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[perl5db] Convert more global vars to our.
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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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5
6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
69893cff 136
be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
ef18ae63 189The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
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190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
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193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
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200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
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204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
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214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
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218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
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227ReadLine applications.
228
b570d64b 229=item * NonStop
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230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
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234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
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239
240host:port to connect to on remote host for remote debugging.
241
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242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
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252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
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262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
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269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
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285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
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308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
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314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
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318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
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331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
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333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
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354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
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368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
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375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
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377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
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383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
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406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
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446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
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454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 476=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
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477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
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486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
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490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
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494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
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504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
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511package DB;
512
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513use strict;
514
2dbd01ad 515BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 516
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517BEGIN {
518 require feature;
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
521}
522
54d04a52 523# Debugger for Perl 5.00x; perl5db.pl patch level:
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524use vars qw($VERSION $header);
525
931d9438 526$VERSION = '1.39_05';
69893cff 527
e22ea7cc 528$header = "perl5db.pl version $VERSION";
d338d6fe 529
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530=head1 DEBUGGER ROUTINES
531
532=head2 C<DB::eval()>
533
534This function replaces straight C<eval()> inside the debugger; it simplifies
535the process of evaluating code in the user's context.
536
b570d64b 537The code to be evaluated is passed via the package global variable
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538C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
539
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540Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543user's current package, grabbed when C<DB::DB> got control. This causes the
544proper context to be used when the eval is actually done. Afterward, we
545restore C<$trace>, C<$single>, and C<$^D>.
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546
547Next we need to handle C<$@> without getting confused. We save C<$@> in a
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548local lexical, localize C<$saved[0]> (which is where C<save()> will put
549C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 550C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
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551considered sane by the debugger. If there was an C<eval()> error, we print
552it on the debugger's output. If C<$onetimedump> is defined, we call
553C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554'methods'. Setting it to something else causes the debugger to do the eval
555but not print the result - handy if you want to do something else with it
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556(the "watch expressions" code does this to get the value of the watch
557expression but not show it unless it matters).
558
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559In any case, we then return the list of output from C<eval> to the caller,
560and unwinding restores the former version of C<$@> in C<@saved> as well
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561(the localization of C<$saved[0]> goes away at the end of this scope).
562
563=head3 Parameters and variables influencing execution of DB::eval()
564
565C<DB::eval> isn't parameterized in the standard way; this is to keep the
566debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 567The variables listed below influence C<DB::eval()>'s execution directly.
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568
569=over 4
570
571=item C<$evalarg> - the thing to actually be eval'ed
572
be9a9b1d 573=item C<$trace> - Current state of execution tracing
69893cff 574
be9a9b1d 575=item C<$single> - Current state of single-stepping
69893cff 576
b570d64b 577=item C<$onetimeDump> - what is to be displayed after the evaluation
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578
579=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
580
581=back
582
583The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 584are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
585
586=over 4
587
588=item C<@res> - used to capture output from actual C<eval>.
589
590=item C<$otrace> - saved value of C<$trace>.
591
b570d64b 592=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
593
594=item C<$od> - saved value of C<$^D>.
595
596=item C<$saved[0]> - saved value of C<$@>.
597
b570d64b 598=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
599
600=back
601
602=head3 The problem of lexicals
603
604The context of C<DB::eval()> presents us with some problems. Obviously,
605we want to be 'sandboxed' away from the debugger's internals when we do
606the eval, but we need some way to control how punctuation variables and
b570d64b 607debugger globals are used.
69893cff
RGS
608
609We can't use local, because the code inside C<DB::eval> can see localized
610variables; and we can't use C<my> either for the same reason. The code
611in this routine compromises and uses C<my>.
612
613After this routine is over, we don't have user code executing in the debugger's
614context, so we can use C<my> freely.
615
616=cut
617
618############################################## Begin lexical danger zone
619
620# 'my' variables used here could leak into (that is, be visible in)
621# the context that the code being evaluated is executing in. This means that
622# the code could modify the debugger's variables.
623#
624# Fiddling with the debugger's context could be Bad. We insulate things as
625# much as we can.
626
6b24a4b7
SF
627use vars qw(
628 @args
629 %break_on_load
630 @cmdfhs
631 $CommandSet
632 $CreateTTY
633 $DBGR
634 @dbline
635 $dbline
636 %dbline
637 $dieLevel
6b24a4b7
SF
638 $filename
639 $frame
640 $hist
641 $histfile
642 $histsize
6b24a4b7
SF
643 $IN
644 $inhibit_exit
645 @ini_INC
646 $ini_warn
647 $line
648 $maxtrace
649 $od
6b24a4b7
SF
650 $onetimedumpDepth
651 %option
652 @options
653 $osingle
654 $otrace
6b24a4b7
SF
655 $packname
656 $pager
657 $post
658 %postponed
659 $prc
660 $pre
661 $pretype
662 $psh
663 @RememberOnROptions
664 $remoteport
665 @res
666 $rl
667 @saved
6b24a4b7 668 $signalLevel
6b24a4b7
SF
669 $start
670 $sub
671 %sub
672 $subname
673 $term
6b24a4b7
SF
674 $usercontext
675 $warnLevel
676 $window
677);
678
8ad70697 679our ($trace, $single, $signal, $ImmediateStop, $evalarg, $onetimeDump, $OUT, );
931ac036 680
6b24a4b7
SF
681# Used to save @ARGV and extract any debugger-related flags.
682use vars qw(@ARGS);
683
684# Used to prevent multiple entries to diesignal()
685# (if for instance diesignal() itself dies)
686use vars qw($panic);
687
688# Used to prevent the debugger from running nonstop
689# after a restart
ebd0282e 690our ($second_time);
6b24a4b7
SF
691
692sub _calc_usercontext {
693 my ($package) = @_;
694
695 # Cancel strict completely for the evaluated code, so the code
696 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 697 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
698 . "package $package;"; # this won't let them modify, alas
699}
700
c1051fcf 701sub eval {
69893cff 702
c1051fcf 703 # 'my' would make it visible from user code
e22ea7cc 704 # but so does local! --tchrist
69893cff 705 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
706 local @res;
707 {
e22ea7cc
RF
708
709 # Try to keep the user code from messing with us. Save these so that
710 # even if the eval'ed code changes them, we can put them back again.
711 # Needed because the user could refer directly to the debugger's
69893cff
RGS
712 # package globals (and any 'my' variables in this containing scope)
713 # inside the eval(), and we want to try to stay safe.
e22ea7cc 714 local $otrace = $trace;
69893cff
RGS
715 local $osingle = $single;
716 local $od = $^D;
717
718 # Untaint the incoming eval() argument.
719 { ($evalarg) = $evalarg =~ /(.*)/s; }
720
e22ea7cc 721 # $usercontext built in DB::DB near the comment
69893cff
RGS
722 # "set up the context for DB::eval ..."
723 # Evaluate and save any results.
e22ea7cc 724 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
725
726 # Restore those old values.
727 $trace = $otrace;
728 $single = $osingle;
729 $^D = $od;
c1051fcf 730 }
69893cff
RGS
731
732 # Save the current value of $@, and preserve it in the debugger's copy
733 # of the saved precious globals.
c1051fcf 734 my $at = $@;
69893cff
RGS
735
736 # Since we're only saving $@, we only have to localize the array element
737 # that it will be stored in.
e22ea7cc 738 local $saved[0]; # Preserve the old value of $@
7c54f46a 739 eval { DB::save() };
69893cff
RGS
740
741 # Now see whether we need to report an error back to the user.
c1051fcf 742 if ($at) {
69893cff
RGS
743 local $\ = '';
744 print $OUT $at;
745 }
746
747 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
748 # are package globals.
749 elsif ($onetimeDump) {
e22ea7cc
RF
750 if ( $onetimeDump eq 'dump' ) {
751 local $option{dumpDepth} = $onetimedumpDepth
752 if defined $onetimedumpDepth;
753 dumpit( $OUT, \@res );
754 }
755 elsif ( $onetimeDump eq 'methods' ) {
756 methods( $res[0] );
757 }
69893cff 758 } ## end elsif ($onetimeDump)
c1051fcf 759 @res;
69893cff
RGS
760} ## end sub eval
761
762############################################## End lexical danger zone
c1051fcf 763
e22ea7cc
RF
764# After this point it is safe to introduce lexicals.
765# The code being debugged will be executing in its own context, and
69893cff 766# can't see the inside of the debugger.
d338d6fe 767#
e22ea7cc 768# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
769# possible. If you make something a lexical, it's not going to be addressable
770# from outside the debugger even if you know its name.
771
d338d6fe
PP
772# This file is automatically included if you do perl -d.
773# It's probably not useful to include this yourself.
774#
e22ea7cc 775# Before venturing further into these twisty passages, it is
2f7e9187
MS
776# wise to read the perldebguts man page or risk the ire of dragons.
777#
69893cff
RGS
778# (It should be noted that perldebguts will tell you a lot about
779# the underlying mechanics of how the debugger interfaces into the
780# Perl interpreter, but not a lot about the debugger itself. The new
781# comments in this code try to address this problem.)
782
d338d6fe 783# Note that no subroutine call is possible until &DB::sub is defined
36477c24 784# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 785# true if $deep is not defined.
055fd3a9
GS
786
787# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
788
789# modified Perl debugger, to be run from Emacs in perldb-mode
790# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
791# Johan Vromans -- upgrade to 4.0 pl 10
792# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 793########################################################################
d338d6fe 794
69893cff
RGS
795=head1 DEBUGGER INITIALIZATION
796
797The debugger starts up in phases.
798
799=head2 BASIC SETUP
800
801First, it initializes the environment it wants to run in: turning off
802warnings during its own compilation, defining variables which it will need
803to avoid warnings later, setting itself up to not exit when the program
804terminates, and defaulting to printing return values for the C<r> command.
805
806=cut
807
eda6e075 808# Needed for the statement after exec():
69893cff
RGS
809#
810# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 811# compilation. Probably it would be better practice to fix the warnings,
69893cff 812# but this is how it's done at the moment.
eda6e075 813
e22ea7cc
RF
814BEGIN {
815 $ini_warn = $^W;
816 $^W = 0;
817} # Switch compilation warnings off until another BEGIN.
d12a4851 818
69893cff
RGS
819local ($^W) = 0; # Switch run-time warnings off during init.
820
2cbb2ee1
RGS
821=head2 THREADS SUPPORT
822
823If we are running under a threaded Perl, we require threads and threads::shared
824if the environment variable C<PERL5DB_THREADED> is set, to enable proper
825threaded debugger control. C<-dt> can also be used to set this.
826
827Each new thread will be announced and the debugger prompt will always inform
828you of each new thread created. It will also indicate the thread id in which
829we are currently running within the prompt like this:
830
2dbd01ad 831 [tid] DB<$i>
2cbb2ee1
RGS
832
833Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
834command prompt. The prompt will show: C<[0]> when running under threads, but
835not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
836
837While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 838will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
839in a currently executing thread, you will stay there until it completes. With
840the current implementation it is not currently possible to hop from one thread
841to another.
842
843The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
844
845Note that threading support was built into the debugger as of Perl version
846C<5.8.6> and debugger version C<1.2.8>.
847
848=cut
849
850BEGIN {
2dbd01ad
SF
851 # ensure we can share our non-threaded variables or no-op
852 if ($ENV{PERL5DB_THREADED}) {
853 require threads;
854 require threads::shared;
855 import threads::shared qw(share);
856 $DBGR;
857 share(\$DBGR);
858 lock($DBGR);
859 print "Threads support enabled\n";
860 } else {
861 *lock = sub(*) {};
862 *share = sub(*) {};
863 }
2cbb2ee1
RGS
864}
865
2218c045
SF
866# These variables control the execution of 'dumpvar.pl'.
867{
868 package dumpvar;
869 use vars qw(
870 $hashDepth
871 $arrayDepth
872 $dumpDBFiles
873 $dumpPackages
874 $quoteHighBit
875 $printUndef
876 $globPrint
877 $usageOnly
878 );
879}
69893cff 880
2218c045
SF
881# used to control die() reporting in diesignal()
882{
883 package Carp;
884 use vars qw($CarpLevel);
885}
d338d6fe 886
422c59bf 887# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 888foreach my $k (keys (%INC)) {
2dbd01ad 889 share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
890};
891
54d04a52 892# Command-line + PERLLIB:
69893cff 893# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
894@ini_INC = @INC;
895
69893cff
RGS
896# This was an attempt to clear out the previous values of various
897# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
898# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
899
69893cff
RGS
900# We set these variables to safe values. We don't want to blindly turn
901# off warnings, because other packages may still want them.
e22ea7cc
RF
902$trace = $signal = $single = 0; # Uninitialized warning suppression
903 # (local $^W cannot help - other packages!).
69893cff
RGS
904
905# Default to not exiting when program finishes; print the return
906# value when the 'r' command is used to return from a subroutine.
55497cff 907$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 908
6b24a4b7
SF
909use vars qw($trace_to_depth);
910
5e2b42dd
SF
911# Default to 1E9 so it won't be limited to a certain recursion depth.
