From 037645b13aeb23c64d06776c679cb3d2b73a2235 Mon Sep 17 00:00:00 2001
From: Sebastian Harl <sh@tokkee.org>
Date: Mon, 2 Feb 2009 11:28:43 +0000
Subject: [PATCH] build system: Check for and work-around broken
 Perl_load_module().

Configure now checks for a broken Perl_load_module() definition as introduced
in Perl 5.10 which incorrectly uses __attribute__nonnull__(3). If that has been
detected, the perl plugin will now be built using -Wno-nonnull, thus ignoring
the warning / error produced by the nonnull attribute.

References: #41
Resolves: #42
---
 configure.in    | 37 +++++++++++++++++++++++++++++++++++++
 src/Makefile.am |  5 +++++
 2 files changed, 42 insertions(+)

diff --git a/configure.in b/configure.in
index c86b7114..18a83b08 100644
--- a/configure.in
+++ b/configure.in
@@ -1949,6 +1949,43 @@ then
 	CFLAGS=$SAVE_CFLAGS
 	LDFLAGS=$SAVE_LDFLAGS
 fi
+
+if test "x$with_libperl" = "xyes"
+then
+	SAVE_CFLAGS=$CFLAGS
+	SAVE_LDFLAGS=$LDFLAGS
+	# trigger an error if Perl_load_module*() uses __attribute__nonnull__(3)
+	# (see issues #41 and #42)
+	CFLAGS="$CFLAGS $PERL_CFLAGS -Wall -Werror"
+	LDFLAGS="$LDFLAGS $PERL_LDFLAGS"
+
+	AC_CACHE_CHECK([for broken Perl_load_module()],
+		[have_broken_perl_load_module],
+		AC_LINK_IFELSE(
+			AC_LANG_PROGRAM(
+			[[
+#define PERL_NO_GET_CONTEXT
+#include <EXTERN.h>
+#include <perl.h>
+#include <XSUB.h>
+			]],
+			[[
+			 dTHX;
+			 load_module (PERL_LOADMOD_NOIMPORT,
+			     newSVpv ("Collectd::Plugin::FooBar", 24),
+			     Nullsv);
+			]]),
+			[have_broken_perl_load_module="no"],
+			[have_broken_perl_load_module="yes"]
+		)
+	)
+
+	AM_CONDITIONAL(HAVE_BROKEN_PERL_LOAD_MODULE,
+			test "x$have_broken_perl_load_module" = "xyes")
+
+	CFLAGS=$SAVE_CFLAGS
+	LDFLAGS=$SAVE_LDFLAGS
+fi
 # }}}
 
 # --with-libpq {{{
diff --git a/src/Makefile.am b/src/Makefile.am
index 26db76db..935ed7b5 100644
--- a/src/Makefile.am
+++ b/src/Makefile.am
@@ -604,6 +604,11 @@ perl_la_CPPFLAGS = $(AM_CPPFLAGS) -DHAS_BOOL=1
 perl_la_CFLAGS  = $(AM_CFLAGS) \
 		$(PERL_CFLAGS) \
 		-DXS_VERSION=\"$(VERSION)\" -DVERSION=\"$(VERSION)\"
+# Work-around for issues #41 and #42 - Perl 5.10 incorrectly introduced
+# __attribute__nonnull__(3) for Perl_load_module().
+if HAVE_BROKEN_PERL_LOAD_MODULE
+perl_la_CFLAGS += -Wno-nonnull
+endif
 perl_la_LDFLAGS = -module -avoid-version \
 		$(PERL_LDFLAGS)
 collectd_LDADD += "-dlopen" perl.la
-- 
2.11.0