2 files changed, 259 insertions, 0 deletions
diff --git a/lib/Debian/Debhelper/DH/AddonAPI.pm b/lib/Debian/Debhelper/DH/AddonAPI.pm
new file mode 100644
index 0000000..44082a9
--- /dev/null
+++ b/lib/Debian/Debhelper/DH/AddonAPI.pm
@@ -0,0 +1,228 @@
+# Defines dh sequence state variables
+#
+# License: GPL-2+
+
+package Debian::Debhelper::DH::AddonAPI;
+use strict;
+use warnings;
+
+use Debian::Debhelper::Dh_Lib qw(warning error);
+use Debian::Debhelper::Sequence;
+use Debian::Debhelper::SequencerUtil;
+use Debian::Debhelper::DH::SequenceState;
+
+
+our ($DH_INTERNAL_ADDON_TYPE, $DH_INTERNAL_ADDON_NAME);
+
+sub _add_sequence {
+	my @args = @_;
+	my $seq = Debian::Debhelper::Sequence->new(@args);
+	my $name = $seq->name;
+	$Debian::Debhelper::DH::SequenceState::sequences{$name} = $seq;
+	if ($seq->allowed_subsequences eq SEQUENCE_ARCH_INDEP_SUBSEQUENCES) {
+		for my $subseq ((SEQUENCE_TYPE_ARCH_ONLY, SEQUENCE_TYPE_INDEP_ONLY)) {
+			my $subname = "${name}-${subseq}";
+			$Debian::Debhelper::DH::SequenceState::sequences{$subname} = $seq;
+		}
+	}
+	return;
+}
+
+sub _skip_cmd_if_deb_build_options_contains {
+	my ($command, $flag) = @_;
+	push(@{$Debian::Debhelper::DH::SequenceState::commands_skippable_via_deb_build_options{$command}}, $flag);
+	return;
+}
+
+sub _assert_not_conditional_sequence_addon {
+	my ($feature) = @_;
+	return if $DH_INTERNAL_ADDON_TYPE eq 'both';
+	warning("The add-on ${DH_INTERNAL_ADDON_NAME} relies on a feature (${feature}) (possibly indirectly), which is "
+		. 'not supported for conditional debhelper sequence add-ons.');
+	warning("Hint: You may have to move the build-dependency for dh-sequence-${DH_INTERNAL_ADDON_NAME} to "
+		. 'Build-Depends to avoid this error assuming it is possible to use the sequence unconditionally.');
+	error("${feature} is not supported for conditional dh sequence add-ons.\n");
+}
+
+sub _filter_sequences_for_conditional_add_ons {
+	my @sequences = @_;
+	# If it is unconditional, then there is no issues.
+	return @sequences if $DH_INTERNAL_ADDON_TYPE eq 'both' or not @sequences;
+	for my $seq (@sequences) {
+		# Typically, if you add a command to a sequence, then you will in fact add it to two. E.g.
+		# Adding dh_foo after dh_installdocs will affect both install-arch AND install-indep.  We want
+		# this to "just work(tm)" with a conditional add-on to avoid too much hassle (i.e. only affect
+		# the relevant sequence).  At the same time, we must abort if a sequence like "clean" is
+		# affected.
+		#
+		# We solve the above by checking if the sequence has an -arch + an -indep variant and then
+		# insert the command only for that sequence variant.
+
+		if ($seq->allowed_subsequences ne SEQUENCE_ARCH_INDEP_SUBSEQUENCES) {
+			my $sequence_name = $seq->name;
+			warning("The add-on ${DH_INTERNAL_ADDON_NAME} attempted to modify the sequence ${sequence_name} (possibly "
+				. "indirectly) but the add-on is conditional for \"*-${DH_INTERNAL_ADDON_TYPE}\" targets");
+			warning("Hint: You may have to move the build-dependency for dh-sequence-${DH_INTERNAL_ADDON_NAME} to "
+				. 'Build-Depends to avoid this error assuming it is possible to use the sequence unconditionally.');
+			error("The add-on ${DH_INTERNAL_ADDON_NAME} cannot be use conditionally for \"*-${DH_INTERNAL_ADDON_TYPE}\""
+				. " targets\n");
+		}
+	}
+	return @sequences;
+}
+
+sub _register_cmd_added_by_addon {
+	my ($cmd) = @_;
+	my $existing = $Debian::Debhelper::DH::SequenceState::commands_added_by_addon{$cmd};
+	if ($existing) {
+		if ($existing->{'addon-type'} ne $DH_INTERNAL_ADDON_TYPE) {
+			my $old_addon_name = $existing->{'addon-name'};
+			my $old_addon_type = $existing->{'addon-type'};
+			# Technically, "both" could be made compatible with "indep" OR "arch" (but not both at the same time).
