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1 2 =head1 NAME 3 4 perl5db.pl - the perl debugger 5 6 =head1 SYNOPSIS 7 8 perl -d your_Perl_script 9 10 =head1 DESCRIPTION 11 12 C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when 13 you invoke a script with C<perl -d>. This documentation tries to outline the 14 structure and services provided by C<perl5db.pl>, and to describe how you 15 can use them. 16 17 =head1 GENERAL NOTES 18 19 The debugger can look pretty forbidding to many Perl programmers. There are 20 a number of reasons for this, many stemming out of the debugger's history. 21 22 When the debugger was first written, Perl didn't have a lot of its nicer 23 features - no references, no lexical variables, no closures, no object-oriented 24 programming. So a lot of the things one would normally have done using such 25 features was done using global variables, globs and the C<local()> operator 26 in creative ways. 27 28 Some of these have survived into the current debugger; a few of the more 29 interesting and still-useful idioms are noted in this section, along with notes 30 on the comments themselves. 31 32 =head2 Why not use more lexicals? 33 34 Experienced Perl programmers will note that the debugger code tends to use 35 mostly package globals rather than lexically-scoped variables. This is done 36 to allow a significant amount of control of the debugger from outside the 37 debugger itself. 38 39 Unfortunately, though the variables are accessible, they're not well 40 documented, so it's generally been a decision that hasn't made a lot of 41 difference to most users. Where appropriate, comments have been added to 42 make variables more accessible and usable, with the understanding that these 43 I<are> debugger internals, and are therefore subject to change. Future 44 development should probably attempt to replace the globals with a well-defined 45 API, but for now, the variables are what we've got. 46 47 =head2 Automated variable stacking via C<local()> 48 49 As you may recall from reading C<perlfunc>, the C<local()> operator makes a 50 temporary copy of a variable in the current scope. When the scope ends, the 51 old copy is restored. This is often used in the debugger to handle the 52 automatic stacking of variables during recursive calls: 53 54 sub foo { 55 local $some_global++; 56 57 # Do some stuff, then ... 58 return; 59 } 60 61 What happens is that on entry to the subroutine, C<$some_global> is localized, 62 then altered. When the subroutine returns, Perl automatically undoes the 63 localization, restoring the previous value. Voila, automatic stack management. 64 65 The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>, 66 which lets the debugger get control inside of C<eval>'ed code. The debugger 67 localizes a saved copy of C<$@> inside the subroutine, which allows it to 68 keep C<$@> safe until it C<DB::eval> returns, at which point the previous 69 value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep 70 track of C<$@> inside C<eval>s which C<eval> other C<eval's>. 71 72 In any case, watch for this pattern. It occurs fairly often. 73 74 =head2 The C<^> trick 75 76 This is used to cleverly reverse the sense of a logical test depending on 77 the value of an auxiliary variable. For instance, the debugger's C<S> 78 (search for subroutines by pattern) allows you to negate the pattern 79 like this: 80 81 # Find all non-'foo' subs: 82 S !/foo/ 83 84 Boolean algebra states that the truth table for XOR looks like this: 85 86 =over 4 87 88 =item * 0 ^ 0 = 0 89 90 (! not present and no match) --> false, don't print 91 92 =item * 0 ^ 1 = 1 93 94 (! not present and matches) --> true, print 95 96 =item * 1 ^ 0 = 1 97 98 (! present and no match) --> true, print 99 100 =item * 1 ^ 1 = 0 101 102 (! present and matches) --> false, don't print 103 104 =back 105 106 As you can see, the first pair applies when C<!> isn't supplied, and 107 the second pair applies when it is. The XOR simply allows us to 108 compact a more complicated if-then-elseif-else into a more elegant 109 (but perhaps overly clever) single test. After all, it needed this 110 explanation... 111 112 =head2 FLAGS, FLAGS, FLAGS 113 114 There is a certain C programming legacy in the debugger. Some variables, 115 such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed 116 of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces 117 of state to be stored independently in a single scalar. 118 119 A test like 120 121 if ($scalar & 4) ... 122 123 is checking to see if the appropriate bit is on. Since each bit can be 124 "addressed" independently in this way, C<$scalar> is acting sort of like 125 an array of bits. Obviously, since the contents of C<$scalar> are just a 126 bit-pattern, we can save and restore it easily (it will just look like 127 a number). 128 129 The problem, is of course, that this tends to leave magic numbers scattered 130 all over your program whenever a bit is set, cleared, or checked. So why do 131 it? 132 133 =over 4 134 135 =item * 136 137 First, doing an arithmetical or bitwise operation on a scalar is 138 just about the fastest thing you can do in Perl: C<use constant> actually 139 creates a subroutine call, and array and hash lookups are much slower. Is 140 this over-optimization at the expense of readability? Possibly, but the 141 debugger accesses these variables a I<lot>. Any rewrite of the code will 142 probably have to benchmark alternate implementations and see which is the 143 best balance of readability and speed, and then document how it actually 144 works. 145 146 =item * 147 148 Second, it's very easy to serialize a scalar number. This is done in 149 the restart code; the debugger state variables are saved in C<%ENV> and then 150 restored when the debugger is restarted. Having them be just numbers makes 151 this trivial. 152 153 =item * 154 155 Third, some of these variables are being shared with the Perl core 156 smack in the middle of the interpreter's execution loop. It's much faster for 157 a C program (like the interpreter) to check a bit in a scalar than to access 158 several different variables (or a Perl array). 159 160 =back 161 162 =head2 What are those C<XXX> comments for? 163 164 Any comment containing C<XXX> means that the comment is either somewhat 165 speculative - it's not exactly clear what a given variable or chunk of 166 code is doing, or that it is incomplete - the basics may be clear, but the 167 subtleties are not completely documented. 168 169 Send in a patch if you can clear up, fill out, or clarify an C<XXX>. 170 171 =head1 DATA STRUCTURES MAINTAINED BY CORE 172 173 There are a number of special data structures provided to the debugger by 174 the Perl interpreter. 175 176 The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob 177 assignment) contains the text from C<$filename>, with each element 178 corresponding to a single line of C<$filename>. 179 180 The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob 181 assignment) contains breakpoints and actions. The keys are line numbers; 182 you can set individual values, but not the whole hash. The Perl interpreter 183 uses this hash to determine where breakpoints have been set. Any true value is 184 considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>. 185 Values are magical in numeric context: 1 if the line is breakable, 0 if not. 186 187 The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>. 188 This is also the case for evaluated strings that contain subroutines, or 189 which are currently being executed. The $filename for C<eval>ed strings looks 190 like C<(eval 34)> or C<(re_eval 19)>. 191 192 =head1 DEBUGGER STARTUP 193 194 When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for 195 non-interactive sessions, C<.perldb> for interactive ones) that can set a number 196 of options. In addition, this file may define a subroutine C<&afterinit> 197 that will be executed (in the debugger's context) after the debugger has 198 initialized itself. 199 200 Next, it checks the C<PERLDB_OPTS> environment variable and treats its 201 contents as the argument of a C<o> command in the debugger. 202 203 =head2 STARTUP-ONLY OPTIONS 204 205 The following options can only be specified at startup. 206 To set them in your rcfile, add a call to 207 C<&parse_options("optionName=new_value")>. 208 209 =over 4 210 211 =item * TTY 212 213 the TTY to use for debugging i/o. 214 215 =item * noTTY 216 217 if set, goes in NonStop mode. On interrupt, if TTY is not set, 218 uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using 219 Term::Rendezvous. Current variant is to have the name of TTY in this 220 file. 221 222 =item * ReadLine 223 224 if false, a dummy ReadLine is used, so you can debug 225 ReadLine applications. 226 227 =item * NonStop 228 229 if true, no i/o is performed until interrupt. 230 231 =item * LineInfo 232 233 file or pipe to print line number info to. If it is a 234 pipe, a short "emacs like" message is used. 235 236 =item * RemotePort 237 238 host:port to connect to on remote host for remote debugging. 239 240 =item * HistFile 241 242 file to store session history to. There is no default and so no 243 history file is written unless this variable is explicitly set. 244 245 =item * HistSize 246 247 number of commands to store to the file specified in C<HistFile>. 248 Default is 100. 249 250 =back 251 252 =head3 SAMPLE RCFILE 253 254 &parse_options("NonStop=1 LineInfo=db.out"); 255 sub afterinit { $trace = 1; } 256 257 The script will run without human intervention, putting trace 258 information into C<db.out>. (If you interrupt it, you had better 259 reset C<LineInfo> to something I<interactive>!) 260 261 =head1 INTERNALS DESCRIPTION 262 263 =head2 DEBUGGER INTERFACE VARIABLES 264 265 Perl supplies the values for C<%sub>. It effectively inserts 266 a C<&DB::DB();> in front of each place that can have a 267 breakpoint. At each subroutine call, it calls C<&DB::sub> with 268 C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN 269 {require 'perl5db.pl'}> before the first line. 270 271 After each C<require>d file is compiled, but before it is executed, a 272 call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename> 273 is the expanded name of the C<require>d file (as found via C<%INC>). 274 275 =head3 IMPORTANT INTERNAL VARIABLES 276 277 =head4 C<$CreateTTY> 278 279 Used to control when the debugger will attempt to acquire another TTY to be 280 used for input. 281 282 =over 283 284 =item * 1 - on C<fork()> 285 286 =item * 2 - debugger is started inside debugger 287 288 =item * 4 - on startup 289 290 =back 291 292 =head4 C<$doret> 293 294 The value -2 indicates that no return value should be printed. 295 Any other positive value causes C<DB::sub> to print return values. 296 297 =head4 C<$evalarg> 298 299 The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current 300 contents of C<@_> when C<DB::eval> is called. 301 302 =head4 C<$frame> 303 304 Determines what messages (if any) will get printed when a subroutine (or eval) 305 is entered or exited. 306 307 =over 4 308 309 =item * 0 - No enter/exit messages 310 311 =item * 1 - Print I<entering> messages on subroutine entry 312 313 =item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2. 314 315 =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. 316 317 =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. 318 319 =item * 16 - Adds C<I<context> return from I<subname>: I<value>> messages on subroutine/eval exit. Ignored if C<4> is is not on. 320 321 =back 322 323 To get everything, use C<$frame=30> (or C<o f=30> as a debugger command). 324 The debugger internally juggles the value of C<$frame> during execution to 325 protect external modules that the debugger uses from getting traced. 326 327 =head4 C<$level> 328 329 Tracks current debugger nesting level. Used to figure out how many 330 C<E<lt>E<gt>> pairs to surround the line number with when the debugger 331 outputs a prompt. Also used to help determine if the program has finished 332 during command parsing. 333 334 =head4 C<$onetimeDump> 335 336 Controls what (if anything) C<DB::eval()> will print after evaluating an 337 expression. 338 339 =over 4 340 341 =item * C<undef> - don't print anything 342 343 =item * C<dump> - use C<dumpvar.pl> to display the value returned 344 345 =item * C<methods> - print the methods callable on the first item returned 346 347 =back 348 349 =head4 C<$onetimeDumpDepth> 350 351 Controls how far down C<dumpvar.pl> will go before printing C<...> while 352 dumping a structure. Numeric. If C<undef>, print all levels. 353 354 =head4 C<$signal> 355 356 Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>, 357 which is called before every statement, checks this and puts the user into 358 command mode if it finds C<$signal> set to a true value. 359 360 =head4 C<$single> 361 362 Controls behavior during single-stepping. Stacked in C<@stack> on entry to 363 each subroutine; popped again at the end of each subroutine. 364 365 =over 4 366 367 =item * 0 - run continuously. 368 369 =item * 1 - single-step, go into subs. The C<s> command. 370 371 =item * 2 - single-step, don't go into subs. The C<n> command. 372 373 =item * 4 - print current sub depth (turned on to force this when C<too much 374 recursion> occurs. 375 376 =back 377 378 =head4 C<$trace> 379 380 Controls the output of trace information. 381 382 =over 4 383 384 =item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed) 385 386 =item * 2 - watch expressions are active 387 388 =item * 4 - user defined a C<watchfunction()> in C<afterinit()> 389 390 =back 391 392 =head4 C<$slave_editor> 393 394 1 if C<LINEINFO> was directed to a pipe; 0 otherwise. 395 396 =head4 C<@cmdfhs> 397 398 Stack of filehandles that C<DB::readline()> will read commands from. 399 Manipulated by the debugger's C<source> command and C<DB::readline()> itself. 400 401 =head4 C<@dbline> 402 403 Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> , 404 supplied by the Perl interpreter to the debugger. Contains the source. 405 406 =head4 C<@old_watch> 407 408 Previous values of watch expressions. First set when the expression is 409 entered; reset whenever the watch expression changes. 410 411 =head4 C<@saved> 412 413 Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>) 414 so that the debugger can substitute safe values while it's running, and 415 restore them when it returns control. 416 417 =head4 C<@stack> 418 419 Saves the current value of C<$single> on entry to a subroutine. 420 Manipulated by the C<c> command to turn off tracing in all subs above the 421 current one. 422 423 =head4 C<@to_watch> 424 425 The 'watch' expressions: to be evaluated before each line is executed. 426 427 =head4 C<@typeahead> 428 429 The typeahead buffer, used by C<DB::readline>. 430 431 =head4 C<%alias> 432 433 Command aliases. Stored as character strings to be substituted for a command 434 entered. 435 436 =head4 C<%break_on_load> 437 438 Keys are file names, values are 1 (break when this file is loaded) or undef 439 (don't break when it is loaded). 440 441 =head4 C<%dbline> 442 443 Keys are line numbers, values are C<condition\0action>. If used in numeric 444 context, values are 0 if not breakable, 1 if breakable, no matter what is 445 in the actual hash entry. 446 447 =head4 C<%had_breakpoints> 448 449 Keys are file names; values are bitfields: 450 451 =over 4 452 453 =item * 1 - file has a breakpoint in it. 454 455 =item * 2 - file has an action in it. 456 457 =back 458 459 A zero or undefined value means this file has neither. 460 461 =head4 C<%option> 462 463 Stores the debugger options. These are character string values. 464 465 =head4 C<%postponed> 466 467 Saves breakpoints for code that hasn't been compiled yet. 468 Keys are subroutine names, values are: 469 470 =over 4 471 472 =item * C<compile> - break when this sub is compiled 473 474 =item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified. 475 476 =back 477 478 =head4 C<%postponed_file> 479 480 This hash keeps track of breakpoints that need to be set for files that have 481 not yet been compiled. Keys are filenames; values are references to hashes. 482 Each of these hashes is keyed by line number, and its values are breakpoint 483 definitions (C<condition\0action>). 484 485 =head1 DEBUGGER INITIALIZATION 486 487 The debugger's initialization actually jumps all over the place inside this 488 package. This is because there are several BEGIN blocks (which of course 489 execute immediately) spread through the code. Why is that? 490 491 The debugger needs to be able to change some things and set some things up 492 before the debugger code is compiled; most notably, the C<$deep> variable that 493 C<DB::sub> uses to tell when a program has recursed deeply. In addition, the 494 debugger has to turn off warnings while the debugger code is compiled, but then 495 restore them to their original setting before the program being debugged begins 496 executing. 497 498 The first C<BEGIN> block simply turns off warnings by saving the current 499 setting of C<$^W> and then setting it to zero. The second one initializes 500 the debugger variables that are needed before the debugger begins executing. 501 The third one puts C<$^X> back to its former value. 502 503 We'll detail the second C<BEGIN> block later; just remember that if you need 504 to initialize something before the debugger starts really executing, that's 505 where it has to go. 506 507 =cut 508 509 package DB; 510 511 BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl 512 513 # Debugger for Perl 5.00x; perl5db.pl patch level: 514 $VERSION = 1.30; 515 516 $header = "perl5db.pl version $VERSION"; 517 518 =head1 DEBUGGER ROUTINES 519 520 =head2 C<DB::eval()> 521 522 This function replaces straight C<eval()> inside the debugger; it simplifies 523 the process of evaluating code in the user's context. 524 525 The code to be evaluated is passed via the package global variable 526 C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>. 527 528 Before we do the C<eval()>, we preserve the current settings of C<$trace>, 529 C<$single>, C<$^D> and C<$usercontext>. The latter contains the 530 preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the 531 user's current package, grabbed when C<DB::DB> got control. This causes the 532 proper context to be used when the eval is actually done. Afterward, we 533 restore C<$trace>, C<$single>, and C<$^D>. 534 535 Next we need to handle C<$@> without getting confused. We save C<$@> in a 536 local lexical, localize C<$saved[0]> (which is where C<save()> will put 537 C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>, 538 C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values 539 considered sane by the debugger. If there was an C<eval()> error, we print 540 it on the debugger's output. If C<$onetimedump> is defined, we call 541 C<dumpit> if it's set to 'dump', or C<methods> if it's set to 542 'methods'. Setting it to something else causes the debugger to do the eval 543 but not print the result - handy if you want to do something else with it 544 (the "watch expressions" code does this to get the value of the watch 545 expression but not show it unless it matters). 546 547 In any case, we then return the list of output from C<eval> to the caller, 548 and unwinding restores the former version of C<$@> in C<@saved> as well 549 (the localization of C<$saved[0]> goes away at the end of this scope). 550 551 =head3 Parameters and variables influencing execution of DB::eval() 552 553 C<DB::eval> isn't parameterized in the standard way; this is to keep the 554 debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things. 555 The variables listed below influence C<DB::eval()>'s execution directly. 556 557 =over 4 558 559 =item C<$evalarg> - the thing to actually be eval'ed 560 561 =item C<$trace> - Current state of execution tracing 562 563 =item C<$single> - Current state of single-stepping 564 565 =item C<$onetimeDump> - what is to be displayed after the evaluation 566 567 =item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results 568 569 =back 570 571 The following variables are altered by C<DB::eval()> during its execution. They 572 are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>. 573 574 =over 4 575 576 =item C<@res> - used to capture output from actual C<eval>. 577 578 =item C<$otrace> - saved value of C<$trace>. 579 580 =item C<$osingle> - saved value of C<$single>. 581 582 =item C<$od> - saved value of C<$^D>. 583 584 =item C<$saved[0]> - saved value of C<$@>. 585 586 =item $\ - for output of C<$@> if there is an evaluation error. 587 588 =back 589 590 =head3 The problem of lexicals 591 592 The context of C<DB::eval()> presents us with some problems. Obviously, 593 we want to be 'sandboxed' away from the debugger's internals when we do 594 the eval, but we need some way to control how punctuation variables and 595 debugger globals are used. 596 597 We can't use local, because the code inside C<DB::eval> can see localized 598 variables; and we can't use C<my> either for the same reason. The code 599 in this routine compromises and uses C<my>. 600 601 After this routine is over, we don't have user code executing in the debugger's 602 context, so we can use C<my> freely. 603 604 =cut 605 606 ############################################## Begin lexical danger zone 607 608 # 'my' variables used here could leak into (that is, be visible in) 609 # the context that the code being evaluated is executing in. This means that 610 # the code could modify the debugger's variables. 611 # 612 # Fiddling with the debugger's context could be Bad. We insulate things as 613 # much as we can. 614 615 sub eval { 616 617 # 'my' would make it visible from user code 618 # but so does local! --tchrist 619 # Remember: this localizes @DB::res, not @main::res. 620 local @res; 621 { 622 623 # Try to keep the user code from messing with us. Save these so that 624 # even if the eval'ed code changes them, we can put them back again. 625 # Needed because the user could refer directly to the debugger's 626 # package globals (and any 'my' variables in this containing scope) 627 # inside the eval(), and we want to try to stay safe. 628 local $otrace = $trace; 629 local $osingle = $single; 630 local $od = $^D; 631 632 # Untaint the incoming eval() argument. 633 { ($evalarg) = $evalarg =~ /(.*)/s; } 634 635 # $usercontext built in DB::DB near the comment 636 # "set up the context for DB::eval ..." 637 # Evaluate and save any results. 638 @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug 639 640 # Restore those old values. 641 $trace = $otrace; 642 $single = $osingle; 643 $^D = $od; 644 } 645 646 # Save the current value of $@, and preserve it in the debugger's copy 647 # of the saved precious globals. 648 my $at = $@; 649 650 # Since we're only saving $@, we only have to localize the array element 651 # that it will be stored in. 652 local $saved[0]; # Preserve the old value of $@ 653 eval { &DB::save }; 654 655 # Now see whether we need to report an error back to the user. 656 if ($at) { 657 local $\ = ''; 658 print $OUT $at; 659 } 660 661 # Display as required by the caller. $onetimeDump and $onetimedumpDepth 662 # are package globals. 663 elsif ($onetimeDump) { 664 if ( $onetimeDump eq 'dump' ) { 665 local $option{dumpDepth} = $onetimedumpDepth 666 if defined $onetimedumpDepth; 667 dumpit( $OUT, \@res ); 668 } 669 elsif ( $onetimeDump eq 'methods' ) { 670 methods( $res[0] ); 671 } 672 } ## end elsif ($onetimeDump) 673 @res; 674 } ## end sub eval 675 676 ############################################## End lexical danger zone 677 678 # After this point it is safe to introduce lexicals. 679 # The code being debugged will be executing in its own context, and 680 # can't see the inside of the debugger. 681 # 682 # However, one should not overdo it: leave as much control from outside as 683 # possible. If you make something a lexical, it's not going to be addressable 684 # from outside the debugger even if you know its name. 685 686 # This file is automatically included if you do perl -d. 687 # It's probably not useful to include this yourself. 688 # 689 # Before venturing further into these twisty passages, it is 690 # wise to read the perldebguts man page or risk the ire of dragons. 691 # 692 # (It should be noted that perldebguts will tell you a lot about 693 # the underlying mechanics of how the debugger interfaces into the 694 # Perl interpreter, but not a lot about the debugger itself. The new 695 # comments in this code try to address this problem.) 696 697 # Note that no subroutine call is possible until &DB::sub is defined 698 # (for subroutines defined outside of the package DB). In fact the same is 699 # true if $deep is not defined. 700 701 # Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich) 702 703 # modified Perl debugger, to be run from Emacs in perldb-mode 704 # Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990 705 # Johan Vromans -- upgrade to 4.0 pl 10 706 # Ilya Zakharevich -- patches after 5.001 (and some before ;-) 707 708 # (We have made efforts to clarify the comments in the change log 709 # in other places; some of them may seem somewhat obscure as they 710 # were originally written, and explaining them away from the code 711 # in question seems conterproductive.. -JM) 712 713 ######################################################################## 714 # Changes: 0.94 715 # + A lot of things changed after 0.94. First of all, core now informs 716 # debugger about entry into XSUBs, overloaded operators, tied operations, 717 # BEGIN and END. Handy with `O f=2'. 718 # + This can make debugger a little bit too verbose, please be patient 719 # and report your problems promptly. 720 # + Now the option frame has 3 values: 0,1,2. XXX Document! 721 # + Note that if DESTROY returns a reference to the object (or object), 722 # the deletion of data may be postponed until the next function call, 723 # due to the need to examine the return value. 724 # 725 # Changes: 0.95 726 # + `v' command shows versions. 727 # 728 # Changes: 0.96 729 # + `v' command shows version of readline. 730 # primitive completion works (dynamic variables, subs for `b' and `l', 731 # options). Can `p %var' 732 # + Better help (`h <' now works). New commands <<, >>, {, {{. 733 # {dump|print}_trace() coded (to be able to do it from <<cmd). 734 # + `c sub' documented. 735 # + At last enough magic combined to stop after the end of debuggee. 736 # + !! should work now (thanks to Emacs bracket matching an extra 737 # `]' in a regexp is caught). 738 # + `L', `D' and `A' span files now (as documented). 739 # + Breakpoints in `require'd code are possible (used in `R'). 740 # + Some additional words on internal work of debugger. 741 # + `b load filename' implemented. 742 # + `b postpone subr' implemented. 743 # + now only `q' exits debugger (overwritable on $inhibit_exit). 744 # + When restarting debugger breakpoints/actions persist. 