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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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5
6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
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
c7e68384 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
b5afd346 526$VERSION = '1.39_04';
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
638 $evalarg
639 $filename
640 $frame
641 $hist
642 $histfile
643 $histsize
644 $ImmediateStop
645 $IN
646 $inhibit_exit
647 @ini_INC
648 $ini_warn
649 $line
650 $maxtrace
651 $od
652 $onetimeDump
653 $onetimedumpDepth
654 %option
655 @options
656 $osingle
657 $otrace
658 $OUT
659 $packname
660 $pager
661 $post
662 %postponed
663 $prc
664 $pre
665 $pretype
666 $psh
667 @RememberOnROptions
668 $remoteport
669 @res
670 $rl
671 @saved
672 $signal
673 $signalLevel
674 $single
675 $start
676 $sub
677 %sub
678 $subname
679 $term
680 $trace
681 $usercontext
682 $warnLevel
683 $window
684);
685
686# Used to save @ARGV and extract any debugger-related flags.
687use vars qw(@ARGS);
688
689# Used to prevent multiple entries to diesignal()
690# (if for instance diesignal() itself dies)
691use vars qw($panic);
692
693# Used to prevent the debugger from running nonstop
694# after a restart
695use vars qw($second_time);
696
697sub _calc_usercontext {
698 my ($package) = @_;
699
700 # Cancel strict completely for the evaluated code, so the code
701 # the user evaluates won't be affected by it. (Shlomi Fish)
702 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @saved;'
703 . "package $package;"; # this won't let them modify, alas
704}
705
c1051fcf 706sub eval {
69893cff 707
c1051fcf 708 # 'my' would make it visible from user code
e22ea7cc 709 # but so does local! --tchrist
69893cff 710 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
711 local @res;
712 {
e22ea7cc
RF
713
714 # Try to keep the user code from messing with us. Save these so that
715 # even if the eval'ed code changes them, we can put them back again.
716 # Needed because the user could refer directly to the debugger's
69893cff
RGS
717 # package globals (and any 'my' variables in this containing scope)
718 # inside the eval(), and we want to try to stay safe.
e22ea7cc 719 local $otrace = $trace;
69893cff
RGS
720 local $osingle = $single;
721 local $od = $^D;
722
723 # Untaint the incoming eval() argument.
724 { ($evalarg) = $evalarg =~ /(.*)/s; }
725
e22ea7cc 726 # $usercontext built in DB::DB near the comment
69893cff
RGS
727 # "set up the context for DB::eval ..."
728 # Evaluate and save any results.
e22ea7cc 729 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
730
731 # Restore those old values.
732 $trace = $otrace;
733 $single = $osingle;
734 $^D = $od;
c1051fcf 735 }
69893cff
RGS
736
737 # Save the current value of $@, and preserve it in the debugger's copy
738 # of the saved precious globals.
c1051fcf 739 my $at = $@;
69893cff
RGS
740
741 # Since we're only saving $@, we only have to localize the array element
742 # that it will be stored in.
e22ea7cc 743 local $saved[0]; # Preserve the old value of $@
c1051fcf 744 eval { &DB::save };
69893cff
RGS
745
746 # Now see whether we need to report an error back to the user.
c1051fcf 747 if ($at) {
69893cff
RGS
748 local $\ = '';
749 print $OUT $at;
750 }
751
752 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
753 # are package globals.
754 elsif ($onetimeDump) {
e22ea7cc
RF
755 if ( $onetimeDump eq 'dump' ) {
756 local $option{dumpDepth} = $onetimedumpDepth
757 if defined $onetimedumpDepth;
758 dumpit( $OUT, \@res );
759 }
760 elsif ( $onetimeDump eq 'methods' ) {
761 methods( $res[0] );
762 }
69893cff 763 } ## end elsif ($onetimeDump)
c1051fcf 764 @res;
69893cff
RGS
765} ## end sub eval
766
767############################################## End lexical danger zone
c1051fcf 768
e22ea7cc
RF
769# After this point it is safe to introduce lexicals.
770# The code being debugged will be executing in its own context, and
69893cff 771# can't see the inside of the debugger.
d338d6fe 772#
e22ea7cc 773# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
774# possible. If you make something a lexical, it's not going to be addressable
775# from outside the debugger even if you know its name.
776
d338d6fe
PP
777# This file is automatically included if you do perl -d.
778# It's probably not useful to include this yourself.
779#
e22ea7cc 780# Before venturing further into these twisty passages, it is
2f7e9187
MS
781# wise to read the perldebguts man page or risk the ire of dragons.
782#
69893cff
RGS
783# (It should be noted that perldebguts will tell you a lot about
784# the underlying mechanics of how the debugger interfaces into the
785# Perl interpreter, but not a lot about the debugger itself. The new
786# comments in this code try to address this problem.)
787
d338d6fe 788# Note that no subroutine call is possible until &DB::sub is defined
36477c24 789# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 790# true if $deep is not defined.
055fd3a9
GS
791
792# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
793
794# modified Perl debugger, to be run from Emacs in perldb-mode
795# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
796# Johan Vromans -- upgrade to 4.0 pl 10
797# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 798########################################################################
d338d6fe 799
69893cff
RGS
800=head1 DEBUGGER INITIALIZATION
801
802The debugger starts up in phases.
803
804=head2 BASIC SETUP
805
806First, it initializes the environment it wants to run in: turning off
807warnings during its own compilation, defining variables which it will need
808to avoid warnings later, setting itself up to not exit when the program
809terminates, and defaulting to printing return values for the C<r> command.
810
811=cut
812
eda6e075 813# Needed for the statement after exec():
69893cff
RGS
814#
815# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 816# compilation. Probably it would be better practice to fix the warnings,
69893cff 817# but this is how it's done at the moment.
eda6e075 818
e22ea7cc
RF
819BEGIN {
820 $ini_warn = $^W;
821 $^W = 0;
822} # Switch compilation warnings off until another BEGIN.
d12a4851 823
69893cff
RGS
824local ($^W) = 0; # Switch run-time warnings off during init.
825
2cbb2ee1
RGS
826=head2 THREADS SUPPORT
827
828If we are running under a threaded Perl, we require threads and threads::shared
829if the environment variable C<PERL5DB_THREADED> is set, to enable proper
830threaded debugger control. C<-dt> can also be used to set this.
831
832Each new thread will be announced and the debugger prompt will always inform
833you of each new thread created. It will also indicate the thread id in which
834we are currently running within the prompt like this:
835
836 [tid] DB<$i>
837
838Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
839command prompt. The prompt will show: C<[0]> when running under threads, but
840not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
841
842While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 843will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
844in a currently executing thread, you will stay there until it completes. With
845the current implementation it is not currently possible to hop from one thread
846to another.
847
848The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
849
850Note that threading support was built into the debugger as of Perl version
851C<5.8.6> and debugger version C<1.2.8>.
852
853=cut
854
855BEGIN {
856 # ensure we can share our non-threaded variables or no-op
857 if ($ENV{PERL5DB_THREADED}) {
858 require threads;
859 require threads::shared;
860 import threads::shared qw(share);
861 $DBGR;
862 share(\$DBGR);
863 lock($DBGR);
864 print "Threads support enabled\n";
865 } else {
866 *lock = sub(*) {};
867 *share = sub(*) {};
868 }
869}
870
69893cff
RGS
871# This would probably be better done with "use vars", but that wasn't around
872# when this code was originally written. (Neither was "use strict".) And on
873# the principle of not fiddling with something that was working, this was
874# left alone.
875warn( # Do not ;-)
2cbb2ee1 876 # These variables control the execution of 'dumpvar.pl'.
69893cff
RGS
877 $dumpvar::hashDepth,
878 $dumpvar::arrayDepth,
879 $dumpvar::dumpDBFiles,
880 $dumpvar::dumpPackages,
881 $dumpvar::quoteHighBit,
882 $dumpvar::printUndef,
883 $dumpvar::globPrint,
884 $dumpvar::usageOnly,
885
69893cff
RGS
886 # used to control die() reporting in diesignal()
887 $Carp::CarpLevel,
888
69893cff 889
69893cff
RGS
890 )
891 if 0;
d338d6fe 892
422c59bf 893# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 894foreach my $k (keys (%INC)) {
bc6438f2 895 &share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
896};
897
54d04a52 898# Command-line + PERLLIB:
69893cff 899# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
900@ini_INC = @INC;
901
69893cff
RGS
902# This was an attempt to clear out the previous values of various
903# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
904# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
905
69893cff
RGS
906# We set these variables to safe values. We don't want to blindly turn
907# off warnings, because other packages may still want them.
e22ea7cc
RF
908$trace = $signal = $single = 0; # Uninitialized warning suppression
909 # (local $^W cannot help - other packages!).
69893cff
RGS
910
911# Default to not exiting when program finishes; print the return
912# value when the 'r' command is used to return from a subroutine.
55497cff 913$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 914
6b24a4b7
SF
915use vars qw($trace_to_depth);
916
5e2b42dd
SF
917# Default to 1E9 so it won't be limited to a certain recursion depth.
918$trace_to_depth = 1E9;
bdba49ad 919
69893cff
RGS
920=head1 OPTION PROCESSING
921
b570d64b
SF
922The debugger's options are actually spread out over the debugger itself and
923C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
924subs to be called with a value. To try to make this a little easier to
925manage, the debugger uses a few data structures to define what options
926are legal and how they are to be processed.
927
928First, the C<@options> array defines the I<names> of all the options that
929are to be accepted.
930
931=cut
932
933@options = qw(
5561b870 934 CommandSet HistFile HistSize
e22ea7cc
RF
935 hashDepth arrayDepth dumpDepth
936 DumpDBFiles DumpPackages DumpReused
937 compactDump veryCompact quote
938 HighBit undefPrint globPrint
939 PrintRet UsageOnly frame
940 AutoTrace TTY noTTY
941 ReadLine NonStop LineInfo
942 maxTraceLen recallCommand ShellBang
943 pager tkRunning ornaments
944 signalLevel warnLevel dieLevel
945 inhibit_exit ImmediateStop bareStringify
946 CreateTTY RemotePort windowSize
584420f0 947 DollarCaretP
e22ea7cc 948);
d12a4851 949
584420f0 950@RememberOnROptions = qw(DollarCaretP);
d12a4851 951
69893cff
RGS
952=pod
953
954Second, C<optionVars> lists the variables that each option uses to save its
955state.
956
957=cut
958
6b24a4b7
SF
959use vars qw(%optionVars);
960
69893cff 961%optionVars = (
e22ea7cc
RF
962 hashDepth => \$dumpvar::hashDepth,
963 arrayDepth => \$dumpvar::arrayDepth,
964 CommandSet => \$CommandSet,
965 DumpDBFiles => \$dumpvar::dumpDBFiles,
966 DumpPackages => \$dumpvar::dumpPackages,
967 DumpReused => \$dumpvar::dumpReused,
968 HighBit => \$dumpvar::quoteHighBit,
969 undefPrint => \$dumpvar::printUndef,
970 globPrint => \$dumpvar::globPrint,
971 UsageOnly => \$dumpvar::usageOnly,
972 CreateTTY => \$CreateTTY,
973 bareStringify => \$dumpvar::bareStringify,
974 frame => \$frame,
975 AutoTrace => \$trace,
976 inhibit_exit => \$inhibit_exit,
977 maxTraceLen => \$maxtrace,
978 ImmediateStop => \$ImmediateStop,
979 RemotePort => \$remoteport,
980 windowSize => \$window,
5561b870
AK
981 HistFile => \$histfile,
982 HistSize => \$histsize,
69893cff
RGS
983);
984
985=pod
986
987Third, C<%optionAction> defines the subroutine to be called to process each
988option.
