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>] [B<--dbg-package=>I<package>] [B<--keep-debug>]
19 B<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 (F<*.so>), executable binaries,
26 and static (F<lib*.a>) and debugging libraries (F<lib*_g.a>, F<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, B<dh_strip> does not
33 currently deal with stripping binary modules such as F<.o> files.
39 =item B<-X>I<item>, B<--exclude=>I<item>
41 Exclude files that contain I<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 B<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 I<foo-dbg> package with debugging symbols, use B<dh_strip --dbg-package=>I<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 B<-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 F<usr/lib/debug/> in the package build directory. B<--dbg-package>
64 is easier to use than this option, but this option is more flexible.
70 If the B<DEB_BUILD_OPTIONS> environment variable contains B<nostrip>, nothing
71 will be stripped, in accordance with Debian policy (section 10.1
76 Debian policy, version 3.0.1
81 "keep-debug" => \$dh{K_FLAG},
84 # This variable can be used to turn off stripping (see Policy).
85 if (defined $ENV{DEB_BUILD_OPTIONS} && $ENV{DEB_BUILD_OPTIONS} =~ /nostrip/) {
89 my $objcopy = cross_command("objcopy");
90 my $strip = cross_command("strip");
92 # I could just use `file $_[0]`, but this is safer
95 open (FILE, '-|') # handle all filenames safely
96 || exec('file', $file)
97 || die "can't exec file: $!";
103 # Check if a file is an elf binary, shared library, or static library,
104 # for use by File::Find. It'll fill the following 3 arrays with anything
106 my (@shared_libs, @executables, @static_libs);
108 return if -l $_ or -d $_; # Skip directories and symlinks always.
110 # See if we were asked to exclude this file.
111 # Note that we have to test on the full filename, including directory.
112 my $fn="$File::Find::dir/$_";
113 foreach my $f (@{$dh{EXCLUDE}}) {
114 return if ($fn=~m/\Q$f\E/);
117 # Is it a debug library in a debug subdir?
118 return if $fn=~m/debug\/.*\.so/;
120 # Does its filename look like a shared library?
121 # (*.cmxs are OCaml native code shared libraries)
122 if (m/.*\.(so.*?|cmxs$)/) {
123 # Ok, do the expensive test.
124 my $type=get_file_type($_);
125 if ($type=~m/.*ELF.*shared.*/) {
126 push @shared_libs, $fn;
131 # Is it executable? -x isn't good enough, so we need to use stat.
132 my (undef,undef,$mode,undef)=stat(_);
134 # Ok, expensive test.
135 my $type=get_file_type($_);
136 if ($type=~m/.*ELF.*(executable|shared).*/) {
137 push @executables, $fn;
142 # Is it a static library, and not a debug library?
143 if (m/lib.*\.a$/ && ! m/.*_g\.a$/) {
144 # Is it a binary file, or something else (maybe a liner
145 # script on Hurd, for example? I don't use file, because
146 # file returns a variety of things on static libraries.
148 push @static_libs, $fn;
159 # Don't try to copy debug symbols out if the file is already
161 return unless get_file_type($file) =~ /not stripped/;
163 my ($base_file)=$file=~/^\Q$tmp\E(.*)/;
164 my $debug_path=$desttmp."/usr/lib/debug/".$base_file;
165 my $debug_dir=dirname($debug_path);
166 if (! -d $debug_dir) {
167 doit("install", "-d", $debug_dir);
169 doit($objcopy, "--only-keep-debug", $file, $debug_path);
170 # No reason for this to be executable.
171 doit("chmod", 644, $debug_path);
177 my $debug_path=shift;
178 doit($objcopy, "--add-gnu-debuglink", $debug_path, $file);
181 foreach my $package (@{$dh{DOPACKAGES}}) {
182 my $tmp=tmpdir($package);
184 # Support for keeping the debugging symbols in a detached file.
185 my $keep_debug=$dh{K_FLAG};
188 if (ref $dh{DEBUGPACKAGES}) {
190 # Note that it's only an array for the v4 stuff;
191 # for v5 only one value is used.
192 my $debugpackage=@{$dh{DEBUGPACKAGES}}[0];
193 if (! grep { $_ eq $debugpackage } getpackages()) {
194 error("debug package $debugpackage is not listed in the control file");
196 $debugtmp=tmpdir($debugpackage);
200 if (ref $dh{DEBUGPACKAGES} && grep { $_ eq $package } @{$dh{DEBUGPACKAGES}}) {
202 $debugtmp=tmpdir($package."-dbg");
206 @shared_libs=@executables=@static_libs=();
207 find(\&testfile,$tmp);
209 foreach (@shared_libs) {
210 my $debug_path = make_debug($_, $tmp, $debugtmp) if $keep_debug;
211 # Note that all calls to strip on shared libs
212 # *must* inclde the --strip-unneeded.
213 doit($strip,"--remove-section=.comment",
214 "--remove-section=.note","--strip-unneeded",$_);
215 attach_debug($_, $debug_path) if defined $debug_path;
218 foreach (@executables) {
219 my $debug_path = make_debug($_, $tmp, $debugtmp) if $keep_debug;
220 doit($strip,"--remove-section=.comment",
221 "--remove-section=.note",$_);
222 attach_debug($_, $debug_path) if defined $debug_path;
225 foreach (@static_libs) {
226 doit($strip,"--strip-debug",$_);
234 This program is a part of debhelper.
238 Joey Hess <joeyh@debian.org>