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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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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
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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.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
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
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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
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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>,
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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<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> 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
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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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
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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<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($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
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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
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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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
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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
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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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
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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
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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
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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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
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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$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
ef18ae63 189The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
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190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
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193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
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200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
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204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
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214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
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218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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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
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227ReadLine applications.
228
b570d64b 229=item * NonStop
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230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
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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
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239
240host:port to connect to on remote host for remote debugging.
241
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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
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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>!)
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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
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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
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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.
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308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
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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.
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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).
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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
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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
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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
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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
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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
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375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
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377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
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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}}> ,
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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
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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
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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.
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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>).
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486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
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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
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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.
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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
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511package DB;
512
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513use strict;
514
2dbd01ad 515BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 516
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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:
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524use vars qw($VERSION $header);
525
931d9438 526$VERSION = '1.39_05';
69893cff 527
e22ea7cc 528$header = "perl5db.pl version $VERSION";
d338d6fe 529
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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
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538C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
539
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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>.
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546
547Next we need to handle C<$@> without getting confused. We save C<$@> in a
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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
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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
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556(the "watch expressions" code does this to get the value of the watch
557expression but not show it unless it matters).
558
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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
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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.
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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
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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
6b24a4b7 638 $filename
6b24a4b7
SF
639 $hist
640 $histfile
641 $histsize
6b24a4b7
SF
642 $IN
643 $inhibit_exit
644 @ini_INC
645 $ini_warn
6b24a4b7
SF
646 $maxtrace
647 $od
6b24a4b7
SF
648 $onetimedumpDepth
649 %option
650 @options
651 $osingle
652 $otrace
6b24a4b7
SF
653 $packname
654 $pager
655 $post
656 %postponed
657 $prc
658 $pre
659 $pretype
660 $psh
661 @RememberOnROptions
662 $remoteport
663 @res
664 $rl
665 @saved
6b24a4b7 666 $signalLevel
6b24a4b7
SF
667 $start
668 $sub
669 %sub
670 $subname
671 $term
6b24a4b7
SF
672 $usercontext
673 $warnLevel
674 $window
675);
676
0b83f3d9
SF
677our (
678 $evalarg,
679 $frame,
680 $ImmediateStop,
681 $line,
682 $onetimeDump,
683 $OUT,
684 $signal,
685 $single,
686 $trace,
18b5b545 687);
931ac036 688
6b24a4b7
SF
689# Used to save @ARGV and extract any debugger-related flags.
690use vars qw(@ARGS);
691
692# Used to prevent multiple entries to diesignal()
693# (if for instance diesignal() itself dies)
694use vars qw($panic);
695
696# Used to prevent the debugger from running nonstop
697# after a restart
ebd0282e 698our ($second_time);
6b24a4b7
SF
699
700sub _calc_usercontext {
701 my ($package) = @_;
702
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
706 . "package $package;"; # this won't let them modify, alas
707}
708
c1051fcf 709sub eval {
69893cff 710
c1051fcf 711 # 'my' would make it visible from user code
e22ea7cc 712 # but so does local! --tchrist
69893cff 713 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
714 local @res;
715 {
e22ea7cc
RF
716
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
69893cff
RGS
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
e22ea7cc 722 local $otrace = $trace;
69893cff
RGS
723 local $osingle = $single;
724 local $od = $^D;
725
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
728
e22ea7cc 729 # $usercontext built in DB::DB near the comment
69893cff
RGS
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
e22ea7cc 732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
733
734 # Restore those old values.
735 $trace = $otrace;
736 $single = $osingle;
737 $^D = $od;
c1051fcf 738 }
69893cff
RGS
739
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
c1051fcf 742 my $at = $@;
69893cff
RGS
743
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
e22ea7cc 746 local $saved[0]; # Preserve the old value of $@
7c54f46a 747 eval { DB::save() };
69893cff
RGS
748
749 # Now see whether we need to report an error back to the user.
c1051fcf 750 if ($at) {
69893cff
RGS
751 local $\ = '';
752 print $OUT $at;
753 }
754
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
e22ea7cc
RF
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
762 }
763 elsif ( $onetimeDump eq 'methods' ) {
764 methods( $res[0] );
765 }
69893cff 766 } ## end elsif ($onetimeDump)
c1051fcf 767 @res;
69893cff
RGS
768} ## end sub eval
769
770############################################## End lexical danger zone
c1051fcf 771
e22ea7cc
RF
772# After this point it is safe to introduce lexicals.
773# The code being debugged will be executing in its own context, and
69893cff 774# can't see the inside of the debugger.
d338d6fe 775#
e22ea7cc 776# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
777# possible. If you make something a lexical, it's not going to be addressable
778# from outside the debugger even if you know its name.
779
d338d6fe
PP
780# This file is automatically included if you do perl -d.
781# It's probably not useful to include this yourself.
782#
e22ea7cc 783# Before venturing further into these twisty passages, it is
2f7e9187
MS
784# wise to read the perldebguts man page or risk the ire of dragons.
785#
69893cff
RGS
786# (It should be noted that perldebguts will tell you a lot about
787# the underlying mechanics of how the debugger interfaces into the
788# Perl interpreter, but not a lot about the debugger itself. The new
789# comments in this code try to address this problem.)
790
d338d6fe 791# Note that no subroutine call is possible until &DB::sub is defined
36477c24 792# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 793# true if $deep is not defined.
055fd3a9
GS
794
795# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
796
797# modified Perl debugger, to be run from Emacs in perldb-mode
798# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799# Johan Vromans -- upgrade to 4.0 pl 10
800# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 801########################################################################
d338d6fe 802
69893cff
RGS
803=head1 DEBUGGER INITIALIZATION
804
805The debugger starts up in phases.
806
807=head2 BASIC SETUP
808
809First, it initializes the environment it wants to run in: turning off
810warnings during its own compilation, defining variables which it will need
811to avoid warnings later, setting itself up to not exit when the program
812terminates, and defaulting to printing return values for the C<r> command.
813
814=cut
815
eda6e075 816# Needed for the statement after exec():
69893cff
RGS
817#
818# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 819# compilation. Probably it would be better practice to fix the warnings,
69893cff 820# but this is how it's done at the moment.
eda6e075 821
e22ea7cc
RF
822BEGIN {
823 $ini_warn = $^W;
824 $^W = 0;
825} # Switch compilation warnings off until another BEGIN.
d12a4851 826
69893cff
RGS
827local ($^W) = 0; # Switch run-time warnings off during init.
828
2cbb2ee1
RGS
829=head2 THREADS SUPPORT
830
831If we are running under a threaded Perl, we require threads and threads::shared
832if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833threaded debugger control. C<-dt> can also be used to set this.
834
835Each new thread will be announced and the debugger prompt will always inform
836you of each new thread created. It will also indicate the thread id in which
837we are currently running within the prompt like this:
838
2dbd01ad 839 [tid] DB<$i>
2cbb2ee1
RGS
840
841Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842command prompt. The prompt will show: C<[0]> when running under threads, but
843not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
844
845While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 846will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
847in a currently executing thread, you will stay there until it completes. With
848the current implementation it is not currently possible to hop from one thread
849to another.
850
851The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
852
853Note that threading support was built into the debugger as of Perl version
854C<5.8.6> and debugger version C<1.2.8>.
855
856=cut
857
858BEGIN {
2dbd01ad
SF
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
861 require threads;
862 require threads::shared;
863 import threads::shared qw(share);
864 $DBGR;
865 share(\$DBGR);
866 lock($DBGR);
867 print "Threads support enabled\n";
868 } else {
869 *lock = sub(*) {};
870 *share = sub(*) {};
871 }
2cbb2ee1
RGS
872}
873
2218c045
SF
874# These variables control the execution of 'dumpvar.pl'.
875{
876 package dumpvar;
877 use vars qw(
878 $hashDepth
879 $arrayDepth
880 $dumpDBFiles
881 $dumpPackages
882 $quoteHighBit
883 $printUndef
884 $globPrint
885 $usageOnly
886 );
887}
69893cff 888
2218c045
SF
889# used to control die() reporting in diesignal()
890{
891 package Carp;
892 use vars qw($CarpLevel);
893}
d338d6fe 894
422c59bf 895# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 896foreach my $k (keys (%INC)) {
2dbd01ad 897 share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
898};
899
54d04a52 900# Command-line + PERLLIB:
69893cff 901# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
902@ini_INC = @INC;
903
69893cff
RGS
904# This was an attempt to clear out the previous values of various
905# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
906# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
907
69893cff
RGS
908# We set these variables to safe values. We don't want to blindly turn
909# off warnings, because other packages may still want them.
e22ea7cc
RF
910$trace = $signal = $single = 0; # Uninitialized warning suppression
911 # (local $^W cannot help - other packages!).
69893cff
RGS
912
913# Default to not exiting when program finishes; print the return
914# value when the 'r' command is used to return from a subroutine.
55497cff 915$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 916
6b24a4b7
SF
917use vars qw($trace_to_depth);
918
5e2b42dd
SF
919# Default to 1E9 so it won't be limited to a certain recursion depth.
920$trace_to_depth = 1E9;
bdba49ad 921
69893cff
RGS
922=head1 OPTION PROCESSING
923
b570d64b
SF
924The debugger's options are actually spread out over the debugger itself and
925C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
926subs to be called with a value. To try to make this a little easier to
927manage, the debugger uses a few data structures to define what options
928are legal and how they are to be processed.
929
930First, the C<@options> array defines the I<names> of all the options that
931are to be accepted.
932
933=cut
934
935@options = qw(
5561b870 936 CommandSet HistFile HistSize
e22ea7cc
RF
937 hashDepth arrayDepth dumpDepth
938 DumpDBFiles DumpPackages DumpReused
939 compactDump veryCompact quote
940 HighBit undefPrint globPrint
941 PrintRet UsageOnly frame
942 AutoTrace TTY noTTY
943 ReadLine NonStop LineInfo
944 maxTraceLen recallCommand ShellBang
945 pager tkRunning ornaments
946 signalLevel warnLevel dieLevel
947 inhibit_exit ImmediateStop bareStringify
948 CreateTTY RemotePort windowSize
584420f0 949 DollarCaretP
e22ea7cc 950);
d12a4851 951
584420f0 952@RememberOnROptions = qw(DollarCaretP);
d12a4851 953
69893cff
RGS
954=pod
955
956Second, C<optionVars> lists the variables that each option uses to save its
957state.
958
959=cut
960
6b24a4b7
SF
961use vars qw(%optionVars);
962
69893cff 963%optionVars = (
e22ea7cc
RF
964 hashDepth => \$dumpvar::hashDepth,
965 arrayDepth => \$dumpvar::arrayDepth,
966 CommandSet => \$CommandSet,
967 DumpDBFiles => \$dumpvar::dumpDBFiles,
968 DumpPackages => \$dumpvar::dumpPackages,
969 DumpReused => \$dumpvar::dumpReused,
970 HighBit => \$dumpvar::quoteHighBit,
971 undefPrint => \$dumpvar::printUndef,
972 globPrint => \$dumpvar::globPrint,
973 UsageOnly => \$dumpvar::usageOnly,
974 CreateTTY => \$CreateTTY,
975 bareStringify => \$dumpvar::bareStringify,
976 frame => \$frame,
977 AutoTrace => \$trace,
978 inhibit_exit => \$inhibit_exit,
979 maxTraceLen => \$maxtrace,
980 ImmediateStop => \$ImmediateStop,
981 RemotePort => \$remoteport,
982 windowSize => \$window,
5561b870
AK
983 HistFile => \$histfile,
984 HistSize => \$histsize,
69893cff
RGS
985);
986
987=pod
988
989Third, C<%optionAction> defines the subroutine to be called to process each
990option.
