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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 648 $onetimedumpDepth
6b24a4b7
SF
649 @options
650 $osingle
651 $otrace
6b24a4b7
SF
652 $pager
653 $post
654 %postponed
655 $prc
656 $pre
657 $pretype
658 $psh
659 @RememberOnROptions
660 $remoteport
661 @res
662 $rl
663 @saved
6b24a4b7 664 $signalLevel
6b24a4b7
SF
665 $start
666 $sub
6b24a4b7 667 $term
6b24a4b7
SF
668 $usercontext
669 $warnLevel
670 $window
671);
672
0b83f3d9
SF
673our (
674 $evalarg,
675 $frame,
676 $ImmediateStop,
677 $line,
678 $onetimeDump,
1ce985d2 679 %option,
0b83f3d9 680 $OUT,
1ce985d2 681 $packname,
0b83f3d9
SF
682 $signal,
683 $single,
9d0b71b3
SF
684 %sub,
685 $subname,
0b83f3d9 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.
7793e5c2 1217our ($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
6b24a4b7
SF
1746 $fall_off_end
1747 $file
1748 $filename_ini
1749 $finished
1750 %had_breakpoints
1751 $incr
1752 $laststep
1753 $level
1754 $max
6b24a4b7
SF
1755 $package
1756 $rc
1757 $sh
6b24a4b7 1758 $try
2c247e84 1759 $end
6b24a4b7
SF
1760);
1761
1ce985d2
SF
1762our (
1763 $doret,
1764 $stack_depth,
1765 @stack,
1766 @to_watch,
1767 @old_watch,
1768);
8ad70697 1769
6791e41b
SF
1770sub _DB__determine_if_we_should_break
1771{
1772 # if we have something here, see if we should break.
1773 # $stop is lexical and local to this block - $action on the other hand
1774 # is global.
1775 my $stop;
1776
1777 if ( $dbline{$line}
1778 && _is_breakpoint_enabled($filename, $line)
1779 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1780 {
1781
1782 # Stop if the stop criterion says to just stop.
1783 if ( $stop eq '1' ) {
1784 $signal |= 1;
1785 }
1786
1787 # It's a conditional stop; eval it in the user's context and
1788 # see if we should stop. If so, remove the one-time sigil.
1789 elsif ($stop) {
1790 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1791 &eval;
1792 # If the breakpoint is temporary, then delete its enabled status.
1793 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1794 _cancel_breakpoint_temp_enabled_status($filename, $line);
1795 }
1796 }
1797 } ## end if ($dbline{$line} && ...
1798}
1799
8481f647
SF
1800sub _DB__is_finished {
1801 if ($finished and $level <= 1) {
1802 end_report();
1803 return 1;
1804 }
1805 else {
1806 return;
1807 }
1808}
1809
32bbadc6
SF
1810sub _DB__read_next_cmd
1811{
1812 my ($tid) = @_;
1813
1814 # We have a terminal, or can get one ...
1815 if (!$term) {
1816 setterm();
1817 }
1818
1819 # ... and it belogs to this PID or we get one for this PID ...
1820 if ($term_pid != $$) {
1821 resetterm(1);
1822 }
1823
1824 # ... and we got a line of command input ...
1825 $cmd = DB::readline(
1826 "$pidprompt $tid DB"
1827 . ( '<' x $level )
1828 . ( $#hist + 1 )
1829 . ( '>' x $level ) . " "
1830 );
1831
1832 return defined($cmd);
1833}
1834
7013f40c
SF
1835sub _DB__trim_command_and_return_first_component {
1836 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1837 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1838
1839 $cmd =~ m{\A(\S*)};
1840 return $1;
1841}
1842
2b0b9dd1
SF
1843sub DB {
1844
1845 # lock the debugger and get the thread id for the prompt
1846 lock($DBGR);
1847 my $tid;
1848 my $position;
1849 my ($prefix, $after, $infix);
1850 my $pat;
22fc883d 1851 my $explicit_stop;
2b0b9dd1
SF
1852
1853 if ($ENV{PERL5DB_THREADED}) {
1854 $tid = eval { "[".threads->tid."]" };
1855 }
1856
22fc883d
SF
1857 my $obj = DB::Obj->new(
1858 {
1859 position => \$position,
1860 prefix => \$prefix,
1861 after => \$after,
1862 explicit_stop => \$explicit_stop,
1863 infix => \$infix,
1864 },
1865 );
1866
1867 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 1868
69893cff
RGS
1869 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1870 # The code being debugged may have altered them.
d338d6fe 1871 &save;
69893cff
RGS
1872
1873 # Since DB::DB gets called after every line, we can use caller() to
1874 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1875 # caller is returning all the extra information when called from the
69893cff 1876 # debugger.
e22ea7cc 1877 local ( $package, $filename, $line ) = caller;
6b24a4b7 1878 $filename_ini = $filename;
69893cff
RGS
1879
1880 # set up the context for DB::eval, so it can properly execute
1881 # code on behalf of the user. We add the package in so that the
1882 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1883 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1884
1885 # Create an alias to the active file magical array to simplify
1886 # the code here.
e22ea7cc 1887 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1888
69893cff 1889 # Last line in the program.
55783941 1890 $max = $#dbline;
69893cff 1891
22fc883d 1892 _DB__determine_if_we_should_break(@_);
69893cff
RGS
1893
1894 # Preserve the current stop-or-not, and see if any of the W
1895 # (watch expressions) has changed.
36477c24 1896 my $was_signal = $signal;
69893cff
RGS
1897
1898 # If we have any watch expressions ...
22fc883d 1899 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
1900
1901=head2 C<watchfunction()>
1902
1903C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1904function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1905current package, filename, and line as its parameters.
1906
b570d64b 1907The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1908debugger's context, so it has access to all of the debugger's internal
1909data structures and functions.
1910
1911C<watchfunction()> can control the debugger's actions. Any of the following
1912will cause the debugger to return control to the user's program after
1913C<watchfunction()> executes:
1914
b570d64b 1915=over 4
69893cff 1916
be9a9b1d
AT
1917=item *
1918
1919Returning a false value from the C<watchfunction()> itself.
1920
1921=item *
1922
1923Altering C<$single> to a false value.
1924
1925=item *
69893cff 1926
be9a9b1d 1927Altering C<$signal> to a false value.
69893cff 1928
be9a9b1d 1929=item *
69893cff 1930
be9a9b1d 1931Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1932check for C<watchfunction()>. This can be done with
1933
1934 $trace &= ~4;
1935
1936=back
1937
1938=cut
1939
e22ea7cc 1940 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1941 # current package, filename, and line. The function executes in
1942 # the DB:: package.
e22ea7cc
RF
1943 if ( $trace & 4 ) { # User-installed watch
1944 return
1945 if watchfunction( $package, $filename, $line )
1946 and not $single
1947 and not $was_signal
1948 and not( $trace & ~4 );
69893cff
RGS
1949 } ## end if ($trace & 4)
1950
e22ea7cc 1951 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1952 # turn off the signal now.
6027b9a3 1953 $was_signal = $signal;
69893cff
RGS
1954 $signal = 0;
1955
1956=head2 GETTING READY TO EXECUTE COMMANDS
1957
1958The debugger decides to take control if single-step mode is on, the
1959C<t> command was entered, or the user generated a signal. If the program
1960has fallen off the end, we set things up so that entering further commands
1961won't cause trouble, and we say that the program is over.
