jsfun.c

java script test programing source code

        /*
         * If we found the property in a different object, don't try sticking
         * it into wrong slots vector. This can occur because we have a mutable
         * __proto__ slot, and cloned function objects rely on their __proto__
         * to delegate to the object that contains the var and arg properties.
         */
        if (!prop || pobj != obj) {
            if (prop)
                OBJ_DROP_PROPERTY(cx, pobj, prop);
            continue;
        }
        cprop = (JSScopeProperty *)prop;
        LOCKED_OBJ_SET_SLOT(obj, cprop->slot, vec[(uint16) sprop->shortid]);
        OBJ_DROP_PROPERTY(cx, obj, prop);
    }

    return JS_TRUE;
}

static JSBool
call_resolve(JSContext *cx, JSObject *obj, jsval id, uintN flags,
             JSObject **objp)
{
    JSStackFrame *fp;
    JSObject *funobj;
    JSString *str;
    JSAtom *atom;
    JSObject *obj2;
    JSProperty *prop;
    JSScopeProperty *sprop;
    JSPropertyOp getter, setter;
    uintN attrs, slot, nslots, spflags;
    jsval *vp, value;
    intN shortid;

    fp = (JSStackFrame *) JS_GetPrivate(cx, obj);
    if (!fp)
        return JS_TRUE;
    JS_ASSERT(fp->fun);

    if (!JSVAL_IS_STRING(id))
        return JS_TRUE;

    funobj = fp->argv ? JSVAL_TO_OBJECT(fp->argv[-2]) : fp->fun->object;
    if (!funobj)
        return JS_TRUE;
    JS_ASSERT((JSFunction *) JS_GetPrivate(cx, funobj) == fp->fun);

    str = JSVAL_TO_STRING(id);
    atom = js_AtomizeString(cx, str, 0);
    if (!atom)
        return JS_FALSE;
    if (!js_LookupHiddenProperty(cx, funobj, ATOM_TO_JSID(atom), &obj2, &prop))
        return JS_FALSE;

    if (prop) {
        if (!OBJ_IS_NATIVE(obj2)) {
            OBJ_DROP_PROPERTY(cx, obj2, prop);
            return JS_TRUE;
        }

        sprop = (JSScopeProperty *) prop;
        getter = sprop->getter;
        attrs = sprop->attrs & ~JSPROP_SHARED;
        slot = (uintN) sprop->shortid;
        OBJ_DROP_PROPERTY(cx, obj2, prop);

        /* Ensure we found an arg or var property for the same function. */
        if ((sprop->flags & SPROP_IS_HIDDEN) &&
            (obj2 == funobj ||
             (JSFunction *) JS_GetPrivate(cx, obj2) == fp->fun)) {
            if (getter == js_GetArgument) {
                vp = fp->argv;
                nslots = JS_MAX(fp->argc, fp->fun->nargs);
                getter = setter = NULL;
            } else {
                JS_ASSERT(getter == js_GetLocalVariable);
                vp = fp->vars;
                nslots = fp->nvars;
                getter = js_GetCallVariable;
                setter = js_SetCallVariable;
            }
            if (slot < nslots) {
                value = vp[slot];
                spflags = SPROP_HAS_SHORTID;
                shortid = (intN) slot;
            } else {
                value = JSVAL_VOID;
                spflags = 0;
                shortid = 0;
            }
            if (!js_DefineNativeProperty(cx, obj, ATOM_TO_JSID(atom), value,
                                         getter, setter, attrs,
                                         spflags, shortid, NULL)) {
                return JS_FALSE;
            }
            *objp = obj;
        }
    }

    return JS_TRUE;
}

static JSBool
call_convert(JSContext *cx, JSObject *obj, JSType type, jsval *vp)
{
    JSStackFrame *fp;

    if (type == JSTYPE_FUNCTION) {
        fp = (JSStackFrame *) JS_GetPrivate(cx, obj);
        if (fp) {
            JS_ASSERT(fp->fun);
            *vp = fp->argv ? fp->argv[-2] : OBJECT_TO_JSVAL(fp->fun->object);
        }
    }
    return JS_TRUE;
}

JSClass js_CallClass = {
    js_Call_str,
    JSCLASS_HAS_PRIVATE | JSCLASS_NEW_RESOLVE | JSCLASS_IS_ANONYMOUS |
    JSCLASS_HAS_CACHED_PROTO(JSProto_Call),
    JS_PropertyStub,    JS_PropertyStub,
    call_getProperty,   call_setProperty,
    call_enumerate,     (JSResolveOp)call_resolve,
    call_convert,       JS_FinalizeStub,
    NULL,               NULL,
    NULL,               NULL,
    NULL,               NULL,
    args_or_call_mark,  NULL,
};

