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2=head1 NAME
3
be9a9b1d 4perl5db.pl - the perl debugger
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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
25features was done using global variables, globs and the C<local()> operator
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
37debugger itself.
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
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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
49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
50temporary copy of a variable in the current scope. When the scope ends, the
51old copy is restored. This is often used in the debugger to handle the
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,
62then altered. When the subroutine returns, Perl automatically undoes the
63localization, restoring the previous value. Voila, automatic stack management.
64
65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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
69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
70track of C<$@> 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
76This is used to cleverly reverse the sense of a logical test depending on
77the value of an auxiliary variable. For instance, the debugger's C<S>
78(search for subroutines by pattern) allows you to negate the pattern
79like this:
80
81 # Find all non-'foo' subs:
82 S !/foo/
83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
88=item * 0 ^ 0 = 0
89
90(! not present and no match) --> false, don't print
91
92=item * 0 ^ 1 = 1
93
94(! not present and matches) --> true, print
95
96=item * 1 ^ 0 = 1
97
98(! present and no match) --> true, print
99
100=item * 1 ^ 1 = 0
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
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108compact a more complicated if-then-elseif-else into a more elegant
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<$frame>, have I<magical> values composed
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116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
117of state to be stored independently in a single scalar.
118
119A test like
120
121 if ($scalar & 4) ...
122
123is checking to see if the appropriate bit is on. Since each bit can be
124"addressed" independently in this way, C<$scalar> is acting sort of like
125an array of bits. Obviously, since the contents of C<$scalar> are just a
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
130all over your program whenever a bit is set, cleared, or checked. So why do
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
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140this over-optimization at the expense of readability? Possibly, but the
141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
143best balance of readability and speed, and then document how it actually
144works.
145
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146=item *
147
148Second, it's very easy to serialize a scalar number. This is done in
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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
151this trivial.
152
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153=item *
154
155Third, some of these variables are being shared with the Perl core
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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
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
165speculative - it's not exactly clear what a given variable or chunk of
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
171=head1 DATA STRUCTURES MAINTAINED BY CORE
172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob
177assignment) contains the text from C<$filename>, with each element
178corresponding to a single line of C<$filename>.
179
180The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
181assignment) contains breakpoints and actions. The keys are line numbers;
182you can set individual values, but not the whole hash. The Perl interpreter
183uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 184considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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185Values are magical in numeric context: 1 if the line is breakable, 0 if not.
186
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187The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>.
188This is also the case for evaluated strings that contain subroutines, or
189which are currently being executed. The $filename for C<eval>ed strings looks
190like C<(eval 34)> or C<(re_eval 19)>.
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191
192=head1 DEBUGGER STARTUP
193
194When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
195non-interactive sessions, C<.perldb> for interactive ones) that can set a number
196of options. In addition, this file may define a subroutine C<&afterinit>
197that will be executed (in the debugger's context) after the debugger has
198initialized itself.
199
200Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 201contents as the argument of a C<o> command in the debugger.
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202
203=head2 STARTUP-ONLY OPTIONS
204
205The following options can only be specified at startup.
206To set them in your rcfile, add a call to
207C<&parse_options("optionName=new_value")>.
208
209=over 4
210
211=item * TTY
212
213the TTY to use for debugging i/o.
214
215=item * noTTY
216
217if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 218uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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219Term::Rendezvous. Current variant is to have the name of TTY in this
220file.
221
222=item * ReadLine
223
5561b870 224if false, a dummy ReadLine is used, so you can debug
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225ReadLine applications.
226
227=item * NonStop
228
229if true, no i/o is performed until interrupt.
230
231=item * LineInfo
232
233file or pipe to print line number info to. If it is a
234pipe, a short "emacs like" message is used.
235
236=item * RemotePort
237
238host:port to connect to on remote host for remote debugging.
239
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240=item * HistFile
241
242file to store session history to. There is no default and so no
243history file is written unless this variable is explicitly set.
244
245=item * HistSize
246
247number of commands to store to the file specified in C<HistFile>.
248Default is 100.
249
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250=back
251
252=head3 SAMPLE RCFILE
253
254 &parse_options("NonStop=1 LineInfo=db.out");
255 sub afterinit { $trace = 1; }
256
257The script will run without human intervention, putting trace
258information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 259reset C<LineInfo> to something I<interactive>!)
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260
261=head1 INTERNALS DESCRIPTION
262
263=head2 DEBUGGER INTERFACE VARIABLES
264
265Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 266a C<&DB::DB();> in front of each place that can have a
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267breakpoint. At each subroutine call, it calls C<&DB::sub> with
268C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
269{require 'perl5db.pl'}> before the first line.
270
271After each C<require>d file is compiled, but before it is executed, a
272call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
273is the expanded name of the C<require>d file (as found via C<%INC>).
274
275=head3 IMPORTANT INTERNAL VARIABLES
276
277=head4 C<$CreateTTY>
278
279Used to control when the debugger will attempt to acquire another TTY to be
280used for input.
281
282=over
283
284=item * 1 - on C<fork()>
285
286=item * 2 - debugger is started inside debugger
287
288=item * 4 - on startup
289
290=back
291
292=head4 C<$doret>
293
294The value -2 indicates that no return value should be printed.
295Any other positive value causes C<DB::sub> to print return values.
296
297=head4 C<$evalarg>
298
299The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
300contents of C<@_> when C<DB::eval> is called.
301
302=head4 C<$frame>
303
304Determines what messages (if any) will get printed when a subroutine (or eval)
305is entered or exited.
306
307=over 4
308
309=item * 0 - No enter/exit messages
310
be9a9b1d 311=item * 1 - Print I<entering> messages on subroutine entry
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312
313=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
314
be9a9b1d 315=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.
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316
317=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.
318
319=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
320
321=back
322
be9a9b1d 323To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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324The debugger internally juggles the value of C<$frame> during execution to
325protect external modules that the debugger uses from getting traced.
326
327=head4 C<$level>
328
329Tracks current debugger nesting level. Used to figure out how many
330C<E<lt>E<gt>> pairs to surround the line number with when the debugger
331outputs a prompt. Also used to help determine if the program has finished
332during command parsing.
333
334=head4 C<$onetimeDump>
335
336Controls what (if anything) C<DB::eval()> will print after evaluating an
337expression.
338
339=over 4
340
341=item * C<undef> - don't print anything
342
343=item * C<dump> - use C<dumpvar.pl> to display the value returned
344
345=item * C<methods> - print the methods callable on the first item returned
346
347=back
348
349=head4 C<$onetimeDumpDepth>
350
be9a9b1d 351Controls how far down C<dumpvar.pl> will go before printing C<...> while
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352dumping a structure. Numeric. If C<undef>, print all levels.
353
354=head4 C<$signal>
355
356Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
357which is called before every statement, checks this and puts the user into
358command mode if it finds C<$signal> set to a true value.
359
360=head4 C<$single>
361
362Controls behavior during single-stepping. Stacked in C<@stack> on entry to
363each subroutine; popped again at the end of each subroutine.
364
365=over 4
366
367=item * 0 - run continuously.
368
be9a9b1d 369=item * 1 - single-step, go into subs. The C<s> command.
69893cff 370
be9a9b1d 371=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 372
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373=item * 4 - print current sub depth (turned on to force this when C<too much
374recursion> occurs.
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375
376=back
377
378=head4 C<$trace>
379
380Controls the output of trace information.
381
382=over 4
383
384=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
385
386=item * 2 - watch expressions are active
387
388=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
389
390=back
391
392=head4 C<$slave_editor>
393
3941 if C<LINEINFO> was directed to a pipe; 0 otherwise.
395
396=head4 C<@cmdfhs>
397
398Stack of filehandles that C<DB::readline()> will read commands from.
399Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
400
401=head4 C<@dbline>
402
403Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
404supplied by the Perl interpreter to the debugger. Contains the source.
405
406=head4 C<@old_watch>
407
408Previous values of watch expressions. First set when the expression is
409entered; reset whenever the watch expression changes.
410
411=head4 C<@saved>
412
413Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
414so that the debugger can substitute safe values while it's running, and
415restore them when it returns control.
416
417=head4 C<@stack>
418
419Saves the current value of C<$single> on entry to a subroutine.
420Manipulated by the C<c> command to turn off tracing in all subs above the
421current one.
422
423=head4 C<@to_watch>
424
425The 'watch' expressions: to be evaluated before each line is executed.
426
427=head4 C<@typeahead>
428
429The typeahead buffer, used by C<DB::readline>.
430
431=head4 C<%alias>
432
433Command aliases. Stored as character strings to be substituted for a command
434entered.
435
436=head4 C<%break_on_load>
437
438Keys are file names, values are 1 (break when this file is loaded) or undef
439(don't break when it is loaded).
440
441=head4 C<%dbline>
442
be9a9b1d 443Keys are line numbers, values are C<condition\0action>. If used in numeric
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444context, values are 0 if not breakable, 1 if breakable, no matter what is
445in the actual hash entry.
446
447=head4 C<%had_breakpoints>
448
449Keys are file names; values are bitfields:
450
451=over 4
452
453=item * 1 - file has a breakpoint in it.
454
455=item * 2 - file has an action in it.
456
457=back
458
459A zero or undefined value means this file has neither.
460
461=head4 C<%option>
462
463Stores the debugger options. These are character string values.
464
465=head4 C<%postponed>
466
467Saves breakpoints for code that hasn't been compiled yet.
468Keys are subroutine names, values are:
469
470=over 4
471
be9a9b1d 472=item * C<compile> - break when this sub is compiled
69893cff 473
be9a9b1d 474=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
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475
476=back
477
478=head4 C<%postponed_file>
479
480This hash keeps track of breakpoints that need to be set for files that have
481not yet been compiled. Keys are filenames; values are references to hashes.
482Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 483definitions (C<condition\0action>).
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484
485=head1 DEBUGGER INITIALIZATION
486
487The debugger's initialization actually jumps all over the place inside this
488package. This is because there are several BEGIN blocks (which of course
489execute immediately) spread through the code. Why is that?
490
491The debugger needs to be able to change some things and set some things up
492before the debugger code is compiled; most notably, the C<$deep> variable that
493C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
494debugger has to turn off warnings while the debugger code is compiled, but then
495restore them to their original setting before the program being debugged begins
496executing.
497
498The first C<BEGIN> block simply turns off warnings by saving the current
499setting of C<$^W> and then setting it to zero. The second one initializes
500the debugger variables that are needed before the debugger begins executing.
501The third one puts C<$^X> back to its former value.
502
503We'll detail the second C<BEGIN> block later; just remember that if you need
504to initialize something before the debugger starts really executing, that's
505where it has to go.
506
507=cut
508
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509package DB;
510
c7e68384 511BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 512
54d04a52 513# Debugger for Perl 5.00x; perl5db.pl patch level:
b468dcb6 514$VERSION = '1.33';
69893cff 515
e22ea7cc 516$header = "perl5db.pl version $VERSION";
d338d6fe 517
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518=head1 DEBUGGER ROUTINES
519
520=head2 C<DB::eval()>
521
522This function replaces straight C<eval()> inside the debugger; it simplifies
523the process of evaluating code in the user's context.
524
525The code to be evaluated is passed via the package global variable
526C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
527
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528Before we do the C<eval()>, we preserve the current settings of C<$trace>,
529C<$single>, C<$^D> and C<$usercontext>. The latter contains the
530preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
531user's current package, grabbed when C<DB::DB> got control. This causes the
532proper context to be used when the eval is actually done. Afterward, we
533restore C<$trace>, C<$single>, and C<$^D>.
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534
535Next we need to handle C<$@> without getting confused. We save C<$@> in a
536local lexical, localize C<$saved[0]> (which is where C<save()> will put
537C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
538C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
539considered sane by the debugger. If there was an C<eval()> error, we print
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540it on the debugger's output. If C<$onetimedump> is defined, we call
541C<dumpit> if it's set to 'dump', or C<methods> if it's set to
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542'methods'. Setting it to something else causes the debugger to do the eval
543but not print the result - handy if you want to do something else with it
544(the "watch expressions" code does this to get the value of the watch
545expression but not show it unless it matters).
546
547In any case, we then return the list of output from C<eval> to the caller,
548and unwinding restores the former version of C<$@> in C<@saved> as well
549(the localization of C<$saved[0]> goes away at the end of this scope).
550
551=head3 Parameters and variables influencing execution of DB::eval()
552
553C<DB::eval> isn't parameterized in the standard way; this is to keep the
554debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
555The variables listed below influence C<DB::eval()>'s execution directly.
556
557=over 4
558
559=item C<$evalarg> - the thing to actually be eval'ed
560
be9a9b1d 561=item C<$trace> - Current state of execution tracing
69893cff 562
be9a9b1d 563=item C<$single> - Current state of single-stepping
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564
565=item C<$onetimeDump> - what is to be displayed after the evaluation
566
567=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
568
569=back
570
571The following variables are altered by C<DB::eval()> during its execution. They
572are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
573
574=over 4
575
576=item C<@res> - used to capture output from actual C<eval>.
577
578=item C<$otrace> - saved value of C<$trace>.
579
580=item C<$osingle> - saved value of C<$single>.
581
582=item C<$od> - saved value of C<$^D>.
583
584=item C<$saved[0]> - saved value of C<$@>.
585
586=item $\ - for output of C<$@> if there is an evaluation error.
587
588=back
589
590=head3 The problem of lexicals
591
592The context of C<DB::eval()> presents us with some problems. Obviously,
593we want to be 'sandboxed' away from the debugger's internals when we do
594the eval, but we need some way to control how punctuation variables and
595debugger globals are used.
596
597We can't use local, because the code inside C<DB::eval> can see localized
598variables; and we can't use C<my> either for the same reason. The code
599in this routine compromises and uses C<my>.
600
601After this routine is over, we don't have user code executing in the debugger's
602context, so we can use C<my> freely.
603
604=cut
605
606############################################## Begin lexical danger zone
607
608# 'my' variables used here could leak into (that is, be visible in)
609# the context that the code being evaluated is executing in. This means that
610# the code could modify the debugger's variables.
611#
612# Fiddling with the debugger's context could be Bad. We insulate things as
613# much as we can.
614
c1051fcf 615sub eval {
69893cff 616
c1051fcf 617 # 'my' would make it visible from user code
e22ea7cc 618 # but so does local! --tchrist
69893cff 619 # Remember: this localizes @DB::res, not @main::res.
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620 local @res;
621 {
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622
623 # Try to keep the user code from messing with us. Save these so that
624 # even if the eval'ed code changes them, we can put them back again.
625 # Needed because the user could refer directly to the debugger's
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626 # package globals (and any 'my' variables in this containing scope)
627 # inside the eval(), and we want to try to stay safe.
e22ea7cc 628 local $otrace = $trace;
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629 local $osingle = $single;
630 local $od = $^D;
631
632 # Untaint the incoming eval() argument.
633 { ($evalarg) = $evalarg =~ /(.*)/s; }
634
e22ea7cc 635 # $usercontext built in DB::DB near the comment
69893cff
RGS
636 # "set up the context for DB::eval ..."
637 # Evaluate and save any results.
e22ea7cc 638 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
639
640 # Restore those old values.
