1 2=head1 NAME 3 4perl5db.pl - the perl debugger 5 6=head1 SYNOPSIS 7 8 perl -d your_Perl_script 9 10=head1 DESCRIPTION 11 12C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when 13you invoke a script with S<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 17See L<perldebug> for an overview of how to use the debugger. 18 19=head1 GENERAL NOTES 20 21The debugger can look pretty forbidding to many Perl programmers. There are 22a number of reasons for this, many stemming out of the debugger's history. 23 24When the debugger was first written, Perl didn't have a lot of its nicer 25features - no references, no lexical variables, no closures, no object-oriented 26programming. So a lot of the things one would normally have done using such 27features was done using global variables, globs and the C<local()> operator 28in creative ways. 29 30Some of these have survived into the current debugger; a few of the more 31interesting and still-useful idioms are noted in this section, along with notes 32on the comments themselves. 33 34=head2 Why not use more lexicals? 35 36Experienced Perl programmers will note that the debugger code tends to use 37mostly package globals rather than lexically-scoped variables. This is done 38to allow a significant amount of control of the debugger from outside the 39debugger itself. 40 41Unfortunately, though the variables are accessible, they're not well 42documented, so it's generally been a decision that hasn't made a lot of 43difference to most users. Where appropriate, comments have been added to 44make variables more accessible and usable, with the understanding that these 45I<are> debugger internals, and are therefore subject to change. Future 46development should probably attempt to replace the globals with a well-defined 47API, but for now, the variables are what we've got. 48 49=head2 Automated variable stacking via C<local()> 50 51As you may recall from reading C<perlfunc>, the C<local()> operator makes a 52temporary copy of a variable in the current scope. When the scope ends, the 53old copy is restored. This is often used in the debugger to handle the 54automatic stacking of variables during recursive calls: 55 56 sub foo { 57 local $some_global++; 58 59 # Do some stuff, then ... 60 return; 61 } 62 63What happens is that on entry to the subroutine, C<$some_global> is localized, 64then altered. When the subroutine returns, Perl automatically undoes the 65localization, restoring the previous value. Voila, automatic stack management. 66 67The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>, 68which lets the debugger get control inside of C<eval>'ed code. The debugger 69localizes a saved copy of C<$@> inside the subroutine, which allows it to 70keep C<$@> safe until it C<DB::eval> returns, at which point the previous 71value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep 72track of C<$@> inside C<eval>s which C<eval> other C<eval's>. 73 74In any case, watch for this pattern. It occurs fairly often. 75 76=head2 The C<^> trick 77 78This is used to cleverly reverse the sense of a logical test depending on 79the value of an auxiliary variable. For instance, the debugger's C<S> 80(search for subroutines by pattern) allows you to negate the pattern 81like this: 82 83 # Find all non-'foo' subs: 84 S !/foo/ 85 86Boolean algebra states that the truth table for XOR looks like this: 87 88=over 4 89 90=item * 0 ^ 0 = 0 91 92(! not present and no match) --> false, don't print 93 94=item * 0 ^ 1 = 1 95 96(! not present and matches) --> true, print 97 98=item * 1 ^ 0 = 1 99 100(! present and no match) --> true, print 101 102=item * 1 ^ 1 = 0 103 104(! present and matches) --> false, don't print 105 106=back 107 108As you can see, the first pair applies when C<!> isn't supplied, and 109the second pair applies when it is. The XOR simply allows us to 110compact a more complicated if-then-elseif-else into a more elegant 111(but perhaps overly clever) single test. After all, it needed this 112explanation... 113 114=head2 FLAGS, FLAGS, FLAGS 115 116There is a certain C programming legacy in the debugger. Some variables, 117such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed 118of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces 119of state to be stored independently in a single scalar. 120 121A test like 122 123 if ($scalar & 4) ... 124 125is checking to see if the appropriate bit is on. Since each bit can be 126"addressed" independently in this way, C<$scalar> is acting sort of like 127an array of bits. Obviously, since the contents of C<$scalar> are just a 128bit-pattern, we can save and restore it easily (it will just look like 129a number). 130 131The problem, is of course, that this tends to leave magic numbers scattered 132all over your program whenever a bit is set, cleared, or checked. So why do 133it? 134 135=over 4 136 137=item * 138 139First, doing an arithmetical or bitwise operation on a scalar is 140just about the fastest thing you can do in Perl: S<C<use constant>> actually 141creates a subroutine call, and array and hash lookups are much slower. Is 142this over-optimization at the expense of readability? Possibly, but the 143debugger accesses these variables a I<lot>. Any rewrite of the code will 144probably have to benchmark alternate implementations and see which is the 145best balance of readability and speed, and then document how it actually 146works. 147 148=item * 149 150Second, it's very easy to serialize a scalar number. This is done in 151the restart code; the debugger state variables are saved in C<%ENV> and then 152restored when the debugger is restarted. Having them be just numbers makes 153this trivial. 154 155=item * 156 157Third, some of these variables are being shared with the Perl core 158smack in the middle of the interpreter's execution loop. It's much faster for 159a C program (like the interpreter) to check a bit in a scalar than to access 160several different variables (or a Perl array). 161 162=back 163 164=head2 What are those C<XXX> comments for? 165 166Any comment containing C<XXX> means that the comment is either somewhat 167speculative - it's not exactly clear what a given variable or chunk of 168code is doing, or that it is incomplete - the basics may be clear, but the 169subtleties are not completely documented. 170 171Send in a patch if you can clear up, fill out, or clarify an C<XXX>. 172 173=head1 DATA STRUCTURES MAINTAINED BY CORE 174 175There are a number of special data structures provided to the debugger by 176the Perl interpreter. 177 178The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> 179via glob assignment) contains the text from C<$filename>, with each 180element corresponding to a single line of C<$filename>. Additionally, 181breakable lines will be dualvars with the numeric component being the 182memory address of a COP node. Non-breakable lines are dualvar to 0. 183 184The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob 185assignment) contains breakpoints and actions. The keys are line numbers; 186you can set individual values, but not the whole hash. The Perl interpreter 187uses this hash to determine where breakpoints have been set. Any true value is 188considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>. 189Values are magical in numeric context: 1 if the line is breakable, 0 if not. 190 191The scalar C<${"_<$filename"}> simply contains the string C<$filename>. 192This is also the case for evaluated strings that contain subroutines, or 193which are currently being executed. The $filename for C<eval>ed strings looks 194like S<C<(eval 34)>>. 195 196=head1 DEBUGGER STARTUP 197 198When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for 199non-interactive sessions, C<.perldb> for interactive ones) that can set a number 200of options. In addition, this file may define a subroutine C<&afterinit> 201that will be executed (in the debugger's context) after the debugger has 202initialized itself. 203 204Next, it checks the C<PERLDB_OPTS> environment variable and treats its 205contents as the argument of a C<o> command in the debugger. 206 207=head2 STARTUP-ONLY OPTIONS 208 209The following options can only be specified at startup. 210To set them in your rcfile, add a call to 211C<&parse_options("optionName=new_value")>. 212 213=over 4 214 215=item * TTY 216 217the TTY to use for debugging i/o. 218 219=item * noTTY 220 221if set, goes in NonStop mode. On interrupt, if TTY is not set, 222uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using 223Term::Rendezvous. Current variant is to have the name of TTY in this 224file. 225 226=item * ReadLine 227 228if false, a dummy ReadLine is used, so you can debug 229ReadLine applications. 230 231=item * NonStop 232 233if true, no i/o is performed until interrupt. 234 235=item * LineInfo 236 237file or pipe to print line number info to. If it is a 238pipe, a short "emacs like" message is used. 239 240=item * RemotePort 241 242host:port to connect to on remote host for remote debugging. 243 244=item * HistFile 245 246file to store session history to. There is no default and so no 247history file is written unless this variable is explicitly set. 248 249=item * HistSize 250 251number of commands to store to the file specified in C<HistFile>. 252Default is 100. 253 254=back 255 256=head3 SAMPLE RCFILE 257 258 &parse_options("NonStop=1 LineInfo=db.out"); 259 sub afterinit { $trace = 1; } 260 261The script will run without human intervention, putting trace 262information into C<db.out>. (If you interrupt it, you had better 263reset C<LineInfo> to something I<interactive>!) 264 265=head1 INTERNALS DESCRIPTION 266 267=head2 DEBUGGER INTERFACE VARIABLES 268 269Perl supplies the values for C<%sub>. It effectively inserts 270a C<&DB::DB();> in front of each place that can have a 271breakpoint. At each subroutine call, it calls C<&DB::sub> with 272C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN 273{require 'perl5db.pl'}> before the first line. 274 275After each C<require>d file is compiled, but before it is executed, a 276call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename> 277is the expanded name of the C<require>d file (as found via C<%INC>). 278 279=head3 IMPORTANT INTERNAL VARIABLES 280 281=head4 C<$CreateTTY> 282 283Used to control when the debugger will attempt to acquire another TTY to be 284used for input. 285 286=over 287 288=item * 1 - on C<fork()> 289 290=item * 2 - debugger is started inside debugger 291 292=item * 4 - on startup 293 294=back 295 296=head4 C<$doret> 297 298The value -2 indicates that no return value should be printed. 299Any other positive value causes C<DB::sub> to print return values. 300 301=head4 C<$evalarg> 302 303The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current 304contents of C<@_> when C<DB::eval> is called. 305 306=head4 C<$frame> 307 308Determines what messages (if any) will get printed when a subroutine (or eval) 309is entered or exited. 310 311=over 4 312 313=item * 0 - No enter/exit messages 314 315=item * 1 - Print I<entering> messages on subroutine entry 316 317=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2. 318 319=item * 4 - Extended messages: C<< <in|out> I<context>=I<fully-qualified sub name> from I<file>:I<line> >>. If no other flag is on, acts like 1+4. 320 321=item * 8 - Adds parameter information to messages, and overloaded stringify and tied FETCH is enabled on the printed arguments. Ignored if C<4> is not on. 322 323=item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is not on. 324 325=back 326 327To get everything, use C<$frame=30> (or S<C<o f=30>> as a debugger command). 328The debugger internally juggles the value of C<$frame> during execution to 329protect external modules that the debugger uses from getting traced. 330 331=head4 C<$level> 332 333Tracks current debugger nesting level. Used to figure out how many 334C<E<lt>E<gt>> pairs to surround the line number with when the debugger 335outputs a prompt. Also used to help determine if the program has finished 336during command parsing. 337 338=head4 C<$onetimeDump> 339 340Controls what (if anything) C<DB::eval()> will print after evaluating an 341expression. 342 343=over 4 344 345=item * C<undef> - don't print anything 346 347=item * C<dump> - use C<dumpvar.pl> to display the value returned 348 349=item * C<methods> - print the methods callable on the first item returned 350 351=back 352 353=head4 C<$onetimeDumpDepth> 354 355Controls how far down C<dumpvar.pl> will go before printing C<...> while 356dumping a structure. Numeric. If C<undef>, print all levels. 357 358=head4 C<$signal> 359 360Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>, 361which is called before every statement, checks this and puts the user into 362command mode if it finds C<$signal> set to a true value. 363 364=head4 C<$single> 365 366Controls behavior during single-stepping. Stacked in C<@stack> on entry to 367each subroutine; popped again at the end of each subroutine. 368 369=over 4 370 371=item * 0 - run continuously. 372 373=item * 1 - single-step, go into subs. The C<s> command. 374 375=item * 2 - single-step, don't go into subs. The C<n> command. 376 377=item * 4 - print current sub depth (turned on to force this when C<too much 378recursion> occurs. 379 380=back 381 382=head4 C<$trace> 383 384Controls the output of trace information. 385 386=over 4 387 388=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed) 389 390=item * 2 - watch expressions are active 391 392=item * 4 - user defined a C<watchfunction()> in C<afterinit()> 393 394=back 395 396=head4 C<$client_editor> 397 3981 if C<LINEINFO> was directed to a pipe; 0 otherwise. (The term 399C<$slave_editor> was formerly used here.) 400 401=head4 C<@cmdfhs> 402 403Stack of filehandles that C<DB::readline()> will read commands from. 404Manipulated by the debugger's C<source> command and C<DB::readline()> itself. 405 406=head4 C<@dbline> 407 408Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> , 409supplied by the Perl interpreter to the debugger. Contains the source. 410 411=head4 C<@old_watch> 412 413Previous values of watch expressions. First set when the expression is 414entered; reset whenever the watch expression changes. 415 416=head4 C<@saved> 417 418Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>) 419so that the debugger can substitute safe values while it's running, and 420restore them when it returns control. 421 422=head4 C<@stack> 423 424Saves the current value of C<$single> on entry to a subroutine. 425Manipulated by the C<c> command to turn off tracing in all subs above the 426current one. 427 428=head4 C<@to_watch> 429 430The 'watch' expressions: to be evaluated before each line is executed. 431 432=head4 C<@typeahead> 433 434The typeahead buffer, used by C<DB::readline>. 435 436=head4 C<%alias> 437 438Command aliases. Stored as character strings to be substituted for a command 439entered. 440 441=head4 C<%break_on_load> 442 443Keys are file names, values are 1 (break when this file is loaded) or undef 444(don't break when it is loaded). 445 446=head4 C<%dbline> 447 448Keys are line numbers, values are C<condition\0action>. If used in numeric 449context, values are 0 if not breakable, 1 if breakable, no matter what is 450in the actual hash entry. 451 452=head4 C<%had_breakpoints> 453 454Keys are file names; values are bitfields: 455 456=over 4 457 458=item * 1 - file has a breakpoint in it. 459 460=item * 2 - file has an action in it. 461 462=back 463 464A zero or undefined value means this file has neither. 465 466=head4 C<%option> 467 468Stores the debugger options. These are character string values. 469 470=head4 C<%postponed> 471 472Saves breakpoints for code that hasn't been compiled yet. 473Keys are subroutine names, values are: 474 475=over 4 476 477=item * C<compile> - break when this sub is compiled 478 479=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified. 480 481=back 482 483=head4 C<%postponed_file> 484 485This hash keeps track of breakpoints that need to be set for files that have 486not yet been compiled. Keys are filenames; values are references to hashes. 487Each of these hashes is keyed by line number, and its values are breakpoint 488definitions (C<condition\0action>). 489 490=head1 DEBUGGER INITIALIZATION 491 492The debugger's initialization actually jumps all over the place inside this 493package. This is because there are several BEGIN blocks (which of course 494execute immediately) spread through the code. Why is that? 495 496The debugger needs to be able to change some things and set some things up 497before the debugger code is compiled; most notably, the C<$deep> variable that 498C<DB::sub> uses to tell when a program has recursed deeply. In addition, the 499debugger has to turn off warnings while the debugger code is compiled, but then 500restore them to their original setting before the program being debugged begins 501executing. 502 503The first C<BEGIN> block simply turns off warnings by saving the current 504setting of C<$^W> and then setting it to zero. The second one initializes 505the debugger variables that are needed before the debugger begins executing. 506The third one puts C<$^X> back to its former value. 507 508We'll detail the second C<BEGIN> block later; just remember that if you need 509to initialize something before the debugger starts really executing, that's 510where it has to go. 511 512=cut 513 514package DB; 515 516use strict; 517 518use Cwd (); 519 520my $_initial_cwd; 521 522BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl 523 524BEGIN { 525 require feature; 526 $^V =~ /^v(\d+\.\d+)/; 527 feature->import(":$1"); 528 $_initial_cwd = Cwd::getcwd(); 529} 530 531# Debugger for Perl 5.00x; perl5db.pl patch level: 532use vars qw($VERSION $header); 533 534# bump to X.XX in blead, only use X.XX_XX in maint 535$VERSION = '1.77'; 536 537$header = "perl5db.pl version $VERSION"; 538 539=head1 DEBUGGER ROUTINES 540 541=head2 C<DB::eval()> 542 543This function replaces straight C<eval()> inside the debugger; it simplifies 544the process of evaluating code in the user's context. 545 546The code to be evaluated is passed via the package global variable 547C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>. 548 549Before we do the C<eval()>, we preserve the current settings of C<$trace>, 550C<$single>, C<$^D> and C<$usercontext>. The latter contains the 551preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the 552user's current package, grabbed when C<DB::DB> got control. This causes the 553proper context to be used when the eval is actually done. Afterward, we 554restore C<$trace>, C<$single>, and C<$^D>. 555 556Next we need to handle C<$@> without getting confused. We save C<$@> in a 557local lexical, localize C<$saved[0]> (which is where C<save()> will put 558C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>, 559C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values 560considered sane by the debugger. If there was an C<eval()> error, we print 561it on the debugger's output. If C<$onetimedump> is defined, we call 562C<dumpit> if it's set to 'dump', or C<methods> if it's set to 563'methods'. Setting it to something else causes the debugger to do the eval 564but not print the result - handy if you want to do something else with it 565(the "watch expressions" code does this to get the value of the watch 566expression but not show it unless it matters). 567 568In any case, we then return the list of output from C<eval> to the caller, 569and unwinding restores the former version of C<$@> in C<@saved> as well 570(the localization of C<$saved[0]> goes away at the end of this scope). 571 572=head3 Parameters and variables influencing execution of DB::eval() 573 574C<DB::eval> isn't parameterized in the standard way; this is to keep the 575debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things. 576The variables listed below influence C<DB::eval()>'s execution directly. 577 578=over 4 579 580=item C<$evalarg> - the thing to actually be eval'ed 581 582=item C<$trace> - Current state of execution tracing 583 584=item C<$single> - Current state of single-stepping 585 586=item C<$onetimeDump> - what is to be displayed after the evaluation 587 588=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results 589 590=back 591 592The following variables are altered by C<DB::eval()> during its execution. They 593are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>. 594 595=over 4 596 597=item C<@res> - used to capture output from actual C<eval>. 598 599=item C<$otrace> - saved value of C<$trace>. 600 601=item C<$osingle> - saved value of C<$single>. 602 603=item C<$od> - saved value of C<$^D>. 604 605=item C<$saved[0]> - saved value of C<$@>. 606 607=item $\ - for output of C<$@> if there is an evaluation error. 608 609=back 610 611=head3 The problem of lexicals 612 613The context of C<DB::eval()> presents us with some problems. Obviously, 614we want to be 'sandboxed' away from the debugger's internals when we do 615the eval, but we need some way to control how punctuation variables and 616debugger globals are used. 617 618We can't use local, because the code inside C<DB::eval> can see localized 619variables; and we can't use C<my> either for the same reason. The code 620in this routine compromises and uses C<my>. 621 622After this routine is over, we don't have user code executing in the debugger's 623context, so we can use C<my> freely. 624 625=cut 626 627############################################## Begin lexical danger zone 628 629# 'my' variables used here could leak into (that is, be visible in) 630# the context that the code being evaluated is executing in. This means that 631# the code could modify the debugger's variables. 632# 633# Fiddling with the debugger's context could be Bad. We insulate things as 634# much as we can. 635 636use vars qw( 637 @args 638 %break_on_load 639 $CommandSet 640 $CreateTTY 641 $DBGR 642 @dbline 643 $dbline 644 %dbline 645 $dieLevel 646 $filename 647 $histfile 648 $histsize 649 $histitemminlength 650 $IN 651 $inhibit_exit 652 @ini_INC 653 $ini_warn 654 $maxtrace 655 $od 656 @options 657 $osingle 658 $otrace 659 $pager 660 $post 661 %postponed 662 $prc 663 $pre 664 $pretype 665 $psh 666 @RememberOnROptions 667 $remoteport 668 @res 669 $rl 670 @saved 671 $signalLevel 672 $sub 673 $term 674 $usercontext 675 $warnLevel 676); 677 678our ( 679 @cmdfhs, 680 $evalarg, 681 $frame, 682 $hist, 683 $ImmediateStop, 684 $line, 685 $onetimeDump, 686 $onetimedumpDepth, 687 %option, 688 $OUT, 689 $packname, 690 $signal, 691 $single, 692 $start, 693 %sub, 694 $subname, 695 $trace, 696 $window, 697); 698 699# Used to save @ARGV and extract any debugger-related flags. 700use vars qw(@ARGS); 701 702# Used to prevent multiple entries to diesignal() 703# (if for instance diesignal() itself dies) 704use vars qw($panic); 705 706# Used to prevent the debugger from running nonstop 707# after a restart 708our ($second_time); 709 710sub _calc_usercontext { 711 my ($package) = @_; 712 713 # Cancel strict completely for the evaluated code, so the code 714 # the user evaluates won't be affected by it. (Shlomi Fish) 715 return 'no strict; ($@, $!, $^E, $,, $/, $\, $^W) = @DB::saved;' 716 . "package $package;"; # this won't let them modify, alas 717} 718 719sub eval { 720 721 # 'my' would make it visible from user code 722 # but so does local! --tchrist 723 # Remember: this localizes @DB::res, not @main::res. 724 local @res; 725 { 726 727 # Try to keep the user code from messing with us. Save these so that 728 # even if the eval'ed code changes them, we can put them back again. 729 # Needed because the user could refer directly to the debugger's 730 # package globals (and any 'my' variables in this containing scope) 731 # inside the eval(), and we want to try to stay safe. 732 local $otrace = $trace; 733 local $osingle = $single; 734 local $od = $^D; 735 736 # Untaint the incoming eval() argument. 737 { ($evalarg) = $evalarg =~ /(.*)/s; } 738 739 # $usercontext built in DB::DB near the comment 740 # "set up the context for DB::eval ..." 741 # Evaluate and save any results. 742 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug 743 744 # Restore those old values. 745 $trace = $otrace; 746 $single = $osingle; 747 $^D = $od; 748 } 749 750 # Save the current value of $@, and preserve it in the debugger's copy 751 # of the saved precious globals. 752 my $at = $@; 753 754 # Since we're only saving $@, we only have to localize the array element 755 # that it will be stored in. 756 local $saved[0]; # Preserve the old value of $@ 757 eval { &DB::save }; 758 759 # Now see whether we need to report an error back to the user. 760 if ($at) { 761 local $\ = ''; 762 print $OUT $at; 763 } 764 765 # Display as required by the caller. $onetimeDump and $onetimedumpDepth 766 # are package globals. 767 elsif ($onetimeDump) { 768 if ( $onetimeDump eq 'dump' ) { 769 local $option{dumpDepth} = $onetimedumpDepth 770 if defined $onetimedumpDepth; 771 dumpit( $OUT, \@res ); 772 } 773 elsif ( $onetimeDump eq 'methods' ) { 774 methods( $res[0] ); 775 } 776 } ## end elsif ($onetimeDump) 777 @res; 778} ## end sub eval 779 780############################################## End lexical danger zone 781 782# After this point it is safe to introduce lexicals. 783# The code being debugged will be executing in its own context, and 784# can't see the inside of the debugger. 785# 786# However, one should not overdo it: leave as much control from outside as 787# possible. If you make something a lexical, it's not going to be addressable 788# from outside the debugger even if you know its name. 789 790# This file is automatically included if you do perl -d. 791# It's probably not useful to include this yourself. 792# 793# Before venturing further into these twisty passages, it is 794# wise to read the perldebguts man page or risk the ire of dragons. 795# 796# (It should be noted that perldebguts will tell you a lot about 797# the underlying mechanics of how the debugger interfaces into the 798# Perl interpreter, but not a lot about the debugger itself. The new 799# comments in this code try to address this problem.) 800 801# Note that no subroutine call is possible until &DB::sub is defined 802# (for subroutines defined outside of the package DB). In fact the same is 803# true if $deep is not defined. 804 805# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich) 806 807# modified Perl debugger, to be run from Emacs in perldb-mode 808# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990 809# Johan Vromans -- upgrade to 4.0 pl 10 810# Ilya Zakharevich -- patches after 5.001 (and some before ;-) 811######################################################################## 812 813=head1 DEBUGGER INITIALIZATION 814 815The debugger starts up in phases. 816 817=head2 BASIC SETUP 818 819First, it initializes the environment it wants to run in: turning off 820warnings during its own compilation, defining variables which it will need 821to avoid warnings later, setting itself up to not exit when the program 822terminates, and defaulting to printing return values for the C<r> command. 823 824=cut 825 826# Needed for the statement after exec(): 827# 828# This BEGIN block is simply used to switch off warnings during debugger 829# compilation. Probably it would be better practice to fix the warnings, 830# but this is how it's done at the moment. 831 832BEGIN { 833 $ini_warn = $^W; 834 $^W = 0; 835} # Switch compilation warnings off until another BEGIN. 836 837local ($^W) = 0; # Switch run-time warnings off during init. 838 839=head2 THREADS SUPPORT 840 841If we are running under a threaded Perl, we require threads and threads::shared 842if the environment variable C<PERL5DB_THREADED> is set, to enable proper 843threaded debugger control. C<-dt> can also be used to set this. 844 845Each new thread will be announced and the debugger prompt will always inform 846you of each new thread created. It will also indicate the thread id in which 847we are currently running within the prompt like this: 848 849 [tid] DB<$i> 850 851Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger 852command prompt. The prompt will show: C<[0]> when running under threads, but 853not actually in a thread. C<[tid]> is consistent with C<gdb> usage. 854 855While running under threads, when you set or delete a breakpoint (etc.), this 856will apply to all threads, not just the currently running one. When you are 857in a currently executing thread, you will stay there until it completes. With 858the current implementation it is not currently possible to hop from one thread 859to another. 860 861The C<e> and C<E> commands are currently fairly minimal - see 862S<C<h e>> and S<C<h E>>. 863 864Note that threading support was built into the debugger as of Perl version 865C<5.8.6> and debugger version C<1.2.8>. 866 867=cut 868 869BEGIN { 870 # ensure we can share our non-threaded variables or no-op 871 if ($ENV{PERL5DB_THREADED}) { 872 require threads; 873 require threads::shared; 874 import threads::shared qw(share); 875 $DBGR; 876 share(\$DBGR); 877 lock($DBGR); 878 print "Threads support enabled\n"; 879 } else { 880 *lock = sub :prototype(*) {}; 881 *share = sub :prototype(\[$@%]) {}; 882 } 883} 884 885# These variables control the execution of 'dumpvar.pl'. 886{ 887 package dumpvar; 888 use vars qw( 889 $hashDepth 890 $arrayDepth 891 $dumpDBFiles 892 $dumpPackages 893 $quoteHighBit 894 $printUndef 895 $globPrint 896 $usageOnly 897 ); 898} 899 900# used to control die() reporting in diesignal() 901{ 902 package Carp; 903 use vars qw($CarpLevel); 904} 905 906# without threads, $filename is not defined until DB::DB is called 907share($main::{'_<'.$filename}) if defined $filename; 908 909# Command-line + PERLLIB: 910# Save the contents of @INC before they are modified elsewhere. 911@ini_INC = @INC; 912 913# This was an attempt to clear out the previous values of various 914# trapped errors. Apparently it didn't help. XXX More info needed! 915# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?! 916 917# We set these variables to safe values. We don't want to blindly turn 918# off warnings, because other packages may still want them. 919$trace = $signal = $single = 0; # Uninitialized warning suppression 920 # (local $^W cannot help - other packages!). 921 922# Default to not exiting when program finishes; print the return 923# value when the 'r' command is used to return from a subroutine. 924$inhibit_exit = $option{PrintRet} = 1; 925 926use vars qw($trace_to_depth); 927 928# Default to 1E9 so it won't be limited to a certain recursion depth. 929$trace_to_depth = 1E9; 930 931=head1 OPTION PROCESSING 932 933The debugger's options are actually spread out over the debugger itself and 934C<dumpvar.pl>; some of these are variables to be set, while others are 935subs to be called with a value. To try to make this a little easier to 936manage, the debugger uses a few data structures to define what options 937are legal and how they are to be processed. 938 939First, the C<@options> array defines the I<names> of all the options that 940are to be accepted. 941 942=cut 943 944@options = qw( 945 CommandSet HistFile HistSize 946 HistItemMinLength 947 hashDepth arrayDepth dumpDepth 948 DumpDBFiles DumpPackages DumpReused 949 compactDump veryCompact quote 950 HighBit undefPrint globPrint 951 PrintRet UsageOnly frame 952 AutoTrace TTY noTTY 953 ReadLine NonStop LineInfo 954 maxTraceLen recallCommand ShellBang 955 pager tkRunning ornaments 956 signalLevel warnLevel dieLevel 957 inhibit_exit ImmediateStop bareStringify 958 CreateTTY RemotePort windowSize 959 DollarCaretP 960); 961 962@RememberOnROptions = qw(DollarCaretP); 963 964=pod 965 966Second, C<optionVars> lists the variables that each option uses to save its 967state. 968 969=cut 970 971use vars qw(%optionVars); 972 973%optionVars = ( 974 hashDepth => \$dumpvar::hashDepth, 975 arrayDepth => \$dumpvar::arrayDepth, 976 CommandSet => \$CommandSet, 977 DumpDBFiles => \$dumpvar::dumpDBFiles, 978 DumpPackages => \$dumpvar::dumpPackages, 979 DumpReused => \$dumpvar::dumpReused, 980 HighBit => \$dumpvar::quoteHighBit, 981 undefPrint => \$dumpvar::printUndef, 982 globPrint => \$dumpvar::globPrint, 983 UsageOnly => \$dumpvar::usageOnly, 984 CreateTTY => \$CreateTTY, 985 bareStringify => \$dumpvar::bareStringify, 986 frame => \$frame, 987 AutoTrace => \$trace, 988 inhibit_exit => \$inhibit_exit, 989 maxTraceLen => \$maxtrace, 990 ImmediateStop => \$ImmediateStop, 991 RemotePort => \$remoteport, 992 windowSize => \$window, 993 HistFile => \$histfile, 994 HistSize => \$histsize, 995 HistItemMinLength => \$histitemminlength 996); 997 998=pod 999 1000Third, C<%optionAction> defines the subroutine to be called to process each 1001option. 1002 1003=cut 1004 1005use vars qw(%optionAction); 1006 1007%optionAction = ( 1008 compactDump => \&dumpvar::compactDump, 1009 veryCompact => \&dumpvar::veryCompact, 1010 quote => \&dumpvar::quote, 1011 TTY => \&TTY, 1012 noTTY => \&noTTY, 1013 ReadLine => \&ReadLine, 1014 NonStop => \&NonStop, 1015 LineInfo => \&LineInfo, 1016 recallCommand => \&recallCommand, 1017 ShellBang => \&shellBang, 1018 pager => \&pager, 1019 signalLevel => \&signalLevel, 1020 warnLevel => \&warnLevel, 1021 dieLevel => \&dieLevel, 1022 tkRunning => \&tkRunning, 1023 ornaments => \&ornaments, 1024 RemotePort => \&RemotePort, 1025 DollarCaretP => \&DollarCaretP, 1026); 1027 1028=pod 1029 1030Last, the C<%optionRequire> notes modules that must be C<require>d if an 1031option is used. 1032 1033=cut 1034 1035# Note that this list is not complete: several options not listed here 1036# actually require that dumpvar.pl be loaded for them to work, but are 1037# not in the table. A subsequent patch will correct this problem; for 1038# the moment, we're just recommenting, and we are NOT going to change 1039# function. 1040use vars qw(%optionRequire); 1041 1042%optionRequire = ( 1043 compactDump => 'dumpvar.pl', 1044 veryCompact => 'dumpvar.pl', 1045 quote => 'dumpvar.pl', 1046); 1047 1048=pod 1049 1050There are a number of initialization-related variables which can be set 1051by putting code to set them in a BEGIN block in the C<PERL5DB> environment 1052variable. These are: 1053 1054=over 4 1055 1056=item C<$rl> - readline control XXX needs more explanation 1057 1058=item C<$warnLevel> - whether or not debugger takes over warning handling 1059 1060=item C<$dieLevel> - whether or not debugger takes over die handling 1061 1062=item C<$signalLevel> - whether or not debugger takes over signal handling 1063 1064=item C<$pre> - preprompt actions (array reference) 1065 1066=item C<$post> - postprompt actions (array reference) 1067 1068=item C<$pretype> 1069 1070=item C<$CreateTTY> - whether or not to create a new TTY for this debugger 1071 1072=item C<$CommandSet> - which command set to use (defaults to new, documented set) 1073 1074=back 1075 1076=cut 1077 1078# These guys may be defined in $ENV{PERL5DB} : 1079$rl = 1 unless defined $rl; 1080$warnLevel = 1 unless defined $warnLevel; 1081$dieLevel = 1 unless defined $dieLevel; 1082$signalLevel = 1 unless defined $signalLevel; 1083$pre = [] unless defined $pre; 1084$post = [] unless defined $post; 1085$pretype = [] unless defined $pretype; 1086$CreateTTY = 3 unless defined $CreateTTY; 1087$CommandSet = '580' unless defined $CommandSet; 1088 1089share($rl); 1090share($warnLevel); 1091share($dieLevel); 1092share($signalLevel); 1093share($pre); 1094share($post); 1095share($pretype); 1096share($CreateTTY); 1097share($CommandSet); 1098 1099=pod 1100 1101The default C<die>, C<warn>, and C<signal> handlers are set up. 1102 1103=cut 1104 1105warnLevel($warnLevel); 1106dieLevel($dieLevel); 1107signalLevel($signalLevel); 1108 1109=pod 1110 1111The pager to be used is needed next. We try to get it from the 1112environment first. If it's not defined there, we try to find it in 1113the Perl C<Config.pm>. If it's not there, we default to C<more>. We 1114then call the C<pager()> function to save the pager name. 1115 1116=cut 1117 1118# This routine makes sure $pager is set up so that '|' can use it. 1119pager( 1120 1121 # If PAGER is defined in the environment, use it. 1122 defined $ENV{PAGER} 1123 ? $ENV{PAGER} 1124 1125 # If not, see if Config.pm defines it. 1126 : eval { require Config } 1127 && defined $Config::Config{pager} 1128 ? $Config::Config{pager} 1129 1130 # If not, fall back to 'more'. 1131 : 'more' 1132 ) 1133 unless defined $pager; 1134 1135=pod 1136 1137We set up the command to be used to access the man pages, the command 1138recall character (C<!> unless otherwise defined) and the shell escape 1139character (C<!> unless otherwise defined). Yes, these do conflict, and 1140neither works in the debugger at the moment. 1141 1142=cut 1143 1144setman(); 1145 1146# Set up defaults for command recall and shell escape (note: 1147# these currently don't work in linemode debugging). 1148recallCommand("!") unless defined $prc; 1149shellBang("!") unless defined $psh; 1150 1151=pod 1152 1153We then set up the gigantic string containing the debugger help. 1154We also set the limit on the number of arguments we'll display during a 1155trace. 1156 1157=cut 1158 1159sethelp(); 1160 1161# If we didn't get a default for the length of eval/stack trace args, 1162# set it here. 1163$maxtrace = 400 unless defined $maxtrace; 1164 1165=head2 SETTING UP THE DEBUGGER GREETING 1166 1167The debugger I<greeting> helps to inform the user how many debuggers are 1168running, and whether the current debugger is the primary or a child. 1169 1170If we are the primary, we just hang onto our pid so we'll have it when 1171or if we start a child debugger. If we are a child, we'll set things up 1172so we'll have a unique greeting and so the parent will give us our own 1173TTY later. 1174 1175We save the current contents of the C<PERLDB_PIDS> environment variable 1176because we mess around with it. We'll also need to hang onto it because 1177we'll need it if we restart. 1178 1179Child debuggers make a label out of the current PID structure recorded in 1180PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY 1181yet so the parent will give them one later via C<resetterm()>. 1182 1183=cut 1184 1185# Save the current contents of the environment; we're about to 1186# much with it. We'll need this if we have to restart. 1187use vars qw($ini_pids); 1188$ini_pids = $ENV{PERLDB_PIDS}; 1189 1190use vars qw ($pids $term_pid); 1191 1192if ( defined $ENV{PERLDB_PIDS} ) { 1193 1194 # We're a child. Make us a label out of the current PID structure 1195 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having 1196 # a term yet so the parent will give us one later via resetterm(). 1197 1198 my $env_pids = $ENV{PERLDB_PIDS}; 1199 $pids = "[$env_pids]"; 1200 1201 # Unless we are on OpenVMS, all programs under the DCL shell run under 1202 # the same PID. 1203 1204 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) { 1205 $term_pid = $$; 1206 } 1207 else { 1208 $ENV{PERLDB_PIDS} .= "->$$"; 1209 $term_pid = -1; 1210 } 1211 1212} ## end if (defined $ENV{PERLDB_PIDS... 1213else { 1214 1215 # We're the parent PID. Initialize PERLDB_PID in case we end up with a 1216 # child debugger, and mark us as the parent, so we'll know to set up 1217 # more TTY's is we have to. 1218 $ENV{PERLDB_PIDS} = "$$"; 1219 $pids = "[pid=$$]"; 1220 $term_pid = $$; 1221} 1222 1223use vars qw($pidprompt); 1224$pidprompt = ''; 1225 1226# Sets up $emacs as a synonym for $client_editor. 