This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
perl5db.pl: ensure PadWalker is loaded from standard paths
[perl5.git] / lib / perl5db.pl
CommitLineData
e22ea7cc 1
b570d64b 2=head1 NAME
69893cff 3
be9a9b1d 4perl5db.pl - the perl debugger
69893cff
RGS
5
6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
69893cff
RGS
26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
69893cff
RGS
38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
69893cff
RGS
44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
69893cff
RGS
52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
69893cff
RGS
63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
69893cff
RGS
66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
69893cff
RGS
70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
69893cff
RGS
79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
69893cff
RGS
83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
69893cff
RGS
89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
69893cff
RGS
93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
69893cff
RGS
97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
69893cff
RGS
101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
69893cff
RGS
109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
69893cff
RGS
118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
69893cff
RGS
126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
69893cff
RGS
131it?
132
133=over 4
134
be9a9b1d 135=item *
69893cff 136
be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
69893cff
RGS
141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
69893cff
RGS
144works.
145
be9a9b1d
AT
146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
69893cff
RGS
149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
be9a9b1d
AT
153=item *
154
b570d64b
SF
155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
69893cff
RGS
158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
69893cff
RGS
166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
69893cff
RGS
172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
7e17a74c
JJ
176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
b570d64b
SF
182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
69893cff
RGS
187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
da052516 189The scalar C<${"_<$filename"}> simply contains the string C<$filename>.
be9a9b1d
AT
190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
ee59ac17 192like C<(eval 34)>.
69893cff
RGS
193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
69893cff
RGS
200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
69893cff
RGS
204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
69893cff
RGS
214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
69893cff
RGS
218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
69893cff
RGS
221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
69893cff
RGS
227ReadLine applications.
228
b570d64b 229=item * NonStop
69893cff
RGS
230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
69893cff
RGS
234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
69893cff
RGS
239
240host:port to connect to on remote host for remote debugging.
241
5561b870
AK
242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
69893cff
RGS
252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
69893cff
RGS
262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
69893cff
RGS
269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
69893cff
RGS
285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
69893cff
RGS
308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
69893cff
RGS
314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
69893cff
RGS
318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
7e3426ea 321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on.
69893cff
RGS
322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
69893cff
RGS
326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
b570d64b
SF
331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
69893cff
RGS
333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
69893cff
RGS
354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
69893cff
RGS
368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
be9a9b1d
AT
375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
69893cff
RGS
377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
69893cff
RGS
383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
69893cff
RGS
406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
69893cff
RGS
446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
69893cff
RGS
454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 476=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
69893cff
RGS
477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
69893cff
RGS
486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
b570d64b
SF
490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
69893cff
RGS
494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
69893cff
RGS
504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
a687059c
LW
511package DB;
512
6b24a4b7
SF
513use strict;
514
c59f1e04
SF
515use Cwd ();
516
517my $_initial_cwd;
518
2dbd01ad 519BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 520
e56c1e8d
SF
521BEGIN {
522 require feature;
523 $^V =~ /^v(\d+\.\d+)/;
524 feature->import(":$1");
c59f1e04 525 $_initial_cwd = Cwd::getcwd();
e56c1e8d
SF
526}
527
54d04a52 528# Debugger for Perl 5.00x; perl5db.pl patch level:
6b24a4b7
SF
529use vars qw($VERSION $header);
530
ee59ac17 531$VERSION = '1.49_04';
69893cff 532
e22ea7cc 533$header = "perl5db.pl version $VERSION";
d338d6fe 534
69893cff
RGS
535=head1 DEBUGGER ROUTINES
536
537=head2 C<DB::eval()>
538
539This function replaces straight C<eval()> inside the debugger; it simplifies
540the process of evaluating code in the user's context.
541
b570d64b 542The code to be evaluated is passed via the package global variable
69893cff
RGS
543C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
544
be9a9b1d
AT
545Before we do the C<eval()>, we preserve the current settings of C<$trace>,
546C<$single>, C<$^D> and C<$usercontext>. The latter contains the
547preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
548user's current package, grabbed when C<DB::DB> got control. This causes the
549proper context to be used when the eval is actually done. Afterward, we
550restore C<$trace>, C<$single>, and C<$^D>.
69893cff
RGS
551
552Next we need to handle C<$@> without getting confused. We save C<$@> in a
b570d64b
SF
553local lexical, localize C<$saved[0]> (which is where C<save()> will put
554C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 555C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
b570d64b
SF
556considered sane by the debugger. If there was an C<eval()> error, we print
557it on the debugger's output. If C<$onetimedump> is defined, we call
558C<dumpit> if it's set to 'dump', or C<methods> if it's set to
559'methods'. Setting it to something else causes the debugger to do the eval
560but not print the result - handy if you want to do something else with it
69893cff
RGS
561(the "watch expressions" code does this to get the value of the watch
562expression but not show it unless it matters).
563
b570d64b
SF
564In any case, we then return the list of output from C<eval> to the caller,
565and unwinding restores the former version of C<$@> in C<@saved> as well
69893cff
RGS
566(the localization of C<$saved[0]> goes away at the end of this scope).
567
568=head3 Parameters and variables influencing execution of DB::eval()
569
570C<DB::eval> isn't parameterized in the standard way; this is to keep the
571debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 572The variables listed below influence C<DB::eval()>'s execution directly.
69893cff
RGS
573
574=over 4
575
576=item C<$evalarg> - the thing to actually be eval'ed
577
be9a9b1d 578=item C<$trace> - Current state of execution tracing
69893cff 579
be9a9b1d 580=item C<$single> - Current state of single-stepping
69893cff 581
b570d64b 582=item C<$onetimeDump> - what is to be displayed after the evaluation
69893cff
RGS
583
584=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
585
586=back
587
588The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 589are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
590
591=over 4
592
593=item C<@res> - used to capture output from actual C<eval>.
594
595=item C<$otrace> - saved value of C<$trace>.
596
b570d64b 597=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
598
599=item C<$od> - saved value of C<$^D>.
600
601=item C<$saved[0]> - saved value of C<$@>.
602
b570d64b 603=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
604
605=back
606
607=head3 The problem of lexicals
608
609The context of C<DB::eval()> presents us with some problems. Obviously,
610we want to be 'sandboxed' away from the debugger's internals when we do
611the eval, but we need some way to control how punctuation variables and
b570d64b 612debugger globals are used.
69893cff
RGS
613
614We can't use local, because the code inside C<DB::eval> can see localized
615variables; and we can't use C<my> either for the same reason. The code
616in this routine compromises and uses C<my>.
617
618After this routine is over, we don't have user code executing in the debugger's
619context, so we can use C<my> freely.
620
621=cut
622
623############################################## Begin lexical danger zone
624
625# 'my' variables used here could leak into (that is, be visible in)
626# the context that the code being evaluated is executing in. This means that
627# the code could modify the debugger's variables.
628#
629# Fiddling with the debugger's context could be Bad. We insulate things as
630# much as we can.
631
6b24a4b7
SF
632use vars qw(
633 @args
634 %break_on_load
6b24a4b7
SF
635 $CommandSet
636 $CreateTTY
637 $DBGR
638 @dbline
639 $dbline
640 %dbline
641 $dieLevel
6b24a4b7 642 $filename
6b24a4b7
SF
643 $histfile
644 $histsize
6b24a4b7
SF
645 $IN
646 $inhibit_exit
647 @ini_INC
648 $ini_warn
6b24a4b7
SF
649 $maxtrace
650 $od
6b24a4b7
SF
651 @options
652 $osingle
653 $otrace
6b24a4b7
SF
654 $pager
655 $post
656 %postponed
657 $prc
658 $pre
659 $pretype
660 $psh
661 @RememberOnROptions
662 $remoteport
663 @res
664 $rl
665 @saved
6b24a4b7 666 $signalLevel
6b24a4b7 667 $sub
6b24a4b7 668 $term
6b24a4b7
SF
669 $usercontext
670 $warnLevel
6b24a4b7
SF
671);
672
0b83f3d9 673our (
2ef1dcdb 674 @cmdfhs,
0b83f3d9
SF
675 $evalarg,
676 $frame,
0664c09a 677 $hist,
0b83f3d9
SF
678 $ImmediateStop,
679 $line,
680 $onetimeDump,
b8d11fe0 681 $onetimedumpDepth,
1ce985d2 682 %option,
0b83f3d9 683 $OUT,
1ce985d2 684 $packname,
0b83f3d9
SF
685 $signal,
686 $single,
d1450c23 687 $start,
9d0b71b3
SF
688 %sub,
689 $subname,
0b83f3d9 690 $trace,
d1450c23 691 $window,
18b5b545 692);
931ac036 693
6b24a4b7
SF
694# Used to save @ARGV and extract any debugger-related flags.
695use vars qw(@ARGS);
696
697# Used to prevent multiple entries to diesignal()
698# (if for instance diesignal() itself dies)
699use vars qw($panic);
700
701# Used to prevent the debugger from running nonstop
702# after a restart
ebd0282e 703our ($second_time);
6b24a4b7
SF
704
705sub _calc_usercontext {
706 my ($package) = @_;
707
708 # Cancel strict completely for the evaluated code, so the code
709 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 710 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
711 . "package $package;"; # this won't let them modify, alas
712}
713
c1051fcf 714sub eval {
69893cff 715
c1051fcf 716 # 'my' would make it visible from user code
e22ea7cc 717 # but so does local! --tchrist
69893cff 718 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
719 local @res;
720 {
e22ea7cc
RF
721
722 # Try to keep the user code from messing with us. Save these so that
723 # even if the eval'ed code changes them, we can put them back again.
724 # Needed because the user could refer directly to the debugger's
69893cff
RGS
725 # package globals (and any 'my' variables in this containing scope)
726 # inside the eval(), and we want to try to stay safe.
e22ea7cc 727 local $otrace = $trace;
69893cff
RGS
728 local $osingle = $single;
729 local $od = $^D;
730
731 # Untaint the incoming eval() argument.
732 { ($evalarg) = $evalarg =~ /(.*)/s; }
733
e22ea7cc 734 # $usercontext built in DB::DB near the comment
69893cff
RGS
735 # "set up the context for DB::eval ..."
736 # Evaluate and save any results.
e22ea7cc 737 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
738
739 # Restore those old values.
740 $trace = $otrace;
741 $single = $osingle;
742 $^D = $od;
c1051fcf 743 }
69893cff
RGS
744
745 # Save the current value of $@, and preserve it in the debugger's copy
746 # of the saved precious globals.
c1051fcf 747 my $at = $@;
69893cff
RGS
748
749 # Since we're only saving $@, we only have to localize the array element
750 # that it will be stored in.
e22ea7cc 751 local $saved[0]; # Preserve the old value of $@
e3d167f6 752 eval { &DB::save };
69893cff
RGS
753
754 # Now see whether we need to report an error back to the user.
c1051fcf 755 if ($at) {
69893cff
RGS
756 local $\ = '';
757 print $OUT $at;
758 }
759
760 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
761 # are package globals.
762 elsif ($onetimeDump) {
e22ea7cc
RF
763 if ( $onetimeDump eq 'dump' ) {
764 local $option{dumpDepth} = $onetimedumpDepth
765 if defined $onetimedumpDepth;
766 dumpit( $OUT, \@res );
767 }
768 elsif ( $onetimeDump eq 'methods' ) {
769 methods( $res[0] );
770 }
69893cff 771 } ## end elsif ($onetimeDump)
c1051fcf 772 @res;
69893cff
RGS
773} ## end sub eval
774
775############################################## End lexical danger zone
c1051fcf 776
e22ea7cc
RF
777# After this point it is safe to introduce lexicals.
778# The code being debugged will be executing in its own context, and
69893cff 779# can't see the inside of the debugger.
d338d6fe 780#
e22ea7cc 781# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
782# possible. If you make something a lexical, it's not going to be addressable
783# from outside the debugger even if you know its name.
784
d338d6fe
PP
785# This file is automatically included if you do perl -d.
786# It's probably not useful to include this yourself.
787#
e22ea7cc 788# Before venturing further into these twisty passages, it is
2f7e9187
MS
789# wise to read the perldebguts man page or risk the ire of dragons.
790#
69893cff
RGS
791# (It should be noted that perldebguts will tell you a lot about
792# the underlying mechanics of how the debugger interfaces into the
793# Perl interpreter, but not a lot about the debugger itself. The new
794# comments in this code try to address this problem.)
795
d338d6fe 796# Note that no subroutine call is possible until &DB::sub is defined
36477c24 797# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 798# true if $deep is not defined.
055fd3a9
GS
799
800# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
801
802# modified Perl debugger, to be run from Emacs in perldb-mode
803# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
804# Johan Vromans -- upgrade to 4.0 pl 10
805# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 806########################################################################
d338d6fe 807
69893cff
RGS
808=head1 DEBUGGER INITIALIZATION
809
810The debugger starts up in phases.
811
812=head2 BASIC SETUP
813
814First, it initializes the environment it wants to run in: turning off
815warnings during its own compilation, defining variables which it will need
816to avoid warnings later, setting itself up to not exit when the program
817terminates, and defaulting to printing return values for the C<r> command.
818
819=cut
820
eda6e075 821# Needed for the statement after exec():
69893cff
RGS
822#
823# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 824# compilation. Probably it would be better practice to fix the warnings,
69893cff 825# but this is how it's done at the moment.
eda6e075 826
e22ea7cc
RF
827BEGIN {
828 $ini_warn = $^W;
829 $^W = 0;
830} # Switch compilation warnings off until another BEGIN.
d12a4851 831
69893cff
RGS
832local ($^W) = 0; # Switch run-time warnings off during init.
