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+# 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/>.
+
+=encoding utf8
+
+=head1 NAME
+
+Dpkg::Shlibs::Objdump::Object - represent an object from objdump output
+
+=head1 DESCRIPTION
+
+This module provides a class to represent an object parsed from
+L<objdump(1)> output.
+
+B<Note>: This is a private module, its API can change at any time.
+
+=cut
+
+package Dpkg::Shlibs::Objdump::Object 0.01;
+
+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};
+}
+
+=head1 CHANGES
+
+=head2 Version 0.xx
+
+This is a private module.
+
+=cut
+
+1;