641 $trace = $otrace;
642 $single = $osingle;
643 $^D = $od;
c1051fcf 644 }
69893cff
RGS
645
646 # Save the current value of $@, and preserve it in the debugger's copy
647 # of the saved precious globals.
c1051fcf 648 my $at = $@;
69893cff
RGS
649
650 # Since we're only saving $@, we only have to localize the array element
651 # that it will be stored in.
e22ea7cc 652 local $saved[0]; # Preserve the old value of $@
c1051fcf 653 eval { &DB::save };
69893cff
RGS
654
655 # Now see whether we need to report an error back to the user.
c1051fcf 656 if ($at) {
69893cff
RGS
657 local $\ = '';
658 print $OUT $at;
659 }
660
661 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
662 # are package globals.
663 elsif ($onetimeDump) {
e22ea7cc
RF
664 if ( $onetimeDump eq 'dump' ) {
665 local $option{dumpDepth} = $onetimedumpDepth
666 if defined $onetimedumpDepth;
667 dumpit( $OUT, \@res );
668 }
669 elsif ( $onetimeDump eq 'methods' ) {
670 methods( $res[0] );
671 }
69893cff 672 } ## end elsif ($onetimeDump)
c1051fcf 673 @res;
69893cff
RGS
674} ## end sub eval
675
676############################################## End lexical danger zone
c1051fcf 677
e22ea7cc
RF
678# After this point it is safe to introduce lexicals.
679# The code being debugged will be executing in its own context, and
69893cff 680# can't see the inside of the debugger.
d338d6fe 681#
e22ea7cc 682# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
683# possible. If you make something a lexical, it's not going to be addressable
684# from outside the debugger even if you know its name.
685
d338d6fe
PP
686# This file is automatically included if you do perl -d.
687# It's probably not useful to include this yourself.
688#
e22ea7cc 689# Before venturing further into these twisty passages, it is
2f7e9187
MS
690# wise to read the perldebguts man page or risk the ire of dragons.
691#
69893cff
RGS
692# (It should be noted that perldebguts will tell you a lot about
693# the underlying mechanics of how the debugger interfaces into the
694# Perl interpreter, but not a lot about the debugger itself. The new
695# comments in this code try to address this problem.)
696
d338d6fe 697# Note that no subroutine call is possible until &DB::sub is defined
36477c24 698# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 699# true if $deep is not defined.
055fd3a9
GS
700
701# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
702
703# modified Perl debugger, to be run from Emacs in perldb-mode
704# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
705# Johan Vromans -- upgrade to 4.0 pl 10
706# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
707
69893cff
RGS
708# (We have made efforts to clarify the comments in the change log
709# in other places; some of them may seem somewhat obscure as they
710# were originally written, and explaining them away from the code
711# in question seems conterproductive.. -JM)
712
713########################################################################
714# Changes: 0.94
715# + A lot of things changed after 0.94. First of all, core now informs
716# debugger about entry into XSUBs, overloaded operators, tied operations,
717# BEGIN and END. Handy with `O f=2'.
718# + This can make debugger a little bit too verbose, please be patient
719# and report your problems promptly.
720# + Now the option frame has 3 values: 0,1,2. XXX Document!
721# + Note that if DESTROY returns a reference to the object (or object),
722# the deletion of data may be postponed until the next function call,
723# due to the need to examine the return value.
724#
725# Changes: 0.95
726# + `v' command shows versions.
727#
e22ea7cc 728# Changes: 0.96
69893cff
RGS
729# + `v' command shows version of readline.
730# primitive completion works (dynamic variables, subs for `b' and `l',
731# options). Can `p %var'
732# + Better help (`h <' now works). New commands <<, >>, {, {{.
733# {dump|print}_trace() coded (to be able to do it from <<cmd).
734# + `c sub' documented.
735# + At last enough magic combined to stop after the end of debuggee.
736# + !! should work now (thanks to Emacs bracket matching an extra
737# `]' in a regexp is caught).
738# + `L', `D' and `A' span files now (as documented).
739# + Breakpoints in `require'd code are possible (used in `R').
740# + Some additional words on internal work of debugger.
741# + `b load filename' implemented.
742# + `b postpone subr' implemented.
743# + now only `q' exits debugger (overwritable on $inhibit_exit).
744# + When restarting debugger breakpoints/actions persist.
e22ea7cc 745# + Buglet: When restarting debugger only one breakpoint/action per
69893cff
RGS
746# autoloaded function persists.
747#
36477c24 748# Changes: 0.97: NonStop will not stop in at_exit().
69893cff
RGS
749# + Option AutoTrace implemented.
750# + Trace printed differently if frames are printed too.
751# + new `inhibitExit' option.
752# + printing of a very long statement interruptible.
1d06cb2d 753# Changes: 0.98: New command `m' for printing possible methods
69893cff
RGS
754# + 'l -' is a synonym for `-'.
755# + Cosmetic bugs in printing stack trace.
756# + `frame' & 8 to print "expanded args" in stack trace.
757# + Can list/break in imported subs.
758# + new `maxTraceLen' option.
759# + frame & 4 and frame & 8 granted.
760# + new command `m'
761# + nonstoppable lines do not have `:' near the line number.
762# + `b compile subname' implemented.
763# + Will not use $` any more.
764# + `-' behaves sane now.
477ea2b1 765# Changes: 0.99: Completion for `f', `m'.
69893cff
RGS
766# + `m' will remove duplicate names instead of duplicate functions.
767# + `b load' strips trailing whitespace.
768# completion ignores leading `|'; takes into account current package
769# when completing a subroutine name (same for `l').
055fd3a9
GS
770# Changes: 1.07: Many fixed by tchrist 13-March-2000
771# BUG FIXES:
04e43a21 772# + Added bare minimal security checks on perldb rc files, plus
055fd3a9
GS
773# comments on what else is needed.
774# + Fixed the ornaments that made "|h" completely unusable.
775# They are not used in print_help if they will hurt. Strip pod
776# if we're paging to less.
777# + Fixed mis-formatting of help messages caused by ornaments
e22ea7cc
RF
778# to restore Larry's original formatting.
779# + Fixed many other formatting errors. The code is still suboptimal,
04e43a21 780# and needs a lot of work at restructuring. It's also misindented
055fd3a9
GS
781# in many places.
782# + Fixed bug where trying to look at an option like your pager
e22ea7cc 783# shows "1".
055fd3a9
GS
784# + Fixed some $? processing. Note: if you use csh or tcsh, you will
785# lose. You should consider shell escapes not using their shell,
786# or else not caring about detailed status. This should really be
787# unified into one place, too.
788# + Fixed bug where invisible trailing whitespace on commands hoses you,
04e43a21 789# tricking Perl into thinking you weren't calling a debugger command!
055fd3a9
GS
790# + Fixed bug where leading whitespace on commands hoses you. (One
791# suggests a leading semicolon or any other irrelevant non-whitespace
792# to indicate literal Perl code.)
793# + Fixed bugs that ate warnings due to wrong selected handle.
794# + Fixed a precedence bug on signal stuff.
795# + Fixed some unseemly wording.
796# + Fixed bug in help command trying to call perl method code.
797# + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
798# ENHANCEMENTS:
799# + Added some comments. This code is still nasty spaghetti.
800# + Added message if you clear your pre/post command stacks which was
801# very easy to do if you just typed a bare >, <, or {. (A command
802# without an argument should *never* be a destructive action; this
803# API is fundamentally screwed up; likewise option setting, which
804# is equally buggered.)
805# + Added command stack dump on argument of "?" for >, <, or {.
806# + Added a semi-built-in doc viewer command that calls man with the
807# proper %Config::Config path (and thus gets caching, man -k, etc),
808# or else perldoc on obstreperous platforms.
809# + Added to and rearranged the help information.
810# + Detected apparent misuse of { ... } to declare a block; this used
811# to work but now is a command, and mysteriously gave no complaint.
04e43a21
DL
812#
813# Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
814# BUG FIX:
815# + This patch to perl5db.pl cleans up formatting issues on the help
816# summary (h h) screen in the debugger. Mostly columnar alignment
817# issues, plus converted the printed text to use all spaces, since
818# tabs don't seem to help much here.
819#
820# Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
69893cff
RGS
821# Minor bugs corrected;
822# + Support for auto-creation of new TTY window on startup, either
823# unconditionally, or if started as a kid of another debugger session;
824# + New `O'ption CreateTTY
825# I<CreateTTY> bits control attempts to create a new TTY on events:
e22ea7cc 826# 1: on fork()
69893cff
RGS
827# 2: debugger is started inside debugger
828# 4: on startup
829# + Code to auto-create a new TTY window on OS/2 (currently one
830# extra window per session - need named pipes to have more...);
831# + Simplified interface for custom createTTY functions (with a backward
832# compatibility hack); now returns the TTY name to use; return of ''
833# means that the function reset the I/O handles itself;
834# + Better message on the semantic of custom createTTY function;
835# + Convert the existing code to create a TTY into a custom createTTY
836# function;
837# + Consistent support for TTY names of the form "TTYin,TTYout";
838# + Switch line-tracing output too to the created TTY window;
839# + make `b fork' DWIM with CORE::GLOBAL::fork;
840# + High-level debugger API cmd_*():
04e43a21
DL
841# cmd_b_load($filenamepart) # b load filenamepart
842# cmd_b_line($lineno [, $cond]) # b lineno [cond]
843# cmd_b_sub($sub [, $cond]) # b sub [cond]
844# cmd_stop() # Control-C
492652be 845# cmd_d($lineno) # d lineno (B)
04e43a21
DL
846# The cmd_*() API returns FALSE on failure; in this case it outputs
847# the error message to the debugging output.
69893cff 848# + Low-level debugger API
04e43a21
DL
849# break_on_load($filename) # b load filename
850# @files = report_break_on_load() # List files with load-breakpoints
851# breakable_line_in_filename($name, $from [, $to])
852# # First breakable line in the
853# # range $from .. $to. $to defaults
e22ea7cc 854# # to $from, and may be less than
69893cff 855# # $to
04e43a21
DL
856# breakable_line($from [, $to]) # Same for the current file
857# break_on_filename_line($name, $lineno [, $cond])
e22ea7cc 858# # Set breakpoint,$cond defaults to
69893cff 859# # 1
04e43a21
DL
860# break_on_filename_line_range($name, $from, $to [, $cond])
861# # As above, on the first
862# # breakable line in range
863# break_on_line($lineno [, $cond]) # As above, in the current file
864# break_subroutine($sub [, $cond]) # break on the first breakable line
865# ($name, $from, $to) = subroutine_filename_lines($sub)
866# # The range of lines of the text
867# The low-level API returns TRUE on success, and die()s on failure.
868#
869# Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
870# BUG FIXES:
871# + Fixed warnings generated by "perl -dWe 42"
872# + Corrected spelling errors
873# + Squeezed Help (h) output into 80 columns
600d99fa
DL
874#
875# Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
876# + Made "x @INC" work like it used to
877#
878# Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
879# + Fixed warnings generated by "O" (Show debugger options)
880# + Fixed warnings generated by "p 42" (Print expression)
6f891d7d 881# Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
e22ea7cc 882# + Added windowSize option
2f7e9187
MS
883# Changes: 1.14: Oct 9, 2001 multiple
884# + Clean up after itself on VMS (Charles Lane in 12385)
885# + Adding "@ file" syntax (Peter Scott in 12014)
886# + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
887# + $^S and other debugger fixes (Ilya Zakharevich in 11120)
888# + Forgot a my() declaration (Ilya Zakharevich in 11085)
889# Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
890# + Updated 1.14 change log
891# + Added *dbline explainatory comments
892# + Mentioning perldebguts man page
492652be 893# Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
69893cff 894# + $onetimeDump improvements
492652be
RF
895# Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
896# Moved some code to cmd_[.]()'s for clarity and ease of handling,
e22ea7cc
RF
897# rationalised the following commands and added cmd_wrapper() to
898# enable switching between old and frighteningly consistent new
492652be
RF
899# behaviours for diehards: 'o CommandSet=pre580' (sigh...)
900# a(add), A(del) # action expr (added del by line)
901# + b(add), B(del) # break [line] (was b,D)
e22ea7cc 902# + w(add), W(del) # watch expr (was W,W)
69893cff 903# # added del by expr
492652be
RF
904# + h(summary), h h(long) # help (hh) (was h h,h)
905# + m(methods), M(modules) # ... (was m,v)
906# + o(option) # lc (was O)
907# + v(view code), V(view Variables) # ... (was w,V)
aef14ef9
RF
908# Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
909# + fixed missing cmd_O bug
471505cc 910# Changes: 1.19: Mar 29, 2002 Spider Boardman
911# + Added missing local()s -- DB::DB is called recursively.
35408c4e
RF
912# Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
913# + pre'n'post commands no longer trashed with no args
914# + watch val joined out of eval()
69893cff
RGS
915# Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
916# + Added comments and reformatted source. No bug fixes/enhancements.
917# + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
918# Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
919# + Flush stdout/stderr before the debugger prompt is printed.
920# Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
de5e1a3d 921# + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
e219e2fb
RF
922# Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
923# + Added command to save all debugger commands for sourcing later.
3c4b39be 924# + Added command to display parent inheritance tree of given class.
e219e2fb 925# + Fixed minor newline in history bug.
e22ea7cc
RF
926# Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
927# + Fixed option bug (setting invalid options + not recognising valid short forms)
928# Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
929# + unfork the 5.8.x and 5.9.x debuggers.
930# + whitespace and assertions call cleanup across versions
931# + H * deletes (resets) history
932# + i now handles Class + blessed objects
7fddc82f
RF
933# Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
934# + updated pod page references - clunky.
935# + removed windowid restriction for forking into an xterm.
936# + more whitespace again.
937# + wrapped restart and enabled rerun [-n] (go back n steps) command.
2cbb2ee1
RGS
938# Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
939# + Added threads support (inc. e and E commands)
6fae1ad7
RF
940# Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
941# + Added macosx_get_fork_TTY support
5561b870
AK
942# Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org>
943# + Added HistFile, HistSize
98960e6a
NC
944# Changes: 1.31
945# + Remove support for assertions and -A
946# + stop NEXT::AUTOLOAD from emitting warnings under the debugger. RT #25053
947# + "update for Mac OS X 10.5" [finding the tty device]
948# + "What I needed to get the forked debugger to work" [on VMS]
949# + [perl #57016] debugger: o warn=0 die=0 ignored
950# + Note, but don't use, PERLDBf_SAVESRC
951# + Fix #7013: lvalue subs not working inside debugger
b468dcb6
DL
952# Changes: 1.32: Jun 03, 2009 Jonathan Leto <jonathan@leto.net>
953# + Fix bug where a key _< with undefined value was put into the symbol table
954# + when the $filename variable is not set
6fae1ad7 955########################################################################
d338d6fe 956
69893cff
RGS
957=head1 DEBUGGER INITIALIZATION
958
959The debugger starts up in phases.
960
961=head2 BASIC SETUP
962
963First, it initializes the environment it wants to run in: turning off
964warnings during its own compilation, defining variables which it will need
965to avoid warnings later, setting itself up to not exit when the program
966terminates, and defaulting to printing return values for the C<r> command.
967
968=cut
969
eda6e075 970# Needed for the statement after exec():
69893cff
RGS
971#
972# This BEGIN block is simply used to switch off warnings during debugger
973# compiliation. Probably it would be better practice to fix the warnings,
974# but this is how it's done at the moment.
eda6e075 975
e22ea7cc
RF
976BEGIN {
977 $ini_warn = $^W;
978 $^W = 0;
979} # Switch compilation warnings off until another BEGIN.
d12a4851 980
69893cff
RGS
981local ($^W) = 0; # Switch run-time warnings off during init.
