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e22ea7cc 1
b570d64b 2=head1 NAME
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be9a9b1d 4perl5db.pl - the perl debugger
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6=head1 SYNOPSIS
7
8 perl -d your_Perl_script
9
10=head1 DESCRIPTION
11
12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when
13you invoke a script with C<perl -d>. This documentation tries to outline the
14structure and services provided by C<perl5db.pl>, and to describe how you
15can use them.
16
17=head1 GENERAL NOTES
18
19The debugger can look pretty forbidding to many Perl programmers. There are
20a number of reasons for this, many stemming out of the debugger's history.
21
22When the debugger was first written, Perl didn't have a lot of its nicer
23features - no references, no lexical variables, no closures, no object-oriented
24programming. So a lot of the things one would normally have done using such
b570d64b 25features was done using global variables, globs and the C<local()> operator
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26in creative ways.
27
28Some of these have survived into the current debugger; a few of the more
29interesting and still-useful idioms are noted in this section, along with notes
30on the comments themselves.
31
32=head2 Why not use more lexicals?
33
34Experienced Perl programmers will note that the debugger code tends to use
35mostly package globals rather than lexically-scoped variables. This is done
36to allow a significant amount of control of the debugger from outside the
b570d64b 37debugger itself.
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38
39Unfortunately, though the variables are accessible, they're not well
40documented, so it's generally been a decision that hasn't made a lot of
41difference to most users. Where appropriate, comments have been added to
42make variables more accessible and usable, with the understanding that these
be9a9b1d 43I<are> debugger internals, and are therefore subject to change. Future
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44development should probably attempt to replace the globals with a well-defined
45API, but for now, the variables are what we've got.
46
47=head2 Automated variable stacking via C<local()>
48
b570d64b 49As you may recall from reading C<perlfunc>, the C<local()> operator makes a
69893cff 50temporary copy of a variable in the current scope. When the scope ends, the
b570d64b 51old copy is restored. This is often used in the debugger to handle the
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52automatic stacking of variables during recursive calls:
53
54 sub foo {
55 local $some_global++;
56
57 # Do some stuff, then ...
58 return;
59 }
60
61What happens is that on entry to the subroutine, C<$some_global> is localized,
b570d64b 62then altered. When the subroutine returns, Perl automatically undoes the
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63localization, restoring the previous value. Voila, automatic stack management.
64
b570d64b 65The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>,
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66which lets the debugger get control inside of C<eval>'ed code. The debugger
67localizes a saved copy of C<$@> inside the subroutine, which allows it to
68keep C<$@> safe until it C<DB::eval> returns, at which point the previous
b570d64b 69value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep
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70track of C<$@> inside C<eval>s which C<eval> other C<eval's>.
71
72In any case, watch for this pattern. It occurs fairly often.
73
74=head2 The C<^> trick
75
b570d64b 76This is used to cleverly reverse the sense of a logical test depending on
69893cff 77the value of an auxiliary variable. For instance, the debugger's C<S>
b570d64b 78(search for subroutines by pattern) allows you to negate the pattern
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79like this:
80
81 # Find all non-'foo' subs:
b570d64b 82 S !/foo/
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83
84Boolean algebra states that the truth table for XOR looks like this:
85
86=over 4
87
b570d64b 88=item * 0 ^ 0 = 0
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89
90(! not present and no match) --> false, don't print
91
b570d64b 92=item * 0 ^ 1 = 1
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93
94(! not present and matches) --> true, print
95
b570d64b 96=item * 1 ^ 0 = 1
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97
98(! present and no match) --> true, print
99
b570d64b 100=item * 1 ^ 1 = 0
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101
102(! present and matches) --> false, don't print
103
104=back
105
106As you can see, the first pair applies when C<!> isn't supplied, and
be9a9b1d 107the second pair applies when it is. The XOR simply allows us to
b570d64b 108compact a more complicated if-then-elseif-else into a more elegant
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109(but perhaps overly clever) single test. After all, it needed this
110explanation...
111
112=head2 FLAGS, FLAGS, FLAGS
113
114There is a certain C programming legacy in the debugger. Some variables,
be9a9b1d 115such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed
69893cff 116of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces
b570d64b 117of state to be stored independently in a single scalar.
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118
119A test like
120
121 if ($scalar & 4) ...
122
b570d64b 123is checking to see if the appropriate bit is on. Since each bit can be
69893cff 124"addressed" independently in this way, C<$scalar> is acting sort of like
b570d64b 125an array of bits. Obviously, since the contents of C<$scalar> are just a
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126bit-pattern, we can save and restore it easily (it will just look like
127a number).
128
129The problem, is of course, that this tends to leave magic numbers scattered
b570d64b 130all over your program whenever a bit is set, cleared, or checked. So why do
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131it?
132
133=over 4
134
be9a9b1d 135=item *
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be9a9b1d 137First, doing an arithmetical or bitwise operation on a scalar is
69893cff 138just about the fastest thing you can do in Perl: C<use constant> actually
be9a9b1d 139creates a subroutine call, and array and hash lookups are much slower. Is
b570d64b 140this over-optimization at the expense of readability? Possibly, but the
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141debugger accesses these variables a I<lot>. Any rewrite of the code will
142probably have to benchmark alternate implementations and see which is the
b570d64b 143best balance of readability and speed, and then document how it actually
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144works.
145
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146=item *
147
b570d64b 148Second, it's very easy to serialize a scalar number. This is done in
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149the restart code; the debugger state variables are saved in C<%ENV> and then
150restored when the debugger is restarted. Having them be just numbers makes
b570d64b 151this trivial.
69893cff 152
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153=item *
154
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155Third, some of these variables are being shared with the Perl core
156smack in the middle of the interpreter's execution loop. It's much faster for
157a C program (like the interpreter) to check a bit in a scalar than to access
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158several different variables (or a Perl array).
159
160=back
161
162=head2 What are those C<XXX> comments for?
163
164Any comment containing C<XXX> means that the comment is either somewhat
b570d64b 165speculative - it's not exactly clear what a given variable or chunk of
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166code is doing, or that it is incomplete - the basics may be clear, but the
167subtleties are not completely documented.
168
169Send in a patch if you can clear up, fill out, or clarify an C<XXX>.
170
b570d64b 171=head1 DATA STRUCTURES MAINTAINED BY CORE
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172
173There are a number of special data structures provided to the debugger by
174the Perl interpreter.
175
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176The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline>
177via glob assignment) contains the text from C<$filename>, with each
178element corresponding to a single line of C<$filename>. Additionally,
179breakable lines will be dualvars with the numeric component being the
180memory address of a COP node. Non-breakable lines are dualvar to 0.
69893cff 181
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182The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob
183assignment) contains breakpoints and actions. The keys are line numbers;
184you can set individual values, but not the whole hash. The Perl interpreter
69893cff 185uses this hash to determine where breakpoints have been set. Any true value is
be9a9b1d 186considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>.
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187Values are magical in numeric context: 1 if the line is breakable, 0 if not.
188
da052516 189The scalar C<${"_<$filename"}> simply contains the string C<$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
SF
1843
1844 $obj->i_cmd($1);
1845
1846 return;
7013f40c
SF
1847}
1848
2a802473
SF
1849sub _DB__handle_f_command {
1850 if (($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 ($obj) = @_;
1970
1971 if (my ($new_i) = $cmd =~ m#\Ac\b\s*([\w:]*)\s*\z#) {
1972
1973 $obj->i_cmd($new_i);
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.
1980 $subname = $obj->i_cmd;
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.
2003 ( $file, $new_i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ );
2004
2005 # Force the line number to be numeric.
2006 $obj->i_cmd($new_i + 0);
2007
2008 # If we got a line number, we found the sub.
2009 if ($obj->i_cmd) {
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;
2022 my $ii = $obj->i_cmd;
2023 ++$ii while $dbline[$ii] == 0 && $ii < $max;
2024 $obj->i_cmd($ii);
2025 } ## end if ($i)
2026
2027 # We didn't find a sub by that name.
2028 else {
2029 print $OUT "Subroutine $subname not found.\n";
2030 next CMD;
2031 }
2032 } ## end if ($subname =~ /\D/)
2033
2034 # At this point, either the subname was all digits (an
2035 # absolute line-break request) or we've scanned through
2036 # the code following the definition of the sub, looking
2037 # for an executable, which we may or may not have found.
