1073 lines
35 KiB
Perl
1073 lines
35 KiB
Perl
package Carp;
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{ use 5.006; }
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use strict;
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use warnings;
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BEGIN {
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# Very old versions of warnings.pm load Carp. This can go wrong due
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# to the circular dependency. If warnings is invoked before Carp,
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# then warnings starts by loading Carp, then Carp (above) tries to
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# invoke warnings, and gets nothing because warnings is in the process
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# of loading and hasn't defined its import method yet. If we were
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# only turning on warnings ("use warnings" above) this wouldn't be too
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# bad, because Carp would just gets the state of the -w switch and so
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# might not get some warnings that it wanted. The real problem is
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# that we then want to turn off Unicode warnings, but "no warnings
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# 'utf8'" won't be effective if we're in this circular-dependency
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# situation. So, if warnings.pm is an affected version, we turn
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# off all warnings ourselves by directly setting ${^WARNING_BITS}.
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# On unaffected versions, we turn off just Unicode warnings, via
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# the proper API.
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if(!defined($warnings::VERSION) || eval($warnings::VERSION) < 1.06) {
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${^WARNING_BITS} = "";
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} else {
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"warnings"->unimport("utf8");
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}
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}
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sub _fetch_sub { # fetch sub without autovivifying
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my($pack, $sub) = @_;
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$pack .= '::';
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# only works with top-level packages
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return unless exists($::{$pack});
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for ($::{$pack}) {
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return unless ref \$_ eq 'GLOB' && *$_{HASH} && exists $$_{$sub};
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for ($$_{$sub}) {
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return ref \$_ eq 'GLOB' ? *$_{CODE} : undef
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}
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}
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}
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# UTF8_REGEXP_PROBLEM is a compile-time constant indicating whether Carp
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# must avoid applying a regular expression to an upgraded (is_utf8)
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# string. There are multiple problems, on different Perl versions,
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# that require this to be avoided. All versions prior to 5.13.8 will
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# load utf8_heavy.pl for the swash system, even if the regexp doesn't
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# use character classes. Perl 5.6 and Perls [5.11.2, 5.13.11) exhibit
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# specific problems when Carp is being invoked in the aftermath of a
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# syntax error.
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BEGIN {
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if("$]" < 5.013011) {
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*UTF8_REGEXP_PROBLEM = sub () { 1 };
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} else {
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*UTF8_REGEXP_PROBLEM = sub () { 0 };
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}
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}
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# is_utf8() is essentially the utf8::is_utf8() function, which indicates
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# whether a string is represented in the upgraded form (using UTF-8
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# internally). As utf8::is_utf8() is only available from Perl 5.8
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# onwards, extra effort is required here to make it work on Perl 5.6.
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BEGIN {
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if(defined(my $sub = _fetch_sub utf8 => 'is_utf8')) {
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*is_utf8 = $sub;
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} else {
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# black magic for perl 5.6
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*is_utf8 = sub { unpack("C", "\xaa".$_[0]) != 170 };
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}
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}
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# The downgrade() function defined here is to be used for attempts to
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# downgrade where it is acceptable to fail. It must be called with a
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# second argument that is a true value.
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BEGIN {
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if(defined(my $sub = _fetch_sub utf8 => 'downgrade')) {
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*downgrade = \&{"utf8::downgrade"};
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} else {
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*downgrade = sub {
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my $r = "";
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my $l = length($_[0]);
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for(my $i = 0; $i != $l; $i++) {
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my $o = ord(substr($_[0], $i, 1));
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return if $o > 255;
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$r .= chr($o);
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}
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$_[0] = $r;
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};
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}
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}
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# is_safe_printable_codepoint() indicates whether a character, specified
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# by integer codepoint, is OK to output literally in a trace. Generally
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# this is if it is a printable character in the ancestral character set
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# (ASCII or EBCDIC). This is used on some Perls in situations where a
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# regexp can't be used.
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BEGIN {
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*is_safe_printable_codepoint =
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"$]" >= 5.007_003 ?
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eval(q(sub ($) {
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my $u = utf8::native_to_unicode($_[0]);
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$u >= 0x20 && $u <= 0x7e;
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}))
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: ord("A") == 65 ?
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sub ($) { $_[0] >= 0x20 && $_[0] <= 0x7e }
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:
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sub ($) {
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# Early EBCDIC
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# 3 EBCDIC code pages supported then; all controls but one
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# are the code points below SPACE. The other one is 0x5F on
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# POSIX-BC; FF on the other two.
