foreign-parser
On Windows:
""~A" /nologo /E ~A ~{/D~A ~}~{/I"~A" ~}/Tc "~A""
On Unix, Linux and and Mac OS X:
"~A -E ~A ~{-D~A~ ~}~{-I~A ~}~A"
The variable *preprocessor-format-string* provides the default value for the preprocessor-format-string used by process-foreign-file.
*preprocessor-format-string*
*preprocessor-options*process-foreign-file
LispWorks Foreign Language Interface User Guide and Reference Manual - 7 Dec 2011