v7_next_prop - No property attributes being returned about v7 HOT 10 CLOSED

#include <stdio.h>
#include "v7.h"

int main(void) {
  enum v7_err rcode = V7_OK;
  struct v7 *v7 = v7_create();

  v7_val_t obj = v7_mk_object(v7);
  v7_def(v7, obj, "foo", ~0, 0, v7_mk_number(v7, 42));
  v7_def(v7, obj, "bar", ~0, V7_DESC_ENUMERABLE(0), v7_mk_number(v7, 42));

  printf("obj stringifies as: ");
  v7_println(v7, obj);

  printf("iterating properties with v7_next_prop:\n");
  struct prop_iter_ctx ctx;
  v7_val_t name, val;
  v7_prop_attr_t attrs;

  v7_init_prop_iter_ctx(v7, obj, &ctx);
  while (v7_next_prop(v7, &ctx, &name, &val, &attrs)) {
    printf("prop name: ");
    v7_print(v7, name);
    printf(", attrs: %d\n", attrs);
  }
  v7_destruct_prop_iter_ctx(v7, &ctx);

  v7_destroy(v7);
  return (int) rcode;
}

/*
 * Property attributes bitmask
 */
typedef unsigned short v7_prop_attr_t;
#define V7_PROPERTY_NON_WRITABLE (1 << 0)
#define V7_PROPERTY_NON_ENUMERABLE (1 << 1)
#define V7_PROPERTY_NON_CONFIGURABLE (1 << 2)
#define V7_PROPERTY_GETTER (1 << 3)
#define V7_PROPERTY_SETTER (1 << 4)
#define _V7_PROPERTY_HIDDEN (1 << 5)
/* property not managed by V7 HEAP */
#define _V7_PROPERTY_OFF_HEAP (1 << 6)
/* special property holding user data and destructor cb */
#define _V7_PROPERTY_USER_DATA_AND_DESTRUCTOR (1 << 7)
/*
 * not a property attribute, but a flag for `v7_def()`. It's here in order to
 * keep all offsets in one place
 */
#define _V7_DESC_PRESERVE_VALUE (1 << 8)

/*
 * Internal helpers for `V7_DESC_...` macros
 */
#define _V7_DESC_SHIFT 16
#define _V7_DESC_MASK ((1 << _V7_DESC_SHIFT) - 1)
#define _V7_MK_DESC(v, n) \
  (((v7_prop_attr_desc_t)(n)) << _V7_DESC_SHIFT | ((v) ? (n) : 0))
#define _V7_MK_DESC_INV(v, n) _V7_MK_DESC(!(v), (n))

/*
 * Property attribute descriptors that may be given to `v7_def()`: for each
 * attribute (`v7_prop_attr_t`), there is a corresponding macro, which takes
 * param: either 1 (set attribute) or 0 (clear attribute). If some particular
 * attribute isn't mentioned at all, it's left unchanged (or default, if the
 * property is being created)
 *
 * There is additional flag: `V7_DESC_PRESERVE_VALUE`. If it is set, the
 * property value isn't changed (or set to `undefined` if the property is being
 * created)
 */
typedef unsigned long v7_prop_attr_desc_t;
#define V7_DESC_WRITABLE(v) _V7_MK_DESC_INV(v, V7_PROPERTY_NON_WRITABLE)
#define V7_DESC_ENUMERABLE(v) _V7_MK_DESC_INV(v, V7_PROPERTY_NON_ENUMERABLE)
#define V7_DESC_CONFIGURABLE(v) _V7_MK_DESC_INV(v, V7_PROPERTY_NON_CONFIGURABLE)
#define V7_DESC_GETTER(v) _V7_MK_DESC(v, V7_PROPERTY_GETTER)
#define V7_DESC_SETTER(v) _V7_MK_DESC(v, V7_PROPERTY_SETTER)
#define V7_DESC_PRESERVE_VALUE _V7_DESC_PRESERVE_VALUE

.....

static v7_prop_attr_t apply_attrs_desc(v7_prop_attr_desc_t attrs_desc,
                                       v7_prop_attr_t old_attrs) {
  v7_prop_attr_t ret = old_attrs;
  if (old_attrs & V7_PROPERTY_NON_CONFIGURABLE) {
    /*
     * The property is non-configurable: we can only change it from being
     * writable to non-writable
     */

    if ((attrs_desc >> _V7_DESC_SHIFT) & V7_PROPERTY_NON_WRITABLE &&
        (attrs_desc & V7_PROPERTY_NON_WRITABLE)) {
      ret |= V7_PROPERTY_NON_WRITABLE;
    }

  } else {
    /* The property is configurable: we can change any attributes */
    ret = (old_attrs & ~(attrs_desc >> _V7_DESC_SHIFT)) |
          (attrs_desc & _V7_DESC_MASK);
  }

  return ret;
}