racket/collects/compiler/demodularizer/merge.rkt
2011-06-28 02:01:41 -04:00

174 lines
7.4 KiB
Racket

#lang racket
(require compiler/zo-parse
"util.rkt"
"mpi.rkt"
"nodep.rkt"
"update-toplevels.rkt")
(define MODULE-TOPLEVEL-OFFSETS (make-hash))
(define current-get-modvar-rewrite (make-parameter #f))
(define (merge-compilation-top get-modvar-rewrite top)
(parameterize ([current-get-modvar-rewrite get-modvar-rewrite])
(match top
[(struct compilation-top (max-let-depth prefix form))
(define-values (new-max-let-depth new-prefix gen-new-forms)
(merge-form max-let-depth prefix form))
(define total-tls (length (prefix-toplevels new-prefix)))
(define total-stxs (length (prefix-stxs new-prefix)))
(define total-lifts (prefix-num-lifts new-prefix))
(log-debug (format "max-let-depth ~S to ~S" max-let-depth new-max-let-depth))
(log-debug (format "total toplevels ~S" total-tls))
(log-debug (format "total stxs ~S" total-stxs))
(log-debug (format "num-lifts ~S" total-lifts))
(make-compilation-top
new-max-let-depth new-prefix
(make-splice (gen-new-forms new-prefix)))]
[else (error 'merge "unrecognized: ~e" top)])))
(define (merge-forms max-let-depth prefix forms)
(if (empty? forms)
(values max-let-depth prefix (lambda _ empty))
(let*-values ([(fmax-let-depth fprefix gen-fform) (merge-form max-let-depth prefix (first forms))]
[(rmax-let-depth rprefix gen-rforms) (merge-forms fmax-let-depth fprefix (rest forms))])
(values rmax-let-depth
rprefix
(lambda args
(append (apply gen-fform args)
(apply gen-rforms args)))))))
(define (merge-form max-let-depth prefix form)
(match form
[(? mod?)
(merge-module max-let-depth prefix form)]
[(struct seq (forms))
(merge-forms max-let-depth prefix forms)]
[(struct splice (forms))
(merge-forms max-let-depth prefix forms)]
[else
(values max-let-depth prefix (lambda _ (list form)))]))
(define (merge-prefix root-prefix mod-prefix)
(match root-prefix
[(struct prefix (root-num-lifts root-toplevels root-stxs))
(match mod-prefix
[(struct prefix (mod-num-lifts mod-toplevels mod-stxs))
(make-prefix (+ root-num-lifts mod-num-lifts)
(append root-toplevels mod-toplevels)
(append root-stxs mod-stxs))])]))
(define (compute-new-modvar mv rw)
(match mv
[(struct module-variable (modidx sym pos phase))
(match rw
[(struct modvar-rewrite (self-modidx provide->toplevel))
(log-debug (format "Rewriting ~a of ~S" pos (mpi->path* modidx)))
((hash-ref MODULE-TOPLEVEL-OFFSETS self-modidx
(lambda ()
(error 'compute-new-modvar "toplevel offset not yet computed: ~S" self-modidx)))
(provide->toplevel sym pos))])]))
(define (filter-rewritable-module-variable? toplevel-offset mod-toplevels)
(define-values
(i new-toplevels remap)
(for/fold ([i 0]
[new-toplevels empty]
[remap empty])
([tl (in-list mod-toplevels)])
(match tl
[(and mv (struct module-variable (modidx sym pos phase)))
(define rw ((current-get-modvar-rewrite) modidx))
; XXX We probably don't need to deal with #f phase
(unless (or (not phase) (zero? phase))
(error 'eliminate-module-variables "Non-zero phases not supported: ~S" mv))
(cond
; Primitive module like #%paramz
[(symbol? rw)
(log-debug (format "~S from ~S" sym rw))
(values (add1 i)
(list* tl new-toplevels)
(list* (+ i toplevel-offset) remap))]
[(module-path-index? rw)
(values (add1 i)
(list* tl new-toplevels)
(list* (+ i toplevel-offset) remap))]
[(modvar-rewrite? rw)
(values i
new-toplevels
(list* (compute-new-modvar mv rw) remap))]
[else
(error 'filter-rewritable-module-variable? "Unsupported module-rewrite: ~S" rw)])]
[tl
(values (add1 i)
(list* tl new-toplevels)
(list* (+ i toplevel-offset) remap))])))
; XXX This would be more efficient as a vector
(values (reverse new-toplevels)
(reverse remap)))
(define (merge-module max-let-depth top-prefix mod-form)
(match mod-form
[(struct mod (name srcname self-modidx mod-prefix provides requires body syntax-body unexported mod-max-let-depth dummy lang-info internal-context))
(define toplevel-offset (length (prefix-toplevels top-prefix)))
(define topsyntax-offset (length (prefix-stxs top-prefix)))
(define lift-offset (prefix-num-lifts top-prefix))
(define mod-toplevels (prefix-toplevels mod-prefix))
(define-values (new-mod-toplevels toplevel-remap) (filter-rewritable-module-variable? toplevel-offset mod-toplevels))
(define num-mod-toplevels
(length toplevel-remap))
(define mod-stxs
(length (prefix-stxs mod-prefix)))
(define mod-num-lifts
(prefix-num-lifts mod-prefix))
(define new-mod-prefix
(struct-copy prefix mod-prefix
[toplevels new-mod-toplevels]))
(hash-set! MODULE-TOPLEVEL-OFFSETS self-modidx
(lambda (n)
(list-ref toplevel-remap n)))
(unless (= (length toplevel-remap)
(length mod-toplevels))
(error 'merge-module "Not remapping everything: ~S ~S"
mod-toplevels toplevel-remap))
(log-debug (format "[~S] Incrementing toplevels by ~a"
name
toplevel-offset))
(log-debug (format "[~S] Incrementing lifts by ~a"
name
lift-offset))
(log-debug (format "[~S] Filtered mod-vars from ~a to ~a"
name
(length mod-toplevels)
(length new-mod-toplevels)))
(values (max max-let-depth mod-max-let-depth)
(merge-prefix top-prefix new-mod-prefix)
(lambda (top-prefix)
(log-debug (format "[~S] Updating top-levels" name))
(define top-lift-start (prefix-lift-start top-prefix))
(define mod-lift-start (prefix-lift-start mod-prefix))
(define total-lifts (prefix-num-lifts top-prefix))
(define max-toplevel (+ top-lift-start total-lifts))
(define update
(update-toplevels
(lambda (n)
(cond
[(mod-lift-start . <= . n)
; This is a lift
(local [(define which-lift (- n mod-lift-start))
(define lift-tl (+ top-lift-start lift-offset which-lift))]
(when (lift-tl . >= . max-toplevel)
(error 'merge-module "[~S] lift error: orig(~a) which(~a) max(~a) lifts(~a) now(~a)"
name n which-lift num-mod-toplevels mod-num-lifts lift-tl))
lift-tl)]
[else
(list-ref toplevel-remap n)]))
(lambda (n)
(+ n topsyntax-offset))
(prefix-syntax-start top-prefix)))
(map update body)))]))
(provide/contract
[merge-compilation-top (-> get-modvar-rewrite/c
compilation-top?
compilation-top?)])