+# Carp::Heavy uses some variables in common with Carp.
package Carp;
=head1 NAME
-Carp::Heavy - Carp guts
+Carp heavy machinery - no user serviceable parts inside
-=head1 SYNOPIS
+=cut
-(internal use only)
+# use strict; # not yet
+
+# On one line so MakeMaker will see it.
+use Carp; our $VERSION = $Carp::VERSION;
+
+our ($CarpLevel, $MaxArgNums, $MaxEvalLen, $MaxArgLen, $Verbose);
+
+sub caller_info {
+ my $i = shift(@_) + 1;
+ package DB;
+ my %call_info;
+ @call_info{
+ qw(pack file line sub has_args wantarray evaltext is_require)
+ } = caller($i);
+
+ unless (defined $call_info{pack}) {
+ return ();
+ }
+
+ my $sub_name = Carp::get_subname(\%call_info);
+ if ($call_info{has_args}) {
+ my @args = map {Carp::format_arg($_)} @DB::args;
+ if ($MaxArgNums and @args > $MaxArgNums) { # More than we want to show?
+ $#args = $MaxArgNums;
+ push @args, '...';
+ }
+ # Push the args onto the subroutine
+ $sub_name .= '(' . join (',', @args) . ')';
+ }
+ $call_info{sub_name} = $sub_name;
+ return wantarray() ? %call_info : \%call_info;
+}
-=head1 DESCRIPTION
+# Transform an argument to a function into a string.
+sub format_arg {
+ my $arg = shift;
+ if (not defined($arg)) {
+ $arg = 'undef';
+ }
+ elsif (ref($arg)) {
+ $arg = defined($overload::VERSION) ? overload::StrVal($arg) : "$arg";
+ }
+ $arg =~ s/'/\\'/g;
+ $arg = str_len_trim($arg, $MaxArgLen);
+
+ # Quote it?
+ $arg = "'$arg'" unless $arg =~ /^-?[\d.]+\z/;
+
+ # The following handling of "control chars" is direct from
+ # the original code - I think it is broken on Unicode though.
+ # Suggestions?
+ $arg =~ s/([[:cntrl:]]|[[:^ascii:]])/sprintf("\\x{%x}",ord($1))/eg;
+ return $arg;
+}
-No user-serviceable parts inside.
+# Takes an inheritance cache and a package and returns
+# an anon hash of known inheritances and anon array of
+# inheritances which consequences have not been figured
+# for.
+sub get_status {
+ my $cache = shift;
+ my $pkg = shift;
+ $cache->{$pkg} ||= [{$pkg => $pkg}, [trusts_directly($pkg)]];
+ return @{$cache->{$pkg}};
+}
-=cut
+# Takes the info from caller() and figures out the name of
+# the sub/require/eval
+sub get_subname {
+ my $info = shift;
+ if (defined($info->{evaltext})) {
+ my $eval = $info->{evaltext};
+ if ($info->{is_require}) {
+ return "require $eval";
+ }
+ else {
+ $eval =~ s/([\\\'])/\\$1/g;
+ return "eval '" . str_len_trim($eval, $MaxEvalLen) . "'";
+ }
+ }
-# This package is heavily used. Be small. Be fast. Be good.
+ return ($info->{sub} eq '(eval)') ? 'eval {...}' : $info->{sub};
+}
-# Comments added by Andy Wardley <abw@kfs.org> 09-Apr-98, based on an
-# _almost_ complete understanding of the package. Corrections and
-# comments are welcome.
+# Figures out what call (from the point of view of the caller)
+# the long error backtrace should start at.
+sub long_error_loc {
+ my $i;
+ my $lvl = $CarpLevel;
+ {
+ my $pkg = caller(++$i);
+ unless(defined($pkg)) {
+ # This *shouldn't* happen.
+ if (%Internal) {
+ local %Internal;
+ $i = long_error_loc();
+ last;
+ }
+ else {
+ # OK, now I am irritated.
