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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
ef18ae63 189The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
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190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
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193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
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200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
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204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
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214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
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218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
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227ReadLine applications.
228
b570d64b 229=item * NonStop
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230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
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234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
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239
240host:port to connect to on remote host for remote debugging.
241
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242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
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252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
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262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
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269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
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285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
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308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
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314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
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318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
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331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
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333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
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354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
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368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
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375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
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377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
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383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
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406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
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446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
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454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 476=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
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477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
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486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
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490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
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494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
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504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
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511package DB;
512
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513use strict;
514
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
2218c045
SF
871# These variables control the execution of 'dumpvar.pl'.
872{
873 package dumpvar;
874 use vars qw(
875 $hashDepth
876 $arrayDepth
877 $dumpDBFiles
878 $dumpPackages
879 $quoteHighBit
880 $printUndef
881 $globPrint
882 $usageOnly
883 );
884}
69893cff 885
2218c045
SF
886# used to control die() reporting in diesignal()
887{
888 package Carp;
889 use vars qw($CarpLevel);
890}
d338d6fe 891
422c59bf 892# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 893foreach my $k (keys (%INC)) {
fb4d8a6c 894 share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
895};
896
54d04a52 897# Command-line + PERLLIB:
69893cff 898# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
899@ini_INC = @INC;
900
69893cff
RGS
901# This was an attempt to clear out the previous values of various
902# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
903# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
904
69893cff
RGS
905# We set these variables to safe values. We don't want to blindly turn
906# off warnings, because other packages may still want them.
e22ea7cc
RF
907$trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
69893cff
RGS
909
910# Default to not exiting when program finishes; print the return
911# value when the 'r' command is used to return from a subroutine.
55497cff 912$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 913
6b24a4b7
SF
914use vars qw($trace_to_depth);
915
5e2b42dd
SF
916# Default to 1E9 so it won't be limited to a certain recursion depth.
917$trace_to_depth = 1E9;
bdba49ad 918
69893cff
RGS
919=head1 OPTION PROCESSING
920
b570d64b
SF
921The debugger's options are actually spread out over the debugger itself and
922C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
923subs to be called with a value. To try to make this a little easier to
924manage, the debugger uses a few data structures to define what options
925are legal and how they are to be processed.
926
927First, the C<@options> array defines the I<names> of all the options that
928are to be accepted.
929
930=cut
931
932@options = qw(
5561b870 933 CommandSet HistFile HistSize
e22ea7cc
RF
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
939 AutoTrace TTY noTTY
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
584420f0 946 DollarCaretP
e22ea7cc 947);
d12a4851 948
584420f0 949@RememberOnROptions = qw(DollarCaretP);
d12a4851 950
69893cff
RGS
951=pod
952
953Second, C<optionVars> lists the variables that each option uses to save its
954state.
955
956=cut
957
6b24a4b7
SF
958use vars qw(%optionVars);
959
69893cff 960%optionVars = (
e22ea7cc
RF
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
973 frame => \$frame,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
5561b870
AK
980 HistFile => \$histfile,
981 HistSize => \$histsize,
69893cff
RGS
982);
983
984=pod
985
986Third, C<%optionAction> defines the subroutine to be called to process each
987option.
988
b570d64b 989=cut
69893cff 990
6b24a4b7
SF
991use vars qw(%optionAction);
992
69893cff
RGS
993%optionAction = (
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
997 TTY => \&TTY,
998 noTTY => \&noTTY,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1004 pager => \&pager,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1012);
1013
69893cff
RGS
1014=pod
1015
1016Last, the C<%optionRequire> notes modules that must be C<require>d if an
1017option is used.
1018
1019=cut
d338d6fe 1020
69893cff
RGS
1021# Note that this list is not complete: several options not listed here
1022# actually require that dumpvar.pl be loaded for them to work, but are
1023# not in the table. A subsequent patch will correct this problem; for
1024# the moment, we're just recommenting, and we are NOT going to change
1025# function.
6b24a4b7
SF
1026use vars qw(%optionRequire);
1027
eda6e075 1028%optionRequire = (
69893cff
RGS
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
e22ea7cc 1032);
69893cff
RGS
1033
1034=pod
1035
1036There are a number of initialization-related variables which can be set
1037by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038variable. These are:
1039
1040=over 4
1041
1042=item C<$rl> - readline control XXX needs more explanation
1043
1044=item C<$warnLevel> - whether or not debugger takes over warning handling
1045
1046=item C<$dieLevel> - whether or not debugger takes over die handling
1047
1048=item C<$signalLevel> - whether or not debugger takes over signal handling
1049
1050=item C<$pre> - preprompt actions (array reference)
1051
1052=item C<$post> - postprompt actions (array reference)
1053
1054=item C<$pretype>
1055
1056=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1057
1058=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1059
1060=back
1061
1062=cut
d338d6fe
PP
1063
1064# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1065$rl = 1 unless defined $rl;
1066$warnLevel = 1 unless defined $warnLevel;
1067$dieLevel = 1 unless defined $dieLevel;
1068$signalLevel = 1 unless defined $signalLevel;
1069$pre = [] unless defined $pre;
1070$post = [] unless defined $post;
1071$pretype = [] unless defined $pretype;
1072$CreateTTY = 3 unless defined $CreateTTY;
1073$CommandSet = '580' unless defined $CommandSet;
1074
2cbb2ee1
RGS
1075share($rl);
1076share($warnLevel);
1077share($dieLevel);
1078share($signalLevel);
1079share($pre);
1080share($post);
1081share($pretype);
1082share($rl);
1083share($CreateTTY);
1084share($CommandSet);
1085
69893cff
RGS
1086=pod
1087
1088The default C<die>, C<warn>, and C<signal> handlers are set up.
1089
1090=cut
055fd3a9 1091
d338d6fe
PP
1092warnLevel($warnLevel);
1093dieLevel($dieLevel);
1094signalLevel($signalLevel);
055fd3a9 1095
69893cff
RGS
1096=pod
1097
1098The pager to be used is needed next. We try to get it from the
5561b870 1099environment first. If it's not defined there, we try to find it in
69893cff
RGS
1100the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101then call the C<pager()> function to save the pager name.
1102
1103=cut
1104
1105# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1106pager(
e22ea7cc 1107
69893cff 1108 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1109 defined $ENV{PAGER}
1110 ? $ENV{PAGER}
69893cff
RGS
1111
1112 # If not, see if Config.pm defines it.
e22ea7cc
RF
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
69893cff
RGS
1116
1117 # If not, fall back to 'more'.
e22ea7cc
RF
1118 : 'more'
1119 )
1120 unless defined $pager;
69893cff
RGS
1121
1122=pod
1123
1124We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1125recall character (C<!> unless otherwise defined) and the shell escape
1126character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1127neither works in the debugger at the moment.
1128
1129=cut
1130
055fd3a9 1131setman();
69893cff
RGS
1132
1133# Set up defaults for command recall and shell escape (note:
1134# these currently don't work in linemode debugging).
2218c045
SF
1135recallCommand("!") unless defined $prc;
1136shellBang("!") unless defined $psh;
69893cff
RGS
1137
1138=pod
1139
1140We then set up the gigantic string containing the debugger help.
1141We also set the limit on the number of arguments we'll display during a
1142trace.
1143
1144=cut
1145
04e43a21 1146sethelp();
69893cff
RGS
1147
1148# If we didn't get a default for the length of eval/stack trace args,
1149# set it here.
1d06cb2d 1150$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1151
1152=head2 SETTING UP THE DEBUGGER GREETING
1153
be9a9b1d 1154The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1155running, and whether the current debugger is the primary or a child.
1156
1157If we are the primary, we just hang onto our pid so we'll have it when
1158or if we start a child debugger. If we are a child, we'll set things up
1159so we'll have a unique greeting and so the parent will give us our own
1160TTY later.
1161
1162We save the current contents of the C<PERLDB_PIDS> environment variable
1163because we mess around with it. We'll also need to hang onto it because
1164we'll need it if we restart.
1165
1166Child debuggers make a label out of the current PID structure recorded in
1167PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168yet so the parent will give them one later via C<resetterm()>.
1169
1170=cut
1171
e22ea7cc 1172# Save the current contents of the environment; we're about to
69893cff 1173# much with it. We'll need this if we have to restart.
6b24a4b7 1174use vars qw($ini_pids);
f1583d8f 1175$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1176
6b24a4b7
SF
1177use vars qw ($pids $term_pid);
1178
e22ea7cc
RF
1179if ( defined $ENV{PERLDB_PIDS} ) {
1180
69893cff 1181 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1183 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1184
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1187
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1189 # the same PID.
1190
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1192 $term_pid = $$;
1193 }
1194 else {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1196 $term_pid = -1;
1197 }
1198
69893cff
RGS
1199} ## end if (defined $ENV{PERLDB_PIDS...
1200else {
e22ea7cc
RF
1201
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
619a0444 1206 $pids = "[pid=$$]";
e22ea7cc 1207 $term_pid = $$;
f1583d8f 1208}
69893cff 1209
6b24a4b7 1210use vars qw($pidprompt);
f1583d8f 1211$pidprompt = '';
69893cff
RGS
1212
1213# Sets up $emacs as a synonym for $slave_editor.
6b24a4b7 1214use vars qw($slave_editor);
69893cff
RGS
1215*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1216
1217=head2 READING THE RC FILE
1218
b570d64b 1219The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1220running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1221
b570d64b 1222=cut
69893cff
RGS
1223
1224# As noted, this test really doesn't check accurately that the debugger
1225# is running at a terminal or not.
d338d6fe 1226
6b24a4b7 1227use vars qw($rcfile);
fb4d8a6c
SF
1228{
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1232}
1233
69893cff
RGS
1234=pod
1235
1236The debugger does a safety test of the file to be read. It must be owned
1237either by the current user or root, and must only be writable by the owner.
1238
1239=cut
1240
1241# This wraps a safety test around "do" to read and evaluate the init file.
1242#
055fd3a9
GS
1243# This isn't really safe, because there's a race
1244# between checking and opening. The solution is to
1245# open and fstat the handle, but then you have to read and
1246# eval the contents. But then the silly thing gets
69893cff
RGS
1247# your lexical scope, which is unfortunate at best.
1248sub safe_do {
055fd3a9
GS
1249 my $file = shift;
1250
1251 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
055fd3a9 1254
e22ea7cc 1255 unless ( is_safe_file($file) ) {
69893cff 1256 CORE::warn <<EO_GRIPE;
055fd3a9 1257perldb: Must not source insecure rcfile $file.
b570d64b 1258 You or the superuser must be the owner, and it must not
69893cff 1259 be writable by anyone but its owner.
055fd3a9 1260EO_GRIPE
69893cff
RGS
1261 return;
1262 } ## end unless (is_safe_file($file...
055fd3a9
GS
1263
1264 do $file;
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1266} ## end sub safe_do
055fd3a9 1267
69893cff
RGS
1268# This is the safety test itself.
