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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:
5561b870 514$VERSION = 1.30;
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 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
SB
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
A
942# Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org>
943# + Added HistFile, HistSize
6fae1ad7 944########################################################################
d338d6fe 945
69893cff
RGS
946=head1 DEBUGGER INITIALIZATION
947
948The debugger starts up in phases.
949
950=head2 BASIC SETUP
951
952First, it initializes the environment it wants to run in: turning off
953warnings during its own compilation, defining variables which it will need
954to avoid warnings later, setting itself up to not exit when the program
955terminates, and defaulting to printing return values for the C<r> command.
956
957=cut
958
eda6e075 959# Needed for the statement after exec():
69893cff
RGS
960#
961# This BEGIN block is simply used to switch off warnings during debugger
962# compiliation. Probably it would be better practice to fix the warnings,
963# but this is how it's done at the moment.
eda6e075 964
e22ea7cc
RF
965BEGIN {
966 $ini_warn = $^W;
967 $^W = 0;
968} # Switch compilation warnings off until another BEGIN.
d12a4851
JH
969
970# test if assertions are supported and actived:
eda6e075 971BEGIN {
e22ea7cc
RF
972 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
973
d12a4851 974 # $ini_assertion = undef => assertions unsupported,
e22ea7cc 975 # " = 1 => assertions supported
d12a4851
JH
976 # print "\$ini_assertion=$ini_assertion\n";
977}
978
69893cff
RGS
979local ($^W) = 0; # Switch run-time warnings off during init.
980
2cbb2ee1
RGS
981=head2 THREADS SUPPORT
982
983If we are running under a threaded Perl, we require threads and threads::shared
984if the environment variable C<PERL5DB_THREADED> is set, to enable proper
985threaded debugger control. C<-dt> can also be used to set this.
986
987Each new thread will be announced and the debugger prompt will always inform
988you of each new thread created. It will also indicate the thread id in which
989we are currently running within the prompt like this:
990
991 [tid] DB<$i>
992
993Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
994command prompt. The prompt will show: C<[0]> when running under threads, but
995not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
996
997While running under threads, when you set or delete a breakpoint (etc.), this
998will apply to all threads, not just the currently running one. When you are
999in a currently executing thread, you will stay there until it completes. With
1000the current implementation it is not currently possible to hop from one thread
1001to another.
1002
1003The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
1004
1005Note that threading support was built into the debugger as of Perl version
1006C<5.8.6> and debugger version C<1.2.8>.
1007
1008=cut
1009
1010BEGIN {
1011 # ensure we can share our non-threaded variables or no-op
1012 if ($ENV{PERL5DB_THREADED}) {
1013 require threads;
1014 require threads::shared;
1015 import threads::shared qw(share);
1016 $DBGR;
1017 share(\$DBGR);
1018 lock($DBGR);
1019 print "Threads support enabled\n";
1020 } else {
1021 *lock = sub(*) {};
1022 *share = sub(*) {};
1023 }
1024}
1025
69893cff
RGS
1026# This would probably be better done with "use vars", but that wasn't around
1027# when this code was originally written. (Neither was "use strict".) And on
1028# the principle of not fiddling with something that was working, this was
1029# left alone.
1030warn( # Do not ;-)
2cbb2ee1 1031 # These variables control the execution of 'dumpvar.pl'.
69893cff
RGS
1032 $dumpvar::hashDepth,
1033 $dumpvar::arrayDepth,
1034 $dumpvar::dumpDBFiles,
1035 $dumpvar::dumpPackages,
1036 $dumpvar::quoteHighBit,
1037 $dumpvar::printUndef,
1038 $dumpvar::globPrint,
1039 $dumpvar::usageOnly,
1040
1041 # used to save @ARGV and extract any debugger-related flags.
1042 @ARGS,
1043
1044 # used to control die() reporting in diesignal()
1045 $Carp::CarpLevel,
1046
1047 # used to prevent multiple entries to diesignal()
1048 # (if for instance diesignal() itself dies)
1049 $panic,
1050
1051 # used to prevent the debugger from running nonstop
1052 # after a restart
1053 $second_time,
1054 )
1055 if 0;
d338d6fe 1056
2cbb2ee1
RGS
1057foreach my $k (keys (%INC)) {
1058 &share(\$main::{'_<'.$filename});
1059};
1060
54d04a52 1061# Command-line + PERLLIB:
69893cff 1062# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
1063@ini_INC = @INC;
1064
69893cff
RGS
1065# This was an attempt to clear out the previous values of various
1066# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe 1067# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1068
69893cff
RGS
1069# We set these variables to safe values. We don't want to blindly turn
1070# off warnings, because other packages may still want them.
e22ea7cc
RF
1071$trace = $signal = $single = 0; # Uninitialized warning suppression
1072 # (local $^W cannot help - other packages!).
69893cff
RGS
1073
1074# Default to not exiting when program finishes; print the return
1075# value when the 'r' command is used to return from a subroutine.
55497cff 1076$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 1077
69893cff
RGS
1078=head1 OPTION PROCESSING
1079
1080The debugger's options are actually spread out over the debugger itself and
1081C<dumpvar.pl>; some of these are variables to be set, while others are
1082subs to be called with a value. To try to make this a little easier to
1083manage, the debugger uses a few data structures to define what options
1084are legal and how they are to be processed.
1085
1086First, the C<@options> array defines the I<names> of all the options that
1087are to be accepted.
1088
1089=cut
1090
1091@options = qw(
5561b870 1092 CommandSet HistFile HistSize
e22ea7cc
RF
1093 hashDepth arrayDepth dumpDepth
1094 DumpDBFiles DumpPackages DumpReused
1095 compactDump veryCompact quote
1096 HighBit undefPrint globPrint
1097 PrintRet UsageOnly frame
1098 AutoTrace TTY noTTY
1099 ReadLine NonStop LineInfo
1100 maxTraceLen recallCommand ShellBang
1101 pager tkRunning ornaments
1102 signalLevel warnLevel dieLevel
1103 inhibit_exit ImmediateStop bareStringify
1104 CreateTTY RemotePort windowSize
1105 DollarCaretP OnlyAssertions WarnAssertions
1106);
d12a4851
JH
1107
1108@RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1109
69893cff
RGS
1110=pod
1111
1112Second, C<optionVars> lists the variables that each option uses to save its
1113state.
1114
1115=cut
1116
1117%optionVars = (
e22ea7cc
RF
1118 hashDepth => \$dumpvar::hashDepth,
1119 arrayDepth => \$dumpvar::arrayDepth,
1120 CommandSet => \$CommandSet,
1121 DumpDBFiles => \$dumpvar::dumpDBFiles,
1122 DumpPackages => \$dumpvar::dumpPackages,
1123 DumpReused => \$dumpvar::dumpReused,
1124 HighBit => \$dumpvar::quoteHighBit,
1125 undefPrint => \$dumpvar::printUndef,
1126 globPrint => \$dumpvar::globPrint,
1127 UsageOnly => \$dumpvar::usageOnly,
1128 CreateTTY => \$CreateTTY,
1129 bareStringify => \$dumpvar::bareStringify,
1130 frame => \$frame,
1131 AutoTrace => \$trace,
1132 inhibit_exit => \$inhibit_exit,
1133 maxTraceLen => \$maxtrace,
1134 ImmediateStop => \$ImmediateStop,
1135 RemotePort => \$remoteport,
1136 windowSize => \$window,
1137 WarnAssertions => \$warnassertions,
5561b870
A
1138 HistFile => \$histfile,
1139 HistSize => \$histsize,
69893cff
RGS
1140);
1141
1142=pod
1143
1144Third, C<%optionAction> defines the subroutine to be called to process each
1145option.
1146
1147=cut
1148
1149%optionAction = (
1150 compactDump => \&dumpvar::compactDump,
1151 veryCompact => \&dumpvar::veryCompact,
1152 quote => \&dumpvar::quote,
1153 TTY => \&TTY,
1154 noTTY => \&noTTY,
1155 ReadLine => \&ReadLine,
1156 NonStop => \&NonStop,
1157 LineInfo => \&LineInfo,
1158 recallCommand => \&recallCommand,
1159 ShellBang => \&shellBang,
1160 pager => \&pager,
1161 signalLevel => \&signalLevel,
1162 warnLevel => \&warnLevel,
1163 dieLevel => \&dieLevel,
1164 tkRunning => \&tkRunning,
1165 ornaments => \&ornaments,
1166 RemotePort => \&RemotePort,
1167 DollarCaretP => \&DollarCaretP,
1168 OnlyAssertions=> \&OnlyAssertions,
d12a4851
JH
1169);
1170
69893cff
RGS
1171=pod
1172
1173Last, the C<%optionRequire> notes modules that must be C<require>d if an
1174option is used.
1175
1176=cut
d338d6fe 1177
69893cff
RGS
1178# Note that this list is not complete: several options not listed here
1179# actually require that dumpvar.pl be loaded for them to work, but are
1180# not in the table. A subsequent patch will correct this problem; for
1181# the moment, we're just recommenting, and we are NOT going to change
1182# function.
eda6e075 1183%optionRequire = (
69893cff
RGS
1184 compactDump => 'dumpvar.pl',
1185 veryCompact => 'dumpvar.pl',
1186 quote => 'dumpvar.pl',
e22ea7cc 1187);
69893cff
RGS
1188
1189=pod
1190
1191There are a number of initialization-related variables which can be set
1192by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1193variable. These are:
1194
1195=over 4
1196
1197=item C<$rl> - readline control XXX needs more explanation
1198
1199=item C<$warnLevel> - whether or not debugger takes over warning handling
1200
1201=item C<$dieLevel> - whether or not debugger takes over die handling
1202
1203=item C<$signalLevel> - whether or not debugger takes over signal handling
1204
1205=item C<$pre> - preprompt actions (array reference)
1206
1207=item C<$post> - postprompt actions (array reference)
1208
1209=item C<$pretype>
1210
1211=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1212
1213=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1214
1215=back
1216
1217=cut
d338d6fe 1218
1219# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1220$rl = 1 unless defined $rl;
1221$warnLevel = 1 unless defined $warnLevel;
1222$dieLevel = 1 unless defined $dieLevel;
1223$signalLevel = 1 unless defined $signalLevel;
1224$pre = [] unless defined $pre;
1225$post = [] unless defined $post;
1226$pretype = [] unless defined $pretype;
1227$CreateTTY = 3 unless defined $CreateTTY;
1228$CommandSet = '580' unless defined $CommandSet;
1229
2cbb2ee1
RGS
1230share($rl);
1231share($warnLevel);
1232share($dieLevel);
1233share($signalLevel);
1234share($pre);
1235share($post);
1236share($pretype);
1237share($rl);
1238share($CreateTTY);
1239share($CommandSet);
1240
69893cff
RGS
1241=pod
1242
1243The default C<die>, C<warn>, and C<signal> handlers are set up.
1244
1245=cut
055fd3a9 1246
d338d6fe 1247warnLevel($warnLevel);
1248dieLevel($dieLevel);
1249signalLevel($signalLevel);
055fd3a9 1250
69893cff
RGS
1251=pod
1252
1253The pager to be used is needed next. We try to get it from the
5561b870 1254environment first. If it's not defined there, we try to find it in
69893cff
RGS
1255the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1256then call the C<pager()> function to save the pager name.
1257
1258=cut
1259
1260# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1261pager(
e22ea7cc 1262
69893cff 1263 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1264 defined $ENV{PAGER}
1265 ? $ENV{PAGER}
69893cff
RGS
1266
1267 # If not, see if Config.pm defines it.
e22ea7cc
RF
1268 : eval { require Config }
1269 && defined $Config::Config{pager}
1270 ? $Config::Config{pager}
69893cff
RGS
1271
1272 # If not, fall back to 'more'.
e22ea7cc
RF
1273 : 'more'
1274 )
1275 unless defined $pager;
69893cff
RGS
1276
1277=pod
1278
1279We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1280recall character (C<!> unless otherwise defined) and the shell escape
1281character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1282neither works in the debugger at the moment.
