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Refactoring: more renaming and lexicalising.
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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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5
6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
da052516 189The scalar C<${"_<$filename"}> simply contains the string C<$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
SF
646 @options
647 $osingle
648 $otrace
6b24a4b7
SF
649 $pager
650 $post
651 %postponed
652 $prc
653 $pre
654 $pretype
655 $psh
656 @RememberOnROptions
657 $remoteport
658 @res
659 $rl
660 @saved
6b24a4b7 661 $signalLevel
6b24a4b7 662 $sub
6b24a4b7 663 $term
6b24a4b7
SF
664 $usercontext
665 $warnLevel
6b24a4b7
SF
666);
667
0b83f3d9 668our (
2ef1dcdb 669 @cmdfhs,
0b83f3d9
SF
670 $evalarg,
671 $frame,
0664c09a 672 $hist,
0b83f3d9
SF
673 $ImmediateStop,
674 $line,
675 $onetimeDump,
b8d11fe0 676 $onetimedumpDepth,
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 {
cde405a6 869 *share = sub(\[$@%]) {};
2dbd01ad 870 }
2cbb2ee1
RGS
871}
872
2218c045
SF
873# These variables control the execution of 'dumpvar.pl'.
874{
875 package dumpvar;
876 use vars qw(
877 $hashDepth
878 $arrayDepth
879 $dumpDBFiles
880 $dumpPackages
881 $quoteHighBit
882 $printUndef
883 $globPrint
884 $usageOnly
885 );
886}
69893cff 887
2218c045
SF
888# used to control die() reporting in diesignal()
889{
890 package Carp;
891 use vars qw($CarpLevel);
892}
d338d6fe 893
422c59bf 894# without threads, $filename is not defined until DB::DB is called
cde405a6 895share($main::{'_<'.$filename}) if defined $filename;
2cbb2ee1 896
54d04a52 897# Command-line + PERLLIB:
69893cff 898# Save the contents of @INC before they are modified elsewhere.
54d04a52
IZ
899@ini_INC = @INC;
900
69893cff
RGS
901# This was an attempt to clear out the previous values of various
902# trapped errors. Apparently it didn't help. XXX More info needed!
d338d6fe
PP
903# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?!
904
69893cff
RGS
905# We set these variables to safe values. We don't want to blindly turn
906# off warnings, because other packages may still want them.
e22ea7cc
RF
907$trace = $signal = $single = 0; # Uninitialized warning suppression
908 # (local $^W cannot help - other packages!).
69893cff
RGS
909
910# Default to not exiting when program finishes; print the return
911# value when the 'r' command is used to return from a subroutine.
55497cff 912$inhibit_exit = $option{PrintRet} = 1;
d338d6fe 913
6b24a4b7
SF
914use vars qw($trace_to_depth);
915
5e2b42dd
SF
916# Default to 1E9 so it won't be limited to a certain recursion depth.
917$trace_to_depth = 1E9;
bdba49ad 918
69893cff
RGS
919=head1 OPTION PROCESSING
920
b570d64b
SF
921The debugger's options are actually spread out over the debugger itself and
922C<dumpvar.pl>; some of these are variables to be set, while others are
69893cff
RGS
923subs to be called with a value. To try to make this a little easier to
924manage, the debugger uses a few data structures to define what options
925are legal and how they are to be processed.
926
927First, the C<@options> array defines the I<names> of all the options that
928are to be accepted.
929
930=cut
931
932@options = qw(
5561b870 933 CommandSet HistFile HistSize
e22ea7cc
RF
934 hashDepth arrayDepth dumpDepth
935 DumpDBFiles DumpPackages DumpReused
936 compactDump veryCompact quote
937 HighBit undefPrint globPrint
938 PrintRet UsageOnly frame
939 AutoTrace TTY noTTY
940 ReadLine NonStop LineInfo
941 maxTraceLen recallCommand ShellBang
942 pager tkRunning ornaments
943 signalLevel warnLevel dieLevel
944 inhibit_exit ImmediateStop bareStringify
945 CreateTTY RemotePort windowSize
584420f0 946 DollarCaretP
e22ea7cc 947);
d12a4851 948
584420f0 949@RememberOnROptions = qw(DollarCaretP);
d12a4851 950
69893cff
RGS
951=pod
952
953Second, C<optionVars> lists the variables that each option uses to save its
954state.
955
956=cut
957
6b24a4b7
SF
958use vars qw(%optionVars);
959
69893cff 960%optionVars = (
e22ea7cc
RF
961 hashDepth => \$dumpvar::hashDepth,
962 arrayDepth => \$dumpvar::arrayDepth,
963 CommandSet => \$CommandSet,
964 DumpDBFiles => \$dumpvar::dumpDBFiles,
965 DumpPackages => \$dumpvar::dumpPackages,
966 DumpReused => \$dumpvar::dumpReused,
967 HighBit => \$dumpvar::quoteHighBit,
968 undefPrint => \$dumpvar::printUndef,
969 globPrint => \$dumpvar::globPrint,
970 UsageOnly => \$dumpvar::usageOnly,
971 CreateTTY => \$CreateTTY,
972 bareStringify => \$dumpvar::bareStringify,
973 frame => \$frame,
974 AutoTrace => \$trace,
975 inhibit_exit => \$inhibit_exit,
976 maxTraceLen => \$maxtrace,
977 ImmediateStop => \$ImmediateStop,
978 RemotePort => \$remoteport,
979 windowSize => \$window,
5561b870
AK
980 HistFile => \$histfile,
981 HistSize => \$histsize,
69893cff
RGS
982);
983
984=pod
985
986Third, C<%optionAction> defines the subroutine to be called to process each
987option.
988
b570d64b 989=cut
69893cff 990
6b24a4b7
SF
991use vars qw(%optionAction);
992
69893cff
RGS
993%optionAction = (
994 compactDump => \&dumpvar::compactDump,
995 veryCompact => \&dumpvar::veryCompact,
996 quote => \&dumpvar::quote,
997 TTY => \&TTY,
998 noTTY => \&noTTY,
999 ReadLine => \&ReadLine,
1000 NonStop => \&NonStop,
1001 LineInfo => \&LineInfo,
1002 recallCommand => \&recallCommand,
1003 ShellBang => \&shellBang,
1004 pager => \&pager,
1005 signalLevel => \&signalLevel,
1006 warnLevel => \&warnLevel,
1007 dieLevel => \&dieLevel,
1008 tkRunning => \&tkRunning,
1009 ornaments => \&ornaments,
1010 RemotePort => \&RemotePort,
1011 DollarCaretP => \&DollarCaretP,
d12a4851
JH
1012);
1013
69893cff
RGS
1014=pod
1015
1016Last, the C<%optionRequire> notes modules that must be C<require>d if an
1017option is used.
1018
1019=cut
d338d6fe 1020
69893cff
RGS
1021# Note that this list is not complete: several options not listed here
1022# actually require that dumpvar.pl be loaded for them to work, but are
1023# not in the table. A subsequent patch will correct this problem; for
1024# the moment, we're just recommenting, and we are NOT going to change
1025# function.
6b24a4b7
SF
1026use vars qw(%optionRequire);
1027
eda6e075 1028%optionRequire = (
69893cff
RGS
1029 compactDump => 'dumpvar.pl',
1030 veryCompact => 'dumpvar.pl',
1031 quote => 'dumpvar.pl',
e22ea7cc 1032);
69893cff
RGS
1033
1034=pod
1035
1036There are a number of initialization-related variables which can be set
1037by putting code to set them in a BEGIN block in the C<PERL5DB> environment
1038variable. These are:
1039
1040=over 4
1041
1042=item C<$rl> - readline control XXX needs more explanation
1043
1044=item C<$warnLevel> - whether or not debugger takes over warning handling
1045
1046=item C<$dieLevel> - whether or not debugger takes over die handling
1047
1048=item C<$signalLevel> - whether or not debugger takes over signal handling
1049
1050=item C<$pre> - preprompt actions (array reference)
1051
1052=item C<$post> - postprompt actions (array reference)
1053
1054=item C<$pretype>
1055
1056=item C<$CreateTTY> - whether or not to create a new TTY for this debugger
1057
1058=item C<$CommandSet> - which command set to use (defaults to new, documented set)
1059
1060=back
1061
1062=cut
d338d6fe
PP
1063
1064# These guys may be defined in $ENV{PERL5DB} :
69893cff
RGS
1065$rl = 1 unless defined $rl;
1066$warnLevel = 1 unless defined $warnLevel;
1067$dieLevel = 1 unless defined $dieLevel;
1068$signalLevel = 1 unless defined $signalLevel;
1069$pre = [] unless defined $pre;
1070$post = [] unless defined $post;
1071$pretype = [] unless defined $pretype;
1072$CreateTTY = 3 unless defined $CreateTTY;
1073$CommandSet = '580' unless defined $CommandSet;
1074
2cbb2ee1
RGS
1075share($rl);
1076share($warnLevel);
1077share($dieLevel);
1078share($signalLevel);
1079share($pre);
1080share($post);
1081share($pretype);
1082share($rl);
1083share($CreateTTY);
1084share($CommandSet);
1085
69893cff
RGS
1086=pod
1087
1088The default C<die>, C<warn>, and C<signal> handlers are set up.
1089
1090=cut
055fd3a9 1091
d338d6fe
PP
1092warnLevel($warnLevel);
1093dieLevel($dieLevel);
1094signalLevel($signalLevel);
055fd3a9 1095
69893cff
RGS
1096=pod
1097
1098The pager to be used is needed next. We try to get it from the
5561b870 1099environment first. If it's not defined there, we try to find it in
69893cff
RGS
1100the Perl C<Config.pm>. If it's not there, we default to C<more>. We
1101then call the C<pager()> function to save the pager name.
1102
1103=cut
1104
1105# This routine makes sure $pager is set up so that '|' can use it.
4865a36d 1106pager(
e22ea7cc 1107
69893cff 1108 # If PAGER is defined in the environment, use it.
e22ea7cc
RF
1109 defined $ENV{PAGER}
1110 ? $ENV{PAGER}
69893cff
RGS
1111
1112 # If not, see if Config.pm defines it.
e22ea7cc
RF
1113 : eval { require Config }
1114 && defined $Config::Config{pager}
1115 ? $Config::Config{pager}
69893cff
RGS
1116
1117 # If not, fall back to 'more'.
e22ea7cc
RF
1118 : 'more'
1119 )
1120 unless defined $pager;
69893cff
RGS
1121
1122=pod
1123
1124We set up the command to be used to access the man pages, the command
be9a9b1d
AT
1125recall character (C<!> unless otherwise defined) and the shell escape
1126character (C<!> unless otherwise defined). Yes, these do conflict, and
69893cff
RGS
1127neither works in the debugger at the moment.
1128
1129=cut
1130
055fd3a9 1131setman();
69893cff
RGS
1132
1133# Set up defaults for command recall and shell escape (note:
1134# these currently don't work in linemode debugging).
2218c045
SF
1135recallCommand("!") unless defined $prc;
1136shellBang("!") unless defined $psh;
69893cff
RGS
1137
1138=pod
1139
1140We then set up the gigantic string containing the debugger help.
1141We also set the limit on the number of arguments we'll display during a
1142trace.
1143
1144=cut
1145
04e43a21 1146sethelp();
69893cff
RGS
1147
1148# If we didn't get a default for the length of eval/stack trace args,
1149# set it here.
1d06cb2d 1150$maxtrace = 400 unless defined $maxtrace;
69893cff
RGS
1151
1152=head2 SETTING UP THE DEBUGGER GREETING
1153
be9a9b1d 1154The debugger I<greeting> helps to inform the user how many debuggers are
69893cff
RGS
1155running, and whether the current debugger is the primary or a child.
1156
1157If we are the primary, we just hang onto our pid so we'll have it when
1158or if we start a child debugger. If we are a child, we'll set things up
1159so we'll have a unique greeting and so the parent will give us our own
1160TTY later.
1161
1162We save the current contents of the C<PERLDB_PIDS> environment variable
1163because we mess around with it. We'll also need to hang onto it because
1164we'll need it if we restart.
1165
1166Child debuggers make a label out of the current PID structure recorded in
1167PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY
1168yet so the parent will give them one later via C<resetterm()>.
1169
1170=cut
1171
e22ea7cc 1172# Save the current contents of the environment; we're about to
69893cff 1173# much with it. We'll need this if we have to restart.