1227our ($client_editor); 1228*emacs = $client_editor if $client_editor; # May be used in afterinit()... 1229 1230=head2 READING THE RC FILE 1231 1232The debugger will read a file of initialization options if supplied. If 1233running interactively, this is C<.perldb>; if not, it's C<perldb.ini>. 1234 1235=cut 1236 1237# As noted, this test really doesn't check accurately that the debugger 1238# is running at a terminal or not. 1239 1240use vars qw($rcfile); 1241{ 1242 my $dev_tty = (($^O eq 'VMS') ? 'TT:' : '/dev/tty'); 1243 # this is the wrong metric! 1244 $rcfile = ((-e $dev_tty) ? ".perldb" : "perldb.ini"); 1245} 1246 1247=pod 1248 1249The debugger does a safety test of the file to be read. It must be owned 1250either by the current user or root, and must only be writable by the owner. 1251 1252=cut 1253 1254# This wraps a safety test around "do" to read and evaluate the init file. 1255# 1256# This isn't really safe, because there's a race 1257# between checking and opening. The solution is to 1258# open and fstat the handle, but then you have to read and 1259# eval the contents. But then the silly thing gets 1260# your lexical scope, which is unfortunate at best. 1261sub safe_do { 1262 my $file = shift; 1263 1264 # Just exactly what part of the word "CORE::" don't you understand? 1265 local $SIG{__WARN__}; 1266 local $SIG{__DIE__}; 1267 1268 unless ( is_safe_file($file) ) { 1269 CORE::warn <<EO_GRIPE; 1270perldb: Must not source insecure rcfile $file. 1271 You or the superuser must be the owner, and it must not 1272 be writable by anyone but its owner. 1273EO_GRIPE 1274 return; 1275 } ## end unless (is_safe_file($file... 1276 1277 do $file; 1278 CORE::warn("perldb: couldn't parse $file: $@") if $@; 1279} ## end sub safe_do 1280 1281# This is the safety test itself. 1282# 1283# Verifies that owner is either real user or superuser and that no 1284# one but owner may write to it. This function is of limited use 1285# when called on a path instead of upon a handle, because there are 1286# no guarantees that filename (by dirent) whose file (by ino) is 1287# eventually accessed is the same as the one tested. 1288# Assumes that the file's existence is not in doubt. 1289sub is_safe_file { 1290 my $path = shift; 1291 stat($path) || return; # mysteriously vaporized 1292 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_); 1293 1294 return 0 if $uid != 0 && $uid != $<; 1295 return 0 if $mode & 022; 1296 return 1; 1297} ## end sub is_safe_file 1298 1299# If the rcfile (whichever one we decided was the right one to read) 1300# exists, we safely do it. 1301if ( -f $rcfile ) { 1302 safe_do("./$rcfile"); 1303} 1304 1305# If there isn't one here, try the user's home directory. 1306elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) { 1307 safe_do("$ENV{HOME}/$rcfile"); 1308} 1309 1310# Else try the login directory. 1311elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) { 1312 safe_do("$ENV{LOGDIR}/$rcfile"); 1313} 1314 1315# If the PERLDB_OPTS variable has options in it, parse those out next. 1316if ( defined $ENV{PERLDB_OPTS} ) { 1317 parse_options( $ENV{PERLDB_OPTS} ); 1318} 1319 1320=pod 1321 1322The last thing we do during initialization is determine which subroutine is 1323to be used to obtain a new terminal when a new debugger is started. Right now, 1324the debugger only handles TCP sockets, X11, OS/2, amd Mac OS X 1325(darwin). 1326 1327=cut 1328 1329# Set up the get_fork_TTY subroutine to be aliased to the proper routine. 1330# Works if you're running an xterm or xterm-like window, or you're on 1331# OS/2, or on Mac OS X. This may need some expansion. 1332 1333if (not defined &get_fork_TTY) # only if no routine exists 1334{ 1335 if ( defined $remoteport ) { 1336 # Expect an inetd-like server 1337 *get_fork_TTY = \&socket_get_fork_TTY; # to listen to us 1338 } 1339 elsif (defined $ENV{TERM} # If we know what kind 1340 # of terminal this is, 1341 and $ENV{TERM} eq 'xterm' # and it's an xterm, 1342 and defined $ENV{DISPLAY} # and what display it's on, 1343 ) 1344 { 1345 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version 1346 } 1347 elsif ( $ENV{TMUX} ) { 1348 *get_fork_TTY = \&tmux_get_fork_TTY; 1349 } 1350 elsif ( $^O eq 'os2' ) { # If this is OS/2, 1351 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version 1352 } 1353 elsif ( $^O eq 'darwin' # If this is Mac OS X 1354 and defined $ENV{TERM_PROGRAM} # and we're running inside 1355 and $ENV{TERM_PROGRAM} 1356 eq 'Apple_Terminal' # Terminal.app 1357 ) 1358 { 1359 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version 1360 } 1361} ## end if (not defined &get_fork_TTY... 1362 1363# untaint $^O, which may have been tainted by the last statement. 1364# see bug [perl #24674] 1365$^O =~ m/^(.*)\z/; 1366$^O = $1; 1367 1368# Here begin the unreadable code. It needs fixing. 1369 1370=head2 RESTART PROCESSING 1371 1372This section handles the restart command. When the C<R> command is invoked, it 1373tries to capture all of the state it can into environment variables, and 1374then sets C<PERLDB_RESTART>. When we start executing again, we check to see 1375if C<PERLDB_RESTART> is there; if so, we reload all the information that 1376the R command stuffed into the environment variables. 1377 1378 PERLDB_RESTART - flag only, contains no restart data itself. 1379 PERLDB_HIST - command history, if it's available 1380 PERLDB_ON_LOAD - breakpoints set by the rc file 1381 PERLDB_POSTPONE - subs that have been loaded/not executed, 1382 and have actions 1383 PERLDB_VISITED - files that had breakpoints 1384 PERLDB_FILE_... - breakpoints for a file 1385 PERLDB_OPT - active options 1386 PERLDB_INC - the original @INC 1387 PERLDB_PRETYPE - preprompt debugger actions 1388 PERLDB_PRE - preprompt Perl code 1389 PERLDB_POST - post-prompt Perl code 1390 PERLDB_TYPEAHEAD - typeahead captured by readline() 1391 1392We chug through all these variables and plug the values saved in them 1393back into the appropriate spots in the debugger. 1394 1395=cut 1396 1397use vars qw(%postponed_file @typeahead); 1398 1399our (@hist, @truehist); 1400 1401sub _restore_shared_globals_after_restart 1402{ 1403 @hist = get_list('PERLDB_HIST'); 1404 %break_on_load = get_list("PERLDB_ON_LOAD"); 1405 %postponed = get_list("PERLDB_POSTPONE"); 1406 1407 share(@hist); 1408 share(@truehist); 1409 share(%break_on_load); 1410 share(%postponed); 1411} 1412 1413sub _restore_breakpoints_and_actions { 1414 1415 my @had_breakpoints = get_list("PERLDB_VISITED"); 1416 1417 for my $file_idx ( 0 .. $#had_breakpoints ) { 1418 my $filename = $had_breakpoints[$file_idx]; 1419 my %pf = get_list("PERLDB_FILE_$file_idx"); 1420 $postponed_file{ $filename } = \%pf if %pf; 1421 my @lines = sort {$a <=> $b} keys(%pf); 1422 my @enabled_statuses = get_list("PERLDB_FILE_ENABLED_$file_idx"); 1423 for my $line_idx (0 .. $#lines) { 1424 _set_breakpoint_enabled_status( 1425 $filename, 1426 $lines[$line_idx], 1427 ($enabled_statuses[$line_idx] ? 1 : ''), 1428 ); 1429 } 1430 } 1431 1432 return; 1433} 1434 1435sub _restore_options_after_restart 1436{ 1437 my %options_map = get_list("PERLDB_OPT"); 1438 1439 while ( my ( $opt, $val ) = each %options_map ) { 1440 $val =~ s/[\\\']/\\$1/g; 1441 parse_options("$opt'$val'"); 1442 } 1443 1444 return; 1445} 1446 1447sub _restore_globals_after_restart 1448{ 1449 # restore original @INC 1450 @INC = get_list("PERLDB_INC"); 1451 @ini_INC = @INC; 1452 1453 # return pre/postprompt actions and typeahead buffer 1454 $pretype = [ get_list("PERLDB_PRETYPE") ]; 1455 $pre = [ get_list("PERLDB_PRE") ]; 1456 $post = [ get_list("PERLDB_POST") ]; 1457 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead ); 1458 1459 return; 1460} 1461 1462 1463if ( exists $ENV{PERLDB_RESTART} ) { 1464 1465 # We're restarting, so we don't need the flag that says to restart anymore. 1466 delete $ENV{PERLDB_RESTART}; 1467 1468 # $restart = 1; 1469 _restore_shared_globals_after_restart(); 1470 1471 _restore_breakpoints_and_actions(); 1472 1473 # restore options 1474 _restore_options_after_restart(); 1475 1476 _restore_globals_after_restart(); 1477} ## end if (exists $ENV{PERLDB_RESTART... 1478 1479=head2 SETTING UP THE TERMINAL 1480 1481Now, we'll decide how the debugger is going to interact with the user. 1482If there's no TTY, we set the debugger to run non-stop; there's not going 1483to be anyone there to enter commands. 1484 1485=cut 1486 1487use vars qw($notty $console $tty $LINEINFO); 1488use vars qw($lineinfo $doccmd); 1489 1490our ($runnonstop); 1491 1492# Local autoflush to avoid rt#116769, 1493# as calling IO::File methods causes an unresolvable loop 1494# that results in debugger failure. 1495sub _autoflush { 1496 my $o = select($_[0]); 1497 $|++; 1498 select($o); 1499} 1500 1501if ($notty) { 1502 $runnonstop = 1; 1503 share($runnonstop); 1504} 1505 1506=pod 1507 1508If there is a TTY, we have to determine who it belongs to before we can 1509proceed. If this is a client editor or graphical debugger (denoted by 1510the first command-line switch being '-emacs'), we shift this off and 1511set C<$rl> to 0 (XXX ostensibly to do straight reads). 1512 1513=cut 1514 1515else { 1516 1517 # Is Perl being run from a client editor or graphical debugger? 1518 # If so, don't use readline, and set $client_editor = 1. 1519 if ($client_editor = ( @main::ARGV && ( $main::ARGV[0] eq '-emacs' ) )) { 1520 $rl = 0; 1521 shift(@main::ARGV); 1522 } 1523 1524 #require Term::ReadLine; 1525 1526=pod 1527 1528We then determine what the console should be on various systems: 1529 1530=over 4 1531 1532=item * Cygwin - We use C<stdin> instead of a separate device. 1533 1534=cut 1535 1536 if ( $^O eq 'cygwin' ) { 1537 1538 # /dev/tty is binary. use stdin for textmode 1539 undef $console; 1540 } 1541 1542=item * Windows - use C<con>. 1543 1544=cut 1545 1546 elsif ( $^O eq 'MSWin32' and -e "con" ) { 1547 $console = "con"; 1548 } 1549 1550=item * AmigaOS - use C<CONSOLE:>. 1551 1552=cut 1553 1554 elsif ( $^O eq 'amigaos' ) { 1555 $console = "CONSOLE:"; 1556 } 1557 1558=item * VMS - use C<sys$command>. 1559 1560=cut 1561 1562 elsif ($^O eq 'VMS') { 1563 $console = 'sys$command'; 1564 } 1565 1566# Keep this penultimate, on the grounds that it satisfies a wide variety of 1567# Unix-like systems that would otherwise need to be identified individually. 1568 1569=item * Unix - use F</dev/tty>. 1570 1571=cut 1572 1573 elsif ( -e "/dev/tty" ) { 1574 $console = "/dev/tty"; 1575 } 1576 1577# Keep this last. 1578 1579 else { 1580 _db_warn("Can't figure out your console, using stdin"); 1581 undef $console; 1582 } 1583 1584=pod 1585 1586=back 1587 1588Several other systems don't use a specific console. We S<C<undef $console>> 1589for those (Windows using a client editor/graphical debugger, OS/2 1590with a client editor). 1591 1592=cut 1593 1594 if ( ( $^O eq 'MSWin32' ) and ( $client_editor or defined $ENV{EMACS} ) ) { 1595 1596 # /dev/tty is binary. use stdin for textmode 1597 $console = undef; 1598 } 1599 1600 # In OS/2, we need to use STDIN to get textmode too, even though 1601 # it pretty much looks like Unix otherwise. 1602 if ( defined $ENV{OS2_SHELL} and ( $client_editor or $ENV{WINDOWID} ) ) 1603 { # In OS/2 1604 $console = undef; 1605 } 1606 1607=pod 1608 1609If there is a TTY hanging around from a parent, we use that as the console. 1610 1611=cut 1612 1613 $console = $tty if defined $tty; 1614 1615=head2 SOCKET HANDLING 1616 1617The debugger is capable of opening a socket and carrying out a debugging 1618session over the socket. 1619 1620If C<RemotePort> was defined in the options, the debugger assumes that it 1621should try to start a debugging session on that port. It builds the socket 1622and then tries to connect the input and output filehandles to it. 1623 1624=cut 1625 1626 # Handle socket stuff. 1627 1628 if ( defined $remoteport ) { 1629 1630 # If RemotePort was defined in the options, connect input and output 1631 # to the socket. 1632 $IN = $OUT = connect_remoteport(); 1633 } ## end if (defined $remoteport) 1634 1635=pod 1636 1637If no C<RemotePort> was defined, and we want to create a TTY on startup, 1638this is probably a situation where multiple debuggers are running (for example, 1639a backticked command that starts up another debugger). We create a new IN and 1640OUT filehandle, and do the necessary mojo to create a new TTY if we know how 1641and if we can. 1642 1643=cut 1644 1645 # Non-socket. 1646 else { 1647 1648 # Two debuggers running (probably a system or a backtick that invokes 1649 # the debugger itself under the running one). create a new IN and OUT 1650 # filehandle, and do the necessary mojo to create a new tty if we 1651 # know how, and we can. 1652 create_IN_OUT(4) if $CreateTTY & 4; 1653 if ($console) { 1654 1655 # If we have a console, check to see if there are separate ins and 1656 # outs to open. (They are assumed identical if not.) 1657 1658 my ( $i, $o ) = split /,/, $console; 1659 $o = $i unless defined $o; 1660 1661 # read/write on in, or just read, or read on STDIN. 1662 open( IN, '+<', $i ) 1663 || open( IN, '<', $i ) 1664 || open( IN, "<&STDIN" ); 1665 1666 # read/write/create/clobber out, or write/create/clobber out, 1667 # or merge with STDERR, or merge with STDOUT. 1668 open( OUT, '+>', $o ) 1669 || open( OUT, '>', $o ) 1670 || open( OUT, ">&STDERR" ) 1671 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout 1672 1673 } ## end if ($console) 1674 elsif ( not defined $console ) { 1675 1676 # No console. Open STDIN. 1677 open( IN, "<&STDIN" ); 1678 1679 # merge with STDERR, or with STDOUT. 1680 open( OUT, ">&STDERR" ) 1681 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout 1682 $console = 'STDIN/OUT'; 1683 } ## end elsif (not defined $console) 1684 1685 # Keep copies of the filehandles so that when the pager runs, it 1686 # can close standard input without clobbering ours. 1687 if ($console or (not defined($console))) { 1688 $IN = \*IN; 1689 $OUT = \*OUT; 1690 } 1691 } ## end elsif (from if(defined $remoteport)) 1692 1693 # Unbuffer DB::OUT. We need to see responses right away. 1694 _autoflush($OUT); 1695 1696 # Line info goes to debugger output unless pointed elsewhere. 1697 # Pointing elsewhere makes it possible for client editors to 1698 # keep track of file and position. We have both a filehandle 1699 # and a I/O description to keep track of. 1700 $LINEINFO = $OUT unless defined $LINEINFO; 1701 $lineinfo = $console unless defined $lineinfo; 1702 # share($LINEINFO); # <- unable to share globs 1703 share($lineinfo); # 1704 1705=pod 1706 1707To finish initialization, we show the debugger greeting, 1708and then call the C<afterinit()> subroutine if there is one. 1709 1710=cut 1711 1712 # Show the debugger greeting. 1713 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/; 1714 unless ($runnonstop) { 1715 local $\ = ''; 1716 local $, = ''; 1717 if ( $term_pid eq '-1' ) { 1718 print $OUT "\nDaughter DB session started...\n"; 1719 } 1720 else { 1721 print $OUT "\nLoading DB routines from $header\n"; 1722 print $OUT ( 1723 "Editor support ", 1724 $client_editor ? "enabled" : "available", ".\n" 1725 ); 1726 print $OUT 1727"\nEnter h or 'h h' for help, or '$doccmd perldebug' for more help.\n\n"; 1728 } ## end else [ if ($term_pid eq '-1') 1729 } ## end unless ($runnonstop) 1730} ## end else [ if ($notty) 1731 1732# XXX This looks like a bug to me. 1733# Why copy to @ARGS and then futz with @args? 1734@ARGS = @ARGV; 1735# for (@args) { 1736 # Make sure backslashes before single quotes are stripped out, and 1737 # keep args unless they are numeric (XXX why?) 1738 # s/\'/\\\'/g; # removed while not justified understandably 1739 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto 1740# } 1741 1742# If there was an afterinit() sub defined, call it. It will get 1743# executed in our scope, so it can fiddle with debugger globals. 1744if ( defined &afterinit ) { # May be defined in $rcfile 1745 afterinit(); 1746} 1747 1748# Inform us about "Stack dump during die enabled ..." in dieLevel(). 1749use vars qw($I_m_init); 1750 1751$I_m_init = 1; 1752 1753############################################################ Subroutines 1754 1755=head1 SUBROUTINES 1756 1757=head2 DB 1758 1759This gigantic subroutine is the heart of the debugger. Called before every 1760statement, its job is to determine if a breakpoint has been reached, and 1761stop if so; read commands from the user, parse them, and execute 1762them, and then send execution off to the next statement. 1763 1764Note that the order in which the commands are processed is very important; 1765some commands earlier in the loop will actually alter the C<$cmd> variable 1766to create other commands to be executed later. This is all highly I<optimized> 1767but can be confusing. Check the comments for each C<$cmd ... && do {}> to 1768see what's happening in any given command. 1769 1770=cut 1771 1772# $cmd cannot be an our() variable unfortunately (possible perl bug?). 1773 1774use vars qw( 1775 $action 1776 $cmd 1777 $file 1778 $filename_ini 1779 $finished 1780 %had_breakpoints 1781 $level 1782 $max 1783 $package 1784 $try 1785); 1786 1787our ( 1788 %alias, 1789 $doret, 1790 $end, 1791 $fall_off_end, 1792 $incr, 1793 $laststep, 1794 $rc, 1795 $sh, 1796 $stack_depth, 1797 @stack, 1798 @to_watch, 1799 @old_watch, 1800); 1801 1802sub _DB__use_full_path 1803{ 1804 # If running in the perl test suite, don't use old system libs 1805 return &{$_[0]} if $ENV{PERL_CORE}; 1806 local @INC = @INC; 1807 eval { require Config; }; 1808 unshift(@INC, 1809 @Config::Config{qw(archlibexp privlibexp sitearchexp sitelibexp)}); 1810 &{$_[0]}; 1811} 1812 1813sub _DB__determine_if_we_should_break 1814{ 1815 # if we have something here, see if we should break. 1816 # $stop is lexical and local to this block - $action on the other hand 1817 # is global. 1818 my $stop; 1819 1820 if ( $dbline{$line} 1821 && _is_breakpoint_enabled($filename, $line) 1822 && (( $stop, $action ) = split( /\0/, $dbline{$line} ) ) ) 1823 { 1824 1825 # Stop if the stop criterion says to just stop. 1826 if ( $stop eq '1' ) { 1827 $signal |= 1; 1828 } 1829 1830 # It's a conditional stop; eval it in the user's context and 1831 # see if we should stop. If so, remove the one-time sigil. 1832 elsif ($stop) { 1833 $evalarg = "\$DB::signal |= 1 if do {$stop}"; 1834 # The &-call is here to ascertain the mutability of @_. 1835 &DB::eval; 1836 # If the breakpoint is temporary, then delete its enabled status. 1837 if ($dbline{$line} =~ s/;9($|\0)/$1/) { 1838 _cancel_breakpoint_temp_enabled_status($filename, $line); 1839 } 1840 } 1841 } ## end if ($dbline{$line} && ... 1842} 1843 1844sub _DB__is_finished { 1845 if ($finished and $level <= 1) { 1846 end_report(); 1847 return 1; 1848 } 1849 else { 1850 return; 1851 } 1852} 1853 1854sub _DB__read_next_cmd 1855{ 1856 my ($tid) = @_; 1857 1858 # We have a terminal, or can get one ... 1859 if (!$term) { 1860 setterm(); 1861 } 1862 1863 # ... and it belongs to this PID or we get one for this PID ... 1864 if ($term_pid != $$) { 1865 resetterm(1); 1866 } 1867 1868 # ... and we got a line of command input ... 1869 $cmd = DB::readline( 1870 "$pidprompt $tid DB" 1871 . ( '<' x $level ) 1872 . ( $#hist + 1 ) 1873 . ( '>' x $level ) . " " 1874 ); 1875 1876 return defined($cmd); 1877} 1878 1879sub _DB__trim_command_and_return_first_component { 1880 my ($obj) = @_; 1881 1882 $cmd =~ s/\A\s+//s; # trim annoying leading whitespace 1883 $cmd =~ s/\s+\z//s; # trim annoying trailing whitespace 1884 1885 # A single-character debugger command can be immediately followed by its 1886 # argument if they aren't both alphanumeric; otherwise require space 1887 # between commands and arguments: 1888 my ($verb, $args) = $cmd =~ m{\A([^\.-]\b|\S*)\s*(.*)}s; 1889 1890 $obj->cmd_verb($verb); 1891 $obj->cmd_args($args); 1892 1893 return; 1894} 1895 1896sub _DB__handle_f_command { 1897 my ($obj) = @_; 1898 1899 if ($file = $obj->cmd_args) { 1900 # help for no arguments (old-style was return from sub). 1901 if ( !$file ) { 1902 print $OUT 1903 "The old f command is now the r command.\n"; # hint 1904 print $OUT "The new f command switches filenames.\n"; 1905 next CMD; 1906 } ## end if (!$file) 1907 1908 # if not in magic file list, try a close match. 1909 if ( !defined $main::{ '_<' . $file } ) { 1910 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) { 1911 { 1912 $try = substr( $try, 2 ); 1913 print $OUT "Choosing $try matching '$file':\n"; 1914 $file = $try; 1915 } 1916 } ## end if (($try) = grep(m#^_<.*$file#... 1917 } ## end if (!defined $main::{ ... 1918 1919 # If not successfully switched now, we failed. 1920 if ( !defined $main::{ '_<' . $file } ) { 1921 print $OUT "No file matching '$file' is loaded.\n"; 1922 next CMD; 1923 } 1924 1925 # We switched, so switch the debugger internals around. 1926 elsif ( $file ne $filename ) { 1927 *dbline = $main::{ '_<' . $file }; 1928 $max = $#dbline; 1929 $filename = $file; 1930 $start = 1; 1931 $cmd = "l"; 1932 } ## end elsif ($file ne $filename) 1933 1934 # We didn't switch; say we didn't. 1935 else { 1936 print $OUT "Already in $file.\n"; 1937 next CMD; 1938 } 1939 } 1940 1941 return; 1942} 1943 1944sub _DB__handle_dot_command { 1945 my ($obj) = @_; 1946 1947 # . command. 1948 if ($obj->_is_full('.')) { 1949 $incr = -1; # stay at current line 1950 1951 # Reset everything to the old location. 1952 $start = $line; 1953 $filename = $filename_ini; 1954 *dbline = $main::{ '_<' . $filename }; 1955 $max = $#dbline; 1956 1957 # Now where are we? 1958 print_lineinfo($obj->position()); 1959 next CMD; 1960 } 1961 1962 return; 1963} 1964 1965sub _DB__handle_y_command { 1966 my ($obj) = @_; 1967 1968 if (my ($match_level, $match_vars) 1969 = $obj->cmd_args =~ /\A(?:(\d*)\s*(.*))?\z/) { 1970 1971 # See if we've got the necessary support. 1972 if (!eval { 1973 local @INC = @INC; 1974 pop @INC if $INC[-1] eq '.'; 1975 _DB__use_full_path(sub { 1976 require PadWalker; 1977 }); 1978 PadWalker->VERSION(0.08) }) { 1979 my $Err = $@; 1980 _db_warn( 1981 $Err =~ /locate/ 1982 ? "PadWalker module not found - please install\n" 1983 : $Err 1984 ); 1985 next CMD; 1986 } 1987 1988 # Load up dumpvar if we don't have it. If we can, that is. 1989 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; 1990 defined &main::dumpvar 1991 or print $OUT "dumpvar.pl not available.\n" 1992 and next CMD; 1993 1994 # Got all the modules we need. Find them and print them. 1995 my @vars = split( ' ', $match_vars || '' ); 1996 1997 # Find the pad. 1998 my $h = eval { PadWalker::peek_my( ( $match_level || 0 ) + 2 ) }; 1999 2000 # Oops. Can't find it. 2001 if (my $Err = $@) { 2002 $Err =~ s/ at .*//; 2003 _db_warn($Err); 2004 next CMD; 2005 } 2006 2007 # Show the desired vars with dumplex(). 2008 my $savout = select($OUT); 2009 2010 # Have dumplex dump the lexicals. 2011 foreach my $key (sort keys %$h) { 2012 dumpvar::dumplex( $key, $h->{$key}, 2013 defined $option{dumpDepth} ? $option{dumpDepth} : -1, 2014 @vars ); 2015 } 2016 select($savout); 2017 next CMD; 2018 } 2019} 2020 2021sub _DB__handle_c_command { 2022 my ($obj) = @_; 2023 2024 my $i = $obj->cmd_args; 2025 2026 if ($i =~ m#\A[\w:]*\z#) { 2027 2028 # Hey, show's over. The debugged program finished 2029 # executing already. 2030 next CMD if _DB__is_finished(); 2031 2032 # Capture the place to put a one-time break. 2033 $subname = $i; 2034 2035 # Probably not needed, since we finish an interactive 2036 # sub-session anyway... 2037 # local $filename = $filename; 2038 # local *dbline = *dbline; # XXX Would this work?! 2039 # 2040 # The above question wonders if localizing the alias 2041 # to the magic array works or not. Since it's commented 2042 # out, we'll just leave that to speculation for now. 2043 2044 # If the "subname" isn't all digits, we'll assume it 2045 # is a subroutine name, and try to find it. 2046 if ( $subname =~ /\D/ ) { # subroutine name 2047 # Qualify it to the current package unless it's 2048 # already qualified. 2049 $subname = $package . "::" . $subname 2050 unless $subname =~ /::/; 2051 2052 # find_sub will return "file:line_number" corresponding 2053 # to where the subroutine is defined; we call find_sub, 2054 # break up the return value, and assign it in one 2055 # operation. 2056 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ ); 2057 2058 # Force the line number to be numeric. 2059 $i = $i + 0; 2060 2061 # If we got a line number, we found the sub. 2062 if ($i) { 2063 2064 # Switch all the debugger's internals around so 2065 # we're actually working with that file. 2066 $filename = $file; 2067 *dbline = $main::{ '_<' . $filename }; 2068 2069 # Mark that there's a breakpoint in this file. 2070 $had_breakpoints{$filename} |= 1; 2071 2072 # Scan forward to the first executable line 2073 # after the 'sub whatever' line. 2074 $max = $#dbline; 2075 my $_line_num = $i; 2076 while ($dbline[$_line_num] == 0 && $_line_num< $max) 2077 { 2078 $_line_num++; 2079 } 2080 $i = $_line_num; 2081 } ## end if ($i) 2082 2083 # We didn't find a sub by that name. 2084 else { 2085 print $OUT "Subroutine $subname not found.\n"; 2086 next CMD; 2087 } 2088 } ## end if ($subname =~ /\D/) 2089 2090 # At this point, either the subname was all digits (an 2091 # absolute line-break request) or we've scanned through 2092 # the code following the definition of the sub, looking 2093 # for an executable, which we may or may not have found. 2094 # 2095 # If $i (which we set $subname from) is non-zero, we 2096 # got a request to break at some line somewhere. On 2097 # one hand, if there wasn't any real subroutine name 2098 # involved, this will be a request to break in the current 2099 # file at the specified line, so we have to check to make 2100 # sure that the line specified really is breakable. 2101 # 2102 # On the other hand, if there was a subname supplied, the 2103 # preceding block has moved us to the proper file and 2104 # location within that file, and then scanned forward 2105 # looking for the next executable line. We have to make 2106 # sure that one was found. 2107 # 2108 # On the gripping hand, we can't do anything unless the 2109 # current value of $i points to a valid breakable line. 2110 # Check that. 2111 if ($i) { 2112 2113 # Breakable? 2114 if ( $dbline[$i] == 0 ) { 2115 print $OUT "Line $i not breakable.\n"; 2116 next CMD; 2117 } 2118 2119 # Yes. Set up the one-time-break sigil. 2120 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p. 2121 _enable_breakpoint_temp_enabled_status($filename, $i); 2122 } ## end if ($i) 2123 2124 # Turn off stack tracing from here up. 2125 for my $j (0 .. $stack_depth) { 2126 $stack[ $j ] &= ~1; 2127 } 2128 last CMD; 2129 } 2130 2131 return; 2132} 2133 2134my $sub_twice = chr utf8::unicode_to_native(032); 2135$sub_twice = $sub_twice x 2; 2136 2137sub _DB__handle_forward_slash_command { 2138 my ($obj) = @_; 2139 2140 # The pattern as a string. 2141 use vars qw($inpat); 2142 2143 if (($inpat) = $cmd =~ m#\A/(.*)\z#) { 2144 2145 # Remove the final slash. 2146 $inpat =~ s:([^\\])/$:$1:; 2147 2148 # If the pattern isn't null ... 2149 if ( $inpat ne "" ) { 2150 2151 # Turn off warn and die processing for a bit. 2152 local $SIG{__DIE__}; 2153 local $SIG{__WARN__}; 2154 2155 # Create the pattern. 2156 eval 'no strict q/vars/; $inpat =~ m' . "\a$inpat\a"; 2157 if ( $@ ne "" ) { 2158 2159 # Oops. Bad pattern. No biscuit. 2160 # Print the eval error and go back for more 2161 # commands. 2162 print {$OUT} "$@"; 2163 next CMD; 2164 } 2165 $obj->pat($inpat); 2166 } ## end if ($inpat ne "") 2167 2168 # Set up to stop on wrap-around. 2169 $end = $start; 2170 2171 # Don't move off the current line. 2172 $incr = -1; 2173 2174 my $pat = $obj->pat; 2175 2176 # Done in eval so nothing breaks if the pattern 2177 # does something weird. 2178 eval 2179 { 2180 no strict q/vars/; 2181 for (;;) { 2182 # Move ahead one line. 2183 ++$start; 2184 2185 # Wrap if we pass the last line. 2186 if ($start > $max) { 2187 $start = 1; 2188 } 2189 2190 # Stop if we have gotten back to this line again, 2191 last if ($start == $end); 2192 2193 # A hit! (Note, though, that we are doing 2194 # case-insensitive matching. Maybe a qr// 2195 # expression would be better, so the user could 2196 # do case-sensitive matching if desired. 2197 if ($dbline[$start] =~ m/$pat/i) { 2198 if ($client_editor) { 2199 # Handle proper escaping in the client. 2200 print {$OUT} "$sub_twice$filename:$start:0\n"; 2201 } 2202 else { 2203 # Just print the line normally. 2204 print {$OUT} "$start:\t",$dbline[$start],"\n"; 2205 } 2206 # And quit since we found something. 2207 last; 2208 } 2209 } 2210 }; 2211 2212 if ($@) { 2213 warn $@; 2214 } 2215 2216 # If we wrapped, there never was a match. 2217 if ( $start == $end ) { 2218 print {$OUT} "/$pat/: not found\n"; 2219 } 2220 next CMD; 2221 } 2222 2223 return; 2224} 2225 2226sub _DB__handle_question_mark_command { 2227 my ($obj) = @_; 2228 2229 # ? - backward pattern search. 2230 if (my ($inpat) = $cmd =~ m#\A\?(.*)\z#) { 2231 2232 # Get the pattern, remove trailing question mark. 2233 $inpat =~ s:([^\\])\?$:$1:; 2234 2235 # If we've got one ... 2236 if ( $inpat ne "" ) { 2237 2238 # Turn off die & warn handlers. 2239 local $SIG{__DIE__}; 2240 local $SIG{__WARN__}; 2241 eval '$inpat =~ m' . "\a$inpat\a"; 2242 2243 if ( $@ ne "" ) { 2244 2245 # Ouch. Not good. Print the error. 2246 print $OUT $@; 2247 next CMD; 2248 } 2249 $obj->pat($inpat); 2250 } ## end if ($inpat ne "") 2251 2252 # Where we are now is where to stop after wraparound. 2253 $end = $start; 2254 2255 # Don't move away from this line. 2256 $incr = -1; 2257 2258 my $pat = $obj->pat; 2259 # Search inside the eval to prevent pattern badness 2260 # from killing us. 2261 eval { 2262 no strict q/vars/; 2263 for (;;) { 2264 # Back up a line. 2265 --$start; 2266 2267 # Wrap if we pass the first line. 2268 2269 $start = $max if ($start <= 0); 2270 2271 # Quit if we get back where we started, 2272 last if ($start == $end); 2273 2274 # Match? 2275 if ($dbline[$start] =~ m/$pat/i) { 2276 if ($client_editor) { 2277 # Yep, follow client editor requirements. 2278 print $OUT "$sub_twice$filename:$start:0\n"; 2279 } 2280 else { 2281 # Yep, just print normally. 2282 print $OUT "$start:\t",$dbline[$start],"\n"; 2283 } 2284 2285 # Found, so done. 2286 last; 2287 } 2288 } 2289 }; 2290 2291 # Say we failed if the loop never found anything, 2292 if ( $start == $end ) { 2293 print {$OUT} "?$pat?: not found\n"; 2294 } 2295 next CMD; 2296 } 2297 2298 return; 2299} 2300 2301sub _DB__handle_restart_and_rerun_commands { 2302 my ($obj) = @_; 2303 2304 my $cmd_cmd = $obj->cmd_verb; 2305 my $cmd_params = $obj->cmd_args; 2306 # R - restart execution. 2307 # rerun - controlled restart execution. 2308 if ($cmd_cmd eq 'rerun' or $cmd_params eq '') { 2309 2310 # Change directory to the initial current working directory on 2311 # the script startup, so if the debugged program changed the 2312 # directory, then we will still be able to find the path to the 2313 # program. (perl 5 RT #121509 ). 2314 chdir ($_initial_cwd); 2315 2316 my @args = ($cmd_cmd eq 'R' ? restart() : rerun($cmd_params)); 2317 2318 # Close all non-system fds for a clean restart. A more 2319 # correct method would be to close all fds that were not 2320 # open when the process started, but this seems to be 2321 # hard. See "debugger 'R'estart and open database 2322 # connections" on p5p. 2323 2324 my $max_fd = 1024; # default if POSIX can't be loaded 2325 if (eval { require POSIX }) { 2326 eval { $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()) }; 2327 } 2328 2329 if (defined $max_fd) { 2330 foreach ($^F+1 .. $max_fd-1) { 2331 next unless open FD_TO_CLOSE, "<&=$_"; 2332 close(FD_TO_CLOSE); 2333 } 2334 } 2335 2336 # And run Perl again. We use exec() to keep the 2337 # PID stable (and that way $ini_pids is still valid). 2338 exec(@args) or print {$OUT} "exec failed: $!\n"; 2339 2340 last CMD; 2341 } 2342 2343 return; 2344} 2345 2346sub _DB__handle_run_command_in_pager_command { 2347 my ($obj) = @_; 2348 2349 if ($cmd =~ m#\A\|\|?\s*[^|]#) { 2350 if ( $pager =~ /^\|/ ) { 2351 2352 # Default pager is into a pipe. Redirect I/O. 2353 open( SAVEOUT, ">&STDOUT" ) 2354 || _db_warn("Can't save STDOUT"); 2355 open( STDOUT, ">&OUT" ) 2356 || _db_warn("Can't redirect STDOUT"); 2357 } ## end if ($pager =~ /^\|/) 2358 else { 2359 2360 # Not into a pipe. STDOUT is safe. 2361 open( SAVEOUT, ">&OUT" ) || _db_warn("Can't save DB::OUT"); 2362 } 2363 2364 # Fix up environment to record we have less if so. 2365 fix_less(); 2366 2367 unless ( $obj->piped(scalar ( open( OUT, $pager ) ) ) ) { 2368 2369 # Couldn't open pipe to pager. 2370 _db_warn("Can't pipe output to '$pager'"); 2371 if ( $pager =~ /^\|/ ) { 2372 2373 # Redirect I/O back again. 2374 open( OUT, ">&STDOUT" ) # XXX: lost message 2375 || _db_warn("Can't restore DB::OUT"); 2376 open( STDOUT, ">&SAVEOUT" ) 2377 || _db_warn("Can't restore STDOUT"); 2378 close(SAVEOUT); 2379 } ## end if ($pager =~ /^\|/) 2380 else { 2381 2382 # Redirect I/O. STDOUT already safe. 2383 open( OUT, ">&STDOUT" ) # XXX: lost message 2384 || _db_warn("Can't restore DB::OUT"); 2385 } 2386 next CMD; 2387 } ## end unless ($piped = open(OUT,... 2388 2389 # Set up broken-pipe handler if necessary. 2390 $SIG{PIPE} = \&DB::catch 2391 if $pager =~ /^\|/ 2392 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} ); 2393 2394 _autoflush(\*OUT); 2395 # Save current filehandle, and put it back. 2396 $obj->selected(scalar( select(OUT) )); 2397 # Don't put it back if pager was a pipe. 2398 if ($cmd !~ /\A\|\|/) 2399 { 2400 select($obj->selected()); 2401 $obj->selected(""); 2402 } 2403 2404 # Trim off the pipe symbols and run the command now. 2405 $cmd =~ s#\A\|+\s*##; 2406 redo PIPE; 2407 } 2408 2409 return; 2410} 2411 2412sub _DB__handle_m_command { 2413 my ($obj) = @_; 2414 2415 if ($cmd =~ s#\Am\s+([\w:]+)\s*\z# #) { 2416 methods($1); 2417 next CMD; 2418 } 2419 2420 # m expr - set up DB::eval to do the work 2421 if ($cmd =~ s#\Am\b# #) { # Rest gets done by DB::eval() 2422 $onetimeDump = 'methods'; # method output gets used there 2423 } 2424 2425 return; 2426} 2427 2428sub _DB__at_end_of_every_command { 2429 my ($obj) = @_; 2430 2431 # At the end of every command: 2432 if ($obj->piped) { 2433 2434 # Unhook the pipe mechanism now. 2435 if ( $pager =~ /^\|/ ) { 2436 2437 # No error from the child. 2438 $? = 0; 2439 2440 # we cannot warn here: the handle is missing --tchrist 2441 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n"; 2442 2443 # most of the $? crud was coping with broken cshisms 2444 # $? is explicitly set to 0, so this never runs. 2445 if ($?) { 2446 print SAVEOUT "Pager '$pager' failed: "; 2447 if ( $? == -1 ) { 2448 print SAVEOUT "shell returned -1\n"; 2449 } 2450 elsif ( $? >> 8 ) { 2451 print SAVEOUT ( $? & 127 ) 2452 ? " (SIG#" . ( $? & 127 ) . ")" 2453 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n"; 2454 } 2455 else { 2456 print SAVEOUT "status ", ( $? >> 8 ), "\n"; 2457 } 2458 } ## end if ($?) 2459 2460 # Reopen filehandle for our output (if we can) and 2461 # restore STDOUT (if we can). 2462 open( OUT, ">&STDOUT" ) || _db_warn("Can't restore DB::OUT"); 2463 open( STDOUT, ">&SAVEOUT" ) 2464 || _db_warn("Can't restore STDOUT"); 2465 2466 # Turn off pipe exception handler if necessary. 2467 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch; 2468 2469 # Will stop ignoring SIGPIPE if done like nohup(1) 2470 # does SIGINT but Perl doesn't give us a choice. 2471 } ## end if ($pager =~ /^\|/) 2472 else { 2473 2474 # Non-piped "pager". Just restore STDOUT. 2475 open( OUT, ">&SAVEOUT" ) || _db_warn("Can't restore DB::OUT"); 2476 } 2477 2478 # Let Readline know about the new filehandles. 2479 reset_IN_OUT( \*IN, \*OUT ); 2480 2481 # Close filehandle pager was using, restore the normal one 2482 # if necessary, 2483 close(SAVEOUT); 2484 2485 if ($obj->selected() ne "") { 2486 select($obj->selected); 2487 $obj->selected(""); 2488 } 2489 2490 # No pipes now. 2491 $obj->piped(""); 2492 } ## end if ($piped) 2493 2494 return; 2495} 2496 2497sub _DB__handle_watch_expressions 2498{ 2499 my $self = shift; 2500 2501 if ( $DB::trace & 2 ) { 2502 for my $n (0 .. $#DB::to_watch) { 2503 $DB::evalarg = $DB::to_watch[$n]; 2504 local $DB::onetimeDump; # Tell DB::eval() to not output results 2505 2506 # Fix context DB::eval() wants to return an array, but 2507 # we need a scalar here. 2508 my ($val) = join( "', '", DB::eval(@_) ); 2509 $val = ( ( defined $val ) ? "'$val'" : 'undef' ); 2510 2511 # Did it change? 2512 if ( $val ne $DB::old_watch[$n] ) { 2513 2514 # Yep! Show the difference, and fake an interrupt. 2515 $DB::signal = 1; 2516 print {$DB::OUT} <<EOP; 2517Watchpoint $n:\t$DB::to_watch[$n] changed: 2518 old value:\t$DB::old_watch[$n] 2519 new value:\t$val 2520EOP 2521 $DB::old_watch[$n] = $val; 2522 } ## end if ($val ne $old_watch... 2523 } ## end for my $n (0 .. 2524 } ## end if ($trace & 2) 2525 2526 return; 2527} 2528 2529=head3 C<_DB__handle_i_command> - inheritance display 2530 2531Display the (nested) parentage of the module or object given. 2532 2533=cut 2534 2535sub _DB__handle_i_command { 2536 my $self = shift; 2537 2538 my $line = $self->cmd_args; 2539 require mro; 2540 foreach my $isa ( split( /\s+/, $line ) ) { 2541 $evalarg = "$isa"; 2542 # The &-call is here to ascertain the mutability of @_. 2543 ($isa) = &DB::eval; 2544 no strict 'refs'; 2545 print join( 2546 ', ', 2547 map { 2548 "$_" 2549 . ( 2550 defined( ${"$_\::VERSION"} ) 2551 ? ' ' . ${"$_\::VERSION"} 2552 : undef ) 2553 } @{mro::get_linear_isa(ref($isa) || $isa)} 2554 ); 2555 print "\n"; 2556 } 2557 next CMD; 2558} 2559 2560=head3 C<_cmd_l_main> - list lines (command) 2561 2562Most of the command is taken up with transforming all the different line 2563specification syntaxes into 'start-stop'. After that is done, the command 2564runs a loop over C<@dbline> for the specified range of lines. It handles 2565the printing of each line and any markers (C<==E<gt>> for current line, 2566C<b> for break on this line, C<a> for action on this line, C<:> for this 2567line breakable). 2568 2569We save the last line listed in the C<$start> global for further listing 2570later. 2571 2572=cut 2573 2574sub _min { 2575 my $min = shift; 2576 foreach my $v (@_) { 2577 if ($min > $v) { 2578 $min = $v; 2579 } 2580 } 2581 return $min; 2582} 2583 2584sub _max { 2585 my $max = shift; 2586 foreach my $v (@_) { 2587 if ($max < $v) { 2588 $max = $v; 2589 } 2590 } 2591 return $max; 2592} 2593 2594sub _minify_to_max { 2595 my $ref = shift; 2596 2597 $$ref = _min($$ref, $max); 2598 2599 return; 2600} 2601 2602sub _cmd_l_handle_var_name { 2603 my $var_name = shift; 2604 2605 $evalarg = $var_name; 2606 2607 my ($s) = DB::eval(); 2608 2609 # Ooops. Bad scalar. 2610 if ($@) { 2611 print {$OUT} "Error: $@\n"; 2612 next CMD; 2613 } 2614 2615 # Good scalar. If it's a reference, find what it points to. 2616 $s = CvGV_name($s); 2617 print {$OUT} "Interpreted as: $1 $s\n"; 2618 $line = "$1 $s"; 2619 2620 # Call self recursively to really do the command. 2621 return _cmd_l_main( $s ); 2622} 2623 2624sub _cmd_l_handle_subname { 2625 2626 my $s = $subname; 2627 2628 # De-Perl4. 2629 $subname =~ s/\'/::/; 2630 2631 # Put it in this package unless it starts with ::. 2632 $subname = $package . "::" . $subname unless $subname =~ /::/; 2633 2634 # Put it in CORE::GLOBAL if t doesn't start with :: and 2635 # it doesn't live in this package and it lives in CORE::GLOBAL. 