From 7c462ed478f49c791265e525d69a98dc33a13aa0 Mon Sep 17 00:00:00 2001 From: Stephen Adams Date: Mon, 4 Mar 1996 05:10:46 +0000 Subject: [PATCH] . Changed environment data structures to use a hash-table. Makes little difference to small programs but speeds up compilation of big programs/procedures. . Added a comment to explaind the wierd %make-stack-closure stuff. . Fixed typo in STRING->SYMBOL constant-folder. . The rewrite for NOT is now more `recursive', i.e. it propagates the injection of a NOT deeper. --- v8/src/compiler/midend/cleanup.scm | 477 ++++++++++++----------------- 1 file changed, 195 insertions(+), 282 deletions(-) diff --git a/v8/src/compiler/midend/cleanup.scm b/v8/src/compiler/midend/cleanup.scm index f6dda0e1c..239bf174b 100644 --- a/v8/src/compiler/midend/cleanup.scm +++ b/v8/src/compiler/midend/cleanup.scm @@ -1,8 +1,8 @@ #| -*-Scheme-*- -$Id: cleanup.scm,v 1.27 1995/11/28 17:43:59 adams Exp $ +$Id: cleanup.scm,v 1.28 1996/03/04 05:10:46 adams Exp $ -Copyright (c) 1994-1995 Massachusetts Institute of Technology +Copyright (c) 1994-1996 Massachusetts Institute of Technology This material was developed by the Scheme project at the Massachusetts Institute of Technology, Department of Electrical Engineering and @@ -32,8 +32,11 @@ Technology nor of any adaptation thereof in any advertising, promotional, or sales literature without prior written consent from MIT in each case. |# -;;;; Rename to avoid conflict, substitute parameters, etc. ;;; package: (compiler midend) +;; +;; . Second half of beta substitution: substitute parameters at calls to +;; known procedures. +;; . Constant folding (and rewrites on commutivity / associativity). (declare (usual-integrations)) @@ -45,10 +48,9 @@ MIT in each case. |# (call-with-values (lambda () (%matchup (cdr bindings) '(handler env) '(cdr form))) (lambda (names code) - `(DEFINE ,proc-name + `(DEFINE (,proc-name ENV FORM) (LET ((HANDLER (LAMBDA ,(cons (car bindings) names) ,@body))) - (NAMED-LAMBDA (,proc-name ENV FORM) - (CLEANUP/REMEMBER ,code FORM)))))))) + (CLEANUP/REMEMBER ,code FORM))))))) (define-cleanup-handler LOOKUP (env name) (let ((value (cleanup/env/lookup name env))) @@ -57,26 +59,33 @@ MIT in each case. |# (form/copy value)))) (define-cleanup-handler LAMBDA (env lambda-list body) - (let ((renames (cleanup/renamings env (lambda-list->names lambda-list)))) - `(LAMBDA ,(map (lambda (token) - (cleanup/rename renames token)) - lambda-list) - ,(cleanup/expr (cleanup/env/extend env renames) body)))) + (define (exit! name) (cleanup/env/exit! env name)) + (let ((lambda-list* + (map (lambda (name) + (if (memq name '(#!AUX #!REST #!OPTIONAL)) + name + (cleanup/binding/name (cleanup/env/enter! env name)))) + lambda-list))) + (let ((body* (cleanup/expr env body))) + (for-each exit! (lambda-list->names lambda-list)) + `(LAMBDA ,lambda-list* ,body*)))) (define-cleanup-handler LETREC (env bindings body) - (do-letrec-cleanup env bindings body)) - -(define (do-letrec-cleanup env bindings body) - (let* ((renames (cleanup/renamings env (map car bindings))) - (env* (cleanup/env/extend env renames)) - (body* (cleanup/expr env* body))) - (if (null? bindings) - body* - `(LETREC ,(map (lambda (binding) - (list (cleanup/rename renames (car binding)) - (cleanup/expr env* (cadr binding)))) - bindings) - ,body*)))) + (define (enter! binding) (cleanup/env/enter! env (car binding))) + (define (exit! binding) (cleanup/env/exit! env (car binding))) + (let ((bindings* (map enter! bindings))) + (let ((body* (cleanup/expr env body))) + (let ((result + (if (null? bindings) + body* + `(LETREC ,(map (lambda (binding binding*) + (list (cleanup/binding/name binding*) + (cleanup/expr env (second