This file is indexed.

/usr/bin/dpkg-gensymbols is in dpkg-dev 1.17.27.

This file is owned by root:root, with mode 0o755.

The actual contents of the file can be viewed below.

  1
  2
  3
  4
  5
  6
  7
  8
  9
 10
 11
 12
 13
 14
 15
 16
 17
 18
 19
 20
 21
 22
 23
 24
 25
 26
 27
 28
 29
 30
 31
 32
 33
 34
 35
 36
 37
 38
 39
 40
 41
 42
 43
 44
 45
 46
 47
 48
 49
 50
 51
 52
 53
 54
 55
 56
 57
 58
 59
 60
 61
 62
 63
 64
 65
 66
 67
 68
 69
 70
 71
 72
 73
 74
 75
 76
 77
 78
 79
 80
 81
 82
 83
 84
 85
 86
 87
 88
 89
 90
 91
 92
 93
 94
 95
 96
 97
 98
 99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
#!/usr/bin/perl
#
# dpkg-gensymbols
#
# Copyright © 2007 Raphaël Hertzog
# Copyright © 2007-2013 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/>.

use strict;
use warnings;

use Dpkg ();
use Dpkg::Arch qw(get_host_arch);
use Dpkg::Package;
use Dpkg::Shlibs qw(get_library_paths);
use Dpkg::Shlibs::Objdump;
use Dpkg::Shlibs::SymbolFile;
use Dpkg::Gettext;
use Dpkg::ErrorHandling;
use Dpkg::Control::Info;
use Dpkg::Changelog::Parse;
use Dpkg::Path qw(check_files_are_the_same find_command);

textdomain('dpkg-dev');

my $packagebuilddir = 'debian/tmp';

my $sourceversion;
my $stdout;
my $oppackage;
my $compare = 1; # Bail on missing symbols by default
my $quiet = 0;
my $input;
my $output;
my $template_mode = 0; # non-template mode by default
my $verbose_output = 0;
my $debug = 0;
my $host_arch = get_host_arch();

sub version {
    printf _g("Debian %s version %s.\n"), $Dpkg::PROGNAME, $Dpkg::PROGVERSION;

    printf _g('
This is free software; see the GNU General Public License version 2 or
later for copying conditions. There is NO warranty.
');
}

sub usage {
    printf _g(
'Usage: %s [<option>...]')
    . "\n\n" . _g(
'Options:
  -p<package>              generate symbols file for package.
  -P<package-build-dir>    temporary build dir instead of debian/tmp.
  -e<library>              explicitly list libraries to scan.
  -v<version>              version of the packages (defaults to
                           version extracted from debian/changelog).
  -c<level>                compare generated symbols file with the reference
                           template in the debian directory and fail if
                           difference is too important; level goes from 0 for
                           no check, to 4 for all checks (default level is 1).
  -q                       keep quiet and never emit any warnings or
                           generate a diff between generated symbols
                           file and the reference template.
  -I<file>                 force usage of <file> as reference symbols
                           file instead of the default file.
  -O[<file>]               write to stdout (or <file>), not .../DEBIAN/symbols.
  -t                       write in template mode (tags are not
                           processed and included in output).
  -V                       verbose output; write deprecated symbols and pattern
                           matching symbols as comments (in template mode only).
  -a<arch>                 assume <arch> as host architecture when processing
                           symbol files.
  -d                       display debug information during work.
  -?, --help               show this help message.
      --version            show the version.
'), $Dpkg::PROGNAME;
}

