ikarus/scheme/ikarus.fasl.ss

442 lines
15 KiB
Scheme

;;; Ikarus Scheme -- A compiler for R6RS Scheme.
;;; Copyright (C) 2006,2007,2008 Abdulaziz Ghuloum
;;;
;;; This program is free software: you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License version 3 as
;;; published by the Free Software Foundation.
;;;
;;; This program 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
;;; General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program. If not, see <http://www.gnu.org/licenses/>.
;;; FASL
;;;
;;; A fasl object is a header followed by one or more objects followed by an
;;; end-of-fasl marker
;;;
;;; The header is the string "#@IK01"
;;; The end of fasl marker is "@"
;;;
;;; An object is either:
;;; "N" : denoting the empty list
;;; "T" : denoting #t
;;; "F" : denoting #f
;;; "E" : denoting the end of file object
;;; "U" : denoting the unspecified value
;;; "I" + 4-bytes : denoting a fixnum (in host byte order)
;;; "c" + 1-byte : denoting a small character (<= 255)
;;; "C" + 4-byte word: big char.
;;; "P" + object1 + object2 : a pair
;;; "V" + 4-bytes(n) + object ... : a vector of length n followed by n objects
;;; "v" + 4-byte(n) + octet ... : a bytevector of length n followed by n octets
;;; "s" + 4-bytes(n) + octet ... : an ascii string
;;; "S" + 4-bytes(n) + int ... : a unicode string
;;; "M" + symbol-name : a symbol
;;; "G" + pretty-name + unique-name : a gensym
;;; "R" + rtd-name + rtd-symbol + field-count + field-names
;;; "{" + field-count + rtd + fields
;;; ">" + 4-bytes(i) : mark the next object with index i
;;; "<" + 4-bytes(i) : dereference the object marked with index i
;;; "x" : denotes code
;;; "T" : Thunk; followed by code.
;;; "r" + numerator + denominator : ratnum
;;; "f" + 8-byte : IEEE flonum
;;; "b" + 4-byte(n) + n-bytes denotes a bignum (sign is sign of n).
(library (ikarus fasl read)
(export fasl-read)
(import (except (ikarus) fasl-read)
(except (ikarus.code-objects) procedure-annotation)
(ikarus system $codes)
(ikarus system $structs))
(define who 'fasl-read)
(define (make-struct rtd n)
(import (ikarus system $fx))
(let f ([i 0] [n n] [s ($make-struct rtd n)])
(cond
[($fx= i n) s]
[else
($struct-set! s i 0)
(f ($fx+ i 1) n s)])))
(define (read-u8 p)
(let ([b (get-u8 p)])
(when (eof-object? b)
(error who "invalid eof encountered" p))
b))
(define (read-u8-as-char p)
(integer->char (read-u8 p)))
(define (assert-eq? x y)
(unless (eq? x y)
(die who
(format "Expected ~s, got ~s\n" y x))))
(define (char->int x)
(if (char? x)
(char->integer x)
(die who "unexpected eof inside a fasl object")))
(define (read-u32 p)
(let* ([c0 (read-u8 p)]
[c1 (read-u8 p)]
[c2 (read-u8 p)]
[c3 (read-u8 p)])
(bitwise-ior c0 (sll c1 8) (sll c2 16) (sll c3 24))))
(define (read-fixnum p)
(case (fixnum-width)
[(30)
(let* ([c0 (read-u8 p)]
[c1 (read-u8 p)]
[c2 (read-u8 p)]
[c3 (read-u8 p)])
(cond
[(fx<= c3 127)
(fxlogor (fxlogor (fxsra c0 2) (fxsll c1 6))
(fxlogor (fxsll c2 14) (fxsll c3 22)))]
[else
(let ([c0 (fxlogand #xFF (fxlognot c0))]
[c1 (fxlogand #xFF (fxlognot c1))]
[c2 (fxlogand #xFF (fxlognot c2))]
[c3 (fxlogand #xFF (fxlognot c3))])
(fx- -1
(fxlogor (fxlogor (fxsra c0 2)
(fxsll c1 6))
(fxlogor (fxsll c2 14)
(fxsll c3 22)))))]))]
[else
(let* ([u0 (read-u32 p)]
[u1 (read-u32 p)])
(if (<= u1 #x7FFFFFF)
(sra (bitwise-ior u0 (sll u1 32)) 3)
(let ([u0 (fxlogand #xFFFFFFFF (fxlognot u0))]
[u1 (fxlogand #xFFFFFFFF (fxlognot u1))])
(fx- -1
(fxlogor (fxsra u0 3) (fxsll u1 29))))))]))
(define (read-int p)