binding)))) + bindings + bindings*) + ,body*)))) + (for-each exit! bindings) + result)))) (define-cleanup-handler QUOTE (env object) env ; ignored @@ -85,6 +94,12 @@ MIT in each case. |# (define-cleanup-handler DECLARE (env #!rest anything) env ; ignored `(DECLARE ,@anything)) + +(define-cleanup-handler BEGIN (env #!rest actions) + (beginnify (cleanup/expr* env actions) #T)) + +(define-cleanup-handler LET (env bindings body) + (cleanup/let* cleanup/letify env bindings body)) (define-cleanup-handler IF (env pred conseq alt) (cleanup/if/un-not env pred conseq alt #T)) @@ -118,12 +133,6 @@ MIT in each case. |# (form/simple&side-effect-free? pred*)) pred*) (else (default))))) - -(define-cleanup-handler BEGIN (env #!rest actions) - (beginnify (cleanup/expr* env actions) #T)) - -(define-cleanup-handler LET (env bindings body) - (cleanup/let* cleanup/letify env bindings body)) (define-cleanup-handler CALL (env rator cont #!rest rands) (define (default) @@ -147,69 +156,45 @@ MIT in each case. |# (if (equal? cont* '(QUOTE #F)) result `(CALL (QUOTE ,%invoke-continuation) ,cont* ,result))) - (call-with-values - (lambda () - (cond ((eq? rator-name %invoke-remote-cache) - (let ((descriptor (quote/text (car rands*)))) - (values (first descriptor) - (second descriptor) - (cddr rands*)))) - (else - (values rator-name (length rands*) rands*)))) - (lambda (operator arity rands**) - (cond ((cleanup/rewrite? operator arity) - => (lambda (handler) - (cond ((apply handler rands**) - => use-result) - (else (default))))) - (else (default))))))) + (define (try-op operator arity rands**) + (cond ((cleanup/rewrite? operator arity) + => (lambda (handler) + (cond ((apply handler rands**) + => use-result) + (else (default))))) + (else (default)))) + (if (eq? rator-name %invoke-remote-cache) + (let ((descriptor (quote/text (car rands*)))) + (try-op (first descriptor) (second descriptor) (cddr rands*))) + (try-op rator-name (length rands*) rands*)))) ((LAMBDA/? rator) (let ((lambda-list (lambda/formals rator)) (lambda-body (lambda/body rator))) (define (generate env let-names let-values) + ;;(pp ` (generate ,env ,let-names ,let-values)) (cleanup/let* (lambda (bindings* body*) (cleanup/pseudo-letify rator bindings* body*)) env - (cleanup/bindify let-names let-values) + (cleanup/lambda-list->bindings let-names let-values) lambda-body)) - #| ; - (define (build-call-lambda/try1 new-cont-var body closure) ; - `(CALL (LAMBDA (,new-cont-var) ,body) ,closure)) - |# - (define (build-call-lambda/try2 new-cont-var body closure) - ;; We can further reduce one special case: when the body is an - ;; invoke-continuation and the stack closure is a real - ;; continuation (not just a push) - (if (and (CALL/%invoke-continuation? body) - (LOOKUP/? (CALL/%invoke-continuation/cont body)) - (eq? new-cont-var - (LOOKUP/name (CALL/%invoke-continuation/cont body))) - (CALL/%make-stack-closure? closure) - (LAMBDA/? - (CALL/%make-stack-closure/lambda-expression closure))) - `(CALL (QUOTE ,%invoke-continuation) - ,closure - ,@(CALL/%invoke-continuation/values body)) - (let ((new-lambda `(LAMBDA (,new-cont-var) ,body))) - (cleanup/remember new-lambda rator) - `(CALL ,new-lambda ,closure)))) + (if (call/%make-stack-closure? cont) ;; Cannot substitute a make-stack-closure because both pushing - ;; and poping have to be kept in the right order. - (let* ((old-cont-var (car lambda-list)) - (new-cont-var (variable/rename old-cont-var)) - (new-env - (cleanup/env/extend - env - (list (cleanup/binding/make old-cont-var - `(LOOKUP ,new-cont-var))))) - ) - (build-call-lambda/try3 - rator - new-cont-var - (generate new-env (cdr lambda-list) rands) - (cleanup/expr env cont))) + ;; and poping have to be kept in the right order. Deal with + ;; this by splitting off the continuation binding and + ;; treating the rest of the bindings normally. + (let ((old-cont-var (car lambda-list))) + (let ((cont* (cleanup/expr env cont))) + (let ((cont-binding (cleanup/env/enter! env old-cont-var))) + (let ((result + (cleanup/bind-stack-closure + rator + (cleanup/binding/name cont-binding) + (generate env (cdr lambda-list) rands) + cont*))) + (cleanup/env/exit! env old-cont-var) + result)))) (generate env lambda-list (cons cont rands))))) ((not *flush-closure-calls?