6b24a4b7 1174use vars qw($ini_pids);
f1583d8f 1175$ini_pids = $ENV{PERLDB_PIDS};
69893cff 1176
6b24a4b7
SF
1177use vars qw ($pids $term_pid);
1178
e22ea7cc
RF
1179if ( defined $ENV{PERLDB_PIDS} ) {
1180
69893cff 1181 # We're a child. Make us a label out of the current PID structure
e22ea7cc 1182 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having
69893cff 1183 # a term yet so the parent will give us one later via resetterm().
55f4245e
JM
1184
1185 my $env_pids = $ENV{PERLDB_PIDS};
1186 $pids = "[$env_pids]";
1187
1188 # Unless we are on OpenVMS, all programs under the DCL shell run under
1189 # the same PID.
1190
1191 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) {
1192 $term_pid = $$;
1193 }
1194 else {
1195 $ENV{PERLDB_PIDS} .= "->$$";
1196 $term_pid = -1;
1197 }
1198
69893cff
RGS
1199} ## end if (defined $ENV{PERLDB_PIDS...
1200else {
e22ea7cc
RF
1201
1202 # We're the parent PID. Initialize PERLDB_PID in case we end up with a
69893cff
RGS
1203 # child debugger, and mark us as the parent, so we'll know to set up
1204 # more TTY's is we have to.
1205 $ENV{PERLDB_PIDS} = "$$";
619a0444 1206 $pids = "[pid=$$]";
e22ea7cc 1207 $term_pid = $$;
f1583d8f 1208}
69893cff 1209
6b24a4b7 1210use vars qw($pidprompt);
f1583d8f 1211$pidprompt = '';
69893cff
RGS
1212
1213# Sets up $emacs as a synonym for $slave_editor.
7793e5c2 1214our ($slave_editor);
69893cff
RGS
1215*emacs = $slave_editor if $slave_editor; # May be used in afterinit()...
1216
1217=head2 READING THE RC FILE
1218
b570d64b 1219The debugger will read a file of initialization options if supplied. If
69893cff
RGS
1220running interactively, this is C<.perldb>; if not, it's C<perldb.ini>.
1221
b570d64b 1222=cut
69893cff
RGS
1223
1224# As noted, this test really doesn't check accurately that the debugger
1225# is running at a terminal or not.
d338d6fe 1226
6b24a4b7 1227use vars qw($rcfile);
fb4d8a6c
SF
1228{
1229 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty');
1230 # this is the wrong metric!
1231 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini");
d338d6fe
PP
1232}
1233
69893cff
RGS
1234=pod
1235
1236The debugger does a safety test of the file to be read. It must be owned
1237either by the current user or root, and must only be writable by the owner.
1238
1239=cut
1240
1241# This wraps a safety test around "do" to read and evaluate the init file.
1242#
055fd3a9
GS
1243# This isn't really safe, because there's a race
1244# between checking and opening. The solution is to
1245# open and fstat the handle, but then you have to read and
1246# eval the contents. But then the silly thing gets
69893cff
RGS
1247# your lexical scope, which is unfortunate at best.
1248sub safe_do {
055fd3a9
GS
1249 my $file = shift;
1250
1251 # Just exactly what part of the word "CORE::" don't you understand?
69893cff
RGS
1252 local $SIG{__WARN__};
1253 local $SIG{__DIE__};
055fd3a9 1254
e22ea7cc 1255 unless ( is_safe_file($file) ) {
69893cff 1256 CORE::warn <<EO_GRIPE;
055fd3a9 1257perldb: Must not source insecure rcfile $file.
b570d64b 1258 You or the superuser must be the owner, and it must not
69893cff 1259 be writable by anyone but its owner.
055fd3a9 1260EO_GRIPE
69893cff
RGS
1261 return;
1262 } ## end unless (is_safe_file($file...
055fd3a9
GS
1263
1264 do $file;
1265 CORE::warn("perldb: couldn't parse $file: $@") if $@;
69893cff 1266} ## end sub safe_do
055fd3a9 1267
69893cff
RGS
1268# This is the safety test itself.
1269#
055fd3a9
GS
1270# Verifies that owner is either real user or superuser and that no
1271# one but owner may write to it. This function is of limited use
1272# when called on a path instead of upon a handle, because there are
1273# no guarantees that filename (by dirent) whose file (by ino) is
e22ea7cc 1274# eventually accessed is the same as the one tested.
055fd3a9
GS
1275# Assumes that the file's existence is not in doubt.
1276sub is_safe_file {
1277 my $path = shift;
69893cff 1278 stat($path) || return; # mysteriously vaporized
e22ea7cc 1279 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_);
055fd3a9
GS
1280
1281 return 0 if $uid != 0 && $uid != $<;
1282 return 0 if $mode & 022;
1283 return 1;
69893cff 1284} ## end sub is_safe_file
055fd3a9 1285
69893cff 1286# If the rcfile (whichever one we decided was the right one to read)
e22ea7cc
RF
1287# exists, we safely do it.
1288if ( -f $rcfile ) {
055fd3a9 1289 safe_do("./$rcfile");
69893cff 1290}
e22ea7cc 1291
69893cff 1292# If there isn't one here, try the user's home directory.
e22ea7cc 1293elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) {
055fd3a9
GS
1294 safe_do("$ENV{HOME}/$rcfile");
1295}
e22ea7cc 1296
69893cff 1297# Else try the login directory.
e22ea7cc 1298elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) {
055fd3a9 1299 safe_do("$ENV{LOGDIR}/$rcfile");
d338d6fe
PP
1300}
1301
69893cff 1302# If the PERLDB_OPTS variable has options in it, parse those out next.
e22ea7cc
RF
1303if ( defined $ENV{PERLDB_OPTS} ) {
1304 parse_options( $ENV{PERLDB_OPTS} );
d338d6fe
PP
1305}
1306
69893cff
RGS
1307=pod
1308
1309The last thing we do during initialization is determine which subroutine is
1310to be used to obtain a new terminal when a new debugger is started. Right now,
b0b54b5e 1311the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X
11653f7f 1312(darwin).
69893cff
RGS
1313
1314=cut
1315
1316# Set up the get_fork_TTY subroutine to be aliased to the proper routine.
1317# Works if you're running an xterm or xterm-like window, or you're on
6fae1ad7
RF
1318# OS/2, or on Mac OS X. This may need some expansion.
1319
1320if (not defined &get_fork_TTY) # only if no routine exists
69893cff 1321{
b570d64b 1322 if ( defined $remoteport ) {
11653f7f
JJ
1323 # Expect an inetd-like server
1324 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us
1325 }
1326 elsif (defined $ENV{TERM} # If we know what kind
6fae1ad7
RF
1327 # of terminal this is,
1328 and $ENV{TERM} eq 'xterm' # and it's an xterm,
1329 and defined $ENV{DISPLAY} # and what display it's on,
1330 )
1331 {
1332 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version
1333 }
1334 elsif ( $^O eq 'os2' ) { # If this is OS/2,
1335 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version
1336 }
1337 elsif ( $^O eq 'darwin' # If this is Mac OS X
1338 and defined $ENV{TERM_PROGRAM} # and we're running inside
1339 and $ENV{TERM_PROGRAM}
1340 eq 'Apple_Terminal' # Terminal.app
1341 )
1342 {
1343 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version
1344 }
69893cff 1345} ## end if (not defined &get_fork_TTY...
e22ea7cc 1346
dbb46cec
DQ
1347# untaint $^O, which may have been tainted by the last statement.
1348# see bug [perl #24674]
e22ea7cc
RF
1349$^O =~ m/^(.*)\z/;
1350$^O = $1;
f1583d8f 1351
d12a4851 1352# Here begin the unreadable code. It needs fixing.
055fd3a9 1353
69893cff
RGS
1354=head2 RESTART PROCESSING
1355
1356This section handles the restart command. When the C<R> command is invoked, it
1357tries to capture all of the state it can into environment variables, and
1358then sets C<PERLDB_RESTART>. When we start executing again, we check to see
1359if C<PERLDB_RESTART> is there; if so, we reload all the information that
1360the R command stuffed into the environment variables.
1361
b570d64b 1362 PERLDB_RESTART - flag only, contains no restart data itself.
69893cff
RGS
1363 PERLDB_HIST - command history, if it's available
1364 PERLDB_ON_LOAD - breakpoints set by the rc file
1365 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions
1366 PERLDB_VISITED - files that had breakpoints
1367 PERLDB_FILE_... - breakpoints for a file
1368 PERLDB_OPT - active options
1369 PERLDB_INC - the original @INC
1370 PERLDB_PRETYPE - preprompt debugger actions
1371 PERLDB_PRE - preprompt Perl code
1372 PERLDB_POST - post-prompt Perl code
1373 PERLDB_TYPEAHEAD - typeahead captured by readline()
1374
1375We chug through all these variables and plug the values saved in them
1376back into the appropriate spots in the debugger.
1377
1378=cut
1379
0664c09a 1380use vars qw(%postponed_file @typeahead);
14f38b27 1381
0664c09a 1382our (@hist, @truehist);
6b24a4b7 1383
fb0fb5f4
SF
1384sub _restore_shared_globals_after_restart
1385{
1386 @hist = get_list('PERLDB_HIST');
1387 %break_on_load = get_list("PERLDB_ON_LOAD");
1388 %postponed = get_list("PERLDB_POSTPONE");
1389
1390 share(@hist);
1391 share(@truehist);
1392 share(%break_on_load);
1393 share(%postponed);
1394}
1395
e18a02a6 1396sub _restore_breakpoints_and_actions {
e22ea7cc 1397
e22ea7cc 1398 my @had_breakpoints = get_list("PERLDB_VISITED");
e18a02a6 1399
bdba49ad
SF
1400 for my $file_idx ( 0 .. $#had_breakpoints ) {
1401 my $filename = $had_breakpoints[$file_idx];
1402 my %pf = get_list("PERLDB_FILE_$file_idx");
1403 $postponed_file{ $filename } = \%pf if %pf;
1404 my @lines = sort {$a <=> $b} keys(%pf);
1405 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx");
1406 for my $line_idx (0 .. $#lines) {
1407 _set_breakpoint_enabled_status(
1408 $filename,
1409 $lines[$line_idx],
1410 ($enabled_statuses[$line_idx] ? 1 : ''),
1411 );
1412 }
e22ea7cc 1413 }
69893cff 1414
e18a02a6
SF
1415 return;
1416}
1417
ca50076b
SF
1418sub _restore_options_after_restart
1419{
1420 my %options_map = get_list("PERLDB_OPT");
1421
1422 while ( my ( $opt, $val ) = each %options_map ) {
1423 $val =~ s/[\\\']/\\$1/g;
1424 parse_options("$opt'$val'");
1425 }
1426
1427 return;
1428}
1429
18580168
SF
1430sub _restore_globals_after_restart
1431{
1432 # restore original @INC
1433 @INC = get_list("PERLDB_INC");
1434 @ini_INC = @INC;
1435
1436 # return pre/postprompt actions and typeahead buffer
1437 $pretype = [ get_list("PERLDB_PRETYPE") ];
1438 $pre = [ get_list("PERLDB_PRE") ];
1439 $post = [ get_list("PERLDB_POST") ];
1440 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead );
1441
1442 return;
1443}
1444
fb0fb5f4 1445
e18a02a6
SF
1446if ( exists $ENV{PERLDB_RESTART} ) {
1447
1448 # We're restarting, so we don't need the flag that says to restart anymore.
1449 delete $ENV{PERLDB_RESTART};
1450
1451 # $restart = 1;
fb0fb5f4 1452 _restore_shared_globals_after_restart();
e18a02a6
SF
1453
1454 _restore_breakpoints_and_actions();
1455
69893cff 1456 # restore options
ca50076b 1457 _restore_options_after_restart();
69893cff 1458
18580168 1459 _restore_globals_after_restart();
69893cff
RGS
1460} ## end if (exists $ENV{PERLDB_RESTART...
1461
1462=head2 SETTING UP THE TERMINAL
1463
1464Now, we'll decide how the debugger is going to interact with the user.
1465If there's no TTY, we set the debugger to run non-stop; there's not going
1466to be anyone there to enter commands.
1467
1468=cut
54d04a52 1469
ebd0282e 1470use vars qw($notty $console $tty $LINEINFO);
6b24a4b7
SF
1471use vars qw($lineinfo $doccmd);
1472
ebd0282e
SF
1473our ($runnonstop);
1474
d338d6fe 1475if ($notty) {
69893cff 1476 $runnonstop = 1;
2dbd01ad 1477 share($runnonstop);
69893cff 1478}
d12a4851 1479
69893cff
RGS
1480=pod
1481
1482If there is a TTY, we have to determine who it belongs to before we can
1483proceed. If this is a slave editor or graphical debugger (denoted by
1484the first command-line switch being '-emacs'), we shift this off and
1485set C<$rl> to 0 (XXX ostensibly to do straight reads).
