/MAIN_MODULE=module-name
Specifies the main module to be included from the object library
during the Link process. The main module is that defined in the
first source file specified and, by default, the module name is
the same name as the file. This qualifier lets you specify a
module name that is different from the file name. Note that if an
appropriate language-dependent module name directive is detected
within the first source file, the value specified by this
qualifier is ignored.