2038 #
2039 # If $i (which we set $subname from) is non-zero, we
2040 # got a request to break at some line somewhere. On
2041 # one hand, if there wasn't any real subroutine name
2042 # involved, this will be a request to break in the current
2043 # file at the specified line, so we have to check to make
2044 # sure that the line specified really is breakable.
2045 #
2046 # On the other hand, if there was a subname supplied, the
2047 # preceding block has moved us to the proper file and
2048 # location within that file, and then scanned forward
2049 # looking for the next executable line. We have to make
2050 # sure that one was found.
2051 #
2052 # On the gripping hand, we can't do anything unless the
2053 # current value of $i points to a valid breakable line.
2054 # Check that.
2055 if ($obj->i_cmd) {
2056
2057 # Breakable?
2058 if ( $dbline[$obj->i_cmd] == 0 ) {
2059 print $OUT "Line " . $obj->i_cmd . " not breakable.\n";
2060 next CMD;
2061 }
2062
2063 # Yes. Set up the one-time-break sigil.
2064 $dbline{$obj->i_cmd} =~ s/($|\0)/;9$1/; # add one-time-only b.p.
2065 _enable_breakpoint_temp_enabled_status($filename, $obj->i_cmd);
2066 } ## end if ($i)
2067
2068 # Turn off stack tracing from here up.
2069 for my $i (0 .. $stack_depth) {
2070 $stack[ $i ] &= ~1;
2071 }
2072 last CMD;
2073 }
2074
2075 return;
2076}
2077
a4d311a3
SF
2078sub _DB__handle_forward_slash_command {
2079 my ($obj) = @_;
2080
2081 # The pattern as a string.
2082 use vars qw($inpat);
2083
2084 if (($inpat) = $cmd =~ m#\A/(.*)\z#) {
2085
2086 # Remove the final slash.
2087 $inpat =~ s:([^\\])/$:$1:;
2088
2089 # If the pattern isn't null ...
2090 if ( $inpat ne "" ) {
2091
2092 # Turn of warn and die procesing for a bit.
2093 local $SIG{__DIE__};
2094 local $SIG{__WARN__};
2095
2096 # Create the pattern.
2097 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a";
2098 if ( $@ ne "" ) {
2099
2100 # Oops. Bad pattern. No biscuit.
2101 # Print the eval error and go back for more
2102 # commands.
2103 print $OUT "$@";
2104 next CMD;
2105 }
2106 $obj->pat($inpat);
2107 } ## end if ($inpat ne "")
2108
2109 # Set up to stop on wrap-around.
2110 $end = $start;
2111
2112 # Don't move off the current line.
2113 $incr = -1;
2114
2115 my $pat = $obj->pat;
2116
2117 # Done in eval so nothing breaks if the pattern
2118 # does something weird.
2119 eval
2120 {
2121 no strict q/vars/;
2122 for (;;) {
2123 # Move ahead one line.
2124 ++$start;
2125
2126 # Wrap if we pass the last line.
2127 $start = 1 if ($start > $max);
2128
2129 # Stop if we have gotten back to this line again,
2130 last if ($start == $end);
2131
2132 # A hit! (Note, though, that we are doing
2133 # case-insensitive matching. Maybe a qr//
2134 # expression would be better, so the user could
2135 # do case-sensitive matching if desired.
2136 if ($dbline[$start] =~ m/$pat/i) {
2137 if ($slave_editor) {
2138 # Handle proper escaping in the slave.
2139 print $OUT "\032\032$filename:$start:0\n";
2140 }
2141 else {
2142 # Just print the line normally.
2143 print $OUT "$start:\t",$dbline[$start],"\n";
2144 }
2145 # And quit since we found something.
2146 last;
2147 }
2148 }
2149 };
2150
2151 if ($@) {
2152 warn $@;
2153 }
2154
2155 # If we wrapped, there never was a match.
2156 if ( $start == $end ) {
2157 print {$OUT} "/$pat/: not found\n";
2158 }
2159 next CMD;
2160 }
2161
2162 return;
2163}
2164
11f0f050
SF
2165sub _DB__handle_question_mark_command {
2166 my ($obj) = @_;
2167
2168 # ? - backward pattern search.
2169 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) {
2170
2171 # Get the pattern, remove trailing question mark.
2172 $inpat =~ s:([^\\])\?$:$1:;
2173
2174 # If we've got one ...
2175 if ( $inpat ne "" ) {
2176
2177 # Turn off die & warn handlers.
2178 local $SIG{__DIE__};
2179 local $SIG{__WARN__};
2180 eval '$inpat =~ m' . "\a$inpat\a";
2181
2182 if ( $@ ne "" ) {
2183
2184 # Ouch. Not good. Print the error.
2185 print $OUT $@;
2186 next CMD;
2187 }
2188 $obj->pat($inpat);
2189 } ## end if ($inpat ne "")
2190
2191 # Where we are now is where to stop after wraparound.
2192 $end = $start;
2193
2194 # Don't move away from this line.
2195 $incr = -1;
2196
2197 my $pat = $obj->pat;
2198 # Search inside the eval to prevent pattern badness
2199 # from killing us.
2200 eval {
2201 no strict q/vars/;
2202 for (;;) {
2203 # Back up a line.
2204 --$start;
2205
2206 # Wrap if we pass the first line.
2207
2208 $start = $max if ($start <= 0);
2209
2210 # Quit if we get back where we started,
2211 last if ($start == $end);
2212
2213 # Match?
2214 if ($dbline[$start] =~ m/$pat/i) {
2215 if ($slave_editor) {
2216 # Yep, follow slave editor requirements.
2217 print $OUT "\032\032$filename:$start:0\n";
2218 }
2219 else {
2220 # Yep, just print normally.
2221 print $OUT "$start:\t",$dbline[$start],"\n";
2222 }
2223
2224 # Found, so done.
2225 last;
2226 }
2227 }
2228 };
2229
2230 # Say we failed if the loop never found anything,
2231 if ( $start == $end ) {
2232 print {$OUT} "?$pat?: not found\n";
2233 }
2234 next CMD;
2235 }
2236
2237 return;
2238}
2239
5f166812
SF
2240sub _DB__handle_restart_and_rerun_commands {
2241 my ($obj) = @_;
2242
2243 # R - restart execution.
2244 # rerun - controlled restart execution.
2245 if (my ($cmd_cmd, $cmd_params) =
2246 $cmd =~ /\A((?:R)|(?:rerun\s*(.*)))\z/) {
2247 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params));
2248
2249 # Close all non-system fds for a clean restart. A more
2250 # correct method would be to close all fds that were not
2251 # open when the process started, but this seems to be
2252 # hard. See "debugger 'R'estart and open database
2253 # connections" on p5p.
2254
2255 my $max_fd = 1024; # default if POSIX can't be loaded
2256 if (eval { require POSIX }) {
2257 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) };
2258 }
2259
2260 if (defined $max_fd) {
2261 foreach ($^F+1 .. $max_fd-1) {
2262 next unless open FD_TO_CLOSE, "<&=$_";
2263 close(FD_TO_CLOSE);
2264 }
2265 }
2266
2267 # And run Perl again. We use exec() to keep the
2268 # PID stable (and that way $ini_pids is still valid).
2269 exec(@args) or print {$OUT} "exec failed: $!\n";
2270
2271 last CMD;
2272 }
2273
2274 return;
2275}
2276
33f361f5
SF
2277sub _DB__handle_run_command_in_pager_command {
2278 my ($obj) = @_;
2279
2280 if ($cmd =~ m#\A\|\|?\s*[^|]#) {
2281 if ( $pager =~ /^\|/ ) {
2282
2283 # Default pager is into a pipe. Redirect I/O.
2284 open( SAVEOUT, ">&STDOUT" )
2285 || DB::warn("Can't save STDOUT");
2286 open( STDOUT, ">&OUT" )
2287 || DB::warn("Can't redirect STDOUT");
2288 } ## end if ($pager =~ /^\|/)
2289 else {
2290
2291 # Not into a pipe. STDOUT is safe.
2292 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT");
2293 }
2294
2295 # Fix up environment to record we have less if so.
2296 fix_less();
2297
2298 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) {
2299
2300 # Couldn't open pipe to pager.
2301 DB::warn("Can't pipe output to '$pager'");
2302 if ( $pager =~ /^\|/ ) {
2303
2304 # Redirect I/O back again.