1283
1284=cut
1285
055fd3a9 1286setman();
69893cff
RGS
1287
1288# Set up defaults for command recall and shell escape (note:
1289# these currently don't work in linemode debugging).
d338d6fe 1290&recallCommand("!") unless defined $prc;
69893cff
RGS
1291&shellBang("!") unless defined $psh;
1292
1293=pod
1294
1295We then set up the gigantic string containing the debugger help.
1296We also set the limit on the number of arguments we'll display during a
1297trace.
1298
1299=cut
1300
04e43a21 1301sethelp();
69893cff
RGS
1302
1303# If we didn't get a default for the length of eval/stack trace args,
1304# set it here.
1d06cb2d 1305$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1306
1307=head2 SETTING UP THE DEBUGGER GREETING
1308
be9a9b1d 1309The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1310running, and whether the current debugger is the primary or a child.
1311
1312If we are the primary, we just hang onto our pid so we'll have it when
1313or if we start a child debugger. If we are a child, we'll set things up
1314so we'll have a unique greeting and so the parent will give us our own
1315TTY later.
1316
1317We save the current contents of the C<PERLDB_PIDS> environment variable
1318because we mess around with it. We'll also need to hang onto it because
1319we'll need it if we restart.
1320
1321Child debuggers make a label out of the current PID structure recorded in
1322PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1323yet so the parent will give them one later via C<resetterm()>.
1324
1325=cut
1326
e22ea7cc 1327# Save the current contents of the environment; we're about to
69893cff 1328# much with it. We'll need this if we have to restart.
f1583d8f 1329$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1330
e22ea7cc
RF
1331if ( defined $ENV{PERLDB_PIDS} ) {
1332
69893cff 1333 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1334 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1335 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1336
1337 my $env_pids = $ENV{PERLDB_PIDS};
1338 $pids = "[$env_pids]";
1339
1340 # Unless we are on OpenVMS, all programs under the DCL shell run under
1341 # the same PID.
1342
1343 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1344 $term_pid = $$;
1345 }
1346 else {
1347 $ENV{PERLDB_PIDS} .= "->$$";
1348 $term_pid = -1;
1349 }
1350
69893cff
RGS
1351} ## end if (defined $ENV{PERLDB_PIDS...
1352else {
e22ea7cc
RF
1353
1354 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1355 # child debugger, and mark us as the parent, so we'll know to set up
1356 # more TTY's is we have to.
1357 $ENV{PERLDB_PIDS} = "$$";
619a0444 1358 $pids = "[pid=$$]";
e22ea7cc 1359 $term_pid = $$;
f1583d8f 1360}
69893cff 1361
f1583d8f 1362$pidprompt = '';
69893cff
RGS
1363
1364# Sets up $emacs as a synonym for $slave_editor.
1365*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1366
1367=head2 READING THE RC FILE
1368
1369The debugger will read a file of initialization options if supplied. If
1370running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1371
1372=cut
1373
1374# As noted, this test really doesn't check accurately that the debugger
1375# is running at a terminal or not.
d338d6fe 1376
e22ea7cc
RF
1377if ( -e "/dev/tty" ) { # this is the wrong metric!
1378 $rcfile = ".perldb";
1379}
69893cff
RGS
1380else {
1381 $rcfile = "perldb.ini";
d338d6fe 1382}
1383
69893cff
RGS
1384=pod
1385
1386The debugger does a safety test of the file to be read. It must be owned
1387either by the current user or root, and must only be writable by the owner.
1388
1389=cut
1390
1391# This wraps a safety test around "do" to read and evaluate the init file.
1392#
055fd3a9
GS
1393# This isn't really safe, because there's a race
1394# between checking and opening. The solution is to
1395# open and fstat the handle, but then you have to read and
1396# eval the contents. But then the silly thing gets
69893cff
RGS
1397# your lexical scope, which is unfortunate at best.
1398sub safe_do {
055fd3a9
GS
1399 my $file = shift;
1400
1401 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1402 local $SIG{__WARN__};
1403 local $SIG{__DIE__};
055fd3a9 1404
e22ea7cc 1405 unless ( is_safe_file($file) ) {
69893cff 1406 CORE::warn <<EO_GRIPE;
055fd3a9
GS
1407perldb: Must not source insecure rcfile $file.
1408 You or the superuser must be the owner, and it must not
69893cff 1409 be writable by anyone but its owner.
055fd3a9 1410EO_GRIPE
69893cff
RGS
1411 return;
1412 } ## end unless (is_safe_file($file...
055fd3a9
GS
1413
1414 do $file;
1415 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1416} ## end sub safe_do
055fd3a9 1417
69893cff
RGS
1418# This is the safety test itself.
1419#
055fd3a9
GS
1420# Verifies that owner is either real user or superuser and that no
1421# one but owner may write to it. This function is of limited use
1422# when called on a path instead of upon a handle, because there are
1423# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1424# eventually accessed is the same as the one tested.
055fd3a9
GS
1425# Assumes that the file's existence is not in doubt.
1426sub is_safe_file {
1427 my $path = shift;
69893cff 1428 stat($path) || return; # mysteriously vaporized
e22ea7cc 1429 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1430
1431 return 0 if $uid != 0 && $uid != $<;
1432 return 0 if $mode & 022;
1433 return 1;
69893cff 1434} ## end sub is_safe_file
055fd3a9 1435
69893cff 1436# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1437# exists, we safely do it.
1438if ( -f $rcfile ) {
055fd3a9 1439 safe_do("./$rcfile");
69893cff 1440}
e22ea7cc 1441
69893cff 1442# If there isn't one here, try the user's home directory.
e22ea7cc 1443elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1444 safe_do("$ENV{HOME}/$rcfile");
1445}
e22ea7cc 1446
69893cff 1447# Else try the login directory.
e22ea7cc 1448elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1449 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe 1450}
1451
69893cff 1452# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1453if ( defined $ENV{PERLDB_OPTS} ) {
1454 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe 1455}
1456
69893cff
RGS
1457=pod
1458
1459The last thing we do during initialization is determine which subroutine is
1460to be used to obtain a new terminal when a new debugger is started. Right now,
6fae1ad7 1461the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
69893cff
RGS
1462
1463=cut
1464
1465# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1466# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1467# OS/2, or on Mac OS X. This may need some expansion.
1468
1469if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1470{
6fae1ad7
RF
1471 if (defined $ENV{TERM} # If we know what kind
1472 # of terminal this is,
1473 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1474 and defined $ENV{DISPLAY} # and what display it's on,
1475 )
1476 {
1477 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1478 }
1479 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1480 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1481 }
1482 elsif ( $^O eq 'darwin' # If this is Mac OS X
1483 and defined $ENV{TERM_PROGRAM} # and we're running inside
1484 and $ENV{TERM_PROGRAM}
1485 eq 'Apple_Terminal' # Terminal.app
1486 )
1487 {
1488 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1489 }
69893cff 1490} ## end if (not defined &get_fork_TTY...
e22ea7cc 1491
dbb46cec
DQ
1492# untaint $^O, which may have been tainted by the last statement.
1493# see bug [perl #24674]
e22ea7cc
RF
1494$^O =~ m/^(.*)\z/;
1495$^O = $1;
f1583d8f 1496
d12a4851 1497# Here begin the unreadable code. It needs fixing.
055fd3a9 1498
69893cff
RGS
1499=head2 RESTART PROCESSING
1500
1501This section handles the restart command. When the C<R> command is invoked, it
1502tries to capture all of the state it can into environment variables, and
1503then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1504if C<PERLDB_RESTART> is there; if so, we reload all the information that
1505the R command stuffed into the environment variables.
1506
1507 PERLDB_RESTART - flag only, contains no restart data itself.
1508 PERLDB_HIST - command history, if it's available
1509 PERLDB_ON_LOAD - breakpoints set by the rc file
1510 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1511 PERLDB_VISITED - files that had breakpoints
1512 PERLDB_FILE_... - breakpoints for a file
1513 PERLDB_OPT - active options
1514 PERLDB_INC - the original @INC
1515 PERLDB_PRETYPE - preprompt debugger actions
1516 PERLDB_PRE - preprompt Perl code
1517 PERLDB_POST - post-prompt Perl code
1518 PERLDB_TYPEAHEAD - typeahead captured by readline()
1519
1520We chug through all these variables and plug the values saved in them
1521back into the appropriate spots in the debugger.
1522
1523=cut
1524
e22ea7cc
RF
1525if ( exists $ENV{PERLDB_RESTART} ) {
1526
69893cff 1527 # We're restarting, so we don't need the flag that says to restart anymore.
e22ea7cc
RF
1528 delete $ENV{PERLDB_RESTART};
1529
1530 # $restart = 1;
1531 @hist = get_list('PERLDB_HIST');
1532 %break_on_load = get_list("PERLDB_ON_LOAD");
1533 %postponed = get_list("PERLDB_POSTPONE");
69893cff 1534
2cbb2ee1
RGS
1535 share(@hist);
1536 share(@truehist);
1537 share(%break_on_load);
1538 share(%postponed);
1539
69893cff 1540 # restore breakpoints/actions
e22ea7cc
RF
1541 my @had_breakpoints = get_list("PERLDB_VISITED");
1542 for ( 0 .. $#had_breakpoints ) {
1543 my %pf = get_list("PERLDB_FILE_$_");
1544 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1545 }
69893cff
RGS
1546
1547 # restore options
e22ea7cc
RF
1548 my %opt = get_list("PERLDB_OPT");
1549 my ( $opt, $val );
1550 while ( ( $opt, $val ) = each %opt ) {
1551 $val =~ s/[\\\']/\\$1/g;
1552 parse_options("$opt'$val'");
1553 }
69893cff
RGS
1554
1555 # restore original @INC
e22ea7cc
RF
1556 @INC = get_list("PERLDB_INC");
1557 @ini_INC = @INC;
1558
1559 # return pre/postprompt actions and typeahead buffer
1560 $pretype = [ get_list("PERLDB_PRETYPE") ];
1561 $pre = [ get_list("PERLDB_PRE") ];
1562 $post = [ get_list("PERLDB_POST") ];
1563 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1564} ## end if (exists $ENV{PERLDB_RESTART...
1565
1566=head2 SETTING UP THE TERMINAL
1567
1568Now, we'll decide how the debugger is going to interact with the user.
1569If there's no TTY, we set the debugger to run non-stop; there's not going
1570to be anyone there to enter commands.
1571
1572=cut
54d04a52 1573
d338d6fe 1574if ($notty) {
69893cff 1575 $runnonstop = 1;
2cbb2ee1 1576 share($runnonstop);
69893cff 1577}
d12a4851 1578
69893cff
RGS
1579=pod
1580
1581If there is a TTY, we have to determine who it belongs to before we can
1582proceed. If this is a slave editor or graphical debugger (denoted by
1583the first command-line switch being '-emacs'), we shift this off and
1584set C<$rl> to 0 (XXX ostensibly to do straight reads).
1585
1586=cut
1587
1588else {
e22ea7cc 1589
69893cff
RGS
1590 # Is Perl being run from a slave editor or graphical debugger?
1591 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1592 $slave_editor =
1593 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1594 $rl = 0, shift(@main::ARGV) if $slave_editor;
1595
1596 #require Term::ReadLine;
d12a4851 1597
69893cff
RGS
1598=pod
1599
1600We then determine what the console should be on various systems:
1601
1602=over 4
1603
1604=item * Cygwin - We use C<stdin> instead of a separate device.
1605
1606=cut
1607
e22ea7cc
RF
1608 if ( $^O eq 'cygwin' ) {
1609
69893cff
RGS
1610 # /dev/tty is binary. use stdin for textmode
1611 undef $console;
1612 }
1613
1614=item * Unix - use C</dev/tty>.