912$trace_to_depth = 1E9;
bdba49ad 913
69893cff
RGS
914=head1 OPTION PROCESSING
915
b570d64b
SF
916The debugger's options are actually spread out over the debugger itself and
917C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
918subs to be called with a value. To try to make this a little easier to
919manage, the debugger uses a few data structures to define what options
920are legal and how they are to be processed.
921
922First, the C<@options> array defines the I<names> of all the options that
923are to be accepted.
924
925=cut
926
927@options = qw(
5561b870 928 CommandSet HistFile HistSize
e22ea7cc
RF
929 hashDepth arrayDepth dumpDepth
930 DumpDBFiles DumpPackages DumpReused
931 compactDump veryCompact quote
932 HighBit undefPrint globPrint
933 PrintRet UsageOnly frame
934 AutoTrace TTY noTTY
935 ReadLine NonStop LineInfo
936 maxTraceLen recallCommand ShellBang
937 pager tkRunning ornaments
938 signalLevel warnLevel dieLevel
939 inhibit_exit ImmediateStop bareStringify
940 CreateTTY RemotePort windowSize
584420f0 941 DollarCaretP
e22ea7cc 942);
d12a4851 943
584420f0 944@RememberOnROptions = qw(DollarCaretP);
d12a4851 945
69893cff
RGS
946=pod
947
948Second, C<optionVars> lists the variables that each option uses to save its
949state.
950
951=cut
952
6b24a4b7
SF
953use vars qw(%optionVars);
954
69893cff 955%optionVars = (
e22ea7cc
RF
956 hashDepth => \$dumpvar::hashDepth,
957 arrayDepth => \$dumpvar::arrayDepth,
958 CommandSet => \$CommandSet,
959 DumpDBFiles => \$dumpvar::dumpDBFiles,
960 DumpPackages => \$dumpvar::dumpPackages,
961 DumpReused => \$dumpvar::dumpReused,
962 HighBit => \$dumpvar::quoteHighBit,
963 undefPrint => \$dumpvar::printUndef,
964 globPrint => \$dumpvar::globPrint,
965 UsageOnly => \$dumpvar::usageOnly,
966 CreateTTY => \$CreateTTY,
967 bareStringify => \$dumpvar::bareStringify,
968 frame => \$frame,
969 AutoTrace => \$trace,
970 inhibit_exit => \$inhibit_exit,
971 maxTraceLen => \$maxtrace,
972 ImmediateStop => \$ImmediateStop,
973 RemotePort => \$remoteport,
974 windowSize => \$window,
5561b870
AK
975 HistFile => \$histfile,
976 HistSize => \$histsize,
69893cff
RGS
977);
978
979=pod
980
981Third, C<%optionAction> defines the subroutine to be called to process each
982option.
983
b570d64b 984=cut
69893cff 985
6b24a4b7
SF
986use vars qw(%optionAction);
987
69893cff
RGS
988%optionAction = (
989 compactDump => \&dumpvar::compactDump,
990 veryCompact => \&dumpvar::veryCompact,
991 quote => \&dumpvar::quote,
992 TTY => \&TTY,
993 noTTY => \&noTTY,
994 ReadLine => \&ReadLine,
995 NonStop => \&NonStop,
996 LineInfo => \&LineInfo,
997 recallCommand => \&recallCommand,
998 ShellBang => \&shellBang,
999 pager => \&pager,
1000 signalLevel => \&signalLevel,
1001 warnLevel => \&warnLevel,
1002 dieLevel => \&dieLevel,
1003 tkRunning => \&tkRunning,
1004 ornaments => \&ornaments,
1005 RemotePort => \&RemotePort,
1006 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1007);
1008
69893cff
RGS
1009=pod
1010
1011Last, the C<%optionRequire> notes modules that must be C<require>d if an
1012option is used.
1013
1014=cut
d338d6fe 1015
69893cff
RGS
1016# Note that this list is not complete: several options not listed here
1017# actually require that dumpvar.pl be loaded for them to work, but are
1018# not in the table. A subsequent patch will correct this problem; for
1019# the moment, we're just recommenting, and we are NOT going to change
1020# function.
6b24a4b7
SF
1021use vars qw(%optionRequire);
1022
eda6e075 1023%optionRequire = (
69893cff
RGS
1024 compactDump => 'dumpvar.pl',
1025 veryCompact => 'dumpvar.pl',
1026 quote => 'dumpvar.pl',
e22ea7cc 1027);
69893cff
RGS
1028
1029=pod
1030
1031There are a number of initialization-related variables which can be set
1032by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1033variable. These are:
1034
1035=over 4
1036
1037=item C<$rl> - readline control XXX needs more explanation
1038
1039=item C<$warnLevel> - whether or not debugger takes over warning handling
1040
1041=item C<$dieLevel> - whether or not debugger takes over die handling
1042
1043=item C<$signalLevel> - whether or not debugger takes over signal handling
1044
1045=item C<$pre> - preprompt actions (array reference)
1046
1047=item C<$post> - postprompt actions (array reference)
1048
1049=item C<$pretype>
1050
1051=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1052
1053=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1054
1055=back
1056
1057=cut
d338d6fe
PP
1058
1059# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1060$rl = 1 unless defined $rl;
1061$warnLevel = 1 unless defined $warnLevel;
1062$dieLevel = 1 unless defined $dieLevel;
1063$signalLevel = 1 unless defined $signalLevel;
1064$pre = [] unless defined $pre;
1065$post = [] unless defined $post;
1066$pretype = [] unless defined $pretype;
1067$CreateTTY = 3 unless defined $CreateTTY;
1068$CommandSet = '580' unless defined $CommandSet;
1069
2cbb2ee1
RGS
1070share($rl);
1071share($warnLevel);
1072share($dieLevel);
1073share($signalLevel);
1074share($pre);
1075share($post);
1076share($pretype);
1077share($rl);
1078share($CreateTTY);
1079share($CommandSet);
1080
69893cff
RGS
1081=pod
1082
1083The default C<die>, C<warn>, and C<signal> handlers are set up.
1084
1085=cut
055fd3a9 1086
d338d6fe
PP
1087warnLevel($warnLevel);
1088dieLevel($dieLevel);
1089signalLevel($signalLevel);
055fd3a9 1090
69893cff
RGS
1091=pod
1092
1093The pager to be used is needed next. We try to get it from the
5561b870 1094environment first. If it's not defined there, we try to find it in
69893cff
RGS
1095the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1096then call the C<pager()> function to save the pager name.
1097
1098=cut
1099
1100# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1101pager(
e22ea7cc 1102
69893cff 1103 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1104 defined $ENV{PAGER}
1105 ? $ENV{PAGER}
69893cff
RGS
1106
1107 # If not, see if Config.pm defines it.
e22ea7cc
RF
1108 : eval { require Config }
1109 && defined $Config::Config{pager}
1110 ? $Config::Config{pager}
69893cff
RGS
1111
1112 # If not, fall back to 'more'.
e22ea7cc
RF
1113 : 'more'
1114 )
1115 unless defined $pager;
69893cff
RGS
1116
1117=pod
1118
1119We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1120recall character (C<!> unless otherwise defined) and the shell escape
1121character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1122neither works in the debugger at the moment.
1123
1124=cut
1125
055fd3a9 1126setman();
69893cff
RGS
1127
1128# Set up defaults for command recall and shell escape (note:
1129# these currently don't work in linemode debugging).
2218c045
SF
1130recallCommand("!") unless defined $prc;
1131shellBang("!") unless defined $psh;
69893cff
RGS
1132
1133=pod
1134
1135We then set up the gigantic string containing the debugger help.
1136We also set the limit on the number of arguments we'll display during a
1137trace.
1138
1139=cut
1140
04e43a21 1141sethelp();
69893cff
RGS
1142
1143# If we didn't get a default for the length of eval/stack trace args,
1144# set it here.
1d06cb2d 1145$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1146
1147=head2 SETTING UP THE DEBUGGER GREETING
1148
be9a9b1d 1149The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1150running, and whether the current debugger is the primary or a child.
1151
1152If we are the primary, we just hang onto our pid so we'll have it when
1153or if we start a child debugger. If we are a child, we'll set things up
1154so we'll have a unique greeting and so the parent will give us our own
1155TTY later.
1156
1157We save the current contents of the C<PERLDB_PIDS> environment variable
1158because we mess around with it. We'll also need to hang onto it because
1159we'll need it if we restart.
1160
1161Child debuggers make a label out of the current PID structure recorded in
1162PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1163yet so the parent will give them one later via C<resetterm()>.
1164
1165=cut
1166
e22ea7cc 1167# Save the current contents of the environment; we're about to
69893cff 1168# much with it. We'll need this if we have to restart.
6b24a4b7 1169use vars qw($ini_pids);
f1583d8f 1170$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1171
6b24a4b7
SF
1172use vars qw ($pids $term_pid);
1173
e22ea7cc
RF
1174if ( defined $ENV{PERLDB_PIDS} ) {
1175
69893cff 1176 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1177 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1178 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1179
1180 my $env_pids = $ENV{PERLDB_PIDS};
1181 $pids = "[$env_pids]";
1182
1183 # Unless we are on OpenVMS, all programs under the DCL shell run under
1184 # the same PID.
1185
1186 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1187 $term_pid = $$;
1188 }
1189 else {
1190 $ENV{PERLDB_PIDS} .= "->$$";
1191 $term_pid = -1;
1192 }
1193
69893cff
RGS
1194} ## end if (defined $ENV{PERLDB_PIDS...
1195else {
e22ea7cc
RF
1196
1197 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1198 # child debugger, and mark us as the parent, so we'll know to set up
1199 # more TTY's is we have to.
1200 $ENV{PERLDB_PIDS} = "$$";
619a0444 1201 $pids = "[pid=$$]";
e22ea7cc 1202 $term_pid = $$;
f1583d8f 1203}
69893cff 1204
6b24a4b7 1205use vars qw($pidprompt);
f1583d8f 1206$pidprompt = '';
69893cff
RGS
1207
1208# Sets up $emacs as a synonym for $slave_editor.
6b24a4b7 1209use vars qw($slave_editor);
69893cff
RGS
1210*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1211
1212=head2 READING THE RC FILE
1213
b570d64b 1214The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1215running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1216
b570d64b 1217=cut
69893cff
RGS
1218
1219# As noted, this test really doesn't check accurately that the debugger
1220# is running at a terminal or not.
d338d6fe 1221
6b24a4b7 1222use vars qw($rcfile);
fb4d8a6c
SF
1223{
1224 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1225 # this is the wrong metric!
1226 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1227}
1228
69893cff
RGS
1229=pod
1230
1231The debugger does a safety test of the file to be read. It must be owned
1232either by the current user or root, and must only be writable by the owner.
1233
1234=cut
1235
1236# This wraps a safety test around "do" to read and evaluate the init file.
1237#
055fd3a9
GS
1238# This isn't really safe, because there's a race
1239# between checking and opening. The solution is to
1240# open and fstat the handle, but then you have to read and
1241# eval the contents. But then the silly thing gets
69893cff
RGS
1242# your lexical scope, which is unfortunate at best.
1243sub safe_do {
055fd3a9
GS
1244 my $file = shift;
1245
1246 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1247 local $SIG{__WARN__};
1248 local $SIG{__DIE__};
055fd3a9 1249
e22ea7cc 1250 unless ( is_safe_file($file) ) {
69893cff 1251 CORE::warn <<EO_GRIPE;
055fd3a9 1252perldb: Must not source insecure rcfile $file.
b570d64b 1253 You or the superuser must be the owner, and it must not
69893cff 1254 be writable by anyone but its owner.
055fd3a9 1255EO_GRIPE
69893cff
RGS
1256 return;
1257 } ## end unless (is_safe_file($file...
055fd3a9
GS
1258
1259 do $file;
1260 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1261} ## end sub safe_do
055fd3a9 1262
69893cff
RGS
1263# This is the safety test itself.
1264#
055fd3a9
GS
1265# Verifies that owner is either real user or superuser and that no
1266# one but owner may write to it. This function is of limited use
1267# when called on a path instead of upon a handle, because there are
1268# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1269# eventually accessed is the same as the one tested.
055fd3a9
GS
1270# Assumes that the file's existence is not in doubt.
1271sub is_safe_file {
1272 my $path = shift;
69893cff 1273 stat($path) || return; # mysteriously vaporized
e22ea7cc 1274 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1275
1276 return 0 if $uid != 0 && $uid != $<;
1277 return 0 if $mode & 022;
1278 return 1;
69893cff 1279} ## end sub is_safe_file
055fd3a9 1280
69893cff 1281# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1282# exists, we safely do it.
1283if ( -f $rcfile ) {
055fd3a9 1284 safe_do("./$rcfile");
69893cff 1285}
e22ea7cc 1286
69893cff 1287# If there isn't one here, try the user's home directory.
e22ea7cc 1288elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1289 safe_do("$ENV{HOME}/$rcfile");
1290}
e22ea7cc 1291
69893cff 1292# Else try the login directory.
e22ea7cc 1293elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1294 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1295}
1296
69893cff 1297# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1298if ( defined $ENV{PERLDB_OPTS} ) {
1299 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1300}
1301
69893cff
RGS
1302=pod
1303
1304The last thing we do during initialization is determine which subroutine is
1305to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1306the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1307(darwin).
