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 = '1.80'; 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 threads::shared->import('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 = my $subname = shift; 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 + $incr ) ); 2705} 2706 2707sub _cmd_l_calc_initial_end_and_i { 2708 my ($current_line, $start_match, $end_match) = @_; 2709 2710 my $end = $end_match // $start_match // $max; 2711 # Clean up the end spec if needed. 2712 $end = $current_line if $end eq '.'; 2713 _minify_to_max(\$end); 2714 2715 # Determine the loop start point. 2716 my $i = $start_match // 1; 2717 $i = $current_line if $i eq '.'; 2718 2719 return ($end, $i); 2720} 2721 2722sub _cmd_l_range { 2723 my ($current_line, $start_match, $end_match) = @_; 2724 2725 my ($end, $i) = 2726 _cmd_l_calc_initial_end_and_i($current_line, $start_match, $end_match); 2727 2728 # If we're running under a client editor, force it to show the lines. 2729 if ($client_editor) { 2730 print {$OUT} "$sub_twice$filename:$i:0\n"; 2731 $i = $end; 2732 } 2733 # We're doing it ourselves. We want to show the line and special 2734 # markers for: 2735 # - the current line in execution 2736 # - whether a line is breakable or not 2737 # - whether a line has a break or not 2738 # - whether a line has an action or not 2739 else { 2740 I_TO_END: 2741 for ( ; $i <= $end ; $i++ ) { 2742 2743 # Check for breakpoints and actions. 2744 my ( $stop, $action ); 2745 if ($dbline{$i}) { 2746 ( $stop, $action ) = split( /\0/, $dbline{$i} ); 2747 } 2748 2749 # ==> if this is the current line in execution, 2750 # : if it's breakable. 2751 my $arrow = 2752 ( $i == $current_line and $filename eq $filename_ini ) 2753 ? '==>' 2754 : ( $dbline[$i] + 0 ? ':' : ' ' ); 2755 2756 # Add break and action indicators. 2757 $arrow .= 'b' if $stop; 2758 $arrow .= 'a' if $action; 2759 2760 # Print the line. 2761 print {$OUT} "$i$arrow\t", $dbline[$i]; 2762 2763 # Move on to the next line. Drop out on an interrupt. 2764 if ($signal) { 2765 $i++; 2766 last I_TO_END; 2767 } 2768 } ## end for (; $i <= $end ; $i++) 2769 2770 # Line the prompt up; print a newline if the last line listed 2771 # didn't have a newline. 2772 if ($dbline[ $i - 1 ] !~ /\n\z/) { 2773 print {$OUT} "\n"; 2774 } 2775 } ## end else [ if ($client_editor) 2776 2777 # Save the point we last listed to in case another relative 'l' 2778 # command is desired. Don't let it run off the end. 2779 $start = $i; 2780 _minify_to_max(\$start); 2781 2782 return; 2783} 2784 2785sub _cmd_l_main { 2786 my $spec = shift; 2787 2788 # If the line is '$something', assume this is a scalar containing a 2789 # line number. 2790 # Set up for DB::eval() - evaluate in *user* context. 2791 if ( $spec =~ /\A(\$(?:[0-9]+|[^\W\d]\w*))\z/ ) { 2792 return _cmd_l_handle_var_name($spec); 2793 } 2794 # l name. Try to find a sub by that name. 2795 elsif ( ($subname) = $spec =~ /\A([\':A-Za-z_][\':\w]*(?:\[.*\])?)/s ) { 2796 return _cmd_l_handle_subname($subname); 2797 } 2798 # Bare 'l' command. 2799 elsif ( $spec !~ /\S/ ) { 2800 return _cmd_l_empty(); 2801 } 2802 # l [start]+number_of_lines 2803 elsif ( my ($new_start, $new_incr) = $spec =~ /\A(\d*)\+(\d*)\z/ ) { 2804 return _cmd_l_plus($new_start, $new_incr); 2805 } 2806 # l start-stop or l start,stop 2807 # Purposefully limited to ASCII; UTF-8 support would be nice sometime. 2808 elsif (my ($s, $e) = $spec =~ /\A(?:(\.|\d+)(?:[-,](\.|\d+))?)?\z/a ) { 2809 return _cmd_l_range($line, $s, $e); 2810 } 2811 # Protest at bizarre and incorrect specs. 2812 else { 2813 print {$OUT} "Invalid line specification '$spec'.\n"; 2814 } 2815 2816 return; 2817} ## end sub _cmd_l_main 2818 2819sub _DB__handle_l_command { 2820 my $self = shift; 2821 2822 _cmd_l_main($self->cmd_args); 2823 next CMD; 2824} 2825 2826 2827# 't' is type. 2828# 'm' is method. 2829# 'v' is the value (i.e: method name or subroutine ref). 2830# 's' is subroutine. 2831my %cmd_lookup; 2832 2833BEGIN 2834{ 2835 %cmd_lookup = 2836( 2837 '-' => { t => 'm', v => '_handle_dash_command', }, 2838 '.' => { t => 's', v => \&_DB__handle_dot_command, }, 2839 '=' => { t => 'm', v => '_handle_equal_sign_command', }, 2840 'H' => { t => 'm', v => '_handle_H_command', }, 2841 'S' => { t => 'm', v => '_handle_S_command', }, 2842 'T' => { t => 'm', v => '_handle_T_command', }, 2843 'W' => { t => 'm', v => '_handle_W_command', }, 2844 'c' => { t => 's', v => \&_DB__handle_c_command, }, 2845 'f' => { t => 's', v => \&_DB__handle_f_command, }, 2846 'i' => { t => 's', v => \&_DB__handle_i_command, }, 2847 'l' => { t => 's', v => \&_DB__handle_l_command, }, 2848 'm' => { t => 's', v => \&_DB__handle_m_command, }, 2849 'n' => { t => 'm', v => '_handle_n_command', }, 2850 'p' => { t => 'm', v => '_handle_p_command', }, 2851 'q' => { t => 'm', v => '_handle_q_command', }, 2852 'r' => { t => 'm', v => '_handle_r_command', }, 2853 's' => { t => 'm', v => '_handle_s_command', }, 2854 'save' => { t => 'm', v => '_handle_save_command', }, 2855 'source' => { t => 'm', v => '_handle_source_command', }, 2856 't' => { t => 'm', v => '_handle_t_command', }, 2857 'w' => { t => 'm', v => '_handle_w_command', }, 2858 'x' => { t => 'm', v => '_handle_x_command', }, 2859 'y' => { t => 's', v => \&_DB__handle_y_command, }, 2860 (map { $_ => { t => 'm', v => '_handle_V_command_and_X_command', }, } 2861 ('X', 'V')), 2862 (map { $_ => { t => 'm', v => '_handle_enable_disable_commands', }, } 2863 qw(enable disable)), 2864 (map { $_ => 2865 { t => 's', v => \&_DB__handle_restart_and_rerun_commands, }, 2866 } qw(R rerun)), 2867 (map { $_ => {t => 'm', v => '_handle_cmd_wrapper_commands' }, } 2868 qw(a A b B e E h L M o O v w W)), 2869); 2870}; 2871 2872sub DB { 2873 2874 # lock the debugger and get the thread id for the prompt 2875 lock($DBGR); 2876 my $tid; 2877 my $position; 2878 my ($prefix, $after, $infix); 2879 my $pat; 2880 my $explicit_stop; 2881 my $piped; 2882 my $selected; 2883 2884 if ($ENV{PERL5DB_THREADED}) { 2885 $tid = eval { "[".threads->tid."]" }; 2886 } 2887 2888 my $cmd_verb; 2889 my $cmd_args; 2890 2891 my $obj = DB::Obj->new( 2892 { 2893 position => \$position, 2894 prefix => \$prefix, 2895 after => \$after, 2896 explicit_stop => \$explicit_stop, 2897 infix => \$infix, 2898 cmd_args => \$cmd_args, 2899 cmd_verb => \$cmd_verb, 2900 pat => \$pat, 2901 piped => \$piped, 2902 selected => \$selected, 2903 }, 2904 ); 2905 2906 $obj->_DB_on_init__initialize_globals(@_); 2907 2908 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W. 2909 # The code being debugged may have altered them. 2910 DB::save(); 2911 2912 # Since DB::DB gets called after every line, we can use caller() to 2913 # figure out where we last were executing. Sneaky, eh? This works because 2914 # caller is returning all the extra information when called from the 2915 # debugger. 2916 local ( $package, $filename, $line ) = caller; 2917 $filename_ini = $filename; 2918 2919 # set up the context for DB::eval, so it can properly execute 2920 # code on behalf of the user. We add the package in so that the 2921 # code is eval'ed in the proper package (not in the debugger!). 2922 local $usercontext = _calc_usercontext($package); 2923 2924 # Create an alias to the active file magical array to simplify 2925 # the code here. 2926 local (*dbline) = $main::{ '_<' . $filename }; 2927 2928 # Last line in the program. 2929 $max = $#dbline; 2930 2931 # The &-call is here to ascertain the mutability of @_. 2932 &_DB__determine_if_we_should_break; 2933 2934 # Preserve the current stop-or-not, and see if any of the W 2935 # (watch expressions) has changed. 2936 my $was_signal = $signal; 2937 2938 # If we have any watch expressions ... 2939 _DB__handle_watch_expressions($obj); 2940 2941=head2 C<watchfunction()> 2942 2943C<watchfunction()> is a function that can be defined by the user; it is a 2944function which will be run on each entry to C<DB::DB>; it gets the 2945current package, filename, and line as its parameters. 2946 2947The watchfunction can do anything it likes; it is executing in the 2948debugger's context, so it has access to all of the debugger's internal 2949data structures and functions. 2950 2951C<watchfunction()> can control the debugger's actions. Any of the following 2952will cause the debugger to return control to the user's program after 2953C<watchfunction()> executes: 2954 2955=over 4 2956 2957=item * 2958 2959Returning a false value from the C<watchfunction()> itself. 2960 2961=item * 2962 2963Altering C<$single> to a false value. 2964 2965=item * 2966 2967Altering C<$signal> to a false value. 2968 2969=item * 2970 2971Turning off the C<4> bit in C<$trace> (this also disables the 2972check for C<watchfunction()>. This can be done with 2973 2974 $trace &= ~4; 2975 2976=back 2977 2978=cut 2979 2980 # If there's a user-defined DB::watchfunction, call it with the 2981 # current package, filename, and line. The function executes in 2982 # the DB:: package. 2983 if ( $trace & 4 ) { # User-installed watch 2984 return 2985 if watchfunction( $package, $filename, $line ) 2986 and not $single 2987 and not $was_signal 2988 and not( $trace & ~4 ); 2989 } ## end if ($trace & 4) 2990 2991 # Pick up any alteration to $signal in the watchfunction, and 2992 # turn off the signal now. 2993 $was_signal = $signal; 2994 $signal = 0; 2995 2996=head2 GETTING READY TO EXECUTE COMMANDS 2997 2998The debugger decides to take control if single-step mode is on, the 2999C<t> command was entered, or the user generated a signal. If the program 3000has fallen off the end, we set things up so that entering further commands 3001won't cause trouble, and we say that the program is over. 3002 3003=cut 3004 3005 # Make sure that we always print if asked for explicitly regardless 3006 # of $trace_to_depth . 3007 $explicit_stop = ($single || $was_signal); 3008 3009 # Check to see if we should grab control ($single true, 3010 # trace set appropriately, or we got a signal). 3011 if ( $explicit_stop || ( $trace & 1 ) ) { 3012 $obj->_DB__grab_control(@_); 3013 } ## end if ($single || ($trace... 3014 3015=pod 3016 3017If there's an action to be executed for the line we stopped at, execute it. 3018If there are any preprompt actions, execute those as well. 3019 3020=cut 3021 3022 # If there's an action, do it now. 3023 if ($action) { 3024 $evalarg = $action; 3025 # The &-call is here to ascertain the mutability of @_. 3026 &DB::eval; 3027 } 3028 undef $action; 3029 3030 # Are we nested another level (e.g., did we evaluate a function 3031 # that had a breakpoint in it at the debugger prompt)? 3032 if ( $single || $was_signal ) { 3033 3034 # Yes, go down a level. 3035 local $level = $level + 1; 3036 3037 # Do any pre-prompt actions. 3038 foreach $evalarg (@$pre) { 3039 # The &-call is here to ascertain the mutability of @_. 3040 &DB::eval; 3041 } 3042 3043 # Complain about too much recursion if we passed the limit. 3044 if ($single & 4) { 3045 print $OUT $stack_depth . " levels deep in subroutine calls!\n"; 3046 } 3047 3048 # The line we're currently on. Set $incr to -1 to stay here 3049 # until we get a command that tells us to advance. 3050 $start = $line; 3051 $incr = -1; # for backward motion. 3052 3053 # Tack preprompt debugger actions ahead of any actual input. 3054 @typeahead = ( @$pretype, @typeahead ); 3055 3056=head2 WHERE ARE WE? 3057 3058XXX Relocate this section? 3059 3060The debugger normally shows the line corresponding to the current line of 3061execution. Sometimes, though, we want to see the next line, or to move elsewhere 3062in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables. 3063 3064C<$incr> controls by how many lines the I<current> line should move forward 3065after a command is executed. If set to -1, this indicates that the I<current> 3066line shouldn't change. 3067 3068C<$start> is the I<current> line. It is used for things like knowing where to 3069move forwards or backwards from when doing an C<L> or C<-> command. 3070 3071C<$max> tells the debugger where the last line of the current file is. It's 3072used to terminate loops most often. 3073 3074=head2 THE COMMAND LOOP 3075 3076Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes 3077in two parts: 3078 3079=over 4 3080 3081=item * 3082 3083The outer part of the loop, starting at the C<CMD> label. This loop 3084reads a command and then executes it. 3085 3086=item * 3087 3088The inner part of the loop, starting at the C<PIPE> label. This part 3089is wholly contained inside the C<CMD> block and only executes a command. 3090Used to handle commands running inside a pager. 3091 3092=back 3093 3094So why have two labels to restart the loop? Because sometimes, it's easier to 3095have a command I<generate> another command and then re-execute the loop to do 3096the new command. This is faster, but perhaps a bit more convoluted. 3097 3098=cut 3099 3100 # The big command dispatch loop. It keeps running until the 3101 # user yields up control again. 3102 # 3103 # If we have a terminal for input, and we get something back 3104 # from readline(), keep on processing. 3105 3106 CMD: 3107 while (_DB__read_next_cmd($tid)) 3108 { 3109 3110 share($cmd); 3111 # ... try to execute the input as debugger commands. 3112 3113 # Don't stop running. 3114 $single = 0; 3115 3116 # No signal is active. 3117 $signal = 0; 3118 3119 # Handle continued commands (ending with \): 3120 if ($cmd =~ s/\\\z/\n/) { 3121 $cmd .= DB::readline(" cont: "); 3122 redo CMD; 3123 } 3124 3125=head4 The null command 3126 3127A newline entered by itself means I<re-execute the last command>. We grab the 3128command out of C<$laststep> (where it was recorded previously), and copy it 3129back into C<$cmd> to be executed below. If there wasn't any previous command, 3130we'll do nothing below (no command will match). If there was, we also save it 3131in the command history and fall through to allow the command parsing to pick 3132it up. 3133 3134=cut 3135 3136 # Empty input means repeat the last command. 3137 if ($cmd eq '') { 3138 $cmd = $laststep; 3139 } 3140 chomp($cmd); # get rid of the annoying extra newline 3141 if (length($cmd) >= option_val('HistItemMinLength', 2)) { 3142 push( @hist, $cmd ); 3143 } 3144 push( @truehist, $cmd ); 3145 share(@hist); 3146 share(@truehist); 3147 3148 # This is a restart point for commands that didn't arrive 3149 # via direct user input. It allows us to 'redo PIPE' to 3150 # re-execute command processing without reading a new command. 3151 PIPE: { 3152 _DB__trim_command_and_return_first_component($obj); 3153 3154=head3 COMMAND ALIASES 3155 3156The debugger can create aliases for commands (these are stored in the 3157C<%alias> hash). Before a command is executed, the command loop looks it up 3158in the alias hash and substitutes the contents of the alias for the command, 3159completely replacing it. 3160 3161=cut 3162 3163 # See if there's an alias for the command, and set it up if so. 3164 if ( $alias{$cmd_verb} ) { 3165 3166 # Squelch signal handling; we want to keep control here 3167 # if something goes loco during the alias eval. 3168 local $SIG{__DIE__}; 3169 local $SIG{__WARN__}; 3170 3171 # This is a command, so we eval it in the DEBUGGER's 3172 # scope! Otherwise, we can't see the special debugger 3173 # variables, or get to the debugger's subs. (Well, we 3174 # _could_, but why make it even more complicated?) 3175 eval "\$cmd =~ $alias{$cmd_verb}"; 3176 if ($@) { 3177 local $\ = ''; 3178 print $OUT "Couldn't evaluate '$cmd_verb' alias: $@"; 3179 next CMD; 3180 } 3181 _DB__trim_command_and_return_first_component($obj); 3182 } ## end if ($alias{$cmd_verb}) 3183 3184=head3 MAIN-LINE COMMANDS 3185 3186All of these commands work up to and after the program being debugged has 3187terminated. 3188 3189=head4 C<q> - quit 3190 3191Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't 3192try to execute further, cleaning any restart-related stuff out of the 3193environment, and executing with the last value of C<$?>. 3194 3195=cut 3196 3197 # All of these commands were remapped in perl 5.8.0; 3198 # we send them off to the secondary dispatcher (see below). 3199 $obj->_handle_special_char_cmd_wrapper_commands; 3200 _DB__trim_command_and_return_first_component($obj); 3201 3202 if (my $cmd_rec = $cmd_lookup{$cmd_verb}) { 3203 my $type = $cmd_rec->{t}; 3204 my $val = $cmd_rec->{v}; 3205 if ($type eq 'm') { 3206 $obj->$val(); 3207 } 3208 elsif ($type eq 's') { 3209 $val->($obj); 3210 } 3211 } 3212 3213=head4 C<t> - trace [n] 3214 3215Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.). 3216If level is specified, set C<$trace_to_depth>. 3217 3218=head4 C<S> - list subroutines matching/not matching a pattern 3219 3220Walks through C<%sub>, checking to see whether or not to print the name. 3221 3222=head4 C<X> - list variables in current package 3223 3224Since the C<V> command actually processes this, just change this to the 3225appropriate C<V> command and fall through. 3226 3227=head4 C<V> - list variables 3228 3229Uses C<dumpvar.pl> to dump out the current values for selected variables. 3230 3231=head4 C<x> - evaluate and print an expression 3232 3233Hands the expression off to C<DB::eval>, setting it up to print the value 3234via C<dumpvar.pl> instead of just printing it directly. 3235 3236=head4 C<m> - print methods 3237 3238Just uses C<DB::methods> to determine what methods are available. 3239 3240=head4 C<f> - switch files 3241 3242Switch to a different filename. 3243 3244=head4 C<.> - return to last-executed line 3245 3246We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead, 3247and then we look up the line in the magical C<%dbline> hash. 3248 3249=head4 C<-> - back one window 3250 3251We change C<$start> to be one window back; if we go back past the first line, 3252we set it to be the first line. We set C<$incr> to put us back at the 3253currently-executing line, and then put a S<C<l $start +>> (list one window from 3254C<$start>) in C<$cmd> to be executed later. 3255 3256=head3 PRE-580 COMMANDS VS. NEW COMMANDS: C<a, A, b, B, h, l, L, M, o, O, P, v, w, W, E<lt>, E<lt>E<lt>, E<0x7B>, E<0x7B>E<0x7B>> 3257 3258In Perl 5.8.0, a realignment of the commands was done to fix up a number of 3259problems, most notably that the default case of several commands destroying 3260the user's work in setting watchpoints, actions, etc. We wanted, however, to 3261retain the old commands for those who were used to using them or who preferred 3262them. At this point, we check for the new commands and call C<cmd_wrapper> to 3263deal with them instead of processing them in-line. 3264 3265=head4 C<y> - List lexicals in higher scope 3266 3267Uses C<PadWalker> to find the lexicals supplied as arguments in a scope 3268above the current one and then displays them using F<dumpvar.pl>. 3269 3270=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS 3271 3272All of the commands below this point don't work after the program being 3273debugged has ended. All of them check to see if the program has ended; this 3274allows the commands to be relocated without worrying about a 'line of 3275demarcation' above which commands can be entered anytime, and below which 3276they can't. 3277 3278=head4 C<n> - single step, but don't trace down into subs 3279 3280Done by setting C<$single> to 2, which forces subs to execute straight through 3281when entered (see C<DB::sub> in L</DEBUGGER INTERFACE VARIABLES>). We also 3282save the C<n> command in C<$laststep>, 3283 3284so a null command knows what to re-execute. 3285 3286=head4 C<s> - single-step, entering subs 3287 3288Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside 3289subs. Also saves C<s> as C<$lastcmd>. 3290 3291=head4 C<c> - run continuously, setting an optional breakpoint 3292 3293Most of the code for this command is taken up with locating the optional 3294breakpoint, which is either a subroutine name or a line number. We set 3295the appropriate one-time-break in C<@dbline> and then turn off single-stepping 3296in this and all call levels above this one. 3297 3298=head4 C<r> - return from a subroutine 3299 3300For C<r> to work properly, the debugger has to stop execution again 3301immediately after the return is executed. This is done by forcing 3302single-stepping to be on in the call level above the current one. If 3303we are printing return values when a C<r> is executed, set C<$doret> 3304appropriately, and force us out of the command loop. 3305 3306=head4 C<T> - stack trace 3307 3308Just calls C<DB::print_trace>. 3309 3310=head4 C<w> - List window around current line 3311 3312Just calls C<DB::cmd_w>. 3313 3314=head4 C<W> - watch-expression processing 3315 3316Just calls C<DB::cmd_W>. 3317 3318=head4 C</> - search forward for a string in the source 3319 3320We take the argument and treat it as a pattern. If it turns out to be a 3321bad one, we return the error we got from trying to C<eval> it and exit. 3322If not, we create some code to do the search and C<eval> it so it can't 3323mess us up. 3324 3325=cut 3326 3327 _DB__handle_forward_slash_command($obj); 3328 3329=head4 C<?> - search backward for a string in the source 3330 3331Same as for C</>, except the loop runs backwards. 3332 3333=cut 3334 3335 _DB__handle_question_mark_command($obj); 3336 3337=head4 C<$rc> - Recall command 3338 3339Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports 3340that the terminal supports history). It finds the command required, puts it 3341into C<$cmd>, and redoes the loop to execute it. 3342 3343=cut 3344 3345 # $rc - recall command. 3346 $obj->_handle_rc_recall_command; 3347 3348=head4 C<$sh$sh> - C<system()> command 3349 3350Calls the C<_db_system()> to handle the command. This keeps the C<STDIN> and 3351C<STDOUT> from getting messed up. 3352 3353=cut 3354 3355 $obj->_handle_sh_command; 3356 3357=head4 C<$rc I<pattern> $rc> - Search command history 3358 3359Another command to manipulate C<@hist>: this one searches it with a pattern. 3360If a command is found, it is placed in C<$cmd> and executed via C<redo>. 3361 3362=cut 3363 3364 $obj->_handle_rc_search_history_command; 3365 3366=head4 C<$sh> - Invoke a shell 3367 3368Uses C<_db_system()> to invoke a shell. 3369 3370=cut 3371 3372=head4 C<$sh I<command>> - Force execution of a command in a shell 3373 3374Like the above, but the command is passed to the shell. Again, we use 3375C<_db_system()> to avoid problems with C<STDIN> and C<STDOUT>. 3376 3377=head4 C<H> - display commands in history 3378 3379Prints the contents of C<@hist> (if any). 3380 3381=head4 C<man, doc, perldoc> - look up documentation 3382 3383Just calls C<runman()> to print the appropriate document. 3384 3385=cut 3386 3387 $obj->_handle_doc_command; 3388 3389=head4 C<p> - print 3390 3391Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at 3392the bottom of the loop. 3393 3394=head4 C<=> - define command alias 3395 3396Manipulates C<%alias> to add or list command aliases. 3397 3398=head4 C<source> - read commands from a file 3399 3400Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will 3401pick it up. 3402 3403=head4 C<enable> C<disable> - enable or disable breakpoints 3404 3405This enables or disables breakpoints. 3406 3407=head4 C<save> - send current history to a file 3408 3409Takes the complete history, (not the shrunken version you see with C<H>), 3410and saves it to the given filename, so it can be replayed using C<source>. 3411 3412Note that all C<^(save|source)>'s are commented out with a view to minimise recursion. 3413 3414=head4 C<R> - restart 3415 3416Restart the debugger session. 3417 3418=head4 C<rerun> - rerun the current session 3419 3420Return to any given position in the B<true>-history list 3421 3422=head4 C<|, ||> - pipe output through the pager 3423 3424For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT> 3425(the program's standard output). For C<||>, we only save C<OUT>. We open a 3426pipe to the pager (restoring the output filehandles if this fails). If this 3427is the C<|> command, we also set up a C<SIGPIPE> handler which will simply 3428set C<$signal>, sending us back into the debugger. 3429 3430We then trim off the pipe symbols and C<redo> the command loop at the 3431C<PIPE> label, causing us to evaluate the command in C<$cmd> without 3432reading another. 3433 3434=cut 3435 3436 # || - run command in the pager, with output to DB::OUT. 3437 _DB__handle_run_command_in_pager_command($obj); 3438 3439=head3 END OF COMMAND PARSING 3440 3441Anything left in C<$cmd> at this point is a Perl expression that we want to 3442evaluate. We'll always evaluate in the user's context, and fully qualify 3443any variables we might want to address in the C<DB> package. 3444 3445=cut 3446 3447 } # PIPE: 3448 3449 # trace an expression 3450 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/; 3451 3452 # Make sure the flag that says "the debugger's running" is 3453 # still on, to make sure we get control again. 3454 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd"; 3455 3456 # Run *our* eval that executes in the caller's context. 3457 # The &-call is here to ascertain the mutability of @_. 3458 &DB::eval; 3459 3460 # Turn off the one-time-dump stuff now. 3461 if ($onetimeDump) { 3462 $onetimeDump = undef; 3463 $onetimedumpDepth = undef; 3464 } 3465 elsif ( $term_pid == $$ ) { 3466 eval { # May run under miniperl, when not available... 3467 STDOUT->flush(); 3468 STDERR->flush(); 3469 }; 3470 3471 # XXX If this is the master pid, print a newline. 3472 print {$OUT} "\n"; 3473 } 3474 } ## end while (($term || &setterm... 3475 3476=head3 POST-COMMAND PROCESSING 3477 3478After each command, we check to see if the command output was piped anywhere. 3479If so, we go through the necessary code to unhook the pipe and go back to 3480our standard filehandles for input and output. 3481 3482=cut 3483 3484 continue { # CMD: 3485 _DB__at_end_of_every_command($obj); 3486 } # CMD: 3487 3488=head3 COMMAND LOOP TERMINATION 3489 3490When commands have finished executing, we come here. If the user closed the 3491input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We 3492evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, 3493C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter. 3494The interpreter will then execute the next line and then return control to us 3495again. 3496 3497=cut 3498 3499 # No more commands? Quit. 3500 unless (defined $cmd) { 3501 DB::Obj::_do_quit(); 3502 } 3503 3504 # Evaluate post-prompt commands. 3505 foreach $evalarg (@$post) { 3506 # The &-call is here to ascertain the mutability of @_. 3507 &DB::eval; 3508 } 3509 } # if ($single || $signal) 3510 3511 # Put the user's globals back where you found them. 3512 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved; 3513 (); 3514} ## end sub DB 3515 3516# Because DB::Obj is used above, 3517# 3518# my $obj = DB::Obj->new( 3519# 3520# The following package declaration must come before that, 3521# or else runtime errors will occur with 3522# 3523# PERLDB_OPTS="autotrace nonstop" 3524# 3525# ( rt#116771 ) 3526BEGIN { 3527 3528package DB::Obj; 3529 3530sub new { 3531 my $class = shift; 3532 3533 my $self = bless {}, $class; 3534 3535 $self->_init(@_); 3536 3537 return $self; 3538} 3539 3540sub _init { 3541 my ($self, $args) = @_; 3542 3543 %{$self} = (%$self, %$args); 3544 3545 return; 3546} 3547 3548{ 3549 no strict 'refs'; 3550 foreach my $slot_name (qw( 3551 after explicit_stop infix pat piped position prefix selected cmd_verb 3552 cmd_args 3553 )) { 3554 my $slot = $slot_name; 3555 *{$slot} = sub { 3556 my $self = shift; 3557 3558 if (@_) { 3559 ${ $self->{$slot} } = shift; 3560 } 3561 3562 return ${ $self->{$slot} }; 3563 }; 3564 3565 *{"append_to_$slot"} = sub { 3566 my $self = shift; 3567 my $s = shift; 3568 3569 return $self->$slot($self->$slot . $s); 3570 }; 3571 } 3572} 3573 3574sub _DB_on_init__initialize_globals 3575{ 3576 my $self = shift; 3577 3578 # Check for whether we should be running continuously or not. 3579 # _After_ the perl program is compiled, $single is set to 1: 3580 if ( $single and not $second_time++ ) { 3581 3582 # Options say run non-stop. Run until we get an interrupt. 3583 if ($runnonstop) { # Disable until signal 3584 # If there's any call stack in place, turn off single 3585 # stepping into subs throughout the stack. 3586 for my $i (0 .. $stack_depth) { 3587 $stack[ $i ] &= ~1; 3588 } 3589 3590 # And we are now no longer in single-step mode. 3591 $single = 0; 3592 3593 # If we simply returned at this point, we wouldn't get 3594 # the trace info. Fall on through. 3595 # return; 3596 } ## end if ($runnonstop) 3597 3598 elsif ($ImmediateStop) { 3599 3600 # We are supposed to stop here; XXX probably a break. 3601 $ImmediateStop = 0; # We've processed it; turn it off 3602 $signal = 1; # Simulate an interrupt to force 3603 # us into the command loop 3604 } 3605 } ## end if ($single and not $second_time... 3606 3607 # If we're in single-step mode, or an interrupt (real or fake) 3608 # has occurred, turn off non-stop mode. 3609 $runnonstop = 0 if $single or $signal; 3610 3611 return; 3612} 3613 3614sub _my_print_lineinfo 3615{ 3616 my ($self, $i, $incr_pos) = @_; 3617 3618 if ($frame) { 3619 # Print it indented if tracing is on. 3620 DB::print_lineinfo( ' ' x $stack_depth, 3621 "$i:\t$DB::dbline[$i]" . $self->after ); 3622 } 3623 else { 3624 DB::depth_print_lineinfo($self->explicit_stop, $incr_pos); 3625 } 3626} 3627 3628sub _curr_line { 3629 return $DB::dbline[$line]; 3630} 3631 3632sub _is_full { 3633 my ($self, $letter) = @_; 3634 3635 return ($DB::cmd eq $letter); 3636} 3637 3638sub _DB__grab_control 3639{ 3640 my $self = shift; 3641 3642 # Yes, grab control. 