833
2cbb2ee1
RGS
834=head2 THREADS SUPPORT
835
836If we are running under a threaded Perl, we require threads and threads::shared
837if the environment variable C<PERL5DB_THREADED> is set, to enable proper
838threaded debugger control. C<-dt> can also be used to set this.
839
840Each new thread will be announced and the debugger prompt will always inform
841you of each new thread created. It will also indicate the thread id in which
842we are currently running within the prompt like this:
843
2dbd01ad 844 [tid] DB<$i>
2cbb2ee1
RGS
845
846Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
847command prompt. The prompt will show: C<[0]> when running under threads, but
848not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
849
850While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 851will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
852in a currently executing thread, you will stay there until it completes. With
853the current implementation it is not currently possible to hop from one thread
854to another.
855
856The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
857
858Note that threading support was built into the debugger as of Perl version
859C<5.8.6> and debugger version C<1.2.8>.
860
861=cut
862
863BEGIN {
2dbd01ad
SF
864 # ensure we can share our non-threaded variables or no-op
865 if ($ENV{PERL5DB_THREADED}) {
866 require threads;
867 require threads::shared;
868 import threads::shared qw(share);
869 $DBGR;
870 share(\$DBGR);
871 lock($DBGR);
872 print "Threads support enabled\n";
873 } else {
41ef2c66 874 *lock = sub(*) {};
cde405a6 875 *share = sub(\[$@%]) {};
2dbd01ad 876 }
2cbb2ee1
RGS
877}
878
2218c045
SF
879# These variables control the execution of 'dumpvar.pl'.
880{
881 package dumpvar;
882 use vars qw(
883 $hashDepth
884 $arrayDepth
885 $dumpDBFiles
886 $dumpPackages
887 $quoteHighBit
888 $printUndef
889 $globPrint
890 $usageOnly
891 );
892}
69893cff 893
2218c045
SF
894# used to control die() reporting in diesignal()
895{
896 package Carp;
897 use vars qw($CarpLevel);
898}
d338d6fe 899
422c59bf 900# without threads, $filename is not defined until DB::DB is called
cde405a6 901share($main::{'_<'.$filename}) if defined $filename;
2cbb2ee1 902
54d04a52 903# Command-line + PERLLIB:
69893cff 904# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
905@ini_INC = @INC;
906
69893cff
RGS
907# This was an attempt to clear out the previous values of various
908# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
909# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
910
69893cff
RGS
911# We set these variables to safe values. We don't want to blindly turn
912# off warnings, because other packages may still want them.
e22ea7cc
RF
913$trace = $signal = $single = 0; # Uninitialized warning suppression
914 # (local $^W cannot help - other packages!).
69893cff
RGS
915
916# Default to not exiting when program finishes; print the return
917# value when the 'r' command is used to return from a subroutine.
55497cff 918$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 919
6b24a4b7
SF
920use vars qw($trace_to_depth);
921
5e2b42dd
SF
922# Default to 1E9 so it won't be limited to a certain recursion depth.
923$trace_to_depth = 1E9;
bdba49ad 924
69893cff
RGS
925=head1 OPTION PROCESSING
926
b570d64b
SF
927The debugger's options are actually spread out over the debugger itself and
928C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
929subs to be called with a value. To try to make this a little easier to
930manage, the debugger uses a few data structures to define what options
931are legal and how they are to be processed.
932
933First, the C<@options> array defines the I<names> of all the options that
934are to be accepted.
935
936=cut
937
938@options = qw(
5561b870 939 CommandSet HistFile HistSize
e22ea7cc
RF
940 hashDepth arrayDepth dumpDepth
941 DumpDBFiles DumpPackages DumpReused
942 compactDump veryCompact quote
943 HighBit undefPrint globPrint
944 PrintRet UsageOnly frame
945 AutoTrace TTY noTTY
946 ReadLine NonStop LineInfo
947 maxTraceLen recallCommand ShellBang
948 pager tkRunning ornaments
949 signalLevel warnLevel dieLevel
950 inhibit_exit ImmediateStop bareStringify
951 CreateTTY RemotePort windowSize
584420f0 952 DollarCaretP
e22ea7cc 953);
d12a4851 954
584420f0 955@RememberOnROptions = qw(DollarCaretP);
d12a4851 956
69893cff
RGS
957=pod
958
959Second, C<optionVars> lists the variables that each option uses to save its
960state.
961
962=cut
963
6b24a4b7
SF
964use vars qw(%optionVars);
965
69893cff 966%optionVars = (
e22ea7cc
RF
967 hashDepth => \$dumpvar::hashDepth,
968 arrayDepth => \$dumpvar::arrayDepth,
969 CommandSet => \$CommandSet,
970 DumpDBFiles => \$dumpvar::dumpDBFiles,
971 DumpPackages => \$dumpvar::dumpPackages,
972 DumpReused => \$dumpvar::dumpReused,
973 HighBit => \$dumpvar::quoteHighBit,
974 undefPrint => \$dumpvar::printUndef,
975 globPrint => \$dumpvar::globPrint,
976 UsageOnly => \$dumpvar::usageOnly,
977 CreateTTY => \$CreateTTY,
978 bareStringify => \$dumpvar::bareStringify,
979 frame => \$frame,
980 AutoTrace => \$trace,
981 inhibit_exit => \$inhibit_exit,
982 maxTraceLen => \$maxtrace,
983 ImmediateStop => \$ImmediateStop,
984 RemotePort => \$remoteport,
985 windowSize => \$window,
5561b870
AK
986 HistFile => \$histfile,
987 HistSize => \$histsize,
69893cff
RGS
988);
989
990=pod
991
992Third, C<%optionAction> defines the subroutine to be called to process each
993option.
994
b570d64b 995=cut
69893cff 996
6b24a4b7
SF
997use vars qw(%optionAction);
998
69893cff
RGS
999%optionAction = (
1000 compactDump => \&dumpvar::compactDump,
1001 veryCompact => \&dumpvar::veryCompact,
1002 quote => \&dumpvar::quote,
1003 TTY => \&TTY,
1004 noTTY => \&noTTY,
1005 ReadLine => \&ReadLine,
1006 NonStop => \&NonStop,
1007 LineInfo => \&LineInfo,
1008 recallCommand => \&recallCommand,
1009 ShellBang => \&shellBang,
1010 pager => \&pager,
1011 signalLevel => \&signalLevel,
1012 warnLevel => \&warnLevel,
1013 dieLevel => \&dieLevel,
1014 tkRunning => \&tkRunning,
1015 ornaments => \&ornaments,
1016 RemotePort => \&RemotePort,
1017 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1018);
1019
69893cff
RGS
1020=pod
1021
1022Last, the C<%optionRequire> notes modules that must be C<require>d if an
1023option is used.
1024
1025=cut
d338d6fe 1026
69893cff
RGS
1027# Note that this list is not complete: several options not listed here
1028# actually require that dumpvar.pl be loaded for them to work, but are
1029# not in the table. A subsequent patch will correct this problem; for
1030# the moment, we're just recommenting, and we are NOT going to change
1031# function.
6b24a4b7
SF
1032use vars qw(%optionRequire);
1033
eda6e075 1034%optionRequire = (
69893cff
RGS
1035 compactDump => 'dumpvar.pl',
1036 veryCompact => 'dumpvar.pl',
1037 quote => 'dumpvar.pl',
e22ea7cc 1038);
69893cff
RGS
1039
1040=pod
1041
1042There are a number of initialization-related variables which can be set
1043by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1044variable. These are:
1045
1046=over 4
1047
1048=item C<$rl> - readline control XXX needs more explanation
1049
1050=item C<$warnLevel> - whether or not debugger takes over warning handling
1051
1052=item C<$dieLevel> - whether or not debugger takes over die handling
1053
1054=item C<$signalLevel> - whether or not debugger takes over signal handling
1055
1056=item C<$pre> - preprompt actions (array reference)
1057
1058=item C<$post> - postprompt actions (array reference)
1059
1060=item C<$pretype>
1061
1062=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1063
1064=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1065
1066=back
1067
1068=cut
d338d6fe
PP
1069
1070# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1071$rl = 1 unless defined $rl;
1072$warnLevel = 1 unless defined $warnLevel;
1073$dieLevel = 1 unless defined $dieLevel;
1074$signalLevel = 1 unless defined $signalLevel;
1075$pre = [] unless defined $pre;
1076$post = [] unless defined $post;
1077$pretype = [] unless defined $pretype;
1078$CreateTTY = 3 unless defined $CreateTTY;
1079$CommandSet = '580' unless defined $CommandSet;
1080
2cbb2ee1
RGS
1081share($rl);
1082share($warnLevel);
1083share($dieLevel);
1084share($signalLevel);
1085share($pre);
1086share($post);
1087share($pretype);
1088share($rl);
1089share($CreateTTY);
1090share($CommandSet);
1091
69893cff
RGS
1092=pod
1093
1094The default C<die>, C<warn>, and C<signal> handlers are set up.
1095
1096=cut
055fd3a9 1097
d338d6fe
PP
1098warnLevel($warnLevel);
1099dieLevel($dieLevel);
1100signalLevel($signalLevel);
055fd3a9 1101
69893cff
RGS
1102=pod
1103
1104The pager to be used is needed next. We try to get it from the
5561b870 1105environment first. If it's not defined there, we try to find it in
69893cff
RGS
1106the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1107then call the C<pager()> function to save the pager name.
1108
1109=cut
1110
1111# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1112pager(
e22ea7cc 1113
69893cff 1114 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1115 defined $ENV{PAGER}
1116 ? $ENV{PAGER}
69893cff
RGS
1117
1118 # If not, see if Config.pm defines it.
e22ea7cc
RF
1119 : eval { require Config }
1120 && defined $Config::Config{pager}
1121 ? $Config::Config{pager}
69893cff
RGS
1122
1123 # If not, fall back to 'more'.
e22ea7cc
RF
1124 : 'more'
1125 )
1126 unless defined $pager;
69893cff
RGS
1127
1128=pod
1129
1130We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1131recall character (C<!> unless otherwise defined) and the shell escape
1132character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1133neither works in the debugger at the moment.
1134
1135=cut
1136
055fd3a9 1137setman();
69893cff
RGS
1138
1139# Set up defaults for command recall and shell escape (note:
1140# these currently don't work in linemode debugging).
2218c045
SF
1141recallCommand("!") unless defined $prc;
1142shellBang("!") unless defined $psh;
69893cff
RGS
1143
1144=pod
1145
1146We then set up the gigantic string containing the debugger help.
1147We also set the limit on the number of arguments we'll display during a
1148trace.
1149
1150=cut
1151
04e43a21 1152sethelp();
69893cff
RGS
1153
1154# If we didn't get a default for the length of eval/stack trace args,
1155# set it here.
1d06cb2d 1156$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1157
1158=head2 SETTING UP THE DEBUGGER GREETING
1159
be9a9b1d 1160The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1161running, and whether the current debugger is the primary or a child.
1162
1163If we are the primary, we just hang onto our pid so we'll have it when
1164or if we start a child debugger. If we are a child, we'll set things up
1165so we'll have a unique greeting and so the parent will give us our own
1166TTY later.
1167
1168We save the current contents of the C<PERLDB_PIDS> environment variable
1169because we mess around with it. We'll also need to hang onto it because
1170we'll need it if we restart.
1171
1172Child debuggers make a label out of the current PID structure recorded in
1173PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1174yet so the parent will give them one later via C<resetterm()>.
1175
1176=cut
1177
e22ea7cc 1178# Save the current contents of the environment; we're about to
69893cff 1179# much with it. We'll need this if we have to restart.
6b24a4b7 1180use vars qw($ini_pids);
f1583d8f 1181$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1182
6b24a4b7
SF
1183use vars qw ($pids $term_pid);
1184
e22ea7cc
RF
1185if ( defined $ENV{PERLDB_PIDS} ) {
1186
69893cff 1187 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1188 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1189 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1190
1191 my $env_pids = $ENV{PERLDB_PIDS};
1192 $pids = "[$env_pids]";
1193
1194 # Unless we are on OpenVMS, all programs under the DCL shell run under
1195 # the same PID.
1196
1197 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1198 $term_pid = $$;
1199 }
1200 else {
1201 $ENV{PERLDB_PIDS} .= "->$$";
1202 $term_pid = -1;
1203 }
1204
69893cff
RGS
1205} ## end if (defined $ENV{PERLDB_PIDS...
1206else {
e22ea7cc
RF
1207
1208 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1209 # child debugger, and mark us as the parent, so we'll know to set up
1210 # more TTY's is we have to.
1211 $ENV{PERLDB_PIDS} = "$$";
619a0444 1212 $pids = "[pid=$$]";
e22ea7cc 1213 $term_pid = $$;
f1583d8f 1214}
69893cff 1215
6b24a4b7 1216use vars qw($pidprompt);
f1583d8f 1217$pidprompt = '';
69893cff
RGS
1218
1219# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1220our ($slave_editor);
69893cff
RGS
1221*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1222
1223=head2 READING THE RC FILE
1224
b570d64b 1225The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1226running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1227
b570d64b 1228=cut
69893cff
RGS
1229
1230# As noted, this test really doesn't check accurately that the debugger
1231# is running at a terminal or not.
d338d6fe 1232
6b24a4b7 1233use vars qw($rcfile);
fb4d8a6c
SF
1234{
1235 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1236 # this is the wrong metric!
