Adding upstream version 115.8.0esr.upstream/115.8.0esr

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

7 files changed, 9222 insertions, 0 deletions

diff --git a/tools/profiler/tests/gtest/GeckoProfiler.cpp b/tools/profiler/tests/gtest/GeckoProfiler.cpp
new file mode 100644
index 0000000000..78456662f5
--- /dev/null
+++ b/tools/profiler/tests/gtest/GeckoProfiler.cpp
@@ -0,0 +1,5099 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* 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/. */
+
+// This file tests a lot of the profiler_*() functions in GeckoProfiler.h.
+// Most of the tests just check that nothing untoward (e.g. crashes, deadlocks)
+// happens when calling these functions. They don't do much inspection of
+// profiler internals.
+
+#include "mozilla/ProfilerThreadPlatformData.h"
+#include "mozilla/ProfilerThreadRegistration.h"
+#include "mozilla/ProfilerThreadRegistrationInfo.h"
+#include "mozilla/ProfilerThreadRegistry.h"
+#include "mozilla/ProfilerUtils.h"
+#include "mozilla/ProgressLogger.h"
+#include "mozilla/UniquePtrExtensions.h"
+
+#include "nsIThread.h"
+#include "nsThreadUtils.h"
+#include "prthread.h"
+
+#include "gtest/gtest.h"
+#include "mozilla/gtest/MozAssertions.h"
+
+#include <thread>
+
+#if defined(_MSC_VER) || defined(__MINGW32__)
+#  include <processthreadsapi.h>
+#  include <realtimeapiset.h>
+#elif defined(__APPLE__)
+#  include <mach/thread_act.h>
+#endif
+
+#ifdef XP_WIN
+#include "mozilla/WindowsVersion.h"
+#endif
+
+#ifdef MOZ_GECKO_PROFILER
+
+#  include "GeckoProfiler.h"
+#  include "mozilla/ProfilerMarkerTypes.h"
+#  include "mozilla/ProfilerMarkers.h"
+#  include "NetworkMarker.h"
+#  include "platform.h"
+#  include "ProfileBuffer.h"
+#  include "ProfilerControl.h"
+
+#  include "js/Initialization.h"
+#  include "js/Printf.h"
+#  include "jsapi.h"
+#  include "json/json.h"
+#  include "mozilla/Atomics.h"
+#  include "mozilla/BlocksRingBuffer.h"
+#  include "mozilla/DataMutex.h"
+#  include "mozilla/ProfileBufferEntrySerializationGeckoExtensions.h"
+#  include "mozilla/ProfileJSONWriter.h"
+#  include "mozilla/ScopeExit.h"
+#  include "mozilla/net/HttpBaseChannel.h"
+#  include "nsIChannelEventSink.h"
+#  include "nsIThread.h"
+#  include "nsThreadUtils.h"
+
+#  include <cstring>
+#  include <set>
+
+#endif  // MOZ_GECKO_PROFILER
+
+// Note: profiler_init() has already been called in XRE_main(), so we can't
+// test it here. Likewise for profiler_shutdown(), and AutoProfilerInit
+// (which is just an RAII wrapper for profiler_init() and profiler_shutdown()).
