debian/changelog

-debhelper (11.1.7) UNRELEASED; urgency=medium
+debhelper (11.2) UNRELEASED; urgency=medium
 
   [ Niels Thykier ]
   * debhelper.7: Add a ~ to the suggested Build-Depends to ensure
@@ -10,6 +10,15 @@ debhelper (11.1.7) UNRELEASED; urgency=medium
   * Dh_Lib.pm: Fix bug that make debhelper trip on packages with
     the version "0".  Thanks to Chris Lamb for reporting the bug
     plus debugging the issue.  (Closes: #894895)
+  * Buildsystem.pm: Rewrite to support build systems that generate
+    build files for another build system (without using
+    inheritenece).  This enables generator build systems to have
+    multiple backends.
+  * cmake.pm: Support ninja as alternative backend (by using the
+    build system cmake+ninja).  Thanks to Kyle Edwards for the
+    suggestion.  (Closes: #895044)
+  * meson.pm: Rewrite as a generator build system with ninja as
+    the only backend.
 
   [ Nicolas Boulenguez ]
   * dh_installxfonts: Fix typo that causes a misc:Depends on

lib/Debian/Debhelper/Buildsystem.pm

@@ -11,15 +11,26 @@ use warnings;
 use Cwd ();
 use File::Spec;
 use Debian::Debhelper::Dh_Lib;
+use Debian::Debhelper::Dh_Buildsystems qw(load_buildsystem);
 
 # 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) || $this;
+	my ($this) = @_;
+	my $class = ref($this);
+	my $target_name;
+	if ($class) {
+		if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+			$target_name = $this->{'targetbuildsystem'}->NAME;
+		}
+	} else {
+		$class = $this;
+	}
 	if ($class =~ m/^.+::([^:]+)$/) {
-		return $1;
+		my $name = $1;
+		return "${name}+${target_name}" if defined($target_name);
+		return $name;
 	}
 	else {
 		error("ınvalid build system class name: $class");
@@ -37,6 +48,43 @@ sub DEFAULT_BUILD_DIRECTORY {
 	"obj-" . dpkg_architecture_value("DEB_HOST_GNU_TYPE");
 }
 
+# Return 1 if the build system generator
+sub IS_GENERATOR_BUILD_SYSTEM {
+	return 0;
+}
+
+# Generator build-systems only
+# The name of the supported target systems.  The first one is
+# assumed to be the default if DEFAULT_TARGET_BUILD_SYSTEM is
+# not overridden.
+sub SUPPORTED_TARGET_BUILD_SYSTEMS {
+	error("class lacking SUPPORTED_TARGET_BUILD_SYSTEMS");
+}
+
+# Generator build-systems only
+# Name of default target build system if target is unspecified
+#  (e.g. --buildsystem=cmake instead of cmake+makefile).
+sub DEFAULT_TARGET_BUILD_SYSTEM {
+	my ($this) = @_;
+	my @targets = $this->SUPPORTED_TARGET_BUILD_SYSTEMS;
+	# Assume they are listed in order.
+	return $targets[0];
+}
+
+# For regular build systems, the same as DESCRIPTION
+# For generator based build systems, the DESCRIPTION of the generator build
+# system + the target build system.  Do not override this method unless you
+# know what you are doing.
+sub FULL_DESCRIPTION {
+	my ($this) = @_;
+	my $description = $this->DESCRIPTION;
+	return $description if not exists($this->{'targetbuildsystem'});
+	my $target_build_system = $this->{'targetbuildsystem'};
+	return $description if not defined($target_build_system);
+	my $target_desc = $target_build_system->FULL_DESCRIPTION;
+	return "${description} combined with ${target_desc}";
+}
+
 # Constructs a new build system object. Named parameters:
 # - sourcedir-     specifies source directory (relative to the current (top)
 #                  directory) where the sources to be built live. If not
@@ -46,6 +94,8 @@ sub DEFAULT_BUILD_DIRECTORY {
 #                  DEFAULT_BUILD_DIRECTORY directory will be used.
 # - parallel -     max number of parallel processes to be spawned for building
 #                  sources (-1 = unlimited; 1 = no parallel)
+# - targetbuildsystem -     The target build system for generator based build
+#                           systems.  Only set for generator build systems.
 # Derived class can override the constructor to initialize common object
 # parameters. Do NOT use constructor to execute commands or otherwise
 # configure/setup build environment. There is absolutely no guarantee the
@@ -58,6 +108,7 @@ sub new {
 	                   builddir => undef,
 	                   parallel => undef,
 	                   cwd => Cwd::getcwd() }, $class);
+	my $target_bs_name;
 