1237 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1238}
1239
69893cff
RGS
1240=pod
1241
1242The debugger does a safety test of the file to be read. It must be owned
1243either by the current user or root, and must only be writable by the owner.
1244
1245=cut
1246
1247# This wraps a safety test around "do" to read and evaluate the init file.
1248#
055fd3a9
GS
1249# This isn't really safe, because there's a race
1250# between checking and opening. The solution is to
1251# open and fstat the handle, but then you have to read and
1252# eval the contents. But then the silly thing gets
69893cff
RGS
1253# your lexical scope, which is unfortunate at best.
1254sub safe_do {
055fd3a9
GS
1255 my $file = shift;
1256
1257 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1258 local $SIG{__WARN__};
1259 local $SIG{__DIE__};
055fd3a9 1260
e22ea7cc 1261 unless ( is_safe_file($file) ) {
69893cff 1262 CORE::warn <<EO_GRIPE;
055fd3a9 1263perldb: Must not source insecure rcfile $file.
b570d64b 1264 You or the superuser must be the owner, and it must not
69893cff 1265 be writable by anyone but its owner.
055fd3a9 1266EO_GRIPE
69893cff
RGS
1267 return;
1268 } ## end unless (is_safe_file($file...
055fd3a9
GS
1269
1270 do $file;
1271 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1272} ## end sub safe_do
055fd3a9 1273
69893cff
RGS
1274# This is the safety test itself.
1275#
055fd3a9
GS
1276# Verifies that owner is either real user or superuser and that no
1277# one but owner may write to it. This function is of limited use
1278# when called on a path instead of upon a handle, because there are
1279# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1280# eventually accessed is the same as the one tested.
055fd3a9
GS
1281# Assumes that the file's existence is not in doubt.
1282sub is_safe_file {
1283 my $path = shift;
69893cff 1284 stat($path) || return; # mysteriously vaporized
e22ea7cc 1285 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1286
1287 return 0 if $uid != 0 && $uid != $<;
1288 return 0 if $mode & 022;
1289 return 1;
69893cff 1290} ## end sub is_safe_file
055fd3a9 1291
69893cff 1292# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1293# exists, we safely do it.
1294if ( -f $rcfile ) {
055fd3a9 1295 safe_do("./$rcfile");
69893cff 1296}
e22ea7cc 1297
69893cff 1298# If there isn't one here, try the user's home directory.
e22ea7cc 1299elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1300 safe_do("$ENV{HOME}/$rcfile");
1301}
e22ea7cc 1302
69893cff 1303# Else try the login directory.
e22ea7cc 1304elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1305 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1306}
1307
69893cff 1308# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1309if ( defined $ENV{PERLDB_OPTS} ) {
1310 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1311}
1312
69893cff
RGS
1313=pod
1314
1315The last thing we do during initialization is determine which subroutine is
1316to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1317the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1318(darwin).
69893cff
RGS
1319
1320=cut
1321
1322# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1323# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1324# OS/2, or on Mac OS X. This may need some expansion.
1325
1326if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1327{
b570d64b 1328 if ( defined $remoteport ) {
11653f7f
JJ
1329 # Expect an inetd-like server
1330 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1331 }
1332 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1333 # of terminal this is,
1334 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1335 and defined $ENV{DISPLAY} # and what display it's on,
1336 )
1337 {
1338 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1339 }
babb663a
RH
1340 elsif ( $ENV{TMUX} ) {
1341 *get_fork_TTY = \&tmux_get_fork_TTY;
1342 }
6fae1ad7
RF
1343 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1344 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1345 }
1346 elsif ( $^O eq 'darwin' # If this is Mac OS X
1347 and defined $ENV{TERM_PROGRAM} # and we're running inside
1348 and $ENV{TERM_PROGRAM}
1349 eq 'Apple_Terminal' # Terminal.app
1350 )
1351 {
1352 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1353 }
69893cff 1354} ## end if (not defined &get_fork_TTY...
e22ea7cc 1355
dbb46cec
DQ
1356# untaint $^O, which may have been tainted by the last statement.
1357# see bug [perl #24674]
e22ea7cc
RF
1358$^O =~ m/^(.*)\z/;
1359$^O = $1;
f1583d8f 1360
d12a4851 1361# Here begin the unreadable code. It needs fixing.
055fd3a9 1362
69893cff
RGS
1363=head2 RESTART PROCESSING
1364
1365This section handles the restart command. When the C<R> command is invoked, it
1366tries to capture all of the state it can into environment variables, and
1367then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1368if C<PERLDB_RESTART> is there; if so, we reload all the information that
1369the R command stuffed into the environment variables.
1370
b570d64b 1371 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1372 PERLDB_HIST - command history, if it's available
1373 PERLDB_ON_LOAD - breakpoints set by the rc file
555bd962
BG
1374 PERLDB_POSTPONE - subs that have been loaded/not executed,
1375 and have actions
69893cff
RGS
1376 PERLDB_VISITED - files that had breakpoints
1377 PERLDB_FILE_... - breakpoints for a file
1378 PERLDB_OPT - active options
1379 PERLDB_INC - the original @INC
1380 PERLDB_PRETYPE - preprompt debugger actions
1381 PERLDB_PRE - preprompt Perl code
1382 PERLDB_POST - post-prompt Perl code
1383 PERLDB_TYPEAHEAD - typeahead captured by readline()
1384
1385We chug through all these variables and plug the values saved in them
1386back into the appropriate spots in the debugger.
1387
1388=cut
1389
0664c09a 1390use vars qw(%postponed_file @typeahead);
14f38b27 1391
0664c09a 1392our (@hist, @truehist);
6b24a4b7 1393
fb0fb5f4
SF
1394sub _restore_shared_globals_after_restart
1395{
1396 @hist = get_list('PERLDB_HIST');
1397 %break_on_load = get_list("PERLDB_ON_LOAD");
1398 %postponed = get_list("PERLDB_POSTPONE");
1399
1400 share(@hist);
1401 share(@truehist);
1402 share(%break_on_load);
1403 share(%postponed);
1404}
1405
e18a02a6 1406sub _restore_breakpoints_and_actions {
e22ea7cc 1407
e22ea7cc 1408 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1409
bdba49ad
SF
1410 for my $file_idx ( 0 .. $#had_breakpoints ) {
1411 my $filename = $had_breakpoints[$file_idx];
1412 my %pf = get_list("PERLDB_FILE_$file_idx");
1413 $postponed_file{ $filename } = \%pf if %pf;
1414 my @lines = sort {$a <=> $b} keys(%pf);
1415 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1416 for my $line_idx (0 .. $#lines) {
1417 _set_breakpoint_enabled_status(
1418 $filename,
1419 $lines[$line_idx],
1420 ($enabled_statuses[$line_idx] ? 1 : ''),
1421 );
1422 }
e22ea7cc 1423 }
69893cff 1424
e18a02a6
SF
1425 return;
1426}
1427
ca50076b
SF
1428sub _restore_options_after_restart
1429{
1430 my %options_map = get_list("PERLDB_OPT");
1431
1432 while ( my ( $opt, $val ) = each %options_map ) {
1433 $val =~ s/[\\\']/\\$1/g;
1434 parse_options("$opt'$val'");
1435 }
1436
1437 return;
1438}
1439
18580168
SF
1440sub _restore_globals_after_restart
1441{
1442 # restore original @INC
1443 @INC = get_list("PERLDB_INC");
1444 @ini_INC = @INC;
1445
1446 # return pre/postprompt actions and typeahead buffer
1447 $pretype = [ get_list("PERLDB_PRETYPE") ];
1448 $pre = [ get_list("PERLDB_PRE") ];
1449 $post = [ get_list("PERLDB_POST") ];
1450 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1451
1452 return;
1453}
1454
fb0fb5f4 1455
e18a02a6
SF
1456if ( exists $ENV{PERLDB_RESTART} ) {
1457
1458 # We're restarting, so we don't need the flag that says to restart anymore.
1459 delete $ENV{PERLDB_RESTART};
1460
1461 # $restart = 1;
fb0fb5f4 1462 _restore_shared_globals_after_restart();
e18a02a6
SF
1463
1464 _restore_breakpoints_and_actions();
1465
69893cff 1466 # restore options
ca50076b 1467 _restore_options_after_restart();
69893cff 1468
18580168 1469 _restore_globals_after_restart();
69893cff
RGS
1470} ## end if (exists $ENV{PERLDB_RESTART...
1471
1472=head2 SETTING UP THE TERMINAL
1473
1474Now, we'll decide how the debugger is going to interact with the user.
1475If there's no TTY, we set the debugger to run non-stop; there's not going
1476to be anyone there to enter commands.
1477
1478=cut
54d04a52 1479
ebd0282e 1480use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1481use vars qw($lineinfo $doccmd);
1482
ebd0282e
SF
1483our ($runnonstop);
1484
e0047406
KF
1485# Local autoflush to avoid rt#116769,
1486# as calling IO::File methods causes an unresolvable loop
1487# that results in debugger failure.
1488sub _autoflush {
1489 my $o = select($_[0]);
1490 $|++;
1491 select($o);
1492}
1493
d338d6fe 1494if ($notty) {
69893cff 1495 $runnonstop = 1;
2dbd01ad 1496 share($runnonstop);
69893cff 1497}
d12a4851 1498
69893cff
RGS
1499=pod
1500
1501If there is a TTY, we have to determine who it belongs to before we can
1502proceed. If this is a slave editor or graphical debugger (denoted by
1503the first command-line switch being '-emacs'), we shift this off and
1504set C<$rl> to 0 (XXX ostensibly to do straight reads).
1505
1506=cut
1507
1508else {
e22ea7cc 1509
69893cff
RGS
1510 # Is Perl being run from a slave editor or graphical debugger?
1511 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1512 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1513 $rl = 0;
1514 shift(@main::ARGV);
1515 }
e22ea7cc
RF
1516
1517 #require Term::ReadLine;
d12a4851 1518
69893cff
RGS
1519=pod
1520
1521We then determine what the console should be on various systems:
1522
1523=over 4
1524
1525=item * Cygwin - We use C<stdin> instead of a separate device.
1526
1527=cut
1528
e22ea7cc
RF
1529 if ( $^O eq 'cygwin' ) {
1530
69893cff
RGS
1531 # /dev/tty is binary. use stdin for textmode
1532 undef $console;
1533 }
1534
f703fc96 1535=item * Unix - use F</dev/tty>.
69893cff
RGS
1536
1537=cut
1538
e22ea7cc 1539 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1540 $console = "/dev/tty";
1541 }
1542
1543=item * Windows or MSDOS - use C<con>.
1544
1545=cut
1546
e22ea7cc 1547 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1548 $console = "con";
1549 }
1550
cf412c92
AB
1551=item * AmigaOS - use C<CONSOLE:>.
1552
1553=cut
1554
1555 elsif ( $^O eq 'amigaos' ) {
1556 $console = "CONSOLE:";
1557 }
1558
69893cff
RGS
1559=item * VMS - use C<sys$command>.
1560
1561=cut
1562
c9cc5940
JH
1563 elsif ($^O eq 'VMS') {
1564 $console = 'sys$command';
1565 }
1566
1567# Keep this last.
e22ea7cc 1568
c9cc5940
JH
1569 else {
1570 _db_warn("Can't figure out your console, using stdin");
1571 undef $console;
d12a4851 1572 }
69893cff
RGS
1573
1574=pod
1575
1576=back
1577
1578Several other systems don't use a specific console. We C<undef $console>
1579for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
739a0b84 1580with a slave editor).
69893cff
RGS
1581
1582=cut
d12a4851 1583
e22ea7cc
RF
1584 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1585
69893cff 1586 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1587 $console = undef;
1588 }
1589
1590 if ( $^O eq 'NetWare' ) {
d12a4851 1591
69893cff
RGS
1592 # /dev/tty is binary. use stdin for textmode
1593 $console = undef;
1594 }
d12a4851 1595
69893cff
RGS
1596 # In OS/2, we need to use STDIN to get textmode too, even though
1597 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1598 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1599 { # In OS/2
1600 $console = undef;
1601 }
1602
69893cff
RGS
1603=pod
1604
1605If there is a TTY hanging around from a parent, we use that as the console.
1606
1607=cut
1608
e22ea7cc 1609 $console = $tty if defined $tty;
d12a4851 1610
b570d64b 1611=head2 SOCKET HANDLING
69893cff
RGS
1612
1613The debugger is capable of opening a socket and carrying out a debugging
1614session over the socket.
1615
1616If C<RemotePort> was defined in the options, the debugger assumes that it
1617should try to start a debugging session on that port. It builds the socket
1618and then tries to connect the input and output filehandles to it.
1619
1620=cut
1621
1622 # Handle socket stuff.
e22ea7cc
RF
1623
1624 if ( defined $remoteport ) {
1625
69893cff
RGS
1626 # If RemotePort was defined in the options, connect input and output
1627 # to the socket.
11653f7f 1628 $IN = $OUT = connect_remoteport();
69893cff
RGS
1629 } ## end if (defined $remoteport)
1630
1631=pod
1632
1633If no C<RemotePort> was defined, and we want to create a TTY on startup,
1634this is probably a situation where multiple debuggers are running (for example,
1635a backticked command that starts up another debugger). We create a new IN and
1636OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1637and if we can.
1638
1639=cut
1640
1641 # Non-socket.
1642 else {
e22ea7cc 1643
69893cff
RGS
1644 # Two debuggers running (probably a system or a backtick that invokes
1645 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1646 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1647 # know how, and we can.
e22ea7cc
RF
1648 create_IN_OUT(4) if $CreateTTY & 4;
1649 if ($console) {
1650
69893cff 1651 # If we have a console, check to see if there are separate ins and
cd1191f1 1652 # outs to open. (They are assumed identical if not.)
