racket/pkgs/compiler-lib/compiler/demodularizer/merge.rkt
2021-04-10 14:55:44 -06:00

206 lines
9.2 KiB
Racket

#lang racket/base
(require compiler/zo-structs
"run.rkt"
"name.rkt"
"import.rkt"
"remap.rkt"
"linklet.rkt")
(provide merge-linklets)
(define (merge-linklets runs names internals lifts imports)
(define (syntax-literals-import? path/submod+phase)
(eq? (cdr path/submod+phase) 'syntax-literals))
(define (transformer-register-import? path/submod+phase)
(eq? (cdr path/submod+phase) 'transformer-register))
;; Pick an order for the remaining imports:
(define import-keys (for/list ([path/submod+phase (in-hash-keys imports)]
;; References to a 'syntax-literals "phase" are
;; references to the implicit syntax-literals
;; module; drop those:
#:unless (or (syntax-literals-import? path/submod+phase)
(transformer-register-import? path/submod+phase)))
path/submod+phase))
(define any-syntax-literals?
(for/or ([path/submod+phase (in-hash-keys imports)])
(syntax-literals-import? path/submod+phase)))
(define any-transformer-registers?
(for/or ([path/submod+phase (in-hash-keys imports)])
(transformer-register-import? path/submod+phase)))
(define syntax-literals-pos 1)
(define transformer-register-pos (+ (if any-syntax-literals? 1 0)
syntax-literals-pos))
(define import-counter (+ (if any-transformer-registers? 1 0)
transformer-register-pos))
;; Map each remaining import to its position, meanwhile getting a list
;; of lists of external--internal name lists
(define ordered-importss
(for/list ([key (in-list import-keys)])
(define ordered-imports (hash-ref imports key))
(for/list ([name (in-list ordered-imports)])
(define i (hash-ref names (cons key name)))
(set-import-pos! i import-counter)
(set! import-counter (add1 import-counter))
(list name (import-int-name i)))))
;; Keep all the same import shapes
(define import-shapess
(for/list ([key (in-list import-keys)])
(for/list ([name (in-list (hash-ref imports key))])
(import-shape (hash-ref names (cons key name))))))
;; Map all syntax-literal references to the same import.
;; We could update each call to the access to use a suitable
;; vector index.
(for ([(path/submod+phase imports) (in-hash imports)]
#:when (syntax-literals-import? path/submod+phase)
[name (in-list imports)])
(define i (hash-ref names (cons path/submod+phase name)))
(set-import-pos! i syntax-literals-pos))
;; Map the transformer-register import, if any
(let* ([path/submod+phase '(#%transformer-register . transformer-register)]
[imports (hash-ref imports path/submod+phase null)])
(for ([name (in-list imports)])
(define i (hash-ref names (cons path/submod+phase name)))
(set-import-pos! i transformer-register-pos)))
;; Map internals and lifts to positions
(define first-internal-pos import-counter)
(define new-internals (make-hasheq))
(define positions
(for/hash ([name (in-list (append internals lifts))]
[i (in-naturals first-internal-pos)])
(hash-set! new-internals name #t)
(values name i)))
;; For each linklet that we merge, make a mapping from
;; the linklet's old position to new names (which can
;; then be mapped to new positions):
(define (make-position-mapping r)
(define h (make-hasheqv))
(define p (make-hasheq))
(define linkl (run-linkl r))
(define importss (linklet*-importss linkl))
(define internal-importss (linklet*-internal-importss linkl))
(define pos 1)
(for ([imports (in-list importss)]
[internal-imports (in-list internal-importss)]
[use (in-list (run-uses r))])
(for ([name (in-list imports)]
[internal-name (in-list internal-imports)])
(hash-set! h pos (find-name names use name))
(hash-set! p internal-name pos)
(set! pos (add1 pos))))
(define path/submod+phase (cons (run-path/submod r) (run-phase r)))
(define internal-names (append (linklet*-internals linkl)
(linklet*-lifts linkl)))
(for ([name (in-list (append (linklet*-exports linkl)
internal-names))]
[internal-name (in-list (append (linklet*-internal-exports linkl)
internal-names))]
[pos (in-naturals pos)])
(hash-set! h pos (find-name names path/submod+phase name))
(hash-set! p internal-name pos))
(values h p))
;; Do we need the implicit initial variable for `(#%variable-reference)`?
;; The slot will be reserved whether we use it or not, but the
;; slot is not necessarily initialized if we don't need it.
(define saw-zero-pos-toplevel? #f)
(define linkl-mode #f)
(define body
(apply
append
(for/list ([r (in-list runs)])
(define-values (pos-to-name/import local-name-to-pos) (make-position-mapping r))
(define linkl (run-linkl r))
(cond
[(linkl? linkl)
(define (remap-toplevel-pos pos)
(cond
[(zero? pos)
;; Implicit variable for `(#%variable-reference)` stays in place:
(set! saw-zero-pos-toplevel? #t)
0]
[else
(define new-name/import (hash-ref pos-to-name/import pos))
(if (import? new-name/import)
(import-pos new-name/import)
(hash-ref positions new-name/import))]))
(when (eq? linkl-mode 's-exp) (error 'demosularize "inconsistent linklet representations"))
(set! linkl-mode 'linkl)
(remap-positions (linkl-body linkl)
remap-toplevel-pos
#:application-hook
(lambda (rator rands remap)
;; Check for a `(.get-syntax-literal! '<pos>)` call
;; or a `(.set-transformer! '<sym> <expr>)` call
(cond
[(and (toplevel? rator)
(let ([i (hash-ref pos-to-name/import (toplevel-pos rator))])
(and (import? i)
i)))
=> (lambda (i)
(cond
[(and any-syntax-literals?
(eqv? syntax-literals-pos (import-pos i)))
;; This is a `(.get-syntax-literal! '<pos>)` call
(application (remap rator)
;; To support syntax objects, change the offset
rands)]
[(and any-transformer-registers?
(eqv? transformer-register-pos (import-pos i)))
;; This is a `(.set-transformer! '<sym> <expr>)` call
(void)]
[else #f]))]
[else #f])))]
[(linklet*-body linkl)
=> (lambda (body)
(when (eq? linkl-mode 'linkl) (error 'demosularize "inconsistent linklet representations"))
(set! linkl-mode 's-exp)
;; We can work in terms of names instead of positions
(define importss (linklet*-importss linkl))
(define (remap-name name)
(define pos (hash-ref local-name-to-pos name #f))
(cond
[(not pos) ; => primitive
name]
[else
(define n (hash-ref pos-to-name/import pos))
(cond
[(import? n) (import-int-name n)]
[else n])]))
(remap-names body
remap-name
#:application-hook
(lambda (rator rands remap)
;; Check for a `(.get-syntax-literal! '<pos>)` call
;; or a `(.set-transformer! '<sym> <expr>)` call
(cond
[(eq? rator '.get-syntax-literal!)
`(,(remap rator)
;; To support syntax objects, change the offset
,@rands)]
[(eq? rator '.set-transformer!)
'(void)]
[else #f]))))]))))
(values body
first-internal-pos
new-internals
linkl-mode
;; Communicates into to `wrap-bundle`:
(lambda ()
(values runs
import-keys
ordered-importss
import-shapess
any-syntax-literals?
any-transformer-registers?
saw-zero-pos-toplevel?))))