1615
1616=cut
1617
e22ea7cc 1618 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1619 $console = "/dev/tty";
1620 }
1621
1622=item * Windows or MSDOS - use C<con>.
1623
1624=cut
1625
e22ea7cc 1626 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1627 $console = "con";
1628 }
1629
1630=item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
be9a9b1d
AT
1631Console> if not.
1632
1633Note that Mac OS X returns C<darwin>, not C<MacOS>. Also note that the debugger doesn't do anything special for C<darwin>. Maybe it should.
69893cff
RGS
1634
1635=cut
1636
e22ea7cc
RF
1637 elsif ( $^O eq 'MacOS' ) {
1638 if ( $MacPerl::Version !~ /MPW/ ) {
1639 $console =
1640 "Dev:Console:Perl Debug"; # Separate window for application
69893cff
RGS
1641 }
1642 else {
1643 $console = "Dev:Console";
1644 }
1645 } ## end elsif ($^O eq 'MacOS')
1646
1647=item * VMS - use C<sys$command>.
1648
1649=cut
1650
1651 else {
e22ea7cc 1652
69893cff
RGS
1653 # everything else is ...
1654 $console = "sys\$command";
d12a4851 1655 }
69893cff
RGS
1656
1657=pod
1658
1659=back
1660
1661Several other systems don't use a specific console. We C<undef $console>
1662for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1663with a slave editor, Epoc).
1664
1665=cut
d12a4851 1666
e22ea7cc
RF
1667 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1668
69893cff 1669 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1670 $console = undef;
1671 }
1672
1673 if ( $^O eq 'NetWare' ) {
d12a4851 1674
69893cff
RGS
1675 # /dev/tty is binary. use stdin for textmode
1676 $console = undef;
1677 }
d12a4851 1678
69893cff
RGS
1679 # In OS/2, we need to use STDIN to get textmode too, even though
1680 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1681 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1682 { # In OS/2
1683 $console = undef;
1684 }
1685
1686 # EPOC also falls into the 'got to use STDIN' camp.
1687 if ( $^O eq 'epoc' ) {
1688 $console = undef;
1689 }
d12a4851 1690
69893cff
RGS
1691=pod
1692
1693If there is a TTY hanging around from a parent, we use that as the console.
1694
1695=cut
1696
e22ea7cc 1697 $console = $tty if defined $tty;
d12a4851 1698
69893cff
RGS
1699=head2 SOCKET HANDLING
1700
1701The debugger is capable of opening a socket and carrying out a debugging
1702session over the socket.
1703
1704If C<RemotePort> was defined in the options, the debugger assumes that it
1705should try to start a debugging session on that port. It builds the socket
1706and then tries to connect the input and output filehandles to it.
1707
1708=cut
1709
1710 # Handle socket stuff.
e22ea7cc
RF
1711
1712 if ( defined $remoteport ) {
1713
69893cff
RGS
1714 # If RemotePort was defined in the options, connect input and output
1715 # to the socket.
e22ea7cc
RF
1716 require IO::Socket;
1717 $OUT = new IO::Socket::INET(
1718 Timeout => '10',
1719 PeerAddr => $remoteport,
1720 Proto => 'tcp',
69893cff 1721 );
e22ea7cc
RF
1722 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1723 $IN = $OUT;
69893cff
RGS
1724 } ## end if (defined $remoteport)
1725
1726=pod
1727
1728If no C<RemotePort> was defined, and we want to create a TTY on startup,
1729this is probably a situation where multiple debuggers are running (for example,
1730a backticked command that starts up another debugger). We create a new IN and
1731OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1732and if we can.
1733
1734=cut
1735
1736 # Non-socket.
1737 else {
e22ea7cc 1738
69893cff
RGS
1739 # Two debuggers running (probably a system or a backtick that invokes
1740 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1741 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1742 # know how, and we can.
e22ea7cc
RF
1743 create_IN_OUT(4) if $CreateTTY & 4;
1744 if ($console) {
1745
69893cff 1746 # If we have a console, check to see if there are separate ins and
cd1191f1 1747 # outs to open. (They are assumed identical if not.)
69893cff 1748
e22ea7cc
RF
1749 my ( $i, $o ) = split /,/, $console;
1750 $o = $i unless defined $o;
69893cff 1751
69893cff 1752 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1753 open( IN, "+<$i" )
1754 || open( IN, "<$i" )
1755 || open( IN, "<&STDIN" );
1756
69893cff
RGS
1757 # read/write/create/clobber out, or write/create/clobber out,
1758 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1759 open( OUT, "+>$o" )
1760 || open( OUT, ">$o" )
1761 || open( OUT, ">&STDERR" )
1762 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1763
1764 } ## end if ($console)
1765 elsif ( not defined $console ) {
1766
1767 # No console. Open STDIN.
1768 open( IN, "<&STDIN" );
1769
1770 # merge with STDERR, or with STDOUT.
1771 open( OUT, ">&STDERR" )
1772 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1773 $console = 'STDIN/OUT';
69893cff
RGS
1774 } ## end elsif (not defined $console)
1775
1776 # Keep copies of the filehandles so that when the pager runs, it
1777 # can close standard input without clobbering ours.
e22ea7cc
RF
1778 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1779 } ## end elsif (from if(defined $remoteport))
1780
1781 # Unbuffer DB::OUT. We need to see responses right away.
1782 my $previous = select($OUT);
1783 $| = 1; # for DB::OUT
1784 select($previous);
1785
1786 # Line info goes to debugger output unless pointed elsewhere.
1787 # Pointing elsewhere makes it possible for slave editors to
1788 # keep track of file and position. We have both a filehandle
1789 # and a I/O description to keep track of.
1790 $LINEINFO = $OUT unless defined $LINEINFO;
1791 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1
RGS
1792 # share($LINEINFO); # <- unable to share globs
1793 share($lineinfo); #
e22ea7cc 1794
69893cff
RGS
1795=pod
1796
1797To finish initialization, we show the debugger greeting,
1798and then call the C<afterinit()> subroutine if there is one.
1799
1800=cut
d12a4851 1801
e22ea7cc
RF
1802 # Show the debugger greeting.
1803 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1804 unless ($runnonstop) {
1805 local $\ = '';
1806 local $, = '';
1807 if ( $term_pid eq '-1' ) {
1808 print $OUT "\nDaughter DB session started...\n";
1809 }
1810 else {
1811 print $OUT "\nLoading DB routines from $header\n";
1812 print $OUT (
1813 "Editor support ",
1814 $slave_editor ? "enabled" : "available", ".\n"
1815 );
1816 print $OUT
69893cff
RGS
1817"\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1818 } ## end else [ if ($term_pid eq '-1')
1819 } ## end unless ($runnonstop)
1820} ## end else [ if ($notty)
1821
1822# XXX This looks like a bug to me.
1823# Why copy to @ARGS and then futz with @args?
d338d6fe 1824@ARGS = @ARGV;
1825for (@args) {
69893cff
RGS
1826 # Make sure backslashes before single quotes are stripped out, and
1827 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1828 # s/\'/\\\'/g; # removed while not justified understandably
1829 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
d338d6fe 1830}
1831
e22ea7cc 1832# If there was an afterinit() sub defined, call it. It will get
69893cff 1833# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1834if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1835 &afterinit();
d338d6fe 1836}
e22ea7cc 1837
69893cff 1838# Inform us about "Stack dump during die enabled ..." in dieLevel().
43aed9ee
IZ
1839$I_m_init = 1;
1840
d338d6fe 1841############################################################ Subroutines
1842
69893cff
RGS
1843=head1 SUBROUTINES
1844
1845=head2 DB
1846
1847This gigantic subroutine is the heart of the debugger. Called before every
1848statement, its job is to determine if a breakpoint has been reached, and
1849stop if so; read commands from the user, parse them, and execute
1850them, and hen send execution off to the next statement.
1851
1852Note that the order in which the commands are processed is very important;
1853some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1854to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1855but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1856see what's happening in any given command.
1857
1858=cut
1859
d338d6fe 1860sub DB {
69893cff 1861
2cbb2ee1
RGS
1862 # lock the debugger and get the thread id for the prompt
1863 lock($DBGR);
1864 my $tid;
1865 if ($ENV{PERL5DB_THREADED}) {
878090d5 1866 $tid = eval { "[".threads->tid."]" };
2cbb2ee1
RGS
1867 }
1868
69893cff 1869 # Check for whether we should be running continuously or not.
36477c24 1870 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1871 if ( $single and not $second_time++ ) {
1872
69893cff 1873 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1874 if ($runnonstop) { # Disable until signal
1875 # If there's any call stack in place, turn off single
1876 # stepping into subs throughout the stack.
1877 for ( $i = 0 ; $i <= $stack_depth ; ) {
1878 $stack[ $i++ ] &= ~1;
1879 }
1880
69893cff 1881 # And we are now no longer in single-step mode.
e22ea7cc 1882 $single = 0;
69893cff
RGS
1883
1884 # If we simply returned at this point, we wouldn't get
1885 # the trace info. Fall on through.
e22ea7cc 1886 # return;
69893cff
RGS
1887 } ## end if ($runnonstop)
1888
e22ea7cc
RF
1889 elsif ($ImmediateStop) {
1890
1891 # We are supposed to stop here; XXX probably a break.
1892 $ImmediateStop = 0; # We've processed it; turn it off
1893 $signal = 1; # Simulate an interrupt to force
1894 # us into the command loop
69893cff
RGS
1895 }
1896 } ## end if ($single and not $second_time...
1897
1898 # If we're in single-step mode, or an interrupt (real or fake)
1899 # has occurred, turn off non-stop mode.
1900 $runnonstop = 0 if $single or $signal;
1901
1902 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1903 # The code being debugged may have altered them.
d338d6fe 1904 &save;
69893cff
RGS
1905
1906 # Since DB::DB gets called after every line, we can use caller() to
1907 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1908 # caller is returning all the extra information when called from the
69893cff 1909 # debugger.
e22ea7cc 1910 local ( $package, $filename, $line ) = caller;
471505cc 1911 local $filename_ini = $filename;
69893cff
RGS
1912
1913 # set up the context for DB::eval, so it can properly execute
1914 # code on behalf of the user. We add the package in so that the
1915 # code is eval'ed in the proper package (not in the debugger!).
1916 local $usercontext =
e22ea7cc 1917 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
69893cff
RGS
1918
1919 # Create an alias to the active file magical array to simplify
1920 # the code here.
e22ea7cc 1921 local (*dbline) = $main::{ '_<' . $filename };
aa057b67
CN
1922
1923 # we need to check for pseudofiles on Mac OS (these are files
1924 # not attached to a filename, but instead stored in Dev:Pseudo)
e22ea7cc
RF
1925 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1926 $filename_ini = $filename = 'Dev:Pseudo';
1927 *dbline = $main::{ '_<' . $filename };
aa057b67
CN
1928 }
1929
69893cff 1930 # Last line in the program.
471505cc 1931 local $max = $#dbline;
69893cff
RGS
1932
1933 # if we have something here, see if we should break.
e22ea7cc
RF
1934 if ( $dbline{$line}
1935 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1936 {
1937
69893cff 1938 # Stop if the stop criterion says to just stop.
e22ea7cc 1939 if ( $stop eq '1' ) {
69893cff
RGS
1940 $signal |= 1;
1941 }
e22ea7cc 1942
69893cff
RGS
1943 # It's a conditional stop; eval it in the user's context and
1944 # see if we should stop. If so, remove the one-time sigil.
1945 elsif ($stop) {
e22ea7cc 1946 $evalarg = "\$DB::signal |= 1 if do {$stop}";
69893cff
RGS
1947 &eval;
1948 $dbline{$line} =~ s/;9($|\0)/$1/;
1949 }
1950 } ## end if ($dbline{$line} && ...
1951
1952 # Preserve the current stop-or-not, and see if any of the W
1953 # (watch expressions) has changed.
