9 files changed, 804 insertions, 5 deletions

diff --git a/Debian/Debhelper/Buildsystem.pm b/Debian/Debhelper/Buildsystem.pm
new file mode 100644
index 00000000..5bebfe2e
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem.pm
@@ -0,0 +1,257 @@
+# Defines debhelper buildsystem class interface and implementation
+# of common functionality.
+#
+# Copyright: © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem;
+
+use strict;
+use warnings;
+use Cwd;
+use File::Spec;
+use Debian::Debhelper::Dh_Lib;
+
+# Cache DEB_BUILD_GNU_TYPE value. Performance hit of multiple
+# invocations is noticable when listing buildsystems.
+our $DEB_BUILD_GNU_TYPE = dpkg_architecture_value("DEB_BUILD_GNU_TYPE");
+
+# Build system name. Defaults to the last component of the class
+# name. Do not override this method unless you know what you are
+# doing.
+sub NAME {
+	my $this=shift;
+	my $class = ref($this) || $this;
+	if ($class =~ m/^.+::([^:]+)$/) {
+		return $1;
+	}
+	else {
+		error("ınvalid buildsystem class name: $class");
+	}
+}
+
+# Description of the build system to be shown to the users.
+sub DESCRIPTION {
+	error("class lacking a DESCRIPTION");
+}
+
+# Default build directory. Can be overriden in the derived
+# class if really needed.
+sub DEFAULT_BUILD_DIRECTORY {
+	"obj-" . $DEB_BUILD_GNU_TYPE;
+}
+
+# Constructs a new build system object. Named parameters:
+# - builddir -     specifies build directory to use. If not specified,
+#                  in-source build will be performed. If undef or empty,
+#                  DEFAULT_BUILD_DIRECTORY will be used.
+# - build_action - set this parameter to the name of the build action
+#                  if you want the object to determine its is_buidable
+#                  status automatically (with check_auto_buildable()).
+#                  Do not pass this parameter if is_buildable flag should
+#                  be forced to true or set this parameter to undef if
+#                  is_buildable flag should be false.
+# Derived class can override the constructor to initialize common object
+# parameters and execute commands to configure build environment if
+# is_buildable flag is set on the object.
+sub new {
+	my ($class, %opts)=@_;
+
+	my $this = bless({ builddir => undef, is_buildable => 1 }, $class);
+	if (exists $opts{builddir}) {
+		if ($opts{builddir}) {
+			$this->{builddir} = $opts{builddir};
+		}
+		else {
+			$this->{builddir} = $this->DEFAULT_BUILD_DIRECTORY();
+		}
+	}
+	if (exists $opts{build_action}) {
+		if (defined $opts{build_action}) {
+			$this->{is_buildable} = $this->check_auto_buildable($opts{build_action});
+		}
+		else {
+			$this->{is_buildable} = 0;
+		}
+	}
+	return $this;
+}
+
+# Test is_buildable flag of the object.
+sub is_buildable {
+	my $this=shift;
+	return $this->{is_buildable};
+}
+
+# This instance method is called to check if the build system is capable
+# to auto build a source package. Additional argument $action describes
+# which operation the caller is going to perform (either configure,
+# build, test, install or clean). You must override this method for the
+# build system module to be ever picked up automatically. This method is
+# used in conjuction with @Dh_Buildsystems::BUILDSYSTEMS.
+#
+# This method is supposed to be called with source root directory being
+# working directory. Use $this->get_buildpath($path) method to get full
+# path to the files in the build directory.
+sub check_auto_buildable {
+	my $this=shift;
+	my ($action) = @_;
+	return 0;
+}
+
+# Derived class can call this method in its constructor
+# to enforce in-source building even if the user requested otherwise.
+sub enforce_in_source_building {
+	my $this=shift;
+	if ($this->{builddir}) {
+		# Do not emit warning unless the object is buildable.
