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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
ef18ae63 189The scalar C<${"_<$filename"}> simply contains the string C<<< _<$filename> >>>.
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190This is also the case for evaluated strings that contain subroutines, or
191which are currently being executed. The $filename for C<eval>ed strings looks
d24ca0c5 192like C<(eval 34).
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193
194=head1 DEBUGGER STARTUP
195
196When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for
197non-interactive sessions, C<.perldb> for interactive ones) that can set a number
198of options. In addition, this file may define a subroutine C<&afterinit>
b570d64b 199that will be executed (in the debugger's context) after the debugger has
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200initialized itself.
201
b570d64b 202Next, it checks the C<PERLDB_OPTS> environment variable and treats its
be9a9b1d 203contents as the argument of a C<o> command in the debugger.
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204
205=head2 STARTUP-ONLY OPTIONS
206
207The following options can only be specified at startup.
208To set them in your rcfile, add a call to
209C<&parse_options("optionName=new_value")>.
210
211=over 4
212
b570d64b 213=item * TTY
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214
215the TTY to use for debugging i/o.
216
b570d64b 217=item * noTTY
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218
219if set, goes in NonStop mode. On interrupt, if TTY is not set,
b0e77abc 220uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using
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221Term::Rendezvous. Current variant is to have the name of TTY in this
222file.
223
b570d64b 224=item * ReadLine
69893cff 225
5561b870 226if false, a dummy ReadLine is used, so you can debug
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227ReadLine applications.
228
b570d64b 229=item * NonStop
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230
231if true, no i/o is performed until interrupt.
232
b570d64b 233=item * LineInfo
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234
235file or pipe to print line number info to. If it is a
236pipe, a short "emacs like" message is used.
237
b570d64b 238=item * RemotePort
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239
240host:port to connect to on remote host for remote debugging.
241
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242=item * HistFile
243
244file to store session history to. There is no default and so no
245history file is written unless this variable is explicitly set.
246
247=item * HistSize
248
249number of commands to store to the file specified in C<HistFile>.
250Default is 100.
251
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252=back
253
254=head3 SAMPLE RCFILE
255
256 &parse_options("NonStop=1 LineInfo=db.out");
257 sub afterinit { $trace = 1; }
258
259The script will run without human intervention, putting trace
260information into C<db.out>. (If you interrupt it, you had better
be9a9b1d 261reset C<LineInfo> to something I<interactive>!)
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262
263=head1 INTERNALS DESCRIPTION
264
265=head2 DEBUGGER INTERFACE VARIABLES
266
267Perl supplies the values for C<%sub>. It effectively inserts
be9a9b1d 268a C<&DB::DB();> in front of each place that can have a
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269breakpoint. At each subroutine call, it calls C<&DB::sub> with
270C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN
271{require 'perl5db.pl'}> before the first line.
272
273After each C<require>d file is compiled, but before it is executed, a
274call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename>
275is the expanded name of the C<require>d file (as found via C<%INC>).
276
277=head3 IMPORTANT INTERNAL VARIABLES
278
279=head4 C<$CreateTTY>
280
281Used to control when the debugger will attempt to acquire another TTY to be
b570d64b 282used for input.
69893cff 283
b570d64b 284=over
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285
286=item * 1 - on C<fork()>
287
288=item * 2 - debugger is started inside debugger
289
290=item * 4 - on startup
291
292=back
293
294=head4 C<$doret>
295
296The value -2 indicates that no return value should be printed.
297Any other positive value causes C<DB::sub> to print return values.
298
299=head4 C<$evalarg>
300
301The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current
302contents of C<@_> when C<DB::eval> is called.
303
304=head4 C<$frame>
305
306Determines what messages (if any) will get printed when a subroutine (or eval)
b570d64b 307is entered or exited.
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308
309=over 4
310
311=item * 0 - No enter/exit messages
312
be9a9b1d 313=item * 1 - Print I<entering> messages on subroutine entry
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314
315=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2.
316
be9a9b1d 317=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4.
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318
319=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on.
320
321=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on.
322
323=back
324
be9a9b1d 325To get everything, use C<$frame=30> (or C<o f=30> as a debugger command).
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326The debugger internally juggles the value of C<$frame> during execution to
327protect external modules that the debugger uses from getting traced.
328
329=head4 C<$level>
330
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331Tracks current debugger nesting level. Used to figure out how many
332C<E<lt>E<gt>> pairs to surround the line number with when the debugger
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333outputs a prompt. Also used to help determine if the program has finished
334during command parsing.
335
336=head4 C<$onetimeDump>
337
338Controls what (if anything) C<DB::eval()> will print after evaluating an
339expression.
340
341=over 4
342
343=item * C<undef> - don't print anything
344
345=item * C<dump> - use C<dumpvar.pl> to display the value returned
346
347=item * C<methods> - print the methods callable on the first item returned
348
349=back
350
351=head4 C<$onetimeDumpDepth>
352
be9a9b1d 353Controls how far down C<dumpvar.pl> will go before printing C<...> while
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354dumping a structure. Numeric. If C<undef>, print all levels.
355
356=head4 C<$signal>
357
358Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>,
359which is called before every statement, checks this and puts the user into
360command mode if it finds C<$signal> set to a true value.
361
362=head4 C<$single>
363
364Controls behavior during single-stepping. Stacked in C<@stack> on entry to
365each subroutine; popped again at the end of each subroutine.
366
b570d64b 367=over 4
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368
369=item * 0 - run continuously.
370
be9a9b1d 371=item * 1 - single-step, go into subs. The C<s> command.
69893cff 372
be9a9b1d 373=item * 2 - single-step, don't go into subs. The C<n> command.
69893cff 374
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375=item * 4 - print current sub depth (turned on to force this when C<too much
376recursion> occurs.
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377
378=back
379
380=head4 C<$trace>
381
b570d64b 382Controls the output of trace information.
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383
384=over 4
385
386=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed)
387
388=item * 2 - watch expressions are active
389
390=item * 4 - user defined a C<watchfunction()> in C<afterinit()>
391
392=back
393
394=head4 C<$slave_editor>
395
3961 if C<LINEINFO> was directed to a pipe; 0 otherwise.
397
398=head4 C<@cmdfhs>
399
400Stack of filehandles that C<DB::readline()> will read commands from.
401Manipulated by the debugger's C<source> command and C<DB::readline()> itself.
402
403=head4 C<@dbline>
404
b570d64b 405Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> ,
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406supplied by the Perl interpreter to the debugger. Contains the source.
407
408=head4 C<@old_watch>
409
410Previous values of watch expressions. First set when the expression is
411entered; reset whenever the watch expression changes.
412
413=head4 C<@saved>
414
415Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>)
416so that the debugger can substitute safe values while it's running, and
417restore them when it returns control.
418
419=head4 C<@stack>
420
421Saves the current value of C<$single> on entry to a subroutine.
422Manipulated by the C<c> command to turn off tracing in all subs above the
423current one.
424
425=head4 C<@to_watch>
426
427The 'watch' expressions: to be evaluated before each line is executed.
428
429=head4 C<@typeahead>
430
431The typeahead buffer, used by C<DB::readline>.
432
433=head4 C<%alias>
434
435Command aliases. Stored as character strings to be substituted for a command
436entered.
437
438=head4 C<%break_on_load>
439
440Keys are file names, values are 1 (break when this file is loaded) or undef
441(don't break when it is loaded).
442
443=head4 C<%dbline>
444
be9a9b1d 445Keys are line numbers, values are C<condition\0action>. If used in numeric
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446context, values are 0 if not breakable, 1 if breakable, no matter what is
447in the actual hash entry.
448
449=head4 C<%had_breakpoints>
450
451Keys are file names; values are bitfields:
452
b570d64b 453=over 4
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454
455=item * 1 - file has a breakpoint in it.
456
457=item * 2 - file has an action in it.
458
459=back
460
461A zero or undefined value means this file has neither.
462
463=head4 C<%option>
464
465Stores the debugger options. These are character string values.
466
467=head4 C<%postponed>
468
469Saves breakpoints for code that hasn't been compiled yet.
470Keys are subroutine names, values are:
471
472=over 4
473
be9a9b1d 474=item * C<compile> - break when this sub is compiled
69893cff 475
be9a9b1d 476=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified.
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477
478=back
479
480=head4 C<%postponed_file>
481
482This hash keeps track of breakpoints that need to be set for files that have
483not yet been compiled. Keys are filenames; values are references to hashes.
484Each of these hashes is keyed by line number, and its values are breakpoint
be9a9b1d 485definitions (C<condition\0action>).
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486
487=head1 DEBUGGER INITIALIZATION
488
489The debugger's initialization actually jumps all over the place inside this
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490package. This is because there are several BEGIN blocks (which of course
491execute immediately) spread through the code. Why is that?
69893cff 492
b570d64b 493The debugger needs to be able to change some things and set some things up
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494before the debugger code is compiled; most notably, the C<$deep> variable that
495C<DB::sub> uses to tell when a program has recursed deeply. In addition, the
496debugger has to turn off warnings while the debugger code is compiled, but then
497restore them to their original setting before the program being debugged begins
498executing.
499
500The first C<BEGIN> block simply turns off warnings by saving the current
501setting of C<$^W> and then setting it to zero. The second one initializes
502the debugger variables that are needed before the debugger begins executing.
b570d64b 503The third one puts C<$^X> back to its former value.
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504
505We'll detail the second C<BEGIN> block later; just remember that if you need
506to initialize something before the debugger starts really executing, that's
507where it has to go.
508
509=cut
510
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511package DB;
512
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513use strict;
514
2dbd01ad 515BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl
9eba6a4e 516
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517BEGIN {
518 require feature;
519 $^V =~ /^v(\d+\.\d+)/;
520 feature->import(":$1");
521}
522
54d04a52 523# Debugger for Perl 5.00x; perl5db.pl patch level:
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524use vars qw($VERSION $header);
525
931d9438 526$VERSION = '1.39_05';
69893cff 527
e22ea7cc 528$header = "perl5db.pl version $VERSION";
d338d6fe 529
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530=head1 DEBUGGER ROUTINES
531
532=head2 C<DB::eval()>
533
534This function replaces straight C<eval()> inside the debugger; it simplifies
535the process of evaluating code in the user's context.
536
b570d64b 537The code to be evaluated is passed via the package global variable
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538C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>.
539
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540Before we do the C<eval()>, we preserve the current settings of C<$trace>,
541C<$single>, C<$^D> and C<$usercontext>. The latter contains the
542preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the
543user's current package, grabbed when C<DB::DB> got control. This causes the
544proper context to be used when the eval is actually done. Afterward, we
545restore C<$trace>, C<$single>, and C<$^D>.
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546
547Next we need to handle C<$@> without getting confused. We save C<$@> in a
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548local lexical, localize C<$saved[0]> (which is where C<save()> will put
549C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>,
69893cff 550C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values
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551considered sane by the debugger. If there was an C<eval()> error, we print
552it on the debugger's output. If C<$onetimedump> is defined, we call
553C<dumpit> if it's set to 'dump', or C<methods> if it's set to
554'methods'. Setting it to something else causes the debugger to do the eval
555but not print the result - handy if you want to do something else with it
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556(the "watch expressions" code does this to get the value of the watch
557expression but not show it unless it matters).
558
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559In any case, we then return the list of output from C<eval> to the caller,
560and unwinding restores the former version of C<$@> in C<@saved> as well
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561(the localization of C<$saved[0]> goes away at the end of this scope).
562
563=head3 Parameters and variables influencing execution of DB::eval()
564
565C<DB::eval> isn't parameterized in the standard way; this is to keep the
566debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things.
b570d64b 567The variables listed below influence C<DB::eval()>'s execution directly.
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568
569=over 4
570
571=item C<$evalarg> - the thing to actually be eval'ed
572
be9a9b1d 573=item C<$trace> - Current state of execution tracing
69893cff 574
be9a9b1d 575=item C<$single> - Current state of single-stepping
69893cff 576
b570d64b 577=item C<$onetimeDump> - what is to be displayed after the evaluation
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578
579=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results
580
581=back
582
583The following variables are altered by C<DB::eval()> during its execution. They
b570d64b 584are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>.
69893cff
RGS
585
586=over 4
587
588=item C<@res> - used to capture output from actual C<eval>.
589
590=item C<$otrace> - saved value of C<$trace>.
591
b570d64b 592=item C<$osingle> - saved value of C<$single>.
69893cff
RGS
593
594=item C<$od> - saved value of C<$^D>.
595
596=item C<$saved[0]> - saved value of C<$@>.
597
b570d64b 598=item $\ - for output of C<$@> if there is an evaluation error.
69893cff
RGS
599
600=back
601
602=head3 The problem of lexicals
603
604The context of C<DB::eval()> presents us with some problems. Obviously,
605we want to be 'sandboxed' away from the debugger's internals when we do
606the eval, but we need some way to control how punctuation variables and
b570d64b 607debugger globals are used.
69893cff
RGS
608
609We can't use local, because the code inside C<DB::eval> can see localized
610variables; and we can't use C<my> either for the same reason. The code
611in this routine compromises and uses C<my>.
612
613After this routine is over, we don't have user code executing in the debugger's
614context, so we can use C<my> freely.
615
616=cut
617
618############################################## Begin lexical danger zone
619
620# 'my' variables used here could leak into (that is, be visible in)
621# the context that the code being evaluated is executing in. This means that
622# the code could modify the debugger's variables.
623#
624# Fiddling with the debugger's context could be Bad. We insulate things as
625# much as we can.
626
6b24a4b7
SF
627use vars qw(
628 @args
629 %break_on_load
6b24a4b7
SF
630 $CommandSet
631 $CreateTTY
632 $DBGR
633 @dbline
634 $dbline
635 %dbline
636 $dieLevel
6b24a4b7 637 $filename
6b24a4b7
SF
638 $histfile
639 $histsize
6b24a4b7
SF
640 $IN
641 $inhibit_exit
642 @ini_INC
643 $ini_warn
6b24a4b7
SF
644 $maxtrace
645 $od
6b24a4b7 646 $onetimedumpDepth
6b24a4b7
SF
647 @options
648 $osingle
649 $otrace
6b24a4b7
SF
650 $pager
651 $post
652 %postponed
653 $prc
654 $pre
655 $pretype
656 $psh
657 @RememberOnROptions
658 $remoteport
659 @res
660 $rl
661 @saved
6b24a4b7 662 $signalLevel
6b24a4b7 663 $sub
6b24a4b7 664 $term
6b24a4b7
SF
665 $usercontext
666 $warnLevel
6b24a4b7
SF
667);
668
0b83f3d9 669our (
2ef1dcdb 670 @cmdfhs,
0b83f3d9
SF
671 $evalarg,
672 $frame,
0664c09a 673 $hist,
0b83f3d9
SF
674 $ImmediateStop,
675 $line,
676 $onetimeDump,
1ce985d2 677 %option,
0b83f3d9 678 $OUT,
1ce985d2 679 $packname,
0b83f3d9
SF
680 $signal,
681 $single,
d1450c23 682 $start,
9d0b71b3
SF
683 %sub,
684 $subname,
0b83f3d9 685 $trace,
d1450c23 686 $window,
18b5b545 687);
931ac036 688
6b24a4b7
SF
689# Used to save @ARGV and extract any debugger-related flags.