69893cff 1653
e22ea7cc
RF
1654 my ( $i, $o ) = split /,/, $console;
1655 $o = $i unless defined $o;
69893cff 1656
69893cff 1657 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1658 open( IN, "+<$i" )
1659 || open( IN, "<$i" )
1660 || open( IN, "<&STDIN" );
1661
69893cff
RGS
1662 # read/write/create/clobber out, or write/create/clobber out,
1663 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1664 open( OUT, "+>$o" )
1665 || open( OUT, ">$o" )
1666 || open( OUT, ">&STDERR" )
1667 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1668
1669 } ## end if ($console)
1670 elsif ( not defined $console ) {
1671
1672 # No console. Open STDIN.
1673 open( IN, "<&STDIN" );
1674
1675 # merge with STDERR, or with STDOUT.
1676 open( OUT, ">&STDERR" )
1677 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1678 $console = 'STDIN/OUT';
69893cff
RGS
1679 } ## end elsif (not defined $console)
1680
1681 # Keep copies of the filehandles so that when the pager runs, it
1682 # can close standard input without clobbering ours.
2b0b9dd1
SF
1683 if ($console or (not defined($console))) {
1684 $IN = \*IN;
1685 $OUT = \*OUT;
1686 }
e22ea7cc
RF
1687 } ## end elsif (from if(defined $remoteport))
1688
1689 # Unbuffer DB::OUT. We need to see responses right away.
e0047406 1690 _autoflush($OUT);
e22ea7cc
RF
1691
1692 # Line info goes to debugger output unless pointed elsewhere.
1693 # Pointing elsewhere makes it possible for slave editors to
1694 # keep track of file and position. We have both a filehandle
1695 # and a I/O description to keep track of.
1696 $LINEINFO = $OUT unless defined $LINEINFO;
1697 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1698 # share($LINEINFO); # <- unable to share globs
1699 share($lineinfo); #
e22ea7cc 1700
69893cff
RGS
1701=pod
1702
1703To finish initialization, we show the debugger greeting,
1704and then call the C<afterinit()> subroutine if there is one.
1705
1706=cut
d12a4851 1707
e22ea7cc
RF
1708 # Show the debugger greeting.
1709 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1710 unless ($runnonstop) {
1711 local $\ = '';
1712 local $, = '';
1713 if ( $term_pid eq '-1' ) {
1714 print $OUT "\nDaughter DB session started...\n";
1715 }
1716 else {
1717 print $OUT "\nLoading DB routines from $header\n";
1718 print $OUT (
1719 "Editor support ",
1720 $slave_editor ? "enabled" : "available", ".\n"
1721 );
1722 print $OUT
1f874cb6 1723"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1724 } ## end else [ if ($term_pid eq '-1')
1725 } ## end unless ($runnonstop)
1726} ## end else [ if ($notty)
1727
1728# XXX This looks like a bug to me.
1729# Why copy to @ARGS and then futz with @args?
d338d6fe 1730@ARGS = @ARGV;
6b24a4b7 1731# for (@args) {
69893cff
RGS
1732 # Make sure backslashes before single quotes are stripped out, and
1733 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1734 # s/\'/\\\'/g; # removed while not justified understandably
1735 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1736# }
d338d6fe 1737
e22ea7cc 1738# If there was an afterinit() sub defined, call it. It will get
69893cff 1739# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1740if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1741 afterinit();
d338d6fe 1742}
e22ea7cc 1743
69893cff 1744# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1745use vars qw($I_m_init);
1746
43aed9ee
IZ
1747$I_m_init = 1;
1748
d338d6fe
PP
1749############################################################ Subroutines
1750
69893cff
RGS
1751=head1 SUBROUTINES
1752
1753=head2 DB
1754
1755This gigantic subroutine is the heart of the debugger. Called before every
1756statement, its job is to determine if a breakpoint has been reached, and
1757stop if so; read commands from the user, parse them, and execute
b468dcb6 1758them, and then send execution off to the next statement.
69893cff
RGS
1759
1760Note that the order in which the commands are processed is very important;
1761some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1762to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1763but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1764see what's happening in any given command.
1765
1766=cut
1767
136ae23d
SF
1768# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1769
6b24a4b7
SF
1770use vars qw(
1771 $action
6b24a4b7 1772 $cmd
6b24a4b7
SF
1773 $file
1774 $filename_ini
1775 $finished
1776 %had_breakpoints
6b24a4b7
SF
1777 $level
1778 $max
6b24a4b7 1779 $package
6b24a4b7
SF
1780 $try
1781);
1782
1ce985d2 1783our (
bdb3f37d 1784 %alias,
1ce985d2 1785 $doret,
0664c09a 1786 $end,
4d0e1f38 1787 $fall_off_end,
d1450c23 1788 $incr,
73c5e526 1789 $laststep,
14f38b27 1790 $rc,
ddf4cf26 1791 $sh,
1ce985d2
SF
1792 $stack_depth,
1793 @stack,
1794 @to_watch,
1795 @old_watch,
1796);
8ad70697 1797
6791e41b
SF
1798sub _DB__determine_if_we_should_break
1799{
1800 # if we have something here, see if we should break.
1801 # $stop is lexical and local to this block - $action on the other hand
1802 # is global.
1803 my $stop;
1804
1805 if ( $dbline{$line}
1806 && _is_breakpoint_enabled($filename, $line)
1807 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1808 {
1809
1810 # Stop if the stop criterion says to just stop.
1811 if ( $stop eq '1' ) {
1812 $signal |= 1;
1813 }
1814
1815 # It's a conditional stop; eval it in the user's context and
1816 # see if we should stop. If so, remove the one-time sigil.
1817 elsif ($stop) {
1818 $evalarg = "\$DB::signal |= 1 if do {$stop}";
e0cd3692
SF
1819 # The &-call is here to ascertain the mutability of @_.
1820 &DB::eval;
6791e41b
SF
1821 # If the breakpoint is temporary, then delete its enabled status.
1822 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1823 _cancel_breakpoint_temp_enabled_status($filename, $line);
1824 }
1825 }
1826 } ## end if ($dbline{$line} && ...
1827}
1828
8481f647
SF
1829sub _DB__is_finished {
1830 if ($finished and $level <= 1) {
1831 end_report();
1832 return 1;
1833 }
1834 else {
1835 return;
1836 }
1837}
1838
32bbadc6
SF
1839sub _DB__read_next_cmd
1840{
1841 my ($tid) = @_;
1842
1843 # We have a terminal, or can get one ...
1844 if (!$term) {
1845 setterm();
1846 }
1847
7e3426ea 1848 # ... and it belongs to this PID or we get one for this PID ...
32bbadc6
SF
1849 if ($term_pid != $$) {
1850 resetterm(1);
1851 }
1852
1853 # ... and we got a line of command input ...
1854 $cmd = DB::readline(
1855 "$pidprompt $tid DB"
1856 . ( '<' x $level )
1857 . ( $#hist + 1 )
1858 . ( '>' x $level ) . " "
1859 );
1860
1861 return defined($cmd);
1862}
1863
7013f40c 1864sub _DB__trim_command_and_return_first_component {
af84fb69
SF
1865 my ($obj) = @_;
1866
7013f40c
SF
1867 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1868 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1869
3249b113 1870 my ($verb, $args) = $cmd =~ m{\A(\S*)\s*(.*)}s;
af84fb69 1871
3249b113
SF
1872 $obj->cmd_verb($verb);
1873 $obj->cmd_args($args);
af84fb69
SF
1874
1875 return;
7013f40c
SF
1876}
1877
2a802473 1878sub _DB__handle_f_command {
a30f63cd 1879 my ($obj) = @_;
2a802473 1880
a30f63cd 1881 if ($file = $obj->cmd_args) {
2a802473
SF
1882 # help for no arguments (old-style was return from sub).
1883 if ( !$file ) {
1884 print $OUT
1885 "The old f command is now the r command.\n"; # hint
1886 print $OUT "The new f command switches filenames.\n";
1887 next CMD;
1888 } ## end if (!$file)
1889
1890 # if not in magic file list, try a close match.
1891 if ( !defined $main::{ '_<' . $file } ) {
1892 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1893 {
1894 $try = substr( $try, 2 );
1895 print $OUT "Choosing $try matching '$file':\n";
1896 $file = $try;
1897 }
1898 } ## end if (($try) = grep(m#^_<.*$file#...
1899 } ## end if (!defined $main::{ ...
1900
1901 # If not successfully switched now, we failed.
1902 if ( !defined $main::{ '_<' . $file } ) {
1903 print $OUT "No file matching '$file' is loaded.\n";
1904 next CMD;
1905 }
1906
1907 # We switched, so switch the debugger internals around.
1908 elsif ( $file ne $filename ) {
1909 *dbline = $main::{ '_<' . $file };
1910 $max = $#dbline;
1911 $filename = $file;
1912 $start = 1;
1913 $cmd = "l";
1914 } ## end elsif ($file ne $filename)
1915
1916 # We didn't switch; say we didn't.
1917 else {
1918 print $OUT "Already in $file.\n";
1919 next CMD;
1920 }
1921 }
1922
1923 return;
1924}
1925
6115a173
SF
1926sub _DB__handle_dot_command {
1927 my ($obj) = @_;
1928
1929 # . command.
601c6a23 1930 if ($obj->_is_full('.')) {
6115a173
SF
1931 $incr = -1; # stay at current line
1932
1933 # Reset everything to the old location.
1934 $start = $line;
1935 $filename = $filename_ini;
1936 *dbline = $main::{ '_<' . $filename };
1937 $max = $#dbline;
1938
1939 # Now where are we?
1940 print_lineinfo($obj->position());
1941 next CMD;
1942 }
1943
1944 return;
1945}
1946
5c2b78e7
SF
1947sub _DB__handle_y_command {
1948 my ($obj) = @_;
1949
1950 if (my ($match_level, $match_vars)
9875a6d2 1951 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) {
5c2b78e7
SF
1952
1953 # See if we've got the necessary support.
db79bf92
TC
1954 if (!eval {
1955 local @INC = @INC;
1956 pop @INC if $INC[-1] eq '.';
1957 require PadWalker; PadWalker->VERSION(0.08) }) {
84e7f475 1958 my $Err = $@;
b5679dc0 1959 _db_warn(
84e7f475
SF
1960 $Err =~ /locate/
1961 ? "PadWalker module not found - please install\n"
1962 : $Err
1963 );
1964 next CMD;
1965 }
5c2b78e7
SF
1966
1967 # Load up dumpvar if we don't have it. If we can, that is.
1968 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1969 defined &main::dumpvar
1970 or print $OUT "dumpvar.pl not available.\n"
1971 and next CMD;
1972
1973 # Got all the modules we need. Find them and print them.
1974 my @vars = split( ' ', $match_vars || '' );
1975
1976 # Find the pad.
496f5ba5 1977 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) };
5c2b78e7
SF
1978
1979 # Oops. Can't find it.
84e7f475
SF
1980 if (my $Err = $@) {
1981 $Err =~ s/ at .*//;
b5679dc0 1982 _db_warn($Err);
84e7f475
SF
1983 next CMD;
1984 }
5c2b78e7
SF
1985
1986 # Show the desired vars with dumplex().
1987 my $savout = select($OUT);
1988
1989 # Have dumplex dump the lexicals.
84e7f475
SF
1990 foreach my $key (sort keys %$h) {
1991 dumpvar::dumplex( $key, $h->{$key},
1992 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1993 @vars );
1994 }
5c2b78e7
SF
1995 select($savout);
1996 next CMD;
1997 }
1998}
1999
35cd713a
SF
2000sub _DB__handle_c_command {
2001 my ($obj) = @_;
2002
a523ec7c 2003 my $i = $obj->cmd_args;
35cd713a 2004
a523ec7c 2005 if ($i =~ m#\A[\w:]*\z#) {
35cd713a
SF
2006
2007 # Hey, show's over. The debugged program finished
2008 # executing already.
2009 next CMD if _DB__is_finished();
2010
2011 # Capture the place to put a one-time break.
a523ec7c 2012 $subname = $i;
35cd713a
SF
2013
2014 # Probably not needed, since we finish an interactive
2015 # sub-session anyway...
2016 # local $filename = $filename;
2017 # local *dbline = *dbline; # XXX Would this work?!
2018 #
2019 # The above question wonders if localizing the alias
2020 # to the magic array works or not. Since it's commented
2021 # out, we'll just leave that to speculation for now.
2022
2023 # If the "subname" isn't all digits, we'll assume it
2024 # is a subroutine name, and try to find it.
2025 if ( $subname =~ /\D/ ) { # subroutine name
2026 # Qualify it to the current package unless it's
2027 # already qualified.
2028 $subname = $package . "::" . $subname
2029 unless $subname =~ /::/;
2030
2031 # find_sub will return "file:line_number" corresponding
2032 # to where the subroutine is defined; we call find_sub,
2033 # break up the return value, and assign it in one
2034 # operation.
a523ec7c 2035 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
35cd713a
SF
2036
2037 # Force the line number to be numeric.
a523ec7c 2038 $i = $i + 0;
35cd713a
SF
2039
2040 # If we got a line number, we found the sub.
a523ec7c 2041 if ($i) {
35cd713a
SF
2042
2043 # Switch all the debugger's internals around so
2044 # we're actually working with that file.
2045 $filename = $file;
2046 *dbline = $main::{ '_<' . $filename };
2047
2048 # Mark that there's a breakpoint in this file.