2636 $subname = "CORE::GLOBAL::$s" 2637 if not defined &$subname 2638 and $s !~ /::/ 2639 and defined &{"CORE::GLOBAL::$s"}; 2640 2641 # Put leading '::' names into 'main::'. 2642 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 2643 2644 # Get name:start-stop from find_sub, and break this up at 2645 # colons. 2646 my @pieces = split( /:/, find_sub($subname) || $sub{$subname} ); 2647 2648 # Pull off start-stop. 2649 my $subrange = pop @pieces; 2650 2651 # If the name contained colons, the split broke it up. 2652 # Put it back together. 2653 $file = join( ':', @pieces ); 2654 2655 # If we're not in that file, switch over to it. 2656 if ( $file ne $filename ) { 2657 if (! $client_editor) { 2658 print {$OUT} "Switching to file '$file'.\n"; 2659 } 2660 2661 # Switch debugger's magic structures. 2662 *dbline = $main::{ '_<' . $file }; 2663 $max = $#dbline; 2664 $filename = $file; 2665 } ## end if ($file ne $filename) 2666 2667 # Subrange is 'start-stop'. If this is less than a window full, 2668 # swap it to 'start+', which will list a window from the start point. 2669 if ($subrange) { 2670 if ( eval($subrange) < -$window ) { 2671 $subrange =~ s/-.*/+/; 2672 } 2673 2674 # Call self recursively to list the range. 2675 return _cmd_l_main( $subrange ); 2676 } ## end if ($subrange) 2677 2678 # Couldn't find it. 2679 else { 2680 print {$OUT} "Subroutine $subname not found.\n"; 2681 return; 2682 } 2683} 2684 2685sub _cmd_l_empty { 2686 # Compute new range to list. 2687 $incr = $window - 1; 2688 2689 # Recurse to do it. 2690 return _cmd_l_main( $start . '-' . ( $start + $incr ) ); 2691} 2692 2693sub _cmd_l_plus { 2694 my ($new_start, $new_incr) = @_; 2695 2696 # Don't reset start for 'l +nnn'. 2697 $start = $new_start if $new_start; 2698 2699 # Increment for list. Use window size if not specified. 2700 # (Allows 'l +' to work.) 2701 $incr = $new_incr || ($window - 1); 2702 2703 # Create a line range we'll understand, and recurse to do it. 2704 return _cmd_l_main( $start . '-' . ( $start + $incr ) ); 2705} 2706 2707sub _cmd_l_calc_initial_end_and_i { 2708 my ($spec, $start_match, $end_match) = @_; 2709 2710 # Determine end point; use end of file if not specified. 2711 my $end = ( !defined $start_match ) ? $max : 2712 ( $end_match ? $end_match : $start_match ); 2713 2714 # Go on to the end, and then stop. 2715 _minify_to_max(\$end); 2716 2717 # Determine start line. 2718 my $i = $start_match; 2719 2720 if ($i eq '.') { 2721 $i = $spec; 2722 } 2723 2724 $i = _max($i, 1); 2725 2726 $incr = $end - $i; 2727 2728 return ($end, $i); 2729} 2730 2731sub _cmd_l_range { 2732 my ($spec, $current_line, $start_match, $end_match) = @_; 2733 2734 my ($end, $i) = 2735 _cmd_l_calc_initial_end_and_i($spec, $start_match, $end_match); 2736 2737 # If we're running under a client editor, force it to show the lines. 2738 if ($client_editor) { 2739 print {$OUT} "$sub_twice$filename:$i:0\n"; 2740 $i = $end; 2741 } 2742 # We're doing it ourselves. We want to show the line and special 2743 # markers for: 2744 # - the current line in execution 2745 # - whether a line is breakable or not 2746 # - whether a line has a break or not 2747 # - whether a line has an action or not 2748 else { 2749 I_TO_END: 2750 for ( ; $i <= $end ; $i++ ) { 2751 2752 # Check for breakpoints and actions. 2753 my ( $stop, $action ); 2754 if ($dbline{$i}) { 2755 ( $stop, $action ) = split( /\0/, $dbline{$i} ); 2756 } 2757 2758 # ==> if this is the current line in execution, 2759 # : if it's breakable. 2760 my $arrow = 2761 ( $i == $current_line and $filename eq $filename_ini ) 2762 ? '==>' 2763 : ( $dbline[$i] + 0 ? ':' : ' ' ); 2764 2765 # Add break and action indicators. 2766 $arrow .= 'b' if $stop; 2767 $arrow .= 'a' if $action; 2768 2769 # Print the line. 2770 print {$OUT} "$i$arrow\t", $dbline[$i]; 2771 2772 # Move on to the next line. Drop out on an interrupt. 2773 if ($signal) { 2774 $i++; 2775 last I_TO_END; 2776 } 2777 } ## end for (; $i <= $end ; $i++) 2778 2779 # Line the prompt up; print a newline if the last line listed 2780 # didn't have a newline. 2781 if ($dbline[ $i - 1 ] !~ /\n\z/) { 2782 print {$OUT} "\n"; 2783 } 2784 } ## end else [ if ($client_editor) 2785 2786 # Save the point we last listed to in case another relative 'l' 2787 # command is desired. Don't let it run off the end. 2788 $start = $i; 2789 _minify_to_max(\$start); 2790 2791 return; 2792} 2793 2794sub _cmd_l_main { 2795 my $spec = shift; 2796 2797 # If this is '-something', delete any spaces after the dash. 2798 $spec =~ s/\A-\s*\z/-/; 2799 2800 # If the line is '$something', assume this is a scalar containing a 2801 # line number. 2802 # Set up for DB::eval() - evaluate in *user* context. 2803 if ( my ($var_name) = $spec =~ /\A(\$.*)/s ) { 2804 return _cmd_l_handle_var_name($var_name); 2805 } 2806 # l name. Try to find a sub by that name. 2807 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) { 2808 return _cmd_l_handle_subname(); 2809 } 2810 # Bare 'l' command. 2811 elsif ( $spec !~ /\S/ ) { 2812 return _cmd_l_empty(); 2813 } 2814 # l [start]+number_of_lines 2815 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) { 2816 return _cmd_l_plus($new_start, $new_incr); 2817 } 2818 # l start-stop or l start,stop 2819 elsif (my ($s, $e) = $spec =~ /^(?:(-?[\d\$\.]+)(?:[-,]([\d\$\.]+))?)?/ ) { 2820 return _cmd_l_range($spec, $line, $s, $e); 2821 } 2822 2823 return; 2824} ## end sub _cmd_l_main 2825 2826sub _DB__handle_l_command { 2827 my $self = shift; 2828 2829 _cmd_l_main($self->cmd_args); 2830 next CMD; 2831} 2832 2833 2834# 't' is type. 2835# 'm' is method. 2836# 'v' is the value (i.e: method name or subroutine ref). 2837# 's' is subroutine. 2838my %cmd_lookup; 2839 2840BEGIN 2841{ 2842 %cmd_lookup = 2843( 2844 '-' => { t => 'm', v => '_handle_dash_command', }, 2845 '.' => { t => 's', v => \&_DB__handle_dot_command, }, 2846 '=' => { t => 'm', v => '_handle_equal_sign_command', }, 2847 'H' => { t => 'm', v => '_handle_H_command', }, 2848 'S' => { t => 'm', v => '_handle_S_command', }, 2849 'T' => { t => 'm', v => '_handle_T_command', }, 2850 'W' => { t => 'm', v => '_handle_W_command', }, 2851 'c' => { t => 's', v => \&_DB__handle_c_command, }, 2852 'f' => { t => 's', v => \&_DB__handle_f_command, }, 2853 'i' => { t => 's', v => \&_DB__handle_i_command, }, 2854 'l' => { t => 's', v => \&_DB__handle_l_command, }, 2855 'm' => { t => 's', v => \&_DB__handle_m_command, }, 2856 'n' => { t => 'm', v => '_handle_n_command', }, 2857 'p' => { t => 'm', v => '_handle_p_command', }, 2858 'q' => { t => 'm', v => '_handle_q_command', }, 2859 'r' => { t => 'm', v => '_handle_r_command', }, 2860 's' => { t => 'm', v => '_handle_s_command', }, 2861 'save' => { t => 'm', v => '_handle_save_command', }, 2862 'source' => { t => 'm', v => '_handle_source_command', }, 2863 't' => { t => 'm', v => '_handle_t_command', }, 2864 'w' => { t => 'm', v => '_handle_w_command', }, 2865 'x' => { t => 'm', v => '_handle_x_command', }, 2866 'y' => { t => 's', v => \&_DB__handle_y_command, }, 2867 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, } 2868 ('X', 'V')), 2869 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, } 2870 qw(enable disable)), 2871 (map { $_ => 2872 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, }, 2873 } qw(R rerun)), 2874 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, } 2875 qw(a A b B e E h L M o O v w W)), 2876); 2877}; 2878 2879sub DB { 2880 2881 # lock the debugger and get the thread id for the prompt 2882 lock($DBGR); 2883 my $tid; 2884 my $position; 2885 my ($prefix, $after, $infix); 2886 my $pat; 2887 my $explicit_stop; 2888 my $piped; 2889 my $selected; 2890 2891 if ($ENV{PERL5DB_THREADED}) { 2892 $tid = eval { "[".threads->tid."]" }; 2893 } 2894 2895 my $cmd_verb; 2896 my $cmd_args; 2897 2898 my $obj = DB::Obj->new( 2899 { 2900 position => \$position, 2901 prefix => \$prefix, 2902 after => \$after, 2903 explicit_stop => \$explicit_stop, 2904 infix => \$infix, 2905 cmd_args => \$cmd_args, 2906 cmd_verb => \$cmd_verb, 2907 pat => \$pat, 2908 piped => \$piped, 2909 selected => \$selected, 2910 }, 2911 ); 2912 2913 $obj->_DB_on_init__initialize_globals(@_); 2914 2915 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W. 2916 # The code being debugged may have altered them. 2917 DB::save(); 2918 2919 # Since DB::DB gets called after every line, we can use caller() to 2920 # figure out where we last were executing. Sneaky, eh? This works because 2921 # caller is returning all the extra information when called from the 2922 # debugger. 2923 local ( $package, $filename, $line ) = caller; 2924 $filename_ini = $filename; 2925 2926 # set up the context for DB::eval, so it can properly execute 2927 # code on behalf of the user. We add the package in so that the 2928 # code is eval'ed in the proper package (not in the debugger!). 2929 local $usercontext = _calc_usercontext($package); 2930 2931 # Create an alias to the active file magical array to simplify 2932 # the code here. 2933 local (*dbline) = $main::{ '_<' . $filename }; 2934 2935 # Last line in the program. 2936 $max = $#dbline; 2937 2938 # The &-call is here to ascertain the mutability of @_. 2939 &_DB__determine_if_we_should_break; 2940 2941 # Preserve the current stop-or-not, and see if any of the W 2942 # (watch expressions) has changed. 2943 my $was_signal = $signal; 2944 2945 # If we have any watch expressions ... 2946 _DB__handle_watch_expressions($obj); 2947 2948=head2 C<watchfunction()> 2949 2950C<watchfunction()> is a function that can be defined by the user; it is a 2951function which will be run on each entry to C<DB::DB>; it gets the 2952current package, filename, and line as its parameters. 2953 2954The watchfunction can do anything it likes; it is executing in the 2955debugger's context, so it has access to all of the debugger's internal 2956data structures and functions. 2957 2958C<watchfunction()> can control the debugger's actions. Any of the following 2959will cause the debugger to return control to the user's program after 2960C<watchfunction()> executes: 2961 2962=over 4 2963 2964=item * 2965 2966Returning a false value from the C<watchfunction()> itself. 2967 2968=item * 2969 2970Altering C<$single> to a false value. 2971 2972=item * 2973 2974Altering C<$signal> to a false value. 2975 2976=item * 2977 2978Turning off the C<4> bit in C<$trace> (this also disables the 2979check for C<watchfunction()>. This can be done with 2980 2981 $trace &= ~4; 2982 2983=back 2984 2985=cut 2986 2987 # If there's a user-defined DB::watchfunction, call it with the 2988 # current package, filename, and line. The function executes in 2989 # the DB:: package. 2990 if ( $trace & 4 ) { # User-installed watch 2991 return 2992 if watchfunction( $package, $filename, $line ) 2993 and not $single 2994 and not $was_signal 2995 and not( $trace & ~4 ); 2996 } ## end if ($trace & 4) 2997 2998 # Pick up any alteration to $signal in the watchfunction, and 2999 # turn off the signal now. 3000 $was_signal = $signal; 3001 $signal = 0; 3002 3003=head2 GETTING READY TO EXECUTE COMMANDS 3004 3005The debugger decides to take control if single-step mode is on, the 3006C<t> command was entered, or the user generated a signal. If the program 3007has fallen off the end, we set things up so that entering further commands 3008won't cause trouble, and we say that the program is over. 3009 3010=cut 3011 3012 # Make sure that we always print if asked for explicitly regardless 3013 # of $trace_to_depth . 3014 $explicit_stop = ($single || $was_signal); 3015 3016 # Check to see if we should grab control ($single true, 3017 # trace set appropriately, or we got a signal). 3018 if ( $explicit_stop || ( $trace & 1 ) ) { 3019 $obj->_DB__grab_control(@_); 3020 } ## end if ($single || ($trace... 3021 3022=pod 3023 3024If there's an action to be executed for the line we stopped at, execute it. 3025If there are any preprompt actions, execute those as well. 3026 3027=cut 3028 3029 # If there's an action, do it now. 3030 if ($action) { 3031 $evalarg = $action; 3032 # The &-call is here to ascertain the mutability of @_. 3033 &DB::eval; 3034 } 3035 undef $action; 3036 3037 # Are we nested another level (e.g., did we evaluate a function 3038 # that had a breakpoint in it at the debugger prompt)? 3039 if ( $single || $was_signal ) { 3040 3041 # Yes, go down a level. 3042 local $level = $level + 1; 3043 3044 # Do any pre-prompt actions. 3045 foreach $evalarg (@$pre) { 3046 # The &-call is here to ascertain the mutability of @_. 3047 &DB::eval; 3048 } 3049 3050 # Complain about too much recursion if we passed the limit. 3051 if ($single & 4) { 3052 print $OUT $stack_depth . " levels deep in subroutine calls!\n"; 3053 } 3054 3055 # The line we're currently on. Set $incr to -1 to stay here 3056 # until we get a command that tells us to advance. 3057 $start = $line; 3058 $incr = -1; # for backward motion. 3059 3060 # Tack preprompt debugger actions ahead of any actual input. 3061 @typeahead = ( @$pretype, @typeahead ); 3062 3063=head2 WHERE ARE WE? 3064 3065XXX Relocate this section? 3066 3067The debugger normally shows the line corresponding to the current line of 3068execution. Sometimes, though, we want to see the next line, or to move elsewhere 3069in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables. 3070 3071C<$incr> controls by how many lines the I<current> line should move forward 3072after a command is executed. If set to -1, this indicates that the I<current> 3073line shouldn't change. 3074 3075C<$start> is the I<current> line. It is used for things like knowing where to 3076move forwards or backwards from when doing an C<L> or C<-> command. 3077 3078C<$max> tells the debugger where the last line of the current file is. It's 3079used to terminate loops most often. 3080 3081=head2 THE COMMAND LOOP 3082 3083Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes 3084in two parts: 3085 3086=over 4 3087 3088=item * 3089 3090The outer part of the loop, starting at the C<CMD> label. This loop 3091reads a command and then executes it. 3092 3093=item * 3094 3095The inner part of the loop, starting at the C<PIPE> label. This part 3096is wholly contained inside the C<CMD> block and only executes a command. 3097Used to handle commands running inside a pager. 3098 3099=back 3100 3101So why have two labels to restart the loop? Because sometimes, it's easier to 3102have a command I<generate> another command and then re-execute the loop to do 3103the new command. This is faster, but perhaps a bit more convoluted. 3104 3105=cut 3106 3107 # The big command dispatch loop. It keeps running until the 3108 # user yields up control again. 3109 # 3110 # If we have a terminal for input, and we get something back 3111 # from readline(), keep on processing. 3112 3113 CMD: 3114 while (_DB__read_next_cmd($tid)) 3115 { 3116 3117 share($cmd); 3118 # ... try to execute the input as debugger commands. 3119 3120 # Don't stop running. 3121 $single = 0; 3122 3123 # No signal is active. 3124 $signal = 0; 3125 3126 # Handle continued commands (ending with \): 3127 if ($cmd =~ s/\\\z/\n/) { 3128 $cmd .= DB::readline(" cont: "); 3129 redo CMD; 3130 } 3131 3132=head4 The null command 3133 3134A newline entered by itself means I<re-execute the last command>. We grab the 3135command out of C<$laststep> (where it was recorded previously), and copy it 3136back into C<$cmd> to be executed below. If there wasn't any previous command, 3137we'll do nothing below (no command will match). If there was, we also save it 3138in the command history and fall through to allow the command parsing to pick 3139it up. 3140 3141=cut 3142 3143 # Empty input means repeat the last command. 3144 if ($cmd eq '') { 3145 $cmd = $laststep; 3146 } 3147 chomp($cmd); # get rid of the annoying extra newline 3148 if (length($cmd) >= option_val('HistItemMinLength', 2)) { 3149 push( @hist, $cmd ); 3150 } 3151 push( @truehist, $cmd ); 3152 share(@hist); 3153 share(@truehist); 3154 3155 # This is a restart point for commands that didn't arrive 3156 # via direct user input. It allows us to 'redo PIPE' to 3157 # re-execute command processing without reading a new command. 3158 PIPE: { 3159 _DB__trim_command_and_return_first_component($obj); 3160 3161=head3 COMMAND ALIASES 3162 3163The debugger can create aliases for commands (these are stored in the 3164C<%alias> hash). Before a command is executed, the command loop looks it up 3165in the alias hash and substitutes the contents of the alias for the command, 3166completely replacing it. 3167 3168=cut 3169 3170 # See if there's an alias for the command, and set it up if so. 3171 if ( $alias{$cmd_verb} ) { 3172 3173 # Squelch signal handling; we want to keep control here 3174 # if something goes loco during the alias eval. 3175 local $SIG{__DIE__}; 3176 local $SIG{__WARN__}; 3177 3178 # This is a command, so we eval it in the DEBUGGER's 3179 # scope! Otherwise, we can't see the special debugger 3180 # variables, or get to the debugger's subs. (Well, we 3181 # _could_, but why make it even more complicated?) 3182 eval "\$cmd =~ $alias{$cmd_verb}"; 3183 if ($@) { 3184 local $\ = ''; 3185 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@"; 3186 next CMD; 3187 } 3188 _DB__trim_command_and_return_first_component($obj); 3189 } ## end if ($alias{$cmd_verb}) 3190 3191=head3 MAIN-LINE COMMANDS 3192 3193All of these commands work up to and after the program being debugged has 3194terminated. 3195 3196=head4 C<q> - quit 3197 3198Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't 3199try to execute further, cleaning any restart-related stuff out of the 3200environment, and executing with the last value of C<$?>. 3201 3202=cut 3203 3204 # All of these commands were remapped in perl 5.8.0; 3205 # we send them off to the secondary dispatcher (see below). 3206 $obj->_handle_special_char_cmd_wrapper_commands; 3207 _DB__trim_command_and_return_first_component($obj); 3208 3209 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) { 3210 my $type = $cmd_rec->{t}; 3211 my $val = $cmd_rec->{v}; 3212 if ($type eq 'm') { 3213 $obj->$val(); 3214 } 3215 elsif ($type eq 's') { 3216 $val->($obj); 3217 } 3218 } 3219 3220=head4 C<t> - trace [n] 3221 3222Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.). 3223If level is specified, set C<$trace_to_depth>. 3224 3225=head4 C<S> - list subroutines matching/not matching a pattern 3226 3227Walks through C<%sub>, checking to see whether or not to print the name. 3228 3229=head4 C<X> - list variables in current package 3230 3231Since the C<V> command actually processes this, just change this to the 3232appropriate C<V> command and fall through. 3233 3234=head4 C<V> - list variables 3235 3236Uses C<dumpvar.pl> to dump out the current values for selected variables. 3237 3238=head4 C<x> - evaluate and print an expression 3239 3240Hands the expression off to C<DB::eval>, setting it up to print the value 3241via C<dumpvar.pl> instead of just printing it directly. 3242 3243=head4 C<m> - print methods 3244 3245Just uses C<DB::methods> to determine what methods are available. 3246 3247=head4 C<f> - switch files 3248 3249Switch to a different filename. 3250 3251=head4 C<.> - return to last-executed line. 3252 3253We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead, 3254and then we look up the line in the magical C<%dbline> hash. 3255 3256=head4 C<-> - back one window 3257 3258We change C<$start> to be one window back; if we go back past the first line, 3259we set it to be the first line. We set C<$incr> to put us back at the 3260currently-executing line, and then put a S<C<l $start +>> (list one window from 3261C<$start>) in C<$cmd> to be executed later. 3262 3263=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>> 3264 3265In Perl 5.8.0, a realignment of the commands was done to fix up a number of 3266problems, most notably that the default case of several commands destroying 3267the user's work in setting watchpoints, actions, etc. We wanted, however, to 3268retain the old commands for those who were used to using them or who preferred 3269them. At this point, we check for the new commands and call C<cmd_wrapper> to 3270deal with them instead of processing them in-line. 3271 3272=head4 C<y> - List lexicals in higher scope 3273 3274Uses C<PadWalker> to find the lexicals supplied as arguments in a scope 3275above the current one and then displays them using F<dumpvar.pl>. 3276 3277=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS 3278 3279All of the commands below this point don't work after the program being 3280debugged has ended. All of them check to see if the program has ended; this 3281allows the commands to be relocated without worrying about a 'line of 3282demarcation' above which commands can be entered anytime, and below which 3283they can't. 3284 3285=head4 C<n> - single step, but don't trace down into subs 3286 3287Done by setting C<$single> to 2, which forces subs to execute straight through 3288when entered (see C<DB::sub> in L</DEBUGGER INTERFACE VARIABLES>). We also 3289save the C<n> command in C<$laststep>, 3290 3291so a null command knows what to re-execute. 3292 3293=head4 C<s> - single-step, entering subs 3294 3295Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside 3296subs. Also saves C<s> as C<$lastcmd>. 3297 3298=head4 C<c> - run continuously, setting an optional breakpoint 3299 3300Most of the code for this command is taken up with locating the optional 3301breakpoint, which is either a subroutine name or a line number. We set 3302the appropriate one-time-break in C<@dbline> and then turn off single-stepping 3303in this and all call levels above this one. 3304 3305=head4 C<r> - return from a subroutine 3306 3307For C<r> to work properly, the debugger has to stop execution again 3308immediately after the return is executed. This is done by forcing 3309single-stepping to be on in the call level above the current one. If 3310we are printing return values when a C<r> is executed, set C<$doret> 3311appropriately, and force us out of the command loop. 3312 3313=head4 C<T> - stack trace 3314 3315Just calls C<DB::print_trace>. 3316 3317=head4 C<w> - List window around current line. 3318 3319Just calls C<DB::cmd_w>. 3320 3321=head4 C<W> - watch-expression processing. 3322 3323Just calls C<DB::cmd_W>. 3324 3325=head4 C</> - search forward for a string in the source 3326 3327We take the argument and treat it as a pattern. If it turns out to be a 3328bad one, we return the error we got from trying to C<eval> it and exit. 3329If not, we create some code to do the search and C<eval> it so it can't 3330mess us up. 3331 3332=cut 3333 3334 _DB__handle_forward_slash_command($obj); 3335 3336=head4 C<?> - search backward for a string in the source 3337 3338Same as for C</>, except the loop runs backwards. 3339 3340=cut 3341 3342 _DB__handle_question_mark_command($obj); 3343 3344=head4 C<$rc> - Recall command 3345 3346Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports 3347that the terminal supports history). It finds the command required, puts it 3348into C<$cmd>, and redoes the loop to execute it. 3349 3350=cut 3351 3352 # $rc - recall command. 3353 $obj->_handle_rc_recall_command; 3354 3355=head4 C<$sh$sh> - C<system()> command 3356 3357Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and 3358C<STDOUT> from getting messed up. 3359 3360=cut 3361 3362 $obj->_handle_sh_command; 3363 3364=head4 C<$rc I<pattern> $rc> - Search command history 3365 3366Another command to manipulate C<@hist>: this one searches it with a pattern. 3367If a command is found, it is placed in C<$cmd> and executed via C<redo>. 3368 3369=cut 3370 3371 $obj->_handle_rc_search_history_command; 3372 3373=head4 C<$sh> - Invoke a shell 3374 3375Uses C<_db_system()> to invoke a shell. 3376 3377=cut 3378 3379=head4 C<$sh I<command>> - Force execution of a command in a shell 3380 3381Like the above, but the command is passed to the shell. Again, we use 3382C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>. 3383 3384=head4 C<H> - display commands in history 3385 3386Prints the contents of C<@hist> (if any). 3387 3388=head4 C<man, doc, perldoc> - look up documentation 3389 3390Just calls C<runman()> to print the appropriate document. 3391 3392=cut 3393 3394 $obj->_handle_doc_command; 3395 3396=head4 C<p> - print 3397 3398Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at 3399the bottom of the loop. 3400 3401=head4 C<=> - define command alias 3402 3403Manipulates C<%alias> to add or list command aliases. 3404 3405=head4 C<source> - read commands from a file. 3406 3407Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will 3408pick it up. 3409 3410=head4 C<enable> C<disable> - enable or disable breakpoints 3411 3412This enables or disables breakpoints. 3413 3414=head4 C<save> - send current history to a file 3415 3416Takes the complete history, (not the shrunken version you see with C<H>), 3417and saves it to the given filename, so it can be replayed using C<source>. 3418 3419Note that all C<^(save|source)>'s are commented out with a view to minimise recursion. 3420 3421=head4 C<R> - restart 3422 3423Restart the debugger session. 3424 3425=head4 C<rerun> - rerun the current session 3426 3427Return to any given position in the B<true>-history list 3428 3429=head4 C<|, ||> - pipe output through the pager. 3430 3431For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT> 3432(the program's standard output). For C<||>, we only save C<OUT>. We open a 3433pipe to the pager (restoring the output filehandles if this fails). If this 3434is the C<|> command, we also set up a C<SIGPIPE> handler which will simply 3435set C<$signal>, sending us back into the debugger. 3436 3437We then trim off the pipe symbols and C<redo> the command loop at the 3438C<PIPE> label, causing us to evaluate the command in C<$cmd> without 3439reading another. 3440 3441=cut 3442 3443 # || - run command in the pager, with output to DB::OUT. 3444 _DB__handle_run_command_in_pager_command($obj); 3445 3446=head3 END OF COMMAND PARSING 3447 3448Anything left in C<$cmd> at this point is a Perl expression that we want to 3449evaluate. We'll always evaluate in the user's context, and fully qualify 3450any variables we might want to address in the C<DB> package. 3451 3452=cut 3453 3454 } # PIPE: 3455 3456 # trace an expression 3457 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/; 3458 3459 # Make sure the flag that says "the debugger's running" is 3460 # still on, to make sure we get control again. 3461 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd"; 3462 3463 # Run *our* eval that executes in the caller's context. 3464 # The &-call is here to ascertain the mutability of @_. 3465 &DB::eval; 3466 3467 # Turn off the one-time-dump stuff now. 3468 if ($onetimeDump) { 3469 $onetimeDump = undef; 3470 $onetimedumpDepth = undef; 3471 } 3472 elsif ( $term_pid == $$ ) { 3473 eval { # May run under miniperl, when not available... 3474 STDOUT->flush(); 3475 STDERR->flush(); 3476 }; 3477 3478 # XXX If this is the master pid, print a newline. 3479 print {$OUT} "\n"; 3480 } 3481 } ## end while (($term || &setterm... 3482 3483=head3 POST-COMMAND PROCESSING 3484 3485After each command, we check to see if the command output was piped anywhere. 3486If so, we go through the necessary code to unhook the pipe and go back to 3487our standard filehandles for input and output. 3488 3489=cut 3490 3491 continue { # CMD: 3492 _DB__at_end_of_every_command($obj); 3493 } # CMD: 3494 3495=head3 COMMAND LOOP TERMINATION 3496 3497When commands have finished executing, we come here. If the user closed the 3498input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We 3499evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, 3500C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter. 3501The interpreter will then execute the next line and then return control to us 3502again. 3503 3504=cut 3505 3506 # No more commands? Quit. 3507 unless (defined $cmd) { 3508 DB::Obj::_do_quit(); 3509 } 3510 3511 # Evaluate post-prompt commands. 3512 foreach $evalarg (@$post) { 3513 # The &-call is here to ascertain the mutability of @_. 3514 &DB::eval; 3515 } 3516 } # if ($single || $signal) 3517 3518 # Put the user's globals back where you found them. 3519 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved; 3520 (); 3521} ## end sub DB 3522 3523# Because DB::Obj is used above, 3524# 3525# my $obj = DB::Obj->new( 3526# 3527# The following package declaration must come before that, 3528# or else runtime errors will occur with 3529# 3530# PERLDB_OPTS="autotrace nonstop" 3531# 3532# ( rt#116771 ) 3533BEGIN { 3534 3535package DB::Obj; 3536 3537sub new { 3538 my $class = shift; 3539 3540 my $self = bless {}, $class; 3541 3542 $self->_init(@_); 3543 3544 return $self; 3545} 3546 3547sub _init { 3548 my ($self, $args) = @_; 3549 3550 %{$self} = (%$self, %$args); 3551 3552 return; 3553} 3554 3555{ 3556 no strict 'refs'; 3557 foreach my $slot_name (qw( 3558 after explicit_stop infix pat piped position prefix selected cmd_verb 3559 cmd_args 3560 )) { 3561 my $slot = $slot_name; 3562 *{$slot} = sub { 3563 my $self = shift; 3564 3565 if (@_) { 3566 ${ $self->{$slot} } = shift; 3567 } 3568 3569 return ${ $self->{$slot} }; 3570 }; 3571 3572 *{"append_to_$slot"} = sub { 3573 my $self = shift; 3574 my $s = shift; 3575 3576 return $self->$slot($self->$slot . $s); 3577 }; 3578 } 3579} 3580 3581sub _DB_on_init__initialize_globals 3582{ 3583 my $self = shift; 3584 3585 # Check for whether we should be running continuously or not. 3586 # _After_ the perl program is compiled, $single is set to 1: 3587 if ( $single and not $second_time++ ) { 3588 3589 # Options say run non-stop. Run until we get an interrupt. 3590 if ($runnonstop) { # Disable until signal 3591 # If there's any call stack in place, turn off single 3592 # stepping into subs throughout the stack. 3593 for my $i (0 .. $stack_depth) { 3594 $stack[ $i ] &= ~1; 3595 } 3596 3597 # And we are now no longer in single-step mode. 3598 $single = 0; 3599 3600 # If we simply returned at this point, we wouldn't get 3601 # the trace info. Fall on through. 3602 # return; 3603 } ## end if ($runnonstop) 3604 3605 elsif ($ImmediateStop) { 3606 3607 # We are supposed to stop here; XXX probably a break. 3608 $ImmediateStop = 0; # We've processed it; turn it off 3609 $signal = 1; # Simulate an interrupt to force 3610 # us into the command loop 3611 } 3612 } ## end if ($single and not $second_time... 3613 3614 # If we're in single-step mode, or an interrupt (real or fake) 3615 # has occurred, turn off non-stop mode. 3616 $runnonstop = 0 if $single or $signal; 3617 3618 return; 3619} 3620 3621sub _my_print_lineinfo 3622{ 3623 my ($self, $i, $incr_pos) = @_; 3624 3625 if ($frame) { 3626 # Print it indented if tracing is on. 3627 DB::print_lineinfo( ' ' x $stack_depth, 3628 "$i:\t$DB::dbline[$i]" . $self->after ); 3629 } 3630 else { 3631 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos); 3632 } 3633} 3634 3635sub _curr_line { 3636 return $DB::dbline[$line]; 3637} 3638 3639sub _is_full { 3640 my ($self, $letter) = @_; 3641 3642 return ($DB::cmd eq $letter); 3643} 3644 3645sub _DB__grab_control 3646{ 3647 my $self = shift; 3648 3649 # Yes, grab control. 3650 if ($client_editor) { 3651 3652 # Tell the editor to update its position. 3653 $self->position("$sub_twice${DB::filename}:$line:0\n"); 3654 DB::print_lineinfo($self->position()); 3655 } 3656 3657=pod 3658 3659Special check: if we're in package C<DB::fake>, we've gone through the 3660C<END> block at least once. We set up everything so that we can continue 3661to enter commands and have a valid context to be in. 3662 3663=cut 3664 3665 elsif ( $DB::package eq 'DB::fake' ) { 3666 3667 # Fallen off the end already. 3668 if (!$DB::term) { 3669 DB::setterm(); 3670 } 3671 3672 DB::print_help(<<EOP); 3673Debugged program terminated. Use B<q> to quit or B<R> to restart, 3674use B<o> I<inhibit_exit> to avoid stopping after program termination, 3675S<B<h q>>, S<B<h R>> or S<B<h o>> to get additional info. 3676EOP 3677 3678 $DB::package = 'main'; 3679 $DB::usercontext = DB::_calc_usercontext($DB::package); 3680 } ## end elsif ($package eq 'DB::fake') 3681 3682=pod 3683 3684If the program hasn't finished executing, we scan forward to the 3685next executable line, print that out, build the prompt from the file and line 3686number information, and print that. 3687 3688=cut 3689 3690 else { 3691 3692 3693 # Still somewhere in the midst of execution. Set up the 3694 # debugger prompt. 3695 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to 3696 # Perl 5 ones (sorry, we don't print Klingon 3697 #module names) 3698 3699 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::')); 3700 $self->append_to_prefix( "$DB::sub(${DB::filename}:" ); 3701 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" ); 3702 3703 # Break up the prompt if it's really long. 3704 if ( length($self->prefix()) > 30 ) { 3705 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after); 3706 $self->prefix(""); 3707 $self->infix(":\t"); 3708 } 3709 else { 3710 $self->infix("):\t"); 3711 $self->position( 3712 $self->prefix . $line. $self->infix 3713 . $self->_curr_line . $self->after 3714 ); 3715 } 3716 3717 # Print current line info, indenting if necessary. 3718 $self->_my_print_lineinfo($line, $self->position); 3719 3720 my $i; 3721 my $line_i = sub { return $DB::dbline[$i]; }; 3722 3723 # Scan forward, stopping at either the end or the next 3724 # unbreakable line. 3725 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i ) 3726 { #{ vi 3727 3728 # Drop out on null statements, block closers, and comments. 3729 last if $line_i->() =~ /^\s*[\;\}\#\n]/; 3730 3731 # Drop out if the user interrupted us. 3732 last if $signal; 3733 3734 # Append a newline if the line doesn't have one. Can happen 3735 # in eval'ed text, for instance. 3736 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" ); 3737 3738 # Next executable line. 3739 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->() 3740 . $self->after; 3741 $self->append_to_position($incr_pos); 3742 $self->_my_print_lineinfo($i, $incr_pos); 3743 } ## end for ($i = $line + 1 ; $i... 3744 } ## end else [ if ($client_editor) 3745 3746 return; 3747} 3748 3749sub _handle_t_command { 3750 my $self = shift; 3751 3752 my $levels = $self->cmd_args(); 3753 3754 if ((!length($levels)) or ($levels !~ /\D/)) { 3755 $trace ^= 1; 3756 local $\ = ''; 3757 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9; 3758 print {$OUT} "Trace = " 3759 . ( ( $trace & 1 ) 3760 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" ) 3761 : "off" ) . "\n"; 3762 next CMD; 3763 } 3764 3765 return; 3766} 3767 3768 3769sub _handle_S_command { 3770 my $self = shift; 3771 3772 if (my ($print_all_subs, $should_reverse, $Spatt) 3773 = $self->cmd_args =~ /\A((!)?(.+))?\z/) { 3774 # $Spatt is the pattern (if any) to use. 3775 # Reverse scan? 3776 my $Srev = defined $should_reverse; 3777 # No args - print all subs. 3778 my $Snocheck = !defined $print_all_subs; 3779 3780 # Need to make these sane here. 3781 local $\ = ''; 3782 local $, = ''; 3783 3784 # Search through the debugger's magical hash of subs. 3785 # If $nocheck is true, just print the sub name. 3786 # Otherwise, check it against the pattern. We then use 3787 # the XOR trick to reverse the condition as required. 3788 foreach $subname ( sort( keys %sub ) ) { 3789 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) { 3790 print $OUT $subname, "\n"; 3791 } 3792 } 3793 next CMD; 3794 } 3795 3796 return; 3797} 3798 3799sub _handle_V_command_and_X_command { 3800 my $self = shift; 3801 3802 $DB::cmd =~ s/^X\b/V $DB::package/; 3803 3804 # Bare V commands get the currently-being-debugged package 3805 # added. 3806 if ($self->_is_full('V')) { 3807 $DB::cmd = "V $DB::package"; 3808 } 3809 3810 # V - show variables in package. 3811 if (my ($new_packname, $new_vars_str) = 3812 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) { 3813 3814 # Save the currently selected filehandle and 3815 # force output to debugger's filehandle (dumpvar 3816 # just does "print" for output). 3817 my $savout = select($OUT); 3818 3819 # Grab package name and variables to dump. 3820 $packname = $new_packname; 3821 my @vars = split( ' ', $new_vars_str ); 3822 3823 # If main::dumpvar isn't here, get it. 3824 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; 3825 if ( defined &main::dumpvar ) { 3826 3827 # We got it. Turn off subroutine entry/exit messages 3828 # for the moment, along with return values. 3829 local $frame = 0; 3830 local $doret = -2; 3831 3832 # must detect sigpipe failures - not catching 3833 # then will cause the debugger to die. 3834 eval { 3835 main::dumpvar( 3836 $packname, 3837 defined $option{dumpDepth} 3838 ? $option{dumpDepth} 3839 : -1, # assume -1 unless specified 3840 @vars 3841 ); 3842 }; 3843 3844 # The die doesn't need to include the $@, because 3845 # it will automatically get propagated for us. 3846 if ($@) { 3847 die unless $@ =~ /dumpvar print failed/; 3848 } 3849 } ## end if (defined &main::dumpvar) 3850 else { 3851 3852 # Couldn't load dumpvar. 3853 print $OUT "dumpvar.pl not available.\n"; 3854 } 3855 3856 # Restore the output filehandle, and go round again. 3857 select($savout); 3858 next CMD; 3859 } 3860 3861 return; 3862} 3863 3864sub _handle_dash_command { 3865 my $self = shift; 3866 3867 if ($self->_is_full('-')) { 3868 3869 # back up by a window; go to 1 if back too far. 3870 $start -= $incr + $window + 1; 3871 $start = 1 if $start <= 0; 3872 $incr = $window - 1; 3873 3874 # Generate and execute a "l +" command (handled below). 3875 $DB::cmd = 'l ' . ($start) . '+'; 3876 redo CMD; 3877 } 3878 return; 3879} 3880 3881sub _n_or_s_commands_generic { 3882 my ($self, $new_val) = @_; 3883 # n - next 3884 next CMD if DB::_DB__is_finished(); 3885 3886 # Single step, but don't enter subs. 3887 $single = $new_val; 3888 3889 # Save for empty command (repeat last). 3890 $laststep = $DB::cmd; 3891 last CMD; 3892} 3893 3894sub _n_or_s { 3895 my ($self, $letter, $new_val) = @_; 3896 3897 if ($self->_is_full($letter)) { 3898 $self->_n_or_s_commands_generic($new_val); 3899 } 3900 else { 3901 $self->_n_or_s_and_arg_commands_generic($letter, $new_val); 3902 } 3903 3904 return; 3905} 3906 3907sub _handle_n_command { 3908 my $self = shift; 3909 3910 return $self->_n_or_s('n', 2); 3911} 3912 3913sub _handle_s_command { 3914 my $self = shift; 3915 3916 return $self->_n_or_s('s', 1); 3917} 3918 3919sub _handle_r_command { 3920 my $self = shift; 3921 3922 # r - return from the current subroutine. 3923 if ($self->_is_full('r')) { 3924 3925 # Can't do anything if the program's over. 3926 next CMD if DB::_DB__is_finished(); 3927 3928 # Turn on stack trace. 3929 $stack[$stack_depth] |= 1; 3930 3931 # Print return value unless the stack is empty. 3932 $doret = $option{PrintRet} ? $stack_depth - 1 : -2; 3933 last CMD; 3934 } 3935 3936 return; 3937} 3938 3939sub _handle_T_command { 3940 my $self = shift; 3941 3942 if ($self->_is_full('T')) { 3943 DB::print_trace( $OUT, 1 ); # skip DB 3944 next CMD; 3945 } 3946 3947 return; 3948} 3949 3950sub _handle_w_command { 3951 my $self = shift; 3952 3953 DB::cmd_w( 'w', $self->cmd_args() ); 3954 next CMD; 3955 3956 return; 3957} 3958 3959sub _handle_W_command { 3960 my $self = shift; 3961 3962 if (my $arg = $self->cmd_args) { 3963 DB::cmd_W( 'W', $arg ); 3964 next CMD; 3965 } 3966 3967 return; 3968} 3969 3970sub _handle_rc_recall_command { 3971 my $self = shift; 3972 3973 # $rc - recall command. 