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authorNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
committerNorbert Preining <norbert@preining.info>2019-09-02 13:46:59 +0900
commite0c6872cf40896c7be36b11dcc744620f10adf1d (patch)
tree60335e10d2f4354b0674ec22d7b53f0f8abee672 /systems/texlive/tlnet/tlpkg/tlperl/lib/Fatal.pm
Initial commit
Diffstat (limited to 'systems/texlive/tlnet/tlpkg/tlperl/lib/Fatal.pm')
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diff --git a/systems/texlive/tlnet/tlpkg/tlperl/lib/Fatal.pm b/systems/texlive/tlnet/tlpkg/tlperl/lib/Fatal.pm
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+++ b/systems/texlive/tlnet/tlpkg/tlperl/lib/Fatal.pm
@@ -0,0 +1,1813 @@
+package Fatal;
+
+# ABSTRACT: Replace functions with equivalents which succeed or die
+
+use 5.008; # 5.8.x needed for autodie
+use Carp;
+use strict;
+use warnings;
+use Tie::RefHash; # To cache subroutine refs
+use Config;
+use Scalar::Util qw(set_prototype);
+
+use autodie::Util qw(
+ fill_protos
+ install_subs
+ make_core_trampoline
+ on_end_of_compile_scope
+);
+
+use constant PERL510 => ( $] >= 5.010 );
+
+use constant LEXICAL_TAG => q{:lexical};
+use constant VOID_TAG => q{:void};
+use constant INSIST_TAG => q{!};
+
+# Keys for %Cached_fatalised_sub (used in 3rd level)
+use constant CACHE_AUTODIE_LEAK_GUARD => 0;
+use constant CACHE_FATAL_WRAPPER => 1;
+use constant CACHE_FATAL_VOID => 2;
+
+
+use constant ERROR_NOARGS => 'Cannot use lexical %s with no arguments';
+use constant ERROR_VOID_LEX => VOID_TAG.' cannot be used with lexical scope';
+use constant ERROR_LEX_FIRST => LEXICAL_TAG.' must be used as first argument';
+use constant ERROR_NO_LEX => "no %s can only start with ".LEXICAL_TAG;
+use constant ERROR_BADNAME => "Bad subroutine name for %s: %s";
+use constant ERROR_NOTSUB => "%s is not a Perl subroutine";
+use constant ERROR_NOT_BUILT => "%s is neither a builtin, nor a Perl subroutine";
+use constant ERROR_NOHINTS => "No user hints defined for %s";
+
+use constant ERROR_CANT_OVERRIDE => "Cannot make the non-overridable builtin %s fatal";
+
+use constant ERROR_NO_IPC_SYS_SIMPLE => "IPC::System::Simple required for Fatalised/autodying system()";
+
+use constant ERROR_IPC_SYS_SIMPLE_OLD => "IPC::System::Simple version %f required for Fatalised/autodying system(). We only have version %f";
+
+use constant ERROR_AUTODIE_CONFLICT => q{"no autodie '%s'" is not allowed while "use Fatal '%s'" is in effect};
+
+use constant ERROR_FATAL_CONFLICT => q{"use Fatal '%s'" is not allowed while "no autodie '%s'" is in effect};
+
+use constant ERROR_58_HINTS => q{Non-subroutine %s hints for %s are not supported under Perl 5.8.x};
+
+# Older versions of IPC::System::Simple don't support all the
+# features we need.
+
+use constant MIN_IPC_SYS_SIMPLE_VER => 0.12;
+
+our $VERSION = '2.29'; # VERSION: Generated by DZP::OurPkg::Version
+
+our $Debug ||= 0;
+
+# EWOULDBLOCK values for systems that don't supply their own.
+# Even though this is defined with our, that's to help our
+# test code. Please don't rely upon this variable existing in
+# the future.
+
+our %_EWOULDBLOCK = (
+ MSWin32 => 33,
+);
+
+$Carp::CarpInternal{'Fatal'} = 1;
+$Carp::CarpInternal{'autodie'} = 1;
+$Carp::CarpInternal{'autodie::exception'} = 1;
+
+# the linux parisc port has separate EAGAIN and EWOULDBLOCK,
+# and the kernel returns EAGAIN
+my $try_EAGAIN = ($^O eq 'linux' and $Config{archname} =~ /hppa|parisc/) ? 1 : 0;
+
+# We have some tags that can be passed in for use with import.
+# These are all assumed to be CORE::
+
+my %TAGS = (
+ ':io' => [qw(:dbm :file :filesys :ipc :socket
+ read seek sysread syswrite sysseek )],
+ ':dbm' => [qw(dbmopen dbmclose)],
+ ':file' => [qw(open close flock sysopen fcntl binmode
+ ioctl truncate)],
+ ':filesys' => [qw(opendir closedir chdir link unlink rename mkdir
+ symlink rmdir readlink chmod chown utime)],
+ ':ipc' => [qw(:msg :semaphore :shm pipe kill)],
+ ':msg' => [qw(msgctl msgget msgrcv msgsnd)],
+ ':threads' => [qw(fork)],
+ ':semaphore'=>[qw(semctl semget semop)],
+ ':shm' => [qw(shmctl shmget shmread)],
+ ':system' => [qw(system exec)],
+
+ # Can we use qw(getpeername getsockname)? What do they do on failure?
+ # TODO - Can socket return false?
+ ':socket' => [qw(accept bind connect getsockopt listen recv send
+ setsockopt shutdown socketpair)],
+
+ # Our defaults don't include system(), because it depends upon
+ # an optional module, and it breaks the exotic form.
+ #
+ # This *may* change in the future. I'd love IPC::System::Simple
+ # to be a dependency rather than a recommendation, and hence for
+ # system() to be autodying by default.
+
+ ':default' => [qw(:io :threads)],
+
+ # Everything in v2.07 and before. This was :default less chmod and chown
+ ':v207' => [qw(:threads :dbm :socket read seek sysread
+ syswrite sysseek open close flock sysopen fcntl fileno
+ binmode ioctl truncate opendir closedir chdir link unlink
+ rename mkdir symlink rmdir readlink umask
+ :msg :semaphore :shm pipe)],
+
+ # Chmod was added in 2.13
+ ':v213' => [qw(:v207 chmod)],
+
+ # chown, utime, kill were added in 2.14
+ ':v214' => [qw(:v213 chown utime kill)],
+
+ # umask was removed in 2.26
+ ':v225' => [qw(:io :threads umask fileno)],
+
+ # Version specific tags. These allow someone to specify
+ # use autodie qw(:1.994) and know exactly what they'll get.
+
+ ':1.994' => [qw(:v207)],
+ ':1.995' => [qw(:v207)],
+ ':1.996' => [qw(:v207)],
+ ':1.997' => [qw(:v207)],
+ ':1.998' => [qw(:v207)],
+ ':1.999' => [qw(:v207)],
+ ':1.999_01' => [qw(:v207)],
+ ':2.00' => [qw(:v207)],
+ ':2.01' => [qw(:v207)],
+ ':2.02' => [qw(:v207)],
+ ':2.03' => [qw(:v207)],
+ ':2.04' => [qw(:v207)],
+ ':2.05' => [qw(:v207)],
+ ':2.06' => [qw(:v207)],
+ ':2.06_01' => [qw(:v207)],
+ ':2.07' => [qw(:v207)], # Last release without chmod
+ ':2.08' => [qw(:v213)],
+ ':2.09' => [qw(:v213)],
+ ':2.10' => [qw(:v213)],
+ ':2.11' => [qw(:v213)],
+ ':2.12' => [qw(:v213)],
+ ':2.13' => [qw(:v213)], # Last release without chown
+ ':2.14' => [qw(:v225)],
+ ':2.15' => [qw(:v225)],
+ ':2.16' => [qw(:v225)],
+ ':2.17' => [qw(:v225)],
+ ':2.18' => [qw(:v225)],
+ ':2.19' => [qw(:v225)],
+ ':2.20' => [qw(:v225)],
+ ':2.21' => [qw(:v225)],
+ ':2.22' => [qw(:v225)],
+ ':2.23' => [qw(:v225)],
+ ':2.24' => [qw(:v225)],
+ ':2.25' => [qw(:v225)],
+ ':2.26' => [qw(:default)],
+ ':2.27' => [qw(:default)],
+ ':2.28' => [qw(:default)],
+ ':2.29' => [qw(:default)],
+);
+
+
+{
+ # Expand :all immediately by expanding and flattening all tags.