3643 if ($client_editor) { 3644 3645 # Tell the editor to update its position. 3646 $self->position("$sub_twice${DB::filename}:$line:0\n"); 3647 DB::print_lineinfo($self->position()); 3648 } 3649 3650=pod 3651 3652Special check: if we're in package C<DB::fake>, we've gone through the 3653C<END> block at least once. We set up everything so that we can continue 3654to enter commands and have a valid context to be in. 3655 3656=cut 3657 3658 elsif ( $DB::package eq 'DB::fake' ) { 3659 3660 # Fallen off the end already. 3661 if (!$DB::term) { 3662 DB::setterm(); 3663 } 3664 3665 DB::print_help(<<EOP); 3666Debugged program terminated. Use B<q> to quit or B<R> to restart, 3667use B<o> I<inhibit_exit> to avoid stopping after program termination, 3668S<B<h q>>, S<B<h R>> or S<B<h o>> to get additional info. 3669EOP 3670 3671 $DB::package = 'main'; 3672 $DB::usercontext = DB::_calc_usercontext($DB::package); 3673 } ## end elsif ($package eq 'DB::fake') 3674 3675=pod 3676 3677If the program hasn't finished executing, we scan forward to the 3678next executable line, print that out, build the prompt from the file and line 3679number information, and print that. 3680 3681=cut 3682 3683 else { 3684 3685 3686 # Still somewhere in the midst of execution. Set up the 3687 # debugger prompt. 3688 $DB::sub =~ s/\'/::/; # Swap Perl 4 package separators (') to 3689 # Perl 5 ones (sorry, we don't print Klingon 3690 #module names) 3691 3692 $self->prefix($DB::sub =~ /::/ ? "" : ($DB::package . '::')); 3693 $self->append_to_prefix( "$DB::sub(${DB::filename}:" ); 3694 $self->after( $self->_curr_line =~ /\n$/ ? '' : "\n" ); 3695 3696 # Break up the prompt if it's really long. 3697 if ( length($self->prefix()) > 30 ) { 3698 $self->position($self->prefix . "$line):\n$line:\t" . $self->_curr_line . $self->after); 3699 $self->prefix(""); 3700 $self->infix(":\t"); 3701 } 3702 else { 3703 $self->infix("):\t"); 3704 $self->position( 3705 $self->prefix . $line. $self->infix 3706 . $self->_curr_line . $self->after 3707 ); 3708 } 3709 3710 # Print current line info, indenting if necessary. 3711 $self->_my_print_lineinfo($line, $self->position); 3712 3713 my $i; 3714 my $line_i = sub { return $DB::dbline[$i]; }; 3715 3716 # Scan forward, stopping at either the end or the next 3717 # unbreakable line. 3718 for ( $i = $line + 1 ; $i <= $DB::max && $line_i->() == 0 ; ++$i ) 3719 { #{ vi 3720 3721 # Drop out on null statements, block closers, and comments. 3722 last if $line_i->() =~ /^\s*[\;\}\#\n]/; 3723 3724 # Drop out if the user interrupted us. 3725 last if $signal; 3726 3727 # Append a newline if the line doesn't have one. Can happen 3728 # in eval'ed text, for instance. 3729 $self->after( $line_i->() =~ /\n$/ ? '' : "\n" ); 3730 3731 # Next executable line. 3732 my $incr_pos = $self->prefix . $i . $self->infix . $line_i->() 3733 . $self->after; 3734 $self->append_to_position($incr_pos); 3735 $self->_my_print_lineinfo($i, $incr_pos); 3736 } ## end for ($i = $line + 1 ; $i... 3737 } ## end else [ if ($client_editor) 3738 3739 return; 3740} 3741 3742sub _handle_t_command { 3743 my $self = shift; 3744 3745 my $levels = $self->cmd_args(); 3746 3747 if ((!length($levels)) or ($levels !~ /\D/)) { 3748 $trace ^= 1; 3749 local $\ = ''; 3750 $DB::trace_to_depth = $levels ? $stack_depth + $levels : 1E9; 3751 print {$OUT} "Trace = " 3752 . ( ( $trace & 1 ) 3753 ? ( $levels ? "on (to level $DB::trace_to_depth)" : "on" ) 3754 : "off" ) . "\n"; 3755 next CMD; 3756 } 3757 3758 return; 3759} 3760 3761 3762sub _handle_S_command { 3763 my $self = shift; 3764 3765 if (my ($print_all_subs, $should_reverse, $Spatt) 3766 = $self->cmd_args =~ /\A((!)?(.+))?\z/) { 3767 # $Spatt is the pattern (if any) to use. 3768 # Reverse scan? 3769 my $Srev = defined $should_reverse; 3770 # No args - print all subs. 3771 my $Snocheck = !defined $print_all_subs; 3772 3773 # Need to make these sane here. 3774 local $\ = ''; 3775 local $, = ''; 3776 3777 # Search through the debugger's magical hash of subs. 3778 # If $nocheck is true, just print the sub name. 3779 # Otherwise, check it against the pattern. We then use 3780 # the XOR trick to reverse the condition as required. 3781 foreach $subname ( sort( keys %sub ) ) { 3782 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) { 3783 print $OUT $subname, "\n"; 3784 } 3785 } 3786 next CMD; 3787 } 3788 3789 return; 3790} 3791 3792sub _handle_V_command_and_X_command { 3793 my $self = shift; 3794 3795 $DB::cmd =~ s/^X\b/V $DB::package/; 3796 3797 # Bare V commands get the currently-being-debugged package 3798 # added. 3799 if ($self->_is_full('V')) { 3800 $DB::cmd = "V $DB::package"; 3801 } 3802 3803 # V - show variables in package. 3804 if (my ($new_packname, $new_vars_str) = 3805 $DB::cmd =~ /\AV\b\s*(\S+)\s*(.*)/) { 3806 3807 # Save the currently selected filehandle and 3808 # force output to debugger's filehandle (dumpvar 3809 # just does "print" for output). 3810 my $savout = select($OUT); 3811 3812 # Grab package name and variables to dump. 3813 $packname = $new_packname; 3814 my @vars = split( ' ', $new_vars_str ); 3815 3816 # If main::dumpvar isn't here, get it. 3817 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; 3818 if ( defined &main::dumpvar ) { 3819 3820 # We got it. Turn off subroutine entry/exit messages 3821 # for the moment, along with return values. 3822 local $frame = 0; 3823 local $doret = -2; 3824 3825 # must detect sigpipe failures - not catching 3826 # then will cause the debugger to die. 3827 eval { 3828 main::dumpvar( 3829 $packname, 3830 defined $option{dumpDepth} 3831 ? $option{dumpDepth} 3832 : -1, # assume -1 unless specified 3833 @vars 3834 ); 3835 }; 3836 3837 # The die doesn't need to include the $@, because 3838 # it will automatically get propagated for us. 3839 if ($@) { 3840 die unless $@ =~ /dumpvar print failed/; 3841 } 3842 } ## end if (defined &main::dumpvar) 3843 else { 3844 3845 # Couldn't load dumpvar. 3846 print $OUT "dumpvar.pl not available.\n"; 3847 } 3848 3849 # Restore the output filehandle, and go round again. 3850 select($savout); 3851 next CMD; 3852 } 3853 3854 return; 3855} 3856 3857sub _handle_dash_command { 3858 my $self = shift; 3859 3860 if ($self->_is_full('-')) { 3861 3862 # back up by a window; go to 1 if back too far. 3863 $start -= $incr + $window + 1; 3864 $start = 1 if $start <= 0; 3865 $incr = $window - 1; 3866 3867 # Generate and execute a "l +" command (handled below). 3868 $DB::cmd = 'l ' . ($start) . '+'; 3869 redo CMD; 3870 } 3871 return; 3872} 3873 3874sub _n_or_s_commands_generic { 3875 my ($self, $new_val) = @_; 3876 # n - next 3877 next CMD if DB::_DB__is_finished(); 3878 3879 # Single step, but don't enter subs. 3880 $single = $new_val; 3881 3882 # Save for empty command (repeat last). 3883 $laststep = $DB::cmd; 3884 last CMD; 3885} 3886 3887sub _n_or_s { 3888 my ($self, $letter, $new_val) = @_; 3889 3890 if ($self->_is_full($letter)) { 3891 $self->_n_or_s_commands_generic($new_val); 3892 } 3893 else { 3894 $self->_n_or_s_and_arg_commands_generic($letter, $new_val); 3895 } 3896 3897 return; 3898} 3899 3900sub _handle_n_command { 3901 my $self = shift; 3902 3903 return $self->_n_or_s('n', 2); 3904} 3905 3906sub _handle_s_command { 3907 my $self = shift; 3908 3909 return $self->_n_or_s('s', 1); 3910} 3911 3912sub _handle_r_command { 3913 my $self = shift; 3914 3915 # r - return from the current subroutine. 3916 if ($self->_is_full('r')) { 3917 3918 # Can't do anything if the program's over. 3919 next CMD if DB::_DB__is_finished(); 3920 3921 # Turn on stack trace. 3922 $stack[$stack_depth] |= 1; 3923 3924 # Print return value unless the stack is empty. 3925 $doret = $option{PrintRet} ? $stack_depth - 1 : -2; 3926 last CMD; 3927 } 3928 3929 return; 3930} 3931 3932sub _handle_T_command { 3933 my $self = shift; 3934 3935 if ($self->_is_full('T')) { 3936 DB::print_trace( $OUT, 1 ); # skip DB 3937 next CMD; 3938 } 3939 3940 return; 3941} 3942 3943sub _handle_w_command { 3944 my $self = shift; 3945 3946 DB::cmd_w( 'w', $self->cmd_args() ); 3947 next CMD; 3948 3949 return; 3950} 3951 3952sub _handle_W_command { 3953 my $self = shift; 3954 3955 if (my $arg = $self->cmd_args) { 3956 DB::cmd_W( 'W', $arg ); 3957 next CMD; 3958 } 3959 3960 return; 3961} 3962 3963sub _handle_rc_recall_command { 3964 my $self = shift; 3965 3966 # $rc - recall command. 3967 if (my ($minus, $arg) = $DB::cmd =~ m#\A$rc+\s*(-)?(\d+)?\z#) { 3968 3969 # No arguments, take one thing off history. 3970 pop(@hist) if length($DB::cmd) > 1; 3971 3972 # Relative (- found)? 3973 # Y - index back from most recent (by 1 if bare minus) 3974 # N - go to that particular command slot or the last 3975 # thing if nothing following. 3976 3977 $self->cmd_verb( 3978 scalar($minus ? ( $#hist - ( $arg || 1 ) ) : ( $arg || $#hist )) 3979 ); 3980 3981 # Pick out the command desired. 3982 $DB::cmd = $hist[$self->cmd_verb]; 3983 3984 # Print the command to be executed and restart the loop 3985 # with that command in the buffer. 3986 print {$OUT} $DB::cmd, "\n"; 3987 redo CMD; 3988 } 3989 3990 return; 3991} 3992 3993sub _handle_rc_search_history_command { 3994 my $self = shift; 3995 3996 # $rc pattern $rc - find a command in the history. 3997 if (my ($arg) = $DB::cmd =~ /\A$rc([^$rc].*)\z/) { 3998 3999 # Create the pattern to use. 4000 my $pat = "^$arg"; 4001 $self->pat($pat); 4002 4003 # Toss off last entry if length is >1 (and it always is). 4004 pop(@hist) if length($DB::cmd) > 1; 4005 4006 my $i; 4007 4008 # Look backward through the history. 4009 SEARCH_HIST: 4010 for ( $i = $#hist ; $i ; --$i ) { 4011 # Stop if we find it. 4012 last SEARCH_HIST if $hist[$i] =~ /$pat/; 4013 } 4014 4015 if ( !$i ) { 4016 4017 # Never found it. 4018 print $OUT "No such command!\n\n"; 4019 next CMD; 4020 } 4021 4022 # Found it. Put it in the buffer, print it, and process it. 4023 $DB::cmd = $hist[$i]; 4024 print $OUT $DB::cmd, "\n"; 4025 redo CMD; 4026 } 4027 4028 return; 4029} 4030 4031sub _handle_H_command { 4032 my $self = shift; 4033 4034 if ($self->cmd_args =~ m#\A\*#) { 4035 @hist = @truehist = (); 4036 print $OUT "History cleansed\n"; 4037 next CMD; 4038 } 4039 4040 if (my ($num) = $self->cmd_args =~ /\A(?:-(\d+))?/) { 4041 4042 # Anything other than negative numbers is ignored by 4043 # the (incorrect) pattern, so this test does nothing. 4044 $end = $num ? ( $#hist - $num ) : 0; 4045 4046 # Set to the minimum if less than zero. 4047 $hist = 0 if $hist < 0; 4048 4049 # Start at the end of the array. 4050 # Stay in while we're still above the ending value. 4051 # Tick back by one each time around the loop. 4052 my $i; 4053 4054 for ( $i = $#hist ; $i > $end ; $i-- ) { 4055 print $OUT "$i: ", $hist[$i], "\n"; 4056 } 4057 4058 next CMD; 4059 } 4060 4061 return; 4062} 4063 4064sub _handle_doc_command { 4065 my $self = shift; 4066 4067 # man, perldoc, doc - show manual pages. 4068 if (my ($man_page) 4069 = $DB::cmd =~ /\A(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?\z/) { 4070 DB::runman($man_page); 4071 next CMD; 4072 } 4073 4074 return; 4075} 4076 4077sub _handle_p_command { 4078 my $self = shift; 4079 4080 my $print_cmd = 'print {$DB::OUT} '; 4081 # p - print (no args): print $_. 4082 if ($self->_is_full('p')) { 4083 $DB::cmd = $print_cmd . '$_'; 4084 } 4085 else { 4086 # p - print the given expression. 4087 $DB::cmd =~ s/\Ap\b/$print_cmd /; 4088 } 4089 4090 return; 4091} 4092 4093sub _handle_equal_sign_command { 4094 my $self = shift; 4095 4096 if ($DB::cmd =~ s/\A=\s*//) { 4097 my @keys; 4098 if ( length $DB::cmd == 0 ) { 4099 4100 # No args, get current aliases. 4101 @keys = sort keys %alias; 4102 } 4103 elsif ( my ( $k, $v ) = ( $DB::cmd =~ /^(\S+)\s+(\S.*)/ ) ) { 4104 4105 # Creating a new alias. $k is alias name, $v is 4106 # alias value. 4107 4108 # can't use $_ or kill //g state 4109 for my $x ( $k, $v ) { 4110 4111 # Escape "alarm" characters. 4112 $x =~ s/\a/\\a/g; 4113 } 4114 4115 # Substitute key for value, using alarm chars 4116 # as separators (which is why we escaped them in 4117 # the command). 4118 $alias{$k} = "s\a$k\a$v\a"; 4119 4120 # Turn off standard warn and die behavior. 4121 local $SIG{__DIE__}; 4122 local $SIG{__WARN__}; 4123 4124 # Is it valid Perl? 4125 unless ( eval "sub { s\a$k\a$v\a }; 1" ) { 4126 4127 # Nope. Bad alias. Say so and get out. 4128 print $OUT "Can't alias $k to $v: $@\n"; 4129 delete $alias{$k}; 4130 next CMD; 4131 } 4132 4133 # We'll only list the new one. 4134 @keys = ($k); 4135 } ## end elsif (my ($k, $v) = ($DB::cmd... 4136 4137 # The argument is the alias to list. 4138 else { 4139 @keys = ($DB::cmd); 4140 } 4141 4142 # List aliases. 4143 for my $k (@keys) { 4144 4145 # Messy metaquoting: Trim the substitution code off. 4146 # We use control-G as the delimiter because it's not 4147 # likely to appear in the alias. 4148 if ( ( my $v = $alias{$k} ) =~ ss\a$k\a(.*)\a$1 ) { 4149 4150 # Print the alias. 4151 print $OUT "$k\t= $1\n"; 4152 } 4153 elsif ( defined $alias{$k} ) { 4154 4155 # Couldn't trim it off; just print the alias code. 4156 print $OUT "$k\t$alias{$k}\n"; 4157 } 4158 else { 4159 4160 # No such, dude. 4161 print "No alias for $k\n"; 4162 } 4163 } ## end for my $k (@keys) 4164 next CMD; 4165 } 4166 4167 return; 4168} 4169 4170sub _handle_source_command { 4171 my $self = shift; 4172 4173 # source - read commands from a file (or pipe!) and execute. 4174 if (my $sourced_fn = $self->cmd_args) { 4175 if ( open my $fh, $sourced_fn ) { 4176 4177 # Opened OK; stick it in the list of file handles. 4178 push @cmdfhs, $fh; 4179 } 4180 else { 4181 4182 # Couldn't open it. 4183 DB::_db_warn("Can't execute '$sourced_fn': $!\n"); 4184 } 4185 next CMD; 4186 } 4187 4188 return; 4189} 4190 4191sub _handle_enable_disable_commands { 4192 my $self = shift; 4193 4194 my $which_cmd = $self->cmd_verb; 4195 my $position = $self->cmd_args; 4196 4197 if ($position !~ /\s/) { 4198 my ($fn, $line_num); 4199 if ($position =~ m{\A\d+\z}) 4200 { 4201 $fn = $DB::filename; 4202 $line_num = $position; 4203 } 4204 elsif (my ($new_fn, $new_line_num) 4205 = $position =~ m{\A(.*):(\d+)\z}) { 4206 ($fn, $line_num) = ($new_fn, $new_line_num); 4207 } 4208 else 4209 { 4210 DB::_db_warn("Wrong spec for enable/disable argument.\n"); 4211 } 4212 4213 if (defined($fn)) { 4214 if (DB::_has_breakpoint_data_ref($fn, $line_num)) { 4215 DB::_set_breakpoint_enabled_status($fn, $line_num, 4216 ($which_cmd eq 'enable' ? 1 : '') 4217 ); 4218 } 4219 else { 4220 DB::_db_warn("No breakpoint set at ${fn}:${line_num}\n"); 4221 } 4222 } 4223 4224 next CMD; 4225 } 4226 4227 return; 4228} 4229 4230sub _handle_save_command { 4231 my $self = shift; 4232 4233 if (my $new_fn = $self->cmd_args) { 4234 my $filename = $new_fn || '.perl5dbrc'; # default? 4235 if ( open my $fh, '>', $filename ) { 4236 4237 # chomp to remove extraneous newlines from source'd files 4238 chomp( my @truelist = 4239 map { m/\A\s*(save|source)/ ? "#$_" : $_ } 4240 @truehist ); 4241 print {$fh} join( "\n", @truelist ); 4242 print "commands saved in $filename\n"; 4243 } 4244 else { 4245 DB::_db_warn("Can't save debugger commands in '$new_fn': $!\n"); 4246 } 4247 next CMD; 4248 } 4249 4250 return; 4251} 4252 4253sub _n_or_s_and_arg_commands_generic { 4254 my ($self, $letter, $new_val) = @_; 4255 4256 # s - single-step. Remember the last command was 's'. 4257 if ($DB::cmd =~ s#\A\Q$letter\E\s#\$DB::single = $new_val;\n#) { 4258 $laststep = $letter; 4259 } 4260 4261 return; 4262} 4263 4264sub _handle_sh_command { 4265 my $self = shift; 4266 4267 # $sh$sh - run a shell command (if it's all ASCII). 4268 # Can't run shell commands with Unicode in the debugger, hmm. 4269 my $my_cmd = $DB::cmd; 4270 if ($my_cmd =~ m#\A$sh#gms) { 4271 4272 if ($my_cmd =~ m#\G\z#cgms) { 4273 # Run the user's shell. If none defined, run Bourne. 4274 # We resume execution when the shell terminates. 4275 DB::_db_system( $ENV{SHELL} || "/bin/sh" ); 4276 next CMD; 4277 } 4278 elsif ($my_cmd =~ m#\G$sh\s*(.*)#cgms) { 4279 # System it. 4280 DB::_db_system($1); 4281 next CMD; 4282 } 4283 elsif ($my_cmd =~ m#\G\s*(.*)#cgms) { 4284 DB::_db_system( $ENV{SHELL} || "/bin/sh", "-c", $1 ); 4285 next CMD; 4286 } 4287 } 4288} 4289 4290sub _handle_x_command { 4291 my $self = shift; 4292 4293 if ($DB::cmd =~ s#\Ax\b# #) { # Remainder gets done by DB::eval() 4294 $onetimeDump = 'dump'; # main::dumpvar shows the output 4295 4296 # handle special "x 3 blah" syntax XXX propagate 4297 # doc back to special variables. 4298 if ( $DB::cmd =~ s#\A\s*(\d+)(?=\s)# #) { 4299 $onetimedumpDepth = $1; 4300 } 4301 } 4302 4303 return; 4304} 4305 4306sub _do_quit { 4307 $fall_off_end = 1; 4308 DB::clean_ENV(); 4309 exit $?; 4310} 4311 4312sub _handle_q_command { 4313 my $self = shift; 4314 4315 if ($self->_is_full('q')) { 4316 _do_quit(); 4317 } 4318 4319 return; 4320} 4321 4322sub _handle_cmd_wrapper_commands { 4323 my $self = shift; 4324 4325 DB::cmd_wrapper( $self->cmd_verb, $self->cmd_args, $line ); 4326 next CMD; 4327} 4328 4329sub _handle_special_char_cmd_wrapper_commands { 4330 my $self = shift; 4331 4332 # All of these commands were remapped in perl 5.8.0; 4333 # we send them off to the secondary dispatcher (see below). 4334 if (my ($cmd_letter, $my_arg) = $DB::cmd =~ /\A([<>\{]{1,2})\s*(.*)/so) { 4335 DB::cmd_wrapper( $cmd_letter, $my_arg, $line ); 4336 next CMD; 4337 } 4338 4339 return; 4340} 4341 4342} ## end DB::Obj 4343 4344package DB; 4345 4346# The following code may be executed now: 4347# BEGIN {warn 4} 4348 4349=head2 sub 4350 4351C<sub> is called whenever a subroutine call happens in the program being 4352debugged. The variable C<$DB::sub> contains the name of the subroutine 4353being called. 4354 4355The core function of this subroutine is to actually call the sub in the proper 4356context, capturing its output. This of course causes C<DB::DB> to get called 4357again, repeating until the subroutine ends and returns control to C<DB::sub> 4358again. Once control returns, C<DB::sub> figures out whether or not to dump the 4359return value, and returns its captured copy of the return value as its own 4360return value. The value then feeds back into the program being debugged as if 4361C<DB::sub> hadn't been there at all. 4362 4363C<sub> does all the work of printing the subroutine entry and exit messages 4364enabled by setting C<$frame>. It notes what sub the autoloader got called for, 4365and also prints the return value if needed (for the C<r> command and if 4366the 16 bit is set in C<$frame>). 4367 4368It also tracks the subroutine call depth by saving the current setting of 4369C<$single> in the C<@stack> package global; if this exceeds the value in 4370C<$deep>, C<sub> automatically turns on printing of the current depth by 4371setting the C<4> bit in C<$single>. In any case, it keeps the current setting 4372of stop/don't stop on entry to subs set as it currently is set. 4373 4374=head3 C<caller()> support 4375 4376If C<caller()> is called from the package C<DB>, it provides some 4377additional data, in the following order: 4378 4379=over 4 4380 4381=item * C<$package> 4382 4383The package name the sub was in 4384 4385=item * C<$filename> 4386 4387The filename it was defined in 4388 4389=item * C<$line> 4390 4391The line number it was defined on 4392 4393=item * C<$subroutine> 4394 4395The subroutine name; C<(eval)> if an C<eval>(). 4396 4397=item * C<$hasargs> 4398 43991 if it has arguments, 0 if not 4400 4401=item * C<$wantarray> 4402 44031 if array context, 0 if scalar context 4404 4405=item * C<$evaltext> 4406 4407The C<eval>() text, if any (undefined for S<C<eval BLOCK>>) 4408 4409=item * C<$is_require> 4410 4411frame was created by a C<use> or C<require> statement 4412 4413=item * C<$hints> 4414 4415pragma information; subject to change between versions 4416 4417=item * C<$bitmask> 4418 4419pragma information; subject to change between versions 4420 4421=item * C<@DB::args> 4422 4423arguments with which the subroutine was invoked 4424 4425=back 4426 4427=cut 4428 4429use vars qw($deep); 4430 4431# We need to fully qualify the name ("DB::sub") to make "use strict;" 4432# happy. -- Shlomi Fish 4433 4434sub _indent_print_line_info { 4435 my ($offset, $str) = @_; 4436 4437 print_lineinfo( ' ' x ($stack_depth - $offset), $str); 4438 4439 return; 4440} 4441 4442sub _print_frame_message { 4443 my ($al) = @_; 4444 4445 if ($frame) { 4446 if ($frame & 4) { # Extended frame entry message 4447 _indent_print_line_info(-1, "in "); 4448 4449 # Why -1? But it works! :-( 4450 # Because print_trace will call add 1 to it and then call 4451 # dump_trace; this results in our skipping -1+1 = 0 stack frames 4452 # in dump_trace. 4453 # 4454 # Now it's 0 because we extracted a function. 4455 print_trace( $LINEINFO, 0, 1, 1, "$sub$al" ); 4456 } 4457 else { 4458 _indent_print_line_info(-1, "entering $sub$al\n" ); 4459 } 4460 } 4461 4462 return; 4463} 4464 4465sub DB::sub { 4466 my ( $al, $ret, @ret ) = ""; 4467 4468 # We stack the stack pointer and then increment it to protect us 4469 # from a situation that might unwind a whole bunch of call frames 4470 # at once. Localizing the stack pointer means that it will automatically 4471 # unwind the same amount when multiple stack frames are unwound. 4472 local $stack_depth = $stack_depth + 1; # Protect from non-local exits 4473 4474 { 4475 # lock ourselves under threads 4476 # While lock() permits recursive locks, there's two cases where it's bad 4477 # that we keep a hold on the lock while we call the sub: 4478 # - during cloning, Package::CLONE might be called in the context of the new 4479 # thread, which will deadlock if we hold the lock across the threads::new call 4480 # - for any function that waits any significant time 4481 # This also deadlocks if the parent thread joins(), since holding the lock 4482 # will prevent any child threads passing this point. 4483 # So release the lock for the function call. 4484 lock($DBGR); 4485 4486 # Whether or not the autoloader was running, a scalar to put the 4487 # sub's return value in (if needed), and an array to put the sub's 4488 # return value in (if needed). 4489 if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) { 4490 print "creating new thread\n"; 4491 } 4492 4493 # If the last ten characters are '::AUTOLOAD', note we've traced 4494 # into AUTOLOAD for $sub. 4495 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { 4496 no strict 'refs'; 4497 $al = " for $$sub" if defined $$sub; 4498 } 4499 4500 # Expand @stack. 4501 $#stack = $stack_depth; 4502 4503 # Save current single-step setting. 4504 $stack[-1] = $single; 4505 4506 # Turn off all flags except single-stepping. 4507 $single &= 1; 4508 4509 # If we've gotten really deeply recursed, turn on the flag that will 4510 # make us stop with the 'deep recursion' message. 4511 $single |= 4 if $stack_depth == $deep; 4512 4513 # If frame messages are on ... 4514 4515 _print_frame_message($al); 4516 } 4517 4518 # Determine the sub's return type, and capture appropriately. 4519 if (wantarray) { 4520 4521 # Called in array context. call sub and capture output. 4522 # DB::DB will recursively get control again if appropriate; we'll come 4523 # back here when the sub is finished. 4524 no strict 'refs'; 4525 @ret = &$sub; 4526 } 4527 elsif ( defined wantarray ) { 4528 no strict 'refs'; 4529 # Save the value if it's wanted at all. 4530 $ret = &$sub; 4531 } 4532 else { 4533 no strict 'refs'; 4534 # Void return, explicitly. 4535 &$sub; 4536 undef $ret; 4537 } 4538 4539 { 4540 lock($DBGR); 4541 4542 # Pop the single-step value back off the stack. 4543 $single |= $stack[ $stack_depth-- ]; 4544 4545 if ($frame & 2) { 4546 if ($frame & 4) { # Extended exit message 4547 _indent_print_line_info(0, "out "); 4548 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ); 4549 } 4550 else { 4551 _indent_print_line_info(0, "exited $sub$al\n" ); 4552 } 4553 } 4554 4555 if (wantarray) { 4556 # Print the return info if we need to. 4557 if ( $doret eq $stack_depth or $frame & 16 ) { 4558 4559 # Turn off output record separator. 4560 local $\ = ''; 4561 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 4562 4563 # Indent if we're printing because of $frame tracing. 4564 if ($frame & 16) 4565 { 4566 print {$fh} ' ' x $stack_depth; 4567 } 4568 4569 # Print the return value. 4570 print {$fh} "list context return from $sub:\n"; 4571 dumpit( $fh, \@ret ); 4572 4573 # And don't print it again. 4574 $doret = -2; 4575 } ## end if ($doret eq $stack_depth... 4576 # And we have to return the return value now. 4577 @ret; 4578 } ## end if (wantarray) 4579 # Scalar context. 4580 else { 4581 # If we are supposed to show the return value... same as before. 4582 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) { 4583 local $\ = ''; 4584 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 4585 print $fh ( ' ' x $stack_depth ) if $frame & 16; 4586 print $fh ( 4587 defined wantarray 4588 ? "scalar context return from $sub: " 4589 : "void context return from $sub\n" 4590 ); 4591 dumpit( $fh, $ret ) if defined wantarray; 4592 $doret = -2; 4593 } ## end if ($doret eq $stack_depth... 4594 4595 # Return the appropriate scalar value. 4596 $ret; 4597 } ## end else [ if (wantarray) 4598 } 4599} ## end sub _sub 4600 4601sub lsub : lvalue { 4602 4603 # We stack the stack pointer and then increment it to protect us 4604 # from a situation that might unwind a whole bunch of call frames 4605 # at once. Localizing the stack pointer means that it will automatically 4606 # unwind the same amount when multiple stack frames are unwound. 4607 local $stack_depth = $stack_depth + 1; # Protect from non-local exits 4608 4609 # Expand @stack. 4610 $#stack = $stack_depth; 4611 4612 # Save current single-step setting. 4613 $stack[-1] = $single; 4614 4615 # Turn off all flags except single-stepping. 4616 # Use local so the single-step value is popped back off the 4617 # stack for us. 4618 local $single = $single & 1; 4619 4620 no strict 'refs'; 4621 { 4622 # lock ourselves under threads 4623 lock($DBGR); 4624 4625 # Whether or not the autoloader was running, a scalar to put the 4626 # sub's return value in (if needed), and an array to put the sub's 4627 # return value in (if needed). 4628 my ( $al, $ret, @ret ) = ""; 4629 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) { 4630 print "creating new thread\n"; 4631 } 4632 4633 # If the last ten characters are C'::AUTOLOAD', note we've traced 4634 # into AUTOLOAD for $sub. 4635 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { 4636 $al = " for $$sub"; 4637 } 4638 4639 # If we've gotten really deeply recursed, turn on the flag that will 4640 # make us stop with the 'deep recursion' message. 4641 $single |= 4 if $stack_depth == $deep; 4642 4643 # If frame messages are on ... 4644 _print_frame_message($al); 4645 } 4646 4647 # call the original lvalue sub. 4648 &$sub; 4649} 4650 4651# Abstracting common code from multiple places elsewhere: 4652sub depth_print_lineinfo { 4653 my $always_print = shift; 4654 4655 print_lineinfo( @_ ) if ($always_print or $stack_depth < $trace_to_depth); 4656} 4657 4658=head1 EXTENDED COMMAND HANDLING AND THE COMMAND API 4659 4660In Perl 5.8.0, there was a major realignment of the commands and what they did, 4661Most of the changes were to systematize the command structure and to eliminate 4662commands that threw away user input without checking. 4663 4664The following sections describe the code added to make it easy to support 4665multiple command sets with conflicting command names. This section is a start 4666at unifying all command processing to make it simpler to develop commands. 4667 4668Note that all the cmd_[a-zA-Z] subroutines require the command name, a line 4669number, and C<$dbline> (the current line) as arguments. 4670 4671Support functions in this section which have multiple modes of failure C<die> 4672on error; the rest simply return a false value. 4673 4674The user-interface functions (all of the C<cmd_*> functions) just output 4675error messages. 4676 4677=head2 C<%set> 4678 4679The C<%set> hash defines the mapping from command letter to subroutine 4680name suffix. 4681 4682C<%set> is a two-level hash, indexed by set name and then by command name. 4683Note that trying to set the CommandSet to C<foobar> simply results in the 46845.8.0 command set being used, since there's no top-level entry for C<foobar>. 4685 4686=cut 4687 4688### The API section 4689 4690my %set = ( # 4691 'pre580' => { 4692 'a' => 'pre580_a', 4693 'A' => 'pre580_null', 4694 'b' => 'pre580_b', 4695 'B' => 'pre580_null', 4696 'd' => 'pre580_null', 4697 'D' => 'pre580_D', 4698 'h' => 'pre580_h', 4699 'M' => 'pre580_null', 4700 'O' => 'o', 4701 'o' => 'pre580_null', 4702 'v' => 'M', 4703 'w' => 'v', 4704 'W' => 'pre580_W', 4705 }, 4706 'pre590' => { 4707 '<' => 'pre590_prepost', 4708 '<<' => 'pre590_prepost', 4709 '>' => 'pre590_prepost', 4710 '>>' => 'pre590_prepost', 4711 '{' => 'pre590_prepost', 4712 '{{' => 'pre590_prepost', 4713 }, 4714); 4715 4716my %breakpoints_data; 4717 4718sub _has_breakpoint_data_ref { 4719 my ($filename, $line) = @_; 4720 4721 return ( 4722 exists( $breakpoints_data{$filename} ) 4723 and 4724 exists( $breakpoints_data{$filename}{$line} ) 4725 ); 4726} 4727 4728sub _get_breakpoint_data_ref { 4729 my ($filename, $line) = @_; 4730 4731 return ($breakpoints_data{$filename}{$line} ||= +{}); 4732} 4733 4734sub _delete_breakpoint_data_ref { 4735 my ($filename, $line) = @_; 4736 4737 delete($breakpoints_data{$filename}{$line}); 4738 if (! scalar(keys( %{$breakpoints_data{$filename}} )) ) { 4739 delete($breakpoints_data{$filename}); 4740 } 4741 4742 return; 4743} 4744 4745sub _set_breakpoint_enabled_status { 4746 my ($filename, $line, $status) = @_; 4747 4748 _get_breakpoint_data_ref($filename, $line)->{'enabled'} = 4749 ($status ? 