+		if ($this->is_buildable()) {
+			warning("warning: " . $this->NAME() .
+			    " does not support building outside-source. In-source build enforced.");
+		}
+		$this->{builddir} = undef;
+	}
+}
+
+# Derived class can call this method in its constructor to enforce
+# outside-source building even if the user didn't request it.
+sub enforce_outside_source_building {
+	my ($this, $builddir) = @_;
+	if (!defined $this->{builddir}) {
+		$this->{builddir} = ($builddir && $builddir ne ".") ? $builddir : $this->DEFAULT_BUILD_DIRECTORY();
+	}
+}
+
+# Get path to the specified build directory
+sub get_builddir {
+	my $this=shift;
+	return $this->{builddir};
+}
+
+# Construct absolute path to the file from the given path that is relative
+# to the build directory.
+sub get_buildpath {
+	my ($this, $path) = @_;
+	if ($this->get_builddir()) {
+		return File::Spec->catfile($this->get_builddir(), $path);
+	}
+	else {
+		return File::Spec->catfile('.', $path);
+	}
+}
+
+# When given a relative path in the source tree, converts it
+# to the path that is relative to the build directory.
+# If $path is not given, returns relative path to the root of the
+# source tree from the build directory.
+sub get_rel2builddir_path {
+	my $this=shift;
+	my $path=shift;
+
+	if (defined $path) {
+		$path = File::Spec->catfile(Cwd::getcwd(), $path);
+	}
+	else {
+		$path = Cwd::getcwd();
+	}
+	if ($this->get_builddir()) {
+		return File::Spec->abs2rel($path, Cwd::abs_path($this->get_builddir()));
+	}
+	return $path;
+}
+
+# Creates a build directory.
+sub mkdir_builddir {
+	my $this=shift;
+	if ($this->get_builddir()) {
+		doit("mkdir", "-p", $this->get_builddir());
+	}
+}
+
+sub _cd {
+	my ($this, $dir)=@_;
+	if (! $dh{NO_ACT}) {
+		verbose_print("cd $dir");
+		chdir $dir or error("error: unable to chdir to $dir");
+	}
+}
+
+# Changes working directory the build directory (if needed), calls doit(@_)
+# and changes working directory back to the source directory.
+sub doit_in_builddir {
+	my $this=shift;
+	if ($this->get_builddir()) {
+		my $builddir = $this->get_builddir();
+		my $sourcedir = $this->get_rel2builddir_path();
+		$this->_cd($builddir);
+		doit(@_);
+		$this->_cd($sourcedir);
+	}
+	else {
+		doit(@_);
+	}
+	return 1;
+}
+
+# In case of outside-source tree building, whole build directory
+# gets wiped (if it exists) and 1 is returned. Otherwise, nothing
+# is done and 0 is returned.
+sub clean_builddir {
+	my $this=shift;
+	if ($this->get_builddir()) {
+		if (-d $this->get_builddir()) {
+			doit("rm", "-rf", $this->get_builddir());
+		}
+		return 1;
+	}
+	return 0;
+}
+
+
+# Instance method that is called before performing any action (see below).
+# Action name is passed as an argument. Derived classes overriding this
+# method should also call SUPER implementation of it.
+sub pre_action {
+	my $this=shift;
+	my ($action)=@_;
+}
+
+# Instance method that is called after performing any action (see below).
+# Action name is passed as an argument. Derived classes overriding this
+# method should also call SUPER implementation of it.
+sub post_action {
+	my $this=shift;
+	my ($action)=@_;
+}
+
+# The instance methods below provide support for configuring,
+# building, testing, install and cleaning source packages.
+# In case of failure, the method may just error() out.
+#
+# These methods should be overriden by derived classes to
+# implement buildsystem specific actions needed to build the
+# source. Arbitary number of custom action arguments might be
+# passed. Default implementations do nothing.
+sub configure {
+	my $this=shift;
+}
+
+sub build {
+	my $this=shift;
+}
+
+sub test {
+	my $this=shift;
+}
+
+# destdir parameter specifies where to install files.