982
2cbb2ee1
RGS
983=head2 THREADS SUPPORT
984
985If we are running under a threaded Perl, we require threads and threads::shared
986if the environment variable C<PERL5DB_THREADED> is set, to enable proper
987threaded debugger control. C<-dt> can also be used to set this.
988
989Each new thread will be announced and the debugger prompt will always inform
990you of each new thread created. It will also indicate the thread id in which
991we are currently running within the prompt like this:
992
993 [tid] DB<$i>
994
995Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
996command prompt. The prompt will show: C<[0]> when running under threads, but
997not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
998
999While running under threads, when you set or delete a breakpoint (etc.), this
1000will apply to all threads, not just the currently running one. When you are
1001in a currently executing thread, you will stay there until it completes. With
1002the current implementation it is not currently possible to hop from one thread
1003to another.
1004
1005The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1006
1007Note that threading support was built into the debugger as of Perl version
1008C<5.8.6> and debugger version C<1.2.8>.
1009
1010=cut
1011
1012BEGIN {
1013 # ensure we can share our non-threaded variables or no-op
1014 if ($ENV{PERL5DB_THREADED}) {
1015 require threads;
1016 require threads::shared;
1017 import threads::shared qw(share);
1018 $DBGR;
1019 share(\$DBGR);
1020 lock($DBGR);
1021 print "Threads support enabled\n";
1022 } else {
1023 *lock = sub(*) {};
1024 *share = sub(*) {};
1025 }
1026}
1027
69893cff
RGS
1028# This would probably be better done with "use vars", but that wasn't around
1029# when this code was originally written. (Neither was "use strict".) And on
1030# the principle of not fiddling with something that was working, this was
1031# left alone.
1032warn( # Do not ;-)
2cbb2ee1 1033 # These variables control the execution of 'dumpvar.pl'.
69893cff
RGS
1034 $dumpvar::hashDepth,
1035 $dumpvar::arrayDepth,
1036 $dumpvar::dumpDBFiles,
1037 $dumpvar::dumpPackages,
1038 $dumpvar::quoteHighBit,
1039 $dumpvar::printUndef,
1040 $dumpvar::globPrint,
1041 $dumpvar::usageOnly,
1042
1043 # used to save @ARGV and extract any debugger-related flags.
1044 @ARGS,
1045
1046 # used to control die() reporting in diesignal()
1047 $Carp::CarpLevel,
1048
1049 # used to prevent multiple entries to diesignal()
1050 # (if for instance diesignal() itself dies)
1051 $panic,
1052
1053 # used to prevent the debugger from running nonstop
1054 # after a restart
1055 $second_time,
1056 )
1057 if 0;
d338d6fe 1058
422c59bf 1059# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 1060foreach my $k (keys (%INC)) {
bc6438f2 1061 &share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
1062};
1063
54d04a52 1064# Command-line + PERLLIB:
69893cff 1065# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
1066@ini_INC = @INC;
1067
69893cff
RGS
1068# This was an attempt to clear out the previous values of various
1069# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
1070# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1071
69893cff
RGS
1072# We set these variables to safe values. We don't want to blindly turn
1073# off warnings, because other packages may still want them.
e22ea7cc
RF
1074$trace = $signal = $single = 0; # Uninitialized warning suppression
1075 # (local $^W cannot help - other packages!).
69893cff
RGS
1076
1077# Default to not exiting when program finishes; print the return
1078# value when the 'r' command is used to return from a subroutine.
55497cff 1079$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 1080
69893cff
RGS
1081=head1 OPTION PROCESSING
1082
1083The debugger's options are actually spread out over the debugger itself and
1084C<dumpvar.pl>; some of these are variables to be set, while others are
1085subs to be called with a value. To try to make this a little easier to
1086manage, the debugger uses a few data structures to define what options
1087are legal and how they are to be processed.
1088
1089First, the C<@options> array defines the I<names> of all the options that
1090are to be accepted.
1091
1092=cut
1093
1094@options = qw(
5561b870 1095 CommandSet HistFile HistSize
e22ea7cc
RF
1096 hashDepth arrayDepth dumpDepth
1097 DumpDBFiles DumpPackages DumpReused
1098 compactDump veryCompact quote
1099 HighBit undefPrint globPrint
1100 PrintRet UsageOnly frame
1101 AutoTrace TTY noTTY
1102 ReadLine NonStop LineInfo
1103 maxTraceLen recallCommand ShellBang
1104 pager tkRunning ornaments
1105 signalLevel warnLevel dieLevel
1106 inhibit_exit ImmediateStop bareStringify
1107 CreateTTY RemotePort windowSize
584420f0 1108 DollarCaretP
e22ea7cc 1109);
d12a4851 1110
584420f0 1111@RememberOnROptions = qw(DollarCaretP);
d12a4851 1112
69893cff
RGS
1113=pod
1114
1115Second, C<optionVars> lists the variables that each option uses to save its
1116state.
1117
1118=cut
1119
1120%optionVars = (
e22ea7cc
RF
1121 hashDepth => \$dumpvar::hashDepth,
1122 arrayDepth => \$dumpvar::arrayDepth,
1123 CommandSet => \$CommandSet,
1124 DumpDBFiles => \$dumpvar::dumpDBFiles,
1125 DumpPackages => \$dumpvar::dumpPackages,
1126 DumpReused => \$dumpvar::dumpReused,
1127 HighBit => \$dumpvar::quoteHighBit,
1128 undefPrint => \$dumpvar::printUndef,
1129 globPrint => \$dumpvar::globPrint,
1130 UsageOnly => \$dumpvar::usageOnly,
1131 CreateTTY => \$CreateTTY,
1132 bareStringify => \$dumpvar::bareStringify,
1133 frame => \$frame,
1134 AutoTrace => \$trace,
1135 inhibit_exit => \$inhibit_exit,
1136 maxTraceLen => \$maxtrace,
1137 ImmediateStop => \$ImmediateStop,
1138 RemotePort => \$remoteport,
1139 windowSize => \$window,
5561b870
AK
1140 HistFile => \$histfile,
1141 HistSize => \$histsize,
69893cff
RGS
1142);
1143
1144=pod
1145
1146Third, C<%optionAction> defines the subroutine to be called to process each
1147option.
1148
1149=cut
1150
1151%optionAction = (
1152 compactDump => \&dumpvar::compactDump,
1153 veryCompact => \&dumpvar::veryCompact,
1154 quote => \&dumpvar::quote,
1155 TTY => \&TTY,
1156 noTTY => \&noTTY,
1157 ReadLine => \&ReadLine,
1158 NonStop => \&NonStop,
1159 LineInfo => \&LineInfo,
1160 recallCommand => \&recallCommand,
1161 ShellBang => \&shellBang,
1162 pager => \&pager,
1163 signalLevel => \&signalLevel,
1164 warnLevel => \&warnLevel,
1165 dieLevel => \&dieLevel,
1166 tkRunning => \&tkRunning,
1167 ornaments => \&ornaments,
1168 RemotePort => \&RemotePort,
1169 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1170);
1171
69893cff
RGS
1172=pod
1173
1174Last, the C<%optionRequire> notes modules that must be C<require>d if an
1175option is used.
1176
1177=cut
d338d6fe 1178
69893cff
RGS
1179# Note that this list is not complete: several options not listed here
1180# actually require that dumpvar.pl be loaded for them to work, but are
1181# not in the table. A subsequent patch will correct this problem; for
1182# the moment, we're just recommenting, and we are NOT going to change
1183# function.
eda6e075 1184%optionRequire = (
69893cff
RGS
1185 compactDump => 'dumpvar.pl',
1186 veryCompact => 'dumpvar.pl',
1187 quote => 'dumpvar.pl',
e22ea7cc 1188);
69893cff
RGS
1189
1190=pod
1191
1192There are a number of initialization-related variables which can be set
1193by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1194variable. These are:
1195
1196=over 4
1197
1198=item C<$rl> - readline control XXX needs more explanation
1199
1200=item C<$warnLevel> - whether or not debugger takes over warning handling
1201
1202=item C<$dieLevel> - whether or not debugger takes over die handling
1203
1204=item C<$signalLevel> - whether or not debugger takes over signal handling
1205
1206=item C<$pre> - preprompt actions (array reference)
1207
1208=item C<$post> - postprompt actions (array reference)
1209
1210=item C<$pretype>
1211
1212=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1213
1214=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1215
1216=back
1217
1218=cut
d338d6fe
PP
1219
1220# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1221$rl = 1 unless defined $rl;
1222$warnLevel = 1 unless defined $warnLevel;
1223$dieLevel = 1 unless defined $dieLevel;
1224$signalLevel = 1 unless defined $signalLevel;
1225$pre = [] unless defined $pre;
1226$post = [] unless defined $post;
1227$pretype = [] unless defined $pretype;
1228$CreateTTY = 3 unless defined $CreateTTY;
1229$CommandSet = '580' unless defined $CommandSet;
1230
2cbb2ee1
RGS
1231share($rl);
1232share($warnLevel);
1233share($dieLevel);
1234share($signalLevel);
1235share($pre);
1236share($post);
1237share($pretype);
1238share($rl);
1239share($CreateTTY);
1240share($CommandSet);
1241
69893cff
RGS
1242=pod
1243
1244The default C<die>, C<warn>, and C<signal> handlers are set up.
1245
1246=cut
055fd3a9 1247
d338d6fe
PP
1248warnLevel($warnLevel);
1249dieLevel($dieLevel);
1250signalLevel($signalLevel);
055fd3a9 1251
69893cff
RGS
1252=pod
1253
1254The pager to be used is needed next. We try to get it from the
5561b870 1255environment first. If it's not defined there, we try to find it in
69893cff
RGS
1256the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1257then call the C<pager()> function to save the pager name.
1258
1259=cut
1260
1261# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1262pager(
e22ea7cc 1263
69893cff 1264 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1265 defined $ENV{PAGER}
1266 ? $ENV{PAGER}
69893cff
RGS
1267
1268 # If not, see if Config.pm defines it.
e22ea7cc
RF
1269 : eval { require Config }
1270 && defined $Config::Config{pager}
1271 ? $Config::Config{pager}
69893cff
RGS
1272
1273 # If not, fall back to 'more'.
e22ea7cc
RF
1274 : 'more'
1275 )
1276 unless defined $pager;
69893cff
RGS
1277
1278=pod
1279
1280We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1281recall character (C<!> unless otherwise defined) and the shell escape
1282character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1283neither works in the debugger at the moment.
1284
1285=cut
1286
055fd3a9 1287setman();
69893cff
RGS
1288
1289# Set up defaults for command recall and shell escape (note:
1290# these currently don't work in linemode debugging).
d338d6fe 1291&recallCommand("!") unless defined $prc;
69893cff
RGS
1292&shellBang("!") unless defined $psh;
1293
1294=pod
1295
1296We then set up the gigantic string containing the debugger help.
1297We also set the limit on the number of arguments we'll display during a
1298trace.
1299
1300=cut
1301
04e43a21 1302sethelp();
69893cff
RGS
1303
1304# If we didn't get a default for the length of eval/stack trace args,
1305# set it here.
1d06cb2d 1306$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1307
1308=head2 SETTING UP THE DEBUGGER GREETING
1309
be9a9b1d 1310The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1311running, and whether the current debugger is the primary or a child.
1312
1313If we are the primary, we just hang onto our pid so we'll have it when
1314or if we start a child debugger. If we are a child, we'll set things up
1315so we'll have a unique greeting and so the parent will give us our own
1316TTY later.
1317
1318We save the current contents of the C<PERLDB_PIDS> environment variable
1319because we mess around with it. We'll also need to hang onto it because
1320we'll need it if we restart.
1321
1322Child debuggers make a label out of the current PID structure recorded in
1323PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1324yet so the parent will give them one later via C<resetterm()>.
1325
1326=cut
1327
e22ea7cc 1328# Save the current contents of the environment; we're about to
69893cff 1329# much with it. We'll need this if we have to restart.
f1583d8f 1330$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1331
e22ea7cc
RF
1332if ( defined $ENV{PERLDB_PIDS} ) {
1333
69893cff 1334 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1335 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1336 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1337
1338 my $env_pids = $ENV{PERLDB_PIDS};
1339 $pids = "[$env_pids]";
1340
1341 # Unless we are on OpenVMS, all programs under the DCL shell run under
1342 # the same PID.
1343
1344 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1345 $term_pid = $$;
1346 }
1347 else {
1348 $ENV{PERLDB_PIDS} .= "->$$";
1349 $term_pid = -1;
1350 }
1351
69893cff
RGS
1352} ## end if (defined $ENV{PERLDB_PIDS...
1353else {
e22ea7cc
RF
1354
1355 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1356 # child debugger, and mark us as the parent, so we'll know to set up
1357 # more TTY's is we have to.
1358 $ENV{PERLDB_PIDS} = "$$";
619a0444 1359 $pids = "[pid=$$]";
e22ea7cc 1360 $term_pid = $$;
f1583d8f 1361}
69893cff 1362
f1583d8f 1363$pidprompt = '';
69893cff
RGS
1364
1365# Sets up $emacs as a synonym for $slave_editor.
1366*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1367
1368=head2 READING THE RC FILE
1369
1370The debugger will read a file of initialization options if supplied. If
1371running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1372
1373=cut
1374
1375# As noted, this test really doesn't check accurately that the debugger
1376# is running at a terminal or not.
d338d6fe 1377
98274836
JM
1378my $dev_tty = '/dev/tty';
1379 $dev_tty = 'TT:' if ($^O eq 'VMS');
1380if ( -e $dev_tty ) { # this is the wrong metric!
e22ea7cc
RF
1381 $rcfile = ".perldb";
1382}
69893cff
RGS
1383else {
1384 $rcfile = "perldb.ini";
d338d6fe
PP
1385}
1386
69893cff
RGS
1387=pod
1388
1389The debugger does a safety test of the file to be read. It must be owned
1390either by the current user or root, and must only be writable by the owner.
1391
1392=cut
1393
1394# This wraps a safety test around "do" to read and evaluate the init file.
1395#
055fd3a9
GS
1396# This isn't really safe, because there's a race
1397# between checking and opening. The solution is to
1398# open and fstat the handle, but then you have to read and
1399# eval the contents. But then the silly thing gets
69893cff
RGS
1400# your lexical scope, which is unfortunate at best.
1401sub safe_do {
055fd3a9
GS
1402 my $file = shift;
1403
1404 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1405 local $SIG{__WARN__};
1406 local $SIG{__DIE__};
055fd3a9 1407
e22ea7cc 1408 unless ( is_safe_file($file) ) {
69893cff 1409 CORE::warn <<EO_GRIPE;
055fd3a9
GS
1410perldb: Must not source insecure rcfile $file.
1411 You or the superuser must be the owner, and it must not
69893cff 1412 be writable by anyone but its owner.
055fd3a9 1413EO_GRIPE
69893cff
RGS
1414 return;
1415 } ## end unless (is_safe_file($file...
055fd3a9
GS
1416
1417 do $file;
1418 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1419} ## end sub safe_do
055fd3a9 1420
69893cff
RGS
1421# This is the safety test itself.
1422#
055fd3a9
GS
1423# Verifies that owner is either real user or superuser and that no
1424# one but owner may write to it. This function is of limited use
1425# when called on a path instead of upon a handle, because there are
1426# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1427# eventually accessed is the same as the one tested.
055fd3a9
GS
1428# Assumes that the file's existence is not in doubt.
