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diff --git a/Master/tlpkg/tlperl/lib/perl5db.pl b/Master/tlpkg/tlperl/lib/perl5db.pl new file mode 100755 index 00000000000..ee1708cdc60 --- /dev/null +++ b/Master/tlpkg/tlperl/lib/perl5db.pl @@ -0,0 +1,9542 @@ + +=head1 NAME + +perl5db.pl - the perl debugger + +=head1 SYNOPSIS + + perl -d your_Perl_script + +=head1 DESCRIPTION + +C<perl5db.pl> is the perl debugger. It is loaded automatically by Perl when +you invoke a script with C<perl -d>. This documentation tries to outline the +structure and services provided by C<perl5db.pl>, and to describe how you +can use them. + +=head1 GENERAL NOTES + +The debugger can look pretty forbidding to many Perl programmers. There are +a number of reasons for this, many stemming out of the debugger's history. + +When the debugger was first written, Perl didn't have a lot of its nicer +features - no references, no lexical variables, no closures, no object-oriented +programming. So a lot of the things one would normally have done using such +features was done using global variables, globs and the C<local()> operator +in creative ways. + +Some of these have survived into the current debugger; a few of the more +interesting and still-useful idioms are noted in this section, along with notes +on the comments themselves. + +=head2 Why not use more lexicals? + +Experienced Perl programmers will note that the debugger code tends to use +mostly package globals rather than lexically-scoped variables. This is done +to allow a significant amount of control of the debugger from outside the +debugger itself. + +Unfortunately, though the variables are accessible, they're not well +documented, so it's generally been a decision that hasn't made a lot of +difference to most users. Where appropriate, comments have been added to +make variables more accessible and usable, with the understanding that these +I<are> debugger internals, and are therefore subject to change. Future +development should probably attempt to replace the globals with a well-defined +API, but for now, the variables are what we've got. + +=head2 Automated variable stacking via C<local()> + +As you may recall from reading C<perlfunc>, the C<local()> operator makes a +temporary copy of a variable in the current scope. When the scope ends, the +old copy is restored. This is often used in the debugger to handle the +automatic stacking of variables during recursive calls: + + sub foo { + local $some_global++; + + # Do some stuff, then ... + return; + } + +What happens is that on entry to the subroutine, C<$some_global> is localized, +then altered. When the subroutine returns, Perl automatically undoes the +localization, restoring the previous value. Voila, automatic stack management. + +The debugger uses this trick a I<lot>. Of particular note is C<DB::eval>, +which lets the debugger get control inside of C<eval>'ed code. The debugger +localizes a saved copy of C<$@> inside the subroutine, which allows it to +keep C<$@> safe until it C<DB::eval> returns, at which point the previous +value of C<$@> is restored. This makes it simple (well, I<simpler>) to keep +track of C<$@> inside C<eval>s which C<eval> other C<eval's>. + +In any case, watch for this pattern. It occurs fairly often. + +=head2 The C<^> trick + +This is used to cleverly reverse the sense of a logical test depending on +the value of an auxiliary variable. For instance, the debugger's C<S> +(search for subroutines by pattern) allows you to negate the pattern +like this: + + # Find all non-'foo' subs: + S !/foo/ + +Boolean algebra states that the truth table for XOR looks like this: + +=over 4 + +=item * 0 ^ 0 = 0 + +(! not present and no match) --> false, don't print + +=item * 0 ^ 1 = 1 + +(! not present and matches) --> true, print + +=item * 1 ^ 0 = 1 + +(! present and no match) --> true, print + +=item * 1 ^ 1 = 0 + +(! present and matches) --> false, don't print + +=back + +As you can see, the first pair applies when C<!> isn't supplied, and +the second pair applies when it is. The XOR simply allows us to +compact a more complicated if-then-elseif-else into a more elegant +(but perhaps overly clever) single test. After all, it needed this +explanation... + +=head2 FLAGS, FLAGS, FLAGS + +There is a certain C programming legacy in the debugger. Some variables, +such as C<$single>, C<$trace>, and C<$frame>, have I<magical> values composed +of 1, 2, 4, etc. (powers of 2) OR'ed together. This allows several pieces +of state to be stored independently in a single scalar. + +A test like + + if ($scalar & 4) ... + +is checking to see if the appropriate bit is on. Since each bit can be +"addressed" independently in this way, C<$scalar> is acting sort of like +an array of bits. Obviously, since the contents of C<$scalar> are just a +bit-pattern, we can save and restore it easily (it will just look like +a number). + +The problem, is of course, that this tends to leave magic numbers scattered +all over your program whenever a bit is set, cleared, or checked. So why do +it? + +=over 4 + +=item * + +First, doing an arithmetical or bitwise operation on a scalar is +just about the fastest thing you can do in Perl: C<use constant> actually +creates a subroutine call, and array and hash lookups are much slower. Is +this over-optimization at the expense of readability? Possibly, but the +debugger accesses these variables a I<lot>. Any rewrite of the code will +probably have to benchmark alternate implementations and see which is the +best balance of readability and speed, and then document how it actually +works. + +=item * + +Second, it's very easy to serialize a scalar number. This is done in +the restart code; the debugger state variables are saved in C<%ENV> and then +restored when the debugger is restarted. Having them be just numbers makes +this trivial. + +=item * + +Third, some of these variables are being shared with the Perl core +smack in the middle of the interpreter's execution loop. It's much faster for +a C program (like the interpreter) to check a bit in a scalar than to access +several different variables (or a Perl array). + +=back + +=head2 What are those C<XXX> comments for? + +Any comment containing C<XXX> means that the comment is either somewhat +speculative - it's not exactly clear what a given variable or chunk of +code is doing, or that it is incomplete - the basics may be clear, but the +subtleties are not completely documented. + +Send in a patch if you can clear up, fill out, or clarify an C<XXX>. + +=head1 DATA STRUCTURES MAINTAINED BY CORE + +There are a number of special data structures provided to the debugger by +the Perl interpreter. + +The array C<@{$main::{'_<'.$filename}}> (aliased locally to C<@dbline> via glob +assignment) contains the text from C<$filename>, with each element +corresponding to a single line of C<$filename>. + +The hash C<%{'_<'.$filename}> (aliased locally to C<%dbline> via glob +assignment) contains breakpoints and actions. The keys are line numbers; +you can set individual values, but not the whole hash. The Perl interpreter +uses this hash to determine where breakpoints have been set. Any true value is +considered to be a breakpoint; C<perl5db.pl> uses C<$break_condition\0$action>. +Values are magical in numeric context: 1 if the line is breakable, 0 if not. + +The scalar C<${"_<$filename"}> simply contains the string C<_<$filename>. +This is also the case for evaluated strings that contain subroutines, or +which are currently being executed. The $filename for C<eval>ed strings looks +like C<(eval 34)> or C<(re_eval 19)>. + +=head1 DEBUGGER STARTUP + +When C<perl5db.pl> starts, it reads an rcfile (C<perl5db.ini> for +non-interactive sessions, C<.perldb> for interactive ones) that can set a number +of options. In addition, this file may define a subroutine C<&afterinit> +that will be executed (in the debugger's context) after the debugger has +initialized itself. + +Next, it checks the C<PERLDB_OPTS> environment variable and treats its +contents as the argument of a C<o> command in the debugger. + +=head2 STARTUP-ONLY OPTIONS + +The following options can only be specified at startup. +To set them in your rcfile, add a call to +C<&parse_options("optionName=new_value")>. + +=over 4 + +=item * TTY + +the TTY to use for debugging i/o. + +=item * noTTY + +if set, goes in NonStop mode. On interrupt, if TTY is not set, +uses the value of noTTY or F<$HOME/.perldbtty$$> to find TTY using +Term::Rendezvous. Current variant is to have the name of TTY in this +file. + +=item * ReadLine + +if false, a dummy ReadLine is used, so you can debug +ReadLine applications. + +=item * NonStop + +if true, no i/o is performed until interrupt. + +=item * LineInfo + +file or pipe to print line number info to. If it is a +pipe, a short "emacs like" message is used. + +=item * RemotePort + +host:port to connect to on remote host for remote debugging. + +=item * HistFile + +file to store session history to. There is no default and so no +history file is written unless this variable is explicitly set. + +=item * HistSize + +number of commands to store to the file specified in C<HistFile>. +Default is 100. + +=back + +=head3 SAMPLE RCFILE + + &parse_options("NonStop=1 LineInfo=db.out"); + sub afterinit { $trace = 1; } + +The script will run without human intervention, putting trace +information into C<db.out>. (If you interrupt it, you had better +reset C<LineInfo> to something I<interactive>!) + +=head1 INTERNALS DESCRIPTION + +=head2 DEBUGGER INTERFACE VARIABLES + +Perl supplies the values for C<%sub>. It effectively inserts +a C<&DB::DB();> in front of each place that can have a +breakpoint. At each subroutine call, it calls C<&DB::sub> with +C<$DB::sub> set to the called subroutine. It also inserts a C<BEGIN +{require 'perl5db.pl'}> before the first line. + +After each C<require>d file is compiled, but before it is executed, a +call to C<&DB::postponed($main::{'_<'.$filename})> is done. C<$filename> +is the expanded name of the C<require>d file (as found via C<%INC>). + +=head3 IMPORTANT INTERNAL VARIABLES + +=head4 C<$CreateTTY> + +Used to control when the debugger will attempt to acquire another TTY to be +used for input. + +=over + +=item * 1 - on C<fork()> + +=item * 2 - debugger is started inside debugger + +=item * 4 - on startup + +=back + +=head4 C<$doret> + +The value -2 indicates that no return value should be printed. +Any other positive value causes C<DB::sub> to print return values. + +=head4 C<$evalarg> + +The item to be eval'ed by C<DB::eval>. Used to prevent messing with the current +contents of C<@_> when C<DB::eval> is called. + +=head4 C<$frame> + +Determines what messages (if any) will get printed when a subroutine (or eval) +is entered or exited. + +=over 4 + +=item * 0 - No enter/exit messages + +=item * 1 - Print I<entering> messages on subroutine entry + +=item * 2 - Adds exit messages on subroutine exit. If no other flag is on, acts like 1+2. + +=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. + +=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. + +=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. + +=back + +To get everything, use C<$frame=30> (or C<o f=30> as a debugger command). +The debugger internally juggles the value of C<$frame> during execution to +protect external modules that the debugger uses from getting traced. + +=head4 C<$level> + +Tracks current debugger nesting level. Used to figure out how many +C<E<lt>E<gt>> pairs to surround the line number with when the debugger +outputs a prompt. Also used to help determine if the program has finished +during command parsing. + +=head4 C<$onetimeDump> + +Controls what (if anything) C<DB::eval()> will print after evaluating an +expression. + +=over 4 + +=item * C<undef> - don't print anything + +=item * C<dump> - use C<dumpvar.pl> to display the value returned + +=item * C<methods> - print the methods callable on the first item returned + +=back + +=head4 C<$onetimeDumpDepth> + +Controls how far down C<dumpvar.pl> will go before printing C<...> while +dumping a structure. Numeric. If C<undef>, print all levels. + +=head4 C<$signal> + +Used to track whether or not an C<INT> signal has been detected. C<DB::DB()>, +which is called before every statement, checks this and puts the user into +command mode if it finds C<$signal> set to a true value. + +=head4 C<$single> + +Controls behavior during single-stepping. Stacked in C<@stack> on entry to +each subroutine; popped again at the end of each subroutine. + +=over 4 + +=item * 0 - run continuously. + +=item * 1 - single-step, go into subs. The C<s> command. + +=item * 2 - single-step, don't go into subs. The C<n> command. + +=item * 4 - print current sub depth (turned on to force this when C<too much +recursion> occurs. + +=back + +=head4 C<$trace> + +Controls the output of trace information. + +=over 4 + +=item * 1 - The C<t> command was entered to turn on tracing (every line executed is printed) + +=item * 2 - watch expressions are active + +=item * 4 - user defined a C<watchfunction()> in C<afterinit()> + +=back + +=head4 C<$slave_editor> + +1 if C<LINEINFO> was directed to a pipe; 0 otherwise. + +=head4 C<@cmdfhs> + +Stack of filehandles that C<DB::readline()> will read commands from. +Manipulated by the debugger's C<source> command and C<DB::readline()> itself. + +=head4 C<@dbline> + +Local alias to the magical line array, C<@{$main::{'_<'.$filename}}> , +supplied by the Perl interpreter to the debugger. Contains the source. + +=head4 C<@old_watch> + +Previous values of watch expressions. First set when the expression is +entered; reset whenever the watch expression changes. + +=head4 C<@saved> + +Saves important globals (C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W>) +so that the debugger can substitute safe values while it's running, and +restore them when it returns control. + +=head4 C<@stack> + +Saves the current value of C<$single> on entry to a subroutine. +Manipulated by the C<c> command to turn off tracing in all subs above the +current one. + +=head4 C<@to_watch> + +The 'watch' expressions: to be evaluated before each line is executed. + +=head4 C<@typeahead> + +The typeahead buffer, used by C<DB::readline>. + +=head4 C<%alias> + +Command aliases. Stored as character strings to be substituted for a command +entered. + +=head4 C<%break_on_load> + +Keys are file names, values are 1 (break when this file is loaded) or undef +(don't break when it is loaded). + +=head4 C<%dbline> + +Keys are line numbers, values are C<condition\0action>. If used in numeric +context, values are 0 if not breakable, 1 if breakable, no matter what is +in the actual hash entry. + +=head4 C<%had_breakpoints> + +Keys are file names; values are bitfields: + +=over 4 + +=item * 1 - file has a breakpoint in it. + +=item * 2 - file has an action in it. + +=back + +A zero or undefined value means this file has neither. + +=head4 C<%option> + +Stores the debugger options. These are character string values. + +=head4 C<%postponed> + +Saves breakpoints for code that hasn't been compiled yet. +Keys are subroutine names, values are: + +=over 4 + +=item * C<compile> - break when this sub is compiled + +=item * C<< break +0 if <condition> >> - break (conditionally) at the start of this routine. The condition will be '1' if no condition was specified. + +=back + +=head4 C<%postponed_file> + +This hash keeps track of breakpoints that need to be set for files that have +not yet been compiled. Keys are filenames; values are references to hashes. +Each of these hashes is keyed by line number, and its values are breakpoint +definitions (C<condition\0action>). + +=head1 DEBUGGER INITIALIZATION + +The debugger's initialization actually jumps all over the place inside this +package. This is because there are several BEGIN blocks (which of course +execute immediately) spread through the code. Why is that? + +The debugger needs to be able to change some things and set some things up +before the debugger code is compiled; most notably, the C<$deep> variable that +C<DB::sub> uses to tell when a program has recursed deeply. In addition, the +debugger has to turn off warnings while the debugger code is compiled, but then +restore them to their original setting before the program being debugged begins +executing. + +The first C<BEGIN> block simply turns off warnings by saving the current +setting of C<$^W> and then setting it to zero. The second one initializes +the debugger variables that are needed before the debugger begins executing. +The third one puts C<$^X> back to its former value. + +We'll detail the second C<BEGIN> block later; just remember that if you need +to initialize something before the debugger starts really executing, that's +where it has to go. + +=cut + +package DB; + +BEGIN {eval 'use IO::Handle'}; # Needed for flush only? breaks under miniperl + +# Debugger for Perl 5.00x; perl5db.pl patch level: +$VERSION = 1.32; + +$header = "perl5db.pl version $VERSION"; + +=head1 DEBUGGER ROUTINES + +=head2 C<DB::eval()> + +This function replaces straight C<eval()> inside the debugger; it simplifies +the process of evaluating code in the user's context. + +The code to be evaluated is passed via the package global variable +C<$DB::evalarg>; this is done to avoid fiddling with the contents of C<@_>. + +Before we do the C<eval()>, we preserve the current settings of C<$trace>, +C<$single>, C<$^D> and C<$usercontext>. The latter contains the +preserved values of C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, C<$\>, C<$^W> and the +user's current package, grabbed when C<DB::DB> got control. This causes the +proper context to be used when the eval is actually done. Afterward, we +restore C<$trace>, C<$single>, and C<$^D>. + +Next we need to handle C<$@> without getting confused. We save C<$@> in a +local lexical, localize C<$saved[0]> (which is where C<save()> will put +C<$@>), and then call C<save()> to capture C<$@>, C<$!>, C<$^E>, C<$,>, +C<$/>, C<$\>, and C<$^W>) and set C<$,>, C<$/>, C<$\>, and C<$^W> to values +considered sane by the debugger. If there was an C<eval()> error, we print +it on the debugger's output. If C<$onetimedump> is defined, we call +C<dumpit> if it's set to 'dump', or C<methods> if it's set to +'methods'. Setting it to something else causes the debugger to do the eval +but not print the result - handy if you want to do something else with it +(the "watch expressions" code does this to get the value of the watch +expression but not show it unless it matters). + +In any case, we then return the list of output from C<eval> to the caller, +and unwinding restores the former version of C<$@> in C<@saved> as well +(the localization of C<$saved[0]> goes away at the end of this scope). + +=head3 Parameters and variables influencing execution of DB::eval() + +C<DB::eval> isn't parameterized in the standard way; this is to keep the +debugger's calls to C<DB::eval()> from mucking with C<@_>, among other things. +The variables listed below influence C<DB::eval()>'s execution directly. + +=over 4 + +=item C<$evalarg> - the thing to actually be eval'ed + +=item C<$trace> - Current state of execution tracing + +=item C<$single> - Current state of single-stepping + +=item C<$onetimeDump> - what is to be displayed after the evaluation + +=item C<$onetimeDumpDepth> - how deep C<dumpit()> should go when dumping results + +=back + +The following variables are altered by C<DB::eval()> during its execution. They +are "stacked" via C<local()>, enabling recursive calls to C<DB::eval()>. + +=over 4 + +=item C<@res> - used to capture output from actual C<eval>. + +=item C<$otrace> - saved value of C<$trace>. + +=item C<$osingle> - saved value of C<$single>. + +=item C<$od> - saved value of C<$^D>. + +=item C<$saved[0]> - saved value of C<$@>. + +=item $\ - for output of C<$@> if there is an evaluation error. + +=back + +=head3 The problem of lexicals + +The context of C<DB::eval()> presents us with some problems. Obviously, +we want to be 'sandboxed' away from the debugger's internals when we do +the eval, but we need some way to control how punctuation variables and +debugger globals are used. + +We can't use local, because the code inside C<DB::eval> can see localized +variables; and we can't use C<my> either for the same reason. The code +in this routine compromises and uses C<my>. + +After this routine is over, we don't have user code executing in the debugger's +context, so we can use C<my> freely. + +=cut + +############################################## Begin lexical danger zone + +# 'my' variables used here could leak into (that is, be visible in) +# the context that the code being evaluated is executing in. This means that +# the code could modify the debugger's variables. +# +# Fiddling with the debugger's context could be Bad. We insulate things as +# much as we can. + +sub eval { + + # 'my' would make it visible from user code + # but so does local! --tchrist + # Remember: this localizes @DB::res, not @main::res. + local @res; + { + + # Try to keep the user code from messing with us. Save these so that + # even if the eval'ed code changes them, we can put them back again. + # Needed because the user could refer directly to the debugger's + # package globals (and any 'my' variables in this containing scope) + # inside the eval(), and we want to try to stay safe. + local $otrace = $trace; + local $osingle = $single; + local $od = $^D; + + # Untaint the incoming eval() argument. + { ($evalarg) = $evalarg =~ /(.*)/s; } + + # $usercontext built in DB::DB near the comment + # "set up the context for DB::eval ..." + # Evaluate and save any results. + @res = eval "$usercontext $evalarg;\n"; # '\n' for nice recursive debug + + # Restore those old values. + $trace = $otrace; + $single = $osingle; + $^D = $od; + } + + # Save the current value of $@, and preserve it in the debugger's copy + # of the saved precious globals. + my $at = $@; + + # Since we're only saving $@, we only have to localize the array element + # that it will be stored in. + local $saved[0]; # Preserve the old value of $@ + eval { &DB::save }; + + # Now see whether we need to report an error back to the user. + if ($at) { + local $\ = ''; + print $OUT $at; + } + + # Display as required by the caller. $onetimeDump and $onetimedumpDepth + # are package globals. + elsif ($onetimeDump) { + if ( $onetimeDump eq 'dump' ) { + local $option{dumpDepth} = $onetimedumpDepth + if defined $onetimedumpDepth; + dumpit( $OUT, \@res ); + } + elsif ( $onetimeDump eq 'methods' ) { + methods( $res[0] ); + } + } ## end elsif ($onetimeDump) + @res; +} ## end sub eval + +############################################## End lexical danger zone + +# After this point it is safe to introduce lexicals. +# The code being debugged will be executing in its own context, and +# can't see the inside of the debugger. +# +# However, one should not overdo it: leave as much control from outside as +# possible. If you make something a lexical, it's not going to be addressable +# from outside the debugger even if you know its name. + +# This file is automatically included if you do perl -d. +# It's probably not useful to include this yourself. +# +# Before venturing further into these twisty passages, it is +# wise to read the perldebguts man page or risk the ire of dragons. +# +# (It should be noted that perldebguts will tell you a lot about +# the underlying mechanics of how the debugger interfaces into the +# Perl interpreter, but not a lot about the debugger itself. The new +# comments in this code try to address this problem.) + +# Note that no subroutine call is possible until &DB::sub is defined +# (for subroutines defined outside of the package DB). In fact the same is +# true if $deep is not defined. + +# Enhanced by ilya@math.ohio-state.edu (Ilya Zakharevich) + +# modified Perl debugger, to be run from Emacs in perldb-mode +# Ray Lischner (uunet!mntgfx!lisch) as of 5 Nov 1990 +# Johan Vromans -- upgrade to 4.0 pl 10 +# Ilya Zakharevich -- patches after 5.001 (and some before ;-) + +# (We have made efforts to clarify the comments in the change log +# in other places; some of them may seem somewhat obscure as they +# were originally written, and explaining them away from the code +# in question seems conterproductive.. -JM) + +######################################################################## +# Changes: 0.94 +# + A lot of things changed after 0.94. First of all, core now informs +# debugger about entry into XSUBs, overloaded operators, tied operations, +# BEGIN and END. Handy with `O f=2'. +# + This can make debugger a little bit too verbose, please be patient +# and report your problems promptly. +# + Now the option frame has 3 values: 0,1,2. XXX Document! +# + Note that if DESTROY returns a reference to the object (or object), +# the deletion of data may be postponed until the next function call, +# due to the need to examine the return value. +# +# Changes: 0.95 +# + `v' command shows versions. +# +# Changes: 0.96 +# + `v' command shows version of readline. +# primitive completion works (dynamic variables, subs for `b' and `l', +# options). Can `p %var' +# + Better help (`h <' now works). New commands <<, >>, {, {{. +# {dump|print}_trace() coded (to be able to do it from <<cmd). +# + `c sub' documented. +# + At last enough magic combined to stop after the end of debuggee. +# + !! should work now (thanks to Emacs bracket matching an extra +# `]' in a regexp is caught). +# + `L', `D' and `A' span files now (as documented). +# + Breakpoints in `require'd code are possible (used in `R'). +# + Some additional words on internal work of debugger. +# + `b load filename' implemented. +# + `b postpone subr' implemented. +# + now only `q' exits debugger (overwritable on $inhibit_exit). +# + When restarting debugger breakpoints/actions persist. +# + Buglet: When restarting debugger only one breakpoint/action per +# autoloaded function persists. +# +# Changes: 0.97: NonStop will not stop in at_exit(). +# + Option AutoTrace implemented. +# + Trace printed differently if frames are printed too. +# + new `inhibitExit' option. +# + printing of a very long statement interruptible. +# Changes: 0.98: New command `m' for printing possible methods +# + 'l -' is a synonym for `-'. +# + Cosmetic bugs in printing stack trace. +# + `frame' & 8 to print "expanded args" in stack trace. +# + Can list/break in imported subs. +# + new `maxTraceLen' option. +# + frame & 4 and frame & 8 granted. +# + new command `m' +# + nonstoppable lines do not have `:' near the line number. +# + `b compile subname' implemented. +# + Will not use $` any more. +# + `-' behaves sane now. +# Changes: 0.99: Completion for `f', `m'. +# + `m' will remove duplicate names instead of duplicate functions. +# + `b load' strips trailing whitespace. +# completion ignores leading `|'; takes into account current package +# when completing a subroutine name (same for `l'). +# Changes: 1.07: Many fixed by tchrist 13-March-2000 +# BUG FIXES: +# + Added bare minimal security checks on perldb rc files, plus +# comments on what else is needed. +# + Fixed the ornaments that made "|h" completely unusable. +# They are not used in print_help if they will hurt. Strip pod +# if we're paging to less. +# + Fixed mis-formatting of help messages caused by ornaments +# to restore Larry's original formatting. +# + Fixed many other formatting errors. The code is still suboptimal, +# and needs a lot of work at restructuring. It's also misindented +# in many places. +# + Fixed bug where trying to look at an option like your pager +# shows "1". +# + Fixed some $? processing. Note: if you use csh or tcsh, you will +# lose. You should consider shell escapes not using their shell, +# or else not caring about detailed status. This should really be +# unified into one place, too. +# + Fixed bug where invisible trailing whitespace on commands hoses you, +# tricking Perl into thinking you weren't calling a debugger command! +# + Fixed bug where leading whitespace on commands hoses you. (One +# suggests a leading semicolon or any other irrelevant non-whitespace +# to indicate literal Perl code.) +# + Fixed bugs that ate warnings due to wrong selected handle. +# + Fixed a precedence bug on signal stuff. +# + Fixed some unseemly wording. +# + Fixed bug in help command trying to call perl method code. +# + Fixed to call dumpvar from exception handler. SIGPIPE killed us. +# ENHANCEMENTS: +# + Added some comments. This code is still nasty spaghetti. +# + Added message if you clear your pre/post command stacks which was +# very easy to do if you just typed a bare >, <, or {. (A command +# without an argument should *never* be a destructive action; this +# API is fundamentally screwed up; likewise option setting, which +# is equally buggered.) +# + Added command stack dump on argument of "?" for >, <, or {. +# + Added a semi-built-in doc viewer command that calls man with the +# proper %Config::Config path (and thus gets caching, man -k, etc), +# or else perldoc on obstreperous platforms. +# + Added to and rearranged the help information. +# + Detected apparent misuse of { ... } to declare a block; this used +# to work but now is a command, and mysteriously gave no complaint. +# +# Changes: 1.08: Apr 25, 2001 Jon Eveland <jweveland@yahoo.com> +# BUG FIX: +# + This patch to perl5db.pl cleans up formatting issues on the help +# summary (h h) screen in the debugger. Mostly columnar alignment +# issues, plus converted the printed text to use all spaces, since +# tabs don't seem to help much here. +# +# Changes: 1.09: May 19, 2001 Ilya Zakharevich <ilya@math.ohio-state.edu> +# Minor bugs corrected; +# + Support for auto-creation of new TTY window on startup, either +# unconditionally, or if started as a kid of another debugger session; +# + New `O'ption CreateTTY +# I<CreateTTY> bits control attempts to create a new TTY on events: +# 1: on fork() +# 2: debugger is started inside debugger +# 4: on startup +# + Code to auto-create a new TTY window on OS/2 (currently one +# extra window per session - need named pipes to have more...); +# + Simplified interface for custom createTTY functions (with a backward +# compatibility hack); now returns the TTY name to use; return of '' +# means that the function reset the I/O handles itself; +# + Better message on the semantic of custom createTTY function; +# + Convert the existing code to create a TTY into a custom createTTY +# function; +# + Consistent support for TTY names of the form "TTYin,TTYout"; +# + Switch line-tracing output too to the created TTY window; +# + make `b fork' DWIM with CORE::GLOBAL::fork; +# + High-level debugger API cmd_*(): +# cmd_b_load($filenamepart) # b load filenamepart +# cmd_b_line($lineno [, $cond]) # b lineno [cond] +# cmd_b_sub($sub [, $cond]) # b sub [cond] +# cmd_stop() # Control-C +# cmd_d($lineno) # d lineno (B) +# The cmd_*() API returns FALSE on failure; in this case it outputs +# the error message to the debugging output. +# + Low-level debugger API +# break_on_load($filename) # b load filename +# @files = report_break_on_load() # List files with load-breakpoints +# breakable_line_in_filename($name, $from [, $to]) +# # First breakable line in the +# # range $from .. $to. $to defaults +# # to $from, and may be less than +# # $to +# breakable_line($from [, $to]) # Same for the current file +# break_on_filename_line($name, $lineno [, $cond]) +# # Set breakpoint,$cond defaults to +# # 1 +# break_on_filename_line_range($name, $from, $to [, $cond]) +# # As above, on the first +# # breakable line in range +# break_on_line($lineno [, $cond]) # As above, in the current file +# break_subroutine($sub [, $cond]) # break on the first breakable line +# ($name, $from, $to) = subroutine_filename_lines($sub) +# # The range of lines of the text +# The low-level API returns TRUE on success, and die()s on failure. +# +# Changes: 1.10: May 23, 2001 Daniel Lewart <d-lewart@uiuc.edu> +# BUG FIXES: +# + Fixed warnings generated by "perl -dWe 42" +# + Corrected spelling errors +# + Squeezed Help (h) output into 80 columns +# +# Changes: 1.11: May 24, 2001 David Dyck <dcd@tc.fluke.com> +# + Made "x @INC" work like it used to +# +# Changes: 1.12: May 24, 2001 Daniel Lewart <d-lewart@uiuc.edu> +# + Fixed warnings generated by "O" (Show debugger options) +# + Fixed warnings generated by "p 42" (Print expression) +# Changes: 1.13: Jun 19, 2001 Scott.L.Miller@compaq.com +# + Added windowSize option +# Changes: 1.14: Oct 9, 2001 multiple +# + Clean up after itself on VMS (Charles Lane in 12385) +# + Adding "@ file" syntax (Peter Scott in 12014) +# + Debug reloading selfloaded stuff (Ilya Zakharevich in 11457) +# + $^S and other debugger fixes (Ilya Zakharevich in 11120) +# + Forgot a my() declaration (Ilya Zakharevich in 11085) +# Changes: 1.15: Nov 6, 2001 Michael G Schwern <schwern@pobox.com> +# + Updated 1.14 change log +# + Added *dbline explainatory comments +# + Mentioning perldebguts man page +# Changes: 1.16: Feb 15, 2002 Mark-Jason Dominus <mjd@plover.com> +# + $onetimeDump improvements +# Changes: 1.17: Feb 20, 2002 Richard Foley <richard.foley@rfi.net> +# Moved some code to cmd_[.]