#!/usr/bin/perl

=head1 NAME

dh_shlibdeps - calculate shared library dependencies

=cut

use strict;
use warnings;
use Cwd;
use File::Find;
use Debian::Debhelper::Dh_Lib;

our $VERSION = DH_BUILTIN_VERSION;

=head1 SYNOPSIS

B<dh_shlibdeps> [S<I<debhelper options>>] [B<-L>I<package>] [B<-l>I<directory>] [B<-X>I<item>] [S<B<--> I<params>>]

=head1 DESCRIPTION

B<dh_shlibdeps> is a debhelper program that is responsible for calculating
shared library dependencies for packages.

This program is merely a wrapper around L<dpkg-shlibdeps(1)> that calls it
once for each package listed in the F<control> file, passing it
a list of ELF executables and shared libraries it has found.

=head1 OPTIONS

=over 4

=item B<-X>I<item>, B<--exclude=>I<item>

Exclude files that contain F<item> anywhere in their filename from being
passed to B<dpkg-shlibdeps>. This will make their dependencies be ignored.
This may be useful in some situations, but use it with caution. This option
may be used more than once to exclude more than one thing.

=item B<--> I<params>

Pass I<params> to L<dpkg-shlibdeps(1)>.

=item B<-u>I<params>, B<--dpkg-shlibdeps-params=>I<params>

This is another way to pass I<params> to L<dpkg-shlibdeps(1)>.
It is deprecated; use B<--> instead.

=item B<-l>I<directory>[B<:>I<directory> ...]

With recent versions of B<dpkg-shlibdeps>, this option is generally not
needed.

It tells B<dpkg-shlibdeps> (via its B<-l> parameter), to look for private
package libraries in the specified directory (or directories -- separate
with colons). With recent
versions of B<dpkg-shlibdeps>, this is mostly only useful for packages that
build multiple flavors of the same library, or other situations where
the library is installed into a directory not on the regular library search
path.

=item B<-L>I<package>, B<--libpackage=>I<package>

With recent versions of B<dpkg-shlibdeps>, this option is generally not
needed, unless your package builds multiple flavors of the same library
or is relying on F<debian/shlibs.local> for an internal library.

It tells B<dpkg-shlibdeps> (via its B<-S> parameter) to look first in the package
build directory for the specified package, when searching for libraries,
symbol files, and shlibs files.

If needed, this can be passed multiple times with different package
names.

=back

=head1 EXAMPLES

Suppose that your source package produces libfoo1, libfoo-dev, and
libfoo-bin binary packages. libfoo-bin links against libfoo1, and should
depend on it. In your rules file, first run B<dh_makeshlibs>, then B<dh_shlibdeps>:

	dh_makeshlibs
	dh_shlibdeps

This will have the effect of generating automatically a shlibs file for
libfoo1, and using that file and the libfoo1 library in the
F<debian/libfoo1/usr/lib> directory to calculate shared library dependency
information.

If a libbar1 package is also produced, that is an alternate build of
libfoo, and is installed into F</usr/lib/bar/>, you can make libfoo-bin depend
on libbar1 as follows:

	dh_shlibdeps -Llibbar1 -l/usr/lib/bar
	
=cut

init(options => {
	"L|libpackage=s@" => \$dh{LIBPACKAGE},
	"dpkg-shlibdeps-params=s" => \$dh{U_PARAMS},
	"l=s" => \$dh{L_PARAMS},
});

if (defined $dh{V_FLAG}) {
	warning("You probably wanted to pass -V to dh_makeshlibs, it has no effect on dh_shlibdeps");
}

on_pkgs_in_parallel {
	foreach my $package (@_) {
		my $tmp=tmpdir($package);
		my $ext=pkgext($package);
		my (@filelist);

		# Generate a list of ELF binaries in the package, ignoring any
		# we were told to exclude.
		my $find_options='';
		if (defined($dh{EXCLUDE_FIND}) && $dh{EXCLUDE_FIND} ne '') {
			$find_options="! \\( $dh{EXCLUDE_FIND} \\)";
		}
		next if not -d $tmp;
		if (compat(10)) {
			foreach my $file (split(/\n/, `find $tmp -type f \\( -perm /111 -or -name "*.so*" -or -name "*.cmxs" -or -name "*.node" \\) $find_options -print`)) {
				# Prune directories that contain separated debug symbols.
				# CAVEAT: There are files in /usr/lib/debug that are not detached debug symbols,
				# which should be processed.  (see #865982)
				next if $file =~ m!^\Q$tmp\E/usr/lib/debug/(lib|lib64|usr|bin|sbin|opt|dev|emul|\.build-id)/!;
				# TODO this is slow, optimize. Ie, file can run once on
				# multiple files..
				my $ff = qx_cmd('file', '-e', 'apptype', '-e', 'ascii', '-e', 'encoding',
					'-e', 'cdf', '-e', 'compress', '-e', 'tar', $file);
				if ($ff =~ m/ELF/ && $ff !~ /statically linked/) {
					push @filelist, $file;
				}
			}
		} else {
			my $find_elf_files = sub {
				my $fn = $_;
				return if -l $fn; # Ignore symlinks
				# See if we were asked to exclude this file.
				# Note that we have to test on the full filename, including directory.
				if (excludefile($fn)) {
					$File::Find::prune = 1 if -d _;
					return;
				}
				if (-d _) {
					# Prune directories that contain separated debug symbols.
					# CAVEAT: There are files in /usr/lib/debug that are not detached debug symbols,
					# which should be processed.  (see #865982)
					if ($fn =~ m!^\Q$tmp\E/usr/lib/debug/(lib|lib64|usr|bin|sbin|opt|dev|emul|\.build-id)/!) {
						$File::Find::prune = 1;
					}
					return;
				}

				return if not -f _;
				return if not is_so_or_exec_elf_file($fn);
				# TODO this is slow, optimize. Ie, file can run once on
				# multiple files..
				my $ff = qx_cmd('file', '-e', 'apptype', '-e', 'ascii', '-e', 'encoding',
					'-e', 'cdf', '-e', 'compress', '-e', 'tar', $fn);
				if ($ff =~ m/ELF/ && $ff !~ /statically linked/) {
					push(@filelist, $fn);
				}
			};
			find({
					wanted => $find_elf_files,
					no_chdir => 1,
			}, $tmp);
		}

		if (@filelist) {
			my @opts;

			# dpkg-shlibdeps expects this directory to exist
			install_dir("$tmp/DEBIAN");

			if (defined($dh{LIBPACKAGE})) {
				@opts = map { '-S' . tmpdir($_) } @{$dh{LIBPACKAGE}};
			}

			push @opts, "-tudeb" if is_udeb($package);

			if ($dh{L_PARAMS}) {
				foreach (split(/:/, $dh{L_PARAMS})) {
					# Force the path absolute.
					my $libdir = m:^/: ? $_ : "/$_";
					push @opts, "-l$libdir";
				}
			}

			doit("dpkg-shlibdeps","-Tdebian/${ext}substvars",
				@opts,@{$dh{U_PARAMS}},@filelist);
		}
	}
};

=head1 SEE ALSO

L<debhelper(7)>, L<dpkg-shlibdeps(1)>

This program is a part of debhelper.

=head1 AUTHOR

Joey Hess <joeyh@debian.org>

=cut