+			# Implement if it turns out to be relevant.
+			warning("Both dh sequence add-ons ${DH_INTERNAL_ADDON_NAME} and ${old_addon_name} have attempted to add "
+				. "the command $cmd (possibly indirectly).");
+			warning("However, the two add-ons do not have compatible constraints (${DH_INTERNAL_ADDON_TYPE} vs. "
+				. "${old_addon_type}).");
+			warning("Hint: You may have to move the build-dependency for dh-sequence-<X> to "
+				. ' the same build-dependency field to avoid this error assuming it is possible.');
+			error("Multiple sequences have conflicting requests for $cmd.\n");
+		}
+		return;
+	}
+
+	$Debian::Debhelper::DH::SequenceState::commands_added_by_addon{$cmd} = {
+		'addon-name' => $DH_INTERNAL_ADDON_NAME,
+		'addon-type' => $DH_INTERNAL_ADDON_TYPE,
+	};
+	return;
+}
+
+sub _sequences_containing_cmd {
+	my ($cmd) = @_;
+	my @sequences;
+	foreach my $sequence_name (keys(%Debian::Debhelper::DH::SequenceState::sequences)) {
+		my $seq = $Debian::Debhelper::DH::SequenceState::sequences{$sequence_name};
+		for my $scmd (@{$seq->{'_cmds'}}) {
+			if ($scmd->{'command'} eq $cmd) {
+				push(@sequences, $seq);
+				last;
+			}
+		}
+	}
+	return @sequences;
+}
+
+sub _seq_cmd {
+	my ($cmd_name) = @_;
+	return {
+		'command'             => $cmd_name,
+		'command-options'     => [],
+		'sequence-limitation' => $DH_INTERNAL_ADDON_TYPE,
+	};
+}
+
+# sequence addon interface
+sub _insert {
+	my ($offset, $existing, $new) = @_;
+	my @affected_sequences = _sequences_containing_cmd($existing);
+	@affected_sequences = _filter_sequences_for_conditional_add_ons(@affected_sequences);
+	return if not @affected_sequences;
+	_register_cmd_added_by_addon($new);
+	for my $seq (@affected_sequences) {
+		$seq->_insert($offset, $existing, _seq_cmd($new));
+	}
+	return 1;
+}
+sub insert_before {
+	return _insert(-1, @_);
+}
+sub insert_after {
+	return _insert(1, @_);
+}
+sub remove_command {
+	my ($command) = @_;
+	# Implement if actually needed (I *think* it basically means to transform dh_foo to dh_foo -a/-i)
+	_assert_not_conditional_sequence_addon('remove_command');
+	my @affected_sequences = _sequences_containing_cmd($command);
+	@affected_sequences = _filter_sequences_for_conditional_add_ons(@affected_sequences);
+	return 1 if not @affected_sequences;
+	for my $seq (@affected_sequences) {
+		$seq->remove_command($command);
+	}
+	return 1;
+}
+sub add_command {
+	my ($command, $sequence) = @_;
+	_assert_not_conditional_sequence_addon('add_command');
+	_register_cmd_added_by_addon($command);
+	if (not exists($Debian::Debhelper::DH::SequenceState::sequences{$sequence})) {
+		_add_sequence($sequence, SEQUENCE_NO_SUBSEQUENCES, _seq_cmd($command));
+	} else {
+		my $seq = $Debian::Debhelper::DH::SequenceState::sequences{$sequence};
+		_filter_sequences_for_conditional_add_ons($seq);
+		$seq->add_command_at_start(_seq_cmd($command))
+	}
+	return 1;
+}
+sub add_command_at_end {
+	my ($command, $sequence) = @_;
+	_assert_not_conditional_sequence_addon('add_command');
+	_register_cmd_added_by_addon($command);
+	if (not exists($Debian::Debhelper::DH::SequenceState::sequences{$sequence})) {