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# FIXME: there are plenty of unprintable codepoints other
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# than those that this code and the comment above identifies
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# as "controls".
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$_[0] >= ord(" ") && $_[0] <= 0xff &&
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$_[0] != (ord ("^") == 106 ? 0x5f : 0xff);
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}
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;
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}
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sub _univ_mod_loaded {
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return 0 unless exists($::{"UNIVERSAL::"});
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for ($::{"UNIVERSAL::"}) {
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return 0 unless ref \$_ eq "GLOB" && *$_{HASH} && exists $$_{"$_[0]::"};
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for ($$_{"$_[0]::"}) {
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return 0 unless ref \$_ eq "GLOB" && *$_{HASH} && exists $$_{"VERSION"};
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for ($$_{"VERSION"}) {
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return 0 unless ref \$_ eq "GLOB";
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return ${*$_{SCALAR}};
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}
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}
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}
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}
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# _maybe_isa() is usually the UNIVERSAL::isa function. We have to avoid
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# the latter if the UNIVERSAL::isa module has been loaded, to avoid infi-
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# nite recursion; in that case _maybe_isa simply returns true.
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my $isa;
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BEGIN {
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if (_univ_mod_loaded('isa')) {
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*_maybe_isa = sub { 1 }
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}
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else {
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# Since we have already done the check, record $isa for use below
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# when defining _StrVal.
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*_maybe_isa = $isa = _fetch_sub(UNIVERSAL => "isa");
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}
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}
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# We need an overload::StrVal or equivalent function, but we must avoid
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# loading any modules on demand, as Carp is used from __DIE__ handlers and
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# may be invoked after a syntax error.
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# We can copy recent implementations of overload::StrVal and use
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# overloading.pm, which is the fastest implementation, so long as
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# overloading is available. If it is not available, we use our own pure-
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# Perl StrVal. We never actually use overload::StrVal, for various rea-
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# sons described below.
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# overload versions are as follows:
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# undef-1.00 (up to perl 5.8.0) uses bless (avoid!)
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# 1.01-1.17 (perl 5.8.1 to 5.14) uses Scalar::Util
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# 1.18+ (perl 5.16+) uses overloading
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# The ancient 'bless' implementation (that inspires our pure-Perl version)
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# blesses unblessed references and must be avoided. Those using
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# Scalar::Util use refaddr, possibly the pure-Perl implementation, which
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# has the same blessing bug, and must be avoided. Also, Scalar::Util is
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# loaded on demand. Since we avoid the Scalar::Util implementations, we
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# end up having to implement our own overloading.pm-based version for perl
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# 5.10.1 to 5.14. Since it also works just as well in more recent ver-
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# sions, we use it there, too.
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BEGIN {
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if (eval { require "overloading.pm" }) {
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*_StrVal = eval 'sub { no overloading; "$_[0]" }'
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}
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else {
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# Work around the UNIVERSAL::can/isa modules to avoid recursion.
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# _mycan is either UNIVERSAL::can, or, in the presence of an
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# override, overload::mycan.
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*_mycan = _univ_mod_loaded('can')
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? do { require "overload.pm"; _fetch_sub overload => 'mycan' }
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: \&UNIVERSAL::can;
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# _blessed is either UNIVERSAL::isa(...), or, in the presence of an
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# override, a hideous, but fairly reliable, workaround.
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*_blessed = $isa
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? sub { &$isa($_[0], "UNIVERSAL") }
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: sub {
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my $probe = "UNIVERSAL::Carp_probe_" . rand;
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no strict 'refs';
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local *$probe = sub { "unlikely string" };
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local $@;
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local $SIG{__DIE__} = sub{};
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(eval { $_[0]->$probe } || '') eq 'unlikely string'
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};
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*_StrVal = sub {
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my $pack = ref $_[0];
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# Perl's overload mechanism uses the presence of a special
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# "method" named "((" or "()" to signal it is in effect.
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# This test seeks to see if it has been set up. "((" post-
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# dates overloading.pm, so we can skip it.
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return "$_[0]" unless _mycan($pack, "()");
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# Even at this point, the invocant may not be blessed, so
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# check for that.
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return "$_[0]" if not _blessed($_[0]);
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bless $_[0], "Carp";
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my $str = "$_[0]";
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bless $_[0], $pack;
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$pack . substr $str, index $str, "=";
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}
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}
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}
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our $VERSION = '1.54';
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$VERSION =~ tr/_//d;
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our $MaxEvalLen = 0;
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our $Verbose = 0;
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our $CarpLevel = 0;
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our $MaxArgLen = 64; # How much of each argument to print. 0 = all.