my @files;
while (@ARGV) {
    $_ = shift(@ARGV);
    if (m/^-p/p) {
	$oppackage = ${^POSTMATCH};
	my $err = pkg_name_is_illegal($oppackage);
	error(_g("illegal package name '%s': %s"), $oppackage, $err) if $err;
    } elsif (m/^-c(\d)?$/) {
	$compare = $1 // 1;
    } elsif (m/^-q$/) {
	$quiet = 1;
    } elsif (m/^-d$/) {
	$debug = 1;
    } elsif (m/^-v(.+)$/) {
	$sourceversion = $1;
    } elsif (m/^-e(.+)$/) {
	my $file = $1;
	if (-e $file) {
	    push @files, $file;
	} else {
	    my @to_add = glob($file);
	    push @files, @to_add;
	    warning(_g("pattern '%s' did not match any file"), $file)
		unless scalar(@to_add);
	}
    } elsif (m/^-P(.+)$/) {
	$packagebuilddir = $1;
	$packagebuilddir =~ s{/+$}{};
    } elsif (m/^-O$/) {
	$stdout = 1;
    } elsif (m/^-I(.+)$/) {
	$input = $1;
    } elsif (m/^-O(.+)$/) {
	$output = $1;
    } elsif (m/^-t$/) {
	$template_mode = 1;
    } elsif (m/^-V$/) {
	$verbose_output = 1;
    } elsif (m/^-a(.+)$/) {
	$host_arch = $1;
    } elsif (m/^-(?:\?|-help)$/) {
	usage();
	exit(0);
    } elsif (m/^--version$/) {
	version();
	exit(0);
    } else {
	usageerr(_g("unknown option \`%s'"), $_);
    }
}

umask 0022; # ensure sane default permissions for created files

if (exists $ENV{DPKG_GENSYMBOLS_CHECK_LEVEL}) {
    $compare = $ENV{DPKG_GENSYMBOLS_CHECK_LEVEL};
}

if (not defined($sourceversion)) {
    my $changelog = changelog_parse();
    $sourceversion = $changelog->{'Version'};
}
if (not defined($oppackage)) {
    my $control = Dpkg::Control::Info->new();
    my @packages = map { $_->{'Package'} } $control->get_packages();
    if (@packages == 0) {
	error(_g('no package stanza found in control info'));
    } elsif (@packages > 1) {
	error(_g('must specify package since control info has many (%s)'),
	      "@packages");
    }
    $oppackage = $packages[0];
}

my $symfile = Dpkg::Shlibs::SymbolFile->new(arch => $host_arch);
my $ref_symfile = Dpkg::Shlibs::SymbolFile->new(arch => $host_arch);
# Load source-provided symbol information
foreach my $file ($input, $output, "debian/$oppackage.symbols.$host_arch",
    "debian/symbols.$host_arch", "debian/$oppackage.symbols",
    'debian/symbols')
{
    if (defined $file and -e $file) {
	print "Using references symbols from $file\n" if $debug;
	$symfile->load($file);
	$ref_symfile->load($file) if $compare || ! $quiet;
	last;
    }
}

# Scan package build dir looking for libraries
if (not scalar @files) {
    PATH: foreach my $path (get_library_paths()) {
	my $libdir = "$packagebuilddir$path";
	$libdir =~ s{/+}{/}g;
	lstat $libdir;
	next if not -d _;
	next if -l _; # Skip directories which are symlinks
        # Skip any directory _below_ a symlink as well
        my $updir = $libdir;
        while (($updir =~ s{/[^/]*$}{}) and
               not check_files_are_the_same($packagebuilddir, $updir)) {
            next PATH if -l $updir;
        }
	opendir(my $libdir_dh, "$libdir")
	    or syserr(_g("can't read directory %s: %s"), $libdir, $!);
	push @files, grep {
	    /(\.so\.|\.so$)/ && -f &&
	    Dpkg::Shlibs::Objdump::is_elf($_);
	} map { "$libdir/$_" } readdir($libdir_dh);
	closedir $libdir_dh;
    }
}

# Merge symbol information
my $od = Dpkg::Shlibs::Objdump->new();
foreach my $file (@files) {
    print "Scanning $file for symbol information\n" if $debug;
    my $objid = $od->analyze($file);
    unless (defined($objid) && $objid) {
	warning(_g("Dpkg::Shlibs::Objdump couldn't parse %s\n"), $file);
	next;
    }
    my $object = $od->get_object($objid);
    if ($object->{SONAME}) { # Objects without soname are of no interest
	print "Merging symbols from $file as $object->{SONAME}\n" if $debug;
	if (not $symfile->has_object($object->{SONAME})) {
	    $symfile->create_object($object->{SONAME}, "$oppackage #MINVER#");
	}
	$symfile->merge_symbols($object, $sourceversion);
    } else {
	print "File $file doesn't have a soname. Ignoring.\n" if $debug;
    }
}
$symfile->clear_except(keys %{$od->{objects}});