1486
1487=cut
1488
1489else {
e22ea7cc 1490
69893cff
RGS
1491 # Is Perl being run from a slave editor or graphical debugger?
1492 # If so, don't use readline, and set $slave_editor = 1.
2b0b9dd1
SF
1493 if ($slave_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) {
1494 $rl = 0;
1495 shift(@main::ARGV);
1496 }
e22ea7cc
RF
1497
1498 #require Term::ReadLine;
d12a4851 1499
69893cff
RGS
1500=pod
1501
1502We then determine what the console should be on various systems:
1503
1504=over 4
1505
1506=item * Cygwin - We use C<stdin> instead of a separate device.
1507
1508=cut
1509
e22ea7cc
RF
1510 if ( $^O eq 'cygwin' ) {
1511
69893cff
RGS
1512 # /dev/tty is binary. use stdin for textmode
1513 undef $console;
1514 }
1515
1516=item * Unix - use C</dev/tty>.
1517
1518=cut
1519
e22ea7cc 1520 elsif ( -e "/dev/tty" ) {
69893cff
RGS
1521 $console = "/dev/tty";
1522 }
1523
1524=item * Windows or MSDOS - use C<con>.
1525
1526=cut
1527
e22ea7cc 1528 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) {
69893cff
RGS
1529 $console = "con";
1530 }
1531
69893cff
RGS
1532=item * VMS - use C<sys$command>.
1533
1534=cut
1535
1536 else {
e22ea7cc 1537
69893cff
RGS
1538 # everything else is ...
1539 $console = "sys\$command";
d12a4851 1540 }
69893cff
RGS
1541
1542=pod
1543
1544=back
1545
1546Several other systems don't use a specific console. We C<undef $console>
1547for those (Windows using a slave editor/graphical debugger, NetWare, OS/2
1548with a slave editor, Epoc).
1549
1550=cut
d12a4851 1551
e22ea7cc
RF
1552 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) {
1553
69893cff 1554 # /dev/tty is binary. use stdin for textmode
e22ea7cc
RF
1555 $console = undef;
1556 }
1557
1558 if ( $^O eq 'NetWare' ) {
d12a4851 1559
69893cff
RGS
1560 # /dev/tty is binary. use stdin for textmode
1561 $console = undef;
1562 }
d12a4851 1563
69893cff
RGS
1564 # In OS/2, we need to use STDIN to get textmode too, even though
1565 # it pretty much looks like Unix otherwise.
e22ea7cc
RF
1566 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) )
1567 { # In OS/2
1568 $console = undef;
1569 }
1570
1571 # EPOC also falls into the 'got to use STDIN' camp.
1572 if ( $^O eq 'epoc' ) {
1573 $console = undef;
1574 }
d12a4851 1575
69893cff
RGS
1576=pod
1577
1578If there is a TTY hanging around from a parent, we use that as the console.
1579
1580=cut
1581
e22ea7cc 1582 $console = $tty if defined $tty;
d12a4851 1583
b570d64b 1584=head2 SOCKET HANDLING
69893cff
RGS
1585
1586The debugger is capable of opening a socket and carrying out a debugging
1587session over the socket.
1588
1589If C<RemotePort> was defined in the options, the debugger assumes that it
1590should try to start a debugging session on that port. It builds the socket
1591and then tries to connect the input and output filehandles to it.
1592
1593=cut
1594
1595 # Handle socket stuff.
e22ea7cc
RF
1596
1597 if ( defined $remoteport ) {
1598
69893cff
RGS
1599 # If RemotePort was defined in the options, connect input and output
1600 # to the socket.
11653f7f 1601 $IN = $OUT = connect_remoteport();
69893cff
RGS
1602 } ## end if (defined $remoteport)
1603
1604=pod
1605
1606If no C<RemotePort> was defined, and we want to create a TTY on startup,
1607this is probably a situation where multiple debuggers are running (for example,
1608a backticked command that starts up another debugger). We create a new IN and
1609OUT filehandle, and do the necessary mojo to create a new TTY if we know how
1610and if we can.
1611
1612=cut
1613
1614 # Non-socket.
1615 else {
e22ea7cc 1616
69893cff
RGS
1617 # Two debuggers running (probably a system or a backtick that invokes
1618 # the debugger itself under the running one). create a new IN and OUT
e22ea7cc 1619 # filehandle, and do the necessary mojo to create a new tty if we
69893cff 1620 # know how, and we can.
e22ea7cc
RF
1621 create_IN_OUT(4) if $CreateTTY & 4;
1622 if ($console) {
1623
69893cff 1624 # If we have a console, check to see if there are separate ins and
cd1191f1 1625 # outs to open. (They are assumed identical if not.)
69893cff 1626
e22ea7cc
RF
1627 my ( $i, $o ) = split /,/, $console;
1628 $o = $i unless defined $o;
69893cff 1629
69893cff 1630 # read/write on in, or just read, or read on STDIN.
e22ea7cc
RF
1631 open( IN, "+<$i" )
1632 || open( IN, "<$i" )
1633 || open( IN, "<&STDIN" );
1634
69893cff
RGS
1635 # read/write/create/clobber out, or write/create/clobber out,
1636 # or merge with STDERR, or merge with STDOUT.
e22ea7cc
RF
1637 open( OUT, "+>$o" )
1638 || open( OUT, ">$o" )
1639 || open( OUT, ">&STDERR" )
1640 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1641
1642 } ## end if ($console)
1643 elsif ( not defined $console ) {
1644
1645 # No console. Open STDIN.
1646 open( IN, "<&STDIN" );
1647
1648 # merge with STDERR, or with STDOUT.
1649 open( OUT, ">&STDERR" )
1650 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout
1651 $console = 'STDIN/OUT';
69893cff
RGS
1652 } ## end elsif (not defined $console)
1653
1654 # Keep copies of the filehandles so that when the pager runs, it
1655 # can close standard input without clobbering ours.
2b0b9dd1
SF
1656 if ($console or (not defined($console))) {
1657 $IN = \*IN;
1658 $OUT = \*OUT;
1659 }
e22ea7cc
RF
1660 } ## end elsif (from if(defined $remoteport))
1661
1662 # Unbuffer DB::OUT. We need to see responses right away.
70c9432b 1663 $OUT->autoflush(1);
e22ea7cc
RF
1664
1665 # Line info goes to debugger output unless pointed elsewhere.
1666 # Pointing elsewhere makes it possible for slave editors to
1667 # keep track of file and position. We have both a filehandle
1668 # and a I/O description to keep track of.
1669 $LINEINFO = $OUT unless defined $LINEINFO;
1670 $lineinfo = $console unless defined $lineinfo;
2dbd01ad
SF
1671 # share($LINEINFO); # <- unable to share globs
1672 share($lineinfo); #
e22ea7cc 1673
69893cff
RGS
1674=pod
1675
1676To finish initialization, we show the debugger greeting,
1677and then call the C<afterinit()> subroutine if there is one.
1678
1679=cut
d12a4851 1680
e22ea7cc
RF
1681 # Show the debugger greeting.
1682 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/;
1683 unless ($runnonstop) {
1684 local $\ = '';
1685 local $, = '';
1686 if ( $term_pid eq '-1' ) {
1687 print $OUT "\nDaughter DB session started...\n";
1688 }
1689 else {
1690 print $OUT "\nLoading DB routines from $header\n";
1691 print $OUT (
1692 "Editor support ",
1693 $slave_editor ? "enabled" : "available", ".\n"
1694 );
1695 print $OUT
1f874cb6 1696"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n";
69893cff
RGS
1697 } ## end else [ if ($term_pid eq '-1')
1698 } ## end unless ($runnonstop)
1699} ## end else [ if ($notty)
1700
1701# XXX This looks like a bug to me.
1702# Why copy to @ARGS and then futz with @args?
d338d6fe 1703@ARGS = @ARGV;
6b24a4b7 1704# for (@args) {
69893cff
RGS
1705 # Make sure backslashes before single quotes are stripped out, and
1706 # keep args unless they are numeric (XXX why?)
e22ea7cc
RF
1707 # s/\'/\\\'/g; # removed while not justified understandably
1708 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto
6b24a4b7 1709# }
d338d6fe 1710
e22ea7cc 1711# If there was an afterinit() sub defined, call it. It will get
69893cff 1712# executed in our scope, so it can fiddle with debugger globals.
e22ea7cc 1713if ( defined &afterinit ) { # May be defined in $rcfile
2b0b9dd1 1714 afterinit();
d338d6fe 1715}
e22ea7cc 1716
69893cff 1717# Inform us about "Stack dump during die enabled ..." in dieLevel().
6b24a4b7
SF
1718use vars qw($I_m_init);
1719
43aed9ee
IZ
1720$I_m_init = 1;
1721
d338d6fe
PP
1722############################################################ Subroutines
1723
69893cff
RGS
1724=head1 SUBROUTINES
1725
1726=head2 DB
1727
1728This gigantic subroutine is the heart of the debugger. Called before every
1729statement, its job is to determine if a breakpoint has been reached, and
1730stop if so; read commands from the user, parse them, and execute
b468dcb6 1731them, and then send execution off to the next statement.
69893cff
RGS
1732
1733Note that the order in which the commands are processed is very important;
1734some commands earlier in the loop will actually alter the C<$cmd> variable
be9a9b1d 1735to create other commands to be executed later. This is all highly I<optimized>
69893cff
RGS
1736but can be confusing. Check the comments for each C<$cmd ... && do {}> to
1737see what's happening in any given command.
1738
1739=cut
1740
136ae23d
SF
1741# $cmd cannot be an our() variable unfortunately (possible perl bug?).
1742
6b24a4b7
SF
1743use vars qw(
1744 $action
6b24a4b7 1745 $cmd
6b24a4b7
SF
1746 $file
1747 $filename_ini
1748 $finished
1749 %had_breakpoints
6b24a4b7
SF
1750 $level
1751 $max
6b24a4b7 1752 $package
6b24a4b7
SF
1753 $try
1754);
1755
1ce985d2 1756our (
bdb3f37d 1757 %alias,
1ce985d2 1758 $doret,
0664c09a 1759 $end,
4d0e1f38 1760 $fall_off_end,
d1450c23 1761 $incr,
73c5e526 1762 $laststep,
14f38b27 1763 $rc,
ddf4cf26 1764 $sh,
1ce985d2
SF
1765 $stack_depth,
1766 @stack,
1767 @to_watch,
1768 @old_watch,
1769);
8ad70697 1770
6791e41b
SF
1771sub _DB__determine_if_we_should_break
1772{
1773 # if we have something here, see if we should break.
1774 # $stop is lexical and local to this block - $action on the other hand
1775 # is global.
1776 my $stop;
1777
1778 if ( $dbline{$line}
1779 && _is_breakpoint_enabled($filename, $line)
1780 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) )
1781 {
1782
1783 # Stop if the stop criterion says to just stop.
1784 if ( $stop eq '1' ) {
1785 $signal |= 1;
1786 }
1787
1788 # It's a conditional stop; eval it in the user's context and
1789 # see if we should stop. If so, remove the one-time sigil.
1790 elsif ($stop) {
1791 $evalarg = "\$DB::signal |= 1 if do {$stop}";
6cff0f90 1792 DB::eval();
6791e41b
SF
1793 # If the breakpoint is temporary, then delete its enabled status.
1794 if ($dbline{$line} =~ s/;9($|\0)/$1/) {
1795 _cancel_breakpoint_temp_enabled_status($filename, $line);
1796 }
1797 }
1798 } ## end if ($dbline{$line} && ...
1799}
1800
8481f647
SF
1801sub _DB__is_finished {
1802 if ($finished and $level <= 1) {
1803 end_report();
1804 return 1;
1805 }
1806 else {
1807 return;
1808 }
1809}
1810
32bbadc6
SF
1811sub _DB__read_next_cmd
1812{
1813 my ($tid) = @_;
1814
1815 # We have a terminal, or can get one ...
1816 if (!$term) {
1817 setterm();
1818 }
1819
1820 # ... and it belogs to this PID or we get one for this PID ...
1821 if ($term_pid != $$) {
1822 resetterm(1);
1823 }
1824
1825 # ... and we got a line of command input ...
