foreign-c/retropikzel/pffi/shared/pointer.scm

106 lines
3.8 KiB
Scheme

(cond-expand
(windows (define-c-library libc
'("stdlib.h" "string.h")
"ucrtbase"
'((additional-versions ("0" "6")))))
(else (define-c-library libc
'("stdlib.h" "string.h")
"c"
'((additional-versions ("0" "6"))))))
(define-c-procedure c-strlen libc 'strlen 'int '(pointer))
(define-c-procedure pffi-pointer-allocate-calloc libc 'calloc 'pointer '(int int))
(define-c-procedure c-memset-address->pointer libc 'memset 'pointer '(uint64 uint8 int))
(define-c-procedure c-memset-pointer->address libc 'memset 'uint64 '(pointer uint8 int))
(define-c-procedure c-printf libc 'printf 'int '(pointer pointer))
(define-c-procedure c-malloc libc 'malloc 'pointer '(int))
(define-c-procedure c-strlen libc 'strlen 'int '(pointer))
(cond-expand
(chibi #t) ; FIXME
(else (define make-c-bytevector
(lambda (k . byte)
(if (null? byte)
(c-malloc k)
(bytevector->c-bytevector (make-bytevector k (car byte))))))))
(define c-bytevector
(lambda bytes
(bytevector->c-bytevector (apply bytevector bytes))))
(cond-expand
(chibi #t) ; FIXME
(else (define-c-procedure c-free libc 'free 'void '(pointer))))
(define bytevector->c-bytevector
(lambda (bytes)
(letrec* ((bytes-length (bytevector-length bytes))
(pointer (make-c-bytevector bytes-length))
(looper (lambda (index)
(when (< index bytes-length)
(pffi-pointer-set! pointer
'uint8
index
(bytevector-u8-ref bytes index))
(looper (+ index 1))))))
(looper 0)
pointer)))
(define c-bytevector->bytevector
(lambda (pointer size)
(letrec* ((bytes (make-bytevector size))
(looper (lambda (index)
(let ((byte (pffi-pointer-get pointer 'uint8 index)))
(if (= index size)
bytes
(begin
(bytevector-u8-set! bytes index byte)
(looper (+ index 1))))))))
(looper 0))))
(define c-bytevector-string-length
(lambda (bytevector)
(c-strlen bytevector)))
(define c-bytevector->string
(lambda (pointer)
(when (not (c-bytevector? pointer))
(error "c-bytevector->string argument not c-bytevector" pointer))
(let ((size (c-strlen pointer)))
(utf8->string (c-bytevector->bytevector pointer size)))))
(define string->c-bytevector
(lambda (text)
(when (not (string? text))
(error "string->bytevector argument not string" text))
(bytevector->c-bytevector (string->utf8 (string-append text (string #\null))))))
(cond-expand
(kawa #t) ; FIXME
(chicken #t) ; FIXME
(else (define make-c-null
(lambda ()
(cond-expand (stklos (let ((pointer (make-c-bytevector 1)))
(free-bytes pointer)
pointer))
(else (c-memset-address->pointer 0 0 0)))))))
(cond-expand
(kawa #t) ; FIXME
(chicken #t) ; FIXME
(else (define c-null?
(lambda (pointer)
(if (c-bytevector? pointer)
(= (c-memset-pointer->address pointer 0 0) 0)
#f)))))
(define-syntax call-with-address-of-c-bytevector
(syntax-rules ()
((_ input-pointer thunk)
(let ((address-pointer (make-c-bytevector (c-size-of 'pointer))))
(pffi-pointer-set! address-pointer 'pointer 0 input-pointer)
(apply thunk (list address-pointer))
(set! input-pointer (pffi-pointer-get address-pointer 'pointer 0))
(c-free address-pointer)))))