# Write out symbols files
if ($stdout) {
    $output = _g('<standard output>');
    $symfile->output(\*STDOUT, package => $oppackage,
                     template_mode => $template_mode,
                     with_pattern_matches => $verbose_output,
                     with_deprecated => $verbose_output);
} else {
    unless (defined($output)) {
	unless ($symfile->is_empty()) {
	    $output = "$packagebuilddir/DEBIAN/symbols";
	    mkdir("$packagebuilddir/DEBIAN") if not -e "$packagebuilddir/DEBIAN";
	}
    }
    if (defined($output)) {
	print "Storing symbols in $output.\n" if $debug;
	$symfile->save($output, package => $oppackage,
	               template_mode => $template_mode,
	               with_pattern_matches => $verbose_output,
	               with_deprecated => $verbose_output);
    } else {
	print "No symbol information to store.\n" if $debug;
    }
}

# Check if generated files differs from reference file
my $exitcode = 0;
if ($compare || ! $quiet) {
    # Compare
    if (my @libs = $symfile->get_new_libs($ref_symfile)) {
	warning(_g('new libraries appeared in the symbols file: %s'), "@libs")
	    unless $quiet;
	$exitcode = 4 if ($compare >= 4);
    }
    if (my @libs = $symfile->get_lost_libs($ref_symfile)) {
	warning(_g('some libraries disappeared in the symbols file: %s'), "@libs")
	    unless $quiet;
	$exitcode = 3 if ($compare >= 3);
    }
    if ($symfile->get_new_symbols($ref_symfile)) {
	warning(_g('some new symbols appeared in the symbols file: %s'),
		_g('see diff output below')) unless $quiet;
	$exitcode = 2 if ($compare >= 2);
    }
    if ($symfile->get_lost_symbols($ref_symfile)) {
	warning(_g('some symbols or patterns disappeared in the symbols file: %s'),
	        _g('see diff output below')) unless $quiet;
	$exitcode = 1 if ($compare >= 1);
    }
}

unless ($quiet) {
    require File::Temp;
    require Digest::MD5;
    # Compare template symbols files before and after
    my $before = File::Temp->new(TEMPLATE=>'dpkg-gensymbolsXXXXXX');
    my $after = File::Temp->new(TEMPLATE=>'dpkg-gensymbolsXXXXXX');
    $ref_symfile->output($before, package => $oppackage, template_mode => 1);
    $symfile->output($after, package => $oppackage, template_mode => 1);
    seek($before, 0, 0); seek($after, 0, 0);
    my ($md5_before, $md5_after) = (Digest::MD5->new(), Digest::MD5->new());
    $md5_before->addfile($before);
    $md5_after->addfile($after);
    # Output diffs between symbols files if any
    if ($md5_before->hexdigest() ne $md5_after->hexdigest()) {
	if (not defined($output)) {
	    warning(_g('the generated symbols file is empty'));
	} elsif (defined($ref_symfile->{file})) {
	    warning(_g("%s doesn't match completely %s"),
		    $output, $ref_symfile->{file});
	} else {
	    warning(_g('no debian/symbols file used as basis for generating %s'),
		    $output);
	}
	my ($a, $b) = ($before->filename, $after->filename);
	my $diff_label = sprintf('%s (%s_%s_%s)',
	($ref_symfile->{file}) ? $ref_symfile->{file} : 'new_symbol_file',
	$oppackage, $sourceversion, $host_arch);
	system('diff', '-u', '-L', $diff_label, $a, $b) if find_command('diff');
    }
}
exit($exitcode);