Adding upstream version 1.21.22.upstream/1.21.22upstream

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

4 files changed, 1930 insertions, 0 deletions

diff --git a/scripts/Dpkg/Shlibs/Cppfilt.pm b/scripts/Dpkg/Shlibs/Cppfilt.pm
new file mode 100644
index 0000000..c2a4756
--- /dev/null
+++ b/scripts/Dpkg/Shlibs/Cppfilt.pm
@@ -0,0 +1,120 @@
+# Copyright © 2009-2010 Modestas Vainius <modax@debian.org>
+# Copyright © 2010, 2012-2015 Guillem Jover <guillem@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';
+our @EXPORT = qw(
+    cppfilt_demangle_cpp
+);
+our @EXPORT_OK = qw(
+    cppfilt_demangle
+);
+
+use Exporter qw(import);
+
+use Dpkg::ErrorHandling;
+use Dpkg::IPC;
+
+# 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 my $type (keys %cppfilts) {
+	next if not defined $cppfilts{$type}{pid};
+	close $cppfilts{$type}{from};
+	close $cppfilts{$type}{to};
+	wait_child($cppfilts{$type}{pid}, cmdline => 'c++filt',
+	                                  nocheck => 1,
+	                                  timeout => 5);
+	delete $cppfilts{$type};
+    }
+}
+
+# Close/terminate running c++filt process(es)
+END {
+    # Make sure exitcode is not changed (by wait_child)
+    my $exitcode = $?;
+    terminate_cppfilts();
+    $? = $exitcode;
+}
+
+1;
diff --git a/scripts/Dpkg/Shlibs/Objdump.pm b/scripts/Dpkg/Shlibs/Objdump.pm
new file mode 100644
index 0000000..c9af965
--- /dev/null
+++ b/scripts/Dpkg/Shlibs/Objdump.pm
@@ -0,0 +1,582 @@
+# Copyright © 2007-2010 Raphaël Hertzog <hertzog@debian.org>
+# Copyright © 2007-2009,2012-2015,2017-2018 Guillem Jover <guillem@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::Objdump;
+
+use strict;
+use warnings;
+use feature qw(state);
+
+our $VERSION = '0.01';
+
+use Dpkg::Gettext;
+use Dpkg::ErrorHandling;
+
+sub new {
+    my $this = shift;
+    my $class = ref($this) || $this;
+    my $self = { objects => {} };
+    bless $self, $class;
+    return $self;
+}
+
+sub add_object {
+    my ($self, $obj) = @_;
+    my $id = $obj->get_id;
+    if ($id) {
+	$self->{objects}{$id} = $obj;
+    }
+    return $id;
+}
+
+sub analyze {
+    my ($self, $file) = @_;
+    my $obj = Dpkg::Shlibs::Objdump::Object->new($file);
+
+    return $self->add_object($obj);
+}
+
+sub locate_symbol {
+    my ($self, $name) = @_;
+    foreach my $obj (values %{$self->{objects}}) {
+	my $sym = $obj->get_symbol($name);
+	if (defined($sym) && $sym->{defined}) {
+	    return $sym;
+	}
+    }
+    return;
+}
+
+sub get_object {
+    my ($self, $objid) = @_;
+    if ($self->has_object($objid)) {
+	return $self->{objects}{$objid};
+    }
+    return;
+}
+
+sub has_object {
+    my ($self, $objid) = @_;
+    return exists $self->{objects}{$objid};
+}
+
+use constant {
+    # ELF Class.
+    ELF_BITS_NONE           => 0,
+    ELF_BITS_32             => 1,
+    ELF_BITS_64             => 2,
+
+    # ELF Data encoding.
+    ELF_ORDER_NONE          => 0,
+    ELF_ORDER_2LSB          => 1,
+    ELF_ORDER_2MSB          => 2,
+
+    # ELF Machine.
+    EM_SPARC                => 2,
+    EM_MIPS                 => 8,
+    EM_SPARC64_OLD          => 11,
+    EM_SPARC32PLUS          => 18,
+    EM_PPC64                => 21,
+    EM_S390                 => 22,
+    EM_ARM                  => 40,
+    EM_ALPHA_OLD            => 41,
+    EM_SH                   => 42,
+    EM_SPARC64              => 43,
+    EM_IA64                 => 50,
+    EM_AVR                  => 83,
+    EM_M32R                 => 88,
+    EM_MN10300              => 89,
+    EM_MN10200              => 90,
+    EM_OR1K                 => 92,
+    EM_XTENSA               => 94,
+    EM_MICROBLAZE           => 189,
+    EM_ARCV2                => 195,
+    EM_LOONGARCH            => 258,
+    EM_AVR_OLD              => 0x1057,
+    EM_OR1K_OLD             => 0x8472,
+    EM_ALPHA                => 0x9026,
+    EM_M32R_CYGNUS          => 0x9041,
+    EM_S390_OLD             => 0xa390,
+    EM_XTENSA_OLD           => 0xabc7,
+    EM_MICROBLAZE_OLD       => 0xbaab,
+    EM_MN10300_CYGNUS       => 0xbeef,
+    EM_MN10200_CYGNUS       => 0xdead,
+
+    # ELF Version.
+    EV_NONE                 => 0,
+    EV_CURRENT              => 1,
+
+    # ELF Flags (might influence the ABI).
+    EF_ARM_ALIGN8           => 0x00000040,
+    EF_ARM_NEW_ABI          => 0x00000080,
+    EF_ARM_OLD_ABI          => 0x00000100,
+    EF_ARM_SOFT_FLOAT       => 0x00000200,
+    EF_ARM_HARD_FLOAT       => 0x00000400,
+    EF_ARM_EABI_MASK        => 0xff000000,
+
+    EF_IA64_ABI64           => 0x00000010,
+
+    EF_LOONGARCH_SOFT_FLOAT     => 0x00000001,
+    EF_LOONGARCH_SINGLE_FLOAT   => 0x00000002,
+    EF_LOONGARCH_DOUBLE_FLOAT   => 0x00000003,
+    EF_LOONGARCH_ABI_MASK       => 0x00000007,
+
+    EF_MIPS_ABI2            => 0x00000020,
+    EF_MIPS_32BIT           => 0x00000100,
+    EF_MIPS_FP64            => 0x00000200,
+    EF_MIPS_NAN2008         => 0x00000400,
+    EF_MIPS_ABI_MASK        => 0x0000f000,
+    EF_MIPS_ARCH_MASK       => 0xf0000000,
+
+    EF_PPC64_ABI64          => 0x00000003,
+
+    EF_SH_MACH_MASK         => 0x0000001f,
+};
+
+# These map alternative or old machine IDs to their canonical form.
+my %elf_mach_map = (
+    EM_ALPHA_OLD()          => EM_ALPHA,
+    EM_AVR_OLD()            => EM_AVR,
+    EM_M32R_CYGNUS()        => EM_M32R,
+    EM_MICROBLAZE_OLD()     => EM_MICROBLAZE,
+    EM_MN10200_CYGNUS()     => EM_MN10200,
+    EM_MN10300_CYGNUS()     => EM_MN10300,
+    EM_OR1K_OLD()           => EM_OR1K,
+    EM_S390_OLD()           => EM_S390,
+    EM_SPARC32PLUS()        => EM_SPARC,
+    EM_SPARC64_OLD()        => EM_SPARC64,
+    EM_XTENSA_OLD()         => EM_XTENSA,
+);
+
+# These masks will try to expose processor flags that are ABI incompatible,
+# and as such are part of defining the architecture ABI. If uncertain it is
+# always better to not mask a flag, because that preserves the historical
+# behavior, and we do not drop dependencies.
+my %elf_flags_mask = (
+    EM_IA64()               => EF_IA64_ABI64,
+    EM_LOONGARCH()          => EF_LOONGARCH_ABI_MASK,
+    EM_MIPS()               => EF_MIPS_ABI_MASK | EF_MIPS_ABI2,
+    EM_PPC64()              => EF_PPC64_ABI64,
+);
+
+sub get_format {
+    my ($file) = @_;
+    state %format;
+
+    return $format{$file} if exists $format{$file};
+
+    my $header;
+
+    open my $fh, '<', $file or syserr(g_('cannot read %s'), $file);
+    my $rc = read $fh, $header, 64;
+    if (not defined $rc) {
+        syserr(g_('cannot read %s'), $file);
+    } elsif ($rc != 64) {
+        return;
+    }
+    close $fh;
+
+    my %elf;
+
+    # Unpack the identifier field.
