Unbundle dpkg-shlibdeps

third_party/dpkg-dev/scripts/Dpkg/Shlibs/Cppfilt.pm

-# Copyright © 2009-2010 Modestas Vainius <modax@debian.org>
-#
-# This program is free software; you can redistribute it and/or modify
-# it under the terms of the GNU General Public License as published by
-# the Free Software Foundation; either version 2 of the License, or
-# (at your option) any later version.
-#
-# This program is distributed in the hope that it will be useful,
-# but WITHOUT ANY WARRANTY; without even the implied warranty of
-# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
-# GNU General Public License for more details.
-#
-# You should have received a copy of the GNU General Public License
-# along with this program.  If not, see <https://www.gnu.org/licenses/>.
-
-package Dpkg::Shlibs::Cppfilt;
-
-use strict;
-use warnings;
-
-our $VERSION = '0.01';
-
-use Exporter qw(import);
-
-use Dpkg::ErrorHandling;
-use Dpkg::IPC;
-use IO::Handle;
-
-our @EXPORT = qw(cppfilt_demangle_cpp);
-our @EXPORT_OK = qw(cppfilt_demangle);
-
-# A hash of 'objects' referring to preforked c++filt processes for the distinct
-# demangling types.
-my %cppfilts;
-
-sub get_cppfilt {
-    my $type = shift || 'auto';
-
-    # Fork c++filt process for demangling $type unless it is forked already.
-    # Keeping c++filt running improves performance a lot.
-    my $filt;
-    if (exists $cppfilts{$type}) {
-        $filt = $cppfilts{$type};
-    } else {
-        $filt = { from => undef, to => undef,
-                    last_symbol => '', last_result => '' };
-        $filt->{pid} = spawn(exec => [ 'c++filt', "--format=$type" ],
-                             from_pipe => \$filt->{from},
-                             to_pipe => \$filt->{to});
-        syserr(_g('unable to execute %s'), 'c++filt')
-            unless defined $filt->{from};
-        $filt->{from}->autoflush(1);
-
-        $cppfilts{$type} = $filt;
-    }
-    return $filt;
-}
-
-# Demangle the given $symbol using demangler for the specified $type (defaults
-# to 'auto') . Extraneous characters trailing after a mangled name are kept
-# intact. If neither whole $symbol nor portion of it could be demangled, undef
-# is returned.
-sub cppfilt_demangle {
-    my ($symbol, $type) = @_;
-
-    # Start or get c++filt 'object' for the requested type.
-    my $filt = get_cppfilt($type);
-
-    # Remember the last result. Such a local optimization is cheap and useful
-    # when sequential pattern matching is performed.
-    if ($filt->{last_symbol} ne $symbol) {
-        # This write/read operation should not deadlock because c++filt flushes
-        # output buffer on LF or each invalid character.
-        print { $filt->{from} } $symbol, "\n";
-        my $demangled = readline($filt->{to});
-        chop $demangled;
-
-        # If the symbol was not demangled, return undef
-        $demangled = undef if $symbol eq $demangled;
-
-        # Remember the last result
-        $filt->{last_symbol} = $symbol;
-        $filt->{last_result} = $demangled;
-    }
-    return $filt->{last_result};
-}
-
-sub cppfilt_demangle_cpp {
-    my $symbol = shift;
-    return cppfilt_demangle($symbol, 'auto');
-}
-
-sub terminate_cppfilts {
-    foreach (keys %cppfilts) {
-        next if not defined $cppfilts{$_}{pid};
-        close $cppfilts{$_}{from};
-        close $cppfilts{$_}{to};
-        wait_child($cppfilts{$_}{pid}, cmdline => 'c++filt',
-                                       nocheck => 1,
-                                       timeout => 5);
-        delete $cppfilts{$_};
-    }
-}
-
-# Close/terminate running c++filt process(es)
-END {
-    # Make sure exitcode is not changed (by wait_child)
-    my $exitcode = $?;
-    terminate_cppfilts();
-    $? = $exitcode;
-}
-
-1;