690use vars qw(@ARGS);
691
692# Used to prevent multiple entries to diesignal()
693# (if for instance diesignal() itself dies)
694use vars qw($panic);
695
696# Used to prevent the debugger from running nonstop
697# after a restart
ebd0282e 698our ($second_time);
6b24a4b7
SF
699
700sub _calc_usercontext {
701 my ($package) = @_;
702
703 # Cancel strict completely for the evaluated code, so the code
704 # the user evaluates won't be affected by it. (Shlomi Fish)
22fc883d 705 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;'
6b24a4b7
SF
706 . "package $package;"; # this won't let them modify, alas
707}
708
c1051fcf 709sub eval {
69893cff 710
c1051fcf 711 # 'my' would make it visible from user code
e22ea7cc 712 # but so does local! --tchrist
69893cff 713 # Remember: this localizes @DB::res, not @main::res.
c1051fcf
IZ
714 local @res;
715 {
e22ea7cc
RF
716
717 # Try to keep the user code from messing with us. Save these so that
718 # even if the eval'ed code changes them, we can put them back again.
719 # Needed because the user could refer directly to the debugger's
69893cff
RGS
720 # package globals (and any 'my' variables in this containing scope)
721 # inside the eval(), and we want to try to stay safe.
e22ea7cc 722 local $otrace = $trace;
69893cff
RGS
723 local $osingle = $single;
724 local $od = $^D;
725
726 # Untaint the incoming eval() argument.
727 { ($evalarg) = $evalarg =~ /(.*)/s; }
728
e22ea7cc 729 # $usercontext built in DB::DB near the comment
69893cff
RGS
730 # "set up the context for DB::eval ..."
731 # Evaluate and save any results.
e22ea7cc 732 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug
69893cff
RGS
733
734 # Restore those old values.
735 $trace = $otrace;
736 $single = $osingle;
737 $^D = $od;
c1051fcf 738 }
69893cff
RGS
739
740 # Save the current value of $@, and preserve it in the debugger's copy
741 # of the saved precious globals.
c1051fcf 742 my $at = $@;
69893cff
RGS
743
744 # Since we're only saving $@, we only have to localize the array element
745 # that it will be stored in.
e22ea7cc 746 local $saved[0]; # Preserve the old value of $@
7c54f46a 747 eval { DB::save() };
69893cff
RGS
748
749 # Now see whether we need to report an error back to the user.
c1051fcf 750 if ($at) {
69893cff
RGS
751 local $\ = '';
752 print $OUT $at;
753 }
754
755 # Display as required by the caller. $onetimeDump and $onetimedumpDepth
756 # are package globals.
757 elsif ($onetimeDump) {
e22ea7cc
RF
758 if ( $onetimeDump eq 'dump' ) {
759 local $option{dumpDepth} = $onetimedumpDepth
760 if defined $onetimedumpDepth;
761 dumpit( $OUT, \@res );
762 }
763 elsif ( $onetimeDump eq 'methods' ) {
764 methods( $res[0] );
765 }
69893cff 766 } ## end elsif ($onetimeDump)
c1051fcf 767 @res;
69893cff
RGS
768} ## end sub eval
769
770############################################## End lexical danger zone
c1051fcf 771
e22ea7cc
RF
772# After this point it is safe to introduce lexicals.
773# The code being debugged will be executing in its own context, and
69893cff 774# can't see the inside of the debugger.
d338d6fe 775#
e22ea7cc 776# However, one should not overdo it: leave as much control from outside as
69893cff
RGS
777# possible. If you make something a lexical, it's not going to be addressable
778# from outside the debugger even if you know its name.
779
d338d6fe
PP
780# This file is automatically included if you do perl -d.
781# It's probably not useful to include this yourself.
782#
e22ea7cc 783# Before venturing further into these twisty passages, it is
2f7e9187
MS
784# wise to read the perldebguts man page or risk the ire of dragons.
785#
69893cff
RGS
786# (It should be noted that perldebguts will tell you a lot about
787# the underlying mechanics of how the debugger interfaces into the
788# Perl interpreter, but not a lot about the debugger itself. The new
789# comments in this code try to address this problem.)
790
d338d6fe 791# Note that no subroutine call is possible until &DB::sub is defined
36477c24 792# (for subroutines defined outside of the package DB). In fact the same is
d338d6fe 793# true if $deep is not defined.
055fd3a9
GS
794
795# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich)
055fd3a9
GS
796
797# modified Perl debugger, to be run from Emacs in perldb-mode
798# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990
799# Johan Vromans -- upgrade to 4.0 pl 10
800# Ilya Zakharevich -- patches after 5.001 (and some before ;-)
6fae1ad7 801########################################################################
d338d6fe 802
69893cff
RGS
803=head1 DEBUGGER INITIALIZATION
804
805The debugger starts up in phases.
806
807=head2 BASIC SETUP
808
809First, it initializes the environment it wants to run in: turning off
810warnings during its own compilation, defining variables which it will need
811to avoid warnings later, setting itself up to not exit when the program
812terminates, and defaulting to printing return values for the C<r> command.
813
814=cut
815
eda6e075 816# Needed for the statement after exec():
69893cff
RGS
817#
818# This BEGIN block is simply used to switch off warnings during debugger
98dc9551 819# compilation. Probably it would be better practice to fix the warnings,
69893cff 820# but this is how it's done at the moment.
eda6e075 821
e22ea7cc
RF
822BEGIN {
823 $ini_warn = $^W;
824 $^W = 0;
825} # Switch compilation warnings off until another BEGIN.
d12a4851 826
69893cff
RGS
827local ($^W) = 0; # Switch run-time warnings off during init.
828
2cbb2ee1
RGS
829=head2 THREADS SUPPORT
830
831If we are running under a threaded Perl, we require threads and threads::shared
832if the environment variable C<PERL5DB_THREADED> is set, to enable proper
833threaded debugger control. C<-dt> can also be used to set this.
834
835Each new thread will be announced and the debugger prompt will always inform
836you of each new thread created. It will also indicate the thread id in which
837we are currently running within the prompt like this:
838
2dbd01ad 839 [tid] DB<$i>
2cbb2ee1
RGS
840
841Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger
842command prompt. The prompt will show: C<[0]> when running under threads, but
843not actually in a thread. C<[tid]> is consistent with C<gdb> usage.
844
845While running under threads, when you set or delete a breakpoint (etc.), this
b570d64b 846will apply to all threads, not just the currently running one. When you are
2cbb2ee1
RGS
847in a currently executing thread, you will stay there until it completes. With
848the current implementation it is not currently possible to hop from one thread
849to another.
850
851The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>.
852
853Note that threading support was built into the debugger as of Perl version
854C<5.8.6> and debugger version C<1.2.8>.
855
856=cut
857
858BEGIN {
2dbd01ad
SF
859 # ensure we can share our non-threaded variables or no-op
860 if ($ENV{PERL5DB_THREADED}) {
861 require threads;
862 require threads::shared;
863 import threads::shared qw(share);
864 $DBGR;
865 share(\$DBGR);
866 lock($DBGR);
867 print "Threads support enabled\n";
868 } else {
869 *lock = sub(*) {};
870 *share = sub(*) {};
871 }
2cbb2ee1
RGS
872}
873
2218c045
SF
874# These variables control the execution of 'dumpvar.pl'.
875{
876 package dumpvar;
877 use vars qw(
878 $hashDepth
879 $arrayDepth
880 $dumpDBFiles
881 $dumpPackages
882 $quoteHighBit
883 $printUndef
884 $globPrint
885 $usageOnly
886 );
887}
69893cff 888
2218c045
SF
889# used to control die() reporting in diesignal()
890{
891 package Carp;
892 use vars qw($CarpLevel);
893}
d338d6fe 894
422c59bf 895# without threads, $filename is not defined until DB::DB is called
2cbb2ee1 896foreach my $k (keys (%INC)) {
2dbd01ad 897 share(\$main::{'_<'.$filename}) if defined $filename;
2cbb2ee1
RGS
898};
899
54d04a52 900# Command-line + PERLLIB:
69893cff 901# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
902@ini_INC = @INC;
903
69893cff
RGS
904# This was an attempt to clear out the previous values of various
905# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
906# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
907
69893cff
RGS
908# We set these variables to safe values. We don't want to blindly turn
909# off warnings, because other packages may still want them.
e22ea7cc
RF
910$trace = $signal = $single = 0; # Uninitialized warning suppression
911 # (local $^W cannot help - other packages!).
69893cff
RGS
912
913# Default to not exiting when program finishes; print the return
914# value when the 'r' command is used to return from a subroutine.
55497cff 915$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 916
6b24a4b7
SF
917use vars qw($trace_to_depth);
918
5e2b42dd
SF
919# Default to 1E9 so it won't be limited to a certain recursion depth.
920$trace_to_depth = 1E9;
bdba49ad 921
69893cff
RGS
922=head1 OPTION PROCESSING
923
b570d64b
SF
924The debugger's options are actually spread out over the debugger itself and
925C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
926subs to be called with a value. To try to make this a little easier to
927manage, the debugger uses a few data structures to define what options
928are legal and how they are to be processed.
929
930First, the C<@options> array defines the I<names> of all the options that
931are to be accepted.
932
933=cut
934
935@options = qw(
5561b870 936 CommandSet HistFile HistSize
e22ea7cc
RF
937 hashDepth arrayDepth dumpDepth
938 DumpDBFiles DumpPackages DumpReused
939 compactDump veryCompact quote
940 HighBit undefPrint globPrint
941 PrintRet UsageOnly frame
942 AutoTrace TTY noTTY
943 ReadLine NonStop LineInfo
944 maxTraceLen recallCommand ShellBang
945 pager tkRunning ornaments
946 signalLevel warnLevel dieLevel
947 inhibit_exit ImmediateStop bareStringify
948 CreateTTY RemotePort windowSize
584420f0 949 DollarCaretP
e22ea7cc 950);
d12a4851 951
584420f0 952@RememberOnROptions = qw(DollarCaretP);
d12a4851 953
69893cff
RGS
954=pod
955
956Second, C<optionVars> lists the variables that each option uses to save its
957state.
958
959=cut
960
6b24a4b7
SF
961use vars qw(%optionVars);
962
69893cff 963%optionVars = (
e22ea7cc
RF
964 hashDepth => \$dumpvar::hashDepth,
965 arrayDepth => \$dumpvar::arrayDepth,
966 CommandSet => \$CommandSet,
967 DumpDBFiles => \$dumpvar::dumpDBFiles,
968 DumpPackages => \$dumpvar::dumpPackages,
969 DumpReused => \$dumpvar::dumpReused,
970 HighBit => \$dumpvar::quoteHighBit,
971 undefPrint => \$dumpvar::printUndef,
972 globPrint => \$dumpvar::globPrint,
973 UsageOnly => \$dumpvar::usageOnly,
974 CreateTTY => \$CreateTTY,
975 bareStringify => \$dumpvar::bareStringify,
976 frame => \$frame,
977 AutoTrace => \$trace,
978 inhibit_exit => \$inhibit_exit,
979 maxTraceLen => \$maxtrace,
980 ImmediateStop => \$ImmediateStop,
981 RemotePort => \$remoteport,
982 windowSize => \$window,
5561b870
AK
983 HistFile => \$histfile,
984 HistSize => \$histsize,
69893cff
RGS
985);
986
987=pod
988
989Third, C<%optionAction> defines the subroutine to be called to process each
990option.
991
b570d64b 992=cut
69893cff 993
6b24a4b7
SF
994use vars qw(%optionAction);
995
69893cff
RGS
996%optionAction = (
997 compactDump => \&dumpvar::compactDump,
998 veryCompact => \&dumpvar::veryCompact,
999 quote => \&dumpvar::quote,
1000 TTY => \&TTY,
1001 noTTY => \&noTTY,
1002 ReadLine => \&ReadLine,
1003 NonStop => \&NonStop,
1004 LineInfo => \&LineInfo,
1005 recallCommand => \&recallCommand,
1006 ShellBang => \&shellBang,
1007 pager => \&pager,
1008 signalLevel => \&signalLevel,
1009 warnLevel => \&warnLevel,
1010 dieLevel => \&dieLevel,
1011 tkRunning => \&tkRunning,
1012 ornaments => \&ornaments,
1013 RemotePort => \&RemotePort,
1014 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1015);
1016
69893cff
RGS
1017=pod
1018
1019Last, the C<%optionRequire> notes modules that must be C<require>d if an
1020option is used.
1021
1022=cut
d338d6fe 1023
69893cff
RGS
1024# Note that this list is not complete: several options not listed here
1025# actually require that dumpvar.pl be loaded for them to work, but are
1026# not in the table. A subsequent patch will correct this problem; for
1027# the moment, we're just recommenting, and we are NOT going to change
1028# function.
6b24a4b7
SF
1029use vars qw(%optionRequire);
1030
eda6e075 1031%optionRequire = (
69893cff
RGS
1032 compactDump => 'dumpvar.pl',
1033 veryCompact => 'dumpvar.pl',
1034 quote => 'dumpvar.pl',
e22ea7cc 1035);
69893cff
RGS
1036
1037=pod
1038
1039There are a number of initialization-related variables which can be set
1040by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1041variable. These are:
1042
1043=over 4
1044
1045=item C<$rl> - readline control XXX needs more explanation
1046
1047=item C<$warnLevel> - whether or not debugger takes over warning handling
1048
1049=item C<$dieLevel> - whether or not debugger takes over die handling
1050
1051=item C<$signalLevel> - whether or not debugger takes over signal handling
1052
1053=item C<$pre> - preprompt actions (array reference)
1054
1055=item C<$post> - postprompt actions (array reference)
1056
1057=item C<$pretype>
1058
1059=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1060
1061=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1062
1063=back
1064
1065=cut
d338d6fe
PP
1066
1067# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1068$rl = 1 unless defined $rl;
1069$warnLevel = 1 unless defined $warnLevel;
1070$dieLevel = 1 unless defined $dieLevel;
1071$signalLevel = 1 unless defined $signalLevel;
1072$pre = [] unless defined $pre;
1073$post = [] unless defined $post;
1074$pretype = [] unless defined $pretype;
1075$CreateTTY = 3 unless defined $CreateTTY;
1076$CommandSet = '580' unless defined $CommandSet;
1077
2cbb2ee1
RGS
1078share($rl);
1079share($warnLevel);
1080share($dieLevel);
1081share($signalLevel);
1082share($pre);
1083share($post);
1084share($pretype);
1085share($rl);
1086share($CreateTTY);
1087share($CommandSet);
1088
69893cff
RGS
1089=pod
1090
1091The default C<die>, C<warn>, and C<signal> handlers are set up.
