;;; Guile VM assembler
;; Copyright (C) 2001, 2009, 2010, 2011, 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 assembly compile-bytecode)
#:use-module (system base pmatch)
#:use-module (system base target)
#:use-module (language assembly)
#:use-module (system vm instruction)
#:use-module (rnrs bytevectors)
#:use-module ((srfi srfi-1) #:select (fold))
#:export (compile-bytecode))
(define (compile-bytecode assembly env . opts)
(define-syntax-rule (define-inline1 (proc arg) body body* ...)
(define-syntax proc
(syntax-rules ()
((_ (arg-expr (... ...)))
(let ((x (arg-expr (... ...))))
(proc x)))
((_ arg)
(begin body body* ...)))))
(define (fill-bytecode bv target-endianness)
(let ((pos 0))
(define-inline1 (write-byte b)
(bytevector-u8-set! bv pos b)
(set! pos (1+ pos)))
(define u32-bv (make-bytevector 4))
(define-inline1 (write-int24-be x)
(bytevector-s32-set! u32-bv 0 x (endianness big))
(bytevector-u8-set! bv pos (bytevector-u8-ref u32-bv 1))
(bytevector-u8-set! bv (+ pos 1) (bytevector-u8-ref u32-bv 2))
(bytevector-u8-set! bv (+ pos 2) (bytevector-u8-ref u32-bv 3))
(set! pos (+ pos 3)))
(define-inline1 (write-uint32-be x)
(bytevector-u32-set! bv pos x (endianness big))
(set! pos (+ pos 4)))
(define-inline1 (write-uint32 x)
(bytevector-u32-set! bv pos x target-endianness)
(set! pos (+ pos 4)))
(define-inline1 (write-loader-len len)
(bytevector-u8-set! bv pos (ash len -16))
(bytevector-u8-set! bv (+ pos 1) (logand (ash len -8) 255))
(bytevector-u8-set! bv (+ pos 2) (logand len 255))
(set! pos (+ pos 3)))
(define-inline1 (write-latin1-string s)
(let ((len (string-length s)))
(write-loader-len len)
(let lp ((i 0))
(if (< i len)
(begin
(bytevector-u8-set! bv (+ pos i)
(char->integer (string-ref s i)))
(lp (1+ i)))))
(set! pos (+ pos len))))
(define-inline1 (write-bytevector bv*)
(let ((len (bytevector-length bv*)))
(write-loader-len len)
(bytevector-copy! bv* 0 bv pos len)
(set! pos (+ pos len))))
(define-inline1 (write-wide-string s)
(write-bytevector (string->utf32 s target-endianness)))
(define-inline1 (write-break label)
(let ((offset (- (assq-ref labels label) (+ (get-addr) 3))))
(cond ((>= offset (ash 1 23)) (error "jump too far forward" offset))
((< offset (- (ash 1 23))) (error "jump too far backwards" offset))
(else (write-int24-be offset)))))
(define (write-bytecode asm labels address emit-opcode?)
;; Write ASM's bytecode to BV. If EMIT-OPCODE? is false, don't
;; emit bytecode for the first opcode encountered. Assume code
;; starts at ADDRESS (an integer). LABELS is assumed to be an
;; alist mapping labels to addresses.
(define get-addr
(let ((start pos))
(lambda ()
(+ address (- pos start)))))
(define (write-break label)
(let ((offset (- (assq-ref labels label) (+ (get-addr) 3))))
(cond ((>= offset (ash 1 23)) (error "jump too far forward" offset))
((< offset (- (ash 1 23))) (error "jump too far backwards" offset))
(else (write-int24-be offset)))))
(let ((inst (car asm))
(args (cdr asm)))
(let ((opcode (instruction->opcode inst))
(len (instruction-length inst)))
(if emit-opcode?
(write-byte opcode))
(pmatch asm
((load-program ,labels ,length ,meta . ,code)
(write-uint32 length)
(write-uint32 (if meta (1- (byte-length meta)) 0))
(fold (lambda (asm address)
(let ((start pos))
(write-bytecode asm labels address #t)
(+ address (- pos start))))
0
code)
(if meta
;; Don't emit the `load-program' byte for metadata. Note that
;; META's bytecode meets the alignment requirements of
;; `scm_objcode', thanks to the alignment computed in `(language
;; assembly)'.
(write-bytecode meta '() 0 #f)))
((make-char32 ,x) (write-uint32-be x))
((load-number ,str) (write-latin1-string str))
((load-string ,str) (write-latin1-string str))
((load-wide-string ,str) (write-wide-string str))
((load-symbol ,str) (write-latin1-string str))
((load-array ,bv) (write-bytevector bv))
((br ,l) (write-break l))
((br-if ,l) (write-break l))
((br-if-not ,l) (write-break l))
((br-if-eq ,l) (write-break l))
((br-if-not-eq ,l) (write-break l))
((br-if-null ,l) (write-break l))
((br-if-not-null ,l) (write-break l))
((br-if-nargs-ne ,hi ,lo ,l) (write-byte hi) (write-byte lo) (write-break l))
((br-if-nargs-lt ,hi ,lo ,l) (write-byte hi) (write-byte lo) (write-break l))
((br-if-nargs-gt ,hi ,lo ,l) (write-byte hi) (write-byte lo) (write-break l))
((bind-optionals/shuffle-or-br ,nreq-hi ,nreq-lo
,nreq-and-nopt-hi ,nreq-and-nopt-lo
,ntotal-hi ,ntotal-lo
,l)
(write-byte nreq-hi)
(write-byte nreq-lo)
(write-byte nreq-and-nopt-hi)
(write-byte nreq-and-nopt-lo)
(write-byte ntotal-hi)
(write-byte ntotal-lo)
(write-break l))
((mv-call ,n ,l) (write-byte n) (write-break l))
((prompt ,escape-only? ,l) (write-byte escape-only?) (write-break l))
(else
(cond
((< len 0)
(error "unhanded variable-length instruction" asm))
((not (= (length args) len))
(error "bad number of args to instruction" asm len))
(else
(for-each (lambda (x) (write-byte x)) args))))))))
;; Don't emit the `load-program' byte.
(write-bytecode assembly '() 0 #f)
(if (= pos (bytevector-length bv))
(values bv env env)
(error "failed to fill bytevector" bv pos
(bytevector-length bv)))))
(pmatch assembly
((load-program ,labels ,length ,meta . ,code)
(fill-bytecode (make-bytevector (+ 4 4 length
(if meta
(1- (byte-length meta))
0)))
(target-endianness)))
(else (error "bad assembly" assembly))))