+sub install {
+	my $this=shift;
+	my $destdir=shift;
+}
+
+sub clean {
+	my $this=shift;
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/autoconf.pm b/Debian/Debhelper/Buildsystem/autoconf.pm
new file mode 100644
index 00000000..fcdc2567
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/autoconf.pm
@@ -0,0 +1,56 @@
+# A buildsystem plugin for handling autoconf based projects
+#
+# Copyright: © 2008 Joey Hess
+#            © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::autoconf;
+
+use strict;
+use File::Spec;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem::makefile';
+
+sub DESCRIPTION {
+	"GNU Autoconf (configure)"
+}
+
+sub check_auto_buildable {
+	my $this=shift;
+	my ($action)=@_;
+
+	# Handle configure; the rest - next class
+	if ($action eq "configure") {
+		return -x "configure";
+	}
+	return 0;
+}
+
+sub configure {
+	my $this=shift;
+
+	# Standard set of options for configure.
+	my @opts;
+	push @opts, "--build=" . dpkg_architecture_value("DEB_BUILD_GNU_TYPE");
+	push @opts, "--prefix=/usr";
+	push @opts, "--includedir=\${prefix}/include";
+	push @opts, "--mandir=\${prefix}/share/man";
+	push @opts, "--infodir=\${prefix}/share/info";
+	push @opts, "--sysconfdir=/etc";
+	push @opts, "--localstatedir=/var";
+	push @opts, "--libexecdir=\${prefix}/lib/" . sourcepackage();
+	push @opts, "--disable-maintainer-mode";
+	push @opts, "--disable-dependency-tracking";
+	# Provide --host only if different from --build, as recommended in
+	# autotools-dev README.Debian: When provided (even if equal)
+	# autoconf 2.52+ switches to cross-compiling mode.
+	if (dpkg_architecture_value("DEB_BUILD_GNU_TYPE")
+	    ne dpkg_architecture_value("DEB_HOST_GNU_TYPE")) {
+		push @opts, "--host=" . dpkg_architecture_value("DEB_HOST_GNU_TYPE");
+	}
+
+	$this->mkdir_builddir();
+	$this->doit_in_builddir($this->get_rel2builddir_path("configure"), @opts, @_);
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/cmake.pm b/Debian/Debhelper/Buildsystem/cmake.pm
new file mode 100644
index 00000000..8bdbabbb
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/cmake.pm
@@ -0,0 +1,49 @@
+# A buildsystem plugin for handling CMake based projects.
+# It enforces outside-source building.
+#
+# Copyright: © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::cmake;
+
+use strict;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem::makefile';
+
+sub DESCRIPTION {
+	"CMake (CMakeLists.txt)"
+}
+
+sub check_auto_buildable {
+	my $this=shift;
+	my ($action)=@_;
+	my $ret = -e "CMakeLists.txt";
+	$ret &&= $this->SUPER::check_auto_buildable(@_) if $action ne "configure";
+	return $ret;
+}
+
+sub new {
+	my $class=shift;
+	my $this=$class->SUPER::new(@_);
+	# Enforce outside-source tree builds.
+	$this->enforce_outside_source_building();
+	return $this;
+}
+
+sub configure {
+	my $this=shift;
+	my @flags;
+
+	# Standard set of cmake flags
+	push @flags, "-DCMAKE_INSTALL_PREFIX=/usr";
+	push @flags, "-DCMAKE_C_FLAGS=$ENV{CFLAGS}" if (exists $ENV{CFLAGS});
+	push @flags, "-DCMAKE_CXX_FLAGS=$ENV{CXXFLAGS}" if (exists $ENV{CXXFLAGS});
+	push @flags, "-DCMAKE_LD_FLAGS=$ENV{LDFLAGS}" if (exists $ENV{LDFLAGS});
+	push @flags, "-DCMAKE_SKIP_RPATH=ON";
+	push @flags, "-DCMAKE_VERBOSE_MAKEFILE=ON";
+
+	$this->mkdir_builddir();
+	$this->doit_in_builddir("cmake", $this->get_rel2builddir_path(), @flags);
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/makefile.pm b/Debian/Debhelper/Buildsystem/makefile.pm
new file mode 100644
index 00000000..244ef30d
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/makefile.pm
@@ -0,0 +1,94 @@
+# A buildsystem plugin for handling simple Makefile based projects.
