package Carp;
-our $VERSION = '1.06';
-# this file is an utra-lightweight stub. The first time a function is
-# called, Carp::Heavy is loaded, and the real short/longmessmess_jmp
-# subs are installed
+our $VERSION = '1.16';
our $MaxEvalLen = 0;
our $Verbose = 0;
our @EXPORT_OK = qw(cluck verbose longmess shortmess);
our @EXPORT_FAIL = qw(verbose); # hook to enable verbose mode
+# The members of %Internal are packages that are internal to perl.
+# Carp will not report errors from within these packages if it
+# can. The members of %CarpInternal are internal to Perl's warning
+# system. Carp will not report errors from within these packages
+# either, and will not report calls *to* these packages for carp and
+# croak. They replace $CarpLevel, which is deprecated. The
+# $Max(EvalLen|(Arg(Len|Nums)) variables are used to specify how the eval
+# text and function arguments should be formatted when printed.
+
+# disable these by default, so they can live w/o require Carp
+$CarpInternal{Carp}++;
+$CarpInternal{warnings}++;
+$Internal{Exporter}++;
+$Internal{'Exporter::Heavy'}++;
+
# if the caller specifies verbose usage ("perl -MCarp=verbose script.pl")
# then the following method will be called by the Exporter which knows
# to do this thanks to @EXPORT_FAIL, above. $_[1] will contain the word
sub export_fail { shift; $Verbose = shift if $_[0] eq 'verbose'; @_ }
-# fixed hooks for stashes to point to
-sub longmess { goto &longmess_jmp }
-sub shortmess { goto &shortmess_jmp }
-# these two are replaced when Carp::Heavy is loaded
-sub longmess_jmp {
- local($@, $!);
- eval { require Carp::Heavy };
- return $@ if $@;
- goto &longmess_jmp;
-}
-sub shortmess_jmp {
- local($@, $!);
- eval { require Carp::Heavy };
- return $@ if $@;
- goto &shortmess_jmp;
-}
+sub longmess {
+ # Icky backwards compatibility wrapper. :-(
+ #
+ # The story is that the original implementation hard-coded the
+ # number of call levels to go back, so calls to longmess were off
+ # by one. Other code began calling longmess and expecting this
+ # behaviour, so the replacement has to emulate that behaviour.
+ my $call_pack = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}() : caller();
+ if ($Internal{$call_pack} or $CarpInternal{$call_pack}) {
+ return longmess_heavy(@_);
+ }
+ else {
+ local $CarpLevel = $CarpLevel + 1;
+ return longmess_heavy(@_);
+ }
+};
+
+sub shortmess {
+ # Icky backwards compatibility wrapper. :-(
+ local @CARP_NOT = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}() : caller();
+ shortmess_heavy(@_);
+};
sub croak { die shortmess @_ }
sub confess { die longmess @_ }
sub carp { warn shortmess @_ }
sub cluck { warn longmess @_ }
+sub caller_info {
+ my $i = shift(@_) + 1;
+ package DB;
+ my %call_info;
+ @call_info{
+ qw(pack file line sub has_args wantarray evaltext is_require)
+ } = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}($i) : 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;
+}
+
+# Transform an argument to a function into a string.
+sub format_arg {
+ my $arg = shift;
+ if (ref($arg)) {
+ $arg = defined($overload::VERSION) ? overload::StrVal($arg) : "$arg";
+ }
+ if (defined($arg)) {
+ $arg =~ s/'/\\'/g;
+ $arg = str_len_trim($arg, $MaxArgLen);
+
+ # Quote it?
+ $arg = "'$arg'" unless $arg =~ /^-?[\d.]+\z/;
+ } else {
+ $arg = 'undef';
+ }
+
+ # The following handling of "control chars" is direct from
+ # the original code - it is broken on Unicode though.
+ # Suggestions?