1826 $cmd = DB::readline(
1827 "$pidprompt $tid DB"
1828 . ( '<' x $level )
1829 . ( $#hist + 1 )
1830 . ( '>' x $level ) . " "
1831 );
1832
1833 return defined($cmd);
1834}
1835
7013f40c 1836sub _DB__trim_command_and_return_first_component {
af84fb69
SF
1837 my ($obj) = @_;
1838
7013f40c
SF
1839 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace
1840 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace
1841
1842 $cmd =~ m{\A(\S*)};
af84fb69 1843
610f01b9 1844 $obj->cmd_verb($1);
af84fb69
SF
1845
1846 return;
7013f40c
SF
1847}
1848
2a802473
SF
1849sub _DB__handle_f_command {
1850 if (($file) = $cmd =~ /\Af\b\s*(.*)/) {
1851 $file =~ s/\s+$//;
1852
1853 # help for no arguments (old-style was return from sub).
1854 if ( !$file ) {
1855 print $OUT
1856 "The old f command is now the r command.\n"; # hint
1857 print $OUT "The new f command switches filenames.\n";
1858 next CMD;
1859 } ## end if (!$file)
1860
1861 # if not in magic file list, try a close match.
1862 if ( !defined $main::{ '_<' . $file } ) {
1863 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) {
1864 {
1865 $try = substr( $try, 2 );
1866 print $OUT "Choosing $try matching '$file':\n";
1867 $file = $try;
1868 }
1869 } ## end if (($try) = grep(m#^_<.*$file#...
1870 } ## end if (!defined $main::{ ...
1871
1872 # If not successfully switched now, we failed.
1873 if ( !defined $main::{ '_<' . $file } ) {
1874 print $OUT "No file matching '$file' is loaded.\n";
1875 next CMD;
1876 }
1877
1878 # We switched, so switch the debugger internals around.
1879 elsif ( $file ne $filename ) {
1880 *dbline = $main::{ '_<' . $file };
1881 $max = $#dbline;
1882 $filename = $file;
1883 $start = 1;
1884 $cmd = "l";
1885 } ## end elsif ($file ne $filename)
1886
1887 # We didn't switch; say we didn't.
1888 else {
1889 print $OUT "Already in $file.\n";
1890 next CMD;
1891 }
1892 }
1893
1894 return;
1895}
1896
6115a173
SF
1897sub _DB__handle_dot_command {
1898 my ($obj) = @_;
1899
1900 # . command.
1901 if ($cmd eq '.') {
1902 $incr = -1; # stay at current line
1903
1904 # Reset everything to the old location.
1905 $start = $line;
1906 $filename = $filename_ini;
1907 *dbline = $main::{ '_<' . $filename };
1908 $max = $#dbline;
1909
1910 # Now where are we?
1911 print_lineinfo($obj->position());
1912 next CMD;
1913 }
1914
1915 return;
1916}
1917
5c2b78e7
SF
1918sub _DB__handle_y_command {
1919 my ($obj) = @_;
1920
1921 if (my ($match_level, $match_vars)
1922 = $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/) {
1923
1924 # See if we've got the necessary support.
84e7f475
SF
1925 if (!eval { require PadWalker; PadWalker->VERSION(0.08) }) {
1926 my $Err = $@;
1927 DB::warn(
1928 $Err =~ /locate/
1929 ? "PadWalker module not found - please install\n"
1930 : $Err
1931 );
1932 next CMD;
1933 }
5c2b78e7
SF
1934
1935 # Load up dumpvar if we don't have it. If we can, that is.
1936 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
1937 defined &main::dumpvar
1938 or print $OUT "dumpvar.pl not available.\n"
1939 and next CMD;
1940
1941 # Got all the modules we need. Find them and print them.
1942 my @vars = split( ' ', $match_vars || '' );
1943
1944 # Find the pad.
1945 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 1 ) };
1946
1947 # Oops. Can't find it.
84e7f475
SF
1948 if (my $Err = $@) {
1949 $Err =~ s/ at .*//;
1950 DB::warn($Err);
1951 next CMD;
1952 }
5c2b78e7
SF
1953
1954 # Show the desired vars with dumplex().
1955 my $savout = select($OUT);
1956
1957 # Have dumplex dump the lexicals.
84e7f475
SF
1958 foreach my $key (sort keys %$h) {
1959 dumpvar::dumplex( $key, $h->{$key},
1960 defined $option{dumpDepth} ? $option{dumpDepth} : -1,
1961 @vars );
1962 }
5c2b78e7
SF
1963 select($savout);
1964 next CMD;
1965 }
1966}
1967
35cd713a
SF
1968sub _DB__handle_c_command {
1969 my ($obj) = @_;
1970
9c6fceaf 1971 if (my ($new_verb) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
35cd713a 1972
9c6fceaf 1973 $obj->cmd_verb($new_verb);
35cd713a
SF
1974
1975 # Hey, show's over. The debugged program finished
1976 # executing already.
1977 next CMD if _DB__is_finished();
1978
1979 # Capture the place to put a one-time break.
610f01b9 1980 $subname = $obj->cmd_verb;
35cd713a
SF
1981
1982 # Probably not needed, since we finish an interactive
1983 # sub-session anyway...
1984 # local $filename = $filename;
1985 # local *dbline = *dbline; # XXX Would this work?!
1986 #
1987 # The above question wonders if localizing the alias
1988 # to the magic array works or not. Since it's commented
1989 # out, we'll just leave that to speculation for now.
1990
1991 # If the "subname" isn't all digits, we'll assume it
1992 # is a subroutine name, and try to find it.
1993 if ( $subname =~ /\D/ ) { # subroutine name
1994 # Qualify it to the current package unless it's
1995 # already qualified.
1996 $subname = $package . "::" . $subname
1997 unless $subname =~ /::/;
1998
1999 # find_sub will return "file:line_number" corresponding
2000 # to where the subroutine is defined; we call find_sub,
2001 # break up the return value, and assign it in one
2002 # operation.
9c6fceaf 2003 ( $file, $new_verb ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
35cd713a
SF
2004
2005 # Force the line number to be numeric.
9c6fceaf 2006 $obj->cmd_verb($new_verb + 0);
35cd713a
SF
2007
2008 # If we got a line number, we found the sub.
610f01b9 2009 if ($obj->cmd_verb) {
35cd713a
SF
2010
2011 # Switch all the debugger's internals around so
2012 # we're actually working with that file.
2013 $filename = $file;
2014 *dbline = $main::{ '_<' . $filename };
2015
2016 # Mark that there's a breakpoint in this file.
2017 $had_breakpoints{$filename} |= 1;
2018
2019 # Scan forward to the first executable line
2020 # after the 'sub whatever' line.
2021 $max = $#dbline;
9c6fceaf
SF
2022 my $_line_num = $obj->cmd_verb;
2023 while ($dbline[$_line_num] == 0 && $_line_num< $max)
2024 {
2025 $_line_num++;
2026 }
2027 $obj->cmd_verb($_line_num);
35cd713a
SF
2028 } ## end if ($i)
2029
2030 # We didn't find a sub by that name.
2031 else {
2032 print $OUT "Subroutine $subname not found.\n";
2033 next CMD;
2034 }
2035 } ## end if ($subname =~ /\D/)
2036
2037 # At this point, either the subname was all digits (an
2038 # absolute line-break request) or we've scanned through
2039 # the code following the definition of the sub, looking
2040 # for an executable, which we may or may not have found.
2041 #
2042 # If $i (which we set $subname from) is non-zero, we
2043 # got a request to break at some line somewhere. On
2044 # one hand, if there wasn't any real subroutine name
2045 # involved, this will be a request to break in the current
2046 # file at the specified line, so we have to check to make
2047 # sure that the line specified really is breakable.
2048 #
2049 # On the other hand, if there was a subname supplied, the
2050 # preceding block has moved us to the proper file and
2051 # location within that file, and then scanned forward
2052 # looking for the next executable line. We have to make
2053 # sure that one was found.
2054 #
2055 # On the gripping hand, we can't do anything unless the
2056 # current value of $i points to a valid breakable line.
2057 # Check that.
610f01b9 2058 if ($obj->cmd_verb) {
35cd713a
SF
2059
2060 # Breakable?
610f01b9
SF
2061 if ( $dbline[$obj->cmd_verb] == 0 ) {
2062 print $OUT "Line " . $obj->cmd_verb . " not breakable.\n";
35cd713a
SF
2063 next CMD;
2064 }
2065
2066 # Yes. Set up the one-time-break sigil.
610f01b9
SF
2067 $dbline{$obj->cmd_verb} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2068 _enable_breakpoint_temp_enabled_status($filename, $obj->cmd_verb);
35cd713a
SF
2069 } ## end if ($i)
2070
2071 # Turn off stack tracing from here up.
2072 for my $i (0 .. $stack_depth) {
2073 $stack[ $i ] &= ~1;
2074 }
2075 last CMD;
2076 }
2077
2078 return;
2079}
2080
a4d311a3
SF
2081sub _DB__handle_forward_slash_command {
2082 my ($obj) = @_;
2083
2084 # The pattern as a string.
2085 use vars qw($inpat);
2086
2087 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2088
2089 # Remove the final slash.
2090 $inpat =~ s:([^\\])/$:$1:;
2091
2092 # If the pattern isn't null ...
2093 if ( $inpat ne "" ) {
2094
2095 # Turn of warn and die procesing for a bit.
2096 local $SIG{__DIE__};
2097 local $SIG{__WARN__};
2098
2099 # Create the pattern.
2100 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2101 if ( $@ ne "" ) {
2102
2103 # Oops. Bad pattern. No biscuit.
2104 # Print the eval error and go back for more
2105 # commands.
2106 print $OUT "$@";
2107 next CMD;
2108 }
2109 $obj->pat($inpat);
2110 } ## end if ($inpat ne "")
2111
2112 # Set up to stop on wrap-around.
2113 $end = $start;
2114
2115 # Don't move off the current line.
2116 $incr = -1;
2117
2118 my $pat = $obj->pat;
2119
2120 # Done in eval so nothing breaks if the pattern
2121 # does something weird.
2122 eval
2123 {
2124 no strict q/vars/;
2125 for (;;) {
2126 # Move ahead one line.
2127 ++$start;
2128
2129 # Wrap if we pass the last line.
2130 $start = 1 if ($start > $max);
2131
2132 # Stop if we have gotten back to this line again,
2133 last if ($start == $end);
2134
2135 # A hit! (Note, though, that we are doing
2136 # case-insensitive matching. Maybe a qr//
2137 # expression would be better, so the user could
2138 # do case-sensitive matching if desired.
2139 if ($dbline[$start] =~ m/$pat/i) {
2140 if ($slave_editor) {
2141 # Handle proper escaping in the slave.
2142 print $OUT "\032\032$filename:$start:0\n";
2143 }
2144 else {
2145 # Just print the line normally.
2146 print $OUT "$start:\t",$dbline[$start],"\n";
2147 }
2148 # And quit since we found something.
2149 last;
2150 }
2151 }
2152 };
2153
2154 if ($@) {
2155 warn $@;
2156 }
2157
2158 # If we wrapped, there never was a match.
2159 if ( $start == $end ) {
2160 print {$OUT} "/$pat/: not found\n";
2161 }
2162 next CMD;
2163 }
2164
2165 return;
2166}
2167
11f0f050
SF
2168sub _DB__handle_question_mark_command {
2169 my ($obj) = @_;
2170
2171 # ? - backward pattern search.
2172 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2173
2174 # Get the pattern, remove trailing question mark.
2175 $inpat =~ s:([^\\])\?$:$1:;
2176
2177 # If we've got one ...
2178 if ( $inpat ne "" ) {
2179
2180 # Turn off die & warn handlers.
2181 local $SIG{__DIE__};
2182 local $SIG{__WARN__};
2183 eval '$inpat =~ m' . "\a$inpat\a";
2184
2185 if ( $@ ne "" ) {
2186
2187 # Ouch. Not good. Print the error.
2188 print $OUT $@;
2189 next CMD;
2190 }
2191 $obj->pat($inpat);
2192 } ## end if ($inpat ne "")
2193
2194 # Where we are now is where to stop after wraparound.
2195 $end = $start;
2196
2197 # Don't move away from this line.
2198 $incr = -1;
2199
2200 my $pat = $obj->pat;
2201 # Search inside the eval to prevent pattern badness
2202 # from killing us.
2203 eval {
2204 no strict q/vars/;
2205 for (;;) {
2206 # Back up a line.
2207 --$start;
2208
2209 # Wrap if we pass the first line.
2210
2211 $start = $max if ($start <= 0);
2212
2213 # Quit if we get back where we started,
2214 last if ($start == $end);
2215
2216 # Match?
2217 if ($dbline[$start] =~ m/$pat/i) {
2218 if ($slave_editor) {
2219 # Yep, follow slave editor requirements.
