libFuzzer for blink::MHTMLParser

third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp

Index: third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
diff --git a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
index 528f9e3e4f33eaace6bf030d62239db4ede5bb3d..e1e2ff4524fa56fe632476685a561095dc685202 100644
--- a/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
+++ b/third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp
@@ -30,11 +30,50 @@
 
 #include "platform/testing/TestingPlatformSupport.h"
 
+#include "base/command_line.h"
+#include "base/i18n/icu_util.h"
+#include "base/memory/discardable_memory_allocator.h"
+#include "base/metrics/statistics_recorder.h"
+#include "base/test/test_discardable_memory_allocator.h"
+#include "cc/blink/web_compositor_support_impl.h"
+#include "platform/EventTracer.h"
+#include "platform/HTTPNames.h"
+#include "platform/heap/Heap.h"
+#include "wtf/CryptographicallyRandomNumber.h"
+#include "wtf/CurrentTime.h"
 #include "wtf/PtrUtil.h"
+#include "wtf/WTF.h"
+#include "wtf/allocator/Partitions.h"
 #include <memory>
 
 namespace blink {
 
+namespace {
+
+double dummyCurrentTime()
+{
+    return 0.0;
+}
+
+class DummyThread final : public blink::WebThread {
+public:
+    bool isCurrentThread() const override { return true; }
+    blink::WebScheduler* scheduler() const override { return nullptr; }
+};
+
+class DummyPlatform final : public blink::Platform {
+public:
+    DummyPlatform() { }
+
+    blink::WebThread* currentThread() override
+    {
+        static DummyThread dummyThread;
+        return &dummyThread;
+    };
+};
+
+} // namespace
+
 TestingPlatformSupport::TestingPlatformSupport()
     : TestingPlatformSupport(TestingPlatformSupport::Config())
 {
@@ -193,4 +232,68 @@ TestingPlatformMockScheduler* TestingPlatformSupportWithMockScheduler::mockWebSc
     return m_mockWebThread->mockWebScheduler();
 }
 
+class ScopedUnittestsEnvironmentSetup::Impl {
+public:
+    Impl(int argc, char** argv, TestType);
+    ~Impl();
+private:
+    base::TestDiscardableMemoryAllocator m_discardableMemoryAllocator;
+    std::unique_ptr<DummyPlatform> m_platform;
+
+    cc_blink::WebCompositorSupportImpl m_compositorSupport;
+    TestingPlatformSupport::Config m_testingPlatformConfig;
+    std::unique_ptr<TestingPlatformSupport> m_testingPlatformSupport;
+};
+
+ScopedUnittestsEnvironmentSetup::Impl::Impl(
+    int argc, char** argv, TestType testType)
+{
+    base::CommandLine::Init(argc, argv);
+
+    // Make sure we don't initialize twice in case of unit tests -
+    // base::TestSuite::Initialize already calls base::i18n::InitializeICU.
+    if (testType == TestType::LibFuzzer)

[esprehn, 2016/08/04 04:37:53]

This doesn't feel right, why is the fuzzer running differently than unit tests?

[Łukasz Anforowicz, 2016/08/04 17:37:30]

Good catch / call.

It turns out that test code should call
base::i18n::AllowMultipleInitializeCallsForTesting (there are already a few
calls to this function in the code base).

The problem is that 1) base/test/test_suite.cc doesn't call this and 2)
base/test/test_suite.cc makes icu initialization conditional on a command line
switch.  To solve this, I've added InitializeICUForTesting which 1) checks the
cmdline switch + calls AllowMultipleInitializeCallsForTesting and 2) can be
reused from both base/test/test_suite.cc and from
third_party/WebKit/Source/platform/testing/TestingPlatformSupport.cpp

Done?  (pending review of base/test OWNERS)

+        base::i18n::InitializeICU();
+
+    base::DiscardableMemoryAllocator::SetInstance(&m_discardableMemoryAllocator);
+    base::StatisticsRecorder::Initialize();
+
+    m_platform = wrapUnique(new DummyPlatform);
+    Platform::setCurrentPlatformForTesting(m_platform.get());
+
+    WTF::Partitions::initialize(nullptr);
+    WTF::setTimeFunctionsForTesting(dummyCurrentTime);
+    WTF::initialize(nullptr);
+
+    m_testingPlatformConfig.compositorSupport = &m_compositorSupport;
+    m_testingPlatformSupport = wrapUnique(new TestingPlatformSupport(m_testingPlatformConfig));
+
+    ProcessHeap::init();
+    ThreadState::attachMainThread();
+    ThreadState::current()->registerTraceDOMWrappers(nullptr, nullptr, nullptr);
+    EventTracer::initialize();
+    HTTPNames::init();
+}
+
+ScopedUnittestsEnvironmentSetup::Impl::~Impl()
+{
+    blink::ThreadState::detachMainThread();
+    blink::ProcessHeap::shutdown();
+    m_testingPlatformSupport.reset();
+
+    WTF::shutdown();
+    WTF::Partitions::shutdown();
+}
+
+ScopedUnittestsEnvironmentSetup::ScopedUnittestsEnvironmentSetup(
+    int argc, char** argv, TestType testType)
+{
+    m_impl = wrapUnique(new Impl(argc, argv, testType));
+}
+
+ScopedUnittestsEnvironmentSetup::~ScopedUnittestsEnvironmentSetup()
+{
+    m_impl.reset();
+}
+
 } // namespace blink