+ # _expand_tag is not really optimised for expanding the ":all"
+ # case (i.e. keys %TAGS, or values %TAGS for that matter), so we
+ # just do it here.
+ #
+ # NB: The %tag_cache/_expand_tag relies on $TAGS{':all'} being
+ # pre-expanded.
+ my %seen;
+ my @all = grep {
+ !/^:/ && !$seen{$_}++
+ } map { @{$_} } values %TAGS;
+ $TAGS{':all'} = \@all;
+}
+
+# This hash contains subroutines for which we should
+# subroutine() // die() rather than subroutine() || die()
+
+my %Use_defined_or;
+
+# CORE::open returns undef on failure. It can legitimately return
+# 0 on success, eg: open(my $fh, '-|') || exec(...);
+
+@Use_defined_or{qw(
+ CORE::fork
+ CORE::recv
+ CORE::send
+ CORE::open
+ CORE::fileno
+ CORE::read
+ CORE::readlink
+ CORE::sysread
+ CORE::syswrite
+ CORE::sysseek
+ CORE::umask
+)} = ();
+
+# Some functions can return true because they changed *some* things, but
+# not all of them. This is a list of offending functions, and how many
+# items to subtract from @_ to determine the "success" value they return.
+
+my %Returns_num_things_changed = (
+ 'CORE::chmod' => 1,
+ 'CORE::chown' => 2,
+ 'CORE::kill' => 1, # TODO: Could this return anything on negative args?
+ 'CORE::unlink' => 0,
+ 'CORE::utime' => 2,
+);
+
+# Optional actions to take on the return value before returning it.
+
+my %Retval_action = (
+ "CORE::open" => q{
+
+ # apply the open pragma from our caller
+ if( defined $retval && !( @_ >= 3 && $_[1] =~ /:/ )) {
+ # Get the caller's hint hash
+ my $hints = (caller 0)[10];
+
+ # Decide if we're reading or writing and apply the appropriate encoding
+ # These keys are undocumented.
+ # Match what PerlIO_context_layers() does. Read gets the read layer,
+ # everything else gets the write layer.
+ my $encoding = $_[1] =~ /^\+?>/ ? $hints->{"open>"} : $hints->{"open<"};
+
+ # Apply the encoding, if any.
+ if( $encoding ) {
+ binmode $_[0], $encoding;
+ }
+ }
+
+},
+ "CORE::sysopen" => q{
+
+ # apply the open pragma from our caller
+ if( defined $retval ) {
+ # Get the caller's hint hash
+ my $hints = (caller 0)[10];
+
+ require Fcntl;
+
+ # Decide if we're reading or writing and apply the appropriate encoding.
+ # Match what PerlIO_context_layers() does. Read gets the read layer,
+ # everything else gets the write layer.
+ my $open_read_only = !($_[2] ^ Fcntl::O_RDONLY());
+ my $encoding = $open_read_only ? $hints->{"open<"} : $hints->{"open>"};
+
+ # Apply the encoding, if any.
+ if( $encoding ) {
+ binmode $_[0], $encoding;
+ }
+ }
+
+},
+);
+
+my %reusable_builtins;
+
+# "Wait!" I hear you cry, "truncate() and chdir() are not reuseable! They can
+# take file and directory handles, which are package depedent."
+#
+# You would be correct, except that prototype() returns signatures which don't
+# allow for passing of globs, and nobody's complained about that. You can
+# still use \*FILEHANDLE, but that results in a reference coming through,
+# and it's already pointing to the filehandle in the caller's packge, so
+# it's all okay.
+
+@reusable_builtins{qw(
+ CORE::fork
+ CORE::kill
+ CORE::truncate
+ CORE::chdir
+ CORE::link
+ CORE::unlink
+ CORE::rename
+ CORE::mkdir
+ CORE::symlink
+ CORE::rmdir
+ CORE::readlink
+ CORE::umask
+ CORE::chmod
+ CORE::chown
+ CORE::utime
+ CORE::msgctl
+ CORE::msgget
+ CORE::msgrcv
+ CORE::msgsnd
+ CORE::semctl
+ CORE::semget
+ CORE::semop
+ CORE::shmctl
+ CORE::shmget
+ CORE::shmread
+ CORE::exec
+ CORE::system
+)} = ();
+
+# Cached_fatalised_sub caches the various versions of our
+# fatalised subs as they're produced. This means we don't
+# have to build our own replacement of CORE::open and friends
+# for every single package that wants to use them.
+
+my %Cached_fatalised_sub = ();
+
+# Every time we're called with package scope, we record the subroutine
+# (including package or CORE::) in %Package_Fatal. This allows us
+# to detect illegal combinations of autodie and Fatal, and makes sure
+# we don't accidently make a Fatal function autodying (which isn't
+# very useful).
+
+my %Package_Fatal = ();
+
+# The first time we're called with a user-sub, we cache it here.
+# In the case of a "no autodie ..." we put back the cached copy.
+
+my %Original_user_sub = ();
+
+# Is_fatalised_sub simply records a big map of fatalised subroutine
+# refs. It means we can avoid repeating work, or fatalising something
+# we've already processed.
+
+my %Is_fatalised_sub = ();
+tie %Is_fatalised_sub, 'Tie::RefHash';
+
+# Our trampoline cache allows us to cache trampolines which are used to
+# bounce leaked wrapped core subroutines to their actual core counterparts.
+
+my %Trampoline_cache;
+
+# A cache mapping "CORE::<name>" to their prototype. Turns out that if
+# you "use autodie;" enough times, this pays off.
+my %CORE_prototype_cache;
+
+# We use our package in a few hash-keys. Having it in a scalar is
+# convenient. The "guard $PACKAGE" string is used as a key when
+# setting up lexical guards.
+
+my $PACKAGE = __PACKAGE__;
+my $NO_PACKAGE = "no $PACKAGE"; # Used to detect 'no autodie'
+
+# Here's where all the magic happens when someone write 'use Fatal'
+# or 'use autodie'.
+
+sub import {
+ my $class = shift(@_);
+ my @original_args = @_;
+ my $void = 0;
+ my $lexical = 0;
+ my $insist_hints = 0;
+
+ my ($pkg, $filename) = caller();
+
+ @_ or return; # 'use Fatal' is a no-op.
+
+ # If we see the :lexical flag, then _all_ arguments are
+ # changed lexically
+
+ if ($_[0] eq LEXICAL_TAG) {
+ $lexical = 1;
+ shift @_;
+
+ # It is currently an implementation detail that autodie is
+ # implemented as "use Fatal qw(:lexical ...)". For backwards
+ # compatibility, we allow it - but not without a warning.
+ # NB: Optimise for autodie as it is quite possibly the most
+ # freq. consumer of this case.
