5 dh_strip - strip executables, shared libraries, and some static libraries
11 use Debian::Debhelper::Dh_Lib;
15 B<dh_strip> [S<I<debhelper options>>] [B<-X>I<item>] [--dbg-package=package] [--keep-debug]
19 dh_strip is a debhelper program that is responsible for stripping
20 executables, shared libraries, and static libraries that are not used for
23 This program examines your package build directories and works out what
24 to strip on its own. It uses L<file(1)> and file permissions and filenames
25 to figure out what files are shared libraries (*.so), executable binaries,
26 and static (lib*.a) and debugging libraries (lib*_g.a, debug/*.so), and
27 strips each as much as is possible. (Which is not at all for debugging
28 libraries.) In general it seems to make very good guesses, and will do the
29 right thing in almost all cases.
31 Since it is very hard to automatically guess if a file is a
32 module, and hard to determine how to strip a module, dh_strip does not
33 currently deal with stripping binary modules such as .o files.
39 =item B<-X>I<item>, B<--exclude=>I<item>
41 Exclude files that contain "item" anywhere in their filename from being
42 stripped. You may use this option multiple times to build up a list of
45 =item B<--dbg-package=>I<package>
47 Causes dh_strip to save debug symbols stripped from the packages it acts on
48 as independent files in the package build directory of the specified debugging
51 For example, if your packages are libfoo and foo and you want to include a
52 foo-dbg package with debugging symbols, use dh_strip --dbg-package=foo-dbg.
54 Note that this option behaves significantly different in debhelper
55 compatibility levels 4 and below. Instead of specifying the name of a debug
56 package to put symbols in, it specifies a package (or packages) which
57 should have separated debug symbols, and the separated symbols are placed
58 in packages with "-dbg" added to their name.
60 =item B<-k>, B<--keep-debug>
62 Debug symbols will be retained, but split into an independent
63 file in usr/lib/debug/ in the package build directory. --dbg-package
64 is easier to use than this option, but this option is more flexible.
70 If the DEB_BUILD_OPTIONS environment variable contains "nostrip", nothing
71 will be stripped, in accordance with Debian policy (section 10.1
76 Debian policy, version 3.0.1
82 # This variable can be used to turn off stripping (see Policy).
83 if (defined $ENV{DEB_BUILD_OPTIONS} && $ENV{DEB_BUILD_OPTIONS} =~ /nostrip/) {
87 # I could just use `file $_[0]`, but this is safer
90 open (FILE, '-|') # handle all filenames safely
91 || exec('file', $file)
92 || die "can't exec file: $!";
98 # Check if a file is an elf binary, shared library, or static library,
99 # for use by File::Find. It'll fill the following 3 arrays with anything
101 my (@shared_libs, @executables, @static_libs);
103 return if -l $_ or -d $_; # Skip directories and symlinks always.
105 # See if we were asked to exclude this file.
106 # Note that we have to test on the full filename, including directory.
107 my $fn="$File::Find::dir/$_";
108 foreach my $f (@{$dh{EXCLUDE}}) {
109 return if ($fn=~m/\Q$f\E/);
112 # Is it a debug library in a debug subdir?
113 return if $fn=~m/debug\/.*\.so/;
115 # Does its filename look like a shared library?
117 # Ok, do the expensive test.
118 my $type=get_file_type($_);
119 if ($type=~m/.*ELF.*shared.*/) {
120 push @shared_libs, $fn;
125 # Is it executable? -x isn't good enough, so we need to use stat.
126 my (undef,undef,$mode,undef)=stat(_);
128 # Ok, expensive test.
129 my $type=get_file_type($_);
130 if ($type=~m/.*ELF.*(executable|shared).*/) {
131 push @executables, $fn;
136 # Is it a static library, and not a debug library?
137 if (m/lib.*\.a$/ && ! m/.*_g\.a$/) {
138 # Is it a binary file, or something else (maybe a liner
139 # script on Hurd, for example? I don't use file, because
140 # file returns a varity of things on static libraries.
142 push @static_libs, $fn;
153 # Don't try to copy debug symbols out if the file is already
155 return unless get_file_type($file) =~ /not stripped/;
157 my ($base_file)=$file=~/^\Q$tmp\E(.*)/;
158 my $debug_path=$desttmp."/usr/lib/debug/".$base_file;
159 my $debug_dir=dirname($debug_path);
160 if (! -d $debug_dir) {
161 doit("install", "-d", $debug_dir);
163 doit("objcopy", "--only-keep-debug", $file, $debug_path);
164 # No reason for this to be executable.
165 doit("chmod", 644, $debug_path);
171 my $debug_path=shift;
172 doit("objcopy", "--add-gnu-debuglink", $debug_path, $file);
175 foreach my $package (@{$dh{DOPACKAGES}}) {
176 my $tmp=tmpdir($package);
178 # Support for keeping the debugging symbols in a detached file.
179 my $keep_debug=$dh{K_FLAG};
182 if (ref $dh{DEBUGPACKAGES}) {
184 # Note that it's only an array for the v4 stuff;
185 # for v5 only one value is used.
186 my $debugpackage=@{$dh{DEBUGPACKAGES}}[0];
187 if (! grep { $_ eq $debugpackage } getpackages()) {
188 error("debug package $debugpackage is not listed in the control file");
190 $debugtmp=tmpdir($debugpackage);
194 if (ref $dh{DEBUGPACKAGES} && grep { $_ eq $package } @{$dh{DEBUGPACKAGES}}) {
196 $debugtmp=tmpdir($package."-dbg");
200 @shared_libs=@executables=@static_libs=();
201 find(\&testfile,$tmp);
203 foreach (@shared_libs) {
204 my $debug_path = make_debug($_, $tmp, $debugtmp) if $keep_debug;
205 # Note that all calls to strip on shared libs
206 # *must* inclde the --strip-unneeded.
207 doit("strip","--remove-section=.comment",
208 "--remove-section=.note","--strip-unneeded",$_);
209 attach_debug($_, $debug_path) if defined $debug_path;
212 foreach (@executables) {
213 my $debug_path = make_debug($_, $tmp, $debugtmp) if $keep_debug;
214 doit("strip","--remove-section=.comment",
215 "--remove-section=.note",$_);
216 attach_debug($_, $debug_path) if defined $debug_path;
219 foreach (@static_libs) {
220 doit("strip","--strip-debug",$_);
228 This program is a part of debhelper.
232 Joey Hess <joeyh@debian.org>