This is a live mirror of the Perl 5 development currently hosted at https://github.com/perl/perl5
perl5db: extract a function.
[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$action>.
69893cff
RGS
187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
ef18ae63 189The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
be9a9b1d
AT
190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
69893cff
RGS
193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
69893cff
RGS
200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
69893cff
RGS
204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
69893cff
RGS
214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
69893cff
RGS
218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$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
321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
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
2dbd01ad 515BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 516
e56c1e8d
SF
517BEGIN {
518 require feature;
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
521}
522
54d04a52 523# Debugger for Perl 5.00x; perl5db.pl patch level:
6b24a4b7
SF
524use vars qw($VERSION $header);
525
931d9438 526$VERSION = '1.39_05';
69893cff 527
e22ea7cc 528$header = "perl5db.pl version $VERSION";
d338d6fe 529
69893cff
RGS
530=head1 DEBUGGER ROUTINES
531
532=head2 C<DB::eval()>
533
534This function replaces straight C<eval()> inside the debugger; it simplifies
535the process of evaluating code in the user's context.
536
b570d64b 537The code to be evaluated is passed via the package global variable
69893cff
RGS
538C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
539
be9a9b1d
AT
540Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543user's current package, grabbed when C<DB::DB> got control. This causes the
544proper context to be used when the eval is actually done. Afterward, we
545restore C<$trace>, C<$single>, and C<$^D>.
69893cff
RGS
546
547Next we need to handle C<$@> without getting confused. We save C<$@> in a
b570d64b
SF
548local lexical, localize C<$saved[0]> (which is where C<save()> will put
549C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 550C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
b570d64b
SF
551considered sane by the debugger. If there was an C<eval()> error, we print
552it on the debugger's output. If C<$onetimedump> is defined, we call
553C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554'methods'. Setting it to something else causes the debugger to do the eval
555but not print the result - handy if you want to do something else with it
69893cff
RGS
556(the "watch expressions" code does this to get the value of the watch
557expression but not show it unless it matters).
558
b570d64b
SF
559In any case, we then return the list of output from C<eval> to the caller,
560and unwinding restores the former version of C<$@> in C<@saved> as well
69893cff
RGS
561(the localization of C<$saved[0]> goes away at the end of this scope).
562
563=head3 Parameters and variables influencing execution of DB::eval()
564
565C<DB::eval> isn't parameterized in the standard way; this is to keep the
566debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 567The variables listed below influence C<DB::eval()>'s execution directly.
69893cff
RGS
568
569=over 4
570
571=item C<$evalarg> - the thing to actually be eval'ed
572
be9a9b1d 573=item C<$trace> - Current state of execution tracing
69893cff 574
be9a9b1d 575=item C<$single> - Current state of single-stepping
69893cff 576
b570d64b 577=item C<$onetimeDump> - what is to be displayed after the evaluation
69893cff
RGS
578
579=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
580
581=back
582
583The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 584are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
585
586=over 4
587
588=item C<@res> - used to capture output from actual C<eval>.
589
590=item C<$otrace> - saved value of C<$trace>.
591
b570d64b 592=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
593
594=item C<$od> - saved value of C<$^D>.
595
596=item C<$saved[0]> - saved value of C<$@>.
597
b570d64b 598=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
599
600=back
601
602=head3 The problem of lexicals
603
604The context of C<DB::eval()> presents us with some problems. Obviously,
605we want to be 'sandboxed' away from the debugger's internals when we do
606the eval, but we need some way to control how punctuation variables and
b570d64b 607debugger globals are used.
69893cff
RGS
608
609We can't use local, because the code inside C<DB::eval> can see localized
610variables; and we can't use C<my> either for the same reason. The code
611in this routine compromises and uses C<my>.
612
613After this routine is over, we don't have user code executing in the debugger's
614context, so we can use C<my> freely.
615
616=cut
617
618############################################## Begin lexical danger zone
619
620# 'my' variables used here could leak into (that is, be visible in)
621# the context that the code being evaluated is executing in. This means that
622# the code could modify the debugger's variables.
623#
624# Fiddling with the debugger's context could be Bad. We insulate things as
625# much as we can.
626
6b24a4b7
SF
627use vars qw(
628 @args
629 %break_on_load
630 @cmdfhs
631 $CommandSet
632 $CreateTTY
633 $DBGR
634 @dbline
635 $dbline
636 %dbline
637 $dieLevel
638 $evalarg
639 $filename
640 $frame
641 $hist
642 $histfile
643 $histsize
644 $ImmediateStop
645 $IN
646 $inhibit_exit
647 @ini_INC
648 $ini_warn
649 $line
650 $maxtrace
651 $od
652 $onetimeDump
653 $onetimedumpDepth
654 %option
655 @options
656 $osingle
657 $otrace
658 $OUT
659 $packname
660 $pager
661 $post
662 %postponed
663 $prc
664 $pre
665 $pretype
666 $psh
667 @RememberOnROptions
668 $remoteport
669 @res
670 $rl
671 @saved
672 $signal
673 $signalLevel
674 $single
675 $start
676 $sub
677 %sub
678 $subname
679 $term
680 $trace
681 $usercontext
682 $warnLevel
683 $window
684);
685
686# Used to save @ARGV and extract any debugger-related flags.
687use vars qw(@ARGS);
688
689# Used to prevent multiple entries to diesignal()
690# (if for instance diesignal() itself dies)
691use vars qw($panic);
692
693# Used to prevent the debugger from running nonstop
694# after a restart
695use vars qw($second_time);
696
697sub _calc_usercontext {
698 my ($package) = @_;
699
700 # Cancel strict completely for the evaluated code, so the code
701 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 702 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
703 . "package $package;"; # this won't let them modify, alas
704}
705
c1051fcf 706sub eval {
69893cff 707
c1051fcf 708 # 'my' would make it visible from user code
e22ea7cc 709 # but so does local! --tchrist
69893cff 710 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
711 local @res;
712 {
e22ea7cc
RF
713
714 # Try to keep the user code from messing with us. Save these so that
715 # even if the eval'ed code changes them, we can put them back again.
716 # Needed because the user could refer directly to the debugger's
69893cff
RGS
717 # package globals (and any 'my' variables in this containing scope)
718 # inside the eval(), and we want to try to stay safe.
e22ea7cc 719 local $otrace = $trace;
69893cff
RGS
720 local $osingle = $single;
721 local $od = $^D;
722
723 # Untaint the incoming eval() argument.
724 { ($evalarg) = $evalarg =~ /(.*)/s; }
725
e22ea7cc 726 # $usercontext built in DB::DB near the comment
69893cff
RGS
727 # "set up the context for DB::eval ..."
728 # Evaluate and save any results.
e22ea7cc 729 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
730
731 # Restore those old values.
732 $trace = $otrace;
733 $single = $osingle;
734 $^D = $od;
c1051fcf 735 }
69893cff
RGS
736
737 # Save the current value of $@, and preserve it in the debugger's copy
738 # of the saved precious globals.
c1051fcf 739 my $at = $@;
69893cff
RGS
740
741 # Since we're only saving $@, we only have to localize the array element
742 # that it will be stored in.
e22ea7cc 743 local $saved[0]; # Preserve the old value of $@
7c54f46a 744 eval { DB::save() };
69893cff
RGS
745
746 # Now see whether we need to report an error back to the user.
c1051fcf 747 if ($at) {
69893cff
RGS
748 local $\ = '';
749 print $OUT $at;
750 }
751
752 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
753 # are package globals.
754 elsif ($onetimeDump) {
e22ea7cc
RF
755 if ( $onetimeDump eq 'dump' ) {
756 local $option{dumpDepth} = $onetimedumpDepth
757 if defined $onetimedumpDepth;
758 dumpit( $OUT, \@res );
759 }
760 elsif ( $onetimeDump eq 'methods' ) {
761 methods( $res[0] );
762 }
69893cff 763 } ## end elsif ($onetimeDump)
c1051fcf 764 @res;
69893cff
RGS
765} ## end sub eval
766
767############################################## End lexical danger zone
c1051fcf 768
e22ea7cc
RF
769# After this point it is safe to introduce lexicals.
770# The code being debugged will be executing in its own context, and
69893cff 771# can't see the inside of the debugger.
d338d6fe 772#
e22ea7cc 773# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
774# possible. If you make something a lexical, it's not going to be addressable
775# from outside the debugger even if you know its name.
776
d338d6fe
PP
777# This file is automatically included if you do perl -d.
778# It's probably not useful to include this yourself.
779#
e22ea7cc 780# Before venturing further into these twisty passages, it is
2f7e9187
MS
781# wise to read the perldebguts man page or risk the ire of dragons.
782#
69893cff
RGS
783# (It should be noted that perldebguts will tell you a lot about
784# the underlying mechanics of how the debugger interfaces into the
785# Perl interpreter, but not a lot about the debugger itself. The new
786# comments in this code try to address this problem.)
787
d338d6fe 788# Note that no subroutine call is possible until &DB::sub is defined
36477c24 789# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 790# true if $deep is not defined.
055fd3a9
GS
791
792# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
793
794# modified Perl debugger, to be run from Emacs in perldb-mode
795# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
796# Johan Vromans -- upgrade to 4.0 pl 10
797# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 798########################################################################
d338d6fe 799
69893cff
RGS
800=head1 DEBUGGER INITIALIZATION
801
802The debugger starts up in phases.
803
804=head2 BASIC SETUP
805
806First, it initializes the environment it wants to run in: turning off
807warnings during its own compilation, defining variables which it will need
808to avoid warnings later, setting itself up to not exit when the program
809terminates, and defaulting to printing return values for the C<r> command.
810
811=cut
812
eda6e075 813# Needed for the statement after exec():
69893cff
RGS
814#
815# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 816# compilation. Probably it would be better practice to fix the warnings,
69893cff 817# but this is how it's done at the moment.
eda6e075 818
e22ea7cc
RF
819BEGIN {
820 $ini_warn = $^W;
821 $^W = 0;
822} # Switch compilation warnings off until another BEGIN.
d12a4851 823
69893cff
RGS
824local ($^W) = 0; # Switch run-time warnings off during init.
825
2cbb2ee1
RGS
826=head2 THREADS SUPPORT
827
828If we are running under a threaded Perl, we require threads and threads::shared
829if the environment variable C<PERL5DB_THREADED> is set, to enable proper
830threaded debugger control. C<-dt> can also be used to set this.
831
832Each new thread will be announced and the debugger prompt will always inform
833you of each new thread created. It will also indicate the thread id in which
834we are currently running within the prompt like this:
835
2dbd01ad 836 [tid] DB<$i>
2cbb2ee1
RGS
837
838Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
839command prompt. The prompt will show: C<[0]> when running under threads, but
840not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
841
842While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 843will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
844in a currently executing thread, you will stay there until it completes. With
845the current implementation it is not currently possible to hop from one thread
846to another.
847
848The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
849
850Note that threading support was built into the debugger as of Perl version
851C<5.8.6> and debugger version C<1.2.8>.
852
853=cut
854
855BEGIN {
2dbd01ad
SF
856 # ensure we can share our non-threaded variables or no-op
857 if ($ENV{PERL5DB_THREADED}) {
858 require threads;
859 require threads::shared;
860 import threads::shared qw(share);
861 $DBGR;
862 share(\$DBGR);
863 lock($DBGR);
864 print "Threads support enabled\n";
865 } else {
866 *lock = sub(*) {};
867 *share = sub(*) {};
868 }
2cbb2ee1
RGS
869}
870
2218c045
SF
871# These variables control the execution of 'dumpvar.pl'.