1269#
055fd3a9
GS
1270# Verifies that owner is either real user or superuser and that no
1271# one but owner may write to it. This function is of limited use
1272# when called on a path instead of upon a handle, because there are
1273# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1274# eventually accessed is the same as the one tested.
055fd3a9
GS
1275# Assumes that the file's existence is not in doubt.
1276sub is_safe_file {
1277 my $path = shift;
69893cff 1278 stat($path) || return; # mysteriously vaporized
e22ea7cc 1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1280
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1283 return 1;
69893cff 1284} ## end sub is_safe_file
055fd3a9 1285
69893cff 1286# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1287# exists, we safely do it.
1288if ( -f $rcfile ) {
055fd3a9 1289 safe_do("./$rcfile");
69893cff 1290}
e22ea7cc 1291
69893cff 1292# If there isn't one here, try the user's home directory.
e22ea7cc 1293elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1294 safe_do("$ENV{HOME}/$rcfile");
1295}
e22ea7cc 1296
69893cff 1297# Else try the login directory.
e22ea7cc 1298elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1299 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1300}
1301
69893cff 1302# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1303if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1305}
1306
69893cff
RGS
1307=pod
1308
1309The last thing we do during initialization is determine which subroutine is
1310to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1311the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1312(darwin).
69893cff
RGS
1313
1314=cut
1315
1316# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1318# OS/2, or on Mac OS X. This may need some expansion.
1319
1320if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1321{
b570d64b 1322 if ( defined $remoteport ) {
11653f7f
JJ
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1325 }
1326 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1330 )
1331 {
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1333 }
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1336 }
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1341 )
1342 {
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1344 }
69893cff 1345} ## end if (not defined &get_fork_TTY...
e22ea7cc 1346
dbb46cec
DQ
1347# untaint $^O, which may have been tainted by the last statement.
1348# see bug [perl #24674]
e22ea7cc
RF
1349$^O =~ m/^(.*)\z/;
1350$^O = $1;
f1583d8f 1351
d12a4851 1352# Here begin the unreadable code. It needs fixing.
055fd3a9 1353
69893cff
RGS
1354=head2 RESTART PROCESSING
1355
1356This section handles the restart command. When the C<R> command is invoked, it
1357tries to capture all of the state it can into environment variables, and
1358then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360the R command stuffed into the environment variables.
1361
b570d64b 1362 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1374
1375We chug through all these variables and plug the values saved in them
1376back into the appropriate spots in the debugger.
1377
1378=cut
1379
6b24a4b7
SF
1380use vars qw(@hist @truehist %postponed_file @typeahead);
1381
e18a02a6 1382sub _restore_breakpoints_and_actions {
e22ea7cc 1383
e22ea7cc 1384 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1385
bdba49ad
SF
1386 for my $file_idx ( 0 .. $#had_breakpoints ) {
1387 my $filename = $had_breakpoints[$file_idx];
1388 my %pf = get_list("PERLDB_FILE_$file_idx");
1389 $postponed_file{ $filename } = \%pf if %pf;
1390 my @lines = sort {$a <=> $b} keys(%pf);
1391 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1392 for my $line_idx (0 .. $#lines) {
1393 _set_breakpoint_enabled_status(
1394 $filename,
1395 $lines[$line_idx],
1396 ($enabled_statuses[$line_idx] ? 1 : ''),
1397 );
1398 }
e22ea7cc 1399 }
69893cff 1400
e18a02a6
SF
1401 return;
1402}
1403
ca50076b
SF
1404sub _restore_options_after_restart
1405{
1406 my %options_map = get_list("PERLDB_OPT");
1407
1408 while ( my ( $opt, $val ) = each %options_map ) {
1409 $val =~ s/[\\\']/\\$1/g;
1410 parse_options("$opt'$val'");
1411 }
1412
1413 return;
1414}
1415
e18a02a6
SF
1416if ( exists $ENV{PERLDB_RESTART} ) {
1417
1418 # We're restarting, so we don't need the flag that says to restart anymore.
1419 delete $ENV{PERLDB_RESTART};
1420
1421 # $restart = 1;
1422 @hist = get_list('PERLDB_HIST');
1423 %break_on_load = get_list("PERLDB_ON_LOAD");
1424 %postponed = get_list("PERLDB_POSTPONE");
1425
1426 share(@hist);
1427 share(@truehist);
1428 share(%break_on_load);
1429 share(%postponed);
1430
1431 _restore_breakpoints_and_actions();
1432
69893cff 1433 # restore options
ca50076b 1434 _restore_options_after_restart();
69893cff
RGS
1435
1436 # restore original @INC
e22ea7cc
RF
1437 @INC = get_list("PERLDB_INC");
1438 @ini_INC = @INC;
1439
1440 # return pre/postprompt actions and typeahead buffer
1441 $pretype = [ get_list("PERLDB_PRETYPE") ];
1442 $pre = [ get_list("PERLDB_PRE") ];
1443 $post = [ get_list("PERLDB_POST") ];
1444 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
69893cff
RGS
1445} ## end if (exists $ENV{PERLDB_RESTART...
1446
1447=head2 SETTING UP THE TERMINAL
1448
1449Now, we'll decide how the debugger is going to interact with the user.
1450If there's no TTY, we set the debugger to run non-stop; there's not going
1451to be anyone there to enter commands.
1452
1453=cut
54d04a52 1454
6b24a4b7
SF
1455use vars qw($notty $runnonstop $console $tty $LINEINFO);
1456use vars qw($lineinfo $doccmd);
1457
d338d6fe 1458if ($notty) {
69893cff 1459 $runnonstop = 1;
2cbb2ee1 1460 share($runnonstop);
69893cff 1461}
d12a4851 1462
69893cff
RGS
1463=pod
1464
1465If there is a TTY, we have to determine who it belongs to before we can
1466proceed. If this is a slave editor or graphical debugger (denoted by
1467the first command-line switch being '-emacs'), we shift this off and
1468set C<$rl> to 0 (XXX ostensibly to do straight reads).
1469
1470=cut
1471
1472else {
e22ea7cc 1473
69893cff
RGS
1474 # Is Perl being run from a slave editor or graphical debugger?
1475 # If so, don't use readline, and set $slave_editor = 1.
e22ea7cc
RF
1476 $slave_editor =
1477 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) );
1478 $rl = 0, shift(@main::ARGV) if $slave_editor;
1479
1480 #require Term::ReadLine;
d12a4851 1481
69893cff
RGS
1482=pod
1483
1484We then determine what the console should be on various systems:
1485
1486=over 4
1487
1488=item * Cygwin - We use C<stdin> instead of a separate device.
1489
1490=cut
1491
e22ea7cc
RF
1492 if ( $^O eq 'cygwin' ) {
1493
69893cff
RGS
1494 # /dev/tty is binary. use stdin for textmode
1495 undef $console;
1496 }
1497
1498=item * Unix - use C</dev/tty>.
1499
1500=cut
1501
e22ea7cc 1502 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1503 $console = "/dev/tty";
1504 }
1505
1506=item * Windows or MSDOS - use C<con>.
1507
1508=cut
1509
e22ea7cc 1510 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1511 $console = "con";
1512 }
1513
69893cff
RGS
1514=item * VMS - use C<sys$command>.
1515
1516=cut
1517
1518 else {
e22ea7cc 1519
69893cff
RGS
1520 # everything else is ...
1521 $console = "sys\$command";
d12a4851 1522 }
69893cff
RGS
1523
1524=pod
1525
1526=back
1527
1528Several other systems don't use a specific console. We C<undef $console>
1529for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1530with a slave editor, Epoc).
1531
1532=cut
d12a4851 1533
e22ea7cc
RF
1534 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1535
69893cff 1536 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1537 $console = undef;
1538 }
1539
1540 if ( $^O eq 'NetWare' ) {
d12a4851 1541
69893cff
RGS
1542 # /dev/tty is binary. use stdin for textmode
1543 $console = undef;
1544 }
d12a4851 1545
69893cff
RGS
1546 # In OS/2, we need to use STDIN to get textmode too, even though
1547 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1548 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1549 { # In OS/2
1550 $console = undef;
1551 }
1552
1553 # EPOC also falls into the 'got to use STDIN' camp.
1554 if ( $^O eq 'epoc' ) {
1555 $console = undef;
1556 }
d12a4851 1557
69893cff
RGS
1558=pod
1559
1560If there is a TTY hanging around from a parent, we use that as the console.
1561
1562=cut
1563
e22ea7cc 1564 $console = $tty if defined $tty;
d12a4851 1565
b570d64b 1566=head2 SOCKET HANDLING
69893cff
RGS
1567
1568The debugger is capable of opening a socket and carrying out a debugging
1569session over the socket.
1570
1571If C<RemotePort> was defined in the options, the debugger assumes that it
1572should try to start a debugging session on that port. It builds the socket
1573and then tries to connect the input and output filehandles to it.
1574
1575=cut
1576
1577 # Handle socket stuff.
e22ea7cc
RF
1578
1579 if ( defined $remoteport ) {
1580
69893cff
RGS
1581 # If RemotePort was defined in the options, connect input and output
1582 # to the socket.
11653f7f 1583 $IN = $OUT = connect_remoteport();
69893cff
RGS
1584 } ## end if (defined $remoteport)
1585
1586=pod
1587
1588If no C<RemotePort> was defined, and we want to create a TTY on startup,
1589this is probably a situation where multiple debuggers are running (for example,
1590a backticked command that starts up another debugger). We create a new IN and
1591OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1592and if we can.
1593
1594=cut
1595
1596 # Non-socket.
1597 else {
e22ea7cc 1598
69893cff
RGS
1599 # Two debuggers running (probably a system or a backtick that invokes
1600 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1601 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1602 # know how, and we can.
e22ea7cc
RF
1603 create_IN_OUT(4) if $CreateTTY & 4;
1604 if ($console) {
1605
69893cff 1606 # If we have a console, check to see if there are separate ins and
cd1191f1 1607 # outs to open. (They are assumed identical if not.)
69893cff 1608
e22ea7cc
RF
1609 my ( $i, $o ) = split /,/, $console;
1610 $o = $i unless defined $o;
69893cff 1611
69893cff 1612 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1613 open( IN, "+<$i" )
1614 || open( IN, "<$i" )
1615 || open( IN, "<&STDIN" );
1616
69893cff
RGS
1617 # read/write/create/clobber out, or write/create/clobber out,
1618 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1619 open( OUT, "+>$o" )
1620 || open( OUT, ">$o" )
1621 || open( OUT, ">&STDERR" )
1622 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1623
1624 } ## end if ($console)
1625 elsif ( not defined $console ) {
1626
1627 # No console. Open STDIN.
1628 open( IN, "<&STDIN" );
1629
1630 # merge with STDERR, or with STDOUT.