+#
+# Copyright: © 2008 Joey Hess
+#            © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::makefile;
+
+use strict;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem';
+
+sub get_makecmd_C {
+	my $this=shift;
+	if ($this->get_builddir()) {
+		return $this->{makecmd} . " -C " . $this->get_builddir();
+	}
+	return $this->{makecmd};
+}
+
+sub exists_make_target {
+	my ($this, $target) = @_;
+	my $makecmd=$this->get_makecmd_C();
+
+	# Use make -n to check to see if the target would do
+	# anything. There's no good way to test if a target exists.
+	my $ret=`$makecmd -s -n $target 2>/dev/null`;
+	chomp $ret;
+	return length($ret);
+}
+
+sub make_first_existing_target {
+	my $this=shift;
+	my $targets=shift;
+
+	foreach my $target (@$targets) {
+		if ($this->exists_make_target($target)) {
+			$this->doit_in_builddir($this->{makecmd}, $target, @_);
+			return $target;
+		}
+	}
+	return undef;
+}
+
+sub DESCRIPTION {
+	"simple Makefile"
+}
+
+sub new {
+	my $class=shift;
+	my $this=$class->SUPER::new(@_);
+	$this->{makecmd} = (exists $ENV{MAKE}) ? $ENV{MAKE} : "make";
+	return $this;
+}
+
+sub check_auto_buildable {
+	my $this=shift;
+	my ($action) = @_;
+
+	# Handles build, test, install, clean; configure - next class
+	if (grep /^\Q$action\E$/, qw{build test install clean}) {
+		# This is always called in the source directory, but generally
+		# Makefiles are created (or live) in the the build directory.
+		return -e $this->get_buildpath("Makefile") ||
+		       -e $this->get_buildpath("makefile") ||
+		       -e $this->get_buildpath("GNUmakefile");
+	}
+	return 0;
+}
+
+sub build {
+	my $this=shift;
+	$this->doit_in_builddir($this->{makecmd}, @_);
+}
+
+sub test {
+	my $this=shift;
+	$this->make_first_existing_target(['test', 'check'], @_);
+}
+
+sub install {
+	my $this=shift;
+	my $destdir=shift;
+	$this->make_first_existing_target(['install'], "DESTDIR=$destdir", @_);
+}
+
+sub clean {
+	my $this=shift;
+	if (!$this->clean_builddir()) {
+		$this->make_first_existing_target(['distclean', 'realclean', 'clean'], @_);
+	}
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/perl_build.pm b/Debian/Debhelper/Buildsystem/perl_build.pm
new file mode 100644
index 00000000..ce69f4ce
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/perl_build.pm
@@ -0,0 +1,68 @@
+# A buildsystem plugin for handling Perl Build based projects.