745 # + Buglet: When restarting debugger only one breakpoint/action per 746 # autoloaded function persists. 747 # 748 # Changes: 0.97: NonStop will not stop in at_exit(). 749 # + Option AutoTrace implemented. 750 # + Trace printed differently if frames are printed too. 751 # + new `inhibitExit' option. 752 # + printing of a very long statement interruptible. 753 # Changes: 0.98: New command `m' for printing possible methods 754 # + 'l -' is a synonym for `-'. 755 # + Cosmetic bugs in printing stack trace. 756 # + `frame' & 8 to print "expanded args" in stack trace. 757 # + Can list/break in imported subs. 758 # + new `maxTraceLen' option. 759 # + frame & 4 and frame & 8 granted. 760 # + new command `m' 761 # + nonstoppable lines do not have `:' near the line number. 762 # + `b compile subname' implemented. 763 # + Will not use $` any more. 764 # + `-' behaves sane now. 765 # Changes: 0.99: Completion for `f', `m'. 766 # + `m' will remove duplicate names instead of duplicate functions. 767 # + `b load' strips trailing whitespace. 768 # completion ignores leading `|'; takes into account current package 769 # when completing a subroutine name (same for `l'). 770 # Changes: 1.07: Many fixed by tchrist 13-March-2000 771 # BUG FIXES: 772 # + Added bare minimal security checks on perldb rc files, plus 773 # comments on what else is needed. 774 # + Fixed the ornaments that made "|h" completely unusable. 775 # They are not used in print_help if they will hurt. Strip pod 776 # if we're paging to less. 777 # + Fixed mis-formatting of help messages caused by ornaments 778 # to restore Larry's original formatting. 779 # + Fixed many other formatting errors. The code is still suboptimal, 780 # and needs a lot of work at restructuring. It's also misindented 781 # in many places. 782 # + Fixed bug where trying to look at an option like your pager 783 # shows "1". 784 # + Fixed some $? processing. Note: if you use csh or tcsh, you will 785 # lose. You should consider shell escapes not using their shell, 786 # or else not caring about detailed status. This should really be 787 # unified into one place, too. 788 # + Fixed bug where invisible trailing whitespace on commands hoses you, 789 # tricking Perl into thinking you weren't calling a debugger command! 790 # + Fixed bug where leading whitespace on commands hoses you. (One 791 # suggests a leading semicolon or any other irrelevant non-whitespace 792 # to indicate literal Perl code.) 793 # + Fixed bugs that ate warnings due to wrong selected handle. 794 # + Fixed a precedence bug on signal stuff. 795 # + Fixed some unseemly wording. 796 # + Fixed bug in help command trying to call perl method code. 797 # + Fixed to call dumpvar from exception handler. SIGPIPE killed us. 798 # ENHANCEMENTS: 799 # + Added some comments. This code is still nasty spaghetti. 800 # + Added message if you clear your pre/post command stacks which was 801 # very easy to do if you just typed a bare >, <, or {. (A command 802 # without an argument should *never* be a destructive action; this 803 # API is fundamentally screwed up; likewise option setting, which 804 # is equally buggered.) 805 # + Added command stack dump on argument of "?" for >, <, or {. 806 # + Added a semi-built-in doc viewer command that calls man with the 807 # proper %Config::Config path (and thus gets caching, man -k, etc), 808 # or else perldoc on obstreperous platforms. 809 # + Added to and rearranged the help information. 810 # + Detected apparent misuse of { ... } to declare a block; this used 811 # to work but now is a command, and mysteriously gave no complaint. 812 # 813 # Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com> 814 # BUG FIX: 815 # + This patch to perl5db.pl cleans up formatting issues on the help 816 # summary (h h) screen in the debugger. Mostly columnar alignment 817 # issues, plus converted the printed text to use all spaces, since 818 # tabs don't seem to help much here. 819 # 820 # Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu> 821 # Minor bugs corrected; 822 # + Support for auto-creation of new TTY window on startup, either 823 # unconditionally, or if started as a kid of another debugger session; 824 # + New `O'ption CreateTTY 825 # I<CreateTTY> bits control attempts to create a new TTY on events: 826 # 1: on fork() 827 # 2: debugger is started inside debugger 828 # 4: on startup 829 # + Code to auto-create a new TTY window on OS/2 (currently one 830 # extra window per session - need named pipes to have more...); 831 # + Simplified interface for custom createTTY functions (with a backward 832 # compatibility hack); now returns the TTY name to use; return of '' 833 # means that the function reset the I/O handles itself; 834 # + Better message on the semantic of custom createTTY function; 835 # + Convert the existing code to create a TTY into a custom createTTY 836 # function; 837 # + Consistent support for TTY names of the form "TTYin,TTYout"; 838 # + Switch line-tracing output too to the created TTY window; 839 # + make `b fork' DWIM with CORE::GLOBAL::fork; 840 # + High-level debugger API cmd_*(): 841 # cmd_b_load($filenamepart) # b load filenamepart 842 # cmd_b_line($lineno [, $cond]) # b lineno [cond] 843 # cmd_b_sub($sub [, $cond]) # b sub [cond] 844 # cmd_stop() # Control-C 845 # cmd_d($lineno) # d lineno (B) 846 # The cmd_*() API returns FALSE on failure; in this case it outputs 847 # the error message to the debugging output. 848 # + Low-level debugger API 849 # break_on_load($filename) # b load filename 850 # @files = report_break_on_load() # List files with load-breakpoints 851 # breakable_line_in_filename($name, $from [, $to]) 852 # # First breakable line in the 853 # # range $from .. $to. $to defaults 854 # # to $from, and may be less than 855 # # $to 856 # breakable_line($from [, $to]) # Same for the current file 857 # break_on_filename_line($name, $lineno [, $cond]) 858 # # Set breakpoint,$cond defaults to 859 # # 1 860 # break_on_filename_line_range($name, $from, $to [, $cond]) 861 # # As above, on the first 862 # # breakable line in range 863 # break_on_line($lineno [, $cond]) # As above, in the current file 864 # break_subroutine($sub [, $cond]) # break on the first breakable line 865 # ($name, $from, $to) = subroutine_filename_lines($sub) 866 # # The range of lines of the text 867 # The low-level API returns TRUE on success, and die()s on failure. 868 # 869 # Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu> 870 # BUG FIXES: 871 # + Fixed warnings generated by "perl -dWe 42" 872 # + Corrected spelling errors 873 # + Squeezed Help (h) output into 80 columns 874 # 875 # Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com> 876 # + Made "x @INC" work like it used to 877 # 878 # Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu> 879 # + Fixed warnings generated by "O" (Show debugger options) 880 # + Fixed warnings generated by "p 42" (Print expression) 881 # Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com 882 # + Added windowSize option 883 # Changes: 1.14: Oct 9, 2001 multiple 884 # + Clean up after itself on VMS (Charles Lane in 12385) 885 # + Adding "@ file" syntax (Peter Scott in 12014) 886 # + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457) 887 # + $^S and other debugger fixes (Ilya Zakharevich in 11120) 888 # + Forgot a my() declaration (Ilya Zakharevich in 11085) 889 # Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com> 890 # + Updated 1.14 change log 891 # + Added *dbline explainatory comments 892 # + Mentioning perldebguts man page 893 # Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com> 894 # + $onetimeDump improvements 895 # Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net> 896 # Moved some code to cmd_[.]()'s for clarity and ease of handling, 897 # rationalised the following commands and added cmd_wrapper() to 898 # enable switching between old and frighteningly consistent new 899 # behaviours for diehards: 'o CommandSet=pre580' (sigh...) 900 # a(add), A(del) # action expr (added del by line) 901 # + b(add), B(del) # break [line] (was b,D) 902 # + w(add), W(del) # watch expr (was W,W) 903 # # added del by expr 904 # + h(summary), h h(long) # help (hh) (was h h,h) 905 # + m(methods), M(modules) # ... (was m,v) 906 # + o(option) # lc (was O) 907 # + v(view code), V(view Variables) # ... (was w,V) 908 # Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net> 909 # + fixed missing cmd_O bug 910 # Changes: 1.19: Mar 29, 2002 Spider Boardman 911 # + Added missing local()s -- DB::DB is called recursively. 912 # Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net> 913 # + pre'n'post commands no longer trashed with no args 914 # + watch val joined out of eval() 915 # Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org> 916 # + Added comments and reformatted source. No bug fixes/enhancements. 917 # + Includes cleanup by Robin Barker and Jarkko Hietaniemi. 918 # Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU> 919 # + Flush stdout/stderr before the debugger prompt is printed. 920 # Changes: 1.23: Dec 21, 2003 Dominique Quatravaux 921 # + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug") 922 # Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net> 923 # + Added command to save all debugger commands for sourcing later. 924 # + Added command to display parent inheritance tree of given class. 925 # + Fixed minor newline in history bug. 926 # Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net> 927 # + Fixed option bug (setting invalid options + not recognising valid short forms) 928 # Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net> 929 # + unfork the 5.8.x and 5.9.x debuggers. 930 # + whitespace and assertions call cleanup across versions 931 # + H * deletes (resets) history 932 # + i now handles Class + blessed objects 933 # Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net> 934 # + updated pod page references - clunky. 935 # + removed windowid restriction for forking into an xterm. 936 # + more whitespace again. 937 # + wrapped restart and enabled rerun [-n] (go back n steps) command. 938 # Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net> 939 # + Added threads support (inc. e and E commands) 940 # Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com> 941 # + Added macosx_get_fork_TTY support 942 # Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org> 943 # + Added HistFile, HistSize 944 ######################################################################## 945 946 =head1 DEBUGGER INITIALIZATION 947 948 The debugger starts up in phases. 949 950 =head2 BASIC SETUP 951 952 First, it initializes the environment it wants to run in: turning off 953 warnings during its own compilation, defining variables which it will need 954 to avoid warnings later, setting itself up to not exit when the program 955 terminates, and defaulting to printing return values for the C<r> command. 956 957 =cut 958 959 # Needed for the statement after exec(): 960 # 961 # This BEGIN block is simply used to switch off warnings during debugger 962 # compiliation. Probably it would be better practice to fix the warnings, 963 # but this is how it's done at the moment. 964 965 BEGIN { 966 $ini_warn = $^W; 967 $^W = 0; 968 } # Switch compilation warnings off until another BEGIN. 969 970 local ($^W) = 0; # Switch run-time warnings off during init. 971 972 =head2 THREADS SUPPORT 973 974 If we are running under a threaded Perl, we require threads and threads::shared 975 if the environment variable C<PERL5DB_THREADED> is set, to enable proper 976 threaded debugger control. C<-dt> can also be used to set this. 977 978 Each new thread will be announced and the debugger prompt will always inform 979 you of each new thread created. It will also indicate the thread id in which 980 we are currently running within the prompt like this: 981 982 [tid] DB<$i> 983 984 Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger 985 command prompt. The prompt will show: C<[0]> when running under threads, but 986 not actually in a thread. C<[tid]> is consistent with C<gdb> usage. 987 988 While running under threads, when you set or delete a breakpoint (etc.), this 989 will apply to all threads, not just the currently running one. When you are 990 in a currently executing thread, you will stay there until it completes. With 991 the current implementation it is not currently possible to hop from one thread 992 to another. 993 994 The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>. 995 996 Note that threading support was built into the debugger as of Perl version 997 C<5.8.6> and debugger version C<1.2.8>. 998 999 =cut 1000 1001 BEGIN { 1002 # ensure we can share our non-threaded variables or no-op 1003 if ($ENV{PERL5DB_THREADED}) { 1004 require threads; 1005 require threads::shared; 1006 import threads::shared qw(share); 1007 $DBGR; 1008 share(\$DBGR); 1009 lock($DBGR); 1010 print "Threads support enabled\n"; 1011 } else { 1012 *lock = sub(*) {}; 1013 *share = sub(*) {}; 1014 } 1015 } 1016 1017 # This would probably be better done with "use vars", but that wasn't around 1018 # when this code was originally written. (Neither was "use strict".) And on 1019 # the principle of not fiddling with something that was working, this was 1020 # left alone. 1021 warn( # Do not ;-) 1022 # These variables control the execution of 'dumpvar.pl'. 1023 $dumpvar::hashDepth, 1024 $dumpvar::arrayDepth, 1025 $dumpvar::dumpDBFiles, 1026 $dumpvar::dumpPackages, 1027 $dumpvar::quoteHighBit, 1028 $dumpvar::printUndef, 1029 $dumpvar::globPrint, 1030 $dumpvar::usageOnly, 1031 1032 # used to save @ARGV and extract any debugger-related flags. 1033 @ARGS, 1034 1035 # used to control die() reporting in diesignal() 1036 $Carp::CarpLevel, 1037 1038 # used to prevent multiple entries to diesignal() 1039 # (if for instance diesignal() itself dies) 1040 $panic, 1041 1042 # used to prevent the debugger from running nonstop 1043 # after a restart 1044 $second_time, 1045 ) 1046 if 0; 1047 1048 foreach my $k (keys (%INC)) { 1049 &share(\$main::{'_<'.$filename}); 1050 }; 1051 1052 # Command-line + PERLLIB: 1053 # Save the contents of @INC before they are modified elsewhere. 1054 @ini_INC = @INC; 1055 1056 # This was an attempt to clear out the previous values of various 1057 # trapped errors. Apparently it didn't help. XXX More info needed! 1058 # $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?! 1059 1060 # We set these variables to safe values. We don't want to blindly turn 1061 # off warnings, because other packages may still want them. 1062 $trace = $signal = $single = 0; # Uninitialized warning suppression 1063 # (local $^W cannot help - other packages!). 1064 1065 # Default to not exiting when program finishes; print the return 1066 # value when the 'r' command is used to return from a subroutine. 1067 $inhibit_exit = $option{PrintRet} = 1; 1068 1069 =head1 OPTION PROCESSING 1070 1071 The debugger's options are actually spread out over the debugger itself and 1072 C<dumpvar.pl>; some of these are variables to be set, while others are 1073 subs to be called with a value. To try to make this a little easier to 1074 manage, the debugger uses a few data structures to define what options 1075 are legal and how they are to be processed. 1076 1077 First, the C<@options> array defines the I<names> of all the options that 1078 are to be accepted. 1079 1080 =cut 1081 1082 @options = qw( 1083 CommandSet HistFile HistSize 1084 hashDepth arrayDepth dumpDepth 1085 DumpDBFiles DumpPackages DumpReused 1086 compactDump veryCompact quote 1087 HighBit undefPrint globPrint 1088 PrintRet UsageOnly frame 1089 AutoTrace TTY noTTY 1090 ReadLine NonStop LineInfo 1091 maxTraceLen recallCommand ShellBang 1092 pager tkRunning ornaments 1093 signalLevel warnLevel dieLevel 1094 inhibit_exit ImmediateStop bareStringify 1095 CreateTTY RemotePort windowSize 1096 DollarCaretP 1097 ); 1098 1099 @RememberOnROptions = qw(DollarCaretP); 1100 1101 =pod 1102 1103 Second, C<optionVars> lists the variables that each option uses to save its 1104 state. 1105 1106 =cut 1107 1108 %optionVars = ( 1109 hashDepth => \$dumpvar::hashDepth, 1110 arrayDepth => \$dumpvar::arrayDepth, 1111 CommandSet => \$CommandSet, 1112 DumpDBFiles => \$dumpvar::dumpDBFiles, 1113 DumpPackages => \$dumpvar::dumpPackages, 1114 DumpReused => \$dumpvar::dumpReused, 1115 HighBit => \$dumpvar::quoteHighBit, 1116 undefPrint => \$dumpvar::printUndef, 1117 globPrint => \$dumpvar::globPrint, 1118 UsageOnly => \$dumpvar::usageOnly, 1119 CreateTTY => \$CreateTTY, 1120 bareStringify => \$dumpvar::bareStringify, 1121 frame => \$frame, 1122 AutoTrace => \$trace, 1123 inhibit_exit => \$inhibit_exit, 1124 maxTraceLen => \$maxtrace, 1125 ImmediateStop => \$ImmediateStop, 1126 RemotePort => \$remoteport, 1127 windowSize => \$window, 1128 HistFile => \$histfile, 1129 HistSize => \$histsize, 1130 ); 1131 1132 =pod 1133 1134 Third, C<%optionAction> defines the subroutine to be called to process each 1135 option. 1136 1137 =cut 1138 1139 %optionAction = ( 1140 compactDump => \&dumpvar::compactDump, 1141 veryCompact => \&dumpvar::veryCompact, 1142 quote => \&dumpvar::quote, 1143 TTY => \&TTY, 1144 noTTY => \&noTTY, 1145 ReadLine => \&ReadLine, 1146 NonStop => \&NonStop, 1147 LineInfo => \&LineInfo, 1148 recallCommand => \&recallCommand, 1149 ShellBang => \&shellBang, 1150 pager => \&pager, 1151 signalLevel => \&signalLevel, 1152 warnLevel => \&warnLevel, 1153 dieLevel => \&dieLevel, 1154 tkRunning => \&tkRunning, 1155 ornaments => \&ornaments, 1156 RemotePort => \&RemotePort, 1157 DollarCaretP => \&DollarCaretP, 1158 ); 1159 1160 =pod 1161 1162 Last, the C<%optionRequire> notes modules that must be C<require>d if an 1163 option is used. 1164 1165 =cut 1166 1167 # Note that this list is not complete: several options not listed here 1168 # actually require that dumpvar.pl be loaded for them to work, but are 1169 # not in the table. A subsequent patch will correct this problem; for 1170 # the moment, we're just recommenting, and we are NOT going to change 1171 # function. 1172 %optionRequire = ( 1173 compactDump => 'dumpvar.pl', 1174 veryCompact => 'dumpvar.pl', 1175 quote => 'dumpvar.pl', 1176 ); 1177 1178 =pod 1179 1180 There are a number of initialization-related variables which can be set 1181 by putting code to set them in a BEGIN block in the C<PERL5DB> environment 1182 variable. These are: 1183 1184 =over 4 1185 1186 =item C<$rl> - readline control XXX needs more explanation 1187 1188 =item C<$warnLevel> - whether or not debugger takes over warning handling 1189 1190 =item C<$dieLevel> - whether or not debugger takes over die handling 1191 1192 =item C<$signalLevel> - whether or not debugger takes over signal handling 1193 1194 =item C<$pre> - preprompt actions (array reference) 1195 1196 =item C<$post> - postprompt actions (array reference) 1197 1198 =item C<$pretype> 1199 1200 =item C<$CreateTTY> - whether or not to create a new TTY for this debugger 1201 1202 =item C<$CommandSet> - which command set to use (defaults to new, documented set) 1203 1204 =back 1205 1206 =cut 1207 1208 # These guys may be defined in $ENV{PERL5DB} : 1209 $rl = 1 unless defined $rl; 1210 $warnLevel = 1 unless defined $warnLevel; 1211 $dieLevel = 1 unless defined $dieLevel; 1212 $signalLevel = 1 unless defined $signalLevel; 1213 $pre = [] unless defined $pre; 1214 $post = [] unless defined $post; 1215 $pretype = [] unless defined $pretype; 1216 $CreateTTY = 3 unless defined $CreateTTY; 1217 $CommandSet = '580' unless defined $CommandSet; 1218 1219 share($rl); 1220 share($warnLevel); 1221 share($dieLevel); 1222 share($signalLevel); 1223 share($pre); 1224 share($post); 1225 share($pretype); 1226 share($rl); 1227 share($CreateTTY); 1228 share($CommandSet); 1229 1230 =pod 1231 1232 The default C<die>, C<warn>, and C<signal> handlers are set up. 1233 1234 =cut 1235 1236 warnLevel($warnLevel); 1237 dieLevel($dieLevel); 1238 signalLevel($signalLevel); 1239 1240 =pod 1241 1242 The pager to be used is needed next. We try to get it from the 1243 environment first. If it's not defined there, we try to find it in 1244 the Perl C<Config.pm>. If it's not there, we default to C<more>. We 1245 then call the C<pager()> function to save the pager name. 1246 1247 =cut 1248 1249 # This routine makes sure $pager is set up so that '|' can use it. 1250 pager( 1251 1252 # If PAGER is defined in the environment, use it. 1253 defined $ENV{PAGER} 1254 ? $ENV{PAGER} 1255 1256 # If not, see if Config.pm defines it. 1257 : eval { require Config } 1258 && defined $Config::Config{pager} 1259 ? $Config::Config{pager} 1260 1261 # If not, fall back to 'more'. 1262 : 'more' 1263 ) 1264 unless defined $pager; 1265 1266 =pod 1267 1268 We set up the command to be used to access the man pages, the command 1269 recall character (C<!> unless otherwise defined) and the shell escape 1270 character (C<!> unless otherwise defined). Yes, these do conflict, and 1271 neither works in the debugger at the moment. 1272 1273 =cut 1274 1275 setman(); 1276 1277 # Set up defaults for command recall and shell escape (note: 1278 # these currently don't work in linemode debugging). 1279 &recallCommand("!") unless defined $prc; 1280 &shellBang("!") unless defined $psh; 1281 1282 =pod 1283 1284 We then set up the gigantic string containing the debugger help. 1285 We also set the limit on the number of arguments we'll display during a 1286 trace. 1287 1288 =cut 1289 1290 sethelp(); 1291 1292 # If we didn't get a default for the length of eval/stack trace args, 1293 # set it here. 1294 $maxtrace = 400 unless defined $maxtrace; 1295 1296 =head2 SETTING UP THE DEBUGGER GREETING 1297 1298 The debugger I<greeting> helps to inform the user how many debuggers are 1299 running, and whether the current debugger is the primary or a child. 1300 1301 If we are the primary, we just hang onto our pid so we'll have it when 1302 or if we start a child debugger. If we are a child, we'll set things up 1303 so we'll have a unique greeting and so the parent will give us our own 1304 TTY later. 1305 1306 We save the current contents of the C<PERLDB_PIDS> environment variable 1307 because we mess around with it. We'll also need to hang onto it because 1308 we'll need it if we restart. 1309 1310 Child debuggers make a label out of the current PID structure recorded in 1311 PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY 1312 yet so the parent will give them one later via C<resetterm()>. 1313 1314 =cut 1315 1316 # Save the current contents of the environment; we're about to 1317 # much with it. We'll need this if we have to restart. 1318 $ini_pids = $ENV{PERLDB_PIDS}; 1319 1320 if ( defined $ENV{PERLDB_PIDS} ) { 1321 1322 # We're a child. Make us a label out of the current PID structure 1323 # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having 1324 # a term yet so the parent will give us one later via resetterm(). 1325 1326 my $env_pids = $ENV{PERLDB_PIDS}; 1327 $pids = "[$env_pids]"; 1328 1329 # Unless we are on OpenVMS, all programs under the DCL shell run under 1330 # the same PID. 1331 1332 if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) { 1333 $term_pid = $$; 1334 } 1335 else { 1336 $ENV{PERLDB_PIDS} .= "->$$"; 1337 $term_pid = -1; 1338 } 1339 1340 } ## end if (defined $ENV{PERLDB_PIDS... 1341 else { 1342 1343 # We're the parent PID. Initialize PERLDB_PID in case we end up with a 1344 # child debugger, and mark us as the parent, so we'll know to set up 1345 # more TTY's is we have to. 1346 $ENV{PERLDB_PIDS} = "$$"; 1347 $pids = "[pid=$$]"; 1348 $term_pid = $$; 1349 } 1350 1351 $pidprompt = ''; 1352 1353 # Sets up $emacs as a synonym for $slave_editor. 1354 *emacs = $slave_editor if $slave_editor; # May be used in afterinit()... 1355 1356 =head2 READING THE RC FILE 1357 1358 The debugger will read a file of initialization options if supplied. If 1359 running interactively, this is C<.perldb>; if not, it's C<perldb.ini>. 1360 1361 =cut 1362 1363 # As noted, this test really doesn't check accurately that the debugger 1364 # is running at a terminal or not. 1365 1366 if ( -e "/dev/tty" ) { # this is the wrong metric! 1367 $rcfile = ".perldb"; 1368 } 1369 else { 1370 $rcfile = "perldb.ini"; 1371 } 1372 1373 =pod 1374 1375 The debugger does a safety test of the file to be read. It must be owned 1376 either by the current user or root, and must only be writable by the owner. 1377 1378 =cut 1379 1380 # This wraps a safety test around "do" to read and evaluate the init file. 1381 # 1382 # This isn't really safe, because there's a race 1383 # between checking and opening. The solution is to 1384 # open and fstat the handle, but then you have to read and 1385 # eval the contents. But then the silly thing gets 1386 # your lexical scope, which is unfortunate at best. 1387 sub safe_do { 1388 my $file = shift; 1389 1390 # Just exactly what part of the word "CORE::" don't you understand? 1391 local $SIG{__WARN__}; 1392 local $SIG{__DIE__}; 1393 1394 unless ( is_safe_file($file) ) { 1395 CORE::warn <<EO_GRIPE; 1396 perldb: Must not source insecure rcfile $file. 1397 You or the superuser must be the owner, and it must not 1398 be writable by anyone but its owner. 1399 EO_GRIPE 1400 return; 1401 } ## end unless (is_safe_file($file... 1402 1403 do $file; 1404 CORE::warn("perldb: couldn't parse $file: $@") if $@; 1405 } ## end sub safe_do 1406 1407 # This is the safety test itself. 1408 # 1409 # Verifies that owner is either real user or superuser and that no 1410 # one but owner may write to it. This function is of limited use 1411 # when called on a path instead of upon a handle, because there are 1412 # no guarantees that filename (by dirent) whose file (by ino) is 1413 # eventually accessed is the same as the one tested. 1414 # Assumes that the file's existence is not in doubt. 1415 sub is_safe_file { 1416 my $path = shift; 1417 stat($path) || return; # mysteriously vaporized 1418 my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_); 1419 1420 return 0 if $uid != 0 && $uid != $<; 1421 return 0 if $mode & 022; 1422 return 1; 1423 } ## end sub is_safe_file 1424 1425 # If the rcfile (whichever one we decided was the right one to read) 1426 # exists, we safely do it. 1427 if ( -f $rcfile ) { 1428 safe_do("./$rcfile"); 1429 } 1430 1431 # If there isn't one here, try the user's home directory. 1432 elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) { 1433 safe_do("$ENV{HOME}/$rcfile"); 1434 } 1435 1436 # Else try the login directory. 1437 elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) { 1438 safe_do("$ENV{LOGDIR}/$rcfile"); 1439 } 1440 1441 # If the PERLDB_OPTS variable has options in it, parse those out next. 1442 if ( defined $ENV{PERLDB_OPTS} ) { 1443 parse_options( $ENV{PERLDB_OPTS} ); 1444 } 1445 1446 =pod 1447 1448 The last thing we do during initialization is determine which subroutine is 1449 to be used to obtain a new terminal when a new debugger is started. Right now, 1450 the debugger only handles X Windows, OS/2, and Mac OS X (darwin). 