2220 print $OUT "\032\032$filename:$start:0\n";
2221 }
2222 else {
2223 # Yep, just print normally.
2224 print $OUT "$start:\t",$dbline[$start],"\n";
2225 }
2226
2227 # Found, so done.
2228 last;
2229 }
2230 }
2231 };
2232
2233 # Say we failed if the loop never found anything,
2234 if ( $start == $end ) {
2235 print {$OUT} "?$pat?: not found\n";
2236 }
2237 next CMD;
2238 }
2239
2240 return;
2241}
2242
5f166812
SF
2243sub _DB__handle_restart_and_rerun_commands {
2244 my ($obj) = @_;
2245
2246 # R - restart execution.
2247 # rerun - controlled restart execution.
2248 if (my ($cmd_cmd, $cmd_params) =
2249 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
2250 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2251
2252 # Close all non-system fds for a clean restart. A more
2253 # correct method would be to close all fds that were not
2254 # open when the process started, but this seems to be
2255 # hard. See "debugger 'R'estart and open database
2256 # connections" on p5p.
2257
2258 my $max_fd = 1024; # default if POSIX can't be loaded
2259 if (eval { require POSIX }) {
2260 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2261 }
2262
2263 if (defined $max_fd) {
2264 foreach ($^F+1 .. $max_fd-1) {
2265 next unless open FD_TO_CLOSE, "<&=$_";
2266 close(FD_TO_CLOSE);
2267 }
2268 }
2269
2270 # And run Perl again. We use exec() to keep the
2271 # PID stable (and that way $ini_pids is still valid).
2272 exec(@args) or print {$OUT} "exec failed: $!\n";
2273
2274 last CMD;
2275 }
2276
2277 return;
2278}
2279
33f361f5
SF
2280sub _DB__handle_run_command_in_pager_command {
2281 my ($obj) = @_;
2282
2283 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2284 if ( $pager =~ /^\|/ ) {
2285
2286 # Default pager is into a pipe. Redirect I/O.
2287 open( SAVEOUT, ">&STDOUT" )
2288 || DB::warn("Can't save STDOUT");
2289 open( STDOUT, ">&OUT" )
2290 || DB::warn("Can't redirect STDOUT");
2291 } ## end if ($pager =~ /^\|/)
2292 else {
2293
2294 # Not into a pipe. STDOUT is safe.
2295 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
2296 }
2297
2298 # Fix up environment to record we have less if so.
2299 fix_less();
2300
2301 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2302
2303 # Couldn't open pipe to pager.
2304 DB::warn("Can't pipe output to '$pager'");
2305 if ( $pager =~ /^\|/ ) {
2306
2307 # Redirect I/O back again.
2308 open( OUT, ">&STDOUT" ) # XXX: lost message
2309 || DB::warn("Can't restore DB::OUT");
2310 open( STDOUT, ">&SAVEOUT" )
2311 || DB::warn("Can't restore STDOUT");
2312 close(SAVEOUT);
2313 } ## end if ($pager =~ /^\|/)
2314 else {
2315
2316 # Redirect I/O. STDOUT already safe.
2317 open( OUT, ">&STDOUT" ) # XXX: lost message
2318 || DB::warn("Can't restore DB::OUT");
2319 }
2320 next CMD;
2321 } ## end unless ($piped = open(OUT,...
2322
2323 # Set up broken-pipe handler if necessary.
2324 $SIG{PIPE} = \&DB::catch
2325 if $pager =~ /^\|/
2326 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2327
2328 OUT->autoflush(1);
2329 # Save current filehandle, and put it back.
2330 $obj->selected(scalar( select(OUT) ));
2331 # Don't put it back if pager was a pipe.
2332 if ($cmd !~ /\A\|\|/)
2333 {
2334 select($obj->selected());
2335 $obj->selected("");
2336 }
2337
2338 # Trim off the pipe symbols and run the command now.
2339 $cmd =~ s#\A\|+\s*##;
2340 redo PIPE;
2341 }
2342
2343 return;
2344}
2345
321095c5
SF
2346sub _DB__handle_m_command {
2347 my ($obj) = @_;
2348
2349 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2350 methods($1);
2351 next CMD;
2352 }
2353
2354 # m expr - set up DB::eval to do the work
2355 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2356 $onetimeDump = 'methods'; # method output gets used there
2357 }
2358
2359 return;
2360}
33f361f5 2361
8e4cceb9
SF
2362sub _DB__at_end_of_every_command {
2363 my ($obj) = @_;
2364
2365 # At the end of every command:
2366 if ($obj->piped) {
2367
2368 # Unhook the pipe mechanism now.
2369 if ( $pager =~ /^\|/ ) {
2370
2371 # No error from the child.
2372 $? = 0;
2373
2374 # we cannot warn here: the handle is missing --tchrist
2375 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2376
2377 # most of the $? crud was coping with broken cshisms
2378 # $? is explicitly set to 0, so this never runs.
2379 if ($?) {
2380 print SAVEOUT "Pager '$pager' failed: ";
2381 if ( $? == -1 ) {
2382 print SAVEOUT "shell returned -1\n";
2383 }
2384 elsif ( $? >> 8 ) {
2385 print SAVEOUT ( $? & 127 )
2386 ? " (SIG#" . ( $? & 127 ) . ")"
2387 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2388 }
2389 else {
2390 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2391 }
2392 } ## end if ($?)
2393
2394 # Reopen filehandle for our output (if we can) and
2395 # restore STDOUT (if we can).
2396 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
2397 open( STDOUT, ">&SAVEOUT" )
2398 || &warn("Can't restore STDOUT");
2399
2400 # Turn off pipe exception handler if necessary.
2401 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2402
2403 # Will stop ignoring SIGPIPE if done like nohup(1)
2404 # does SIGINT but Perl doesn't give us a choice.
2405 } ## end if ($pager =~ /^\|/)
2406 else {
2407
2408 # Non-piped "pager". Just restore STDOUT.
2409 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
2410 }
2411
2412 # Close filehandle pager was using, restore the normal one
2413 # if necessary,
2414 close(SAVEOUT);
2415
2416 if ($obj->selected() ne "") {
2417 select($obj->selected);
2418 $obj->selected("");
2419 }
2420
2421 # No pipes now.
2422 $obj->piped("");
2423 } ## end if ($piped)
2424
2425 return;
2426}
2427
47e3b8cc
SF
2428# 't' is type.
2429# 'm' is method.
2430# 'v' is the value (i.e: method name or subroutine ref).
2431# 's' is subroutine.
2432my %cmd_lookup =
2433(
c9a9a6c0 2434 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2435 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2436 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2437 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2438 'S' => { t => 'm', v => '_handle_S_command', },
2439 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2440 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2441 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2442 'f' => { t => 's', v => \&_DB__handle_f_command, },
2443 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2444 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2445 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2446 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2447 'r' => { t => 'm', v => '_handle_r_command', },
2448 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2449 'save' => { t => 'm', v => '_handle_save_command', },
2450 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2451 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2452 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2453 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2454 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2455 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2456 ('X', 'V')),
8f144dfc
SF
2457 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2458 qw(enable disable)),
2459 (map { $_ =>
2460 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2461 } qw(R rerun)),
fbe9ebae
SF
2462 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2463 qw(a A b B e E h i l L M o O P v w W)),
47e3b8cc
SF
2464);
2465
2b0b9dd1
SF
2466sub DB {
2467
2468 # lock the debugger and get the thread id for the prompt
2469 lock($DBGR);
2470 my $tid;
2471 my $position;
2472 my ($prefix, $after, $infix);
2473 my $pat;
22fc883d 2474 my $explicit_stop;
33f361f5
SF
2475 my $piped;
2476 my $selected;
2b0b9dd1
SF
2477
2478 if ($ENV{PERL5DB_THREADED}) {
2479 $tid = eval { "[".threads->tid."]" };
2480 }
2481
610f01b9 2482 my $cmd_verb;
35cd713a 2483
22fc883d
SF
2484 my $obj = DB::Obj->new(
2485 {
2486 position => \$position,
2487 prefix => \$prefix,
2488 after => \$after,
2489 explicit_stop => \$explicit_stop,
2490 infix => \$infix,
610f01b9 2491 cmd_verb => \$cmd_verb,
a4d311a3 2492 pat => \$pat,
33f361f5
SF
2493 piped => \$piped,
2494 selected => \$selected,
22fc883d
SF
2495 },
2496 );
2497
2498 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2499
69893cff
RGS
2500 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2501 # The code being debugged may have altered them.
d338d6fe 2502 &save;
69893cff
RGS
2503
2504 # Since DB::DB gets called after every line, we can use caller() to
2505 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2506 # caller is returning all the extra information when called from the
69893cff 2507 # debugger.
e22ea7cc 2508 local ( $package, $filename, $line ) = caller;
6b24a4b7 2509 $filename_ini = $filename;
69893cff
RGS
2510
2511 # set up the context for DB::eval, so it can properly execute
2512 # code on behalf of the user. We add the package in so that the
2513 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2514 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2515
2516 # Create an alias to the active file magical array to simplify
2517 # the code here.
e22ea7cc 2518 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2519
69893cff 2520 # Last line in the program.
55783941 2521 $max = $#dbline;
69893cff 2522
22fc883d 2523 _DB__determine_if_we_should_break(@_);
69893cff
RGS
2524
2525 # Preserve the current stop-or-not, and see if any of the W
2526 # (watch expressions) has changed.
36477c24 2527 my $was_signal = $signal;
69893cff
RGS
2528
2529 # If we have any watch expressions ...
22fc883d 2530 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
2531
2532=head2 C<watchfunction()>
2533
2534C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2535function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2536current package, filename, and line as its parameters.
2537
b570d64b 2538The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2539debugger's context, so it has access to all of the debugger's internal
2540data structures and functions.
2541
2542C<watchfunction()> can control the debugger's actions. Any of the following
2543will cause the debugger to return control to the user's program after
2544C<watchfunction()> executes:
2545
b570d64b 2546=over 4
69893cff 2547
be9a9b1d
AT
2548=item *
2549
2550Returning a false value from the C<watchfunction()> itself.
2551
2552=item *
2553
2554Altering C<$single> to a false value.
2555
2556=item *
69893cff 2557
be9a9b1d 2558Altering C<$signal> to a false value.
69893cff 2559
be9a9b1d 2560=item *
69893cff 2561
be9a9b1d 2562Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2563check for C<watchfunction()>. This can be done with
2564
2565 $trace &= ~4;
2566
2567=back
2568
2569=cut
2570
e22ea7cc 2571 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2572 # current package, filename, and line. The function executes in
2573 # the DB:: package.
e22ea7cc
RF
2574 if ( $trace & 4 ) { # User-installed watch
2575 return
2576 if watchfunction( $package, $filename, $line )
2577 and not $single
2578 and not $was_signal
2579 and not( $trace & ~4 );
69893cff
RGS
2580 } ## end if ($trace & 4)
2581
e22ea7cc 2582 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2583 # turn off the signal now.
6027b9a3 2584 $was_signal = $signal;
69893cff
RGS
2585 $signal = 0;
2586
2587=head2 GETTING READY TO EXECUTE COMMANDS
2588
2589The debugger decides to take control if single-step mode is on, the
2590C<t> command was entered, or the user generated a signal. If the program
2591has fallen off the end, we set things up so that entering further commands
2592won't cause trouble, and we say that the program is over.
2593
2594=cut
2595
8dc67a69
SF
2596 # Make sure that we always print if asked for explicitly regardless
2597 # of $trace_to_depth .
22fc883d 2598 $explicit_stop = ($single || $was_signal);
8dc67a69 2599
69893cff
RGS
2600 # Check to see if we should grab control ($single true,
2601 # trace set appropriately, or we got a signal).
8dc67a69 2602 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2603 $obj->_DB__grab_control(@_);
69893cff
RGS
2604 } ## end if ($single || ($trace...
2605
2606=pod
2607
2608If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2609If there are any preprompt actions, execute those as well.
e219e2fb
RF
2610
2611=cut
2612
69893cff 2613 # If there's an action, do it now.
05da04df
SF
2614 if ($action) {
2615 $evalarg = $action;
2616 DB::eval();
2617 }
e219e2fb 2618
69893cff
RGS
2619 # Are we nested another level (e.g., did we evaluate a function
2620 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2621 if ( $single || $was_signal ) {
2622
69893cff 2623 # Yes, go down a level.
e22ea7cc 2624 local $level = $level + 1;
69893cff
RGS
2625
2626 # Do any pre-prompt actions.
e22ea7cc 2627 foreach $evalarg (@$pre) {
7c54f46a 2628 DB::eval();
e22ea7cc 2629 }
69893cff
RGS
2630
2631 # Complain about too much recursion if we passed the limit.
