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7387c231ee
* module/system/foreign.scm (parse-c-struct): Update use of
`pointer->bytevector' to the new API.
* test-suite/tests/foreign.test ("structs"): New test prefix.
132 lines
4.1 KiB
Scheme
132 lines
4.1 KiB
Scheme
;;;; Copyright (C) 2010 Free Software Foundation, Inc.
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;;;;
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;;;; This library is free software; you can redistribute it and/or
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;;;; modify it under the terms of the GNU Lesser General Public
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;;;; License as published by the Free Software Foundation; either
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;;;; version 2.1 of the License, or (at your option) any later version.
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;;;;
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;;;; This library 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 GNU
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;;;; Lesser General Public License for more details.
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;;;;
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;;;; You should have received a copy of the GNU Lesser General Public
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;;;; License along with this library; if not, write to the Free Software
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;;;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
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;;;;
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(define-module (system foreign)
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#:use-module (rnrs bytevectors)
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#:use-module (srfi srfi-1)
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#:export (void
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float double
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int unsigned-int long unsigned-long size_t
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int8 uint8
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uint16 int16
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uint32 int32
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uint64 int64
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sizeof alignof
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%null-pointer
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null-pointer?
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make-pointer
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pointer-address
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dereference-pointer
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pointer->bytevector
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bytevector->pointer
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set-pointer-finalizer!
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make-foreign-function
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make-c-struct parse-c-struct))
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(load-extension (string-append "libguile-" (effective-version))
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"scm_init_foreign")
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;;;
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;;; Pointers.
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;;;
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(define (null-pointer? pointer)
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"Return true if POINTER is the null pointer."
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(= (pointer-address pointer) 0))
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;;;
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;;; Structures.
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;;;
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(define *writers*
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`((,float . ,bytevector-ieee-single-native-set!)
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(,double . ,bytevector-ieee-double-native-set!)
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(,int8 . ,bytevector-s8-set!)
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(,uint8 . ,bytevector-u8-set!)
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(,int16 . ,bytevector-s16-native-set!)
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(,uint16 . ,bytevector-u16-native-set!)
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(,int32 . ,bytevector-s32-native-set!)
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(,uint32 . ,bytevector-u32-native-set!)
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(,int64 . ,bytevector-s64-native-set!)
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(,uint64 . ,bytevector-u64-native-set!)))
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(define *readers*
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`((,float . ,bytevector-ieee-single-native-ref)
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(,double . ,bytevector-ieee-double-native-ref)
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(,int8 . ,bytevector-s8-ref)
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(,uint8 . ,bytevector-u8-ref)
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(,int16 . ,bytevector-s16-native-ref)
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(,uint16 . ,bytevector-u16-native-ref)
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(,int32 . ,bytevector-s32-native-ref)
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(,uint32 . ,bytevector-u32-native-ref)
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(,int64 . ,bytevector-s64-native-ref)
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(,uint64 . ,bytevector-u64-native-ref)))
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(define (align off alignment)
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(1+ (logior (1- off) (1- alignment))))
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(define (write-c-struct bv offset types vals)
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(let lp ((offset offset) (types types) (vals vals))
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(cond
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((not (pair? types))
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(or (null? vals)
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(error "too many values" vals)))
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((not (pair? vals))
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(error "too few values" types))
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(else
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;; alignof will error-check
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(let* ((type (car types))
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(offset (align offset (alignof type))))
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(if (pair? type)
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(write-c-struct bv offset (car types) (car vals))
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((assv-ref *writers* type) bv offset (car vals)))
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(lp (+ offset (sizeof type)) (cdr types) (cdr vals)))))))
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(define (read-c-struct bv offset types)
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(let lp ((offset offset) (types types) (vals '()))
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(cond
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((not (pair? types))
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(reverse vals))
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(else
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;; alignof will error-check
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(let* ((type (car types))
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(offset (align offset (alignof type))))
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(lp (+ offset (sizeof type)) (cdr types)
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(cons (if (pair? type)
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(read-c-struct bv offset (car types))
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((assv-ref *readers* type) bv offset))
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vals)))))))
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(define (make-c-struct types vals)
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(let ((bv (make-bytevector (sizeof types) 0)))
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(write-c-struct bv 0 types vals)
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(bytevector->pointer bv)))
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(define (parse-c-struct foreign types)
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(let ((size (fold (lambda (type total)
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(+ (sizeof type) total))
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0
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types)))
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(read-c-struct (pointer->bytevector foreign size) 0 types)))
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