1962
1963=cut
1964
8dc67a69
SF
1965 # Make sure that we always print if asked for explicitly regardless
1966 # of $trace_to_depth .
22fc883d 1967 $explicit_stop = ($single || $was_signal);
8dc67a69 1968
69893cff
RGS
1969 # Check to see if we should grab control ($single true,
1970 # trace set appropriately, or we got a signal).
8dc67a69 1971 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 1972 $obj->_DB__grab_control(@_);
69893cff
RGS
1973 } ## end if ($single || ($trace...
1974
1975=pod
1976
1977If there's an action to be executed for the line we stopped at, execute it.
b570d64b 1978If there are any preprompt actions, execute those as well.
e219e2fb
RF
1979
1980=cut
1981
69893cff 1982 # If there's an action, do it now.
05da04df
SF
1983 if ($action) {
1984 $evalarg = $action;
1985 DB::eval();
1986 }
e219e2fb 1987
69893cff
RGS
1988 # Are we nested another level (e.g., did we evaluate a function
1989 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
1990 if ( $single || $was_signal ) {
1991
69893cff 1992 # Yes, go down a level.
e22ea7cc 1993 local $level = $level + 1;
69893cff
RGS
1994
1995 # Do any pre-prompt actions.
e22ea7cc 1996 foreach $evalarg (@$pre) {
7c54f46a 1997 DB::eval();
e22ea7cc 1998 }
69893cff
RGS
1999
2000 # Complain about too much recursion if we passed the limit.
05da04df
SF
2001 if ($single & 4) {
2002 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2003 }
69893cff
RGS
2004
2005 # The line we're currently on. Set $incr to -1 to stay here
2006 # until we get a command that tells us to advance.
e22ea7cc
RF
2007 $start = $line;
2008 $incr = -1; # for backward motion.
69893cff
RGS
2009
2010 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2011 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2012
2013=head2 WHERE ARE WE?
2014
2015XXX Relocate this section?
2016
2017The debugger normally shows the line corresponding to the current line of
2018execution. Sometimes, though, we want to see the next line, or to move elsewhere
2019in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2020
be9a9b1d
AT
2021C<$incr> controls by how many lines the I<current> line should move forward
2022after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2023line shouldn't change.
2024
be9a9b1d 2025C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2026move forwards or backwards from when doing an C<L> or C<-> command.
2027
2028C<$max> tells the debugger where the last line of the current file is. It's
2029used to terminate loops most often.
2030
2031=head2 THE COMMAND LOOP
2032
2033Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2034in two parts:
2035
2036=over 4
2037
be9a9b1d
AT
2038=item *
2039
2040The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2041reads a command and then executes it.
2042
be9a9b1d
AT
2043=item *
2044
2045The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2046is wholly contained inside the C<CMD> block and only executes a command.
2047Used to handle commands running inside a pager.
2048
2049=back
2050
2051So why have two labels to restart the loop? Because sometimes, it's easier to
2052have a command I<generate> another command and then re-execute the loop to do
2053the new command. This is faster, but perhaps a bit more convoluted.
2054
2055=cut
2056
2057 # The big command dispatch loop. It keeps running until the
2058 # user yields up control again.
2059 #
2060 # If we have a terminal for input, and we get something back
2061 # from readline(), keep on processing.
6b24a4b7
SF
2062 my $piped;
2063 my $selected;
2064
e22ea7cc 2065 CMD:
32bbadc6 2066 while (_DB__read_next_cmd($tid))
69893cff 2067 {
e22ea7cc 2068
8380a245 2069 share($cmd);
69893cff
RGS
2070 # ... try to execute the input as debugger commands.
2071
2072 # Don't stop running.
2073 $single = 0;
2074
2075 # No signal is active.
2076 $signal = 0;
2077
2078 # Handle continued commands (ending with \):
3d7a2a93 2079 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2080 $cmd .= DB::readline(" cont: ");
e22ea7cc 2081 redo CMD;
3d7a2a93 2082 }
69893cff
RGS
2083
2084=head4 The null command
2085
be9a9b1d 2086A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2087command out of C<$laststep> (where it was recorded previously), and copy it
2088back into C<$cmd> to be executed below. If there wasn't any previous command,
2089we'll do nothing below (no command will match). If there was, we also save it
2090in the command history and fall through to allow the command parsing to pick
2091it up.
2092
2093=cut
2094
2095 # Empty input means repeat the last command.
eeb7da96
SF
2096 if ($cmd eq '') {
2097 $cmd = $laststep;
2098 }
e22ea7cc 2099 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2100 if (length($cmd) >= 2) {
2101 push( @hist, $cmd );
2102 }
e22ea7cc 2103 push( @truehist, $cmd );
2dbd01ad
SF
2104 share(@hist);
2105 share(@truehist);
e22ea7cc
RF
2106
2107 # This is a restart point for commands that didn't arrive
2108 # via direct user input. It allows us to 'redo PIPE' to
2109 # re-execute command processing without reading a new command.
69893cff 2110 PIPE: {
7013f40c 2111 my $i = _DB__trim_command_and_return_first_component();
69893cff
RGS
2112
2113=head3 COMMAND ALIASES
2114
2115The debugger can create aliases for commands (these are stored in the
2116C<%alias> hash). Before a command is executed, the command loop looks it up
2117in the alias hash and substitutes the contents of the alias for the command,
2118completely replacing it.
2119
2120=cut
2121
2122 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2123 if ( $alias{$i} ) {
2124
69893cff
RGS
2125 # Squelch signal handling; we want to keep control here
2126 # if something goes loco during the alias eval.
2127 local $SIG{__DIE__};
2128 local $SIG{__WARN__};
2129
2130 # This is a command, so we eval it in the DEBUGGER's
2131 # scope! Otherwise, we can't see the special debugger
2132 # variables, or get to the debugger's subs. (Well, we
2133 # _could_, but why make it even more complicated?)
2134 eval "\$cmd =~ $alias{$i}";
2135 if ($@) {
2136 local $\ = '';
1f874cb6 2137 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2138 next CMD;
2139 }
2140 } ## end if ($alias{$i})
2141
2142=head3 MAIN-LINE COMMANDS
2143
2144All of these commands work up to and after the program being debugged has
b570d64b 2145terminated.
69893cff
RGS
2146
2147=head4 C<q> - quit
2148
b570d64b 2149Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2150try to execute further, cleaning any restart-related stuff out of the
2151environment, and executing with the last value of C<$?>.
2152
2153=cut
2154
3d7a2a93 2155 if ($cmd eq 'q') {
69893cff
RGS
2156 $fall_off_end = 1;
2157 clean_ENV();
2158 exit $?;
3d7a2a93 2159 }
69893cff 2160
611272bb 2161=head4 C<t> - trace [n]
69893cff
RGS
2162
2163Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2164If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2165
2166=cut
2167
9d0b71b3 2168 $obj->_handle_t_command;
69893cff
RGS
2169
2170=head4 C<S> - list subroutines matching/not matching a pattern
2171
2172Walks through C<%sub>, checking to see whether or not to print the name.
2173
2174=cut
2175
9d0b71b3 2176 $obj->_handle_S_command;
69893cff
RGS
2177
2178=head4 C<X> - list variables in current package
2179
b570d64b 2180Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2181appropriate C<V> command and fall through.
2182
69893cff
RGS
2183=head4 C<V> - list variables
2184
b570d64b 2185Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2186
2187=cut
2188
1ce985d2 2189 $obj->_handle_V_command_and_X_command;
69893cff
RGS
2190
2191=head4 C<x> - evaluate and print an expression
2192
2193Hands the expression off to C<DB::eval>, setting it up to print the value
2194via C<dumpvar.pl> instead of just printing it directly.