36477c24 1954 my $was_signal = $signal;
69893cff
RGS
1955
1956 # If we have any watch expressions ...
e22ea7cc
RF
1957 if ( $trace & 2 ) {
1958 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1959 $evalarg = $to_watch[$n];
1960 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1961
1962 # Fix context DB::eval() wants to return an array, but
1963 # we need a scalar here.
e22ea7cc
RF
1964 my ($val) = join( "', '", &eval );
1965 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1966
1967 # Did it change?
e22ea7cc
RF
1968 if ( $val ne $old_watch[$n] ) {
1969
69893cff 1970 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1971 $signal = 1;
1972 print $OUT <<EOP;
405ff068 1973Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1974 old value:\t$old_watch[$n]
1975 new value:\t$val
6027b9a3 1976EOP
e22ea7cc 1977 $old_watch[$n] = $val;
69893cff
RGS
1978 } ## end if ($val ne $old_watch...
1979 } ## end for (my $n = 0 ; $n <= ...
1980 } ## end if ($trace & 2)
1981
1982=head2 C<watchfunction()>
1983
1984C<watchfunction()> is a function that can be defined by the user; it is a
1985function which will be run on each entry to C<DB::DB>; it gets the
1986current package, filename, and line as its parameters.
1987
1988The watchfunction can do anything it likes; it is executing in the
1989debugger's context, so it has access to all of the debugger's internal
1990data structures and functions.
1991
1992C<watchfunction()> can control the debugger's actions. Any of the following
1993will cause the debugger to return control to the user's program after
1994C<watchfunction()> executes:
1995
1996=over 4
1997
be9a9b1d
AT
1998=item *
1999
2000Returning a false value from the C<watchfunction()> itself.
2001
2002=item *
2003
2004Altering C<$single> to a false value.
2005
2006=item *
69893cff 2007
be9a9b1d 2008Altering C<$signal> to a false value.
69893cff 2009
be9a9b1d 2010=item *
69893cff 2011
be9a9b1d 2012Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2013check for C<watchfunction()>. This can be done with
2014
2015 $trace &= ~4;
2016
2017=back
2018
2019=cut
2020
e22ea7cc 2021 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2022 # current package, filename, and line. The function executes in
2023 # the DB:: package.
e22ea7cc
RF
2024 if ( $trace & 4 ) { # User-installed watch
2025 return
2026 if watchfunction( $package, $filename, $line )
2027 and not $single
2028 and not $was_signal
2029 and not( $trace & ~4 );
69893cff
RGS
2030 } ## end if ($trace & 4)
2031
e22ea7cc 2032 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2033 # turn off the signal now.
6027b9a3 2034 $was_signal = $signal;
69893cff
RGS
2035 $signal = 0;
2036
2037=head2 GETTING READY TO EXECUTE COMMANDS
2038
2039The debugger decides to take control if single-step mode is on, the
2040C<t> command was entered, or the user generated a signal. If the program
2041has fallen off the end, we set things up so that entering further commands
2042won't cause trouble, and we say that the program is over.
2043
2044=cut
2045
2046 # Check to see if we should grab control ($single true,
2047 # trace set appropriately, or we got a signal).
e22ea7cc
RF
2048 if ( $single || ( $trace & 1 ) || $was_signal ) {
2049
69893cff 2050 # Yes, grab control.
e22ea7cc
RF
2051 if ($slave_editor) {
2052
69893cff 2053 # Tell the editor to update its position.
e22ea7cc
RF
2054 $position = "\032\032$filename:$line:0\n";
2055 print_lineinfo($position);
2056 }
69893cff
RGS
2057
2058=pod
2059
2060Special check: if we're in package C<DB::fake>, we've gone through the
2061C<END> block at least once. We set up everything so that we can continue
2062to enter commands and have a valid context to be in.
2063
2064=cut
2065
e22ea7cc 2066 elsif ( $package eq 'DB::fake' ) {
69893cff 2067
69893cff 2068 # Fallen off the end already.
e22ea7cc
RF
2069 $term || &setterm;
2070 print_help(<<EOP);
405ff068 2071Debugged program terminated. Use B<q> to quit or B<R> to restart,
6b27b0a0
BD
2072 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2073 B<h q>, B<h R> or B<h o> to get additional info.
405ff068 2074EOP
e22ea7cc 2075
69893cff 2076 # Set the DB::eval context appropriately.
e22ea7cc
RF
2077 $package = 'main';
2078 $usercontext =
2079 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2080 . "package $package;"; # this won't let them modify, alas
69893cff 2081 } ## end elsif ($package eq 'DB::fake')
e219e2fb 2082
69893cff 2083=pod
e219e2fb 2084
69893cff
RGS
2085If the program hasn't finished executing, we scan forward to the
2086next executable line, print that out, build the prompt from the file and line
2087number information, and print that.
e219e2fb 2088
69893cff
RGS
2089=cut
2090
e22ea7cc
RF
2091 else {
2092
69893cff
RGS
2093 # Still somewhere in the midst of execution. Set up the
2094 # debugger prompt.
2095 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 2096 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
2097 #module names)
2098
e22ea7cc
RF
2099 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2100 $prefix .= "$sub($filename:";
2101 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2102
2103 # Break up the prompt if it's really long.
e22ea7cc
RF
2104 if ( length($prefix) > 30 ) {
2105 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2106 $prefix = "";
2107 $infix = ":\t";
2108 }
2109 else {
2110 $infix = "):\t";
2111 $position = "$prefix$line$infix$dbline[$line]$after";
2112 }
69893cff
RGS
2113
2114 # Print current line info, indenting if necessary.
e22ea7cc
RF
2115 if ($frame) {
2116 print_lineinfo( ' ' x $stack_depth,
2117 "$line:\t$dbline[$line]$after" );
2118 }
2119 else {
2120 print_lineinfo($position);
2121 }
69893cff
RGS
2122
2123 # Scan forward, stopping at either the end or the next
2124 # unbreakable line.
e22ea7cc
RF
2125 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2126 { #{ vi
69893cff
RGS
2127
2128 # Drop out on null statements, block closers, and comments.
2129 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2130
2131 # Drop out if the user interrupted us.
2132 last if $signal;
2133
2134 # Append a newline if the line doesn't have one. Can happen
2135 # in eval'ed text, for instance.
e22ea7cc 2136 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2137
2138 # Next executable line.
2139 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2140 $position .= $incr_pos;
2141 if ($frame) {
e22ea7cc 2142
69893cff 2143 # Print it indented if tracing is on.
e22ea7cc
RF
2144 print_lineinfo( ' ' x $stack_depth,
2145 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2146 }
2147 else {
2148 print_lineinfo($incr_pos);
2149 }
2150 } ## end for ($i = $line + 1 ; $i...
2151 } ## end else [ if ($slave_editor)
2152 } ## end if ($single || ($trace...
2153
2154=pod
2155
2156If there's an action to be executed for the line we stopped at, execute it.
2157If there are any preprompt actions, execute those as well.
e219e2fb
RF
2158
2159=cut
2160
69893cff
RGS
2161 # If there's an action, do it now.
2162 $evalarg = $action, &eval if $action;
e219e2fb 2163
69893cff
RGS
2164 # Are we nested another level (e.g., did we evaluate a function
2165 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2166 if ( $single || $was_signal ) {
2167
69893cff 2168 # Yes, go down a level.
e22ea7cc 2169 local $level = $level + 1;
69893cff
RGS
2170
2171 # Do any pre-prompt actions.
e22ea7cc
RF
2172 foreach $evalarg (@$pre) {
2173 &eval;
2174 }
69893cff
RGS
2175
2176 # Complain about too much recursion if we passed the limit.
e22ea7cc 2177 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2178 if $single & 4;
2179
2180 # The line we're currently on. Set $incr to -1 to stay here
2181 # until we get a command that tells us to advance.
e22ea7cc
RF
2182 $start = $line;
2183 $incr = -1; # for backward motion.
69893cff
RGS
2184
2185 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2186 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2187
2188=head2 WHERE ARE WE?
2189
2190XXX Relocate this section?
2191
2192The debugger normally shows the line corresponding to the current line of
2193execution. Sometimes, though, we want to see the next line, or to move elsewhere
2194in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2195
be9a9b1d
AT
2196C<$incr> controls by how many lines the I<current> line should move forward
2197after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2198line shouldn't change.
2199
be9a9b1d 2200C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2201move forwards or backwards from when doing an C<L> or C<-> command.
2202
2203C<$max> tells the debugger where the last line of the current file is. It's
2204used to terminate loops most often.
2205
2206=head2 THE COMMAND LOOP
2207
2208Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2209in two parts:
2210
2211=over 4
2212
be9a9b1d
AT
2213=item *
2214
2215The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2216reads a command and then executes it.
2217
be9a9b1d
AT
2218=item *
2219
2220The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2221is wholly contained inside the C<CMD> block and only executes a command.
2222Used to handle commands running inside a pager.
2223
2224=back
2225
2226So why have two labels to restart the loop? Because sometimes, it's easier to
2227have a command I<generate> another command and then re-execute the loop to do
2228the new command. This is faster, but perhaps a bit more convoluted.
2229
2230=cut
2231
2232 # The big command dispatch loop. It keeps running until the
2233 # user yields up control again.
2234 #
2235 # If we have a terminal for input, and we get something back
2236 # from readline(), keep on processing.
e22ea7cc
RF
2237 CMD:
2238 while (
2239
69893cff 2240 # We have a terminal, or can get one ...
e22ea7cc
RF
2241 ( $term || &setterm ),
2242
69893cff 2243 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2244 ( $term_pid == $$ or resetterm(1) ),
2245
69893cff 2246 # ... and we got a line of command input ...
e22ea7cc
RF
2247 defined(
2248 $cmd = &readline(
2cbb2ee1 2249 "$pidprompt $tid DB"
e22ea7cc
RF
2250 . ( '<' x $level )
2251 . ( $#hist + 1 )
2252 . ( '>' x $level ) . " "
69893cff
RGS
2253 )
2254 )
2255 )
2256 {
e22ea7cc 2257
2cbb2ee1 2258 share($cmd);
69893cff
RGS
2259 # ... try to execute the input as debugger commands.
2260
2261 # Don't stop running.
2262 $single = 0;
2263
2264 # No signal is active.
2265 $signal = 0;
2266
2267 # Handle continued commands (ending with \):
e22ea7cc
RF
2268 $cmd =~ s/\\$/\n/ && do {
2269 $cmd .= &readline(" cont: ");
2270 redo CMD;
2271 };
69893cff
RGS
2272
2273=head4 The null command
2274
be9a9b1d 2275A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2276command out of C<$laststep> (where it was recorded previously), and copy it
2277back into C<$cmd> to be executed below. If there wasn't any previous command,
2278we'll do nothing below (no command will match). If there was, we also save it
2279in the command history and fall through to allow the command parsing to pick
2280it up.
2281
2282=cut
2283
2284 # Empty input means repeat the last command.
e22ea7cc
RF
2285 $cmd =~ /^$/ && ( $cmd = $laststep );
2286 chomp($cmd); # get rid of the annoying extra newline
2287 push( @hist, $cmd ) if length($cmd) > 1;
2288 push( @truehist, $cmd );
2cbb2ee1
RGS
2289 share(@hist);
2290 share(@truehist);
e22ea7cc
RF
2291
2292 # This is a restart point for commands that didn't arrive
2293 # via direct user input. It allows us to 'redo PIPE' to
2294 # re-execute command processing without reading a new command.
69893cff 2295 PIPE: {
e22ea7cc
RF
2296 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2297 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2298 ($i) = split( /\s+/, $cmd );
69893cff
RGS
2299
2300=head3 COMMAND ALIASES
2301
2302The debugger can create aliases for commands (these are stored in the
2303C<%alias> hash). Before a command is executed, the command loop looks it up
2304in the alias hash and substitutes the contents of the alias for the command,
2305completely replacing it.