()'s for clarity and ease of handling, +# rationalised the following commands and added cmd_wrapper() to +# enable switching between old and frighteningly consistent new +# behaviours for diehards: 'o CommandSet=pre580' (sigh...) +# a(add), A(del) # action expr (added del by line) +# + b(add), B(del) # break [line] (was b,D) +# + w(add), W(del) # watch expr (was W,W) +# # added del by expr +# + h(summary), h h(long) # help (hh) (was h h,h) +# + m(methods), M(modules) # ... (was m,v) +# + o(option) # lc (was O) +# + v(view code), V(view Variables) # ... (was w,V) +# Changes: 1.18: Mar 17, 2002 Richard Foley <richard.foley@rfi.net> +# + fixed missing cmd_O bug +# Changes: 1.19: Mar 29, 2002 Spider Boardman +# + Added missing local()s -- DB::DB is called recursively. +# Changes: 1.20: Feb 17, 2003 Richard Foley <richard.foley@rfi.net> +# + pre'n'post commands no longer trashed with no args +# + watch val joined out of eval() +# Changes: 1.21: Jun 04, 2003 Joe McMahon <mcmahon@ibiblio.org> +# + Added comments and reformatted source. No bug fixes/enhancements. +# + Includes cleanup by Robin Barker and Jarkko Hietaniemi. +# Changes: 1.22 Jun 09, 2003 Alex Vandiver <alexmv@MIT.EDU> +# + Flush stdout/stderr before the debugger prompt is printed. +# Changes: 1.23: Dec 21, 2003 Dominique Quatravaux +# + Fix a side-effect of bug #24674 in the perl debugger ("odd taint bug") +# Changes: 1.24: Mar 03, 2004 Richard Foley <richard.foley@rfi.net> +# + Added command to save all debugger commands for sourcing later. +# + Added command to display parent inheritance tree of given class. +# + Fixed minor newline in history bug. +# Changes: 1.25: Apr 17, 2004 Richard Foley <richard.foley@rfi.net> +# + Fixed option bug (setting invalid options + not recognising valid short forms) +# Changes: 1.26: Apr 22, 2004 Richard Foley <richard.foley@rfi.net> +# + unfork the 5.8.x and 5.9.x debuggers. +# + whitespace and assertions call cleanup across versions +# + H * deletes (resets) history +# + i now handles Class + blessed objects +# Changes: 1.27: May 09, 2004 Richard Foley <richard.foley@rfi.net> +# + updated pod page references - clunky. +# + removed windowid restriction for forking into an xterm. +# + more whitespace again. +# + wrapped restart and enabled rerun [-n] (go back n steps) command. +# Changes: 1.28: Oct 12, 2004 Richard Foley <richard.foley@rfi.net> +# + Added threads support (inc. e and E commands) +# Changes: 1.29: Nov 28, 2006 Bo Lindbergh <blgl@hagernas.com> +# + Added macosx_get_fork_TTY support +# Changes: 1.30: Mar 06, 2007 Andreas Koenig <andk@cpan.org> +# + Added HistFile, HistSize +# Changes: 1.31 +# + Remove support for assertions and -A +# + stop NEXT::AUTOLOAD from emitting warnings under the debugger. RT #25053 +# + "update for Mac OS X 10.5" [finding the tty device] +# + "What I needed to get the forked debugger to work" [on VMS] +# + [perl #57016] debugger: o warn=0 die=0 ignored +# + Note, but don't use, PERLDBf_SAVESRC +# + Fix #7013: lvalue subs not working inside debugger +######################################################################## + +=head1 DEBUGGER INITIALIZATION + +The debugger starts up in phases. + +=head2 BASIC SETUP + +First, it initializes the environment it wants to run in: turning off +warnings during its own compilation, defining variables which it will need +to avoid warnings later, setting itself up to not exit when the program +terminates, and defaulting to printing return values for the C<r> command. + +=cut + +# Needed for the statement after exec(): +# +# This BEGIN block is simply used to switch off warnings during debugger +# compiliation. Probably it would be better practice to fix the warnings, +# but this is how it's done at the moment. + +BEGIN { + $ini_warn = $^W; + $^W = 0; +} # Switch compilation warnings off until another BEGIN. + +local ($^W) = 0; # Switch run-time warnings off during init. + +=head2 THREADS SUPPORT + +If we are running under a threaded Perl, we require threads and threads::shared +if the environment variable C<PERL5DB_THREADED> is set, to enable proper +threaded debugger control. C<-dt> can also be used to set this. + +Each new thread will be announced and the debugger prompt will always inform +you of each new thread created. It will also indicate the thread id in which +we are currently running within the prompt like this: + + [tid] DB<$i> + +Where C<[tid]> is an integer thread id and C<$i> is the familiar debugger +command prompt. The prompt will show: C<[0]> when running under threads, but +not actually in a thread. C<[tid]> is consistent with C<gdb> usage. + +While running under threads, when you set or delete a breakpoint (etc.), this +will apply to all threads, not just the currently running one. When you are +in a currently executing thread, you will stay there until it completes. With +the current implementation it is not currently possible to hop from one thread +to another. + +The C<e> and C<E> commands are currently fairly minimal - see C<h e> and C<h E>. + +Note that threading support was built into the debugger as of Perl version +C<5.8.6> and debugger version C<1.2.8>. + +=cut + +BEGIN { + # ensure we can share our non-threaded variables or no-op + if ($ENV{PERL5DB_THREADED}) { + require threads; + require threads::shared; + import threads::shared qw(share); + $DBGR; + share(\$DBGR); + lock($DBGR); + print "Threads support enabled\n"; + } else { + *lock = sub(*) {}; + *share = sub(*) {}; + } +} + +# This would probably be better done with "use vars", but that wasn't around +# when this code was originally written. (Neither was "use strict".) And on +# the principle of not fiddling with something that was working, this was +# left alone. +warn( # Do not ;-) + # These variables control the execution of 'dumpvar.pl'. + $dumpvar::hashDepth, + $dumpvar::arrayDepth, + $dumpvar::dumpDBFiles, + $dumpvar::dumpPackages, + $dumpvar::quoteHighBit, + $dumpvar::printUndef, + $dumpvar::globPrint, + $dumpvar::usageOnly, + + # used to save @ARGV and extract any debugger-related flags. + @ARGS, + + # used to control die() reporting in diesignal() + $Carp::CarpLevel, + + # used to prevent multiple entries to diesignal() + # (if for instance diesignal() itself dies) + $panic, + + # used to prevent the debugger from running nonstop + # after a restart + $second_time, + ) + if 0; + +foreach my $k (keys (%INC)) { + &share(\$main::{'_<'.$filename}); +}; + +# Command-line + PERLLIB: +# Save the contents of @INC before they are modified elsewhere. +@ini_INC = @INC; + +# This was an attempt to clear out the previous values of various +# trapped errors. Apparently it didn't help. XXX More info needed! +# $prevwarn = $prevdie = $prevbus = $prevsegv = ''; # Does not help?! + +# We set these variables to safe values. We don't want to blindly turn +# off warnings, because other packages may still want them. +$trace = $signal = $single = 0; # Uninitialized warning suppression + # (local $^W cannot help - other packages!). + +# Default to not exiting when program finishes; print the return +# value when the 'r' command is used to return from a subroutine. +$inhibit_exit = $option{PrintRet} = 1; + +=head1 OPTION PROCESSING + +The debugger's options are actually spread out over the debugger itself and +C<dumpvar.pl>; some of these are variables to be set, while others are +subs to be called with a value. To try to make this a little easier to +manage, the debugger uses a few data structures to define what options +are legal and how they are to be processed. + +First, the C<@options> array defines the I<names> of all the options that +are to be accepted. + +=cut + +@options = qw( + CommandSet HistFile HistSize + hashDepth arrayDepth dumpDepth + DumpDBFiles DumpPackages DumpReused + compactDump veryCompact quote + HighBit undefPrint globPrint + PrintRet UsageOnly frame + AutoTrace TTY noTTY + ReadLine NonStop LineInfo + maxTraceLen recallCommand ShellBang + pager tkRunning ornaments + signalLevel warnLevel dieLevel + inhibit_exit ImmediateStop bareStringify + CreateTTY RemotePort windowSize + DollarCaretP +); + +@RememberOnROptions = qw(DollarCaretP); + +=pod + +Second, C<optionVars> lists the variables that each option uses to save its +state. + +=cut + +%optionVars = ( + hashDepth => \$dumpvar::hashDepth, + arrayDepth => \$dumpvar::arrayDepth, + CommandSet => \$CommandSet, + DumpDBFiles => \$dumpvar::dumpDBFiles, + DumpPackages => \$dumpvar::dumpPackages, + DumpReused => \$dumpvar::dumpReused, + HighBit => \$dumpvar::quoteHighBit, + undefPrint => \$dumpvar::printUndef, + globPrint => \$dumpvar::globPrint, + UsageOnly => \$dumpvar::usageOnly, + CreateTTY => \$CreateTTY, + bareStringify => \$dumpvar::bareStringify, + frame => \$frame, + AutoTrace => \$trace, + inhibit_exit => \$inhibit_exit, + maxTraceLen => \$maxtrace, + ImmediateStop => \$ImmediateStop, + RemotePort => \$remoteport, + windowSize => \$window, + HistFile => \$histfile, + HistSize => \$histsize, +); + +=pod + +Third, C<%optionAction> defines the subroutine to be called to process each +option. + +=cut + +%optionAction = ( + compactDump => \&dumpvar::compactDump, + veryCompact => \&dumpvar::veryCompact, + quote => \&dumpvar::quote, + TTY => \&TTY, + noTTY => \&noTTY, + ReadLine => \&ReadLine, + NonStop => \&NonStop, + LineInfo => \&LineInfo, + recallCommand => \&recallCommand, + ShellBang => \&shellBang, + pager => \&pager, + signalLevel => \&signalLevel, + warnLevel => \&warnLevel, + dieLevel => \&dieLevel, + tkRunning => \&tkRunning, + ornaments => \&ornaments, + RemotePort => \&RemotePort, + DollarCaretP => \&DollarCaretP, +); + +=pod + +Last, the C<%optionRequire> notes modules that must be C<require>d if an +option is used. + +=cut + +# Note that this list is not complete: several options not listed here +# actually require that dumpvar.pl be loaded for them to work, but are +# not in the table. A subsequent patch will correct this problem; for +# the moment, we're just recommenting, and we are NOT going to change +# function. +%optionRequire = ( + compactDump => 'dumpvar.pl', + veryCompact => 'dumpvar.pl', + quote => 'dumpvar.pl', +); + +=pod + +There are a number of initialization-related variables which can be set +by putting code to set them in a BEGIN block in the C<PERL5DB> environment +variable. These are: + +=over 4 + +=item C<$rl> - readline control XXX needs more explanation + +=item C<$warnLevel> - whether or not debugger takes over warning handling + +=item C<$dieLevel> - whether or not debugger takes over die handling + +=item C<$signalLevel> - whether or not debugger takes over signal handling + +=item C<$pre> - preprompt actions (array reference) + +=item C<$post> - postprompt actions (array reference) + +=item C<$pretype> + +=item C<$CreateTTY> - whether or not to create a new TTY for this debugger + +=item C<$CommandSet> - which command set to use (defaults to new, documented set) + +=back + +=cut + +# These guys may be defined in $ENV{PERL5DB} : +$rl = 1 unless defined $rl; +$warnLevel = 1 unless defined $warnLevel; +$dieLevel = 1 unless defined $dieLevel; +$signalLevel = 1 unless defined $signalLevel; +$pre = [] unless defined $pre; +$post = [] unless defined $post; +$pretype = [] unless defined $pretype; +$CreateTTY = 3 unless defined $CreateTTY; +$CommandSet = '580' unless defined $CommandSet; + +share($rl); +share($warnLevel); +share($dieLevel); +share($signalLevel); +share($pre); +share($post); +share($pretype); +share($rl); +share($CreateTTY); +share($CommandSet); + +=pod + +The default C<die>, C<warn>, and C<signal> handlers are set up. + +=cut + +warnLevel($warnLevel); +dieLevel($dieLevel); +signalLevel($signalLevel); + +=pod + +The pager to be used is needed next. We try to get it from the +environment first. If it's not defined there, we try to find it in +the Perl C<Config.pm>. If it's not there, we default to C<more>. We +then call the C<pager()> function to save the pager name. + +=cut + +# This routine makes sure $pager is set up so that '|' can use it. +pager( + + # If PAGER is defined in the environment, use it. + defined $ENV{PAGER} + ? $ENV{PAGER} + + # If not, see if Config.pm defines it. + : eval { require Config } + && defined $Config::Config{pager} + ? $Config::Config{pager} + + # If not, fall back to 'more'. + : 'more' + ) + unless defined $pager; + +=pod + +We set up the command to be used to access the man pages, the command +recall character (C<!> unless otherwise defined) and the shell escape +character (C<!> unless otherwise defined). Yes, these do conflict, and +neither works in the debugger at the moment. + +=cut + +setman(); + +# Set up defaults for command recall and shell escape (note: +# these currently don't work in linemode debugging). +&recallCommand("!") unless defined $prc; +&shellBang("!") unless defined $psh; + +=pod + +We then set up the gigantic string containing the debugger help. +We also set the limit on the number of arguments we'll display during a +trace. + +=cut + +sethelp(); + +# If we didn't get a default for the length of eval/stack trace args, +# set it here. +$maxtrace = 400 unless defined $maxtrace; + +=head2 SETTING UP THE DEBUGGER GREETING + +The debugger I<greeting> helps to inform the user how many debuggers are +running, and whether the current debugger is the primary or a child. + +If we are the primary, we just hang onto our pid so we'll have it when +or if we start a child debugger. If we are a child, we'll set things up +so we'll have a unique greeting and so the parent will give us our own +TTY later. + +We save the current contents of the C<PERLDB_PIDS> environment variable +because we mess around with it. We'll also need to hang onto it because +we'll need it if we restart. + +Child debuggers make a label out of the current PID structure recorded in +PERLDB_PIDS plus the new PID. They also mark themselves as not having a TTY +yet so the parent will give them one later via C<resetterm()>. + +=cut + +# Save the current contents of the environment; we're about to +# much with it. We'll need this if we have to restart. +$ini_pids = $ENV{PERLDB_PIDS}; + +if ( defined $ENV{PERLDB_PIDS} ) { + + # We're a child. Make us a label out of the current PID structure + # recorded in PERLDB_PIDS plus our (new) PID. Mark us as not having + # a term yet so the parent will give us one later via resetterm(). + + my $env_pids = $ENV{PERLDB_PIDS}; + $pids = "[$env_pids]"; + + # Unless we are on OpenVMS, all programs under the DCL shell run under + # the same PID. + + if (($^O eq 'VMS') && ($env_pids =~ /\b$$\b/)) { + $term_pid = $$; + } + else { + $ENV{PERLDB_PIDS} .= "->$$"; + $term_pid = -1; + } + +} ## end if (defined $ENV{PERLDB_PIDS... +else { + + # We're the parent PID. Initialize PERLDB_PID in case we end up with a + # child debugger, and mark us as the parent, so we'll know to set up + # more TTY's is we have to. + $ENV{PERLDB_PIDS} = "$$"; + $pids = "[pid=$$]"; + $term_pid = $$; +} + +$pidprompt = ''; + +# Sets up $emacs as a synonym for $slave_editor. +*emacs = $slave_editor if $slave_editor; # May be used in afterinit()... + +=head2 READING THE RC FILE + +The debugger will read a file of initialization options if supplied. If +running interactively, this is C<.perldb>; if not, it's C<perldb.ini>. + +=cut + +# As noted, this test really doesn't check accurately that the debugger +# is running at a terminal or not. + +my $dev_tty = '/dev/tty'; + $dev_tty = 'TT:' if ($^O eq 'VMS'); +if ( -e $dev_tty ) { # this is the wrong metric! + $rcfile = ".perldb"; +} +else { + $rcfile = "perldb.ini"; +} + +=pod + +The debugger does a safety test of the file to be read. It must be owned +either by the current user or root, and must only be writable by the owner. + +=cut + +# This wraps a safety test around "do" to read and evaluate the init file. +# +# This isn't really safe, because there's a race +# between checking and opening. The solution is to +# open and fstat the handle, but then you have to read and +# eval the contents. But then the silly thing gets +# your lexical scope, which is unfortunate at best. +sub safe_do { + my $file = shift; + + # Just exactly what part of the word "CORE::" don't you understand? + local $SIG{__WARN__}; + local $SIG{__DIE__}; + + unless ( is_safe_file($file) ) { + CORE::warn <<EO_GRIPE; +perldb: Must not source insecure rcfile $file. + You or the superuser must be the owner, and it must not + be writable by anyone but its owner. +EO_GRIPE + return; + } ## end unless (is_safe_file($file... + + do $file; + CORE::warn("perldb: couldn't parse $file: $@") if $@; +} ## end sub safe_do + +# This is the safety test itself. +# +# Verifies that owner is either real user or superuser and that no +# one but owner may write to it. This function is of limited use +# when called on a path instead of upon a handle, because there are +# no guarantees that filename (by dirent) whose file (by ino) is +# eventually accessed is the same as the one tested. +# Assumes that the file's existence is not in doubt. +sub is_safe_file { + my $path = shift; + stat($path) || return; # mysteriously vaporized + my ( $dev, $ino, $mode, $nlink, $uid, $gid ) = stat(_); + + return 0 if $uid != 0 && $uid != $<; + return 0 if $mode & 022; + return 1; +} ## end sub is_safe_file + +# If the rcfile (whichever one we decided was the right one to read) +# exists, we safely do it. +if ( -f $rcfile ) { + safe_do("./$rcfile"); +} + +# If there isn't one here, try the user's home directory. +elsif ( defined $ENV{HOME} && -f "$ENV{HOME}/$rcfile" ) { + safe_do("$ENV{HOME}/$rcfile"); +} + +# Else try the login directory. +elsif ( defined $ENV{LOGDIR} && -f "$ENV{LOGDIR}/$rcfile" ) { + safe_do("$ENV{LOGDIR}/$rcfile"); +} + +# If the PERLDB_OPTS variable has options in it, parse those out next. +if ( defined $ENV{PERLDB_OPTS} ) { + parse_options( $ENV{PERLDB_OPTS} ); +} + +=pod + +The last thing we do during initialization is determine which subroutine is +to be used to obtain a new terminal when a new debugger is started. Right now, +the debugger only handles X Windows, OS/2, and Mac OS X (darwin). + +=cut + +# Set up the get_fork_TTY subroutine to be aliased to the proper routine. +# Works if you're running an xterm or xterm-like window, or you're on +# OS/2, or on Mac OS X. This may need some expansion. + +if (not defined &get_fork_TTY) # only if no routine exists +{ + if (defined $ENV{TERM} # If we know what kind + # of terminal this is, + and $ENV{TERM} eq 'xterm' # and it's an xterm, + and defined $ENV{DISPLAY} # and what display it's on, + ) + { + *get_fork_TTY = \&xterm_get_fork_TTY; # use the xterm version + } + elsif ( $^O eq 'os2' ) { # If this is OS/2, + *get_fork_TTY = \&os2_get_fork_TTY; # use the OS/2 version + } + elsif ( $^O eq 'darwin' # If this is Mac OS X + and defined $ENV{TERM_PROGRAM} # and we're running inside + and $ENV{TERM_PROGRAM} + eq 'Apple_Terminal' # Terminal.app + ) + { + *get_fork_TTY = \&macosx_get_fork_TTY; # use the Mac OS X version + } +} ## end if (not defined &get_fork_TTY... + +# untaint $^O, which may have been tainted by the last statement. +# see bug [perl #24674] +$^O =~ m/^(.*)\z/; +$^O = $1; + +# Here begin the unreadable code. It needs fixing. + +=head2 RESTART PROCESSING + +This section handles the restart command. When the C<R> command is invoked, it +tries to capture all of the state it can into environment variables, and +then sets C<PERLDB_RESTART>. When we start executing again, we check to see +if C<PERLDB_RESTART> is there; if so, we reload all the information that +the R command stuffed into the environment variables. + + PERLDB_RESTART - flag only, contains no restart data itself. + PERLDB_HIST - command history, if it's available + PERLDB_ON_LOAD - breakpoints set by the rc file + PERLDB_POSTPONE - subs that have been loaded/not executed, and have actions + PERLDB_VISITED - files that had breakpoints + PERLDB_FILE_... - breakpoints for a file + PERLDB_OPT - active options + PERLDB_INC - the original @INC + PERLDB_PRETYPE - preprompt debugger actions + PERLDB_PRE - preprompt Perl code + PERLDB_POST - post-prompt Perl code + PERLDB_TYPEAHEAD - typeahead captured by readline() + +We chug through all these variables and plug the values saved in them +back into the appropriate spots in the debugger. + +=cut + +if ( exists $ENV{PERLDB_RESTART} ) { + + # We're restarting, so we don't need the flag that says to restart anymore. + delete $ENV{PERLDB_RESTART}; + + # $restart = 1; + @hist = get_list('PERLDB_HIST'); + %break_on_load = get_list("PERLDB_ON_LOAD"); + %postponed = get_list("PERLDB_POSTPONE"); + + share(@hist); + share(@truehist); + share(%break_on_load); + share(%postponed); + + # restore breakpoints/actions + my @had_breakpoints = get_list("PERLDB_VISITED"); + for ( 0 .. $#had_breakpoints ) { + my %pf = get_list("PERLDB_FILE_$_"); + $postponed_file{ $had_breakpoints[$_] } = \%pf if %pf; + } + + # restore options + my %opt = get_list("PERLDB_OPT"); + my ( $opt, $val ); + while ( ( $opt, $val ) = each %opt ) { + $val =~ s/[\\\']/\\$1/g; + parse_options("$opt'$val'"); + } + + # restore original @INC + @INC = get_list("PERLDB_INC"); + @ini_INC = @INC; + + # return pre/postprompt actions and typeahead buffer + $pretype = [ get_list("PERLDB_PRETYPE") ]; + $pre = [ get_list("PERLDB_PRE") ]; + $post = [ get_list("PERLDB_POST") ]; + @typeahead = get_list( "PERLDB_TYPEAHEAD", @typeahead ); +} ## end if (exists $ENV{PERLDB_RESTART... + +=head2 SETTING UP THE TERMINAL + +Now, we'll decide how the debugger is going to interact with the user. +If there's no TTY, we set the debugger to run non-stop; there's not going +to be anyone there to enter commands. + +=cut + +if ($notty) { + $runnonstop = 1; + share($runnonstop); +} + +=pod + +If there is a TTY, we have to determine who it belongs to before we can +proceed. If this is a slave editor or graphical debugger (denoted by +the first command-line switch being '-emacs'), we shift this off and +set C<$rl> to 0 (XXX ostensibly to do straight reads). + +=cut + +else { + + # Is Perl being run from a slave editor or graphical debugger? + # If so, don't use readline, and set $slave_editor = 1. + $slave_editor = + ( ( defined $main::ARGV[0] ) and ( $main::ARGV[0] eq '-emacs' ) ); + $rl = 0, shift(@main::ARGV) if $slave_editor; + + #require Term::ReadLine; + +=pod + +We then determine what the console should be on various systems: + +=over 4 + +=item * Cygwin - We use C<stdin> instead of a separate device. + +=cut + + if ( $^O eq 'cygwin' ) { + + # /dev/tty is binary. use stdin for textmode + undef $console; + } + +=item * Unix - use C</dev/tty>. + +=cut + + elsif ( -e "/dev/tty" ) { + $console = "/dev/tty"; + } + +=item * Windows or MSDOS - use C<con>. + +=cut + + elsif ( $^O eq 'dos' or -e "con" or $^O eq 'MSWin32' ) { + $console = "con"; + } + +=item * MacOS - use C<Dev:Console:Perl Debug> if this is the MPW version; C<Dev: +Console> if not. + +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. + +=cut + + elsif ( $^O eq 'MacOS' ) { + if ( $MacPerl::Version !~ /MPW/ ) { + $console = + "Dev:Console:Perl Debug"; # Separate window for application + } + else { + $console = "Dev:Console"; + } + } ## end elsif ($^O eq 'MacOS') + +=item * VMS - use C<sys$command>. + +=cut + + else { + + # everything else is ... + $console = "sys\$command"; + } + +=pod + +=back + +Several other systems don't use a specific console. We C<undef $console> +for those (Windows using a slave editor/graphical debugger, NetWare, OS/2 +with a slave editor, Epoc). + +=cut + + if ( ( $^O eq 'MSWin32' ) and ( $slave_editor or defined $ENV{EMACS} ) ) { + + # /dev/tty is binary. use stdin for textmode + $console = undef; + } + + if ( $^O eq 'NetWare' ) { + + # /dev/tty is binary. use stdin for textmode + $console = undef; + } + + # In OS/2, we need to use STDIN to get textmode too, even though + # it pretty much looks like Unix otherwise. + if ( defined $ENV{OS2_SHELL} and ( $slave_editor or $ENV{WINDOWID} ) ) + { # In OS/2 + $console = undef; + } + + # EPOC also falls into the 'got to use STDIN' camp. + if ( $^O eq 'epoc' ) { + $console = undef; + } + +=pod + +If there is a TTY hanging around from a parent, we use that as the console. + +=cut + + $console = $tty if defined $tty; + +=head2 SOCKET HANDLING + +The debugger is capable of opening a socket and carrying out a debugging +session over the socket. + +If C<RemotePort> was defined in the options, the debugger assumes that it +should try to start a debugging session on that port. It builds the socket +and then tries to connect the input and output filehandles to it. + +=cut + + # Handle socket stuff. + + if ( defined $remoteport ) { + + # If RemotePort was defined in the options, connect input and output + # to the socket. + require IO::Socket; + $OUT = new IO::Socket::INET( + Timeout => '10', + PeerAddr => $remoteport, + Proto => 'tcp', + ); + if ( !$OUT ) { die "Unable to connect to remote host: $remoteport\n"; } + $IN = $OUT; + } ## end if (defined $remoteport) + +=pod + +If no C<RemotePort> was defined, and we want to create a TTY on startup, +this is probably a situation where multiple debuggers are running (for example, +a backticked command that starts up another debugger). We create a new IN and +OUT filehandle, and do the necessary mojo to create a new TTY if we know how +and if we can. + +=cut + + # Non-socket. + else { + + # Two debuggers running (probably a system or a backtick that invokes + # the debugger itself under the running one). create a new IN and OUT + # filehandle, and do the necessary mojo to create a new tty if we + # know how, and we can. + create_IN_OUT(4) if $CreateTTY & 4; + if ($console) { + + # If we have a console, check to see if there are separate ins and + # outs to open. (They are assumed identical if not.) + + my ( $i, $o ) = split /,/, $console; + $o = $i unless defined $o; + + # read/write on in, or just read, or read on STDIN. + open( IN, "+<$i" ) + || open( IN, "<$i" ) + || open( IN, "<&STDIN" ); + + # read/write/create/clobber out, or write/create/clobber out, + # or merge with STDERR, or merge with STDOUT. + open( OUT, "+>$o" ) + || open( OUT, ">$o" ) + || open( OUT, ">&STDERR" ) + || open( OUT, ">&STDOUT" ); # so we don't dongle stdout + + } ## end if ($console) + elsif ( not defined $console ) { + + # No console. Open STDIN. + open( IN, "<&STDIN" ); + + # merge with STDERR, or with STDOUT. + open( OUT, ">&STDERR" ) + || open( OUT, ">&STDOUT" ); # so we don't dongle stdout + $console = 'STDIN/OUT'; + } ## end elsif (not defined $console) + + # Keep copies of the filehandles so that when the pager runs, it + # can close standard input without clobbering ours. + $IN = \*IN, $OUT = \*OUT if $console or not defined $console; + } ## end elsif (from if(defined $remoteport)) + + # Unbuffer DB::OUT. We need to see responses right away. + my $previous = select($OUT); + $| = 1; # for DB::OUT + select($previous); + + # Line info goes to debugger output unless pointed elsewhere. + # Pointing elsewhere makes it possible for slave editors to + # keep track of file and position. We have both a filehandle + # and a I/O description to keep track of. + $LINEINFO = $OUT unless defined $LINEINFO; + $lineinfo = $console unless defined $lineinfo; + # share($LINEINFO); # <- unable to share globs + share($lineinfo); # + +=pod + +To finish initialization, we show the debugger greeting, +and then call the C<afterinit()> subroutine if there is one. + +=cut + + # Show the debugger greeting. + $header =~ s/.Header: ([^,]+),v(\s+\S+\s+\S+).*$/$1$2/; + unless ($runnonstop) { + local $\ = ''; + local $, = ''; + if ( $term_pid eq '-1' ) { + print $OUT "\nDaughter DB session started...\n"; + } + else { + print $OUT "\nLoading DB routines from $header\n"; + print $OUT ( + "Editor support ", + $slave_editor ? "enabled" : "available", ".\n" + ); + print $OUT +"\nEnter h or `h h' for help, or `$doccmd perldebug' for more help.\n\n"; + } ## end else [ if ($term_pid eq '-1') + } ## end unless ($runnonstop) +} ## end else [ if ($notty) + +# XXX This looks like a bug to me. +# Why copy to @ARGS and then futz with @args? +@ARGS = @ARGV; +for (@args) { + # Make sure backslashes before single quotes are stripped out, and + # keep args unless they are numeric (XXX why?) + # s/\'/\\\'/g; # removed while not justified understandably + # s/(.*)/'$1'/ unless /^-?[\d.]+$/; # ditto +} + +# If there was an afterinit() sub defined, call it. It will get +# executed in our scope, so it can fiddle with debugger globals. +if ( defined &afterinit ) { # May be defined in $rcfile + &afterinit(); +} + +# Inform us about "Stack dump during die enabled ..." in dieLevel(). +$I_m_init = 1; + +############################################################ Subroutines + +=head1 SUBROUTINES + +=head2 DB + +This gigantic subroutine is the heart of the debugger. Called before every +statement, its job is to determine if a breakpoint has been reached, and +stop if so; read commands from the user, parse them, and execute +them, and hen send execution off to the next statement. + +Note that the order in which the commands are processed is very important; +some commands earlier in the loop will actually alter the C<$cmd> variable +to create other commands to be executed later. This is all highly I<optimized> +but can be confusing. Check the comments for each C<$cmd ... && do {}> to +see what's happening in any given command. + +=cut + +sub DB { + + # lock the debugger and get the thread id for the prompt + lock($DBGR); + my $tid; + if ($ENV{PERL5DB_THREADED}) { + $tid = eval { "[".threads->tid."]" }; + } + + # Check for whether we should be running continuously or not. + # _After_ the perl program is compiled, $single is set to 1: + if ( $single and not $second_time++ ) { + + # Options say run non-stop. Run until we get an interrupt. + if ($runnonstop) { # Disable until signal + # If there's any call stack in place, turn off single + # stepping into subs throughout the stack. + for ( $i = 0 ; $i <= $stack_depth ; ) { + $stack[ $i++ ] &= ~1; + } + + # And we are now no longer in single-step mode. + $single = 0; + + # If we simply returned at this point, we wouldn't get + # the trace info. Fall on through. + # return; + } ## end if ($runnonstop) + + elsif ($ImmediateStop) { + + # We are supposed to stop here; XXX probably a break. + $ImmediateStop = 0; # We've processed it; turn it off + $signal = 1; # Simulate an interrupt to force + # us into the command loop + } + } ## end if ($single and not $second_time... + + # If we're in single-step mode, or an interrupt (real or fake) + # has occurred, turn off non-stop mode. + $runnonstop = 0 if $single or $signal; + + # Preserve current values of $@, $!, $^E, $,, $/, $\, $^W. + # The code being debugged may have altered them. + &save; + + # Since DB::DB gets called after every line, we can use caller() to + # figure out where we last were executing. Sneaky, eh? This works because + # caller is returning all the extra information when called from the + # debugger. + local ( $package, $filename, $line ) = caller; + local $filename_ini = $filename; + + # set up the context for DB::eval, so it can properly execute + # code on behalf of the user. We add the package in so that the + # code is eval'ed in the proper package (not in the debugger!). + local $usercontext = + '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' . "package $package;"; + + # Create an alias to the active file magical array to simplify + # the code here. + local (*dbline) = $main::{ '_<' . $filename }; + + # we need to check for pseudofiles on Mac OS (these are files + # not attached to a filename, but instead stored in Dev:Pseudo) + if ( $^O eq 'MacOS' && $#dbline < 0 ) { + $filename_ini = $filename = 'Dev:Pseudo'; + *dbline = $main::{ '_<' . $filename }; + } + + # Last line in the program. + local $max = $#dbline; + + # if we have something here, see if we should break. + if ( $dbline{$line} + && ( ( $stop, $action ) = split( /\0/, $dbline{$line} ) ) ) + { + + # Stop if the stop criterion says to just stop. + if ( $stop eq '1' ) { + $signal |= 1; + } + + # It's a conditional stop; eval it in the user's context and + # see if we should stop. If so, remove the one-time sigil. + elsif ($stop) { + $evalarg = "\$DB::signal |= 1 if do {$stop}"; + &eval; + $dbline{$line} =~ s/;9($|\0)/$1/; + } + } ## end if ($dbline{$line} && ... + + # Preserve the current stop-or-not, and see if any of the W + # (watch expressions) has changed. + my $was_signal = $signal; + + # If we have any watch expressions ... + if ( $trace & 2 ) { + for ( my $n = 0 ; $n <= $#to_watch ; $n++ ) { + $evalarg = $to_watch[$n]; + local $onetimeDump; # Tell DB::eval() to not output results + + # Fix context DB::eval() wants to return an array, but + # we need a scalar here. + my ($val) = join( "', '", &eval ); + $val = ( ( defined $val ) ? "'$val'" : 'undef' ); + + # Did it change? + if ( $val ne $old_watch[$n] ) { + + # Yep! Show the difference, and fake an interrupt. + $signal = 1; + print $OUT <<EOP; +Watchpoint $n:\t$to_watch[$n] changed: + old value:\t$old_watch[$n] + new value:\t$val +EOP + $old_watch[$n] = $val; + } ## end if ($val ne $old_watch... + } ## end for (my $n = 0 ; $n <= ... + } ## end if ($trace & 2) + +=head2 C<watchfunction()> + +C<watchfunction()> is a function that can be defined by the user; it is a +function which will be run on each entry to C<DB::DB>; it gets the +current package, filename, and line as its parameters. + +The watchfunction can do anything it likes; it is executing in the +debugger's context, so it has access to all of the debugger's internal +data structures and functions. + +C<watchfunction()> can control the debugger's actions. Any of the following +will cause the debugger to return control to the user's program after +C<watchfunction()> executes: + +=over 4 + +=item * + +Returning a false value from the C<watchfunction()> itself. + +=item * + +Altering C<$single> to a false value. + +=item * + +Altering C<$signal> to a false value. + +=item * + +Turning off the C<4> bit in C<$trace> (this also disables the +check for C<watchfunction()>. This can be done with + + $trace &= ~4; + +=back + +=cut + + # If there's a user-defined DB::watchfunction, call it with the + # current package, filename, and line. The function executes in + # the DB:: package. + if ( $trace & 4 ) { # User-installed watch + return + if watchfunction( $package, $filename, $line ) + and not $single + and not $was_signal + and not( $trace & ~4 ); + } ## end if ($trace & 4) + + # Pick up any alteration to $signal in the watchfunction, and + # turn off the signal now. + $was_signal = $signal; + $signal = 0; + +=head2 GETTING READY TO EXECUTE COMMANDS + +The debugger decides to take control if single-step mode is on, the +C<t> command was entered, or the user generated a signal. If the program +has fallen off the end, we set things up so that entering further commands +won't cause trouble, and we say that the program is over. + +=cut + + # Check to see if we should grab control ($single true, + # trace set appropriately, or we got a signal). + if ( $single || ( $trace & 1 ) || $was_signal ) { + + # Yes, grab control. + if ($slave_editor) { + + # Tell the editor to update its position. + $position = "\032\032$filename:$line:0\n"; + print_lineinfo($position); + } + +=pod + +Special check: if we're in package C<DB::fake>, we've gone through the +C<END> block at least once. We set up everything so that we can continue +to enter commands and have a valid context to be in. + +=cut + + elsif ( $package eq 'DB::fake' ) { + + # Fallen off the end already. + $term || &setterm; + print_help(<<EOP); +Debugged program terminated. Use B<q> to quit or B<R> to restart, + use B<o> I<inhibit_exit> to avoid stopping after program termination, + B<h q>, B<h R> or B<h o> to get additional info. +EOP + + # Set the DB::eval context appropriately. + $package = 'main'; + $usercontext = + '($@, $!, $^E, $,, $/, $\, $^W) = @saved;' + . "package $package;"; # this won't let them modify, alas + } ## end elsif ($package eq 'DB::fake') + +=pod + +If the program hasn't finished executing, we scan forward to the +next executable line, print that out, build the prompt from the file and line +number information, and print that. + +=cut + + else { + + # Still somewhere in the midst of execution. Set up the + # debugger prompt. + $sub =~ s/\'/::/; # Swap Perl 4 package separators (') to + # Perl 5 ones (sorry, we don't print Klingon + #module names) + + $prefix = $sub =~ /::/ ? "" : "${'package'}::"; + $prefix .