1 : '') 4750 ; 4751 4752 return; 4753} 4754 4755sub _enable_breakpoint_temp_enabled_status { 4756 my ($filename, $line) = @_; 4757 4758 _get_breakpoint_data_ref($filename, $line)->{'temp_enabled'} = 1; 4759 4760 return; 4761} 4762 4763sub _cancel_breakpoint_temp_enabled_status { 4764 my ($filename, $line) = @_; 4765 4766 my $ref = _get_breakpoint_data_ref($filename, $line); 4767 4768 delete ($ref->{'temp_enabled'}); 4769 4770 if (! %$ref) { 4771 _delete_breakpoint_data_ref($filename, $line); 4772 } 4773 4774 return; 4775} 4776 4777sub _is_breakpoint_enabled { 4778 my ($filename, $line) = @_; 4779 4780 my $data_ref = _get_breakpoint_data_ref($filename, $line); 4781 return ($data_ref->{'enabled'} || $data_ref->{'temp_enabled'}); 4782} 4783 4784=head2 C<cmd_wrapper()> (API) 4785 4786C<cmd_wrapper()> allows the debugger to switch command sets 4787depending on the value of the C<CommandSet> option. 4788 4789It tries to look up the command in the C<%set> package-level I<lexical> 4790(which means external entities can't fiddle with it) and create the name of 4791the sub to call based on the value found in the hash (if it's there). I<All> 4792of the commands to be handled in a set have to be added to C<%set>; if they 4793aren't found, the 5.8.0 equivalent is called (if there is one). 4794 4795This code uses symbolic references. 4796 4797=cut 4798 4799sub cmd_wrapper { 4800 my $cmd = shift; 4801 my $line = shift; 4802 my $dblineno = shift; 4803 4804 # Assemble the command subroutine's name by looking up the 4805 # command set and command name in %set. If we can't find it, 4806 # default to the older version of the command. 4807 my $call = 'cmd_' 4808 . ( $set{$CommandSet}{$cmd} 4809 || ( $cmd =~ /\A[<>{]+/o ? 'prepost' : $cmd ) ); 4810 4811 # Call the command subroutine, call it by name. 4812 return __PACKAGE__->can($call)->( $cmd, $line, $dblineno ); 4813} ## end sub cmd_wrapper 4814 4815=head3 C<cmd_a> (command) 4816 4817The C<a> command handles pre-execution actions. These are associated with a 4818particular line, so they're stored in C<%dbline>. We default to the current 4819line if none is specified. 4820 4821=cut 4822 4823sub cmd_a { 4824 my $cmd = shift; 4825 my $line = shift || ''; # [.|line] expr 4826 my $dbline = shift; 4827 4828 # If it's dot (here), or not all digits, use the current line. 4829 $line =~ s/\A\./$dbline/; 4830 4831 # Should be a line number followed by an expression. 4832 if ( my ($lineno, $expr) = $line =~ /^\s*(\d*)\s*(\S.+)/ ) { 4833 4834 if (! length($lineno)) { 4835 $lineno = $dbline; 4836 } 4837 4838 # If we have an expression ... 4839 if ( length $expr ) { 4840 4841 # ... but the line isn't breakable, complain. 4842 if ( $dbline[$lineno] == 0 ) { 4843 print $OUT 4844 "Line $lineno($dbline[$lineno]) does not have an action?\n"; 4845 } 4846 else { 4847 4848 # It's executable. Record that the line has an action. 4849 $had_breakpoints{$filename} |= 2; 4850 4851 # Remove any action, temp breakpoint, etc. 4852 $dbline{$lineno} =~ s/\0[^\0]*//; 4853 4854 # Add the action to the line. 4855 $dbline{$lineno} .= "\0" . action($expr); 4856 4857 _set_breakpoint_enabled_status($filename, $lineno, 1); 4858 } 4859 } ## end if (length $expr) 4860 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/) 4861 else { 4862 4863 # Syntax wrong. 4864 print $OUT 4865 "Adding an action requires an optional lineno and an expression\n" 4866 ; # hint 4867 } 4868} ## end sub cmd_a 4869 4870=head3 C<cmd_A> (command) 4871 4872Delete actions. Similar to above, except the delete code is in a separate 4873subroutine, C<delete_action>. 4874 4875=cut 4876 4877sub cmd_A { 4878 my $cmd = shift; 4879 my $line = shift || ''; 4880 my $dbline = shift; 4881 4882 # Dot is this line. 4883 $line =~ s/^\./$dbline/; 4884 4885 # Call delete_action with a null param to delete them all. 4886 # The '1' forces the eval to be true. It'll be false only 4887 # if delete_action blows up for some reason, in which case 4888 # we print $@ and get out. 4889 if ( $line eq '*' ) { 4890 if (! eval { _delete_all_actions(); 1 }) { 4891 print {$OUT} $@; 4892 return; 4893 } 4894 } 4895 4896 # There's a real line number. Pass it to delete_action. 4897 # Error trapping is as above. 4898 elsif ( $line =~ /^(\S.*)/ ) { 4899 if (! eval { delete_action($1); 1 }) { 4900 print {$OUT} $@; 4901 return; 4902 } 4903 } 4904 4905 # Swing and a miss. Bad syntax. 4906 else { 4907 print $OUT 4908 "Deleting an action requires a line number, or '*' for all\n" ; # hint 4909 } 4910} ## end sub cmd_A 4911 4912=head3 C<delete_action> (API) 4913 4914C<delete_action> accepts either a line number or C<undef>. If a line number 4915is specified, we check for the line being executable (if it's not, it 4916couldn't have had an action). If it is, we just take the action off (this 4917will get any kind of an action, including breakpoints). 4918 4919=cut 4920 4921sub _remove_action_from_dbline { 4922 my $i = shift; 4923 4924 $dbline{$i} =~ s/\0[^\0]*//; # \^a 4925 delete $dbline{$i} if $dbline{$i} eq ''; 4926 4927 return; 4928} 4929 4930sub _delete_all_actions { 4931 print {$OUT} "Deleting all actions...\n"; 4932 4933 for my $file ( keys %had_breakpoints ) { 4934 local *dbline = $main::{ '_<' . $file }; 4935 $max = $#dbline; 4936 my $was; 4937 for my $i (1 .. $max) { 4938 if ( defined $dbline{$i} ) { 4939 _remove_action_from_dbline($i); 4940 } 4941 } 4942 4943 unless ( $had_breakpoints{$file} &= ~2 ) { 4944 delete $had_breakpoints{$file}; 4945 } 4946 } 4947 4948 return; 4949} 4950 4951sub delete_action { 4952 my $i = shift; 4953 4954 if ( defined($i) ) { 4955 # Can there be one? 4956 die "Line $i has no action .\n" if $dbline[$i] == 0; 4957 4958 # Nuke whatever's there. 4959 _remove_action_from_dbline($i); 4960 } 4961 else { 4962 _delete_all_actions(); 4963 } 4964} 4965 4966=head3 C<cmd_b> (command) 4967 4968Set breakpoints. Since breakpoints can be set in so many places, in so many 4969ways, conditionally or not, the breakpoint code is kind of complex. Mostly, 4970we try to parse the command type, and then shuttle it off to an appropriate 4971subroutine to actually do the work of setting the breakpoint in the right 4972place. 4973 4974=cut 4975 4976sub cmd_b { 4977 my $cmd = shift; 4978 my $line = shift; # [.|line] [cond] 4979 my $dbline = shift; 4980 4981 my $default_cond = sub { 4982 my $cond = shift; 4983 return length($cond) ? $cond : '1'; 4984 }; 4985 4986 # Make . the current line number if it's there.. 4987 $line =~ s/^\.(\s|\z)/$dbline$1/; 4988 4989 # No line number, no condition. Simple break on current line. 4990 if ( $line =~ /^\s*$/ ) { 4991 cmd_b_line( $dbline, 1 ); 4992 } 4993 4994 # Break on load for a file. 4995 elsif ( my ($file) = $line =~ /^load\b\s*(.*)/ ) { 4996 $file =~ s/\s+\z//; 4997 cmd_b_load($file); 4998 } 4999 5000 # b compile|postpone <some sub> [<condition>] 5001 # The interpreter actually traps this one for us; we just put the 5002 # necessary condition in the %postponed hash. 5003 elsif ( my ($action, $subname, $cond) 5004 = $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { 5005 5006 # De-Perl4-ify the name - ' separators to ::. 5007 $subname =~ s/'/::/g; 5008 5009 # Qualify it into the current package unless it's already qualified. 5010 $subname = "${package}::" . $subname unless $subname =~ /::/; 5011 5012 # Add main if it starts with ::. 5013 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 5014 5015 # Save the break type for this sub. 5016 $postponed{$subname} = (($action eq 'postpone') 5017 ? ( "break +0 if " . $default_cond->($cond) ) 5018 : "compile"); 5019 } ## end elsif ($line =~ ... 5020 # b <filename>:<line> [<condition>] 5021 elsif (my ($filename, $line_num, $cond) 5022 = $line =~ /\A(\S+[^:]):(\d+)\s*(.*)/ms) { 5023 cmd_b_filename_line( 5024 $filename, 5025 $line_num, 5026 (length($cond) ? $cond : '1'), 5027 ); 5028 } 5029 # b <sub name> [<condition>] 5030 elsif ( my ($new_subname, $new_cond) = 5031 $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { 5032 5033 # 5034 $subname = $new_subname; 5035 cmd_b_sub( $subname, $default_cond->($new_cond) ); 5036 } 5037 5038 # b <line> [<condition>]. 5039 elsif ( my ($line_n, $cond) = $line =~ /^(\d*)\s*(.*)/ ) { 5040 5041 # Capture the line. If none, it's the current line. 5042 $line = $line_n || $dbline; 5043 5044 # Break on line. 5045 cmd_b_line( $line, $default_cond->($cond) ); 5046 } 5047 5048 # Line didn't make sense. 5049 else { 5050 print "confused by line($line)?\n"; 5051 } 5052 5053 return; 5054} ## end sub cmd_b 5055 5056=head3 C<break_on_load> (API) 5057 5058We want to break when this file is loaded. Mark this file in the 5059C<%break_on_load> hash, and note that it has a breakpoint in 5060C<%had_breakpoints>. 5061 5062=cut 5063 5064sub break_on_load { 5065 my $file = shift; 5066 $break_on_load{$file} = 1; 5067 $had_breakpoints{$file} |= 1; 5068} 5069 5070=head3 C<report_break_on_load> (API) 5071 5072Gives us an array of filenames that are set to break on load. Note that 5073only files with break-on-load are in here, so simply showing the keys 5074suffices. 5075 5076=cut 5077 5078sub report_break_on_load { 5079 sort keys %break_on_load; 5080} 5081 5082=head3 C<cmd_b_load> (command) 5083 5084We take the file passed in and try to find it in C<%INC> (which maps modules 5085to files they came from). We mark those files for break-on-load via 5086C<break_on_load> and then report that it was done. 5087 5088=cut 5089 5090sub cmd_b_load { 5091 my $file = shift; 5092 my @files; 5093 5094 # This is a block because that way we can use a redo inside it 5095 # even without there being any looping structure at all outside it. 5096 { 5097 5098 # Save short name and full path if found. 5099 push @files, $file; 5100 push @files, $::INC{$file} if $::INC{$file}; 5101 5102 # Tack on .pm and do it again unless there was a '.' in the name 5103 # already. 5104 $file .= '.pm', redo unless $file =~ /\./; 5105 } 5106 5107 # Do the real work here. 5108 break_on_load($_) for @files; 5109 5110 # All the files that have break-on-load breakpoints. 5111 @files = report_break_on_load; 5112 5113 # Normalize for the purposes of our printing this. 5114 local $\ = ''; 5115 local $" = ' '; 5116 print $OUT "Will stop on load of '@files'.\n"; 5117} ## end sub cmd_b_load 5118 5119=head3 C<$filename_error> (API package global) 5120 5121Several of the functions we need to implement in the API need to work both 5122on the current file and on other files. We don't want to duplicate code, so 5123C<$filename_error> is used to contain the name of the file that's being 5124worked on (if it's not the current one). 5125 5126We can now build functions in pairs: the basic function works on the current 5127file, and uses C<$filename_error> as part of its error message. Since this is 5128initialized to C<"">, no filename will appear when we are working on the 5129current file. 5130 5131The second function is a wrapper which does the following: 5132 5133=over 4 5134 5135=item * 5136 5137Localizes C<$filename_error> and sets it to the name of the file to be processed. 5138 5139=item * 5140 5141Localizes the C<*dbline> glob and reassigns it to point to the file we want to process. 5142 5143=item * 5144 5145Calls the first function. 5146 5147The first function works on the I<current> file (i.e., the one we changed to), 5148and prints C<$filename_error> in the error message (the name of the other file) 5149if it needs to. When the functions return, C<*dbline> is restored to point 5150to the actual current file (the one we're executing in) and 5151C<$filename_error> is restored to C<"">. This restores everything to 5152the way it was before the second function was called at all. 5153 5154See the comments in L<S<C<sub breakable_line>>|/breakable_line(from, to) (API)> 5155and 5156L<S<C<sub breakable_line_in_filename>>|/breakable_line_in_filename(file, from, to) (API)> 5157for more details. 5158 5159=back 5160 5161=cut 5162 5163use vars qw($filename_error); 5164$filename_error = ''; 5165 5166=head3 breakable_line(from, to) (API) 5167 5168The subroutine decides whether or not a line in the current file is breakable. 5169It walks through C<@dbline> within the range of lines specified, looking for 5170the first line that is breakable. 5171 5172If C<$to> is greater than C<$from>, the search moves forwards, finding the 5173first line I<after> C<$to> that's breakable, if there is one. 5174 5175If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the 5176first line I<before> C<$to> that's breakable, if there is one. 5177 5178=cut 5179 5180sub breakable_line { 5181 5182 my ( $from, $to ) = @_; 5183 5184 # $i is the start point. (Where are the FORTRAN programs of yesteryear?) 5185 my $i = $from; 5186 5187 # If there are at least 2 arguments, we're trying to search a range. 5188 if ( @_ >= 2 ) { 5189 5190 # $delta is positive for a forward search, negative for a backward one. 5191 my $delta = $from < $to ? +1 : -1; 5192 5193 # Keep us from running off the ends of the file. 5194 my $limit = $delta > 0 ? $#dbline : 1; 5195 5196 # Clever test. If you're a mathematician, it's obvious why this 5197 # test works. If not: 5198 # If $delta is positive (going forward), $limit will be $#dbline. 5199 # If $to is less than $limit, ($limit - $to) will be positive, times 5200 # $delta of 1 (positive), so the result is > 0 and we should use $to 5201 # as the stopping point. 5202 # 5203 # If $to is greater than $limit, ($limit - $to) is negative, 5204 # times $delta of 1 (positive), so the result is < 0 and we should 5205 # use $limit ($#dbline) as the stopping point. 5206 # 5207 # If $delta is negative (going backward), $limit will be 1. 5208 # If $to is zero, ($limit - $to) will be 1, times $delta of -1 5209 # (negative) so the result is > 0, and we use $to as the stopping 5210 # point. 5211 # 5212 # If $to is less than zero, ($limit - $to) will be positive, 5213 # times $delta of -1 (negative), so the result is not > 0, and 5214 # we use $limit (1) as the stopping point. 5215 # 5216 # If $to is 1, ($limit - $to) will zero, times $delta of -1 5217 # (negative), still giving zero; the result is not > 0, and 5218 # we use $limit (1) as the stopping point. 5219 # 5220 # if $to is >1, ($limit - $to) will be negative, times $delta of -1 5221 # (negative), giving a positive (>0) value, so we'll set $limit to 5222 # $to. 5223 5224 $limit = $to if ( $limit - $to ) * $delta > 0; 5225 5226 # The real search loop. 5227 # $i starts at $from (the point we want to start searching from). 5228 # We move through @dbline in the appropriate direction (determined 5229 # by $delta: either -1 (back) or +1 (ahead). 5230 # We stay in as long as we haven't hit an executable line 5231 # ($dbline[$i] == 0 means not executable) and we haven't reached 5232 # the limit yet (test similar to the above). 5233 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0; 5234 5235 } ## end if (@_ >= 2) 5236 5237 # If $i points to a line that is executable, return that. 5238 return $i unless $dbline[$i] == 0; 5239 5240 # Format the message and print it: no breakable lines in range. 5241 my ( $pl, $upto ) = ( '', '' ); 5242 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to; 5243 5244 # If there's a filename in filename_error, we'll see it. 5245 # If not, not. 5246 die "Line$pl $from$upto$filename_error not breakable\n"; 5247} ## end sub breakable_line 5248 5249=head3 breakable_line_in_filename(file, from, to) (API) 5250 5251Like C<breakable_line>, but look in another file. 5252 5253=cut 5254 5255sub breakable_line_in_filename { 5256 5257 # Capture the file name. 5258 my ($f) = shift; 5259 5260 # Swap the magic line array over there temporarily. 5261 local *dbline = $main::{ '_<' . $f }; 5262 5263 # If there's an error, it's in this other file. 5264 local $filename_error = " of '$f'"; 5265 5266 # Find the breakable line. 5267 breakable_line(@_); 5268 5269 # *dbline and $filename_error get restored when this block ends. 5270 5271} ## end sub breakable_line_in_filename 5272 5273=head3 break_on_line(lineno, [condition]) (API) 5274 5275Adds a breakpoint with the specified condition (or 1 if no condition was 5276specified) to the specified line. Dies if it can't. 5277 5278=cut 5279 5280sub break_on_line { 5281 my $i = shift; 5282 my $cond = @_ ? shift(@_) : 1; 5283 5284 my $inii = $i; 5285 my $after = ''; 5286 my $pl = ''; 5287 5288 # Woops, not a breakable line. $filename_error allows us to say 5289 # if it was in a different file. 5290 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0; 5291 5292 # Mark this file as having breakpoints in it. 5293 $had_breakpoints{$filename} |= 1; 5294 5295 # If there is an action or condition here already ... 5296 if ( $dbline{$i} ) { 5297 5298 # ... swap this condition for the existing one. 5299 $dbline{$i} =~ s/^[^\0]*/$cond/; 5300 } 5301 else { 5302 5303 # Nothing here - just add the condition. 5304 $dbline{$i} = $cond; 5305 5306 _set_breakpoint_enabled_status($filename, $i, 1); 5307 } 5308 5309 return; 5310} ## end sub break_on_line 5311 5312=head3 cmd_b_line(line, [condition]) (command) 5313 5314Wrapper for C<break_on_line>. Prints the failure message if it 5315doesn't work. 5316 5317=cut 5318 5319sub cmd_b_line { 5320 if (not eval { break_on_line(@_); 1 }) { 5321 local $\ = ''; 5322 print $OUT $@ and return; 5323 } 5324 5325 return; 5326} ## end sub cmd_b_line 5327 5328=head3 cmd_b_filename_line(line, [condition]) (command) 5329 5330Wrapper for C<break_on_filename_line>. Prints the failure message if it 5331doesn't work. 5332 5333=cut 5334 5335sub cmd_b_filename_line { 5336 if (not eval { break_on_filename_line(@_); 1 }) { 5337 local $\ = ''; 5338 print $OUT $@ and return; 5339 } 5340 5341 return; 5342} 5343 5344=head3 break_on_filename_line(file, line, [condition]) (API) 5345 5346Switches to the file specified and then calls C<break_on_line> to set 5347the breakpoint. 5348 5349=cut 5350 5351sub break_on_filename_line { 5352 my $f = shift; 5353 my $i = shift; 5354 my $cond = @_ ? shift(@_) : 1; 5355 5356 # Switch the magical hash temporarily. 5357 local *dbline = $main::{ '_<' . $f }; 5358 5359 # Localize the variables that break_on_line uses to make its message. 5360 local $filename_error = " of '$f'"; 5361 local $filename = $f; 5362 5363 # Add the breakpoint. 5364 break_on_line( $i, $cond ); 5365 5366 return; 5367} ## end sub break_on_filename_line 5368 5369=head3 break_on_filename_line_range(file, from, to, [condition]) (API) 5370 5371Switch to another file, search the range of lines specified for an 5372executable one, and put a breakpoint on the first one you find. 5373 5374=cut 5375 5376sub break_on_filename_line_range { 5377 my $f = shift; 5378 my $from = shift; 5379 my $to = shift; 5380 my $cond = @_ ? shift(@_) : 1; 5381 5382 # Find a breakable line if there is one. 5383 my $i = breakable_line_in_filename( $f, $from, $to ); 5384 5385 # Add the breakpoint. 5386 break_on_filename_line( $f, $i, $cond ); 5387 5388 return; 5389} ## end sub break_on_filename_line_range 5390 5391=head3 subroutine_filename_lines(subname, [condition]) (API) 5392 5393Search for a subroutine within a given file. The condition is ignored. 5394Uses C<find_sub> to locate the desired subroutine. 5395 5396=cut 5397 5398sub subroutine_filename_lines { 5399 my ( $subname ) = @_; 5400 5401 # Returned value from find_sub() is fullpathname:startline-endline. 5402 # The match creates the list (fullpathname, start, end). 5403 return (find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/); 5404} ## end sub subroutine_filename_lines 5405 5406=head3 break_subroutine(subname) (API) 5407 5408Places a break on the first line possible in the specified subroutine. Uses 5409C<subroutine_filename_lines> to find the subroutine, and 5410C<break_on_filename_line_range> to place the break. 5411 5412=cut 5413 5414sub break_subroutine { 5415 my $subname = shift; 5416 5417 # Get filename, start, and end. 5418 my ( $file, $s, $e ) = subroutine_filename_lines($subname) 5419 or die "Subroutine $subname not found.\n"; 5420 5421 5422 # Null condition changes to '1' (always true). 5423 my $cond = @_ ? shift(@_) : 1; 5424 5425 # Put a break the first place possible in the range of lines 5426 # that make up this subroutine. 5427 break_on_filename_line_range( $file, $s, $e, $cond ); 5428 5429 return; 5430} ## end sub break_subroutine 5431 5432=head3 cmd_b_sub(subname, [condition]) (command) 5433 5434We take the incoming subroutine name and fully-qualify it as best we can. 5435 5436=over 4 5437 5438=item 1. If it's already fully-qualified, leave it alone. 5439 5440=item 2. Try putting it in the current package. 5441 5442=item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there. 5443 5444=item 4. If it starts with '::', put it in 'main::'. 5445 5446=back 5447 5448After all this cleanup, we call C<break_subroutine> to try to set the 5449breakpoint. 5450 5451=cut 5452 5453sub cmd_b_sub { 5454 my $subname = shift; 5455 my $cond = @_ ? shift : 1; 5456 5457 # If the subname isn't a code reference, qualify it so that 5458 # break_subroutine() will work right. 5459 if ( ref($subname) ne 'CODE' ) { 5460 5461 # Not Perl 4. 5462 $subname =~ s/'/::/g; 5463 my $s = $subname; 5464 5465 # Put it in this package unless it's already qualified. 5466 if ($subname !~ /::/) 5467 { 5468 $subname = $package . '::' . $subname; 5469 }; 5470 5471 # Requalify it into CORE::GLOBAL if qualifying it into this 5472 # package resulted in its not being defined, but only do so 5473 # if it really is in CORE::GLOBAL. 5474 my $core_name = "CORE::GLOBAL::$s"; 5475 if ((!defined(&$subname)) 5476 and ($s !~ /::/) 5477 and (defined &{$core_name})) 5478 { 5479 $subname = $core_name; 5480 } 5481 5482 # Put it in package 'main' if it has a leading ::. 5483 if ($subname =~ /\A::/) 5484 { 5485 $subname = "main" . $subname; 5486 } 5487 } ## end if ( ref($subname) ne 'CODE' ) { 5488 5489 # Try to set the breakpoint. 5490 if (not eval { break_subroutine( $subname, $cond ); 1 }) { 5491 local $\ = ''; 5492 print {$OUT} $@; 5493 return; 5494 } 5495 5496 return; 5497} ## end sub cmd_b_sub 5498 5499=head3 C<cmd_B> - delete breakpoint(s) (command) 5500 5501The command mostly parses the command line and tries to turn the argument 5502into a line spec. If it can't, it uses the current line. It then calls 5503C<delete_breakpoint> to actually do the work. 5504 5505If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments, 5506thereby deleting all the breakpoints. 5507 5508=cut 5509 5510sub cmd_B { 5511 my $cmd = shift; 5512 5513 # No line spec? Use dbline. 5514 # If there is one, use it if it's non-zero, or wipe it out if it is. 5515 my $line = ( $_[0] =~ /\A\./ ) ? $dbline : (shift || ''); 5516 my $dbline = shift; 5517 5518 # If the line was dot, make the line the current one. 5519 $line =~ s/^\./$dbline/; 5520 5521 # If it's * we're deleting all the breakpoints. 5522 if ( $line eq '*' ) { 5523 if (not eval { delete_breakpoint(); 1 }) { 5524 print {$OUT} $@; 5525 } 5526 } 5527 5528 # If there is a line spec, delete the breakpoint on that line. 5529 elsif ( $line =~ /\A(\S.*)/ ) { 5530 if (not eval { delete_breakpoint( $line || $dbline ); 1 }) { 5531 local $\ = ''; 5532 print {$OUT} $@; 5533 } 5534 } ## end elsif ($line =~ /^(\S.*)/) 5535 5536 # No line spec. 5537 else { 5538 print {$OUT} 5539 "Deleting a breakpoint requires a line number, or '*' for all\n" 5540 ; # hint 5541 } 5542 5543 return; 5544} ## end sub cmd_B 5545 5546=head3 delete_breakpoint([line]) (API) 5547 5548This actually does the work of deleting either a single breakpoint, or all 5549of them. 5550 5551For a single line, we look for it in C<@dbline>. If it's nonbreakable, we 5552just drop out with a message saying so. If it is, we remove the condition 5553part of the 'condition\0action' that says there's a breakpoint here. If, 5554after we've done that, there's nothing left, we delete the corresponding 5555line in C<%dbline> to signal that no action needs to be taken for this line. 5556 5557For all breakpoints, we iterate through the keys of C<%had_breakpoints>, 5558which lists all currently-loaded files which have breakpoints. We then look 5559at each line in each of these files, temporarily switching the C<%dbline> 5560and C<@dbline> structures to point to the files in question, and do what 5561we did in the single line case: delete the condition in C<@dbline>, and 5562delete the key in C<%dbline> if nothing's left. 5563 5564We then wholesale delete C<%postponed>, C<%postponed_file>, and 5565C<%break_on_load>, because these structures contain breakpoints for files 5566and code that haven't been loaded yet. We can just kill these off because there 5567are no magical debugger structures associated with them. 5568 5569=cut 5570 5571sub _remove_breakpoint_entry { 5572 my ($fn, $i) = @_; 5573 5574 delete $dbline{$i}; 5575 _delete_breakpoint_data_ref($fn, $i); 5576 5577 return; 5578} 5579 5580sub _delete_all_breakpoints { 5581 print {$OUT} "Deleting all breakpoints...\n"; 5582 5583 # %had_breakpoints lists every file that had at least one 5584 # breakpoint in it. 5585 for my $fn ( keys %had_breakpoints ) { 5586 5587 # Switch to the desired file temporarily. 5588 local *dbline = $main::{ '_<' . $fn }; 5589 5590 $max = $#dbline; 5591 5592 # For all lines in this file ... 5593 for my $i (1 .. $max) { 5594 5595 # If there's a breakpoint or action on this line ... 5596 if ( defined $dbline{$i} ) { 5597 5598 # ... remove the breakpoint. 5599 $dbline{$i} =~ s/\A[^\0]+//; 5600 if ( $dbline{$i} =~ s/\A\0?\z// ) { 5601 # Remove the entry altogether if no action is there. 5602 _remove_breakpoint_entry($fn, $i); 5603 } 5604 } ## end if (defined $dbline{$i... 5605 } ## end for $i (1 .. $max) 5606 5607 # If, after we turn off the "there were breakpoints in this file" 5608 # bit, the entry in %had_breakpoints for this file is zero, 5609 # we should remove this file from the hash. 5610 if ( not $had_breakpoints{$fn} &= (~1) ) { 5611 delete $had_breakpoints{$fn}; 5612 } 5613 } ## end for my $fn (keys %had_breakpoints) 5614 5615 # Kill off all the other breakpoints that are waiting for files that 5616 # haven't been loaded yet. 5617 undef %postponed; 5618 undef %postponed_file; 5619 undef %break_on_load; 5620 5621 return; 5622} 5623 5624sub _delete_breakpoint_from_line { 5625 my ($i) = @_; 5626 5627 # Woops. This line wasn't breakable at all. 5628 die "Line $i not breakable.\n" if $dbline[$i] == 0; 5629 5630 # Kill the condition, but leave any action. 5631 $dbline{$i} =~ s/\A[^\0]*//; 5632 5633 # Remove the entry entirely if there's no action left. 5634 if ($dbline{$i} eq '') { 5635 _remove_breakpoint_entry($filename, $i); 5636 } 5637 5638 return; 5639} 5640 5641sub delete_breakpoint { 5642 my $i = shift; 5643 5644 # If we got a line, delete just that one. 5645 if ( defined($i) ) { 5646 _delete_breakpoint_from_line($i); 5647 } 5648 # No line; delete them all. 5649 else { 5650 _delete_all_breakpoints(); 5651 } 5652 5653 return; 5654} 5655 5656=head3 cmd_stop (command) 5657 5658This is meant to be part of the new command API, but it isn't called or used 5659anywhere else in the debugger. XXX It is probably meant for use in development 5660of new commands. 5661 5662=cut 5663 5664sub cmd_stop { # As on ^C, but not signal-safy. 5665 $signal = 1; 5666} 5667 5668=head3 C<cmd_e> - threads 5669 5670Display the current thread id: 5671 5672 e 5673 5674This could be how (when implemented) to send commands to this thread id (e cmd) 5675or that thread id (e tid cmd). 5676 5677=cut 5678 5679sub cmd_e { 5680 my $cmd = shift; 5681 my $line = shift; 5682 unless (exists($INC{'threads.pm'})) { 5683 print "threads not loaded($ENV{PERL5DB_THREADED}) 5684 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 5685 } else { 5686 my $tid = threads->tid; 5687 print "thread id: $tid\n"; 5688 } 5689} ## end sub cmd_e 5690 5691=head3 C<cmd_E> - list of thread ids 5692 5693Display the list of available thread ids: 5694 5695 E 5696 5697This could be used (when implemented) to send commands to all threads (E cmd). 5698 5699=cut 5700 5701sub cmd_E { 5702 my $cmd = shift; 5703 my $line = shift; 5704 unless (exists($INC{'threads.pm'})) { 5705 print "threads not loaded($ENV{PERL5DB_THREADED}) 5706 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 5707 } else { 5708 my $tid = threads->tid; 5709 print "thread ids: ".join(', ', 5710 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list 5711 )."\n"; 5712 } 5713} ## end sub cmd_E 5714 5715=head3 C<cmd_h> - help command (command) 5716 5717Does the work of either 5718 5719=over 4 5720 5721=item * 5722 5723Showing all the debugger help 5724 5725=item * 5726 5727Showing help for a specific command 5728 5729=back 5730 5731=cut 5732 5733use vars qw($help); 5734use vars qw($summary); 5735 5736sub cmd_h { 5737 my $cmd = shift; 5738 5739 # If we have no operand, assume null. 5740 my $line = shift || ''; 5741 5742 # 'h h'. Print the long-format help. 5743 if ( $line =~ /\Ah\s*\z/ ) { 5744 print_help($help); 5745 } 5746 5747 # 'h <something>'. Search for the command and print only its help. 5748 elsif ( my ($asked) = $line =~ /\A(\S.