symtab.lisp

   1 ;;;;------------------------------------------------------------------
   2 ;;;;
   3 ;;;;    Copyright (C) 2000, 2004,
   4 ;;;;    Department of Computer Science, University of Tromso, Norway
   5 ;;;;
   6 ;;;; Filename:      symtab.lisp
   7 ;;;; Description:   Assembly symbolic lookups.
   8 ;;;; Author:        Frode Vatvedt Fjeld <frodef@acm.org>
   9 ;;;; Created at:    Tue Aug 22 10:01:38 2000
  10 ;;;; Distribution:  See the accompanying file COPYING.
  11 ;;;;
  12 ;;;; $Id: symtab.lisp,v 1.3 2004/02/10 00:04:19 ffjeld Exp $
  13 ;;;;
  14 ;;;;------------------------------------------------------------------
  15
  16 (in-package #:ia-x86)
  17
  18 ;;; A symtab is a stack-organized list of "frames", where each frame
  19 ;;; is a hash-table.
  20
  21 (define-condition unresolved-labels ()
  22   ((labels :initarg labels
  23            :reader unresolved-labels-labels))
  24   (:report (lambda (condition stream)
  25              (format stream "Unable to resolve labels ~A."
  26                      (unresolved-labels-labels condition)))))
  27
  28 (defun make-symtab ()
  29   nil)
  30
  31 (defun symtab-add-frame (symtab)
  32   symtab)
  33
  34 (defun symtab-lookup-label (symtab label)
  35   (or (symtab-try-lookup-label symtab label)
  36       (error 'unresolved-labels 'labels (list label))))
  37
  38 (defun symtab-try-lookup-label (symtab label)
  39   (declare (special *symtab-lookup*))
  40   (or (cdr (assoc label symtab))
  41       (if (and (boundp '*symtab-lookup*)
  42                *symtab-lookup*)
  43           (funcall *symtab-lookup* label)
  44         nil)))
  45
  46 (defun symtab-def-label (symtab label value)
  47   (when (symtab-try-lookup-label symtab label)
  48     (error "Label ~A multiply defined." label))
  49   (acons label value symtab))
  50
  51 (defun symtab-collapse-frames (symtab)
  52   symtab)