2049 $had_breakpoints{$filename} |= 1;
2050
2051 # Scan forward to the first executable line
2052 # after the 'sub whatever' line.
2053 $max = $#dbline;
a523ec7c 2054 my $_line_num = $i;
9c6fceaf
SF
2055 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2056 {
2057 $_line_num++;
2058 }
a523ec7c 2059 $i = $_line_num;
35cd713a
SF
2060 } ## end if ($i)
2061
2062 # We didn't find a sub by that name.
2063 else {
2064 print $OUT "Subroutine $subname not found.\n";
2065 next CMD;
2066 }
2067 } ## end if ($subname =~ /\D/)
2068
2069 # At this point, either the subname was all digits (an
2070 # absolute line-break request) or we've scanned through
2071 # the code following the definition of the sub, looking
2072 # for an executable, which we may or may not have found.
2073 #
2074 # If $i (which we set $subname from) is non-zero, we
2075 # got a request to break at some line somewhere. On
2076 # one hand, if there wasn't any real subroutine name
2077 # involved, this will be a request to break in the current
2078 # file at the specified line, so we have to check to make
2079 # sure that the line specified really is breakable.
2080 #
2081 # On the other hand, if there was a subname supplied, the
2082 # preceding block has moved us to the proper file and
2083 # location within that file, and then scanned forward
2084 # looking for the next executable line. We have to make
2085 # sure that one was found.
2086 #
2087 # On the gripping hand, we can't do anything unless the
2088 # current value of $i points to a valid breakable line.
2089 # Check that.
a523ec7c 2090 if ($i) {
35cd713a
SF
2091
2092 # Breakable?
a523ec7c
SF
2093 if ( $dbline[$i] == 0 ) {
2094 print $OUT "Line $i not breakable.\n";
35cd713a
SF
2095 next CMD;
2096 }
2097
2098 # Yes. Set up the one-time-break sigil.
a523ec7c
SF
2099 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2100 _enable_breakpoint_temp_enabled_status($filename, $i);
35cd713a
SF
2101 } ## end if ($i)
2102
2103 # Turn off stack tracing from here up.
a523ec7c
SF
2104 for my $j (0 .. $stack_depth) {
2105 $stack[ $j ] &= ~1;
35cd713a
SF
2106 }
2107 last CMD;
2108 }
2109
2110 return;
2111}
2112
a4d311a3
SF
2113sub _DB__handle_forward_slash_command {
2114 my ($obj) = @_;
2115
2116 # The pattern as a string.
2117 use vars qw($inpat);
2118
2119 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2120
2121 # Remove the final slash.
2122 $inpat =~ s:([^\\])/$:$1:;
2123
2124 # If the pattern isn't null ...
2125 if ( $inpat ne "" ) {
2126
7e3426ea 2127 # Turn off warn and die processing for a bit.
a4d311a3
SF
2128 local $SIG{__DIE__};
2129 local $SIG{__WARN__};
2130
2131 # Create the pattern.
2132 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2133 if ( $@ ne "" ) {
2134
2135 # Oops. Bad pattern. No biscuit.
2136 # Print the eval error and go back for more
2137 # commands.
72c017e3 2138 print {$OUT} "$@";
a4d311a3
SF
2139 next CMD;
2140 }
2141 $obj->pat($inpat);
2142 } ## end if ($inpat ne "")
2143
2144 # Set up to stop on wrap-around.
2145 $end = $start;
2146
2147 # Don't move off the current line.
2148 $incr = -1;
2149
2150 my $pat = $obj->pat;
2151
2152 # Done in eval so nothing breaks if the pattern
2153 # does something weird.
2154 eval
2155 {
2156 no strict q/vars/;
2157 for (;;) {
2158 # Move ahead one line.
2159 ++$start;
2160
2161 # Wrap if we pass the last line.
72c017e3
SF
2162 if ($start > $max) {
2163 $start = 1;
2164 }
a4d311a3
SF
2165
2166 # Stop if we have gotten back to this line again,
2167 last if ($start == $end);
2168
2169 # A hit! (Note, though, that we are doing
2170 # case-insensitive matching. Maybe a qr//
2171 # expression would be better, so the user could
2172 # do case-sensitive matching if desired.
2173 if ($dbline[$start] =~ m/$pat/i) {
2174 if ($slave_editor) {
2175 # Handle proper escaping in the slave.
72c017e3 2176 print {$OUT} "\032\032$filename:$start:0\n";
a4d311a3
SF
2177 }
2178 else {
2179 # Just print the line normally.
72c017e3 2180 print {$OUT} "$start:\t",$dbline[$start],"\n";
a4d311a3
SF
2181 }
2182 # And quit since we found something.
2183 last;
2184 }
2185 }
2186 };
2187
2188 if ($@) {
2189 warn $@;
2190 }
2191
2192 # If we wrapped, there never was a match.
2193 if ( $start == $end ) {
2194 print {$OUT} "/$pat/: not found\n";
2195 }
2196 next CMD;
2197 }
2198
2199 return;
2200}
2201
11f0f050
SF
2202sub _DB__handle_question_mark_command {
2203 my ($obj) = @_;
2204
2205 # ? - backward pattern search.
2206 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2207
2208 # Get the pattern, remove trailing question mark.
2209 $inpat =~ s:([^\\])\?$:$1:;
2210
2211 # If we've got one ...
2212 if ( $inpat ne "" ) {
2213
2214 # Turn off die & warn handlers.
2215 local $SIG{__DIE__};
2216 local $SIG{__WARN__};
2217 eval '$inpat =~ m' . "\a$inpat\a";
2218
2219 if ( $@ ne "" ) {
2220
2221 # Ouch. Not good. Print the error.
2222 print $OUT $@;
2223 next CMD;
2224 }
2225 $obj->pat($inpat);
2226 } ## end if ($inpat ne "")
2227
2228 # Where we are now is where to stop after wraparound.
2229 $end = $start;
2230
2231 # Don't move away from this line.
2232 $incr = -1;
2233
2234 my $pat = $obj->pat;
2235 # Search inside the eval to prevent pattern badness
2236 # from killing us.
2237 eval {
2238 no strict q/vars/;
2239 for (;;) {
2240 # Back up a line.
2241 --$start;
2242
2243 # Wrap if we pass the first line.
2244
2245 $start = $max if ($start <= 0);
2246
2247 # Quit if we get back where we started,
2248 last if ($start == $end);
2249
2250 # Match?
2251 if ($dbline[$start] =~ m/$pat/i) {
2252 if ($slave_editor) {
2253 # Yep, follow slave editor requirements.
2254 print $OUT "\032\032$filename:$start:0\n";
2255 }
2256 else {
2257 # Yep, just print normally.
2258 print $OUT "$start:\t",$dbline[$start],"\n";
2259 }
2260
2261 # Found, so done.
2262 last;
2263 }
2264 }
2265 };
2266
2267 # Say we failed if the loop never found anything,
2268 if ( $start == $end ) {
2269 print {$OUT} "?$pat?: not found\n";
2270 }
2271 next CMD;
2272 }
2273
2274 return;
2275}
2276
5f166812
SF
2277sub _DB__handle_restart_and_rerun_commands {
2278 my ($obj) = @_;
2279
b9920278
SF
2280 my $cmd_cmd = $obj->cmd_verb;
2281 my $cmd_params = $obj->cmd_args;
5f166812
SF
2282 # R - restart execution.
2283 # rerun - controlled restart execution.
b9920278 2284 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') {
c59f1e04
SF
2285
2286 # Change directory to the initial current working directory on
2287 # the script startup, so if the debugged program changed the
2288 # directory, then we will still be able to find the path to the
2289 # the program. (perl 5 RT #121509 ).
2290 chdir ($_initial_cwd);
2291
5f166812
SF
2292 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2293
2294 # Close all non-system fds for a clean restart. A more
2295 # correct method would be to close all fds that were not
2296 # open when the process started, but this seems to be
2297 # hard. See "debugger 'R'estart and open database
2298 # connections" on p5p.
2299
2300 my $max_fd = 1024; # default if POSIX can't be loaded
2301 if (eval { require POSIX }) {
2302 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2303 }
2304
2305 if (defined $max_fd) {
2306 foreach ($^F+1 .. $max_fd-1) {
2307 next unless open FD_TO_CLOSE, "<&=$_";
2308 close(FD_TO_CLOSE);
2309 }
2310 }
2311
2312 # And run Perl again. We use exec() to keep the
2313 # PID stable (and that way $ini_pids is still valid).
2314 exec(@args) or print {$OUT} "exec failed: $!\n";
2315
2316 last CMD;
2317 }
2318
2319 return;
2320}
2321
33f361f5
SF
2322sub _DB__handle_run_command_in_pager_command {
2323 my ($obj) = @_;
2324
2325 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2326 if ( $pager =~ /^\|/ ) {
2327
2328 # Default pager is into a pipe. Redirect I/O.
2329 open( SAVEOUT, ">&STDOUT" )
b5679dc0 2330 || _db_warn("Can't save STDOUT");
33f361f5 2331 open( STDOUT, ">&OUT" )
b5679dc0 2332 || _db_warn("Can't redirect STDOUT");
33f361f5
SF
2333 } ## end if ($pager =~ /^\|/)
2334 else {
2335
2336 # Not into a pipe. STDOUT is safe.
b5679dc0 2337 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT");
33f361f5
SF
2338 }
2339
2340 # Fix up environment to record we have less if so.
2341 fix_less();
2342
2343 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2344
2345 # Couldn't open pipe to pager.
b5679dc0 2346 _db_warn("Can't pipe output to '$pager'");
33f361f5
SF
2347 if ( $pager =~ /^\|/ ) {
2348
2349 # Redirect I/O back again.
2350 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2351 || _db_warn("Can't restore DB::OUT");
33f361f5 2352 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2353 || _db_warn("Can't restore STDOUT");
33f361f5
SF
2354 close(SAVEOUT);
2355 } ## end if ($pager =~ /^\|/)
2356 else {
2357
2358 # Redirect I/O. STDOUT already safe.
2359 open( OUT, ">&STDOUT" ) # XXX: lost message
b5679dc0 2360 || _db_warn("Can't restore DB::OUT");
33f361f5
SF
2361 }
2362 next CMD;
2363 } ## end unless ($piped = open(OUT,...
2364
2365 # Set up broken-pipe handler if necessary.
2366 $SIG{PIPE} = \&DB::catch
2367 if $pager =~ /^\|/
2368 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2369
e0047406 2370 _autoflush(\*OUT);
33f361f5
SF
2371 # Save current filehandle, and put it back.
2372 $obj->selected(scalar( select(OUT) ));
2373 # Don't put it back if pager was a pipe.
2374 if ($cmd !~ /\A\|\|/)
2375 {
2376 select($obj->selected());
2377 $obj->selected("");
2378 }
2379
2380 # Trim off the pipe symbols and run the command now.
2381 $cmd =~ s#\A\|+\s*##;
2382 redo PIPE;
2383 }
2384
2385 return;
2386}
2387
321095c5
SF
2388sub _DB__handle_m_command {
2389 my ($obj) = @_;
2390
2391 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2392 methods($1);
2393 next CMD;
2394 }
2395
2396 # m expr - set up DB::eval to do the work
2397 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2398 $onetimeDump = 'methods'; # method output gets used there
2399 }
2400
2401 return;
2402}
33f361f5 2403
8e4cceb9
SF
2404sub _DB__at_end_of_every_command {
2405 my ($obj) = @_;
2406
2407 # At the end of every command:
2408 if ($obj->piped) {
2409
2410 # Unhook the pipe mechanism now.
2411 if ( $pager =~ /^\|/ ) {
2412
2413 # No error from the child.
2414 $? = 0;
2415
2416 # we cannot warn here: the handle is missing --tchrist
2417 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2418
2419 # most of the $? crud was coping with broken cshisms
2420 # $? is explicitly set to 0, so this never runs.
2421 if ($?) {
2422 print SAVEOUT "Pager '$pager' failed: ";
2423 if ( $? == -1 ) {
2424 print SAVEOUT "shell returned -1\n";
2425 }
2426 elsif ( $? >> 8 ) {
2427 print SAVEOUT ( $? & 127 )
2428 ? " (SIG#" . ( $? & 127 ) . ")"
2429 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2430 }
2431 else {
2432 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2433 }
2434 } ## end if ($?)
2435
2436 # Reopen filehandle for our output (if we can) and
2437 # restore STDOUT (if we can).
b5679dc0 2438 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9 2439 open( STDOUT, ">&SAVEOUT" )
b5679dc0 2440 || _db_warn("Can't restore STDOUT");
8e4cceb9
SF
2441
2442 # Turn off pipe exception handler if necessary.
2443 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2444
2445 # Will stop ignoring SIGPIPE if done like nohup(1)
2446 # does SIGINT but Perl doesn't give us a choice.
2447 } ## end if ($pager =~ /^\|/)
2448 else {
2449
2450 # Non-piped "pager". Just restore STDOUT.
b5679dc0 2451 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT");
8e4cceb9
SF
2452 }
2453
9b534162
HH
2454 # Let Readline know about the new filehandles.
2455 reset_IN_OUT( \*IN, \*OUT );
2456
8e4cceb9
SF
2457 # Close filehandle pager was using, restore the normal one
2458 # if necessary,
2459 close(SAVEOUT);
2460
2461 if ($obj->selected() ne "") {
2462 select($obj->selected);
2463 $obj->selected("");
2464 }
2465
2466 # No pipes now.