2305 open( OUT, ">&STDOUT" ) # XXX: lost message
2306 || DB::warn("Can't restore DB::OUT");
2307 open( STDOUT, ">&SAVEOUT" )
2308 || DB::warn("Can't restore STDOUT");
2309 close(SAVEOUT);
2310 } ## end if ($pager =~ /^\|/)
2311 else {
2312
2313 # Redirect I/O. STDOUT already safe.
2314 open( OUT, ">&STDOUT" ) # XXX: lost message
2315 || DB::warn("Can't restore DB::OUT");
2316 }
2317 next CMD;
2318 } ## end unless ($piped = open(OUT,...
2319
2320 # Set up broken-pipe handler if necessary.
2321 $SIG{PIPE} = \&DB::catch
2322 if $pager =~ /^\|/
2323 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} );
2324
2325 OUT->autoflush(1);
2326 # Save current filehandle, and put it back.
2327 $obj->selected(scalar( select(OUT) ));
2328 # Don't put it back if pager was a pipe.
2329 if ($cmd !~ /\A\|\|/)
2330 {
2331 select($obj->selected());
2332 $obj->selected("");
2333 }
2334
2335 # Trim off the pipe symbols and run the command now.
2336 $cmd =~ s#\A\|+\s*##;
2337 redo PIPE;
2338 }
2339
2340 return;
2341}
2342
321095c5
SF
2343sub _DB__handle_m_command {
2344 my ($obj) = @_;
2345
2346 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) {
2347 methods($1);
2348 next CMD;
2349 }
2350
2351 # m expr - set up DB::eval to do the work
2352 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval()
2353 $onetimeDump = 'methods'; # method output gets used there
2354 }
2355
2356 return;
2357}
33f361f5 2358
8e4cceb9
SF
2359sub _DB__at_end_of_every_command {
2360 my ($obj) = @_;
2361
2362 # At the end of every command:
2363 if ($obj->piped) {
2364
2365 # Unhook the pipe mechanism now.
2366 if ( $pager =~ /^\|/ ) {
2367
2368 # No error from the child.
2369 $? = 0;
2370
2371 # we cannot warn here: the handle is missing --tchrist
2372 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n";
2373
2374 # most of the $? crud was coping with broken cshisms
2375 # $? is explicitly set to 0, so this never runs.
2376 if ($?) {
2377 print SAVEOUT "Pager '$pager' failed: ";
2378 if ( $? == -1 ) {
2379 print SAVEOUT "shell returned -1\n";
2380 }
2381 elsif ( $? >> 8 ) {
2382 print SAVEOUT ( $? & 127 )
2383 ? " (SIG#" . ( $? & 127 ) . ")"
2384 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n";
2385 }
2386 else {
2387 print SAVEOUT "status ", ( $? >> 8 ), "\n";
2388 }
2389 } ## end if ($?)
2390
2391 # Reopen filehandle for our output (if we can) and
2392 # restore STDOUT (if we can).
2393 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT");
2394 open( STDOUT, ">&SAVEOUT" )
2395 || &warn("Can't restore STDOUT");
2396
2397 # Turn off pipe exception handler if necessary.
2398 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch;
2399
2400 # Will stop ignoring SIGPIPE if done like nohup(1)
2401 # does SIGINT but Perl doesn't give us a choice.
2402 } ## end if ($pager =~ /^\|/)
2403 else {
2404
2405 # Non-piped "pager". Just restore STDOUT.
2406 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT");
2407 }
2408
2409 # Close filehandle pager was using, restore the normal one
2410 # if necessary,
2411 close(SAVEOUT);
2412
2413 if ($obj->selected() ne "") {
2414 select($obj->selected);
2415 $obj->selected("");
2416 }
2417
2418 # No pipes now.
2419 $obj->piped("");
2420 } ## end if ($piped)
2421
2422 return;
2423}
2424
47e3b8cc
SF
2425# 't' is type.
2426# 'm' is method.
2427# 'v' is the value (i.e: method name or subroutine ref).
2428# 's' is subroutine.
2429my %cmd_lookup =
2430(
c9a9a6c0 2431 '-' => { t => 'm', v => '_handle_dash_command', },
d478d7a0 2432 '.' => { t => 's', v => \&_DB__handle_dot_command, },
8f144dfc
SF
2433 '=' => { t => 'm', v => '_handle_equal_sign_command', },
2434 'H' => { t => 'm', v => '_handle_H_command', },
c9a9a6c0
SF
2435 'S' => { t => 'm', v => '_handle_S_command', },
2436 'T' => { t => 'm', v => '_handle_T_command', },
8f144dfc 2437 'W' => { t => 'm', v => '_handle_W_command', },
c9a9a6c0 2438 'c' => { t => 's', v => \&_DB__handle_c_command, },
d478d7a0
SF
2439 'f' => { t => 's', v => \&_DB__handle_f_command, },
2440 'm' => { t => 's', v => \&_DB__handle_m_command, },
c9a9a6c0 2441 'n' => { t => 'm', v => '_handle_n_command', },
8f144dfc 2442 'p' => { t => 'm', v => '_handle_p_command', },
d478d7a0 2443 'q' => { t => 'm', v => '_handle_q_command', },
c9a9a6c0
SF
2444 'r' => { t => 'm', v => '_handle_r_command', },
2445 's' => { t => 'm', v => '_handle_s_command', },
8f144dfc
SF
2446 'save' => { t => 'm', v => '_handle_save_command', },
2447 'source' => { t => 'm', v => '_handle_source_command', },
d478d7a0 2448 't' => { t => 'm', v => '_handle_t_command', },
8f144dfc 2449 'w' => { t => 'm', v => '_handle_w_command', },
d478d7a0 2450 'x' => { t => 'm', v => '_handle_x_command', },
c9a9a6c0 2451 'y' => { t => 's', v => \&_DB__handle_y_command, },
d478d7a0
SF
2452 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, }
2453 ('X', 'V')),
8f144dfc
SF
2454 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, }
2455 qw(enable disable)),
2456 (map { $_ =>
2457 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, },
2458 } qw(R rerun)),
fbe9ebae
SF
2459 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, }
2460 qw(a A b B e E h i l L M o O P v w W)),
47e3b8cc
SF
2461);
2462
2b0b9dd1
SF
2463sub DB {
2464
2465 # lock the debugger and get the thread id for the prompt
2466 lock($DBGR);
2467 my $tid;
2468 my $position;
2469 my ($prefix, $after, $infix);
2470 my $pat;
22fc883d 2471 my $explicit_stop;
33f361f5
SF
2472 my $piped;
2473 my $selected;
2b0b9dd1
SF
2474
2475 if ($ENV{PERL5DB_THREADED}) {
2476 $tid = eval { "[".threads->tid."]" };
2477 }
2478
35cd713a
SF
2479 my $i;
2480
22fc883d
SF
2481 my $obj = DB::Obj->new(
2482 {
2483 position => \$position,
2484 prefix => \$prefix,
2485 after => \$after,
2486 explicit_stop => \$explicit_stop,
2487 infix => \$infix,
35cd713a 2488 i_cmd => \$i,
a4d311a3 2489 pat => \$pat,
33f361f5
SF
2490 piped => \$piped,
2491 selected => \$selected,
22fc883d
SF
2492 },
2493 );
2494
2495 $obj->_DB_on_init__initialize_globals(@_);
2b0b9dd1 2496
69893cff
RGS
2497 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W.
2498 # The code being debugged may have altered them.
d338d6fe 2499 &save;
69893cff
RGS
2500
2501 # Since DB::DB gets called after every line, we can use caller() to
2502 # figure out where we last were executing. Sneaky, eh? This works because
e22ea7cc 2503 # caller is returning all the extra information when called from the
69893cff 2504 # debugger.
e22ea7cc 2505 local ( $package, $filename, $line ) = caller;
6b24a4b7 2506 $filename_ini = $filename;
69893cff
RGS
2507
2508 # set up the context for DB::eval, so it can properly execute
2509 # code on behalf of the user. We add the package in so that the
2510 # code is eval'ed in the proper package (not in the debugger!).
6b24a4b7 2511 local $usercontext = _calc_usercontext($package);
69893cff
RGS
2512
2513 # Create an alias to the active file magical array to simplify
2514 # the code here.
e22ea7cc 2515 local (*dbline) = $main::{ '_<' . $filename };
aa057b67 2516
69893cff 2517 # Last line in the program.