 	if (exists $opts{sourcedir}) {
 		# Get relative sourcedir abs_path (without symlinks)
@@ -73,6 +124,19 @@ sub new {
 	if (defined $opts{parallel}) {
 		$this->{parallel} = $opts{parallel};
 	}
+	if (exists $opts{targetbuildsystem}) {
+		$target_bs_name = $opts{targetbuildsystem};
+	}
+
+	$target_bs_name //= $this->DEFAULT_TARGET_BUILD_SYSTEM if $this->IS_GENERATOR_BUILD_SYSTEM;
+
+	if (defined($target_bs_name)) {
+		my %target_opts = %opts;
+		delete($target_opts{'targetbuildsystem'});
+		my $target_system = load_buildsystem($target_bs_name, undef, %target_opts);
+		$this->set_targetbuildsystem($target_system);
+	}
+
 	return $this;
 }
 
@@ -104,6 +168,27 @@ sub _set_builddir {
 	return $builddir;
 }
 
+sub set_targetbuildsystem {
+	my ($this, $target_system) = @_;
+	my $ok = 0;
+	my $target_bs_name = $target_system->NAME;
+	if (not $this->IS_GENERATOR_BUILD_SYSTEM) {
+		my $name = $this->NAME;
+		error("Buildsystem ${name} is not a generator build system");
+	}
+	for my $supported_bs_name ($this->SUPPORTED_TARGET_BUILD_SYSTEMS) {
+		if ($supported_bs_name eq $target_bs_name) {
+			$ok = 1;
+			last;
+		}
+	}
+	if (not $ok) {
+		my $name = $this->NAME;
+		error("Buildsystem ${name} does not support ${target_bs_name} as target build system.");
+	}
+	$this->{targetbuildsystem} = $target_system
+}
+
 # This instance method is called to check if the build system is able
 # to build a source package. It will be called during the build
 # system auto-selection process, inside the root directory of the debian
@@ -412,6 +497,9 @@ sub pre_building_step {
 		    " does not support building out of source tree. In source building enforced.");
 		delete $this->{warn_insource};
 	}
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->pre_building_step(@_);
+	}
 }
 
 # Instance method that is called after performing any step (see below).
@@ -420,6 +508,9 @@ sub pre_building_step {
 sub post_building_step {
 	my $this=shift;
 	my ($step)=@_;
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->post_building_step(@_);
+	}
 }
 
 # The instance methods below provide support for configuring,
@@ -430,26 +521,44 @@ sub post_building_step {
 # implement build system specific steps needed to build the
 # source. Arbitrary number of custom step arguments might be
 # passed. Default implementations do nothing.
+#
+# Note: For generator build systems, the default is to
+# delegate the step to the target build system for all
+# steps except configure.
 sub configure {
 	my $this=shift;
 }
 
 sub build {
 	my $this=shift;
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->build(@_);
+	}
 }
 
 sub test {
 	my $this=shift;
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->test(@_);
+	}
 }
 
 # destdir parameter specifies where to install files.
 sub install {
 	my $this=shift;
-	my $destdir=shift;
+	my ($destdir) = @_;
+
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->install(@_);
+	}
 }
 
 sub clean {
 	my $this=shift;
+
+	if ($this->IS_GENERATOR_BUILD_SYSTEM) {
+		$this->{targetbuildsystem}->clean(@_);
+	}
 }
 
 1

lib/Debian/Debhelper/Buildsystem/cmake.pm

@@ -9,7 +9,7 @@ package Debian::Debhelper::Buildsystem::cmake;
 use strict;
 use warnings;
 use Debian::Debhelper::Dh_Lib qw(compat dpkg_architecture_value error is_cross_compiling);
-use parent qw(Debian::Debhelper::Buildsystem::makefile);
+use parent qw(Debian::Debhelper::Buildsystem);
 
 my @STANDARD_CMAKE_FLAGS = qw(
   -DCMAKE_INSTALL_PREFIX=/usr
@@ -27,16 +27,35 @@ my %DEB_HOST2CMAKE_SYSTEM = (
 	'hurd'     => 'GNU',
 );
 
+my %TARGET_BUILD_SYSTEM2CMAKE_GENERATOR = (
+	'makefile' => 'Unix Makefiles',
+	'ninja'    => 'Ninja',
+);
+
 sub DESCRIPTION {
 	"CMake (CMakeLists.txt)"
 }
 