1451 1452 =cut 1453 1454 # Set up the get_fork_TTY subroutine to be aliased to the proper routine. 1455 # Works if you're running an xterm or xterm-like window, or you're on 1456 # OS/2, or on Mac OS X. This may need some expansion. 1457 1458 if (not defined &get_fork_TTY) # only if no routine exists 1459 { 1460 if (defined $ENV{TERM} # If we know what kind 1461 # of terminal this is, 1462 and $ENV{TERM} eq 'xterm' # and it's an xterm, 1463 and defined $ENV{DISPLAY} # and what display it's on, 1464 ) 1465 { 1466 *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version 1467 } 1468 elsif ( $^O eq 'os2' ) { # If this is OS/2, 1469 *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version 1470 } 1471 elsif ( $^O eq 'darwin' # If this is Mac OS X 1472 and defined $ENV{TERM_PROGRAM} # and we're running inside 1473 and $ENV{TERM_PROGRAM} 1474 eq 'Apple_Terminal' # Terminal.app 1475 ) 1476 { 1477 *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version 1478 } 1479 } ## end if (not defined &get_fork_TTY... 1480 1481 # untaint $^O, which may have been tainted by the last statement. 1482 # see bug [perl #24674] 1483 $^O =~ m/^(.*)\z/; 1484 $^O = $1; 1485 1486 # Here begin the unreadable code. It needs fixing. 1487 1488 =head2 RESTART PROCESSING 1489 1490 This section handles the restart command. When the C<R> command is invoked, it 1491 tries to capture all of the state it can into environment variables, and 1492 then sets C<PERLDB_RESTART>. When we start executing again, we check to see 1493 if C<PERLDB_RESTART> is there; if so, we reload all the information that 1494 the R command stuffed into the environment variables. 1495 1496 PERLDB_RESTART - flag only, contains no restart data itself. 1497 PERLDB_HIST - command history, if it's available 1498 PERLDB_ON_LOAD - breakpoints set by the rc file 1499 PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions 1500 PERLDB_VISITED - files that had breakpoints 1501 PERLDB_FILE_... - breakpoints for a file 1502 PERLDB_OPT - active options 1503 PERLDB_INC - the original @INC 1504 PERLDB_PRETYPE - preprompt debugger actions 1505 PERLDB_PRE - preprompt Perl code 1506 PERLDB_POST - post-prompt Perl code 1507 PERLDB_TYPEAHEAD - typeahead captured by readline() 1508 1509 We chug through all these variables and plug the values saved in them 1510 back into the appropriate spots in the debugger. 1511 1512 =cut 1513 1514 if ( exists $ENV{PERLDB_RESTART} ) { 1515 1516 # We're restarting, so we don't need the flag that says to restart anymore. 1517 delete $ENV{PERLDB_RESTART}; 1518 1519 # $restart = 1; 1520 @hist = get_list('PERLDB_HIST'); 1521 %break_on_load = get_list("PERLDB_ON_LOAD"); 1522 %postponed = get_list("PERLDB_POSTPONE"); 1523 1524 share(@hist); 1525 share(@truehist); 1526 share(%break_on_load); 1527 share(%postponed); 1528 1529 # restore breakpoints/actions 1530 my @had_breakpoints = get_list("PERLDB_VISITED"); 1531 for ( 0 .. $#had_breakpoints ) { 1532 my %pf = get_list("PERLDB_FILE_$_"); 1533 $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf; 1534 } 1535 1536 # restore options 1537 my %opt = get_list("PERLDB_OPT"); 1538 my ( $opt, $val ); 1539 while ( ( $opt, $val ) = each %opt ) { 1540 $val =~ s/[\\\']/\\$1/g; 1541 parse_options("$opt'$val'"); 1542 } 1543 1544 # restore original @INC 1545 @INC = get_list("PERLDB_INC"); 1546 @ini_INC = @INC; 1547 1548 # return pre/postprompt actions and typeahead buffer 1549 $pretype = [ get_list("PERLDB_PRETYPE") ]; 1550 $pre = [ get_list("PERLDB_PRE") ]; 1551 $post = [ get_list("PERLDB_POST") ]; 1552 @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead ); 1553 } ## end if (exists $ENV{PERLDB_RESTART... 1554 1555 =head2 SETTING UP THE TERMINAL 1556 1557 Now, we'll decide how the debugger is going to interact with the user. 1558 If there's no TTY, we set the debugger to run non-stop; there's not going 1559 to be anyone there to enter commands. 1560 1561 =cut 1562 1563 if ($notty) { 1564 $runnonstop = 1; 1565 share($runnonstop); 1566 } 1567 1568 =pod 1569 1570 If there is a TTY, we have to determine who it belongs to before we can 1571 proceed. If this is a slave editor or graphical debugger (denoted by 1572 the first command-line switch being '-emacs'), we shift this off and 1573 set C<$rl> to 0 (XXX ostensibly to do straight reads). 1574 1575 =cut 1576 1577 else { 1578 1579 # Is Perl being run from a slave editor or graphical debugger? 1580 # If so, don't use readline, and set $slave_editor = 1. 1581 $slave_editor = 1582 ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) ); 1583 $rl = 0, shift(@main::ARGV) if $slave_editor; 1584 1585 #require Term::ReadLine; 1586 1587 =pod 1588 1589 We then determine what the console should be on various systems: 1590 1591 =over 4 1592 1593 =item * Cygwin - We use C<stdin> instead of a separate device. 1594 1595 =cut 1596 1597 if ( $^O eq 'cygwin' ) { 1598 1599 # /dev/tty is binary. use stdin for textmode 1600 undef $console; 1601 } 1602 1603 =item * Unix - use C</dev/tty>. 1604 1605 =cut 1606 1607 elsif ( -e "/dev/tty" ) { 1608 $console = "/dev/tty"; 1609 } 1610 1611 =item * Windows or MSDOS - use C<con>. 1612 1613 =cut 1614 1615 elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) { 1616 $console = "con"; 1617 } 1618 1619 =item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev: 1620 Console> if not. 1621 1622 Note that Mac OS X returns C<darwin>, not C<MacOS>. Also note that the debugger doesn't do anything special for C<darwin>. Maybe it should. 1623 1624 =cut 1625 1626 elsif ( $^O eq 'MacOS' ) { 1627 if ( $MacPerl::Version !~ /MPW/ ) { 1628 $console = 1629 "Dev:Console:Perl Debug"; # Separate window for application 1630 } 1631 else { 1632 $console = "Dev:Console"; 1633 } 1634 } ## end elsif ($^O eq 'MacOS') 1635 1636 =item * VMS - use C<sys$command>. 1637 1638 =cut 1639 1640 else { 1641 1642 # everything else is ... 1643 $console = "sys\$command"; 1644 } 1645 1646 =pod 1647 1648 =back 1649 1650 Several other systems don't use a specific console. We C<undef $console> 1651 for those (Windows using a slave editor/graphical debugger, NetWare, OS/2 1652 with a slave editor, Epoc). 1653 1654 =cut 1655 1656 if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) { 1657 1658 # /dev/tty is binary. use stdin for textmode 1659 $console = undef; 1660 } 1661 1662 if ( $^O eq 'NetWare' ) { 1663 1664 # /dev/tty is binary. use stdin for textmode 1665 $console = undef; 1666 } 1667 1668 # In OS/2, we need to use STDIN to get textmode too, even though 1669 # it pretty much looks like Unix otherwise. 1670 if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) ) 1671 { # In OS/2 1672 $console = undef; 1673 } 1674 1675 # EPOC also falls into the 'got to use STDIN' camp. 1676 if ( $^O eq 'epoc' ) { 1677 $console = undef; 1678 } 1679 1680 =pod 1681 1682 If there is a TTY hanging around from a parent, we use that as the console. 1683 1684 =cut 1685 1686 $console = $tty if defined $tty; 1687 1688 =head2 SOCKET HANDLING 1689 1690 The debugger is capable of opening a socket and carrying out a debugging 1691 session over the socket. 1692 1693 If C<RemotePort> was defined in the options, the debugger assumes that it 1694 should try to start a debugging session on that port. It builds the socket 1695 and then tries to connect the input and output filehandles to it. 1696 1697 =cut 1698 1699 # Handle socket stuff. 1700 1701 if ( defined $remoteport ) { 1702 1703 # If RemotePort was defined in the options, connect input and output 1704 # to the socket. 1705 require IO::Socket; 1706 $OUT = new IO::Socket::INET( 1707 Timeout => '10', 1708 PeerAddr => $remoteport, 1709 Proto => 'tcp', 1710 ); 1711 if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; } 1712 $IN = $OUT; 1713 } ## end if (defined $remoteport) 1714 1715 =pod 1716 1717 If no C<RemotePort> was defined, and we want to create a TTY on startup, 1718 this is probably a situation where multiple debuggers are running (for example, 1719 a backticked command that starts up another debugger). We create a new IN and 1720 OUT filehandle, and do the necessary mojo to create a new TTY if we know how 1721 and if we can. 1722 1723 =cut 1724 1725 # Non-socket. 1726 else { 1727 1728 # Two debuggers running (probably a system or a backtick that invokes 1729 # the debugger itself under the running one). create a new IN and OUT 1730 # filehandle, and do the necessary mojo to create a new tty if we 1731 # know how, and we can. 1732 create_IN_OUT(4) if $CreateTTY & 4; 1733 if ($console) { 1734 1735 # If we have a console, check to see if there are separate ins and 1736 # outs to open. (They are assumed identical if not.) 1737 1738 my ( $i, $o ) = split /,/, $console; 1739 $o = $i unless defined $o; 1740 1741 # read/write on in, or just read, or read on STDIN. 1742 open( IN, "+<$i" ) 1743 || open( IN, "<$i" ) 1744 || open( IN, "<&STDIN" ); 1745 1746 # read/write/create/clobber out, or write/create/clobber out, 1747 # or merge with STDERR, or merge with STDOUT. 1748 open( OUT, "+>$o" ) 1749 || open( OUT, ">$o" ) 1750 || open( OUT, ">&STDERR" ) 1751 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout 1752 1753 } ## end if ($console) 1754 elsif ( not defined $console ) { 1755 1756 # No console. Open STDIN. 1757 open( IN, "<&STDIN" ); 1758 1759 # merge with STDERR, or with STDOUT. 1760 open( OUT, ">&STDERR" ) 1761 || open( OUT, ">&STDOUT" ); # so we don't dongle stdout 1762 $console = 'STDIN/OUT'; 1763 } ## end elsif (not defined $console) 1764 1765 # Keep copies of the filehandles so that when the pager runs, it 1766 # can close standard input without clobbering ours. 1767 $IN = \*IN, $OUT = \*OUT if $console or not defined $console; 1768 } ## end elsif (from if(defined $remoteport)) 1769 1770 # Unbuffer DB::OUT. We need to see responses right away. 1771 my $previous = select($OUT); 1772 $| = 1; # for DB::OUT 1773 select($previous); 1774 1775 # Line info goes to debugger output unless pointed elsewhere. 1776 # Pointing elsewhere makes it possible for slave editors to 1777 # keep track of file and position. We have both a filehandle 1778 # and a I/O description to keep track of. 1779 $LINEINFO = $OUT unless defined $LINEINFO; 1780 $lineinfo = $console unless defined $lineinfo; 1781 # share($LINEINFO); # <- unable to share globs 1782 share($lineinfo); # 1783 1784 =pod 1785 1786 To finish initialization, we show the debugger greeting, 1787 and then call the C<afterinit()> subroutine if there is one. 1788 1789 =cut 1790 1791 # Show the debugger greeting. 1792 $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/; 1793 unless ($runnonstop) { 1794 local $\ = ''; 1795 local $, = ''; 1796 if ( $term_pid eq '-1' ) { 1797 print $OUT "\nDaughter DB session started...\n"; 1798 } 1799 else { 1800 print $OUT "\nLoading DB routines from $header\n"; 1801 print $OUT ( 1802 "Editor support ", 1803 $slave_editor ? "enabled" : "available", ".\n" 1804 ); 1805 print $OUT 1806 "\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n"; 1807 } ## end else [ if ($term_pid eq '-1') 1808 } ## end unless ($runnonstop) 1809 } ## end else [ if ($notty) 1810 1811 # XXX This looks like a bug to me. 1812 # Why copy to @ARGS and then futz with @args? 1813 @ARGS = @ARGV; 1814 for (@args) { 1815 # Make sure backslashes before single quotes are stripped out, and 1816 # keep args unless they are numeric (XXX why?) 1817 # s/\'/\\\'/g; # removed while not justified understandably 1818 # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto 1819 } 1820 1821 # If there was an afterinit() sub defined, call it. It will get 1822 # executed in our scope, so it can fiddle with debugger globals. 1823 if ( defined &afterinit ) { # May be defined in $rcfile 1824 &afterinit(); 1825 } 1826 1827 # Inform us about "Stack dump during die enabled ..." in dieLevel(). 1828 $I_m_init = 1; 1829 1830 ############################################################ Subroutines 1831 1832 =head1 SUBROUTINES 1833 1834 =head2 DB 1835 1836 This gigantic subroutine is the heart of the debugger. Called before every 1837 statement, its job is to determine if a breakpoint has been reached, and 1838 stop if so; read commands from the user, parse them, and execute 1839 them, and hen send execution off to the next statement. 1840 1841 Note that the order in which the commands are processed is very important; 1842 some commands earlier in the loop will actually alter the C<$cmd> variable 1843 to create other commands to be executed later. This is all highly I<optimized> 1844 but can be confusing. Check the comments for each C<$cmd ... && do {}> to 1845 see what's happening in any given command. 1846 1847 =cut 1848 1849 sub DB { 1850 1851 # lock the debugger and get the thread id for the prompt 1852 lock($DBGR); 1853 my $tid; 1854 if ($ENV{PERL5DB_THREADED}) { 1855 $tid = eval { "[".threads->tid."]" }; 1856 } 1857 1858 # Check for whether we should be running continuously or not. 1859 # _After_ the perl program is compiled, $single is set to 1: 1860 if ( $single and not $second_time++ ) { 1861 1862 # Options say run non-stop. Run until we get an interrupt. 1863 if ($runnonstop) { # Disable until signal 1864 # If there's any call stack in place, turn off single 1865 # stepping into subs throughout the stack. 1866 for ( $i = 0 ; $i <= $stack_depth ; ) { 1867 $stack[ $i++ ] &= ~1; 1868 } 1869 1870 # And we are now no longer in single-step mode. 1871 $single = 0; 1872 1873 # If we simply returned at this point, we wouldn't get 1874 # the trace info. Fall on through. 1875 # return; 1876 } ## end if ($runnonstop) 1877 1878 elsif ($ImmediateStop) { 1879 1880 # We are supposed to stop here; XXX probably a break. 1881 $ImmediateStop = 0; # We've processed it; turn it off 1882 $signal = 1; # Simulate an interrupt to force 1883 # us into the command loop 1884 } 1885 } ## end if ($single and not $second_time... 1886 1887 # If we're in single-step mode, or an interrupt (real or fake) 1888 # has occurred, turn off non-stop mode. 1889 $runnonstop = 0 if $single or $signal; 1890 1891 # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W. 1892 # The code being debugged may have altered them. 1893 &save; 1894 1895 # Since DB::DB gets called after every line, we can use caller() to 1896 # figure out where we last were executing. Sneaky, eh? This works because 1897 # caller is returning all the extra information when called from the 1898 # debugger. 1899 local ( $package, $filename, $line ) = caller; 1900 local $filename_ini = $filename; 1901 1902 # set up the context for DB::eval, so it can properly execute 1903 # code on behalf of the user. We add the package in so that the 1904 # code is eval'ed in the proper package (not in the debugger!). 1905 local $usercontext = 1906 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;"; 1907 1908 # Create an alias to the active file magical array to simplify 1909 # the code here. 1910 local (*dbline) = $main::{ '_<' . $filename }; 1911 1912 # we need to check for pseudofiles on Mac OS (these are files 1913 # not attached to a filename, but instead stored in Dev:Pseudo) 1914 if ( $^O eq 'MacOS' && $#dbline < 0 ) { 1915 $filename_ini = $filename = 'Dev:Pseudo'; 1916 *dbline = $main::{ '_<' . $filename }; 1917 } 1918 1919 # Last line in the program. 1920 local $max = $#dbline; 1921 1922 # if we have something here, see if we should break. 1923 if ( $dbline{$line} 1924 && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) ) 1925 { 1926 1927 # Stop if the stop criterion says to just stop. 1928 if ( $stop eq '1' ) { 1929 $signal |= 1; 1930 } 1931 1932 # It's a conditional stop; eval it in the user's context and 1933 # see if we should stop. If so, remove the one-time sigil. 1934 elsif ($stop) { 1935 $evalarg = "\$DB::signal |= 1 if do {$stop}"; 1936 &eval; 1937 $dbline{$line} =~ s/;9($|\0)/$1/; 1938 } 1939 } ## end if ($dbline{$line} && ... 1940 1941 # Preserve the current stop-or-not, and see if any of the W 1942 # (watch expressions) has changed. 1943 my $was_signal = $signal; 1944 1945 # If we have any watch expressions ... 1946 if ( $trace & 2 ) { 1947 for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) { 1948 $evalarg = $to_watch[$n]; 1949 local $onetimeDump; # Tell DB::eval() to not output results 1950 1951 # Fix context DB::eval() wants to return an array, but 1952 # we need a scalar here. 1953 my ($val) = join( "', '", &eval ); 1954 $val = ( ( defined $val ) ? "'$val'" : 'undef' ); 1955 1956 # Did it change? 1957 if ( $val ne $old_watch[$n] ) { 1958 1959 # Yep! Show the difference, and fake an interrupt. 1960 $signal = 1; 1961 print $OUT <<EOP; 1962 Watchpoint $n:\t$to_watch[$n] changed: 1963 old value:\t$old_watch[$n] 1964 new value:\t$val 1965 EOP 1966 $old_watch[$n] = $val; 1967 } ## end if ($val ne $old_watch... 1968 } ## end for (my $n = 0 ; $n <= ... 1969 } ## end if ($trace & 2) 1970 1971 =head2 C<watchfunction()> 1972 1973 C<watchfunction()> is a function that can be defined by the user; it is a 1974 function which will be run on each entry to C<DB::DB>; it gets the 1975 current package, filename, and line as its parameters. 1976 1977 The watchfunction can do anything it likes; it is executing in the 1978 debugger's context, so it has access to all of the debugger's internal 1979 data structures and functions. 1980 1981 C<watchfunction()> can control the debugger's actions. Any of the following 1982 will cause the debugger to return control to the user's program after 1983 C<watchfunction()> executes: 1984 1985 =over 4 1986 1987 =item * 1988 1989 Returning a false value from the C<watchfunction()> itself. 1990 1991 =item * 1992 1993 Altering C<$single> to a false value. 1994 1995 =item * 1996 1997 Altering C<$signal> to a false value. 1998 1999 =item * 2000 2001 Turning off the C<4> bit in C<$trace> (this also disables the 2002 check for C<watchfunction()>. This can be done with 2003 2004 $trace &= ~4; 2005 2006 =back 2007 2008 =cut 2009 2010 # If there's a user-defined DB::watchfunction, call it with the 2011 # current package, filename, and line. The function executes in 2012 # the DB:: package. 2013 if ( $trace & 4 ) { # User-installed watch 2014 return 2015 if watchfunction( $package, $filename, $line ) 2016 and not $single 2017 and not $was_signal 2018 and not( $trace & ~4 ); 2019 } ## end if ($trace & 4) 2020 2021 # Pick up any alteration to $signal in the watchfunction, and 2022 # turn off the signal now. 2023 $was_signal = $signal; 2024 $signal = 0; 2025 2026 =head2 GETTING READY TO EXECUTE COMMANDS 2027 2028 The debugger decides to take control if single-step mode is on, the 2029 C<t> command was entered, or the user generated a signal. If the program 2030 has fallen off the end, we set things up so that entering further commands 2031 won't cause trouble, and we say that the program is over. 2032 2033 =cut 2034 2035 # Check to see if we should grab control ($single true, 2036 # trace set appropriately, or we got a signal). 2037 if ( $single || ( $trace & 1 ) || $was_signal ) { 2038 2039 # Yes, grab control. 2040 if ($slave_editor) { 2041 2042 # Tell the editor to update its position. 2043 $position = "\032\032$filename:$line:0\n"; 2044 print_lineinfo($position); 2045 } 2046 2047 =pod 2048 2049 Special check: if we're in package C<DB::fake>, we've gone through the 2050 C<END> block at least once. We set up everything so that we can continue 2051 to enter commands and have a valid context to be in. 2052 2053 =cut 2054 2055 elsif ( $package eq 'DB::fake' ) { 2056 2057 # Fallen off the end already. 2058 $term || &setterm; 2059 print_help(<<EOP); 2060 Debugged program terminated. Use B<q> to quit or B<R> to restart, 2061 use B<o> I<inhibit_exit> to avoid stopping after program termination, 2062 B<h q>, B<h R> or B<h o> to get additional info. 2063 EOP 2064 2065 # Set the DB::eval context appropriately. 2066 $package = 'main'; 2067 $usercontext = 2068 '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' 2069 . "package $package;"; # this won't let them modify, alas 2070 } ## end elsif ($package eq 'DB::fake') 2071 2072 =pod 2073 2074 If the program hasn't finished executing, we scan forward to the 2075 next executable line, print that out, build the prompt from the file and line 2076 number information, and print that. 2077 2078 =cut 2079 2080 else { 2081 2082 # Still somewhere in the midst of execution. Set up the 2083 # debugger prompt. 2084 $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to 2085 # Perl 5 ones (sorry, we don't print Klingon 2086 #module names) 2087 2088 $prefix = $sub =~ /::/ ? "" : "${'package'}::"; 2089 $prefix .= "$sub($filename:"; 2090 $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" ); 2091 2092 # Break up the prompt if it's really long. 2093 if ( length($prefix) > 30 ) { 2094 $position = "$prefix$line):\n$line:\t$dbline[$line]$after"; 2095 $prefix = ""; 2096 $infix = ":\t"; 2097 } 2098 else { 2099 $infix = "):\t"; 2100 $position = "$prefix$line$infix$dbline[$line]$after"; 2101 } 2102 2103 # Print current line info, indenting if necessary. 2104 if ($frame) { 2105 print_lineinfo( ' ' x $stack_depth, 2106 "$line:\t$dbline[$line]$after" ); 2107 } 2108 else { 2109 print_lineinfo($position); 2110 } 2111 2112 # Scan forward, stopping at either the end or the next 2113 # unbreakable line. 2114 for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i ) 2115 { #{ vi 2116 2117 # Drop out on null statements, block closers, and comments. 2118 last if $dbline[$i] =~ /^\s*[\;\}\#\n]/; 2119 2120 # Drop out if the user interrupted us. 2121 last if $signal; 2122 2123 # Append a newline if the line doesn't have one. Can happen 2124 # in eval'ed text, for instance. 2125 $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" ); 2126 2127 # Next executable line. 2128 $incr_pos = "$prefix$i$infix$dbline[$i]$after"; 2129 $position .= $incr_pos; 2130 if ($frame) { 2131 2132 # Print it indented if tracing is on. 2133 print_lineinfo( ' ' x $stack_depth, 2134 "$i:\t$dbline[$i]$after" ); 2135 } 2136 else { 2137 print_lineinfo($incr_pos); 2138 } 2139 } ## end for ($i = $line + 1 ; $i... 2140 } ## end else [ if ($slave_editor) 2141 } ## end if ($single || ($trace... 2142 2143 =pod 2144 2145 If there's an action to be executed for the line we stopped at, execute it. 2146 If there are any preprompt actions, execute those as well. 2147 2148 =cut 2149 2150 # If there's an action, do it now. 2151 $evalarg = $action, &eval if $action; 2152 2153 # Are we nested another level (e.g., did we evaluate a function 2154 # that had a breakpoint in it at the debugger prompt)? 2155 if ( $single || $was_signal ) { 2156 2157 # Yes, go down a level. 2158 local $level = $level + 1; 2159 2160 # Do any pre-prompt actions. 2161 foreach $evalarg (@$pre) { 2162 &eval; 2163 } 2164 2165 # Complain about too much recursion if we passed the limit. 2166 print $OUT $stack_depth . " levels deep in subroutine calls!\n" 2167 if $single & 4; 2168 2169 # The line we're currently on. Set $incr to -1 to stay here 2170 # until we get a command that tells us to advance. 2171 $start = $line; 2172 $incr = -1; # for backward motion. 2173 2174 # Tack preprompt debugger actions ahead of any actual input. 2175 @typeahead = ( @$pretype, @typeahead ); 2176 2177 =head2 WHERE ARE WE? 2178 2179 XXX Relocate this section? 2180 2181 The debugger normally shows the line corresponding to the current line of 2182 execution. Sometimes, though, we want to see the next line, or to move elsewhere 2183 in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables. 2184 2185 C<$incr> controls by how many lines the I<current> line should move forward 2186 after a command is executed. If set to -1, this indicates that the I<current> 2187 line shouldn't change. 2188 2189 C<$start> is the I<current> line. It is used for things like knowing where to 2190 move forwards or backwards from when doing an C<L> or C<-> command. 2191 2192 C<$max> tells the debugger where the last line of the current file is. It's 2193 used to terminate loops most often. 2194 2195 =head2 THE COMMAND LOOP 2196 2197 Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes 2198 in two parts: 2199 2200 =over 4 2201 2202 =item * 2203 2204 The outer part of the loop, starting at the C<CMD> label. This loop 2205 reads a command and then executes it. 2206 2207 =item * 2208 2209 The inner part of the loop, starting at the C<PIPE> label. This part 2210 is wholly contained inside the C<CMD> block and only executes a command. 2211 Used to handle commands running inside a pager. 2212 2213 =back 2214 2215 So why have two labels to restart the loop? Because sometimes, it's easier to 2216 have a command I<generate> another command and then re-execute the loop to do 2217 the new command. This is faster, but perhaps a bit more convoluted. 2218 2219 =cut 2220 2221 # The big command dispatch loop. It keeps running until the 2222 # user yields up control again. 2223 # 2224 # If we have a terminal for input, and we get something back 2225 # from readline(), keep on processing. 2226 CMD: 2227 while ( 2228 2229 # We have a terminal, or can get one ... 2230 ( $term || &setterm ), 2231 2232 # ... and it belogs to this PID or we get one for this PID ... 2233 ( $term_pid == $$ or resetterm(1) ), 2234 2235 # ... and we got a line of command input ... 2236 defined( 2237 $cmd = &readline( 2238 "$pidprompt $tid DB" 2239 . ( '<' x $level ) 2240 . ( $#hist + 1 ) 2241 . ( '>' x $level ) . " " 2242 ) 2243 ) 2244 ) 2245 { 2246 2247 share($cmd); 2248 # ... try to execute the input as debugger commands. 2249 2250 # Don't stop running. 2251 $single = 0; 2252 2253 # No signal is active. 2254 $signal = 0; 2255 2256 # Handle continued commands (ending with \): 2257 $cmd =~ s/\\$/\n/ && do { 2258 $cmd .= &readline(" cont: "); 2259 redo CMD; 2260 }; 2261 2262 =head4 The null command 2263 2264 A newline entered by itself means I<re-execute the last command>. We grab the 2265 command out of C<$laststep> (where it was recorded previously), and copy it 2266 back into C<$cmd> to be executed below. If there wasn't any previous command, 2267 we'll do nothing below (no command will match). If there was, we also save it 2268 in the command history and fall through to allow the command parsing to pick 2269 it up. 2270 2271 =cut 2272 2273 # Empty input means repeat the last command. 2274 $cmd =~ /^$/ && ( $cmd = $laststep ); 2275 chomp($cmd); # get rid of the annoying extra newline 2276 push( @hist, $cmd ) if length($cmd) > 1; 2277 push( @truehist, $cmd ); 2278 share(@hist); 2279 share(@truehist); 2280 2281 # This is a restart point for commands that didn't arrive 2282 # via direct user input. It allows us to 'redo PIPE' to 2283 # re-execute command processing without reading a new command. 