+#
+# Copyright: © 2008-2009 Joey Hess
+#            © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::perl_build;
+
+use strict;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem';
+
+sub DESCRIPTION {
+	"Perl Module::Build (Build.PL)"
+}
+
+sub check_auto_buildable {
+	my ($this, $action) = @_;
+
+	# Handles everything
+	my $ret = -e "Build.PL";
+	if ($action ne "configure") {
+		$ret &&= -e "Build";
+	}
+	return $ret;
+}
+
+sub do_perl {
+	my $this=shift;
+	$ENV{MODULEBUILDRC} = "/dev/null";
+	doit("perl", @_);
+}
+
+sub new {
+	my $class=shift;
+	my $this= $class->SUPER::new(@_);
+	$this->enforce_in_source_building();
+	return $this;
+}
+
+sub configure {
+	my $this=shift;
+	$ENV{PERL_MM_USE_DEFAULT}=1;
+	$this->do_perl("Build.PL", "installdirs=vendor", @_);
+}
+
+sub build {
+	my $this=shift;
+	$this->do_perl("Build", @_);
+}
+
+sub test {
+	my $this=shift;
+	$this->do_perl("Build", "test", @_);
+}
+
+sub install {
+	my $this=shift;
+	my $destdir=shift;
+	$this->do_perl("Build", "install", "destdir=$destdir", "create_packlist=0", @_);
+}
+
+sub clean {
+	my $this=shift;
+	$this->do_perl("Build", "--allow_mb_mismatch", 1, "distclean", @_);
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/perl_makemaker.pm b/Debian/Debhelper/Buildsystem/perl_makemaker.pm
new file mode 100644
index 00000000..c62041fe
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/perl_makemaker.pm
@@ -0,0 +1,53 @@
+# A buildsystem plugin for handling Perl MakeMaker based projects.
+#
+# Copyright: © 2008-2009 Joey Hess
+#            © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::perl_makemaker;
+
+use strict;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem::makefile';
+
+sub DESCRIPTION {
+	"Perl ExtUtils::MakeMaker (Makefile.PL)"
+}
+
+sub check_auto_buildable {
+	my $this=shift;
+	my ($action)=@_;
+
+	# Handles configure, install; the rest - next class
+	if ($action eq "install" || $action eq "configure") {
+		return -e "Makefile.PL";
+	}
+	else {
+		return 0;
+	}
+}
+
+sub new {
+	my $class=shift;
+	my $this=$class->SUPER::new(@_);
+	$this->enforce_in_source_building();
+	return $this;
+}
+
+sub configure {
+	my $this=shift;
+	# If set to a true value then MakeMaker's prompt function will
+	# # always return the default without waiting for user input.
+	$ENV{PERL_MM_USE_DEFAULT}=1;
+	doit("perl", "Makefile.PL", "INSTALLDIRS=vendor",
+		"create_packlist=0", "--skipdeps",
+		@_);
+}
+
+sub install {
+	my $this=shift;
+	my $destdir=shift;
+	$this->SUPER::install($destdir, "PREFIX=/usr", @_);
+}
+
+1;
diff --git a/Debian/Debhelper/Buildsystem/python_distutils.pm b/Debian/Debhelper/Buildsystem/python_distutils.pm
new file mode 100644
index 00000000..01a8c14e
--- /dev/null
+++ b/Debian/Debhelper/Buildsystem/python_distutils.pm
@@ -0,0 +1,51 @@
+# A buildsystem plugin for building Python Distutils based
+# projects.
+#
+# Copyright: © 2008 Joey Hess
+#            © 2008-2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Buildsystem::python_distutils;
+
+use strict;
+use Debian::Debhelper::Dh_Lib;
+use base 'Debian::Debhelper::Buildsystem';
+
+sub DESCRIPTION {
+	"Python distutils"
+}
+
+sub check_auto_buildable {
+	return -e "setup.py";
+}
+
+sub setup_py {
+	my $this=shift;
+	my $act=shift;
+
+	if ($this->get_builddir()) {
+		unshift @_, "--build-base=" . $this->get_builddir();
+	}
+	doit("python", "setup.py", $act, @_);
+}
+
+sub build {
+	my $this=shift;
+	$this->setup_py("build", @_);
+}
+
+sub install {
+	my $this=shift;
+	my $destdir=shift;
+	$this->setup_py("install", "--root=$destdir", "--no-compile", "-O0", @_);
+}
+
+sub clean {
+	my $this=shift;
+	$this->setup_py("clean", "-a", @_);
+	# The setup.py might import files, leading to python creating pyc
+	# files.
