jsobj.c

Swfdec still is development software, but has also followed a rigid no-crashes-allowed policy. I b

    jsval v;

    if (!JS_ReportErrorFlagsAndNumber(cx,
                                      JSREPORT_WARNING | JSREPORT_STRICT,
                                      js_GetErrorMessage, NULL,
                                      JSMSG_DEPRECATED_USAGE,
                                      js_WithClass.name)) {
        return JS_FALSE;
    }

    if (!(cx->fp->flags & JSFRAME_CONSTRUCTING)) {
        obj = js_NewObject(cx, &js_WithClass, NULL, NULL);
        if (!obj)
            return JS_FALSE;
        *rval = OBJECT_TO_JSVAL(obj);
    }

    parent = cx->fp->scopeChain;
    if (argc > 0) {
        if (!js_ValueToObject(cx, argv[0], &proto))
            return JS_FALSE;
        v = OBJECT_TO_JSVAL(proto);
        if (!obj_setSlot(cx, obj, INT_TO_JSVAL(JSSLOT_PROTO), &v))
            return JS_FALSE;
        if (argc > 1) {
            if (!js_ValueToObject(cx, argv[1], &parent))
                return JS_FALSE;
        }
    }
    v = OBJECT_TO_JSVAL(parent);
    return obj_setSlot(cx, obj, INT_TO_JSVAL(JSSLOT_PARENT), &v);
}
#endif

JSObject *
js_InitObjectClass(JSContext *cx, JSObject *obj)
{
    JSObject *proto;
    jsval eval;

#if JS_HAS_SHARP_VARS
    JS_ASSERT(sizeof(jsatomid) * JS_BITS_PER_BYTE >= ATOM_INDEX_LIMIT_LOG2 + 1);
#endif

    proto = JS_InitClass(cx, obj, NULL, &js_ObjectClass, Object, 1,
                         object_props, object_methods, NULL, NULL);
    if (!proto)
        return NULL;

#if JS_HAS_OBJ_PROTO_PROP
    if (!JS_InitClass(cx, obj, NULL, &js_WithClass, With, 0,
                      NULL, NULL, NULL, NULL)) {
        return NULL;
    }
#endif

    /* ECMA (15.1.2.1) says 'eval' is also a property of the global object. */
    if (!OBJ_GET_PROPERTY(cx, proto, (jsid)cx->runtime->atomState.evalAtom,
                          &eval)) {
        return NULL;
    }
    if (!OBJ_DEFINE_PROPERTY(cx, obj, (jsid)cx->runtime->atomState.evalAtom,
                             eval, NULL, NULL, 0, NULL)) {
        return NULL;
    }

    return proto;
}

void
js_InitObjectMap(JSObjectMap *map, jsrefcount nrefs, JSObjectOps *ops,
                 const JSClass *clasp)
{
    map->nrefs = nrefs;
    map->ops = ops;
    map->nslots = JS_INITIAL_NSLOTS;
    map->freeslot = JSSLOT_FREE(clasp);
}

JSObjectMap *
js_NewObjectMap(JSContext *cx, jsrefcount nrefs, JSObjectOps *ops,
                const JSClass *clasp, JSObject *obj)
{
    return (JSObjectMap *) js_NewScope(cx, nrefs, ops, clasp, obj);
}

void
js_DestroyObjectMap(JSContext *cx, JSObjectMap *map)
{
    js_DestroyScope(cx, (JSScope *)map);
}

JSObjectMap *
js_HoldObjectMap(JSContext *cx, JSObjectMap *map)
{
    JS_ASSERT(map->nrefs >= 0);
    JS_ATOMIC_INCREMENT(&map->nrefs);
    return map;
}