1092
1093=cut
055fd3a9 1094
d338d6fe
PP
1095warnLevel($warnLevel);
1096dieLevel($dieLevel);
1097signalLevel($signalLevel);
055fd3a9 1098
69893cff
RGS
1099=pod
1100
1101The pager to be used is needed next. We try to get it from the
5561b870 1102environment first. If it's not defined there, we try to find it in
69893cff
RGS
1103the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1104then call the C<pager()> function to save the pager name.
1105
1106=cut
1107
1108# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1109pager(
e22ea7cc 1110
69893cff 1111 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1112 defined $ENV{PAGER}
1113 ? $ENV{PAGER}
69893cff
RGS
1114
1115 # If not, see if Config.pm defines it.
e22ea7cc
RF
1116 : eval { require Config }
1117 && defined $Config::Config{pager}
1118 ? $Config::Config{pager}
69893cff
RGS
1119
1120 # If not, fall back to 'more'.
e22ea7cc
RF
1121 : 'more'
1122 )
1123 unless defined $pager;
69893cff
RGS
1124
1125=pod
1126
1127We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1128recall character (C<!> unless otherwise defined) and the shell escape
1129character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1130neither works in the debugger at the moment.
1131
1132=cut
1133
055fd3a9 1134setman();
69893cff
RGS
1135
1136# Set up defaults for command recall and shell escape (note:
1137# these currently don't work in linemode debugging).
2218c045
SF
1138recallCommand("!") unless defined $prc;
1139shellBang("!") unless defined $psh;
69893cff
RGS
1140
1141=pod
1142
1143We then set up the gigantic string containing the debugger help.
1144We also set the limit on the number of arguments we'll display during a
1145trace.
1146
1147=cut
1148
04e43a21 1149sethelp();
69893cff
RGS
1150
1151# If we didn't get a default for the length of eval/stack trace args,
1152# set it here.
1d06cb2d 1153$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1154
1155=head2 SETTING UP THE DEBUGGER GREETING
1156
be9a9b1d 1157The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1158running, and whether the current debugger is the primary or a child.
1159
1160If we are the primary, we just hang onto our pid so we'll have it when
1161or if we start a child debugger. If we are a child, we'll set things up
1162so we'll have a unique greeting and so the parent will give us our own
1163TTY later.
1164
1165We save the current contents of the C<PERLDB_PIDS> environment variable
1166because we mess around with it. We'll also need to hang onto it because
1167we'll need it if we restart.
1168
1169Child debuggers make a label out of the current PID structure recorded in
1170PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1171yet so the parent will give them one later via C<resetterm()>.
1172
1173=cut
1174
e22ea7cc 1175# Save the current contents of the environment; we're about to
69893cff 1176# much with it. We'll need this if we have to restart.
6b24a4b7 1177use vars qw($ini_pids);
f1583d8f 1178$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1179
6b24a4b7
SF
1180use vars qw ($pids $term_pid);
1181
e22ea7cc
RF
1182if ( defined $ENV{PERLDB_PIDS} ) {
1183
69893cff 1184 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1185 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1186 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1187
1188 my $env_pids = $ENV{PERLDB_PIDS};
1189 $pids = "[$env_pids]";
1190
1191 # Unless we are on OpenVMS, all programs under the DCL shell run under
1192 # the same PID.
1193
1194 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1195 $term_pid = $$;
1196 }
1197 else {
1198 $ENV{PERLDB_PIDS} .= "->$$";
1199 $term_pid = -1;
1200 }
1201
69893cff
RGS
1202} ## end if (defined $ENV{PERLDB_PIDS...
1203else {
e22ea7cc
RF
1204
1205 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1206 # child debugger, and mark us as the parent, so we'll know to set up
1207 # more TTY's is we have to.
1208 $ENV{PERLDB_PIDS} = "$$";
619a0444 1209 $pids = "[pid=$$]";
e22ea7cc 1210 $term_pid = $$;
f1583d8f 1211}
69893cff 1212
6b24a4b7 1213use vars qw($pidprompt);
f1583d8f 1214$pidprompt = '';
69893cff
RGS
1215
1216# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1217our ($slave_editor);
69893cff
RGS
1218*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1219
1220=head2 READING THE RC FILE
1221
b570d64b 1222The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1223running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1224
b570d64b 1225=cut
69893cff
RGS
1226
1227# As noted, this test really doesn't check accurately that the debugger
1228# is running at a terminal or not.
d338d6fe 1229
6b24a4b7 1230use vars qw($rcfile);
fb4d8a6c
SF
1231{
1232 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1233 # this is the wrong metric!
1234 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1235}
1236
69893cff
RGS
1237=pod
1238
1239The debugger does a safety test of the file to be read. It must be owned
1240either by the current user or root, and must only be writable by the owner.
1241
1242=cut
1243
1244# This wraps a safety test around "do" to read and evaluate the init file.
1245#
055fd3a9
GS
1246# This isn't really safe, because there's a race
1247# between checking and opening. The solution is to
1248# open and fstat the handle, but then you have to read and
1249# eval the contents. But then the silly thing gets
69893cff
RGS
1250# your lexical scope, which is unfortunate at best.
1251sub safe_do {
055fd3a9
GS
1252 my $file = shift;
1253
1254 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1255 local $SIG{__WARN__};
1256 local $SIG{__DIE__};
055fd3a9 1257
e22ea7cc 1258 unless ( is_safe_file($file) ) {
69893cff 1259 CORE::warn <<EO_GRIPE;
055fd3a9 1260perldb: Must not source insecure rcfile $file.
b570d64b 1261 You or the superuser must be the owner, and it must not
69893cff 1262 be writable by anyone but its owner.
055fd3a9 1263EO_GRIPE
69893cff
RGS
1264 return;
1265 } ## end unless (is_safe_file($file...
055fd3a9
GS
1266
1267 do $file;
1268 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1269} ## end sub safe_do
055fd3a9 1270
69893cff
RGS
1271# This is the safety test itself.
1272#
055fd3a9
GS
1273# Verifies that owner is either real user or superuser and that no
1274# one but owner may write to it. This function is of limited use
1275# when called on a path instead of upon a handle, because there are
1276# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1277# eventually accessed is the same as the one tested.
055fd3a9
GS
1278# Assumes that the file's existence is not in doubt.
1279sub is_safe_file {
1280 my $path = shift;
69893cff 1281 stat($path) || return; # mysteriously vaporized
e22ea7cc 1282 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1283
1284 return 0 if $uid != 0 && $uid != $<;
1285 return 0 if $mode & 022;
1286 return 1;
69893cff 1287} ## end sub is_safe_file
055fd3a9 1288
69893cff 1289# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1290# exists, we safely do it.
1291if ( -f $rcfile ) {
055fd3a9 1292 safe_do("./$rcfile");
69893cff 1293}
e22ea7cc 1294
69893cff 1295# If there isn't one here, try the user's home directory.
e22ea7cc 1296elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1297 safe_do("$ENV{HOME}/$rcfile");
1298}
e22ea7cc 1299
69893cff 1300# Else try the login directory.
e22ea7cc 1301elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1302 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1303}
1304
69893cff 1305# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1306if ( defined $ENV{PERLDB_OPTS} ) {
1307 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1308}
1309
69893cff
RGS
1310=pod
1311
1312The last thing we do during initialization is determine which subroutine is
1313to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1314the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1315(darwin).
69893cff
RGS
1316
1317=cut
1318
1319# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1320# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1321# OS/2, or on Mac OS X. This may need some expansion.
1322
1323if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1324{
b570d64b 1325 if ( defined $remoteport ) {
11653f7f
JJ
1326 # Expect an inetd-like server
1327 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1328 }
1329 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1330 # of terminal this is,
1331 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1332 and defined $ENV{DISPLAY} # and what display it's on,
1333 )
1334 {
1335 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1336 }
1337 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1338 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1339 }
1340 elsif ( $^O eq 'darwin' # If this is Mac OS X
1341 and defined $ENV{TERM_PROGRAM} # and we're running inside
1342 and $ENV{TERM_PROGRAM}
1343 eq 'Apple_Terminal' # Terminal.app
1344 )
1345 {
1346 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1347 }
69893cff 1348} ## end if (not defined &get_fork_TTY...
e22ea7cc 1349
dbb46cec
DQ
1350# untaint $^O, which may have been tainted by the last statement.
1351# see bug [perl #24674]
e22ea7cc
RF
1352$^O =~ m/^(.*)\z/;
1353$^O = $1;
f1583d8f 1354
d12a4851 1355# Here begin the unreadable code. It needs fixing.
055fd3a9 1356
69893cff
RGS
1357=head2 RESTART PROCESSING
1358
1359This section handles the restart command. When the C<R> command is invoked, it
1360tries to capture all of the state it can into environment variables, and
1361then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1362if C<PERLDB_RESTART> is there; if so, we reload all the information that
1363the R command stuffed into the environment variables.
1364
b570d64b 1365 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1366 PERLDB_HIST - command history, if it's available
1367 PERLDB_ON_LOAD - breakpoints set by the rc file
1368 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1369 PERLDB_VISITED - files that had breakpoints
1370 PERLDB_FILE_... - breakpoints for a file
1371 PERLDB_OPT - active options
1372 PERLDB_INC - the original @INC
1373 PERLDB_PRETYPE - preprompt debugger actions
1374 PERLDB_PRE - preprompt Perl code
1375 PERLDB_POST - post-prompt Perl code
1376 PERLDB_TYPEAHEAD - typeahead captured by readline()
1377
1378We chug through all these variables and plug the values saved in them
1379back into the appropriate spots in the debugger.
1380
1381=cut
1382
0664c09a 1383use vars qw(%postponed_file @typeahead);
14f38b27 1384
0664c09a 1385our (@hist, @truehist);
6b24a4b7 1386
fb0fb5f4
SF
1387sub _restore_shared_globals_after_restart
1388{
1389 @hist = get_list('PERLDB_HIST');
1390 %break_on_load = get_list("PERLDB_ON_LOAD");
1391 %postponed = get_list("PERLDB_POSTPONE");
1392
1393 share(@hist);
1394 share(@truehist);
1395 share(%break_on_load);
1396 share(%postponed);
1397}
1398
e18a02a6 1399sub _restore_breakpoints_and_actions {
e22ea7cc 1400
e22ea7cc 1401 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1402
bdba49ad
SF
1403 for my $file_idx ( 0 .. $#had_breakpoints ) {
1404 my $filename = $had_breakpoints[$file_idx];
1405 my %pf = get_list("PERLDB_FILE_$file_idx");
1406 $postponed_file{ $filename } = \%pf if %pf;
1407 my @lines = sort {$a <=> $b} keys(%pf);
1408 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1409 for my $line_idx (0 .. $#lines) {
1410 _set_breakpoint_enabled_status(
1411 $filename,
1412 $lines[$line_idx],
1413 ($enabled_statuses[$line_idx] ? 1 : ''),
1414 );
1415 }
e22ea7cc 1416 }
69893cff 1417
e18a02a6
SF
1418 return;
1419}
1420
ca50076b
SF
1421sub _restore_options_after_restart
1422{
1423 my %options_map = get_list("PERLDB_OPT");
1424
1425 while ( my ( $opt, $val ) = each %options_map ) {
1426 $val =~ s/[\\\']/\\$1/g;
1427 parse_options("$opt'$val'");
1428 }
1429
1430 return;
1431}
1432
18580168
SF
1433sub _restore_globals_after_restart
1434{
1435 # restore original @INC
1436 @INC = get_list("PERLDB_INC");
1437 @ini_INC = @INC;
1438
1439 # return pre/postprompt actions and typeahead buffer
1440 $pretype = [ get_list("PERLDB_PRETYPE") ];
1441 $pre = [ get_list("PERLDB_PRE") ];
1442 $post = [ get_list("PERLDB_POST") ];
1443 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1444
1445 return;
1446}
1447
fb0fb5f4 1448
e18a02a6
SF
1449if ( exists $ENV{PERLDB_RESTART} ) {
1450
1451 # We're restarting, so we don't need the flag that says to restart anymore.
1452 delete $ENV{PERLDB_RESTART};
1453
1454 # $restart = 1;
fb0fb5f4 1455 _restore_shared_globals_after_restart();
e18a02a6
SF
1456
1457 _restore_breakpoints_and_actions();
1458
69893cff 1459 # restore options
ca50076b 1460 _restore_options_after_restart();
69893cff 1461
18580168 1462 _restore_globals_after_restart();
69893cff
RGS
1463} ## end if (exists $ENV{PERLDB_RESTART...
1464
1465=head2 SETTING UP THE TERMINAL
1466
1467Now, we'll decide how the debugger is going to interact with the user.
1468If there's no TTY, we set the debugger to run non-stop; there's not going
1469to be anyone there to enter commands.
1470
1471=cut
54d04a52 1472
ebd0282e 1473use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1474use vars qw($lineinfo $doccmd);
1475
ebd0282e
SF
1476our ($runnonstop);
1477
d338d6fe 1478if ($notty) {
69893cff 1479 $runnonstop = 1;
2dbd01ad 1480 share($runnonstop);
69893cff 1481}
d12a4851 1482
69893cff
RGS
1483=pod
1484
1485If there is a TTY, we have to determine who it belongs to before we can
1486proceed. If this is a slave editor or graphical debugger (denoted by
1487the first command-line switch being '-emacs'), we shift this off and
1488set C<$rl> to 0 (XXX ostensibly to do straight reads).
1489
1490=cut
1491
1492else {
e22ea7cc 1493
69893cff
RGS
1494 # Is Perl being run from a slave editor or graphical debugger?