2284 PIPE: { 2285 $cmd =~ s/^\s+//s; # trim annoying leading whitespace 2286 $cmd =~ s/\s+$//s; # trim annoying trailing whitespace 2287 ($i) = split( /\s+/, $cmd ); 2288 2289 =head3 COMMAND ALIASES 2290 2291 The debugger can create aliases for commands (these are stored in the 2292 C<%alias> hash). Before a command is executed, the command loop looks it up 2293 in the alias hash and substitutes the contents of the alias for the command, 2294 completely replacing it. 2295 2296 =cut 2297 2298 # See if there's an alias for the command, and set it up if so. 2299 if ( $alias{$i} ) { 2300 2301 # Squelch signal handling; we want to keep control here 2302 # if something goes loco during the alias eval. 2303 local $SIG{__DIE__}; 2304 local $SIG{__WARN__}; 2305 2306 # This is a command, so we eval it in the DEBUGGER's 2307 # scope! Otherwise, we can't see the special debugger 2308 # variables, or get to the debugger's subs. (Well, we 2309 # _could_, but why make it even more complicated?) 2310 eval "\$cmd =~ $alias{$i}"; 2311 if ($@) { 2312 local $\ = ''; 2313 print $OUT "Couldn't evaluate `$i' alias: $@"; 2314 next CMD; 2315 } 2316 } ## end if ($alias{$i}) 2317 2318 =head3 MAIN-LINE COMMANDS 2319 2320 All of these commands work up to and after the program being debugged has 2321 terminated. 2322 2323 =head4 C<q> - quit 2324 2325 Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't 2326 try to execute further, cleaning any restart-related stuff out of the 2327 environment, and executing with the last value of C<$?>. 2328 2329 =cut 2330 2331 $cmd =~ /^q$/ && do { 2332 $fall_off_end = 1; 2333 clean_ENV(); 2334 exit $?; 2335 }; 2336 2337 =head4 C<t> - trace 2338 2339 Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.). 2340 2341 =cut 2342 2343 $cmd =~ /^t$/ && do { 2344 $trace ^= 1; 2345 local $\ = ''; 2346 print $OUT "Trace = " 2347 . ( ( $trace & 1 ) ? "on" : "off" ) . "\n"; 2348 next CMD; 2349 }; 2350 2351 =head4 C<S> - list subroutines matching/not matching a pattern 2352 2353 Walks through C<%sub>, checking to see whether or not to print the name. 2354 2355 =cut 2356 2357 $cmd =~ /^S(\s+(!)?(.+))?$/ && do { 2358 2359 $Srev = defined $2; # Reverse scan? 2360 $Spatt = $3; # The pattern (if any) to use. 2361 $Snocheck = !defined $1; # No args - print all subs. 2362 2363 # Need to make these sane here. 2364 local $\ = ''; 2365 local $, = ''; 2366 2367 # Search through the debugger's magical hash of subs. 2368 # If $nocheck is true, just print the sub name. 2369 # Otherwise, check it against the pattern. We then use 2370 # the XOR trick to reverse the condition as required. 2371 foreach $subname ( sort( keys %sub ) ) { 2372 if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) { 2373 print $OUT $subname, "\n"; 2374 } 2375 } 2376 next CMD; 2377 }; 2378 2379 =head4 C<X> - list variables in current package 2380 2381 Since the C<V> command actually processes this, just change this to the 2382 appropriate C<V> command and fall through. 2383 2384 =cut 2385 2386 $cmd =~ s/^X\b/V $package/; 2387 2388 =head4 C<V> - list variables 2389 2390 Uses C<dumpvar.pl> to dump out the current values for selected variables. 2391 2392 =cut 2393 2394 # Bare V commands get the currently-being-debugged package 2395 # added. 2396 $cmd =~ /^V$/ && do { 2397 $cmd = "V $package"; 2398 }; 2399 2400 # V - show variables in package. 2401 $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do { 2402 2403 # Save the currently selected filehandle and 2404 # force output to debugger's filehandle (dumpvar 2405 # just does "print" for output). 2406 local ($savout) = select($OUT); 2407 2408 # Grab package name and variables to dump. 2409 $packname = $1; 2410 @vars = split( ' ', $2 ); 2411 2412 # If main::dumpvar isn't here, get it. 2413 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; 2414 if ( defined &main::dumpvar ) { 2415 2416 # We got it. Turn off subroutine entry/exit messages 2417 # for the moment, along with return values. 2418 local $frame = 0; 2419 local $doret = -2; 2420 2421 # must detect sigpipe failures - not catching 2422 # then will cause the debugger to die. 2423 eval { 2424 &main::dumpvar( 2425 $packname, 2426 defined $option{dumpDepth} 2427 ? $option{dumpDepth} 2428 : -1, # assume -1 unless specified 2429 @vars 2430 ); 2431 }; 2432 2433 # The die doesn't need to include the $@, because 2434 # it will automatically get propagated for us. 2435 if ($@) { 2436 die unless $@ =~ /dumpvar print failed/; 2437 } 2438 } ## end if (defined &main::dumpvar) 2439 else { 2440 2441 # Couldn't load dumpvar. 2442 print $OUT "dumpvar.pl not available.\n"; 2443 } 2444 2445 # Restore the output filehandle, and go round again. 2446 select($savout); 2447 next CMD; 2448 }; 2449 2450 =head4 C<x> - evaluate and print an expression 2451 2452 Hands the expression off to C<DB::eval>, setting it up to print the value 2453 via C<dumpvar.pl> instead of just printing it directly. 2454 2455 =cut 2456 2457 $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval() 2458 $onetimeDump = 'dump'; # main::dumpvar shows the output 2459 2460 # handle special "x 3 blah" syntax XXX propagate 2461 # doc back to special variables. 2462 if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) { 2463 $onetimedumpDepth = $1; 2464 } 2465 }; 2466 2467 =head4 C<m> - print methods 2468 2469 Just uses C<DB::methods> to determine what methods are available. 2470 2471 =cut 2472 2473 $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do { 2474 methods($1); 2475 next CMD; 2476 }; 2477 2478 # m expr - set up DB::eval to do the work 2479 $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval() 2480 $onetimeDump = 'methods'; # method output gets used there 2481 }; 2482 2483 =head4 C<f> - switch files 2484 2485 =cut 2486 2487 $cmd =~ /^f\b\s*(.*)/ && do { 2488 $file = $1; 2489 $file =~ s/\s+$//; 2490 2491 # help for no arguments (old-style was return from sub). 2492 if ( !$file ) { 2493 print $OUT 2494 "The old f command is now the r command.\n"; # hint 2495 print $OUT "The new f command switches filenames.\n"; 2496 next CMD; 2497 } ## end if (!$file) 2498 2499 # if not in magic file list, try a close match. 2500 if ( !defined $main::{ '_<' . $file } ) { 2501 if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) { 2502 { 2503 $try = substr( $try, 2 ); 2504 print $OUT "Choosing $try matching `$file':\n"; 2505 $file = $try; 2506 } 2507 } ## end if (($try) = grep(m#^_<.*$file#... 2508 } ## end if (!defined $main::{ ... 2509 2510 # If not successfully switched now, we failed. 2511 if ( !defined $main::{ '_<' . $file } ) { 2512 print $OUT "No file matching `$file' is loaded.\n"; 2513 next CMD; 2514 } 2515 2516 # We switched, so switch the debugger internals around. 2517 elsif ( $file ne $filename ) { 2518 *dbline = $main::{ '_<' . $file }; 2519 $max = $#dbline; 2520 $filename = $file; 2521 $start = 1; 2522 $cmd = "l"; 2523 } ## end elsif ($file ne $filename) 2524 2525 # We didn't switch; say we didn't. 2526 else { 2527 print $OUT "Already in $file.\n"; 2528 next CMD; 2529 } 2530 }; 2531 2532 =head4 C<.> - return to last-executed line. 2533 2534 We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead, 2535 and then we look up the line in the magical C<%dbline> hash. 2536 2537 =cut 2538 2539 # . command. 2540 $cmd =~ /^\.$/ && do { 2541 $incr = -1; # stay at current line 2542 2543 # Reset everything to the old location. 2544 $start = $line; 2545 $filename = $filename_ini; 2546 *dbline = $main::{ '_<' . $filename }; 2547 $max = $#dbline; 2548 2549 # Now where are we? 2550 print_lineinfo($position); 2551 next CMD; 2552 }; 2553 2554 =head4 C<-> - back one window 2555 2556 We change C<$start> to be one window back; if we go back past the first line, 2557 we set it to be the first line. We ser C<$incr> to put us back at the 2558 currently-executing line, and then put a C<l $start +> (list one window from 2559 C<$start>) in C<$cmd> to be executed later. 2560 2561 =cut 2562 2563 # - - back a window. 2564 $cmd =~ /^-$/ && do { 2565 2566 # back up by a window; go to 1 if back too far. 2567 $start -= $incr + $window + 1; 2568 $start = 1 if $start <= 0; 2569 $incr = $window - 1; 2570 2571 # Generate and execute a "l +" command (handled below). 2572 $cmd = 'l ' . ($start) . '+'; 2573 }; 2574 2575 =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>, {, {{> 2576 2577 In Perl 5.8.0, a realignment of the commands was done to fix up a number of 2578 problems, most notably that the default case of several commands destroying 2579 the user's work in setting watchpoints, actions, etc. We wanted, however, to 2580 retain the old commands for those who were used to using them or who preferred 2581 them. At this point, we check for the new commands and call C<cmd_wrapper> to 2582 deal with them instead of processing them in-line. 2583 2584 =cut 2585 2586 # All of these commands were remapped in perl 5.8.0; 2587 # we send them off to the secondary dispatcher (see below). 2588 $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do { 2589 &cmd_wrapper( $1, $2, $line ); 2590 next CMD; 2591 }; 2592 2593 =head4 C<y> - List lexicals in higher scope 2594 2595 Uses C<PadWalker> to find the lexicals supplied as arguments in a scope 2596 above the current one and then displays then using C<dumpvar.pl>. 2597 2598 =cut 2599 2600 $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do { 2601 2602 # See if we've got the necessary support. 2603 eval { require PadWalker; PadWalker->VERSION(0.08) } 2604 or &warn( 2605 $@ =~ /locate/ 2606 ? "PadWalker module not found - please install\n" 2607 : $@ 2608 ) 2609 and next CMD; 2610 2611 # Load up dumpvar if we don't have it. If we can, that is. 2612 do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; 2613 defined &main::dumpvar 2614 or print $OUT "dumpvar.pl not available.\n" 2615 and next CMD; 2616 2617 # Got all the modules we need. Find them and print them. 2618 my @vars = split( ' ', $2 || '' ); 2619 2620 # Find the pad. 2621 my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) }; 2622 2623 # Oops. Can't find it. 2624 $@ and $@ =~ s/ at .*//, &warn($@), next CMD; 2625 2626 # Show the desired vars with dumplex(). 2627 my $savout = select($OUT); 2628 2629 # Have dumplex dump the lexicals. 2630 dumpvar::dumplex( $_, $h->{$_}, 2631 defined $option{dumpDepth} ? $option{dumpDepth} : -1, 2632 @vars ) 2633 for sort keys %$h; 2634 select($savout); 2635 next CMD; 2636 }; 2637 2638 =head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS 2639 2640 All of the commands below this point don't work after the program being 2641 debugged has ended. All of them check to see if the program has ended; this 2642 allows the commands to be relocated without worrying about a 'line of 2643 demarcation' above which commands can be entered anytime, and below which 2644 they can't. 2645 2646 =head4 C<n> - single step, but don't trace down into subs 2647 2648 Done by setting C<$single> to 2, which forces subs to execute straight through 2649 when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>, 2650 so a null command knows what to re-execute. 2651 2652 =cut 2653 2654 # n - next 2655 $cmd =~ /^n$/ && do { 2656 end_report(), next CMD if $finished and $level <= 1; 2657 2658 # Single step, but don't enter subs. 2659 $single = 2; 2660 2661 # Save for empty command (repeat last). 2662 $laststep = $cmd; 2663 last CMD; 2664 }; 2665 2666 =head4 C<s> - single-step, entering subs 2667 2668 Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside 2669 subs. Also saves C<s> as C<$lastcmd>. 2670 2671 =cut 2672 2673 # s - single step. 2674 $cmd =~ /^s$/ && do { 2675 2676 # Get out and restart the command loop if program 2677 # has finished. 2678 end_report(), next CMD if $finished and $level <= 1; 2679 2680 # Single step should enter subs. 2681 $single = 1; 2682 2683 # Save for empty command (repeat last). 2684 $laststep = $cmd; 2685 last CMD; 2686 }; 2687 2688 =head4 C<c> - run continuously, setting an optional breakpoint 2689 2690 Most of the code for this command is taken up with locating the optional 2691 breakpoint, which is either a subroutine name or a line number. We set 2692 the appropriate one-time-break in C<@dbline> and then turn off single-stepping 2693 in this and all call levels above this one. 2694 2695 =cut 2696 2697 # c - start continuous execution. 2698 $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do { 2699 2700 # Hey, show's over. The debugged program finished 2701 # executing already. 2702 end_report(), next CMD if $finished and $level <= 1; 2703 2704 # Capture the place to put a one-time break. 2705 $subname = $i = $1; 2706 2707 # Probably not needed, since we finish an interactive 2708 # sub-session anyway... 2709 # local $filename = $filename; 2710 # local *dbline = *dbline; # XXX Would this work?! 2711 # 2712 # The above question wonders if localizing the alias 2713 # to the magic array works or not. Since it's commented 2714 # out, we'll just leave that to speculation for now. 2715 2716 # If the "subname" isn't all digits, we'll assume it 2717 # is a subroutine name, and try to find it. 2718 if ( $subname =~ /\D/ ) { # subroutine name 2719 # Qualify it to the current package unless it's 2720 # already qualified. 2721 $subname = $package . "::" . $subname 2722 unless $subname =~ /::/; 2723 2724 # find_sub will return "file:line_number" corresponding 2725 # to where the subroutine is defined; we call find_sub, 2726 # break up the return value, and assign it in one 2727 # operation. 2728 ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ ); 2729 2730 # Force the line number to be numeric. 2731 $i += 0; 2732 2733 # If we got a line number, we found the sub. 2734 if ($i) { 2735 2736 # Switch all the debugger's internals around so 2737 # we're actually working with that file. 2738 $filename = $file; 2739 *dbline = $main::{ '_<' . $filename }; 2740 2741 # Mark that there's a breakpoint in this file. 2742 $had_breakpoints{$filename} |= 1; 2743 2744 # Scan forward to the first executable line 2745 # after the 'sub whatever' line. 2746 $max = $#dbline; 2747 ++$i while $dbline[$i] == 0 && $i < $max; 2748 } ## end if ($i) 2749 2750 # We didn't find a sub by that name. 2751 else { 2752 print $OUT "Subroutine $subname not found.\n"; 2753 next CMD; 2754 } 2755 } ## end if ($subname =~ /\D/) 2756 2757 # At this point, either the subname was all digits (an 2758 # absolute line-break request) or we've scanned through 2759 # the code following the definition of the sub, looking 2760 # for an executable, which we may or may not have found. 2761 # 2762 # If $i (which we set $subname from) is non-zero, we 2763 # got a request to break at some line somewhere. On 2764 # one hand, if there wasn't any real subroutine name 2765 # involved, this will be a request to break in the current 2766 # file at the specified line, so we have to check to make 2767 # sure that the line specified really is breakable. 2768 # 2769 # On the other hand, if there was a subname supplied, the 2770 # preceding block has moved us to the proper file and 2771 # location within that file, and then scanned forward 2772 # looking for the next executable line. We have to make 2773 # sure that one was found. 2774 # 2775 # On the gripping hand, we can't do anything unless the 2776 # current value of $i points to a valid breakable line. 2777 # Check that. 2778 if ($i) { 2779 2780 # Breakable? 2781 if ( $dbline[$i] == 0 ) { 2782 print $OUT "Line $i not breakable.\n"; 2783 next CMD; 2784 } 2785 2786 # Yes. Set up the one-time-break sigil. 2787 $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p. 2788 } ## end if ($i) 2789 2790 # Turn off stack tracing from here up. 2791 for ( $i = 0 ; $i <= $stack_depth ; ) { 2792 $stack[ $i++ ] &= ~1; 2793 } 2794 last CMD; 2795 }; 2796 2797 =head4 C<r> - return from a subroutine 2798 2799 For C<r> to work properly, the debugger has to stop execution again 2800 immediately after the return is executed. This is done by forcing 2801 single-stepping to be on in the call level above the current one. If 2802 we are printing return values when a C<r> is executed, set C<$doret> 2803 appropriately, and force us out of the command loop. 2804 2805 =cut 2806 2807 # r - return from the current subroutine. 2808 $cmd =~ /^r$/ && do { 2809 2810 # Can't do anythign if the program's over. 2811 end_report(), next CMD if $finished and $level <= 1; 2812 2813 # Turn on stack trace. 2814 $stack[$stack_depth] |= 1; 2815 2816 # Print return value unless the stack is empty. 2817 $doret = $option{PrintRet} ? $stack_depth - 1 : -2; 2818 last CMD; 2819 }; 2820 2821 =head4 C<T> - stack trace 2822 2823 Just calls C<DB::print_trace>. 2824 2825 =cut 2826 2827 $cmd =~ /^T$/ && do { 2828 print_trace( $OUT, 1 ); # skip DB 2829 next CMD; 2830 }; 2831 2832 =head4 C<w> - List window around current line. 2833 2834 Just calls C<DB::cmd_w>. 2835 2836 =cut 2837 2838 $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; }; 2839 2840 =head4 C<W> - watch-expression processing. 2841 2842 Just calls C<DB::cmd_W>. 2843 2844 =cut 2845 2846 $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; }; 2847 2848 =head4 C</> - search forward for a string in the source 2849 2850 We take the argument and treat it as a pattern. If it turns out to be a 2851 bad one, we return the error we got from trying to C<eval> it and exit. 2852 If not, we create some code to do the search and C<eval> it so it can't 2853 mess us up. 2854 2855 =cut 2856 2857 $cmd =~ /^\/(.*)$/ && do { 2858 2859 # The pattern as a string. 2860 $inpat = $1; 2861 2862 # Remove the final slash. 2863 $inpat =~ s:([^\\])/$:$1:; 2864 2865 # If the pattern isn't null ... 2866 if ( $inpat ne "" ) { 2867 2868 # Turn of warn and die procesing for a bit. 2869 local $SIG{__DIE__}; 2870 local $SIG{__WARN__}; 2871 2872 # Create the pattern. 2873 eval '$inpat =~ m' . "\a$inpat\a"; 2874 if ( $@ ne "" ) { 2875 2876 # Oops. Bad pattern. No biscuit. 2877 # Print the eval error and go back for more 2878 # commands. 2879 print $OUT "$@"; 2880 next CMD; 2881 } 2882 $pat = $inpat; 2883 } ## end if ($inpat ne "") 2884 2885 # Set up to stop on wrap-around. 2886 $end = $start; 2887 2888 # Don't move off the current line. 2889 $incr = -1; 2890 2891 # Done in eval so nothing breaks if the pattern 2892 # does something weird. 2893 eval ' 2894 for (;;) { 2895 # Move ahead one line. 2896 ++$start; 2897 2898 # Wrap if we pass the last line. 2899 $start = 1 if ($start > $max); 2900 2901 # Stop if we have gotten back to this line again, 2902 last if ($start == $end); 2903 2904 # A hit! (Note, though, that we are doing 2905 # case-insensitive matching. Maybe a qr// 2906 # expression would be better, so the user could 2907 # do case-sensitive matching if desired. 2908 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) { 2909 if ($slave_editor) { 2910 # Handle proper escaping in the slave. 2911 print $OUT "\032\032$filename:$start:0\n"; 2912 } 2913 else { 2914 # Just print the line normally. 2915 print $OUT "$start:\t",$dbline[$start],"\n"; 2916 } 2917 # And quit since we found something. 2918 last; 2919 } 2920 } '; 2921 2922 # If we wrapped, there never was a match. 2923 print $OUT "/$pat/: not found\n" if ( $start == $end ); 2924 next CMD; 2925 }; 2926 2927 =head4 C<?> - search backward for a string in the source 2928 2929 Same as for C</>, except the loop runs backwards. 2930 2931 =cut 2932 2933 # ? - backward pattern search. 2934 $cmd =~ /^\?(.*)$/ && do { 2935 2936 # Get the pattern, remove trailing question mark. 2937 $inpat = $1; 2938 $inpat =~ s:([^\\])\?$:$1:; 2939 2940 # If we've got one ... 2941 if ( $inpat ne "" ) { 2942 2943 # Turn off die & warn handlers. 2944 local $SIG{__DIE__}; 2945 local $SIG{__WARN__}; 2946 eval '$inpat =~ m' . "\a$inpat\a"; 2947 2948 if ( $@ ne "" ) { 2949 2950 # Ouch. Not good. Print the error. 2951 print $OUT $@; 2952 next CMD; 2953 } 2954 $pat = $inpat; 2955 } ## end if ($inpat ne "") 2956 2957 # Where we are now is where to stop after wraparound. 2958 $end = $start; 2959 2960 # Don't move away from this line. 2961 $incr = -1; 2962 2963 # Search inside the eval to prevent pattern badness 2964 # from killing us. 2965 eval ' 2966 for (;;) { 2967 # Back up a line. 2968 --$start; 2969 2970 # Wrap if we pass the first line. 2971 2972 $start = $max if ($start <= 0); 2973 2974 # Quit if we get back where we started, 2975 last if ($start == $end); 2976 2977 # Match? 2978 if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) { 2979 if ($slave_editor) { 2980 # Yep, follow slave editor requirements. 2981 print $OUT "\032\032$filename:$start:0\n"; 2982 } 2983 else { 2984 # Yep, just print normally. 2985 print $OUT "$start:\t",$dbline[$start],"\n"; 2986 } 2987 2988 # Found, so done. 2989 last; 2990 } 2991 } '; 2992 2993 # Say we failed if the loop never found anything, 2994 print $OUT "?$pat?: not found\n" if ( $start == $end ); 2995 next CMD; 2996 }; 2997 2998 =head4 C<$rc> - Recall command 2999 3000 Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports 3001 that the terminal supports history). It find the the command required, puts it 3002 into C<$cmd>, and redoes the loop to execute it. 3003 3004 =cut 3005 3006 # $rc - recall command. 3007 $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do { 3008 3009 # No arguments, take one thing off history. 3010 pop(@hist) if length($cmd) > 1; 3011 3012 # Relative (- found)? 3013 # Y - index back from most recent (by 1 if bare minus) 3014 # N - go to that particular command slot or the last 3015 # thing if nothing following. 3016 $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist ); 3017 3018 # Pick out the command desired. 3019 $cmd = $hist[$i]; 3020 3021 # Print the command to be executed and restart the loop 3022 # with that command in the buffer. 3023 print $OUT $cmd, "\n"; 3024 redo CMD; 3025 }; 3026 3027 =head4 C<$sh$sh> - C<system()> command 3028 3029 Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and 3030 C<STDOUT> from getting messed up. 3031 3032 =cut 3033 3034 # $sh$sh - run a shell command (if it's all ASCII). 3035 # Can't run shell commands with Unicode in the debugger, hmm. 3036 $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do { 3037 3038 # System it. 3039 &system($1); 3040 next CMD; 3041 }; 3042 3043 =head4 C<$rc I<pattern> $rc> - Search command history 3044 3045 Another command to manipulate C<@hist>: this one searches it with a pattern. 3046 If a command is found, it is placed in C<$cmd> and executed via C<redo>. 3047 3048 =cut 3049 3050 # $rc pattern $rc - find a command in the history. 3051 $cmd =~ /^$rc([^$rc].*)$/ && do { 3052 3053 # Create the pattern to use. 3054 $pat = "^$1"; 3055 3056 # Toss off last entry if length is >1 (and it always is). 3057 pop(@hist) if length($cmd) > 1; 3058 3059 # Look backward through the history. 3060 for ( $i = $#hist ; $i ; --$i ) { 3061 3062 # Stop if we find it. 3063 last if $hist[$i] =~ /$pat/; 3064 } 3065 3066 if ( !$i ) { 3067 3068 # Never found it. 3069 print $OUT "No such command!\n\n"; 3070 next CMD; 3071 } 3072 3073 # Found it. Put it in the buffer, print it, and process it. 3074 $cmd = $hist[$i]; 3075 print $OUT $cmd, "\n"; 3076 redo CMD; 3077 }; 3078 3079 =head4 C<$sh> - Invoke a shell 3080 3081 Uses C<DB::system> to invoke a shell. 3082 3083 =cut 3084 3085 # $sh - start a shell. 3086 $cmd =~ /^$sh$/ && do { 3087 3088 # Run the user's shell. If none defined, run Bourne. 3089 # We resume execution when the shell terminates. 3090 &system( $ENV{SHELL} || "/bin/sh" ); 3091 next CMD; 3092 }; 3093 3094 =head4 C<$sh I<command>> - Force execution of a command in a shell 3095 3096 Like the above, but the command is passed to the shell. Again, we use 3097 C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>. 3098 3099 =cut 3100 3101 # $sh command - start a shell and run a command in it. 3102 $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do { 3103 3104 # XXX: using csh or tcsh destroys sigint retvals! 3105 #&system($1); # use this instead 3106 3107 # use the user's shell, or Bourne if none defined. 3108 &system( $ENV{SHELL} || "/bin/sh", "-c", $1 ); 3109 next CMD; 3110 }; 3111 3112 =head4 C<H> - display commands in history 3113 3114 Prints the contents of C<@hist> (if any). 3115 3116 =cut 3117 3118 $cmd =~ /^H\b\s*\*/ && do { 3119 @hist = @truehist = (); 3120 print $OUT "History cleansed\n"; 3121 next CMD; 3122 }; 3123 3124 $cmd =~ /^H\b\s*(-(\d+))?/ && do { 3125 3126 # Anything other than negative numbers is ignored by 3127 # the (incorrect) pattern, so this test does nothing. 3128 $end = $2 ? ( $#hist - $2 ) : 0; 3129 3130 # Set to the minimum if less than zero. 3131 $hist = 0 if $hist < 0; 3132 3133 # Start at the end of the array. 3134 # Stay in while we're still above the ending value. 3135 # Tick back by one each time around the loop. 3136 for ( $i = $#hist ; $i > $end ; $i-- ) { 3137 3138 # Print the command unless it has no arguments. 3139 print $OUT "$i: ", $hist[$i], "\n" 3140 unless $hist[$i] =~ /^.?$/; 3141 } 3142 next CMD; 3143 }; 3144 3145 =head4 C<man, doc, perldoc> - look up documentation 3146 3147 Just calls C<runman()> to print the appropriate document. 3148 3149 =cut 3150 3151 # man, perldoc, doc - show manual pages. 3152 $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do { 3153 runman($1); 3154 next CMD; 3155 }; 3156 3157 =head4 C<p> - print 3158 3159 Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at 3160 the bottom of the loop. 3161 3162 =cut 3163 3164 # p - print (no args): print $_. 3165 $cmd =~ s/^p$/print {\$DB::OUT} \$_/; 3166 3167 # p - print the given expression. 3168 $cmd =~ s/^p\b/print {\$DB::OUT} /; 3169 3170 =head4 C<=> - define command alias 3171 3172 Manipulates C<%alias> to add or list command aliases. 3173 3174 =cut 3175 3176 # = - set up a command alias. 3177 $cmd =~ s/^=\s*// && do { 3178 my @keys; 3179 if ( length $cmd == 0 ) { 3180 3181 # No args, get current aliases. 3182 @keys = sort keys %alias; 3183 } 3184 elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) { 3185 3186 # Creating a new alias. $k is alias name, $v is 3187 # alias value. 3188 3189 # can't use $_ or kill //g state 3190 for my $x ( $k, $v ) { 3191 3192 # Escape "alarm" characters. 3193 $x =~ s/\a/\\a/g; 3194 } 3195 3196 # Substitute key for value, using alarm chars 3197 # as separators (which is why we escaped them in 3198 # the command). 3199 $alias{$k} = "s\a$k\a$v\a"; 3200 3201 # Turn off standard warn and die behavior. 3202 local $SIG{__DIE__}; 3203 local $SIG{__WARN__}; 3204 3205 # Is it valid Perl? 3206 unless ( eval "sub { s\a$k\a$v\a }; 1" ) { 3207 3208 # Nope. Bad alias. Say so and get out. 3209 print $OUT "Can't alias $k to $v: $@\n"; 3210 delete $alias{$k}; 3211 next CMD; 3212 } 3213 3214 # We'll only list the new one. 3215 @keys = ($k); 3216 } ## end elsif (my ($k, $v) = ($cmd... 3217 3218 # The argument is the alias to list. 3219 else { 3220 @keys = ($cmd); 3221 } 3222 3223 # List aliases. 3224 for my $k (@keys) { 3225 3226 # Messy metaquoting: Trim the substiution code off. 3227 # We use control-G as the delimiter because it's not 3228 # likely to appear in the alias. 3229 if ( ( my $v = $alias{$k} ) =~ ss\a$k\a(.*)\a$1 ) { 3230 3231 # Print the alias. 