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# 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 <http://www.gnu.org/licenses/>.
package Dpkg::Shlibs::Cppfilt;
use strict;
use warnings;
our $VERSION = '0.01';
use base 'Exporter';
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});
internerr(_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;
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