1495 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1496 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1497 $rl = 0;
1498 shift(@main::ARGV);
1499 }
e22ea7cc
RF
1500
1501 #require Term::ReadLine;
d12a4851 1502
69893cff
RGS
1503=pod
1504
1505We then determine what the console should be on various systems:
1506
1507=over 4
1508
1509=item * Cygwin - We use C<stdin> instead of a separate device.
1510
1511=cut
1512
e22ea7cc
RF
1513 if ( $^O eq 'cygwin' ) {
1514
69893cff
RGS
1515 # /dev/tty is binary. use stdin for textmode
1516 undef $console;
1517 }
1518
1519=item * Unix - use C</dev/tty>.
1520
1521=cut
1522
e22ea7cc 1523 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1524 $console = "/dev/tty";
1525 }
1526
1527=item * Windows or MSDOS - use C<con>.
1528
1529=cut
1530
e22ea7cc 1531 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1532 $console = "con";
1533 }
1534
69893cff
RGS
1535=item * VMS - use C<sys$command>.
1536
1537=cut
1538
1539 else {
e22ea7cc 1540
69893cff
RGS
1541 # everything else is ...
1542 $console = "sys\$command";
d12a4851 1543 }
69893cff
RGS
1544
1545=pod
1546
1547=back
1548
1549Several other systems don't use a specific console. We C<undef $console>
1550for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1551with a slave editor, Epoc).
1552
1553=cut
d12a4851 1554
e22ea7cc
RF
1555 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1556
69893cff 1557 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1558 $console = undef;
1559 }
1560
1561 if ( $^O eq 'NetWare' ) {
d12a4851 1562
69893cff
RGS
1563 # /dev/tty is binary. use stdin for textmode
1564 $console = undef;
1565 }
d12a4851 1566
69893cff
RGS
1567 # In OS/2, we need to use STDIN to get textmode too, even though
1568 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1569 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1570 { # In OS/2
1571 $console = undef;
1572 }
1573
1574 # EPOC also falls into the 'got to use STDIN' camp.
1575 if ( $^O eq 'epoc' ) {
1576 $console = undef;
1577 }
d12a4851 1578
69893cff
RGS
1579=pod
1580
1581If there is a TTY hanging around from a parent, we use that as the console.
1582
1583=cut
1584
e22ea7cc 1585 $console = $tty if defined $tty;
d12a4851 1586
b570d64b 1587=head2 SOCKET HANDLING
69893cff
RGS
1588
1589The debugger is capable of opening a socket and carrying out a debugging
1590session over the socket.
1591
1592If C<RemotePort> was defined in the options, the debugger assumes that it
1593should try to start a debugging session on that port. It builds the socket
1594and then tries to connect the input and output filehandles to it.
1595
1596=cut
1597
1598 # Handle socket stuff.
e22ea7cc
RF
1599
1600 if ( defined $remoteport ) {
1601
69893cff
RGS
1602 # If RemotePort was defined in the options, connect input and output
1603 # to the socket.
11653f7f 1604 $IN = $OUT = connect_remoteport();
69893cff
RGS
1605 } ## end if (defined $remoteport)
1606
1607=pod
1608
1609If no C<RemotePort> was defined, and we want to create a TTY on startup,
1610this is probably a situation where multiple debuggers are running (for example,
1611a backticked command that starts up another debugger). We create a new IN and
1612OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1613and if we can.
1614
1615=cut
1616
1617 # Non-socket.
1618 else {
e22ea7cc 1619
69893cff
RGS
1620 # Two debuggers running (probably a system or a backtick that invokes
1621 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1622 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1623 # know how, and we can.
e22ea7cc
RF
1624 create_IN_OUT(4) if $CreateTTY & 4;
1625 if ($console) {
1626
69893cff 1627 # If we have a console, check to see if there are separate ins and
cd1191f1 1628 # outs to open. (They are assumed identical if not.)
69893cff 1629
e22ea7cc
RF
1630 my ( $i, $o ) = split /,/, $console;
1631 $o = $i unless defined $o;
69893cff 1632
69893cff 1633 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1634 open( IN, "+<$i" )
1635 || open( IN, "<$i" )
1636 || open( IN, "<&STDIN" );
1637
69893cff
RGS
1638 # read/write/create/clobber out, or write/create/clobber out,
1639 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1640 open( OUT, "+>$o" )
1641 || open( OUT, ">$o" )
1642 || open( OUT, ">&STDERR" )
1643 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1644
1645 } ## end if ($console)
1646 elsif ( not defined $console ) {
1647
1648 # No console. Open STDIN.
1649 open( IN, "<&STDIN" );
1650
1651 # merge with STDERR, or with STDOUT.
1652 open( OUT, ">&STDERR" )
1653 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1654 $console = 'STDIN/OUT';
69893cff
RGS
1655 } ## end elsif (not defined $console)
1656
1657 # Keep copies of the filehandles so that when the pager runs, it
1658 # can close standard input without clobbering ours.
2b0b9dd1
SF
1659 if ($console or (not defined($console))) {
1660 $IN = \*IN;
1661 $OUT = \*OUT;
1662 }
e22ea7cc
RF
1663 } ## end elsif (from if(defined $remoteport))
1664
1665 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1666 $OUT->autoflush(1);
e22ea7cc
RF
1667
1668 # Line info goes to debugger output unless pointed elsewhere.
1669 # Pointing elsewhere makes it possible for slave editors to
1670 # keep track of file and position. We have both a filehandle
1671 # and a I/O description to keep track of.
1672 $LINEINFO = $OUT unless defined $LINEINFO;
1673 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1674 # share($LINEINFO); # <- unable to share globs
1675 share($lineinfo); #
e22ea7cc 1676
69893cff
RGS
1677=pod
1678
1679To finish initialization, we show the debugger greeting,
1680and then call the C<afterinit()> subroutine if there is one.
1681
1682=cut
d12a4851 1683
e22ea7cc
RF
1684 # Show the debugger greeting.
1685 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1686 unless ($runnonstop) {
1687 local $\ = '';
1688 local $, = '';
1689 if ( $term_pid eq '-1' ) {
1690 print $OUT "\nDaughter DB session started...\n";
1691 }
1692 else {
1693 print $OUT "\nLoading DB routines from $header\n";
1694 print $OUT (
1695 "Editor support ",
1696 $slave_editor ? "enabled" : "available", ".\n"
1697 );
1698 print $OUT
1f874cb6 1699"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1700 } ## end else [ if ($term_pid eq '-1')
1701 } ## end unless ($runnonstop)
1702} ## end else [ if ($notty)
1703
1704# XXX This looks like a bug to me.
1705# Why copy to @ARGS and then futz with @args?
d338d6fe 1706@ARGS = @ARGV;
6b24a4b7 1707# for (@args) {
69893cff
RGS
1708 # Make sure backslashes before single quotes are stripped out, and
1709 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1710 # s/\'/\\\'/g; # removed while not justified understandably
1711 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1712# }
d338d6fe 1713
e22ea7cc 1714# If there was an afterinit() sub defined, call it. It will get
69893cff 1715# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1716if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1717 afterinit();
d338d6fe 1718}
e22ea7cc 1719
69893cff 1720# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1721use vars qw($I_m_init);
1722
43aed9ee
IZ
1723$I_m_init = 1;
1724
d338d6fe
PP
1725############################################################ Subroutines
1726
69893cff
RGS
1727=head1 SUBROUTINES
1728
1729=head2 DB
1730
1731This gigantic subroutine is the heart of the debugger. Called before every
1732statement, its job is to determine if a breakpoint has been reached, and
1733stop if so; read commands from the user, parse them, and execute
b468dcb6 1734them, and then send execution off to the next statement.
69893cff
RGS
1735
1736Note that the order in which the commands are processed is very important;
1737some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1738to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1739but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1740see what's happening in any given command.
1741
1742=cut
1743
136ae23d
SF
1744# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1745
6b24a4b7
SF
1746use vars qw(
1747 $action
6b24a4b7 1748 $cmd
6b24a4b7
SF
1749 $fall_off_end
1750 $file
1751 $filename_ini
1752 $finished
1753 %had_breakpoints
6b24a4b7
SF
1754 $level
1755 $max
6b24a4b7 1756 $package
6b24a4b7 1757 $sh
6b24a4b7
SF
1758 $try
1759);
1760
1ce985d2 1761our (
bdb3f37d 1762 %alias,
1ce985d2 1763 $doret,
0664c09a 1764 $end,
d1450c23 1765 $incr,
73c5e526 1766 $laststep,
14f38b27 1767 $rc,
1ce985d2
SF
1768 $stack_depth,
1769 @stack,
1770 @to_watch,
1771 @old_watch,
1772);
8ad70697 1773
6791e41b
SF
1774sub _DB__determine_if_we_should_break
1775{
1776 # if we have something here, see if we should break.
1777 # $stop is lexical and local to this block - $action on the other hand
1778 # is global.
1779 my $stop;
1780
1781 if ( $dbline{$line}
1782 && _is_breakpoint_enabled($filename, $line)
1783 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1784 {
1785
1786 # Stop if the stop criterion says to just stop.
1787 if ( $stop eq '1' ) {
1788 $signal |= 1;
1789 }
1790
1791 # It's a conditional stop; eval it in the user's context and
1792 # see if we should stop. If so, remove the one-time sigil.
1793 elsif ($stop) {
1794 $evalarg = "\$DB::signal |= 1 if do {$stop}";
6cff0f90 1795 DB::eval();
6791e41b
SF
1796 # If the breakpoint is temporary, then delete its enabled status.
1797 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1798 _cancel_breakpoint_temp_enabled_status($filename, $line);
1799 }
1800 }
1801 } ## end if ($dbline{$line} && ...
1802}
1803
8481f647
SF
1804sub _DB__is_finished {
1805 if ($finished and $level <= 1) {
1806 end_report();
1807 return 1;
1808 }
1809 else {
1810 return;
1811 }
1812}
1813
32bbadc6
SF
1814sub _DB__read_next_cmd
1815{
1816 my ($tid) = @_;
1817
1818 # We have a terminal, or can get one ...
1819 if (!$term) {
1820 setterm();
1821 }
1822
1823 # ... and it belogs to this PID or we get one for this PID ...
1824 if ($term_pid != $$) {
1825 resetterm(1);
1826 }
1827
1828 # ... and we got a line of command input ...
1829 $cmd = DB::readline(
1830 "$pidprompt $tid DB"
1831 . ( '<' x $level )
1832 . ( $#hist + 1 )
1833 . ( '>' x $level ) . " "
1834 );
1835
1836 return defined($cmd);
1837}
1838
7013f40c
SF
1839sub _DB__trim_command_and_return_first_component {
1840 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1841 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1842
1843 $cmd =~ m{\A(\S*)};
1844 return $1;
1845}
1846
2a802473
SF
1847sub _DB__handle_f_command {
1848 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
1849 $file =~ s/\s+$//;
1850
1851 # help for no arguments (old-style was return from sub).
1852 if ( !$file ) {
1853 print $OUT
1854 "The old f command is now the r command.\n"; # hint
1855 print $OUT "The new f command switches filenames.\n";
1856 next CMD;
1857 } ## end if (!$file)
1858
1859 # if not in magic file list, try a close match.
1860 if ( !defined $main::{ '_<' . $file } ) {
1861 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1862 {
1863 $try = substr( $try, 2 );
1864 print $OUT "Choosing $try matching '$file':\n";
1865 $file = $try;
1866 }
1867 } ## end if (($try) = grep(m#^_<.*$file#...
1868 } ## end if (!defined $main::{ ...
1869
1870 # If not successfully switched now, we failed.
1871 if ( !defined $main::{ '_<' . $file } ) {
1872 print $OUT "No file matching '$file' is loaded.\n";
1873 next CMD;
1874 }
1875
1876 # We switched, so switch the debugger internals around.
1877 elsif ( $file ne $filename ) {
1878 *dbline = $main::{ '_<' . $file };
1879 $max = $#dbline;
1880 $filename = $file;
1881 $start = 1;
1882 $cmd = "l";
1883 } ## end elsif ($file ne $filename)
1884
1885 # We didn't switch; say we didn't.
1886 else {
1887 print $OUT "Already in $file.\n";
1888 next CMD;
1889 }
1890 }
1891
1892 return;
1893}
1894
6115a173
SF
1895sub _DB__handle_dot_command {
1896 my ($obj) = @_;
1897
1898 # . command.
1899 if ($cmd eq '.') {
1900 $incr = -1; # stay at current line
1901
1902 # Reset everything to the old location.
1903 $start = $line;
1904 $filename = $filename_ini;
1905 *dbline = $main::{ '_<' . $filename };
1906 $max = $#dbline;
1907
1908 # Now where are we?
1909 print_lineinfo($obj->position());
1910 next CMD;
1911 }
1912
1913 return;
1914}
1915
5c2b78e7
SF
1916sub _DB__handle_y_command {
1917 my ($obj) = @_;
1918
1919 if (my ($match_level, $match_vars)
1920 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
1921
1922 # See if we've got the necessary support.
84e7f475
SF
1923 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1924 my $Err = $@;
1925 DB::warn(
1926 $Err =~ /locate/
1927 ? "PadWalker module not found - please install\n"
1928 : $Err
1929 );
1930 next CMD;
1931 }
5c2b78e7
SF
1932
1933 # Load up dumpvar if we don't have it. If we can, that is.
1934 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1935 defined &main::dumpvar
1936 or print $OUT "dumpvar.pl not available.\n"
1937 and next CMD;
1938
1939 # Got all the modules we need. Find them and print them.
1940 my @vars = split( ' ', $match_vars || '' );
1941
1942 # Find the pad.
1943 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1944
1945 # Oops. Can't find it.
84e7f475
SF
1946 if (my $Err = $@) {
1947 $Err =~ s/ at .*//;
1948 DB::warn($Err);
1949 next CMD;
1950 }
5c2b78e7
SF
1951
1952 # Show the desired vars with dumplex().
1953 my $savout = select($OUT);
1954
1955 # Have dumplex dump the lexicals.
84e7f475
SF
1956 foreach my $key (sort keys %$h) {
1957 dumpvar::dumplex( $key, $h->{$key},
1958 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1959 @vars );
1960 }
5c2b78e7
SF
1961 select($savout);
1962 next CMD;
1963 }
1964}
1965
35cd713a
SF
1966sub _DB__handle_c_command {
1967 my ($obj) = @_;
1968
1969 if (my ($new_i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
1970
1971 $obj->i_cmd($new_i);
1972
1973 # Hey, show's over. The debugged program finished
1974 # executing already.
1975 next CMD if _DB__is_finished();
1976
1977 # Capture the place to put a one-time break.
