scsh-0.5/link/reify.scm

282 lines
7.8 KiB
Scheme

; Copyright (c) 1993, 1994 Richard Kelsey and Jonathan Rees. See file COPYING.
; Structure reification.
(define *least* #f)
(define (reify-structures some)
(let* ((count 0)
(least 1000000)
(greatest -1000000)
(locs (make-table))
(loser (reify-structures-1 some
(lambda (loc)
(let ((id (location-id loc)))
(if (not (table-ref locs id))
(begin
(if (< id least)
(set! *least* loc))
(set! least (min least id))
(set! greatest (max greatest id))
(set! count (+ count 1))
(table-set! locs id loc)))
id))))
(size (+ (- greatest least) 1)))
(write `(least ,least size ,size count ,count)) (newline)
(values loser
(let ((v (make-vector size #f)))
(table-walk (lambda (id loc)
(vector-set! v (- id least) loc))
locs)
v)
least)))
; This is pretty gross. We really want some kind of object dumper
; instead.
(define *objects* '()) ;List of (object . creation-form)
(define *object-count* 0)
(define *initializations* '())
(define *deal-with-location* (lambda (loc) loc))
(define *package-table* #f) ;Entries are package-info structures
; REIFY-STRUCTURES returns a form that evaluates to a procedure that
; returns an alist of (name . structure). deal-with-location is a
; procedure that maps locations to labels for them (e.g. integers).
; The procedure takes one argument, a procedure that will be applied
; to the labels at startup time to re-obtain the corresponding
; locations.
(define (reify-structures-1 alist deal-with-location)
(flush-state)
(set! *deal-with-location* deal-with-location)
(display "Reifying") (force-output (current-output-port))
(let* ((result-form (reify-object alist))
(shebang
`(lambda (get-location)
(let ((the-objects (make-vector ,*object-count* #f)))
(begin ,@(map (lambda (init) (init))
(reverse *initializations*)))
(let ((structs ,result-form))
(set! the-objects #f) ;SO IT CAN BE GC'D
(set! get-location #f)
structs)))))
(newline)
(if *reify-debug* (*reify-debug* shebang))
(flush-state)
(set! *deal-with-location* (lambda (loc) loc))
shebang))
(define (flush-state)
(set! *objects* '())
(set! *object-count* 0)
(set! *initializations* '())
(set! *package-table* (make-table package-uid)))
; Return an expression that will evaluate to thing.
(define (reify-object thing)
(cond ((structure? thing)
(let ((p-form (reify-package (structure-package thing))))
(process-one-object
thing
(lambda ()
`(make-structure
,p-form
,(interface-expression thing)
',(structure-name thing)))
(lambda ()
(process-exports thing p-form)
(write-char #\.)
(force-output (current-output-port))))))
((null? thing) ''())
((pair? thing)
(if (list? thing)
`(list ,@(map reify-object thing))
`(cons ,(reify-object (car thing))
,(reify-object (cdr thing)))))
((symbol? thing)
`',thing)
((transform? thing)
(process-transform thing))
((operator? thing)
`(operator ',(operator-name thing)
',(type->sexp (operator-type thing) #t)))
;; ((interface? thing) ...)
(else (error "don't know how to reify this" thing))))
(define (reify-package thing)
(process-one-object thing
(lambda ()
(let ((bindings (package-info-bindings (package-info thing))))
`(package
;; Each binding is a pair (name . loc)
',(list->vector (map car bindings)) ;names
',(list->vector (map cdr bindings)) ;location ids
get-location
,(package-uid thing))))
(lambda ()
(table-set! *package-table*
thing
(make-package-info)))))
; General utility for uniquifying objects.
(define (process-one-object obj make-creation-form when-new)
(let ((probe (assq obj *objects*)))
(if probe
(cdr probe)
(let* ((index *object-count*)
(form `(vector-ref the-objects ,index)))
(set! *object-count* (+ *object-count* 1))
(set! *objects*
(cons (cons obj form) *objects*))
(add-initialization!
(lambda ()
`(vector-set! the-objects ,index ,(make-creation-form))))
(when-new)
form))))
(define (add-initialization! thunk)
(set! *initializations*
(cons thunk *initializations*)))
; Add initializers that will create a structure's exported bindings.
(define (process-exports struct p-form)
(let* ((p (structure-package struct))
(info (package-info p)))
(for-each-export (lambda (name want-type binding)
(if (not (process-one-binding name p info p-form))
(warn "undefined export" name p)))
struct)))
; Packages...
(define package-info-type
(make-record-type 'reify-info
'(bindings ;List of (name static-info location)
table))) ;Caches (assq? name bindings)
(define (package-info p)
(table-ref *package-table* p))
(define make-package-info
(let ((make (record-constructor package-info-type
'(bindings table))))
(lambda ()
(make '()
(make-table name-hash)))))
(define package-info-bindings (record-accessor package-info-type 'bindings))
(define package-info-table (record-accessor package-info-type 'table))
(define set-package-info-bindings!
(record-modifier package-info-type 'bindings))
(define (process-one-binding name p info p-form) ; => #t iff bound
(let ((table (package-info-table info)))
(if (table-ref table name)
#t
(let ((binding (package-lookup p name)))
(table-set! (package-info-table info) name #t)
(if (binding? binding)
(begin (really-process-one-binding name info binding p-form)
#t)
#f)))))
(define (really-process-one-binding name info binding p-form)
(let ((static (binding-static binding))
(loc (*deal-with-location* (binding-place binding))))
(set-package-info-bindings!
info
(cons (cons name loc)
(package-info-bindings info)))
(if static
(add-package-define! p-form name (reify-object static)))))
(define (add-package-define! p-form name s-form)
(add-initialization!
(lambda ()
`(package-define! ,p-form
',name
,s-form))))
(define (process-transform t)
(let ((name (transform-id t))
(env (transform-env t)))
(let ((env-form
(if (package? env)
(reify-package env)
(reify-object env))))
(process-one-object
t
(let ((source (transform-source t)))
(lambda ()
`(transform ,source ;transformer
,env-form
',(type->sexp (transform-type t) #t) ;type
#f ;',source -- omitted to save space...
',name)))
(if (package? env)
(lambda ()
(let ((info (package-info env)))
(for-each (lambda (name)
(process-one-binding name env info env-form))
(or (transform-aux-names t) ; () must be true
(begin
(warn "reified macro's auxiliary bindings are unknown"
name)
'())))))
(lambda () #f))))))
(define (interface-expression struct)
(let ((names '())
(types '()))
(for-each-export (lambda (name type binding)
(set! names (cons name names))
(set! types (cons (if (eq? type undeclared-type)
':undeclared
(type->sexp type #t))
types)))
struct)
`(simple-interface ',(list->vector names) ',(list->vector types))))
; The compiler doesn't like to see unusual objects quoted, but this will
; fake it out.
(define strange-quotation
(let ((operator/literal (get-operator 'literal)))
(define (normal? thing)
(or (number? thing)
(and (vector? thing)
(every normal? (vector->list thing)))))
(lambda (thing)
(if (normal? thing)
`',thing
(make-node operator/literal thing)))))
(define *reify-debug* ;#f
(let ((fn "reify-debug.tmp"))
(lambda (x) (call-with-output-file fn
(lambda (port)
(display "Writing linker debug file ")
(display fn) (force-output (current-output-port))
(write x port)
(newline))))))