3232 print $OUT "$k\t= $1\n"; 3233 } 3234 elsif ( defined $alias{$k} ) { 3235 3236 # Couldn't trim it off; just print the alias code. 3237 print $OUT "$k\t$alias{$k}\n"; 3238 } 3239 else { 3240 3241 # No such, dude. 3242 print "No alias for $k\n"; 3243 } 3244 } ## end for my $k (@keys) 3245 next CMD; 3246 }; 3247 3248 =head4 C<source> - read commands from a file. 3249 3250 Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will 3251 pick it up. 3252 3253 =cut 3254 3255 # source - read commands from a file (or pipe!) and execute. 3256 $cmd =~ /^source\s+(.*\S)/ && do { 3257 if ( open my $fh, $1 ) { 3258 3259 # Opened OK; stick it in the list of file handles. 3260 push @cmdfhs, $fh; 3261 } 3262 else { 3263 3264 # Couldn't open it. 3265 &warn("Can't execute `$1': $!\n"); 3266 } 3267 next CMD; 3268 }; 3269 3270 =head4 C<save> - send current history to a file 3271 3272 Takes the complete history, (not the shrunken version you see with C<H>), 3273 and saves it to the given filename, so it can be replayed using C<source>. 3274 3275 Note that all C<^(save|source)>'s are commented out with a view to minimise recursion. 3276 3277 =cut 3278 3279 # save source - write commands to a file for later use 3280 $cmd =~ /^save\s*(.*)$/ && do { 3281 my $file = $1 || '.perl5dbrc'; # default? 3282 if ( open my $fh, "> $file" ) { 3283 3284 # chomp to remove extraneous newlines from source'd files 3285 chomp( my @truelist = 3286 map { m/^\s*(save|source)/ ? "#$_" : $_ } 3287 @truehist ); 3288 print $fh join( "\n", @truelist ); 3289 print "commands saved in $file\n"; 3290 } 3291 else { 3292 &warn("Can't save debugger commands in '$1': $!\n"); 3293 } 3294 next CMD; 3295 }; 3296 3297 =head4 C<R> - restart 3298 3299 Restart the debugger session. 3300 3301 =head4 C<rerun> - rerun the current session 3302 3303 Return to any given position in the B<true>-history list 3304 3305 =cut 3306 3307 # R - restart execution. 3308 # rerun - controlled restart execution. 3309 $cmd =~ /^(R|rerun\s*(.*))$/ && do { 3310 my @args = ($1 eq 'R' ? restart() : rerun($2)); 3311 3312 # Close all non-system fds for a clean restart. A more 3313 # correct method would be to close all fds that were not 3314 # open when the process started, but this seems to be 3315 # hard. See "debugger 'R'estart and open database 3316 # connections" on p5p. 3317 3318 my $max_fd = 1024; # default if POSIX can't be loaded 3319 if (eval { require POSIX }) { 3320 $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()); 3321 } 3322 3323 if (defined $max_fd) { 3324 foreach ($^F+1 .. $max_fd-1) { 3325 next unless open FD_TO_CLOSE, "<&=$_"; 3326 close(FD_TO_CLOSE); 3327 } 3328 } 3329 3330 # And run Perl again. We use exec() to keep the 3331 # PID stable (and that way $ini_pids is still valid). 3332 exec(@args) || print $OUT "exec failed: $!\n"; 3333 3334 last CMD; 3335 }; 3336 3337 =head4 C<|, ||> - pipe output through the pager. 3338 3339 For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT> 3340 (the program's standard output). For C<||>, we only save C<OUT>. We open a 3341 pipe to the pager (restoring the output filehandles if this fails). If this 3342 is the C<|> command, we also set up a C<SIGPIPE> handler which will simply 3343 set C<$signal>, sending us back into the debugger. 3344 3345 We then trim off the pipe symbols and C<redo> the command loop at the 3346 C<PIPE> label, causing us to evaluate the command in C<$cmd> without 3347 reading another. 3348 3349 =cut 3350 3351 # || - run command in the pager, with output to DB::OUT. 3352 $cmd =~ /^\|\|?\s*[^|]/ && do { 3353 if ( $pager =~ /^\|/ ) { 3354 3355 # Default pager is into a pipe. Redirect I/O. 3356 open( SAVEOUT, ">&STDOUT" ) 3357 || &warn("Can't save STDOUT"); 3358 open( STDOUT, ">&OUT" ) 3359 || &warn("Can't redirect STDOUT"); 3360 } ## end if ($pager =~ /^\|/) 3361 else { 3362 3363 # Not into a pipe. STDOUT is safe. 3364 open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT"); 3365 } 3366 3367 # Fix up environment to record we have less if so. 3368 fix_less(); 3369 3370 unless ( $piped = open( OUT, $pager ) ) { 3371 3372 # Couldn't open pipe to pager. 3373 &warn("Can't pipe output to `$pager'"); 3374 if ( $pager =~ /^\|/ ) { 3375 3376 # Redirect I/O back again. 3377 open( OUT, ">&STDOUT" ) # XXX: lost message 3378 || &warn("Can't restore DB::OUT"); 3379 open( STDOUT, ">&SAVEOUT" ) 3380 || &warn("Can't restore STDOUT"); 3381 close(SAVEOUT); 3382 } ## end if ($pager =~ /^\|/) 3383 else { 3384 3385 # Redirect I/O. STDOUT already safe. 3386 open( OUT, ">&STDOUT" ) # XXX: lost message 3387 || &warn("Can't restore DB::OUT"); 3388 } 3389 next CMD; 3390 } ## end unless ($piped = open(OUT,... 3391 3392 # Set up broken-pipe handler if necessary. 3393 $SIG{PIPE} = \&DB::catch 3394 if $pager =~ /^\|/ 3395 && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} ); 3396 3397 # Save current filehandle, unbuffer out, and put it back. 3398 $selected = select(OUT); 3399 $| = 1; 3400 3401 # Don't put it back if pager was a pipe. 3402 select($selected), $selected = "" unless $cmd =~ /^\|\|/; 3403 3404 # Trim off the pipe symbols and run the command now. 3405 $cmd =~ s/^\|+\s*//; 3406 redo PIPE; 3407 }; 3408 3409 =head3 END OF COMMAND PARSING 3410 3411 Anything left in C<$cmd> at this point is a Perl expression that we want to 3412 evaluate. We'll always evaluate in the user's context, and fully qualify 3413 any variables we might want to address in the C<DB> package. 3414 3415 =cut 3416 3417 # t - turn trace on. 3418 $cmd =~ s/^t\s/\$DB::trace |= 1;\n/; 3419 3420 # s - single-step. Remember the last command was 's'. 3421 $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' }; 3422 3423 # n - single-step, but not into subs. Remember last command 3424 # was 'n'. 3425 $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' }; 3426 3427 } # PIPE: 3428 3429 # Make sure the flag that says "the debugger's running" is 3430 # still on, to make sure we get control again. 3431 $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd"; 3432 3433 # Run *our* eval that executes in the caller's context. 3434 &eval; 3435 3436 # Turn off the one-time-dump stuff now. 3437 if ($onetimeDump) { 3438 $onetimeDump = undef; 3439 $onetimedumpDepth = undef; 3440 } 3441 elsif ( $term_pid == $$ ) { 3442 eval { # May run under miniperl, when not available... 3443 STDOUT->flush(); 3444 STDERR->flush(); 3445 }; 3446 3447 # XXX If this is the master pid, print a newline. 3448 print $OUT "\n"; 3449 } 3450 } ## end while (($term || &setterm... 3451 3452 =head3 POST-COMMAND PROCESSING 3453 3454 After each command, we check to see if the command output was piped anywhere. 3455 If so, we go through the necessary code to unhook the pipe and go back to 3456 our standard filehandles for input and output. 3457 3458 =cut 3459 3460 continue { # CMD: 3461 3462 # At the end of every command: 3463 if ($piped) { 3464 3465 # Unhook the pipe mechanism now. 3466 if ( $pager =~ /^\|/ ) { 3467 3468 # No error from the child. 3469 $? = 0; 3470 3471 # we cannot warn here: the handle is missing --tchrist 3472 close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n"; 3473 3474 # most of the $? crud was coping with broken cshisms 3475 # $? is explicitly set to 0, so this never runs. 3476 if ($?) { 3477 print SAVEOUT "Pager `$pager' failed: "; 3478 if ( $? == -1 ) { 3479 print SAVEOUT "shell returned -1\n"; 3480 } 3481 elsif ( $? >> 8 ) { 3482 print SAVEOUT ( $? & 127 ) 3483 ? " (SIG#" . ( $? & 127 ) . ")" 3484 : "", ( $? & 128 ) ? " -- core dumped" : "", "\n"; 3485 } 3486 else { 3487 print SAVEOUT "status ", ( $? >> 8 ), "\n"; 3488 } 3489 } ## end if ($?) 3490 3491 # Reopen filehandle for our output (if we can) and 3492 # restore STDOUT (if we can). 3493 open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT"); 3494 open( STDOUT, ">&SAVEOUT" ) 3495 || &warn("Can't restore STDOUT"); 3496 3497 # Turn off pipe exception handler if necessary. 3498 $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch; 3499 3500 # Will stop ignoring SIGPIPE if done like nohup(1) 3501 # does SIGINT but Perl doesn't give us a choice. 3502 } ## end if ($pager =~ /^\|/) 3503 else { 3504 3505 # Non-piped "pager". Just restore STDOUT. 3506 open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT"); 3507 } 3508 3509 # Close filehandle pager was using, restore the normal one 3510 # if necessary, 3511 close(SAVEOUT); 3512 select($selected), $selected = "" unless $selected eq ""; 3513 3514 # No pipes now. 3515 $piped = ""; 3516 } ## end if ($piped) 3517 } # CMD: 3518 3519 =head3 COMMAND LOOP TERMINATION 3520 3521 When commands have finished executing, we come here. If the user closed the 3522 input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We 3523 evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, 3524 C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter. 3525 The interpreter will then execute the next line and then return control to us 3526 again. 3527 3528 =cut 3529 3530 # No more commands? Quit. 3531 $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF 3532 3533 # Evaluate post-prompt commands. 3534 foreach $evalarg (@$post) { 3535 &eval; 3536 } 3537 } # if ($single || $signal) 3538 3539 # Put the user's globals back where you found them. 3540 ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved; 3541 (); 3542 } ## end sub DB 3543 3544 # The following code may be executed now: 3545 # BEGIN {warn 4} 3546 3547 =head2 sub 3548 3549 C<sub> is called whenever a subroutine call happens in the program being 3550 debugged. The variable C<$DB::sub> contains the name of the subroutine 3551 being called. 3552 3553 The core function of this subroutine is to actually call the sub in the proper 3554 context, capturing its output. This of course causes C<DB::DB> to get called 3555 again, repeating until the subroutine ends and returns control to C<DB::sub> 3556 again. Once control returns, C<DB::sub> figures out whether or not to dump the 3557 return value, and returns its captured copy of the return value as its own 3558 return value. The value then feeds back into the program being debugged as if 3559 C<DB::sub> hadn't been there at all. 3560 3561 C<sub> does all the work of printing the subroutine entry and exit messages 3562 enabled by setting C<$frame>. It notes what sub the autoloader got called for, 3563 and also prints the return value if needed (for the C<r> command and if 3564 the 16 bit is set in C<$frame>). 3565 3566 It also tracks the subroutine call depth by saving the current setting of 3567 C<$single> in the C<@stack> package global; if this exceeds the value in 3568 C<$deep>, C<sub> automatically turns on printing of the current depth by 3569 setting the C<4> bit in C<$single>. In any case, it keeps the current setting 3570 of stop/don't stop on entry to subs set as it currently is set. 3571 3572 =head3 C<caller()> support 3573 3574 If C<caller()> is called from the package C<DB>, it provides some 3575 additional data, in the following order: 3576 3577 =over 4 3578 3579 =item * C<$package> 3580 3581 The package name the sub was in 3582 3583 =item * C<$filename> 3584 3585 The filename it was defined in 3586 3587 =item * C<$line> 3588 3589 The line number it was defined on 3590 3591 =item * C<$subroutine> 3592 3593 The subroutine name; C<(eval)> if an C<eval>(). 3594 3595 =item * C<$hasargs> 3596 3597 1 if it has arguments, 0 if not 3598 3599 =item * C<$wantarray> 3600 3601 1 if array context, 0 if scalar context 3602 3603 =item * C<$evaltext> 3604 3605 The C<eval>() text, if any (undefined for C<eval BLOCK>) 3606 3607 =item * C<$is_require> 3608 3609 frame was created by a C<use> or C<require> statement 3610 3611 =item * C<$hints> 3612 3613 pragma information; subject to change between versions 3614 3615 =item * C<$bitmask> 3616 3617 pragma information; subject to change between versions 3618 3619 =item * C<@DB::args> 3620 3621 arguments with which the subroutine was invoked 3622 3623 =back 3624 3625 =cut 3626 3627 sub sub { 3628 3629 # lock ourselves under threads 3630 lock($DBGR); 3631 3632 # Whether or not the autoloader was running, a scalar to put the 3633 # sub's return value in (if needed), and an array to put the sub's 3634 # return value in (if needed). 3635 my ( $al, $ret, @ret ) = ""; 3636 if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) { 3637 print "creating new thread\n"; 3638 } 3639 3640 # If the last ten characters are '::AUTOLOAD', note we've traced 3641 # into AUTOLOAD for $sub. 3642 if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { 3643 $al = " for $$sub" if defined $$sub; 3644 } 3645 3646 # We stack the stack pointer and then increment it to protect us 3647 # from a situation that might unwind a whole bunch of call frames 3648 # at once. Localizing the stack pointer means that it will automatically 3649 # unwind the same amount when multiple stack frames are unwound. 3650 local $stack_depth = $stack_depth + 1; # Protect from non-local exits 3651 3652 # Expand @stack. 3653 $#stack = $stack_depth; 3654 3655 # Save current single-step setting. 3656 $stack[-1] = $single; 3657 3658 # Turn off all flags except single-stepping. 3659 $single &= 1; 3660 3661 # If we've gotten really deeply recursed, turn on the flag that will 3662 # make us stop with the 'deep recursion' message. 3663 $single |= 4 if $stack_depth == $deep; 3664 3665 # If frame messages are on ... 3666 ( 3667 $frame & 4 # Extended frame entry message 3668 ? ( 3669 print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ), 3670 3671 # Why -1? But it works! :-( 3672 # Because print_trace will call add 1 to it and then call 3673 # dump_trace; this results in our skipping -1+1 = 0 stack frames 3674 # in dump_trace. 3675 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) 3676 ) 3677 : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" ) 3678 3679 # standard frame entry message 3680 ) 3681 if $frame; 3682 3683 # Determine the sub's return type,and capture approppriately. 3684 if (wantarray) { 3685 3686 # Called in array context. call sub and capture output. 3687 # DB::DB will recursively get control again if appropriate; we'll come 3688 # back here when the sub is finished. 3689 @ret = &$sub; 3690 3691 # Pop the single-step value back off the stack. 3692 $single |= $stack[ $stack_depth-- ]; 3693 3694 # Check for exit trace messages... 3695 ( 3696 $frame & 4 # Extended exit message 3697 ? ( 3698 print_lineinfo( ' ' x $stack_depth, "out " ), 3699 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) 3700 ) 3701 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" ) 3702 3703 # Standard exit message 3704 ) 3705 if $frame & 2; 3706 3707 # Print the return info if we need to. 3708 if ( $doret eq $stack_depth or $frame & 16 ) { 3709 3710 # Turn off output record separator. 3711 local $\ = ''; 3712 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 3713 3714 # Indent if we're printing because of $frame tracing. 3715 print $fh ' ' x $stack_depth if $frame & 16; 3716 3717 # Print the return value. 3718 print $fh "list context return from $sub:\n"; 3719 dumpit( $fh, \@ret ); 3720 3721 # And don't print it again. 3722 $doret = -2; 3723 } ## end if ($doret eq $stack_depth... 3724 # And we have to return the return value now. 3725 @ret; 3726 } ## end if (wantarray) 3727 3728 # Scalar context. 3729 else { 3730 if ( defined wantarray ) { 3731 3732 # Save the value if it's wanted at all. 3733 $ret = &$sub; 3734 } 3735 else { 3736 3737 # Void return, explicitly. 3738 &$sub; 3739 undef $ret; 3740 } 3741 3742 # Pop the single-step value off the stack. 3743 $single |= $stack[ $stack_depth-- ]; 3744 3745 # If we're doing exit messages... 3746 ( 3747 $frame & 4 # Extended messsages 3748 ? ( 3749 print_lineinfo( ' ' x $stack_depth, "out " ), 3750 print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) 3751 ) 3752 : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" ) 3753 3754 # Standard messages 3755 ) 3756 if $frame & 2; 3757 3758 # If we are supposed to show the return value... same as before. 3759 if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) { 3760 local $\ = ''; 3761 my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); 3762 print $fh ( ' ' x $stack_depth ) if $frame & 16; 3763 print $fh ( 3764 defined wantarray 3765 ? "scalar context return from $sub: " 3766 : "void context return from $sub\n" 3767 ); 3768 dumpit( $fh, $ret ) if defined wantarray; 3769 $doret = -2; 3770 } ## end if ($doret eq $stack_depth... 3771 3772 # Return the appropriate scalar value. 3773 $ret; 3774 } ## end else [ if (wantarray) 3775 } ## end sub sub 3776 3777 =head1 EXTENDED COMMAND HANDLING AND THE COMMAND API 3778 3779 In Perl 5.8.0, there was a major realignment of the commands and what they did, 3780 Most of the changes were to systematize the command structure and to eliminate 3781 commands that threw away user input without checking. 3782 3783 The following sections describe the code added to make it easy to support 3784 multiple command sets with conflicting command names. This section is a start 3785 at unifying all command processing to make it simpler to develop commands. 3786 3787 Note that all the cmd_[a-zA-Z] subroutines require the command name, a line 3788 number, and C<$dbline> (the current line) as arguments. 3789 3790 Support functions in this section which have multiple modes of failure C<die> 3791 on error; the rest simply return a false value. 3792 3793 The user-interface functions (all of the C<cmd_*> functions) just output 3794 error messages. 3795 3796 =head2 C<%set> 3797 3798 The C<%set> hash defines the mapping from command letter to subroutine 3799 name suffix. 3800 3801 C<%set> is a two-level hash, indexed by set name and then by command name. 3802 Note that trying to set the CommandSet to C<foobar> simply results in the 3803 5.8.0 command set being used, since there's no top-level entry for C<foobar>. 3804 3805 =cut 3806 3807 ### The API section 3808 3809 my %set = ( # 3810 'pre580' => { 3811 'a' => 'pre580_a', 3812 'A' => 'pre580_null', 3813 'b' => 'pre580_b', 3814 'B' => 'pre580_null', 3815 'd' => 'pre580_null', 3816 'D' => 'pre580_D', 3817 'h' => 'pre580_h', 3818 'M' => 'pre580_null', 3819 'O' => 'o', 3820 'o' => 'pre580_null', 3821 'v' => 'M', 3822 'w' => 'v', 3823 'W' => 'pre580_W', 3824 }, 3825 'pre590' => { 3826 '<' => 'pre590_prepost', 3827 '<<' => 'pre590_prepost', 3828 '>' => 'pre590_prepost', 3829 '>>' => 'pre590_prepost', 3830 '{' => 'pre590_prepost', 3831 '{{' => 'pre590_prepost', 3832 }, 3833 ); 3834 3835 =head2 C<cmd_wrapper()> (API) 3836 3837 C<cmd_wrapper()> allows the debugger to switch command sets 3838 depending on the value of the C<CommandSet> option. 3839 3840 It tries to look up the command in the C<%set> package-level I<lexical> 3841 (which means external entities can't fiddle with it) and create the name of 3842 the sub to call based on the value found in the hash (if it's there). I<All> 3843 of the commands to be handled in a set have to be added to C<%set>; if they 3844 aren't found, the 5.8.0 equivalent is called (if there is one). 3845 3846 This code uses symbolic references. 3847 3848 =cut 3849 3850 sub cmd_wrapper { 3851 my $cmd = shift; 3852 my $line = shift; 3853 my $dblineno = shift; 3854 3855 # Assemble the command subroutine's name by looking up the 3856 # command set and command name in %set. If we can't find it, 3857 # default to the older version of the command. 3858 my $call = 'cmd_' 3859 . ( $set{$CommandSet}{$cmd} 3860 || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) ); 3861 3862 # Call the command subroutine, call it by name. 3863 return &$call( $cmd, $line, $dblineno ); 3864 } ## end sub cmd_wrapper 3865 3866 =head3 C<cmd_a> (command) 3867 3868 The C<a> command handles pre-execution actions. These are associated with a 3869 particular line, so they're stored in C<%dbline>. We default to the current 3870 line if none is specified. 3871 3872 =cut 3873 3874 sub cmd_a { 3875 my $cmd = shift; 3876 my $line = shift || ''; # [.|line] expr 3877 my $dbline = shift; 3878 3879 # If it's dot (here), or not all digits, use the current line. 3880 $line =~ s/^(\.|(?:[^\d]))/$dbline/; 3881 3882 # Should be a line number followed by an expression. 3883 if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) { 3884 my ( $lineno, $expr ) = ( $1, $2 ); 3885 3886 # If we have an expression ... 3887 if ( length $expr ) { 3888 3889 # ... but the line isn't breakable, complain. 3890 if ( $dbline[$lineno] == 0 ) { 3891 print $OUT 3892 "Line $lineno($dbline[$lineno]) does not have an action?\n"; 3893 } 3894 else { 3895 3896 # It's executable. Record that the line has an action. 3897 $had_breakpoints{$filename} |= 2; 3898 3899 # Remove any action, temp breakpoint, etc. 3900 $dbline{$lineno} =~ s/\0[^\0]*//; 3901 3902 # Add the action to the line. 3903 $dbline{$lineno} .= "\0" . action($expr); 3904 } 3905 } ## end if (length $expr) 3906 } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/) 3907 else { 3908 3909 # Syntax wrong. 3910 print $OUT 3911 "Adding an action requires an optional lineno and an expression\n" 3912 ; # hint 3913 } 3914 } ## end sub cmd_a 3915 3916 =head3 C<cmd_A> (command) 3917 3918 Delete actions. Similar to above, except the delete code is in a separate 3919 subroutine, C<delete_action>. 3920 3921 =cut 3922 3923 sub cmd_A { 3924 my $cmd = shift; 3925 my $line = shift || ''; 3926 my $dbline = shift; 3927 3928 # Dot is this line. 3929 $line =~ s/^\./$dbline/; 3930 3931 # Call delete_action with a null param to delete them all. 3932 # The '1' forces the eval to be true. It'll be false only 3933 # if delete_action blows up for some reason, in which case 3934 # we print $@ and get out. 3935 if ( $line eq '*' ) { 3936 eval { &delete_action(); 1 } or print $OUT $@ and return; 3937 } 3938 3939 # There's a real line number. Pass it to delete_action. 3940 # Error trapping is as above. 3941 elsif ( $line =~ /^(\S.*)/ ) { 3942 eval { &delete_action($1); 1 } or print $OUT $@ and return; 3943 } 3944 3945 # Swing and a miss. Bad syntax. 3946 else { 3947 print $OUT 3948 "Deleting an action requires a line number, or '*' for all\n" ; # hint 3949 } 3950 } ## end sub cmd_A 3951 3952 =head3 C<delete_action> (API) 3953 3954 C<delete_action> accepts either a line number or C<undef>. If a line number 3955 is specified, we check for the line being executable (if it's not, it 3956 couldn't have had an action). If it is, we just take the action off (this 3957 will get any kind of an action, including breakpoints). 3958 3959 =cut 3960 3961 sub delete_action { 3962 my $i = shift; 3963 if ( defined($i) ) { 3964 3965 # Can there be one? 3966 die "Line $i has no action .\n" if $dbline[$i] == 0; 3967 3968 # Nuke whatever's there. 3969 $dbline{$i} =~ s/\0[^\0]*//; # \^a 3970 delete $dbline{$i} if $dbline{$i} eq ''; 3971 } 3972 else { 3973 print $OUT "Deleting all actions...\n"; 3974 for my $file ( keys %had_breakpoints ) { 3975 local *dbline = $main::{ '_<' . $file }; 3976 my $max = $#dbline; 3977 my $was; 3978 for ( $i = 1 ; $i <= $max ; $i++ ) { 3979 if ( defined $dbline{$i} ) { 3980 $dbline{$i} =~ s/\0[^\0]*//; 3981 delete $dbline{$i} if $dbline{$i} eq ''; 3982 } 3983 unless ( $had_breakpoints{$file} &= ~2 ) { 3984 delete $had_breakpoints{$file}; 3985 } 3986 } ## end for ($i = 1 ; $i <= $max... 3987 } ## end for my $file (keys %had_breakpoints) 3988 } ## end else [ if (defined($i)) 3989 } ## end sub delete_action 3990 3991 =head3 C<cmd_b> (command) 3992 3993 Set breakpoints. Since breakpoints can be set in so many places, in so many 3994 ways, conditionally or not, the breakpoint code is kind of complex. Mostly, 3995 we try to parse the command type, and then shuttle it off to an appropriate 3996 subroutine to actually do the work of setting the breakpoint in the right 3997 place. 3998 3999 =cut 4000 4001 sub cmd_b { 4002 my $cmd = shift; 4003 my $line = shift; # [.|line] [cond] 4004 my $dbline = shift; 4005 4006 # Make . the current line number if it's there.. 4007 $line =~ s/^\./$dbline/; 4008 4009 # No line number, no condition. Simple break on current line. 4010 if ( $line =~ /^\s*$/ ) { 4011 &cmd_b_line( $dbline, 1 ); 4012 } 4013 4014 # Break on load for a file. 4015 elsif ( $line =~ /^load\b\s*(.*)/ ) { 4016 my $file = $1; 4017 $file =~ s/\s+$//; 4018 &cmd_b_load($file); 4019 } 4020 4021 # b compile|postpone <some sub> [<condition>] 4022 # The interpreter actually traps this one for us; we just put the 4023 # necessary condition in the %postponed hash. 4024 elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { 4025 4026 # Capture the condition if there is one. Make it true if none. 4027 my $cond = length $3 ? $3 : '1'; 4028 4029 # Save the sub name and set $break to 1 if $1 was 'postpone', 0 4030 # if it was 'compile'. 4031 my ( $subname, $break ) = ( $2, $1 eq 'postpone' ); 4032 4033 # De-Perl4-ify the name - ' separators to ::. 4034 $subname =~ s/\'/::/g; 4035 4036 # Qualify it into the current package unless it's already qualified. 4037 $subname = "${'package'}::" . $subname unless $subname =~ /::/; 4038 4039 # Add main if it starts with ::. 4040 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 4041 4042 # Save the break type for this sub. 4043 $postponed{$subname} = $break ? "break +0 if $cond" : "compile"; 4044 } ## end elsif ($line =~ ... 4045 4046 # b <sub name> [<condition>] 4047 elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { 4048 4049 # 4050 $subname = $1; 4051 $cond = length $2 ? $2 : '1'; 4052 &cmd_b_sub( $subname, $cond ); 4053 } 4054 4055 # b <line> [<condition>]. 4056 elsif ( $line =~ /^(\d*)\s*(.*)/ ) { 4057 4058 # Capture the line. If none, it's the current line. 4059 $line = $1 || $dbline; 4060 4061 # If there's no condition, make it '1'. 4062 $cond = length $2 ? $2 : '1'; 4063 4064 # Break on line. 4065 &cmd_b_line( $line, $cond ); 4066 } 4067 4068 # Line didn't make sense. 4069 else { 4070 print "confused by line($line)?\n"; 4071 } 4072 } ## end sub cmd_b 4073 4074 =head3 C<break_on_load> (API) 4075 4076 We want to break when this file is loaded. Mark this file in the 4077 C<%break_on_load> hash, and note that it has a breakpoint in 4078 C<%had_breakpoints>. 4079 4080 =cut 4081 4082 sub break_on_load { 4083 my $file = shift; 4084 $break_on_load{$file} = 1; 4085 $had_breakpoints{$file} |= 1; 4086 } 4087 4088 =head3 C<report_break_on_load> (API) 4089 4090 Gives us an array of filenames that are set to break on load. Note that 4091 only files with break-on-load are in here, so simply showing the keys 4092 suffices. 4093 4094 =cut 4095 4096 sub report_break_on_load { 4097 sort keys %break_on_load; 4098 } 4099 4100 =head3 C<cmd_b_load> (command) 4101 4102 We take the file passed in and try to find it in C<%INC> (which maps modules 4103 to files they came from). We mark those files for break-on-load via 4104 C<break_on_load> and then report that it was done. 4105 4106 =cut 4107 4108 sub cmd_b_load { 4109 my $file = shift; 4110 my @files; 4111 4112 # This is a block because that way we can use a redo inside it 4113 # even without there being any looping structure at all outside it. 4114 { 4115 4116 # Save short name and full path if found. 4117 push @files, $file; 4118 push @files, $::INC{$file} if $::INC{$file}; 4119 4120 # Tack on .pm and do it again unless there was a '.' in the name 4121 # already. 