1631 open( OUT, ">&STDERR" )
1632 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1633 $console = 'STDIN/OUT';
69893cff
RGS
1634 } ## end elsif (not defined $console)
1635
1636 # Keep copies of the filehandles so that when the pager runs, it
1637 # can close standard input without clobbering ours.
e22ea7cc
RF
1638 $IN = \*IN, $OUT = \*OUT if $console or not defined $console;
1639 } ## end elsif (from if(defined $remoteport))
1640
1641 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1642 $OUT->autoflush(1);
e22ea7cc
RF
1643
1644 # Line info goes to debugger output unless pointed elsewhere.
1645 # Pointing elsewhere makes it possible for slave editors to
1646 # keep track of file and position. We have both a filehandle
1647 # and a I/O description to keep track of.
1648 $LINEINFO = $OUT unless defined $LINEINFO;
1649 $lineinfo = $console unless defined $lineinfo;
2cbb2ee1 1650 # share($LINEINFO); # <- unable to share globs
b570d64b 1651 share($lineinfo); #
e22ea7cc 1652
69893cff
RGS
1653=pod
1654
1655To finish initialization, we show the debugger greeting,
1656and then call the C<afterinit()> subroutine if there is one.
1657
1658=cut
d12a4851 1659
e22ea7cc
RF
1660 # Show the debugger greeting.
1661 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1662 unless ($runnonstop) {
1663 local $\ = '';
1664 local $, = '';
1665 if ( $term_pid eq '-1' ) {
1666 print $OUT "\nDaughter DB session started...\n";
1667 }
1668 else {
1669 print $OUT "\nLoading DB routines from $header\n";
1670 print $OUT (
1671 "Editor support ",
1672 $slave_editor ? "enabled" : "available", ".\n"
1673 );
1674 print $OUT
1f874cb6 1675"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1676 } ## end else [ if ($term_pid eq '-1')
1677 } ## end unless ($runnonstop)
1678} ## end else [ if ($notty)
1679
1680# XXX This looks like a bug to me.
1681# Why copy to @ARGS and then futz with @args?
d338d6fe 1682@ARGS = @ARGV;
6b24a4b7 1683# for (@args) {
69893cff
RGS
1684 # Make sure backslashes before single quotes are stripped out, and
1685 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1686 # s/\'/\\\'/g; # removed while not justified understandably
1687 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1688# }
d338d6fe 1689
e22ea7cc 1690# If there was an afterinit() sub defined, call it. It will get
69893cff 1691# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1692if ( defined &afterinit ) { # May be defined in $rcfile
69893cff 1693 &afterinit();
d338d6fe 1694}
e22ea7cc 1695
69893cff 1696# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1697use vars qw($I_m_init);
1698
43aed9ee
IZ
1699$I_m_init = 1;
1700
d338d6fe
PP
1701############################################################ Subroutines
1702
69893cff
RGS
1703=head1 SUBROUTINES
1704
1705=head2 DB
1706
1707This gigantic subroutine is the heart of the debugger. Called before every
1708statement, its job is to determine if a breakpoint has been reached, and
1709stop if so; read commands from the user, parse them, and execute
b468dcb6 1710them, and then send execution off to the next statement.
69893cff
RGS
1711
1712Note that the order in which the commands are processed is very important;
1713some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1714to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1715but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1716see what's happening in any given command.
1717
1718=cut
1719
6b24a4b7
SF
1720use vars qw(
1721 $action
1722 %alias
1723 $cmd
1724 $doret
1725 $fall_off_end
1726 $file
1727 $filename_ini
1728 $finished
1729 %had_breakpoints
1730 $incr
1731 $laststep
1732 $level
1733 $max
1734 @old_watch
1735 $package
1736 $rc
1737 $sh
1738 @stack
1739 $stack_depth
1740 @to_watch
1741 $try
2c247e84 1742 $end
6b24a4b7
SF
1743);
1744
d338d6fe 1745sub DB {
69893cff 1746
2cbb2ee1
RGS
1747 # lock the debugger and get the thread id for the prompt
1748 lock($DBGR);
1749 my $tid;
6b24a4b7
SF
1750 my $position;
1751 my ($prefix, $after, $infix);
1752 my $pat;
6b24a4b7 1753
2cbb2ee1 1754 if ($ENV{PERL5DB_THREADED}) {
878090d5 1755 $tid = eval { "[".threads->tid."]" };
2cbb2ee1
RGS
1756 }
1757
69893cff 1758 # Check for whether we should be running continuously or not.
36477c24 1759 # _After_ the perl program is compiled, $single is set to 1:
e22ea7cc
RF
1760 if ( $single and not $second_time++ ) {
1761
69893cff 1762 # Options say run non-stop. Run until we get an interrupt.
e22ea7cc
RF
1763 if ($runnonstop) { # Disable until signal
1764 # If there's any call stack in place, turn off single
1765 # stepping into subs throughout the stack.
2c247e84 1766 for my $i (0 .. $stack_depth) {
72d7d80d 1767 $stack[ $i ] &= ~1;
e22ea7cc
RF
1768 }
1769
69893cff 1770 # And we are now no longer in single-step mode.
e22ea7cc 1771 $single = 0;
69893cff
RGS
1772
1773 # If we simply returned at this point, we wouldn't get
1774 # the trace info. Fall on through.
e22ea7cc 1775 # return;
69893cff
RGS
1776 } ## end if ($runnonstop)
1777
e22ea7cc
RF
1778 elsif ($ImmediateStop) {
1779
1780 # We are supposed to stop here; XXX probably a break.
1781 $ImmediateStop = 0; # We've processed it; turn it off
1782 $signal = 1; # Simulate an interrupt to force
1783 # us into the command loop
69893cff
RGS
1784 }
1785 } ## end if ($single and not $second_time...
1786
1787 # If we're in single-step mode, or an interrupt (real or fake)
1788 # has occurred, turn off non-stop mode.
1789 $runnonstop = 0 if $single or $signal;
1790
1791 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1792 # The code being debugged may have altered them.
d338d6fe 1793 &save;
69893cff
RGS
1794
1795 # Since DB::DB gets called after every line, we can use caller() to
1796 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1797 # caller is returning all the extra information when called from the
69893cff 1798 # debugger.
e22ea7cc 1799 local ( $package, $filename, $line ) = caller;
6b24a4b7 1800 $filename_ini = $filename;
69893cff
RGS
1801
1802 # set up the context for DB::eval, so it can properly execute
1803 # code on behalf of the user. We add the package in so that the
1804 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1805 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1806
1807 # Create an alias to the active file magical array to simplify
1808 # the code here.
e22ea7cc 1809 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1810
69893cff 1811 # Last line in the program.
55783941 1812 $max = $#dbline;
69893cff
RGS
1813
1814 # if we have something here, see if we should break.
e22ea7cc 1815 {
72d7d80d
SF
1816 # $stop is lexical and local to this block - $action on the other hand
1817 # is global.
1818 my $stop;
e22ea7cc 1819
72d7d80d
SF
1820 if ( $dbline{$line}
1821 && _is_breakpoint_enabled($filename, $line)
1822 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1823 {
e22ea7cc 1824
72d7d80d
SF
1825 # Stop if the stop criterion says to just stop.
1826 if ( $stop eq '1' ) {
1827 $signal |= 1;
5d5d9ea3 1828 }
72d7d80d
SF
1829
1830 # It's a conditional stop; eval it in the user's context and
1831 # see if we should stop. If so, remove the one-time sigil.
1832 elsif ($stop) {
1833 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1834 &eval;
1835 # If the breakpoint is temporary, then delete its enabled status.
1836 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1837 _cancel_breakpoint_temp_enabled_status($filename, $line);
1838 }
1839 }
1840 } ## end if ($dbline{$line} && ...
1841 }
69893cff
RGS
1842
1843 # Preserve the current stop-or-not, and see if any of the W
1844 # (watch expressions) has changed.
36477c24 1845 my $was_signal = $signal;
69893cff
RGS
1846
1847 # If we have any watch expressions ...
e22ea7cc 1848 if ( $trace & 2 ) {
2c247e84 1849 for my $n (0 .. $#to_watch) {
e22ea7cc
RF
1850 $evalarg = $to_watch[$n];
1851 local $onetimeDump; # Tell DB::eval() to not output results
69893cff
RGS
1852
1853 # Fix context DB::eval() wants to return an array, but
1854 # we need a scalar here.
e22ea7cc
RF
1855 my ($val) = join( "', '", &eval );
1856 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
69893cff
RGS
1857
1858 # Did it change?
e22ea7cc
RF
1859 if ( $val ne $old_watch[$n] ) {
1860
69893cff 1861 # Yep! Show the difference, and fake an interrupt.
e22ea7cc
RF
1862 $signal = 1;
1863 print $OUT <<EOP;
405ff068 1864Watchpoint $n:\t$to_watch[$n] changed:
69893cff
RGS
1865 old value:\t$old_watch[$n]
1866 new value:\t$val
6027b9a3 1867EOP
e22ea7cc 1868 $old_watch[$n] = $val;
69893cff 1869 } ## end if ($val ne $old_watch...
2c247e84 1870 } ## end for my $n (0 ..
69893cff
RGS
1871 } ## end if ($trace & 2)
1872
1873=head2 C<watchfunction()>
1874
1875C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1876function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1877current package, filename, and line as its parameters.
1878
b570d64b 1879The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1880debugger's context, so it has access to all of the debugger's internal
1881data structures and functions.
1882
1883C<watchfunction()> can control the debugger's actions. Any of the following
1884will cause the debugger to return control to the user's program after
1885C<watchfunction()> executes:
1886
b570d64b 1887=over 4
69893cff 1888
be9a9b1d
AT
1889=item *
1890
1891Returning a false value from the C<watchfunction()> itself.
1892
1893=item *
1894
1895Altering C<$single> to a false value.
1896
1897=item *
69893cff 1898
be9a9b1d 1899Altering C<$signal> to a false value.
69893cff 1900
be9a9b1d 1901=item *
69893cff 1902
be9a9b1d 1903Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1904check for C<watchfunction()>. This can be done with
1905
1906 $trace &= ~4;
1907
1908=back
1909
1910=cut
1911
e22ea7cc 1912 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1913 # current package, filename, and line. The function executes in
1914 # the DB:: package.
e22ea7cc
RF
1915 if ( $trace & 4 ) { # User-installed watch
1916 return
1917 if watchfunction( $package, $filename, $line )
1918 and not $single
1919 and not $was_signal
1920 and not( $trace & ~4 );
69893cff
RGS
1921 } ## end if ($trace & 4)
1922
e22ea7cc 1923 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1924 # turn off the signal now.
6027b9a3 1925 $was_signal = $signal;
69893cff
RGS
1926 $signal = 0;
1927
1928=head2 GETTING READY TO EXECUTE COMMANDS
1929
1930The debugger decides to take control if single-step mode is on, the
1931C<t> command was entered, or the user generated a signal. If the program
1932has fallen off the end, we set things up so that entering further commands
1933won't cause trouble, and we say that the program is over.
1934
1935=cut
1936
8dc67a69
SF
1937 # Make sure that we always print if asked for explicitly regardless
1938 # of $trace_to_depth .