2195
2196=cut
2197
826b9a2e 2198 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2199 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2200
2201 # handle special "x 3 blah" syntax XXX propagate
2202 # doc back to special variables.
826b9a2e 2203 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2204 $onetimedumpDepth = $1;
2205 }
826b9a2e 2206 }
69893cff
RGS
2207
2208=head4 C<m> - print methods
2209
2210Just uses C<DB::methods> to determine what methods are available.
2211
2212=cut
2213
826b9a2e 2214 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2215 methods($1);
2216 next CMD;
826b9a2e 2217 }
69893cff
RGS
2218
2219 # m expr - set up DB::eval to do the work
826b9a2e 2220 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2221 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2222 }
69893cff
RGS
2223
2224=head4 C<f> - switch files
2225
2226=cut
2227
826b9a2e 2228 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2229 $file =~ s/\s+$//;
69893cff
RGS
2230
2231 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2232 if ( !$file ) {
2233 print $OUT
2234 "The old f command is now the r command.\n"; # hint
2235 print $OUT "The new f command switches filenames.\n";
2236 next CMD;
2237 } ## end if (!$file)
69893cff
RGS
2238
2239 # if not in magic file list, try a close match.
e22ea7cc
RF
2240 if ( !defined $main::{ '_<' . $file } ) {
2241 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2242 {
2243 $try = substr( $try, 2 );
1f874cb6 2244 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2245 $file = $try;
2246 }
2247 } ## end if (($try) = grep(m#^_<.*$file#...
2248 } ## end if (!defined $main::{ ...
69893cff
RGS
2249
2250 # If not successfully switched now, we failed.
e22ea7cc 2251 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2252 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2253 next CMD;
2254 }
69893cff 2255
e22ea7cc
RF
2256 # We switched, so switch the debugger internals around.
2257 elsif ( $file ne $filename ) {
2258 *dbline = $main::{ '_<' . $file };
2259 $max = $#dbline;
2260 $filename = $file;
2261 $start = 1;
2262 $cmd = "l";
2263 } ## end elsif ($file ne $filename)
2264
2265 # We didn't switch; say we didn't.
2266 else {
2267 print $OUT "Already in $file.\n";
2268 next CMD;
2269 }
826b9a2e 2270 }
69893cff
RGS
2271
2272=head4 C<.> - return to last-executed line.
2273
2274We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2275and then we look up the line in the magical C<%dbline> hash.
2276
2277=cut
2278
2279 # . command.
826b9a2e 2280 if ($cmd eq '.') {
e22ea7cc 2281 $incr = -1; # stay at current line
69893cff
RGS
2282
2283 # Reset everything to the old location.
e22ea7cc
RF
2284 $start = $line;
2285 $filename = $filename_ini;
2286 *dbline = $main::{ '_<' . $filename };
2287 $max = $#dbline;
69893cff
RGS
2288
2289 # Now where are we?
e22ea7cc
RF
2290 print_lineinfo($position);
2291 next CMD;
826b9a2e 2292 }
69893cff
RGS
2293
2294=head4 C<-> - back one window
2295
2296We change C<$start> to be one window back; if we go back past the first line,
2297we set it to be the first line. We ser C<$incr> to put us back at the
2298currently-executing line, and then put a C<l $start +> (list one window from
2299C<$start>) in C<$cmd> to be executed later.
2300
2301=cut
2302
2303 # - - back a window.
826b9a2e 2304 if ($cmd eq '-') {
e22ea7cc 2305
69893cff 2306 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2307 $start -= $incr + $window + 1;
2308 $start = 1 if $start <= 0;
2309 $incr = $window - 1;
69893cff
RGS
2310
2311 # Generate and execute a "l +" command (handled below).
e22ea7cc 2312 $cmd = 'l ' . ($start) . '+';
826b9a2e 2313 }
69893cff 2314
8481f647 2315=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
2316
2317In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2318problems, most notably that the default case of several commands destroying
2319the user's work in setting watchpoints, actions, etc. We wanted, however, to
2320retain the old commands for those who were used to using them or who preferred
2321them. At this point, we check for the new commands and call C<cmd_wrapper> to
2322deal with them instead of processing them in-line.
2323
2324=cut
2325
2326 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2327 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2328 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2329 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2330 next CMD;
826b9a2e 2331 }
69893cff
RGS
2332
2333=head4 C<y> - List lexicals in higher scope
2334
826b9a2e 2335Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2336above the current one and then displays then using C<dumpvar.pl>.
2337
2338=cut
2339
826b9a2e
SF
2340 if (my ($match_level, $match_vars)
2341 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2342
2343 # See if we've got the necessary support.
2344 eval { require PadWalker; PadWalker->VERSION(0.08) }
2345 or &warn(
2346 $@ =~ /locate/
2347 ? "PadWalker module not found - please install\n"
2348 : $@
2349 )
2350 and next CMD;
2351
2352 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2353 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2354 defined &main::dumpvar
2355 or print $OUT "dumpvar.pl not available.\n"
2356 and next CMD;
2357
2358 # Got all the modules we need. Find them and print them.
826b9a2e 2359 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2360
2361 # Find the pad.
826b9a2e 2362 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2363
2364 # Oops. Can't find it.
2365 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2366
2367 # Show the desired vars with dumplex().
2368 my $savout = select($OUT);
2369
2370 # Have dumplex dump the lexicals.
e22ea7cc 2371 dumpvar::dumplex( $_, $h->{$_},
69893cff 2372 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2373 @vars )
2374 for sort keys %$h;
69893cff
RGS
2375 select($savout);
2376 next CMD;
826b9a2e 2377 }
69893cff
RGS
2378
2379=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2380
2381All of the commands below this point don't work after the program being
2382debugged has ended. All of them check to see if the program has ended; this
2383allows the commands to be relocated without worrying about a 'line of
2384demarcation' above which commands can be entered anytime, and below which
2385they can't.
2386
2387=head4 C<n> - single step, but don't trace down into subs
2388
2389Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2390when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2391so a null command knows what to re-execute.
69893cff
RGS
2392
2393=cut
2394
e22ea7cc 2395 # n - next
826b9a2e 2396 if ($cmd eq 'n') {
8481f647 2397 next CMD if _DB__is_finished();
e22ea7cc 2398
69893cff
RGS
2399 # Single step, but don't enter subs.
2400 $single = 2;
e22ea7cc 2401
69893cff 2402 # Save for empty command (repeat last).
e22ea7cc
RF
2403 $laststep = $cmd;
2404 last CMD;
826b9a2e 2405 }
69893cff
RGS
2406
2407=head4 C<s> - single-step, entering subs
2408
826b9a2e 2409Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2410subs. Also saves C<s> as C<$lastcmd>.
2411
2412=cut
2413
2414 # s - single step.
826b9a2e 2415 if ($cmd eq 's') {
e22ea7cc 2416
69893cff
RGS
2417 # Get out and restart the command loop if program
2418 # has finished.
8481f647 2419 next CMD if _DB__is_finished();
e22ea7cc 2420
69893cff 2421 # Single step should enter subs.
e22ea7cc
RF
2422 $single = 1;
2423
69893cff 2424 # Save for empty command (repeat last).
e22ea7cc
RF
2425 $laststep = $cmd;
2426 last CMD;
826b9a2e 2427 }
69893cff
RGS
2428
2429=head4 C<c> - run continuously, setting an optional breakpoint
2430
2431Most of the code for this command is taken up with locating the optional
2432breakpoint, which is either a subroutine name or a line number. We set
2433the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2434in this and all call levels above this one.