55783941 2518 $max = $#dbline;
69893cff 2519
22fc883d 2520 _DB__determine_if_we_should_break(@_);
69893cff
RGS
2521
2522 # Preserve the current stop-or-not, and see if any of the W
2523 # (watch expressions) has changed.
36477c24 2524 my $was_signal = $signal;
69893cff
RGS
2525
2526 # If we have any watch expressions ...
22fc883d 2527 $obj->_DB__handle_watch_expressions(@_);
69893cff
RGS
2528
2529=head2 C<watchfunction()>
2530
2531C<watchfunction()> is a function that can be defined by the user; it is a
b570d64b 2532function which will be run on each entry to C<DB::DB>; it gets the
69893cff
RGS
2533current package, filename, and line as its parameters.
2534
b570d64b 2535The watchfunction can do anything it likes; it is executing in the
69893cff
RGS
2536debugger's context, so it has access to all of the debugger's internal
2537data structures and functions.
2538
2539C<watchfunction()> can control the debugger's actions. Any of the following
2540will cause the debugger to return control to the user's program after
2541C<watchfunction()> executes:
2542
b570d64b 2543=over 4
69893cff 2544
be9a9b1d
AT
2545=item *
2546
2547Returning a false value from the C<watchfunction()> itself.
2548
2549=item *
2550
2551Altering C<$single> to a false value.
2552
2553=item *
69893cff 2554
be9a9b1d 2555Altering C<$signal> to a false value.
69893cff 2556
be9a9b1d 2557=item *
69893cff 2558
be9a9b1d 2559Turning off the C<4> bit in C<$trace> (this also disables the
69893cff
RGS
2560check for C<watchfunction()>. This can be done with
2561
2562 $trace &= ~4;
2563
2564=back
2565
2566=cut
2567
e22ea7cc 2568 # If there's a user-defined DB::watchfunction, call it with the
69893cff
RGS
2569 # current package, filename, and line. The function executes in
2570 # the DB:: package.
e22ea7cc
RF
2571 if ( $trace & 4 ) { # User-installed watch
2572 return
2573 if watchfunction( $package, $filename, $line )
2574 and not $single
2575 and not $was_signal
2576 and not( $trace & ~4 );
69893cff
RGS
2577 } ## end if ($trace & 4)
2578
e22ea7cc 2579 # Pick up any alteration to $signal in the watchfunction, and
69893cff 2580 # turn off the signal now.
6027b9a3 2581 $was_signal = $signal;
69893cff
RGS
2582 $signal = 0;
2583
2584=head2 GETTING READY TO EXECUTE COMMANDS
2585
2586The debugger decides to take control if single-step mode is on, the
2587C<t> command was entered, or the user generated a signal. If the program
2588has fallen off the end, we set things up so that entering further commands
2589won't cause trouble, and we say that the program is over.
2590
2591=cut
2592
8dc67a69
SF
2593 # Make sure that we always print if asked for explicitly regardless
2594 # of $trace_to_depth .
22fc883d 2595 $explicit_stop = ($single || $was_signal);
8dc67a69 2596
69893cff
RGS
2597 # Check to see if we should grab control ($single true,
2598 # trace set appropriately, or we got a signal).
8dc67a69 2599 if ( $explicit_stop || ( $trace & 1 ) ) {
22fc883d 2600 $obj->_DB__grab_control(@_);
69893cff
RGS
2601 } ## end if ($single || ($trace...
2602
2603=pod
2604
2605If there's an action to be executed for the line we stopped at, execute it.
b570d64b 2606If there are any preprompt actions, execute those as well.
e219e2fb
RF
2607
2608=cut
2609
69893cff 2610 # If there's an action, do it now.
05da04df
SF
2611 if ($action) {
2612 $evalarg = $action;
2613 DB::eval();
2614 }
e219e2fb 2615
69893cff
RGS
2616 # Are we nested another level (e.g., did we evaluate a function
2617 # that had a breakpoint in it at the debugger prompt)?
e22ea7cc
RF
2618 if ( $single || $was_signal ) {
2619
69893cff 2620 # Yes, go down a level.
e22ea7cc 2621 local $level = $level + 1;
69893cff
RGS
2622
2623 # Do any pre-prompt actions.
e22ea7cc 2624 foreach $evalarg (@$pre) {
7c54f46a 2625 DB::eval();
e22ea7cc 2626 }
69893cff
RGS
2627
2628 # Complain about too much recursion if we passed the limit.
05da04df
SF
2629 if ($single & 4) {
2630 print $OUT $stack_depth . " levels deep in subroutine calls!\n";
2631 }
69893cff
RGS
2632
2633 # The line we're currently on. Set $incr to -1 to stay here
2634 # until we get a command that tells us to advance.
e22ea7cc
RF
2635 $start = $line;
2636 $incr = -1; # for backward motion.
69893cff
RGS
2637
2638 # Tack preprompt debugger actions ahead of any actual input.
e22ea7cc 2639 @typeahead = ( @$pretype, @typeahead );
69893cff
RGS
2640
2641=head2 WHERE ARE WE?
2642
2643XXX Relocate this section?
2644
2645The debugger normally shows the line corresponding to the current line of
2646execution. Sometimes, though, we want to see the next line, or to move elsewhere
2647in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables.
2648
be9a9b1d
AT
2649C<$incr> controls by how many lines the I<current> line should move forward
2650after a command is executed. If set to -1, this indicates that the I<current>
69893cff
RGS
2651line shouldn't change.
2652
be9a9b1d 2653C<$start> is the I<current> line. It is used for things like knowing where to
69893cff
RGS
2654move forwards or backwards from when doing an C<L> or C<-> command.
2655
2656C<$max> tells the debugger where the last line of the current file is. It's
2657used to terminate loops most often.
2658
2659=head2 THE COMMAND LOOP
2660
2661Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes
2662in two parts:
2663
2664=over 4
2665
be9a9b1d
AT
2666=item *
2667
2668The outer part of the loop, starting at the C<CMD> label. This loop
69893cff
RGS
2669reads a command and then executes it.
2670
be9a9b1d
AT
2671=item *
2672
2673The inner part of the loop, starting at the C<PIPE> label. This part
69893cff
RGS
2674is wholly contained inside the C<CMD> block and only executes a command.
2675Used to handle commands running inside a pager.
2676
2677=back
2678
2679So why have two labels to restart the loop? Because sometimes, it's easier to
2680have a command I<generate> another command and then re-execute the loop to do
2681the new command. This is faster, but perhaps a bit more convoluted.
2682
2683=cut
2684
2685 # The big command dispatch loop. It keeps running until the
2686 # user yields up control again.
2687 #
2688 # If we have a terminal for input, and we get something back
2689 # from readline(), keep on processing.
6b24a4b7 2690
e22ea7cc 2691 CMD:
32bbadc6 2692 while (_DB__read_next_cmd($tid))
69893cff 2693 {
e22ea7cc 2694
8380a245 2695 share($cmd);
69893cff
RGS
2696 # ... try to execute the input as debugger commands.
2697
2698 # Don't stop running.
2699 $single = 0;
2700
2701 # No signal is active.
2702 $signal = 0;
2703
2704 # Handle continued commands (ending with \):
3d7a2a93 2705 if ($cmd =~ s/\\\z/\n/) {
eeb7da96 2706 $cmd .= DB::readline(" cont: ");
e22ea7cc 2707 redo CMD;
3d7a2a93 2708 }
69893cff
RGS
2709
2710=head4 The null command
2711
be9a9b1d 2712A newline entered by itself means I<re-execute the last command>. We grab the
69893cff
RGS
2713command out of C<$laststep> (where it was recorded previously), and copy it
2714back into C<$cmd> to be executed below. If there wasn't any previous command,
2715we'll do nothing below (no command will match). If there was, we also save it
2716in the command history and fall through to allow the command parsing to pick
2717it up.
2718
2719=cut
2720
2721 # Empty input means repeat the last command.
eeb7da96
SF
2722 if ($cmd eq '') {
2723 $cmd = $laststep;
2724 }
e22ea7cc 2725 chomp($cmd); # get rid of the annoying extra newline
eeb7da96
SF
2726 if (length($cmd) >= 2) {
2727 push( @hist, $cmd );
2728 }
e22ea7cc 2729 push( @truehist, $cmd );
2dbd01ad
SF
2730 share(@hist);
2731 share(@truehist);
e22ea7cc
RF
2732
2733 # This is a restart point for commands that didn't arrive
2734 # via direct user input. It allows us to 'redo PIPE' to
2735 # re-execute command processing without reading a new command.