989
b570d64b 990=cut
69893cff 991
6b24a4b7
SF
992use vars qw(%optionAction);
993
69893cff
RGS
994%optionAction = (
995 compactDump => \&dumpvar::compactDump,
996 veryCompact => \&dumpvar::veryCompact,
997 quote => \&dumpvar::quote,
998 TTY => \&TTY,
999 noTTY => \&noTTY,
1000 ReadLine => \&ReadLine,
1001 NonStop => \&NonStop,
1002 LineInfo => \&LineInfo,
1003 recallCommand => \&recallCommand,
1004 ShellBang => \&shellBang,
1005 pager => \&pager,
1006 signalLevel => \&signalLevel,
1007 warnLevel => \&warnLevel,
1008 dieLevel => \&dieLevel,
1009 tkRunning => \&tkRunning,
1010 ornaments => \&ornaments,
1011 RemotePort => \&RemotePort,
1012 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1013);
1014
69893cff
RGS
1015=pod
1016
1017Last, the C<%optionRequire> notes modules that must be C<require>d if an
1018option is used.
1019
1020=cut
d338d6fe 1021
69893cff
RGS
1022# Note that this list is not complete: several options not listed here
1023# actually require that dumpvar.pl be loaded for them to work, but are
1024# not in the table. A subsequent patch will correct this problem; for
1025# the moment, we're just recommenting, and we are NOT going to change
1026# function.
6b24a4b7
SF
1027use vars qw(%optionRequire);
1028
eda6e075 1029%optionRequire = (
69893cff
RGS
1030 compactDump => 'dumpvar.pl',
1031 veryCompact => 'dumpvar.pl',
1032 quote => 'dumpvar.pl',
e22ea7cc 1033);
69893cff
RGS
1034
1035=pod
1036
1037There are a number of initialization-related variables which can be set
1038by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1039variable. These are:
1040
1041=over 4
1042
1043=item C<$rl> - readline control XXX needs more explanation
1044
1045=item C<$warnLevel> - whether or not debugger takes over warning handling
1046
1047=item C<$dieLevel> - whether or not debugger takes over die handling
1048
1049=item C<$signalLevel> - whether or not debugger takes over signal handling
1050
1051=item C<$pre> - preprompt actions (array reference)
1052
1053=item C<$post> - postprompt actions (array reference)
1054
1055=item C<$pretype>
1056
1057=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1058
1059=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1060
1061=back
1062
1063=cut
d338d6fe
PP
1064
1065# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1066$rl = 1 unless defined $rl;
1067$warnLevel = 1 unless defined $warnLevel;
1068$dieLevel = 1 unless defined $dieLevel;
1069$signalLevel = 1 unless defined $signalLevel;
1070$pre = [] unless defined $pre;
1071$post = [] unless defined $post;
1072$pretype = [] unless defined $pretype;
1073$CreateTTY = 3 unless defined $CreateTTY;
1074$CommandSet = '580' unless defined $CommandSet;
1075
2cbb2ee1
RGS
1076share($rl);
1077share($warnLevel);
1078share($dieLevel);
1079share($signalLevel);
1080share($pre);
1081share($post);
1082share($pretype);
1083share($rl);
1084share($CreateTTY);
1085share($CommandSet);
1086
69893cff
RGS
1087=pod
1088
1089The default C<die>, C<warn>, and C<signal> handlers are set up.
1090
1091=cut
055fd3a9 1092
d338d6fe
PP
1093warnLevel($warnLevel);
1094dieLevel($dieLevel);
1095signalLevel($signalLevel);
055fd3a9 1096
69893cff
RGS
1097=pod
1098
1099The pager to be used is needed next. We try to get it from the
5561b870 1100environment first. If it's not defined there, we try to find it in
69893cff
RGS
1101the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1102then call the C<pager()> function to save the pager name.
1103
1104=cut
1105
1106# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1107pager(
e22ea7cc 1108
69893cff 1109 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1110 defined $ENV{PAGER}
1111 ? $ENV{PAGER}
69893cff
RGS
1112
1113 # If not, see if Config.pm defines it.
e22ea7cc
RF
1114 : eval { require Config }
1115 && defined $Config::Config{pager}
1116 ? $Config::Config{pager}
69893cff
RGS
1117
1118 # If not, fall back to 'more'.
e22ea7cc
RF
1119 : 'more'
1120 )
1121 unless defined $pager;
69893cff
RGS
1122
1123=pod
1124
1125We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1126recall character (C<!> unless otherwise defined) and the shell escape
1127character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1128neither works in the debugger at the moment.
1129
1130=cut
1131
055fd3a9 1132setman();
69893cff
RGS
1133
1134# Set up defaults for command recall and shell escape (note:
1135# these currently don't work in linemode debugging).
d338d6fe 1136&recallCommand("!") unless defined $prc;
69893cff
RGS
1137&shellBang("!") unless defined $psh;
1138
1139=pod
1140
1141We then set up the gigantic string containing the debugger help.
1142We also set the limit on the number of arguments we'll display during a
1143trace.
1144
1145=cut
1146
04e43a21 1147sethelp();
69893cff
RGS
1148
1149# If we didn't get a default for the length of eval/stack trace args,
1150# set it here.
1d06cb2d 1151$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1152
1153=head2 SETTING UP THE DEBUGGER GREETING
1154
be9a9b1d 1155The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1156running, and whether the current debugger is the primary or a child.
1157
1158If we are the primary, we just hang onto our pid so we'll have it when
1159or if we start a child debugger. If we are a child, we'll set things up
1160so we'll have a unique greeting and so the parent will give us our own
1161TTY later.
1162
1163We save the current contents of the C<PERLDB_PIDS> environment variable
1164because we mess around with it. We'll also need to hang onto it because
1165we'll need it if we restart.
1166
1167Child debuggers make a label out of the current PID structure recorded in
1168PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1169yet so the parent will give them one later via C<resetterm()>.
1170
1171=cut
1172
e22ea7cc 1173# Save the current contents of the environment; we're about to
69893cff 1174# much with it. We'll need this if we have to restart.
6b24a4b7 1175use vars qw($ini_pids);
f1583d8f 1176$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1177
6b24a4b7
SF
1178use vars qw ($pids $term_pid);
1179
e22ea7cc
RF
1180if ( defined $ENV{PERLDB_PIDS} ) {
1181
69893cff 1182 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1183 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1184 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1185
1186 my $env_pids = $ENV{PERLDB_PIDS};
1187 $pids = "[$env_pids]";
1188
1189 # Unless we are on OpenVMS, all programs under the DCL shell run under
1190 # the same PID.
1191
1192 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1193 $term_pid = $$;
1194 }
1195 else {
1196 $ENV{PERLDB_PIDS} .= "->$$";
1197 $term_pid = -1;
1198 }
1199
69893cff
RGS
1200} ## end if (defined $ENV{PERLDB_PIDS...
1201else {
e22ea7cc
RF
1202
1203 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1204 # child debugger, and mark us as the parent, so we'll know to set up
1205 # more TTY's is we have to.
1206 $ENV{PERLDB_PIDS} = "$$";
619a0444 1207 $pids = "[pid=$$]";
e22ea7cc 1208 $term_pid = $$;
f1583d8f 1209}
69893cff 1210
6b24a4b7 1211use vars qw($pidprompt);
f1583d8f 1212$pidprompt = '';
69893cff
RGS
1213
1214# Sets up $emacs as a synonym for $slave_editor.
6b24a4b7 1215use vars qw($slave_editor);
69893cff
RGS
1216*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1217
1218=head2 READING THE RC FILE
1219
b570d64b 1220The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1221running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1222
b570d64b 1223=cut
69893cff
RGS
1224
1225# As noted, this test really doesn't check accurately that the debugger
1226# is running at a terminal or not.
d338d6fe 1227
98274836
JM
1228my $dev_tty = '/dev/tty';
1229 $dev_tty = 'TT:' if ($^O eq 'VMS');
6b24a4b7 1230use vars qw($rcfile);
98274836 1231if ( -e $dev_tty ) { # this is the wrong metric!
e22ea7cc
RF
1232 $rcfile = ".perldb";
1233}
69893cff
RGS
1234else {
1235 $rcfile = "perldb.ini";
d338d6fe
PP
1236}
1237
69893cff
RGS
1238=pod
1239
1240The debugger does a safety test of the file to be read. It must be owned
1241either by the current user or root, and must only be writable by the owner.
1242
1243=cut
1244
1245# This wraps a safety test around "do" to read and evaluate the init file.
1246#
055fd3a9
GS
1247# This isn't really safe, because there's a race
1248# between checking and opening. The solution is to
1249# open and fstat the handle, but then you have to read and
1250# eval the contents. But then the silly thing gets
69893cff
RGS
1251# your lexical scope, which is unfortunate at best.
1252sub safe_do {
055fd3a9
GS
1253 my $file = shift;
1254
1255 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1256 local $SIG{__WARN__};
1257 local $SIG{__DIE__};
055fd3a9 1258
e22ea7cc 1259 unless ( is_safe_file($file) ) {
69893cff 1260 CORE::warn <<EO_GRIPE;
055fd3a9 1261perldb: Must not source insecure rcfile $file.
b570d64b 1262 You or the superuser must be the owner, and it must not
69893cff 1263 be writable by anyone but its owner.
055fd3a9 1264EO_GRIPE
69893cff
RGS
1265 return;
1266 } ## end unless (is_safe_file($file...
055fd3a9
GS
1267
1268 do $file;
1269 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1270} ## end sub safe_do
055fd3a9 1271
69893cff
RGS
1272# This is the safety test itself.
1273#
055fd3a9
GS
1274# Verifies that owner is either real user or superuser and that no
1275# one but owner may write to it. This function is of limited use
1276# when called on a path instead of upon a handle, because there are
1277# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1278# eventually accessed is the same as the one tested.
055fd3a9
GS
1279# Assumes that the file's existence is not in doubt.
1280sub is_safe_file {
1281 my $path = shift;
69893cff 1282 stat($path) || return; # mysteriously vaporized
e22ea7cc 1283 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1284
1285 return 0 if $uid != 0 && $uid != $<;
1286 return 0 if $mode & 022;
1287 return 1;
69893cff 1288} ## end sub is_safe_file
055fd3a9 1289
69893cff 1290# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1291# exists, we safely do it.
1292if ( -f $rcfile ) {
055fd3a9 1293 safe_do("./$rcfile");
69893cff 1294}
e22ea7cc 1295
69893cff 1296# If there isn't one here, try the user's home directory.
e22ea7cc 1297elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1298 safe_do("$ENV{HOME}/$rcfile");
1299}
e22ea7cc 1300
69893cff 1301# Else try the login directory.
e22ea7cc 1302elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1303 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1304}
1305
69893cff 1306# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1307if ( defined $ENV{PERLDB_OPTS} ) {
1308 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1309}
1310
69893cff
RGS
1311=pod
1312
1313The last thing we do during initialization is determine which subroutine is
1314to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1315the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1316(darwin).
69893cff
RGS
1317
1318=cut
1319
1320# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1321# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1322# OS/2, or on Mac OS X. This may need some expansion.
1323
1324if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1325{
b570d64b 1326 if ( defined $remoteport ) {
11653f7f
JJ
1327 # Expect an inetd-like server
1328 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1329 }
1330 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1331 # of terminal this is,
1332 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1333 and defined $ENV{DISPLAY} # and what display it's on,
1334 )
1335 {
1336 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1337 }
1338 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1339 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1340 }
1341 elsif ( $^O eq 'darwin' # If this is Mac OS X
1342 and defined $ENV{TERM_PROGRAM} # and we're running inside
1343 and $ENV{TERM_PROGRAM}
1344 eq 'Apple_Terminal' # Terminal.app
1345 )
1346 {
1347 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1348 }
69893cff 1349} ## end if (not defined &get_fork_TTY...
e22ea7cc 1350
dbb46cec
DQ
1351# untaint $^O, which may have been tainted by the last statement.
1352# see bug [perl #24674]
e22ea7cc
RF
1353$^O =~ m/^(.*)\z/;
1354$^O = $1;
f1583d8f 1355
d12a4851 1356# Here begin the unreadable code. It needs fixing.
055fd3a9 1357
69893cff
RGS
1358=head2 RESTART PROCESSING
1359
1360This section handles the restart command. When the C<R> command is invoked, it
1361tries to capture all of the state it can into environment variables, and
1362then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1363if C<PERLDB_RESTART> is there; if so, we reload all the information that
1364the R command stuffed into the environment variables.
