compile/compiler.lisp

   1 (in-package :as3-compiler)
   2
   3 ;;;
   4 (defclass compiler-context ()
   5   ((class-names :initform () :accessor class-names)
   6    (function-names :initform () :accessor function-names)))
   7
   8 (defparameter *compiler-context* (make-instance 'compiler-context))
   9
  10 ;;; track data about a lambda (or scope in general, defun/let/etc)
  11 ;;;   local variables, etc
  12 (defclass lambda-context ()
  13   ;; using an alist for local name-index mapping, so we can push/pop
  14   ;; state a bit more easily than with hash tables...
  15   ((locals :initform () :accessor locals)))
  16
  17 (defparameter *current-lambda* nil)
  18
  19 (defun make-lambda-context (args)
  20   (let ((lc (make-instance 'lambda-context)))
  21     (push (cons 'this 0) (locals lc))
  22     (loop for i in args
  23        for j from 1
  24        do (push (cons i j) (locals lc)))
  25     (format t "lambda context lc = ~s ~%" (locals lc))
  26     lc))
  27
  28 (defun get-lambda-local-index (name)
  29   (cdr (assoc name (locals *current-lambda*) :test 'string=)))
  30
  31 (defmacro with-lambda-context ((&rest args) &body body)
  32   `(let ((*current-lambda* (make-lambda-context '(,@args))))
  33      ,@body))
  34
  35 ;;; top level (internal?) compiler interface
  36 ;;; returns assembly corresponding to FORM
  37 (defgeneric  scompile (form))
  38
  39 (defmethod scompile ((form string))
  40   `((:push-string ,form)))
  41
  42 (defmethod scompile ((form integer))
  43   ;; possibly should have more control than just assuming anything < 2^31
  44   ;; is int (as well as range checking, etc)
  45   (if (> form (expt 2 31))
  46       `((:push-uint ,form))
  47       `((:push-int ,form))))
  48
  49 (defmethod scompile ((form real))
  50   `((:push-double ,form)))
  51
  52 (defmethod scompile ((form symbol))
  53   (let ((i (get-lambda-local-index form)))
  54     (if i
  55         `((:get-local ,i))
  56         (error "unknown local ~s?" form))))
  57
  58 (defmacro define-constants (&body constants)
  59   `(progn
  60      ,@(loop for i in constants
  61           collect `(defmethod scompile ((form (eql ,(car i))))
  62                      '((,(second i)))))))
  63 (define-constants
  64   (:true :push-true)
  65   (:false :push-false)
  66   (:nan :push-nan)
  67   (:undefined :push-undefined)
  68   (:null :push-null))
  69
  70 ;;; interface for implementing special forms
  71
  72 (defgeneric scompile-cons (car cdr))
  73
  74 (defmethod scompile ((form cons))
  75   (scompile-cons (car form) (cdr form)))
  76
  77 (defmacro define-special (name (&rest args) &body body)
  78   (let ((car (gensym "CAR"))
  79         (cdr (gensym "CDR")))
  80     `(defmethod scompile-cons ((,car (eql ',name)) ,cdr)
  81        (destructuring-bind ,args ,cdr
  82          ,@body))))
  83
  84 #||
  85 (scompile "foo")
  86 (scompile :true)
  87 (scompile 123.45)
  88 ||#