1429sub is_safe_file {
1430 my $path = shift;
69893cff 1431 stat($path) || return; # mysteriously vaporized
e22ea7cc 1432 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1433
1434 return 0 if $uid != 0 && $uid != $<;
1435 return 0 if $mode & 022;
1436 return 1;
69893cff 1437} ## end sub is_safe_file
055fd3a9 1438
69893cff 1439# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1440# exists, we safely do it.
1441if ( -f $rcfile ) {
055fd3a9 1442 safe_do("./$rcfile");
69893cff 1443}
e22ea7cc 1444
69893cff 1445# If there isn't one here, try the user's home directory.
e22ea7cc 1446elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1447 safe_do("$ENV{HOME}/$rcfile");
1448}
e22ea7cc 1449
69893cff 1450# Else try the login directory.
e22ea7cc 1451elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1452 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1453}
1454
69893cff 1455# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1456if ( defined $ENV{PERLDB_OPTS} ) {
1457 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1458}
1459
69893cff
RGS
1460=pod
1461
1462The last thing we do during initialization is determine which subroutine is
1463to be used to obtain a new terminal when a new debugger is started. Right now,
6fae1ad7 1464the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
69893cff
RGS
1465
1466=cut
1467
1468# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1469# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1470# OS/2, or on Mac OS X. This may need some expansion.
1471
1472if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1473{
6fae1ad7
RF
1474 if (defined $ENV{TERM} # If we know what kind
1475 # of terminal this is,
1476 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1477 and defined $ENV{DISPLAY} # and what display it's on,
1478 )
1479 {
1480 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1481 }
1482 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1483 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1484 }
1485 elsif ( $^O eq 'darwin' # If this is Mac OS X
1486 and defined $ENV{TERM_PROGRAM} # and we're running inside
1487 and $ENV{TERM_PROGRAM}
1488 eq 'Apple_Terminal' # Terminal.app
1489 )
1490 {
1491 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1492 }
69893cff 1493} ## end if (not defined &get_fork_TTY...
e22ea7cc 1494
dbb46cec
DQ
1495# untaint $^O, which may have been tainted by the last statement.
1496# see bug [perl #24674]
e22ea7cc
RF
1497$^O =~ m/^(.*)\z/;
1498$^O = $1;
f1583d8f 1499
d12a4851 1500# Here begin the unreadable code. It needs fixing.
055fd3a9 1501
69893cff
RGS
1502=head2 RESTART PROCESSING
1503
1504This section handles the restart command. When the C<R> command is invoked, it
1505tries to capture all of the state it can into environment variables, and
1506then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1507if C<PERLDB_RESTART> is there; if so, we reload all the information that
1508the R command stuffed into the environment variables.
1509
1510 PERLDB_RESTART - flag only, contains no restart data itself.
1511 PERLDB_HIST - command history, if it's available
1512 PERLDB_ON_LOAD - breakpoints set by the rc file
1513 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1514 PERLDB_VISITED - files that had breakpoints
1515 PERLDB_FILE_... - breakpoints for a file
1516 PERLDB_OPT - active options
1517 PERLDB_INC - the original @INC
1518 PERLDB_PRETYPE - preprompt debugger actions
1519 PERLDB_PRE - preprompt Perl code
1520 PERLDB_POST - post-prompt Perl code
1521 PERLDB_TYPEAHEAD - typeahead captured by readline()
1522
1523We chug through all these variables and plug the values saved in them
1524back into the appropriate spots in the debugger.
1525
1526=cut
1527
e22ea7cc
RF
1528if ( exists $ENV{PERLDB_RESTART} ) {
1529
69893cff 1530 # We're restarting, so we don't need the flag that says to restart anymore.
e22ea7cc
RF
1531 delete $ENV{PERLDB_RESTART};
1532
1533 # $restart = 1;
1534 @hist = get_list('PERLDB_HIST');
1535 %break_on_load = get_list("PERLDB_ON_LOAD");
1536 %postponed = get_list("PERLDB_POSTPONE");
69893cff 1537
2cbb2ee1
RGS
1538 share(@hist);
1539 share(@truehist);
1540 share(%break_on_load);
1541 share(%postponed);
1542
69893cff 1543 # restore breakpoints/actions
e22ea7cc
RF
1544 my @had_breakpoints = get_list("PERLDB_VISITED");
1545 for ( 0 .. $#had_breakpoints ) {
1546 my %pf = get_list("PERLDB_FILE_$_");
1547 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1548 }
69893cff
RGS
1549
1550 # restore options
e22ea7cc
RF
1551 my %opt = get_list("PERLDB_OPT");
1552 my ( $opt, $val );
1553 while ( ( $opt, $val ) = each %opt ) {
1554 $val =~ s/[\\\']/\\$1/g;
1555 parse_options("$opt'$val'");
1556 }
69893cff
RGS
1557
1558 # restore original @INC
e22ea7cc
RF
1559 @INC = get_list("PERLDB_INC");
1560 @ini_INC = @INC;
1561
1562 # return pre/postprompt actions and typeahead buffer
1563 $pretype = [ get_list("PERLDB_PRETYPE") ];
1564 $pre = [ get_list("PERLDB_PRE") ];
1565 $post = [ get_list("PERLDB_POST") ];
1566 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1567} ## end if (exists $ENV{PERLDB_RESTART...
1568
1569=head2 SETTING UP THE TERMINAL
1570
1571Now, we'll decide how the debugger is going to interact with the user.
1572If there's no TTY, we set the debugger to run non-stop; there's not going
1573to be anyone there to enter commands.
1574
1575=cut
54d04a52 1576
d338d6fe 1577if ($notty) {
69893cff 1578 $runnonstop = 1;
2cbb2ee1 1579 share($runnonstop);
69893cff 1580}
d12a4851 1581
69893cff
RGS
1582=pod
1583
1584If there is a TTY, we have to determine who it belongs to before we can
1585proceed. If this is a slave editor or graphical debugger (denoted by
1586the first command-line switch being '-emacs'), we shift this off and
1587set C<$rl> to 0 (XXX ostensibly to do straight reads).
1588
1589=cut
1590
1591else {
e22ea7cc 1592
69893cff
RGS
1593 # Is Perl being run from a slave editor or graphical debugger?
1594 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1595 $slave_editor =
1596 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1597 $rl = 0, shift(@main::ARGV) if $slave_editor;
1598
1599 #require Term::ReadLine;
d12a4851 1600
69893cff
RGS
1601=pod
1602
1603We then determine what the console should be on various systems:
1604
1605=over 4
1606
1607=item * Cygwin - We use C<stdin> instead of a separate device.
1608
1609=cut
1610
e22ea7cc
RF
1611 if ( $^O eq 'cygwin' ) {
1612
69893cff
RGS
1613 # /dev/tty is binary. use stdin for textmode
1614 undef $console;
1615 }
1616
1617=item * Unix - use C</dev/tty>.
1618
1619=cut
1620
e22ea7cc 1621 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1622 $console = "/dev/tty";
1623 }
1624
1625=item * Windows or MSDOS - use C<con>.
1626
1627=cut
1628
e22ea7cc 1629 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1630 $console = "con";
1631 }
1632
69893cff
RGS
1633=item * VMS - use C<sys$command>.
1634
1635=cut
1636
1637 else {
e22ea7cc 1638
69893cff
RGS
1639 # everything else is ...
1640 $console = "sys\$command";
d12a4851 1641 }
69893cff
RGS
1642
1643=pod
1644
1645=back
1646
1647Several other systems don't use a specific console. We C<undef $console>
1648for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1649with a slave editor, Epoc).
1650
1651=cut
d12a4851 1652
e22ea7cc
RF
1653 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1654
69893cff 1655 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1656 $console = undef;
1657 }
1658
1659 if ( $^O eq 'NetWare' ) {
d12a4851 1660
69893cff
RGS
1661 # /dev/tty is binary. use stdin for textmode
1662 $console = undef;
1663 }
d12a4851 1664
69893cff
RGS
1665 # In OS/2, we need to use STDIN to get textmode too, even though
1666 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1667 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1668 { # In OS/2
1669 $console = undef;
1670 }
1671
1672 # EPOC also falls into the 'got to use STDIN' camp.
1673 if ( $^O eq 'epoc' ) {
1674 $console = undef;
1675 }
d12a4851 1676
69893cff
RGS
1677=pod
1678
1679If there is a TTY hanging around from a parent, we use that as the console.
1680
1681=cut
1682
e22ea7cc 1683 $console = $tty if defined $tty;
d12a4851 1684
69893cff
RGS
1685=head2 SOCKET HANDLING
1686
1687The debugger is capable of opening a socket and carrying out a debugging
1688session over the socket.
1689
1690If C<RemotePort> was defined in the options, the debugger assumes that it
1691should try to start a debugging session on that port. It builds the socket
1692and then tries to connect the input and output filehandles to it.
1693
1694=cut
1695
1696 # Handle socket stuff.
e22ea7cc
RF
1697
1698 if ( defined $remoteport ) {
1699
69893cff
RGS
1700 # If RemotePort was defined in the options, connect input and output
1701 # to the socket.
e22ea7cc
RF
1702 require IO::Socket;
1703 $OUT = new IO::Socket::INET(
1704 Timeout => '10',
1705 PeerAddr => $remoteport,
1706 Proto => 'tcp',
69893cff 1707 );
e22ea7cc
RF
1708 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1709 $IN = $OUT;
69893cff
RGS
1710 } ## end if (defined $remoteport)
1711
1712=pod
1713
1714If no C<RemotePort> was defined, and we want to create a TTY on startup,
1715this is probably a situation where multiple debuggers are running (for example,
1716a backticked command that starts up another debugger). We create a new IN and
1717OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1718and if we can.
1719
1720=cut
1721
1722 # Non-socket.
1723 else {
e22ea7cc 1724
69893cff
RGS
1725 # Two debuggers running (probably a system or a backtick that invokes
1726 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1727 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1728 # know how, and we can.
e22ea7cc
RF
1729 create_IN_OUT(4) if $CreateTTY & 4;
1730 if ($console) {
1731
69893cff 1732 # If we have a console, check to see if there are separate ins and
cd1191f1 1733 # outs to open. (They are assumed identical if not.)
69893cff 1734
e22ea7cc
RF
1735 my ( $i, $o ) = split /,/, $console;
1736 $o = $i unless defined $o;
69893cff 1737
69893cff 1738 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1739 open( IN, "+<$i" )
1740 || open( IN, "<$i" )
1741 || open( IN, "<&STDIN" );
1742
69893cff
RGS
1743 # read/write/create/clobber out, or write/create/clobber out,
1744 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1745 open( OUT, "+>$o" )
1746 || open( OUT, ">$o" )
1747 || open( OUT, ">&STDERR" )
1748 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1749
1750 } ## end if ($console)
1751 elsif ( not defined $console ) {
1752
1753 # No console. Open STDIN.
1754 open( IN, "<&STDIN" );
1755
1756 # merge with STDERR, or with STDOUT.
1757 open( OUT, ">&STDERR" )
1758 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1759 $console = 'STDIN/OUT';
69893cff
RGS
1760 } ## end elsif (not defined $console)
1761
1762 # Keep copies of the filehandles so that when the pager runs, it
1763 # can close standard input without clobbering ours.
e22ea7cc
RF
1764 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1765 } ## end elsif (from if(defined $remoteport))
1766
1767 # Unbuffer DB::OUT. We need to see responses right away.
1768 my $previous = select($OUT);
1769 $| = 1; # for DB::OUT
1770 select($previous);
1771
1772 # Line info goes to debugger output unless pointed elsewhere.
1773 # Pointing elsewhere makes it possible for slave editors to
1774 # keep track of file and position. We have both a filehandle
1775 # and a I/O description to keep track of.
1776 $LINEINFO = $OUT unless defined $LINEINFO;
1777 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1
RGS
1778 # share($LINEINFO); # <- unable to share globs
1779 share($lineinfo); #
e22ea7cc 1780
69893cff
RGS
1781=pod
1782
1783To finish initialization, we show the debugger greeting,
1784and then call the C<afterinit()> subroutine if there is one.
1785
1786=cut
d12a4851 1787
e22ea7cc
RF
1788 # Show the debugger greeting.
1789 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1790 unless ($runnonstop) {
1791 local $\ = '';
1792 local $, = '';
1793 if ( $term_pid eq '-1' ) {
1794 print $OUT "\nDaughter DB session started...\n";
1795 }
1796 else {
1797 print $OUT "\nLoading DB routines from $header\n";
1798 print $OUT (
1799 "Editor support ",
1800 $slave_editor ? "enabled" : "available", ".\n"
1801 );
1802 print $OUT
69893cff
RGS
1803"\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1804 } ## end else [ if ($term_pid eq '-1')
1805 } ## end unless ($runnonstop)
1806} ## end else [ if ($notty)
1807
1808# XXX This looks like a bug to me.
1809# Why copy to @ARGS and then futz with @args?
d338d6fe
PP
1810@ARGS = @ARGV;
1811for (@args) {
69893cff
RGS
1812 # Make sure backslashes before single quotes are stripped out, and
1813 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1814 # s/\'/\\\'/g; # removed while not justified understandably
1815 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
d338d6fe
PP
1816}
1817
e22ea7cc 1818# If there was an afterinit() sub defined, call it. It will get
69893cff 1819# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1820if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1821 &afterinit();
d338d6fe 1822}
e22ea7cc 1823
69893cff 1824# Inform us about "Stack dump during die enabled ..." in dieLevel().
43aed9ee
IZ
1825$I_m_init = 1;
1826
d338d6fe
PP
1827############################################################ Subroutines
1828
69893cff
RGS
1829=head1 SUBROUTINES
1830
1831=head2 DB
1832
1833This gigantic subroutine is the heart of the debugger. Called before every
1834statement, its job is to determine if a breakpoint has been reached, and
1835stop if so; read commands from the user, parse them, and execute
b468dcb6 1836them, and then send execution off to the next statement.
69893cff
RGS
1837
1838Note that the order in which the commands are processed is very important;
1839some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1840to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1841but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1842see what's happening in any given command.
1843
1844=cut
1845
d338d6fe 1846sub DB {
69893cff 1847
2cbb2ee1
RGS
1848 # lock the debugger and get the thread id for the prompt
1849 lock($DBGR);
1850 my $tid;
1851 if ($ENV{PERL5DB_THREADED}) {
878090d5 1852 $tid = eval { "[".threads->tid."]" };
2cbb2ee1
RGS
1853 }
1854
69893cff 1855 # Check for whether we should be running continuously or not.
36477c24 1856 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1857 if ( $single and not $second_time++ ) {
1858
69893cff 1859 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1860 if ($runnonstop) { # Disable until signal
1861 # If there's any call stack in place, turn off single
1862 # stepping into subs throughout the stack.
1863 for ( $i = 0 ; $i <= $stack_depth ; ) {
1864 $stack[ $i++ ] &= ~1;
1865 }
1866
69893cff 1867 # And we are now no longer in single-step mode.
e22ea7cc 1868 $single = 0;
69893cff
RGS
1869
1870 # If we simply returned at this point, we wouldn't get
1871 # the trace info. Fall on through.
e22ea7cc 1872 # return;
69893cff
RGS
1873 } ## end if ($runnonstop)
1874
e22ea7cc
RF
1875 elsif ($ImmediateStop) {
1876
1877 # We are supposed to stop here; XXX probably a break.