3974 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) { 3975 3976 # No arguments, take one thing off history. 3977 pop(@hist) if length($DB::cmd) > 1; 3978 3979 # Relative (- found)? 3980 # Y - index back from most recent (by 1 if bare minus) 3981 # N - go to that particular command slot or the last 3982 # thing if nothing following. 3983 3984 $self->cmd_verb( 3985 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist )) 3986 ); 3987 3988 # Pick out the command desired. 3989 $DB::cmd = $hist[$self->cmd_verb]; 3990 3991 # Print the command to be executed and restart the loop 3992 # with that command in the buffer. 3993 print {$OUT} $DB::cmd, "\n"; 3994 redo CMD; 3995 } 3996 3997 return; 3998} 3999 4000sub _handle_rc_search_history_command { 4001 my $self = shift; 4002 4003 # $rc pattern $rc - find a command in the history. 4004 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) { 4005 4006 # Create the pattern to use. 4007 my $pat = "^$arg"; 4008 $self->pat($pat); 4009 4010 # Toss off last entry if length is >1 (and it always is). 4011 pop(@hist) if length($DB::cmd) > 1; 4012 4013 my $i; 4014 4015 # Look backward through the history. 4016 SEARCH_HIST: 4017 for ( $i = $#hist ; $i ; --$i ) { 4018 # Stop if we find it. 4019 last SEARCH_HIST if $hist[$i] =~ /$pat/; 4020 } 4021 4022 if ( !$i ) { 4023 4024 # Never found it. 4025 print $OUT "No such command!\n\n"; 4026 next CMD; 4027 } 4028 4029 # Found it. Put it in the buffer, print it, and process it. 4030 $DB::cmd = $hist[$i]; 4031 print $OUT $DB::cmd, "\n"; 4032 redo CMD; 4033 } 4034 4035 return; 4036} 4037 4038sub _handle_H_command { 4039 my $self = shift; 4040 4041 if ($self->cmd_args =~ m#\A\*#) { 4042 @hist = @truehist = (); 4043 print $OUT "History cleansed\n"; 4044 next CMD; 4045 } 4046 4047 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) { 4048 4049 # Anything other than negative numbers is ignored by 4050 # the (incorrect) pattern, so this test does nothing. 4051 $end = $num ? ( $#hist - $num ) : 0; 4052 4053 # Set to the minimum if less than zero. 4054 $hist = 0 if $hist < 0; 4055 4056 # Start at the end of the array. 4057 # Stay in while we're still above the ending value. 4058 # Tick back by one each time around the loop. 4059 my $i; 4060 4061 for ( $i = $#hist ; $i > $end ; $i-- ) { 4062 print $OUT "$i: ", $hist[$i], "\n"; 4063 } 4064 4065 next CMD; 4066 } 4067 4068 return; 4069} 4070 4071sub _handle_doc_command { 4072 my $self = shift; 4073 4074 # man, perldoc, doc - show manual pages. 4075 if (my ($man_page) 4076 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) { 4077 DB::runman($man_page); 4078 next CMD; 4079 } 4080 4081 return; 4082} 4083 4084sub _handle_p_command { 4085 my $self = shift; 4086 4087 my $print_cmd = 'print {$DB::OUT} '; 4088 # p - print (no args): print $_. 4089 if ($self->_is_full('p')) { 4090 $DB::cmd = $print_cmd . '$_'; 4091 } 4092 else { 4093 # p - print the given expression. 4094 $DB::cmd =~ s/\Ap\b/$print_cmd /; 4095 } 4096 4097 return; 4098} 4099 4100sub _handle_equal_sign_command { 4101 my $self = shift; 4102 4103 if ($DB::cmd =~ s/\A=\s*//) { 4104 my @keys; 4105 if ( length $DB::cmd == 0 ) { 4106 4107 # No args, get current aliases. 4108 @keys = sort keys %alias; 4109 } 4110 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) { 4111 4112 # Creating a new alias. $k is alias name, $v is 4113 # alias value. 4114 4115 # can't use $_ or kill //g state 4116 for my $x ( $k, $v ) { 4117 4118 # Escape "alarm" characters. 4119 $x =~ s/\a/\\a/g; 4120 } 4121 4122 # Substitute key for value, using alarm chars 4123 # as separators (which is why we escaped them in 4124 # the command). 4125 $alias{$k} = "s\a$k\a$v\a"; 4126 4127 # Turn off standard warn and die behavior. 4128 local $SIG{__DIE__}; 4129 local $SIG{__WARN__}; 4130 4131 # Is it valid Perl? 4132 unless ( eval "sub { s\a$k\a$v\a }; 1" ) { 4133 4134 # Nope. Bad alias. Say so and get out. 4135 print $OUT "Can't alias $k to $v: $@\n"; 4136 delete $alias{$k}; 4137 next CMD; 4138 } 4139 4140 # We'll only list the new one. 4141 @keys = ($k); 4142 } ## end elsif (my ($k, $v) = ($DB::cmd... 4143 4144 # The argument is the alias to list. 4145 else { 4146 @keys = ($DB::cmd); 4147 } 4148 4149 # List aliases. 4150 for my $k (@keys) { 4151 4152 # Messy metaquoting: Trim the substitution code off. 4153 # We use control-G as the delimiter because it's not 4154 # likely to appear in the alias. 4155 if ( ( my $v = $alias{$k} ) =~ ss\a$k\a(.*)\a$1 ) { 4156 4157 # Print the alias. 4158 print $OUT "$k\t= $1\n"; 4159 } 4160 elsif ( defined $alias{$k} ) { 4161 4162 # Couldn't trim it off; just print the alias code. 4163 print $OUT "$k\t$alias{$k}\n"; 4164 } 4165 else { 4166 4167 # No such, dude. 4168 print "No alias for $k\n"; 4169 } 4170 } ## end for my $k (@keys) 4171 next CMD; 4172 } 4173 4174 return; 4175} 4176 4177sub _handle_source_command { 4178 my $self = shift; 4179 4180 # source - read commands from a file (or pipe!) and execute. 4181 if (my $sourced_fn = $self->cmd_args) { 4182 if ( open my $fh, $sourced_fn ) { 4183 4184 # Opened OK; stick it in the list of file handles. 4185 push @cmdfhs, $fh; 4186 } 4187 else { 4188 4189 # Couldn't open it. 4190 DB::_db_warn("Can't execute '$sourced_fn': $!\n"); 4191 } 4192 next CMD; 4193 } 4194 4195 return; 4196} 4197 4198sub _handle_enable_disable_commands { 4199 my $self = shift; 4200 4201 my $which_cmd = $self->cmd_verb; 4202 my $position = $self->cmd_args; 4203 4204 if ($position !~ /\s/) { 4205 my ($fn, $line_num); 4206 if ($position =~ m{\A\d+\z}) 4207 { 4208 $fn = $DB::filename; 4209 $line_num = $position; 4210 } 4211 elsif (my ($new_fn, $new_line_num) 4212 = $position =~ m{\A(.*):(\d+)\z}) { 4213 ($fn, $line_num) = ($new_fn, $new_line_num); 4214 } 4215 else 4216 { 4217 DB::_db_warn("Wrong spec for enable/disable argument.\n"); 4218 } 4219 4220 if (defined($fn)) { 4221 if (DB::_has_breakpoint_data_ref($fn, $line_num)) { 4222 DB::_set_breakpoint_enabled_status($fn, $line_num, 4223 ($which_cmd eq 'enable' ? 1 : '') 4224 ); 4225 } 4226 else { 4227 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n"); 4228 } 4229 } 4230 4231 next CMD; 4232 } 4233 4234 return; 4235} 4236 4237sub _handle_save_command { 4238 my $self = shift; 4239 4240 if (my $new_fn = $self->cmd_args) { 4241 my $filename = $new_fn || '.perl5dbrc'; # default? 4242 if ( open my $fh, '>', $filename ) { 4243 4244 # chomp to remove extraneous newlines from source'd files 4245 chomp( my @truelist = 4246 map { m/\A\s*(save|source)/ ? "#$_" : $_ } 4247 @truehist ); 4248 print {$fh} join( "\n", @truelist ); 4249 print "commands saved in $filename\n"; 4250 } 4251 else { 4252 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n"); 4253 } 4254 next CMD; 4255 } 4256 4257 return; 4258} 4259 4260sub _n_or_s_and_arg_commands_generic { 4261 my ($self, $letter, $new_val) = @_; 4262 4263 # s - single-step. Remember the last command was 's'. 4264 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) { 4265 $laststep = $letter; 4266 } 4267 4268 return; 4269} 4270 4271sub _handle_sh_command { 4272 my $self = shift; 4273 4274 # $sh$sh - run a shell command (if it's all ASCII). 4275 # Can't run shell commands with Unicode in the debugger, hmm. 4276 my $my_cmd = $DB::cmd; 4277 if ($my_cmd =~ m#\A$sh#gms) { 4278 4279 if ($my_cmd =~ m#\G\z#cgms) { 4280 # Run the user's shell. If none defined, run Bourne. 4281 # We resume execution when the shell terminates. 4282 DB::_db_system( $ENV{SHELL} || "/bin/sh" ); 4283 next CMD; 4284 } 4285 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) { 4286 # System it. 4287 DB::_db_system($1); 4288 next CMD; 4289 } 4290 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) { 4291 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 ); 4292 next CMD; 4293 } 4294 } 4295} 4296 4297sub _handle_x_command { 4298 my $self = shift; 4299 4300 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval() 4301 $onetimeDump = 'dump'; # main::dumpvar shows the output 4302 4303 # handle special "x 3 blah" syntax XXX propagate 4304 # doc back to special variables. 4305 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) { 4306 $onetimedumpDepth = $1; 4307 } 4308 } 4309 4310 return; 4311} 4312 4313sub _do_quit { 4314 $fall_off_end = 1; 4315 DB::clean_ENV(); 4316 exit $?; 4317} 4318 4319sub _handle_q_command { 4320 my $self = shift; 4321 4322 if ($self->_is_full('q')) { 4323 _do_quit(); 4324 } 4325 4326 return; 4327} 4328 4329sub _handle_cmd_wrapper_commands { 4330 my $self = shift; 4331 4332 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line ); 4333 next CMD; 4334} 4335 4336sub _handle_special_char_cmd_wrapper_commands { 4337 my $self = shift; 4338 4339 # All of these commands were remapped in perl 5.8.0; 4340 # we send them off to the secondary dispatcher (see below). 4341 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) { 4342 DB::cmd_wrapper( $cmd_letter, $my_arg, $line ); 4343 next CMD; 4344 } 4345 4346 return; 4347} 4348 4349} ## end DB::Obj 4350 4351package DB; 4352 4353# The following code may be executed now: 4354# BEGIN {warn 4} 4355 4356=head2 sub 4357 4358C<sub> is called whenever a subroutine call happens in the program being 4359debugged. The variable C<$DB::sub> contains the name of the subroutine 4360being called. 4361 4362The core function of this subroutine is to actually call the sub in the proper 4363context, capturing its output. This of course causes C<DB::DB> to get called 4364again, repeating until the subroutine ends and returns control to C<DB::sub> 4365again. Once control returns, C<DB::sub> figures out whether or not to dump the 4366return value, and returns its captured copy of the return value as its own 4367return value. The value then feeds back into the program being debugged as if 4368C<DB::sub> hadn't been there at all. 4369 4370C<sub> does all the work of printing the subroutine entry and exit messages 4371enabled by setting C<$frame>. It notes what sub the autoloader got called for, 4372and also prints the return value if needed (for the C<r> command and if 4373the 16 bit is set in C<$frame>). 4374 4375It also tracks the subroutine call depth by saving the current setting of 4376C<$single> in the C<@stack> package global; if this exceeds the value in 4377C<$deep>, C<sub> automatically turns on printing of the current depth by 4378setting the C<4> bit in C<$single>. In any case, it keeps the current setting 4379of stop/don't stop on entry to subs set as it currently is set. 4380 4381=head3 C<caller()> support 4382 4383If C<caller()> is called from the package C<DB>, it provides some 4384additional data, in the following order: 4385 4386=over 4 4387 4388=item * C<$package> 4389 4390The package name the sub was in 4391 4392=item * C<$filename> 4393 4394The filename it was defined in 4395 4396=item * C<$line> 4397 4398The line number it was defined on 4399 4400=item * C<$subroutine> 4401 4402The subroutine name; C<(eval)> if an C<eval>(). 4403 4404=item * C<$hasargs> 4405 44061 if it has arguments, 0 if not 4407 4408=item * C<$wantarray> 4409 44101 if array context, 0 if scalar context 4411 4412=item * C<$evaltext> 4413 4414The C<eval>() text, if any (undefined for S<C<eval BLOCK>>) 4415 4416=item * C<$is_require> 4417 4418frame was created by a C<use> or C<require> statement 4419 4420=item * C<$hints> 4421 4422pragma information; subject to change between versions 4423 4424=item * C<$bitmask> 4425 4426pragma information; subject to change between versions 4427 4428=item * C<@DB::args> 4429 4430arguments with which the subroutine was invoked 4431 4432=back 4433 4434=cut 4435 4436use vars qw($deep); 4437 4438# We need to fully qualify the name ("DB::sub") to make "use strict;" 4439# happy. -- Shlomi Fish 4440 4441sub _indent_print_line_info { 4442 my ($offset, $str) = @_; 4443 4444 print_lineinfo( ' ' x ($stack_depth - $offset), $str); 4445 4446 return; 4447} 4448 4449sub _print_frame_message { 4450 my ($al) = @_; 4451 4452 if ($frame) { 4453 if ($frame & 4) { # Extended frame entry message 4454 _indent_print_line_info(-1, "in "); 4455 4456 # Why -1? But it works! :-( 4457 # Because print_trace will call add 1 to it and then call 4458 # dump_trace; this results in our skipping -1+1 = 0 stack frames 4459 # in dump_trace. 4460 # 4461 # Now it's 0 because we extracted a function. 4462 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" ); 4463 } 4464 else { 4465 _indent_print_line_info(-1, "entering $sub$al\n" ); 4466 } 4467 } 4468 4469 return; 4470} 4471 4472sub DB::sub { 4473 my ( $al, $ret, @ret ) = ""; 4474 4475 # We stack the stack pointer and then increment it to protect us 4476 # from a situation that might unwind a whole bunch of call frames 4477 # at once. Localizing the stack pointer means that it will automatically 4478 # unwind the same amount when multiple stack frames are unwound. 4479 local $stack_depth = $stack_depth + 1; # Protect from non-local exits 4480 4481 { 4482 # lock ourselves under threads 4483 # While lock() permits recursive locks, there's two cases where it's bad 4484 # that we keep a hold on the lock while we call the sub: 4485 # - during cloning, Package::CLONE might be called in the context of the new 4486 # thread, which will deadlock if we hold the lock across the threads::new call 4487 # - for any function that waits any significant time 4488 # This also deadlocks if the parent thread joins(), since holding the lock 4489 # will prevent any child threads passing this point. 4490 # So release the lock for the function call. 4491 lock($DBGR); 4492 4493 # Whether or not the autoloader was running, a scalar to put the 4494 # sub's return value in (if needed), and an array to put the sub's 4495 # return value in (if needed). 4496 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) { 4497 print "creating new thread\n"; 4498 } 4499 4500 # If the last ten characters are '::AUTOLOAD', note we've traced 4501 # into AUTOLOAD for $sub. 4502 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { 4503 no strict 'refs'; 4504 $al = " for $$sub" if defined $$sub; 4505 } 4506 4507 # Expand @stack. 4508 $#stack = $stack_depth; 4509 4510 # Save current single-step setting. 4511 $stack[-1] = $single; 4512 4513 # Turn off all flags except single-stepping. 4514 $single &= 1; 4515 4516 # If we've gotten really deeply recursed, turn on the flag that will 4517 # make us stop with the 'deep recursion' message. 4518 $single |= 4 if $stack_depth == $deep; 4519 4520 # If frame messages are on ... 4521 4522 _print_frame_message($al); 4523 } 4524 4525 # Determine the sub's return type, and capture appropriately. 4526 if (wantarray) { 4527 4528 # Called in array context. call sub and capture output. 4529 # DB::DB will recursively get control again if appropriate; we'll come 4530 # back here when the sub is finished. 4531 no strict 'refs'; 4532 @ret = &$sub; 4533 } 4534 elsif ( defined wantarray ) { 4535 no strict 'refs'; 4536 # Save the value if it's wanted at all. 4537 $ret = &$sub; 4538 } 4539 else { 4540 no strict 'refs'; 4541 # Void return, explicitly. 4542 &$sub; 4543 undef $ret; 4544 } 4545 4546 { 4547 lock($DBGR); 4548 4549 # Pop the single-step value back off the stack. 4550 $single |= $stack[ $stack_depth-- ]; 4551 4552 if ($frame & 2) { 4553 if ($frame & 4) { # Extended exit message 4554 _indent_print_line_info(0, "out "); 4555 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ); 4556 } 4557 else { 4558 _indent_print_line_info(0, "exited $sub$al\n" ); 4559 } 4560 } 4561 4562 if (wantarray) { 4563 # Print the return info if we need to. 4564 if ( $doret eq $stack_depth or $frame & 16 ) { 4565 4566 # Turn off output record separator. 4567 local $\ = ''; 4568 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 4569 4570 # Indent if we're printing because of $frame tracing. 4571 if ($frame & 16) 4572 { 4573 print {$fh} ' ' x $stack_depth; 4574 } 4575 4576 # Print the return value. 4577 print {$fh} "list context return from $sub:\n"; 4578 dumpit( $fh, \@ret ); 4579 4580 # And don't print it again. 4581 $doret = -2; 4582 } ## end if ($doret eq $stack_depth... 4583 # And we have to return the return value now. 4584 @ret; 4585 } ## end if (wantarray) 4586 # Scalar context. 4587 else { 4588 # If we are supposed to show the return value... same as before. 4589 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) { 4590 local $\ = ''; 4591 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 4592 print $fh ( ' ' x $stack_depth ) if $frame & 16; 4593 print $fh ( 4594 defined wantarray 4595 ? "scalar context return from $sub: " 4596 : "void context return from $sub\n" 4597 ); 4598 dumpit( $fh, $ret ) if defined wantarray; 4599 $doret = -2; 4600 } ## end if ($doret eq $stack_depth... 4601 4602 # Return the appropriate scalar value. 4603 $ret; 4604 } ## end else [ if (wantarray) 4605 } 4606} ## end sub _sub 4607 4608sub lsub : lvalue { 4609 4610 # We stack the stack pointer and then increment it to protect us 4611 # from a situation that might unwind a whole bunch of call frames 4612 # at once. Localizing the stack pointer means that it will automatically 4613 # unwind the same amount when multiple stack frames are unwound. 4614 local $stack_depth = $stack_depth + 1; # Protect from non-local exits 4615 4616 # Expand @stack. 4617 $#stack = $stack_depth; 4618 4619 # Save current single-step setting. 4620 $stack[-1] = $single; 4621 4622 # Turn off all flags except single-stepping. 4623 # Use local so the single-step value is popped back off the 4624 # stack for us. 4625 local $single = $single & 1; 4626 4627 no strict 'refs'; 4628 { 4629 # lock ourselves under threads 4630 lock($DBGR); 4631 4632 # Whether or not the autoloader was running, a scalar to put the 4633 # sub's return value in (if needed), and an array to put the sub's 4634 # return value in (if needed). 4635 my ( $al, $ret, @ret ) = ""; 4636 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) { 4637 print "creating new thread\n"; 4638 } 4639 4640 # If the last ten characters are C'::AUTOLOAD', note we've traced 4641 # into AUTOLOAD for $sub. 4642 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { 4643 $al = " for $$sub"; 4644 } 4645 4646 # If we've gotten really deeply recursed, turn on the flag that will 4647 # make us stop with the 'deep recursion' message. 4648 $single |= 4 if $stack_depth == $deep; 4649 4650 # If frame messages are on ... 4651 _print_frame_message($al); 4652 } 4653 4654 # call the original lvalue sub. 4655 &$sub; 4656} 4657 4658# Abstracting common code from multiple places elsewhere: 4659sub depth_print_lineinfo { 4660 my $always_print = shift; 4661 4662 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth); 4663} 4664 4665=head1 EXTENDED COMMAND HANDLING AND THE COMMAND API 4666 4667In Perl 5.8.0, there was a major realignment of the commands and what they did, 4668Most of the changes were to systematize the command structure and to eliminate 4669commands that threw away user input without checking. 4670 4671The following sections describe the code added to make it easy to support 4672multiple command sets with conflicting command names. This section is a start 4673at unifying all command processing to make it simpler to develop commands. 4674 4675Note that all the cmd_[a-zA-Z] subroutines require the command name, a line 4676number, and C<$dbline> (the current line) as arguments. 4677 4678Support functions in this section which have multiple modes of failure C<die> 4679on error; the rest simply return a false value. 4680 4681The user-interface functions (all of the C<cmd_*> functions) just output 4682error messages. 4683 4684=head2 C<%set> 4685 4686The C<%set> hash defines the mapping from command letter to subroutine 4687name suffix. 4688 4689C<%set> is a two-level hash, indexed by set name and then by command name. 4690Note that trying to set the CommandSet to C<foobar> simply results in the 46915.8.0 command set being used, since there's no top-level entry for C<foobar>. 4692 4693=cut 4694 4695### The API section 4696 4697my %set = ( # 4698 'pre580' => { 4699 'a' => 'pre580_a', 4700 'A' => 'pre580_null', 4701 'b' => 'pre580_b', 4702 'B' => 'pre580_null', 4703 'd' => 'pre580_null', 4704 'D' => 'pre580_D', 4705 'h' => 'pre580_h', 4706 'M' => 'pre580_null', 4707 'O' => 'o', 4708 'o' => 'pre580_null', 4709 'v' => 'M', 4710 'w' => 'v', 4711 'W' => 'pre580_W', 4712 }, 4713 'pre590' => { 4714 '<' => 'pre590_prepost', 4715 '<<' => 'pre590_prepost', 4716 '>' => 'pre590_prepost', 4717 '>>' => 'pre590_prepost', 4718 '{' => 'pre590_prepost', 4719 '{{' => 'pre590_prepost', 4720 }, 4721); 4722 4723my %breakpoints_data; 4724 4725sub _has_breakpoint_data_ref { 4726 my ($filename, $line) = @_; 4727 4728 return ( 4729 exists( $breakpoints_data{$filename} ) 4730 and 4731 exists( $breakpoints_data{$filename}{$line} ) 4732 ); 4733} 4734 4735sub _get_breakpoint_data_ref { 4736 my ($filename, $line) = @_; 4737 4738 return ($breakpoints_data{$filename}{$line} ||= +{}); 4739} 4740 4741sub _delete_breakpoint_data_ref { 4742 my ($filename, $line) = @_; 4743 4744 delete($breakpoints_data{$filename}{$line}); 4745 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) { 4746 delete($breakpoints_data{$filename}); 4747 } 4748 4749 return; 4750} 4751 4752sub _set_breakpoint_enabled_status { 4753 my ($filename, $line, $status) = @_; 4754 4755 _get_breakpoint_data_ref($filename, $line)->{'enabled'} = 4756 ($status ? 1 : '') 4757 ; 4758 4759 return; 4760} 4761 4762sub _enable_breakpoint_temp_enabled_status { 4763 my ($filename, $line) = @_; 4764 4765 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1; 4766 4767 return; 4768} 4769 4770sub _cancel_breakpoint_temp_enabled_status { 4771 my ($filename, $line) = @_; 4772 4773 my $ref = _get_breakpoint_data_ref($filename, $line); 4774 4775 delete ($ref->{'temp_enabled'}); 4776 4777 if (! %$ref) { 4778 _delete_breakpoint_data_ref($filename, $line); 4779 } 4780 4781 return; 4782} 4783 4784sub _is_breakpoint_enabled { 4785 my ($filename, $line) = @_; 4786 4787 my $data_ref = _get_breakpoint_data_ref($filename, $line); 4788 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'}); 4789} 4790 4791=head2 C<cmd_wrapper()> (API) 4792 4793C<cmd_wrapper()> allows the debugger to switch command sets 4794depending on the value of the C<CommandSet> option. 4795 4796It tries to look up the command in the C<%set> package-level I<lexical> 4797(which means external entities can't fiddle with it) and create the name of 4798the sub to call based on the value found in the hash (if it's there). I<All> 4799of the commands to be handled in a set have to be added to C<%set>; if they 4800aren't found, the 5.8.0 equivalent is called (if there is one). 4801 4802This code uses symbolic references. 4803 4804=cut 4805 4806sub cmd_wrapper { 4807 my $cmd = shift; 4808 my $line = shift; 4809 my $dblineno = shift; 4810 4811 # Assemble the command subroutine's name by looking up the 4812 # command set and command name in %set. If we can't find it, 4813 # default to the older version of the command. 4814 my $call = 'cmd_' 4815 . ( $set{$CommandSet}{$cmd} 4816 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) ); 4817 4818 # Call the command subroutine, call it by name. 4819 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno ); 4820} ## end sub cmd_wrapper 4821 4822=head3 C<cmd_a> (command) 4823 4824The C<a> command handles pre-execution actions. These are associated with a 4825particular line, so they're stored in C<%dbline>. We default to the current 4826line if none is specified. 4827 4828=cut 4829 4830sub cmd_a { 4831 my $cmd = shift; 4832 my $line = shift || ''; # [.|line] expr 4833 my $dbline = shift; 4834 4835 # If it's dot (here), or not all digits, use the current line. 4836 $line =~ s/\A\./$dbline/; 4837 4838 # Should be a line number followed by an expression. 4839 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) { 4840 4841 if (! length($lineno)) { 4842 $lineno = $dbline; 4843 } 4844 4845 # If we have an expression ... 4846 if ( length $expr ) { 4847 4848 # ... but the line isn't breakable, complain. 4849 if ( $dbline[$lineno] == 0 ) { 4850 print $OUT 4851 "Line $lineno($dbline[$lineno]) does not have an action?\n"; 4852 } 4853 else { 4854 4855 # It's executable. Record that the line has an action. 4856 $had_breakpoints{$filename} |= 2; 4857 4858 # Remove any action, temp breakpoint, etc. 4859 $dbline{$lineno} =~ s/\0[^\0]*//; 4860 4861 # Add the action to the line. 4862 $dbline{$lineno} .= "\0" . action($expr); 4863 4864 _set_breakpoint_enabled_status($filename, $lineno, 1); 4865 } 4866 } ## end if (length $expr) 4867 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/) 4868 else { 4869 4870 # Syntax wrong. 4871 print $OUT 4872 "Adding an action requires an optional lineno and an expression\n" 4873 ; # hint 4874 } 4875} ## end sub cmd_a 4876 4877=head3 C<cmd_A> (command) 4878 4879Delete actions. Similar to above, except the delete code is in a separate 4880subroutine, C<delete_action>. 4881 4882=cut 4883 4884sub cmd_A { 4885 my $cmd = shift; 4886 my $line = shift || ''; 4887 my $dbline = shift; 4888 4889 # Dot is this line. 4890 $line =~ s/^\./$dbline/; 4891 4892 # Call delete_action with a null param to delete them all. 4893 # The '1' forces the eval to be true. It'll be false only 4894 # if delete_action blows up for some reason, in which case 4895 # we print $@ and get out. 4896 if ( $line eq '*' ) { 4897 if (! eval { _delete_all_actions(); 1 }) { 4898 print {$OUT} $@; 4899 return; 4900 } 4901 } 4902 4903 # There's a real line number. Pass it to delete_action. 4904 # Error trapping is as above. 4905 elsif ( $line =~ /^(\S.*)/ ) { 4906 if (! eval { delete_action($1); 1 }) { 4907 print {$OUT} $@; 4908 return; 4909 } 4910 } 4911 4912 # Swing and a miss. Bad syntax. 4913 else { 4914 print $OUT 4915 "Deleting an action requires a line number, or '*' for all\n" ; # hint 4916 } 4917} ## end sub cmd_A 4918 4919=head3 C<delete_action> (API) 4920 4921C<delete_action> accepts either a line number or C<undef>. If a line number 4922is specified, we check for the line being executable (if it's not, it 4923couldn't have had an action). If it is, we just take the action off (this 4924will get any kind of an action, including breakpoints). 4925 4926=cut 4927 4928sub _remove_action_from_dbline { 4929 my $i = shift; 4930 4931 $dbline{$i} =~ s/\0[^\0]*//; # \^a 4932 delete $dbline{$i} if $dbline{$i} eq ''; 4933 4934 return; 4935} 4936 4937sub _delete_all_actions { 4938 print {$OUT} "Deleting all actions...\n"; 4939 4940 for my $file ( keys %had_breakpoints ) { 4941 local *dbline = $main::{ '_<' . $file }; 4942 $max = $#dbline; 4943 my $was; 4944 for my $i (1 .. $max) { 4945 if ( defined $dbline{$i} ) { 4946 _remove_action_from_dbline($i); 4947 } 4948 } 4949 4950 unless ( $had_breakpoints{$file} &= ~2 ) { 4951 delete $had_breakpoints{$file}; 4952 } 4953 } 4954 4955 return; 4956} 4957 4958sub delete_action { 4959 my $i = shift; 4960 4961 if ( defined($i) ) { 4962 # Can there be one? 4963 die "Line $i has no action .\n" if $dbline[$i] == 0; 4964 4965 # Nuke whatever's there. 4966 _remove_action_from_dbline($i); 4967 } 4968 else { 4969 _delete_all_actions(); 4970 } 4971} 4972 4973=head3 C<cmd_b> (command) 4974 4975Set breakpoints. Since breakpoints can be set in so many places, in so many 4976ways, conditionally or not, the breakpoint code is kind of complex. Mostly, 4977we try to parse the command type, and then shuttle it off to an appropriate 4978subroutine to actually do the work of setting the breakpoint in the right 4979place. 4980 4981=cut 4982 4983sub cmd_b { 4984 my $cmd = shift; 4985 my $line = shift; # [.|line] [cond] 4986 my $dbline = shift; 4987 4988 my $default_cond = sub { 4989 my $cond = shift; 4990 return length($cond) ? $cond : '1'; 4991 }; 4992 4993 # Make . the current line number if it's there.. 4994 $line =~ s/^\.(\s|\z)/$dbline$1/; 4995 4996 # No line number, no condition. Simple break on current line. 4997 if ( $line =~ /^\s*$/ ) { 4998 cmd_b_line( $dbline, 1 ); 4999 } 5000 5001 # Break on load for a file. 5002 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) { 5003 $file =~ s/\s+\z//; 5004 cmd_b_load($file); 5005 } 5006 5007 # b compile|postpone <some sub> [<condition>] 5008 # The interpreter actually traps this one for us; we just put the 5009 # necessary condition in the %postponed hash. 5010 elsif ( my ($action, $subname, $cond) 5011 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { 5012 5013 # De-Perl4-ify the name - ' separators to ::. 5014 $subname =~ s/'/::/g; 5015 5016 # Qualify it into the current package unless it's already qualified. 5017 $subname = "${package}::" . $subname unless $subname =~ /::/; 5018 5019 # Add main if it starts with ::. 5020 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 5021 5022 # Save the break type for this sub. 5023 $postponed{$subname} = (($action eq 'postpone') 5024 ? ( "break +0 if " . $default_cond->($cond) ) 5025 : "compile"); 5026 } ## end elsif ($line =~ ... 5027 # b <filename>:<line> [<condition>] 5028 elsif (my ($filename, $line_num, $cond) 5029 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) { 5030 cmd_b_filename_line( 5031 $filename, 5032 $line_num, 5033 (length($cond) ? $cond : '1'), 5034 ); 5035 } 5036 # b <sub name> [<condition>] 5037 elsif ( my ($new_subname, $new_cond) = 5038 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { 5039 5040 # 5041 $subname = $new_subname; 5042 cmd_b_sub( $subname, $default_cond->($new_cond) ); 5043 } 5044 5045 # b <line> [<condition>]. 5046 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) { 5047 5048 # Capture the line. If none, it's the current line. 5049 $line = $line_n || $dbline; 5050 5051 # Break on line. 5052 cmd_b_line( $line, $default_cond->($cond) ); 5053 } 5054 5055 # Line didn't make sense. 5056 else { 5057 print "confused by line($line)?\n"; 5058 } 5059 5060 return; 5061} ## end sub cmd_b 5062 5063=head3 C<break_on_load> (API) 5064 5065We want to break when this file is loaded. Mark this file in the 5066C<%break_on_load> hash, and note that it has a breakpoint in 5067C<%had_breakpoints>. 5068 5069=cut 5070 5071sub break_on_load { 5072 my $file = shift; 5073 $break_on_load{$file} = 1; 5074 $had_breakpoints{$file} |= 1; 5075} 5076 5077=head3 C<report_break_on_load> (API) 5078 5079Gives us an array of filenames that are set to break on load. Note that 5080only files with break-on-load are in here, so simply showing the keys 5081suffices. 5082 5083=cut 5084 5085sub report_break_on_load { 5086 sort keys %break_on_load; 5087} 5088 5089=head3 C<cmd_b_load> (command) 5090 5091We take the file passed in and try to find it in C<%INC> (which maps modules 5092to files they came from). We mark those files for break-on-load via 5093C<break_on_load> and then report that it was done. 5094 5095=cut 5096 5097sub cmd_b_load { 5098 my $file = shift; 5099 my @files; 5100 5101 # This is a block because that way we can use a redo inside it 5102 # even without there being any looping structure at all outside it. 5103 { 5104 5105 # Save short name and full path if found. 5106 push @files, $file; 5107 push @files, $::INC{$file} if $::INC{$file}; 5108 5109 # Tack on .pm and do it again unless there was a '.' in the name 5110 # already. 5111 $file .= '.pm', redo unless $file =~ /\./; 5112 } 5113 5114 # Do the real work here. 5115 break_on_load($_) for @files; 5116 5117 # All the files that have break-on-load breakpoints. 5118 @files = report_break_on_load; 5119 5120 # Normalize for the purposes of our printing this. 5121 local $\ = ''; 5122 local $" = ' '; 5123 print $OUT "Will stop on load of '@files'.\n"; 5124} ## end sub cmd_b_load 5125 5126=head3 C<$filename_error> (API package global) 5127 5128Several of the functions we need to implement in the API need to work both 5129on the current file and on other files. We don't want to duplicate code, so 5130C<$filename_error> is used to contain the name of the file that's being 5131worked on (if it's not the current one). 5132 5133We can now build functions in pairs: the basic function works on the current 5134file, and uses C<$filename_error> as part of its error message. Since this is 5135initialized to C<"">, no filename will appear when we are working on the 5136current file. 5137 5138The second function is a wrapper which does the following: 5139 5140=over 4 5141 5142=item * 5143 5144Localizes C<$filename_error> and sets it to the name of the file to be processed. 5145 5146=item * 5147 5148Localizes the C<*dbline> glob and reassigns it to point to the file we want to process. 5149 5150=item * 5151 5152Calls the first function. 5153 5154The first function works on the I<current> file (i.e., the one we changed to), 5155and prints C<$filename_error> in the error message (the name of the other file) 5156if it needs to. When the functions return, C<*dbline> is restored to point 5157to the actual current file (the one we're executing in) and 5158C<$filename_error> is restored to C<"">. This restores everything to 5159the way it was before the second function was called at all. 5160 5161See the comments in L<S<C<sub breakable_line>>|/breakable_line(from, to) (API)> 5162and 5163L<S<C<sub breakable_line_in_filename>>|/breakable_line_in_filename(file, from, to) (API)> 5164for more details. 5165 5166=back 5167 5168=cut 5169 5170use vars qw($filename_error); 5171$filename_error = ''; 5172 5173=head3 breakable_line(from, to) (API) 5174 5175The subroutine decides whether or not a line in the current file is breakable. 5176It walks through C<@dbline> within the range of lines specified, looking for 5177the first line that is breakable. 5178 5179If C<$to> is greater than C<$from>, the search moves forwards, finding the 5180first line I<after> C<$to> that's breakable, if there is one. 5181 5182If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the 5183first line I<before> C<$to> that's breakable, if there is one. 5184 5185=cut 5186 5187sub breakable_line { 5188 5189 my ( $from, $to ) = @_; 5190 5191 # $i is the start point. (Where are the FORTRAN programs of yesteryear?) 5192 my $i = $from; 5193 5194 # If there are at least 2 arguments, we're trying to search a range. 5195 if ( @_ >= 2 ) { 5196 5197 # $delta is positive for a forward search, negative for a backward one. 5198 my $delta = $from < $to ? +1 : -1; 5199 5200 # Keep us from running off the ends of the file. 5201 my $limit = $delta > 0 ? $#dbline : 1; 5202 5203 # Clever test. If you're a mathematician, it's obvious why this 5204 # test works. If not: 5205 # If $delta is positive (going forward), $limit will be $#dbline. 5206 # If $to is less than $limit, ($limit - $to) will be positive, times 5207 # $delta of 1 (positive), so the result is > 0 and we should use $to 5208 # as the stopping point. 5209 # 5210 # If $to is greater than $limit, ($limit - $to) is negative, 5211 # times $delta of 1 (positive), so the result is < 0 and we should 5212 # use $limit ($#dbline) as the stopping point. 5213 # 5214 # If $delta is negative (going backward), $limit will be 1. 5215 # If $to is zero, ($limit - $to) will be 1, times $delta of -1 5216 # (negative) so the result is > 0, and we use $to as the stopping 5217 # point. 5218 # 5219 # If $to is less than zero, ($limit - $to) will be positive, 5220 # times $delta of -1 (negative), so the result is not > 0, and 5221 # we use $limit (1) as the stopping point. 5222 # 5223 # If $to is 1, ($limit - $to) will zero, times $delta of -1 5224 # (negative), still giving zero; the result is not > 0, and 5225 # we use $limit (1) as the stopping point. 5226 # 5227 # if $to is >1, ($limit - $to) will be negative, times $delta of -1 5228 # (negative), giving a positive (>0) value, so we'll set $limit to 5229 # $to. 5230 5231 $limit = $to if ( $limit - $to ) * $delta > 0; 5232 5233 # The real search loop. 5234 # $i starts at $from (the point we want to start searching from). 5235 # We move through @dbline in the appropriate direction (determined 5236 # by $delta: either -1 (back) or +1 (ahead). 5237 # We stay in as long as we haven't hit an executable line 5238 # ($dbline[$i] == 0 means not executable) and we haven't reached 5239 # the limit yet (test similar to the above). 5240 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0; 5241 5242 } ## end if (@_ >= 2) 5243 5244 # If $i points to a line that is executable, return that. 5245 return $i unless $dbline[$i] == 0; 5246 5247 # Format the message and print it: no breakable lines in range. 5248 my ( $pl, $upto ) = ( '', '' ); 5249 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to; 5250 5251 # If there's a filename in filename_error, we'll see it. 5252 # If not, not. 5253 die "Line$pl $from$upto$filename_error not breakable\n"; 5254} ## end sub breakable_line 5255 5256=head3 breakable_line_in_filename(file, from, to) (API) 5257 5258Like C<breakable_line>, but look in another file. 5259 5260=cut 5261 5262sub breakable_line_in_filename { 5263 5264 # Capture the file name. 5265 my ($f) = shift; 5266 5267 # Swap the magic line array over there temporarily. 5268 local *dbline = $main::{ '_<' . $f }; 5269 5270 # If there's an error, it's in this other file. 5271 local $filename_error = " of '$f'"; 5272 5273 # Find the breakable line. 5274 breakable_line(@_); 5275 5276 # *dbline and $filename_error get restored when this block ends. 5277 5278} ## end sub breakable_line_in_filename 5279 5280=head3 break_on_line(lineno, [condition]) (API) 5281 5282Adds a breakpoint with the specified condition (or 1 if no condition was 5283specified) to the specified line. Dies if it can't. 5284 5285=cut 5286 5287sub break_on_line { 5288 my $i = shift; 5289 my $cond = @_ ? shift(@_) : 1; 5290 5291 my $inii = $i; 5292 my $after = ''; 5293 my $pl = ''; 5294 5295 # Woops, not a breakable line. $filename_error allows us to say 5296 # if it was in a different file. 5297 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0; 5298 5299 # Mark this file as having breakpoints in it. 5300 $had_breakpoints{$filename} |= 1; 5301 5302 # If there is an action or condition here already ... 5303 if ( $dbline{$i} ) { 5304 5305 # ... swap this condition for the existing one. 5306 $dbline{$i} =~ s/^[^\0]*/$cond/; 5307 } 5308 else { 5309 5310 # Nothing here - just add the condition. 5311 $dbline{$i} = $cond; 5312 5313 _set_breakpoint_enabled_status($filename, $i, 1); 5314 } 5315 5316 return; 5317} ## end sub break_on_line 5318 5319=head3 cmd_b_line(line, [condition]) (command) 5320 5321Wrapper for C<break_on_line>. Prints the failure message if it 5322doesn't work. 5323 5324=cut 5325 5326sub cmd_b_line { 5327 if (not eval { break_on_line(@_); 1 }) { 5328 local $\ = ''; 5329 print $OUT $@ and return; 5330 } 5331 5332 return; 5333} ## end sub cmd_b_line 5334 5335=head3 cmd_b_filename_line(line, [condition]) (command) 5336 5337Wrapper for C<break_on_filename_line>. Prints the failure message if it 5338doesn't work. 5339 5340=cut 5341 5342sub cmd_b_filename_line { 5343 if (not eval { break_on_filename_line(@_); 1 }) { 5344 local $\ = ''; 5345 print $OUT $@ and return; 5346 } 5347 5348 return; 5349} 5350 5351=head3 break_on_filename_line(file, line, [condition]) (API) 5352 5353Switches to the file specified and then calls C<break_on_line> to set 5354the breakpoint. 5355 5356=cut 5357 5358sub break_on_filename_line { 5359 my $f = shift; 5360 my $i = shift; 5361 my $cond = @_ ? shift(@_) : 1; 5362 5363 # Switch the magical hash temporarily. 