= "$sub($filename:"; + $after = ( $dbline[$line] =~ /\n$/ ? '' : "\n" ); + + # Break up the prompt if it's really long. + if ( length($prefix) > 30 ) { + $position = "$prefix$line):\n$line:\t$dbline[$line]$after"; + $prefix = ""; + $infix = ":\t"; + } + else { + $infix = "):\t"; + $position = "$prefix$line$infix$dbline[$line]$after"; + } + + # Print current line info, indenting if necessary. + if ($frame) { + print_lineinfo( ' ' x $stack_depth, + "$line:\t$dbline[$line]$after" ); + } + else { + print_lineinfo($position); + } + + # Scan forward, stopping at either the end or the next + # unbreakable line. + for ( $i = $line + 1 ; $i <= $max && $dbline[$i] == 0 ; ++$i ) + { #{ vi + + # Drop out on null statements, block closers, and comments. + last if $dbline[$i] =~ /^\s*[\;\}\#\n]/; + + # Drop out if the user interrupted us. + last if $signal; + + # Append a newline if the line doesn't have one. Can happen + # in eval'ed text, for instance. + $after = ( $dbline[$i] =~ /\n$/ ? '' : "\n" ); + + # Next executable line. + $incr_pos = "$prefix$i$infix$dbline[$i]$after"; + $position .= $incr_pos; + if ($frame) { + + # Print it indented if tracing is on. + print_lineinfo( ' ' x $stack_depth, + "$i:\t$dbline[$i]$after" ); + } + else { + print_lineinfo($incr_pos); + } + } ## end for ($i = $line + 1 ; $i... + } ## end else [ if ($slave_editor) + } ## end if ($single || ($trace... + +=pod + +If there's an action to be executed for the line we stopped at, execute it. +If there are any preprompt actions, execute those as well. + +=cut + + # If there's an action, do it now. + $evalarg = $action, &eval if $action; + + # Are we nested another level (e.g., did we evaluate a function + # that had a breakpoint in it at the debugger prompt)? + if ( $single || $was_signal ) { + + # Yes, go down a level. + local $level = $level + 1; + + # Do any pre-prompt actions. + foreach $evalarg (@$pre) { + &eval; + } + + # Complain about too much recursion if we passed the limit. + print $OUT $stack_depth . " levels deep in subroutine calls!\n" + if $single & 4; + + # The line we're currently on. Set $incr to -1 to stay here + # until we get a command that tells us to advance. + $start = $line; + $incr = -1; # for backward motion. + + # Tack preprompt debugger actions ahead of any actual input. + @typeahead = ( @$pretype, @typeahead ); + +=head2 WHERE ARE WE? + +XXX Relocate this section? + +The debugger normally shows the line corresponding to the current line of +execution. Sometimes, though, we want to see the next line, or to move elsewhere +in the file. This is done via the C<$incr>, C<$start>, and C<$max> variables. + +C<$incr> controls by how many lines the I<current> line should move forward +after a command is executed. If set to -1, this indicates that the I<current> +line shouldn't change. + +C<$start> is the I<current> line. It is used for things like knowing where to +move forwards or backwards from when doing an C<L> or C<-> command. + +C<$max> tells the debugger where the last line of the current file is. It's +used to terminate loops most often. + +=head2 THE COMMAND LOOP + +Most of C<DB::DB> is actually a command parsing and dispatch loop. It comes +in two parts: + +=over 4 + +=item * + +The outer part of the loop, starting at the C<CMD> label. This loop +reads a command and then executes it. + +=item * + +The inner part of the loop, starting at the C<PIPE> label. This part +is wholly contained inside the C<CMD> block and only executes a command. +Used to handle commands running inside a pager. + +=back + +So why have two labels to restart the loop? Because sometimes, it's easier to +have a command I<generate> another command and then re-execute the loop to do +the new command. This is faster, but perhaps a bit more convoluted. + +=cut + + # The big command dispatch loop. It keeps running until the + # user yields up control again. + # + # If we have a terminal for input, and we get something back + # from readline(), keep on processing. + CMD: + while ( + + # We have a terminal, or can get one ... + ( $term || &setterm ), + + # ... and it belogs to this PID or we get one for this PID ... + ( $term_pid == $$ or resetterm(1) ), + + # ... and we got a line of command input ... + defined( + $cmd = &readline( + "$pidprompt $tid DB" + . ( '<' x $level ) + . ( $#hist + 1 ) + . ( '>' x $level ) . " " + ) + ) + ) + { + + share($cmd); + # ... try to execute the input as debugger commands. + + # Don't stop running. + $single = 0; + + # No signal is active. + $signal = 0; + + # Handle continued commands (ending with \): + $cmd =~ s/\\$/\n/ && do { + $cmd .= &readline(" cont: "); + redo CMD; + }; + +=head4 The null command + +A newline entered by itself means I<re-execute the last command>. We grab the +command out of C<$laststep> (where it was recorded previously), and copy it +back into C<$cmd> to be executed below. If there wasn't any previous command, +we'll do nothing below (no command will match). If there was, we also save it +in the command history and fall through to allow the command parsing to pick +it up. + +=cut + + # Empty input means repeat the last command. + $cmd =~ /^$/ && ( $cmd = $laststep ); + chomp($cmd); # get rid of the annoying extra newline + push( @hist, $cmd ) if length($cmd) > 1; + push( @truehist, $cmd ); + share(@hist); + share(@truehist); + + # This is a restart point for commands that didn't arrive + # via direct user input. It allows us to 'redo PIPE' to + # re-execute command processing without reading a new command. + PIPE: { + $cmd =~ s/^\s+//s; # trim annoying leading whitespace + $cmd =~ s/\s+$//s; # trim annoying trailing whitespace + ($i) = split( /\s+/, $cmd ); + +=head3 COMMAND ALIASES + +The debugger can create aliases for commands (these are stored in the +C<%alias> hash). Before a command is executed, the command loop looks it up +in the alias hash and substitutes the contents of the alias for the command, +completely replacing it. + +=cut + + # See if there's an alias for the command, and set it up if so. + if ( $alias{$i} ) { + + # Squelch signal handling; we want to keep control here + # if something goes loco during the alias eval. + local $SIG{__DIE__}; + local $SIG{__WARN__}; + + # This is a command, so we eval it in the DEBUGGER's + # scope! Otherwise, we can't see the special debugger + # variables, or get to the debugger's subs. (Well, we + # _could_, but why make it even more complicated?) + eval "\$cmd =~ $alias{$i}"; + if ($@) { + local $\ = ''; + print $OUT "Couldn't evaluate `$i' alias: $@"; + next CMD; + } + } ## end if ($alias{$i}) + +=head3 MAIN-LINE COMMANDS + +All of these commands work up to and after the program being debugged has +terminated. + +=head4 C<q> - quit + +Quit the debugger. This entails setting the C<$fall_off_end> flag, so we don't +try to execute further, cleaning any restart-related stuff out of the +environment, and executing with the last value of C<$?>. + +=cut + + $cmd =~ /^q$/ && do { + $fall_off_end = 1; + clean_ENV(); + exit $?; + }; + +=head4 C<t> - trace + +Turn tracing on or off. Inverts the appropriate bit in C<$trace> (q.v.). + +=cut + + $cmd =~ /^t$/ && do { + $trace ^= 1; + local $\ = ''; + print $OUT "Trace = " + . ( ( $trace & 1 ) ? "on" : "off" ) . "\n"; + next CMD; + }; + +=head4 C<S> - list subroutines matching/not matching a pattern + +Walks through C<%sub>, checking to see whether or not to print the name. + +=cut + + $cmd =~ /^S(\s+(!)?(.+))?$/ && do { + + $Srev = defined $2; # Reverse scan? + $Spatt = $3; # The pattern (if any) to use. + $Snocheck = !defined $1; # No args - print all subs. + + # Need to make these sane here. + local $\ = ''; + local $, = ''; + + # Search through the debugger's magical hash of subs. + # If $nocheck is true, just print the sub name. + # Otherwise, check it against the pattern. We then use + # the XOR trick to reverse the condition as required. + foreach $subname ( sort( keys %sub ) ) { + if ( $Snocheck or $Srev ^ ( $subname =~ /$Spatt/ ) ) { + print $OUT $subname, "\n"; + } + } + next CMD; + }; + +=head4 C<X> - list variables in current package + +Since the C<V> command actually processes this, just change this to the +appropriate C<V> command and fall through. + +=cut + + $cmd =~ s/^X\b/V $package/; + +=head4 C<V> - list variables + +Uses C<dumpvar.pl> to dump out the current values for selected variables. + +=cut + + # Bare V commands get the currently-being-debugged package + # added. + $cmd =~ /^V$/ && do { + $cmd = "V $package"; + }; + + # V - show variables in package. + $cmd =~ /^V\b\s*(\S+)\s*(.*)/ && do { + + # Save the currently selected filehandle and + # force output to debugger's filehandle (dumpvar + # just does "print" for output). + local ($savout) = select($OUT); + + # Grab package name and variables to dump. + $packname = $1; + @vars = split( ' ', $2 ); + + # If main::dumpvar isn't here, get it. + do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; + if ( defined &main::dumpvar ) { + + # We got it. Turn off subroutine entry/exit messages + # for the moment, along with return values. + local $frame = 0; + local $doret = -2; + + # must detect sigpipe failures - not catching + # then will cause the debugger to die. + eval { + &main::dumpvar( + $packname, + defined $option{dumpDepth} + ? $option{dumpDepth} + : -1, # assume -1 unless specified + @vars + ); + }; + + # The die doesn't need to include the $@, because + # it will automatically get propagated for us. + if ($@) { + die unless $@ =~ /dumpvar print failed/; + } + } ## end if (defined &main::dumpvar) + else { + + # Couldn't load dumpvar. + print $OUT "dumpvar.pl not available.\n"; + } + + # Restore the output filehandle, and go round again. + select($savout); + next CMD; + }; + +=head4 C<x> - evaluate and print an expression + +Hands the expression off to C<DB::eval>, setting it up to print the value +via C<dumpvar.pl> instead of just printing it directly. + +=cut + + $cmd =~ s/^x\b/ / && do { # Remainder gets done by DB::eval() + $onetimeDump = 'dump'; # main::dumpvar shows the output + + # handle special "x 3 blah" syntax XXX propagate + # doc back to special variables. + if ( $cmd =~ s/^\s*(\d+)(?=\s)/ / ) { + $onetimedumpDepth = $1; + } + }; + +=head4 C<m> - print methods + +Just uses C<DB::methods> to determine what methods are available. + +=cut + + $cmd =~ s/^m\s+([\w:]+)\s*$/ / && do { + methods($1); + next CMD; + }; + + # m expr - set up DB::eval to do the work + $cmd =~ s/^m\b/ / && do { # Rest gets done by DB::eval() + $onetimeDump = 'methods'; # method output gets used there + }; + +=head4 C<f> - switch files + +=cut + + $cmd =~ /^f\b\s*(.*)/ && do { + $file = $1; + $file =~ s/\s+$//; + + # help for no arguments (old-style was return from sub). + if ( !$file ) { + print $OUT + "The old f command is now the r command.\n"; # hint + print $OUT "The new f command switches filenames.\n"; + next CMD; + } ## end if (!$file) + + # if not in magic file list, try a close match. + if ( !defined $main::{ '_<' . $file } ) { + if ( ($try) = grep( m#^_<.*$file#, keys %main:: ) ) { + { + $try = substr( $try, 2 ); + print $OUT "Choosing $try matching `$file':\n"; + $file = $try; + } + } ## end if (($try) = grep(m#^_<.*$file#... + } ## end if (!defined $main::{ ... + + # If not successfully switched now, we failed. + if ( !defined $main::{ '_<' . $file } ) { + print $OUT "No file matching `$file' is loaded.\n"; + next CMD; + } + + # We switched, so switch the debugger internals around. + elsif ( $file ne $filename ) { + *dbline = $main::{ '_<' . $file }; + $max = $#dbline; + $filename = $file; + $start = 1; + $cmd = "l"; + } ## end elsif ($file ne $filename) + + # We didn't switch; say we didn't. + else { + print $OUT "Already in $file.\n"; + next CMD; + } + }; + +=head4 C<.> - return to last-executed line. + +We set C<$incr> to -1 to indicate that the debugger shouldn't move ahead, +and then we look up the line in the magical C<%dbline> hash. + +=cut + + # . command. + $cmd =~ /^\.$/ && do { + $incr = -1; # stay at current line + + # Reset everything to the old location. + $start = $line; + $filename = $filename_ini; + *dbline = $main::{ '_<' . $filename }; + $max = $#dbline; + + # Now where are we? + print_lineinfo($position); + next CMD; + }; + +=head4 C<-> - back one window + +We change C<$start> to be one window back; if we go back past the first line, +we set it to be the first line. We ser C<$incr> to put us back at the +currently-executing line, and then put a C<l $start +> (list one window from +C<$start>) in C<$cmd> to be executed later. + +=cut + + # - - back a window. + $cmd =~ /^-$/ && do { + + # back up by a window; go to 1 if back too far. + $start -= $incr + $window + 1; + $start = 1 if $start <= 0; + $incr = $window - 1; + + # Generate and execute a "l +" command (handled below). + $cmd = 'l ' . ($start) . '+'; + }; + +=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>, {, {{> + +In Perl 5.8.0, a realignment of the commands was done to fix up a number of +problems, most notably that the default case of several commands destroying +the user's work in setting watchpoints, actions, etc. We wanted, however, to +retain the old commands for those who were used to using them or who preferred +them. At this point, we check for the new commands and call C<cmd_wrapper> to +deal with them instead of processing them in-line. + +=cut + + # All of these commands were remapped in perl 5.8.0; + # we send them off to the secondary dispatcher (see below). + $cmd =~ /^([aAbBeEhilLMoOPvwW]\b|[<>\{]{1,2})\s*(.*)/so && do { + &cmd_wrapper( $1, $2, $line ); + next CMD; + }; + +=head4 C<y> - List lexicals in higher scope + +Uses C<PadWalker> to find the lexicals supplied as arguments in a scope +above the current one and then displays then using C<dumpvar.pl>. + +=cut + + $cmd =~ /^y(?:\s+(\d*)\s*(.*))?$/ && do { + + # See if we've got the necessary support. + eval { require PadWalker; PadWalker->VERSION(0.08) } + or &warn( + $@ =~ /locate/ + ? "PadWalker module not found - please install\n" + : $@ + ) + and next CMD; + + # Load up dumpvar if we don't have it. If we can, that is. + do 'dumpvar.pl' || die $@ unless defined &main::dumpvar; + defined &main::dumpvar + or print $OUT "dumpvar.pl not available.\n" + and next CMD; + + # Got all the modules we need. Find them and print them. + my @vars = split( ' ', $2 || '' ); + + # Find the pad. + my $h = eval { PadWalker::peek_my( ( $1 || 0 ) + 1 ) }; + + # Oops. Can't find it. + $@ and $@ =~ s/ at .*//, &warn($@), next CMD; + + # Show the desired vars with dumplex(). + my $savout = select($OUT); + + # Have dumplex dump the lexicals. + dumpvar::dumplex( $_, $h->{$_}, + defined $option{dumpDepth} ? $option{dumpDepth} : -1, + @vars ) + for sort keys %$h; + select($savout); + next CMD; + }; + +=head3 COMMANDS NOT WORKING AFTER PROGRAM ENDS + +All of the commands below this point don't work after the program being +debugged has ended. All of them check to see if the program has ended; this +allows the commands to be relocated without worrying about a 'line of +demarcation' above which commands can be entered anytime, and below which +they can't. + +=head4 C<n> - single step, but don't trace down into subs + +Done by setting C<$single> to 2, which forces subs to execute straight through +when entered (see C<DB::sub>). We also save the C<n> command in C<$laststep>, +so a null command knows what to re-execute. + +=cut + + # n - next + $cmd =~ /^n$/ && do { + end_report(), next CMD if $finished and $level <= 1; + + # Single step, but don't enter subs. + $single = 2; + + # Save for empty command (repeat last). + $laststep = $cmd; + last CMD; + }; + +=head4 C<s> - single-step, entering subs + +Sets C<$single> to 1, which causes C<DB::sub> to continue tracing inside +subs. Also saves C<s> as C<$lastcmd>. + +=cut + + # s - single step. + $cmd =~ /^s$/ && do { + + # Get out and restart the command loop if program + # has finished. + end_report(), next CMD if $finished and $level <= 1; + + # Single step should enter subs. + $single = 1; + + # Save for empty command (repeat last). + $laststep = $cmd; + last CMD; + }; + +=head4 C<c> - run continuously, setting an optional breakpoint + +Most of the code for this command is taken up with locating the optional +breakpoint, which is either a subroutine name or a line number. We set +the appropriate one-time-break in C<@dbline> and then turn off single-stepping +in this and all call levels above this one. + +=cut + + # c - start continuous execution. + $cmd =~ /^c\b\s*([\w:]*)\s*$/ && do { + + # Hey, show's over. The debugged program finished + # executing already. + end_report(), next CMD if $finished and $level <= 1; + + # Capture the place to put a one-time break. + $subname = $i = $1; + + # Probably not needed, since we finish an interactive + # sub-session anyway... + # local $filename = $filename; + # local *dbline = *dbline; # XXX Would this work?! + # + # The above question wonders if localizing the alias + # to the magic array works or not. Since it's commented + # out, we'll just leave that to speculation for now. + + # If the "subname" isn't all digits, we'll assume it + # is a subroutine name, and try to find it. + if ( $subname =~ /\D/ ) { # subroutine name + # Qualify it to the current package unless it's + # already qualified. + $subname = $package . "::" . $subname + unless $subname =~ /::/; + + # find_sub will return "file:line_number" corresponding + # to where the subroutine is defined; we call find_sub, + # break up the return value, and assign it in one + # operation. + ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(.*)$/ ); + + # Force the line number to be numeric. + $i += 0; + + # If we got a line number, we found the sub. + if ($i) { + + # Switch all the debugger's internals around so + # we're actually working with that file. + $filename = $file; + *dbline = $main::{ '_<' . $filename }; + + # Mark that there's a breakpoint in this file. + $had_breakpoints{$filename} |= 1; + + # Scan forward to the first executable line + # after the 'sub whatever' line. + $max = $#dbline; + ++$i while $dbline[$i] == 0 && $i < $max; + } ## end if ($i) + + # We didn't find a sub by that name. + else { + print $OUT "Subroutine $subname not found.\n"; + next CMD; + } + } ## end if ($subname =~ /\D/) + + # At this point, either the subname was all digits (an + # absolute line-break request) or we've scanned through + # the code following the definition of the sub, looking + # for an executable, which we may or may not have found. + # + # If $i (which we set $subname from) is non-zero, we + # got a request to break at some line somewhere. On + # one hand, if there wasn't any real subroutine name + # involved, this will be a request to break in the current + # file at the specified line, so we have to check to make + # sure that the line specified really is breakable. + # + # On the other hand, if there was a subname supplied, the + # preceding block has moved us to the proper file and + # location within that file, and then scanned forward + # looking for the next executable line. We have to make + # sure that one was found. + # + # On the gripping hand, we can't do anything unless the + # current value of $i points to a valid breakable line. + # Check that. + if ($i) { + + # Breakable? + if ( $dbline[$i] == 0 ) { + print $OUT "Line $i not breakable.\n"; + next CMD; + } + + # Yes. Set up the one-time-break sigil. + $dbline{$i} =~ s/($|\0)/;9$1/; # add one-time-only b.p. + } ## end if ($i) + + # Turn off stack tracing from here up. + for ( $i = 0 ; $i <= $stack_depth ; ) { + $stack[ $i++ ] &= ~1; + } + last CMD; + }; + +=head4 C<r> - return from a subroutine + +For C<r> to work properly, the debugger has to stop execution again +immediately after the return is executed. This is done by forcing +single-stepping to be on in the call level above the current one. If +we are printing return values when a C<r> is executed, set C<$doret> +appropriately, and force us out of the command loop. + +=cut + + # r - return from the current subroutine. + $cmd =~ /^r$/ && do { + + # Can't do anythign if the program's over. + end_report(), next CMD if $finished and $level <= 1; + + # Turn on stack trace. + $stack[$stack_depth] |= 1; + + # Print return value unless the stack is empty. + $doret = $option{PrintRet} ? $stack_depth - 1 : -2; + last CMD; + }; + +=head4 C<T> - stack trace + +Just calls C<DB::print_trace>. + +=cut + + $cmd =~ /^T$/ && do { + print_trace( $OUT, 1 ); # skip DB + next CMD; + }; + +=head4 C<w> - List window around current line. + +Just calls C<DB::cmd_w>. + +=cut + + $cmd =~ /^w\b\s*(.*)/s && do { &cmd_w( 'w', $1 ); next CMD; }; + +=head4 C<W> - watch-expression processing. + +Just calls C<DB::cmd_W>. + +=cut + + $cmd =~ /^W\b\s*(.*)/s && do { &cmd_W( 'W', $1 ); next CMD; }; + +=head4 C</> - search forward for a string in the source + +We take the argument and treat it as a pattern. If it turns out to be a +bad one, we return the error we got from trying to C<eval> it and exit. +If not, we create some code to do the search and C<eval> it so it can't +mess us up. + +=cut + + $cmd =~ /^\/(.*)$/ && do { + + # The pattern as a string. + $inpat = $1; + + # Remove the final slash. + $inpat =~ s:([^\\])/$:$1:; + + # If the pattern isn't null ... + if ( $inpat ne "" ) { + + # Turn of warn and die procesing for a bit. + local $SIG{__DIE__}; + local $SIG{__WARN__}; + + # Create the pattern. + eval '$inpat =~ m' . "\a$inpat\a"; + if ( $@ ne "" ) { + + # Oops. Bad pattern. No biscuit. + # Print the eval error and go back for more + # commands. + print $OUT "$@"; + next CMD; + } + $pat = $inpat; + } ## end if ($inpat ne "") + + # Set up to stop on wrap-around. + $end = $start; + + # Don't move off the current line. + $incr = -1; + + # Done in eval so nothing breaks if the pattern + # does something weird. + eval ' + for (;;) { + # Move ahead one line. + ++$start; + + # Wrap if we pass the last line. + $start = 1 if ($start > $max); + + # Stop if we have gotten back to this line again, + last if ($start == $end); + + # A hit! (Note, though, that we are doing + # case-insensitive matching. Maybe a qr// + # expression would be better, so the user could + # do case-sensitive matching if desired. + if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) { + if ($slave_editor) { + # Handle proper escaping in the slave. + print $OUT "\032\032$filename:$start:0\n"; + } + else { + # Just print the line normally. + print $OUT "$start:\t",$dbline[$start],"\n"; + } + # And quit since we found something. + last; + } + } '; + + # If we wrapped, there never was a match. + print $OUT "/$pat/: not found\n" if ( $start == $end ); + next CMD; + }; + +=head4 C<?> - search backward for a string in the source + +Same as for C</>, except the loop runs backwards. + +=cut + + # ? - backward pattern search. + $cmd =~ /^\?(.*)$/ && do { + + # Get the pattern, remove trailing question mark. + $inpat = $1; + $inpat =~ s:([^\\])\?$:$1:; + + # If we've got one ... + if ( $inpat ne "" ) { + + # Turn off die & warn handlers. + local $SIG{__DIE__}; + local $SIG{__WARN__}; + eval '$inpat =~ m' . "\a$inpat\a"; + + if ( $@ ne "" ) { + + # Ouch. Not good. Print the error. + print $OUT $@; + next CMD; + } + $pat = $inpat; + } ## end if ($inpat ne "") + + # Where we are now is where to stop after wraparound. + $end = $start; + + # Don't move away from this line. + $incr = -1; + + # Search inside the eval to prevent pattern badness + # from killing us. + eval ' + for (;;) { + # Back up a line. + --$start; + + # Wrap if we pass the first line. + + $start = $max if ($start <= 0); + + # Quit if we get back where we started, + last if ($start == $end); + + # Match? + if ($dbline[$start] =~ m' . "\a$pat\a" . 'i) { + if ($slave_editor) { + # Yep, follow slave editor requirements. + print $OUT "\032\032$filename:$start:0\n"; + } + else { + # Yep, just print normally. + print $OUT "$start:\t",$dbline[$start],"\n"; + } + + # Found, so done. + last; + } + } '; + + # Say we failed if the loop never found anything, + print $OUT "?$pat?: not found\n" if ( $start == $end ); + next CMD; + }; + +=head4 C<$rc> - Recall command + +Manages the commands in C<@hist> (which is created if C<Term::ReadLine> reports +that the terminal supports history). It find the the command required, puts it +into C<$cmd>, and redoes the loop to execute it. + +=cut + + # $rc - recall command. + $cmd =~ /^$rc+\s*(-)?(\d+)?$/ && do { + + # No arguments, take one thing off history. + pop(@hist) if length($cmd) > 1; + + # Relative (- found)? + # Y - index back from most recent (by 1 if bare minus) + # N - go to that particular command slot or the last + # thing if nothing following. + $i = $1 ? ( $#hist - ( $2 || 1 ) ) : ( $2 || $#hist ); + + # Pick out the command desired. + $cmd = $hist[$i]; + + # Print the command to be executed and restart the loop + # with that command in the buffer. + print $OUT $cmd, "\n"; + redo CMD; + }; + +=head4 C<$sh$sh> - C<system()> command + +Calls the C<DB::system()> to handle the command. This keeps the C<STDIN> and +C<STDOUT> from getting messed up. + +=cut + + # $sh$sh - run a shell command (if it's all ASCII). + # Can't run shell commands with Unicode in the debugger, hmm. + $cmd =~ /^$sh$sh\s*([\x00-\xff]*)/ && do { + + # System it. + &system($1); + next CMD; + }; + +=head4 C<$rc I<pattern> $rc> - Search command history + +Another command to manipulate C<@hist>: this one searches it with a pattern. +If a command is found, it is placed in C<$cmd> and executed via C<redo>. + +=cut + + # $rc pattern $rc - find a command in the history. + $cmd =~ /^$rc([^$rc].*)$/ && do { + + # Create the pattern to use. + $pat = "^$1"; + + # Toss off last entry if length is >1 (and it always is). + pop(@hist) if length($cmd) > 1; + + # Look backward through the history. + for ( $i = $#hist ; $i ; --$i ) { + + # Stop if we find it. + last if $hist[$i] =~ /$pat/; + } + + if ( !$i ) { + + # Never found it. + print $OUT "No such command!\n\n"; + next CMD; + } + + # Found it. Put it in the buffer, print it, and process it. + $cmd = $hist[$i]; + print $OUT $cmd, "\n"; + redo CMD; + }; + +=head4 C<$sh> - Invoke a shell + +Uses C<DB::system> to invoke a shell. + +=cut + + # $sh - start a shell. + $cmd =~ /^$sh$/ && do { + + # Run the user's shell. If none defined, run Bourne. + # We resume execution when the shell terminates. + &system( $ENV{SHELL} || "/bin/sh" ); + next CMD; + }; + +=head4 C<$sh I<command>> - Force execution of a command in a shell + +Like the above, but the command is passed to the shell. Again, we use +C<DB::system> to avoid problems with C<STDIN> and C<STDOUT>. + +=cut + + # $sh command - start a shell and run a command in it. + $cmd =~ /^$sh\s*([\x00-\xff]*)/ && do { + + # XXX: using csh or tcsh destroys sigint retvals! + #&system($1); # use this instead + + # use the user's shell, or Bourne if none defined. + &system( $ENV{SHELL} || "/bin/sh", "-c", $1 ); + next CMD; + }; + +=head4 C<H> - display commands in history + +Prints the contents of C<@hist> (if any). + +=cut + + $cmd =~ /^H\b\s*\*/ && do { + @hist = @truehist = (); + print $OUT "History cleansed\n"; + next CMD; + }; + + $cmd =~ /^H\b\s*(-(\d+))?/ && do { + + # Anything other than negative numbers is ignored by + # the (incorrect) pattern, so this test does nothing. + $end = $2 ? ( $#hist - $2 ) : 0; + + # Set to the minimum if less than zero. + $hist = 0 if $hist < 0; + + # Start at the end of the array. + # Stay in while we're still above the ending value. + # Tick back by one each time around the loop. + for ( $i = $#hist ; $i > $end ; $i-- ) { + + # Print the command unless it has no arguments. + print $OUT "$i: ", $hist[$i], "\n" + unless $hist[$i] =~ /^.?$/; + } + next CMD; + }; + +=head4 C<man, doc, perldoc> - look up documentation + +Just calls C<runman()> to print the appropriate document. + +=cut + + # man, perldoc, doc - show manual pages. + $cmd =~ /^(?:man|(?:perl)?doc)\b(?:\s+([^(]*))?$/ && do { + runman($1); + next CMD; + }; + +=head4 C<p> - print + +Builds a C<print EXPR> expression in the C<$cmd>; this will get executed at +the bottom of the loop. + +=cut + + # p - print (no args): print $_. + $cmd =~ s/^p$/print {\$DB::OUT} \$_/; + + # p - print the given expression. + $cmd =~ s/^p\b/print {\$DB::OUT} /; + +=head4 C<=> - define command alias + +Manipulates C<%alias> to add or list command aliases. + +=cut + + # = - set up a command alias. + $cmd =~ s/^=\s*// && do { + my @keys; + if ( length $cmd == 0 ) { + + # No args, get current aliases. + @keys = sort keys %alias; + } + elsif ( my ( $k, $v ) = ( $cmd =~ /^(\S+)\s+(\S.*)/ ) ) { + + # Creating a new alias. $k is alias name, $v is + # alias value. + + # can't use $_ or kill //g state + for my $x ( $k, $v ) { + + # Escape "alarm" characters. + $x =~ s/\a/\\a/g; + } + + # Substitute key for value, using alarm chars + # as separators (which is why we escaped them in + # the command). + $alias{$k} = "s\a$k\a$v\a"; + + # Turn off standard warn and die behavior. + local $SIG{__DIE__}; + local $SIG{__WARN__}; + + # Is it valid Perl? + unless ( eval "sub { s\a$k\a$v\a }; 1" ) { + + # Nope. Bad alias. Say so and get out. + print $OUT "Can't alias $k to $v: $@\n"; + delete $alias{$k}; + next CMD; + } + + # We'll only list the new one. + @keys = ($k); + } ## end elsif (my ($k, $v) = ($cmd... + + # The argument is the alias to list. + else { + @keys = ($cmd); + } + + # List aliases. + for my $k (@keys) { + + # Messy metaquoting: Trim the substiution code off. + # We use control-G as the delimiter because it's not + # likely to appear in the alias. + if ( ( my $v = $alias{$k} ) =~ ss\a$k\a(.*)\a$1 ) { + + # Print the alias. + print $OUT "$k\t= $1\n"; + } + elsif ( defined $alias{$k} ) { + + # Couldn't trim it off; just print the alias code. + print $OUT "$k\t$alias{$k}\n"; + } + else { + + # No such, dude. + print "No alias for $k\n"; + } + } ## end for my $k (@keys) + next CMD; + }; + +=head4 C<source> - read commands from a file. + +Opens a lexical filehandle and stacks it on C<@cmdfhs>; C<DB::readline> will +pick it up. + +=cut + + # source - read commands from a file (or pipe!) and execute. + $cmd =~ /^source\s+(.*\S)/ && do { + if ( open my $fh, $1 ) { + + # Opened OK; stick it in the list of file handles. + push @cmdfhs, $fh; + } + else { + + # Couldn't open it. + &warn("Can't execute `$1': $!\n"); + } + next CMD; + }; + +=head4 C<save> - send current history to a file + +Takes the complete history, (not the shrunken version you see with C<H>), +and saves it to the given filename, so it can be replayed using C<source>. + +Note that all C<^(save|source)>'s are commented out with a view to minimise recursion. + +=cut + + # save source - write commands to a file for later use + $cmd =~ /^save\s*(.*)$/ && do { + my $file = $1 || '.perl5dbrc'; # default? + if ( open my $fh, "> $file" ) { + + # chomp to remove extraneous newlines from source'd files + chomp( my @truelist = + map { m/^\s*(save|source)/ ? "#$_" : $_ } + @truehist ); + print $fh join( "\n", @truelist ); + print "commands saved in $file\n"; + } + else { + &warn("Can't save debugger commands in '$1': $!\n"); + } + next CMD; + }; + +=head4 C<R> - restart + +Restart the debugger session. + +=head4 C<rerun> - rerun the current session + +Return to any given position in the B<true>-history list + +=cut + + # R - restart execution. + # rerun - controlled restart execution. + $cmd =~ /^(R|rerun\s*(.*))$/ && do { + my @args = ($1 eq 'R' ? restart() : rerun($2)); + + # Close all non-system fds for a clean restart. A more + # correct method would be to close all fds that were not + # open when the process started, but this seems to be + # hard. See "debugger 'R'estart and open database + # connections" on p5p. + + my $max_fd = 1024; # default if POSIX can't be loaded + if (eval { require POSIX }) { + $max_fd = POSIX::sysconf(POSIX::_SC_OPEN_MAX()); + } + + if (defined $max_fd) { + foreach ($^F+1 .. $max_fd-1) { + next unless open FD_TO_CLOSE, "<&=$_"; + close(FD_TO_CLOSE); + } + } + + # And run Perl again. We use exec() to keep the + # PID stable (and that way $ini_pids is still valid). + exec(@args) || print $OUT "exec failed: $!\n"; + + last CMD; + }; + +=head4 C<|, ||> - pipe output through the pager. + +For C<|>, we save C<OUT> (the debugger's output filehandle) and C<STDOUT> +(the program's standard output). For C<||>, we only save C<OUT>. We open a +pipe to the pager (restoring the output filehandles if this fails). If this +is the C<|> command, we also set up a C<SIGPIPE> handler which will simply +set C<$signal>, sending us back into the debugger. + +We then trim off the pipe symbols and C<redo> the command loop at the +C<PIPE> label, causing us to evaluate the command in C<$cmd> without +reading another. + +=cut + + # || - run command in the pager, with output to DB::OUT. + $cmd =~ /^\|\|?\s*[^|]/ && do { + if ( $pager =~ /^\|/ ) { + + # Default pager is into a pipe. Redirect I/O. + open( SAVEOUT, ">&STDOUT" ) + || &warn("Can't save STDOUT"); + open( STDOUT, ">&OUT" ) + || &warn("Can't redirect STDOUT"); + } ## end if ($pager =~ /^\|/) + else { + + # Not into a pipe. STDOUT is safe. + open( SAVEOUT, ">&OUT" ) || &warn("Can't save DB::OUT"); + } + + # Fix up environment to record we have less if so. + fix_less(); + + unless ( $piped = open( OUT, $pager ) ) { + + # Couldn't open pipe to pager. + &warn("Can't pipe output to `$pager'"); + if ( $pager =~ /^\|/ ) { + + # Redirect I/O back again. + open( OUT, ">&STDOUT" ) # XXX: lost message + || &warn("Can't restore DB::OUT"); + open( STDOUT, ">&SAVEOUT" ) + || &warn("Can't restore STDOUT"); + close(SAVEOUT); + } ## end if ($pager =~ /^\|/) + else { + + # Redirect I/O. STDOUT already safe. + open( OUT, ">&STDOUT" ) # XXX: lost message + || &warn("Can't restore DB::OUT"); + } + next CMD; + } ## end unless ($piped = open(OUT,... + + # Set up broken-pipe handler if necessary. + $SIG{PIPE} = \&DB::catch + if $pager =~ /^\|/ + && ( "" eq $SIG{PIPE} || "DEFAULT" eq $SIG{PIPE} ); + + # Save current filehandle, unbuffer out, and put it back. + $selected = select(OUT); + $| = 1; + + # Don't put it back if pager was a pipe. + select($selected), $selected = "" unless $cmd =~ /^\|\|/; + + # Trim off the pipe symbols and run the command now. + $cmd =~ s/^\|+\s*//; + redo PIPE; + }; + +=head3 END OF COMMAND PARSING + +Anything left in C<$cmd> at this point is a Perl expression that we want to +evaluate. We'll always evaluate in the user's context, and fully qualify +any variables we might want to address in the C<DB> package. + +=cut + + # t - turn trace on. + $cmd =~ s/^t\s/\$DB::trace |= 1;\n/; + + # s - single-step. Remember the last command was 's'. + $cmd =~ s/^s\s/\$DB::single = 1;\n/ && do { $laststep = 's' }; + + # n - single-step, but not into subs. Remember last command + # was 'n'. + $cmd =~ s/^n\s/\$DB::single = 2;\n/ && do { $laststep = 'n' }; + + } # PIPE: + + # Make sure the flag that says "the debugger's running" is + # still on, to make sure we get control again. + $evalarg = "\$^D = \$^D | \$DB::db_stop;\n$cmd"; + + # Run *our* eval that executes in the caller's context. + &eval; + + # Turn off the one-time-dump stuff now. + if ($onetimeDump) { + $onetimeDump = undef; + $onetimedumpDepth = undef; + } + elsif ( $term_pid == $$ ) { + eval { # May run under miniperl, when not available... + STDOUT->flush(); + STDERR->flush(); + }; + + # XXX If this is the master pid, print a newline. + print $OUT "\n"; + } + } ## end while (($term || &setterm... + +=head3 POST-COMMAND PROCESSING + +After each command, we check to see if the command output was piped anywhere. +If so, we go through the necessary code to unhook the pipe and go back to +our standard filehandles for input and output. + +=cut + + continue { # CMD: + + # At the end of every command: + if ($piped) { + + # Unhook the pipe mechanism now. + if ( $pager =~ /^\|/ ) { + + # No error from the child. + $? = 0; + + # we cannot warn here: the handle is missing --tchrist + close(OUT) || print SAVEOUT "\nCan't close DB::OUT\n"; + + # most of the $? crud was coping with broken cshisms + # $? is explicitly set to 0, so this never runs. + if ($?) { + print SAVEOUT "Pager `$pager' failed: "; + if ( $? == -1 ) { + print SAVEOUT "shell returned -1\n"; + } + elsif ( $? >> 8 ) { + print SAVEOUT ( $? & 127 ) + ? " (SIG#" . ( $? & 127 ) . ")" + : "", ( $? & 128 ) ? " -- core dumped" : "", "\n"; + } + else { + print SAVEOUT "status ", ( $? >> 8 ), "\n"; + } + } ## end if ($?) + + # Reopen filehandle for our output (if we can) and + # restore STDOUT (if we can). + open( OUT, ">&STDOUT" ) || &warn("Can't restore DB::OUT"); + open( STDOUT, ">&SAVEOUT" ) + || &warn("Can't restore STDOUT"); + + # Turn off pipe exception handler if necessary. + $SIG{PIPE} = "DEFAULT" if $SIG{PIPE} eq \&DB::catch; + + # Will stop ignoring SIGPIPE if done like nohup(1) + # does SIGINT but Perl doesn't give us a choice. + } ## end if ($pager =~ /^\|/) + else { + + # Non-piped "pager". Just restore STDOUT. + open( OUT, ">&SAVEOUT" ) || &warn("Can't restore DB::OUT"); + } + + # Close filehandle pager was using, restore the normal one + # if necessary, + close(SAVEOUT); + select($selected), $selected = "" unless $selected eq ""; + + # No pipes now. + $piped = ""; + } ## end if ($piped) + } # CMD: + +=head3 COMMAND LOOP TERMINATION + +When commands have finished executing, we come here. If the user closed the +input filehandle, we turn on C<$fall_off_end> to emulate a C<q> command. We +evaluate any post-prompt items. We restore C<$@>, C<$!