*) (default)) @@ -217,9 +202,7 @@ MIT in each case. |# (let ((call* (default))) (cond ((form/match cleanup/call-closure-pattern call*) => (lambda (result) - (cleanup/call/maybe-flush-closure call* - env - result))) + (cleanup/call/maybe-flush-closure call* env result))) ((form/match cleanup/call-trivial-pattern call*) => (lambda (result) (let ((lam-expr (cadr (assq cleanup/?lam-expr result))) @@ -227,19 +210,33 @@ MIT in each case. |# (cont (cadr (assq cleanup/?cont result)))) (cleanup/expr env `(CALL ,lam-expr ,cont ,@rands))))) - (else - call*)))))) - - -(define (build-call-lambda/try3 rator new-cont-var body closure) - ;; We can further reduce one special case: when the body is an - ;; invoke-continuation and the stack closure is a real - ;; continuation (not just a push) + (else call*)))))) + +(define (cleanup/bind-stack-closure rator new-cont-var body closure) + ;; Construct an expression of the form + ;; (CALL (LAMBDA (new-cont-var) body) closure) + ;; + ;; We handle two special cases, which are equivalent to substituting for + ;; NEW-CONT-VAR. This would not be necessary if simplify was + ;; better. As simplify is one-pass, it occasionally leaves redexes + ;; which only get discovered after stack closures are introduced. + ;; In fact, simplify might be a better place for this rewrite. The + ;; rewrites look clearer in standard CPS scheme (K is NEW-CONT-VAR): + ;; + ;; ((lambda (k) (k e1 ...)) ) => ( e1 ...) + ;; ((lambda (k) (f k e1 ...)) ) => (f e1 ...) + ;; + ;; Note that we take care to check that the make-stack-closure is a real + ;; continuation and not, for example, pushing extra arguments. + + (define (ordinary-case) + (let ((new-lambda `(LAMBDA (,new-cont-var) ,body))) + (cleanup/remember new-lambda rator) + `(CALL ,new-lambda ,closure))) (cond ((and (CALL/%invoke-continuation? body) (LOOKUP/? (call/%invoke-continuation/cont body)) (eq? new-cont-var - (lookup/name - (call/%invoke-continuation/cont body))) + (lookup/name (call/%invoke-continuation/cont body))) (CALL/%make-stack-closure? closure) (LAMBDA/? (CALL/%make-stack-closure/lambda-expression closure))) @@ -256,11 +253,7 @@ MIT in each case. |# `(CALL ,(call/operator body) ,closure ,@(call/operands body))) - (else - (let ((new-lambda `(LAMBDA (,new-cont-var) ,body))) - (cleanup/remember new-lambda rator) - `(CALL ,new-lambda ,closure))))) - + (else (ordinary-case)))) (define *cleanup/rewriters* (make-monotonic-strong-eq-hash-table)) @@ -278,7 +271,6 @@ MIT in each case. |# name (cons (cons arity handler) slot))) name) - (let () ;; Arithmetic constant folding @@ -340,16 +332,14 @@ MIT in each case. |# ) ;; Fixnum algebraic rewrites -;; -;; (+ (+ x a) b) => (+ x (+ a b)) -;; (+ a x) => (+ x a) -;; (- x a) => (+ x -a) -;; (+ (+ x a) (+ y b)) => (+ (+ x y) (+ a b)) +;; (+ (+ x a) b) => (+ x (+ a b)) +;; (+ a x) => (+ x a) +;; (- x a) => (+ x -a) +;; (+ (+ x a) (+ y b)) => (+ (+ x y) (+ a b)) (let () (define (constant-case op value1 value2) ; OP should be overflow-save - (and (fixnum? value1) - (fixnum? value2) + (and (fixnum? value1) (fixnum? value2) (let ((result (op value1 value2))) (and (fixnum? result) `(QUOTE ,result))))) @@ -407,40 +397,40 @@ MIT in each case. |# (define-cleanup-rewrite 'STRING->SYMBOL 1 (lambda (expr) - (let ((value (form/number? expr))) - (and (QUOTE/? expr) - (string? (quote/text expr)) - `(QUOTE ,(string->symbol (quote/text expr))))))) + (and (QUOTE/? expr) + (string? (quote/text expr)) + `(QUOTE ,(string->symbol (quote/text expr)))))) (define-cleanup-rewrite (make-primitive-procedure 'EQ?) 2 (lambda (e1 e2) (and (QUOTE/? e1) (QUOTE/? e2) `(QUOTE ,(eq? (quote/text e1) (quote/text e2)))))) - -;; + (let ((NOT-primitive (make-primitive-procedure 'NOT))) (define (form-absorbs-not? form) - ;; Assumption: non out-of-line predicates can be compiled with negated - ;; tests. - (or (and (CALL/? form) + ;; Assumption: open-coded (non out-of-line) predicates can be compiled + ;; with negated tests. + (or (QUOTE/? form) + (LOOKUP/? form) ; only true if in a predicate context + (and (CALL/? form) (QUOTE/? (call/operator form)) (let ((rator (quote/text (call/operator form)))) (and (operator/satisfies? rator '(PROPER-PREDICATE)) - (not (operator/satisfies? rator '(OUT-OF-LINE-HOOK)))))) - (QUOTE/? form) - (LOOKUP/? form))) - (define-cleanup-rewrite NOT-primitive 1 - (lambda (expr) - ;; (NOT (IF p c a)) => (IF p (NOT c) (NOT a)) - (if (and (IF/? expr) - (or (form-absorbs-not? (if/consequent expr)) - (form-absorbs-not? (if/alternate expr)))) - `(IF ,(if/predicate expr) - (CALL (QUOTE ,NOT-primitive) '#F ,(if/consequent expr)) - (CALL (QUOTE ,NOT-primitive) '#F ,(if/alternate expr))) - `(CALL (QUOTE ,NOT-primitive) '#F ,expr))))) - + (not (operator/satisfies? rator '(OUT-OF-LINE-HOOK)))))))) + (define (apply-NOT expr) + (cond ((QUOTE/? expr) `(QUOTE ,(not (quote/text expr)))) + ((and (IF/? expr) + (or (form-absorbs-not? (if/consequent expr)) + (form-absorbs-not? (if/alternate expr)))) + ;; (NOT (IF p c a)) => (IF p (NOT c) (NOT a)) + `(IF ,(if/predicate expr) + ,(apply-NOT (if/consequent expr)) + ,(apply-NOT (if/alternate expr)))) + (else + `(CALL (QUOTE ,NOT-primitive) '#F ,expr)))) + (define-cleanup-rewrite NOT-primitive 1 apply-NOT)) + (define (cleanup/call/maybe-flush-closure call* env match-result) (let ((lambda-expr (cadr (assq cleanup/?lam-expr match-result))) (cont (cadr (assq cleanup/?cont match-result))) @@ -474,7 +464,7 @@ MIT in each case. |# `(QUOTE #F) `(LOOKUP ,cont-name)) ,@rands))))))))))) - + (define cleanup/?closure-elts (->pattern-variable 'CLOSURE-ELTS)) (define cleanup/?closure-vector (->pattern-variable 'CLOSURE-VECTOR)) (define cleanup/?cont (->pattern-variable 'CONT)) @@ -502,7 +492,7 @@ MIT in each case. |# (QUOTE #F) ,cleanup/?lam-expr) ,@cleanup/?rands)) - + (define (cleanup/closure-refs form var-name) ;; (values self-refs ordinary-refs) ;; var-name is assumed to be unique, so there is @@ -539,166 +529,68 @@ MIT in each case. |# (define (cleanup/let* letify env bindings body) ;; Some bindings bind names to trivial expressions (e.g. constant) and ;; easy expression (e.g. closure references). We substitute the - ;; expressions for these names in BODY, but first we look at the - ;; names in these expressions and rename to avoid name capture. - (let ((bindings* (map (lambda (binding) - (cleanup/binding/make - (car binding) - (cleanup/expr env (cadr binding)))) - bindings))) - (define (dbg-track! bindings) - (for-each (lambda (binding) - (dbg-info/remember (cleanup/binding/name binding) - (form/copy (cleanup/binding/value binding)))) - bindings)) - (call-with-values - (lambda () - (list-split bindings* - (lambda (binding*) - (QUOTE/? (cleanup/binding/value binding*))))) - (lambda (trivial non-trivial) - (call-with-values - (lambda () - (list-split non-trivial - (lambda (binding*) - (cleanup/easy? (cleanup/binding/value binding*))))) - (lambda (easy non-easy) - (let* ((possibly-captured - (map (lambda (binding) - (cleanup/easy/name (cleanup/binding/value binding))) - easy)) - (complex-triplets - ;; (original-name renamed-version value-expression) - (map (lambda (binding) - (let ((name (cleanup/binding/name binding))) - (list name - (if (memq name possibly-captured) - (variable/rename name) - name) - (cleanup/binding/value binding)))) - non-easy)) - (env* - (cleanup/env/extend - env - (map* (append trivial easy) - (lambda (triplet) - (cleanup/binding/make - (car triplet) - `(LOOKUP ,(cadr triplet)))) - complex-triplets)))) - (dbg-track! trivial) - (dbg-track! easy) - (let ((body* (cleanup/expr env* body))) - (if (null? complex-triplets) - body* - (letify (map cdr complex-triplets) - body*)))))))))) - -(define (cleanup/easy? form) - (cond ((LOOKUP/? form) true) - ((CALL/? form) - (let ((rator (call/operator form))) - (and (QUOTE/? rator) - (memq (quote/text rator) cleanup/easy/ops) - (let ((cont&rands (call/cont-and-operands form))) - (and (for-all? cont&rands cleanup/trivial?) - (let ((all-lookups - (list-transform-positive cont&rands LOOKUP/?))) - (or (null? all-lookups) - (null? (cdr all-lookups))))))))) - (else - false))) - -(define (cleanup/trivial? form) - (or (QUOTE/? form) - (LOOKUP/? form) - (and (CALL/? form) - (QUOTE (call/operator form)) - (memq (quote/text (call/operator form)) cleanup/trivial/ops) - (for-all? (call/cont-and-operands form) - QUOTE/?)))) - -(define (cleanup/easy/name form) - ;; form must satisfy cleanup/easy? - (cond ((LOOKUP/? form) (lookup/name form)) - ((CALL/? form) - (let ((lookup-rand - (list-search-positive (call/cont-and-operands form) LOOKUP/?))) - (and lookup-rand - (lookup/name lookup-rand)))) - (else - (internal-error "Unrecognized easy form" form)))) - -(define cleanup/trivial/ops '()) -; (list %vector-index) + ;; expressions for these names in BODY. The rest remain bound. + (define (binding-value binding) (cleanup/expr env (second binding))) + (define (exit! binding) (cleanup/env/exit! env (car binding))) + (define (loop bindings* values* remainding-bindings) + (cond ((null? bindings*) (reverse! remainding-bindings)) + ((cleanup/always-substitute? (car values*)) + (cleanup/env/enter!/value env (caar bindings*) (car values*)) + (loop (cdr bindings*) (cdr values*) remainding-bindings)) + (else + (let ((new-binding (cleanup/env/enter! env (caar bindings*)))) + (loop (cdr bindings*) + (cdr values*) + (cons (list (cleanup/binding/name new-binding) + (car values*)) + remainding-bindings)))))) + (let ((values (map binding-value bindings))) + (let ((remainding-bindings (loop bindings values '()))) + (let ((body* (cleanup/expr env body))) + (for-each exit! bindings) + (if (null? remainding-bindings) + body* + (letify remainding-bindings body*)))))) + +(define (cleanup/always-substitute? form) + (or (LOOKUP/? form) + (QUOTE/? form) + (call/%stack-closure-ref? form) + (call/%heap-closure-ref? form))) ; OK: no mutators for heap closures -(define cleanup/easy/ops - (append cleanup/trivial/ops - (list %stack-closure-ref %heap-closure-ref))) - (define (cleanup/letify bindings body) `(LET ,bindings ,body)) -(define (cleanup/bindify lambda-list operands) +(define (cleanup/lambda-list->bindings lambda-list operands) + ;; returns LET-like bindings (map (lambda (name operand) (list name operand)) (lambda-list->names lambda-list) (lambda-list/applicate lambda-list operands))) (define (cleanup/pseudo-letify rator bindings body) + ;; If the body is a lookup (define (default) (pseudo-letify rator bindings body cleanup/remember)) (define (trivial last bindings) (beginnify (map* (list last) cadr bindings))) (cond ((memq *order-of-argument-evaluation* '(ANY