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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
c7e68384 501BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 502
54d04a52 503# Debugger for Perl 5.00x; perl5db.pl patch level:
6fae1ad7 504$VERSION = 1.29;
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 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
SB
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.
3c4b39be 914# + Added command to display parent inheritance tree of given class.
e219e2fb 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)
6fae1ad7
RF
930# Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com>
931# + Added macosx_get_fork_TTY support
932########################################################################
d338d6fe 933
69893cff
RGS
934=head1 DEBUGGER INITIALIZATION
935
936The debugger starts up in phases.
937
938=head2 BASIC SETUP
939
940First, it initializes the environment it wants to run in: turning off
941warnings during its own compilation, defining variables which it will need
942to avoid warnings later, setting itself up to not exit when the program
943terminates, and defaulting to printing return values for the C<r> command.
944
945=cut
946
eda6e075 947# Needed for the statement after exec():
69893cff
RGS
948#
949# This BEGIN block is simply used to switch off warnings during debugger
950# compiliation. Probably it would be better practice to fix the warnings,
951# but this is how it's done at the moment.
eda6e075 952
e22ea7cc
RF
953BEGIN {
954 $ini_warn = $^W;
955 $^W = 0;
956} # Switch compilation warnings off until another BEGIN.
d12a4851
JH
957
958# test if assertions are supported and actived:
eda6e075 959BEGIN {
e22ea7cc
RF
960 $ini_assertion = eval "sub asserting_test : assertion {1}; 1";
961
d12a4851 962 # $ini_assertion = undef => assertions unsupported,
e22ea7cc 963 # " = 1 => assertions supported
d12a4851
JH
964 # print "\$ini_assertion=$ini_assertion\n";
965}
966
69893cff
RGS
967local ($^W) = 0; # Switch run-time warnings off during init.
968
2cbb2ee1
RGS
969=head2 THREADS SUPPORT
970
971If we are running under a threaded Perl, we require threads and threads::shared
972if the environment variable C<PERL5DB_THREADED> is set, to enable proper
973threaded debugger control. C<-dt> can also be used to set this.
974
975Each new thread will be announced and the debugger prompt will always inform
976you of each new thread created. It will also indicate the thread id in which
977we are currently running within the prompt like this:
978
979 [tid] DB<$i>
980
981Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
982command prompt. The prompt will show: C<[0]> when running under threads, but
983not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
984
985While running under threads, when you set or delete a breakpoint (etc.), this
986will apply to all threads, not just the currently running one. When you are
987in a currently executing thread, you will stay there until it completes. With
988the current implementation it is not currently possible to hop from one thread
989to another.
990
991The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
992
993Note that threading support was built into the debugger as of Perl version
994C<5.8.6> and debugger version C<1.2.8>.
995
996=cut
997
998BEGIN {
999 # ensure we can share our non-threaded variables or no-op
1000 if ($ENV{PERL5DB_THREADED}) {
1001 require threads;
1002 require threads::shared;
1003 import threads::shared qw(share);
1004 $DBGR;
1005 share(\$DBGR);
1006 lock($DBGR);
1007 print "Threads support enabled\n";
1008 } else {
1009 *lock = sub(*) {};
1010 *share = sub(*) {};
1011 }
1012}
1013
69893cff
RGS
1014# This would probably be better done with "use vars", but that wasn't around
1015# when this code was originally written. (Neither was "use strict".) And on
1016# the principle of not fiddling with something that was working, this was
1017# left alone.
1018warn( # Do not ;-)
2cbb2ee1 1019 # These variables control the execution of 'dumpvar.pl'.
69893cff
RGS
1020 $dumpvar::hashDepth,
1021 $dumpvar::arrayDepth,
1022 $dumpvar::dumpDBFiles,
1023 $dumpvar::dumpPackages,
1024 $dumpvar::quoteHighBit,
1025 $dumpvar::printUndef,
1026 $dumpvar::globPrint,
1027 $dumpvar::usageOnly,
1028
1029 # used to save @ARGV and extract any debugger-related flags.
1030 @ARGS,
1031
1032 # used to control die() reporting in diesignal()
1033 $Carp::CarpLevel,
1034
1035 # used to prevent multiple entries to diesignal()
1036 # (if for instance diesignal() itself dies)
1037 $panic,
1038
1039 # used to prevent the debugger from running nonstop
1040 # after a restart
1041 $second_time,
1042 )
1043 if 0;
d338d6fe 1044
2cbb2ee1
RGS
1045foreach my $k (keys (%INC)) {
1046 &share(\$main::{'_<'.$filename});
1047};
1048
54d04a52 1049# Command-line + PERLLIB:
69893cff 1050# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
1051@ini_INC = @INC;
1052
69893cff
RGS
1053# This was an attempt to clear out the previous values of various
1054# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe 1055# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
1056
69893cff
RGS
1057# We set these variables to safe values. We don't want to blindly turn
1058# off warnings, because other packages may still want them.
e22ea7cc
RF
1059$trace = $signal = $single = 0; # Uninitialized warning suppression
1060 # (local $^W cannot help - other packages!).
69893cff
RGS
1061
1062# Default to not exiting when program finishes; print the return
1063# value when the 'r' command is used to return from a subroutine.
55497cff 1064$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 1065
69893cff
RGS
1066=head1 OPTION PROCESSING
1067
1068The debugger's options are actually spread out over the debugger itself and
1069C<dumpvar.pl>; some of these are variables to be set, while others are
1070subs to be called with a value. To try to make this a little easier to
1071manage, the debugger uses a few data structures to define what options
1072are legal and how they are to be processed.
1073
1074First, the C<@options> array defines the I<names> of all the options that
1075are to be accepted.
1076
1077=cut
1078
1079@options = qw(
e22ea7cc
RF
1080 CommandSet
1081 hashDepth arrayDepth dumpDepth
1082 DumpDBFiles DumpPackages DumpReused
1083 compactDump veryCompact quote
1084 HighBit undefPrint globPrint
1085 PrintRet UsageOnly frame
1086 AutoTrace TTY noTTY
1087 ReadLine NonStop LineInfo
1088 maxTraceLen recallCommand ShellBang
1089 pager tkRunning ornaments
1090 signalLevel warnLevel dieLevel
1091 inhibit_exit ImmediateStop bareStringify
1092 CreateTTY RemotePort windowSize
1093 DollarCaretP OnlyAssertions WarnAssertions
1094);
d12a4851
JH
1095
1096@RememberOnROptions = qw(DollarCaretP OnlyAssertions);
1097
69893cff
RGS
1098=pod
1099
1100Second, C<optionVars> lists the variables that each option uses to save its
1101state.
1102
1103=cut
1104
1105%optionVars = (
e22ea7cc
RF
1106 hashDepth => \$dumpvar::hashDepth,
1107 arrayDepth => \$dumpvar::arrayDepth,
1108 CommandSet => \$CommandSet,
1109 DumpDBFiles => \$dumpvar::dumpDBFiles,
1110 DumpPackages => \$dumpvar::dumpPackages,
1111 DumpReused => \$dumpvar::dumpReused,
1112 HighBit => \$dumpvar::quoteHighBit,
1113 undefPrint => \$dumpvar::printUndef,
1114 globPrint => \$dumpvar::globPrint,
1115 UsageOnly => \$dumpvar::usageOnly,
1116 CreateTTY => \$CreateTTY,
1117 bareStringify => \$dumpvar::bareStringify,
1118 frame => \$frame,
1119 AutoTrace => \$trace,
1120 inhibit_exit => \$inhibit_exit,
1121 maxTraceLen => \$maxtrace,
1122 ImmediateStop => \$ImmediateStop,
1123 RemotePort => \$remoteport,
1124 windowSize => \$window,
1125 WarnAssertions => \$warnassertions,
69893cff
RGS
1126);
1127
1128=pod
1129
1130Third, C<%optionAction> defines the subroutine to be called to process each
1131option.
1132
1133=cut
1134
1135%optionAction = (
1136 compactDump => \&dumpvar::compactDump,
1137 veryCompact => \&dumpvar::veryCompact,
1138 quote => \&dumpvar::quote,
1139 TTY => \&TTY,
1140 noTTY => \&noTTY,
1141 ReadLine => \&ReadLine,
1142 NonStop => \&NonStop,
1143 LineInfo => \&LineInfo,
1144 recallCommand => \&recallCommand,
1145 ShellBang => \&shellBang,
1146 pager => \&pager,
1147 signalLevel => \&signalLevel,
1148 warnLevel => \&warnLevel,
1149 dieLevel => \&dieLevel,
1150 tkRunning => \&tkRunning,
1151 ornaments => \&ornaments,
1152 RemotePort => \&RemotePort,
1153 DollarCaretP => \&DollarCaretP,
1154 OnlyAssertions=> \&OnlyAssertions,
d12a4851
JH
1155);
1156
69893cff
RGS
1157=pod
1158
1159Last, the C<%optionRequire> notes modules that must be C<require>d if an
1160option is used.
1161
1162=cut
d338d6fe 1163
69893cff
RGS
1164# Note that this list is not complete: several options not listed here
1165# actually require that dumpvar.pl be loaded for them to work, but are
1166# not in the table. A subsequent patch will correct this problem; for
1167# the moment, we're just recommenting, and we are NOT going to change
1168# function.
eda6e075 1169%optionRequire = (
69893cff
RGS
1170 compactDump => 'dumpvar.pl',
1171 veryCompact => 'dumpvar.pl',
1172 quote => 'dumpvar.pl',
e22ea7cc 1173);
69893cff
RGS
1174
1175=pod
1176
1177There are a number of initialization-related variables which can be set
1178by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1179variable. These are:
1180
1181=over 4
1182
1183=item C<$rl> - readline control XXX needs more explanation
1184
1185=item C<$warnLevel> - whether or not debugger takes over warning handling
1186
1187=item C<$dieLevel> - whether or not debugger takes over die handling
1188
1189=item C<$signalLevel> - whether or not debugger takes over signal handling
1190
1191=item C<$pre> - preprompt actions (array reference)
1192
1193=item C<$post> - postprompt actions (array reference)
1194
1195=item C<$pretype>
1196
1197=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1198
1199=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1200
1201=back
1202
1203=cut
d338d6fe 1204
1205# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1206$rl = 1 unless defined $rl;
1207$warnLevel = 1 unless defined $warnLevel;
1208$dieLevel = 1 unless defined $dieLevel;
1209$signalLevel = 1 unless defined $signalLevel;
1210$pre = [] unless defined $pre;
1211$post = [] unless defined $post;
1212$pretype = [] unless defined $pretype;
1213$CreateTTY = 3 unless defined $CreateTTY;
1214$CommandSet = '580' unless defined $CommandSet;
1215
2cbb2ee1
RGS
1216share($rl);
1217share($warnLevel);
1218share($dieLevel);
1219share($signalLevel);
1220share($pre);
1221share($post);
1222share($pretype);
1223share($rl);
1224share($CreateTTY);
1225share($CommandSet);
1226
69893cff
RGS
1227=pod
1228
1229The default C<die>, C<warn>, and C<signal> handlers are set up.
1230
1231=cut
055fd3a9 1232
d338d6fe 1233warnLevel($warnLevel);
1234dieLevel($dieLevel);
1235signalLevel($signalLevel);
055fd3a9 1236
69893cff
RGS
1237=pod
1238
1239The pager to be used is needed next. We try to get it from the
1240environment first. if it's not defined there, we try to find it in
1241the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1242then call the C<pager()> function to save the pager name.
1243
1244=cut
1245
1246# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1247pager(
e22ea7cc 1248
69893cff 1249 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1250 defined $ENV{PAGER}
1251 ? $ENV{PAGER}
69893cff
RGS
1252
1253 # If not, see if Config.pm defines it.
e22ea7cc
RF
1254 : eval { require Config }
1255 && defined $Config::Config{pager}
1256 ? $Config::Config{pager}
69893cff
RGS
1257
1258 # If not, fall back to 'more'.
e22ea7cc
RF
1259 : 'more'
1260 )
1261 unless defined $pager;
69893cff
RGS
1262
1263=pod
1264
1265We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1266recall character (C<!> unless otherwise defined) and the shell escape
1267character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1268neither works in the debugger at the moment.
