221our ($slave_editor);
69893cff
RGS
1222*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1223
1224=head2 READING THE RC FILE
1225
b570d64b 1226The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1227running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1228
b570d64b 1229=cut
69893cff
RGS
1230
1231# As noted, this test really doesn't check accurately that the debugger
1232# is running at a terminal or not.
d338d6fe 1233
6b24a4b7 1234use vars qw($rcfile);
fb4d8a6c
SF
1235{
1236 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1237 # this is the wrong metric!
1238 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1239}
1240
69893cff
RGS
1241=pod
1242
1243The debugger does a safety test of the file to be read. It must be owned
1244either by the current user or root, and must only be writable by the owner.
1245
1246=cut
1247
1248# This wraps a safety test around "do" to read and evaluate the init file.
1249#
055fd3a9
GS
1250# This isn't really safe, because there's a race
1251# between checking and opening. The solution is to
1252# open and fstat the handle, but then you have to read and
1253# eval the contents. But then the silly thing gets
69893cff
RGS
1254# your lexical scope, which is unfortunate at best.
1255sub safe_do {
055fd3a9
GS
1256 my $file = shift;
1257
1258 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1259 local $SIG{__WARN__};
1260 local $SIG{__DIE__};
055fd3a9 1261
e22ea7cc 1262 unless ( is_safe_file($file) ) {
69893cff 1263 CORE::warn <<EO_GRIPE;
055fd3a9 1264perldb: Must not source insecure rcfile $file.
b570d64b 1265 You or the superuser must be the owner, and it must not
69893cff 1266 be writable by anyone but its owner.
055fd3a9 1267EO_GRIPE
69893cff
RGS
1268 return;
1269 } ## end unless (is_safe_file($file...
055fd3a9
GS
1270
1271 do $file;
1272 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1273} ## end sub safe_do
055fd3a9 1274
69893cff
RGS
1275# This is the safety test itself.
1276#
055fd3a9
GS
1277# Verifies that owner is either real user or superuser and that no
1278# one but owner may write to it. This function is of limited use
1279# when called on a path instead of upon a handle, because there are
1280# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1281# eventually accessed is the same as the one tested.
055fd3a9
GS
1282# Assumes that the file's existence is not in doubt.
1283sub is_safe_file {
1284 my $path = shift;
69893cff 1285 stat($path) || return; # mysteriously vaporized
e22ea7cc 1286 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1287
1288 return 0 if $uid != 0 && $uid != $<;
1289 return 0 if $mode & 022;
1290 return 1;
69893cff 1291} ## end sub is_safe_file
055fd3a9 1292
69893cff 1293# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1294# exists, we safely do it.
1295if ( -f $rcfile ) {
055fd3a9 1296 safe_do("./$rcfile");
69893cff 1297}
e22ea7cc 1298
69893cff 1299# If there isn't one here, try the user's home directory.
e22ea7cc 1300elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1301 safe_do("$ENV{HOME}/$rcfile");
1302}
e22ea7cc 1303
69893cff 1304# Else try the login directory.
e22ea7cc 1305elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1306 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1307}
1308
69893cff 1309# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1310if ( defined $ENV{PERLDB_OPTS} ) {
1311 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1312}
1313
69893cff
RGS
1314=pod
1315
1316The last thing we do during initialization is determine which subroutine is
1317to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1318the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1319(darwin).
69893cff
RGS
1320
1321=cut
1322
1323# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1324# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1325# OS/2, or on Mac OS X. This may need some expansion.
1326
1327if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1328{
b570d64b 1329 if ( defined $remoteport ) {
11653f7f
JJ
1330 # Expect an inetd-like server
1331 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1332 }
1333 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1334 # of terminal this is,
1335 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1336 and defined $ENV{DISPLAY} # and what display it's on,
1337 )
1338 {
1339 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1340 }
babb663a
RH
1341 elsif ( $ENV{TMUX} ) {
1342 *get_fork_TTY = \&tmux_get_fork_TTY;
1343 }
6fae1ad7
RF
1344 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1345 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1346 }
1347 elsif ( $^O eq 'darwin' # If this is Mac OS X
1348 and defined $ENV{TERM_PROGRAM} # and we're running inside
1349 and $ENV{TERM_PROGRAM}
1350 eq 'Apple_Terminal' # Terminal.app
1351 )
1352 {
1353 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1354 }
69893cff 1355} ## end if (not defined &get_fork_TTY...
e22ea7cc 1356
dbb46cec
DQ
1357# untaint $^O, which may have been tainted by the last statement.
1358# see bug [perl #24674]
e22ea7cc
RF
1359$^O =~ m/^(.*)\z/;
1360$^O = $1;
f1583d8f 1361
d12a4851 1362# Here begin the unreadable code. It needs fixing.
055fd3a9 1363
69893cff
RGS
1364=head2 RESTART PROCESSING
1365
1366This section handles the restart command. When the C<R> command is invoked, it
1367tries to capture all of the state it can into environment variables, and
1368then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1369if C<PERLDB_RESTART> is there; if so, we reload all the information that
1370the R command stuffed into the environment variables.
1371
b570d64b 1372 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1373 PERLDB_HIST - command history, if it's available
1374 PERLDB_ON_LOAD - breakpoints set by the rc file
555bd962
BG
1375 PERLDB_POSTPONE - subs that have been loaded/not executed,
1376 and have actions
69893cff
RGS
1377 PERLDB_VISITED - files that had breakpoints
1378 PERLDB_FILE_... - breakpoints for a file
1379 PERLDB_OPT - active options
1380 PERLDB_INC - the original @INC
1381 PERLDB_PRETYPE - preprompt debugger actions
1382 PERLDB_PRE - preprompt Perl code
1383 PERLDB_POST - post-prompt Perl code
1384 PERLDB_TYPEAHEAD - typeahead captured by readline()
1385
1386We chug through all these variables and plug the values saved in them
1387back into the appropriate spots in the debugger.
1388
1389=cut
1390
0664c09a 1391use vars qw(%postponed_file @typeahead);
14f38b27 1392
0664c09a 1393our (@hist, @truehist);
6b24a4b7 1394
fb0fb5f4
SF
1395sub _restore_shared_globals_after_restart
1396{
1397 @hist = get_list('PERLDB_HIST');
1398 %break_on_load = get_list("PERLDB_ON_LOAD");
1399 %postponed = get_list("PERLDB_POSTPONE");
1400
1401 share(@hist);
1402 share(@truehist);
1403 share(%break_on_load);
1404 share(%postponed);
1405}
1406
e18a02a6 1407sub _restore_breakpoints_and_actions {
e22ea7cc 1408
e22ea7cc 1409 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1410
bdba49ad
SF
1411 for my $file_idx ( 0 .. $#had_breakpoints ) {
1412 my $filename = $had_breakpoints[$file_idx];
1413 my %pf = get_list("PERLDB_FILE_$file_idx");
1414 $postponed_file{ $filename } = \%pf if %pf;
1415 my @lines = sort {$a <=> $b} keys(%pf);
1416 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1417 for my $line_idx (0 .. $#lines) {
1418 _set_breakpoint_enabled_status(
1419 $filename,
1420 $lines[$line_idx],
1421 ($enabled_statuses[$line_idx] ? 1 : ''),
1422 );
1423 }
e22ea7cc 1424 }
69893cff 1425
e18a02a6
SF
1426 return;
1427}
1428
ca50076b
SF
1429sub _restore_options_after_restart
1430{
1431 my %options_map = get_list("PERLDB_OPT");
1432
1433 while ( my ( $opt, $val ) = each %options_map ) {
1434 $val =~ s/[\\\']/\\$1/g;
1435 parse_options("$opt'$val'");
1436 }
1437
1438 return;
1439}
1440
18580168
SF
1441sub _restore_globals_after_restart
1442{
1443 # restore original @INC
1444 @INC = get_list("PERLDB_INC");
1445 @ini_INC = @INC;
1446
1447 # return pre/postprompt actions and typeahead buffer
1448 $pretype = [ get_list("PERLDB_PRETYPE") ];
1449 $pre = [ get_list("PERLDB_PRE") ];
1450 $post = [ get_list("PERLDB_POST") ];
1451 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1452
1453 return;
1454}
1455
fb0fb5f4 1456
e18a02a6
SF
1457if ( exists $ENV{PERLDB_RESTART} ) {
1458
1459 # We're restarting, so we don't need the flag that says to restart anymore.
1460 delete $ENV{PERLDB_RESTART};
1461
1462 # $restart = 1;
fb0fb5f4 1463 _restore_shared_globals_after_restart();
e18a02a6
SF
1464
1465 _restore_breakpoints_and_actions();
1466
69893cff 1467 # restore options
ca50076b 1468 _restore_options_after_restart();
69893cff 1469
18580168 1470 _restore_globals_after_restart();
69893cff
RGS
1471} ## end if (exists $ENV{PERLDB_RESTART...
1472
1473=head2 SETTING UP THE TERMINAL
1474
1475Now, we'll decide how the debugger is going to interact with the user.
1476If there's no TTY, we set the debugger to run non-stop; there's not going
1477to be anyone there to enter commands.
1478
1479=cut
54d04a52 1480
ebd0282e 1481use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1482use vars qw($lineinfo $doccmd);
1483
ebd0282e
SF
1484our ($runnonstop);
1485
e0047406
KF
1486# Local autoflush to avoid rt#116769,
1487# as calling IO::File methods causes an unresolvable loop
1488# that results in debugger failure.
1489sub _autoflush {
1490 my $o = select($_[0]);
1491 $|++;
1492 select($o);
1493}
1494
d338d6fe 1495if ($notty) {
69893cff 1496 $runnonstop = 1;
2dbd01ad 1497 share($runnonstop);
69893cff 1498}
d12a4851 1499
69893cff
RGS
1500=pod
1501
1502If there is a TTY, we have to determine who it belongs to before we can
1503proceed. If this is a slave editor or graphical debugger (denoted by
1504the first command-line switch being '-emacs'), we shift this off and
1505set C<$rl> to 0 (XXX ostensibly to do straight reads).
1506
1507=cut
1508
1509else {
e22ea7cc 1510
69893cff
RGS
1511 # Is Perl being run from a slave editor or graphical debugger?
