From c52930d11fcc52515fcc09a1085bf118411566a8 Mon Sep 17 00:00:00 2001
From: Werner Koch <wk@gnupg.org>
Date: Mon, 2 Jan 2017 12:59:10 +0100
Subject: [PATCH] build: Enable gcc warnings to detect non-portable code.

--

Signed-off-by: Werner Koch <wk@gnupg.org>
---
 configure.ac | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/configure.ac b/configure.ac
index 80d977c94..fa206c991 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1574,6 +1574,15 @@ if test "$GCC" = yes; then
         if test x"$_gcc_wopt" = xyes ; then
           mycflags="$mycflags -Wdeclaration-after-statement"
         fi
+
+        AC_MSG_CHECKING([if gcc supports -Wlogical-op and -Wvla])
+        CFLAGS="-Wlogical-op -Wvla"
+        AC_COMPILE_IFELSE([AC_LANG_PROGRAM([],[])],_gcc_wopt=yes,_gcc_wopt=no)
+        AC_MSG_RESULT($_gcc_wopt)
+        if test x"$_gcc_wopt" = xyes ; then
+          mycflags="$mycflags -Wlogical-op -Wvla"
+        fi
+
     else
         mycflags="$mycflags -Wall"
     fi