2435
2436=cut
2437
2438 # c - start continuous execution.
ef18ae63 2439 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2440
69893cff
RGS
2441 # Hey, show's over. The debugged program finished
2442 # executing already.
8481f647 2443 next CMD if _DB__is_finished();
69893cff
RGS
2444
2445 # Capture the place to put a one-time break.
ef18ae63 2446 $subname = $i;
69893cff 2447
e22ea7cc
RF
2448 # Probably not needed, since we finish an interactive
2449 # sub-session anyway...
2450 # local $filename = $filename;
2451 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2452 #
2453 # The above question wonders if localizing the alias
2454 # to the magic array works or not. Since it's commented
2455 # out, we'll just leave that to speculation for now.
2456
2457 # If the "subname" isn't all digits, we'll assume it
2458 # is a subroutine name, and try to find it.
e22ea7cc
RF
2459 if ( $subname =~ /\D/ ) { # subroutine name
2460 # Qualify it to the current package unless it's
2461 # already qualified.
69893cff
RGS
2462 $subname = $package . "::" . $subname
2463 unless $subname =~ /::/;
e22ea7cc 2464
69893cff
RGS
2465 # find_sub will return "file:line_number" corresponding
2466 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2467 # break up the return value, and assign it in one
69893cff 2468 # operation.
e22ea7cc 2469 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2470
2471 # Force the line number to be numeric.
e22ea7cc 2472 $i += 0;
69893cff
RGS
2473
2474 # If we got a line number, we found the sub.
e22ea7cc
RF
2475 if ($i) {
2476
69893cff
RGS
2477 # Switch all the debugger's internals around so
2478 # we're actually working with that file.
e22ea7cc
RF
2479 $filename = $file;
2480 *dbline = $main::{ '_<' . $filename };
2481
69893cff 2482 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2483 $had_breakpoints{$filename} |= 1;
2484
69893cff
RGS
2485 # Scan forward to the first executable line
2486 # after the 'sub whatever' line.
e22ea7cc
RF
2487 $max = $#dbline;
2488 ++$i while $dbline[$i] == 0 && $i < $max;
2489 } ## end if ($i)
69893cff
RGS
2490
2491 # We didn't find a sub by that name.
e22ea7cc
RF
2492 else {
2493 print $OUT "Subroutine $subname not found.\n";
2494 next CMD;
2495 }
2496 } ## end if ($subname =~ /\D/)
69893cff
RGS
2497
2498 # At this point, either the subname was all digits (an
2499 # absolute line-break request) or we've scanned through
2500 # the code following the definition of the sub, looking
2501 # for an executable, which we may or may not have found.
2502 #
2503 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2504 # got a request to break at some line somewhere. On
2505 # one hand, if there wasn't any real subroutine name
2506 # involved, this will be a request to break in the current
2507 # file at the specified line, so we have to check to make
69893cff
RGS
2508 # sure that the line specified really is breakable.
2509 #
2510 # On the other hand, if there was a subname supplied, the
3c4b39be 2511 # preceding block has moved us to the proper file and
69893cff
RGS
2512 # location within that file, and then scanned forward
2513 # looking for the next executable line. We have to make
2514 # sure that one was found.
2515 #
2516 # On the gripping hand, we can't do anything unless the
2517 # current value of $i points to a valid breakable line.
2518 # Check that.
e22ea7cc
RF
2519 if ($i) {
2520
69893cff 2521 # Breakable?
e22ea7cc
RF
2522 if ( $dbline[$i] == 0 ) {
2523 print $OUT "Line $i not breakable.\n";
2524 next CMD;
2525 }
2526
69893cff 2527 # Yes. Set up the one-time-break sigil.
e22ea7cc 2528 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2529 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2530 } ## end if ($i)
69893cff
RGS
2531
2532 # Turn off stack tracing from here up.
2c247e84
SF
2533 for my $i (0 .. $stack_depth) {
2534 $stack[ $i ] &= ~1;
e22ea7cc
RF
2535 }
2536 last CMD;
ef18ae63 2537 }
69893cff
RGS
2538
2539=head4 C<r> - return from a subroutine
2540
2541For C<r> to work properly, the debugger has to stop execution again
2542immediately after the return is executed. This is done by forcing
2543single-stepping to be on in the call level above the current one. If
2544we are printing return values when a C<r> is executed, set C<$doret>
2545appropriately, and force us out of the command loop.
2546
2547=cut
2548
2549 # r - return from the current subroutine.
ef18ae63 2550 if ($cmd eq 'r') {
e22ea7cc 2551
98dc9551 2552 # Can't do anything if the program's over.
8481f647 2553 next CMD if _DB__is_finished();
e22ea7cc 2554
69893cff 2555 # Turn on stack trace.
e22ea7cc
RF
2556 $stack[$stack_depth] |= 1;
2557
69893cff 2558 # Print return value unless the stack is empty.
e22ea7cc
RF
2559 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2560 last CMD;
ef18ae63 2561 }
69893cff 2562
69893cff
RGS
2563=head4 C<T> - stack trace
2564
2565Just calls C<DB::print_trace>.
2566
2567=cut
2568
ef18ae63 2569 if ($cmd eq 'T') {
e22ea7cc
RF
2570 print_trace( $OUT, 1 ); # skip DB
2571 next CMD;
ef18ae63 2572 }
69893cff
RGS
2573
2574=head4 C<w> - List window around current line.
2575
2576Just calls C<DB::cmd_w>.
2577
2578=cut
2579
ef18ae63
SF
2580 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2581 &cmd_w( 'w', $arg );
2582 next CMD;
2583 }
69893cff
RGS
2584
2585=head4 C<W> - watch-expression processing.
2586
b570d64b 2587Just calls C<DB::cmd_W>.
69893cff
RGS
2588
2589=cut
2590
ef18ae63
SF
2591 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2592 &cmd_W( 'W', $arg );
2593 next CMD;
2594 }
69893cff
RGS
2595
2596=head4 C</> - search forward for a string in the source
2597
ef18ae63 2598We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2599bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2600If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2601mess us up.
2602
2603=cut
2604
ef18ae63
SF
2605 # The pattern as a string.
2606 use vars qw($inpat);
69893cff 2607
ef18ae63 2608 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2609
2610 # Remove the final slash.
e22ea7cc 2611 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2612
2613 # If the pattern isn't null ...
e22ea7cc 2614 if ( $inpat ne "" ) {
69893cff
RGS
2615
2616 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2617 local $SIG{__DIE__};
2618 local $SIG{__WARN__};
69893cff
RGS
2619
2620 # Create the pattern.