1512 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1513 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1514 $rl = 0;
1515 shift(@main::ARGV);
1516 }
e22ea7cc
RF
1517
1518 #require Term::ReadLine;
d12a4851 1519
69893cff
RGS
1520=pod
1521
1522We then determine what the console should be on various systems:
1523
1524=over 4
1525
1526=item * Cygwin - We use C<stdin> instead of a separate device.
1527
1528=cut
1529
e22ea7cc
RF
1530 if ( $^O eq 'cygwin' ) {
1531
69893cff
RGS
1532 # /dev/tty is binary. use stdin for textmode
1533 undef $console;
1534 }
1535
f703fc96 1536=item * Unix - use F</dev/tty>.
69893cff
RGS
1537
1538=cut
1539
e22ea7cc 1540 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1541 $console = "/dev/tty";
1542 }
1543
1544=item * Windows or MSDOS - use C<con>.
1545
1546=cut
1547
e22ea7cc 1548 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1549 $console = "con";
1550 }
1551
cf412c92
AB
1552=item * AmigaOS - use C<CONSOLE:>.
1553
1554=cut
1555
1556 elsif ( $^O eq 'amigaos' ) {
1557 $console = "CONSOLE:";
1558 }
1559
69893cff
RGS
1560=item * VMS - use C<sys$command>.
1561
1562=cut
1563
c9cc5940
JH
1564 elsif ($^O eq 'VMS') {
1565 $console = 'sys$command';
1566 }
1567
1568# Keep this last.
e22ea7cc 1569
c9cc5940
JH
1570 else {
1571 _db_warn("Can't figure out your console, using stdin");
1572 undef $console;
d12a4851 1573 }
69893cff
RGS
1574
1575=pod
1576
1577=back
1578
1579Several other systems don't use a specific console. We C<undef $console>
1580for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
739a0b84 1581with a slave editor).
69893cff
RGS
1582
1583=cut
d12a4851 1584
e22ea7cc
RF
1585 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1586
69893cff 1587 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1588 $console = undef;
1589 }
1590
1591 if ( $^O eq 'NetWare' ) {
d12a4851 1592
69893cff
RGS
1593 # /dev/tty is binary. use stdin for textmode
1594 $console = undef;
1595 }
d12a4851 1596
69893cff
RGS
1597 # In OS/2, we need to use STDIN to get textmode too, even though
1598 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1599 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1600 { # In OS/2
1601 $console = undef;
1602 }
1603
69893cff
RGS
1604=pod
1605
1606If there is a TTY hanging around from a parent, we use that as the console.
1607
1608=cut
1609
e22ea7cc 1610 $console = $tty if defined $tty;
d12a4851 1611
b570d64b 1612=head2 SOCKET HANDLING
69893cff
RGS
1613
1614The debugger is capable of opening a socket and carrying out a debugging
1615session over the socket.
1616
1617If C<RemotePort> was defined in the options, the debugger assumes that it
1618should try to start a debugging session on that port. It builds the socket
1619and then tries to connect the input and output filehandles to it.
1620
1621=cut
1622
1623 # Handle socket stuff.
e22ea7cc
RF
1624
1625 if ( defined $remoteport ) {
1626
69893cff
RGS
1627 # If RemotePort was defined in the options, connect input and output
1628 # to the socket.
11653f7f 1629 $IN = $OUT = connect_remoteport();
69893cff
RGS
1630 } ## end if (defined $remoteport)
1631
1632=pod
1633
1634If no C<RemotePort> was defined, and we want to create a TTY on startup,
1635this is probably a situation where multiple debuggers are running (for example,
1636a backticked command that starts up another debugger). We create a new IN and
1637OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1638and if we can.
1639
1640=cut
1641
1642 # Non-socket.
1643 else {
e22ea7cc 1644
69893cff
RGS
1645 # Two debuggers running (probably a system or a backtick that invokes
1646 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1647 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1648 # know how, and we can.
e22ea7cc
RF
1649 create_IN_OUT(4) if $CreateTTY & 4;
1650 if ($console) {
1651
69893cff 1652 # If we have a console, check to see if there are separate ins and
cd1191f1 1653 # outs to open. (They are assumed identical if not.)
69893cff 1654
e22ea7cc
RF
1655 my ( $i, $o ) = split /,/, $console;
1656 $o = $i unless defined $o;
69893cff 1657
69893cff 1658 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1659 open( IN, "+<$i" )
1660 || open( IN, "<$i" )
1661 || open( IN, "<&STDIN" );
1662
69893cff
RGS
1663 # read/write/create/clobber out, or write/create/clobber out,
1664 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1665 open( OUT, "+>$o" )
1666 || open( OUT, ">$o" )
1667 || open( OUT, ">&STDERR" )
1668 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1669
1670 } ## end if ($console)
1671 elsif ( not defined $console ) {
1672
1673 # No console. Open STDIN.
1674 open( IN, "<&STDIN" );
1675
1676 # merge with STDERR, or with STDOUT.
1677 open( OUT, ">&STDERR" )
1678 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1679 $console = 'STDIN/OUT';
69893cff
RGS
1680 } ## end elsif (not defined $console)
1681
1682 # Keep copies of the filehandles so that when the pager runs, it
1683 # can close standard input without clobbering ours.
2b0b9dd1
SF
1684 if ($console or (not defined($console))) {
1685 $IN = \*IN;
1686 $OUT = \*OUT;
1687 }
e22ea7cc
RF
1688 } ## end elsif (from if(defined $remoteport))
1689
1690 # Unbuffer DB::OUT. We need to see responses right away.
e0047406 1691 _autoflush($OUT);
e22ea7cc
RF
1692
1693 # Line info goes to debugger output unless pointed elsewhere.
1694 # Pointing elsewhere makes it possible for slave editors to
1695 # keep track of file and position. We have both a filehandle
1696 # and a I/O description to keep track of.
1697 $LINEINFO = $OUT unless defined $LINEINFO;
1698 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1699 # share($LINEINFO); # <- unable to share globs
1700 share($lineinfo); #
e22ea7cc 1701
69893cff
RGS
1702=pod
1703
1704To finish initialization, we show the debugger greeting,
1705and then call the C<afterinit()> subroutine if there is one.
1706
1707=cut
d12a4851 1708
e22ea7cc
RF
1709 # Show the debugger greeting.
1710 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1711 unless ($runnonstop) {
1712 local $\ = '';
1713 local $, = '';
1714 if ( $term_pid eq '-1' ) {
1715 print $OUT "\nDaughter DB session started...\n";
1716 }
1717 else {
1718 print $OUT "\nLoading DB routines from $header\n";
1719 print $OUT (
1720 "Editor support ",
1721 $slave_editor ? "enabled" : "available", ".\n"
1722 );
1723 print $OUT
1f874cb6 1724"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1725 } ## end else [ if ($term_pid eq '-1')
1726 } ## end unless ($runnonstop)
1727} ## end else [ if ($notty)
1728
1729# XXX This looks like a bug to me.
1730# Why copy to @ARGS and then futz with @args?
d338d6fe 1731@ARGS = @ARGV;
6b24a4b7 1732# for (@args) {
69893cff
RGS
1733 # Make sure backslashes before single quotes are stripped out, and
1734 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1735 # s/\'/\\\'/g; # removed while not justified understandably
1736 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1737# }
d338d6fe 1738
e22ea7cc 1739# If there was an afterinit() sub defined, call it. It will get
69893cff 1740# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1741if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1742 afterinit();
d338d6fe 1743}
e22ea7cc 1744
69893cff 1745# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1746use vars qw($I_m_init);
1747
43aed9ee
IZ
1748$I_m_init = 1;
1749
d338d6fe
PP
1750############################################################ Subroutines
1751
69893cff
RGS
1752=head1 SUBROUTINES
1753
1754=head2 DB
1755
1756This gigantic subroutine is the heart of the debugger. Called before every
1757statement, its job is to determine if a breakpoint has been reached, and
1758stop if so; read commands from the user, parse them, and execute
b468dcb6 1759them, and then send execution off to the next statement.
69893cff
RGS
1760
1761Note that the order in which the commands are processed is very important;
1762some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1763to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1764but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1765see what's happening in any given command.
1766
1767=cut
1768
136ae23d
SF
1769# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1770
6b24a4b7
SF
1771use vars qw(
1772 $action
6b24a4b7 1773 $cmd
6b24a4b7
SF
1774 $file
1775 $filename_ini
1776 $finished
1777 %had_breakpoints
6b24a4b7
SF
1778 $level
1779 $max
6b24a4b7 1780 $package
6b24a4b7
SF
1781 $try
1782);
1783
1ce985d2 1784our (
bdb3f37d 1785 %alias,
1ce985d2 1786 $doret,
0664c09a 1787 $end,
4d0e1f38 1788 $fall_off_end,
d1450c23 1789 $incr,
73c5e526 1790 $laststep,
14f38b27 1791 $rc,
ddf4cf26 1792 $sh,
1ce985d2
SF
1793 $stack_depth,
1794 @stack,
1795 @to_watch,
1796 @old_watch,
1797);
8ad70697 1798
6791e41b
SF
1799sub _DB__determine_if_we_should_break
1800{
1801 # if we have something here, see if we should break.
1802 # $stop is lexical and local to this block - $action on the other hand
1803 # is global.
1804 my $stop;
1805
1806 if ( $dbline{$line}
1807 && _is_breakpoint_enabled($filename, $line)
1808 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1809 {
1810
1811 # Stop if the stop criterion says to just stop.
1812 if ( $stop eq '1' ) {
1813 $signal |= 1;
1814 }
1815
1816 # It's a conditional stop; eval it in the user's context and
1817 # see if we should stop. If so, remove the one-time sigil.
1818 elsif ($stop) {
1819 $evalarg = "\$DB::signal |= 1 if do {$stop}";
e0cd3692
SF
1820 # The &-call is here to ascertain the mutability of @_.
1821 &DB::eval;
6791e41b
SF
1822 # If the breakpoint is temporary, then delete its enabled status.
1823 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1824 _cancel_breakpoint_temp_enabled_status($filename, $line);
1825 }
1826 }
1827 } ## end if ($dbline{$line} && ...
