The Foreign Parser requires a C preprocessor, so you must have a suitable preprocessor installed on your machine.
By default LispWorks invokes
cl.exe
(VC++) on Windows and
cc
on other platforms. If you have this installed, then make sure it is on your PATH.
On Windows, if you don't have
cl.exe
, download the VC++ toolkit from Microsoft
Preprocessors known to work with LispWorks are:
To use a preprocessor other than the default, set the variable
foreign-parser:*preprocessor*
, for example:
(setf foreign-parser:*preprocessor* "gcc")