*)\z/ ) { 5749 5750 # support long commands; otherwise bogus errors 5751 # happen when you ask for h on <CR> for example 5752 my $qasked = quotemeta($asked); # for searching; we don't 5753 # want to use it as a pattern. 5754 # XXX: finds CR but not <CR> 5755 5756 # Search the help string for the command. 5757 if ( 5758 $help =~ /^ # Start of a line 5759 <? # Optional '<' 5760 (?:[IB]<) # Optional markup 5761 $qasked # The requested command 5762 /mx 5763 ) 5764 { 5765 5766 # It's there; pull it out and print it. 5767 while ( 5768 $help =~ /^ 5769 (<? # Optional '<' 5770 (?:[IB]<) # Optional markup 5771 $qasked # The command 5772 ([\s\S]*?) # Description line(s) 5773 \n) # End of last description line 5774 (?!\s) # Next line not starting with 5775 # whitespace 5776 /mgx 5777 ) 5778 { 5779 print_help($1); 5780 } 5781 } 5782 5783 # Not found; not a debugger command. 5784 else { 5785 print_help("B<$asked> is not a debugger command.\n"); 5786 } 5787 } ## end elsif ($line =~ /^(\S.*)$/) 5788 5789 # 'h' - print the summary help. 5790 else { 5791 print_help($summary); 5792 } 5793} ## end sub cmd_h 5794 5795=head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command) 5796 5797To list breakpoints, the command has to look determine where all of them are 5798first. It starts a C<%had_breakpoints>, which tells us what all files have 5799breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the 5800magic source and breakpoint data structures) to the file, and then look 5801through C<%dbline> for lines with breakpoints and/or actions, listing them 5802out. We look through C<%postponed> not-yet-compiled subroutines that have 5803breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files 5804that have breakpoints. 5805 5806Watchpoints are simpler: we just list the entries in C<@to_watch>. 5807 5808=cut 5809 5810sub _cmd_L_calc_arg { 5811 # If no argument, list everything. Pre-5.8.0 version always lists 5812 # everything 5813 my $arg = shift || 'abw'; 5814 if ($CommandSet ne '580') 5815 { 5816 $arg = 'abw'; 5817 } 5818 5819 return $arg; 5820} 5821 5822sub _cmd_L_calc_wanted_flags { 5823 my $arg = _cmd_L_calc_arg(shift); 5824 5825 return (map { index($arg, $_) >= 0 ? 1 : 0 } qw(a b w)); 5826} 5827 5828 5829sub _cmd_L_handle_breakpoints { 5830 my ($handle_db_line) = @_; 5831 5832 BREAKPOINTS_SCAN: 5833 # Look in all the files with breakpoints... 5834 for my $file ( keys %had_breakpoints ) { 5835 5836 # Temporary switch to this file. 5837 local *dbline = $main::{ '_<' . $file }; 5838 5839 # Set up to look through the whole file. 5840 $max = $#dbline; 5841 my $was; # Flag: did we print something 5842 # in this file? 5843 5844 # For each line in the file ... 5845 for my $i (1 .. $max) { 5846 5847 # We've got something on this line. 5848 if ( defined $dbline{$i} ) { 5849 5850 # Print the header if we haven't. 5851 if (not $was++) { 5852 print {$OUT} "$file:\n"; 5853 } 5854 5855 # Print the line. 5856 print {$OUT} " $i:\t", $dbline[$i]; 5857 5858 $handle_db_line->($dbline{$i}); 5859 5860 # Quit if the user hit interrupt. 5861 if ($signal) { 5862 last BREAKPOINTS_SCAN; 5863 } 5864 } ## end if (defined $dbline{$i... 5865 } ## end for my $i (1 .. $max) 5866 } ## end for my $file (keys %had_breakpoints) 5867 5868 return; 5869} 5870 5871sub _cmd_L_handle_postponed_breakpoints { 5872 my ($handle_db_line) = @_; 5873 5874 print {$OUT} "Postponed breakpoints in files:\n"; 5875 5876 POSTPONED_SCANS: 5877 for my $file ( keys %postponed_file ) { 5878 my $db = $postponed_file{$file}; 5879 print {$OUT} " $file:\n"; 5880 for my $line ( sort { $a <=> $b } keys %$db ) { 5881 print {$OUT} " $line:\n"; 5882 5883 $handle_db_line->($db->{$line}); 5884 5885 if ($signal) { 5886 last POSTPONED_SCANS; 5887 } 5888 } 5889 if ($signal) { 5890 last POSTPONED_SCANS; 5891 } 5892 } 5893 5894 return; 5895} 5896 5897 5898sub cmd_L { 5899 my $cmd = shift; 5900 5901 my ($action_wanted, $break_wanted, $watch_wanted) = 5902 _cmd_L_calc_wanted_flags(shift); 5903 5904 my $handle_db_line = sub { 5905 my ($l) = @_; 5906 5907 my ( $stop, $action ) = split( /\0/, $l ); 5908 5909 if ($stop and $break_wanted) { 5910 print {$OUT} " break if (", $stop, ")\n" 5911 } 5912 5913 if ($action && $action_wanted) { 5914 print {$OUT} " action: ", $action, "\n" 5915 } 5916 5917 return; 5918 }; 5919 5920 # Breaks and actions are found together, so we look in the same place 5921 # for both. 5922 if ( $break_wanted or $action_wanted ) { 5923 _cmd_L_handle_breakpoints($handle_db_line); 5924 } 5925 5926 # Look for breaks in not-yet-compiled subs: 5927 if ( %postponed and $break_wanted ) { 5928 print {$OUT} "Postponed breakpoints in subroutines:\n"; 5929 my $subname; 5930 SUBS_SCAN: 5931 for $subname ( keys %postponed ) { 5932 print {$OUT} " $subname\t$postponed{$subname}\n"; 5933 if ($signal) { 5934 last SUBS_SCAN; 5935 } 5936 } 5937 } ## end if (%postponed and $break_wanted) 5938 5939 # Find files that have not-yet-loaded breaks: 5940 my @have = map { # Combined keys 5941 keys %{ $postponed_file{$_} } 5942 } keys %postponed_file; 5943 5944 # If there are any, list them. 5945 if ( @have and ( $break_wanted or $action_wanted ) ) { 5946 _cmd_L_handle_postponed_breakpoints($handle_db_line); 5947 } ## end if (@have and ($break_wanted... 5948 5949 if ( %break_on_load and $break_wanted ) { 5950 print {$OUT} "Breakpoints on load:\n"; 5951 BREAK_ON_LOAD: for my $filename ( keys %break_on_load ) { 5952 print {$OUT} " $filename\n"; 5953 last BREAK_ON_LOAD if $signal; 5954 } 5955 } ## end if (%break_on_load and... 5956 5957 if ($watch_wanted and ( $trace & 2 )) { 5958 print {$OUT} "Watch-expressions:\n" if @to_watch; 5959 TO_WATCH: for my $expr (@to_watch) { 5960 print {$OUT} " $expr\n"; 5961 last TO_WATCH if $signal; 5962 } 5963 } 5964 5965 return; 5966} ## end sub cmd_L 5967 5968=head3 C<cmd_M> - list modules (command) 5969 5970Just call C<list_modules>. 5971 5972=cut 5973 5974sub cmd_M { 5975 list_modules(); 5976 5977 return; 5978} 5979 5980=head3 C<cmd_o> - options (command) 5981 5982If this is just C<o> by itself, we list the current settings via 5983C<dump_option>. If there's a nonblank value following it, we pass that on to 5984C<parse_options> for processing. 5985 5986=cut 5987 5988sub cmd_o { 5989 my $cmd = shift; 5990 my $opt = shift || ''; # opt[=val] 5991 5992 # Nonblank. Try to parse and process. 5993 if ( $opt =~ /^(\S.*)/ ) { 5994 parse_options($1); 5995 } 5996 5997 # Blank. List the current option settings. 5998 else { 5999 for (@options) { 6000 dump_option($_); 6001 } 6002 } 6003} ## end sub cmd_o 6004 6005=head3 C<cmd_O> - nonexistent in 5.8.x (command) 6006 6007Advises the user that the O command has been renamed. 6008 6009=cut 6010 6011sub cmd_O { 6012 print $OUT "The old O command is now the o command.\n"; # hint 6013 print $OUT "Use 'h' to get current command help synopsis or\n"; # 6014 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; # 6015} 6016 6017=head3 C<cmd_v> - view window (command) 6018 6019Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to 6020move back a few lines to list the selected line in context. Uses C<_cmd_l_main> 6021to do the actual listing after figuring out the range of line to request. 6022 6023=cut 6024 6025use vars qw($preview); 6026 6027sub cmd_v { 6028 my $cmd = shift; 6029 my $line = shift; 6030 6031 # Extract the line to list around. (Astute readers will have noted that 6032 # this pattern will match whether or not a numeric line is specified, 6033 # which means that we'll always enter this loop (though a non-numeric 6034 # argument results in no action at all)). 6035 if ( $line =~ /^(\d*)$/ ) { 6036 6037 # Total number of lines to list (a windowful). 6038 $incr = $window - 1; 6039 6040 # Set the start to the argument given (if there was one). 6041 $start = $1 if $1; 6042 6043 # Back up by the context amount. Don't back up past line 1. 6044 $start -= $preview; 6045 $start = 1 unless $start > 0; 6046 6047 # Put together a linespec that _cmd_l_main will like. 6048 $line = $start . '-' . ( $start + $incr ); 6049 6050 # List the lines. 6051 _cmd_l_main( $line ); 6052 } ## end if ($line =~ /^(\d*)$/) 6053} ## end sub cmd_v 6054 6055=head3 C<cmd_w> - add a watch expression (command) 6056 6057The 5.8 version of this command adds a watch expression if one is specified; 6058it does nothing if entered with no operands. 6059 6060We extract the expression, save it, evaluate it in the user's context, and 6061save the value. We'll re-evaluate it each time the debugger passes a line, 6062and will stop (see the code at the top of the command loop) if the value 6063of any of the expressions changes. 6064 6065=cut 6066 6067sub _add_watch_expr { 6068 my $expr = shift; 6069 6070 # ... save it. 6071 push @to_watch, $expr; 6072 6073 # Parameterize DB::eval and call it to get the expression's value 6074 # in the user's context. This version can handle expressions which 6075 # return a list value. 6076 $evalarg = $expr; 6077 # The &-call is here to ascertain the mutability of @_. 6078 my ($val) = join( ' ', &DB::eval); 6079 $val = ( defined $val ) ? "'$val'" : 'undef'; 6080 6081 # Save the current value of the expression. 6082 push @old_watch, $val; 6083 6084 # We are now watching expressions. 6085 $trace |= 2; 6086 6087 return; 6088} 6089 6090sub cmd_w { 6091 my $cmd = shift; 6092 6093 # Null expression if no arguments. 6094 my $expr = shift || ''; 6095 6096 # If expression is not null ... 6097 if ( $expr =~ /\A\S/ ) { 6098 _add_watch_expr($expr); 6099 } ## end if ($expr =~ /^(\S.*)/) 6100 6101 # You have to give one to get one. 6102 else { 6103 print $OUT "Adding a watch-expression requires an expression\n"; # hint 6104 } 6105 6106 return; 6107} 6108 6109=head3 C<cmd_W> - delete watch expressions (command) 6110 6111This command accepts either a watch expression to be removed from the list 6112of watch expressions, or C<*> to delete them all. 6113 6114If C<*> is specified, we simply empty the watch expression list and the 6115watch expression value list. We also turn off the bit that says we've got 6116watch expressions. 6117 6118If an expression (or partial expression) is specified, we pattern-match 6119through the expressions and remove the ones that match. We also discard 6120the corresponding values. If no watch expressions are left, we turn off 6121the I<watching expressions> bit. 6122 6123=cut 6124 6125sub cmd_W { 6126 my $cmd = shift; 6127 my $expr = shift || ''; 6128 6129 # Delete them all. 6130 if ( $expr eq '*' ) { 6131 6132 # Not watching now. 6133 $trace &= ~2; 6134 6135 print $OUT "Deleting all watch expressions ...\n"; 6136 6137 # And all gone. 6138 @to_watch = @old_watch = (); 6139 } 6140 6141 # Delete one of them. 6142 elsif ( $expr =~ /^(\S.*)/ ) { 6143 6144 # Where we are in the list. 6145 my $i_cnt = 0; 6146 6147 # For each expression ... 6148 foreach (@to_watch) { 6149 my $val = $to_watch[$i_cnt]; 6150 6151 # Does this one match the command argument? 6152 if ( $val eq $expr ) { # =~ m/^\Q$i$/) { 6153 # Yes. Turn it off, and its value too. 6154 splice( @to_watch, $i_cnt, 1 ); 6155 splice( @old_watch, $i_cnt, 1 ); 6156 } 6157 $i_cnt++; 6158 } ## end foreach (@to_watch) 6159 6160 # We don't bother to turn watching off because 6161 # a) we don't want to stop calling watchfunction() if it exists 6162 # b) foreach over a null list doesn't do anything anyway 6163 6164 } ## end elsif ($expr =~ /^(\S.*)/) 6165 6166 # No command arguments entered. 6167 else { 6168 print $OUT 6169 "Deleting a watch-expression requires an expression, or '*' for all\n" 6170 ; # hint 6171 } 6172} ## end sub cmd_W 6173 6174### END of the API section 6175 6176=head1 SUPPORT ROUTINES 6177 6178These are general support routines that are used in a number of places 6179throughout the debugger. 6180 6181=head2 save 6182 6183save() saves the user's versions of globals that would mess us up in C<@saved>, 6184and installs the versions we like better. 6185 6186=cut 6187 6188sub save { 6189 6190 # Save eval failure, command failure, extended OS error, output field 6191 # separator, input record separator, output record separator and 6192 # the warning setting. 6193 @saved = ( $@, $!, $^E, $,, $/, $\, $^W ); 6194 6195 $, = ""; # output field separator is null string 6196 $/ = "\n"; # input record separator is newline 6197 $\ = ""; # output record separator is null string 6198 $^W = 0; # warnings are off 6199} ## end sub save 6200 6201=head2 C<print_lineinfo> - show where we are now 6202 6203print_lineinfo prints whatever it is that it is handed; it prints it to the 6204C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows 6205us to feed line information to a client editor without messing up the 6206debugger output. 6207 6208=cut 6209 6210sub print_lineinfo { 6211 6212 # Make the terminal sensible if we're not the primary debugger. 6213 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$; 6214 local $\ = ''; 6215 local $, = ''; 6216 # $LINEINFO may be undef if $noTTY is set or some other issue. 6217 if ($LINEINFO) 6218 { 6219 print {$LINEINFO} @_; 6220 } 6221} ## end sub print_lineinfo 6222 6223=head2 C<postponed_sub> 6224 6225Handles setting postponed breakpoints in subroutines once they're compiled. 6226For breakpoints, we use C<DB::find_sub> to locate the source file and line 6227range for the subroutine, then mark the file as having a breakpoint, 6228temporarily switch the C<*dbline> glob over to the source file, and then 6229search the given range of lines to find a breakable line. If we find one, 6230we set the breakpoint on it, deleting the breakpoint from C<%postponed>. 6231 6232=cut 6233 6234# The following takes its argument via $evalarg to preserve current @_ 6235 6236sub postponed_sub { 6237 6238 # Get the subroutine name. 6239 my $subname = shift; 6240 6241 # If this is a 'break +<n> if <condition>' ... 6242 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) { 6243 6244 # If there's no offset, use '+0'. 6245 my $offset = $1 || 0; 6246 6247 # find_sub's value is 'fullpath-filename:start-stop'. It's 6248 # possible that the filename might have colons in it too. 6249 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ ); 6250 if ($i) { 6251 6252 # We got the start line. Add the offset '+<n>' from 6253 # $postponed{subname}. 6254 $i += $offset; 6255 6256 # Switch to the file this sub is in, temporarily. 6257 local *dbline = $main::{ '_<' . $file }; 6258 6259 # No warnings, please. 6260 local $^W = 0; # != 0 is magical below 6261 6262 # This file's got a breakpoint in it. 6263 $had_breakpoints{$file} |= 1; 6264 6265 # Last line in file. 6266 $max = $#dbline; 6267 6268 # Search forward until we hit a breakable line or get to 6269 # the end of the file. 6270 ++$i until $dbline[$i] != 0 or $i >= $max; 6271 6272 # Copy the breakpoint in and delete it from %postponed. 6273 $dbline{$i} = delete $postponed{$subname}; 6274 } ## end if ($i) 6275 6276 # find_sub didn't find the sub. 6277 else { 6278 local $\ = ''; 6279 print $OUT "Subroutine $subname not found.\n"; 6280 } 6281 return; 6282 } ## end if ($postponed{$subname... 6283 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 } 6284 6285 #print $OUT "In postponed_sub for '$subname'.\n"; 6286} ## end sub postponed_sub 6287 6288=head2 C<postponed> 6289 6290Called after each required file is compiled, but before it is executed; 6291also called if the name of a just-compiled subroutine is a key of 6292C<%postponed>. Propagates saved breakpoints (from S<C<b compile>>, 6293S<C<b load>>, etc.) into the just-compiled code. 6294 6295If this is a C<require>'d file, the incoming parameter is the glob 6296C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file. 6297 6298If it's a subroutine, the incoming parameter is the subroutine name. 6299 6300=cut 6301 6302sub postponed { 6303 6304 # If there's a break, process it. 6305 if ($ImmediateStop) { 6306 6307 # Right, we've stopped. Turn it off. 6308 $ImmediateStop = 0; 6309 6310 # Enter the command loop when DB::DB gets called. 6311 $signal = 1; 6312 } 6313 6314 # If this is a subroutine, let postponed_sub() deal with it. 6315 if (ref(\$_[0]) ne 'GLOB') { 6316 return postponed_sub(@_); 6317 } 6318 6319 # Not a subroutine. Deal with the file. 6320 local *dbline = shift; 6321 my $filename = $dbline; 6322 $filename =~ s/^_<//; 6323 local $\ = ''; 6324 $signal = 1, print $OUT "'$filename' loaded...\n" 6325 if $break_on_load{$filename}; 6326 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame; 6327 6328 # Do we have any breakpoints to put in this file? 6329 return unless $postponed_file{$filename}; 6330 6331 # Yes. Mark this file as having breakpoints. 6332 $had_breakpoints{$filename} |= 1; 6333 6334 # "Cannot be done: insufficient magic" - we can't just put the 6335 # breakpoints saved in %postponed_file into %dbline by assigning 6336 # the whole hash; we have to do it one item at a time for the 6337 # breakpoints to be set properly. 6338 #%dbline = %{$postponed_file{$filename}}; 6339 6340 # Set the breakpoints, one at a time. 6341 my $key; 6342 6343 for $key ( keys %{ $postponed_file{$filename} } ) { 6344 6345 # Stash the saved breakpoint into the current file's magic line array. 6346 $dbline{$key} = ${ $postponed_file{$filename} }{$key}; 6347 } 6348 6349 # This file's been compiled; discard the stored breakpoints. 6350 delete $postponed_file{$filename}; 6351 6352} ## end sub postponed 6353 6354=head2 C<dumpit> 6355 6356C<dumpit> is the debugger's wrapper around dumpvar.pl. 6357 6358It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and 6359a reference to a variable (the thing to be dumped) as its input. 6360 6361The incoming filehandle is selected for output (C<dumpvar.pl> is printing to 6362the currently-selected filehandle, thank you very much). The current 6363values of the package globals C<$single> and C<$trace> are backed up in 6364lexicals, and they are turned off (this keeps the debugger from trying 6365to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to 6366preserve its current value and it is set to zero to prevent entry/exit 6367messages from printing, and C<$doret> is localized as well and set to -2 to 6368prevent return values from being shown. 6369 6370C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and 6371tries to load it (note: if you have a C<dumpvar.pl> ahead of the 6372installed version in C<@INC>, yours will be used instead. Possible security 6373problem?). 6374 6375It then checks to see if the subroutine C<main::dumpValue> is now defined 6376it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()> 6377localizes the globals necessary for things to be sane when C<main::dumpValue()> 6378is called, and picks up the variable to be dumped from the parameter list. 6379 6380It checks the package global C<%options> to see if there's a C<dumpDepth> 6381specified. If not, -1 is assumed; if so, the supplied value gets passed on to 6382C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a 6383structure: -1 means dump everything. 6384 6385C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a 6386warning. 6387 6388In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored 6389and we then return to the caller. 6390 6391=cut 6392 6393sub dumpit { 6394 6395 # Save the current output filehandle and switch to the one 6396 # passed in as the first parameter. 6397 my $savout = select(shift); 6398 6399 # Save current settings of $single and $trace, and then turn them off. 6400 my $osingle = $single; 6401 my $otrace = $trace; 6402 $single = $trace = 0; 6403 6404 # XXX Okay, what do $frame and $doret do, again? 6405 local $frame = 0; 6406 local $doret = -2; 6407 6408 # Load dumpvar.pl unless we've already got the sub we need from it. 6409 unless ( defined &main::dumpValue ) { 6410 do 'dumpvar.pl' or die $@; 6411 } 6412 6413 # If the load succeeded (or we already had dumpvalue()), go ahead 6414 # and dump things. 6415 if ( defined &main::dumpValue ) { 6416 local $\ = ''; 6417 local $, = ''; 6418 local $" = ' '; 6419 my $v = shift; 6420 my $maxdepth = shift || $option{dumpDepth}; 6421 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth 6422 main::dumpValue( $v, $maxdepth ); 6423 } ## end if (defined &main::dumpValue) 6424 6425 # Oops, couldn't load dumpvar.pl. 6426 else { 6427 local $\ = ''; 6428 print $OUT "dumpvar.pl not available.\n"; 6429 } 6430 6431 # Reset $single and $trace to their old values. 6432 $single = $osingle; 6433 $trace = $otrace; 6434 6435 # Restore the old filehandle. 6436 select($savout); 6437} ## end sub dumpit 6438 6439=head2 C<print_trace> 6440 6441C<print_trace>'s job is to print a stack trace. It does this via the 6442C<dump_trace> routine, which actually does all the ferreting-out of the 6443stack trace data. C<print_trace> takes care of formatting it nicely and 6444printing it to the proper filehandle. 6445 6446Parameters: 6447 6448=over 4 6449 6450=item * 6451 6452The filehandle to print to. 6453 6454=item * 6455 6456How many frames to skip before starting trace. 6457 6458=item * 6459 6460How many frames to print. 6461 6462=item * 6463 6464A flag: if true, print a I<short> trace without filenames, line numbers, or arguments 6465 6466=back 6467 6468The original comment below seems to be noting that the traceback may not be 6469correct if this routine is called in a tied method. 6470 6471=cut 6472 6473# Tied method do not create a context, so may get wrong message: 6474 6475sub print_trace { 6476 local $\ = ''; 6477 my $fh = shift; 6478 6479 # If this is going to a client editor, but we're not the primary 6480 # debugger, reset it first. 6481 resetterm(1) 6482 if $fh eq $LINEINFO # client editor 6483 and $LINEINFO eq $OUT # normal output 6484 and $term_pid != $$; # not the primary 6485 6486 # Collect the actual trace information to be formatted. 6487 # This is an array of hashes of subroutine call info. 6488 my @sub = dump_trace( $_[0] + 1, $_[1] ); 6489 6490 # Grab the "short report" flag from @_. 6491 my $short = $_[2]; # Print short report, next one for sub name 6492 6493 # Run through the traceback info, format it, and print it. 6494 my $s; 6495 for my $i (0 .. $#sub) { 6496 6497 # Drop out if the user has lost interest and hit control-C. 6498 last if $signal; 6499 6500 # Set the separator so arrays print nice. 6501 local $" = ', '; 6502 6503 # Grab and stringify the arguments if they are there. 6504 my $args = 6505 defined $sub[$i]{args} 6506 ? "(@{ $sub[$i]{args} })" 6507 : ''; 6508 6509 # Shorten them up if $maxtrace says they're too long. 6510 $args = ( substr $args, 0, $maxtrace - 3 ) . '...' 6511 if length $args > $maxtrace; 6512 6513 # Get the file name. 6514 my $file = $sub[$i]{file}; 6515 6516 # Put in a filename header if short is off. 6517 $file = $file eq '-e' ? $file : "file '$file'" unless $short; 6518 6519 # Get the actual sub's name, and shorten to $maxtrace's requirement. 6520 $s = $sub[$i]{'sub'}; 6521 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace; 6522 6523 # Short report uses trimmed file and sub names. 6524 if ($short) { 6525 my $sub = @_ >= 4 ? $_[3] : $s; 6526 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n"; 6527 } ## end if ($short) 6528 6529 # Non-short report includes full names. 6530 else { 6531 print $fh "$sub[$i]{context} = $s$args" 6532 . " called from $file" 6533 . " line $sub[$i]{line}\n"; 6534 } 6535 } ## end for my $i (0 .. $#sub) 6536} ## end sub print_trace 6537 6538=head2 dump_trace(skip[,count]) 6539 6540Actually collect the traceback information available via C<caller()>. It does 6541some filtering and cleanup of the data, but mostly it just collects it to 6542make C<print_trace()>'s job easier. 6543 6544C<skip> defines the number of stack frames to be skipped, working backwards 6545from the most current. C<count> determines the total number of frames to 6546be returned; all of them (well, the first 10^9) are returned if C<count> 6547is omitted. 6548 6549This routine returns a list of hashes, from most-recent to least-recent 6550stack frame. Each has the following keys and values: 6551 6552=over 4 6553 6554=item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array) 6555 6556=item * C<sub> - subroutine name, or C<eval> information 6557 6558=item * C<args> - undef, or a reference to an array of arguments 6559 6560=item * C<file> - the file in which this item was defined (if any) 6561 6562=item * C<line> - the line on which it was defined 6563 6564=back 6565 6566=cut 6567 6568sub _dump_trace_calc_saved_single_arg 6569{ 6570 my ($nothard, $arg) = @_; 6571 6572 my $type; 6573 if ( not defined $arg ) { # undefined parameter 6574 return "undef"; 6575 } 6576 6577 elsif ( $nothard and tied $arg ) { # tied parameter 6578 return "tied"; 6579 } 6580 elsif ( $nothard and $type = ref $arg ) { # reference 6581 return "ref($type)"; 6582 } 6583 else { # can be stringified 6584 local $_ = 6585 "$arg"; # Safe to stringify now - should not call f(). 6586 6587 # Backslash any single-quotes or backslashes. 6588 s/([\'\\])/\\$1/g; 6589 6590 # Single-quote it unless it's a number or a colon-separated 6591 # name. 6592 s/(.*)/'$1'/s 6593 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x; 6594 6595 # Turn high-bit characters into meta-whatever, and controls into like 6596 # '^D'. 6597 require 'meta_notation.pm'; 6598 $_ = _meta_notation($_) if /[[:^print:]]/a; 6599 6600 return $_; 6601 } 6602} 6603 6604sub _dump_trace_calc_save_args { 6605 my ($nothard) = @_; 6606 6607 return [ 6608 map { _dump_trace_calc_saved_single_arg($nothard, $_) } @args 6609 ]; 6610} 6611 6612sub dump_trace { 6613 6614 # How many levels to skip. 6615 my $skip = shift; 6616 6617 # How many levels to show. (1e9 is a cheap way of saying "all of them"; 6618 # it's unlikely that we'll have more than a billion stack frames. If you 6619 # do, you've got an awfully big machine...) 6620 my $count = shift || 1e9; 6621 6622 # We increment skip because caller(1) is the first level *back* from 6623 # the current one. Add $skip to the count of frames so we have a 6624 # simple stop criterion, counting from $skip to $count+$skip. 6625 $skip++; 6626 $count += $skip; 6627 6628 # These variables are used to capture output from caller(); 6629 my ( $p, $file, $line, $sub, $h, $context ); 6630 6631 my ( $e, $r, @sub, $args ); 6632 6633 # XXX Okay... why'd we do that? 6634 my $nothard = not $frame & 8; 6635 local $frame = 0; 6636 6637 # Do not want to trace this. 6638 my $otrace = $trace; 6639 $trace = 0; 6640 6641 # Start out at the skip count. 6642 # If we haven't reached the number of frames requested, and caller() is 6643 # still returning something, stay in the loop. (If we pass the requested 6644 # number of stack frames, or we run out - caller() returns nothing - we 6645 # quit. 6646 # Up the stack frame index to go back one more level each time. 6647 for ( 6648 my $i = $skip ; 6649 $i < $count 6650 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ; 6651 $i++ 6652 ) 6653 { 6654 # if the sub has args ($h true), make an anonymous array of the 6655 # dumped args. 6656 my $args = $h ? _dump_trace_calc_save_args($nothard) : undef; 6657 6658 # If context is true, this is array (@)context. 6659 # If context is false, this is scalar ($) context. 6660 # If neither, context isn't defined. (This is apparently a 'can't 6661 # happen' trap.) 6662 $context = $context ? '@' : ( defined $context ? "\$" : '.' ); 6663 6664 # remove trailing newline-whitespace-semicolon-end of line sequence 6665 # from the eval text, if any. 6666 $e =~ s/\n\s*\;\s*\Z// if $e; 6667 6668 # Escape backslashed single-quotes again if necessary. 6669 $e =~ s/([\\\'])/\\$1/g if $e; 6670 6671 # if the require flag is true, the eval text is from a require. 6672 if ($r) { 6673 $sub = "require '$e'"; 6674 } 6675 6676 # if it's false, the eval text is really from an eval. 6677 elsif ( defined $r ) { 6678 $sub = "eval '$e'"; 6679 } 6680 6681 # If the sub is '(eval)', this is a block eval, meaning we don't 6682 # know what the eval'ed text actually was. 6683 elsif ( $sub eq '(eval)' ) { 6684 $sub = "eval {...}"; 6685 } 6686 6687 # Stick the collected information into @sub as an anonymous hash. 6688 push( 6689 @sub, 6690 { 6691 context => $context, 6692 sub => $sub, 6693 args => $args, 6694 file => $file, 6695 line => $line 6696 } 6697 ); 6698 6699 # Stop processing frames if the user hit control-C. 6700 last if $signal; 6701 } ## end for ($i = $skip ; $i < ... 6702 6703 # Restore the trace value again. 6704 $trace = $otrace; 6705 @sub; 6706} ## end sub dump_trace 6707 6708=head2 C<action()> 6709 6710C<action()> takes input provided as the argument to an add-action command, 6711either pre- or post-, and makes sure it's a complete command. It doesn't do 6712any fancy parsing; it just keeps reading input until it gets a string 6713without a trailing backslash. 6714 6715=cut 6716 6717sub action { 6718 my $action = shift; 6719 6720 while ( $action =~ s/\\$// ) { 6721 6722 # We have a backslash on the end. Read more. 6723 $action .= gets(); 6724 } ## end while ($action =~ s/\\$//) 6725 6726 # Return the assembled action. 6727 $action; 6728} ## end sub action 6729 6730=head2 unbalanced 6731 6732This routine mostly just packages up a regular expression to be used 6733to check that the thing it's being matched against has properly-matched 6734curly braces. 