991
b570d64b 992=cut
69893cff 993
6b24a4b7
SF
994use vars qw(%optionAction);
995
69893cff
RGS
996%optionAction = (
997 compactDump => \&dumpvar::compactDump,
998 veryCompact => \&dumpvar::veryCompact,
999 quote => \&dumpvar::quote,
1000 TTY => \&TTY,
1001 noTTY => \&noTTY,
1002 ReadLine => \&ReadLine,
1003 NonStop => \&NonStop,
1004 LineInfo => \&LineInfo,
1005 recallCommand => \&recallCommand,
1006 ShellBang => \&shellBang,
1007 pager => \&pager,
1008 signalLevel => \&signalLevel,
1009 warnLevel => \&warnLevel,
1010 dieLevel => \&dieLevel,
1011 tkRunning => \&tkRunning,
1012 ornaments => \&ornaments,
1013 RemotePort => \&RemotePort,
1014 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1015);
1016
69893cff
RGS
1017=pod
1018
1019Last, the C<%optionRequire> notes modules that must be C<require>d if an
1020option is used.
1021
1022=cut
d338d6fe 1023
69893cff
RGS
1024# Note that this list is not complete: several options not listed here
1025# actually require that dumpvar.pl be loaded for them to work, but are
1026# not in the table. A subsequent patch will correct this problem; for
1027# the moment, we're just recommenting, and we are NOT going to change
1028# function.
6b24a4b7
SF
1029use vars qw(%optionRequire);
1030
eda6e075 1031%optionRequire = (
69893cff
RGS
1032 compactDump => 'dumpvar.pl',
1033 veryCompact => 'dumpvar.pl',
1034 quote => 'dumpvar.pl',
e22ea7cc 1035);
69893cff
RGS
1036
1037=pod
1038
1039There are a number of initialization-related variables which can be set
1040by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1041variable. These are:
1042
1043=over 4
1044
1045=item C<$rl> - readline control XXX needs more explanation
1046
1047=item C<$warnLevel> - whether or not debugger takes over warning handling
1048
1049=item C<$dieLevel> - whether or not debugger takes over die handling
1050
1051=item C<$signalLevel> - whether or not debugger takes over signal handling
1052
1053=item C<$pre> - preprompt actions (array reference)
1054
1055=item C<$post> - postprompt actions (array reference)
1056
1057=item C<$pretype>
1058
1059=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1060
1061=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1062
1063=back
1064
1065=cut
d338d6fe
PP
1066
1067# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1068$rl = 1 unless defined $rl;
1069$warnLevel = 1 unless defined $warnLevel;
1070$dieLevel = 1 unless defined $dieLevel;
1071$signalLevel = 1 unless defined $signalLevel;
1072$pre = [] unless defined $pre;
1073$post = [] unless defined $post;
1074$pretype = [] unless defined $pretype;
1075$CreateTTY = 3 unless defined $CreateTTY;
1076$CommandSet = '580' unless defined $CommandSet;
1077
2cbb2ee1
RGS
1078share($rl);
1079share($warnLevel);
1080share($dieLevel);
1081share($signalLevel);
1082share($pre);
1083share($post);
1084share($pretype);
1085share($rl);
1086share($CreateTTY);
1087share($CommandSet);
1088
69893cff
RGS
1089=pod
1090
1091The default C<die>, C<warn>, and C<signal> handlers are set up.
1092
1093=cut
055fd3a9 1094
d338d6fe
PP
1095warnLevel($warnLevel);
1096dieLevel($dieLevel);
1097signalLevel($signalLevel);
055fd3a9 1098
69893cff
RGS
1099=pod
1100
1101The pager to be used is needed next. We try to get it from the
5561b870 1102environment first. If it's not defined there, we try to find it in
69893cff
RGS
1103the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1104then call the C<pager()> function to save the pager name.
1105
1106=cut
1107
1108# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1109pager(
e22ea7cc 1110
69893cff 1111 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1112 defined $ENV{PAGER}
1113 ? $ENV{PAGER}
69893cff
RGS
1114
1115 # If not, see if Config.pm defines it.
e22ea7cc
RF
1116 : eval { require Config }
1117 && defined $Config::Config{pager}
1118 ? $Config::Config{pager}
69893cff
RGS
1119
1120 # If not, fall back to 'more'.
e22ea7cc
RF
1121 : 'more'
1122 )
1123 unless defined $pager;
69893cff
RGS
1124
1125=pod
1126
1127We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1128recall character (C<!> unless otherwise defined) and the shell escape
1129character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1130neither works in the debugger at the moment.
1131
1132=cut
1133
055fd3a9 1134setman();
69893cff
RGS
1135
1136# Set up defaults for command recall and shell escape (note:
1137# these currently don't work in linemode debugging).
2218c045
SF
1138recallCommand("!") unless defined $prc;
1139shellBang("!") unless defined $psh;
69893cff
RGS
1140
1141=pod
1142
1143We then set up the gigantic string containing the debugger help.
1144We also set the limit on the number of arguments we'll display during a
1145trace.
1146
1147=cut
1148
04e43a21 1149sethelp();
69893cff
RGS
1150
1151# If we didn't get a default for the length of eval/stack trace args,
1152# set it here.
1d06cb2d 1153$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1154
1155=head2 SETTING UP THE DEBUGGER GREETING
1156
be9a9b1d 1157The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1158running, and whether the current debugger is the primary or a child.
1159
1160If we are the primary, we just hang onto our pid so we'll have it when
1161or if we start a child debugger. If we are a child, we'll set things up
1162so we'll have a unique greeting and so the parent will give us our own
1163TTY later.
1164
1165We save the current contents of the C<PERLDB_PIDS> environment variable
1166because we mess around with it. We'll also need to hang onto it because
1167we'll need it if we restart.
1168
1169Child debuggers make a label out of the current PID structure recorded in
1170PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1171yet so the parent will give them one later via C<resetterm()>.
1172
1173=cut
1174
e22ea7cc 1175# Save the current contents of the environment; we're about to
69893cff 1176# much with it. We'll need this if we have to restart.
6b24a4b7 1177use vars qw($ini_pids);
f1583d8f 1178$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1179
6b24a4b7
SF
1180use vars qw ($pids $term_pid);
1181
e22ea7cc
RF
1182if ( defined $ENV{PERLDB_PIDS} ) {
1183
69893cff 1184 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1185 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1186 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1187
1188 my $env_pids = $ENV{PERLDB_PIDS};
1189 $pids = "[$env_pids]";
1190
1191 # Unless we are on OpenVMS, all programs under the DCL shell run under
1192 # the same PID.
1193
1194 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $term_pid = $$;
1196 }
1197 else {
1198 $ENV{PERLDB_PIDS} .= "->$$";
1199 $term_pid = -1;
1200 }
1201
69893cff
RGS
1202} ## end if (defined $ENV{PERLDB_PIDS...
1203else {
e22ea7cc
RF
1204
1205 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1206 # child debugger, and mark us as the parent, so we'll know to set up
1207 # more TTY's is we have to.
1208 $ENV{PERLDB_PIDS} = "$$";
619a0444 1209 $pids = "[pid=$$]";
e22ea7cc 1210 $term_pid = $$;
f1583d8f 1211}
69893cff 1212
6b24a4b7 1213use vars qw($pidprompt);
f1583d8f 1214$pidprompt = '';
69893cff
RGS
1215
1216# Sets up $emacs as a synonym for $slave_editor.
6b24a4b7 1217use vars qw($slave_editor);
69893cff
RGS
1218*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1219
1220=head2 READING THE RC FILE
1221
b570d64b 1222The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1223running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224
b570d64b 1225=cut
69893cff
RGS
1226
1227# As noted, this test really doesn't check accurately that the debugger
1228# is running at a terminal or not.
d338d6fe 1229
6b24a4b7 1230use vars qw($rcfile);
fb4d8a6c
SF
1231{
1232 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1233 # this is the wrong metric!
1234 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1235}
1236
69893cff
RGS
1237=pod
1238
1239The debugger does a safety test of the file to be read. It must be owned
1240either by the current user or root, and must only be writable by the owner.
1241
1242=cut
1243
1244# This wraps a safety test around "do" to read and evaluate the init file.
1245#
055fd3a9
GS
1246# This isn't really safe, because there's a race
1247# between checking and opening. The solution is to
1248# open and fstat the handle, but then you have to read and
1249# eval the contents. But then the silly thing gets
69893cff
RGS
1250# your lexical scope, which is unfortunate at best.
1251sub safe_do {
055fd3a9
GS
1252 my $file = shift;
1253
1254 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1255 local $SIG{__WARN__};
1256 local $SIG{__DIE__};
055fd3a9 1257
e22ea7cc 1258 unless ( is_safe_file($file) ) {
69893cff 1259 CORE::warn <<EO_GRIPE;
055fd3a9 1260perldb: Must not source insecure rcfile $file.
b570d64b 1261 You or the superuser must be the owner, and it must not
69893cff 1262 be writable by anyone but its owner.
055fd3a9 1263EO_GRIPE
69893cff
RGS
1264 return;
1265 } ## end unless (is_safe_file($file...
055fd3a9
GS
1266
1267 do $file;
1268 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1269} ## end sub safe_do
055fd3a9 1270
69893cff
RGS
1271# This is the safety test itself.
1272#
055fd3a9
GS
1273# Verifies that owner is either real user or superuser and that no
1274# one but owner may write to it. This function is of limited use
1275# when called on a path instead of upon a handle, because there are
1276# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1277# eventually accessed is the same as the one tested.
055fd3a9
GS
1278# Assumes that the file's existence is not in doubt.
1279sub is_safe_file {
1280 my $path = shift;
69893cff 1281 stat($path) || return; # mysteriously vaporized
e22ea7cc 1282 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1283
1284 return 0 if $uid != 0 && $uid != $<;
1285 return 0 if $mode & 022;
1286 return 1;
69893cff 1287} ## end sub is_safe_file
055fd3a9 1288
69893cff 1289# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1290# exists, we safely do it.
1291if ( -f $rcfile ) {
055fd3a9 1292 safe_do("./$rcfile");
69893cff 1293}
e22ea7cc 1294
69893cff 1295# If there isn't one here, try the user's home directory.
e22ea7cc 1296elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1297 safe_do("$ENV{HOME}/$rcfile");
1298}
e22ea7cc 1299
69893cff 1300# Else try the login directory.
e22ea7cc 1301elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1302 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1303}
1304
69893cff 1305# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1306if ( defined $ENV{PERLDB_OPTS} ) {
1307 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1308}
1309
69893cff
RGS
1310=pod
1311
1312The last thing we do during initialization is determine which subroutine is
1313to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1314the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1315(darwin).
69893cff
RGS
1316
1317=cut
1318
1319# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1320# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1321# OS/2, or on Mac OS X. This may need some expansion.
1322
1323if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1324{
b570d64b 1325 if ( defined $remoteport ) {
11653f7f
JJ
1326 # Expect an inetd-like server
1327 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1328 }
1329 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1330 # of terminal this is,
1331 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1332 and defined $ENV{DISPLAY} # and what display it's on,
1333 )
1334 {
1335 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1336 }
1337 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1338 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1339 }
1340 elsif ( $^O eq 'darwin' # If this is Mac OS X
1341 and defined $ENV{TERM_PROGRAM} # and we're running inside
1342 and $ENV{TERM_PROGRAM}
1343 eq 'Apple_Terminal' # Terminal.app
1344 )
1345 {
1346 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1347 }
69893cff 1348} ## end if (not defined &get_fork_TTY...
e22ea7cc 1349
dbb46cec
DQ
1350# untaint $^O, which may have been tainted by the last statement.
1351# see bug [perl #24674]
e22ea7cc
RF
1352$^O =~ m/^(.*)\z/;
1353$^O = $1;
f1583d8f 1354
d12a4851 1355# Here begin the unreadable code. It needs fixing.
055fd3a9 1356
69893cff
RGS
1357=head2 RESTART PROCESSING
1358
1359This section handles the restart command. When the C<R> command is invoked, it
1360tries to capture all of the state it can into environment variables, and
1361then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1362if C<PERLDB_RESTART> is there; if so, we reload all the information that
1363the R command stuffed into the environment variables.
