X-Git-Url: https://www.chiark.greenend.org.uk/ucgi/~ianmdlvl/git?a=blobdiff_plain;f=configure.ac;h=471a6e77db56f726b675cdad6114732c200a4109;hb=147b444d6faa9a621e33d653b7a72c29724203c3;hp=7b06f099e92912622989f51b1f3f4dd8627f2034;hpb=d89426ef1149cdb2e31b48d4ea6f057e1d16fd62;p=secnet.git

diff --git a/configure.ac b/configure.ac
index 7b06f09..471a6e7 100644
--- a/configure.ac
+++ b/configure.ac
@@ -100,6 +100,30 @@ SECNET_C_GETFUNC(inet_aton,resolv)
 AC_CHECK_LIB(adns,adns_init)
 REQUIRE_HEADER([adns.h])
 
+AC_CHECK_FUNCS([fmemopen funopen])
+
+dnl gcc 4.9.2 (jessie) requires -std=gnu11 to cope with for (int i=...
+dnl but we do not want to pass that everywhere because we don't want
+dnl to nail down the C dialect this way.  Why oh why oh why.
+m4_define([for_gcc_std],[
+void x(void) { for (int i=0; i<1; i++) { } }
+])
+AC_CACHE_CHECK([required gcc -std flag],[secnet_cv_gcc_std_flag],[
+    secnet_cv_gcc_std_flag=""
+    AC_COMPILE_IFELSE([AC_LANG_SOURCE(for_gcc_std)],[],[
+        old_cflags="$CFLAGS"
+	CFLAGS="$CFLAGS -std=gnu11"
+	AC_COMPILE_IFELSE([AC_LANG_SOURCE(for_gcc_std)],[
+	    secnet_cv_gcc_std_flag=" -std=gnu11"
+	],[
+	    AC_MSG_RESULT([failure!])
+	    AC_MSG_ERROR([cannot get test program to compile],1)
+	])
+	CFLAGS="$old_cflags"
+    ])
+])
+CFLAGS="$CFLAGS$secnet_cv_gcc_std_flag"
+
 AC_MSG_NOTICE([Checking requirements for IPv6 support...])
 enable_ipv6=true
 m4_define(NO_IPV6,[enable_ipv6=false])