js/src/jswrapper.cpp

   1 /* -*- Mode: C++; tab-width: 4; indent-tabs-mode: nil; c-basic-offset: 4 -*-
   2  * vim: set ts=4 sw=4 et tw=99:
   3  *
   4  * ***** BEGIN LICENSE BLOCK *****
   5  * Version: MPL 1.1/GPL 2.0/LGPL 2.1
   6  *
   7  * The contents of this file are subject to the Mozilla Public License Version
   8  * 1.1 (the "License"); you may not use this file except in compliance with
   9  * the License. You may obtain a copy of the License at
  10  * http://www.mozilla.org/MPL/
  11  *
  12  * Software distributed under the License is distributed on an "AS IS" basis,
  13  * WITHOUT WARRANTY OF ANY KIND, either express or implied. See the License
  14  * for the specific language governing rights and limitations under the
  15  * License.
  16  *
  17  * The Original Code is Mozilla SpiderMonkey JavaScript 1.9 code, released
  18  * May 28, 2008.
  19  *
  20  * The Initial Developer of the Original Code is
  21  *   Mozilla Foundation
  22  * Portions created by the Initial Developer are Copyright (C) 2010
  23  * the Initial Developer. All Rights Reserved.
  24  *
  25  * Contributor(s):
  26  *   Andreas Gal <gal@mozilla.com>
  27  *
  28  * Alternatively, the contents of this file may be used under the terms of
  29  * either of the GNU General Public License Version 2 or later (the "GPL"),
  30  * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
  31  * in which case the provisions of the GPL or the LGPL are applicable instead
  32  * of those above. If you wish to allow use of your version of this file only
  33  * under the terms of either the GPL or the LGPL, and not to allow others to
  34  * use your version of this file under the terms of the MPL, indicate your
  35  * decision by deleting the provisions above and replace them with the notice
  36  * and other provisions required by the GPL or the LGPL. If you do not delete
  37  * the provisions above, a recipient may use your version of this file under
  38  * the terms of any one of the MPL, the GPL or the LGPL.
  39  *
  40  * ***** END LICENSE BLOCK ***** */
  41
  42 #include "jsapi.h"
  43 #include "jscntxt.h"
  44 #include "jsiter.h"
  45 #include "jsnum.h"
  46 #include "jsregexp.h"
  47 #include "jswrapper.h"
  48 #include "methodjit/PolyIC.h"
  49 #include "methodjit/MonoIC.h"
  50 #ifdef JS_METHODJIT
  51 # include "assembler/jit/ExecutableAllocator.h"
  52 #endif
  53 #include "jscompartment.h"
  54
  55 #include "jsobjinlines.h"
  56
  57 using namespace js;
  58 using namespace js::gc;
  59
  60 static int sWrapperFamily;
  61
  62 void *
  63 JSWrapper::getWrapperFamily()
  64 {
  65     return &sWrapperFamily;
  66 }
  67
  68 bool
  69 JSObject::isWrapper() const
  70 {
  71     return isProxy() && getProxyHandler()->family() == &sWrapperFamily;
  72 }
  73
  74 JSObject *
  75 JSObject::unwrap(uintN *flagsp)
  76 {
  77     JSObject *wrapped = this;
  78     uintN flags = 0;
  79     while (wrapped->isWrapper()) {
  80         flags |= static_cast<JSWrapper *>(wrapped->getProxyHandler())->flags();
  81         wrapped = wrapped->getProxyPrivate().toObjectOrNull();
  82         if (wrapped->getClass()->ext.innerObject)
  83             break;
  84     }
  85     if (flagsp)
  86         *flagsp = flags;
  87     return wrapped;
  88 }
  89
  90 JSWrapper::JSWrapper(uintN flags) : JSProxyHandler(&sWrapperFamily), mFlags(flags)
  91 {
  92 }
  93
  94 JSWrapper::~JSWrapper()
  95 {
  96 }
  97
