reduce amount of MAKEFLAGS cleaning

Now clean_jobserver_makeflags will only remove --jobserver settings
from MAKEFLAGS. This is simpler and easier to understand than
the old behavior, which, if there was no --jobserver, removed
all -j and --jobs, while leaving those when removing --jobserver.

This relies on -j options passed to make overriding
-j settings in MAKEFLAGS. So we don't need to clean those out,
we can just override them.

2 files changed, 11 insertions, 14 deletions

diff --git a/Debian/Debhelper/Buildsystem/makefile.pm b/Debian/Debhelper/Buildsystem/makefile.pm
index 159f7c1e..ff904afd 100644
--- a/Debian/Debhelper/Buildsystem/makefile.pm
+++ b/Debian/Debhelper/Buildsystem/makefile.pm
@@ -8,7 +8,7 @@ package Debian::Debhelper::Buildsystem::makefile;
 
 use strict;
 use Debian::Debhelper::Dh_Lib qw(escape_shell is_make_jobserver_unavailable
-	clean_makeflags);
+	clean_jobserver_makeflags);
 use base 'Debian::Debhelper::Buildsystem';
 
 sub get_makecmd_C {
@@ -34,17 +34,16 @@ sub exists_make_target {
 sub do_make {
 	my $this=shift;
 
-	# Remove unavailable jobserver options from MAKEFLAGS.
-	# Always clean MAKEFLAGS from unavailable jobserver options. If parallel
-	# is enabled, do more extensive clean up from all job control specific
-	# options
-	if (defined $this->get_parallel() || is_make_jobserver_unavailable()) {
-		clean_makeflags();
+	# Avoid warnings about unavailable jobserver.
+	if (is_make_jobserver_unavailable()) {
+		clean_jobserver_makeflags();
 	}
 
-	# Start a new jobserver if parallel building was requested
 	if (defined $this->get_parallel()) {
+		# Note that this will override any -j settings in MAKEFLAGS.
 		unshift @_, "-j" . ($this->get_parallel() > 1 ? $this->get_parallel() : 1);
+		# Force make to start a new jobserver.
+		clean_jobserver_makeflags();
 	}
 
 	$this->doit_in_builddir($this->{makecmd}, @_);
diff --git a/Debian/Debhelper/Dh_Lib.pm b/Debian/Debhelper/Dh_Lib.pm
index ac0d8ab4..8af365ff 100644
--- a/Debian/Debhelper/Dh_Lib.pm
+++ b/Debian/Debhelper/Dh_Lib.pm
@@ -16,7 +16,8 @@ use vars qw(@ISA @EXPORT %dh);
 	    &compat &addsubstvar &delsubstvar &excludefile &package_arch
 	    &is_udeb &udeb_filename &debhelper_script_subst &escape_shell
 	    &inhibit_log &load_log &write_log &dpkg_architecture_value
-	    &sourcepackage &is_make_jobserver_unavailable &clean_makeflags);
+	    &sourcepackage
+	    &is_make_jobserver_unavailable &clean_jobserver_makeflags);
 
 my $max_compat=7;
 
@@ -811,16 +812,13 @@ sub is_make_jobserver_unavailable {
 	return; # no jobserver specified
 }
 
-# Cleans out job control options from MAKEFLAGS.
-sub clean_makeflags {
+# Cleans out jobserver options from MAKEFLAGS.
+sub clean_jobserver_makeflags {
 	if (exists $ENV{MAKEFLAGS}) {
 		if ($ENV{MAKEFLAGS} =~ /(?:^|\s)--jobserver-fds=(\d+)/) {
 			$ENV{MAKEFLAGS} =~ s/(?:^|\s)--jobserver-fds=\S+//g;
 			$ENV{MAKEFLAGS} =~ s/(?:^|\s)-j\b//g;
 		}
-		else {
-			$ENV{MAKEFLAGS} =~ s/(?:^|\s)(?:(?:-j\s*|--jobs(?:=|\s+))(\d+)?|--jobs)\b//g;
-		}
 		delete $ENV{MAKEFLAGS} if $ENV{MAKEFLAGS} =~ /^\s*$/;
 	}
 }