duktape-1.5.2/src-separate/duk_hobject_misc.c

Go to the documentation of this file.

/*
 *  Misc support functions
 */
 
#include "duk_internal.h"
 
DUK_INTERNAL duk_bool_t duk_hobject_prototype_chain_contains(duk_hthread *thr, duk_hobject *h, duk_hobject *p, duk_bool_t ignore_loop) {
    duk_uint_t sanity;
 
    DUK_ASSERT(thr != NULL);
 
    /* False if the object is NULL or the prototype 'p' is NULL.
     * In particular, false if both are NULL (don't compare equal).
     */
    if (h == NULL || p == NULL) {
        return 0;
    }
 
    sanity = DUK_HOBJECT_PROTOTYPE_CHAIN_SANITY;
    do {
        if (h == p) {
            return 1;
        }
 
        if (sanity-- == 0) {
            if (ignore_loop) {
                break;
            } else {
                DUK_ERROR_RANGE(thr, DUK_STR_PROTOTYPE_CHAIN_LIMIT);
            }
        }
        h = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h);
    } while (h);
 
    return 0;
}
 
DUK_INTERNAL void duk_hobject_set_prototype_updref(duk_hthread *thr, duk_hobject *h, duk_hobject *p) {
#ifdef DUK_USE_REFERENCE_COUNTING
    duk_hobject *tmp;
 
    DUK_ASSERT(h);
    tmp = DUK_HOBJECT_GET_PROTOTYPE(thr->heap, h);
    DUK_HOBJECT_SET_PROTOTYPE(thr->heap, h, p);
    DUK_HOBJECT_INCREF_ALLOWNULL(thr, p);  /* avoid problems if p == h->prototype */
    DUK_HOBJECT_DECREF_ALLOWNULL(thr, tmp);
#else
    DUK_ASSERT(h);
    DUK_UNREF(thr);
    DUK_HOBJECT_SET_PROTOTYPE(thr->heap, h, p);
#endif
}