+ if ($class ne 'autodie' and not $class->isa('autodie')) {
+ if ($class eq 'Fatal') {
+ warnings::warnif(
+ 'deprecated',
+ '[deprecated] The "use Fatal qw(:lexical ...)" '
+ . 'should be replaced by "use autodie qw(...)". '
+ . 'Seen' # warnif appends " at <...>"
+ );
+ } else {
+ warnings::warnif(
+ 'deprecated',
+ "[deprecated] The class/Package $class is a "
+ . 'subclass of Fatal and used the :lexical. '
+ . 'If $class provides lexical error checking '
+ . 'it should extend autodie instead of using :lexical. '
+ . 'Seen' # warnif appends " at <...>"
+ );
+ }
+ # "Promote" the call to autodie from here on. This is
+ # already mostly the case (e.g. use Fatal qw(:lexical ...)
+ # would throw autodie::exceptions on error rather than the
+ # Fatal errors.
+ $class = 'autodie';
+ # This requires that autodie is in fact loaded; otherwise
+ # the "$class->X()" method calls below will explode.
+ require autodie;
+ # TODO, when autodie and Fatal are cleanly separated, we
+ # should go a "goto &autodie::import" here instead.
+ }
+
+ # If we see no arguments and :lexical, we assume they
+ # wanted ':default'.
+
+ if (@_ == 0) {
+ push(@_, ':default');
+ }
+
+ # Don't allow :lexical with :void, it's needlessly confusing.
+ if ( grep { $_ eq VOID_TAG } @_ ) {
+ croak(ERROR_VOID_LEX);
+ }
+ }
+
+ if ( grep { $_ eq LEXICAL_TAG } @_ ) {
+ # If we see the lexical tag as the non-first argument, complain.
+ croak(ERROR_LEX_FIRST);
+ }
+
+ my @fatalise_these = @_;
+
+ # These subs will get unloaded at the end of lexical scope.
+ my %unload_later;
+ # These subs are to be installed into callers namespace.
+ my %install_subs;
+
+ # Use _translate_import_args to expand tags for us. It will
+ # pass-through unknown tags (i.e. we have to manually handle
+ # VOID_TAG).
+ #
+ # NB: _translate_import_args re-orders everything for us, so
+ # we don't have to worry about stuff like:
+ #
+ # :default :void :io
+ #
+ # That will (correctly) translated into
+ #
+ # expand(:defaults-without-io) :void :io
+ #
+ # by _translate_import_args.
+ for my $func ($class->_translate_import_args(@fatalise_these)) {
+
+ if ($func eq VOID_TAG) {
+
+ # When we see :void, set the void flag.
+ $void = 1;
+
+ } elsif ($func eq INSIST_TAG) {
+
+ $insist_hints = 1;
+
+ } else {
+
+ # Otherwise, fatalise it.
+
+ # Check to see if there's an insist flag at the front.
+ # If so, remove it, and insist we have hints for this sub.
+ my $insist_this = $insist_hints;
+
+ if (substr($func, 0, 1) eq '!') {
+ $func = substr($func, 1);
+ $insist_this = 1;
+ }
+
+ # We're going to make a subroutine fatalistic.
+ # However if we're being invoked with 'use Fatal qw(x)'
+ # and we've already been called with 'no autodie qw(x)'
+ # in the same scope, we consider this to be an error.
+ # Mixing Fatal and autodie effects was considered to be
+ # needlessly confusing on p5p.
+
+ my $sub = $func;
+ $sub = "${pkg}::$sub" unless $sub =~ /::/;
+
+ # If we're being called as Fatal, and we've previously
+ # had a 'no X' in scope for the subroutine, then complain
+ # bitterly.
+
+ if (! $lexical and $^H{$NO_PACKAGE}{$sub}) {
+ croak(sprintf(ERROR_FATAL_CONFLICT, $func, $func));
+ }
+
+ # We're not being used in a confusing way, so make
+ # the sub fatal. Note that _make_fatal returns the
+ # old (original) version of the sub, or undef for
+ # built-ins.
+
+ my $sub_ref = $class->_make_fatal(
+ $func, $pkg, $void, $lexical, $filename,
+ $insist_this, \%install_subs,
+ );
+
+ $Original_user_sub{$sub} ||= $sub_ref;
+
+ # If we're making lexical changes, we need to arrange
+ # for them to be cleaned at the end of our scope, so
+ # record them here.
+
+ $unload_later{$func} = $sub_ref if $lexical;
+ }
+ }
+
+ install_subs($pkg, \%install_subs);
+
+ if ($lexical) {
+
+ # Dark magic to have autodie work under 5.8
+ # Copied from namespace::clean, that copied it from
+ # autobox, that found it on an ancient scroll written
+ # in blood.
+
+ # This magic bit causes %^H to be lexically scoped.
+
+ $^H |= 0x020000;
+
+ # Our package guard gets invoked when we leave our lexical
+ # scope.
+
+ on_end_of_compile_scope(sub {
+ install_subs($pkg, \%unload_later);
+ });
+
+ # To allow others to determine when autodie was in scope,
+ # and with what arguments, we also set a %^H hint which
+ # is how we were called.
+
+ # This feature should be considered EXPERIMENTAL, and
+ # may change without notice. Please e-mail pjf@cpan.org
+ # if you're actually using it.
+
+ $^H{autodie} = "$PACKAGE @original_args";
+
+ }
+
+ return;
+
+}
+
+sub unimport {
+ my $class = shift;
+
+ # Calling "no Fatal" must start with ":lexical"
+ if ($_[0] ne LEXICAL_TAG) {
+ croak(sprintf(ERROR_NO_LEX,$class));
+ }
+
+ shift @_; # Remove :lexical
+
+ my $pkg = (caller)[0];
+
+ # If we've been called with arguments, then the developer
+ # has explicitly stated 'no autodie qw(blah)',
+ # in which case, we disable Fatalistic behaviour for 'blah'.
+
+ my @unimport_these = @_ ? @_ : ':all';
+ my (%uninstall_subs, %reinstall_subs);
+
+ for my $symbol ($class->_translate_import_args(@unimport_these)) {
+
+ my $sub = $symbol;
+ $sub = "${pkg}::$sub" unless $sub =~ /::/;
+
+ # If 'blah' was already enabled with Fatal (which has package
+ # scope) then, this is considered an error.
+
+ if (exists $Package_Fatal{$sub}) {
+ croak(sprintf(ERROR_AUTODIE_CONFLICT,$symbol,$symbol));
+ }
+
+ # Record 'no autodie qw($sub)' as being in effect.
+ # This is to catch conflicting semantics elsewhere
+ # (eg, mixing Fatal with no autodie)
+
+ $^H{$NO_PACKAGE}{$sub} = 1;
+ # Record the current sub to be reinstalled at end of scope
+ # and then restore the original (can be undef for "CORE::"
+ # subs)
+ $reinstall_subs{$symbol} = \&$sub;
+ $uninstall_subs{$symbol} = $Original_user_sub{$sub};
+
+ }
+
+ install_subs($pkg, \%uninstall_subs);
+ on_end_of_compile_scope(sub {
+ install_subs($pkg, \%reinstall_subs);
+ });
+
+ return;
+
+}
+
+sub _translate_import_args {
+ my ($class, @args) = @_;
+ my @result;
+ my %seen;
+
+ if (@args < 2) {
+ # Optimize for this case, as it is fairly common. (e.g. use
+ # autodie; or use autodie qw(:all); both trigger this).
+ return unless @args;
+
+ # Not a (known) tag, pass through.
+ return @args unless exists($TAGS{$args[0]});
+
+ # Strip "CORE::" from all elements in the list as import and
+ # unimport does not handle the "CORE::" prefix too well.