+		_add_sequence($sequence, SEQUENCE_NO_SUBSEQUENCES, _seq_cmd($command));
+	} else {
+		my $seq = $Debian::Debhelper::DH::SequenceState::sequences{$sequence};
+		_filter_sequences_for_conditional_add_ons($seq);
+		$seq->add_command_at_end(_seq_cmd($command))
+	}
+	return 1;
+}
+
+sub add_command_options {
+	my $command=shift;
+	# Implement if actually needed (Complicated as dh_foo becomes dh_foo -a && dh_foo -i <extra_options>
+	# and that implies smarter deduplication logic)
+	_assert_not_conditional_sequence_addon('add_command_options');
+	push(@{$Debian::Debhelper::DH::SequenceState::command_opts{$command}}, @_);
+	return 1;
+}
+
+sub remove_command_options {
+	my ($command, @cmd_options) = @_;
+	# Implement if actually needed (Complicated as dh_foo <extra_options> becomes
+	#   dh_foo -a  <extra_options> && dh_foo -i and that implies smarter deduplication logic)
+	_assert_not_conditional_sequence_addon('remove_command_options');
+	if (@cmd_options) {
+		# Remove only specified options
+		if (my $opts = $Debian::Debhelper::DH::SequenceState::command_opts{$command}) {
+			foreach my $opt (@cmd_options) {
+				$opts = [ grep { $_ ne $opt } @$opts ];
+			}
+			$Debian::Debhelper::DH::SequenceState::command_opts{$command} = $opts;
+		}
+	}
+	else {
+		# Clear all additional options
+		delete($Debian::Debhelper::DH::SequenceState::command_opts{$command});
+	}
+	return 1;
+}
+
+sub declare_command_obsolete {
+	my ($error_compat, $command) = @_;
+	if (not defined($command) and defined($error_compat)) {
+		# Backwards compat - originally this only accepted one command.
+		$command = $error_compat;
+		$error_compat = 13;
+	}
+	if ($error_compat < 13) {
+		error("Minimum error compat is 13 (got ${error_compat} for command: ${command})");
+	}
+	_assert_not_conditional_sequence_addon('declare_command_obsolete');
+	$Debian::Debhelper::DH::SequenceState::obsolete_command{$command} = [$DH_INTERNAL_ADDON_NAME, $error_compat];
+	return 1;
+}
+
+
+1;
diff --git a/lib/Debian/Debhelper/DH/SequenceState.pm b/lib/Debian/Debhelper/DH/SequenceState.pm
new file mode 100644
index 0000000..b029e01
--- /dev/null
+++ b/lib/Debian/Debhelper/DH/SequenceState.pm
@@ -0,0 +1,31 @@
+# Defines dh sequence state variables
+#
+# License: GPL-2+
+
+package Debian::Debhelper::DH::SequenceState;
+use strict;
+use warnings;
+
+our (
+	# Definitions of sequences.
+	%sequences,
+	# Additional command options
+	%command_opts,
+	# Track commands added by (which) addons
+	%commands_added_by_addon,
+	# Removed commands
+	%obsolete_command,
+	# Commands that can be skipped due to DEB_BUILD_OPTIONS=X flags
+	%commands_skippable_via_deb_build_options,
+	# Options passed that should be passed on to underlying helpers (in order)
+	@options,
+	# Options passed by name (to assist can_skip with which options are used)
+	%seen_options,
+	# Whether there were sequences of options that inhibit certain optimizations
+	# * $unoptimizable_option_bundle => can skip iff cli-options hint is present and empty
+	# * $unoptimizable_user_option => We can never skip anything (non-option seen)
+	$unoptimizable_option_bundle,
+	$unoptimizable_user_option,
+);
+
+1;