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our $MaxArgNums = 8; # How many arguments to print. 0 = all.
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our $RefArgFormatter = undef; # allow caller to format reference arguments
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require Exporter;
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our @ISA = ('Exporter');
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our @EXPORT = qw(confess croak carp);
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our @EXPORT_OK = qw(cluck verbose longmess shortmess);
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our @EXPORT_FAIL = qw(verbose); # hook to enable verbose mode
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# The members of %Internal are packages that are internal to perl.
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# Carp will not report errors from within these packages if it
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# can. The members of %CarpInternal are internal to Perl's warning
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# system. Carp will not report errors from within these packages
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# either, and will not report calls *to* these packages for carp and
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# croak. They replace $CarpLevel, which is deprecated. The
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# $Max(EvalLen|(Arg(Len|Nums)) variables are used to specify how the eval
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# text and function arguments should be formatted when printed.
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our %CarpInternal;
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our %Internal;
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# disable these by default, so they can live w/o require Carp
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$CarpInternal{Carp}++;
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$CarpInternal{warnings}++;
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$Internal{Exporter}++;
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$Internal{'Exporter::Heavy'}++;
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# if the caller specifies verbose usage ("perl -MCarp=verbose script.pl")
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# then the following method will be called by the Exporter which knows
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# to do this thanks to @EXPORT_FAIL, above. $_[1] will contain the word
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# 'verbose'.
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sub export_fail { shift; $Verbose = shift if $_[0] eq 'verbose'; @_ }
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sub _cgc {
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no strict 'refs';
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return \&{"CORE::GLOBAL::caller"} if defined &{"CORE::GLOBAL::caller"};
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return;
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}
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sub longmess {
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local($!, $^E);
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# Icky backwards compatibility wrapper. :-(
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#
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# The story is that the original implementation hard-coded the
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# number of call levels to go back, so calls to longmess were off
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# by one. Other code began calling longmess and expecting this
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# behaviour, so the replacement has to emulate that behaviour.
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my $cgc = _cgc();
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my $call_pack = $cgc ? $cgc->() : caller();
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if ( $Internal{$call_pack} or $CarpInternal{$call_pack} ) {
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return longmess_heavy(@_);
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}
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else {
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local $CarpLevel = $CarpLevel + 1;
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return longmess_heavy(@_);
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}
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}
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our @CARP_NOT;
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sub shortmess {
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local($!, $^E);
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my $cgc = _cgc();
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# Icky backwards compatibility wrapper. :-(
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local @CARP_NOT = scalar( $cgc ? $cgc->() : caller() );
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shortmess_heavy(@_);
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}
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sub croak { die shortmess @_ }
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sub confess { die longmess @_ }
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sub carp { warn shortmess @_ }
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sub cluck { warn longmess @_ }
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BEGIN {
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if("$]" >= 5.015002 || ("$]" >= 5.014002 && "$]" < 5.015) ||
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("$]" >= 5.012005 && "$]" < 5.013)) {
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*CALLER_OVERRIDE_CHECK_OK = sub () { 1 };
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} else {
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*CALLER_OVERRIDE_CHECK_OK = sub () { 0 };
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}
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}
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sub caller_info {
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my $i = shift(@_) + 1;
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my %call_info;
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my $cgc = _cgc();
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{
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# Some things override caller() but forget to implement the
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# @DB::args part of it, which we need. We check for this by
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# pre-populating @DB::args with a sentinel which no-one else
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# has the address of, so that we can detect whether @DB::args
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# has been properly populated. However, on earlier versions
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# of perl this check tickles a bug in CORE::caller() which
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# leaks memory. So we only check on fixed perls.
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@DB::args = \$i if CALLER_OVERRIDE_CHECK_OK;
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package DB;
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@call_info{
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qw(pack file line sub has_args wantarray evaltext is_require) }
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= $cgc ? $cgc->($i) : caller($i);
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}
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unless ( defined $call_info{file} ) {
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return ();
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}
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my $sub_name = Carp::get_subname( \%call_info );
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if ( $call_info{has_args} ) {
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# Guard our serialization of the stack from stack refcounting bugs
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# NOTE this is NOT a complete solution, we cannot 100% guard against
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# these bugs. However in many cases Perl *is* capable of detecting
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# them and throws an error when it does. Unfortunately serializing
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# the arguments on the stack is a perfect way of finding these bugs,
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# even when they would not affect normal program flow that did not
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# poke around inside the stack. Inside of Carp.pm it makes little
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# sense reporting these bugs, as Carp's job is to report the callers
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# errors, not the ones it might happen to tickle while doing so.