(case (fixnum-width)
[(30)
(let* ([c0 (char->int (read-u8-as-char p))]
[c1 (char->int (read-u8-as-char p))]
[c2 (char->int (read-u8-as-char p))]
[c3 (char->int (read-u8-as-char p))])
(cond
[(fx<= c3 127)
(fxlogor (fxlogor c0 (fxsll c1 8))
(fxlogor (fxsll c2 16) (fxsll c3 24)))]
[else
(let ([c0 (fxlogand #xFF (fxlognot c0))]
[c1 (fxlogand #xFF (fxlognot c1))]
[c2 (fxlogand #xFF (fxlognot c2))]
[c3 (fxlogand #xFF (fxlognot c3))])
(fx- -1
(fxlogor (fxlogor c0
(fxsll c1 8))
(fxlogor (fxsll c2 16)
(fxsll c3 24)))))]))]
[else
(let* ([u0 (read-u32 p)]
[u1 (read-u32 p)])
(if (<= u1 #x7FFFFFF)
(bitwise-ior u0 (sll u1 32))
(let ([u0 (fxlogand #xFFFFFFFF (fxlognot u0))]
[u1 (fxlogand #xFFFFFFFF (fxlognot u1))])
(- -1 (bitwise-ior u0 (sll u1 32))))))]))
(define (do-read p)
(define marks (make-vector 1 #f))
(define (max x y)
(if (fx> x y) x y))
(define (put-mark m obj)
(cond
[(fx< m (vector-length marks))
(when (vector-ref marks m)
(die 'fasl-read "mark set twice" m))
(vector-set! marks m obj)]
[else
(let ([n (vector-length marks)])
(let ([v (make-vector
(max (fx* n 2) (fx+ m 1))
#f)])
(let f ([i 0])
(cond
[(fx= i n)
(set! marks v)
(vector-set! marks m obj)]
[else
(vector-set! v i (vector-ref marks i))
(f (fxadd1 i))]))))]))
(define (read) (read/mark #f))
(define (read-code code-m clos-m)
(let* ([code-size (read-int p)]
[freevars (read-fixnum p)])
(let ([code (make-code code-size freevars)])
(when code-m (put-mark code-m code))
(let ([annotation (read)])
(set-code-annotation! code annotation))
(let f ([i 0])
(unless (fx= i code-size)
(code-set! code i (char->int (read-u8-as-char p)))
(f (fxadd1 i))))
(cond
[clos-m
(let ([clos ($code->closure code)])
(put-mark clos-m clos)
(set-code-reloc-vector! code (read))
code)]
[else
(set-code-reloc-vector! code (read))
code]))))
(define (read-procedure m)
(let ([c (read-u8-as-char p)])
(case c
[(#\x)
(let ([code (read-code #f m)])
(if m (vector-ref marks m) ($code->closure code)))]
[(#\<)
(let ([cm (read-u32 p)])
(unless (fx< cm (vector-length marks))
(die who "invalid mark" m))
(let ([code (vector-ref marks cm)])
(let ([proc ($code->closure code)])
(when m (put-mark m proc))
proc)))]
[(#\>)
(let ([cm (read-u32 p)])
(assert-eq? (read-u8-as-char p) #\x)
(let ([code (read-code cm m)])
(if m (vector-ref marks m) ($code->closure code))))]
[else (die who "invalid code header" c)])))
(define (read-list len m)
(let ([ls (make-list (+ len 1))])
(when m (put-mark m ls))
(let f ([ls ls])
(set-car! ls (read))
(let ([d (cdr ls)])
(if (null? d)
(set-cdr! ls (read))
(f d))))
ls))
(define (read/mark m)
(define (nom)
(when m (die who "unhandled mark")))
(let ([h (read-u8-as-char p)])
(case h
[(#\I)
(read-fixnum p)]
[(#\P)
(if m
(let ([x (cons #f #f)])
(put-mark m x)
(set-car! x (read))
(set-cdr! x (read))
x)
(let ([a (read)])
(cons a (read))))]
[(#\N) '()]
[(#\T) #t]
[(#\F) #f]
[(#\E) (eof-object)]
[(#\U) (void)]
[(#\s) ;;; string
(let ([n (read-int p)])
(let ([str (make-string n)])
(let f ([i 0])
(unless (fx= i n)
(let ([c (read-u8-as-char p)])
(string-set! str i c)
(f (fxadd1 i)))))
(when m (put-mark m str))
str))]
[(#\S) ;;; unicode string
(let ([n (read-int p)])
(let ([str (make-string n)])
(let f ([i 0])
(unless (fx= i n)
(let ([c (integer->char (read-u32 p))])
(string-set! str i c)
(f (fxadd1 i)))))
(when m (put-mark m str))
str))]
[(#\M) ;;; symbol
(let ([str (read)])
(let ([sym (string->symbol str)])
(when m (put-mark m sym))
sym))]
[(#\G)
(let* ([pretty (read)]
[unique (read)])