  98 #define CHECKED(op, act)                                                     \
  99     JS_BEGIN_MACRO                                                           \
 100         bool status;                                                         \
 101         if (!enter(cx, wrapper, id, act, &status))                           \
 102             return status;                                                   \
 103         bool ok = (op);                                                      \
 104         leave(cx, wrapper);                                                  \
 105         return ok;                                                           \
 106     JS_END_MACRO
 107
 108 #define SET(action) CHECKED(action, SET)
 109 #define GET(action) CHECKED(action, GET)
 110
 111 bool
 112 JSWrapper::getPropertyDescriptor(JSContext *cx, JSObject *wrapper, jsid id,
 113                                  bool set, PropertyDescriptor *desc)
 114 {
 115     desc->obj= NULL; // default result if we refuse to perform this action
 116     CHECKED(JS_GetPropertyDescriptorById(cx, wrappedObject(wrapper), id, JSRESOLVE_QUALIFIED,
 117                                          Jsvalify(desc)), set ? SET : GET);
 118 }
 119
 120 static bool
 121 GetOwnPropertyDescriptor(JSContext *cx, JSObject *obj, jsid id, uintN flags, JSPropertyDescriptor *desc)
 122 {
 123     if (!JS_GetPropertyDescriptorById(cx, obj, id, flags, desc))
 124         return false;
 125     if (desc->obj != obj)
 126         desc->obj = NULL;
 127     return true;
 128 }
 129
 130 bool
 131 JSWrapper::getOwnPropertyDescriptor(JSContext *cx, JSObject *wrapper, jsid id, bool set,
 132                                     PropertyDescriptor *desc)
 133 {
 134     desc->obj= NULL; // default result if we refuse to perform this action
 135     CHECKED(GetOwnPropertyDescriptor(cx, wrappedObject(wrapper), id, JSRESOLVE_QUALIFIED,
 136                                      Jsvalify(desc)), set ? SET : GET);
 137 }
 138
 139 bool
 140 JSWrapper::defineProperty(JSContext *cx, JSObject *wrapper, jsid id,
 141                           PropertyDescriptor *desc)
 142 {
 143     SET(JS_DefinePropertyById(cx, wrappedObject(wrapper), id, Jsvalify(desc->value),
 144                               Jsvalify(desc->getter), Jsvalify(desc->setter), desc->attrs));
 145 }
 146
 147 bool
 148 JSWrapper::getOwnPropertyNames(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 149 {
 150     // if we refuse to perform this action, props remains empty
 151     jsid id = JSID_VOID;
 152     GET(GetPropertyNames(cx, wrappedObject(wrapper), JSITER_OWNONLY | JSITER_HIDDEN, &props));
 153 }
 154
 155 static bool
 156 ValueToBoolean(Value *vp, bool *bp)
 157 {
 158     *bp = js_ValueToBoolean(*vp);
 159     return true;
 160 }
 161
 162 bool
 163 JSWrapper::delete_(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 164 {
 165     *bp = true; // default result if we refuse to perform this action
 166     Value v;
 167     SET(JS_DeletePropertyById2(cx, wrappedObject(wrapper), id, Jsvalify(&v)) &&
 168         ValueToBoolean(&v, bp));
 169 }
 170
 171 bool
 172 JSWrapper::enumerate(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 173 {
 174     // if we refuse to perform this action, props remains empty
 175     static jsid id = JSID_VOID;
 176     GET(GetPropertyNames(cx, wrappedObject(wrapper), 0, &props));
 177 }
 178
 179 bool
 180 JSWrapper::fix(JSContext *cx, JSObject *wrapper, Value *vp)