1939 my $explicit_stop = ($single || $was_signal);
1940
69893cff
RGS
1941 # Check to see if we should grab control ($single true,
1942 # trace set appropriately, or we got a signal).
8dc67a69 1943 if ( $explicit_stop || ( $trace & 1 ) ) {
e22ea7cc 1944
69893cff 1945 # Yes, grab control.
e22ea7cc
RF
1946 if ($slave_editor) {
1947
69893cff 1948 # Tell the editor to update its position.
e22ea7cc
RF
1949 $position = "\032\032$filename:$line:0\n";
1950 print_lineinfo($position);
1951 }
69893cff
RGS
1952
1953=pod
1954
b570d64b 1955Special check: if we're in package C<DB::fake>, we've gone through the
69893cff
RGS
1956C<END> block at least once. We set up everything so that we can continue
1957to enter commands and have a valid context to be in.
1958
1959=cut
1960
e22ea7cc 1961 elsif ( $package eq 'DB::fake' ) {
69893cff 1962
69893cff 1963 # Fallen off the end already.
e22ea7cc
RF
1964 $term || &setterm;
1965 print_help(<<EOP);
405ff068 1966Debugged program terminated. Use B<q> to quit or B<R> to restart,
6b27b0a0 1967 use B<o> I<inhibit_exit> to avoid stopping after program termination,
b570d64b 1968 B<h q>, B<h R> or B<h o> to get additional info.
405ff068 1969EOP
e22ea7cc 1970
69893cff 1971 # Set the DB::eval context appropriately.
e22ea7cc 1972 $package = 'main';
6b24a4b7 1973 $usercontext = _calc_usercontext($package);
69893cff 1974 } ## end elsif ($package eq 'DB::fake')
e219e2fb 1975
69893cff 1976=pod
e219e2fb 1977
69893cff
RGS
1978If the program hasn't finished executing, we scan forward to the
1979next executable line, print that out, build the prompt from the file and line
b570d64b 1980number information, and print that.
e219e2fb 1981
69893cff
RGS
1982=cut
1983
e22ea7cc
RF
1984 else {
1985
8dc67a69 1986
69893cff
RGS
1987 # Still somewhere in the midst of execution. Set up the
1988 # debugger prompt.
1989 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
e22ea7cc 1990 # Perl 5 ones (sorry, we don't print Klingon
69893cff
RGS
1991 #module names)
1992
6b24a4b7 1993 $prefix = $sub =~ /::/ ? "" : ($package . '::');
e22ea7cc
RF
1994 $prefix .= "$sub($filename:";
1995 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
1996
1997 # Break up the prompt if it's really long.
e22ea7cc
RF
1998 if ( length($prefix) > 30 ) {
1999 $position = "$prefix$line):\n$line:\t$dbline[$line]$after";
2000 $prefix = "";
2001 $infix = ":\t";
2002 }
2003 else {
2004 $infix = "):\t";
2005 $position = "$prefix$line$infix$dbline[$line]$after";
2006 }
69893cff
RGS
2007
2008 # Print current line info, indenting if necessary.
e22ea7cc
RF
2009 if ($frame) {
2010 print_lineinfo( ' ' x $stack_depth,
2011 "$line:\t$dbline[$line]$after" );
2012 }
2013 else {
8dc67a69 2014 depth_print_lineinfo($explicit_stop, $position);
e22ea7cc 2015 }
69893cff
RGS
2016
2017 # Scan forward, stopping at either the end or the next
2018 # unbreakable line.
72d7d80d 2019 for ( my $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i )
e22ea7cc 2020 { #{ vi
69893cff
RGS
2021
2022 # Drop out on null statements, block closers, and comments.
2023 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/;
2024
2025 # Drop out if the user interrupted us.
2026 last if $signal;
2027
2028 # Append a newline if the line doesn't have one. Can happen
2029 # in eval'ed text, for instance.
e22ea7cc 2030 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" );
69893cff
RGS
2031
2032 # Next executable line.
6b24a4b7 2033 my $incr_pos = "$prefix$i$infix$dbline[$i]$after";
69893cff
RGS
2034 $position .= $incr_pos;
2035 if ($frame) {
e22ea7cc 2036
69893cff 2037 # Print it indented if tracing is on.
e22ea7cc
RF
2038 print_lineinfo( ' ' x $stack_depth,
2039 "$i:\t$dbline[$i]$after" );
69893cff
RGS
2040 }
2041 else {
8dc67a69 2042 depth_print_lineinfo($explicit_stop, $incr_pos);
69893cff 2043 }
72d7d80d 2044 } ## end for ($i = $line + 1 ; $i...
69893cff
RGS
2045 } ## end else [ if ($slave_editor)
2046 } ## end if ($single || ($trace...
2047
2048=pod
2049
2050If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2051If there are any preprompt actions, execute those as well.
e219e2fb
RF
2052
2053=cut
2054
69893cff
RGS
2055 # If there's an action, do it now.
2056 $evalarg = $action, &eval if $action;
e219e2fb 2057
69893cff
RGS
2058 # Are we nested another level (e.g., did we evaluate a function
2059 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2060 if ( $single || $was_signal ) {
2061
69893cff 2062 # Yes, go down a level.
e22ea7cc 2063 local $level = $level + 1;
69893cff
RGS
2064
2065 # Do any pre-prompt actions.
e22ea7cc
RF
2066 foreach $evalarg (@$pre) {
2067 &eval;
2068 }
69893cff
RGS
2069
2070 # Complain about too much recursion if we passed the limit.
e22ea7cc 2071 print $OUT $stack_depth . " levels deep in subroutine calls!\n"
69893cff
RGS
2072 if $single & 4;
2073
2074 # The line we're currently on. Set $incr to -1 to stay here
2075 # until we get a command that tells us to advance.
e22ea7cc
RF
2076 $start = $line;
2077 $incr = -1; # for backward motion.
69893cff
RGS
2078
2079 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2080 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2081
2082=head2 WHERE ARE WE?
2083
2084XXX Relocate this section?
2085
2086The debugger normally shows the line corresponding to the current line of
2087execution. Sometimes, though, we want to see the next line, or to move elsewhere
2088in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2089
be9a9b1d
AT
2090C<$incr> controls by how many lines the I<current> line should move forward
2091after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2092line shouldn't change.
2093
be9a9b1d 2094C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2095move forwards or backwards from when doing an C<L> or C<-> command.
2096
2097C<$max> tells the debugger where the last line of the current file is. It's
2098used to terminate loops most often.
2099
2100=head2 THE COMMAND LOOP
2101
2102Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2103in two parts:
2104
2105=over 4
2106
be9a9b1d
AT
2107=item *
2108
2109The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2110reads a command and then executes it.
2111
be9a9b1d
AT
2112=item *
2113
2114The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2115is wholly contained inside the C<CMD> block and only executes a command.
2116Used to handle commands running inside a pager.
2117
2118=back
2119
2120So why have two labels to restart the loop? Because sometimes, it's easier to
2121have a command I<generate> another command and then re-execute the loop to do
2122the new command. This is faster, but perhaps a bit more convoluted.
2123
2124=cut
2125
2126 # The big command dispatch loop. It keeps running until the
2127 # user yields up control again.
2128 #
2129 # If we have a terminal for input, and we get something back
2130 # from readline(), keep on processing.
6b24a4b7
SF
2131 my $piped;
2132 my $selected;
2133
e22ea7cc
RF
2134 CMD:
2135 while (
2136
69893cff 2137 # We have a terminal, or can get one ...
e22ea7cc
RF
2138 ( $term || &setterm ),
2139
69893cff 2140 # ... and it belogs to this PID or we get one for this PID ...
e22ea7cc
RF
2141 ( $term_pid == $$ or resetterm(1) ),
2142
69893cff 2143 # ... and we got a line of command input ...
e22ea7cc
RF
2144 defined(
2145 $cmd = &readline(
2cbb2ee1 2146 "$pidprompt $tid DB"
e22ea7cc
RF
2147 . ( '<' x $level )
2148 . ( $#hist + 1 )
2149 . ( '>' x $level ) . " "
69893cff
RGS
2150 )
2151 )
2152 )
2153 {
e22ea7cc 2154
2cbb2ee1 2155 share($cmd);
69893cff
RGS
2156 # ... try to execute the input as debugger commands.
2157
2158 # Don't stop running.
2159 $single = 0;
2160
2161 # No signal is active.
2162 $signal = 0;
2163
2164 # Handle continued commands (ending with \):
3d7a2a93 2165 if ($cmd =~ s/\\\z/\n/) {
e22ea7cc
RF
2166 $cmd .= &readline(" cont: ");
2167 redo CMD;
3d7a2a93 2168 }
69893cff
RGS
2169
2170=head4 The null command
2171
be9a9b1d 2172A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2173command out of C<$laststep> (where it was recorded previously), and copy it
2174back into C<$cmd> to be executed below. If there wasn't any previous command,
2175we'll do nothing below (no command will match). If there was, we also save it
2176in the command history and fall through to allow the command parsing to pick
2177it up.
2178
2179=cut
2180
2181 # Empty input means repeat the last command.
e22ea7cc
RF
2182 $cmd =~ /^$/ && ( $cmd = $laststep );
2183 chomp($cmd); # get rid of the annoying extra newline
2184 push( @hist, $cmd ) if length($cmd) > 1;
2185 push( @truehist, $cmd );
2cbb2ee1
RGS
2186 share(@hist);
2187 share(@truehist);
e22ea7cc
RF
2188
2189 # This is a restart point for commands that didn't arrive
2190 # via direct user input. It allows us to 'redo PIPE' to
2191 # re-execute command processing without reading a new command.
69893cff 2192 PIPE: {
e22ea7cc
RF
2193 $cmd =~ s/^\s+//s; # trim annoying leading whitespace
2194 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace
6b24a4b7 2195 my ($i) = split( /\s+/, $cmd );
69893cff
RGS
2196
2197=head3 COMMAND ALIASES
2198
2199The debugger can create aliases for commands (these are stored in the
2200C<%alias> hash). Before a command is executed, the command loop looks it up
2201in the alias hash and substitutes the contents of the alias for the command,
2202completely replacing it.
2203
2204=cut
2205
2206 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2207 if ( $alias{$i} ) {
2208
69893cff
RGS
2209 # Squelch signal handling; we want to keep control here
2210 # if something goes loco during the alias eval.
2211 local $SIG{__DIE__};
2212 local $SIG{__WARN__};
2213
2214 # This is a command, so we eval it in the DEBUGGER's
2215 # scope! Otherwise, we can't see the special debugger
2216 # variables, or get to the debugger's subs. (Well, we
2217 # _could_, but why make it even more complicated?)
2218 eval "\$cmd =~ $alias{$i}";
2219 if ($@) {
2220 local $\ = '';
1f874cb6 2221 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2222 next CMD;
2223 }
2224 } ## end if ($alias{$i})
2225
2226=head3 MAIN-LINE COMMANDS
2227
2228All of these commands work up to and after the program being debugged has
b570d64b 2229terminated.