22fc883d 2621 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
e22ea7cc
RF
2622 if ( $@ ne "" ) {
2623
69893cff 2624 # Oops. Bad pattern. No biscuit.
e22ea7cc 2625 # Print the eval error and go back for more
69893cff 2626 # commands.
e22ea7cc
RF
2627 print $OUT "$@";
2628 next CMD;
2629 }
2630 $pat = $inpat;
2631 } ## end if ($inpat ne "")
69893cff
RGS
2632
2633 # Set up to stop on wrap-around.
e22ea7cc 2634 $end = $start;
69893cff
RGS
2635
2636 # Don't move off the current line.
e22ea7cc 2637 $incr = -1;
69893cff
RGS
2638
2639 # Done in eval so nothing breaks if the pattern
2640 # does something weird.
e22ea7cc 2641 eval '
22fc883d 2642 no strict q/vars/;
e22ea7cc 2643 for (;;) {
69893cff 2644 # Move ahead one line.
e22ea7cc 2645 ++$start;
69893cff
RGS
2646
2647 # Wrap if we pass the last line.
e22ea7cc 2648 $start = 1 if ($start > $max);
69893cff
RGS
2649
2650 # Stop if we have gotten back to this line again,
e22ea7cc 2651 last if ($start == $end);
69893cff
RGS
2652
2653 # A hit! (Note, though, that we are doing
2654 # case-insensitive matching. Maybe a qr//
2655 # expression would be better, so the user could
2656 # do case-sensitive matching if desired.
e22ea7cc
RF
2657 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2658 if ($slave_editor) {
69893cff 2659 # Handle proper escaping in the slave.
e22ea7cc 2660 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2661 }
e22ea7cc 2662 else {
69893cff 2663 # Just print the line normally.
e22ea7cc
RF
2664 print $OUT "$start:\t",$dbline[$start],"\n";
2665 }
69893cff 2666 # And quit since we found something.
e22ea7cc
RF
2667 last;
2668 }
2669 } ';
2670
69893cff 2671 # If we wrapped, there never was a match.
e22ea7cc
RF
2672 print $OUT "/$pat/: not found\n" if ( $start == $end );
2673 next CMD;
ef18ae63 2674 }
69893cff
RGS
2675
2676=head4 C<?> - search backward for a string in the source
2677
2678Same as for C</>, except the loop runs backwards.
2679
2680=cut
2681
2682 # ? - backward pattern search.
ef18ae63 2683 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2684
2685 # Get the pattern, remove trailing question mark.
e22ea7cc 2686 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2687
2688 # If we've got one ...
e22ea7cc 2689 if ( $inpat ne "" ) {
69893cff
RGS
2690
2691 # Turn off die & warn handlers.
e22ea7cc
RF
2692 local $SIG{__DIE__};
2693 local $SIG{__WARN__};
2694 eval '$inpat =~ m' . "\a$inpat\a";
2695
2696 if ( $@ ne "" ) {
2697
69893cff 2698 # Ouch. Not good. Print the error.
e22ea7cc
RF
2699 print $OUT $@;
2700 next CMD;
2701 }
2702 $pat = $inpat;
69893cff 2703 } ## end if ($inpat ne "")
e22ea7cc 2704
69893cff 2705 # Where we are now is where to stop after wraparound.
e22ea7cc 2706 $end = $start;
69893cff
RGS
2707
2708 # Don't move away from this line.
e22ea7cc 2709 $incr = -1;
69893cff
RGS
2710
2711 # Search inside the eval to prevent pattern badness
2712 # from killing us.
e22ea7cc 2713 eval '
22fc883d 2714 no strict q/vars/;
e22ea7cc 2715 for (;;) {
69893cff 2716 # Back up a line.
e22ea7cc 2717 --$start;
69893cff
RGS
2718
2719 # Wrap if we pass the first line.
e22ea7cc
RF
2720
2721 $start = $max if ($start <= 0);
69893cff
RGS
2722
2723 # Quit if we get back where we started,
e22ea7cc 2724 last if ($start == $end);
69893cff
RGS
2725
2726 # Match?
e22ea7cc
RF
2727 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2728 if ($slave_editor) {
69893cff 2729 # Yep, follow slave editor requirements.
e22ea7cc 2730 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2731 }
e22ea7cc 2732 else {
69893cff 2733 # Yep, just print normally.
e22ea7cc
RF
2734 print $OUT "$start:\t",$dbline[$start],"\n";
2735 }
69893cff
RGS
2736
2737 # Found, so done.
e22ea7cc
RF
2738 last;
2739 }
2740 } ';
2741
2742 # Say we failed if the loop never found anything,
2743 print $OUT "?$pat?: not found\n" if ( $start == $end );
2744 next CMD;
ef18ae63 2745 }
69893cff
RGS
2746
2747=head4 C<$rc> - Recall command
2748
2749Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2750that the terminal supports history). It find the the command required, puts it
2751into C<$cmd>, and redoes the loop to execute it.
2752
2753=cut
2754
e22ea7cc 2755 # $rc - recall command.
ef18ae63 2756 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2757
2758 # No arguments, take one thing off history.
e22ea7cc 2759 pop(@hist) if length($cmd) > 1;
69893cff 2760
e22ea7cc 2761 # Relative (- found)?
69893cff 2762 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2763 # N - go to that particular command slot or the last
69893cff 2764 # thing if nothing following.
ef18ae63 2765 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2766
2767 # Pick out the command desired.
e22ea7cc 2768 $cmd = $hist[$i];
69893cff
RGS
2769
2770 # Print the command to be executed and restart the loop
2771 # with that command in the buffer.
e22ea7cc
RF
2772 print $OUT $cmd, "\n";
2773 redo CMD;
ef18ae63 2774 }
69893cff
RGS
2775
2776=head4 C<$sh$sh> - C<system()> command
2777
2778Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2779C<STDOUT> from getting messed up.
2780
2781=cut
2782
2783 # $sh$sh - run a shell command (if it's all ASCII).
2784 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2785 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2786
69893cff 2787 # System it.
ef18ae63 2788 &system($arg);
e22ea7cc 2789 next CMD;
ef18ae63 2790 }
69893cff
RGS
2791
2792=head4 C<$rc I<pattern> $rc> - Search command history
2793
2794Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2795If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2796
2797=cut
2798
e22ea7cc 2799 # $rc pattern $rc - find a command in the history.
ef18ae63 2800 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2801
69893cff 2802 # Create the pattern to use.
ef18ae63 2803 $pat = "^$arg";
69893cff
RGS
2804
2805 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2806 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2807
2808 # Look backward through the history.
72d7d80d 2809 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2810 # Stop if we find it.
e22ea7cc
RF
2811 last if $hist[$i] =~ /$pat/;
2812 }
2813
2814 if ( !$i ) {
69893cff 2815
69893cff 2816 # Never found it.
e22ea7cc
RF
2817 print $OUT "No such command!\n\n";
2818 next CMD;
2819 }
69893cff
RGS
2820
2821 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2822 $cmd = $hist[$i];
2823 print $OUT $cmd, "\n";
2824 redo CMD;
ef18ae63 2825 }
69893cff 2826
ef18ae63 2827=head4 C<$sh> - Invoke a shell
69893cff
RGS
2828
2829Uses C<DB::system> to invoke a shell.
2830
2831=cut
2832
2833 # $sh - start a shell.
ef18ae63 2834 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2835
69893cff
RGS
2836 # Run the user's shell. If none defined, run Bourne.
2837 # We resume execution when the shell terminates.
e22ea7cc
RF
2838 &system( $ENV{SHELL} || "/bin/sh" );
2839 next CMD;
ef18ae63 2840 }
69893cff
RGS
2841
2842=head4 C<$sh I<command>> - Force execution of a command in a shell
2843
2844Like the above, but the command is passed to the shell. Again, we use
2845C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2846
2847=cut
2848
2849 # $sh command - start a shell and run a command in it.
ef18ae63 2850 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
2851
2852 # XXX: using csh or tcsh destroys sigint retvals!