 181 {
 182     vp->setUndefined();
 183     return true;
 184 }
 185
 186 static bool
 187 Cond(JSBool b, bool *bp)
 188 {
 189     *bp = !!b;
 190     return true;
 191 }
 192
 193 bool
 194 JSWrapper::has(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 195 {
 196     *bp = false; // default result if we refuse to perform this action
 197     JSBool found;
 198     GET(JS_HasPropertyById(cx, wrappedObject(wrapper), id, &found) &&
 199         Cond(found, bp));
 200 }
 201
 202 bool
 203 JSWrapper::hasOwn(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 204 {
 205     *bp = false; // default result if we refuse to perform this action
 206     PropertyDescriptor desc;
 207     JSObject *wobj = wrappedObject(wrapper);
 208     GET(JS_GetPropertyDescriptorById(cx, wobj, id, JSRESOLVE_QUALIFIED, Jsvalify(&desc)) &&
 209         Cond(desc.obj == wobj, bp));
 210 }
 211
 212 bool
 213 JSWrapper::get(JSContext *cx, JSObject *wrapper, JSObject *receiver, jsid id, Value *vp)
 214 {
 215     vp->setUndefined(); // default result if we refuse to perform this action
 216     GET(wrappedObject(wrapper)->getProperty(cx, receiver, id, vp));
 217 }
 218
 219 bool
 220 JSWrapper::set(JSContext *cx, JSObject *wrapper, JSObject *receiver, jsid id, bool strict,
 221                Value *vp)
 222 {
 223     // FIXME (bug 596351): Need deal with strict mode.
 224     SET(wrappedObject(wrapper)->setProperty(cx, id, vp, false));
 225 }
 226
 227 bool
 228 JSWrapper::keys(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 229 {
 230     // if we refuse to perform this action, props remains empty
 231     const jsid id = JSID_VOID;
 232     GET(GetPropertyNames(cx, wrappedObject(wrapper), JSITER_OWNONLY, &props));
 233 }
 234
 235 bool
 236 JSWrapper::iterate(JSContext *cx, JSObject *wrapper, uintN flags, Value *vp)
 237 {
 238     vp->setUndefined(); // default result if we refuse to perform this action
 239     const jsid id = JSID_VOID;
 240     GET(GetIterator(cx, wrappedObject(wrapper), flags, vp));
 241 }
 242
 243 bool
 244 JSWrapper::call(JSContext *cx, JSObject *wrapper, uintN argc, Value *vp)
 245 {
 246     vp->setUndefined(); // default result if we refuse to perform this action
 247     const jsid id = JSID_VOID;
 248     CHECKED(JSProxyHandler::call(cx, wrapper, argc, vp), CALL);
 249 }
 250
 251 bool
 252 JSWrapper::construct(JSContext *cx, JSObject *wrapper, uintN argc, Value *argv, Value *vp)
 253 {
 254     vp->setUndefined(); // default result if we refuse to perform this action
 255     const jsid id = JSID_VOID;
 256     GET(JSProxyHandler::construct(cx, wrapper, argc, argv, vp));
 257 }
 258
 259 bool
 260 JSWrapper::hasInstance(JSContext *cx, JSObject *wrapper, const Value *vp, bool *bp)
 261 {
 262     *bp = true; // default result if we refuse to perform this action
 263     const jsid id = JSID_VOID;
 264     JSBool b;
 265     GET(JS_HasInstance(cx, wrappedObject(wrapper), Jsvalify(*vp), &b) && Cond(b, bp));
 266 }
 267
 268 JSType
 269 JSWrapper::typeOf(JSContext *cx, JSObject *wrapper)
 270 {
 271     return TypeOfValue(cx, ObjectValue(*wrappedObject(wrapper)));
 272 }
 273
 274 JSString *
 275 JSWrapper::obj_toString(JSContext *cx, JSObject *wrapper)
 276 {
 277     bool status;
 278     if (!enter(cx, wrapper, JSID_VOID, GET, &status)) {
 279         if (status) {
 280             // Perform some default behavior that doesn't leak any information.
