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Security fix from Debian in the debugger (in the setterm()
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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
224If false, a dummy ReadLine is used, so you can debug
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
240=back
241
242=head3 SAMPLE RCFILE
243
244 &parse_options("NonStop=1 LineInfo=db.out");
245 sub afterinit { $trace = 1; }
246
247The script will run without human intervention, putting trace
248information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 249reset C<LineInfo> to something I<interactive>!)
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250
251=head1 INTERNALS DESCRIPTION
252
253=head2 DEBUGGER INTERFACE VARIABLES
254
255Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 256a C<&DB::DB();> in front of each place that can have a
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257breakpoint. At each subroutine call, it calls C<&DB::sub> with
258C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
259{require 'perl5db.pl'}> before the first line.
260
261After each C<require>d file is compiled, but before it is executed, a
262call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
263is the expanded name of the C<require>d file (as found via C<%INC>).
264
265=head3 IMPORTANT INTERNAL VARIABLES
266
267=head4 C<$CreateTTY>
268
269Used to control when the debugger will attempt to acquire another TTY to be
270used for input.
271
272=over
273
274=item * 1 - on C<fork()>
275
276=item * 2 - debugger is started inside debugger
277
278=item * 4 - on startup
279
280=back
281
282=head4 C<$doret>
283
284The value -2 indicates that no return value should be printed.
285Any other positive value causes C<DB::sub> to print return values.
286
287=head4 C<$evalarg>
288
289The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
290contents of C<@_> when C<DB::eval> is called.
291
292=head4 C<$frame>
293
294Determines what messages (if any) will get printed when a subroutine (or eval)
295is entered or exited.
296
297=over 4
298
299=item * 0 - No enter/exit messages
300
be9a9b1d 301=item * 1 - Print I<entering> messages on subroutine entry
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302
303=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
304
be9a9b1d 305=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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306
307=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.
308
309=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.
310
311=back
312
be9a9b1d 313To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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314The debugger internally juggles the value of C<$frame> during execution to
315protect external modules that the debugger uses from getting traced.
316
317=head4 C<$level>
318
319Tracks current debugger nesting level. Used to figure out how many
320C<E<lt>E<gt>> pairs to surround the line number with when the debugger
321outputs a prompt. Also used to help determine if the program has finished
322during command parsing.
323
324=head4 C<$onetimeDump>
325
326Controls what (if anything) C<DB::eval()> will print after evaluating an
327expression.
328
329=over 4
330
331=item * C<undef> - don't print anything
332
333=item * C<dump> - use C<dumpvar.pl> to display the value returned
334
335=item * C<methods> - print the methods callable on the first item returned
336
337=back
338
339=head4 C<$onetimeDumpDepth>
340
be9a9b1d 341Controls how far down C<dumpvar.pl> will go before printing C<...> while
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342dumping a structure. Numeric. If C<undef>, print all levels.
343
344=head4 C<$signal>
345
346Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
347which is called before every statement, checks this and puts the user into
348command mode if it finds C<$signal> set to a true value.
349
350=head4 C<$single>
351
352Controls behavior during single-stepping. Stacked in C<@stack> on entry to
353each subroutine; popped again at the end of each subroutine.
354
355=over 4
356
357=item * 0 - run continuously.
358
be9a9b1d 359=item * 1 - single-step, go into subs. The C<s> command.
69893cff 360
be9a9b1d 361=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 362
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363=item * 4 - print current sub depth (turned on to force this when C<too much
364recursion> occurs.
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365
366=back
367
368=head4 C<$trace>
369
370Controls the output of trace information.
371
372=over 4
373
374=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
375
376=item * 2 - watch expressions are active
377
378=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
379
380=back
381
382=head4 C<$slave_editor>
383
3841 if C<LINEINFO> was directed to a pipe; 0 otherwise.
385
386=head4 C<@cmdfhs>
387
388Stack of filehandles that C<DB::readline()> will read commands from.
389Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
390
391=head4 C<@dbline>
392
393Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
394supplied by the Perl interpreter to the debugger. Contains the source.
395
396=head4 C<@old_watch>
397
398Previous values of watch expressions. First set when the expression is
399entered; reset whenever the watch expression changes.
400
401=head4 C<@saved>
402
403Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
404so that the debugger can substitute safe values while it's running, and
405restore them when it returns control.
406
407=head4 C<@stack>
408
409Saves the current value of C<$single> on entry to a subroutine.
410Manipulated by the C<c> command to turn off tracing in all subs above the
411current one.
412
413=head4 C<@to_watch>
414
415The 'watch' expressions: to be evaluated before each line is executed.
416
417=head4 C<@typeahead>
418
419The typeahead buffer, used by C<DB::readline>.
420
421=head4 C<%alias>
422
423Command aliases. Stored as character strings to be substituted for a command
424entered.
425
426=head4 C<%break_on_load>
427
428Keys are file names, values are 1 (break when this file is loaded) or undef
429(don't break when it is loaded).
430
431=head4 C<%dbline>
432
be9a9b1d 433Keys are line numbers, values are C<condition\0action>. If used in numeric
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434context, values are 0 if not breakable, 1 if breakable, no matter what is
435in the actual hash entry.
436
437=head4 C<%had_breakpoints>
438
439Keys are file names; values are bitfields:
440
441=over 4
442
443=item * 1 - file has a breakpoint in it.
444
445=item * 2 - file has an action in it.
446
447=back
448
449A zero or undefined value means this file has neither.
450
451=head4 C<%option>
452
453Stores the debugger options. These are character string values.
454
455=head4 C<%postponed>
456
457Saves breakpoints for code that hasn't been compiled yet.
458Keys are subroutine names, values are:
459
460=over 4
461
be9a9b1d 462=item * C<compile> - break when this sub is compiled
69893cff 463
be9a9b1d 464=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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465
466=back
467
468=head4 C<%postponed_file>
469
470This hash keeps track of breakpoints that need to be set for files that have
471not yet been compiled. Keys are filenames; values are references to hashes.
472Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 473definitions (C<condition\0action>).
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474
475=head1 DEBUGGER INITIALIZATION
476
477The debugger's initialization actually jumps all over the place inside this
478package. This is because there are several BEGIN blocks (which of course
479execute immediately) spread through the code. Why is that?
480
481The debugger needs to be able to change some things and set some things up
482before the debugger code is compiled; most notably, the C<$deep> variable that
483C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
484debugger has to turn off warnings while the debugger code is compiled, but then
485restore them to their original setting before the program being debugged begins
486executing.
487
488The first C<BEGIN> block simply turns off warnings by saving the current
489setting of C<$^W> and then setting it to zero. The second one initializes
490the debugger variables that are needed before the debugger begins executing.
491The third one puts C<$^X> back to its former value.
492
493We'll detail the second C<BEGIN> block later; just remember that if you need
494to initialize something before the debugger starts really executing, that's
495where it has to go.
496
497=cut
498
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499package DB;
500
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501use IO::Handle;
502
54d04a52 503# Debugger for Perl 5.00x; perl5db.pl patch level:
2cbb2ee1 504$VERSION = 1.28;
69893cff 505
e22ea7cc 506$header = "perl5db.pl version $VERSION";
d338d6fe 507
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508=head1 DEBUGGER ROUTINES
509
510=head2 C<DB::eval()>
511
512This function replaces straight C<eval()> inside the debugger; it simplifies
513the process of evaluating code in the user's context.
514
515The code to be evaluated is passed via the package global variable
516C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
517
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518Before we do the C<eval()>, we preserve the current settings of C<$trace>,
519C<$single>, C<$^D> and C<$usercontext>. The latter contains the
520preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
521user's current package, grabbed when C<DB::DB> got control. This causes the
522proper context to be used when the eval is actually done. Afterward, we
523restore C<$trace>, C<$single>, and C<$^D>.
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524
525Next we need to handle C<$@> without getting confused. We save C<$@> in a
526local lexical, localize C<$saved[0]> (which is where C<save()> will put
527C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
528C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
529considered sane by the debugger. If there was an C<eval()> error, we print
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530it on the debugger's output. If C<$onetimedump> is defined, we call
531C<dumpit> if it's set to 'dump', or C<methods> if it's set to
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532'methods'. Setting it to something else causes the debugger to do the eval
533but not print the result - handy if you want to do something else with it
534(the "watch expressions" code does this to get the value of the watch
535expression but not show it unless it matters).
536
537In any case, we then return the list of output from C<eval> to the caller,
538and unwinding restores the former version of C<$@> in C<@saved> as well
539(the localization of C<$saved[0]> goes away at the end of this scope).
540
541=head3 Parameters and variables influencing execution of DB::eval()
542
543C<DB::eval> isn't parameterized in the standard way; this is to keep the
544debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
545The variables listed below influence C<DB::eval()>'s execution directly.
546
547=over 4
548
549=item C<$evalarg> - the thing to actually be eval'ed
550
be9a9b1d 551=item C<$trace> - Current state of execution tracing
69893cff 552
be9a9b1d 553=item C<$single> - Current state of single-stepping
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554
555=item C<$onetimeDump> - what is to be displayed after the evaluation
556
557=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
558
559=back
560
561The following variables are altered by C<DB::eval()> during its execution. They
562are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
563
564=over 4
565
566=item C<@res> - used to capture output from actual C<eval>.
567
568=item C<$otrace> - saved value of C<$trace>.
569
570=item C<$osingle> - saved value of C<$single>.
571
572=item C<$od> - saved value of C<$^D>.
573
574=item C<$saved[0]> - saved value of C<$@>.
575
576=item $\ - for output of C<$@> if there is an evaluation error.
577
578=back
579
580=head3 The problem of lexicals
581
582The context of C<DB::eval()> presents us with some problems. Obviously,
583we want to be 'sandboxed' away from the debugger's internals when we do
584the eval, but we need some way to control how punctuation variables and
585debugger globals are used.
586
587We can't use local, because the code inside C<DB::eval> can see localized
588variables; and we can't use C<my> either for the same reason. The code
589in this routine compromises and uses C<my>.
590
591After this routine is over, we don't have user code executing in the debugger's
592context, so we can use C<my> freely.
593
594=cut
595
596############################################## Begin lexical danger zone
597
598# 'my' variables used here could leak into (that is, be visible in)
599# the context that the code being evaluated is executing in. This means that
600# the code could modify the debugger's variables.
601#
602# Fiddling with the debugger's context could be Bad. We insulate things as
603# much as we can.
604
c1051fcf 605sub eval {
69893cff 606
c1051fcf 607 # 'my' would make it visible from user code
e22ea7cc 608 # but so does local! --tchrist
69893cff 609 # Remember: this localizes @DB::res, not @main::res.
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610 local @res;
611 {
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612
613 # Try to keep the user code from messing with us. Save these so that
614 # even if the eval'ed code changes them, we can put them back again.
615 # Needed because the user could refer directly to the debugger's
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616 # package globals (and any 'my' variables in this containing scope)
617 # inside the eval(), and we want to try to stay safe.
e22ea7cc 618 local $otrace = $trace;
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619 local $osingle = $single;
620 local $od = $^D;
621
622 # Untaint the incoming eval() argument.
623 { ($evalarg) = $evalarg =~ /(.*)/s; }
624
e22ea7cc 625 # $usercontext built in DB::DB near the comment
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626 # "set up the context for DB::eval ..."
627 # Evaluate and save any results.
e22ea7cc 628 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
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629
630 # Restore those old values.
631 $trace = $otrace;
632 $single = $osingle;
633 $^D = $od;
c1051fcf 634 }
69893cff
RGS
635
636 # Save the current value of $@, and preserve it in the debugger's copy
637 # of the saved precious globals.
c1051fcf 638 my $at = $@;
69893cff
RGS
639
640 # Since we're only saving $@, we only have to localize the array element
641 # that it will be stored in.
e22ea7cc 642 local $saved[0]; # Preserve the old value of $@
c1051fcf 643 eval { &DB::save };
69893cff
RGS
644
645 # Now see whether we need to report an error back to the user.
c1051fcf 646 if ($at) {
69893cff
RGS
647 local $\ = '';
648 print $OUT $at;
649 }
650
651 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
652 # are package globals.
653 elsif ($onetimeDump) {
e22ea7cc
RF
654 if ( $onetimeDump eq 'dump' ) {
655 local $option{dumpDepth} = $onetimedumpDepth
656 if defined $onetimedumpDepth;
657 dumpit( $OUT, \@res );
658 }
659 elsif ( $onetimeDump eq 'methods' ) {
660 methods( $res[0] );
661 }
69893cff 662 } ## end elsif ($onetimeDump)
c1051fcf 663 @res;
69893cff
RGS
664} ## end sub eval
665
666############################################## End lexical danger zone
c1051fcf 667
e22ea7cc
RF
668# After this point it is safe to introduce lexicals.
669# The code being debugged will be executing in its own context, and
69893cff 670# can't see the inside of the debugger.
d338d6fe 671#
e22ea7cc 672# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
673# possible. If you make something a lexical, it's not going to be addressable
674# from outside the debugger even if you know its name.
675
d338d6fe
PP
676# This file is automatically included if you do perl -d.
677# It's probably not useful to include this yourself.
678#
e22ea7cc 679# Before venturing further into these twisty passages, it is
2f7e9187
MS
680# wise to read the perldebguts man page or risk the ire of dragons.
681#
69893cff
RGS
682# (It should be noted that perldebguts will tell you a lot about
683# the underlying mechanics of how the debugger interfaces into the
684# Perl interpreter, but not a lot about the debugger itself. The new
685# comments in this code try to address this problem.)
686
d338d6fe 687# Note that no subroutine call is possible until &DB::sub is defined
36477c24 688# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 689# true if $deep is not defined.
055fd3a9
GS
690
691# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
692
693# modified Perl debugger, to be run from Emacs in perldb-mode
694# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
695# Johan Vromans -- upgrade to 4.0 pl 10
696# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
697
69893cff
RGS
698# (We have made efforts to clarify the comments in the change log
699# in other places; some of them may seem somewhat obscure as they
700# were originally written, and explaining them away from the code
701# in question seems conterproductive.. -JM)
702
703########################################################################
704# Changes: 0.94
705# + A lot of things changed after 0.94. First of all, core now informs
706# debugger about entry into XSUBs, overloaded operators, tied operations,
707# BEGIN and END. Handy with `O f=2'.
708# + This can make debugger a little bit too verbose, please be patient
709# and report your problems promptly.
710# + Now the option frame has 3 values: 0,1,2. XXX Document!
711# + Note that if DESTROY returns a reference to the object (or object),
712# the deletion of data may be postponed until the next function call,
713# due to the need to examine the return value.
714#
715# Changes: 0.95
716# + `v' command shows versions.
717#
e22ea7cc 718# Changes: 0.96
69893cff
RGS
719# + `v' command shows version of readline.
720# primitive completion works (dynamic variables, subs for `b' and `l',
721# options). Can `p %var'
722# + Better help (`h <' now works). New commands <<, >>, {, {{.
723# {dump|print}_trace() coded (to be able to do it from <<cmd).
724# + `c sub' documented.
725# + At last enough magic combined to stop after the end of debuggee.
726# + !! should work now (thanks to Emacs bracket matching an extra
727# `]' in a regexp is caught).
