Hi All,
I am working on a ffi-helper: a program that will read in a C dot-h file and
generate a Guile dot-scm file which
defines a module to provide hooks into the associated C library. My goal is to
have something to release ~Oct 2017.
I have now been able to compile-ffi the following on my Mac. There is some
non-standard C syntax in sys/cdefs.h
that is driving me crazy, but I have a hack around it (see inc-help below).
I’m sure there are numerous bugs.
(define-ffi-module (cairo cairo)
#:pkg-config "cairo"
#:include '("cairo.h"
"cairo-pdf.h"
"cairo-svg.h"
)
#:inc-help (cond
((string-contains %host-type "darwin")
'(("__builtin" "__builtin_va_list=void*")
("sys/cdefs.h" "__DARWIN_ALIAS(X)=")))
(else '()))
;; the following are bent pipe to scm-module
#:export (make-cairo-unit-matrix)
)
(define (make-cairo-unit-matrix)
(make-cairo_matrix_t #(1.0 0.0 0.0 1.0 0.0 0.0)))
Some of the other Cairo headers (e.g., cairo-ft.h) give me problems with the
rat’s nest under /usr/include.
However, the above generates 397 FFI declarations into a cairo.scm file which
is about 6000 lines long. I’m not
sure if I want to start testing this code or start converting suggestions and
have guile-users do some testing.
Matt
P.S. Here is some sample code from the auto-generated file cairo/cairo.scm.
Notice that the helper includes the original C declarations as comments.
;; typedef struct _cairo_device cairo_device_t;
(define-fh-pointer-type cairo_device_t*)
;; union _cairo_path_data_t {
;; struct {
;; cairo_path_data_type_t type;
;; int length;
;; } header;
;; struct {
;; double x, y;
;; } point;
;; };
(define cairo_path_data_t-desc
(bs:union
(list `(header
,(bs:struct
(list `(type ,cairo_path_data_type_t-desc)
`(length ,int))))
`(point ,(bs:struct (list `(y ,double) `(x ,double)))))))
(export cairo_path_data_t-desc)
(define-fh-bytestructure-type/p cairo_path_data_t cairo_path_data_t-desc)
(define union-_cairo_path_data_t cairo_path_data_t)
;; typedef enum _cairo_path_data_type {
;; CAIRO_PATH_MOVE_TO,
;; CAIRO_PATH_LINE_TO,
;; CAIRO_PATH_CURVE_TO,
;; CAIRO_PATH_CLOSE_PATH,
;; } cairo_path_data_type_t;
(define-fh-enum-type cairo_path_data_type_t
'((CAIRO_PATH_MOVE_TO . 0)
(CAIRO_PATH_LINE_TO . 1)
(CAIRO_PATH_CURVE_TO . 2)
(CAIRO_PATH_CLOSE_PATH . 3))
)
;; typedef void (*cairo_destroy_func_t)(void *data);
(define (wrap-cairo_destroy_func_t proc) ;; => pointer
(ffi:procedure->pointer ffi:void proc (list '*))
)
(export wrap-cairo_destroy_func_t)
;; cairo_status_t cairo_device_set_user_data(cairo_device_t *device, const
;; cairo_user_data_key_t *key, void *user_data, cairo_destroy_func_t
;; destroy);
(define cairo_device_set_user_data
(let ((~f (ffi:pointer->procedure
ffi:int
(lib-func "cairo_device_set_user_data")
(list '* '* '* '*))))
(lambda (device key user_data destroy)
(let ((~device (unwrap-cairo_device_t* device))
(~key (unwrap-cairo_user_data_key_t* key))
(~user_data (unwrap~pointer user_data))
(~destroy (unwrap-cairo_destroy_func_t destroy)))
(wrap-cairo_status_t
(~f ~device ~key ~user_data ~destroy))))))
(export cairo_device_set_user_data)
