catch GCC versions that only warn on unused flags

Noticed while building with GCC 4.2 with HP-UX. Switching the ERROR to a
WARN for a first release while we continue to survey the field.

1 files changed, 3 insertions, 3 deletions

diff --git a/configure.ac b/configure.ac
index 2977703..54209da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -104,7 +104,7 @@ AC_DEFUN([CHECK_CFLAG], [
          AC_LANG_ASSERT(C)
          AC_MSG_CHECKING([if $saved_CC supports "$1"])
          old_cflags="$CFLAGS"
-         CFLAGS=$1
+         CFLAGS="$1 -Wall -Werror"
          AC_TRY_LINK([
                       #include <stdio.h>
                       ],
@@ -121,7 +121,7 @@ AC_DEFUN([CHECK_LDFLAG], [
          AC_LANG_ASSERT(C)
          AC_MSG_CHECKING([if $saved_LD supports "$1"])
          old_ldflags="$LDFLAGS"
-         LDFLAGS=$1
+         LDFLAGS="$1 -Wall -Werror"
          AC_TRY_LINK([
                       #include <stdio.h>
                       ],
@@ -151,7 +151,7 @@ AS_IF([test "x$enable_hardening" = "xyes"], [
 AS_IF([test "x$enable_hardening" = "xyes" -a "x$HOST_OS" != "xwin"], [
         CHECK_CFLAG([[-fstack-protector-strong]],
                 CHECK_CFLAG([[-fstack-protector-all]],
-                        AC_MSG_ERROR([compiler does appear to support stack protection - use --disable-hardening to override])
+                        AC_MSG_WARN([compiler does not appear to support stack protection])
                 )
         )
 ])