2467 $obj->piped("");
2468 } ## end if ($piped)
2469
2470 return;
2471}
2472
5f5eab52
SF
2473sub _DB__handle_watch_expressions
2474{
2475 my $self = shift;
2476
2477 if ( $DB::trace & 2 ) {
2478 for my $n (0 .. $#DB::to_watch) {
2479 $DB::evalarg = $DB::to_watch[$n];
2480 local $DB::onetimeDump; # Tell DB::eval() to not output results
2481
2482 # Fix context DB::eval() wants to return an array, but
2483 # we need a scalar here.
2484 my ($val) = join( "', '", DB::eval(@_) );
2485 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
2486
2487 # Did it change?
2488 if ( $val ne $DB::old_watch[$n] ) {
2489
2490 # Yep! Show the difference, and fake an interrupt.
2491 $DB::signal = 1;
2492 print {$DB::OUT} <<EOP;
2493Watchpoint $n:\t$DB::to_watch[$n] changed:
2494 old value:\t$DB::old_watch[$n]
2495 new value:\t$val
2496EOP
2497 $DB::old_watch[$n] = $val;
2498 } ## end if ($val ne $old_watch...
2499 } ## end for my $n (0 ..
2500 } ## end if ($trace & 2)
2501
2502 return;
2503}
2504
47e3b8cc
SF
2505# 't' is type.
2506# 'm' is method.
2507# 'v' is the value (i.e: method name or subroutine ref).
2508# 's' is subroutine.
23053931
SF
2509my %cmd_lookup;
2510
2511BEGIN
2512{
2513 %cmd_lookup =
47e3b8cc 2514(
c9a9a6c0 2515 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2516 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2517 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2518 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2519 'S' => { t => 'm', v => '_handle_S_command', },
2520 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2521 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2522 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2523 'f' => { t => 's', v => \&_DB__handle_f_command, },
2524 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2525 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2526 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2527 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2528 'r' => { t => 'm', v => '_handle_r_command', },
2529 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2530 'save' => { t => 'm', v => '_handle_save_command', },
2531 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2532 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2533 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2534 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2535 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2536 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2537 ('X', 'V')),
8f144dfc
SF
2538 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2539 qw(enable disable)),
2540 (map { $_ =>
2541 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2542 } qw(R rerun)),
fbe9ebae 2543 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
ce1a6808 2544 qw(a A b B e E h i l L M o O v w W)),
47e3b8cc 2545);
23053931 2546};
47e3b8cc 2547
2b0b9dd1
SF
2548sub DB {
2549
2550 # lock the debugger and get the thread id for the prompt
2551 lock($DBGR);
2552 my $tid;
2553 my $position;
2554 my ($prefix, $after, $infix);
2555 my $pat;
22fc883d 2556 my $explicit_stop;
33f361f5
SF
2557 my $piped;
2558 my $selected;
2b0b9dd1
SF
2559
2560 if ($ENV{PERL5DB_THREADED}) {
2561 $tid = eval { "[".threads->tid."]" };
2562 }
2563
610f01b9 2564 my $cmd_verb;
3249b113 2565 my $cmd_args;
35cd713a 2566
22fc883d
SF
2567 my $obj = DB::Obj->new(
2568 {
2569 position => \$position,
2570 prefix => \$prefix,
2571 after => \$after,
2572 explicit_stop => \$explicit_stop,
2573 infix => \$infix,
3249b113 2574 cmd_args => \$cmd_args,
610f01b9 2575 cmd_verb => \$cmd_verb,
a4d311a3 2576 pat => \$pat,
33f361f5
SF
2577 piped => \$piped,
2578 selected => \$selected,
22fc883d
SF
2579 },
2580 );
2581
2582 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2583
69893cff
RGS
2584 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2585 # The code being debugged may have altered them.
b0b8faca 2586 DB::save();
69893cff
RGS
2587
2588 # Since DB::DB gets called after every line, we can use caller() to
2589 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2590 # caller is returning all the extra information when called from the
69893cff 2591 # debugger.
e22ea7cc 2592 local ( $package, $filename, $line ) = caller;
6b24a4b7 2593 $filename_ini = $filename;
69893cff
RGS
2594
2595 # set up the context for DB::eval, so it can properly execute
2596 # code on behalf of the user. We add the package in so that the
2597 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2598 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2599
2600 # Create an alias to the active file magical array to simplify
2601 # the code here.
e22ea7cc 2602 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2603
69893cff 2604 # Last line in the program.
55783941 2605 $max = $#dbline;
69893cff 2606
e0cd3692
SF
2607 # The &-call is here to ascertain the mutability of @_.
2608 &_DB__determine_if_we_should_break;
69893cff
RGS
2609
2610 # Preserve the current stop-or-not, and see if any of the W
2611 # (watch expressions) has changed.
36477c24 2612 my $was_signal = $signal;
69893cff
RGS
2613
2614 # If we have any watch expressions ...
5f5eab52 2615 _DB__handle_watch_expressions($obj);
69893cff
RGS
2616
2617=head2 C<watchfunction()>
2618
2619C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2620function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2621current package, filename, and line as its parameters.
2622
b570d64b 2623The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2624debugger's context, so it has access to all of the debugger's internal
2625data structures and functions.
2626
2627C<watchfunction()> can control the debugger's actions. Any of the following
2628will cause the debugger to return control to the user's program after
2629C<watchfunction()> executes:
2630
b570d64b 2631=over 4
69893cff 2632
be9a9b1d
AT
2633=item *
2634
2635Returning a false value from the C<watchfunction()> itself.
2636
2637=item *
2638
2639Altering C<$single> to a false value.
2640
2641=item *
69893cff 2642
be9a9b1d 2643Altering C<$signal> to a false value.
69893cff 2644
be9a9b1d 2645=item *
69893cff 2646
be9a9b1d 2647Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2648check for C<watchfunction()>. This can be done with
2649
2650 $trace &= ~4;
2651
2652=back
2653
2654=cut
2655
e22ea7cc 2656 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2657 # current package, filename, and line. The function executes in
2658 # the DB:: package.
e22ea7cc
RF
2659 if ( $trace & 4 ) { # User-installed watch
2660 return
2661 if watchfunction( $package, $filename, $line )
2662 and not $single
2663 and not $was_signal
2664 and not( $trace & ~4 );
69893cff
RGS
2665 } ## end if ($trace & 4)
2666
e22ea7cc 2667 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2668 # turn off the signal now.
6027b9a3 2669 $was_signal = $signal;
69893cff
RGS
2670 $signal = 0;
2671
2672=head2 GETTING READY TO EXECUTE COMMANDS
2673
2674The debugger decides to take control if single-step mode is on, the
2675C<t> command was entered, or the user generated a signal. If the program
2676has fallen off the end, we set things up so that entering further commands
2677won't cause trouble, and we say that the program is over.
2678
2679=cut
2680
8dc67a69
SF
2681 # Make sure that we always print if asked for explicitly regardless
2682 # of $trace_to_depth .
22fc883d 2683 $explicit_stop = ($single || $was_signal);
8dc67a69 2684
69893cff
RGS
2685 # Check to see if we should grab control ($single true,
2686 # trace set appropriately, or we got a signal).
8dc67a69 2687 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2688 $obj->_DB__grab_control(@_);
69893cff
RGS
2689 } ## end if ($single || ($trace...
2690
2691=pod
2692
2693If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2694If there are any preprompt actions, execute those as well.
e219e2fb
RF
2695
2696=cut
2697
69893cff 2698 # If there's an action, do it now.
05da04df
SF
2699 if ($action) {
2700 $evalarg = $action;
e0cd3692
SF
2701 # The &-call is here to ascertain the mutability of @_.
2702 &DB::eval;
05da04df 2703 }
e219e2fb 2704
69893cff
RGS
2705 # Are we nested another level (e.g., did we evaluate a function
2706 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2707 if ( $single || $was_signal ) {
2708
69893cff 2709 # Yes, go down a level.
e22ea7cc 2710 local $level = $level + 1;
69893cff
RGS
2711
2712 # Do any pre-prompt actions.
e22ea7cc 2713 foreach $evalarg (@$pre) {
e0cd3692
SF
2714 # The &-call is here to ascertain the mutability of @_.
2715 &DB::eval;
e22ea7cc 2716 }
69893cff
RGS
2717
2718 # Complain about too much recursion if we passed the limit.
05da04df
SF
2719 if ($single & 4) {
2720 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2721 }
69893cff
RGS
2722
2723 # The line we're currently on. Set $incr to -1 to stay here
2724 # until we get a command that tells us to advance.
e22ea7cc
RF
2725 $start = $line;
2726 $incr = -1; # for backward motion.
69893cff
RGS
2727
2728 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2729 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2730
2731=head2 WHERE ARE WE?
2732
2733XXX Relocate this section?
2734
2735The debugger normally shows the line corresponding to the current line of
2736execution. Sometimes, though, we want to see the next line, or to move elsewhere
2737in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2738
be9a9b1d
AT
2739C<$incr> controls by how many lines the I<current> line should move forward
2740after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2741line shouldn't change.
2742
be9a9b1d 2743C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2744move forwards or backwards from when doing an C<L> or C<-> command.
2745
2746C<$max> tells the debugger where the last line of the current file is. It's
2747used to terminate loops most often.
2748
2749=head2 THE COMMAND LOOP
2750
2751Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2752in two parts:
2753
2754=over 4
2755
be9a9b1d
AT
2756=item *
2757
2758The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2759reads a command and then executes it.
2760
be9a9b1d
AT
2761=item *
2762
2763The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2764is wholly contained inside the C<CMD> block and only executes a command.
2765Used to handle commands running inside a pager.
2766
2767=back
2768
2769So why have two labels to restart the loop? Because sometimes, it's easier to
2770have a command I<generate> another command and then re-execute the loop to do
2771the new command. This is faster, but perhaps a bit more convoluted.
2772
2773=cut
2774
2775 # The big command dispatch loop. It keeps running until the
2776 # user yields up control again.
2777 #
2778 # If we have a terminal for input, and we get something back
2779 # from readline(), keep on processing.
6b24a4b7 2780
e22ea7cc 2781 CMD:
32bbadc6 2782 while (_DB__read_next_cmd($tid))
69893cff 2783 {
e22ea7cc 2784
8380a245 2785 share($cmd);
69893cff
RGS
2786 # ... try to execute the input as debugger commands.
2787
2788 # Don't stop running.
2789 $single = 0;
2790
2791 # No signal is active.
2792 $signal = 0;
2793
2794 # Handle continued commands (ending with \):
3d7a2a93 2795 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2796 $cmd .= DB::readline(" cont: ");
e22ea7cc 2797 redo CMD;
3d7a2a93 2798 }
69893cff
RGS
2799
2800=head4 The null command
2801
be9a9b1d 2802A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2803command out of C<$laststep> (where it was recorded previously), and copy it
2804back into C<$cmd> to be executed below. If there wasn't any previous command,
2805we'll do nothing below (no command will match). If there was, we also save it
2806in the command history and fall through to allow the command parsing to pick
2807it up.
2808
2809=cut
2810
2811 # Empty input means repeat the last command.
eeb7da96
SF
2812 if ($cmd eq '') {
2813 $cmd = $laststep;
2814 }
e22ea7cc 2815 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2816 if (length($cmd) >= 2) {
2817 push( @hist, $cmd );
2818 }
e22ea7cc 2819 push( @truehist, $cmd );
2dbd01ad
SF
2820 share(@hist);
2821 share(@truehist);
e22ea7cc
RF
2822
2823 # This is a restart point for commands that didn't arrive
2824 # via direct user input. It allows us to 'redo PIPE' to
2825 # re-execute command processing without reading a new command.
69893cff 2826 PIPE: {
af84fb69 2827 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2828
2829=head3 COMMAND ALIASES
2830
2831The debugger can create aliases for commands (these are stored in the
2832C<%alias> hash). Before a command is executed, the command loop looks it up
2833in the alias hash and substitutes the contents of the alias for the command,
2834completely replacing it.
2835
2836=cut
2837
2838 # See if there's an alias for the command, and set it up if so.
610f01b9 2839 if ( $alias{$cmd_verb} ) {
e22ea7cc 2840
69893cff
RGS
2841 # Squelch signal handling; we want to keep control here
2842 # if something goes loco during the alias eval.
2843 local $SIG{__DIE__};
2844 local $SIG{__WARN__};
2845
2846 # This is a command, so we eval it in the DEBUGGER's
2847 # scope! Otherwise, we can't see the special debugger
2848 # variables, or get to the debugger's subs. (Well, we
2849 # _could_, but why make it even more complicated?)
610f01b9 2850 eval "\$cmd =~ $alias{$cmd_verb}";
69893cff
RGS
2851 if ($@) {
2852 local $\ = '';
610f01b9 2853 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
69893cff
RGS
2854 next CMD;
2855 }
af84fb69 2856 _DB__trim_command_and_return_first_component($obj);
610f01b9 2857 } ## end if ($alias{$cmd_verb})
69893cff
RGS
2858
2859=head3 MAIN-LINE COMMANDS
2860
2861All of these commands work up to and after the program being debugged has
b570d64b 2862terminated.
69893cff
RGS
2863
2864=head4 C<q> - quit
2865
b570d64b 2866Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2867try to execute further, cleaning any restart-related stuff out of the
2868environment, and executing with the last value of C<$?>.
2869
2870=cut
2871
fbe9ebae
SF
2872 # All of these commands were remapped in perl 5.8.0;
2873 # we send them off to the secondary dispatcher (see below).