728# + `L', `D' and `A' span files now (as documented).
729# + Breakpoints in `require'd code are possible (used in `R').
730# + Some additional words on internal work of debugger.
731# + `b load filename' implemented.
732# + `b postpone subr' implemented.
733# + now only `q' exits debugger (overwritable on $inhibit_exit).
734# + When restarting debugger breakpoints/actions persist.
e22ea7cc 735# + Buglet: When restarting debugger only one breakpoint/action per
69893cff
RGS
736# autoloaded function persists.
737#
36477c24 738# Changes: 0.97: NonStop will not stop in at_exit().
69893cff
RGS
739# + Option AutoTrace implemented.
740# + Trace printed differently if frames are printed too.
741# + new `inhibitExit' option.
742# + printing of a very long statement interruptible.
1d06cb2d 743# Changes: 0.98: New command `m' for printing possible methods
69893cff
RGS
744# + 'l -' is a synonym for `-'.
745# + Cosmetic bugs in printing stack trace.
746# + `frame' & 8 to print "expanded args" in stack trace.
747# + Can list/break in imported subs.
748# + new `maxTraceLen' option.
749# + frame & 4 and frame & 8 granted.
750# + new command `m'
751# + nonstoppable lines do not have `:' near the line number.
752# + `b compile subname' implemented.
753# + Will not use $` any more.
754# + `-' behaves sane now.
477ea2b1 755# Changes: 0.99: Completion for `f', `m'.
69893cff
RGS
756# + `m' will remove duplicate names instead of duplicate functions.
757# + `b load' strips trailing whitespace.
758# completion ignores leading `|'; takes into account current package
759# when completing a subroutine name (same for `l').
055fd3a9
GS
760# Changes: 1.07: Many fixed by tchrist 13-March-2000
761# BUG FIXES:
04e43a21 762# + Added bare minimal security checks on perldb rc files, plus
055fd3a9
GS
763# comments on what else is needed.
764# + Fixed the ornaments that made "|h" completely unusable.
765# They are not used in print_help if they will hurt. Strip pod
766# if we're paging to less.
767# + Fixed mis-formatting of help messages caused by ornaments
e22ea7cc
RF
768# to restore Larry's original formatting.
769# + Fixed many other formatting errors. The code is still suboptimal,
04e43a21 770# and needs a lot of work at restructuring. It's also misindented
055fd3a9
GS
771# in many places.
772# + Fixed bug where trying to look at an option like your pager
e22ea7cc 773# shows "1".
055fd3a9
GS
774# + Fixed some $? processing. Note: if you use csh or tcsh, you will
775# lose. You should consider shell escapes not using their shell,
776# or else not caring about detailed status. This should really be
777# unified into one place, too.
778# + Fixed bug where invisible trailing whitespace on commands hoses you,
04e43a21 779# tricking Perl into thinking you weren't calling a debugger command!
055fd3a9
GS
780# + Fixed bug where leading whitespace on commands hoses you. (One
781# suggests a leading semicolon or any other irrelevant non-whitespace
782# to indicate literal Perl code.)
783# + Fixed bugs that ate warnings due to wrong selected handle.
784# + Fixed a precedence bug on signal stuff.
785# + Fixed some unseemly wording.
786# + Fixed bug in help command trying to call perl method code.
787# + Fixed to call dumpvar from exception handler. SIGPIPE killed us.
788# ENHANCEMENTS:
789# + Added some comments. This code is still nasty spaghetti.
790# + Added message if you clear your pre/post command stacks which was
791# very easy to do if you just typed a bare >, <, or {. (A command
792# without an argument should *never* be a destructive action; this
793# API is fundamentally screwed up; likewise option setting, which
794# is equally buggered.)
795# + Added command stack dump on argument of "?" for >, <, or {.
796# + Added a semi-built-in doc viewer command that calls man with the
797# proper %Config::Config path (and thus gets caching, man -k, etc),
798# or else perldoc on obstreperous platforms.
799# + Added to and rearranged the help information.
800# + Detected apparent misuse of { ... } to declare a block; this used
801# to work but now is a command, and mysteriously gave no complaint.
04e43a21
DL
802#
803# Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com>
804# BUG FIX:
805# + This patch to perl5db.pl cleans up formatting issues on the help
806# summary (h h) screen in the debugger. Mostly columnar alignment
807# issues, plus converted the printed text to use all spaces, since
808# tabs don't seem to help much here.
809#
810# Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu>
69893cff
RGS
811# Minor bugs corrected;
812# + Support for auto-creation of new TTY window on startup, either
813# unconditionally, or if started as a kid of another debugger session;
814# + New `O'ption CreateTTY
815# I<CreateTTY> bits control attempts to create a new TTY on events:
e22ea7cc 816# 1: on fork()
69893cff
RGS
817# 2: debugger is started inside debugger
818# 4: on startup
819# + Code to auto-create a new TTY window on OS/2 (currently one
820# extra window per session - need named pipes to have more...);
821# + Simplified interface for custom createTTY functions (with a backward
822# compatibility hack); now returns the TTY name to use; return of ''
823# means that the function reset the I/O handles itself;
824# + Better message on the semantic of custom createTTY function;
825# + Convert the existing code to create a TTY into a custom createTTY
826# function;
827# + Consistent support for TTY names of the form "TTYin,TTYout";
828# + Switch line-tracing output too to the created TTY window;
829# + make `b fork' DWIM with CORE::GLOBAL::fork;
830# + High-level debugger API cmd_*():
04e43a21
DL
831# cmd_b_load($filenamepart) # b load filenamepart
832# cmd_b_line($lineno [, $cond]) # b lineno [cond]
833# cmd_b_sub($sub [, $cond]) # b sub [cond]
834# cmd_stop() # Control-C
492652be 835# cmd_d($lineno) # d lineno (B)
04e43a21
DL
836# The cmd_*() API returns FALSE on failure; in this case it outputs
837# the error message to the debugging output.
69893cff 838# + Low-level debugger API
04e43a21
DL
839# break_on_load($filename) # b load filename
840# @files = report_break_on_load() # List files with load-breakpoints
841# breakable_line_in_filename($name, $from [, $to])
842# # First breakable line in the
843# # range $from .. $to. $to defaults
e22ea7cc 844# # to $from, and may be less than
69893cff 845# # $to
04e43a21
DL
846# breakable_line($from [, $to]) # Same for the current file
847# break_on_filename_line($name, $lineno [, $cond])
e22ea7cc 848# # Set breakpoint,$cond defaults to
69893cff 849# # 1
04e43a21
DL
850# break_on_filename_line_range($name, $from, $to [, $cond])
851# # As above, on the first
852# # breakable line in range
853# break_on_line($lineno [, $cond]) # As above, in the current file
854# break_subroutine($sub [, $cond]) # break on the first breakable line
855# ($name, $from, $to) = subroutine_filename_lines($sub)
856# # The range of lines of the text
857# The low-level API returns TRUE on success, and die()s on failure.
858#
859# Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu>
860# BUG FIXES:
861# + Fixed warnings generated by "perl -dWe 42"
862# + Corrected spelling errors
863# + Squeezed Help (h) output into 80 columns
600d99fa
DL
864#
865# Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com>
866# + Made "x @INC" work like it used to
867#
868# Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu>
869# + Fixed warnings generated by "O" (Show debugger options)
870# + Fixed warnings generated by "p 42" (Print expression)
6f891d7d 871# Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com
e22ea7cc 872# + Added windowSize option
2f7e9187
MS
873# Changes: 1.14: Oct 9, 2001 multiple
874# + Clean up after itself on VMS (Charles Lane in 12385)
875# + Adding "@ file" syntax (Peter Scott in 12014)
876# + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457)
877# + $^S and other debugger fixes (Ilya Zakharevich in 11120)
878# + Forgot a my() declaration (Ilya Zakharevich in 11085)
879# Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com>
880# + Updated 1.14 change log
881# + Added *dbline explainatory comments
882# + Mentioning perldebguts man page
492652be 883# Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com>
69893cff 884# + $onetimeDump improvements
492652be
RF
885# Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net>
886# Moved some code to cmd_[.]()'s for clarity and ease of handling,
e22ea7cc
RF
887# rationalised the following commands and added cmd_wrapper() to
888# enable switching between old and frighteningly consistent new
492652be
RF
889# behaviours for diehards: 'o CommandSet=pre580' (sigh...)
890# a(add), A(del) # action expr (added del by line)
891# + b(add), B(del) # break [line] (was b,D)
e22ea7cc 892# + w(add), W(del) # watch expr (was W,W)
69893cff 893# # added del by expr
492652be
RF
894# + h(summary), h h(long) # help (hh) (was h h,h)
895# + m(methods), M(modules) # ... (was m,v)
896# + o(option) # lc (was O)
897# + v(view code), V(view Variables) # ... (was w,V)
aef14ef9
RF
898# Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net>
899# + fixed missing cmd_O bug
471505cc 900# Changes: 1.19: Mar 29, 2002 Spider Boardman
901# + Added missing local()s -- DB::DB is called recursively.
35408c4e
RF
902# Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net>
903# + pre'n'post commands no longer trashed with no args
904# + watch val joined out of eval()
69893cff
RGS
905# Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org>
906# + Added comments and reformatted source. No bug fixes/enhancements.
907# + Includes cleanup by Robin Barker and Jarkko Hietaniemi.
908# Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU>
909# + Flush stdout/stderr before the debugger prompt is printed.
910# Changes: 1.23: Dec 21, 2003 Dominique Quatravaux
de5e1a3d 911# + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug")
e219e2fb
RF
912# Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net>
913# + Added command to save all debugger commands for sourcing later.
914# + Added command to display parent inheritence tree of given class.
915# + Fixed minor newline in history bug.
e22ea7cc
RF
916# Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net>
917# + Fixed option bug (setting invalid options + not recognising valid short forms)
918# Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net>
919# + unfork the 5.8.x and 5.9.x debuggers.
920# + whitespace and assertions call cleanup across versions
921# + H * deletes (resets) history
922# + i now handles Class + blessed objects
7fddc82f
RF
923# Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net>
924# + updated pod page references - clunky.
925# + removed windowid restriction for forking into an xterm.
926# + more whitespace again.
927# + wrapped restart and enabled rerun [-n] (go back n steps) command.
2cbb2ee1
RGS
928# Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net>
929# + Added threads support (inc. e and E commands)
ee971a18 930####################################################################
d338d6fe 931
69893cff
RGS
932=head1 DEBUGGER INITIALIZATION
933
934The debugger starts up in phases.
935
936=head2 BASIC SETUP
937
938First, it initializes the environment it wants to run in: turning off
939warnings during its own compilation, defining variables which it will need
940to avoid warnings later, setting itself up to not exit when the program
941terminates, and defaulting to printing return values for the C<r> command.
942
943=cut
944
eda6e075 945# Needed for the statement after exec():
69893cff
RGS
946#
947# This BEGIN block is simply used to switch off warnings during debugger
948# compiliation. Probably it would be better practice to fix the warnings,
949# but this is how it's done at the moment.
eda6e075 950
e22ea7cc
RF
951BEGIN {
952 $ini_warn = $^W;
953 $^W = 0;
954} # Switch compilation warnings off until another BEGIN.
d12a4851
JH
955
956# test if assertions are supported and actived:
eda6e075 957BEGIN {
e22ea7cc
RF
958 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
959
d12a4851 960 # $ini_assertion = undef => assertions unsupported,
e22ea7cc 961 # " = 1 => assertions supported
d12a4851
JH
962 # print "\$ini_assertion=$ini_assertion\n";
963}
964
69893cff
RGS
965local ($^W) = 0; # Switch run-time warnings off during init.
966
2cbb2ee1
RGS
967=head2 THREADS SUPPORT
968
969If we are running under a threaded Perl, we require threads and threads::shared
970if the environment variable C<PERL5DB_THREADED> is set, to enable proper
971threaded debugger control. C<-dt> can also be used to set this.
972
973Each new thread will be announced and the debugger prompt will always inform
974you of each new thread created. It will also indicate the thread id in which
975we are currently running within the prompt like this:
976
977 [tid] DB<$i>
978
979Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
980command prompt. The prompt will show: C<[0]> when running under threads, but
981not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
982
983While running under threads, when you set or delete a breakpoint (etc.), this
984will apply to all threads, not just the currently running one. When you are
985in a currently executing thread, you will stay there until it completes. With
986the current implementation it is not currently possible to hop from one thread
987to another.
988
989The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
990
991Note that threading support was built into the debugger as of Perl version
992C<5.8.6> and debugger version C<1.2.8>.
993
994=cut
995
996BEGIN {
997 # ensure we can share our non-threaded variables or no-op
998 if ($ENV{PERL5DB_THREADED}) {
999 require threads;
1000 require threads::shared;
1001 import threads::shared qw(share);
1002 $DBGR;
1003 share(\$DBGR);
1004 lock($DBGR);
1005 print "Threads support enabled\n";
1006 } else {
1007 *lock = sub(*) {};
1008 *share = sub(*) {};
1009 }
1010}
1011
69893cff
RGS
1012# This would probably be better done with "use vars", but that wasn't around
1013# when this code was originally written. (Neither was "use strict".) And on
1014# the principle of not fiddling with something that was working, this was
1015# left alone.
1016warn( # Do not ;-)
2cbb2ee1 1017 # These variables control the execution of 'dumpvar.pl'.
69893cff
RGS
1018 $dumpvar::hashDepth,
1019 $dumpvar::arrayDepth,
1020 $dumpvar::dumpDBFiles,
1021 $dumpvar::dumpPackages,
1022 $dumpvar::quoteHighBit,
1023 $dumpvar::printUndef,
1024 $dumpvar::globPrint,
1025 $dumpvar::usageOnly,
1026
1027 # used to save @ARGV and extract any debugger-related flags.
1028 @ARGS,
1029
1030 # used to control die() reporting in diesignal()
1031 $Carp::CarpLevel,
1032
1033 # used to prevent multiple entries to diesignal()
1034 # (if for instance diesignal() itself dies)
1035 $panic,
1036
1037 # used to prevent the debugger from running nonstop
1038 # after a restart
1039 $second_time,
1040 )
1041 if 0;
d338d6fe 1042
2cbb2ee1
RGS
1043foreach my $k (keys (%INC)) {
1044 &share(\$main::{'_<'.$filename});
1045};
1046
54d04a52 1047# Command-line + PERLLIB:
69893cff 1048# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
1049@ini_INC = @INC;
1050
69893cff
RGS
1051# This was an attempt to clear out the previous values of various
1052# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
1053# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1054
69893cff
RGS
1055# We set these variables to safe values. We don't want to blindly turn
1056# off warnings, because other packages may still want them.
e22ea7cc
RF
1057$trace = $signal = $single = 0; # Uninitialized warning suppression
1058 # (local $^W cannot help - other packages!).
69893cff
RGS
1059
1060# Default to not exiting when program finishes; print the return
1061# value when the 'r' command is used to return from a subroutine.