872{
873 package dumpvar;
874 use vars qw(
875 $hashDepth
876 $arrayDepth
877 $dumpDBFiles
878 $dumpPackages
879 $quoteHighBit
880 $printUndef
881 $globPrint
882 $usageOnly
883 );
884}
69893cff 885
2218c045
SF
886# used to control die() reporting in diesignal()
887{
888 package Carp;
889 use vars qw($CarpLevel);
890}
d338d6fe 891
422c59bf 892# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 893foreach my $k (keys (%INC)) {
2dbd01ad 894 share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
895};
896
54d04a52 897# Command-line + PERLLIB:
69893cff 898# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
899@ini_INC = @INC;
900
69893cff
RGS
901# This was an attempt to clear out the previous values of various
902# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
903# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
904
69893cff
RGS
905# We set these variables to safe values. We don't want to blindly turn
906# off warnings, because other packages may still want them.
e22ea7cc
RF
907$trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
69893cff
RGS
909
910# Default to not exiting when program finishes; print the return
911# value when the 'r' command is used to return from a subroutine.
55497cff 912$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 913
6b24a4b7
SF
914use vars qw($trace_to_depth);
915
5e2b42dd
SF
916# Default to 1E9 so it won't be limited to a certain recursion depth.
917$trace_to_depth = 1E9;
bdba49ad 918
69893cff
RGS
919=head1 OPTION PROCESSING
920
b570d64b
SF
921The debugger's options are actually spread out over the debugger itself and
922C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
923subs to be called with a value. To try to make this a little easier to
924manage, the debugger uses a few data structures to define what options
925are legal and how they are to be processed.
926
927First, the C<@options> array defines the I<names> of all the options that
928are to be accepted.
929
930=cut
931
932@options = qw(
5561b870 933 CommandSet HistFile HistSize
e22ea7cc
RF
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
939 AutoTrace TTY noTTY
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
584420f0 946 DollarCaretP
e22ea7cc 947);
d12a4851 948
584420f0 949@RememberOnROptions = qw(DollarCaretP);
d12a4851 950
69893cff
RGS
951=pod
952
953Second, C<optionVars> lists the variables that each option uses to save its
954state.
955
956=cut
957
6b24a4b7
SF
958use vars qw(%optionVars);
959
69893cff 960%optionVars = (
e22ea7cc
RF
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
973 frame => \$frame,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
5561b870
AK
980 HistFile => \$histfile,
981 HistSize => \$histsize,
69893cff
RGS
982);
983
984=pod
985
986Third, C<%optionAction> defines the subroutine to be called to process each
987option.
988
b570d64b 989=cut
69893cff 990
6b24a4b7
SF
991use vars qw(%optionAction);
992
69893cff
RGS
993%optionAction = (
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
997 TTY => \&TTY,
998 noTTY => \&noTTY,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1004 pager => \&pager,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1012);
1013
69893cff
RGS
1014=pod
1015
1016Last, the C<%optionRequire> notes modules that must be C<require>d if an
1017option is used.
1018
1019=cut
d338d6fe 1020
69893cff
RGS
1021# Note that this list is not complete: several options not listed here
1022# actually require that dumpvar.pl be loaded for them to work, but are
1023# not in the table. A subsequent patch will correct this problem; for
1024# the moment, we're just recommenting, and we are NOT going to change
1025# function.
6b24a4b7
SF
1026use vars qw(%optionRequire);
1027
eda6e075 1028%optionRequire = (
69893cff
RGS
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
e22ea7cc 1032);
69893cff
RGS
1033
1034=pod
1035
1036There are a number of initialization-related variables which can be set
1037by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038variable. These are:
1039
1040=over 4
1041
1042=item C<$rl> - readline control XXX needs more explanation
1043
1044=item C<$warnLevel> - whether or not debugger takes over warning handling
1045
1046=item C<$dieLevel> - whether or not debugger takes over die handling
1047
1048=item C<$signalLevel> - whether or not debugger takes over signal handling
1049
1050=item C<$pre> - preprompt actions (array reference)
1051
1052=item C<$post> - postprompt actions (array reference)
1053
1054=item C<$pretype>
1055
1056=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1057
1058=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1059
1060=back
1061
1062=cut
d338d6fe
PP
1063
1064# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1065$rl = 1 unless defined $rl;
1066$warnLevel = 1 unless defined $warnLevel;
1067$dieLevel = 1 unless defined $dieLevel;
1068$signalLevel = 1 unless defined $signalLevel;
1069$pre = [] unless defined $pre;
1070$post = [] unless defined $post;
1071$pretype = [] unless defined $pretype;
1072$CreateTTY = 3 unless defined $CreateTTY;
1073$CommandSet = '580' unless defined $CommandSet;
1074
2cbb2ee1
RGS
1075share($rl);
1076share($warnLevel);
1077share($dieLevel);
1078share($signalLevel);
1079share($pre);
1080share($post);
1081share($pretype);
1082share($rl);
1083share($CreateTTY);
1084share($CommandSet);
1085
69893cff
RGS
1086=pod
1087
1088The default C<die>, C<warn>, and C<signal> handlers are set up.
1089
1090=cut
055fd3a9 1091
d338d6fe
PP
1092warnLevel($warnLevel);
1093dieLevel($dieLevel);
1094signalLevel($signalLevel);
055fd3a9 1095
69893cff
RGS
1096=pod
1097
1098The pager to be used is needed next. We try to get it from the
5561b870 1099environment first. If it's not defined there, we try to find it in
69893cff
RGS
1100the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101then call the C<pager()> function to save the pager name.
1102
1103=cut
1104
1105# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1106pager(
e22ea7cc 1107
69893cff 1108 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1109 defined $ENV{PAGER}
1110 ? $ENV{PAGER}
69893cff
RGS
1111
1112 # If not, see if Config.pm defines it.
e22ea7cc
RF
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
69893cff
RGS
1116
1117 # If not, fall back to 'more'.
e22ea7cc
RF
1118 : 'more'
1119 )
1120 unless defined $pager;
69893cff
RGS
1121
1122=pod
1123
1124We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1125recall character (C<!> unless otherwise defined) and the shell escape
1126character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1127neither works in the debugger at the moment.
1128
1129=cut
1130
055fd3a9 1131setman();
69893cff
RGS
1132
1133# Set up defaults for command recall and shell escape (note:
1134# these currently don't work in linemode debugging).
2218c045
SF
1135recallCommand("!") unless defined $prc;
1136shellBang("!") unless defined $psh;
69893cff
RGS
1137
1138=pod
1139
1140We then set up the gigantic string containing the debugger help.
1141We also set the limit on the number of arguments we'll display during a
1142trace.
1143
1144=cut
1145
04e43a21 1146sethelp();
69893cff
RGS
1147
1148# If we didn't get a default for the length of eval/stack trace args,
1149# set it here.
1d06cb2d 1150$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1151
1152=head2 SETTING UP THE DEBUGGER GREETING
1153
be9a9b1d 1154The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1155running, and whether the current debugger is the primary or a child.
1156
1157If we are the primary, we just hang onto our pid so we'll have it when
1158or if we start a child debugger. If we are a child, we'll set things up
1159so we'll have a unique greeting and so the parent will give us our own
1160TTY later.
1161
1162We save the current contents of the C<PERLDB_PIDS> environment variable
1163because we mess around with it. We'll also need to hang onto it because
1164we'll need it if we restart.
1165
1166Child debuggers make a label out of the current PID structure recorded in
1167PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168yet so the parent will give them one later via C<resetterm()>.
1169
1170=cut
1171
e22ea7cc 1172# Save the current contents of the environment; we're about to
69893cff 1173# much with it. We'll need this if we have to restart.
6b24a4b7 1174use vars qw($ini_pids);
f1583d8f 1175$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1176
6b24a4b7
SF
1177use vars qw ($pids $term_pid);
1178
e22ea7cc
RF
1179if ( defined $ENV{PERLDB_PIDS} ) {
1180
69893cff 1181 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1183 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1184
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1187
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1189 # the same PID.
1190
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1192 $term_pid = $$;
1193 }
1194 else {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1196 $term_pid = -1;
1197 }
1198
69893cff
RGS
1199} ## end if (defined $ENV{PERLDB_PIDS...
1200else {
e22ea7cc
RF
1201
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
619a0444 1206 $pids = "[pid=$$]";
e22ea7cc 1207 $term_pid = $$;
f1583d8f 1208}
69893cff 1209
6b24a4b7 1210use vars qw($pidprompt);
f1583d8f 1211$pidprompt = '';
69893cff
RGS
1212
1213# Sets up $emacs as a synonym for $slave_editor.
6b24a4b7 1214use vars qw($slave_editor);
69893cff
RGS
1215*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1216
1217=head2 READING THE RC FILE
1218
b570d64b 1219The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1220running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1221
b570d64b 1222=cut
69893cff
RGS
1223
1224# As noted, this test really doesn't check accurately that the debugger
1225# is running at a terminal or not.
d338d6fe 1226
6b24a4b7 1227use vars qw($rcfile);
fb4d8a6c
SF
1228{
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1232}
1233
69893cff
RGS
1234=pod
1235
1236The debugger does a safety test of the file to be read. It must be owned
1237either by the current user or root, and must only be writable by the owner.
1238
1239=cut
1240
1241# This wraps a safety test around "do" to read and evaluate the init file.
1242#
055fd3a9
GS
1243# This isn't really safe, because there's a race
1244# between checking and opening. The solution is to
1245# open and fstat the handle, but then you have to read and
1246# eval the contents. But then the silly thing gets
69893cff
RGS
1247# your lexical scope, which is unfortunate at best.
1248sub safe_do {
055fd3a9
GS
1249 my $file = shift;
1250
1251 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
055fd3a9 1254
e22ea7cc 1255 unless ( is_safe_file($file) ) {
69893cff 1256 CORE::warn <<EO_GRIPE;
055fd3a9 1257perldb: Must not source insecure rcfile $file.
b570d64b 1258 You or the superuser must be the owner, and it must not
69893cff 1259 be writable by anyone but its owner.
055fd3a9 1260EO_GRIPE
69893cff
RGS
1261 return;
1262 } ## end unless (is_safe_file($file...
055fd3a9
GS
1263
1264 do $file;
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1266} ## end sub safe_do
055fd3a9 1267
69893cff
RGS
1268# This is the safety test itself.
1269#
055fd3a9
GS
1270# Verifies that owner is either real user or superuser and that no
1271# one but owner may write to it. This function is of limited use
1272# when called on a path instead of upon a handle, because there are
1273# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1274# eventually accessed is the same as the one tested.
055fd3a9
GS
1275# Assumes that the file's existence is not in doubt.
1276sub is_safe_file {
1277 my $path = shift;
69893cff 1278 stat($path) || return; # mysteriously vaporized
e22ea7cc 1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1280
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1283 return 1;
69893cff 1284} ## end sub is_safe_file
055fd3a9 1285
69893cff 1286# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1287# exists, we safely do it.
1288if ( -f $rcfile ) {
055fd3a9 1289 safe_do("./$rcfile");
69893cff 1290}
e22ea7cc 1291
69893cff 1292# If there isn't one here, try the user's home directory.
e22ea7cc 1293elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1294 safe_do("$ENV{HOME}/$rcfile");
1295}
e22ea7cc 1296
69893cff 1297# Else try the login directory.
e22ea7cc 1298elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1299 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1300}
1301
69893cff 1302# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1303if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1305}
1306
69893cff
RGS
1307=pod
1308
1309The last thing we do during initialization is determine which subroutine is
1310to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1311the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1312(darwin).
69893cff
RGS
1313
1314=cut
1315
1316# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1318# OS/2, or on Mac OS X. This may need some expansion.
1319
1320if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1321{
b570d64b 1322 if ( defined $remoteport ) {
11653f7f
JJ
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1325 }
1326 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1330 )
1331 {
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1333 }
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1336 }
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1341 )
1342 {
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1344 }
69893cff 1345} ## end if (not defined &get_fork_TTY...
e22ea7cc 1346
dbb46cec
DQ
1347# untaint $^O, which may have been tainted by the last statement.
1348# see bug [perl #24674]
e22ea7cc
RF
1349$^O =~ m/^(.*)\z/;
1350$^O = $1;
f1583d8f 1351
d12a4851 1352# Here begin the unreadable code. It needs fixing.
055fd3a9 1353
69893cff
RGS
1354=head2 RESTART PROCESSING
1355
1356This section handles the restart command. When the C<R> command is invoked, it
1357tries to capture all of the state it can into environment variables, and
1358then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360the R command stuffed into the environment variables.