2874 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2875 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2876
610f01b9 2877 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
47e3b8cc
SF
2878 my $type = $cmd_rec->{t};
2879 my $val = $cmd_rec->{v};
2880 if ($type eq 'm') {
2881 $obj->$val();
2882 }
2883 elsif ($type eq 's') {
2884 $val->($obj);
2885 }
2886 }
69893cff 2887
611272bb 2888=head4 C<t> - trace [n]
69893cff
RGS
2889
2890Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2891If level is specified, set C<$trace_to_depth>.
69893cff 2892
69893cff
RGS
2893=head4 C<S> - list subroutines matching/not matching a pattern
2894
2895Walks through C<%sub>, checking to see whether or not to print the name.
2896
69893cff
RGS
2897=head4 C<X> - list variables in current package
2898
b570d64b 2899Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2900appropriate C<V> command and fall through.
2901
69893cff
RGS
2902=head4 C<V> - list variables
2903
b570d64b 2904Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2905
69893cff
RGS
2906=head4 C<x> - evaluate and print an expression
2907
2908Hands the expression off to C<DB::eval>, setting it up to print the value
2909via C<dumpvar.pl> instead of just printing it directly.
2910
69893cff
RGS
2911=head4 C<m> - print methods
2912
2913Just uses C<DB::methods> to determine what methods are available.
2914
69893cff
RGS
2915=head4 C<f> - switch files
2916
73decac7 2917Switch to a different filename.
69893cff 2918
69893cff
RGS
2919=head4 C<.> - return to last-executed line.
2920
2921We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2922and then we look up the line in the magical C<%dbline> hash.
2923
69893cff
RGS
2924=head4 C<-> - back one window
2925
2926We change C<$start> to be one window back; if we go back past the first line,
2927we set it to be the first line. We ser C<$incr> to put us back at the
2928currently-executing line, and then put a C<l $start +> (list one window from
2929C<$start>) in C<$cmd> to be executed later.
2930
8481f647 2931=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2932
2933In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2934problems, most notably that the default case of several commands destroying
2935the user's work in setting watchpoints, actions, etc. We wanted, however, to
2936retain the old commands for those who were used to using them or who preferred
2937them. At this point, we check for the new commands and call C<cmd_wrapper> to
2938deal with them instead of processing them in-line.
2939
69893cff
RGS
2940=head4 C<y> - List lexicals in higher scope
2941
826b9a2e 2942Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2943above the current one and then displays then using C<dumpvar.pl>.
2944
69893cff
RGS
2945=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2946
2947All of the commands below this point don't work after the program being
2948debugged has ended. All of them check to see if the program has ended; this
2949allows the commands to be relocated without worrying about a 'line of
2950demarcation' above which commands can be entered anytime, and below which
2951they can't.
2952
2953=head4 C<n> - single step, but don't trace down into subs
2954
2955Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2956when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2957so a null command knows what to re-execute.
69893cff 2958
69893cff
RGS
2959=head4 C<s> - single-step, entering subs
2960
826b9a2e 2961Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2962subs. Also saves C<s> as C<$lastcmd>.
2963
69893cff
RGS
2964=head4 C<c> - run continuously, setting an optional breakpoint
2965
2966Most of the code for this command is taken up with locating the optional
2967breakpoint, which is either a subroutine name or a line number. We set
2968the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2969in this and all call levels above this one.
2970
69893cff
RGS
2971=head4 C<r> - return from a subroutine
2972
2973For C<r> to work properly, the debugger has to stop execution again
2974immediately after the return is executed. This is done by forcing
2975single-stepping to be on in the call level above the current one. If
2976we are printing return values when a C<r> is executed, set C<$doret>
2977appropriately, and force us out of the command loop.
2978
69893cff
RGS
2979=head4 C<T> - stack trace
2980
2981Just calls C<DB::print_trace>.
2982
69893cff
RGS
2983=head4 C<w> - List window around current line.
2984
2985Just calls C<DB::cmd_w>.
2986
69893cff
RGS
2987=head4 C<W> - watch-expression processing.
2988
b570d64b 2989Just calls C<DB::cmd_W>.
69893cff 2990
69893cff
RGS
2991=head4 C</> - search forward for a string in the source
2992
ef18ae63 2993We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2994bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2995If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2996mess us up.
2997
2998=cut
2999
a4d311a3 3000 _DB__handle_forward_slash_command($obj);
69893cff
RGS
3001
3002=head4 C<?> - search backward for a string in the source
3003
3004Same as for C</>, except the loop runs backwards.
3005
3006=cut
3007
11f0f050 3008 _DB__handle_question_mark_command($obj);
69893cff
RGS
3009
3010=head4 C<$rc> - Recall command
3011
3012Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
7e3426ea 3013that the terminal supports history). It finds the command required, puts it
69893cff
RGS
3014into C<$cmd>, and redoes the loop to execute it.
3015
3016=cut
3017
e22ea7cc 3018 # $rc - recall command.
14f38b27 3019 $obj->_handle_rc_recall_command;
69893cff
RGS
3020
3021=head4 C<$sh$sh> - C<system()> command
3022
f0bb1409 3023Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and
69893cff
RGS
3024C<STDOUT> from getting messed up.
3025
3026=cut
3027
466f24c7 3028 $obj->_handle_sh_command;
69893cff
RGS
3029
3030=head4 C<$rc I<pattern> $rc> - Search command history
3031
3032Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 3033If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
3034
3035=cut
3036
0d2c714c 3037 $obj->_handle_rc_search_history_command;
69893cff 3038
ef18ae63 3039=head4 C<$sh> - Invoke a shell
69893cff 3040
f0bb1409 3041Uses C<_db_system()> to invoke a shell.
69893cff
RGS
3042
3043=cut
3044
69893cff
RGS
3045=head4 C<$sh I<command>> - Force execution of a command in a shell
3046
3047Like the above, but the command is passed to the shell. Again, we use
f0bb1409 3048C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>.
69893cff 3049
69893cff
RGS
3050=head4 C<H> - display commands in history
3051
3052Prints the contents of C<@hist> (if any).
3053
69893cff
RGS
3054=head4 C<man, doc, perldoc> - look up documentation
3055
3056Just calls C<runman()> to print the appropriate document.
3057
3058=cut
3059
c7b0c61d 3060 $obj->_handle_doc_command;
69893cff
RGS
3061
3062=head4 C<p> - print
3063
3064Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3065the bottom of the loop.
3066
69893cff
RGS
3067=head4 C<=> - define command alias
3068
3069Manipulates C<%alias> to add or list command aliases.
3070
69893cff
RGS
3071=head4 C<source> - read commands from a file.
3072
3073Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3074pick it up.
3075
d0ecd4f3 3076=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 3077
d0ecd4f3 3078This enables or disables breakpoints.
e09195af 3079
69893cff
RGS
3080=head4 C<save> - send current history to a file
3081
3082Takes the complete history, (not the shrunken version you see with C<H>),
3083and saves it to the given filename, so it can be replayed using C<source>.
3084
3085Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3086
7fddc82f
RF
3087=head4 C<R> - restart
3088
ef18ae63 3089Restart the debugger session.
7fddc82f
RF
3090
3091=head4 C<rerun> - rerun the current session
3092
3093Return to any given position in the B<true>-history list
3094
69893cff
RGS
3095=head4 C<|, ||> - pipe output through the pager.
3096
be9a9b1d 3097For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3098(the program's standard output). For C<||>, we only save C<OUT>. We open a
3099pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3100is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3101set C<$signal>, sending us back into the debugger.
3102
3103We then trim off the pipe symbols and C<redo> the command loop at the
3104C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3105reading another.
3106
3107=cut
3108
3109 # || - run command in the pager, with output to DB::OUT.
33f361f5 3110 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3111
3112=head3 END OF COMMAND PARSING
3113
ff41e38d
SF
3114Anything left in C<$cmd> at this point is a Perl expression that we want to
3115evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3116any variables we might want to address in the C<DB> package.
3117
3118=cut
3119
e22ea7cc 3120 } # PIPE:
69893cff 3121
e2b8b3e7
TC
3122 # trace an expression
3123 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/;
3124
e22ea7cc 3125 # Make sure the flag that says "the debugger's running" is
69893cff 3126 # still on, to make sure we get control again.
e22ea7cc 3127 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3128
3129 # Run *our* eval that executes in the caller's context.
e0cd3692
SF
3130 # The &-call is here to ascertain the mutability of @_.
3131 &DB::eval;
69893cff
RGS
3132
3133 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3134 if ($onetimeDump) {
3135 $onetimeDump = undef;
69893cff 3136 $onetimedumpDepth = undef;
e22ea7cc
RF
3137 }
3138 elsif ( $term_pid == $$ ) {
8380a245 3139 eval { # May run under miniperl, when not available...
c7e68384
IZ
3140 STDOUT->flush();
3141 STDERR->flush();
8380a245 3142 };
e22ea7cc 3143
69893cff 3144 # XXX If this is the master pid, print a newline.
8380a245 3145 print {$OUT} "\n";
e22ea7cc
RF
3146 }
3147 } ## end while (($term || &setterm...
69893cff
RGS
3148
3149=head3 POST-COMMAND PROCESSING
3150
3151After each command, we check to see if the command output was piped anywhere.
3152If so, we go through the necessary code to unhook the pipe and go back to
3153our standard filehandles for input and output.
3154
3155=cut
3156
e22ea7cc 3157 continue { # CMD:
8e4cceb9 3158 _DB__at_end_of_every_command($obj);
e22ea7cc 3159 } # CMD:
69893cff
RGS
3160
3161=head3 COMMAND LOOP TERMINATION
3162
3163When commands have finished executing, we come here. If the user closed the
3164input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3165evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3166C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3167The interpreter will then execute the next line and then return control to us
3168again.
3169
3170=cut
3171
3172 # No more commands? Quit.
1f874cb6 3173 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3174
3175 # Evaluate post-prompt commands.
e22ea7cc 3176 foreach $evalarg (@$post) {
e0cd3692
SF
3177 # The &-call is here to ascertain the mutability of @_.
3178 &DB::eval;
e22ea7cc
RF
3179 }
3180 } # if ($single || $signal)
69893cff
RGS
3181
3182 # Put the user's globals back where you found them.
e22ea7cc 3183 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3184 ();
3185} ## end sub DB
3186
90fd4c80
KF
3187# Because DB::Obj is used above,
3188#
3189# my $obj = DB::Obj->new(
3190#
7e3426ea 3191# The following package declaration must come before that,
90fd4c80
KF
3192# or else runtime errors will occur with
3193#
3194# PERLDB_OPTS="autotrace nonstop"
3195#
3196# ( rt#116771 )
3197BEGIN {
3198
22fc883d
SF
3199package DB::Obj;
3200
3201sub new {
3202 my $class = shift;
3203
3204 my $self = bless {}, $class;
3205
3206 $self->_init(@_);
3207
3208 return $self;
3209}
3210
3211sub _init {
3212 my ($self, $args) = @_;
3213
3214 %{$self} = (%$self, %$args);
3215
3216 return;
3217}
3218
3219{
3220 no strict 'refs';
a4d311a3 3221 foreach my $slot_name (qw(
610f01b9 3222 after explicit_stop infix pat piped position prefix selected cmd_verb
3249b113 3223 cmd_args
a4d311a3 3224 )) {
22fc883d
SF
3225 my $slot = $slot_name;
3226 *{$slot} = sub {
3227 my $self = shift;
3228
3229 if (@_) {
3230 ${ $self->{$slot} } = shift;
3231 }
3232
3233 return ${ $self->{$slot} };
3234 };
8def6eff
SF
3235
3236 *{"append_to_$slot"} = sub {
3237 my $self = shift;
3238 my $s = shift;
3239
3240 return $self->$slot($self->$slot . $s);
3241 };
22fc883d
SF
3242 }
3243}
3244
3245sub _DB_on_init__initialize_globals
3246{
3247 my $self = shift;
3248
3249 # Check for whether we should be running continuously or not.
3250 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3251 if ( $single and not $second_time++ ) {
22fc883d
SF
3252
3253 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3254 if ($runnonstop) { # Disable until signal
22fc883d
SF
3255 # If there's any call stack in place, turn off single
3256 # stepping into subs throughout the stack.
8ad70697
SF
3257 for my $i (0 .. $stack_depth) {
3258 $stack[ $i ] &= ~1;
22fc883d
SF
3259 }
3260
3261 # And we are now no longer in single-step mode.
ebd0282e 3262 $single = 0;
22fc883d
SF
3263
3264 # If we simply returned at this point, we wouldn't get
3265 # the trace info. Fall on through.
3266 # return;
3267 } ## end if ($runnonstop)
3268
8ad70697 3269 elsif ($ImmediateStop) {
22fc883d
SF
3270
3271 # We are supposed to stop here; XXX probably a break.
8ad70697 3272 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3273 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3274 # us into the command loop
3275 }
3276 } ## end if ($single and not $second_time...
3277
3278 # If we're in single-step mode, or an interrupt (real or fake)
3279 # has occurred, turn off non-stop mode.
ebd0282e 3280 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3281
3282 return;
3283}
3284
ad46ac70
SF
3285sub _my_print_lineinfo
3286{
3287 my ($self, $i, $incr_pos) = @_;
3288
18b5b545 3289 if ($frame) {
ad46ac70 3290 # Print it indented if tracing is on.
