simple.jas

《java virtual machine》是研究jvm的一本书

;; script to create a class that does nothing.


                                        ; make-class-env creates
                                        ; a ClassEnv object which is
                                        ; used to store information about
                                        ; an object.
(define my-class (make-class-env))

                                        ; make-code creates a code object
                                        ; which contains the body of a
                                        ; method.

(define init-code (make-code))
(jas-code-addinsn init-code
                  (aload_0))
(jas-code-addinsn init-code
                  (invokenonvirtual
                   (make-method-cpe "java/lang/Object" "<init>" "()V")))
(jas-code-addinsn init-code
                  (return))

                                        ; fill up the class with goodies
(jas-class-setsuperclass my-class (make-class-cpe "java/lang/Object"))
(jas-class-setclass my-class (make-class-cpe "out"))
(jas-class-setaccess my-class acc-public)
(jas-class-addmethod my-class acc-public "<init>" "()V" init-code ())

                                        ; and write it all out
(jas-class-write my-class (make-outputstream "out.class"))