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# See: https://rt.perl.org/Public/Bug/Display.html?id=131046
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# and: https://rt.perl.org/Public/Bug/Display.html?id=52610
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# for more details and discussion. - Yves
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my @args = map {
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my $arg;
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local $@= $@;
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eval {
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$arg = $_;
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1;
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} or do {
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$arg = '** argument not available anymore **';
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};
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$arg;
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} @DB::args;
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if (CALLER_OVERRIDE_CHECK_OK && @args == 1
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&& ref $args[0] eq ref \$i
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&& $args[0] == \$i ) {
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@args = (); # Don't let anyone see the address of $i
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local $@;
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my $where = eval {
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my $func = $cgc or return '';
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my $gv =
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(_fetch_sub B => 'svref_2object' or return '')
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->($func)->GV;
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my $package = $gv->STASH->NAME;
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my $subname = $gv->NAME;
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return unless defined $package && defined $subname;
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# returning CORE::GLOBAL::caller isn't useful for tracing the cause:
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return if $package eq 'CORE::GLOBAL' && $subname eq 'caller';
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" in &${package}::$subname";
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} || '';
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@args
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= "** Incomplete caller override detected$where; \@DB::args were not set **";
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}
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else {
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my $overflow;
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if ( $MaxArgNums and @args > $MaxArgNums )
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{ # More than we want to show?
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$#args = $MaxArgNums - 1;
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$overflow = 1;
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}
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@args = map { Carp::format_arg($_) } @args;
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if ($overflow) {
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push @args, '...';
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}
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}
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# Push the args onto the subroutine
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$sub_name .= '(' . join( ', ', @args ) . ')';
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}
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$call_info{sub_name} = $sub_name;
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return wantarray() ? %call_info : \%call_info;
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}
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# Transform an argument to a function into a string.
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our $in_recurse;
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sub format_arg {
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my $arg = shift;
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if ( my $pack= ref($arg) ) {
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# legitimate, let's not leak it.
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if (!$in_recurse && _maybe_isa( $arg, 'UNIVERSAL' ) &&
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do {
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local $@;
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local $in_recurse = 1;
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local $SIG{__DIE__} = sub{};
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eval {$arg->can('CARP_TRACE') }
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})
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{
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return $arg->CARP_TRACE();
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}
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elsif (!$in_recurse &&
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defined($RefArgFormatter) &&
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do {
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local $@;
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local $in_recurse = 1;
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local $SIG{__DIE__} = sub{};
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eval {$arg = $RefArgFormatter->($arg); 1}
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})
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{
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return $arg;
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}
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else
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{
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# Argument may be blessed into a class with overloading, and so
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# might have an overloaded stringification. We don't want to
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# risk getting the overloaded stringification, so we need to
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# use _StrVal, our overload::StrVal()-equivalent.
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return _StrVal $arg;
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}
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}
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return "undef" if !defined($arg);
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downgrade($arg, 1);
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return $arg if !(UTF8_REGEXP_PROBLEM && is_utf8($arg)) &&
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$arg =~ /\A-?[0-9]+(?:\.[0-9]*)?(?:[eE][-+]?[0-9]+)?\z/;
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my $suffix = "";
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if ( 2 < $MaxArgLen and $MaxArgLen < length($arg) ) {
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substr ( $arg, $MaxArgLen - 3 ) = "";
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$suffix = "...";
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}
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if(UTF8_REGEXP_PROBLEM && is_utf8($arg)) {
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for(my $i = length($arg); $i--; ) {
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my $c = substr($arg, $i, 1);
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my $x = substr($arg, 0, 0); # work around bug on Perl 5.8.{1,2}
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if($c eq "\"" || $c eq "\\" || $c eq "\$" || $c eq "\@") {
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substr $arg, $i, 0, "\\";
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next;
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}
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my $o = ord($c);
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substr $arg, $i, 1, sprintf("\\x{%x}", $o)
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unless is_safe_printable_codepoint($o);
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}
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} else {
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$arg =~ s/([\"\\\$\@])/\\$1/g;
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# This is all the ASCII printables spelled-out. It is portable to all
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# Perl versions and platforms (such as EBCDIC). There are other more
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# compact ways to do this, but may not work everywhere every version.