2306
2307=cut
2308
2309 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2310 if ( $alias{$i} ) {
2311
69893cff
RGS
2312 # Squelch signal handling; we want to keep control here
2313 # if something goes loco during the alias eval.
2314 local $SIG{__DIE__};
2315 local $SIG{__WARN__};
2316
2317 # This is a command, so we eval it in the DEBUGGER's
2318 # scope! Otherwise, we can't see the special debugger
2319 # variables, or get to the debugger's subs. (Well, we
2320 # _could_, but why make it even more complicated?)
2321 eval "\$cmd =~ $alias{$i}";
2322 if ($@) {
2323 local $\ = '';
2324 print $OUT "Couldn't evaluate `$i' alias: $@";
2325 next CMD;
2326 }
2327 } ## end if ($alias{$i})
2328
2329=head3 MAIN-LINE COMMANDS
2330
2331All of these commands work up to and after the program being debugged has
2332terminated.
2333
2334=head4 C<q> - quit
2335
2336Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2337try to execute further, cleaning any restart-related stuff out of the
2338environment, and executing with the last value of C<$?>.
2339
2340=cut
2341
2342 $cmd =~ /^q$/ && do {
2343 $fall_off_end = 1;
2344 clean_ENV();
2345 exit $?;
2346 };
2347
2348=head4 C<t> - trace
2349
2350Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2351
2352=cut
2353
e22ea7cc
RF
2354 $cmd =~ /^t$/ && do {
2355 $trace ^= 1;
2356 local $\ = '';
2357 print $OUT "Trace = "
2358 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2359 next CMD;
2360 };
69893cff
RGS
2361
2362=head4 C<S> - list subroutines matching/not matching a pattern
2363
2364Walks through C<%sub>, checking to see whether or not to print the name.
2365
2366=cut
2367
e22ea7cc 2368 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
69893cff 2369
e22ea7cc 2370 $Srev = defined $2; # Reverse scan?
69893cff
RGS
2371 $Spatt = $3; # The pattern (if any) to use.
2372 $Snocheck = !defined $1; # No args - print all subs.
2373
2374 # Need to make these sane here.
e22ea7cc
RF
2375 local $\ = '';
2376 local $, = '';
69893cff
RGS
2377
2378 # Search through the debugger's magical hash of subs.
2379 # If $nocheck is true, just print the sub name.
2380 # Otherwise, check it against the pattern. We then use
2381 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2382 foreach $subname ( sort( keys %sub ) ) {
2383 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2384 print $OUT $subname, "\n";
2385 }
2386 }
2387 next CMD;
2388 };
69893cff
RGS
2389
2390=head4 C<X> - list variables in current package
2391
2392Since the C<V> command actually processes this, just change this to the
2393appropriate C<V> command and fall through.
2394
2395=cut
2396
e22ea7cc 2397 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2398
2399=head4 C<V> - list variables
2400
2401Uses C<dumpvar.pl> to dump out the current values for selected variables.
2402
2403=cut
2404
2405 # Bare V commands get the currently-being-debugged package
2406 # added.
e22ea7cc
RF
2407 $cmd =~ /^V$/ && do {
2408 $cmd = "V $package";
2409 };
69893cff
RGS
2410
2411 # V - show variables in package.
2412 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
e22ea7cc 2413
69893cff
RGS
2414 # Save the currently selected filehandle and
2415 # force output to debugger's filehandle (dumpvar
2416 # just does "print" for output).
e22ea7cc 2417 local ($savout) = select($OUT);
69893cff
RGS
2418
2419 # Grab package name and variables to dump.
e22ea7cc
RF
2420 $packname = $1;
2421 @vars = split( ' ', $2 );
69893cff
RGS
2422
2423 # If main::dumpvar isn't here, get it.
e81465be 2424 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2425 if ( defined &main::dumpvar ) {
2426
69893cff
RGS
2427 # We got it. Turn off subroutine entry/exit messages
2428 # for the moment, along with return values.
e22ea7cc
RF
2429 local $frame = 0;
2430 local $doret = -2;
69893cff
RGS
2431
2432 # must detect sigpipe failures - not catching
2433 # then will cause the debugger to die.
2434 eval {
2435 &main::dumpvar(
2436 $packname,
2437 defined $option{dumpDepth}
e22ea7cc
RF
2438 ? $option{dumpDepth}
2439 : -1, # assume -1 unless specified
69893cff 2440 @vars
e22ea7cc
RF
2441 );
2442 };
2443
2444 # The die doesn't need to include the $@, because
2445 # it will automatically get propagated for us.
2446 if ($@) {
2447 die unless $@ =~ /dumpvar print failed/;
2448 }
2449 } ## end if (defined &main::dumpvar)
2450 else {
2451
2452 # Couldn't load dumpvar.
2453 print $OUT "dumpvar.pl not available.\n";
2454 }
69893cff 2455
69893cff 2456 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2457 select($savout);
2458 next CMD;
2459 };
69893cff
RGS
2460
2461=head4 C<x> - evaluate and print an expression
2462
2463Hands the expression off to C<DB::eval>, setting it up to print the value
2464via C<dumpvar.pl> instead of just printing it directly.
2465
2466=cut
2467
e22ea7cc
RF
2468 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2469 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2470
2471 # handle special "x 3 blah" syntax XXX propagate
2472 # doc back to special variables.
e22ea7cc
RF
2473 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2474 $onetimedumpDepth = $1;
2475 }
2476 };
69893cff
RGS
2477
2478=head4 C<m> - print methods
2479
2480Just uses C<DB::methods> to determine what methods are available.
2481
2482=cut
2483
e22ea7cc
RF
2484 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2485 methods($1);
2486 next CMD;
2487 };
69893cff
RGS
2488
2489 # m expr - set up DB::eval to do the work
e22ea7cc
RF
2490 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2491 $onetimeDump = 'methods'; # method output gets used there
2492 };
69893cff
RGS
2493
2494=head4 C<f> - switch files
2495
2496=cut
2497
e22ea7cc
RF
2498 $cmd =~ /^f\b\s*(.*)/ && do {
2499 $file = $1;
2500 $file =~ s/\s+$//;
69893cff
RGS
2501
2502 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2503 if ( !$file ) {
2504 print $OUT
2505 "The old f command is now the r command.\n"; # hint
2506 print $OUT "The new f command switches filenames.\n";
2507 next CMD;
2508 } ## end if (!$file)
69893cff
RGS
2509
2510 # if not in magic file list, try a close match.
e22ea7cc
RF
2511 if ( !defined $main::{ '_<' . $file } ) {
2512 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2513 {
2514 $try = substr( $try, 2 );
2515 print $OUT "Choosing $try matching `$file':\n";
2516 $file = $try;
2517 }
2518 } ## end if (($try) = grep(m#^_<.*$file#...
2519 } ## end if (!defined $main::{ ...
69893cff
RGS
2520
2521 # If not successfully switched now, we failed.
e22ea7cc
RF
2522 if ( !defined $main::{ '_<' . $file } ) {
2523 print $OUT "No file matching `$file' is loaded.\n";
2524 next CMD;
2525 }
69893cff 2526
e22ea7cc
RF
2527 # We switched, so switch the debugger internals around.
2528 elsif ( $file ne $filename ) {
2529 *dbline = $main::{ '_<' . $file };
2530 $max = $#dbline;
2531 $filename = $file;
2532 $start = 1;
2533 $cmd = "l";
2534 } ## end elsif ($file ne $filename)
2535
2536 # We didn't switch; say we didn't.
2537 else {
2538 print $OUT "Already in $file.\n";
2539 next CMD;
2540 }
2541 };
69893cff
RGS
2542
2543=head4 C<.> - return to last-executed line.
2544
2545We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2546and then we look up the line in the magical C<%dbline> hash.
2547
2548=cut
2549
2550 # . command.
e22ea7cc
RF
2551 $cmd =~ /^\.$/ && do {
2552 $incr = -1; # stay at current line
69893cff
RGS
2553
2554 # Reset everything to the old location.
e22ea7cc
RF
2555 $start = $line;
2556 $filename = $filename_ini;
2557 *dbline = $main::{ '_<' . $filename };
2558 $max = $#dbline;
69893cff
RGS
2559
2560 # Now where are we?
e22ea7cc
RF
2561 print_lineinfo($position);
2562 next CMD;
2563 };
69893cff
RGS
2564
2565=head4 C<-> - back one window
2566
2567We change C<$start> to be one window back; if we go back past the first line,
2568we set it to be the first line. We ser C<$incr> to put us back at the
2569currently-executing line, and then put a C<l $start +> (list one window from
2570C<$start>) in C<$cmd> to be executed later.
2571
2572=cut
2573
2574 # - - back a window.
e22ea7cc
RF
2575 $cmd =~ /^-$/ && do {
2576
69893cff 2577 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2578 $start -= $incr + $window + 1;
2579 $start = 1 if $start <= 0;
2580 $incr = $window - 1;
69893cff
RGS
2581
2582 # Generate and execute a "l +" command (handled below).
e22ea7cc
RF
2583 $cmd = 'l ' . ($start) . '+';
2584 };
69893cff
RGS
2585
2586=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>, {, {{>
2587
2588In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2589problems, most notably that the default case of several commands destroying
2590the user's work in setting watchpoints, actions, etc. We wanted, however, to
2591retain the old commands for those who were used to using them or who preferred
2592them. At this point, we check for the new commands and call C<cmd_wrapper> to
2593deal with them instead of processing them in-line.
2594
2595=cut
2596
2597 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2598 # we send them off to the secondary dispatcher (see below).
2cbb2ee1 2599 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
e22ea7cc
RF
2600 &cmd_wrapper( $1, $2, $line );
2601 next CMD;
2602 };
69893cff
RGS
2603
2604=head4 C<y> - List lexicals in higher scope
2605
2606Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2607above the current one and then displays then using C<dumpvar.pl>.
2608
2609=cut
2610
2611 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2612
2613 # See if we've got the necessary support.
2614 eval { require PadWalker; PadWalker->VERSION(0.08) }
2615 or &warn(
2616 $@ =~ /locate/
2617 ? "PadWalker module not found - please install\n"
2618 : $@
2619 )
2620 and next CMD;
2621
2622 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2623 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2624 defined &main::dumpvar
2625 or print $OUT "dumpvar.pl not available.\n"
2626 and next CMD;
2627
2628 # Got all the modules we need. Find them and print them.
e22ea7cc 2629 my @vars = split( ' ', $2 || '' );
69893cff
RGS
2630
2631 # Find the pad.
e22ea7cc 2632 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
69893cff
RGS
2633
2634 # Oops. Can't find it.
2635 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2636
2637 # Show the desired vars with dumplex().
2638 my $savout = select($OUT);
2639
2640 # Have dumplex dump the lexicals.
e22ea7cc 2641 dumpvar::dumplex( $_, $h->{$_},
69893cff 2642 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2643 @vars )
2644 for sort keys %$h;
69893cff
RGS
2645 select($savout);
2646 next CMD;
2647 };
2648
2649=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2650
2651All of the commands below this point don't work after the program being
2652debugged has ended. All of them check to see if the program has ended; this
2653allows the commands to be relocated without worrying about a 'line of
2654demarcation' above which commands can be entered anytime, and below which
2655they can't.
2656
2657=head4 C<n> - single step, but don't trace down into subs
2658
2659Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2660when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
69893cff
RGS
2661so a null command knows what to re-execute.
2662
2663=cut
2664
e22ea7cc 2665 # n - next
69893cff
RGS
2666 $cmd =~ /^n$/ && do {
2667 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2668
69893cff
RGS
2669 # Single step, but don't enter subs.
2670 $single = 2;
e22ea7cc 2671
69893cff 2672 # Save for empty command (repeat last).
e22ea7cc
RF
2673 $laststep = $cmd;
2674 last CMD;
2675 };
69893cff
RGS
2676
2677=head4 C<s> - single-step, entering subs
2678
be9a9b1d 2679Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2680subs. Also saves C<s> as C<$lastcmd>.