/*
 * ECMA-262 specifies that length is a property of function object instances,
 * but we can avoid that space cost by delegating to a prototype property that
 * is JSPROP_PERMANENT and JSPROP_SHARED.  Each fun_getProperty call computes
 * a fresh length value based on the arity of the individual function object's
 * private data.
 *
 * The extensions below other than length, i.e., the ones not in ECMA-262,
 * are neither JSPROP_READONLY nor JSPROP_SHARED, because for compatibility
 * with ECMA we must allow a delegating object to override them.
 */
#define LENGTH_PROP_ATTRS (JSPROP_READONLY|JSPROP_PERMANENT|JSPROP_SHARED)

static JSPropertySpec function_props[] = {
    {js_arguments_str, CALL_ARGUMENTS, JSPROP_PERMANENT,  0,0},
    {js_arity_str,     FUN_ARITY,      JSPROP_PERMANENT,  0,0},
    {js_caller_str,    FUN_CALLER,     JSPROP_PERMANENT,  0,0},
    {js_length_str,    ARGS_LENGTH,    LENGTH_PROP_ATTRS, 0,0},
    {js_name_str,      FUN_NAME,       JSPROP_PERMANENT,  0,0},
    {0,0,0,0,0}
};

static JSBool
fun_getProperty(JSContext *cx, JSObject *obj, jsval id, jsval *vp)
{
    jsint slot;
    JSFunction *fun;
    JSStackFrame *fp;

    if (!JSVAL_IS_INT(id))
        return JS_TRUE;
    slot = JSVAL_TO_INT(id);

    /*
     * Loop because getter and setter can be delegated from another class,
     * but loop only for ARGS_LENGTH because we must pretend that f.length
     * is in each function instance f, per ECMA-262, instead of only in the
     * Function.prototype object (we use JSPROP_PERMANENT with JSPROP_SHARED
     * to make it appear so).
     *
     * This code couples tightly to the attributes for the function_props[]
     * initializers above, and to js_SetProperty and js_HasOwnPropertyHelper.
     *
     * It's important to allow delegating objects, even though they inherit
     * this getter (fun_getProperty), to override arguments, arity, caller,
     * and name.  If we didn't return early for slot != ARGS_LENGTH, we would
     * clobber *vp with the native property value, instead of letting script
     * override that value in delegating objects.
     *
     * Note how that clobbering is what simulates JSPROP_READONLY for all of
     * the non-standard properties when the directly addressed object (obj)
     * is a function object (i.e., when this loop does not iterate).
     */
    while (!(fun = (JSFunction *)
                   JS_GetInstancePrivate(cx, obj, &js_FunctionClass, NULL))) {
        if (slot != ARGS_LENGTH)
            return JS_TRUE;
        obj = OBJ_GET_PROTO(cx, obj);
        if (!obj)
            return JS_TRUE;
    }

    /* Find fun's top-most activation record. */
    for (fp = cx->fp; fp && (fp->fun != fun || (fp->flags & JSFRAME_SPECIAL));
         fp = fp->down) {
        continue;
    }

    switch (slot) {
      case CALL_ARGUMENTS:
        /* Warn if strict about f.arguments or equivalent unqualified uses. */
        if (!JS_ReportErrorFlagsAndNumber(cx,
                                          JSREPORT_WARNING | JSREPORT_STRICT,
                                          js_GetErrorMessage, NULL,
                                          JSMSG_DEPRECATED_USAGE,
                                          js_arguments_str)) {
            return JS_FALSE;
        }
        if (fp) {
            if (!js_GetArgsValue(cx, fp, vp))
                return JS_FALSE;
        } else {
            *vp = JSVAL_NULL;
        }
        break;

      case ARGS_LENGTH:
      case FUN_ARITY:
            *vp = INT_TO_JSVAL((jsint)fun->nargs);
        break;

      case FUN_NAME:
        *vp = fun->atom
              ? ATOM_KEY(fun->atom)
              : STRING_TO_JSVAL(cx->runtime->emptyString);
        break;

      case FUN_CALLER:
        while (fp && (fp->flags & JSFRAME_SKIP_CALLER) && fp->down)
            fp = fp->down;
        if (fp && fp->down && fp->down->fun && fp->down->argv)
            *vp = fp->down->argv[-2];
        else
            *vp = JSVAL_NULL;
        if (!JSVAL_IS_PRIMITIVE(*vp) && cx->runtime->checkObjectAccess) {
            id = ATOM_KEY(cx->runtime->atomState.callerAtom);
            if (!cx->runtime->checkObjectAccess(cx, obj, id, JSACC_READ, vp))
                return JS_FALSE;
        }
        break;

      default:
        /* XXX fun[0] and fun.arguments[0] are equivalent. */
        if (fp && fp->fun && (uintN)slot < fp->fun->nargs)
            *vp = fp->argv[slot];
        break;
    }

    return JS_TRUE;
}

static JSBool
fun_enumerate(JSContext *cx, JSObject *obj)
{
    jsid prototypeId;
    JSObject *pobj;
    JSProperty *prop;

    prototypeId = ATOM_TO_JSID(cx->runtime->atomState.classPrototypeAtom);
    if (!OBJ_LOOKUP_PROPERTY(cx, obj, prototypeId, &pobj, &prop))
        return JS_FALSE;
    if (prop)
        OBJ_DROP_PROPERTY(cx, pobj, prop);
    return JS_TRUE;
}

static JSBool
fun_resolve(JSContext *cx, JSObject *obj, jsval id, uintN flags,
            JSObject **objp)
{
    JSFunction *fun;
    JSString *str;
    JSAtom *prototypeAtom;