1364
b570d64b 1365 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1366 PERLDB_HIST - command history, if it's available
1367 PERLDB_ON_LOAD - breakpoints set by the rc file
1368 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1369 PERLDB_VISITED - files that had breakpoints
1370 PERLDB_FILE_... - breakpoints for a file
1371 PERLDB_OPT - active options
1372 PERLDB_INC - the original @INC
1373 PERLDB_PRETYPE - preprompt debugger actions
1374 PERLDB_PRE - preprompt Perl code
1375 PERLDB_POST - post-prompt Perl code
1376 PERLDB_TYPEAHEAD - typeahead captured by readline()
1377
1378We chug through all these variables and plug the values saved in them
1379back into the appropriate spots in the debugger.
1380
1381=cut
1382
6b24a4b7
SF
1383use vars qw(@hist @truehist %postponed_file @typeahead);
1384
fb0fb5f4
SF
1385sub _restore_shared_globals_after_restart
1386{
1387 @hist = get_list('PERLDB_HIST');
1388 %break_on_load = get_list("PERLDB_ON_LOAD");
1389 %postponed = get_list("PERLDB_POSTPONE");
1390
1391 share(@hist);
1392 share(@truehist);
1393 share(%break_on_load);
1394 share(%postponed);
1395}
1396
e18a02a6 1397sub _restore_breakpoints_and_actions {
e22ea7cc 1398
e22ea7cc 1399 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1400
bdba49ad
SF
1401 for my $file_idx ( 0 .. $#had_breakpoints ) {
1402 my $filename = $had_breakpoints[$file_idx];
1403 my %pf = get_list("PERLDB_FILE_$file_idx");
1404 $postponed_file{ $filename } = \%pf if %pf;
1405 my @lines = sort {$a <=> $b} keys(%pf);
1406 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1407 for my $line_idx (0 .. $#lines) {
1408 _set_breakpoint_enabled_status(
1409 $filename,
1410 $lines[$line_idx],
1411 ($enabled_statuses[$line_idx] ? 1 : ''),
1412 );
1413 }
e22ea7cc 1414 }
69893cff 1415
e18a02a6
SF
1416 return;
1417}
1418
ca50076b
SF
1419sub _restore_options_after_restart
1420{
1421 my %options_map = get_list("PERLDB_OPT");
1422
1423 while ( my ( $opt, $val ) = each %options_map ) {
1424 $val =~ s/[\\\']/\\$1/g;
1425 parse_options("$opt'$val'");
1426 }
1427
1428 return;
1429}
1430
18580168
SF
1431sub _restore_globals_after_restart
1432{
1433 # restore original @INC
1434 @INC = get_list("PERLDB_INC");
1435 @ini_INC = @INC;
1436
1437 # return pre/postprompt actions and typeahead buffer
1438 $pretype = [ get_list("PERLDB_PRETYPE") ];
1439 $pre = [ get_list("PERLDB_PRE") ];
1440 $post = [ get_list("PERLDB_POST") ];
1441 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1442
1443 return;
1444}
1445
fb0fb5f4 1446
e18a02a6
SF
1447if ( exists $ENV{PERLDB_RESTART} ) {
1448
1449 # We're restarting, so we don't need the flag that says to restart anymore.
1450 delete $ENV{PERLDB_RESTART};
1451
1452 # $restart = 1;
fb0fb5f4 1453 _restore_shared_globals_after_restart();
e18a02a6
SF
1454
1455 _restore_breakpoints_and_actions();
1456
69893cff 1457 # restore options
ca50076b 1458 _restore_options_after_restart();
69893cff 1459
18580168 1460 _restore_globals_after_restart();
69893cff
RGS
1461} ## end if (exists $ENV{PERLDB_RESTART...
1462
1463=head2 SETTING UP THE TERMINAL
1464
1465Now, we'll decide how the debugger is going to interact with the user.
1466If there's no TTY, we set the debugger to run non-stop; there's not going
1467to be anyone there to enter commands.
1468
1469=cut
54d04a52 1470
ebd0282e 1471use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1472use vars qw($lineinfo $doccmd);
1473
ebd0282e
SF
1474our ($runnonstop);
1475
d338d6fe 1476if ($notty) {
69893cff 1477 $runnonstop = 1;
2dbd01ad 1478 share($runnonstop);
69893cff 1479}
d12a4851 1480
69893cff
RGS
1481=pod
1482
1483If there is a TTY, we have to determine who it belongs to before we can
1484proceed. If this is a slave editor or graphical debugger (denoted by
1485the first command-line switch being '-emacs'), we shift this off and
1486set C<$rl> to 0 (XXX ostensibly to do straight reads).
1487
1488=cut
1489
1490else {
e22ea7cc 1491
69893cff
RGS
1492 # Is Perl being run from a slave editor or graphical debugger?
1493 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1494 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1495 $rl = 0;
1496 shift(@main::ARGV);
1497 }
e22ea7cc
RF
1498
1499 #require Term::ReadLine;
d12a4851 1500
69893cff
RGS
1501=pod
1502
1503We then determine what the console should be on various systems:
1504
1505=over 4
1506
1507=item * Cygwin - We use C<stdin> instead of a separate device.
1508
1509=cut
1510
e22ea7cc
RF
1511 if ( $^O eq 'cygwin' ) {
1512
69893cff
RGS
1513 # /dev/tty is binary. use stdin for textmode
1514 undef $console;
1515 }
1516
1517=item * Unix - use C</dev/tty>.
1518
1519=cut
1520
e22ea7cc 1521 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1522 $console = "/dev/tty";
1523 }
1524
1525=item * Windows or MSDOS - use C<con>.
1526
1527=cut
1528
e22ea7cc 1529 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1530 $console = "con";
1531 }
1532
69893cff
RGS
1533=item * VMS - use C<sys$command>.
1534
1535=cut
1536
1537 else {
e22ea7cc 1538
69893cff
RGS
1539 # everything else is ...
1540 $console = "sys\$command";
d12a4851 1541 }
69893cff
RGS
1542
1543=pod
1544
1545=back
1546
1547Several other systems don't use a specific console. We C<undef $console>
1548for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1549with a slave editor, Epoc).
1550
1551=cut
d12a4851 1552
e22ea7cc
RF
1553 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1554
69893cff 1555 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1556 $console = undef;
1557 }
1558
1559 if ( $^O eq 'NetWare' ) {
d12a4851 1560
69893cff
RGS
1561 # /dev/tty is binary. use stdin for textmode
1562 $console = undef;
1563 }
d12a4851 1564
69893cff
RGS
1565 # In OS/2, we need to use STDIN to get textmode too, even though
1566 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1567 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1568 { # In OS/2
1569 $console = undef;
1570 }
1571
1572 # EPOC also falls into the 'got to use STDIN' camp.
1573 if ( $^O eq 'epoc' ) {
1574 $console = undef;
1575 }
d12a4851 1576
69893cff
RGS
1577=pod
1578
1579If there is a TTY hanging around from a parent, we use that as the console.
1580
1581=cut
1582
e22ea7cc 1583 $console = $tty if defined $tty;
d12a4851 1584
b570d64b 1585=head2 SOCKET HANDLING
69893cff
RGS
1586
1587The debugger is capable of opening a socket and carrying out a debugging
1588session over the socket.
1589
1590If C<RemotePort> was defined in the options, the debugger assumes that it
1591should try to start a debugging session on that port. It builds the socket
1592and then tries to connect the input and output filehandles to it.
1593
1594=cut
1595
1596 # Handle socket stuff.
e22ea7cc
RF
1597
1598 if ( defined $remoteport ) {
1599
69893cff
RGS
1600 # If RemotePort was defined in the options, connect input and output
1601 # to the socket.
11653f7f 1602 $IN = $OUT = connect_remoteport();
69893cff
RGS
1603 } ## end if (defined $remoteport)
1604
1605=pod
1606
1607If no C<RemotePort> was defined, and we want to create a TTY on startup,
1608this is probably a situation where multiple debuggers are running (for example,
1609a backticked command that starts up another debugger). We create a new IN and
1610OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1611and if we can.
1612
1613=cut
1614
1615 # Non-socket.
1616 else {
e22ea7cc 1617
69893cff
RGS
1618 # Two debuggers running (probably a system or a backtick that invokes
1619 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1620 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1621 # know how, and we can.
e22ea7cc
RF
1622 create_IN_OUT(4) if $CreateTTY & 4;
1623 if ($console) {
1624
69893cff 1625 # If we have a console, check to see if there are separate ins and
cd1191f1 1626 # outs to open. (They are assumed identical if not.)
69893cff 1627
e22ea7cc
RF
1628 my ( $i, $o ) = split /,/, $console;
1629 $o = $i unless defined $o;
69893cff 1630
69893cff 1631 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1632 open( IN, "+<$i" )
1633 || open( IN, "<$i" )
1634 || open( IN, "<&STDIN" );
1635
69893cff
RGS
1636 # read/write/create/clobber out, or write/create/clobber out,
1637 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1638 open( OUT, "+>$o" )
1639 || open( OUT, ">$o" )
1640 || open( OUT, ">&STDERR" )
1641 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1642
1643 } ## end if ($console)
1644 elsif ( not defined $console ) {
1645
1646 # No console. Open STDIN.
1647 open( IN, "<&STDIN" );
1648
1649 # merge with STDERR, or with STDOUT.
1650 open( OUT, ">&STDERR" )
1651 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1652 $console = 'STDIN/OUT';
69893cff
RGS
1653 } ## end elsif (not defined $console)
1654
1655 # Keep copies of the filehandles so that when the pager runs, it
1656 # can close standard input without clobbering ours.
2b0b9dd1
SF
1657 if ($console or (not defined($console))) {
1658 $IN = \*IN;
1659 $OUT = \*OUT;
1660 }
e22ea7cc
RF
1661 } ## end elsif (from if(defined $remoteport))
1662
1663 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1664 $OUT->autoflush(1);
e22ea7cc
RF
1665
1666 # Line info goes to debugger output unless pointed elsewhere.
1667 # Pointing elsewhere makes it possible for slave editors to
1668 # keep track of file and position. We have both a filehandle
1669 # and a I/O description to keep track of.
1670 $LINEINFO = $OUT unless defined $LINEINFO;
1671 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1672 # share($LINEINFO); # <- unable to share globs
1673 share($lineinfo); #
e22ea7cc 1674
69893cff
RGS
1675=pod
1676
1677To finish initialization, we show the debugger greeting,
1678and then call the C<afterinit()> subroutine if there is one.
1679
1680=cut
d12a4851 1681
e22ea7cc
RF
1682 # Show the debugger greeting.
1683 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1684 unless ($runnonstop) {
1685 local $\ = '';
1686 local $, = '';
1687 if ( $term_pid eq '-1' ) {
1688 print $OUT "\nDaughter DB session started...\n";
1689 }
1690 else {
1691 print $OUT "\nLoading DB routines from $header\n";
1692 print $OUT (
1693 "Editor support ",
1694 $slave_editor ? "enabled" : "available", ".\n"
1695 );
1696 print $OUT
1f874cb6 1697"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1698 } ## end else [ if ($term_pid eq '-1')
1699 } ## end unless ($runnonstop)
1700} ## end else [ if ($notty)
1701
1702# XXX This looks like a bug to me.