+    @elf{qw(magic bits endian vertype osabi verabi)} = unpack 'a4C5', $header;
+
+    return unless $elf{magic} eq "\x7fELF";
+    return unless $elf{vertype} == EV_CURRENT;
+
+    my ($elf_word, $elf_endian);
+    if ($elf{bits} == ELF_BITS_32) {
+        $elf_word = 'L';
+    } elsif ($elf{bits} == ELF_BITS_64) {
+        $elf_word = 'Q';
+    } else {
+        return;
+    }
+    if ($elf{endian} == ELF_ORDER_2LSB) {
+        $elf_endian = '<';
+    } elsif ($elf{endian} == ELF_ORDER_2MSB) {
+        $elf_endian = '>';
+    } else {
+        return;
+    }
+
+    # Unpack the endianness and size dependent fields.
+    my $tmpl = "x16(S2Lx[${elf_word}3]L)${elf_endian}";
+    @elf{qw(type mach version flags)} = unpack $tmpl, $header;
+
+    # Canonicalize the machine ID.
+    $elf{mach} = $elf_mach_map{$elf{mach}} // $elf{mach};
+
+    # Mask any processor flags that might not change the architecture ABI.
+    $elf{flags} &= $elf_flags_mask{$elf{mach}} // 0;
+
+    # Repack for easy comparison, as a big-endian byte stream, so that
+    # unpacking for output gives meaningful results.
+    $format{$file} = pack 'C2(SL)>', @elf{qw(bits endian mach flags)};
+
+    return $format{$file};
+}
+
+sub is_elf {
+    my $file = shift;
+    open(my $file_fh, '<', $file) or syserr(g_('cannot read %s'), $file);
+    my ($header, $result) = ('', 0);
+    if (read($file_fh, $header, 4) == 4) {
+	$result = 1 if ($header =~ /^\177ELF$/);
+    }
+    close($file_fh);
+    return $result;
+}
+
+package Dpkg::Shlibs::Objdump::Object;
+
+use strict;
+use warnings;
+use feature qw(state);
+
+use Dpkg::Gettext;
+use Dpkg::ErrorHandling;
+use Dpkg::Path qw(find_command);
+use Dpkg::Arch qw(debarch_to_gnutriplet get_build_arch get_host_arch);
+
+sub new {
+    my $this = shift;
+    my $file = shift // '';
+    my $class = ref($this) || $this;
+    my $self = {};
+    bless $self, $class;
+
+    $self->reset;
+    if ($file) {
+	$self->analyze($file);
+    }
+
+    return $self;
+}
+
+sub reset {
+    my $self = shift;
+
+    $self->{file} = '';
+    $self->{id} = '';
+    $self->{HASH} = '';
+    $self->{GNU_HASH} = '';
+    $self->{INTERP} = 0;
+    $self->{SONAME} = '';
+    $self->{NEEDED} = [];
+    $self->{RPATH} = [];
+    $self->{dynsyms} = {};
+    $self->{flags} = {};
+    $self->{dynrelocs} = {};
+
+    return $self;
+}
+
+sub _select_objdump {
+    # Decide which objdump to call
+    if (get_build_arch() ne get_host_arch()) {
+        my $od = debarch_to_gnutriplet(get_host_arch()) . '-objdump';
+        return $od if find_command($od);
+    }
+    return 'objdump';
+}
+
+sub analyze {
+    my ($self, $file) = @_;
+
+    $file ||= $self->{file};
+    return unless $file;
+
+    $self->reset;
+    $self->{file} = $file;
+
+    $self->{exec_abi} = Dpkg::Shlibs::Objdump::get_format($file);
+
+    if (not defined $self->{exec_abi}) {
+        warning(g_("unknown executable format in file '%s'"), $file);
+        return;
+    }
+
+    state $OBJDUMP = _select_objdump();
+    local $ENV{LC_ALL} = 'C';
+    open(my $objdump, '-|', $OBJDUMP, '-w', '-f', '-p', '-T', '-R', $file)
+        or syserr(g_('cannot fork for %s'), $OBJDUMP);
+    my $ret = $self->parse_objdump_output($objdump);
+    close($objdump);
+    return $ret;
+}
+
+sub parse_objdump_output {
+    my ($self, $fh) = @_;
+
+    my $section = 'none';
+    while (<$fh>) {
+	s/\s*$//;
+	next if length == 0;
+
+	if (/^DYNAMIC SYMBOL TABLE:/) {
+	    $section = 'dynsym';
+	    next;
+	} elsif (/^DYNAMIC RELOCATION RECORDS/) {
+	    $section = 'dynreloc';
+	    $_ = <$fh>; # Skip header
+	    next;
+	} elsif (/^Dynamic Section:/) {
+	    $section = 'dyninfo';
+	    next;
+	} elsif (/^Program Header:/) {
+	    $section = 'program';
+	    next;
+	} elsif (/^Version definitions:/) {
+	    $section = 'verdef';
+	    next;
+	} elsif (/^Version References:/) {
+	    $section = 'verref';
+	    next;
+	}
+
+	if ($section eq 'dynsym') {
+	    $self->parse_dynamic_symbol($_);
+	} elsif ($section eq 'dynreloc') {
+	    if (/^\S+\s+(\S+)\s+(.+)$/) {
+		$self->{dynrelocs}{$2} = $1;
+	    } else {
+		warning(g_("couldn't parse dynamic relocation record: %s"), $_);
+	    }
+	} elsif ($section eq 'dyninfo') {
+	    if (/^\s*NEEDED\s+(\S+)/) {
+		push @{$self->{NEEDED}}, $1;
+	    } elsif (/^\s*SONAME\s+(\S+)/) {
+		$self->{SONAME} = $1;
+	    } elsif (/^\s*HASH\s+(\S+)/) {
+		$self->{HASH} = $1;
+	    } elsif (/^\s*GNU_HASH\s+(\S+)/) {
+		$self->{GNU_HASH} = $1;
+	    } elsif (/^\s*RUNPATH\s+(\S+)/) {
+                # RUNPATH takes precedence over RPATH but is
+                # considered after LD_LIBRARY_PATH while RPATH
+                # is considered before (if RUNPATH is not set).
+                my $runpath = $1;
+                $self->{RPATH} = [ split /:/, $runpath ];
+	    } elsif (/^\s*RPATH\s+(\S+)/) {
+                my $rpath = $1;
+                unless (scalar(@{$self->{RPATH}})) {
+                    $self->{RPATH} = [ split /:/, $rpath ];
+                }
+	    }
+        } elsif ($section eq 'program') {
+            if (/^\s*INTERP\s+/) {
+                $self->{INTERP} = 1;
+            }
+	} elsif ($section eq 'none') {
+	    if (/^\s*.+:\s*file\s+format\s+(\S+)$/) {
+		$self->{format} = $1;
+	    } elsif (/^architecture:\s*\S+,\s*flags\s*\S+:$/) {
+		# Parse 2 lines of "-f"
+		# architecture: i386, flags 0x00000112:
+		# EXEC_P, HAS_SYMS, D_PAGED
+		# start address 0x08049b50
+		$_ = <$fh>;
+		chomp;
+		$self->{flags}{$_} = 1 foreach (split(/,\s*/));
+	    }
+	}
+    }
+    # Update status of dynamic symbols given the relocations that have
+    # been parsed after the symbols...