69893cff
RGS
1308
1309=cut
1310
1311# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1312# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1313# OS/2, or on Mac OS X. This may need some expansion.
1314
1315if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1316{
b570d64b 1317 if ( defined $remoteport ) {
11653f7f
JJ
1318 # Expect an inetd-like server
1319 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1320 }
1321 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1322 # of terminal this is,
1323 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1324 and defined $ENV{DISPLAY} # and what display it's on,
1325 )
1326 {
1327 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1328 }
1329 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1330 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1331 }
1332 elsif ( $^O eq 'darwin' # If this is Mac OS X
1333 and defined $ENV{TERM_PROGRAM} # and we're running inside
1334 and $ENV{TERM_PROGRAM}
1335 eq 'Apple_Terminal' # Terminal.app
1336 )
1337 {
1338 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1339 }
69893cff 1340} ## end if (not defined &get_fork_TTY...
e22ea7cc 1341
dbb46cec
DQ
1342# untaint $^O, which may have been tainted by the last statement.
1343# see bug [perl #24674]
e22ea7cc
RF
1344$^O =~ m/^(.*)\z/;
1345$^O = $1;
f1583d8f 1346
d12a4851 1347# Here begin the unreadable code. It needs fixing.
055fd3a9 1348
69893cff
RGS
1349=head2 RESTART PROCESSING
1350
1351This section handles the restart command. When the C<R> command is invoked, it
1352tries to capture all of the state it can into environment variables, and
1353then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1354if C<PERLDB_RESTART> is there; if so, we reload all the information that
1355the R command stuffed into the environment variables.
1356
b570d64b 1357 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1358 PERLDB_HIST - command history, if it's available
1359 PERLDB_ON_LOAD - breakpoints set by the rc file
1360 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1361 PERLDB_VISITED - files that had breakpoints
1362 PERLDB_FILE_... - breakpoints for a file
1363 PERLDB_OPT - active options
1364 PERLDB_INC - the original @INC
1365 PERLDB_PRETYPE - preprompt debugger actions
1366 PERLDB_PRE - preprompt Perl code
1367 PERLDB_POST - post-prompt Perl code
1368 PERLDB_TYPEAHEAD - typeahead captured by readline()
1369
1370We chug through all these variables and plug the values saved in them
1371back into the appropriate spots in the debugger.
1372
1373=cut
1374
6b24a4b7
SF
1375use vars qw(@hist @truehist %postponed_file @typeahead);
1376
fb0fb5f4
SF
1377sub _restore_shared_globals_after_restart
1378{
1379 @hist = get_list('PERLDB_HIST');
1380 %break_on_load = get_list("PERLDB_ON_LOAD");
1381 %postponed = get_list("PERLDB_POSTPONE");
1382
1383 share(@hist);
1384 share(@truehist);
1385 share(%break_on_load);
1386 share(%postponed);
1387}
1388
e18a02a6 1389sub _restore_breakpoints_and_actions {
e22ea7cc 1390
e22ea7cc 1391 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1392
bdba49ad
SF
1393 for my $file_idx ( 0 .. $#had_breakpoints ) {
1394 my $filename = $had_breakpoints[$file_idx];
1395 my %pf = get_list("PERLDB_FILE_$file_idx");
1396 $postponed_file{ $filename } = \%pf if %pf;
1397 my @lines = sort {$a <=> $b} keys(%pf);
1398 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1399 for my $line_idx (0 .. $#lines) {
1400 _set_breakpoint_enabled_status(
1401 $filename,
1402 $lines[$line_idx],
1403 ($enabled_statuses[$line_idx] ? 1 : ''),
1404 );
1405 }
e22ea7cc 1406 }
69893cff 1407
e18a02a6
SF
1408 return;
1409}
1410
ca50076b
SF
1411sub _restore_options_after_restart
1412{
1413 my %options_map = get_list("PERLDB_OPT");
1414
1415 while ( my ( $opt, $val ) = each %options_map ) {
1416 $val =~ s/[\\\']/\\$1/g;
1417 parse_options("$opt'$val'");
1418 }
1419
1420 return;
1421}
1422
18580168
SF
1423sub _restore_globals_after_restart
1424{
1425 # restore original @INC
1426 @INC = get_list("PERLDB_INC");
1427 @ini_INC = @INC;
1428
1429 # return pre/postprompt actions and typeahead buffer
1430 $pretype = [ get_list("PERLDB_PRETYPE") ];
1431 $pre = [ get_list("PERLDB_PRE") ];
1432 $post = [ get_list("PERLDB_POST") ];
1433 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1434
1435 return;
1436}
1437
fb0fb5f4 1438
e18a02a6
SF
1439if ( exists $ENV{PERLDB_RESTART} ) {
1440
1441 # We're restarting, so we don't need the flag that says to restart anymore.
1442 delete $ENV{PERLDB_RESTART};
1443
1444 # $restart = 1;
fb0fb5f4 1445 _restore_shared_globals_after_restart();
e18a02a6
SF
1446
1447 _restore_breakpoints_and_actions();
1448
69893cff 1449 # restore options
ca50076b 1450 _restore_options_after_restart();
69893cff 1451
18580168 1452 _restore_globals_after_restart();
69893cff
RGS
1453} ## end if (exists $ENV{PERLDB_RESTART...
1454
1455=head2 SETTING UP THE TERMINAL
1456
1457Now, we'll decide how the debugger is going to interact with the user.
1458If there's no TTY, we set the debugger to run non-stop; there's not going
1459to be anyone there to enter commands.
1460
1461=cut
54d04a52 1462
ebd0282e 1463use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1464use vars qw($lineinfo $doccmd);
1465
ebd0282e
SF
1466our ($runnonstop);
1467
d338d6fe 1468if ($notty) {
69893cff 1469 $runnonstop = 1;
2dbd01ad 1470 share($runnonstop);
69893cff 1471}
d12a4851 1472
69893cff
RGS
1473=pod
1474
1475If there is a TTY, we have to determine who it belongs to before we can
1476proceed. If this is a slave editor or graphical debugger (denoted by
1477the first command-line switch being '-emacs'), we shift this off and
1478set C<$rl> to 0 (XXX ostensibly to do straight reads).
1479
1480=cut
1481
1482else {
e22ea7cc 1483
69893cff
RGS
1484 # Is Perl being run from a slave editor or graphical debugger?
1485 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1486 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1487 $rl = 0;
1488 shift(@main::ARGV);
1489 }
e22ea7cc
RF
1490
1491 #require Term::ReadLine;
d12a4851 1492
69893cff
RGS
1493=pod
1494
1495We then determine what the console should be on various systems:
1496
1497=over 4
1498
1499=item * Cygwin - We use C<stdin> instead of a separate device.
1500
1501=cut
1502
e22ea7cc
RF
1503 if ( $^O eq 'cygwin' ) {
1504
69893cff
RGS
1505 # /dev/tty is binary. use stdin for textmode
1506 undef $console;
1507 }
1508
1509=item * Unix - use C</dev/tty>.
1510
1511=cut
1512
e22ea7cc 1513 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1514 $console = "/dev/tty";
1515 }
1516
1517=item * Windows or MSDOS - use C<con>.
1518
1519=cut
1520
e22ea7cc 1521 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1522 $console = "con";
1523 }
1524
69893cff
RGS
1525=item * VMS - use C<sys$command>.
1526
1527=cut
1528
1529 else {
e22ea7cc 1530
69893cff
RGS
1531 # everything else is ...
1532 $console = "sys\$command";
d12a4851 1533 }
69893cff
RGS
1534
1535=pod
1536
1537=back
1538
1539Several other systems don't use a specific console. We C<undef $console>
1540for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1541with a slave editor, Epoc).
1542
1543=cut
d12a4851 1544
e22ea7cc
RF
1545 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1546
69893cff 1547 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1548 $console = undef;
1549 }
1550
1551 if ( $^O eq 'NetWare' ) {
d12a4851 1552
69893cff
RGS
1553 # /dev/tty is binary. use stdin for textmode
1554 $console = undef;
1555 }
d12a4851 1556
69893cff
RGS
1557 # In OS/2, we need to use STDIN to get textmode too, even though
1558 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1559 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1560 { # In OS/2
1561 $console = undef;
1562 }
1563
1564 # EPOC also falls into the 'got to use STDIN' camp.
1565 if ( $^O eq 'epoc' ) {
1566 $console = undef;
1567 }
d12a4851 1568
69893cff
RGS
1569=pod
1570
1571If there is a TTY hanging around from a parent, we use that as the console.
1572
1573=cut
1574
e22ea7cc 1575 $console = $tty if defined $tty;
d12a4851 1576
b570d64b 1577=head2 SOCKET HANDLING
69893cff
RGS
1578
1579The debugger is capable of opening a socket and carrying out a debugging
1580session over the socket.
1581
1582If C<RemotePort> was defined in the options, the debugger assumes that it
1583should try to start a debugging session on that port. It builds the socket
1584and then tries to connect the input and output filehandles to it.
1585
1586=cut
1587
1588 # Handle socket stuff.
e22ea7cc
RF
1589
1590 if ( defined $remoteport ) {
1591
69893cff
RGS
1592 # If RemotePort was defined in the options, connect input and output
1593 # to the socket.
11653f7f 1594 $IN = $OUT = connect_remoteport();
69893cff
RGS
1595 } ## end if (defined $remoteport)
1596
1597=pod
1598
1599If no C<RemotePort> was defined, and we want to create a TTY on startup,
1600this is probably a situation where multiple debuggers are running (for example,
1601a backticked command that starts up another debugger). We create a new IN and
1602OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1603and if we can.
1604
1605=cut
1606
1607 # Non-socket.
1608 else {
e22ea7cc 1609
69893cff
RGS
1610 # Two debuggers running (probably a system or a backtick that invokes
1611 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1612 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1613 # know how, and we can.
e22ea7cc
RF
1614 create_IN_OUT(4) if $CreateTTY & 4;
1615 if ($console) {
1616
69893cff 1617 # If we have a console, check to see if there are separate ins and
cd1191f1 1618 # outs to open. (They are assumed identical if not.)
69893cff 1619
e22ea7cc
RF
1620 my ( $i, $o ) = split /,/, $console;
1621 $o = $i unless defined $o;
69893cff 1622
69893cff 1623 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1624 open( IN, "+<$i" )
1625 || open( IN, "<$i" )
1626 || open( IN, "<&STDIN" );
1627
69893cff
RGS
1628 # read/write/create/clobber out, or write/create/clobber out,
1629 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1630 open( OUT, "+>$o" )
1631 || open( OUT, ">$o" )
1632 || open( OUT, ">&STDERR" )
1633 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1634
1635 } ## end if ($console)
1636 elsif ( not defined $console ) {
1637
1638 # No console. Open STDIN.
1639 open( IN, "<&STDIN" );
1640
1641 # merge with STDERR, or with STDOUT.
1642 open( OUT, ">&STDERR" )
1643 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1644 $console = 'STDIN/OUT';
69893cff
RGS
1645 } ## end elsif (not defined $console)
1646
1647 # Keep copies of the filehandles so that when the pager runs, it
1648 # can close standard input without clobbering ours.
2b0b9dd1
SF
1649 if ($console or (not defined($console))) {
1650 $IN = \*IN;
1651 $OUT = \*OUT;
1652 }
e22ea7cc
RF
1653 } ## end elsif (from if(defined $remoteport))
1654
1655 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1656 $OUT->autoflush(1);
e22ea7cc
RF
1657
1658 # Line info goes to debugger output unless pointed elsewhere.
1659 # Pointing elsewhere makes it possible for slave editors to
1660 # keep track of file and position. We have both a filehandle
1661 # and a I/O description to keep track of.
1662 $LINEINFO = $OUT unless defined $LINEINFO;
1663 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1664 # share($LINEINFO); # <- unable to share globs
1665 share($lineinfo); #
e22ea7cc 1666
69893cff
RGS
1667=pod
1668
1669To finish initialization, we show the debugger greeting,
1670and then call the C<afterinit()> subroutine if there is one.
1671
1672=cut
d12a4851 1673
e22ea7cc
RF
1674 # Show the debugger greeting.
1675 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1676 unless ($runnonstop) {
1677 local $\ = '';
1678 local $, = '';
1679 if ( $term_pid eq '-1' ) {
1680 print $OUT "\nDaughter DB session started...\n";
1681 }
1682 else {
1683 print $OUT "\nLoading DB routines from $header\n";
1684 print $OUT (
1685 "Editor support ",
1686 $slave_editor ? "enabled" : "available", ".\n"
1687 );
1688 print $OUT
1f874cb6 1689"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1690 } ## end else [ if ($term_pid eq '-1')
1691 } ## end unless ($runnonstop)
1692} ## end else [ if ($notty)
1693
1694# XXX This looks like a bug to me.