1361
b570d64b 1362 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1374
1375We chug through all these variables and plug the values saved in them
1376back into the appropriate spots in the debugger.
1377
1378=cut
1379
6b24a4b7
SF
1380use vars qw(@hist @truehist %postponed_file @typeahead);
1381
fb0fb5f4
SF
1382sub _restore_shared_globals_after_restart
1383{
1384 @hist = get_list('PERLDB_HIST');
1385 %break_on_load = get_list("PERLDB_ON_LOAD");
1386 %postponed = get_list("PERLDB_POSTPONE");
1387
1388 share(@hist);
1389 share(@truehist);
1390 share(%break_on_load);
1391 share(%postponed);
1392}
1393
e18a02a6 1394sub _restore_breakpoints_and_actions {
e22ea7cc 1395
e22ea7cc 1396 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1397
bdba49ad
SF
1398 for my $file_idx ( 0 .. $#had_breakpoints ) {
1399 my $filename = $had_breakpoints[$file_idx];
1400 my %pf = get_list("PERLDB_FILE_$file_idx");
1401 $postponed_file{ $filename } = \%pf if %pf;
1402 my @lines = sort {$a <=> $b} keys(%pf);
1403 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1404 for my $line_idx (0 .. $#lines) {
1405 _set_breakpoint_enabled_status(
1406 $filename,
1407 $lines[$line_idx],
1408 ($enabled_statuses[$line_idx] ? 1 : ''),
1409 );
1410 }
e22ea7cc 1411 }
69893cff 1412
e18a02a6
SF
1413 return;
1414}
1415
ca50076b
SF
1416sub _restore_options_after_restart
1417{
1418 my %options_map = get_list("PERLDB_OPT");
1419
1420 while ( my ( $opt, $val ) = each %options_map ) {
1421 $val =~ s/[\\\']/\\$1/g;
1422 parse_options("$opt'$val'");
1423 }
1424
1425 return;
1426}
1427
18580168
SF
1428sub _restore_globals_after_restart
1429{
1430 # restore original @INC
1431 @INC = get_list("PERLDB_INC");
1432 @ini_INC = @INC;
1433
1434 # return pre/postprompt actions and typeahead buffer
1435 $pretype = [ get_list("PERLDB_PRETYPE") ];
1436 $pre = [ get_list("PERLDB_PRE") ];
1437 $post = [ get_list("PERLDB_POST") ];
1438 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1439
1440 return;
1441}
1442
fb0fb5f4 1443
e18a02a6
SF
1444if ( exists $ENV{PERLDB_RESTART} ) {
1445
1446 # We're restarting, so we don't need the flag that says to restart anymore.
1447 delete $ENV{PERLDB_RESTART};
1448
1449 # $restart = 1;
fb0fb5f4 1450 _restore_shared_globals_after_restart();
e18a02a6
SF
1451
1452 _restore_breakpoints_and_actions();
1453
69893cff 1454 # restore options
ca50076b 1455 _restore_options_after_restart();
69893cff 1456
18580168 1457 _restore_globals_after_restart();
69893cff
RGS
1458} ## end if (exists $ENV{PERLDB_RESTART...
1459
1460=head2 SETTING UP THE TERMINAL
1461
1462Now, we'll decide how the debugger is going to interact with the user.
1463If there's no TTY, we set the debugger to run non-stop; there's not going
1464to be anyone there to enter commands.
1465
1466=cut
54d04a52 1467
6b24a4b7
SF
1468use vars qw($notty $runnonstop $console $tty $LINEINFO);
1469use vars qw($lineinfo $doccmd);
1470
d338d6fe 1471if ($notty) {
69893cff 1472 $runnonstop = 1;
2dbd01ad 1473 share($runnonstop);
69893cff 1474}
d12a4851 1475
69893cff
RGS
1476=pod
1477
1478If there is a TTY, we have to determine who it belongs to before we can
1479proceed. If this is a slave editor or graphical debugger (denoted by
1480the first command-line switch being '-emacs'), we shift this off and
1481set C<$rl> to 0 (XXX ostensibly to do straight reads).
1482
1483=cut
1484
1485else {
e22ea7cc 1486
69893cff
RGS
1487 # Is Perl being run from a slave editor or graphical debugger?
1488 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1489 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1490 $rl = 0;
1491 shift(@main::ARGV);
1492 }
e22ea7cc
RF
1493
1494 #require Term::ReadLine;
d12a4851 1495
69893cff
RGS
1496=pod
1497
1498We then determine what the console should be on various systems:
1499
1500=over 4
1501
1502=item * Cygwin - We use C<stdin> instead of a separate device.
1503
1504=cut
1505
e22ea7cc
RF
1506 if ( $^O eq 'cygwin' ) {
1507
69893cff
RGS
1508 # /dev/tty is binary. use stdin for textmode
1509 undef $console;
1510 }
1511
1512=item * Unix - use C</dev/tty>.
1513
1514=cut
1515
e22ea7cc 1516 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1517 $console = "/dev/tty";
1518 }
1519
1520=item * Windows or MSDOS - use C<con>.
1521
1522=cut
1523
e22ea7cc 1524 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1525 $console = "con";
1526 }
1527
69893cff
RGS
1528=item * VMS - use C<sys$command>.
1529
1530=cut
1531
1532 else {
e22ea7cc 1533
69893cff
RGS
1534 # everything else is ...
1535 $console = "sys\$command";
d12a4851 1536 }
69893cff
RGS
1537
1538=pod
1539
1540=back
1541
1542Several other systems don't use a specific console. We C<undef $console>
1543for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1544with a slave editor, Epoc).
1545
1546=cut
d12a4851 1547
e22ea7cc
RF
1548 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1549
69893cff 1550 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1551 $console = undef;
1552 }
1553
1554 if ( $^O eq 'NetWare' ) {
d12a4851 1555
69893cff
RGS
1556 # /dev/tty is binary. use stdin for textmode
1557 $console = undef;
1558 }
d12a4851 1559
69893cff
RGS
1560 # In OS/2, we need to use STDIN to get textmode too, even though
1561 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1562 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1563 { # In OS/2
1564 $console = undef;
1565 }
1566
1567 # EPOC also falls into the 'got to use STDIN' camp.
1568 if ( $^O eq 'epoc' ) {
1569 $console = undef;
1570 }
d12a4851 1571
69893cff
RGS
1572=pod
1573
1574If there is a TTY hanging around from a parent, we use that as the console.
1575
1576=cut
1577
e22ea7cc 1578 $console = $tty if defined $tty;
d12a4851 1579
b570d64b 1580=head2 SOCKET HANDLING
69893cff
RGS
1581
1582The debugger is capable of opening a socket and carrying out a debugging
1583session over the socket.
1584
1585If C<RemotePort> was defined in the options, the debugger assumes that it
1586should try to start a debugging session on that port. It builds the socket
1587and then tries to connect the input and output filehandles to it.
1588
1589=cut
1590
1591 # Handle socket stuff.
e22ea7cc
RF
1592
1593 if ( defined $remoteport ) {
1594
69893cff
RGS
1595 # If RemotePort was defined in the options, connect input and output
1596 # to the socket.
11653f7f 1597 $IN = $OUT = connect_remoteport();
69893cff
RGS
1598 } ## end if (defined $remoteport)
1599
1600=pod
1601
1602If no C<RemotePort> was defined, and we want to create a TTY on startup,
1603this is probably a situation where multiple debuggers are running (for example,
1604a backticked command that starts up another debugger). We create a new IN and
1605OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1606and if we can.
1607
1608=cut
1609
1610 # Non-socket.
1611 else {
e22ea7cc 1612
69893cff
RGS
1613 # Two debuggers running (probably a system or a backtick that invokes
1614 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1615 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1616 # know how, and we can.
e22ea7cc
RF
1617 create_IN_OUT(4) if $CreateTTY & 4;
1618 if ($console) {
1619
69893cff 1620 # If we have a console, check to see if there are separate ins and
cd1191f1 1621 # outs to open. (They are assumed identical if not.)
69893cff 1622
e22ea7cc
RF
1623 my ( $i, $o ) = split /,/, $console;
1624 $o = $i unless defined $o;
69893cff 1625
69893cff 1626 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1627 open( IN, "+<$i" )
1628 || open( IN, "<$i" )
1629 || open( IN, "<&STDIN" );
1630
69893cff
RGS
1631 # read/write/create/clobber out, or write/create/clobber out,
1632 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1633 open( OUT, "+>$o" )
1634 || open( OUT, ">$o" )
1635 || open( OUT, ">&STDERR" )
1636 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1637
1638 } ## end if ($console)
1639 elsif ( not defined $console ) {
1640
1641 # No console. Open STDIN.
1642 open( IN, "<&STDIN" );
1643
1644 # merge with STDERR, or with STDOUT.
1645 open( OUT, ">&STDERR" )
1646 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1647 $console = 'STDIN/OUT';
69893cff
RGS
1648 } ## end elsif (not defined $console)
1649
1650 # Keep copies of the filehandles so that when the pager runs, it
1651 # can close standard input without clobbering ours.
2b0b9dd1
SF
1652 if ($console or (not defined($console))) {
1653 $IN = \*IN;
1654 $OUT = \*OUT;
1655 }
e22ea7cc
RF
1656 } ## end elsif (from if(defined $remoteport))
1657
1658 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1659 $OUT->autoflush(1);
e22ea7cc
RF
1660
1661 # Line info goes to debugger output unless pointed elsewhere.
1662 # Pointing elsewhere makes it possible for slave editors to
1663 # keep track of file and position. We have both a filehandle
1664 # and a I/O description to keep track of.
1665 $LINEINFO = $OUT unless defined $LINEINFO;
1666 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1667 # share($LINEINFO); # <- unable to share globs
1668 share($lineinfo); #
e22ea7cc 1669
69893cff
RGS
1670=pod
1671
1672To finish initialization, we show the debugger greeting,
1673and then call the C<afterinit()> subroutine if there is one.
1674
1675=cut
d12a4851 1676
e22ea7cc
RF
1677 # Show the debugger greeting.
1678 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1679 unless ($runnonstop) {
1680 local $\ = '';
1681 local $, = '';
1682 if ( $term_pid eq '-1' ) {
1683 print $OUT "\nDaughter DB session started...\n";
1684 }
1685 else {
1686 print $OUT "\nLoading DB routines from $header\n";
1687 print $OUT (
1688 "Editor support ",
1689 $slave_editor ? "enabled" : "available", ".\n"
1690 );
1691 print $OUT
1f874cb6 1692"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1693 } ## end else [ if ($term_pid eq '-1')
1694 } ## end unless ($runnonstop)
1695} ## end else [ if ($notty)
1696
1697# XXX This looks like a bug to me.
1698# Why copy to @ARGS and then futz with @args?
d338d6fe 1699@ARGS = @ARGV;
6b24a4b7 1700# for (@args) {
69893cff
RGS
1701 # Make sure backslashes before single quotes are stripped out, and
1702 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1703 # s/\'/\\\'/g; # removed while not justified understandably
1704 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1705# }
d338d6fe 1706
e22ea7cc 1707# If there was an afterinit() sub defined, call it. It will get
69893cff 1708# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1709if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1710 afterinit();
d338d6fe 1711}
e22ea7cc 1712
69893cff 1713# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1714use vars qw($I_m_init);
1715
43aed9ee
IZ
1716$I_m_init = 1;
1717
d338d6fe
PP
1718############################################################ Subroutines
1719
69893cff
RGS
1720=head1 SUBROUTINES
1721
1722=head2 DB
1723
1724This gigantic subroutine is the heart of the debugger. Called before every
1725statement, its job is to determine if a breakpoint has been reached, and
1726stop if so; read commands from the user, parse them, and execute
b468dcb6 1727them, and then send execution off to the next statement.
69893cff
RGS
1728
1729Note that the order in which the commands are processed is very important;
1730some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1731to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1732but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1733see what's happening in any given command.