+    $self->apply_relocations();
+
+    return $section ne 'none';
+}
+
+# Output format of objdump -w -T
+#
+# /lib/libc.so.6:     file format elf32-i386
+#
+# DYNAMIC SYMBOL TABLE:
+# 00056ef0 g    DF .text  000000db  GLIBC_2.2   getwchar
+# 00000000 g    DO *ABS*  00000000  GCC_3.0     GCC_3.0
+# 00069960  w   DF .text  0000001e  GLIBC_2.0   bcmp
+# 00000000  w   D  *UND*  00000000              _pthread_cleanup_pop_restore
+# 0000b788 g    DF .text  0000008e  Base        .protected xine_close
+# 0000b788 g    DF .text  0000008e              .hidden IA__g_free
+# |        ||||||| |      |         |           |
+# |        ||||||| |      |         Version str (.visibility) + Symbol name
+# |        ||||||| |      Alignment
+# |        ||||||| Section name (or *UND* for an undefined symbol)
+# |        ||||||F=Function,f=file,O=object
+# |        |||||d=debugging,D=dynamic
+# |        ||||I=Indirect
+# |        |||W=warning
+# |        ||C=constructor
+# |        |w=weak
+# |        g=global,l=local,!=both global/local
+# Size of the symbol
+#
+# GLIBC_2.2 is the version string associated to the symbol
+# (GLIBC_2.2) is the same but the symbol is hidden, a newer version of the
+# symbol exist
+
+my $vis_re = qr/(\.protected|\.hidden|\.internal|0x\S+)/;
+my $dynsym_re = qr<
+    ^
+    [0-9a-f]+                   # Symbol size
+    \ (.{7})                    # Flags
+    \s+(\S+)                    # Section name
+    \s+[0-9a-f]+                # Alignment
+    (?:\s+(\S+))?               # Version string
+    (?:\s+$vis_re)?             # Visibility
+    \s+(.+)                     # Symbol name
+>x;
+
+sub parse_dynamic_symbol {
+    my ($self, $line) = @_;
+    if ($line =~ $dynsym_re) {
+	my ($flags, $sect, $ver, $vis, $name) = ($1, $2, $3, $4, $5);
+
+	# Special case if version is missing but extra visibility
+	# attribute replaces it in the match
+	if (defined($ver) and $ver =~ /^$vis_re$/) {
+	    $vis = $ver;
+	    $ver = '';
+	}
+
+	# Cleanup visibility field
+	$vis =~ s/^\.// if defined($vis);
+
+	my $symbol = {
+		name => $name,
+		version => $ver // '',
+		section => $sect,
+		dynamic => substr($flags, 5, 1) eq 'D',
+		debug => substr($flags, 5, 1) eq 'd',
+		type => substr($flags, 6, 1),
+		weak => substr($flags, 1, 1) eq 'w',
+		local => substr($flags, 0, 1) eq 'l',
+		global => substr($flags, 0, 1) eq 'g',
+		visibility => $vis // '',
+		hidden => '',
+		defined => $sect ne '*UND*'
+	    };
+
+	# Handle hidden symbols
+	if (defined($ver) and $ver =~ /^\((.*)\)$/) {
+	    $ver = $1;
+	    $symbol->{version} = $1;
+	    $symbol->{hidden} = 1;
+	}
+
+	# Register symbol
+	$self->add_dynamic_symbol($symbol);
+    } elsif ($line =~ /^[0-9a-f]+ (.{7})\s+(\S+)\s+[0-9a-f]+/) {
+	# Same start but no version and no symbol ... just ignore
+    } elsif ($line =~ /^REG_G\d+\s+/) {
+	# Ignore some s390-specific output like
+	# REG_G6           g     R *UND*      0000000000000000              #scratch
+    } else {
+	warning(g_("couldn't parse dynamic symbol definition: %s"), $line);
+    }
+}
+
+sub apply_relocations {
+    my $self = shift;
+    foreach my $sym (values %{$self->{dynsyms}}) {
+	# We want to mark as undefined symbols those which are currently
+	# defined but that depend on a copy relocation
+	next if not $sym->{defined};
+
+        my @relocs;
+
+        # When objdump qualifies the symbol with a version it will use @ when
+        # the symbol is in an undefined section (which we discarded above, or
+        # @@ otherwise.
+        push @relocs, $sym->{name} . '@@' . $sym->{version} if $sym->{version};
+
+        # Symbols that are not versioned, or versioned but shown with objdump
+        # from binutils < 2.26, do not have a version appended.
+        push @relocs, $sym->{name};
+
+        foreach my $reloc (@relocs) {
+            next if not exists $self->{dynrelocs}{$reloc};
+            next if not $self->{dynrelocs}{$reloc} =~ /^R_.*_COPY$/;
+
+	    $sym->{defined} = 0;
+            last;
+	}
+    }
+}
+
+sub add_dynamic_symbol {
+    my ($self, $symbol) = @_;
+    $symbol->{objid} = $symbol->{soname} = $self->get_id();
+    $symbol->{soname} =~ s{^.*/}{} unless $self->{SONAME};
+    if ($symbol->{version}) {
+	$self->{dynsyms}{$symbol->{name} . '@' . $symbol->{version}} = $symbol;
+    } else {
+	$self->{dynsyms}{$symbol->{name} . '@Base'} = $symbol;
+    }
+}
+
+sub get_id {
+    my $self = shift;
+    return $self->{SONAME} || $self->{file};
+}
+
+sub get_symbol {
+    my ($self, $name) = @_;
+    if (exists $self->{dynsyms}{$name}) {
+	return $self->{dynsyms}{$name};
+    }
+    if ($name !~ /@/) {
+        if (exists $self->{dynsyms}{$name . '@Base'}) {
+            return $self->{dynsyms}{$name . '@Base'};
+        }
+    }
+    return;
+}
+
+sub get_exported_dynamic_symbols {
+    my $self = shift;
+    return grep {
+        $_->{defined} && $_->{dynamic} && !$_->{local}
+    } values %{$self->{dynsyms}};
+}
+
+sub get_undefined_dynamic_symbols {
+    my $self = shift;
+    return grep {
+        (!$_->{defined}) && $_->{dynamic}
+    } values %{$self->{dynsyms}};
+}
+
+sub get_needed_libraries {
+    my $self = shift;
+    return @{$self->{NEEDED}};
+}
+
+sub is_executable {
+    my $self = shift;
+    return (exists $self->{flags}{EXEC_P} && $self->{flags}{EXEC_P}) ||
+           (exists $self->{INTERP} && $self->{INTERP});
+}
+
+sub is_public_library {
+    my $self = shift;
+    return exists $self->{flags}{DYNAMIC} && $self->{flags}{DYNAMIC}
+	&& exists $self->{SONAME} && $self->{SONAME};
+}
+
+1;
diff --git a/scripts/Dpkg/Shlibs/Symbol.pm b/scripts/Dpkg/Shlibs/Symbol.pm
new file mode 100644
index 0000000..e6460ce
--- /dev/null
+++ b/scripts/Dpkg/Shlibs/Symbol.pm
@@ -0,0 +1,531 @@
+# Copyright © 2007 Raphaël Hertzog <hertzog@debian.org>
+# 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::Symbol;
+
+use strict;
+use warnings;
+
+our $VERSION = '0.01';
+
+use Storable ();
+use List::Util qw(any);
+
+use Dpkg::Gettext;
+use Dpkg::ErrorHandling;
+use Dpkg::Arch qw(debarch_is_concerned debarch_to_abiattrs);
+use Dpkg::Version;
+use Dpkg::Shlibs::Cppfilt;
+
+# Supported alias types in the order of matching preference
+use constant ALIAS_TYPES => qw(
+    c++
+    symver
+);
+
+# Needed by the deprecated key, which is a correct use.