1828}
1829
8481f647
SF
1830sub _DB__is_finished {
1831 if ($finished and $level <= 1) {
1832 end_report();
1833 return 1;
1834 }
1835 else {
1836 return;
1837 }
1838}
1839
32bbadc6
SF
1840sub _DB__read_next_cmd
1841{
1842 my ($tid) = @_;
1843
1844 # We have a terminal, or can get one ...
1845 if (!$term) {
1846 setterm();
1847 }
1848
7e3426ea 1849 # ... and it belongs to this PID or we get one for this PID ...
32bbadc6
SF
1850 if ($term_pid != $$) {
1851 resetterm(1);
1852 }
1853
1854 # ... and we got a line of command input ...
1855 $cmd = DB::readline(
1856 "$pidprompt $tid DB"
1857 . ( '<' x $level )
1858 . ( $#hist + 1 )
1859 . ( '>' x $level ) . " "
1860 );
1861
1862 return defined($cmd);
1863}
1864
7013f40c 1865sub _DB__trim_command_and_return_first_component {
af84fb69
SF
1866 my ($obj) = @_;
1867
7013f40c
SF
1868 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1869 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1870
3249b113 1871 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
af84fb69 1872
3249b113
SF
1873 $obj->cmd_verb($verb);
1874 $obj->cmd_args($args);
af84fb69
SF
1875
1876 return;
7013f40c
SF
1877}
1878
2a802473 1879sub _DB__handle_f_command {
a30f63cd 1880 my ($obj) = @_;
2a802473 1881
a30f63cd 1882 if ($file = $obj->cmd_args) {
2a802473
SF
1883 # help for no arguments (old-style was return from sub).
1884 if ( !$file ) {
1885 print $OUT
1886 "The old f command is now the r command.\n"; # hint
1887 print $OUT "The new f command switches filenames.\n";
1888 next CMD;
1889 } ## end if (!$file)
1890
1891 # if not in magic file list, try a close match.
1892 if ( !defined $main::{ '_<' . $file } ) {
1893 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1894 {
1895 $try = substr( $try, 2 );
1896 print $OUT "Choosing $try matching '$file':\n";
1897 $file = $try;
1898 }
1899 } ## end if (($try) = grep(m#^_<.*$file#...
1900 } ## end if (!defined $main::{ ...
1901
1902 # If not successfully switched now, we failed.
1903 if ( !defined $main::{ '_<' . $file } ) {
1904 print $OUT "No file matching '$file' is loaded.\n";
1905 next CMD;
1906 }
1907
1908 # We switched, so switch the debugger internals around.
1909 elsif ( $file ne $filename ) {
1910 *dbline = $main::{ '_<' . $file };
1911 $max = $#dbline;
1912 $filename = $file;
1913 $start = 1;
1914 $cmd = "l";
1915 } ## end elsif ($file ne $filename)
1916
1917 # We didn't switch; say we didn't.
1918 else {
1919 print $OUT "Already in $file.\n";
1920 next CMD;
1921 }
1922 }
1923
1924 return;
1925}
1926
6115a173
SF
1927sub _DB__handle_dot_command {
1928 my ($obj) = @_;
1929
1930 # . command.
601c6a23 1931 if ($obj->_is_full('.')) {
6115a173
SF
1932 $incr = -1; # stay at current line
1933
1934 # Reset everything to the old location.
1935 $start = $line;
1936 $filename = $filename_ini;
1937 *dbline = $main::{ '_<' . $filename };
1938 $max = $#dbline;
1939
1940 # Now where are we?
1941 print_lineinfo($obj->position());
1942 next CMD;
1943 }
1944
1945 return;
1946}
1947
5c2b78e7
SF
1948sub _DB__handle_y_command {
1949 my ($obj) = @_;
1950
1951 if (my ($match_level, $match_vars)
9875a6d2 1952 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
5c2b78e7
SF
1953
1954 # See if we've got the necessary support.
db79bf92
TC
1955 if (!eval {
1956 local @INC = @INC;
1957 pop @INC if $INC[-1] eq '.';
1958 require PadWalker; PadWalker->VERSION(0.08) }) {
84e7f475 1959 my $Err = $@;
b5679dc0 1960 _db_warn(
84e7f475
SF
1961 $Err =~ /locate/
1962 ? "PadWalker module not found - please install\n"
1963 : $Err
1964 );
1965 next CMD;
1966 }
5c2b78e7
SF
1967
1968 # Load up dumpvar if we don't have it. If we can, that is.
1969 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1970 defined &main::dumpvar
1971 or print $OUT "dumpvar.pl not available.\n"
1972 and next CMD;
1973
1974 # Got all the modules we need. Find them and print them.
1975 my @vars = split( ' ', $match_vars || '' );
1976
1977 # Find the pad.
496f5ba5 1978 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
5c2b78e7
SF
1979
1980 # Oops. Can't find it.
84e7f475
SF
1981 if (my $Err = $@) {
1982 $Err =~ s/ at .*//;
b5679dc0 1983 _db_warn($Err);
84e7f475
SF
1984 next CMD;
1985 }
5c2b78e7
SF
1986
1987 # Show the desired vars with dumplex().
1988 my $savout = select($OUT);
1989
1990 # Have dumplex dump the lexicals.
84e7f475
SF
1991 foreach my $key (sort keys %$h) {
1992 dumpvar::dumplex( $key, $h->{$key},
1993 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1994 @vars );
1995 }
5c2b78e7
SF
1996 select($savout);
1997 next CMD;
1998 }
1999}
2000
35cd713a
SF
2001sub _DB__handle_c_command {
2002 my ($obj) = @_;
2003
a523ec7c 2004 my $i = $obj->cmd_args;
35cd713a 2005
a523ec7c 2006 if ($i =~ m#\A[\w:]*\z#) {
35cd713a
SF
2007
2008 # Hey, show's over. The debugged program finished
2009 # executing already.
2010 next CMD if _DB__is_finished();
2011
2012 # Capture the place to put a one-time break.
a523ec7c 2013 $subname = $i;
35cd713a
SF
2014
2015 # Probably not needed, since we finish an interactive
2016 # sub-session anyway...
2017 # local $filename = $filename;
2018 # local *dbline = *dbline; # XXX Would this work?!
2019 #
2020 # The above question wonders if localizing the alias
2021 # to the magic array works or not. Since it's commented
2022 # out, we'll just leave that to speculation for now.
2023
2024 # If the "subname" isn't all digits, we'll assume it
2025 # is a subroutine name, and try to find it.
2026 if ( $subname =~ /\D/ ) { # subroutine name
2027 # Qualify it to the current package unless it's
2028 # already qualified.
2029 $subname = $package . "::" . $subname
2030 unless $subname =~ /::/;
2031
2032 # find_sub will return "file:line_number" corresponding
2033 # to where the subroutine is defined; we call find_sub,
2034 # break up the return value, and assign it in one
2035 # operation.
a523ec7c 2036 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
35cd713a
SF
2037
2038 # Force the line number to be numeric.
a523ec7c 2039 $i = $i + 0;
35cd713a
SF
2040
2041 # If we got a line number, we found the sub.
a523ec7c 2042 if ($i) {
35cd713a
SF
2043
2044 # Switch all the debugger's internals around so
2045 # we're actually working with that file.
2046 $filename = $file;
2047 *dbline = $main::{ '_<' . $filename };
2048
2049 # Mark that there's a breakpoint in this file.
2050 $had_breakpoints{$filename} |= 1;
2051
2052 # Scan forward to the first executable line
2053 # after the 'sub whatever' line.
2054 $max = $#dbline;
a523ec7c 2055 my $_line_num = $i;
9c6fceaf
SF
2056 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2057 {
2058 $_line_num++;
2059 }
a523ec7c 2060 $i = $_line_num;
35cd713a
SF
2061 } ## end if ($i)
2062
2063 # We didn't find a sub by that name.
2064 else {
2065 print $OUT "Subroutine $subname not found.\n";
2066 next CMD;
2067 }
2068 } ## end if ($subname =~ /\D/)
2069
2070 # At this point, either the subname was all digits (an
2071 # absolute line-break request) or we've scanned through
2072 # the code following the definition of the sub, looking
2073 # for an executable, which we may or may not have found.
2074 #
2075 # If $i (which we set $subname from) is non-zero, we
2076 # got a request to break at some line somewhere. On
2077 # one hand, if there wasn't any real subroutine name
2078 # involved, this will be a request to break in the current
2079 # file at the specified line, so we have to check to make
2080 # sure that the line specified really is breakable.
2081 #
2082 # On the other hand, if there was a subname supplied, the
2083 # preceding block has moved us to the proper file and
2084 # location within that file, and then scanned forward
2085 # looking for the next executable line. We have to make
2086 # sure that one was found.
2087 #
2088 # On the gripping hand, we can't do anything unless the
2089 # current value of $i points to a valid breakable line.
2090 # Check that.
a523ec7c 2091 if ($i) {
35cd713a
SF
2092
2093 # Breakable?
a523ec7c
SF
2094 if ( $dbline[$i] == 0 ) {
2095 print $OUT "Line $i not breakable.\n";
35cd713a
SF
2096 next CMD;
2097 }
2098
2099 # Yes. Set up the one-time-break sigil.
a523ec7c
SF
2100 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2101 _enable_breakpoint_temp_enabled_status($filename, $i);
35cd713a
SF
2102 } ## end if ($i)
2103
2104 # Turn off stack tracing from here up.
a523ec7c
SF
2105 for my $j (0 .. $stack_depth) {
2106 $stack[ $j ] &= ~1;
35cd713a
SF
2107 }
2108 last CMD;
2109 }
2110
2111 return;
2112}
2113
a4d311a3
SF
2114sub _DB__handle_forward_slash_command {
2115 my ($obj) = @_;
2116
2117 # The pattern as a string.
2118 use vars qw($inpat);
2119
2120 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2121
2122 # Remove the final slash.
2123 $inpat =~ s:([^\\])/$:$1:;
2124
2125 # If the pattern isn't null ...
2126 if ( $inpat ne "" ) {
2127
7e3426ea 2128 # Turn off warn and die processing for a bit.
a4d311a3
SF
2129 local $SIG{__DIE__};
2130 local $SIG{__WARN__};
2131
2132 # Create the pattern.