+ utf8::is_utf8($arg)
+ or $arg =~ s/([[:cntrl:]]|[[:^ascii:]])/sprintf("\\x{%x}",ord($1))/eg;
+ return $arg;
+}
+
+# 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}};
+}
+
+# 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, $MaxEvalLen) . "'";
+ }
+ }
+
+ return ($info->{sub} eq '(eval)') ? 'eval {...}' : $info->{sub};
+}
+
+# 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 = $CarpLevel;
+ {
+ ++$i;
+ my $pkg = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}($i) : 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 $i - 1;
+}
+
+
+sub longmess_heavy {
+ return @_ if ref($_[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 &threads::tid) {
+ my $tid = threads->tid;
+ $tid_msg = " thread $tid" if $tid;
+ }
+
+ my %i = caller_info($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 $mess;
+}
+
+sub ret_summary {
+ my ($i, @error) = @_;
+ my $err = join '', @error;
+ $i++;
+
+ my $tid_msg = '';
+ if (defined &threads::tid) {
+ my $tid = threads->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 {
+ # You have to create your (hash)ref out here, rather than defaulting it
+ # inside trusts *on a lexical*, as you want it to persist across calls.
+ # (You can default it on $_[2], but that gets messy)
+ my $cache = {};
+ my $i = 1;
+ my $lvl = $CarpLevel;
+ {
+
+ my $called = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}($i) : caller($i);
+ $i++;
+ my $caller = defined &{"CORE::GLOBAL::caller"} ? &{"CORE::GLOBAL::caller"}($i) : caller($i);
+
+ return 0 unless defined($caller); # What happened?
+ redo if $Internal{$caller};
+ redo if $CarpInternal{$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;
+}
+
+# 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};
+}
+
+# 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;
+
__END__
=head1 NAME
changing some global variables in the C<Carp> namespace. See the
section on C<GLOBAL VARIABLES> below.
-Here is a more complete description of how c<carp> and c<croak> work.
+Here is a more complete description of how C<carp> and C<croak> work.
What they do is search the call-stack for a function call stack where
they have not been told that there shouldn't be an error. If every
call is marked safe, they give up and give a full stack backtrace
perl -MCarp=verbose script.pl
-or by including the string C<MCarp=verbose> in the PERL5OPT
+or by including the string C<-MCarp=verbose> in the PERL5OPT
environment variable.
Alternately, you can set the global variable C<$Carp::Verbose> to true.
=head2 $Carp::Verbose
-This variable makes C<carp> and C<cluck> generate stack backtraces
+This variable makes C<carp> and C<croak> generate stack backtraces
just like C<cluck> and C<confess>. This is how C<use Carp 'verbose'>
is implemented internally.
Defaults to C<0>.
+=head2 @CARP_NOT
+
+This variable, I<in your package>, says which packages are I<not> to be
+considered as the location of an error. The C<carp()> and C<cluck()>
+functions will skip over callers when reporting where an error occurred.
+
+NB: This variable must be in the package's symbol table, thus:
+
+ # These work
+ our @CARP_NOT; # file scope
+ use vars qw(@CARP_NOT); # package scope
+ @My::Package::CARP_NOT = ... ; # explicit package variable
+
+ # These don't work
+ sub xyz { ... @CARP_NOT = ... } # w/o declarations above
+ my @CARP_NOT; # even at top-level
+
+Example of use:
+
+ package My::Carping::Package;
+ use Carp;
+ our @CARP_NOT;
+ sub bar { .... or _error('Wrong input') }
+ sub _error {
+ # temporary control of where'ness, __PACKAGE__ is implicit
+ local @CARP_NOT = qw(My::Friendly::Caller);
+ carp(@_)
+ }
+
+This would make C<Carp> report the error as coming from a caller not
+in C<My::Carping::Package>, nor from C<My::Friendly::Caller>.
+
+Also read the L</DESCRIPTION> section above, about how C<Carp> decides
+where the error is reported from.
+
+Use C<@CARP_NOT>, instead of C<$Carp::CarpLevel>.
+
+Overrides C<Carp>'s use of C<@ISA>.
+
=head2 %Carp::Internal
This says what packages are internal to Perl. C<Carp> will never
report an error as being from a line in a package that is internal to
Perl. For example:
- $Carp::Internal{ __PACKAGE__ }++;
+ $Carp::Internal{ (__PACKAGE__) }++;
# time passes...
sub foo { ... or confess("whatever") };
stack.
Therefore it is best to avoid C<$Carp::CarpLevel>. Instead use
-C<@CARP_NOT>, C<%Carp::Internal> and %Carp::CarpInternal>.
+C<@CARP_NOT>, C<%Carp::Internal> and C<%Carp::CarpInternal>.
Defaults to C<0>.
https://perl5.git.perl.org / perl5.git / blobdiff