 281             return JS_NewStringCopyZ(cx, "[object Object]");
 282         }
 283         return NULL;
 284     }
 285     JSString *str = obj_toStringHelper(cx, wrappedObject(wrapper));
 286     leave(cx, wrapper);
 287     return str;
 288 }
 289
 290 JSString *
 291 JSWrapper::fun_toString(JSContext *cx, JSObject *wrapper, uintN indent)
 292 {
 293     bool status;
 294     if (!enter(cx, wrapper, JSID_VOID, GET, &status)) {
 295         if (status) {
 296             // Perform some default behavior that doesn't leak any information.
 297             if (wrapper->isCallable())
 298                 return JS_NewStringCopyZ(cx, "function () {\n    [native code]\n}");
 299             js::Value v = ObjectValue(*wrapper);
 300             js_ReportIsNotFunction(cx, &v, 0);
 301             return NULL;
 302         }
 303         return NULL;
 304     }
 305     JSString *str = JSProxyHandler::fun_toString(cx, wrapper, indent);
 306     leave(cx, wrapper);
 307     return str;
 308 }
 309
 310 void
 311 JSWrapper::trace(JSTracer *trc, JSObject *wrapper)
 312 {
 313     MarkObject(trc, *wrappedObject(wrapper), "wrappedObject");
 314 }
 315
 316 bool
 317 JSWrapper::enter(JSContext *cx, JSObject *wrapper, jsid id, Action act, bool *bp)
 318 {
 319     *bp = true;
 320     return true;
 321 }
 322
 323 void
 324 JSWrapper::leave(JSContext *cx, JSObject *wrapper)
 325 {
 326 }
 327
 328 JSWrapper JSWrapper::singleton((uintN)0);
 329
 330 JSObject *
 331 JSWrapper::New(JSContext *cx, JSObject *obj, JSObject *proto, JSObject *parent,
 332                JSWrapper *handler)
 333 {
 334     JS_ASSERT(parent);
 335     if (obj->isXML()) {
 336         JS_ReportErrorNumber(cx, js_GetErrorMessage, NULL, JSMSG_CANT_WRAP_XML_OBJECT);
 337         return NULL;
 338     }
 339     return NewProxyObject(cx, handler, ObjectValue(*obj), proto, parent,
 340                           obj->isCallable() ? obj : NULL, NULL);
 341 }
 342
 343 /* Compartments. */
 344
 345 namespace js {
 346
 347 extern JSObject *
 348 TransparentObjectWrapper(JSContext *cx, JSObject *obj, JSObject *wrappedProto, JSObject *parent,
 349                          uintN flags)
 350 {
 351     // Allow wrapping outer window proxies.
 352     JS_ASSERT(!obj->isWrapper() || obj->getClass()->ext.innerObject);
 353     return JSWrapper::New(cx, obj, wrappedProto, parent, &JSCrossCompartmentWrapper::singleton);
 354 }
 355
 356 }
 357
 358 AutoCompartment::AutoCompartment(JSContext *cx, JSObject *target)
 359     : context(cx),
 360       origin(cx->compartment),
 361       target(target),
 362       destination(target->getCompartment()),
 363       input(cx),
 364       entered(false)
 365 {
 366 }
 367
 368 AutoCompartment::~AutoCompartment()
 369 {
 370     if (entered)
 371         leave();
 372 }
 373
 374 bool
 375 AutoCompartment::enter()
 376 {
 377     JS_ASSERT(!entered);
 378     if (origin != destination) {
 379         LeaveTrace(context);
 380
 381         context->compartment = destination;
 382         JSObject *scopeChain = target->getGlobal();
 383         JS_ASSERT(scopeChain->isNative());
 384
 385         frame.construct();
 386         if (!context->stack().pushDummyFrame(context, *scopeChain, &frame.ref())) {
 387             context->compartment = origin;