6735 6736Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which 6737speeds things up by only creating the qr//'ed expression once; if it's 6738already defined, we don't try to define it again. A speed hack. 6739 6740=cut 6741 6742use vars qw($balanced_brace_re); 6743 6744sub unbalanced { 6745 6746 # I hate using globals! 6747 $balanced_brace_re ||= qr{ 6748 ^ \{ 6749 (?: 6750 (?> [^{}] + ) # Non-parens without backtracking 6751 | 6752 (??{ $balanced_brace_re }) # Group with matching parens 6753 ) * 6754 \} $ 6755 }x; 6756 return $_[0] !~ m/$balanced_brace_re/; 6757} ## end sub unbalanced 6758 6759=head2 C<gets()> 6760 6761C<gets()> is a primitive (very primitive) routine to read continuations. 6762It was devised for reading continuations for actions. 6763it just reads more input with C<readline()> and returns it. 6764 6765=cut 6766 6767sub gets { 6768 return DB::readline("cont: "); 6769} 6770 6771=head2 C<_db_system()> - handle calls to<system()> without messing up the debugger 6772 6773The C<system()> function assumes that it can just go ahead and use STDIN and 6774STDOUT, but under the debugger, we want it to use the debugger's input and 6775outout filehandles. 6776 6777C<_db_system()> socks away the program's STDIN and STDOUT, and then substitutes 6778the debugger's IN and OUT filehandles for them. It does the C<system()> call, 6779and then puts everything back again. 6780 6781=cut 6782 6783sub _db_system { 6784 6785 # We save, change, then restore STDIN and STDOUT to avoid fork() since 6786 # some non-Unix systems can do system() but have problems with fork(). 6787 open( SAVEIN, "<&STDIN" ) || _db_warn("Can't save STDIN"); 6788 open( SAVEOUT, ">&STDOUT" ) || _db_warn("Can't save STDOUT"); 6789 open( STDIN, "<&IN" ) || _db_warn("Can't redirect STDIN"); 6790 open( STDOUT, ">&OUT" ) || _db_warn("Can't redirect STDOUT"); 6791 6792 # XXX: using csh or tcsh destroys sigint retvals! 6793 system(@_); 6794 open( STDIN, "<&SAVEIN" ) || _db_warn("Can't restore STDIN"); 6795 open( STDOUT, ">&SAVEOUT" ) || _db_warn("Can't restore STDOUT"); 6796 close(SAVEIN); 6797 close(SAVEOUT); 6798 6799 # most of the $? crud was coping with broken cshisms 6800 if ( $? >> 8 ) { 6801 _db_warn( "(Command exited ", ( $? >> 8 ), ")\n" ); 6802 } 6803 elsif ($?) { 6804 _db_warn( 6805 "(Command died of SIG#", 6806 ( $? & 127 ), 6807 ( ( $? & 128 ) ? " -- core dumped" : "" ), 6808 ")", "\n" 6809 ); 6810 } ## end elsif ($?) 6811 6812 return $?; 6813 6814} ## end sub system 6815 6816*system = \&_db_system; 6817 6818=head1 TTY MANAGEMENT 6819 6820The subs here do some of the terminal management for multiple debuggers. 6821 6822=head2 setterm 6823 6824Top-level function called when we want to set up a new terminal for use 6825by the debugger. 6826 6827If the C<noTTY> debugger option was set, we'll either use the terminal 6828supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous> 6829to find one. If we're a forked debugger, we call C<resetterm> to try to 6830get a whole new terminal if we can. 6831 6832In either case, we set up the terminal next. If the C<ReadLine> option was 6833true, we'll get a C<Term::ReadLine> object for the current terminal and save 6834the appropriate attributes. We then 6835 6836=cut 6837 6838use vars qw($ornaments); 6839use vars qw($rl_attribs); 6840sub setterm { 6841 6842 # Load Term::Readline, but quietly; don't debug it and don't trace it. 6843 local $frame = 0; 6844 local $doret = -2; 6845 _DB__use_full_path(sub { 6846 require Term::ReadLine; 6847 }); 6848 6849 6850 # If noTTY is set, but we have a TTY name, go ahead and hook up to it. 6851 if ($notty) { 6852 if ($tty) { 6853 my ( $i, $o ) = split $tty, /,/; 6854 $o = $i unless defined $o; 6855 open( IN, '<', $i ) or die "Cannot open TTY '$i' for read: $!"; 6856 open( OUT, '>', $o ) or die "Cannot open TTY '$o' for write: $!"; 6857 $IN = \*IN; 6858 $OUT = \*OUT; 6859 _autoflush($OUT); 6860 } ## end if ($tty) 6861 6862 # We don't have a TTY - try to find one via Term::Rendezvous. 6863 else { 6864 require Term::Rendezvous; 6865 6866 # See if we have anything to pass to Term::Rendezvous. 6867 # Use $HOME/.perldbtty$$ if not. 6868 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$"; 6869 6870 # Rendezvous and get the filehandles. 6871 my $term_rv = Term::Rendezvous->new( $rv ); 6872 $IN = $term_rv->IN; 6873 $OUT = $term_rv->OUT; 6874 } ## end else [ if ($tty) 6875 } ## end if ($notty) 6876 6877 # We're a daughter debugger. Try to fork off another TTY. 6878 if ( $term_pid eq '-1' ) { # In a TTY with another debugger 6879 resetterm(2); 6880 } 6881 6882 # If we shouldn't use Term::ReadLine, don't. 6883 if ( !$rl ) { 6884 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 6885 } 6886 6887 # We're using Term::ReadLine. Get all the attributes for this terminal. 6888 else { 6889 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 6890 6891 $rl_attribs = $term->Attribs; 6892 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}' 6893 if defined $rl_attribs->{basic_word_break_characters} 6894 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1; 6895 $rl_attribs->{special_prefixes} = '$@&%'; 6896 $rl_attribs->{completer_word_break_characters} .= '$@&%'; 6897 $rl_attribs->{completion_function} = \&db_complete; 6898 } ## end else [ if (!$rl) 6899 6900 # Set up the LINEINFO filehandle. 6901 $LINEINFO = $OUT unless defined $LINEINFO; 6902 $lineinfo = $console unless defined $lineinfo; 6903 6904 $term->MinLine(2); 6905 6906 load_hist(); 6907 6908 if ( $term->Features->{setHistory} and "@hist" ne "?" ) { 6909 $term->SetHistory(@hist); 6910 } 6911 6912 # XXX Ornaments are turned on unconditionally, which is not 6913 # always a good thing. 6914 ornaments($ornaments) if defined $ornaments; 6915 $term_pid = $$; 6916} ## end sub setterm 6917 6918sub load_hist { 6919 $histfile //= option_val("HistFile", undef); 6920 return unless defined $histfile; 6921 open my $fh, "<", $histfile or return; 6922 local $/ = "\n"; 6923 @hist = (); 6924 while (<$fh>) { 6925 chomp; 6926 push @hist, $_; 6927 } 6928 close $fh; 6929} 6930 6931sub save_hist { 6932 return unless defined $histfile; 6933 eval { require File::Path } or return; 6934 eval { require File::Basename } or return; 6935 File::Path::mkpath(File::Basename::dirname($histfile)); 6936 open my $fh, ">", $histfile or die "Could not open '$histfile': $!"; 6937 $histsize //= option_val("HistSize",100); 6938 my @copy = grep { $_ ne '?' } @hist; 6939 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0; 6940 for ($start .. $#copy) { 6941 print $fh "$copy[$_]\n"; 6942 } 6943 close $fh or die "Could not write '$histfile': $!"; 6944} 6945 6946=head1 GET_FORK_TTY EXAMPLE FUNCTIONS 6947 6948When the process being debugged forks, or the process invokes a command 6949via C<system()> which starts a new debugger, we need to be able to get a new 6950C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes 6951fight over the terminal, and you can never quite be sure who's going to get the 6952input you're typing. 6953 6954C<get_fork_TTY> is a glob-aliased function which calls the real function that 6955is tasked with doing all the necessary operating system mojo to get a new 6956TTY (and probably another window) and to direct the new debugger to read and 6957write there. 6958 6959The debugger provides C<get_fork_TTY> functions which work for TCP 6960socket servers, X11, OS/2, and Mac OS X. Other systems are not 6961supported. You are encouraged to write C<get_fork_TTY> functions which 6962work for I<your> platform and contribute them. 6963 6964=head3 C<socket_get_fork_TTY> 6965 6966=cut 6967 6968sub connect_remoteport { 6969 require IO::Socket; 6970 6971 my $socket = IO::Socket::INET->new( 6972 Timeout => '10', 6973 PeerAddr => $remoteport, 6974 Proto => 'tcp', 6975 ); 6976 if ( ! $socket ) { 6977 die "Unable to connect to remote host: $remoteport\n"; 6978 } 6979 return $socket; 6980} 6981 6982sub socket_get_fork_TTY { 6983 $tty = $LINEINFO = $IN = $OUT = connect_remoteport(); 6984 6985 # Do I need to worry about setting $term? 6986 6987 reset_IN_OUT( $IN, $OUT ); 6988 return ''; 6989} 6990 6991=head3 C<xterm_get_fork_TTY> 6992 6993This function provides the C<get_fork_TTY> function for X11. If a 6994program running under the debugger forks, a new <xterm> window is opened and 6995the subsidiary debugger is directed there. 6996 6997The C<open()> call is of particular note here. We have the new C<xterm> 6998we're spawning route file number 3 to STDOUT, and then execute the C<tty> 6999command (which prints the device name of the TTY we'll want to use for input 7000and output to STDOUT, then C<sleep> for a very long time, routing this output 7001to file number 3. This way we can simply read from the <XT> filehandle (which 7002is STDOUT from the I<commands> we ran) to get the TTY we want to use. 7003 7004Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are 7005properly set up. 7006 7007=cut 7008 7009sub xterm_get_fork_TTY { 7010 ( my $name = $0 ) =~ s,^.*[/\\],,s; 7011 open XT, 7012qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\ 7013 sleep 10000000' |]; 7014 7015 # Get the output from 'tty' and clean it up a little. 7016 my $tty = <XT>; 7017 chomp $tty; 7018 7019 $pidprompt = ''; # Shown anyway in titlebar 7020 7021 # We need $term defined or we can not switch to the newly created xterm 7022 if ($tty ne '' && !defined $term) { 7023 _DB__use_full_path(sub { 7024 require Term::ReadLine; 7025 }); 7026 if ( !$rl ) { 7027 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 7028 } 7029 else { 7030 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 7031 } 7032 } 7033 # There's our new TTY. 7034 return $tty; 7035} ## end sub xterm_get_fork_TTY 7036 7037=head3 C<os2_get_fork_TTY> 7038 7039XXX It behooves an OS/2 expert to write the necessary documentation for this! 7040 7041=cut 7042 7043# This example function resets $IN, $OUT itself 7044my $c_pipe = 0; 7045sub os2_get_fork_TTY { # A simplification of the following (and works without): 7046 local $\ = ''; 7047 ( my $name = $0 ) =~ s,^.*[/\\],,s; 7048 my %opt = ( title => "Daughter Perl debugger $pids $name", 7049 ($rl ? (read_by_key => 1) : ()) ); 7050 require OS2::Process; 7051 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) } 7052 or return; 7053 $pidprompt = ''; # Shown anyway in titlebar 7054 reset_IN_OUT($in, $out); 7055 $tty = '*reset*'; 7056 return ''; # Indicate that reset_IN_OUT is called 7057} ## end sub os2_get_fork_TTY 7058 7059=head3 C<macosx_get_fork_TTY> 7060 7061The Mac OS X version uses AppleScript to tell Terminal.app to create 7062a new window. 7063 7064=cut 7065 7066# Notes about Terminal.app's AppleScript support, 7067# (aka things that might break in future OS versions). 7068# 7069# The "do script" command doesn't return a reference to the new window 7070# it creates, but since it appears frontmost and windows are enumerated 7071# front to back, we can use "first window" === "window 1". 7072# 7073# Since "do script" is implemented by supplying the argument (plus a 7074# return character) as terminal input, there's a potential race condition 7075# where the debugger could beat the shell to reading the command. 7076# To prevent this, we wait for the screen to clear before proceeding. 7077# 7078# 10.3 and 10.4: 7079# There's no direct accessor for the tty device name, so we fiddle 7080# with the window title options until it says what we want. 7081# 7082# 10.5: 7083# There _is_ a direct accessor for the tty device name, _and_ there's 7084# a new possible component of the window title (the name of the settings 7085# set). A separate version is needed. 7086 7087my @script_versions= 7088 7089 ([237, <<'__LEOPARD__'], 7090tell application "Terminal" 7091 do script "clear;exec sleep 100000" 7092 tell first tab of first window 7093 copy tty to thetty 7094 set custom title to "forked perl debugger" 7095 set title displays custom title to true 7096 repeat while (length of first paragraph of (get contents)) > 0 7097 delay 0.1 7098 end repeat 7099 end tell 7100end tell 7101thetty 7102__LEOPARD__ 7103 7104 [100, <<'__JAGUAR_TIGER__'], 7105tell application "Terminal" 7106 do script "clear;exec sleep 100000" 7107 tell first window 7108 set title displays shell path to false 7109 set title displays window size to false 7110 set title displays file name to false 7111 set title displays device name to true 7112 set title displays custom title to true 7113 set custom title to "" 7114 copy "/dev/" & name to thetty 7115 set custom title to "forked perl debugger" 7116 repeat while (length of first paragraph of (get contents)) > 0 7117 delay 0.1 7118 end repeat 7119 end tell 7120end tell 7121thetty 7122__JAGUAR_TIGER__ 7123 7124); 7125 7126sub macosx_get_fork_TTY 7127{ 7128 my($version,$script,$pipe,$tty); 7129 7130 return unless $version=$ENV{TERM_PROGRAM_VERSION}; 7131 foreach my $entry (@script_versions) { 7132 if ($version>=$entry->[0]) { 7133 $script=$entry->[1]; 7134 last; 7135 } 7136 } 7137 return unless defined($script); 7138 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script); 7139 $tty=readline($pipe); 7140 close($pipe); 7141 return unless defined($tty) && $tty =~ m(^/dev/); 7142 chomp $tty; 7143 return $tty; 7144} 7145 7146=head3 C<tmux_get_fork_TTY> 7147 7148Creates a split window for subprocesses when a process running under the 7149perl debugger in Tmux forks. 7150 7151=cut 7152 7153sub tmux_get_fork_TTY { 7154 return unless $ENV{TMUX}; 7155 7156 my $pipe; 7157 7158 my $status = open $pipe, '-|', 'tmux', 'split-window', 7159 '-P', '-F', '#{pane_tty}', 'sleep 100000'; 7160 7161 if ( !$status ) { 7162 return; 7163 } 7164 7165 my $tty = <$pipe>; 7166 close $pipe; 7167 7168 if ( $tty ) { 7169 chomp $tty; 7170 7171 if ( !defined $term ) { 7172 require Term::ReadLine; 7173 if ( !$rl ) { 7174 $term = Term::ReadLine::Stub->new( 'perldb', $IN, $OUT ); 7175 } 7176 else { 7177 $term = Term::ReadLine->new( 'perldb', $IN, $OUT ); 7178 } 7179 } 7180 } 7181 7182 return $tty; 7183} 7184 7185=head2 C<create_IN_OUT($flags)> 7186 7187Create a new pair of filehandles, pointing to a new TTY. If impossible, 7188try to diagnose why. 7189 7190Flags are: 7191 7192=over 4 7193 7194=item * 1 - Don't know how to create a new TTY. 7195 7196=item * 2 - Debugger has forked, but we can't get a new TTY. 7197 7198=item * 4 - standard debugger startup is happening. 7199 7200=back 7201 7202=cut 7203 7204use vars qw($fork_TTY); 7205 7206sub create_IN_OUT { # Create a window with IN/OUT handles redirected there 7207 7208 # If we know how to get a new TTY, do it! $in will have 7209 # the TTY name if get_fork_TTY works. 7210 my $in = get_fork_TTY(@_) if defined &get_fork_TTY; 7211 7212 # It used to be that 7213 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility 7214 7215 if ( not defined $in ) { 7216 my $why = shift; 7217 7218 # We don't know how. 7219 print_help(<<EOP) if $why == 1; 7220I<#########> Forked, but do not know how to create a new B<TTY>. I<#########> 7221EOP 7222 7223 # Forked debugger. 7224 print_help(<<EOP) if $why == 2; 7225I<#########> Daughter session, do not know how to change a B<TTY>. I<#########> 7226 This may be an asynchronous session, so the parent debugger may be active. 7227EOP 7228 7229 # Note that both debuggers are fighting over the same input. 7230 print_help(<<EOP) if $why != 4; 7231 Since two debuggers fight for the same TTY, input is severely entangled. 7232 7233EOP 7234 print_help(<<EOP); 7235 I know how to switch the output to a different window in xterms, OS/2 7236 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name 7237 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function 7238 B<DB::get_fork_TTY()> returning this. 7239 7240 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window 7241 by typing B<tty>, and disconnect the I<shell> from I<TTY> by S<B<sleep 1000000>>. 7242 7243EOP 7244 } ## end if (not defined $in) 7245 elsif ( $in ne '' ) { 7246 TTY($in); 7247 } 7248 else { 7249 $console = ''; # Indicate no need to open-from-the-console 7250 } 7251 undef $fork_TTY; 7252} ## end sub create_IN_OUT 7253 7254=head2 C<resetterm> 7255 7256Handles rejiggering the prompt when we've forked off a new debugger. 7257 7258If the new debugger happened because of a C<system()> that invoked a 7259program under the debugger, the arrow between the old pid and the new 7260in the prompt has I<two> dashes instead of one. 7261 7262We take the current list of pids and add this one to the end. If there 7263isn't any list yet, we make one up out of the initial pid associated with 7264the terminal and our new pid, sticking an arrow (either one-dashed or 7265two dashed) in between them. 7266 7267If C<CreateTTY> is off, or C<resetterm> was called with no arguments, 7268we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead 7269and try to do that. 7270 7271=cut 7272 7273sub resetterm { # We forked, so we need a different TTY 7274 7275 # Needs to be passed to create_IN_OUT() as well. 7276 my $in = shift; 7277 7278 # resetterm(2): got in here because of a system() starting a debugger. 7279 # resetterm(1): just forked. 7280 my $systemed = $in > 1 ? '-' : ''; 7281 7282 # If there's already a list of pids, add this to the end. 7283 if ($pids) { 7284 $pids =~ s/\]/$systemed->$$]/; 7285 } 7286 7287 # No pid list. Time to make one. 7288 else { 7289 $pids = "[$term_pid->$$]"; 7290 } 7291 7292 # The prompt we're going to be using for this debugger. 7293 $pidprompt = $pids; 7294 7295 # We now 0wnz this terminal. 7296 $term_pid = $$; 7297 7298 # Just return if we're not supposed to try to create a new TTY. 7299 return unless $CreateTTY & $in; 7300 7301 # Try to create a new IN/OUT pair. 7302 create_IN_OUT($in); 7303} ## end sub resetterm 7304 7305=head2 C<readline> 7306 7307First, we handle stuff in the typeahead buffer. If there is any, we shift off 7308the next line, print a message saying we got it, add it to the terminal 7309history (if possible), and return it. 7310 7311If there's nothing in the typeahead buffer, check the command filehandle stack. 7312If there are any filehandles there, read from the last one, and return the line 7313if we got one. If not, we pop the filehandle off and close it, and try the 7314next one up the stack. 7315 7316If we've emptied the filehandle stack, we check to see if we've got a socket 7317open, and we read that and return it if we do. If we don't, we just call the 7318core C<readline()> and return its value. 7319 7320=cut 7321 7322sub readline { 7323 7324 # Localize to prevent it from being smashed in the program being debugged. 7325 local $.; 7326 7327 # If there are stacked filehandles to read from ... 7328 # (Handle it before the typeahead, because we may call source/etc. from 7329 # the typeahead.) 7330 while (@cmdfhs) { 7331 7332 # Read from the last one in the stack. 7333 my $line = CORE::readline( $cmdfhs[-1] ); 7334 7335 # If we got a line ... 7336 defined $line 7337 ? ( print $OUT ">> $line" and return $line ) # Echo and return 7338 : close pop @cmdfhs; # Pop and close 7339 } ## end while (@cmdfhs) 7340 7341 # Pull a line out of the typeahead if there's stuff there. 7342 if (@typeahead) { 7343 7344 # How many lines left. 7345 my $left = @typeahead; 7346 7347 # Get the next line. 7348 my $got = shift @typeahead; 7349 7350 # Print a message saying we got input from the typeahead. 7351 local $\ = ''; 7352 print $OUT "auto(-$left)", shift, $got, "\n"; 7353 7354 # Add it to the terminal history (if possible). 7355 $term->AddHistory($got) 7356 if length($got) >= option_val("HistItemMinLength", 2) 7357 and defined $term->Features->{addHistory}; 7358 return $got; 7359 } ## end if (@typeahead) 7360 7361 # We really need to read some input. Turn off entry/exit trace and 7362 # return value printing. 7363 local $frame = 0; 7364 local $doret = -2; 7365 7366 # Nothing on the filehandle stack. Socket? 7367 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) { 7368 7369 # Send anything we have to send. 7370 $OUT->write( join( '', @_ ) ); 7371 7372 # Receive anything there is to receive. 7373 my $stuff = ''; 7374 my $buf; 7375 my $first_time = 1; 7376 7377 while ($first_time or (length($buf) && ($stuff .= $buf) !~ /\n/)) 7378 { 7379 $first_time = 0; 7380 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?" 7381 # XXX Don't know. You tell me. 7382 } 7383 7384 # What we got. 7385 return $stuff; 7386 } ## end if (ref $OUT and UNIVERSAL::isa... 7387 7388 # No socket. Just read from the terminal. 7389 else { 7390 return $term->readline(@_); 7391 } 7392} ## end sub readline 7393 7394=head1 OPTIONS SUPPORT ROUTINES 7395 7396These routines handle listing and setting option values. 7397 7398=head2 C<dump_option> - list the current value of an option setting 7399 7400This routine uses C<option_val> to look up the value for an option. 7401It cleans up escaped single-quotes and then displays the option and 7402its value. 7403 7404=cut 7405 7406sub dump_option { 7407 my ( $opt, $val ) = @_; 7408 $val = option_val( $opt, 'N/A' ); 7409 $val =~ s/([\\\'])/\\$1/g; 7410 printf $OUT "%20s = '%s'\n", $opt, $val; 7411} ## end sub dump_option 7412 7413sub options2remember { 7414 foreach my $k (@RememberOnROptions) { 7415 $option{$k} = option_val( $k, 'N/A' ); 7416 } 7417 return %option; 7418} 7419 7420=head2 C<option_val> - find the current value of an option 7421 7422This can't just be a simple hash lookup because of the indirect way that 7423the option values are stored. Some are retrieved by calling a subroutine, 7424some are just variables. 7425 7426You must supply a default value to be used in case the option isn't set. 7427 7428=cut 7429 7430sub option_val { 7431 my ( $opt, $default ) = @_; 7432 my $val; 7433 7434 # Does this option exist, and is it a variable? 7435 # If so, retrieve the value via the value in %optionVars. 7436 if ( defined $optionVars{$opt} 7437 and defined ${ $optionVars{$opt} } ) 7438 { 7439 $val = ${ $optionVars{$opt} }; 7440 } 7441 7442 # Does this option exist, and it's a subroutine? 7443 # If so, call the subroutine via the ref in %optionAction 7444 # and capture the value. 7445 elsif ( defined $optionAction{$opt} 7446 and defined &{ $optionAction{$opt} } ) 7447 { 7448 $val = &{ $optionAction{$opt} }(); 7449 } 7450 7451 # If there's an action or variable for the supplied option, 7452 # but no value was set, use the default. 7453 elsif (defined $optionAction{$opt} and not defined $option{$opt} 7454 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } ) 7455 { 7456 $val = $default; 7457 } 7458 7459 # Otherwise, do the simple hash lookup. 7460 else { 7461 $val = $option{$opt}; 7462 } 7463 7464 # If the value isn't defined, use the default. 7465 # Then return whatever the value is. 7466 $val = $default unless defined $val; 7467 $val; 7468} ## end sub option_val 7469 7470=head2 C<parse_options> 7471 7472Handles the parsing and execution of option setting/displaying commands. 7473 7474An option entered by itself is assumed to be I<set me to 1> (the default value) 7475if the option is a boolean one. If not, the user is prompted to enter a valid 7476value or to query the current value (via C<option? >). 7477 7478If C<option=value> is entered, we try to extract a quoted string from the 7479value (if it is quoted). If it's not, we just use the whole value as-is. 7480 7481We load any modules required to service this option, and then we set it: if 7482it just gets stuck in a variable, we do that; if there's a subroutine to 7483handle setting the option, we call that. 7484 7485Finally, if we're running in interactive mode, we display the effect of the 7486user's command back to the terminal, skipping this if we're setting things 7487during initialization. 7488 7489=cut 7490 7491sub parse_options { 7492 my ($s) = @_; 7493 local $\ = ''; 7494 7495 my $option; 7496 7497 # These options need a value. Don't allow them to be clobbered by accident. 7498 my %opt_needs_val = map { ( $_ => 1 ) } qw{ 7499 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize 7500 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet 7501 }; 7502 7503 while (length($s)) { 7504 my $val_defaulted; 7505 7506 # Clean off excess leading whitespace. 7507 $s =~ s/^\s+// && next; 7508 7509 # Options are always all word characters, followed by a non-word 7510 # separator. 7511 if ($s !~ s/^(\w+)(\W?)//) { 7512 print {$OUT} "Invalid option '$s'\n"; 7513 last; 7514 } 7515 my ( $opt, $sep ) = ( $1, $2 ); 7516 7517 # Make sure that such an option exists. 7518 my $matches = ( grep { /^\Q$opt/ && ( $option = $_ ) } @options ) 7519 || ( grep { /^\Q$opt/i && ( $option = $_ ) } @options ); 7520 7521 unless ($matches) { 7522 print {$OUT} "Unknown option '$opt'\n"; 7523 next; 7524 } 7525 if ($matches > 1) { 7526 print {$OUT} "Ambiguous option '$opt'\n"; 7527 next; 7528 } 7529 my $val; 7530 7531 # '?' as separator means query, but must have whitespace after it. 7532 if ( "?" eq $sep ) { 7533 if ($s =~ /\A\S/) { 7534 print {$OUT} "Option query '$opt?' followed by non-space '$s'\n" ; 7535 7536 last; 7537 } 7538 7539 #&dump_option($opt); 7540 } ## end if ("?" eq $sep) 7541 7542 # Separator is whitespace (or just a carriage return). 7543 # They're going for a default, which we assume is 1. 7544 elsif ( $sep !~ /\S/ ) { 7545 $val_defaulted = 1; 7546 $val = "1"; # this is an evil default; make 'em set it! 7547 } 7548 7549 # Separator is =. Trying to set a value. 7550 elsif ( $sep eq "=" ) { 7551 7552 # If quoted, extract a quoted string. 7553 if ($s =~ s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) { 7554 my $quote = $1; 7555 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g; 7556 } 7557 7558 # Not quoted. Use the whole thing. Warn about 'option='. 7559 else { 7560 $s =~ s/^(\S*)//; 7561 $val = $1; 7562 print OUT qq(Option better cleared using $opt=""\n) 7563 unless length $val; 7564 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) 7565 7566 } ## end elsif ($sep eq "=") 7567 7568 # "Quoted" with [], <>, or {}. 7569 else { #{ to "let some poor schmuck bounce on the % key in B<vi>." 7570 my ($end) = 7571 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #} 7572 $s =~ s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)// 7573 or print( $OUT "Unclosed option value '$opt$sep$_'\n" ), last; 7574 ( $val = $1 ) =~ s/\\([\\$end])/$1/g; 7575 } ## end else [ if ("?" eq $sep) 7576 7577 # Exclude non-booleans from getting set to 1 by default. 7578 if ( $opt_needs_val{$option} && $val_defaulted ) { 7579 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O'; 7580 print {$OUT} 7581"Option '$opt' is non-boolean. Use '$cmd $option=VAL' to set, '$cmd $option?' to query\n"; 7582 next; 7583 } ## end if ($opt_needs_val{$option... 7584 7585 # Save the option value. 7586 $option{$option} = $val if defined $val; 7587 7588 # Load any module that this option requires. 7589 if ( defined($optionRequire{$option}) && defined($val) ) { 7590 eval qq{ 7591 local \$frame = 0; 7592 local \$doret = -2; 7593 require '$optionRequire{$option}'; 7594 1; 7595 } || die $@ # XXX: shouldn't happen 7596 } 7597 7598 # Set it. 7599 # Stick it in the proper variable if it goes in a variable. 7600 if (defined($optionVars{$option}) && defined($val)) { 7601 ${ $optionVars{$option} } = $val; 7602 } 7603 7604 # Call the appropriate sub if it gets set via sub. 7605 if (defined($optionAction{$option}) 7606 && defined (&{ $optionAction{$option} }) 7607 && defined ($val)) 7608 { 7609 &{ $optionAction{$option} }($val); 7610 } 7611 7612 # Not initialization - echo the value we set it to. 7613 dump_option($option) if ($OUT ne \*STDERR); 7614 } ## end while (length) 7615} ## end sub parse_options 7616 7617=head1 RESTART SUPPORT 7618 7619These routines are used to store (and restore) lists of items in environment 7620variables during a restart. 7621 7622=head2 set_list 7623 7624Set_list packages up items to be stored in a set of environment variables 7625(VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing 7626the values). Values outside the standard ASCII charset are stored by encoding 7627them as hexadecimal values. 7628 7629=cut 7630 7631sub set_list { 7632 my ( $stem, @list ) = @_; 7633 my $val; 7634 7635 # VAR_n: how many we have. Scalar assignment gets the number of items. 7636 $ENV{"${stem}_n"} = @list; 7637 7638 # Grab each item in the list, escape the backslashes, encode the non-ASCII 7639 # as hex, and then save in the appropriate VAR_0, VAR_1, etc. 7640 for my $i ( 0 .. $#list ) { 7641 $val = $list[$i]; 7642 $val =~ s/\\/\\\\/g; 7643 $val =~ s/ ( (?[ [\000-\xFF] & [:^print:] ]) ) / 7644 "\\0x" . unpack('H2',$1)/xaeg; 7645 $ENV{"${stem}_$i"} = $val; 7646 } ## end for $i (0 .. $#list) 7647} ## end sub set_list 7648 7649=head2 get_list 7650 7651Reverse the set_list operation: grab VAR_n to see how many we should be getting 7652back, and then pull VAR_0, VAR_1. etc. back out. 7653 7654=cut 7655 7656sub get_list { 7657 my $stem = shift; 7658 my @list; 7659 my $n = delete $ENV{"${stem}_n"}; 7660 my $val; 7661 for my $i ( 0 .. $n - 1 ) { 7662 $val = delete $ENV{"${stem}_$i"}; 7663 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge; 7664 push @list, $val; 7665 } 7666 @list; 7667} ## end sub get_list 7668 7669=head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT 7670 7671=head2 catch() 7672 7673The C<catch()> subroutine is the essence of fast and low-impact. We simply 7674set an already-existing global scalar variable to a constant value. This 7675avoids allocating any memory possibly in the middle of something that will 7676get all confused if we do, particularly under I<unsafe signals>. 