+no if $Dpkg::Version::VERSION ge '1.02',
+    warnings => qw(Dpkg::Version::semantic_change::overload::bool);
+
+sub new {
+    my ($this, %args) = @_;
+    my $class = ref($this) || $this;
+    my $self = bless {
+	symbol => undef,
+	symbol_templ => undef,
+	minver => undef,
+	dep_id => 0,
+	deprecated => 0,
+	tags => {},
+	tagorder => [],
+    }, $class;
+    $self->{$_} = $args{$_} foreach keys %args;
+    return $self;
+}
+
+# Deep clone
+sub clone {
+    my ($self, %args) = @_;
+    my $clone = Storable::dclone($self);
+    $clone->{$_} = $args{$_} foreach keys %args;
+    return $clone;
+}
+
+sub parse_tagspec {
+    my ($self, $tagspec) = @_;
+
+    if ($tagspec =~ /^\s*\((.*?)\)(.*)$/ && $1) {
+	# (tag1=t1 value|tag2|...|tagN=tNp)
+	# Symbols ()|= cannot appear in the tag names and values
+	my $tagspec = $1;
+	my $rest = ($2) ? $2 : '';
+	my @tags = split(/\|/, $tagspec);
+
+	# Parse each tag
+	for my $tag (@tags) {
+	    if ($tag =~ /^(.*)=(.*)$/) {
+		# Tag with value
+		$self->add_tag($1, $2);
+	    } else {
+		# Tag without value
+		$self->add_tag($tag, undef);
+	    }
+	}
+	return $rest;
+    }
+    return;
+}
+
+sub parse_symbolspec {
+    my ($self, $symbolspec, %opts) = @_;
+    my $symbol;
+    my $symbol_templ;
+    my $symbol_quoted;
+    my $rest;
+
+    if (defined($symbol = $self->parse_tagspec($symbolspec))) {
+	# (tag1=t1 value|tag2|...|tagN=tNp)"Foo::Bar::foobar()"@Base 1.0 1
+	# Symbols ()|= cannot appear in the tag names and values
+
+	# If the tag specification exists symbol name template might be quoted too
+	if ($symbol =~ /^(['"])/ && $symbol =~ /^($1)(.*?)$1(.*)$/) {
+	    $symbol_quoted = $1;
+	    $symbol_templ = $2;
+	    $symbol = $2;
+	    $rest = $3;
+	} else {
+	    if ($symbol =~ m/^(\S+)(.*)$/) {
+		$symbol_templ = $1;
+		$symbol = $1;
+		$rest = $2;
+	    }
+	}
+	error(g_('symbol name unspecified: %s'), $symbolspec) if (!$symbol);
+    } else {
+	# No tag specification. Symbol name is up to the first space
+	# foobarsymbol@Base 1.0 1
+	if ($symbolspec =~ m/^(\S+)(.*)$/) {
+	    $symbol = $1;
+	    $rest = $2;
+	} else {
+	    return 0;
+	}
+    }
+    $self->{symbol} = $symbol;
+    $self->{symbol_templ} = $symbol_templ;
+    $self->{symbol_quoted} = $symbol_quoted if ($symbol_quoted);
+
+    # Now parse "the rest" (minver and dep_id)
+    if ($rest =~ /^\s(\S+)(?:\s(\d+))?/) {
+	$self->{minver} = $1;
+	$self->{dep_id} = $2 // 0;
+    } elsif (defined $opts{default_minver}) {
+	$self->{minver} = $opts{default_minver};
+	$self->{dep_id} = 0;
+    } else {
+	return 0;
+    }
+    return 1;
+}
+
+# A hook for symbol initialization (typically processing of tags). The code
+# here may even change symbol name. Called from
+# Dpkg::Shlibs::SymbolFile::create_symbol().
+sub initialize {
+    my $self = shift;
+
+    # Look for tags marking symbol patterns. The pattern may match multiple
+    # real symbols.
+    my $type;
+    if ($self->has_tag('c++')) {
+	# Raw symbol name is always demangled to the same alias while demangled
+	# symbol name cannot be reliably converted back to raw symbol name.
+	# Therefore, we can use hash for mapping.
+	$type = 'alias-c++';
+    }
+
+    # Support old style wildcard syntax. That's basically a symver
+    # with an optional tag.
+    if ($self->get_symbolname() =~ /^\*@(.*)$/) {
+	$self->add_tag('symver') unless $self->has_tag('symver');
+	$self->add_tag('optional') unless $self->has_tag('optional');
+	$self->{symbol} = $1;
+    }
+
+    if ($self->has_tag('symver')) {
+	# Each symbol is matched against its version rather than full
+	# name@version string.
+	$type = (defined $type) ? 'generic' : 'alias-symver';
+        if ($self->get_symbolname() =~ /@/) {
+            warning(g_('symver tag with versioned symbol will not match: %s'),
+                    $self->get_symbolspec(1));
+        }
+	if ($self->get_symbolname() eq 'Base') {
+	    error(g_("you can't use symver tag to catch unversioned symbols: %s"),
+	          $self->get_symbolspec(1));
+	}
+    }
+
+    # As soon as regex is involved, we need to match each real
+    # symbol against each pattern (aka 'generic' pattern).
+    if ($self->has_tag('regex')) {
+	$type = 'generic';
+	# Pre-compile regular expression for better performance.
+	my $regex = $self->get_symbolname();
+	$self->{pattern}{regex} = qr/$regex/;
+    }
+    if (defined $type) {
+	$self->init_pattern($type);
+    }
+}
+
+sub get_symbolname {
+    my $self = shift;
+
+    return $self->{symbol};
+}
+
+sub get_symboltempl {
+    my $self = shift;
+
+    return $self->{symbol_templ} || $self->{symbol};
+}
+
+sub set_symbolname {
+    my ($self, $name, $templ, $quoted) = @_;
+
+    $name //= $self->{symbol};
+    if (!defined $templ && $name =~ /\s/) {
+	$templ = $name;
+    }
+    if (!defined $quoted && defined $templ && $templ =~ /\s/) {
+	$quoted = '"';
+    }
+    $self->{symbol} = $name;
+    $self->{symbol_templ} = $templ;
+    if ($quoted) {
+	$self->{symbol_quoted} = $quoted;
+    } else {
+	delete $self->{symbol_quoted};
+    }
+}
+
+sub has_tags {
+    my $self = shift;
+    return scalar (@{$self->{tagorder}});
+}
+
+sub add_tag {
+    my ($self, $tagname, $tagval) = @_;
+    if (exists $self->{tags}{$tagname}) {
+	$self->{tags}{$tagname} = $tagval;
+	return 0;
+    } else {
+	$self->{tags}{$tagname} = $tagval;
+	push @{$self->{tagorder}}, $tagname;
+    }
+    return 1;
+}
+
+sub delete_tag {
+    my ($self, $tagname) = @_;
+    if (exists $self->{tags}{$tagname}) {
+	delete $self->{tags}{$tagname};
+        $self->{tagorder} = [ grep { $_ ne $tagname } @{$self->{tagorder}} ];
+	return 1;
+    }
+    return 0;
+}
+
+sub has_tag {
+    my ($self, $tag) = @_;
+    return exists $self->{tags}{$tag};
+}
+
+sub get_tag_value {
+    my ($self, $tag) = @_;
+    return $self->{tags}{$tag};
+}
+
+# Checks if the symbol is equal to another one (by name and optionally,
+# tag sets, versioning info (minver and depid))
+sub equals {
+    my ($self, $other, %opts) = @_;
+    $opts{versioning} //= 1;
+    $opts{tags} //= 1;
+
+    return 0 if $self->{symbol} ne $other->{symbol};
+
+    if ($opts{versioning}) {
+	return 0 if $self->{minver} ne $other->{minver};
+	return 0 if $self->{dep_id} ne $other->{dep_id};
+    }
+
+    if ($opts{tags}) {
+	return 0 if scalar(@{$self->{tagorder}}) != scalar(@{$other->{tagorder}});
+
+	for my $i (0 .. scalar(@{$self->{tagorder}}) - 1) {
+	    my $tag = $self->{tagorder}->[$i];
+	    return 0 if $tag ne $other->{tagorder}->[$i];
+	    if (defined $self->{tags}{$tag} && defined $other->{tags}{$tag}) {
+		return 0 if $self->{tags}{$tag} ne $other->{tags}{$tag};
+	    } elsif (defined $self->{tags}{$tag} || defined $other->{tags}{$tag}) {
+		return 0;
+	    }
+	}
+    }
+
+    return 1;
+}
+
+
+sub is_optional {
+    my $self = shift;
+    return $self->has_tag('optional');
+}
+
+sub is_arch_specific {
+    my $self = shift;
+    return $self->has_tag('arch');
+}
+
+sub arch_is_concerned {
+    my ($self, $arch) = @_;
+    my $arches = $self->{tags}{arch};
+
+    return 0 if defined $arch && defined $arches &&
+                !debarch_is_concerned($arch, split /[\s,]+/, $arches);
+
+    my ($bits, $endian) = debarch_to_abiattrs($arch);
+    return 0 if defined $bits && defined $self->{tags}{'arch-bits'} &&
+                $bits ne $self->{tags}{'arch-bits'};
+    return 0 if defined $endian && defined $self->{tags}{'arch-endian'} &&
+                $endian ne $self->{tags}{'arch-endian'};
+
+    return 1;
+}
+
+# Get reference to the pattern the symbol matches (if any)
+sub get_pattern {
+    my $self = shift;
+
+    return $self->{matching_pattern};
+}
+
+### NOTE: subroutines below require (or initialize) $self to be a pattern ###
+
+# Initializes this symbol as a pattern of the specified type.
