js/src/vm/Exception.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
   2  * vim: set ts=8 sts=2 et sw=2 tw=80:
   3  * This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6
   7 #include "js/Exception.h"
   8
   9 #include "js/Context.h"  // js::AssertHeapIsIdle
  10 #include "vm/JSContext.h"
  11 #include "vm/SavedFrame.h"
  12
  13 using namespace js;
  14
  15 bool JS::StealPendingExceptionStack(JSContext* cx,
  16                                     JS::ExceptionStack* exceptionStack) {
  17   if (!GetPendingExceptionStack(cx, exceptionStack)) {
  18     return false;
  19   }
  20
  21   // "Steal" exception by clearing it.
  22   cx->clearPendingException();
  23   return true;
  24 }
  25
  26 bool JS::GetPendingExceptionStack(JSContext* cx,
  27                                   JS::ExceptionStack* exceptionStack) {
  28   AssertHeapIsIdle();
  29   CHECK_THREAD(cx);
  30
  31   MOZ_ASSERT(exceptionStack);
  32   MOZ_ASSERT(cx->isExceptionPending());
  33
  34   RootedValue exception(cx);
  35   if (!cx->getPendingException(&exception)) {
  36     return false;
  37   }
  38
  39   RootedObject stack(cx, cx->getPendingExceptionStack());
  40   exceptionStack->init(exception, stack);
  41   return true;
  42 }
  43
  44 void JS::SetPendingExceptionStack(JSContext* cx,
  45                                   const JS::ExceptionStack& exceptionStack) {
  46   AssertHeapIsIdle();
  47   CHECK_THREAD(cx);
  48
  49   // We don't check the compartments of `exception` and `stack` here,
  50   // because we're not doing anything with them other than storing
  51   // them, and stored exception values can be in an abitrary
  52   // compartment while stored stack values are always the unwrapped
  53   // object anyway.
  54
  55   Rooted<SavedFrame*> nstack(cx);
  56   if (exceptionStack.stack()) {
  57     nstack = &UncheckedUnwrap(exceptionStack.stack())->as<SavedFrame>();
  58   }
  59   cx->setPendingException(exceptionStack.exception(), nstack);
  60 }