2853 #&system($1); # use this instead
69893cff
RGS
2854
2855 # use the user's shell, or Bourne if none defined.
ef18ae63 2856 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 2857 next CMD;
ef18ae63 2858 }
69893cff
RGS
2859
2860=head4 C<H> - display commands in history
2861
2862Prints the contents of C<@hist> (if any).
2863
2864=cut
2865
ef18ae63 2866 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
2867 @hist = @truehist = ();
2868 print $OUT "History cleansed\n";
2869 next CMD;
ef18ae63 2870 }
e22ea7cc 2871
ef18ae63
SF
2872 if (my ($num)
2873 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
2874
2875 # Anything other than negative numbers is ignored by
69893cff 2876 # the (incorrect) pattern, so this test does nothing.
ef18ae63 2877 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
2878
2879 # Set to the minimum if less than zero.
e22ea7cc 2880 $hist = 0 if $hist < 0;
69893cff 2881
e22ea7cc 2882 # Start at the end of the array.
69893cff
RGS
2883 # Stay in while we're still above the ending value.
2884 # Tick back by one each time around the loop.
72d7d80d 2885 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
2886
2887 # Print the command unless it has no arguments.
e22ea7cc
RF
2888 print $OUT "$i: ", $hist[$i], "\n"
2889 unless $hist[$i] =~ /^.?$/;
2890 }
2891 next CMD;
ef18ae63 2892 }
69893cff
RGS
2893
2894=head4 C<man, doc, perldoc> - look up documentation
2895
2896Just calls C<runman()> to print the appropriate document.
2897
2898=cut
2899
e22ea7cc 2900 # man, perldoc, doc - show manual pages.
ef18ae63
SF
2901 if (my ($man_page)
2902 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2903 runman($man_page);
e22ea7cc 2904 next CMD;
ef18ae63 2905 }
69893cff
RGS
2906
2907=head4 C<p> - print
2908
2909Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2910the bottom of the loop.
2911
2912=cut
2913
ef18ae63 2914 my $print_cmd = 'print {$DB::OUT} ';
69893cff 2915 # p - print (no args): print $_.
ef18ae63
SF
2916 if ($cmd eq 'p') {
2917 $cmd = $print_cmd . '$_';
2918 }
69893cff
RGS
2919
2920 # p - print the given expression.
ef18ae63 2921 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
2922
2923=head4 C<=> - define command alias
2924
2925Manipulates C<%alias> to add or list command aliases.
2926
2927=cut
2928
e22ea7cc 2929 # = - set up a command alias.
ef18ae63 2930 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
2931 my @keys;
2932 if ( length $cmd == 0 ) {
2933
69893cff 2934 # No args, get current aliases.
e22ea7cc
RF
2935 @keys = sort keys %alias;
2936 }
2937 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
2938
69893cff
RGS
2939 # Creating a new alias. $k is alias name, $v is
2940 # alias value.
2941
e22ea7cc
RF
2942 # can't use $_ or kill //g state
2943 for my $x ( $k, $v ) {
2944
2945 # Escape "alarm" characters.
2946 $x =~ s/\a/\\a/g;
2947 }
69893cff
RGS
2948
2949 # Substitute key for value, using alarm chars
e22ea7cc 2950 # as separators (which is why we escaped them in
69893cff 2951 # the command).
e22ea7cc 2952 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
2953
2954 # Turn off standard warn and die behavior.
e22ea7cc
RF
2955 local $SIG{__DIE__};
2956 local $SIG{__WARN__};
69893cff
RGS
2957
2958 # Is it valid Perl?
e22ea7cc
RF
2959 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
2960
69893cff 2961 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
2962 print $OUT "Can't alias $k to $v: $@\n";
2963 delete $alias{$k};
2964 next CMD;
2965 }
2966
69893cff 2967 # We'll only list the new one.
e22ea7cc 2968 @keys = ($k);
69893cff
RGS
2969 } ## end elsif (my ($k, $v) = ($cmd...
2970
2971 # The argument is the alias to list.
e22ea7cc
RF
2972 else {
2973 @keys = ($cmd);
2974 }
69893cff
RGS
2975
2976 # List aliases.
e22ea7cc
RF
2977 for my $k (@keys) {
2978
98dc9551 2979 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
2980 # We use control-G as the delimiter because it's not
2981 # likely to appear in the alias.
e22ea7cc
RF
2982 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
2983
69893cff 2984 # Print the alias.
e22ea7cc
RF
2985 print $OUT "$k\t= $1\n";
2986 }
2987 elsif ( defined $alias{$k} ) {
2988
69893cff 2989 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
2990 print $OUT "$k\t$alias{$k}\n";
2991 }
2992 else {
2993
69893cff 2994 # No such, dude.
e22ea7cc
RF
2995 print "No alias for $k\n";
2996 }
69893cff 2997 } ## end for my $k (@keys)
e22ea7cc 2998 next CMD;
ef18ae63 2999 }
69893cff
RGS
3000
3001=head4 C<source> - read commands from a file.
3002
3003Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3004pick it up.
3005
3006=cut
3007
e22ea7cc 3008 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3009 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3010 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3011
69893cff 3012 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3013 push @cmdfhs, $fh;
3014 }
3015 else {
3016
3017 # Couldn't open it.
ef18ae63 3018 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3019 }
3020 next CMD;
ef18ae63 3021 }
69893cff 3022
ef18ae63
SF
3023 if (my ($which_cmd, $position)
3024 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3025
3026 my ($fn, $line_num);
3027 if ($position =~ m{\A\d+\z})
3028 {
3029 $fn = $filename;
3030 $line_num = $position;
3031 }
ef18ae63
SF
3032 elsif (my ($new_fn, $new_line_num)
3033 = $position =~ m{\A(.*):(\d+)\z}) {
3034 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3035 }
3036 else
3037 {
3038 &warn("Wrong spec for enable/disable argument.\n");
3039 }
3040
3041 if (defined($fn)) {
3042 if (_has_breakpoint_data_ref($fn, $line_num)) {
3043 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3044 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3045 );
3046 }
3047 else {
3048 &warn("No breakpoint set at ${fn}:${line_num}\n");
3049 }
3050 }
3051
3052 next CMD;
ef18ae63 3053 }
e09195af 3054
69893cff
RGS
3055=head4 C<save> - send current history to a file
3056
3057Takes the complete history, (not the shrunken version you see with C<H>),
3058and saves it to the given filename, so it can be replayed using C<source>.
3059
3060Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3061
3062=cut
3063
3064 # save source - write commands to a file for later use
ef18ae63
SF
3065 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3066 my $filename = $new_fn || '.perl5dbrc'; # default?
3067 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3068
3069 # chomp to remove extraneous newlines from source'd files
3070 chomp( my @truelist =
3071 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3072 @truehist );
3073 print $fh join( "\n", @truelist );
69893cff 3074 print "commands saved in $file\n";
e22ea7cc
RF
3075 }
3076 else {
ef18ae63 3077 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3078 }
3079 next CMD;
ef18ae63 3080 }
69893cff 3081
7fddc82f
RF
3082=head4 C<R> - restart
3083
ef18ae63 3084Restart the debugger session.
7fddc82f
RF
3085
3086=head4 C<rerun> - rerun the current session
3087
3088Return to any given position in the B<true>-history list
3089
3090=cut
3091
3092 # R - restart execution.
3093 # rerun - controlled restart execution.
ff41e38d
SF
3094 if (my ($cmd_cmd, $cmd_params) =
3095 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3096 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3097
ca28b541
AP
3098 # Close all non-system fds for a clean restart. A more
3099 # correct method would be to close all fds that were not
3100 # open when the process started, but this seems to be
3101 # hard. See "debugger 'R'estart and open database
3102 # connections" on p5p.