1365
b570d64b 1366 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1367 PERLDB_HIST - command history, if it's available
1368 PERLDB_ON_LOAD - breakpoints set by the rc file
1369 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1370 PERLDB_VISITED - files that had breakpoints
1371 PERLDB_FILE_... - breakpoints for a file
1372 PERLDB_OPT - active options
1373 PERLDB_INC - the original @INC
1374 PERLDB_PRETYPE - preprompt debugger actions
1375 PERLDB_PRE - preprompt Perl code
1376 PERLDB_POST - post-prompt Perl code
1377 PERLDB_TYPEAHEAD - typeahead captured by readline()
1378
1379We chug through all these variables and plug the values saved in them
1380back into the appropriate spots in the debugger.
1381
1382=cut
1383
6b24a4b7
SF
1384use vars qw(@hist @truehist %postponed_file @typeahead);
1385
e22ea7cc
RF
1386if ( exists $ENV{PERLDB_RESTART} ) {
1387
69893cff 1388 # We're restarting, so we don't need the flag that says to restart anymore.
e22ea7cc
RF
1389 delete $ENV{PERLDB_RESTART};
1390
1391 # $restart = 1;
1392 @hist = get_list('PERLDB_HIST');
1393 %break_on_load = get_list("PERLDB_ON_LOAD");
1394 %postponed = get_list("PERLDB_POSTPONE");
69893cff 1395
2cbb2ee1
RGS
1396 share(@hist);
1397 share(@truehist);
1398 share(%break_on_load);
1399 share(%postponed);
1400
69893cff 1401 # restore breakpoints/actions
e22ea7cc 1402 my @had_breakpoints = get_list("PERLDB_VISITED");
bdba49ad
SF
1403 for my $file_idx ( 0 .. $#had_breakpoints ) {
1404 my $filename = $had_breakpoints[$file_idx];
1405 my %pf = get_list("PERLDB_FILE_$file_idx");
1406 $postponed_file{ $filename } = \%pf if %pf;
1407 my @lines = sort {$a <=> $b} keys(%pf);
1408 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1409 for my $line_idx (0 .. $#lines) {
1410 _set_breakpoint_enabled_status(
1411 $filename,
1412 $lines[$line_idx],
1413 ($enabled_statuses[$line_idx] ? 1 : ''),
1414 );
1415 }
e22ea7cc 1416 }
69893cff
RGS
1417
1418 # restore options
e22ea7cc
RF
1419 my %opt = get_list("PERLDB_OPT");
1420 my ( $opt, $val );
1421 while ( ( $opt, $val ) = each %opt ) {
1422 $val =~ s/[\\\']/\\$1/g;
1423 parse_options("$opt'$val'");
1424 }
69893cff
RGS
1425
1426 # restore original @INC
e22ea7cc
RF
1427 @INC = get_list("PERLDB_INC");
1428 @ini_INC = @INC;
1429
1430 # return pre/postprompt actions and typeahead buffer
1431 $pretype = [ get_list("PERLDB_PRETYPE") ];
1432 $pre = [ get_list("PERLDB_PRE") ];
1433 $post = [ get_list("PERLDB_POST") ];
1434 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1435} ## end if (exists $ENV{PERLDB_RESTART...
1436
1437=head2 SETTING UP THE TERMINAL
1438
1439Now, we'll decide how the debugger is going to interact with the user.
1440If there's no TTY, we set the debugger to run non-stop; there's not going
1441to be anyone there to enter commands.
1442
1443=cut
54d04a52 1444
6b24a4b7
SF
1445use vars qw($notty $runnonstop $console $tty $LINEINFO);
1446use vars qw($lineinfo $doccmd);
1447
d338d6fe 1448if ($notty) {
69893cff 1449 $runnonstop = 1;
2cbb2ee1 1450 share($runnonstop);
69893cff 1451}
d12a4851 1452
69893cff
RGS
1453=pod
1454
1455If there is a TTY, we have to determine who it belongs to before we can
1456proceed. If this is a slave editor or graphical debugger (denoted by
1457the first command-line switch being '-emacs'), we shift this off and
1458set C<$rl> to 0 (XXX ostensibly to do straight reads).
1459
1460=cut
1461
1462else {
e22ea7cc 1463
69893cff
RGS
1464 # Is Perl being run from a slave editor or graphical debugger?
1465 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1466 $slave_editor =
1467 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1468 $rl = 0, shift(@main::ARGV) if $slave_editor;
1469
1470 #require Term::ReadLine;
d12a4851 1471
69893cff
RGS
1472=pod
1473
1474We then determine what the console should be on various systems:
1475
1476=over 4
1477
1478=item * Cygwin - We use C<stdin> instead of a separate device.
1479
1480=cut
1481
e22ea7cc
RF
1482 if ( $^O eq 'cygwin' ) {
1483
69893cff
RGS
1484 # /dev/tty is binary. use stdin for textmode
1485 undef $console;
1486 }
1487
1488=item * Unix - use C</dev/tty>.
1489
1490=cut
1491
e22ea7cc 1492 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1493 $console = "/dev/tty";
1494 }
1495
1496=item * Windows or MSDOS - use C<con>.
1497
1498=cut
1499
e22ea7cc 1500 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1501 $console = "con";
1502 }
1503
69893cff
RGS
1504=item * VMS - use C<sys$command>.
1505
1506=cut
1507
1508 else {
e22ea7cc 1509
69893cff
RGS
1510 # everything else is ...
1511 $console = "sys\$command";
d12a4851 1512 }
69893cff
RGS
1513
1514=pod
1515
1516=back
1517
1518Several other systems don't use a specific console. We C<undef $console>
1519for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1520with a slave editor, Epoc).
1521
1522=cut
d12a4851 1523
e22ea7cc
RF
1524 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1525
69893cff 1526 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1527 $console = undef;
1528 }
1529
1530 if ( $^O eq 'NetWare' ) {
d12a4851 1531
69893cff
RGS
1532 # /dev/tty is binary. use stdin for textmode
1533 $console = undef;
1534 }
d12a4851 1535
69893cff
RGS
1536 # In OS/2, we need to use STDIN to get textmode too, even though
1537 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1538 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1539 { # In OS/2
1540 $console = undef;
1541 }
1542
1543 # EPOC also falls into the 'got to use STDIN' camp.
1544 if ( $^O eq 'epoc' ) {
1545 $console = undef;
1546 }
d12a4851 1547
69893cff
RGS
1548=pod
1549
1550If there is a TTY hanging around from a parent, we use that as the console.
1551
1552=cut
1553
e22ea7cc 1554 $console = $tty if defined $tty;
d12a4851 1555
b570d64b 1556=head2 SOCKET HANDLING
69893cff
RGS
1557
1558The debugger is capable of opening a socket and carrying out a debugging
1559session over the socket.
1560
1561If C<RemotePort> was defined in the options, the debugger assumes that it
1562should try to start a debugging session on that port. It builds the socket
1563and then tries to connect the input and output filehandles to it.
1564
1565=cut
1566
1567 # Handle socket stuff.
e22ea7cc
RF
1568
1569 if ( defined $remoteport ) {
1570
69893cff
RGS
1571 # If RemotePort was defined in the options, connect input and output
1572 # to the socket.
11653f7f 1573 $IN = $OUT = connect_remoteport();
69893cff
RGS
1574 } ## end if (defined $remoteport)
1575
1576=pod
1577
1578If no C<RemotePort> was defined, and we want to create a TTY on startup,
1579this is probably a situation where multiple debuggers are running (for example,
1580a backticked command that starts up another debugger). We create a new IN and
1581OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1582and if we can.
1583
1584=cut
1585
1586 # Non-socket.
1587 else {
e22ea7cc 1588
69893cff
RGS
1589 # Two debuggers running (probably a system or a backtick that invokes
1590 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1591 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1592 # know how, and we can.
e22ea7cc
RF
1593 create_IN_OUT(4) if $CreateTTY & 4;
1594 if ($console) {
1595
69893cff 1596 # If we have a console, check to see if there are separate ins and
cd1191f1 1597 # outs to open. (They are assumed identical if not.)
69893cff 1598
e22ea7cc
RF
1599 my ( $i, $o ) = split /,/, $console;
1600 $o = $i unless defined $o;
69893cff 1601
69893cff 1602 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1603 open( IN, "+<$i" )
1604 || open( IN, "<$i" )
1605 || open( IN, "<&STDIN" );
1606
69893cff
RGS
1607 # read/write/create/clobber out, or write/create/clobber out,
1608 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1609 open( OUT, "+>$o" )
1610 || open( OUT, ">$o" )
1611 || open( OUT, ">&STDERR" )
1612 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1613
1614 } ## end if ($console)
1615 elsif ( not defined $console ) {
1616
1617 # No console. Open STDIN.
1618 open( IN, "<&STDIN" );
1619
1620 # merge with STDERR, or with STDOUT.
1621 open( OUT, ">&STDERR" )
1622 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1623 $console = 'STDIN/OUT';
69893cff
RGS
1624 } ## end elsif (not defined $console)
1625
1626 # Keep copies of the filehandles so that when the pager runs, it
1627 # can close standard input without clobbering ours.
e22ea7cc
RF
1628 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1629 } ## end elsif (from if(defined $remoteport))
1630
1631 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1632 $OUT->autoflush(1);
e22ea7cc
RF
1633
1634 # Line info goes to debugger output unless pointed elsewhere.
1635 # Pointing elsewhere makes it possible for slave editors to
1636 # keep track of file and position. We have both a filehandle
1637 # and a I/O description to keep track of.
1638 $LINEINFO = $OUT unless defined $LINEINFO;
1639 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1 1640 # share($LINEINFO); # <- unable to share globs
b570d64b 1641 share($lineinfo); #
e22ea7cc 1642
69893cff
RGS
1643=pod
1644
1645To finish initialization, we show the debugger greeting,
1646and then call the C<afterinit()> subroutine if there is one.
1647
1648=cut
d12a4851 1649
e22ea7cc
RF
1650 # Show the debugger greeting.
1651 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1652 unless ($runnonstop) {
1653 local $\ = '';
1654 local $, = '';
1655 if ( $term_pid eq '-1' ) {
1656 print $OUT "\nDaughter DB session started...\n";
1657 }
1658 else {
1659 print $OUT "\nLoading DB routines from $header\n";
1660 print $OUT (
1661 "Editor support ",
1662 $slave_editor ? "enabled" : "available", ".\n"
1663 );
1664 print $OUT
1f874cb6 1665"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1666 } ## end else [ if ($term_pid eq '-1')
1667 } ## end unless ($runnonstop)
1668} ## end else [ if ($notty)
1669
1670# XXX This looks like a bug to me.
1671# Why copy to @ARGS and then futz with @args?
d338d6fe 1672@ARGS = @ARGV;
6b24a4b7 1673# for (@args) {
69893cff
RGS
1674 # Make sure backslashes before single quotes are stripped out, and
1675 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1676 # s/\'/\\\'/g; # removed while not justified understandably
1677 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1678# }
d338d6fe 1679
e22ea7cc 1680# If there was an afterinit() sub defined, call it. It will get
69893cff 1681# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1682if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1683 &afterinit();
d338d6fe 1684}
e22ea7cc 1685
69893cff 1686# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1687use vars qw($I_m_init);
1688
43aed9ee
IZ
1689$I_m_init = 1;
1690
d338d6fe
PP
1691############################################################ Subroutines
1692
69893cff
RGS
1693=head1 SUBROUTINES
1694
1695=head2 DB
1696
1697This gigantic subroutine is the heart of the debugger. Called before every
1698statement, its job is to determine if a breakpoint has been reached, and
1699stop if so; read commands from the user, parse them, and execute
b468dcb6 1700them, and then send execution off to the next statement.
69893cff
RGS
1701
1702Note that the order in which the commands are processed is very important;
1703some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1704to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1705but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1706see what's happening in any given command.