+
+using namespace mozilla;
+
+TEST(GeckoProfiler, ProfilerUtils)
+{
+  profiler_init_main_thread_id();
+
+  static_assert(std::is_same_v<decltype(profiler_current_process_id()),
+                               ProfilerProcessId>);
+  static_assert(
+      std::is_same_v<decltype(profiler_current_process_id()),
+                     decltype(baseprofiler::profiler_current_process_id())>);
+  ProfilerProcessId processId = profiler_current_process_id();
+  EXPECT_TRUE(processId.IsSpecified());
+  EXPECT_EQ(processId, baseprofiler::profiler_current_process_id());
+
+  static_assert(
+      std::is_same_v<decltype(profiler_current_thread_id()), ProfilerThreadId>);
+  static_assert(
+      std::is_same_v<decltype(profiler_current_thread_id()),
+                     decltype(baseprofiler::profiler_current_thread_id())>);
+  EXPECT_EQ(profiler_current_thread_id(),
+            baseprofiler::profiler_current_thread_id());
+
+  ProfilerThreadId mainTestThreadId = profiler_current_thread_id();
+  EXPECT_TRUE(mainTestThreadId.IsSpecified());
+
+  ProfilerThreadId mainThreadId = profiler_main_thread_id();
+  EXPECT_TRUE(mainThreadId.IsSpecified());
+
+  EXPECT_EQ(mainThreadId, mainTestThreadId)
+      << "Test should run on the main thread";
+  EXPECT_TRUE(profiler_is_main_thread());
+
+  std::thread testThread([&]() {
+    EXPECT_EQ(profiler_current_process_id(), processId);
+
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+    EXPECT_TRUE(testThreadId.IsSpecified());
+    EXPECT_NE(testThreadId, mainThreadId);
+    EXPECT_FALSE(profiler_is_main_thread());
+
+    EXPECT_EQ(baseprofiler::profiler_current_process_id(), processId);
+    EXPECT_EQ(baseprofiler::profiler_current_thread_id(), testThreadId);
+    EXPECT_EQ(baseprofiler::profiler_main_thread_id(), mainThreadId);
+    EXPECT_FALSE(baseprofiler::profiler_is_main_thread());
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistrationInfo)
+{
+  profiler_init_main_thread_id();
+
+  TimeStamp ts = TimeStamp::Now();
+  {
+    profiler::ThreadRegistrationInfo trInfo{
+        "name", ProfilerThreadId::FromNumber(123), false, ts};
+    EXPECT_STREQ(trInfo.Name(), "name");
+    EXPECT_NE(trInfo.Name(), "name")
+        << "ThreadRegistrationInfo should keep its own copy of the name";
+    EXPECT_EQ(trInfo.RegisterTime(), ts);
+    EXPECT_EQ(trInfo.ThreadId(), ProfilerThreadId::FromNumber(123));
+    EXPECT_EQ(trInfo.IsMainThread(), false);
+  }
+
+  // Make sure the next timestamp will be different from `ts`.
+  while (TimeStamp::Now() == ts) {
+  }
+
+  {
+    profiler::ThreadRegistrationInfo trInfoHere{"Here"};
+    EXPECT_STREQ(trInfoHere.Name(), "Here");
+    EXPECT_NE(trInfoHere.Name(), "Here")
+        << "ThreadRegistrationInfo should keep its own copy of the name";
+    TimeStamp baseRegistrationTime =
+        baseprofiler::detail::GetThreadRegistrationTime();
+    if (baseRegistrationTime) {
+      EXPECT_EQ(trInfoHere.RegisterTime(), baseRegistrationTime);
+    } else {
+      EXPECT_GT(trInfoHere.RegisterTime(), ts);
+    }
+    EXPECT_EQ(trInfoHere.ThreadId(), profiler_current_thread_id());
+    EXPECT_EQ(trInfoHere.ThreadId(), profiler_main_thread_id())
+        << "Gtests are assumed to run on the main thread";
+    EXPECT_EQ(trInfoHere.IsMainThread(), true)
+        << "Gtests are assumed to run on the main thread";
+  }
+
+  {
+    // Sub-thread test.
+    // These will receive sub-thread data (to test move at thread end).