3103
47d3bbda 3104 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3105 if (eval { require POSIX }) {
5332cc68 3106 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3107 }
3108
3109 if (defined $max_fd) {
3110 foreach ($^F+1 .. $max_fd-1) {
3111 next unless open FD_TO_CLOSE, "<&=$_";
3112 close(FD_TO_CLOSE);
3113 }
3114 }
3115
7fddc82f
RF
3116 # And run Perl again. We use exec() to keep the
3117 # PID stable (and that way $ini_pids is still valid).
3118 exec(@args) || print $OUT "exec failed: $!\n";
3119
3120 last CMD;
ff41e38d 3121 }
7fddc82f 3122
69893cff
RGS
3123=head4 C<|, ||> - pipe output through the pager.
3124
be9a9b1d 3125For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3126(the program's standard output). For C<||>, we only save C<OUT>. We open a
3127pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3128is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3129set C<$signal>, sending us back into the debugger.
3130
3131We then trim off the pipe symbols and C<redo> the command loop at the
3132C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3133reading another.
3134
3135=cut
3136
3137 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3138 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3139 if ( $pager =~ /^\|/ ) {
3140
69893cff 3141 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3142 open( SAVEOUT, ">&STDOUT" )
3143 || &warn("Can't save STDOUT");
3144 open( STDOUT, ">&OUT" )
3145 || &warn("Can't redirect STDOUT");
69893cff 3146 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3147 else {
3148
69893cff 3149 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3150 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3151 }
69893cff
RGS
3152
3153 # Fix up environment to record we have less if so.
e22ea7cc
RF
3154 fix_less();
3155
3156 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3157
69893cff 3158 # Couldn't open pipe to pager.
1f874cb6 3159 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3160 if ( $pager =~ /^\|/ ) {
3161
69893cff 3162 # Redirect I/O back again.
e22ea7cc
RF
3163 open( OUT, ">&STDOUT" ) # XXX: lost message
3164 || &warn("Can't restore DB::OUT");
3165 open( STDOUT, ">&SAVEOUT" )
3166 || &warn("Can't restore STDOUT");
3167 close(SAVEOUT);
69893cff 3168 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3169 else {
3170
69893cff 3171 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3172 open( OUT, ">&STDOUT" ) # XXX: lost message
3173 || &warn("Can't restore DB::OUT");
3174 }
3175 next CMD;
69893cff
RGS
3176 } ## end unless ($piped = open(OUT,...
3177
3178 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3179 $SIG{PIPE} = \&DB::catch
3180 if $pager =~ /^\|/
3181 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3182
70c9432b
SF
3183 OUT->autoflush(1);
3184 # Save current filehandle, and put it back.
e22ea7cc 3185 $selected = select(OUT);
69893cff 3186 # Don't put it back if pager was a pipe.
e22ea7cc 3187 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3188
3189 # Trim off the pipe symbols and run the command now.
ff41e38d 3190 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3191 redo PIPE;
ff41e38d 3192 }
69893cff
RGS
3193
3194=head3 END OF COMMAND PARSING
3195
ff41e38d
SF
3196Anything left in C<$cmd> at this point is a Perl expression that we want to
3197evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3198any variables we might want to address in the C<DB> package.
3199
3200=cut
3201
3202 # t - turn trace on.
ff41e38d
SF
3203 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3204 my $trace_arg = $1;
3205 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3206 }
69893cff
RGS
3207
3208 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3209 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3210 $laststep = 's';
3211 }
69893cff
RGS
3212
3213 # n - single-step, but not into subs. Remember last command
e22ea7cc 3214 # was 'n'.
ff41e38d
SF
3215 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3216 $laststep = 'n';
3217 }
69893cff 3218
e22ea7cc 3219 } # PIPE:
69893cff 3220
e22ea7cc 3221 # Make sure the flag that says "the debugger's running" is
69893cff 3222 # still on, to make sure we get control again.
e22ea7cc 3223 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3224
3225 # Run *our* eval that executes in the caller's context.
7c54f46a 3226 DB::eval();
69893cff
RGS
3227
3228 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3229 if ($onetimeDump) {
3230 $onetimeDump = undef;
69893cff 3231 $onetimedumpDepth = undef;
e22ea7cc
RF
3232 }
3233 elsif ( $term_pid == $$ ) {
8380a245 3234 eval { # May run under miniperl, when not available...
c7e68384
IZ
3235 STDOUT->flush();
3236 STDERR->flush();
8380a245 3237 };
e22ea7cc 3238
69893cff 3239 # XXX If this is the master pid, print a newline.
8380a245 3240 print {$OUT} "\n";
e22ea7cc
RF
3241 }
3242 } ## end while (($term || &setterm...
69893cff
RGS
3243
3244=head3 POST-COMMAND PROCESSING
3245
3246After each command, we check to see if the command output was piped anywhere.
3247If so, we go through the necessary code to unhook the pipe and go back to
3248our standard filehandles for input and output.
3249
3250=cut
3251
e22ea7cc 3252 continue { # CMD:
69893cff
RGS
3253
3254 # At the end of every command:
e22ea7cc
RF
3255 if ($piped) {
3256
69893cff 3257 # Unhook the pipe mechanism now.
e22ea7cc
RF
3258 if ( $pager =~ /^\|/ ) {
3259
69893cff 3260 # No error from the child.
e22ea7cc 3261 $? = 0;
69893cff 3262
e22ea7cc
RF
3263 # we cannot warn here: the handle is missing --tchrist
3264 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3265
e22ea7cc 3266 # most of the $? crud was coping with broken cshisms
69893cff 3267 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3268 if ($?) {
1f874cb6 3269 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3270 if ( $? == -1 ) {
3271 print SAVEOUT "shell returned -1\n";
3272 }
3273 elsif ( $? >> 8 ) {
3274 print SAVEOUT ( $? & 127 )
3275 ? " (SIG#" . ( $? & 127 ) . ")"
3276 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3277 }
3278 else {
3279 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3280 }
69893cff
RGS
3281 } ## end if ($?)
3282
e22ea7cc 3283 # Reopen filehandle for our output (if we can) and
69893cff 3284 # restore STDOUT (if we can).
e22ea7cc
RF
3285 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3286 open( STDOUT, ">&SAVEOUT" )
3287 || &warn("Can't restore STDOUT");
69893cff
RGS
3288
3289 # Turn off pipe exception handler if necessary.
e22ea7cc 3290 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3291
e22ea7cc
RF
3292 # Will stop ignoring SIGPIPE if done like nohup(1)
3293 # does SIGINT but Perl doesn't give us a choice.
69893cff 3294 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3295 else {
3296
69893cff 3297 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3298 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3299 }
69893cff
RGS
3300
3301 # Close filehandle pager was using, restore the normal one
3302 # if necessary,
3303 close(SAVEOUT);
e22ea7cc 3304 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3305
3306 # No pipes now.
e22ea7cc 3307 $piped = "";
69893cff 3308 } ## end if ($piped)
e22ea7cc 3309 } # CMD:
69893cff
RGS
3310
3311=head3 COMMAND LOOP TERMINATION
3312
3313When commands have finished executing, we come here. If the user closed the
3314input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3315evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3316C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3317The interpreter will then execute the next line and then return control to us
3318again.
3319
3320=cut
3321
3322 # No more commands? Quit.
