cat foo.h foo.c make-shared-lib.sh foo.l example-foo.l
#ifndef foo_h__
#define foo_h__

struct Rect
{
  int x,y;
  int w,h;
};

void foo(struct Rect *r);

#endif  // foo_h__
/* module foo.c */
#include <stdio.h>
#include "foo.h"

void foo(struct Rect *r)
{
    printf("Hello from foo!\n");
    printf("rect.x=%d\n", r->x);
    printf("rect.y=%d\n", r->y);
    printf("rect.w=%d\n", r->w);
    printf("rect.h=%d\n", r->h);
}
/* module foo.c */
#!/bin/sh
rm -f libfoo.so foo.o
gcc -c -Wall -Werror -fpic foo.c && gcc -shared -o libfoo.so foo.o
#end of script make-share-foolib.sh
######### foo.l ########################
(default
   *foolib "./libfoo.so")


(de foo (x y w h)
    #segfaults on calling of foo with params
    #(native `*foolib "foo" 'N (list NIL (16) (list (x . 4) (y . 4) (cons w 4) (cons h 4)))))

    #calls foo, but values are incorrect
    (native `*foolib "foo" 'N (list NIL (16) (list (4 . x) (4 . y) (cons 4 w) (cons 4 h)))))

######### foo.l ########################
####### example-foo.l ##################
(load "foo.l")
(foo 2132 32321 43432 43433)
########################################