anchor.diff:  (defmethod perform ((o compile-op) (c c-file))
     (let ((i (first (input-files o c))))
       (destructuring-bind (.o .so) (output-files o c)
  -      (cc-compile .o (list i))
  +      (cc-compile .o (list i) (slot-value c 'cflags))
         (link-shared-library .so (list .o)))))
   
   (defmethod perform ((o load-op) (c c-file))
  
positive.code:   (with-temporary-output (output-file)
      (apply 'invoke `(,@builder ,output-file ,@args))))
  
  (defun cc-compile (output-file inputs)
    (apply 'invoke-builder (list *cc* "-o") output-file
           "-c" (append *cc-flags* #-windows '("-fPIC") inputs)))
  
  (defun link-executable (output-file inputs)
    (apply 'invoke-builder (list *ld* "-o") output-file
  
negative.code:         ((:dll :shared-library) (link-shared-library output inputs))))))
  
  (defclass c-file (source-file)
    ((cflags :initarg :cflags :initform nil)
     (type :initform "c")))
  
  (defmethod output-files ((o compile-op) (c c-file))
  