+	doit('find', '.', '-name', '*.pyc', '-exec', 'rm', '{}', ';');
+}
+
+1;
diff --git a/Debian/Debhelper/Dh_Buildsystems.pm b/Debian/Debhelper/Dh_Buildsystems.pm
new file mode 100644
index 00000000..afb03dd7
--- /dev/null
+++ b/Debian/Debhelper/Dh_Buildsystems.pm
@@ -0,0 +1,147 @@
+# A module for loading and managing debhelper buildsystem plugins.
+# This module is intended to be used by all dh_auto_* helper commands.
+#
+# Copyright: © 2009 Modestas Vainius
+# License: GPL-2+
+
+package Debian::Debhelper::Dh_Buildsystems;
+
+use strict;
+use warnings;
+use Debian::Debhelper::Dh_Lib;
+
+use base 'Exporter';
+our @EXPORT=qw(&buildsystems_init &buildsystems_do &load_buildsystem);
+
+# Historical order must be kept for backwards compatibility. New
+# buildsystems MUST be added to the END of the list.
+our @BUILDSYSTEMS = (
+    "autoconf",
+    "perl_makemaker",
+    "makefile",
+    "python_distutils",
+    "perl_build",
+    "cmake",
+);
+
+my $opt_buildsys;
+my $opt_builddir;
+my $opt_list;
+
+sub create_buildsystem_instance {
+	my $system=shift;
+	my %bsopts=@_;
+	my $module = "Debian::Debhelper::Buildsystem::$system";
+
+	eval "use $module";
+	if ($@) {
+		error("unable to load buildsystem class '$system': $@");
+	}
+
+	if (!exists $bsopts{builddir} && defined $opt_builddir) {
+		$bsopts{builddir} = ($opt_builddir eq "") ? undef : $opt_builddir;
+	}
+	return $module->new(%bsopts);
+}
+
+sub load_buildsystem {
+	my ($action, $system)=@_;
+	if (defined $system) {
+		my $inst = create_buildsystem_instance($system);
+		return $inst;
+	}
+	else {
+		# Try to determine build system automatically
+		for $system (@BUILDSYSTEMS) {
+			my $inst = create_buildsystem_instance($system, build_action=>$action);
+			if ($inst->is_buildable()) {
+				return $inst;
+			}
+		}
+	}
+	return;
+}
+
+sub buildsystems_init {
+	my %args=@_;
+
+	# TODO: Not documented in the manual pages yet.
+	# Initialize options from environment variables
+	if (exists $ENV{DH_AUTO_BUILDDIRECTORY}) {
+		$opt_builddir = $ENV{DH_AUTO_BUILDDIRECTORY};
+	}
+	if (exists $ENV{DH_AUTO_BUILDSYSTEM}) {
+		$opt_buildsys = $ENV{DH_AUTO_BUILDSYSTEM};
+	}
+
+	# Available command line options
+	my %options = (
+	    "b:s" => \$opt_builddir,
+	    "builddirectory:s" => \$opt_builddir,
+
+	    "m=s" => \$opt_buildsys,
+	    "buildsystem=s" => \$opt_buildsys,
+
+	    "l" => \$opt_list,
+	    "--list" => \$opt_list,
+	);
+	map { $args{options}{$_} = $options{$_} } keys(%options);
+	Debian::Debhelper::Dh_Lib::init(%args);
+}
+
+sub buildsystems_list {
+	my $action=shift;
+
+	# List buildsystems (including auto and specified status)
+	my ($auto, $specified);
+	for my $system (@BUILDSYSTEMS) {
+		my $inst = create_buildsystem_instance($system, build_action => undef);
+		my $is_specified = defined $opt_buildsys && $opt_buildsys eq $inst->NAME();
+		if (! defined $specified && defined $opt_buildsys && $opt_buildsys eq $inst->NAME()) {
+			$specified = $inst->NAME();
+		}
+		elsif (! defined $auto && $inst->check_auto_buildable($action)) {
+			$auto = $inst->NAME();
+		}
+		printf("%s - %s\n", $inst->NAME(), $inst->DESCRIPTION());
+	}
+	# List a specified 3rd party buildsystem too.