7677 7678=cut 7679 7680sub catch { 7681 $signal = 1; 7682 return; # Put nothing on the stack - malloc/free land! 7683} 7684 7685=head2 C<warn()> 7686 7687C<warn> emits a warning, by joining together its arguments and printing 7688them, with couple of fillips. 7689 7690If the composited message I<doesn't> end with a newline, we automatically 7691add C<$!> and a newline to the end of the message. The subroutine expects $OUT 7692to be set to the filehandle to be used to output warnings; it makes no 7693assumptions about what filehandles are available. 7694 7695=cut 7696 7697sub _db_warn { 7698 my ($msg) = join( "", @_ ); 7699 $msg .= ": $!\n" unless $msg =~ /\n$/; 7700 local $\ = ''; 7701 print $OUT $msg; 7702} ## end sub warn 7703 7704*warn = \&_db_warn; 7705 7706=head1 INITIALIZATION TTY SUPPORT 7707 7708=head2 C<reset_IN_OUT> 7709 7710This routine handles restoring the debugger's input and output filehandles 7711after we've tried and failed to move them elsewhere. In addition, it assigns 7712the debugger's output filehandle to $LINEINFO if it was already open there. 7713 7714=cut 7715 7716sub reset_IN_OUT { 7717 my $switch_li = $LINEINFO eq $OUT; 7718 7719 # If there's a term and it's able to get a new tty, try to get one. 7720 if ( $term and $term->Features->{newTTY} ) { 7721 ( $IN, $OUT ) = ( shift, shift ); 7722 $term->newTTY( $IN, $OUT ); 7723 } 7724 7725 # This term can't get a new tty now. Better luck later. 7726 elsif ($term) { 7727 _db_warn("Too late to set IN/OUT filehandles, enabled on next 'R'!\n"); 7728 } 7729 7730 # Set the filehndles up as they were. 7731 else { 7732 ( $IN, $OUT ) = ( shift, shift ); 7733 } 7734 7735 # Unbuffer the output filehandle. 7736 _autoflush($OUT); 7737 7738 # Point LINEINFO to the same output filehandle if it was there before. 7739 $LINEINFO = $OUT if $switch_li; 7740} ## end sub reset_IN_OUT 7741 7742=head1 OPTION SUPPORT ROUTINES 7743 7744The following routines are used to process some of the more complicated 7745debugger options. 7746 7747=head2 C<TTY> 7748 7749Sets the input and output filehandles to the specified files or pipes. 7750If the terminal supports switching, we go ahead and do it. If not, and 7751there's already a terminal in place, we save the information to take effect 7752on restart. 7753 7754If there's no terminal yet (for instance, during debugger initialization), 7755we go ahead and set C<$console> and C<$tty> to the file indicated. 7756 7757=cut 7758 7759sub TTY { 7760 7761 if ( @_ and $term and $term->Features->{newTTY} ) { 7762 7763 # This terminal supports switching to a new TTY. 7764 # Can be a list of two files, or on string containing both names, 7765 # comma-separated. 7766 # XXX Should this perhaps be an assignment from @_? 7767 my ( $in, $out ) = shift; 7768 if ( $in =~ /,/ ) { 7769 7770 # Split list apart if supplied. 7771 ( $in, $out ) = split /,/, $in, 2; 7772 } 7773 else { 7774 7775 # Use the same file for both input and output. 7776 $out = $in; 7777 } 7778 7779 # Open file onto the debugger's filehandles, if you can. 7780 open IN, '<', $in or die "cannot open '$in' for read: $!"; 7781 open OUT, '>', $out or die "cannot open '$out' for write: $!"; 7782 7783 # Swap to the new filehandles. 7784 reset_IN_OUT( \*IN, \*OUT ); 7785 7786 # Save the setting for later. 7787 return $tty = $in; 7788 } ## end if (@_ and $term and $term... 7789 7790 # Terminal doesn't support new TTY, or doesn't support readline. 7791 # Can't do it now, try restarting. 7792 if ($term and @_) { 7793 _db_warn("Too late to set TTY, enabled on next 'R'!\n"); 7794 } 7795 7796 # Useful if done through PERLDB_OPTS: 7797 $console = $tty = shift if @_; 7798 7799 # Return whatever the TTY is. 7800 $tty or $console; 7801} ## end sub TTY 7802 7803=head2 C<noTTY> 7804 7805Sets the C<$notty> global, controlling whether or not the debugger tries to 7806get a terminal to read from. If called after a terminal is already in place, 7807we save the value to use it if we're restarted. 7808 7809=cut 7810 7811sub noTTY { 7812 if ($term) { 7813 _db_warn("Too late to set noTTY, enabled on next 'R'!\n") if @_; 7814 } 7815 $notty = shift if @_; 7816 $notty; 7817} ## end sub noTTY 7818 7819=head2 C<ReadLine> 7820 7821Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub> 7822(essentially, no C<readline> processing on this I<terminal>). Otherwise, we 7823use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save 7824the value in case a restart is done so we can change it then. 7825 7826=cut 7827 7828sub ReadLine { 7829 if ($term) { 7830 _db_warn("Too late to set ReadLine, enabled on next 'R'!\n") if @_; 7831 } 7832 $rl = shift if @_; 7833 $rl; 7834} ## end sub ReadLine 7835 7836=head2 C<RemotePort> 7837 7838Sets the port that the debugger will try to connect to when starting up. 7839If the terminal's already been set up, we can't do it, but we remember the 7840setting in case the user does a restart. 7841 7842=cut 7843 7844sub RemotePort { 7845 if ($term) { 7846 _db_warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_; 7847 } 7848 $remoteport = shift if @_; 7849 $remoteport; 7850} ## end sub RemotePort 7851 7852=head2 C<tkRunning> 7853 7854Checks with the terminal to see if C<Tk> is running, and returns true or 7855false. Returns false if the current terminal doesn't support C<readline>. 7856 7857=cut 7858 7859sub tkRunning { 7860 if ( ${ $term->Features }{tkRunning} ) { 7861 return $term->tkRunning(@_); 7862 } 7863 else { 7864 local $\ = ''; 7865 print $OUT "tkRunning not supported by current ReadLine package.\n"; 7866 0; 7867 } 7868} ## end sub tkRunning 7869 7870=head2 C<NonStop> 7871 7872Sets nonstop mode. If a terminal's already been set up, it's too late; the 7873debugger remembers the setting in case you restart, though. 7874 7875=cut 7876 7877sub NonStop { 7878 if ($term) { 7879 _db_warn("Too late to set up NonStop mode, enabled on next 'R'!\n") 7880 if @_; 7881 } 7882 $runnonstop = shift if @_; 7883 $runnonstop; 7884} ## end sub NonStop 7885 7886sub DollarCaretP { 7887 if ($term) { 7888 _db_warn("Some flag changes could not take effect until next 'R'!\n") 7889 if @_; 7890 } 7891 $^P = parse_DollarCaretP_flags(shift) if @_; 7892 expand_DollarCaretP_flags($^P); 7893} 7894 7895=head2 C<pager> 7896 7897Set up the C<$pager> variable. Adds a pipe to the front unless there's one 7898there already. 7899 7900=cut 7901 7902sub pager { 7903 if (@_) { 7904 $pager = shift; 7905 $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/; 7906 } 7907 $pager; 7908} ## end sub pager 7909 7910=head2 C<shellBang> 7911 7912Sets the shell escape command, and generates a printable copy to be used 7913in the help. 7914 7915=cut 7916 7917sub shellBang { 7918 7919 # If we got an argument, meta-quote it, and add '\b' if it 7920 # ends in a word character. 7921 if (@_) { 7922 $sh = quotemeta shift; 7923 $sh .= "\\b" if $sh =~ /\w$/; 7924 } 7925 7926 # Generate the printable version for the help: 7927 $psh = $sh; # copy it 7928 $psh =~ s/\\b$//; # Take off trailing \b if any 7929 $psh =~ s/\\(.)/$1/g; # De-escape 7930 $psh; # return the printable version 7931} ## end sub shellBang 7932 7933=head2 C<ornaments> 7934 7935If the terminal has its own ornaments, fetch them. Otherwise accept whatever 7936was passed as the argument. (This means you can't override the terminal's 7937ornaments.) 7938 7939=cut 7940 7941sub ornaments { 7942 if ( defined $term ) { 7943 7944 # We don't want to show warning backtraces, but we do want die() ones. 7945 local $warnLevel = 0; 7946 local $dieLevel = 1; 7947 7948 # No ornaments if the terminal doesn't support them. 7949 if (not $term->Features->{ornaments}) { 7950 return ''; 7951 } 7952 7953 return (eval { $term->ornaments(@_) } || ''); 7954 } 7955 7956 # Use what was passed in if we can't determine it ourselves. 7957 else { 7958 $ornaments = shift; 7959 7960 return $ornaments; 7961 } 7962 7963} ## end sub ornaments 7964 7965=head2 C<recallCommand> 7966 7967Sets the recall command, and builds a printable version which will appear in 7968the help text. 7969 7970=cut 7971 7972sub recallCommand { 7973 7974 # If there is input, metaquote it. Add '\b' if it ends with a word 7975 # character. 7976 if (@_) { 7977 $rc = quotemeta shift; 7978 $rc .= "\\b" if $rc =~ /\w$/; 7979 } 7980 7981 # Build it into a printable version. 7982 $prc = $rc; # Copy it 7983 $prc =~ s/\\b$//; # Remove trailing \b 7984 $prc =~ s/\\(.)/$1/g; # Remove escapes 7985 return $prc; # Return the printable version 7986} ## end sub recallCommand 7987 7988=head2 C<LineInfo> - where the line number information goes 7989 7990Called with no arguments, returns the file or pipe that line info should go to. 7991 7992Called with an argument (a file or a pipe), it opens that onto the 7993C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the 7994file or pipe again to the caller. 7995 7996=cut 7997 7998sub LineInfo { 7999 if (@_) { 8000 $lineinfo = shift; 8001 8002 # If this is a valid "thing to be opened for output", tack a 8003 # '>' onto the front. 8004 my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo"; 8005 8006 # If this is a pipe, the stream points to a client editor. 8007 $client_editor = ( $stream =~ /^\|/ ); 8008 8009 my $new_lineinfo_fh; 8010 # Open it up and unbuffer it. 8011 open ($new_lineinfo_fh , $stream ) 8012 or _db_warn("Cannot open '$stream' for write"); 8013 $LINEINFO = $new_lineinfo_fh; 8014 _autoflush($LINEINFO); 8015 } 8016 8017 return $lineinfo; 8018} ## end sub LineInfo 8019 8020=head1 COMMAND SUPPORT ROUTINES 8021 8022These subroutines provide functionality for various commands. 8023 8024=head2 C<list_modules> 8025 8026For the C<M> command: list modules loaded and their versions. 8027Essentially just runs through the keys in %INC, picks each package's 8028C<$VERSION> variable, gets the file name, and formats the information 8029for output. 8030 8031=cut 8032 8033sub list_modules { # versions 8034 my %version; 8035 my $file; 8036 8037 # keys are the "as-loaded" name, values are the fully-qualified path 8038 # to the file itself. 8039 for ( keys %INC ) { 8040 $file = $_; # get the module name 8041 s,\.p[lm]$,,i; # remove '.pl' or '.pm' 8042 s,/,::,g; # change '/' to '::' 8043 s/^perl5db$/DB/; # Special case: debugger 8044 # moves to package DB 8045 s/^Term::ReadLine::readline$/readline/; # simplify readline 8046 8047 # If the package has a $VERSION package global (as all good packages 8048 # should!) decode it and save as partial message. 8049 my $pkg_version = do { no strict 'refs'; ${ $_ . '::VERSION' } }; 8050 if ( defined $pkg_version ) { 8051 $version{$file} = "$pkg_version from "; 8052 } 8053 8054 # Finish up the message with the file the package came from. 8055 $version{$file} .= $INC{$file}; 8056 } ## end for (keys %INC) 8057 8058 # Hey, dumpit() formats a hash nicely, so why not use it? 8059 dumpit( $OUT, \%version ); 8060} ## end sub list_modules 8061 8062=head2 C<sethelp()> 8063 8064Sets up the monster string used to format and print the help. 8065 8066=head3 HELP MESSAGE FORMAT 8067 8068The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments> 8069(C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly 8070easy to parse and portable, but which still allows the help to be a little 8071nicer than just plain text. 8072 8073Essentially, you define the command name (usually marked up with C<< B<> >> 8074and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a 8075newline. The descriptive text can also be marked up in the same way. If you 8076need to continue the descriptive text to another line, start that line with 8077just tabs and then enter the marked-up text. 8078 8079If you are modifying the help text, I<be careful>. The help-string parser is 8080not very sophisticated, and if you don't follow these rules it will mangle the 8081help beyond hope until you fix the string. 8082 8083=cut 8084 8085use vars qw($pre580_help); 8086use vars qw($pre580_summary); 8087 8088sub sethelp { 8089 8090 # XXX: make sure there are tabs between the command and explanation, 8091 # or print_help will screw up your formatting if you have 8092 # eeevil ornaments enabled. This is an insane mess. 8093 8094 $help = " 8095Help is currently only available for the new 5.8 command set. 8096No help is available for the old command set. 8097We assume you know what you're doing if you switch to it. 8098 8099B<T> Stack trace. 8100B<s> [I<expr>] Single step [in I<expr>]. 8101B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. 8102<B<CR>> Repeat last B<n> or B<s> command. 8103B<r> Return from current subroutine. 8104B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint 8105 at the specified position. 8106B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. 8107B<l> I<min>B<->I<max> List lines I<min> through I<max>. 8108B<l> I<line> List single I<line>. 8109B<l> I<subname> List first window of lines from subroutine. 8110B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. 8111B<l> List next window of lines. 8112B<-> List previous window of lines. 8113B<v> [I<line>] View window around I<line>. 8114B<.> Return to the executed line. 8115B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. 8116 I<filename> may be either the full name of the file, or a regular 8117 expression matching the full file name: 8118 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. 8119 Evals (with saved bodies) are considered to be filenames: 8120 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval 8121 (in the order of execution). 8122B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. 8123B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. 8124B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions. 8125B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. 8126B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth). 8127B<t> [I<n>] I<expr> Trace through execution of I<expr>. 8128B<b> Sets breakpoint on current line) 8129B<b> [I<line>] [I<condition>] 8130 Set breakpoint; I<line> defaults to the current execution line; 8131 I<condition> breaks if it evaluates to true, defaults to '1'. 8132B<b> I<subname> [I<condition>] 8133 Set breakpoint at first line of subroutine. 8134B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. 8135B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file. 8136B<b> B<postpone> I<subname> [I<condition>] 8137 Set breakpoint at first line of subroutine after 8138 it is compiled. 8139B<b> B<compile> I<subname> 8140 Stop after the subroutine is compiled. 8141B<B> [I<line>] Delete the breakpoint for I<line>. 8142B<B> I<*> Delete all breakpoints. 8143B<a> [I<line>] I<command> 8144 Set an action to be done before the I<line> is executed; 8145 I<line> defaults to the current execution line. 8146 Sequence is: check for breakpoint/watchpoint, print line 8147 if necessary, do action, prompt user if necessary, 8148 execute line. 8149B<a> Does nothing 8150B<A> [I<line>] Delete the action for I<line>. 8151B<A> I<*> Delete all actions. 8152B<w> I<expr> Add a global watch-expression. 8153B<w> Does nothing 8154B<W> I<expr> Delete a global watch-expression. 8155B<W> I<*> Delete all watch-expressions. 8156B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). 8157 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. 8158B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". 8159B<x> I<expr> Evals expression in list context, dumps the result. 8160B<m> I<expr> Evals expression in list context, prints methods callable 8161 on the first element of the result. 8162B<m> I<class> Prints methods callable via the given class. 8163B<M> Show versions of loaded modules. 8164B<i> I<class> Prints nested parents of given class. 8165B<e> Display current thread id. 8166B<E> Display all thread ids the current one will be identified: <n>. 8167B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8168 8169B<<> ? List Perl commands to run before each prompt. 8170B<<> I<expr> Define Perl command to run before each prompt. 8171B<<<> I<expr> Add to the list of Perl commands to run before each prompt. 8172B<< *> Delete the list of perl commands to run before each prompt. 8173B<>> ? List Perl commands to run after each prompt. 8174B<>> I<expr> Define Perl command to run after each prompt. 8175B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. 8176B<>>B< *> Delete the list of Perl commands to run after each prompt. 8177B<{> I<db_command> Define debugger command to run before each prompt. 8178B<{> ? List debugger commands to run before each prompt. 8179B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. 8180B<{ *> Delete the list of debugger commands to run before each prompt. 8181B<$prc> I<number> Redo a previous command (default previous command). 8182B<$prc> I<-number> Redo number'th-to-last command. 8183B<$prc> I<pattern> Redo last command that started with I<pattern>. 8184 See 'B<O> I<recallCommand>' too. 8185B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" 8186 . ( 8187 $rc eq $sh 8188 ? "" 8189 : " 8190B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." 8191 ) . " 8192 See 'B<O> I<shellBang>' too. 8193B<source> I<file> Execute I<file> containing debugger commands (may nest). 8194B<save> I<file> Save current debugger session (actual history) to I<file>. 8195B<rerun> Rerun session to current position. 8196B<rerun> I<n> Rerun session to numbered command. 8197B<rerun> I<-n> Rerun session to number'th-to-last command. 8198B<H> I<-number> Display last number commands (default all). 8199B<H> I<*> Delete complete history. 8200B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. 8201B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. 8202B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarily select()ed as well. 8203B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. 8204I<command> Execute as a perl statement in current package. 8205B<R> Poor man's restart of the debugger, some of debugger state 8206 and command-line options may be lost. 8207 Currently the following settings are preserved: 8208 history, breakpoints and actions, debugger B<O>ptions 8209 and the following command-line options: I<-w>, I<-I>, I<-e>. 8210 8211B<o> [I<opt>] ... Set boolean option to true 8212B<o> [I<opt>B<?>] Query options 8213B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... 8214 Set options. Use quotes if spaces in value. 8215 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; 8216 I<pager> program for output of \"|cmd\"; 8217 I<tkRunning> run Tk while prompting (with ReadLine); 8218 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; 8219 I<inhibit_exit> Allows stepping off the end of the script. 8220 I<ImmediateStop> Debugger should stop as early as possible. 8221 I<RemotePort> Remote hostname:port for remote debugging 8222 The following options affect what happens with B<V>, B<X>, and B<x> commands: 8223 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); 8224 I<compactDump>, I<veryCompact> change style of array and hash dump; 8225 I<globPrint> whether to print contents of globs; 8226 I<DumpDBFiles> dump arrays holding debugged files; 8227 I<DumpPackages> dump symbol tables of packages; 8228 I<DumpReused> dump contents of \"reused\" addresses; 8229 I<quote>, I<HighBit>, I<undefPrint> change style of string dump; 8230 I<bareStringify> Do not print the overload-stringified value; 8231 Other options include: 8232 I<PrintRet> affects printing of return value after B<r> command, 8233 I<frame> affects printing messages on subroutine entry/exit. 8234 I<AutoTrace> affects printing messages on possible breaking points. 8235 I<maxTraceLen> gives max length of evals/args listed in stack trace. 8236 I<ornaments> affects screen appearance of the command line. 8237 I<CreateTTY> bits control attempts to create a new TTY on events: 8238 1: on fork() 2: debugger is started inside debugger 8239 4: on startup 8240 During startup options are initialized from \$ENV{PERLDB_OPTS}. 8241 You can put additional initialization options I<TTY>, I<noTTY>, 8242 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use 8243 B<R> after you set them). 8244 8245B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. 8246B<h> Summary of debugger commands. 8247B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. 8248B<h h> Long help for debugger commands 8249B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the 8250 named Perl I<manpage>, or on B<$doccmd> itself if omitted. 8251 Set B<\$DB::doccmd> to change viewer. 8252 8253Type '|h h' for a paged display if this was too hard to read. 8254 8255"; # Fix balance of vi % matching: }}}} 8256 8257 # note: tabs in the following section are not-so-helpful 8258 $summary = <<"END_SUM"; 8259I<List/search source lines:> I<Control script execution:> 8260 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace 8261 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] 8262 B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs 8263 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> 8264 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine 8265 B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position 8266I<Debugger controls:> B<L> List break/watch/actions 8267 B<o> [...] Set debugger options B<t> [I<n>] [I<expr>] Toggle trace [max depth] ][trace expr] 8268 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint 8269 B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints 8270 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line 8271 B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions 8272 B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression 8273 B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs 8274 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess 8275 B<q> or B<^D> Quit B<R> Attempt a restart 8276I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> 8277 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. 8278 B<p> I<expr> Print expression (uses script's current package). 8279 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern 8280 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. 8281 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree. 8282 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8283 B<e> Display thread id B<E> Display all thread ids. 8284For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. 8285END_SUM 8286 8287 # ')}}; # Fix balance of vi % matching 8288 8289 # and this is really numb... 8290 $pre580_help = " 8291B<T> Stack trace. 8292B<s> [I<expr>] Single step [in I<expr>]. 8293B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. 8294B<CR>> Repeat last B<n> or B<s> command. 8295B<r> Return from current subroutine. 8296B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint 8297 at the specified position. 8298B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. 8299B<l> I<min>B<->I<max> List lines I<min> through I<max>. 8300B<l> I<line> List single I<line>. 8301B<l> I<subname> List first window of lines from subroutine. 8302B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. 8303B<l> List next window of lines. 8304B<-> List previous window of lines. 8305B<w> [I<line>] List window around I<line>. 8306B<.> Return to the executed line. 8307B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. 8308 I<filename> may be either the full name of the file, or a regular 8309 expression matching the full file name: 8310 B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. 8311 Evals (with saved bodies) are considered to be filenames: 8312 B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval 8313 (in the order of execution). 8314B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. 8315B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. 8316B<L> List all breakpoints and actions. 8317B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. 8318B<t> [I<n>] Toggle trace mode (to max I<n> levels below current stack depth) . 8319B<t> [I<n>] I<expr> Trace through execution of I<expr>. 8320B<b> [I<line>] [I<condition>] 8321 Set breakpoint; I<line> defaults to the current execution line; 8322 I<condition> breaks if it evaluates to true, defaults to '1'. 8323B<b> I<subname> [I<condition>] 8324 Set breakpoint at first line of subroutine. 8325B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. 8326B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file. 8327B<b> B<postpone> I<subname> [I<condition>] 8328 Set breakpoint at first line of subroutine after 8329 it is compiled. 8330B<b> B<compile> I<subname> 8331 Stop after the subroutine is compiled. 8332B<d> [I<line>] Delete the breakpoint for I<line>. 8333B<D> Delete all breakpoints. 8334B<a> [I<line>] I<command> 8335 Set an action to be done before the I<line> is executed; 8336 I<line> defaults to the current execution line. 8337 Sequence is: check for breakpoint/watchpoint, print line 8338 if necessary, do action, prompt user if necessary, 8339 execute line. 8340B<a> [I<line>] Delete the action for I<line>. 8341B<A> Delete all actions. 8342B<W> I<expr> Add a global watch-expression. 8343B<W> Delete all watch-expressions. 8344B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). 8345 Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. 8346B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". 8347B<x> I<expr> Evals expression in list context, dumps the result. 8348B<m> I<expr> Evals expression in list context, prints methods callable 8349 on the first element of the result. 8350B<m> I<class> Prints methods callable via the given class. 8351 8352B<<> ? List Perl commands to run before each prompt. 8353B<<> I<expr> Define Perl command to run before each prompt. 8354B<<<> I<expr> Add to the list of Perl commands to run before each prompt. 8355B<>> ? List Perl commands to run after each prompt. 8356B<>> I<expr> Define Perl command to run after each prompt. 8357B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. 8358B<{> I<db_command> Define debugger command to run before each prompt. 8359B<{> ? List debugger commands to run before each prompt. 8360B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. 8361B<$prc> I<number> Redo a previous command (default previous command). 8362B<$prc> I<-number> Redo number'th-to-last command. 8363B<$prc> I<pattern> Redo last command that started with I<pattern>. 8364 See 'B<O> I<recallCommand>' too. 8365B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" 8366 . ( 8367 $rc eq $sh 8368 ? "" 8369 : " 8370B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." 8371 ) . " 8372 See 'B<O> I<shellBang>' too. 8373B<source> I<file> Execute I<file> containing debugger commands (may nest). 8374B<H> I<-number> Display last number commands (default all). 8375B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. 8376B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. 8377B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well. 8378B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. 8379I<command> Execute as a perl statement in current package. 8380B<v> Show versions of loaded modules. 8381B<R> Poor man's restart of the debugger, some of debugger state 8382 and command-line options may be lost. 8383 Currently the following settings are preserved: 8384 history, breakpoints and actions, debugger B<O>ptions 8385 and the following command-line options: I<-w>, I<-I>, I<-e>. 8386 8387B<O> [I<opt>] ... Set boolean option to true 8388B<O> [I<opt>B<?>] Query options 8389B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... 8390 Set options. Use quotes if spaces in value. 8391 I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; 8392 I<pager> program for output of \"|cmd\"; 8393 I<tkRunning> run Tk while prompting (with ReadLine); 8394 I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; 8395 I<inhibit_exit> Allows stepping off the end of the script. 8396 I<ImmediateStop> Debugger should stop as early as possible. 8397 I<RemotePort> Remote hostname:port for remote debugging 8398 The following options affect what happens with B<V>, B<X>, and B<x> commands: 8399 I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); 8400 I<compactDump>, I<veryCompact> change style of array and hash dump; 8401 I<globPrint> whether to print contents of globs; 8402 I<DumpDBFiles> dump arrays holding debugged files; 8403 I<DumpPackages> dump symbol tables of packages; 8404 I<DumpReused> dump contents of \"reused\" addresses; 8405 I<quote>, I<HighBit>, I<undefPrint> change style of string dump; 8406 I<bareStringify> Do not print the overload-stringified value; 8407 Other options include: 8408 I<PrintRet> affects printing of return value after B<r> command, 8409 I<frame> affects printing messages on subroutine entry/exit. 8410 I<AutoTrace> affects printing messages on possible breaking points. 8411 I<maxTraceLen> gives max length of evals/args listed in stack trace. 8412 I<ornaments> affects screen appearance of the command line. 8413 I<CreateTTY> bits control attempts to create a new TTY on events: 8414 1: on fork() 2: debugger is started inside debugger 8415 4: on startup 8416 During startup options are initialized from \$ENV{PERLDB_OPTS}. 8417 You can put additional initialization options I<TTY>, I<noTTY>, 8418 I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use 8419 B<R> after you set them). 8420 8421B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. 8422B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. 8423B<h h> Summary of debugger commands. 8424B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the 8425 named Perl I<manpage>, or on B<$doccmd> itself if omitted. 