1695# Why copy to @ARGS and then futz with @args?
d338d6fe 1696@ARGS = @ARGV;
6b24a4b7 1697# for (@args) {
69893cff
RGS
1698 # Make sure backslashes before single quotes are stripped out, and
1699 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1700 # s/\'/\\\'/g; # removed while not justified understandably
1701 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1702# }
d338d6fe 1703
e22ea7cc 1704# If there was an afterinit() sub defined, call it. It will get
69893cff 1705# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1706if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1707 afterinit();
d338d6fe 1708}
e22ea7cc 1709
69893cff 1710# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1711use vars qw($I_m_init);
1712
43aed9ee
IZ
1713$I_m_init = 1;
1714
d338d6fe
PP
1715############################################################ Subroutines
1716
69893cff
RGS
1717=head1 SUBROUTINES
1718
1719=head2 DB
1720
1721This gigantic subroutine is the heart of the debugger. Called before every
1722statement, its job is to determine if a breakpoint has been reached, and
1723stop if so; read commands from the user, parse them, and execute
b468dcb6 1724them, and then send execution off to the next statement.
69893cff
RGS
1725
1726Note that the order in which the commands are processed is very important;
1727some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1728to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1729but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1730see what's happening in any given command.
1731
1732=cut
1733
6b24a4b7
SF
1734use vars qw(
1735 $action
1736 %alias
1737 $cmd
1738 $doret
1739 $fall_off_end
1740 $file
1741 $filename_ini
1742 $finished
1743 %had_breakpoints
1744 $incr
1745 $laststep
1746 $level
1747 $max
6b24a4b7
SF
1748 $package
1749 $rc
1750 $sh
6b24a4b7 1751 $try
2c247e84 1752 $end
6b24a4b7
SF
1753);
1754
8ad70697
SF
1755our ( $stack_depth, @stack, @to_watch, @old_watch, );
1756
6791e41b
SF
1757sub _DB__determine_if_we_should_break
1758{
1759 # if we have something here, see if we should break.
1760 # $stop is lexical and local to this block - $action on the other hand
1761 # is global.
1762 my $stop;
1763
1764 if ( $dbline{$line}
1765 && _is_breakpoint_enabled($filename, $line)
1766 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1767 {
1768
1769 # Stop if the stop criterion says to just stop.
1770 if ( $stop eq '1' ) {
1771 $signal |= 1;
1772 }
1773
1774 # It's a conditional stop; eval it in the user's context and
1775 # see if we should stop. If so, remove the one-time sigil.
1776 elsif ($stop) {
1777 $evalarg = "\$DB::signal |= 1 if do {$stop}";
1778 &eval;
1779 # If the breakpoint is temporary, then delete its enabled status.
1780 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1781 _cancel_breakpoint_temp_enabled_status($filename, $line);
1782 }
1783 }
1784 } ## end if ($dbline{$line} && ...
1785}
1786
8481f647
SF
1787sub _DB__is_finished {
1788 if ($finished and $level <= 1) {
1789 end_report();
1790 return 1;
1791 }
1792 else {
1793 return;
1794 }
1795}
1796
32bbadc6
SF
1797sub _DB__read_next_cmd
1798{
1799 my ($tid) = @_;
1800
1801 # We have a terminal, or can get one ...
1802 if (!$term) {
1803 setterm();
1804 }
1805
1806 # ... and it belogs to this PID or we get one for this PID ...
1807 if ($term_pid != $$) {
1808 resetterm(1);
1809 }
1810
1811 # ... and we got a line of command input ...
1812 $cmd = DB::readline(
1813 "$pidprompt $tid DB"
1814 . ( '<' x $level )
1815 . ( $#hist + 1 )
1816 . ( '>' x $level ) . " "
1817 );
1818
1819 return defined($cmd);
1820}
1821
7013f40c
SF
1822sub _DB__trim_command_and_return_first_component {
1823 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1824 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1825
1826 $cmd =~ m{\A(\S*)};
1827 return $1;
1828}
1829
2b0b9dd1
SF
1830sub DB {
1831
1832 # lock the debugger and get the thread id for the prompt
1833 lock($DBGR);
1834 my $tid;
1835 my $position;
1836 my ($prefix, $after, $infix);
1837 my $pat;
22fc883d 1838 my $explicit_stop;
2b0b9dd1
SF
1839
1840 if ($ENV{PERL5DB_THREADED}) {
1841 $tid = eval { "[".threads->tid."]" };
1842 }
1843
22fc883d
SF
1844 my $obj = DB::Obj->new(
1845 {
1846 position => \$position,
1847 prefix => \$prefix,
1848 after => \$after,
1849 explicit_stop => \$explicit_stop,
1850 infix => \$infix,
1851 },
1852 );
1853
1854 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 1855
69893cff
RGS
1856 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
1857 # The code being debugged may have altered them.
d338d6fe 1858 &save;
69893cff
RGS
1859
1860 # Since DB::DB gets called after every line, we can use caller() to
1861 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 1862 # caller is returning all the extra information when called from the
69893cff 1863 # debugger.
e22ea7cc 1864 local ( $package, $filename, $line ) = caller;
6b24a4b7 1865 $filename_ini = $filename;
69893cff
RGS
1866
1867 # set up the context for DB::eval, so it can properly execute
1868 # code on behalf of the user. We add the package in so that the
1869 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 1870 local $usercontext = _calc_usercontext($package);
69893cff
RGS
1871
1872 # Create an alias to the active file magical array to simplify
1873 # the code here.
e22ea7cc 1874 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 1875
69893cff 1876 # Last line in the program.
55783941 1877 $max = $#dbline;
69893cff 1878
22fc883d 1879 _DB__determine_if_we_should_break(@_);
69893cff
RGS
1880
1881 # Preserve the current stop-or-not, and see if any of the W
1882 # (watch expressions) has changed.
36477c24 1883 my $was_signal = $signal;
69893cff
RGS
1884
1885 # If we have any watch expressions ...
22fc883d 1886 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
1887
1888=head2 C<watchfunction()>
1889
1890C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 1891function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
1892current package, filename, and line as its parameters.
1893
b570d64b 1894The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
1895debugger's context, so it has access to all of the debugger's internal
1896data structures and functions.
1897
1898C<watchfunction()> can control the debugger's actions. Any of the following
1899will cause the debugger to return control to the user's program after
1900C<watchfunction()> executes:
1901
b570d64b 1902=over 4
69893cff 1903
be9a9b1d
AT
1904=item *
1905
1906Returning a false value from the C<watchfunction()> itself.
1907
1908=item *
1909
1910Altering C<$single> to a false value.
1911
1912=item *
69893cff 1913
be9a9b1d 1914Altering C<$signal> to a false value.
69893cff 1915
be9a9b1d 1916=item *
69893cff 1917
be9a9b1d 1918Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
1919check for C<watchfunction()>. This can be done with
1920
1921 $trace &= ~4;
1922
1923=back
1924
1925=cut
1926
e22ea7cc 1927 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
1928 # current package, filename, and line. The function executes in
1929 # the DB:: package.
e22ea7cc
RF
1930 if ( $trace & 4 ) { # User-installed watch
1931 return
1932 if watchfunction( $package, $filename, $line )
1933 and not $single
1934 and not $was_signal
1935 and not( $trace & ~4 );
69893cff
RGS
1936 } ## end if ($trace & 4)
1937
e22ea7cc 1938 # Pick up any alteration to $signal in the watchfunction, and
69893cff 1939 # turn off the signal now.
6027b9a3 1940 $was_signal = $signal;
69893cff
RGS
1941 $signal = 0;
1942
1943=head2 GETTING READY TO EXECUTE COMMANDS
1944
1945The debugger decides to take control if single-step mode is on, the
1946C<t> command was entered, or the user generated a signal. If the program
1947has fallen off the end, we set things up so that entering further commands
1948won't cause trouble, and we say that the program is over.
1949
1950=cut
1951
8dc67a69
SF
1952 # Make sure that we always print if asked for explicitly regardless
1953 # of $trace_to_depth .
22fc883d 1954 $explicit_stop = ($single || $was_signal);
8dc67a69 1955
69893cff
RGS
1956 # Check to see if we should grab control ($single true,
1957 # trace set appropriately, or we got a signal).
8dc67a69 1958 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 1959 $obj->_DB__grab_control(@_);
69893cff
RGS
1960 } ## end if ($single || ($trace...
1961
1962=pod
1963
1964If there's an action to be executed for the line we stopped at, execute it.
b570d64b 1965If there are any preprompt actions, execute those as well.
e219e2fb
RF
1966
1967=cut
1968
69893cff 1969 # If there's an action, do it now.
05da04df
SF
1970 if ($action) {
1971 $evalarg = $action;
1972 DB::eval();
1973 }
e219e2fb 1974
69893cff
RGS
1975 # Are we nested another level (e.g., did we evaluate a function
1976 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
1977 if ( $single || $was_signal ) {
1978
69893cff 1979 # Yes, go down a level.
e22ea7cc 1980 local $level = $level + 1;
69893cff
RGS
1981
1982 # Do any pre-prompt actions.
e22ea7cc 1983 foreach $evalarg (@$pre) {
7c54f46a 1984 DB::eval();
e22ea7cc 1985 }
69893cff
RGS
1986
1987 # Complain about too much recursion if we passed the limit.
05da04df
SF
1988 if ($single & 4) {
1989 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
1990 }
69893cff
RGS
1991
1992 # The line we're currently on. Set $incr to -1 to stay here
1993 # until we get a command that tells us to advance.
e22ea7cc
RF
1994 $start = $line;
1995 $incr = -1; # for backward motion.
69893cff
RGS
1996
1997 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 1998 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
1999
2000=head2 WHERE ARE WE?
2001
2002XXX Relocate this section?
2003
2004The debugger normally shows the line corresponding to the current line of
2005execution. Sometimes, though, we want to see the next line, or to move elsewhere
2006in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2007
be9a9b1d
AT
2008C<$incr> controls by how many lines the I<current> line should move forward
2009after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2010line shouldn't change.
2011
be9a9b1d 2012C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2013move forwards or backwards from when doing an C<L> or C<-> command.
2014
2015C<$max> tells the debugger where the last line of the current file is. It's
2016used to terminate loops most often.
2017
2018=head2 THE COMMAND LOOP
2019
2020Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2021in two parts:
2022
2023=over 4
2024
be9a9b1d
AT
2025=item *
2026
2027The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2028reads a command and then executes it.
2029
be9a9b1d
AT
2030=item *
2031
2032The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2033is wholly contained inside the C<CMD> block and only executes a command.
2034Used to handle commands running inside a pager.
2035
2036=back
2037
2038So why have two labels to restart the loop? Because sometimes, it's easier to
2039have a command I<generate> another command and then re-execute the loop to do
2040the new command. This is faster, but perhaps a bit more convoluted.
2041
2042=cut
2043
2044 # The big command dispatch loop. It keeps running until the
2045 # user yields up control again.
2046 #
2047 # If we have a terminal for input, and we get something back
2048 # from readline(), keep on processing.
6b24a4b7
SF
2049 my $piped;
2050 my $selected;
2051
e22ea7cc 2052 CMD:
32bbadc6 2053 while (_DB__read_next_cmd($tid))
69893cff 2054 {
e22ea7cc 2055
8380a245 2056 share($cmd);
69893cff
RGS
2057 # ... try to execute the input as debugger commands.
2058
2059 # Don't stop running.
2060 $single = 0;
2061
2062 # No signal is active.
2063 $signal = 0;
2064
2065 # Handle continued commands (ending with \):
3d7a2a93 2066 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2067 $cmd .= DB::readline(" cont: ");
e22ea7cc 2068 redo CMD;
3d7a2a93 2069 }
69893cff
RGS
2070
2071=head4 The null command
2072
be9a9b1d 2073A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2074command out of C<$laststep> (where it was recorded previously), and copy it
2075back into C<$cmd> to be executed below. If there wasn't any previous command,
2076we'll do nothing below (no command will match). If there was, we also save it
2077in the command history and fall through to allow the command parsing to pick
2078it up.
2079
2080=cut
2081
2082 # Empty input means repeat the last command.
eeb7da96
SF
2083 if ($cmd eq '') {
2084 $cmd = $laststep;
2085 }
e22ea7cc 2086 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2087 if (length($cmd) >= 2) {
2088 push( @hist, $cmd );
2089 }
e22ea7cc 2090 push( @truehist, $cmd );
2dbd01ad
SF
2091 share(@hist);
2092 share(@truehist);
e22ea7cc
RF
2093
2094 # This is a restart point for commands that didn't arrive
2095 # via direct user input. It allows us to 'redo PIPE' to
2096 # re-execute command processing without reading a new command.
69893cff 2097 PIPE: {
7013f40c 2098 my $i = _DB__trim_command_and_return_first_component();
69893cff
RGS
2099
2100=head3 COMMAND ALIASES
2101
2102The debugger can create aliases for commands (these are stored in the
2103C<%alias> hash). Before a command is executed, the command loop looks it up
2104in the alias hash and substitutes the contents of the alias for the command,
2105completely replacing it.