1703# Why copy to @ARGS and then futz with @args?
d338d6fe 1704@ARGS = @ARGV;
6b24a4b7 1705# for (@args) {
69893cff
RGS
1706 # Make sure backslashes before single quotes are stripped out, and
1707 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1708 # s/\'/\\\'/g; # removed while not justified understandably
1709 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1710# }
d338d6fe 1711
e22ea7cc 1712# If there was an afterinit() sub defined, call it. It will get
69893cff 1713# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1714if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1715 afterinit();
d338d6fe 1716}
e22ea7cc 1717
69893cff 1718# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1719use vars qw($I_m_init);
1720
43aed9ee
IZ
1721$I_m_init = 1;
1722
d338d6fe
PP
1723############################################################ Subroutines
1724
69893cff
RGS
1725=head1 SUBROUTINES
1726
1727=head2 DB
1728
1729This gigantic subroutine is the heart of the debugger. Called before every
1730statement, its job is to determine if a breakpoint has been reached, and
1731stop if so; read commands from the user, parse them, and execute
b468dcb6 1732them, and then send execution off to the next statement.
69893cff
RGS
1733
1734Note that the order in which the commands are processed is very important;
1735some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1736to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1737but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1738see what's happening in any given command.
1739
1740=cut
1741
6b24a4b7
SF
1742use vars qw(
1743 $action
1744 %alias
1745 $cmd
1746 $doret
1747 $fall_off_end
1748 $file
1749 $filename_ini
1750 $finished
1751 %had_breakpoints
1752 $incr
1753 $laststep
1754 $level
1755 $max
6b24a4b7
SF
1756 $package
1757 $rc
1758 $sh
6b24a4b7 1759 $try
2c247e84 1760 $end
6b24a4b7
SF
1761);
1762
8ad70697
SF
1763our ( $stack_depth, @stack, @to_watch, @old_watch, );
1764
6791e41b
SF
1765sub _DB__determine_if_we_should_break
1766{
1767 # if we have something here, see if we should break.
1768 # $stop is lexical and local to this block - $action on the other hand
1769 # is global.
1770 my $stop;
1771
1772 if ( $dbline{$line}
1773 && _is_breakpoint_enabled($filename, $line)
1774 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1775 {
1776
1777 # Stop if the stop criterion says to just stop.
1778 if ( $stop eq '1' ) {
1779 $signal |= 1;
1780 }
1781
1782 # It's a conditional stop; eval it in the user's context and
1783 # see if we should stop. If so, remove the one-time sigil.
1784 elsif ($stop) {
1785 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1786 &eval;
1787 # If the breakpoint is temporary, then delete its enabled status.
1788 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1789 _cancel_breakpoint_temp_enabled_status($filename, $line);
1790 }
1791 }
1792 } ## end if ($dbline{$line} && ...
1793}
1794
8481f647
SF
1795sub _DB__is_finished {
1796 if ($finished and $level <= 1) {
1797 end_report();
1798 return 1;
1799 }
1800 else {
1801 return;
1802 }
1803}
1804
32bbadc6
SF
1805sub _DB__read_next_cmd
1806{
1807 my ($tid) = @_;
1808
1809 # We have a terminal, or can get one ...
1810 if (!$term) {
1811 setterm();
1812 }
1813
1814 # ... and it belogs to this PID or we get one for this PID ...
1815 if ($term_pid != $$) {
1816 resetterm(1);
1817 }
1818
1819 # ... and we got a line of command input ...
1820 $cmd = DB::readline(
1821 "$pidprompt $tid DB"
1822 . ( '<' x $level )
1823 . ( $#hist + 1 )
1824 . ( '>' x $level ) . " "
1825 );
1826
1827 return defined($cmd);
1828}
1829
7013f40c
SF
1830sub _DB__trim_command_and_return_first_component {
1831 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1832 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1833
1834 $cmd =~ m{\A(\S*)};
1835 return $1;
1836}
1837
2b0b9dd1
SF
1838sub DB {
1839
1840 # lock the debugger and get the thread id for the prompt
1841 lock($DBGR);
1842 my $tid;
1843 my $position;
1844 my ($prefix, $after, $infix);
1845 my $pat;
22fc883d 1846 my $explicit_stop;
2b0b9dd1
SF
1847
1848 if ($ENV{PERL5DB_THREADED}) {
1849 $tid = eval { "[".threads->tid."]" };
1850 }
1851
22fc883d
SF
1852 my $obj = DB::Obj->new(
1853 {
1854 position => \$position,
1855 prefix => \$prefix,
1856 after => \$after,
1857 explicit_stop => \$explicit_stop,
1858 infix => \$infix,
1859 },
1860 );
1861
1862 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 1863
69893cff
RGS
1864 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1865 # The code being debugged may have altered them.
d338d6fe 1866 &save;
69893cff
RGS
1867
1868 # Since DB::DB gets called after every line, we can use caller() to
1869 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1870 # caller is returning all the extra information when called from the
69893cff 1871 # debugger.
e22ea7cc 1872 local ( $package, $filename, $line ) = caller;
6b24a4b7 1873 $filename_ini = $filename;
69893cff
RGS
1874
1875 # set up the context for DB::eval, so it can properly execute
1876 # code on behalf of the user. We add the package in so that the
1877 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1878 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1879
1880 # Create an alias to the active file magical array to simplify
1881 # the code here.
e22ea7cc 1882 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1883
69893cff 1884 # Last line in the program.
55783941 1885 $max = $#dbline;
69893cff 1886
22fc883d 1887 _DB__determine_if_we_should_break(@_);
69893cff
RGS
1888
1889 # Preserve the current stop-or-not, and see if any of the W
1890 # (watch expressions) has changed.
36477c24 1891 my $was_signal = $signal;
69893cff
RGS
1892
1893 # If we have any watch expressions ...
22fc883d 1894 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
1895
1896=head2 C<watchfunction()>
1897
1898C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1899function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1900current package, filename, and line as its parameters.
1901
b570d64b 1902The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1903debugger's context, so it has access to all of the debugger's internal
1904data structures and functions.
1905
1906C<watchfunction()> can control the debugger's actions. Any of the following
1907will cause the debugger to return control to the user's program after
1908C<watchfunction()> executes:
1909
b570d64b 1910=over 4
69893cff 1911
be9a9b1d
AT
1912=item *
1913
1914Returning a false value from the C<watchfunction()> itself.
1915
1916=item *
1917
1918Altering C<$single> to a false value.
1919
1920=item *
69893cff 1921
be9a9b1d 1922Altering C<$signal> to a false value.
69893cff 1923
be9a9b1d 1924=item *
69893cff 1925
be9a9b1d 1926Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1927check for C<watchfunction()>. This can be done with
1928
1929 $trace &= ~4;
1930
1931=back
1932
1933=cut
1934
e22ea7cc 1935 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1936 # current package, filename, and line. The function executes in
1937 # the DB:: package.
e22ea7cc
RF
1938 if ( $trace & 4 ) { # User-installed watch
1939 return
1940 if watchfunction( $package, $filename, $line )
1941 and not $single
1942 and not $was_signal
1943 and not( $trace & ~4 );
69893cff
RGS
1944 } ## end if ($trace & 4)
1945
e22ea7cc 1946 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1947 # turn off the signal now.
6027b9a3 1948 $was_signal = $signal;
69893cff
RGS
1949 $signal = 0;
1950
1951=head2 GETTING READY TO EXECUTE COMMANDS
1952
1953The debugger decides to take control if single-step mode is on, the
1954C<t> command was entered, or the user generated a signal. If the program
1955has fallen off the end, we set things up so that entering further commands
1956won't cause trouble, and we say that the program is over.
1957
1958=cut
1959
8dc67a69
SF
1960 # Make sure that we always print if asked for explicitly regardless
1961 # of $trace_to_depth .
22fc883d 1962 $explicit_stop = ($single || $was_signal);
8dc67a69 1963
69893cff
RGS
1964 # Check to see if we should grab control ($single true,
1965 # trace set appropriately, or we got a signal).
8dc67a69 1966 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 1967 $obj->_DB__grab_control(@_);
69893cff
RGS
1968 } ## end if ($single || ($trace...
1969
1970=pod
1971
1972If there's an action to be executed for the line we stopped at, execute it.
b570d64b 1973If there are any preprompt actions, execute those as well.
e219e2fb
RF
1974
1975=cut
1976
69893cff 1977 # If there's an action, do it now.
05da04df
SF
1978 if ($action) {
1979 $evalarg = $action;
1980 DB::eval();
1981 }
e219e2fb 1982
69893cff
RGS
1983 # Are we nested another level (e.g., did we evaluate a function
1984 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
1985 if ( $single || $was_signal ) {
1986
69893cff 1987 # Yes, go down a level.
e22ea7cc 1988 local $level = $level + 1;
69893cff
RGS
1989
1990 # Do any pre-prompt actions.
e22ea7cc 1991 foreach $evalarg (@$pre) {
7c54f46a 1992 DB::eval();
e22ea7cc 1993 }
69893cff
RGS
1994
1995 # Complain about too much recursion if we passed the limit.
05da04df
SF
1996 if ($single & 4) {
1997 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
1998 }
69893cff
RGS
1999
2000 # The line we're currently on. Set $incr to -1 to stay here
2001 # until we get a command that tells us to advance.
e22ea7cc
RF
2002 $start = $line;
2003 $incr = -1; # for backward motion.
69893cff
RGS
2004
2005 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2006 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2007
2008=head2 WHERE ARE WE?
2009
2010XXX Relocate this section?
2011
2012The debugger normally shows the line corresponding to the current line of
2013execution. Sometimes, though, we want to see the next line, or to move elsewhere
2014in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2015
be9a9b1d
AT
2016C<$incr> controls by how many lines the I<current> line should move forward
2017after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2018line shouldn't change.
2019
be9a9b1d 2020C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2021move forwards or backwards from when doing an C<L> or C<-> command.
2022
2023C<$max> tells the debugger where the last line of the current file is. It's
2024used to terminate loops most often.
2025
2026=head2 THE COMMAND LOOP
2027
2028Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2029in two parts:
2030
2031=over 4
2032
be9a9b1d
AT
2033=item *
2034
2035The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2036reads a command and then executes it.
2037
be9a9b1d
AT
2038=item *
2039
2040The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2041is wholly contained inside the C<CMD> block and only executes a command.
2042Used to handle commands running inside a pager.
2043
2044=back
2045
2046So why have two labels to restart the loop? Because sometimes, it's easier to
2047have a command I<generate> another command and then re-execute the loop to do
2048the new command. This is faster, but perhaps a bit more convoluted.
2049
2050=cut
2051
2052 # The big command dispatch loop. It keeps running until the
2053 # user yields up control again.
2054 #
2055 # If we have a terminal for input, and we get something back
2056 # from readline(), keep on processing.
6b24a4b7
SF
2057 my $piped;
2058 my $selected;
2059
e22ea7cc 2060 CMD:
32bbadc6 2061 while (_DB__read_next_cmd($tid))
69893cff 2062 {
e22ea7cc 2063
8380a245 2064 share($cmd);
69893cff
RGS
2065 # ... try to execute the input as debugger commands.
2066
2067 # Don't stop running.
2068 $single = 0;
2069
2070 # No signal is active.
2071 $signal = 0;
2072
2073 # Handle continued commands (ending with \):
3d7a2a93 2074 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2075 $cmd .= DB::readline(" cont: ");
e22ea7cc 2076 redo CMD;
3d7a2a93 2077 }
69893cff
RGS
2078
2079=head4 The null command
2080
be9a9b1d 2081A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2082command out of C<$laststep> (where it was recorded previously), and copy it
2083back into C<$cmd> to be executed below. If there wasn't any previous command,
2084we'll do nothing below (no command will match). If there was, we also save it
2085in the command history and fall through to allow the command parsing to pick
2086it up.
2087
2088=cut
2089
2090 # Empty input means repeat the last command.
eeb7da96
SF
2091 if ($cmd eq '') {
2092 $cmd = $laststep;
2093 }
e22ea7cc 2094 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2095 if (length($cmd) >= 2) {
2096 push( @hist, $cmd );
2097 }
e22ea7cc 2098 push( @truehist, $cmd );
2dbd01ad
SF
2099 share(@hist);
2100 share(@truehist);
e22ea7cc
RF
2101
2102 # This is a restart point for commands that didn't arrive
2103 # via direct user input. It allows us to 'redo PIPE' to
2104 # re-execute command processing without reading a new command.