+sub IS_GENERATOR_BUILD_SYSTEM {
+	return 1;
+}
+
+sub SUPPORTED_TARGET_BUILD_SYSTEMS {
+	return qw(makefile ninja);
+}
+
 sub check_auto_buildable {
 	my $this=shift;
 	my ($step)=@_;
 	if (-e $this->get_sourcepath("CMakeLists.txt")) {
 		my $ret = ($step eq "configure" && 1) ||
-		          $this->SUPER::check_auto_buildable(@_);
+		          $this->{targetbuildsystem}->check_auto_buildable(@_);
+		if ($step eq "clean" && defined($this->get_builddir())) {
+			# Assume that the package can be cleaned (i.e. the build directory can
+			# be removed) as long as it is built out-of-source tree and can be
+			# configured.
+			$ret++ if not $ret;
+		}
 		# Existence of CMakeCache.txt indicates cmake has already
 		# been used by a prior build step, so should be used
 		# instead of the parent makefile class.
@@ -57,10 +76,15 @@ sub configure {
 	my $this=shift;
 	# Standard set of cmake flags
 	my @flags = @STANDARD_CMAKE_FLAGS;
+	my $backend = $this->{targetbuildsystem}->NAME;
 
 	if (not compat(10)) {
 		push(@flags, '-DCMAKE_INSTALL_RUNSTATEDIR=/run');
 	}
+	if (exists($TARGET_BUILD_SYSTEM2CMAKE_GENERATOR{$backend})) {
+		my $generator = $TARGET_BUILD_SYSTEM2CMAKE_GENERATOR{$backend};
+		push(@flags, "-G${generator}");
+	}
 
 	if (is_cross_compiling()) {
 		my $deb_host = dpkg_architecture_value("DEB_HOST_ARCH_OS");
@@ -111,13 +135,16 @@ sub configure {
 
 sub test {
 	my $this=shift;
-
+	my $target = $this->{targetbuildsystem};
+	$ENV{CTEST_OUTPUT_ON_FAILURE} = 1;
+	if ($target->NAME eq 'makefile') {
 		# Unlike make, CTest does not have "unlimited parallel" setting (-j implies
 		# -j1). So in order to simulate unlimited parallel, allow to fork a huge
 		# number of threads instead.
 		my $parallel = ($this->get_parallel() > 0) ? $this->get_parallel() : 999;
-	$ENV{CTEST_OUTPUT_ON_FAILURE} = 1;
-	return $this->SUPER::test(@_, "ARGS+=-j$parallel");
+		push(@_, "ARGS+=-j$parallel")
+	}
+	return $this->SUPER::test(@_);
 }
 
 1

lib/Debian/Debhelper/Buildsystem/meson.pm

@@ -8,12 +8,21 @@ package Debian::Debhelper::Buildsystem::meson;
 use strict;
 use warnings;
 use Debian::Debhelper::Dh_Lib qw(dpkg_architecture_value is_cross_compiling doit warning error generated_file);
-use parent qw(Debian::Debhelper::Buildsystem::ninja);
+use parent qw(Debian::Debhelper::Buildsystem);
 
 sub DESCRIPTION {
 	"Meson (meson.build)"
 }
 
+sub IS_GENERATOR_BUILD_SYSTEM {
+	return 1;
+}
+
+sub SUPPORTED_TARGET_BUILD_SYSTEMS {
+	return qw(ninja);
+}
+
+
 sub check_auto_buildable {
 	my $this=shift;
 	my ($step)=@_;
@@ -22,7 +31,14 @@ sub check_auto_buildable {
 
 	# Handle configure explicitly; inherit the rest
 	return 1 if $step eq "configure";
-	return $this->SUPER::check_auto_buildable(@_);
+	my $ret = $this->{targetbuildsystem}->check_auto_buildable(@_);
+	if ($ret == 0 and $step eq 'clean' and defined($this->get_builddir())) {
+		# Assume that the package can be cleaned (i.e. the build directory can
+		# be removed) as long as it is built out-of-source tree and can be
+		# configured.
+		$ret++;
+	}
+	return $ret;
 }
 
 sub new {

lib/Debian/Debhelper/Buildsystem/ninja.pm

@@ -30,14 +30,6 @@ sub check_auto_buildable {
 		# This is always called in the source directory, but generally
 		# Ninja files are created (or live) in the build directory.
 		return 1;
-	} elsif ($step eq "clean" && defined $this->get_builddir() &&
-	         $this->check_auto_buildable("configure"))
-	{
-		# Assume that the package can be cleaned (i.e. the build directory can
-		# be removed) as long as it is built out-of-source tree and can be
-		# configured. This is useful for derivative buildsystems which
-		# generate Ninja files.
-		return 1;
 	}
 	return 0;
 }

lib/Debian/Debhelper/Dh_Buildsystems.pm

@@ -25,11 +25,12 @@ our @BUILDSYSTEMS = (
 	"makefile",
 	"python_distutils",
 	(compat(7) ? "perl_build" : ()),
-	"cmake",
+	"cmake+makefile",
+	"cmake+ninja",
 	"ant",
 	"qmake",
 	"qmake_qt4",
-	"meson",
+	"meson+ninja",
 	"ninja",
 );
 
