configure.ac: Fix -Wlogical-op test for cifuzz

Report on ./configure warnings in ./get_config.sh

configure.ac

@@ -241,9 +241,12 @@ WARNING_CFLAGS="\
 "
 
 # check whether or not the compiler supports -Wlogical-op (clang does not...)
-AX_CHECK_COMPILE_FLAG([-Wlogical-op], [WARNING_CFLAGS="$WARNING_CFLAGS -Wlogical-op"],,[-Werror])
+# Note oss-fuzz uses clang and adds in option -Wno-error=unknown-warning-option which overrides -Werror
+if test "x$CC" != "xclang"; then
+    AX_CHECK_COMPILE_FLAG([-Wlogical-op], [WARNING_CFLAGS="$WARNING_CFLAGS -Wlogical-op"],,[-Werror])
+fi
 AX_CHECK_COMPILE_FLAG([-fdiagnostics-color], [CFLAGS="$CFLAGS -fdiagnostics-color"],,[-Werror])
-AX_CHECK_COMPILE_FLAG([-Wunused-result], [WARNING_CFLAGS="$WARNING_CFLAGS -Wunused-result"])
+AX_CHECK_COMPILE_FLAG([-Wunused-result], [WARNING_CFLAGS="$WARNING_CFLAGS -Wunused-result"],,[-Werror])
 
 # clang 14+ generates dwarf-5, which is not currently supported by valgrind
 if test "x$CC" = "xclang"; then
@@ -1409,7 +1412,8 @@ libcoap Configuration Summary:
       libcoap ABI version            : "$LIBCOAP_ABI_VERSION"
       libcoap libtool SO version     : "$LIBCOAP_SO_VERSION"
       libcoap DTLS lib extn          : "$LIBCOAP_DTLS_LIB_EXTENSION_NAME"
-      host system                    : "$host"]);
+      host system                    : "$host"
+      compiler                       : "$CC"]);
 if test "x$enable_server_mode" = "xyes"; then
     AC_MSG_RESULT([      build with server support      : "yes"])
 else

get_config.sh

@@ -8,7 +8,8 @@ TAGS=0
 if [ -f config.log ] ; then
   echo "Last ./configure build"
   echo ""
-  cat config.log | grep -E "      libcoap|      host s" | cut -d\  -f7-
+  cat config.log | grep -E "WARNING:" | cut -d\  -f2-
+  cat config.log | grep -E "      libcoap|      host s|      compiler" | cut -d\  -f7-
   cat config.log | grep -E "result:   " | cut -d\  -f3- | cut -d\  -f7-
   echo ""
   TAGS=1