JSObjectMap *
js_DropObjectMap(JSContext *cx, JSObjectMap *map, JSObject *obj)
{
    JS_ASSERT(map->nrefs > 0);
    JS_ATOMIC_DECREMENT(&map->nrefs);
    if (map->nrefs == 0) {
        map->ops->destroyObjectMap(cx, map);
        return NULL;
    }
    if (MAP_IS_NATIVE(map) && ((JSScope *)map)->object == obj)
        ((JSScope *)map)->object = NULL;
    return map;
}

static JSBool
GetClassPrototype(JSContext *cx, JSObject *scope, const char *name,
                  JSObject **protop);

JSObject *
js_NewObject(JSContext *cx, const JSClass *clasp, JSObject *proto, JSObject *parent)
{
    JSObject *obj, *ctor;
    JSObjectOps *ops;
    JSObjectMap *map;
    jsval cval;
    uint32 nslots, i;
    jsval *newslots;

    /* Allocate an object from the GC heap and zero it. */
    obj = (JSObject *) js_AllocGCThing(cx, GCX_OBJECT);
    if (!obj)
        return NULL;

    /* Bootstrap the ur-object, and make it the default prototype object. */
    if (!proto) {
        if (!GetClassPrototype(cx, parent, clasp->name, &proto))
            goto bad;
        if (!proto && !GetClassPrototype(cx, parent, js_Object_str, &proto))
            goto bad;
    }

    /* Always call the class's getObjectOps hook if it has one. */
    ops = clasp->getObjectOps
          ? clasp->getObjectOps(cx, clasp)
          : &js_ObjectOps;

    /*
     * Share proto's map only if it has the same JSObjectOps, and only if
     * proto's class has the same private and reserved slots, as obj's map
     * and class have.
     */
    if (proto &&
        (map = proto->map)->ops == ops &&
        ((clasp->flags ^ OBJ_GET_CLASS(cx, proto)->flags) &
         (JSCLASS_HAS_PRIVATE |
          (JSCLASS_RESERVED_SLOTS_MASK << JSCLASS_RESERVED_SLOTS_SHIFT)))
        == 0) {
        /* Default parent to the parent of the prototype's constructor. */
        if (!parent) {
            if (!OBJ_GET_PROPERTY(cx, proto,
                                  (jsid)cx->runtime->atomState.constructorAtom,
                                  &cval)) {
                goto bad;
            }
            if (JSVAL_IS_OBJECT(cval) && (ctor = JSVAL_TO_OBJECT(cval)) != NULL)
                parent = OBJ_GET_PARENT(cx, ctor);
        }

        /* Share the given prototype's map. */
        obj->map = js_HoldObjectMap(cx, map);

        /* Ensure that obj starts with the minimum slots for clasp. */
        nslots = JS_INITIAL_NSLOTS;
    } else {
        /* Leave parent alone.  Allocate a new map for obj. */
        map = ops->newObjectMap(cx, 1, ops, clasp, obj);
        if (!map)
            goto bad;
        obj->map = map;

        /* Let ops->newObjectMap set nslots so as to reserve slots. */
        nslots = map->nslots;
    }

    /* Allocate a slots vector, with a -1'st element telling its length. */
    newslots = (jsval *) JS_malloc(cx, (nslots + 1) * sizeof(jsval));
    if (!newslots) {
        js_DropObjectMap(cx, obj->map, obj);
        obj->map = NULL;
        goto bad;
    }
    newslots[0] = nslots;
    newslots++;

    /* Set the proto, parent, and class properties. */
    newslots[JSSLOT_PROTO] = OBJECT_TO_JSVAL(proto);
    newslots[JSSLOT_PARENT] = OBJECT_TO_JSVAL(parent);
    newslots[JSSLOT_CLASS] = PRIVATE_TO_JSVAL(clasp);

    /* Clear above JSSLOT_CLASS so the GC doesn't load uninitialized memory. */
    for (i = JSSLOT_CLASS + 1; i < nslots; i++)
        newslots[i] = JSVAL_VOID;