1878 $ImmediateStop = 0; # We've processed it; turn it off
1879 $signal = 1; # Simulate an interrupt to force
1880 # us into the command loop
69893cff
RGS
1881 }
1882 } ## end if ($single and not $second_time...
1883
1884 # If we're in single-step mode, or an interrupt (real or fake)
1885 # has occurred, turn off non-stop mode.
1886 $runnonstop = 0 if $single or $signal;
1887
1888 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1889 # The code being debugged may have altered them.
d338d6fe 1890 &save;
69893cff
RGS
1891
1892 # Since DB::DB gets called after every line, we can use caller() to
1893 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1894 # caller is returning all the extra information when called from the
69893cff 1895 # debugger.
e22ea7cc 1896 local ( $package, $filename, $line ) = caller;
471505cc 1897 local $filename_ini = $filename;
69893cff
RGS
1898
1899 # set up the context for DB::eval, so it can properly execute
1900 # code on behalf of the user. We add the package in so that the
1901 # code is eval'ed in the proper package (not in the debugger!).
1902 local $usercontext =
e22ea7cc 1903 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
69893cff
RGS
1904
1905 # Create an alias to the active file magical array to simplify
1906 # the code here.
e22ea7cc 1907 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1908
69893cff 1909 # Last line in the program.
471505cc 1910 local $max = $#dbline;
69893cff
RGS
1911
1912 # if we have something here, see if we should break.
e22ea7cc
RF
1913 if ( $dbline{$line}
1914 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1915 {
1916
69893cff 1917 # Stop if the stop criterion says to just stop.
e22ea7cc 1918 if ( $stop eq '1' ) {
69893cff
RGS
1919 $signal |= 1;
1920 }
e22ea7cc 1921
69893cff
RGS
1922 # It's a conditional stop; eval it in the user's context and
1923 # see if we should stop. If so, remove the one-time sigil.
1924 elsif ($stop) {
e22ea7cc 1925 $evalarg = "\$DB::signal |= 1 if do {$stop}";
69893cff
RGS
1926 &eval;
1927 $dbline{$line} =~ s/;9($|\0)/$1/;
1928 }
1929 } ## end if ($dbline{$line} && ...
1930
1931 # Preserve the current stop-or-not, and see if any of the W
1932 # (watch expressions) has changed.
36477c24 1933 my $was_signal = $signal;
69893cff
RGS
1934
1935 # If we have any watch expressions ...
e22ea7cc
RF
1936 if ( $trace & 2 ) {
1937 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1938 $evalarg = $to_watch[$n];
1939 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1940
1941 # Fix context DB::eval() wants to return an array, but
1942 # we need a scalar here.
e22ea7cc
RF
1943 my ($val) = join( "', '", &eval );
1944 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1945
1946 # Did it change?
e22ea7cc
RF
1947 if ( $val ne $old_watch[$n] ) {
1948
69893cff 1949 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1950 $signal = 1;
1951 print $OUT <<EOP;
405ff068 1952Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1953 old value:\t$old_watch[$n]
1954 new value:\t$val
6027b9a3 1955EOP
e22ea7cc 1956 $old_watch[$n] = $val;
69893cff
RGS
1957 } ## end if ($val ne $old_watch...
1958 } ## end for (my $n = 0 ; $n <= ...
1959 } ## end if ($trace & 2)
1960
1961=head2 C<watchfunction()>
1962
1963C<watchfunction()> is a function that can be defined by the user; it is a
1964function which will be run on each entry to C<DB::DB>; it gets the
1965current package, filename, and line as its parameters.
1966
1967The watchfunction can do anything it likes; it is executing in the
1968debugger's context, so it has access to all of the debugger's internal
1969data structures and functions.
1970
1971C<watchfunction()> can control the debugger's actions. Any of the following
1972will cause the debugger to return control to the user's program after
1973C<watchfunction()> executes:
1974
1975=over 4
1976
be9a9b1d
AT
1977=item *
1978
1979Returning a false value from the C<watchfunction()> itself.
1980
1981=item *
1982
1983Altering C<$single> to a false value.
1984
1985=item *
69893cff 1986
be9a9b1d 1987Altering C<$signal> to a false value.
69893cff 1988
be9a9b1d 1989=item *
69893cff 1990
be9a9b1d 1991Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1992check for C<watchfunction()>. This can be done with
1993
1994 $trace &= ~4;
1995
1996=back
1997
1998=cut
1999
e22ea7cc 2000 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2001 # current package, filename, and line. The function executes in
2002 # the DB:: package.
e22ea7cc
RF
2003 if ( $trace & 4 ) { # User-installed watch
2004 return
2005 if watchfunction( $package, $filename, $line )
2006 and not $single
2007 and not $was_signal
2008 and not( $trace & ~4 );
69893cff
RGS
2009 } ## end if ($trace & 4)
2010
e22ea7cc 2011 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2012 # turn off the signal now.
6027b9a3 2013 $was_signal = $signal;
69893cff
RGS
2014 $signal = 0;
2015
2016=head2 GETTING READY TO EXECUTE COMMANDS
2017
2018The debugger decides to take control if single-step mode is on, the
2019C<t> command was entered, or the user generated a signal. If the program
2020has fallen off the end, we set things up so that entering further commands
2021won't cause trouble, and we say that the program is over.
2022
2023=cut
2024
2025 # Check to see if we should grab control ($single true,
2026 # trace set appropriately, or we got a signal).
e22ea7cc
RF
2027 if ( $single || ( $trace & 1 ) || $was_signal ) {
2028
69893cff 2029 # Yes, grab control.
e22ea7cc
RF
2030 if ($slave_editor) {
2031
69893cff 2032 # Tell the editor to update its position.
e22ea7cc
RF
2033 $position = "\032\032$filename:$line:0\n";
2034 print_lineinfo($position);
2035 }
69893cff
RGS
2036
2037=pod
2038
2039Special check: if we're in package C<DB::fake>, we've gone through the
2040C<END> block at least once. We set up everything so that we can continue
2041to enter commands and have a valid context to be in.
2042
2043=cut
2044
e22ea7cc 2045 elsif ( $package eq 'DB::fake' ) {
69893cff 2046
69893cff 2047 # Fallen off the end already.
e22ea7cc
RF
2048 $term || &setterm;
2049 print_help(<<EOP);
405ff068 2050Debugged program terminated. Use B<q> to quit or B<R> to restart,
6b27b0a0
BD
2051 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2052 B<h q>, B<h R> or B<h o> to get additional info.
405ff068 2053EOP
e22ea7cc 2054
69893cff 2055 # Set the DB::eval context appropriately.
e22ea7cc
RF
2056 $package = 'main';
2057 $usercontext =
2058 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2059 . "package $package;"; # this won't let them modify, alas
69893cff 2060 } ## end elsif ($package eq 'DB::fake')
e219e2fb 2061
69893cff 2062=pod
e219e2fb 2063
69893cff
RGS
2064If the program hasn't finished executing, we scan forward to the
2065next executable line, print that out, build the prompt from the file and line
2066number information, and print that.
e219e2fb 2067
69893cff
RGS
2068=cut
2069
e22ea7cc
RF
2070 else {
2071
69893cff
RGS
2072 # Still somewhere in the midst of execution. Set up the
2073 # debugger prompt.
2074 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 2075 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
2076 #module names)
2077
e22ea7cc
RF
2078 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2079 $prefix .= "$sub($filename:";
2080 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2081
2082 # Break up the prompt if it's really long.
e22ea7cc
RF
2083 if ( length($prefix) > 30 ) {
2084 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2085 $prefix = "";
2086 $infix = ":\t";
2087 }
2088 else {
2089 $infix = "):\t";
2090 $position = "$prefix$line$infix$dbline[$line]$after";
2091 }
69893cff
RGS
2092
2093 # Print current line info, indenting if necessary.
e22ea7cc
RF
2094 if ($frame) {
2095 print_lineinfo( ' ' x $stack_depth,
2096 "$line:\t$dbline[$line]$after" );
2097 }
2098 else {
2099 print_lineinfo($position);
2100 }
69893cff
RGS
2101
2102 # Scan forward, stopping at either the end or the next
2103 # unbreakable line.
e22ea7cc
RF
2104 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2105 { #{ vi
69893cff
RGS
2106
2107 # Drop out on null statements, block closers, and comments.
2108 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2109
2110 # Drop out if the user interrupted us.
2111 last if $signal;
2112
2113 # Append a newline if the line doesn't have one. Can happen
2114 # in eval'ed text, for instance.
e22ea7cc 2115 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2116
2117 # Next executable line.
2118 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2119 $position .= $incr_pos;
2120 if ($frame) {
e22ea7cc 2121
69893cff 2122 # Print it indented if tracing is on.
e22ea7cc
RF
2123 print_lineinfo( ' ' x $stack_depth,
2124 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2125 }
2126 else {
2127 print_lineinfo($incr_pos);
2128 }
2129 } ## end for ($i = $line + 1 ; $i...
2130 } ## end else [ if ($slave_editor)
2131 } ## end if ($single || ($trace...
2132
2133=pod
2134
2135If there's an action to be executed for the line we stopped at, execute it.
2136If there are any preprompt actions, execute those as well.
e219e2fb
RF
2137
2138=cut
2139
69893cff
RGS
2140 # If there's an action, do it now.
2141 $evalarg = $action, &eval if $action;
e219e2fb 2142
69893cff
RGS
2143 # Are we nested another level (e.g., did we evaluate a function
2144 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2145 if ( $single || $was_signal ) {
2146
69893cff 2147 # Yes, go down a level.
e22ea7cc 2148 local $level = $level + 1;
69893cff
RGS
2149
2150 # Do any pre-prompt actions.
e22ea7cc
RF
2151 foreach $evalarg (@$pre) {
2152 &eval;
2153 }
69893cff
RGS
2154
2155 # Complain about too much recursion if we passed the limit.
e22ea7cc 2156 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2157 if $single & 4;
2158
2159 # The line we're currently on. Set $incr to -1 to stay here
2160 # until we get a command that tells us to advance.
e22ea7cc
RF
2161 $start = $line;
2162 $incr = -1; # for backward motion.
69893cff
RGS
2163
2164 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2165 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2166
2167=head2 WHERE ARE WE?
2168
2169XXX Relocate this section?
2170
2171The debugger normally shows the line corresponding to the current line of
2172execution. Sometimes, though, we want to see the next line, or to move elsewhere
2173in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2174
be9a9b1d
AT
2175C<$incr> controls by how many lines the I<current> line should move forward
2176after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2177line shouldn't change.
2178
be9a9b1d 2179C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2180move forwards or backwards from when doing an C<L> or C<-> command.
2181
2182C<$max> tells the debugger where the last line of the current file is. It's
2183used to terminate loops most often.
2184
2185=head2 THE COMMAND LOOP
2186
2187Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2188in two parts:
2189
2190=over 4
2191
be9a9b1d
AT
2192=item *
2193
2194The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2195reads a command and then executes it.
2196
be9a9b1d
AT
2197=item *
2198
2199The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2200is wholly contained inside the C<CMD> block and only executes a command.
2201Used to handle commands running inside a pager.
2202
2203=back
2204
2205So why have two labels to restart the loop? Because sometimes, it's easier to
2206have a command I<generate> another command and then re-execute the loop to do
2207the new command. This is faster, but perhaps a bit more convoluted.
2208
2209=cut
2210
2211 # The big command dispatch loop. It keeps running until the
2212 # user yields up control again.
2213 #
2214 # If we have a terminal for input, and we get something back
2215 # from readline(), keep on processing.
e22ea7cc
RF
2216 CMD:
2217 while (
2218
69893cff 2219 # We have a terminal, or can get one ...
e22ea7cc
RF
2220 ( $term || &setterm ),
2221
69893cff 2222 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2223 ( $term_pid == $$ or resetterm(1) ),
2224
69893cff 2225 # ... and we got a line of command input ...
e22ea7cc
RF
2226 defined(
2227 $cmd = &readline(
2cbb2ee1 2228 "$pidprompt $tid DB"
e22ea7cc
RF
2229 . ( '<' x $level )
2230 . ( $#hist + 1 )
2231 . ( '>' x $level ) . " "
69893cff
RGS
2232 )
2233 )
2234 )
2235 {
e22ea7cc 2236
2cbb2ee1 2237 share($cmd);
69893cff
RGS
2238 # ... try to execute the input as debugger commands.
2239
2240 # Don't stop running.
2241 $single = 0;
2242
2243 # No signal is active.
2244 $signal = 0;
2245
2246 # Handle continued commands (ending with \):
e22ea7cc
RF
2247 $cmd =~ s/\\$/\n/ && do {
2248 $cmd .= &readline(" cont: ");
2249 redo CMD;
2250 };
69893cff
RGS
2251
2252=head4 The null command
2253
be9a9b1d 2254A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2255command out of C<$laststep> (where it was recorded previously), and copy it
2256back into C<$cmd> to be executed below. If there wasn't any previous command,
2257we'll do nothing below (no command will match). If there was, we also save it
2258in the command history and fall through to allow the command parsing to pick
2259it up.
2260
2261=cut
2262
2263 # Empty input means repeat the last command.
e22ea7cc
RF
2264 $cmd =~ /^$/ && ( $cmd = $laststep );
2265 chomp($cmd); # get rid of the annoying extra newline
2266 push( @hist, $cmd ) if length($cmd) > 1;
2267 push( @truehist, $cmd );
2cbb2ee1
RGS
2268 share(@hist);
2269 share(@truehist);
e22ea7cc
RF
2270
2271 # This is a restart point for commands that didn't arrive
2272 # via direct user input. It allows us to 'redo PIPE' to
2273 # re-execute command processing without reading a new command.
69893cff 2274 PIPE: {
e22ea7cc
RF
2275 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2276 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2277 ($i) = split( /\s+/, $cmd );
69893cff
RGS
2278
2279=head3 COMMAND ALIASES
2280
2281The debugger can create aliases for commands (these are stored in the
2282C<%alias> hash). Before a command is executed, the command loop looks it up
2283in the alias hash and substitutes the contents of the alias for the command,
2284completely replacing it.
2285
2286=cut
2287
2288 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2289 if ( $alias{$i} ) {
2290
69893cff
RGS
2291 # Squelch signal handling; we want to keep control here
2292 # if something goes loco during the alias eval.
2293 local $SIG{__DIE__};
2294 local $SIG{__WARN__};
2295
2296 # This is a command, so we eval it in the DEBUGGER's
2297 # scope! Otherwise, we can't see the special debugger
2298 # variables, or get to the debugger's subs. (Well, we
2299 # _could_, but why make it even more complicated?)
2300 eval "\$cmd =~ $alias{$i}";
2301 if ($@) {
2302 local $\ = '';
2303 print $OUT "Couldn't evaluate `$i' alias: $@";
2304 next CMD;
2305 }
2306 } ## end if ($alias{$i})
2307
2308=head3 MAIN-LINE COMMANDS
2309
2310All of these commands work up to and after the program being debugged has
2311terminated.
2312
2313=head4 C<q> - quit
2314
2315Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2316try to execute further, cleaning any restart-related stuff out of the
2317environment, and executing with the last value of C<$?>.
2318
2319=cut
2320
2321 $cmd =~ /^q$/ && do {
2322 $fall_off_end = 1;
2323 clean_ENV();
2324 exit $?;
2325 };
2326
2327=head4 C<t> - trace
2328
2329Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2330
2331=cut
2332
e22ea7cc
RF
2333 $cmd =~ /^t$/ && do {
2334 $trace ^= 1;
2335 local $\ = '';
2336 print $OUT "Trace = "
2337 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2338 next CMD;
2339 };
69893cff
RGS
2340
2341=head4 C<S> - list subroutines matching/not matching a pattern
2342
2343Walks through C<%sub>, checking to see whether or not to print the name.