2133 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2134 if ( $@ ne "" ) {
2135
2136 # Oops. Bad pattern. No biscuit.
2137 # Print the eval error and go back for more
2138 # commands.
72c017e3 2139 print {$OUT} "$@";
a4d311a3
SF
2140 next CMD;
2141 }
2142 $obj->pat($inpat);
2143 } ## end if ($inpat ne "")
2144
2145 # Set up to stop on wrap-around.
2146 $end = $start;
2147
2148 # Don't move off the current line.
2149 $incr = -1;
2150
2151 my $pat = $obj->pat;
2152
2153 # Done in eval so nothing breaks if the pattern
2154 # does something weird.
2155 eval
2156 {
2157 no strict q/vars/;
2158 for (;;) {
2159 # Move ahead one line.
2160 ++$start;
2161
2162 # Wrap if we pass the last line.
72c017e3
SF
2163 if ($start > $max) {
2164 $start = 1;
2165 }
a4d311a3
SF
2166
2167 # Stop if we have gotten back to this line again,
2168 last if ($start == $end);
2169
2170 # A hit! (Note, though, that we are doing
2171 # case-insensitive matching. Maybe a qr//
2172 # expression would be better, so the user could
2173 # do case-sensitive matching if desired.
2174 if ($dbline[$start] =~ m/$pat/i) {
2175 if ($slave_editor) {
2176 # Handle proper escaping in the slave.
72c017e3 2177 print {$OUT} "\032\032$filename:$start:0\n";
a4d311a3
SF
2178 }
2179 else {
2180 # Just print the line normally.
72c017e3 2181 print {$OUT} "$start:\t",$dbline[$start],"\n";
a4d311a3
SF
2182 }
2183 # And quit since we found something.
2184 last;
2185 }
2186 }
2187 };
2188
2189 if ($@) {
2190 warn $@;
2191 }
2192
2193 # If we wrapped, there never was a match.
2194 if ( $start == $end ) {
2195 print {$OUT} "/$pat/: not found\n";
2196 }
2197 next CMD;
2198 }
2199
2200 return;
2201}
2202
11f0f050
SF
2203sub _DB__handle_question_mark_command {
2204 my ($obj) = @_;
2205
2206 # ? - backward pattern search.
2207 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2208
2209 # Get the pattern, remove trailing question mark.
2210 $inpat =~ s:([^\\])\?$:$1:;
2211
2212 # If we've got one ...
2213 if ( $inpat ne "" ) {
2214
2215 # Turn off die & warn handlers.
2216 local $SIG{__DIE__};
2217 local $SIG{__WARN__};
2218 eval '$inpat =~ m' . "\a$inpat\a";
2219
2220 if ( $@ ne "" ) {
2221
2222 # Ouch. Not good. Print the error.
2223 print $OUT $@;
2224 next CMD;
2225 }
2226 $obj->pat($inpat);
2227 } ## end if ($inpat ne "")
2228
2229 # Where we are now is where to stop after wraparound.
2230 $end = $start;
2231
2232 # Don't move away from this line.
2233 $incr = -1;
2234
2235 my $pat = $obj->pat;
2236 # Search inside the eval to prevent pattern badness
2237 # from killing us.
2238 eval {
2239 no strict q/vars/;
2240 for (;;) {
2241 # Back up a line.
2242 --$start;
2243
2244 # Wrap if we pass the first line.
2245
2246 $start = $max if ($start <= 0);
2247
2248 # Quit if we get back where we started,
2249 last if ($start == $end);
2250
2251 # Match?
2252 if ($dbline[$start] =~ m/$pat/i) {
2253 if ($slave_editor) {
2254 # Yep, follow slave editor requirements.
2255 print $OUT "\032\032$filename:$start:0\n";
2256 }
2257 else {
2258 # Yep, just print normally.
2259 print $OUT "$start:\t",$dbline[$start],"\n";
2260 }
2261
2262 # Found, so done.
2263 last;
2264 }
2265 }
2266 };
2267
2268 # Say we failed if the loop never found anything,
2269 if ( $start == $end ) {
2270 print {$OUT} "?$pat?: not found\n";
2271 }
2272 next CMD;
2273 }
2274
2275 return;
2276}
2277
5f166812
SF
2278sub _DB__handle_restart_and_rerun_commands {
2279 my ($obj) = @_;
2280
b9920278
SF
2281 my $cmd_cmd = $obj->cmd_verb;
2282 my $cmd_params = $obj->cmd_args;
5f166812
SF
2283 # R - restart execution.
2284 # rerun - controlled restart execution.
b9920278 2285 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
c59f1e04
SF
2286
2287 # Change directory to the initial current working directory on
2288 # the script startup, so if the debugged program changed the
2289 # directory, then we will still be able to find the path to the
2290 # the program. (perl 5 RT #121509 ).
2291 chdir ($_initial_cwd);
2292
5f166812
SF
2293 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2294
2295 # Close all non-system fds for a clean restart. A more
2296 # correct method would be to close all fds that were not
2297 # open when the process started, but this seems to be
2298 # hard. See "debugger 'R'estart and open database
2299 # connections" on p5p.
2300
2301 my $max_fd = 1024; # default if POSIX can't be loaded
2302 if (eval { require POSIX }) {
2303 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2304 }
2305
2306 if (defined $max_fd) {
2307 foreach ($^F+1 .. $max_fd-1) {
2308 next unless open FD_TO_CLOSE, "<&=$_";
2309 close(FD_TO_CLOSE);
2310 }
2311 }
2312
2313 # And run Perl again. We use exec() to keep the
2314 # PID stable (and that way $ini_pids is still valid).
2315 exec(@args) or print {$OUT} "exec failed: $!\n";
2316
2317 last CMD;
2318 }
2319
2320 return;
2321}
2322
33f361f5
SF
2323sub _DB__handle_run_command_in_pager_command {
2324 my ($obj) = @_;
2325
2326 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2327 if ( $pager =~ /^\|/ ) {
2328
2329 # Default pager is into a pipe. Redirect I/O.
2330 open( SAVEOUT, ">&STDOUT" )
b5679dc0 2331 || _db_warn("Can't save STDOUT");
33f361f5 2332 open( STDOUT, ">&OUT" )
b5679dc0 2333 || _db_warn("Can't redirect STDOUT");
33f361f5
SF
2334 } ## end if ($pager =~ /^\|/)
2335 else {
2336
2337 # Not into a pipe. STDOUT is safe.
b5679dc0 2338 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
33f361f5
SF
2339 }
2340
2341 # Fix up environment to record we have less if so.
2342 fix_less();
2343
2344 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2345
2346 # Couldn't open pipe to pager.
b5679dc0 2347 _db_warn("Can't pipe output to '$pager'");
33f361f5
SF
2348 if ( $pager =~ /^\|/ ) {
2349
2350 # Redirect I/O back again.
2351 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2352 || _db_warn("Can't restore DB::OUT");
33f361f5 2353 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2354 || _db_warn("Can't restore STDOUT");
33f361f5
SF
2355 close(SAVEOUT);
2356 } ## end if ($pager =~ /^\|/)
2357 else {
2358
2359 # Redirect I/O. STDOUT already safe.
2360 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2361 || _db_warn("Can't restore DB::OUT");
33f361f5
SF
2362 }
2363 next CMD;
2364 } ## end unless ($piped = open(OUT,...
2365
2366 # Set up broken-pipe handler if necessary.
2367 $SIG{PIPE} = \&DB::catch
2368 if $pager =~ /^\|/
2369 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2370
e0047406 2371 _autoflush(\*OUT);
33f361f5
SF
2372 # Save current filehandle, and put it back.
2373 $obj->selected(scalar( select(OUT) ));
2374 # Don't put it back if pager was a pipe.
2375 if ($cmd !~ /\A\|\|/)
2376 {
2377 select($obj->selected());
2378 $obj->selected("");
2379 }
2380
2381 # Trim off the pipe symbols and run the command now.
2382 $cmd =~ s#\A\|+\s*##;
2383 redo PIPE;
2384 }
2385
2386 return;
2387}
2388
321095c5
SF
2389sub _DB__handle_m_command {
2390 my ($obj) = @_;
2391
2392 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2393 methods($1);
2394 next CMD;
2395 }
2396
2397 # m expr - set up DB::eval to do the work
2398 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2399 $onetimeDump = 'methods'; # method output gets used there
2400 }
2401
2402 return;
2403}
33f361f5 2404
8e4cceb9
SF
2405sub _DB__at_end_of_every_command {
2406 my ($obj) = @_;
2407
2408 # At the end of every command:
2409 if ($obj->piped) {
2410
2411 # Unhook the pipe mechanism now.
2412 if ( $pager =~ /^\|/ ) {
2413
2414 # No error from the child.
2415 $? = 0;
2416
2417 # we cannot warn here: the handle is missing --tchrist
2418 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2419
2420 # most of the $? crud was coping with broken cshisms
2421 # $? is explicitly set to 0, so this never runs.
2422 if ($?) {
2423 print SAVEOUT "Pager '$pager' failed: ";
2424 if ( $? == -1 ) {
2425 print SAVEOUT "shell returned -1\n";
2426 }
2427 elsif ( $? >> 8 ) {
2428 print SAVEOUT ( $? & 127 )
2429 ? " (SIG#" . ( $? & 127 ) . ")"
2430 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2431 }
2432 else {
2433 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2434 }
2435 } ## end if ($?)
2436
2437 # Reopen filehandle for our output (if we can) and
2438 # restore STDOUT (if we can).
b5679dc0 2439 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9 2440 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2441 || _db_warn("Can't restore STDOUT");
8e4cceb9
SF
2442
2443 # Turn off pipe exception handler if necessary.
2444 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2445
2446 # Will stop ignoring SIGPIPE if done like nohup(1)
2447 # does SIGINT but Perl doesn't give us a choice.
2448 } ## end if ($pager =~ /^\|/)
2449 else {
2450
2451 # Non-piped "pager". Just restore STDOUT.
b5679dc0 2452 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9
SF
2453 }
2454
9b534162
HH
2455 # Let Readline know about the new filehandles.
