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7b107cceb9
* module/language/assembly/Makefile.am: * module/language/assembly/spec.scm: * module/language/assembly/decompile-bytecode.scm: Add a bytecode decompiler. Neat! * module/language/bytecode/spec.scm (decompile-objcode): * module/language/objcode/spec.scm (decompile-value): Add some "decompilers" here too. * module/system/base/compile.scm (current-language): Since we can refer to languages by name, do so here -- removes the previous anti-circularity hack. (compile-file, compile): Refer to target languages by name. (decompile): New public function. Neat! * module/system/base/language.scm (lookup-decompilation-order): Fix so we look for decompilers with the high-level language definition.
85 lines
3.2 KiB
Scheme
85 lines
3.2 KiB
Scheme
;;; Guile VM code converters
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;; Copyright (C) 2001 Free Software Foundation, Inc.
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;; This program is free software; you can redistribute it and/or modify
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;; it under the terms of the GNU General Public License as published by
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;; the Free Software Foundation; either version 2, or (at your option)
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;; any later version.
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;;
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;; This program is distributed in the hope that it will be useful,
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;; but WITHOUT ANY WARRANTY; without even the implied warranty of
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;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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;; GNU General Public License for more details.
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;;
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;; You should have received a copy of the GNU General Public License
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;; along with this program; see the file COPYING. If not, write to
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;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
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;; Boston, MA 02111-1307, USA.
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;;; Code:
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(define-module (language assembly decompile-bytecode)
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#:use-module (system vm instruction)
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#:use-module (system base pmatch)
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#:use-module (srfi srfi-4)
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#:use-module (language assembly)
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#:export (decompile-bytecode))
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(define (decompile-bytecode x env opts)
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(let ((i 0) (size (u8vector-length x)))
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(define (pop)
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(let ((b (cond ((< i size) (u8vector-ref x i))
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((= i size) #f)
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(else (error "tried to decode too many bytes")))))
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(if b (set! i (1+ i)))
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b))
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(let ((ret (decode-load-program pop)))
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(if (= i size)
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(values ret env)
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(error "bad bytecode: only decoded ~a out of ~a bytes" i size)))))
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(define (decode-load-program pop)
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(let* ((nargs (pop)) (nrest (pop)) (nlocs (pop)) (nexts (pop))
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(a (pop)) (b (pop)) (c (pop)) (d (pop))
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(len (+ a (ash b 8) (ash c 16) (ash d 24)))
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(i 0))
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(define (sub-pop) ;; ...records. ha. ha.
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(let ((b (cond ((< i len) (pop))
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((= i len) #f)
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(else (error "tried to decode too many bytes")))))
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(if b (set! i (1+ i)))
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b))
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(let lp ((out '()))
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(cond ((> i len)
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(error "error decoding program -- read too many bytes" out))
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((= i len)
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`(load-program ,nargs ,nrest ,nlocs ,nexts () ,len
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,@(reverse! out)))
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(else
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(let ((exp (decode-bytecode sub-pop)))
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;; replace with labels?
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(lp (cons exp out))))))))
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(define (decode-bytecode pop)
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(and=> (pop)
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(lambda (opcode)
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(let ((inst (opcode->instruction opcode)))
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(cond
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((eq? inst 'load-program)
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(decode-load-program pop))
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((< (instruction-length inst) 0)
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(let* ((len (decode-length pop))
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(str (make-string len)))
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(let lp ((i 0))
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(if (= i len)
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`(,inst ,str)
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(begin
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(string-set! str i (integer->char (pop)))
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(lp (1+ i)))))))
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(else
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;; fixed length
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(let lp ((n (instruction-length inst)) (out (list inst)))
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(if (zero? n)
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(reverse! out)
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(lp (1- n) (cons (pop) out))))))))))
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