2681
2682=cut
2683
2684 # s - single step.
2685 $cmd =~ /^s$/ && do {
e22ea7cc 2686
69893cff
RGS
2687 # Get out and restart the command loop if program
2688 # has finished.
e22ea7cc
RF
2689 end_report(), next CMD if $finished and $level <= 1;
2690
69893cff 2691 # Single step should enter subs.
e22ea7cc
RF
2692 $single = 1;
2693
69893cff 2694 # Save for empty command (repeat last).
e22ea7cc
RF
2695 $laststep = $cmd;
2696 last CMD;
2697 };
69893cff
RGS
2698
2699=head4 C<c> - run continuously, setting an optional breakpoint
2700
2701Most of the code for this command is taken up with locating the optional
2702breakpoint, which is either a subroutine name or a line number. We set
2703the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2704in this and all call levels above this one.
2705
2706=cut
2707
2708 # c - start continuous execution.
2709 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
e22ea7cc 2710
69893cff
RGS
2711 # Hey, show's over. The debugged program finished
2712 # executing already.
2713 end_report(), next CMD if $finished and $level <= 1;
2714
2715 # Capture the place to put a one-time break.
2716 $subname = $i = $1;
2717
e22ea7cc
RF
2718 # Probably not needed, since we finish an interactive
2719 # sub-session anyway...
2720 # local $filename = $filename;
2721 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2722 #
2723 # The above question wonders if localizing the alias
2724 # to the magic array works or not. Since it's commented
2725 # out, we'll just leave that to speculation for now.
2726
2727 # If the "subname" isn't all digits, we'll assume it
2728 # is a subroutine name, and try to find it.
e22ea7cc
RF
2729 if ( $subname =~ /\D/ ) { # subroutine name
2730 # Qualify it to the current package unless it's
2731 # already qualified.
69893cff
RGS
2732 $subname = $package . "::" . $subname
2733 unless $subname =~ /::/;
e22ea7cc 2734
69893cff
RGS
2735 # find_sub will return "file:line_number" corresponding
2736 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2737 # break up the return value, and assign it in one
69893cff 2738 # operation.
e22ea7cc 2739 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2740
2741 # Force the line number to be numeric.
e22ea7cc 2742 $i += 0;
69893cff
RGS
2743
2744 # If we got a line number, we found the sub.
e22ea7cc
RF
2745 if ($i) {
2746
69893cff
RGS
2747 # Switch all the debugger's internals around so
2748 # we're actually working with that file.
e22ea7cc
RF
2749 $filename = $file;
2750 *dbline = $main::{ '_<' . $filename };
2751
69893cff 2752 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2753 $had_breakpoints{$filename} |= 1;
2754
69893cff
RGS
2755 # Scan forward to the first executable line
2756 # after the 'sub whatever' line.
e22ea7cc
RF
2757 $max = $#dbline;
2758 ++$i while $dbline[$i] == 0 && $i < $max;
2759 } ## end if ($i)
69893cff
RGS
2760
2761 # We didn't find a sub by that name.
e22ea7cc
RF
2762 else {
2763 print $OUT "Subroutine $subname not found.\n";
2764 next CMD;
2765 }
2766 } ## end if ($subname =~ /\D/)
69893cff
RGS
2767
2768 # At this point, either the subname was all digits (an
2769 # absolute line-break request) or we've scanned through
2770 # the code following the definition of the sub, looking
2771 # for an executable, which we may or may not have found.
2772 #
2773 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2774 # got a request to break at some line somewhere. On
2775 # one hand, if there wasn't any real subroutine name
2776 # involved, this will be a request to break in the current
2777 # file at the specified line, so we have to check to make
69893cff
RGS
2778 # sure that the line specified really is breakable.
2779 #
2780 # On the other hand, if there was a subname supplied, the
3c4b39be 2781 # preceding block has moved us to the proper file and
69893cff
RGS
2782 # location within that file, and then scanned forward
2783 # looking for the next executable line. We have to make
2784 # sure that one was found.
2785 #
2786 # On the gripping hand, we can't do anything unless the
2787 # current value of $i points to a valid breakable line.
2788 # Check that.
e22ea7cc
RF
2789 if ($i) {
2790
69893cff 2791 # Breakable?
e22ea7cc
RF
2792 if ( $dbline[$i] == 0 ) {
2793 print $OUT "Line $i not breakable.\n";
2794 next CMD;
2795 }
2796
69893cff 2797 # Yes. Set up the one-time-break sigil.
e22ea7cc
RF
2798 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2799 } ## end if ($i)
69893cff
RGS
2800
2801 # Turn off stack tracing from here up.
e22ea7cc
RF
2802 for ( $i = 0 ; $i <= $stack_depth ; ) {
2803 $stack[ $i++ ] &= ~1;
2804 }
2805 last CMD;
2806 };
69893cff
RGS
2807
2808=head4 C<r> - return from a subroutine
2809
2810For C<r> to work properly, the debugger has to stop execution again
2811immediately after the return is executed. This is done by forcing
2812single-stepping to be on in the call level above the current one. If
2813we are printing return values when a C<r> is executed, set C<$doret>
2814appropriately, and force us out of the command loop.
2815
2816=cut
2817
2818 # r - return from the current subroutine.
e22ea7cc
RF
2819 $cmd =~ /^r$/ && do {
2820
69893cff 2821 # Can't do anythign if the program's over.
e22ea7cc
RF
2822 end_report(), next CMD if $finished and $level <= 1;
2823
69893cff 2824 # Turn on stack trace.
e22ea7cc
RF
2825 $stack[$stack_depth] |= 1;
2826
69893cff 2827 # Print return value unless the stack is empty.
e22ea7cc
RF
2828 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2829 last CMD;
2830 };
69893cff 2831
69893cff
RGS
2832=head4 C<T> - stack trace
2833
2834Just calls C<DB::print_trace>.
2835
2836=cut
2837
e22ea7cc
RF
2838 $cmd =~ /^T$/ && do {
2839 print_trace( $OUT, 1 ); # skip DB
2840 next CMD;
2841 };
69893cff
RGS
2842
2843=head4 C<w> - List window around current line.
2844
2845Just calls C<DB::cmd_w>.
2846
2847=cut
2848
e22ea7cc 2849 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
69893cff
RGS
2850
2851=head4 C<W> - watch-expression processing.
2852
2853Just calls C<DB::cmd_W>.
2854
2855=cut
2856
e22ea7cc 2857 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
69893cff
RGS
2858
2859=head4 C</> - search forward for a string in the source
2860
2861We take the argument and treat it as a pattern. If it turns out to be a
2862bad one, we return the error we got from trying to C<eval> it and exit.
2863If not, we create some code to do the search and C<eval> it so it can't
2864mess us up.
2865
2866=cut
2867
e22ea7cc 2868 $cmd =~ /^\/(.*)$/ && do {
69893cff
RGS
2869
2870 # The pattern as a string.
e22ea7cc 2871 $inpat = $1;
69893cff
RGS
2872
2873 # Remove the final slash.
e22ea7cc 2874 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2875
2876 # If the pattern isn't null ...
e22ea7cc 2877 if ( $inpat ne "" ) {
69893cff
RGS
2878
2879 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2880 local $SIG{__DIE__};
2881 local $SIG{__WARN__};
69893cff
RGS
2882
2883 # Create the pattern.
e22ea7cc
RF
2884 eval '$inpat =~ m' . "\a$inpat\a";
2885 if ( $@ ne "" ) {
2886
69893cff 2887 # Oops. Bad pattern. No biscuit.
e22ea7cc 2888 # Print the eval error and go back for more
69893cff 2889 # commands.
e22ea7cc
RF
2890 print $OUT "$@";
2891 next CMD;
2892 }
2893 $pat = $inpat;
2894 } ## end if ($inpat ne "")
69893cff
RGS
2895
2896 # Set up to stop on wrap-around.
e22ea7cc 2897 $end = $start;
69893cff
RGS
2898
2899 # Don't move off the current line.
e22ea7cc 2900 $incr = -1;
69893cff
RGS
2901
2902 # Done in eval so nothing breaks if the pattern
2903 # does something weird.
e22ea7cc
RF
2904 eval '
2905 for (;;) {
69893cff 2906 # Move ahead one line.
e22ea7cc 2907 ++$start;
69893cff
RGS
2908
2909 # Wrap if we pass the last line.
e22ea7cc 2910 $start = 1 if ($start > $max);
69893cff
RGS
2911
2912 # Stop if we have gotten back to this line again,
e22ea7cc 2913 last if ($start == $end);
69893cff
RGS
2914
2915 # A hit! (Note, though, that we are doing
2916 # case-insensitive matching. Maybe a qr//
2917 # expression would be better, so the user could
2918 # do case-sensitive matching if desired.
e22ea7cc
RF
2919 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2920 if ($slave_editor) {
69893cff 2921 # Handle proper escaping in the slave.
e22ea7cc
RF
2922 print $OUT "\032\032$filename:$start:0\n";
2923 }
2924 else {
69893cff 2925 # Just print the line normally.
e22ea7cc
RF
2926 print $OUT "$start:\t",$dbline[$start],"\n";
2927 }
69893cff 2928 # And quit since we found something.
e22ea7cc
RF
2929 last;
2930 }
2931 } ';
2932
69893cff 2933 # If we wrapped, there never was a match.
e22ea7cc
RF
2934 print $OUT "/$pat/: not found\n" if ( $start == $end );
2935 next CMD;
2936 };
69893cff
RGS
2937
2938=head4 C<?> - search backward for a string in the source
2939
2940Same as for C</>, except the loop runs backwards.
2941
2942=cut
2943
2944 # ? - backward pattern search.
e22ea7cc 2945 $cmd =~ /^\?(.*)$/ && do {
69893cff
RGS
2946
2947 # Get the pattern, remove trailing question mark.
e22ea7cc
RF
2948 $inpat = $1;
2949 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2950
2951 # If we've got one ...
e22ea7cc 2952 if ( $inpat ne "" ) {
69893cff
RGS
2953
2954 # Turn off die & warn handlers.
e22ea7cc
RF
2955 local $SIG{__DIE__};
2956 local $SIG{__WARN__};
2957 eval '$inpat =~ m' . "\a$inpat\a";
2958
2959 if ( $@ ne "" ) {
2960
69893cff 2961 # Ouch. Not good. Print the error.
e22ea7cc
RF
2962 print $OUT $@;
2963 next CMD;
2964 }
2965 $pat = $inpat;
69893cff 2966 } ## end if ($inpat ne "")
e22ea7cc 2967
69893cff 2968 # Where we are now is where to stop after wraparound.
e22ea7cc 2969 $end = $start;
69893cff
RGS
2970
2971 # Don't move away from this line.
e22ea7cc 2972 $incr = -1;
69893cff
RGS
2973
2974 # Search inside the eval to prevent pattern badness
2975 # from killing us.
e22ea7cc
RF
2976 eval '
2977 for (;;) {
69893cff 2978 # Back up a line.
e22ea7cc 2979 --$start;
69893cff
RGS
2980
2981 # Wrap if we pass the first line.
e22ea7cc
RF
2982
2983 $start = $max if ($start <= 0);
69893cff
RGS
2984
2985 # Quit if we get back where we started,
e22ea7cc 2986 last if ($start == $end);
69893cff
RGS
2987
2988 # Match?
e22ea7cc
RF
2989 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2990 if ($slave_editor) {
69893cff 2991 # Yep, follow slave editor requirements.
e22ea7cc
RF
2992 print $OUT "\032\032$filename:$start:0\n";
2993 }
2994 else {
69893cff 2995 # Yep, just print normally.
e22ea7cc
RF
2996 print $OUT "$start:\t",$dbline[$start],"\n";
2997 }
69893cff
RGS
2998
2999 # Found, so done.
e22ea7cc
RF
3000 last;
3001 }
3002 } ';
3003
3004 # Say we failed if the loop never found anything,
3005 print $OUT "?$pat?: not found\n" if ( $start == $end );
3006 next CMD;
3007 };
69893cff
RGS
3008
3009=head4 C<$rc> - Recall command
3010
3011Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
3012that the terminal supports history). It find the the command required, puts it
3013into C<$cmd>, and redoes the loop to execute it.
