--- /dev/null
+;;; Guile VM code converters
+
+;; Copyright (C) 2001, 2009, 2012, 2013 Free Software Foundation, Inc.
+
+;;;; This library is free software; you can redistribute it and/or
+;;;; modify it under the terms of the GNU Lesser General Public
+;;;; License as published by the Free Software Foundation; either
+;;;; version 3 of the License, or (at your option) any later version.
+;;;;
+;;;; This library 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
+;;;; Lesser General Public License for more details.
+;;;;
+;;;; You should have received a copy of the GNU Lesser General Public
+;;;; License along with this library; if not, write to the Free Software
+;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
+
+;;; Code:
+
+(define-module (language scheme decompile-tree-il)
+ #:use-module (language tree-il)
+ #:use-module (srfi srfi-1)
+ #:use-module (srfi srfi-26)
+ #:use-module (ice-9 receive)
+ #:use-module (ice-9 vlist)
+ #:use-module (ice-9 match)
+ #:use-module (system base syntax)
+ #:export (decompile-tree-il))
+
+(define (decompile-tree-il e env opts)
+ (apply do-decompile e env opts))
+
+(define* (do-decompile e env
+ #:key
+ (use-derived-syntax? #t)
+ (avoid-lambda? #t)
+ (use-case? #t)
+ (strip-numeric-suffixes? #f)
+ #:allow-other-keys)
+
+ (receive (output-name-table occurrence-count-table)
+ (choose-output-names e use-derived-syntax? strip-numeric-suffixes?)
+
+ (define (output-name s) (hashq-ref output-name-table s))
+ (define (occurrence-count s) (hashq-ref occurrence-count-table s))
+
+ (define (const x) (lambda (_) x))
+ (define (atom? x) (not (or (pair? x) (vector? x))))
+
+ (define (build-void) '(if #f #f))
+
+ (define (build-begin es)
+ (match es
+ (() (build-void))
+ ((e) e)
+ (_ `(begin ,@es))))
+
+ (define (build-lambda-body e)
+ (match e
+ (('let () body ...) body)
+ (('begin es ...) es)
+ (_ (list e))))
+
+ (define (build-begin-body e)
+ (match e
+ (('begin es ...) es)
+ (_ (list e))))
+
+ (define (build-define name e)
+ (match e
+ ((? (const avoid-lambda?)
+ ('lambda formals body ...))
+ `(define (,name ,@formals) ,@body))
+ ((? (const avoid-lambda?)
+ ('lambda* formals body ...))
+ `(define* (,name ,@formals) ,@body))
+ (_ `(define ,name ,e))))
+
+ (define (build-let names vals body)
+ (match `(let ,(map list names vals)
+ ,@(build-lambda-body body))
+ ((_ () e) e)
+ ((_ (b) ('let* (bs ...) body ...))
+ `(let* (,b ,@bs) ,@body))
+ ((? (const use-derived-syntax?)
+ (_ (b1) ('let (b2) body ...)))
+ `(let* (,b1 ,b2) ,@body))
+ (e e)))
+
+ (define (build-letrec in-order? names vals body)
+ (match `(,(if in-order? 'letrec* 'letrec)
+ ,(map list names vals)
+ ,@(build-lambda-body body))
+ ((_ () e) e)
+ ((_ () body ...) `(let () ,@body))
+ ((_ ((name ('lambda (formals ...) body ...)))
+ (name args ...))
+ (=> failure)
+ (if (= (length formals) (length args))
+ `(let ,name ,(map list formals args) ,@body)
+ (failure)))
+ ((? (const avoid-lambda?)
+ ('letrec* _ body ...))
+ `(let ()
+ ,@(map build-define names vals)
+ ,@body))
+ (e e)))
+
+ (define (build-if test consequent alternate)
+ (match alternate
+ (('if #f _) `(if ,test ,consequent))
+ (_ `(if ,test ,consequent ,alternate))))
+
+ (define (build-and xs)
+ (match xs
+ (() #t)
+ ((x) x)
+ (_ `(and ,@xs))))
+
+ (define (build-or xs)
+ (match xs
+ (() #f)
+ ((x) x)
+ (_ `(or ,@xs))))
+
+ (define (case-test-var test)
+ (match test
+ (('memv (? atom? v) ('quote (datums ...)))