1269
1270=cut
1271
055fd3a9 1272setman();
69893cff
RGS
1273
1274# Set up defaults for command recall and shell escape (note:
1275# these currently don't work in linemode debugging).
d338d6fe 1276&recallCommand("!") unless defined $prc;
69893cff
RGS
1277&shellBang("!") unless defined $psh;
1278
1279=pod
1280
1281We then set up the gigantic string containing the debugger help.
1282We also set the limit on the number of arguments we'll display during a
1283trace.
1284
1285=cut
1286
04e43a21 1287sethelp();
69893cff
RGS
1288
1289# If we didn't get a default for the length of eval/stack trace args,
1290# set it here.
1d06cb2d 1291$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1292
1293=head2 SETTING UP THE DEBUGGER GREETING
1294
be9a9b1d 1295The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1296running, and whether the current debugger is the primary or a child.
1297
1298If we are the primary, we just hang onto our pid so we'll have it when
1299or if we start a child debugger. If we are a child, we'll set things up
1300so we'll have a unique greeting and so the parent will give us our own
1301TTY later.
1302
1303We save the current contents of the C<PERLDB_PIDS> environment variable
1304because we mess around with it. We'll also need to hang onto it because
1305we'll need it if we restart.
1306
1307Child debuggers make a label out of the current PID structure recorded in
1308PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1309yet so the parent will give them one later via C<resetterm()>.
1310
1311=cut
1312
e22ea7cc 1313# Save the current contents of the environment; we're about to
69893cff 1314# much with it. We'll need this if we have to restart.
f1583d8f 1315$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1316
e22ea7cc
RF
1317if ( defined $ENV{PERLDB_PIDS} ) {
1318
69893cff 1319 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1320 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1321 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1322
1323 my $env_pids = $ENV{PERLDB_PIDS};
1324 $pids = "[$env_pids]";
1325
1326 # Unless we are on OpenVMS, all programs under the DCL shell run under
1327 # the same PID.
1328
1329 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1330 $term_pid = $$;
1331 }
1332 else {
1333 $ENV{PERLDB_PIDS} .= "->$$";
1334 $term_pid = -1;
1335 }
1336
69893cff
RGS
1337} ## end if (defined $ENV{PERLDB_PIDS...
1338else {
e22ea7cc
RF
1339
1340 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1341 # child debugger, and mark us as the parent, so we'll know to set up
1342 # more TTY's is we have to.
1343 $ENV{PERLDB_PIDS} = "$$";
619a0444 1344 $pids = "[pid=$$]";
e22ea7cc 1345 $term_pid = $$;
f1583d8f 1346}
69893cff 1347
f1583d8f 1348$pidprompt = '';
69893cff
RGS
1349
1350# Sets up $emacs as a synonym for $slave_editor.
1351*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1352
1353=head2 READING THE RC FILE
1354
1355The debugger will read a file of initialization options if supplied. If
1356running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1357
1358=cut
1359
1360# As noted, this test really doesn't check accurately that the debugger
1361# is running at a terminal or not.
d338d6fe 1362
e22ea7cc
RF
1363if ( -e "/dev/tty" ) { # this is the wrong metric!
1364 $rcfile = ".perldb";
1365}
69893cff
RGS
1366else {
1367 $rcfile = "perldb.ini";
d338d6fe 1368}
1369
69893cff
RGS
1370=pod
1371
1372The debugger does a safety test of the file to be read. It must be owned
1373either by the current user or root, and must only be writable by the owner.
1374
1375=cut
1376
1377# This wraps a safety test around "do" to read and evaluate the init file.
1378#
055fd3a9
GS
1379# This isn't really safe, because there's a race
1380# between checking and opening. The solution is to
1381# open and fstat the handle, but then you have to read and
1382# eval the contents. But then the silly thing gets
69893cff
RGS
1383# your lexical scope, which is unfortunate at best.
1384sub safe_do {
055fd3a9
GS
1385 my $file = shift;
1386
1387 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1388 local $SIG{__WARN__};
1389 local $SIG{__DIE__};
055fd3a9 1390
e22ea7cc 1391 unless ( is_safe_file($file) ) {
69893cff 1392 CORE::warn <<EO_GRIPE;
055fd3a9
GS
1393perldb: Must not source insecure rcfile $file.
1394 You or the superuser must be the owner, and it must not
69893cff 1395 be writable by anyone but its owner.
055fd3a9 1396EO_GRIPE
69893cff
RGS
1397 return;
1398 } ## end unless (is_safe_file($file...
055fd3a9
GS
1399
1400 do $file;
1401 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1402} ## end sub safe_do
055fd3a9 1403
69893cff
RGS
1404# This is the safety test itself.
1405#
055fd3a9
GS
1406# Verifies that owner is either real user or superuser and that no
1407# one but owner may write to it. This function is of limited use
1408# when called on a path instead of upon a handle, because there are
1409# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1410# eventually accessed is the same as the one tested.
055fd3a9
GS
1411# Assumes that the file's existence is not in doubt.
1412sub is_safe_file {
1413 my $path = shift;
69893cff 1414 stat($path) || return; # mysteriously vaporized
e22ea7cc 1415 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1416
1417 return 0 if $uid != 0 && $uid != $<;
1418 return 0 if $mode & 022;
1419 return 1;
69893cff 1420} ## end sub is_safe_file
055fd3a9 1421
69893cff 1422# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1423# exists, we safely do it.
1424if ( -f $rcfile ) {
055fd3a9 1425 safe_do("./$rcfile");
69893cff 1426}
e22ea7cc 1427
69893cff 1428# If there isn't one here, try the user's home directory.
e22ea7cc 1429elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1430 safe_do("$ENV{HOME}/$rcfile");
1431}
e22ea7cc 1432
69893cff 1433# Else try the login directory.
e22ea7cc 1434elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1435 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe 1436}
1437
69893cff 1438# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1439if ( defined $ENV{PERLDB_OPTS} ) {
1440 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe 1441}
1442
69893cff
RGS
1443=pod
1444
1445The last thing we do during initialization is determine which subroutine is
1446to be used to obtain a new terminal when a new debugger is started. Right now,
6fae1ad7 1447the debugger only handles X Windows, OS/2, and Mac OS X (darwin).
69893cff
RGS
1448
1449=cut
1450
1451# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1452# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1453# OS/2, or on Mac OS X. This may need some expansion.
1454
1455if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1456{
6fae1ad7
RF
1457 if (defined $ENV{TERM} # If we know what kind
1458 # of terminal this is,
1459 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1460 and defined $ENV{DISPLAY} # and what display it's on,
1461 )
1462 {
1463 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1464 }
1465 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1466 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1467 }
1468 elsif ( $^O eq 'darwin' # If this is Mac OS X
1469 and defined $ENV{TERM_PROGRAM} # and we're running inside
1470 and $ENV{TERM_PROGRAM}
1471 eq 'Apple_Terminal' # Terminal.app
1472 )
1473 {
1474 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1475 }
69893cff 1476} ## end if (not defined &get_fork_TTY...
e22ea7cc 1477
dbb46cec
DQ
1478# untaint $^O, which may have been tainted by the last statement.
1479# see bug [perl #24674]
e22ea7cc
RF
1480$^O =~ m/^(.*)\z/;
1481$^O = $1;
f1583d8f 1482
d12a4851 1483# Here begin the unreadable code. It needs fixing.
055fd3a9 1484
69893cff
RGS
1485=head2 RESTART PROCESSING
1486
1487This section handles the restart command. When the C<R> command is invoked, it
1488tries to capture all of the state it can into environment variables, and
1489then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1490if C<PERLDB_RESTART> is there; if so, we reload all the information that
1491the R command stuffed into the environment variables.
1492
1493 PERLDB_RESTART - flag only, contains no restart data itself.
1494 PERLDB_HIST - command history, if it's available
1495 PERLDB_ON_LOAD - breakpoints set by the rc file
1496 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1497 PERLDB_VISITED - files that had breakpoints
1498 PERLDB_FILE_... - breakpoints for a file
1499 PERLDB_OPT - active options
1500 PERLDB_INC - the original @INC
1501 PERLDB_PRETYPE - preprompt debugger actions
1502 PERLDB_PRE - preprompt Perl code
1503 PERLDB_POST - post-prompt Perl code
1504 PERLDB_TYPEAHEAD - typeahead captured by readline()
1505
1506We chug through all these variables and plug the values saved in them
1507back into the appropriate spots in the debugger.
1508
1509=cut
1510
e22ea7cc
RF
1511if ( exists $ENV{PERLDB_RESTART} ) {
1512
69893cff 1513 # We're restarting, so we don't need the flag that says to restart anymore.
e22ea7cc
RF
1514 delete $ENV{PERLDB_RESTART};
1515
1516 # $restart = 1;
1517 @hist = get_list('PERLDB_HIST');
1518 %break_on_load = get_list("PERLDB_ON_LOAD");
1519 %postponed = get_list("PERLDB_POSTPONE");
69893cff 1520
2cbb2ee1
RGS
1521 share(@hist);
1522 share(@truehist);
1523 share(%break_on_load);
1524 share(%postponed);
1525
69893cff 1526 # restore breakpoints/actions
e22ea7cc
RF
1527 my @had_breakpoints = get_list("PERLDB_VISITED");
1528 for ( 0 .. $#had_breakpoints ) {
1529 my %pf = get_list("PERLDB_FILE_$_");
1530 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf;
1531 }
69893cff
RGS
1532
1533 # restore options
e22ea7cc
RF
1534 my %opt = get_list("PERLDB_OPT");
1535 my ( $opt, $val );
1536 while ( ( $opt, $val ) = each %opt ) {
1537 $val =~ s/[\\\']/\\$1/g;
1538 parse_options("$opt'$val'");
1539 }
69893cff
RGS
1540
1541 # restore original @INC
e22ea7cc
RF
1542 @INC = get_list("PERLDB_INC");
1543 @ini_INC = @INC;
1544
1545 # return pre/postprompt actions and typeahead buffer
1546 $pretype = [ get_list("PERLDB_PRETYPE") ];
1547 $pre = [ get_list("PERLDB_PRE") ];
1548 $post = [ get_list("PERLDB_POST") ];
1549 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1550} ## end if (exists $ENV{PERLDB_RESTART...
1551
1552=head2 SETTING UP THE TERMINAL
1553
1554Now, we'll decide how the debugger is going to interact with the user.
1555If there's no TTY, we set the debugger to run non-stop; there's not going
1556to be anyone there to enter commands.
1557
1558=cut
54d04a52 1559
d338d6fe 1560if ($notty) {
69893cff 1561 $runnonstop = 1;
2cbb2ee1 1562 share($runnonstop);
69893cff 1563}
d12a4851 1564
69893cff
RGS
1565=pod
1566
1567If there is a TTY, we have to determine who it belongs to before we can
1568proceed. If this is a slave editor or graphical debugger (denoted by
1569the first command-line switch being '-emacs'), we shift this off and
1570set C<$rl> to 0 (XXX ostensibly to do straight reads).
1571
1572=cut
1573
1574else {
e22ea7cc 1575
69893cff
RGS
1576 # Is Perl being run from a slave editor or graphical debugger?
1577 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1578 $slave_editor =
1579 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1580 $rl = 0, shift(@main::ARGV) if $slave_editor;
1581
1582 #require Term::ReadLine;
d12a4851 1583
69893cff
RGS
1584=pod
1585
1586We then determine what the console should be on various systems:
1587
1588=over 4
1589
1590=item * Cygwin - We use C<stdin> instead of a separate device.
1591
1592=cut
1593
e22ea7cc
RF
1594 if ( $^O eq 'cygwin' ) {
1595
69893cff
RGS
1596 # /dev/tty is binary. use stdin for textmode
1597 undef $console;
1598 }
1599
1600=item * Unix - use C</dev/tty>.
1601
1602=cut
1603
e22ea7cc 1604 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1605 $console = "/dev/tty";
1606 }
1607
1608=item * Windows or MSDOS - use C<con>.