1734
1735=cut
1736
6b24a4b7
SF
1737use vars qw(
1738 $action
1739 %alias
1740 $cmd
1741 $doret
1742 $fall_off_end
1743 $file
1744 $filename_ini
1745 $finished
1746 %had_breakpoints
1747 $incr
1748 $laststep
1749 $level
1750 $max
1751 @old_watch
1752 $package
1753 $rc
1754 $sh
1755 @stack
1756 $stack_depth
1757 @to_watch
1758 $try
2c247e84 1759 $end
6b24a4b7
SF
1760);
1761
6791e41b
SF
1762sub _DB__determine_if_we_should_break
1763{
1764 # if we have something here, see if we should break.
1765 # $stop is lexical and local to this block - $action on the other hand
1766 # is global.
1767 my $stop;
1768
1769 if ( $dbline{$line}
1770 && _is_breakpoint_enabled($filename, $line)
1771 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1772 {
1773
1774 # Stop if the stop criterion says to just stop.
1775 if ( $stop eq '1' ) {
1776 $signal |= 1;
1777 }
1778
1779 # It's a conditional stop; eval it in the user's context and
1780 # see if we should stop. If so, remove the one-time sigil.
1781 elsif ($stop) {
1782 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1783 &eval;
1784 # If the breakpoint is temporary, then delete its enabled status.
1785 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1786 _cancel_breakpoint_temp_enabled_status($filename, $line);
1787 }
1788 }
1789 } ## end if ($dbline{$line} && ...
1790}
1791
8481f647
SF
1792sub _DB__is_finished {
1793 if ($finished and $level <= 1) {
1794 end_report();
1795 return 1;
1796 }
1797 else {
1798 return;
1799 }
1800}
1801
32bbadc6
SF
1802sub _DB__read_next_cmd
1803{
1804 my ($tid) = @_;
1805
1806 # We have a terminal, or can get one ...
1807 if (!$term) {
1808 setterm();
1809 }
1810
1811 # ... and it belogs to this PID or we get one for this PID ...
1812 if ($term_pid != $$) {
1813 resetterm(1);
1814 }
1815
1816 # ... and we got a line of command input ...
1817 $cmd = DB::readline(
1818 "$pidprompt $tid DB"
1819 . ( '<' x $level )
1820 . ( $#hist + 1 )
1821 . ( '>' x $level ) . " "
1822 );
1823
1824 return defined($cmd);
1825}
1826
7013f40c
SF
1827sub _DB__trim_command_and_return_first_component {
1828 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1829 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1830
1831 $cmd =~ m{\A(\S*)};
1832 return $1;
1833}
1834
2b0b9dd1
SF
1835sub DB {
1836
1837 # lock the debugger and get the thread id for the prompt
1838 lock($DBGR);
1839 my $tid;
1840 my $position;
1841 my ($prefix, $after, $infix);
1842 my $pat;
22fc883d 1843 my $explicit_stop;
2b0b9dd1
SF
1844
1845 if ($ENV{PERL5DB_THREADED}) {
1846 $tid = eval { "[".threads->tid."]" };
1847 }
1848
22fc883d
SF
1849 my $obj = DB::Obj->new(
1850 {
1851 position => \$position,
1852 prefix => \$prefix,
1853 after => \$after,
1854 explicit_stop => \$explicit_stop,
1855 infix => \$infix,
1856 },
1857 );
1858
1859 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 1860
69893cff
RGS
1861 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1862 # The code being debugged may have altered them.
d338d6fe 1863 &save;
69893cff
RGS
1864
1865 # Since DB::DB gets called after every line, we can use caller() to
1866 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1867 # caller is returning all the extra information when called from the
69893cff 1868 # debugger.
e22ea7cc 1869 local ( $package, $filename, $line ) = caller;
6b24a4b7 1870 $filename_ini = $filename;
69893cff
RGS
1871
1872 # set up the context for DB::eval, so it can properly execute
1873 # code on behalf of the user. We add the package in so that the
1874 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1875 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1876
1877 # Create an alias to the active file magical array to simplify
1878 # the code here.
e22ea7cc 1879 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1880
69893cff 1881 # Last line in the program.
55783941 1882 $max = $#dbline;
69893cff 1883
22fc883d 1884 _DB__determine_if_we_should_break(@_);
69893cff
RGS
1885
1886 # Preserve the current stop-or-not, and see if any of the W
1887 # (watch expressions) has changed.
36477c24 1888 my $was_signal = $signal;
69893cff
RGS
1889
1890 # If we have any watch expressions ...
22fc883d 1891 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
1892
1893=head2 C<watchfunction()>
1894
1895C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1896function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1897current package, filename, and line as its parameters.
1898
b570d64b 1899The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1900debugger's context, so it has access to all of the debugger's internal
1901data structures and functions.
1902
1903C<watchfunction()> can control the debugger's actions. Any of the following
1904will cause the debugger to return control to the user's program after
1905C<watchfunction()> executes:
1906
b570d64b 1907=over 4
69893cff 1908
be9a9b1d
AT
1909=item *
1910
1911Returning a false value from the C<watchfunction()> itself.
1912
1913=item *
1914
1915Altering C<$single> to a false value.
1916
1917=item *
69893cff 1918
be9a9b1d 1919Altering C<$signal> to a false value.
69893cff 1920
be9a9b1d 1921=item *
69893cff 1922
be9a9b1d 1923Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1924check for C<watchfunction()>. This can be done with
1925
1926 $trace &= ~4;
1927
1928=back
1929
1930=cut
1931
e22ea7cc 1932 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1933 # current package, filename, and line. The function executes in
1934 # the DB:: package.
e22ea7cc
RF
1935 if ( $trace & 4 ) { # User-installed watch
1936 return
1937 if watchfunction( $package, $filename, $line )
1938 and not $single
1939 and not $was_signal
1940 and not( $trace & ~4 );
69893cff
RGS
1941 } ## end if ($trace & 4)
1942
e22ea7cc 1943 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1944 # turn off the signal now.
6027b9a3 1945 $was_signal = $signal;
69893cff
RGS
1946 $signal = 0;
1947
1948=head2 GETTING READY TO EXECUTE COMMANDS
1949
1950The debugger decides to take control if single-step mode is on, the
1951C<t> command was entered, or the user generated a signal. If the program
1952has fallen off the end, we set things up so that entering further commands
1953won't cause trouble, and we say that the program is over.
1954
1955=cut
1956
8dc67a69
SF
1957 # Make sure that we always print if asked for explicitly regardless
1958 # of $trace_to_depth .
22fc883d 1959 $explicit_stop = ($single || $was_signal);
8dc67a69 1960
69893cff
RGS
1961 # Check to see if we should grab control ($single true,
1962 # trace set appropriately, or we got a signal).
8dc67a69 1963 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 1964 $obj->_DB__grab_control(@_);
69893cff
RGS
1965 } ## end if ($single || ($trace...
1966
1967=pod
1968
1969If there's an action to be executed for the line we stopped at, execute it.
b570d64b 1970If there are any preprompt actions, execute those as well.
e219e2fb
RF
1971
1972=cut
1973
69893cff 1974 # If there's an action, do it now.
05da04df
SF
1975 if ($action) {
1976 $evalarg = $action;
1977 DB::eval();
1978 }
e219e2fb 1979
69893cff
RGS
1980 # Are we nested another level (e.g., did we evaluate a function
1981 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
1982 if ( $single || $was_signal ) {
1983
69893cff 1984 # Yes, go down a level.
e22ea7cc 1985 local $level = $level + 1;
69893cff
RGS
1986
1987 # Do any pre-prompt actions.
e22ea7cc 1988 foreach $evalarg (@$pre) {
7c54f46a 1989 DB::eval();
e22ea7cc 1990 }
69893cff
RGS
1991
1992 # Complain about too much recursion if we passed the limit.
05da04df
SF
1993 if ($single & 4) {
1994 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
1995 }
69893cff
RGS
1996
1997 # The line we're currently on. Set $incr to -1 to stay here
1998 # until we get a command that tells us to advance.
e22ea7cc
RF
1999 $start = $line;
2000 $incr = -1; # for backward motion.
69893cff
RGS
2001
2002 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2003 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2004
2005=head2 WHERE ARE WE?
2006
2007XXX Relocate this section?
2008
2009The debugger normally shows the line corresponding to the current line of
2010execution. Sometimes, though, we want to see the next line, or to move elsewhere
2011in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2012
be9a9b1d
AT
2013C<$incr> controls by how many lines the I<current> line should move forward
2014after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2015line shouldn't change.
2016
be9a9b1d 2017C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2018move forwards or backwards from when doing an C<L> or C<-> command.
2019
2020C<$max> tells the debugger where the last line of the current file is. It's
2021used to terminate loops most often.
2022
2023=head2 THE COMMAND LOOP
2024
2025Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2026in two parts:
2027
2028=over 4
2029
be9a9b1d
AT
2030=item *
2031
2032The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2033reads a command and then executes it.
2034
be9a9b1d
AT
2035=item *
2036
2037The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2038is wholly contained inside the C<CMD> block and only executes a command.
2039Used to handle commands running inside a pager.
2040
2041=back
2042
2043So why have two labels to restart the loop? Because sometimes, it's easier to
2044have a command I<generate> another command and then re-execute the loop to do
2045the new command. This is faster, but perhaps a bit more convoluted.
2046
2047=cut
2048
2049 # The big command dispatch loop. It keeps running until the
2050 # user yields up control again.
2051 #
2052 # If we have a terminal for input, and we get something back
2053 # from readline(), keep on processing.
6b24a4b7
SF
2054 my $piped;
2055 my $selected;
2056
e22ea7cc 2057 CMD:
32bbadc6 2058 while (_DB__read_next_cmd($tid))
69893cff 2059 {
e22ea7cc 2060
8380a245 2061 share($cmd);
69893cff
RGS
2062 # ... try to execute the input as debugger commands.
2063
2064 # Don't stop running.
2065 $single = 0;
2066
2067 # No signal is active.
2068 $signal = 0;
2069
2070 # Handle continued commands (ending with \):
3d7a2a93 2071 if ($cmd =~ s/\\\z/\n/) {
e22ea7cc
RF
2072 $cmd .= &readline(" cont: ");
2073 redo CMD;
3d7a2a93 2074 }
69893cff
RGS
2075
2076=head4 The null command
2077
be9a9b1d 2078A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2079command out of C<$laststep> (where it was recorded previously), and copy it
2080back into C<$cmd> to be executed below. If there wasn't any previous command,
2081we'll do nothing below (no command will match). If there was, we also save it
2082in the command history and fall through to allow the command parsing to pick
2083it up.
2084
2085=cut
2086
2087 # Empty input means repeat the last command.
e22ea7cc
RF
2088 $cmd =~ /^$/ && ( $cmd = $laststep );
2089 chomp($cmd); # get rid of the annoying extra newline
2090 push( @hist, $cmd ) if length($cmd) > 1;
2091 push( @truehist, $cmd );
2dbd01ad
SF
2092 share(@hist);
2093 share(@truehist);
e22ea7cc
RF
2094
2095 # This is a restart point for commands that didn't arrive
2096 # via direct user input. It allows us to 'redo PIPE' to
2097 # re-execute command processing without reading a new command.
69893cff 2098 PIPE: {
7013f40c 2099 my $i = _DB__trim_command_and_return_first_component();
69893cff
RGS
2100
2101=head3 COMMAND ALIASES
2102
2103The debugger can create aliases for commands (these are stored in the
2104C<%alias> hash). Before a command is executed, the command loop looks it up
2105in the alias hash and substitutes the contents of the alias for the command,
2106completely replacing it.
2107
2108=cut
2109
2110 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2111 if ( $alias{$i} ) {
2112
69893cff
RGS
2113 # Squelch signal handling; we want to keep control here
2114 # if something goes loco during the alias eval.
2115 local $SIG{__DIE__};
2116 local $SIG{__WARN__};
2117
2118 # This is a command, so we eval it in the DEBUGGER's
2119 # scope! Otherwise, we can't see the special debugger
2120 # variables, or get to the debugger's subs. (Well, we
2121 # _could_, but why make it even more complicated?)