2344
2345=cut
2346
e22ea7cc 2347 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
69893cff 2348
e22ea7cc 2349 $Srev = defined $2; # Reverse scan?
69893cff
RGS
2350 $Spatt = $3; # The pattern (if any) to use.
2351 $Snocheck = !defined $1; # No args - print all subs.
2352
2353 # Need to make these sane here.
e22ea7cc
RF
2354 local $\ = '';
2355 local $, = '';
69893cff
RGS
2356
2357 # Search through the debugger's magical hash of subs.
2358 # If $nocheck is true, just print the sub name.
2359 # Otherwise, check it against the pattern. We then use
2360 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2361 foreach $subname ( sort( keys %sub ) ) {
2362 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2363 print $OUT $subname, "\n";
2364 }
2365 }
2366 next CMD;
2367 };
69893cff
RGS
2368
2369=head4 C<X> - list variables in current package
2370
2371Since the C<V> command actually processes this, just change this to the
2372appropriate C<V> command and fall through.
2373
2374=cut
2375
e22ea7cc 2376 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2377
2378=head4 C<V> - list variables
2379
2380Uses C<dumpvar.pl> to dump out the current values for selected variables.
2381
2382=cut
2383
2384 # Bare V commands get the currently-being-debugged package
2385 # added.
e22ea7cc
RF
2386 $cmd =~ /^V$/ && do {
2387 $cmd = "V $package";
2388 };
69893cff
RGS
2389
2390 # V - show variables in package.
2391 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
e22ea7cc 2392
69893cff
RGS
2393 # Save the currently selected filehandle and
2394 # force output to debugger's filehandle (dumpvar
2395 # just does "print" for output).
e22ea7cc 2396 local ($savout) = select($OUT);
69893cff
RGS
2397
2398 # Grab package name and variables to dump.
e22ea7cc
RF
2399 $packname = $1;
2400 @vars = split( ' ', $2 );
69893cff
RGS
2401
2402 # If main::dumpvar isn't here, get it.
e81465be 2403 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2404 if ( defined &main::dumpvar ) {
2405
69893cff
RGS
2406 # We got it. Turn off subroutine entry/exit messages
2407 # for the moment, along with return values.
e22ea7cc
RF
2408 local $frame = 0;
2409 local $doret = -2;
69893cff
RGS
2410
2411 # must detect sigpipe failures - not catching
2412 # then will cause the debugger to die.
2413 eval {
2414 &main::dumpvar(
2415 $packname,
2416 defined $option{dumpDepth}
e22ea7cc
RF
2417 ? $option{dumpDepth}
2418 : -1, # assume -1 unless specified
69893cff 2419 @vars
e22ea7cc
RF
2420 );
2421 };
2422
2423 # The die doesn't need to include the $@, because
2424 # it will automatically get propagated for us.
2425 if ($@) {
2426 die unless $@ =~ /dumpvar print failed/;
2427 }
2428 } ## end if (defined &main::dumpvar)
2429 else {
2430
2431 # Couldn't load dumpvar.
2432 print $OUT "dumpvar.pl not available.\n";
2433 }
69893cff 2434
69893cff 2435 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2436 select($savout);
2437 next CMD;
2438 };
69893cff
RGS
2439
2440=head4 C<x> - evaluate and print an expression
2441
2442Hands the expression off to C<DB::eval>, setting it up to print the value
2443via C<dumpvar.pl> instead of just printing it directly.
2444
2445=cut
2446
e22ea7cc
RF
2447 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2448 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2449
2450 # handle special "x 3 blah" syntax XXX propagate
2451 # doc back to special variables.
e22ea7cc
RF
2452 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2453 $onetimedumpDepth = $1;
2454 }
2455 };
69893cff
RGS
2456
2457=head4 C<m> - print methods
2458
2459Just uses C<DB::methods> to determine what methods are available.
2460
2461=cut
2462
e22ea7cc
RF
2463 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2464 methods($1);
2465 next CMD;
2466 };
69893cff
RGS
2467
2468 # m expr - set up DB::eval to do the work
e22ea7cc
RF
2469 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2470 $onetimeDump = 'methods'; # method output gets used there
2471 };
69893cff
RGS
2472
2473=head4 C<f> - switch files
2474
2475=cut
2476
e22ea7cc
RF
2477 $cmd =~ /^f\b\s*(.*)/ && do {
2478 $file = $1;
2479 $file =~ s/\s+$//;
69893cff
RGS
2480
2481 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2482 if ( !$file ) {
2483 print $OUT
2484 "The old f command is now the r command.\n"; # hint
2485 print $OUT "The new f command switches filenames.\n";
2486 next CMD;
2487 } ## end if (!$file)
69893cff
RGS
2488
2489 # if not in magic file list, try a close match.
e22ea7cc
RF
2490 if ( !defined $main::{ '_<' . $file } ) {
2491 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2492 {
2493 $try = substr( $try, 2 );
2494 print $OUT "Choosing $try matching `$file':\n";
2495 $file = $try;
2496 }
2497 } ## end if (($try) = grep(m#^_<.*$file#...
2498 } ## end if (!defined $main::{ ...
69893cff
RGS
2499
2500 # If not successfully switched now, we failed.
e22ea7cc
RF
2501 if ( !defined $main::{ '_<' . $file } ) {
2502 print $OUT "No file matching `$file' is loaded.\n";
2503 next CMD;
2504 }
69893cff 2505
e22ea7cc
RF
2506 # We switched, so switch the debugger internals around.
2507 elsif ( $file ne $filename ) {
2508 *dbline = $main::{ '_<' . $file };
2509 $max = $#dbline;
2510 $filename = $file;
2511 $start = 1;
2512 $cmd = "l";
2513 } ## end elsif ($file ne $filename)
2514
2515 # We didn't switch; say we didn't.
2516 else {
2517 print $OUT "Already in $file.\n";
2518 next CMD;
2519 }
2520 };
69893cff
RGS
2521
2522=head4 C<.> - return to last-executed line.
2523
2524We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2525and then we look up the line in the magical C<%dbline> hash.
2526
2527=cut
2528
2529 # . command.
e22ea7cc
RF
2530 $cmd =~ /^\.$/ && do {
2531 $incr = -1; # stay at current line
69893cff
RGS
2532
2533 # Reset everything to the old location.
e22ea7cc
RF
2534 $start = $line;
2535 $filename = $filename_ini;
2536 *dbline = $main::{ '_<' . $filename };
2537 $max = $#dbline;
69893cff
RGS
2538
2539 # Now where are we?
e22ea7cc
RF
2540 print_lineinfo($position);
2541 next CMD;
2542 };
69893cff
RGS
2543
2544=head4 C<-> - back one window
2545
2546We change C<$start> to be one window back; if we go back past the first line,
2547we set it to be the first line. We ser C<$incr> to put us back at the
2548currently-executing line, and then put a C<l $start +> (list one window from
2549C<$start>) in C<$cmd> to be executed later.
2550
2551=cut
2552
2553 # - - back a window.
e22ea7cc
RF
2554 $cmd =~ /^-$/ && do {
2555
69893cff 2556 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2557 $start -= $incr + $window + 1;
2558 $start = 1 if $start <= 0;
2559 $incr = $window - 1;
69893cff
RGS
2560
2561 # Generate and execute a "l +" command (handled below).
e22ea7cc
RF
2562 $cmd = 'l ' . ($start) . '+';
2563 };
69893cff
RGS
2564
2565=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>, {, {{>
2566
2567In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2568problems, most notably that the default case of several commands destroying
2569the user's work in setting watchpoints, actions, etc. We wanted, however, to
2570retain the old commands for those who were used to using them or who preferred
2571them. At this point, we check for the new commands and call C<cmd_wrapper> to
2572deal with them instead of processing them in-line.
2573
2574=cut
2575
2576 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2577 # we send them off to the secondary dispatcher (see below).
2cbb2ee1 2578 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
e22ea7cc
RF
2579 &cmd_wrapper( $1, $2, $line );
2580 next CMD;
2581 };
69893cff
RGS
2582
2583=head4 C<y> - List lexicals in higher scope
2584
2585Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2586above the current one and then displays then using C<dumpvar.pl>.
2587
2588=cut
2589
2590 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2591
2592 # See if we've got the necessary support.
2593 eval { require PadWalker; PadWalker->VERSION(0.08) }
2594 or &warn(
2595 $@ =~ /locate/
2596 ? "PadWalker module not found - please install\n"
2597 : $@
2598 )
2599 and next CMD;
2600
2601 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2602 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2603 defined &main::dumpvar
2604 or print $OUT "dumpvar.pl not available.\n"
2605 and next CMD;
2606
2607 # Got all the modules we need. Find them and print them.
e22ea7cc 2608 my @vars = split( ' ', $2 || '' );
69893cff
RGS
2609
2610 # Find the pad.
e22ea7cc 2611 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
69893cff
RGS
2612
2613 # Oops. Can't find it.
2614 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2615
2616 # Show the desired vars with dumplex().
2617 my $savout = select($OUT);
2618
2619 # Have dumplex dump the lexicals.
e22ea7cc 2620 dumpvar::dumplex( $_, $h->{$_},
69893cff 2621 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2622 @vars )
2623 for sort keys %$h;
69893cff
RGS
2624 select($savout);
2625 next CMD;
2626 };
2627
2628=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2629
2630All of the commands below this point don't work after the program being
2631debugged has ended. All of them check to see if the program has ended; this
2632allows the commands to be relocated without worrying about a 'line of
2633demarcation' above which commands can be entered anytime, and below which
2634they can't.
2635
2636=head4 C<n> - single step, but don't trace down into subs
2637
2638Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2639when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
69893cff
RGS
2640so a null command knows what to re-execute.
2641
2642=cut
2643
e22ea7cc 2644 # n - next
69893cff
RGS
2645 $cmd =~ /^n$/ && do {
2646 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2647
69893cff
RGS
2648 # Single step, but don't enter subs.
2649 $single = 2;
e22ea7cc 2650
69893cff 2651 # Save for empty command (repeat last).
e22ea7cc
RF
2652 $laststep = $cmd;
2653 last CMD;
2654 };
69893cff
RGS
2655
2656=head4 C<s> - single-step, entering subs
2657
be9a9b1d 2658Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2659subs. Also saves C<s> as C<$lastcmd>.
2660
2661=cut
2662
2663 # s - single step.
2664 $cmd =~ /^s$/ && do {
e22ea7cc 2665
69893cff
RGS
2666 # Get out and restart the command loop if program
2667 # has finished.
e22ea7cc
RF
2668 end_report(), next CMD if $finished and $level <= 1;
2669
69893cff 2670 # Single step should enter subs.
e22ea7cc
RF
2671 $single = 1;
2672
69893cff 2673 # Save for empty command (repeat last).
e22ea7cc
RF
2674 $laststep = $cmd;
2675 last CMD;
2676 };
69893cff
RGS
2677
2678=head4 C<c> - run continuously, setting an optional breakpoint
2679
2680Most of the code for this command is taken up with locating the optional
2681breakpoint, which is either a subroutine name or a line number. We set
2682the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2683in this and all call levels above this one.
2684
2685=cut
2686
2687 # c - start continuous execution.
2688 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
e22ea7cc 2689
69893cff
RGS
2690 # Hey, show's over. The debugged program finished
2691 # executing already.
2692 end_report(), next CMD if $finished and $level <= 1;
2693
2694 # Capture the place to put a one-time break.
2695 $subname = $i = $1;
2696
e22ea7cc
RF
2697 # Probably not needed, since we finish an interactive
2698 # sub-session anyway...
2699 # local $filename = $filename;
2700 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2701 #
2702 # The above question wonders if localizing the alias
2703 # to the magic array works or not. Since it's commented
2704 # out, we'll just leave that to speculation for now.
2705
2706 # If the "subname" isn't all digits, we'll assume it
2707 # is a subroutine name, and try to find it.
e22ea7cc
RF
2708 if ( $subname =~ /\D/ ) { # subroutine name
2709 # Qualify it to the current package unless it's
2710 # already qualified.
69893cff
RGS
2711 $subname = $package . "::" . $subname
2712 unless $subname =~ /::/;
e22ea7cc 2713
69893cff
RGS
2714 # find_sub will return "file:line_number" corresponding
2715 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2716 # break up the return value, and assign it in one
69893cff 2717 # operation.
e22ea7cc 2718 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2719
2720 # Force the line number to be numeric.
e22ea7cc 2721 $i += 0;
69893cff
RGS
2722
2723 # If we got a line number, we found the sub.
e22ea7cc
RF
2724 if ($i) {
2725
69893cff
RGS
2726 # Switch all the debugger's internals around so
2727 # we're actually working with that file.
e22ea7cc
RF
2728 $filename = $file;
2729 *dbline = $main::{ '_<' . $filename };
2730
69893cff 2731 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2732 $had_breakpoints{$filename} |= 1;
2733
69893cff
RGS
2734 # Scan forward to the first executable line
2735 # after the 'sub whatever' line.
e22ea7cc
RF
2736 $max = $#dbline;
2737 ++$i while $dbline[$i] == 0 && $i < $max;
2738 } ## end if ($i)
69893cff
RGS
2739
2740 # We didn't find a sub by that name.
e22ea7cc
RF
2741 else {
2742 print $OUT "Subroutine $subname not found.\n";
2743 next CMD;
2744 }
2745 } ## end if ($subname =~ /\D/)
69893cff
RGS
2746
2747 # At this point, either the subname was all digits (an
2748 # absolute line-break request) or we've scanned through
2749 # the code following the definition of the sub, looking
2750 # for an executable, which we may or may not have found.
2751 #
2752 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2753 # got a request to break at some line somewhere. On
2754 # one hand, if there wasn't any real subroutine name
2755 # involved, this will be a request to break in the current
2756 # file at the specified line, so we have to check to make
69893cff
RGS
2757 # sure that the line specified really is breakable.
2758 #
2759 # On the other hand, if there was a subname supplied, the
3c4b39be 2760 # preceding block has moved us to the proper file and
69893cff
RGS
2761 # location within that file, and then scanned forward
2762 # looking for the next executable line. We have to make
2763 # sure that one was found.
2764 #
2765 # On the gripping hand, we can't do anything unless the
2766 # current value of $i points to a valid breakable line.
2767 # Check that.
e22ea7cc
RF
2768 if ($i) {
2769
69893cff 2770 # Breakable?
e22ea7cc
RF
2771 if ( $dbline[$i] == 0 ) {
2772 print $OUT "Line $i not breakable.\n";
2773 next CMD;
2774 }
2775
69893cff 2776 # Yes. Set up the one-time-break sigil.
e22ea7cc
RF
2777 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2778 } ## end if ($i)
69893cff
RGS
2779
2780 # Turn off stack tracing from here up.
e22ea7cc
RF
2781 for ( $i = 0 ; $i <= $stack_depth ; ) {
2782 $stack[ $i++ ] &= ~1;
2783 }
2784 last CMD;
2785 };
69893cff
RGS
2786
2787=head4 C<r> - return from a subroutine
2788
2789For C<r> to work properly, the debugger has to stop execution again
2790immediately after the return is executed. This is done by forcing
2791single-stepping to be on in the call level above the current one. If
2792we are printing return values when a C<r> is executed, set C<$doret>
2793appropriately, and force us out of the command loop.