8ad70697 3291 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3292 "$i:\t$DB::dbline[$i]" . $self->after );
3293 }
3294 else {
3295 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3296 }
3297}
3298
44a07e3e 3299sub _curr_line {
18b5b545 3300 return $DB::dbline[$line];
44a07e3e
SF
3301}
3302
601c6a23
SF
3303sub _is_full {
3304 my ($self, $letter) = @_;
3305
3306 return ($DB::cmd eq $letter);
3307}
3308
22fc883d
SF
3309sub _DB__grab_control
3310{
3311 my $self = shift;
3312
3313 # Yes, grab control.
7793e5c2 3314 if ($slave_editor) {
22fc883d
SF
3315
3316 # Tell the editor to update its position.
18b5b545 3317 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3318 DB::print_lineinfo($self->position());
3319 }
3320
3321=pod
3322
3323Special check: if we're in package C<DB::fake>, we've gone through the
3324C<END> block at least once. We set up everything so that we can continue
3325to enter commands and have a valid context to be in.
3326
3327=cut
3328
3329 elsif ( $DB::package eq 'DB::fake' ) {
3330
3331 # Fallen off the end already.
3332 if (!$DB::term) {
3333 DB::setterm();
3334 }
3335
3336 DB::print_help(<<EOP);
3337Debugged program terminated. Use B<q> to quit or B<R> to restart,
3338use B<o> I<inhibit_exit> to avoid stopping after program termination,
3339B<h q>, B<h R> or B<h o> to get additional info.
3340EOP
3341
3342 # Set the DB::eval context appropriately.
0b1fcdcc
SF
3343 # At program termination disable any user actions.
3344 $DB::action = undef;
3345
22fc883d
SF
3346 $DB::package = 'main';
3347 $DB::usercontext = DB::_calc_usercontext($DB::package);
3348 } ## end elsif ($package eq 'DB::fake')
3349
3350=pod
3351
3352If the program hasn't finished executing, we scan forward to the
3353next executable line, print that out, build the prompt from the file and line
3354number information, and print that.
3355
3356=cut
3357
3358 else {
3359
3360
3361 # Still somewhere in the midst of execution. Set up the
3362 # debugger prompt.
3363 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3364 # Perl 5 ones (sorry, we don't print Klingon
3365 #module names)
3366
3367 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3368 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3369 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3370
3371 # Break up the prompt if it's really long.
3372 if ( length($self->prefix()) > 30 ) {
18b5b545 3373 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3374 $self->prefix("");
3375 $self->infix(":\t");
3376 }
3377 else {
3378 $self->infix("):\t");
3379 $self->position(
18b5b545 3380 $self->prefix . $line. $self->infix
44a07e3e 3381 . $self->_curr_line . $self->after
22fc883d
SF
3382 );
3383 }
3384
3385 # Print current line info, indenting if necessary.
18b5b545 3386 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3387
44a07e3e
SF
3388 my $i;
3389 my $line_i = sub { return $DB::dbline[$i]; };
3390
22fc883d
SF
3391 # Scan forward, stopping at either the end or the next
3392 # unbreakable line.
18b5b545 3393 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3394 { #{ vi
3395
3396 # Drop out on null statements, block closers, and comments.
44a07e3e 3397 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3398
3399 # Drop out if the user interrupted us.
ebd0282e 3400 last if $signal;
22fc883d
SF
3401
3402 # Append a newline if the line doesn't have one. Can happen
3403 # in eval'ed text, for instance.
44a07e3e 3404 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3405
3406 # Next executable line.
44a07e3e 3407 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3408 . $self->after;
8def6eff 3409 $self->append_to_position($incr_pos);
ad46ac70 3410 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3411 } ## end for ($i = $line + 1 ; $i...
3412 } ## end else [ if ($slave_editor)
3413
3414 return;
3415}
3416
174f9c5e 3417sub _handle_t_command {
9875a6d2
SF
3418 my $self = shift;
3419
3420 my $levels = $self->cmd_args();
3421
3422 if ((!length($levels)) or ($levels !~ /\D/)) {
931ac036 3423 $trace ^= 1;
174f9c5e 3424 local $\ = '';
8ad70697
SF
3425 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3426 print {$OUT} "Trace = "
931ac036 3427 . ( ( $trace & 1 )
174f9c5e
SF
3428 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3429 : "off" ) . "\n";
3430 next CMD;
3431 }
3432
3433 return;
3434}
3435
9d0b71b3
SF
3436
3437sub _handle_S_command {
3249b113
SF
3438 my $self = shift;
3439
9d0b71b3 3440 if (my ($print_all_subs, $should_reverse, $Spatt)
3249b113 3441 = $self->cmd_args =~ /\A((!)?(.+))?\z/) {
9d0b71b3
SF
3442 # $Spatt is the pattern (if any) to use.
3443 # Reverse scan?
3444 my $Srev = defined $should_reverse;
3445 # No args - print all subs.
3446 my $Snocheck = !defined $print_all_subs;
3447
3448 # Need to make these sane here.
3449 local $\ = '';
3450 local $, = '';
3451
3452 # Search through the debugger's magical hash of subs.
3453 # If $nocheck is true, just print the sub name.
3454 # Otherwise, check it against the pattern. We then use
3455 # the XOR trick to reverse the condition as required.
3456 foreach $subname ( sort( keys %sub ) ) {
3457 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3458 print $OUT $subname, "\n";
3459 }
3460 }
3461 next CMD;
3462 }
3463
3464 return;
3465}
3466
1ce985d2 3467sub _handle_V_command_and_X_command {
601c6a23 3468 my $self = shift;
1ce985d2
SF
3469
3470 $DB::cmd =~ s/^X\b/V $DB::package/;
3471
3472 # Bare V commands get the currently-being-debugged package
3473 # added.
601c6a23 3474 if ($self->_is_full('V')) {
1ce985d2
SF
3475 $DB::cmd = "V $DB::package";
3476 }
3477
3478 # V - show variables in package.
3479 if (my ($new_packname, $new_vars_str) =
3480 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3481
3482 # Save the currently selected filehandle and
3483 # force output to debugger's filehandle (dumpvar
3484 # just does "print" for output).
3485 my $savout = select($OUT);
3486
3487 # Grab package name and variables to dump.
3488 $packname = $new_packname;
3489 my @vars = split( ' ', $new_vars_str );
3490
3491 # If main::dumpvar isn't here, get it.
3492 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3493 if ( defined &main::dumpvar ) {
3494
3495 # We got it. Turn off subroutine entry/exit messages
3496 # for the moment, along with return values.
3497 local $frame = 0;
3498 local $doret = -2;
3499
3500 # must detect sigpipe failures - not catching
3501 # then will cause the debugger to die.
3502 eval {
b0b8faca 3503 main::dumpvar(
1ce985d2
SF
3504 $packname,
3505 defined $option{dumpDepth}
3506 ? $option{dumpDepth}
3507 : -1, # assume -1 unless specified
3508 @vars
3509 );
3510 };
3511
3512 # The die doesn't need to include the $@, because
3513 # it will automatically get propagated for us.
3514 if ($@) {
3515 die unless $@ =~ /dumpvar print failed/;
3516 }
3517 } ## end if (defined &main::dumpvar)
3518 else {
3519
3520 # Couldn't load dumpvar.
3521 print $OUT "dumpvar.pl not available.\n";
3522 }
3523
3524 # Restore the output filehandle, and go round again.
3525 select($savout);
3526 next CMD;
3527 }
3528
3529 return;
3530}
3531
d1450c23 3532sub _handle_dash_command {
601c6a23 3533 my $self = shift;
d1450c23 3534
601c6a23 3535 if ($self->_is_full('-')) {
d1450c23
SF
3536
3537 # back up by a window; go to 1 if back too far.
3538 $start -= $incr + $window + 1;
3539 $start = 1 if $start <= 0;
3540 $incr = $window - 1;
3541
3542 # Generate and execute a "l +" command (handled below).
3543 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3544 redo CMD;
d1450c23
SF
3545 }
3546 return;
3547}
3548
cb9d1513
SF
3549sub _n_or_s_commands_generic {
3550 my ($self, $new_val) = @_;
73c5e526 3551 # n - next
cb9d1513 3552 next CMD if DB::_DB__is_finished();
73c5e526 3553
cb9d1513
SF
3554 # Single step, but don't enter subs.
3555 $single = $new_val;
3556
3557 # Save for empty command (repeat last).
3558 $laststep = $DB::cmd;
3559 last CMD;
3560}
73c5e526 3561
cb9d1513
SF
3562sub _n_or_s {
3563 my ($self, $letter, $new_val) = @_;
3564
601c6a23 3565 if ($self->_is_full($letter)) {
cb9d1513 3566 $self->_n_or_s_commands_generic($new_val);
73c5e526 3567 }
a30f63cd 3568 else {
50a8a759
SF
3569 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3570 }
73c5e526
SF
3571
3572 return;
3573}
3574
cb9d1513
SF
3575sub _handle_n_command {
3576 my $self = shift;
3577
3578 return $self->_n_or_s('n', 2);
3579}
3580
3581sub _handle_s_command {
3582 my $self = shift;
3583
3584 return $self->_n_or_s('s', 1);
3585}
3586
573b5003
SF
3587sub _handle_r_command {
3588 my $self = shift;
f89bf53e 3589
573b5003 3590 # r - return from the current subroutine.
601c6a23 3591 if ($self->_is_full('r')) {
573b5003
SF
3592
3593 # Can't do anything if the program's over.
3594 next CMD if DB::_DB__is_finished();
3595
3596 # Turn on stack trace.
3597 $stack[$stack_depth] |= 1;
3598
3599 # Print return value unless the stack is empty.
3600 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3601 last CMD;
3602 }
3603
3604 return;
3605}
3606
d4038e14 3607sub _handle_T_command {
601c6a23
SF
3608 my $self = shift;
3609
3610 if ($self->_is_full('T')) {
d4038e14
SF
3611 DB::print_trace( $OUT, 1 ); # skip DB
3612 next CMD;
3613 }
3614
3615 return;
3616}
3617
b6e88520 3618sub _handle_w_command {
9875a6d2
SF
3619 my $self = shift;
3620
3621 DB::cmd_w( 'w', $self->cmd_args() );
3622 next CMD;
b6e88520
SF
3623
3624 return;
3625}
3626
25953301 3627sub _handle_W_command {
a523ec7c
SF
3628 my $self = shift;
3629
3630 if (my $arg = $self->cmd_args) {
25953301
SF
3631 DB::cmd_W( 'W', $arg );
3632 next CMD;
3633 }
3634
3635 return;
3636}
3637
14f38b27
SF
3638sub _handle_rc_recall_command {
3639 my $self = shift;
3640
3641 # $rc - recall command.
3642 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3643
3644 # No arguments, take one thing off history.
3645 pop(@hist) if length($DB::cmd) > 1;
3646
3647 # Relative (- found)?
3648 # Y - index back from most recent (by 1 if bare minus)
3649 # N - go to that particular command slot or the last
3650 # thing if nothing following.
14f38b27 3651
9c6fceaf
SF
3652 $self->cmd_verb(
3653 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3654 );
14f38b27
SF
3655
3656 # Pick out the command desired.
610f01b9 3657 $DB::cmd = $hist[$self->cmd_verb];
14f38b27
SF
3658
3659 # Print the command to be executed and restart the loop
3660 # with that command in the buffer.
3661 print {$OUT} $DB::cmd, "\n";
3662 redo CMD;
3663 }
3664
3665 return;
3666}
3667
0d2c714c
SF
3668sub _handle_rc_search_history_command {
3669 my $self = shift;
3670
3671 # $rc pattern $rc - find a command in the history.
3672 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3673
3674 # Create the pattern to use.
3675 my $pat = "^$arg";
3676 $self->pat($pat);
3677
3678 # Toss off last entry if length is >1 (and it always is).
3679 pop(@hist) if length($DB::cmd) > 1;
3680
9c6fceaf 3681 my $i;
0d2c714c
SF
3682
3683 # Look backward through the history.
3684 SEARCH_HIST:
3685 for ( $i = $#hist ; $i ; --$i ) {
3686 # Stop if we find it.
3687 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3688 }
3689
9c6fceaf 3690 if ( !$i ) {
0d2c714c
SF
3691
3692 # Never found it.
3693 print $OUT "No such command!\n\n";
3694 next CMD;
3695 }
3696
3697 # Found it. Put it in the buffer, print it, and process it.
9c6fceaf 3698 $DB::cmd = $hist[$i];
0d2c714c
SF
3699 print $OUT $DB::cmd, "\n";
3700 redo CMD;
3701 }
b6aeebb8
SF
3702
3703 return;
0d2c714c
SF
3704}
3705
0664c09a
SF
3706sub _handle_H_command {
3707 my $self = shift;
3708
3249b113 3709 if ($self->cmd_args =~ m#\A\*#) {
0664c09a
SF
3710 @hist = @truehist = ();
3711 print $OUT "History cleansed\n";
3712 next CMD;
3713 }
3714
3249b113 3715 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) {
0664c09a
SF
3716
3717 # Anything other than negative numbers is ignored by
3718 # the (incorrect) pattern, so this test does nothing.
3719 $end = $num ? ( $#hist - $num ) : 0;
3720
3721 # Set to the minimum if less than zero.
3722 $hist = 0 if $hist < 0;
3723
3724 # Start at the end of the array.
3725 # Stay in while we're still above the ending value.
3726 # Tick back by one each time around the loop.
3727 my $i;
3728
3729 for ( $i = $#hist ; $i > $end ; $i-- ) {
3730
3731 # Print the command unless it has no arguments.
3732 print $OUT "$i: ", $hist[$i], "\n"
3733 unless $hist[$i] =~ /^.?$/;
3734 }
3735
0664c09a
SF
3736 next CMD;