8426 Set B<\$DB::doccmd> to change viewer. 8427 8428Type '|h' for a paged display if this was too hard to read. 8429 8430"; # Fix balance of vi % matching: }}}} 8431 8432 # note: tabs in the following section are not-so-helpful 8433 $pre580_summary = <<"END_SUM"; 8434I<List/search source lines:> I<Control script execution:> 8435 B<l> [I<ln>|I<sub>] List source code B<T> Stack trace 8436 B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] 8437 B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs 8438 B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> 8439 B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine 8440 B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position 8441I<Debugger controls:> B<L> List break/watch/actions 8442 B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr] 8443 B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint 8444 B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints 8445 B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line 8446 B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression 8447 B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch 8448 B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess 8449 B<q> or B<^D> Quit B<R> Attempt a restart 8450I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> 8451 B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. 8452 B<p> I<expr> Print expression (uses script's current package). 8453 B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern 8454 B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. 8455 B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". 8456 B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. 8457For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. 8458END_SUM 8459 8460 # ')}}; # Fix balance of vi % matching 8461 8462} ## end sub sethelp 8463 8464=head2 C<print_help()> 8465 8466Most of what C<print_help> does is just text formatting. It finds the 8467C<B> and C<I> ornaments, cleans them off, and substitutes the proper 8468terminal control characters to simulate them (courtesy of 8469C<Term::ReadLine::TermCap>). 8470 8471=cut 8472 8473sub print_help { 8474 my $help_str = shift; 8475 8476 # Restore proper alignment destroyed by eeevil I<> and B<> 8477 # ornaments: A pox on both their houses! 8478 # 8479 # A help command will have everything up to and including 8480 # the first tab sequence padded into a field 16 (or if indented 20) 8481 # wide. If it's wider than that, an extra space will be added. 8482 $help_str =~ s{ 8483 ^ # only matters at start of line 8484 ( \ {4} | \t )* # some subcommands are indented 8485 ( < ? # so <CR> works 8486 [BI] < [^\t\n] + ) # find an eeevil ornament 8487 ( \t+ ) # original separation, discarded 8488 ( .* ) # this will now start (no earlier) than 8489 # column 16 8490 } { 8491 my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4); 8492 my $clean = $command; 8493 $clean =~ s/[BI]<([^>]*)>/$1/g; 8494 8495 # replace with this whole string: 8496 ($leadwhite ? " " x 4 : "") 8497 . $command 8498 . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ") 8499 . $text; 8500 8501 }mgex; 8502 8503 $help_str =~ s{ # handle bold ornaments 8504 B < ( [^>] + | > ) > 8505 } { 8506 $Term::ReadLine::TermCap::rl_term_set[2] 8507 . $1 8508 . $Term::ReadLine::TermCap::rl_term_set[3] 8509 }gex; 8510 8511 $help_str =~ s{ # handle italic ornaments 8512 I < ( [^>] + | > ) > 8513 } { 8514 $Term::ReadLine::TermCap::rl_term_set[0] 8515 . $1 8516 . $Term::ReadLine::TermCap::rl_term_set[1] 8517 }gex; 8518 8519 local $\ = ''; 8520 print {$OUT} $help_str; 8521 8522 return; 8523} ## end sub print_help 8524 8525=head2 C<fix_less> 8526 8527This routine does a lot of gyrations to be sure that the pager is C<less>. 8528It checks for C<less> masquerading as C<more> and records the result in 8529C<$fixed_less> so we don't have to go through doing the stats again. 8530 8531=cut 8532 8533use vars qw($fixed_less); 8534 8535sub _calc_is_less { 8536 if ($pager =~ /\bless\b/) 8537 { 8538 return 1; 8539 } 8540 elsif ($pager =~ /\bmore\b/) 8541 { 8542 # Nope, set to more. See what's out there. 8543 my @st_more = stat('/usr/bin/more'); 8544 my @st_less = stat('/usr/bin/less'); 8545 8546 # is it really less, pretending to be more? 8547 return ( 8548 @st_more 8549 && @st_less 8550 && $st_more[0] == $st_less[0] 8551 && $st_more[1] == $st_less[1] 8552 ); 8553 } 8554 else { 8555 return; 8556 } 8557} 8558 8559sub fix_less { 8560 8561 # We already know if this is set. 8562 return if $fixed_less; 8563 8564 # changes environment! 8565 # 'r' added so we don't do (slow) stats again. 8566 $fixed_less = 1 if _calc_is_less(); 8567 8568 return; 8569} ## end sub fix_less 8570 8571=head1 DIE AND WARN MANAGEMENT 8572 8573=head2 C<diesignal> 8574 8575C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying 8576to debug a debugger problem. 8577 8578It does its best to report the error that occurred, and then forces the 8579program, debugger, and everything to die. 8580 8581=cut 8582 8583sub diesignal { 8584 8585 # No entry/exit messages. 8586 local $frame = 0; 8587 8588 # No return value prints. 8589 local $doret = -2; 8590 8591 # set the abort signal handling to the default (just terminate). 8592 $SIG{'ABRT'} = 'DEFAULT'; 8593 8594 # If we enter the signal handler recursively, kill myself with an 8595 # abort signal (so we just terminate). 8596 kill 'ABRT', $$ if $panic++; 8597 8598 # If we can show detailed info, do so. 8599 if ( defined &Carp::longmess ) { 8600 8601 # Don't recursively enter the warn handler, since we're carping. 8602 local $SIG{__WARN__} = ''; 8603 8604 # Skip two levels before reporting traceback: we're skipping 8605 # mydie and confess. 8606 local $Carp::CarpLevel = 2; # mydie + confess 8607 8608 # Tell us all about it. 8609 _db_warn( Carp::longmess("Signal @_") ); 8610 } 8611 8612 # No Carp. Tell us about the signal as best we can. 8613 else { 8614 local $\ = ''; 8615 print $DB::OUT "Got signal @_\n"; 8616 } 8617 8618 # Drop dead. 8619 kill 'ABRT', $$; 8620} ## end sub diesignal 8621 8622=head2 C<dbwarn> 8623 8624The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to 8625be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>. 8626 8627=cut 8628 8629sub dbwarn { 8630 8631 # No entry/exit trace. 8632 local $frame = 0; 8633 8634 # No return value printing. 8635 local $doret = -2; 8636 8637 # Turn off warn and die handling to prevent recursive entries to this 8638 # routine. 8639 local $SIG{__WARN__} = ''; 8640 local $SIG{__DIE__} = ''; 8641 8642 # Load Carp if we can. If $^S is false (current thing being compiled isn't 8643 # done yet), we may not be able to do a require. 8644 eval { require Carp } 8645 if defined $^S; # If error/warning during compilation, 8646 # require may be broken. 8647 8648 # Use the core warn() unless Carp loaded OK. 8649 CORE::warn( @_, 8650 "\nCannot print stack trace, load with -MCarp option to see stack" ), 8651 return 8652 unless defined &Carp::longmess; 8653 8654 # Save the current values of $single and $trace, and then turn them off. 8655 my ( $mysingle, $mytrace ) = ( $single, $trace ); 8656 $single = 0; 8657 $trace = 0; 8658 8659 # We can call Carp::longmess without its being "debugged" (which we 8660 # don't want - we just want to use it!). Capture this for later. 8661 my $mess = Carp::longmess(@_); 8662 8663 # Restore $single and $trace to their original values. 8664 ( $single, $trace ) = ( $mysingle, $mytrace ); 8665 8666 # Use the debugger's own special way of printing warnings to print 8667 # the stack trace message. 8668 _db_warn($mess); 8669} ## end sub dbwarn 8670 8671=head2 C<dbdie> 8672 8673The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace 8674by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off 8675single stepping and tracing during the call to C<Carp::longmess> to avoid 8676debugging it - we just want to use it. 8677 8678If C<dieLevel> is zero, we let the program being debugged handle the 8679exceptions. If it's 1, you get backtraces for any exception. If it's 2, 8680the debugger takes over all exception handling, printing a backtrace and 8681displaying the exception via its C<dbwarn()> routine. 8682 8683=cut 8684 8685sub dbdie { 8686 local $frame = 0; 8687 local $doret = -2; 8688 local $SIG{__DIE__} = ''; 8689 local $SIG{__WARN__} = ''; 8690 if ( $dieLevel > 2 ) { 8691 local $SIG{__WARN__} = \&dbwarn; 8692 _db_warn(@_); # Yell no matter what 8693 return; 8694 } 8695 if ( $dieLevel < 2 ) { 8696 die @_ if $^S; # in eval propagate 8697 } 8698 8699 # The code used to check $^S to see if compilation of the current thing 8700 # hadn't finished. We don't do it anymore, figuring eval is pretty stable. 8701 eval { require Carp }; 8702 8703 die( @_, 8704 "\nCannot print stack trace, load with -MCarp option to see stack" ) 8705 unless defined &Carp::longmess; 8706 8707 # We do not want to debug this chunk (automatic disabling works 8708 # inside DB::DB, but not in Carp). Save $single and $trace, turn them off, 8709 # get the stack trace from Carp::longmess (if possible), restore $signal 8710 # and $trace, and then die with the stack trace. 8711 my ( $mysingle, $mytrace ) = ( $single, $trace ); 8712 $single = 0; 8713 $trace = 0; 8714 my $mess = "@_"; 8715 { 8716 8717 package Carp; # Do not include us in the list 8718 eval { $mess = Carp::longmess(@_); }; 8719 } 8720 ( $single, $trace ) = ( $mysingle, $mytrace ); 8721 die $mess; 8722} ## end sub dbdie 8723 8724=head2 C<warnlevel()> 8725 8726Set the C<$DB::warnLevel> variable that stores the value of the 8727C<warnLevel> option. Calling C<warnLevel()> with a positive value 8728results in the debugger taking over all warning handlers. Setting 8729C<warnLevel> to zero leaves any warning handlers set up by the program 8730being debugged in place. 8731 8732=cut 8733 8734sub warnLevel { 8735 if (@_) { 8736 my $prevwarn = $SIG{__WARN__} unless $warnLevel; 8737 $warnLevel = shift; 8738 if ($warnLevel) { 8739 $SIG{__WARN__} = \&DB::dbwarn; 8740 } 8741 elsif ($prevwarn) { 8742 $SIG{__WARN__} = $prevwarn; 8743 } else { 8744 undef $SIG{__WARN__}; 8745 } 8746 } ## end if (@_) 8747 $warnLevel; 8748} ## end sub warnLevel 8749 8750=head2 C<dielevel> 8751 8752Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the 8753C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to 8754zero lets you use your own C<die()> handler. 8755 8756=cut 8757 8758sub dieLevel { 8759 local $\ = ''; 8760 if (@_) { 8761 my $prevdie = $SIG{__DIE__} unless $dieLevel; 8762 $dieLevel = shift; 8763 if ($dieLevel) { 8764 8765 # Always set it to dbdie() for non-zero values. 8766 $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2; 8767 8768 # No longer exists, so don't try to use it. 8769 #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2; 8770 8771 # If we've finished initialization, mention that stack dumps 8772 # are enabled, If dieLevel is 1, we won't stack dump if we die 8773 # in an eval(). 8774 print $OUT "Stack dump during die enabled", 8775 ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n" 8776 if $I_m_init; 8777 8778 # XXX This is probably obsolete, given that diehard() is gone. 8779 print $OUT "Dump printed too.\n" if $dieLevel > 2; 8780 } ## end if ($dieLevel) 8781 8782 # Put the old one back if there was one. 8783 elsif ($prevdie) { 8784 $SIG{__DIE__} = $prevdie; 8785 print $OUT "Default die handler restored.\n"; 8786 } else { 8787 undef $SIG{__DIE__}; 8788 print $OUT "Die handler removed.\n"; 8789 } 8790 } ## end if (@_) 8791 $dieLevel; 8792} ## end sub dieLevel 8793 8794=head2 C<signalLevel> 8795 8796Number three in a series: set C<signalLevel> to zero to keep your own 8797signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger 8798takes over and handles them with C<DB::diesignal()>. 8799 8800=cut 8801 8802sub signalLevel { 8803 if (@_) { 8804 my $prevsegv = $SIG{SEGV} unless $signalLevel; 8805 my $prevbus = $SIG{BUS} unless $signalLevel; 8806 $signalLevel = shift; 8807 if ($signalLevel) { 8808 $SIG{SEGV} = \&DB::diesignal; 8809 $SIG{BUS} = \&DB::diesignal; 8810 } 8811 else { 8812 $SIG{SEGV} = $prevsegv; 8813 $SIG{BUS} = $prevbus; 8814 } 8815 } ## end if (@_) 8816 $signalLevel; 8817} ## end sub signalLevel 8818 8819=head1 SUBROUTINE DECODING SUPPORT 8820 8821These subroutines are used during the C<x> and C<X> commands to try to 8822produce as much information as possible about a code reference. They use 8823L<Devel::Peek> to try to find the glob in which this code reference lives 8824(if it does) - this allows us to actually code references which correspond 8825to named subroutines (including those aliased via glob assignment). 8826 8827=head2 C<CvGV_name()> 8828 8829Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference 8830via that routine. If this fails, return the reference again (when the 8831reference is stringified, it'll come out as C<SOMETHING(0x...)>). 8832 8833=cut 8834 8835sub CvGV_name { 8836 my $in = shift; 8837 my $name = CvGV_name_or_bust($in); 8838 defined $name ? $name : $in; 8839} 8840 8841=head2 C<CvGV_name_or_bust> I<coderef> 8842 8843Calls L<Devel::Peek> to try to find the glob the ref lives in; returns 8844C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't 8845find a glob for this ref. 8846 8847Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob. 8848 8849=cut 8850 8851use vars qw($skipCvGV); 8852 8853sub CvGV_name_or_bust { 8854 my $in = shift; 8855 return if $skipCvGV; # Backdoor to avoid problems if XS broken... 8856 return unless ref $in; 8857 $in = \&$in; # Hard reference... 8858 eval { _DB__use_full_path(sub { require Devel::Peek; 1; }); } or return; 8859 my $gv = Devel::Peek::CvGV($in) or return; 8860 *$gv{PACKAGE} . '::' . *$gv{NAME}; 8861} ## end sub CvGV_name_or_bust 8862 8863=head2 C<find_sub> 8864 8865A utility routine used in various places; finds the file where a subroutine 8866was defined, and returns that filename and a line-number range. 8867 8868Tries to use C<@sub> first; if it can't find it there, it tries building a 8869reference to the subroutine and uses C<CvGV_name_or_bust> to locate it, 8870loading it into C<@sub> as a side effect (XXX I think). If it can't find it 8871this way, it brute-force searches C<%sub>, checking for identical references. 8872 8873=cut 8874 8875sub _find_sub_helper { 8876 my $subr = shift; 8877 8878 return unless defined &$subr; 8879 my $name = CvGV_name_or_bust($subr); 8880 my $data; 8881 $data = $sub{$name} if defined $name; 8882 return $data if defined $data; 8883 8884 # Old stupid way... 8885 $subr = \&$subr; # Hard reference 8886 my $s; 8887 for ( keys %sub ) { 8888 $s = $_, last if $subr eq \&$_; 8889 } 8890 if ($s) 8891 { 8892 return $sub{$s}; 8893 } 8894 else 8895 { 8896 return; 8897 } 8898 8899} 8900 8901sub find_sub { 8902 my $subr = shift; 8903 return ( $sub{$subr} || _find_sub_helper($subr) ); 8904} ## end sub find_sub 8905 8906=head2 C<methods> 8907 8908A subroutine that uses the utility function C<methods_via> to find all the 8909methods in the class corresponding to the current reference and in 8910C<UNIVERSAL>. 8911 8912=cut 8913 8914use vars qw(%seen); 8915 8916sub methods { 8917 8918 # Figure out the class - either this is the class or it's a reference 8919 # to something blessed into that class. 8920 my $class = shift; 8921 $class = ref $class if ref $class; 8922 8923 local %seen; 8924 8925 # Show the methods that this class has. 8926 methods_via( $class, '', 1 ); 8927 8928 # Show the methods that UNIVERSAL has. 8929 methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 ); 8930} ## end sub methods 8931 8932=head2 C<methods_via($class, $prefix, $crawl_upward)> 8933 8934C<methods_via> does the work of crawling up the C<@ISA> tree and reporting 8935all the parent class methods. C<$class> is the name of the next class to 8936try; C<$prefix> is the message prefix, which gets built up as we go up the 8937C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go 8938higher in the C<@ISA> tree, 0 if we should stop. 8939 8940=cut 8941 8942sub methods_via { 8943 8944 # If we've processed this class already, just quit. 8945 my $class = shift; 8946 return if $seen{$class}++; 8947 8948 # This is a package that is contributing the methods we're about to print. 8949 my $prefix = shift; 8950 my $prepend = $prefix ? "via $prefix: " : ''; 8951 my @to_print; 8952 8953 # Extract from all the symbols in this class. 8954 my $class_ref = do { no strict "refs"; \%{$class . '::'} }; 8955 while (my ($name, $glob) = each %$class_ref) { 8956 # references directly in the symbol table are Proxy Constant 8957 # Subroutines, and are by their very nature defined 8958 # Otherwise, check if the thing is a typeglob, and if it is, it decays 8959 # to a subroutine reference, which can be tested by defined. 8960 # $glob might also be the value -1 (from sub foo;) 8961 # or (say) '$$' (from sub foo ($$);) 8962 # \$glob will be SCALAR in both cases. 8963 if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob)) 8964 && !$seen{$name}++) { 8965 push @to_print, "$prepend$name\n"; 8966 } 8967 } 8968 8969 { 8970 local $\ = ''; 8971 local $, = ''; 8972 print $DB::OUT $_ foreach sort @to_print; 8973 } 8974 8975 # If the $crawl_upward argument is false, just quit here. 8976 return unless shift; 8977 8978 # $crawl_upward true: keep going up the tree. 8979 # Find all the classes this one is a subclass of. 8980 my $class_ISA_ref = do { no strict "refs"; \@{"${class}::ISA"} }; 8981 for my $name ( @$class_ISA_ref ) { 8982 8983 # Set up the new prefix. 8984 $prepend = $prefix ? $prefix . " -> $name" : $name; 8985 8986 # Crawl up the tree and keep trying to crawl up. 8987 methods_via( $name, $prepend, 1 ); 8988 } 8989} ## end sub methods_via 8990 8991=head2 C<setman> - figure out which command to use to show documentation 8992 8993Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly. 8994 8995=cut 8996 8997sub setman { 8998 $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|amigaos|riscos)\z/s 8999 ? "man" # O Happy Day! 9000 : "perldoc"; # Alas, poor unfortunates 9001} ## end sub setman 9002 9003=head2 C<runman> - run the appropriate command to show documentation 9004 9005Accepts a man page name; runs the appropriate command to display it (set up 9006during debugger initialization). Uses C<_db_system()> to avoid mucking up the 9007program's STDIN and STDOUT. 9008 9009=cut 9010 9011sub runman { 9012 my $page = shift; 9013 unless ($page) { 9014 _db_system("$doccmd $doccmd"); 9015 return; 9016 } 9017 9018 # this way user can override, like with $doccmd="man -Mwhatever" 9019 # or even just "man " to disable the path check. 9020 if ( $doccmd ne 'man' ) { 9021 _db_system("$doccmd $page"); 9022 return; 9023 } 9024 9025 $page = 'perl' if lc($page) eq 'help'; 9026 9027 require Config; 9028 my $man1dir = $Config::Config{man1direxp}; 9029 my $man3dir = $Config::Config{man3direxp}; 9030 for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ } 9031 my $manpath = ''; 9032 $manpath .= "$man1dir:" if $man1dir =~ /\S/; 9033 $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir; 9034 chop $manpath if $manpath; 9035 9036 # harmless if missing, I figure 9037 local $ENV{MANPATH} = $manpath if $manpath; 9038 my $nopathopt = $^O =~ /dunno what goes here/; 9039 if ( 9040 CORE::system( 9041 $doccmd, 9042 9043 # I just *know* there are men without -M 9044 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), 9045 split ' ', $page 9046 ) 9047 ) 9048 { 9049 unless ( $page =~ /^perl\w/ ) { 9050 # Previously the debugger contained a list which it slurped in, 9051 # listing the known "perl" manpages. However, it was out of date, 9052 # with errors both of omission and inclusion. This approach is 9053 # considerably less complex. The failure mode on a butchered 9054 # install is simply that the user has to run man or perldoc 9055 # "manually" with the full manpage name. 9056 9057 # There is a list of $^O values in installperl to determine whether 9058 # the directory is 'pods' or 'pod'. However, we can avoid tight 9059 # coupling to that by simply checking the "non-standard" 'pods' 9060 # first. 9061 my $pods = "$Config::Config{privlibexp}/pods"; 9062 $pods = "$Config::Config{privlibexp}/pod" 9063 unless -d $pods; 9064 if (-f "$pods/perl$page.pod") { 9065 CORE::system( $doccmd, 9066 ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), 9067 "perl$page" ); 9068 } 9069 } 9070 } ## end if (CORE::system($doccmd... 9071} ## end sub runman 9072 9073#use Carp; # This did break, left for debugging 9074 9075=head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK 9076 9077Because of the way the debugger interface to the Perl core is designed, any 9078debugger package globals that C<DB::sub()> requires have to be defined before 9079any subroutines can be called. These are defined in the second C<BEGIN> block. 9080 9081This block sets things up so that (basically) the world is sane 9082before the debugger starts executing. We set up various variables that the 9083debugger has to have set up before the Perl core starts running: 9084 9085=over 4 9086 9087=item * 9088 9089The debugger's own filehandles (copies of STD and STDOUT for now). 9090 9091=item * 9092 9093Characters for shell escapes, the recall command, and the history command. 9094 9095=item * 9096 9097The maximum recursion depth. 9098 9099=item * 9100 9101The size of a C<w> command's window. 9102 9103=item * 9104 9105The before-this-line context to be printed in a C<v> (view a window around this line) command. 9106 9107=item * 9108 9109The fact that we're not in a sub at all right now. 9110 9111=item * 9112 9113The default SIGINT handler for the debugger. 9114 9115=item * 9116 9117The appropriate value of the flag in C<$^D> that says the debugger is running 9118 9119=item * 9120 9121The current debugger recursion level 9122 9123=item * 9124 9125The list of postponed items and the C<$single> stack (XXX define this) 9126 9127=item * 9128 9129That we want no return values and no subroutine entry/exit trace. 9130 9131=back 9132 9133=cut 9134 9135# The following BEGIN is very handy if debugger goes havoc, debugging debugger? 9136 9137use vars qw($db_stop); 9138 9139BEGIN { # This does not compile, alas. (XXX eh?) 9140 $IN = \*STDIN; # For bugs before DB::OUT has been opened 9141 $OUT = \*STDERR; # For errors before DB::OUT has been opened 9142 9143 # Define characters used by command parsing. 9144 $sh = '!'; # Shell escape (does not work) 9145 $rc = ','; # Recall command (does not work) 9146 @hist = ('?'); # Show history (does not work) 9147 @truehist = (); # Can be saved for replay (per session) 9148 9149 # This defines the point at which you get the 'deep recursion' 9150 # warning. It MUST be defined or the debugger will not load. 9151 $deep = 1000; 9152 9153 # Number of lines around the current one that are shown in the 9154 # 'w' command. 9155 $window = 10; 9156 9157 # How much before-the-current-line context the 'v' command should 9158 # use in calculating the start of the window it will display. 9159 $preview = 3; 9160 9161 # We're not in any sub yet, but we need this to be a defined value. 9162 $sub = ''; 9163 9164 # Set up the debugger's interrupt handler. It simply sets a flag 9165 # ($signal) that DB::DB() will check before each command is executed. 9166 $SIG{INT} = \&DB::catch; 9167 9168 # The following lines supposedly, if uncommented, allow the debugger to 9169 # debug itself. Perhaps we can try that someday. 9170 # This may be enabled to debug debugger: 9171 #$warnLevel = 1 unless defined $warnLevel; 9172 #$dieLevel = 1 unless defined $dieLevel; 9173 #$signalLevel = 1 unless defined $signalLevel; 9174 9175 # This is the flag that says "a debugger is running, please call 9176 # DB::DB and DB::sub". We will turn it on forcibly before we try to 9177 # execute anything in the user's context, because we always want to 9178 # get control back. 9179 $db_stop = 0; # Compiler warning ... 9180 $db_stop = 1 << 30; # ... because this is only used in an eval() later. 9181 9182 # This variable records how many levels we're nested in debugging. 9183 # Used in the debugger prompt, and in determining whether it's all over or 9184 # not. 9185 $level = 0; # Level of recursive debugging 9186 9187 # "Triggers bug (?) in perl if we postpone this until runtime." 9188 # XXX No details on this yet, or whether we should fix the bug instead 9189 # of work around it. Stay tuned. 9190 @stack = (0); 9191 9192 # Used to track the current stack depth using the auto-stacked-variable 9193 # trick. 9194 $stack_depth = 0; # Localized repeatedly; simple way to track $#stack 9195 9196 # Don't print return values on exiting a subroutine. 9197 $doret = -2; 9198 9199 # No extry/exit tracing. 9200 $frame = 0; 9201 9202} ## end BEGIN 9203 9204BEGIN { $^W = $ini_warn; } # Switch warnings back 9205 9206=head1 READLINE SUPPORT - COMPLETION FUNCTION 9207 9208=head2 db_complete 9209 9210C<readline> support - adds command completion to basic C<readline>. 9211 9212Returns a list of possible completions to C<readline> when invoked. C<readline> 9213will print the longest common substring following the text already entered. 9214 9215If there is only a single possible completion, C<readline> will use it in full. 9216 9217This code uses C<map> and C<grep> heavily to create lists of possible 9218completion. Think LISP in this section. 9219 9220=cut 9221 9222sub db_complete { 9223 9224 # Specific code for b c l V m f O, &blah, $blah, @blah, %blah 9225 # $text is the text to be completed. 9226 # $line is the incoming line typed by the user. 9227 # $start is the start of the text to be completed in the incoming line. 9228 my ( $text, $line, $start ) = @_; 9229 9230 # Save the initial text. 9231 # The search pattern is current package, ::, extract the next qualifier 9232 # Prefix and pack are set to undef. 9233 my ( $itext, $search, $prefix, $pack ) = 9234 ( $text, "^\Q${package}::\E([^:]+)\$" ); 9235 9236=head3 C<b postpone|compile> 9237 9238=over 4 9239 9240=item * 9241 9242Find all the subroutines that might match in this package 9243 9244=item * 9245 9246Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself) 9247 9248=item * 9249 9250Include all the rest of the subs that are known 9251 9252=item * 9253 9254C<grep> out the ones that match the text we have so far 9255 9256=item * 9257 9258Return this as the list of possible completions 9259 9260=back 9261 9262=cut 9263 9264 return sort grep /^\Q$text/, ( keys %sub ), 9265 qw(postpone load compile), # subroutines 9266 ( map { /$search/ ? ($1) : () } keys %sub ) 9267 if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/; 9268 9269=head3 C<b load> 9270 9271Get all the possible files from C<@INC> as it currently stands and 9272select the ones that match the text so far. 9273 9274=cut 9275 9276 return sort grep /^\Q$text/, values %INC # files 9277 if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/; 9278 9279=head3 C<V> (list variable) and C<m> (list modules) 9280 9281There are two entry points for these commands: 9282 9283=head4 Unqualified package names 9284 9285Get the top-level packages and grab everything that matches the text 9286so far. For each match, recursively complete the partial packages to 9287get all possible matching packages. Return this sorted list. 9288 9289=cut 9290 9291 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } 9292 grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages 9293 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/; 9294 9295=head4 Qualified package names 9296 9297Take a partially-qualified package and find all subpackages for it 9298by getting all the subpackages for the package so far, matching all 9299the subpackages against the text, and discarding all of them which 9300start with 'main::'. Return this list. 9301 9302=cut 9303 9304 return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } 9305 grep !/^main::/, grep /^\Q$text/, 9306 map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } 9307 do { no strict 'refs'; keys %{ $prefix . '::' } } 9308 if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ 9309 and $text =~ /^(.*[^:])::?(\w*)$/ 9310 and $prefix = $1; 9311 9312=head3 C<f> - switch files 9313 9314Here, we want to get a fully-qualified filename for the C<f> command. 9315Possibilities are: 9316 9317=over 4 9318 9319=item 1. The original source file itself 9320 9321=item 2. A file from C<@INC> 9322 9323=item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>). 9324 9325=back 9326 9327=cut 9328 9329 if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files 9330 # We might possibly want to switch to an eval (which has a "filename" 9331 # like '(eval 9)'), so we may need to clean up the completion text 9332 # before proceeding. 9333 $prefix = length($1) - length($text); 9334 $text = $1; 9335 9336=pod 9337 9338Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file> 9339(C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these 9340out of C<%main::>, add the initial source file, and extract the ones that 9341match the completion text so far. 9342 9343=cut 9344 9345 return sort 9346 map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ), 9347 $0; 9348 } ## end if ($line =~ /^\|*f\s+(.*)/) 9349 9350=head3 Subroutine name completion 9351 9352We look through all of the defined subs (the keys of C<%sub>) and 9353return both all the possible matches to the subroutine name plus 9354all the matches qualified to the current package. 