3014
3015=cut
3016
e22ea7cc
RF
3017 # $rc - recall command.
3018 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
69893cff
RGS
3019
3020 # No arguments, take one thing off history.
e22ea7cc 3021 pop(@hist) if length($cmd) > 1;
69893cff 3022
e22ea7cc 3023 # Relative (- found)?
69893cff 3024 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 3025 # N - go to that particular command slot or the last
69893cff 3026 # thing if nothing following.
e22ea7cc 3027 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
69893cff
RGS
3028
3029 # Pick out the command desired.
e22ea7cc 3030 $cmd = $hist[$i];
69893cff
RGS
3031
3032 # Print the command to be executed and restart the loop
3033 # with that command in the buffer.
e22ea7cc
RF
3034 print $OUT $cmd, "\n";
3035 redo CMD;
3036 };
69893cff
RGS
3037
3038=head4 C<$sh$sh> - C<system()> command
3039
3040Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3041C<STDOUT> from getting messed up.
3042
3043=cut
3044
3045 # $sh$sh - run a shell command (if it's all ASCII).
3046 # Can't run shell commands with Unicode in the debugger, hmm.
e22ea7cc
RF
3047 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3048
69893cff 3049 # System it.
e22ea7cc
RF
3050 &system($1);
3051 next CMD;
3052 };
69893cff
RGS
3053
3054=head4 C<$rc I<pattern> $rc> - Search command history
3055
3056Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3057If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3058
3059=cut
3060
e22ea7cc
RF
3061 # $rc pattern $rc - find a command in the history.
3062 $cmd =~ /^$rc([^$rc].*)$/ && do {
3063
69893cff 3064 # Create the pattern to use.
e22ea7cc 3065 $pat = "^$1";
69893cff
RGS
3066
3067 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 3068 pop(@hist) if length($cmd) > 1;
69893cff
RGS
3069
3070 # Look backward through the history.
e22ea7cc
RF
3071 for ( $i = $#hist ; $i ; --$i ) {
3072
69893cff 3073 # Stop if we find it.
e22ea7cc
RF
3074 last if $hist[$i] =~ /$pat/;
3075 }
3076
3077 if ( !$i ) {
69893cff 3078
69893cff 3079 # Never found it.
e22ea7cc
RF
3080 print $OUT "No such command!\n\n";
3081 next CMD;
3082 }
69893cff
RGS
3083
3084 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
3085 $cmd = $hist[$i];
3086 print $OUT $cmd, "\n";
3087 redo CMD;
3088 };
69893cff
RGS
3089
3090=head4 C<$sh> - Invoke a shell
3091
3092Uses C<DB::system> to invoke a shell.
3093
3094=cut
3095
3096 # $sh - start a shell.
e22ea7cc
RF
3097 $cmd =~ /^$sh$/ && do {
3098
69893cff
RGS
3099 # Run the user's shell. If none defined, run Bourne.
3100 # We resume execution when the shell terminates.
e22ea7cc
RF
3101 &system( $ENV{SHELL} || "/bin/sh" );
3102 next CMD;
3103 };
69893cff
RGS
3104
3105=head4 C<$sh I<command>> - Force execution of a command in a shell
3106
3107Like the above, but the command is passed to the shell. Again, we use
3108C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3109
3110=cut
3111
3112 # $sh command - start a shell and run a command in it.
e22ea7cc
RF
3113 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3114
3115 # XXX: using csh or tcsh destroys sigint retvals!
3116 #&system($1); # use this instead
69893cff
RGS
3117
3118 # use the user's shell, or Bourne if none defined.
e22ea7cc
RF
3119 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3120 next CMD;
3121 };
69893cff
RGS
3122
3123=head4 C<H> - display commands in history
3124
3125Prints the contents of C<@hist> (if any).
3126
3127=cut
3128
7fddc82f
RF
3129 $cmd =~ /^H\b\s*\*/ && do {
3130 @hist = @truehist = ();
3131 print $OUT "History cleansed\n";
3132 next CMD;
3133 };
e22ea7cc
RF
3134
3135 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3136
3137 # Anything other than negative numbers is ignored by
69893cff 3138 # the (incorrect) pattern, so this test does nothing.
e22ea7cc 3139 $end = $2 ? ( $#hist - $2 ) : 0;
69893cff
RGS
3140
3141 # Set to the minimum if less than zero.
e22ea7cc 3142 $hist = 0 if $hist < 0;
69893cff 3143
e22ea7cc 3144 # Start at the end of the array.
69893cff
RGS
3145 # Stay in while we're still above the ending value.
3146 # Tick back by one each time around the loop.
e22ea7cc 3147 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3148
3149 # Print the command unless it has no arguments.
e22ea7cc
RF
3150 print $OUT "$i: ", $hist[$i], "\n"
3151 unless $hist[$i] =~ /^.?$/;
3152 }
3153 next CMD;
3154 };
69893cff
RGS
3155
3156=head4 C<man, doc, perldoc> - look up documentation
3157
3158Just calls C<runman()> to print the appropriate document.
3159
3160=cut
3161
e22ea7cc
RF
3162 # man, perldoc, doc - show manual pages.
3163 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3164 runman($1);
3165 next CMD;
3166 };
69893cff
RGS
3167
3168=head4 C<p> - print
3169
3170Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3171the bottom of the loop.
3172
3173=cut
3174
3175 # p - print (no args): print $_.
e22ea7cc 3176 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
69893cff
RGS
3177
3178 # p - print the given expression.
e22ea7cc 3179 $cmd =~ s/^p\b/print {\$DB::OUT} /;
69893cff
RGS
3180
3181=head4 C<=> - define command alias
3182
3183Manipulates C<%alias> to add or list command aliases.
3184
3185=cut
3186
e22ea7cc
RF
3187 # = - set up a command alias.
3188 $cmd =~ s/^=\s*// && do {
3189 my @keys;
3190 if ( length $cmd == 0 ) {
3191
69893cff 3192 # No args, get current aliases.
e22ea7cc
RF
3193 @keys = sort keys %alias;
3194 }
3195 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3196
69893cff
RGS
3197 # Creating a new alias. $k is alias name, $v is
3198 # alias value.
3199
e22ea7cc
RF
3200 # can't use $_ or kill //g state
3201 for my $x ( $k, $v ) {
3202
3203 # Escape "alarm" characters.
3204 $x =~ s/\a/\\a/g;
3205 }
69893cff
RGS
3206
3207 # Substitute key for value, using alarm chars
e22ea7cc 3208 # as separators (which is why we escaped them in
69893cff 3209 # the command).
e22ea7cc 3210 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3211
3212 # Turn off standard warn and die behavior.
e22ea7cc
RF
3213 local $SIG{__DIE__};
3214 local $SIG{__WARN__};
69893cff
RGS
3215
3216 # Is it valid Perl?
e22ea7cc
RF
3217 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3218
69893cff 3219 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3220 print $OUT "Can't alias $k to $v: $@\n";
3221 delete $alias{$k};
3222 next CMD;
3223 }
3224
69893cff 3225 # We'll only list the new one.
e22ea7cc 3226 @keys = ($k);
69893cff
RGS
3227 } ## end elsif (my ($k, $v) = ($cmd...
3228
3229 # The argument is the alias to list.
e22ea7cc
RF
3230 else {
3231 @keys = ($cmd);
3232 }
69893cff
RGS
3233
3234 # List aliases.
e22ea7cc
RF
3235 for my $k (@keys) {
3236
69893cff
RGS
3237 # Messy metaquoting: Trim the substiution code off.
3238 # We use control-G as the delimiter because it's not
3239 # likely to appear in the alias.
e22ea7cc
RF
3240 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3241
69893cff 3242 # Print the alias.
e22ea7cc
RF
3243 print $OUT "$k\t= $1\n";
3244 }
3245 elsif ( defined $alias{$k} ) {
3246
69893cff 3247 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3248 print $OUT "$k\t$alias{$k}\n";
3249 }
3250 else {
3251
69893cff 3252 # No such, dude.
e22ea7cc
RF
3253 print "No alias for $k\n";
3254 }
69893cff 3255 } ## end for my $k (@keys)
e22ea7cc
RF
3256 next CMD;
3257 };
69893cff
RGS
3258
3259=head4 C<source> - read commands from a file.
3260
3261Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3262pick it up.
3263
3264=cut
3265
e22ea7cc
RF
3266 # source - read commands from a file (or pipe!) and execute.
3267 $cmd =~ /^source\s+(.*\S)/ && do {
3268 if ( open my $fh, $1 ) {
3269
69893cff 3270 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3271 push @cmdfhs, $fh;
3272 }
3273 else {
3274
3275 # Couldn't open it.
3276 &warn("Can't execute `$1': $!\n");
3277 }
3278 next CMD;
3279 };
69893cff
RGS
3280
3281=head4 C<save> - send current history to a file
3282
3283Takes the complete history, (not the shrunken version you see with C<H>),
3284and saves it to the given filename, so it can be replayed using C<source>.
3285
3286Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3287
3288=cut
3289
3290 # save source - write commands to a file for later use
3291 $cmd =~ /^save\s*(.*)$/ && do {
e22ea7cc
RF
3292 my $file = $1 || '.perl5dbrc'; # default?
3293 if ( open my $fh, "> $file" ) {
3294
3295 # chomp to remove extraneous newlines from source'd files
3296 chomp( my @truelist =
3297 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3298 @truehist );
3299 print $fh join( "\n", @truelist );
69893cff 3300 print "commands saved in $file\n";
e22ea7cc
RF
3301 }
3302 else {
69893cff
RGS
3303 &warn("Can't save debugger commands in '$1': $!\n");
3304 }
3305 next CMD;
3306 };
3307
7fddc82f
RF
3308=head4 C<R> - restart
3309
3310Restart the debugger session.
3311
3312=head4 C<rerun> - rerun the current session
3313
3314Return to any given position in the B<true>-history list
3315
3316=cut
3317
3318 # R - restart execution.
3319 # rerun - controlled restart execution.
3320 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3321 my @args = ($1 eq 'R' ? restart() : rerun($2));
3322
ca28b541
AP
3323 # Close all non-system fds for a clean restart. A more
3324 # correct method would be to close all fds that were not
3325 # open when the process started, but this seems to be
3326 # hard. See "debugger 'R'estart and open database
3327 # connections" on p5p.
3328
47d3bbda 3329 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541
AP
3330 if (eval { require POSIX }) {
3331 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3332 }
3333
3334 if (defined $max_fd) {
3335 foreach ($^F+1 .. $max_fd-1) {
3336 next unless open FD_TO_CLOSE, "<&=$_";
3337 close(FD_TO_CLOSE);
3338 }
3339 }
3340
7fddc82f
RF
3341 # And run Perl again. We use exec() to keep the
3342 # PID stable (and that way $ini_pids is still valid).
3343 exec(@args) || print $OUT "exec failed: $!\n";
3344
3345 last CMD;
3346 };
3347
69893cff
RGS
3348=head4 C<|, ||> - pipe output through the pager.
3349
be9a9b1d 3350For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3351(the program's standard output). For C<||>, we only save C<OUT>. We open a
3352pipe to the pager (restoring the output filehandles if this fails). If this
3353is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3354set C<$signal>, sending us back into the debugger.
3355
3356We then trim off the pipe symbols and C<redo> the command loop at the
3357C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3358reading another.