+sub init_pattern {
+    my ($self, $type) = @_;
+
+    $self->{pattern}{type} = $type;
+    # To be filled with references to symbols matching this pattern.
+    $self->{pattern}{matches} = [];
+}
+
+# Is this symbol a pattern or not?
+sub is_pattern {
+    my $self = shift;
+
+    return exists $self->{pattern};
+}
+
+# Get pattern type if this symbol is a pattern.
+sub get_pattern_type {
+    my $self = shift;
+
+    return $self->{pattern}{type} // '';
+}
+
+# Get (sub)type of the alias pattern. Returns empty string if current
+# pattern is not alias.
+sub get_alias_type {
+    my $self = shift;
+
+    return ($self->get_pattern_type() =~ /^alias-(.+)/ && $1) || '';
+}
+
+# Get a list of symbols matching this pattern if this symbol is a pattern
+sub get_pattern_matches {
+    my $self = shift;
+
+    return @{$self->{pattern}{matches}};
+}
+
+# Create a new symbol based on the pattern (i.e. $self)
+# and add it to the pattern matches list.
+sub create_pattern_match {
+    my $self = shift;
+    return unless $self->is_pattern();
+
+    # Leave out 'pattern' subfield while deep-cloning
+    my $pattern_stuff = $self->{pattern};
+    delete $self->{pattern};
+    my $newsym = $self->clone(@_);
+    $self->{pattern} = $pattern_stuff;
+
+    # Clean up symbol name related internal fields
+    $newsym->set_symbolname();
+
+    # Set newsym pattern reference, add to pattern matches list
+    $newsym->{matching_pattern} = $self;
+    push @{$self->{pattern}{matches}}, $newsym;
+    return $newsym;
+}
+
+### END of pattern subroutines ###
+
+# Given a raw symbol name the call returns its alias according to the rules of
+# the current pattern ($self). Returns undef if the supplied raw name is not
+# transformable to alias.
+sub convert_to_alias {
+    my ($self, $rawname, $type) = @_;
+    $type = $self->get_alias_type() unless $type;
+
+    if ($type) {
+	if ($type eq 'symver') {
+	    # In case of symver, alias is symbol version. Extract it from the
+	    # rawname.
+	    return "$1" if ($rawname =~ /\@([^@]+)$/);
+	} elsif ($rawname =~ /^_Z/ && $type eq 'c++') {
+	    return cppfilt_demangle_cpp($rawname);
+	}
+    }
+    return;
+}
+
+sub get_tagspec {
+    my $self = shift;
+    if ($self->has_tags()) {
+	my @tags;
+	for my $tagname (@{$self->{tagorder}}) {
+	    my $tagval = $self->{tags}{$tagname};
+	    if (defined $tagval) {
+		push @tags, $tagname . '='  . $tagval;
+	    } else {
+		push @tags, $tagname;
+	    }
+	}
+	return '(' . join('|', @tags) . ')';
+    }
+    return '';
+}
+
+sub get_symbolspec {
+    my $self = shift;
+    my $template_mode = shift;
+    my $spec = '';
+    $spec .= "#MISSING: $self->{deprecated}#" if $self->{deprecated};
+    $spec .= ' ';
+    if ($template_mode) {
+	if ($self->has_tags()) {
+	    $spec .= sprintf('%s%3$s%s%3$s', $self->get_tagspec(),
+		$self->get_symboltempl(), $self->{symbol_quoted} // '');
+	} else {
+	    $spec .= $self->get_symboltempl();
+	}
+    } else {
+	$spec .= $self->get_symbolname();
+    }
+    $spec .= " $self->{minver}";
+    $spec .= " $self->{dep_id}" if $self->{dep_id};
+    return $spec;
+}
+
+# Sanitize the symbol when it is confirmed to be found in
+# the respective library.
+sub mark_found_in_library {
+    my ($self, $minver, $arch) = @_;
+
+    if ($self->{deprecated}) {
+	# Symbol reappeared somehow
+	$self->{deprecated} = 0;
+	$self->{minver} = $minver if (not $self->is_optional());
+    } else {
+	# We assume that the right dependency information is already
+	# there.
+	if (version_compare($minver, $self->{minver}) < 0) {
+	    $self->{minver} = $minver;
+	}
+    }
+    # Never remove arch tags from patterns
+    if (not $self->is_pattern()) {
+	if (not $self->arch_is_concerned($arch)) {
+	    # Remove arch tags because they are incorrect.
+	    $self->delete_tag('arch');
+	    $self->delete_tag('arch-bits');
+	    $self->delete_tag('arch-endian');
+	}
+    }
+}
+
+# Sanitize the symbol when it is confirmed to be NOT found in
+# the respective library.
+# Mark as deprecated those that are no more provided (only if the
+# minver is later than the version where the symbol was introduced)
+sub mark_not_found_in_library {
+    my ($self, $minver, $arch) = @_;
+
+    # Ignore symbols from foreign arch
+    return if not $self->arch_is_concerned($arch);
+
+    if ($self->{deprecated}) {
+	# Bump deprecated if the symbol is optional so that it
+	# keeps reappearing in the diff while it's missing
+	$self->{deprecated} = $minver if $self->is_optional();
+    } elsif (version_compare($minver, $self->{minver}) > 0) {
+	$self->{deprecated} = $minver;
+    }
+}
+
+# Checks if the symbol (or pattern) is legitimate as a real symbol for the
+# specified architecture.
+sub is_legitimate {
+    my ($self, $arch) = @_;
+    return ! $self->{deprecated} &&
+           $self->arch_is_concerned($arch);
+}
+
+# Determine whether a supplied raw symbol name matches against current ($self)
+# symbol or pattern.
+sub matches_rawname {
+    my ($self, $rawname) = @_;
+    my $target = $rawname;
+    my $ok = 1;
+    my $do_eq_match = 1;
+
+    if ($self->is_pattern()) {
+	# Process pattern tags in the order they were specified.
+	for my $tag (@{$self->{tagorder}}) {
+	    if (any { $tag eq $_ } ALIAS_TYPES) {
+		$ok = not not ($target = $self->convert_to_alias($target, $tag));
+	    } elsif ($tag eq 'regex') {
+		# Symbol name is a regex. Match it against the target
+		$do_eq_match = 0;
+		$ok = ($target =~ $self->{pattern}{regex});
+	    }
+	    last if not $ok;
+	}
+    }
+
+    # Equality match by default
+    if ($ok && $do_eq_match) {
+	$ok = $target eq $self->get_symbolname();
+    }
+    return $ok;
+}
+
+1;
diff --git a/scripts/Dpkg/Shlibs/SymbolFile.pm b/scripts/Dpkg/Shlibs/SymbolFile.pm
new file mode 100644
index 0000000..d492055
--- /dev/null
+++ b/scripts/Dpkg/Shlibs/SymbolFile.pm
@@ -0,0 +1,697 @@
+# Copyright © 2007 Raphaël Hertzog <hertzog@debian.org>
+# 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::SymbolFile;
+
+use strict;
+use warnings;
+
+our $VERSION = '0.01';
+
+use Dpkg::Gettext;
+use Dpkg::ErrorHandling;
+use Dpkg::Version;
+use Dpkg::Control::Fields;
+use Dpkg::Shlibs::Symbol;
+use Dpkg::Arch qw(get_host_arch);
+
+use parent qw(Dpkg::Interface::Storable);
+
+# Needed by the deprecated key, which is a correct use.
