devtools/shared/heapsnapshot/tests/gtest/DoesntCrossCompartmentBoundaries.cpp
author Jan de Mooij <jdemooij@mozilla.com>
Sat, 28 Jul 2018 12:12:26 +0200
changeset 428852 1494e906ad52413008a722bf5e9ab533d1821f57
parent 422428 142288837f11e2863cf7eae9bd08b6f8733d21fd
child 429854 f5545b566fd7fddf676fde944562c6986ca0cba5
permissions -rw-r--r--
Bug 1478955 part 1 - Rename JSAutoRealm to JSAutoRealmAllowCCW. r=luke

/* -*-  Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2; -*- */
/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at http://mozilla.org/MPL/2.0/. */

// Test that heap snapshots walk the compartment boundaries correctly.

#include "DevTools.h"

DEF_TEST(DoesntCrossCompartmentBoundaries, {
    // Create a new global to get a new compartment.
    JS::RealmOptions options;
    JS::RootedObject newGlobal(cx, JS_NewGlobalObject(cx,
                                                      getGlobalClass(),
                                                      nullptr,
                                                      JS::FireOnNewGlobalHook,
                                                      options));
    ASSERT_TRUE(newGlobal);
    JS::Compartment* newCompartment = nullptr;
    {
      JSAutoRealmAllowCCW ar(cx, newGlobal);
      ASSERT_TRUE(JS::InitRealmStandardClasses(cx));
      newCompartment = js::GetContextCompartment(cx);
    }
    ASSERT_TRUE(newCompartment);
    ASSERT_NE(newCompartment, compartment);

    // Our set of target compartments is only the pre-existing compartment and
    // does not include the new compartment.
    JS::CompartmentSet targetCompartments;
    ASSERT_TRUE(targetCompartments.init());
    ASSERT_TRUE(targetCompartments.put(compartment));

    FakeNode nodeA;
    FakeNode nodeB;
    FakeNode nodeC;

    nodeA.compartment = compartment;
    nodeB.compartment = nullptr;
    nodeC.compartment = newCompartment;

    AddEdge(nodeA, nodeB);
    AddEdge(nodeB, nodeC);

    ::testing::NiceMock<MockWriter> writer;

    // Should serialize nodeA, because it is in our target compartments.
    ExpectWriteNode(writer, nodeA);

    // Should serialize nodeB, because it doesn't belong to a compartment and is
    // therefore assumed to be shared.
    ExpectWriteNode(writer, nodeB);

    // But we shouldn't ever serialize nodeC.

    JS::AutoCheckCannotGC noGC(cx);

    ASSERT_TRUE(WriteHeapGraph(cx,
                               JS::ubi::Node(&nodeA),
                               writer,
                               /* wantNames = */ false,
                               &targetCompartments,
                               noGC));
  });