LEFT-TO-RIGHT)) (default)) - ((LOOKUP/? body) - (let* ((name (lookup/name body)) - (place (assq name bindings))) + ((LOOKUP/? body) ; ([]LET (... (x e) ...) x) => (begin ... e) + (let ((place (assq (lookup/name body) bindings))) (if (not place) (trivial body bindings) - (trivial - (cadr place) - (delq place bindings))))) + (trivial (second place) (delq place bindings))))) ((QUOTE/? body) (trivial body bindings)) (else (default)))) - -(define (cleanup/rename renames token) - (let loop ((bindings renames)) - (cond ((not (pair? bindings)) - token) - ((eq? token (cleanup/binding/name (car bindings))) - (lookup/name (cleanup/binding/value (car bindings)))) - (else - (loop (cdr bindings)))))) - -(define (cleanup/renamings env names) - (map (lambda (name) - (let ((value (cleanup/env/lookup name env))) - ;; Do not rename if the shadowed binding is disappearing - (cond ((or (not value) - (QUOTE/? value)) - (cleanup/binding/make name `(LOOKUP ,name))) - (else - (let ((renamed-form - `(LOOKUP ,(variable/rename name)))) - (dbg-info/remember name renamed-form) - (cleanup/binding/make name renamed-form)))))) - names)) - -;; Environment is a list of frames. Frames are a list of bindings. + +;; Environment is a map from names to bindings. Because the flow of +;; control is a DFS of the scopes, we can maintain the map by adding +;; bindings on entry to a scope, and removing it on exit. (define (cleanup/env/find name env) - (let frame-loop ((env env)) - (and (pair? env) - (let loop ((bindings (car env))) - (cond ((not (pair? bindings)) - (frame-loop (cdr env))) - ((eq? name (cleanup/binding/name (car bindings))) - (car bindings)) - (else - (loop (cdr bindings)))))))) + (monotonic-strong-eq-hash-table/get env name #F)) (define (cleanup/env/lookup name env) (let ((binding (cleanup/env/find name env))) @@ -706,18 +598,39 @@ MIT in each case. |# (cleanup/binding/value binding)))) (define (cleanup/env/initial) - '()) - -(define (cleanup/env/extend env new-frame) - (cons new-frame env)) - -;;(define-integrable (cleanup/binding/make name value) (cons name value)) -;;(define-integrable (cleanup/binding/name binding) (car binding)) -;;(define-integrable (cleanup/binding/value binding) (cdr binding)) - -(define-integrable (cleanup/binding/make name value) (vector name value)) -(define-integrable (cleanup/binding/name binding) (vector-ref binding 0)) -(define-integrable (cleanup/binding/value binding) (vector-ref binding 1)) + (make-monotonic-strong-eq-hash-table)) + +(define (cleanup/env/enter! env name) ; ->binding + (let* ((shadowed (monotonic-strong-eq-hash-table/get env name #F)) + (name* (if shadowed + (let ((new-name (variable/rename name))) + (dbg-info/remember name new-name) + new-name) + name)) + (binding (cleanup/binding/make name* `(LOOKUP ,name*) shadowed))) + (monotonic-strong-eq-hash-table/put! env name binding) + binding)) + +(define (cleanup/env/enter!/value env name value) ; ->binding + ;; enter the scope of a variable which will be substituted + (let* ((shadowed (monotonic-strong-eq-hash-table/get env name #F)) + (binding (cleanup/binding/make #F value shadowed))) + (dbg-info/remember name value) + (monotonic-strong-eq-hash-table/put! env name binding) + binding)) + +(define (cleanup/env/exit! env name) + (let ((binding (monotonic-strong-eq-hash-table/get env name #F))) + (monotonic-strong-eq-hash-table/put! env name + (cleanup/binding/shadowed binding)))) + +(define-structure + (cleanup/binding + (conc-name cleanup/binding/) + (constructor cleanup/binding/make (name value shadowed))) + (name #F read-only true) + (value #F read-only true) + (shadowed #F read-only true)) (define (cleanup/expr env expr) (if (not (pair? expr)) -- 2.25.1