+no if $Dpkg::Version::VERSION ge '1.02',
+    warnings => qw(Dpkg::Version::semantic_change::overload::bool);
+
+my %internal_symbol = (
+    __bss_end__ => 1,                   # arm
+    __bss_end => 1,                     # arm
+    _bss_end__ => 1,                    # arm
+    __bss_start => 1,                   # ALL
+    __bss_start__ => 1,                 # arm
+    __data_start => 1,                  # arm
+    __do_global_ctors_aux => 1,         # ia64
+    __do_global_dtors_aux => 1,         # ia64
+    __do_jv_register_classes => 1,      # ia64
+    _DYNAMIC => 1,                      # ALL
+    _edata => 1,                        # ALL
+    _end => 1,                          # ALL
+    __end__ => 1,                       # arm
+    __exidx_end => 1,                   # armel
+    __exidx_start => 1,                 # armel
+    _fbss => 1,                         # mips, mipsel
+    _fdata => 1,                        # mips, mipsel
+    _fini => 1,                         # ALL
+    _ftext => 1,                        # mips, mipsel
+    _GLOBAL_OFFSET_TABLE_ => 1,         # hppa, mips, mipsel
+    __gmon_start__ => 1,                # hppa
+    __gnu_local_gp => 1,                # mips, mipsel
+    _gp => 1,                           # mips, mipsel
+    _init => 1,                         # ALL
+    _PROCEDURE_LINKAGE_TABLE_ => 1,     # sparc, alpha
+    _SDA2_BASE_ => 1,                   # powerpc
+    _SDA_BASE_ => 1,                    # powerpc
+);
+
+for my $i (14 .. 31) {
+    # Many powerpc specific symbols
+    $internal_symbol{"_restfpr_$i"} = 1;
+    $internal_symbol{"_restfpr_$i\_x"} = 1;
+    $internal_symbol{"_restgpr_$i"} = 1;
+    $internal_symbol{"_restgpr_$i\_x"} = 1;
+    $internal_symbol{"_savefpr_$i"} = 1;
+    $internal_symbol{"_savegpr_$i"} = 1;
+}
+
+sub symbol_is_internal {
+    my ($symbol, $include_groups) = @_;
+
+    return 1 if exists $internal_symbol{$symbol};
+
+    # The ARM Embedded ABI spec states symbols under this namespace as
+    # possibly appearing in output objects.
+    return 1 if not ${$include_groups}{aeabi} and $symbol =~ /^__aeabi_/;
+
+    # The GNU implementation of the OpenMP spec, specifies symbols under
+    # this namespace as possibly appearing in output objects.
+    return 1 if not ${$include_groups}{gomp}
+                and $symbol =~ /^\.gomp_critical_user_/;
+
+    return 0;
+}
+
+sub new {
+    my ($this, %opts) = @_;
+    my $class = ref($this) || $this;
+    my $self = \%opts;
+    bless $self, $class;
+    $self->{arch} //= get_host_arch();
+    $self->clear();
+    if (exists $self->{file}) {
+	$self->load($self->{file}) if -e $self->{file};
+    }
+    return $self;
+}
+
+sub get_arch {
+    my $self = shift;
+    return $self->{arch};
+}
+
+sub clear {
+    my $self = shift;
+    $self->{objects} = {};
+}
+
+sub clear_except {
+    my ($self, @ids) = @_;
+
+    my %has = map { $_ => 1 } @ids;
+    foreach my $objid (keys %{$self->{objects}}) {
+	delete $self->{objects}{$objid} unless exists $has{$objid};
+    }
+}
+
+sub get_sonames {
+    my $self = shift;
+    return keys %{$self->{objects}};
+}
+
+sub get_symbols {
+    my ($self, $soname) = @_;
+    if (defined $soname) {
+	my $obj = $self->get_object($soname);
+	return (defined $obj) ? values %{$obj->{syms}} : ();
+    } else {
+	my @syms;
+	foreach my $soname ($self->get_sonames()) {
+	    push @syms, $self->get_symbols($soname);
+	}
+	return @syms;
+    }
+}
+
+sub get_patterns {
+    my ($self, $soname) = @_;
+    my @patterns;
+    if (defined $soname) {
+	my $obj = $self->get_object($soname);
+	foreach my $alias (values %{$obj->{patterns}{aliases}}) {
+	    push @patterns, values %$alias;
+	}
+	return (@patterns, @{$obj->{patterns}{generic}});
+    } else {
+	foreach my $soname ($self->get_sonames()) {
+	    push @patterns, $self->get_patterns($soname);
+	}
+	return @patterns;
+    }
+}
+
+# Create a symbol from the supplied string specification.
+sub create_symbol {
+    my ($self, $spec, %opts) = @_;
+    my $symbol = (exists $opts{base}) ? $opts{base} :
+	Dpkg::Shlibs::Symbol->new();
+
+    my $ret = $opts{dummy} ? $symbol->parse_symbolspec($spec, default_minver => 0) :
+	$symbol->parse_symbolspec($spec);
+    if ($ret) {
+	$symbol->initialize(arch => $self->get_arch());
+	return $symbol;
+    }
+    return;
+}
+
+sub add_symbol {
+    my ($self, $symbol, $soname) = @_;
+    my $object = $self->get_object($soname);
+
+    if ($symbol->is_pattern()) {
+	if (my $alias_type = $symbol->get_alias_type()) {
+	    $object->{patterns}{aliases}{$alias_type} //= {};
+	    # Alias hash for matching.
+	    my $aliases = $object->{patterns}{aliases}{$alias_type};
+	    $aliases->{$symbol->get_symbolname()} = $symbol;
+	} else {
+	    # Otherwise assume this is a generic sequential pattern. This
+	    # should be always safe.
+	    push @{$object->{patterns}{generic}}, $symbol;
+	}
+	return 'pattern';
+    } else {
+	# invalidate the minimum version cache
+        $object->{minver_cache} = [];
+	$object->{syms}{$symbol->get_symbolname()} = $symbol;
+	return 'sym';
+    }
+}
+
+sub _new_symbol {
+    my $base = shift || 'Dpkg::Shlibs::Symbol';
+    return (ref $base) ? $base->clone(@_) : $base->new(@_);
+}
+
+# Option state is only used for recursive calls.
+sub parse {
+    my ($self, $fh, $file, %opts) = @_;
+    my $state = $opts{state} //= {};
+
+    if (exists $state->{seen}) {
+	return if exists $state->{seen}{$file}; # Avoid include loops
+    } else {
+	$self->{file} = $file;
+        $state->{seen} = {};
+    }
+    $state->{seen}{$file} = 1;
+
+    if (not ref $state->{obj_ref}) { # Init ref to name of current object/lib
+        ${$state->{obj_ref}} = undef;
+    }
+
+    while (<$fh>) {
+	chomp;
+
+	if (/^(?:\s+|#(?:DEPRECATED|MISSING): ([^#]+)#\s*)(.*)/) {
+	    if (not defined ${$state->{obj_ref}}) {
+		error(g_('symbol information must be preceded by a header (file %s, line %s)'), $file, $.);
+	    }
+	    # Symbol specification
+	    my $deprecated = ($1) ? Dpkg::Version->new($1) : 0;
+	    my $sym = _new_symbol($state->{base_symbol}, deprecated => $deprecated);
+	    if ($self->create_symbol($2, base => $sym)) {
+		$self->add_symbol($sym, ${$state->{obj_ref}});
+	    } else {
+		warning(g_('failed to parse line in %s: %s'), $file, $_);
+	    }
+	} elsif (/^(\(.*\))?#include\s+"([^"]+)"/) {
+	    my $tagspec = $1;
+	    my $filename = $2;
+	    my $dir = $file;
+	    my $old_base_symbol = $state->{base_symbol};
+	    my $new_base_symbol;
+	    if (defined $tagspec) {
+		$new_base_symbol = _new_symbol($old_base_symbol);
+		$new_base_symbol->parse_tagspec($tagspec);
+	    }
+	    $state->{base_symbol} = $new_base_symbol;
+	    $dir =~ s{[^/]+$}{}; # Strip filename
+	    $self->load("$dir$filename", %opts);
+	    $state->{base_symbol} = $old_base_symbol;
+	} elsif (/^#|^$/) {
+	    # Skip possible comments and empty lines
+	} elsif (/^\|\s*(.*)$/) {
+	    # Alternative dependency template
+	    push @{$self->{objects}{${$state->{obj_ref}}}{deps}}, "$1";
+	} elsif (/^\*\s*([^:]+):\s*(.*\S)\s*$/) {
+	    # Add meta-fields
+	    $self->{objects}{${$state->{obj_ref}}}{fields}{field_capitalize($1)} = $2;
+	} elsif (/^(\S+)\s+(.*)$/) {
+	    # New object and dependency template
+	    ${$state->{obj_ref}} = $1;
+	    if (exists $self->{objects}{${$state->{obj_ref}}}) {
