introduce support for sdkroot and sysroot to support cross-builds

To allow building for another location rather the final install prefix,
regardless whether chroot based builds, cross-compile or canadian cross sdk
is the goal, realize the difference between prefix, the sdk-root and the
system root for final target.

Signed-off-by: Jens Rehsack <sno@netbsd.org>

Configure.pl

@@ -32,6 +32,7 @@
 
     my %options;
     GetOptions(\%options, 'help!', 'prefix=s',
+               'sysroot=s', 'sdkroot=s',
                'backends=s', 'no-clean!',
                'gen-nqp:s', 'gen-moar:s',
                'make-install!', 'makefile-timing!',
@@ -59,9 +60,9 @@
     }
 
     unless (defined $options{prefix}) {
-        my $dir = getcwd;
-        print "ATTENTION: no --prefix supplied, building and installing to $dir/install\n";
-        $options{prefix} = 'install';
+	my $default = defined($options{sysroot}) ? '/usr' : File::Spec->catdir(getcwd, 'install');
+        print "ATTENTION: no --prefix supplied, building and installing to $default\n";
+        $options{prefix} = $default;
     }
     $options{prefix} = File::Spec->rel2abs($options{prefix});
 
@@ -148,6 +149,8 @@
     }
 
     $config{prefix} = $prefix;
+    $config{sdkroot} = $options{sdkroot};
+    $config{sysroot} = $options{sysroot};
     $config{slash}  = $slash;
     $config{'makefile-timing'} = $options{'makefile-timing'};
     $config{'stagestats'} = '--stagestats' if $options{'makefile-timing'};
@@ -263,6 +266,9 @@ sub print_help {
 General Options:
     --help             Show this text
     --prefix=dir       Install files in dir; also look for executables there
+    --sdkroot=dir      When given, use for searching build tools here, e.g.
+                       nqp, java etc.
+    --sysroot=dir      When given, use for searching runtime components here
     --backends=jvm,moar
                        Which backend(s) to use
     --gen-moar[=branch]

tools/build/Makefile.in

@@ -7,6 +7,8 @@ STAR_VERSION = 2015.09
 
 # install location
 PREFIX_DIR         = @prefix@
+SDKROOT_DIR        = @sdkroot@
+SYSROOT_DIR        = @sysroot@
 
 # JVM install location
 JVM_BIN_DIR = $(PREFIX_DIR)/bin
@@ -40,7 +42,7 @@ rakudo: @backend_exes@
 
 @backend_exes@:
 	@echo "== Configuring and building Rakudo"
-	cd $(RAKUDO_DIR) && $(PERL) Configure.pl --prefix=$(PREFIX_DIR) --backends=@backends@ && $(MAKE)
+	cd $(RAKUDO_DIR) && $(PERL) Configure.pl --sysroot=$(SYSROOT_DIR) --sdkroot=$(SDKROOT_DIR) --prefix=$(PREFIX_DIR) --backends=@backends@ && $(MAKE)
 
 rakudo-test: rakudo
 	cd $(RAKUDO_DIR) && $(MAKE) test

tools/lib/NQP/Configure.pm

@@ -3,6 +3,7 @@ use strict;
 use warnings;
 use Cwd;
 use File::Copy qw(copy);
+use File::Spec qw();
 
 use base qw(Exporter);
 our @EXPORT_OK = qw(sorry slurp system_or_die
@@ -217,6 +218,7 @@ sub gen_nqp {
     my $gen_nqp     = $options{'gen-nqp'};
     my $gen_moar    = $options{'gen-moar'};
     my $prefix      = $options{'prefix'} || cwd().'/install';
+    my $sdkroot     = $options{'sdkroot'} || '';
     my $startdir    = cwd();
 
     my $PARROT_REVISION = 'nqp/tools/build/PARROT_REVISION';
@@ -227,7 +229,7 @@ sub gen_nqp {
     for my $b (qw/jvm moar/) {
         if ($backends =~ /$b/) {
             my $postfix = substr $b, 0, 1;
-            my $bin = "$prefix/bin/nqp-$postfix$bat";
+            my $bin = File::Spec->catfile( $sdkroot, $prefix, 'bin', "nqp-$postfix$bat" );
             $impls{$b}{bin} = $bin;
             my %c = read_config($bin);
             my $nqp_have = $c{'nqp::version'} || '';
@@ -280,12 +282,13 @@ sub gen_moar {
     my %options  = @_;
 
     my $prefix     = $options{'prefix'} || cwd()."/install";
+    my $sdkroot    = $options{'sdkroot'} || '';
     my $gen_moar   = $options{'gen-moar'};
     my @opts       = @{ $options{'moar-option'} || [] };
     push @opts, "--optimize";
     my $startdir   = cwd();
 
-    my $moar_exe   = "$prefix/bin/moar$exe";
+    my $moar_exe   = File::Spec->catfile( $sdkroot, $prefix, 'bin', "moar$exe" );
     my $moar_have  = -e $moar_exe ? qx{ $moar_exe --version } : undef;
     if ($moar_have) {
         $moar_have = $moar_have =~ /version (\S+)/ ? $1 : undef;