+ v)
+ (('eqv? (? atom? v) ('quote datum))
+ v)
+ (_ #f)))
+
+ (define (test->datums v test)
+ (match (cons v test)
+ ((v 'memv v ('quote (xs ...)))
+ xs)
+ ((v 'eqv? v ('quote x))
+ (list x))
+ (_ #f)))
+
+ (define (build-else-tail e)
+ (match e
+ (('if #f _) '())
+ (('and xs ... x) `((,(build-and xs) ,@(build-begin-body x))
+ (else #f)))
+ (_ `((else ,@(build-begin-body e))))))
+
+ (define (build-cond-else-tail e)
+ (match e
+ (('cond clauses ...) clauses)
+ (_ (build-else-tail e))))
+
+ (define (build-case-else-tail v e)
+ (match (cons v e)
+ ((v 'case v clauses ...)
+ clauses)
+ ((v 'if ('memv v ('quote (xs ...))) consequent . alternate*)
+ `((,xs ,@(build-begin-body consequent))
+ ,@(build-case-else-tail v (build-begin alternate*))))
+ ((v 'if ('eqv? v ('quote x)) consequent . alternate*)
+ `(((,x) ,@(build-begin-body consequent))
+ ,@(build-case-else-tail v (build-begin alternate*))))
+ (_ (build-else-tail e))))
+
+ (define (clauses+tail clauses)
+ (match clauses
+ ((cs ... (and c ('else . _))) (values cs (list c)))
+ (_ (values clauses '()))))
+
+ (define (build-cond tests consequents alternate)
+ (case (length tests)
+ ((0) alternate)
+ ((1) (build-if (car tests) (car consequents) alternate))
+ (else `(cond ,@(map (lambda (test consequent)
+ `(,test ,@(build-begin-body consequent)))
+ tests consequents)
+ ,@(build-cond-else-tail alternate)))))
+
+ (define (build-cond-or-case tests consequents alternate)
+ (if (not use-case?)
+ (build-cond tests consequents alternate)
+ (let* ((v (and (not (null? tests))
+ (case-test-var (car tests))))
+ (datum-lists (take-while identity
+ (map (cut test->datums v <>)
+ tests)))
+ (n (length datum-lists))
+ (tail (build-case-else-tail v (build-cond
+ (drop tests n)
+ (drop consequents n)
+ alternate))))
+ (receive (clauses tail) (clauses+tail tail)
+ (let ((n (+ n (length clauses)))
+ (datum-lists (append datum-lists
+ (map car clauses)))
+ (consequents (append consequents
+ (map build-begin
+ (map cdr clauses)))))
+ (if (< n 2)
+ (build-cond tests consequents alternate)
+ `(case ,v
+ ,@(map cons datum-lists (map build-begin-body
+ (take consequents n)))
+ ,@tail)))))))
+
+ (define (recurse e)
+
+ (define (recurse-body e)
+ (build-lambda-body (recurse e)))
+
+ (record-case e
+ ((<void>)
+ (build-void))
+
+ ((<const> exp)
+ (if (and (self-evaluating? exp) (not (vector? exp)))
+ exp
+ `(quote ,exp)))
+
+ ((<seq> head tail)
+ (build-begin (cons (recurse head)
+ (build-begin-body
+ (recurse tail)))))
+
+ ((<call> proc args)
+ (match `(,(recurse proc) ,@(map recurse args))
+ ((('lambda (formals ...) body ...) args ...)
+ (=> failure)
+ (if (= (length formals) (length args))
+ (build-let formals args (build-begin body))
+ (failure)))
+ (e e)))
+
+ ((<primcall> name args)
+ `(,name ,@(map recurse args)))
+
+ ((<primitive-ref> name)
+ name)
+
+ ((<lexical-ref> gensym)
+ (output-name gensym))
+
+ ((<lexical-set> gensym exp)
+ `(set! ,(output-name gensym) ,(recurse exp)))
+
+ ((<module-ref> mod name public?)
+ `(,(if public? '@ '@@) ,mod ,name))
+
+ ((<module-set> mod name public? exp)
+ `(set! (,(if public? '@ '@@) ,mod ,name) ,(recurse exp)))
+
+ ((<toplevel-ref> name)
+ name)
+
+ ((<toplevel-set> name exp)
+ `(set! ,name ,(recurse exp)))
+
+ ((<toplevel-define> name exp)
+ (build-define name (recurse exp)))
+
+ ((<lambda> meta body)
+ (if body
+ (let ((body (recurse body))
+ (doc (assq-ref meta 'documentation)))
+ (if (not doc)
+ body
+ (match body
+ (('lambda formals body ...)