    /* Store newslots after initializing all of 'em, just in case. */
    obj->slots = newslots;

    if (cx->runtime->objectHook)
        cx->runtime->objectHook(cx, obj, JS_TRUE, cx->runtime->objectHookData);

    return obj;

bad:
    cx->newborn[GCX_OBJECT] = NULL;
    return NULL;
}

static JSBool
FindConstructor(JSContext *cx, JSObject *scope, const char *name, jsval *vp)
{
    JSAtom *atom;
    JSObject *obj;
    JSObject *pobj;
    JSScopeProperty *sprop;

    atom = js_Atomize(cx, name, strlen(name), 0);
    if (!atom)
        return JS_FALSE;

    if (scope || (cx->fp && (scope = cx->fp->scopeChain) != NULL)) {
        /* Find the topmost object in the scope chain. */
        do {
            obj = scope;
            scope = OBJ_GET_PARENT(cx, obj);
        } while (scope);
    } else {
        obj = cx->globalObject;
        if (!obj) {
            *vp = JSVAL_VOID;
            return JS_TRUE;
        }
    }

    JS_ASSERT(OBJ_IS_NATIVE(obj));
    if (!js_LookupPropertyWithFlags(cx, obj, (jsid)atom, JSRESOLVE_CLASSNAME,
                                    &pobj, (JSProperty **)&sprop
#if defined JS_THREADSAFE && defined DEBUG
                                    , __FILE__, __LINE__
#endif
                                    )) {
        return JS_FALSE;
    }
    if (!sprop)  {
        *vp = JSVAL_VOID;
        return JS_TRUE;
    }

    JS_ASSERT(OBJ_IS_NATIVE(pobj));
    JS_ASSERT(SPROP_HAS_VALID_SLOT(sprop, OBJ_SCOPE(pobj)));
    *vp = OBJ_GET_SLOT(cx, pobj, sprop->slot);
    OBJ_DROP_PROPERTY(cx, pobj, (JSProperty *)sprop);
    return JS_TRUE;
}

JSObject *
js_ConstructObject(JSContext *cx, JSClass *clasp, JSObject *proto,
                   JSObject *parent, uintN argc, jsval *argv)
{
    jsval cval, rval;
    JSObject *obj, *ctor;

    if (!FindConstructor(cx, parent, clasp->name, &cval))
        return NULL;
    if (JSVAL_IS_PRIMITIVE(cval)) {
        js_ReportIsNotFunction(cx, &cval, JSV2F_CONSTRUCT | JSV2F_SEARCH_STACK);
        return NULL;
    }

    /*
     * If proto or parent are NULL, set them to Constructor.prototype and/or
     * Constructor.__parent__, just like JSOP_NEW does.
     */
    ctor = JSVAL_TO_OBJECT(cval);
    if (!parent)
        parent = OBJ_GET_PARENT(cx, ctor);
    if (!proto) {
        if (!OBJ_GET_PROPERTY(cx, ctor,
                              (jsid)cx->runtime->atomState.classPrototypeAtom,
                              &rval)) {
            return NULL;
        }
        if (JSVAL_IS_OBJECT(rval))
            proto = JSVAL_TO_OBJECT(rval);
    }

    obj = js_NewObject(cx, clasp, proto, parent);
    if (!obj)
        return NULL;

    if (!js_InternalConstruct(cx, obj, cval, argc, argv, &rval))
        goto bad;
    return JSVAL_IS_OBJECT(rval) ? JSVAL_TO_OBJECT(rval) : obj;
bad:
    cx->newborn[GCX_OBJECT] = NULL;
    return NULL;
}

void
js_FinalizeObject(JSContext *cx, JSObject *obj)
{
    JSObjectMap *map;

    /* Cope with stillborn objects that have no map. */
    map = obj->map;
    if (!map)
        return;
    JS_ASSERT(obj->slots);

    if (cx->runtime->objectHook)
        cx->runtime->objectHook(cx, obj, JS_FALSE, cx->runtime->objectHookData);

    /* Remove all watchpoints with weak links to obj. */
    JS_ClearWatchPointsForObject(cx, obj);