+ #
+ # NB: we use substr as it is faster than s/^CORE::// and
+ # it does not change the elements.
+ return map { substr($_, 6) } @{ $class->_expand_tag($args[0]) };
+ }
+
+ # We want to translate
+ #
+ # :default :void :io
+ #
+ # into (pseudo-ish):
+ #
+ # expanded(:threads) :void expanded(:io)
+ #
+ # We accomplish this by "reverse, expand + filter, reverse".
+ for my $a (reverse(@args)) {
+ if (exists $TAGS{$a}) {
+ my $expanded = $class->_expand_tag($a);
+ push(@result,
+ # Remove duplicates after ...
+ grep { !$seen{$_}++ }
+ # we have stripped CORE:: (see above)
+ map { substr($_, 6) }
+ # We take the elements in reverse order
+ # (as @result be reversed later).
+ reverse(@{$expanded}));
+ } else {
+ # pass through - no filtering here for tags.
+ #
+ # The reason for not filtering tags cases like:
+ #
+ # ":default :void :io :void :threads"
+ #
+ # As we have reversed args, we see this as:
+ #
+ # ":threads :void :io :void* :default*"
+ #
+ # (Entries marked with "*" will be filtered out completely). When
+ # reversed again, this will be:
+ #
+ # ":io :void :threads"
+ #
+ # But we would rather want it to be:
+ #
+ # ":void :io :threads" or ":void :io :void :threads"
+ #
+
+ my $letter = substr($a, 0, 1);
+ if ($letter ne ':' && $a ne INSIST_TAG) {
+ next if $seen{$a}++;
+ if ($letter eq '!' and $seen{substr($a, 1)}++) {
+ my $name = substr($a, 1);
+ # People are being silly and doing:
+ #
+ # use autodie qw(!a a);
+ #
+ # Enjoy this little O(n) clean up...
+ @result = grep { $_ ne $name } @result;
+ }
+ }
+ push @result, $a;
+ }
+ }
+ # Reverse the result to restore the input order
+ return reverse(@result);
+}
+
+
+# NB: Perl::Critic's dump-autodie-tag-contents depends upon this
+# continuing to work.
+
+{
+ # We assume that $TAGS{':all'} is pre-expanded and just fill it in
+ # from the beginning.
+ my %tag_cache = (
+ 'all' => [map { "CORE::$_" } @{$TAGS{':all'}}],
+ );
+
+ # Expand a given tag (e.g. ":default") into a listref containing
+ # all sub names covered by that tag. Each sub is returned as
+ # "CORE::<name>" (i.e. "CORE::open" rather than "open").
+ #
+ # NB: the listref must not be modified.
+ sub _expand_tag {
+ my ($class, $tag) = @_;
+
+ if (my $cached = $tag_cache{$tag}) {
+ return $cached;
+ }
+
+ if (not exists $TAGS{$tag}) {
+ croak "Invalid exception class $tag";
+ }
+
+ my @to_process = @{$TAGS{$tag}};
+
+ # If the tag is basically an alias of another tag (like e.g. ":2.11"),
+ # then just share the resulting reference with the original content (so
+ # we only pay for an extra reference for the alias memory-wise).
+ if (@to_process == 1 && substr($to_process[0], 0, 1) eq ':') {
+ # We could do this for "non-tags" as well, but that only occurs
+ # once at the time of writing (":threads" => ["fork"]), so
+ # probably not worth it.
+ my $expanded = $class->_expand_tag($to_process[0]);
+ $tag_cache{$tag} = $expanded;
+ return $expanded;
+ }
+
+ my %seen = ();
+ my @taglist = ();
+
+ for my $item (@to_process) {
+ # substr is more efficient than m/^:/ for stuff like this,
+ # at the price of being a bit more verbose/low-level.
+ if (substr($item, 0, 1) eq ':') {
+ # Use recursion here to ensure we expand a tag at most once.
+
+ my $expanded = $class->_expand_tag($item);
+ push @taglist, grep { !$seen{$_}++ } @{$expanded};
+ } else {
+ my $subname = "CORE::$item";
+ push @taglist, $subname
+ unless $seen{$subname}++;
+ }
+ }
+
+ $tag_cache{$tag} = \@taglist;
+
+ return \@taglist;
+
+ }
+
+}
+
+# This is a backwards compatible version of _write_invocation. It's
+# recommended you don't use it.
+
+sub write_invocation {
+ my ($core, $call, $name, $void, @args) = @_;
+
+ return Fatal->_write_invocation(
+ $core, $call, $name, $void,
+ 0, # Lexical flag
+ undef, # Sub, unused in legacy mode
+ undef, # Subref, unused in legacy mode.
+ @args
+ );
+}
+
+# This version of _write_invocation is used internally. It's not
+# recommended you call it from external code, as the interface WILL
+# change in the future.
+
+sub _write_invocation {
+
+ my ($class, $core, $call, $name, $void, $lexical, $sub, $sref, @argvs) = @_;
+
+ if (@argvs == 1) { # No optional arguments
+
+ my @argv = @{$argvs[0]};
+ shift @argv;
+
+ return $class->_one_invocation($core,$call,$name,$void,$sub,! $lexical, $sref, @argv);
+
+ } else {
+ my $else = "\t";
+ my (@out, @argv, $n);
+ while (@argvs) {
+ @argv = @{shift @argvs};
+ $n = shift @argv;
+
+ my $condition = "\@_ == $n";
+
+ if (@argv and $argv[-1] =~ /[#@]_/) {
+ # This argv ends with '@' in the prototype, so it matches
+ # any number of args >= the number of expressions in the
+ # argv.
+ $condition = "\@_ >= $n";
+ }
+
+ push @out, "${else}if ($condition) {\n";
+
+ $else = "\t} els";
+
+ push @out, $class->_one_invocation($core,$call,$name,$void,$sub,! $lexical, $sref, @argv);
+ }
+ push @out, qq[
+ }
+ die "Internal error: $name(\@_): Do not expect to get ", scalar(\@_), " arguments";
+ ];
+
+ return join '', @out;
+ }
+}
+
+
+# This is a slim interface to ensure backward compatibility with
+# anyone doing very foolish things with old versions of Fatal.
+
+sub one_invocation {
+ my ($core, $call, $name, $void, @argv) = @_;
+
+ return Fatal->_one_invocation(
+ $core, $call, $name, $void,
+ undef, # Sub. Unused in back-compat mode.
+ 1, # Back-compat flag
+ undef, # Subref, unused in back-compat mode.
+ @argv
+ );
+
+}
+
+# This is the internal interface that generates code.
+# NOTE: This interface WILL change in the future. Please do not
+# call this subroutine directly.
+
+# TODO: Whatever's calling this code has already looked up hints. Pass
+# them in, rather than look them up a second time.
+
+sub _one_invocation {
+ my ($class, $core, $call, $name, $void, $sub, $back_compat, $sref, @argv) = @_;
+
+
+ # If someone is calling us directly (a child class perhaps?) then
+ # they could try to mix void without enabling backwards
+ # compatibility. We just don't support this at all, so we gripe
+ # about it rather than doing something unwise.
+
+ if ($void and not $back_compat) {
+ Carp::confess("Internal error: :void mode not supported with $class");
+ }
+
+ # @argv only contains the results of the in-built prototype
+ # function, and is therefore safe to interpolate in the
+ # code generators below.
+
+ # TODO - The following clobbers context, but that's what the
+ # old Fatal did. Do we care?
+
+ if ($back_compat) {
+
+ # Use Fatal qw(system) will never be supported. It generated
+ # a compile-time error with legacy Fatal, and there's no reason
+ # to support it when autodie does a better job.