    /*
     * No need to reflect fun.prototype in 'fun.prototype = ...' or in an
     * unqualified reference to prototype, which the emitter looks up as a
     * hidden atom when attempting to bind to a formal parameter or local
     * variable slot.
     */
    if (flags & (JSRESOLVE_ASSIGNING | JSRESOLVE_HIDDEN))
        return JS_TRUE;

    if (!JSVAL_IS_STRING(id))
        return JS_TRUE;

    /* No valid function object should lack private data, but check anyway. */
    fun = (JSFunction *)JS_GetInstancePrivate(cx, obj, &js_FunctionClass, NULL);
    if (!fun || !fun->object)
        return JS_TRUE;

    /*
     * Ok, check whether id is 'prototype' and bootstrap the function object's
     * prototype property.
     */
    str = JSVAL_TO_STRING(id);
    prototypeAtom = cx->runtime->atomState.classPrototypeAtom;
    if (str == ATOM_TO_STRING(prototypeAtom)) {
        JSObject *proto, *parentProto;
        jsval pval;

        proto = parentProto = NULL;
        if (fun->object != obj && fun->object) {
            /*
             * Clone of a function: make its prototype property value have the
             * same class as the clone-parent's prototype.
             */
            if (!OBJ_GET_PROPERTY(cx, fun->object, ATOM_TO_JSID(prototypeAtom),
                                  &pval)) {
                return JS_FALSE;
            }
            if (!JSVAL_IS_PRIMITIVE(pval)) {
                /*
                 * We are about to allocate a new object, so hack the newborn
                 * root until then to protect pval in case it is figuratively
                 * up in the air, with no strong refs protecting it.
                 */
                cx->weakRoots.newborn[GCX_OBJECT] = JSVAL_TO_GCTHING(pval);
                parentProto = JSVAL_TO_OBJECT(pval);
            }
        }

        /*
         * Beware of the wacky case of a user function named Object -- trying
         * to find a prototype for that will recur back here _ad perniciem_.
         */
        if (!parentProto && fun->atom == CLASS_ATOM(cx, Object))
            return JS_TRUE;

        /*
         * If resolving "prototype" in a clone, clone the parent's prototype.
         * Pass the constructor's (obj's) parent as the prototype parent, to
         * avoid defaulting to parentProto.constructor.__parent__.
         */
        proto = js_NewObject(cx, &js_ObjectClass, parentProto,
                             OBJ_GET_PARENT(cx, obj));
        if (!proto)
            return JS_FALSE;

        /*
         * ECMA (15.3.5.2) says that constructor.prototype is DontDelete for
         * user-defined functions, but DontEnum | ReadOnly | DontDelete for
         * native "system" constructors such as Object or Function.  So lazily
         * set the former here in fun_resolve, but eagerly define the latter
         * in JS_InitClass, with the right attributes.
         */
        if (!js_SetClassPrototype(cx, obj, proto,
                                  JSPROP_ENUMERATE | JSPROP_PERMANENT)) {
            cx->weakRoots.newborn[GCX_OBJECT] = NULL;
            return JS_FALSE;
        }
        *objp = obj;
    }

    return JS_TRUE;
}

static JSBool
fun_convert(JSContext *cx, JSObject *obj, JSType type, jsval *vp)
{
    switch (type) {
      case JSTYPE_FUNCTION:
        *vp = OBJECT_TO_JSVAL(obj);
        return JS_TRUE;
      default:
        return js_TryValueOf(cx, obj, type, vp);
    }
}

static void
fun_finalize(JSContext *cx, JSObject *obj)
{
    JSFunction *fun;
    JSScript *script;

    /* No valid function object should lack private data, but check anyway. */
    fun = (JSFunction *) JS_GetPrivate(cx, obj);
    if (!fun)
        return;
    if (fun->object == obj)
        fun->object = NULL;

    /* Null-check required since the parser sets interpreted very early. */
    if (FUN_INTERPRETED(fun) && fun->u.i.script &&
        js_IsAboutToBeFinalized(cx, fun))
    {
        script = fun->u.i.script;
        fun->u.i.script = NULL;
        js_DestroyScript(cx, script);
    }
}

#if JS_HAS_XDR

#include "jsxdrapi.h"

enum {
    JSXDR_FUNARG = 1,
    JSXDR_FUNVAR = 2,
    JSXDR_FUNCONST = 3
};

/* XXX store parent and proto, if defined */
static JSBool
fun_xdrObject(JSXDRState *xdr, JSObject **objp)
{
    JSContext *cx;
    JSFunction *fun;