@@ -45,13 +46,21 @@ my $opt_list;
 my $opt_parallel;
 
 sub create_buildsystem_instance {
-	my ($system, $required, %bsopts) = @_;
-	my $module = "Debian::Debhelper::Buildsystem::$system";
+	my ($full_name, $required, %bsopts) = @_;
+	my @parts = split(m{[+]}, $full_name, 2);
+	my $name = $parts[0];
+	my $module = "Debian::Debhelper::Buildsystem::$name";
+	if (@parts > 1) {
+		if (exists($bsopts{'targetbuildsystem'})) {
+			error("Conflicting target buildsystem for ${name} (load as ${full_name}, but target configured in bsopts)");
+		}
+		$bsopts{'targetbuildsystem'} = $parts[1];
+	}
 
 	eval "use $module";
 	if ($@) {
 		return if not $required;
-		error("unable to load build system class '$system': $@");
+		error("unable to load build system class '$name': $@");
 	}
 
 	if (!exists $bsopts{builddir} && defined $opt_builddir) {
@@ -73,9 +82,15 @@ sub autoselect_buildsystem {
 	my $selected_level = 0;
 
 	foreach my $inst (@_) {
-		# Only derived (i.e. more specific) build system can be
-		# considered beyond the currently selected one.
-		next if defined $selected && !$inst->isa(ref $selected);
+		# Only  more specific build system can be considered beyond
+		# the currently selected one.
+		if (defined($selected)) {
+			my $ok = $inst->isa(ref($selected)) ? 1 : 0;
+			if (not $ok and $inst->IS_GENERATOR_BUILD_SYSTEM) {
+				$ok = 1 if $inst->{targetbuildsystem}->NAME eq $selected->NAME;
+			}
+			next if not $ok;
+		}
 
 		# If the build system says it is auto-buildable at the current
 		# step and it can provide more specific information about its
@@ -121,7 +136,8 @@ sub load_buildsystem {
 
 sub load_all_buildsystems {
 	my $incs=shift || \@INC;
-	my (%buildsystems, @buildsystems);
+	my %opts = @_;
+	my (%buildsystems, %genbuildsystems, @buildsystems);
 
 	foreach my $inc (@$incs) {
 		my $path = File::Spec->catdir($inc, "Debian/Debhelper/Buildsystem");
@@ -129,8 +145,19 @@ sub load_all_buildsystems {
 			foreach my $module_path (glob "$path/*.pm") {
 				my $name = basename($module_path);
 				$name =~ s/\.pm$//;
-				next if exists $buildsystems{$name};
-				$buildsystems{$name} = create_buildsystem_instance($name, 1, @_);
+				next if exists $buildsystems{$name} or exists $genbuildsystems{$name};
+				my $system = create_buildsystem_instance($name, 1, %opts);
+				if ($system->IS_GENERATOR_BUILD_SYSTEM) {
+					$genbuildsystems{$name} = 1;
+					for my $target_name ($system->SUPPORTED_TARGET_BUILD_SYSTEMS) {
+						my $full_name = "${name}+${target_name}";
+						my $full_system = create_buildsystem_instance($name, 1, %opts,
+							'targetbuildsystem' => $target_name);
+						$buildsystems{$full_name} = $full_system;
+					}
+				} else {
+					$buildsystems{$name} = $system;
+				}
 			}
 		}
 	}
@@ -209,22 +236,31 @@ sub buildsystems_list {
 	my @buildsystems = load_all_buildsystems();
 	my %auto_selectable = map { $_ => 1 } @THIRD_PARTY_BUILDSYSTEMS;
 	my $auto = autoselect_buildsystem($step, grep { ! $_->{thirdparty} || $auto_selectable{$_->NAME} } @buildsystems);
-	my $specified;
+	my $specified_text;
+
+	if ($opt_buildsys) {
+		for my $inst (@buildsystems) {
+			my $full_name = $inst->NAME;
+			if ($full_name eq $opt_buildsys) {
+				$specified_text = $full_name;
+			} elsif ($inst->IS_GENERATOR_BUILD_SYSTEM and ref($inst)->NAME eq $opt_buildsys) {
+				my $default = $inst->DEFAULT_TARGET_BUILD_SYSTEM;
+				$specified_text = "${opt_buildsys}+${default} (default for ${opt_buildsys})";
+			}
+		}
+	}
 