69893cff 2736 PIPE: {
af84fb69 2737 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2738
2739=head3 COMMAND ALIASES
2740
2741The debugger can create aliases for commands (these are stored in the
2742C<%alias> hash). Before a command is executed, the command loop looks it up
2743in the alias hash and substitutes the contents of the alias for the command,
2744completely replacing it.
2745
2746=cut
2747
2748 # See if there's an alias for the command, and set it up if so.
e22ea7cc
RF
2749 if ( $alias{$i} ) {
2750
69893cff
RGS
2751 # Squelch signal handling; we want to keep control here
2752 # if something goes loco during the alias eval.
2753 local $SIG{__DIE__};
2754 local $SIG{__WARN__};
2755
2756 # This is a command, so we eval it in the DEBUGGER's
2757 # scope! Otherwise, we can't see the special debugger
2758 # variables, or get to the debugger's subs. (Well, we
2759 # _could_, but why make it even more complicated?)
2760 eval "\$cmd =~ $alias{$i}";
2761 if ($@) {
2762 local $\ = '';
1f874cb6 2763 print $OUT "Couldn't evaluate '$i' alias: $@";
69893cff
RGS
2764 next CMD;
2765 }
af84fb69 2766 _DB__trim_command_and_return_first_component($obj);
69893cff
RGS
2767 } ## end if ($alias{$i})
2768
2769=head3 MAIN-LINE COMMANDS
2770
2771All of these commands work up to and after the program being debugged has
b570d64b 2772terminated.
69893cff
RGS
2773
2774=head4 C<q> - quit
2775
b570d64b 2776Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't
69893cff
RGS
2777try to execute further, cleaning any restart-related stuff out of the
2778environment, and executing with the last value of C<$?>.
2779
2780=cut
2781
fbe9ebae
SF
2782 # All of these commands were remapped in perl 5.8.0;
2783 # we send them off to the secondary dispatcher (see below).
2784 $obj->_handle_special_char_cmd_wrapper_commands;
af84fb69 2785 _DB__trim_command_and_return_first_component($obj);
fbe9ebae 2786
47e3b8cc
SF
2787 if (my $cmd_rec = $cmd_lookup{$i}) {
2788 my $type = $cmd_rec->{t};
2789 my $val = $cmd_rec->{v};
2790 if ($type eq 'm') {
2791 $obj->$val();
2792 }
2793 elsif ($type eq 's') {
2794 $val->($obj);
2795 }
2796 }
69893cff 2797
611272bb 2798=head4 C<t> - trace [n]
69893cff
RGS
2799
2800Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.).
611272bb 2801If level is specified, set C<$trace_to_depth>.
69893cff 2802
69893cff
RGS
2803=head4 C<S> - list subroutines matching/not matching a pattern
2804
2805Walks through C<%sub>, checking to see whether or not to print the name.
2806
69893cff
RGS
2807=head4 C<X> - list variables in current package
2808
b570d64b 2809Since the C<V> command actually processes this, just change this to the
69893cff
RGS
2810appropriate C<V> command and fall through.
2811
69893cff
RGS
2812=head4 C<V> - list variables
2813
b570d64b 2814Uses C<dumpvar.pl> to dump out the current values for selected variables.
69893cff 2815
69893cff
RGS
2816=head4 C<x> - evaluate and print an expression
2817
2818Hands the expression off to C<DB::eval>, setting it up to print the value
2819via C<dumpvar.pl> instead of just printing it directly.
2820
69893cff
RGS
2821=head4 C<m> - print methods
2822
2823Just uses C<DB::methods> to determine what methods are available.
2824
69893cff
RGS
2825=head4 C<f> - switch files
2826
73decac7 2827Switch to a different filename.
69893cff 2828
69893cff
RGS
2829=head4 C<.> - return to last-executed line.
2830
2831We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead,
2832and then we look up the line in the magical C<%dbline> hash.
2833
69893cff
RGS
2834=head4 C<-> - back one window
2835
2836We change C<$start> to be one window back; if we go back past the first line,
2837we set it to be the first line. We ser C<$incr> to put us back at the
2838currently-executing line, and then put a C<l $start +> (list one window from
2839C<$start>) in C<$cmd> to be executed later.
2840
8481f647 2841=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>>
69893cff
RGS
2842
2843In Perl 5.8.0, a realignment of the commands was done to fix up a number of
2844problems, most notably that the default case of several commands destroying
2845the user's work in setting watchpoints, actions, etc. We wanted, however, to
2846retain the old commands for those who were used to using them or who preferred
2847them. At this point, we check for the new commands and call C<cmd_wrapper> to
2848deal with them instead of processing them in-line.
2849
69893cff
RGS
2850=head4 C<y> - List lexicals in higher scope
2851
826b9a2e 2852Uses C<PadWalker> to find the lexicals supplied as arguments in a scope
69893cff
RGS
2853above the current one and then displays then using C<dumpvar.pl>.
2854
69893cff
RGS
2855=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS
2856
2857All of the commands below this point don't work after the program being
2858debugged has ended. All of them check to see if the program has ended; this
2859allows the commands to be relocated without worrying about a 'line of
2860demarcation' above which commands can be entered anytime, and below which
2861they can't.
2862
2863=head4 C<n> - single step, but don't trace down into subs
2864
2865Done by setting C<$single> to 2, which forces subs to execute straight through
be9a9b1d 2866when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>,
826b9a2e 2867so a null command knows what to re-execute.
69893cff 2868
69893cff
RGS
2869=head4 C<s> - single-step, entering subs
2870
826b9a2e 2871Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside
69893cff
RGS
2872subs. Also saves C<s> as C<$lastcmd>.
2873
69893cff
RGS
2874=head4 C<c> - run continuously, setting an optional breakpoint
2875
2876Most of the code for this command is taken up with locating the optional
2877breakpoint, which is either a subroutine name or a line number. We set
2878the appropriate one-time-break in C<@dbline> and then turn off single-stepping
2879in this and all call levels above this one.
2880
69893cff
RGS
2881=head4 C<r> - return from a subroutine
2882
2883For C<r> to work properly, the debugger has to stop execution again
2884immediately after the return is executed. This is done by forcing
2885single-stepping to be on in the call level above the current one. If
2886we are printing return values when a C<r> is executed, set C<$doret>
2887appropriately, and force us out of the command loop.
2888
69893cff
RGS
2889=head4 C<T> - stack trace
2890
2891Just calls C<DB::print_trace>.
2892
69893cff
RGS
2893=head4 C<w> - List window around current line.
2894
2895Just calls C<DB::cmd_w>.
2896
69893cff
RGS
2897=head4 C<W> - watch-expression processing.
2898
b570d64b 2899Just calls C<DB::cmd_W>.
69893cff 2900
69893cff
RGS
2901=head4 C</> - search forward for a string in the source
2902
ef18ae63 2903We take the argument and treat it as a pattern. If it turns out to be a
69893cff 2904bad one, we return the error we got from trying to C<eval> it and exit.
ef18ae63 2905If not, we create some code to do the search and C<eval> it so it can't
69893cff
RGS
2906mess us up.
2907
2908=cut
2909
a4d311a3 2910 _DB__handle_forward_slash_command($obj);
69893cff
RGS
2911
2912=head4 C<?> - search backward for a string in the source
2913
2914Same as for C</>, except the loop runs backwards.
2915
2916=cut
2917
11f0f050 2918 _DB__handle_question_mark_command($obj);
69893cff
RGS
2919
2920=head4 C<$rc> - Recall command
2921
2922Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports
2923that the terminal supports history). It find the the command required, puts it
2924into C<$cmd>, and redoes the loop to execute it.
2925
2926=cut
2927
e22ea7cc 2928 # $rc - recall command.
14f38b27 2929 $obj->_handle_rc_recall_command;
69893cff
RGS
2930
2931=head4 C<$sh$sh> - C<system()> command
2932
2933Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and
2934C<STDOUT> from getting messed up.
2935
2936=cut
2937
466f24c7 2938 $obj->_handle_sh_command;
69893cff
RGS
2939
2940=head4 C<$rc I<pattern> $rc> - Search command history
2941
2942Another command to manipulate C<@hist>: this one searches it with a pattern.
be9a9b1d 2943If a command is found, it is placed in C<$cmd> and executed via C<redo>.