1707
1708=cut
1709
6b24a4b7
SF
1710use vars qw(
1711 $action
1712 %alias
1713 $cmd
1714 $doret
1715 $fall_off_end
1716 $file
1717 $filename_ini
1718 $finished
1719 %had_breakpoints
1720 $incr
1721 $laststep
1722 $level
1723 $max
1724 @old_watch
1725 $package
1726 $rc
1727 $sh
1728 @stack
1729 $stack_depth
1730 @to_watch
1731 $try
2c247e84 1732 $end
6b24a4b7
SF
1733);
1734
d338d6fe 1735sub DB {
69893cff 1736
2cbb2ee1
RGS
1737 # lock the debugger and get the thread id for the prompt
1738 lock($DBGR);
1739 my $tid;
6b24a4b7
SF
1740 my $position;
1741 my ($prefix, $after, $infix);
1742 my $pat;
6b24a4b7 1743
2cbb2ee1 1744 if ($ENV{PERL5DB_THREADED}) {
878090d5 1745 $tid = eval { "[".threads->tid."]" };
2cbb2ee1
RGS
1746 }
1747
69893cff 1748 # Check for whether we should be running continuously or not.
36477c24 1749 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1750 if ( $single and not $second_time++ ) {
1751
69893cff 1752 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1753 if ($runnonstop) { # Disable until signal
1754 # If there's any call stack in place, turn off single
1755 # stepping into subs throughout the stack.
2c247e84 1756 for my $i (0 .. $stack_depth) {
72d7d80d 1757 $stack[ $i ] &= ~1;
e22ea7cc
RF
1758 }
1759
69893cff 1760 # And we are now no longer in single-step mode.
e22ea7cc 1761 $single = 0;
69893cff
RGS
1762
1763 # If we simply returned at this point, we wouldn't get
1764 # the trace info. Fall on through.
e22ea7cc 1765 # return;
69893cff
RGS
1766 } ## end if ($runnonstop)
1767
e22ea7cc
RF
1768 elsif ($ImmediateStop) {
1769
1770 # We are supposed to stop here; XXX probably a break.
1771 $ImmediateStop = 0; # We've processed it; turn it off
1772 $signal = 1; # Simulate an interrupt to force
1773 # us into the command loop
69893cff
RGS
1774 }
1775 } ## end if ($single and not $second_time...
1776
1777 # If we're in single-step mode, or an interrupt (real or fake)
1778 # has occurred, turn off non-stop mode.
1779 $runnonstop = 0 if $single or $signal;
1780
1781 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1782 # The code being debugged may have altered them.
d338d6fe 1783 &save;
69893cff
RGS
1784
1785 # Since DB::DB gets called after every line, we can use caller() to
1786 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1787 # caller is returning all the extra information when called from the
69893cff 1788 # debugger.
e22ea7cc 1789 local ( $package, $filename, $line ) = caller;
6b24a4b7 1790 $filename_ini = $filename;
69893cff
RGS
1791
1792 # set up the context for DB::eval, so it can properly execute
1793 # code on behalf of the user. We add the package in so that the
1794 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1795 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1796
1797 # Create an alias to the active file magical array to simplify
1798 # the code here.
e22ea7cc 1799 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1800
69893cff 1801 # Last line in the program.
55783941 1802 $max = $#dbline;
69893cff
RGS
1803
1804 # if we have something here, see if we should break.
e22ea7cc 1805 {
72d7d80d
SF
1806 # $stop is lexical and local to this block - $action on the other hand
1807 # is global.
1808 my $stop;
e22ea7cc 1809
72d7d80d
SF
1810 if ( $dbline{$line}
1811 && _is_breakpoint_enabled($filename, $line)
1812 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1813 {
e22ea7cc 1814
72d7d80d
SF
1815 # Stop if the stop criterion says to just stop.
1816 if ( $stop eq '1' ) {
1817 $signal |= 1;
5d5d9ea3 1818 }
72d7d80d
SF
1819
1820 # It's a conditional stop; eval it in the user's context and
1821 # see if we should stop. If so, remove the one-time sigil.
1822 elsif ($stop) {
1823 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1824 &eval;
1825 # If the breakpoint is temporary, then delete its enabled status.
1826 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1827 _cancel_breakpoint_temp_enabled_status($filename, $line);
1828 }
1829 }
1830 } ## end if ($dbline{$line} && ...
1831 }
69893cff
RGS
1832
1833 # Preserve the current stop-or-not, and see if any of the W
1834 # (watch expressions) has changed.
36477c24 1835 my $was_signal = $signal;
69893cff
RGS
1836
1837 # If we have any watch expressions ...
e22ea7cc 1838 if ( $trace & 2 ) {
2c247e84 1839 for my $n (0 .. $#to_watch) {
e22ea7cc
RF
1840 $evalarg = $to_watch[$n];
1841 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1842
1843 # Fix context DB::eval() wants to return an array, but
1844 # we need a scalar here.
e22ea7cc
RF
1845 my ($val) = join( "', '", &eval );
1846 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1847
1848 # Did it change?
e22ea7cc
RF
1849 if ( $val ne $old_watch[$n] ) {
1850
69893cff 1851 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1852 $signal = 1;
1853 print $OUT <<EOP;
405ff068 1854Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1855 old value:\t$old_watch[$n]
1856 new value:\t$val
6027b9a3 1857EOP
e22ea7cc 1858 $old_watch[$n] = $val;
69893cff 1859 } ## end if ($val ne $old_watch...
2c247e84 1860 } ## end for my $n (0 ..
69893cff
RGS
1861 } ## end if ($trace & 2)
1862
1863=head2 C<watchfunction()>
1864
1865C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1866function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1867current package, filename, and line as its parameters.
1868
b570d64b 1869The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1870debugger's context, so it has access to all of the debugger's internal
1871data structures and functions.
1872
1873C<watchfunction()> can control the debugger's actions. Any of the following
1874will cause the debugger to return control to the user's program after
1875C<watchfunction()> executes:
1876
b570d64b 1877=over 4
69893cff 1878
be9a9b1d
AT
1879=item *
1880
1881Returning a false value from the C<watchfunction()> itself.
1882
1883=item *
1884
1885Altering C<$single> to a false value.
1886
1887=item *
69893cff 1888
be9a9b1d 1889Altering C<$signal> to a false value.
69893cff 1890
be9a9b1d 1891=item *
69893cff 1892
be9a9b1d 1893Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1894check for C<watchfunction()>. This can be done with
1895
1896 $trace &= ~4;
1897
1898=back
1899
1900=cut
1901
e22ea7cc 1902 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1903 # current package, filename, and line. The function executes in
1904 # the DB:: package.
e22ea7cc
RF
1905 if ( $trace & 4 ) { # User-installed watch
1906 return
1907 if watchfunction( $package, $filename, $line )
1908 and not $single
1909 and not $was_signal
1910 and not( $trace & ~4 );
69893cff
RGS
1911 } ## end if ($trace & 4)
1912
e22ea7cc 1913 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1914 # turn off the signal now.
6027b9a3 1915 $was_signal = $signal;
69893cff
RGS
1916 $signal = 0;
1917
1918=head2 GETTING READY TO EXECUTE COMMANDS
1919
1920The debugger decides to take control if single-step mode is on, the
1921C<t> command was entered, or the user generated a signal. If the program
1922has fallen off the end, we set things up so that entering further commands
1923won't cause trouble, and we say that the program is over.
1924
1925=cut
1926
8dc67a69
SF
1927 # Make sure that we always print if asked for explicitly regardless
1928 # of $trace_to_depth .
1929 my $explicit_stop = ($single || $was_signal);
1930
69893cff
RGS
1931 # Check to see if we should grab control ($single true,
1932 # trace set appropriately, or we got a signal).
8dc67a69 1933 if ( $explicit_stop || ( $trace & 1 ) ) {
e22ea7cc 1934
69893cff 1935 # Yes, grab control.
e22ea7cc
RF
1936 if ($slave_editor) {
1937
69893cff 1938 # Tell the editor to update its position.
e22ea7cc
RF
1939 $position = "\032\032$filename:$line:0\n";
1940 print_lineinfo($position);
1941 }
69893cff
RGS
1942
1943=pod
1944
b570d64b 1945Special check: if we're in package C<DB::fake>, we've gone through the
69893cff
RGS
1946C<END> block at least once. We set up everything so that we can continue
1947to enter commands and have a valid context to be in.
1948
1949=cut
1950
e22ea7cc 1951 elsif ( $package eq 'DB::fake' ) {
69893cff 1952
69893cff 1953 # Fallen off the end already.
e22ea7cc
RF
1954 $term || &setterm;
1955 print_help(<<EOP);
405ff068 1956Debugged program terminated. Use B<q> to quit or B<R> to restart,
6b27b0a0 1957 use B<o> I<inhibit_exit> to avoid stopping after program termination,
b570d64b 1958 B<h q>, B<h R> or B<h o> to get additional info.
405ff068 1959EOP
e22ea7cc 1960
69893cff 1961 # Set the DB::eval context appropriately.
e22ea7cc 1962 $package = 'main';
6b24a4b7 1963 $usercontext = _calc_usercontext($package);
69893cff 1964 } ## end elsif ($package eq 'DB::fake')
e219e2fb 1965
69893cff 1966=pod
e219e2fb 1967
69893cff
RGS
1968If the program hasn't finished executing, we scan forward to the
1969next executable line, print that out, build the prompt from the file and line
b570d64b 1970number information, and print that.
e219e2fb 1971
69893cff
RGS
1972=cut
1973
e22ea7cc
RF
1974 else {
1975
8dc67a69 1976
69893cff
RGS
1977 # Still somewhere in the midst of execution. Set up the
1978 # debugger prompt.
1979 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 1980 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
1981 #module names)
1982
6b24a4b7 1983 $prefix = $sub =~ /::/ ? "" : ($package . '::');
e22ea7cc
RF
1984 $prefix .= "$sub($filename:";
1985 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
1986
1987 # Break up the prompt if it's really long.
e22ea7cc
RF
1988 if ( length($prefix) > 30 ) {
1989 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
1990 $prefix = "";
1991 $infix = ":\t";
1992 }
1993 else {
1994 $infix = "):\t";
1995 $position = "$prefix$line$infix$dbline[$line]$after";
1996 }
69893cff
RGS
1997
1998 # Print current line info, indenting if necessary.
e22ea7cc
RF
1999 if ($frame) {
2000 print_lineinfo( ' ' x $stack_depth,
2001 "$line:\t$dbline[$line]$after" );
2002 }
2003 else {
8dc67a69 2004 depth_print_lineinfo($explicit_stop, $position);
e22ea7cc 2005 }
69893cff
RGS
2006
2007 # Scan forward, stopping at either the end or the next
2008 # unbreakable line.
72d7d80d 2009 for ( my $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
e22ea7cc 2010 { #{ vi
69893cff
RGS
2011
2012 # Drop out on null statements, block closers, and comments.
2013 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2014
2015 # Drop out if the user interrupted us.
2016 last if $signal;
2017
2018 # Append a newline if the line doesn't have one. Can happen
2019 # in eval'ed text, for instance.
e22ea7cc 2020 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2021
2022 # Next executable line.
6b24a4b7 2023 my $incr_pos = "$prefix$i$infix$dbline[$i]$after";
69893cff
RGS
2024 $position .= $incr_pos;
2025 if ($frame) {
e22ea7cc 2026
69893cff 2027 # Print it indented if tracing is on.
e22ea7cc
RF
2028 print_lineinfo( ' ' x $stack_depth,
2029 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2030 }
2031 else {
8dc67a69 2032 depth_print_lineinfo($explicit_stop, $incr_pos);
69893cff 2033 }
72d7d80d 2034 } ## end for ($i = $line + 1 ; $i...
69893cff
RGS
2035 } ## end else [ if ($slave_editor)
2036 } ## end if ($single || ($trace...
2037
2038=pod
2039
2040If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2041If there are any preprompt actions, execute those as well.
e219e2fb
RF
2042
2043=cut
2044
69893cff
RGS
2045 # If there's an action, do it now.
2046 $evalarg = $action, &eval if $action;
e219e2fb 2047
69893cff
RGS
2048 # Are we nested another level (e.g., did we evaluate a function
2049 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2050 if ( $single || $was_signal ) {
2051
69893cff 2052 # Yes, go down a level.
e22ea7cc 2053 local $level = $level + 1;
69893cff
RGS
2054
2055 # Do any pre-prompt actions.
e22ea7cc
RF
2056 foreach $evalarg (@$pre) {
2057 &eval;
2058 }
69893cff
RGS
2059
2060 # Complain about too much recursion if we passed the limit.
e22ea7cc 2061 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2062 if $single & 4;
2063
2064 # The line we're currently on. Set $incr to -1 to stay here
2065 # until we get a command that tells us to advance.
e22ea7cc
RF
2066 $start = $line;
2067 $incr = -1; # for backward motion.