2106
2107=cut
2108
2109 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2110 if ( $alias{$i} ) {
2111
69893cff
RGS
2112 # Squelch signal handling; we want to keep control here
2113 # if something goes loco during the alias eval.
2114 local $SIG{__DIE__};
2115 local $SIG{__WARN__};
2116
2117 # This is a command, so we eval it in the DEBUGGER's
2118 # scope! Otherwise, we can't see the special debugger
2119 # variables, or get to the debugger's subs. (Well, we
2120 # _could_, but why make it even more complicated?)
2121 eval "\$cmd =~ $alias{$i}";
2122 if ($@) {
2123 local $\ = '';
1f874cb6 2124 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2125 next CMD;
2126 }
2127 } ## end if ($alias{$i})
2128
2129=head3 MAIN-LINE COMMANDS
2130
2131All of these commands work up to and after the program being debugged has
b570d64b 2132terminated.
69893cff
RGS
2133
2134=head4 C<q> - quit
2135
b570d64b 2136Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2137try to execute further, cleaning any restart-related stuff out of the
2138environment, and executing with the last value of C<$?>.
2139
2140=cut
2141
3d7a2a93 2142 if ($cmd eq 'q') {
69893cff
RGS
2143 $fall_off_end = 1;
2144 clean_ENV();
2145 exit $?;
3d7a2a93 2146 }
69893cff 2147
611272bb 2148=head4 C<t> - trace [n]
69893cff
RGS
2149
2150Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2151If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2152
2153=cut
2154
174f9c5e 2155 $obj->_handle_t_command();
69893cff
RGS
2156
2157=head4 C<S> - list subroutines matching/not matching a pattern
2158
2159Walks through C<%sub>, checking to see whether or not to print the name.
2160
2161=cut
2162
826b9a2e
SF
2163 if (my ($print_all_subs, $should_reverse, $Spatt)
2164 = $cmd =~ /\AS(\s+(!)?(.+))?\z/) {
2165 # $Spatt is the pattern (if any) to use.
2166 # Reverse scan?
2167 my $Srev = defined $should_reverse;
2168 # No args - print all subs.
2169 my $Snocheck = !defined $print_all_subs;
69893cff
RGS
2170
2171 # Need to make these sane here.
e22ea7cc
RF
2172 local $\ = '';
2173 local $, = '';
69893cff
RGS
2174
2175 # Search through the debugger's magical hash of subs.
2176 # If $nocheck is true, just print the sub name.
2177 # Otherwise, check it against the pattern. We then use
2178 # the XOR trick to reverse the condition as required.
e22ea7cc
RF
2179 foreach $subname ( sort( keys %sub ) ) {
2180 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
2181 print $OUT $subname, "\n";
2182 }
2183 }
2184 next CMD;
826b9a2e 2185 }
69893cff
RGS
2186
2187=head4 C<X> - list variables in current package
2188
b570d64b 2189Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2190appropriate C<V> command and fall through.
2191
2192=cut
2193
e22ea7cc 2194 $cmd =~ s/^X\b/V $package/;
69893cff
RGS
2195
2196=head4 C<V> - list variables
2197
b570d64b 2198Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2199
2200=cut
2201
2202 # Bare V commands get the currently-being-debugged package
2203 # added.
826b9a2e 2204 if ($cmd eq "V") {
e22ea7cc 2205 $cmd = "V $package";
826b9a2e 2206 }
69893cff
RGS
2207
2208 # V - show variables in package.
826b9a2e
SF
2209 if (my ($new_packname, $new_vars_str) =
2210 $cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
e22ea7cc 2211
69893cff
RGS
2212 # Save the currently selected filehandle and
2213 # force output to debugger's filehandle (dumpvar
2214 # just does "print" for output).
6b24a4b7 2215 my $savout = select($OUT);
69893cff
RGS
2216
2217 # Grab package name and variables to dump.
826b9a2e
SF
2218 $packname = $new_packname;
2219 my @vars = split( ' ', $new_vars_str );
69893cff
RGS
2220
2221 # If main::dumpvar isn't here, get it.
e81465be 2222 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
e22ea7cc
RF
2223 if ( defined &main::dumpvar ) {
2224
69893cff
RGS
2225 # We got it. Turn off subroutine entry/exit messages
2226 # for the moment, along with return values.
e22ea7cc
RF
2227 local $frame = 0;
2228 local $doret = -2;
69893cff
RGS
2229
2230 # must detect sigpipe failures - not catching
2231 # then will cause the debugger to die.
2232 eval {
2233 &main::dumpvar(
2234 $packname,
2235 defined $option{dumpDepth}
e22ea7cc
RF
2236 ? $option{dumpDepth}
2237 : -1, # assume -1 unless specified
69893cff 2238 @vars
e22ea7cc
RF
2239 );
2240 };
2241
2242 # The die doesn't need to include the $@, because
2243 # it will automatically get propagated for us.
2244 if ($@) {
2245 die unless $@ =~ /dumpvar print failed/;
2246 }
2247 } ## end if (defined &main::dumpvar)
2248 else {
2249
2250 # Couldn't load dumpvar.
2251 print $OUT "dumpvar.pl not available.\n";
2252 }
69893cff 2253
69893cff 2254 # Restore the output filehandle, and go round again.
e22ea7cc
RF
2255 select($savout);
2256 next CMD;
826b9a2e 2257 }
69893cff
RGS
2258
2259=head4 C<x> - evaluate and print an expression
2260
2261Hands the expression off to C<DB::eval>, setting it up to print the value
2262via C<dumpvar.pl> instead of just printing it directly.
2263
2264=cut
2265
826b9a2e 2266 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2267 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2268
2269 # handle special "x 3 blah" syntax XXX propagate
2270 # doc back to special variables.
826b9a2e 2271 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2272 $onetimedumpDepth = $1;
2273 }
826b9a2e 2274 }
69893cff
RGS
2275
2276=head4 C<m> - print methods
2277
2278Just uses C<DB::methods> to determine what methods are available.
2279
2280=cut
2281
826b9a2e 2282 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2283 methods($1);
2284 next CMD;
826b9a2e 2285 }
69893cff
RGS
2286
2287 # m expr - set up DB::eval to do the work
826b9a2e 2288 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2289 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2290 }
69893cff
RGS
2291
2292=head4 C<f> - switch files
2293
2294=cut
2295
826b9a2e 2296 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
e22ea7cc 2297 $file =~ s/\s+$//;
69893cff
RGS
2298
2299 # help for no arguments (old-style was return from sub).
e22ea7cc
RF
2300 if ( !$file ) {
2301 print $OUT
2302 "The old f command is now the r command.\n"; # hint
2303 print $OUT "The new f command switches filenames.\n";
2304 next CMD;
2305 } ## end if (!$file)
69893cff
RGS
2306
2307 # if not in magic file list, try a close match.
e22ea7cc
RF
2308 if ( !defined $main::{ '_<' . $file } ) {
2309 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
2310 {
2311 $try = substr( $try, 2 );
1f874cb6 2312 print $OUT "Choosing $try matching '$file':\n";
e22ea7cc
RF
2313 $file = $try;
2314 }
2315 } ## end if (($try) = grep(m#^_<.*$file#...
2316 } ## end if (!defined $main::{ ...
69893cff
RGS
2317
2318 # If not successfully switched now, we failed.
e22ea7cc 2319 if ( !defined $main::{ '_<' . $file } ) {
1f874cb6 2320 print $OUT "No file matching '$file' is loaded.\n";
e22ea7cc
RF
2321 next CMD;
2322 }
69893cff 2323
e22ea7cc
RF
2324 # We switched, so switch the debugger internals around.
2325 elsif ( $file ne $filename ) {
2326 *dbline = $main::{ '_<' . $file };
2327 $max = $#dbline;
2328 $filename = $file;
2329 $start = 1;
2330 $cmd = "l";
2331 } ## end elsif ($file ne $filename)
2332
2333 # We didn't switch; say we didn't.
2334 else {
2335 print $OUT "Already in $file.\n";
2336 next CMD;
2337 }
826b9a2e 2338 }
69893cff
RGS
2339
2340=head4 C<.> - return to last-executed line.
2341
2342We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2343and then we look up the line in the magical C<%dbline> hash.
2344
2345=cut
2346
2347 # . command.
826b9a2e 2348 if ($cmd eq '.') {
e22ea7cc 2349 $incr = -1; # stay at current line
69893cff
RGS
2350
2351 # Reset everything to the old location.
e22ea7cc
RF
2352 $start = $line;
2353 $filename = $filename_ini;
2354 *dbline = $main::{ '_<' . $filename };
2355 $max = $#dbline;
69893cff
RGS
2356
2357 # Now where are we?
e22ea7cc
RF
2358 print_lineinfo($position);
2359 next CMD;
826b9a2e 2360 }
69893cff
RGS
2361
2362=head4 C<-> - back one window
2363
2364We change C<$start> to be one window back; if we go back past the first line,
2365we set it to be the first line. We ser C<$incr> to put us back at the
2366currently-executing line, and then put a C<l $start +> (list one window from
2367C<$start>) in C<$cmd> to be executed later.
2368
2369=cut
2370
2371 # - - back a window.
826b9a2e 2372 if ($cmd eq '-') {
e22ea7cc 2373
69893cff 2374 # back up by a window; go to 1 if back too far.
e22ea7cc
RF
2375 $start -= $incr + $window + 1;
2376 $start = 1 if $start <= 0;
2377 $incr = $window - 1;
69893cff
RGS
2378
2379 # Generate and execute a "l +" command (handled below).
e22ea7cc 2380 $cmd = 'l ' . ($start) . '+';
826b9a2e 2381 }
69893cff 2382
8481f647 2383=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2384
2385In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2386problems, most notably that the default case of several commands destroying
2387the user's work in setting watchpoints, actions, etc. We wanted, however, to
2388retain the old commands for those who were used to using them or who preferred
2389them. At this point, we check for the new commands and call C<cmd_wrapper> to
2390deal with them instead of processing them in-line.
2391
2392=cut
2393
2394 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2395 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2396 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2397 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2398 next CMD;
826b9a2e 2399 }
69893cff
RGS
2400
2401=head4 C<y> - List lexicals in higher scope
2402
826b9a2e 2403Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2404above the current one and then displays then using C<dumpvar.pl>.
2405
2406=cut
2407
826b9a2e
SF
2408 if (my ($match_level, $match_vars)
2409 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
69893cff
RGS
2410
2411 # See if we've got the necessary support.
2412 eval { require PadWalker; PadWalker->VERSION(0.08) }
2413 or &warn(
2414 $@ =~ /locate/
2415 ? "PadWalker module not found - please install\n"
2416 : $@
2417 )
2418 and next CMD;
2419
2420 # Load up dumpvar if we don't have it. If we can, that is.
e81465be 2421 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
69893cff
RGS
2422 defined &main::dumpvar
2423 or print $OUT "dumpvar.pl not available.\n"
2424 and next CMD;
2425
2426 # Got all the modules we need. Find them and print them.
826b9a2e 2427 my @vars = split( ' ', $match_vars || '' );
69893cff
RGS
2428
2429 # Find the pad.
826b9a2e 2430 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
69893cff
RGS
2431
2432 # Oops. Can't find it.
2433 $@ and $@ =~ s/ at .*//, &warn($@), next CMD;
2434
2435 # Show the desired vars with dumplex().
2436 my $savout = select($OUT);
2437
2438 # Have dumplex dump the lexicals.
e22ea7cc 2439 dumpvar::dumplex( $_, $h->{$_},
69893cff 2440 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
e22ea7cc
RF
2441 @vars )
2442 for sort keys %$h;
69893cff
RGS
2443 select($savout);
2444 next CMD;
826b9a2e 2445 }
69893cff
RGS
2446
2447=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2448
2449All of the commands below this point don't work after the program being
2450debugged has ended. All of them check to see if the program has ended; this
2451allows the commands to be relocated without worrying about a 'line of
2452demarcation' above which commands can be entered anytime, and below which
2453they can't.
2454
2455=head4 C<n> - single step, but don't trace down into subs
2456
2457Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2458when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2459so a null command knows what to re-execute.
69893cff
RGS
2460
2461=cut
2462
e22ea7cc 2463 # n - next
826b9a2e 2464 if ($cmd eq 'n') {
8481f647 2465 next CMD if _DB__is_finished();
e22ea7cc 2466
69893cff
RGS
2467 # Single step, but don't enter subs.
2468 $single = 2;
e22ea7cc 2469
69893cff 2470 # Save for empty command (repeat last).
e22ea7cc
RF
2471 $laststep = $cmd;
2472 last CMD;
826b9a2e 2473 }
69893cff
RGS
2474
2475=head4 C<s> - single-step, entering subs
2476
826b9a2e 2477Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2478subs. Also saves C<s> as C<$lastcmd>.
2479
2480=cut
2481
2482 # s - single step.
826b9a2e 2483 if ($cmd eq 's') {
e22ea7cc 2484
69893cff
RGS
2485 # Get out and restart the command loop if program
2486 # has finished.