(let ([g (foreign-call "ikrt_strings_to_gensym" pretty unique)])
(when m (put-mark m g))
g))]
[(#\V) ;;; vector
(let ([n (read-int p)])
(let ([v (make-vector n)])
(when m (put-mark m v))
(let f ([i 0])
(unless (fx= i n)
(vector-set! v i (read))
(f (fxadd1 i))))
v))]
[(#\v) ;;; bytevector
(let ([n (read-int p)])
(let ([v (make-bytevector n)])
(when m (put-mark m v))
(let f ([i 0])
(unless (fx= i n)
(bytevector-u8-set! v i (read-u8 p))
(f (fxadd1 i))))
v))]
[(#\x) ;;; code
(read-code m #f)]
[(#\Q) ;;; procedure
(read-procedure m)]
[(#\R)
(let* ([rtd-name (read)]
[rtd-symbol (read)]
[field-count (read-int p)])
(let ([fields
(let f ([i 0])
(cond
[(fx= i field-count) '()]
[else
(let ([a (read)])
(cons a (f (fxadd1 i))))]))])
(let ([rtd (make-struct-type
rtd-name fields rtd-symbol)])
(when m (put-mark m rtd))
rtd)))]
[(#\{)
(let ([n (read-int p)])
(let ([rtd (read)])
(let ([x (make-struct rtd n)])
(when m (put-mark m x))
(let f ([i 0])
(unless (fx= i n)
($struct-set! x i (read))
(f (fxadd1 i))))
x)))]
[(#\C) (integer->char (read-int p))]
[(#\c) (read-u8-as-char p)]
[(#\>)
(let ([m (read-u32 p)])
(read/mark m))]
[(#\<)
(let ([m (read-u32 p)])
(unless (fx< m (vector-length marks))
(die who "invalid mark" m))
(or (vector-ref marks m)
(error who "uninitialized mark" m)))]
[(#\l) ;;; list of length <= 255
(read-list (read-u8 p) m)]
[(#\L) ;;; list of length > 255
(read-list (read-int p) m)]
[(#\W) ;;; r6rs record type descriptor
(let* ([name (read)]
[parent (read)]
[uid (read)]
[sealed? (read)]
[opaque? (read)]
[n (read)]
[fields (make-vector n)])
(let f ([i 0])
(cond
[(= i n)
(let ([rtd (make-record-type-descriptor
name parent uid sealed? opaque?
fields)])
(when m (put-mark m rtd))
rtd)]
[else
(let* ([field-mutable? (read)]
[field-name (read)])
(vector-set! fields i
(list (if field-mutable? 'mutable 'immutable) field-name))
(f (+ i 1)))])))]
[(#\b) ;;; bignum
(let ([i (read-int p)])
(let ([bytes (if (< i 0) (- i) i)])
(let ([bv (get-bytevector-n p bytes)])
(let ([n (bytevector-uint-ref bv 0 'little bytes)])
(let ([n (if (< i 0) (- n) n)])
(when m (put-mark m n))
n)))))]
[(#\f) ;;; flonum
(let ()
(import (ikarus system $flonums))
(let ([x ($make-flonum)])
($flonum-set! x 7 (get-u8 p))
($flonum-set! x 6 (get-u8 p))
($flonum-set! x 5 (get-u8 p))
($flonum-set! x 4 (get-u8 p))
($flonum-set! x 3 (get-u8 p))
($flonum-set! x 2 (get-u8 p))
($flonum-set! x 1 (get-u8 p))
($flonum-set! x 0 (get-u8 p))
(when m (put-mark m x))
x))]
[(#\r) ;;; ratnum
(let* ([den (read)]
[num (read)])
(let ([x (/ num den)])
(when m (put-mark m x))
x))]
[(#\i) ;;; compnum
(let* ([real (read)]
[imag (read)])
(let ([x (make-rectangular real imag)])
(when m (put-mark m x))
x))]
[(#\h #\H)
(let ([x (if (eqv? h #\h) (make-eq-hashtable) (make-eqv-hashtable))])
(when m (put-mark m x))
(let* ([keys (read)] [vals (read)])
(vector-for-each
(lambda (k v) (hashtable-set! x k v))
keys vals))
x)]
[else
(die who "Unexpected char as a fasl object header" h p)])))
(read))
(define $fasl-read
(lambda (p)
(assert-eq? (read-u8-as-char p) #\#)
(assert-eq? (read-u8-as-char p) #\@)
(assert-eq? (read-u8-as-char p) #\I)
(assert-eq? (read-u8-as-char p) #\K)
(assert-eq? (read-u8-as-char p) #\0)
(case (fixnum-width)
[(30) (assert-eq? (read-u8-as-char p) #\1)]
[else (assert-eq? (read-u8-as-char p) #\2)])
(let ([v (do-read p)])
(unless (port-eof? p)
(printf "port did not reach eof\n"))
v)))
(define fasl-read
(case-lambda
[(p)
(if (input-port? p)
($fasl-read p)
(die 'fasl-read "not an input port" p))]))
)