2456 reset_IN_OUT( \*IN, \*OUT );
2457
8e4cceb9
SF
2458 # Close filehandle pager was using, restore the normal one
2459 # if necessary,
2460 close(SAVEOUT);
2461
2462 if ($obj->selected() ne "") {
2463 select($obj->selected);
2464 $obj->selected("");
2465 }
2466
2467 # No pipes now.
2468 $obj->piped("");
2469 } ## end if ($piped)
2470
2471 return;
2472}
2473
5f5eab52
SF
2474sub _DB__handle_watch_expressions
2475{
2476 my $self = shift;
2477
2478 if ( $DB::trace & 2 ) {
2479 for my $n (0 .. $#DB::to_watch) {
2480 $DB::evalarg = $DB::to_watch[$n];
2481 local $DB::onetimeDump; # Tell DB::eval() to not output results
2482
2483 # Fix context DB::eval() wants to return an array, but
2484 # we need a scalar here.
2485 my ($val) = join( "', '", DB::eval(@_) );
2486 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2487
2488 # Did it change?
2489 if ( $val ne $DB::old_watch[$n] ) {
2490
2491 # Yep! Show the difference, and fake an interrupt.
2492 $DB::signal = 1;
2493 print {$DB::OUT} <<EOP;
2494Watchpoint $n:\t$DB::to_watch[$n] changed:
2495 old value:\t$DB::old_watch[$n]
2496 new value:\t$val
2497EOP
2498 $DB::old_watch[$n] = $val;
2499 } ## end if ($val ne $old_watch...
2500 } ## end for my $n (0 ..
2501 } ## end if ($trace & 2)
2502
2503 return;
2504}
2505
47e3b8cc
SF
2506# 't' is type.
2507# 'm' is method.
2508# 'v' is the value (i.e: method name or subroutine ref).
2509# 's' is subroutine.
23053931
SF
2510my %cmd_lookup;
2511
2512BEGIN
2513{
2514 %cmd_lookup =
47e3b8cc 2515(
c9a9a6c0 2516 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2517 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2518 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2519 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2520 'S' => { t => 'm', v => '_handle_S_command', },
2521 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2522 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2523 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2524 'f' => { t => 's', v => \&_DB__handle_f_command, },
2525 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2526 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2527 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2528 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2529 'r' => { t => 'm', v => '_handle_r_command', },
2530 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2531 'save' => { t => 'm', v => '_handle_save_command', },
2532 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2533 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2534 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2535 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2536 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2537 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2538 ('X', 'V')),
8f144dfc
SF
2539 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2540 qw(enable disable)),
2541 (map { $_ =>
2542 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2543 } qw(R rerun)),
fbe9ebae 2544 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
ce1a6808 2545 qw(a A b B e E h i l L M o O v w W)),
47e3b8cc 2546);
23053931 2547};
47e3b8cc 2548
2b0b9dd1
SF
2549sub DB {
2550
2551 # lock the debugger and get the thread id for the prompt
2552 lock($DBGR);
2553 my $tid;
2554 my $position;
2555 my ($prefix, $after, $infix);
2556 my $pat;
22fc883d 2557 my $explicit_stop;
33f361f5
SF
2558 my $piped;
2559 my $selected;
2b0b9dd1
SF
2560
2561 if ($ENV{PERL5DB_THREADED}) {
2562 $tid = eval { "[".threads->tid."]" };
2563 }
2564
610f01b9 2565 my $cmd_verb;
3249b113 2566 my $cmd_args;
35cd713a 2567
22fc883d
SF
2568 my $obj = DB::Obj->new(
2569 {
2570 position => \$position,
2571 prefix => \$prefix,
2572 after => \$after,
2573 explicit_stop => \$explicit_stop,
2574 infix => \$infix,
3249b113 2575 cmd_args => \$cmd_args,
610f01b9 2576 cmd_verb => \$cmd_verb,
a4d311a3 2577 pat => \$pat,
33f361f5
SF
2578 piped => \$piped,
2579 selected => \$selected,
22fc883d
SF
2580 },
2581 );
2582
2583 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2584
69893cff
RGS
2585 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2586 # The code being debugged may have altered them.
b0b8faca 2587 DB::save();
69893cff
RGS
2588
2589 # Since DB::DB gets called after every line, we can use caller() to
2590 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2591 # caller is returning all the extra information when called from the
69893cff 2592 # debugger.
e22ea7cc 2593 local ( $package, $filename, $line ) = caller;
6b24a4b7 2594 $filename_ini = $filename;
69893cff
RGS
2595
2596 # set up the context for DB::eval, so it can properly execute
2597 # code on behalf of the user. We add the package in so that the
2598 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2599 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2600
2601 # Create an alias to the active file magical array to simplify
2602 # the code here.
e22ea7cc 2603 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2604
69893cff 2605 # Last line in the program.
55783941 2606 $max = $#dbline;
69893cff 2607
e0cd3692
SF
2608 # The &-call is here to ascertain the mutability of @_.
2609 &_DB__determine_if_we_should_break;
69893cff
RGS
2610
2611 # Preserve the current stop-or-not, and see if any of the W
2612 # (watch expressions) has changed.
36477c24 2613 my $was_signal = $signal;
69893cff
RGS
2614
2615 # If we have any watch expressions ...
5f5eab52 2616 _DB__handle_watch_expressions($obj);
69893cff
RGS
2617
2618=head2 C<watchfunction()>
2619
2620C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2621function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2622current package, filename, and line as its parameters.
2623
b570d64b 2624The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2625debugger's context, so it has access to all of the debugger's internal
2626data structures and functions.
2627
2628C<watchfunction()> can control the debugger's actions. Any of the following
2629will cause the debugger to return control to the user's program after
2630C<watchfunction()> executes:
2631
b570d64b 2632=over 4
69893cff 2633
be9a9b1d
AT
2634=item *
2635
2636Returning a false value from the C<watchfunction()> itself.
2637
2638=item *
2639
2640Altering C<$single> to a false value.
2641
2642=item *
69893cff 2643
be9a9b1d 2644Altering C<$signal> to a false value.
69893cff 2645
be9a9b1d 2646=item *
69893cff 2647
be9a9b1d 2648Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2649check for C<watchfunction()>. This can be done with
2650
2651 $trace &= ~4;
2652
2653=back
2654
2655=cut
2656
e22ea7cc 2657 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2658 # current package, filename, and line. The function executes in
2659 # the DB:: package.
e22ea7cc
RF
2660 if ( $trace & 4 ) { # User-installed watch
2661 return
2662 if watchfunction( $package, $filename, $line )
2663 and not $single
2664 and not $was_signal
2665 and not( $trace & ~4 );
69893cff
RGS
2666 } ## end if ($trace & 4)
2667
e22ea7cc 2668 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2669 # turn off the signal now.
6027b9a3 2670 $was_signal = $signal;
69893cff
RGS
2671 $signal = 0;
2672
2673=head2 GETTING READY TO EXECUTE COMMANDS
2674
2675The debugger decides to take control if single-step mode is on, the
2676C<t> command was entered, or the user generated a signal. If the program
2677has fallen off the end, we set things up so that entering further commands
2678won't cause trouble, and we say that the program is over.
2679
2680=cut
2681
8dc67a69
SF
2682 # Make sure that we always print if asked for explicitly regardless
2683 # of $trace_to_depth .
22fc883d 2684 $explicit_stop = ($single || $was_signal);
8dc67a69 2685
69893cff
RGS
2686 # Check to see if we should grab control ($single true,
2687 # trace set appropriately, or we got a signal).
8dc67a69 2688 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2689 $obj->_DB__grab_control(@_);
69893cff
RGS
2690 } ## end if ($single || ($trace...
2691
2692=pod
2693
2694If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2695If there are any preprompt actions, execute those as well.
e219e2fb
RF
2696
2697=cut
2698
69893cff 2699 # If there's an action, do it now.
05da04df
SF
2700 if ($action) {
2701 $evalarg = $action;
e0cd3692
SF
2702 # The &-call is here to ascertain the mutability of @_.
2703 &DB::eval;
05da04df 2704 }
e219e2fb 2705
69893cff
RGS
2706 # Are we nested another level (e.g., did we evaluate a function
2707 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2708 if ( $single || $was_signal ) {
2709
69893cff 2710 # Yes, go down a level.
e22ea7cc 2711 local $level = $level + 1;
69893cff
RGS
2712
2713 # Do any pre-prompt actions.
e22ea7cc 2714 foreach $evalarg (@$pre) {
e0cd3692
SF
2715 # The &-call is here to ascertain the mutability of @_.
2716 &DB::eval;
e22ea7cc 2717 }
69893cff
RGS
2718
2719 # Complain about too much recursion if we passed the limit.
05da04df
SF
2720 if ($single & 4) {
2721 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2722 }
69893cff
RGS
2723
2724 # The line we're currently on. Set $incr to -1 to stay here
2725 # until we get a command that tells us to advance.
e22ea7cc
RF
2726 $start = $line;
2727 $incr = -1; # for backward motion.
69893cff
RGS
2728
2729 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2730 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2731
2732=head2 WHERE ARE WE?
2733
2734XXX Relocate this section?
2735
2736The debugger normally shows the line corresponding to the current line of
2737execution. Sometimes, though, we want to see the next line, or to move elsewhere
2738in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2739
be9a9b1d
AT
2740C<$incr> controls by how many lines the I<current> line should move forward
2741after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2742line shouldn't change.
2743
be9a9b1d 2744C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2745move forwards or backwards from when doing an C<L> or C<-> command.
2746
2747C<$max> tells the debugger where the last line of the current file is. It's
2748used to terminate loops most often.
2749
2750=head2 THE COMMAND LOOP
2751
2752Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2753in two parts:
2754
2755=over 4
2756
be9a9b1d
AT
2757=item *
2758
2759The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2760reads a command and then executes it.
2761
be9a9b1d
AT
2762=item *
2763
2764The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2765is wholly contained inside the C<CMD> block and only executes a command.
2766Used to handle commands running inside a pager.
2767
2768=back
2769
2770So why have two labels to restart the loop? Because sometimes, it's easier to
2771have a command I<generate> another command and then re-execute the loop to do
2772the new command. This is faster, but perhaps a bit more convoluted.
2773
2774=cut
2775
2776 # The big command dispatch loop. It keeps running until the
2777 # user yields up control again.
2778 #
2779 # If we have a terminal for input, and we get something back
2780 # from readline(), keep on processing.