8481f647 2487 next CMD if _DB__is_finished();
e22ea7cc 2488
69893cff 2489 # Single step should enter subs.
e22ea7cc
RF
2490 $single = 1;
2491
69893cff 2492 # Save for empty command (repeat last).
e22ea7cc
RF
2493 $laststep = $cmd;
2494 last CMD;
826b9a2e 2495 }
69893cff
RGS
2496
2497=head4 C<c> - run continuously, setting an optional breakpoint
2498
2499Most of the code for this command is taken up with locating the optional
2500breakpoint, which is either a subroutine name or a line number. We set
2501the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2502in this and all call levels above this one.
2503
2504=cut
2505
2506 # c - start continuous execution.
ef18ae63 2507 if (($i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
e22ea7cc 2508
69893cff
RGS
2509 # Hey, show's over. The debugged program finished
2510 # executing already.
8481f647 2511 next CMD if _DB__is_finished();
69893cff
RGS
2512
2513 # Capture the place to put a one-time break.
ef18ae63 2514 $subname = $i;
69893cff 2515
e22ea7cc
RF
2516 # Probably not needed, since we finish an interactive
2517 # sub-session anyway...
2518 # local $filename = $filename;
2519 # local *dbline = *dbline; # XXX Would this work?!
69893cff
RGS
2520 #
2521 # The above question wonders if localizing the alias
2522 # to the magic array works or not. Since it's commented
2523 # out, we'll just leave that to speculation for now.
2524
2525 # If the "subname" isn't all digits, we'll assume it
2526 # is a subroutine name, and try to find it.
e22ea7cc
RF
2527 if ( $subname =~ /\D/ ) { # subroutine name
2528 # Qualify it to the current package unless it's
2529 # already qualified.
69893cff
RGS
2530 $subname = $package . "::" . $subname
2531 unless $subname =~ /::/;
e22ea7cc 2532
69893cff
RGS
2533 # find_sub will return "file:line_number" corresponding
2534 # to where the subroutine is defined; we call find_sub,
e22ea7cc 2535 # break up the return value, and assign it in one
69893cff 2536 # operation.
e22ea7cc 2537 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
69893cff
RGS
2538
2539 # Force the line number to be numeric.
e22ea7cc 2540 $i += 0;
69893cff
RGS
2541
2542 # If we got a line number, we found the sub.
e22ea7cc
RF
2543 if ($i) {
2544
69893cff
RGS
2545 # Switch all the debugger's internals around so
2546 # we're actually working with that file.
e22ea7cc
RF
2547 $filename = $file;
2548 *dbline = $main::{ '_<' . $filename };
2549
69893cff 2550 # Mark that there's a breakpoint in this file.
e22ea7cc
RF
2551 $had_breakpoints{$filename} |= 1;
2552
69893cff
RGS
2553 # Scan forward to the first executable line
2554 # after the 'sub whatever' line.
e22ea7cc
RF
2555 $max = $#dbline;
2556 ++$i while $dbline[$i] == 0 && $i < $max;
2557 } ## end if ($i)
69893cff
RGS
2558
2559 # We didn't find a sub by that name.
e22ea7cc
RF
2560 else {
2561 print $OUT "Subroutine $subname not found.\n";
2562 next CMD;
2563 }
2564 } ## end if ($subname =~ /\D/)
69893cff
RGS
2565
2566 # At this point, either the subname was all digits (an
2567 # absolute line-break request) or we've scanned through
2568 # the code following the definition of the sub, looking
2569 # for an executable, which we may or may not have found.
2570 #
2571 # If $i (which we set $subname from) is non-zero, we
e22ea7cc
RF
2572 # got a request to break at some line somewhere. On
2573 # one hand, if there wasn't any real subroutine name
2574 # involved, this will be a request to break in the current
2575 # file at the specified line, so we have to check to make
69893cff
RGS
2576 # sure that the line specified really is breakable.
2577 #
2578 # On the other hand, if there was a subname supplied, the
3c4b39be 2579 # preceding block has moved us to the proper file and
69893cff
RGS
2580 # location within that file, and then scanned forward
2581 # looking for the next executable line. We have to make
2582 # sure that one was found.
2583 #
2584 # On the gripping hand, we can't do anything unless the
2585 # current value of $i points to a valid breakable line.
2586 # Check that.
e22ea7cc
RF
2587 if ($i) {
2588
69893cff 2589 # Breakable?
e22ea7cc
RF
2590 if ( $dbline[$i] == 0 ) {
2591 print $OUT "Line $i not breakable.\n";
2592 next CMD;
2593 }
2594
69893cff 2595 # Yes. Set up the one-time-break sigil.
e22ea7cc 2596 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
5d5d9ea3 2597 _enable_breakpoint_temp_enabled_status($filename, $i);
e22ea7cc 2598 } ## end if ($i)
69893cff
RGS
2599
2600 # Turn off stack tracing from here up.
2c247e84
SF
2601 for my $i (0 .. $stack_depth) {
2602 $stack[ $i ] &= ~1;
e22ea7cc
RF
2603 }
2604 last CMD;
ef18ae63 2605 }
69893cff
RGS
2606
2607=head4 C<r> - return from a subroutine
2608
2609For C<r> to work properly, the debugger has to stop execution again
2610immediately after the return is executed. This is done by forcing
2611single-stepping to be on in the call level above the current one. If
2612we are printing return values when a C<r> is executed, set C<$doret>
2613appropriately, and force us out of the command loop.
2614
2615=cut
2616
2617 # r - return from the current subroutine.
ef18ae63 2618 if ($cmd eq 'r') {
e22ea7cc 2619
98dc9551 2620 # Can't do anything if the program's over.
8481f647 2621 next CMD if _DB__is_finished();
e22ea7cc 2622
69893cff 2623 # Turn on stack trace.
e22ea7cc
RF
2624 $stack[$stack_depth] |= 1;
2625
69893cff 2626 # Print return value unless the stack is empty.
e22ea7cc
RF
2627 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
2628 last CMD;
ef18ae63 2629 }
69893cff 2630
69893cff
RGS
2631=head4 C<T> - stack trace
2632
2633Just calls C<DB::print_trace>.
2634
2635=cut
2636
ef18ae63 2637 if ($cmd eq 'T') {
e22ea7cc
RF
2638 print_trace( $OUT, 1 ); # skip DB
2639 next CMD;
ef18ae63 2640 }
69893cff
RGS
2641
2642=head4 C<w> - List window around current line.
2643
2644Just calls C<DB::cmd_w>.
2645
2646=cut
2647
ef18ae63
SF
2648 if (my ($arg) = $cmd =~ /\Aw\b\s*(.*)/s) {
2649 &cmd_w( 'w', $arg );
2650 next CMD;
2651 }
69893cff
RGS
2652
2653=head4 C<W> - watch-expression processing.
2654
b570d64b 2655Just calls C<DB::cmd_W>.
69893cff
RGS
2656
2657=cut
2658
ef18ae63
SF
2659 if (my ($arg) = $cmd =~ /\AW\b\s*(.*)/s) {
2660 &cmd_W( 'W', $arg );
2661 next CMD;
2662 }
69893cff
RGS
2663
2664=head4 C</> - search forward for a string in the source
2665
ef18ae63 2666We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2667bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2668If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2669mess us up.
2670
2671=cut
2672
ef18ae63
SF
2673 # The pattern as a string.
2674 use vars qw($inpat);
69893cff 2675
ef18ae63 2676 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
69893cff
RGS
2677
2678 # Remove the final slash.
e22ea7cc 2679 $inpat =~ s:([^\\])/$:$1:;
69893cff
RGS
2680
2681 # If the pattern isn't null ...
e22ea7cc 2682 if ( $inpat ne "" ) {
69893cff
RGS
2683
2684 # Turn of warn and die procesing for a bit.
e22ea7cc
RF
2685 local $SIG{__DIE__};
2686 local $SIG{__WARN__};
69893cff
RGS
2687
2688 # Create the pattern.
22fc883d 2689 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
e22ea7cc
RF
2690 if ( $@ ne "" ) {
2691
69893cff 2692 # Oops. Bad pattern. No biscuit.
e22ea7cc 2693 # Print the eval error and go back for more
69893cff 2694 # commands.
e22ea7cc
RF
2695 print $OUT "$@";
2696 next CMD;
2697 }
2698 $pat = $inpat;
2699 } ## end if ($inpat ne "")
69893cff
RGS
2700
2701 # Set up to stop on wrap-around.
e22ea7cc 2702 $end = $start;
69893cff
RGS
2703
2704 # Don't move off the current line.
e22ea7cc 2705 $incr = -1;
69893cff
RGS
2706
2707 # Done in eval so nothing breaks if the pattern
2708 # does something weird.
e22ea7cc 2709 eval '
22fc883d 2710 no strict q/vars/;
e22ea7cc 2711 for (;;) {
69893cff 2712 # Move ahead one line.
e22ea7cc 2713 ++$start;
69893cff
RGS
2714
2715 # Wrap if we pass the last line.
e22ea7cc 2716 $start = 1 if ($start > $max);
69893cff
RGS
2717
2718 # Stop if we have gotten back to this line again,
e22ea7cc 2719 last if ($start == $end);
69893cff
RGS
2720
2721 # A hit! (Note, though, that we are doing
2722 # case-insensitive matching. Maybe a qr//
2723 # expression would be better, so the user could
2724 # do case-sensitive matching if desired.
e22ea7cc
RF
2725 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2726 if ($slave_editor) {
69893cff 2727 # Handle proper escaping in the slave.
e22ea7cc 2728 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2729 }
e22ea7cc 2730 else {
69893cff 2731 # Just print the line normally.
e22ea7cc
RF
2732 print $OUT "$start:\t",$dbline[$start],"\n";
2733 }
69893cff 2734 # And quit since we found something.
e22ea7cc
RF
2735 last;
2736 }
2737 } ';
2738
69893cff 2739 # If we wrapped, there never was a match.
e22ea7cc
RF
2740 print $OUT "/$pat/: not found\n" if ( $start == $end );
2741 next CMD;
ef18ae63 2742 }
69893cff
RGS
2743
2744=head4 C<?> - search backward for a string in the source
2745
2746Same as for C</>, except the loop runs backwards.
2747
2748=cut
2749
2750 # ? - backward pattern search.
ef18ae63 2751 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
69893cff
RGS
2752
2753 # Get the pattern, remove trailing question mark.
e22ea7cc 2754 $inpat =~ s:([^\\])\?$:$1:;
69893cff
RGS
2755
2756 # If we've got one ...
e22ea7cc 2757 if ( $inpat ne "" ) {
69893cff
RGS
2758
2759 # Turn off die & warn handlers.
e22ea7cc
RF
2760 local $SIG{__DIE__};
2761 local $SIG{__WARN__};
2762 eval '$inpat =~ m' . "\a$inpat\a";
2763
2764 if ( $@ ne "" ) {
2765
69893cff 2766 # Ouch. Not good. Print the error.
e22ea7cc
RF
2767 print $OUT $@;
2768 next CMD;
2769 }
2770 $pat = $inpat;
69893cff 2771 } ## end if ($inpat ne "")
e22ea7cc 2772
69893cff 2773 # Where we are now is where to stop after wraparound.
e22ea7cc 2774 $end = $start;
69893cff
RGS
2775
2776 # Don't move away from this line.
e22ea7cc 2777 $incr = -1;
69893cff
RGS
2778
2779 # Search inside the eval to prevent pattern badness
2780 # from killing us.
e22ea7cc 2781 eval '
22fc883d 2782 no strict q/vars/;
e22ea7cc 2783 for (;;) {
69893cff 2784 # Back up a line.
e22ea7cc 2785 --$start;
69893cff
RGS
2786
2787 # Wrap if we pass the first line.
e22ea7cc
RF
2788
2789 $start = $max if ($start <= 0);
69893cff
RGS
2790
2791 # Quit if we get back where we started,
e22ea7cc 2792 last if ($start == $end);
69893cff
RGS
2793
2794 # Match?
e22ea7cc
RF
2795 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) {
2796 if ($slave_editor) {
69893cff 2797 # Yep, follow slave editor requirements.
e22ea7cc 2798 print $OUT "\032\032$filename:$start:0\n";
b570d64b 2799 }
e22ea7cc 2800 else {
69893cff 2801 # Yep, just print normally.
e22ea7cc
RF
2802 print $OUT "$start:\t",$dbline[$start],"\n";
2803 }
69893cff
RGS
2804
2805 # Found, so done.
e22ea7cc
RF
2806 last;
2807 }
2808 } ';
2809
2810 # Say we failed if the loop never found anything,
2811 print $OUT "?$pat?: not found\n" if ( $start == $end );
2812 next CMD;
ef18ae63 2813 }
69893cff
RGS
2814
2815=head4 C<$rc> - Recall command
2816
2817Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2818that the terminal supports history). It find the the command required, puts it
2819into C<$cmd>, and redoes the loop to execute it.
