Dh_Lib: new function perl_cross_incdir

Since perl/5.30.0-7, the perl-xs-dev package provides the host
architecture Config.pm in /usr/lib/<triplet>/perl/cross-config-<version>
for the benefit of cross builds.

For more information, see the thread around

  https://lists.debian.org/debian-perl/2019/10/msg00015.html

1 files changed, 16 insertions, 0 deletions

diff --git a/lib/Debian/Debhelper/Dh_Lib.pm b/lib/Debian/Debhelper/Dh_Lib.pm
index 47cca1fb..33187e33 100644
--- a/lib/Debian/Debhelper/Dh_Lib.pm
+++ b/lib/Debian/Debhelper/Dh_Lib.pm
@@ -146,6 +146,7 @@ qw(
 	is_cross_compiling
 	is_build_profile_active
 	get_buildoption
+	perl_cross_incdir
 ),
 	# Other
 qw(
@@ -2708,6 +2709,21 @@ sub dbgsym_tmpdir {
 	return "debian/.debhelper/${package}/dbgsym-root";
 }
 
+sub perl_cross_incdir {
+	return if !is_cross_compiling();
+
+	# native builds don't currently need this so only load it on demand
+	require Config; Config->import();
+
+	my $triplet = dpkg_architecture_value("DEB_HOST_MULTIARCH");
+	my $perl_version = $Config::Config{version};
+	my $incdir = "/usr/lib/$triplet/perl/cross-config-${perl_version}";
+	if (!-e "$incdir/Config.pm") {
+		warning("$incdir/Config.pm does not exist (missing build dependency on perl-xs-dev?)");
+		return;
+	}
+	return $incdir;
+}
 
 {
 	my %known_packages;