+
+ if ($call eq 'CORE::system') {
+ return q{
+ croak("UNIMPLEMENTED: use Fatal qw(system) not supported.");
+ };
+ }
+
+ local $" = ', ';
+
+ if ($void) {
+ return qq/return (defined wantarray)?$call(@argv):
+ $call(@argv) || Carp::croak("Can't $name(\@_)/ .
+ ($core ? ': $!' : ', \$! is \"$!\"') . '")'
+ } else {
+ return qq{return $call(@argv) || Carp::croak("Can't $name(\@_)} .
+ ($core ? ': $!' : ', \$! is \"$!\"') . '")';
+ }
+ }
+
+ # The name of our original function is:
+ # $call if the function is CORE
+ # $sub if our function is non-CORE
+
+ # The reason for this is that $call is what we're actually
+ # calling. For our core functions, this is always
+ # CORE::something. However for user-defined subs, we're about to
+ # replace whatever it is that we're calling; as such, we actually
+ # calling a subroutine ref.
+
+ my $human_sub_name = $core ? $call : $sub;
+
+ # Should we be testing to see if our result is defined, or
+ # just true?
+
+ my $use_defined_or;
+
+ my $hints; # All user-sub hints, including list hints.
+
+ if ( $core ) {
+
+ # Core hints are built into autodie.
+
+ $use_defined_or = exists ( $Use_defined_or{$call} );
+
+ }
+ else {
+
+ # User sub hints are looked up using autodie::hints,
+ # since users may wish to add their own hints.
+
+ require autodie::hints;
+
+ $hints = autodie::hints->get_hints_for( $sref );
+
+ # We'll look up the sub's fullname. This means we
+ # get better reports of where it came from in our
+ # error messages, rather than what imported it.
+
+ $human_sub_name = autodie::hints->sub_fullname( $sref );
+
+ }
+
+ # Checks for special core subs.
+
+ if ($call eq 'CORE::system') {
+
+ # Leverage IPC::System::Simple if we're making an autodying
+ # system.
+
+ local $" = ", ";
+
+ # We need to stash $@ into $E, rather than using
+ # local $@ for the whole sub. If we don't then
+ # any exceptions from internal errors in autodie/Fatal
+ # will mysteriously disappear before propagating
+ # upwards.
+
+ return qq{
+ my \$retval;
+ my \$E;
+
+
+ {
+ local \$@;
+
+ eval {
+ \$retval = IPC::System::Simple::system(@argv);
+ };
+
+ \$E = \$@;
+ }
+
+ if (\$E) {
+
+ # TODO - This can't be overridden in child
+ # classes!
+
+ die autodie::exception::system->new(
+ function => q{CORE::system}, args => [ @argv ],
+ message => "\$E", errno => \$!,
+ );
+ }
+
+ return \$retval;
+ };
+
+ }
+
+ local $" = ', ';
+
+ # If we're going to throw an exception, here's the code to use.
+ my $die = qq{
+ die $class->throw(
+ function => q{$human_sub_name}, args => [ @argv ],
+ pragma => q{$class}, errno => \$!,
+ context => \$context, return => \$retval,
+ eval_error => \$@
+ )
+ };
+
+ if ($call eq 'CORE::flock') {
+
+ # flock needs special treatment. When it fails with
+ # LOCK_UN and EWOULDBLOCK, then it's not really fatal, it just
+ # means we couldn't get the lock right now.
+
+ require POSIX; # For POSIX::EWOULDBLOCK
+
+ local $@; # Don't blat anyone else's $@.
+
+ # Ensure that our vendor supports EWOULDBLOCK. If they
+ # don't (eg, Windows), then we use known values for its
+ # equivalent on other systems.
+
+ my $EWOULDBLOCK = eval { POSIX::EWOULDBLOCK(); }
+ || $_EWOULDBLOCK{$^O}
+ || _autocroak("Internal error - can't overload flock - EWOULDBLOCK not defined on this system.");
+ my $EAGAIN = $EWOULDBLOCK;
+ if ($try_EAGAIN) {
+ $EAGAIN = eval { POSIX::EAGAIN(); }
+ || _autocroak("Internal error - can't overload flock - EAGAIN not defined on this system.");
+ }
+
+ require Fcntl; # For Fcntl::LOCK_NB
+
+ return qq{
+
+ my \$context = wantarray() ? "list" : "scalar";
+
+ # Try to flock. If successful, return it immediately.
+
+ my \$retval = $call(@argv);
+ return \$retval if \$retval;
+
+ # If we failed, but we're using LOCK_NB and
+ # returned EWOULDBLOCK, it's not a real error.
+
+ if (\$_[1] & Fcntl::LOCK_NB() and
+ (\$! == $EWOULDBLOCK or
+ ($try_EAGAIN and \$! == $EAGAIN ))) {
+ return \$retval;
+ }
+
+ # Otherwise, we failed. Die noisily.
+
+ $die;
+
+ };
+ }
+
+ if (exists $Returns_num_things_changed{$call}) {
+
+ # Some things return the number of things changed (like
+ # chown, kill, chmod, etc). We only consider these successful
+ # if *all* the things are changed.
+
+ return qq[
+ my \$num_things = \@_ - $Returns_num_things_changed{$call};
+ my \$retval = $call(@argv);
+
+ if (\$retval != \$num_things) {
+
+ # We need \$context to throw an exception.
+ # It's *always* set to scalar, because that's how
+ # autodie calls chown() above.
+
+ my \$context = "scalar";
+ $die;
+ }
+
+ return \$retval;
+ ];
+ }
+
+ # AFAIK everything that can be given an unopned filehandle
+ # will fail if it tries to use it, so we don't really need
+ # the 'unopened' warning class here. Especially since they
+ # then report the wrong line number.
+
+ # Other warnings are disabled because they produce excessive
+ # complaints from smart-match hints under 5.10.1.
+
+ my $code = qq[
+ no warnings qw(unopened uninitialized numeric);
+ no if \$\] >= 5.017011, warnings => "experimental::smartmatch";
+
+ if (wantarray) {
+ my \@results = $call(@argv);
+ my \$retval = \\\@results;
+ my \$context = "list";
+
+ ];
+
+ my $retval_action = $Retval_action{$call} || '';
+
+ if ( $hints and ( ref($hints->{list} ) || "" ) eq 'CODE' ) {
+
+ # NB: Subroutine hints are passed as a full list.
+ # This differs from the 5.10.0 smart-match behaviour,
+ # but means that context unaware subroutines can use
+ # the same hints in both list and scalar context.
+
+ $code .= qq{
+ if ( \$hints->{list}->(\@results) ) { $die };
+ };
+ }
+ elsif ( PERL510 and $hints ) {
+ $code .= qq{
+ if ( \@results ~~ \$hints->{list} ) { $die };
+ };
+ }
+ elsif ( $hints ) {
+ croak sprintf(ERROR_58_HINTS, 'list', $sub);
+ }
+ else {
+ $code .= qq{
+ # An empty list, or a single undef is failure
+ if (! \@results or (\@results == 1 and ! defined \$results[0])) {
+ $die;
+ }
+ }
+ }
+
+ # Tidy up the end of our wantarray call.
+
+ $code .= qq[
+ return \@results;
+ }
+ ];
+
+
+ # Otherwise, we're in scalar context.
+ # We're never in a void context, since we have to look
+ # at the result.