    /*
     * Finalize obj first, in case it needs map and slots.  Optimized to use
     * LOCKED_OBJ_GET_CLASS instead of OBJ_GET_CLASS, so we avoid "promoting"
     * obj's scope from lock-free to lock-full (see jslock.c:ClaimScope) when
     * we're called from the GC.  Only the GC should call js_FinalizeObject,
     * and no other threads run JS (and possibly racing to update obj->slots)
     * while the GC is running.
     */
    LOCKED_OBJ_GET_CLASS(obj)->finalize(cx, obj);

    /* Drop map and free slots. */
    js_DropObjectMap(cx, map, obj);
    obj->map = NULL;
    JS_free(cx, obj->slots - 1);
    obj->slots = NULL;
}

/* XXXbe if one adds props, deletes earlier props, adds more, the last added
         won't recycle the deleted props' slots. */
JSBool
js_AllocSlot(JSContext *cx, JSObject *obj, uint32 *slotp)
{
    JSObjectMap *map;
    uint32 nslots, i;
    size_t nbytes;
    jsval *newslots;

    map = obj->map;
    JS_ASSERT(!MAP_IS_NATIVE(map) || ((JSScope *)map)->object == obj);
    nslots = map->nslots;
    if (map->freeslot >= nslots) {
        nslots = map->freeslot;
        JS_ASSERT(nslots >= JS_INITIAL_NSLOTS);
        nslots += (nslots + 1) / 2;

        nbytes = (nslots + 1) * sizeof(jsval);
#if defined _MSC_VER && _MSC_VER <= 800
        if (nbytes > 60000U) {
            JS_ReportOutOfMemory(cx);
            return JS_FALSE;
        }
#endif

        newslots = (jsval *) JS_realloc(cx, obj->slots - 1, nbytes);
        if (!newslots)
            return JS_FALSE;
        for (i = 1 + newslots[0]; i <= nslots; i++)
            newslots[i] = JSVAL_VOID;
        newslots[0] = map->nslots = nslots;
        obj->slots = newslots + 1;
    }

#ifdef TOO_MUCH_GC
    obj->slots[map->freeslot] = JSVAL_VOID;
#endif
    *slotp = map->freeslot++;
    return JS_TRUE;
}

void
js_FreeSlot(JSContext *cx, JSObject *obj, uint32 slot)
{
    JSObjectMap *map;
    uint32 nslots;
    size_t nbytes;
    jsval *newslots;

    OBJ_CHECK_SLOT(obj, slot);
    obj->slots[slot] = JSVAL_VOID;
    map = obj->map;
    JS_ASSERT(!MAP_IS_NATIVE(map) || ((JSScope *)map)->object == obj);
    if (map->freeslot == slot + 1)
        map->freeslot = slot;
    nslots = map->nslots;
    if (nslots > JS_INITIAL_NSLOTS && map->freeslot < nslots / 2) {
        nslots = map->freeslot;
        nslots += nslots / 2;
        if (nslots < JS_INITIAL_NSLOTS)
            nslots = JS_INITIAL_NSLOTS;
        nbytes = (nslots + 1) * sizeof(jsval);
        newslots = (jsval *) JS_realloc(cx, obj->slots - 1, nbytes);
        if (!newslots)
            return;
        newslots[0] = map->nslots = nslots;
        obj->slots = newslots + 1;
    }
}

#if JS_BUG_EMPTY_INDEX_ZERO
#define CHECK_FOR_EMPTY_INDEX(id)                                             \
    JS_BEGIN_MACRO                                                            \
        if (JSSTRING_LENGTH(_str) == 0)                                       \
            id = JSVAL_ZERO;                                                  \
    JS_END_MACRO
#else
#define CHECK_FOR_EMPTY_INDEX(id) /* nothing */
#endif

/* JSVAL_INT_MAX as a string */
#define JSVAL_INT_MAX_STRING "1073741823"

#define CHECK_FOR_FUNNY_INDEX(id)                                             \
    JS_BEGIN_MACRO                                                            \
        if (!JSVAL_IS_INT(id)) {