69893cff
RGS
2230
2231=head4 C<q> - quit
2232
b570d64b 2233Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2234try to execute further, cleaning any restart-related stuff out of the
2235environment, and executing with the last value of C<$?>.
2236
2237=cut
2238
3d7a2a93 2239 if ($cmd eq 'q') {
69893cff
RGS
2240 $fall_off_end = 1;
2241 clean_ENV();
2242 exit $?;
3d7a2a93 2243 }
69893cff 2244
611272bb 2245=head4 C<t> - trace [n]
69893cff
RGS
2246
2247Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2248If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2249
2250=cut
2251
3d7a2a93 2252 if (my ($levels) = $cmd =~ /\At(?:\s+(\d+))?\z/) {
e22ea7cc
RF
2253 $trace ^= 1;
2254 local $\ = '';
611272bb 2255 $trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
e22ea7cc 2256 print $OUT "Trace = "
611272bb
PS
2257 . ( ( $trace & 1 )
2258 ? ( $levels ? "on (to level $trace_to_depth)" : "on" )
2259 : "off" ) . "\n";
e22ea7cc 2260 next CMD;
3d7a2a93 2261 }
69893cff
RGS
2262
2263=head4 C<S> - list subroutines matching/not matching a pattern
2264
2265Walks through C<%sub>, checking to see whether or not to print the name.
2266
2267=cut
2268
826b9a2e
SF
2269 if (my ($print_all_subs, $should_reverse, $Spatt)
2270 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2271 # $Spatt is the pattern (if any) to use.
2272 # Reverse scan?
2273 my $Srev = defined $should_reverse;
2274 # No args - print all subs.
2275 my $Snocheck = !defined $print_all_subs;
69893cff
RGS
2276
2277 # Need to make these sane here.
e22ea7cc
RF
2278 local $\ = '';
2279 local $, = '';
69893cff
RGS
2280
2281 # Search through the debugger's magical hash of subs.
2282 # If $nocheck is true, just print the sub name.
2283 # Otherwise, check it against the pattern. We then use
2284 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2285 foreach $subname ( sort( keys %sub ) ) {
2286 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2287 print $OUT $subname, "\n";
2288 }
2289 }
2290 next CMD;
826b9a2e 2291 }
69893cff
RGS
2292
2293=head4 C<X> - list variables in current package
2294
b570d64b 2295Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2296appropriate C<V> command and fall through.
2297
2298=cut
2299
e22ea7cc 2300 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2301
2302=head4 C<V> - list variables
2303
b570d64b 2304Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2305
2306=cut
2307
2308 # Bare V commands get the currently-being-debugged package
2309 # added.
826b9a2e 2310 if ($cmd eq "V") {
e22ea7cc 2311 $cmd = "V $package";
826b9a2e 2312 }
69893cff
RGS
2313
2314 # V - show variables in package.
826b9a2e
SF
2315 if (my ($new_packname, $new_vars_str) =
2316 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
e22ea7cc 2317
69893cff
RGS
2318 # Save the currently selected filehandle and
2319 # force output to debugger's filehandle (dumpvar
2320 # just does "print" for output).
6b24a4b7 2321 my $savout = select($OUT);
69893cff
RGS
2322
2323 # Grab package name and variables to dump.
826b9a2e
SF
2324 $packname = $new_packname;
2325 my @vars = split( ' ', $new_vars_str );
69893cff
RGS
2326
2327 # If main::dumpvar isn't here, get it.
e81465be 2328 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2329 if ( defined &main::dumpvar ) {
2330
69893cff
RGS
2331 # We got it. Turn off subroutine entry/exit messages
2332 # for the moment, along with return values.
e22ea7cc
RF
2333 local $frame = 0;
2334 local $doret = -2;
69893cff
RGS
2335
2336 # must detect sigpipe failures - not catching
2337 # then will cause the debugger to die.
2338 eval {
2339 &main::dumpvar(
2340 $packname,
2341 defined $option{dumpDepth}
e22ea7cc
RF
2342 ? $option{dumpDepth}
2343 : -1, # assume -1 unless specified
69893cff 2344 @vars
e22ea7cc
RF
2345 );
2346 };
2347
2348 # The die doesn't need to include the $@, because
2349 # it will automatically get propagated for us.
2350 if ($@) {
2351 die unless $@ =~ /dumpvar print failed/;
2352 }
2353 } ## end if (defined &main::dumpvar)
2354 else {
2355
2356 # Couldn't load dumpvar.
2357 print $OUT "dumpvar.pl not available.\n";
2358 }
69893cff 2359
69893cff 2360 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2361 select($savout);
2362 next CMD;
826b9a2e 2363 }
69893cff
RGS
2364
2365=head4 C<x> - evaluate and print an expression
2366
2367Hands the expression off to C<DB::eval>, setting it up to print the value
2368via C<dumpvar.pl> instead of just printing it directly.
2369
2370=cut
2371
826b9a2e 2372 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2373 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2374
2375 # handle special "x 3 blah" syntax XXX propagate
2376 # doc back to special variables.
826b9a2e 2377 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2378 $onetimedumpDepth = $1;
2379 }
826b9a2e 2380 }
69893cff
RGS
2381
2382=head4 C<m> - print methods
2383
2384Just uses C<DB::methods> to determine what methods are available.
2385
2386=cut
2387
826b9a2e 2388 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2389 methods($1);
2390 next CMD;
826b9a2e 2391 }
69893cff
RGS
2392
2393 # m expr - set up DB::eval to do the work
826b9a2e 2394 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2395 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2396 }
69893cff
RGS
2397
2398=head4 C<f> - switch files
2399
2400=cut
2401
826b9a2e 2402 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2403 $file =~ s/\s+$//;
69893cff
RGS
2404
2405 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2406 if ( !$file ) {
2407 print $OUT
2408 "The old f command is now the r command.\n"; # hint
2409 print $OUT "The new f command switches filenames.\n";
2410 next CMD;
2411 } ## end if (!$file)
69893cff
RGS
2412
2413 # if not in magic file list, try a close match.
e22ea7cc
RF
2414 if ( !defined $main::{ '_<' . $file } ) {
2415 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2416 {
2417 $try = substr( $try, 2 );
1f874cb6 2418 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2419 $file = $try;
2420 }
2421 } ## end if (($try) = grep(m#^_<.*$file#...
2422 } ## end if (!defined $main::{ ...
69893cff
RGS
2423
2424 # If not successfully switched now, we failed.
e22ea7cc 2425 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2426 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2427 next CMD;
2428 }
69893cff 2429
e22ea7cc
RF
2430 # We switched, so switch the debugger internals around.
2431 elsif ( $file ne $filename ) {
2432 *dbline = $main::{ '_<' . $file };
2433 $max = $#dbline;
2434 $filename = $file;
2435 $start = 1;
2436 $cmd = "l";
2437 } ## end elsif ($file ne $filename)
2438
2439 # We didn't switch; say we didn't.
2440 else {
2441 print $OUT "Already in $file.\n";
2442 next CMD;
2443 }
826b9a2e 2444 }
69893cff
RGS
2445
2446=head4 C<.> - return to last-executed line.
2447
2448We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2449and then we look up the line in the magical C<%dbline> hash.
2450
2451=cut
2452
2453 # . command.
826b9a2e 2454 if ($cmd eq '.') {
e22ea7cc 2455 $incr = -1; # stay at current line
69893cff
RGS
2456
2457 # Reset everything to the old location.
e22ea7cc
RF
2458 $start = $line;
2459 $filename = $filename_ini;
2460 *dbline = $main::{ '_<' . $filename };
2461 $max = $#dbline;
69893cff
RGS
2462
2463 # Now where are we?
e22ea7cc
RF
2464 print_lineinfo($position);
2465 next CMD;
826b9a2e 2466 }
69893cff
RGS
2467
2468=head4 C<-> - back one window
2469
2470We change C<$start> to be one window back; if we go back past the first line,
2471we set it to be the first line. We ser C<$incr> to put us back at the
2472currently-executing line, and then put a C<l $start +> (list one window from
2473C<$start>) in C<$cmd> to be executed later.
2474
2475=cut
2476
2477 # - - back a window.
826b9a2e 2478 if ($cmd eq '-') {
e22ea7cc 2479
69893cff 2480 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2481 $start -= $incr + $window + 1;
2482 $start = 1 if $start <= 0;
2483 $incr = $window - 1;
69893cff
RGS
2484
2485 # Generate and execute a "l +" command (handled below).
e22ea7cc 2486 $cmd = 'l ' . ($start) . '+';
826b9a2e 2487 }
69893cff
RGS
2488
2489=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>, {, {{>
2490
2491In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2492problems, most notably that the default case of several commands destroying
2493the user's work in setting watchpoints, actions, etc. We wanted, however, to
2494retain the old commands for those who were used to using them or who preferred
2495them. At this point, we check for the new commands and call C<cmd_wrapper> to
2496deal with them instead of processing them in-line.
2497
2498=cut
2499
2500 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2501 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2502 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2503 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2504 next CMD;
826b9a2e 2505 }
69893cff
RGS
2506
2507=head4 C<y> - List lexicals in higher scope
2508
826b9a2e 2509Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2510above the current one and then displays then using C<dumpvar.pl>.
2511
2512=cut
2513
826b9a2e
SF
2514 if (my ($match_level, $match_vars)
2515 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2516
2517 # See if we've got the necessary support.
2518 eval { require PadWalker; PadWalker->VERSION(0.08) }
2519 or &warn(
2520 $@ =~ /locate/
2521 ? "PadWalker module not found - please install\n"
2522 : $@
2523 )
2524 and next CMD;
2525
2526 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2527 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2528 defined &main::dumpvar
2529 or print $OUT "dumpvar.pl not available.\n"
2530 and next CMD;
2531
2532 # Got all the modules we need. Find them and print them.
826b9a2e 2533 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2534
2535 # Find the pad.
826b9a2e 2536 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2537
2538 # Oops. Can't find it.
2539 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2540
2541 # Show the desired vars with dumplex().
2542 my $savout = select($OUT);
2543
2544 # Have dumplex dump the lexicals.
e22ea7cc 2545 dumpvar::dumplex( $_, $h->{$_},
69893cff 2546 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2547 @vars )
2548 for sort keys %$h;
69893cff
RGS
2549 select($savout);
2550 next CMD;
826b9a2e 2551 }
69893cff
RGS
2552
2553=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2554
2555All of the commands below this point don't work after the program being
2556debugged has ended. All of them check to see if the program has ended; this
2557allows the commands to be relocated without worrying about a 'line of
2558demarcation' above which commands can be entered anytime, and below which
2559they can't.
2560
2561=head4 C<n> - single step, but don't trace down into subs
2562
2563Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2564when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2565so a null command knows what to re-execute.
