From 63879e1c82e777d708378fa059e727abcef69d11 Mon Sep 17 00:00:00 2001
From: Florian Forster <octo@leeloo.lan.home.verplant.org>
Date: Tue, 17 Feb 2009 11:29:43 +0100
Subject: [PATCH] build system: Added some serious voodoo to make MakeMaker
 behave.

It is now, at last, possible to build the Perl module before installing
liboping and still have it linked correctly.
---
 bindings/Makefile.am      |  8 ++--
 bindings/perl/Makefile.PL | 93 +++++++++++++++++++++++++++++++++++----
 2 files changed, 88 insertions(+), 13 deletions(-)

diff --git a/bindings/Makefile.am b/bindings/Makefile.am
index 2378c74..0c1c660 100644
--- a/bindings/Makefile.am
+++ b/bindings/Makefile.am
@@ -2,7 +2,7 @@ EXTRA_DIST = perl/Changes perl/MANIFEST perl/META.yml perl/Makefile.PL \
 		perl/Oping.xs perl/README perl/lib/Net/Oping.pm perl/t/Oping.t \
 		perl/typemap
 
-all-local:
+all-local: @BINDINGS@
 	[ ! -f perl/Makefile ] || ( cd perl && $(MAKE) all )
 
 install-exec-local:
@@ -19,6 +19,8 @@ perl: perl-bindings
 perl-bindings: perl/Makefile
 	cd perl && $(MAKE)
 
+# Check if the `perl' directory exists in the _build_ directory. If not, copy
+# the files from the _source_ directory.
 perl/Makefile: perl/Makefile.PL $(top_builddir)/config.status
 	if test ! -d perl; then \
 		for file in $(EXTRA_DIST); do \
@@ -26,9 +28,7 @@ perl/Makefile: perl/Makefile.PL $(top_builddir)/config.status
 			cp $(srcdir)/$$file `dirname $$file`; \
 		done \
 	fi
-	
-	cd perl && @PERL@ Makefile.PL PREFIX=$(prefix) @PERL_BINDINGS_OPTIONS@
-
+	cd perl && @PERL@ Makefile.PL PREFIX="$(prefix)" TOP_BUILDDIR="$(top_builddir)" TARGET_LIBDIR="$(libdir)" @PERL_BINDINGS_OPTIONS@
 
 .PHONY: perl perl-bindings
 
diff --git a/bindings/perl/Makefile.PL b/bindings/perl/Makefile.PL
index 2d272a8..c406112 100644
--- a/bindings/perl/Makefile.PL
+++ b/bindings/perl/Makefile.PL
@@ -1,9 +1,20 @@
 use 5.006;
 use ExtUtils::MakeMaker;
+use Config (%Config);
 
 my @OPING_PREFIX = (qw(/opt/oping /usr /usr/local));
 my $OPING_PREFIX;
 
+my $OPING_CPPFLAGS;
+my $OPING_LDDLFLAGS;
+my $OPING_LIBS;
+
+# TOP_BUILDDIR is set by liboping's build system, so Net::Oping can link with
+# the yet uninstalled library.
+my $TOP_BUILDDIR;
+my $TARGET_LIBDIR;
+
+# Parse custom command line arguments.
 for (my $i = 0; $i < @ARGV; $i++)
 {
 	if ($ARGV[$i] =~ m#^OPING_PREFIX=(.*[^/])#)
@@ -12,21 +23,72 @@ for (my $i = 0; $i < @ARGV; $i++)
 		splice (@ARGV, $i, 1);
 		$i--;
 	}
+	elsif ($ARGV[$i] =~ m#^TOP_BUILDDIR=(.*[^/])#)
+	{
+		$TOP_BUILDDIR = $1;
+		# TOP_BUILDDIR is passed from bindings/, but we're currently in
+		# bindings/perl/. If it is a relative path, we need to add an
+		# extra `../' in order to compensate for this.
+		if ($TOP_BUILDDIR !~ m#^/#)
+		{
+			$TOP_BUILDDIR = "../$TOP_BUILDDIR";
+		}
+		splice (@ARGV, $i, 1);
+		$i--;
+	}
+	elsif ($ARGV[$i] =~ m#^TARGET_LIBDIR=(.*[^/])#)
+	{
+		# Only save TARGET_LIBDIR if it's not a standard system library
+		# directory, such as /usr/lib.
+		if (!is_system_libdir ($1))
+		{
+			$TARGET_LIBDIR = $1;
+		}
+		splice (@ARGV, $i, 1);
+		$i--;
+	}
 }
 
-for (my $i = 0; $i < @OPING_PREFIX; $i++)
+if (!$TOP_BUILDDIR)
 {
-	if (!-e $OPING_PREFIX[$i] . '/include/oping.h')
+	for (my $i = 0; $i < @OPING_PREFIX; $i++)
 	{
-		next;
+		if (!-e $OPING_PREFIX[$i] . '/include/oping.h')
+		{
+			next;
+		}
+
+		$OPING_PREFIX = $OPING_PREFIX[$i];
+		print "Found <oping.h> in $OPING_PREFIX/include\n";
+		last;
 	}
+}
 
-	$OPING_PREFIX = $OPING_PREFIX[$i];
-	print "Found <oping.h> in $OPING_PREFIX/include\n";
-	last;
+if ($TOP_BUILDDIR)
+{
+	# Use LDDLFLAGS here instead of LIBS, because:
+	#  1) We need to make sure our library path comes first (and no locally
+	#     installed version is used).
+	#  2) Prevent MakeMaker from stipping the -rpath option when the
+	#     library is to be installed in a non-standard path. Standard-paths
+	#     are read from $Config{'libsdirs'} above.
+	$OPING_CPPFLAGS = "-I$TOP_BUILDDIR/src";
+	$OPING_LDDLFLAGS = "-L$TOP_BUILDDIR/src/.libs " . $Config{'lddlflags'};
+	$OPING_LIBS = "-L$TOP_BUILDDIR/src/.libs -loping";
+
+	if ($TARGET_LIBDIR)
+	{
+		$OPING_LDDLFLAGS .= qq( -Wl,-rpath -Wl,"$TARGET_LIBDIR");
+	}
+}
+elsif ($OPING_PREFIX)
+{
+	# -rpath is automagically set in this case.
+	$OPING_CPPFLAGS = "-I$OPING_PREFIX/include";
+	$OPING_LIBS = "-L$OPING_PREFIX/lib -loping";
 }
 
-if (!$OPING_PREFIX)
+if (!$OPING_CPPFLAGS)
 {
 	my $search_path = join (', ', @OPING_PREFIX);
 	print STDERR <<EOF;
@@ -60,7 +122,20 @@ WriteMakefile(
      ? (ABSTRACT_FROM => 'lib/Net/Oping.pm',
         AUTHOR        => 'Florian Forster <octo@verplant.org>')
      : ()),
-    LIBS              => ["-L$OPING_PREFIX/lib -loping"],
+    LIBS              => [$OPING_LIBS],
+    ($OPING_LDDLFLAGS ? (LDDLFLAGS => "$OPING_LDDLFLAGS") : ()),
     DEFINE            => '',
-    INC               => "-I$OPING_PREFIX/include"
+    INC               => "$OPING_CPPFLAGS"
 );
+
+sub is_system_libdir
+{
+	my $path = shift;
+	for (split (' ', $Config{'libsdirs'}))
+	{
+		if ($path eq $_)
+		{
+			return (1);
+		}
+	}
+}
-- 
2.30.2