 	# List build systems (including auto and specified status)
 	foreach my $inst (@buildsystems) {
-		if (! defined $specified && defined $opt_buildsys && $opt_buildsys eq $inst->NAME()) {
-			$specified = $inst;
-		}
-		printf("%-20s %s", $inst->NAME(), $inst->DESCRIPTION());
+		printf("%-20s %s", $inst->NAME(), $inst->FULL_DESCRIPTION());
 		print " [3rd party]" if $inst->{thirdparty};
 		print "\n";
 	}
 	print "\n";
 	print "Auto-selected: ", $auto->NAME(), "\n" if defined $auto;
-	print "Specified: ", $specified->NAME(), "\n" if defined $specified;
+	print "Specified: ", $specified_text, "\n" if defined $specified_text;
 	print "No system auto-selected or specified\n"
-		if ! defined $auto && ! defined $specified;
+		if ! defined $auto && ! defined $specified_text;
 }
 
 sub buildsystems_do {

t/buildsystems/03-bs-auto-buildable.t

@@ -2,7 +2,7 @@
 
 use strict;
 use warnings;
-use Test::More tests => 182;
+use Test::More tests => 187;
 
 use File::Temp qw(tempdir);
 use File::Basename qw(dirname);
@@ -90,7 +90,7 @@ sub run_auto_buildable_tests {
 	rm_files("${sourcedir}/configure");
 
 	create_empty_file("${sourcedir}/CMakeLists.txt");
-	test_check_auto_buildable($bs{cmake}, "CMakeLists.txt", { configure => 1, clean => 1 });
+	test_check_auto_buildable($bs{'cmake+makefile'}, "CMakeLists.txt", { configure => 1, clean => 1 });
 	rm_files("${sourcedir}/CMakeLists.txt");
 
 	create_empty_file("${sourcedir}/Makefile.PL");
@@ -98,7 +98,7 @@ sub run_auto_buildable_tests {
 	rm_files("${sourcedir}/Makefile.PL");
 
 	create_empty_file("${sourcedir}/meson.build");
-	test_check_auto_buildable($bs{meson}, "meson.build", { configure => 1, clean => 1 });
+	test_check_auto_buildable($bs{'meson+ninja'}, "meson.build", { configure => 1, clean => 1 });
 	# Leave meson.build
 
 	create_empty_file("${builddir}/build.ninja");
@@ -106,7 +106,7 @@ sub run_auto_buildable_tests {
 	# Leave ninja.build
 
 	# Meson + ninja
-	test_check_auto_buildable($bs{meson}, "meson.build+build.ninja", { configure => 1, build => 1, clean => 1, install => 1, test => 1 });
+	test_check_auto_buildable($bs{'meson+ninja'}, "meson.build+build.ninja", { configure => 1, build => 1, clean => 1, install => 1, test => 1 });
 	rm_files("${sourcedir}/meson.build", "${builddir}/build.ninja");
 
 	# With Makefile
@@ -120,9 +120,9 @@ sub run_auto_buildable_tests {
 
 	# ... +cmake
 	create_empty_file("${sourcedir}/CMakeLists.txt");
-	test_check_auto_buildable($bs{cmake}, "CMakeLists.txt+Makefile", 1);
+	test_check_auto_buildable($bs{'cmake+makefile'}, "CMakeLists.txt+Makefile", 1);
 	create_empty_file("$builddir/CMakeCache.txt"); # strong evidence that cmake was run
-	test_check_auto_buildable($bs{cmake}, "CMakeCache.txt+Makefile", 2);
+	test_check_auto_buildable($bs{'cmake+makefile'}, "CMakeCache.txt+Makefile", 2);
 	rm_files("${builddir}/Makefile", "${sourcedir}/CMakeLists.txt");
 
 	# Makefile.PL forces in-source
@@ -189,7 +189,7 @@ sub run_autoselection_tests {
 	# CMake
 	create_empty_file("${sourcedir}/CMakeLists.txt");
 	test_autoselection("cmake without CMakeCache.txt",
-					   { configure => "cmake", build => "makefile",
+					   { configure => "cmake+makefile", build => "makefile",
 						 test => "makefile", install => "makefile",
 						 clean => "makefile"
 					   },
@@ -201,7 +201,7 @@ sub run_autoselection_tests {
 
 	create_empty_file("${sourcedir}/CMakeLists.txt");
 	test_autoselection("cmake with CMakeCache.txt",
-					   "cmake",
+					   "cmake+makefile",
 					   %options,
 					   code_configure => sub {
 						   create_empty_file("$builddir/Makefile");