69893cff
RGS
2944
2945=cut
2946
0d2c714c 2947 $obj->_handle_rc_search_history_command;
69893cff 2948
ef18ae63 2949=head4 C<$sh> - Invoke a shell
69893cff
RGS
2950
2951Uses C<DB::system> to invoke a shell.
2952
2953=cut
2954
69893cff
RGS
2955=head4 C<$sh I<command>> - Force execution of a command in a shell
2956
2957Like the above, but the command is passed to the shell. Again, we use
2958C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>.
2959
69893cff
RGS
2960=head4 C<H> - display commands in history
2961
2962Prints the contents of C<@hist> (if any).
2963
69893cff
RGS
2964=head4 C<man, doc, perldoc> - look up documentation
2965
2966Just calls C<runman()> to print the appropriate document.
2967
2968=cut
2969
c7b0c61d 2970 $obj->_handle_doc_command;
69893cff
RGS
2971
2972=head4 C<p> - print
2973
2974Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at
2975the bottom of the loop.
2976
69893cff
RGS
2977=head4 C<=> - define command alias
2978
2979Manipulates C<%alias> to add or list command aliases.
2980
69893cff
RGS
2981=head4 C<source> - read commands from a file.
2982
2983Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will
2984pick it up.
2985
d0ecd4f3 2986=head4 C<enable> C<disable> - enable or disable breakpoints
e09195af 2987
d0ecd4f3 2988This enables or disables breakpoints.
e09195af 2989
69893cff
RGS
2990=head4 C<save> - send current history to a file
2991
2992Takes the complete history, (not the shrunken version you see with C<H>),
2993and saves it to the given filename, so it can be replayed using C<source>.
2994
2995Note that all C<^(save|source)>'s are commented out with a view to minimise recursion.
2996
7fddc82f
RF
2997=head4 C<R> - restart
2998
ef18ae63 2999Restart the debugger session.
7fddc82f
RF
3000
3001=head4 C<rerun> - rerun the current session
3002
3003Return to any given position in the B<true>-history list
3004
69893cff
RGS
3005=head4 C<|, ||> - pipe output through the pager.
3006
be9a9b1d 3007For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT>
69893cff
RGS
3008(the program's standard output). For C<||>, we only save C<OUT>. We open a
3009pipe to the pager (restoring the output filehandles if this fails). If this
b570d64b 3010is the C<|> command, we also set up a C<SIGPIPE> handler which will simply
69893cff
RGS
3011set C<$signal>, sending us back into the debugger.
3012
3013We then trim off the pipe symbols and C<redo> the command loop at the
3014C<PIPE> label, causing us to evaluate the command in C<$cmd> without
3015reading another.
3016
3017=cut
3018
3019 # || - run command in the pager, with output to DB::OUT.
33f361f5 3020 _DB__handle_run_command_in_pager_command($obj);
69893cff
RGS
3021
3022=head3 END OF COMMAND PARSING
3023
ff41e38d
SF
3024Anything left in C<$cmd> at this point is a Perl expression that we want to
3025evaluate. We'll always evaluate in the user's context, and fully qualify
69893cff
RGS
3026any variables we might want to address in the C<DB> package.
3027
3028=cut
3029
e22ea7cc 3030 } # PIPE:
69893cff 3031
e22ea7cc 3032 # Make sure the flag that says "the debugger's running" is
69893cff 3033 # still on, to make sure we get control again.
e22ea7cc 3034 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd";
69893cff
RGS
3035
3036 # Run *our* eval that executes in the caller's context.
7c54f46a 3037 DB::eval();
69893cff
RGS
3038
3039 # Turn off the one-time-dump stuff now.
e22ea7cc
RF
3040 if ($onetimeDump) {
3041 $onetimeDump = undef;
69893cff 3042 $onetimedumpDepth = undef;
e22ea7cc
RF
3043 }
3044 elsif ( $term_pid == $$ ) {
8380a245 3045 eval { # May run under miniperl, when not available...
c7e68384
IZ
3046 STDOUT->flush();
3047 STDERR->flush();
8380a245 3048 };
e22ea7cc 3049
69893cff 3050 # XXX If this is the master pid, print a newline.
8380a245 3051 print {$OUT} "\n";
e22ea7cc
RF
3052 }
3053 } ## end while (($term || &setterm...
69893cff
RGS
3054
3055=head3 POST-COMMAND PROCESSING
3056
3057After each command, we check to see if the command output was piped anywhere.
3058If so, we go through the necessary code to unhook the pipe and go back to
3059our standard filehandles for input and output.
3060
3061=cut
3062
e22ea7cc 3063 continue { # CMD:
8e4cceb9 3064 _DB__at_end_of_every_command($obj);
e22ea7cc 3065 } # CMD:
69893cff
RGS
3066
3067=head3 COMMAND LOOP TERMINATION
3068
3069When commands have finished executing, we come here. If the user closed the
3070input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We
3071evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>,
3072C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter.
3073The interpreter will then execute the next line and then return control to us
3074again.
3075
3076=cut
3077
3078 # No more commands? Quit.
1f874cb6 3079 $fall_off_end = 1 unless defined $cmd; # Emulate 'q' on EOF
69893cff
RGS
3080
3081 # Evaluate post-prompt commands.
e22ea7cc 3082 foreach $evalarg (@$post) {
7c54f46a 3083 DB::eval();
e22ea7cc
RF
3084 }
3085 } # if ($single || $signal)
69893cff
RGS
3086
3087 # Put the user's globals back where you found them.
e22ea7cc 3088 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved;
69893cff
RGS
3089 ();
3090} ## end sub DB
3091
22fc883d
SF
3092package DB::Obj;
3093
3094sub new {
3095 my $class = shift;
3096
3097 my $self = bless {}, $class;
3098
3099 $self->_init(@_);
3100
3101 return $self;
3102}
3103
3104sub _init {
3105 my ($self, $args) = @_;
3106
3107 %{$self} = (%$self, %$args);
3108
3109 return;
3110}
3111
3112{
3113 no strict 'refs';
a4d311a3 3114 foreach my $slot_name (qw(
33f361f5 3115 after explicit_stop infix pat piped position prefix selected i_cmd
a4d311a3 3116 )) {
22fc883d
SF
3117 my $slot = $slot_name;
3118 *{$slot} = sub {
3119 my $self = shift;
3120
3121 if (@_) {
3122 ${ $self->{$slot} } = shift;
3123 }
3124
3125 return ${ $self->{$slot} };
3126 };
8def6eff
SF
3127
3128 *{"append_to_$slot"} = sub {
3129 my $self = shift;
3130 my $s = shift;
3131
3132 return $self->$slot($self->$slot . $s);
3133 };
22fc883d
SF
3134 }
3135}
3136
3137sub _DB_on_init__initialize_globals
3138{
3139 my $self = shift;
3140
3141 # Check for whether we should be running continuously or not.
3142 # _After_ the perl program is compiled, $single is set to 1:
ebd0282e 3143 if ( $single and not $second_time++ ) {
22fc883d
SF
3144
3145 # Options say run non-stop. Run until we get an interrupt.
ebd0282e 3146 if ($runnonstop) { # Disable until signal
22fc883d
SF
3147 # If there's any call stack in place, turn off single
3148 # stepping into subs throughout the stack.
8ad70697
SF
3149 for my $i (0 .. $stack_depth) {
3150 $stack[ $i ] &= ~1;
22fc883d
SF
3151 }
3152
3153 # And we are now no longer in single-step mode.
ebd0282e 3154 $single = 0;
22fc883d
SF
3155
3156 # If we simply returned at this point, we wouldn't get
3157 # the trace info. Fall on through.
3158 # return;
3159 } ## end if ($runnonstop)
3160
8ad70697 3161 elsif ($ImmediateStop) {
22fc883d
SF
3162
3163 # We are supposed to stop here; XXX probably a break.
8ad70697 3164 $ImmediateStop = 0; # We've processed it; turn it off
ebd0282e 3165 $signal = 1; # Simulate an interrupt to force
22fc883d
SF
3166 # us into the command loop
3167 }
3168 } ## end if ($single and not $second_time...