+	if (! defined $specified && defined $opt_buildsys) {
+		my $inst = create_buildsystem_instance($opt_buildsys, build_action => undef);
+		printf("%s - %s.\n", $inst->NAME(), $inst->DESCRIPTION());
+		$specified = $inst->NAME();
+	}
+	print "\n";
+	print "Auto-selected: $auto\n" if defined $auto;
+	print "Specified: $specified\n" if defined $specified;
+	print "No system auto-selected or specified\n"
+		if ! defined $auto && ! defined $specified;
+}
+
+sub buildsystems_do {
+	my $action=shift;
+
+	if (!defined $action) {
+		$action = basename($0);
+		$action =~ s/^dh_auto_//;
+	}
+
+	if (grep(/^\Q$action\E$/, qw{configure build test install clean}) == 0) {
+		error("unrecognized build action: " . $action);
+	}
+
+	if ($opt_list) {
+		buildsystems_list($action);
+		exit 0;
+	}
+
+	my $buildsystem = load_buildsystem($action, $opt_buildsys);
+	if (defined $buildsystem) {
+		$buildsystem->pre_action($action);
+		$buildsystem->$action(@_, @{$dh{U_PARAMS}});
+		$buildsystem->post_action($action);
+	}
+	return 0;
+}
+
+1;
diff --git a/Debian/Debhelper/Dh_Lib.pm b/Debian/Debhelper/Dh_Lib.pm
index 829eabfc..c80389d7 100644
--- a/Debian/Debhelper/Dh_Lib.pm
+++ b/Debian/Debhelper/Dh_Lib.pm
@@ -15,7 +15,8 @@ use vars qw(@ISA @EXPORT %dh);
 	    &filedoublearray &getpackages &basename &dirname &xargs %dh
 	    &compat &addsubstvar &delsubstvar &excludefile &package_arch
 	    &is_udeb &udeb_filename &debhelper_script_subst &escape_shell
-	    &inhibit_log &load_log &write_log);
+	    &inhibit_log &load_log &write_log &dpkg_architecture_value
+	    &sourcepackage);
 
 my $max_compat=7;
 
@@ -601,15 +602,21 @@ sub excludefile {
         return 0;
 }
 
+sub dpkg_architecture_value {
+	my $var = shift;
+	my $value=`dpkg-architecture -q$var 2>/dev/null` || error("dpkg-architecture failed");
+	chomp $value;
+	return $value;
+}
+
 # Returns the build architecture. (Memoized)
 {
 	my $arch;
 	
 	sub buildarch {
-  		return $arch if defined $arch;
-
-		$arch=`dpkg-architecture -qDEB_HOST_ARCH 2>/dev/null` || error("dpkg-architecture failed");
-		chomp $arch;
+		if (!defined $arch) {
+		    $arch=dpkg_architecture_value('DEB_HOST_ARCH');
+		}
 		return $arch;
 	}
 }
@@ -626,6 +633,23 @@ sub samearch {
 	return 0;
 }
 
+# Returns source package name
+sub sourcepackage {
+	open (CONTROL, 'debian/control') ||
+	    error("cannot read debian/control: $!\n");
+	while (<CONTROL>) {
+		chomp;
+		s/\s+$//;
+		if (/^Source:\s*(.*)/) {
+			close CONTROL;
+			return $1;
+		}
+	}
+
+	close CONTROL;
+	error("could not find Source: line in control file.");
+}
+
 # Returns a list of packages in the control file.
 # Must pass "arch" or "indep" or "same" to specify arch-dependant or
 # -independant or same arch packages. If nothing is specified, returns all