+ `(lambda ,formals ,doc ,@body))
+ (('lambda* formals body ...)
+ `(lambda* ,formals ,doc ,@body))
+ (('case-lambda (formals body ...) clauses ...)
+ `(case-lambda (,formals ,doc ,@body) ,@clauses))
+ (('case-lambda* (formals body ...) clauses ...)
+ `(case-lambda* (,formals ,doc ,@body) ,@clauses))
+ (e e))))
+ '(case-lambda)))
+
+ ((<lambda-case> req opt rest kw inits gensyms body alternate)
+ (let ((names (map output-name gensyms)))
+ (cond
+ ((and (not opt) (not kw) (not alternate))
+ `(lambda ,(if rest (apply cons* names) names)
+ ,@(recurse-body body)))
+ ((and (not opt) (not kw))
+ (let ((alt-expansion (recurse alternate))
+ (formals (if rest (apply cons* names) names)))
+ (case (car alt-expansion)
+ ((lambda)
+ `(case-lambda (,formals ,@(recurse-body body))
+ ,(cdr alt-expansion)))
+ ((lambda*)
+ `(case-lambda* (,formals ,@(recurse-body body))
+ ,(cdr alt-expansion)))
+ ((case-lambda)
+ `(case-lambda (,formals ,@(recurse-body body))
+ ,@(cdr alt-expansion)))
+ ((case-lambda*)
+ `(case-lambda* (,formals ,@(recurse-body body))
+ ,@(cdr alt-expansion))))))
+ (else
+ (let* ((alt-expansion (and alternate (recurse alternate)))
+ (nreq (length req))
+ (nopt (if opt (length opt) 0))
+ (restargs (if rest (list-ref names (+ nreq nopt)) '()))
+ (reqargs (list-head names nreq))
+ (optargs (if opt
+ `(#:optional
+ ,@(map list
+ (list-head (list-tail names nreq) nopt)
+ (map recurse
+ (list-head inits nopt))))
+ '()))
+ (kwargs (if kw
+ `(#:key
+ ,@(map list
+ (map output-name (map caddr (cdr kw)))
+ (map recurse
+ (list-tail inits nopt))
+ (map car (cdr kw)))
+ ,@(if (car kw)
+ '(#:allow-other-keys)
+ '()))
+ '()))
+ (formals `(,@reqargs ,@optargs ,@kwargs . ,restargs)))
+ (if (not alt-expansion)
+ `(lambda* ,formals ,@(recurse-body body))
+ (case (car alt-expansion)
+ ((lambda lambda*)
+ `(case-lambda* (,formals ,@(recurse-body body))
+ ,(cdr alt-expansion)))
+ ((case-lambda case-lambda*)
+ `(case-lambda* (,formals ,@(recurse-body body))
+ ,@(cdr alt-expansion))))))))))
+
+ ((<conditional> test consequent alternate)
+ (define (simplify-test e)
+ (match e
+ (('if ('eqv? (? atom? v) ('quote a)) #t ('eqv? v ('quote b)))
+ `(memv ,v '(,a ,b)))
+ (('if ('eqv? (? atom? v) ('quote a)) #t ('memv v ('quote (bs ...))))
+ `(memv ,v '(,a ,@bs)))
+ (('case (? atom? v)
+ ((datum) #t) ...
+ ('else ('eqv? v ('quote last-datum))))
+ `(memv ,v '(,@datum ,last-datum)))
+ (_ e)))
+ (match `(if ,(simplify-test (recurse test))
+ ,(recurse consequent)
+ ,@(if (void? alternate) '()
+ (list (recurse alternate))))
+ (('if test ('if ('and xs ...) consequent))
+ (build-if (build-and (cons test xs))
+ consequent
+ (build-void)))
+ ((? (const use-derived-syntax?)
+ ('if test1 ('if test2 consequent)))
+ (build-if (build-and (list test1 test2))
+ consequent
+ (build-void)))
+ (('if (? atom? x) x ('or ys ...))
+ (build-or (cons x ys)))
+ ((? (const use-derived-syntax?)