4122 $file .= '.pm', redo unless $file =~ /\./; 4123 } 4124 4125 # Do the real work here. 4126 break_on_load($_) for @files; 4127 4128 # All the files that have break-on-load breakpoints. 4129 @files = report_break_on_load; 4130 4131 # Normalize for the purposes of our printing this. 4132 local $\ = ''; 4133 local $" = ' '; 4134 print $OUT "Will stop on load of `@files'.\n"; 4135 } ## end sub cmd_b_load 4136 4137 =head3 C<$filename_error> (API package global) 4138 4139 Several of the functions we need to implement in the API need to work both 4140 on the current file and on other files. We don't want to duplicate code, so 4141 C<$filename_error> is used to contain the name of the file that's being 4142 worked on (if it's not the current one). 4143 4144 We can now build functions in pairs: the basic function works on the current 4145 file, and uses C<$filename_error> as part of its error message. Since this is 4146 initialized to C<"">, no filename will appear when we are working on the 4147 current file. 4148 4149 The second function is a wrapper which does the following: 4150 4151 =over 4 4152 4153 =item * 4154 4155 Localizes C<$filename_error> and sets it to the name of the file to be processed. 4156 4157 =item * 4158 4159 Localizes the C<*dbline> glob and reassigns it to point to the file we want to process. 4160 4161 =item * 4162 4163 Calls the first function. 4164 4165 The first function works on the I<current> file (i.e., the one we changed to), 4166 and prints C<$filename_error> in the error message (the name of the other file) 4167 if it needs to. When the functions return, C<*dbline> is restored to point 4168 to the actual current file (the one we're executing in) and 4169 C<$filename_error> is restored to C<"">. This restores everything to 4170 the way it was before the second function was called at all. 4171 4172 See the comments in C<breakable_line> and C<breakable_line_in_file> for more 4173 details. 4174 4175 =back 4176 4177 =cut 4178 4179 $filename_error = ''; 4180 4181 =head3 breakable_line(from, to) (API) 4182 4183 The subroutine decides whether or not a line in the current file is breakable. 4184 It walks through C<@dbline> within the range of lines specified, looking for 4185 the first line that is breakable. 4186 4187 If C<$to> is greater than C<$from>, the search moves forwards, finding the 4188 first line I<after> C<$to> that's breakable, if there is one. 4189 4190 If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the 4191 first line I<before> C<$to> that's breakable, if there is one. 4192 4193 =cut 4194 4195 sub breakable_line { 4196 4197 my ( $from, $to ) = @_; 4198 4199 # $i is the start point. (Where are the FORTRAN programs of yesteryear?) 4200 my $i = $from; 4201 4202 # If there are at least 2 arguments, we're trying to search a range. 4203 if ( @_ >= 2 ) { 4204 4205 # $delta is positive for a forward search, negative for a backward one. 4206 my $delta = $from < $to ? +1 : -1; 4207 4208 # Keep us from running off the ends of the file. 4209 my $limit = $delta > 0 ? $#dbline : 1; 4210 4211 # Clever test. If you're a mathematician, it's obvious why this 4212 # test works. If not: 4213 # If $delta is positive (going forward), $limit will be $#dbline. 4214 # If $to is less than $limit, ($limit - $to) will be positive, times 4215 # $delta of 1 (positive), so the result is > 0 and we should use $to 4216 # as the stopping point. 4217 # 4218 # If $to is greater than $limit, ($limit - $to) is negative, 4219 # times $delta of 1 (positive), so the result is < 0 and we should 4220 # use $limit ($#dbline) as the stopping point. 4221 # 4222 # If $delta is negative (going backward), $limit will be 1. 4223 # If $to is zero, ($limit - $to) will be 1, times $delta of -1 4224 # (negative) so the result is > 0, and we use $to as the stopping 4225 # point. 4226 # 4227 # If $to is less than zero, ($limit - $to) will be positive, 4228 # times $delta of -1 (negative), so the result is not > 0, and 4229 # we use $limit (1) as the stopping point. 4230 # 4231 # If $to is 1, ($limit - $to) will zero, times $delta of -1 4232 # (negative), still giving zero; the result is not > 0, and 4233 # we use $limit (1) as the stopping point. 4234 # 4235 # if $to is >1, ($limit - $to) will be negative, times $delta of -1 4236 # (negative), giving a positive (>0) value, so we'll set $limit to 4237 # $to. 4238 4239 $limit = $to if ( $limit - $to ) * $delta > 0; 4240 4241 # The real search loop. 4242 # $i starts at $from (the point we want to start searching from). 4243 # We move through @dbline in the appropriate direction (determined 4244 # by $delta: either -1 (back) or +1 (ahead). 4245 # We stay in as long as we haven't hit an executable line 4246 # ($dbline[$i] == 0 means not executable) and we haven't reached 4247 # the limit yet (test similar to the above). 4248 $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0; 4249 4250 } ## end if (@_ >= 2) 4251 4252 # If $i points to a line that is executable, return that. 4253 return $i unless $dbline[$i] == 0; 4254 4255 # Format the message and print it: no breakable lines in range. 4256 my ( $pl, $upto ) = ( '', '' ); 4257 ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to; 4258 4259 # If there's a filename in filename_error, we'll see it. 4260 # If not, not. 4261 die "Line$pl $from$upto$filename_error not breakable\n"; 4262 } ## end sub breakable_line 4263 4264 =head3 breakable_line_in_filename(file, from, to) (API) 4265 4266 Like C<breakable_line>, but look in another file. 4267 4268 =cut 4269 4270 sub breakable_line_in_filename { 4271 4272 # Capture the file name. 4273 my ($f) = shift; 4274 4275 # Swap the magic line array over there temporarily. 4276 local *dbline = $main::{ '_<' . $f }; 4277 4278 # If there's an error, it's in this other file. 4279 local $filename_error = " of `$f'"; 4280 4281 # Find the breakable line. 4282 breakable_line(@_); 4283 4284 # *dbline and $filename_error get restored when this block ends. 4285 4286 } ## end sub breakable_line_in_filename 4287 4288 =head3 break_on_line(lineno, [condition]) (API) 4289 4290 Adds a breakpoint with the specified condition (or 1 if no condition was 4291 specified) to the specified line. Dies if it can't. 4292 4293 =cut 4294 4295 sub break_on_line { 4296 my ( $i, $cond ) = @_; 4297 4298 # Always true if no condition supplied. 4299 $cond = 1 unless @_ >= 2; 4300 4301 my $inii = $i; 4302 my $after = ''; 4303 my $pl = ''; 4304 4305 # Woops, not a breakable line. $filename_error allows us to say 4306 # if it was in a different file. 4307 die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0; 4308 4309 # Mark this file as having breakpoints in it. 4310 $had_breakpoints{$filename} |= 1; 4311 4312 # If there is an action or condition here already ... 4313 if ( $dbline{$i} ) { 4314 4315 # ... swap this condition for the existing one. 4316 $dbline{$i} =~ s/^[^\0]*/$cond/; 4317 } 4318 else { 4319 4320 # Nothing here - just add the condition. 4321 $dbline{$i} = $cond; 4322 } 4323 } ## end sub break_on_line 4324 4325 =head3 cmd_b_line(line, [condition]) (command) 4326 4327 Wrapper for C<break_on_line>. Prints the failure message if it 4328 doesn't work. 4329 4330 =cut 4331 4332 sub cmd_b_line { 4333 eval { break_on_line(@_); 1 } or do { 4334 local $\ = ''; 4335 print $OUT $@ and return; 4336 }; 4337 } ## end sub cmd_b_line 4338 4339 =head3 break_on_filename_line(file, line, [condition]) (API) 4340 4341 Switches to the file specified and then calls C<break_on_line> to set 4342 the breakpoint. 4343 4344 =cut 4345 4346 sub break_on_filename_line { 4347 my ( $f, $i, $cond ) = @_; 4348 4349 # Always true if condition left off. 4350 $cond = 1 unless @_ >= 3; 4351 4352 # Switch the magical hash temporarily. 4353 local *dbline = $main::{ '_<' . $f }; 4354 4355 # Localize the variables that break_on_line uses to make its message. 4356 local $filename_error = " of `$f'"; 4357 local $filename = $f; 4358 4359 # Add the breakpoint. 4360 break_on_line( $i, $cond ); 4361 } ## end sub break_on_filename_line 4362 4363 =head3 break_on_filename_line_range(file, from, to, [condition]) (API) 4364 4365 Switch to another file, search the range of lines specified for an 4366 executable one, and put a breakpoint on the first one you find. 4367 4368 =cut 4369 4370 sub break_on_filename_line_range { 4371 my ( $f, $from, $to, $cond ) = @_; 4372 4373 # Find a breakable line if there is one. 4374 my $i = breakable_line_in_filename( $f, $from, $to ); 4375 4376 # Always true if missing. 4377 $cond = 1 unless @_ >= 3; 4378 4379 # Add the breakpoint. 4380 break_on_filename_line( $f, $i, $cond ); 4381 } ## end sub break_on_filename_line_range 4382 4383 =head3 subroutine_filename_lines(subname, [condition]) (API) 4384 4385 Search for a subroutine within a given file. The condition is ignored. 4386 Uses C<find_sub> to locate the desired subroutine. 4387 4388 =cut 4389 4390 sub subroutine_filename_lines { 4391 my ( $subname, $cond ) = @_; 4392 4393 # Returned value from find_sub() is fullpathname:startline-endline. 4394 # The match creates the list (fullpathname, start, end). Falling off 4395 # the end of the subroutine returns this implicitly. 4396 find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/; 4397 } ## end sub subroutine_filename_lines 4398 4399 =head3 break_subroutine(subname) (API) 4400 4401 Places a break on the first line possible in the specified subroutine. Uses 4402 C<subroutine_filename_lines> to find the subroutine, and 4403 C<break_on_filename_line_range> to place the break. 4404 4405 =cut 4406 4407 sub break_subroutine { 4408 my $subname = shift; 4409 4410 # Get filename, start, and end. 4411 my ( $file, $s, $e ) = subroutine_filename_lines($subname) 4412 or die "Subroutine $subname not found.\n"; 4413 4414 # Null condition changes to '1' (always true). 4415 $cond = 1 unless @_ >= 2; 4416 4417 # Put a break the first place possible in the range of lines 4418 # that make up this subroutine. 4419 break_on_filename_line_range( $file, $s, $e, @_ ); 4420 } ## end sub break_subroutine 4421 4422 =head3 cmd_b_sub(subname, [condition]) (command) 4423 4424 We take the incoming subroutine name and fully-qualify it as best we can. 4425 4426 =over 4 4427 4428 =item 1. If it's already fully-qualified, leave it alone. 4429 4430 =item 2. Try putting it in the current package. 4431 4432 =item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there. 4433 4434 =item 4. If it starts with '::', put it in 'main::'. 4435 4436 =back 4437 4438 After all this cleanup, we call C<break_subroutine> to try to set the 4439 breakpoint. 4440 4441 =cut 4442 4443 sub cmd_b_sub { 4444 my ( $subname, $cond ) = @_; 4445 4446 # Add always-true condition if we have none. 4447 $cond = 1 unless @_ >= 2; 4448 4449 # If the subname isn't a code reference, qualify it so that 4450 # break_subroutine() will work right. 4451 unless ( ref $subname eq 'CODE' ) { 4452 4453 # Not Perl4. 4454 $subname =~ s/\'/::/g; 4455 my $s = $subname; 4456 4457 # Put it in this package unless it's already qualified. 4458 $subname = "${'package'}::" . $subname 4459 unless $subname =~ /::/; 4460 4461 # Requalify it into CORE::GLOBAL if qualifying it into this 4462 # package resulted in its not being defined, but only do so 4463 # if it really is in CORE::GLOBAL. 4464 $subname = "CORE::GLOBAL::$s" 4465 if not defined &$subname 4466 and $s !~ /::/ 4467 and defined &{"CORE::GLOBAL::$s"}; 4468 4469 # Put it in package 'main' if it has a leading ::. 4470 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 4471 4472 } ## end unless (ref $subname eq 'CODE') 4473 4474 # Try to set the breakpoint. 4475 eval { break_subroutine( $subname, $cond ); 1 } or do { 4476 local $\ = ''; 4477 print $OUT $@ and return; 4478 } 4479 } ## end sub cmd_b_sub 4480 4481 =head3 C<cmd_B> - delete breakpoint(s) (command) 4482 4483 The command mostly parses the command line and tries to turn the argument 4484 into a line spec. If it can't, it uses the current line. It then calls 4485 C<delete_breakpoint> to actually do the work. 4486 4487 If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments, 4488 thereby deleting all the breakpoints. 4489 4490 =cut 4491 4492 sub cmd_B { 4493 my $cmd = shift; 4494 4495 # No line spec? Use dbline. 4496 # If there is one, use it if it's non-zero, or wipe it out if it is. 4497 my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || ''; 4498 my $dbline = shift; 4499 4500 # If the line was dot, make the line the current one. 4501 $line =~ s/^\./$dbline/; 4502 4503 # If it's * we're deleting all the breakpoints. 4504 if ( $line eq '*' ) { 4505 eval { &delete_breakpoint(); 1 } or print $OUT $@ and return; 4506 } 4507 4508 # If there is a line spec, delete the breakpoint on that line. 4509 elsif ( $line =~ /^(\S.*)/ ) { 4510 eval { &delete_breakpoint( $line || $dbline ); 1 } or do { 4511 local $\ = ''; 4512 print $OUT $@ and return; 4513 }; 4514 } ## end elsif ($line =~ /^(\S.*)/) 4515 4516 # No line spec. 4517 else { 4518 print $OUT 4519 "Deleting a breakpoint requires a line number, or '*' for all\n" 4520 ; # hint 4521 } 4522 } ## end sub cmd_B 4523 4524 =head3 delete_breakpoint([line]) (API) 4525 4526 This actually does the work of deleting either a single breakpoint, or all 4527 of them. 4528 4529 For a single line, we look for it in C<@dbline>. If it's nonbreakable, we 4530 just drop out with a message saying so. If it is, we remove the condition 4531 part of the 'condition\0action' that says there's a breakpoint here. If, 4532 after we've done that, there's nothing left, we delete the corresponding 4533 line in C<%dbline> to signal that no action needs to be taken for this line. 4534 4535 For all breakpoints, we iterate through the keys of C<%had_breakpoints>, 4536 which lists all currently-loaded files which have breakpoints. We then look 4537 at each line in each of these files, temporarily switching the C<%dbline> 4538 and C<@dbline> structures to point to the files in question, and do what 4539 we did in the single line case: delete the condition in C<@dbline>, and 4540 delete the key in C<%dbline> if nothing's left. 4541 4542 We then wholesale delete C<%postponed>, C<%postponed_file>, and 4543 C<%break_on_load>, because these structures contain breakpoints for files 4544 and code that haven't been loaded yet. We can just kill these off because there 4545 are no magical debugger structures associated with them. 4546 4547 =cut 4548 4549 sub delete_breakpoint { 4550 my $i = shift; 4551 4552 # If we got a line, delete just that one. 4553 if ( defined($i) ) { 4554 4555 # Woops. This line wasn't breakable at all. 4556 die "Line $i not breakable.\n" if $dbline[$i] == 0; 4557 4558 # Kill the condition, but leave any action. 4559 $dbline{$i} =~ s/^[^\0]*//; 4560 4561 # Remove the entry entirely if there's no action left. 4562 delete $dbline{$i} if $dbline{$i} eq ''; 4563 } 4564 4565 # No line; delete them all. 4566 else { 4567 print $OUT "Deleting all breakpoints...\n"; 4568 4569 # %had_breakpoints lists every file that had at least one 4570 # breakpoint in it. 4571 for my $file ( keys %had_breakpoints ) { 4572 4573 # Switch to the desired file temporarily. 4574 local *dbline = $main::{ '_<' . $file }; 4575 4576 my $max = $#dbline; 4577 my $was; 4578 4579 # For all lines in this file ... 4580 for ( $i = 1 ; $i <= $max ; $i++ ) { 4581 4582 # If there's a breakpoint or action on this line ... 4583 if ( defined $dbline{$i} ) { 4584 4585 # ... remove the breakpoint. 4586 $dbline{$i} =~ s/^[^\0]+//; 4587 if ( $dbline{$i} =~ s/^\0?$// ) { 4588 4589 # Remove the entry altogether if no action is there. 4590 delete $dbline{$i}; 4591 } 4592 } ## end if (defined $dbline{$i... 4593 } ## end for ($i = 1 ; $i <= $max... 4594 4595 # If, after we turn off the "there were breakpoints in this file" 4596 # bit, the entry in %had_breakpoints for this file is zero, 4597 # we should remove this file from the hash. 4598 if ( not $had_breakpoints{$file} &= ~1 ) { 4599 delete $had_breakpoints{$file}; 4600 } 4601 } ## end for my $file (keys %had_breakpoints) 4602 4603 # Kill off all the other breakpoints that are waiting for files that 4604 # haven't been loaded yet. 4605 undef %postponed; 4606 undef %postponed_file; 4607 undef %break_on_load; 4608 } ## end else [ if (defined($i)) 4609 } ## end sub delete_breakpoint 4610 4611 =head3 cmd_stop (command) 4612 4613 This is meant to be part of the new command API, but it isn't called or used 4614 anywhere else in the debugger. XXX It is probably meant for use in development 4615 of new commands. 4616 4617 =cut 4618 4619 sub cmd_stop { # As on ^C, but not signal-safy. 4620 $signal = 1; 4621 } 4622 4623 =head3 C<cmd_e> - threads 4624 4625 Display the current thread id: 4626 4627 e 4628 4629 This could be how (when implemented) to send commands to this thread id (e cmd) 4630 or that thread id (e tid cmd). 4631 4632 =cut 4633 4634 sub cmd_e { 4635 my $cmd = shift; 4636 my $line = shift; 4637 unless (exists($INC{'threads.pm'})) { 4638 print "threads not loaded($ENV{PERL5DB_THREADED}) 4639 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 4640 } else { 4641 my $tid = threads->tid; 4642 print "thread id: $tid\n"; 4643 } 4644 } ## end sub cmd_e 4645 4646 =head3 C<cmd_E> - list of thread ids 4647 4648 Display the list of available thread ids: 4649 4650 E 4651 4652 This could be used (when implemented) to send commands to all threads (E cmd). 4653 4654 =cut 4655 4656 sub cmd_E { 4657 my $cmd = shift; 4658 my $line = shift; 4659 unless (exists($INC{'threads.pm'})) { 4660 print "threads not loaded($ENV{PERL5DB_THREADED}) 4661 please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; 4662 } else { 4663 my $tid = threads->tid; 4664 print "thread ids: ".join(', ', 4665 map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list 4666 )."\n"; 4667 } 4668 } ## end sub cmd_E 4669 4670 =head3 C<cmd_h> - help command (command) 4671 4672 Does the work of either 4673 4674 =over 4 4675 4676 =item * 4677 4678 Showing all the debugger help 4679 4680 =item * 4681 4682 Showing help for a specific command 4683 4684 =back 4685 4686 =cut 4687 4688 sub cmd_h { 4689 my $cmd = shift; 4690 4691 # If we have no operand, assume null. 4692 my $line = shift || ''; 4693 4694 # 'h h'. Print the long-format help. 4695 if ( $line =~ /^h\s*/ ) { 4696 print_help($help); 4697 } 4698 4699 # 'h <something>'. Search for the command and print only its help. 4700 elsif ( $line =~ /^(\S.*)$/ ) { 4701 4702 # support long commands; otherwise bogus errors 4703 # happen when you ask for h on <CR> for example 4704 my $asked = $1; # the command requested 4705 # (for proper error message) 4706 4707 my $qasked = quotemeta($asked); # for searching; we don't 4708 # want to use it as a pattern. 4709 # XXX: finds CR but not <CR> 4710 4711 # Search the help string for the command. 4712 if ( 4713 $help =~ /^ # Start of a line 4714 <? # Optional '<' 4715 (?:[IB]<) # Optional markup 4716 $qasked # The requested command 4717 /mx 4718 ) 4719 { 4720 4721 # It's there; pull it out and print it. 4722 while ( 4723 $help =~ /^ 4724 (<? # Optional '<' 4725 (?:[IB]<) # Optional markup 4726 $qasked # The command 4727 ([\s\S]*?) # Description line(s) 4728 \n) # End of last description line 4729 (?!\s) # Next line not starting with 4730 # whitespace 4731 /mgx 4732 ) 4733 { 4734 print_help($1); 4735 } 4736 } 4737 4738 # Not found; not a debugger command. 4739 else { 4740 print_help("B<$asked> is not a debugger command.\n"); 4741 } 4742 } ## end elsif ($line =~ /^(\S.*)$/) 4743 4744 # 'h' - print the summary help. 4745 else { 4746 print_help($summary); 4747 } 4748 } ## end sub cmd_h 4749 4750 =head3 C<cmd_i> - inheritance display 4751 4752 Display the (nested) parentage of the module or object given. 4753 4754 =cut 4755 4756 sub cmd_i { 4757 my $cmd = shift; 4758 my $line = shift; 4759 eval { require Class::ISA }; 4760 if ($@) { 4761 &warn( $@ =~ /locate/ 4762 ? "Class::ISA module not found - please install\n" 4763 : $@ ); 4764 } 4765 else { 4766 ISA: 4767 foreach my $isa ( split( /\s+/, $line ) ) { 4768 $evalarg = $isa; 4769 ($isa) = &eval; 4770 no strict 'refs'; 4771 print join( 4772 ', ', 4773 map { # snaffled unceremoniously from Class::ISA 4774 "$_" 4775 . ( 4776 defined( ${"$_\::VERSION"} ) 4777 ? ' ' . ${"$_\::VERSION"} 4778 : undef ) 4779 } Class::ISA::self_and_super_path(ref($isa) || $isa) 4780 ); 4781 print "\n"; 4782 } 4783 } 4784 } ## end sub cmd_i 4785 4786 =head3 C<cmd_l> - list lines (command) 4787 4788 Most of the command is taken up with transforming all the different line 4789 specification syntaxes into 'start-stop'. After that is done, the command 4790 runs a loop over C<@dbline> for the specified range of lines. It handles 4791 the printing of each line and any markers (C<==E<gt>> for current line, 4792 C<b> for break on this line, C<a> for action on this line, C<:> for this 4793 line breakable). 4794 4795 We save the last line listed in the C<$start> global for further listing 4796 later. 4797 4798 =cut 4799 4800 sub cmd_l { 4801 my $current_line = $line; 4802 my $cmd = shift; 4803 my $line = shift; 4804 4805 # If this is '-something', delete any spaces after the dash. 4806 $line =~ s/^-\s*$/-/; 4807 4808 # If the line is '$something', assume this is a scalar containing a 4809 # line number. 4810 if ( $line =~ /^(\$.*)/s ) { 4811 4812 # Set up for DB::eval() - evaluate in *user* context. 4813 $evalarg = $1; 4814 # $evalarg = $2; 4815 my ($s) = &eval; 4816 4817 # Ooops. Bad scalar. 4818 print( $OUT "Error: $@\n" ), next CMD if $@; 4819 4820 # Good scalar. If it's a reference, find what it points to. 4821 $s = CvGV_name($s); 4822 print( $OUT "Interpreted as: $1 $s\n" ); 4823 $line = "$1 $s"; 4824 4825 # Call self recursively to really do the command. 4826 &cmd_l( 'l', $s ); 4827 } ## end if ($line =~ /^(\$.*)/s) 4828 4829 # l name. Try to find a sub by that name. 4830 elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) { 4831 my $s = $subname = $1; 4832 4833 # De-Perl4. 4834 $subname =~ s/\'/::/; 4835 4836 # Put it in this package unless it starts with ::. 4837 $subname = $package . "::" . $subname unless $subname =~ /::/; 4838 4839 # Put it in CORE::GLOBAL if t doesn't start with :: and 4840 # it doesn't live in this package and it lives in CORE::GLOBAL. 4841 $subname = "CORE::GLOBAL::$s" 4842 if not defined &$subname 4843 and $s !~ /::/ 4844 and defined &{"CORE::GLOBAL::$s"}; 4845 4846 # Put leading '::' names into 'main::'. 4847 $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; 4848 4849 # Get name:start-stop from find_sub, and break this up at 4850 # colons. 4851 @pieces = split( /:/, find_sub($subname) || $sub{$subname} ); 4852 4853 # Pull off start-stop. 4854 $subrange = pop @pieces; 4855 4856 # If the name contained colons, the split broke it up. 4857 # Put it back together. 4858 $file = join( ':', @pieces ); 4859 4860 # If we're not in that file, switch over to it. 4861 if ( $file ne $filename ) { 4862 print $OUT "Switching to file '$file'.\n" 4863 unless $slave_editor; 4864 4865 # Switch debugger's magic structures. 4866 *dbline = $main::{ '_<' . $file }; 4867 $max = $#dbline; 4868 $filename = $file; 4869 } ## end if ($file ne $filename) 4870 4871 # Subrange is 'start-stop'. If this is less than a window full, 4872 # swap it to 'start+', which will list a window from the start point. 4873 if ($subrange) { 4874 if ( eval($subrange) < -$window ) { 4875 $subrange =~ s/-.*/+/; 4876 } 4877 4878 # Call self recursively to list the range. 4879 $line = $subrange; 4880 &cmd_l( 'l', $subrange ); 4881 } ## end if ($subrange) 4882 4883 # Couldn't find it. 4884 else { 4885 print $OUT "Subroutine $subname not found.\n"; 4886 } 4887 } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s) 4888 4889 # Bare 'l' command. 4890 elsif ( $line =~ /^\s*$/ ) { 4891 4892 # Compute new range to list. 4893 $incr = $window - 1; 4894 $line = $start . '-' . ( $start + $incr ); 4895 4896 # Recurse to do it. 4897 &cmd_l( 'l', $line ); 4898 } 4899 4900 # l [start]+number_of_lines 4901 elsif ( $line =~ /^(\d*)\+(\d*)$/ ) { 4902 4903 # Don't reset start for 'l +nnn'. 4904 $start = $1 if $1; 4905 4906 # Increment for list. Use window size if not specified. 4907 # (Allows 'l +' to work.) 4908 $incr = $2; 4909 $incr = $window - 1 unless $incr; 4910 4911 # Create a line range we'll understand, and recurse to do it. 4912 $line = $start . '-' . ( $start + $incr ); 4913 &cmd_l( 'l', $line ); 4914 } ## end elsif ($line =~ /^(\d*)\+(\d*)$/) 4915 4916 # l start-stop or l start,stop 4917 elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) { 4918 4919 # Determine end point; use end of file if not specified. 4920 $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 ); 4921 4922 # Go on to the end, and then stop. 4923 $end = $max if $end > $max; 4924 4925 # Determine start line. 4926 $i = $2; 4927 $i = $line if $i eq '.'; 4928 $i = 1 if $i < 1; 4929 $incr = $end - $i; 4930 4931 # If we're running under a slave editor, force it to show the lines. 4932 if ($slave_editor) { 4933 print $OUT "\032\032$filename:$i:0\n"; 4934 $i = $end; 4935 } 4936 4937 # We're doing it ourselves. We want to show the line and special 4938 # markers for: 4939 # - the current line in execution 4940 # - whether a line is breakable or not 4941 # - whether a line has a break or not 4942 # - whether a line has an action or not 4943 else { 4944 for ( ; $i <= $end ; $i++ ) { 4945 4946 # Check for breakpoints and actions. 4947 my ( $stop, $action ); 4948 ( $stop, $action ) = split( /\0/, $dbline{$i} ) 4949 if $dbline{$i}; 4950 4951 # ==> if this is the current line in execution, 4952 # : if it's breakable. 4953 $arrow = 4954 ( $i == $current_line and $filename eq $filename_ini ) 4955 ? '==>' 4956 : ( $dbline[$i] + 0 ? ':' : ' ' ); 4957 4958 # Add break and action indicators. 4959 $arrow .= 'b' if $stop; 4960 $arrow .= 'a' if $action; 4961 4962 # Print the line. 4963 print $OUT "$i$arrow\t", $dbline[$i]; 4964 4965 # Move on to the next line. Drop out on an interrupt. 4966 $i++, last if $signal; 4967 } ## end for (; $i <= $end ; $i++) 4968 4969 # Line the prompt up; print a newline if the last line listed 4970 # didn't have a newline. 4971 print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/; 4972 } ## end else [ if ($slave_editor) 4973 4974 # Save the point we last listed to in case another relative 'l' 4975 # command is desired. Don't let it run off the end. 4976 $start = $i; 4977 $start = $max if $start > $max; 4978 } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/) 4979 } ## end sub cmd_l 4980 4981 =head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command) 4982 4983 To list breakpoints, the command has to look determine where all of them are 4984 first. It starts a C<%had_breakpoints>, which tells us what all files have 4985 breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the 4986 magic source and breakpoint data structures) to the file, and then look 4987 through C<%dbline> for lines with breakpoints and/or actions, listing them 4988 out. We look through C<%postponed> not-yet-compiled subroutines that have 4989 breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files 4990 that have breakpoints. 