On 11/22/20 2:50 PM, Tim Meehan wrote:
I tried to boil this question down to the most simple thing that
represented what I needed to understand. I have had luck getting C
functions that expect arguments "by value," but "by reference" has been
problematic.
The failure mode is "Segmentation Fault," so I gather that I may not be
using the right Guile call at all.
The Guile user manual is usually quite excellent, but I seem to be missing
something important.
Thanks,
;;----------------------------------------------------------------------------;;
;; C source for "libstuff.so":
;; file stuff.c, compiled as:
;; gcc stuff.c -o libstuff.so -fPIC -shared
#|
void int_ptr_example1(int *a) {
*a = 5;
}
|#
You'll need to make-bytevector a bytevector that holds sizeof(int) bytes.
Then pass (bytevector->pointer <obj>) as the argument.
(let ((obj (make-bytevector (sizeof int))))
(int-ptr-example (bytevector->pointer obj)))
Now the 5 should be in the bytevector. You will need to extract it.