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$arg =~ s/([^ !"#\$\%\&'()*+,\-.\/0123456789:;<=>?\@ABCDEFGHIJKLMNOPQRSTUVWXYZ\[\\\]^_`abcdefghijklmnopqrstuvwxyz\{|}~])/sprintf("\\x{%x}",ord($1))/eg;
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}
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downgrade($arg, 1);
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return "\"".$arg."\"".$suffix;
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}
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|
|
sub Regexp::CARP_TRACE {
|
|
my $arg = "$_[0]";
|
|
downgrade($arg, 1);
|
|
if(UTF8_REGEXP_PROBLEM && is_utf8($arg)) {
|
|
for(my $i = length($arg); $i--; ) {
|
|
my $o = ord(substr($arg, $i, 1));
|
|
my $x = substr($arg, 0, 0); # work around bug on Perl 5.8.{1,2}
|
|
substr $arg, $i, 1, sprintf("\\x{%x}", $o)
|
|
unless is_safe_printable_codepoint($o);
|
|
}
|
|
} else {
|
|
# See comment in format_arg() about this same regex.
|
|
$arg =~ s/([^ !"#\$\%\&'()*+,\-.\/0123456789:;<=>?\@ABCDEFGHIJKLMNOPQRSTUVWXYZ\[\\\]^_`abcdefghijklmnopqrstuvwxyz\{|}~])/sprintf("\\x{%x}",ord($1))/eg;
|
|
}
|
|
downgrade($arg, 1);
|
|
my $suffix = "";
|
|
if($arg =~ /\A\(\?\^?([a-z]*)(?:-[a-z]*)?:(.*)\)\z/s) {
|
|
($suffix, $arg) = ($1, $2);
|
|
}
|
|
if ( 2 < $MaxArgLen and $MaxArgLen < length($arg) ) {
|
|
substr ( $arg, $MaxArgLen - 3 ) = "";
|
|
$suffix = "...".$suffix;
|
|
}
|
|
return "qr($arg)$suffix";
|
|
}
|
|
|
|
# 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 ) . "'";
|
|
}
|
|
}
|
|
|
|
# this can happen on older perls when the sub (or the stash containing it)
|
|
# has been deleted
|
|
if ( !defined( $info->{sub} ) ) {
|
|
return '__ANON__::__ANON__';
|
|
}
|
|
|
|
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 $cgc = _cgc();
|
|
my @caller = $cgc ? $cgc->($i) : caller($i);
|
|
my $pkg = $caller[0];
|
|
unless ( defined($pkg) ) {
|
|
|
|
# This *shouldn't* happen.
|
|
if (%Internal) {
|
|
local %Internal;
|
|
$i = long_error_loc();
|
|
last;
|
|
}
|
|
elsif (defined $caller[2]) {
|
|
# this can happen when the stash has been deleted
|
|
# in that case, just assume that it's a reasonable place to
|
|
# stop (the file and line data will still be intact in any
|
|
# case) - the only issue is that we can't detect if the
|
|
# deleted package was internal (so don't do that then)
|
|
# -doy
|
|
redo unless 0 > --$lvl;
|
|
last;
|
|
}
|
|
else {
|
|
return 2;
|
|
}
|
|
}
|
|
redo if $CarpInternal{$pkg};
|
|
redo unless 0 > --$lvl;
|
|
redo if $Internal{$pkg};
|
|
}
|
|
return $i - 1;
|
|
}
|
|
|
|
sub longmess_heavy {
|
|
if ( ref( $_[0] ) ) { # don't break references as exceptions
|
|
return wantarray ? @_ : $_[0];
|
|
}
|
|
my $i = long_error_loc();
|
|
return ret_backtrace( $i, @_ );
|
|
}
|
|
|
|
BEGIN {
|
|
if("$]" >= 5.017004) {
|
|
# The LAST_FH constant is a reference to the variable.
|
|
$Carp::{LAST_FH} = \eval '\${^LAST_FH}';
|
|
} else {
|
|
eval '*LAST_FH = sub () { 0 }';
|
|
}
|
|
}
|
|
|
|
# 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";
|
|
if( $. ) {
|
|
# Use ${^LAST_FH} if available.
|
|
if (LAST_FH) {
|
|
if (${+LAST_FH}) {
|
|
$mess .= sprintf ", <%s> %s %d",
|
|
*${+LAST_FH}{NAME},
|
|
($/ eq "\n" ? "line" : "chunk"), $.