1609
1610=cut
1611
e22ea7cc 1612 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1613 $console = "con";
1614 }
1615
1616=item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev:
be9a9b1d
AT
1617Console> if not.
1618
1619Note 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
1620
1621=cut
1622
e22ea7cc
RF
1623 elsif ( $^O eq 'MacOS' ) {
1624 if ( $MacPerl::Version !~ /MPW/ ) {
1625 $console =
1626 "Dev:Console:Perl Debug"; # Separate window for application
69893cff
RGS
1627 }
1628 else {
1629 $console = "Dev:Console";
1630 }
1631 } ## end elsif ($^O eq 'MacOS')
1632
1633=item * VMS - use C<sys$command>.
1634
1635=cut
1636
1637 else {
e22ea7cc 1638
69893cff
RGS
1639 # everything else is ...
1640 $console = "sys\$command";
d12a4851 1641 }
69893cff
RGS
1642
1643=pod
1644
1645=back
1646
1647Several other systems don't use a specific console. We C<undef $console>
1648for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1649with a slave editor, Epoc).
1650
1651=cut
d12a4851 1652
e22ea7cc
RF
1653 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1654
69893cff 1655 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1656 $console = undef;
1657 }
1658
1659 if ( $^O eq 'NetWare' ) {
d12a4851 1660
69893cff
RGS
1661 # /dev/tty is binary. use stdin for textmode
1662 $console = undef;
1663 }
d12a4851 1664
69893cff
RGS
1665 # In OS/2, we need to use STDIN to get textmode too, even though
1666 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1667 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1668 { # In OS/2
1669 $console = undef;
1670 }
1671
1672 # EPOC also falls into the 'got to use STDIN' camp.
1673 if ( $^O eq 'epoc' ) {
1674 $console = undef;
1675 }
d12a4851 1676
69893cff
RGS
1677=pod
1678
1679If there is a TTY hanging around from a parent, we use that as the console.
1680
1681=cut
1682
e22ea7cc 1683 $console = $tty if defined $tty;
d12a4851 1684
69893cff
RGS
1685=head2 SOCKET HANDLING
1686
1687The debugger is capable of opening a socket and carrying out a debugging
1688session over the socket.
1689
1690If C<RemotePort> was defined in the options, the debugger assumes that it
1691should try to start a debugging session on that port. It builds the socket
1692and then tries to connect the input and output filehandles to it.
1693
1694=cut
1695
1696 # Handle socket stuff.
e22ea7cc
RF
1697
1698 if ( defined $remoteport ) {
1699
69893cff
RGS
1700 # If RemotePort was defined in the options, connect input and output
1701 # to the socket.
e22ea7cc
RF
1702 require IO::Socket;
1703 $OUT = new IO::Socket::INET(
1704 Timeout => '10',
1705 PeerAddr => $remoteport,
1706 Proto => 'tcp',
69893cff 1707 );
e22ea7cc
RF
1708 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; }
1709 $IN = $OUT;
69893cff
RGS
1710 } ## end if (defined $remoteport)
1711
1712=pod
1713
1714If no C<RemotePort> was defined, and we want to create a TTY on startup,
1715this is probably a situation where multiple debuggers are running (for example,
1716a backticked command that starts up another debugger). We create a new IN and
1717OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1718and if we can.
1719
1720=cut
1721
1722 # Non-socket.
1723 else {
e22ea7cc 1724
69893cff
RGS
1725 # Two debuggers running (probably a system or a backtick that invokes
1726 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1727 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1728 # know how, and we can.
e22ea7cc
RF
1729 create_IN_OUT(4) if $CreateTTY & 4;
1730 if ($console) {
1731
69893cff 1732 # If we have a console, check to see if there are separate ins and
cd1191f1 1733 # outs to open. (They are assumed identical if not.)
69893cff 1734
e22ea7cc
RF
1735 my ( $i, $o ) = split /,/, $console;
1736 $o = $i unless defined $o;
69893cff 1737
69893cff 1738 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1739 open( IN, "+<$i" )
1740 || open( IN, "<$i" )
1741 || open( IN, "<&STDIN" );
1742
69893cff
RGS
1743 # read/write/create/clobber out, or write/create/clobber out,
1744 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1745 open( OUT, "+>$o" )
1746 || open( OUT, ">$o" )
1747 || open( OUT, ">&STDERR" )
1748 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1749
1750 } ## end if ($console)
1751 elsif ( not defined $console ) {
1752
1753 # No console. Open STDIN.
1754 open( IN, "<&STDIN" );
1755
1756 # merge with STDERR, or with STDOUT.
1757 open( OUT, ">&STDERR" )
1758 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1759 $console = 'STDIN/OUT';
69893cff
RGS
1760 } ## end elsif (not defined $console)
1761
1762 # Keep copies of the filehandles so that when the pager runs, it
1763 # can close standard input without clobbering ours.
e22ea7cc
RF
1764 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1765 } ## end elsif (from if(defined $remoteport))
1766
1767 # Unbuffer DB::OUT. We need to see responses right away.
1768 my $previous = select($OUT);
1769 $| = 1; # for DB::OUT
1770 select($previous);
1771
1772 # Line info goes to debugger output unless pointed elsewhere.
1773 # Pointing elsewhere makes it possible for slave editors to
1774 # keep track of file and position. We have both a filehandle
1775 # and a I/O description to keep track of.
1776 $LINEINFO = $OUT unless defined $LINEINFO;
1777 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1
RGS
1778 # share($LINEINFO); # <- unable to share globs
1779 share($lineinfo); #
e22ea7cc 1780
69893cff
RGS
1781=pod
1782
1783To finish initialization, we show the debugger greeting,
1784and then call the C<afterinit()> subroutine if there is one.
1785
1786=cut
d12a4851 1787
e22ea7cc
RF
1788 # Show the debugger greeting.
1789 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1790 unless ($runnonstop) {
1791 local $\ = '';
1792 local $, = '';
1793 if ( $term_pid eq '-1' ) {
1794 print $OUT "\nDaughter DB session started...\n";
1795 }
1796 else {
1797 print $OUT "\nLoading DB routines from $header\n";
1798 print $OUT (
1799 "Editor support ",
1800 $slave_editor ? "enabled" : "available", ".\n"
1801 );
1802 print $OUT
69893cff
RGS
1803"\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n";
1804 } ## end else [ if ($term_pid eq '-1')
1805 } ## end unless ($runnonstop)
1806} ## end else [ if ($notty)
1807
1808# XXX This looks like a bug to me.
1809# Why copy to @ARGS and then futz with @args?
d338d6fe 1810@ARGS = @ARGV;
1811for (@args) {
69893cff
RGS
1812 # Make sure backslashes before single quotes are stripped out, and
1813 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1814 # s/\'/\\\'/g; # removed while not justified understandably
1815 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
d338d6fe 1816}
1817
e22ea7cc 1818# If there was an afterinit() sub defined, call it. It will get
69893cff 1819# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1820if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1821 &afterinit();
d338d6fe 1822}
e22ea7cc 1823
69893cff 1824# Inform us about "Stack dump during die enabled ..." in dieLevel().
43aed9ee
IZ
1825$I_m_init = 1;
1826
d338d6fe 1827############################################################ Subroutines
1828
69893cff
RGS
1829=head1 SUBROUTINES
1830
1831=head2 DB
1832
1833This gigantic subroutine is the heart of the debugger. Called before every
1834statement, its job is to determine if a breakpoint has been reached, and
1835stop if so; read commands from the user, parse them, and execute
1836them, and hen send execution off to the next statement.
1837
1838Note that the order in which the commands are processed is very important;
1839some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1840to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1841but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1842see what's happening in any given command.
1843
1844=cut
1845
d338d6fe 1846sub DB {
69893cff 1847
2cbb2ee1
RGS
1848 # lock the debugger and get the thread id for the prompt
1849 lock($DBGR);
1850 my $tid;
1851 if ($ENV{PERL5DB_THREADED}) {
1852 $tid = eval { "[".threads->self->tid."]" };
1853 }
1854
69893cff 1855 # Check for whether we should be running continuously or not.
36477c24 1856 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1857 if ( $single and not $second_time++ ) {
1858
69893cff 1859 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1860 if ($runnonstop) { # Disable until signal
1861 # If there's any call stack in place, turn off single
1862 # stepping into subs throughout the stack.
1863 for ( $i = 0 ; $i <= $stack_depth ; ) {
1864 $stack[ $i++ ] &= ~1;
1865 }
1866
69893cff 1867 # And we are now no longer in single-step mode.
e22ea7cc 1868 $single = 0;
69893cff
RGS
1869
1870 # If we simply returned at this point, we wouldn't get
1871 # the trace info. Fall on through.
e22ea7cc 1872 # return;
69893cff
RGS
1873 } ## end if ($runnonstop)
1874
e22ea7cc
RF
1875 elsif ($ImmediateStop) {
1876
1877 # We are supposed to stop here; XXX probably a break.
1878 $ImmediateStop = 0; # We've processed it; turn it off
1879 $signal = 1; # Simulate an interrupt to force
1880 # us into the command loop
69893cff
RGS
1881 }
1882 } ## end if ($single and not $second_time...
1883
1884 # If we're in single-step mode, or an interrupt (real or fake)
1885 # has occurred, turn off non-stop mode.
1886 $runnonstop = 0 if $single or $signal;
1887
1888 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1889 # The code being debugged may have altered them.
d338d6fe 1890 &save;
69893cff
RGS
1891
1892 # Since DB::DB gets called after every line, we can use caller() to
1893 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1894 # caller is returning all the extra information when called from the
69893cff 1895 # debugger.
e22ea7cc 1896 local ( $package, $filename, $line ) = caller;
471505cc 1897 local $filename_ini = $filename;
69893cff
RGS
1898
1899 # set up the context for DB::eval, so it can properly execute
1900 # code on behalf of the user. We add the package in so that the
1901 # code is eval'ed in the proper package (not in the debugger!).
1902 local $usercontext =
e22ea7cc 1903 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;";
69893cff
RGS
1904
1905 # Create an alias to the active file magical array to simplify
1906 # the code here.
e22ea7cc 1907 local (*dbline) = $main::{ '_<' . $filename };
aa057b67
CN
1908
1909 # we need to check for pseudofiles on Mac OS (these are files
1910 # not attached to a filename, but instead stored in Dev:Pseudo)
e22ea7cc
RF
1911 if ( $^O eq 'MacOS' && $#dbline < 0 ) {
1912 $filename_ini = $filename = 'Dev:Pseudo';
1913 *dbline = $main::{ '_<' . $filename };
aa057b67
CN
1914 }
1915
69893cff 1916 # Last line in the program.
471505cc 1917 local $max = $#dbline;
69893cff
RGS
1918
1919 # if we have something here, see if we should break.
e22ea7cc
RF
1920 if ( $dbline{$line}
1921 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1922 {
1923
69893cff 1924 # Stop if the stop criterion says to just stop.
e22ea7cc 1925 if ( $stop eq '1' ) {
69893cff
RGS
1926 $signal |= 1;
1927 }
e22ea7cc 1928
69893cff
RGS
1929 # It's a conditional stop; eval it in the user's context and
1930 # see if we should stop. If so, remove the one-time sigil.
1931 elsif ($stop) {
e22ea7cc 1932 $evalarg = "\$DB::signal |= 1 if do {$stop}";
69893cff
RGS
1933 &eval;
1934 $dbline{$line} =~ s/;9($|\0)/$1/;
1935 }
1936 } ## end if ($dbline{$line} && ...
1937
1938 # Preserve the current stop-or-not, and see if any of the W
1939 # (watch expressions) has changed.
36477c24 1940 my $was_signal = $signal;
69893cff
RGS
1941
1942 # If we have any watch expressions ...
e22ea7cc
RF
1943 if ( $trace & 2 ) {
1944 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) {
1945 $evalarg = $to_watch[$n];
1946 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1947
1948 # Fix context DB::eval() wants to return an array, but
1949 # we need a scalar here.
e22ea7cc
RF
1950 my ($val) = join( "', '", &eval );
1951 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1952
1953 # Did it change?
e22ea7cc
RF
1954 if ( $val ne $old_watch[$n] ) {
1955
69893cff 1956 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1957 $signal = 1;
1958 print $OUT <<EOP;
405ff068 1959Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1960 old value:\t$old_watch[$n]
1961 new value:\t$val
6027b9a3 1962EOP
e22ea7cc 1963 $old_watch[$n] = $val;
69893cff
RGS
1964 } ## end if ($val ne $old_watch...
