The IDL compiler processes one or more translation units per invocation, producing one or more output files. An invocation of the compiler takes the following form:
ihc [argument...]
where command-line arguments are either options or file names.
All command-line options begin with -. They may not
be grouped: -vO is different from -v -O. Options
need not precede filenames: e.g., ihc *.o -o foo. All options
are processed first and then applied to the input files; you cannot, for
example, invoke ihc -c -g Foo.idl --gc Bar.idl to apply different
backends for the output to be generated for the files Foo.idl and
Bar.idl. For conflicting options, e.g., -c -noC, we
reserve the right to do anything we want. (Usually, the last one
applies).