|
|
}
|
|
}
|
|
else {
|
|
local $@ = '';
|
|
local $SIG{__DIE__};
|
|
eval {
|
|
CORE::die;
|
|
};
|
|
if($@ =~ /^Died at .*(, <.*?> (?:line|chunk) \d+).$/ ) {
|
|
$mess .= $1;
|
|
}
|
|
}
|
|
}
|
|
$mess .= "\.\n";
|
|
|
|
while ( my %i = caller_info( ++$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 $cgc = _cgc();
|
|
my $called = $cgc ? $cgc->($i) : caller($i);
|
|
$i++;
|
|
my $caller = $cgc ? $cgc->($i) : caller($i);
|
|
|
|
if (!defined($caller)) {
|
|
my @caller = $cgc ? $cgc->($i) : caller($i);
|
|
if (@caller) {
|
|
# if there's no package but there is other caller info, then
|
|
# the package has been deleted - treat this as a valid package
|
|
# in this case
|
|
redo if defined($called) && $CarpInternal{$called};
|
|
redo unless 0 > --$lvl;
|
|
last;
|
|
}
|
|
else {
|
|
return 0;
|
|
}
|
|
}
|
|
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';
|
|
my $stash = \%{"$class\::"};
|
|
for my $var (qw/ CARP_NOT ISA /) {
|
|
# Don't try using the variable until we know it exists,
|
|
# to avoid polluting the caller's namespace.
|
|
if ( $stash->{$var} && ref \$stash->{$var} eq 'GLOB'
|
|
&& *{$stash->{$var}}{ARRAY} && @{$stash->{$var}} ) {
|
|
return @{$stash->{$var}}
|
|
}
|
|
}
|
|
return;
|
|
}
|
|
|
|
if(!defined($warnings::VERSION) ||
|
|
do { no warnings "numeric"; $warnings::VERSION < 1.03 }) {
|
|
# Very old versions of warnings.pm import from Carp. This can go
|
|
# wrong due to the circular dependency. If Carp is invoked before
|
|
# warnings, then Carp starts by loading warnings, then warnings
|
|
# tries to import from Carp, and gets nothing because Carp is in
|
|
# the process of loading and hasn't defined its import method yet.
|
|
# So we work around that by manually exporting to warnings here.
|
|
no strict "refs";
|
|
*{"warnings::$_"} = \&$_ foreach @EXPORT;
|
|
}
|
|
|
|
1;
|
|
|
|
__END__
|
|
|
|
=head1 NAME
|
|
|
|
Carp - alternative warn and die for modules
|
|
|
|
=head1 SYNOPSIS
|
|
|
|
use Carp;
|
|
|
|
# warn user (from perspective of caller)
|
|
carp "string trimmed to 80 chars";
|
|
|
|
# die of errors (from perspective of caller)
|
|
croak "We're outta here!";
|
|
|
|
# die of errors with stack backtrace
|
|
confess "not implemented";
|
|
|
|
# cluck, longmess and shortmess not exported by default
|
|
use Carp qw(cluck longmess shortmess);
|
|
cluck "This is how we got here!"; # warn with stack backtrace
|
|
my $long_message = longmess( "message from cluck() or confess()" );
|
|
my $short_message = shortmess( "message from carp() or croak()" );
|
|
|
|
=head1 DESCRIPTION
|
|
|
|
The Carp routines are useful in your own modules because
|
|
they act like C<die()> or C<warn()>, but with a message which is more
|
|
likely to be useful to a user of your module. In the case of
|
|
C<cluck()> and C<confess()>, that context is a summary of every
|
|
call in the call-stack; C<longmess()> returns the contents of the error
|
|
message.
|
|
|
|
For a shorter message you can use C<carp()> or C<croak()> which report the
|
|
error as being from where your module was called. C<shortmess()> returns the
|
|
contents of this error message. There is no guarantee that that is where the
|
|
error was, but it is a good educated guess.
|
|
|
|
C<Carp> takes care not to clobber the status variables C<$!> and C<$^E>
|
|
in the course of assembling its error messages. This means that a
|
|
C<$SIG{__DIE__}> or C<$SIG{__WARN__}> handler can capture the error
|
|
information held in those variables, if it is required to augment the
|
|
error message, and if the code calling C<Carp> left useful values there.
|
|
Of course, C<Carp> can't guarantee the latter.
|
|
|
|
You can also alter the way the output and logic of C<Carp> works, by
|
|
changing some global variables in the C<Carp> namespace. See the
|
|
section on L</GLOBAL VARIABLES> below.