2820
2821=cut
2822
e22ea7cc 2823 # $rc - recall command.
ef18ae63 2824 if (my ($minus, $arg) = $cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
69893cff
RGS
2825
2826 # No arguments, take one thing off history.
e22ea7cc 2827 pop(@hist) if length($cmd) > 1;
69893cff 2828
e22ea7cc 2829 # Relative (- found)?
69893cff 2830 # Y - index back from most recent (by 1 if bare minus)
e22ea7cc 2831 # N - go to that particular command slot or the last
69893cff 2832 # thing if nothing following.
ef18ae63 2833 $i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
69893cff
RGS
2834
2835 # Pick out the command desired.
e22ea7cc 2836 $cmd = $hist[$i];
69893cff
RGS
2837
2838 # Print the command to be executed and restart the loop
2839 # with that command in the buffer.
e22ea7cc
RF
2840 print $OUT $cmd, "\n";
2841 redo CMD;
ef18ae63 2842 }
69893cff
RGS
2843
2844=head4 C<$sh$sh> - C<system()> command
2845
2846Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2847C<STDOUT> from getting messed up.
2848
2849=cut
2850
2851 # $sh$sh - run a shell command (if it's all ASCII).
2852 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2853 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2854
69893cff 2855 # System it.
ef18ae63 2856 &system($arg);
e22ea7cc 2857 next CMD;
ef18ae63 2858 }
69893cff
RGS
2859
2860=head4 C<$rc I<pattern> $rc> - Search command history
2861
2862Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2863If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2864
2865=cut
2866
e22ea7cc 2867 # $rc pattern $rc - find a command in the history.
ef18ae63 2868 if (my ($arg) = $cmd =~ /\A$rc([^$rc].*)\z/) {
e22ea7cc 2869
69893cff 2870 # Create the pattern to use.
ef18ae63 2871 $pat = "^$arg";
69893cff
RGS
2872
2873 # Toss off last entry if length is >1 (and it always is).
e22ea7cc 2874 pop(@hist) if length($cmd) > 1;
69893cff
RGS
2875
2876 # Look backward through the history.
72d7d80d 2877 for ( $i = $#hist ; $i ; --$i ) {
69893cff 2878 # Stop if we find it.
e22ea7cc
RF
2879 last if $hist[$i] =~ /$pat/;
2880 }
2881
2882 if ( !$i ) {
69893cff 2883
69893cff 2884 # Never found it.
e22ea7cc
RF
2885 print $OUT "No such command!\n\n";
2886 next CMD;
2887 }
69893cff
RGS
2888
2889 # Found it. Put it in the buffer, print it, and process it.
e22ea7cc
RF
2890 $cmd = $hist[$i];
2891 print $OUT $cmd, "\n";
2892 redo CMD;
ef18ae63 2893 }
69893cff 2894
ef18ae63 2895=head4 C<$sh> - Invoke a shell
69893cff
RGS
2896
2897Uses C<DB::system> to invoke a shell.
2898
2899=cut
2900
2901 # $sh - start a shell.
ef18ae63 2902 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2903
69893cff
RGS
2904 # Run the user's shell. If none defined, run Bourne.
2905 # We resume execution when the shell terminates.
e22ea7cc
RF
2906 &system( $ENV{SHELL} || "/bin/sh" );
2907 next CMD;
ef18ae63 2908 }
69893cff
RGS
2909
2910=head4 C<$sh I<command>> - Force execution of a command in a shell
2911
2912Like the above, but the command is passed to the shell. Again, we use
2913C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2914
2915=cut
2916
2917 # $sh command - start a shell and run a command in it.
ef18ae63 2918 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
2919
2920 # XXX: using csh or tcsh destroys sigint retvals!
2921 #&system($1); # use this instead
69893cff
RGS
2922
2923 # use the user's shell, or Bourne if none defined.
ef18ae63 2924 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 2925 next CMD;
ef18ae63 2926 }
69893cff
RGS
2927
2928=head4 C<H> - display commands in history
2929
2930Prints the contents of C<@hist> (if any).
2931
2932=cut
2933
ef18ae63 2934 if ($cmd =~ /\AH\b\s*\*/) {
7fddc82f
RF
2935 @hist = @truehist = ();
2936 print $OUT "History cleansed\n";
2937 next CMD;
ef18ae63 2938 }
e22ea7cc 2939
ef18ae63
SF
2940 if (my ($num)
2941 = $cmd =~ /\AH\b\s*(?:-(\d+))?/) {
e22ea7cc
RF
2942
2943 # Anything other than negative numbers is ignored by
69893cff 2944 # the (incorrect) pattern, so this test does nothing.
ef18ae63 2945 $end = $num ? ( $#hist - $num ) : 0;
69893cff
RGS
2946
2947 # Set to the minimum if less than zero.
e22ea7cc 2948 $hist = 0 if $hist < 0;
69893cff 2949
e22ea7cc 2950 # Start at the end of the array.
69893cff
RGS
2951 # Stay in while we're still above the ending value.
2952 # Tick back by one each time around the loop.
72d7d80d 2953 for ( $i = $#hist ; $i > $end ; $i-- ) {
69893cff
RGS
2954
2955 # Print the command unless it has no arguments.
e22ea7cc
RF
2956 print $OUT "$i: ", $hist[$i], "\n"
2957 unless $hist[$i] =~ /^.?$/;
2958 }
2959 next CMD;
ef18ae63 2960 }
69893cff
RGS
2961
2962=head4 C<man, doc, perldoc> - look up documentation
2963
2964Just calls C<runman()> to print the appropriate document.
2965
2966=cut
2967
e22ea7cc 2968 # man, perldoc, doc - show manual pages.
ef18ae63
SF
2969 if (my ($man_page)
2970 = $cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
2971 runman($man_page);
e22ea7cc 2972 next CMD;
ef18ae63 2973 }
69893cff
RGS
2974
2975=head4 C<p> - print
2976
2977Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2978the bottom of the loop.
2979
2980=cut
2981
ef18ae63 2982 my $print_cmd = 'print {$DB::OUT} ';
69893cff 2983 # p - print (no args): print $_.
ef18ae63
SF
2984 if ($cmd eq 'p') {
2985 $cmd = $print_cmd . '$_';
2986 }
69893cff
RGS
2987
2988 # p - print the given expression.
ef18ae63 2989 $cmd =~ s/\Ap\b/$print_cmd /;
69893cff
RGS
2990
2991=head4 C<=> - define command alias
2992
2993Manipulates C<%alias> to add or list command aliases.
2994
2995=cut
2996
e22ea7cc 2997 # = - set up a command alias.
ef18ae63 2998 if ($cmd =~ s/\A=\s*//) {
e22ea7cc
RF
2999 my @keys;
3000 if ( length $cmd == 0 ) {
3001
69893cff 3002 # No args, get current aliases.
e22ea7cc
RF
3003 @keys = sort keys %alias;
3004 }
3005 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3006
69893cff
RGS
3007 # Creating a new alias. $k is alias name, $v is
3008 # alias value.
3009
e22ea7cc
RF
3010 # can't use $_ or kill //g state
3011 for my $x ( $k, $v ) {
3012
3013 # Escape "alarm" characters.
3014 $x =~ s/\a/\\a/g;
3015 }
69893cff
RGS
3016
3017 # Substitute key for value, using alarm chars
e22ea7cc 3018 # as separators (which is why we escaped them in
69893cff 3019 # the command).
e22ea7cc 3020 $alias{$k} = "s\a$k\a$v\a";
69893cff
RGS
3021
3022 # Turn off standard warn and die behavior.
e22ea7cc
RF
3023 local $SIG{__DIE__};
3024 local $SIG{__WARN__};
69893cff
RGS
3025
3026 # Is it valid Perl?
e22ea7cc
RF
3027 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3028
69893cff 3029 # Nope. Bad alias. Say so and get out.
e22ea7cc
RF
3030 print $OUT "Can't alias $k to $v: $@\n";
3031 delete $alias{$k};
3032 next CMD;
3033 }
3034
69893cff 3035 # We'll only list the new one.
e22ea7cc 3036 @keys = ($k);
69893cff
RGS
3037 } ## end elsif (my ($k, $v) = ($cmd...
3038
3039 # The argument is the alias to list.
e22ea7cc
RF
3040 else {
3041 @keys = ($cmd);
3042 }
69893cff
RGS
3043
3044 # List aliases.
e22ea7cc
RF
3045 for my $k (@keys) {
3046
98dc9551 3047 # Messy metaquoting: Trim the substitution code off.
69893cff
RGS
3048 # We use control-G as the delimiter because it's not
3049 # likely to appear in the alias.
e22ea7cc
RF
3050 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3051
69893cff 3052 # Print the alias.
e22ea7cc
RF
3053 print $OUT "$k\t= $1\n";
3054 }
3055 elsif ( defined $alias{$k} ) {
3056
69893cff 3057 # Couldn't trim it off; just print the alias code.
e22ea7cc
RF
3058 print $OUT "$k\t$alias{$k}\n";
3059 }
3060 else {
3061
69893cff 3062 # No such, dude.
e22ea7cc
RF
3063 print "No alias for $k\n";
3064 }
69893cff 3065 } ## end for my $k (@keys)
e22ea7cc 3066 next CMD;
ef18ae63 3067 }
69893cff
RGS
3068
3069=head4 C<source> - read commands from a file.
3070
3071Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
3072pick it up.
3073
3074=cut
3075
e22ea7cc 3076 # source - read commands from a file (or pipe!) and execute.
ef18ae63
SF
3077 if (my ($sourced_fn) = $cmd =~ /\Asource\s+(.*\S)/) {
3078 if ( open my $fh, $sourced_fn ) {
e22ea7cc 3079
69893cff 3080 # Opened OK; stick it in the list of file handles.
e22ea7cc
RF
3081 push @cmdfhs, $fh;
3082 }
3083 else {
3084
3085 # Couldn't open it.
ef18ae63 3086 &warn("Can't execute '$sourced_fn': $!\n");
e22ea7cc
RF
3087 }
3088 next CMD;
ef18ae63 3089 }
69893cff 3090
ef18ae63
SF
3091 if (my ($which_cmd, $position)
3092 = $cmd =~ /^(enable|disable)\s+(\S+)\s*$/) {
e09195af
SF
3093
3094 my ($fn, $line_num);
3095 if ($position =~ m{\A\d+\z})
3096 {
3097 $fn = $filename;
3098 $line_num = $position;
3099 }
ef18ae63
SF
3100 elsif (my ($new_fn, $new_line_num)
3101 = $position =~ m{\A(.*):(\d+)\z}) {
3102 ($fn, $line_num) = ($new_fn, $new_line_num);
e09195af
SF
3103 }
3104 else
3105 {
3106 &warn("Wrong spec for enable/disable argument.\n");
3107 }
3108
3109 if (defined($fn)) {
3110 if (_has_breakpoint_data_ref($fn, $line_num)) {
3111 _set_breakpoint_enabled_status($fn, $line_num,
ef18ae63 3112 ($which_cmd eq 'enable' ? 1 : '')
e09195af
SF
3113 );
3114 }
3115 else {
3116 &warn("No breakpoint set at ${fn}:${line_num}\n");
3117 }
3118 }
3119
3120 next CMD;
ef18ae63 3121 }
e09195af 3122
69893cff
RGS
3123=head4 C<save> - send current history to a file
3124
3125Takes the complete history, (not the shrunken version you see with C<H>),
3126and saves it to the given filename, so it can be replayed using C<source>.
3127
3128Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
3129
3130=cut
3131
3132 # save source - write commands to a file for later use
ef18ae63
SF
3133 if (my ($new_fn) = $cmd =~ /\Asave\s*(.*)\z/) {
3134 my $filename = $new_fn || '.perl5dbrc'; # default?
3135 if ( open my $fh, '>', $filename ) {
e22ea7cc
RF
3136
3137 # chomp to remove extraneous newlines from source'd files
3138 chomp( my @truelist =
3139 map { m/^\s*(save|source)/ ? "#$_" : $_ }
3140 @truehist );
3141 print $fh join( "\n", @truelist );
69893cff 3142 print "commands saved in $file\n";
e22ea7cc
RF
3143 }
3144 else {
ef18ae63 3145 &warn("Can't save debugger commands in '$new_fn': $!\n");
69893cff
RGS
3146 }
3147 next CMD;
ef18ae63 3148 }
69893cff 3149
7fddc82f
RF
3150=head4 C<R> - restart
3151
ef18ae63 3152Restart the debugger session.
7fddc82f
RF
3153
3154=head4 C<rerun> - rerun the current session
3155
3156Return to any given position in the B<true>-history list
3157
3158=cut
3159
3160 # R - restart execution.
3161 # rerun - controlled restart execution.
ff41e38d
SF
3162 if (my ($cmd_cmd, $cmd_params) =
3163 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
3164 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
7fddc82f 3165
ca28b541
AP
3166 # Close all non-system fds for a clean restart. A more
3167 # correct method would be to close all fds that were not
3168 # open when the process started, but this seems to be
3169 # hard. See "debugger 'R'estart and open database
3170 # connections" on p5p.
