;;; these structures deal with the compilation system and the unit cache.
 
 ;;; An entry in the unit cache:
 
 (define-struct ucache
   (slots
     (ufile (type string))  ; the name of the file containing the unit definition
     (cifile (type string)) ; the filename of the (compiled) interface file
     (sifile (type string)) ; the filename of the (uncompiled) interface file
     (cfile (type string))  ; the filename of the (compiled) output file
     (sfile (type string))  ; the filename of the (uncompiled) output file
     (udate (type integer))   ; the write date of ufile
     (idate (type integer))   ; the time stamp of the binary interface file
     (stable? (type bool))     ; the stable flag
     (load-prelude? (type bool))  ; true if unit uses standard prelude
     ;; status is initially available (in cache).  It is set to loading when
     ;; requested and loaded once all imported units are loaded.
     (status (type (enum loaded loading available)))
     (ifile-loaded (type bool))  ; true when interface is loaded (modules)
     (code-loaded (type bool))   ; true when the associated code is in memory
     (source-files (type (list string)))  ; source files in the unit
     (imported-units (type (list string))) ; the filenames of imported unit files
     (lisp-files (type (list (tuple string string))))  ; source/binary pairs
     (modules (type (list module)))
     (printers-set? (type bool))
     (printers (type (list symbol)))
     (optimizers-set? (type bool))
     (optimizers (type (list symbol)))
     (chunk-size (type (maybe int)))
     ))
 
 
 ;;; This is used to hold various flags used by the compilation system,
 ;;; instead of passing them all as individual arguments.
 
 (define-struct cflags
   (slots
     ;; Whether to load code for unit into core
     (load-code?           (type bool) (default '#t))
     ;; Whether to create an output code file.
     (write-code?          (type bool) (default '#t))
     ;; Affects whether write-code? creates a source or compiled file,
     ;; and whether load-code? uses the interpreter or compiler.
     ;; Ignored if load-code? and write-code? are both false.
     (compile-code?        (type bool) (default '#t))
     ;; Whether to create an output interface file.
     (write-interface?     (type bool) (default '#t))
     ))