>, C<$^E>, C<$,>, C<$/>, +C<$\>, and C<$^W>, and return a null list as expected by the Perl interpreter. +The interpreter will then execute the next line and then return control to us +again. + +=cut + + # No more commands? Quit. + $fall_off_end = 1 unless defined $cmd; # Emulate `q' on EOF + + # Evaluate post-prompt commands. + foreach $evalarg (@$post) { + &eval; + } + } # if ($single || $signal) + + # Put the user's globals back where you found them. + ( $@, $!, $^E, $,, $/, $\, $^W ) = @saved; + (); +} ## end sub DB + +# The following code may be executed now: +# BEGIN {warn 4} + +=head2 sub + +C<sub> is called whenever a subroutine call happens in the program being +debugged. The variable C<$DB::sub> contains the name of the subroutine +being called. + +The core function of this subroutine is to actually call the sub in the proper +context, capturing its output. This of course causes C<DB::DB> to get called +again, repeating until the subroutine ends and returns control to C<DB::sub> +again. Once control returns, C<DB::sub> figures out whether or not to dump the +return value, and returns its captured copy of the return value as its own +return value. The value then feeds back into the program being debugged as if +C<DB::sub> hadn't been there at all. + +C<sub> does all the work of printing the subroutine entry and exit messages +enabled by setting C<$frame>. It notes what sub the autoloader got called for, +and also prints the return value if needed (for the C<r> command and if +the 16 bit is set in C<$frame>). + +It also tracks the subroutine call depth by saving the current setting of +C<$single> in the C<@stack> package global; if this exceeds the value in +C<$deep>, C<sub> automatically turns on printing of the current depth by +setting the C<4> bit in C<$single>. In any case, it keeps the current setting +of stop/don't stop on entry to subs set as it currently is set. + +=head3 C<caller()> support + +If C<caller()> is called from the package C<DB>, it provides some +additional data, in the following order: + +=over 4 + +=item * C<$package> + +The package name the sub was in + +=item * C<$filename> + +The filename it was defined in + +=item * C<$line> + +The line number it was defined on + +=item * C<$subroutine> + +The subroutine name; C<(eval)> if an C<eval>(). + +=item * C<$hasargs> + +1 if it has arguments, 0 if not + +=item * C<$wantarray> + +1 if array context, 0 if scalar context + +=item * C<$evaltext> + +The C<eval>() text, if any (undefined for C<eval BLOCK>) + +=item * C<$is_require> + +frame was created by a C<use> or C<require> statement + +=item * C<$hints> + +pragma information; subject to change between versions + +=item * C<$bitmask> + +pragma information; subject to change between versions + +=item * C<@DB::args> + +arguments with which the subroutine was invoked + +=back + +=cut + +sub sub { + # Do not use a regex in this subroutine -> results in corrupted memory + # See: [perl #66110] + + # lock ourselves under threads + lock($DBGR); + + # Whether or not the autoloader was running, a scalar to put the + # sub's return value in (if needed), and an array to put the sub's + # return value in (if needed). + my ( $al, $ret, @ret ) = ""; + if ($sub eq 'threads::new' && $ENV{PERL5DB_THREADED}) { + print "creating new thread\n"; + } + + # If the last ten characters are '::AUTOLOAD', note we've traced + # into AUTOLOAD for $sub. + if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { + $al = " for $$sub" if defined $$sub; + } + + # We stack the stack pointer and then increment it to protect us + # from a situation that might unwind a whole bunch of call frames + # at once. Localizing the stack pointer means that it will automatically + # unwind the same amount when multiple stack frames are unwound. + local $stack_depth = $stack_depth + 1; # Protect from non-local exits + + # Expand @stack. + $#stack = $stack_depth; + + # Save current single-step setting. + $stack[-1] = $single; + + # Turn off all flags except single-stepping. + $single &= 1; + + # If we've gotten really deeply recursed, turn on the flag that will + # make us stop with the 'deep recursion' message. + $single |= 4 if $stack_depth == $deep; + + # If frame messages are on ... + ( + $frame & 4 # Extended frame entry message + ? ( + print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ), + + # Why -1? But it works! :-( + # Because print_trace will call add 1 to it and then call + # dump_trace; this results in our skipping -1+1 = 0 stack frames + # in dump_trace. + print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) + ) + : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" ) + + # standard frame entry message + ) + if $frame; + + # Determine the sub's return type,and capture approppriately. + if (wantarray) { + + # Called in array context. call sub and capture output. + # DB::DB will recursively get control again if appropriate; we'll come + # back here when the sub is finished. + @ret = &$sub; + + # Pop the single-step value back off the stack. + $single |= $stack[ $stack_depth-- ]; + + # Check for exit trace messages... + ( + $frame & 4 # Extended exit message + ? ( + print_lineinfo( ' ' x $stack_depth, "out " ), + print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) + ) + : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" ) + + # Standard exit message + ) + if $frame & 2; + + # Print the return info if we need to. + if ( $doret eq $stack_depth or $frame & 16 ) { + + # Turn off output record separator. + local $\ = ''; + my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); + + # Indent if we're printing because of $frame tracing. + print $fh ' ' x $stack_depth if $frame & 16; + + # Print the return value. + print $fh "list context return from $sub:\n"; + dumpit( $fh, \@ret ); + + # And don't print it again. + $doret = -2; + } ## end if ($doret eq $stack_depth... + # And we have to return the return value now. + @ret; + } ## end if (wantarray) + + # Scalar context. + else { + if ( defined wantarray ) { + + # Save the value if it's wanted at all. + $ret = &$sub; + } + else { + + # Void return, explicitly. + &$sub; + undef $ret; + } + + # Pop the single-step value off the stack. + $single |= $stack[ $stack_depth-- ]; + + # If we're doing exit messages... + ( + $frame & 4 # Extended messsages + ? ( + print_lineinfo( ' ' x $stack_depth, "out " ), + print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) + ) + : print_lineinfo( ' ' x $stack_depth, "exited $sub$al\n" ) + + # Standard messages + ) + if $frame & 2; + + # If we are supposed to show the return value... same as before. + if ( $doret eq $stack_depth or $frame & 16 and defined wantarray ) { + local $\ = ''; + my $fh = ( $doret eq $stack_depth ? $OUT : $LINEINFO ); + print $fh ( ' ' x $stack_depth ) if $frame & 16; + print $fh ( + defined wantarray + ? "scalar context return from $sub: " + : "void context return from $sub\n" + ); + dumpit( $fh, $ret ) if defined wantarray; + $doret = -2; + } ## end if ($doret eq $stack_depth... + + # Return the appropriate scalar value. + $ret; + } ## end else [ if (wantarray) +} ## end sub sub + +sub lsub : lvalue { + + # lock ourselves under threads + lock($DBGR); + + # Whether or not the autoloader was running, a scalar to put the + # sub's return value in (if needed), and an array to put the sub's + # return value in (if needed). + my ( $al, $ret, @ret ) = ""; + if ($sub =~ /^threads::new$/ && $ENV{PERL5DB_THREADED}) { + print "creating new thread\n"; + } + + # If the last ten characters are C'::AUTOLOAD', note we've traced + # into AUTOLOAD for $sub. + if ( length($sub) > 10 && substr( $sub, -10, 10 ) eq '::AUTOLOAD' ) { + $al = " for $$sub"; + } + + # We stack the stack pointer and then increment it to protect us + # from a situation that might unwind a whole bunch of call frames + # at once. Localizing the stack pointer means that it will automatically + # unwind the same amount when multiple stack frames are unwound. + local $stack_depth = $stack_depth + 1; # Protect from non-local exits + + # Expand @stack. + $#stack = $stack_depth; + + # Save current single-step setting. + $stack[-1] = $single; + + # Turn off all flags except single-stepping. + $single &= 1; + + # If we've gotten really deeply recursed, turn on the flag that will + # make us stop with the 'deep recursion' message. + $single |= 4 if $stack_depth == $deep; + + # If frame messages are on ... + ( + $frame & 4 # Extended frame entry message + ? ( + print_lineinfo( ' ' x ( $stack_depth - 1 ), "in " ), + + # Why -1? But it works! :-( + # Because print_trace will call add 1 to it and then call + # dump_trace; this results in our skipping -1+1 = 0 stack frames + # in dump_trace. + print_trace( $LINEINFO, -1, 1, 1, "$sub$al" ) + ) + : print_lineinfo( ' ' x ( $stack_depth - 1 ), "entering $sub$al\n" ) + + # standard frame entry message + ) + if $frame; + + # Pop the single-step value back off the stack. + $single |= $stack[ $stack_depth-- ]; + + # call the original lvalue sub. + &$sub; +} + +=head1 EXTENDED COMMAND HANDLING AND THE COMMAND API + +In Perl 5.8.0, there was a major realignment of the commands and what they did, +Most of the changes were to systematize the command structure and to eliminate +commands that threw away user input without checking. + +The following sections describe the code added to make it easy to support +multiple command sets with conflicting command names. This section is a start +at unifying all command processing to make it simpler to develop commands. + +Note that all the cmd_[a-zA-Z] subroutines require the command name, a line +number, and C<$dbline> (the current line) as arguments. + +Support functions in this section which have multiple modes of failure C<die> +on error; the rest simply return a false value. + +The user-interface functions (all of the C<cmd_*> functions) just output +error messages. + +=head2 C<%set> + +The C<%set> hash defines the mapping from command letter to subroutine +name suffix. + +C<%set> is a two-level hash, indexed by set name and then by command name. +Note that trying to set the CommandSet to C<foobar> simply results in the +5.8.0 command set being used, since there's no top-level entry for C<foobar>. + +=cut + +### The API section + +my %set = ( # + 'pre580' => { + 'a' => 'pre580_a', + 'A' => 'pre580_null', + 'b' => 'pre580_b', + 'B' => 'pre580_null', + 'd' => 'pre580_null', + 'D' => 'pre580_D', + 'h' => 'pre580_h', + 'M' => 'pre580_null', + 'O' => 'o', + 'o' => 'pre580_null', + 'v' => 'M', + 'w' => 'v', + 'W' => 'pre580_W', + }, + 'pre590' => { + '<' => 'pre590_prepost', + '<<' => 'pre590_prepost', + '>' => 'pre590_prepost', + '>>' => 'pre590_prepost', + '{' => 'pre590_prepost', + '{{' => 'pre590_prepost', + }, +); + +=head2 C<cmd_wrapper()> (API) + +C<cmd_wrapper()> allows the debugger to switch command sets +depending on the value of the C<CommandSet> option. + +It tries to look up the command in the C<%set> package-level I<lexical> +(which means external entities can't fiddle with it) and create the name of +the sub to call based on the value found in the hash (if it's there). I<All> +of the commands to be handled in a set have to be added to C<%set>; if they +aren't found, the 5.8.0 equivalent is called (if there is one). + +This code uses symbolic references. + +=cut + +sub cmd_wrapper { + my $cmd = shift; + my $line = shift; + my $dblineno = shift; + + # Assemble the command subroutine's name by looking up the + # command set and command name in %set. If we can't find it, + # default to the older version of the command. + my $call = 'cmd_' + . ( $set{$CommandSet}{$cmd} + || ( $cmd =~ /^[<>{]+/o ? 'prepost' : $cmd ) ); + + # Call the command subroutine, call it by name. + return &$call( $cmd, $line, $dblineno ); +} ## end sub cmd_wrapper + +=head3 C<cmd_a> (command) + +The C<a> command handles pre-execution actions. These are associated with a +particular line, so they're stored in C<%dbline>. We default to the current +line if none is specified. + +=cut + +sub cmd_a { + my $cmd = shift; + my $line = shift || ''; # [.|line] expr + my $dbline = shift; + + # If it's dot (here), or not all digits, use the current line. + $line =~ s/^(\.|(?:[^\d]))/$dbline/; + + # Should be a line number followed by an expression. + if ( $line =~ /^\s*(\d*)\s*(\S.+)/ ) { + my ( $lineno, $expr ) = ( $1, $2 ); + + # If we have an expression ... + if ( length $expr ) { + + # ... but the line isn't breakable, complain. + if ( $dbline[$lineno] == 0 ) { + print $OUT + "Line $lineno($dbline[$lineno]) does not have an action?\n"; + } + else { + + # It's executable. Record that the line has an action. + $had_breakpoints{$filename} |= 2; + + # Remove any action, temp breakpoint, etc. + $dbline{$lineno} =~ s/\0[^\0]*//; + + # Add the action to the line. + $dbline{$lineno} .= "\0" . action($expr); + } + } ## end if (length $expr) + } ## end if ($line =~ /^\s*(\d*)\s*(\S.+)/) + else { + + # Syntax wrong. + print $OUT + "Adding an action requires an optional lineno and an expression\n" + ; # hint + } +} ## end sub cmd_a + +=head3 C<cmd_A> (command) + +Delete actions. Similar to above, except the delete code is in a separate +subroutine, C<delete_action>. + +=cut + +sub cmd_A { + my $cmd = shift; + my $line = shift || ''; + my $dbline = shift; + + # Dot is this line. + $line =~ s/^\./$dbline/; + + # Call delete_action with a null param to delete them all. + # The '1' forces the eval to be true. It'll be false only + # if delete_action blows up for some reason, in which case + # we print $@ and get out. + if ( $line eq '*' ) { + eval { &delete_action(); 1 } or print $OUT $@ and return; + } + + # There's a real line number. Pass it to delete_action. + # Error trapping is as above. + elsif ( $line =~ /^(\S.*)/ ) { + eval { &delete_action($1); 1 } or print $OUT $@ and return; + } + + # Swing and a miss. Bad syntax. + else { + print $OUT + "Deleting an action requires a line number, or '*' for all\n" ; # hint + } +} ## end sub cmd_A + +=head3 C<delete_action> (API) + +C<delete_action> accepts either a line number or C<undef>. If a line number +is specified, we check for the line being executable (if it's not, it +couldn't have had an action). If it is, we just take the action off (this +will get any kind of an action, including breakpoints). + +=cut + +sub delete_action { + my $i = shift; + if ( defined($i) ) { + + # Can there be one? + die "Line $i has no action .\n" if $dbline[$i] == 0; + + # Nuke whatever's there. + $dbline{$i} =~ s/\0[^\0]*//; # \^a + delete $dbline{$i} if $dbline{$i} eq ''; + } + else { + print $OUT "Deleting all actions...\n"; + for my $file ( keys %had_breakpoints ) { + local *dbline = $main::{ '_<' . $file }; + my $max = $#dbline; + my $was; + for ( $i = 1 ; $i <= $max ; $i++ ) { + if ( defined $dbline{$i} ) { + $dbline{$i} =~ s/\0[^\0]*//; + delete $dbline{$i} if $dbline{$i} eq ''; + } + unless ( $had_breakpoints{$file} &= ~2 ) { + delete $had_breakpoints{$file}; + } + } ## end for ($i = 1 ; $i <= $max... + } ## end for my $file (keys %had_breakpoints) + } ## end else [ if (defined($i)) +} ## end sub delete_action + +=head3 C<cmd_b> (command) + +Set breakpoints. Since breakpoints can be set in so many places, in so many +ways, conditionally or not, the breakpoint code is kind of complex. Mostly, +we try to parse the command type, and then shuttle it off to an appropriate +subroutine to actually do the work of setting the breakpoint in the right +place. + +=cut + +sub cmd_b { + my $cmd = shift; + my $line = shift; # [.|line] [cond] + my $dbline = shift; + + # Make . the current line number if it's there.. + $line =~ s/^\./$dbline/; + + # No line number, no condition. Simple break on current line. + if ( $line =~ /^\s*$/ ) { + &cmd_b_line( $dbline, 1 ); + } + + # Break on load for a file. + elsif ( $line =~ /^load\b\s*(.*)/ ) { + my $file = $1; + $file =~ s/\s+$//; + &cmd_b_load($file); + } + + # b compile|postpone <some sub> [<condition>] + # The interpreter actually traps this one for us; we just put the + # necessary condition in the %postponed hash. + elsif ( $line =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { + + # Capture the condition if there is one. Make it true if none. + my $cond = length $3 ? $3 : '1'; + + # Save the sub name and set $break to 1 if $1 was 'postpone', 0 + # if it was 'compile'. + my ( $subname, $break ) = ( $2, $1 eq 'postpone' ); + + # De-Perl4-ify the name - ' separators to ::. + $subname =~ s/\'/::/g; + + # Qualify it into the current package unless it's already qualified. + $subname = "${'package'}::" . $subname unless $subname =~ /::/; + + # Add main if it starts with ::. + $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; + + # Save the break type for this sub. + $postponed{$subname} = $break ? "break +0 if $cond" : "compile"; + } ## end elsif ($line =~ ... + + # b <sub name> [<condition>] + elsif ( $line =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { + + # + $subname = $1; + $cond = length $2 ? $2 : '1'; + &cmd_b_sub( $subname, $cond ); + } + + # b <line> [<condition>]. + elsif ( $line =~ /^(\d*)\s*(.*)/ ) { + + # Capture the line. If none, it's the current line. + $line = $1 || $dbline; + + # If there's no condition, make it '1'. + $cond = length $2 ? $2 : '1'; + + # Break on line. + &cmd_b_line( $line, $cond ); + } + + # Line didn't make sense. + else { + print "confused by line($line)?\n"; + } +} ## end sub cmd_b + +=head3 C<break_on_load> (API) + +We want to break when this file is loaded. Mark this file in the +C<%break_on_load> hash, and note that it has a breakpoint in +C<%had_breakpoints>. + +=cut + +sub break_on_load { + my $file = shift; + $break_on_load{$file} = 1; + $had_breakpoints{$file} |= 1; +} + +=head3 C<report_break_on_load> (API) + +Gives us an array of filenames that are set to break on load. Note that +only files with break-on-load are in here, so simply showing the keys +suffices. + +=cut + +sub report_break_on_load { + sort keys %break_on_load; +} + +=head3 C<cmd_b_load> (command) + +We take the file passed in and try to find it in C<%INC> (which maps modules +to files they came from). We mark those files for break-on-load via +C<break_on_load> and then report that it was done. + +=cut + +sub cmd_b_load { + my $file = shift; + my @files; + + # This is a block because that way we can use a redo inside it + # even without there being any looping structure at all outside it. + { + + # Save short name and full path if found. + push @files, $file; + push @files, $::INC{$file} if $::INC{$file}; + + # Tack on .pm and do it again unless there was a '.' in the name + # already. + $file .= '.pm', redo unless $file =~ /\./; + } + + # Do the real work here. + break_on_load($_) for @files; + + # All the files that have break-on-load breakpoints. + @files = report_break_on_load; + + # Normalize for the purposes of our printing this. + local $\ = ''; + local $" = ' '; + print $OUT "Will stop on load of `@files'.\n"; +} ## end sub cmd_b_load + +=head3 C<$filename_error> (API package global) + +Several of the functions we need to implement in the API need to work both +on the current file and on other files. We don't want to duplicate code, so +C<$filename_error> is used to contain the name of the file that's being +worked on (if it's not the current one). + +We can now build functions in pairs: the basic function works on the current +file, and uses C<$filename_error> as part of its error message. Since this is +initialized to C<"">, no filename will appear when we are working on the +current file. + +The second function is a wrapper which does the following: + +=over 4 + +=item * + +Localizes C<$filename_error> and sets it to the name of the file to be processed. + +=item * + +Localizes the C<*dbline> glob and reassigns it to point to the file we want to process. + +=item * + +Calls the first function. + +The first function works on the I<current> file (i.e., the one we changed to), +and prints C<$filename_error> in the error message (the name of the other file) +if it needs to. When the functions return, C<*dbline> is restored to point +to the actual current file (the one we're executing in) and +C<$filename_error> is restored to C<"">. This restores everything to +the way it was before the second function was called at all. + +See the comments in C<breakable_line> and C<breakable_line_in_file> for more +details. + +=back + +=cut + +$filename_error = ''; + +=head3 breakable_line(from, to) (API) + +The subroutine decides whether or not a line in the current file is breakable. +It walks through C<@dbline> within the range of lines specified, looking for +the first line that is breakable. + +If C<$to> is greater than C<$from>, the search moves forwards, finding the +first line I<after> C<$to> that's breakable, if there is one. + +If C<$from> is greater than C<$to>, the search goes I<backwards>, finding the +first line I<before> C<$to> that's breakable, if there is one. + +=cut + +sub breakable_line { + + my ( $from, $to ) = @_; + + # $i is the start point. (Where are the FORTRAN programs of yesteryear?) + my $i = $from; + + # If there are at least 2 arguments, we're trying to search a range. + if ( @_ >= 2 ) { + + # $delta is positive for a forward search, negative for a backward one. + my $delta = $from < $to ? +1 : -1; + + # Keep us from running off the ends of the file. + my $limit = $delta > 0 ? $#dbline : 1; + + # Clever test. If you're a mathematician, it's obvious why this + # test works. If not: + # If $delta is positive (going forward), $limit will be $#dbline. + # If $to is less than $limit, ($limit - $to) will be positive, times + # $delta of 1 (positive), so the result is > 0 and we should use $to + # as the stopping point. + # + # If $to is greater than $limit, ($limit - $to) is negative, + # times $delta of 1 (positive), so the result is < 0 and we should + # use $limit ($#dbline) as the stopping point. + # + # If $delta is negative (going backward), $limit will be 1. + # If $to is zero, ($limit - $to) will be 1, times $delta of -1 + # (negative) so the result is > 0, and we use $to as the stopping + # point. + # + # If $to is less than zero, ($limit - $to) will be positive, + # times $delta of -1 (negative), so the result is not > 0, and + # we use $limit (1) as the stopping point. + # + # If $to is 1, ($limit - $to) will zero, times $delta of -1 + # (negative), still giving zero; the result is not > 0, and + # we use $limit (1) as the stopping point. + # + # if $to is >1, ($limit - $to) will be negative, times $delta of -1 + # (negative), giving a positive (>0) value, so we'll set $limit to + # $to. + + $limit = $to if ( $limit - $to ) * $delta > 0; + + # The real search loop. + # $i starts at $from (the point we want to start searching from). + # We move through @dbline in the appropriate direction (determined + # by $delta: either -1 (back) or +1 (ahead). + # We stay in as long as we haven't hit an executable line + # ($dbline[$i] == 0 means not executable) and we haven't reached + # the limit yet (test similar to the above). + $i += $delta while $dbline[$i] == 0 and ( $limit - $i ) * $delta > 0; + + } ## end if (@_ >= 2) + + # If $i points to a line that is executable, return that. + return $i unless $dbline[$i] == 0; + + # Format the message and print it: no breakable lines in range. + my ( $pl, $upto ) = ( '', '' ); + ( $pl, $upto ) = ( 's', "..$to" ) if @_ >= 2 and $from != $to; + + # If there's a filename in filename_error, we'll see it. + # If not, not. + die "Line$pl $from$upto$filename_error not breakable\n"; +} ## end sub breakable_line + +=head3 breakable_line_in_filename(file, from, to) (API) + +Like C<breakable_line>, but look in another file. + +=cut + +sub breakable_line_in_filename { + + # Capture the file name. + my ($f) = shift; + + # Swap the magic line array over there temporarily. + local *dbline = $main::{ '_<' . $f }; + + # If there's an error, it's in this other file. + local $filename_error = " of `$f'"; + + # Find the breakable line. + breakable_line(@_); + + # *dbline and $filename_error get restored when this block ends. + +} ## end sub breakable_line_in_filename + +=head3 break_on_line(lineno, [condition]) (API) + +Adds a breakpoint with the specified condition (or 1 if no condition was +specified) to the specified line. Dies if it can't. + +=cut + +sub break_on_line { + my ( $i, $cond ) = @_; + + # Always true if no condition supplied. + $cond = 1 unless @_ >= 2; + + my $inii = $i; + my $after = ''; + my $pl = ''; + + # Woops, not a breakable line. $filename_error allows us to say + # if it was in a different file. + die "Line $i$filename_error not breakable.\n" if $dbline[$i] == 0; + + # Mark this file as having breakpoints in it. + $had_breakpoints{$filename} |= 1; + + # If there is an action or condition here already ... + if ( $dbline{$i} ) { + + # ... swap this condition for the existing one. + $dbline{$i} =~ s/^[^\0]*/$cond/; + } + else { + + # Nothing here - just add the condition. + $dbline{$i} = $cond; + } +} ## end sub break_on_line + +=head3 cmd_b_line(line, [condition]) (command) + +Wrapper for C<break_on_line>. Prints the failure message if it +doesn't work. + +=cut + +sub cmd_b_line { + eval { break_on_line(@_); 1 } or do { + local $\ = ''; + print $OUT $@ and return; + }; +} ## end sub cmd_b_line + +=head3 break_on_filename_line(file, line, [condition]) (API) + +Switches to the file specified and then calls C<break_on_line> to set +the breakpoint. + +=cut + +sub break_on_filename_line { + my ( $f, $i, $cond ) = @_; + + # Always true if condition left off. + $cond = 1 unless @_ >= 3; + + # Switch the magical hash temporarily. + local *dbline = $main::{ '_<' . $f }; + + # Localize the variables that break_on_line uses to make its message. + local $filename_error = " of `$f'"; + local $filename = $f; + + # Add the breakpoint. + break_on_line( $i, $cond ); +} ## end sub break_on_filename_line + +=head3 break_on_filename_line_range(file, from, to, [condition]) (API) + +Switch to another file, search the range of lines specified for an +executable one, and put a breakpoint on the first one you find. + +=cut + +sub break_on_filename_line_range { + my ( $f, $from, $to, $cond ) = @_; + + # Find a breakable line if there is one. + my $i = breakable_line_in_filename( $f, $from, $to ); + + # Always true if missing. + $cond = 1 unless @_ >= 3; + + # Add the breakpoint. + break_on_filename_line( $f, $i, $cond ); +} ## end sub break_on_filename_line_range + +=head3 subroutine_filename_lines(subname, [condition]) (API) + +Search for a subroutine within a given file. The condition is ignored. +Uses C<find_sub> to locate the desired subroutine. + +=cut + +sub subroutine_filename_lines { + my ( $subname, $cond ) = @_; + + # Returned value from find_sub() is fullpathname:startline-endline. + # The match creates the list (fullpathname, start, end). Falling off + # the end of the subroutine returns this implicitly. + find_sub($subname) =~ /^(.*):(\d+)-(\d+)$/; +} ## end sub subroutine_filename_lines + +=head3 break_subroutine(subname) (API) + +Places a break on the first line possible in the specified subroutine. Uses +C<subroutine_filename_lines> to find the subroutine, and +C<break_on_filename_line_range> to place the break. + +=cut + +sub break_subroutine { + my $subname = shift; + + # Get filename, start, and end. + my ( $file, $s, $e ) = subroutine_filename_lines($subname) + or die "Subroutine $subname not found.\n"; + + # Null condition changes to '1' (always true). + $cond = 1 unless @_ >= 2; + + # Put a break the first place possible in the range of lines + # that make up this subroutine. + break_on_filename_line_range( $file, $s, $e, @_ ); +} ## end sub break_subroutine + +=head3 cmd_b_sub(subname, [condition]) (command) + +We take the incoming subroutine name and fully-qualify it as best we can. + +=over 4 + +=item 1. If it's already fully-qualified, leave it alone. + +=item 2. Try putting it in the current package. + +=item 3. If it's not there, try putting it in CORE::GLOBAL if it exists there. + +=item 4. If it starts with '::', put it in 'main::'. + +=back + +After all this cleanup, we call C<break_subroutine> to try to set the +breakpoint. + +=cut + +sub cmd_b_sub { + my ( $subname, $cond ) = @_; + + # Add always-true condition if we have none. + $cond = 1 unless @_ >= 2; + + # If the subname isn't a code reference, qualify it so that + # break_subroutine() will work right. + unless ( ref $subname eq 'CODE' ) { + + # Not Perl4. + $subname =~ s/\'/::/g; + my $s = $subname; + + # Put it in this package unless it's already qualified. + $subname = "${'package'}::" . $subname + unless $subname =~ /::/; + + # Requalify it into CORE::GLOBAL if qualifying it into this + # package resulted in its not being defined, but only do so + # if it really is in CORE::GLOBAL. + $subname = "CORE::GLOBAL::$s" + if not defined &$subname + and $s !~ /::/ + and defined &{"CORE::GLOBAL::$s"}; + + # Put it in package 'main' if it has a leading ::. + $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; + + } ## end unless (ref $subname eq 'CODE') + + # Try to set the breakpoint. + eval { break_subroutine( $subname, $cond ); 1 } or do { + local $\ = ''; + print $OUT $@ and return; + } +} ## end sub cmd_b_sub + +=head3 C<cmd_B> - delete breakpoint(s) (command) + +The command mostly parses the command line and tries to turn the argument +into a line spec. If it can't, it uses the current line. It then calls +C<delete_breakpoint> to actually do the work. + +If C<*> is specified, C<cmd_B> calls C<delete_breakpoint> with no arguments, +thereby deleting all the breakpoints. + +=cut + +sub cmd_B { + my $cmd = shift; + + # No line spec? Use dbline. + # If there is one, use it if it's non-zero, or wipe it out if it is. + my $line = ( $_[0] =~ /^\./ ) ? $dbline : shift || ''; + my $dbline = shift; + + # If the line was dot, make the line the current one. + $line =~ s/^\./$dbline/; + + # If it's * we're deleting all the breakpoints. + if ( $line eq '*' ) { + eval { &delete_breakpoint(); 1 } or print $OUT $@ and return; + } + + # If there is a line spec, delete the breakpoint on that line. + elsif ( $line =~ /^(\S.*)/ ) { + eval { &delete_breakpoint( $line || $dbline ); 1 } or do { + local $\ = ''; + print $OUT $@ and return; + }; + } ## end elsif ($line =~ /^(\S.*)/) + + # No line spec. + else { + print $OUT + "Deleting a breakpoint requires a line number, or '*' for all\n" + ; # hint + } +} ## end sub cmd_B + +=head3 delete_breakpoint([line]) (API) + +This actually does the work of deleting either a single breakpoint, or all +of them. + +For a single line, we look for it in C<@dbline>. If it's nonbreakable, we +just drop out with a message saying so. If it is, we remove the condition +part of the 'condition\0action' that says there's a breakpoint here. If, +after we've done that, there's nothing left, we delete the corresponding +line in C<%dbline> to signal that no action needs to be taken for this line. + +For all breakpoints, we iterate through the keys of C<%had_breakpoints>, +which lists all currently-loaded files which have breakpoints. We then look +at each line in each of these files, temporarily switching the C<%dbline> +and C<@dbline> structures to point to the files in question, and do what +we did in the single line case: delete the condition in C<@dbline>, and +delete the key in C<%dbline> if nothing's left. + +We then wholesale delete C<%postponed>, C<%postponed_file>, and +C<%break_on_load>, because these structures contain breakpoints for files +and code that haven't been loaded yet. We can just kill these off because there +are no magical debugger structures associated with them. + +=cut + +sub delete_breakpoint { + my $i = shift; + + # If we got a line, delete just that one. + if ( defined($i) ) { + + # Woops. This line wasn't breakable at all. + die "Line $i not breakable.\n" if $dbline[$i] == 0; + + # Kill the condition, but leave any action. + $dbline{$i} =~ s/^[^\0]*//; + + # Remove the entry entirely if there's no action left. + delete $dbline{$i} if $dbline{$i} eq ''; + } + + # No line; delete them all. + else { + print $OUT "Deleting all breakpoints...\n"; + + # %had_breakpoints lists every file that had at least one + # breakpoint in it. + for my $file ( keys %had_breakpoints ) { + + # Switch to the desired file temporarily. + local *dbline = $main::{ '_<' . $file }; + + my $max = $#dbline; + my $was; + + # For all lines in this file ... + for ( $i = 1 ; $i <= $max ; $i++ ) { + + # If there's a breakpoint or action on this line ... + if ( defined $dbline{$i} ) { + + # ... remove the breakpoint. + $dbline{$i} =~ s/^[^\0]+//; + if ( $dbline{$i} =~ s/^\0?