2122 eval "\$cmd =~ $alias{$i}";
2123 if ($@) {
2124 local $\ = '';
1f874cb6 2125 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2126 next CMD;
2127 }
2128 } ## end if ($alias{$i})
2129
2130=head3 MAIN-LINE COMMANDS
2131
2132All of these commands work up to and after the program being debugged has
b570d64b 2133terminated.
69893cff
RGS
2134
2135=head4 C<q> - quit
2136
b570d64b 2137Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2138try to execute further, cleaning any restart-related stuff out of the
2139environment, and executing with the last value of C<$?>.
2140
2141=cut
2142
3d7a2a93 2143 if ($cmd eq 'q') {
69893cff
RGS
2144 $fall_off_end = 1;
2145 clean_ENV();
2146 exit $?;
3d7a2a93 2147 }
69893cff 2148
611272bb 2149=head4 C<t> - trace [n]
69893cff
RGS
2150
2151Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2152If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2153
2154=cut
2155
3d7a2a93 2156 if (my ($levels) = $cmd =~ /\At(?:\s+(\d+))?\z/) {
e22ea7cc
RF
2157 $trace ^= 1;
2158 local $\ = '';
611272bb 2159 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
e22ea7cc 2160 print $OUT "Trace = "
611272bb
PS
2161 . ( ( $trace & 1 )
2162 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2163 : "off" ) . "\n";
e22ea7cc 2164 next CMD;
3d7a2a93 2165 }
69893cff
RGS
2166
2167=head4 C<S> - list subroutines matching/not matching a pattern
2168
2169Walks through C<%sub>, checking to see whether or not to print the name.
2170
2171=cut
2172
826b9a2e
SF
2173 if (my ($print_all_subs, $should_reverse, $Spatt)
2174 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2175 # $Spatt is the pattern (if any) to use.
2176 # Reverse scan?
2177 my $Srev = defined $should_reverse;
2178 # No args - print all subs.
2179 my $Snocheck = !defined $print_all_subs;
69893cff
RGS
2180
2181 # Need to make these sane here.
e22ea7cc
RF
2182 local $\ = '';
2183 local $, = '';
69893cff
RGS
2184
2185 # Search through the debugger's magical hash of subs.
2186 # If $nocheck is true, just print the sub name.
2187 # Otherwise, check it against the pattern. We then use
2188 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2189 foreach $subname ( sort( keys %sub ) ) {
2190 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2191 print $OUT $subname, "\n";
2192 }
2193 }
2194 next CMD;
826b9a2e 2195 }
69893cff
RGS
2196
2197=head4 C<X> - list variables in current package
2198
b570d64b 2199Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2200appropriate C<V> command and fall through.
2201
2202=cut
2203
e22ea7cc 2204 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2205
2206=head4 C<V> - list variables
2207
b570d64b 2208Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2209
2210=cut
2211
2212 # Bare V commands get the currently-being-debugged package
2213 # added.
826b9a2e 2214 if ($cmd eq "V") {
e22ea7cc 2215 $cmd = "V $package";
826b9a2e 2216 }
69893cff
RGS
2217
2218 # V - show variables in package.
826b9a2e
SF
2219 if (my ($new_packname, $new_vars_str) =
2220 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
e22ea7cc 2221
69893cff
RGS
2222 # Save the currently selected filehandle and
2223 # force output to debugger's filehandle (dumpvar
2224 # just does "print" for output).
6b24a4b7 2225 my $savout = select($OUT);
69893cff
RGS
2226
2227 # Grab package name and variables to dump.
826b9a2e
SF
2228 $packname = $new_packname;
2229 my @vars = split( ' ', $new_vars_str );
69893cff
RGS
2230
2231 # If main::dumpvar isn't here, get it.
e81465be 2232 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2233 if ( defined &main::dumpvar ) {
2234
69893cff
RGS
2235 # We got it. Turn off subroutine entry/exit messages
2236 # for the moment, along with return values.
e22ea7cc
RF
2237 local $frame = 0;
2238 local $doret = -2;
69893cff
RGS
2239
2240 # must detect sigpipe failures - not catching
2241 # then will cause the debugger to die.
2242 eval {
2243 &main::dumpvar(
2244 $packname,
2245 defined $option{dumpDepth}
e22ea7cc
RF
2246 ? $option{dumpDepth}
2247 : -1, # assume -1 unless specified
69893cff 2248 @vars
e22ea7cc
RF
2249 );
2250 };
2251
2252 # The die doesn't need to include the $@, because
2253 # it will automatically get propagated for us.
2254 if ($@) {
2255 die unless $@ =~ /dumpvar print failed/;
2256 }
2257 } ## end if (defined &main::dumpvar)
2258 else {
2259
2260 # Couldn't load dumpvar.
2261 print $OUT "dumpvar.pl not available.\n";
2262 }
69893cff 2263
69893cff 2264 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2265 select($savout);
2266 next CMD;
826b9a2e 2267 }
69893cff
RGS
2268
2269=head4 C<x> - evaluate and print an expression
2270
2271Hands the expression off to C<DB::eval>, setting it up to print the value
2272via C<dumpvar.pl> instead of just printing it directly.
2273
2274=cut
2275
826b9a2e 2276 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2277 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2278
2279 # handle special "x 3 blah" syntax XXX propagate
2280 # doc back to special variables.
826b9a2e 2281 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2282 $onetimedumpDepth = $1;
2283 }
826b9a2e 2284 }
69893cff
RGS
2285
2286=head4 C<m> - print methods
2287
2288Just uses C<DB::methods> to determine what methods are available.
2289
2290=cut
2291
826b9a2e 2292 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2293 methods($1);
2294 next CMD;
826b9a2e 2295 }
69893cff
RGS
2296
2297 # m expr - set up DB::eval to do the work
826b9a2e 2298 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2299 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2300 }
69893cff
RGS
2301
2302=head4 C<f> - switch files
2303
2304=cut
2305
826b9a2e 2306 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2307 $file =~ s/\s+$//;
69893cff
RGS
2308
2309 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2310 if ( !$file ) {
2311 print $OUT
2312 "The old f command is now the r command.\n"; # hint
2313 print $OUT "The new f command switches filenames.\n";
2314 next CMD;
2315 } ## end if (!$file)
69893cff
RGS
2316
2317 # if not in magic file list, try a close match.
e22ea7cc
RF
2318 if ( !defined $main::{ '_<' . $file } ) {
2319 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2320 {
2321 $try = substr( $try, 2 );
1f874cb6 2322 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2323 $file = $try;
2324 }
2325 } ## end if (($try) = grep(m#^_<.*$file#...
2326 } ## end if (!defined $main::{ ...
69893cff
RGS
2327
2328 # If not successfully switched now, we failed.
e22ea7cc 2329 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2330 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2331 next CMD;
2332 }
69893cff 2333
e22ea7cc
RF
2334 # We switched, so switch the debugger internals around.
2335 elsif ( $file ne $filename ) {
2336 *dbline = $main::{ '_<' . $file };
2337 $max = $#dbline;
2338 $filename = $file;
2339 $start = 1;
2340 $cmd = "l";
2341 } ## end elsif ($file ne $filename)
2342
2343 # We didn't switch; say we didn't.
2344 else {
2345 print $OUT "Already in $file.\n";
2346 next CMD;
2347 }
826b9a2e 2348 }
69893cff
RGS
2349
2350=head4 C<.> - return to last-executed line.
2351
2352We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2353and then we look up the line in the magical C<%dbline> hash.
2354
2355=cut
2356
2357 # . command.
826b9a2e 2358 if ($cmd eq '.') {
e22ea7cc 2359 $incr = -1; # stay at current line
69893cff
RGS
2360
2361 # Reset everything to the old location.
e22ea7cc
RF
2362 $start = $line;
2363 $filename = $filename_ini;
2364 *dbline = $main::{ '_<' . $filename };
2365 $max = $#dbline;
69893cff
RGS
2366
2367 # Now where are we?
e22ea7cc
RF
2368 print_lineinfo($position);
2369 next CMD;
826b9a2e 2370 }
69893cff
RGS
2371
2372=head4 C<-> - back one window
2373
2374We change C<$start> to be one window back; if we go back past the first line,
2375we set it to be the first line. We ser C<$incr> to put us back at the
2376currently-executing line, and then put a C<l $start +> (list one window from
2377C<$start>) in C<$cmd> to be executed later.
2378
2379=cut
2380
2381 # - - back a window.
826b9a2e 2382 if ($cmd eq '-') {
e22ea7cc 2383
69893cff 2384 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2385 $start -= $incr + $window + 1;
2386 $start = 1 if $start <= 0;
2387 $incr = $window - 1;
69893cff
RGS
2388
2389 # Generate and execute a "l +" command (handled below).
e22ea7cc 2390 $cmd = 'l ' . ($start) . '+';
826b9a2e 2391 }
69893cff 2392
8481f647 2393=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
2394
2395In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2396problems, most notably that the default case of several commands destroying
2397the user's work in setting watchpoints, actions, etc. We wanted, however, to
2398retain the old commands for those who were used to using them or who preferred
2399them. At this point, we check for the new commands and call C<cmd_wrapper> to
2400deal with them instead of processing them in-line.
2401
2402=cut
2403
2404 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2405 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2406 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2407 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2408 next CMD;
826b9a2e 2409 }
69893cff
RGS
2410
2411=head4 C<y> - List lexicals in higher scope
2412
826b9a2e 2413Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2414above the current one and then displays then using C<dumpvar.pl>.
2415
2416=cut
2417
826b9a2e
SF
2418 if (my ($match_level, $match_vars)
2419 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2420
2421 # See if we've got the necessary support.
2422 eval { require PadWalker; PadWalker->VERSION(0.08) }
2423 or &warn(
2424 $@ =~ /locate/
2425 ? "PadWalker module not found - please install\n"
2426 : $@
2427 )
2428 and next CMD;
2429
2430 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2431 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2432 defined &main::dumpvar
2433 or print $OUT "dumpvar.pl not available.\n"
2434 and next CMD;
2435
2436 # Got all the modules we need. Find them and print them.
826b9a2e 2437 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2438
2439 # Find the pad.
826b9a2e 2440 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2441
2442 # Oops. Can't find it.
2443 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2444
2445 # Show the desired vars with dumplex().
2446 my $savout = select($OUT);
2447
2448 # Have dumplex dump the lexicals.
e22ea7cc 2449 dumpvar::dumplex( $_, $h->{$_},
69893cff 2450 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2451 @vars )
2452 for sort keys %$h;
69893cff
RGS
2453 select($savout);
2454 next CMD;
826b9a2e 2455 }
69893cff
RGS
2456
2457=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2458
2459All of the commands below this point don't work after the program being
2460debugged has ended. All of them check to see if the program has ended; this
2461allows the commands to be relocated without worrying about a 'line of
2462demarcation' above which commands can be entered anytime, and below which
2463they can't.
2464
2465=head4 C<n> - single step, but don't trace down into subs
2466
2467Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2468when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2469so a null command knows what to re-execute.
69893cff
RGS
2470
2471=cut
2472
e22ea7cc 2473 # n - next
826b9a2e 2474 if ($cmd eq 'n') {
8481f647 2475 next CMD if _DB__is_finished();
e22ea7cc 2476
69893cff
RGS
2477 # Single step, but don't enter subs.
2478 $single = 2;
e22ea7cc 2479
69893cff 2480 # Save for empty command (repeat last).
e22ea7cc
RF
2481 $laststep = $cmd;
2482 last CMD;
826b9a2e 2483 }
69893cff
RGS
2484
2485=head4 C<s> - single-step, entering subs
2486
826b9a2e 2487Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2488subs. Also saves C<s> as C<$lastcmd>.
2489
2490=cut
2491
2492 # s - single step.
826b9a2e 2493 if ($cmd eq 's') {
e22ea7cc 2494
69893cff
RGS
2495 # Get out and restart the command loop if program
2496 # has finished.