2794
2795=cut
2796
2797 # r - return from the current subroutine.
e22ea7cc
RF
2798 $cmd =~ /^r$/ && do {
2799
69893cff 2800 # Can't do anythign if the program's over.
e22ea7cc
RF
2801 end_report(), next CMD if $finished and $level <= 1;
2802
69893cff 2803 # Turn on stack trace.
e22ea7cc
RF
2804 $stack[$stack_depth] |= 1;
2805
69893cff 2806 # Print return value unless the stack is empty.
e22ea7cc
RF
2807 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2808 last CMD;
2809 };
69893cff 2810
69893cff
RGS
2811=head4 C<T> - stack trace
2812
2813Just calls C<DB::print_trace>.
2814
2815=cut
2816
e22ea7cc
RF
2817 $cmd =~ /^T$/ && do {
2818 print_trace( $OUT, 1 ); # skip DB
2819 next CMD;
2820 };
69893cff
RGS
2821
2822=head4 C<w> - List window around current line.
2823
2824Just calls C<DB::cmd_w>.
2825
2826=cut
2827
e22ea7cc 2828 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
69893cff
RGS
2829
2830=head4 C<W> - watch-expression processing.
2831
2832Just calls C<DB::cmd_W>.
2833
2834=cut
2835
e22ea7cc 2836 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
69893cff
RGS
2837
2838=head4 C</> - search forward for a string in the source
2839
2840We take the argument and treat it as a pattern. If it turns out to be a
2841bad one, we return the error we got from trying to C<eval> it and exit.
2842If not, we create some code to do the search and C<eval> it so it can't
2843mess us up.
2844
2845=cut
2846
e22ea7cc 2847 $cmd =~ /^\/(.*)$/ && do {
69893cff
RGS
2848
2849 # The pattern as a string.
e22ea7cc 2850 $inpat = $1;
69893cff
RGS
2851
2852 # Remove the final slash.
e22ea7cc 2853 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2854
2855 # If the pattern isn't null ...
e22ea7cc 2856 if ( $inpat ne "" ) {
69893cff
RGS
2857
2858 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2859 local $SIG{__DIE__};
2860 local $SIG{__WARN__};
69893cff
RGS
2861
2862 # Create the pattern.
e22ea7cc
RF
2863 eval '$inpat =~ m' . "\a$inpat\a";
2864 if ( $@ ne "" ) {
2865
69893cff 2866 # Oops. Bad pattern. No biscuit.
e22ea7cc 2867 # Print the eval error and go back for more
69893cff 2868 # commands.
e22ea7cc
RF
2869 print $OUT "$@";
2870 next CMD;
2871 }
2872 $pat = $inpat;
2873 } ## end if ($inpat ne "")
69893cff
RGS
2874
2875 # Set up to stop on wrap-around.
e22ea7cc 2876 $end = $start;
69893cff
RGS
2877
2878 # Don't move off the current line.
e22ea7cc 2879 $incr = -1;
69893cff
RGS
2880
2881 # Done in eval so nothing breaks if the pattern
2882 # does something weird.
e22ea7cc
RF
2883 eval '
2884 for (;;) {
69893cff 2885 # Move ahead one line.
e22ea7cc 2886 ++$start;
69893cff
RGS
2887
2888 # Wrap if we pass the last line.
e22ea7cc 2889 $start = 1 if ($start > $max);
69893cff
RGS
2890
2891 # Stop if we have gotten back to this line again,
e22ea7cc 2892 last if ($start == $end);
69893cff
RGS
2893
2894 # A hit! (Note, though, that we are doing
2895 # case-insensitive matching. Maybe a qr//
2896 # expression would be better, so the user could
2897 # do case-sensitive matching if desired.
e22ea7cc
RF
2898 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2899 if ($slave_editor) {
69893cff 2900 # Handle proper escaping in the slave.
e22ea7cc
RF
2901 print $OUT "\032\032$filename:$start:0\n";
2902 }
2903 else {
69893cff 2904 # Just print the line normally.
e22ea7cc
RF
2905 print $OUT "$start:\t",$dbline[$start],"\n";
2906 }
69893cff 2907 # And quit since we found something.
e22ea7cc
RF
2908 last;
2909 }
2910 } ';
2911
69893cff 2912 # If we wrapped, there never was a match.
e22ea7cc
RF
2913 print $OUT "/$pat/: not found\n" if ( $start == $end );
2914 next CMD;
2915 };
69893cff
RGS
2916
2917=head4 C<?> - search backward for a string in the source
2918
2919Same as for C</>, except the loop runs backwards.
2920
2921=cut
2922
2923 # ? - backward pattern search.
e22ea7cc 2924 $cmd =~ /^\?(.*)$/ && do {
69893cff
RGS
2925
2926 # Get the pattern, remove trailing question mark.
e22ea7cc
RF
2927 $inpat = $1;
2928 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2929
2930 # If we've got one ...
e22ea7cc 2931 if ( $inpat ne "" ) {
69893cff
RGS
2932
2933 # Turn off die & warn handlers.
e22ea7cc
RF
2934 local $SIG{__DIE__};
2935 local $SIG{__WARN__};
2936 eval '$inpat =~ m' . "\a$inpat\a";
2937
2938 if ( $@ ne "" ) {
2939
69893cff 2940 # Ouch. Not good. Print the error.
e22ea7cc
RF
2941 print $OUT $@;
2942 next CMD;
2943 }
2944 $pat = $inpat;
69893cff 2945 } ## end if ($inpat ne "")
e22ea7cc 2946
69893cff 2947 # Where we are now is where to stop after wraparound.
e22ea7cc 2948 $end = $start;
69893cff
RGS
2949
2950 # Don't move away from this line.
e22ea7cc 2951 $incr = -1;
69893cff
RGS
2952
2953 # Search inside the eval to prevent pattern badness
2954 # from killing us.
e22ea7cc
RF
2955 eval '
2956 for (;;) {
69893cff 2957 # Back up a line.
e22ea7cc 2958 --$start;
69893cff
RGS
2959
2960 # Wrap if we pass the first line.
e22ea7cc
RF
2961
2962 $start = $max if ($start <= 0);
69893cff
RGS
2963
2964 # Quit if we get back where we started,
e22ea7cc 2965 last if ($start == $end);
69893cff
RGS
2966
2967 # Match?
e22ea7cc
RF
2968 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2969 if ($slave_editor) {
69893cff 2970 # Yep, follow slave editor requirements.
e22ea7cc
RF
2971 print $OUT "\032\032$filename:$start:0\n";
2972 }
2973 else {
69893cff 2974 # Yep, just print normally.
e22ea7cc
RF
2975 print $OUT "$start:\t",$dbline[$start],"\n";
2976 }
69893cff
RGS
2977
2978 # Found, so done.
e22ea7cc
RF
2979 last;
2980 }
2981 } ';
2982
2983 # Say we failed if the loop never found anything,
2984 print $OUT "?$pat?: not found\n" if ( $start == $end );
2985 next CMD;
2986 };
69893cff
RGS
2987
2988=head4 C<$rc> - Recall command
2989
2990Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2991that the terminal supports history). It find the the command required, puts it
2992into C<$cmd>, and redoes the loop to execute it.
2993
2994=cut
2995
e22ea7cc
RF
2996 # $rc - recall command.
2997 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
69893cff
RGS
2998
2999 # No arguments, take one thing off history.
e22ea7cc 3000 pop(@hist) if length($cmd) > 1;
69893cff 3001
e22ea7cc 3002 # Relative (- found)?
69893cff 3003 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 3004 # N - go to that particular command slot or the last
69893cff 3005 # thing if nothing following.
e22ea7cc 3006 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
69893cff
RGS
3007
3008 # Pick out the command desired.
e22ea7cc 3009 $cmd = $hist[$i];
69893cff
RGS
3010
3011 # Print the command to be executed and restart the loop
3012 # with that command in the buffer.
e22ea7cc
RF
3013 print $OUT $cmd, "\n";
3014 redo CMD;
3015 };
69893cff
RGS
3016
3017=head4 C<$sh$sh> - C<system()> command
3018
3019Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3020C<STDOUT> from getting messed up.
3021
3022=cut
3023
3024 # $sh$sh - run a shell command (if it's all ASCII).
3025 # Can't run shell commands with Unicode in the debugger, hmm.
e22ea7cc
RF
3026 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3027
69893cff 3028 # System it.
e22ea7cc
RF
3029 &system($1);
3030 next CMD;
3031 };
69893cff
RGS
3032
3033=head4 C<$rc I<pattern> $rc> - Search command history
3034
3035Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3036If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3037
3038=cut
3039
e22ea7cc
RF
3040 # $rc pattern $rc - find a command in the history.
3041 $cmd =~ /^$rc([^$rc].*)$/ && do {
3042
69893cff 3043 # Create the pattern to use.
e22ea7cc 3044 $pat = "^$1";
69893cff
RGS
3045
3046 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 3047 pop(@hist) if length($cmd) > 1;
69893cff
RGS
3048
3049 # Look backward through the history.
e22ea7cc
RF
3050 for ( $i = $#hist ; $i ; --$i ) {
3051
69893cff 3052 # Stop if we find it.
e22ea7cc
RF
3053 last if $hist[$i] =~ /$pat/;
3054 }
3055
3056 if ( !$i ) {
69893cff 3057
69893cff 3058 # Never found it.
e22ea7cc
RF
3059 print $OUT "No such command!\n\n";
3060 next CMD;
3061 }
69893cff
RGS
3062
3063 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
3064 $cmd = $hist[$i];
3065 print $OUT $cmd, "\n";
3066 redo CMD;
3067 };
69893cff
RGS
3068
3069=head4 C<$sh> - Invoke a shell
3070
3071Uses C<DB::system> to invoke a shell.
3072
3073=cut
3074
3075 # $sh - start a shell.
e22ea7cc
RF
3076 $cmd =~ /^$sh$/ && do {
3077
69893cff
RGS
3078 # Run the user's shell. If none defined, run Bourne.
3079 # We resume execution when the shell terminates.
e22ea7cc
RF
3080 &system( $ENV{SHELL} || "/bin/sh" );
3081 next CMD;
3082 };
69893cff
RGS
3083
3084=head4 C<$sh I<command>> - Force execution of a command in a shell
3085
3086Like the above, but the command is passed to the shell. Again, we use
3087C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3088
3089=cut
3090
3091 # $sh command - start a shell and run a command in it.
e22ea7cc
RF
3092 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3093
3094 # XXX: using csh or tcsh destroys sigint retvals!
3095 #&system($1); # use this instead
69893cff
RGS
3096
3097 # use the user's shell, or Bourne if none defined.
e22ea7cc
RF
3098 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3099 next CMD;
3100 };
69893cff
RGS
3101
3102=head4 C<H> - display commands in history
3103
3104Prints the contents of C<@hist> (if any).
3105
3106=cut
3107
7fddc82f
RF
3108 $cmd =~ /^H\b\s*\*/ && do {
3109 @hist = @truehist = ();
3110 print $OUT "History cleansed\n";
3111 next CMD;
3112 };
e22ea7cc
RF
3113
3114 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3115
3116 # Anything other than negative numbers is ignored by
69893cff 3117 # the (incorrect) pattern, so this test does nothing.
e22ea7cc 3118 $end = $2 ? ( $#hist - $2 ) : 0;
69893cff
RGS
3119
3120 # Set to the minimum if less than zero.
e22ea7cc 3121 $hist = 0 if $hist < 0;
69893cff 3122
e22ea7cc 3123 # Start at the end of the array.
69893cff
RGS
3124 # Stay in while we're still above the ending value.
3125 # Tick back by one each time around the loop.
e22ea7cc 3126 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3127
3128 # Print the command unless it has no arguments.
e22ea7cc
RF
3129 print $OUT "$i: ", $hist[$i], "\n"
3130 unless $hist[$i] =~ /^.?$/;
3131 }
3132 next CMD;
3133 };
69893cff
RGS
3134
3135=head4 C<man, doc, perldoc> - look up documentation
3136
3137Just calls C<runman()> to print the appropriate document.
3138
3139=cut
3140
e22ea7cc
RF
3141 # man, perldoc, doc - show manual pages.
3142 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3143 runman($1);
3144 next CMD;
3145 };
69893cff
RGS
3146
3147=head4 C<p> - print
3148
3149Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3150the bottom of the loop.
3151
3152=cut
3153
3154 # p - print (no args): print $_.
e22ea7cc 3155 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
69893cff
RGS
3156
3157 # p - print the given expression.
e22ea7cc 3158 $cmd =~ s/^p\b/print {\$DB::OUT} /;
69893cff
RGS
3159
3160=head4 C<=> - define command alias
3161
3162Manipulates C<%alias> to add or list command aliases.
3163
3164=cut
3165
e22ea7cc
RF
3166 # = - set up a command alias.
3167 $cmd =~ s/^=\s*// && do {
3168 my @keys;
3169 if ( length $cmd == 0 ) {
3170
69893cff 3171 # No args, get current aliases.
e22ea7cc
RF
3172 @keys = sort keys %alias;
3173 }
3174 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3175
69893cff
RGS
3176 # Creating a new alias. $k is alias name, $v is
3177 # alias value.
3178
e22ea7cc
RF
3179 # can't use $_ or kill //g state
3180 for my $x ( $k, $v ) {
3181
3182 # Escape "alarm" characters.
3183 $x =~ s/\a/\\a/g;
3184 }
69893cff
RGS
3185
3186 # Substitute key for value, using alarm chars
e22ea7cc 3187 # as separators (which is why we escaped them in
69893cff 3188 # the command).
e22ea7cc 3189 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3190
3191 # Turn off standard warn and die behavior.
e22ea7cc
RF
3192 local $SIG{__DIE__};
3193 local $SIG{__WARN__};
69893cff
RGS
3194
3195 # Is it valid Perl?
e22ea7cc
RF
3196 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3197
69893cff 3198 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3199 print $OUT "Can't alias $k to $v: $@\n";
3200 delete $alias{$k};
3201 next CMD;
3202 }
3203
69893cff 3204 # We'll only list the new one.
e22ea7cc 3205 @keys = ($k);
69893cff
RGS
3206 } ## end elsif (my ($k, $v) = ($cmd...
3207
3208 # The argument is the alias to list.
e22ea7cc
RF
3209 else {
3210 @keys = ($cmd);
3211 }
69893cff
RGS
3212
3213 # List aliases.
e22ea7cc
RF
3214 for my $k (@keys) {
3215
69893cff
RGS
3216 # Messy metaquoting: Trim the substiution code off.
3217 # We use control-G as the delimiter because it's not
3218 # likely to appear in the alias.
e22ea7cc
RF
3219 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3220
69893cff 3221 # Print the alias.
e22ea7cc
RF
3222 print $OUT "$k\t= $1\n";
3223 }
3224 elsif ( defined $alias{$k} ) {
3225
69893cff 3226 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3227 print $OUT "$k\t$alias{$k}\n";
3228 }
3229 else {
3230
69893cff 3231 # No such, dude.
e22ea7cc
RF
3232 print "No alias for $k\n";
3233 }
69893cff 3234 } ## end for my $k (@keys)
e22ea7cc
RF
3235 next CMD;
3236 };
69893cff
RGS
3237
3238=head4 C<source> - read commands from a file.
3239
3240Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3241pick it up.