3169
3170 # If we're in single-step mode, or an interrupt (real or fake)
3171 # has occurred, turn off non-stop mode.
ebd0282e 3172 $runnonstop = 0 if $single or $signal;
22fc883d
SF
3173
3174 return;
3175}
3176
3177sub _DB__handle_watch_expressions
3178{
3179 my $self = shift;
3180
931ac036 3181 if ( $trace & 2 ) {
8ad70697
SF
3182 for my $n (0 .. $#to_watch) {
3183 $evalarg = $to_watch[$n];
3184 local $onetimeDump; # Tell DB::eval() to not output results
22fc883d
SF
3185
3186 # Fix context DB::eval() wants to return an array, but
3187 # we need a scalar here.
7c54f46a 3188 my ($val) = join( "', '", DB::eval() );
22fc883d
SF
3189 $val = ( ( defined $val ) ? "'$val'" : 'undef' );
3190
3191 # Did it change?
8ad70697 3192 if ( $val ne $old_watch[$n] ) {
22fc883d
SF
3193
3194 # Yep! Show the difference, and fake an interrupt.
ebd0282e 3195 $signal = 1;
8ad70697
SF
3196 print {$OUT} <<EOP;
3197Watchpoint $n:\t$to_watch[$n] changed:
3198 old value:\t$old_watch[$n]
22fc883d
SF
3199 new value:\t$val
3200EOP
8ad70697 3201 $old_watch[$n] = $val;
22fc883d
SF
3202 } ## end if ($val ne $old_watch...
3203 } ## end for my $n (0 ..
3204 } ## end if ($trace & 2)
3205
3206 return;
3207}
3208
ad46ac70
SF
3209sub _my_print_lineinfo
3210{
3211 my ($self, $i, $incr_pos) = @_;
3212
18b5b545 3213 if ($frame) {
ad46ac70 3214 # Print it indented if tracing is on.
8ad70697 3215 DB::print_lineinfo( ' ' x $stack_depth,
ad46ac70
SF
3216 "$i:\t$DB::dbline[$i]" . $self->after );
3217 }
3218 else {
3219 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos);
3220 }
3221}
3222
44a07e3e 3223sub _curr_line {
18b5b545 3224 return $DB::dbline[$line];
44a07e3e
SF
3225}
3226
22fc883d
SF
3227sub _DB__grab_control
3228{
3229 my $self = shift;
3230
3231 # Yes, grab control.
7793e5c2 3232 if ($slave_editor) {
22fc883d
SF
3233
3234 # Tell the editor to update its position.
18b5b545 3235 $self->position("\032\032${DB::filename}:$line:0\n");
22fc883d
SF
3236 DB::print_lineinfo($self->position());
3237 }
3238
3239=pod
3240
3241Special check: if we're in package C<DB::fake>, we've gone through the
3242C<END> block at least once. We set up everything so that we can continue
3243to enter commands and have a valid context to be in.
3244
3245=cut
3246
3247 elsif ( $DB::package eq 'DB::fake' ) {
3248
3249 # Fallen off the end already.
3250 if (!$DB::term) {
3251 DB::setterm();
3252 }
3253
3254 DB::print_help(<<EOP);
3255Debugged program terminated. Use B<q> to quit or B<R> to restart,
3256use B<o> I<inhibit_exit> to avoid stopping after program termination,
3257B<h q>, B<h R> or B<h o> to get additional info.
3258EOP
3259
3260 # Set the DB::eval context appropriately.
3261 $DB::package = 'main';
3262 $DB::usercontext = DB::_calc_usercontext($DB::package);
3263 } ## end elsif ($package eq 'DB::fake')
3264
3265=pod
3266
3267If the program hasn't finished executing, we scan forward to the
3268next executable line, print that out, build the prompt from the file and line
3269number information, and print that.
3270
3271=cut
3272
3273 else {
3274
3275
3276 # Still somewhere in the midst of execution. Set up the
3277 # debugger prompt.
3278 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to
3279 # Perl 5 ones (sorry, we don't print Klingon
3280 #module names)
3281
3282 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::'));
8def6eff 3283 $self->append_to_prefix( "$DB::sub(${DB::filename}:" );
44a07e3e 3284 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3285
3286 # Break up the prompt if it's really long.
3287 if ( length($self->prefix()) > 30 ) {
18b5b545 3288 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after);
22fc883d
SF
3289 $self->prefix("");
3290 $self->infix(":\t");
3291 }
3292 else {
3293 $self->infix("):\t");
3294 $self->position(
18b5b545 3295 $self->prefix . $line. $self->infix
44a07e3e 3296 . $self->_curr_line . $self->after
22fc883d
SF
3297 );
3298 }
3299
3300 # Print current line info, indenting if necessary.
18b5b545 3301 $self->_my_print_lineinfo($line, $self->position);
22fc883d 3302
44a07e3e
SF
3303 my $i;
3304 my $line_i = sub { return $DB::dbline[$i]; };
3305
22fc883d
SF
3306 # Scan forward, stopping at either the end or the next
3307 # unbreakable line.
18b5b545 3308 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i )
22fc883d
SF
3309 { #{ vi
3310
3311 # Drop out on null statements, block closers, and comments.
44a07e3e 3312 last if $line_i->() =~ /^\s*[\;\}\#\n]/;
22fc883d
SF
3313
3314 # Drop out if the user interrupted us.
ebd0282e 3315 last if $signal;
22fc883d
SF
3316
3317 # Append a newline if the line doesn't have one. Can happen
3318 # in eval'ed text, for instance.
44a07e3e 3319 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" );
22fc883d
SF
3320
3321 # Next executable line.
44a07e3e 3322 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->()
22fc883d 3323 . $self->after;
8def6eff 3324 $self->append_to_position($incr_pos);
ad46ac70 3325 $self->_my_print_lineinfo($i, $incr_pos);
22fc883d
SF
3326 } ## end for ($i = $line + 1 ; $i...
3327 } ## end else [ if ($slave_editor)
3328
3329 return;
3330}
3331
174f9c5e
SF
3332sub _handle_t_command {
3333 if (my ($levels) = $DB::cmd =~ /\At(?:\s+(\d+))?\z/) {
931ac036 3334 $trace ^= 1;
174f9c5e 3335 local $\ = '';
8ad70697
SF
3336 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9;
3337 print {$OUT} "Trace = "
931ac036 3338 . ( ( $trace & 1 )
174f9c5e
SF
3339 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" )
3340 : "off" ) . "\n";
3341 next CMD;
3342 }
3343
3344 return;
3345}
3346
9d0b71b3
SF
3347
3348sub _handle_S_command {
3349 if (my ($print_all_subs, $should_reverse, $Spatt)
3350 = $DB::cmd =~ /\AS(\s+(!)?(.+))?\z/) {
3351 # $Spatt is the pattern (if any) to use.
3352 # Reverse scan?
3353 my $Srev = defined $should_reverse;
3354 # No args - print all subs.
3355 my $Snocheck = !defined $print_all_subs;
3356
3357 # Need to make these sane here.
3358 local $\ = '';
3359 local $, = '';
3360
3361 # Search through the debugger's magical hash of subs.
3362 # If $nocheck is true, just print the sub name.
3363 # Otherwise, check it against the pattern. We then use
3364 # the XOR trick to reverse the condition as required.
3365 foreach $subname ( sort( keys %sub ) ) {
3366 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) {
3367 print $OUT $subname, "\n";
3368 }
3369 }
3370 next CMD;
3371 }
3372
3373 return;
3374}
3375
1ce985d2
SF
3376sub _handle_V_command_and_X_command {
3377
3378 $DB::cmd =~ s/^X\b/V $DB::package/;
3379
3380 # Bare V commands get the currently-being-debugged package
3381 # added.
3382 if ($DB::cmd eq "V") {
3383 $DB::cmd = "V $DB::package";
3384 }
3385
3386 # V - show variables in package.
3387 if (my ($new_packname, $new_vars_str) =
3388 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) {
3389
3390 # Save the currently selected filehandle and
3391 # force output to debugger's filehandle (dumpvar
3392 # just does "print" for output).
3393 my $savout = select($OUT);
3394
3395 # Grab package name and variables to dump.
3396 $packname = $new_packname;
3397 my @vars = split( ' ', $new_vars_str );
3398
3399 # If main::dumpvar isn't here, get it.
3400 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar;
3401 if ( defined &main::dumpvar ) {
3402
3403 # We got it. Turn off subroutine entry/exit messages
3404 # for the moment, along with return values.