+ ('if (? atom? x) x y))
+ (build-or (list x y)))
+ (('if test consequent)
+ `(if ,test ,consequent))
+ (('if test ('and xs ...) #f)
+ (build-and (cons test xs)))
+ ((? (const use-derived-syntax?)
+ ('if test consequent #f))
+ (build-and (list test consequent)))
+ ((? (const use-derived-syntax?)
+ ('if test1 consequent1
+ ('if test2 consequent2 . alternate*)))
+ (build-cond-or-case (list test1 test2)
+ (list consequent1 consequent2)
+ (build-begin alternate*)))
+ (('if test consequent ('cond clauses ...))
+ `(cond (,test ,@(build-begin-body consequent))
+ ,@clauses))
+ (('if ('memv (? atom? v) ('quote (xs ...))) consequent
+ ('case v clauses ...))
+ `(case ,v (,xs ,@(build-begin-body consequent))
+ ,@clauses))
+ (('if ('eqv? (? atom? v) ('quote x)) consequent
+ ('case v clauses ...))
+ `(case ,v ((,x) ,@(build-begin-body consequent))
+ ,@clauses))
+ (e e)))
+
+ ((<let> gensyms vals body)
+ (match (build-let (map output-name gensyms)
+ (map recurse vals)
+ (recurse body))
+ (('let ((v e)) ('or v xs ...))
+ (=> failure)
+ (if (and (not (null? gensyms))
+ (= 3 (occurrence-count (car gensyms))))
+ `(or ,e ,@xs)
+ (failure)))
+ (('let ((v e)) ('case v clauses ...))
+ (=> failure)
+ (if (and (not (null? gensyms))
+ ;; FIXME: This fails if any of the 'memv's were
+ ;; optimized into multiple 'eqv?'s, because the
+ ;; occurrence count will be higher than we expect.
+ (= (occurrence-count (car gensyms))
+ (1+ (length (clauses+tail clauses)))))
+ `(case ,e ,@clauses)
+ (failure)))
+ (e e)))
+
+ ((<letrec> in-order? gensyms vals body)
+ (build-letrec in-order?
+ (map output-name gensyms)
+ (map recurse vals)
+ (recurse body)))
+
+ ((<fix> gensyms vals body)
+ ;; not a typo, we really do translate back to letrec. use letrec* since it
+ ;; doesn't matter, and the naive letrec* transformation does not require an
+ ;; inner let.
+ (build-letrec #t
+ (map output-name gensyms)
+ (map recurse vals)
+ (recurse body)))
+
+ ((<let-values> exp body)
+ `(call-with-values (lambda () ,@(recurse-body exp))
+ ,(recurse (make-lambda #f '() body))))
+
+ ((<prompt> escape-only? tag body handler)
+ `(call-with-prompt
+ ,(recurse tag)
+ ,(if escape-only?
+ `(lambda () ,(recurse body))
+ (recurse body))
+ ,(recurse handler)))
+
+
+ ((<abort> tag args tail)
+ `(apply abort ,(recurse tag) ,@(map recurse args)
+ ,(recurse tail)))))
+ (values (recurse e) env)))
+
+;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
+;;
+;; Algorithm for choosing better variable names
+;; ============================================
+;;
+;; First we perform an analysis pass, collecting the following
+;; information:
+;;
+;; * For each gensym: how many occurrences will occur in the output?
+;;
+;; * For each gensym A: which gensyms does A conflict with? Gensym A
+;; and gensym B conflict if they have the same base name (usually the
+;; same as the source name, but see below), and if giving them the
+;; same name would cause a bad variable reference due to unintentional
+;; variable capture.
+;;
+;; The occurrence counter is indexed by gensym and is global (within each
+;; invocation of the algorithm), implemented using a hash table. We also
+;; keep a global mapping from gensym to source name as provided by the
+;; binding construct (we prefer not to trust the source names in the
+;; lexical ref or set).
+;;
+;; As we recurse down into lexical binding forms, we keep track of a
+;; mapping from base name to an ordered list of bindings, innermost
+;; first. When we encounter a variable occurrence, we increment the
+;; counter, look up the base name (preferring not to trust the 'name' in
+;; the lexical ref or set), and then look up the bindings currently in
+;; effect for that base name. Hopefully our gensym will be the first
+;; (innermost) binding. If not, we register a conflict between the
+;; referenced gensym and the other bound gensyms with the same base name
+;; that shadow the binding we want. These are simply the gensyms on the
+;; binding list that come before our gensym.