69893cff
RGS
2566
2567=cut
2568
e22ea7cc 2569 # n - next
826b9a2e 2570 if ($cmd eq 'n') {
69893cff 2571 end_report(), next CMD if $finished and $level <= 1;
e22ea7cc 2572
69893cff
RGS
2573 # Single step, but don't enter subs.
2574 $single = 2;
e22ea7cc 2575
69893cff 2576 # Save for empty command (repeat last).
e22ea7cc
RF
2577 $laststep = $cmd;
2578 last CMD;
826b9a2e 2579 }
69893cff
RGS
2580
2581=head4 C<s> - single-step, entering subs
2582
826b9a2e 2583Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2584subs. Also saves C<s> as C<$lastcmd>.
2585
2586=cut
2587
2588 # s - single step.
826b9a2e 2589 if ($cmd eq 's') {
e22ea7cc 2590
69893cff
RGS
2591 # Get out and restart the command loop if program
2592 # has finished.
e22ea7cc
RF
2593 end_report(), next CMD if $finished and $level <= 1;
2594
69893cff 2595 # Single step should enter subs.
e22ea7cc
RF
2596 $single = 1;
2597
69893cff 2598 # Save for empty command (repeat last).
e22ea7cc
RF
2599 $laststep = $cmd;
2600 last CMD;
826b9a2e 2601 }
69893cff
RGS
2602
2603=head4 C<c> - run continuously, setting an optional breakpoint
2604
2605Most of the code for this command is taken up with locating the optional
2606breakpoint, which is either a subroutine name or a line number. We set
2607the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2608in this and all call levels above this one.
2609
2610=cut
2611
2612 # c - start continuous execution.
ef18ae63 2613 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2614
69893cff
RGS
2615 # Hey, show's over. The debugged program finished
2616 # executing already.
2617 end_report(), next CMD if $finished and $level <= 1;
2618
2619 # Capture the place to put a one-time break.
ef18ae63 2620 $subname = $i;
69893cff 2621
e22ea7cc
RF
2622 # Probably not needed, since we finish an interactive
2623 # sub-session anyway...
2624 # local $filename = $filename;
2625 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2626 #
2627 # The above question wonders if localizing the alias
2628 # to the magic array works or not. Since it's commented
2629 # out, we'll just leave that to speculation for now.
2630
2631 # If the "subname" isn't all digits, we'll assume it
2632 # is a subroutine name, and try to find it.
e22ea7cc
RF
2633 if ( $subname =~ /\D/ ) { # subroutine name
2634 # Qualify it to the current package unless it's
2635 # already qualified.
69893cff
RGS
2636 $subname = $package . "::" . $subname
2637 unless $subname =~ /::/;
e22ea7cc 2638
69893cff
RGS
2639 # find_sub will return "file:line_number" corresponding
2640 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2641 # break up the return value, and assign it in one
69893cff 2642 # operation.
e22ea7cc 2643 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2644
2645 # Force the line number to be numeric.
e22ea7cc 2646 $i += 0;
69893cff
RGS
2647
2648 # If we got a line number, we found the sub.
e22ea7cc
RF
2649 if ($i) {
2650
69893cff
RGS
2651 # Switch all the debugger's internals around so
2652 # we're actually working with that file.
e22ea7cc
RF
2653 $filename = $file;
2654 *dbline = $main::{ '_<' . $filename };
2655
69893cff 2656 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2657 $had_breakpoints{$filename} |= 1;
2658
69893cff
RGS
2659 # Scan forward to the first executable line
2660 # after the 'sub whatever' line.
e22ea7cc
RF
2661 $max = $#dbline;
2662 ++$i while $dbline[$i] == 0 && $i < $max;
2663 } ## end if ($i)
69893cff
RGS
2664
2665 # We didn't find a sub by that name.
e22ea7cc
RF
2666 else {
2667 print $OUT "Subroutine $subname not found.\n";
2668 next CMD;
2669 }
2670 } ## end if ($subname =~ /\D/)
69893cff
RGS
2671
2672 # At this point, either the subname was all digits (an
2673 # absolute line-break request) or we've scanned through
2674 # the code following the definition of the sub, looking
2675 # for an executable, which we may or may not have found.
2676 #
2677 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2678 # got a request to break at some line somewhere. On
2679 # one hand, if there wasn't any real subroutine name
2680 # involved, this will be a request to break in the current
2681 # file at the specified line, so we have to check to make
69893cff
RGS
2682 # sure that the line specified really is breakable.
2683 #
2684 # On the other hand, if there was a subname supplied, the
3c4b39be 2685 # preceding block has moved us to the proper file and
69893cff
RGS
2686 # location within that file, and then scanned forward
2687 # looking for the next executable line. We have to make
2688 # sure that one was found.
2689 #
2690 # On the gripping hand, we can't do anything unless the
2691 # current value of $i points to a valid breakable line.
2692 # Check that.
e22ea7cc
RF
2693 if ($i) {
2694
69893cff 2695 # Breakable?
e22ea7cc
RF
2696 if ( $dbline[$i] == 0 ) {
2697 print $OUT "Line $i not breakable.\n";
2698 next CMD;
2699 }
2700
69893cff 2701 # Yes. Set up the one-time-break sigil.
e22ea7cc 2702 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2703 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2704 } ## end if ($i)
69893cff
RGS
2705
2706 # Turn off stack tracing from here up.
2c247e84
SF
2707 for my $i (0 .. $stack_depth) {
2708 $stack[ $i ] &= ~1;
e22ea7cc
RF
2709 }
2710 last CMD;
ef18ae63 2711 }
69893cff
RGS
2712
2713=head4 C<r> - return from a subroutine
2714
2715For C<r> to work properly, the debugger has to stop execution again
2716immediately after the return is executed. This is done by forcing
2717single-stepping to be on in the call level above the current one. If
2718we are printing return values when a C<r> is executed, set C<$doret>
2719appropriately, and force us out of the command loop.
2720
2721=cut
2722
2723 # r - return from the current subroutine.
ef18ae63 2724 if ($cmd eq 'r') {
e22ea7cc 2725
98dc9551 2726 # Can't do anything if the program's over.
e22ea7cc
RF
2727 end_report(), next CMD if $finished and $level <= 1;
2728
69893cff 2729 # Turn on stack trace.
e22ea7cc
RF
2730 $stack[$stack_depth] |= 1;
2731
69893cff 2732 # Print return value unless the stack is empty.
e22ea7cc
RF
2733 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2734 last CMD;
ef18ae63 2735 }
69893cff 2736
69893cff
RGS
2737=head4 C<T> - stack trace
2738
2739Just calls C<DB::print_trace>.
2740
2741=cut
2742
ef18ae63 2743 if ($cmd eq 'T') {
e22ea7cc
RF
2744 print_trace( $OUT, 1 ); # skip DB
2745 next CMD;
ef18ae63 2746 }
69893cff
RGS
2747
2748=head4 C<w> - List window around current line.
2749
2750Just calls C<DB::cmd_w>.
2751
2752=cut
2753
ef18ae63
SF
2754 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2755 &cmd_w( 'w', $arg );
2756 next CMD;
2757 }
69893cff
RGS
2758
2759=head4 C<W> - watch-expression processing.
2760
b570d64b 2761Just calls C<DB::cmd_W>.
69893cff
RGS
2762
2763=cut
2764
ef18ae63
SF
2765 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2766 &cmd_W( 'W', $arg );
2767 next CMD;
2768 }
69893cff
RGS
2769
2770=head4 C</> - search forward for a string in the source
2771
ef18ae63 2772We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2773bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2774If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2775mess us up.
2776
2777=cut
2778
ef18ae63
SF
2779 # The pattern as a string.
2780 use vars qw($inpat);
69893cff 2781
ef18ae63 2782 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2783
2784 # Remove the final slash.
e22ea7cc 2785 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2786
2787 # If the pattern isn't null ...
e22ea7cc 2788 if ( $inpat ne "" ) {
69893cff
RGS
2789
2790 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2791 local $SIG{__DIE__};
2792 local $SIG{__WARN__};
69893cff
RGS
2793
2794 # Create the pattern.
e22ea7cc
RF
2795 eval '$inpat =~ m' . "\a$inpat\a";
2796 if ( $@ ne "" ) {
2797
69893cff 2798 # Oops. Bad pattern. No biscuit.
e22ea7cc 2799 # Print the eval error and go back for more
69893cff 2800 # commands.
e22ea7cc
RF
2801 print $OUT "$@";
2802 next CMD;
2803 }
2804 $pat = $inpat;
2805 } ## end if ($inpat ne "")
69893cff
RGS
2806
2807 # Set up to stop on wrap-around.
e22ea7cc 2808 $end = $start;
69893cff
RGS
2809
2810 # Don't move off the current line.
e22ea7cc 2811 $incr = -1;
69893cff
RGS
2812
2813 # Done in eval so nothing breaks if the pattern
2814 # does something weird.
e22ea7cc
RF
2815 eval '
2816 for (;;) {
69893cff 2817 # Move ahead one line.
e22ea7cc 2818 ++$start;
69893cff
RGS
2819
2820 # Wrap if we pass the last line.
e22ea7cc 2821 $start = 1 if ($start > $max);
69893cff
RGS
2822
2823 # Stop if we have gotten back to this line again,
e22ea7cc 2824 last if ($start == $end);
69893cff
RGS
2825
2826 # A hit! (Note, though, that we are doing
2827 # case-insensitive matching. Maybe a qr//
2828 # expression would be better, so the user could
2829 # do case-sensitive matching if desired.
e22ea7cc
RF
2830 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2831 if ($slave_editor) {
69893cff 2832 # Handle proper escaping in the slave.
e22ea7cc 2833 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2834 }
e22ea7cc 2835 else {
69893cff 2836 # Just print the line normally.
e22ea7cc
RF
2837 print $OUT "$start:\t",$dbline[$start],"\n";
2838 }
69893cff 2839 # And quit since we found something.
e22ea7cc
RF
2840 last;
2841 }
2842 } ';
2843
69893cff 2844 # If we wrapped, there never was a match.
e22ea7cc
RF
2845 print $OUT "/$pat/: not found\n" if ( $start == $end );
2846 next CMD;
ef18ae63 2847 }
69893cff
RGS
2848
2849=head4 C<?> - search backward for a string in the source
2850
2851Same as for C</>, except the loop runs backwards.