6b24a4b7 2781
e22ea7cc 2782 CMD:
32bbadc6 2783 while (_DB__read_next_cmd($tid))
69893cff 2784 {
e22ea7cc 2785
8380a245 2786 share($cmd);
69893cff
RGS
2787 # ... try to execute the input as debugger commands.
2788
2789 # Don't stop running.
2790 $single = 0;
2791
2792 # No signal is active.
2793 $signal = 0;
2794
2795 # Handle continued commands (ending with \):
3d7a2a93 2796 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2797 $cmd .= DB::readline(" cont: ");
e22ea7cc 2798 redo CMD;
3d7a2a93 2799 }
69893cff
RGS
2800
2801=head4 The null command
2802
be9a9b1d 2803A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2804command out of C<$laststep> (where it was recorded previously), and copy it
2805back into C<$cmd> to be executed below. If there wasn't any previous command,
2806we'll do nothing below (no command will match). If there was, we also save it
2807in the command history and fall through to allow the command parsing to pick
2808it up.
2809
2810=cut
2811
2812 # Empty input means repeat the last command.
eeb7da96
SF
2813 if ($cmd eq '') {
2814 $cmd = $laststep;
2815 }
e22ea7cc 2816 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2817 if (length($cmd) >= 2) {
2818 push( @hist, $cmd );
2819 }
e22ea7cc 2820 push( @truehist, $cmd );
2dbd01ad
SF
2821 share(@hist);
2822 share(@truehist);
e22ea7cc
RF
2823
2824 # This is a restart point for commands that didn't arrive
2825 # via direct user input. It allows us to 'redo PIPE' to
2826 # re-execute command processing without reading a new command.
69893cff 2827 PIPE: {
af84fb69 2828 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2829
2830=head3 COMMAND ALIASES
2831
2832The debugger can create aliases for commands (these are stored in the
2833C<%alias> hash). Before a command is executed, the command loop looks it up
2834in the alias hash and substitutes the contents of the alias for the command,
2835completely replacing it.
2836
2837=cut
2838
2839 # See if there's an alias for the command, and set it up if so.
610f01b9 2840 if ( $alias{$cmd_verb} ) {
e22ea7cc 2841
69893cff
RGS
2842 # Squelch signal handling; we want to keep control here
2843 # if something goes loco during the alias eval.
2844 local $SIG{__DIE__};
2845 local $SIG{__WARN__};
2846
2847 # This is a command, so we eval it in the DEBUGGER's
2848 # scope! Otherwise, we can't see the special debugger
2849 # variables, or get to the debugger's subs. (Well, we
2850 # _could_, but why make it even more complicated?)
610f01b9 2851 eval "\$cmd =~ $alias{$cmd_verb}";
69893cff
RGS
2852 if ($@) {
2853 local $\ = '';
610f01b9 2854 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
69893cff
RGS
2855 next CMD;
2856 }
af84fb69 2857 _DB__trim_command_and_return_first_component($obj);
610f01b9 2858 } ## end if ($alias{$cmd_verb})
69893cff
RGS
2859
2860=head3 MAIN-LINE COMMANDS
2861
2862All of these commands work up to and after the program being debugged has
b570d64b 2863terminated.
69893cff
RGS
2864
2865=head4 C<q> - quit
2866
b570d64b 2867Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2868try to execute further, cleaning any restart-related stuff out of the
2869environment, and executing with the last value of C<$?>.
2870
2871=cut
2872
fbe9ebae
SF
2873 # All of these commands were remapped in perl 5.8.0;
2874 # we send them off to the secondary dispatcher (see below).
2875 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2876 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2877
610f01b9 2878 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
47e3b8cc
SF
2879 my $type = $cmd_rec->{t};
2880 my $val = $cmd_rec->{v};
2881 if ($type eq 'm') {
2882 $obj->$val();
2883 }
2884 elsif ($type eq 's') {
2885 $val->($obj);
2886 }
2887 }
69893cff 2888
611272bb 2889=head4 C<t> - trace [n]
69893cff
RGS
2890
2891Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2892If level is specified, set C<$trace_to_depth>.
69893cff 2893
69893cff
RGS
2894=head4 C<S> - list subroutines matching/not matching a pattern
2895
2896Walks through C<%sub>, checking to see whether or not to print the name.
2897
69893cff
RGS
2898=head4 C<X> - list variables in current package
2899
b570d64b 2900Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2901appropriate C<V> command and fall through.
2902
69893cff
RGS
2903=head4 C<V> - list variables
2904
b570d64b 2905Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2906
69893cff
RGS
2907=head4 C<x> - evaluate and print an expression
2908
2909Hands the expression off to C<DB::eval>, setting it up to print the value
2910via C<dumpvar.pl> instead of just printing it directly.
2911
69893cff
RGS
2912=head4 C<m> - print methods
2913
2914Just uses C<DB::methods> to determine what methods are available.
2915
69893cff
RGS
2916=head4 C<f> - switch files
2917
73decac7 2918Switch to a different filename.
69893cff 2919
69893cff
RGS
2920=head4 C<.> - return to last-executed line.
2921
2922We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2923and then we look up the line in the magical C<%dbline> hash.
2924
69893cff
RGS
2925=head4 C<-> - back one window
2926
2927We change C<$start> to be one window back; if we go back past the first line,
2928we set it to be the first line. We ser C<$incr> to put us back at the
2929currently-executing line, and then put a C<l $start +> (list one window from
2930C<$start>) in C<$cmd> to be executed later.
2931
8481f647 2932=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2933
2934In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2935problems, most notably that the default case of several commands destroying
2936the user's work in setting watchpoints, actions, etc. We wanted, however, to
2937retain the old commands for those who were used to using them or who preferred
2938them. At this point, we check for the new commands and call C<cmd_wrapper> to
2939deal with them instead of processing them in-line.
2940
69893cff
RGS
2941=head4 C<y> - List lexicals in higher scope
2942
826b9a2e 2943Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2944above the current one and then displays then using C<dumpvar.pl>.
2945
69893cff
RGS
2946=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2947
2948All of the commands below this point don't work after the program being
2949debugged has ended. All of them check to see if the program has ended; this
2950allows the commands to be relocated without worrying about a 'line of
2951demarcation' above which commands can be entered anytime, and below which
2952they can't.
2953
2954=head4 C<n> - single step, but don't trace down into subs
2955
2956Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2957when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2958so a null command knows what to re-execute.
69893cff 2959
69893cff
RGS
2960=head4 C<s> - single-step, entering subs
2961
826b9a2e 2962Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2963subs. Also saves C<s> as C<$lastcmd>.
2964
69893cff
RGS
2965=head4 C<c> - run continuously, setting an optional breakpoint
2966
2967Most of the code for this command is taken up with locating the optional
2968breakpoint, which is either a subroutine name or a line number. We set
2969the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2970in this and all call levels above this one.
2971
69893cff
RGS
2972=head4 C<r> - return from a subroutine
2973
2974For C<r> to work properly, the debugger has to stop execution again
2975immediately after the return is executed. This is done by forcing
2976single-stepping to be on in the call level above the current one. If
2977we are printing return values when a C<r> is executed, set C<$doret>
2978appropriately, and force us out of the command loop.
2979
69893cff
RGS
2980=head4 C<T> - stack trace
2981
2982Just calls C<DB::print_trace>.
2983
69893cff
RGS
2984=head4 C<w> - List window around current line.
2985
2986Just calls C<DB::cmd_w>.
2987
69893cff
RGS
2988=head4 C<W> - watch-expression processing.
2989
b570d64b 2990Just calls C<DB::cmd_W>.
69893cff 2991
69893cff
RGS
2992=head4 C</> - search forward for a string in the source
2993
ef18ae63 2994We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2995bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2996If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2997mess us up.
2998
2999=cut
3000
a4d311a3 3001 _DB__handle_forward_slash_command($obj);
69893cff
RGS
3002
3003=head4 C<?> - search backward for a string in the source
3004
3005Same as for C</>, except the loop runs backwards.
3006
3007=cut
3008
11f0f050 3009 _DB__handle_question_mark_command($obj);
69893cff
RGS
3010
3011=head4 C<$rc> - Recall command
3012
3013Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
7e3426ea 3014that the terminal supports history). It finds the command required, puts it
69893cff
RGS
3015into C<$cmd>, and redoes the loop to execute it.
3016
3017=cut
3018
e22ea7cc 3019 # $rc - recall command.
14f38b27 3020 $obj->_handle_rc_recall_command;
69893cff
RGS
3021
3022=head4 C<$sh$sh> - C<system()> command
3023
f0bb1409 3024Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
69893cff
RGS
3025C<STDOUT> from getting messed up.
3026
3027=cut
3028
466f24c7 3029 $obj->_handle_sh_command;
69893cff
RGS
3030
3031=head4 C<$rc I<pattern> $rc> - Search command history
3032
3033Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3034If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3035
3036=cut
3037
0d2c714c 3038 $obj->_handle_rc_search_history_command;
69893cff 3039
ef18ae63 3040=head4 C<$sh> - Invoke a shell
69893cff 3041
f0bb1409 3042Uses C<_db_system()> to invoke a shell.
69893cff
RGS
3043
3044=cut
3045
69893cff
RGS
3046=head4 C<$sh I<command>> - Force execution of a command in a shell
3047
3048Like the above, but the command is passed to the shell. Again, we use
f0bb1409 3049C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
69893cff 3050
69893cff
RGS
3051=head4 C<H> - display commands in history
3052
3053Prints the contents of C<@hist> (if any).
3054
69893cff
RGS
3055=head4 C<man, doc, perldoc> - look up documentation
3056
3057Just calls C<runman()> to print the appropriate document.
3058
3059=cut
3060
c7b0c61d 3061 $obj->_handle_doc_command;
69893cff
RGS
3062
3063=head4 C<p> - print
3064
3065Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3066the bottom of the loop.
3067
69893cff
RGS
3068=head4 C<=> - define command alias
3069
3070Manipulates C<%alias> to add or list command aliases.
3071
69893cff
RGS
3072=head4 C<source> - read commands from a file.
3073
3074Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3075pick it up.