+;;
+;; Top-level bindings are treated specially. Whenever top-level
+;; references are found, they conflict with every lexical binding
+;; currently in effect with the same base name. They are guaranteed to
+;; be assigned to their source names. For purposes of recording
+;; conflicts (which are normally keyed on gensyms) top-level identifiers
+;; are assigned a pseudo-gensym that is an interned pair of the form
+;; (top-level . <name>). This allows them to be compared using 'eq?'
+;; like other gensyms.
+;;
+;; The base name is normally just the source name. However, if the
+;; source name has a suffix of the form "-N" (where N is a positive
+;; integer without leading zeroes), then we strip that suffix (multiple
+;; times if necessary) to form the base name. We must do this because
+;; we add suffixes of that form in order to resolve conflicts, and we
+;; must ensure that only identifiers with the same base name can
+;; possibly conflict with each other.
+;;
+;; XXX FIXME: Currently, primitives are treated exactly like top-level
+;; bindings. This handles conflicting lexical bindings properly, but
+;; does _not_ handle the case where top-level bindings conflict with the
+;; needed primitives.
+;;
+;; Also note that this requires that 'choose-output-names' be kept in
+;; sync with 'tree-il->scheme'. Primitives that are introduced by
+;; 'tree-il->scheme' must be anticipated by 'choose-output-name'.
+;;
+;; We also ensure that lexically-bound identifiers found in operator
+;; position will never be assigned one of the standard primitive names.
+;; This is needed because 'tree-il->scheme' recognizes primitive names
+;; in operator position and assumes that they have the standard
+;; bindings.
+;;
+;;
+;; How we assign an output name to each gensym
+;; ===========================================
+;;
+;; We process the gensyms in order of decreasing occurrence count, with
+;; each gensym choosing the best output name possible, as long as it
+;; isn't the same name as any of the previously-chosen output names of
+;; conflicting gensyms.
+;;
+
+
+;;
+;; 'choose-output-names' analyzes the top-level form e, chooses good
+;; variable names that are as close as possible to the source names,
+;; and returns two values:
+;;
+;; * a hash table mapping gensym to output name
+;; * a hash table mapping gensym to number of occurrences
+;;
+(define choose-output-names
+ (let ()
+ (define primitive?
+ ;; This is a list of primitives that 'tree-il->scheme' assumes
+ ;; will have the standard bindings when found in operator
+ ;; position.
+ (let* ((primitives '(if quote @ @@ set! define define*
+ begin let let* letrec letrec*
+ and or cond case
+ lambda lambda* case-lambda case-lambda*
+ apply call-with-values dynamic-wind
+ with-fluids fluid-ref fluid-set!
+ call-with-prompt abort memv eqv?))
+ (table (make-hash-table (length primitives))))
+ (for-each (cut hashq-set! table <> #t) primitives)
+ (lambda (name) (hashq-ref table name))))
+
+ ;; Repeatedly strip suffix of the form "-N", where N is a string
+ ;; that could be produced by number->string given a positive
+ ;; integer. In other words, the first digit of N may not be 0.
+ (define compute-base-name
+ (let ((digits (string->char-set "0123456789")))
+ (define (base-name-string str)
+ (let ((i (string-skip-right str digits)))
+ (if (and i (< (1+ i) (string-length str))
+ (eq? #\- (string-ref str i))
+ (not (eq? #\0 (string-ref str (1+ i)))))
+ (base-name-string (substring str 0 i))
+ str)))
+ (lambda (sym)
+ (string->symbol (base-name-string (symbol->string sym))))))
+
+ ;; choose-output-names
+ (lambda (e use-derived-syntax? strip-numeric-suffixes?)
+
+ (define lexical-gensyms '())
+
+ (define top-level-intern!