8481f647 2497 next CMD if _DB__is_finished();
e22ea7cc 2498
69893cff 2499 # Single step should enter subs.
e22ea7cc
RF
2500 $single = 1;
2501
69893cff 2502 # Save for empty command (repeat last).
e22ea7cc
RF
2503 $laststep = $cmd;
2504 last CMD;
826b9a2e 2505 }
69893cff
RGS
2506
2507=head4 C<c> - run continuously, setting an optional breakpoint
2508
2509Most of the code for this command is taken up with locating the optional
2510breakpoint, which is either a subroutine name or a line number. We set
2511the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2512in this and all call levels above this one.
2513
2514=cut
2515
2516 # c - start continuous execution.
ef18ae63 2517 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2518
69893cff
RGS
2519 # Hey, show's over. The debugged program finished
2520 # executing already.
8481f647 2521 next CMD if _DB__is_finished();
69893cff
RGS
2522
2523 # Capture the place to put a one-time break.
ef18ae63 2524 $subname = $i;
69893cff 2525
e22ea7cc
RF
2526 # Probably not needed, since we finish an interactive
2527 # sub-session anyway...
2528 # local $filename = $filename;
2529 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2530 #
2531 # The above question wonders if localizing the alias
2532 # to the magic array works or not. Since it's commented
2533 # out, we'll just leave that to speculation for now.
2534
2535 # If the "subname" isn't all digits, we'll assume it
2536 # is a subroutine name, and try to find it.
e22ea7cc
RF
2537 if ( $subname =~ /\D/ ) { # subroutine name
2538 # Qualify it to the current package unless it's
2539 # already qualified.
69893cff
RGS
2540 $subname = $package . "::" . $subname
2541 unless $subname =~ /::/;
e22ea7cc 2542
69893cff
RGS
2543 # find_sub will return "file:line_number" corresponding
2544 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2545 # break up the return value, and assign it in one
69893cff 2546 # operation.
e22ea7cc 2547 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2548
2549 # Force the line number to be numeric.
e22ea7cc 2550 $i += 0;
69893cff
RGS
2551
2552 # If we got a line number, we found the sub.
e22ea7cc
RF
2553 if ($i) {
2554
69893cff
RGS
2555 # Switch all the debugger's internals around so
2556 # we're actually working with that file.
e22ea7cc
RF
2557 $filename = $file;
2558 *dbline = $main::{ '_<' . $filename };
2559
69893cff 2560 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2561 $had_breakpoints{$filename} |= 1;
2562
69893cff
RGS
2563 # Scan forward to the first executable line
2564 # after the 'sub whatever' line.
e22ea7cc
RF
2565 $max = $#dbline;
2566 ++$i while $dbline[$i] == 0 && $i < $max;
2567 } ## end if ($i)
69893cff
RGS
2568
2569 # We didn't find a sub by that name.
e22ea7cc
RF
2570 else {
2571 print $OUT "Subroutine $subname not found.\n";
2572 next CMD;
2573 }
2574 } ## end if ($subname =~ /\D/)
69893cff
RGS
2575
2576 # At this point, either the subname was all digits (an
2577 # absolute line-break request) or we've scanned through
2578 # the code following the definition of the sub, looking
2579 # for an executable, which we may or may not have found.
2580 #
2581 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2582 # got a request to break at some line somewhere. On
2583 # one hand, if there wasn't any real subroutine name
2584 # involved, this will be a request to break in the current
2585 # file at the specified line, so we have to check to make
69893cff
RGS
2586 # sure that the line specified really is breakable.
2587 #
2588 # On the other hand, if there was a subname supplied, the
3c4b39be 2589 # preceding block has moved us to the proper file and
69893cff
RGS
2590 # location within that file, and then scanned forward
2591 # looking for the next executable line. We have to make
2592 # sure that one was found.
2593 #
2594 # On the gripping hand, we can't do anything unless the
2595 # current value of $i points to a valid breakable line.
2596 # Check that.
e22ea7cc
RF
2597 if ($i) {
2598
69893cff 2599 # Breakable?
e22ea7cc
RF
2600 if ( $dbline[$i] == 0 ) {
2601 print $OUT "Line $i not breakable.\n";
2602 next CMD;
2603 }
2604
69893cff 2605 # Yes. Set up the one-time-break sigil.
e22ea7cc 2606 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2607 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2608 } ## end if ($i)
69893cff
RGS
2609
2610 # Turn off stack tracing from here up.
2c247e84
SF
2611 for my $i (0 .. $stack_depth) {
2612 $stack[ $i ] &= ~1;
e22ea7cc
RF
2613 }
2614 last CMD;
ef18ae63 2615 }
69893cff
RGS
2616
2617=head4 C<r> - return from a subroutine
2618
2619For C<r> to work properly, the debugger has to stop execution again
2620immediately after the return is executed. This is done by forcing
2621single-stepping to be on in the call level above the current one. If
2622we are printing return values when a C<r> is executed, set C<$doret>
2623appropriately, and force us out of the command loop.
2624
2625=cut
2626
2627 # r - return from the current subroutine.
ef18ae63 2628 if ($cmd eq 'r') {
e22ea7cc 2629
98dc9551 2630 # Can't do anything if the program's over.
8481f647 2631 next CMD if _DB__is_finished();
e22ea7cc 2632
69893cff 2633 # Turn on stack trace.
e22ea7cc
RF
2634 $stack[$stack_depth] |= 1;
2635
69893cff 2636 # Print return value unless the stack is empty.
e22ea7cc
RF
2637 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2638 last CMD;
ef18ae63 2639 }
69893cff 2640
69893cff
RGS
2641=head4 C<T> - stack trace
2642
2643Just calls C<DB::print_trace>.
2644
2645=cut
2646
ef18ae63 2647 if ($cmd eq 'T') {
e22ea7cc
RF
2648 print_trace( $OUT, 1 ); # skip DB
2649 next CMD;
ef18ae63 2650 }
69893cff
RGS
2651
2652=head4 C<w> - List window around current line.
2653
2654Just calls C<DB::cmd_w>.
2655
2656=cut
2657
ef18ae63
SF
2658 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2659 &cmd_w( 'w', $arg );
2660 next CMD;
2661 }
69893cff
RGS
2662
2663=head4 C<W> - watch-expression processing.
2664
b570d64b 2665Just calls C<DB::cmd_W>.
69893cff
RGS
2666
2667=cut
2668
ef18ae63
SF
2669 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2670 &cmd_W( 'W', $arg );
2671 next CMD;
2672 }
69893cff
RGS
2673
2674=head4 C</> - search forward for a string in the source
2675
ef18ae63 2676We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2677bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2678If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2679mess us up.
2680
2681=cut
2682
ef18ae63
SF
2683 # The pattern as a string.
2684 use vars qw($inpat);
69893cff 2685
ef18ae63 2686 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2687
2688 # Remove the final slash.
e22ea7cc 2689 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2690
2691 # If the pattern isn't null ...
e22ea7cc 2692 if ( $inpat ne "" ) {
69893cff
RGS
2693
2694 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2695 local $SIG{__DIE__};
2696 local $SIG{__WARN__};
69893cff
RGS
2697
2698 # Create the pattern.
22fc883d 2699 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
e22ea7cc
RF
2700 if ( $@ ne "" ) {
2701
69893cff 2702 # Oops. Bad pattern. No biscuit.
e22ea7cc 2703 # Print the eval error and go back for more
69893cff 2704 # commands.
e22ea7cc
RF
2705 print $OUT "$@";
2706 next CMD;
2707 }
2708 $pat = $inpat;
2709 } ## end if ($inpat ne "")
69893cff
RGS
2710
2711 # Set up to stop on wrap-around.
e22ea7cc 2712 $end = $start;
69893cff
RGS
2713
2714 # Don't move off the current line.
e22ea7cc 2715 $incr = -1;
69893cff
RGS
2716
2717 # Done in eval so nothing breaks if the pattern
2718 # does something weird.
e22ea7cc 2719 eval '
22fc883d 2720 no strict q/vars/;
e22ea7cc 2721 for (;;) {
69893cff 2722 # Move ahead one line.
e22ea7cc 2723 ++$start;
69893cff
RGS
2724
2725 # Wrap if we pass the last line.
e22ea7cc 2726 $start = 1 if ($start > $max);
69893cff
RGS
2727
2728 # Stop if we have gotten back to this line again,
e22ea7cc 2729 last if ($start == $end);
69893cff
RGS
2730
2731 # A hit! (Note, though, that we are doing
2732 # case-insensitive matching. Maybe a qr//
2733 # expression would be better, so the user could
2734 # do case-sensitive matching if desired.
e22ea7cc
RF
2735 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2736 if ($slave_editor) {
69893cff 2737 # Handle proper escaping in the slave.
e22ea7cc 2738 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2739 }
e22ea7cc 2740 else {
69893cff 2741 # Just print the line normally.
e22ea7cc
RF
2742 print $OUT "$start:\t",$dbline[$start],"\n";
2743 }
69893cff 2744 # And quit since we found something.
e22ea7cc
RF
2745 last;
2746 }
2747 } ';
2748
69893cff 2749 # If we wrapped, there never was a match.
e22ea7cc
RF
2750 print $OUT "/$pat/: not found\n" if ( $start == $end );
2751 next CMD;
ef18ae63 2752 }
69893cff
RGS
2753
2754=head4 C<?> - search backward for a string in the source
2755
2756Same as for C</>, except the loop runs backwards.
2757
2758=cut
2759
2760 # ? - backward pattern search.
ef18ae63 2761 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2762
2763 # Get the pattern, remove trailing question mark.
e22ea7cc 2764 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2765
2766 # If we've got one ...
e22ea7cc 2767 if ( $inpat ne "" ) {
69893cff
RGS
2768
2769 # Turn off die & warn handlers.
e22ea7cc
RF
2770 local $SIG{__DIE__};
2771 local $SIG{__WARN__};
2772 eval '$inpat =~ m' . "\a$inpat\a";
2773
2774 if ( $@ ne "" ) {
2775
69893cff 2776 # Ouch. Not good. Print the error.
e22ea7cc
RF
2777 print $OUT $@;
2778 next CMD;
2779 }
2780 $pat = $inpat;
69893cff 2781 } ## end if ($inpat ne "")
e22ea7cc 2782
69893cff 2783 # Where we are now is where to stop after wraparound.
e22ea7cc 2784 $end = $start;
69893cff
RGS
2785
2786 # Don't move away from this line.
e22ea7cc 2787 $incr = -1;
69893cff
RGS
2788
2789 # Search inside the eval to prevent pattern badness
2790 # from killing us.
e22ea7cc 2791 eval '
22fc883d 2792 no strict q/vars/;
e22ea7cc 2793 for (;;) {
69893cff 2794 # Back up a line.
e22ea7cc 2795 --$start;
69893cff
RGS
2796
2797 # Wrap if we pass the first line.
e22ea7cc
RF
2798
2799 $start = $max if ($start <= 0);
69893cff
RGS
2800
2801 # Quit if we get back where we started,
e22ea7cc 2802 last if ($start == $end);
69893cff
RGS
2803
2804 # Match?
e22ea7cc
RF
2805 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2806 if ($slave_editor) {
69893cff 2807 # Yep, follow slave editor requirements.
e22ea7cc 2808 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2809 }
e22ea7cc 2810 else {
69893cff 2811 # Yep, just print normally.
e22ea7cc
RF
2812 print $OUT "$start:\t",$dbline[$start],"\n";
2813 }
69893cff
RGS
2814
2815 # Found, so done.
e22ea7cc
RF
2816 last;
2817 }
2818 } ';
2819
2820 # Say we failed if the loop never found anything,
2821 print $OUT "?$pat?: not found\n" if ( $start == $end );
2822 next CMD;
ef18ae63 2823 }
69893cff
RGS
2824
2825=head4 C<$rc> - Recall command
2826
2827Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2828that the terminal supports history). It find the the command required, puts it
2829into C<$cmd>, and redoes the loop to execute it.
2830
2831=cut
2832
e22ea7cc 2833 # $rc - recall command.
ef18ae63 2834 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2835
2836 # No arguments, take one thing off history.
e22ea7cc 2837 pop(@hist) if length($cmd) > 1;
69893cff 2838
e22ea7cc 2839 # Relative (- found)?