1965 } ## end for (my $n = 0 ; $n <= ...
1966 } ## end if ($trace & 2)
1967
1968=head2 C<watchfunction()>
1969
1970C<watchfunction()> is a function that can be defined by the user; it is a
1971function which will be run on each entry to C<DB::DB>; it gets the
1972current package, filename, and line as its parameters.
1973
1974The watchfunction can do anything it likes; it is executing in the
1975debugger's context, so it has access to all of the debugger's internal
1976data structures and functions.
1977
1978C<watchfunction()> can control the debugger's actions. Any of the following
1979will cause the debugger to return control to the user's program after
1980C<watchfunction()> executes:
1981
1982=over 4
1983
be9a9b1d
AT
1984=item *
1985
1986Returning a false value from the C<watchfunction()> itself.
1987
1988=item *
1989
1990Altering C<$single> to a false value.
1991
1992=item *
69893cff 1993
be9a9b1d 1994Altering C<$signal> to a false value.
69893cff 1995
be9a9b1d 1996=item *
69893cff 1997
be9a9b1d 1998Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1999check for C<watchfunction()>. This can be done with
2000
2001 $trace &= ~4;
2002
2003=back
2004
2005=cut
2006
e22ea7cc 2007 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2008 # current package, filename, and line. The function executes in
2009 # the DB:: package.
e22ea7cc
RF
2010 if ( $trace & 4 ) { # User-installed watch
2011 return
2012 if watchfunction( $package, $filename, $line )
2013 and not $single
2014 and not $was_signal
2015 and not( $trace & ~4 );
69893cff
RGS
2016 } ## end if ($trace & 4)
2017
e22ea7cc 2018 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2019 # turn off the signal now.
6027b9a3 2020 $was_signal = $signal;
69893cff
RGS
2021 $signal = 0;
2022
2023=head2 GETTING READY TO EXECUTE COMMANDS
2024
2025The debugger decides to take control if single-step mode is on, the
2026C<t> command was entered, or the user generated a signal. If the program
2027has fallen off the end, we set things up so that entering further commands
2028won't cause trouble, and we say that the program is over.
2029
2030=cut
2031
2032 # Check to see if we should grab control ($single true,
2033 # trace set appropriately, or we got a signal).
e22ea7cc
RF
2034 if ( $single || ( $trace & 1 ) || $was_signal ) {
2035
69893cff 2036 # Yes, grab control.
e22ea7cc
RF
2037 if ($slave_editor) {
2038
69893cff 2039 # Tell the editor to update its position.
e22ea7cc
RF
2040 $position = "\032\032$filename:$line:0\n";
2041 print_lineinfo($position);
2042 }
69893cff
RGS
2043
2044=pod
2045
2046Special check: if we're in package C<DB::fake>, we've gone through the
2047C<END> block at least once. We set up everything so that we can continue
2048to enter commands and have a valid context to be in.
2049
2050=cut
2051
e22ea7cc 2052 elsif ( $package eq 'DB::fake' ) {
69893cff 2053
69893cff 2054 # Fallen off the end already.
e22ea7cc
RF
2055 $term || &setterm;
2056 print_help(<<EOP);
405ff068 2057Debugged program terminated. Use B<q> to quit or B<R> to restart,
6b27b0a0
BD
2058 use B<o> I<inhibit_exit> to avoid stopping after program termination,
2059 B<h q>, B<h R> or B<h o> to get additional info.
405ff068 2060EOP
e22ea7cc 2061
69893cff 2062 # Set the DB::eval context appropriately.
e22ea7cc
RF
2063 $package = 'main';
2064 $usercontext =
2065 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
2066 . "package $package;"; # this won't let them modify, alas
69893cff 2067 } ## end elsif ($package eq 'DB::fake')
e219e2fb 2068
69893cff 2069=pod
e219e2fb 2070
69893cff
RGS
2071If the program hasn't finished executing, we scan forward to the
2072next executable line, print that out, build the prompt from the file and line
2073number information, and print that.
e219e2fb 2074
69893cff
RGS
2075=cut
2076
e22ea7cc
RF
2077 else {
2078
69893cff
RGS
2079 # Still somewhere in the midst of execution. Set up the
2080 # debugger prompt.
2081 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 2082 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
2083 #module names)
2084
e22ea7cc
RF
2085 $prefix = $sub =~ /::/ ? "" : "${'package'}::";
2086 $prefix .= "$sub($filename:";
2087 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2088
2089 # Break up the prompt if it's really long.
e22ea7cc
RF
2090 if ( length($prefix) > 30 ) {
2091 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2092 $prefix = "";
2093 $infix = ":\t";
2094 }
2095 else {
2096 $infix = "):\t";
2097 $position = "$prefix$line$infix$dbline[$line]$after";
2098 }
69893cff
RGS
2099
2100 # Print current line info, indenting if necessary.
e22ea7cc
RF
2101 if ($frame) {
2102 print_lineinfo( ' ' x $stack_depth,
2103 "$line:\t$dbline[$line]$after" );
2104 }
2105 else {
2106 print_lineinfo($position);
2107 }
69893cff
RGS
2108
2109 # Scan forward, stopping at either the end or the next
2110 # unbreakable line.
e22ea7cc
RF
2111 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
2112 { #{ vi
69893cff
RGS
2113
2114 # Drop out on null statements, block closers, and comments.
2115 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2116
2117 # Drop out if the user interrupted us.
2118 last if $signal;
2119
2120 # Append a newline if the line doesn't have one. Can happen
2121 # in eval'ed text, for instance.
e22ea7cc 2122 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2123
2124 # Next executable line.
2125 $incr_pos = "$prefix$i$infix$dbline[$i]$after";
2126 $position .= $incr_pos;
2127 if ($frame) {
e22ea7cc 2128
69893cff 2129 # Print it indented if tracing is on.
e22ea7cc
RF
2130 print_lineinfo( ' ' x $stack_depth,
2131 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2132 }
2133 else {
2134 print_lineinfo($incr_pos);
2135 }
2136 } ## end for ($i = $line + 1 ; $i...
2137 } ## end else [ if ($slave_editor)
2138 } ## end if ($single || ($trace...
2139
2140=pod
2141
2142If there's an action to be executed for the line we stopped at, execute it.
2143If there are any preprompt actions, execute those as well.
e219e2fb
RF
2144
2145=cut
2146
69893cff
RGS
2147 # If there's an action, do it now.
2148 $evalarg = $action, &eval if $action;
e219e2fb 2149
69893cff
RGS
2150 # Are we nested another level (e.g., did we evaluate a function
2151 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2152 if ( $single || $was_signal ) {
2153
69893cff 2154 # Yes, go down a level.
e22ea7cc 2155 local $level = $level + 1;
69893cff
RGS
2156
2157 # Do any pre-prompt actions.
e22ea7cc
RF
2158 foreach $evalarg (@$pre) {
2159 &eval;
2160 }
69893cff
RGS
2161
2162 # Complain about too much recursion if we passed the limit.
e22ea7cc 2163 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2164 if $single & 4;
2165
2166 # The line we're currently on. Set $incr to -1 to stay here
2167 # until we get a command that tells us to advance.
e22ea7cc
RF
2168 $start = $line;
2169 $incr = -1; # for backward motion.
69893cff
RGS
2170
2171 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2172 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2173
2174=head2 WHERE ARE WE?
2175
2176XXX Relocate this section?
2177
2178The debugger normally shows the line corresponding to the current line of
2179execution. Sometimes, though, we want to see the next line, or to move elsewhere
2180in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2181
be9a9b1d
AT
2182C<$incr> controls by how many lines the I<current> line should move forward
2183after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2184line shouldn't change.
2185
be9a9b1d 2186C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2187move forwards or backwards from when doing an C<L> or C<-> command.
2188
2189C<$max> tells the debugger where the last line of the current file is. It's
2190used to terminate loops most often.
2191
2192=head2 THE COMMAND LOOP
2193
2194Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2195in two parts:
2196
2197=over 4
2198
be9a9b1d
AT
2199=item *
2200
2201The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2202reads a command and then executes it.
2203
be9a9b1d
AT
2204=item *
2205
2206The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2207is wholly contained inside the C<CMD> block and only executes a command.
2208Used to handle commands running inside a pager.
2209
2210=back
2211
2212So why have two labels to restart the loop? Because sometimes, it's easier to
2213have a command I<generate> another command and then re-execute the loop to do
2214the new command. This is faster, but perhaps a bit more convoluted.
2215
2216=cut
2217
2218 # The big command dispatch loop. It keeps running until the
2219 # user yields up control again.
2220 #
2221 # If we have a terminal for input, and we get something back
2222 # from readline(), keep on processing.
e22ea7cc
RF
2223 CMD:
2224 while (
2225
69893cff 2226 # We have a terminal, or can get one ...
e22ea7cc
RF
2227 ( $term || &setterm ),
2228
69893cff 2229 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2230 ( $term_pid == $$ or resetterm(1) ),
2231
69893cff 2232 # ... and we got a line of command input ...
e22ea7cc
RF
2233 defined(
2234 $cmd = &readline(
2cbb2ee1 2235 "$pidprompt $tid DB"
e22ea7cc
RF
2236 . ( '<' x $level )
2237 . ( $#hist + 1 )
2238 . ( '>' x $level ) . " "
69893cff
RGS
2239 )
2240 )
2241 )
2242 {
e22ea7cc 2243
2cbb2ee1 2244 share($cmd);
69893cff
RGS
2245 # ... try to execute the input as debugger commands.
2246
2247 # Don't stop running.
2248 $single = 0;
2249
2250 # No signal is active.
2251 $signal = 0;
2252
2253 # Handle continued commands (ending with \):
e22ea7cc
RF
2254 $cmd =~ s/\\$/\n/ && do {
2255 $cmd .= &readline(" cont: ");
2256 redo CMD;
2257 };
69893cff
RGS
2258
2259=head4 The null command
2260
be9a9b1d 2261A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2262command out of C<$laststep> (where it was recorded previously), and copy it
2263back into C<$cmd> to be executed below. If there wasn't any previous command,
2264we'll do nothing below (no command will match). If there was, we also save it
2265in the command history and fall through to allow the command parsing to pick
2266it up.
2267
2268=cut
2269
2270 # Empty input means repeat the last command.
e22ea7cc
RF
2271 $cmd =~ /^$/ && ( $cmd = $laststep );
2272 chomp($cmd); # get rid of the annoying extra newline
2273 push( @hist, $cmd ) if length($cmd) > 1;
2274 push( @truehist, $cmd );
2cbb2ee1
RGS
2275 share(@hist);
2276 share(@truehist);
e22ea7cc
RF
2277
2278 # This is a restart point for commands that didn't arrive
2279 # via direct user input. It allows us to 'redo PIPE' to
2280 # re-execute command processing without reading a new command.
69893cff 2281 PIPE: {
e22ea7cc
RF
2282 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2283 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
2284 ($i) = split( /\s+/, $cmd );
69893cff
RGS
2285
2286=head3 COMMAND ALIASES
2287
2288The debugger can create aliases for commands (these are stored in the
2289C<%alias> hash). Before a command is executed, the command loop looks it up
2290in the alias hash and substitutes the contents of the alias for the command,
2291completely replacing it.
2292
2293=cut
2294
2295 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2296 if ( $alias{$i} ) {
2297
69893cff
RGS
2298 # Squelch signal handling; we want to keep control here
2299 # if something goes loco during the alias eval.
2300 local $SIG{__DIE__};
2301 local $SIG{__WARN__};
2302
2303 # This is a command, so we eval it in the DEBUGGER's
2304 # scope! Otherwise, we can't see the special debugger
2305 # variables, or get to the debugger's subs. (Well, we
2306 # _could_, but why make it even more complicated?)