3171
47d3bbda 3172 my $max_fd = 1024; # default if POSIX can't be loaded
ca28b541 3173 if (eval { require POSIX }) {
5332cc68 3174 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
ca28b541
AP
3175 }
3176
3177 if (defined $max_fd) {
3178 foreach ($^F+1 .. $max_fd-1) {
3179 next unless open FD_TO_CLOSE, "<&=$_";
3180 close(FD_TO_CLOSE);
3181 }
3182 }
3183
7fddc82f
RF
3184 # And run Perl again. We use exec() to keep the
3185 # PID stable (and that way $ini_pids is still valid).
3186 exec(@args) || print $OUT "exec failed: $!\n";
3187
3188 last CMD;
ff41e38d 3189 }
7fddc82f 3190
69893cff
RGS
3191=head4 C<|, ||> - pipe output through the pager.
3192
be9a9b1d 3193For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3194(the program's standard output). For C<||>, we only save C<OUT>. We open a
3195pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3196is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3197set C<$signal>, sending us back into the debugger.
3198
3199We then trim off the pipe symbols and C<redo> the command loop at the
3200C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3201reading another.
3202
3203=cut
3204
3205 # || - run command in the pager, with output to DB::OUT.
ff41e38d 3206 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
3207 if ( $pager =~ /^\|/ ) {
3208
69893cff 3209 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
3210 open( SAVEOUT, ">&STDOUT" )
3211 || &warn("Can't save STDOUT");
3212 open( STDOUT, ">&OUT" )
3213 || &warn("Can't redirect STDOUT");
69893cff 3214 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3215 else {
3216
69893cff 3217 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
3218 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
3219 }
69893cff
RGS
3220
3221 # Fix up environment to record we have less if so.
e22ea7cc
RF
3222 fix_less();
3223
3224 unless ( $piped = open( OUT, $pager ) ) {
69893cff 3225
69893cff 3226 # Couldn't open pipe to pager.
1f874cb6 3227 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
3228 if ( $pager =~ /^\|/ ) {
3229
69893cff 3230 # Redirect I/O back again.
e22ea7cc
RF
3231 open( OUT, ">&STDOUT" ) # XXX: lost message
3232 || &warn("Can't restore DB::OUT");
3233 open( STDOUT, ">&SAVEOUT" )
3234 || &warn("Can't restore STDOUT");
3235 close(SAVEOUT);
69893cff 3236 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3237 else {
3238
69893cff 3239 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3240 open( OUT, ">&STDOUT" ) # XXX: lost message
3241 || &warn("Can't restore DB::OUT");
3242 }
3243 next CMD;
69893cff
RGS
3244 } ## end unless ($piped = open(OUT,...
3245
3246 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3247 $SIG{PIPE} = \&DB::catch
3248 if $pager =~ /^\|/
3249 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3250
70c9432b
SF
3251 OUT->autoflush(1);
3252 # Save current filehandle, and put it back.
e22ea7cc 3253 $selected = select(OUT);
69893cff 3254 # Don't put it back if pager was a pipe.
e22ea7cc 3255 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3256
3257 # Trim off the pipe symbols and run the command now.
ff41e38d 3258 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3259 redo PIPE;
ff41e38d 3260 }
69893cff
RGS
3261
3262=head3 END OF COMMAND PARSING
3263
ff41e38d
SF
3264Anything left in C<$cmd> at this point is a Perl expression that we want to
3265evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3266any variables we might want to address in the C<DB> package.
3267
3268=cut
3269
3270 # t - turn trace on.
ff41e38d
SF
3271 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3272 my $trace_arg = $1;
3273 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3274 }
69893cff
RGS
3275
3276 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3277 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3278 $laststep = 's';
3279 }
69893cff
RGS
3280
3281 # n - single-step, but not into subs. Remember last command
e22ea7cc 3282 # was 'n'.
ff41e38d
SF
3283 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3284 $laststep = 'n';
3285 }
69893cff 3286
e22ea7cc 3287 } # PIPE:
69893cff 3288
e22ea7cc 3289 # Make sure the flag that says "the debugger's running" is
69893cff 3290 # still on, to make sure we get control again.
e22ea7cc 3291 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3292
3293 # Run *our* eval that executes in the caller's context.
7c54f46a 3294 DB::eval();
69893cff
RGS
3295
3296 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3297 if ($onetimeDump) {
3298 $onetimeDump = undef;
69893cff 3299 $onetimedumpDepth = undef;
e22ea7cc
RF
3300 }
3301 elsif ( $term_pid == $$ ) {
8380a245 3302 eval { # May run under miniperl, when not available...
c7e68384
IZ
3303 STDOUT->flush();
3304 STDERR->flush();
8380a245 3305 };
e22ea7cc 3306
69893cff 3307 # XXX If this is the master pid, print a newline.
8380a245 3308 print {$OUT} "\n";
e22ea7cc
RF
3309 }
3310 } ## end while (($term || &setterm...
69893cff
RGS
3311
3312=head3 POST-COMMAND PROCESSING
3313
3314After each command, we check to see if the command output was piped anywhere.
3315If so, we go through the necessary code to unhook the pipe and go back to
3316our standard filehandles for input and output.
3317
3318=cut
3319
e22ea7cc 3320 continue { # CMD:
69893cff
RGS
3321
3322 # At the end of every command:
e22ea7cc
RF
3323 if ($piped) {
3324
69893cff 3325 # Unhook the pipe mechanism now.
e22ea7cc
RF
3326 if ( $pager =~ /^\|/ ) {
3327
69893cff 3328 # No error from the child.
e22ea7cc 3329 $? = 0;
69893cff 3330
e22ea7cc
RF
3331 # we cannot warn here: the handle is missing --tchrist
3332 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3333
e22ea7cc 3334 # most of the $? crud was coping with broken cshisms
69893cff 3335 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3336 if ($?) {
1f874cb6 3337 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3338 if ( $? == -1 ) {
3339 print SAVEOUT "shell returned -1\n";
3340 }
3341 elsif ( $? >> 8 ) {
3342 print SAVEOUT ( $? & 127 )
3343 ? " (SIG#" . ( $? & 127 ) . ")"
3344 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3345 }
3346 else {
3347 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3348 }
69893cff
RGS
3349 } ## end if ($?)
3350
e22ea7cc 3351 # Reopen filehandle for our output (if we can) and
69893cff 3352 # restore STDOUT (if we can).
e22ea7cc
RF
3353 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3354 open( STDOUT, ">&SAVEOUT" )
3355 || &warn("Can't restore STDOUT");
69893cff
RGS
3356
3357 # Turn off pipe exception handler if necessary.
e22ea7cc 3358 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3359
e22ea7cc
RF
3360 # Will stop ignoring SIGPIPE if done like nohup(1)
3361 # does SIGINT but Perl doesn't give us a choice.
69893cff 3362 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3363 else {
3364
69893cff 3365 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3366 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3367 }
69893cff
RGS
3368
3369 # Close filehandle pager was using, restore the normal one
3370 # if necessary,
3371 close(SAVEOUT);
e22ea7cc 3372 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3373
3374 # No pipes now.
e22ea7cc 3375 $piped = "";
69893cff 3376 } ## end if ($piped)
e22ea7cc 3377 } # CMD:
69893cff
RGS
3378
3379=head3 COMMAND LOOP TERMINATION
3380
3381When commands have finished executing, we come here. If the user closed the
3382input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3383evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3384C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3385The interpreter will then execute the next line and then return control to us
3386again.
3387
3388=cut
3389
3390 # No more commands? Quit.
1f874cb6 3391 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3392
3393 # Evaluate post-prompt commands.
e22ea7cc 3394 foreach $evalarg (@$post) {
7c54f46a 3395 DB::eval();
e22ea7cc
RF
3396 }
3397 } # if ($single || $signal)
69893cff
RGS
3398
3399 # Put the user's globals back where you found them.
e22ea7cc 3400 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3401 ();
3402} ## end sub DB
3403
22fc883d
SF
3404package DB::Obj;
3405
3406sub new {
3407 my $class = shift;
3408
3409 my $self = bless {}, $class;
3410
3411 $self->_init(@_);
3412
3413 return $self;
3414}
3415
3416sub _init {
3417 my ($self, $args) = @_;
3418
3419 %{$self} = (%$self, %$args);
3420
3421 return;
3422}
3423
3424{
3425 no strict 'refs';
3426 foreach my $slot_name (qw(after explicit_stop infix position prefix)) {
3427 my $slot = $slot_name;
3428 *{$slot} = sub {
3429 my $self = shift;
3430
3431 if (@_) {
3432 ${ $self->{$slot} } = shift;
3433 }
3434
3435 return ${ $self->{$slot} };
3436 };
8def6eff
SF
3437
3438 *{"append_to_$slot"} = sub {
3439 my $self = shift;
3440 my $s = shift;
3441
3442 return $self->$slot($self->$slot . $s);
3443 };
22fc883d
SF
3444 }
3445}
3446
3447sub _DB_on_init__initialize_globals
3448{
3449 my $self = shift;
3450
3451 # Check for whether we should be running continuously or not.
3452 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3453 if ( $single and not $second_time++ ) {
22fc883d
SF
3454
3455 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3456 if ($runnonstop) { # Disable until signal
22fc883d
SF
3457 # If there's any call stack in place, turn off single
3458 # stepping into subs throughout the stack.
8ad70697
SF
3459 for my $i (0 .. $stack_depth) {
3460 $stack[ $i ] &= ~1;
22fc883d
SF
3461 }
3462
3463 # And we are now no longer in single-step mode.
ebd0282e 3464 $single = 0;
22fc883d
SF
3465
3466 # If we simply returned at this point, we wouldn't get
3467 # the trace info. Fall on through.
3468 # return;
3469 } ## end if ($runnonstop)
3470
8ad70697 3471 elsif ($ImmediateStop) {
22fc883d
SF
3472
3473 # We are supposed to stop here; XXX probably a break.
8ad70697 3474 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3475 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3476 # us into the command loop
3477 }
3478 } ## end if ($single and not $second_time...
3479
3480 # If we're in single-step mode, or an interrupt (real or fake)
3481 # has occurred, turn off non-stop mode.
ebd0282e 3482 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3483
3484 return;
3485}
3486
3487sub _DB__handle_watch_expressions
3488{
3489 my $self = shift;
3490
931ac036 3491 if ( $trace & 2 ) {
8ad70697
SF
3492 for my $n (0 .. $#to_watch) {
3493 $evalarg = $to_watch[$n];
3494 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3495
3496 # Fix context DB::eval() wants to return an array, but
3497 # we need a scalar here.
7c54f46a 3498 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3499 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3500
3501 # Did it change?
8ad70697 3502 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3503
3504 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3505 $signal = 1;
8ad70697
SF
3506 print {$OUT} <<EOP;
3507Watchpoint $n:\t$to_watch[$n] changed:
3508 old value:\t$old_watch[$n]
22fc883d
SF
3509 new value:\t$val
3510EOP
8ad70697 3511 $old_watch[$n] = $val;
22fc883d
SF
3512 } ## end if ($val ne $old_watch...
3513 } ## end for my $n (0 ..
3514 } ## end if ($trace & 2)
3515
3516 return;
3517}
3518
ad46ac70
SF
3519sub _my_print_lineinfo
3520{
3521 my ($self, $i, $incr_pos) = @_;
3522
3523 if ($DB::frame) {
3524 # Print it indented if tracing is on.
8ad70697 3525 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3526 "$i:\t$DB::dbline[$i]" . $self->after );
3527 }
3528 else {
3529 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3530 }
3531}
3532
44a07e3e
SF
3533sub _curr_line {
3534 return $DB::dbline[$DB::line];
3535}
3536
22fc883d
SF
3537sub _DB__grab_control
3538{
3539 my $self = shift;
3540
3541 # Yes, grab control.
3542 if ($DB::slave_editor) {
3543
3544 # Tell the editor to update its position.
3545 $self->position("\032\032${DB::filename}:${DB::line}:0\n");
3546 DB::print_lineinfo($self->position());
3547 }
3548
3549=pod
3550
3551Special check: if we're in package C<DB::fake>, we've gone through the
3552C<END> block at least once. We set up everything so that we can continue
3553to enter commands and have a valid context to be in.
3554
3555=cut
3556
3557 elsif ( $DB::package eq 'DB::fake' ) {
3558
3559 # Fallen off the end already.
3560 if (!$DB::term) {
3561 DB::setterm();
3562 }
3563
3564 DB::print_help(<<EOP);
3565Debugged program terminated. Use B<q> to quit or B<R> to restart,
3566use B<o> I<inhibit_exit> to avoid stopping after program termination,
3567B<h q>, B<h R> or B<h o> to get additional info.
3568EOP
3569
3570 # Set the DB::eval context appropriately.
3571 $DB::package = 'main';
3572 $DB::usercontext = DB::_calc_usercontext($DB::package);
3573 } ## end elsif ($package eq 'DB::fake')
3574
3575=pod
3576
3577If the program hasn't finished executing, we scan forward to the
3578next executable line, print that out, build the prompt from the file and line
3579number information, and print that.
3580
3581=cut
3582