# HG changeset patch
# User Matt Johnston <matt@ucc.asn.au>
# Date 1498224685 -28800
# Node ID 33d90d219e0327ad20e6466fe5f8d46d80f1bcb8
# Parent  a54b22f4058d66e9236f6bccb2f30fdb8f448b9c
Compile with -fno-strict-overflow if possible.
Needed for curve25519-donna https://github.com/agl/curve25519-donna/issues/31

diff -r a54b22f4058d -r 33d90d219e03 configure.ac
--- a/configure.ac	Thu Jun 15 08:00:07 2017 +0800
+++ b/configure.ac	Fri Jun 23 21:31:25 2017 +0800
@@ -9,7 +9,7 @@
 AC_INIT
 AC_CONFIG_SRCDIR(buffer.c)
 
-OLDCFLAGS=$CFLAGS
+OLDCFLAGS="$CFLAGS"
 # Checks for programs.
 AC_PROG_CC
 AC_PROG_MAKE_SET
@@ -24,6 +24,17 @@
 	CFLAGS="-Os -W -Wall -Wno-pointer-sign"
 fi
 
+AC_MSG_CHECKING([if compiler '$CC' supports -fno-strict-overflow])
+OLDCFLAGS="$CFLAGS"
+CFLAGS="$CFLAGS -fno-strict-overflow"
+AC_COMPILE_IFELSE([AC_LANG_PROGRAM([])], 
+    [AC_MSG_RESULT(yes)], 
+    [
+        AC_MSG_RESULT(no)
+        CFLAGS=$OLDCFLAGS
+    ]
+    )
+
 # large file support is useful for scp
 AC_SYS_LARGEFILE