2307 eval "\$cmd =~ $alias{$i}";
2308 if ($@) {
2309 local $\ = '';
2310 print $OUT "Couldn't evaluate `$i' alias: $@";
2311 next CMD;
2312 }
2313 } ## end if ($alias{$i})
2314
2315=head3 MAIN-LINE COMMANDS
2316
2317All of these commands work up to and after the program being debugged has
2318terminated.
2319
2320=head4 C<q> - quit
2321
2322Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
2323try to execute further, cleaning any restart-related stuff out of the
2324environment, and executing with the last value of C<$?>.
2325
2326=cut
2327
2328 $cmd =~ /^q$/ && do {
2329 $fall_off_end = 1;
2330 clean_ENV();
2331 exit $?;
2332 };
2333
2334=head4 C<t> - trace
2335
2336Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
2337
2338=cut
2339
e22ea7cc
RF
2340 $cmd =~ /^t$/ && do {
2341 $trace ^= 1;
2342 local $\ = '';
2343 print $OUT "Trace = "
2344 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n";
2345 next CMD;
2346 };
69893cff
RGS
2347
2348=head4 C<S> - list subroutines matching/not matching a pattern
2349
2350Walks through C<%sub>, checking to see whether or not to print the name.
2351
2352=cut
2353
e22ea7cc 2354 $cmd =~ /^S(\s+(!)?(.+))?$/ && do {
69893cff 2355
e22ea7cc 2356 $Srev = defined $2; # Reverse scan?
69893cff
RGS
2357 $Spatt = $3; # The pattern (if any) to use.
2358 $Snocheck = !defined $1; # No args - print all subs.
2359
2360 # Need to make these sane here.
e22ea7cc
RF
2361 local $\ = '';
2362 local $, = '';
69893cff
RGS
2363
2364 # Search through the debugger's magical hash of subs.
2365 # If $nocheck is true, just print the sub name.
2366 # Otherwise, check it against the pattern. We then use
2367 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2368 foreach $subname ( sort( keys %sub ) ) {
2369 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2370 print $OUT $subname, "\n";
2371 }
2372 }
2373 next CMD;
2374 };
69893cff
RGS
2375
2376=head4 C<X> - list variables in current package
2377
2378Since the C<V> command actually processes this, just change this to the
2379appropriate C<V> command and fall through.
2380
2381=cut
2382
e22ea7cc 2383 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2384
2385=head4 C<V> - list variables
2386
2387Uses C<dumpvar.pl> to dump out the current values for selected variables.
2388
2389=cut
2390
2391 # Bare V commands get the currently-being-debugged package
2392 # added.
e22ea7cc
RF
2393 $cmd =~ /^V$/ && do {
2394 $cmd = "V $package";
2395 };
69893cff
RGS
2396
2397 # V - show variables in package.
2398 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do {
e22ea7cc 2399
69893cff
RGS
2400 # Save the currently selected filehandle and
2401 # force output to debugger's filehandle (dumpvar
2402 # just does "print" for output).
e22ea7cc 2403 local ($savout) = select($OUT);
69893cff
RGS
2404
2405 # Grab package name and variables to dump.
e22ea7cc
RF
2406 $packname = $1;
2407 @vars = split( ' ', $2 );
69893cff
RGS
2408
2409 # If main::dumpvar isn't here, get it.
e22ea7cc
RF
2410 do 'dumpvar.pl' unless defined &main::dumpvar;
2411 if ( defined &main::dumpvar ) {
2412
69893cff
RGS
2413 # We got it. Turn off subroutine entry/exit messages
2414 # for the moment, along with return values.
e22ea7cc
RF
2415 local $frame = 0;
2416 local $doret = -2;
69893cff
RGS
2417
2418 # must detect sigpipe failures - not catching
2419 # then will cause the debugger to die.
2420 eval {
2421 &main::dumpvar(
2422 $packname,
2423 defined $option{dumpDepth}
e22ea7cc
RF
2424 ? $option{dumpDepth}
2425 : -1, # assume -1 unless specified
69893cff 2426 @vars
e22ea7cc
RF
2427 );
2428 };
2429
2430 # The die doesn't need to include the $@, because
2431 # it will automatically get propagated for us.
2432 if ($@) {
2433 die unless $@ =~ /dumpvar print failed/;
2434 }
2435 } ## end if (defined &main::dumpvar)
2436 else {
2437
2438 # Couldn't load dumpvar.
2439 print $OUT "dumpvar.pl not available.\n";
2440 }
69893cff 2441
69893cff 2442 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2443 select($savout);
2444 next CMD;
2445 };
69893cff
RGS
2446
2447=head4 C<x> - evaluate and print an expression
2448
2449Hands the expression off to C<DB::eval>, setting it up to print the value
2450via C<dumpvar.pl> instead of just printing it directly.
2451
2452=cut
2453
e22ea7cc
RF
2454 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval()
2455 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2456
2457 # handle special "x 3 blah" syntax XXX propagate
2458 # doc back to special variables.
e22ea7cc
RF
2459 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) {
2460 $onetimedumpDepth = $1;
2461 }
2462 };
69893cff
RGS
2463
2464=head4 C<m> - print methods
2465
2466Just uses C<DB::methods> to determine what methods are available.
2467
2468=cut
2469
e22ea7cc
RF
2470 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do {
2471 methods($1);
2472 next CMD;
2473 };
69893cff
RGS
2474
2475 # m expr - set up DB::eval to do the work
e22ea7cc
RF
2476 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval()
2477 $onetimeDump = 'methods'; # method output gets used there
2478 };
69893cff
RGS
2479
2480=head4 C<f> - switch files
2481
2482=cut
2483
e22ea7cc
RF
2484 $cmd =~ /^f\b\s*(.*)/ && do {
2485 $file = $1;
2486 $file =~ s/\s+$//;
69893cff
RGS
2487
2488 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2489 if ( !$file ) {
2490 print $OUT
2491 "The old f command is now the r command.\n"; # hint
2492 print $OUT "The new f command switches filenames.\n";
2493 next CMD;
2494 } ## end if (!$file)
69893cff
RGS
2495
2496 # if not in magic file list, try a close match.
e22ea7cc
RF
2497 if ( !defined $main::{ '_<' . $file } ) {
2498 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2499 {
2500 $try = substr( $try, 2 );
2501 print $OUT "Choosing $try matching `$file':\n";
2502 $file = $try;
2503 }
2504 } ## end if (($try) = grep(m#^_<.*$file#...
2505 } ## end if (!defined $main::{ ...
69893cff
RGS
2506
2507 # If not successfully switched now, we failed.
e22ea7cc
RF
2508 if ( !defined $main::{ '_<' . $file } ) {
2509 print $OUT "No file matching `$file' is loaded.\n";
2510 next CMD;
2511 }
69893cff 2512
e22ea7cc
RF
2513 # We switched, so switch the debugger internals around.
2514 elsif ( $file ne $filename ) {
2515 *dbline = $main::{ '_<' . $file };
2516 $max = $#dbline;
2517 $filename = $file;
2518 $start = 1;
2519 $cmd = "l";
2520 } ## end elsif ($file ne $filename)
2521
2522 # We didn't switch; say we didn't.
2523 else {
2524 print $OUT "Already in $file.\n";
2525 next CMD;
2526 }
2527 };
69893cff
RGS
2528
2529=head4 C<.> - return to last-executed line.
2530
2531We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2532and then we look up the line in the magical C<%dbline> hash.
2533
2534=cut
2535
2536 # . command.
e22ea7cc
RF
2537 $cmd =~ /^\.$/ && do {
2538 $incr = -1; # stay at current line
69893cff
RGS
2539
2540 # Reset everything to the old location.
e22ea7cc
RF
2541 $start = $line;
2542 $filename = $filename_ini;
2543 *dbline = $main::{ '_<' . $filename };
2544 $max = $#dbline;
69893cff
RGS
2545
2546 # Now where are we?
e22ea7cc
RF
2547 print_lineinfo($position);
2548 next CMD;
2549 };
69893cff
RGS
2550
2551=head4 C<-> - back one window
2552
2553We change C<$start> to be one window back; if we go back past the first line,
2554we set it to be the first line. We ser C<$incr> to put us back at the
2555currently-executing line, and then put a C<l $start +> (list one window from
2556C<$start>) in C<$cmd> to be executed later.
2557
2558=cut
2559
2560 # - - back a window.
e22ea7cc
RF
2561 $cmd =~ /^-$/ && do {
2562
69893cff 2563 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2564 $start -= $incr + $window + 1;
2565 $start = 1 if $start <= 0;
2566 $incr = $window - 1;
69893cff
RGS
2567
2568 # Generate and execute a "l +" command (handled below).
e22ea7cc
RF
2569 $cmd = 'l ' . ($start) . '+';
2570 };
69893cff
RGS
2571
2572=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>, {, {{>
2573
2574In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2575problems, most notably that the default case of several commands destroying
2576the user's work in setting watchpoints, actions, etc. We wanted, however, to
2577retain the old commands for those who were used to using them or who preferred
2578them. At this point, we check for the new commands and call C<cmd_wrapper> to
2579deal with them instead of processing them in-line.
2580
2581=cut
2582
2583 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2584 # we send them off to the secondary dispatcher (see below).
2cbb2ee1 2585 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do {
e22ea7cc
RF
2586 &cmd_wrapper( $1, $2, $line );
2587 next CMD;
2588 };
69893cff
RGS
2589
2590=head4 C<y> - List lexicals in higher scope
2591
2592Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
2593above the current one and then displays then using C<dumpvar.pl>.
2594
2595=cut
2596
2597 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do {
2598
2599 # See if we've got the necessary support.
2600 eval { require PadWalker; PadWalker->VERSION(0.08) }
2601 or &warn(
2602 $@ =~ /locate/
2603 ? "PadWalker module not found - please install\n"
2604 : $@
2605 )
2606 and next CMD;
2607
2608 # Load up dumpvar if we don't have it. If we can, that is.
2609 do 'dumpvar.pl' unless defined &main::dumpvar;
2610 defined &main::dumpvar
2611 or print $OUT "dumpvar.pl not available.\n"
2612 and next CMD;
2613
2614 # Got all the modules we need. Find them and print them.
e22ea7cc 2615 my @vars = split( ' ', $2 || '' );
69893cff
RGS
2616
2617 # Find the pad.
e22ea7cc 2618 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) };
69893cff
RGS
2619
2620 # Oops. Can't find it.
2621 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2622
2623 # Show the desired vars with dumplex().
2624 my $savout = select($OUT);
2625
2626 # Have dumplex dump the lexicals.
e22ea7cc 2627 dumpvar::dumplex( $_, $h->{$_},
69893cff 2628 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2629 @vars )
2630 for sort keys %$h;
69893cff
RGS
2631 select($savout);
2632 next CMD;
2633 };
2634
2635=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2636
2637All of the commands below this point don't work after the program being
2638debugged has ended. All of them check to see if the program has ended; this
2639allows the commands to be relocated without worrying about a 'line of
2640demarcation' above which commands can be entered anytime, and below which
2641they can't.
2642
2643=head4 C<n> - single step, but don't trace down into subs
2644
2645Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2646when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
69893cff
RGS
2647so a null command knows what to re-execute.
2648
2649=cut
2650
e22ea7cc 2651 # n - next
69893cff
RGS
2652 $cmd =~ /^n$/ && do {
2653 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2654
69893cff
RGS
2655 # Single step, but don't enter subs.
2656 $single = 2;
e22ea7cc 2657
69893cff 2658 # Save for empty command (repeat last).
e22ea7cc
RF
2659 $laststep = $cmd;
2660 last CMD;
2661 };
69893cff
RGS
2662
2663=head4 C<s> - single-step, entering subs
2664
be9a9b1d 2665Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2666subs. Also saves C<s> as C<$lastcmd>.
2667
2668=cut
2669
2670 # s - single step.