69893cff 2105 PIPE: {
7013f40c 2106 my $i = _DB__trim_command_and_return_first_component();
69893cff
RGS
2107
2108=head3 COMMAND ALIASES
2109
2110The debugger can create aliases for commands (these are stored in the
2111C<%alias> hash). Before a command is executed, the command loop looks it up
2112in the alias hash and substitutes the contents of the alias for the command,
2113completely replacing it.
2114
2115=cut
2116
2117 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2118 if ( $alias{$i} ) {
2119
69893cff
RGS
2120 # Squelch signal handling; we want to keep control here
2121 # if something goes loco during the alias eval.
2122 local $SIG{__DIE__};
2123 local $SIG{__WARN__};
2124
2125 # This is a command, so we eval it in the DEBUGGER's
2126 # scope! Otherwise, we can't see the special debugger
2127 # variables, or get to the debugger's subs. (Well, we
2128 # _could_, but why make it even more complicated?)
2129 eval "\$cmd =~ $alias{$i}";
2130 if ($@) {
2131 local $\ = '';
1f874cb6 2132 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2133 next CMD;
2134 }
2135 } ## end if ($alias{$i})
2136
2137=head3 MAIN-LINE COMMANDS
2138
2139All of these commands work up to and after the program being debugged has
b570d64b 2140terminated.
69893cff
RGS
2141
2142=head4 C<q> - quit
2143
b570d64b 2144Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2145try to execute further, cleaning any restart-related stuff out of the
2146environment, and executing with the last value of C<$?>.
2147
2148=cut
2149
3d7a2a93 2150 if ($cmd eq 'q') {
69893cff
RGS
2151 $fall_off_end = 1;
2152 clean_ENV();
2153 exit $?;
3d7a2a93 2154 }
69893cff 2155
611272bb 2156=head4 C<t> - trace [n]
69893cff
RGS
2157
2158Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2159If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2160
2161=cut
2162
174f9c5e 2163 $obj->_handle_t_command();
69893cff
RGS
2164
2165=head4 C<S> - list subroutines matching/not matching a pattern
2166
2167Walks through C<%sub>, checking to see whether or not to print the name.
2168
2169=cut
2170
826b9a2e
SF
2171 if (my ($print_all_subs, $should_reverse, $Spatt)
2172 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2173 # $Spatt is the pattern (if any) to use.
2174 # Reverse scan?
2175 my $Srev = defined $should_reverse;
2176 # No args - print all subs.
2177 my $Snocheck = !defined $print_all_subs;
69893cff
RGS
2178
2179 # Need to make these sane here.
e22ea7cc
RF
2180 local $\ = '';
2181 local $, = '';
69893cff
RGS
2182
2183 # Search through the debugger's magical hash of subs.
2184 # If $nocheck is true, just print the sub name.
2185 # Otherwise, check it against the pattern. We then use
2186 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2187 foreach $subname ( sort( keys %sub ) ) {
2188 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2189 print $OUT $subname, "\n";
2190 }
2191 }
2192 next CMD;
826b9a2e 2193 }
69893cff
RGS
2194
2195=head4 C<X> - list variables in current package
2196
b570d64b 2197Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2198appropriate C<V> command and fall through.
2199
2200=cut
2201
e22ea7cc 2202 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2203
2204=head4 C<V> - list variables
2205
b570d64b 2206Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2207
2208=cut
2209
2210 # Bare V commands get the currently-being-debugged package
2211 # added.
826b9a2e 2212 if ($cmd eq "V") {
e22ea7cc 2213 $cmd = "V $package";
826b9a2e 2214 }
69893cff
RGS
2215
2216 # V - show variables in package.
826b9a2e
SF
2217 if (my ($new_packname, $new_vars_str) =
2218 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
e22ea7cc 2219
69893cff
RGS
2220 # Save the currently selected filehandle and
2221 # force output to debugger's filehandle (dumpvar
2222 # just does "print" for output).
6b24a4b7 2223 my $savout = select($OUT);
69893cff
RGS
2224
2225 # Grab package name and variables to dump.
826b9a2e
SF
2226 $packname = $new_packname;
2227 my @vars = split( ' ', $new_vars_str );
69893cff
RGS
2228
2229 # If main::dumpvar isn't here, get it.
e81465be 2230 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2231 if ( defined &main::dumpvar ) {
2232
69893cff
RGS
2233 # We got it. Turn off subroutine entry/exit messages
2234 # for the moment, along with return values.
e22ea7cc
RF
2235 local $frame = 0;
2236 local $doret = -2;
69893cff
RGS
2237
2238 # must detect sigpipe failures - not catching
2239 # then will cause the debugger to die.
2240 eval {
2241 &main::dumpvar(
2242 $packname,
2243 defined $option{dumpDepth}
e22ea7cc
RF
2244 ? $option{dumpDepth}
2245 : -1, # assume -1 unless specified
69893cff 2246 @vars
e22ea7cc
RF
2247 );
2248 };
2249
2250 # The die doesn't need to include the $@, because
2251 # it will automatically get propagated for us.
2252 if ($@) {
2253 die unless $@ =~ /dumpvar print failed/;
2254 }
2255 } ## end if (defined &main::dumpvar)
2256 else {
2257
2258 # Couldn't load dumpvar.
2259 print $OUT "dumpvar.pl not available.\n";
2260 }
69893cff 2261
69893cff 2262 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2263 select($savout);
2264 next CMD;
826b9a2e 2265 }
69893cff
RGS
2266
2267=head4 C<x> - evaluate and print an expression
2268
2269Hands the expression off to C<DB::eval>, setting it up to print the value
2270via C<dumpvar.pl> instead of just printing it directly.
2271
2272=cut
2273
826b9a2e 2274 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2275 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2276
2277 # handle special "x 3 blah" syntax XXX propagate
2278 # doc back to special variables.
826b9a2e 2279 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2280 $onetimedumpDepth = $1;
2281 }
826b9a2e 2282 }
69893cff
RGS
2283
2284=head4 C<m> - print methods
2285
2286Just uses C<DB::methods> to determine what methods are available.
2287
2288=cut
2289
826b9a2e 2290 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2291 methods($1);
2292 next CMD;
826b9a2e 2293 }
69893cff
RGS
2294
2295 # m expr - set up DB::eval to do the work
826b9a2e 2296 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2297 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2298 }
69893cff
RGS
2299
2300=head4 C<f> - switch files
2301
2302=cut
2303
826b9a2e 2304 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2305 $file =~ s/\s+$//;
69893cff
RGS
2306
2307 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2308 if ( !$file ) {
2309 print $OUT
2310 "The old f command is now the r command.\n"; # hint
2311 print $OUT "The new f command switches filenames.\n";
2312 next CMD;
2313 } ## end if (!$file)
69893cff
RGS
2314
2315 # if not in magic file list, try a close match.
e22ea7cc
RF
2316 if ( !defined $main::{ '_<' . $file } ) {
2317 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2318 {
2319 $try = substr( $try, 2 );
1f874cb6 2320 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2321 $file = $try;
2322 }
2323 } ## end if (($try) = grep(m#^_<.*$file#...
2324 } ## end if (!defined $main::{ ...
69893cff
RGS
2325
2326 # If not successfully switched now, we failed.
e22ea7cc 2327 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2328 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2329 next CMD;
2330 }
69893cff 2331
e22ea7cc
RF
2332 # We switched, so switch the debugger internals around.
2333 elsif ( $file ne $filename ) {
2334 *dbline = $main::{ '_<' . $file };
2335 $max = $#dbline;
2336 $filename = $file;
2337 $start = 1;
2338 $cmd = "l";
2339 } ## end elsif ($file ne $filename)
2340
2341 # We didn't switch; say we didn't.
2342 else {
2343 print $OUT "Already in $file.\n";
2344 next CMD;
2345 }
826b9a2e 2346 }
69893cff
RGS
2347
2348=head4 C<.> - return to last-executed line.
2349
2350We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2351and then we look up the line in the magical C<%dbline> hash.
2352
2353=cut
2354
2355 # . command.
826b9a2e 2356 if ($cmd eq '.') {
e22ea7cc 2357 $incr = -1; # stay at current line
69893cff
RGS
2358
2359 # Reset everything to the old location.
e22ea7cc
RF
2360 $start = $line;
2361 $filename = $filename_ini;
2362 *dbline = $main::{ '_<' . $filename };
2363 $max = $#dbline;
69893cff
RGS
2364
2365 # Now where are we?
e22ea7cc
RF
2366 print_lineinfo($position);
2367 next CMD;
826b9a2e 2368 }
69893cff
RGS
2369
2370=head4 C<-> - back one window
2371
2372We change C<$start> to be one window back; if we go back past the first line,
2373we set it to be the first line. We ser C<$incr> to put us back at the
2374currently-executing line, and then put a C<l $start +> (list one window from
2375C<$start>) in C<$cmd> to be executed later.
2376
2377=cut
2378
2379 # - - back a window.
826b9a2e 2380 if ($cmd eq '-') {
e22ea7cc 2381
69893cff 2382 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2383 $start -= $incr + $window + 1;
2384 $start = 1 if $start <= 0;
2385 $incr = $window - 1;
69893cff
RGS
2386
2387 # Generate and execute a "l +" command (handled below).
e22ea7cc 2388 $cmd = 'l ' . ($start) . '+';
826b9a2e 2389 }
69893cff 2390
8481f647 2391=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
2392
2393In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2394problems, most notably that the default case of several commands destroying
2395the user's work in setting watchpoints, actions, etc. We wanted, however, to
2396retain the old commands for those who were used to using them or who preferred
2397them. At this point, we check for the new commands and call C<cmd_wrapper> to
2398deal with them instead of processing them in-line.
2399
2400=cut
2401
2402 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2403 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2404 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2405 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2406 next CMD;
826b9a2e 2407 }
69893cff
RGS
2408
2409=head4 C<y> - List lexicals in higher scope
2410
826b9a2e 2411Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2412above the current one and then displays then using C<dumpvar.pl>.
2413
2414=cut
2415
826b9a2e
SF
2416 if (my ($match_level, $match_vars)
2417 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2418
2419 # See if we've got the necessary support.
2420 eval { require PadWalker; PadWalker->VERSION(0.08) }
2421 or &warn(
2422 $@ =~ /locate/
2423 ? "PadWalker module not found - please install\n"
2424 : $@
2425 )
2426 and next CMD;
2427
2428 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2429 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2430 defined &main::dumpvar
2431 or print $OUT "dumpvar.pl not available.\n"
2432 and next CMD;
2433
2434 # Got all the modules we need. Find them and print them.
826b9a2e 2435 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2436
2437 # Find the pad.
826b9a2e 2438 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2439
2440 # Oops. Can't find it.
2441 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2442
2443 # Show the desired vars with dumplex().
2444 my $savout = select($OUT);
2445
2446 # Have dumplex dump the lexicals.
e22ea7cc 2447 dumpvar::dumplex( $_, $h->{$_},
69893cff 2448 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2449 @vars )
2450 for sort keys %$h;
69893cff
RGS
2451 select($savout);
2452 next CMD;
826b9a2e 2453 }
69893cff
RGS
2454
2455=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2456
2457All of the commands below this point don't work after the program being
2458debugged has ended. All of them check to see if the program has ended; this
2459allows the commands to be relocated without worrying about a 'line of
2460demarcation' above which commands can be entered anytime, and below which
2461they can't.
2462
2463=head4 C<n> - single step, but don't trace down into subs
2464
2465Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2466when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2467so a null command knows what to re-execute.
69893cff
RGS
2468
2469=cut
2470
e22ea7cc 2471 # n - next
826b9a2e 2472 if ($cmd eq 'n') {
8481f647 2473 next CMD if _DB__is_finished();
e22ea7cc 2474
69893cff
RGS
2475 # Single step, but don't enter subs.