3076
d0ecd4f3 3077=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 3078
d0ecd4f3 3079This enables or disables breakpoints.
e09195af 3080
69893cff
RGS
3081=head4 C<save> - send current history to a file
3082
3083Takes the complete history, (not the shrunken version you see with C<H>),
3084and saves it to the given filename, so it can be replayed using C<source>.
3085
3086Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3087
7fddc82f
RF
3088=head4 C<R> - restart
3089
ef18ae63 3090Restart the debugger session.
7fddc82f
RF
3091
3092=head4 C<rerun> - rerun the current session
3093
3094Return to any given position in the B<true>-history list
3095
69893cff
RGS
3096=head4 C<|, ||> - pipe output through the pager.
3097
be9a9b1d 3098For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3099(the program's standard output). For C<||>, we only save C<OUT>. We open a
3100pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3101is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3102set C<$signal>, sending us back into the debugger.
3103
3104We then trim off the pipe symbols and C<redo> the command loop at the
3105C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3106reading another.
3107
3108=cut
3109
3110 # || - run command in the pager, with output to DB::OUT.
33f361f5 3111 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3112
3113=head3 END OF COMMAND PARSING
3114
ff41e38d
SF
3115Anything left in C<$cmd> at this point is a Perl expression that we want to
3116evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3117any variables we might want to address in the C<DB> package.
3118
3119=cut
3120
e22ea7cc 3121 } # PIPE:
69893cff 3122
e2b8b3e7
TC
3123 # trace an expression
3124 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3125
e22ea7cc 3126 # Make sure the flag that says "the debugger's running" is
69893cff 3127 # still on, to make sure we get control again.
e22ea7cc 3128 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3129
3130 # Run *our* eval that executes in the caller's context.
e0cd3692
SF
3131 # The &-call is here to ascertain the mutability of @_.
3132 &DB::eval;
69893cff
RGS
3133
3134 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3135 if ($onetimeDump) {
3136 $onetimeDump = undef;
69893cff 3137 $onetimedumpDepth = undef;
e22ea7cc
RF
3138 }
3139 elsif ( $term_pid == $$ ) {
8380a245 3140 eval { # May run under miniperl, when not available...
c7e68384
IZ
3141 STDOUT->flush();
3142 STDERR->flush();
8380a245 3143 };
e22ea7cc 3144
69893cff 3145 # XXX If this is the master pid, print a newline.
8380a245 3146 print {$OUT} "\n";
e22ea7cc
RF
3147 }
3148 } ## end while (($term || &setterm...
69893cff
RGS
3149
3150=head3 POST-COMMAND PROCESSING
3151
3152After each command, we check to see if the command output was piped anywhere.
3153If so, we go through the necessary code to unhook the pipe and go back to
3154our standard filehandles for input and output.
3155
3156=cut
3157
e22ea7cc 3158 continue { # CMD:
8e4cceb9 3159 _DB__at_end_of_every_command($obj);
e22ea7cc 3160 } # CMD:
69893cff
RGS
3161
3162=head3 COMMAND LOOP TERMINATION
3163
3164When commands have finished executing, we come here. If the user closed the
3165input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3166evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3167C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3168The interpreter will then execute the next line and then return control to us
3169again.
3170
3171=cut
3172
3173 # No more commands? Quit.
1f874cb6 3174 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3175
3176 # Evaluate post-prompt commands.
e22ea7cc 3177 foreach $evalarg (@$post) {
e0cd3692
SF
3178 # The &-call is here to ascertain the mutability of @_.
3179 &DB::eval;
e22ea7cc
RF
3180 }
3181 } # if ($single || $signal)
69893cff
RGS
3182
3183 # Put the user's globals back where you found them.
e22ea7cc 3184 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3185 ();
3186} ## end sub DB
3187
90fd4c80
KF
3188# Because DB::Obj is used above,
3189#
3190# my $obj = DB::Obj->new(
3191#
7e3426ea 3192# The following package declaration must come before that,
90fd4c80
KF
3193# or else runtime errors will occur with
3194#
3195# PERLDB_OPTS="autotrace nonstop"
3196#
3197# ( rt#116771 )
3198BEGIN {
3199
22fc883d
SF
3200package DB::Obj;
3201
3202sub new {
3203 my $class = shift;
3204
3205 my $self = bless {}, $class;
3206
3207 $self->_init(@_);
3208
3209 return $self;
3210}
3211
3212sub _init {
3213 my ($self, $args) = @_;
3214
3215 %{$self} = (%$self, %$args);
3216
3217 return;
3218}
3219
3220{
3221 no strict 'refs';
a4d311a3 3222 foreach my $slot_name (qw(
610f01b9 3223 after explicit_stop infix pat piped position prefix selected cmd_verb
3249b113 3224 cmd_args
a4d311a3 3225 )) {
22fc883d
SF
3226 my $slot = $slot_name;
3227 *{$slot} = sub {
3228 my $self = shift;
3229
3230 if (@_) {
3231 ${ $self->{$slot} } = shift;
3232 }
3233
3234 return ${ $self->{$slot} };
3235 };
8def6eff
SF
3236
3237 *{"append_to_$slot"} = sub {
3238 my $self = shift;
3239 my $s = shift;
3240
3241 return $self->$slot($self->$slot . $s);
3242 };
22fc883d
SF
3243 }
3244}
3245
3246sub _DB_on_init__initialize_globals
3247{
3248 my $self = shift;
3249
3250 # Check for whether we should be running continuously or not.
3251 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3252 if ( $single and not $second_time++ ) {
22fc883d
SF
3253
3254 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3255 if ($runnonstop) { # Disable until signal
22fc883d
SF
3256 # If there's any call stack in place, turn off single
3257 # stepping into subs throughout the stack.
8ad70697
SF
3258 for my $i (0 .. $stack_depth) {
3259 $stack[ $i ] &= ~1;
22fc883d
SF
3260 }
3261
3262 # And we are now no longer in single-step mode.
ebd0282e 3263 $single = 0;
22fc883d
SF
3264
3265 # If we simply returned at this point, we wouldn't get
3266 # the trace info. Fall on through.
3267 # return;
3268 } ## end if ($runnonstop)
3269
8ad70697 3270 elsif ($ImmediateStop) {
22fc883d
SF
3271
3272 # We are supposed to stop here; XXX probably a break.
8ad70697 3273 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3274 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3275 # us into the command loop
3276 }
3277 } ## end if ($single and not $second_time...
3278
3279 # If we're in single-step mode, or an interrupt (real or fake)
3280 # has occurred, turn off non-stop mode.
ebd0282e 3281 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3282
3283 return;
3284}
3285
ad46ac70
SF
3286sub _my_print_lineinfo
3287{
3288 my ($self, $i, $incr_pos) = @_;
3289
18b5b545 3290 if ($frame) {
ad46ac70 3291 # Print it indented if tracing is on.
8ad70697 3292 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3293 "$i:\t$DB::dbline[$i]" . $self->after );
3294 }
3295 else {
3296 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3297 }
3298}
3299
44a07e3e 3300sub _curr_line {
18b5b545 3301 return $DB::dbline[$line];
44a07e3e
SF
3302}
3303
601c6a23
SF
3304sub _is_full {
3305 my ($self, $letter) = @_;
3306
3307 return ($DB::cmd eq $letter);
3308}
3309
22fc883d
SF
3310sub _DB__grab_control
3311{
3312 my $self = shift;
3313
3314 # Yes, grab control.
7793e5c2 3315 if ($slave_editor) {
22fc883d
SF
3316
3317 # Tell the editor to update its position.
18b5b545 3318 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3319 DB::print_lineinfo($self->position());
3320 }
3321
3322=pod
3323
3324Special check: if we're in package C<DB::fake>, we've gone through the
3325C<END> block at least once. We set up everything so that we can continue
3326to enter commands and have a valid context to be in.
3327
3328=cut
3329
3330 elsif ( $DB::package eq 'DB::fake' ) {
3331
3332 # Fallen off the end already.
3333 if (!$DB::term) {
3334 DB::setterm();
3335 }
3336
3337 DB::print_help(<<EOP);
3338Debugged program terminated. Use B<q> to quit or B<R> to restart,
3339use B<o> I<inhibit_exit> to avoid stopping after program termination,
3340B<h q>, B<h R> or B<h o> to get additional info.
3341EOP
3342
3343 # Set the DB::eval context appropriately.
0b1fcdcc
SF
3344 # At program termination disable any user actions.
3345 $DB::action = undef;
3346
22fc883d
SF
3347 $DB::package = 'main';
3348 $DB::usercontext = DB::_calc_usercontext($DB::package);
3349 } ## end elsif ($package eq 'DB::fake')
3350
3351=pod
3352
3353If the program hasn't finished executing, we scan forward to the
3354next executable line, print that out, build the prompt from the file and line
3355number information, and print that.
3356
3357=cut
3358
3359 else {
3360
3361
3362 # Still somewhere in the midst of execution. Set up the
3363 # debugger prompt.
3364 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3365 # Perl 5 ones (sorry, we don't print Klingon
3366 #module names)
3367
3368 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3369 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3370 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3371
3372 # Break up the prompt if it's really long.
3373 if ( length($self->prefix()) > 30 ) {
18b5b545 3374 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3375 $self->prefix("");
3376 $self->infix(":\t");
3377 }
3378 else {
3379 $self->infix("):\t");
3380 $self->position(
18b5b545 3381 $self->prefix . $line. $self->infix
44a07e3e 3382 . $self->_curr_line . $self->after
22fc883d
SF
3383 );
3384 }
3385
3386 # Print current line info, indenting if necessary.
18b5b545 3387 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3388
44a07e3e
SF
3389 my $i;
3390 my $line_i = sub { return $DB::dbline[$i]; };
3391
22fc883d
SF
3392 # Scan forward, stopping at either the end or the next
3393 # unbreakable line.
18b5b545 3394 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3395 { #{ vi
3396
3397 # Drop out on null statements, block closers, and comments.
44a07e3e 3398 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3399
3400 # Drop out if the user interrupted us.
ebd0282e 3401 last if $signal;
22fc883d
SF
3402
3403 # Append a newline if the line doesn't have one. Can happen
3404 # in eval'ed text, for instance.
44a07e3e 3405 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3406
3407 # Next executable line.
