From 3dc1eb8ca263281baa58d824cfb0b06a75c78002 Mon Sep 17 00:00:00 2001
From: Vincent Bernat <vincent@bernat.im>
Date: Sat, 12 Apr 2014 12:34:28 +0200
Subject: [PATCH] configure: make some flags conditional

Use of _XOPEN_SOURCE is quite dangerous.
---
 configure.ac |  9 +--------
 m4/os.m4     | 17 +++++++++++++++++
 2 files changed, 18 insertions(+), 8 deletions(-)

diff --git a/configure.ac b/configure.ac
index 968c3c84..c312d237 100644
--- a/configure.ac
+++ b/configure.ac
@@ -84,14 +84,7 @@ AX_LDFLAGS_OPTION([-Wl,-z,now])
 
 # OS
 lldp_CHECK_OS
-
-# Additional OS dependents compiler flags. If they cause problem, we
-# can enable them for some OS only.
-AX_CFLAGS_GCC_OPTION([-D_GNU_SOURCE])    dnl GNU systems (asprintf, ...)
-AX_CFLAGS_GCC_OPTION([-D__EXTENSIONS__]) dnl Solaris (CMSG_*)
-AX_CFLAGS_GCC_OPTION([-D_XPG4_2])        dnl Solaris (CMSG_*)
-AX_CFLAGS_GCC_OPTION([-D_XOPEN_SOURCE=500])      dnl HP-UX
-AX_CFLAGS_GCC_OPTION([-D_XOPEN_SOURCE_EXTENDED]) dnl HP-UX
+lldp_CFLAGS_OS
 
 AC_CACHE_SAVE
 
diff --git a/m4/os.m4 b/m4/os.m4
index 584e9d56..f5765d5f 100644
--- a/m4/os.m4
+++ b/m4/os.m4
@@ -31,3 +31,20 @@ AC_DEFUN([lldp_CHECK_OS], [
   fi
   AC_MSG_RESULT([yes ($os)])
 ])
+
+# Enable some additional CFLAGS depending on the OS
+AC_DEFUN([lldp_CFLAGS_OS], [
+  # Most of what we want can be enabled nowadays with _GNU_SOURCE
+  AX_CFLAGS_GCC_OPTION([-D_GNU_SOURCE])    dnl GNU systems (asprintf, ...)
+
+  case $host_os in
+     solaris*)
+       AX_CFLAGS_GCC_OPTION([-D__EXTENSIONS__]) dnl (CMSG_*)
+       AX_CFLAGS_GCC_OPTION([-D_XPG4_2])        dnl (CMSG_*)
+       ;;
+     hpux*)
+       AX_CFLAGS_GCC_OPTION([-D_XOPEN_SOURCE=500])      dnl HP-UX
+       AX_CFLAGS_GCC_OPTION([-D_XOPEN_SOURCE_EXTENDED]) dnl HP-UX
+       ;;
+  esac
+])
-- 
2.39.5