4991 4992 Watchpoints are simpler: we just list the entries in C<@to_watch>. 4993 4994 =cut 4995 4996 sub cmd_L { 4997 my $cmd = shift; 4998 4999 # If no argument, list everything. Pre-5.8.0 version always lists 5000 # everything 5001 my $arg = shift || 'abw'; 5002 $arg = 'abw' unless $CommandSet eq '580'; # sigh... 5003 5004 # See what is wanted. 5005 my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0; 5006 my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0; 5007 my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0; 5008 5009 # Breaks and actions are found together, so we look in the same place 5010 # for both. 5011 if ( $break_wanted or $action_wanted ) { 5012 5013 # Look in all the files with breakpoints... 5014 for my $file ( keys %had_breakpoints ) { 5015 5016 # Temporary switch to this file. 5017 local *dbline = $main::{ '_<' . $file }; 5018 5019 # Set up to look through the whole file. 5020 my $max = $#dbline; 5021 my $was; # Flag: did we print something 5022 # in this file? 5023 5024 # For each line in the file ... 5025 for ( $i = 1 ; $i <= $max ; $i++ ) { 5026 5027 # We've got something on this line. 5028 if ( defined $dbline{$i} ) { 5029 5030 # Print the header if we haven't. 5031 print $OUT "$file:\n" unless $was++; 5032 5033 # Print the line. 5034 print $OUT " $i:\t", $dbline[$i]; 5035 5036 # Pull out the condition and the action. 5037 ( $stop, $action ) = split( /\0/, $dbline{$i} ); 5038 5039 # Print the break if there is one and it's wanted. 5040 print $OUT " break if (", $stop, ")\n" 5041 if $stop 5042 and $break_wanted; 5043 5044 # Print the action if there is one and it's wanted. 5045 print $OUT " action: ", $action, "\n" 5046 if $action 5047 and $action_wanted; 5048 5049 # Quit if the user hit interrupt. 5050 last if $signal; 5051 } ## end if (defined $dbline{$i... 5052 } ## end for ($i = 1 ; $i <= $max... 5053 } ## end for my $file (keys %had_breakpoints) 5054 } ## end if ($break_wanted or $action_wanted) 5055 5056 # Look for breaks in not-yet-compiled subs: 5057 if ( %postponed and $break_wanted ) { 5058 print $OUT "Postponed breakpoints in subroutines:\n"; 5059 my $subname; 5060 for $subname ( keys %postponed ) { 5061 print $OUT " $subname\t$postponed{$subname}\n"; 5062 last if $signal; 5063 } 5064 } ## end if (%postponed and $break_wanted) 5065 5066 # Find files that have not-yet-loaded breaks: 5067 my @have = map { # Combined keys 5068 keys %{ $postponed_file{$_} } 5069 } keys %postponed_file; 5070 5071 # If there are any, list them. 5072 if ( @have and ( $break_wanted or $action_wanted ) ) { 5073 print $OUT "Postponed breakpoints in files:\n"; 5074 my ( $file, $line ); 5075 5076 for $file ( keys %postponed_file ) { 5077 my $db = $postponed_file{$file}; 5078 print $OUT " $file:\n"; 5079 for $line ( sort { $a <=> $b } keys %$db ) { 5080 print $OUT " $line:\n"; 5081 my ( $stop, $action ) = split( /\0/, $$db{$line} ); 5082 print $OUT " break if (", $stop, ")\n" 5083 if $stop 5084 and $break_wanted; 5085 print $OUT " action: ", $action, "\n" 5086 if $action 5087 and $action_wanted; 5088 last if $signal; 5089 } ## end for $line (sort { $a <=>... 5090 last if $signal; 5091 } ## end for $file (keys %postponed_file) 5092 } ## end if (@have and ($break_wanted... 5093 if ( %break_on_load and $break_wanted ) { 5094 print $OUT "Breakpoints on load:\n"; 5095 my $file; 5096 for $file ( keys %break_on_load ) { 5097 print $OUT " $file\n"; 5098 last if $signal; 5099 } 5100 } ## end if (%break_on_load and... 5101 if ($watch_wanted) { 5102 if ( $trace & 2 ) { 5103 print $OUT "Watch-expressions:\n" if @to_watch; 5104 for my $expr (@to_watch) { 5105 print $OUT " $expr\n"; 5106 last if $signal; 5107 } 5108 } ## end if ($trace & 2) 5109 } ## end if ($watch_wanted) 5110 } ## end sub cmd_L 5111 5112 =head3 C<cmd_M> - list modules (command) 5113 5114 Just call C<list_modules>. 5115 5116 =cut 5117 5118 sub cmd_M { 5119 &list_modules(); 5120 } 5121 5122 =head3 C<cmd_o> - options (command) 5123 5124 If this is just C<o> by itself, we list the current settings via 5125 C<dump_option>. If there's a nonblank value following it, we pass that on to 5126 C<parse_options> for processing. 5127 5128 =cut 5129 5130 sub cmd_o { 5131 my $cmd = shift; 5132 my $opt = shift || ''; # opt[=val] 5133 5134 # Nonblank. Try to parse and process. 5135 if ( $opt =~ /^(\S.*)/ ) { 5136 &parse_options($1); 5137 } 5138 5139 # Blank. List the current option settings. 5140 else { 5141 for (@options) { 5142 &dump_option($_); 5143 } 5144 } 5145 } ## end sub cmd_o 5146 5147 =head3 C<cmd_O> - nonexistent in 5.8.x (command) 5148 5149 Advises the user that the O command has been renamed. 5150 5151 =cut 5152 5153 sub cmd_O { 5154 print $OUT "The old O command is now the o command.\n"; # hint 5155 print $OUT "Use 'h' to get current command help synopsis or\n"; # 5156 print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; # 5157 } 5158 5159 =head3 C<cmd_v> - view window (command) 5160 5161 Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to 5162 move back a few lines to list the selected line in context. Uses C<cmd_l> 5163 to do the actual listing after figuring out the range of line to request. 5164 5165 =cut 5166 5167 sub cmd_v { 5168 my $cmd = shift; 5169 my $line = shift; 5170 5171 # Extract the line to list around. (Astute readers will have noted that 5172 # this pattern will match whether or not a numeric line is specified, 5173 # which means that we'll always enter this loop (though a non-numeric 5174 # argument results in no action at all)). 5175 if ( $line =~ /^(\d*)$/ ) { 5176 5177 # Total number of lines to list (a windowful). 5178 $incr = $window - 1; 5179 5180 # Set the start to the argument given (if there was one). 5181 $start = $1 if $1; 5182 5183 # Back up by the context amount. 5184 $start -= $preview; 5185 5186 # Put together a linespec that cmd_l will like. 5187 $line = $start . '-' . ( $start + $incr ); 5188 5189 # List the lines. 5190 &cmd_l( 'l', $line ); 5191 } ## end if ($line =~ /^(\d*)$/) 5192 } ## end sub cmd_v 5193 5194 =head3 C<cmd_w> - add a watch expression (command) 5195 5196 The 5.8 version of this command adds a watch expression if one is specified; 5197 it does nothing if entered with no operands. 5198 5199 We extract the expression, save it, evaluate it in the user's context, and 5200 save the value. We'll re-evaluate it each time the debugger passes a line, 5201 and will stop (see the code at the top of the command loop) if the value 5202 of any of the expressions changes. 5203 5204 =cut 5205 5206 sub cmd_w { 5207 my $cmd = shift; 5208 5209 # Null expression if no arguments. 5210 my $expr = shift || ''; 5211 5212 # If expression is not null ... 5213 if ( $expr =~ /^(\S.*)/ ) { 5214 5215 # ... save it. 5216 push @to_watch, $expr; 5217 5218 # Parameterize DB::eval and call it to get the expression's value 5219 # in the user's context. This version can handle expressions which 5220 # return a list value. 5221 $evalarg = $expr; 5222 my ($val) = join( ' ', &eval ); 5223 $val = ( defined $val ) ? "'$val'" : 'undef'; 5224 5225 # Save the current value of the expression. 5226 push @old_watch, $val; 5227 5228 # We are now watching expressions. 5229 $trace |= 2; 5230 } ## end if ($expr =~ /^(\S.*)/) 5231 5232 # You have to give one to get one. 5233 else { 5234 print $OUT "Adding a watch-expression requires an expression\n"; # hint 5235 } 5236 } ## end sub cmd_w 5237 5238 =head3 C<cmd_W> - delete watch expressions (command) 5239 5240 This command accepts either a watch expression to be removed from the list 5241 of watch expressions, or C<*> to delete them all. 5242 5243 If C<*> is specified, we simply empty the watch expression list and the 5244 watch expression value list. We also turn off the bit that says we've got 5245 watch expressions. 5246 5247 If an expression (or partial expression) is specified, we pattern-match 5248 through the expressions and remove the ones that match. We also discard 5249 the corresponding values. If no watch expressions are left, we turn off 5250 the I<watching expressions> bit. 5251 5252 =cut 5253 5254 sub cmd_W { 5255 my $cmd = shift; 5256 my $expr = shift || ''; 5257 5258 # Delete them all. 5259 if ( $expr eq '*' ) { 5260 5261 # Not watching now. 5262 $trace &= ~2; 5263 5264 print $OUT "Deleting all watch expressions ...\n"; 5265 5266 # And all gone. 5267 @to_watch = @old_watch = (); 5268 } 5269 5270 # Delete one of them. 5271 elsif ( $expr =~ /^(\S.*)/ ) { 5272 5273 # Where we are in the list. 5274 my $i_cnt = 0; 5275 5276 # For each expression ... 5277 foreach (@to_watch) { 5278 my $val = $to_watch[$i_cnt]; 5279 5280 # Does this one match the command argument? 5281 if ( $val eq $expr ) { # =~ m/^\Q$i$/) { 5282 # Yes. Turn it off, and its value too. 5283 splice( @to_watch, $i_cnt, 1 ); 5284 splice( @old_watch, $i_cnt, 1 ); 5285 } 5286 $i_cnt++; 5287 } ## end foreach (@to_watch) 5288 5289 # We don't bother to turn watching off because 5290 # a) we don't want to stop calling watchfunction() it it exists 5291 # b) foreach over a null list doesn't do anything anyway 5292 5293 } ## end elsif ($expr =~ /^(\S.*)/) 5294 5295 # No command arguments entered. 5296 else { 5297 print $OUT 5298 "Deleting a watch-expression requires an expression, or '*' for all\n" 5299 ; # hint 5300 } 5301 } ## end sub cmd_W 5302 5303 ### END of the API section 5304 5305 =head1 SUPPORT ROUTINES 5306 5307 These are general support routines that are used in a number of places 5308 throughout the debugger. 5309 5310 =head2 save 5311 5312 save() saves the user's versions of globals that would mess us up in C<@saved>, 5313 and installs the versions we like better. 5314 5315 =cut 5316 5317 sub save { 5318 5319 # Save eval failure, command failure, extended OS error, output field 5320 # separator, input record separator, output record separator and 5321 # the warning setting. 5322 @saved = ( $@, $!, $^E, $,, $/, $\, $^W ); 5323 5324 $, = ""; # output field separator is null string 5325 $/ = "\n"; # input record separator is newline 5326 $\ = ""; # output record separator is null string 5327 $^W = 0; # warnings are off 5328 } ## end sub save 5329 5330 =head2 C<print_lineinfo> - show where we are now 5331 5332 print_lineinfo prints whatever it is that it is handed; it prints it to the 5333 C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows 5334 us to feed line information to a slave editor without messing up the 5335 debugger output. 5336 5337 =cut 5338 5339 sub print_lineinfo { 5340 5341 # Make the terminal sensible if we're not the primary debugger. 5342 resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$; 5343 local $\ = ''; 5344 local $, = ''; 5345 print $LINEINFO @_; 5346 } ## end sub print_lineinfo 5347 5348 =head2 C<postponed_sub> 5349 5350 Handles setting postponed breakpoints in subroutines once they're compiled. 5351 For breakpoints, we use C<DB::find_sub> to locate the source file and line 5352 range for the subroutine, then mark the file as having a breakpoint, 5353 temporarily switch the C<*dbline> glob over to the source file, and then 5354 search the given range of lines to find a breakable line. If we find one, 5355 we set the breakpoint on it, deleting the breakpoint from C<%postponed>. 5356 5357 =cut 5358 5359 # The following takes its argument via $evalarg to preserve current @_ 5360 5361 sub postponed_sub { 5362 5363 # Get the subroutine name. 5364 my $subname = shift; 5365 5366 # If this is a 'break +<n> if <condition>' ... 5367 if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) { 5368 5369 # If there's no offset, use '+0'. 5370 my $offset = $1 || 0; 5371 5372 # find_sub's value is 'fullpath-filename:start-stop'. It's 5373 # possible that the filename might have colons in it too. 5374 my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ ); 5375 if ($i) { 5376 5377 # We got the start line. Add the offset '+<n>' from 5378 # $postponed{subname}. 5379 $i += $offset; 5380 5381 # Switch to the file this sub is in, temporarily. 5382 local *dbline = $main::{ '_<' . $file }; 5383 5384 # No warnings, please. 5385 local $^W = 0; # != 0 is magical below 5386 5387 # This file's got a breakpoint in it. 5388 $had_breakpoints{$file} |= 1; 5389 5390 # Last line in file. 5391 my $max = $#dbline; 5392 5393 # Search forward until we hit a breakable line or get to 5394 # the end of the file. 5395 ++$i until $dbline[$i] != 0 or $i >= $max; 5396 5397 # Copy the breakpoint in and delete it from %postponed. 5398 $dbline{$i} = delete $postponed{$subname}; 5399 } ## end if ($i) 5400 5401 # find_sub didn't find the sub. 5402 else { 5403 local $\ = ''; 5404 print $OUT "Subroutine $subname not found.\n"; 5405 } 5406 return; 5407 } ## end if ($postponed{$subname... 5408 elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 } 5409 5410 #print $OUT "In postponed_sub for `$subname'.\n"; 5411 } ## end sub postponed_sub 5412 5413 =head2 C<postponed> 5414 5415 Called after each required file is compiled, but before it is executed; 5416 also called if the name of a just-compiled subroutine is a key of 5417 C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>, 5418 etc.) into the just-compiled code. 5419 5420 If this is a C<require>'d file, the incoming parameter is the glob 5421 C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file. 5422 5423 If it's a subroutine, the incoming parameter is the subroutine name. 5424 5425 =cut 5426 5427 sub postponed { 5428 5429 # If there's a break, process it. 5430 if ($ImmediateStop) { 5431 5432 # Right, we've stopped. Turn it off. 5433 $ImmediateStop = 0; 5434 5435 # Enter the command loop when DB::DB gets called. 5436 $signal = 1; 5437 } 5438 5439 # If this is a subroutine, let postponed_sub() deal with it. 5440 return &postponed_sub unless ref \$_[0] eq 'GLOB'; 5441 5442 # Not a subroutine. Deal with the file. 5443 local *dbline = shift; 5444 my $filename = $dbline; 5445 $filename =~ s/^_<//; 5446 local $\ = ''; 5447 $signal = 1, print $OUT "'$filename' loaded...\n" 5448 if $break_on_load{$filename}; 5449 print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame; 5450 5451 # Do we have any breakpoints to put in this file? 5452 return unless $postponed_file{$filename}; 5453 5454 # Yes. Mark this file as having breakpoints. 5455 $had_breakpoints{$filename} |= 1; 5456 5457 # "Cannot be done: unsufficient magic" - we can't just put the 5458 # breakpoints saved in %postponed_file into %dbline by assigning 5459 # the whole hash; we have to do it one item at a time for the 5460 # breakpoints to be set properly. 5461 #%dbline = %{$postponed_file{$filename}}; 5462 5463 # Set the breakpoints, one at a time. 5464 my $key; 5465 5466 for $key ( keys %{ $postponed_file{$filename} } ) { 5467 5468 # Stash the saved breakpoint into the current file's magic line array. 5469 $dbline{$key} = ${ $postponed_file{$filename} }{$key}; 5470 } 5471 5472 # This file's been compiled; discard the stored breakpoints. 5473 delete $postponed_file{$filename}; 5474 5475 } ## end sub postponed 5476 5477 =head2 C<dumpit> 5478 5479 C<dumpit> is the debugger's wrapper around dumpvar.pl. 5480 5481 It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and 5482 a reference to a variable (the thing to be dumped) as its input. 5483 5484 The incoming filehandle is selected for output (C<dumpvar.pl> is printing to 5485 the currently-selected filehandle, thank you very much). The current 5486 values of the package globals C<$single> and C<$trace> are backed up in 5487 lexicals, and they are turned off (this keeps the debugger from trying 5488 to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to 5489 preserve its current value and it is set to zero to prevent entry/exit 5490 messages from printing, and C<$doret> is localized as well and set to -2 to 5491 prevent return values from being shown. 5492 5493 C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and 5494 tries to load it (note: if you have a C<dumpvar.pl> ahead of the 5495 installed version in C<@INC>, yours will be used instead. Possible security 5496 problem?). 5497 5498 It then checks to see if the subroutine C<main::dumpValue> is now defined 5499 (it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()> 5500 localizes the globals necessary for things to be sane when C<main::dumpValue()> 5501 is called, and picks up the variable to be dumped from the parameter list. 5502 5503 It checks the package global C<%options> to see if there's a C<dumpDepth> 5504 specified. If not, -1 is assumed; if so, the supplied value gets passed on to 5505 C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a 5506 structure: -1 means dump everything. 5507 5508 C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a 5509 warning. 5510 5511 In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored 5512 and we then return to the caller. 5513 5514 =cut 5515 5516 sub dumpit { 5517 5518 # Save the current output filehandle and switch to the one 5519 # passed in as the first parameter. 5520 local ($savout) = select(shift); 5521 5522 # Save current settings of $single and $trace, and then turn them off. 5523 my $osingle = $single; 5524 my $otrace = $trace; 5525 $single = $trace = 0; 5526 5527 # XXX Okay, what do $frame and $doret do, again? 5528 local $frame = 0; 5529 local $doret = -2; 5530 5531 # Load dumpvar.pl unless we've already got the sub we need from it. 5532 unless ( defined &main::dumpValue ) { 5533 do 'dumpvar.pl' or die $@; 5534 } 5535 5536 # If the load succeeded (or we already had dumpvalue()), go ahead 5537 # and dump things. 5538 if ( defined &main::dumpValue ) { 5539 local $\ = ''; 5540 local $, = ''; 5541 local $" = ' '; 5542 my $v = shift; 5543 my $maxdepth = shift || $option{dumpDepth}; 5544 $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth 5545 &main::dumpValue( $v, $maxdepth ); 5546 } ## end if (defined &main::dumpValue) 5547 5548 # Oops, couldn't load dumpvar.pl. 5549 else { 5550 local $\ = ''; 5551 print $OUT "dumpvar.pl not available.\n"; 5552 } 5553 5554 # Reset $single and $trace to their old values. 5555 $single = $osingle; 5556 $trace = $otrace; 5557 5558 # Restore the old filehandle. 5559 select($savout); 5560 } ## end sub dumpit 5561 5562 =head2 C<print_trace> 5563 5564 C<print_trace>'s job is to print a stack trace. It does this via the 5565 C<dump_trace> routine, which actually does all the ferreting-out of the 5566 stack trace data. C<print_trace> takes care of formatting it nicely and 5567 printing it to the proper filehandle. 5568 5569 Parameters: 5570 5571 =over 4 5572 5573 =item * 5574 5575 The filehandle to print to. 5576 5577 =item * 5578 5579 How many frames to skip before starting trace. 5580 5581 =item * 5582 5583 How many frames to print. 5584 5585 =item * 5586 5587 A flag: if true, print a I<short> trace without filenames, line numbers, or arguments 5588 5589 =back 5590 5591 The original comment below seems to be noting that the traceback may not be 5592 correct if this routine is called in a tied method. 5593 5594 =cut 5595 5596 # Tied method do not create a context, so may get wrong message: 5597 5598 sub print_trace { 5599 local $\ = ''; 5600 my $fh = shift; 5601 5602 # If this is going to a slave editor, but we're not the primary 5603 # debugger, reset it first. 5604 resetterm(1) 5605 if $fh eq $LINEINFO # slave editor 5606 and $LINEINFO eq $OUT # normal output 5607 and $term_pid != $$; # not the primary 5608 5609 # Collect the actual trace information to be formatted. 5610 # This is an array of hashes of subroutine call info. 5611 my @sub = dump_trace( $_[0] + 1, $_[1] ); 5612 5613 # Grab the "short report" flag from @_. 5614 my $short = $_[2]; # Print short report, next one for sub name 5615 5616 # Run through the traceback info, format it, and print it. 5617 my $s; 5618 for ( $i = 0 ; $i <= $#sub ; $i++ ) { 5619 5620 # Drop out if the user has lost interest and hit control-C. 5621 last if $signal; 5622 5623 # Set the separator so arrys print nice. 5624 local $" = ', '; 5625 5626 # Grab and stringify the arguments if they are there. 5627 my $args = 5628 defined $sub[$i]{args} 5629 ? "(@{ $sub[$i]{args} })" 5630 : ''; 5631 5632 # Shorten them up if $maxtrace says they're too long. 5633 $args = ( substr $args, 0, $maxtrace - 3 ) . '...' 5634 if length $args > $maxtrace; 5635 5636 # Get the file name. 5637 my $file = $sub[$i]{file}; 5638 5639 # Put in a filename header if short is off. 5640 $file = $file eq '-e' ? $file : "file `$file'" unless $short; 5641 5642 # Get the actual sub's name, and shorten to $maxtrace's requirement. 5643 $s = $sub[$i]{sub}; 5644 $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace; 5645 5646 # Short report uses trimmed file and sub names. 5647 if ($short) { 5648 my $sub = @_ >= 4 ? $_[3] : $s; 5649 print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n"; 5650 } ## end if ($short) 5651 5652 # Non-short report includes full names. 5653 else { 5654 print $fh "$sub[$i]{context} = $s$args" 5655 . " called from $file" 5656 . " line $sub[$i]{line}\n"; 5657 } 5658 } ## end for ($i = 0 ; $i <= $#sub... 5659 } ## end sub print_trace 5660 5661 =head2 dump_trace(skip[,count]) 5662 5663 Actually collect the traceback information available via C<caller()>. It does 5664 some filtering and cleanup of the data, but mostly it just collects it to 5665 make C<print_trace()>'s job easier. 5666 5667 C<skip> defines the number of stack frames to be skipped, working backwards 5668 from the most current. C<count> determines the total number of frames to 5669 be returned; all of them (well, the first 10^9) are returned if C<count> 5670 is omitted. 5671 5672 This routine returns a list of hashes, from most-recent to least-recent 5673 stack frame. Each has the following keys and values: 5674 5675 =over 4 5676 5677 =item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array) 5678 5679 =item * C<sub> - subroutine name, or C<eval> information 5680 5681 =item * C<args> - undef, or a reference to an array of arguments 5682 5683 =item * C<file> - the file in which this item was defined (if any) 5684 5685 =item * C<line> - the line on which it was defined 5686 5687 =back 5688 5689 =cut 5690 5691 sub dump_trace { 5692 5693 # How many levels to skip. 5694 my $skip = shift; 5695 5696 # How many levels to show. (1e9 is a cheap way of saying "all of them"; 5697 # it's unlikely that we'll have more than a billion stack frames. If you 5698 # do, you've got an awfully big machine...) 5699 my $count = shift || 1e9; 5700 5701 # We increment skip because caller(1) is the first level *back* from 5702 # the current one. Add $skip to the count of frames so we have a 5703 # simple stop criterion, counting from $skip to $count+$skip. 5704 $skip++; 5705 $count += $skip; 5706 5707 # These variables are used to capture output from caller(); 5708 my ( $p, $file, $line, $sub, $h, $context ); 5709 5710 my ( $e, $r, @a, @sub, $args ); 5711 5712 # XXX Okay... why'd we do that? 5713 my $nothard = not $frame & 8; 5714 local $frame = 0; 5715 5716 # Do not want to trace this. 5717 my $otrace = $trace; 5718 $trace = 0; 5719 5720 # Start out at the skip count. 5721 # If we haven't reached the number of frames requested, and caller() is 5722 # still returning something, stay in the loop. (If we pass the requested 5723 # number of stack frames, or we run out - caller() returns nothing - we 5724 # quit. 5725 # Up the stack frame index to go back one more level each time. 5726 for ( 5727 $i = $skip ; 5728 $i < $count 5729 and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ; 5730 $i++ 5731 ) 5732 { 5733 5734 # Go through the arguments and save them for later. 5735 @a = (); 5736 for $arg (@args) { 5737 my $type; 5738 if ( not defined $arg ) { # undefined parameter 5739 push @a, "undef"; 5740 } 5741 5742 elsif ( $nothard and tied $arg ) { # tied parameter 5743 push @a, "tied"; 5744 } 5745 elsif ( $nothard and $type = ref $arg ) { # reference 5746 push @a, "ref($type)"; 5747 } 5748 else { # can be stringified 5749 local $_ = 5750 "$arg"; # Safe to stringify now - should not call f(). 5751 5752 # Backslash any single-quotes or backslashes. 5753 s/([\'\\])/\\$1/g; 5754 5755 # Single-quote it unless it's a number or a colon-separated 5756 # name. 5757 s/(.*)/'$1'/s 5758 unless /^(?: -?[\d.]+ | \*[\w:]* )$/x; 5759 5760 # Turn high-bit characters into meta-whatever. 5761 s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg; 5762 5763 # Turn control characters into ^-whatever. 5764 s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg; 5765 5766 push( @a, $_ ); 5767 } ## end else [ if (not defined $arg) 5768 } ## end for $arg (@args) 5769 5770 # If context is true, this is array (@)context. 5771 # If context is false, this is scalar ($) context. 5772 # If neither, context isn't defined. (This is apparently a 'can't 5773 # happen' trap.) 5774 $context = $context ? '@' : ( defined $context ? "\$" : '.' ); 5775 5776 # if the sub has args ($h true), make an anonymous array of the 5777 # dumped args. 5778 $args = $h ? [@a] : undef; 5779 5780 # remove trailing newline-whitespace-semicolon-end of line sequence 5781 # from the eval text, if any. 5782 $e =~ s/\n\s*\;\s*\Z// if $e; 5783 5784 # Escape backslashed single-quotes again if necessary. 5785 $e =~ s/([\\\'])/\\$1/g if $e; 5786 5787 # if the require flag is true, the eval text is from a require. 5788 if ($r) { 5789 $sub = "require '$e'"; 5790 } 5791 5792 # if it's false, the eval text is really from an eval. 5793 elsif ( defined $r ) { 5794 $sub = "eval '$e'"; 5795 } 5796 5797 # If the sub is '(eval)', this is a block eval, meaning we don't 5798 # know what the eval'ed text actually was. 5799 elsif ( $sub eq '(eval)' ) { 5800 $sub = "eval {...}"; 5801 } 5802 5803 # Stick the collected information into @sub as an anonymous hash. 5804 push( 5805 @sub, 5806 { 5807 context => $context, 5808 sub => $sub, 5809 args => $args, 5810 file => $file, 5811 line => $line 5812 } 5813 ); 5814 5815 # Stop processing frames if the user hit control-C. 5816 last if $signal; 5817 } ## end for ($i = $skip ; $i < ... 5818 5819 # Restore the trace value again. 5820 $trace = $otrace; 5821 @sub; 5822 } ## end sub dump_trace 5823 5824 =head2 C<action()> 5825 5826 C<action()> takes input provided as the argument to an add-action command, 5827 either pre- or post-, and makes sure it's a complete command. It doesn't do 5828 any fancy parsing; it just keeps reading input until it gets a string 5829 without a trailing backslash. 5830 5831 =cut 5832 5833 sub action { 5834 my $action = shift; 5835 5836 while ( $action =~ s/\\$// ) { 5837 5838 # We have a backslash on the end. Read more. 5839 $action .= &gets; 5840 } ## end while ($action =~ s/\\$//) 5841 5842 # Return the assembled action. 5843 $action; 5844 } ## end sub action 5845 5846 =head2 unbalanced 5847 5848 This routine mostly just packages up a regular expression to be used 5849 to check that the thing it's being matched against has properly-matched 5850 curly braces. 