R:\>wcl386 foobarfoobarfoobar.cpp
Open Watcom C/C++32 Compile and Link Utility Version 1.8
Portions Copyright (c) 1988-2002 Sybase, Inc. All Rights Reserved.
Source code is available under the Sybase Open Watcom Public License.
See http://www.openwatcom.org/ for details.
Unable to open "foobarfoobarfoobar.cpp"
やはり長いとコンパイルエラーになりますね。