3242
3243=cut
3244
e22ea7cc
RF
3245 # source - read commands from a file (or pipe!) and execute.
3246 $cmd =~ /^source\s+(.*\S)/ && do {
3247 if ( open my $fh, $1 ) {
3248
69893cff 3249 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3250 push @cmdfhs, $fh;
3251 }
3252 else {
3253
3254 # Couldn't open it.
3255 &warn("Can't execute `$1': $!\n");
3256 }
3257 next CMD;
3258 };
69893cff
RGS
3259
3260=head4 C<save> - send current history to a file
3261
3262Takes the complete history, (not the shrunken version you see with C<H>),
3263and saves it to the given filename, so it can be replayed using C<source>.
3264
3265Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3266
3267=cut
3268
3269 # save source - write commands to a file for later use
3270 $cmd =~ /^save\s*(.*)$/ && do {
e22ea7cc
RF
3271 my $file = $1 || '.perl5dbrc'; # default?
3272 if ( open my $fh, "> $file" ) {
3273
3274 # chomp to remove extraneous newlines from source'd files
3275 chomp( my @truelist =
3276 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3277 @truehist );
3278 print $fh join( "\n", @truelist );
69893cff 3279 print "commands saved in $file\n";
e22ea7cc
RF
3280 }
3281 else {
69893cff
RGS
3282 &warn("Can't save debugger commands in '$1': $!\n");
3283 }
3284 next CMD;
3285 };
3286
7fddc82f
RF
3287=head4 C<R> - restart
3288
3289Restart the debugger session.
3290
3291=head4 C<rerun> - rerun the current session
3292
3293Return to any given position in the B<true>-history list
3294
3295=cut
3296
3297 # R - restart execution.
3298 # rerun - controlled restart execution.
3299 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3300 my @args = ($1 eq 'R' ? restart() : rerun($2));
3301
ca28b541
AP
3302 # Close all non-system fds for a clean restart. A more
3303 # correct method would be to close all fds that were not
3304 # open when the process started, but this seems to be
3305 # hard. See "debugger 'R'estart and open database
3306 # connections" on p5p.
3307
47d3bbda 3308 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541
AP
3309 if (eval { require POSIX }) {
3310 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3311 }
3312
3313 if (defined $max_fd) {
3314 foreach ($^F+1 .. $max_fd-1) {
3315 next unless open FD_TO_CLOSE, "<&=$_";
3316 close(FD_TO_CLOSE);
3317 }
3318 }
3319
7fddc82f
RF
3320 # And run Perl again. We use exec() to keep the
3321 # PID stable (and that way $ini_pids is still valid).
3322 exec(@args) || print $OUT "exec failed: $!\n";
3323
3324 last CMD;
3325 };
3326
69893cff
RGS
3327=head4 C<|, ||> - pipe output through the pager.
3328
be9a9b1d 3329For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3330(the program's standard output). For C<||>, we only save C<OUT>. We open a
3331pipe to the pager (restoring the output filehandles if this fails). If this
3332is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3333set C<$signal>, sending us back into the debugger.
3334
3335We then trim off the pipe symbols and C<redo> the command loop at the
3336C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3337reading another.
3338
3339=cut
3340
3341 # || - run command in the pager, with output to DB::OUT.
e22ea7cc
RF
3342 $cmd =~ /^\|\|?\s*[^|]/ && do {
3343 if ( $pager =~ /^\|/ ) {
3344
69893cff 3345 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3346 open( SAVEOUT, ">&STDOUT" )
3347 || &warn("Can't save STDOUT");
3348 open( STDOUT, ">&OUT" )
3349 || &warn("Can't redirect STDOUT");
69893cff 3350 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3351 else {
3352
69893cff 3353 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3354 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3355 }
69893cff
RGS
3356
3357 # Fix up environment to record we have less if so.
e22ea7cc
RF
3358 fix_less();
3359
3360 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3361
69893cff 3362 # Couldn't open pipe to pager.
e22ea7cc
RF
3363 &warn("Can't pipe output to `$pager'");
3364 if ( $pager =~ /^\|/ ) {
3365
69893cff 3366 # Redirect I/O back again.
e22ea7cc
RF
3367 open( OUT, ">&STDOUT" ) # XXX: lost message
3368 || &warn("Can't restore DB::OUT");
3369 open( STDOUT, ">&SAVEOUT" )
3370 || &warn("Can't restore STDOUT");
3371 close(SAVEOUT);
69893cff 3372 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3373 else {
3374
69893cff 3375 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3376 open( OUT, ">&STDOUT" ) # XXX: lost message
3377 || &warn("Can't restore DB::OUT");
3378 }
3379 next CMD;
69893cff
RGS
3380 } ## end unless ($piped = open(OUT,...
3381
3382 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3383 $SIG{PIPE} = \&DB::catch
3384 if $pager =~ /^\|/
3385 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff
RGS
3386
3387 # Save current filehandle, unbuffer out, and put it back.
e22ea7cc
RF
3388 $selected = select(OUT);
3389 $| = 1;
69893cff
RGS
3390
3391 # Don't put it back if pager was a pipe.
e22ea7cc 3392 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3393
3394 # Trim off the pipe symbols and run the command now.
e22ea7cc
RF
3395 $cmd =~ s/^\|+\s*//;
3396 redo PIPE;
3397 };
69893cff
RGS
3398
3399=head3 END OF COMMAND PARSING
3400
3401Anything left in C<$cmd> at this point is a Perl expression that we want to
3402evaluate. We'll always evaluate in the user's context, and fully qualify
3403any variables we might want to address in the C<DB> package.
3404
3405=cut
3406
3407 # t - turn trace on.
e22ea7cc 3408 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
69893cff
RGS
3409
3410 # s - single-step. Remember the last command was 's'.
e22ea7cc 3411 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
69893cff
RGS
3412
3413 # n - single-step, but not into subs. Remember last command
e22ea7cc
RF
3414 # was 'n'.
3415 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
69893cff 3416
e22ea7cc 3417 } # PIPE:
69893cff 3418
e22ea7cc 3419 # Make sure the flag that says "the debugger's running" is
69893cff 3420 # still on, to make sure we get control again.
e22ea7cc 3421 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3422
3423 # Run *our* eval that executes in the caller's context.
e22ea7cc 3424 &eval;
69893cff
RGS
3425
3426 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3427 if ($onetimeDump) {
3428 $onetimeDump = undef;
69893cff 3429 $onetimedumpDepth = undef;
e22ea7cc
RF
3430 }
3431 elsif ( $term_pid == $$ ) {
c7e68384
IZ
3432 eval { # May run under miniperl, when not available...
3433 STDOUT->flush();
3434 STDERR->flush();
3435 };
e22ea7cc 3436
69893cff 3437 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3438 print $OUT "\n";
3439 }
3440 } ## end while (($term || &setterm...
69893cff
RGS
3441
3442=head3 POST-COMMAND PROCESSING
3443
3444After each command, we check to see if the command output was piped anywhere.
3445If so, we go through the necessary code to unhook the pipe and go back to
3446our standard filehandles for input and output.
3447
3448=cut
3449
e22ea7cc 3450 continue { # CMD:
69893cff
RGS
3451
3452 # At the end of every command:
e22ea7cc
RF
3453 if ($piped) {
3454
69893cff 3455 # Unhook the pipe mechanism now.
e22ea7cc
RF
3456 if ( $pager =~ /^\|/ ) {
3457
69893cff 3458 # No error from the child.
e22ea7cc 3459 $? = 0;
69893cff 3460
e22ea7cc
RF
3461 # we cannot warn here: the handle is missing --tchrist
3462 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3463
e22ea7cc 3464 # most of the $? crud was coping with broken cshisms
69893cff 3465 # $? is explicitly set to 0, so this never runs.
e22ea7cc
RF
3466 if ($?) {
3467 print SAVEOUT "Pager `$pager' failed: ";
3468 if ( $? == -1 ) {
3469 print SAVEOUT "shell returned -1\n";
3470 }
3471 elsif ( $? >> 8 ) {
3472 print SAVEOUT ( $? & 127 )
3473 ? " (SIG#" . ( $? & 127 ) . ")"
3474 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3475 }
3476 else {
3477 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3478 }
69893cff
RGS
3479 } ## end if ($?)
3480
e22ea7cc 3481 # Reopen filehandle for our output (if we can) and
69893cff 3482 # restore STDOUT (if we can).
e22ea7cc
RF
3483 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3484 open( STDOUT, ">&SAVEOUT" )
3485 || &warn("Can't restore STDOUT");
69893cff
RGS
3486
3487 # Turn off pipe exception handler if necessary.
e22ea7cc 3488 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3489
e22ea7cc
RF
3490 # Will stop ignoring SIGPIPE if done like nohup(1)
3491 # does SIGINT but Perl doesn't give us a choice.
69893cff 3492 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3493 else {
3494
69893cff 3495 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3496 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3497 }
69893cff
RGS
3498
3499 # Close filehandle pager was using, restore the normal one
3500 # if necessary,
3501 close(SAVEOUT);
e22ea7cc 3502 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3503
3504 # No pipes now.
e22ea7cc 3505 $piped = "";
69893cff 3506 } ## end if ($piped)
e22ea7cc 3507 } # CMD:
69893cff
RGS
3508
3509=head3 COMMAND LOOP TERMINATION
3510
3511When commands have finished executing, we come here. If the user closed the
3512input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3513evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3514C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3515The interpreter will then execute the next line and then return control to us
3516again.
3517
3518=cut
3519
3520 # No more commands? Quit.
e22ea7cc 3521 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
69893cff
RGS
3522
3523 # Evaluate post-prompt commands.
e22ea7cc
RF
3524 foreach $evalarg (@$post) {
3525 &eval;
3526 }
3527 } # if ($single || $signal)
69893cff
RGS
3528
3529 # Put the user's globals back where you found them.
e22ea7cc 3530 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3531 ();
3532} ## end sub DB
3533
3534# The following code may be executed now:
3535# BEGIN {warn 4}
3536
3537=head2 sub
3538
3539C<sub> is called whenever a subroutine call happens in the program being
3540debugged. The variable C<$DB::sub> contains the name of the subroutine
3541being called.
3542
3543The core function of this subroutine is to actually call the sub in the proper
3544context, capturing its output. This of course causes C<DB::DB> to get called
3545again, repeating until the subroutine ends and returns control to C<DB::sub>
3546again. Once control returns, C<DB::sub> figures out whether or not to dump the
3547return value, and returns its captured copy of the return value as its own
3548return value. The value then feeds back into the program being debugged as if
3549C<DB::sub> hadn't been there at all.
3550
3551C<sub> does all the work of printing the subroutine entry and exit messages
3552enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3553and also prints the return value if needed (for the C<r> command and if
3554the 16 bit is set in C<$frame>).
3555
3556It also tracks the subroutine call depth by saving the current setting of
3557C<$single> in the C<@stack> package global; if this exceeds the value in
3558C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3559setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3560of stop/don't stop on entry to subs set as it currently is set.
3561
3562=head3 C<caller()> support
3563
3564If C<caller()> is called from the package C<DB>, it provides some
3565additional data, in the following order:
3566
3567=over 4
3568
3569=item * C<$package>
3570
3571The package name the sub was in
3572
3573=item * C<$filename>
3574
3575The filename it was defined in
3576
3577=item * C<$line>
3578
3579The line number it was defined on
3580
3581=item * C<$subroutine>
3582
be9a9b1d 3583The subroutine name; C<(eval)> if an C<eval>().
69893cff
RGS
3584
3585=item * C<$hasargs>
3586
35871 if it has arguments, 0 if not
3588
3589=item * C<$wantarray>
3590
35911 if array context, 0 if scalar context
3592
3593=item * C<$evaltext>
3594
3595The C<eval>() text, if any (undefined for C<eval BLOCK>)
3596
3597=item * C<$is_require>
3598
3599frame was created by a C<use> or C<require> statement
3600
3601=item * C<$hints>
3602
3603pragma information; subject to change between versions
3604
3605=item * C<$bitmask>
3606
be9a9b1d 3607pragma information; subject to change between versions
69893cff
RGS
3608
3609=item * C<@DB::args>
3610
3611arguments with which the subroutine was invoked
3612
3613=back
3614
3615=cut
d338d6fe 3616
d12a4851 3617sub sub {
b7bfa855
B
3618 # Do not use a regex in this subroutine -> results in corrupted memory
3619 # See: [perl #66110]
69893cff 3620
2cbb2ee1
RGS
3621 # lock ourselves under threads
3622 lock($DBGR);
3623
69893cff
RGS
3624 # Whether or not the autoloader was running, a scalar to put the
3625 # sub's return value in (if needed), and an array to put the sub's
3626 # return value in (if needed).
e22ea7cc 3627 my ( $al, $ret, @ret ) = "";
b7bfa855 3628 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) {
2cbb2ee1
RGS
3629 print "creating new thread\n";
3630 }
69893cff 3631
c81c05fc 3632 # If the last ten characters are '::AUTOLOAD', note we've traced
69893cff 3633 # into AUTOLOAD for $sub.
e22ea7cc 3634 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
c81c05fc 3635 $al = " for $$sub" if defined $$sub;
d12a4851 3636 }
69893cff
RGS
3637
3638 # We stack the stack pointer and then increment it to protect us
3639 # from a situation that might unwind a whole bunch of call frames
3640 # at once. Localizing the stack pointer means that it will automatically
3641 # unwind the same amount when multiple stack frames are unwound.
e22ea7cc 3642 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
69893cff
RGS
3643
3644 # Expand @stack.
d12a4851 3645 $#stack = $stack_depth;
69893cff
RGS
3646
3647 # Save current single-step setting.
d12a4851 3648 $stack[-1] = $single;
69893cff 3649
e22ea7cc 3650 # Turn off all flags except single-stepping.
d12a4851 3651 $single &= 1;
69893cff
RGS
3652
3653 # If we've gotten really deeply recursed, turn on the flag that will
3654 # make us stop with the 'deep recursion' message.
d12a4851 3655 $single |= 4 if $stack_depth == $deep;
69893cff
RGS
3656
3657 # If frame messages are on ...
3658 (
3659 $frame & 4 # Extended frame entry message
e22ea7cc
RF
3660 ? (
3661 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
69893cff 3662
e22ea7cc 3663 # Why -1? But it works! :-(
69893cff
RGS
3664 # Because print_trace will call add 1 to it and then call
3665 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3666 # in dump_trace.
e22ea7cc
RF
3667 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3668 )
3669 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3670
69893cff 3671 # standard frame entry message
e22ea7cc
RF
3672 )
3673 if $frame;
69893cff
RGS
3674
3675 # Determine the sub's return type,and capture approppriately.
d12a4851 3676 if (wantarray) {
e22ea7cc 3677
69893cff
RGS
3678 # Called in array context. call sub and capture output.
3679 # DB::DB will recursively get control again if appropriate; we'll come
3680 # back here when the sub is finished.
584420f0 3681 @ret = &$sub;
69893cff
RGS
3682
3683 # Pop the single-step value back off the stack.
e22ea7cc 3684 $single |= $stack[ $stack_depth-- ];
69893cff
RGS
3685
3686 # Check for exit trace messages...
e22ea7cc
RF
3687 (
3688 $frame & 4 # Extended exit message
3689 ? (
3690 print_lineinfo( ' ' x $stack_depth, "out " ),
3691 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3692 )
3693 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3694
69893cff 3695 # Standard exit message