9355 9356=cut 9357 9358 if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines 9359 $text = substr $text, 1; 9360 $prefix = "&"; 9361 return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ), 9362 ( 9363 map { /$search/ ? ($1) : () } 9364 keys %sub 9365 ); 9366 } ## end if ((substr $text, 0, ... 9367 9368=head3 Scalar, array, and hash completion: partially qualified package 9369 9370Much like the above, except we have to do a little more cleanup: 9371 9372=cut 9373 9374 if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package 9375 9376=pod 9377 9378=over 4 9379 9380=item * 9381 9382Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified. 9383 9384=cut 9385 9386 $pack = ( $1 eq 'main' ? '' : $1 ) . '::'; 9387 9388=pod 9389 9390=item * 9391 9392Figure out the prefix vs. what needs completing. 9393 9394=cut 9395 9396 $prefix = ( substr $text, 0, 1 ) . $1 . '::'; 9397 $text = $2; 9398 9399=pod 9400 9401=item * 9402 9403Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities. 9404 9405=cut 9406 9407 my @out = do { 9408 no strict 'refs'; 9409 map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/, 9410 keys %$pack; 9411 }; 9412 9413=pod 9414 9415=item * 9416 9417If 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. 9418 9419=cut 9420 9421 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { 9422 return db_complete( $out[0], $line, $start ); 9423 } 9424 9425 # Return the list of possibles. 9426 return sort @out; 9427 9428 } ## end if ($text =~ /^[\$@%](.*)::(.*)/) 9429 9430=pod 9431 9432=back 9433 9434=head3 Symbol completion: current package or package C<main> 9435 9436=cut 9437 9438 if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main) 9439=pod 9440 9441=over 4 9442 9443=item * 9444 9445If it's C<main>, delete main to just get C<::> leading. 9446 9447=cut 9448 9449 $pack = ( $package eq 'main' ? '' : $package ) . '::'; 9450 9451=pod 9452 9453=item * 9454 9455We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed. 9456 9457=cut 9458 9459 $prefix = substr $text, 0, 1; 9460 $text = substr $text, 1; 9461 9462 my @out; 9463 9464=pod 9465 9466=item * 9467 9468We look for the lexical scope above DB::DB and auto-complete lexical variables 9469if PadWalker could be loaded. 9470 9471=cut 9472 9473 if (not $text =~ /::/ and eval { 9474 local @INC = @INC; 9475 pop @INC if $INC[-1] eq '.'; 9476 require PadWalker } ) { 9477 my $level = 1; 9478 while (1) { 9479 my @info = caller($level); 9480 $level++; 9481 $level = -1, last 9482 if not @info; 9483 last if $info[3] eq 'DB::DB'; 9484 } 9485 if ($level > 0) { 9486 my $lexicals = PadWalker::peek_my($level); 9487 push @out, grep /^\Q$prefix$text/, keys %$lexicals; 9488 } 9489 } 9490 9491=pod 9492 9493=item * 9494 9495If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols. 9496 9497=cut 9498 9499 push @out, map "$prefix$_", grep /^\Q$text/, 9500 ( grep /^_?[a-zA-Z]/, do { no strict 'refs'; keys %$pack } ), 9501 ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) ); 9502 9503=item * 9504 9505If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol. 9506 9507=back 9508 9509=cut 9510 9511 if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { 9512 return db_complete( $out[0], $line, $start ); 9513 } 9514 9515 # Return the list of possibles. 9516 return sort @out; 9517 } ## end if ($text =~ /^[\$@%]/) 9518 9519=head3 Options 9520 9521We use C<option_val()> to look up the current value of the option. If there's 9522only a single value, we complete the command in such a way that it is a 9523complete command for setting the option in question. If there are multiple 9524possible values, we generate a command consisting of the option plus a trailing 9525question mark, which, if executed, will list the current value of the option. 9526 9527=cut 9528 9529 if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ ) 9530 { # Options after space 9531 # We look for the text to be matched in the list of possible options, 9532 # and fetch the current value. 9533 my @out = grep /^\Q$text/, @options; 9534 my $val = option_val( $out[0], undef ); 9535 9536 # Set up a 'query option's value' command. 9537 my $out = '? '; 9538 if ( not defined $val or $val =~ /[\n\r]/ ) { 9539 9540 # There's really nothing else we can do. 9541 } 9542 9543 # We have a value. Create a proper option-setting command. 9544 elsif ( $val =~ /\s/ ) { 9545 9546 # XXX This may be an extraneous variable. 9547 my $found; 9548 9549 # We'll want to quote the string (because of the embedded 9550 # whtespace), but we want to make sure we don't end up with 9551 # mismatched quote characters. We try several possibilities. 9552 foreach my $l ( split //, qq/\"\'\#\|/ ) { 9553 9554 # If we didn't find this quote character in the value, 9555 # quote it using this quote character. 9556 $out = "$l$val$l ", last if ( index $val, $l ) == -1; 9557 } 9558 } ## end elsif ($val =~ /\s/) 9559 9560 # Don't need any quotes. 9561 else { 9562 $out = "=$val "; 9563 } 9564 9565 # If there were multiple possible values, return '? ', which 9566 # makes the command into a query command. If there was just one, 9567 # have readline append that. 9568 $rl_attribs->{completer_terminator_character} = 9569 ( @out == 1 ? $out : '? ' ); 9570 9571 # Return list of possibilities. 9572 return sort @out; 9573 } ## end if ((substr $line, 0, ... 9574 9575=head3 Filename completion 9576 9577For entering filenames. We simply call C<readline>'s C<filename_list()> 9578method with the completion text to get the possible completions. 9579 9580=cut 9581 9582 return $term->filename_list($text); # filenames 9583 9584} ## end sub db_complete 9585 9586=head1 MISCELLANEOUS SUPPORT FUNCTIONS 9587 9588Functions that possibly ought to be somewhere else. 9589 9590=head2 end_report 9591 9592Say we're done. 9593 9594=cut 9595 9596sub end_report { 9597 local $\ = ''; 9598 print $OUT "Use 'q' to quit or 'R' to restart. 'h q' for details.\n"; 9599} 9600 9601=head2 clean_ENV 9602 9603If we have $ini_pids, save it in the environment; else remove it from the 9604environment. Used by the C<R> (restart) command. 9605 9606=cut 9607 9608sub clean_ENV { 9609 if ( defined($ini_pids) ) { 9610 $ENV{PERLDB_PIDS} = $ini_pids; 9611 } 9612 else { 9613 delete( $ENV{PERLDB_PIDS} ); 9614 } 9615} ## end sub clean_ENV 9616 9617# PERLDBf_... flag names from perl.h 9618our ( %DollarCaretP_flags, %DollarCaretP_flags_r ); 9619 9620BEGIN { 9621 %DollarCaretP_flags = ( 9622 PERLDBf_SUB => 0x01, # Debug sub enter/exit 9623 PERLDBf_LINE => 0x02, # Keep line # 9624 PERLDBf_NOOPT => 0x04, # Switch off optimizations 9625 PERLDBf_INTER => 0x08, # Preserve more data 9626 PERLDBf_SUBLINE => 0x10, # Keep subr source lines 9627 PERLDBf_SINGLE => 0x20, # Start with single-step on 9628 PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr 9629 PERLDBf_GOTO => 0x80, # Report goto: call DB::goto 9630 PERLDBf_NAMEEVAL => 0x100, # Informative names for evals 9631 PERLDBf_NAMEANON => 0x200, # Informative names for anon subs 9632 PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"} 9633 PERLDB_ALL => 0x33f, # No _NONAME, _GOTO 9634 ); 9635 # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger 9636 # doesn't need to set it. It's provided for the benefit of profilers and 9637 # other code analysers. 9638 9639 %DollarCaretP_flags_r = reverse %DollarCaretP_flags; 9640} 9641 9642sub parse_DollarCaretP_flags { 9643 my $flags = shift; 9644 $flags =~ s/^\s+//; 9645 $flags =~ s/\s+$//; 9646 my $acu = 0; 9647 foreach my $f ( split /\s*\|\s*/, $flags ) { 9648 my $value; 9649 if ( $f =~ /^0x([[:xdigit:]]+)$/ ) { 9650 $value = hex $1; 9651 } 9652 elsif ( $f =~ /^(\d+)$/ ) { 9653 $value = int $1; 9654 } 9655 elsif ( $f =~ /^DEFAULT$/i ) { 9656 $value = $DollarCaretP_flags{PERLDB_ALL}; 9657 } 9658 else { 9659 $f =~ /^(?:PERLDBf_)?(.*)$/i; 9660 $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) }; 9661 unless ( defined $value ) { 9662 print $OUT ( 9663 "Unrecognized \$^P flag '$f'!\n", 9664 "Acceptable flags are: " 9665 . join( ', ', sort keys %DollarCaretP_flags ), 9666 ", and hexadecimal and decimal numbers.\n" 9667 ); 9668 return undef; 9669 } 9670 } 9671 $acu |= $value; 9672 } 9673 $acu; 9674} 9675 9676sub expand_DollarCaretP_flags { 9677 my $DollarCaretP = shift; 9678 my @bits = ( 9679 map { 9680 my $n = ( 1 << $_ ); 9681 ( $DollarCaretP & $n ) 9682 ? ( $DollarCaretP_flags_r{$n} 9683 || sprintf( '0x%x', $n ) ) 9684 : () 9685 } 0 .. 31 9686 ); 9687 return @bits ? join( '|', @bits ) : 0; 9688} 9689 9690=over 4 9691 9692=item rerun 9693 9694Rerun the current session to: 9695 9696 rerun current position 9697 9698 rerun 4 command number 4 9699 9700 rerun -4 current command minus 4 (go back 4 steps) 9701 9702Whether this always makes sense, in the current context is unknowable, and is 9703in part left as a useful exercise for the reader. This sub returns the 9704appropriate arguments to rerun the current session. 9705 9706=cut 9707 9708sub rerun { 9709 my $i = shift; 9710 my @args; 9711 pop(@truehist); # strim 9712 unless (defined $truehist[$i]) { 9713 print "Unable to return to non-existent command: $i\n"; 9714 } else { 9715 $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist); 9716 my @temp = @truehist; # store 9717 push(@DB::typeahead, @truehist); # saved 9718 @truehist = @hist = (); # flush 9719 @args = restart(); # setup 9720 get_list("PERLDB_HIST"); # clean 9721 set_list("PERLDB_HIST", @temp); # reset 9722 } 9723 return @args; 9724} 9725 9726=item restart 9727 9728Restarting the debugger is a complex operation that occurs in several phases. 9729First, we try to reconstruct the command line that was used to invoke Perl 9730and the debugger. 9731 9732=cut 9733 9734sub restart { 9735 # I may not be able to resurrect you, but here goes ... 9736 print $OUT 9737"Warning: some settings and command-line options may be lost!\n"; 9738 my ( @script, @flags, $cl ); 9739 9740 # If warn was on before, turn it on again. 9741 push @flags, '-w' if $ini_warn; 9742 9743 # Rebuild the -I flags that were on the initial 9744 # command line. 9745 for (@ini_INC) { 9746 push @flags, '-I', $_; 9747 } 9748 9749 # Turn on taint if it was on before. 9750 push @flags, '-T' if ${^TAINT}; 9751 9752 # Arrange for setting the old INC: 9753 # Save the current @init_INC in the environment. 9754 set_list( "PERLDB_INC", @ini_INC ); 9755 9756 # If this was a perl one-liner, go to the "file" 9757 # corresponding to the one-liner read all the lines 9758 # out of it (except for the first one, which is going 9759 # to be added back on again when 'perl -d' runs: that's 9760 # the 'require perl5db.pl;' line), and add them back on 9761 # to the command line to be executed. 9762 if ( $0 eq '-e' ) { 9763 my $lines = *{$main::{'_<-e'}}{ARRAY}; 9764 for ( 1 .. $#$lines ) { # The first line is PERL5DB 9765 chomp( $cl = $lines->[$_] ); 9766 push @script, '-e', $cl; 9767 } 9768 } ## end if ($0 eq '-e') 9769 9770 # Otherwise we just reuse the original name we had 9771 # before. 9772 else { 9773 @script = $0; 9774 } 9775 9776=pod 9777 9778After the command line has been reconstructed, the next step is to save 9779the debugger's status in environment variables. The C<DB::set_list> routine 9780is used to save aggregate variables (both hashes and arrays); scalars are 9781just popped into environment variables directly. 9782 9783=cut 9784 9785 # If the terminal supported history, grab it and 9786 # save that in the environment. 9787 set_list( "PERLDB_HIST", 9788 $term->Features->{getHistory} 9789 ? $term->GetHistory 9790 : @hist ); 9791 9792 # Find all the files that were visited during this 9793 # session (i.e., the debugger had magic hashes 9794 # corresponding to them) and stick them in the environment. 9795 my @had_breakpoints = keys %had_breakpoints; 9796 set_list( "PERLDB_VISITED", @had_breakpoints ); 9797 9798 # Save the debugger options we chose. 9799 set_list( "PERLDB_OPT", %option ); 9800 # set_list( "PERLDB_OPT", options2remember() ); 9801 9802 # Save the break-on-loads. 9803 set_list( "PERLDB_ON_LOAD", %break_on_load ); 9804 9805=pod 9806 9807The most complex part of this is the saving of all of the breakpoints. They 9808can live in an awful lot of places, and we have to go through all of them, 9809find the breakpoints, and then save them in the appropriate environment 9810variable via C<DB::set_list>. 9811 9812=cut 9813 9814 # Go through all the breakpoints and make sure they're 9815 # still valid. 9816 my @hard; 9817 for ( 0 .. $#had_breakpoints ) { 9818 9819 # We were in this file. 9820 my $file = $had_breakpoints[$_]; 9821 9822 # Grab that file's magic line hash. 9823 *dbline = $main::{ '_<' . $file }; 9824 9825 # Skip out if it doesn't exist, or if the breakpoint 9826 # is in a postponed file (we'll do postponed ones 9827 # later). 9828 next unless %dbline or $postponed_file{$file}; 9829 9830 # In an eval. This is a little harder, so we'll 9831 # do more processing on that below. 9832 ( push @hard, $file ), next 9833 if $file =~ /^\(\w*eval/; 9834 9835 # XXX I have no idea what this is doing. Yet. 9836 my @add; 9837 @add = %{ $postponed_file{$file} } 9838 if $postponed_file{$file}; 9839 9840 # Save the list of all the breakpoints for this file. 9841 set_list( "PERLDB_FILE_$_", %dbline, @add ); 9842 9843 # Serialize the extra data %breakpoints_data hash. 9844 # That's a bug fix. 9845 set_list( "PERLDB_FILE_ENABLED_$_", 9846 map { _is_breakpoint_enabled($file, $_) ? 1 : 0 } 9847 sort { $a <=> $b } keys(%dbline) 9848 ) 9849 } ## end for (0 .. $#had_breakpoints) 9850 9851 # The breakpoint was inside an eval. This is a little 9852 # more difficult. XXX and I don't understand it. 9853 foreach my $hard_file (@hard) { 9854 # Get over to the eval in question. 9855 *dbline = $main::{ '_<' . $hard_file }; 9856 my $quoted = quotemeta $hard_file; 9857 my %subs; 9858 for my $sub ( keys %sub ) { 9859 if (my ($n1, $n2) = $sub{$sub} =~ /\A$quoted:(\d+)-(\d+)\z/) { 9860 $subs{$sub} = [ $n1, $n2 ]; 9861 } 9862 } 9863 unless (%subs) { 9864 print {$OUT} 9865 "No subroutines in $hard_file, ignoring breakpoints.\n"; 9866 next; 9867 } 9868 LINES: foreach my $line ( keys %dbline ) { 9869 9870 # One breakpoint per sub only: 9871 my ( $offset, $found ); 9872 SUBS: foreach my $sub ( keys %subs ) { 9873 if ( 9874 $subs{$sub}->[1] >= $line # Not after the subroutine 9875 and ( 9876 not defined $offset # Not caught 9877 or $offset < 0 9878 ) 9879 ) 9880 { # or badly caught 9881 $found = $sub; 9882 $offset = $line - $subs{$sub}->[0]; 9883 if ($offset >= 0) { 9884 $offset = "+$offset"; 9885 last SUBS; 9886 } 9887 } ## end if ($subs{$sub}->[1] >=... 9888 } ## end for $sub (keys %subs) 9889 if ( defined $offset ) { 9890 $postponed{$found} = 9891 "break $offset if $dbline{$line}"; 9892 } 9893 else { 9894 print {$OUT} 9895 ("Breakpoint in ${hard_file}:$line ignored:" 9896 . " after all the subroutines.\n"); 9897 } 9898 } ## end for $line (keys %dbline) 9899 } ## end for (@hard) 9900 9901 # Save the other things that don't need to be 9902 # processed. 9903 set_list( "PERLDB_POSTPONE", %postponed ); 9904 set_list( "PERLDB_PRETYPE", @$pretype ); 9905 set_list( "PERLDB_PRE", @$pre ); 9906 set_list( "PERLDB_POST", @$post ); 9907 set_list( "PERLDB_TYPEAHEAD", @typeahead ); 9908 9909 # We are officially restarting. 9910 $ENV{PERLDB_RESTART} = 1; 9911 9912 # We are junking all child debuggers. 9913 delete $ENV{PERLDB_PIDS}; # Restore ini state 9914 9915 # Set this back to the initial pid. 9916 $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids; 9917 9918=pod 9919 9920After all the debugger status has been saved, we take the command we built up 9921and then return it, so we can C<exec()> it. The debugger will spot the 9922C<PERLDB_RESTART> environment variable and realize it needs to reload its state 9923from the environment. 9924 9925=cut 9926 9927 # And run Perl again. Add the "-d" flag, all the 9928 # flags we built up, the script (whether a one-liner 9929 # or a file), add on the -emacs flag for a client editor, 9930 # and then the old arguments. 9931 9932 return ($^X, '-d', @flags, @script, ($client_editor ? '-emacs' : ()), @ARGS); 9933 9934}; # end restart 9935 9936=back 9937 9938=head1 END PROCESSING - THE C<END> BLOCK 9939 9940Come here at the very end of processing. We want to go into a 9941loop where we allow the user to enter commands and interact with the 9942debugger, but we don't want anything else to execute. 9943 9944First we set the C<$finished> variable, so that some commands that 9945shouldn't be run after the end of program quit working. 9946 9947We then figure out whether we're truly done (as in the user entered a C<q> 9948command, or we finished execution while running nonstop). If we aren't, 9949we set C<$single> to 1 (causing the debugger to get control again). 9950 9951We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...> 9952message and returns control to the debugger. Repeat. 9953 9954When the user finally enters a C<q> command, C<$fall_off_end> is set to 99551 and the C<END> block simply exits with C<$single> set to 0 (don't 9956break, run to completion.). 9957 9958=cut 9959 9960END { 9961 $finished = 1 if $inhibit_exit; # So that some commands may be disabled. 9962 $fall_off_end = 1 unless $inhibit_exit; 9963 9964 # Do not stop in at_exit() and destructors on exit: 9965 if ($fall_off_end or $runnonstop) { 9966 save_hist(); 9967 } else { 9968 $DB::single = 1; 9969 DB::fake::at_exit(); 9970 } 9971} ## end END 9972 9973=head1 PRE-5.8 COMMANDS 9974 9975Some of the commands changed function quite a bit in the 5.8 command 9976realignment, so much so that the old code had to be replaced completely. 9977Because we wanted to retain the option of being able to go back to the 9978former command set, we moved the old code off to this section. 9979 9980There's an awful lot of duplicated code here. We've duplicated the 9981comments to keep things clear. 9982 9983=head2 Null command 9984 9985Does nothing. Used to I<turn off> commands. 9986 9987=cut 9988 9989sub cmd_pre580_null { 9990 9991 # do nothing... 9992} 9993 9994=head2 Old C<a> command 9995 9996This version added actions if you supplied them, and deleted them 9997if you didn't. 9998 9999=cut 10000 10001sub cmd_pre580_a { 10002 my $xcmd = shift; 10003 my $cmd = shift; 10004 10005 # Argument supplied. Add the action. 10006 if ( $cmd =~ /^(\d*)\s*(.*)/ ) { 10007 10008 # If the line isn't there, use the current line. 10009 my $i = $1 || $line; 10010 my $j = $2; 10011 10012 # If there is an action ... 10013 if ( length $j ) { 10014 10015 # ... but the line isn't breakable, skip it. 10016 if ( $dbline[$i] == 0 ) { 10017 print $OUT "Line $i may not have an action.\n"; 10018 } 10019 else { 10020 10021 # ... and the line is breakable: 10022 # Mark that there's an action in this file. 10023 $had_breakpoints{$filename} |= 2; 10024 10025 # Delete any current action. 10026 $dbline{$i} =~ s/\0[^\0]*//; 10027 10028 # Add the new action, continuing the line as needed. 10029 $dbline{$i} .= "\0" . action($j); 10030 } 10031 } ## end if (length $j) 10032 10033 # No action supplied. 10034 else { 10035 10036 # Delete the action. 10037 $dbline{$i} =~ s/\0[^\0]*//; 10038 10039 # Mark as having no break or action if nothing's left. 10040 delete $dbline{$i} if $dbline{$i} eq ''; 10041 } 10042 } ## end if ($cmd =~ /^(\d*)\s*(.*)/) 10043} ## end sub cmd_pre580_a 10044 10045=head2 Old C<b> command 10046 10047Add breakpoints. 10048 10049=cut 10050 10051sub cmd_pre580_b { 10052 my $xcmd = shift; 10053 my $cmd = shift; 10054 my $dbline = shift; 10055 10056 # Break on load. 10057 if ( $cmd =~ /^load\b\s*(.*)/ ) { 10058 my $file = $1; 10059 $file =~ s/\s+$//; 10060 cmd_b_load($file); 10061 } 10062 10063 # b compile|postpone <some sub> [<condition>] 10064 # The interpreter actually traps this one for us; we just put the 10065 # necessary condition in the %postponed hash. 10066 elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { 10067 10068 # Capture the condition if there is one. Make it true if none. 10069 my $cond = length $3 ? $3 : '1'; 10070 10071 # Save the sub name and set $break to 1 if $1 was 'postpone', 0 10072 # if it was 'compile'. 10073 my ( $subname, $break ) = ( $2, $1 eq 'postpone' ); 10074 10075 # De-Perl4-ify the name - ' separators to ::. 10076 $subname =~ s/\'/::/g; 10077 10078 # Qualify it into the current package unless it's already qualified. 10079 $subname = "${package}::" . $subname 10080 unless $subname =~ /::/; 10081 10082 # Add main if it starts with ::. 10083 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 10084 10085 # Save the break type for this sub. 10086 $postponed{$subname} = $break ? "break +0 if $cond" : "compile"; 10087 } ## end elsif ($cmd =~ ... 10088 10089 # b <sub name> [<condition>] 10090 elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { 10091 my $subname = $1; 10092 my $cond = length $2 ? $2 : '1'; 10093 cmd_b_sub( $subname, $cond ); 10094 } 10095 # b <line> [<condition>]. 10096 elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) { 10097 my $i = $1 || $dbline; 10098 my $cond = length $2 ? $2 : '1'; 10099 cmd_b_line( $i, $cond ); 10100 } 10101} ## end sub cmd_pre580_b 10102 10103=head2 Old C<D> command 10104 10105Delete all breakpoints unconditionally. 10106 10107=cut 10108 10109sub cmd_pre580_D { 10110 my $xcmd = shift; 10111 my $cmd = shift; 10112 if ( $cmd =~ /^\s*$/ ) { 10113 print $OUT "Deleting all breakpoints...\n"; 10114 10115 # %had_breakpoints lists every file that had at least one 10116 # breakpoint in it. 10117 my $file; 10118 for $file ( keys %had_breakpoints ) { 10119 10120 # Switch to the desired file temporarily. 10121 local *dbline = $main::{ '_<' . $file }; 10122 10123 $max = $#dbline; 10124 my $was; 10125 10126 # For all lines in this file ... 10127 for my $i (1 .. $max) { 10128 10129 # If there's a breakpoint or action on this line ... 10130 if ( defined $dbline{$i} ) { 10131 10132 # ... remove the breakpoint. 10133 $dbline{$i} =~ s/^[^\0]+//; 10134 if ( $dbline{$i} =~ s/^\0?$// ) { 10135 10136 # Remove the entry altogether if no action is there. 10137 delete $dbline{$i}; 10138 } 10139 } ## end if (defined $dbline{$i... 10140 } ## end for my $i (1 .. $max) 10141 10142 # If, after we turn off the "there were breakpoints in this file" 10143 # bit, the entry in %had_breakpoints for this file is zero, 10144 # we should remove this file from the hash. 10145 if ( not $had_breakpoints{$file} &= ~1 ) { 10146 delete $had_breakpoints{$file}; 10147 } 10148 } ## end for $file (keys %had_breakpoints) 10149 10150 # Kill off all the other breakpoints that are waiting for files that 10151 # haven't been loaded yet. 10152 undef %postponed; 10153 undef %postponed_file; 10154 undef %break_on_load; 10155 } ## end if ($cmd =~ /^\s*$/) 10156} ## end sub cmd_pre580_D 10157 10158=head2 Old C<h> command 10159 10160Print help. Defaults to printing the long-form help; the 5.8 version 10161prints the summary by default. 10162 10163=cut 10164 10165sub cmd_pre580_h { 10166 my $xcmd = shift; 10167 my $cmd = shift; 10168 10169 # Print the *right* help, long format. 10170 if ( $cmd =~ /^\s*$/ ) { 10171 print_help($pre580_help); 10172 } 10173 10174 # 'h h' - explicitly-requested summary. 10175 elsif ( $cmd =~ /^h\s*/ ) { 10176 print_help($pre580_summary); 10177 } 10178 10179 # Find and print a command's help. 10180 elsif ( $cmd =~ /^h\s+(\S.*)$/ ) { 10181 my $asked = $1; # for proper errmsg 10182 my $qasked = quotemeta($asked); # for searching 10183 # XXX: finds CR but not <CR> 10184 if ( 10185 $pre580_help =~ /^ 10186 <? # Optional '<' 10187 (?:[IB]<) # Optional markup 10188 $qasked # The command name 10189 /mx 10190 ) 10191 { 10192 10193 while ( 10194 $pre580_help =~ /^ 10195 ( # The command help: 10196 <? # Optional '<' 10197 (?:[IB]<) # Optional markup 10198 $qasked # The command name 10199 ([\s\S]*?) # Lines starting with tabs 10200 \n # Final newline 10201 ) 10202 (?!\s)/mgx 10203 ) # Line not starting with space 10204 # (Next command's help) 10205 { 10206 print_help($1); 10207 } 10208 } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m) 10209 10210 # Help not found. 10211 else { 10212 print_help("B<$asked> is not a debugger command.\n"); 10213 } 10214 } ## end elsif ($cmd =~ /^h\s+(\S.*)$/) 10215} ## end sub cmd_pre580_h 10216 10217=head2 Old C<W> command 10218 10219C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all. 10220 10221=cut 10222 10223sub cmd_pre580_W { 10224 my $xcmd = shift; 10225 my $cmd = shift; 10226 10227 # Delete all watch expressions. 10228 if ( $cmd =~ /^$/ ) { 10229 10230 # No watching is going on. 10231 $trace &= ~2; 10232 10233 # Kill all the watch expressions and values. 10234 @to_watch = @old_watch = (); 10235 } 10236 10237 # Add a watch expression. 10238 elsif ( $cmd =~ /^(.*)/s ) { 10239 10240 # add it to the list to be watched. 10241 push @to_watch, $1; 10242 10243 # Get the current value of the expression. 10244 # Doesn't handle expressions returning list values! 10245 $evalarg = $1; 10246 # The &-call is here to ascertain the mutability of @_. 10247 my ($val) = &DB::eval; 10248 $val = ( defined $val ) ? "'$val'" : 'undef'; 10249 10250 # Save it. 10251 push @old_watch, $val; 10252 10253 # We're watching stuff. 10254 $trace |= 2; 10255 10256 } ## end elsif ($cmd =~ /^(.*)/s) 10257} ## end sub cmd_pre580_W 10258 10259=head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS 10260 10261The debugger used to have a bunch of nearly-identical code to handle 10262the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and 10263C<cmd_prepost> unify all this into one set of code to handle the 10264appropriate actions. 10265 10266=head2 C<cmd_pre590_prepost> 10267 10268A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't 10269do something destructive. In pre 5.8 debuggers, the default action was to 10270delete all the actions. 10271 10272=cut 10273 10274sub cmd_pre590_prepost { 10275 my $cmd = shift; 10276 my $line = shift || '*'; 10277 my $dbline = shift; 10278 10279 return cmd_prepost( $cmd, $line, $dbline ); 10280} ## end sub cmd_pre590_prepost 10281 10282=head2 C<cmd_prepost> 10283 10284Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc. 10285Since the lists of actions are all held in arrays that are pointed to by 10286references anyway, all we have to do is pick the right array reference and 10287then use generic code to all, delete, or list actions. 10288 10289=cut 10290 10291sub cmd_prepost { 10292 my $cmd = shift; 10293 10294 # No action supplied defaults to 'list'. 10295 my $line = shift || '?'; 10296 10297 # Figure out what to put in the prompt. 10298 my $which = ''; 10299 10300 # Make sure we have some array or another to address later. 10301 # This means that if for some reason the tests fail, we won't be 10302 # trying to stash actions or delete them from the wrong place. 10303 my $aref = []; 10304 10305 # < - Perl code to run before prompt. 10306 if ( $cmd =~ /^\</o ) { 10307 $which = 'pre-perl'; 10308 $aref = $pre; 10309 } 10310 10311 # > - Perl code to run after prompt. 10312 elsif ( $cmd =~ /^\>/o ) { 10313 $which = 'post-perl'; 10314 $aref = $post; 10315 } 10316 10317 # { - first check for properly-balanced braces. 10318 elsif ( $cmd =~ /^\{/o ) { 10319 if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) { 10320 print $OUT 10321"$cmd is now a debugger command\nuse ';$cmd' if you mean Perl code\n"; 10322 } 10323 10324 # Properly balanced. Pre-prompt debugger actions. 10325 else { 10326 $which = 'pre-debugger'; 10327 $aref = $pretype; 10328 } 10329 } ## end elsif ( $cmd =~ /^\{/o ) 10330 10331 # Did we find something that makes sense? 10332 unless ($which) { 10333 print $OUT "Confused by command: $cmd\n"; 10334 } 10335 10336 # Yes. 10337 else { 10338 10339 # List actions. 10340 if ( $line =~ /^\s*\?\s*$/o ) { 10341 unless (@$aref) { 10342 10343 # Nothing there. Complain. 10344 print $OUT "No $which actions.\n"; 10345 } 10346 else { 10347 10348 # List the actions in the selected list. 10349 print $OUT "$which commands:\n"; 10350 foreach my $action (@$aref) { 10351 print $OUT "\t$cmd -- $action\n"; 10352 } 10353 } ## end else 10354 } ## end if ( $line =~ /^\s*\?\s*$/o) 10355 10356 # Might be a delete. 10357 else { 10358 if ( length($cmd) == 1 ) { 10359 if ( $line =~ /^\s*\*\s*$/o ) { 10360 10361 # It's a delete. Get rid of the old actions in the 10362 # selected list.. 10363 @$aref = (); 10364 print $OUT "All $cmd actions cleared.\n"; 10365 } 10366 else { 10367 10368 # Replace all the actions. (This is a <, >, or {). 10369 @$aref = action($line); 10370 } 10371 } ## end if ( length($cmd) == 1) 10372 elsif ( length($cmd) == 2 ) { 10373 10374 # Add the action to the line. (This is a <<, >>, or {{). 10375 push @$aref, action($line); 10376 } 10377 else { 10378 10379 # <<<, >>>>, {{{{{{ ... something not a command. 10380 print $OUT 10381 "Confused by strange length of $which command($cmd)...\n"; 10382 } 10383 } ## end else [ if ( $line =~ /^\s*\?\s*$/o) 10384 } ## end else 10385} ## end sub cmd_prepost 10386 10387=head1 C<DB::fake> 10388 10389Contains the C<at_exit> routine that the debugger uses to issue the 10390C<Debugged program terminated ...> message after the program completes. See 10391the L<C<END>|/END PROCESSING - THE END BLOCK> block documentation for more 10392details. 10393 10394=cut 10395 10396package DB::fake; 10397 10398sub at_exit { 10399 "Debugged program terminated. Use 'q' to quit or 'R' to restart."; 10400} 10401 10402package DB; # Do not trace this 1; below! 10403 104041; 10405 10406 10407