|
|
|
|
Here is a more complete description of how C<carp> and C<croak> work.
|
|
What they do is search the call-stack for a function call stack where
|
|
they have not been told that there shouldn't be an error. If every
|
|
call is marked safe, they give up and give a full stack backtrace
|
|
instead. In other words they presume that the first likely looking
|
|
potential suspect is guilty. Their rules for telling whether
|
|
a call shouldn't generate errors work as follows:
|
|
|
|
=over 4
|
|
|
|
=item 1.
|
|
|
|
Any call from a package to itself is safe.
|
|
|
|
=item 2.
|
|
|
|
Packages claim that there won't be errors on calls to or from
|
|
packages explicitly marked as safe by inclusion in C<@CARP_NOT>, or
|
|
(if that array is empty) C<@ISA>. The ability to override what
|
|
@ISA says is new in 5.8.
|
|
|
|
=item 3.
|
|
|
|
The trust in item 2 is transitive. If A trusts B, and B
|
|
trusts C, then A trusts C. So if you do not override C<@ISA>
|
|
with C<@CARP_NOT>, then this trust relationship is identical to,
|
|
"inherits from".
|
|
|
|
=item 4.
|
|
|
|
Any call from an internal Perl module is safe. (Nothing keeps
|
|
user modules from marking themselves as internal to Perl, but
|
|
this practice is discouraged.)
|
|
|
|
=item 5.
|
|
|
|
Any call to Perl's warning system (eg Carp itself) is safe.
|
|
(This rule is what keeps it from reporting the error at the
|
|
point where you call C<carp> or C<croak>.)
|
|
|
|
=item 6.
|
|
|
|
C<$Carp::CarpLevel> can be set to skip a fixed number of additional
|
|
call levels. Using this is not recommended because it is very
|
|
difficult to get it to behave correctly.
|
|
|
|
=back
|
|
|
|
=head2 Forcing a Stack Trace
|
|
|
|
As a debugging aid, you can force Carp to treat a croak as a confess
|
|
and a carp as a cluck across I<all> modules. In other words, force a
|
|
detailed stack trace to be given. This can be very helpful when trying
|
|
to understand why, or from where, a warning or error is being generated.
|
|
|
|
This feature is enabled by 'importing' the non-existent symbol
|
|
'verbose'. You would typically enable it by saying
|
|
|
|
perl -MCarp=verbose script.pl
|
|
|
|
or by including the string C<-MCarp=verbose> in the PERL5OPT
|
|
environment variable.
|
|
|
|
Alternately, you can set the global variable C<$Carp::Verbose> to true.
|
|
See the L</GLOBAL VARIABLES> section below.
|
|
|
|
=head2 Stack Trace formatting
|
|
|
|
At each stack level, the subroutine's name is displayed along with
|
|
its parameters. For simple scalars, this is sufficient. For complex
|
|
data types, such as objects and other references, this can simply
|
|
display C<'HASH(0x1ab36d8)'>.
|
|
|
|
Carp gives two ways to control this.
|
|
|
|
=over 4
|
|
|
|
=item 1.
|
|
|
|
For objects, a method, C<CARP_TRACE>, will be called, if it exists. If
|
|
this method doesn't exist, or it recurses into C<Carp>, or it otherwise
|
|
throws an exception, this is skipped, and Carp moves on to the next option,
|
|
otherwise checking stops and the string returned is used. It is recommended
|
|
that the object's type is part of the string to make debugging easier.
|
|
|
|
=item 2.
|
|
|
|
For any type of reference, C<$Carp::RefArgFormatter> is checked (see below).
|
|
This variable is expected to be a code reference, and the current parameter
|
|
is passed in. If this function doesn't exist (the variable is undef), or
|
|
it recurses into C<Carp>, or it otherwise throws an exception, this is
|
|
skipped, and Carp moves on to the next option, otherwise checking stops
|
|
and the string returned is used.
|
|
|
|
=item 3.
|
|
|
|
Otherwise, if neither C<CARP_TRACE> nor C<$Carp::RefArgFormatter> is
|
|
available, stringify the value ignoring any overloading.
|
|
|
|
=back
|
|
|
|
=head1 GLOBAL VARIABLES
|
|
|
|
=head2 $Carp::MaxEvalLen
|
|
|
|
This variable determines how many characters of a string-eval are to
|
|
be shown in the output. Use a value of C<0> to show all text.
|
|
|
|
Defaults to C<0>.