1f874cb6 3323 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3324
3325 # Evaluate post-prompt commands.
e22ea7cc 3326 foreach $evalarg (@$post) {
7c54f46a 3327 DB::eval();
e22ea7cc
RF
3328 }
3329 } # if ($single || $signal)
69893cff
RGS
3330
3331 # Put the user's globals back where you found them.
e22ea7cc 3332 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3333 ();
3334} ## end sub DB
3335
22fc883d
SF
3336package DB::Obj;
3337
3338sub new {
3339 my $class = shift;
3340
3341 my $self = bless {}, $class;
3342
3343 $self->_init(@_);
3344
3345 return $self;
3346}
3347
3348sub _init {
3349 my ($self, $args) = @_;
3350
3351 %{$self} = (%$self, %$args);
3352
3353 return;
3354}
3355
3356{
3357 no strict 'refs';
3358 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3359 my $slot = $slot_name;
3360 *{$slot} = sub {
3361 my $self = shift;
3362
3363 if (@_) {
3364 ${ $self->{$slot} } = shift;
3365 }
3366
3367 return ${ $self->{$slot} };
3368 };
8def6eff
SF
3369
3370 *{"append_to_$slot"} = sub {
3371 my $self = shift;
3372 my $s = shift;
3373
3374 return $self->$slot($self->$slot . $s);
3375 };
22fc883d
SF
3376 }
3377}
3378
3379sub _DB_on_init__initialize_globals
3380{
3381 my $self = shift;
3382
3383 # Check for whether we should be running continuously or not.
3384 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3385 if ( $single and not $second_time++ ) {
22fc883d
SF
3386
3387 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3388 if ($runnonstop) { # Disable until signal
22fc883d
SF
3389 # If there's any call stack in place, turn off single
3390 # stepping into subs throughout the stack.
8ad70697
SF
3391 for my $i (0 .. $stack_depth) {
3392 $stack[ $i ] &= ~1;
22fc883d
SF
3393 }
3394
3395 # And we are now no longer in single-step mode.
ebd0282e 3396 $single = 0;
22fc883d
SF
3397
3398 # If we simply returned at this point, we wouldn't get
3399 # the trace info. Fall on through.
3400 # return;
3401 } ## end if ($runnonstop)
3402
8ad70697 3403 elsif ($ImmediateStop) {
22fc883d
SF
3404
3405 # We are supposed to stop here; XXX probably a break.
8ad70697 3406 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3407 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3408 # us into the command loop
3409 }
3410 } ## end if ($single and not $second_time...
3411
3412 # If we're in single-step mode, or an interrupt (real or fake)
3413 # has occurred, turn off non-stop mode.
ebd0282e 3414 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3415
3416 return;
3417}
3418
3419sub _DB__handle_watch_expressions
3420{
3421 my $self = shift;
3422
931ac036 3423 if ( $trace & 2 ) {
8ad70697
SF
3424 for my $n (0 .. $#to_watch) {
3425 $evalarg = $to_watch[$n];
3426 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3427
3428 # Fix context DB::eval() wants to return an array, but
3429 # we need a scalar here.
7c54f46a 3430 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3431 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3432
3433 # Did it change?
8ad70697 3434 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3435
3436 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3437 $signal = 1;
8ad70697
SF
3438 print {$OUT} <<EOP;
3439Watchpoint $n:\t$to_watch[$n] changed:
3440 old value:\t$old_watch[$n]
22fc883d
SF
3441 new value:\t$val
3442EOP
8ad70697 3443 $old_watch[$n] = $val;
22fc883d
SF
3444 } ## end if ($val ne $old_watch...
3445 } ## end for my $n (0 ..
3446 } ## end if ($trace & 2)
3447
3448 return;
3449}
3450
ad46ac70
SF
3451sub _my_print_lineinfo
3452{
3453 my ($self, $i, $incr_pos) = @_;
3454
18b5b545 3455 if ($frame) {
ad46ac70 3456 # Print it indented if tracing is on.
8ad70697 3457 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3458 "$i:\t$DB::dbline[$i]" . $self->after );
3459 }
3460 else {
3461 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3462 }
3463}
3464
44a07e3e 3465sub _curr_line {
18b5b545 3466 return $DB::dbline[$line];
44a07e3e
SF
3467}
3468
22fc883d
SF
3469sub _DB__grab_control
3470{
3471 my $self = shift;
3472
3473 # Yes, grab control.
7793e5c2 3474 if ($slave_editor) {
22fc883d
SF
3475
3476 # Tell the editor to update its position.
18b5b545 3477 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3478 DB::print_lineinfo($self->position());
3479 }
3480
3481=pod
3482
3483Special check: if we're in package C<DB::fake>, we've gone through the
3484C<END> block at least once. We set up everything so that we can continue
3485to enter commands and have a valid context to be in.
3486
3487=cut
3488
3489 elsif ( $DB::package eq 'DB::fake' ) {
3490
3491 # Fallen off the end already.
3492 if (!$DB::term) {
3493 DB::setterm();
3494 }
3495
3496 DB::print_help(<<EOP);
3497Debugged program terminated. Use B<q> to quit or B<R> to restart,
3498use B<o> I<inhibit_exit> to avoid stopping after program termination,
3499B<h q>, B<h R> or B<h o> to get additional info.
3500EOP
3501
3502 # Set the DB::eval context appropriately.
3503 $DB::package = 'main';
3504 $DB::usercontext = DB::_calc_usercontext($DB::package);
3505 } ## end elsif ($package eq 'DB::fake')
3506
3507=pod
3508
3509If the program hasn't finished executing, we scan forward to the
3510next executable line, print that out, build the prompt from the file and line
3511number information, and print that.
3512
3513=cut
3514
3515 else {
3516
3517
3518 # Still somewhere in the midst of execution. Set up the
3519 # debugger prompt.
3520 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3521 # Perl 5 ones (sorry, we don't print Klingon
3522 #module names)
3523
3524 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3525 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3526 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3527
3528 # Break up the prompt if it's really long.
3529 if ( length($self->prefix()) > 30 ) {
18b5b545 3530 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3531 $self->prefix("");
3532 $self->infix(":\t");
3533 }
3534 else {
3535 $self->infix("):\t");
3536 $self->position(
18b5b545 3537 $self->prefix . $line. $self->infix
44a07e3e 3538 . $self->_curr_line . $self->after
22fc883d
SF
3539 );
3540 }
3541
3542 # Print current line info, indenting if necessary.
18b5b545 3543 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3544
44a07e3e
SF
3545 my $i;
3546 my $line_i = sub { return $DB::dbline[$i]; };
3547
22fc883d
SF
3548 # Scan forward, stopping at either the end or the next
3549 # unbreakable line.
18b5b545 3550 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3551 { #{ vi
3552
3553 # Drop out on null statements, block closers, and comments.
44a07e3e 3554 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3555
3556 # Drop out if the user interrupted us.
ebd0282e 3557 last if $signal;
22fc883d
SF
3558
3559 # Append a newline if the line doesn't have one. Can happen
3560 # in eval'ed text, for instance.
44a07e3e 3561 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3562
3563 # Next executable line.
44a07e3e 3564 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3565 . $self->after;
8def6eff 3566 $self->append_to_position($incr_pos);
ad46ac70 3567 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3568 } ## end for ($i = $line + 1 ; $i...
3569 } ## end else [ if ($slave_editor)
3570
3571 return;
3572}
3573
174f9c5e
SF