+ return 2;
+ }
+ }
+ redo if $CarpInternal{$pkg};
+ redo unless 0 > --$lvl;
+ redo if $Internal{$pkg};
+ }
+ return $i - 1;
+}
-# longmess() crawls all the way up the stack reporting on all the function
-# calls made. The error string, $error, is originally constructed from the
-# arguments passed into longmess() via confess(), cluck() or shortmess().
-# This gets appended with the stack trace messages which are generated for
-# each function call on the stack.
sub longmess_heavy {
- return @_ if ref $_[0];
- my $error = join '', @_;
- my $mess = "";
- my $i = 1 + $CarpLevel;
- my ($pack,$file,$line,$sub,$hargs,$eval,$require);
- my (@a);
- #
- # crawl up the stack....
- #
- while (do { { package DB; @a = caller($i++) } } ) {
- # get copies of the variables returned from caller()
- ($pack,$file,$line,$sub,$hargs,undef,$eval,$require) = @a;
- #
- # if the $error error string is newline terminated then it
- # is copied into $mess. Otherwise, $mess gets set (at the end of
- # the 'else {' section below) to one of two things. The first time
- # through, it is set to the "$error at $file line $line" message.
- # $error is then set to 'called' which triggers subsequent loop
- # iterations to append $sub to $mess before appending the "$error
- # at $file line $line" which now actually reads "called at $file line
- # $line". Thus, the stack trace message is constructed:
- #
- # first time: $mess = $error at $file line $line
- # subsequent times: $mess .= $sub $error at $file line $line
- # ^^^^^^
- # "called"
- if ($error =~ m/\n$/) {
- $mess .= $error;
- } else {
- # Build a string, $sub, which names the sub-routine called.
- # This may also be "require ...", "eval '...' or "eval {...}"
- if (defined $eval) {
- if ($require) {
- $sub = "require $eval";
- } else {
- $eval =~ s/([\\\'])/\\$1/g;
- if ($MaxEvalLen && length($eval) > $MaxEvalLen) {
- substr($eval,$MaxEvalLen) = '...';
- }
- $sub = "eval '$eval'";
- }
- } elsif ($sub eq '(eval)') {
- $sub = 'eval {...}';
- }
- # if there are any arguments in the sub-routine call, format
- # them according to the format variables defined earlier in
- # this file and join them onto the $sub sub-routine string
- if ($hargs) {
- # we may trash some of the args so we take a copy
- @a = @DB::args; # must get local copy of args
- # don't print any more than $MaxArgNums
- if ($MaxArgNums and @a > $MaxArgNums) {
- # cap the length of $#a and set the last element to '...'
- $#a = $MaxArgNums;
- $a[$#a] = "...";
- }
- for (@a) {
- # set args to the string "undef" if undefined
- $_ = "undef", next unless defined $_;
- if (ref $_) {
- # force reference to string representation
- $_ .= '';
- s/'/\\'/g;
- }
- else {
- s/'/\\'/g;
- # terminate the string early with '...' if too long
- substr($_,$MaxArgLen) = '...'
- if $MaxArgLen and $MaxArgLen < length;
- }
- # 'quote' arg unless it looks like a number
- $_ = "'$_'" unless /^-?[\d.]+$/;
- # print high-end chars as 'M-<char>'
- s/([\200-\377])/sprintf("M-%c",ord($1)&0177)/eg;
- # print remaining control chars as ^<char>
- s/([\0-\37\177])/sprintf("^%c",ord($1)^64)/eg;
- }
- # append ('all', 'the', 'arguments') to the $sub string
- $sub .= '(' . join(', ', @a) . ')';
- }
- # here's where the error message, $mess, gets constructed
- $mess .= "\t$sub " if $error eq "called";
- $mess .= "$error at $file line $line";
- if (defined &Thread::tid) {
- my $tid = Thread->self->tid;
- $mess .= " thread $tid" if $tid;
- }
- $mess .= "\n";
- }
- # we don't need to print the actual error message again so we can
- # change this to "called" so that the string "$error at $file line
- # $line" makes sense as "called at $file line $line".