 388             return false;
 389         }
 390
 391         if (context->isExceptionPending())
 392             context->wrapPendingException();
 393     }
 394     entered = true;
 395     return true;
 396 }
 397
 398 void
 399 AutoCompartment::leave()
 400 {
 401     JS_ASSERT(entered);
 402     if (origin != destination) {
 403         frame.destroy();
 404         context->resetCompartment();
 405     }
 406     entered = false;
 407 }
 408
 409 /* Cross compartment wrappers. */
 410
 411 JSCrossCompartmentWrapper::JSCrossCompartmentWrapper(uintN flags)
 412   : JSWrapper(CROSS_COMPARTMENT | flags)
 413 {
 414 }
 415
 416 JSCrossCompartmentWrapper::~JSCrossCompartmentWrapper()
 417 {
 418 }
 419
 420 #define PIERCE(cx, wrapper, mode, pre, op, post)            \
 421     JS_BEGIN_MACRO                                          \
 422         AutoCompartment call(cx, wrappedObject(wrapper));   \
 423         if (!call.enter())                                  \
 424             return false;                                   \
 425         bool ok = (pre) && (op);                            \
 426         call.leave();                                       \
 427         return ok && (post);                                \
 428     JS_END_MACRO
 429
 430 #define NOTHING (true)
 431
 432 bool
 433 JSCrossCompartmentWrapper::getPropertyDescriptor(JSContext *cx, JSObject *wrapper, jsid id,
 434                                                  bool set, PropertyDescriptor *desc)
 435 {
 436     PIERCE(cx, wrapper, set ? SET : GET,
 437            call.destination->wrapId(cx, &id),
 438            JSWrapper::getPropertyDescriptor(cx, wrapper, id, set, desc),
 439            call.origin->wrap(cx, desc));
 440 }
 441
 442 bool
 443 JSCrossCompartmentWrapper::getOwnPropertyDescriptor(JSContext *cx, JSObject *wrapper, jsid id,
 444                                                     bool set, PropertyDescriptor *desc)
 445 {
 446     PIERCE(cx, wrapper, set ? SET : GET,
 447            call.destination->wrapId(cx, &id),
 448            JSWrapper::getOwnPropertyDescriptor(cx, wrapper, id, set, desc),
 449            call.origin->wrap(cx, desc));
 450 }
 451
 452 bool
 453 JSCrossCompartmentWrapper::defineProperty(JSContext *cx, JSObject *wrapper, jsid id, PropertyDescriptor *desc)
 454 {
 455     AutoPropertyDescriptorRooter desc2(cx, desc);
 456     PIERCE(cx, wrapper, SET,
 457            call.destination->wrapId(cx, &id) && call.destination->wrap(cx, &desc2),
 458            JSWrapper::defineProperty(cx, wrapper, id, &desc2),
 459            NOTHING);
 460 }
 461
 462 bool
 463 JSCrossCompartmentWrapper::getOwnPropertyNames(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 464 {
 465     PIERCE(cx, wrapper, GET,
 466            NOTHING,
 467            JSWrapper::getOwnPropertyNames(cx, wrapper, props),
 468            call.origin->wrap(cx, props));
 469 }
 470
 471 bool
 472 JSCrossCompartmentWrapper::delete_(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 473 {
 474     PIERCE(cx, wrapper, SET,
 475            call.destination->wrapId(cx, &id),
 476            JSWrapper::delete_(cx, wrapper, id, bp),
 477            NOTHING);
 478 }
 479
 480 bool
 481 JSCrossCompartmentWrapper::enumerate(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 482 {