2476 $single = 2;
e22ea7cc 2477
69893cff 2478 # Save for empty command (repeat last).
e22ea7cc
RF
2479 $laststep = $cmd;
2480 last CMD;
826b9a2e 2481 }
69893cff
RGS
2482
2483=head4 C<s> - single-step, entering subs
2484
826b9a2e 2485Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2486subs. Also saves C<s> as C<$lastcmd>.
2487
2488=cut
2489
2490 # s - single step.
826b9a2e 2491 if ($cmd eq 's') {
e22ea7cc 2492
69893cff
RGS
2493 # Get out and restart the command loop if program
2494 # has finished.
8481f647 2495 next CMD if _DB__is_finished();
e22ea7cc 2496
69893cff 2497 # Single step should enter subs.
e22ea7cc
RF
2498 $single = 1;
2499
69893cff 2500 # Save for empty command (repeat last).
e22ea7cc
RF
2501 $laststep = $cmd;
2502 last CMD;
826b9a2e 2503 }
69893cff
RGS
2504
2505=head4 C<c> - run continuously, setting an optional breakpoint
2506
2507Most of the code for this command is taken up with locating the optional
2508breakpoint, which is either a subroutine name or a line number. We set
2509the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2510in this and all call levels above this one.
2511
2512=cut
2513
2514 # c - start continuous execution.
ef18ae63 2515 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2516
69893cff
RGS
2517 # Hey, show's over. The debugged program finished
2518 # executing already.
8481f647 2519 next CMD if _DB__is_finished();
69893cff
RGS
2520
2521 # Capture the place to put a one-time break.
ef18ae63 2522 $subname = $i;
69893cff 2523
e22ea7cc
RF
2524 # Probably not needed, since we finish an interactive
2525 # sub-session anyway...
2526 # local $filename = $filename;
2527 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2528 #
2529 # The above question wonders if localizing the alias
2530 # to the magic array works or not. Since it's commented
2531 # out, we'll just leave that to speculation for now.
2532
2533 # If the "subname" isn't all digits, we'll assume it
2534 # is a subroutine name, and try to find it.
e22ea7cc
RF
2535 if ( $subname =~ /\D/ ) { # subroutine name
2536 # Qualify it to the current package unless it's
2537 # already qualified.
69893cff
RGS
2538 $subname = $package . "::" . $subname
2539 unless $subname =~ /::/;
e22ea7cc 2540
69893cff
RGS
2541 # find_sub will return "file:line_number" corresponding
2542 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2543 # break up the return value, and assign it in one
69893cff 2544 # operation.
e22ea7cc 2545 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2546
2547 # Force the line number to be numeric.
e22ea7cc 2548 $i += 0;
69893cff
RGS
2549
2550 # If we got a line number, we found the sub.
e22ea7cc
RF
2551 if ($i) {
2552
69893cff
RGS
2553 # Switch all the debugger's internals around so
2554 # we're actually working with that file.
e22ea7cc
RF
2555 $filename = $file;
2556 *dbline = $main::{ '_<' . $filename };
2557
69893cff 2558 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2559 $had_breakpoints{$filename} |= 1;
2560
69893cff
RGS
2561 # Scan forward to the first executable line
2562 # after the 'sub whatever' line.
e22ea7cc
RF
2563 $max = $#dbline;
2564 ++$i while $dbline[$i] == 0 && $i < $max;
2565 } ## end if ($i)
69893cff
RGS
2566
2567 # We didn't find a sub by that name.
e22ea7cc
RF
2568 else {
2569 print $OUT "Subroutine $subname not found.\n";
2570 next CMD;
2571 }
2572 } ## end if ($subname =~ /\D/)
69893cff
RGS
2573
2574 # At this point, either the subname was all digits (an
2575 # absolute line-break request) or we've scanned through
2576 # the code following the definition of the sub, looking
2577 # for an executable, which we may or may not have found.
2578 #
2579 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2580 # got a request to break at some line somewhere. On
2581 # one hand, if there wasn't any real subroutine name
2582 # involved, this will be a request to break in the current
2583 # file at the specified line, so we have to check to make
69893cff
RGS
2584 # sure that the line specified really is breakable.
2585 #
2586 # On the other hand, if there was a subname supplied, the
3c4b39be 2587 # preceding block has moved us to the proper file and
69893cff
RGS
2588 # location within that file, and then scanned forward
2589 # looking for the next executable line. We have to make
2590 # sure that one was found.
2591 #
2592 # On the gripping hand, we can't do anything unless the
2593 # current value of $i points to a valid breakable line.
2594 # Check that.
e22ea7cc
RF
2595 if ($i) {
2596
69893cff 2597 # Breakable?
e22ea7cc
RF
2598 if ( $dbline[$i] == 0 ) {
2599 print $OUT "Line $i not breakable.\n";
2600 next CMD;
2601 }
2602
69893cff 2603 # Yes. Set up the one-time-break sigil.
e22ea7cc 2604 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2605 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2606 } ## end if ($i)
69893cff
RGS
2607
2608 # Turn off stack tracing from here up.
2c247e84
SF
2609 for my $i (0 .. $stack_depth) {
2610 $stack[ $i ] &= ~1;
e22ea7cc
RF
2611 }
2612 last CMD;
ef18ae63 2613 }
69893cff
RGS
2614
2615=head4 C<r> - return from a subroutine
2616
2617For C<r> to work properly, the debugger has to stop execution again
2618immediately after the return is executed. This is done by forcing
2619single-stepping to be on in the call level above the current one. If
2620we are printing return values when a C<r> is executed, set C<$doret>
2621appropriately, and force us out of the command loop.
2622
2623=cut
2624
2625 # r - return from the current subroutine.
ef18ae63 2626 if ($cmd eq 'r') {
e22ea7cc 2627
98dc9551 2628 # Can't do anything if the program's over.
8481f647 2629 next CMD if _DB__is_finished();
e22ea7cc 2630
69893cff 2631 # Turn on stack trace.
e22ea7cc
RF
2632 $stack[$stack_depth] |= 1;
2633
69893cff 2634 # Print return value unless the stack is empty.
e22ea7cc
RF
2635 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2636 last CMD;
ef18ae63 2637 }
69893cff 2638
69893cff
RGS
2639=head4 C<T> - stack trace
2640
2641Just calls C<DB::print_trace>.
2642
2643=cut
2644
ef18ae63 2645 if ($cmd eq 'T') {
e22ea7cc
RF
2646 print_trace( $OUT, 1 ); # skip DB
2647 next CMD;
ef18ae63 2648 }
69893cff
RGS
2649
2650=head4 C<w> - List window around current line.
2651
2652Just calls C<DB::cmd_w>.
2653
2654=cut
2655
ef18ae63
SF
2656 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2657 &cmd_w( 'w', $arg );
2658 next CMD;
2659 }
69893cff
RGS
2660
2661=head4 C<W> - watch-expression processing.
2662
b570d64b 2663Just calls C<DB::cmd_W>.
69893cff
RGS
2664
2665=cut
2666
ef18ae63
SF
2667 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2668 &cmd_W( 'W', $arg );
2669 next CMD;
2670 }
69893cff
RGS
2671
2672=head4 C</> - search forward for a string in the source
2673
ef18ae63 2674We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2675bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2676If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2677mess us up.
2678
2679=cut
2680
ef18ae63
SF
2681 # The pattern as a string.
2682 use vars qw($inpat);
69893cff 2683
ef18ae63 2684 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2685
2686 # Remove the final slash.
e22ea7cc 2687 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2688
2689 # If the pattern isn't null ...
e22ea7cc 2690 if ( $inpat ne "" ) {
69893cff
RGS
2691
2692 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2693 local $SIG{__DIE__};
2694 local $SIG{__WARN__};
69893cff
RGS
2695
2696 # Create the pattern.
22fc883d 2697 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
e22ea7cc
RF
2698 if ( $@ ne "" ) {
2699
69893cff 2700 # Oops. Bad pattern. No biscuit.
e22ea7cc 2701 # Print the eval error and go back for more
69893cff 2702 # commands.
e22ea7cc
RF
2703 print $OUT "$@";
2704 next CMD;
2705 }
2706 $pat = $inpat;
2707 } ## end if ($inpat ne "")
69893cff
RGS
2708
2709 # Set up to stop on wrap-around.
e22ea7cc 2710 $end = $start;
69893cff
RGS
2711
2712 # Don't move off the current line.
e22ea7cc 2713 $incr = -1;
69893cff
RGS
2714
2715 # Done in eval so nothing breaks if the pattern
2716 # does something weird.
e22ea7cc 2717 eval '
22fc883d 2718 no strict q/vars/;
e22ea7cc 2719 for (;;) {
69893cff 2720 # Move ahead one line.
e22ea7cc 2721 ++$start;
69893cff
RGS
2722
2723 # Wrap if we pass the last line.
e22ea7cc 2724 $start = 1 if ($start > $max);
69893cff
RGS
2725
2726 # Stop if we have gotten back to this line again,
e22ea7cc 2727 last if ($start == $end);
69893cff
RGS
2728
2729 # A hit! (Note, though, that we are doing
2730 # case-insensitive matching. Maybe a qr//
2731 # expression would be better, so the user could
2732 # do case-sensitive matching if desired.
e22ea7cc
RF
2733 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2734 if ($slave_editor) {
69893cff 2735 # Handle proper escaping in the slave.
e22ea7cc 2736 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2737 }
e22ea7cc 2738 else {
69893cff 2739 # Just print the line normally.
e22ea7cc
RF
2740 print $OUT "$start:\t",$dbline[$start],"\n";
2741 }
69893cff 2742 # And quit since we found something.
e22ea7cc
RF
2743 last;
2744 }
2745 } ';
2746
69893cff 2747 # If we wrapped, there never was a match.
e22ea7cc
RF
2748 print $OUT "/$pat/: not found\n" if ( $start == $end );
2749 next CMD;
ef18ae63 2750 }
69893cff
RGS
2751
2752=head4 C<?> - search backward for a string in the source
2753
2754Same as for C</>, except the loop runs backwards.
2755
2756=cut
2757
2758 # ? - backward pattern search.
ef18ae63 2759 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2760
2761 # Get the pattern, remove trailing question mark.
e22ea7cc 2762 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2763
2764 # If we've got one ...
e22ea7cc 2765 if ( $inpat ne "" ) {
69893cff
RGS
2766
2767 # Turn off die & warn handlers.
e22ea7cc
RF
2768 local $SIG{__DIE__};
2769 local $SIG{__WARN__};
2770 eval '$inpat =~ m' . "\a$inpat\a";
2771
2772 if ( $@ ne "" ) {
2773
69893cff 2774 # Ouch. Not good. Print the error.
e22ea7cc
RF
2775 print $OUT $@;
2776 next CMD;
2777 }
2778 $pat = $inpat;
69893cff 2779 } ## end if ($inpat ne "")
e22ea7cc 2780
69893cff 2781 # Where we are now is where to stop after wraparound.
e22ea7cc 2782 $end = $start;
69893cff
RGS
2783
2784 # Don't move away from this line.
e22ea7cc 2785 $incr = -1;
69893cff
RGS
2786
2787 # Search inside the eval to prevent pattern badness
2788 # from killing us.
e22ea7cc 2789 eval '
22fc883d 2790 no strict q/vars/;
e22ea7cc 2791 for (;;) {
69893cff 2792 # Back up a line.
e22ea7cc 2793 --$start;
69893cff
RGS
2794
2795 # Wrap if we pass the first line.
e22ea7cc
RF
2796
2797 $start = $max if ($start <= 0);
69893cff
RGS
2798
2799 # Quit if we get back where we started,
e22ea7cc 2800 last if ($start == $end);
69893cff
RGS
2801
2802 # Match?
e22ea7cc
RF
2803 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2804 if ($slave_editor) {
69893cff 2805 # Yep, follow slave editor requirements.
e22ea7cc 2806 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2807 }
e22ea7cc 2808 else {
69893cff 2809 # Yep, just print normally.
e22ea7cc
RF
2810 print $OUT "$start:\t",$dbline[$start],"\n";
2811 }
69893cff
RGS
2812
2813 # Found, so done.
e22ea7cc
RF
2814 last;
2815 }
2816 } ';
2817
2818 # Say we failed if the loop never found anything,
2819 print $OUT "?$pat?: not found\n" if ( $start == $end );
2820 next CMD;
ef18ae63 2821 }
69893cff
RGS
2822
2823=head4 C<$rc> - Recall command
2824
2825Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2826that the terminal supports history). It find the the command required, puts it
2827into C<$cmd>, and redoes the loop to execute it.