- $error = "called";
- }
- # this kludge circumvents die's incorrect handling of NUL
- my $msg = \($mess || $error);
- $$msg =~ tr/\0//d;
- $$msg;
+ return @_ if ref($_[0]); # don't break references as exceptions
+ my $i = long_error_loc();
+ return ret_backtrace($i, @_);
}
+# Returns a full stack backtrace starting from where it is
+# told.
+sub ret_backtrace {
+ my ($i, @error) = @_;
+ my $mess;
+ my $err = join '', @error;
+ $i++;
+
+ my $tid_msg = '';
+ if (defined &Thread::tid) {
+ my $tid = Thread->self->tid;
+ $tid_msg = " thread $tid" if $tid;
+ }
+
+ { if ($err =~ /\n$/) { # extra block to localise $1 etc
+ $mess = $err;
+ }
+ else {
+ my %i = caller_info($i);
+ $mess = "$err at $i{file} line $i{line}$tid_msg\n";
+ }}
+
+ while (my %i = caller_info(++$i)) {
+ $mess .= "\t$i{sub_name} called at $i{file} line $i{line}$tid_msg\n";
+ }
+
+ return $mess;
+}
-# ancestors() returns the complete set of ancestors of a module
-
-sub ancestors($$);
-
-sub ancestors($$){
- my( $pack, $href ) = @_;
- if( @{"${pack}::ISA"} ){
- my $risa = \@{"${pack}::ISA"};
- my %tree = ();
- @tree{@$risa} = ();
- foreach my $mod ( @$risa ){
- # visit ancestors - if not already in the gallery
- if( ! defined( $$href{$mod} ) ){
- my @ancs = ancestors( $mod, $href );
- @tree{@ancs} = ();
- }
- }
- return ( keys( %tree ) );
- } else {
- return ();
- }
+sub ret_summary {
+ my ($i, @error) = @_;
+ my $mess;
+ my $err = join '', @error;
+ $i++;
+
+ my $tid_msg = '';
+ if (defined &Thread::tid) {
+ my $tid = Thread->self->tid;
+ $tid_msg = " thread $tid" if $tid;
+ }
+
+ my %i = caller_info($i);
+ return "$err at $i{file} line $i{line}$tid_msg\n";
+}
+
+
+sub short_error_loc {
+ my $cache;
+ my $i = 1;
+ my $lvl = $CarpLevel;
+ {
+ my $called = caller($i++);
+ my $caller = caller($i);
+ return 0 unless defined($caller); # What happened?
+ redo if $Internal{$caller};
+ redo if $CarpInternal{$called};
+ redo if trusts($called, $caller, $cache);
+ redo if trusts($caller, $called, $cache);
+ redo unless 0 > --$lvl;
+ }
+ return $i - 1;
+}
+
+sub shortmess_heavy {
+ return longmess_heavy(@_) if $Verbose;
+ return @_ if ref($_[0]); # don't break references as exceptions
+ my $i = short_error_loc();
+ if ($i) {
+ ret_summary($i, @_);
+ }
+ else {
+ longmess_heavy(@_);
+ }
}
+# If a string is too long, trims it with ...
+sub str_len_trim {
+ my $str = shift;
+ my $max = shift || 0;
+ if (2 < $max and $max < length($str)) {
+ substr($str, $max - 3) = '...';
+ }
+ return $str;
+}
-# shortmess() is called by carp() and croak() to skip all the way up to
-# the top-level caller's package and report the error from there. confess()
-# and cluck() generate a full stack trace so they call longmess() to
-# generate that. In verbose mode shortmess() calls longmess() so
-# you always get a stack trace
-
-sub shortmess_heavy { # Short-circuit &longmess if called via multiple packages
- goto &longmess_heavy if $Verbose;
- return @_ if ref $_[0];
- my $error = join '', @_;
- my ($prevpack) = caller(1);
- my $extra = $CarpLevel;
-
- my @Clans = ( $prevpack );
- my $i = 2;
- my ($pack,$file,$line);
- # when reporting an error, we want to report it from the context of the
- # calling package. So what is the calling package? Within a module,
- # there may be many calls between methods and perhaps between sub-classes
- # and super-classes, but the user isn't interested in what happens
- # inside the package. We start by building a hash array which keeps
- # track of all the packages to which the calling package belongs. We
- # do this by examining its @ISA variable. Any call from a base class
- # method (one of our caller's @ISA packages) can be ignored
- my %isa;
-
- # merge all the caller's @ISA packages and ancestors into %isa.