+
+ $code .= qq{
+ my \$retval = $call(@argv);
+ my \$context = "scalar";
+ };
+
+ if ( $hints and ( ref($hints->{scalar} ) || "" ) eq 'CODE' ) {
+
+ # We always call code refs directly, since that always
+ # works in 5.8.x, and always works in 5.10.1
+
+ return $code .= qq{
+ if ( \$hints->{scalar}->(\$retval) ) { $die };
+ $retval_action
+ return \$retval;
+ };
+
+ }
+ elsif (PERL510 and $hints) {
+ return $code . qq{
+
+ if ( \$retval ~~ \$hints->{scalar} ) { $die };
+ $retval_action
+ return \$retval;
+ };
+ }
+ elsif ( $hints ) {
+ croak sprintf(ERROR_58_HINTS, 'scalar', $sub);
+ }
+
+ return $code .
+ ( $use_defined_or ? qq{
+
+ $die if not defined \$retval;
+ $retval_action
+ return \$retval;
+
+ } : qq{
+
+ $retval_action
+ return \$retval || $die;
+
+ } ) ;
+
+}
+
+# This returns the old copy of the sub, so we can
+# put it back at end of scope.
+
+# TODO : Check to make sure prototypes are restored correctly.
+
+# TODO: Taking a huge list of arguments is awful. Rewriting to
+# take a hash would be lovely.
+
+# TODO - BACKCOMPAT - This is not yet compatible with 5.10.0
+
+sub _make_fatal {
+ my($class, $sub, $pkg, $void, $lexical, $filename, $insist, $install_subs) = @_;
+ my($code, $sref, $proto, $core, $call, $hints, $cache, $cache_type);
+ my $ini = $sub;
+ my $name = $sub;
+
+
+ if (index($sub, '::') == -1) {
+ $sub = "${pkg}::$sub";
+ if (substr($name, 0, 1) eq '&') {
+ $name = substr($name, 1);
+ }
+ } else {
+ $name =~ s/.*:://;
+ }
+
+
+ # Figure if we're using lexical or package semantics and
+ # twiddle the appropriate bits.
+
+ if (not $lexical) {
+ $Package_Fatal{$sub} = 1;
+ }
+
+ # TODO - We *should* be able to do skipping, since we know when
+ # we've lexicalised / unlexicalised a subroutine.
+
+
+ warn "# _make_fatal: sub=$sub pkg=$pkg name=$name void=$void\n" if $Debug;
+ croak(sprintf(ERROR_BADNAME, $class, $name)) unless $name =~ /^\w+$/;
+
+ if (defined(&$sub)) { # user subroutine
+
+ # NOTE: Previously we would localise $@ at this point, so
+ # the following calls to eval {} wouldn't interfere with anything
+ # that's already in $@. Unfortunately, it would also stop
+ # any of our croaks from triggering(!), which is even worse.
+
+ # This could be something that we've fatalised that
+ # was in core.
+
+ # Store the current sub in case we need to restore it.
+ $sref = \&$sub;
+
+ if ( $Package_Fatal{$sub} and exists($CORE_prototype_cache{"CORE::$name"})) {
+
+ # Something we previously made Fatal that was core.
+ # This is safe to replace with an autodying to core
+ # version.
+
+ $core = 1;
+ $call = "CORE::$name";
+ $proto = $CORE_prototype_cache{$call};
+
+ # We return our $sref from this subroutine later
+ # on, indicating this subroutine should be placed
+ # back when we're finished.
+
+
+
+ } else {
+
+ # If this is something we've already fatalised or played with,
+ # then look-up the name of the original sub for the rest of
+ # our processing.
+
+ if (exists($Is_fatalised_sub{$sref})) {
+ # $sub is one of our wrappers around a CORE sub or a
+ # user sub. Instead of wrapping our wrapper, lets just
+ # generate a new wrapper for the original sub.
+ # - NB: the current wrapper might be for a different class
+ # than the one we are generating now (e.g. some limited
+ # mixing between use Fatal + use autodie can occur).
+ # - Even for nested autodie, we need this as the leak guards
+ # differ.
+ my $s = $Is_fatalised_sub{$sref};
+ if (defined($s)) {
+ # It is a wrapper for a user sub
+ $sub = $s;
+ } else {
+ # It is a wrapper for a CORE:: sub
+ $core = 1;
+ $call = "CORE::$name";
+ $proto = $CORE_prototype_cache{$call};
+ }
+ }
+
+ # A regular user sub, or a user sub wrapping a
+ # core sub.
+
+ if (!$core) {
+ # A non-CORE sub might have hints and such...
+ $proto = prototype($sref);
+ $call = '&$sref';
+ require autodie::hints;
+
+ $hints = autodie::hints->get_hints_for( $sref );
+
+ # If we've insisted on hints, but don't have them, then
+ # bail out!
+
+ if ($insist and not $hints) {
+ croak(sprintf(ERROR_NOHINTS, $name));
+ }
+
+ # Otherwise, use the default hints if we don't have
+ # any.
+
+ $hints ||= autodie::hints::DEFAULT_HINTS();
+ }
+
+ }
+
+ } elsif ($sub eq $ini && $sub !~ /^CORE::GLOBAL::/) {
+ # Stray user subroutine
+ croak(sprintf(ERROR_NOTSUB,$sub));
+
+ } elsif ($name eq 'system') {
+
+ # If we're fatalising system, then we need to load
+ # helper code.
+
+ # The business with $E is to avoid clobbering our caller's
+ # $@, and to avoid $@ being localised when we croak.
+
+ my $E;
+
+ {
+ local $@;
+
+ eval {
+ require IPC::System::Simple; # Only load it if we need it.
+ require autodie::exception::system;
+ };
+ $E = $@;
+ }
+
+ if ($E) { croak ERROR_NO_IPC_SYS_SIMPLE; }
+
+ # Make sure we're using a recent version of ISS that actually
+ # support fatalised system.
+ if ($IPC::System::Simple::VERSION < MIN_IPC_SYS_SIMPLE_VER) {
+ croak sprintf(
+ ERROR_IPC_SYS_SIMPLE_OLD, MIN_IPC_SYS_SIMPLE_VER,
+ $IPC::System::Simple::VERSION
+ );
+ }
+
+ $call = 'CORE::system';
+ $core = 1;
+
+ } elsif ($name eq 'exec') {
+ # Exec doesn't have a prototype. We don't care. This
+ # breaks the exotic form with lexical scope, and gives
+ # the regular form a "do or die" behavior as expected.
+
+ $call = 'CORE::exec';
+ $core = 1;
+
+ } else { # CORE subroutine
+ $call = "CORE::$name";
+ if (exists($CORE_prototype_cache{$call})) {
+ $proto = $CORE_prototype_cache{$call};
+ } else {
+ my $E;
+ {
+ local $@;
+ $proto = eval { prototype $call };
+ $E = $@;
+ }
+ croak(sprintf(ERROR_NOT_BUILT,$name)) if $E;
+ croak(sprintf(ERROR_CANT_OVERRIDE,$name)) if not defined $proto;
+ $CORE_prototype_cache{$call} = $proto;
+ }
+ $core = 1;
+ }
+
+ # TODO: This caching works, but I don't like using $void and
+ # $lexical as keys. In particular, I suspect our code may end up
+ # wrapping already wrapped code when autodie and Fatal are used
+ # together.
+
+ # NB: We must use '$sub' (the name plus package) and not
+ # just '$name' (the short name) here. Failing to do so
+ # results code that's in the wrong package, and hence has
+ # access to the wrong package filehandles.
+
+ $cache = $Cached_fatalised_sub{$class}{$sub};
+ if ($lexical) {
+ $cache_type = CACHE_AUTODIE_LEAK_GUARD;
+ } else {
+ $cache_type = CACHE_FATAL_WRAPPER;
+ $cache_type = CACHE_FATAL_VOID if $void;
+ }
+
+ if (my $subref = $cache->{$cache_type}) {
+ $install_subs->{$name} = $subref;
+ return $sref;
+ }
+
+ # If our subroutine is reusable (ie, not package depdendent),
+ # then check to see if we've got a cached copy, and use that.