2828
2829=cut
2830
e22ea7cc 2831 # $rc - recall command.
ef18ae63 2832 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2833
2834 # No arguments, take one thing off history.
e22ea7cc 2835 pop(@hist) if length($cmd) > 1;
69893cff 2836
e22ea7cc 2837 # Relative (- found)?
69893cff 2838 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2839 # N - go to that particular command slot or the last
69893cff 2840 # thing if nothing following.
ef18ae63 2841 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2842
2843 # Pick out the command desired.
e22ea7cc 2844 $cmd = $hist[$i];
69893cff
RGS
2845
2846 # Print the command to be executed and restart the loop
2847 # with that command in the buffer.
e22ea7cc
RF
2848 print $OUT $cmd, "\n";
2849 redo CMD;
ef18ae63 2850 }
69893cff
RGS
2851
2852=head4 C<$sh$sh> - C<system()> command
2853
2854Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2855C<STDOUT> from getting messed up.
2856
2857=cut
2858
2859 # $sh$sh - run a shell command (if it's all ASCII).
2860 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2861 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2862
69893cff 2863 # System it.
ef18ae63 2864 &system($arg);
e22ea7cc 2865 next CMD;
ef18ae63 2866 }
69893cff
RGS
2867
2868=head4 C<$rc I<pattern> $rc> - Search command history
2869
2870Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2871If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2872
2873=cut
2874
e22ea7cc 2875 # $rc pattern $rc - find a command in the history.
ef18ae63 2876 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2877
69893cff 2878 # Create the pattern to use.
ef18ae63 2879 $pat = "^$arg";
69893cff
RGS
2880
2881 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2882 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2883
2884 # Look backward through the history.
72d7d80d 2885 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2886 # Stop if we find it.
e22ea7cc
RF
2887 last if $hist[$i] =~ /$pat/;
2888 }
2889
2890 if ( !$i ) {
69893cff 2891
69893cff 2892 # Never found it.
e22ea7cc
RF
2893 print $OUT "No such command!\n\n";
2894 next CMD;
2895 }
69893cff
RGS
2896
2897 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2898 $cmd = $hist[$i];
2899 print $OUT $cmd, "\n";
2900 redo CMD;
ef18ae63 2901 }
69893cff 2902
ef18ae63 2903=head4 C<$sh> - Invoke a shell
69893cff
RGS
2904
2905Uses C<DB::system> to invoke a shell.
2906
2907=cut
2908
2909 # $sh - start a shell.
ef18ae63 2910 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2911
69893cff
RGS
2912 # Run the user's shell. If none defined, run Bourne.
2913 # We resume execution when the shell terminates.
e22ea7cc
RF
2914 &system( $ENV{SHELL} || "/bin/sh" );
2915 next CMD;
ef18ae63 2916 }
69893cff
RGS
2917
2918=head4 C<$sh I<command>> - Force execution of a command in a shell
2919
2920Like the above, but the command is passed to the shell. Again, we use
2921C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2922
2923=cut
2924
2925 # $sh command - start a shell and run a command in it.
ef18ae63 2926 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
2927
2928 # XXX: using csh or tcsh destroys sigint retvals!
2929 #&system($1); # use this instead
69893cff
RGS
2930
2931 # use the user's shell, or Bourne if none defined.
ef18ae63 2932 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 2933 next CMD;
ef18ae63 2934 }
69893cff
RGS
2935
2936=head4 C<H> - display commands in history
2937
2938Prints the contents of C<@hist> (if any).
2939
2940=cut
2941
ef18ae63 2942 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
2943 @hist = @truehist = ();
2944 print $OUT "History cleansed\n";
2945 next CMD;
ef18ae63 2946 }
e22ea7cc 2947
ef18ae63
SF
2948 if (my ($num)
2949 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
2950
2951 # Anything other than negative numbers is ignored by
69893cff 2952 # the (incorrect) pattern, so this test does nothing.
ef18ae63 2953 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
2954
2955 # Set to the minimum if less than zero.
e22ea7cc 2956 $hist = 0 if $hist < 0;
69893cff 2957
e22ea7cc 2958 # Start at the end of the array.
69893cff
RGS
2959 # Stay in while we're still above the ending value.
2960 # Tick back by one each time around the loop.
72d7d80d 2961 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
2962
2963 # Print the command unless it has no arguments.
e22ea7cc
RF
2964 print $OUT "$i: ", $hist[$i], "\n"
2965 unless $hist[$i] =~ /^.?$/;
2966 }
2967 next CMD;
ef18ae63 2968 }
69893cff
RGS
2969
2970=head4 C<man, doc, perldoc> - look up documentation
2971
2972Just calls C<runman()> to print the appropriate document.
2973
2974=cut
2975
e22ea7cc 2976 # man, perldoc, doc - show manual pages.
ef18ae63
SF
2977 if (my ($man_page)
2978 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2979 runman($man_page);
e22ea7cc 2980 next CMD;
ef18ae63 2981 }
69893cff
RGS
2982
2983=head4 C<p> - print
2984
2985Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2986the bottom of the loop.
2987
2988=cut
2989
ef18ae63 2990 my $print_cmd = 'print {$DB::OUT} ';
69893cff 2991 # p - print (no args): print $_.
ef18ae63
SF
2992 if ($cmd eq 'p') {
2993 $cmd = $print_cmd . '$_';
2994 }
69893cff
RGS
2995
2996 # p - print the given expression.
ef18ae63 2997 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
2998
2999=head4 C<=> - define command alias
3000
3001Manipulates C<%alias> to add or list command aliases.
3002
3003=cut
3004
e22ea7cc 3005 # = - set up a command alias.
ef18ae63 3006 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
3007 my @keys;
3008 if ( length $cmd == 0 ) {
3009
69893cff 3010 # No args, get current aliases.
e22ea7cc
RF
3011 @keys = sort keys %alias;
3012 }
3013 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3014
69893cff
RGS
3015 # Creating a new alias. $k is alias name, $v is
3016 # alias value.
3017
e22ea7cc
RF
3018 # can't use $_ or kill //g state
3019 for my $x ( $k, $v ) {
3020
3021 # Escape "alarm" characters.
3022 $x =~ s/\a/\\a/g;
3023 }
69893cff
RGS
3024
3025 # Substitute key for value, using alarm chars
e22ea7cc 3026 # as separators (which is why we escaped them in
69893cff 3027 # the command).
e22ea7cc 3028 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3029
3030 # Turn off standard warn and die behavior.
e22ea7cc
RF
3031 local $SIG{__DIE__};
3032 local $SIG{__WARN__};
69893cff
RGS
3033
3034 # Is it valid Perl?
e22ea7cc
RF
3035 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3036
69893cff 3037 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3038 print $OUT "Can't alias $k to $v: $@\n";
3039 delete $alias{$k};
3040 next CMD;
3041 }
3042
69893cff 3043 # We'll only list the new one.
e22ea7cc 3044 @keys = ($k);
69893cff
RGS
3045 } ## end elsif (my ($k, $v) = ($cmd...
3046
3047 # The argument is the alias to list.
e22ea7cc
RF
3048 else {
3049 @keys = ($cmd);
3050 }
69893cff
RGS
3051
3052 # List aliases.
e22ea7cc
RF
3053 for my $k (@keys) {
3054
98dc9551 3055 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
3056 # We use control-G as the delimiter because it's not
3057 # likely to appear in the alias.
e22ea7cc
RF
3058 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3059
69893cff 3060 # Print the alias.
e22ea7cc
RF
3061 print $OUT "$k\t= $1\n";
3062 }
3063 elsif ( defined $alias{$k} ) {
3064
69893cff 3065 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3066 print $OUT "$k\t$alias{$k}\n";
3067 }
3068 else {
3069
69893cff 3070 # No such, dude.
e22ea7cc
RF
3071 print "No alias for $k\n";
3072 }
69893cff 3073 } ## end for my $k (@keys)
e22ea7cc 3074 next CMD;
ef18ae63 3075 }
69893cff
RGS
3076
3077=head4 C<source> - read commands from a file.
3078
3079Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3080pick it up.
3081
3082=cut
3083
e22ea7cc 3084 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3085 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3086 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3087
69893cff 3088 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3089 push @cmdfhs, $fh;
3090 }
3091 else {
3092
3093 # Couldn't open it.
ef18ae63 3094 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3095 }
3096 next CMD;
ef18ae63 3097 }
69893cff 3098
ef18ae63
SF
3099 if (my ($which_cmd, $position)
3100 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3101
3102 my ($fn, $line_num);
3103 if ($position =~ m{\A\d+\z})
3104 {
3105 $fn = $filename;
3106 $line_num = $position;
3107 }
ef18ae63
SF
3108 elsif (my ($new_fn, $new_line_num)
3109 = $position =~ m{\A(.*):(\d+)\z}) {
3110 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3111 }
3112 else
3113 {
3114 &warn("Wrong spec for enable/disable argument.\n");
3115 }
3116
3117 if (defined($fn)) {
3118 if (_has_breakpoint_data_ref($fn, $line_num)) {
3119 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3120 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3121 );
3122 }
3123 else {
3124 &warn("No breakpoint set at ${fn}:${line_num}\n");
3125 }
3126 }
3127
3128 next CMD;
ef18ae63 3129 }
e09195af 3130
69893cff
RGS
3131=head4 C<save> - send current history to a file
3132
3133Takes the complete history, (not the shrunken version you see with C<H>),
3134and saves it to the given filename, so it can be replayed using C<source>.
3135
3136Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3137
3138=cut
3139
3140 # save source - write commands to a file for later use
ef18ae63
SF
3141 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3142 my $filename = $new_fn || '.perl5dbrc'; # default?
3143 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3144
3145 # chomp to remove extraneous newlines from source'd files
3146 chomp( my @truelist =
3147 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3148 @truehist );
3149 print $fh join( "\n", @truelist );
69893cff 3150 print "commands saved in $file\n";
e22ea7cc
RF
3151 }
3152 else {
ef18ae63 3153 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3154 }
3155 next CMD;
ef18ae63 3156 }
69893cff 3157
7fddc82f
RF
3158=head4 C<R> - restart
3159
ef18ae63 3160Restart the debugger session.
7fddc82f
RF
3161
3162=head4 C<rerun> - rerun the current session
3163
3164Return to any given position in the B<true>-history list
3165
3166=cut
3167
3168 # R - restart execution.
3169 # rerun - controlled restart execution.
ff41e38d
SF
3170 if (my ($cmd_cmd, $cmd_params) =
3171 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3172 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3173
ca28b541
AP
3174 # Close all non-system fds for a clean restart. A more
3175 # correct method would be to close all fds that were not
3176 # open when the process started, but this seems to be
3177 # hard. See "debugger 'R'estart and open database
3178 # connections" on p5p.
3179
47d3bbda 3180 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3181 if (eval { require POSIX }) {
5332cc68 3182 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3183 }
3184
3185 if (defined $max_fd) {
3186 foreach ($^F+1 .. $max_fd-1) {
3187 next unless open FD_TO_CLOSE, "<&=$_";
3188 close(FD_TO_CLOSE);
3189 }
3190 }
3191
7fddc82f
RF
3192 # And run Perl again. We use exec() to keep the
3193 # PID stable (and that way $ini_pids is still valid).