69893cff 2840 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2841 # N - go to that particular command slot or the last
69893cff 2842 # thing if nothing following.
ef18ae63 2843 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2844
2845 # Pick out the command desired.
e22ea7cc 2846 $cmd = $hist[$i];
69893cff
RGS
2847
2848 # Print the command to be executed and restart the loop
2849 # with that command in the buffer.
e22ea7cc
RF
2850 print $OUT $cmd, "\n";
2851 redo CMD;
ef18ae63 2852 }
69893cff
RGS
2853
2854=head4 C<$sh$sh> - C<system()> command
2855
2856Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2857C<STDOUT> from getting messed up.
2858
2859=cut
2860
2861 # $sh$sh - run a shell command (if it's all ASCII).
2862 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2863 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2864
69893cff 2865 # System it.
ef18ae63 2866 &system($arg);
e22ea7cc 2867 next CMD;
ef18ae63 2868 }
69893cff
RGS
2869
2870=head4 C<$rc I<pattern> $rc> - Search command history
2871
2872Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2873If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2874
2875=cut
2876
e22ea7cc 2877 # $rc pattern $rc - find a command in the history.
ef18ae63 2878 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2879
69893cff 2880 # Create the pattern to use.
ef18ae63 2881 $pat = "^$arg";
69893cff
RGS
2882
2883 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2884 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2885
2886 # Look backward through the history.
72d7d80d 2887 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2888 # Stop if we find it.
e22ea7cc
RF
2889 last if $hist[$i] =~ /$pat/;
2890 }
2891
2892 if ( !$i ) {
69893cff 2893
69893cff 2894 # Never found it.
e22ea7cc
RF
2895 print $OUT "No such command!\n\n";
2896 next CMD;
2897 }
69893cff
RGS
2898
2899 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2900 $cmd = $hist[$i];
2901 print $OUT $cmd, "\n";
2902 redo CMD;
ef18ae63 2903 }
69893cff 2904
ef18ae63 2905=head4 C<$sh> - Invoke a shell
69893cff
RGS
2906
2907Uses C<DB::system> to invoke a shell.
2908
2909=cut
2910
2911 # $sh - start a shell.
ef18ae63 2912 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2913
69893cff
RGS
2914 # Run the user's shell. If none defined, run Bourne.
2915 # We resume execution when the shell terminates.
e22ea7cc
RF
2916 &system( $ENV{SHELL} || "/bin/sh" );
2917 next CMD;
ef18ae63 2918 }
69893cff
RGS
2919
2920=head4 C<$sh I<command>> - Force execution of a command in a shell
2921
2922Like the above, but the command is passed to the shell. Again, we use
2923C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2924
2925=cut
2926
2927 # $sh command - start a shell and run a command in it.
ef18ae63 2928 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
2929
2930 # XXX: using csh or tcsh destroys sigint retvals!
2931 #&system($1); # use this instead
69893cff
RGS
2932
2933 # use the user's shell, or Bourne if none defined.
ef18ae63 2934 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 2935 next CMD;
ef18ae63 2936 }
69893cff
RGS
2937
2938=head4 C<H> - display commands in history
2939
2940Prints the contents of C<@hist> (if any).
2941
2942=cut
2943
ef18ae63 2944 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
2945 @hist = @truehist = ();
2946 print $OUT "History cleansed\n";
2947 next CMD;
ef18ae63 2948 }
e22ea7cc 2949
ef18ae63
SF
2950 if (my ($num)
2951 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
2952
2953 # Anything other than negative numbers is ignored by
69893cff 2954 # the (incorrect) pattern, so this test does nothing.
ef18ae63 2955 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
2956
2957 # Set to the minimum if less than zero.
e22ea7cc 2958 $hist = 0 if $hist < 0;
69893cff 2959
e22ea7cc 2960 # Start at the end of the array.
69893cff
RGS
2961 # Stay in while we're still above the ending value.
2962 # Tick back by one each time around the loop.
72d7d80d 2963 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
2964
2965 # Print the command unless it has no arguments.
e22ea7cc
RF
2966 print $OUT "$i: ", $hist[$i], "\n"
2967 unless $hist[$i] =~ /^.?$/;
2968 }
2969 next CMD;
ef18ae63 2970 }
69893cff
RGS
2971
2972=head4 C<man, doc, perldoc> - look up documentation
2973
2974Just calls C<runman()> to print the appropriate document.
2975
2976=cut
2977
e22ea7cc 2978 # man, perldoc, doc - show manual pages.
ef18ae63
SF
2979 if (my ($man_page)
2980 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2981 runman($man_page);
e22ea7cc 2982 next CMD;
ef18ae63 2983 }
69893cff
RGS
2984
2985=head4 C<p> - print
2986
2987Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2988the bottom of the loop.
2989
2990=cut
2991
ef18ae63 2992 my $print_cmd = 'print {$DB::OUT} ';
69893cff 2993 # p - print (no args): print $_.
ef18ae63
SF
2994 if ($cmd eq 'p') {
2995 $cmd = $print_cmd . '$_';
2996 }
69893cff
RGS
2997
2998 # p - print the given expression.
ef18ae63 2999 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
3000
3001=head4 C<=> - define command alias
3002
3003Manipulates C<%alias> to add or list command aliases.
3004
3005=cut
3006
e22ea7cc 3007 # = - set up a command alias.
ef18ae63 3008 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
3009 my @keys;
3010 if ( length $cmd == 0 ) {
3011
69893cff 3012 # No args, get current aliases.
e22ea7cc
RF
3013 @keys = sort keys %alias;
3014 }
3015 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3016
69893cff
RGS
3017 # Creating a new alias. $k is alias name, $v is
3018 # alias value.
3019
e22ea7cc
RF
3020 # can't use $_ or kill //g state
3021 for my $x ( $k, $v ) {
3022
3023 # Escape "alarm" characters.
3024 $x =~ s/\a/\\a/g;
3025 }
69893cff
RGS
3026
3027 # Substitute key for value, using alarm chars
e22ea7cc 3028 # as separators (which is why we escaped them in
69893cff 3029 # the command).
e22ea7cc 3030 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3031
3032 # Turn off standard warn and die behavior.
e22ea7cc
RF
3033 local $SIG{__DIE__};
3034 local $SIG{__WARN__};
69893cff
RGS
3035
3036 # Is it valid Perl?
e22ea7cc
RF
3037 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3038
69893cff 3039 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3040 print $OUT "Can't alias $k to $v: $@\n";
3041 delete $alias{$k};
3042 next CMD;
3043 }
3044
69893cff 3045 # We'll only list the new one.
e22ea7cc 3046 @keys = ($k);
69893cff
RGS
3047 } ## end elsif (my ($k, $v) = ($cmd...
3048
3049 # The argument is the alias to list.
e22ea7cc
RF
3050 else {
3051 @keys = ($cmd);
3052 }
69893cff
RGS
3053
3054 # List aliases.
e22ea7cc
RF
3055 for my $k (@keys) {
3056
98dc9551 3057 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
3058 # We use control-G as the delimiter because it's not
3059 # likely to appear in the alias.
e22ea7cc
RF
3060 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3061
69893cff 3062 # Print the alias.
e22ea7cc
RF
3063 print $OUT "$k\t= $1\n";
3064 }
3065 elsif ( defined $alias{$k} ) {
3066
69893cff 3067 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3068 print $OUT "$k\t$alias{$k}\n";
3069 }
3070 else {
3071
69893cff 3072 # No such, dude.
e22ea7cc
RF
3073 print "No alias for $k\n";
3074 }
69893cff 3075 } ## end for my $k (@keys)
e22ea7cc 3076 next CMD;
ef18ae63 3077 }
69893cff
RGS
3078
3079=head4 C<source> - read commands from a file.
3080
3081Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3082pick it up.
3083
3084=cut
3085
e22ea7cc 3086 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3087 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3088 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3089
69893cff 3090 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3091 push @cmdfhs, $fh;
3092 }
3093 else {
3094
3095 # Couldn't open it.
ef18ae63 3096 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3097 }
3098 next CMD;
ef18ae63 3099 }
69893cff 3100
ef18ae63
SF
3101 if (my ($which_cmd, $position)
3102 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3103
3104 my ($fn, $line_num);
3105 if ($position =~ m{\A\d+\z})
3106 {
3107 $fn = $filename;
3108 $line_num = $position;
3109 }
ef18ae63
SF
3110 elsif (my ($new_fn, $new_line_num)
3111 = $position =~ m{\A(.*):(\d+)\z}) {
3112 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3113 }
3114 else
3115 {
3116 &warn("Wrong spec for enable/disable argument.\n");
3117 }
3118
3119 if (defined($fn)) {
3120 if (_has_breakpoint_data_ref($fn, $line_num)) {
3121 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3122 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3123 );
3124 }
3125 else {
3126 &warn("No breakpoint set at ${fn}:${line_num}\n");
3127 }
3128 }
3129
3130 next CMD;
ef18ae63 3131 }
e09195af 3132
69893cff
RGS
3133=head4 C<save> - send current history to a file
3134
3135Takes the complete history, (not the shrunken version you see with C<H>),
3136and saves it to the given filename, so it can be replayed using C<source>.
3137
3138Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3139
3140=cut
3141
3142 # save source - write commands to a file for later use
ef18ae63
SF
3143 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3144 my $filename = $new_fn || '.perl5dbrc'; # default?
3145 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3146
3147 # chomp to remove extraneous newlines from source'd files
3148 chomp( my @truelist =
3149 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3150 @truehist );
3151 print $fh join( "\n", @truelist );
69893cff 3152 print "commands saved in $file\n";
e22ea7cc
RF
3153 }
3154 else {
ef18ae63 3155 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3156 }
3157 next CMD;
ef18ae63 3158 }
69893cff 3159
7fddc82f
RF
3160=head4 C<R> - restart
3161
ef18ae63 3162Restart the debugger session.
7fddc82f
RF
3163
3164=head4 C<rerun> - rerun the current session
3165
3166Return to any given position in the B<true>-history list
3167
3168=cut
3169
3170 # R - restart execution.
3171 # rerun - controlled restart execution.
ff41e38d
SF
3172 if (my ($cmd_cmd, $cmd_params) =
3173 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3174 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3175
ca28b541
AP
3176 # Close all non-system fds for a clean restart. A more
3177 # correct method would be to close all fds that were not
3178 # open when the process started, but this seems to be
3179 # hard. See "debugger 'R'estart and open database
3180 # connections" on p5p.
3181
47d3bbda 3182 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3183 if (eval { require POSIX }) {
5332cc68 3184 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3185 }
3186
3187 if (defined $max_fd) {
3188 foreach ($^F+1 .. $max_fd-1) {
3189 next unless open FD_TO_CLOSE, "<&=$_";
3190 close(FD_TO_CLOSE);
3191 }
3192 }
3193
7fddc82f
RF
3194 # And run Perl again. We use exec() to keep the
3195 # PID stable (and that way $ini_pids is still valid).
3196 exec(@args) || print $OUT "exec failed: $!\n";
3197
3198 last CMD;
ff41e38d 3199 }
7fddc82f 3200
69893cff
RGS
3201=head4 C<|, ||> - pipe output through the pager.
3202
be9a9b1d 3203For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3204(the program's standard output). For C<||>, we only save C<OUT>. We open a
3205pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3206is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3207set C<$signal>, sending us back into the debugger.
3208
3209We then trim off the pipe symbols and C<redo> the command loop at the
3210C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3211reading another.
3212
3213=cut
3214
3215 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3216 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3217 if ( $pager =~ /^\|/ ) {
3218
69893cff 3219 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3220 open( SAVEOUT, ">&STDOUT" )
3221 || &warn("Can't save STDOUT");
3222 open( STDOUT, ">&OUT" )
3223 || &warn("Can't redirect STDOUT");
69893cff 3224 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3225 else {
3226
69893cff 3227 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3228 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3229 }
69893cff
RGS
3230
3231 # Fix up environment to record we have less if so.
e22ea7cc
RF
3232 fix_less();
3233
3234 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3235
69893cff 3236 # Couldn't open pipe to pager.