55497cff 1062$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 1063
69893cff
RGS
1064=head1 OPTION PROCESSING
1065
1066The debugger's options are actually spread out over the debugger itself and
1067C<dumpvar.pl>; some of these are variables to be set, while others are
1068subs to be called with a value. To try to make this a little easier to
1069manage, the debugger uses a few data structures to define what options
1070are legal and how they are to be processed.
1071
1072First, the C<@options> array defines the I<names> of all the options that
1073are to be accepted.
1074
1075=cut
1076
1077@options = qw(
e22ea7cc
RF
1078 CommandSet
1079 hashDepth arrayDepth dumpDepth
1080 DumpDBFiles DumpPackages DumpReused
1081 compactDump veryCompact quote
1082 HighBit undefPrint globPrint
1083 PrintRet UsageOnly frame
1084 AutoTrace TTY noTTY
1085 ReadLine NonStop LineInfo
1086 maxTraceLen recallCommand ShellBang
1087 pager tkRunning ornaments
1088 signalLevel warnLevel dieLevel
1089 inhibit_exit ImmediateStop bareStringify
1090 CreateTTY RemotePort windowSize
1091 DollarCaretP OnlyAssertions WarnAssertions
1092);
d12a4851
JH
1093
1094@RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1095
69893cff
RGS
1096=pod
1097
1098Second, C<optionVars> lists the variables that each option uses to save its
1099state.
1100
1101=cut
1102
1103%optionVars = (
e22ea7cc
RF
1104 hashDepth => \$dumpvar::hashDepth,
1105 arrayDepth => \$dumpvar::arrayDepth,
1106 CommandSet => \$CommandSet,
1107 DumpDBFiles => \$dumpvar::dumpDBFiles,
1108 DumpPackages => \$dumpvar::dumpPackages,
1109 DumpReused => \$dumpvar::dumpReused,
1110 HighBit => \$dumpvar::quoteHighBit,
1111 undefPrint => \$dumpvar::printUndef,
1112 globPrint => \$dumpvar::globPrint,
1113 UsageOnly => \$dumpvar::usageOnly,
1114 CreateTTY => \$CreateTTY,
1115 bareStringify => \$dumpvar::bareStringify,
1116 frame => \$frame,
1117 AutoTrace => \$trace,
1118 inhibit_exit => \$inhibit_exit,
1119 maxTraceLen => \$maxtrace,
1120 ImmediateStop => \$ImmediateStop,
1121 RemotePort => \$remoteport,
1122 windowSize => \$window,
1123 WarnAssertions => \$warnassertions,
69893cff
RGS
1124);
1125
1126=pod
1127
1128Third, C<%optionAction> defines the subroutine to be called to process each
1129option.
1130
1131=cut
1132
1133%optionAction = (
1134 compactDump => \&dumpvar::compactDump,
1135 veryCompact => \&dumpvar::veryCompact,
1136 quote => \&dumpvar::quote,
1137 TTY => \&TTY,
1138 noTTY => \&noTTY,
1139 ReadLine => \&ReadLine,
1140 NonStop => \&NonStop,
1141 LineInfo => \&LineInfo,
1142 recallCommand => \&recallCommand,
1143 ShellBang => \&shellBang,
1144 pager => \&pager,
1145 signalLevel => \&signalLevel,
1146 warnLevel => \&warnLevel,
1147 dieLevel => \&dieLevel,
1148 tkRunning => \&tkRunning,
1149 ornaments => \&ornaments,
1150 RemotePort => \&RemotePort,
1151 DollarCaretP => \&DollarCaretP,
1152 OnlyAssertions=> \&OnlyAssertions,
d12a4851
JH
1153);
1154
69893cff
RGS
1155=pod
1156
1157Last, the C<%optionRequire> notes modules that must be C<require>d if an
1158option is used.
1159
1160=cut
d338d6fe 1161
69893cff
RGS
1162# Note that this list is not complete: several options not listed here
1163# actually require that dumpvar.pl be loaded for them to work, but are
1164# not in the table. A subsequent patch will correct this problem; for
1165# the moment, we're just recommenting, and we are NOT going to change
1166# function.
eda6e075 1167%optionRequire = (
69893cff
RGS
1168 compactDump => 'dumpvar.pl',
1169 veryCompact => 'dumpvar.pl',
1170 quote => 'dumpvar.pl',
e22ea7cc 1171);
69893cff
RGS
1172
1173=pod
1174
1175There are a number of initialization-related variables which can be set
1176by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1177variable. These are:
1178
1179=over 4
1180
1181=item C<$rl> - readline control XXX needs more explanation
1182
1183=item C<$warnLevel> - whether or not debugger takes over warning handling
1184
1185=item C<$dieLevel> - whether or not debugger takes over die handling
1186
1187=item C<$signalLevel> - whether or not debugger takes over signal handling
1188
1189=item C<$pre> - preprompt actions (array reference)
1190
1191=item C<$post> - postprompt actions (array reference)
1192
1193=item C<$pretype>
1194
1195=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1196
1197=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1198
1199=back
1200
1201=cut
d338d6fe
PP
1202
1203# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1204$rl = 1 unless defined $rl;
1205$warnLevel = 1 unless defined $warnLevel;
1206$dieLevel = 1 unless defined $dieLevel;
1207$signalLevel = 1 unless defined $signalLevel;
1208$pre = [] unless defined $pre;
1209$post = [] unless defined $post;
1210$pretype = [] unless defined $pretype;
1211$CreateTTY = 3 unless defined $CreateTTY;
1212$CommandSet = '580' unless defined $CommandSet;
1213
2cbb2ee1
RGS
1214share($rl);
1215share($warnLevel);
1216share($dieLevel);
1217share($signalLevel);
1218share($pre);
1219share($post);
1220share($pretype);
1221share($rl);
1222share($CreateTTY);
1223share($CommandSet);
1224
69893cff
RGS
1225=pod
1226
1227The default C<die>, C<warn>, and C<signal> handlers are set up.
1228
1229=cut
055fd3a9 1230
d338d6fe
PP
1231warnLevel($warnLevel);
1232dieLevel($dieLevel);
1233signalLevel($signalLevel);
055fd3a9 1234
69893cff
RGS
1235=pod
1236
1237The pager to be used is needed next. We try to get it from the
1238environment first. if it's not defined there, we try to find it in
1239the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1240then call the C<pager()> function to save the pager name.
1241
1242=cut
1243
1244# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1245pager(
e22ea7cc 1246
69893cff 1247 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1248 defined $ENV{PAGER}
1249 ? $ENV{PAGER}
69893cff
RGS
1250
1251 # If not, see if Config.pm defines it.
e22ea7cc
RF
1252 : eval { require Config }
1253 && defined $Config::Config{pager}
1254 ? $Config::Config{pager}
69893cff
RGS
1255
1256 # If not, fall back to 'more'.
e22ea7cc
RF
1257 : 'more'
1258 )
1259 unless defined $pager;
69893cff
RGS
1260
1261=pod
1262
1263We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1264recall character (C<!> unless otherwise defined) and the shell escape
1265character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1266neither works in the debugger at the moment.
1267
1268=cut
1269
055fd3a9 1270setman();
69893cff
RGS
1271
1272# Set up defaults for command recall and shell escape (note:
1273# these currently don't work in linemode debugging).
d338d6fe 1274&recallCommand("!") unless defined $prc;
69893cff
RGS
1275&shellBang("!") unless defined $psh;
1276
1277=pod
1278
1279We then set up the gigantic string containing the debugger help.
1280We also set the limit on the number of arguments we'll display during a
1281trace.
1282
1283=cut
1284
04e43a21 1285sethelp();
69893cff
RGS
1286
1287# If we didn't get a default for the length of eval/stack trace args,
1288# set it here.
1d06cb2d 1289$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1290
1291=head2 SETTING UP THE DEBUGGER GREETING
1292
be9a9b1d 1293The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1294running, and whether the current debugger is the primary or a child.
1295
1296If we are the primary, we just hang onto our pid so we'll have it when
1297or if we start a child debugger. If we are a child, we'll set things up
1298so we'll have a unique greeting and so the parent will give us our own
1299TTY later.
1300
1301We save the current contents of the C<PERLDB_PIDS> environment variable
1302because we mess around with it. We'll also need to hang onto it because
1303we'll need it if we restart.
1304
1305Child debuggers make a label out of the current PID structure recorded in
1306PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1307yet so the parent will give them one later via C<resetterm()>.
1308
1309=cut
1310
e22ea7cc 1311# Save the current contents of the environment; we're about to
69893cff 1312# much with it. We'll need this if we have to restart.
f1583d8f 1313$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1314
e22ea7cc
RF
1315if ( defined $ENV{PERLDB_PIDS} ) {
1316
69893cff 1317 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1318 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1319 # a term yet so the parent will give us one later via resetterm().
e22ea7cc
RF
1320 $pids = "[$ENV{PERLDB_PIDS}]";
1321 $ENV{PERLDB_PIDS} .= "->$$";
1322 $term_pid = -1;
69893cff
RGS
1323} ## end if (defined $ENV{PERLDB_PIDS...
1324else {
e22ea7cc
RF
1325
1326 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1327 # child debugger, and mark us as the parent, so we'll know to set up
1328 # more TTY's is we have to.
1329 $ENV{PERLDB_PIDS} = "$$";
e22ea7cc
RF
1330 $pids = "{pid=$$}";
1331 $term_pid = $$;
f1583d8f 1332}
69893cff 1333
f1583d8f 1334$pidprompt = '';
69893cff
RGS
1335
1336# Sets up $emacs as a synonym for $slave_editor.
1337*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1338
1339=head2 READING THE RC FILE
1340
1341The debugger will read a file of initialization options if supplied. If
1342running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1343
1344=cut
1345
1346# As noted, this test really doesn't check accurately that the debugger
1347# is running at a terminal or not.
d338d6fe 1348
e22ea7cc
RF
1349if ( -e "/dev/tty" ) { # this is the wrong metric!
1350 $rcfile = ".perldb";
1351}
69893cff
RGS
1352else {
1353 $rcfile = "perldb.ini";
d338d6fe
PP
1354}
1355
69893cff
RGS
1356=pod
1357
1358The debugger does a safety test of the file to be read. It must be owned
1359either by the current user or root, and must only be writable by the owner.
1360
1361=cut
1362
1363# This wraps a safety test around "do" to read and evaluate the init file.
1364#
055fd3a9
GS
1365# This isn't really safe, because there's a race
1366# between checking and opening. The solution is to
1367# open and fstat the handle, but then you have to read and
1368# eval the contents. But then the silly thing gets
69893cff
RGS
1369# your lexical scope, which is unfortunate at best.
1370sub safe_do {
055fd3a9
GS
1371 my $file = shift;
1372
1373 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1374 local $SIG{__WARN__};
1375 local $SIG{__DIE__};
055fd3a9 1376
e22ea7cc 1377 unless ( is_safe_file($file) ) {
69893cff 1378 CORE::warn <<EO_GRIPE;
055fd3a9
GS
1379perldb: Must not source insecure rcfile $file.
1380 You or the superuser must be the owner, and it must not
69893cff 1381 be writable by anyone but its owner.
055fd3a9 1382EO_GRIPE
69893cff
RGS
1383 return;
1384 } ## end unless (is_safe_file($file...
055fd3a9
GS
1385
1386 do $file;
1387 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1388} ## end sub safe_do
055fd3a9 1389
69893cff
RGS
1390# This is the safety test itself.
1391#
055fd3a9
GS
1392# Verifies that owner is either real user or superuser and that no
1393# one but owner may write to it. This function is of limited use
1394# when called on a path instead of upon a handle, because there are
1395# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1396# eventually accessed is the same as the one tested.
055fd3a9
GS
1397# Assumes that the file's existence is not in doubt.
1398sub is_safe_file {
1399 my $path = shift;
69893cff 1400 stat($path) || return; # mysteriously vaporized
e22ea7cc 1401 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1402
1403 return 0 if $uid != 0 && $uid != $<;
1404 return 0 if $mode & 022;
1405 return 1;
69893cff 1406} ## end sub is_safe_file
055fd3a9 1407
69893cff 1408# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1409# exists, we safely do it.
1410if ( -f $rcfile ) {
055fd3a9 1411 safe_do("./$rcfile");
69893cff 1412}
e22ea7cc 1413
69893cff 1414# If there isn't one here, try the user's home directory.
e22ea7cc 1415elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1416 safe_do("$ENV{HOME}/$rcfile");
1417}
e22ea7cc 1418
69893cff 1419# Else try the login directory.
e22ea7cc 1420elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1421 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1422}
1423
69893cff 1424# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1425if ( defined $ENV{PERLDB_OPTS} ) {
1426 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1427}
1428
69893cff
RGS
1429=pod
1430
1431The last thing we do during initialization is determine which subroutine is
1432to be used to obtain a new terminal when a new debugger is started. Right now,
1433the debugger only handles X Windows and OS/2.
1434
1435=cut
1436
1437# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1438# Works if you're running an xterm or xterm-like window, or you're on
1439# OS/2. This may need some expansion: for instance, this doesn't handle
e22ea7cc
RF
1440# OS X Terminal windows.
1441
1442if (
1443 not defined &get_fork_TTY # no routine exists,
1444 and defined $ENV{TERM} # and we know what kind
1445 # of terminal this is,
1446 and $ENV{TERM} eq 'xterm' # and it's an xterm,
7fddc82f
RF
1447# and defined $ENV{WINDOWID} # and we know what window this is, <- wrong metric
1448 and defined $ENV{DISPLAY} # and what display it's on,
1449 )
69893cff 1450{
e22ea7cc 1451 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
69893cff 1452} ## end if (not defined &get_fork_TTY...
e22ea7cc
RF
1453elsif ( $^O eq 'os2' ) { # If this is OS/2,
1454 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
f1583d8f 1455}
e22ea7cc 1456
dbb46cec
DQ
1457# untaint $^O, which may have been tainted by the last statement.
1458# see bug [perl #24674]
e22ea7cc
RF
1459$^O =~ m/^(.*)\z/;
1460$^O = $1;
f1583d8f 1461
d12a4851 1462# Here begin the unreadable code. It needs fixing.
055fd3a9 1463
69893cff
RGS
1464=head2 RESTART PROCESSING
1465
1466This section handles the restart command. When the C<R> command is invoked, it
1467tries to capture all of the state it can into environment variables, and
1468then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1469if C<PERLDB_RESTART> is there; if so, we reload all the information that
1470the R command stuffed into the environment variables.
1471
1472 PERLDB_RESTART - flag only, contains no restart data itself.
1473 PERLDB_HIST - command history, if it's available
1474 PERLDB_ON_LOAD - breakpoints set by the rc file
1475 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1476 PERLDB_VISITED - files that had breakpoints
1477 PERLDB_FILE_... - breakpoints for a file
1478 PERLDB_OPT - active options
1479 PERLDB_INC - the original @INC
1480 PERLDB_PRETYPE - preprompt debugger actions
1481 PERLDB_PRE - preprompt Perl code
1482 PERLDB_POST - post-prompt Perl code
1483 PERLDB_TYPEAHEAD - typeahead captured by readline()
1484
1485We chug through all these variables and plug the values saved in them
1486back into the appropriate spots in the debugger.