44a07e3e 3408 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3409 . $self->after;
8def6eff 3410 $self->append_to_position($incr_pos);
ad46ac70 3411 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3412 } ## end for ($i = $line + 1 ; $i...
3413 } ## end else [ if ($slave_editor)
3414
3415 return;
3416}
3417
174f9c5e 3418sub _handle_t_command {
9875a6d2
SF
3419 my $self = shift;
3420
3421 my $levels = $self->cmd_args();
3422
3423 if ((!length($levels)) or ($levels !~ /\D/)) {
931ac036 3424 $trace ^= 1;
174f9c5e 3425 local $\ = '';
8ad70697
SF
3426 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3427 print {$OUT} "Trace = "
931ac036 3428 . ( ( $trace & 1 )
174f9c5e
SF
3429 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3430 : "off" ) . "\n";
3431 next CMD;
3432 }
3433
3434 return;
3435}
3436
9d0b71b3
SF
3437
3438sub _handle_S_command {
3249b113
SF
3439 my $self = shift;
3440
9d0b71b3 3441 if (my ($print_all_subs, $should_reverse, $Spatt)
3249b113 3442 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
9d0b71b3
SF
3443 # $Spatt is the pattern (if any) to use.
3444 # Reverse scan?
3445 my $Srev = defined $should_reverse;
3446 # No args - print all subs.
3447 my $Snocheck = !defined $print_all_subs;
3448
3449 # Need to make these sane here.
3450 local $\ = '';
3451 local $, = '';
3452
3453 # Search through the debugger's magical hash of subs.
3454 # If $nocheck is true, just print the sub name.
3455 # Otherwise, check it against the pattern. We then use
3456 # the XOR trick to reverse the condition as required.
3457 foreach $subname ( sort( keys %sub ) ) {
3458 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3459 print $OUT $subname, "\n";
3460 }
3461 }
3462 next CMD;
3463 }
3464
3465 return;
3466}
3467
1ce985d2 3468sub _handle_V_command_and_X_command {
601c6a23 3469 my $self = shift;
1ce985d2
SF
3470
3471 $DB::cmd =~ s/^X\b/V $DB::package/;
3472
3473 # Bare V commands get the currently-being-debugged package
3474 # added.
601c6a23 3475 if ($self->_is_full('V')) {
1ce985d2
SF
3476 $DB::cmd = "V $DB::package";
3477 }
3478
3479 # V - show variables in package.
3480 if (my ($new_packname, $new_vars_str) =
3481 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3482
3483 # Save the currently selected filehandle and
3484 # force output to debugger's filehandle (dumpvar
3485 # just does "print" for output).
3486 my $savout = select($OUT);
3487
3488 # Grab package name and variables to dump.
3489 $packname = $new_packname;
3490 my @vars = split( ' ', $new_vars_str );
3491
3492 # If main::dumpvar isn't here, get it.
3493 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3494 if ( defined &main::dumpvar ) {
3495
3496 # We got it. Turn off subroutine entry/exit messages
3497 # for the moment, along with return values.
3498 local $frame = 0;
3499 local $doret = -2;
3500
3501 # must detect sigpipe failures - not catching
3502 # then will cause the debugger to die.
3503 eval {
b0b8faca 3504 main::dumpvar(
1ce985d2
SF
3505 $packname,
3506 defined $option{dumpDepth}
3507 ? $option{dumpDepth}
3508 : -1, # assume -1 unless specified
3509 @vars
3510 );
3511 };
3512
3513 # The die doesn't need to include the $@, because
3514 # it will automatically get propagated for us.
3515 if ($@) {
3516 die unless $@ =~ /dumpvar print failed/;
3517 }
3518 } ## end if (defined &main::dumpvar)
3519 else {
3520
3521 # Couldn't load dumpvar.
3522 print $OUT "dumpvar.pl not available.\n";
3523 }
3524
3525 # Restore the output filehandle, and go round again.
3526 select($savout);
3527 next CMD;
3528 }
3529
3530 return;
3531}
3532
d1450c23 3533sub _handle_dash_command {
601c6a23 3534 my $self = shift;
d1450c23 3535
601c6a23 3536 if ($self->_is_full('-')) {
d1450c23
SF
3537
3538 # back up by a window; go to 1 if back too far.
3539 $start -= $incr + $window + 1;
3540 $start = 1 if $start <= 0;
3541 $incr = $window - 1;
3542
3543 # Generate and execute a "l +" command (handled below).
3544 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3545 redo CMD;
d1450c23
SF
3546 }
3547 return;
3548}
3549
cb9d1513
SF
3550sub _n_or_s_commands_generic {
3551 my ($self, $new_val) = @_;
73c5e526 3552 # n - next
cb9d1513 3553 next CMD if DB::_DB__is_finished();
73c5e526 3554
cb9d1513
SF
3555 # Single step, but don't enter subs.
3556 $single = $new_val;
3557
3558 # Save for empty command (repeat last).
3559 $laststep = $DB::cmd;
3560 last CMD;
3561}
73c5e526 3562
cb9d1513
SF
3563sub _n_or_s {
3564 my ($self, $letter, $new_val) = @_;
3565
601c6a23 3566 if ($self->_is_full($letter)) {
cb9d1513 3567 $self->_n_or_s_commands_generic($new_val);
73c5e526 3568 }
a30f63cd 3569 else {
50a8a759
SF
3570 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3571 }
73c5e526
SF
3572
3573 return;
3574}
3575
cb9d1513
SF
3576sub _handle_n_command {
3577 my $self = shift;
3578
3579 return $self->_n_or_s('n', 2);
3580}
3581
3582sub _handle_s_command {
3583 my $self = shift;
3584
3585 return $self->_n_or_s('s', 1);
3586}
3587
573b5003
SF
3588sub _handle_r_command {
3589 my $self = shift;
f89bf53e 3590
573b5003 3591 # r - return from the current subroutine.
601c6a23 3592 if ($self->_is_full('r')) {
573b5003
SF
3593
3594 # Can't do anything if the program's over.
3595 next CMD if DB::_DB__is_finished();
3596
3597 # Turn on stack trace.
3598 $stack[$stack_depth] |= 1;
3599
3600 # Print return value unless the stack is empty.
3601 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3602 last CMD;
3603 }
3604
3605 return;
3606}
3607
d4038e14 3608sub _handle_T_command {
601c6a23
SF
3609 my $self = shift;
3610
3611 if ($self->_is_full('T')) {
d4038e14
SF
3612 DB::print_trace( $OUT, 1 ); # skip DB
3613 next CMD;
3614 }
3615
3616 return;
3617}
3618
b6e88520 3619sub _handle_w_command {
9875a6d2
SF
3620 my $self = shift;
3621
3622 DB::cmd_w( 'w', $self->cmd_args() );
3623 next CMD;
b6e88520
SF
3624
3625 return;
3626}
3627
25953301 3628sub _handle_W_command {
a523ec7c
SF
3629 my $self = shift;
3630
3631 if (my $arg = $self->cmd_args) {
25953301
SF
3632 DB::cmd_W( 'W', $arg );
3633 next CMD;
3634 }
3635
3636 return;
3637}
3638
14f38b27
SF
3639sub _handle_rc_recall_command {
3640 my $self = shift;
3641
3642 # $rc - recall command.
3643 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3644
3645 # No arguments, take one thing off history.
3646 pop(@hist) if length($DB::cmd) > 1;
3647
3648 # Relative (- found)?
3649 # Y - index back from most recent (by 1 if bare minus)
3650 # N - go to that particular command slot or the last
3651 # thing if nothing following.
14f38b27 3652
9c6fceaf
SF
3653 $self->cmd_verb(
3654 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3655 );
14f38b27
SF
3656
3657 # Pick out the command desired.
610f01b9 3658 $DB::cmd = $hist[$self->cmd_verb];
14f38b27
SF
3659
3660 # Print the command to be executed and restart the loop
3661 # with that command in the buffer.
3662 print {$OUT} $DB::cmd, "\n";
3663 redo CMD;
3664 }
3665
3666 return;
3667}
3668
0d2c714c
SF
3669sub _handle_rc_search_history_command {
3670 my $self = shift;
3671
3672 # $rc pattern $rc - find a command in the history.
3673 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3674
3675 # Create the pattern to use.
3676 my $pat = "^$arg";
3677 $self->pat($pat);
3678
3679 # Toss off last entry if length is >1 (and it always is).
3680 pop(@hist) if length($DB::cmd) > 1;
3681
9c6fceaf 3682 my $i;
0d2c714c
SF
3683
3684 # Look backward through the history.
3685 SEARCH_HIST:
3686 for ( $i = $#hist ; $i ; --$i ) {
3687 # Stop if we find it.
3688 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3689 }
3690
9c6fceaf 3691 if ( !$i ) {
0d2c714c
SF
3692
3693 # Never found it.
3694 print $OUT "No such command!\n\n";
3695 next CMD;
3696 }
3697
3698 # Found it. Put it in the buffer, print it, and process it.
9c6fceaf 3699 $DB::cmd = $hist[$i];
0d2c714c
SF
3700 print $OUT $DB::cmd, "\n";
3701 redo CMD;
3702 }
b6aeebb8
SF
3703
3704 return;
0d2c714c
SF
3705}
3706
0664c09a
SF
3707sub _handle_H_command {
3708 my $self = shift;
3709
3249b113 3710 if ($self->cmd_args =~ m#\A\*#) {
0664c09a
SF
3711 @hist = @truehist = ();
3712 print $OUT "History cleansed\n";
3713 next CMD;
3714 }
3715
3249b113 3716 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
0664c09a
SF
3717
3718 # Anything other than negative numbers is ignored by
3719 # the (incorrect) pattern, so this test does nothing.
3720 $end = $num ? ( $#hist - $num ) : 0;
3721
3722 # Set to the minimum if less than zero.
3723 $hist = 0 if $hist < 0;
3724
3725 # Start at the end of the array.
3726 # Stay in while we're still above the ending value.
3727 # Tick back by one each time around the loop.
3728 my $i;
3729
3730 for ( $i = $#hist ; $i > $end ; $i-- ) {
3731
3732 # Print the command unless it has no arguments.
3733 print $OUT "$i: ", $hist[$i], "\n"
3734 unless $hist[$i] =~ /^.?$/;
3735 }
3736
066