2671 $cmd =~ /^s$/ && do {
e22ea7cc 2672
69893cff
RGS
2673 # Get out and restart the command loop if program
2674 # has finished.
e22ea7cc
RF
2675 end_report(), next CMD if $finished and $level <= 1;
2676
69893cff 2677 # Single step should enter subs.
e22ea7cc
RF
2678 $single = 1;
2679
69893cff 2680 # Save for empty command (repeat last).
e22ea7cc
RF
2681 $laststep = $cmd;
2682 last CMD;
2683 };
69893cff
RGS
2684
2685=head4 C<c> - run continuously, setting an optional breakpoint
2686
2687Most of the code for this command is taken up with locating the optional
2688breakpoint, which is either a subroutine name or a line number. We set
2689the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2690in this and all call levels above this one.
2691
2692=cut
2693
2694 # c - start continuous execution.
2695 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do {
e22ea7cc 2696
69893cff
RGS
2697 # Hey, show's over. The debugged program finished
2698 # executing already.
2699 end_report(), next CMD if $finished and $level <= 1;
2700
2701 # Capture the place to put a one-time break.
2702 $subname = $i = $1;
2703
e22ea7cc
RF
2704 # Probably not needed, since we finish an interactive
2705 # sub-session anyway...
2706 # local $filename = $filename;
2707 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2708 #
2709 # The above question wonders if localizing the alias
2710 # to the magic array works or not. Since it's commented
2711 # out, we'll just leave that to speculation for now.
2712
2713 # If the "subname" isn't all digits, we'll assume it
2714 # is a subroutine name, and try to find it.
e22ea7cc
RF
2715 if ( $subname =~ /\D/ ) { # subroutine name
2716 # Qualify it to the current package unless it's
2717 # already qualified.
69893cff
RGS
2718 $subname = $package . "::" . $subname
2719 unless $subname =~ /::/;
e22ea7cc 2720
69893cff
RGS
2721 # find_sub will return "file:line_number" corresponding
2722 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2723 # break up the return value, and assign it in one
69893cff 2724 # operation.
e22ea7cc 2725 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2726
2727 # Force the line number to be numeric.
e22ea7cc 2728 $i += 0;
69893cff
RGS
2729
2730 # If we got a line number, we found the sub.
e22ea7cc
RF
2731 if ($i) {
2732
69893cff
RGS
2733 # Switch all the debugger's internals around so
2734 # we're actually working with that file.
e22ea7cc
RF
2735 $filename = $file;
2736 *dbline = $main::{ '_<' . $filename };
2737
69893cff 2738 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2739 $had_breakpoints{$filename} |= 1;
2740
69893cff
RGS
2741 # Scan forward to the first executable line
2742 # after the 'sub whatever' line.
e22ea7cc
RF
2743 $max = $#dbline;
2744 ++$i while $dbline[$i] == 0 && $i < $max;
2745 } ## end if ($i)
69893cff
RGS
2746
2747 # We didn't find a sub by that name.
e22ea7cc
RF
2748 else {
2749 print $OUT "Subroutine $subname not found.\n";
2750 next CMD;
2751 }
2752 } ## end if ($subname =~ /\D/)
69893cff
RGS
2753
2754 # At this point, either the subname was all digits (an
2755 # absolute line-break request) or we've scanned through
2756 # the code following the definition of the sub, looking
2757 # for an executable, which we may or may not have found.
2758 #
2759 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2760 # got a request to break at some line somewhere. On
2761 # one hand, if there wasn't any real subroutine name
2762 # involved, this will be a request to break in the current
2763 # file at the specified line, so we have to check to make
69893cff
RGS
2764 # sure that the line specified really is breakable.
2765 #
2766 # On the other hand, if there was a subname supplied, the
3c4b39be 2767 # preceding block has moved us to the proper file and
69893cff
RGS
2768 # location within that file, and then scanned forward
2769 # looking for the next executable line. We have to make
2770 # sure that one was found.
2771 #
2772 # On the gripping hand, we can't do anything unless the
2773 # current value of $i points to a valid breakable line.
2774 # Check that.
e22ea7cc
RF
2775 if ($i) {
2776
69893cff 2777 # Breakable?
e22ea7cc
RF
2778 if ( $dbline[$i] == 0 ) {
2779 print $OUT "Line $i not breakable.\n";
2780 next CMD;
2781 }
2782
69893cff 2783 # Yes. Set up the one-time-break sigil.
e22ea7cc
RF
2784 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2785 } ## end if ($i)
69893cff
RGS
2786
2787 # Turn off stack tracing from here up.
e22ea7cc
RF
2788 for ( $i = 0 ; $i <= $stack_depth ; ) {
2789 $stack[ $i++ ] &= ~1;
2790 }
2791 last CMD;
2792 };
69893cff
RGS
2793
2794=head4 C<r> - return from a subroutine
2795
2796For C<r> to work properly, the debugger has to stop execution again
2797immediately after the return is executed. This is done by forcing
2798single-stepping to be on in the call level above the current one. If
2799we are printing return values when a C<r> is executed, set C<$doret>
2800appropriately, and force us out of the command loop.
2801
2802=cut
2803
2804 # r - return from the current subroutine.
e22ea7cc
RF
2805 $cmd =~ /^r$/ && do {
2806
69893cff 2807 # Can't do anythign if the program's over.
e22ea7cc
RF
2808 end_report(), next CMD if $finished and $level <= 1;
2809
69893cff 2810 # Turn on stack trace.
e22ea7cc
RF
2811 $stack[$stack_depth] |= 1;
2812
69893cff 2813 # Print return value unless the stack is empty.
e22ea7cc
RF
2814 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2815 last CMD;
2816 };
69893cff 2817
69893cff
RGS
2818=head4 C<T> - stack trace
2819
2820Just calls C<DB::print_trace>.
2821
2822=cut
2823
e22ea7cc
RF
2824 $cmd =~ /^T$/ && do {
2825 print_trace( $OUT, 1 ); # skip DB
2826 next CMD;
2827 };
69893cff
RGS
2828
2829=head4 C<w> - List window around current line.
2830
2831Just calls C<DB::cmd_w>.
2832
2833=cut
2834
e22ea7cc 2835 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; };
69893cff
RGS
2836
2837=head4 C<W> - watch-expression processing.
2838
2839Just calls C<DB::cmd_W>.
2840
2841=cut
2842
e22ea7cc 2843 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; };
69893cff
RGS
2844
2845=head4 C</> - search forward for a string in the source
2846
2847We take the argument and treat it as a pattern. If it turns out to be a
2848bad one, we return the error we got from trying to C<eval> it and exit.
2849If not, we create some code to do the search and C<eval> it so it can't
2850mess us up.
2851
2852=cut
2853
e22ea7cc 2854 $cmd =~ /^\/(.*)$/ && do {
69893cff
RGS
2855
2856 # The pattern as a string.
e22ea7cc 2857 $inpat = $1;
69893cff
RGS
2858
2859 # Remove the final slash.
e22ea7cc 2860 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2861
2862 # If the pattern isn't null ...
e22ea7cc 2863 if ( $inpat ne "" ) {
69893cff
RGS
2864
2865 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2866 local $SIG{__DIE__};
2867 local $SIG{__WARN__};
69893cff
RGS
2868
2869 # Create the pattern.
e22ea7cc
RF
2870 eval '$inpat =~ m' . "\a$inpat\a";
2871 if ( $@ ne "" ) {
2872
69893cff 2873 # Oops. Bad pattern. No biscuit.
e22ea7cc 2874 # Print the eval error and go back for more
69893cff 2875 # commands.
e22ea7cc
RF
2876 print $OUT "$@";
2877 next CMD;
2878 }
2879 $pat = $inpat;
2880 } ## end if ($inpat ne "")
69893cff
RGS
2881
2882 # Set up to stop on wrap-around.
e22ea7cc 2883 $end = $start;
69893cff
RGS
2884
2885 # Don't move off the current line.
e22ea7cc 2886 $incr = -1;
69893cff
RGS
2887
2888 # Done in eval so nothing breaks if the pattern
2889 # does something weird.
e22ea7cc
RF
2890 eval '
2891 for (;;) {
69893cff 2892 # Move ahead one line.
e22ea7cc 2893 ++$start;
69893cff
RGS
2894
2895 # Wrap if we pass the last line.
e22ea7cc 2896 $start = 1 if ($start > $max);
69893cff
RGS
2897
2898 # Stop if we have gotten back to this line again,
e22ea7cc 2899 last if ($start == $end);
69893cff
RGS
2900
2901 # A hit! (Note, though, that we are doing
2902 # case-insensitive matching. Maybe a qr//
2903 # expression would be better, so the user could
2904 # do case-sensitive matching if desired.
e22ea7cc
RF
2905 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2906 if ($slave_editor) {
69893cff 2907 # Handle proper escaping in the slave.
e22ea7cc
RF
2908 print $OUT "\032\032$filename:$start:0\n";
2909 }
2910 else {
69893cff 2911 # Just print the line normally.
e22ea7cc
RF
2912 print $OUT "$start:\t",$dbline[$start],"\n";
2913 }
69893cff 2914 # And quit since we found something.
e22ea7cc
RF
2915 last;
2916 }
2917 } ';
2918
69893cff 2919 # If we wrapped, there never was a match.
e22ea7cc
RF
2920 print $OUT "/$pat/: not found\n" if ( $start == $end );
2921 next CMD;
2922 };
69893cff
RGS
2923
2924=head4 C<?> - search backward for a string in the source
2925
2926Same as for C</>, except the loop runs backwards.
2927
2928=cut
2929
2930 # ? - backward pattern search.
e22ea7cc 2931 $cmd =~ /^\?(.*)$/ && do {
69893cff
RGS
2932
2933 # Get the pattern, remove trailing question mark.
e22ea7cc
RF
2934 $inpat = $1;
2935 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2936
2937 # If we've got one ...
e22ea7cc 2938 if ( $inpat ne "" ) {
69893cff
RGS
2939
2940 # Turn off die & warn handlers.
e22ea7cc
RF
2941 local $SIG{__DIE__};
2942 local $SIG{__WARN__};
2943 eval '$inpat =~ m' . "\a$inpat\a";
2944
2945 if ( $@ ne "" ) {
2946
69893cff 2947 # Ouch. Not good. Print the error.
e22ea7cc
RF
2948 print $OUT $@;
2949 next CMD;
2950 }
2951 $pat = $inpat;
69893cff 2952 } ## end if ($inpat ne "")
e22ea7cc 2953
69893cff 2954 # Where we are now is where to stop after wraparound.
e22ea7cc 2955 $end = $start;
69893cff
RGS
2956
2957 # Don't move away from this line.
e22ea7cc 2958 $incr = -1;
69893cff
RGS
2959
2960 # Search inside the eval to prevent pattern badness
2961 # from killing us.
e22ea7cc
RF
2962 eval '
2963 for (;;) {
69893cff 2964 # Back up a line.
e22ea7cc 2965 --$start;
69893cff
RGS
2966
2967 # Wrap if we pass the first line.
e22ea7cc
RF
2968
2969 $start = $max if ($start <= 0);
69893cff
RGS
2970
2971 # Quit if we get back where we started,
e22ea7cc 2972 last if ($start == $end);
69893cff
RGS
2973
2974 # Match?
e22ea7cc
RF
2975 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2976 if ($slave_editor) {
69893cff 2977 # Yep, follow slave editor requirements.
e22ea7cc
RF
2978 print $OUT "\032\032$filename:$start:0\n";
2979 }
2980 else {
69893cff 2981 # Yep, just print normally.
e22ea7cc
RF
2982 print $OUT "$start:\t",$dbline[$start],"\n";
2983 }
69893cff
RGS
2984
2985 # Found, so done.
e22ea7cc
RF
2986 last;
2987 }
2988 } ';
2989
2990 # Say we failed if the loop never found anything,
2991 print $OUT "?$pat?: not found\n" if ( $start == $end );
2992 next CMD;
2993 };
69893cff
RGS
2994
2995=head4 C<$rc> - Recall command
2996
2997Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2998that the terminal supports history). It find the the command required, puts it
2999into C<$cmd>, and redoes the loop to execute it.
3000
3001=cut
3002
e22ea7cc
RF
3003 # $rc - recall command.