$// ) { + + # Remove the entry altogether if no action is there. + delete $dbline{$i}; + } + } ## end if (defined $dbline{$i... + } ## end for ($i = 1 ; $i <= $max... + + # If, after we turn off the "there were breakpoints in this file" + # bit, the entry in %had_breakpoints for this file is zero, + # we should remove this file from the hash. + if ( not $had_breakpoints{$file} &= ~1 ) { + delete $had_breakpoints{$file}; + } + } ## end for my $file (keys %had_breakpoints) + + # Kill off all the other breakpoints that are waiting for files that + # haven't been loaded yet. + undef %postponed; + undef %postponed_file; + undef %break_on_load; + } ## end else [ if (defined($i)) +} ## end sub delete_breakpoint + +=head3 cmd_stop (command) + +This is meant to be part of the new command API, but it isn't called or used +anywhere else in the debugger. XXX It is probably meant for use in development +of new commands. + +=cut + +sub cmd_stop { # As on ^C, but not signal-safy. + $signal = 1; +} + +=head3 C<cmd_e> - threads + +Display the current thread id: + + e + +This could be how (when implemented) to send commands to this thread id (e cmd) +or that thread id (e tid cmd). + +=cut + +sub cmd_e { + my $cmd = shift; + my $line = shift; + unless (exists($INC{'threads.pm'})) { + print "threads not loaded($ENV{PERL5DB_THREADED}) + please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; + } else { + my $tid = threads->tid; + print "thread id: $tid\n"; + } +} ## end sub cmd_e + +=head3 C<cmd_E> - list of thread ids + +Display the list of available thread ids: + + E + +This could be used (when implemented) to send commands to all threads (E cmd). + +=cut + +sub cmd_E { + my $cmd = shift; + my $line = shift; + unless (exists($INC{'threads.pm'})) { + print "threads not loaded($ENV{PERL5DB_THREADED}) + please run the debugger with PERL5DB_THREADED=1 set in the environment\n"; + } else { + my $tid = threads->tid; + print "thread ids: ".join(', ', + map { ($tid == $_->tid ? '<'.$_->tid.'>' : $_->tid) } threads->list + )."\n"; + } +} ## end sub cmd_E + +=head3 C<cmd_h> - help command (command) + +Does the work of either + +=over 4 + +=item * + +Showing all the debugger help + +=item * + +Showing help for a specific command + +=back + +=cut + +sub cmd_h { + my $cmd = shift; + + # If we have no operand, assume null. + my $line = shift || ''; + + # 'h h'. Print the long-format help. + if ( $line =~ /^h\s*/ ) { + print_help($help); + } + + # 'h <something>'. Search for the command and print only its help. + elsif ( $line =~ /^(\S.*)$/ ) { + + # support long commands; otherwise bogus errors + # happen when you ask for h on <CR> for example + my $asked = $1; # the command requested + # (for proper error message) + + my $qasked = quotemeta($asked); # for searching; we don't + # want to use it as a pattern. + # XXX: finds CR but not <CR> + + # Search the help string for the command. + if ( + $help =~ /^ # Start of a line + <? # Optional '<' + (?:[IB]<) # Optional markup + $qasked # The requested command + /mx + ) + { + + # It's there; pull it out and print it. + while ( + $help =~ /^ + (<? # Optional '<' + (?:[IB]<) # Optional markup + $qasked # The command + ([\s\S]*?) # Description line(s) + \n) # End of last description line + (?!\s) # Next line not starting with + # whitespace + /mgx + ) + { + print_help($1); + } + } + + # Not found; not a debugger command. + else { + print_help("B<$asked> is not a debugger command.\n"); + } + } ## end elsif ($line =~ /^(\S.*)$/) + + # 'h' - print the summary help. + else { + print_help($summary); + } +} ## end sub cmd_h + +=head3 C<cmd_i> - inheritance display + +Display the (nested) parentage of the module or object given. + +=cut + +sub cmd_i { + my $cmd = shift; + my $line = shift; + eval { require Class::ISA }; + if ($@) { + &warn( $@ =~ /locate/ + ? "Class::ISA module not found - please install\n" + : $@ ); + } + else { + ISA: + foreach my $isa ( split( /\s+/, $line ) ) { + $evalarg = $isa; + ($isa) = &eval; + no strict 'refs'; + print join( + ', ', + map { # snaffled unceremoniously from Class::ISA + "$_" + . ( + defined( ${"$_\::VERSION"} ) + ? ' ' . ${"$_\::VERSION"} + : undef ) + } Class::ISA::self_and_super_path(ref($isa) || $isa) + ); + print "\n"; + } + } +} ## end sub cmd_i + +=head3 C<cmd_l> - list lines (command) + +Most of the command is taken up with transforming all the different line +specification syntaxes into 'start-stop'. After that is done, the command +runs a loop over C<@dbline> for the specified range of lines. It handles +the printing of each line and any markers (C<==E<gt>> for current line, +C<b> for break on this line, C<a> for action on this line, C<:> for this +line breakable). + +We save the last line listed in the C<$start> global for further listing +later. + +=cut + +sub cmd_l { + my $current_line = $line; + my $cmd = shift; + my $line = shift; + + # If this is '-something', delete any spaces after the dash. + $line =~ s/^-\s*$/-/; + + # If the line is '$something', assume this is a scalar containing a + # line number. + if ( $line =~ /^(\$.*)/s ) { + + # Set up for DB::eval() - evaluate in *user* context. + $evalarg = $1; + # $evalarg = $2; + my ($s) = &eval; + + # Ooops. Bad scalar. + print( $OUT "Error: $@\n" ), next CMD if $@; + + # Good scalar. If it's a reference, find what it points to. + $s = CvGV_name($s); + print( $OUT "Interpreted as: $1 $s\n" ); + $line = "$1 $s"; + + # Call self recursively to really do the command. + &cmd_l( 'l', $s ); + } ## end if ($line =~ /^(\$.*)/s) + + # l name. Try to find a sub by that name. + elsif ( $line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s ) { + my $s = $subname = $1; + + # De-Perl4. + $subname =~ s/\'/::/; + + # Put it in this package unless it starts with ::. + $subname = $package . "::" . $subname unless $subname =~ /::/; + + # Put it in CORE::GLOBAL if t doesn't start with :: and + # it doesn't live in this package and it lives in CORE::GLOBAL. + $subname = "CORE::GLOBAL::$s" + if not defined &$subname + and $s !~ /::/ + and defined &{"CORE::GLOBAL::$s"}; + + # Put leading '::' names into 'main::'. + $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; + + # Get name:start-stop from find_sub, and break this up at + # colons. + @pieces = split( /:/, find_sub($subname) || $sub{$subname} ); + + # Pull off start-stop. + $subrange = pop @pieces; + + # If the name contained colons, the split broke it up. + # Put it back together. + $file = join( ':', @pieces ); + + # If we're not in that file, switch over to it. + if ( $file ne $filename ) { + print $OUT "Switching to file '$file'.\n" + unless $slave_editor; + + # Switch debugger's magic structures. + *dbline = $main::{ '_<' . $file }; + $max = $#dbline; + $filename = $file; + } ## end if ($file ne $filename) + + # Subrange is 'start-stop'. If this is less than a window full, + # swap it to 'start+', which will list a window from the start point. + if ($subrange) { + if ( eval($subrange) < -$window ) { + $subrange =~ s/-.*/+/; + } + + # Call self recursively to list the range. + $line = $subrange; + &cmd_l( 'l', $subrange ); + } ## end if ($subrange) + + # Couldn't find it. + else { + print $OUT "Subroutine $subname not found.\n"; + } + } ## end elsif ($line =~ /^([\':A-Za-z_][\':\w]*(\[.*\])?)/s) + + # Bare 'l' command. + elsif ( $line =~ /^\s*$/ ) { + + # Compute new range to list. + $incr = $window - 1; + $line = $start . '-' . ( $start + $incr ); + + # Recurse to do it. + &cmd_l( 'l', $line ); + } + + # l [start]+number_of_lines + elsif ( $line =~ /^(\d*)\+(\d*)$/ ) { + + # Don't reset start for 'l +nnn'. + $start = $1 if $1; + + # Increment for list. Use window size if not specified. + # (Allows 'l +' to work.) + $incr = $2; + $incr = $window - 1 unless $incr; + + # Create a line range we'll understand, and recurse to do it. + $line = $start . '-' . ( $start + $incr ); + &cmd_l( 'l', $line ); + } ## end elsif ($line =~ /^(\d*)\+(\d*)$/) + + # l start-stop or l start,stop + elsif ( $line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/ ) { + + # Determine end point; use end of file if not specified. + $end = ( !defined $2 ) ? $max : ( $4 ? $4 : $2 ); + + # Go on to the end, and then stop. + $end = $max if $end > $max; + + # Determine start line. + $i = $2; + $i = $line if $i eq '.'; + $i = 1 if $i < 1; + $incr = $end - $i; + + # If we're running under a slave editor, force it to show the lines. + if ($slave_editor) { + print $OUT "\032\032$filename:$i:0\n"; + $i = $end; + } + + # We're doing it ourselves. We want to show the line and special + # markers for: + # - the current line in execution + # - whether a line is breakable or not + # - whether a line has a break or not + # - whether a line has an action or not + else { + for ( ; $i <= $end ; $i++ ) { + + # Check for breakpoints and actions. + my ( $stop, $action ); + ( $stop, $action ) = split( /\0/, $dbline{$i} ) + if $dbline{$i}; + + # ==> if this is the current line in execution, + # : if it's breakable. + $arrow = + ( $i == $current_line and $filename eq $filename_ini ) + ? '==>' + : ( $dbline[$i] + 0 ? ':' : ' ' ); + + # Add break and action indicators. + $arrow .= 'b' if $stop; + $arrow .= 'a' if $action; + + # Print the line. + print $OUT "$i$arrow\t", $dbline[$i]; + + # Move on to the next line. Drop out on an interrupt. + $i++, last if $signal; + } ## end for (; $i <= $end ; $i++) + + # Line the prompt up; print a newline if the last line listed + # didn't have a newline. + print $OUT "\n" unless $dbline[ $i - 1 ] =~ /\n$/; + } ## end else [ if ($slave_editor) + + # Save the point we last listed to in case another relative 'l' + # command is desired. Don't let it run off the end. + $start = $i; + $start = $max if $start > $max; + } ## end elsif ($line =~ /^((-?[\d\$\.]+)([-,]([\d\$\.]+))?)?/) +} ## end sub cmd_l + +=head3 C<cmd_L> - list breakpoints, actions, and watch expressions (command) + +To list breakpoints, the command has to look determine where all of them are +first. It starts a C<%had_breakpoints>, which tells us what all files have +breakpoints and/or actions. For each file, we switch the C<*dbline> glob (the +magic source and breakpoint data structures) to the file, and then look +through C<%dbline> for lines with breakpoints and/or actions, listing them +out. We look through C<%postponed> not-yet-compiled subroutines that have +breakpoints, and through C<%postponed_file> for not-yet-C<require>'d files +that have breakpoints. + +Watchpoints are simpler: we just list the entries in C<@to_watch>. + +=cut + +sub cmd_L { + my $cmd = shift; + + # If no argument, list everything. Pre-5.8.0 version always lists + # everything + my $arg = shift || 'abw'; + $arg = 'abw' unless $CommandSet eq '580'; # sigh... + + # See what is wanted. + my $action_wanted = ( $arg =~ /a/ ) ? 1 : 0; + my $break_wanted = ( $arg =~ /b/ ) ? 1 : 0; + my $watch_wanted = ( $arg =~ /w/ ) ? 1 : 0; + + # Breaks and actions are found together, so we look in the same place + # for both. + if ( $break_wanted or $action_wanted ) { + + # Look in all the files with breakpoints... + for my $file ( keys %had_breakpoints ) { + + # Temporary switch to this file. + local *dbline = $main::{ '_<' . $file }; + + # Set up to look through the whole file. + my $max = $#dbline; + my $was; # Flag: did we print something + # in this file? + + # For each line in the file ... + for ( $i = 1 ; $i <= $max ; $i++ ) { + + # We've got something on this line. + if ( defined $dbline{$i} ) { + + # Print the header if we haven't. + print $OUT "$file:\n" unless $was++; + + # Print the line. + print $OUT " $i:\t", $dbline[$i]; + + # Pull out the condition and the action. + ( $stop, $action ) = split( /\0/, $dbline{$i} ); + + # Print the break if there is one and it's wanted. + print $OUT " break if (", $stop, ")\n" + if $stop + and $break_wanted; + + # Print the action if there is one and it's wanted. + print $OUT " action: ", $action, "\n" + if $action + and $action_wanted; + + # Quit if the user hit interrupt. + last if $signal; + } ## end if (defined $dbline{$i... + } ## end for ($i = 1 ; $i <= $max... + } ## end for my $file (keys %had_breakpoints) + } ## end if ($break_wanted or $action_wanted) + + # Look for breaks in not-yet-compiled subs: + if ( %postponed and $break_wanted ) { + print $OUT "Postponed breakpoints in subroutines:\n"; + my $subname; + for $subname ( keys %postponed ) { + print $OUT " $subname\t$postponed{$subname}\n"; + last if $signal; + } + } ## end if (%postponed and $break_wanted) + + # Find files that have not-yet-loaded breaks: + my @have = map { # Combined keys + keys %{ $postponed_file{$_} } + } keys %postponed_file; + + # If there are any, list them. + if ( @have and ( $break_wanted or $action_wanted ) ) { + print $OUT "Postponed breakpoints in files:\n"; + my ( $file, $line ); + + for $file ( keys %postponed_file ) { + my $db = $postponed_file{$file}; + print $OUT " $file:\n"; + for $line ( sort { $a <=> $b } keys %$db ) { + print $OUT " $line:\n"; + my ( $stop, $action ) = split( /\0/, $$db{$line} ); + print $OUT " break if (", $stop, ")\n" + if $stop + and $break_wanted; + print $OUT " action: ", $action, "\n" + if $action + and $action_wanted; + last if $signal; + } ## end for $line (sort { $a <=>... + last if $signal; + } ## end for $file (keys %postponed_file) + } ## end if (@have and ($break_wanted... + if ( %break_on_load and $break_wanted ) { + print $OUT "Breakpoints on load:\n"; + my $file; + for $file ( keys %break_on_load ) { + print $OUT " $file\n"; + last if $signal; + } + } ## end if (%break_on_load and... + if ($watch_wanted) { + if ( $trace & 2 ) { + print $OUT "Watch-expressions:\n" if @to_watch; + for my $expr (@to_watch) { + print $OUT " $expr\n"; + last if $signal; + } + } ## end if ($trace & 2) + } ## end if ($watch_wanted) +} ## end sub cmd_L + +=head3 C<cmd_M> - list modules (command) + +Just call C<list_modules>. + +=cut + +sub cmd_M { + &list_modules(); +} + +=head3 C<cmd_o> - options (command) + +If this is just C<o> by itself, we list the current settings via +C<dump_option>. If there's a nonblank value following it, we pass that on to +C<parse_options> for processing. + +=cut + +sub cmd_o { + my $cmd = shift; + my $opt = shift || ''; # opt[=val] + + # Nonblank. Try to parse and process. + if ( $opt =~ /^(\S.*)/ ) { + &parse_options($1); + } + + # Blank. List the current option settings. + else { + for (@options) { + &dump_option($_); + } + } +} ## end sub cmd_o + +=head3 C<cmd_O> - nonexistent in 5.8.x (command) + +Advises the user that the O command has been renamed. + +=cut + +sub cmd_O { + print $OUT "The old O command is now the o command.\n"; # hint + print $OUT "Use 'h' to get current command help synopsis or\n"; # + print $OUT "use 'o CommandSet=pre580' to revert to old usage\n"; # +} + +=head3 C<cmd_v> - view window (command) + +Uses the C<$preview> variable set in the second C<BEGIN> block (q.v.) to +move back a few lines to list the selected line in context. Uses C<cmd_l> +to do the actual listing after figuring out the range of line to request. + +=cut + +sub cmd_v { + my $cmd = shift; + my $line = shift; + + # Extract the line to list around. (Astute readers will have noted that + # this pattern will match whether or not a numeric line is specified, + # which means that we'll always enter this loop (though a non-numeric + # argument results in no action at all)). + if ( $line =~ /^(\d*)$/ ) { + + # Total number of lines to list (a windowful). + $incr = $window - 1; + + # Set the start to the argument given (if there was one). + $start = $1 if $1; + + # Back up by the context amount. + $start -= $preview; + + # Put together a linespec that cmd_l will like. + $line = $start . '-' . ( $start + $incr ); + + # List the lines. + &cmd_l( 'l', $line ); + } ## end if ($line =~ /^(\d*)$/) +} ## end sub cmd_v + +=head3 C<cmd_w> - add a watch expression (command) + +The 5.8 version of this command adds a watch expression if one is specified; +it does nothing if entered with no operands. + +We extract the expression, save it, evaluate it in the user's context, and +save the value. We'll re-evaluate it each time the debugger passes a line, +and will stop (see the code at the top of the command loop) if the value +of any of the expressions changes. + +=cut + +sub cmd_w { + my $cmd = shift; + + # Null expression if no arguments. + my $expr = shift || ''; + + # If expression is not null ... + if ( $expr =~ /^(\S.*)/ ) { + + # ... save it. + push @to_watch, $expr; + + # Parameterize DB::eval and call it to get the expression's value + # in the user's context. This version can handle expressions which + # return a list value. + $evalarg = $expr; + my ($val) = join( ' ', &eval ); + $val = ( defined $val ) ? "'$val'" : 'undef'; + + # Save the current value of the expression. + push @old_watch, $val; + + # We are now watching expressions. + $trace |= 2; + } ## end if ($expr =~ /^(\S.*)/) + + # You have to give one to get one. + else { + print $OUT "Adding a watch-expression requires an expression\n"; # hint + } +} ## end sub cmd_w + +=head3 C<cmd_W> - delete watch expressions (command) + +This command accepts either a watch expression to be removed from the list +of watch expressions, or C<*> to delete them all. + +If C<*> is specified, we simply empty the watch expression list and the +watch expression value list. We also turn off the bit that says we've got +watch expressions. + +If an expression (or partial expression) is specified, we pattern-match +through the expressions and remove the ones that match. We also discard +the corresponding values. If no watch expressions are left, we turn off +the I<watching expressions> bit. + +=cut + +sub cmd_W { + my $cmd = shift; + my $expr = shift || ''; + + # Delete them all. + if ( $expr eq '*' ) { + + # Not watching now. + $trace &= ~2; + + print $OUT "Deleting all watch expressions ...\n"; + + # And all gone. + @to_watch = @old_watch = (); + } + + # Delete one of them. + elsif ( $expr =~ /^(\S.*)/ ) { + + # Where we are in the list. + my $i_cnt = 0; + + # For each expression ... + foreach (@to_watch) { + my $val = $to_watch[$i_cnt]; + + # Does this one match the command argument? + if ( $val eq $expr ) { # =~ m/^\Q$i$/) { + # Yes. Turn it off, and its value too. + splice( @to_watch, $i_cnt, 1 ); + splice( @old_watch, $i_cnt, 1 ); + } + $i_cnt++; + } ## end foreach (@to_watch) + + # We don't bother to turn watching off because + # a) we don't want to stop calling watchfunction() it it exists + # b) foreach over a null list doesn't do anything anyway + + } ## end elsif ($expr =~ /^(\S.*)/) + + # No command arguments entered. + else { + print $OUT + "Deleting a watch-expression requires an expression, or '*' for all\n" + ; # hint + } +} ## end sub cmd_W + +### END of the API section + +=head1 SUPPORT ROUTINES + +These are general support routines that are used in a number of places +throughout the debugger. + +=head2 save + +save() saves the user's versions of globals that would mess us up in C<@saved>, +and installs the versions we like better. + +=cut + +sub save { + + # Save eval failure, command failure, extended OS error, output field + # separator, input record separator, output record separator and + # the warning setting. + @saved = ( $@, $!, $^E, $,, $/, $\, $^W ); + + $, = ""; # output field separator is null string + $/ = "\n"; # input record separator is newline + $\ = ""; # output record separator is null string + $^W = 0; # warnings are off +} ## end sub save + +=head2 C<print_lineinfo> - show where we are now + +print_lineinfo prints whatever it is that it is handed; it prints it to the +C<$LINEINFO> filehandle instead of just printing it to STDOUT. This allows +us to feed line information to a slave editor without messing up the +debugger output. + +=cut + +sub print_lineinfo { + + # Make the terminal sensible if we're not the primary debugger. + resetterm(1) if $LINEINFO eq $OUT and $term_pid != $$; + local $\ = ''; + local $, = ''; + print $LINEINFO @_; +} ## end sub print_lineinfo + +=head2 C<postponed_sub> + +Handles setting postponed breakpoints in subroutines once they're compiled. +For breakpoints, we use C<DB::find_sub> to locate the source file and line +range for the subroutine, then mark the file as having a breakpoint, +temporarily switch the C<*dbline> glob over to the source file, and then +search the given range of lines to find a breakable line. If we find one, +we set the breakpoint on it, deleting the breakpoint from C<%postponed>. + +=cut + +# The following takes its argument via $evalarg to preserve current @_ + +sub postponed_sub { + + # Get the subroutine name. + my $subname = shift; + + # If this is a 'break +<n> if <condition>' ... + if ( $postponed{$subname} =~ s/^break\s([+-]?\d+)\s+if\s// ) { + + # If there's no offset, use '+0'. + my $offset = $1 || 0; + + # find_sub's value is 'fullpath-filename:start-stop'. It's + # possible that the filename might have colons in it too. + my ( $file, $i ) = ( find_sub($subname) =~ /^(.*):(\d+)-.*$/ ); + if ($i) { + + # We got the start line. Add the offset '+<n>' from + # $postponed{subname}. + $i += $offset; + + # Switch to the file this sub is in, temporarily. + local *dbline = $main::{ '_<' . $file }; + + # No warnings, please. + local $^W = 0; # != 0 is magical below + + # This file's got a breakpoint in it. + $had_breakpoints{$file} |= 1; + + # Last line in file. + my $max = $#dbline; + + # Search forward until we hit a breakable line or get to + # the end of the file. + ++$i until $dbline[$i] != 0 or $i >= $max; + + # Copy the breakpoint in and delete it from %postponed. + $dbline{$i} = delete $postponed{$subname}; + } ## end if ($i) + + # find_sub didn't find the sub. + else { + local $\ = ''; + print $OUT "Subroutine $subname not found.\n"; + } + return; + } ## end if ($postponed{$subname... + elsif ( $postponed{$subname} eq 'compile' ) { $signal = 1 } + + #print $OUT "In postponed_sub for `$subname'.\n"; +} ## end sub postponed_sub + +=head2 C<postponed> + +Called after each required file is compiled, but before it is executed; +also called if the name of a just-compiled subroutine is a key of +C<%postponed>. Propagates saved breakpoints (from C<b compile>, C<b load>, +etc.) into the just-compiled code. + +If this is a C<require>'d file, the incoming parameter is the glob +C<*{"_<$filename"}>, with C<$filename> the name of the C<require>'d file. + +If it's a subroutine, the incoming parameter is the subroutine name. + +=cut + +sub postponed { + + # If there's a break, process it. + if ($ImmediateStop) { + + # Right, we've stopped. Turn it off. + $ImmediateStop = 0; + + # Enter the command loop when DB::DB gets called. + $signal = 1; + } + + # If this is a subroutine, let postponed_sub() deal with it. + return &postponed_sub unless ref \$_[0] eq 'GLOB'; + + # Not a subroutine. Deal with the file. + local *dbline = shift; + my $filename = $dbline; + $filename =~ s/^_<//; + local $\ = ''; + $signal = 1, print $OUT "'$filename' loaded...\n" + if $break_on_load{$filename}; + print_lineinfo( ' ' x $stack_depth, "Package $filename.\n" ) if $frame; + + # Do we have any breakpoints to put in this file? + return unless $postponed_file{$filename}; + + # Yes. Mark this file as having breakpoints. + $had_breakpoints{$filename} |= 1; + + # "Cannot be done: unsufficient magic" - we can't just put the + # breakpoints saved in %postponed_file into %dbline by assigning + # the whole hash; we have to do it one item at a time for the + # breakpoints to be set properly. + #%dbline = %{$postponed_file{$filename}}; + + # Set the breakpoints, one at a time. + my $key; + + for $key ( keys %{ $postponed_file{$filename} } ) { + + # Stash the saved breakpoint into the current file's magic line array. + $dbline{$key} = ${ $postponed_file{$filename} }{$key}; + } + + # This file's been compiled; discard the stored breakpoints. + delete $postponed_file{$filename}; + +} ## end sub postponed + +=head2 C<dumpit> + +C<dumpit> is the debugger's wrapper around dumpvar.pl. + +It gets a filehandle (to which C<dumpvar.pl>'s output will be directed) and +a reference to a variable (the thing to be dumped) as its input. + +The incoming filehandle is selected for output (C<dumpvar.pl> is printing to +the currently-selected filehandle, thank you very much). The current +values of the package globals C<$single> and C<$trace> are backed up in +lexicals, and they are turned off (this keeps the debugger from trying +to single-step through C<dumpvar.pl> (I think.)). C<$frame> is localized to +preserve its current value and it is set to zero to prevent entry/exit +messages from printing, and C<$doret> is localized as well and set to -2 to +prevent return values from being shown. + +C<dumpit()> then checks to see if it needs to load C<dumpvar.pl> and +tries to load it (note: if you have a C<dumpvar.pl> ahead of the +installed version in C<@INC>, yours will be used instead. Possible security +problem?). + +It then checks to see if the subroutine C<main::dumpValue> is now defined +(it should have been defined by C<dumpvar.pl>). If it has, C<dumpit()> +localizes the globals necessary for things to be sane when C<main::dumpValue()> +is called, and picks up the variable to be dumped from the parameter list. + +It checks the package global C<%options> to see if there's a C<dumpDepth> +specified. If not, -1 is assumed; if so, the supplied value gets passed on to +C<dumpvar.pl>. This tells C<dumpvar.pl> where to leave off when dumping a +structure: -1 means dump everything. + +C<dumpValue()> is then called if possible; if not, C<dumpit()>just prints a +warning. + +In either case, C<$single>, C<$trace>, C<$frame>, and C<$doret> are restored +and we then return to the caller. + +=cut + +sub dumpit { + + # Save the current output filehandle and switch to the one + # passed in as the first parameter. + local ($savout) = select(shift); + + # Save current settings of $single and $trace, and then turn them off. + my $osingle = $single; + my $otrace = $trace; + $single = $trace = 0; + + # XXX Okay, what do $frame and $doret do, again? + local $frame = 0; + local $doret = -2; + + # Load dumpvar.pl unless we've already got the sub we need from it. + unless ( defined &main::dumpValue ) { + do 'dumpvar.pl' or die $@; + } + + # If the load succeeded (or we already had dumpvalue()), go ahead + # and dump things. + if ( defined &main::dumpValue ) { + local $\ = ''; + local $, = ''; + local $" = ' '; + my $v = shift; + my $maxdepth = shift || $option{dumpDepth}; + $maxdepth = -1 unless defined $maxdepth; # -1 means infinite depth + &main::dumpValue( $v, $maxdepth ); + } ## end if (defined &main::dumpValue) + + # Oops, couldn't load dumpvar.pl. + else { + local $\ = ''; + print $OUT "dumpvar.pl not available.\n"; + } + + # Reset $single and $trace to their old values. + $single = $osingle; + $trace = $otrace; + + # Restore the old filehandle. + select($savout); +} ## end sub dumpit + +=head2 C<print_trace> + +C<print_trace>'s job is to print a stack trace. It does this via the +C<dump_trace> routine, which actually does all the ferreting-out of the +stack trace data. C<print_trace> takes care of formatting it nicely and +printing it to the proper filehandle. + +Parameters: + +=over 4 + +=item * + +The filehandle to print to. + +=item * + +How many frames to skip before starting trace. + +=item * + +How many frames to print. + +=item * + +A flag: if true, print a I<short> trace without filenames, line numbers, or arguments + +=back + +The original comment below seems to be noting that the traceback may not be +correct if this routine is called in a tied method. + +=cut + +# Tied method do not create a context, so may get wrong message: + +sub print_trace { + local $\ = ''; + my $fh = shift; + + # If this is going to a slave editor, but we're not the primary + # debugger, reset it first. + resetterm(1) + if $fh eq $LINEINFO # slave editor + and $LINEINFO eq $OUT # normal output + and $term_pid != $$; # not the primary + + # Collect the actual trace information to be formatted. + # This is an array of hashes of subroutine call info. + my @sub = dump_trace( $_[0] + 1, $_[1] ); + + # Grab the "short report" flag from @_. + my $short = $_[2]; # Print short report, next one for sub name + + # Run through the traceback info, format it, and print it. + my $s; + for ( $i = 0 ; $i <= $#sub ; $i++ ) { + + # Drop out if the user has lost interest and hit control-C. + last if $signal; + + # Set the separator so arrys print nice. + local $" = ', '; + + # Grab and stringify the arguments if they are there. + my $args = + defined $sub[$i]{args} + ? "(@{ $sub[$i]{args} })" + : ''; + + # Shorten them up if $maxtrace says they're too long. + $args = ( substr $args, 0, $maxtrace - 3 ) . '...' + if length $args > $maxtrace; + + # Get the file name. + my $file = $sub[$i]{file}; + + # Put in a filename header if short is off. + $file = $file eq '-e' ? $file : "file `$file'" unless $short; + + # Get the actual sub's name, and shorten to $maxtrace's requirement. + $s = $sub[$i]{sub}; + $s = ( substr $s, 0, $maxtrace - 3 ) . '...' if length $s > $maxtrace; + + # Short report uses trimmed file and sub names. + if ($short) { + my $sub = @_ >= 4 ? $_[3] : $s; + print $fh "$sub[$i]{context}=$sub$args from $file:$sub[$i]{line}\n"; + } ## end if ($short) + + # Non-short report includes full names. + else { + print $fh "$sub[$i]{context} = $s$args" + . " called from $file" + . " line $sub[$i]{line}\n"; + } + } ## end for ($i = 0 ; $i <= $#sub... +} ## end sub print_trace + +=head2 dump_trace(skip[,count]) + +Actually collect the traceback information available via C<caller()>. It does +some filtering and cleanup of the data, but mostly it just collects it to +make C<print_trace()>'s job easier. + +C<skip> defines the number of stack frames to be skipped, working backwards +from the most current. C<count> determines the total number of frames to +be returned; all of them (well, the first 10^9) are returned if C<count> +is omitted. + +This routine returns a list of hashes, from most-recent to least-recent +stack frame. Each has the following keys and values: + +=over 4 + +=item * C<context> - C<.> (null), C<$> (scalar), or C<@> (array) + +=item * C<sub> - subroutine name, or C<eval> information + +=item * C<args> - undef, or a reference to an array of arguments + +=item * C<file> - the file in which this item was defined (if any) + +=item * C<line> - the line on which it was defined + +=back + +=cut + +sub dump_trace { + + # How many levels to skip. + my $skip = shift; + + # How many levels to show. (1e9 is a cheap way of saying "all of them"; + # it's unlikely that we'll have more than a billion stack frames. If you + # do, you've got an awfully big machine...) + my $count = shift || 1e9; + + # We increment skip because caller(1) is the first level *back* from + # the current one. Add $skip to the count of frames so we have a + # simple stop criterion, counting from $skip to $count+$skip. + $skip++; + $count += $skip; + + # These variables are used to capture output from caller(); + my ( $p, $file, $line, $sub, $h, $context ); + + my ( $e, $r, @a, @sub, $args ); + + # XXX Okay... why'd we do that? + my $nothard = not $frame & 8; + local $frame = 0; + + # Do not want to trace this. + my $otrace = $trace; + $trace = 0; + + # Start out at the skip count. + # If we haven't reached the number of frames requested, and caller() is + # still returning something, stay in the loop. (If we pass the requested + # number of stack frames, or we run out - caller() returns nothing - we + # quit. + # Up the stack frame index to go back one more level each time. + for ( + $i = $skip ; + $i < $count + and ( $p, $file, $line, $sub, $h, $context, $e, $r ) = caller($i) ; + $i++ + ) + { + + # Go through the arguments and save them for later. + @a = (); + for $arg (@args) { + my $type; + if ( not defined $arg ) { # undefined parameter + push @a, "undef"; + } + + elsif ( $nothard and tied $arg ) { # tied parameter + push @a, "tied"; + } + elsif ( $nothard and $type = ref $arg ) { # reference + push @a, "ref($type)"; + } + else { # can be stringified + local $_ = + "$arg"; # Safe to stringify now - should not call f(). + + # Backslash any single-quotes or backslashes. + s/([\'\\])/\\$1/g; + + # Single-quote it unless it's a number or a colon-separated + # name. + s/(.*)/'$1'/s + unless /^(?: -?[\d.]+ | \*[\w:]* )$/x; + + # Turn high-bit characters into meta-whatever. + s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg; + + # Turn control characters into ^-whatever. + s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg; + + push( @a, $_ ); + } ## end else [ if (not defined $arg) + } ## end for $arg (@args) + + # If context is true, this is array (@)context. + # If context is false, this is scalar ($) context. + # If neither, context isn't defined. (This is apparently a 'can't + # happen' trap.) + $context = $context ? '@' : ( defined $context ? "\$" : '.' ); + + # if the sub has args ($h true), make an anonymous array of the + # dumped args. + $args = $h ? [@a] : undef; + + # remove trailing newline-whitespace-semicolon-end of line sequence + # from the eval text, if any. + $e =~ s/\n\s*\;\s*\Z// if $e; + + # Escape backslashed single-quotes again if necessary. + $e =~ s/([\\\'])/\\$1/g if $e; + + # if the require flag is true, the eval text is from a require. + if ($r) { + $sub = "require '$e'"; + } + + # if it's false, the eval text is really from an eval. + elsif ( defined $r ) { + $sub = "eval '$e'"; + } + + # If the sub is '(eval)', this is a block eval, meaning we don't + # know what the eval'ed text actually was. + elsif ( $sub eq '(eval)' ) { + $sub = "eval {...}"; + } + + # Stick the collected information into @sub as an anonymous hash. + push( + @sub, + { + context => $context, + sub => $sub, + args => $args, + file => $file, + line => $line + } + ); + + # Stop processing frames if the user hit control-C. + last if $signal; + } ## end for ($i = $skip ; $i < ... + + # Restore the trace value again. + $trace = $otrace; + @sub; +} ## end sub dump_trace + +=head2 C<action()> + +C<action()> takes input provided as the argument to an add-action command, +either pre- or post-, and makes sure it's a complete command. It doesn't do +any fancy parsing; it just keeps reading input until it gets a string +without a trailing backslash. + +=cut + +sub action { + my $action = shift; + + while ( $action =~ s/\\$// ) { + + # We have a backslash on the end. Read more. + $action .= &gets; + } ## end while ($action =~ s/\\$//) + + # Return the assembled action. + $action; +} ## end sub action + +=head2 unbalanced + +This routine mostly just packages up a regular expression to be used +to check that the thing it's being matched against has properly-matched +curly braces. + +Of note is the definition of the C<$balanced_brace_re> global via C<||=>, which +speeds things up by only creating the qr//'ed expression once; if it's +already defined, we don't try to define it again. A speed hack. + +=cut + +sub unbalanced { + + # I hate using globals! + $balanced_brace_re ||= qr{ + ^ \{ + (?: + (?> [^{}] + ) # Non-parens without backtracking + | + (??{ $balanced_brace_re }) # Group with matching parens + ) * + \} $ + }x; + return $_[0] !