 483     PIERCE(cx, wrapper, GET,
 484            NOTHING,
 485            JSWrapper::enumerate(cx, wrapper, props),
 486            call.origin->wrap(cx, props));
 487 }
 488
 489 bool
 490 JSCrossCompartmentWrapper::has(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 491 {
 492     PIERCE(cx, wrapper, GET,
 493            call.destination->wrapId(cx, &id),
 494            JSWrapper::has(cx, wrapper, id, bp),
 495            NOTHING);
 496 }
 497
 498 bool
 499 JSCrossCompartmentWrapper::hasOwn(JSContext *cx, JSObject *wrapper, jsid id, bool *bp)
 500 {
 501     PIERCE(cx, wrapper, GET,
 502            call.destination->wrapId(cx, &id),
 503            JSWrapper::hasOwn(cx, wrapper, id, bp),
 504            NOTHING);
 505 }
 506
 507 bool
 508 JSCrossCompartmentWrapper::get(JSContext *cx, JSObject *wrapper, JSObject *receiver, jsid id, Value *vp)
 509 {
 510     PIERCE(cx, wrapper, GET,
 511            call.destination->wrap(cx, &receiver) && call.destination->wrapId(cx, &id),
 512            JSWrapper::get(cx, wrapper, receiver, id, vp),
 513            call.origin->wrap(cx, vp));
 514 }
 515
 516 bool
 517 JSCrossCompartmentWrapper::set(JSContext *cx, JSObject *wrapper, JSObject *receiver, jsid id,
 518                                bool strict, Value *vp)
 519 {
 520     AutoValueRooter tvr(cx, *vp);
 521     PIERCE(cx, wrapper, SET,
 522            call.destination->wrap(cx, &receiver) &&
 523            call.destination->wrapId(cx, &id) &&
 524            call.destination->wrap(cx, tvr.addr()),
 525            JSWrapper::set(cx, wrapper, receiver, id, strict, tvr.addr()),
 526            NOTHING);
 527 }
 528
 529 bool
 530 JSCrossCompartmentWrapper::keys(JSContext *cx, JSObject *wrapper, AutoIdVector &props)
 531 {
 532     PIERCE(cx, wrapper, GET,
 533            NOTHING,
 534            JSWrapper::keys(cx, wrapper, props),
 535            call.origin->wrap(cx, props));
 536 }
 537
 538 /*
 539  * We can reify non-escaping iterator objects instead of having to wrap them. This
 540  * allows fast iteration over objects across a compartment boundary.
 541  */
 542 static bool
 543 CanReify(Value *vp)
 544 {
 545     JSObject *obj;
 546     return vp->isObject() &&
 547            (obj = &vp->toObject())->getClass() == &js_IteratorClass &&
 548            (obj->getNativeIterator()->flags & JSITER_ENUMERATE);
 549 }
 550
 551 struct AutoCloseIterator
 552 {
 553     AutoCloseIterator(JSContext *cx, JSObject *obj) : cx(cx), obj(obj) {}
 554
 555     ~AutoCloseIterator() { if (obj) js_CloseIterator(cx, obj); }
 556
 557     void clear() { obj = NULL; }
 558
 559   private:
 560     JSContext *cx;
 561     JSObject *obj;
 562 };
 563
 564 static bool
 565 Reify(JSContext *cx, JSCompartment *origin, Value *vp)
 566 {
 567     JSObject *iterObj = &vp->toObject();
 568     NativeIterator *ni = iterObj->getNativeIterator();
 569
 570     AutoCloseIterator close(cx, iterObj);
 571
 572     /* Wrap the iteratee. */
 573     JSObject *obj = ni->obj;
 574     if (!origin->wrap(cx, &obj))
 575         return false;
 576
 577     /*
 578      * Wrap the elements in the iterator's snapshot.
 579      * N.B. the order of closing/creating iterators is important due to the
 580      * implicit cx->enumerators state.