3405 local $frame = 0;
3406 local $doret = -2;
3407
3408 # must detect sigpipe failures - not catching
3409 # then will cause the debugger to die.
3410 eval {
3411 &main::dumpvar(
3412 $packname,
3413 defined $option{dumpDepth}
3414 ? $option{dumpDepth}
3415 : -1, # assume -1 unless specified
3416 @vars
3417 );
3418 };
3419
3420 # The die doesn't need to include the $@, because
3421 # it will automatically get propagated for us.
3422 if ($@) {
3423 die unless $@ =~ /dumpvar print failed/;
3424 }
3425 } ## end if (defined &main::dumpvar)
3426 else {
3427
3428 # Couldn't load dumpvar.
3429 print $OUT "dumpvar.pl not available.\n";
3430 }
3431
3432 # Restore the output filehandle, and go round again.
3433 select($savout);
3434 next CMD;
3435 }
3436
3437 return;
3438}
3439
d1450c23
SF
3440sub _handle_dash_command {
3441
3442 if ($DB::cmd eq '-') {
3443
3444 # back up by a window; go to 1 if back too far.
3445 $start -= $incr + $window + 1;
3446 $start = 1 if $start <= 0;
3447 $incr = $window - 1;
3448
3449 # Generate and execute a "l +" command (handled below).
3450 $DB::cmd = 'l ' . ($start) . '+';
fbe9ebae 3451 redo CMD;
d1450c23
SF
3452 }
3453 return;
3454}
3455
cb9d1513
SF
3456sub _n_or_s_commands_generic {
3457 my ($self, $new_val) = @_;
73c5e526 3458 # n - next
cb9d1513 3459 next CMD if DB::_DB__is_finished();
73c5e526 3460
cb9d1513
SF
3461 # Single step, but don't enter subs.
3462 $single = $new_val;
3463
3464 # Save for empty command (repeat last).
3465 $laststep = $DB::cmd;
3466 last CMD;
3467}
73c5e526 3468
cb9d1513
SF
3469sub _n_or_s {
3470 my ($self, $letter, $new_val) = @_;
3471
3472 if ($DB::cmd eq $letter) {
3473 $self->_n_or_s_commands_generic($new_val);
73c5e526 3474 }
50a8a759
SF
3475 elsif ($DB::cmd =~ m#\A\Q$letter\E\b#) {
3476 $self->_n_or_s_and_arg_commands_generic($letter, $new_val);
3477 }
73c5e526
SF
3478
3479 return;
3480}
3481
cb9d1513
SF
3482sub _handle_n_command {
3483 my $self = shift;
3484
3485 return $self->_n_or_s('n', 2);
3486}
3487
3488sub _handle_s_command {
3489 my $self = shift;
3490
3491 return $self->_n_or_s('s', 1);
3492}
3493
573b5003
SF
3494sub _handle_r_command {
3495 my $self = shift;
3496 # r - return from the current subroutine.
3497 if ($DB::cmd eq 'r') {
3498
3499 # Can't do anything if the program's over.
3500 next CMD if DB::_DB__is_finished();
3501
3502 # Turn on stack trace.
3503 $stack[$stack_depth] |= 1;
3504
3505 # Print return value unless the stack is empty.
3506 $doret = $option{PrintRet} ? $stack_depth - 1 : -2;
3507 last CMD;
3508 }
3509
3510 return;
3511}
3512
d4038e14
SF
3513sub _handle_T_command {
3514 if ($DB::cmd eq 'T') {
3515 DB::print_trace( $OUT, 1 ); # skip DB
3516 next CMD;
3517 }
3518
3519 return;
3520}
3521
b6e88520
SF
3522sub _handle_w_command {
3523 if (my ($arg) = $DB::cmd =~ /\Aw\b\s*(.*)/s) {
3524 DB::cmd_w( 'w', $arg );
3525 next CMD;
3526 }
3527
3528 return;
3529}
3530
25953301
SF
3531sub _handle_W_command {
3532 if (my ($arg) = $DB::cmd =~ /\AW\b\s*(.*)/s) {
3533 DB::cmd_W( 'W', $arg );
3534 next CMD;
3535 }
3536
3537 return;
3538}
3539
14f38b27
SF
3540sub _handle_rc_recall_command {
3541 my $self = shift;
3542
3543 # $rc - recall command.
3544 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) {
3545
3546 # No arguments, take one thing off history.
3547 pop(@hist) if length($DB::cmd) > 1;
3548
3549 # Relative (- found)?
3550 # Y - index back from most recent (by 1 if bare minus)
3551 # N - go to that particular command slot or the last
3552 # thing if nothing following.
3553 my $new_i = $minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist );
3554
3555 $self->i_cmd($new_i);
3556
3557 # Pick out the command desired.
3558 $DB::cmd = $hist[$self->i_cmd];
3559
3560 # Print the command to be executed and restart the loop
3561 # with that command in the buffer.
3562 print {$OUT} $DB::cmd, "\n";
3563 redo CMD;
3564 }
3565
3566 return;
3567}
3568
0d2c714c
SF
3569sub _handle_rc_search_history_command {
3570 my $self = shift;
3571
3572 # $rc pattern $rc - find a command in the history.
3573 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) {
3574
3575 # Create the pattern to use.
3576 my $pat = "^$arg";
3577 $self->pat($pat);
3578
3579 # Toss off last entry if length is >1 (and it always is).
3580 pop(@hist) if length($DB::cmd) > 1;
3581
3582 my $i = $self->i_cmd;
3583
3584 # Look backward through the history.
3585 SEARCH_HIST:
3586 for ( $i = $#hist ; $i ; --$i ) {
3587 # Stop if we find it.
3588 last SEARCH_HIST if $hist[$i] =~ /$pat/;
3589 }
3590
3591 $self->i_cmd($i);
3592
3593 if ( !$self->i_cmd ) {
3594
3595 # Never found it.
3596 print $OUT "No such command!\n\n";
3597 next CMD;
3598 }
3599
3600 # Found it. Put it in the buffer, print it, and process it.
3601 $DB::cmd = $hist[$self->i_cmd];
3602 print $OUT $DB::cmd, "\n";
3603 redo CMD;
3604 }
b6aeebb8
SF
3605
3606 return;
0d2c714c
SF
3607}
3608
0664c09a
SF
3609sub _handle_H_command {
3610 my $self = shift;
3611
3612 if ($DB::cmd =~ /\AH\b\s*\*/) {
3613 @hist = @truehist = ();
3614 print $OUT "History cleansed\n";
3615 next CMD;
3616 }
3617
3618 if (my ($num)
3619 = $DB::cmd =~ /\AH\b\s*(?:-(\d+))?/) {
3620
3621 # Anything other than negative numbers is ignored by
3622 # the (incorrect) pattern, so this test does nothing.
3623 $end = $num ? ( $#hist - $num ) : 0;
3624
3625 # Set to the minimum if less than zero.
3626 $hist = 0 if $hist < 0;
3627
3628 # Start at the end of the array.
3629 # Stay in while we're still above the ending value.
3630 # Tick back by one each time around the loop.
3631 my $i;
3632
3633 for ( $i = $#hist ; $i > $end ; $i-- ) {
3634
3635 # Print the command unless it has no arguments.
3636 print $OUT "$i: ", $hist[$i], "\n"
3637 unless $hist[$i] =~ /^.?$/;
3638 }
3639
3640 $self->i_cmd($i);
3641
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': $!\n");
3828 }
3829 next CMD;
3830 }
3831
3832 return;
3833}
3834
50a8a759 3835sub _n_or_s_and_arg_commands_generic {
553947ba 3836 my ($self, $letter, $new_val) = @_;
4f29ef90
SF
3837
3838 # s - single-step. Remember the last command was 's'.
553947ba
SF
3839 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) {
3840 $laststep = $letter;
4f29ef90
SF
3841 }
3842
3843 return;
3844}
3845
466f24c7 3846sub _handle_sh_command {
ddf4cf26
SF
3847 my $self = shift;
3848
3849 # $sh$sh - run a shell command (if it's all ASCII).
3850 # Can't run shell commands with Unicode in the debugger, hmm.
466f24c7
SF
3851 my $my_cmd = $DB::cmd;
3852 if ($my_cmd =~ m#\A$sh#gms) {
ddf4cf26 3853
466f24c7
SF
3854