+ # See RT #46984. (Thanks to Niels Thykier for being awesome!)
+
+ if ($core && exists $reusable_builtins{$call}) {
+ # For non-lexical subs, we can just use this cache directly
+ # - for lexical variants, we need a leak guard as well.
+ $code = $reusable_builtins{$call}{$lexical};
+ if (!$lexical && defined($code)) {
+ $install_subs->{$name} = $code;
+ return $sref;
+ }
+ }
+
+ if (!($lexical && $core) && !defined($code)) {
+ # No code available, generate it now.
+ my $wrapper_pkg = $pkg;
+ $wrapper_pkg = undef if (exists($reusable_builtins{$call}));
+ $code = $class->_compile_wrapper($wrapper_pkg, $core, $call, $name,
+ $void, $lexical, $sub, $sref,
+ $hints, $proto);
+ if (!defined($wrapper_pkg)) {
+ # cache it so we don't recompile this part again
+ $reusable_builtins{$call}{$lexical} = $code;
+ }
+ }
+
+ # Now we need to wrap our fatalised sub inside an itty bitty
+ # closure, which can detect if we've leaked into another file.
+ # Luckily, we only need to do this for lexical (autodie)
+ # subs. Fatal subs can leak all they want, it's considered
+ # a "feature" (or at least backwards compatible).
+
+ # TODO: Cache our leak guards!
+
+ # TODO: This is pretty hairy code. A lot more tests would
+ # be really nice for this.
+
+ my $installed_sub = $code;
+
+ if ($lexical) {
+ $installed_sub = $class->_make_leak_guard($filename, $code, $sref, $call,
+ $pkg, $proto);
+ }
+
+ $cache->{$cache_type} = $code;
+
+ $install_subs->{$name} = $installed_sub;
+
+ # Cache that we've now overridden this sub. If we get called
+ # again, we may need to find that find subroutine again (eg, for hints).
+
+ $Is_fatalised_sub{$installed_sub} = $sref;
+
+ return $sref;
+
+}
+
+# This subroutine exists primarily so that child classes can override
+# it to point to their own exception class. Doing this is significantly
+# less complex than overriding throw()
+
+sub exception_class { return "autodie::exception" };
+
+{
+ my %exception_class_for;
+ my %class_loaded;
+
+ sub throw {
+ my ($class, @args) = @_;
+
+ # Find our exception class if we need it.
+ my $exception_class =
+ $exception_class_for{$class} ||= $class->exception_class;
+
+ if (not $class_loaded{$exception_class}) {
+ if ($exception_class =~ /[^\w:']/) {
+ confess "Bad exception class '$exception_class'.\nThe '$class->exception_class' method wants to use $exception_class\nfor exceptions, but it contains characters which are not word-characters or colons.";
+ }
+
+ # Alas, Perl does turn barewords into modules unless they're
+ # actually barewords. As such, we're left doing a string eval
+ # to make sure we load our file correctly.
+
+ my $E;
+
+ {
+ local $@; # We can't clobber $@, it's wrong!
+ my $pm_file = $exception_class . ".pm";
+ $pm_file =~ s{ (?: :: | ' ) }{/}gx;
+ eval { require $pm_file };
+ $E = $@; # Save $E despite ending our local.
+ }
+
+ # We need quotes around $@ to make sure it's stringified
+ # while still in scope. Without them, we run the risk of
+ # $@ having been cleared by us exiting the local() block.
+
+ confess "Failed to load '$exception_class'.\nThis may be a typo in the '$class->exception_class' method,\nor the '$exception_class' module may not exist.\n\n $E" if $E;
+
+ $class_loaded{$exception_class}++;
+
+ }
+
+ return $exception_class->new(@args);
+ }
+}
+
+# Creates and returns a leak guard (with prototype if needed).
+sub _make_leak_guard {
+ my ($class, $filename, $wrapped_sub, $orig_sub, $call, $pkg, $proto) = @_;
+
+ # The leak guard is rather lengthly (in fact it makes up the most
+ # of _make_leak_guard). It is possible to split it into a large
+ # "generic" part and a small wrapper with call-specific
+ # information. This was done in v2.19 and profiling suggested
+ # that we ended up using a substantial amount of runtime in "goto"
+ # between the leak guard(s) and the final sub. Therefore, the two
+ # parts were merged into one to reduce the runtime overhead.
+
+ my $leak_guard = sub {
+ my $caller_level = 0;
+ my $caller;
+
+ while ( ($caller = (caller $caller_level)[1]) =~ m{^\(eval \d+\)$} ) {
+
+ # If our filename is actually an eval, and we
+ # reach it, then go to our autodying code immediatately.
+
+ last if ($caller eq $filename);
+ $caller_level++;
+ }
+
+ # We're now out of the eval stack.
+
+ if ($caller eq $filename) {
+ # No leak, call the wrapper. NB: In this case, it doesn't
+ # matter if it is a CORE sub or not.
+ if (!defined($wrapped_sub)) {
+ # CORE sub that we were too lazy to compile when we
+ # created this leak guard.
+ die "$call is not CORE::<something>"
+ if substr($call, 0, 6) ne 'CORE::';
+
+ my $name = substr($call, 6);
+ my $sub = $name;
+ my $lexical = 1;
+ my $wrapper_pkg = $pkg;
+ my $code;
+ if (exists($reusable_builtins{$call})) {
+ $code = $reusable_builtins{$call}{$lexical};
+ $wrapper_pkg = undef;
+ }
+ if (!defined($code)) {
+ $code = $class->_compile_wrapper($wrapper_pkg,
+ 1, # core
+ $call,
+ $name,
+ 0, # void
+ $lexical,
+ $sub,
+ undef, # subref (not used for core)
+ undef, # hints (not used for core)
+ $proto);
+
+ if (!defined($wrapper_pkg)) {
+ # cache it so we don't recompile this part again
+ $reusable_builtins{$call}{$lexical} = $code;
+ }
+ }
+ # As $wrapped_sub is "closed over", updating its value will
+ # be "remembered" for the next call.
+ $wrapped_sub = $code;
+ }
+ goto $wrapped_sub;
+ }
+
+ # We leaked, time to call the original function.
+ # - for non-core functions that will be $orig_sub
+ # - for CORE functions, $orig_sub may be a trampoline
+ goto $orig_sub if defined($orig_sub);
+
+ # We are wrapping a CORE sub and we do not have a trampoline
+ # yet.
+ #
+ # If we've cached a trampoline, then use it. Usually only
+ # resuable subs will have cache hits, but non-reusuably ones
+ # can get it as well in (very) rare cases. It is mostly in
+ # cases where a package uses autodie multiple times and leaks
+ # from multiple places. Possibly something like:
+ #
+ # package Pkg::With::LeakyCode;
+ # sub a {
+ # use autodie;
+ # code_that_leaks();
+ # }
+ #
+ # sub b {
+ # use autodie;
+ # more_leaky_code();
+ # }
+ #
+ # Note that we use "Fatal" as package name for reusable subs
+ # because A) that allows us to trivially re-use the
+ # trampolines as well and B) because the reusable sub is
+ # compiled into "package Fatal" as well.
+
+ $pkg = 'Fatal' if exists $reusable_builtins{$call};
+ $orig_sub = $Trampoline_cache{$pkg}{$call};
+
+ if (not $orig_sub) {
+ # If we don't have a trampoline, we need to build it.