69893cff
RGS
2068
2069 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2070 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2071
2072=head2 WHERE ARE WE?
2073
2074XXX Relocate this section?
2075
2076The debugger normally shows the line corresponding to the current line of
2077execution. Sometimes, though, we want to see the next line, or to move elsewhere
2078in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2079
be9a9b1d
AT
2080C<$incr> controls by how many lines the I<current> line should move forward
2081after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2082line shouldn't change.
2083
be9a9b1d 2084C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2085move forwards or backwards from when doing an C<L> or C<-> command.
2086
2087C<$max> tells the debugger where the last line of the current file is. It's
2088used to terminate loops most often.
2089
2090=head2 THE COMMAND LOOP
2091
2092Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2093in two parts:
2094
2095=over 4
2096
be9a9b1d
AT
2097=item *
2098
2099The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2100reads a command and then executes it.
2101
be9a9b1d
AT
2102=item *
2103
2104The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2105is wholly contained inside the C<CMD> block and only executes a command.
2106Used to handle commands running inside a pager.
2107
2108=back
2109
2110So why have two labels to restart the loop? Because sometimes, it's easier to
2111have a command I<generate> another command and then re-execute the loop to do
2112the new command. This is faster, but perhaps a bit more convoluted.
2113
2114=cut
2115
2116 # The big command dispatch loop. It keeps running until the
2117 # user yields up control again.
2118 #
2119 # If we have a terminal for input, and we get something back
2120 # from readline(), keep on processing.
6b24a4b7
SF
2121 my $piped;
2122 my $selected;
2123
e22ea7cc
RF
2124 CMD:
2125 while (
2126
69893cff 2127 # We have a terminal, or can get one ...
e22ea7cc
RF
2128 ( $term || &setterm ),
2129
69893cff 2130 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2131 ( $term_pid == $$ or resetterm(1) ),
2132
69893cff 2133 # ... and we got a line of command input ...
e22ea7cc
RF
2134 defined(
2135 $cmd = &readline(
2cbb2ee1 2136 "$pidprompt $tid DB"
e22ea7cc
RF
2137 . ( '<' x $level )
2138 . ( $#hist + 1 )
2139 . ( '>' x $level ) . " "
69893cff
RGS
2140 )
2141 )
2142 )
2143 {
e22ea7cc 2144
2cbb2ee1 2145 share($cmd);
69893cff
RGS
2146 # ... try to execute the input as debugger commands.
2147
2148 # Don't stop running.
2149 $single = 0;
2150
2151 # No signal is active.
2152 $signal = 0;
2153
2154 # Handle continued commands (ending with \):
3d7a2a93 2155 if ($cmd =~ s/\\\z/\n/) {
e22ea7cc
RF
2156 $cmd .= &readline(" cont: ");
2157 redo CMD;
3d7a2a93 2158 }
69893cff
RGS
2159
2160=head4 The null command
2161
be9a9b1d 2162A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2163command out of C<$laststep> (where it was recorded previously), and copy it
2164back into C<$cmd> to be executed below. If there wasn't any previous command,
2165we'll do nothing below (no command will match). If there was, we also save it
2166in the command history and fall through to allow the command parsing to pick
2167it up.
2168
2169=cut
2170
2171 # Empty input means repeat the last command.
e22ea7cc
RF
2172 $cmd =~ /^$/ && ( $cmd = $laststep );
2173 chomp($cmd); # get rid of the annoying extra newline
2174 push( @hist, $cmd ) if length($cmd) > 1;
2175 push( @truehist, $cmd );
2cbb2ee1
RGS
2176 share(@hist);
2177 share(@truehist);
e22ea7cc
RF
2178
2179 # This is a restart point for commands that didn't arrive
2180 # via direct user input. It allows us to 'redo PIPE' to
2181 # re-execute command processing without reading a new command.
69893cff 2182 PIPE: {
e22ea7cc
RF
2183 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2184 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
6b24a4b7 2185 my ($i) = split( /\s+/, $cmd );
69893cff
RGS
2186
2187=head3 COMMAND ALIASES
2188
2189The debugger can create aliases for commands (these are stored in the
2190C<%alias> hash). Before a command is executed, the command loop looks it up
2191in the alias hash and substitutes the contents of the alias for the command,
2192completely replacing it.
2193
2194=cut
2195
2196 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2197 if ( $alias{$i} ) {
2198
69893cff
RGS
2199 # Squelch signal handling; we want to keep control here
2200 # if something goes loco during the alias eval.
2201 local $SIG{__DIE__};
2202 local $SIG{__WARN__};
2203
2204 # This is a command, so we eval it in the DEBUGGER's
2205 # scope! Otherwise, we can't see the special debugger
2206 # variables, or get to the debugger's subs. (Well, we
2207 # _could_, but why make it even more complicated?)
2208 eval "\$cmd =~ $alias{$i}";
2209 if ($@) {
2210 local $\ = '';
1f874cb6 2211 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2212 next CMD;
2213 }
2214 } ## end if ($alias{$i})
2215
2216=head3 MAIN-LINE COMMANDS
2217
2218All of these commands work up to and after the program being debugged has
b570d64b 2219terminated.
69893cff
RGS
2220
2221=head4 C<q> - quit
2222
b570d64b 2223Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2224try to execute further, cleaning any restart-related stuff out of the
2225environment, and executing with the last value of C<$?>.
2226
2227=cut
2228
3d7a2a93 2229 if ($cmd eq 'q') {
69893cff
RGS
2230 $fall_off_end = 1;
2231 clean_ENV();
2232 exit $?;
3d7a2a93 2233 }
69893cff 2234
611272bb 2235=head4 C<t> - trace [n]
69893cff
RGS
2236
2237Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2238If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2239
2240=cut
2241
3d7a2a93 2242 if (my ($levels) = $cmd =~ /\At(?:\s+(\d+))?\z/) {
e22ea7cc
RF
2243 $trace ^= 1;
2244 local $\ = '';
611272bb 2245 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
e22ea7cc 2246 print $OUT "Trace = "
611272bb
PS
2247 . ( ( $trace & 1 )
2248 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2249 : "off" ) . "\n";
e22ea7cc 2250 next CMD;
3d7a2a93 2251 }
69893cff
RGS
2252
2253=head4 C<S> - list subroutines matching/not matching a pattern
2254
2255Walks through C<%sub>, checking to see whether or not to print the name.
2256
2257=cut
2258
826b9a2e
SF
2259 if (my ($print_all_subs, $should_reverse, $Spatt)
2260 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2261 # $Spatt is the pattern (if any) to use.
2262 # Reverse scan?
2263 my $Srev = defined $should_reverse;
2264 # No args - print all subs.
2265 my $Snocheck = !defined $print_all_subs;
69893cff
RGS
2266
2267 # Need to make these sane here.
e22ea7cc
RF
2268 local $\ = '';
2269 local $, = '';
69893cff
RGS
2270
2271 # Search through the debugger's magical hash of subs.
2272 # If $nocheck is true, just print the sub name.
2273 # Otherwise, check it against the pattern. We then use
2274 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2275 foreach $subname ( sort( keys %sub ) ) {
2276 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2277 print $OUT $subname, "\n";
2278 }
2279 }
2280 next CMD;
826b9a2e 2281 }
69893cff
RGS
2282
2283=head4 C<X> - list variables in current package
2284
b570d64b 2285Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2286appropriate C<V> command and fall through.
2287
2288=cut
2289
e22ea7cc 2290 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2291
2292=head4 C<V> - list variables
2293
b570d64b 2294Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2295
2296=cut
2297
2298 # Bare V commands get the currently-being-debugged package
2299 # added.
826b9a2e 2300 if ($cmd eq "V") {
e22ea7cc 2301 $cmd = "V $package";
826b9a2e 2302 }
69893cff
RGS
2303
2304 # V - show variables in package.
826b9a2e
SF
2305 if (my ($new_packname, $new_vars_str) =
2306 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
e22ea7cc 2307
69893cff
RGS
2308 # Save the currently selected filehandle and
2309 # force output to debugger's filehandle (dumpvar
2310 # just does "print" for output).
6b24a4b7 2311 my $savout = select($OUT);
69893cff
RGS
2312
2313 # Grab package name and variables to dump.
826b9a2e
SF
2314 $packname = $new_packname;
2315 my @vars = split( ' ', $new_vars_str );
69893cff
RGS
2316
2317 # If main::dumpvar isn't here, get it.
e81465be 2318 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2319 if ( defined &main::dumpvar ) {
2320
69893cff
RGS
2321 # We got it. Turn off subroutine entry/exit messages
2322 # for the moment, along with return values.
e22ea7cc
RF
2323 local $frame = 0;
2324 local $doret = -2;
69893cff
RGS
2325
2326 # must detect sigpipe failures - not catching
2327 # then will cause the debugger to die.
2328 eval {
2329 &main::dumpvar(
2330 $packname,
2331 defined $option{dumpDepth}
e22ea7cc
RF
2332 ? $option{dumpDepth}
2333 : -1, # assume -1 unless specified
69893cff 2334 @vars
e22ea7cc
RF
2335 );
2336 };
2337
2338 # The die doesn't need to include the $@, because
2339 # it will automatically get propagated for us.
2340 if ($@) {
2341 die unless $@ =~ /dumpvar print failed/;
2342 }
2343 } ## end if (defined &main::dumpvar)
2344 else {
2345
2346 # Couldn't load dumpvar.
2347 print $OUT "dumpvar.pl not available.\n";
2348 }
69893cff 2349
69893cff 2350 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2351 select($savout);
2352 next CMD;
826b9a2e 2353 }
69893cff
RGS
2354
2355=head4 C<x> - evaluate and print an expression
2356
2357Hands the expression off to C<DB::eval>, setting it up to print the value
2358via C<dumpvar.pl> instead of just printing it directly.
2359
2360=cut
2361
826b9a2e 2362 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2363 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2364
2365 # handle special "x 3 blah" syntax XXX propagate
2366 # doc back to special variables.
826b9a2e 2367 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2368 $onetimedumpDepth = $1;
2369 }
826b9a2e 2370 }
69893cff
RGS
2371
2372=head4 C<m> - print methods
2373
2374Just uses C<DB::methods> to determine what methods are available.
2375
2376=cut
2377
826b9a2e 2378 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2379 methods($1);
2380 next CMD;
826b9a2e 2381 }
69893cff
RGS
2382
2383 # m expr - set up DB::eval to do the work
826b9a2e 2384 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2385 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2386 }
69893cff
RGS
2387
2388=head4 C<f> - switch files
2389
2390=cut
2391
826b9a2e 2392 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2393 $file =~ s/\s+$//;
69893cff
RGS
2394
2395 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2396 if ( !$file ) {
2397 print $OUT
2398 "The old f command is now the r command.\n"; # hint
2399 print $OUT "The new f command switches filenames.\n";
2400 next CMD;
2401 } ## end if (!$file)
69893cff
RGS
2402
2403 # if not in magic file list, try a close match.
e22ea7cc
RF
2404 if ( !defined $main::{ '_<' . $file } ) {
2405 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2406 {
2407 $try = substr( $try, 2 );
1f874cb6 2408 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2409 $file = $try;
2410 }
2411 } ## end if (($try) = grep(m#^_<.*$file#...
2412 } ## end if (!defined $main::{ ...
69893cff
RGS
2413
2414 # If not successfully switched now, we failed.
e22ea7cc 2415 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2416 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2417 next CMD;
2418 }
69893cff 2419
e22ea7cc
RF
2420 # We switched, so switch the debugger internals around.
2421 elsif ( $file ne $filename ) {
2422 *dbline = $main::{ '_<' . $file };
2423 $max = $#dbline;
2424 $filename = $file;
2425 $start = 1;
2426 $cmd = "l";
2427 } ## end elsif ($file ne $filename)
2428
2429 # We didn't switch; say we didn't.