2852
2853=cut
2854
2855 # ? - backward pattern search.
ef18ae63 2856 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2857
2858 # Get the pattern, remove trailing question mark.
e22ea7cc 2859 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2860
2861 # If we've got one ...
e22ea7cc 2862 if ( $inpat ne "" ) {
69893cff
RGS
2863
2864 # Turn off die & warn handlers.
e22ea7cc
RF
2865 local $SIG{__DIE__};
2866 local $SIG{__WARN__};
2867 eval '$inpat =~ m' . "\a$inpat\a";
2868
2869 if ( $@ ne "" ) {
2870
69893cff 2871 # Ouch. Not good. Print the error.
e22ea7cc
RF
2872 print $OUT $@;
2873 next CMD;
2874 }
2875 $pat = $inpat;
69893cff 2876 } ## end if ($inpat ne "")
e22ea7cc 2877
69893cff 2878 # Where we are now is where to stop after wraparound.
e22ea7cc 2879 $end = $start;
69893cff
RGS
2880
2881 # Don't move away from this line.
e22ea7cc 2882 $incr = -1;
69893cff
RGS
2883
2884 # Search inside the eval to prevent pattern badness
2885 # from killing us.
e22ea7cc
RF
2886 eval '
2887 for (;;) {
69893cff 2888 # Back up a line.
e22ea7cc 2889 --$start;
69893cff
RGS
2890
2891 # Wrap if we pass the first line.
e22ea7cc
RF
2892
2893 $start = $max if ($start <= 0);
69893cff
RGS
2894
2895 # Quit if we get back where we started,
e22ea7cc 2896 last if ($start == $end);
69893cff
RGS
2897
2898 # Match?
e22ea7cc
RF
2899 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2900 if ($slave_editor) {
69893cff 2901 # Yep, follow slave editor requirements.
e22ea7cc 2902 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2903 }
e22ea7cc 2904 else {
69893cff 2905 # Yep, just print normally.
e22ea7cc
RF
2906 print $OUT "$start:\t",$dbline[$start],"\n";
2907 }
69893cff
RGS
2908
2909 # Found, so done.
e22ea7cc
RF
2910 last;
2911 }
2912 } ';
2913
2914 # Say we failed if the loop never found anything,
2915 print $OUT "?$pat?: not found\n" if ( $start == $end );
2916 next CMD;
ef18ae63 2917 }
69893cff
RGS
2918
2919=head4 C<$rc> - Recall command
2920
2921Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2922that the terminal supports history). It find the the command required, puts it
2923into C<$cmd>, and redoes the loop to execute it.
2924
2925=cut
2926
e22ea7cc 2927 # $rc - recall command.
ef18ae63 2928 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2929
2930 # No arguments, take one thing off history.
e22ea7cc 2931 pop(@hist) if length($cmd) > 1;
69893cff 2932
e22ea7cc 2933 # Relative (- found)?
69893cff 2934 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2935 # N - go to that particular command slot or the last
69893cff 2936 # thing if nothing following.
ef18ae63 2937 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2938
2939 # Pick out the command desired.
e22ea7cc 2940 $cmd = $hist[$i];
69893cff
RGS
2941
2942 # Print the command to be executed and restart the loop
2943 # with that command in the buffer.
e22ea7cc
RF
2944 print $OUT $cmd, "\n";
2945 redo CMD;
ef18ae63 2946 }
69893cff
RGS
2947
2948=head4 C<$sh$sh> - C<system()> command
2949
2950Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2951C<STDOUT> from getting messed up.
2952
2953=cut
2954
2955 # $sh$sh - run a shell command (if it's all ASCII).
2956 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2957 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2958
69893cff 2959 # System it.
ef18ae63 2960 &system($arg);
e22ea7cc 2961 next CMD;
ef18ae63 2962 }
69893cff
RGS
2963
2964=head4 C<$rc I<pattern> $rc> - Search command history
2965
2966Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2967If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2968
2969=cut
2970
e22ea7cc 2971 # $rc pattern $rc - find a command in the history.
ef18ae63 2972 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2973
69893cff 2974 # Create the pattern to use.
ef18ae63 2975 $pat = "^$arg";
69893cff
RGS
2976
2977 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2978 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2979
2980 # Look backward through the history.
72d7d80d 2981 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2982 # Stop if we find it.
e22ea7cc
RF
2983 last if $hist[$i] =~ /$pat/;
2984 }
2985
2986 if ( !$i ) {
69893cff 2987
69893cff 2988 # Never found it.
e22ea7cc
RF
2989 print $OUT "No such command!\n\n";
2990 next CMD;
2991 }
69893cff
RGS
2992
2993 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2994 $cmd = $hist[$i];
2995 print $OUT $cmd, "\n";
2996 redo CMD;
ef18ae63 2997 }
69893cff 2998
ef18ae63 2999=head4 C<$sh> - Invoke a shell
69893cff
RGS
3000
3001Uses C<DB::system> to invoke a shell.
3002
3003=cut
3004
3005 # $sh - start a shell.
ef18ae63 3006 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 3007
69893cff
RGS
3008 # Run the user's shell. If none defined, run Bourne.
3009 # We resume execution when the shell terminates.
e22ea7cc
RF
3010 &system( $ENV{SHELL} || "/bin/sh" );
3011 next CMD;
ef18ae63 3012 }
69893cff
RGS
3013
3014=head4 C<$sh I<command>> - Force execution of a command in a shell
3015
3016Like the above, but the command is passed to the shell. Again, we use
3017C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
3018
3019=cut
3020
3021 # $sh command - start a shell and run a command in it.
ef18ae63 3022 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
3023
3024 # XXX: using csh or tcsh destroys sigint retvals!
3025 #&system($1); # use this instead
69893cff
RGS
3026
3027 # use the user's shell, or Bourne if none defined.
ef18ae63 3028 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 3029 next CMD;
ef18ae63 3030 }
69893cff
RGS
3031
3032=head4 C<H> - display commands in history
3033
3034Prints the contents of C<@hist> (if any).
3035
3036=cut
3037
ef18ae63 3038 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
3039 @hist = @truehist = ();
3040 print $OUT "History cleansed\n";
3041 next CMD;
ef18ae63 3042 }
e22ea7cc 3043
ef18ae63
SF
3044 if (my ($num)
3045 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
3046
3047 # Anything other than negative numbers is ignored by
69893cff 3048 # the (incorrect) pattern, so this test does nothing.
ef18ae63 3049 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
3050
3051 # Set to the minimum if less than zero.
e22ea7cc 3052 $hist = 0 if $hist < 0;
69893cff 3053
e22ea7cc 3054 # Start at the end of the array.
69893cff
RGS
3055 # Stay in while we're still above the ending value.
3056 # Tick back by one each time around the loop.
72d7d80d 3057 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
3058
3059 # Print the command unless it has no arguments.
e22ea7cc
RF
3060 print $OUT "$i: ", $hist[$i], "\n"
3061 unless $hist[$i] =~ /^.?$/;
3062 }
3063 next CMD;
ef18ae63 3064 }
69893cff
RGS
3065
3066=head4 C<man, doc, perldoc> - look up documentation
3067
3068Just calls C<runman()> to print the appropriate document.
3069
3070=cut
3071
e22ea7cc 3072 # man, perldoc, doc - show manual pages.
ef18ae63
SF
3073 if (my ($man_page)
3074 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3075 runman($man_page);
e22ea7cc 3076 next CMD;
ef18ae63 3077 }
69893cff
RGS
3078
3079=head4 C<p> - print
3080
3081Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
3082the bottom of the loop.
3083
3084=cut
3085
ef18ae63 3086 my $print_cmd = 'print {$DB::OUT} ';
69893cff 3087 # p - print (no args): print $_.
ef18ae63
SF
3088 if ($cmd eq 'p') {
3089 $cmd = $print_cmd . '$_';
3090 }
69893cff
RGS
3091
3092 # p - print the given expression.
ef18ae63 3093 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
3094
3095=head4 C<=> - define command alias
3096
3097Manipulates C<%alias> to add or list command aliases.
3098
3099=cut
3100
e22ea7cc 3101 # = - set up a command alias.
ef18ae63 3102 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
3103 my @keys;
3104 if ( length $cmd == 0 ) {
3105
69893cff 3106 # No args, get current aliases.
e22ea7cc
RF
3107 @keys = sort keys %alias;
3108 }
3109 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3110
69893cff
RGS
3111 # Creating a new alias. $k is alias name, $v is
3112 # alias value.
3113
e22ea7cc
RF
3114 # can't use $_ or kill //g state
3115 for my $x ( $k, $v ) {
3116
3117 # Escape "alarm" characters.
3118 $x =~ s/\a/\\a/g;
3119 }
69893cff
RGS
3120
3121 # Substitute key for value, using alarm chars
e22ea7cc 3122 # as separators (which is why we escaped them in
69893cff 3123 # the command).
e22ea7cc 3124 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3125
3126 # Turn off standard warn and die behavior.
e22ea7cc
RF
3127 local $SIG{__DIE__};
3128 local $SIG{__WARN__};
69893cff
RGS
3129
3130 # Is it valid Perl?
e22ea7cc
RF
3131 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3132
69893cff 3133 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3134 print $OUT "Can't alias $k to $v: $@\n";
3135 delete $alias{$k};
3136 next CMD;
3137 }
3138
69893cff 3139 # We'll only list the new one.
e22ea7cc 3140 @keys = ($k);
69893cff
RGS
3141 } ## end elsif (my ($k, $v) = ($cmd...
3142
3143 # The argument is the alias to list.
e22ea7cc
RF
3144 else {
3145 @keys = ($cmd);
3146 }
69893cff
RGS
3147
3148 # List aliases.
e22ea7cc
RF
3149 for my $k (@keys) {
3150
98dc9551 3151 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
3152 # We use control-G as the delimiter because it's not
3153 # likely to appear in the alias.
e22ea7cc
RF
3154 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3155
69893cff 3156 # Print the alias.
e22ea7cc
RF
3157 print $OUT "$k\t= $1\n";
3158 }
3159 elsif ( defined $alias{$k} ) {
3160
69893cff 3161 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3162 print $OUT "$k\t$alias{$k}\n";
3163 }
3164 else {
3165
69893cff 3166 # No such, dude.
e22ea7cc
RF
3167 print "No alias for $k\n";
3168 }
69893cff 3169 } ## end for my $k (@keys)
e22ea7cc 3170 next CMD;
ef18ae63 3171 }
69893cff
RGS
3172
3173=head4 C<source> - read commands from a file.
3174
3175Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3176pick it up.
3177
3178=cut
3179
e22ea7cc 3180 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3181 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3182 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3183
69893cff 3184 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3185 push @cmdfhs, $fh;
3186 }
3187 else {
3188
3189 # Couldn't open it.
ef18ae63 3190 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3191 }
3192 next CMD;
ef18ae63 3193 }
69893cff 3194
ef18ae63
SF
3195 if (my ($which_cmd, $position)
3196 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3197
3198 my ($fn, $line_num);
3199 if ($position =~ m{\A\d+\z})
3200 {
3201 $fn = $filename;
3202 $line_num = $position;
3203 }
ef18ae63
SF
3204 elsif (my ($new_fn, $new_line_num)
3205 = $position =~ m{\A(.*):(\d+)\z}) {
3206 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3207 }
3208 else
3209 {
3210 &warn("Wrong spec for enable/disable argument.\n");
3211 }
3212
3213 if (defined($fn)) {
3214 if (_has_breakpoint_data_ref($fn, $line_num)) {
3215 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3216 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3217 );
3218 }
3219 else {
3220 &warn("No breakpoint set at ${fn}:${line_num}\n");
3221 }
3222 }
3223
3224 next CMD;
ef18ae63 3225 }
e09195af 3226
69893cff
RGS
3227=head4 C<save> - send current history to a file
3228
3229Takes the complete history, (not the shrunken version you see with C<H>),
3230and saves it to the given filename, so it can be replayed using C<source>.