1487
1488=cut
1489
e22ea7cc
RF
1490if ( exists $ENV{PERLDB_RESTART} ) {
1491
69893cff 1492 # We're restarting, so we don't need the flag that says to restart anymore.
e22ea7cc
RF
1493 delete $ENV{PERLDB_RESTART};
1494
1495 # $restart = 1;
1496 @hist = get_list('PERLDB_HIST');
1497 %break_on_load = get_list("PERLDB_ON_LOAD");
1498 %postponed = get_list("PERLDB_POSTPONE");
69893cff 1499
2cbb2ee1
RGS
1500 share(@hist);
1501 share(@truehist);
1502 share(%break_on_load);
1503 share(%postponed);
1504
69893cff 1505 # restore breakpoints/actions
e22ea7cc
RF
1506 my @had_breakpoints = get_list("PERLDB_VISITED");
1507 for ( 0 .. $#had_breakpoints ) {
1508 my %pf = get_list("PERLDB_FILE_$_");
1509 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1510 }
69893cff
RGS
1511
1512 # restore options
e22ea7cc
RF
1513 my %opt = get_list("PERLDB_OPT");
1514 my ( $opt, $val );
1515 while ( ( $opt, $val ) = each %opt ) {
1516 $val =~ s/[\\\']/\\$1/g;
1517 parse_options("$opt'$val'");
1518 }
69893cff
RGS
1519
1520 # restore original @INC
e22ea7cc
RF
1521 @INC = get_list("PERLDB_INC");
1522 @ini_INC = @INC;
1523
1524 # return pre/postprompt actions and typeahead buffer
1525 $pretype = [ get_list("PERLDB_PRETYPE") ];
1526 $pre = [ get_list("PERLDB_PRE") ];
1527 $post = [ get_list("PERLDB_POST") ];
1528 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1529} ## end if (exists $ENV{PERLDB_RESTART...
1530
1531=head2 SETTING UP THE TERMINAL
1532
1533Now, we'll decide how the debugger is going to interact with the user.
1534If there's no TTY, we set the debugger to run non-stop; there's not going
1535to be anyone there to enter commands.
1536
1537=cut
54d04a52 1538
d338d6fe 1539if ($notty) {
69893cff 1540 $runnonstop = 1;
2cbb2ee1 1541 share($runnonstop);
69893cff 1542}
d12a4851 1543
69893cff
RGS
1544=pod
1545
1546If there is a TTY, we have to determine who it belongs to before we can
1547proceed. If this is a slave editor or graphical debugger (denoted by
1548the first command-line switch being '-emacs'), we shift this off and
1549set C<$rl> to 0 (XXX ostensibly to do straight reads).
1550
1551=cut
1552
1553else {
e22ea7cc 1554
69893cff
RGS
1555 # Is Perl being run from a slave editor or graphical debugger?
1556 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1557 $slave_editor =
1558 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1559 $rl = 0, shift(@main::ARGV) if $slave_editor;
1560
1561 #require Term::ReadLine;
d12a4851 1562
69893cff
RGS
1563=pod
1564
1565We then determine what the console should be on various systems:
1566
1567=over 4
1568
1569=item * Cygwin - We use C<stdin> instead of a separate device.
1570
1571=cut
1572
e22ea7cc
RF
1573 if ( $^O eq 'cygwin' ) {
1574
69893cff
RGS
1575 # /dev/tty is binary. use stdin for textmode
1576 undef $console;
1577 }
1578
1579=item * Unix - use C</dev/tty>.
1580
1581=cut
1582
e22ea7cc 1583 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1584 $console = "/dev/tty";
1585 }
1586
1587=item * Windows or MSDOS - use C<con>.
1588
1589=cut
1590
e22ea7cc 1591 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1592 $console = "con";
1593 }
1594
1595=item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
be9a9b1d
AT
1596Console> if not.
1597
1598Note 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
1599
1600=cut
1601
e22ea7cc
RF
1602 elsif ( $^O eq 'MacOS' ) {
1603 if ( $MacPerl::Version !~ /MPW/ ) {
1604 $console =
1605 "Dev:Console:Perl Debug"; # Separate window for application
69893cff
RGS
1606 }
1607 else {
1608 $console = "Dev:Console";
1609 }
1610 } ## end elsif ($^O eq 'MacOS')
1611
1612=item * VMS - use C<sys$command>.
1613
1614=cut
1615
1616 else {
e22ea7cc 1617
69893cff
RGS
1618 # everything else is ...
1619 $console = "sys\$command";
d12a4851 1620 }
69893cff
RGS
1621
1622=pod
1623
1624=back
1625
1626Several other systems don't use a specific console. We C<undef $console>
1627for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1628with a slave editor, Epoc).
1629
1630=cut
d12a4851 1631
e22ea7cc
RF
1632 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1633
69893cff 1634 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1635 $console = undef;
1636 }
1637
1638 if ( $^O eq 'NetWare' ) {
d12a4851 1639
69893cff
RGS
1640 # /dev/tty is binary. use stdin for textmode
1641 $console = undef;
1642 }
d12a4851 1643
69893cff
RGS
1644 # In OS/2, we need to use STDIN to get textmode too, even though
1645 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1646 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1647 { # In OS/2
1648 $console = undef;
1649 }
1650
1651 # EPOC also falls into the 'got to use STDIN' camp.
1652 if ( $^O eq 'epoc' ) {
1653 $console = undef;
1654 }
d12a4851 1655
69893cff
RGS
1656=pod
1657
1658If there is a TTY hanging around from a parent, we use that as the console.
1659
1660=cut
1661
e22ea7cc 1662 $console = $tty if defined $tty;
d12a4851 1663
69893cff
RGS
1664=head2 SOCKET HANDLING
1665
1666The debugger is capable of opening a socket and carrying out a debugging
1667session over the socket.
1668
1669If C<RemotePort> was defined in the options, the debugger assumes that it
1670should try to start a debugging session on that port. It builds the socket
1671and then tries to connect the input and output filehandles to it.
1672
1673=cut
1674
1675 # Handle socket stuff.
e22ea7cc
RF
1676
1677 if ( defined $remoteport ) {
1678
69893cff
RGS
1679 # If RemotePort was defined in the options, connect input and output
1680 # to the socket.
e22ea7cc
RF
1681 require IO::Socket;
1682 $OUT = new IO::Socket::INET(
1683 Timeout => '10',
1684 PeerAddr => $remoteport,
1685 Proto => 'tcp',
69893cff 1686 );
e22ea7cc
RF
1687 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1688 $IN = $OUT;
69893cff
RGS
1689 } ## end if (defined $remoteport)
1690
1691=pod
1692
1693If no C<RemotePort> was defined, and we want to create a TTY on startup,
1694this is probably a situation where multiple debuggers are running (for example,
1695a backticked command that starts up another debugger). We create a new IN and
1696OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1697and if we can.
1698
1699=cut
1700
1701 # Non-socket.
1702 else {
e22ea7cc 1703
69893cff
RGS
1704 # Two debuggers running (probably a system or a backtick that invokes
1705 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1706 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1707 # know how, and we can.
e22ea7cc
RF
1708 create_IN_OUT(4) if $CreateTTY & 4;
1709 if ($console) {
1710
69893cff
RGS
1711 # If we have a console, check to see if there are separate ins and
1712 # outs to open. (They are assumed identiical if not.)
1713
e22ea7cc
RF
1714 my ( $i, $o ) = split /,/, $console;
1715 $o = $i unless defined $o;
69893cff 1716
69893cff 1717 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1718 open( IN, "+<$i" )
1719 || open( IN, "<$i" )
1720 || open( IN, "<&STDIN" );
1721
69893cff
RGS
1722 # read/write/create/clobber out, or write/create/clobber out,
1723 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1724 open( OUT, "+>$o" )
1725 || open( OUT, ">$o" )
1726 || open( OUT, ">&STDERR" )
1727 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1728
1729 } ## end if ($console)
1730 elsif ( not defined $console ) {
1731
1732 # No console. Open STDIN.
1733 open( IN, "<&STDIN" );
1734
1735 # merge with STDERR, or with STDOUT.
1736 open( OUT, ">&STDERR" )
1737 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1738 $console = 'STDIN/OUT';
69893cff
RGS
1739 } ## end elsif (not defined $console)
1740
1741 # Keep copies of the filehandles so that when the pager runs, it
1742 # can close standard input without clobbering ours.
e22ea7cc
RF
1743 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1744 } ## end elsif (from if(defined $remoteport))
1745
1746 # Unbuffer DB::OUT. We need to see responses right away.
1747 my $previous = select($OUT);
1748 $| = 1; # for DB::OUT
1749 select($previous);
1750
1751 # Line info goes to debugger output unless pointed elsewhere.
1752 # Pointing elsewhere makes it possible for slave editors to
1753 # keep track of file and position. We have both a filehandle
1754 # and a I/O description to keep track of.
1755 $LINEINFO = $OUT unless defined $LINEINFO;
1756 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1
RGS
1757 # share($LINEINFO); # <- unable to share globs
1758 share($lineinfo); #
e22ea7cc 1759
69893cff
RGS
1760=pod
1761
1762To finish initialization, we show the debugger greeting,
1763and then call the C<afterinit()> subroutine if there is one.
1764
1765=cut
d12a4851 1766
e22ea7cc
RF
1767 # Show the debugger greeting.
1768 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1769 unless ($runnonstop) {
1770 local $\ = '';
1771 local $, = '';
1772 if ( $term_pid eq '-1' ) {
1773 print $OUT "\nDaughter DB session started...\n";
1774 }
1775 else {
1776 print $OUT "\nLoading DB routines from $header\n";
1777 print $OUT (
1778 "Editor support ",
1779 $slave_editor ? "enabled" : "available", ".\n"
1780 );
1781 print $OUT
69893cff
RGS
1782"\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1783 } ## end else [ if ($term_pid eq '-1')
1784 } ## end unless ($runnonstop)
1785} ## end else [ if ($notty)
1786
1787# XXX This looks like a bug to me.
1788# Why copy to @ARGS and then futz with @args?
d338d6fe
PP
1789@ARGS = @ARGV;
1790for (@args) {
69893cff
RGS
1791 # Make sure backslashes before single quotes are stripped out, and
1792 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1793 # s/\'/\\\'/g; # removed while not justified understandably
1794 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
d338d6fe
PP
1795}
1796
e22ea7cc 1797# If there was an afterinit() sub defined, call it. It will get
69893cff 1798# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1799if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1800 &afterinit();
d338d6fe 1801}
e22ea7cc 1802
69893cff 1803# Inform us about "Stack dump during die enabled ..." in dieLevel().
43aed9ee
IZ
1804$I_m_init = 1;
1805
d338d6fe
PP
1806############################################################ Subroutines
1807
69893cff
RGS
1808=head1 SUBROUTINES
1809
1810=head2 DB
1811
1812This gigantic subroutine is the heart of the debugger. Called before every
1813statement, its job is to determine if a breakpoint has been reached, and
1814stop if so; read commands from the user, parse them, and execute
1815them, and hen send execution off to the next statement.
1816
1817Note that the order in which the commands are processed is very important;
1818some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1819to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1820but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1821see what's happening in any given command.
1822
1823=cut
1824
d338d6fe 1825sub DB {
69893cff 1826
2cbb2ee1
RGS
1827 # lock the debugger and get the thread id for the prompt
1828 lock($DBGR);
1829 my $tid;
1830 if ($ENV{PERL5DB_THREADED}) {
1831 $tid = eval { "[".threads->self->tid."]" };
1832 }
1833
69893cff 1834 # Check for whether we should be running continuously or not.
36477c24 1835 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1836 if ( $single and not $second_time++ ) {
1837
69893cff 1838 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1839 if ($runnonstop) { # Disable until signal
1840 # If there's any call stack in place, turn off single
1841 # stepping into subs throughout the stack.
1842 for ( $i = 0 ; $i <= $stack_depth ; ) {
1843 $stack[ $i++ ] &= ~1;
1844 }
1845
69893cff 1846 # And we are now no longer in single-step mode.
e22ea7cc 1847 $single = 0;
69893cff
RGS
1848
1849 # If we simply returned at this point, we wouldn't get
1850 # the trace info. Fall on through.
e22ea7cc 1851 # return;
69893cff
RGS
1852 } ## end if ($runnonstop)
1853
e22ea7cc
RF
1854 elsif ($ImmediateStop) {
1855
1856 # We are supposed to stop here; XXX probably a break.
1857 $ImmediateStop = 0; # We've processed it; turn it off
1858 $signal = 1; # Simulate an interrupt to force
1859 # us into the command loop
69893cff
RGS
1860 }
1861 } ## end if ($single and not $second_time...
1862
1863 # If we're in single-step mode, or an interrupt (real or fake)
1864 # has occurred, turn off non-stop mode.
1865 $runnonstop = 0 if $single or $signal;
1866
1867 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1868 # The code being debugged may have altered them.
d338d6fe 1869 &save;
69893cff
RGS
1870
1871 # Since DB::DB gets called after every line, we can use caller() to
1872 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1873 # caller is returning all the extra information when called from the
69893cff 1874 # debugger.
e22ea7cc 1875 local ( $package, $filename, $line ) = caller;
471505cc 1876 local $filename_ini = $filename;
69893cff
RGS
1877
1878 # set up the context for DB::eval, so it can properly execute
1879 # code on behalf of the user. We add the package in so that the
1880 # code is eval'ed in the proper package (not in the debugger!).
1881 local $usercontext =
e22ea7cc 1882 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
69893cff
RGS
1883
1884 # Create an alias to the active file magical array to simplify
1885 # the code here.
e22ea7cc 1886 local (*dbline) = $main::{ '_<' . $filename };
aa057b67
CN
1887
1888 # we need to check for pseudofiles on Mac OS (these are files
1889 # not attached to a filename, but instead stored in Dev:Pseudo)
e22ea7cc
RF
1890 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1891 $filename_ini = $filename = 'Dev:Pseudo';
1892 *dbline = $main::{ '_<' . $filename };
aa057b67
CN
1893 }
1894
69893cff 1895 # Last line in the program.
471505cc 1896 local $max = $#dbline;
69893cff
RGS
1897
1898 # if we have something here, see if we should break.
e22ea7cc
RF
1899 if ( $dbline{$line}
1900 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1901 {
1902
69893cff 1903 # Stop if the stop criterion says to just stop.
e22ea7cc 1904 if ( $stop eq '1' ) {
69893cff
RGS
1905 $signal |= 1;
1906 }
e22ea7cc 1907
69893cff
RGS
1908 # It's a conditional stop; eval it in the user's context and
1909 # see if we should stop. If so, remove the one-time sigil.
1910 elsif ($stop) {
e22ea7cc 1911 $evalarg = "\$DB::signal |= 1 if do {$stop}";
69893cff
RGS
1912 &eval;
1913 $dbline{$line} =~ s/;9($|\0)/$1/;
1914 }
1915 } ## end if ($dbline{$line} && ...
1916
1917 # Preserve the current stop-or-not, and see if any of the W
1918 # (watch expressions) has changed.