2430 else {
2431 print $OUT "Already in $file.\n";
2432 next CMD;
2433 }
826b9a2e 2434 }
69893cff
RGS
2435
2436=head4 C<.> - return to last-executed line.
2437
2438We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2439and then we look up the line in the magical C<%dbline> hash.
2440
2441=cut
2442
2443 # . command.
826b9a2e 2444 if ($cmd eq '.') {
e22ea7cc 2445 $incr = -1; # stay at current line
69893cff
RGS
2446
2447 # Reset everything to the old location.
e22ea7cc
RF
2448 $start = $line;
2449 $filename = $filename_ini;
2450 *dbline = $main::{ '_<' . $filename };
2451 $max = $#dbline;
69893cff
RGS
2452
2453 # Now where are we?
e22ea7cc
RF
2454 print_lineinfo($position);
2455 next CMD;
826b9a2e 2456 }
69893cff
RGS
2457
2458=head4 C<-> - back one window
2459
2460We change C<$start> to be one window back; if we go back past the first line,
2461we set it to be the first line. We ser C<$incr> to put us back at the
2462currently-executing line, and then put a C<l $start +> (list one window from
2463C<$start>) in C<$cmd> to be executed later.
2464
2465=cut
2466
2467 # - - back a window.
826b9a2e 2468 if ($cmd eq '-') {
e22ea7cc 2469
69893cff 2470 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2471 $start -= $incr + $window + 1;
2472 $start = 1 if $start <= 0;
2473 $incr = $window - 1;
69893cff
RGS
2474
2475 # Generate and execute a "l +" command (handled below).
e22ea7cc 2476 $cmd = 'l ' . ($start) . '+';
826b9a2e 2477 }
69893cff
RGS
2478
2479=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>, {, {{>
2480
2481In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2482problems, most notably that the default case of several commands destroying
2483the user's work in setting watchpoints, actions, etc. We wanted, however, to
2484retain the old commands for those who were used to using them or who preferred
2485them. At this point, we check for the new commands and call C<cmd_wrapper> to
2486deal with them instead of processing them in-line.
2487
2488=cut
2489
2490 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2491 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2492 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2493 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2494 next CMD;
826b9a2e 2495 }
69893cff
RGS
2496
2497=head4 C<y> - List lexicals in higher scope
2498
826b9a2e 2499Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2500above the current one and then displays then using C<dumpvar.pl>.
2501
2502=cut
2503
826b9a2e
SF
2504 if (my ($match_level, $match_vars)
2505 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2506
2507 # See if we've got the necessary support.
2508 eval { require PadWalker; PadWalker->VERSION(0.08) }
2509 or &warn(
2510 $@ =~ /locate/
2511 ? "PadWalker module not found - please install\n"
2512 : $@
2513 )
2514 and next CMD;
2515
2516 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2517 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2518 defined &main::dumpvar
2519 or print $OUT "dumpvar.pl not available.\n"
2520 and next CMD;
2521
2522 # Got all the modules we need. Find them and print them.
826b9a2e 2523 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2524
2525 # Find the pad.
826b9a2e 2526 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2527
2528 # Oops. Can't find it.
2529 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2530
2531 # Show the desired vars with dumplex().
2532 my $savout = select($OUT);
2533
2534 # Have dumplex dump the lexicals.
e22ea7cc 2535 dumpvar::dumplex( $_, $h->{$_},
69893cff 2536 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2537 @vars )
2538 for sort keys %$h;
69893cff
RGS
2539 select($savout);
2540 next CMD;
826b9a2e 2541 }
69893cff
RGS
2542
2543=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2544
2545All of the commands below this point don't work after the program being
2546debugged has ended. All of them check to see if the program has ended; this
2547allows the commands to be relocated without worrying about a 'line of
2548demarcation' above which commands can be entered anytime, and below which
2549they can't.
2550
2551=head4 C<n> - single step, but don't trace down into subs
2552
2553Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2554when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2555so a null command knows what to re-execute.
69893cff
RGS
2556
2557=cut
2558
e22ea7cc 2559 # n - next
826b9a2e 2560 if ($cmd eq 'n') {
69893cff 2561 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2562
69893cff
RGS
2563 # Single step, but don't enter subs.
2564 $single = 2;
e22ea7cc 2565
69893cff 2566 # Save for empty command (repeat last).
e22ea7cc
RF
2567 $laststep = $cmd;
2568 last CMD;
826b9a2e 2569 }
69893cff
RGS
2570
2571=head4 C<s> - single-step, entering subs
2572
826b9a2e 2573Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2574subs. Also saves C<s> as C<$lastcmd>.
2575
2576=cut
2577
2578 # s - single step.
826b9a2e 2579 if ($cmd eq 's') {
e22ea7cc 2580
69893cff
RGS
2581 # Get out and restart the command loop if program
2582 # has finished.
e22ea7cc
RF
2583 end_report(), next CMD if $finished and $level <= 1;
2584
69893cff 2585 # Single step should enter subs.
e22ea7cc
RF
2586 $single = 1;
2587
69893cff 2588 # Save for empty command (repeat last).
e22ea7cc
RF
2589 $laststep = $cmd;
2590 last CMD;
826b9a2e 2591 }
69893cff
RGS
2592
2593=head4 C<c> - run continuously, setting an optional breakpoint
2594
2595Most of the code for this command is taken up with locating the optional
2596breakpoint, which is either a subroutine name or a line number. We set
2597the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2598in this and all call levels above this one.
2599
2600=cut
2601
2602 # c - start continuous execution.
ef18ae63 2603 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2604
69893cff
RGS
2605 # Hey, show's over. The debugged program finished
2606 # executing already.
2607 end_report(), next CMD if $finished and $level <= 1;
2608
2609 # Capture the place to put a one-time break.
ef18ae63 2610 $subname = $i;
69893cff 2611
e22ea7cc
RF
2612 # Probably not needed, since we finish an interactive
2613 # sub-session anyway...
2614 # local $filename = $filename;
2615 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2616 #
2617 # The above question wonders if localizing the alias
2618 # to the magic array works or not. Since it's commented
2619 # out, we'll just leave that to speculation for now.
2620
2621 # If the "subname" isn't all digits, we'll assume it
2622 # is a subroutine name, and try to find it.
e22ea7cc
RF
2623 if ( $subname =~ /\D/ ) { # subroutine name
2624 # Qualify it to the current package unless it's
2625 # already qualified.
69893cff
RGS
2626 $subname = $package . "::" . $subname
2627 unless $subname =~ /::/;
e22ea7cc 2628
69893cff
RGS
2629 # find_sub will return "file:line_number" corresponding
2630 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2631 # break up the return value, and assign it in one
69893cff 2632 # operation.
e22ea7cc 2633 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2634
2635 # Force the line number to be numeric.
e22ea7cc 2636 $i += 0;
69893cff
RGS
2637
2638 # If we got a line number, we found the sub.
e22ea7cc
RF
2639 if ($i) {
2640
69893cff
RGS
2641 # Switch all the debugger's internals around so
2642 # we're actually working with that file.
e22ea7cc
RF
2643 $filename = $file;
2644 *dbline = $main::{ '_<' . $filename };
2645
69893cff 2646 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2647 $had_breakpoints{$filename} |= 1;
2648
69893cff
RGS
2649 # Scan forward to the first executable line
2650 # after the 'sub whatever' line.
e22ea7cc
RF
2651 $max = $#dbline;
2652 ++$i while $dbline[$i] == 0 && $i < $max;
2653 } ## end if ($i)
69893cff
RGS
2654
2655 # We didn't find a sub by that name.
e22ea7cc
RF
2656 else {
2657 print $OUT "Subroutine $subname not found.\n";
2658 next CMD;
2659 }
2660 } ## end if ($subname =~ /\D/)
69893cff
RGS
2661
2662 # At this point, either the subname was all digits (an
2663 # absolute line-break request) or we've scanned through
2664 # the code following the definition of the sub, looking
2665 # for an executable, which we may or may not have found.
2666 #
2667 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2668 # got a request to break at some line somewhere. On
2669 # one hand, if there wasn't any real subroutine name
2670 # involved, this will be a request to break in the current
2671 # file at the specified line, so we have to check to make
69893cff
RGS
2672 # sure that the line specified really is breakable.
2673 #
2674 # On the other hand, if there was a subname supplied, the
3c4b39be 2675 # preceding block has moved us to the proper file and
69893cff
RGS
2676 # location within that file, and then scanned forward
2677 # looking for the next executable line. We have to make
2678 # sure that one was found.
2679 #
2680 # On the gripping hand, we can't do anything unless the
2681 # current value of $i points to a valid breakable line.
2682 # Check that.
e22ea7cc
RF
2683 if ($i) {
2684
69893cff 2685 # Breakable?
e22ea7cc
RF
2686 if ( $dbline[$i] == 0 ) {
2687 print $OUT "Line $i not breakable.\n";
2688 next CMD;
2689 }
2690
69893cff 2691 # Yes. Set up the one-time-break sigil.
e22ea7cc 2692 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2693 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2694 } ## end if ($i)
69893cff
RGS
2695
2696 # Turn off stack tracing from here up.
2c247e84
SF
2697 for my $i (0 .. $stack_depth) {
2698 $stack[ $i ] &= ~1;
e22ea7cc
RF
2699 }
2700 last CMD;
ef18ae63 2701 }
69893cff
RGS
2702
2703=head4 C<r> - return from a subroutine
2704
2705For C<r> to work properly, the debugger has to stop execution again
2706immediately after the return is executed. This is done by forcing
2707single-stepping to be on in the call level above the current one. If
2708we are printing return values when a C<r> is executed, set C<$doret>
2709appropriately, and force us out of the command loop.
2710
2711=cut
2712
2713 # r - return from the current subroutine.
ef18ae63 2714 if ($cmd eq 'r') {
e22ea7cc 2715
98dc9551 2716 # Can't do anything if the program's over.
e22ea7cc
RF
2717 end_report(), next CMD if $finished and $level <= 1;
2718
69893cff 2719 # Turn on stack trace.
e22ea7cc
RF
2720 $stack[$stack_depth] |= 1;
2721
69893cff 2722 # Print return value unless the stack is empty.
e22ea7cc
RF
2723 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2724 last CMD;
ef18ae63 2725 }
69893cff 2726
69893cff
RGS
2727=head4 C<T> - stack trace
2728
2729Just calls C<DB::print_trace>.
2730
2731=cut
2732
ef18ae63 2733 if ($cmd eq 'T') {
e22ea7cc
RF
2734 print_trace( $OUT, 1 ); # skip DB
2735 next CMD;
ef18ae63 2736 }
69893cff
RGS
2737
2738=head4 C<w> - List window around current line.
2739
2740Just calls C<DB::cmd_w>.
2741
2742=cut
2743
ef18ae63
SF
2744 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2745 &cmd_w( 'w', $arg );
2746 next CMD;
2747 }
69893cff
RGS
2748
2749=head4 C<W> - watch-expression processing.
2750
b570d64b 2751Just calls C<DB::cmd_W>.
69893cff
RGS
2752
2753=cut
2754
ef18ae63
SF
2755 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2756 &cmd_W( 'W', $arg );
2757 next CMD;
2758 }
69893cff
RGS
2759
2760=head4 C</> - search forward for a string in the source
2761
ef18ae63 2762We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2763bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2764If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2765mess us up.
2766
2767=cut
2768
ef18ae63
SF
2769 # The pattern as a string.
