Support parallel building in makefile buildsystem

[debhelper.git] / dh

diff --git a/dh b/dh
index 710117ead15d9db779a913b4068118e3322a2367..9d1fca0eaa073dcc34c8feb619101b3d3f948c42 100755 (executable)
--- a/dh
+++ b/dh
@@ -41,6 +41,13 @@ override target can then run the command with additional options, or run
 entirely different commands instead. (Note that to use this feature,
 you should Build-Depend on debhelper 7.0.50 or above.)
 
+dh passes --parallel to dh_auto_* commands if it detects being run by the
+C<dpkg-buildpackage -jX> command, but a job server of the parent I<make>
+(presumably debian/rules) is not reachable. Nonetheless, it is highly
+recommended to pass --parallel/-j option to dh explicitly to indicate that a
+source package supports parallel building. See L<debhelper(7)/"BUILD SYSTEM
+OPTIONS"> for more information.
+
 =head1 OPTIONS
 
 =over 4
@@ -222,9 +229,33 @@ init(options => {
        },
        "l" => \$dh{LIST},
        "list" => \$dh{LIST},
+       "j:i" => \$dh{PARALLEL},
+       "parallel:i" => \$dh{PARALLEL},
 });
 inhibit_log();
 
+# Parallel defaults to "unset" unless unavailable --jobserver-fds is detected
+# in MAKEFLAGS. This typically means dpkg-buildpackage was called with a -jX
+# option. Then -jX in MAKEFLAGS gets "consumed" by make invocation of
+# debian/rules and "converted" to --jobserver-fds.  If jobserver is
+# unavailable, dh was probably called via debian/rules without "+" prefix (so
+# make has closed jobserver FDs). In such a case, MAKEFLAGS is cleaned from the
+# offending --jobserver-fds option in order to prevent further make invocations
+# from spitting warnings and disabling job support.
+my ($status, $makeflags) = get_make_jobserver_status();
+if ($status eq "jobserver-unavailable") {
+       # Stop make from spitting pointless job control warnings
+       if (defined $makeflags) {
+               $ENV{MAKEFLAGS} = $makeflags;
+       }
+       else {
+               delete $ENV{MAKEFLAGS};
+       }
+       # Enable parallel (no maximum) if the package doesn't since it appears this
+       # dh is called via dpkg-buildpackage -jX.
+       $dh{PARALLEL} = 0 if !defined $dh{PARALLEL};
+}
+
 # Definitions of sequences.
 my %sequences;
 $sequences{build} = [qw{
@@ -253,7 +284,6 @@ $sequences{install} = [@{$sequences{build}}, qw{
        dh_installcatalogs
        dh_installcron
        dh_installdebconf
-       dh_installcatalogs
        dh_installemacsen
        dh_installifupdown
        dh_installinfo
@@ -432,7 +462,12 @@ while (@ARGV_orig) {
                shift @ARGV_orig;
                next;
        }
-       elsif ($opt =~ /^--?(no-act|remaining|(after|until|before|with|without)=)/) {
+       elsif ($opt =~ /^--?(no-act|remaining|(after|until|before|with|without|parallel)=)/) {
+               next;
+       }
+       elsif ($opt =~ /^(-j|--parallel)$/) {
+               # Argument to -j/--parallel is optional.
+               shift @ARGV_orig if @ARGV_orig > 0 && $ARGV_orig[0] =~ /^\d+$/;
                next;
        }
        push @options, $opt;
@@ -513,6 +548,12 @@ sub run {
        # to prevent them from being acted on.
        push @options, map { "-N$_" } @exclude;
 
+       # Pass --parallel to dh_auto_* commands if requested
+       if (defined $dh{PARALLEL} && ($dh{PARALLEL} == 0 || $dh{PARALLEL} > 1)
+           && $command =~ /^dh_auto_/) {
+               push @options, "--parallel" . ($dh{PARALLEL} > 1 ? "=$dh{PARALLEL}" : "");
+       }
+
        # Check for override targets in debian/rules and
        # run them instead of running the command directly.
        my $override_command;