m4_ifdef([AM_SILENT_RULES], [AM_SILENT_RULES([yes])])
# Fill GXX with something before test.
-GXX = "no"
+GXX="no"
# if the user did not provide any CXXFLAGS, we can override them
AS_IF([test "x$CXXFLAGS" = "x" ], [override_cxx=yes], [override_cxx=no])
AS_IF([test "x$CFLAGS" = "x" ], [override_c=yes], [override_c=no])