3231
3232Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3233
3234=cut
3235
3236 # save source - write commands to a file for later use
ef18ae63
SF
3237 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3238 my $filename = $new_fn || '.perl5dbrc'; # default?
3239 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3240
3241 # chomp to remove extraneous newlines from source'd files
3242 chomp( my @truelist =
3243 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3244 @truehist );
3245 print $fh join( "\n", @truelist );
69893cff 3246 print "commands saved in $file\n";
e22ea7cc
RF
3247 }
3248 else {
ef18ae63 3249 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3250 }
3251 next CMD;
ef18ae63 3252 }
69893cff 3253
7fddc82f
RF
3254=head4 C<R> - restart
3255
ef18ae63 3256Restart the debugger session.
7fddc82f
RF
3257
3258=head4 C<rerun> - rerun the current session
3259
3260Return to any given position in the B<true>-history list
3261
3262=cut
3263
3264 # R - restart execution.
3265 # rerun - controlled restart execution.
ff41e38d
SF
3266 if (my ($cmd_cmd, $cmd_params) =
3267 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3268 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3269
ca28b541
AP
3270 # Close all non-system fds for a clean restart. A more
3271 # correct method would be to close all fds that were not
3272 # open when the process started, but this seems to be
3273 # hard. See "debugger 'R'estart and open database
3274 # connections" on p5p.
3275
47d3bbda 3276 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3277 if (eval { require POSIX }) {
5332cc68 3278 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3279 }
3280
3281 if (defined $max_fd) {
3282 foreach ($^F+1 .. $max_fd-1) {
3283 next unless open FD_TO_CLOSE, "<&=$_";
3284 close(FD_TO_CLOSE);
3285 }
3286 }
3287
7fddc82f
RF
3288 # And run Perl again. We use exec() to keep the
3289 # PID stable (and that way $ini_pids is still valid).
3290 exec(@args) || print $OUT "exec failed: $!\n";
3291
3292 last CMD;
ff41e38d 3293 }
7fddc82f 3294
69893cff
RGS
3295=head4 C<|, ||> - pipe output through the pager.
3296
be9a9b1d 3297For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3298(the program's standard output). For C<||>, we only save C<OUT>. We open a
3299pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3300is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3301set C<$signal>, sending us back into the debugger.
3302
3303We then trim off the pipe symbols and C<redo> the command loop at the
3304C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3305reading another.
3306
3307=cut
3308
3309 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3310 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3311 if ( $pager =~ /^\|/ ) {
3312
69893cff 3313 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3314 open( SAVEOUT, ">&STDOUT" )
3315 || &warn("Can't save STDOUT");
3316 open( STDOUT, ">&OUT" )
3317 || &warn("Can't redirect STDOUT");
69893cff 3318 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3319 else {
3320
69893cff 3321 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3322 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3323 }
69893cff
RGS
3324
3325 # Fix up environment to record we have less if so.
e22ea7cc
RF
3326 fix_less();
3327
3328 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3329
69893cff 3330 # Couldn't open pipe to pager.
1f874cb6 3331 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3332 if ( $pager =~ /^\|/ ) {
3333
69893cff 3334 # Redirect I/O back again.
e22ea7cc
RF
3335 open( OUT, ">&STDOUT" ) # XXX: lost message
3336 || &warn("Can't restore DB::OUT");
3337 open( STDOUT, ">&SAVEOUT" )
3338 || &warn("Can't restore STDOUT");
3339 close(SAVEOUT);
69893cff 3340 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3341 else {
3342
69893cff 3343 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3344 open( OUT, ">&STDOUT" ) # XXX: lost message
3345 || &warn("Can't restore DB::OUT");
3346 }
3347 next CMD;
69893cff
RGS
3348 } ## end unless ($piped = open(OUT,...
3349
3350 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3351 $SIG{PIPE} = \&DB::catch
3352 if $pager =~ /^\|/
3353 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3354
70c9432b
SF
3355 OUT->autoflush(1);
3356 # Save current filehandle, and put it back.
e22ea7cc 3357 $selected = select(OUT);
69893cff 3358 # Don't put it back if pager was a pipe.
e22ea7cc 3359 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3360
3361 # Trim off the pipe symbols and run the command now.
ff41e38d 3362 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3363 redo PIPE;
ff41e38d 3364 }
69893cff
RGS
3365
3366=head3 END OF COMMAND PARSING
3367
ff41e38d
SF
3368Anything left in C<$cmd> at this point is a Perl expression that we want to
3369evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3370any variables we might want to address in the C<DB> package.
3371
3372=cut
3373
3374 # t - turn trace on.
ff41e38d
SF
3375 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3376 my $trace_arg = $1;
3377 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3378 }
69893cff
RGS
3379
3380 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3381 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3382 $laststep = 's';
3383 }
69893cff
RGS
3384
3385 # n - single-step, but not into subs. Remember last command
e22ea7cc 3386 # was 'n'.
ff41e38d
SF
3387 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3388 $laststep = 'n';
3389 }
69893cff 3390
e22ea7cc 3391 } # PIPE:
69893cff 3392
e22ea7cc 3393 # Make sure the flag that says "the debugger's running" is
69893cff 3394 # still on, to make sure we get control again.
e22ea7cc 3395 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3396
3397 # Run *our* eval that executes in the caller's context.
e22ea7cc 3398 &eval;
69893cff
RGS
3399
3400 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3401 if ($onetimeDump) {
3402 $onetimeDump = undef;
69893cff 3403 $onetimedumpDepth = undef;
e22ea7cc
RF
3404 }
3405 elsif ( $term_pid == $$ ) {
c7e68384
IZ
3406 eval { # May run under miniperl, when not available...
3407 STDOUT->flush();
3408 STDERR->flush();
3409 };
e22ea7cc 3410
69893cff 3411 # XXX If this is the master pid, print a newline.
e22ea7cc
RF
3412 print $OUT "\n";
3413 }
3414 } ## end while (($term || &setterm...
69893cff
RGS
3415
3416=head3 POST-COMMAND PROCESSING
3417
3418After each command, we check to see if the command output was piped anywhere.
3419If so, we go through the necessary code to unhook the pipe and go back to
3420our standard filehandles for input and output.
3421
3422=cut
3423
e22ea7cc 3424 continue { # CMD:
69893cff
RGS
3425
3426 # At the end of every command:
e22ea7cc
RF
3427 if ($piped) {
3428
69893cff 3429 # Unhook the pipe mechanism now.
e22ea7cc
RF
3430 if ( $pager =~ /^\|/ ) {
3431
69893cff 3432 # No error from the child.
e22ea7cc 3433 $? = 0;
69893cff 3434
e22ea7cc
RF
3435 # we cannot warn here: the handle is missing --tchrist
3436 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3437
e22ea7cc 3438 # most of the $? crud was coping with broken cshisms
69893cff 3439 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3440 if ($?) {
1f874cb6 3441 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3442 if ( $? == -1 ) {
3443 print SAVEOUT "shell returned -1\n";
3444 }
3445 elsif ( $? >> 8 ) {
3446 print SAVEOUT ( $? & 127 )
3447 ? " (SIG#" . ( $? & 127 ) . ")"
3448 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3449 }
3450 else {
3451 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3452 }
69893cff
RGS
3453 } ## end if ($?)
3454
e22ea7cc 3455 # Reopen filehandle for our output (if we can) and
69893cff 3456 # restore STDOUT (if we can).
e22ea7cc
RF
3457 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3458 open( STDOUT, ">&SAVEOUT" )
3459 || &warn("Can't restore STDOUT");
69893cff
RGS
3460
3461 # Turn off pipe exception handler if necessary.
e22ea7cc 3462 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3463
e22ea7cc
RF
3464 # Will stop ignoring SIGPIPE if done like nohup(1)
3465 # does SIGINT but Perl doesn't give us a choice.
69893cff 3466 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3467 else {
3468
69893cff 3469 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3470 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3471 }
69893cff
RGS
3472
3473 # Close filehandle pager was using, restore the normal one
3474 # if necessary,
3475 close(SAVEOUT);
e22ea7cc 3476 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3477
3478 # No pipes now.
e22ea7cc 3479 $piped = "";
69893cff 3480 } ## end if ($piped)
e22ea7cc 3481 } # CMD:
69893cff
RGS
3482
3483=head3 COMMAND LOOP TERMINATION
3484
3485When commands have finished executing, we come here. If the user closed the
3486input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3487evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3488C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3489The interpreter will then execute the next line and then return control to us
3490again.
3491
3492=cut
3493
3494 # No more commands? Quit.
1f874cb6 3495 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3496
3497 # Evaluate post-prompt commands.
e22ea7cc
RF
3498 foreach $evalarg (@$post) {
3499 &eval;
3500 }
3501 } # if ($single || $signal)
69893cff
RGS
3502
3503 # Put the user's globals back where you found them.
e22ea7cc 3504 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3505 ();
3506} ## end sub DB
3507
3508# The following code may be executed now:
3509# BEGIN {warn 4}
3510
3511=head2 sub
3512
b570d64b 3513C<sub> is called whenever a subroutine call happens in the program being
69893cff
RGS
3514debugged. The variable C<$DB::sub> contains the name of the subroutine
3515being called.
3516
3517The core function of this subroutine is to actually call the sub in the proper
3518context, capturing its output. This of course causes C<DB::DB> to get called
3519again, repeating until the subroutine ends and returns control to C<DB::sub>
3520again. Once control returns, C<DB::sub> figures out whether or not to dump the
3521return value, and returns its captured copy of the return value as its own
3522return value. The value then feeds back into the program being debugged as if
3523C<DB::sub> hadn't been there at all.
3524
3525C<sub> does all the work of printing the subroutine entry and exit messages
3526enabled by setting C<$frame>. It notes what sub the autoloader got called for,
b570d64b 3527and also prints the return value if needed (for the C<r> command and if
69893cff
RGS
3528the 16 bit is set in C<$frame>).
3529
3530It also tracks the subroutine call depth by saving the current setting of
3531C<$single> in the C<@stack> package global; if this exceeds the value in
3532C<$deep>, C<sub> automatically turns on printing of the current depth by
be9a9b1d 3533setting the C<4> bit in C<$single>. In any case, it keeps the current setting
69893cff
RGS
3534of stop/don't stop on entry to subs set as it currently is set.
3535
3536=head3 C<caller()> support
3537
3538If C<caller()> is called from the package C<DB>, it provides some
3539additional data, in the following order:
3540
3541=over 4
3542
3543=item * C<$package>
3544
3545The package name the sub was in
3546
3547=item * C<$filename>
3548
3549The filename it was defined in
3550