5851 5852 Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which 5853 speeds things up by only creating the qr//'ed expression once; if it's 5854 already defined, we don't try to define it again. A speed hack. 5855 5856 =cut 5857 5858 sub unbalanced { 5859 5860 # I hate using globals! 5861 $balanced_brace_re ||= qr{ 5862 ^ \{ 5863 (?: 5864 (?> [^{}] + ) # Non-parens without backtracking 5865 | 5866 (??{ $balanced_brace_re }) # Group with matching parens 5867 ) * 5868 \} $ 5869 }x; 5870 return $_[0] !~ m/$balanced_brace_re/; 5871 } ## end sub unbalanced 5872 5873 =head2 C<gets()> 5874 5875 C<gets()> is a primitive (very primitive) routine to read continuations. 5876 It was devised for reading continuations for actions. 5877 it just reads more input with C<readline()> and returns it. 5878 5879 =cut 5880 5881 sub gets { 5882 &readline("cont: "); 5883 } 5884 5885 =head2 C<DB::system()> - handle calls to<system()> without messing up the debugger 5886 5887 The C<system()> function assumes that it can just go ahead and use STDIN and 5888 STDOUT, but under the debugger, we want it to use the debugger's input and 5889 outout filehandles. 5890 5891 C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes 5892 the debugger's IN and OUT filehandles for them. It does the C<system()> call, 5893 and then puts everything back again. 5894 5895 =cut 5896 5897 sub system { 5898 5899 # We save, change, then restore STDIN and STDOUT to avoid fork() since 5900 # some non-Unix systems can do system() but have problems with fork(). 5901 open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN"); 5902 open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT"); 5903 open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN"); 5904 open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT"); 5905 5906 # XXX: using csh or tcsh destroys sigint retvals! 5907 system(@_); 5908 open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN"); 5909 open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT"); 5910 close(SAVEIN); 5911 close(SAVEOUT); 5912 5913 # most of the $? crud was coping with broken cshisms 5914 if ( $? >> 8 ) { 5915 &warn( "(Command exited ", ( $? >> 8 ), ")\n" ); 5916 } 5917 elsif ($?) { 5918 &warn( 5919 "(Command died of SIG#", 5920 ( $? & 127 ), 5921 ( ( $? & 128 ) ? " -- core dumped" : "" ), 5922 ")", "\n" 5923 ); 5924 } ## end elsif ($?) 5925 5926 return $?; 5927 5928 } ## end sub system 5929 5930 =head1 TTY MANAGEMENT 5931 5932 The subs here do some of the terminal management for multiple debuggers. 5933 5934 =head2 setterm 5935 5936 Top-level function called when we want to set up a new terminal for use 5937 by the debugger. 5938 5939 If the C<noTTY> debugger option was set, we'll either use the terminal 5940 supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous> 5941 to find one. If we're a forked debugger, we call C<resetterm> to try to 5942 get a whole new terminal if we can. 5943 5944 In either case, we set up the terminal next. If the C<ReadLine> option was 5945 true, we'll get a C<Term::ReadLine> object for the current terminal and save 5946 the appropriate attributes. We then 5947 5948 =cut 5949 5950 sub setterm { 5951 5952 # Load Term::Readline, but quietly; don't debug it and don't trace it. 5953 local $frame = 0; 5954 local $doret = -2; 5955 eval { require Term::ReadLine } or die $@; 5956 5957 # If noTTY is set, but we have a TTY name, go ahead and hook up to it. 5958 if ($notty) { 5959 if ($tty) { 5960 my ( $i, $o ) = split $tty, /,/; 5961 $o = $i unless defined $o; 5962 open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!"; 5963 open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!"; 5964 $IN = \*IN; 5965 $OUT = \*OUT; 5966 my $sel = select($OUT); 5967 $| = 1; 5968 select($sel); 5969 } ## end if ($tty) 5970 5971 # We don't have a TTY - try to find one via Term::Rendezvous. 5972 else { 5973 eval "require Term::Rendezvous;" or die; 5974 5975 # See if we have anything to pass to Term::Rendezvous. 5976 # Use $HOME/.perldbtty$$ if not. 5977 my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$"; 5978 5979 # Rendezvous and get the filehandles. 5980 my $term_rv = new Term::Rendezvous $rv; 5981 $IN = $term_rv->IN; 5982 $OUT = $term_rv->OUT; 5983 } ## end else [ if ($tty) 5984 } ## end if ($notty) 5985 5986 # We're a daughter debugger. Try to fork off another TTY. 5987 if ( $term_pid eq '-1' ) { # In a TTY with another debugger 5988 resetterm(2); 5989 } 5990 5991 # If we shouldn't use Term::ReadLine, don't. 5992 if ( !$rl ) { 5993 $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT; 5994 } 5995 5996 # We're using Term::ReadLine. Get all the attributes for this terminal. 5997 else { 5998 $term = new Term::ReadLine 'perldb', $IN, $OUT; 5999 6000 $rl_attribs = $term->Attribs; 6001 $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}' 6002 if defined $rl_attribs->{basic_word_break_characters} 6003 and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1; 6004 $rl_attribs->{special_prefixes} = '$@&%'; 6005 $rl_attribs->{completer_word_break_characters} .= '$@&%'; 6006 $rl_attribs->{completion_function} = \&db_complete; 6007 } ## end else [ if (!$rl) 6008 6009 # Set up the LINEINFO filehandle. 6010 $LINEINFO = $OUT unless defined $LINEINFO; 6011 $lineinfo = $console unless defined $lineinfo; 6012 6013 $term->MinLine(2); 6014 6015 &load_hist(); 6016 6017 if ( $term->Features->{setHistory} and "@hist" ne "?" ) { 6018 $term->SetHistory(@hist); 6019 } 6020 6021 # XXX Ornaments are turned on unconditionally, which is not 6022 # always a good thing. 6023 ornaments($ornaments) if defined $ornaments; 6024 $term_pid = $$; 6025 } ## end sub setterm 6026 6027 sub load_hist { 6028 $histfile //= option_val("HistFile", undef); 6029 return unless defined $histfile; 6030 open my $fh, "<", $histfile or return; 6031 local $/ = "\n"; 6032 @hist = (); 6033 while (<$fh>) { 6034 chomp; 6035 push @hist, $_; 6036 } 6037 close $fh; 6038 } 6039 6040 sub save_hist { 6041 return unless defined $histfile; 6042 eval { require File::Path } or return; 6043 eval { require File::Basename } or return; 6044 File::Path::mkpath(File::Basename::dirname($histfile)); 6045 open my $fh, ">", $histfile or die "Could not open '$histfile': $!"; 6046 $histsize //= option_val("HistSize",100); 6047 my @copy = grep { $_ ne '?' } @hist; 6048 my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0; 6049 for ($start .. $#copy) { 6050 print $fh "$copy[$_]\n"; 6051 } 6052 close $fh or die "Could not write '$histfile': $!"; 6053 } 6054 6055 =head1 GET_FORK_TTY EXAMPLE FUNCTIONS 6056 6057 When the process being debugged forks, or the process invokes a command 6058 via C<system()> which starts a new debugger, we need to be able to get a new 6059 C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes 6060 fight over the terminal, and you can never quite be sure who's going to get the 6061 input you're typing. 6062 6063 C<get_fork_TTY> is a glob-aliased function which calls the real function that 6064 is tasked with doing all the necessary operating system mojo to get a new 6065 TTY (and probably another window) and to direct the new debugger to read and 6066 write there. 6067 6068 The debugger provides C<get_fork_TTY> functions which work for X Windows, 6069 OS/2, and Mac OS X. Other systems are not supported. You are encouraged 6070 to write C<get_fork_TTY> functions which work for I<your> platform 6071 and contribute them. 6072 6073 =head3 C<xterm_get_fork_TTY> 6074 6075 This function provides the C<get_fork_TTY> function for X windows. If a 6076 program running under the debugger forks, a new <xterm> window is opened and 6077 the subsidiary debugger is directed there. 6078 6079 The C<open()> call is of particular note here. We have the new C<xterm> 6080 we're spawning route file number 3 to STDOUT, and then execute the C<tty> 6081 command (which prints the device name of the TTY we'll want to use for input 6082 and output to STDOUT, then C<sleep> for a very long time, routing this output 6083 to file number 3. This way we can simply read from the <XT> filehandle (which 6084 is STDOUT from the I<commands> we ran) to get the TTY we want to use. 6085 6086 Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are 6087 properly set up. 6088 6089 =cut 6090 6091 sub xterm_get_fork_TTY { 6092 ( my $name = $0 ) =~ s,^.*[/\\],,s; 6093 open XT, 6094 qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\ 6095 sleep 10000000' |]; 6096 6097 # Get the output from 'tty' and clean it up a little. 6098 my $tty = <XT>; 6099 chomp $tty; 6100 6101 $pidprompt = ''; # Shown anyway in titlebar 6102 6103 # There's our new TTY. 6104 return $tty; 6105 } ## end sub xterm_get_fork_TTY 6106 6107 =head3 C<os2_get_fork_TTY> 6108 6109 XXX It behooves an OS/2 expert to write the necessary documentation for this! 6110 6111 =cut 6112 6113 # This example function resets $IN, $OUT itself 6114 my $c_pipe = 0; 6115 sub os2_get_fork_TTY { # A simplification of the following (and works without): 6116 local $\ = ''; 6117 ( my $name = $0 ) =~ s,^.*[/\\],,s; 6118 my %opt = ( title => "Daughter Perl debugger $pids $name", 6119 ($rl ? (read_by_key => 1) : ()) ); 6120 require OS2::Process; 6121 my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) } 6122 or return; 6123 $pidprompt = ''; # Shown anyway in titlebar 6124 reset_IN_OUT($in, $out); 6125 $tty = '*reset*'; 6126 return ''; # Indicate that reset_IN_OUT is called 6127 } ## end sub os2_get_fork_TTY 6128 6129 =head3 C<macosx_get_fork_TTY> 6130 6131 The Mac OS X version uses AppleScript to tell Terminal.app to create 6132 a new window. 6133 6134 =cut 6135 6136 # Notes about Terminal.app's AppleScript support, 6137 # (aka things that might break in future OS versions). 6138 # 6139 # The "do script" command doesn't return a reference to the new window 6140 # it creates, but since it appears frontmost and windows are enumerated 6141 # front to back, we can use "first window" === "window 1". 6142 # 6143 # Since "do script" is implemented by supplying the argument (plus a 6144 # return character) as terminal input, there's a potential race condition 6145 # where the debugger could beat the shell to reading the command. 6146 # To prevent this, we wait for the screen to clear before proceeding. 6147 # 6148 # 10.3 and 10.4: 6149 # There's no direct accessor for the tty device name, so we fiddle 6150 # with the window title options until it says what we want. 6151 # 6152 # 10.5: 6153 # There _is_ a direct accessor for the tty device name, _and_ there's 6154 # a new possible component of the window title (the name of the settings 6155 # set). A separate version is needed. 6156 6157 my @script_versions= 6158 6159 ([237, <<'__LEOPARD__'], 6160 tell application "Terminal" 6161 do script "clear;exec sleep 100000" 6162 tell first tab of first window 6163 copy tty to thetty 6164 set custom title to "forked perl debugger" 6165 set title displays custom title to true 6166 repeat while (length of first paragraph of (get contents)) > 0 6167 delay 0.1 6168 end repeat 6169 end tell 6170 end tell 6171 thetty 6172 __LEOPARD__ 6173 6174 [100, <<'__JAGUAR_TIGER__'], 6175 tell application "Terminal" 6176 do script "clear;exec sleep 100000" 6177 tell first window 6178 set title displays shell path to false 6179 set title displays window size to false 6180 set title displays file name to false 6181 set title displays device name to true 6182 set title displays custom title to true 6183 set custom title to "" 6184 copy "/dev/" & name to thetty 6185 set custom title to "forked perl debugger" 6186 repeat while (length of first paragraph of (get contents)) > 0 6187 delay 0.1 6188 end repeat 6189 end tell 6190 end tell 6191 thetty 6192 __JAGUAR_TIGER__ 6193 6194 ); 6195 6196 sub macosx_get_fork_TTY 6197 { 6198 my($version,$script,$pipe,$tty); 6199 6200 return unless $version=$ENV{TERM_PROGRAM_VERSION}; 6201 foreach my $entry (@script_versions) { 6202 if ($version>=$entry->[0]) { 6203 $script=$entry->[1]; 6204 last; 6205 } 6206 } 6207 return unless defined($script); 6208 return unless open($pipe,'-|','/usr/bin/osascript','-e',$script); 6209 $tty=readline($pipe); 6210 close($pipe); 6211 return unless defined($tty) && $tty =~ m(^/dev/); 6212 chomp $tty; 6213 return $tty; 6214 } 6215 6216 =head2 C<create_IN_OUT($flags)> 6217 6218 Create a new pair of filehandles, pointing to a new TTY. If impossible, 6219 try to diagnose why. 6220 6221 Flags are: 6222 6223 =over 4 6224 6225 =item * 1 - Don't know how to create a new TTY. 6226 6227 =item * 2 - Debugger has forked, but we can't get a new TTY. 6228 6229 =item * 4 - standard debugger startup is happening. 6230 6231 =back 6232 6233 =cut 6234 6235 sub create_IN_OUT { # Create a window with IN/OUT handles redirected there 6236 6237 # If we know how to get a new TTY, do it! $in will have 6238 # the TTY name if get_fork_TTY works. 6239 my $in = &get_fork_TTY if defined &get_fork_TTY; 6240 6241 # It used to be that 6242 $in = $fork_TTY if defined $fork_TTY; # Backward compatibility 6243 6244 if ( not defined $in ) { 6245 my $why = shift; 6246 6247 # We don't know how. 6248 print_help(<<EOP) if $why == 1; 6249 I<#########> Forked, but do not know how to create a new B<TTY>. I<#########> 6250 EOP 6251 6252 # Forked debugger. 6253 print_help(<<EOP) if $why == 2; 6254 I<#########> Daughter session, do not know how to change a B<TTY>. I<#########> 6255 This may be an asynchronous session, so the parent debugger may be active. 6256 EOP 6257 6258 # Note that both debuggers are fighting over the same input. 6259 print_help(<<EOP) if $why != 4; 6260 Since two debuggers fight for the same TTY, input is severely entangled. 6261 6262 EOP 6263 print_help(<<EOP); 6264 I know how to switch the output to a different window in xterms, OS/2 6265 consoles, and Mac OS X Terminal.app only. For a manual switch, put the name 6266 of the created I<TTY> in B<\$DB::fork_TTY>, or define a function 6267 B<DB::get_fork_TTY()> returning this. 6268 6269 On I<UNIX>-like systems one can get the name of a I<TTY> for the given window 6270 by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>. 6271 6272 EOP 6273 } ## end if (not defined $in) 6274 elsif ( $in ne '' ) { 6275 TTY($in); 6276 } 6277 else { 6278 $console = ''; # Indicate no need to open-from-the-console 6279 } 6280 undef $fork_TTY; 6281 } ## end sub create_IN_OUT 6282 6283 =head2 C<resetterm> 6284 6285 Handles rejiggering the prompt when we've forked off a new debugger. 6286 6287 If the new debugger happened because of a C<system()> that invoked a 6288 program under the debugger, the arrow between the old pid and the new 6289 in the prompt has I<two> dashes instead of one. 6290 6291 We take the current list of pids and add this one to the end. If there 6292 isn't any list yet, we make one up out of the initial pid associated with 6293 the terminal and our new pid, sticking an arrow (either one-dashed or 6294 two dashed) in between them. 6295 6296 If C<CreateTTY> is off, or C<resetterm> was called with no arguments, 6297 we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead 6298 and try to do that. 6299 6300 =cut 6301 6302 sub resetterm { # We forked, so we need a different TTY 6303 6304 # Needs to be passed to create_IN_OUT() as well. 6305 my $in = shift; 6306 6307 # resetterm(2): got in here because of a system() starting a debugger. 6308 # resetterm(1): just forked. 6309 my $systemed = $in > 1 ? '-' : ''; 6310 6311 # If there's already a list of pids, add this to the end. 6312 if ($pids) { 6313 $pids =~ s/\]/$systemed->$$]/; 6314 } 6315 6316 # No pid list. Time to make one. 6317 else { 6318 $pids = "[$term_pid->$$]"; 6319 } 6320 6321 # The prompt we're going to be using for this debugger. 6322 $pidprompt = $pids; 6323 6324 # We now 0wnz this terminal. 6325 $term_pid = $$; 6326 6327 # Just return if we're not supposed to try to create a new TTY. 6328 return unless $CreateTTY & $in; 6329 6330 # Try to create a new IN/OUT pair. 6331 create_IN_OUT($in); 6332 } ## end sub resetterm 6333 6334 =head2 C<readline> 6335 6336 First, we handle stuff in the typeahead buffer. If there is any, we shift off 6337 the next line, print a message saying we got it, add it to the terminal 6338 history (if possible), and return it. 6339 6340 If there's nothing in the typeahead buffer, check the command filehandle stack. 6341 If there are any filehandles there, read from the last one, and return the line 6342 if we got one. If not, we pop the filehandle off and close it, and try the 6343 next one up the stack. 6344 6345 If we've emptied the filehandle stack, we check to see if we've got a socket 6346 open, and we read that and return it if we do. If we don't, we just call the 6347 core C<readline()> and return its value. 6348 6349 =cut 6350 6351 sub readline { 6352 6353 # Localize to prevent it from being smashed in the program being debugged. 6354 local $.; 6355 6356 # Pull a line out of the typeahead if there's stuff there. 6357 if (@typeahead) { 6358 6359 # How many lines left. 6360 my $left = @typeahead; 6361 6362 # Get the next line. 6363 my $got = shift @typeahead; 6364 6365 # Print a message saying we got input from the typeahead. 6366 local $\ = ''; 6367 print $OUT "auto(-$left)", shift, $got, "\n"; 6368 6369 # Add it to the terminal history (if possible). 6370 $term->AddHistory($got) 6371 if length($got) > 1 6372 and defined $term->Features->{addHistory}; 6373 return $got; 6374 } ## end if (@typeahead) 6375 6376 # We really need to read some input. Turn off entry/exit trace and 6377 # return value printing. 6378 local $frame = 0; 6379 local $doret = -2; 6380 6381 # If there are stacked filehandles to read from ... 6382 while (@cmdfhs) { 6383 6384 # Read from the last one in the stack. 6385 my $line = CORE::readline( $cmdfhs[-1] ); 6386 6387 # If we got a line ... 6388 defined $line 6389 ? ( print $OUT ">> $line" and return $line ) # Echo and return 6390 : close pop @cmdfhs; # Pop and close 6391 } ## end while (@cmdfhs) 6392 6393 # Nothing on the filehandle stack. Socket? 6394 if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) { 6395 6396 # Send anyting we have to send. 6397 $OUT->write( join( '', @_ ) ); 6398 6399 # Receive anything there is to receive. 6400 $stuff; 6401 my $stuff = ''; 6402 my $buf; 6403 do { 6404 $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?" 6405 # XXX Don't know. You tell me. 6406 } while length $buf and ($stuff .= $buf) !~ /\n/; 6407 6408 # What we got. 6409 $stuff; 6410 } ## end if (ref $OUT and UNIVERSAL::isa... 6411 6412 # No socket. Just read from the terminal. 6413 else { 6414 $term->readline(@_); 6415 } 6416 } ## end sub readline 6417 6418 =head1 OPTIONS SUPPORT ROUTINES 6419 6420 These routines handle listing and setting option values. 6421 6422 =head2 C<dump_option> - list the current value of an option setting 6423 6424 This routine uses C<option_val> to look up the value for an option. 6425 It cleans up escaped single-quotes and then displays the option and 6426 its value. 6427 6428 =cut 6429 6430 sub dump_option { 6431 my ( $opt, $val ) = @_; 6432 $val = option_val( $opt, 'N/A' ); 6433 $val =~ s/([\\\'])/\\$1/g; 6434 printf $OUT "%20s = '%s'\n", $opt, $val; 6435 } ## end sub dump_option 6436 6437 sub options2remember { 6438 foreach my $k (@RememberOnROptions) { 6439 $option{$k} = option_val( $k, 'N/A' ); 6440 } 6441 return %option; 6442 } 6443 6444 =head2 C<option_val> - find the current value of an option 6445 6446 This can't just be a simple hash lookup because of the indirect way that 6447 the option values are stored. Some are retrieved by calling a subroutine, 6448 some are just variables. 6449 6450 You must supply a default value to be used in case the option isn't set. 6451 6452 =cut 6453 6454 sub option_val { 6455 my ( $opt, $default ) = @_; 6456 my $val; 6457 6458 # Does this option exist, and is it a variable? 6459 # If so, retrieve the value via the value in %optionVars. 6460 if ( defined $optionVars{$opt} 6461 and defined ${ $optionVars{$opt} } ) 6462 { 6463 $val = ${ $optionVars{$opt} }; 6464 } 6465 6466 # Does this option exist, and it's a subroutine? 6467 # If so, call the subroutine via the ref in %optionAction 6468 # and capture the value. 6469 elsif ( defined $optionAction{$opt} 6470 and defined &{ $optionAction{$opt} } ) 6471 { 6472 $val = &{ $optionAction{$opt} }(); 6473 } 6474 6475 # If there's an action or variable for the supplied option, 6476 # but no value was set, use the default. 6477 elsif (defined $optionAction{$opt} and not defined $option{$opt} 6478 or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } ) 6479 { 6480 $val = $default; 6481 } 6482 6483 # Otherwise, do the simple hash lookup. 6484 else { 6485 $val = $option{$opt}; 6486 } 6487 6488 # If the value isn't defined, use the default. 6489 # Then return whatever the value is. 6490 $val = $default unless defined $val; 6491 $val; 6492 } ## end sub option_val 6493 6494 =head2 C<parse_options> 6495 6496 Handles the parsing and execution of option setting/displaying commands. 6497 6498 An option entered by itself is assumed to be I<set me to 1> (the default value) 6499 if the option is a boolean one. If not, the user is prompted to enter a valid 6500 value or to query the current value (via C<option? >). 6501 6502 If C<option=value> is entered, we try to extract a quoted string from the 6503 value (if it is quoted). If it's not, we just use the whole value as-is. 6504 6505 We load any modules required to service this option, and then we set it: if 6506 it just gets stuck in a variable, we do that; if there's a subroutine to 6507 handle setting the option, we call that. 6508 6509 Finally, if we're running in interactive mode, we display the effect of the 6510 user's command back to the terminal, skipping this if we're setting things 6511 during initialization. 6512 6513 =cut 6514 6515 sub parse_options { 6516 local ($_) = @_; 6517 local $\ = ''; 6518 6519 # These options need a value. Don't allow them to be clobbered by accident. 6520 my %opt_needs_val = map { ( $_ => 1 ) } qw{ 6521 dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize 6522 pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet 6523 }; 6524 6525 while (length) { 6526 my $val_defaulted; 6527 6528 # Clean off excess leading whitespace. 6529 s/^\s+// && next; 6530 6531 # Options are always all word characters, followed by a non-word 6532 # separator. 6533 s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last; 6534 my ( $opt, $sep ) = ( $1, $2 ); 6535 6536 # Make sure that such an option exists. 6537 my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options ) 6538 || grep( /^\Q$opt/i && ( $option = $_ ), @options ); 6539 6540 print( $OUT "Unknown option `$opt'\n" ), next unless $matches; 6541 print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1; 6542 my $val; 6543 6544 # '?' as separator means query, but must have whitespace after it. 6545 if ( "?" eq $sep ) { 6546 print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ), 6547 last 6548 if /^\S/; 6549 6550 #&dump_option($opt); 6551 } ## end if ("?" eq $sep) 6552 6553 # Separator is whitespace (or just a carriage return). 6554 # They're going for a default, which we assume is 1. 6555 elsif ( $sep !~ /\S/ ) { 6556 $val_defaulted = 1; 6557 $val = "1"; # this is an evil default; make 'em set it! 6558 } 6559 6560 # Separator is =. Trying to set a value. 6561 elsif ( $sep eq "=" ) { 6562 6563 # If quoted, extract a quoted string. 6564 if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) { 6565 my $quote = $1; 6566 ( $val = $2 ) =~ s/\\([$quote\\])/$1/g; 6567 } 6568 6569 # Not quoted. Use the whole thing. Warn about 'option='. 6570 else { 6571 s/^(\S*)//; 6572 $val = $1; 6573 print OUT qq(Option better cleared using $opt=""\n) 6574 unless length $val; 6575 } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) 6576 6577 } ## end elsif ($sep eq "=") 6578 6579 # "Quoted" with [], <>, or {}. 6580 else { #{ to "let some poor schmuck bounce on the % key in B<vi>." 6581 my ($end) = 6582 "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #} 6583 s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)// 6584 or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last; 6585 ( $val = $1 ) =~ s/\\([\\$end])/$1/g; 6586 } ## end else [ if ("?" eq $sep) 6587 6588 # Exclude non-booleans from getting set to 1 by default. 6589 if ( $opt_needs_val{$option} && $val_defaulted ) { 6590 my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O'; 6591 print $OUT 6592 "Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n"; 6593 next; 6594 } ## end if ($opt_needs_val{$option... 6595 6596 # Save the option value. 6597 $option{$option} = $val if defined $val; 6598 6599 # Load any module that this option requires. 6600 eval qq{ 6601 local \$frame = 0; 6602 local \$doret = -2; 6603 require '$optionRequire{$option}'; 6604 1; 6605 } || die # XXX: shouldn't happen 6606 if defined $optionRequire{$option} 6607 && defined $val; 6608 6609 # Set it. 6610 # Stick it in the proper variable if it goes in a variable. 6611 ${ $optionVars{$option} } = $val 6612 if defined $optionVars{$option} 6613 && defined $val; 6614 6615 # Call the appropriate sub if it gets set via sub. 6616 &{ $optionAction{$option} }($val) 6617 if defined $optionAction{$option} 6618 && defined &{ $optionAction{$option} } 6619 && defined $val; 6620 6621 # Not initialization - echo the value we set it to. 6622 dump_option($option) unless $OUT eq \*STDERR; 6623 } ## end while (length) 6624 } ## end sub parse_options 6625 6626 =head1 RESTART SUPPORT 6627 6628 These routines are used to store (and restore) lists of items in environment 6629 variables during a restart. 6630 6631 =head2 set_list 6632 6633 Set_list packages up items to be stored in a set of environment variables 6634 (VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing 6635 the values). Values outside the standard ASCII charset are stored by encoding 6636 then as hexadecimal values. 6637 6638 =cut 6639 6640 sub set_list { 6641 my ( $stem, @list ) = @_; 6642 my $val; 6643 6644 # VAR_n: how many we have. Scalar assignment gets the number of items. 6645 $ENV{"${stem}_n"} = @list; 6646 6647 # Grab each item in the list, escape the backslashes, encode the non-ASCII 6648 # as hex, and then save in the appropriate VAR_0, VAR_1, etc. 6649 for $i ( 0 .. $#list ) { 6650 $val = $list[$i]; 6651 $val =~ s/\\/\\\\/g; 6652 $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg; 6653 $ENV{"${stem}_$i"} = $val; 6654 } ## end for $i (0 .. $#list) 6655 } ## end sub set_list 6656 6657 =head2 get_list 6658 6659 Reverse the set_list operation: grab VAR_n to see how many we should be getting 6660 back, and then pull VAR_0, VAR_1. etc. back out. 6661 6662 =cut 6663 6664 sub get_list { 6665 my $stem = shift; 6666 my @list; 6667 my $n = delete $ENV{"${stem}_n"}; 6668 my $val; 6669 for $i ( 0 .. $n - 1 ) { 6670 $val = delete $ENV{"${stem}_$i"}; 6671 $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge; 6672 push @list, $val; 6673