2770 use vars qw($inpat);
69893cff 2771
ef18ae63 2772 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2773
2774 # Remove the final slash.
e22ea7cc 2775 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2776
2777 # If the pattern isn't null ...
e22ea7cc 2778 if ( $inpat ne "" ) {
69893cff
RGS
2779
2780 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2781 local $SIG{__DIE__};
2782 local $SIG{__WARN__};
69893cff
RGS
2783
2784 # Create the pattern.
e22ea7cc
RF
2785 eval '$inpat =~ m' . "\a$inpat\a";
2786 if ( $@ ne "" ) {
2787
69893cff 2788 # Oops. Bad pattern. No biscuit.
e22ea7cc 2789 # Print the eval error and go back for more
69893cff 2790 # commands.
e22ea7cc
RF
2791 print $OUT "$@";
2792 next CMD;
2793 }
2794 $pat = $inpat;
2795 } ## end if ($inpat ne "")
69893cff
RGS
2796
2797 # Set up to stop on wrap-around.
e22ea7cc 2798 $end = $start;
69893cff
RGS
2799
2800 # Don't move off the current line.
e22ea7cc 2801 $incr = -1;
69893cff
RGS
2802
2803 # Done in eval so nothing breaks if the pattern
2804 # does something weird.
e22ea7cc
RF
2805 eval '
2806 for (;;) {
69893cff 2807 # Move ahead one line.
e22ea7cc 2808 ++$start;
69893cff
RGS
2809
2810 # Wrap if we pass the last line.
e22ea7cc 2811 $start = 1 if ($start > $max);
69893cff
RGS
2812
2813 # Stop if we have gotten back to this line again,
e22ea7cc 2814 last if ($start == $end);
69893cff
RGS
2815
2816 # A hit! (Note, though, that we are doing
2817 # case-insensitive matching. Maybe a qr//
2818 # expression would be better, so the user could
2819 # do case-sensitive matching if desired.
e22ea7cc
RF
2820 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2821 if ($slave_editor) {
69893cff 2822 # Handle proper escaping in the slave.
e22ea7cc 2823 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2824 }
e22ea7cc 2825 else {
69893cff 2826 # Just print the line normally.
e22ea7cc
RF
2827 print $OUT "$start:\t",$dbline[$start],"\n";
2828 }
69893cff 2829 # And quit since we found something.
e22ea7cc
RF
2830 last;
2831 }
2832 } ';
2833
69893cff 2834 # If we wrapped, there never was a match.
e22ea7cc
RF
2835 print $OUT "/$pat/: not found\n" if ( $start == $end );
2836 next CMD;
ef18ae63 2837 }
69893cff
RGS
2838
2839=head4 C<?> - search backward for a string in the source
2840
2841Same as for C</>, except the loop runs backwards.
2842
2843=cut
2844
2845 # ? - backward pattern search.
ef18ae63 2846 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2847
2848 # Get the pattern, remove trailing question mark.
e22ea7cc 2849 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2850
2851 # If we've got one ...
e22ea7cc 2852 if ( $inpat ne "" ) {
69893cff
RGS
2853
2854 # Turn off die & warn handlers.
e22ea7cc
RF
2855 local $SIG{__DIE__};
2856 local $SIG{__WARN__};
2857 eval '$inpat =~ m' . "\a$inpat\a";
2858
2859 if ( $@ ne "" ) {
2860
69893cff 2861 # Ouch. Not good. Print the error.
e22ea7cc
RF
2862 print $OUT $@;
2863 next CMD;
2864 }
2865 $pat = $inpat;
69893cff 2866 } ## end if ($inpat ne "")
e22ea7cc 2867
69893cff 2868 # Where we are now is where to stop after wraparound.
e22ea7cc 2869 $end = $start;
69893cff
RGS
2870
2871 # Don't move away from this line.
e22ea7cc 2872 $incr = -1;
69893cff
RGS
2873
2874 # Search inside the eval to prevent pattern badness
2875 # from killing us.
e22ea7cc
RF
2876 eval '
2877 for (;;) {
69893cff 2878 # Back up a line.
e22ea7cc 2879 --$start;
69893cff
RGS
2880
2881 # Wrap if we pass the first line.
e22ea7cc
RF
2882
2883 $start = $max if ($start <= 0);
69893cff
RGS
2884
2885 # Quit if we get back where we started,
e22ea7cc 2886 last if ($start == $end);
69893cff
RGS
2887
2888 # Match?
e22ea7cc
RF
2889 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2890 if ($slave_editor) {
69893cff 2891 # Yep, follow slave editor requirements.
e22ea7cc 2892 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2893 }
e22ea7cc 2894 else {
69893cff 2895 # Yep, just print normally.
e22ea7cc
RF
2896 print $OUT "$start:\t",$dbline[$start],"\n";
2897 }
69893cff
RGS
2898
2899 # Found, so done.
e22ea7cc
RF
2900 last;
2901 }
2902 } ';
2903
2904 # Say we failed if the loop never found anything,
2905 print $OUT "?$pat?: not found\n" if ( $start == $end );
2906 next CMD;
ef18ae63 2907 }
69893cff
RGS
2908
2909=head4 C<$rc> - Recall command
2910
2911Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2912that the terminal supports history). It find the the command required, puts it
2913into C<$cmd>, and redoes the loop to execute it.
2914
2915=cut
2916
e22ea7cc 2917 # $rc - recall command.
ef18ae63 2918 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2919
2920 # No arguments, take one thing off history.
e22ea7cc 2921 pop(@hist) if length($cmd) > 1;
69893cff 2922
e22ea7cc 2923 # Relative (- found)?
69893cff 2924 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2925 # N - go to that particular command slot or the last
69893cff 2926 # thing if nothing following.
ef18ae63 2927 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2928
2929 # Pick out the command desired.
e22ea7cc 2930 $cmd = $hist[$i];
69893cff
RGS
2931
2932 # Print the command to be executed and restart the loop
2933 # with that command in the buffer.
e22ea7cc
RF
2934 print $OUT $cmd, "\n";
2935 redo CMD;
ef18ae63 2936 }
69893cff
RGS
2937
2938=head4 C<$sh$sh> - C<system()> command
2939
2940Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2941C<STDOUT> from getting messed up.
2942
2943=cut
2944
2945 # $sh$sh - run a shell command (if it's all ASCII).
2946 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2947 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2948
69893cff 2949 # System it.
ef18ae63 2950 &system($arg);
e22ea7cc 2951 next CMD;
ef18ae63 2952 }
69893cff
RGS
2953
2954=head4 C<$rc I<pattern> $rc> - Search command history
2955
2956Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2957If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2958
2959=cut
2960
e22ea7cc 2961 # $rc pattern $rc - find a command in the history.
ef18ae63 2962 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2963
69893cff 2964 # Create the pattern to use.
ef18ae63 2965 $pat = "^$arg";
69893cff
RGS
2966
2967 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2968 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2969
2970 # Look backward through the history.
72d7d80d 2971 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2972 # Stop if we find it.
e22ea7cc
RF
2973 last if $hist[$i] =~ /$pat/;
2974 }
2975
2976 if ( !$i ) {
69893cff 2977
69893cff 2978 # Never found it.
e22ea7cc
RF
2979 print $OUT "No such command!\n\n";
2980 next CMD;
2981 }
69893cff
RGS
2982
2983 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2984 $cmd = $hist[$i];
2985 print $OUT $cmd, "\n";
2986 redo CMD;
ef18ae63 2987 }
69893cff 2988
ef18ae63 2989=head4 C<$sh> - Invoke a shell
69893cff
RGS
2990
2991Uses C<DB::system> to invoke a shell.
2992
2993=cut
2994
2995 # $sh - start a shell.
ef18ae63 2996 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2997
69893cff
RGS
2998 # Run the user's shell. If none defined, run Bourne.
2999 # We resume execution when the shell terminates.
e22ea7cc
RF
3000 &system( $ENV{SHELL} || "/bin/sh" );
3001 next CMD;
ef18ae63 3002 }
69893cff
RGS
3003
3004=head4 C<$sh I<command>> - Force execution of a command in a shell
3005
3006Like the above, but the command is passed to the shell. Again, we use
3007C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3008
3009=cut
3010
3011 # $sh command - start a shell and run a command in it.
ef18ae63 3012 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
3013
3014 # XXX: using csh or tcsh destroys sigint retvals!
3015 #&system($1); # use this instead
69893cff
RGS
3016
3017 # use the user's shell, or Bourne if none defined.
ef18ae63 3018 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 3019 next CMD;
ef18ae63 3020 }
69893cff
RGS
3021
3022=head4 C<H> - display commands in history
3023
3024Prints the contents of C<@hist> (if any).
3025
3026=cut
3027
ef18ae63 3028 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
3029 @hist = @truehist = ();
3030 print $OUT "History cleansed\n";
3031 next CMD;
ef18ae63 3032 }
e22ea7cc 3033
ef18ae63
SF
3034 if (my ($num)
3035 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
3036
3037 # Anything other than negative numbers is ignored by
69893cff 3038 # the (incorrect) pattern, so this test does nothing.
ef18ae63 3039 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
3040
3041 # Set to the minimum if less than zero.
e22ea7cc 3042 $hist = 0 if $hist < 0;
69893cff 3043
e22ea7cc 3044 # Start at the end of the array.
69893cff
RGS
3045 # Stay in while we're still above the ending value.
3046 # Tick back by one each time around the loop.
72d7d80d 3047 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3048
3049 # Print the command unless it has no arguments.
e22ea7cc
RF
3050 print $OUT "$i: ", $hist[$i], "\n"
3051 unless $hist[$i] =~ /^.?$/;
3052 }
3053 next CMD;
ef18ae63 3054 }
69893cff
RGS
3055
3056=head4 C<man, doc, perldoc> - look up documentation
3057
3058Just calls C<runman()> to print the appropriate document.
3059
3060=cut
3061
e22ea7cc 3062 # man, perldoc, doc - show manual pages.
ef18ae63
SF
3063 if (my ($man_page)
3064 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3065 runman($man_page);
e22ea7cc 3066 next CMD;
ef18ae63 3067 }
69893cff
RGS
3068
3069=head4 C<p> - print
3070
3071Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3072the bottom of the loop.
3073
3074=cut
3075
ef18ae63 3076 my $print_cmd = 'print {$DB::OUT} ';
69893cff 3077 # p - print (no args): print $_.
ef18ae63
SF
3078 if ($cmd eq 'p') {
3079 $cmd = $print_cmd . '$_';
3080 }
69893cff
RGS
3081
3082 # p - print the given expression.
ef18ae63 3083 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
3084
3085=head4 C<=> - define command alias
3086
3087Manipulates C<%alias> to add or list command aliases.
3088
3089=cut
3090
e22ea7cc 3091 # = - set up a command alias.
ef18ae63 3092 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
3093 my @keys;
3094 if ( length $cmd == 0 ) {
3095
69893cff 3096 # No args, get current aliases.
e22ea7cc
RF
3097 @keys = sort keys %alias;
3098 }
3099 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3100
69893cff
RGS
3101 # Creating a new alias. $k is alias name, $v is
3102 # alias value.
3103
e22ea7cc
RF
3104 # can't use $_ or kill //g state
3105 for my $x ( $k, $v ) {
3106
3107 # Escape "alarm" characters.
3108 $x =~ s/\a/\\a/g;
3109 }
69893cff
RGS
3110
3111 # Substitute key for value, using alarm chars
e22ea7cc 3112 # as separators (which is why we escaped them in
69893cff 3113 # the command).
e22ea7cc 3114 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3115
3116 # Turn off standard warn and die behavior.
e22ea7cc
RF
3117 local $SIG{__DIE__};
3118 local $SIG{__WARN__};
69893cff
RGS
3119
3120 # Is it valid Perl?
e22ea7cc
RF
3121 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3122
69893cff 3123 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3124 print $OUT "Can't alias $k to $v: $@\n";
3125 delete $alias{$k};
3126 next CMD;
3127 }
3128
69893cff 3129 # We'll only list the new one.
e22ea7cc 3130 @keys = ($k);
69893cff
RGS
3131 } ## end elsif (my ($k, $v) = ($cmd...
3132
3133 # The argument is the alias to list.
e22ea7cc
RF
3134 else {
3135 @keys = ($cmd);
3136 }
69893cff
RGS
3137
3138 # List aliases.
e22ea7cc
RF
3139 for my $k (@keys) {
3140
98dc9551 3141 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
3142 # We use control-G as the delimiter because it's not
3143 # likely to appear in the alias.
e22ea7cc
RF
3144 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3145
69893cff 3146 # Print the alias.
e22ea7cc
RF
3147 print $OUT "$k\t= $1\n";
3148 }
3149 elsif ( defined $alias{$k} ) {
3150
69893cff 3151 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3152 print $OUT "$k\t$alias{$k}\n";
3153 }
3154 else {
3155
69893cff 3156 # No such, dude.
e22ea7cc
RF
3157 print "No alias for $k\n";
3158 }
69893cff 3159 } ## end for my $k (@keys)
e22ea7cc 3160 next CMD;
ef18ae63 3161 }
69893cff
RGS
3162
3163=head4 C<source> - read commands from a file.