5364 local *dbline = $main::{ '_<' . $f }; 5365 5366 # Localize the variables that break_on_line uses to make its message. 5367 local $filename_error = " of '$f'"; 5368 local $filename = $f; 5369 5370 # Add the breakpoint. 5371 break_on_line( $i, $cond ); 5372 5373 return; 5374} ## end sub break_on_filename_line 5375 5376=head3 break_on_filename_line_range(file, from, to, [condition]) (API) 5377 5378Switch to another file, search the range of lines specified for an 5379executable one, and put a breakpoint on the first one you find. 5380 5381=cut 5382 5383sub break_on_filename_line_range { 5384 my $f = shift; 5385 my $from = shift; 5386 my $to = shift; 5387 my $cond = @_ ? shift(@_) : 1; 5388 5389 # Find a breakable line if there is one. 5390 my $i = breakable_line_in_filename( $f, $from, $to ); 5391 5392 # Add the breakpoint. 5393 break_on_filename_line( $f, $i, $cond ); 5394 5395 return; 5396} ## end sub break_on_filename_line_range 5397 5398=head3 subroutine_filename_lines(subname, [condition]) (API) 5399 5400Search for a subroutine within a given file. The condition is ignored. 5401Uses C<find_sub> to locate the desired subroutine. 5402 5403=cut 5404 5405sub subroutine_filename_lines { 5406 my ( $subname ) = @_; 5407 5408 # Returned value from find_sub() is fullpathname:startline-endline. 5409 # The match creates the list (fullpathname, start, end). 5410 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/); 5411} ## end sub subroutine_filename_lines 5412 5413=head3 break_subroutine(subname) (API) 5414 5415Places a break on the first line possible in the specified subroutine. Uses 5416C<subroutine_filename_lines> to find the subroutine, and 5417C<break_on_filename_line_range> to place the break. 5418 5419=cut 5420 5421sub break_subroutine { 5422 my $subname = shift; 5423 5424 # Get filename, start, and end. 5425 my ( $file, $s, $e ) = subroutine_filename_lines($subname) 5426 or die "Subroutine $subname not found.\n"; 5427 5428 5429 # Null condition changes to '1' (always true). 5430 my $cond = @_ ? shift(@_) : 1; 5431 5432 # Put a break the first place possible in the range of lines 5433 # that make up this subroutine. 5434 break_on_filename_line_range( $file, $s, $e, $cond ); 5435 5436 return; 5437} ## end sub break_subroutine 5438 5439=head3 cmd_b_sub(subname, [condition]) (command) 5440 5441We take the incoming subroutine name and fully-qualify it as best we can. 5442 5443=over 4 5444 5445=item 1. If it's already fully-qualified, leave it alone. 5446 5447=item 2. Try putting it in the current package. 5448 5449=item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there. 5450 5451=item 4. If it starts with '::', put it in 'main::'. 5452 5453=back 5454 5455After all this cleanup, we call C<break_subroutine> to try to set the 5456breakpoint. 5457 5458=cut 5459 5460sub cmd_b_sub { 5461 my $subname = shift; 5462 my $cond = @_ ? shift : 1; 5463 5464 # If the subname isn't a code reference, qualify it so that 5465 # break_subroutine() will work right. 5466 if ( ref($subname) ne 'CODE' ) { 5467 5468 # Not Perl 4. 5469 $subname =~ s/'/::/g; 5470 my $s = $subname; 5471 5472 # Put it in this package unless it's already qualified. 5473 if ($subname !~ /::/) 5474 { 5475 $subname = $package . '::' . $subname; 5476 }; 5477 5478 # Requalify it into CORE::GLOBAL if qualifying it into this 5479 # package resulted in its not being defined, but only do so 5480 # if it really is in CORE::GLOBAL. 5481 my $core_name = "CORE::GLOBAL::$s"; 5482 if ((!defined(&$subname)) 5483 and ($s !~ /::/) 5484 and (defined &{$core_name})) 5485 { 5486 $subname = $core_name; 5487 } 5488 5489 # Put it in package 'main' if it has a leading ::. 5490 if ($subname =~ /\A::/) 5491 { 5492 $subname = "main" . $subname; 5493 } 5494 } ## end if ( ref($subname) ne 'CODE' ) { 5495 5496 # Try to set the breakpoint. 5497 if (not eval { break_subroutine( $subname, $cond ); 1 }) { 5498 local $\ = ''; 5499 print {$OUT} $@; 5500 return; 5501 } 5502 5503 return; 5504} ## end sub cmd_b_sub 5505 5506=head3 C<cmd_B> - delete breakpoint(s) (command) 5507 5508The command mostly parses the command line and tries to turn the argument 5509into a line spec. If it can't, it uses the current line. It then calls 5510C<delete_breakpoint> to actually do the work. 5511 5512If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments, 5513thereby deleting all the breakpoints. 5514 5515=cut 5516 5517sub cmd_B { 5518 my $cmd = shift; 5519 5520 # No line spec? Use dbline. 5521 # If there is one, use it if it's non-zero, or wipe it out if it is. 5522 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || ''); 5523 my $dbline = shift; 5524 5525 # If the line was dot, make the line the current one. 5526 $line =~ s/^\./$dbline/; 5527 5528 # If it's * we're deleting all the breakpoints. 5529 if ( $line eq '*' ) { 5530 if (not eval { delete_breakpoint(); 1 }) { 5531 print {$OUT} $@; 5532 } 5533 } 5534 5535 # If there is a line spec, delete the breakpoint on that line. 5536 elsif ( $line =~ /\A(\S.*)/ ) { 5537 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) { 5538 local $\ = ''; 5539 print {$OUT} $@; 5540 } 5541 } ## end elsif ($line =~ /^(\S.*)/) 5542 5543 # No line spec. 5544 else { 5545 print {$OUT} 5546 "Deleting a breakpoint requires a line number, or '*' for all\n" 5547 ; # hint 5548 } 5549 5550 return; 5551} ## end sub cmd_B 5552 5553=head3 delete_breakpoint([line]) (API) 5554 5555This actually does the work of deleting either a single breakpoint, or all 5556of them. 5557 5558For a single line, we look for it in C<@dbline>. If it's nonbreakable, we 5559just drop out with a message saying so. If it is, we remove the condition 5560part of the 'condition\0action' that says there's a breakpoint here. If, 5561after we've done that, there's nothing left, we delete the corresponding 5562line in C<%dbline> to signal that no action needs to be taken for this line. 5563 5564For all breakpoints, we iterate through the keys of C<%had_breakpoints>, 5565which lists all currently-loaded files which have breakpoints. We then look 5566at each line in each of these files, temporarily switching the C<%dbline> 5567and C<@dbline> structures to point to the files in question, and do what 5568we did in the single line case: delete the condition in C<@dbline>, and 5569delete the key in C<%dbline> if nothing's left. 5570 5571We then wholesale delete C<%postponed>, C<%postponed_file>, and 5572C<%break_on_load>, because these structures contain breakpoints for files 5573and code that haven't been loaded yet. We can just kill these off because there 5574are no magical debugger structures associated with them. 5575 5576=cut 5577 5578sub _remove_breakpoint_entry { 5579 my ($fn, $i) = @_; 5580 5581 delete $dbline{$i}; 5582 _delete_breakpoint_data_ref($fn, $i); 5583 5584 return; 5585} 5586 5587sub _delete_all_breakpoints { 5588 print {$OUT} "Deleting all breakpoints...\n"; 5589 5590 # %had_breakpoints lists every file that had at least one 5591 # breakpoint in it. 5592 for my $fn ( keys %had_breakpoints ) { 5593 5594 # Switch to the desired file temporarily. 5595 local *dbline = $main::{ '_<' . $fn }; 5596 5597 $max = $#dbline; 5598 5599 # For all lines in this file ... 5600 for my $i (1 .. $max) { 5601 5602 # If there's a breakpoint or action on this line ... 5603 if ( defined $dbline{$i} ) { 5604 5605 # ... remove the breakpoint. 5606 $dbline{$i} =~ s/\A[^\0]+//; 5607 if ( $dbline{$i} =~ s/\A\0?\z// ) { 5608 # Remove the entry altogether if no action is there. 5609 _remove_breakpoint_entry($fn, $i); 5610 } 5611 } ## end if (defined $dbline{$i... 5612 } ## end for $i (1 .. $max) 5613 5614 # If, after we turn off the "there were breakpoints in this file" 5615 # bit, the entry in %had_breakpoints for this file is zero, 5616 # we should remove this file from the hash. 5617 if ( not $had_breakpoints{$fn} &= (~1) ) { 5618 delete $had_breakpoints{$fn}; 5619 } 5620 } ## end for my $fn (keys %had_breakpoints) 5621 5622 # Kill off all the other breakpoints that are waiting for files that 5623 # haven't been loaded yet. 5624 undef %postponed; 5625 undef %postponed_file; 5626 undef %break_on_load; 5627 5628 return; 5629} 5630 5631sub _delete_breakpoint_from_line { 5632 my ($i) = @_; 5633 5634 # Woops. This line wasn't breakable at all. 5635 die "Line $i not breakable.\n" if $dbline[$i] == 0; 5636 5637 # Kill the condition, but leave any action. 5638 $dbline{$i} =~ s/\A[^\0]*//; 5639 5640 # Remove the entry entirely if there's no action left. 5641 if ($dbline{$i} eq '') { 5642 _remove_breakpoint_entry($filename, $i); 5643 } 5644 5645 return; 5646} 5647 5648sub delete_breakpoint { 5649 my $i = shift; 5650 5651 # If we got a line, delete just that one. 5652 if ( defined($i) ) { 5653 _delete_breakpoint_from_line($i); 5654 } 5655 # No line; delete them all. 5656 else { 5657 _delete_all_breakpoints(); 5658 } 5659 5660 return; 5661} 5662 5663=head3 cmd_stop (command) 5664 5665This is meant to be part of the new command API, but it isn't called or used 5666anywhere else in the debugger. XXX It is probably meant for use in development 5667of new commands. 5668 5669=cut 5670 5671sub cmd_stop { # As on ^C, but not signal-safy. 5672 $signal = 1; 5673} 5674 5675=head3 C<cmd_e> - threads 5676 5677Display the current thread id: 5678 5679 e 5680 5681This could be how (when implemented) to send commands to this thread id (e cmd) 5682or that thread id (e tid cmd). 5683 5684=cut 5685 5686sub cmd_e { 5687 my $cmd = shift; 5688 my $line = shift; 5689 unless (exists($INC{'threads.pm'})) { 5690 print "threads not loaded($ENV{PERL5DB_THREADED}) 5691 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 5692 } else { 5693 my $tid = threads->tid; 5694 print "thread id: $tid\n"; 5695 } 5696} ## end sub cmd_e 5697 5698=head3 C<cmd_E> - list of thread ids 5699 5700Display the list of available thread ids: 5701 5702 E 5703 5704This could be used (when implemented) to send commands to all threads (E cmd). 5705 5706=cut 5707 5708sub cmd_E { 5709 my $cmd = shift; 5710 my $line = shift; 5711 unless (exists($INC{'threads.pm'})) { 5712 print "threads not loaded($ENV{PERL5DB_THREADED}) 5713 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 5714 } else { 5715 my $tid = threads->tid; 5716 print "thread ids: ".join(', ', 5717 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list 5718 )."\n"; 5719 } 5720} ## end sub cmd_E 5721 5722=head3 C<cmd_h> - help command (command) 5723 5724Does the work of either 5725 5726=over 4 5727 5728=item * 5729 5730Showing all the debugger help 5731 5732=item * 5733 5734Showing help for a specific command 5735 5736=back 5737 5738=cut 5739 5740use vars qw($help); 5741use vars qw($summary); 5742 5743sub cmd_h { 5744 my $cmd = shift; 5745 5746 # If we have no operand, assume null. 5747 my $line = shift || ''; 5748 5749 # 'h h'. Print the long-format help. 5750 if ( $line =~ /\Ah\s*\z/ ) { 5751 print_help($help); 5752 } 5753 5754 # 'h <something>'. Search for the command and print only its help. 5755 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) { 5756 5757 # support long commands; otherwise bogus errors 5758 # happen when you ask for h on <CR> for example 5759 my $qasked = quotemeta($asked); # for searching; we don't 5760 # want to use it as a pattern. 5761 # XXX: finds CR but not <CR> 5762 5763 # Search the help string for the command. 5764 if ( 5765 $help =~ /^ # Start of a line 5766 <? # Optional '<' 5767 (?:[IB]<) # Optional markup 5768 $qasked # The requested command 5769 /mx 5770 ) 5771 { 5772 5773 # It's there; pull it out and print it. 5774 while ( 5775 $help =~ /^ 5776 (<? # Optional '<' 5777 (?:[IB]<) # Optional markup 5778 $qasked # The command 5779 ([\s\S]*?) # Description line(s) 5780 \n) # End of last description line 5781 (?!\s) # Next line not starting with 5782 # whitespace 5783 /mgx 5784 ) 5785 { 5786 print_help($1); 5787 } 5788 } 5789 5790 # Not found; not a debugger command. 5791 else { 5792 print_help("B<$asked> is not a debugger command.\n"); 5793 } 5794 } ## end elsif ($line =~ /^(\S.*)$/) 5795 5796 # 'h' - print the summary help. 5797 else { 5798 print_help($summary); 5799 } 5800} ## end sub cmd_h 5801 5802=head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command) 5803 5804To list breakpoints, the command has to look determine where all of them are 5805first. It starts a C<%had_breakpoints>, which tells us what all files have 5806breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the 5807magic source and breakpoint data structures) to the file, and then look 5808through C<%dbline> for lines with breakpoints and/or actions, listing them 5809out. We look through C<%postponed> not-yet-compiled subroutines that have 5810breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files 5811that have breakpoints. 5812 5813Watchpoints are simpler: we just list the entries in C<@to_watch>. 5814 5815=cut 5816 5817sub _cmd_L_calc_arg { 5818 # If no argument, list everything. Pre-5.8.0 version always lists 5819 # everything 5820 my $arg = shift || 'abw'; 5821 if ($CommandSet ne '580') 5822 { 5823 $arg = 'abw'; 5824 } 5825 5826 return $arg; 5827} 5828 5829sub _cmd_L_calc_wanted_flags { 5830 my $arg = _cmd_L_calc_arg(shift); 5831 5832 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w)); 5833} 5834 5835 5836sub _cmd_L_handle_breakpoints { 5837 my ($handle_db_line) = @_; 5838 5839 BREAKPOINTS_SCAN: 5840 # Look in all the files with breakpoints... 5841 for my $file ( keys %had_breakpoints ) { 5842 5843 # Temporary switch to this file. 5844 local *dbline = $main::{ '_<' . $file }; 5845 5846 # Set up to look through the whole file. 5847 $max = $#dbline; 5848 my $was; # Flag: did we print something 5849 # in this file? 5850 5851 # For each line in the file ... 5852 for my $i (1 .. $max) { 5853 5854 # We've got something on this line. 5855 if ( defined $dbline{$i} ) { 5856 5857 # Print the header if we haven't. 5858 if (not $was++) { 5859 print {$OUT} "$file:\n"; 5860 } 5861 5862 # Print the line. 5863 print {$OUT} " $i:\t", $dbline[$i]; 5864 5865 $handle_db_line->($dbline{$i}); 5866 5867 # Quit if the user hit interrupt. 5868 if ($signal) { 5869 last BREAKPOINTS_SCAN; 5870 } 5871 } ## end if (defined $dbline{$i... 5872 } ## end for my $i (1 .. $max) 5873 } ## end for my $file (keys %had_breakpoints) 5874 5875 return; 5876} 5877 5878sub _cmd_L_handle_postponed_breakpoints { 5879 my ($handle_db_line) = @_; 5880 5881 print {$OUT} "Postponed breakpoints in files:\n"; 5882 5883 POSTPONED_SCANS: 5884 for my $file ( keys %postponed_file ) { 5885 my $db = $postponed_file{$file}; 5886 print {$OUT} " $file:\n"; 5887 for my $line ( sort { $a <=> $b } keys %$db ) { 5888 print {$OUT} " $line:\n"; 5889 5890 $handle_db_line->($db->{$line}); 5891 5892 if ($signal) { 5893 last POSTPONED_SCANS; 5894 } 5895 } 5896 if ($signal) { 5897 last POSTPONED_SCANS; 5898 } 5899 } 5900 5901 return; 5902} 5903 5904 5905sub cmd_L { 5906 my $cmd = shift; 5907 5908 my ($action_wanted, $break_wanted, $watch_wanted) = 5909 _cmd_L_calc_wanted_flags(shift); 5910 5911 my $handle_db_line = sub { 5912 my ($l) = @_; 5913 5914 my ( $stop, $action ) = split( /\0/, $l ); 5915 5916 if ($stop and $break_wanted) { 5917 print {$OUT} " break if (", $stop, ")\n" 5918 } 5919 5920 if ($action && $action_wanted) { 5921 print {$OUT} " action: ", $action, "\n" 5922 } 5923 5924 return; 5925 }; 5926 5927 # Breaks and actions are found together, so we look in the same place 5928 # for both. 5929 if ( $break_wanted or $action_wanted ) { 5930 _cmd_L_handle_breakpoints($handle_db_line); 5931 } 5932 5933 # Look for breaks in not-yet-compiled subs: 5934 if ( %postponed and $break_wanted ) { 5935 print {$OUT} "Postponed breakpoints in subroutines:\n"; 5936 my $subname; 5937 SUBS_SCAN: 5938 for $subname ( keys %postponed ) { 5939 print {$OUT} " $subname\t$postponed{$subname}\n"; 5940 if ($signal) { 5941 last SUBS_SCAN; 5942 } 5943 } 5944 } ## end if (%postponed and $break_wanted) 5945 5946 # Find files that have not-yet-loaded breaks: 5947 my @have = map { # Combined keys 5948 keys %{ $postponed_file{$_} } 5949 } keys %postponed_file; 5950 5951 # If there are any, list them. 5952 if ( @have and ( $break_wanted or $action_wanted ) ) { 5953 _cmd_L_handle_postponed_breakpoints($handle_db_line); 5954 } ## end if (@have and ($break_wanted... 5955 5956 if ( %break_on_load and $break_wanted ) { 5957 print {$OUT} "Breakpoints on load:\n"; 5958 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) { 5959 print {$OUT} " $filename\n"; 5960 last BREAK_ON_LOAD if $signal; 5961 } 5962 } ## end if (%break_on_load and... 5963 5964 if ($watch_wanted and ( $trace & 2 )) { 5965 print {$OUT} "Watch-expressions:\n" if @to_watch; 5966 TO_WATCH: for my $expr (@to_watch) { 5967 print {$OUT} " $expr\n"; 5968 last TO_WATCH if $signal; 5969 } 5970 } 5971 5972 return; 5973} ## end sub cmd_L 5974 5975=head3 C<cmd_M> - list modules (command) 5976 5977Just call C<list_modules>. 5978 5979=cut 5980 5981sub cmd_M { 5982 list_modules(); 5983 5984 return; 5985} 5986 5987=head3 C<cmd_o> - options (command) 5988 5989If this is just C<o> by itself, we list the current settings via 5990C<dump_option>. If there's a nonblank value following it, we pass that on to 5991C<parse_options> for processing. 5992 5993=cut 5994 5995sub cmd_o { 5996 my $cmd = shift; 5997 my $opt = shift || ''; # opt[=val] 5998 5999 # Nonblank. Try to parse and process. 6000 if ( $opt =~ /^(\S.*)/ ) { 6001 parse_options($1); 6002 } 6003 6004 # Blank. List the current option settings. 6005 else { 6006 for (@options) { 6007 dump_option($_); 6008 } 6009 } 6010} ## end sub cmd_o 6011 6012=head3 C<cmd_O> - nonexistent in 5.8.x (command) 6013 6014Advises the user that the O command has been renamed. 6015 6016=cut 6017 6018sub cmd_O { 6019 print $OUT "The old O command is now the o command.\n"; # hint 6020 print $OUT "Use 'h' to get current command help synopsis or\n"; # 6021 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; # 6022} 6023 6024=head3 C<cmd_v> - view window (command) 6025 6026Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to 6027move back a few lines to list the selected line in context. Uses C<_cmd_l_main> 6028to do the actual listing after figuring out the range of line to request. 6029 6030=cut 6031 6032use vars qw($preview); 6033 6034sub cmd_v { 6035 my $cmd = shift; 6036 my $line = shift; 6037 6038 # Extract the line to list around. (Astute readers will have noted that 6039 # this pattern will match whether or not a numeric line is specified, 6040 # which means that we'll always enter this loop (though a non-numeric 6041 # argument results in no action at all)). 6042 if ( $line =~ /^(\d*)$/ ) { 6043 6044 # Total number of lines to list (a windowful). 6045 $incr = $window - 1; 6046 6047 # Set the start to the argument given (if there was one). 6048 $start = $1 if $1; 6049 6050 # Back up by the context amount. 6051 $start -= $preview; 6052 6053 # Put together a linespec that _cmd_l_main will like. 6054 $line = $start . '-' . ( $start + $incr ); 6055 6056 # List the lines. 6057 _cmd_l_main( $line ); 6058 } ## end if ($line =~ /^(\d*)$/) 6059} ## end sub cmd_v 6060 6061=head3 C<cmd_w> - add a watch expression (command) 6062 6063The 5.8 version of this command adds a watch expression if one is specified; 6064it does nothing if entered with no operands. 6065 6066We extract the expression, save it, evaluate it in the user's context, and 6067save the value. We'll re-evaluate it each time the debugger passes a line, 6068and will stop (see the code at the top of the command loop) if the value 6069of any of the expressions changes. 6070 6071=cut 6072 6073sub _add_watch_expr { 6074 my $expr = shift; 6075 6076 # ... save it. 6077 push @to_watch, $expr; 6078 6079 # Parameterize DB::eval and call it to get the expression's value 6080 # in the user's context. This version can handle expressions which 6081 # return a list value. 6082 $evalarg = $expr; 6083 # The &-call is here to ascertain the mutability of @_. 6084 my ($val) = join( ' ', &DB::eval); 6085 $val = ( defined $val ) ? "'$val'" : 'undef'; 6086 6087 # Save the current value of the expression. 6088 push @old_watch, $val; 6089 6090 # We are now watching expressions. 6091 $trace |= 2; 6092 6093 return; 6094} 6095 6096sub cmd_w { 6097 my $cmd = shift; 6098 6099 # Null expression if no arguments. 6100 my $expr = shift || ''; 6101 6102 # If expression is not null ... 6103 if ( $expr =~ /\A\S/ ) { 6104 _add_watch_expr($expr); 6105 } ## end if ($expr =~ /^(\S.*)/) 6106 6107 # You have to give one to get one. 6108 else { 6109 print $OUT "Adding a watch-expression requires an expression\n"; # hint 6110 } 6111 6112 return; 6113} 6114 6115=head3 C<cmd_W> - delete watch expressions (command) 6116 6117This command accepts either a watch expression to be removed from the list 6118of watch expressions, or C<*> to delete them all. 6119 6120If C<*> is specified, we simply empty the watch expression list and the 6121watch expression value list. We also turn off the bit that says we've got 6122watch expressions. 6123 6124If an expression (or partial expression) is specified, we pattern-match 6125through the expressions and remove the ones that match. We also discard 6126the corresponding values. If no watch expressions are left, we turn off 6127the I<watching expressions> bit. 6128 6129=cut 6130 6131sub cmd_W { 6132 my $cmd = shift; 6133 my $expr = shift || ''; 6134 6135 # Delete them all. 6136 if ( $expr eq '*' ) { 6137 6138 # Not watching now. 6139 $trace &= ~2; 6140 6141 print $OUT "Deleting all watch expressions ...\n"; 6142 6143 # And all gone. 6144 @to_watch = @old_watch = (); 6145 } 6146 6147 # Delete one of them. 6148 elsif ( $expr =~ /^(\S.*)/ ) { 6149 6150 # Where we are in the list. 6151 my $i_cnt = 0; 6152 6153 # For each expression ... 6154 foreach (@to_watch) { 6155 my $val = $to_watch[$i_cnt]; 6156 6157 # Does this one match the command argument? 6158 if ( $val eq $expr ) { # =~ m/^\Q$i$/) { 6159 # Yes. Turn it off, and its value too. 6160 splice( @to_watch, $i_cnt, 1 ); 6161 splice( @old_watch, $i_cnt, 1 ); 6162 } 6163 $i_cnt++; 6164 } ## end foreach (@to_watch) 6165 6166 # We don't bother to turn watching off because 6167 # a) we don't want to stop calling watchfunction() if it exists 6168 # b) foreach over a null list doesn't do anything anyway 6169 6170 } ## end elsif ($expr =~ /^(\S.*)/) 6171 6172 # No command arguments entered. 6173 else { 6174 print $OUT 6175 "Deleting a watch-expression requires an expression, or '*' for all\n" 6176 ; # hint 6177 } 6178} ## end sub cmd_W 6179 6180### END of the API section 6181 6182=head1 SUPPORT ROUTINES 6183 6184These are general support routines that are used in a number of places 6185throughout the debugger. 6186 6187=head2 save 6188 6189save() saves the user's versions of globals that would mess us up in C<@saved>, 6190and installs the versions we like better. 6191 6192=cut 6193 6194sub save { 6195 6196 # Save eval failure, command failure, extended OS error, output field 6197 # separator, input record separator, output record separator and 6198 # the warning setting. 6199 @saved = ( $@, $!, $^E, $,, $/, $\, $^W ); 6200 6201 $, = ""; # output field separator is null string 6202 $/ = "\n"; # input record separator is newline 6203 $\ = ""; # output record separator is null string 6204 $^W = 0; # warnings are off 6205} ## end sub save 6206 6207=head2 C<print_lineinfo> - show where we are now 6208 6209print_lineinfo prints whatever it is that it is handed; it prints it to the 6210C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows 6211us to feed line information to a client editor without messing up the 6212debugger output. 6213 6214=cut 6215 6216sub print_lineinfo { 6217 6218 # Make the terminal sensible if we're not the primary debugger. 6219 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$; 6220 local $\ = ''; 6221 local $, = ''; 6222 # $LINEINFO may be undef if $noTTY is set or some other issue. 6223 if ($LINEINFO) 6224 { 6225 print {$LINEINFO} @_; 6226 } 6227} ## end sub print_lineinfo 6228 6229=head2 C<postponed_sub> 6230 6231Handles setting postponed breakpoints in subroutines once they're compiled. 6232For breakpoints, we use C<DB::find_sub> to locate the source file and line 6233range for the subroutine, then mark the file as having a breakpoint, 6234temporarily switch the C<*dbline> glob over to the source file, and then 6235search the given range of lines to find a breakable line. If we find one, 6236we set the breakpoint on it, deleting the breakpoint from C<%postponed>. 6237 6238=cut 6239 6240# The following takes its argument via $evalarg to preserve current @_ 6241 6242sub postponed_sub { 6243 6244 # Get the subroutine name. 6245 my $subname = shift; 6246 6247 # If this is a 'break +<n> if <condition>' ... 6248 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) { 6249 6250 # If there's no offset, use '+0'. 6251 my $offset = $1 || 0; 6252 6253 # find_sub's value is 'fullpath-filename:start-stop'. It's 6254 # possible that the filename might have colons in it too. 6255 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ ); 6256 if ($i) { 6257 6258 # We got the start line. Add the offset '+<n>' from 6259 # $postponed{subname}. 6260 $i += $offset; 6261 6262 # Switch to the file this sub is in, temporarily. 6263 local *dbline = $main::{ '_<' . $file }; 6264 6265 # No warnings, please. 6266 local $^W = 0; # != 0 is magical below 6267 6268 # This file's got a breakpoint in it. 6269 $had_breakpoints{$file} |= 1; 6270 6271 # Last line in file. 6272 $max = $#dbline; 6273 6274 # Search forward until we hit a breakable line or get to 6275 # the end of the file. 6276 ++$i until $dbline[$i] != 0 or $i >= $max; 6277 6278 # Copy the breakpoint in and delete it from %postponed. 6279 $dbline{$i} = delete $postponed{$subname}; 6280 } ## end if ($i) 6281 6282 # find_sub didn't find the sub. 6283 else { 6284 local $\ = ''; 6285 print $OUT "Subroutine $subname not found.\n"; 6286 } 6287 return; 6288 } ## end if ($postponed{$subname... 6289 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 } 6290 6291 #print $OUT "In postponed_sub for '$subname'.\n"; 6292} ## end sub postponed_sub 6293 6294=head2 C<postponed> 6295 6296Called after each required file is compiled, but before it is executed; 6297also called if the name of a just-compiled subroutine is a key of 6298C<%postponed>. Propagates saved breakpoints (from S<C<b compile>>, 6299S<C<b load>>, etc.) into the just-compiled code. 6300 6301If this is a C<require>'d file, the incoming parameter is the glob 6302C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file. 6303 6304If it's a subroutine, the incoming parameter is the subroutine name. 6305 6306=cut 6307 6308sub postponed { 6309 6310 # If there's a break, process it. 6311 if ($ImmediateStop) { 6312 6313 # Right, we've stopped. Turn it off. 6314 $ImmediateStop = 0; 6315 6316 # Enter the command loop when DB::DB gets called. 6317 $signal = 1; 6318 } 6319 6320 # If this is a subroutine, let postponed_sub() deal with it. 6321 if (ref(\$_[0]) ne 'GLOB') { 6322 return postponed_sub(@_); 6323 } 6324 6325 # Not a subroutine. Deal with the file. 6326 local *dbline = shift; 6327 my $filename = $dbline; 6328 $filename =~ s/^_<//; 6329 local $\ = ''; 6330 $signal = 1, print $OUT "'$filename' loaded...\n" 6331 if $break_on_load{$filename}; 6332 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame; 6333 6334 # Do we have any breakpoints to put in this file? 6335 return unless $postponed_file{$filename}; 6336 6337 # Yes. Mark this file as having breakpoints. 6338 $had_breakpoints{$filename} |= 1; 6339 6340 # "Cannot be done: insufficient magic" - we can't just put the 6341 # breakpoints saved in %postponed_file into %dbline by assigning 6342 # the whole hash; we have to do it one item at a time for the 6343 # breakpoints to be set properly. 6344 #%dbline = %{$postponed_file{$filename}}; 6345 6346 # Set the breakpoints, one at a time. 6347 my $key; 6348 6349 for $key ( keys %{ $postponed_file{$filename} } ) { 6350 6351 # Stash the saved breakpoint into the current file's magic line array. 6352 $dbline{$key} = ${ $postponed_file{$filename} }{$key}; 6353 } 6354 6355 # This file's been compiled; discard the stored breakpoints. 6356 delete $postponed_file{$filename}; 6357 6358} ## end sub postponed 6359 6360=head2 C<dumpit> 6361 6362C<dumpit> is the debugger's wrapper around dumpvar.pl. 6363 6364It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and 6365a reference to a variable (the thing to be dumped) as its input. 6366 6367The incoming filehandle is selected for output (C<dumpvar.pl> is printing to 6368the currently-selected filehandle, thank you very much). The current 6369values of the package globals C<$single> and C<$trace> are backed up in 6370lexicals, and they are turned off (this keeps the debugger from trying 6371to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to 6372preserve its current value and it is set to zero to prevent entry/exit 6373messages from printing, and C<$doret> is localized as well and set to -2 to 6374prevent return values from being shown. 6375 6376C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and 6377tries to load it (note: if you have a C<dumpvar.pl> ahead of the 6378installed version in C<@INC>, yours will be used instead. Possible security 6379problem?). 6380 6381It then checks to see if the subroutine C<main::dumpValue> is now defined 6382it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()> 6383localizes the globals necessary for things to be sane when C<main::dumpValue()> 6384is called, and picks up the variable to be dumped from the parameter list. 6385 6386It checks the package global C<%options> to see if there's a C<dumpDepth> 6387specified. If not, -1 is assumed; if so, the supplied value gets passed on to 6388C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a 6389structure: -1 means dump everything. 6390 6391C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a 6392warning. 6393 6394In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored 6395and we then return to the caller. 6396 6397=cut 6398 6399sub dumpit { 6400 6401 # Save the current output filehandle and switch to the one 6402 # passed in as the first parameter. 6403 my $savout = select(shift); 6404 6405 # Save current settings of $single and $trace, and then turn them off. 6406 my $osingle = $single; 6407 my $otrace = $trace; 6408 $single = $trace = 0; 6409 6410 # XXX Okay, what do $frame and $doret do, again? 6411 local $frame = 0; 6412 local $doret = -2; 6413 6414 # Load dumpvar.pl unless we've already got the sub we need from it. 6415 unless ( defined &main::dumpValue ) { 6416 do 'dumpvar.pl' or die $@; 6417 } 6418 6419 # If the load succeeded (or we already had dumpvalue()), go ahead 6420 # and dump things. 6421 if ( defined &main::dumpValue ) { 6422 local $\ = ''; 6423 local $, = ''; 6424 local $" = ' '; 6425 my $v = shift; 6426 my $maxdepth = shift || $option{dumpDepth}; 6427 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth 6428 main::dumpValue( $v, $maxdepth ); 6429 } ## end if (defined &main::dumpValue) 6430 6431 # Oops, couldn't load dumpvar.pl. 6432 else { 6433 local $\ = ''; 6434 print $OUT "dumpvar.pl not available.\n"; 6435 } 6436 6437 # Reset $single and $trace to their old values. 6438 $single = $osingle; 6439 $trace = $otrace; 6440 6441 # Restore the old filehandle. 6442 select($savout); 6443} ## end sub dumpit 6444 6445=head2 C<print_trace> 6446 6447C<print_trace>'s job is to print a stack trace. It does this via the 6448C<dump_trace> routine, which actually does all the ferreting-out of the 6449stack trace data. C<print_trace> takes care of formatting it nicely and 6450printing it to the proper filehandle. 6451 6452Parameters: 6453 6454=over 4 6455 6456=item * 6457 6458The filehandle to print to. 6459 6460=item * 6461 6462How many frames to skip before starting trace. 6463 6464=item * 6465 6466How many frames to print. 6467 6468=item * 6469 6470A flag: if true, print a I<short> trace without filenames, line numbers, or arguments 6471 6472=back 6473 6474The original comment below seems to be noting that the traceback may not be 6475correct if this routine is called in a tied method. 6476 6477=cut 6478 6479# Tied method do not create a context, so may get wrong message: 6480 6481sub print_trace { 6482 local $\ = ''; 6483 my $fh = shift; 6484 6485 # If this is going to a client editor, but we're not the primary 6486 # debugger, reset it first. 6487 resetterm(1) 6488 if $fh eq $LINEINFO # client editor 6489 and $LINEINFO eq $OUT # normal output 6490 and $term_pid != $$; # not the primary 6491 6492 # Collect the actual trace information to be formatted. 6493 # This is an array of hashes of subroutine call info. 6494 my @sub = dump_trace( $_[0] + 1, $_[1] ); 6495 6496 # Grab the "short report" flag from @_. 6497 my $short = $_[2]; # Print short report, next one for sub name 6498 6499 # Run through the traceback info, format it, and print it. 6500 my $s; 6501 for my $i (0 .. $#sub) { 6502 6503 # Drop out if the user has lost interest and hit control-C. 6504 last if $signal; 6505 6506 # Set the separator so arrays print nice. 6507 local $" = ', '; 6508 6509 # Grab and stringify the arguments if they are there. 6510 my $args = 6511 defined $sub[$i]{args} 6512 ? "(@{ $sub[$i]{args} })" 6513 : ''; 6514 6515 # Shorten them up if $maxtrace says they're too long. 6516 $args = ( substr $args, 0, $maxtrace - 3 ) . '...' 6517 if length $args > $maxtrace; 6518 6519 # Get the file name. 6520 my $file = $sub[$i]{file}; 6521 6522 # Put in a filename header if short is off. 6523 $file = $file eq '-e' ? $file : "file '$file'" unless $short; 6524 6525 # Get the actual sub's name, and shorten to $maxtrace's requirement. 6526 $s = $sub[$i]{'sub'}; 6527 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace; 6528 6529 # Short report uses trimmed file and sub names. 6530 if ($short) { 6531 my $sub = @_ >= 4 ? $_[3] : $s; 6532 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n"; 6533 } ## end if ($short) 6534 6535 # Non-short report includes full names. 6536 else { 6537 print $fh "$sub[$i]{context} = $s$args" 6538 . " called from $file" 6539 . " line $sub[$i]{line}\n"; 6540 } 6541 } ## end for my $i (0 .. $#sub) 6542} ## end sub print_trace 6543 6544=head2 dump_trace(skip[,count]) 6545 6546Actually collect the traceback information available via C<caller()>. It does 6547some filtering and cleanup of the data, but mostly it just collects it to 6548make C<print_trace()>'s job easier. 6549 6550C<skip> defines the number of stack frames to be skipped, working backwards 6551from the most current. C<count> determines the total number of frames to 6552be returned; all of them (well, the first 10^9) are returned if C<count> 6553is omitted. 6554 6555This routine returns a list of hashes, from most-recent to least-recent 6556stack frame. Each has the following keys and values: 6557 6558=over 4 6559 6560=item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array) 6561 6562=item * C<sub> - subroutine name, or C<eval> information 6563 6564=item * C<args> - undef, or a reference to an array of arguments 6565 6566=item * C<file> - the file in which this item was defined (if any) 6567 6568=item * C<line> - the line on which it was defined 6569 6570=back 6571 6572=cut 6573 6574sub _dump_trace_calc_saved_single_arg 6575{ 6576 my ($nothard, $arg) = @_; 6577 6578 my $type; 6579 if ( not defined $arg ) { # undefined parameter 6580 return "undef"; 6581 } 6582 6583 elsif ( $nothard and tied $arg ) { # tied parameter 6584 return "tied"; 6585 } 6586 elsif ( $nothard and $type = ref $arg ) { # reference 6587 return "ref($type)"; 6588 } 6589 else { # can be stringified 6590 local $_ = 6591 "$arg"; # Safe to stringify now - should not call f(). 6592 6593 # Backslash any single-quotes or backslashes. 6594 s/([\'\\])/\\$1/g; 6595 6596 # Single-quote it unless it's a number or a colon-separated 6597 # name. 6598 s/(.*)/'$1'/s 6599 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x; 6600 6601 # Turn high-bit characters into meta-whatever, and controls into like 6602 # '^D'. 6603 require 'meta_notation.pm'; 6604 $_ = _meta_notation($_) if /[[:^print:]]/a; 6605 6606 return $_; 6607 } 6608} 6609 6610sub _dump_trace_calc_save_args { 6611 my ($nothard) = @_; 6612 6613 return [ 6614 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args 6615 ]; 6616} 6617 6618sub dump_trace { 6619 6620 # How many levels to skip. 6621 my $skip = shift; 6622 6623 # How many levels to show. (1e9 is a cheap way of saying "all of them"; 6624 # it's unlikely that we'll have more than a billion stack frames. If you 6625 # do, you've got an awfully big machine...) 6626 my $count = shift || 1e9; 6627 6628 # We increment skip because caller(1) is the first level *back* from 6629 # the current one. Add $skip to the count of frames so we have a 6630 # simple stop criterion, counting from $skip to $count+$skip. 6631 $skip++; 6632 $count += $skip; 6633 6634 # These variables are used to capture output from caller(); 6635 my ( $p, $file, $line, $sub, $h, $context ); 6636 6637 my ( $e, $r, @sub, $args ); 6638 6639 # XXX Okay... why'd we do that? 6640 my $nothard = not $frame & 8; 6641 local $frame = 0; 6642 6643 # Do not want to trace this. 6644 my $otrace = $trace; 6645 $trace = 0; 6646 6647 # Start out at the skip count. 6648 # If we haven't reached the number of frames requested, and caller() is 6649 # still returning something, stay in the loop. (If we pass the requested 6650 # number of stack frames, or we run out - caller() returns nothing - we 6651 # quit. 6652 # Up the stack frame index to go back one more level each time. 6653 for ( 6654 my $i = $skip ; 6655 $i < $count 6656 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ; 6657 $i++ 6658 ) 6659 { 6660 # if the sub has args ($h true), make an anonymous array of the 6661 # dumped args. 6662 my $args = $h ? _dump_trace_calc_save_args($nothard) : undef; 6663 6664 # If context is true, this is array (@)context. 6665 # If context is false, this is scalar ($) context. 6666 # If neither, context isn't defined. (This is apparently a 'can't 6667 # happen' trap.) 6668 $context = $context ? '@' : ( defined $context ? "\$" : '.' ); 6669 6670 # remove trailing newline-whitespace-semicolon-end of line sequence 6671 # from the eval text, if any. 6672 $e =~ s/\n\s*\;\s*\Z// if $e; 6673 6674 # Escape backslashed single-quotes again if necessary. 6675 $e =~ s/([\\\'])/\\$1/g if $e; 6676 6677 # if the require flag is true, the eval text is from a require. 6678 if ($r) { 6679 $sub = "require '$e'"; 6680 } 6681 6682 # if it's false, the eval text is really from an eval. 6683 elsif ( defined $r ) { 6684 $sub = "eval '$e'"; 6685 } 6686 6687 # If the sub is '(eval)', this is a block eval, meaning we don't 6688 # know what the eval'ed text actually was. 6689 elsif ( $sub eq '(eval)' ) { 6690 $sub = "eval {...}"; 6691 } 6692 6693 # Stick the collected information into @sub as an anonymous hash. 6694 push( 6695 @sub, 6696 { 6697 context => $context, 6698 sub => $sub, 6699 args => $args, 6700 file => $file, 6701 line => $line 6702 } 6703 ); 6704 6705 # Stop processing frames if the user hit control-C. 6706 last if $signal; 6707 } ## end for ($i = $skip ; $i < ... 6708 6709 # Restore the trace value again. 