3359
3360=cut
3361
3362 # || - run command in the pager, with output to DB::OUT.
e22ea7cc
RF
3363 $cmd =~ /^\|\|?\s*[^|]/ && do {
3364 if ( $pager =~ /^\|/ ) {
3365
69893cff 3366 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3367 open( SAVEOUT, ">&STDOUT" )
3368 || &warn("Can't save STDOUT");
3369 open( STDOUT, ">&OUT" )
3370 || &warn("Can't redirect STDOUT");
69893cff 3371 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3372 else {
3373
69893cff 3374 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3375 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3376 }
69893cff
RGS
3377
3378 # Fix up environment to record we have less if so.
e22ea7cc
RF
3379 fix_less();
3380
3381 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3382
69893cff 3383 # Couldn't open pipe to pager.
e22ea7cc
RF
3384 &warn("Can't pipe output to `$pager'");
3385 if ( $pager =~ /^\|/ ) {
3386
69893cff 3387 # Redirect I/O back again.
e22ea7cc
RF
3388 open( OUT, ">&STDOUT" ) # XXX: lost message
3389 || &warn("Can't restore DB::OUT");
3390 open( STDOUT, ">&SAVEOUT" )
3391 || &warn("Can't restore STDOUT");
3392 close(SAVEOUT);
69893cff 3393 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3394 else {
3395
69893cff 3396 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3397 open( OUT, ">&STDOUT" ) # XXX: lost message
3398 || &warn("Can't restore DB::OUT");
3399 }
3400 next CMD;
69893cff
RGS
3401 } ## end unless ($piped = open(OUT,...
3402
3403 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3404 $SIG{PIPE} = \&DB::catch
3405 if $pager =~ /^\|/
3406 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff
RGS
3407
3408 # Save current filehandle, unbuffer out, and put it back.
e22ea7cc
RF
3409 $selected = select(OUT);
3410 $| = 1;
69893cff
RGS
3411
3412 # Don't put it back if pager was a pipe.
e22ea7cc 3413 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3414
3415 # Trim off the pipe symbols and run the command now.
e22ea7cc
RF
3416 $cmd =~ s/^\|+\s*//;
3417 redo PIPE;
3418 };
69893cff
RGS
3419
3420=head3 END OF COMMAND PARSING
3421
3422Anything left in C<$cmd> at this point is a Perl expression that we want to
3423evaluate. We'll always evaluate in the user's context, and fully qualify
3424any variables we might want to address in the C<DB> package.
3425
3426=cut
3427
3428 # t - turn trace on.
e22ea7cc 3429 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
69893cff
RGS
3430
3431 # s - single-step. Remember the last command was 's'.
e22ea7cc 3432 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
69893cff
RGS
3433
3434 # n - single-step, but not into subs. Remember last command
e22ea7cc
RF
3435 # was 'n'.
3436 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
69893cff 3437
e22ea7cc 3438 } # PIPE:
69893cff 3439
e22ea7cc 3440 # Make sure the flag that says "the debugger's running" is
69893cff 3441 # still on, to make sure we get control again.
e22ea7cc 3442 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3443
3444 # Run *our* eval that executes in the caller's context.
e22ea7cc 3445 &eval;
69893cff
RGS
3446
3447 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3448 if ($onetimeDump) {
3449 $onetimeDump = undef;
69893cff 3450 $onetimedumpDepth = undef;
e22ea7cc
RF
3451 }
3452 elsif ( $term_pid == $$ ) {
c7e68384
IZ
3453 eval { # May run under miniperl, when not available...
3454 STDOUT->flush();
3455 STDERR->flush();
3456 };
e22ea7cc 3457
69893cff 3458 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3459 print $OUT "\n";
3460 }
3461 } ## end while (($term || &setterm...
69893cff
RGS
3462
3463=head3 POST-COMMAND PROCESSING
3464
3465After each command, we check to see if the command output was piped anywhere.
3466If so, we go through the necessary code to unhook the pipe and go back to
3467our standard filehandles for input and output.
3468
3469=cut
3470
e22ea7cc 3471 continue { # CMD:
69893cff
RGS
3472
3473 # At the end of every command:
e22ea7cc
RF
3474 if ($piped) {
3475
69893cff 3476 # Unhook the pipe mechanism now.
e22ea7cc
RF
3477 if ( $pager =~ /^\|/ ) {
3478
69893cff 3479 # No error from the child.
e22ea7cc 3480 $? = 0;
69893cff 3481
e22ea7cc
RF
3482 # we cannot warn here: the handle is missing --tchrist
3483 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3484
e22ea7cc 3485 # most of the $? crud was coping with broken cshisms
69893cff 3486 # $? is explicitly set to 0, so this never runs.
e22ea7cc
RF
3487 if ($?) {
3488 print SAVEOUT "Pager `$pager' failed: ";
3489 if ( $? == -1 ) {
3490 print SAVEOUT "shell returned -1\n";
3491 }
3492 elsif ( $? >> 8 ) {
3493 print SAVEOUT ( $? & 127 )
3494 ? " (SIG#" . ( $? & 127 ) . ")"
3495 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3496 }
3497 else {
3498 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3499 }
69893cff
RGS
3500 } ## end if ($?)
3501
e22ea7cc 3502 # Reopen filehandle for our output (if we can) and
69893cff 3503 # restore STDOUT (if we can).
e22ea7cc
RF
3504 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3505 open( STDOUT, ">&SAVEOUT" )
3506 || &warn("Can't restore STDOUT");
69893cff
RGS
3507
3508 # Turn off pipe exception handler if necessary.
e22ea7cc 3509 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3510
e22ea7cc
RF
3511 # Will stop ignoring SIGPIPE if done like nohup(1)
3512 # does SIGINT but Perl doesn't give us a choice.
69893cff 3513 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3514 else {
3515
69893cff 3516 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3517 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3518 }
69893cff
RGS
3519
3520 # Close filehandle pager was using, restore the normal one
3521 # if necessary,
3522 close(SAVEOUT);
e22ea7cc 3523 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3524
3525 # No pipes now.
e22ea7cc 3526 $piped = "";
69893cff 3527 } ## end if ($piped)
e22ea7cc 3528 } # CMD:
69893cff
RGS
3529
3530=head3 COMMAND LOOP TERMINATION
3531
3532When commands have finished executing, we come here. If the user closed the
3533input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3534evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3535C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3536The interpreter will then execute the next line and then return control to us
3537again.
3538
3539=cut
3540
3541 # No more commands? Quit.
e22ea7cc 3542 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
69893cff
RGS
3543
3544 # Evaluate post-prompt commands.
e22ea7cc
RF
3545 foreach $evalarg (@$post) {
3546 &eval;
3547 }
3548 } # if ($single || $signal)
69893cff
RGS
3549
3550 # Put the user's globals back where you found them.
e22ea7cc 3551 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3552 ();
3553} ## end sub DB
3554
3555# The following code may be executed now:
3556# BEGIN {warn 4}
3557
3558=head2 sub
3559
3560C<sub> is called whenever a subroutine call happens in the program being
3561debugged. The variable C<$DB::sub> contains the name of the subroutine
3562being called.
3563
3564The core function of this subroutine is to actually call the sub in the proper
3565context, capturing its output. This of course causes C<DB::DB> to get called
3566again, repeating until the subroutine ends and returns control to C<DB::sub>
3567again. Once control returns, C<DB::sub> figures out whether or not to dump the
3568return value, and returns its captured copy of the return value as its own
3569return value. The value then feeds back into the program being debugged as if
3570C<DB::sub> hadn't been there at all.
3571
3572C<sub> does all the work of printing the subroutine entry and exit messages
3573enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3574and also prints the return value if needed (for the C<r> command and if
3575the 16 bit is set in C<$frame>).
3576
3577It also tracks the subroutine call depth by saving the current setting of
3578C<$single> in the C<@stack> package global; if this exceeds the value in
3579C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3580setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3581of stop/don't stop on entry to subs set as it currently is set.
3582
3583=head3 C<caller()> support
3584
3585If C<caller()> is called from the package C<DB>, it provides some
3586additional data, in the following order:
3587
3588=over 4
3589
3590=item * C<$package>
3591
3592The package name the sub was in
3593
3594=item * C<$filename>
3595
3596The filename it was defined in
3597
3598=item * C<$line>
3599
3600The line number it was defined on
3601
3602=item * C<$subroutine>
3603
be9a9b1d 3604The subroutine name; C<(eval)> if an C<eval>().
69893cff
RGS
3605
3606=item * C<$hasargs>
3607
36081 if it has arguments, 0 if not
3609
3610=item * C<$wantarray>
3611
36121 if array context, 0 if scalar context
3613
3614=item * C<$evaltext>
3615
3616The C<eval>() text, if any (undefined for C<eval BLOCK>)
3617
3618=item * C<$is_require>
3619
3620frame was created by a C<use> or C<require> statement
3621
3622=item * C<$hints>
3623
3624pragma information; subject to change between versions
3625
3626=item * C<$bitmask>
3627
be9a9b1d 3628pragma information; subject to change between versions
69893cff
RGS
3629
3630=item * C<@DB::args>
3631
3632arguments with which the subroutine was invoked
3633
3634=back
3635
3636=cut
d338d6fe 3637
d12a4851 3638sub sub {
69893cff 3639
2cbb2ee1
RGS
3640 # lock ourselves under threads
3641 lock($DBGR);
3642
69893cff
RGS
3643 # Whether or not the autoloader was running, a scalar to put the
3644 # sub's return value in (if needed), and an array to put the sub's
3645 # return value in (if needed).
e22ea7cc 3646 my ( $al, $ret, @ret ) = "";
2cbb2ee1
RGS
3647 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3648 print "creating new thread\n";
3649 }
69893cff
RGS
3650
3651 # If the last ten characters are C'::AUTOLOAD', note we've traced
3652 # into AUTOLOAD for $sub.
e22ea7cc
RF
3653 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3654 $al = " for $$sub";
d12a4851 3655 }
69893cff
RGS
3656
3657 # We stack the stack pointer and then increment it to protect us
3658 # from a situation that might unwind a whole bunch of call frames
3659 # at once. Localizing the stack pointer means that it will automatically
3660 # unwind the same amount when multiple stack frames are unwound.
e22ea7cc 3661 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
69893cff
RGS
3662
3663 # Expand @stack.
d12a4851 3664 $#stack = $stack_depth;
69893cff
RGS
3665
3666 # Save current single-step setting.
d12a4851 3667 $stack[-1] = $single;
69893cff 3668
e22ea7cc 3669 # Turn off all flags except single-stepping.
d12a4851 3670 $single &= 1;
69893cff
RGS
3671
3672 # If we've gotten really deeply recursed, turn on the flag that will
3673 # make us stop with the 'deep recursion' message.
d12a4851 3674 $single |= 4 if $stack_depth == $deep;
69893cff
RGS
3675
3676 # If frame messages are on ...
3677 (
3678 $frame & 4 # Extended frame entry message
e22ea7cc
RF
3679 ? (
3680 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
69893cff 3681
e22ea7cc 3682 # Why -1? But it works! :-(
69893cff
RGS
3683 # Because print_trace will call add 1 to it and then call
3684 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3685 # in dump_trace.
e22ea7cc
RF
3686 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3687 )
3688 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3689
69893cff 3690 # standard frame entry message
e22ea7cc
RF
3691 )
3692 if $frame;
69893cff
RGS
3693
3694 # Determine the sub's return type,and capture approppriately.
d12a4851 3695 if (wantarray) {
e22ea7cc 3696
69893cff
RGS
3697 # Called in array context. call sub and capture output.
3698 # DB::DB will recursively get control again if appropriate; we'll come
3699 # back here when the sub is finished.
d12a4851 3700 if ($assertion) {
e22ea7cc
RF
3701 $assertion = 0;
3702 eval { @ret = &$sub; };
3703 if ($@) {
3704 print $OUT $@;
3705 $signal = 1 unless $warnassertions;
3706 }