3004 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do {
69893cff
RGS
3005
3006 # No arguments, take one thing off history.
e22ea7cc 3007 pop(@hist) if length($cmd) > 1;
69893cff 3008
e22ea7cc 3009 # Relative (- found)?
69893cff 3010 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 3011 # N - go to that particular command slot or the last
69893cff 3012 # thing if nothing following.
e22ea7cc 3013 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist );
69893cff
RGS
3014
3015 # Pick out the command desired.
e22ea7cc 3016 $cmd = $hist[$i];
69893cff
RGS
3017
3018 # Print the command to be executed and restart the loop
3019 # with that command in the buffer.
e22ea7cc
RF
3020 print $OUT $cmd, "\n";
3021 redo CMD;
3022 };
69893cff
RGS
3023
3024=head4 C<$sh$sh> - C<system()> command
3025
3026Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
3027C<STDOUT> from getting messed up.
3028
3029=cut
3030
3031 # $sh$sh - run a shell command (if it's all ASCII).
3032 # Can't run shell commands with Unicode in the debugger, hmm.
e22ea7cc
RF
3033 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do {
3034
69893cff 3035 # System it.
e22ea7cc
RF
3036 &system($1);
3037 next CMD;
3038 };
69893cff
RGS
3039
3040=head4 C<$rc I<pattern> $rc> - Search command history
3041
3042Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3043If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3044
3045=cut
3046
e22ea7cc
RF
3047 # $rc pattern $rc - find a command in the history.
3048 $cmd =~ /^$rc([^$rc].*)$/ && do {
3049
69893cff 3050 # Create the pattern to use.
e22ea7cc 3051 $pat = "^$1";
69893cff
RGS
3052
3053 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 3054 pop(@hist) if length($cmd) > 1;
69893cff
RGS
3055
3056 # Look backward through the history.
e22ea7cc
RF
3057 for ( $i = $#hist ; $i ; --$i ) {
3058
69893cff 3059 # Stop if we find it.
e22ea7cc
RF
3060 last if $hist[$i] =~ /$pat/;
3061 }
3062
3063 if ( !$i ) {
69893cff 3064
69893cff 3065 # Never found it.
e22ea7cc
RF
3066 print $OUT "No such command!\n\n";
3067 next CMD;
3068 }
69893cff
RGS
3069
3070 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
3071 $cmd = $hist[$i];
3072 print $OUT $cmd, "\n";
3073 redo CMD;
3074 };
69893cff
RGS
3075
3076=head4 C<$sh> - Invoke a shell
3077
3078Uses C<DB::system> to invoke a shell.
3079
3080=cut
3081
3082 # $sh - start a shell.
e22ea7cc
RF
3083 $cmd =~ /^$sh$/ && do {
3084
69893cff
RGS
3085 # Run the user's shell. If none defined, run Bourne.
3086 # We resume execution when the shell terminates.
e22ea7cc
RF
3087 &system( $ENV{SHELL} || "/bin/sh" );
3088 next CMD;
3089 };
69893cff
RGS
3090
3091=head4 C<$sh I<command>> - Force execution of a command in a shell
3092
3093Like the above, but the command is passed to the shell. Again, we use
3094C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3095
3096=cut
3097
3098 # $sh command - start a shell and run a command in it.
e22ea7cc
RF
3099 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do {
3100
3101 # XXX: using csh or tcsh destroys sigint retvals!
3102 #&system($1); # use this instead
69893cff
RGS
3103
3104 # use the user's shell, or Bourne if none defined.
e22ea7cc
RF
3105 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 );
3106 next CMD;
3107 };
69893cff
RGS
3108
3109=head4 C<H> - display commands in history
3110
3111Prints the contents of C<@hist> (if any).
3112
3113=cut
3114
7fddc82f
RF
3115 $cmd =~ /^H\b\s*\*/ && do {
3116 @hist = @truehist = ();
3117 print $OUT "History cleansed\n";
3118 next CMD;
3119 };
e22ea7cc
RF
3120
3121 $cmd =~ /^H\b\s*(-(\d+))?/ && do {
3122
3123 # Anything other than negative numbers is ignored by
69893cff 3124 # the (incorrect) pattern, so this test does nothing.
e22ea7cc 3125 $end = $2 ? ( $#hist - $2 ) : 0;
69893cff
RGS
3126
3127 # Set to the minimum if less than zero.
e22ea7cc 3128 $hist = 0 if $hist < 0;
69893cff 3129
e22ea7cc 3130 # Start at the end of the array.
69893cff
RGS
3131 # Stay in while we're still above the ending value.
3132 # Tick back by one each time around the loop.
e22ea7cc 3133 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3134
3135 # Print the command unless it has no arguments.
e22ea7cc
RF
3136 print $OUT "$i: ", $hist[$i], "\n"
3137 unless $hist[$i] =~ /^.?$/;
3138 }
3139 next CMD;
3140 };
69893cff
RGS
3141
3142=head4 C<man, doc, perldoc> - look up documentation
3143
3144Just calls C<runman()> to print the appropriate document.
3145
3146=cut
3147
e22ea7cc
RF
3148 # man, perldoc, doc - show manual pages.
3149 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do {
3150 runman($1);
3151 next CMD;
3152 };
69893cff
RGS
3153
3154=head4 C<p> - print
3155
3156Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3157the bottom of the loop.
3158
3159=cut
3160
3161 # p - print (no args): print $_.
e22ea7cc 3162 $cmd =~ s/^p$/print {\$DB::OUT} \$_/;
69893cff
RGS
3163
3164 # p - print the given expression.
e22ea7cc 3165 $cmd =~ s/^p\b/print {\$DB::OUT} /;
69893cff
RGS
3166
3167=head4 C<=> - define command alias
3168
3169Manipulates C<%alias> to add or list command aliases.
3170
3171=cut
3172
e22ea7cc
RF
3173 # = - set up a command alias.
3174 $cmd =~ s/^=\s*// && do {
3175 my @keys;
3176 if ( length $cmd == 0 ) {
3177
69893cff 3178 # No args, get current aliases.
e22ea7cc
RF
3179 @keys = sort keys %alias;
3180 }
3181 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3182
69893cff
RGS
3183 # Creating a new alias. $k is alias name, $v is
3184 # alias value.
3185
e22ea7cc
RF
3186 # can't use $_ or kill //g state
3187 for my $x ( $k, $v ) {
3188
3189 # Escape "alarm" characters.
3190 $x =~ s/\a/\\a/g;
3191 }
69893cff
RGS
3192
3193 # Substitute key for value, using alarm chars
e22ea7cc 3194 # as separators (which is why we escaped them in
69893cff 3195 # the command).
e22ea7cc 3196 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3197
3198 # Turn off standard warn and die behavior.
e22ea7cc
RF
3199 local $SIG{__DIE__};
3200 local $SIG{__WARN__};
69893cff
RGS
3201
3202 # Is it valid Perl?
e22ea7cc
RF
3203 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3204
69893cff 3205 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3206 print $OUT "Can't alias $k to $v: $@\n";
3207 delete $alias{$k};
3208 next CMD;
3209 }
3210
69893cff 3211 # We'll only list the new one.
e22ea7cc 3212 @keys = ($k);
69893cff
RGS
3213 } ## end elsif (my ($k, $v) = ($cmd...
3214
3215 # The argument is the alias to list.
e22ea7cc
RF
3216 else {
3217 @keys = ($cmd);
3218 }
69893cff
RGS
3219
3220 # List aliases.
e22ea7cc
RF
3221 for my $k (@keys) {
3222
69893cff
RGS
3223 # Messy metaquoting: Trim the substiution code off.
3224 # We use control-G as the delimiter because it's not
3225 # likely to appear in the alias.
e22ea7cc
RF
3226 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3227
69893cff 3228 # Print the alias.
e22ea7cc
RF
3229 print $OUT "$k\t= $1\n";
3230 }
3231 elsif ( defined $alias{$k} ) {
3232
69893cff 3233 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3234 print $OUT "$k\t$alias{$k}\n";
3235 }
3236 else {
3237
69893cff 3238 # No such, dude.
e22ea7cc
RF
3239 print "No alias for $k\n";
3240 }
69893cff 3241 } ## end for my $k (@keys)
e22ea7cc
RF
3242 next CMD;
3243 };
69893cff
RGS
3244
3245=head4 C<source> - read commands from a file.
3246
3247Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3248pick it up.
3249
3250=cut
3251
e22ea7cc
RF
3252 # source - read commands from a file (or pipe!) and execute.
3253 $cmd =~ /^source\s+(.*\S)/ && do {
3254 if ( open my $fh, $1 ) {
3255
69893cff 3256 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3257 push @cmdfhs, $fh;
3258 }
3259 else {
3260
3261 # Couldn't open it.
3262 &warn("Can't execute `$1': $!\n");
3263 }
3264 next CMD;
3265 };
69893cff
RGS
3266
3267=head4 C<save> - send current history to a file
3268
3269Takes the complete history, (not the shrunken version you see with C<H>),
3270and saves it to the given filename, so it can be replayed using C<source>.
3271
3272Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3273
3274=cut
3275
3276 # save source - write commands to a file for later use
3277 $cmd =~ /^save\s*(.*)$/ && do {
e22ea7cc
RF
3278 my $file = $1 || '.perl5dbrc'; # default?
3279 if ( open my $fh, "> $file" ) {
3280
3281 # chomp to remove extraneous newlines from source'd files
3282 chomp( my @truelist =
3283 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3284 @truehist );
3285 print $fh join( "\n", @truelist );
69893cff 3286 print "commands saved in $file\n";
e22ea7cc
RF
3287 }
3288 else {
69893cff
RGS
3289 &warn("Can't save debugger commands in '$1': $!\n");
3290 }
3291 next CMD;
3292 };
3293
7fddc82f
RF
3294=head4 C<R> - restart
3295
3296Restart the debugger session.
3297
3298=head4 C<rerun> - rerun the current session
3299
3300Return to any given position in the B<true>-history list
3301
3302=cut
3303
3304 # R - restart execution.
3305 # rerun - controlled restart execution.
3306 $cmd =~ /^(R|rerun\s*(.*))$/ && do {
3307 my @args = ($1 eq 'R' ? restart() : rerun($2));
3308
ca28b541
AP
3309 # Close all non-system fds for a clean restart. A more
3310 # correct method would be to close all fds that were not
3311 # open when the process started, but this seems to be
3312 # hard. See "debugger 'R'estart and open database
3313 # connections" on p5p.
3314
47d3bbda 3315 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541
AP
3316 if (eval { require POSIX }) {
3317 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX());
3318 }
3319
3320 if (defined $max_fd) {
3321 foreach ($^F+1 .. $max_fd-1) {
3322 next unless open FD_TO_CLOSE, "<&=$_";
3323 close(FD_TO_CLOSE);
3324 }
3325 }
3326
7fddc82f
RF
3327 # And run Perl again. We use exec() to keep the
3328 # PID stable (and that way $ini_pids is still valid).
3329 exec(@args) || print $OUT "exec failed: $!\n";
3330
3331 last CMD;
3332 };
3333
69893cff
RGS
3334=head4 C<|, ||> - pipe output through the pager.
3335
be9a9b1d 3336For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3337(the program's standard output). For C<||>, we only save C<OUT>. We open a
3338pipe to the pager (restoring the output filehandles if this fails). If this
3339is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
3340set C<$signal>, sending us back into the debugger.
3341
3342We then trim off the pipe symbols and C<redo> the command loop at the
3343C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3344reading another.
