compile-r7rs/snow/retropikzel/pffi/shared/struct.scm

129 lines
5.6 KiB
Scheme

(define-record-type <pffi-struct>
(struct-make c-type size pointer members)
pffi-struct?
(c-type pffi-struct-c-type)
(size pffi-struct-size)
(pointer pffi-struct-pointer)
(members pffi-struct-members))
(define-syntax pffi-define-struct
(syntax-rules ()
((_ name c-type members)
(define name
(lambda arguments
(let* ((size-and-offsets (calculate-struct-size-and-offsets members))
(size (cdr (assoc 'size size-and-offsets)))
(offsets (cdr (assoc 'offsets size-and-offsets)))
(pointer (if (and (not (null? arguments))
(pffi-pointer? (car arguments)))
(car arguments)
(pffi-pointer-allocate size)))
(c-type-string (if (string? c-type) c-type (symbol->string c-type))))
(struct-make c-type-string size pointer offsets)))))))
(define pffi-struct-dereference
(lambda (struct)
(let ((pointer (pffi-pointer-allocate (pffi-struct-size struct)))
(offset 0))
(for-each
(lambda (struct-member)
(let* ((member-type (cadr struct-member))
(member-name (car struct-member))
(member-size (pffi-size-of member-type)))
(display "HERE: ")
(write member-size)
(newline)
(pffi-pointer-set! pointer
member-type
offset
(pffi-struct-get struct member-name))
(set! offset (+ offset member-size))))
(pffi-struct-members struct))
;(pffi-pointer-get (pffi-struct-pointer struct) 'pointer 0)
;(pffi-pointer-get pointer 'pointer 0)
pointer
)))
(define pffi-align-of
(lambda (type)
(cond-expand
;(guile (alignof (pffi-type->native-type type)))
(else (size-of-type type)))))
(define round-to-next-modulo-of
(lambda (to-round roundee)
(if (= (floor-remainder to-round roundee) 0)
to-round
(round-to-next-modulo-of (+ to-round 1) roundee))))
(define calculate-struct-size-and-offsets
(lambda (members)
(let* ((size 0)
(largest-member-size 0)
(offsets (map (lambda (member)
(let* ((name (cdr member))
(type (car member))
(type-alignment (pffi-align-of type)))
(when (> (size-of-type type) largest-member-size)
(set! largest-member-size (size-of-type type)))
(if (or (= size 0)
(= (floor-remainder size type-alignment) 0))
(begin
(set! size (+ size type-alignment))
(list name type (- size type-alignment)))
(let ((next-alignment (round-to-next-modulo-of size type-alignment)))
(set! size (+ next-alignment type-alignment))
(list name
type
next-alignment)))))
members)))
(list (cons 'size
(cond-expand
;(guile (sizeof (map pffi-type->native-type (map car members))))
(else
(if (= (modulo size largest-member-size) 0)
size
(round-to-next-modulo-of size largest-member-size)))))
(cons 'offsets offsets)))))
#;(define pffi-struct-make
(lambda (c-type members . pointer)
(for-each
(lambda (member)
(when (not (pair? member))
(error "All struct members must be pairs" (list c-type member)))
(when (not (symbol? (car member)))
(error "All struct member types must be symbols" (list c-type member)))
(when (not (symbol? (cdr member)))
(error "All struct member names must be symbols" (list c-type member))))
members)
(let* ((size-and-offsets (calculate-struct-size-and-offsets members))
(size (cdr (assoc 'size size-and-offsets)))
(offsets (cdr (assoc 'offsets size-and-offsets)))
(pointer (if (null? pointer) (pffi-pointer-allocate size) (car pointer)))
(c-type (if (string? c-type) c-type (symbol->string c-type))))
(struct-make c-type size pointer offsets))))
(define (pffi-struct-offset-get struct member-name)
(when (not (assoc member-name (pffi-struct-members struct)))
(error "Struct has no such member" (list struct member-name)))
(car (cdr (cdr (assoc member-name (pffi-struct-members struct))))))
(define (pffi-struct-get struct member-name)
(when (not (assoc member-name (pffi-struct-members struct)))
(error "Struct has no such member" (list struct member-name)))
(let ((type (car (cdr (assoc member-name (pffi-struct-members struct)))))
(offset (car (cdr (cdr (assoc member-name (pffi-struct-members struct)))))))
(map display (list "type: " type
", offset: " offset
", value: " (pffi-pointer-get (pffi-struct-pointer struct) type offset)
#\newline))
(pffi-pointer-get (pffi-struct-pointer struct) type offset)))
(define (pffi-struct-set! struct member-name value)
(when (not (assoc member-name (pffi-struct-members struct)))
(error "Struct has no such member" (list struct member-name)))
(let ((type (car (cdr (assoc member-name (pffi-struct-members struct)))))
(offset (car (cdr (cdr (assoc member-name (pffi-struct-members struct)))))))
(pffi-pointer-set! (pffi-struct-pointer struct) type offset value)))