1f874cb6 3237 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3238 if ( $pager =~ /^\|/ ) {
3239
69893cff 3240 # Redirect I/O back again.
e22ea7cc
RF
3241 open( OUT, ">&STDOUT" ) # XXX: lost message
3242 || &warn("Can't restore DB::OUT");
3243 open( STDOUT, ">&SAVEOUT" )
3244 || &warn("Can't restore STDOUT");
3245 close(SAVEOUT);
69893cff 3246 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3247 else {
3248
69893cff 3249 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3250 open( OUT, ">&STDOUT" ) # XXX: lost message
3251 || &warn("Can't restore DB::OUT");
3252 }
3253 next CMD;
69893cff
RGS
3254 } ## end unless ($piped = open(OUT,...
3255
3256 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3257 $SIG{PIPE} = \&DB::catch
3258 if $pager =~ /^\|/
3259 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3260
70c9432b
SF
3261 OUT->autoflush(1);
3262 # Save current filehandle, and put it back.
e22ea7cc 3263 $selected = select(OUT);
69893cff 3264 # Don't put it back if pager was a pipe.
e22ea7cc 3265 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3266
3267 # Trim off the pipe symbols and run the command now.
ff41e38d 3268 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3269 redo PIPE;
ff41e38d 3270 }
69893cff
RGS
3271
3272=head3 END OF COMMAND PARSING
3273
ff41e38d
SF
3274Anything left in C<$cmd> at this point is a Perl expression that we want to
3275evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3276any variables we might want to address in the C<DB> package.
3277
3278=cut
3279
3280 # t - turn trace on.
ff41e38d
SF
3281 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3282 my $trace_arg = $1;
3283 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3284 }
69893cff
RGS
3285
3286 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3287 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3288 $laststep = 's';
3289 }
69893cff
RGS
3290
3291 # n - single-step, but not into subs. Remember last command
e22ea7cc 3292 # was 'n'.
ff41e38d
SF
3293 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3294 $laststep = 'n';
3295 }
69893cff 3296
e22ea7cc 3297 } # PIPE:
69893cff 3298
e22ea7cc 3299 # Make sure the flag that says "the debugger's running" is
69893cff 3300 # still on, to make sure we get control again.
e22ea7cc 3301 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3302
3303 # Run *our* eval that executes in the caller's context.
7c54f46a 3304 DB::eval();
69893cff
RGS
3305
3306 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3307 if ($onetimeDump) {
3308 $onetimeDump = undef;
69893cff 3309 $onetimedumpDepth = undef;
e22ea7cc
RF
3310 }
3311 elsif ( $term_pid == $$ ) {
8380a245 3312 eval { # May run under miniperl, when not available...
c7e68384
IZ
3313 STDOUT->flush();
3314 STDERR->flush();
8380a245 3315 };
e22ea7cc 3316
69893cff 3317 # XXX If this is the master pid, print a newline.
8380a245 3318 print {$OUT} "\n";
e22ea7cc
RF
3319 }
3320 } ## end while (($term || &setterm...
69893cff
RGS
3321
3322=head3 POST-COMMAND PROCESSING
3323
3324After each command, we check to see if the command output was piped anywhere.
3325If so, we go through the necessary code to unhook the pipe and go back to
3326our standard filehandles for input and output.
3327
3328=cut
3329
e22ea7cc 3330 continue { # CMD:
69893cff
RGS
3331
3332 # At the end of every command:
e22ea7cc
RF
3333 if ($piped) {
3334
69893cff 3335 # Unhook the pipe mechanism now.
e22ea7cc
RF
3336 if ( $pager =~ /^\|/ ) {
3337
69893cff 3338 # No error from the child.
e22ea7cc 3339 $? = 0;
69893cff 3340
e22ea7cc
RF
3341 # we cannot warn here: the handle is missing --tchrist
3342 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3343
e22ea7cc 3344 # most of the $? crud was coping with broken cshisms
69893cff 3345 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3346 if ($?) {
1f874cb6 3347 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3348 if ( $? == -1 ) {
3349 print SAVEOUT "shell returned -1\n";
3350 }
3351 elsif ( $? >> 8 ) {
3352 print SAVEOUT ( $? & 127 )
3353 ? " (SIG#" . ( $? & 127 ) . ")"
3354 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3355 }
3356 else {
3357 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3358 }
69893cff
RGS
3359 } ## end if ($?)
3360
e22ea7cc 3361 # Reopen filehandle for our output (if we can) and
69893cff 3362 # restore STDOUT (if we can).
e22ea7cc
RF
3363 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3364 open( STDOUT, ">&SAVEOUT" )
3365 || &warn("Can't restore STDOUT");
69893cff
RGS
3366
3367 # Turn off pipe exception handler if necessary.
e22ea7cc 3368 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3369
e22ea7cc
RF
3370 # Will stop ignoring SIGPIPE if done like nohup(1)
3371 # does SIGINT but Perl doesn't give us a choice.
69893cff 3372 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3373 else {
3374
69893cff 3375 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3376 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3377 }
69893cff
RGS
3378
3379 # Close filehandle pager was using, restore the normal one
3380 # if necessary,
3381 close(SAVEOUT);
e22ea7cc 3382 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3383
3384 # No pipes now.
e22ea7cc 3385 $piped = "";
69893cff 3386 } ## end if ($piped)
e22ea7cc 3387 } # CMD:
69893cff
RGS
3388
3389=head3 COMMAND LOOP TERMINATION
3390
3391When commands have finished executing, we come here. If the user closed the
3392input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3393evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3394C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3395The interpreter will then execute the next line and then return control to us
3396again.
3397
3398=cut
3399
3400 # No more commands? Quit.
1f874cb6 3401 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3402
3403 # Evaluate post-prompt commands.
e22ea7cc 3404 foreach $evalarg (@$post) {
7c54f46a 3405 DB::eval();
e22ea7cc
RF
3406 }
3407 } # if ($single || $signal)
69893cff
RGS
3408
3409 # Put the user's globals back where you found them.
e22ea7cc 3410 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3411 ();
3412} ## end sub DB
3413
22fc883d
SF
3414package DB::Obj;
3415
3416sub new {
3417 my $class = shift;
3418
3419 my $self = bless {}, $class;
3420
3421 $self->_init(@_);
3422
3423 return $self;
3424}
3425
3426sub _init {
3427 my ($self, $args) = @_;
3428
3429 %{$self} = (%$self, %$args);
3430
3431 return;
3432}
3433
3434{
3435 no strict 'refs';
3436 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3437 my $slot = $slot_name;
3438 *{$slot} = sub {
3439 my $self = shift;
3440
3441 if (@_) {
3442 ${ $self->{$slot} } = shift;
3443 }
3444
3445 return ${ $self->{$slot} };
3446 };
8def6eff
SF
3447
3448 *{"append_to_$slot"} = sub {
3449 my $self = shift;
3450 my $s = shift;
3451
3452 return $self->$slot($self->$slot . $s);
3453 };
22fc883d
SF
3454 }
3455}
3456
3457sub _DB_on_init__initialize_globals
3458{
3459 my $self = shift;
3460
3461 # Check for whether we should be running continuously or not.
3462 # _After_ the perl program is compiled, $single is set to 1:
3463 if ( $DB::single and not $DB::second_time++ ) {
3464
3465 # Options say run non-stop. Run until we get an interrupt.
3466 if ($DB::runnonstop) { # Disable until signal
3467 # If there's any call stack in place, turn off single
3468 # stepping into subs throughout the stack.
3469 for my $i (0 .. $DB::stack_depth) {
3470 $DB::stack[ $i ] &= ~1;
3471 }
3472
3473 # And we are now no longer in single-step mode.
3474 $DB::single = 0;
3475
3476 # If we simply returned at this point, we wouldn't get
3477 # the trace info. Fall on through.
3478 # return;
3479 } ## end if ($runnonstop)
3480
3481 elsif ($DB::ImmediateStop) {
3482
3483 # We are supposed to stop here; XXX probably a break.
3484 $DB::ImmediateStop = 0; # We've processed it; turn it off
3485 $DB::signal = 1; # Simulate an interrupt to force
3486 # us into the command loop
3487 }
3488 } ## end if ($single and not $second_time...
3489
3490 # If we're in single-step mode, or an interrupt (real or fake)
3491 # has occurred, turn off non-stop mode.
3492 $DB::runnonstop = 0 if $DB::single or $DB::signal;
3493
3494 return;
3495}
3496
3497sub _DB__handle_watch_expressions
3498{
3499 my $self = shift;
3500
3501 if ( $DB::trace & 2 ) {
3502 for my $n (0 .. $#DB::to_watch) {
3503 $DB::evalarg = $DB::to_watch[$n];
3504 local $DB::onetimeDump; # Tell DB::eval() to not output results
3505
3506 # Fix context DB::eval() wants to return an array, but
3507 # we need a scalar here.
7c54f46a 3508 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3509 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3510
3511 # Did it change?
3512 if ( $val ne $DB::old_watch[$n] ) {
3513
3514 # Yep! Show the difference, and fake an interrupt.
3515 $DB::signal = 1;
3516 print {$DB::OUT} <<EOP;
3517Watchpoint $n:\t$DB::to_watch[$n] changed:
3518 old value:\t$DB::old_watch[$n]
3519 new value:\t$val
3520EOP
3521 $DB::old_watch[$n] = $val;
3522 } ## end if ($val ne $old_watch...
3523 } ## end for my $n (0 ..
3524 } ## end if ($trace & 2)
3525
3526 return;
3527}
3528
ad46ac70
SF
3529sub _my_print_lineinfo
3530{
3531 my ($self, $i, $incr_pos) = @_;
3532
3533 if ($DB::frame) {
3534 # Print it indented if tracing is on.
3535 DB::print_lineinfo( ' ' x $DB::stack_depth,
3536 "$i:\t$DB::dbline[$i]" . $self->after );
3537 }
3538 else {
3539 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3540 }
3541}
3542
44a07e3e
SF
3543sub _curr_line {
3544 return $DB::dbline[$DB::line];
3545}
3546
22fc883d
SF
3547sub _DB__grab_control
3548{
3549 my $self = shift;
3550
3551 # Yes, grab control.
3552 if ($DB::slave_editor) {
3553
3554 # Tell the editor to update its position.
3555 $self->position("\032\032${DB::filename}:${DB::line}:0\n");
3556 DB::print_lineinfo($self->position());
3557 }
3558
3559=pod
3560
3561Special check: if we're in package C<DB::fake>, we've gone through the
3562C<END> block at least once. We set up everything so that we can continue
3563to enter commands and have a valid context to be in.
3564
3565=cut
3566
3567 elsif ( $DB::package eq 'DB::fake' ) {
3568
3569 # Fallen off the end already.
3570 if (!$DB::term) {
3571 DB::setterm();
3572 }
3573
3574 DB::print_help(<<EOP);
3575Debugged program terminated. Use B<q> to quit or B<R> to restart,
3576use B<o> I<inhibit_exit> to avoid stopping after program termination,
3577B<h q>, B<h R> or B<h o> to get additional info.
3578EOP
3579
3580 # Set the DB::eval context appropriately.
3581 $DB::package = 'main';
3582 $DB::usercontext = DB::_calc_usercontext($DB::package);
3583 } ## end elsif ($package eq 'DB::fake')
3584
3585=pod
3586
3587If the program hasn't finished executing, we scan forward to the
3588next executable line, print that out, build the prompt from the file and line
3589number information, and print that.
3590
3591=cut
3592
3593 else {
3594
3595
3596 # Still somewhere in the midst of execution. Set up the
3597 # debugger prompt.
3598 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3599 # Perl 5 ones (sorry, we don't print Klingon
3600 #module names)
3601
3602 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3603 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3604 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3605
3606 # Break up the prompt if it's really long.
3607 if ( length($self->prefix()) > 30 ) {
44a07e3e 3608 $self->position($self->prefix . "$DB::line):\n$DB::line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3609 $self->prefix("");
3610 $self->infix(":\t"