05da04df
SF
2632 if ($single & 4) {
2633 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2634 }
69893cff
RGS
2635
2636 # The line we're currently on. Set $incr to -1 to stay here
2637 # until we get a command that tells us to advance.
e22ea7cc
RF
2638 $start = $line;
2639 $incr = -1; # for backward motion.
69893cff
RGS
2640
2641 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2642 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2643
2644=head2 WHERE ARE WE?
2645
2646XXX Relocate this section?
2647
2648The debugger normally shows the line corresponding to the current line of
2649execution. Sometimes, though, we want to see the next line, or to move elsewhere
2650in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2651
be9a9b1d
AT
2652C<$incr> controls by how many lines the I<current> line should move forward
2653after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2654line shouldn't change.
2655
be9a9b1d 2656C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2657move forwards or backwards from when doing an C<L> or C<-> command.
2658
2659C<$max> tells the debugger where the last line of the current file is. It's
2660used to terminate loops most often.
2661
2662=head2 THE COMMAND LOOP
2663
2664Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2665in two parts:
2666
2667=over 4
2668
be9a9b1d
AT
2669=item *
2670
2671The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2672reads a command and then executes it.
2673
be9a9b1d
AT
2674=item *
2675
2676The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2677is wholly contained inside the C<CMD> block and only executes a command.
2678Used to handle commands running inside a pager.
2679
2680=back
2681
2682So why have two labels to restart the loop? Because sometimes, it's easier to
2683have a command I<generate> another command and then re-execute the loop to do
2684the new command. This is faster, but perhaps a bit more convoluted.
2685
2686=cut
2687
2688 # The big command dispatch loop. It keeps running until the
2689 # user yields up control again.
2690 #
2691 # If we have a terminal for input, and we get something back
2692 # from readline(), keep on processing.
6b24a4b7 2693
e22ea7cc 2694 CMD:
32bbadc6 2695 while (_DB__read_next_cmd($tid))
69893cff 2696 {
e22ea7cc 2697
8380a245 2698 share($cmd);
69893cff
RGS
2699 # ... try to execute the input as debugger commands.
2700
2701 # Don't stop running.
2702 $single = 0;
2703
2704 # No signal is active.
2705 $signal = 0;
2706
2707 # Handle continued commands (ending with \):
3d7a2a93 2708 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2709 $cmd .= DB::readline(" cont: ");
e22ea7cc 2710 redo CMD;
3d7a2a93 2711 }
69893cff
RGS
2712
2713=head4 The null command
2714
be9a9b1d 2715A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2716command out of C<$laststep> (where it was recorded previously), and copy it
2717back into C<$cmd> to be executed below. If there wasn't any previous command,
2718we'll do nothing below (no command will match). If there was, we also save it
2719in the command history and fall through to allow the command parsing to pick
2720it up.
2721
2722=cut
2723
2724 # Empty input means repeat the last command.
eeb7da96
SF
2725 if ($cmd eq '') {
2726 $cmd = $laststep;
2727 }
e22ea7cc 2728 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2729 if (length($cmd) >= 2) {
2730 push( @hist, $cmd );
2731 }
e22ea7cc 2732 push( @truehist, $cmd );
2dbd01ad
SF
2733 share(@hist);
2734 share(@truehist);
e22ea7cc
RF
2735
2736 # This is a restart point for commands that didn't arrive
2737 # via direct user input. It allows us to 'redo PIPE' to
2738 # re-execute command processing without reading a new command.
69893cff 2739 PIPE: {
af84fb69 2740 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2741
2742=head3 COMMAND ALIASES
2743
2744The debugger can create aliases for commands (these are stored in the
2745C<%alias> hash). Before a command is executed, the command loop looks it up
2746in the alias hash and substitutes the contents of the alias for the command,
2747completely replacing it.
2748
2749=cut
2750
2751 # See if there's an alias for the command, and set it up if so.
610f01b9 2752 if ( $alias{$cmd_verb} ) {
e22ea7cc 2753
69893cff
RGS
2754 # Squelch signal handling; we want to keep control here
2755 # if something goes loco during the alias eval.
2756 local $SIG{__DIE__};
2757 local $SIG{__WARN__};
2758
2759 # This is a command, so we eval it in the DEBUGGER's
2760 # scope! Otherwise, we can't see the special debugger
2761 # variables, or get to the debugger's subs. (Well, we
2762 # _could_, but why make it even more complicated?)
610f01b9 2763 eval "\$cmd =~ $alias{$cmd_verb}";
69893cff
RGS
2764 if ($@) {
2765 local $\ = '';
610f01b9 2766 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@";
69893cff
RGS
2767 next CMD;
2768 }
af84fb69 2769 _DB__trim_command_and_return_first_component($obj);
610f01b9 2770 } ## end if ($alias{$cmd_verb})
69893cff
RGS
2771
2772=head3 MAIN-LINE COMMANDS
2773
2774All of these commands work up to and after the program being debugged has
b570d64b 2775terminated.
69893cff
RGS
2776
2777=head4 C<q> - quit
2778
b570d64b 2779Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2780try to execute further, cleaning any restart-related stuff out of the
2781environment, and executing with the last value of C<$?>.
2782
2783=cut
2784
fbe9ebae
SF
2785 # All of these commands were remapped in perl 5.8.0;
2786 # we send them off to the secondary dispatcher (see below).
2787 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2788 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2789
610f01b9 2790 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) {
47e3b8cc
SF
2791 my $type = $cmd_rec->{t};
2792 my $val = $cmd_rec->{v};
2793 if ($type eq 'm') {
2794 $obj->$val();
2795 }
2796 elsif ($type eq 's') {
2797 $val->($obj);
2798 }
2799 }
69893cff 2800
611272bb 2801=head4 C<t> - trace [n]
69893cff
RGS
2802
2803Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2804If level is specified, set C<$trace_to_depth>.
69893cff 2805
69893cff
RGS
2806=head4 C<S> - list subroutines matching/not matching a pattern
2807
2808Walks through C<%sub>, checking to see whether or not to print the name.
2809
69893cff
RGS
2810=head4 C<X> - list variables in current package
2811
b570d64b 2812Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2813appropriate C<V> command and fall through.
2814
69893cff
RGS
2815=head4 C<V> - list variables
2816
b570d64b 2817Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2818
69893cff
RGS
2819=head4 C<x> - evaluate and print an expression
2820
2821Hands the expression off to C<DB::eval>, setting it up to print the value
2822via C<dumpvar.pl> instead of just printing it directly.
2823
69893cff
RGS
2824=head4 C<m> - print methods
2825
2826Just uses C<DB::methods> to determine what methods are available.
2827
69893cff
RGS
2828=head4 C<f> - switch files
2829
73decac7 2830Switch to a different filename.
69893cff 2831
69893cff
RGS
2832=head4 C<.> - return to last-executed line.
2833
2834We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2835and then we look up the line in the magical C<%dbline> hash.
2836
69893cff
RGS
2837=head4 C<-> - back one window
2838
2839We change C<$start> to be one window back; if we go back past the first line,
2840we set it to be the first line. We ser C<$incr> to put us back at the
2841currently-executing line, and then put a C<l $start +> (list one window from
2842C<$start>) in C<$cmd> to be executed later.
2843
8481f647 2844=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2845
2846In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2847problems, most notably that the default case of several commands destroying
2848the user's work in setting watchpoints, actions, etc. We wanted, however, to
2849retain the old commands for those who were used to using them or who preferred
2850them. At this point, we check for the new commands and call C<cmd_wrapper> to
2851deal with them instead of processing them in-line.
2852
69893cff
RGS
2853=head4 C<y> - List lexicals in higher scope
2854
826b9a2e 2855Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2856above the current one and then displays then using C<dumpvar.pl>.
2857
69893cff
RGS
2858=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2859
2860All of the commands below this point don't work after the program being
2861debugged has ended. All of them check to see if the program has ended; this
2862allows the commands to be relocated without worrying about a 'line of
2863demarcation' above which commands can be entered anytime, and below which
2864they can't.
2865
2866=head4 C<n> - single step, but don't trace down into subs
2867
2868Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2869when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2870so a null command knows what to re-execute.
69893cff 2871
69893cff
RGS
2872=head4 C<s> - single-step, entering subs
2873
826b9a2e 2874Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2875subs. Also saves C<s> as C<$lastcmd>.
2876
69893cff
RGS
2877=head4 C<c> - run continuously, setting an optional breakpoint
2878
2879Most of the code for this command is taken up with locating the optional
2880breakpoint, which is either a subroutine name or a line number. We set
2881the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2882in this and all call levels above this one.
2883
69893cff
RGS
2884=head4 C<r> - return from a subroutine
2885
2886For C<r> to work properly, the debugger has to stop execution again
2887immediately after the return is executed. This is done by forcing
2888single-stepping to be on in the call level above the current one. If
2889we are printing return values when a C<r> is executed, set C<$doret>
2890appropriately, and force us out of the command loop.
2891
69893cff
RGS
2892=head4 C<T> - stack trace
2893
2894Just calls C<DB::print_trace>.
2895
69893cff
RGS
2896=head4 C<w> - List window around current line.
2897
2898Just calls C<DB::cmd_w>.
2899
69893cff
RGS
2900=head4 C<W> - watch-expression processing.
2901
b570d64b 2902Just calls C<DB::cmd_W>.
69893cff 2903
69893cff
RGS
2904=head4 C</> - search forward for a string in the source
2905
ef18ae63 2906We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2907bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2908If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2909mess us up.
2910
2911=cut
2912
a4d311a3 2913 _DB__handle_forward_slash_command($obj);
69893cff
RGS
2914
2915=head4 C<?> - search backward for a string in the source
2916
2917Same as for C</>, except the loop runs backwards.
2918
2919=cut
2920
11f0f050 2921 _DB__handle_question_mark_command($obj);
69893cff
RGS
2922
2923=head4 C<$rc> - Recall command
2924
2925Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2926that the terminal supports history). It find the the command required, puts it
2927into C<$cmd>, and redoes the loop to execute it.
2928
2929=cut
2930
e22ea7cc 2931 # $rc - recall command.
14f38b27 2932 $obj->_handle_rc_recall_command;
69893cff
RGS
2933
2934=head4 C<$sh$sh> - C<system()> command
2935
2936Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2937C<STDOUT> from getting messed up.
2938
2939=cut
2940
466f24c7 2941 $obj->_handle_sh_command;
69893cff
RGS
2942
2943=head4 C<$rc I<pattern> $rc> - Search command history
2944
2945Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2946If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2947
2948=cut
2949
0d2c714c 2950 $obj->_handle_rc_search_history_command;
69893cff 2951
ef18ae63 2952=head4 C<$sh> - Invoke a shell
69893cff
RGS
2953
2954Uses C<DB::system> to invoke a shell.
2955
2956=cut
2957
69893cff
RGS
2958=head4 C<$sh I<command>> - Force execution of a command in a shell
2959
2960Like the above, but the command is passed to the shell. Again, we use
2961C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2962
69893cff
RGS
2963=head4 C<H> - display commands in history
2964
2965Prints the contents of C<@hist> (if any).
2966
69893cff
RGS
2967=head4 C<man, doc, perldoc> - look up documentation
2968
2969Just calls C<runman()> to print the appropriate document.
2970
2971=cut
2972
c7b0c61d 2973 $obj->_handle_doc_command;
69893cff
RGS
2974
2975=head4 C<p> - print
2976
2977Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2978the bottom of the loop.
2979
69893cff
RGS
2980=head4 C<=> - define command alias
2981
2982Manipulates C<%alias> to add or list command aliases.
2983
69893cff
RGS
2984=head4 C<source> - read commands from a file.
2985
2986Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
2987pick it up.
2988
d0ecd4f3 2989=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 2990
d0ecd4f3 2991This enables or disables breakpoints.
e09195af 2992
69893cff
RGS
2993=head4 C<save> - send current history to a file
2994
2995Takes the complete history, (not the shrunken version you see with C<H>),
2996and saves it to the given filename, so it can be replayed using C<source>.
2997
2998Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
2999
7fddc82f
RF
3000=head4 C<R> - restart
3001
ef18ae63 3002Restart the debugger session.
7fddc82f
RF
3003
3004=head4 C<rerun> - rerun the current session
3005
3006Return to any given position in the B<true>-history list
3007
69893cff
RGS
3008=head4 C<|, ||> - pipe output through the pager.