36477c24 1919 my $was_signal = $signal;
69893cff
RGS
1920
1921 # If we have any watch expressions ...
e22ea7cc
RF
1922 if ( $trace & 2 ) {
1923 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1924 $evalarg = $to_watch[$n];
1925 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1926
1927 # Fix context DB::eval() wants to return an array, but
1928 # we need a scalar here.
e22ea7cc
RF
1929 my ($val) = join( "', '", &eval );
1930 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1931
1932 # Did it change?
e22ea7cc
RF
1933 if ( $val ne $old_watch[$n] ) {
1934
69893cff 1935 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1936 $signal = 1;
1937 print $OUT <<EOP;
405ff068 1938Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1939 old value:\t$old_watch[$n]
1940 new value:\t$val
6027b9a3 1941EOP
e22ea7cc 1942 $old_watch[$n] = $val;
69893cff
RGS
1943 } ## end if ($val ne $old_watch...
1944 } ## end for (my $n = 0 ; $n <= ...
1945 } ## end if ($trace & 2)
1946
1947=head2 C<watchfunction()>
1948
1949C<watchfunction()> is a function that can be defined by the user; it is a
1950function which will be run on each entry to C<DB::DB>; it gets the
1951current package, filename, and line as its parameters.
1952
1953The watchfunction can do anything it likes; it is executing in the
1954debugger's context, so it has access to all of the debugger's internal
1955data structures and functions.
1956
1957C<watchfunction()> can control the debugger's actions. Any of the following
1958will cause the debugger to return control to the user's program after
1959C<watchfunction()> executes:
1960
1961=over 4
1962
be9a9b1d
AT
1963=item *
1964
1965Returning a false value from the C<watchfunction()> itself.
1966
1967=item *
1968
1969Altering C<$single> to a false value.
1970
1971=item *
69893cff 1972
be9a9b1d 1973Altering C<$signal> to a false value.
69893cff 1974
be9a9b1d 1975=item *
69893cff 1976
be9a9b1d 1977Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1978check for C<watchfunction()>. This can be done with
1979
1980 $trace &= ~4;
1981
1982=back
1983
1984=cut
1985
e22ea7cc 1986 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1987 # current package, filename, and line. The function executes in
1988 # the DB:: package.
e22ea7cc
RF
1989 if ( $trace & 4 ) { # User-installed watch
1990 return
1991 if watchfunction( $package, $filename, $line )
1992 and not $single
1993 and not $was_signal
1994 and not( $trace & ~4 );
69893cff
RGS
1995 } ## end if ($trace & 4)
1996
e22ea7cc 1997 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1998 # turn off the signal now.
6027b9a3 1999 $was_signal = $signal;
69893cff
RGS
2000 $signal = 0;
2001
2002=head2 GETTING READY TO EXECUTE COMMANDS
2003
2004The debugger decides to take control if single-step mode is on, the
2005C<t> command was entered, or the user generated a signal. If the program
2006has fallen off the end, we set things up so that entering further commands
2007won't cause trouble, and we say that the program is over.
2008
2009=cut
2010
2011 # Check to see if we should grab control ($single true,
2012 # trace set appropriately, or we got a signal).
e22ea7cc
RF
2013 if ( $single || ( $trace & 1 ) || $was_signal ) {
2014
69893cff 2015 # Yes, grab control.
e22ea7cc
RF
2016 if ($slave_editor) {
2017
69893cff 2018 # Tell the editor to update its position.
e22ea7cc
RF
2019 $position = "\032\032$filename:$line:0\n";
2020 print_lineinfo($position);
2021 }
69893cff
RGS
2022
2023=pod
2024
2025Special check: if we're in package C<DB::fake>, we've gone through the
2026C<END> block at least once. We set up everything so that we can continue
2027to enter commands and have a valid context to be in.
2028
2029=cut
2030
e22ea7cc 2031 elsif ( $package eq 'DB::fake' ) {
69893cff 2032
69893cff 2033 # Fallen off the end already.
e22ea7cc
RF
2034 $term || &setterm;
2035 print_help(<<EOP);
405ff068
IZ
2036Debugged program terminated. Use B<q> to quit or B<R> to restart,
2037 use B<O> I<inhibit_exit> to avoid stopping after program termination,
2038 B<h q>, B<h R> or B<h O> to get additional info.
2039EOP
e22ea7cc 2040
69893cff 2041 # Set the DB::eval context appropriately.
e22ea7cc
RF
2042 $package = 'main';
2043 $usercontext =
2044 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2045 . "package $package;"; # this won't let them modify, alas
69893cff 2046 } ## end elsif ($package eq 'DB::fake')
e219e2fb 2047
69893cff 2048=pod
e219e2fb 2049
69893cff
RGS
2050If the program hasn't finished executing, we scan forward to the
2051next executable line, print that out, build the prompt from the file and line
2052number information, and print that.
e219e2fb 2053
69893cff
RGS
2054=cut
2055
e22ea7cc
RF
2056 else {
2057
69893cff
RGS
2058 # Still somewhere in the midst of execution. Set up the
2059 # debugger prompt.
2060 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 2061 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
2062 #module names)
2063
e22ea7cc
RF
2064 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2065 $prefix .= "$sub($filename:";
2066 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2067
2068 # Break up the prompt if it's really long.
e22ea7cc
RF
2069 if ( length($prefix) > 30 ) {
2070 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2071 $prefix = "";
2072 $infix = ":\t";
2073 }
2074 else {
2075 $infix = "):\t";
2076 $position = "$prefix$line$infix$dbline[$line]$after";
2077 }
69893cff
RGS
2078
2079 # Print current line info, indenting if necessary.
e22ea7cc
RF
2080 if ($frame) {
2081 print_lineinfo( ' ' x $stack_depth,
2082 "$line:\t$dbline[$line]$after" );
2083 }
2084 else {
2085 print_lineinfo($position);
2086 }
69893cff
RGS
2087
2088 # Scan forward, stopping at either the end or the next
2089 # unbreakable line.
e22ea7cc
RF
2090 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2091 { #{ vi
69893cff
RGS
2092
2093 # Drop out on null statements, block closers, and comments.
2094 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2095
2096 # Drop out if the user interrupted us.
2097 last if $signal;
2098
2099 # Append a newline if the line doesn't have one. Can happen
2100 # in eval'ed text, for instance.
e22ea7cc 2101 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2102
2103 # Next executable line.
2104 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2105 $position .= $incr_pos;
2106 if ($frame) {
e22ea7cc 2107
69893cff 2108 # Print it indented if tracing is on.
e22ea7cc
RF
2109 print_lineinfo( ' ' x $stack_depth,
2110 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2111 }
2112 else {
2113 print_lineinfo($incr_pos);
2114 }
2115 } ## end for ($i = $line + 1 ; $i...
2116 } ## end else [ if ($slave_editor)
2117 } ## end if ($single || ($trace...
2118
2119=pod
2120
2121If there's an action to be executed for the line we stopped at, execute it.
2122If there are any preprompt actions, execute those as well.
e219e2fb
RF
2123
2124=cut
2125
69893cff
RGS
2126 # If there's an action, do it now.
2127 $evalarg = $action, &eval if $action;
e219e2fb 2128
69893cff
RGS
2129 # Are we nested another level (e.g., did we evaluate a function
2130 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2131 if ( $single || $was_signal ) {
2132
69893cff 2133 # Yes, go down a level.
e22ea7cc 2134 local $level = $level + 1;
69893cff
RGS
2135
2136 # Do any pre-prompt actions.
e22ea7cc
RF
2137 foreach $evalarg (@$pre) {
2138 &eval;
2139 }
69893cff
RGS
2140
2141 # Complain about too much recursion if we passed the limit.
e22ea7cc 2142 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2143 if $single & 4;
2144
2145 # The line we're currently on. Set $incr to -1 to stay here
2146 # until we get a command that tells us to advance.
e22ea7cc
RF
2147 $start = $line;
2148 $incr = -1; # for backward motion.
69893cff
RGS
2149
2150 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2151 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2152
2153=head2 WHERE ARE WE?
2154
2155XXX Relocate this section?
2156
2157The debugger normally shows the line corresponding to the current line of
2158execution. Sometimes, though, we want to see the next line, or to move elsewhere
2159in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2160
be9a9b1d
AT
2161C<$incr> controls by how many lines the I<current> line should move forward
2162after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2163line shouldn't change.
2164
be9a9b1d 2165C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2166move forwards or backwards from when doing an C<L> or C<-> command.
2167
2168C<$max> tells the debugger where the last line of the current file is. It's
2169used to terminate loops most often.
2170
2171=head2 THE COMMAND LOOP
2172
2173Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2174in two parts:
2175
2176=over 4
2177
be9a9b1d
AT
2178=item *
2179
2180The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2181reads a command and then executes it.
2182
be9a9b1d
AT
2183=item *
2184
2185The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2186is wholly contained inside the C<CMD> block and only executes a command.
2187Used to handle commands running inside a pager.
2188
2189=back
2190
2191So why have two labels to restart the loop? Because sometimes, it's easier to
2192have a command I<generate> another command and then re-execute the loop to do
2193the new command. This is faster, but perhaps a bit more convoluted.
2194
2195=cut
2196
2197 # The big command dispatch loop. It keeps running until the
2198 # user yields up control again.
2199 #
2200 # If we have a terminal for input, and we get something back
2201 # from readline(), keep on processing.
e22ea7cc
RF
2202 CMD:
2203 while (
2204
69893cff 2205 # We have a terminal, or can get one ...
e22ea7cc
RF
2206 ( $term || &setterm ),
2207
69893cff 2208 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2209 ( $term_pid == $$ or resetterm(1) ),
2210
69893cff 2211 # ... and we got a line of command input ...
e22ea7cc
RF
2212 defined(
2213 $cmd = &readline(
2cbb2ee1 2214 "$pidprompt $tid DB"
e22ea7cc
RF
2215 . ( '<' x $level )
2216 . ( $#hist + 1 )
2217 . ( '>' x $level ) . " "
69893cff
RGS
2218 )
2219 )
2220 )
2221 {
e22ea7cc 2222
2cbb2ee1 2223 share($cmd);
69893cff
RGS
2224 # ... try to execute the input as debugger commands.
2225
2226 # Don't stop running.
2227 $single = 0;
2228
2229 # No signal is active.
2230 $signal = 0;
2231
2232 # Handle continued commands (ending with \):
e22ea7cc
RF
2233 $cmd =~ s/\\$/\n/ && do {
2234 $cmd .= &readline(" cont: ");
2235 redo CMD;
2236 };
69893cff
RGS
2237
2238=head4 The null command
2239
be9a9b1d 2240A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2241command out of C<$laststep> (where it was recorded previously), and copy it
2242back into C<$cmd> to be executed below. If there wasn't any previous command,
2243we'll do nothing below (no command will match). If there was, we also save it
2244in the command history and fall through to allow the command parsing to pick
2245it up.
2246
2247=cut
2248
2249 # Empty input means repeat the last command.
e22ea7cc
RF
2250 $cmd =~ /^$/ && ( $cmd = $laststep );
2251 chomp($cmd); # get rid of the annoying extra newline
2252 push( @hist, $cmd ) if length($cmd) > 1;
2253 push( @truehist, $cmd );
2cbb2ee1
RGS
2254 share(@hist);
2255 share(@truehist);
e22ea7cc
RF
2256
2257 # This is a restart point for commands that didn't arrive
2258 # via direct user input. It allows us to 'redo PIPE' to
2259 # re-execute command processing without reading a new command.
69893cff 2260 PIPE: {
e22ea7cc
RF
2261 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2262 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2263 ($i) = split( /\s+/, $cmd );
69893cff
RGS
2264
2265=head3 COMMAND ALIASES
2266
2267The debugger can create aliases for commands (these are stored in the
2268C<%alias> hash). Before a command is executed, the command loop looks it up
2269in the alias hash and substitutes the contents of the alias for the command,
2270completely replacing it.
2271
2272=cut
2273
2274 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2275 if ( $alias{$i} ) {
2276
69893cff
RGS
2277 # Squelch signal handling; we want to keep control here
2278 # if something goes loco during the alias eval.
2279 local $SIG{__DIE__};
2280 local $SIG{__WARN__};
2281
2282 # This is a command, so we eval it in the DEBUGGER's
2283 # scope! Otherwise, we can't see the special debugger
2284 # variables, or get to the debugger's subs. (Well, we
2285 # _could_, but why make it even more complicated?)
2286 eval "\$cmd =~ $alias{$i}";
2287 if ($@) {
2288 local $\ = '';
2289 print $OUT "Couldn't evaluate `$i' alias: $@";
2290 next CMD;
2291 }
2292 } ## end if ($alias{$i})
2293
2294=head3 MAIN-LINE COMMANDS
2295
2296All of these commands work up to and after the program being debugged has
2297terminated.
2298
2299=head4 C<q> - quit
2300
2301Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2302try to execute further, cleaning any restart-related stuff out of the
2303environment, and executing with the last value of C<$?>.
2304
2305=cut
2306
2307 $cmd =~ /^q$/ && do {
2308 $fall_off_end = 1;
2309 clean_ENV();
2310 exit $?;
2311 };
2312
2313=head4 C<t> - trace
2314
2315Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2316
2317=cut
2318
e22ea7cc
RF
2319 $cmd =~ /^t$/ && do {
2320 $trace ^= 1;
2321 local $\ = '';
2322 print $OUT "Trace = "
2323 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2324 next CMD;
2325 };
69893cff
RGS
2326
2327=head4 C<S> - list subroutines matching/not matching a pattern
2328
2329Walks through C<%sub>, checking to see whether or not to print the name.
2330
2331=cut
2332
e22ea7cc 2333 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
69893cff 2334
e22ea7cc 2335 $Srev = defined $2; # Reverse scan?
69893cff
RGS
2336 $Spatt = $3; # The pattern (if any) to use.
2337 $Snocheck = !defined $1; # No args - print all subs.
2338
2339 # Need to make these sane here.
e22ea7cc
RF
2340 local $\ = '';
2341 local $, = '';
69893cff
RGS
2342
2343 # Search through the debugger's magical hash of subs.
2344 # If $nocheck is true, just print the sub name.
2345 # Otherwise, check it against the pattern. We then use
2346 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2347 foreach $subname ( sort( keys %sub ) ) {
2348 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2349 print $OUT $subname, "\n";
2350 }
2351 }
2352 next CMD;
2353 };
69893cff
RGS
2354
2355=head4 C<X> - list variables in current package
2356
2357Since the C<V> command actually processes this, just change this to the
2358appropriate C<V> command and fall through.
2359
2360=cut
2361
e22ea7cc 2362 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2363
2364=head4 C<V> - list variables
2365
2366Uses C<dumpvar.pl> to dump out the current values for selected variables.
2367
2368=cut
2369
2370 # Bare V commands get the currently-being-debugged package
2371 # added.
e22ea7cc
RF
2372 $cmd =~ /^V$/ && do {
2373 $cmd = "V $package";
2374 };
69893cff
RGS
2375
2376 # V - show variables in package.