- my @pars = ancestors( $prevpack, \%isa );
- @isa{@pars} = () if @pars;
- $isa{$prevpack} = 1;
-
- # now we crawl up the calling stack and look at all the packages in
- # there. For each package, we look to see if it has an @ISA and then
- # we see if our caller features in that list. That would imply that
- # our caller is a derived class of that package and its calls can also
- # be ignored
-CALLER:
- while (($pack,$file,$line) = caller($i++)) {
-
- # Chances are, the caller's caller (or its caller...) is already
- # in the gallery - if so, ignore this caller.
- next if exists( $isa{$pack} );
-
- # no: collect this module's ancestors.
- my @i = ancestors( $pack, \%isa );
- my %i;
- if( @i ){
- @i{@i} = ();
- # check whether our representative of one of the clans is
- # in this family tree.
- foreach my $cl (@Clans){
- if( exists( $i{$cl} ) ){
- # yes: merge all of the family tree into %isa
- @isa{@i,$pack} = ();
- # and here's where we do some more ignoring...
- # if the package in question is one of our caller's
- # base or derived packages then we can ignore it (skip it)
- # and go onto the next.
- next CALLER if exists( $isa{$pack} );
- last;
- }
- }
- }
-
- # Hey! We've found a package that isn't one of our caller's
- # clan....but wait, $extra refers to the number of 'extra' levels
- # we should skip up. If $extra > 0 then this is a false alarm.
- # We must merge the package into the %isa hash (so we can ignore it
- # if it pops up again), decrement $extra, and continue.
- if ($extra-- > 0) {
- push( @Clans, $pack );
- @isa{@i,$pack} = ();
- }
- else {
- # OK! We've got a candidate package. Time to construct the
- # relevant error message and return it. die() doesn't like
- # to be given NUL characters (which $msg may contain) so we
- # remove them first.
- my $msg;
- $msg = "$error at $file line $line";
- if (defined &Thread::tid) {
- my $tid = Thread->self->tid;
- $mess .= " thread $tid" if $tid;
- }
- $msg .= "\n";
- $msg =~ tr/\0//d;
- return $msg;
- }
+# Takes two packages and an optional cache. Says whether the
+# first inherits from the second.
+#
+# Recursive versions of this have to work to avoid certain
+# possible endless loops, and when following long chains of
+# inheritance are less efficient.
+sub trusts {
+ my $child = shift;
+ my $parent = shift;
+ my $cache = shift || {};
+ my ($known, $partial) = get_status($cache, $child);
+ # Figure out consequences until we have an answer
+ while (@$partial and not exists $known->{$parent}) {
+ my $anc = shift @$partial;
+ next if exists $known->{$anc};
+ $known->{$anc}++;
+ my ($anc_knows, $anc_partial) = get_status($cache, $anc);
+ my @found = keys %$anc_knows;
+ @$known{@found} = ();
+ push @$partial, @$anc_partial;
}
+ return exists $known->{$parent};
+}
- # uh-oh! It looks like we crawled all the way up the stack and
- # never found a candidate package. Oh well, let's call longmess
- # to generate a full stack trace. We use the magical form of 'goto'
- # so that this shortmess() function doesn't appear on the stack
- # to further confuse longmess() about it's calling package.
- goto &longmess_heavy;
+# Takes a package and gives a list of those trusted directly
+sub trusts_directly {
+ my $class = shift;
+ no strict 'refs';
+ no warnings 'once';
+ return @{"$class\::CARP_NOT"}
+ ? @{"$class\::CARP_NOT"}
+ : @{"$class\::ISA"};
}
1;
+