3009
be9a9b1d 3010For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3011(the program's standard output). For C<||>, we only save C<OUT>. We open a
3012pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3013is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3014set C<$signal>, sending us back into the debugger.
3015
3016We then trim off the pipe symbols and C<redo> the command loop at the
3017C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3018reading another.
3019
3020=cut
3021
3022 # || - run command in the pager, with output to DB::OUT.
33f361f5 3023 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3024
3025=head3 END OF COMMAND PARSING
3026
ff41e38d
SF
3027Anything left in C<$cmd> at this point is a Perl expression that we want to
3028evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3029any variables we might want to address in the C<DB> package.
3030
3031=cut
3032
e22ea7cc 3033 } # PIPE:
69893cff 3034
e22ea7cc 3035 # Make sure the flag that says "the debugger's running" is
69893cff 3036 # still on, to make sure we get control again.
e22ea7cc 3037 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3038
3039 # Run *our* eval that executes in the caller's context.
7c54f46a 3040 DB::eval();
69893cff
RGS
3041
3042 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3043 if ($onetimeDump) {
3044 $onetimeDump = undef;
69893cff 3045 $onetimedumpDepth = undef;
e22ea7cc
RF
3046 }
3047 elsif ( $term_pid == $$ ) {
8380a245 3048 eval { # May run under miniperl, when not available...
c7e68384
IZ
3049 STDOUT->flush();
3050 STDERR->flush();
8380a245 3051 };
e22ea7cc 3052
69893cff 3053 # XXX If this is the master pid, print a newline.
8380a245 3054 print {$OUT} "\n";
e22ea7cc
RF
3055 }
3056 } ## end while (($term || &setterm...
69893cff
RGS
3057
3058=head3 POST-COMMAND PROCESSING
3059
3060After each command, we check to see if the command output was piped anywhere.
3061If so, we go through the necessary code to unhook the pipe and go back to
3062our standard filehandles for input and output.
3063
3064=cut
3065
e22ea7cc 3066 continue { # CMD:
8e4cceb9 3067 _DB__at_end_of_every_command($obj);
e22ea7cc 3068 } # CMD:
69893cff
RGS
3069
3070=head3 COMMAND LOOP TERMINATION
3071
3072When commands have finished executing, we come here. If the user closed the
3073input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3074evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3075C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3076The interpreter will then execute the next line and then return control to us
3077again.
3078
3079=cut
3080
3081 # No more commands? Quit.
1f874cb6 3082 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3083
3084 # Evaluate post-prompt commands.
e22ea7cc 3085 foreach $evalarg (@$post) {
7c54f46a 3086 DB::eval();
e22ea7cc
RF
3087 }
3088 } # if ($single || $signal)
69893cff
RGS
3089
3090 # Put the user's globals back where you found them.
e22ea7cc 3091 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3092 ();
3093} ## end sub DB
3094
22fc883d
SF
3095package DB::Obj;
3096
3097sub new {
3098 my $class = shift;
3099
3100 my $self = bless {}, $class;
3101
3102 $self->_init(@_);
3103
3104 return $self;
3105}
3106
3107sub _init {
3108 my ($self, $args) = @_;
3109
3110 %{$self} = (%$self, %$args);
3111
3112 return;
3113}
3114
3115{
3116 no strict 'refs';
a4d311a3 3117 foreach my $slot_name (qw(
610f01b9 3118 after explicit_stop infix pat piped position prefix selected cmd_verb
a4d311a3 3119 )) {
22fc883d
SF
3120 my $slot = $slot_name;
3121 *{$slot} = sub {
3122 my $self = shift;
3123
3124 if (@_) {
3125 ${ $self->{$slot} } = shift;
3126 }
3127
3128 return ${ $self->{$slot} };
3129 };
8def6eff
SF
3130
3131 *{"append_to_$slot"} = sub {
3132 my $self = shift;
3133 my $s = shift;
3134
3135 return $self->$slot($self->$slot . $s);
3136 };
22fc883d
SF
3137 }
3138}
3139
3140sub _DB_on_init__initialize_globals
3141{
3142 my $self = shift;
3143
3144 # Check for whether we should be running continuously or not.
3145 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3146 if ( $single and not $second_time++ ) {
22fc883d
SF
3147
3148 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3149 if ($runnonstop) { # Disable until signal
22fc883d
SF
3150 # If there's any call stack in place, turn off single
3151 # stepping into subs throughout the stack.
8ad70697
SF
3152 for my $i (0 .. $stack_depth) {
3153 $stack[ $i ] &= ~1;
22fc883d
SF
3154 }
3155
3156 # And we are now no longer in single-step mode.
ebd0282e 3157 $single = 0;
22fc883d
SF
3158
3159 # If we simply returned at this point, we wouldn't get
3160 # the trace info. Fall on through.
3161 # return;
3162 } ## end if ($runnonstop)
3163
8ad70697 3164 elsif ($ImmediateStop) {
22fc883d
SF
3165
3166 # We are supposed to stop here; XXX probably a break.
8ad70697 3167 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3168 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3169 # us into the command loop
3170 }
3171 } ## end if ($single and not $second_time...
3172
3173 # If we're in single-step mode, or an interrupt (real or fake)
3174 # has occurred, turn off non-stop mode.
ebd0282e 3175 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3176
3177 return;
3178}
3179
3180sub _DB__handle_watch_expressions
3181{
3182 my $self = shift;
3183
931ac036 3184 if ( $trace & 2 ) {
8ad70697
SF
3185 for my $n (0 .. $#to_watch) {
3186 $evalarg = $to_watch[$n];
3187 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3188
3189 # Fix context DB::eval() wants to return an array, but
3190 # we need a scalar here.
7c54f46a 3191 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3192 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3193
3194 # Did it change?
8ad70697 3195 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3196
3197 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3198 $signal = 1;
8ad70697
SF
3199 print {$OUT} <<EOP;
3200Watchpoint $n:\t$to_watch[$n] changed:
3201 old value:\t$old_watch[$n]
22fc883d
SF
3202 new value:\t$val
3203EOP
8ad70697 3204 $old_watch[$n] = $val;
22fc883d
SF
3205 } ## end if ($val ne $old_watch...
3206 } ## end for my $n (0 ..
3207 } ## end if ($trace & 2)
3208
3209 return;
3210}
3211
ad46ac70
SF
3212sub _my_print_lineinfo
3213{
3214 my ($self, $i, $incr_pos) = @_;
3215
18b5b545 3216 if ($frame) {
ad46ac70 3217 # Print it indented if tracing is on.
8ad70697 3218 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3219 "$i:\t$DB::dbline[$i]" . $self->after );
3220 }
3221 else {
3222 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3223 }
3224}
3225
44a07e3e 3226sub _curr_line {
18b5b545 3227 return $DB::dbline[$line];
44a07e3e
SF
3228}
3229
22fc883d
SF
3230sub _DB__grab_control
3231{
3232 my $self = shift;
3233
3234 # Yes, grab control.
7793e5c2 3235 if ($slave_editor) {
22fc883d
SF
3236
3237 # Tell the editor to update its position.
18b5b545 3238 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3239 DB::print_lineinfo($self->position());
3240 }
3241
3242=pod
3243
3244Special check: if we're in package C<DB::fake>, we've gone through the
3245C<END> block at least once. We set up everything so that we can continue
3246to enter commands and have a valid context to be in.
3247
3248=cut
3249
3250 elsif ( $DB::package eq 'DB::fake' ) {
3251
3252 # Fallen off the end already.
3253 if (!$DB::term) {
3254 DB::setterm();
3255 }
3256
3257 DB::print_help(<<EOP);
3258Debugged program terminated. Use B<q> to quit or B<R> to restart,
3259use B<o> I<inhibit_exit> to avoid stopping after program termination,
3260B<h q>, B<h R> or B<h o> to get additional info.
3261EOP
3262
3263 # Set the DB::eval context appropriately.
3264 $DB::package = 'main';
3265 $DB::usercontext = DB::_calc_usercontext($DB::package);
3266 } ## end elsif ($package eq 'DB::fake')
3267
3268=pod
3269
3270If the program hasn't finished executing, we scan forward to the
3271next executable line, print that out, build the prompt from the file and line
3272number information, and print that.
3273
3274=cut
3275
3276 else {
3277
3278
3279 # Still somewhere in the midst of execution. Set up the
3280 # debugger prompt.
3281 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3282 # Perl 5 ones (sorry, we don't print Klingon
3283 #module names)
3284
3285 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3286 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3287 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3288
3289 # Break up the prompt if it's really long.
3290 if ( length($self->prefix()) > 30 ) {
18b5b545 3291 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3292 $self->prefix("");
3293 $self->infix(":\t");
3294 }
3295 else {
3296 $self->infix("):\t");
3297 $self->position(
18b5b545 3298 $self->prefix . $line. $self->infix
44a07e3e 3299 . $self->_curr_line . $self->after
22fc883d
SF
3300 );
3301 }
3302
3303 # Print current line info, indenting if necessary.
18b5b545 3304 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3305
44a07e3e
SF
3306 my $i;
3307 my $line_i = sub { return $DB::dbline[$i]; };
3308
22fc883d
SF
3309 # Scan forward, stopping at either the end or the next
3310 # unbreakable line.
18b5b545 3311 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3312 { #{ vi
3313
3314 # Drop out on null statements, block closers, and comments.
44a07e3e 3315 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3316
3317 # Drop out if the user interrupted us.
ebd0282e 3318 last if $signal;
22fc883d
SF
3319
3320 # Append a newline if the line doesn't have one. Can happen
3321 # in eval'ed text, for instance.
44a07e3e 3322 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3323
3324 # Next executable line.
44a07e3e 3325 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3326 . $self->after;
8def6eff 3327 $self->append_to_position($incr_pos);
ad46ac70 3328 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3329 } ## end for ($i = $line + 1 ; $i...
3330 } ## end else [ if ($slave_editor)
3331
3332 return;
3333}
3334
174f9c5e
SF
3335sub _handle_t_command {
3336 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
931ac036 3337 $trace ^= 1;
174f9c5e 3338 local $\ = '';
8ad70697
SF
3339 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3340 print {$OUT} "Trace = "
931ac036 3341 . ( ( $trace & 1 )
174f9c5e
SF
3342 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3343 : "off" ) . "\n";
3344 next CMD;
3345 }
3346
3347 return;
3348}
3349
9d0b71b3
SF
3350
3351sub _handle_S_command {
3352 if (my ($print_all_subs, $should_reverse, $Spatt)
3353 = $DB::cmd =~ /\AS(\s+(!)?(.+))?\z/) {
3354 # $Spatt is the pattern (if any) to use.
3355 # Reverse scan?
3356 my $Srev = defined $should_reverse;
3357 # No args - print all subs.
3358 my $Snocheck = !defined $print_all_subs;
3359
3360 # Need to make these sane here.
3361 local $\ = '';
3362 local $, = '';
3363
3364 # Search through the debugger's magical hash of subs.
3365 # If $nocheck is true, just print the sub name.
3366 # Otherwise, check it against the pattern. We then use
3367 # the XOR trick to reverse the condition as required.
3368 foreach $subname ( sort( keys %sub ) ) {
3369 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3370 print $OUT $subname, "\n";
3371 }
3372 }
3373 next CMD;
3374 }
3375
3376 return;
3377}
3378
1ce985d2
SF
3379sub _handle_V_command_and_X_command {
3380
3381 $DB::cmd =~ s/^X\b/V $DB::package/;
3382
3383 # Bare V commands get the currently-being-debugged package
3384 # added.
3385 if ($DB::cmd eq "V") {
3386 $DB::cmd = "V $DB::package";
3387 }
3388
3389 # V - show variables in package.
3390 if (my ($new_packname, $new_vars_str) =
3391 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3392
3393 # Save the currently selected filehandle and
3394 # force output to debugger's filehandle (dumpvar
3395 # just does "print" for output).
3396 my $savout = select($OUT);
3397
3398 # Grab package name and variables to dump.
3399 $packname = $new_packname;
3400 my @vars = split( ' ', $new_vars_str );
3401
3402 # If main::dumpvar isn't here, get it.
3403 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3404 if ( defined &main::dumpvar ) {
3405
3406 # We got it. Turn off subroutine entry/exit messages
3407 # for the moment, along with return values.
3408 local $frame = 0;
3409 local $doret = -2;
3410
3411 # must detect sigpipe failures - not catching
3412 # then will cause the debugger to die.
3413 eval {
3414 &main::dumpvar(
3415 $packname,
3416 defined $option{dumpDepth}
3417 ? $option{dumpDepth}
3418 : -1, # assume -1 unless specified
3419 @vars
3420 );
3421 };
3422
3423 # The die doesn't need to include the $@, because
3424 # it will automatically get propagated for us.