6710 $trace = $otrace; 6711 @sub; 6712} ## end sub dump_trace 6713 6714=head2 C<action()> 6715 6716C<action()> takes input provided as the argument to an add-action command, 6717either pre- or post-, and makes sure it's a complete command. It doesn't do 6718any fancy parsing; it just keeps reading input until it gets a string 6719without a trailing backslash. 6720 6721=cut 6722 6723sub action { 6724 my $action = shift; 6725 6726 while ( $action =~ s/\\$// ) { 6727 6728 # We have a backslash on the end. Read more. 6729 $action .= gets(); 6730 } ## end while ($action =~ s/\\$//) 6731 6732 # Return the assembled action. 6733 $action; 6734} ## end sub action 6735 6736=head2 unbalanced 6737 6738This routine mostly just packages up a regular expression to be used 6739to check that the thing it's being matched against has properly-matched 6740curly braces. 6741 6742Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which 6743speeds things up by only creating the qr//'ed expression once; if it's 6744already defined, we don't try to define it again. A speed hack. 6745 6746=cut 6747 6748use vars qw($balanced_brace_re); 6749 6750sub unbalanced { 6751 6752 # I hate using globals! 6753 $balanced_brace_re ||= qr{ 6754 ^ \{ 6755 (?: 6756 (?> [^{}] + ) # Non-parens without backtracking 6757 | 6758 (??{ $balanced_brace_re }) # Group with matching parens 6759 ) * 6760 \} $ 6761 }x; 6762 return $_[0] !~ m/$balanced_brace_re/; 6763} ## end sub unbalanced 6764 6765=head2 C<gets()> 6766 6767C<gets()> is a primitive (very primitive) routine to read continuations. 6768It was devised for reading continuations for actions. 6769it just reads more input with C<readline()> and returns it. 6770 6771=cut 6772 6773sub gets { 6774 return DB::readline("cont: "); 6775} 6776 6777=head2 C<_db_system()> - handle calls to<system()> without messing up the debugger 6778 6779The C<system()> function assumes that it can just go ahead and use STDIN and 6780STDOUT, but under the debugger, we want it to use the debugger's input and 6781outout filehandles. 6782 6783C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes 6784the debugger's IN and OUT filehandles for them. It does the C<system()> call, 6785and then puts everything back again. 6786 6787=cut 6788 6789sub _db_system { 6790 6791 # We save, change, then restore STDIN and STDOUT to avoid fork() since 6792 # some non-Unix systems can do system() but have problems with fork(). 6793 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN"); 6794 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT"); 6795 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN"); 6796 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT"); 6797 6798 # XXX: using csh or tcsh destroys sigint retvals! 6799 system(@_); 6800 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN"); 6801 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT"); 6802 close(SAVEIN); 6803 close(SAVEOUT); 6804 6805 # most of the $? crud was coping with broken cshisms 6806 if ( $? >> 8 ) { 6807 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" ); 6808 } 6809 elsif ($?) { 6810 _db_warn( 6811 "(Command died of SIG#", 6812 ( $? & 127 ), 6813 ( ( $? & 128 ) ? " -- core dumped" : "" ), 6814 ")", "\n" 6815 ); 6816 } ## end elsif ($?) 6817 6818 return $?; 6819 6820} ## end sub system 6821 6822*system = \&_db_system; 6823 6824=head1 TTY MANAGEMENT 6825 6826The subs here do some of the terminal management for multiple debuggers. 6827 6828=head2 setterm 6829 6830Top-level function called when we want to set up a new terminal for use 6831by the debugger. 6832 6833If the C<noTTY> debugger option was set, we'll either use the terminal 6834supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous> 6835to find one. If we're a forked debugger, we call C<resetterm> to try to 6836get a whole new terminal if we can. 6837 6838In either case, we set up the terminal next. If the C<ReadLine> option was 6839true, we'll get a C<Term::ReadLine> object for the current terminal and save 6840the appropriate attributes. We then 6841 6842=cut 6843 6844use vars qw($ornaments); 6845use vars qw($rl_attribs); 6846sub setterm { 6847 6848 # Load Term::Readline, but quietly; don't debug it and don't trace it. 6849 local $frame = 0; 6850 local $doret = -2; 6851 _DB__use_full_path(sub { 6852 require Term::ReadLine; 6853 }); 6854 6855 6856 # If noTTY is set, but we have a TTY name, go ahead and hook up to it. 6857 if ($notty) { 6858 if ($tty) { 6859 my ( $i, $o ) = split $tty, /,/; 6860 $o = $i unless defined $o; 6861 open( IN, '<', $i ) or die "Cannot open TTY '$i' for read: $!"; 6862 open( OUT, '>', $o ) or die "Cannot open TTY '$o' for write: $!"; 6863 $IN = \*IN; 6864 $OUT = \*OUT; 6865 _autoflush($OUT); 6866 } ## end if ($tty) 6867 6868 # We don't have a TTY - try to find one via Term::Rendezvous. 6869 else { 6870 require Term::Rendezvous; 6871 6872 # See if we have anything to pass to Term::Rendezvous. 6873 # Use $HOME/.perldbtty$$ if not. 6874 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$"; 6875 6876 # Rendezvous and get the filehandles. 6877 my $term_rv = Term::Rendezvous->new( $rv ); 6878 $IN = $term_rv->IN; 6879 $OUT = $term_rv->OUT; 6880 } ## end else [ if ($tty) 6881 } ## end if ($notty) 6882 6883 # We're a daughter debugger. Try to fork off another TTY. 6884 if ( $term_pid eq '-1' ) { # In a TTY with another debugger 6885 resetterm(2); 6886 } 6887 6888 # If we shouldn't use Term::ReadLine, don't. 6889 if ( !$rl ) { 6890 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 6891 } 6892 6893 # We're using Term::ReadLine. Get all the attributes for this terminal. 6894 else { 6895 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 6896 6897 $rl_attribs = $term->Attribs; 6898 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}' 6899 if defined $rl_attribs->{basic_word_break_characters} 6900 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1; 6901 $rl_attribs->{special_prefixes} = '$@&%'; 6902 $rl_attribs->{completer_word_break_characters} .= '$@&%'; 6903 $rl_attribs->{completion_function} = \&db_complete; 6904 } ## end else [ if (!$rl) 6905 6906 # Set up the LINEINFO filehandle. 6907 $LINEINFO = $OUT unless defined $LINEINFO; 6908 $lineinfo = $console unless defined $lineinfo; 6909 6910 $term->MinLine(2); 6911 6912 load_hist(); 6913 6914 if ( $term->Features->{setHistory} and "@hist" ne "?" ) { 6915 $term->SetHistory(@hist); 6916 } 6917 6918 # XXX Ornaments are turned on unconditionally, which is not 6919 # always a good thing. 6920 ornaments($ornaments) if defined $ornaments; 6921 $term_pid = $$; 6922} ## end sub setterm 6923 6924sub load_hist { 6925 $histfile //= option_val("HistFile", undef); 6926 return unless defined $histfile; 6927 open my $fh, "<", $histfile or return; 6928 local $/ = "\n"; 6929 @hist = (); 6930 while (<$fh>) { 6931 chomp; 6932 push @hist, $_; 6933 } 6934 close $fh; 6935} 6936 6937sub save_hist { 6938 return unless defined $histfile; 6939 eval { require File::Path } or return; 6940 eval { require File::Basename } or return; 6941 File::Path::mkpath(File::Basename::dirname($histfile)); 6942 open my $fh, ">", $histfile or die "Could not open '$histfile': $!"; 6943 $histsize //= option_val("HistSize",100); 6944 my @copy = grep { $_ ne '?' } @hist; 6945 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0; 6946 for ($start .. $#copy) { 6947 print $fh "$copy[$_]\n"; 6948 } 6949 close $fh or die "Could not write '$histfile': $!"; 6950} 6951 6952=head1 GET_FORK_TTY EXAMPLE FUNCTIONS 6953 6954When the process being debugged forks, or the process invokes a command 6955via C<system()> which starts a new debugger, we need to be able to get a new 6956C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes 6957fight over the terminal, and you can never quite be sure who's going to get the 6958input you're typing. 6959 6960C<get_fork_TTY> is a glob-aliased function which calls the real function that 6961is tasked with doing all the necessary operating system mojo to get a new 6962TTY (and probably another window) and to direct the new debugger to read and 6963write there. 6964 6965The debugger provides C<get_fork_TTY> functions which work for TCP 6966socket servers, X11, OS/2, and Mac OS X. Other systems are not 6967supported. You are encouraged to write C<get_fork_TTY> functions which 6968work for I<your> platform and contribute them. 6969 6970=head3 C<socket_get_fork_TTY> 6971 6972=cut 6973 6974sub connect_remoteport { 6975 require IO::Socket; 6976 6977 my $socket = IO::Socket::INET->new( 6978 Timeout => '10', 6979 PeerAddr => $remoteport, 6980 Proto => 'tcp', 6981 ); 6982 if ( ! $socket ) { 6983 die "Unable to connect to remote host: $remoteport\n"; 6984 } 6985 return $socket; 6986} 6987 6988sub socket_get_fork_TTY { 6989 $tty = $LINEINFO = $IN = $OUT = connect_remoteport(); 6990 6991 # Do I need to worry about setting $term? 6992 6993 reset_IN_OUT( $IN, $OUT ); 6994 return ''; 6995} 6996 6997=head3 C<xterm_get_fork_TTY> 6998 6999This function provides the C<get_fork_TTY> function for X11. If a 7000program running under the debugger forks, a new <xterm> window is opened and 7001the subsidiary debugger is directed there. 7002 7003The C<open()> call is of particular note here. We have the new C<xterm> 7004we're spawning route file number 3 to STDOUT, and then execute the C<tty> 7005command (which prints the device name of the TTY we'll want to use for input 7006and output to STDOUT, then C<sleep> for a very long time, routing this output 7007to file number 3. This way we can simply read from the <XT> filehandle (which 7008is STDOUT from the I<commands> we ran) to get the TTY we want to use. 7009 7010Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are 7011properly set up. 7012 7013=cut 7014 7015sub xterm_get_fork_TTY { 7016 ( my $name = $0 ) =~ s,^.*[/\\],,s; 7017 open XT, 7018qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\ 7019 sleep 10000000' |]; 7020 7021 # Get the output from 'tty' and clean it up a little. 7022 my $tty = <XT>; 7023 chomp $tty; 7024 7025 $pidprompt = ''; # Shown anyway in titlebar 7026 7027 # We need $term defined or we can not switch to the newly created xterm 7028 if ($tty ne '' && !defined $term) { 7029 _DB__use_full_path(sub { 7030 require Term::ReadLine; 7031 }); 7032 if ( !$rl ) { 7033 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 7034 } 7035 else { 7036 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 7037 } 7038 } 7039 # There's our new TTY. 7040 return $tty; 7041} ## end sub xterm_get_fork_TTY 7042 7043=head3 C<os2_get_fork_TTY> 7044 7045XXX It behooves an OS/2 expert to write the necessary documentation for this! 7046 7047=cut 7048 7049# This example function resets $IN, $OUT itself 7050my $c_pipe = 0; 7051sub os2_get_fork_TTY { # A simplification of the following (and works without): 7052 local $\ = ''; 7053 ( my $name = $0 ) =~ s,^.*[/\\],,s; 7054 my %opt = ( title => "Daughter Perl debugger $pids $name", 7055 ($rl ? (read_by_key => 1) : ()) ); 7056 require OS2::Process; 7057 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) } 7058 or return; 7059 $pidprompt = ''; # Shown anyway in titlebar 7060 reset_IN_OUT($in, $out); 7061 $tty = '*reset*'; 7062 return ''; # Indicate that reset_IN_OUT is called 7063} ## end sub os2_get_fork_TTY 7064 7065=head3 C<macosx_get_fork_TTY> 7066 7067The Mac OS X version uses AppleScript to tell Terminal.app to create 7068a new window. 7069 7070=cut 7071 7072# Notes about Terminal.app's AppleScript support, 7073# (aka things that might break in future OS versions). 7074# 7075# The "do script" command doesn't return a reference to the new window 7076# it creates, but since it appears frontmost and windows are enumerated 7077# front to back, we can use "first window" === "window 1". 7078# 7079# Since "do script" is implemented by supplying the argument (plus a 7080# return character) as terminal input, there's a potential race condition 7081# where the debugger could beat the shell to reading the command. 7082# To prevent this, we wait for the screen to clear before proceeding. 7083# 7084# 10.3 and 10.4: 7085# There's no direct accessor for the tty device name, so we fiddle 7086# with the window title options until it says what we want. 7087# 7088# 10.5: 7089# There _is_ a direct accessor for the tty device name, _and_ there's 7090# a new possible component of the window title (the name of the settings 7091# set). A separate version is needed. 7092 7093my @script_versions= 7094 7095 ([237, <<'__LEOPARD__'], 7096tell application "Terminal" 7097 do script "clear;exec sleep 100000" 7098 tell first tab of first window 7099 copy tty to thetty 7100 set custom title to "forked perl debugger" 7101 set title displays custom title to true 7102 repeat while (length of first paragraph of (get contents)) > 0 7103 delay 0.1 7104 end repeat 7105 end tell 7106end tell 7107thetty 7108__LEOPARD__ 7109 7110 [100, <<'__JAGUAR_TIGER__'], 7111tell application "Terminal" 7112 do script "clear;exec sleep 100000" 7113 tell first window 7114 set title displays shell path to false 7115 set title displays window size to false 7116 set title displays file name to false 7117 set title displays device name to true 7118 set title displays custom title to true 7119 set custom title to "" 7120 copy "/dev/" & name to thetty 7121 set custom title to "forked perl debugger" 7122 repeat while (length of first paragraph of (get contents)) > 0 7123 delay 0.1 7124 end repeat 7125 end tell 7126end tell 7127thetty 7128__JAGUAR_TIGER__ 7129 7130); 7131 7132sub macosx_get_fork_TTY 7133{ 7134 my($version,$script,$pipe,$tty); 7135 7136 return unless $version=$ENV{TERM_PROGRAM_VERSION}; 7137 foreach my $entry (@script_versions) { 7138 if ($version>=$entry->[0]) { 7139 $script=$entry->[1]; 7140 last; 7141 } 7142 } 7143 return unless defined($script); 7144 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script); 7145 $tty=readline($pipe); 7146 close($pipe); 7147 return unless defined($tty) && $tty =~ m(^/dev/); 7148 chomp $tty; 7149 return $tty; 7150} 7151 7152=head3 C<tmux_get_fork_TTY> 7153 7154Creates a split window for subprocesses when a process running under the 7155perl debugger in Tmux forks. 7156 7157=cut 7158 7159sub tmux_get_fork_TTY { 7160 return unless $ENV{TMUX}; 7161 7162 my $pipe; 7163 7164 my $status = open $pipe, '-|', 'tmux', 'split-window', 7165 '-P', '-F', '#{pane_tty}', 'sleep 100000'; 7166 7167 if ( !$status ) { 7168 return; 7169 } 7170 7171 my $tty = <$pipe>; 7172 close $pipe; 7173 7174 if ( $tty ) { 7175 chomp $tty; 7176 7177 if ( !defined $term ) { 7178 require Term::ReadLine; 7179 if ( !$rl ) { 7180 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 7181 } 7182 else { 7183 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 7184 } 7185 } 7186 } 7187 7188 return $tty; 7189} 7190 7191=head2 C<create_IN_OUT($flags)> 7192 7193Create a new pair of filehandles, pointing to a new TTY. If impossible, 7194try to diagnose why. 7195 7196Flags are: 7197 7198=over 4 7199 7200=item * 1 - Don't know how to create a new TTY. 7201 7202=item * 2 - Debugger has forked, but we can't get a new TTY. 7203 7204=item * 4 - standard debugger startup is happening. 7205 7206=back 7207 7208=cut 7209 7210use vars qw($fork_TTY); 7211 7212sub create_IN_OUT { # Create a window with IN/OUT handles redirected there 7213 7214 # If we know how to get a new TTY, do it! $in will have 7215 # the TTY name if get_fork_TTY works. 7216 my $in = get_fork_TTY(@_) if defined &get_fork_TTY; 7217 7218 # It used to be that 7219 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility 7220 7221 if ( not defined $in ) { 7222 my $why = shift; 7223 7224 # We don't know how. 7225 print_help(<<EOP) if $why == 1; 7226I<#########> Forked, but do not know how to create a new B<TTY>. I<#########> 7227EOP 7228 7229 # Forked debugger. 7230 print_help(<<EOP) if $why == 2; 7231I<#########> Daughter session, do not know how to change a B<TTY>. I<#########> 7232 This may be an asynchronous session, so the parent debugger may be active. 7233EOP 7234 7235 # Note that both debuggers are fighting over the same input. 7236 print_help(<<EOP) if $why != 4; 7237 Since two debuggers fight for the same TTY, input is severely entangled. 7238 7239EOP 7240 print_help(<<EOP); 7241 I know how to switch the output to a different window in xterms, OS/2 7242 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name 7243 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function 7244 B<DB::get_fork_TTY()> returning this. 7245 7246 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window 7247 by typing B<tty>, and disconnect the I<shell> from I<TTY> by S<B<sleep 1000000>>. 7248 7249EOP 7250 } ## end if (not defined $in) 7251 elsif ( $in ne '' ) { 7252 TTY($in); 7253 } 7254 else { 7255 $console = ''; # Indicate no need to open-from-the-console 7256 } 7257 undef $fork_TTY; 7258} ## end sub create_IN_OUT 7259 7260=head2 C<resetterm> 7261 7262Handles rejiggering the prompt when we've forked off a new debugger. 7263 7264If the new debugger happened because of a C<system()> that invoked a 7265program under the debugger, the arrow between the old pid and the new 7266in the prompt has I<two> dashes instead of one. 7267 7268We take the current list of pids and add this one to the end. If there 7269isn't any list yet, we make one up out of the initial pid associated with 7270the terminal and our new pid, sticking an arrow (either one-dashed or 7271two dashed) in between them. 7272 7273If C<CreateTTY> is off, or C<resetterm> was called with no arguments, 7274we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead 7275and try to do that. 7276 7277=cut 7278 7279sub resetterm { # We forked, so we need a different TTY 7280 7281 # Needs to be passed to create_IN_OUT() as well. 7282 my $in = shift; 7283 7284 # resetterm(2): got in here because of a system() starting a debugger. 7285 # resetterm(1): just forked. 7286 my $systemed = $in > 1 ? '-' : ''; 7287 7288 # If there's already a list of pids, add this to the end. 7289 if ($pids) { 7290 $pids =~ s/\]/$systemed->$$]/; 7291 } 7292 7293 # No pid list. Time to make one. 7294 else { 7295 $pids = "[$term_pid->$$]"; 7296 } 7297 7298 # The prompt we're going to be using for this debugger. 7299 $pidprompt = $pids; 7300 7301 # We now 0wnz this terminal. 7302 $term_pid = $$; 7303 7304 # Just return if we're not supposed to try to create a new TTY. 7305 return unless $CreateTTY & $in; 7306 7307 # Try to create a new IN/OUT pair. 7308 create_IN_OUT($in); 7309} ## end sub resetterm 7310 7311=head2 C<readline> 7312 7313First, we handle stuff in the typeahead buffer. If there is any, we shift off 7314the next line, print a message saying we got it, add it to the terminal 7315history (if possible), and return it. 7316 7317If there's nothing in the typeahead buffer, check the command filehandle stack. 7318If there are any filehandles there, read from the last one, and return the line 7319if we got one. If not, we pop the filehandle off and close it, and try the 7320next one up the stack. 7321 7322If we've emptied the filehandle stack, we check to see if we've got a socket 7323open, and we read that and return it if we do. If we don't, we just call the 7324core C<readline()> and return its value. 7325 7326=cut 7327 7328sub readline { 7329 7330 # Localize to prevent it from being smashed in the program being debugged. 7331 local $.; 7332 7333 # If there are stacked filehandles to read from ... 7334 # (Handle it before the typeahead, because we may call source/etc. from 7335 # the typeahead.) 7336 while (@cmdfhs) { 7337 7338 # Read from the last one in the stack. 7339 my $line = CORE::readline( $cmdfhs[-1] ); 7340 7341 # If we got a line ... 7342 defined $line 7343 ? ( print $OUT ">> $line" and return $line ) # Echo and return 7344 : close pop @cmdfhs; # Pop and close 7345 } ## end while (@cmdfhs) 7346 7347 # Pull a line out of the typeahead if there's stuff there. 7348 if (@typeahead) { 7349 7350 # How many lines left. 7351 my $left = @typeahead; 7352 7353 # Get the next line. 7354 my $got = shift @typeahead; 7355 7356 # Print a message saying we got input from the typeahead. 7357 local $\ = ''; 7358 print $OUT "auto(-$left)", shift, $got, "\n"; 7359 7360 # Add it to the terminal history (if possible). 7361 $term->AddHistory($got) 7362 if length($got) >= option_val("HistItemMinLength", 2) 7363 and defined $term->Features->{addHistory}; 7364 return $got; 7365 } ## end if (@typeahead) 7366 7367 # We really need to read some input. Turn off entry/exit trace and 7368 # return value printing. 7369 local $frame = 0; 7370 local $doret = -2; 7371 7372 # Nothing on the filehandle stack. Socket? 7373 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) { 7374 7375 # Send anything we have to send. 7376 $OUT->write( join( '', @_ ) ); 7377 7378 # Receive anything there is to receive. 7379 my $stuff = ''; 7380 my $buf; 7381 my $first_time = 1; 7382 7383 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/)) 7384 { 7385 $first_time = 0; 7386 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?" 7387 # XXX Don't know. You tell me. 7388 } 7389 7390 # What we got. 7391 return $stuff; 7392 } ## end if (ref $OUT and UNIVERSAL::isa... 7393 7394 # No socket. Just read from the terminal. 7395 else { 7396 return $term->readline(@_); 7397 } 7398} ## end sub readline 7399 7400=head1 OPTIONS SUPPORT ROUTINES 7401 7402These routines handle listing and setting option values. 7403 7404=head2 C<dump_option> - list the current value of an option setting 7405 7406This routine uses C<option_val> to look up the value for an option. 7407It cleans up escaped single-quotes and then displays the option and 7408its value. 7409 7410=cut 7411 7412sub dump_option { 7413 my ( $opt, $val ) = @_; 7414 $val = option_val( $opt, 'N/A' ); 7415 $val =~ s/([\\\'])/\\$1/g; 7416 printf $OUT "%20s = '%s'\n", $opt, $val; 7417} ## end sub dump_option 7418 7419sub options2remember { 7420 foreach my $k (@RememberOnROptions) { 7421 $option{$k} = option_val( $k, 'N/A' ); 7422 } 7423 return %option; 7424} 7425 7426=head2 C<option_val> - find the current value of an option 7427 7428This can't just be a simple hash lookup because of the indirect way that 7429the option values are stored. Some are retrieved by calling a subroutine, 7430some are just variables. 7431 7432You must supply a default value to be used in case the option isn't set. 7433 7434=cut 7435 7436sub option_val { 7437 my ( $opt, $default ) = @_; 7438 my $val; 7439 7440 # Does this option exist, and is it a variable? 7441 # If so, retrieve the value via the value in %optionVars. 7442 if ( defined $optionVars{$opt} 7443 and defined ${ $optionVars{$opt} } ) 7444 { 7445 $val = ${ $optionVars{$opt} }; 7446 } 7447 7448 # Does this option exist, and it's a subroutine? 7449 # If so, call the subroutine via the ref in %optionAction 7450 # and capture the value. 7451 elsif ( defined $optionAction{$opt} 7452 and defined &{ $optionAction{$opt} } ) 7453 { 7454 $val = &{ $optionAction{$opt} }(); 7455 } 7456 7457 # If there's an action or variable for the supplied option, 7458 # but no value was set, use the default. 7459 elsif (defined $optionAction{$opt} and not defined $option{$opt} 7460 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } ) 7461 { 7462 $val = $default; 7463 } 7464 7465 # Otherwise, do the simple hash lookup. 7466 else { 7467 $val = $option{$opt}; 7468 } 7469 7470 # If the value isn't defined, use the default. 7471 # Then return whatever the value is. 7472 $val = $default unless defined $val; 7473 $val; 7474} ## end sub option_val 7475 7476=head2 C<parse_options> 7477 7478Handles the parsing and execution of option setting/displaying commands. 7479 7480An option entered by itself is assumed to be I<set me to 1> (the default value) 7481if the option is a boolean one. If not, the user is prompted to enter a valid 7482value or to query the current value (via C<option? >). 7483 7484If C<option=value> is entered, we try to extract a quoted string from the 7485value (if it is quoted). If it's not, we just use the whole value as-is. 7486 7487We load any modules required to service this option, and then we set it: if 7488it just gets stuck in a variable, we do that; if there's a subroutine to 7489handle setting the option, we call that. 7490 7491Finally, if we're running in interactive mode, we display the effect of the 7492user's command back to the terminal, skipping this if we're setting things 7493during initialization. 7494 7495=cut 7496 7497sub parse_options { 7498 my ($s) = @_; 7499 local $\ = ''; 7500 7501 my $option; 7502 7503 # These options need a value. Don't allow them to be clobbered by accident. 7504 my %opt_needs_val = map { ( $_ => 1 ) } qw{ 7505 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize 7506 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet 7507 }; 7508 7509 while (length($s)) { 7510 my $val_defaulted; 7511 7512 # Clean off excess leading whitespace. 7513 $s =~ s/^\s+// && next; 7514 7515 # Options are always all word characters, followed by a non-word 7516 # separator. 7517 if ($s !~ s/^(\w+)(\W?)//) { 7518 print {$OUT} "Invalid option '$s'\n"; 7519 last; 7520 } 7521 my ( $opt, $sep ) = ( $1, $2 ); 7522 7523 # Make sure that such an option exists. 7524 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options ) 7525 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options ); 7526 7527 unless ($matches) { 7528 print {$OUT} "Unknown option '$opt'\n"; 7529 next; 7530 } 7531 if ($matches > 1) { 7532 print {$OUT} "Ambiguous option '$opt'\n"; 7533 next; 7534 } 7535 my $val; 7536 7537 # '?' as separator means query, but must have whitespace after it. 7538 if ( "?" eq $sep ) { 7539 if ($s =~ /\A\S/) { 7540 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ; 7541 7542 last; 7543 } 7544 7545 #&dump_option($opt); 7546 } ## end if ("?" eq $sep) 7547 7548 # Separator is whitespace (or just a carriage return). 7549 # They're going for a default, which we assume is 1. 7550 elsif ( $sep !~ /\S/ ) { 7551 $val_defaulted = 1; 7552 $val = "1"; # this is an evil default; make 'em set it! 7553 } 7554 7555 # Separator is =. Trying to set a value. 7556 elsif ( $sep eq "=" ) { 7557 7558 # If quoted, extract a quoted string. 7559 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) { 7560 my $quote = $1; 7561 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g; 7562 } 7563 7564 # Not quoted. Use the whole thing. Warn about 'option='. 7565 else { 7566 $s =~ s/^(\S*)//; 7567 $val = $1; 7568 print OUT qq(Option better cleared using $opt=""\n) 7569 unless length $val; 7570 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) 7571 7572 } ## end elsif ($sep eq "=") 7573 7574 # "Quoted" with [], <>, or {}. 7575 else { #{ to "let some poor schmuck bounce on the % key in B<vi>." 7576 my ($end) = 7577 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #} 7578 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)// 7579 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last; 7580 ( $val = $1 ) =~ s/\\([\\$end])/$1/g; 7581 } ## end else [ if ("?" eq $sep) 7582 7583 # Exclude non-booleans from getting set to 1 by default. 7584 if ( $opt_needs_val{$option} && $val_defaulted ) { 7585 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O'; 7586 print {$OUT} 7587"Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n"; 7588 next; 7589 } ## end if ($opt_needs_val{$option... 7590 7591 # Save the option value. 7592 $option{$option} = $val if defined $val; 7593 7594 # Load any module that this option requires. 7595 if ( defined($optionRequire{$option}) && defined($val) ) { 7596 eval qq{ 7597 local \$frame = 0; 7598 local \$doret = -2; 7599 require '$optionRequire{$option}'; 7600 1; 7601 } || die $@ # XXX: shouldn't happen 7602 } 7603 7604 # Set it. 7605 # Stick it in the proper variable if it goes in a variable. 7606 if (defined($optionVars{$option}) && defined($val)) { 7607 ${ $optionVars{$option} } = $val; 7608 } 7609 7610 # Call the appropriate sub if it gets set via sub. 7611 if (defined($optionAction{$option}) 7612 && defined (&{ $optionAction{$option} }) 7613 && defined ($val)) 7614 { 7615 &{ $optionAction{$option} }($val); 7616 } 7617 7618 # Not initialization - echo the value we set it to. 7619 dump_option($option) if ($OUT ne \*STDERR); 7620 } ## end while (length) 7621} ## end sub parse_options 7622 7623=head1 RESTART SUPPORT 7624 7625These routines are used to store (and restore) lists of items in environment 7626variables during a restart. 7627 7628=head2 set_list 7629 7630Set_list packages up items to be stored in a set of environment variables 7631(VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing 7632the values). Values outside the standard ASCII charset are stored by encoding 7633them as hexadecimal values. 7634 7635=cut 7636 7637sub set_list { 7638 my ( $stem, @list ) = @_; 7639 my $val; 7640 7641 # VAR_n: how many we have. Scalar assignment gets the number of items. 7642 $ENV{"${stem}_n"} = @list; 7643 7644 # Grab each item in the list, escape the backslashes, encode the non-ASCII 7645 # as hex, and then save in the appropriate VAR_0, VAR_1, etc. 7646 for my $i ( 0 .. $#list ) { 7647 $val = $list[$i]; 7648 $val =~ s/\\/\\\\/g; 7649 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) / 7650 "\\0x" . unpack('H2',$1)/xaeg; 7651 $ENV{"${stem}_$i"} = $val; 7652 } ## end for $i (0 .. $#list) 7653} ## end sub set_list 7654 7655=head2 get_list 7656 7657Reverse the set_list operation: grab VAR_n to see how many we should be getting 7658back, and then pull VAR_0, VAR_1. etc. back out. 7659 7660=cut 7661 7662sub get_list { 7663 my $stem = shift; 7664 my @list; 7665 my $n = delete $ENV{"${stem}_n"}; 7666 my $val; 7667 for my $i ( 0 .. $n - 1 ) { 7668 $val = delete $ENV{"${stem}_$i"}; 7669 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge; 7670 push @list, $val; 7671 } 7672 @list; 7673} ## end sub get_list 7674 7675=head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT 7676 7677=head2 catch() 7678 7679The C<catch()> subroutine is the essence of fast and low-impact. We simply 7680set an already-existing global scalar variable to a constant value. This 7681avoids allocating any memory possibly in the middle of something that will 7682get all confused if we do, particularly under I<unsafe signals>. 7683 7684=cut 7685 7686sub catch { 7687 $signal = 1; 7688 return; # Put nothing on the stack - malloc/free land! 7689} 7690 7691=head2 C<warn()> 7692 7693C<warn> emits a warning, by joining together its arguments and printing 7694them, with couple of fillips. 7695 7696If the composited message I<doesn't> end with a newline, we automatically 7697add C<$!> and a newline to the end of the message. The subroutine expects $OUT 7698to be set to the filehandle to be used to output warnings; it makes no 7699assumptions about what filehandles are available. 7700 7701=cut 7702 7703sub _db_warn { 7704 my ($msg) = join( "", @_ ); 7705 $msg .= ": $!\n" unless $msg =~ /\n$/; 7706 local $\ = ''; 7707 print $OUT $msg; 7708} ## end sub warn 7709 7710*warn = \&_db_warn; 7711 7712=head1 INITIALIZATION TTY SUPPORT 7713 7714=head2 C<reset_IN_OUT> 7715 7716This routine handles restoring the debugger's input and output filehandles 7717after we've tried and failed to move them elsewhere. In addition, it assigns 7718the debugger's output filehandle to $LINEINFO if it was already open there. 7719 7720=cut 7721 7722sub reset_IN_OUT { 7723 my $switch_li = $LINEINFO eq $OUT; 7724 7725 # If there's a term and it's able to get a new tty, try to get one. 7726 if ( $term and $term->Features->{newTTY} ) { 7727 ( $IN, $OUT ) = ( shift, shift ); 7728 $term->newTTY( $IN, $OUT ); 7729 } 7730 7731 # This term can't get a new tty now. Better luck later. 7732 elsif ($term) { 7733 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n"); 7734 } 7735 7736 # Set the filehndles up as they were. 7737 else { 7738 ( $IN, $OUT ) = ( shift, shift ); 7739 } 7740 7741 # Unbuffer the output filehandle. 7742 _autoflush($OUT); 7743 7744 # Point LINEINFO to the same output filehandle if it was there before. 7745 $LINEINFO = $OUT if $switch_li; 7746} ## end sub reset_IN_OUT 7747 7748=head1 OPTION SUPPORT ROUTINES 7749 7750The following routines are used to process some of the more complicated 7751debugger options. 7752 7753=head2 C<TTY> 7754 7755Sets the input and output filehandles to the specified files or pipes. 7756If the terminal supports switching, we go ahead and do it. If not, and 7757there's already a terminal in place, we save the information to take effect 7758on restart. 7759 7760If there's no terminal yet (for instance, during debugger initialization), 7761we go ahead and set C<$console> and C<$tty> to the file indicated. 7762 7763=cut 7764 7765sub TTY { 7766 7767 if ( @_ and $term and $term->Features->{newTTY} ) { 7768 7769 # This terminal supports switching to a new TTY. 7770 # Can be a list of two files, or on string containing both names, 7771 # comma-separated. 7772 # XXX Should this perhaps be an assignment from @_? 7773 my ( $in, $out ) = shift; 7774 if ( $in =~ /,/ ) { 7775 7776 # Split list apart if supplied. 7777 ( $in, $out ) = split /,/, $in, 2; 7778 } 7779 else { 7780 7781 # Use the same file for both input and output. 7782 $out = $in; 7783 } 7784 7785 # Open file onto the debugger's filehandles, if you can. 7786 open IN, '<', $in or die "cannot open '$in' for read: $!"; 7787 open OUT, '>', $out or die "cannot open '$out' for write: $!"; 7788 7789 # Swap to the new filehandles. 7790 reset_IN_OUT( \*IN, \*OUT ); 7791 7792 # Save the setting for later. 7793 return $tty = $in; 7794 } ## end if (@_ and $term and $term... 7795 7796 # Terminal doesn't support new TTY, or doesn't support readline. 7797 # Can't do it now, try restarting. 7798 if ($term and @_) { 7799 _db_warn("Too late to set TTY, enabled on next 'R'!\n"); 7800 } 7801 7802 # Useful if done through PERLDB_OPTS: 7803 $console = $tty = shift if @_; 7804 7805 # Return whatever the TTY is. 7806 $tty or $console; 7807} ## end sub TTY 7808 7809=head2 C<noTTY> 7810 7811Sets the C<$notty> global, controlling whether or not the debugger tries to 7812get a terminal to read from. If called after a terminal is already in place, 7813we save the value to use it if we're restarted. 7814 7815=cut 7816 7817sub noTTY { 7818 if ($term) { 7819 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_; 7820 } 7821 $notty = shift if @_; 7822 $notty; 7823} ## end sub noTTY 7824 7825=head2 C<ReadLine> 7826 7827Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub> 7828(essentially, no C<readline> processing on this I<terminal>). Otherwise, we 7829use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save 7830the value in case a restart is done so we can change it then. 7831 7832=cut 7833 7834sub ReadLine { 7835 if ($term) { 7836 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_; 7837 } 7838 $rl = shift if @_; 7839 $rl; 7840} ## end sub ReadLine 7841 7842=head2 C<RemotePort> 7843 7844Sets the port that the debugger will try to connect to when starting up. 7845If the terminal's already been set up, we can't do it, but we remember the 7846setting in case the user does a restart. 7847 7848=cut 7849 7850sub RemotePort { 7851 if ($term) { 7852 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_; 7853 } 7854 $remoteport = shift if @_; 7855 $remoteport; 7856} ## end sub RemotePort 7857 7858=head2 C<tkRunning> 7859 7860Checks with the terminal to see if C<Tk> is running, and returns true or 7861false. Returns false if the current terminal doesn't support C<readline>. 7862 7863=cut 7864 7865sub tkRunning { 7866 if ( ${ $term->Features }{tkRunning} ) { 7867 return $term->tkRunning(@_); 7868 } 7869 else { 7870 local $\ = ''; 7871 print $OUT "tkRunning not supported by current ReadLine package.\n"; 7872 0; 7873 } 7874} ## end sub tkRunning 7875 7876=head2 C<NonStop> 7877 7878Sets nonstop mode. If a terminal's already been set up, it's too late; the 7879debugger remembers the setting in case you restart, though. 7880 7881=cut 7882 7883sub NonStop { 7884 if ($term) { 7885 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n") 7886 if @_; 7887 } 7888 $runnonstop = shift if @_; 7889 $runnonstop; 7890} ## end sub NonStop 7891 7892sub DollarCaretP { 7893 if ($term) { 7894 _db_warn("Some flag changes could not take effect until next 'R'!\n") 7895 if @_; 7896 } 7897 $^P = parse_DollarCaretP_flags(shift) if @_; 7898 expand_DollarCaretP_flags($^P); 7899} 7900 7901=head2 C<pager> 7902 7903Set up the C<$pager> variable. Adds a pipe to the front unless there's one 7904there already. 7905 7906=cut 7907 7908sub pager { 7909 if (@_) { 7910 $pager = shift; 7911 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/; 7912 } 7913 $pager; 7914} ## end sub pager 7915 7916=head2 C<shellBang> 7917 7918Sets the shell escape command, and generates a printable copy to be used 7919in the help. 7920 7921=cut 7922 7923sub shellBang { 7924 7925 # If we got an argument, meta-quote it, and add '\b' if it 7926 # ends in a word character. 7927 if (@_) { 7928 $sh = quotemeta shift; 7929 $sh .= "\\b" if $sh =~ /\w$/; 7930 } 7931 7932 # Generate the printable version for the help: 7933 $psh = $sh; # copy it 7934 $psh =~ s/\\b$//; # Take off trailing \b if any 7935 $psh =~ s/\\(.)/$1/g; # De-escape 7936 $psh; # return the printable version 7937} ## end sub shellBang 7938 7939=head2 C<ornaments> 7940 7941If the terminal has its own ornaments, fetch them. Otherwise accept whatever 7942was passed as the argument. (This means you can't override the terminal's 7943ornaments.) 7944 7945=cut 7946 7947sub ornaments { 7948 if ( defined $term ) { 7949 7950 # We don't want to show warning backtraces, but we do want die() ones. 7951 local $warnLevel = 0; 7952 local $dieLevel = 1; 7953 7954 # No ornaments if the terminal doesn't support them. 7955 if (not $term->Features->{ornaments}) { 7956 return ''; 7957 } 7958 7959 return (eval { $term->ornaments(@_) } || ''); 7960 } 7961 7962 # Use what was passed in if we can't determine it ourselves. 7963 else { 7964 $ornaments = shift; 7965 7966 return $ornaments; 7967 } 7968 7969} ## end sub ornaments 7970 7971=head2 C<recallCommand> 7972 7973Sets the recall command, and builds a printable version which will appear in 7974the help text. 7975 7976=cut 7977 7978sub recallCommand { 7979 7980 # If there is input, metaquote it. Add '\b' if it ends with a word 7981 # character. 7982 if (@_) { 7983 $rc = quotemeta shift; 7984 $rc .= "\\b" if $rc =~ /\w$/; 7985 } 7986 7987 # Build it into a printable version. 7988 $prc = $rc; # Copy it 7989 $prc =~ s/\\b$//; # Remove trailing \b 7990 $prc =~ s/\\(.)/$1/g; # Remove escapes 7991 return $prc; # Return the printable version 7992} ## end sub recallCommand 7993 7994=head2 C<LineInfo> - where the line number information goes 7995 7996Called with no arguments, returns the file or pipe that line info should go to. 7997 7998Called with an argument (a file or a pipe), it opens that onto the 7999C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the 8000file or pipe again to the caller. 8001 8002=cut 8003 8004sub LineInfo { 8005 if (@_) { 8006 $lineinfo = shift; 8007 8008 # If this is a valid "thing to be opened for output", tack a 8009 # '>' onto the front. 8010 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo"; 8011 8012 # If this is a pipe, the stream points to a client editor. 