+		# Update/override infos only
+		$self->{objects}{${$state->{obj_ref}}}{deps} = [ "$2" ];
+	    } else {
+		# Create a new object
+		$self->create_object(${$state->{obj_ref}}, "$2");
+	    }
+	} else {
+	    warning(g_('failed to parse a line in %s: %s'), $file, $_);
+	}
+    }
+    delete $state->{seen}{$file};
+}
+
+# Beware: we reuse the data structure of the provided symfile so make
+# sure to not modify them after having called this function
+sub merge_object_from_symfile {
+    my ($self, $src, $objid) = @_;
+    if (not $self->has_object($objid)) {
+        $self->{objects}{$objid} = $src->get_object($objid);
+    } else {
+        warning(g_('tried to merge the same object (%s) twice in a symfile'), $objid);
+    }
+}
+
+sub output {
+    my ($self, $fh, %opts) = @_;
+    $opts{template_mode} //= 0;
+    $opts{with_deprecated} //= 1;
+    $opts{with_pattern_matches} //= 0;
+    my $res = '';
+    foreach my $soname (sort $self->get_sonames()) {
+	my @deps = $self->get_dependencies($soname);
+	my $dep_first = shift @deps;
+	if (exists $opts{package} and not $opts{template_mode}) {
+	    $dep_first =~ s/#PACKAGE#/$opts{package}/g;
+	}
+	print { $fh } "$soname $dep_first\n" if defined $fh;
+	$res .= "$soname $dep_first\n" if defined wantarray;
+
+	foreach my $dep_next (@deps) {
+	    if (exists $opts{package} and not $opts{template_mode}) {
+	        $dep_next =~ s/#PACKAGE#/$opts{package}/g;
+	    }
+	    print { $fh } "| $dep_next\n" if defined $fh;
+	    $res .= "| $dep_next\n" if defined wantarray;
+	}
+	my $f = $self->{objects}{$soname}{fields};
+	foreach my $field (sort keys %{$f}) {
+	    my $value = $f->{$field};
+	    if (exists $opts{package} and not $opts{template_mode}) {
+	        $value =~ s/#PACKAGE#/$opts{package}/g;
+	    }
+	    print { $fh } "* $field: $value\n" if defined $fh;
+	    $res .= "* $field: $value\n" if defined wantarray;
+	}
+
+	my @symbols;
+	if ($opts{template_mode}) {
+	    # Exclude symbols matching a pattern, but include patterns themselves
+	    @symbols = grep { not $_->get_pattern() } $self->get_symbols($soname);
+	    push @symbols, $self->get_patterns($soname);
+	} else {
+	    @symbols = $self->get_symbols($soname);
+	}
+	foreach my $sym (sort { $a->get_symboltempl() cmp
+	                        $b->get_symboltempl() } @symbols) {
+	    next if $sym->{deprecated} and not $opts{with_deprecated};
+	    # Do not dump symbols from foreign arch unless dumping a template.
+	    next if not $opts{template_mode} and
+	            not $sym->arch_is_concerned($self->get_arch());
+	    # Dump symbol specification. Dump symbol tags only in template mode.
+	    print { $fh } $sym->get_symbolspec($opts{template_mode}), "\n" if defined $fh;
+	    $res .= $sym->get_symbolspec($opts{template_mode}) . "\n" if defined wantarray;
+	    # Dump pattern matches as comments (if requested)
+	    if ($opts{with_pattern_matches} && $sym->is_pattern()) {
+		for my $match (sort { $a->get_symboltempl() cmp
+		                      $b->get_symboltempl() } $sym->get_pattern_matches())
+		{
+		    print { $fh } '#MATCH:', $match->get_symbolspec(0), "\n" if defined $fh;
+		    $res .= '#MATCH:' . $match->get_symbolspec(0) . "\n" if defined wantarray;
+		}
+	    }
+	}
+    }
+    return $res;
+}
+
+# Tries to match a symbol name and/or version against the patterns defined.
+# Returns a pattern which matches (if any).
+sub find_matching_pattern {
+    my ($self, $refsym, $sonames, $inc_deprecated) = @_;
+    $inc_deprecated //= 0;
+    my $name = (ref $refsym) ? $refsym->get_symbolname() : $refsym;
+
+    my $pattern_ok = sub {
+	my $p = shift;
+	return defined $p && ($inc_deprecated || !$p->{deprecated}) &&
+	       $p->arch_is_concerned($self->get_arch());
+    };
+
+    foreach my $soname ((ref($sonames) eq 'ARRAY') ? @$sonames : $sonames) {
+	my $obj = $self->get_object($soname);
+	my ($type, $pattern);
+	next unless defined $obj;
+
+	my $all_aliases = $obj->{patterns}{aliases};
+	for my $type (Dpkg::Shlibs::Symbol::ALIAS_TYPES) {
+	    if (exists $all_aliases->{$type} && keys(%{$all_aliases->{$type}})) {
+		my $aliases = $all_aliases->{$type};
+		my $converter = $aliases->{(keys %$aliases)[0]};
+		if (my $alias = $converter->convert_to_alias($name)) {
+		    if ($alias && exists $aliases->{$alias}) {
+			$pattern = $aliases->{$alias};
+			last if $pattern_ok->($pattern);
+			$pattern = undef; # otherwise not found yet
+		    }
+		}
+	    }
+	}
+
+	# Now try generic patterns and use the first that matches
+	if (not defined $pattern) {
+	    for my $p (@{$obj->{patterns}{generic}}) {
+		if ($pattern_ok->($p) && $p->matches_rawname($name)) {
+		    $pattern = $p;
+		    last;
+		}
+	    }
+	}
+	if (defined $pattern) {
+	    return (wantarray) ?
+		( symbol => $pattern, soname => $soname ) : $pattern;
+	}
+    }
+    return;
+}
+
+# merge_symbols($object, $minver)
+# Needs $Objdump->get_object($soname) as parameter
+# Do not merge symbols found in the list of (arch-specific) internal symbols.
+sub merge_symbols {
+    my ($self, $object, $minver) = @_;
+
+    my $soname = $object->{SONAME};
+    error(g_('cannot merge symbols from objects without SONAME'))
+        unless $soname;
+
+    my %include_groups = ();
+    my $groups = $self->get_field($soname, 'Allow-Internal-Symbol-Groups');
+    if (not defined $groups) {
+        $groups = $self->get_field($soname, 'Ignore-Blacklist-Groups');
+        if (defined $groups) {
+            warnings::warnif('deprecated',
+                'symbols file field "Ignore-Blacklist-Groups" is deprecated, ' .
+                'use "Allow-Internal-Symbol-Groups" instead');
+        }
+    }
+    if (defined $groups) {
+        $include_groups{$_} = 1 foreach (split ' ', $groups);
+    }
+
+    my %dynsyms;
+    foreach my $sym ($object->get_exported_dynamic_symbols()) {
+        my $name = $sym->{name} . '@' .
+                   ($sym->{version} ? $sym->{version} : 'Base');
+        my $symobj = $self->lookup_symbol($name, $soname);
+        if (symbol_is_internal($sym->{name}, \%include_groups)) {
+            next unless defined $symobj;
+
+            if ($symobj->has_tag('allow-internal')) {
+                # Allow the symbol.
+            } elsif ($symobj->has_tag('ignore-blacklist')) {
+                # Allow the symbol and warn.
+                warnings::warnif('deprecated',
+                    'symbol tag "ignore-blacklist" is deprecated, ' .
+                    'use "allow-internal" instead');
+            } else {
+                # Ignore the symbol.
+                next;
+            }
+        }
+        $dynsyms{$name} = $sym;
+    }
+
+    unless ($self->has_object($soname)) {
+	$self->create_object($soname, '');
+    }
+    # Scan all symbols provided by the objects
+    my $obj = $self->get_object($soname);
+    # invalidate the minimum version cache - it is not sufficient to
+    # invalidate in add_symbol, since we might change a minimum
+    # version for a particular symbol without adding it
+    $obj->{minver_cache} = [];
+    foreach my $name (keys %dynsyms) {
+        my $sym;
+	if ($sym = $self->lookup_symbol($name, $obj, 1)) {
+	    # If the symbol is already listed in the file
+	    $sym->mark_found_in_library($minver, $self->get_arch());
+	} else {
+	    # The exact symbol is not present in the file, but it might match a
+	    # pattern.