|
|
|
|
=head2 $Carp::MaxArgLen
|
|
|
|
This variable determines how many characters of each argument to a
|
|
function to print. Use a value of C<0> to show the full length of the
|
|
argument.
|
|
|
|
Defaults to C<64>.
|
|
|
|
=head2 $Carp::MaxArgNums
|
|
|
|
This variable determines how many arguments to each function to show.
|
|
Use a false value to show all arguments to a function call. To suppress all
|
|
arguments, use C<-1> or C<'0 but true'>.
|
|
|
|
Defaults to C<8>.
|
|
|
|
=head2 $Carp::Verbose
|
|
|
|
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::RefArgFormatter
|
|
|
|
This variable sets a general argument formatter to display references.
|
|
Plain scalars and objects that implement C<CARP_TRACE> will not go through
|
|
this formatter. Calling C<Carp> from within this function is not supported.
|
|
|
|
local $Carp::RefArgFormatter = sub {
|
|
require Data::Dumper;
|
|
Data::Dumper->Dump($_[0]); # not necessarily safe
|
|
};
|
|
|
|
=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>.
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|
|
|
=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__) }++;
|
|
# time passes...
|
|
sub foo { ... or confess("whatever") };
|
|
|
|
would give a full stack backtrace starting from the first caller
|
|
outside of __PACKAGE__. (Unless that package was also internal to
|
|
Perl.)
|
|
|
|
=head2 %Carp::CarpInternal
|
|
|
|
This says which packages are internal to Perl's warning system. For
|
|
generating a full stack backtrace this is the same as being internal
|
|
to Perl, the stack backtrace will not start inside packages that are
|
|
listed in C<%Carp::CarpInternal>. But it is slightly different for
|
|
the summary message generated by C<carp> or C<croak>. There errors
|
|
will not be reported on any lines that are calling packages in
|
|
C<%Carp::CarpInternal>.
|
|
|
|
For example C<Carp> itself is listed in C<%Carp::CarpInternal>.
|
|
Therefore the full stack backtrace from C<confess> will not start
|
|
inside of C<Carp>, and the short message from calling C<croak> is
|
|
not placed on the line where C<croak> was called.
|
|
|
|
=head2 $Carp::CarpLevel
|
|
|
|
This variable determines how many additional call frames are to be
|
|
skipped that would not otherwise be when reporting where an error
|
|
occurred on a call to one of C<Carp>'s functions. It is fairly easy
|
|
to count these call frames on calls that generate a full stack
|
|
backtrace. However it is much harder to do this accounting for calls
|
|
that generate a short message. Usually people skip too many call
|
|
frames. If they are lucky they skip enough that C<Carp> goes all of
|
|
the way through the call stack, realizes that something is wrong, and
|
|
then generates a full stack backtrace. If they are unlucky then the
|
|
error is reported from somewhere misleading very high in the call
|
|
stack.
|
|
|
|
Therefore it is best to avoid C<$Carp::CarpLevel>. Instead use
|
|
C<@CARP_NOT>, C<%Carp::Internal> and C<%Carp::CarpInternal>.
|
|
|
|
Defaults to C<0>.
|
|
|
|
=head1 BUGS
|
|
|
|
The Carp routines don't handle exception objects currently.
|
|
If called with a first argument that is a reference, they simply
|
|
call die() or warn(), as appropriate.
|
|
|
|
=head1 SEE ALSO
|
|
|
|
L<Carp::Always>,
|
|
L<Carp::Clan>
|
|
|
|
=head1 CONTRIBUTING
|
|
|
|
L<Carp> is maintained by the perl 5 porters as part of the core perl 5
|
|
version control repository. Please see the L<perlhack> perldoc for how to
|
|
submit patches and contribute to it.
|
|
|
|
=head1 AUTHOR
|
|
|
|
The Carp module first appeared in Larry Wall's perl 5.000 distribution.
|
|
Since then it has been modified by several of the perl 5 porters.
|
|
Andrew Main (Zefram) <zefram@fysh.org> divested Carp into an independent
|
|
distribution.
|
|
|
|
=head1 COPYRIGHT
|
|
|
|
Copyright (C) 1994-2013 Larry Wall
|
|
|
|
Copyright (C) 2011, 2012, 2013 Andrew Main (Zefram) <zefram@fysh.org>
|
|
|
|
=head1 LICENSE
|
|
|
|
This module is free software; you can redistribute it and/or modify it
|
|
under the same terms as Perl itself.
|