8013 $client_editor = ( $stream =~ /^\|/ ); 8014 8015 my $new_lineinfo_fh; 8016 # Open it up and unbuffer it. 8017 open ($new_lineinfo_fh , $stream ) 8018 or _db_warn("Cannot open '$stream' for write"); 8019 $LINEINFO = $new_lineinfo_fh; 8020 _autoflush($LINEINFO); 8021 } 8022 8023 return $lineinfo; 8024} ## end sub LineInfo 8025 8026=head1 COMMAND SUPPORT ROUTINES 8027 8028These subroutines provide functionality for various commands. 8029 8030=head2 C<list_modules> 8031 8032For the C<M> command: list modules loaded and their versions. 8033Essentially just runs through the keys in %INC, picks each package's 8034C<$VERSION> variable, gets the file name, and formats the information 8035for output. 8036 8037=cut 8038 8039sub list_modules { # versions 8040 my %version; 8041 my $file; 8042 8043 # keys are the "as-loaded" name, values are the fully-qualified path 8044 # to the file itself. 8045 for ( keys %INC ) { 8046 $file = $_; # get the module name 8047 s,\.p[lm]$,,i; # remove '.pl' or '.pm' 8048 s,/,::,g; # change '/' to '::' 8049 s/^perl5db$/DB/; # Special case: debugger 8050 # moves to package DB 8051 s/^Term::ReadLine::readline$/readline/; # simplify readline 8052 8053 # If the package has a $VERSION package global (as all good packages 8054 # should!) decode it and save as partial message. 8055 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } }; 8056 if ( defined $pkg_version ) { 8057 $version{$file} = "$pkg_version from "; 8058 } 8059 8060 # Finish up the message with the file the package came from. 8061 $version{$file} .= $INC{$file}; 8062 } ## end for (keys %INC) 8063 8064 # Hey, dumpit() formats a hash nicely, so why not use it? 8065 dumpit( $OUT, \%version ); 8066} ## end sub list_modules 8067 8068=head2 C<sethelp()> 8069 8070Sets up the monster string used to format and print the help. 8071 8072=head3 HELP MESSAGE FORMAT 8073 8074The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments> 8075(C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly 8076easy to parse and portable, but which still allows the help to be a little 8077nicer than just plain text. 8078 8079Essentially, you define the command name (usually marked up with C<< B<> >> 8080and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a 8081newline. The descriptive text can also be marked up in the same way. If you 8082need to continue the descriptive text to another line, start that line with 8083just tabs and then enter the marked-up text. 8084 8085If you are modifying the help text, I<be careful>. The help-string parser is 8086not very sophisticated, and if you don't follow these rules it will mangle the 8087help beyond hope until you fix the string. 8088 8089=cut 8090 8091use vars qw($pre580_help); 8092use vars qw($pre580_summary); 8093 8094sub sethelp { 8095 8096 # XXX: make sure there are tabs between the command and explanation, 8097 # or print_help will screw up your formatting if you have 8098 # eeevil ornaments enabled. This is an insane mess. 8099 8100 $help = " 8101Help is currently only available for the new 5.8 command set. 8102No help is available for the old command set. 8103We assume you know what you're doing if you switch to it. 8104 8105B<T> Stack trace. 8106B<s> [I<expr>] Single step [in I<expr>]. 8107B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. 8108<B<CR>> Repeat last B<n> or B<s> command. 8109B<r> Return from current subroutine. 8110B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint 8111 at the specified position. 8112B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. 8113B<l> I<min>B<->I<max> List lines I<min> through I<max>. 8114B<l> I<line> List single I<line>. 8115B<l> I<subname> List first window of lines from subroutine. 8116B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. 8117B<l> List next window of lines. 8118B<-> List previous window of lines. 8119B<v> [I<line>] View window around I<line>. 8120B<.> Return to the executed line. 8121B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. 8122 I<filename> may be either the full name of the file, or a regular 8123 expression matching the full file name: 8124 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. 8125 Evals (with saved bodies) are considered to be filenames: 8126 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval 8127 (in the order of execution). 8128B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. 8129B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. 8130B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions. 8131B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. 8132B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth). 8133B<t> [I<n>] I<expr> Trace through execution of I<expr>. 8134B<b> Sets breakpoint on current line) 8135B<b> [I<line>] [I<condition>] 8136 Set breakpoint; I<line> defaults to the current execution line; 8137 I<condition> breaks if it evaluates to true, defaults to '1'. 8138B<b> I<subname> [I<condition>] 8139 Set breakpoint at first line of subroutine. 8140B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. 8141B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file. 8142B<b> B<postpone> I<subname> [I<condition>] 8143 Set breakpoint at first line of subroutine after 8144 it is compiled. 8145B<b> B<compile> I<subname> 8146 Stop after the subroutine is compiled. 8147B<B> [I<line>] Delete the breakpoint for I<line>. 8148B<B> I<*> Delete all breakpoints. 8149B<a> [I<line>] I<command> 8150 Set an action to be done before the I<line> is executed; 8151 I<line> defaults to the current execution line. 8152 Sequence is: check for breakpoint/watchpoint, print line 8153 if necessary, do action, prompt user if necessary, 8154 execute line. 8155B<a> Does nothing 8156B<A> [I<line>] Delete the action for I<line>. 8157B<A> I<*> Delete all actions. 8158B<w> I<expr> Add a global watch-expression. 8159B<w> Does nothing 8160B<W> I<expr> Delete a global watch-expression. 8161B<W> I<*> Delete all watch-expressions. 8162B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). 8163 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. 8164B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". 8165B<x> I<expr> Evals expression in list context, dumps the result. 8166B<m> I<expr> Evals expression in list context, prints methods callable 8167 on the first element of the result. 8168B<m> I<class> Prints methods callable via the given class. 8169B<M> Show versions of loaded modules. 8170B<i> I<class> Prints nested parents of given class. 8171B<e> Display current thread id. 8172B<E> Display all thread ids the current one will be identified: <n>. 8173B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8174 8175B<<> ? List Perl commands to run before each prompt. 8176B<<> I<expr> Define Perl command to run before each prompt. 8177B<<<> I<expr> Add to the list of Perl commands to run before each prompt. 8178B<< *> Delete the list of perl commands to run before each prompt. 8179B<>> ? List Perl commands to run after each prompt. 8180B<>> I<expr> Define Perl command to run after each prompt. 8181B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. 8182B<>>B< *> Delete the list of Perl commands to run after each prompt. 8183B<{> I<db_command> Define debugger command to run before each prompt. 8184B<{> ? List debugger commands to run before each prompt. 8185B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. 8186B<{ *> Delete the list of debugger commands to run before each prompt. 8187B<$prc> I<number> Redo a previous command (default previous command). 8188B<$prc> I<-number> Redo number'th-to-last command. 8189B<$prc> I<pattern> Redo last command that started with I<pattern>. 8190 See 'B<O> I<recallCommand>' too. 8191B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" 8192 . ( 8193 $rc eq $sh 8194 ? "" 8195 : " 8196B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." 8197 ) . " 8198 See 'B<O> I<shellBang>' too. 8199B<source> I<file> Execute I<file> containing debugger commands (may nest). 8200B<save> I<file> Save current debugger session (actual history) to I<file>. 8201B<rerun> Rerun session to current position. 8202B<rerun> I<n> Rerun session to numbered command. 8203B<rerun> I<-n> Rerun session to number'th-to-last command. 8204B<H> I<-number> Display last number commands (default all). 8205B<H> I<*> Delete complete history. 8206B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. 8207B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. 8208B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well. 8209B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. 8210I<command> Execute as a perl statement in current package. 8211B<R> Poor man's restart of the debugger, some of debugger state 8212 and command-line options may be lost. 8213 Currently the following settings are preserved: 8214 history, breakpoints and actions, debugger B<O>ptions 8215 and the following command-line options: I<-w>, I<-I>, I<-e>. 8216 8217B<o> [I<opt>] ... Set boolean option to true 8218B<o> [I<opt>B<?>] Query options 8219B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... 8220 Set options. Use quotes if spaces in value. 8221 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; 8222 I<pager> program for output of \"|cmd\"; 8223 I<tkRunning> run Tk while prompting (with ReadLine); 8224 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; 8225 I<inhibit_exit> Allows stepping off the end of the script. 8226 I<ImmediateStop> Debugger should stop as early as possible. 8227 I<RemotePort> Remote hostname:port for remote debugging 8228 The following options affect what happens with B<V>, B<X>, and B<x> commands: 8229 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); 8230 I<compactDump>, I<veryCompact> change style of array and hash dump; 8231 I<globPrint> whether to print contents of globs; 8232 I<DumpDBFiles> dump arrays holding debugged files; 8233 I<DumpPackages> dump symbol tables of packages; 8234 I<DumpReused> dump contents of \"reused\" addresses; 8235 I<quote>, I<HighBit>, I<undefPrint> change style of string dump; 8236 I<bareStringify> Do not print the overload-stringified value; 8237 Other options include: 8238 I<PrintRet> affects printing of return value after B<r> command, 8239 I<frame> affects printing messages on subroutine entry/exit. 8240 I<AutoTrace> affects printing messages on possible breaking points. 8241 I<maxTraceLen> gives max length of evals/args listed in stack trace. 8242 I<ornaments> affects screen appearance of the command line. 8243 I<CreateTTY> bits control attempts to create a new TTY on events: 8244 1: on fork() 2: debugger is started inside debugger 8245 4: on startup 8246 During startup options are initialized from \$ENV{PERLDB_OPTS}. 8247 You can put additional initialization options I<TTY>, I<noTTY>, 8248 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use 8249 B<R> after you set them). 8250 8251B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. 8252B<h> Summary of debugger commands. 8253B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. 8254B<h h> Long help for debugger commands 8255B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the 8256 named Perl I<manpage>, or on B<$doccmd> itself if omitted. 8257 Set B<\$DB::doccmd> to change viewer. 8258 8259Type '|h h' for a paged display if this was too hard to read. 8260 8261"; # Fix balance of vi % matching: }}}} 8262 8263 # note: tabs in the following section are not-so-helpful 8264 $summary = <<"END_SUM"; 8265I<List/search source lines:> I<Control script execution:> 8266 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace 8267 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] 8268 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs 8269 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> 8270 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine 8271 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position 8272I<Debugger controls:> B<L> List break/watch/actions 8273 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr] 8274 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint 8275 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints 8276 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line 8277 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions 8278 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression 8279 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs 8280 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess 8281 B<q> or B<^D> Quit B<R> Attempt a restart 8282I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> 8283 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. 8284 B<p> I<expr> Print expression (uses script's current package). 8285 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern 8286 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. 8287 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree. 8288 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8289 B<e> Display thread id B<E> Display all thread ids. 8290For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. 8291END_SUM 8292 8293 # ')}}; # Fix balance of vi % matching 8294 8295 # and this is really numb... 8296 $pre580_help = " 8297B<T> Stack trace. 8298B<s> [I<expr>] Single step [in I<expr>]. 8299B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. 8300B<CR>> Repeat last B<n> or B<s> command. 8301B<r> Return from current subroutine. 8302B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint 8303 at the specified position. 8304B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. 8305B<l> I<min>B<->I<max> List lines I<min> through I<max>. 8306B<l> I<line> List single I<line>. 8307B<l> I<subname> List first window of lines from subroutine. 8308B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. 8309B<l> List next window of lines. 8310B<-> List previous window of lines. 8311B<w> [I<line>] List window around I<line>. 8312B<.> Return to the executed line. 8313B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. 8314 I<filename> may be either the full name of the file, or a regular 8315 expression matching the full file name: 8316 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. 8317 Evals (with saved bodies) are considered to be filenames: 8318 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval 8319 (in the order of execution). 8320B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. 8321B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. 8322B<L> List all breakpoints and actions. 8323B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. 8324B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) . 8325B<t> [I<n>] I<expr> Trace through execution of I<expr>. 8326B<b> [I<line>] [I<condition>] 8327 Set breakpoint; I<line> defaults to the current execution line; 8328 I<condition> breaks if it evaluates to true, defaults to '1'. 8329B<b> I<subname> [I<condition>] 8330 Set breakpoint at first line of subroutine. 8331B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. 8332B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file. 8333B<b> B<postpone> I<subname> [I<condition>] 8334 Set breakpoint at first line of subroutine after 8335 it is compiled. 8336B<b> B<compile> I<subname> 8337 Stop after the subroutine is compiled. 8338B<d> [I<line>] Delete the breakpoint for I<line>. 8339B<D> Delete all breakpoints. 8340B<a> [I<line>] I<command> 8341 Set an action to be done before the I<line> is executed; 8342 I<line> defaults to the current execution line. 8343 Sequence is: check for breakpoint/watchpoint, print line 8344 if necessary, do action, prompt user if necessary, 8345 execute line. 8346B<a> [I<line>] Delete the action for I<line>. 8347B<A> Delete all actions. 8348B<W> I<expr> Add a global watch-expression. 8349B<W> Delete all watch-expressions. 8350B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). 8351 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. 8352B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". 8353B<x> I<expr> Evals expression in list context, dumps the result. 8354B<m> I<expr> Evals expression in list context, prints methods callable 8355 on the first element of the result. 8356B<m> I<class> Prints methods callable via the given class. 8357 8358B<<> ? List Perl commands to run before each prompt. 8359B<<> I<expr> Define Perl command to run before each prompt. 8360B<<<> I<expr> Add to the list of Perl commands to run before each prompt. 8361B<>> ? List Perl commands to run after each prompt. 8362B<>> I<expr> Define Perl command to run after each prompt. 8363B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. 8364B<{> I<db_command> Define debugger command to run before each prompt. 8365B<{> ? List debugger commands to run before each prompt. 8366B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. 8367B<$prc> I<number> Redo a previous command (default previous command). 8368B<$prc> I<-number> Redo number'th-to-last command. 8369B<$prc> I<pattern> Redo last command that started with I<pattern>. 8370 See 'B<O> I<recallCommand>' too. 8371B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" 8372 . ( 8373 $rc eq $sh 8374 ? "" 8375 : " 8376B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." 8377 ) . " 8378 See 'B<O> I<shellBang>' too. 8379B<source> I<file> Execute I<file> containing debugger commands (may nest). 8380B<H> I<-number> Display last number commands (default all). 8381B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. 8382B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. 8383B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well. 8384B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. 8385I<command> Execute as a perl statement in current package. 8386B<v> Show versions of loaded modules. 8387B<R> Poor man's restart of the debugger, some of debugger state 8388 and command-line options may be lost. 8389 Currently the following settings are preserved: 8390 history, breakpoints and actions, debugger B<O>ptions 8391 and the following command-line options: I<-w>, I<-I>, I<-e>. 8392 8393B<O> [I<opt>] ... Set boolean option to true 8394B<O> [I<opt>B<?>] Query options 8395B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... 8396 Set options. Use quotes if spaces in value. 8397 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; 8398 I<pager> program for output of \"|cmd\"; 8399 I<tkRunning> run Tk while prompting (with ReadLine); 8400 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; 8401 I<inhibit_exit> Allows stepping off the end of the script. 8402 I<ImmediateStop> Debugger should stop as early as possible. 8403 I<RemotePort> Remote hostname:port for remote debugging 8404 The following options affect what happens with B<V>, B<X>, and B<x> commands: 8405 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); 8406 I<compactDump>, I<veryCompact> change style of array and hash dump; 8407 I<globPrint> whether to print contents of globs; 8408 I<DumpDBFiles> dump arrays holding debugged files; 8409 I<DumpPackages> dump symbol tables of packages; 8410 I<DumpReused> dump contents of \"reused\" addresses; 8411 I<quote>, I<HighBit>, I<undefPrint> change style of string dump; 8412 I<bareStringify> Do not print the overload-stringified value; 8413 Other options include: 8414 I<PrintRet> affects printing of return value after B<r> command, 8415 I<frame> affects printing messages on subroutine entry/exit. 8416 I<AutoTrace> affects printing messages on possible breaking points. 8417 I<maxTraceLen> gives max length of evals/args listed in stack trace. 8418 I<ornaments> affects screen appearance of the command line. 8419 I<CreateTTY> bits control attempts to create a new TTY on events: 8420 1: on fork() 2: debugger is started inside debugger 8421 4: on startup 8422 During startup options are initialized from \$ENV{PERLDB_OPTS}. 8423 You can put additional initialization options I<TTY>, I<noTTY>, 8424 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use 8425 B<R> after you set them). 8426 8427B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. 8428B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. 8429B<h h> Summary of debugger commands. 8430B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the 8431 named Perl I<manpage>, or on B<$doccmd> itself if omitted. 8432 Set B<\$DB::doccmd> to change viewer. 8433 8434Type '|h' for a paged display if this was too hard to read. 8435 8436"; # Fix balance of vi % matching: }}}} 8437 8438 # note: tabs in the following section are not-so-helpful 8439 $pre580_summary = <<"END_SUM"; 8440I<List/search source lines:> I<Control script execution:> 8441 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace 8442 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] 8443 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs 8444 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> 8445 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine 8446 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position 8447I<Debugger controls:> B<L> List break/watch/actions 8448 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr] 8449 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint 8450 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints 8451 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line 8452 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression 8453 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch 8454 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess 8455 B<q> or B<^D> Quit B<R> Attempt a restart 8456I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> 8457 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. 8458 B<p> I<expr> Print expression (uses script's current package). 8459 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern 8460 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. 8461 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". 8462 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8463For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. 8464END_SUM 8465 8466 # ')}}; # Fix balance of vi % matching 8467 8468} ## end sub sethelp 8469 8470=head2 C<print_help()> 8471 8472Most of what C<print_help> does is just text formatting. It finds the 8473C<B> and C<I> ornaments, cleans them off, and substitutes the proper 8474terminal control characters to simulate them (courtesy of 8475C<Term::ReadLine::TermCap>). 8476 8477=cut 8478 8479sub print_help { 8480 my $help_str = shift; 8481 8482 # Restore proper alignment destroyed by eeevil I<> and B<> 8483 # ornaments: A pox on both their houses! 8484 # 8485 # A help command will have everything up to and including 8486 # the first tab sequence padded into a field 16 (or if indented 20) 8487 # wide. If it's wider than that, an extra space will be added. 8488 $help_str =~ s{ 8489 ^ # only matters at start of line 8490 ( \ {4} | \t )* # some subcommands are indented 8491 ( < ? # so <CR> works 8492 [BI] < [^\t\n] + ) # find an eeevil ornament 8493 ( \t+ ) # original separation, discarded 8494 ( .* ) # this will now start (no earlier) than 8495 # column 16 8496 } { 8497 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4); 8498 my $clean = $command; 8499 $clean =~ s/[BI]<([^>]*)>/$1/g; 8500 8501 # replace with this whole string: 8502 ($leadwhite ? " " x 4 : "") 8503 . $command 8504 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ") 8505 . $text; 8506 8507 }mgex; 8508 8509 $help_str =~ s{ # handle bold ornaments 8510 B < ( [^>] + | > ) > 8511 } { 8512 $Term::ReadLine::TermCap::rl_term_set[2] 8513 . $1 8514 . $Term::ReadLine::TermCap::rl_term_set[3] 8515 }gex; 8516 8517 $help_str =~ s{ # handle italic ornaments 8518 I < ( [^>] + | > ) > 8519 } { 8520 $Term::ReadLine::TermCap::rl_term_set[0] 8521 . $1 8522 . $Term::ReadLine::TermCap::rl_term_set[1] 8523 }gex; 8524 8525 local $\ = ''; 8526 print {$OUT} $help_str; 8527 8528 return; 8529} ## end sub print_help 8530 8531=head2 C<fix_less> 8532 8533This routine does a lot of gyrations to be sure that the pager is C<less>. 8534It checks for C<less> masquerading as C<more> and records the result in 8535C<$fixed_less> so we don't have to go through doing the stats again. 8536 8537=cut 8538 8539use vars qw($fixed_less); 8540 8541sub _calc_is_less { 8542 if ($pager =~ /\bless\b/) 8543 { 8544 return 1; 8545 } 8546 elsif ($pager =~ /\bmore\b/) 8547 { 8548 # Nope, set to more. See what's out there. 8549 my @st_more = stat('/usr/bin/more'); 8550 my @st_less = stat('/usr/bin/less'); 8551 8552 # is it really less, pretending to be more? 8553 return ( 8554 @st_more 8555 && @st_less 8556 && $st_more[0] == $st_less[0] 8557 && $st_more[1] == $st_less[1] 8558 ); 8559 } 8560 else { 8561 return; 8562 } 8563} 8564 8565sub fix_less { 8566 8567 # We already know if this is set. 8568 return if $fixed_less; 8569 8570 # changes environment! 8571 # 'r' added so we don't do (slow) stats again. 8572 $fixed_less = 1 if _calc_is_less(); 8573 8574 return; 8575} ## end sub fix_less 8576 8577=head1 DIE AND WARN MANAGEMENT 8578 8579=head2 C<diesignal> 8580 8581C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying 8582to debug a debugger problem. 8583 8584It does its best to report the error that occurred, and then forces the 8585program, debugger, and everything to die. 8586 8587=cut 8588 8589sub diesignal { 8590 8591 # No entry/exit messages. 8592 local $frame = 0; 8593 8594 # No return value prints. 8595 local $doret = -2; 8596 8597 # set the abort signal handling to the default (just terminate). 8598 $SIG{'ABRT'} = 'DEFAULT'; 8599 8600 # If we enter the signal handler recursively, kill myself with an 8601 # abort signal (so we just terminate). 8602 kill 'ABRT', $$ if $panic++; 8603 8604 # If we can show detailed info, do so. 8605 if ( defined &Carp::longmess ) { 8606 8607 # Don't recursively enter the warn handler, since we're carping. 8608 local $SIG{__WARN__} = ''; 8609 8610 # Skip two levels before reporting traceback: we're skipping 8611 # mydie and confess. 8612 local $Carp::CarpLevel = 2; # mydie + confess 8613 8614 # Tell us all about it. 8615 _db_warn( Carp::longmess("Signal @_") ); 8616 } 8617 8618 # No Carp. Tell us about the signal as best we can. 8619 else { 8620 local $\ = ''; 8621 print $DB::OUT "Got signal @_\n"; 8622 } 8623 8624 # Drop dead. 8625 kill 'ABRT', $$; 8626} ## end sub diesignal 8627 8628=head2 C<dbwarn> 8629 8630The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to 8631be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>. 8632 8633=cut 8634 8635sub dbwarn { 8636 8637 # No entry/exit trace. 8638 local $frame = 0; 8639 8640 # No return value printing. 8641 local $doret = -2; 8642 8643 # Turn off warn and die handling to prevent recursive entries to this 8644 # routine. 8645 local $SIG{__WARN__} = ''; 8646 local $SIG{__DIE__} = ''; 8647 8648 # Load Carp if we can. If $^S is false (current thing being compiled isn't 8649 # done yet), we may not be able to do a require. 8650 eval { require Carp } 8651 if defined $^S; # If error/warning during compilation, 8652 # require may be broken. 8653 8654 # Use the core warn() unless Carp loaded OK. 8655 CORE::warn( @_, 8656 "\nCannot print stack trace, load with -MCarp option to see stack" ), 8657 return 8658 unless defined &Carp::longmess; 8659 8660 # Save the current values of $single and $trace, and then turn them off. 8661 my ( $mysingle, $mytrace ) = ( $single, $trace ); 8662 $single = 0; 8663 $trace = 0; 8664 8665 # We can call Carp::longmess without its being "debugged" (which we 8666 # don't want - we just want to use it!). Capture this for later. 8667 my $mess = Carp::longmess(@_); 8668 8669 # Restore $single and $trace to their original values. 8670 ( $single, $trace ) = ( $mysingle, $mytrace ); 8671 8672 # Use the debugger's own special way of printing warnings to print 8673 # the stack trace message. 8674 _db_warn($mess); 8675} ## end sub dbwarn 8676 8677=head2 C<dbdie> 8678 8679The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace 8680by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off 8681single stepping and tracing during the call to C<Carp::longmess> to avoid 8682debugging it - we just want to use it. 8683 8684If C<dieLevel> is zero, we let the program being debugged handle the 8685exceptions. If it's 1, you get backtraces for any exception. If it's 2, 8686the debugger takes over all exception handling, printing a backtrace and 8687displaying the exception via its C<dbwarn()> routine. 8688 8689=cut 8690 8691sub dbdie { 8692 local $frame = 0; 8693 local $doret = -2; 8694 local $SIG{__DIE__} = ''; 8695 local $SIG{__WARN__} = ''; 8696 if ( $dieLevel > 2 ) { 8697 local $SIG{__WARN__} = \&dbwarn; 8698 _db_warn(@_); # Yell no matter what 8699 return; 8700 } 8701 if ( $dieLevel < 2 ) { 8702 die @_ if $^S; # in eval propagate 8703 } 8704 8705 # The code used to check $^S to see if compilation of the current thing 8706 # hadn't finished. We don't do it anymore, figuring eval is pretty stable. 8707 eval { require Carp }; 8708 8709 die( @_, 8710 "\nCannot print stack trace, load with -MCarp option to see stack" ) 8711 unless defined &Carp::longmess; 8712 8713 # We do not want to debug this chunk (automatic disabling works 8714 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off, 8715 # get the stack trace from Carp::longmess (if possible), restore $signal 8716 # and $trace, and then die with the stack trace. 8717 my ( $mysingle, $mytrace ) = ( $single, $trace ); 8718 $single = 0; 8719 $trace = 0; 8720 my $mess = "@_"; 8721 { 8722 8723 package Carp; # Do not include us in the list 8724 eval { $mess = Carp::longmess(@_); }; 8725 } 8726 ( $single, $trace ) = ( $mysingle, $mytrace ); 8727 die $mess; 8728} ## end sub dbdie 8729 8730=head2 C<warnlevel()> 8731 8732Set the C<$DB::warnLevel> variable that stores the value of the 8733C<warnLevel> option. Calling C<warnLevel()> with a positive value 8734results in the debugger taking over all warning handlers. Setting 8735C<warnLevel> to zero leaves any warning handlers set up by the program 8736being debugged in place. 8737 8738=cut 8739 8740sub warnLevel { 8741 if (@_) { 8742 my $prevwarn = $SIG{__WARN__} unless $warnLevel; 8743 $warnLevel = shift; 8744 if ($warnLevel) { 8745 $SIG{__WARN__} = \&DB::dbwarn; 8746 } 8747 elsif ($prevwarn) { 8748 $SIG{__WARN__} = $prevwarn; 8749 } else { 8750 undef $SIG{__WARN__}; 8751 } 8752 } ## end if (@_) 8753 $warnLevel; 8754} ## end sub warnLevel 8755 8756=head2 C<dielevel> 8757 8758Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the 8759C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to 8760zero lets you use your own C<die()> handler. 8761 8762=cut 8763 8764sub dieLevel { 8765 local $\ = ''; 8766 if (@_) { 8767 my $prevdie = $SIG{__DIE__} unless $dieLevel; 8768 $dieLevel = shift; 8769 if ($dieLevel) { 8770 8771 # Always set it to dbdie() for non-zero values. 8772 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2; 8773 8774 # No longer exists, so don't try to use it. 8775 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2; 8776 8777 # If we've finished initialization, mention that stack dumps 8778 # are enabled, If dieLevel is 1, we won't stack dump if we die 8779 # in an eval(). 8780 print $OUT "Stack dump during die enabled", 8781 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n" 8782 if $I_m_init; 8783 8784 # XXX This is probably obsolete, given that diehard() is gone. 8785 print $OUT "Dump printed too.\n" if $dieLevel > 2; 8786 } ## end if ($dieLevel) 8787 8788 # Put the old one back if there was one. 8789 elsif ($prevdie) { 8790 $SIG{__DIE__} = $prevdie; 8791 print $OUT "Default die handler restored.\n"; 8792 } else { 8793 undef $SIG{__DIE__}; 8794 print $OUT "Die handler removed.\n"; 8795 } 8796 } ## end if (@_) 8797 $dieLevel; 8798} ## end sub dieLevel 8799 8800=head2 C<signalLevel> 8801 8802Number three in a series: set C<signalLevel> to zero to keep your own 8803signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger 8804takes over and handles them with C<DB::diesignal()>. 8805 8806=cut 8807 8808sub signalLevel { 8809 if (@_) { 8810 my $prevsegv = $SIG{SEGV} unless $signalLevel; 8811 my $prevbus = $SIG{BUS} unless $signalLevel; 8812 $signalLevel = shift; 8813 if ($signalLevel) { 8814 $SIG{SEGV} = \&DB::diesignal; 8815 $SIG{BUS} = \&DB::diesignal; 8816 } 8817 else { 8818 $SIG{SEGV} = $prevsegv; 8819 $SIG{BUS} = $prevbus; 8820 } 8821 } ## end if (@_) 8822 $signalLevel; 8823} ## end sub signalLevel 8824 8825=head1 SUBROUTINE DECODING SUPPORT 8826 8827These subroutines are used during the C<x> and C<X> commands to try to 8828produce as much information as possible about a code reference. They use 8829L<Devel::Peek> to try to find the glob in which this code reference lives 8830(if it does) - this allows us to actually code references which correspond 8831to named subroutines (including those aliased via glob assignment). 8832 8833=head2 C<CvGV_name()> 8834 8835Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference 8836via that routine. If this fails, return the reference again (when the 8837reference is stringified, it'll come out as C<SOMETHING(0x...)>). 8838 8839=cut 8840 8841sub CvGV_name { 8842 my $in = shift; 8843 my $name = CvGV_name_or_bust($in); 8844 defined $name ? $name : $in; 8845} 8846 8847=head2 C<CvGV_name_or_bust> I<coderef> 8848 8849Calls L<Devel::Peek> to try to find the glob the ref lives in; returns 8850C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't 8851find a glob for this ref. 8852 8853Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob. 8854 8855=cut 8856 8857use vars qw($skipCvGV); 8858 8859sub CvGV_name_or_bust { 8860 my $in = shift; 8861 return if $skipCvGV; # Backdoor to avoid problems if XS broken... 8862 return unless ref $in; 8863 $in = \&$in; # Hard reference... 8864 eval { _DB__use_full_path(sub { require Devel::Peek; 1; }); } or return; 8865 my $gv = Devel::Peek::CvGV($in) or return; 8866 *$gv{PACKAGE} . '::' . *$gv{NAME}; 8867} ## end sub CvGV_name_or_bust 8868 8869=head2 C<find_sub> 8870 8871A utility routine used in various places; finds the file where a subroutine 8872was defined, and returns that filename and a line-number range. 8873 8874Tries to use C<@sub> first; if it can't find it there, it tries building a 8875reference to the subroutine and uses C<CvGV_name_or_bust> to locate it, 8876loading it into C<@sub> as a side effect (XXX I think). If it can't find it 8877this way, it brute-force searches C<%sub>, checking for identical references. 8878 8879=cut 8880 8881sub _find_sub_helper { 8882 my $subr = shift; 8883 8884 return unless defined &$subr; 8885 my $name = CvGV_name_or_bust($subr); 8886 my $data; 8887 $data = $sub{$name} if defined $name; 8888 return $data if defined $data; 8889 8890 # Old stupid way... 8891 $subr = \&$subr; # Hard reference 8892 my $s; 8893 for ( keys %sub ) { 8894 $s = $_, last if $subr eq \&$_; 8895 } 8896 if ($s) 8897 { 8898 return $sub{$s}; 8899 } 8900 else 8901 { 8902 return; 8903 } 8904 8905} 8906 8907sub find_sub { 8908 my $subr = shift; 8909 return ( $sub{$subr} || _find_sub_helper($subr) ); 8910} ## end sub find_sub 8911 8912=head2 C<methods> 8913 8914A subroutine that uses the utility function C<methods_via> to find all the 8915methods in the class corresponding to the current reference and in 8916C<UNIVERSAL>. 8917 8918=cut 8919 8920use vars qw(%seen); 8921 8922sub methods { 8923 8924 # Figure out the class - either this is the class or it's a reference 8925 # to something blessed into that class. 8926 my $class = shift; 8927 $class = ref $class if ref $class; 8928 8929 local %seen; 8930 8931 # Show the methods that this class has. 8932 methods_via( $class, '', 1 ); 8933 8934 # Show the methods that UNIVERSAL has. 8935 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 ); 8936} ## end sub methods 8937 8938=head2 C<methods_via($class, $prefix, $crawl_upward)> 8939 8940C<methods_via> does the work of crawling up the C<@ISA> tree and reporting 8941all the parent class methods. C<$class> is the name of the next class to 8942try; C<$prefix> is the message prefix, which gets built up as we go up the 8943C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go 8944higher in the C<@ISA> tree, 0 if we should stop. 8945 8946=cut 8947 8948sub methods_via { 8949 8950 # If we've processed this class already, just quit. 8951 my $class = shift; 8952 return if $seen{$class}++; 8953 8954 # This is a package that is contributing the methods we're about to print. 8955 my $prefix = shift; 8956 my $prepend = $prefix ? "via $prefix: " : ''; 8957 my @to_print; 8958 8959 # Extract from all the symbols in this class. 8960 my $class_ref = do { no strict "refs"; \%{$class . '::'} }; 8961 while (my ($name, $glob) = each %$class_ref) { 8962 # references directly in the symbol table are Proxy Constant 8963 # Subroutines, and are by their very nature defined 8964 # Otherwise, check if the thing is a typeglob, and if it is, it decays 8965 # to a subroutine reference, which can be tested by defined. 8966 # $glob might also be the value -1 (from sub foo;) 8967 # or (say) '$$' (from sub foo ($$);) 8968 # \$glob will be SCALAR in both cases. 8969 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob)) 8970 && !$seen{$name}++) { 8971 push @to_print, "$prepend$name\n"; 8972 } 8973 } 8974 8975 { 8976 local $\ = ''; 8977 local $, = ''; 8978 print $DB::OUT $_ foreach sort @to_print; 8979 } 8980 8981 # If the $crawl_upward argument is false, just quit here. 8982 return unless shift; 8983 8984 # $crawl_upward true: keep going up the tree. 8985 # Find all the classes this one is a subclass of. 8986 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} }; 8987 for my $name ( @$class_ISA_ref ) { 8988 8989 # Set up the new prefix. 8990 $prepend = $prefix ? $prefix . " -> $name" : $name; 8991 8992 # Crawl up the tree and keep trying to crawl up. 8993 methods_via( $name, $prepend, 1 ); 8994 } 8995} ## end sub methods_via 8996 8997=head2 C<setman> - figure out which command to use to show documentation 8998 8999Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly. 9000 9001=cut 9002 9003sub setman { 9004 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|amigaos|riscos)\z/s 9005 ? "man" # O Happy Day! 9006 : "perldoc"; # Alas, poor unfortunates 9007} ## end sub setman 9008 9009=head2 C<runman> - run the appropriate command to show documentation 9010 9011Accepts a man page name; runs the appropriate command to display it (set up 9012during debugger initialization). Uses C<_db_system()> to avoid mucking up the 9013program's STDIN and STDOUT. 9014 9015=cut 9016 9017sub runman { 9018 my $page = shift; 9019 unless ($page) { 9020 _db_system("$doccmd $doccmd"); 9021 return; 9022 } 9023 9024 # this way user can override, like with $doccmd="man -Mwhatever" 9025 # or even just "man " to disable the path check. 9026 if ( $doccmd ne 'man' ) { 9027 _db_system("$doccmd $page"); 9028 return; 9029 } 9030 9031 $page = 'perl' if lc($page) eq 'help'; 9032 9033 require Config; 9034 my $man1dir = $Config::Config{man1direxp}; 9035 my $man3dir = $Config::Config{man3direxp}; 9036 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ } 9037 my $manpath = ''; 9038 $manpath .