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guile/module/language/objcode/spec.scm
Andy Wingo b41b92c9d1 compilation passes return third value: the continuation environment
* module/system/base/compile.scm: Expect compile passes to produce three
  values, not two. The third is the "continuation environment", the
  environment that can be used to compile a subsequent expression from
  the same source language. For example, expansion-time side effects can
  set the current module, which would be reflected appropriately in the
  continuation environment.

* module/language/assembly/compile-bytecode.scm:
* module/language/bytecode/spec.scm:
* module/language/ecmascript/compile-ghil.scm:
* module/language/ghil/compile-glil.scm:
* module/language/glil/spec.scm:
* module/language/objcode/spec.scm:
* module/language/scheme/compile-ghil.scm:
* module/system/base/compile.scm: Update compile passes to return a
  continuation environment.
2009-04-16 15:20:40 +02:00

100 lines
3.4 KiB
Scheme

;;; Guile Lowlevel Intermediate Language
;; Copyright (C) 2001 Free Software Foundation, Inc.
;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;;
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;; GNU General Public License for more details.
;;
;; You should have received a copy of the GNU General Public License
;; along with this program; see the file COPYING. If not, write to
;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.
;;; Code:
(define-module (language objcode spec)
#:use-module (system base language)
#:use-module (system vm objcode)
#:use-module (system vm program)
#:export (objcode make-objcode-env))
(define (make-objcode-env module externals)
(cons module externals))
(define (objcode-env-module env)
(if env (car env) (current-module)))
(define (objcode-env-externals env)
(if env (cdr env) '()))
(define (objcode->value x e opts)
(let ((thunk (make-program x #f (objcode-env-externals e))))
(if e
(save-module-excursion
(lambda ()
(set-current-module (objcode-env-module e))
(values (thunk) #f e)))
(values (thunk) #f e))))
;; since locals are allocated on the stack and can have limited scope,
;; in many cases we use one local for more than one lexical variable. so
;; the returned locals set is a list, where element N of the list is
;; itself a list of bindings for local variable N.
(define (collapse-locals locs)
(let lp ((ret '()) (locs locs))
(if (null? locs)
(map cdr (sort! ret
(lambda (x y) (< (car x) (car y)))))
(let ((b (car locs)))
(cond
((assv-ref ret (binding:index b))
=> (lambda (bindings)
(append! bindings (list b))
(lp ret (cdr locs))))
(else
(lp (acons (binding:index b) (list b) ret)
(cdr locs))))))))
(define (decompile-value x env opts)
(cond
((program? x)
(let ((objs (program-objects x))
(meta (program-meta x))
(exts (program-external x))
(binds (program-bindings x))
(srcs (program-sources x))
(nargs (arity:nargs (program-arity x))))
(let ((blocs (and binds
(collapse-locals
(append (list-head binds nargs)
(filter (lambda (x) (not (binding:extp x)))
(list-tail binds nargs))))))
(bexts (and binds
(filter binding:extp binds))))
(values (program-objcode x)
`((objects . ,objs)
(meta . ,(and meta (meta)))
(exts . ,exts)
(blocs . ,blocs)
(bexts . ,bexts)
(sources . ,srcs))))))
((objcode? x)
(values x #f))
(else
(error "can't decompile ~A: not a program or objcode" x))))
(define-language objcode
#:title "Guile Object Code"
#:version "0.3"
#:reader #f
#:printer write-objcode
#:compilers `((value . ,objcode->value))
#:decompilers `((value . ,decompile-value))
)