+ (let ((table (make-hash-table)))
+ (lambda (name)
+ (let ((h (hashq-create-handle! table name #f)))
+ (or (cdr h) (begin (set-cdr! h (cons 'top-level name))
+ (cdr h)))))))
+ (define (top-level? s) (pair? s))
+ (define (top-level-name s) (cdr s))
+
+ (define occurrence-count-table (make-hash-table))
+ (define (occurrence-count s) (or (hashq-ref occurrence-count-table s) 0))
+ (define (increment-occurrence-count! s)
+ (let ((h (hashq-create-handle! occurrence-count-table s 0)))
+ (if (zero? (cdr h))
+ (set! lexical-gensyms (cons s lexical-gensyms)))
+ (set-cdr! h (1+ (cdr h)))))
+
+ (define base-name
+ (let ((table (make-hash-table)))
+ (lambda (name)
+ (let ((h (hashq-create-handle! table name #f)))
+ (or (cdr h) (begin (set-cdr! h (compute-base-name name))
+ (cdr h)))))))
+
+ (define source-name-table (make-hash-table))
+ (define (set-source-name! s name)
+ (if (not (top-level? s))
+ (let ((name (if strip-numeric-suffixes?
+ (base-name name)
+ name)))
+ (hashq-set! source-name-table s name))))
+ (define (source-name s)
+ (if (top-level? s)
+ (top-level-name s)
+ (hashq-ref source-name-table s)))
+
+ (define conflict-table (make-hash-table))
+ (define (conflicts s) (or (hashq-ref conflict-table s) '()))
+ (define (add-conflict! a b)
+ (define (add! a b)
+ (if (not (top-level? a))
+ (let ((h (hashq-create-handle! conflict-table a '())))
+ (if (not (memq b (cdr h)))
+ (set-cdr! h (cons b (cdr h)))))))
+ (add! a b)
+ (add! b a))
+
+ (let recurse-with-bindings ((e e) (bindings vlist-null))
+ (let recurse ((e e))
+
+ ;; We call this whenever we encounter a top-level ref or set
+ (define (top-level name)
+ (let ((bname (base-name name)))
+ (let ((s (top-level-intern! name))
+ (conflicts (vhash-foldq* cons '() bname bindings)))
+ (for-each (cut add-conflict! s <>) conflicts))))
+
+ ;; We call this whenever we encounter a primitive reference.
+ ;; We must also call it for every primitive that might be
+ ;; inserted by 'tree-il->scheme'. It is okay to call this
+ ;; even when 'tree-il->scheme' will not insert the named
+ ;; primitive; the worst that will happen is for a lexical
+ ;; variable of the same name to be renamed unnecessarily.
+ (define (primitive name) (top-level name))
+
+ ;; We call this whenever we encounter a lexical ref or set.
+ (define (lexical s)
+ (increment-occurrence-count! s)
+ (let ((conflicts
+ (take-while
+ (lambda (s*) (not (eq? s s*)))
+ (reverse! (vhash-foldq* cons
+ '()
+ (base-name (source-name s))
+ bindings)))))
+ (for-each (cut add-conflict! s <>) conflicts)))
+
+ (record-case e
+ ((<void>) (primitive 'if)) ; (if #f #f)
+ ((<const>) (primitive 'quote))
+
+ ((<call> proc args)
+ (if (lexical-ref? proc)
+ (let* ((gensym (lexical-ref-gensym proc))
+ (name (source-name gensym)))
+ ;; If the operator position contains a bare variable
+ ;; reference with the same source name as a standard
+ ;; primitive, we must ensure that it will be given a
+ ;; different name, so that 'tree-il->scheme' will not
+ ;; misinterpret the resulting expression.
+ (if (primitive? name)
+ (add-conflict! gensym (top-level-intern! name)))))
+ (recurse proc)
+ (for-each recurse args))
+
+ ((<primitive-ref> name) (primitive name))
+ ((<primcall> name args) (primitive name) (for-each recurse args))
+
+ ((<lexical-ref> gensym) (lexical gensym))
+ ((<lexical-set> gensym exp)
+ (primitive 'set!) (lexical gensym) (recurse exp))
+
+ ((<module-ref> public?) (primitive (if public? '@ '@@)))
+ ((<module-set> public? exp)
+ (primitive 'set!) (primitive (if public? '@ '@@)) (recurse exp))
+
+ ((<toplevel-ref> name) (top-level name))
+ ((<toplevel-set> name exp)
+ (primitive 'set!) (top-level name) (recurse exp))
+ ((<toplevel-define> name exp) (top-level name) (recurse exp))
+
+ ((<conditional> test consequent alternate)
+ (cond (use-derived-syntax?