~ m/$balanced_brace_re/; +} ## end sub unbalanced + +=head2 C<gets()> + +C<gets()> is a primitive (very primitive) routine to read continuations. +It was devised for reading continuations for actions. +it just reads more input with C<readline()> and returns it. + +=cut + +sub gets { + &readline("cont: "); +} + +=head2 C<DB::system()> - handle calls to<system()> without messing up the debugger + +The C<system()> function assumes that it can just go ahead and use STDIN and +STDOUT, but under the debugger, we want it to use the debugger's input and +outout filehandles. + +C<DB::system()> socks away the program's STDIN and STDOUT, and then substitutes +the debugger's IN and OUT filehandles for them. It does the C<system()> call, +and then puts everything back again. + +=cut + +sub system { + + # We save, change, then restore STDIN and STDOUT to avoid fork() since + # some non-Unix systems can do system() but have problems with fork(). + open( SAVEIN, "<&STDIN" ) || &warn("Can't save STDIN"); + open( SAVEOUT, ">&STDOUT" ) || &warn("Can't save STDOUT"); + open( STDIN, "<&IN" ) || &warn("Can't redirect STDIN"); + open( STDOUT, ">&OUT" ) || &warn("Can't redirect STDOUT"); + + # XXX: using csh or tcsh destroys sigint retvals! + system(@_); + open( STDIN, "<&SAVEIN" ) || &warn("Can't restore STDIN"); + open( STDOUT, ">&SAVEOUT" ) || &warn("Can't restore STDOUT"); + close(SAVEIN); + close(SAVEOUT); + + # most of the $? crud was coping with broken cshisms + if ( $? >> 8 ) { + &warn( "(Command exited ", ( $? >> 8 ), ")\n" ); + } + elsif ($?) { + &warn( + "(Command died of SIG#", + ( $? & 127 ), + ( ( $? & 128 ) ? " -- core dumped" : "" ), + ")", "\n" + ); + } ## end elsif ($?) + + return $?; + +} ## end sub system + +=head1 TTY MANAGEMENT + +The subs here do some of the terminal management for multiple debuggers. + +=head2 setterm + +Top-level function called when we want to set up a new terminal for use +by the debugger. + +If the C<noTTY> debugger option was set, we'll either use the terminal +supplied (the value of the C<noTTY> option), or we'll use C<Term::Rendezvous> +to find one. If we're a forked debugger, we call C<resetterm> to try to +get a whole new terminal if we can. + +In either case, we set up the terminal next. If the C<ReadLine> option was +true, we'll get a C<Term::ReadLine> object for the current terminal and save +the appropriate attributes. We then + +=cut + +sub setterm { + + # Load Term::Readline, but quietly; don't debug it and don't trace it. + local $frame = 0; + local $doret = -2; + eval { require Term::ReadLine } or die $@; + + # If noTTY is set, but we have a TTY name, go ahead and hook up to it. + if ($notty) { + if ($tty) { + my ( $i, $o ) = split $tty, /,/; + $o = $i unless defined $o; + open( IN, "<$i" ) or die "Cannot open TTY `$i' for read: $!"; + open( OUT, ">$o" ) or die "Cannot open TTY `$o' for write: $!"; + $IN = \*IN; + $OUT = \*OUT; + my $sel = select($OUT); + $| = 1; + select($sel); + } ## end if ($tty) + + # We don't have a TTY - try to find one via Term::Rendezvous. + else { + eval "require Term::Rendezvous;" or die; + + # See if we have anything to pass to Term::Rendezvous. + # Use $HOME/.perldbtty$$ if not. + my $rv = $ENV{PERLDB_NOTTY} || "$ENV{HOME}/.perldbtty$$"; + + # Rendezvous and get the filehandles. + my $term_rv = new Term::Rendezvous $rv; + $IN = $term_rv->IN; + $OUT = $term_rv->OUT; + } ## end else [ if ($tty) + } ## end if ($notty) + + # We're a daughter debugger. Try to fork off another TTY. + if ( $term_pid eq '-1' ) { # In a TTY with another debugger + resetterm(2); + } + + # If we shouldn't use Term::ReadLine, don't. + if ( !$rl ) { + $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT; + } + + # We're using Term::ReadLine. Get all the attributes for this terminal. + else { + $term = new Term::ReadLine 'perldb', $IN, $OUT; + + $rl_attribs = $term->Attribs; + $rl_attribs->{basic_word_break_characters} .= '-:+/*,[])}' + if defined $rl_attribs->{basic_word_break_characters} + and index( $rl_attribs->{basic_word_break_characters}, ":" ) == -1; + $rl_attribs->{special_prefixes} = '$@&%'; + $rl_attribs->{completer_word_break_characters} .= '$@&%'; + $rl_attribs->{completion_function} = \&db_complete; + } ## end else [ if (!$rl) + + # Set up the LINEINFO filehandle. + $LINEINFO = $OUT unless defined $LINEINFO; + $lineinfo = $console unless defined $lineinfo; + + $term->MinLine(2); + + &load_hist(); + + if ( $term->Features->{setHistory} and "@hist" ne "?" ) { + $term->SetHistory(@hist); + } + + # XXX Ornaments are turned on unconditionally, which is not + # always a good thing. + ornaments($ornaments) if defined $ornaments; + $term_pid = $$; +} ## end sub setterm + +sub load_hist { + $histfile //= option_val("HistFile", undef); + return unless defined $histfile; + open my $fh, "<", $histfile or return; + local $/ = "\n"; + @hist = (); + while (<$fh>) { + chomp; + push @hist, $_; + } + close $fh; +} + +sub save_hist { + return unless defined $histfile; + eval { require File::Path } or return; + eval { require File::Basename } or return; + File::Path::mkpath(File::Basename::dirname($histfile)); + open my $fh, ">", $histfile or die "Could not open '$histfile': $!"; + $histsize //= option_val("HistSize",100); + my @copy = grep { $_ ne '?' } @hist; + my $start = scalar(@copy) > $histsize ? scalar(@copy)-$histsize : 0; + for ($start .. $#copy) { + print $fh "$copy[$_]\n"; + } + close $fh or die "Could not write '$histfile': $!"; +} + +=head1 GET_FORK_TTY EXAMPLE FUNCTIONS + +When the process being debugged forks, or the process invokes a command +via C<system()> which starts a new debugger, we need to be able to get a new +C<IN> and C<OUT> filehandle for the new debugger. Otherwise, the two processes +fight over the terminal, and you can never quite be sure who's going to get the +input you're typing. + +C<get_fork_TTY> is a glob-aliased function which calls the real function that +is tasked with doing all the necessary operating system mojo to get a new +TTY (and probably another window) and to direct the new debugger to read and +write there. + +The debugger provides C<get_fork_TTY> functions which work for X Windows, +OS/2, and Mac OS X. Other systems are not supported. You are encouraged +to write C<get_fork_TTY> functions which work for I<your> platform +and contribute them. + +=head3 C<xterm_get_fork_TTY> + +This function provides the C<get_fork_TTY> function for X windows. If a +program running under the debugger forks, a new <xterm> window is opened and +the subsidiary debugger is directed there. + +The C<open()> call is of particular note here. We have the new C<xterm> +we're spawning route file number 3 to STDOUT, and then execute the C<tty> +command (which prints the device name of the TTY we'll want to use for input +and output to STDOUT, then C<sleep> for a very long time, routing this output +to file number 3. This way we can simply read from the <XT> filehandle (which +is STDOUT from the I<commands> we ran) to get the TTY we want to use. + +Only works if C<xterm> is in your path and C<$ENV{DISPLAY}>, etc. are +properly set up. + +=cut + +sub xterm_get_fork_TTY { + ( my $name = $0 ) =~ s,^.*[/\\],,s; + open XT, +qq[3>&1 xterm -title "Daughter Perl debugger $pids $name" -e sh -c 'tty 1>&3;\ + sleep 10000000' |]; + + # Get the output from 'tty' and clean it up a little. + my $tty = <XT>; + chomp $tty; + + $pidprompt = ''; # Shown anyway in titlebar + + # We need $term defined or we can not switch to the newly created xterm + if ($tty ne '' && !defined $term) { + eval { require Term::ReadLine } or die $@; + if ( !$rl ) { + $term = new Term::ReadLine::Stub 'perldb', $IN, $OUT; + } + else { + $term = new Term::ReadLine 'perldb', $IN, $OUT; + } + } + # There's our new TTY. + return $tty; +} ## end sub xterm_get_fork_TTY + +=head3 C<os2_get_fork_TTY> + +XXX It behooves an OS/2 expert to write the necessary documentation for this! + +=cut + +# This example function resets $IN, $OUT itself +my $c_pipe = 0; +sub os2_get_fork_TTY { # A simplification of the following (and works without): + local $\ = ''; + ( my $name = $0 ) =~ s,^.*[/\\],,s; + my %opt = ( title => "Daughter Perl debugger $pids $name", + ($rl ? (read_by_key => 1) : ()) ); + require OS2::Process; + my ($in, $out, $pid) = eval { OS2::Process::io_term(related => 0, %opt) } + or return; + $pidprompt = ''; # Shown anyway in titlebar + reset_IN_OUT($in, $out); + $tty = '*reset*'; + return ''; # Indicate that reset_IN_OUT is called +} ## end sub os2_get_fork_TTY + +=head3 C<macosx_get_fork_TTY> + +The Mac OS X version uses AppleScript to tell Terminal.app to create +a new window. + +=cut + +# Notes about Terminal.app's AppleScript support, +# (aka things that might break in future OS versions). +# +# The "do script" command doesn't return a reference to the new window +# it creates, but since it appears frontmost and windows are enumerated +# front to back, we can use "first window" === "window 1". +# +# Since "do script" is implemented by supplying the argument (plus a +# return character) as terminal input, there's a potential race condition +# where the debugger could beat the shell to reading the command. +# To prevent this, we wait for the screen to clear before proceeding. +# +# 10.3 and 10.4: +# There's no direct accessor for the tty device name, so we fiddle +# with the window title options until it says what we want. +# +# 10.5: +# There _is_ a direct accessor for the tty device name, _and_ there's +# a new possible component of the window title (the name of the settings +# set). A separate version is needed. + +my @script_versions= + + ([237, <<'__LEOPARD__'], +tell application "Terminal" + do script "clear;exec sleep 100000" + tell first tab of first window + copy tty to thetty + set custom title to "forked perl debugger" + set title displays custom title to true + repeat while (length of first paragraph of (get contents)) > 0 + delay 0.1 + end repeat + end tell +end tell +thetty +__LEOPARD__ + + [100, <<'__JAGUAR_TIGER__'], +tell application "Terminal" + do script "clear;exec sleep 100000" + tell first window + set title displays shell path to false + set title displays window size to false + set title displays file name to false + set title displays device name to true + set title displays custom title to true + set custom title to "" + copy "/dev/" & name to thetty + set custom title to "forked perl debugger" + repeat while (length of first paragraph of (get contents)) > 0 + delay 0.1 + end repeat + end tell +end tell +thetty +__JAGUAR_TIGER__ + +); + +sub macosx_get_fork_TTY +{ + my($version,$script,$pipe,$tty); + + return unless $version=$ENV{TERM_PROGRAM_VERSION}; + foreach my $entry (@script_versions) { + if ($version>=$entry->[0]) { + $script=$entry->[1]; + last; + } + } + return unless defined($script); + return unless open($pipe,'-|','/usr/bin/osascript','-e',$script); + $tty=readline($pipe); + close($pipe); + return unless defined($tty) && $tty =~ m(^/dev/); + chomp $tty; + return $tty; +} + +=head2 C<create_IN_OUT($flags)> + +Create a new pair of filehandles, pointing to a new TTY. If impossible, +try to diagnose why. + +Flags are: + +=over 4 + +=item * 1 - Don't know how to create a new TTY. + +=item * 2 - Debugger has forked, but we can't get a new TTY. + +=item * 4 - standard debugger startup is happening. + +=back + +=cut + +sub create_IN_OUT { # Create a window with IN/OUT handles redirected there + + # If we know how to get a new TTY, do it! $in will have + # the TTY name if get_fork_TTY works. + my $in = &get_fork_TTY if defined &get_fork_TTY; + + # It used to be that + $in = $fork_TTY if defined $fork_TTY; # Backward compatibility + + if ( not defined $in ) { + my $why = shift; + + # We don't know how. + print_help(<<EOP) if $why == 1; +I<#########> Forked, but do not know how to create a new B<TTY>. I<#########> +EOP + + # Forked debugger. + print_help(<<EOP) if $why == 2; +I<#########> Daughter session, do not know how to change a B<TTY>. I<#########> + This may be an asynchronous session, so the parent debugger may be active. +EOP + + # Note that both debuggers are fighting over the same input. + print_help(<<EOP) if $why != 4; + Since two debuggers fight for the same TTY, input is severely entangled. + +EOP + print_help(<<EOP); + I know how to switch the output to a different window in xterms, OS/2 + consoles, and Mac OS X Terminal.app only. For a manual switch, put the name + of the created I<TTY> in B<\$DB::fork_TTY>, or define a function + B<DB::get_fork_TTY()> returning this. + + On I<UNIX>-like systems one can get the name of a I<TTY> for the given window + by typing B<tty>, and disconnect the I<shell> from I<TTY> by B<sleep 1000000>. + +EOP + } ## end if (not defined $in) + elsif ( $in ne '' ) { + TTY($in); + } + else { + $console = ''; # Indicate no need to open-from-the-console + } + undef $fork_TTY; +} ## end sub create_IN_OUT + +=head2 C<resetterm> + +Handles rejiggering the prompt when we've forked off a new debugger. + +If the new debugger happened because of a C<system()> that invoked a +program under the debugger, the arrow between the old pid and the new +in the prompt has I<two> dashes instead of one. + +We take the current list of pids and add this one to the end. If there +isn't any list yet, we make one up out of the initial pid associated with +the terminal and our new pid, sticking an arrow (either one-dashed or +two dashed) in between them. + +If C<CreateTTY> is off, or C<resetterm> was called with no arguments, +we don't try to create a new IN and OUT filehandle. Otherwise, we go ahead +and try to do that. + +=cut + +sub resetterm { # We forked, so we need a different TTY + + # Needs to be passed to create_IN_OUT() as well. + my $in = shift; + + # resetterm(2): got in here because of a system() starting a debugger. + # resetterm(1): just forked. + my $systemed = $in > 1 ? '-' : ''; + + # If there's already a list of pids, add this to the end. + if ($pids) { + $pids =~ s/\]/$systemed->$$]/; + } + + # No pid list. Time to make one. + else { + $pids = "[$term_pid->$$]"; + } + + # The prompt we're going to be using for this debugger. + $pidprompt = $pids; + + # We now 0wnz this terminal. + $term_pid = $$; + + # Just return if we're not supposed to try to create a new TTY. + return unless $CreateTTY & $in; + + # Try to create a new IN/OUT pair. + create_IN_OUT($in); +} ## end sub resetterm + +=head2 C<readline> + +First, we handle stuff in the typeahead buffer. If there is any, we shift off +the next line, print a message saying we got it, add it to the terminal +history (if possible), and return it. + +If there's nothing in the typeahead buffer, check the command filehandle stack. +If there are any filehandles there, read from the last one, and return the line +if we got one. If not, we pop the filehandle off and close it, and try the +next one up the stack. + +If we've emptied the filehandle stack, we check to see if we've got a socket +open, and we read that and return it if we do. If we don't, we just call the +core C<readline()> and return its value. + +=cut + +sub readline { + + # Localize to prevent it from being smashed in the program being debugged. + local $.; + + # Pull a line out of the typeahead if there's stuff there. + if (@typeahead) { + + # How many lines left. + my $left = @typeahead; + + # Get the next line. + my $got = shift @typeahead; + + # Print a message saying we got input from the typeahead. + local $\ = ''; + print $OUT "auto(-$left)", shift, $got, "\n"; + + # Add it to the terminal history (if possible). + $term->AddHistory($got) + if length($got) > 1 + and defined $term->Features->{addHistory}; + return $got; + } ## end if (@typeahead) + + # We really need to read some input. Turn off entry/exit trace and + # return value printing. + local $frame = 0; + local $doret = -2; + + # If there are stacked filehandles to read from ... + while (@cmdfhs) { + + # Read from the last one in the stack. + my $line = CORE::readline( $cmdfhs[-1] ); + + # If we got a line ... + defined $line + ? ( print $OUT ">> $line" and return $line ) # Echo and return + : close pop @cmdfhs; # Pop and close + } ## end while (@cmdfhs) + + # Nothing on the filehandle stack. Socket? + if ( ref $OUT and UNIVERSAL::isa( $OUT, 'IO::Socket::INET' ) ) { + + # Send anyting we have to send. + $OUT->write( join( '', @_ ) ); + + # Receive anything there is to receive. + $stuff; + my $stuff = ''; + my $buf; + do { + $IN->recv( $buf = '', 2048 ); # XXX "what's wrong with sysread?" + # XXX Don't know. You tell me. + } while length $buf and ($stuff .= $buf) !~ /\n/; + + # What we got. + $stuff; + } ## end if (ref $OUT and UNIVERSAL::isa... + + # No socket. Just read from the terminal. + else { + $term->readline(@_); + } +} ## end sub readline + +=head1 OPTIONS SUPPORT ROUTINES + +These routines handle listing and setting option values. + +=head2 C<dump_option> - list the current value of an option setting + +This routine uses C<option_val> to look up the value for an option. +It cleans up escaped single-quotes and then displays the option and +its value. + +=cut + +sub dump_option { + my ( $opt, $val ) = @_; + $val = option_val( $opt, 'N/A' ); + $val =~ s/([\\\'])/\\$1/g; + printf $OUT "%20s = '%s'\n", $opt, $val; +} ## end sub dump_option + +sub options2remember { + foreach my $k (@RememberOnROptions) { + $option{$k} = option_val( $k, 'N/A' ); + } + return %option; +} + +=head2 C<option_val> - find the current value of an option + +This can't just be a simple hash lookup because of the indirect way that +the option values are stored. Some are retrieved by calling a subroutine, +some are just variables. + +You must supply a default value to be used in case the option isn't set. + +=cut + +sub option_val { + my ( $opt, $default ) = @_; + my $val; + + # Does this option exist, and is it a variable? + # If so, retrieve the value via the value in %optionVars. + if ( defined $optionVars{$opt} + and defined ${ $optionVars{$opt} } ) + { + $val = ${ $optionVars{$opt} }; + } + + # Does this option exist, and it's a subroutine? + # If so, call the subroutine via the ref in %optionAction + # and capture the value. + elsif ( defined $optionAction{$opt} + and defined &{ $optionAction{$opt} } ) + { + $val = &{ $optionAction{$opt} }(); + } + + # If there's an action or variable for the supplied option, + # but no value was set, use the default. + elsif (defined $optionAction{$opt} and not defined $option{$opt} + or defined $optionVars{$opt} and not defined ${ $optionVars{$opt} } ) + { + $val = $default; + } + + # Otherwise, do the simple hash lookup. + else { + $val = $option{$opt}; + } + + # If the value isn't defined, use the default. + # Then return whatever the value is. + $val = $default unless defined $val; + $val; +} ## end sub option_val + +=head2 C<parse_options> + +Handles the parsing and execution of option setting/displaying commands. + +An option entered by itself is assumed to be I<set me to 1> (the default value) +if the option is a boolean one. If not, the user is prompted to enter a valid +value or to query the current value (via C<option? >). + +If C<option=value> is entered, we try to extract a quoted string from the +value (if it is quoted). If it's not, we just use the whole value as-is. + +We load any modules required to service this option, and then we set it: if +it just gets stuck in a variable, we do that; if there's a subroutine to +handle setting the option, we call that. + +Finally, if we're running in interactive mode, we display the effect of the +user's command back to the terminal, skipping this if we're setting things +during initialization. + +=cut + +sub parse_options { + local ($_) = @_; + local $\ = ''; + + # These options need a value. Don't allow them to be clobbered by accident. + my %opt_needs_val = map { ( $_ => 1 ) } qw{ + dumpDepth arrayDepth hashDepth LineInfo maxTraceLen ornaments windowSize + pager quote ReadLine recallCommand RemotePort ShellBang TTY CommandSet + }; + + while (length) { + my $val_defaulted; + + # Clean off excess leading whitespace. + s/^\s+// && next; + + # Options are always all word characters, followed by a non-word + # separator. + s/^(\w+)(\W?)// or print( $OUT "Invalid option `$_'\n" ), last; + my ( $opt, $sep ) = ( $1, $2 ); + + # Make sure that such an option exists. + my $matches = grep( /^\Q$opt/ && ( $option = $_ ), @options ) + || grep( /^\Q$opt/i && ( $option = $_ ), @options ); + + print( $OUT "Unknown option `$opt'\n" ), next unless $matches; + print( $OUT "Ambiguous option `$opt'\n" ), next if $matches > 1; + my $val; + + # '?' as separator means query, but must have whitespace after it. + if ( "?" eq $sep ) { + print( $OUT "Option query `$opt?' followed by non-space `$_'\n" ), + last + if /^\S/; + + #&dump_option($opt); + } ## end if ("?" eq $sep) + + # Separator is whitespace (or just a carriage return). + # They're going for a default, which we assume is 1. + elsif ( $sep !~ /\S/ ) { + $val_defaulted = 1; + $val = "1"; # this is an evil default; make 'em set it! + } + + # Separator is =. Trying to set a value. + elsif ( $sep eq "=" ) { + + # If quoted, extract a quoted string. + if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) { + my $quote = $1; + ( $val = $2 ) =~ s/\\([$quote\\])/$1/g; + } + + # Not quoted. Use the whole thing. Warn about 'option='. + else { + s/^(\S*)//; + $val = $1; + print OUT qq(Option better cleared using $opt=""\n) + unless length $val; + } ## end else [ if (s/ (["']) ( (?: \\. | (?! \1 ) [^\\] )* ) \1 //x) + + } ## end elsif ($sep eq "=") + + # "Quoted" with [], <>, or {}. + else { #{ to "let some poor schmuck bounce on the % key in B<vi>." + my ($end) = + "\\" . substr( ")]>}$sep", index( "([<{", $sep ), 1 ); #} + s/^(([^\\$end]|\\[\\$end])*)$end($|\s+)// + or print( $OUT "Unclosed option value `$opt$sep$_'\n" ), last; + ( $val = $1 ) =~ s/\\([\\$end])/$1/g; + } ## end else [ if ("?" eq $sep) + + # Exclude non-booleans from getting set to 1 by default. + if ( $opt_needs_val{$option} && $val_defaulted ) { + my $cmd = ( $CommandSet eq '580' ) ? 'o' : 'O'; + print $OUT +"Option `$opt' is non-boolean. Use `$cmd $option=VAL' to set, `$cmd $option?' to query\n"; + next; + } ## end if ($opt_needs_val{$option... + + # Save the option value. + $option{$option} = $val if defined $val; + + # Load any module that this option requires. + eval qq{ + local \$frame = 0; + local \$doret = -2; + require '$optionRequire{$option}'; + 1; + } || die # XXX: shouldn't happen + if defined $optionRequire{$option} + && defined $val; + + # Set it. + # Stick it in the proper variable if it goes in a variable. + ${ $optionVars{$option} } = $val + if defined $optionVars{$option} + && defined $val; + + # Call the appropriate sub if it gets set via sub. + &{ $optionAction{$option} }($val) + if defined $optionAction{$option} + && defined &{ $optionAction{$option} } + && defined $val; + + # Not initialization - echo the value we set it to. + dump_option($option) unless $OUT eq \*STDERR; + } ## end while (length) +} ## end sub parse_options + +=head1 RESTART SUPPORT + +These routines are used to store (and restore) lists of items in environment +variables during a restart. + +=head2 set_list + +Set_list packages up items to be stored in a set of environment variables +(VAR_n, containing the number of items, and VAR_0, VAR_1, etc., containing +the values). Values outside the standard ASCII charset are stored by encoding +then as hexadecimal values. + +=cut + +sub set_list { + my ( $stem, @list ) = @_; + my $val; + + # VAR_n: how many we have. Scalar assignment gets the number of items. + $ENV{"${stem}_n"} = @list; + + # Grab each item in the list, escape the backslashes, encode the non-ASCII + # as hex, and then save in the appropriate VAR_0, VAR_1, etc. + for $i ( 0 .. $#list ) { + $val = $list[$i]; + $val =~ s/\\/\\\\/g; + $val =~ s/([\0-\37\177\200-\377])/"\\0x" . unpack('H2',$1)/eg; + $ENV{"${stem}_$i"} = $val; + } ## end for $i (0 .. $#list) +} ## end sub set_list + +=head2 get_list + +Reverse the set_list operation: grab VAR_n to see how many we should be getting +back, and then pull VAR_0, VAR_1. etc. back out. + +=cut + +sub get_list { + my $stem = shift; + my @list; + my $n = delete $ENV{"${stem}_n"}; + my $val; + for $i ( 0 .. $n - 1 ) { + $val = delete $ENV{"${stem}_$i"}; + $val =~ s/\\((\\)|0x(..))/ $2 ? $2 : pack('H2', $3) /ge; + push @list, $val; + } + @list; +} ## end sub get_list + +=head1 MISCELLANEOUS SIGNAL AND I/O MANAGEMENT + +=head2 catch() + +The C<catch()> subroutine is the essence of fast and low-impact. We simply +set an already-existing global scalar variable to a constant value. This +avoids allocating any memory possibly in the middle of something that will +get all confused if we do, particularly under I<unsafe signals>. + +=cut + +sub catch { + $signal = 1; + return; # Put nothing on the stack - malloc/free land! +} + +=head2 C<warn()> + +C<warn> emits a warning, by joining together its arguments and printing +them, with couple of fillips. + +If the composited message I<doesn't> end with a newline, we automatically +add C<$!> and a newline to the end of the message. The subroutine expects $OUT +to be set to the filehandle to be used to output warnings; it makes no +assumptions about what filehandles are available. + +=cut + +sub warn { + my ($msg) = join( "", @_ ); + $msg .= ": $!\n" unless $msg =~ /\n$/; + local $\ = ''; + print $OUT $msg; +} ## end sub warn + +=head1 INITIALIZATION TTY SUPPORT + +=head2 C<reset_IN_OUT> + +This routine handles restoring the debugger's input and output filehandles +after we've tried and failed to move them elsewhere. In addition, it assigns +the debugger's output filehandle to $LINEINFO if it was already open there. + +=cut + +sub reset_IN_OUT { + my $switch_li = $LINEINFO eq $OUT; + + # If there's a term and it's able to get a new tty, try to get one. + if ( $term and $term->Features->{newTTY} ) { + ( $IN, $OUT ) = ( shift, shift ); + $term->newTTY( $IN, $OUT ); + } + + # This term can't get a new tty now. Better luck later. + elsif ($term) { + &warn("Too late to set IN/OUT filehandles, enabled on next `R'!\n"); + } + + # Set the filehndles up as they were. + else { + ( $IN, $OUT ) = ( shift, shift ); + } + + # Unbuffer the output filehandle. + my $o = select $OUT; + $| = 1; + select $o; + + # Point LINEINFO to the same output filehandle if it was there before. + $LINEINFO = $OUT if $switch_li; +} ## end sub reset_IN_OUT + +=head1 OPTION SUPPORT ROUTINES + +The following routines are used to process some of the more complicated +debugger options. + +=head2 C<TTY> + +Sets the input and output filehandles to the specified files or pipes. +If the terminal supports switching, we go ahead and do it. If not, and +there's already a terminal in place, we save the information to take effect +on restart. + +If there's no terminal yet (for instance, during debugger initialization), +we go ahead and set C<$console> and C<$tty> to the file indicated. + +=cut + +sub TTY { + + if ( @_ and $term and $term->Features->{newTTY} ) { + + # This terminal supports switching to a new TTY. + # Can be a list of two files, or on string containing both names, + # comma-separated. + # XXX Should this perhaps be an assignment from @_? + my ( $in, $out ) = shift; + if ( $in =~ /,/ ) { + + # Split list apart if supplied. + ( $in, $out ) = split /,/, $in, 2; + } + else { + + # Use the same file for both input and output. + $out = $in; + } + + # Open file onto the debugger's filehandles, if you can. + open IN, $in or die "cannot open `$in' for read: $!"; + open OUT, ">$out" or die "cannot open `$out' for write: $!"; + + # Swap to the new filehandles. + reset_IN_OUT( \*IN, \*OUT ); + + # Save the setting for later. + return $tty = $in; + } ## end if (@_ and $term and $term... + + # Terminal doesn't support new TTY, or doesn't support readline. + # Can't do it now, try restarting. + &warn("Too late to set TTY, enabled on next `R'!\n") if $term and @_; + + # Useful if done through PERLDB_OPTS: + $console = $tty = shift if @_; + + # Return whatever the TTY is. + $tty or $console; +} ## end sub TTY + +=head2 C<noTTY> + +Sets the C<$notty> global, controlling whether or not the debugger tries to +get a terminal to read from. If called after a terminal is already in place, +we save the value to use it if we're restarted. + +=cut + +sub noTTY { + if ($term) { + &warn("Too late to set noTTY, enabled on next `R'!\n") if @_; + } + $notty = shift if @_; + $notty; +} ## end sub noTTY + +=head2 C<ReadLine> + +Sets the C<$rl> option variable. If 0, we use C<Term::ReadLine::Stub> +(essentially, no C<readline> processing on this I<terminal>). Otherwise, we +use C<Term::ReadLine>. Can't be changed after a terminal's in place; we save +the value in case a restart is done so we can change it then. + +=cut + +sub ReadLine { + if ($term) { + &warn("Too late to set ReadLine, enabled on next `R'!\n") if @_; + } + $rl = shift if @_; + $rl; +} ## end sub ReadLine + +=head2 C<RemotePort> + +Sets the port that the debugger will try to connect to when starting up. +If the terminal's already been set up, we can't do it, but we remember the +setting in case the user does a restart. + +=cut + +sub RemotePort { + if ($term) { + &warn("Too late to set RemotePort, enabled on next 'R'!\n") if @_; + } + $remoteport = shift if @_; + $remoteport; +} ## end sub RemotePort + +=head2 C<tkRunning> + +Checks with the terminal to see if C<Tk> is running, and returns true or +false. Returns false if the current terminal doesn't support C<readline>. + +=cut + +sub tkRunning { + if ( ${ $term->Features }{tkRunning} ) { + return $term->tkRunning(@_); + } + else { + local $\ = ''; + print $OUT "tkRunning not supported by current ReadLine package.\n"; + 0; + } +} ## end sub tkRunning + +=head2 C<NonStop> + +Sets nonstop mode. If a terminal's already been set up, it's too late; the +debugger remembers the setting in case you restart, though. + +=cut + +sub NonStop { + if ($term) { + &warn("Too late to set up NonStop mode, enabled on next `R'!\n") + if @_; + } + $runnonstop = shift if @_; + $runnonstop; +} ## end sub NonStop + +sub DollarCaretP { + if ($term) { + &warn("Some flag changes could not take effect until next 'R'!\n") + if @_; + } + $^P = parse_DollarCaretP_flags(shift) if @_; + expand_DollarCaretP_flags($^P); +} + +=head2 C<pager> + +Set up the C<$pager> variable. Adds a pipe to the front unless there's one +there already. + +=cut + +sub pager { + if (@_) { + $pager = shift; + $pager = "|" . $pager unless $pager =~ /^(\+?\>|\|)/; + } + $pager; +} ## end sub pager + +=head2 C<shellBang> + +Sets the shell escape command, and generates a printable copy to be used +in the help. + +=cut + +sub shellBang { + + # If we got an argument, meta-quote it, and add '\b' if it + # ends in a word character. + if (@_) { + $sh = quotemeta shift; + $sh .= "\\b" if $sh =~ /\w$/; + } + + # Generate the printable version for the help: + $psh = $sh; # copy it + $psh =~ s/\\b$//; # Take off trailing \b if any + $psh =~ s/\\(.)/$1/g; # De-escape + $psh; # return the printable version +} ## end sub shellBang + +=head2 C<ornaments> + +If the terminal has its own ornaments, fetch them. Otherwise accept whatever +was passed as the argument. (This means you can't override the terminal's +ornaments.) + +=cut + +sub ornaments { + if ( defined $term ) { + + # We don't want to show warning backtraces, but we do want die() ones. + local ( $warnLevel, $dieLevel ) = ( 0, 1 ); + + # No ornaments if the terminal doesn't support them. + return '' unless $term->Features->{ornaments}; + eval { $term->ornaments(@_) } || ''; + } + + # Use what was passed in if we can't determine it ourselves. + else { + $ornaments = shift; + } +} ## end sub ornaments + +=head2 C<recallCommand> + +Sets the recall command, and builds a printable version which will appear in +the help text. + +=cut + +sub recallCommand { + + # If there is input, metaquote it. Add '\b' if it ends with a word + # character. + if (@_) { + $rc = quotemeta shift; + $rc .= "\\b" if $rc =~ /\w$/; + } + + # Build it into a printable version. + $prc = $rc; # Copy it + $prc =~ s/\\b$//; # Remove trailing \b + $prc =~ s/\\(.)/$1/g; # Remove escapes + $prc; # Return the printable version +} ## end sub recallCommand + +=head2 C<LineInfo> - where the line number information goes + +Called with no arguments, returns the file or pipe that line info should go to. + +Called with an argument (a file or a pipe), it opens that onto the +C<LINEINFO> filehandle, unbuffers the filehandle, and then returns the +file or pipe again to the caller. + +=cut + +sub LineInfo { + return $lineinfo unless @_; + $lineinfo = shift; + + # If this is a valid "thing to be opened for output", tack a + # '>' onto the front. + my $stream = ( $lineinfo =~ /^(\+?\>|\|)/ ) ? $lineinfo : ">$lineinfo"; + + # If this is a pipe, the stream points to a slave editor. + $slave_editor = ( $stream =~ /^\|/ ); + + # Open it up and unbuffer it. + open( LINEINFO, "$stream" ) || &warn("Cannot open `$stream' for write"); + $LINEINFO = \*LINEINFO; + my $save = select($LINEINFO); + $| = 1; + select($save); + + # Hand the file or pipe back again. + $lineinfo; +} ## end sub LineInfo + +=head1 COMMAND SUPPORT ROUTINES + +These subroutines provide functionality for various commands. + +=head2 C<list_modules> + +For the C<M> command: list modules loaded and their versions. +Essentially just runs through the keys in %INC, picks each package's +C<$VERSION> variable, gets the file name, and formats the information +for output. + +=cut + +sub list_modules { # versions + my %version; + my $file; + + # keys are the "as-loaded" name, values are the fully-qualified path + # to the file itself. + for ( keys %INC ) { + $file = $_; # get the module name + s,\.p[lm]$,,i; # remove '.pl' or '.pm' + s,/,::,g; # change '/' to '::' + s/^perl5db$/DB/; # Special case: debugger + # moves to package DB + s/^Term::ReadLine::readline$/readline/; # simplify readline + + # If the package has a $VERSION package global (as all good packages + # should!) decode it and save as partial message. + if ( defined ${ $_ . '::VERSION' } ) { + $version{$file} = "${ $_ . '::VERSION' } from "; + } + + # Finish up the message with the file the package came from. + $version{$file} .= $INC{$file}; + } ## end for (keys %INC) + + # Hey, dumpit() formats a hash nicely, so why not use it? + dumpit( $OUT, \%version ); +} ## end sub list_modules + +=head2 C<sethelp()> + +Sets up the monster string used to format and print the help. + +=head3 HELP MESSAGE FORMAT + +The help message is a peculiar format unto itself; it mixes C<pod> I<ornaments> +(C<< B<> >> C<< I<> >>) with tabs to come up with a format that's fairly +easy to parse and portable, but which still allows the help to be a little +nicer than just plain text. + +Essentially, you define the command name (usually marked up with C<< B<> >> +and C<< I<> >>), followed by a tab, and then the descriptive text, ending in a +newline. The descriptive text can also be marked up in the same way. If you +need to continue the descriptive text to another line, start that line with +just tabs and then enter the marked-up text. + +If you are modifying the help text, I<be careful>. The help-string parser is +not very sophisticated, and if you don't follow these rules it will mangle the +help beyond hope until you fix the string. + +=cut + +sub sethelp { + + # XXX: make sure there are tabs between the command and explanation, + # or print_help will screw up your formatting if you have + # eeevil ornaments enabled. This is an insane mess. + + $help = " +Help is currently only available for the new 5.8 command set. +No help is available for the old command set. +We assume you know what you're doing if you switch to it. + +B<T> Stack trace. +B<s> [I<expr>] Single step [in I<expr>]. +B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. +<B<CR>> Repeat last B<n> or B<s> command. +B<r> Return from current subroutine. +B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint + at the specified position. +B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. +B<l> I<min>B<->I<max> List lines I<min> through I<max>. +B<l> I<line> List single I<line>. +B<l> I<subname> List first window of lines from subroutine. +B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. +B<l> List next window of lines. +B<-> List previous window of lines. +B<v> [I<line>] View window around I<line>. +B<.