3164
3165Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3166pick it up.
3167
3168=cut
3169
e22ea7cc 3170 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3171 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3172 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3173
69893cff 3174 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3175 push @cmdfhs, $fh;
3176 }
3177 else {
3178
3179 # Couldn't open it.
ef18ae63 3180 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3181 }
3182 next CMD;
ef18ae63 3183 }
69893cff 3184
ef18ae63
SF
3185 if (my ($which_cmd, $position)
3186 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3187
3188 my ($fn, $line_num);
3189 if ($position =~ m{\A\d+\z})
3190 {
3191 $fn = $filename;
3192 $line_num = $position;
3193 }
ef18ae63
SF
3194 elsif (my ($new_fn, $new_line_num)
3195 = $position =~ m{\A(.*):(\d+)\z}) {
3196 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3197 }
3198 else
3199 {
3200 &warn("Wrong spec for enable/disable argument.\n");
3201 }
3202
3203 if (defined($fn)) {
3204 if (_has_breakpoint_data_ref($fn, $line_num)) {
3205 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3206 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3207 );
3208 }
3209 else {
3210 &warn("No breakpoint set at ${fn}:${line_num}\n");
3211 }
3212 }
3213
3214 next CMD;
ef18ae63 3215 }
e09195af 3216
69893cff
RGS
3217=head4 C<save> - send current history to a file
3218
3219Takes the complete history, (not the shrunken version you see with C<H>),
3220and saves it to the given filename, so it can be replayed using C<source>.
3221
3222Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3223
3224=cut
3225
3226 # save source - write commands to a file for later use
ef18ae63
SF
3227 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3228 my $filename = $new_fn || '.perl5dbrc'; # default?
3229 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3230
3231 # chomp to remove extraneous newlines from source'd files
3232 chomp( my @truelist =
3233 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3234 @truehist );
3235 print $fh join( "\n", @truelist );
69893cff 3236 print "commands saved in $file\n";
e22ea7cc
RF
3237 }
3238 else {
ef18ae63 3239 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3240 }
3241 next CMD;
ef18ae63 3242 }
69893cff 3243
7fddc82f
RF
3244=head4 C<R> - restart
3245
ef18ae63 3246Restart the debugger session.
7fddc82f
RF
3247
3248=head4 C<rerun> - rerun the current session
3249
3250Return to any given position in the B<true>-history list
3251
3252=cut
3253
3254 # R - restart execution.
3255 # rerun - controlled restart execution.
ff41e38d
SF
3256 if (my ($cmd_cmd, $cmd_params) =
3257 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3258 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3259
ca28b541
AP
3260 # Close all non-system fds for a clean restart. A more
3261 # correct method would be to close all fds that were not
3262 # open when the process started, but this seems to be
3263 # hard. See "debugger 'R'estart and open database
3264 # connections" on p5p.
3265
47d3bbda 3266 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3267 if (eval { require POSIX }) {
5332cc68 3268 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3269 }
3270
3271 if (defined $max_fd) {
3272 foreach ($^F+1 .. $max_fd-1) {
3273 next unless open FD_TO_CLOSE, "<&=$_";
3274 close(FD_TO_CLOSE);
3275 }
3276 }
3277
7fddc82f
RF
3278 # And run Perl again. We use exec() to keep the
3279 # PID stable (and that way $ini_pids is still valid).
3280 exec(@args) || print $OUT "exec failed: $!\n";
3281
3282 last CMD;
ff41e38d 3283 }
7fddc82f 3284
69893cff
RGS
3285=head4 C<|, ||> - pipe output through the pager.
3286
be9a9b1d 3287For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3288(the program's standard output). For C<||>, we only save C<OUT>. We open a
3289pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3290is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3291set C<$signal>, sending us back into the debugger.
3292
3293We then trim off the pipe symbols and C<redo> the command loop at the
3294C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3295reading another.
3296
3297=cut
3298
3299 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3300 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3301 if ( $pager =~ /^\|/ ) {
3302
69893cff 3303 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3304 open( SAVEOUT, ">&STDOUT" )
3305 || &warn("Can't save STDOUT");
3306 open( STDOUT, ">&OUT" )
3307 || &warn("Can't redirect STDOUT");
69893cff 3308 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3309 else {
3310
69893cff 3311 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3312 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3313 }
69893cff
RGS
3314
3315 # Fix up environment to record we have less if so.
e22ea7cc
RF
3316 fix_less();
3317
3318 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3319
69893cff 3320 # Couldn't open pipe to pager.
1f874cb6 3321 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3322 if ( $pager =~ /^\|/ ) {
3323
69893cff 3324 # Redirect I/O back again.
e22ea7cc
RF
3325 open( OUT, ">&STDOUT" ) # XXX: lost message
3326 || &warn("Can't restore DB::OUT");
3327 open( STDOUT, ">&SAVEOUT" )
3328 || &warn("Can't restore STDOUT");
3329 close(SAVEOUT);
69893cff 3330 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3331 else {
3332
69893cff 3333 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3334 open( OUT, ">&STDOUT" ) # XXX: lost message
3335 || &warn("Can't restore DB::OUT");
3336 }
3337 next CMD;
69893cff
RGS
3338 } ## end unless ($piped = open(OUT,...
3339
3340 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3341 $SIG{PIPE} = \&DB::catch
3342 if $pager =~ /^\|/
3343 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3344
70c9432b
SF
3345 OUT->autoflush(1);
3346 # Save current filehandle, and put it back.
e22ea7cc 3347 $selected = select(OUT);
69893cff 3348 # Don't put it back if pager was a pipe.
e22ea7cc 3349 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3350
3351 # Trim off the pipe symbols and run the command now.
ff41e38d 3352 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3353 redo PIPE;
ff41e38d 3354 }
69893cff
RGS
3355
3356=head3 END OF COMMAND PARSING
3357
ff41e38d
SF
3358Anything left in C<$cmd> at this point is a Perl expression that we want to
3359evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3360any variables we might want to address in the C<DB> package.
3361
3362=cut
3363
3364 # t - turn trace on.
ff41e38d
SF
3365 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3366 my $trace_arg = $1;
3367 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3368 }
69893cff
RGS
3369
3370 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3371 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3372 $laststep = 's';
3373 }
69893cff
RGS
3374
3375 # n - single-step, but not into subs. Remember last command
e22ea7cc 3376 # was 'n'.
ff41e38d
SF
3377 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3378 $laststep = 'n';
3379 }
69893cff 3380
e22ea7cc 3381 } # PIPE:
69893cff 3382
e22ea7cc 3383 # Make sure the flag that says "the debugger's running" is
69893cff 3384 # still on, to make sure we get control again.
e22ea7cc 3385 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3386
3387 # Run *our* eval that executes in the caller's context.
e22ea7cc 3388 &eval;
69893cff
RGS
3389
3390 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3391 if ($onetimeDump) {
3392 $onetimeDump = undef;
69893cff 3393 $onetimedumpDepth = undef;
e22ea7cc
RF
3394 }
3395 elsif ( $term_pid == $$ ) {
c7e68384
IZ
3396 eval { # May run under miniperl, when not available...
3397 STDOUT->flush();
3398 STDERR->flush();
3399 };
e22ea7cc 3400
69893cff 3401 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3402 print $OUT "\n";
3403 }
3404 } ## end while (($term || &setterm...
69893cff
RGS
3405
3406=head3 POST-COMMAND PROCESSING
3407
3408After each command, we check to see if the command output was piped anywhere.
3409If so, we go through the necessary code to unhook the pipe and go back to
3410our standard filehandles for input and output.
3411
3412=cut
3413
e22ea7cc 3414 continue { # CMD:
69893cff
RGS
3415
3416 # At the end of every command:
e22ea7cc
RF
3417 if ($piped) {
3418
69893cff 3419 # Unhook the pipe mechanism now.
e22ea7cc
RF
3420 if ( $pager =~ /^\|/ ) {
3421
69893cff 3422 # No error from the child.
e22ea7cc 3423 $? = 0;
69893cff 3424
e22ea7cc
RF
3425 # we cannot warn here: the handle is missing --tchrist
3426 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3427
e22ea7cc 3428 # most of the $? crud was coping with broken cshisms
69893cff 3429 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3430 if ($?) {
1f874cb6 3431 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3432 if ( $? == -1 ) {
3433 print SAVEOUT "shell returned -1\n";
3434 }
3435 elsif ( $? >> 8 ) {
3436 print SAVEOUT ( $? & 127 )
3437 ? " (SIG#" . ( $? & 127 ) . ")"
3438 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3439 }
3440 else {
3441 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3442 }
69893cff
RGS
3443 } ## end if ($?)
3444
e22ea7cc 3445 # Reopen filehandle for our output (if we can) and
69893cff 3446 # restore STDOUT (if we can).
e22ea7cc
RF
3447 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3448 open( STDOUT, ">&SAVEOUT" )
3449 || &warn("Can't restore STDOUT");
69893cff
RGS
3450
3451 # Turn off pipe exception handler if necessary.
e22ea7cc 3452 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3453
e22ea7cc
RF
3454 # Will stop ignoring SIGPIPE if done like nohup(1)
3455 # does SIGINT but Perl doesn't give us a choice.
69893cff 3456 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3457 else {
3458
69893cff 3459 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3460 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3461 }
69893cff
RGS
3462
3463 # Close filehandle pager was using, restore the normal one
3464 # if necessary,
3465 close(SAVEOUT);
e22ea7cc 3466 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3467
3468 # No pipes now.
e22ea7cc 3469 $piped = "";
69893cff 3470 } ## end if ($piped)
e22ea7cc 3471 } # CMD:
69893cff
RGS
3472
3473=head3 COMMAND LOOP TERMINATION
3474
3475When commands have finished executing, we come here. If the user closed the
3476input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3477evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3478C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3479The interpreter will then execute the next line and then return control to us
3480again.
3481
3482=cut
3483
3484 # No more commands? Quit.
1f874cb6 3485 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3486
3487 # Evaluate post-prompt commands.
e22ea7cc
RF
3488 foreach $evalarg (@$post) {
3489 &eval;
3490 }
3491 } # if ($single || $signal)
69893cff
RGS
3492
3493 # Put the user's globals back where you found them.
e22ea7cc 3494 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3495 ();
3496} ## end sub DB
3497
3498# The following code may be executed now:
3499# BEGIN {warn 4}
3500
3501=head2 sub
3502
b570d64b 3503C<sub> is called whenever a subroutine call happens in the program being
69893cff
RGS
3504debugged. The variable C<$DB::sub> contains the name of the subroutine
3505being called.
3506
3507The core function of this subroutine is to actually call the sub in the proper
3508context, capturing its output. This of course causes C<DB::DB> to get called
3509again, repeating until the subroutine ends and returns control to C<DB::sub>
3510again. Once control returns, C<DB::sub> figures out whether or not to dump the
3511return value, and returns its captured copy of the return value as its own
3512return value. The value then feeds back into the program being debugged as if
3513C<DB::sub> hadn't been there at all.
3514
3515C<sub> does all the work of printing the subroutine entry and exit messages
3516enabled by setting C<$frame>. It notes what sub the autoloader got called for,
b570d64b 3517and also prints the return value if needed (for the C<r> command and if
69893cff
RGS
3518the 16 bit is set in C<$frame>).
3519
3520It also tracks the subroutine call depth by saving the current setting of
3521C<$single> in the C<@stack> package global; if this exceeds the value in
3522C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3523setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3524of stop/don't stop on entry to subs set as it currently is set.
3525
3526=head3 C<caller()> support
3527
3528If C<caller()> is called from the package C<DB>, it provides some
3529additional data, in the following order:
3530
3531=over 4
3532
3533=item * C<$package>
3534
3535The package name the sub was in
3536
3537=item * C<$filename>
3538
3539The filename it was defined in
3540
3541=item * C<$line>
3542
3543The line number it was defined on
3544