--- c-lex.c.orig 2006-10-18 18:47:45.000000000 -0600 +++ c-lex.c 2007-11-04 16:06:25.000000000 -0700 @@ -149,9 +149,10 @@ cb->read_pch = c_common_read_pch; /* Set the debug callbacks if we can use them. */ - if (debug_info_level == DINFO_LEVEL_VERBOSE - && (write_symbols == DWARF2_DEBUG - || write_symbols == VMS_AND_DWARF2_DEBUG)) + if (flag_syntax_only || + (debug_info_level == DINFO_LEVEL_VERBOSE + && (write_symbols == DWARF2_DEBUG + || write_symbols == VMS_AND_DWARF2_DEBUG))) { cb->define = cb_define; cb->undef = cb_undef;