1978 $subname = $obj->i_cmd;
1979
1980 # Probably not needed, since we finish an interactive
1981 # sub-session anyway...
1982 # local $filename = $filename;
1983 # local *dbline = *dbline; # XXX Would this work?!
1984 #
1985 # The above question wonders if localizing the alias
1986 # to the magic array works or not. Since it's commented
1987 # out, we'll just leave that to speculation for now.
1988
1989 # If the "subname" isn't all digits, we'll assume it
1990 # is a subroutine name, and try to find it.
1991 if ( $subname =~ /\D/ ) { # subroutine name
1992 # Qualify it to the current package unless it's
1993 # already qualified.
1994 $subname = $package . "::" . $subname
1995 unless $subname =~ /::/;
1996
1997 # find_sub will return "file:line_number" corresponding
1998 # to where the subroutine is defined; we call find_sub,
1999 # break up the return value, and assign it in one
2000 # operation.
2001 ( $file, $new_i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2002
2003 # Force the line number to be numeric.
2004 $obj->i_cmd($new_i + 0);
2005
2006 # If we got a line number, we found the sub.
2007 if ($obj->i_cmd) {
2008
2009 # Switch all the debugger's internals around so
2010 # we're actually working with that file.
2011 $filename = $file;
2012 *dbline = $main::{ '_<' . $filename };
2013
2014 # Mark that there's a breakpoint in this file.
2015 $had_breakpoints{$filename} |= 1;
2016
2017 # Scan forward to the first executable line
2018 # after the 'sub whatever' line.
2019 $max = $#dbline;
2020 my $ii = $obj->i_cmd;
2021 ++$ii while $dbline[$ii] == 0 && $ii < $max;
2022 $obj->i_cmd($ii);
2023 } ## end if ($i)
2024
2025 # We didn't find a sub by that name.
2026 else {
2027 print $OUT "Subroutine $subname not found.\n";
2028 next CMD;
2029 }
2030 } ## end if ($subname =~ /\D/)
2031
2032 # At this point, either the subname was all digits (an
2033 # absolute line-break request) or we've scanned through
2034 # the code following the definition of the sub, looking
2035 # for an executable, which we may or may not have found.
2036 #
2037 # If $i (which we set $subname from) is non-zero, we
2038 # got a request to break at some line somewhere. On
2039 # one hand, if there wasn't any real subroutine name
2040 # involved, this will be a request to break in the current
2041 # file at the specified line, so we have to check to make
2042 # sure that the line specified really is breakable.
2043 #
2044 # On the other hand, if there was a subname supplied, the
2045 # preceding block has moved us to the proper file and
2046 # location within that file, and then scanned forward
2047 # looking for the next executable line. We have to make
2048 # sure that one was found.
2049 #
2050 # On the gripping hand, we can't do anything unless the
2051 # current value of $i points to a valid breakable line.
2052 # Check that.
2053 if ($obj->i_cmd) {
2054
2055 # Breakable?
2056 if ( $dbline[$obj->i_cmd] == 0 ) {
2057 print $OUT "Line " . $obj->i_cmd . " not breakable.\n";
2058 next CMD;
2059 }
2060
2061 # Yes. Set up the one-time-break sigil.
2062 $dbline{$obj->i_cmd} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2063 _enable_breakpoint_temp_enabled_status($filename, $obj->i_cmd);
2064 } ## end if ($i)
2065
2066 # Turn off stack tracing from here up.
2067 for my $i (0 .. $stack_depth) {
2068 $stack[ $i ] &= ~1;
2069 }
2070 last CMD;
2071 }
2072
2073 return;
2074}
2075
a4d311a3
SF
2076sub _DB__handle_forward_slash_command {
2077 my ($obj) = @_;
2078
2079 # The pattern as a string.
2080 use vars qw($inpat);
2081
2082 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2083
2084 # Remove the final slash.
2085 $inpat =~ s:([^\\])/$:$1:;
2086
2087 # If the pattern isn't null ...
2088 if ( $inpat ne "" ) {
2089
2090 # Turn of warn and die procesing for a bit.
2091 local $SIG{__DIE__};
2092 local $SIG{__WARN__};
2093
2094 # Create the pattern.
2095 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2096 if ( $@ ne "" ) {
2097
2098 # Oops. Bad pattern. No biscuit.
2099 # Print the eval error and go back for more
2100 # commands.
2101 print $OUT "$@";
2102 next CMD;
2103 }
2104 $obj->pat($inpat);
2105 } ## end if ($inpat ne "")
2106
2107 # Set up to stop on wrap-around.
2108 $end = $start;
2109
2110 # Don't move off the current line.
2111 $incr = -1;
2112
2113 my $pat = $obj->pat;
2114
2115 # Done in eval so nothing breaks if the pattern
2116 # does something weird.
2117 eval
2118 {
2119 no strict q/vars/;
2120 for (;;) {
2121 # Move ahead one line.
2122 ++$start;
2123
2124 # Wrap if we pass the last line.
2125 $start = 1 if ($start > $max);
2126
2127 # Stop if we have gotten back to this line again,
2128 last if ($start == $end);
2129
2130 # A hit! (Note, though, that we are doing
2131 # case-insensitive matching. Maybe a qr//
2132 # expression would be better, so the user could
2133 # do case-sensitive matching if desired.
2134 if ($dbline[$start] =~ m/$pat/i) {
2135 if ($slave_editor) {
2136 # Handle proper escaping in the slave.
2137 print $OUT "\032\032$filename:$start:0\n";
2138 }
2139 else {
2140 # Just print the line normally.
2141 print $OUT "$start:\t",$dbline[$start],"\n";
2142 }
2143 # And quit since we found something.
2144 last;
2145 }
2146 }
2147 };
2148
2149 if ($@) {
2150 warn $@;
2151 }
2152
2153 # If we wrapped, there never was a match.
2154 if ( $start == $end ) {
2155 print {$OUT} "/$pat/: not found\n";
2156 }
2157 next CMD;
2158 }
2159
2160 return;
2161}
2162
11f0f050
SF
2163sub _DB__handle_question_mark_command {
2164 my ($obj) = @_;
2165
2166 # ? - backward pattern search.
2167 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2168
2169 # Get the pattern, remove trailing question mark.
2170 $inpat =~ s:([^\\])\?$:$1:;
2171
2172 # If we've got one ...
2173 if ( $inpat ne "" ) {
2174
2175 # Turn off die & warn handlers.
2176 local $SIG{__DIE__};
2177 local $SIG{__WARN__};
2178 eval '$inpat =~ m' . "\a$inpat\a";
2179
2180 if ( $@ ne "" ) {
2181
2182 # Ouch. Not good. Print the error.
2183 print $OUT $@;
2184 next CMD;
2185 }
2186 $obj->pat($inpat);
2187 } ## end if ($inpat ne "")
2188
2189 # Where we are now is where to stop after wraparound.
2190 $end = $start;
2191
2192 # Don't move away from this line.
2193 $incr = -1;
2194
2195 my $pat = $obj->pat;
2196 # Search inside the eval to prevent pattern badness
2197 # from killing us.
2198 eval {
2199 no strict q/vars/;
2200 for (;;) {
2201 # Back up a line.
2202 --$start;
2203
2204 # Wrap if we pass the first line.
2205
2206 $start = $max if ($start <= 0);
2207
2208 # Quit if we get back where we started,
2209 last if ($start == $end);
2210
2211 # Match?
2212 if ($dbline[$start] =~ m/$pat/i) {
2213 if ($slave_editor) {
2214 # Yep, follow slave editor requirements.
2215 print $OUT "\032\032$filename:$start:0\n";
2216 }
2217 else {
2218 # Yep, just print normally.
2219 print $OUT "$start:\t",$dbline[$start],"\n";
2220 }
2221
2222 # Found, so done.
2223 last;
2224 }
2225 }
2226 };
2227
2228 # Say we failed if the loop never found anything,
2229 if ( $start == $end ) {
2230 print {$OUT} "?$pat?: not found\n";
2231 }
2232 next CMD;
2233 }
2234
2235 return;
2236}
2237
5f166812
SF
2238sub _DB__handle_restart_and_rerun_commands {
2239 my ($obj) = @_;
2240
2241 # R - restart execution.
2242 # rerun - controlled restart execution.
2243 if (my ($cmd_cmd, $cmd_params) =
2244 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
2245 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2246
2247 # Close all non-system fds for a clean restart. A more
2248 # correct method would be to close all fds that were not
2249 # open when the process started, but this seems to be
2250 # hard. See "debugger 'R'estart and open database
2251 # connections" on p5p.
2252
2253 my $max_fd = 1024; # default if POSIX can't be loaded
2254 if (eval { require POSIX }) {
2255 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2256 }
2257
2258 if (defined $max_fd) {
2259 foreach ($^F+1 .. $max_fd-1) {
2260 next unless open FD_TO_CLOSE, "<&=$_";
2261 close(FD_TO_CLOSE);
2262 }
2263 }
2264
2265 # And run Perl again. We use exec() to keep the
2266 # PID stable (and that way $ini_pids is still valid).
2267 exec(@args) or print {$OUT} "exec failed: $!\n";
2268
2269 last CMD;
2270 }
2271
2272 return;
2273}
2274
2b0b9dd1
SF
2275sub DB {
2276
2277 # lock the debugger and get the thread id for the prompt
2278 lock($DBGR);
2279 my $tid;
2280 my $position;
2281 my ($prefix, $after, $infix);
2282 my $pat;
22fc883d 2283 my $explicit_stop;
2b0b9dd1
SF
2284
2285 if ($ENV{PERL5DB_THREADED}) {
2286 $tid = eval { "[".threads->tid."]" };
2287 }
2288
35cd713a
SF
2289 my $i;
2290
22fc883d
SF
2291 my $obj = DB::Obj->new(
2292 {
2293 position => \$position,
2294 prefix => \$prefix,
2295 after => \$after,
2296 explicit_stop => \$explicit_stop,
2297 infix => \$infix,
35cd713a 2298 i_cmd => \$i,
a4d311a3 2299 pat => \$pat,
22fc883d
SF
2300 },
2301 );
2302
2303 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2304
69893cff
RGS
2305 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2306 # The code being debugged may have altered them.
d338d6fe 2307 &save;
69893cff
RGS
2308
2309 # Since DB::DB gets called after every line, we can use caller() to
2310 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2311 # caller is returning all the extra information when called from the
69893cff 2312 # debugger.
e22ea7cc 2313 local ( $package, $filename, $line ) = caller;
6b24a4b7 2314 $filename_ini = $filename;
69893cff
RGS
2315
2316 # set up the context for DB::eval, so it can properly execute
2317 # code on behalf of the user. We add the package in so that the
2318 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2319 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2320
2321 # Create an alias to the active file magical array to simplify
2322 # the code here.
e22ea7cc 2323 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2324
69893cff 2325 # Last line in the program.
55783941 2326 $max = $#dbline;
69893cff 2327
22fc883d 2328 _DB__determine_if_we_should_break(@_);
69893cff
RGS
2329
2330 # Preserve the current stop-or-not, and see if any of the W
2331 # (watch expressions) has changed.
36477c24 2332 my $was_signal = $signal;
69893cff
RGS
2333
2334 # If we have any watch expressions ...
22fc883d 2335 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
2336
2337=head2 C<watchfunction()>
2338
2339C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2340function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2341current package, filename, and line as its parameters.
2342
b570d64b 2343The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2344debugger's context, so it has access to all of the debugger's internal
2345data structures and functions.
2346
2347C<watchfunction()> can control the debugger's actions. Any of the following
2348will cause the debugger to return control to the user's program after
2349C<watchfunction()> executes:
2350
b570d64b 2351=over 4
69893cff 2352
be9a9b1d
AT
2353=item *
2354
2355Returning a false value from the C<watchfunction()> itself.
2356
2357=item *
2358
2359Altering C<$single> to a false value.
2360
2361=item *
69893cff 2362
be9a9b1d 2363Altering C<$signal> to a false value.
69893cff 2364
be9a9b1d 2365=item *
69893cff 2366
be9a9b1d 2367Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2368check for C<watchfunction()>. This can be done with
2369
2370 $trace &= ~4;
2371
2372=back
2373
2374=cut
2375
e22ea7cc 2376 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2377 # current package, filename, and line. The function executes in
2378 # the DB:: package.
e22ea7cc
RF
2379 if ( $trace & 4 ) { # User-installed watch
2380 return
2381 if watchfunction( $package, $filename, $line )
2382 and not $single
2383 and not $was_signal
2384 and not( $trace & ~4 );
69893cff
RGS
2385 } ## end if ($trace & 4)
2386
e22ea7cc 2387 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2388 # turn off the signal now.
6027b9a3 2389 $was_signal = $signal;
69893cff
RGS
2390 $signal = 0;
2391
2392=head2 GETTING READY TO EXECUTE COMMANDS
2393
2394The debugger decides to take control if single-step mode is on, the
2395C<t> command was entered, or the user generated a signal. If the program
2396has fallen off the end, we set things up so that entering further commands
2397won't cause trouble, and we say that the program is over.
2398
2399=cut
2400
8dc67a69
SF
2401 # Make sure that we always print if asked for explicitly regardless
2402 # of $trace_to_depth .
22fc883d 2403 $explicit_stop = ($single || $was_signal);
8dc67a69 2404
69893cff
RGS
2405 # Check to see if we should grab control ($single true,
2406 # trace set appropriately, or we got a signal).
8dc67a69 2407 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2408 $obj->_DB__grab_control(@_);
69893cff
RGS
2409 } ## end if ($single || ($trace...
2410
2411=pod
2412
2413If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2414If there are any preprompt actions, execute those as well.
e219e2fb
RF
2415
2416=cut
2417
69893cff 2418 # If there's an action, do it now.
05da04df
SF
2419 if ($action) {
2420 $evalarg = $action;
2421 DB::eval();
2422 }
e219e2fb 2423
69893cff
RGS
2424 # Are we nested another level (e.g., did we evaluate a function
2425 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2426 if ( $single || $was_signal ) {
2427
69893cff 2428 # Yes, go down a level.
e22ea7cc 2429 local $level = $level + 1;
69893cff
RGS
2430
2431 # Do any pre-prompt actions.
e22ea7cc 2432 foreach $evalarg (@$pre) {
7c54f46a 2433 DB::eval();
e22ea7cc 2434 }
69893cff
RGS
2435
2436 # Complain about too much recursion if we passed the limit.
05da04df
SF
2437 if ($single & 4) {
2438 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2439 }
69893cff
RGS
2440
2441 # The line we're currently on. Set $incr to -1 to stay here
2442 # until we get a command that tells us to advance.
e22ea7cc
RF
2443 $start = $line;
2444 $incr = -1; # for backward motion.