3345
3346=cut
3347
3348 # || - run command in the pager, with output to DB::OUT.
e22ea7cc
RF
3349 $cmd =~ /^\|\|?\s*[^|]/ && do {
3350 if ( $pager =~ /^\|/ ) {
3351
69893cff 3352 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3353 open( SAVEOUT, ">&STDOUT" )
3354 || &warn("Can't save STDOUT");
3355 open( STDOUT, ">&OUT" )
3356 || &warn("Can't redirect STDOUT");
69893cff 3357 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3358 else {
3359
69893cff 3360 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3361 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3362 }
69893cff
RGS
3363
3364 # Fix up environment to record we have less if so.
e22ea7cc
RF
3365 fix_less();
3366
3367 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3368
69893cff 3369 # Couldn't open pipe to pager.
e22ea7cc
RF
3370 &warn("Can't pipe output to `$pager'");
3371 if ( $pager =~ /^\|/ ) {
3372
69893cff 3373 # Redirect I/O back again.
e22ea7cc
RF
3374 open( OUT, ">&STDOUT" ) # XXX: lost message
3375 || &warn("Can't restore DB::OUT");
3376 open( STDOUT, ">&SAVEOUT" )
3377 || &warn("Can't restore STDOUT");
3378 close(SAVEOUT);
69893cff 3379 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3380 else {
3381
69893cff 3382 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3383 open( OUT, ">&STDOUT" ) # XXX: lost message
3384 || &warn("Can't restore DB::OUT");
3385 }
3386 next CMD;
69893cff
RGS
3387 } ## end unless ($piped = open(OUT,...
3388
3389 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3390 $SIG{PIPE} = \&DB::catch
3391 if $pager =~ /^\|/
3392 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff
RGS
3393
3394 # Save current filehandle, unbuffer out, and put it back.
e22ea7cc
RF
3395 $selected = select(OUT);
3396 $| = 1;
69893cff
RGS
3397
3398 # Don't put it back if pager was a pipe.
e22ea7cc 3399 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3400
3401 # Trim off the pipe symbols and run the command now.
e22ea7cc
RF
3402 $cmd =~ s/^\|+\s*//;
3403 redo PIPE;
3404 };
69893cff
RGS
3405
3406=head3 END OF COMMAND PARSING
3407
3408Anything left in C<$cmd> at this point is a Perl expression that we want to
3409evaluate. We'll always evaluate in the user's context, and fully qualify
3410any variables we might want to address in the C<DB> package.
3411
3412=cut
3413
3414 # t - turn trace on.
e22ea7cc 3415 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
69893cff
RGS
3416
3417 # s - single-step. Remember the last command was 's'.
e22ea7cc 3418 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' };
69893cff
RGS
3419
3420 # n - single-step, but not into subs. Remember last command
e22ea7cc
RF
3421 # was 'n'.
3422 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' };
69893cff 3423
e22ea7cc 3424 } # PIPE:
69893cff 3425
e22ea7cc 3426 # Make sure the flag that says "the debugger's running" is
69893cff 3427 # still on, to make sure we get control again.
e22ea7cc 3428 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3429
3430 # Run *our* eval that executes in the caller's context.
e22ea7cc 3431 &eval;
69893cff
RGS
3432
3433 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3434 if ($onetimeDump) {
3435 $onetimeDump = undef;
69893cff 3436 $onetimedumpDepth = undef;
e22ea7cc
RF
3437 }
3438 elsif ( $term_pid == $$ ) {
c7e68384
IZ
3439 eval { # May run under miniperl, when not available...
3440 STDOUT->flush();
3441 STDERR->flush();
3442 };
e22ea7cc 3443
69893cff 3444 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3445 print $OUT "\n";
3446 }
3447 } ## end while (($term || &setterm...
69893cff
RGS
3448
3449=head3 POST-COMMAND PROCESSING
3450
3451After each command, we check to see if the command output was piped anywhere.
3452If so, we go through the necessary code to unhook the pipe and go back to
3453our standard filehandles for input and output.
3454
3455=cut
3456
e22ea7cc 3457 continue { # CMD:
69893cff
RGS
3458
3459 # At the end of every command:
e22ea7cc
RF
3460 if ($piped) {
3461
69893cff 3462 # Unhook the pipe mechanism now.
e22ea7cc
RF
3463 if ( $pager =~ /^\|/ ) {
3464
69893cff 3465 # No error from the child.
e22ea7cc 3466 $? = 0;
69893cff 3467
e22ea7cc
RF
3468 # we cannot warn here: the handle is missing --tchrist
3469 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3470
e22ea7cc 3471 # most of the $? crud was coping with broken cshisms
69893cff 3472 # $? is explicitly set to 0, so this never runs.
e22ea7cc
RF
3473 if ($?) {
3474 print SAVEOUT "Pager `$pager' failed: ";
3475 if ( $? == -1 ) {
3476 print SAVEOUT "shell returned -1\n";
3477 }
3478 elsif ( $? >> 8 ) {
3479 print SAVEOUT ( $? & 127 )
3480 ? " (SIG#" . ( $? & 127 ) . ")"
3481 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3482 }
3483 else {
3484 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3485 }
69893cff
RGS
3486 } ## end if ($?)
3487
e22ea7cc 3488 # Reopen filehandle for our output (if we can) and
69893cff 3489 # restore STDOUT (if we can).
e22ea7cc
RF
3490 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3491 open( STDOUT, ">&SAVEOUT" )
3492 || &warn("Can't restore STDOUT");
69893cff
RGS
3493
3494 # Turn off pipe exception handler if necessary.
e22ea7cc 3495 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3496
e22ea7cc
RF
3497 # Will stop ignoring SIGPIPE if done like nohup(1)
3498 # does SIGINT but Perl doesn't give us a choice.
69893cff 3499 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3500 else {
3501
69893cff 3502 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3503 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3504 }
69893cff
RGS
3505
3506 # Close filehandle pager was using, restore the normal one
3507 # if necessary,
3508 close(SAVEOUT);
e22ea7cc 3509 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3510
3511 # No pipes now.
e22ea7cc 3512 $piped = "";
69893cff 3513 } ## end if ($piped)
e22ea7cc 3514 } # CMD:
69893cff
RGS
3515
3516=head3 COMMAND LOOP TERMINATION
3517
3518When commands have finished executing, we come here. If the user closed the
3519input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3520evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3521C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3522The interpreter will then execute the next line and then return control to us
3523again.
3524
3525=cut
3526
3527 # No more commands? Quit.
e22ea7cc 3528 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF
69893cff
RGS
3529
3530 # Evaluate post-prompt commands.
e22ea7cc
RF
3531 foreach $evalarg (@$post) {
3532 &eval;
3533 }
3534 } # if ($single || $signal)
69893cff
RGS
3535
3536 # Put the user's globals back where you found them.
e22ea7cc 3537 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3538 ();
3539} ## end sub DB
3540
3541# The following code may be executed now:
3542# BEGIN {warn 4}
3543
3544=head2 sub
3545
3546C<sub> is called whenever a subroutine call happens in the program being
3547debugged. The variable C<$DB::sub> contains the name of the subroutine
3548being called.
3549
3550The core function of this subroutine is to actually call the sub in the proper
3551context, capturing its output. This of course causes C<DB::DB> to get called
3552again, repeating until the subroutine ends and returns control to C<DB::sub>
3553again. Once control returns, C<DB::sub> figures out whether or not to dump the
3554return value, and returns its captured copy of the return value as its own
3555return value. The value then feeds back into the program being debugged as if
3556C<DB::sub> hadn't been there at all.
3557
3558C<sub> does all the work of printing the subroutine entry and exit messages
3559enabled by setting C<$frame>. It notes what sub the autoloader got called for,
3560and also prints the return value if needed (for the C<r> command and if
3561the 16 bit is set in C<$frame>).
3562
3563It also tracks the subroutine call depth by saving the current setting of
3564C<$single> in the C<@stack> package global; if this exceeds the value in
3565C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3566setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3567of stop/don't stop on entry to subs set as it currently is set.
3568
3569=head3 C<caller()> support
3570
3571If C<caller()> is called from the package C<DB>, it provides some
3572additional data, in the following order:
3573
3574=over 4
3575
3576=item * C<$package>
3577
3578The package name the sub was in
3579
3580=item * C<$filename>
3581
3582The filename it was defined in
3583
3584=item * C<$line>
3585
3586The line number it was defined on
3587
3588=item * C<$subroutine>
3589
be9a9b1d 3590The subroutine name; C<(eval)> if an C<eval>().
69893cff
RGS
3591
3592=item * C<$hasargs>
3593
35941 if it has arguments, 0 if not
3595
3596=item * C<$wantarray>
3597
35981 if array context, 0 if scalar context
3599
3600=item * C<$evaltext>
3601
3602The C<eval>() text, if any (undefined for C<eval BLOCK>)
3603
3604=item * C<$is_require>
3605
3606frame was created by a C<use> or C<require> statement
3607
3608=item * C<$hints>
3609
3610pragma information; subject to change between versions
3611
3612=item * C<$bitmask>
3613
be9a9b1d 3614pragma information; subject to change between versions
69893cff
RGS
3615
3616=item * C<@DB::args>
3617
3618arguments with which the subroutine was invoked
3619
3620=back
3621
3622=cut
d338d6fe 3623
d12a4851 3624sub sub {
69893cff 3625
2cbb2ee1
RGS
3626 # lock ourselves under threads
3627 lock($DBGR);
3628
69893cff
RGS
3629 # Whether or not the autoloader was running, a scalar to put the
3630 # sub's return value in (if needed), and an array to put the sub's
3631 # return value in (if needed).
e22ea7cc 3632 my ( $al, $ret, @ret ) = "";
2cbb2ee1
RGS
3633 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) {
3634 print "creating new thread\n";
3635 }
69893cff
RGS
3636
3637 # If the last ten characters are C'::AUTOLOAD', note we've traced
3638 # into AUTOLOAD for $sub.
e22ea7cc
RF
3639 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) {
3640 $al = " for $$sub";
d12a4851 3641 }
69893cff
RGS
3642
3643 # We stack the stack pointer and then increment it to protect us
3644 # from a situation that might unwind a whole bunch of call frames
3645 # at once. Localizing the stack pointer means that it will automatically
3646 # unwind the same amount when multiple stack frames are unwound.
e22ea7cc 3647 local $stack_depth = $stack_depth + 1; # Protect from non-local exits
69893cff
RGS
3648
3649 # Expand @stack.
d12a4851 3650 $#stack = $stack_depth;
69893cff
RGS
3651
3652 # Save current single-step setting.
d12a4851 3653 $stack[-1] = $single;
69893cff 3654
e22ea7cc 3655 # Turn off all flags except single-stepping.
d12a4851 3656 $single &= 1;
69893cff
RGS
3657
3658 # If we've gotten really deeply recursed, turn on the flag that will
3659 # make us stop with the 'deep recursion' message.
d12a4851 3660 $single |= 4 if $stack_depth == $deep;
69893cff
RGS
3661
3662 # If frame messages are on ...
3663 (
3664 $frame & 4 # Extended frame entry message
e22ea7cc
RF
3665 ? (
3666 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ),
69893cff 3667
e22ea7cc 3668 # Why -1? But it works! :-(
69893cff
RGS
3669 # Because print_trace will call add 1 to it and then call
3670 # dump_trace; this results in our skipping -1+1 = 0 stack frames
3671 # in dump_trace.
e22ea7cc
RF
3672 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3673 )
3674 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" )
3675
69893cff 3676 # standard frame entry message
e22ea7cc
RF
3677 )
3678 if $frame;
69893cff
RGS
3679
3680 # Determine the sub's return type,and capture approppriately.
d12a4851 3681 if (wantarray) {
e22ea7cc 3682
69893cff
RGS
3683 # Called in array context. call sub and capture output.
3684 # DB::DB will recursively get control again if appropriate; we'll come
3685 # back here when the sub is finished.
d12a4851 3686 if ($assertion) {
e22ea7cc
RF
3687 $assertion = 0;
3688 eval { @ret = &$sub; };
3689 if ($@) {
3690 print $OUT $@;
3691 $signal = 1 unless $warnassertions;
3692 }
3693 }
3694 else {
69893cff 3695 @ret = &$sub;
69893cff 3696 }
69893cff
RGS
3697
3698 # Pop the single-step value back off the stack.
e22ea7cc 3699 $single |= $stack[ $stack_depth-- ];
69893cff
RGS
3700
3701 # Check for exit trace messages...
e22ea7cc
RF
3702 (
3703 $frame & 4 # Extended exit message
3704 ? (
3705 print_lineinfo( ' ' x $stack_depth, "out " ),
3706 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" )
3707 )
3708 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" )
3709
69893cff 3710 # Standard exit message
e22ea7cc
RF
3711 )
3712 if $frame & 2;