3194 exec(@args) || print $OUT "exec failed: $!\n";
3195
3196 last CMD;
ff41e38d 3197 }
7fddc82f 3198
69893cff
RGS
3199=head4 C<|, ||> - pipe output through the pager.
3200
be9a9b1d 3201For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3202(the program's standard output). For C<||>, we only save C<OUT>. We open a
3203pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3204is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3205set C<$signal>, sending us back into the debugger.
3206
3207We then trim off the pipe symbols and C<redo> the command loop at the
3208C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3209reading another.
3210
3211=cut
3212
3213 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3214 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3215 if ( $pager =~ /^\|/ ) {
3216
69893cff 3217 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3218 open( SAVEOUT, ">&STDOUT" )
3219 || &warn("Can't save STDOUT");
3220 open( STDOUT, ">&OUT" )
3221 || &warn("Can't redirect STDOUT");
69893cff 3222 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3223 else {
3224
69893cff 3225 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3226 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3227 }
69893cff
RGS
3228
3229 # Fix up environment to record we have less if so.
e22ea7cc
RF
3230 fix_less();
3231
3232 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3233
69893cff 3234 # Couldn't open pipe to pager.
1f874cb6 3235 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3236 if ( $pager =~ /^\|/ ) {
3237
69893cff 3238 # Redirect I/O back again.
e22ea7cc
RF
3239 open( OUT, ">&STDOUT" ) # XXX: lost message
3240 || &warn("Can't restore DB::OUT");
3241 open( STDOUT, ">&SAVEOUT" )
3242 || &warn("Can't restore STDOUT");
3243 close(SAVEOUT);
69893cff 3244 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3245 else {
3246
69893cff 3247 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3248 open( OUT, ">&STDOUT" ) # XXX: lost message
3249 || &warn("Can't restore DB::OUT");
3250 }
3251 next CMD;
69893cff
RGS
3252 } ## end unless ($piped = open(OUT,...
3253
3254 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3255 $SIG{PIPE} = \&DB::catch
3256 if $pager =~ /^\|/
3257 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3258
70c9432b
SF
3259 OUT->autoflush(1);
3260 # Save current filehandle, and put it back.
e22ea7cc 3261 $selected = select(OUT);
69893cff 3262 # Don't put it back if pager was a pipe.
e22ea7cc 3263 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3264
3265 # Trim off the pipe symbols and run the command now.
ff41e38d 3266 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3267 redo PIPE;
ff41e38d 3268 }
69893cff
RGS
3269
3270=head3 END OF COMMAND PARSING
3271
ff41e38d
SF
3272Anything left in C<$cmd> at this point is a Perl expression that we want to
3273evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3274any variables we might want to address in the C<DB> package.
3275
3276=cut
3277
3278 # t - turn trace on.
ff41e38d
SF
3279 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3280 my $trace_arg = $1;
3281 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3282 }
69893cff
RGS
3283
3284 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3285 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3286 $laststep = 's';
3287 }
69893cff
RGS
3288
3289 # n - single-step, but not into subs. Remember last command
e22ea7cc 3290 # was 'n'.
ff41e38d
SF
3291 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3292 $laststep = 'n';
3293 }
69893cff 3294
e22ea7cc 3295 } # PIPE:
69893cff 3296
e22ea7cc 3297 # Make sure the flag that says "the debugger's running" is
69893cff 3298 # still on, to make sure we get control again.
e22ea7cc 3299 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3300
3301 # Run *our* eval that executes in the caller's context.
7c54f46a 3302 DB::eval();
69893cff
RGS
3303
3304 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3305 if ($onetimeDump) {
3306 $onetimeDump = undef;
69893cff 3307 $onetimedumpDepth = undef;
e22ea7cc
RF
3308 }
3309 elsif ( $term_pid == $$ ) {
8380a245 3310 eval { # May run under miniperl, when not available...
c7e68384
IZ
3311 STDOUT->flush();
3312 STDERR->flush();
8380a245 3313 };
e22ea7cc 3314
69893cff 3315 # XXX If this is the master pid, print a newline.
8380a245 3316 print {$OUT} "\n";
e22ea7cc
RF
3317 }
3318 } ## end while (($term || &setterm...
69893cff
RGS
3319
3320=head3 POST-COMMAND PROCESSING
3321
3322After each command, we check to see if the command output was piped anywhere.
3323If so, we go through the necessary code to unhook the pipe and go back to
3324our standard filehandles for input and output.
3325
3326=cut
3327
e22ea7cc 3328 continue { # CMD:
69893cff
RGS
3329
3330 # At the end of every command:
e22ea7cc
RF
3331 if ($piped) {
3332
69893cff 3333 # Unhook the pipe mechanism now.
e22ea7cc
RF
3334 if ( $pager =~ /^\|/ ) {
3335
69893cff 3336 # No error from the child.
e22ea7cc 3337 $? = 0;
69893cff 3338
e22ea7cc
RF
3339 # we cannot warn here: the handle is missing --tchrist
3340 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3341
e22ea7cc 3342 # most of the $? crud was coping with broken cshisms
69893cff 3343 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3344 if ($?) {
1f874cb6 3345 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3346 if ( $? == -1 ) {
3347 print SAVEOUT "shell returned -1\n";
3348 }
3349 elsif ( $? >> 8 ) {
3350 print SAVEOUT ( $? & 127 )
3351 ? " (SIG#" . ( $? & 127 ) . ")"
3352 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3353 }
3354 else {
3355 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3356 }
69893cff
RGS
3357 } ## end if ($?)
3358
e22ea7cc 3359 # Reopen filehandle for our output (if we can) and
69893cff 3360 # restore STDOUT (if we can).
e22ea7cc
RF
3361 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3362 open( STDOUT, ">&SAVEOUT" )
3363 || &warn("Can't restore STDOUT");
69893cff
RGS
3364
3365 # Turn off pipe exception handler if necessary.
e22ea7cc 3366 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3367
e22ea7cc
RF
3368 # Will stop ignoring SIGPIPE if done like nohup(1)
3369 # does SIGINT but Perl doesn't give us a choice.
69893cff 3370 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3371 else {
3372
69893cff 3373 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3374 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3375 }
69893cff
RGS
3376
3377 # Close filehandle pager was using, restore the normal one
3378 # if necessary,
3379 close(SAVEOUT);
e22ea7cc 3380 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3381
3382 # No pipes now.
e22ea7cc 3383 $piped = "";
69893cff 3384 } ## end if ($piped)
e22ea7cc 3385 } # CMD:
69893cff
RGS
3386
3387=head3 COMMAND LOOP TERMINATION
3388
3389When commands have finished executing, we come here. If the user closed the
3390input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3391evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3392C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3393The interpreter will then execute the next line and then return control to us
3394again.
3395
3396=cut
3397
3398 # No more commands? Quit.
1f874cb6 3399 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3400
3401 # Evaluate post-prompt commands.
e22ea7cc 3402 foreach $evalarg (@$post) {
7c54f46a 3403 DB::eval();
e22ea7cc
RF
3404 }
3405 } # if ($single || $signal)
69893cff
RGS
3406
3407 # Put the user's globals back where you found them.
e22ea7cc 3408 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3409 ();
3410} ## end sub DB
3411
22fc883d
SF
3412package DB::Obj;
3413
3414sub new {
3415 my $class = shift;
3416
3417 my $self = bless {}, $class;
3418
3419 $self->_init(@_);
3420
3421 return $self;
3422}
3423
3424sub _init {
3425 my ($self, $args) = @_;
3426
3427 %{$self} = (%$self, %$args);
3428
3429 return;
3430}
3431
3432{
3433 no strict 'refs';
3434 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3435 my $slot = $slot_name;
3436 *{$slot} = sub {
3437 my $self = shift;
3438
3439 if (@_) {
3440 ${ $self->{$slot} } = shift;
3441 }
3442
3443 return ${ $self->{$slot} };
3444 };
8def6eff
SF
3445
3446 *{"append_to_$slot"} = sub {
3447 my $self = shift;
3448 my $s = shift;
3449
3450 return $self->$slot($self->$slot . $s);
3451 };
22fc883d
SF
3452 }
3453}
3454
3455sub _DB_on_init__initialize_globals
3456{
3457 my $self = shift;
3458
3459 # Check for whether we should be running continuously or not.
3460 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3461 if ( $single and not $second_time++ ) {
22fc883d
SF
3462
3463 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3464 if ($runnonstop) { # Disable until signal
22fc883d
SF
3465 # If there's any call stack in place, turn off single
3466 # stepping into subs throughout the stack.
8ad70697
SF
3467 for my $i (0 .. $stack_depth) {
3468 $stack[ $i ] &= ~1;
22fc883d
SF
3469 }
3470
3471 # And we are now no longer in single-step mode.
ebd0282e 3472 $single = 0;
22fc883d
SF
3473
3474 # If we simply returned at this point, we wouldn't get
3475 # the trace info. Fall on through.
3476 # return;
3477 } ## end if ($runnonstop)
3478
8ad70697 3479 elsif ($ImmediateStop) {
22fc883d
SF
3480
3481 # We are supposed to stop here; XXX probably a break.
8ad70697 3482 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3483 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3484 # us into the command loop
3485 }
3486 } ## end if ($single and not $second_time...
3487
3488 # If we're in single-step mode, or an interrupt (real or fake)
3489 # has occurred, turn off non-stop mode.
ebd0282e 3490 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3491
3492 return;
3493}
3494
3495sub _DB__handle_watch_expressions
3496{
3497 my $self = shift;
3498
931ac036 3499 if ( $trace & 2 ) {
8ad70697
SF
3500 for my $n (0 .. $#to_watch) {
3501 $evalarg = $to_watch[$n];
3502 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3503
3504 # Fix context DB::eval() wants to return an array, but
3505 # we need a scalar here.
7c54f46a 3506 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3507 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3508
3509 # Did it change?
8ad70697 3510 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3511
3512 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3513 $signal = 1;
8ad70697
SF
3514 print {$OUT} <<EOP;
3515Watchpoint $n:\t$to_watch[$n] changed:
3516 old value:\t$old_watch[$n]
22fc883d
SF
3517 new value:\t$val
3518EOP
8ad70697 3519 $old_watch[$n] = $val;
22fc883d
SF
3520 } ## end if ($val ne $old_watch...
3521 } ## end for my $n (0 ..
3522 } ## end if ($trace & 2)
3523
3524 return;
3525}
3526
ad46ac70
SF
3527sub _my_print_lineinfo
3528{
3529 my ($self, $i, $incr_pos) = @_;
3530
18b5b545 3531 if ($frame) {
ad46ac70 3532 # Print it indented if tracing is on.
8ad70697 3533 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3534 "$i:\t$DB::dbline[$i]" . $self->after );
3535 }
3536 else {
3537 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3538 }
3539}
3540
44a07e3e 3541sub _curr_line {
18b5b545 3542 return $DB::dbline[$line];
44a07e3e
SF
3543}
3544
22fc883d
SF
3545sub _DB__grab_control
3546{
3547 my $self = shift;
3548
3549 # Yes, grab control.
3550 if ($DB::slave_editor) {
3551
3552 # Tell the editor to update its position.
18b5b545 3553 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3554 DB::print_lineinfo($self->position());
3555 }
3556
3557=pod
3558
3559Special check: if we're in package C<DB::fake>, we've gone through the
3560C<END> block at least once. We set up everything so that we can continue
3561to enter commands and have a valid context to be in.
3562
3563=cut
3564
3565 elsif ( $DB::package eq 'DB::fake' ) {
3566
3567 # Fallen off the end already.
3568 if (!$DB::term) {
3569 DB::setterm();
3570 }
3571
3572 DB::print_help(<<EOP);
3573Debugged program terminated. Use B<q> to quit or B<R> to restart,
3574use B<o> I<inhibit_exit> to avoid stopping after program termination,
3575B<h q>, B<h R> or B<h o> to get additional info.
3576EOP