> Return to the executed line. +B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. + I<filename> may be either the full name of the file, or a regular + expression matching the full file name: + B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. + Evals (with saved bodies) are considered to be filenames: + B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval + (in the order of execution). +B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. +B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. +B<L> [I<a|b|w>] List actions and or breakpoints and or watch-expressions. +B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. +B<t> Toggle trace mode. +B<t> I<expr> Trace through execution of I<expr>. +B<b> Sets breakpoint on current line) +B<b> [I<line>] [I<condition>] + Set breakpoint; I<line> defaults to the current execution line; + I<condition> breaks if it evaluates to true, defaults to '1'. +B<b> I<subname> [I<condition>] + Set breakpoint at first line of subroutine. +B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. +B<b> B<load> I<filename> Set breakpoint on 'require'ing the given file. +B<b> B<postpone> I<subname> [I<condition>] + Set breakpoint at first line of subroutine after + it is compiled. +B<b> B<compile> I<subname> + Stop after the subroutine is compiled. +B<B> [I<line>] Delete the breakpoint for I<line>. +B<B> I<*> Delete all breakpoints. +B<a> [I<line>] I<command> + Set an action to be done before the I<line> is executed; + I<line> defaults to the current execution line. + Sequence is: check for breakpoint/watchpoint, print line + if necessary, do action, prompt user if necessary, + execute line. +B<a> Does nothing +B<A> [I<line>] Delete the action for I<line>. +B<A> I<*> Delete all actions. +B<w> I<expr> Add a global watch-expression. +B<w> Does nothing +B<W> I<expr> Delete a global watch-expression. +B<W> I<*> Delete all watch-expressions. +B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). + Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. +B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". +B<x> I<expr> Evals expression in list context, dumps the result. +B<m> I<expr> Evals expression in list context, prints methods callable + on the first element of the result. +B<m> I<class> Prints methods callable via the given class. +B<M> Show versions of loaded modules. +B<i> I<class> Prints nested parents of given class. +B<e> Display current thread id. +B<E> Display all thread ids the current one will be identified: <n>. +B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. + +B<<> ? List Perl commands to run before each prompt. +B<<> I<expr> Define Perl command to run before each prompt. +B<<<> I<expr> Add to the list of Perl commands to run before each prompt. +B<< *> Delete the list of perl commands to run before each prompt. +B<>> ? List Perl commands to run after each prompt. +B<>> I<expr> Define Perl command to run after each prompt. +B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. +B<>>B< *> Delete the list of Perl commands to run after each prompt. +B<{> I<db_command> Define debugger command to run before each prompt. +B<{> ? List debugger commands to run before each prompt. +B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. +B<{ *> Delete the list of debugger commands to run before each prompt. +B<$prc> I<number> Redo a previous command (default previous command). +B<$prc> I<-number> Redo number'th-to-last command. +B<$prc> I<pattern> Redo last command that started with I<pattern>. + See 'B<O> I<recallCommand>' too. +B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" + . ( + $rc eq $sh + ? "" + : " +B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." + ) . " + See 'B<O> I<shellBang>' too. +B<source> I<file> Execute I<file> containing debugger commands (may nest). +B<save> I<file> Save current debugger session (actual history) to I<file>. +B<rerun> Rerun session to current position. +B<rerun> I<n> Rerun session to numbered command. +B<rerun> I<-n> Rerun session to number'th-to-last command. +B<H> I<-number> Display last number commands (default all). +B<H> I<*> Delete complete history. +B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. +B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. +B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well. +B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. +I<command> Execute as a perl statement in current package. +B<R> Pure-man-restart of debugger, some of debugger state + and command-line options may be lost. + Currently the following settings are preserved: + history, breakpoints and actions, debugger B<O>ptions + and the following command-line options: I<-w>, I<-I>, I<-e>. + +B<o> [I<opt>] ... Set boolean option to true +B<o> [I<opt>B<?>] Query options +B<o> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... + Set options. Use quotes if spaces in value. + I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; + I<pager> program for output of \"|cmd\"; + I<tkRunning> run Tk while prompting (with ReadLine); + I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; + I<inhibit_exit> Allows stepping off the end of the script. + I<ImmediateStop> Debugger should stop as early as possible. + I<RemotePort> Remote hostname:port for remote debugging + The following options affect what happens with B<V>, B<X>, and B<x> commands: + I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); + I<compactDump>, I<veryCompact> change style of array and hash dump; + I<globPrint> whether to print contents of globs; + I<DumpDBFiles> dump arrays holding debugged files; + I<DumpPackages> dump symbol tables of packages; + I<DumpReused> dump contents of \"reused\" addresses; + I<quote>, I<HighBit>, I<undefPrint> change style of string dump; + I<bareStringify> Do not print the overload-stringified value; + Other options include: + I<PrintRet> affects printing of return value after B<r> command, + I<frame> affects printing messages on subroutine entry/exit. + I<AutoTrace> affects printing messages on possible breaking points. + I<maxTraceLen> gives max length of evals/args listed in stack trace. + I<ornaments> affects screen appearance of the command line. + I<CreateTTY> bits control attempts to create a new TTY on events: + 1: on fork() 2: debugger is started inside debugger + 4: on startup + During startup options are initialized from \$ENV{PERLDB_OPTS}. + You can put additional initialization options I<TTY>, I<noTTY>, + I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use + `B<R>' after you set them). + +B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. +B<h> Summary of debugger commands. +B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. +B<h h> Long help for debugger commands +B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the + named Perl I<manpage>, or on B<$doccmd> itself if omitted. + Set B<\$DB::doccmd> to change viewer. + +Type `|h h' for a paged display if this was too hard to read. + +"; # Fix balance of vi % matching: }}}} + + # note: tabs in the following section are not-so-helpful + $summary = <<"END_SUM"; +I<List/search source lines:> I<Control script execution:> + B<l> [I<ln>|I<sub>] List source code B<T> Stack trace + B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] + B<v> [I<line>] View around line B<n> [I<expr>] Next, steps over subs + B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> + B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine + B<M> Show module versions B<c> [I<ln>|I<sub>] Continue until position +I<Debugger controls:> B<L> List break/watch/actions + B<o> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr] + B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint + B<$prc> [I<N>|I<pat>] Redo a previous command B<B> I<ln|*> Delete a/all breakpoints + B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line + B<=> [I<a> I<val>] Define/list an alias B<A> I<ln|*> Delete a/all actions + B<h> [I<db_cmd>] Get help on command B<w> I<expr> Add a watch expression + B<h h> Complete help page B<W> I<expr|*> Delete a/all watch exprs + B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess + B<q> or B<^D> Quit B<R> Attempt a restart +I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> + B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. + B<p> I<expr> Print expression (uses script's current package). + B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern + B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. + B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". B<i> I<class> inheritance tree. + B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. + B<e> Display thread id B<E> Display all thread ids. +For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. +END_SUM + + # ')}}; # Fix balance of vi % matching + + # and this is really numb... + $pre580_help = " +B<T> Stack trace. +B<s> [I<expr>] Single step [in I<expr>]. +B<n> [I<expr>] Next, steps over subroutine calls [in I<expr>]. +B<CR>> Repeat last B<n> or B<s> command. +B<r> Return from current subroutine. +B<c> [I<line>|I<sub>] Continue; optionally inserts a one-time-only breakpoint + at the specified position. +B<l> I<min>B<+>I<incr> List I<incr>+1 lines starting at I<min>. +B<l> I<min>B<->I<max> List lines I<min> through I<max>. +B<l> I<line> List single I<line>. +B<l> I<subname> List first window of lines from subroutine. +B<l> I<\$var> List first window of lines from subroutine referenced by I<\$var>. +B<l> List next window of lines. +B<-> List previous window of lines. +B<w> [I<line>] List window around I<line>. +B<.> Return to the executed line. +B<f> I<filename> Switch to viewing I<filename>. File must be already loaded. + I<filename> may be either the full name of the file, or a regular + expression matching the full file name: + B<f> I</home/me/foo.pl> and B<f> I<oo\\.> may access the same file. + Evals (with saved bodies) are considered to be filenames: + B<f> I<(eval 7)> and B<f> I<eval 7\\b> access the body of the 7th eval + (in the order of execution). +B</>I<pattern>B</> Search forwards for I<pattern>; final B</> is optional. +B<?>I<pattern>B<?> Search backwards for I<pattern>; final B<?> is optional. +B<L> List all breakpoints and actions. +B<S> [[B<!>]I<pattern>] List subroutine names [not] matching I<pattern>. +B<t> Toggle trace mode. +B<t> I<expr> Trace through execution of I<expr>. +B<b> [I<line>] [I<condition>] + Set breakpoint; I<line> defaults to the current execution line; + I<condition> breaks if it evaluates to true, defaults to '1'. +B<b> I<subname> [I<condition>] + Set breakpoint at first line of subroutine. +B<b> I<\$var> Set breakpoint at first line of subroutine referenced by I<\$var>. +B<b> B<load> I<filename> Set breakpoint on `require'ing the given file. +B<b> B<postpone> I<subname> [I<condition>] + Set breakpoint at first line of subroutine after + it is compiled. +B<b> B<compile> I<subname> + Stop after the subroutine is compiled. +B<d> [I<line>] Delete the breakpoint for I<line>. +B<D> Delete all breakpoints. +B<a> [I<line>] I<command> + Set an action to be done before the I<line> is executed; + I<line> defaults to the current execution line. + Sequence is: check for breakpoint/watchpoint, print line + if necessary, do action, prompt user if necessary, + execute line. +B<a> [I<line>] Delete the action for I<line>. +B<A> Delete all actions. +B<W> I<expr> Add a global watch-expression. +B<W> Delete all watch-expressions. +B<V> [I<pkg> [I<vars>]] List some (default all) variables in package (default current). + Use B<~>I<pattern> and B<!>I<pattern> for positive and negative regexps. +B<X> [I<vars>] Same as \"B<V> I<currentpackage> [I<vars>]\". +B<x> I<expr> Evals expression in list context, dumps the result. +B<m> I<expr> Evals expression in list context, prints methods callable + on the first element of the result. +B<m> I<class> Prints methods callable via the given class. + +B<<> ? List Perl commands to run before each prompt. +B<<> I<expr> Define Perl command to run before each prompt. +B<<<> I<expr> Add to the list of Perl commands to run before each prompt. +B<>> ? List Perl commands to run after each prompt. +B<>> I<expr> Define Perl command to run after each prompt. +B<>>B<>> I<expr> Add to the list of Perl commands to run after each prompt. +B<{> I<db_command> Define debugger command to run before each prompt. +B<{> ? List debugger commands to run before each prompt. +B<{{> I<db_command> Add to the list of debugger commands to run before each prompt. +B<$prc> I<number> Redo a previous command (default previous command). +B<$prc> I<-number> Redo number'th-to-last command. +B<$prc> I<pattern> Redo last command that started with I<pattern>. + See 'B<O> I<recallCommand>' too. +B<$psh$psh> I<cmd> Run cmd in a subprocess (reads from DB::IN, writes to DB::OUT)" + . ( + $rc eq $sh + ? "" + : " +B<$psh> [I<cmd>] Run I<cmd> in subshell (forces \"\$SHELL -c 'cmd'\")." + ) . " + See 'B<O> I<shellBang>' too. +B<source> I<file> Execute I<file> containing debugger commands (may nest). +B<H> I<-number> Display last number commands (default all). +B<p> I<expr> Same as \"I<print {DB::OUT} expr>\" in current package. +B<|>I<dbcmd> Run debugger command, piping DB::OUT to current pager. +B<||>I<dbcmd> Same as B<|>I<dbcmd> but DB::OUT is temporarilly select()ed as well. +B<\=> [I<alias> I<value>] Define a command alias, or list current aliases. +I<command> Execute as a perl statement in current package. +B<v> Show versions of loaded modules. +B<R> Pure-man-restart of debugger, some of debugger state + and command-line options may be lost. + Currently the following settings are preserved: + history, breakpoints and actions, debugger B<O>ptions + and the following command-line options: I<-w>, I<-I>, I<-e>. + +B<O> [I<opt>] ... Set boolean option to true +B<O> [I<opt>B<?>] Query options +B<O> [I<opt>B<=>I<val>] [I<opt>=B<\">I<val>B<\">] ... + Set options. Use quotes if spaces in value. + I<recallCommand>, I<ShellBang> chars used to recall command or spawn shell; + I<pager> program for output of \"|cmd\"; + I<tkRunning> run Tk while prompting (with ReadLine); + I<signalLevel> I<warnLevel> I<dieLevel> level of verbosity; + I<inhibit_exit> Allows stepping off the end of the script. + I<ImmediateStop> Debugger should stop as early as possible. + I<RemotePort> Remote hostname:port for remote debugging + The following options affect what happens with B<V>, B<X>, and B<x> commands: + I<arrayDepth>, I<hashDepth> print only first N elements ('' for all); + I<compactDump>, I<veryCompact> change style of array and hash dump; + I<globPrint> whether to print contents of globs; + I<DumpDBFiles> dump arrays holding debugged files; + I<DumpPackages> dump symbol tables of packages; + I<DumpReused> dump contents of \"reused\" addresses; + I<quote>, I<HighBit>, I<undefPrint> change style of string dump; + I<bareStringify> Do not print the overload-stringified value; + Other options include: + I<PrintRet> affects printing of return value after B<r> command, + I<frame> affects printing messages on subroutine entry/exit. + I<AutoTrace> affects printing messages on possible breaking points. + I<maxTraceLen> gives max length of evals/args listed in stack trace. + I<ornaments> affects screen appearance of the command line. + I<CreateTTY> bits control attempts to create a new TTY on events: + 1: on fork() 2: debugger is started inside debugger + 4: on startup + During startup options are initialized from \$ENV{PERLDB_OPTS}. + You can put additional initialization options I<TTY>, I<noTTY>, + I<ReadLine>, I<NonStop>, and I<RemotePort> there (or use + `B<R>' after you set them). + +B<q> or B<^D> Quit. Set B<\$DB::finished = 0> to debug global destruction. +B<h> [I<db_command>] Get help [on a specific debugger command], enter B<|h> to page. +B<h h> Summary of debugger commands. +B<$doccmd> I<manpage> Runs the external doc viewer B<$doccmd> command on the + named Perl I<manpage>, or on B<$doccmd> itself if omitted. + Set B<\$DB::doccmd> to change viewer. + +Type `|h' for a paged display if this was too hard to read. + +"; # Fix balance of vi % matching: }}}} + + # note: tabs in the following section are not-so-helpful + $pre580_summary = <<"END_SUM"; +I<List/search source lines:> I<Control script execution:> + B<l> [I<ln>|I<sub>] List source code B<T> Stack trace + B<-> or B<.> List previous/current line B<s> [I<expr>] Single step [in expr] + B<w> [I<line>] List around line B<n> [I<expr>] Next, steps over subs + B<f> I<filename> View source in file <B<CR>/B<Enter>> Repeat last B<n> or B<s> + B</>I<pattern>B</> B<?>I<patt>B<?> Search forw/backw B<r> Return from subroutine + B<v> Show versions of modules B<c> [I<ln>|I<sub>] Continue until position +I<Debugger controls:> B<L> List break/watch/actions + B<O> [...] Set debugger options B<t> [I<expr>] Toggle trace [trace expr] + B<<>[B<<>]|B<{>[B<{>]|B<>>[B<>>] [I<cmd>] Do pre/post-prompt B<b> [I<ln>|I<event>|I<sub>] [I<cnd>] Set breakpoint + B<$prc> [I<N>|I<pat>] Redo a previous command B<d> [I<ln>] or B<D> Delete a/all breakpoints + B<H> [I<-num>] Display last num commands B<a> [I<ln>] I<cmd> Do cmd before line + B<=> [I<a> I<val>] Define/list an alias B<W> I<expr> Add a watch expression + B<h> [I<db_cmd>] Get help on command B<A> or B<W> Delete all actions/watch + B<|>[B<|>]I<db_cmd> Send output to pager B<$psh>\[B<$psh>\] I<syscmd> Run cmd in a subprocess + B<q> or B<^D> Quit B<R> Attempt a restart +I<Data Examination:> B<expr> Execute perl code, also see: B<s>,B<n>,B<t> I<expr> + B<x>|B<m> I<expr> Evals expr in list context, dumps the result or lists methods. + B<p> I<expr> Print expression (uses script's current package). + B<S> [[B<!>]I<pat>] List subroutine names [not] matching pattern + B<V> [I<Pk> [I<Vars>]] List Variables in Package. Vars can be ~pattern or !pattern. + B<X> [I<Vars>] Same as \"B<V> I<current_package> [I<Vars>]\". + B<y> [I<n> [I<Vars>]] List lexicals in higher scope <n>. Vars same as B<V>. +For more help, type B<h> I<cmd_letter>, or run B<$doccmd perldebug> for all docs. +END_SUM + + # ')}}; # Fix balance of vi % matching + +} ## end sub sethelp + +=head2 C<print_help()> + +Most of what C<print_help> does is just text formatting. It finds the +C<B> and C<I> ornaments, cleans them off, and substitutes the proper +terminal control characters to simulate them (courtesy of +C<Term::ReadLine::TermCap>). + +=cut + +sub print_help { + local $_ = shift; + + # Restore proper alignment destroyed by eeevil I<> and B<> + # ornaments: A pox on both their houses! + # + # A help command will have everything up to and including + # the first tab sequence padded into a field 16 (or if indented 20) + # wide. If it's wider than that, an extra space will be added. + s{ + ^ # only matters at start of line + ( \040{4} | \t )* # some subcommands are indented + ( < ? # so <CR> works + [BI] < [^\t\n] + ) # find an eeevil ornament + ( \t+ ) # original separation, discarded + ( .* ) # this will now start (no earlier) than + # column 16 + } { + my($leadwhite, $command, $midwhite, $text) = ($1, $2, $3, $4); + my $clean = $command; + $clean =~ s/[BI]<([^>]*)>/$1/g; + + # replace with this whole string: + ($leadwhite ? " " x 4 : "") + . $command + . ((" " x (16 + ($leadwhite ? 4 : 0) - length($clean))) || " ") + . $text; + + }mgex; + + s{ # handle bold ornaments + B < ( [^>] + | > ) > + } { + $Term::ReadLine::TermCap::rl_term_set[2] + . $1 + . $Term::ReadLine::TermCap::rl_term_set[3] + }gex; + + s{ # handle italic ornaments + I < ( [^>] + | > ) > + } { + $Term::ReadLine::TermCap::rl_term_set[0] + . $1 + . $Term::ReadLine::TermCap::rl_term_set[1] + }gex; + + local $\ = ''; + print $OUT $_; +} ## end sub print_help + +=head2 C<fix_less> + +This routine does a lot of gyrations to be sure that the pager is C<less>. +It checks for C<less> masquerading as C<more> and records the result in +C<$ENV{LESS}> so we don't have to go through doing the stats again. + +=cut + +sub fix_less { + + # We already know if this is set. + return if defined $ENV{LESS} && $ENV{LESS} =~ /r/; + + # Pager is less for sure. + my $is_less = $pager =~ /\bless\b/; + if ( $pager =~ /\bmore\b/ ) { + + # Nope, set to more. See what's out there. + my @st_more = stat('/usr/bin/more'); + my @st_less = stat('/usr/bin/less'); + + # is it really less, pretending to be more? + $is_less = @st_more + && @st_less + && $st_more[0] == $st_less[0] + && $st_more[1] == $st_less[1]; + } ## end if ($pager =~ /\bmore\b/) + + # changes environment! + # 'r' added so we don't do (slow) stats again. + $ENV{LESS} .= 'r' if $is_less; +} ## end sub fix_less + +=head1 DIE AND WARN MANAGEMENT + +=head2 C<diesignal> + +C<diesignal> is a just-drop-dead C<die> handler. It's most useful when trying +to debug a debugger problem. + +It does its best to report the error that occurred, and then forces the +program, debugger, and everything to die. + +=cut + +sub diesignal { + + # No entry/exit messages. + local $frame = 0; + + # No return value prints. + local $doret = -2; + + # set the abort signal handling to the default (just terminate). + $SIG{'ABRT'} = 'DEFAULT'; + + # If we enter the signal handler recursively, kill myself with an + # abort signal (so we just terminate). + kill 'ABRT', $$ if $panic++; + + # If we can show detailed info, do so. + if ( defined &Carp::longmess ) { + + # Don't recursively enter the warn handler, since we're carping. + local $SIG{__WARN__} = ''; + + # Skip two levels before reporting traceback: we're skipping + # mydie and confess. + local $Carp::CarpLevel = 2; # mydie + confess + + # Tell us all about it. + &warn( Carp::longmess("Signal @_") ); + } + + # No Carp. Tell us about the signal as best we can. + else { + local $\ = ''; + print $DB::OUT "Got signal @_\n"; + } + + # Drop dead. + kill 'ABRT', $$; +} ## end sub diesignal + +=head2 C<dbwarn> + +The debugger's own default C<$SIG{__WARN__}> handler. We load C<Carp> to +be able to get a stack trace, and output the warning message vi C<DB::dbwarn()>. + +=cut + +sub dbwarn { + + # No entry/exit trace. + local $frame = 0; + + # No return value printing. + local $doret = -2; + + # Turn off warn and die handling to prevent recursive entries to this + # routine. + local $SIG{__WARN__} = ''; + local $SIG{__DIE__} = ''; + + # Load Carp if we can. If $^S is false (current thing being compiled isn't + # done yet), we may not be able to do a require. + eval { require Carp } + if defined $^S; # If error/warning during compilation, + # require may be broken. + + # Use the core warn() unless Carp loaded OK. + CORE::warn( @_, + "\nCannot print stack trace, load with -MCarp option to see stack" ), + return + unless defined &Carp::longmess; + + # Save the current values of $single and $trace, and then turn them off. + my ( $mysingle, $mytrace ) = ( $single, $trace ); + $single = 0; + $trace = 0; + + # We can call Carp::longmess without its being "debugged" (which we + # don't want - we just want to use it!). Capture this for later. + my $mess = Carp::longmess(@_); + + # Restore $single and $trace to their original values. + ( $single, $trace ) = ( $mysingle, $mytrace ); + + # Use the debugger's own special way of printing warnings to print + # the stack trace message. + &warn($mess); +} ## end sub dbwarn + +=head2 C<dbdie> + +The debugger's own C<$SIG{__DIE__}> handler. Handles providing a stack trace +by loading C<Carp> and calling C<Carp::longmess()> to get it. We turn off +single stepping and tracing during the call to C<Carp::longmess> to avoid +debugging it - we just want to use it. + +If C<dieLevel> is zero, we let the program being debugged handle the +exceptions. If it's 1, you get backtraces for any exception. If it's 2, +the debugger takes over all exception handling, printing a backtrace and +displaying the exception via its C<dbwarn()> routine. + +=cut + +sub dbdie { + local $frame = 0; + local $doret = -2; + local $SIG{__DIE__} = ''; + local $SIG{__WARN__} = ''; + my $i = 0; + my $ineval = 0; + my $sub; + if ( $dieLevel > 2 ) { + local $SIG{__WARN__} = \&dbwarn; + &warn(@_); # Yell no matter what + return; + } + if ( $dieLevel < 2 ) { + die @_ if $^S; # in eval propagate + } + + # The code used to check $^S to see if compiliation of the current thing + # hadn't finished. We don't do it anymore, figuring eval is pretty stable. + eval { require Carp }; + + die( @_, + "\nCannot print stack trace, load with -MCarp option to see stack" ) + unless defined &Carp::longmess; + + # We do not want to debug this chunk (automatic disabling works + # inside DB::DB, but not in Carp). Save $single and $trace, turn them off, + # get the stack trace from Carp::longmess (if possible), restore $signal + # and $trace, and then die with the stack trace. + my ( $mysingle, $mytrace ) = ( $single, $trace ); + $single = 0; + $trace = 0; + my $mess = "@_"; + { + + package Carp; # Do not include us in the list + eval { $mess = Carp::longmess(@_); }; + } + ( $single, $trace ) = ( $mysingle, $mytrace ); + die $mess; +} ## end sub dbdie + +=head2 C<warnlevel()> + +Set the C<$DB::warnLevel> variable that stores the value of the +C<warnLevel> option. Calling C<warnLevel()> with a positive value +results in the debugger taking over all warning handlers. Setting +C<warnLevel> to zero leaves any warning handlers set up by the program +being debugged in place. + +=cut + +sub warnLevel { + if (@_) { + $prevwarn = $SIG{__WARN__} unless $warnLevel; + $warnLevel = shift; + if ($warnLevel) { + $SIG{__WARN__} = \&DB::dbwarn; + } + elsif ($prevwarn) { + $SIG{__WARN__} = $prevwarn; + } else { + undef $SIG{__WARN__}; + } + } ## end if (@_) + $warnLevel; +} ## end sub warnLevel + +=head2 C<dielevel> + +Similar to C<warnLevel>. Non-zero values for C<dieLevel> result in the +C<DB::dbdie()> function overriding any other C<die()> handler. Setting it to +zero lets you use your own C<die()> handler. + +=cut + +sub dieLevel { + local $\ = ''; + if (@_) { + $prevdie = $SIG{__DIE__} unless $dieLevel; + $dieLevel = shift; + if ($dieLevel) { + + # Always set it to dbdie() for non-zero values. + $SIG{__DIE__} = \&DB::dbdie; # if $dieLevel < 2; + + # No longer exists, so don't try to use it. + #$SIG{__DIE__} = \&DB::diehard if $dieLevel >= 2; + + # If we've finished initialization, mention that stack dumps + # are enabled, If dieLevel is 1, we won't stack dump if we die + # in an eval(). + print $OUT "Stack dump during die enabled", + ( $dieLevel == 1 ? " outside of evals" : "" ), ".\n" + if $I_m_init; + + # XXX This is probably obsolete, given that diehard() is gone. + print $OUT "Dump printed too.\n" if $dieLevel > 2; + } ## end if ($dieLevel) + + # Put the old one back if there was one. + elsif ($prevdie) { + $SIG{__DIE__} = $prevdie; + print $OUT "Default die handler restored.\n"; + } else { + undef $SIG{__DIE__}; + print $OUT "Die handler removed.\n"; + } + } ## end if (@_) + $dieLevel; +} ## end sub dieLevel + +=head2 C<signalLevel> + +Number three in a series: set C<signalLevel> to zero to keep your own +signal handler for C<SIGSEGV> and/or C<SIGBUS>. Otherwise, the debugger +takes over and handles them with C<DB::diesignal()>. + +=cut + +sub signalLevel { + if (@_) { + $prevsegv = $SIG{SEGV} unless $signalLevel; + $prevbus = $SIG{BUS} unless $signalLevel; + $signalLevel = shift; + if ($signalLevel) { + $SIG{SEGV} = \&DB::diesignal; + $SIG{BUS} = \&DB::diesignal; + } + else { + $SIG{SEGV} = $prevsegv; + $SIG{BUS} = $prevbus; + } + } ## end if (@_) + $signalLevel; +} ## end sub signalLevel + +=head1 SUBROUTINE DECODING SUPPORT + +These subroutines are used during the C<x> and C<X> commands to try to +produce as much information as possible about a code reference. They use +L<Devel::Peek> to try to find the glob in which this code reference lives +(if it does) - this allows us to actually code references which correspond +to named subroutines (including those aliased via glob assignment). + +=head2 C<CvGV_name()> + +Wrapper for C<CvGV_name_or_bust>; tries to get the name of a reference +via that routine. If this fails, return the reference again (when the +reference is stringified, it'll come out as C<SOMETHING(0x...)>). + +=cut + +sub CvGV_name { + my $in = shift; + my $name = CvGV_name_or_bust($in); + defined $name ? $name : $in; +} + +=head2 C<CvGV_name_or_bust> I<coderef> + +Calls L<Devel::Peek> to try to find the glob the ref lives in; returns +C<undef> if L<Devel::Peek> can't be loaded, or if C<Devel::Peek::CvGV> can't +find a glob for this ref. + +Returns C<< I<package>::I<glob name> >> if the code ref is found in a glob. + +=cut + +sub CvGV_name_or_bust { + my $in = shift; + return if $skipCvGV; # Backdoor to avoid problems if XS broken... + return unless ref $in; + $in = \&$in; # Hard reference... + eval { require Devel::Peek; 1 } or return; + my $gv = Devel::Peek::CvGV($in) or return; + *$gv{PACKAGE} . '::' . *$gv{NAME}; +} ## end sub CvGV_name_or_bust + +=head2 C<find_sub> + +A utility routine used in various places; finds the file where a subroutine +was defined, and returns that filename and a line-number range. + +Tries to use C<@sub> first; if it can't find it there, it tries building a +reference to the subroutine and uses C<CvGV_name_or_bust> to locate it, +loading it into C<@sub> as a side effect (XXX I think). If it can't find it +this way, it brute-force searches C<%sub>, checking for identical references. + +=cut + +sub find_sub { + my $subr = shift; + $sub{$subr} or do { + return unless defined &$subr; + my $name = CvGV_name_or_bust($subr); + my $data; + $data = $sub{$name} if defined $name; + return $data if defined $data; + + # Old stupid way... + $subr = \&$subr; # Hard reference + my $s; + for ( keys %sub ) { + $s = $_, last if $subr eq \&$_; + } + $sub{$s} if $s; + } ## end do +} ## end sub find_sub + +=head2 C<methods> + +A subroutine that uses the utility function C<methods_via> to find all the +methods in the class corresponding to the current reference and in +C<UNIVERSAL>. + +=cut + +sub methods { + + # Figure out the class - either this is the class or it's a reference + # to something blessed into that class. + my $class = shift; + $class = ref $class if ref $class; + + local %seen; + + # Show the methods that this class has. + methods_via( $class, '', 1 ); + + # Show the methods that UNIVERSAL has. + methods_via( 'UNIVERSAL', 'UNIVERSAL', 0 ); +} ## end sub methods + +=head2 C<methods_via($class, $prefix, $crawl_upward)> + +C<methods_via> does the work of crawling up the C<@ISA> tree and reporting +all the parent class methods. C<$class> is the name of the next class to +try; C<$prefix> is the message prefix, which gets built up as we go up the +C<@ISA> tree to show parentage; C<$crawl_upward> is 1 if we should try to go +higher in the C<@ISA> tree, 0 if we should stop. + +=cut + +sub methods_via { + + # If we've processed this class already, just quit. + my $class = shift; + return if $seen{$class}++; + + # This is a package that is contributing the methods we're about to print. + my $prefix = shift; + my $prepend = $prefix ? "via $prefix: " : ''; + my @to_print; + + # Extract from all the symbols in this class. + while (my ($name, $glob) = each %{"${class}::"}) { + # references directly in the symbol table are Proxy Constant + # Subroutines, and are by their very nature defined + # Otherwise, check if the thing is a typeglob, and if it is, it decays + # to a subroutine reference, which can be tested by defined. + # $glob might also be the value -1 (from sub foo;) + # or (say) '$$' (from sub foo ($$);) + # \$glob will be SCALAR in both cases. + if ((ref $glob || ($glob && ref \$glob eq 'GLOB' && defined &$glob)) + && !$seen{$name}++) { + push @to_print, "$prepend$name\n"; + } + } + + { + local $\ = ''; + local $, = ''; + print $DB::OUT $_ foreach sort @to_print; + } + + # If the $crawl_upward argument is false, just quit here. + return unless shift; + + # $crawl_upward true: keep going up the tree. + # Find all the classes this one is a subclass of. + for $name ( @{"${class}::ISA"} ) { + + # Set up the new prefix. + $prepend = $prefix ? $prefix . " -> $name" : $name; + + # Crawl up the tree and keep trying to crawl up. + methods_via( $name, $prepend, 1 ); + } +} ## end sub methods_via + +=head2 C<setman> - figure out which command to use to show documentation + +Just checks the contents of C<$^O> and sets the C<$doccmd> global accordingly. + +=cut + +sub setman { + $doccmd = $^O !~ /^(?:MSWin32|VMS|os2|dos|amigaos|riscos|MacOS|NetWare)\z/s + ? "man" # O Happy Day! + : "perldoc"; # Alas, poor unfortunates +} ## end sub setman + +=head2 C<runman> - run the appropriate command to show documentation + +Accepts a man page name; runs the appropriate command to display it (set up +during debugger initialization). Uses C<DB::system> to avoid mucking up the +program's STDIN and STDOUT. + +=cut + +sub runman { + my $page = shift; + unless ($page) { + &system("$doccmd $doccmd"); + return; + } + + # this way user can override, like with $doccmd="man -Mwhatever" + # or even just "man " to disable the path check. + unless ( $doccmd eq 'man' ) { + &system("$doccmd $page"); + return; + } + + $page = 'perl' if lc($page) eq 'help'; + + require Config; + my $man1dir = $Config::Config{'man1dir'}; + my $man3dir = $Config::Config{'man3dir'}; + for ( $man1dir, $man3dir ) { s#/[^/]*\z## if /\S/ } + my $manpath = ''; + $manpath .= "$man1dir:" if $man1dir =~ /\S/; + $manpath .