3425 if ($@) {
3426 die unless $@ =~ /dumpvar print failed/;
3427 }
3428 } ## end if (defined &main::dumpvar)
3429 else {
3430
3431 # Couldn't load dumpvar.
3432 print $OUT "dumpvar.pl not available.\n";
3433 }
3434
3435 # Restore the output filehandle, and go round again.
3436 select($savout);
3437 next CMD;
3438 }
3439
3440 return;
3441}
3442
d1450c23
SF
3443sub _handle_dash_command {
3444
3445 if ($DB::cmd eq '-') {
3446
3447 # back up by a window; go to 1 if back too far.
3448 $start -= $incr + $window + 1;
3449 $start = 1 if $start <= 0;
3450 $incr = $window - 1;
3451
3452 # Generate and execute a "l +" command (handled below).
3453 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3454 redo CMD;
d1450c23
SF
3455 }
3456 return;
3457}
3458
cb9d1513
SF
3459sub _n_or_s_commands_generic {
3460 my ($self, $new_val) = @_;
73c5e526 3461 # n - next
cb9d1513 3462 next CMD if DB::_DB__is_finished();
73c5e526 3463
cb9d1513
SF
3464 # Single step, but don't enter subs.
3465 $single = $new_val;
3466
3467 # Save for empty command (repeat last).
3468 $laststep = $DB::cmd;
3469 last CMD;
3470}
73c5e526 3471
cb9d1513
SF
3472sub _n_or_s {
3473 my ($self, $letter, $new_val) = @_;
3474
3475 if ($DB::cmd eq $letter) {
3476 $self->_n_or_s_commands_generic($new_val);
73c5e526 3477 }
50a8a759
SF
3478 elsif ($DB::cmd =~ m#\A\Q$letter\E\b#) {
3479 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3480 }
73c5e526
SF
3481
3482 return;
3483}
3484
cb9d1513
SF
3485sub _handle_n_command {
3486 my $self = shift;
3487
3488 return $self->_n_or_s('n', 2);
3489}
3490
3491sub _handle_s_command {
3492 my $self = shift;
3493
3494 return $self->_n_or_s('s', 1);
3495}
3496
573b5003
SF
3497sub _handle_r_command {
3498 my $self = shift;
3499 # r - return from the current subroutine.
3500 if ($DB::cmd eq 'r') {
3501
3502 # Can't do anything if the program's over.
3503 next CMD if DB::_DB__is_finished();
3504
3505 # Turn on stack trace.
3506 $stack[$stack_depth] |= 1;
3507
3508 # Print return value unless the stack is empty.
3509 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3510 last CMD;
3511 }
3512
3513 return;
3514}
3515
d4038e14
SF
3516sub _handle_T_command {
3517 if ($DB::cmd eq 'T') {
3518 DB::print_trace( $OUT, 1 ); # skip DB
3519 next CMD;
3520 }
3521
3522 return;
3523}
3524
b6e88520
SF
3525sub _handle_w_command {
3526 if (my ($arg) = $DB::cmd =~ /\Aw\b\s*(.*)/s) {
3527 DB::cmd_w( 'w', $arg );
3528 next CMD;
3529 }
3530
3531 return;
3532}
3533
25953301
SF
3534sub _handle_W_command {
3535 if (my ($arg) = $DB::cmd =~ /\AW\b\s*(.*)/s) {
3536 DB::cmd_W( 'W', $arg );
3537 next CMD;
3538 }
3539
3540 return;
3541}
3542
14f38b27
SF
3543sub _handle_rc_recall_command {
3544 my $self = shift;
3545
3546 # $rc - recall command.
3547 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3548
3549 # No arguments, take one thing off history.
3550 pop(@hist) if length($DB::cmd) > 1;
3551
3552 # Relative (- found)?
3553 # Y - index back from most recent (by 1 if bare minus)
3554 # N - go to that particular command slot or the last
3555 # thing if nothing following.
14f38b27 3556
9c6fceaf
SF
3557 $self->cmd_verb(
3558 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist ))
3559 );
14f38b27
SF
3560
3561 # Pick out the command desired.
610f01b9 3562 $DB::cmd = $hist[$self->cmd_verb];
14f38b27
SF
3563
3564 # Print the command to be executed and restart the loop
3565 # with that command in the buffer.
3566 print {$OUT} $DB::cmd, "\n";
3567 redo CMD;
3568 }
3569
3570 return;
3571}
3572
0d2c714c
SF
3573sub _handle_rc_search_history_command {
3574 my $self = shift;
3575
3576 # $rc pattern $rc - find a command in the history.
3577 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3578
3579 # Create the pattern to use.
3580 my $pat = "^$arg";
3581 $self->pat($pat);
3582
3583 # Toss off last entry if length is >1 (and it always is).
3584 pop(@hist) if length($DB::cmd) > 1;
3585
9c6fceaf 3586 my $i;
0d2c714c
SF
3587
3588 # Look backward through the history.
3589 SEARCH_HIST:
3590 for ( $i = $#hist ; $i ; --$i ) {
3591 # Stop if we find it.
3592 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3593 }
3594
9c6fceaf 3595 if ( !$i ) {
0d2c714c
SF
3596
3597 # Never found it.
3598 print $OUT "No such command!\n\n";
3599 next CMD;
3600 }
3601
3602 # Found it. Put it in the buffer, print it, and process it.
9c6fceaf 3603 $DB::cmd = $hist[$i];
0d2c714c
SF
3604 print $OUT $DB::cmd, "\n";
3605 redo CMD;
3606 }
b6aeebb8
SF
3607
3608 return;
0d2c714c
SF
3609}
3610
0664c09a
SF
3611sub _handle_H_command {
3612 my $self = shift;
3613
3614 if ($DB::cmd =~ /\AH\b\s*\*/) {
3615 @hist = @truehist = ();
3616 print $OUT "History cleansed\n";
3617 next CMD;
3618 }
3619
3620 if (my ($num)
3621 = $DB::cmd =~ /\AH\b\s*(?:-(\d+))?/) {
3622
3623 # Anything other than negative numbers is ignored by
3624 # the (incorrect) pattern, so this test does nothing.
3625 $end = $num ? ( $#hist - $num ) : 0;
3626
3627 # Set to the minimum if less than zero.
3628 $hist = 0 if $hist < 0;
3629
3630 # Start at the end of the array.
3631 # Stay in while we're still above the ending value.
3632 # Tick back by one each time around the loop.
3633 my $i;
3634
3635 for ( $i = $#hist ; $i > $end ; $i-- ) {
3636
3637 # Print the command unless it has no arguments.
3638 print $OUT "$i: ", $hist[$i], "\n"
3639 unless $hist[$i] =~ /^.?$/;
3640 }
3641
0664c09a
SF
3642 next CMD;
3643 }
3644
3645 return;
3646}
3647
c7b0c61d
SF
3648sub _handle_doc_command {
3649 my $self = shift;
3650
3651 # man, perldoc, doc - show manual pages.
3652 if (my ($man_page)
3653 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) {
3654 runman($man_page);
3655 next CMD;
3656 }
3657
3658 return;
3659}
3660
b6aeebb8
SF
3661sub _handle_p_command {
3662 my $self = shift;
3663
3664 my $print_cmd = 'print {$DB::OUT} ';
3665 # p - print (no args): print $_.
3666 if ($DB::cmd eq 'p') {
3667 $DB::cmd = $print_cmd . '$_';
3668 }
3669
3670 # p - print the given expression.
3671 $DB::cmd =~ s/\Ap\b/$print_cmd /;
3672
3673 return;
3674}
3675
bdb3f37d
SF
3676sub _handle_equal_sign_command {
3677 my $self = shift;
3678
3679 if ($DB::cmd =~ s/\A=\s*//) {
3680 my @keys;
3681 if ( length $DB::cmd == 0 ) {
3682
3683 # No args, get current aliases.
3684 @keys = sort keys %alias;
3685 }
3686 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) {
3687
3688 # Creating a new alias. $k is alias name, $v is
3689 # alias value.
3690
3691 # can't use $_ or kill //g state
3692 for my $x ( $k, $v ) {
3693
3694 # Escape "alarm" characters.
3695 $x =~ s/\a/\\a/g;
3696 }
3697
3698 # Substitute key for value, using alarm chars
3699 # as separators (which is why we escaped them in
3700 # the command).
3701 $alias{$k} = "s\a$k\a$v\a";
3702
3703 # Turn off standard warn and die behavior.
3704 local $SIG{__DIE__};
3705 local $SIG{__WARN__};
3706
3707 # Is it valid Perl?
3708 unless ( eval "sub { s\a$k\a$v\a }; 1" ) {
3709
3710 # Nope. Bad alias. Say so and get out.
3711 print $OUT "Can't alias $k to $v: $@\n";
3712 delete $alias{$k};
3713 next CMD;
3714 }
3715
3716 # We'll only list the new one.
3717 @keys = ($k);
3718 } ## end elsif (my ($k, $v) = ($DB::cmd...
3719
3720 # The argument is the alias to list.
3721 else {
3722 @keys = ($DB::cmd);
3723 }
3724
3725 # List aliases.
3726 for my $k (@keys) {
3727
3728 # Messy metaquoting: Trim the substitution code off.
3729 # We use control-G as the delimiter because it's not
3730 # likely to appear in the alias.
3731 if ( ( my $v = $alias{$k} ) =~ s\as\a$k\a(.*)\a$\a1\a ) {
3732
3733 # Print the alias.
3734 print $OUT "$k\t= $1\n";
3735 }
3736 elsif ( defined $alias{$k} ) {
3737
3738 # Couldn't trim it off; just print the alias code.
3739 print $OUT "$k\t$alias{$k}\n";
3740 }
3741 else {
3742
3743 # No such, dude.
3744 print "No alias for $k\n";
3745 }
3746 } ## end for my $k (@keys)
3747 next CMD;
3748 }
3749
3750 return;
3751}
3752
2ef1dcdb
SF
3753sub _handle_source_command {
3754 my $self = shift;
3755
3756 # source - read commands from a file (or pipe!) and execute.
3757 if (my ($sourced_fn) = $DB::cmd =~ /\Asource\s+(.*\S)/) {
3758 if ( open my $fh, $sourced_fn ) {
3759
3760 # Opened OK; stick it in the list of file handles.
3761 push @cmdfhs, $fh;
3762 }
3763 else {
3764
3765 # Couldn't open it.
3766 DB::warn("Can't execute '$sourced_fn': $!\n");
3767 }
3768 next CMD;
3769 }
3770
3771 return;
3772}
3773
d0ecd4f3
SF
3774sub _handle_enable_disable_commands {
3775 my $self = shift;
3776
3777 if (my ($which_cmd, $position)
3778 = $DB::cmd =~ /\A(enable|disable)\s+(\S+)\s*\z/) {
3779
3780 my ($fn, $line_num);
3781 if ($position =~ m{\A\d+\z})
3782 {
3783 $fn = $DB::filename;
3784 $line_num = $position;
3785 }
3786 elsif (my ($new_fn, $new_line_num)
3787 = $position =~ m{\A(.*):(\d+)\z}) {
3788 ($fn, $line_num) = ($new_fn, $new_line_num);
3789 }
3790 else
3791 {
3792 DB::warn("Wrong spec for enable/disable argument.\n");
3793 }
3794
3795 if (defined($fn)) {
3796 if (DB::_has_breakpoint_data_ref($fn, $line_num)) {
3797 DB::_set_breakpoint_enabled_status($fn, $line_num,
3798 ($which_cmd eq 'enable' ? 1 : '')
3799 );
3800 }
3801 else {
3802 DB::warn("No breakpoint set at ${fn}:${line_num}\n");
3803 }
3804 }
3805
3806 next CMD;
3807 }
3808
3809 return;
3810}
3811
8baafc8b
SF
3812sub _handle_save_command {
3813 my $self = shift;
3814
3815 if (my ($new_fn) = $DB::cmd =~ /\Asave\s*(.*)\z/) {
3816 my $filename = $new_fn || '.perl5dbrc'; # default?
3817 if ( open my $fh, '>', $filename ) {
3818
3819 # chomp to remove extraneous newlines from source'd files
3820 chomp( my @truelist =
3821 map { m/\A\s*(save|source)/ ? "#$_" : $_ }
3822 @truehist );
3823 print {$fh} join( "\n", @truelist );
3824 print "commands saved in $filename\n";
3825 }
3826 else {
3827 DB::warn("Can't save debugger commands in '$new_fn': $!\n");
3828 }
3829