69893cff
RGS
2445
2446 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2447 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2448
2449=head2 WHERE ARE WE?
2450
2451XXX Relocate this section?
2452
2453The debugger normally shows the line corresponding to the current line of
2454execution. Sometimes, though, we want to see the next line, or to move elsewhere
2455in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2456
be9a9b1d
AT
2457C<$incr> controls by how many lines the I<current> line should move forward
2458after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2459line shouldn't change.
2460
be9a9b1d 2461C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2462move forwards or backwards from when doing an C<L> or C<-> command.
2463
2464C<$max> tells the debugger where the last line of the current file is. It's
2465used to terminate loops most often.
2466
2467=head2 THE COMMAND LOOP
2468
2469Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2470in two parts:
2471
2472=over 4
2473
be9a9b1d
AT
2474=item *
2475
2476The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2477reads a command and then executes it.
2478
be9a9b1d
AT
2479=item *
2480
2481The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2482is wholly contained inside the C<CMD> block and only executes a command.
2483Used to handle commands running inside a pager.
2484
2485=back
2486
2487So why have two labels to restart the loop? Because sometimes, it's easier to
2488have a command I<generate> another command and then re-execute the loop to do
2489the new command. This is faster, but perhaps a bit more convoluted.
2490
2491=cut
2492
2493 # The big command dispatch loop. It keeps running until the
2494 # user yields up control again.
2495 #
2496 # If we have a terminal for input, and we get something back
2497 # from readline(), keep on processing.
6b24a4b7
SF
2498 my $piped;
2499 my $selected;
2500
e22ea7cc 2501 CMD:
32bbadc6 2502 while (_DB__read_next_cmd($tid))
69893cff 2503 {
e22ea7cc 2504
8380a245 2505 share($cmd);
69893cff
RGS
2506 # ... try to execute the input as debugger commands.
2507
2508 # Don't stop running.
2509 $single = 0;
2510
2511 # No signal is active.
2512 $signal = 0;
2513
2514 # Handle continued commands (ending with \):
3d7a2a93 2515 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2516 $cmd .= DB::readline(" cont: ");
e22ea7cc 2517 redo CMD;
3d7a2a93 2518 }
69893cff
RGS
2519
2520=head4 The null command
2521
be9a9b1d 2522A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2523command out of C<$laststep> (where it was recorded previously), and copy it
2524back into C<$cmd> to be executed below. If there wasn't any previous command,
2525we'll do nothing below (no command will match). If there was, we also save it
2526in the command history and fall through to allow the command parsing to pick
2527it up.
2528
2529=cut
2530
2531 # Empty input means repeat the last command.
eeb7da96
SF
2532 if ($cmd eq '') {
2533 $cmd = $laststep;
2534 }
e22ea7cc 2535 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2536 if (length($cmd) >= 2) {
2537 push( @hist, $cmd );
2538 }
e22ea7cc 2539 push( @truehist, $cmd );
2dbd01ad
SF
2540 share(@hist);
2541 share(@truehist);
e22ea7cc
RF
2542
2543 # This is a restart point for commands that didn't arrive
2544 # via direct user input. It allows us to 'redo PIPE' to
2545 # re-execute command processing without reading a new command.
69893cff 2546 PIPE: {
35cd713a 2547 $i = _DB__trim_command_and_return_first_component();
69893cff
RGS
2548
2549=head3 COMMAND ALIASES
2550
2551The debugger can create aliases for commands (these are stored in the
2552C<%alias> hash). Before a command is executed, the command loop looks it up
2553in the alias hash and substitutes the contents of the alias for the command,
2554completely replacing it.
2555
2556=cut
2557
2558 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2559 if ( $alias{$i} ) {
2560
69893cff
RGS
2561 # Squelch signal handling; we want to keep control here
2562 # if something goes loco during the alias eval.
2563 local $SIG{__DIE__};
2564 local $SIG{__WARN__};
2565
2566 # This is a command, so we eval it in the DEBUGGER's
2567 # scope! Otherwise, we can't see the special debugger
2568 # variables, or get to the debugger's subs. (Well, we
2569 # _could_, but why make it even more complicated?)
2570 eval "\$cmd =~ $alias{$i}";
2571 if ($@) {
2572 local $\ = '';
1f874cb6 2573 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2574 next CMD;
2575 }
2576 } ## end if ($alias{$i})
2577
2578=head3 MAIN-LINE COMMANDS
2579
2580All of these commands work up to and after the program being debugged has
b570d64b 2581terminated.
69893cff
RGS
2582
2583=head4 C<q> - quit
2584
b570d64b 2585Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2586try to execute further, cleaning any restart-related stuff out of the
2587environment, and executing with the last value of C<$?>.
2588
2589=cut
2590
3d7a2a93 2591 if ($cmd eq 'q') {
69893cff
RGS
2592 $fall_off_end = 1;
2593 clean_ENV();
2594 exit $?;
3d7a2a93 2595 }
69893cff 2596
611272bb 2597=head4 C<t> - trace [n]
69893cff
RGS
2598
2599Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2600If level is specified, set C<$trace_to_depth>.
69893cff
RGS
2601
2602=cut
2603
9d0b71b3 2604 $obj->_handle_t_command;
69893cff
RGS
2605
2606=head4 C<S> - list subroutines matching/not matching a pattern
2607
2608Walks through C<%sub>, checking to see whether or not to print the name.
2609
2610=cut
2611
9d0b71b3 2612 $obj->_handle_S_command;
69893cff
RGS
2613
2614=head4 C<X> - list variables in current package
2615
b570d64b 2616Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2617appropriate C<V> command and fall through.
2618
69893cff
RGS
2619=head4 C<V> - list variables
2620
b570d64b 2621Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff
RGS
2622
2623=cut
2624
1ce985d2 2625 $obj->_handle_V_command_and_X_command;
69893cff
RGS
2626
2627=head4 C<x> - evaluate and print an expression
2628
2629Hands the expression off to C<DB::eval>, setting it up to print the value
2630via C<dumpvar.pl> instead of just printing it directly.
2631
2632=cut
2633
826b9a2e 2634 if ($cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval()
e22ea7cc 2635 $onetimeDump = 'dump'; # main::dumpvar shows the output
69893cff
RGS
2636
2637 # handle special "x 3 blah" syntax XXX propagate
2638 # doc back to special variables.
826b9a2e 2639 if ( $cmd =~ s#\A\s*(\d+)(?=\s)# #) {
e22ea7cc
RF
2640 $onetimedumpDepth = $1;
2641 }
826b9a2e 2642 }
69893cff
RGS
2643
2644=head4 C<m> - print methods
2645
2646Just uses C<DB::methods> to determine what methods are available.
2647
2648=cut
2649
826b9a2e 2650 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
e22ea7cc
RF
2651 methods($1);
2652 next CMD;
826b9a2e 2653 }
69893cff
RGS
2654
2655 # m expr - set up DB::eval to do the work
826b9a2e 2656 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
e22ea7cc 2657 $onetimeDump = 'methods'; # method output gets used there
826b9a2e 2658 }
69893cff
RGS
2659
2660=head4 C<f> - switch files
2661
2662=cut
2663
2a802473 2664 _DB__handle_f_command();
69893cff
RGS
2665
2666=head4 C<.> - return to last-executed line.
2667
2668We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2669and then we look up the line in the magical C<%dbline> hash.
2670
2671=cut
2672
6115a173 2673 _DB__handle_dot_command($obj);
69893cff
RGS
2674
2675=head4 C<-> - back one window
2676
2677We change C<$start> to be one window back; if we go back past the first line,
2678we set it to be the first line. We ser C<$incr> to put us back at the
2679currently-executing line, and then put a C<l $start +> (list one window from
2680C<$start>) in C<$cmd> to be executed later.
2681
2682=cut
2683
2684 # - - back a window.
d1450c23 2685 $obj->_handle_dash_command;
69893cff 2686
8481f647 2687=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2688
2689In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2690problems, most notably that the default case of several commands destroying
2691the user's work in setting watchpoints, actions, etc. We wanted, however, to
2692retain the old commands for those who were used to using them or who preferred
2693them. At this point, we check for the new commands and call C<cmd_wrapper> to
2694deal with them instead of processing them in-line.
2695
2696=cut
2697
2698 # All of these commands were remapped in perl 5.8.0;
e22ea7cc 2699 # we send them off to the secondary dispatcher (see below).
826b9a2e
SF
2700 if (my ($cmd_letter, $my_arg) = $cmd =~ /\A([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so) {
2701 &cmd_wrapper( $cmd_letter, $my_arg, $line );
e22ea7cc 2702 next CMD;
826b9a2e 2703 }
69893cff
RGS
2704
2705=head4 C<y> - List lexicals in higher scope
2706
826b9a2e 2707Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2708above the current one and then displays then using C<dumpvar.pl>.
2709
2710=cut
2711
5c2b78e7 2712 _DB__handle_y_command($obj);
69893cff
RGS
2713
2714=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2715
2716All of the commands below this point don't work after the program being
2717debugged has ended. All of them check to see if the program has ended; this
2718allows the commands to be relocated without worrying about a 'line of
2719demarcation' above which commands can be entered anytime, and below which
2720they can't.
2721
2722=head4 C<n> - single step, but don't trace down into subs
2723
2724Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2725when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2726so a null command knows what to re-execute.
69893cff
RGS
2727
2728=cut
2729
e22ea7cc 2730 # n - next
73c5e526 2731 $obj->_handle_n_command;
69893cff
RGS
2732
2733=head4 C<s> - single-step, entering subs
2734
826b9a2e 2735Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2736subs. Also saves C<s> as C<$lastcmd>.
2737
2738=cut
2739
cb9d1513 2740 $obj->_handle_s_command;
69893cff
RGS
2741
2742=head4 C<c> - run continuously, setting an optional breakpoint
2743
2744Most of the code for this command is taken up with locating the optional
2745breakpoint, which is either a subroutine name or a line number. We set
2746the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2747in this and all call levels above this one.
2748
2749=cut
2750
2751 # c - start continuous execution.
35cd713a 2752 _DB__handle_c_command($obj);
69893cff
RGS
2753
2754=head4 C<r> - return from a subroutine
2755
2756For C<r> to work properly, the debugger has to stop execution again
2757immediately after the return is executed. This is done by forcing
2758single-stepping to be on in the call level above the current one. If
2759we are printing return values when a C<r> is executed, set C<$doret>
2760appropriately, and force us out of the command loop.
2761
2762=cut
2763
2764 # r - return from the current subroutine.
573b5003 2765 $obj->_handle_r_command;
69893cff 2766
69893cff
RGS
2767=head4 C<T> - stack trace
2768
2769Just calls C<DB::print_trace>.
2770
2771=cut
2772
d4038e14 2773 $obj->_handle_T_command;
69893cff
RGS
2774
2775=head4 C<w> - List window around current line.
2776
2777Just calls C<DB::cmd_w>.
2778
2779=cut
2780
b6e88520 2781 $obj->_handle_w_command;
69893cff
RGS
2782
2783=head4 C<W> - watch-expression processing.
2784
b570d64b 2785Just calls C<DB::cmd_W>.
69893cff
RGS
2786
2787=cut
2788
25953301 2789 $obj->_handle_W_command;
69893cff
RGS
2790
2791=head4 C</> - search forward for a string in the source
2792
ef18ae63 2793We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2794bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2795If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2796mess us up.
2797
2798=cut
2799
a4d311a3 2800 _DB__handle_forward_slash_command($obj);
69893cff
RGS
2801
2802=head4 C<?> - search backward for a string in the source
2803
2804Same as for C</>, except the loop runs backwards.
2805
2806=cut
2807
11f0f050 2808 _DB__handle_question_mark_command($obj);
69893cff
RGS
2809
2810=head4 C<$rc> - Recall command
2811
2812Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2813that the terminal supports history). It find the the command required, puts it
2814into C<$cmd>, and redoes the loop to execute it.
2815
2816=cut
2817
e22ea7cc 2818 # $rc - recall command.
14f38b27 2819 $obj->_handle_rc_recall_command;
69893cff
RGS
2820
2821=head4 C<$sh$sh> - C<system()> command
2822
2823Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2824C<STDOUT> from getting messed up.
2825
2826=cut
2827
2828 # $sh$sh - run a shell command (if it's all ASCII).
2829 # Can't run shell commands with Unicode in the debugger, hmm.
ef18ae63 2830 if (my ($arg) = $cmd =~ m#\A$sh$sh\s*(.*)#ms) {
e22ea7cc 2831
69893cff 2832 # System it.
6bffb264 2833 DB::system($arg);
e22ea7cc 2834 next CMD;
ef18ae63 2835 }
69893cff
RGS
2836
2837=head4 C<$rc I<pattern> $rc> - Search command history
2838
2839Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2840If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2841
2842=cut
2843
0d2c714c 2844 $obj->_handle_rc_search_history_command;
69893cff 2845
ef18ae63 2846=head4 C<$sh> - Invoke a shell
69893cff
RGS
2847
2848Uses C<DB::system> to invoke a shell.
2849
2850=cut
2851
2852 # $sh - start a shell.
ef18ae63 2853 if ($cmd =~ /\A$sh\z/) {
e22ea7cc 2854
69893cff
RGS
2855 # Run the user's shell. If none defined, run Bourne.
2856 # We resume execution when the shell terminates.
e22ea7cc
RF
2857 &system( $ENV{SHELL} || "/bin/sh" );
2858 next CMD;
ef18ae63 2859 }
69893cff
RGS
2860
2861=head4 C<$sh I<command>> - Force execution of a command in a shell
2862
2863Like the above, but the command is passed to the shell. Again, we use
2864C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2865
2866=cut
2867
2868 # $sh command - start a shell and run a command in it.
ef18ae63 2869 if (my ($arg) = $cmd =~ m#\A$sh\s*(.*)#ms) {
e22ea7cc
RF
2870
2871 # XXX: using csh or tcsh destroys sigint retvals!
2872 #&system($1); # use this instead
69893cff
RGS
2873
2874 # use the user's shell, or Bourne if none defined.
ef18ae63 2875 &system( $ENV{SHELL} || "/bin/sh", "-c", $arg );
e22ea7cc 2876 next CMD;
ef18ae63 2877 }
69893cff
RGS
2878
2879=head4 C<H> - display commands in history
2880
2881Prints the contents of C<@hist> (if any).