= "$man1dir:" if $man1dir =~ /\S/; 9039 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir; 9040 chop $manpath if $manpath; 9041 9042 # harmless if missing, I figure 9043 local $ENV{MANPATH} = $manpath if $manpath; 9044 my $nopathopt = $^O =~ /dunno what goes here/; 9045 if ( 9046 CORE::system( 9047 $doccmd, 9048 9049 # I just *know* there are men without -M 9050 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), 9051 split ' ', $page 9052 ) 9053 ) 9054 { 9055 unless ( $page =~ /^perl\w/ ) { 9056 # Previously the debugger contained a list which it slurped in, 9057 # listing the known "perl" manpages. However, it was out of date, 9058 # with errors both of omission and inclusion. This approach is 9059 # considerably less complex. The failure mode on a butchered 9060 # install is simply that the user has to run man or perldoc 9061 # "manually" with the full manpage name. 9062 9063 # There is a list of $^O values in installperl to determine whether 9064 # the directory is 'pods' or 'pod'. However, we can avoid tight 9065 # coupling to that by simply checking the "non-standard" 'pods' 9066 # first. 9067 my $pods = "$Config::Config{privlibexp}/pods"; 9068 $pods = "$Config::Config{privlibexp}/pod" 9069 unless -d $pods; 9070 if (-f "$pods/perl$page.pod") { 9071 CORE::system( $doccmd, 9072 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), 9073 "perl$page" ); 9074 } 9075 } 9076 } ## end if (CORE::system($doccmd... 9077} ## end sub runman 9078 9079#use Carp; # This did break, left for debugging 9080 9081=head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK 9082 9083Because of the way the debugger interface to the Perl core is designed, any 9084debugger package globals that C<DB::sub()> requires have to be defined before 9085any subroutines can be called. These are defined in the second C<BEGIN> block. 9086 9087This block sets things up so that (basically) the world is sane 9088before the debugger starts executing. We set up various variables that the 9089debugger has to have set up before the Perl core starts running: 9090 9091=over 4 9092 9093=item * 9094 9095The debugger's own filehandles (copies of STD and STDOUT for now). 9096 9097=item * 9098 9099Characters for shell escapes, the recall command, and the history command. 9100 9101=item * 9102 9103The maximum recursion depth. 9104 9105=item * 9106 9107The size of a C<w> command's window. 9108 9109=item * 9110 9111The before-this-line context to be printed in a C<v> (view a window around this line) command. 9112 9113=item * 9114 9115The fact that we're not in a sub at all right now. 9116 9117=item * 9118 9119The default SIGINT handler for the debugger. 9120 9121=item * 9122 9123The appropriate value of the flag in C<$^D> that says the debugger is running 9124 9125=item * 9126 9127The current debugger recursion level 9128 9129=item * 9130 9131The list of postponed items and the C<$single> stack (XXX define this) 9132 9133=item * 9134 9135That we want no return values and no subroutine entry/exit trace. 9136 9137=back 9138 9139=cut 9140 9141# The following BEGIN is very handy if debugger goes havoc, debugging debugger? 9142 9143use vars qw($db_stop); 9144 9145BEGIN { # This does not compile, alas. (XXX eh?) 9146 $IN = \*STDIN; # For bugs before DB::OUT has been opened 9147 $OUT = \*STDERR; # For errors before DB::OUT has been opened 9148 9149 # Define characters used by command parsing. 9150 $sh = '!'; # Shell escape (does not work) 9151 $rc = ','; # Recall command (does not work) 9152 @hist = ('?'); # Show history (does not work) 9153 @truehist = (); # Can be saved for replay (per session) 9154 9155 # This defines the point at which you get the 'deep recursion' 9156 # warning. It MUST be defined or the debugger will not load. 9157 $deep = 1000; 9158 9159 # Number of lines around the current one that are shown in the 9160 # 'w' command. 9161 $window = 10; 9162 9163 # How much before-the-current-line context the 'v' command should 9164 # use in calculating the start of the window it will display. 9165 $preview = 3; 9166 9167 # We're not in any sub yet, but we need this to be a defined value. 9168 $sub = ''; 9169 9170 # Set up the debugger's interrupt handler. It simply sets a flag 9171 # ($signal) that DB::DB() will check before each command is executed. 9172 $SIG{INT} = \&DB::catch; 9173 9174 # The following lines supposedly, if uncommented, allow the debugger to 9175 # debug itself. Perhaps we can try that someday. 9176 # This may be enabled to debug debugger: 9177 #$warnLevel = 1 unless defined $warnLevel; 9178 #$dieLevel = 1 unless defined $dieLevel; 9179 #$signalLevel = 1 unless defined $signalLevel; 9180 9181 # This is the flag that says "a debugger is running, please call 9182 # DB::DB and DB::sub". We will turn it on forcibly before we try to 9183 # execute anything in the user's context, because we always want to 9184 # get control back. 9185 $db_stop = 0; # Compiler warning ... 9186 $db_stop = 1 << 30; # ... because this is only used in an eval() later. 9187 9188 # This variable records how many levels we're nested in debugging. 9189 # Used in the debugger prompt, and in determining whether it's all over or 9190 # not. 9191 $level = 0; # Level of recursive debugging 9192 9193 # "Triggers bug (?) in perl if we postpone this until runtime." 9194 # XXX No details on this yet, or whether we should fix the bug instead 9195 # of work around it. Stay tuned. 9196 @stack = (0); 9197 9198 # Used to track the current stack depth using the auto-stacked-variable 9199 # trick. 9200 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack 9201 9202 # Don't print return values on exiting a subroutine. 9203 $doret = -2; 9204 9205 # No extry/exit tracing. 9206 $frame = 0; 9207 9208} ## end BEGIN 9209 9210BEGIN { $^W = $ini_warn; } # Switch warnings back 9211 9212=head1 READLINE SUPPORT - COMPLETION FUNCTION 9213 9214=head2 db_complete 9215 9216C<readline> support - adds command completion to basic C<readline>. 9217 9218Returns a list of possible completions to C<readline> when invoked. C<readline> 9219will print the longest common substring following the text already entered. 9220 9221If there is only a single possible completion, C<readline> will use it in full. 9222 9223This code uses C<map> and C<grep> heavily to create lists of possible 9224completion. Think LISP in this section. 9225 9226=cut 9227 9228sub db_complete { 9229 9230 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah 9231 # $text is the text to be completed. 9232 # $line is the incoming line typed by the user. 9233 # $start is the start of the text to be completed in the incoming line. 9234 my ( $text, $line, $start ) = @_; 9235 9236 # Save the initial text. 9237 # The search pattern is current package, ::, extract the next qualifier 9238 # Prefix and pack are set to undef. 9239 my ( $itext, $search, $prefix, $pack ) = 9240 ( $text, "^\Q${package}::\E([^:]+)\$" ); 9241 9242=head3 C<b postpone|compile> 9243 9244=over 4 9245 9246=item * 9247 9248Find all the subroutines that might match in this package 9249 9250=item * 9251 9252Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself) 9253 9254=item * 9255 9256Include all the rest of the subs that are known 9257 9258=item * 9259 9260C<grep> out the ones that match the text we have so far 9261 9262=item * 9263 9264Return this as the list of possible completions 9265 9266=back 9267 9268=cut 9269 9270 return sort grep /^\Q$text/, ( keys %sub ), 9271 qw(postpone load compile), # subroutines 9272 ( map { /$search/ ? ($1) : () } keys %sub ) 9273 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/; 9274 9275=head3 C<b load> 9276 9277Get all the possible files from C<@INC> as it currently stands and 9278select the ones that match the text so far. 9279 9280=cut 9281 9282 return sort grep /^\Q$text/, values %INC # files 9283 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/; 9284 9285=head3 C<V> (list variable) and C<m> (list modules) 9286 9287There are two entry points for these commands: 9288 9289=head4 Unqualified package names 9290 9291Get the top-level packages and grab everything that matches the text 9292so far. For each match, recursively complete the partial packages to 9293get all possible matching packages. Return this sorted list. 9294 9295=cut 9296 9297 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } 9298 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages 9299 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/; 9300 9301=head4 Qualified package names 9302 9303Take a partially-qualified package and find all subpackages for it 9304by getting all the subpackages for the package so far, matching all 9305the subpackages against the text, and discarding all of them which 9306start with 'main::'. Return this list. 9307 9308=cut 9309 9310 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } 9311 grep !/^main::/, grep /^\Q$text/, 9312 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } 9313 do { no strict 'refs'; keys %{ $prefix . '::' } } 9314 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ 9315 and $text =~ /^(.*[^:])::?(\w*)$/ 9316 and $prefix = $1; 9317 9318=head3 C<f> - switch files 9319 9320Here, we want to get a fully-qualified filename for the C<f> command. 9321Possibilities are: 9322 9323=over 4 9324 9325=item 1. The original source file itself 9326 9327=item 2. A file from C<@INC> 9328 9329=item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>). 9330 9331=back 9332 9333=cut 9334 9335 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files 9336 # We might possibly want to switch to an eval (which has a "filename" 9337 # like '(eval 9)'), so we may need to clean up the completion text 9338 # before proceeding. 9339 $prefix = length($1) - length($text); 9340 $text = $1; 9341 9342=pod 9343 9344Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file> 9345(C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these 9346out of C<%main::>, add the initial source file, and extract the ones that 9347match the completion text so far. 9348 9349=cut 9350 9351 return sort 9352 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ), 9353 $0; 9354 } ## end if ($line =~ /^\|*f\s+(.*)/) 9355 9356=head3 Subroutine name completion 9357 9358We look through all of the defined subs (the keys of C<%sub>) and 9359return both all the possible matches to the subroutine name plus 9360all the matches qualified to the current package. 9361 9362=cut 9363 9364 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines 9365 $text = substr $text, 1; 9366 $prefix = "&"; 9367 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ), 9368 ( 9369 map { /$search/ ? ($1) : () } 9370 keys %sub 9371 ); 9372 } ## end if ((substr $text, 0, ... 9373 9374=head3 Scalar, array, and hash completion: partially qualified package 9375 9376Much like the above, except we have to do a little more cleanup: 9377 9378=cut 9379 9380 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package 9381 9382=pod 9383 9384=over 4 9385 9386=item * 9387 9388Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified. 9389 9390=cut 9391 9392 $pack = ( $1 eq 'main' ? '' : $1 ) . '::'; 9393 9394=pod 9395 9396=item * 9397 9398Figure out the prefix vs. what needs completing. 9399 9400=cut 9401 9402 $prefix = ( substr $text, 0, 1 ) . $1 . '::'; 9403 $text = $2; 9404 9405=pod 9406 9407=item * 9408 9409Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities. 9410 9411=cut 9412 9413 my @out = do { 9414 no strict 'refs'; 9415 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/, 9416 keys %$pack; 9417 }; 9418 9419=pod 9420 9421=item * 9422 9423If there's only one hit, and it's a package qualifier, and it's not equal to the initial text, re-complete it using the symbol we actually found. 9424 9425=cut 9426 9427 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { 9428 return db_complete( $out[0], $line, $start ); 9429 } 9430 9431 # Return the list of possibles. 9432 return sort @out; 9433 9434 } ## end if ($text =~ /^[\$@%](.*)::(.*)/) 9435 9436=pod 9437 9438=back 9439 9440=head3 Symbol completion: current package or package C<main>. 9441 9442=cut 9443 9444 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main) 9445=pod 9446 9447=over 4 9448 9449=item * 9450 9451If it's C<main>, delete main to just get C<::> leading. 9452 9453=cut 9454 9455 $pack = ( $package eq 'main' ? '' : $package ) . '::'; 9456 9457=pod 9458 9459=item * 9460 9461We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed. 9462 9463=cut 9464 9465 $prefix = substr $text, 0, 1; 9466 $text = substr $text, 1; 9467 9468 my @out; 9469 9470=pod 9471 9472=item * 9473 9474We look for the lexical scope above DB::DB and auto-complete lexical variables 9475if PadWalker could be loaded. 9476 9477=cut 9478 9479 if (not $text =~ /::/ and eval { 9480 local @INC = @INC; 9481 pop @INC if $INC[-1] eq '.'; 9482 require PadWalker } ) { 9483 my $level = 1; 9484 while (1) { 9485 my @info = caller($level); 9486 $level++; 9487 $level = -1, last 9488 if not @info; 9489 last if $info[3] eq 'DB::DB'; 9490 } 9491 if ($level > 0) { 9492 my $lexicals = PadWalker::peek_my($level); 9493 push @out, grep /^\Q$prefix$text/, keys %$lexicals; 9494 } 9495 } 9496 9497=pod 9498 9499=item * 9500 9501If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols. 9502 9503=cut 9504 9505 push @out, map "$prefix$_", grep /^\Q$text/, 9506 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ), 9507 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) ); 9508 9509=item * 9510 9511If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol. 9512 9513=back 9514 9515=cut 9516 9517 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { 9518 return db_complete( $out[0], $line, $start ); 9519 } 9520 9521 # Return the list of possibles. 9522 return sort @out; 9523 } ## end if ($text =~ /^[\$@%]/) 9524 9525=head3 Options 9526 9527We use C<option_val()> to look up the current value of the option. If there's 9528only a single value, we complete the command in such a way that it is a 9529complete command for setting the option in question. If there are multiple 9530possible values, we generate a command consisting of the option plus a trailing 9531question mark, which, if executed, will list the current value of the option. 9532 9533=cut 9534 9535 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ ) 9536 { # Options after space 9537 # We look for the text to be matched in the list of possible options, 9538 # and fetch the current value. 9539 my @out = grep /^\Q$text/, @options; 9540 my $val = option_val( $out[0], undef ); 9541 9542 # Set up a 'query option's value' command. 9543 my $out = '? '; 9544 if ( not defined $val or $val =~ /[\n\r]/ ) { 9545 9546 # There's really nothing else we can do. 9547 } 9548 9549 # We have a value. Create a proper option-setting command. 9550 elsif ( $val =~ /\s/ ) { 9551 9552 # XXX This may be an extraneous variable. 9553 my $found; 9554 9555 # We'll want to quote the string (because of the embedded 9556 # whtespace), but we want to make sure we don't end up with 9557 # mismatched quote characters. We try several possibilities. 9558 foreach my $l ( split //, qq/\"\'\#\|/ ) { 9559 9560 # If we didn't find this quote character in the value, 9561 # quote it using this quote character. 9562 $out = "$l$val$l ", last if ( index $val, $l ) == -1; 9563 } 9564 } ## end elsif ($val =~ /\s/) 9565 9566 # Don't need any quotes. 9567 else { 9568 $out = "=$val "; 9569 } 9570 9571 # If there were multiple possible values, return '? ', which 9572 # makes the command into a query command. If there was just one, 9573 # have readline append that. 9574 $rl_attribs->{completer_terminator_character} = 9575 ( @out == 1 ? $out : '? ' ); 9576 9577 # Return list of possibilities. 9578 return sort @out; 9579 } ## end if ((substr $line, 0, ... 9580 9581=head3 Filename completion 9582 9583For entering filenames. We simply call C<readline>'s C<filename_list()> 9584method with the completion text to get the possible completions. 9585 9586=cut 9587 9588 return $term->filename_list($text); # filenames 9589 9590} ## end sub db_complete 9591 9592=head1 MISCELLANEOUS SUPPORT FUNCTIONS 9593 9594Functions that possibly ought to be somewhere else. 9595 9596=head2 end_report 9597 9598Say we're done. 9599 9600=cut 9601 9602sub end_report { 9603 local $\ = ''; 9604 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n"; 9605} 9606 9607=head2 clean_ENV 9608 9609If we have $ini_pids, save it in the environment; else remove it from the 9610environment. Used by the C<R> (restart) command. 9611 9612=cut 9613 9614sub clean_ENV { 9615 if ( defined($ini_pids) ) { 9616 $ENV{PERLDB_PIDS} = $ini_pids; 9617 } 9618 else { 9619 delete( $ENV{PERLDB_PIDS} ); 9620 } 9621} ## end sub clean_ENV 9622 9623# PERLDBf_... flag names from perl.h 9624our ( %DollarCaretP_flags, %DollarCaretP_flags_r ); 9625 9626BEGIN { 9627 %DollarCaretP_flags = ( 9628 PERLDBf_SUB => 0x01, # Debug sub enter/exit 9629 PERLDBf_LINE => 0x02, # Keep line # 9630 PERLDBf_NOOPT => 0x04, # Switch off optimizations 9631 PERLDBf_INTER => 0x08, # Preserve more data 9632 PERLDBf_SUBLINE => 0x10, # Keep subr source lines 9633 PERLDBf_SINGLE => 0x20, # Start with single-step on 9634 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr 9635 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto 9636 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals 9637 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs 9638 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"} 9639 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO 9640 ); 9641 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger 9642 # doesn't need to set it. It's provided for the benefit of profilers and 9643 # other code analysers. 9644 9645 %DollarCaretP_flags_r = reverse %DollarCaretP_flags; 9646} 9647 9648sub parse_DollarCaretP_flags { 9649 my $flags = shift; 9650 $flags =~ s/^\s+//; 9651 $flags =~ s/\s+$//; 9652 my $acu = 0; 9653 foreach my $f ( split /\s*\|\s*/, $flags ) { 9654 my $value; 9655 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) { 9656 $value = hex $1; 9657 } 9658 elsif ( $f =~ /^(\d+)$/ ) { 9659 $value = int $1; 9660 } 9661 elsif ( $f =~ /^DEFAULT$/i ) { 9662 $value = $DollarCaretP_flags{PERLDB_ALL}; 9663 } 9664 else { 9665 $f =~ /^(?:PERLDBf_)?(.*)$/i; 9666 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) }; 9667 unless ( defined $value ) { 9668 print $OUT ( 9669 "Unrecognized \$^P flag '$f'!\n", 9670 "Acceptable flags are: " 9671 . join( ', ', sort keys %DollarCaretP_flags ), 9672 ", and hexadecimal and decimal numbers.\n" 9673 ); 9674 return undef; 9675 } 9676 } 9677 $acu |= $value; 9678 } 9679 $acu; 9680} 9681 9682sub expand_DollarCaretP_flags { 9683 my $DollarCaretP = shift; 9684 my @bits = ( 9685 map { 9686 my $n = ( 1 << $_ ); 9687 ( $DollarCaretP & $n ) 9688 ? ( $DollarCaretP_flags_r{$n} 9689 || sprintf( '0x%x', $n ) ) 9690 : () 9691 } 0 .. 31 9692 ); 9693 return @bits ? join( '|', @bits ) : 0; 9694} 9695 9696=over 4 9697 9698=item rerun 9699 9700Rerun the current session to: 9701 9702 rerun current position 9703 9704 rerun 4 command number 4 9705 9706 rerun -4 current command minus 4 (go back 4 steps) 9707 9708Whether this always makes sense, in the current context is unknowable, and is 9709in part left as a useful exercise for the reader. This sub returns the 9710appropriate arguments to rerun the current session. 9711 9712=cut 9713 9714sub rerun { 9715 my $i = shift; 9716 my @args; 9717 pop(@truehist); # strim 9718 unless (defined $truehist[$i]) { 9719 print "Unable to return to non-existent command: $i\n"; 9720 } else { 9721 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist); 9722 my @temp = @truehist; # store 9723 push(@DB::typeahead, @truehist); # saved 9724 @truehist = @hist = (); # flush 9725 @args = restart(); # setup 9726 get_list("PERLDB_HIST"); # clean 9727 set_list("PERLDB_HIST", @temp); # reset 9728 } 9729 return @args; 9730} 9731 9732=item restart 9733 9734Restarting the debugger is a complex operation that occurs in several phases. 9735First, we try to reconstruct the command line that was used to invoke Perl 9736and the debugger. 9737 9738=cut 9739 9740sub restart { 9741 # I may not be able to resurrect you, but here goes ... 9742 print $OUT 9743"Warning: some settings and command-line options may be lost!\n"; 9744 my ( @script, @flags, $cl ); 9745 9746 # If warn was on before, turn it on again. 9747 push @flags, '-w' if $ini_warn; 9748 9749 # Rebuild the -I flags that were on the initial 9750 # command line. 9751 for (@ini_INC) { 9752 push @flags, '-I', $_; 9753 } 9754 9755 # Turn on taint if it was on before. 9756 push @flags, '-T' if ${^TAINT}; 9757 9758 # Arrange for setting the old INC: 9759 # Save the current @init_INC in the environment. 9760 set_list( "PERLDB_INC", @ini_INC ); 9761 9762 # If this was a perl one-liner, go to the "file" 9763 # corresponding to the one-liner read all the lines 9764 # out of it (except for the first one, which is going 9765 # to be added back on again when 'perl -d' runs: that's 9766 # the 'require perl5db.pl;' line), and add them back on 9767 # to the command line to be executed. 9768 if ( $0 eq '-e' ) { 9769 my $lines = *{$main::{'_<-e'}}{ARRAY}; 9770 for ( 1 .. $#$lines ) { # The first line is PERL5DB 9771 chomp( $cl = $lines->[$_] ); 9772 push @script, '-e', $cl; 9773 } 9774 } ## end if ($0 eq '-e') 9775 9776 # Otherwise we just reuse the original name we had 9777 # before. 9778 else { 9779 @script = $0; 9780 } 9781 9782=pod 9783 9784After the command line has been reconstructed, the next step is to save 9785the debugger's status in environment variables. The C<DB::set_list> routine 9786is used to save aggregate variables (both hashes and arrays); scalars are 9787just popped into environment variables directly. 9788 9789=cut 9790 9791 # If the terminal supported history, grab it and 9792 # save that in the environment. 9793 set_list( "PERLDB_HIST", 9794 $term->Features->{getHistory} 9795 ? $term->GetHistory 9796 : @hist ); 9797 9798 # Find all the files that were visited during this 9799 # session (i.e., the debugger had magic hashes 9800 # corresponding to them) and stick them in the environment. 9801 my @had_breakpoints = keys %had_breakpoints; 9802 set_list( "PERLDB_VISITED", @had_breakpoints ); 9803 9804 # Save the debugger options we chose. 9805 set_list( "PERLDB_OPT", %option ); 9806 # set_list( "PERLDB_OPT", options2remember() ); 9807 9808 # Save the break-on-loads. 9809 set_list( "PERLDB_ON_LOAD", %break_on_load ); 9810 9811=pod 9812 9813The most complex part of this is the saving of all of the breakpoints. They 9814can live in an awful lot of places, and we have to go through all of them, 9815find the breakpoints, and then save them in the appropriate environment 9816variable via C<DB::set_list>. 9817 9818=cut 9819 9820 # Go through all the breakpoints and make sure they're 9821 # still valid. 9822 my @hard; 9823 for ( 0 .. $#had_breakpoints ) { 9824 9825 # We were in this file. 9826 my $file = $had_breakpoints[$_]; 9827 9828 # Grab that file's magic line hash. 9829 *dbline = $main::{ '_<' . $file }; 9830 9831 # Skip out if it doesn't exist, or if the breakpoint 9832 # is in a postponed file (we'll do postponed ones 9833 # later). 9834 next unless %dbline or $postponed_file{$file}; 9835 9836 # In an eval. This is a little harder, so we'll 9837 # do more processing on that below. 9838 ( push @hard, $file ), next 9839 if $file =~ /^\(\w*eval/; 9840 9841 # XXX I have no idea what this is doing. Yet. 9842 my @add; 9843 @add = %{ $postponed_file{$file} } 9844 if $postponed_file{$file}; 9845 9846 # Save the list of all the breakpoints for this file. 9847 set_list( "PERLDB_FILE_$_", %dbline, @add ); 9848 9849 # Serialize the extra data %breakpoints_data hash. 9850 # That's a bug fix. 9851 set_list( "PERLDB_FILE_ENABLED_$_", 9852 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 } 9853 sort { $a <=> $b } keys(%dbline) 9854 ) 9855 } ## end for (0 .. $#had_breakpoints) 9856 9857 # The breakpoint was inside an eval. This is a little 9858 # more difficult. XXX and I don't understand it. 9859 foreach my $hard_file (@hard) { 9860 # Get over to the eval in question. 9861 *dbline = $main::{ '_<' . $hard_file }; 9862 my $quoted = quotemeta $hard_file; 9863 my %subs; 9864 for my $sub ( keys %sub ) { 9865 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) { 9866 $subs{$sub} = [ $n1, $n2 ]; 9867 } 9868 } 9869 unless (%subs) { 9870 print {$OUT} 9871 "No subroutines in $hard_file, ignoring breakpoints.\n"; 9872 next; 9873 } 9874 LINES: foreach my $line ( keys %dbline ) { 9875 9876 # One breakpoint per sub only: 9877 my ( $offset, $found ); 9878 SUBS: foreach my $sub ( keys %subs ) { 9879 if ( 9880 $subs{$sub}->[1] >= $line # Not after the subroutine 9881 and ( 9882 not defined $offset # Not caught 9883 or $offset < 0 9884 ) 9885 ) 9886 { # or badly caught 9887 $found = $sub; 9888 $offset = $line - $subs{$sub}->[0]; 9889 if ($offset >= 0) { 9890 $offset = "+$offset"; 9891 last SUBS; 9892 } 9893 } ## end if ($subs{$sub}->[1] >=... 9894 } ## end for $sub (keys %subs) 9895 if ( defined $offset ) { 9896 $postponed{$found} = 9897 "break $offset if $dbline{$line}"; 9898 } 9899 else { 9900 print {$OUT} 9901 ("Breakpoint in ${hard_file}:$line ignored:" 9902 . " after all the subroutines.\n"); 9903 } 9904 } ## end for $line (keys %dbline) 9905 } ## end for (@hard) 9906 9907 # Save the other things that don't need to be 9908 # processed. 9909 set_list( "PERLDB_POSTPONE", %postponed ); 9910 set_list( "PERLDB_PRETYPE", @$pretype ); 9911 set_list( "PERLDB_PRE", @$pre ); 9912 set_list( "PERLDB_POST", @$post ); 9913 set_list( "PERLDB_TYPEAHEAD", @typeahead ); 9914 9915 # We are officially restarting. 9916 $ENV{PERLDB_RESTART} = 1; 9917 9918 # We are junking all child debuggers. 9919 delete $ENV{PERLDB_PIDS}; # Restore ini state 9920 9921 # Set this back to the initial pid. 9922 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids; 9923 9924=pod 9925 9926After all the debugger status has been saved, we take the command we built up 9927and then return it, so we can C<exec()> it. The debugger will spot the 9928C<PERLDB_RESTART> environment variable and realize it needs to reload its state 9929from the environment. 9930 9931=cut 9932 9933 # And run Perl again. Add the "-d" flag, all the 9934 # flags we built up, the script (whether a one-liner 9935 # or a file), add on the -emacs flag for a client editor, 9936 # and then the old arguments. 9937 9938 return ($^X, '-d', @flags, @script, ($client_editor ? '-emacs' : ()), @ARGS); 9939 9940}; # end restart 9941 9942=back 9943 9944=head1 END PROCESSING - THE C<END> BLOCK 9945 9946Come here at the very end of processing. We want to go into a 9947loop where we allow the user to enter commands and interact with the 9948debugger, but we don't want anything else to execute. 9949 9950First we set the C<$finished> variable, so that some commands that 9951shouldn't be run after the end of program quit working. 9952 9953We then figure out whether we're truly done (as in the user entered a C<q> 9954command, or we finished execution while running nonstop). If we aren't, 9955we set C<$single> to 1 (causing the debugger to get control again). 9956 9957We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...> 9958message and returns control to the debugger. Repeat. 9959 9960When the user finally enters a C<q> command, C<$fall_off_end> is set to 99611 and the C<END> block simply exits with C<$single> set to 0 (don't 9962break, run to completion.). 9963 9964=cut 9965 9966END { 9967 $finished = 1 if $inhibit_exit; # So that some commands may be disabled. 9968 $fall_off_end = 1 unless $inhibit_exit; 9969 9970 # Do not stop in at_exit() and destructors on exit: 9971 if ($fall_off_end or $runnonstop) { 9972 save_hist(); 9973 } else { 9974 $DB::single = 1; 9975 DB::fake::at_exit(); 9976 } 9977} ## end END 9978 9979=head1 PRE-5.8 COMMANDS 9980 9981Some of the commands changed function quite a bit in the 5.8 command 9982realignment, so much so that the old code had to be replaced completely. 9983Because we wanted to retain the option of being able to go back to the 9984former command set, we moved the old code off to this section. 9985 9986There's an awful lot of duplicated code here. We've duplicated the 9987comments to keep things clear. 9988 9989=head2 Null command 9990 9991Does nothing. Used to I<turn off> commands. 9992 9993=cut 9994 9995sub cmd_pre580_null { 9996 9997 # do nothing... 9998} 9999 10000=head2 Old C<a> command. 10001 10002This version added actions if you supplied them, and deleted them 10003if you didn't. 10004 10005=cut 10006 10007sub cmd_pre580_a { 10008 my $xcmd = shift; 10009 my $cmd = shift; 10010 10011 # Argument supplied. Add the action. 10012 if ( $cmd =~ /^(\d*)\s*(.*)/ ) { 10013 10014 # If the line isn't there, use the current line. 10015 my $i = $1 || $line; 10016 my $j = $2; 10017 10018 # If there is an action ... 10019 if ( length $j ) { 10020 10021 # ... but the line isn't breakable, skip it. 10022 if ( $dbline[$i] == 0 ) { 10023 print $OUT "Line $i may not have an action.\n"; 10024 } 10025 else { 10026 10027 # ... and the line is breakable: 10028 # Mark that there's an action in this file. 10029 $had_breakpoints{$filename} |= 2; 10030 10031 # Delete any current action. 10032 $dbline{$i} =~ s/\0[^\0]*//; 10033 10034 # Add the new action, continuing the line as needed. 10035 $dbline{$i} .= "\0" . action($j); 10036 } 10037 } ## end if (length $j) 10038 10039 # No action supplied. 10040 else { 10041 10042 # Delete the action. 10043 $dbline{$i} =~ s/\0[^\0]*//; 10044 10045 # Mark as having no break or action if nothing's left. 10046 delete $dbline{$i} if $dbline{$i} eq ''; 10047 } 10048 } ## end if ($cmd =~ /^(\d*)\s*(.*)/) 10049} ## end sub cmd_pre580_a 10050 10051=head2 Old C<b> command 10052 10053Add breakpoints. 10054 10055=cut 10056 10057sub cmd_pre580_b { 10058 my $xcmd = shift; 10059 my $cmd = shift; 10060 my $dbline = shift; 10061 10062 # Break on load. 10063 if ( $cmd =~ /^load\b\s*(.*)/ ) { 10064 my $file = $1; 10065 $file =~ s/\s+$//; 10066 cmd_b_load($file); 10067 } 10068 10069 # b compile|postpone <some sub> [<condition>] 10070 # The interpreter actually traps this one for us; we just put the 10071 # necessary condition in the %postponed hash. 10072 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { 10073 10074 # Capture the condition if there is one. Make it true if none. 10075 my $cond = length $3 ? $3 : '1'; 10076 10077 # Save the sub name and set $break to 1 if $1 was 'postpone', 0 10078 # if it was 'compile'. 10079 my ( $subname, $break ) = ( $2, $1 eq 'postpone' ); 10080 10081 # De-Perl4-ify the name - ' separators to ::. 10082 $subname =~ s/\'/::/g; 10083 10084 # Qualify it into the current package unless it's already qualified. 10085 $subname = "${package}::" . $subname 10086 unless $subname =~ /::/; 10087 10088 # Add main if it starts with ::. 10089 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 10090 10091 # Save the break type for this sub. 10092 $postponed{$subname} = $break ? "break +0 if $cond" : "compile"; 10093 } ## end elsif ($cmd =~ ... 10094 10095 # b <sub name> [<condition>] 10096 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { 10097 my $subname = $1; 10098 my $cond = length $2 ? $2 : '1'; 10099 cmd_b_sub( $subname, $cond ); 10100 } 10101 # b <line> [<condition>]. 10102 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) { 10103 my $i = $1 || $dbline; 10104 my $cond = length $2 ? $2 : '1'; 10105 cmd_b_line( $i, $cond ); 10106 } 10107} ## end sub cmd_pre580_b 10108 10109=head2 Old C<D> command. 10110 10111Delete all breakpoints unconditionally. 10112 10113=cut 10114 10115sub cmd_pre580_D { 10116 my $xcmd = shift; 10117 my $cmd = shift; 10118 if ( $cmd =~ /^\s*$/ ) { 10119 print $OUT "Deleting all breakpoints...\n"; 10120 10121 # %had_breakpoints lists every file that had at least one 10122 # breakpoint in it. 10123 my $file; 10124 for $file ( keys %had_breakpoints ) { 10125 10126 # Switch to the desired file temporarily. 10127 local *dbline = $main::{ '_<' . $file }; 10128 10129 $max = $#dbline; 10130 my $was; 10131 10132 # For all lines in this file ... 10133 for my $i (1 .. $max) { 10134 10135 # If there's a breakpoint or action on this line ... 10136 if ( defined $dbline{$i} ) { 10137 10138 # ... remove the breakpoint. 10139 $dbline{$i} =~ s/^[^\0]+//; 10140 if ( $dbline{$i} =~ s/^\0?$// ) { 10141 10142 # Remove the entry altogether if no action is there. 10143 delete $dbline{$i}; 10144 } 10145 } ## end if (defined $dbline{$i... 10146 } ## end for my $i (1 .. $max) 10147 10148 # If, after we turn off the "there were breakpoints in this file" 10149 # bit, the entry in %had_breakpoints for this file is zero, 10150 # we should remove this file from the hash. 10151 if ( not $had_breakpoints{$file} &= ~1 ) { 10152 delete $had_breakpoints{$file}; 10153 } 10154 } ## end for $file (keys %had_breakpoints) 10155 10156 # Kill off all the other breakpoints that are waiting for files that 10157 # haven't been loaded yet. 10158 undef %postponed; 10159 undef %postponed_file; 10160 undef %break_on_load; 10161 } ## end if ($cmd =~ /^\s*$/) 10162} ## end sub cmd_pre580_D 10163 10164=head2 Old C<h> command 10165 10166Print help. Defaults to printing the long-form help; the 5.8 version 10167prints the summary by default. 10168 10169=cut 10170 10171sub cmd_pre580_h { 10172 my $xcmd = shift; 10173 my $cmd = shift; 10174 10175 # Print the *right* help, long format. 10176 if ( $cmd =~ /^\s*$/ ) { 10177 print_help($pre580_help); 10178 } 10179 10180 # 'h h' - explicitly-requested summary. 10181 elsif ( $cmd =~ /^h\s*/ ) { 10182 print_help($pre580_summary); 10183 } 10184 10185 # Find and print a command's help. 10186 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) { 10187 my $asked = $1; # for proper errmsg 10188 my $qasked = quotemeta($asked); # for searching 10189 # XXX: finds CR but not <CR> 10190 if ( 10191 $pre580_help =~ /^ 10192 <? # Optional '<' 10193 (?:[IB]<) # Optional markup 10194 $qasked # The command name 10195 /mx 10196 ) 10197 { 10198 10199 while ( 10200 $pre580_help =~ /^ 10201 ( # The command help: 10202 <? # Optional '<' 10203 (?:[IB]<) # Optional markup 10204 $qasked # The command name 10205 ([\s\S]*?) # Lines starting with tabs 10206 \n # Final newline 10207 ) 10208 (?!\s)/mgx 10209 ) # Line not starting with space 10210 # (Next command's help) 10211 { 10212 print_help($1); 10213 } 10214 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m) 10215 10216 # Help not found. 10217 else { 10218 print_help("B<$asked> is not a debugger command.\n"); 10219 } 10220 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/) 10221} ## end sub cmd_pre580_h 10222 10223=head2 Old C<W> command 10224 10225C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all. 10226 10227=cut 10228 10229sub cmd_pre580_W { 10230 my $xcmd = shift; 10231 my $cmd = shift; 10232 10233 # Delete all watch expressions. 10234 if ( $cmd =~ /^$/ ) { 10235 10236 # No watching is going on. 10237 $trace &= ~2; 10238 10239 # Kill all the watch expressions and values. 10240 @to_watch = @old_watch = (); 10241 } 10242 10243 # Add a watch expression. 10244 elsif ( $cmd =~ /^(.*)/s ) { 10245 10246 # add it to the list to be watched. 10247 push @to_watch, $1; 10248 10249 # Get the current value of the expression. 10250 # Doesn't handle expressions returning list values! 10251 $evalarg = $1; 10252 # The &-call is here to ascertain the mutability of @_. 10253 my ($val) = &DB::eval; 10254 $val = ( defined $val ) ? "'$val'" : 'undef'; 10255 10256 # Save it. 10257 push @old_watch, $val; 10258 10259 # We're watching stuff. 10260 $trace |= 2; 10261 10262 } ## end elsif ($cmd =~ /^(.*)/s) 10263} ## end sub cmd_pre580_W 10264 10265=head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS 10266 10267The debugger used to have a bunch of nearly-identical code to handle 10268the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and 10269C<cmd_prepost> unify all this into one set of code to handle the 10270appropriate actions. 10271 10272=head2 C<cmd_pre590_prepost> 10273 10274A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't 10275do something destructive. In pre 5.8 debuggers, the default action was to 10276delete all the actions. 10277 10278=cut 10279 10280sub cmd_pre590_prepost { 10281 my $cmd = shift; 10282 my $line = shift || '*'; 10283 my $dbline = shift; 10284 10285 return cmd_prepost( $cmd, $line, $dbline ); 10286} ## end sub cmd_pre590_prepost 10287 10288=head2 C<cmd_prepost> 10289 10290Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc. 10291Since the lists of actions are all held in arrays that are pointed to by 10292references anyway, all we have to do is pick the right array reference and 10293then use generic code to all, delete, or list actions. 10294 10295=cut 10296 10297sub cmd_prepost { 10298 my $cmd = shift; 10299 10300 # No action supplied defaults to 'list'. 10301 my $line = shift || '?'; 10302 10303 # Figure out what to put in the prompt. 10304 my $which = ''; 10305 10306 # Make sure we have some array or another to address later. 10307 # This means that if for some reason the tests fail, we won't be 10308 # trying to stash actions or delete them from the wrong place. 10309 my $aref = []; 10310 10311 # < - Perl code to run before prompt. 10312 if ( $cmd =~ /^\</o ) { 10313 $which = 'pre-perl'; 10314 $aref = $pre; 10315 } 10316 10317 # > - Perl code to run after prompt. 10318 elsif ( $cmd =~ /^\>/o ) { 10319 $which = 'post-perl'; 10320 $aref = $post; 10321 } 10322 10323 # { - first check for properly-balanced braces. 10324 elsif ( $cmd =~ /^\{/o ) { 10325 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) { 10326 print $OUT 10327"$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n"; 10328 } 10329 10330 # Properly balanced. Pre-prompt debugger actions. 10331 else { 10332 $which = 'pre-debugger'; 10333 $aref = $pretype; 10334 } 10335 } ## end elsif ( $cmd =~ /^\{/o ) 10336 10337 # Did we find something that makes sense? 10338 unless ($which) { 10339 print $OUT "Confused by command: $cmd\n"; 10340 } 10341 10342 # Yes. 10343 else { 10344 10345 # List actions. 10346 if ( $line =~ /^\s*\?\s*$/o ) { 10347 unless (@$aref) { 10348 10349 # Nothing there. Complain. 10350 print $OUT "No $which actions.\n"; 10351 } 10352 else { 10353 10354 # List the actions in the selected list. 10355 print $OUT "$which commands:\n"; 10356 foreach my $action (@$aref) { 10357 print $OUT "\t$cmd -- $action\n"; 10358 } 10359 } ## end else 10360 } ## end if ( $line =~ /^\s*\?\s*$/o) 10361 10362 # Might be a delete. 10363 else { 10364 if ( length($cmd) == 1 ) { 10365 if ( $line =~ /^\s*\*\s*$/o ) { 10366 10367 # It's a delete. Get rid of the old actions in the 10368 # selected list.. 10369 @$aref = (); 10370 print $OUT "All $cmd actions cleared.\n"; 10371 } 10372 else { 10373 10374 # Replace all the actions. (This is a <, >, or {). 10375 @$aref = action($line); 10376 } 10377 } ## end if ( length($cmd) == 1) 10378 elsif ( length($cmd) == 2 ) { 10379 10380 # Add the action to the line. (This is a <<, >>, or {{). 10381 push @$aref, action($line); 10382 } 10383 else { 10384 10385 # <<<, >>>>, {{{{{{ ... something not a command. 10386 print $OUT 10387 "Confused by strange length of $which command($cmd)...\n"; 10388 } 10389 } ## end else [ if ( $line =~ /^\s*\?\s*$/o) 10390 } ## end else 10391} ## end sub cmd_prepost 10392 10393=head1 C<DB::fake> 10394 10395Contains the C<at_exit> routine that the debugger uses to issue the 10396C<Debugged program terminated ...> message after the program completes. See 10397the L<C<END>|/END PROCESSING - THE END BLOCK> block documentation for more 10398details. 10399 10400=cut 10401 10402package DB::fake; 10403 10404sub at_exit { 10405 "Debugged program terminated. Use 'q' to quit or 'R' to restart."; 10406} 10407 10408package DB; # Do not trace this 1; below! 10409 104101; 10411 10412 10413