 581      */
 582     size_t length = ni->numKeys();
 583     bool isKeyIter = ni->isKeyIter();
 584     AutoIdVector keys(cx);
 585     if (length > 0) {
 586         if (!keys.resize(length))
 587             return false;
 588         for (size_t i = 0; i < length; ++i) {
 589             keys[i] = ni->begin()[i];
 590             if (!origin->wrapId(cx, &keys[i]))
 591                 return false;
 592         }
 593     }
 594
 595     close.clear();
 596     if (!js_CloseIterator(cx, iterObj))
 597         return false;
 598
 599     if (isKeyIter)
 600         return VectorToKeyIterator(cx, obj, ni->flags, keys, vp);
 601     return VectorToValueIterator(cx, obj, ni->flags, keys, vp);
 602 }
 603
 604 bool
 605 JSCrossCompartmentWrapper::iterate(JSContext *cx, JSObject *wrapper, uintN flags, Value *vp)
 606 {
 607     PIERCE(cx, wrapper, GET,
 608            NOTHING,
 609            JSWrapper::iterate(cx, wrapper, flags, vp),
 610            CanReify(vp) ? Reify(cx, call.origin, vp) : call.origin->wrap(cx, vp));
 611 }
 612
 613 bool
 614 JSCrossCompartmentWrapper::call(JSContext *cx, JSObject *wrapper, uintN argc, Value *vp)
 615 {
 616     AutoCompartment call(cx, wrappedObject(wrapper));
 617     if (!call.enter())
 618         return false;
 619
 620     vp[0] = ObjectValue(*call.target);
 621     if (!call.destination->wrap(cx, &vp[1]))
 622         return false;
 623     Value *argv = JS_ARGV(cx, vp);
 624     for (size_t n = 0; n < argc; ++n) {
 625         if (!call.destination->wrap(cx, &argv[n]))
 626             return false;
 627     }
 628     if (!JSWrapper::call(cx, wrapper, argc, vp))
 629         return false;
 630
 631     call.leave();
 632     return call.origin->wrap(cx, vp);
 633 }
 634
 635 bool
 636 JSCrossCompartmentWrapper::construct(JSContext *cx, JSObject *wrapper, uintN argc, Value *argv,
 637                                      Value *rval)
 638 {
 639     AutoCompartment call(cx, wrappedObject(wrapper));
 640     if (!call.enter())
 641         return false;
 642
 643     for (size_t n = 0; n < argc; ++n) {
 644         if (!call.destination->wrap(cx, &argv[n]))
 645             return false;
 646     }
 647     if (!JSWrapper::construct(cx, wrapper, argc, argv, rval))
 648         return false;
 649
 650     call.leave();
 651     return call.origin->wrap(cx, rval);
 652 }
 653
 654 bool
 655 JSCrossCompartmentWrapper::hasInstance(JSContext *cx, JSObject *wrapper, const Value *vp, bool *bp)
 656 {
 657     AutoCompartment call(cx, wrappedObject(wrapper));
 658     if (!call.enter())
 659         return false;
 660
 661     Value v = *vp;
 662     if (!call.destination->wrap(cx, &v))
 663         return false;
 664     return JSWrapper::hasInstance(cx, wrapper, &v, bp);
 665 }
 666
 667 JSString *
 668 JSCrossCompartmentWrapper::obj_toString(JSContext *cx, JSObject *wrapper)
 669 {
 670     AutoCompartment call(cx, wrappedObject(wrapper));
 671     if (!call.enter())
 672         return NULL;
 673
 674     JSString *str = JSWrapper::obj_toString(cx, wrapper);
 675     if (!str)
 676         return NULL;
 677
 678     call.leave();
 679     if (!call.origin->wrap(cx, &str))
 680         return NULL;
 681     return str;
 682 }
 683
 684 JSString *
 685 JSCrossCompartmentWrapper::fun_toString(JSContext *cx, JSObject *wrapper, uintN indent)
 686 {
 687     AutoCompartment call(cx, wrappedObject(wrapper));
 688     if (!call.enter())
 689         return NULL;
 690
 691     JSString *str = JSWrapper::fun_toString(cx, wrapper, indent);
 692     if (!str)
 693         return NULL;
 694
 695     call.leave();
 696     if (!call.origin->wrap(cx, &str))
 697         return NULL;
 698     return str;
 699 }
 700
 701 JSCrossCompartmentWrapper JSCrossCompartmentWrapper::singleton(0u);