Improve build system auto-selection process

[debhelper.git] / Debian / Debhelper / Dh_Buildsystems.pm

diff --git a/Debian/Debhelper/Dh_Buildsystems.pm b/Debian/Debhelper/Dh_Buildsystems.pm
index d37c593d48e4ed0fe08d0178dc980a4512b78080..2893c1a4c626dea352708e3c38cbb47f615cf6dd 100644 (file)
--- a/Debian/Debhelper/Dh_Buildsystems.pm
+++ b/Debian/Debhelper/Dh_Buildsystems.pm
@@ -14,21 +14,25 @@ use File::Spec;
 use base 'Exporter';
 our @EXPORT=qw(&buildsystems_init &buildsystems_do &load_buildsystem &load_all_buildsystems);
 
+use constant BUILD_STEPS => qw(configure build test install clean);
+
 # Historical order must be kept for backwards compatibility. New
 # build systems MUST be added to the END of the list.
 our @BUILDSYSTEMS = (
-    "autoconf",
-    "perl_makemaker",
-    "makefile",
-    "python_distutils",
-    "perl_build",
-    "cmake",
+       "autoconf",
+       "perl_makemaker",
+       "makefile",
+       "python_distutils",
+       "perl_build",
+       "cmake",
+       "ant",
 );
 
 my $opt_buildsys;
 my $opt_sourcedir;
 my $opt_builddir;
 my $opt_list;
+my $opt_parallel;
 
 sub create_buildsystem_instance {
        my $system=shift;
@@ -46,6 +50,9 @@ sub create_buildsystem_instance {
        if (!exists $bsopts{sourcedir} && defined $opt_sourcedir) {
                $bsopts{sourcedir} = ($opt_sourcedir eq "") ? undef : $opt_sourcedir;
        }
+       if (!exists $bsopts{parallel}) {
+               $bsopts{parallel} = $opt_parallel;
+       }
        return $module->new(%bsopts);
 }
 
@@ -61,14 +68,26 @@ sub load_buildsystem {
        }
        else {
                # Try to determine build system automatically
+               my $selected;
+               my $selected_level = 0;
                for $system (@BUILDSYSTEMS) {
                        my $inst = create_buildsystem_instance($system, @_);
-                       if ($inst->check_auto_buildable($step)) {
-                               return $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);
+
+                       # If the build system says it is auto-buildable at the current
+                       # step and it can provide more specific information about its
+                       # status than its parent (if any), auto-select it.
+                       my $level = $inst->check_auto_buildable($step);
+                       if ($level > $selected_level) {
+                               $selected = $inst;
+                               $selected_level = $level;
                        }
                }
+               return $selected;
        }
-       return;
 }
 
 sub load_all_buildsystems {
@@ -87,7 +106,7 @@ sub load_all_buildsystems {
                }
        }
 
-       # Push standard debhelper build systems first
+       # Standard debhelper build systems first
        for my $name (@BUILDSYSTEMS) {
                error("standard debhelper build system '$name' could not be found/loaded")
                    if not exists $buildsystems{$name};
@@ -107,6 +126,8 @@ sub load_all_buildsystems {
 
 sub buildsystems_init {
        my %args=@_;
+       
+       my $max_parallel=-1; # unlimited
 
        # Available command line options
        my %options = (
@@ -121,9 +142,33 @@ sub buildsystems_init {
 
            "l" => \$opt_list,
            "list" => \$opt_list,
+
+           "max-parallel=i" => \$max_parallel,
        );
        $args{options}{$_} = $options{$_} foreach keys(%options);
        Debian::Debhelper::Dh_Lib::init(%args);
+       set_parallel($max_parallel);
+}
+
+sub set_parallel {
+       my $max=shift;
+
+       $opt_parallel=1;
+
+       if (exists $ENV{DEB_BUILD_OPTIONS}) {
+               # Parse parallel=n tag
+               foreach my $opt (split(/\s+/, $ENV{DEB_BUILD_OPTIONS})) {
+                       if ($opt =~ /^parallel=([-\d]+)$/) {
+                               my $n=$1;
+                               if ($n > 0 && ($max == -1 || $n < $max)) {
+                                       $opt_parallel = $n;
+                               }
+                               else {
+                                       $opt_parallel = $max;
+                               }
+                       }
+               }
+       }
 }
 
 sub buildsystems_list {
@@ -131,8 +176,7 @@ sub buildsystems_list {
 
        # List build systems (including auto and specified status)
        my ($auto, $specified);
-       my @buildsystems = load_all_buildsystems();
-       for my $inst (@buildsystems) {
+       for my $inst (load_all_buildsystems()) {
                my $is_specified = defined $opt_buildsys && $opt_buildsys eq $inst->NAME();
                if (! defined $specified && defined $opt_buildsys && $opt_buildsys eq $inst->NAME()) {
                        $specified = $inst->NAME();
@@ -140,7 +184,7 @@ sub buildsystems_list {
                elsif (! defined $auto && ! $inst->{thirdparty} && $inst->check_auto_buildable($step)) {
                        $auto = $inst->NAME();
                }
-               printf("%s - %s", $inst->NAME(), $inst->DESCRIPTION());
+               printf("%-20s %s", $inst->NAME(), $inst->DESCRIPTION());
                print " [3rd party]" if $inst->{thirdparty};
                print "\n";
        }
@@ -159,7 +203,7 @@ sub buildsystems_do {
                $step =~ s/^dh_auto_//;
        }
 
-       if (grep(/^\Q$step\E$/, qw{configure build test install clean}) == 0) {
+       if (grep(/^\Q$step\E$/, BUILD_STEPS) == 0) {
                error("unrecognized build step: " . $step);
        }
 
@@ -177,4 +221,4 @@ sub buildsystems_do {
        return 0;
 }
 
-1;
+1