+	    my $pattern = $self->find_matching_pattern($name, $obj, 1);
+	    if (defined $pattern) {
+		$pattern->mark_found_in_library($minver, $self->get_arch());
+		$sym = $pattern->create_pattern_match(symbol => $name);
+	    } else {
+		# Symbol without any special info as no pattern matched
+		$sym = Dpkg::Shlibs::Symbol->new(symbol => $name,
+		                                 minver => $minver);
+	    }
+	    $self->add_symbol($sym, $obj);
+	}
+    }
+
+    # Process all symbols which could not be found in the library.
+    foreach my $sym ($self->get_symbols($soname)) {
+	if (not exists $dynsyms{$sym->get_symbolname()}) {
+	    $sym->mark_not_found_in_library($minver, $self->get_arch());
+	}
+    }
+
+    # Deprecate patterns which didn't match anything
+    for my $pattern (grep { $_->get_pattern_matches() == 0 }
+                          $self->get_patterns($soname)) {
+	$pattern->mark_not_found_in_library($minver, $self->get_arch());
+    }
+}
+
+sub is_empty {
+    my $self = shift;
+    return scalar(keys %{$self->{objects}}) ? 0 : 1;
+}
+
+sub has_object {
+    my ($self, $soname) = @_;
+    return exists $self->{objects}{$soname};
+}
+
+sub get_object {
+    my ($self, $soname) = @_;
+    return ref($soname) ? $soname : $self->{objects}{$soname};
+}
+
+sub create_object {
+    my ($self, $soname, @deps) = @_;
+    $self->{objects}{$soname} = {
+	syms => {},
+	fields => {},
+	patterns => {
+	    aliases => {},
+	    generic => [],
+	},
+	deps => [ @deps ],
+        minver_cache => []
+    };
+}
+
+sub get_dependency {
+    my ($self, $soname, $dep_id) = @_;
+    $dep_id //= 0;
+    return $self->get_object($soname)->{deps}[$dep_id];
+}
+
+sub get_smallest_version {
+    my ($self, $soname, $dep_id) = @_;
+    $dep_id //= 0;
+    my $so_object = $self->get_object($soname);
+    return $so_object->{minver_cache}[$dep_id]
+        if defined $so_object->{minver_cache}[$dep_id];
+    my $minver;
+    foreach my $sym ($self->get_symbols($so_object)) {
+        next if $dep_id != $sym->{dep_id};
+        $minver //= $sym->{minver};
+        if (version_compare($minver, $sym->{minver}) > 0) {
+            $minver = $sym->{minver};
+        }
+    }
+    $so_object->{minver_cache}[$dep_id] = $minver;
+    return $minver;
+}
+
+sub get_dependencies {
+    my ($self, $soname) = @_;
+    return @{$self->get_object($soname)->{deps}};
+}
+
+sub get_field {
+    my ($self, $soname, $name) = @_;
+    if (my $obj = $self->get_object($soname)) {
+	if (exists $obj->{fields}{$name}) {
+	    return $obj->{fields}{$name};
+	}
+    }
+    return;
+}
+
+# Tries to find a symbol like the $refsym and returns its descriptor.
+# $refsym may also be a symbol name.
+sub lookup_symbol {
+    my ($self, $refsym, $sonames, $inc_deprecated) = @_;
+    $inc_deprecated //= 0;
+    my $name = (ref $refsym) ? $refsym->get_symbolname() : $refsym;
+
+    foreach my $so ((ref($sonames) eq 'ARRAY') ? @$sonames : $sonames) {
+	if (my $obj = $self->get_object($so)) {
+	    my $sym = $obj->{syms}{$name};
+	    if ($sym and ($inc_deprecated or not $sym->{deprecated}))
+	    {
+		return (wantarray) ?
+		    ( symbol => $sym, soname => $so ) : $sym;
+	    }
+	}
+    }
+    return;
+}
+
+# Tries to find a pattern like the $refpat and returns its descriptor.
+# $refpat may also be a pattern spec.
+sub lookup_pattern {
+    my ($self, $refpat, $sonames, $inc_deprecated) = @_;
+    $inc_deprecated //= 0;
+    # If $refsym is a string, we need to create a dummy ref symbol.
+    $refpat = $self->create_symbol($refpat, dummy => 1) if ! ref($refpat);
+
+    if ($refpat && $refpat->is_pattern()) {
+	foreach my $soname ((ref($sonames) eq 'ARRAY') ? @$sonames : $sonames) {
+	    if (my $obj = $self->get_object($soname)) {
+		my $pat;
+		if (my $type = $refpat->get_alias_type()) {
+		    if (exists $obj->{patterns}{aliases}{$type}) {
+			$pat = $obj->{patterns}{aliases}{$type}{$refpat->get_symbolname()};
+		    }
+		} elsif ($refpat->get_pattern_type() eq 'generic') {
+		    for my $p (@{$obj->{patterns}{generic}}) {
+			if (($inc_deprecated || !$p->{deprecated}) &&
+			    $p->equals($refpat, versioning => 0))
+			{
+			    $pat = $p;
+			    last;
+			}
+		    }
+		}
+		if ($pat && ($inc_deprecated || !$pat->{deprecated})) {
+		    return (wantarray) ?
+			(symbol => $pat, soname => $soname) : $pat;
+		}
+	    }
+	}
+    }
+    return;
+}
+
+# Get symbol object reference either by symbol name or by a reference object.
+sub get_symbol_object {
+    my ($self, $refsym, $soname) = @_;
+    my $sym = $self->lookup_symbol($refsym, $soname, 1);
+    if (! defined $sym) {
+	$sym = $self->lookup_pattern($refsym, $soname, 1);
+    }
+    return $sym;
+}
+
+sub get_new_symbols {
+    my ($self, $ref, %opts) = @_;
+    my $with_optional = (exists $opts{with_optional}) ?
+	$opts{with_optional} : 0;
+    my @res;
+    foreach my $soname ($self->get_sonames()) {
+	next if not $ref->has_object($soname);
+
+	# Scan raw symbols first.
+	foreach my $sym (grep { ($with_optional || ! $_->is_optional())
+	                        && $_->is_legitimate($self->get_arch()) }
+	                      $self->get_symbols($soname))
+	{
+	    my $refsym = $ref->lookup_symbol($sym, $soname, 1);
+	    my $isnew;
+	    if (defined $refsym) {
+		# If the symbol exists in the $ref symbol file, it might
+		# still be new if $refsym is not legitimate.
+		$isnew = not $refsym->is_legitimate($self->get_arch());
+	    } else {
+		# If the symbol does not exist in the $ref symbol file, it does
+		# not mean that it's new. It might still match a pattern in the
+		# symbol file. However, due to performance reasons, first check
+		# if the pattern that the symbol matches (if any) exists in the
+		# ref symbol file as well.
+		$isnew = not (
+		    ($sym->get_pattern() and $ref->lookup_pattern($sym->get_pattern(), $soname, 1)) or
+		    $ref->find_matching_pattern($sym, $soname, 1)
+		);
+	    }
+	    push @res, { symbol => $sym, soname => $soname } if $isnew;
+	}
+
+	# Now scan patterns
+	foreach my $p (grep { ($with_optional || ! $_->is_optional())
+	                      && $_->is_legitimate($self->get_arch()) }
+	                    $self->get_patterns($soname))
+	{
+	    my $refpat = $ref->lookup_pattern($p, $soname, 0);
+	    # If reference pattern was not found or it is not legitimate,
+	    # considering current one as new.
+	    if (not defined $refpat or
+	        not $refpat->is_legitimate($self->get_arch()))
+	    {
+		push @res, { symbol => $p , soname => $soname };
+	    }
+	}
+    }
+    return @res;
+}
+
+sub get_lost_symbols {
+    my ($self, $ref, %opts) = @_;
+    return $ref->get_new_symbols($self, %opts);
+}
+
+
+sub get_new_libs {
+    my ($self, $ref) = @_;
+    my @res;
+    foreach my $soname ($self->get_sonames()) {
+	push @res, $soname if not $ref->get_object($soname);
+    }
+    return @res;
+}
+
+sub get_lost_libs {
+    my ($self, $ref) = @_;
+    return $ref->get_new_libs($self);
+}
+
+1;