= "$man3dir:" if $man3dir =~ /\S/ && $man1dir ne $man3dir; + chop $manpath if $manpath; + + # harmless if missing, I figure + my $oldpath = $ENV{MANPATH}; + $ENV{MANPATH} = $manpath if $manpath; + my $nopathopt = $^O =~ /dunno what goes here/; + if ( + CORE::system( + $doccmd, + + # I just *know* there are men without -M + ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), + split ' ', $page + ) + ) + { + unless ( $page =~ /^perl\w/ ) { +# do it this way because its easier to slurp in to keep up to date - clunky though. +my @pods = qw( + 5004delta + 5005delta + 561delta + 56delta + 570delta + 571delta + 572delta + 573delta + 58delta + 581delta + 582delta + 583delta + 584delta + 590delta + 591delta + 592delta + aix + amiga + apio + api + apollo + artistic + beos + book + boot + bot + bs2000 + call + ce + cheat + clib + cn + compile + cygwin + data + dbmfilter + debguts + debtut + debug + delta + dgux + diag + doc + dos + dsc + ebcdic + embed + epoc + faq1 + faq2 + faq3 + faq4 + faq5 + faq6 + faq7 + faq8 + faq9 + faq + filter + fork + form + freebsd + func + gpl + guts + hack + hist + hpux + hurd + intern + intro + iol + ipc + irix + jp + ko + lexwarn + locale + lol + machten + macos + macosx + mint + modinstall + modlib + mod + modstyle + mpeix + netware + newmod + number + obj + opentut + op + os2 + os390 + os400 + othrtut + packtut + plan9 + pod + podspec + port + qnx + ref + reftut + re + requick + reref + retut + run + sec + solaris + style + sub + syn + thrtut + tie + toc + todo + tooc + toot + trap + tru64 + tw + unicode + uniintro + util + uts + var + vmesa + vms + vos + win32 + xs + xstut +); + if (grep { $page eq $_ } @pods) { + $page =~ s/^/perl/; + CORE::system( $doccmd, + ( ( $manpath && !$nopathopt ) ? ( "-M", $manpath ) : () ), + $page ); + } ## end if (grep { $page eq $_... + } ## end unless ($page =~ /^perl\w/) + } ## end if (CORE::system($doccmd... + if ( defined $oldpath ) { + $ENV{MANPATH} = $manpath; + } + else { + delete $ENV{MANPATH}; + } +} ## end sub runman + +#use Carp; # This did break, left for debugging + +=head1 DEBUGGER INITIALIZATION - THE SECOND BEGIN BLOCK + +Because of the way the debugger interface to the Perl core is designed, any +debugger package globals that C<DB::sub()> requires have to be defined before +any subroutines can be called. These are defined in the second C<BEGIN> block. + +This block sets things up so that (basically) the world is sane +before the debugger starts executing. We set up various variables that the +debugger has to have set up before the Perl core starts running: + +=over 4 + +=item * + +The debugger's own filehandles (copies of STD and STDOUT for now). + +=item * + +Characters for shell escapes, the recall command, and the history command. + +=item * + +The maximum recursion depth. + +=item * + +The size of a C<w> command's window. + +=item * + +The before-this-line context to be printed in a C<v> (view a window around this line) command. + +=item * + +The fact that we're not in a sub at all right now. + +=item * + +The default SIGINT handler for the debugger. + +=item * + +The appropriate value of the flag in C<$^D> that says the debugger is running + +=item * + +The current debugger recursion level + +=item * + +The list of postponed items and the C<$single> stack (XXX define this) + +=item * + +That we want no return values and no subroutine entry/exit trace. + +=back + +=cut + +# The following BEGIN is very handy if debugger goes havoc, debugging debugger? + +BEGIN { # This does not compile, alas. (XXX eh?) + $IN = \*STDIN; # For bugs before DB::OUT has been opened + $OUT = \*STDERR; # For errors before DB::OUT has been opened + + # Define characters used by command parsing. + $sh = '!'; # Shell escape (does not work) + $rc = ','; # Recall command (does not work) + @hist = ('?'); # Show history (does not work) + @truehist = (); # Can be saved for replay (per session) + + # This defines the point at which you get the 'deep recursion' + # warning. It MUST be defined or the debugger will not load. + $deep = 100; + + # Number of lines around the current one that are shown in the + # 'w' command. + $window = 10; + + # How much before-the-current-line context the 'v' command should + # use in calculating the start of the window it will display. + $preview = 3; + + # We're not in any sub yet, but we need this to be a defined value. + $sub = ''; + + # Set up the debugger's interrupt handler. It simply sets a flag + # ($signal) that DB::DB() will check before each command is executed. + $SIG{INT} = \&DB::catch; + + # The following lines supposedly, if uncommented, allow the debugger to + # debug itself. Perhaps we can try that someday. + # This may be enabled to debug debugger: + #$warnLevel = 1 unless defined $warnLevel; + #$dieLevel = 1 unless defined $dieLevel; + #$signalLevel = 1 unless defined $signalLevel; + + # This is the flag that says "a debugger is running, please call + # DB::DB and DB::sub". We will turn it on forcibly before we try to + # execute anything in the user's context, because we always want to + # get control back. + $db_stop = 0; # Compiler warning ... + $db_stop = 1 << 30; # ... because this is only used in an eval() later. + + # This variable records how many levels we're nested in debugging. Used + # Used in the debugger prompt, and in determining whether it's all over or + # not. + $level = 0; # Level of recursive debugging + + # "Triggers bug (?) in perl if we postpone this until runtime." + # XXX No details on this yet, or whether we should fix the bug instead + # of work around it. Stay tuned. + @postponed = @stack = (0); + + # Used to track the current stack depth using the auto-stacked-variable + # trick. + $stack_depth = 0; # Localized repeatedly; simple way to track $#stack + + # Don't print return values on exiting a subroutine. + $doret = -2; + + # No extry/exit tracing. + $frame = 0; + +} ## end BEGIN + +BEGIN { $^W = $ini_warn; } # Switch warnings back + +=head1 READLINE SUPPORT - COMPLETION FUNCTION + +=head2 db_complete + +C<readline> support - adds command completion to basic C<readline>. + +Returns a list of possible completions to C<readline> when invoked. C<readline> +will print the longest common substring following the text already entered. + +If there is only a single possible completion, C<readline> will use it in full. + +This code uses C<map> and C<grep> heavily to create lists of possible +completion. Think LISP in this section. + +=cut + +sub db_complete { + + # Specific code for b c l V m f O, &blah, $blah, @blah, %blah + # $text is the text to be completed. + # $line is the incoming line typed by the user. + # $start is the start of the text to be completed in the incoming line. + my ( $text, $line, $start ) = @_; + + # Save the initial text. + # The search pattern is current package, ::, extract the next qualifier + # Prefix and pack are set to undef. + my ( $itext, $search, $prefix, $pack ) = + ( $text, "^\Q${'package'}::\E([^:]+)\$" ); + +=head3 C<b postpone|compile> + +=over 4 + +=item * + +Find all the subroutines that might match in this package + +=item * + +Add C<postpone>, C<load>, and C<compile> as possibles (we may be completing the keyword itself) + +=item * + +Include all the rest of the subs that are known + +=item * + +C<grep> out the ones that match the text we have so far + +=item * + +Return this as the list of possible completions + +=back + +=cut + + return sort grep /^\Q$text/, ( keys %sub ), + qw(postpone load compile), # subroutines + ( map { /$search/ ? ($1) : () } keys %sub ) + if ( substr $line, 0, $start ) =~ /^\|*[blc]\s+((postpone|compile)\s+)?$/; + +=head3 C<b load> + +Get all the possible files from C<@INC> as it currently stands and +select the ones that match the text so far. + +=cut + + return sort grep /^\Q$text/, values %INC # files + if ( substr $line, 0, $start ) =~ /^\|*b\s+load\s+$/; + +=head3 C<V> (list variable) and C<m> (list modules) + +There are two entry points for these commands: + +=head4 Unqualified package names + +Get the top-level packages and grab everything that matches the text +so far. For each match, recursively complete the partial packages to +get all possible matching packages. Return this sorted list. + +=cut + + return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } + grep /^\Q$text/, map { /^(.*)::$/ ? ($1) : () } keys %:: # top-packages + if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ and $text =~ /^\w*$/; + +=head4 Qualified package names + +Take a partially-qualified package and find all subpackages for it +by getting all the subpackages for the package so far, matching all +the subpackages against the text, and discarding all of them which +start with 'main::'. Return this list. + +=cut + + return sort map { ( $_, db_complete( $_ . "::", "V ", 2 ) ) } + grep !/^main::/, grep /^\Q$text/, + map { /^(.*)::$/ ? ( $prefix . "::$1" ) : () } keys %{ $prefix . '::' } + if ( substr $line, 0, $start ) =~ /^\|*[Vm]\s+$/ + and $text =~ /^(.*[^:])::?(\w*)$/ + and $prefix = $1; + +=head3 C<f> - switch files + +Here, we want to get a fully-qualified filename for the C<f> command. +Possibilities are: + +=over 4 + +=item 1. The original source file itself + +=item 2. A file from C<@INC> + +=item 3. An C<eval> (the debugger gets a C<(eval N)> fake file for each C<eval>). + +=back + +=cut + + if ( $line =~ /^\|*f\s+(.*)/ ) { # Loaded files + # We might possibly want to switch to an eval (which has a "filename" + # like '(eval 9)'), so we may need to clean up the completion text + # before proceeding. + $prefix = length($1) - length($text); + $text = $1; + +=pod + +Under the debugger, source files are represented as C<_E<lt>/fullpath/to/file> +(C<eval>s are C<_E<lt>(eval NNN)>) keys in C<%main::>. We pull all of these +out of C<%main::>, add the initial source file, and extract the ones that +match the completion text so far. + +=cut + + return sort + map { substr $_, 2 + $prefix } grep /^_<\Q$text/, ( keys %main:: ), + $0; + } ## end if ($line =~ /^\|*f\s+(.*)/) + +=head3 Subroutine name completion + +We look through all of the defined subs (the keys of C<%sub>) and +return both all the possible matches to the subroutine name plus +all the matches qualified to the current package. + +=cut + + if ( ( substr $text, 0, 1 ) eq '&' ) { # subroutines + $text = substr $text, 1; + $prefix = "&"; + return sort map "$prefix$_", grep /^\Q$text/, ( keys %sub ), + ( + map { /$search/ ? ($1) : () } + keys %sub + ); + } ## end if ((substr $text, 0, ... + +=head3 Scalar, array, and hash completion: partially qualified package + +Much like the above, except we have to do a little more cleanup: + +=cut + + if ( $text =~ /^[\$@%](.*)::(.*)/ ) { # symbols in a package + +=pod + +=over 4 + +=item * + +Determine the package that the symbol is in. Put it in C<::> (effectively C<main::>) if no package is specified. + +=cut + + $pack = ( $1 eq 'main' ? '' : $1 ) . '::'; + +=pod + +=item * + +Figure out the prefix vs. what needs completing. + +=cut + + $prefix = ( substr $text, 0, 1 ) . $1 . '::'; + $text = $2; + +=pod + +=item * + +Look through all the symbols in the package. C<grep> out all the possible hashes/arrays/scalars, and then C<grep> the possible matches out of those. C<map> the prefix onto all the possibilities. + +=cut + + my @out = map "$prefix$_", grep /^\Q$text/, grep /^_?[a-zA-Z]/, + keys %$pack; + +=pod + +=item * + +If there's only one hit, and it's a package qualifier, and it's not equal to the initial text, re-complete it using the symbol we actually found. + +=cut + + if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { + return db_complete( $out[0], $line, $start ); + } + + # Return the list of possibles. + return sort @out; + + } ## end if ($text =~ /^[\$@%](.*)::(.*)/) + +=pod + +=back + +=head3 Symbol completion: current package or package C<main>. + +=cut + + if ( $text =~ /^[\$@%]/ ) { # symbols (in $package + packages in main) + +=pod + +=over 4 + +=item * + +If it's C<main>, delete main to just get C<::> leading. + +=cut + + $pack = ( $package eq 'main' ? '' : $package ) . '::'; + +=pod + +=item * + +We set the prefix to the item's sigil, and trim off the sigil to get the text to be completed. + +=cut + + $prefix = substr $text, 0, 1; + $text = substr $text, 1; + +=pod + +=item * + +If the package is C<::> (C<main>), create an empty list; if it's something else, create a list of all the packages known. Append whichever list to a list of all the possible symbols in the current package. C<grep> out the matches to the text entered so far, then C<map> the prefix back onto the symbols. + +=cut + + my @out = map "$prefix$_", grep /^\Q$text/, + ( grep /^_?[a-zA-Z]/, keys %$pack ), + ( $pack eq '::' ? () : ( grep /::$/, keys %:: ) ); + +=item * + +If there's only one hit, it's a package qualifier, and it's not equal to the initial text, recomplete using this symbol. + +=back + +=cut + + if ( @out == 1 and $out[0] =~ /::$/ and $out[0] ne $itext ) { + return db_complete( $out[0], $line, $start ); + } + + # Return the list of possibles. + return sort @out; + } ## end if ($text =~ /^[\$@%]/) + +=head3 Options + +We use C<option_val()> to look up the current value of the option. If there's +only a single value, we complete the command in such a way that it is a +complete command for setting the option in question. If there are multiple +possible values, we generate a command consisting of the option plus a trailing +question mark, which, if executed, will list the current value of the option. + +=cut + + if ( ( substr $line, 0, $start ) =~ /^\|*[oO]\b.*\s$/ ) + { # Options after space + # We look for the text to be matched in the list of possible options, + # and fetch the current value. + my @out = grep /^\Q$text/, @options; + my $val = option_val( $out[0], undef ); + + # Set up a 'query option's value' command. + my $out = '? '; + if ( not defined $val or $val =~ /[\n\r]/ ) { + + # There's really nothing else we can do. + } + + # We have a value. Create a proper option-setting command. + elsif ( $val =~ /\s/ ) { + + # XXX This may be an extraneous variable. + my $found; + + # We'll want to quote the string (because of the embedded + # whtespace), but we want to make sure we don't end up with + # mismatched quote characters. We try several possibilities. + foreach $l ( split //, qq/\"\'\#\|/ ) { + + # If we didn't find this quote character in the value, + # quote it using this quote character. + $out = "$l$val$l ", last if ( index $val, $l ) == -1; + } + } ## end elsif ($val =~ /\s/) + + # Don't need any quotes. + else { + $out = "=$val "; + } + + # If there were multiple possible values, return '? ', which + # makes the command into a query command. If there was just one, + # have readline append that. + $rl_attribs->{completer_terminator_character} = + ( @out == 1 ? $out : '? ' ); + + # Return list of possibilities. + return sort @out; + } ## end if ((substr $line, 0, ... + +=head3 Filename completion + +For entering filenames. We simply call C<readline>'s C<filename_list()> +method with the completion text to get the possible completions. + +=cut + + return $term->filename_list($text); # filenames + +} ## end sub db_complete + +=head1 MISCELLANEOUS SUPPORT FUNCTIONS + +Functions that possibly ought to be somewhere else. + +=head2 end_report + +Say we're done. + +=cut + +sub end_report { + local $\ = ''; + print $OUT "Use `q' to quit or `R' to restart. `h q' for details.\n"; +} + +=head2 clean_ENV + +If we have $ini_pids, save it in the environment; else remove it from the +environment. Used by the C<R> (restart) command. + +=cut + +sub clean_ENV { + if ( defined($ini_pids) ) { + $ENV{PERLDB_PIDS} = $ini_pids; + } + else { + delete( $ENV{PERLDB_PIDS} ); + } +} ## end sub clean_ENV + +# PERLDBf_... flag names from perl.h +our ( %DollarCaretP_flags, %DollarCaretP_flags_r ); + +BEGIN { + %DollarCaretP_flags = ( + PERLDBf_SUB => 0x01, # Debug sub enter/exit + PERLDBf_LINE => 0x02, # Keep line # + PERLDBf_NOOPT => 0x04, # Switch off optimizations + PERLDBf_INTER => 0x08, # Preserve more data + PERLDBf_SUBLINE => 0x10, # Keep subr source lines + PERLDBf_SINGLE => 0x20, # Start with single-step on + PERLDBf_NONAME => 0x40, # For _SUB: no name of the subr + PERLDBf_GOTO => 0x80, # Report goto: call DB::goto + PERLDBf_NAMEEVAL => 0x100, # Informative names for evals + PERLDBf_NAMEANON => 0x200, # Informative names for anon subs + PERLDBf_SAVESRC => 0x400, # Save source lines into @{"_<$filename"} + PERLDB_ALL => 0x33f, # No _NONAME, _GOTO + ); + # PERLDBf_LINE also enables the actions of PERLDBf_SAVESRC, so the debugger + # doesn't need to set it. It's provided for the benefit of profilers and + # other code analysers. + + %DollarCaretP_flags_r = reverse %DollarCaretP_flags; +} + +sub parse_DollarCaretP_flags { + my $flags = shift; + $flags =~ s/^\s+//; + $flags =~ s/\s+$//; + my $acu = 0; + foreach my $f ( split /\s*\|\s*/, $flags ) { + my $value; + if ( $f =~ /^0x([[:xdigit:]]+)$/ ) { + $value = hex $1; + } + elsif ( $f =~ /^(\d+)$/ ) { + $value = int $1; + } + elsif ( $f =~ /^DEFAULT$/i ) { + $value = $DollarCaretP_flags{PERLDB_ALL}; + } + else { + $f =~ /^(?:PERLDBf_)?(.*)$/i; + $value = $DollarCaretP_flags{ 'PERLDBf_' . uc($1) }; + unless ( defined $value ) { + print $OUT ( + "Unrecognized \$^P flag '$f'!\n", + "Acceptable flags are: " + . join( ', ', sort keys %DollarCaretP_flags ), + ", and hexadecimal and decimal numbers.\n" + ); + return undef; + } + } + $acu |= $value; + } + $acu; +} + +sub expand_DollarCaretP_flags { + my $DollarCaretP = shift; + my @bits = ( + map { + my $n = ( 1 << $_ ); + ( $DollarCaretP & $n ) + ? ( $DollarCaretP_flags_r{$n} + || sprintf( '0x%x', $n ) ) + : () + } 0 .. 31 + ); + return @bits ? join( '|', @bits ) : 0; +} + +=over 4 + +=item rerun + +Rerun the current session to: + + rerun current position + + rerun 4 command number 4 + + rerun -4 current command minus 4 (go back 4 steps) + +Whether this always makes sense, in the current context is unknowable, and is +in part left as a useful exersize for the reader. This sub returns the +appropriate arguments to rerun the current session. + +=cut + +sub rerun { + my $i = shift; + my @args; + pop(@truehist); # strim + unless (defined $truehist[$i]) { + print "Unable to return to non-existent command: $i\n"; + } else { + $#truehist = ($i < 0 ? $#truehist + $i : $i > 0 ? $i : $#truehist); + my @temp = @truehist; # store + push(@DB::typeahead, @truehist); # saved + @truehist = @hist = (); # flush + @args = &restart(); # setup + &get_list("PERLDB_HIST"); # clean + &set_list("PERLDB_HIST", @temp); # reset + } + return @args; +} + +=item restart + +Restarting the debugger is a complex operation that occurs in several phases. +First, we try to reconstruct the command line that was used to invoke Perl +and the debugger. + +=cut + +sub restart { + # I may not be able to resurrect you, but here goes ... + print $OUT +"Warning: some settings and command-line options may be lost!\n"; + my ( @script, @flags, $cl ); + + # If warn was on before, turn it on again. + push @flags, '-w' if $ini_warn; + + # Rebuild the -I flags that were on the initial + # command line. + for (@ini_INC) { + push @flags, '-I', $_; + } + + # Turn on taint if it was on before. + push @flags, '-T' if ${^TAINT}; + + # Arrange for setting the old INC: + # Save the current @init_INC in the environment. + set_list( "PERLDB_INC", @ini_INC ); + + # If this was a perl one-liner, go to the "file" + # corresponding to the one-liner read all the lines + # out of it (except for the first one, which is going + # to be added back on again when 'perl -d' runs: that's + # the 'require perl5db.pl;' line), and add them back on + # to the command line to be executed. + if ( $0 eq '-e' ) { + for ( 1 .. $#{'::_<-e'} ) { # The first line is PERL5DB + chomp( $cl = ${'::_<-e'}[$_] ); + push @script, '-e', $cl; + } + } ## end if ($0 eq '-e') + + # Otherwise we just reuse the original name we had + # before. + else { + @script = $0; + } + +=pod + +After the command line has been reconstructed, the next step is to save +the debugger's status in environment variables. The C<DB::set_list> routine +is used to save aggregate variables (both hashes and arrays); scalars are +just popped into environment variables directly. + +=cut + + # If the terminal supported history, grab it and + # save that in the environment. + set_list( "PERLDB_HIST", + $term->Features->{getHistory} + ? $term->GetHistory + : @hist ); + + # Find all the files that were visited during this + # session (i.e., the debugger had magic hashes + # corresponding to them) and stick them in the environment. + my @had_breakpoints = keys %had_breakpoints; + set_list( "PERLDB_VISITED", @had_breakpoints ); + + # Save the debugger options we chose. + set_list( "PERLDB_OPT", %option ); + # set_list( "PERLDB_OPT", options2remember() ); + + # Save the break-on-loads. + set_list( "PERLDB_ON_LOAD", %break_on_load ); + +=pod + +The most complex part of this is the saving of all of the breakpoints. They +can live in an awful lot of places, and we have to go through all of them, +find the breakpoints, and then save them in the appropriate environment +variable via C<DB::set_list>. + +=cut + + # Go through all the breakpoints and make sure they're + # still valid. + my @hard; + for ( 0 .. $#had_breakpoints ) { + + # We were in this file. + my $file = $had_breakpoints[$_]; + + # Grab that file's magic line hash. + *dbline = $main::{ '_<' . $file }; + + # Skip out if it doesn't exist, or if the breakpoint + # is in a postponed file (we'll do postponed ones + # later). + next unless %dbline or $postponed_file{$file}; + + # In an eval. This is a little harder, so we'll + # do more processing on that below. + ( push @hard, $file ), next + if $file =~ /^\(\w*eval/; + + # XXX I have no idea what this is doing. Yet. + my @add; + @add = %{ $postponed_file{$file} } + if $postponed_file{$file}; + + # Save the list of all the breakpoints for this file. + set_list( "PERLDB_FILE_$_", %dbline, @add ); + } ## end for (0 .. $#had_breakpoints) + + # The breakpoint was inside an eval. This is a little + # more difficult. XXX and I don't understand it. + for (@hard) { + # Get over to the eval in question. + *dbline = $main::{ '_<' . $_ }; + my ( $quoted, $sub, %subs, $line ) = quotemeta $_; + for $sub ( keys %sub ) { + next unless $sub{$sub} =~ /^$quoted:(\d+)-(\d+)$/; + $subs{$sub} = [ $1, $2 ]; + } + unless (%subs) { + print $OUT + "No subroutines in $_, ignoring breakpoints.\n"; + next; + } + LINES: for $line ( keys %dbline ) { + + # One breakpoint per sub only: + my ( $offset, $sub, $found ); + SUBS: for $sub ( keys %subs ) { + if ( + $subs{$sub}->[1] >= + $line # Not after the subroutine + and ( + not defined $offset # Not caught + or $offset < 0 + ) + ) + { # or badly caught + $found = $sub; + $offset = $line - $subs{$sub}->[0]; + $offset = "+$offset", last SUBS + if $offset >= 0; + } ## end if ($subs{$sub}->[1] >=... + } ## end for $sub (keys %subs) + if ( defined $offset ) { + $postponed{$found} = + "break $offset if $dbline{$line}"; + } + else { + print $OUT +"Breakpoint in $_:$line ignored: after all the subroutines.\n"; + } + } ## end for $line (keys %dbline) + } ## end for (@hard) + + # Save the other things that don't need to be + # processed. + set_list( "PERLDB_POSTPONE", %postponed ); + set_list( "PERLDB_PRETYPE", @$pretype ); + set_list( "PERLDB_PRE", @$pre ); + set_list( "PERLDB_POST", @$post ); + set_list( "PERLDB_TYPEAHEAD", @typeahead ); + + # We are oficially restarting. + $ENV{PERLDB_RESTART} = 1; + + # We are junking all child debuggers. + delete $ENV{PERLDB_PIDS}; # Restore ini state + + # Set this back to the initial pid. + $ENV{PERLDB_PIDS} = $ini_pids if defined $ini_pids; + +=pod + +After all the debugger status has been saved, we take the command we built up +and then return it, so we can C<exec()> it. The debugger will spot the +C<PERLDB_RESTART> environment variable and realize it needs to reload its state +from the environment. + +=cut + + # And run Perl again. Add the "-d" flag, all the + # flags we built up, the script (whether a one-liner + # or a file), add on the -emacs flag for a slave editor, + # and then the old arguments. + + return ($^X, '-d', @flags, @script, ($slave_editor ? '-emacs' : ()), @ARGS); + +}; # end restart + +=back + +=head1 END PROCESSING - THE C<END> BLOCK + +Come here at the very end of processing. We want to go into a +loop where we allow the user to enter commands and interact with the +debugger, but we don't want anything else to execute. + +First we set the C<$finished> variable, so that some commands that +shouldn't be run after the end of program quit working. + +We then figure out whether we're truly done (as in the user entered a C<q> +command, or we finished execution while running nonstop). If we aren't, +we set C<$single> to 1 (causing the debugger to get control again). + +We then call C<DB::fake::at_exit()>, which returns the C<Use 'q' to quit ...> +message and returns control to the debugger. Repeat. + +When the user finally enters a C<q> command, C<$fall_off_end> is set to +1 and the C<END> block simply exits with C<$single> set to 0 (don't +break, run to completion.). + +=cut + +END { + $finished = 1 if $inhibit_exit; # So that some commands may be disabled. + $fall_off_end = 1 unless $inhibit_exit; + + # Do not stop in at_exit() and destructors on exit: + if ($fall_off_end or $runnonstop) { + &save_hist(); + } else { + $DB::single = 1; + DB::fake::at_exit(); + } +} ## end END + +=head1 PRE-5.8 COMMANDS + +Some of the commands changed function quite a bit in the 5.8 command +realignment, so much so that the old code had to be replaced completely. +Because we wanted to retain the option of being able to go back to the +former command set, we moved the old code off to this section. + +There's an awful lot of duplicated code here. We've duplicated the +comments to keep things clear. + +=head2 Null command + +Does nothing. Used to I<turn off> commands. + +=cut + +sub cmd_pre580_null { + + # do nothing... +} + +=head2 Old C<a> command. + +This version added actions if you supplied them, and deleted them +if you didn't. + +=cut + +sub cmd_pre580_a { + my $xcmd = shift; + my $cmd = shift; + + # Argument supplied. Add the action. + if ( $cmd =~ /^(\d*)\s*(.*)/ ) { + + # If the line isn't there, use the current line. + $i = $1 || $line; + $j = $2; + + # If there is an action ... + if ( length $j ) { + + # ... but the line isn't breakable, skip it. + if ( $dbline[$i] == 0 ) { + print $OUT "Line $i may not have an action.\n"; + } + else { + + # ... and the line is breakable: + # Mark that there's an action in this file. + $had_breakpoints{$filename} |= 2; + + # Delete any current action. + $dbline{$i} =~ s/\0[^\0]*//; + + # Add the new action, continuing the line as needed. + $dbline{$i} .= "\0" . action($j); + } + } ## end if (length $j) + + # No action supplied. + else { + + # Delete the action. + $dbline{$i} =~ s/\0[^\0]*//; + + # Mark as having no break or action if nothing's left. + delete $dbline{$i} if $dbline{$i} eq ''; + } + } ## end if ($cmd =~ /^(\d*)\s*(.*)/) +} ## end sub cmd_pre580_a + +=head2 Old C<b> command + +Add breakpoints. + +=cut + +sub cmd_pre580_b { + my $xcmd = shift; + my $cmd = shift; + my $dbline = shift; + + # Break on load. + if ( $cmd =~ /^load\b\s*(.*)/ ) { + my $file = $1; + $file =~ s/\s+$//; + &cmd_b_load($file); + } + + # b compile|postpone <some sub> [<condition>] + # The interpreter actually traps this one for us; we just put the + # necessary condition in the %postponed hash. + elsif ( $cmd =~ /^(postpone|compile)\b\s*([':A-Za-z_][':\w]*)\s*(.*)/ ) { + + # Capture the condition if there is one. Make it true if none. + my $cond = length $3 ? $3 : '1'; + + # Save the sub name and set $break to 1 if $1 was 'postpone', 0 + # if it was 'compile'. + my ( $subname, $break ) = ( $2, $1 eq 'postpone' ); + + # De-Perl4-ify the name - ' separators to ::. + $subname =~ s/\'/::/g; + + # Qualify it into the current package unless it's already qualified. + $subname = "${'package'}::" . $subname + unless $subname =~ /::/; + + # Add main if it starts with ::. + $subname = "main" . $subname if substr( $subname, 0, 2 ) eq "::"; + + # Save the break type for this sub. + $postponed{$subname} = $break ? "break +0 if $cond" : "compile"; + } ## end elsif ($cmd =~ ... + + # b <sub name> [<condition>] + elsif ( $cmd =~ /^([':A-Za-z_][':\w]*(?:\[.*\])?)\s*(.*)/ ) { + my $subname = $1; + my $cond = length $2 ? $2 : '1'; + &cmd_b_sub( $subname, $cond ); + } + + # b <line> [<condition>]. + elsif ( $cmd =~ /^(\d*)\s*(.*)/ ) { + my $i = $1 || $dbline; + my $cond = length $2 ? $2 : '1'; + &cmd_b_line( $i, $cond ); + } +} ## end sub cmd_pre580_b + +=head2 Old C<D> command. + +Delete all breakpoints unconditionally. + +=cut + +sub cmd_pre580_D { + my $xcmd = shift; + my $cmd = shift; + if ( $cmd =~ /^\s*$/ ) { + print $OUT "Deleting all breakpoints...\n"; + + # %had_breakpoints lists every file that had at least one + # breakpoint in it. + my $file; + for $file ( keys %had_breakpoints ) { + + # Switch to the desired file temporarily. + local *dbline = $main::{ '_<' . $file }; + + my $max = $#dbline; + my $was; + + # For all lines in this file ... + for ( $i = 1 ; $i <= $max ; $i++ ) { + + # If there's a breakpoint or action on this line ... + if ( defined $dbline{$i} ) { + + # ... remove the breakpoint. + $dbline{$i} =~ s/^[^\0]+//; + if ( $dbline{$i} =~ s/^\0?$// ) { + + # Remove the entry altogether if no action is there. + delete $dbline{$i}; + } + } ## end if (defined $dbline{$i... + } ## end for ($i = 1 ; $i <= $max... + + # If, after we turn off the "there were breakpoints in this file" + # bit, the entry in %had_breakpoints for this file is zero, + # we should remove this file from the hash. + if ( not $had_breakpoints{$file} &= ~1 ) { + delete $had_breakpoints{$file}; + } + } ## end for $file (keys %had_breakpoints) + + # Kill off all the other breakpoints that are waiting for files that + # haven't been loaded yet. + undef %postponed; + undef %postponed_file; + undef %break_on_load; + } ## end if ($cmd =~ /^\s*$/) +} ## end sub cmd_pre580_D + +=head2 Old C<h> command + +Print help. Defaults to printing the long-form help; the 5.8 version +prints the summary by default. + +=cut + +sub cmd_pre580_h { + my $xcmd = shift; + my $cmd = shift; + + # Print the *right* help, long format. + if ( $cmd =~ /^\s*$/ ) { + print_help($pre580_help); + } + + # 'h h' - explicitly-requested summary. + elsif ( $cmd =~ /^h\s*/ ) { + print_help($pre580_summary); + } + + # Find and print a command's help. + elsif ( $cmd =~ /^h\s+(\S.*)$/ ) { + my $asked = $1; # for proper errmsg + my $qasked = quotemeta($asked); # for searching + # XXX: finds CR but not <CR> + if ( + $pre580_help =~ /^ + <? # Optional '<' + (?:[IB]<) # Optional markup + $qasked # The command name + /mx + ) + { + + while ( + $pre580_help =~ /^ + ( # The command help: + <? # Optional '<' + (?:[IB]<) # Optional markup + $qasked # The command name + ([\s\S]*?) # Lines starting with tabs + \n # Final newline + ) + (?!\s)/mgx + ) # Line not starting with space + # (Next command's help) + { + print_help($1); + } + } ## end if ($pre580_help =~ /^<?(?:[IB]<)$qasked/m) + + # Help not found. + else { + print_help("B<$asked> is not a debugger command.\n"); + } + } ## end elsif ($cmd =~ /^h\s+(\S.*)$/) +} ## end sub cmd_pre580_h + +=head2 Old C<W> command + +C<W E<lt>exprE<gt>> adds a watch expression, C<W> deletes them all. + +=cut + +sub cmd_pre580_W { + my $xcmd = shift; + my $cmd = shift; + + # Delete all watch expressions. + if ( $cmd =~ /^$/ ) { + + # No watching is going on. + $trace &= ~2; + + # Kill all the watch expressions and values. + @to_watch = @old_watch = (); + } + + # Add a watch expression. + elsif ( $cmd =~ /^(.*)/s ) { + + # add it to the list to be watched. + push @to_watch, $1; + + # Get the current value of the expression. + # Doesn't handle expressions returning list values! + $evalarg = $1; + my ($val) = &eval; + $val = ( defined $val ) ? "'$val'" : 'undef'; + + # Save it. + push @old_watch, $val; + + # We're watching stuff. + $trace |= 2; + + } ## end elsif ($cmd =~ /^(.*)/s) +} ## end sub cmd_pre580_W + +=head1 PRE-AND-POST-PROMPT COMMANDS AND ACTIONS + +The debugger used to have a bunch of nearly-identical code to handle +the pre-and-post-prompt action commands. C<cmd_pre590_prepost> and +C<cmd_prepost> unify all this into one set of code to handle the +appropriate actions. + +=head2 C<cmd_pre590_prepost> + +A small wrapper around C<cmd_prepost>; it makes sure that the default doesn't +do something destructive. In pre 5.8 debuggers, the default action was to +delete all the actions. + +=cut + +sub cmd_pre590_prepost { + my $cmd = shift; + my $line = shift || '*'; + my $dbline = shift; + + return &cmd_prepost( $cmd, $line, $dbline ); +} ## end sub cmd_pre590_prepost + +=head2 C<cmd_prepost> + +Actually does all the handling for C<E<lt>>, C<E<gt>>, C<{{>, C<{>, etc. +Since the lists of actions are all held in arrays that are pointed to by +references anyway, all we have to do is pick the right array reference and +then use generic code to all, delete, or list actions. + +=cut + +sub cmd_prepost { + my $cmd = shift; + + # No action supplied defaults to 'list'. + my $line = shift || '?'; + + # Figure out what to put in the prompt. + my $which = ''; + + # Make sure we have some array or another to address later. + # This means that if ssome reason the tests fail, we won't be + # trying to stash actions or delete them from the wrong place. + my $aref = []; + + # < - Perl code to run before prompt. + if ( $cmd =~ /^\</o ) { + $which = 'pre-perl'; + $aref = $pre; + } + + # > - Perl code to run after prompt. + elsif ( $cmd =~ /^\>/o ) { + $which = 'post-perl'; + $aref = $post; + } + + # { - first check for properly-balanced braces. + elsif ( $cmd =~ /^\{/o ) { + if ( $cmd =~ /^\{.*\}$/o && unbalanced( substr( $cmd, 1 ) ) ) { + print $OUT +"$cmd is now a debugger command\nuse `;$cmd' if you mean Perl code\n"; + } + + # Properly balanced. Pre-prompt debugger actions. + else { + $which = 'pre-debugger'; + $aref = $pretype; + } + } ## end elsif ( $cmd =~ /^\{/o ) + + # Did we find something that makes sense? + unless ($which) { + print $OUT "Confused by command: $cmd\n"; + } + + # Yes. + else { + + # List actions. + if ( $line =~ /^\s*\?\s*$/o ) { + unless (@$aref) { + + # Nothing there. Complain. + print $OUT "No $which actions.\n"; + } + else { + + # List the actions in the selected list. + print $OUT "$which commands:\n"; + foreach my $action (@$aref) { + print $OUT "\t$cmd -- $action\n"; + } + } ## end else + } ## end if ( $line =~ /^\s*\?\s*$/o) + + # Might be a delete. + else { + if ( length($cmd) == 1 ) { + if ( $line =~ /^\s*\*\s*$/o ) { + + # It's a delete. Get rid of the old actions in the + # selected list.. + @$aref = (); + print $OUT "All $cmd actions cleared.\n"; + } + else { + + # Replace all the actions. (This is a <, >, or {). + @$aref = action($line); + } + } ## end if ( length($cmd) == 1) + elsif ( length($cmd) == 2 ) { + + # Add the action to the line. (This is a <<, >>, or {{). + push @$aref, action($line); + } + else { + + # <<<, >>>>, {{{{{{ ... something not a command. + print $OUT + "Confused by strange length of $which command($cmd)...\n"; + } + } ## end else [ if ( $line =~ /^\s*\?\s*$/o) + } ## end else +} ## end sub cmd_prepost + +=head1 C<DB::fake> + +Contains the C<at_exit> routine that the debugger uses to issue the +C<Debugged program terminated ...> message after the program completes. See +the C<END> block documentation for more details. + +=cut + +package DB::fake; + +sub at_exit { + "Debugged program terminated. Use `q' to quit or `R' to restart."; +} + +package DB; # Do not trace this 1; below! + +1; + + |