2377 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
e22ea7cc 2378
69893cff
RGS
2379 # Save the currently selected filehandle and
2380 # force output to debugger's filehandle (dumpvar
2381 # just does "print" for output).
e22ea7cc 2382 local ($savout) = select($OUT);
69893cff
RGS
2383
2384 # Grab package name and variables to dump.
e22ea7cc
RF
2385 $packname = $1;
2386 @vars = split( ' ', $2 );
69893cff
RGS
2387
2388 # If main::dumpvar isn't here, get it.
e22ea7cc
RF
2389 do 'dumpvar.pl' unless defined &main::dumpvar;
2390 if ( defined &main::dumpvar ) {
2391
69893cff
RGS
2392 # We got it. Turn off subroutine entry/exit messages
2393 # for the moment, along with return values.
e22ea7cc
RF
2394 local $frame = 0;
2395 local $doret = -2;
69893cff
RGS
2396
2397 # must detect sigpipe failures - not catching
2398 # then will cause the debugger to die.
2399 eval {
2400 &main::dumpvar(
2401 $packname,
2402 defined $option{dumpDepth}
e22ea7cc
RF
2403 ? $option{dumpDepth}
2404 : -1, # assume -1 unless specified
69893cff 2405 @vars
e22ea7cc
RF
2406 );
2407 };
2408
2409 # The die doesn't need to include the $@, because
2410 # it will automatically get propagated for us.
2411 if ($@) {
2412 die unless $@ =~ /dumpvar print failed/;
2413 }
2414 } ## end if (defined &main::dumpvar)
2415 else {
2416
2417 # Couldn't load dumpvar.
2418 print $OUT "dumpvar.pl not available.\n";
2419 }
69893cff 2420
69893cff 2421 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2422 select($savout);
2423 next CMD;
2424 };
69893cff
RGS
2425
2426=head4 C<x> - evaluate and print an expression
2427
2428Hands the expression off to C<DB::eval>, setting it up to print the value
2429via C<dumpvar.pl> instead of just printing it directly.
2430
2431=cut
2432
e22ea7cc
RF
2433 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2434 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2435
2436 # handle special "x 3 blah" syntax XXX propagate
2437 # doc back to special variables.
e22ea7cc
RF
2438 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2439 $onetimedumpDepth = $1;
2440 }
2441 };
69893cff
RGS
2442
2443=head4 C<m> - print methods
2444
2445Just uses C<DB::methods> to determine what methods are available.
2446
2447=cut
2448
e22ea7cc
RF
2449 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2450 methods($1);
2451 next CMD;
2452 };
69893cff
RGS
2453
2454 # m expr - set up DB::eval to do the work
e22ea7cc
RF
2455 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2456 $onetimeDump = 'methods'; # method output gets used there
2457 };
69893cff
RGS
2458
2459=head4 C<f> - switch files
2460
2461=cut
2462
e22ea7cc
RF
2463 $cmd =~ /^f\b\s*(.*)/ && do {
2464 $file = $1;
2465 $file =~ s/\s+$//;
69893cff
RGS
2466
2467 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2468 if ( !$file ) {
2469 print $OUT
2470 "The old f command is now the r command.\n"; # hint
2471 print $OUT "The new f command switches filenames.\n";
2472 next CMD;
2473 } ## end if (!$file)
69893cff
RGS
2474
2475 # if not in magic file list, try a close match.
e22ea7cc
RF
2476 if ( !defined $main::{ '_<' . $file } ) {
2477 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2478 {
2479 $try = substr( $try, 2 );
2480 print $OUT "Choosing $try matching `$file':\n";
2481 $file = $try;
2482 }
2483 } ## end if (($try) = grep(m#^_<.*$file#...
2484 } ## end if (!defined $main::{ ...
69893cff
RGS
2485
2486 # If not successfully switched now, we failed.
e22ea7cc
RF
2487 if ( !defined $main::{ '_<' . $file } ) {
2488 print $OUT "No file matching `$file' is loaded.\n";
2489 next CMD;
2490 }
69893cff 2491
e22ea7cc
RF
2492 # We switched, so switch the debugger internals around.
2493 elsif ( $file ne $filename ) {
2494 *dbline = $main::{ '_<' . $file };
2495 $max = $#dbline;
2496 $filename = $file;
2497 $start = 1;
2498 $cmd = "l";
2499 } ## end elsif ($file ne $filename)
2500
2501 # We didn't switch; say we didn't.
2502 else {
2503 print $OUT "Already in $file.\n";
2504 next CMD;
2505 }
2506 };
69893cff
RGS
2507
2508=head4 C<.> - return to last-executed line.
2509
2510We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2511and then we look up the line in the magical C<%dbline> hash.
2512
2513=cut
2514
2515 # . command.
e22ea7cc
RF
2516 $cmd =~ /^\.$/ && do {
2517 $incr = -1; # stay at current line
69893cff
RGS
2518
2519 # Reset everything to the old location.
e22ea7cc
RF
2520 $start = $line;
2521 $filename = $filename_ini;
2522 *dbline = $main::{ '_<' . $filename };
2523 $max = $#dbline;
69893cff
RGS
2524
2525 # Now where are we?
e22ea7cc
RF
2526 print_lineinfo($position);
2527 next CMD;
2528 };
69893cff
RGS
2529
2530=head4 C<-> - back one window
2531
2532We change C<$start> to be one window back; if we go back past the first line,
2533we set it to be the first line. We ser C<$incr> to put us back at the
2534currently-executing line, and then put a C<l $start +> (list one window from
2535C<$start>) in C<$cmd> to be executed later.
2536
2537=cut
2538
2539 # - - back a window.
e22ea7cc
RF
2540 $cmd =~ /^-$/ && do {
2541
69893cff 2542 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2543 $start -= $incr + $window + 1;
2544 $start = 1 if $start <= 0;
2545 $incr = $window - 1;
69893cff
RGS
2546
2547 # Generate and execute a "l +" command (handled below).
e22ea7cc
RF
2548 $cmd = 'l ' . ($start) . '+';
2549 };
69893cff
RGS
2550
2551=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>, {, {{>
2552
2553In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2554problems, most notably that the default case of several commands destroying
2555the user's work in setting watchpoints, actions, etc. We wanted, however, to
2556retain the old commands for those who were used to using them or who preferred
2557them. At this point, we check for the new commands and call C<cmd_wrapper> to
2558deal with them instead of processing them in-line.
2559
2560=cut
2561
2562 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2563 # we send them off to the secondary dispatcher (see below).
2cbb2ee1 2564 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
e22ea7cc
RF
2565 &cmd_wrapper( $1, $2, $line );
2566 next CMD;
2567 };
69893cff
RGS
2568
2569=head4 C<y> - List lexicals in higher scope
2570
2571Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2572above the current one and then displays then using C<dumpvar.pl>.
2573
2574=cut
2575
2576 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2577
2578 # See if we've got the necessary support.
2579 eval { require PadWalker; PadWalker->VERSION(0.08) }
2580 or &warn(
2581 $@ =~ /locate/
2582 ? "PadWalker module not found - please install\n"
2583 : $@
2584 )
2585 and next CMD;
2586
2587 # Load up dumpvar if we don't have it. If we can, that is.
2588 do 'dumpvar.pl' unless defined &main::dumpvar;
2589 defined &main::dumpvar
2590 or print $OUT "dumpvar.pl not available.\n"
2591 and next CMD;
2592
2593 # Got all the modules we need. Find them and print them.
e22ea7cc 2594 my @vars = split( ' ', $2 || '' );
69893cff
RGS
2595
2596 # Find the pad.
e22ea7cc 2597 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
69893cff
RGS
2598
2599 # Oops. Can't find it.
2600 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2601
2602 # Show the desired vars with dumplex().
2603 my $savout = select($OUT);
2604
2605 # Have dumplex dump the lexicals.
e22ea7cc 2606 dumpvar::dumplex( $_, $h->{$_},
69893cff 2607 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2608 @vars )
2609 for sort keys %$h;
69893cff
RGS
2610 select($savout);
2611 next CMD;
2612 };
2613
2614=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2615
2616All of the commands below this point don't work after the program being
2617debugged has ended. All of them check to see if the program has ended; this
2618allows the commands to be relocated without worrying about a 'line of
2619demarcation' above which commands can be entered anytime, and below which
2620they can't.
2621
2622=head4 C<n> - single step, but don't trace down into subs
2623
2624Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2625when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
69893cff
RGS
2626so a null command knows what to re-execute.
2627
2628=cut
2629
e22ea7cc 2630 # n - next
69893cff
RGS
2631 $cmd =~ /^n$/ && do {
2632 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2633
69893cff
RGS
2634 # Single step, but don't enter subs.
2635 $single = 2;
e22ea7cc 2636
69893cff 2637 # Save for empty command (repeat last).
e22ea7cc
RF
2638 $laststep = $cmd;
2639 last CMD;
2640 };
69893cff
RGS
2641
2642=head4 C<s> - single-step, entering subs
2643
be9a9b1d 2644Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2645subs. Also saves C<s> as C<$lastcmd>.
2646
2647=cut
2648
2649 # s - single step.
2650 $cmd =~ /^s$/ && do {
e22ea7cc 2651
69893cff
RGS
2652 # Get out and restart the command loop if program
2653 # has finished.
e22ea7cc
RF
2654 end_report(), next CMD if $finished and $level <= 1;
2655
69893cff 2656 # Single step should enter subs.
e22ea7cc
RF
2657 $single = 1;
2658
69893cff 2659 # Save for empty command (repeat last).
e22ea7cc
RF
2660 $laststep = $cmd;
2661 last CMD;
2662 };
69893cff
RGS
2663
2664=head4 C<c> - run continuously, setting an optional breakpoint
2665
2666Most of the code for this command is taken up with locating the optional
2667breakpoint, which is either a subroutine name or a line number. We set
2668the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2669in this and all call levels above this one.
2670
2671=cut
2672
2673 # c - start continuous execution.
2674 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
e22ea7cc 2675
69893cff
RGS
2676 # Hey, show's over. The debugged program finished
2677 # executing already.
2678 end_report(), next CMD if $finished and $level <= 1;
2679
2680 # Capture the place to put a one-time break.
2681 $subname = $i = $1;
2682
e22ea7cc
RF
2683 # Probably not needed, since we finish an interactive
2684 # sub-session anyway...
2685 # local $filename = $filename;
2686 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2687 #
2688 # The above question wonders if localizing the alias
2689 # to the magic array works or not. Since it's commented
2690 # out, we'll just leave that to speculation for now.
2691
2692 # If the "subname" isn't all digits, we'll assume it
2693 # is a subroutine name, and try to find it.
e22ea7cc
RF
2694 if ( $subname =~ /\D/ ) { # subroutine name
2695 # Qualify it to the current package unless it's
2696 # already qualified.
69893cff
RGS
2697 $subname = $package . "::" . $subname
2698 unless $subname =~ /::/;
e22ea7cc 2699
69893cff
RGS
2700 # find_sub will return "file:line_number" corresponding
2701 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2702 # break up the return value, and assign it in one
69893cff 2703 # operation.
e22ea7cc 2704 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2705
2706 # Force the line number to be numeric.
e22ea7cc 2707 $i += 0;
69893cff
RGS
2708
2709 # If we got a line number, we found the sub.
e22ea7cc
RF
2710 if ($i) {
2711
69893cff
RGS
2712 # Switch all the debugger's internals around so
2713 # we're actually working with that file.
e22ea7cc
RF
2714 $filename = $file;
2715 *dbline = $main::{ '_<' . $filename };
2716
69893cff 2717 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2718 $had_breakpoints{$filename} |= 1;
2719
69893cff
RGS
2720 # Scan forward to the first executable line
2721 # after the 'sub whatever' line.
e22ea7cc
RF
2722 $max = $#dbline;
2723 ++$i while $dbline[$i] == 0 && $i < $max;
2724 } ## end if ($i)
69893cff
RGS
2725
2726 # We didn't find a sub by that name.
e22ea7cc
RF
2727 else {
2728 print $OUT "Subroutine $subname not found.\n";
2729 next CMD;
2730 }
2731 } ## end if ($subname =~ /\D/)
69893cff
RGS
2732
2733 # At this point, either the subname was all digits (an
2734 # absolute line-break request) or we've scanned through
2735 # the code following the definition of the sub, looking
2736 # for an executable, which we may or may not have found.
2737 #
2738 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2739 # got a request to break at some line somewhere. On
2740 # one hand, if there wasn't any real subroutine name
2741 # involved, this will be a request to break in the current
2742 # file at the specified line, so we have to check to make
69893cff
RGS
2743 # sure that the line specified really is breakable.
2744 #
2745 # On the other hand, if there was a subname supplied, the
2746 # preceeding block has moved us to the proper file and
2747 # location within that file, and then scanned forward
2748 # looking for the next executable line. We have to make
2749 # sure that one was found.
2750 #
2751 # On the gripping hand, we can't do anything unless the
2752 # current value of $i points to a valid breakable line.
2753 # Check that.
e22ea7cc
RF
2754 if ($i) {
2755
69893cff 2756 # Breakable?
e22ea7cc
RF
2757 if ( $dbline[$i] == 0 ) {
2758 print $OUT "Line $i not breakable.\n";
2759 next CMD;
2760 }
2761
69893cff 2762 # Yes. Set up the one-time-break sigil.
e22ea7cc
RF
2763 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2764 } ## end if ($i)
69893cff
RGS
2765
2766 # Turn off stack tracing from here up.
e22ea7cc
RF
2767 for ( $i = 0 ; $i <= $stack_depth ; ) {
2768 $stack[ $i++ ] &= ~1;
2769 }
2770 last CMD;
2771 };
69893cff
RGS
2772
2773=head4 C<r> - return from a subroutine
2774
2775For C<r> to work properly, the debugger has to stop execution again
2776immediately after the return is executed. This is done by forcing
2777single-stepping to be on in the call level above the current one. If
2778we are printing return values when a C<r> is executed, set C<$doret>
2779appropriately, and force us out of the command loop.
2780
2781=cut
2782
2783 # r - return from the current subroutine.
e22ea7cc
RF
2784 $cmd =~ /^r$/ && do {
2785
69893cff 2786 # Can't do anythign if the program's over.
e22ea7cc
RF
2787 end_report(), next CMD if $finished and $level <= 1;
2788
69893cff 2789 # Turn on stack trace.
e22ea7cc
RF
2790 $stack[$stack_depth] |= 1;
2791
69893cff 2792 # Print return value unless the stack is empty.
e22ea7cc
RF
2793 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2794 last CMD;
2795 };
69893cff 2796
69893cff
RGS
2797=head4 C<T> - stack trace
2798
2799Just calls C<DB::print_trace>.
2800
2801=cut
2802
e22ea7cc
RF
2803 $cmd =~ /^T$/ && do {
2804 print_trace( $OUT, 1 ); # skip DB
2805 next CMD;
2806 };
69893cff
RGS
2807
2808=head4 C<w> - List window around current line.
2809
2810Just calls C<DB::cmd_w>.
2811
2812=cut
2813
e22ea7cc 2814 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
69893cff
RGS
2815
2816=head4 C<W> - watch-expression processing.
2817
2818Just calls C<DB::cmd_W>.
2819
2820=cut
2821
e22ea7cc 2822 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
69893cff
RGS
2823
2824=head4 C</> - search forward for a string in the source
2825
2826We take the argument and treat it as a pattern. If it turns out to be a
2827bad one, we return the error we got from trying to C<eval> it and exit.