2882
2883=cut
2884
0664c09a 2885 $obj->_handle_H_command;
69893cff
RGS
2886
2887=head4 C<man, doc, perldoc> - look up documentation
2888
2889Just calls C<runman()> to print the appropriate document.
2890
2891=cut
2892
c7b0c61d 2893 $obj->_handle_doc_command;
69893cff
RGS
2894
2895=head4 C<p> - print
2896
2897Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2898the bottom of the loop.
2899
2900=cut
2901
b6aeebb8 2902 $obj->_handle_p_command;
69893cff
RGS
2903
2904=head4 C<=> - define command alias
2905
2906Manipulates C<%alias> to add or list command aliases.
2907
2908=cut
2909
e22ea7cc 2910 # = - set up a command alias.
bdb3f37d 2911 $obj->_handle_equal_sign_command;
69893cff
RGS
2912
2913=head4 C<source> - read commands from a file.
2914
2915Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
2916pick it up.
2917
2918=cut
2919
2ef1dcdb 2920 $obj->_handle_source_command;
69893cff 2921
d0ecd4f3 2922=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 2923
d0ecd4f3 2924This enables or disables breakpoints.
e09195af 2925
d0ecd4f3
SF
2926=cut
2927
2928 $obj->_handle_enable_disable_commands;
e09195af 2929
69893cff
RGS
2930=head4 C<save> - send current history to a file
2931
2932Takes the complete history, (not the shrunken version you see with C<H>),
2933and saves it to the given filename, so it can be replayed using C<source>.
2934
2935Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
2936
2937=cut
2938
2939 # save source - write commands to a file for later use
8baafc8b 2940 $obj->_handle_save_command;
69893cff 2941
7fddc82f
RF
2942=head4 C<R> - restart
2943
ef18ae63 2944Restart the debugger session.
7fddc82f
RF
2945
2946=head4 C<rerun> - rerun the current session
2947
2948Return to any given position in the B<true>-history list
2949
2950=cut
2951
2952 # R - restart execution.
2953 # rerun - controlled restart execution.
5f166812 2954 _DB__handle_restart_and_rerun_commands($obj);
7fddc82f 2955
69893cff
RGS
2956=head4 C<|, ||> - pipe output through the pager.
2957
be9a9b1d 2958For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
2959(the program's standard output). For C<||>, we only save C<OUT>. We open a
2960pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 2961is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
2962set C<$signal>, sending us back into the debugger.
2963
2964We then trim off the pipe symbols and C<redo> the command loop at the
2965C<PIPE> label, causing us to evaluate the command in C<$cmd> without
2966reading another.
2967
2968=cut
2969
2970 # || - run command in the pager, with output to DB::OUT.
ff41e38d 2971 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
e22ea7cc
RF
2972 if ( $pager =~ /^\|/ ) {
2973
69893cff 2974 # Default pager is into a pipe. Redirect I/O.
e22ea7cc
RF
2975 open( SAVEOUT, ">&STDOUT" )
2976 || &warn("Can't save STDOUT");
2977 open( STDOUT, ">&OUT" )
2978 || &warn("Can't redirect STDOUT");
69893cff 2979 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
2980 else {
2981
69893cff 2982 # Not into a pipe. STDOUT is safe.
e22ea7cc
RF
2983 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
2984 }
69893cff
RGS
2985
2986 # Fix up environment to record we have less if so.
e22ea7cc
RF
2987 fix_less();
2988
2989 unless ( $piped = open( OUT, $pager ) ) {
69893cff 2990
69893cff 2991 # Couldn't open pipe to pager.
1f874cb6 2992 &warn("Can't pipe output to '$pager'");
e22ea7cc
RF
2993 if ( $pager =~ /^\|/ ) {
2994
69893cff 2995 # Redirect I/O back again.
e22ea7cc
RF
2996 open( OUT, ">&STDOUT" ) # XXX: lost message
2997 || &warn("Can't restore DB::OUT");
2998 open( STDOUT, ">&SAVEOUT" )
2999 || &warn("Can't restore STDOUT");
3000 close(SAVEOUT);
69893cff 3001 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3002 else {
3003
69893cff 3004 # Redirect I/O. STDOUT already safe.
e22ea7cc
RF
3005 open( OUT, ">&STDOUT" ) # XXX: lost message
3006 || &warn("Can't restore DB::OUT");
3007 }
3008 next CMD;
69893cff
RGS
3009 } ## end unless ($piped = open(OUT,...
3010
3011 # Set up broken-pipe handler if necessary.
e22ea7cc
RF
3012 $SIG{PIPE} = \&DB::catch
3013 if $pager =~ /^\|/
3014 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
69893cff 3015
70c9432b
SF
3016 OUT->autoflush(1);
3017 # Save current filehandle, and put it back.
e22ea7cc 3018 $selected = select(OUT);
69893cff 3019 # Don't put it back if pager was a pipe.
e22ea7cc 3020 select($selected), $selected = "" unless $cmd =~ /^\|\|/;
69893cff
RGS
3021
3022 # Trim off the pipe symbols and run the command now.
ff41e38d 3023 $cmd =~ s#\A\|+\s*##;
e22ea7cc 3024 redo PIPE;
ff41e38d 3025 }
69893cff
RGS
3026
3027=head3 END OF COMMAND PARSING
3028
ff41e38d
SF
3029Anything left in C<$cmd> at this point is a Perl expression that we want to
3030evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3031any variables we might want to address in the C<DB> package.
3032
3033=cut
3034
3035 # t - turn trace on.
ff41e38d
SF
3036 if ($cmd =~ s#\At\s+(\d+)?#\$DB::trace |= 1;\n#) {
3037 my $trace_arg = $1;
3038 $trace_to_depth = $trace_arg ? $stack_depth||0 + $1 : 1E9;
3039 }
69893cff
RGS
3040
3041 # s - single-step. Remember the last command was 's'.
ff41e38d
SF
3042 if ($cmd =~ s/\As\s/\$DB::single = 1;\n/) {
3043 $laststep = 's';
3044 }
69893cff
RGS
3045
3046 # n - single-step, but not into subs. Remember last command
e22ea7cc 3047 # was 'n'.
ff41e38d
SF
3048 if ($cmd =~ s#\An\s#\$DB::single = 2;\n#) {
3049 $laststep = 'n';
3050 }
69893cff 3051
e22ea7cc 3052 } # PIPE:
69893cff 3053
e22ea7cc 3054 # Make sure the flag that says "the debugger's running" is
69893cff 3055 # still on, to make sure we get control again.
e22ea7cc 3056 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3057
3058 # Run *our* eval that executes in the caller's context.
7c54f46a 3059 DB::eval();
69893cff
RGS
3060
3061 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3062 if ($onetimeDump) {
3063 $onetimeDump = undef;
69893cff 3064 $onetimedumpDepth = undef;
e22ea7cc
RF
3065 }
3066 elsif ( $term_pid == $$ ) {
8380a245 3067 eval { # May run under miniperl, when not available...
c7e68384
IZ
3068 STDOUT->flush();
3069 STDERR->flush();
8380a245 3070 };
e22ea7cc 3071
69893cff 3072 # XXX If this is the master pid, print a newline.
8380a245 3073 print {$OUT} "\n";
e22ea7cc
RF
3074 }
3075 } ## end while (($term || &setterm...
69893cff
RGS
3076
3077=head3 POST-COMMAND PROCESSING
3078
3079After each command, we check to see if the command output was piped anywhere.
3080If so, we go through the necessary code to unhook the pipe and go back to
3081our standard filehandles for input and output.
3082
3083=cut
3084
e22ea7cc 3085 continue { # CMD:
69893cff
RGS
3086
3087 # At the end of every command:
e22ea7cc
RF
3088 if ($piped) {
3089
69893cff 3090 # Unhook the pipe mechanism now.
e22ea7cc
RF
3091 if ( $pager =~ /^\|/ ) {
3092
69893cff 3093 # No error from the child.
e22ea7cc 3094 $? = 0;
69893cff 3095
e22ea7cc
RF
3096 # we cannot warn here: the handle is missing --tchrist
3097 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
69893cff 3098
e22ea7cc 3099 # most of the $? crud was coping with broken cshisms
69893cff 3100 # $? is explicitly set to 0, so this never runs.
e22ea7cc 3101 if ($?) {
1f874cb6 3102 print SAVEOUT "Pager '$pager' failed: ";
e22ea7cc
RF
3103 if ( $? == -1 ) {
3104 print SAVEOUT "shell returned -1\n";
3105 }
3106 elsif ( $? >> 8 ) {
3107 print SAVEOUT ( $? & 127 )
3108 ? " (SIG#" . ( $? & 127 ) . ")"
3109 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
3110 }
3111 else {
3112 print SAVEOUT "status ", ( $? >> 8 ), "\n";
3113 }
69893cff
RGS
3114 } ## end if ($?)
3115
e22ea7cc 3116 # Reopen filehandle for our output (if we can) and
69893cff 3117 # restore STDOUT (if we can).
e22ea7cc
RF
3118 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
3119 open( STDOUT, ">&SAVEOUT" )
3120 || &warn("Can't restore STDOUT");
69893cff
RGS
3121
3122 # Turn off pipe exception handler if necessary.
e22ea7cc 3123 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
69893cff 3124
e22ea7cc
RF
3125 # Will stop ignoring SIGPIPE if done like nohup(1)
3126 # does SIGINT but Perl doesn't give us a choice.
69893cff 3127 } ## end if ($pager =~ /^\|/)
e22ea7cc
RF
3128 else {
3129
69893cff 3130 # Non-piped "pager". Just restore STDOUT.
e22ea7cc
RF
3131 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
3132 }
69893cff
RGS
3133
3134 # Close filehandle pager was using, restore the normal one
3135 # if necessary,
3136 close(SAVEOUT);
e22ea7cc 3137 select($selected), $selected = "" unless $selected eq "";
69893cff
RGS
3138
3139 # No pipes now.
e22ea7cc 3140 $piped = "";
69893cff 3141 } ## end if ($piped)
e22ea7cc 3142 } # CMD:
69893cff
RGS
3143
3144=head3 COMMAND LOOP TERMINATION
3145
3146When commands have finished executing, we come here. If the user closed the
3147input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3148evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3149C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3150The interpreter will then execute the next line and then return control to us
3151again.
3152
3153=cut
3154
3155 # No more commands? Quit.
1f874cb6 3156 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3157
3158 # Evaluate post-prompt commands.
e22ea7cc 3159 foreach $evalarg (@$post) {
7c54f46a 3160 DB::eval();
e22ea7cc
RF
3161 }
3162 } # if ($single || $signal)
69893cff
RGS
3163
3164 # Put the user's globals back where you found them.
e22ea7cc 3165 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3166 ();
3167} ## end sub DB
3168
22fc883d
SF
3169package DB::Obj;
3170
3171sub new {
3172 my $class = shift;
3173
3174 my $self = bless {}, $class;
3175
3176 $self->_init(@_);
3177
3178 return $self;
3179}
3180
3181sub _init {
3182 my ($self, $args) = @_;
3183
3184 %{$self} = (%$self, %$args);
3185
3186 return;
3187}
3188
3189{
3190 no strict 'refs';
a4d311a3
SF
3191 foreach my $slot_name (qw(
3192 after explicit_stop infix pat position prefix i_cmd
3193 )) {
22fc883d
SF
3194 my $slot = $slot_name;
3195 *{$slot} = sub {
3196 my $self = shift;
3197
3198 if (@_) {
3199 ${ $self->{$slot} } = shift;
3200 }
3201
3202 return ${ $self->{$slot} };
3203 };
8def6eff
SF
3204
3205 *{"append_to_$slot"} = sub {
3206 my $self = shift;
3207 my $s = shift;
3208
3209 return $self->$slot($self->$slot . $s);
3210 };
22fc883d
SF
3211 }
3212}
3213
3214sub _DB_on_init__initialize_globals
3215{
3216 my $self = shift;
3217
3218 # Check for whether we should be running continuously or not.
3219 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3220 if ( $single and not $second_time++ ) {
22fc883d
SF
3221
3222 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3223 if ($runnonstop) { # Disable until signal
22fc883d
SF
3224 # If there's any call stack in place, turn off single
3225 # stepping into subs throughout the stack.
8ad70697
SF
3226 for my $i (0 .. $stack_depth) {
3227 $stack[ $i ] &= ~1;
22fc883d
SF
3228 }
3229
3230 # And we are now no longer in single-step mode.
ebd0282e 3231 $single = 0;
22fc883d
SF
3232
3233 # If we simply returned at this point, we wouldn't get
3234 # the trace info. Fall on through.
3235 # return;
3236 } ## end if ($runnonstop)
3237
8ad70697 3238 elsif ($ImmediateStop) {
22fc883d
SF
3239
3240 # We are supposed to stop here; XXX probably a break.
8ad70697 3241 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3242 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3243 # us into the command loop
3244 }
3245 } ## end if ($single and not $second_time...
3246
3247 # If we're in single-step mode, or an interrupt (real or fake)
3248 # has occurred, turn off non-stop mode.
ebd0282e 3249 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3250
3251 return;
3252}
3253
3254sub _DB__handle_watch_expressions
3255{
3256 my $self = shift;
3257
931ac036 3258 if ( $trace & 2 ) {
8ad70697
SF
3259 for my $n (0 .. $#to_watch) {
3260 $evalarg = $to_watch[$n];
3261 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3262
3263 # Fix context DB::eval() wants to return an array, but
3264 # we need a scalar here.
7c54f46a 3265 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3266 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3267
3268 # Did it change?
8ad70697 3269 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3270
3271 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3272 $signal = 1;
8ad70697
SF
3273 print {$OUT} <<EOP;
3274Watchpoint $n:\t$to_watch[$n] changed:
3275 old value:\t$old_watch[$n]
22fc883d
SF
3276 new value:\t$val
3277EOP
8ad70697 3278 $old_watch[$n] = $val;
22fc883d
SF
3279 } ## end if ($val ne $old_watch...
3280 } ## end for my $n (0 ..
3281 } ## end if ($trace & 2)
3282
3283 return;
3284}
3285
ad46ac70
SF
3286sub _my_print_lineinfo
3287{
3288 my ($self, $i, $incr_pos) = @_;
3289
18b5b545 3290 if ($frame) {
ad46ac70 3291 # Print it indented if tracing is on.
8ad70697 3292 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3293 "$i:\t$DB::dbline[$i]" . $self->after );
3294 }
3295 else {
3296 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3297 }
3298}
3299
44a07e3e 3300sub _curr_line {
18b5b545 3301 return $DB::dbline[$line];
44a07e3e
SF
3302}
3303
22fc883d
SF
3304sub _DB__grab_control
3305{
3306 my $self = shift;
3307
3308 # Yes, grab control.