+ #
+ # We only generate trampolines when we need them, and
+ # we can cache them by subroutine + package.
+ #
+ # As $orig_sub is "closed over", updating its value will
+ # be "remembered" for the next call.
+
+ $orig_sub = make_core_trampoline($call, $pkg, $proto);
+
+ # We still cache it despite remembering it in $orig_sub as
+ # well. In particularly, we rely on this to avoid
+ # re-compiling the reusable trampolines.
+ $Trampoline_cache{$pkg}{$call} = $orig_sub;
+ }
+
+ # Bounce to our trampoline, which takes us to our core sub.
+ goto $orig_sub;
+ }; # <-- end of leak guard
+
+ # If there is a prototype on the original sub, copy it to the leak
+ # guard.
+ if (defined $proto) {
+ # The "\&" may appear to be redundant but set_prototype
+ # croaks when it is removed.
+ set_prototype(\&$leak_guard, $proto);
+ }
+
+ return $leak_guard;
+}
+
+sub _compile_wrapper {
+ my ($class, $wrapper_pkg, $core, $call, $name, $void, $lexical, $sub, $sref, $hints, $proto) = @_;
+ my $real_proto = '';
+ my @protos;
+ my $code;
+ if (defined $proto) {
+ $real_proto = " ($proto)";
+ } else {
+ $proto = '@';
+ }
+
+ @protos = fill_protos($proto);
+ $code = qq[
+ sub$real_proto {
+ ];
+
+ if (!$lexical) {
+ $code .= q[
+ local($", $!) = (', ', 0);
+ ];
+ }
+
+ # Don't have perl whine if exec fails, since we'll be handling
+ # the exception now.
+ $code .= "no warnings qw(exec);\n" if $call eq "CORE::exec";
+
+ $code .= $class->_write_invocation($core, $call, $name, $void, $lexical,
+ $sub, $sref, @protos);
+ $code .= "}\n";
+ warn $code if $Debug;
+
+ # I thought that changing package was a monumental waste of
+ # time for CORE subs, since they'll always be the same. However
+ # that's not the case, since they may refer to package-based
+ # filehandles (eg, with open).
+ #
+ # The %reusable_builtins hash defines ones we can aggressively
+ # cache as they never depend upon package-based symbols.
+
+ my $E;
+
+ {
+ no strict 'refs'; ## no critic # to avoid: Can't use string (...) as a symbol ref ...
+ local $@;
+ if (defined($wrapper_pkg)) {
+ $code = eval("package $wrapper_pkg; require Carp; $code"); ## no critic
+ } else {
+ $code = eval("require Carp; $code"); ## no critic
+
+ }
+ $E = $@;
+ }
+
+ if (not $code) {
+ my $true_name = $core ? $call : $sub;
+ croak("Internal error in autodie/Fatal processing $true_name: $E");
+ }
+ return $code;
+}
+
+# For some reason, dying while replacing our subs doesn't
+# kill our calling program. It simply stops the loading of
+# autodie and keeps going with everything else. The _autocroak
+# sub allows us to die with a vengeance. It should *only* ever be
+# used for serious internal errors, since the results of it can't
+# be captured.
+
+sub _autocroak {
+ warn Carp::longmess(@_);
+ exit(255); # Ugh!
+}
+
+1;
+
+__END__
+
+=head1 NAME
+
+Fatal - Replace functions with equivalents which succeed or die
+
+=head1 SYNOPSIS
+
+ use Fatal qw(open close);
+
+ open(my $fh, "<", $filename); # No need to check errors!
+
+ use File::Copy qw(move);
+ use Fatal qw(move);
+
+ move($file1, $file2); # No need to check errors!
+
+ sub juggle { . . . }
+ Fatal->import('juggle');
+
+=head1 BEST PRACTICE
+
+B<Fatal has been obsoleted by the new L<autodie> pragma.> Please use
+L<autodie> in preference to C<Fatal>. L<autodie> supports lexical scoping,
+throws real exception objects, and provides much nicer error messages.
+
+The use of C<:void> with Fatal is discouraged.
+
+=head1 DESCRIPTION
+
+C<Fatal> provides a way to conveniently replace
+functions which normally return a false value when they fail with
+equivalents which raise exceptions if they are not successful. This
+lets you use these functions without having to test their return
+values explicitly on each call. Exceptions can be caught using
+C<eval{}>. See L<perlfunc> and L<perlvar> for details.
+
+The do-or-die equivalents are set up simply by calling Fatal's
+C<import> routine, passing it the names of the functions to be
+replaced. You may wrap both user-defined functions and overridable
+CORE operators (except C<exec>, C<system>, C<print>, or any other
+built-in that cannot be expressed via prototypes) in this way.
+
+If the symbol C<:void> appears in the import list, then functions
+named later in that import list raise an exception only when
+these are called in void context--that is, when their return
+values are ignored. For example
+
+ use Fatal qw/:void open close/;
+
+ # properly checked, so no exception raised on error
+ if (not open(my $fh, '<', '/bogotic') {
+ warn "Can't open /bogotic: $!";
+ }
+
+ # not checked, so error raises an exception
+ close FH;
+
+The use of C<:void> is discouraged, as it can result in exceptions
+not being thrown if you I<accidentally> call a method without
+void context. Use L<autodie> instead if you need to be able to
+disable autodying/Fatal behaviour for a small block of code.
+
+=head1 DIAGNOSTICS
+
+=over 4
+
+=item Bad subroutine name for Fatal: %s
+
+You've called C<Fatal> with an argument that doesn't look like
+a subroutine name, nor a switch that this version of Fatal
+understands.
+
+=item %s is not a Perl subroutine
+
+You've asked C<Fatal> to try and replace a subroutine which does not
+exist, or has not yet been defined.
+
+=item %s is neither a builtin, nor a Perl subroutine
+
+You've asked C<Fatal> to replace a subroutine, but it's not a Perl
+built-in, and C<Fatal> couldn't find it as a regular subroutine.
+It either doesn't exist or has not yet been defined.
+
+=item Cannot make the non-overridable %s fatal
+
+You've tried to use C<Fatal> on a Perl built-in that can't be
+overridden, such as C<print> or C<system>, which means that
+C<Fatal> can't help you, although some other modules might.
+See the L</"SEE ALSO"> section of this documentation.
+
+=item Internal error: %s
+
+You've found a bug in C<Fatal>. Please report it using
+the C<perlbug> command.
+
+=back
+
+=head1 BUGS
+
+C<Fatal> clobbers the context in which a function is called and always
+makes it a scalar context, except when the C<:void> tag is used.
+This problem does not exist in L<autodie>.
+
+"Used only once" warnings can be generated when C<autodie> or C<Fatal>
+is used with package filehandles (eg, C<FILE>). It's strongly recommended
+you use scalar filehandles instead.
+
+=head1 AUTHOR
+
+Original module by Lionel Cons (CERN).
+
+Prototype updates by Ilya Zakharevich <ilya@math.ohio-state.edu>.
+
+L<autodie> support, bugfixes, extended diagnostics, C<system>
+support, and major overhauling by Paul Fenwick <pjf@perltraining.com.au>
+
+=head1 LICENSE
+
+This module is free software, you may distribute it under the
+same terms as Perl itself.
+
+=head1 SEE ALSO
+
+L<autodie> for a nicer way to use lexical Fatal.
+
+L<IPC::System::Simple> for a similar idea for calls to C<system()>
+and backticks.
+
+=for Pod::Coverage exception_class fill_protos one_invocation throw write_invocation ERROR_NO_IPC_SYS_SIMPLE LEXICAL_TAG
+
+=cut