2828If not, we create some code to do the search and C<eval> it so it can't
2829mess us up.
2830
2831=cut
2832
e22ea7cc 2833 $cmd =~ /^\/(.*)$/ && do {
69893cff
RGS
2834
2835 # The pattern as a string.
e22ea7cc 2836 $inpat = $1;
69893cff
RGS
2837
2838 # Remove the final slash.
e22ea7cc 2839 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2840
2841 # If the pattern isn't null ...
e22ea7cc 2842 if ( $inpat ne "" ) {
69893cff
RGS
2843
2844 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2845 local $SIG{__DIE__};
2846 local $SIG{__WARN__};
69893cff
RGS
2847
2848 # Create the pattern.
e22ea7cc
RF
2849 eval '$inpat =~ m' . "\a$inpat\a";
2850 if ( $@ ne "" ) {
2851
69893cff 2852 # Oops. Bad pattern. No biscuit.
e22ea7cc 2853 # Print the eval error and go back for more
69893cff 2854 # commands.
e22ea7cc
RF
2855 print $OUT "$@";
2856 next CMD;
2857 }
2858 $pat = $inpat;
2859 } ## end if ($inpat ne "")
69893cff
RGS
2860
2861 # Set up to stop on wrap-around.
e22ea7cc 2862 $end = $start;
69893cff
RGS
2863
2864 # Don't move off the current line.
e22ea7cc 2865 $incr = -1;
69893cff
RGS
2866
2867 # Done in eval so nothing breaks if the pattern
2868 # does something weird.
e22ea7cc
RF
2869 eval '
2870 for (;;) {
69893cff 2871 # Move ahead one line.
e22ea7cc 2872 ++$start;
69893cff
RGS
2873
2874 # Wrap if we pass the last line.
e22ea7cc 2875 $start = 1 if ($start > $max);
69893cff
RGS
2876
2877 # Stop if we have gotten back to this line again,
e22ea7cc 2878 last if ($start == $end);
69893cff
RGS
2879
2880 # A hit! (Note, though, that we are doing
2881 # case-insensitive matching. Maybe a qr//
2882 # expression would be better, so the user could
2883 # do case-sensitive matching if desired.
e22ea7cc
RF
2884 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2885 if ($slave_editor) {
69893cff 2886 # Handle proper escaping in the slave.
e22ea7cc
RF
2887 print $OUT "\032\032$filename:$start:0\n";
2888 }
2889 else {
69893cff 2890 # Just print the line normally.
e22ea7cc
RF
2891 print $OUT "$start:\t",$dbline[$start],"\n";
2892 }
69893cff 2893 # And quit since we found something.
e22ea7cc
RF
2894 last;
2895 }
2896 } ';
2897
69893cff 2898 # If we wrapped, there never was a match.
e22ea7cc
RF
2899 print $OUT "/$pat/: not found\n" if ( $start == $end );
2900 next CMD;
2901 };
69893cff
RGS
2902
2903=head4 C<?> - search backward for a string in the source
2904
2905Same as for C</>, except the loop runs backwards.
2906
2907=cut
2908
2909 # ? - backward pattern search.
e22ea7cc 2910 $cmd =~ /^\?(.*)$/ && do {
69893cff
RGS
2911
2912 # Get the pattern, remove trailing question mark.
e22ea7cc
RF
2913 $inpat = $1;
2914 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2915
2916 # If we've got one ...
e22ea7cc 2917 if ( $inpat ne "" ) {
69893cff
RGS
2918
2919 # Turn off die & warn handlers.
e22ea7cc
RF
2920 local $SIG{__DIE__};
2921 local $SIG{__WARN__};
2922 eval '$inpat =~ m' . "\a$inpat\a";
2923
2924 if ( $@ ne "" ) {
2925
69893cff 2926 # Ouch. Not good. Print the error.
e22ea7cc
RF
2927 print $OUT $@;
2928 next CMD;
2929 }
2930 $pat = $inpat;
69893cff 2931 } ## end if ($inpat ne "")
e22ea7cc 2932
69893cff 2933 # Where we are now is where to stop after wraparound.
e22ea7cc 2934 $end = $start;
69893cff
RGS
2935
2936 # Don't move away from this line.
e22ea7cc 2937 $incr = -1;
69893cff
RGS
2938
2939 # Search inside the eval to prevent pattern badness
2940 # from killing us.
e22ea7cc
RF
2941 eval '
2942 for (;;) {
69893cff 2943 # Back up a line.
e22ea7cc 2944 --$start;
69893cff
RGS
2945
2946 # Wrap if we pass the first line.
e22ea7cc
RF
2947
2948 $start = $max if ($start <= 0);
69893cff
RGS
2949
2950 # Quit if we get back where we started,
e22ea7cc 2951 last if ($start == $end);
69893cff
RGS
2952
2953 # Match?
e22ea7cc
RF
2954 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2955 if ($slave_editor) {
69893cff 2956 # Yep, follow slave editor requirements.
e22ea7cc
RF
2957 print $OUT "\032\032$filename:$start:0\n";
2958 }
2959 else {
69893cff 2960 # Yep, just print normally.
e22ea7cc
RF
2961 print $OUT "$start:\t",$dbline[$start],"\n";
2962 }
69893cff
RGS
2963
2964 # Found, so done.
e22ea7cc
RF
2965 last;
2966 }
2967 } ';
2968
2969 # Say we failed if the loop never found anything,
2970 print $OUT "?$pat?: not found\n" if ( $start == $end );
2971 next CMD;
2972 };
69893cff
RGS
2973
2974=head4 C<$rc> - Recall command
2975
2976Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2977that the terminal supports history). It find the the command required, puts it
2978into C<$cmd>, and redoes the loop to execute it.
2979
2980=cut
2981
e22ea7cc
RF
2982 # $rc - recall command.
2983 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
69893cff
RGS
2984
2985 # No arguments, take one thing off history.
e22ea7cc 2986 pop(@hist) if length($cmd) > 1;
69893cff 2987
e22ea7cc 2988 # Relative (- found)?
69893cff 2989 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2990 # N - go to that particular command slot or the last
69893cff 2991 # thing if nothing following.
e22ea7cc 2992 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
69893cff
RGS
2993
2994 # Pick out the command desired.
e22ea7cc 2995 $cmd = $hist[$i];
69893cff
RGS
2996
2997 # Print the command to be executed and restart the loop
2998 # with that command in the buffer.
e22ea7cc
RF
2999 print $OUT $cmd, "\n";
3000 redo CMD;
3001 };
69893cff
RGS
3002
3003=head4 C<$sh$sh> - C<system()> command
3004
3005Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3006C<STDOUT> from getting messed up.
3007
3008=cut
3009
3010 # $sh$sh - run a shell command (if it's all ASCII).
3011 # Can't run shell commands with Unicode in the debugger, hmm.
e22ea7cc
RF
3012 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3013
69893cff 3014 # System it.
e22ea7cc
RF
3015 &system($1);
3016 next CMD;
3017 };
69893cff
RGS
3018
3019=head4 C<$rc I<pattern> $rc> - Search command history
3020
3021Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3022If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3023
3024=cut
3025
e22ea7cc
RF
3026 # $rc pattern $rc - find a command in the history.
3027 $cmd =~ /^$rc([^$rc].*)$/ && do {
3028
69893cff 3029 # Create the pattern to use.
e22ea7cc 3030 $pat = "^$1";
69893cff
RGS
3031
3032 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 3033 pop(@hist) if length($cmd) > 1;
69893cff
RGS
3034
3035 # Look backward through the history.
e22ea7cc
RF
3036 for ( $i = $#hist ; $i ; --$i ) {
3037
69893cff 3038 # Stop if we find it.
e22ea7cc
RF
3039 last if $hist[$i] =~ /$pat/;
3040 }
3041
3042 if ( !$i ) {
69893cff 3043
69893cff 3044 # Never found it.
e22ea7cc
RF
3045 print $OUT "No such command!\n\n";
3046 next CMD;
3047 }
69893cff
RGS
3048
3049 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
3050 $cmd = $hist[$i];
3051 print $OUT $cmd, "\n";
3052 redo CMD;
3053 };
69893cff
RGS
3054
3055=head4 C<$sh> - Invoke a shell
3056
3057Uses C<DB::system> to invoke a shell.
3058
3059=cut
3060
3061 # $sh - start a shell.
e22ea7cc
RF
3062 $cmd =~ /^$sh$/ && do {
3063
69893cff
RGS
3064 # Run the user's shell. If none defined, run Bourne.
3065 # We resume execution when the shell terminates.
e22ea7cc
RF
3066 &system( $ENV{SHELL} || "/bin/sh" );
3067 next CMD;
3068 };
69893cff
RGS
3069
3070=head4 C<$sh I<command>> - Force execution of a command in a shell
3071
3072Like the above, but the command is passed to the shell. Again, we use
3073C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3074
3075=cut
3076
3077 # $sh command - start a shell and run a command in it.
e22ea7cc
RF
3078 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3079
3080 # XXX: using csh or tcsh destroys sigint retvals!
3081 #&system($1); # use this instead
69893cff
RGS
3082
3083 # use the user's shell, or Bourne if none defined.
e22ea7cc
RF
3084 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3085 next CMD;
3086 };
69893cff
RGS
3087
3088=head4 C<H> - display commands in history
3089
3090Prints the contents of C<@hist> (if any).
3091
3092=cut
3093
7fddc82f
RF
3094 $cmd =~ /^H\b\s*\*/ && do {
3095 @hist = @truehist = ();
3096 print $OUT "History cleansed\n";
3097 next CMD;
3098 };
e22ea7cc
RF
3099
3100 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3101
3102 # Anything other than negative numbers is ignored by
69893cff 3103 # the (incorrect) pattern, so this test does nothing.
e22ea7cc 3104 $end = $2 ? ( $#hist - $2 ) : 0;
69893cff
RGS
3105
3106 # Set to the minimum if less than zero.
e22ea7cc 3107 $hist = 0 if $hist < 0;
69893cff 3108
e22ea7cc 3109 # Start at the end of the array.
69893cff
RGS
3110 # Stay in while we're still above the ending value.
3111 # Tick back by one each time around the loop.
e22ea7cc 3112 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3113
3114 # Print the command unless it has no arguments.
e22ea7cc
RF
3115 print $OUT "$i: ", $hist[$i], "\n"
3116 unless $hist[$i] =~ /^.?$/;
3117 }
3118 next CMD;
3119 };
69893cff
RGS
3120
3121=head4 C<man, doc, perldoc> - look up documentation
3122
3123Just calls C<runman()> to print the appropriate document.
3124
3125=cut
3126
e22ea7cc
RF
3127 # man, perldoc, doc - show manual pages.
3128 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3129 runman($1);
3130 next CMD;
3131 };
69893cff
RGS
3132
3133=head4 C<p> - print
3134
3135Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3136the bottom of the loop.
3137
3138=cut
3139
3140 # p - print (no args): print $_.
e22ea7cc 3141 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
69893cff
RGS
3142
3143 # p - print the given expression.
e22ea7cc 3144 $cmd =~ s/^p\b/print {\$DB::OUT} /;
69893cff
RGS
3145
3146=head4 C<=> - define command alias
3147
3148Manipulates C<%alias> to add or list command aliases.
3149
3150=cut
3151
e22ea7cc
RF
3152 # = - set up a command alias.
3153 $cmd =~ s/^=\s*// && do {
3154 my @keys;
3155 if ( length $cmd == 0 ) {
3156
69893cff 3157 # No args, get current aliases.
e22ea7cc
RF
3158 @keys = sort keys %alias;
3159 }
3160 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3161
69893cff
RGS
3162 # Creating a new alias. $k is alias name, $v is
3163 # alias value.
3164
e22ea7cc
RF
3165 # can't use $_ or kill //g state
3166 for my $x ( $k, $v ) {
3167
3168 # Escape "alarm" characters.
3169 $x =~ s/\a/\\a/g;
3170 }
69893cff
RGS
3171
3172 # Substitute key for value, using alarm chars
e22ea7cc 3173 # as separators (which is why we escaped them in
69893cff 3174 # the command).
e22ea7cc 3175 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3176
3177 # Turn off standard warn and die behavior.
e22ea7cc
RF
3178 local $SIG{__DIE__};
3179 local $SIG{__WARN__};
69893cff
RGS
3180
3181 # Is it valid Perl?
e22ea7cc
RF
3182 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3183
69893cff 3184 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3185 print $OUT "Can't alias $k to $v: $@\n";
3186 delete $alias{$k};
3187 next CMD;
3188 }
3189
69893cff 3190 # We'll only list the new one.
e22ea7cc 3191 @keys = ($k);
69893cff
RGS
3192 } ## end elsif (my ($k, $v) = ($cmd...
3193
3194 # The argument is the alias to list.
e22ea7cc
RF
3195 else {
3196 @keys = ($cmd);
3197 }
69893cff
RGS
3198
3199 # List aliases.
e22ea7cc
RF
3200 for my $k (@keys) {
3201
69893cff
RGS
3202 # Messy metaquoting: Trim the substiution code off.
3203 # We use control-G as the delimiter because it's not
3204 # likely to appear in the alias.
e22ea7cc
RF
3205 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3206
69893cff 3207 # Print the alias.
e22ea7cc
RF
3208 print $OUT "$k\t= $1\n";
3209 }
3210 elsif ( defined $alias{$k} ) {
3211
69893cff 3212 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3213 print $OUT "$k\t$alias{$k}\n";
3214 }
3215 else {
3216
69893cff 3217 # No such, dude.
e22ea7cc
RF
3218 print "No alias for $k\n";
3219 }
69893cff 3220 } ## end for my $k (@keys)
e22ea7cc
RF
3221 next CMD;
3222 };
69893cff
RGS
3223
3224=head4 C<source> - read commands from a file.
3225
3226Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3227pick it up.
3228
3229=cut
3230
e22ea7cc
RF
3231 # source - read commands from a file (or pipe!) and execute.
3232 $cmd =~ /^source\s+(.*\S)/ && do {
3233 if ( open my $fh, $1 ) {
3234
69893cff 3235 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3236 push @cmdfhs, $fh;
3237 }
3238 else {
3239
3240 # Couldn't open it.
3241 &warn("Can't execute `$1': $!\n");
3242 }
3243 next CMD;
3244 };
69893cff
RGS
3245
3246=head4 C<save> - send current history to a file
3247
3248Takes the complete history, (not the shrunken version you see with C<H>),
3249and saves it to the given filename, so it can be replayed using C<source>.
3250
3251Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3252
3253=cut
3254
3255 # save source - write commands to a file for later use
3256 $cmd =~ /^save\s*(.*)$/ && do {
e22ea7cc
RF
3257 my $file = $1 || '.perl5dbrc'; # default?
3258 if ( open my $fh, "> $file" ) {
3259
3260 # chomp to remove extraneous newlines from source'd files
3261 chomp( my @truelist =
3262 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3263 @truehist );
3264 print $fh join( "\n", @truelist );
69893cff 3265 print "commands saved in $file\n";
e22ea7cc
RF
3266 }
3267 else {
69893cff
RGS
3268 &warn("Can't save debugger commands in '$1': $!\n");
3269 }
3270 next CMD;
3271 };
3272
7fddc82f
RF
3273=head4 C<R> - restart
3274
3275Restart the debugger session.