+ (primitive 'and) (primitive 'or)
+ (primitive 'cond) (primitive 'case)
+ (primitive 'else) (primitive '=>)))
+ (primitive 'if)
+ (recurse test) (recurse consequent) (recurse alternate))
+
+ ((<seq> head tail)
+ (primitive 'begin) (recurse head) (recurse tail))
+
+ ((<lambda> body)
+ (if body (recurse body) (primitive 'case-lambda)))
+
+ ((<lambda-case> req opt rest kw inits gensyms body alternate)
+ (primitive 'lambda)
+ (cond ((or opt kw alternate)
+ (primitive 'lambda*)
+ (primitive 'case-lambda)
+ (primitive 'case-lambda*)))
+ (primitive 'let)
+ (if use-derived-syntax? (primitive 'let*))
+ (let* ((names (append req (or opt '()) (if rest (list rest) '())
+ (map cadr (if kw (cdr kw) '()))))
+ (base-names (map base-name names))
+ (body-bindings
+ (fold vhash-consq bindings base-names gensyms)))
+ (for-each increment-occurrence-count! gensyms)
+ (for-each set-source-name! gensyms names)
+ (for-each recurse inits)
+ (recurse-with-bindings body body-bindings)
+ (if alternate (recurse alternate))))
+
+ ((<let> names gensyms vals body)
+ (primitive 'let)
+ (cond (use-derived-syntax? (primitive 'let*) (primitive 'or)))
+ (for-each increment-occurrence-count! gensyms)
+ (for-each set-source-name! gensyms names)
+ (for-each recurse vals)
+ (recurse-with-bindings
+ body (fold vhash-consq bindings (map base-name names) gensyms)))
+
+ ((<letrec> in-order? names gensyms vals body)
+ (primitive 'let)
+ (cond (use-derived-syntax? (primitive 'let*) (primitive 'or)))
+ (primitive (if in-order? 'letrec* 'letrec))
+ (for-each increment-occurrence-count! gensyms)
+ (for-each set-source-name! gensyms names)
+ (let* ((base-names (map base-name names))
+ (bindings (fold vhash-consq bindings base-names gensyms)))
+ (for-each (cut recurse-with-bindings <> bindings) vals)
+ (recurse-with-bindings body bindings)))
+
+ ((<fix> names gensyms vals body)
+ (primitive 'let)
+ (primitive 'letrec*)
+ (cond (use-derived-syntax? (primitive 'let*) (primitive 'or)))
+ (for-each increment-occurrence-count! gensyms)
+ (for-each set-source-name! gensyms names)
+ (let* ((base-names (map base-name names))
+ (bindings (fold vhash-consq bindings base-names gensyms)))
+ (for-each (cut recurse-with-bindings <> bindings) vals)
+ (recurse-with-bindings body bindings)))
+
+ ((<let-values> exp body)
+ (primitive 'call-with-values)
+ (recurse exp) (recurse body))
+
+ ((<prompt> tag body handler)
+ (primitive 'call-with-prompt)
+ (recurse tag) (recurse body) (recurse handler))
+
+ ((<abort> tag args tail)
+ (primitive 'apply)
+ (primitive 'abort)
+ (recurse tag) (for-each recurse args) (recurse tail)))))
+
+ (let ()
+ (define output-name-table (make-hash-table))
+ (define (set-output-name! s name)
+ (hashq-set! output-name-table s name))
+ (define (output-name s)
+ (if (top-level? s)
+ (top-level-name s)
+ (hashq-ref output-name-table s)))
+
+ (define sorted-lexical-gensyms
+ (sort-list lexical-gensyms
+ (lambda (a b) (> (occurrence-count a)
+ (occurrence-count b)))))
+
+ (for-each (lambda (s)
+ (set-output-name!
+ s
+ (let ((the-conflicts (conflicts s))
+ (the-source-name (source-name s)))
+ (define (not-yet-taken? name)
+ (not (any (lambda (s*)
+ (and=> (output-name s*)
+ (cut eq? name <>)))
+ the-conflicts)))
+ (if (not-yet-taken? the-source-name)
+ the-source-name
+ (let ((prefix (string-append
+ (symbol->string the-source-name)
+ "-")))
+ (let loop ((i 1) (name the-source-name))
+ (if (not-yet-taken? name)
+ name
+ (loop (+ i 1)
+ (string->symbol
+ (string-append
+ prefix
+ (number->string i)))))))))))
+ sorted-lexical-gensyms)
+ (values output-name-table occurrence-count-table)))))
projects / vouivre.git / commitdiff