7793e5c2 3309 if ($slave_editor) {
22fc883d
SF
3310
3311 # Tell the editor to update its position.
18b5b545 3312 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3313 DB::print_lineinfo($self->position());
3314 }
3315
3316=pod
3317
3318Special check: if we're in package C<DB::fake>, we've gone through the
3319C<END> block at least once. We set up everything so that we can continue
3320to enter commands and have a valid context to be in.
3321
3322=cut
3323
3324 elsif ( $DB::package eq 'DB::fake' ) {
3325
3326 # Fallen off the end already.
3327 if (!$DB::term) {
3328 DB::setterm();
3329 }
3330
3331 DB::print_help(<<EOP);
3332Debugged program terminated. Use B<q> to quit or B<R> to restart,
3333use B<o> I<inhibit_exit> to avoid stopping after program termination,
3334B<h q>, B<h R> or B<h o> to get additional info.
3335EOP
3336
3337 # Set the DB::eval context appropriately.
3338 $DB::package = 'main';
3339 $DB::usercontext = DB::_calc_usercontext($DB::package);
3340 } ## end elsif ($package eq 'DB::fake')
3341
3342=pod
3343
3344If the program hasn't finished executing, we scan forward to the
3345next executable line, print that out, build the prompt from the file and line
3346number information, and print that.
3347
3348=cut
3349
3350 else {
3351
3352
3353 # Still somewhere in the midst of execution. Set up the
3354 # debugger prompt.
3355 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3356 # Perl 5 ones (sorry, we don't print Klingon
3357 #module names)
3358
3359 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3360 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3361 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3362
3363 # Break up the prompt if it's really long.
3364 if ( length($self->prefix()) > 30 ) {
18b5b545 3365 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3366 $self->prefix("");
3367 $self->infix(":\t");
3368 }
3369 else {
3370 $self->infix("):\t");
3371 $self->position(
18b5b545 3372 $self->prefix . $line. $self->infix
44a07e3e 3373 . $self->_curr_line . $self->after
22fc883d
SF
3374 );
3375 }
3376
3377 # Print current line info, indenting if necessary.
18b5b545 3378 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3379
44a07e3e
SF
3380 my $i;
3381 my $line_i = sub { return $DB::dbline[$i]; };
3382
22fc883d
SF
3383 # Scan forward, stopping at either the end or the next
3384 # unbreakable line.
18b5b545 3385 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3386 { #{ vi
3387
3388 # Drop out on null statements, block closers, and comments.
44a07e3e 3389 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3390
3391 # Drop out if the user interrupted us.
ebd0282e 3392 last if $signal;
22fc883d
SF
3393
3394 # Append a newline if the line doesn't have one. Can happen
3395 # in eval'ed text, for instance.
44a07e3e 3396 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3397
3398 # Next executable line.
44a07e3e 3399 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3400 . $self->after;
8def6eff 3401 $self->append_to_position($incr_pos);
ad46ac70 3402 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3403 } ## end for ($i = $line + 1 ; $i...
3404 } ## end else [ if ($slave_editor)
3405
3406 return;
3407}
3408
174f9c5e
SF
3409sub _handle_t_command {
3410 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
931ac036 3411 $trace ^= 1;
174f9c5e 3412 local $\ = '';
8ad70697
SF
3413 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3414 print {$OUT} "Trace = "
931ac036 3415 . ( ( $trace & 1 )
174f9c5e
SF
3416 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3417 : "off" ) . "\n";
3418 next CMD;
3419 }
3420
3421 return;
3422}
3423
9d0b71b3
SF
3424
3425sub _handle_S_command {
3426 if (my ($print_all_subs, $should_reverse, $Spatt)
3427 = $DB::cmd =~ /\AS(\s+(!)?(.+))?\z/) {
3428 # $Spatt is the pattern (if any) to use.
3429 # Reverse scan?
3430 my $Srev = defined $should_reverse;
3431 # No args - print all subs.
3432 my $Snocheck = !defined $print_all_subs;
3433
3434 # Need to make these sane here.
3435 local $\ = '';
3436 local $, = '';
3437
3438 # Search through the debugger's magical hash of subs.
3439 # If $nocheck is true, just print the sub name.
3440 # Otherwise, check it against the pattern. We then use
3441 # the XOR trick to reverse the condition as required.
3442 foreach $subname ( sort( keys %sub ) ) {
3443 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3444 print $OUT $subname, "\n";
3445 }
3446 }
3447 next CMD;
3448 }
3449
3450 return;
3451}
3452
1ce985d2
SF
3453sub _handle_V_command_and_X_command {
3454
3455 $DB::cmd =~ s/^X\b/V $DB::package/;
3456
3457 # Bare V commands get the currently-being-debugged package
3458 # added.
3459 if ($DB::cmd eq "V") {
3460 $DB::cmd = "V $DB::package";
3461 }
3462
3463 # V - show variables in package.
3464 if (my ($new_packname, $new_vars_str) =
3465 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3466
3467 # Save the currently selected filehandle and
3468 # force output to debugger's filehandle (dumpvar
3469 # just does "print" for output).
3470 my $savout = select($OUT);
3471
3472 # Grab package name and variables to dump.
3473 $packname = $new_packname;
3474 my @vars = split( ' ', $new_vars_str );
3475
3476 # If main::dumpvar isn't here, get it.
3477 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3478 if ( defined &main::dumpvar ) {
3479
3480 # We got it. Turn off subroutine entry/exit messages
3481 # for the moment, along with return values.
3482 local $frame = 0;
3483 local $doret = -2;
3484
3485 # must detect sigpipe failures - not catching
3486 # then will cause the debugger to die.
3487 eval {
3488 &main::dumpvar(
3489 $packname,
3490 defined $option{dumpDepth}
3491 ? $option{dumpDepth}
3492 : -1, # assume -1 unless specified
3493 @vars
3494 );
3495 };
3496
3497 # The die doesn't need to include the $@, because
3498 # it will automatically get propagated for us.
3499 if ($@) {
3500 die unless $@ =~ /dumpvar print failed/;
3501 }
3502 } ## end if (defined &main::dumpvar)
3503 else {
3504
3505 # Couldn't load dumpvar.
3506 print $OUT "dumpvar.pl not available.\n";
3507 }
3508
3509 # Restore the output filehandle, and go round again.
3510 select($savout);
3511 next CMD;
3512 }
3513
3514 return;
3515}
3516
d1450c23
SF
3517sub _handle_dash_command {
3518
3519 if ($DB::cmd eq '-') {
3520
3521 # back up by a window; go to 1 if back too far.
3522 $start -= $incr + $window + 1;
3523 $start = 1 if $start <= 0;
3524 $incr = $window - 1;
3525
3526 # Generate and execute a "l +" command (handled below).
3527 $DB::cmd = 'l ' . ($start) . '+';
3528 }
3529 return;
3530}
3531
cb9d1513
SF
3532sub _n_or_s_commands_generic {
3533 my ($self, $new_val) = @_;
73c5e526 3534 # n - next
cb9d1513 3535 next CMD if DB::_DB__is_finished();
73c5e526 3536
cb9d1513
SF
3537 # Single step, but don't enter subs.
3538 $single = $new_val;
3539
3540 # Save for empty command (repeat last).
3541 $laststep = $DB::cmd;
3542 last CMD;
3543}
73c5e526 3544
cb9d1513
SF
3545sub _n_or_s {
3546 my ($self, $letter, $new_val) = @_;
3547
3548 if ($DB::cmd eq $letter) {
3549 $self->_n_or_s_commands_generic($new_val);
73c5e526
SF
3550 }
3551
3552 return;
3553}
3554
cb9d1513
SF
3555sub _handle_n_command {
3556 my $self = shift;
3557
3558 return $self->_n_or_s('n', 2);
3559}
3560
3561sub _handle_s_command {
3562 my $self = shift;
3563
3564 return $self->_n_or_s('s', 1);
3565}
3566
573b5003
SF
3567sub _handle_r_command {
3568 my $self = shift;
3569 # r - return from the current subroutine.
3570 if ($DB::cmd eq 'r') {
3571
3572 # Can't do anything if the program's over.
3573 next CMD if DB::_DB__is_finished();
3574
3575 # Turn on stack trace.
3576 $stack[$stack_depth] |= 1;
3577
3578 # Print return value unless the stack is empty.
3579 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3580 last CMD;
3581 }
3582
3583 return;
3584}
3585
d4038e14
SF
3586sub _handle_T_command {
3587 if ($DB::cmd eq 'T') {
3588 DB::print_trace( $OUT, 1 ); # skip DB
3589 next CMD;
3590 }
3591
3592 return;
3593}
3594
b6e88520
SF
3595sub _handle_w_command {
3596 if (my ($arg) = $DB::cmd =~ /\Aw\b\s*(.*)/s) {
3597 DB::cmd_w( 'w', $arg );
3598 next CMD;
3599 }
3600
3601 return;
3602}
3603
25953301
SF
3604sub _handle_W_command {
3605 if (my ($arg) = $DB::cmd =~ /\AW\b\s*(.*)/s) {
3606 DB::cmd_W( 'W', $arg );
3607 next CMD;
3608 }
3609
3610 return;
3611}
3612
14f38b27
SF
3613sub _handle_rc_recall_command {
3614 my $self = shift;
3615
3616 # $rc - recall command.
3617 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3618
3619 # No arguments, take one thing off history.
3620 pop(@hist) if length($DB::cmd) > 1;
3621
3622 # Relative (- found)?
3623 # Y - index back from most recent (by 1 if bare minus)
3624 # N - go to that particular command slot or the last
3625 # thing if nothing following.
3626 my $new_i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
3627
3628 $self->i_cmd($new_i);
3629
3630 # Pick out the command desired.
3631 $DB::cmd = $hist[$self->i_cmd];
3632
3633 # Print the command to be executed and restart the loop
3634 # with that command in the buffer.
3635 print {$OUT} $DB::cmd, "\n";
3636 redo CMD;
3637 }
3638
3639 return;
3640}
3641
0d2c714c
SF
3642sub _handle_rc_search_history_command {
3643 my $self = shift;
3644
3645 # $rc pattern $rc - find a command in the history.
3646 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3647
3648 # Create the pattern to use.
3649 my $pat = "^$arg";
3650 $self->pat($pat);
3651
3652 # Toss off last entry if length is >1 (and it always is).
3653 pop(@hist) if length($DB::cmd) > 1;
3654
3655 my $i = $self->i_cmd;
3656
3657 # Look backward through the history.
3658 SEARCH_HIST:
3659 for ( $i = $#hist ; $i ; --$i ) {
3660 # Stop if we find it.
3661 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3662 }
3663
3664 $self->i_cmd($i);
3665
3666 if ( !$self->i_cmd ) {
3667
3668 # Never found it.
3669 print $OUT "No such command!\n\n";
3670 next CMD;
3671 }
3672
3673 # Found it. Put it in the buffer, print it, and process it.
3674 $DB::cmd = $hist[$self->i_cmd];
3675 print $OUT $DB::cmd, "\n";
3676 redo CMD;
3677 }
b6aeebb8
SF
3678
3679 return;
0d2c714c
SF
3680}
3681
0664c09a
SF
3682sub _handle_H_command {
3683 my $self = shift;
3684
3685 if ($DB::cmd =~ /\AH\b\s*\*/) {
3686 @hist = @truehist = ();
3687 print $OUT "History cleansed\n";
3688 next CMD;
3689 }
3690
3691 if (my ($num)
3692 = $DB::cmd =~ /\AH\b\s*(?:-(\d+))?/) {
3693
3694 # Anything other than negative numbers is ignored by
3695 # the (incorrect) pattern, so this test does nothing.
3696 $end = $num ? ( $#hist - $num ) : 0;
3697
3698 # Set to the minimum if less than zero.
3699 $hist = 0 if $hist < 0;
3700
3701 # Start at the end of the array.
3702 # Stay in while we're still above the ending value.
3703 # Tick back by one each time around the loop.
3704 my $i;
3705
3706 for ( $i = $#hist ; $i > $end ; $i-- ) {
3707
3708 # Print the command unless it has no arguments.
3709 print $OUT "$i: ", $hist[$i], "\n"
3710 unless $hist[$i] =~ /^.?$/;
3711 }
3712
3713 $self->i_cmd($i);
3714
3715 next CMD;
3716 }
3717
3718 return;
3719}
3720
c7b0c61d
SF
3721sub _handle_doc_command {
3722 my $self = shift;
3723
3724 # man, perldoc, doc - show manual pages.
3725 if (my ($man_page)
3726 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3727 runman($man_page);
3728 next CMD;
3729 }
3730
3731 return;
3732}
3733
b6aeebb8
SF
3734sub _handle_p_command {
3735 my $self = shift;
3736
3737 my $print_cmd = 'print {$DB::OUT} ';
3738 # p - print (no args): print $_.
3739 if ($DB::cmd eq 'p') {
3740 $DB::cmd = $print_cmd . '$_';
3741 }
3742
3743 # p - print the given expression.
3744 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3745
3746 return;
3747}
3748
bdb3f37d
SF
3749sub _handle_equal_sign_command {
3750 my $self = shift;
3751
3752 if ($DB::cmd =~ s/\A=\s*//) {
3753 my @keys;
3754 if ( length $DB::cmd == 0 ) {
3755
3756 # No args, get current aliases.
3757 @keys = sort keys %alias;
3758 }
3759 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3760
3761 # Creating a new alias. $k is alias name, $v is
3762 # alias value.
3763
3764 # can't use $_ or kill //g state
3765 for my $x ( $k, $v ) {
3766
3767 # Escape "alarm" characters.
3768 $x =~ s/\a/\\a/g;
3769 }
3770
3771 # Substitute key for value, using alarm chars
3772 # as separators (which is why we escaped them in
3773 # the command).
3774 $alias{$k} = "s\a$k\a$v\a";
3775
3776 # Turn off standard warn and die behavior.
3777 local $SIG{__DIE__};
3778 local $SIG{__WARN__};
3779
3780 # Is it valid Perl?
3781 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3782
3783 # Nope. Bad alias. Say so and get out.
3784 print $OUT "Can't alias $k to $v: $@\n";
3785 delete $alias{$k};
3786 next CMD;
3787 }
3788
3789 # We'll only list the new one.
3790 @keys = ($k);
3791 } ## end elsif (my ($k, $v) = ($DB::cmd...
3792
3793 # The argument is the alias to list.
3794 else {
3795 @keys = ($DB::cmd);