3276
3277=head4 C<rerun> - rerun the current session
3278
3279Return to any given position in the B<true>-history list
3280
3281=cut
3282
3283 # R - restart execution.
3284 # rerun - controlled restart execution.
3285 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3286 my @args = ($1 eq 'R' ? restart() : rerun($2));
3287
ca28b541
AP
3288 # Close all non-system fds for a clean restart. A more
3289 # correct method would be to close all fds that were not
3290 # open when the process started, but this seems to be
3291 # hard. See "debugger 'R'estart and open database
3292 # connections" on p5p.
3293
47d3bbda 3294 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541
AP
3295 if (eval { require POSIX }) {
3296 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3297 }
3298
3299 if (defined $max_fd) {
3300 foreach ($^F+1 .. $max_fd-1) {
3301 next unless open FD_TO_CLOSE, "<&=$_";
3302 close(FD_TO_CLOSE);
3303 }
3304 }
3305
7fddc82f
RF
3306 # And run Perl again. We use exec() to keep the
3307 # PID stable (and that way $ini_pids is still valid).
3308 exec(@args) || print $OUT "exec failed: $!\n";
3309
3310 last CMD;
3311 };
3312
69893cff
RGS
3313=head4 C<|, ||> - pipe output through the pager.
3314
be9a9b1d 3315For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3316(the program's standard output). For C<||>, we only save C<OUT>. We open a
3317pipe to the pager (restoring the output filehandles if this fails). If this
3318is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3319set C<$signal>, sending us back into the debugger.
3320
3321We then trim off the pipe symbols and C<redo> the command loop at the
3322C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3323reading another.
3324
3325=cut
3326
3327 # || - run command in the pager, with output to DB::OUT.
e22ea7cc
RF
3328 $cmd =~ /^\|\|?\s*[^|]/ && do {
3329 if ( $pager =~ /^\|/ ) {
3330
69893cff 3331 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3332 open( SAVEOUT, ">&STDOUT" )
3333 || &warn("Can't save STDOUT");
3334 open( STDOUT, ">&OUT" )
3335 || &warn("Can't redirect STDOUT");
69893cff 3336 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3337 else {
3338
69893cff 3339 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3340 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3341 }
69893cff
RGS
3342
3343 # Fix up environment to record we have less if so.
e22ea7cc
RF
3344 fix_less();
3345
3346 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3347
69893cff 3348 # Couldn't open pipe to pager.
e22ea7cc
RF
3349 &warn("Can't pipe output to `$pager'");
3350 if ( $pager =~ /^\|/ ) {
3351
69893cff 3352 # Redirect I/O back again.
e22ea7cc
RF
3353 open( OUT, ">&STDOUT" ) # XXX: lost message
3354 || &warn("Can't restore DB::OUT");
3355 open( STDOUT, ">&SAVEOUT" )
3356 || &warn("Can't restore STDOUT");
3357 close(SAVEOUT);
69893cff 3358 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3359 else {
3360
69893cff 3361 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3362 open( OUT, ">&STDOUT" ) # XXX: lost message
3363 || &warn("Can't restore DB::OUT");
3364 }
3365 next CMD;
69893cff
RGS
3366 } ## end unless ($piped = open(OUT,...
3367
3368 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3369 $SIG{PIPE} = \&DB::catch
3370 if $pager =~ /^\|/
3371 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff
RGS
3372
3373 # Save current filehandle, unbuffer out, and put it back.
e22ea7cc
RF
3374 $selected = select(OUT);
3375 $| = 1;
69893cff
RGS
3376
3377 # Don't put it back if pager was a pipe.
e22ea7cc 3378 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3379
3380 # Trim off the pipe symbols and run the command now.
e22ea7cc
RF
3381 $cmd =~ s/^\|+\s*//;
3382 redo PIPE;
3383 };
69893cff
RGS
3384
3385=head3 END OF COMMAND PARSING
3386
3387Anything left in C<$cmd> at this point is a Perl expression that we want to
3388evaluate. We'll always evaluate in the user's context, and fully qualify
3389any variables we might want to address in the C<DB> package.
3390
3391=cut
3392
3393 # t - turn trace on.
e22ea7cc 3394 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
69893cff
RGS
3395
3396 # s - single-step. Remember the last command was 's'.
e22ea7cc 3397 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
69893cff
RGS
3398
3399 # n - single-step, but not into subs. Remember last command
e22ea7cc
RF
3400 # was 'n'.
3401 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
69893cff 3402
e22ea7cc 3403 } # PIPE:
69893cff 3404
e22ea7cc 3405 # Make sure the flag that says "the debugger's running" is
69893cff 3406 # still on, to make sure we get control again.
e22ea7cc 3407 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3408
3409 # Run *our* eval that executes in the caller's context.
e22ea7cc 3410 &eval;
69893cff
RGS
3411
3412 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3413 if ($onetimeDump) {
3414 $onetimeDump = undef;
69893cff 3415 $onetimedumpDepth = undef;
e22ea7cc
RF
3416 }
3417 elsif ( $term_pid == $$ ) {
3418 STDOUT->flush();
3419 STDERR->flush();
3420
69893cff 3421 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3422 print $OUT "\n";
3423 }
3424 } ## end while (($term || &setterm...
69893cff
RGS
3425
3426=head3 POST-COMMAND PROCESSING
3427
3428After each command, we check to see if the command output was piped anywhere.
3429If so, we go through the necessary code to unhook the pipe and go back to
3430our standard filehandles for input and output.
3431
3432=cut
3433
e22ea7cc 3434 continue { # CMD:
69893cff
RGS
3435
3436 # At the end of every command:
e22ea7cc
RF
3437 if ($piped) {
3438
69893cff 3439 # Unhook the pipe mechanism now.
e22ea7cc
RF
3440 if ( $pager =~ /^\|/ ) {
3441
69893cff 3442 # No error from the child.
e22ea7cc 3443 $? = 0;
69893cff 3444
e22ea7cc
RF
3445 # we cannot warn here: the handle is missing --tchrist
3446 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3447
e22ea7cc 3448 # most of the $? crud was coping with broken cshisms
69893cff 3449 # $? is explicitly set to 0, so this never runs.
e22ea7cc
RF
3450 if ($?) {
3451 print SAVEOUT "Pager `$pager' failed: ";
3452 if ( $? == -1 ) {
3453 print SAVEOUT "shell returned -1\n";
3454 }
3455 elsif ( $? >> 8 ) {
3456 print SAVEOUT ( $? & 127 )
3457 ? " (SIG#" . ( $? & 127 ) . ")"
3458 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3459 }
3460 else {
3461 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3462 }
69893cff
RGS
3463 } ## end if ($?)
3464
e22ea7cc 3465 # Reopen filehandle for our output (if we can) and
69893cff 3466 # restore STDOUT (if we can).
e22ea7cc
RF
3467 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3468 open( STDOUT, ">&SAVEOUT" )
3469 || &warn("Can't restore STDOUT");
69893cff
RGS
3470
3471 # Turn off pipe exception handler if necessary.
e22ea7cc 3472 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3473
e22ea7cc
RF
3474 # Will stop ignoring SIGPIPE if done like nohup(1)
3475 # does SIGINT but Perl doesn't give us a choice.
69893cff 3476 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3477 else {
3478
69893cff 3479 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3480 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3481 }
69893cff
RGS
3482
3483 # Close filehandle pager was using, restore the normal one
3484 # if necessary,
3485 close(SAVEOUT);
e22ea7cc 3486 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3487
3488 # No pipes now.
e22ea7cc 3489 $piped = "";
69893cff 3490 } ## end if ($piped)
e22ea7cc 3491 } # CMD:
69893cff
RGS
3492
3493=head3 COMMAND LOOP TERMINATION
3494
3495When commands have finished executing, we come here. If the user closed the
3496input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3497evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3498C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3499The interpreter will then execute the next line and then return control to us
3500again.
3501
3502=cut
3503
3504 # No more commands? Quit.
e22ea7cc 3505 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
69893cff
RGS
3506
3507 # Evaluate post-prompt commands.
e22ea7cc
RF
3508 foreach $evalarg (@$post) {
3509 &eval;
3510 }
3511 } # if ($single || $signal)
69893cff
RGS
3512
3513 # Put the user's globals back where you found them.
e22ea7cc 3514 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3515 ();
3516} ## end sub DB
3517
3518# The following code may be executed now:
3519# BEGIN {warn 4}
3520
3521=head2 sub
3522
3523C<sub> is called whenever a subroutine call happens in the program being
3524debugged. The variable C<$DB::sub> contains the name of the subroutine
3525being called.
3526
3527The core function of this subroutine is to actually call the sub in the proper
3528context, capturing its output. This of course causes C<DB::DB> to get called
3529again, repeating until the subroutine ends and returns control to C<DB::sub>
3530again. Once control returns, C<DB::sub> figures out whether or not to dump the
3531return value, and returns its captured copy of the return value as its own
3532return value. The value then feeds back into the program being debugged as if
3533C<DB::sub> hadn't been there at all.
3534
3535C<sub> does all the work of printing the subroutine entry and exit messages
3536enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3537and also prints the return value if needed (for the C<r> command and if
3538the 16 bit is set in C<$frame>).
3539
3540It also tracks the subroutine call depth by saving the current setting of
3541C<$single> in the C<@stack> package global; if this exceeds the value in
3542C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3543setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3544of stop/don't stop on entry to subs set as it currently is set.
3545
3546=head3 C<caller()> support
3547
3548If C<caller()> is called from the package C<DB>, it provides some
3549additional data, in the following order:
3550
3551=over 4
3552
3553=item * C<$package>
3554
3555The package name the sub was in
3556
3557=item * C<$filename>
3558
3559The filename it was defined in
3560
3561=item * C<$line>
3562
3563The line number it was defined on
3564
3565=item * C<$subroutine>
3566
be9a9b1d 3567The subroutine name; C<(eval)> if an C<eval>().
69893cff
RGS
3568
3569=item * C<$hasargs>
3570
35711 if it has arguments, 0 if not
3572
3573=item * C<$wantarray>
3574
35751 if array context, 0 if scalar context
3576
3577=item * C<$evaltext>
3578
3579The C<eval>() text, if any (undefined for C<eval BLOCK>)
3580
3581=item * C<$is_require>
3582
3583frame was created by a C<use> or C<require> statement
3584
3585=item * C<$hints>
3586
3587pragma information; subject to change between versions
3588
3589=item * C<$bitmask>
3590
be9a9b1d 3591pragma information; subject to change between versions
69893cff
RGS
3592
3593=item * C<@DB::args>
3594
3595arguments with which the subroutine was invoked
3596
3597=back
3598
3599=cut
d338d6fe 3600
d12a4851 3601sub sub {
69893cff 3602
2cbb2ee1
RGS
3603 # lock ourselves under threads
3604 lock($DBGR);
3605
69893cff
RGS
3606 # Whether or not the autoloader was running, a scalar to put the
3607 # sub's return value in (if needed), and an array to put the sub's
3608 # return value in (if needed).
e22ea7cc 3609 my ( $al, $ret, @ret ) = "";
2cbb2ee1
RGS
3610 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3611 print "creating new thread\n";
3612 }
69893cff
RGS
3613
3614 # If the last ten characters are C'::AUTOLOAD', note we've traced
3615 # into AUTOLOAD for $sub.
e22ea7cc
RF
3616 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3617 $al = " for $$sub";
d12a4851 3618 }
69893cff
RGS
3619
3620 # We stack the stack pointer and then increment it to protect us
3621 # from a situation that might unwind a whole bunch of call frames
3622 # at once. Localizing the stack pointer means that it will automatically
3623 # unwind the same amount when multiple stack frames are unwound.
e22ea7cc 3624 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
69893cff
RGS
3625
3626 # Expand @stack.
d12a4851 3627 $#stack = $stack_depth;
69893cff
RGS
3628
3629 # Save current single-step setting.
d12a4851 3630 $stack[-1] = $single;
69893cff 3631
e22ea7cc 3632 # Turn off all flags except single-stepping.
d12a4851 3633 $single &= 1;
69893cff
RGS
3634
3635 # If we've gotten really deeply recursed, turn on the flag that will
3636 # make us stop with the 'deep recursion' message.
d12a4851 3637 $single |= 4 if $stack_depth == $deep;
69893cff
RGS
3638
3639 # If frame messages are on ...
3640 (
3641 $frame & 4 # Extended frame entry message
e22ea7cc
RF
3642 ? (
3643 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
69893cff 3644
e22ea7cc 3645 # Why -1? But it works! :-(
69893cff
RGS
3646 # Because print_trace will call add 1 to it and then call
3647 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3648 # in dump_trace.
e22ea7cc
RF
3649 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3650 )
3651 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3652
69893cff 3653 # standard frame entry message
e22ea7cc
RF
3654 )
3655 if $frame;
69893cff
RGS
3656
3657 # Determine the sub's return type,and capture approppriately.
d12a4851 3658 if (wantarray) {
e22ea7cc 3659
69893cff
RGS
3660 # Called in array context. call sub and capture output.
3661 # DB::DB will recursively get control again if appropriate; we'll come
3662 # back here when the sub is finished.
d12a4851 3663 if ($assertion) {
e22ea7cc
RF
3664 $assertion = 0;
3665 eval { @ret = &$sub; };
3666 if ($@) {
3667 print $OUT $@;
3668 $signal = 1 unless $warnassertions;
3669 }
3670 }
3671 else {
69893cff 3672 @ret = &$sub;
69893cff 3673 }
69893cff
RGS
3674
3675 # Pop the single-step value back off the stack.
e22ea7cc 3676 $single |= $stack[ $stack_depth-- ];
69893cff
RGS
3677
3678 # Check for exit trace messages...
e22ea7cc
RF
3679 (
3680 $frame & 4 # Extended exit message
3681 ? (
3682 print_lineinfo( ' ' x $stack_depth, "out " ),
3683 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3684 )
3685 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3686
69893cff 3687 # Standard exit message
e22ea7cc
RF
3688 )
3689 if $frame & 2;
69893cff
RGS
3690
3691 # Print the return info if we need to.
e22ea7cc
RF
3692 if ( $doret eq $stack_depth or $frame & 16 ) {
3693
69893cff 3694 # Turn off output record separator.
e22ea7cc
RF
3695 local $\ = '';
3696 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO );
69893cff
RGS
3697
3698 # Indent if we're printing because of $frame tracing.
e22ea7cc 3699 print $fh ' ' x $stack_depth if $frame & 16;
69893cff
RGS
3700
3701 # Print the return value.
e22ea7cc
RF
3702 print $fh "list context return from $sub:\n";
3703 dumpit( $fh, \@ret );
69893cff
RGS
3704
3705 # And don't print it again.
e22ea7cc 3706 $doret = -2;
69893cff 3707 } ## end if ($doret eq $stack_depth...
e22ea7cc
RF
3708 # And we have to return the return value now.
3709 @ret;<