+    TimeStamp tsThread;
+    ProfilerThreadId threadThreadId;
+    UniquePtr<profiler::ThreadRegistrationInfo> trInfoThreadPtr;
+
+    std::thread testThread([&]() {
+      profiler::ThreadRegistrationInfo trInfoThread{"Thread"};
+      EXPECT_STREQ(trInfoThread.Name(), "Thread");
+      EXPECT_NE(trInfoThread.Name(), "Thread")
+          << "ThreadRegistrationInfo should keep its own copy of the name";
+      EXPECT_GT(trInfoThread.RegisterTime(), ts);
+      EXPECT_EQ(trInfoThread.ThreadId(), profiler_current_thread_id());
+      EXPECT_NE(trInfoThread.ThreadId(), profiler_main_thread_id());
+      EXPECT_EQ(trInfoThread.IsMainThread(), false);
+
+      tsThread = trInfoThread.RegisterTime();
+      threadThreadId = trInfoThread.ThreadId();
+      trInfoThreadPtr =
+          MakeUnique<profiler::ThreadRegistrationInfo>(std::move(trInfoThread));
+    });
+    testThread.join();
+
+    ASSERT_NE(trInfoThreadPtr, nullptr);
+    EXPECT_STREQ(trInfoThreadPtr->Name(), "Thread");
+    EXPECT_EQ(trInfoThreadPtr->RegisterTime(), tsThread);
+    EXPECT_EQ(trInfoThreadPtr->ThreadId(), threadThreadId);
+    EXPECT_EQ(trInfoThreadPtr->IsMainThread(), false)
+        << "Gtests are assumed to run on the main thread";
+  }
+}
+
+static constexpr ThreadProfilingFeatures scEachAndAnyThreadProfilingFeatures[] =
+    {ThreadProfilingFeatures::CPUUtilization, ThreadProfilingFeatures::Sampling,
+     ThreadProfilingFeatures::Markers, ThreadProfilingFeatures::Any};
+
+TEST(GeckoProfiler, ThreadProfilingFeaturesType)
+{
+  ASSERT_EQ(static_cast<uint32_t>(ThreadProfilingFeatures::Any), 1u + 2u + 4u)
+      << "This test assumes that there are 3 binary choices 1+2+4; "
+         "Is this test up to date?";
+
+  EXPECT_EQ(Combine(ThreadProfilingFeatures::CPUUtilization,
+                    ThreadProfilingFeatures::Sampling,
+                    ThreadProfilingFeatures::Markers),
+            ThreadProfilingFeatures::Any);
+
+  constexpr ThreadProfilingFeatures allThreadProfilingFeatures[] = {
+      ThreadProfilingFeatures::NotProfiled,
+      ThreadProfilingFeatures::CPUUtilization,
+      ThreadProfilingFeatures::Sampling, ThreadProfilingFeatures::Markers,
+      ThreadProfilingFeatures::Any};
+
+  for (ThreadProfilingFeatures f1 : allThreadProfilingFeatures) {
+    // Combine and Intersect are commutative.
+    for (ThreadProfilingFeatures f2 : allThreadProfilingFeatures) {
+      EXPECT_EQ(Combine(f1, f2), Combine(f2, f1));
+      EXPECT_EQ(Intersect(f1, f2), Intersect(f2, f1));
+    }
+
+    // Combine works like OR.
+    EXPECT_EQ(Combine(f1, f1), f1);
+    EXPECT_EQ(Combine(f1, f1, f1), f1);
+
+    // 'OR NotProfiled' doesn't change anything.
+    EXPECT_EQ(Combine(f1, ThreadProfilingFeatures::NotProfiled), f1);
+
+    // 'OR Any' makes Any.
+    EXPECT_EQ(Combine(f1, ThreadProfilingFeatures::Any),
+              ThreadProfilingFeatures::Any);
+
+    // Intersect works like AND.
+    EXPECT_EQ(Intersect(f1, f1), f1);
+    EXPECT_EQ(Intersect(f1, f1, f1), f1);
+
+    // 'AND NotProfiled' erases anything.
+    EXPECT_EQ(Intersect(f1, ThreadProfilingFeatures::NotProfiled),
+              ThreadProfilingFeatures::NotProfiled);
+
+    // 'AND Any' doesn't change anything.
+    EXPECT_EQ(Intersect(f1, ThreadProfilingFeatures::Any), f1);
+  }
+
+  for (ThreadProfilingFeatures f1 : scEachAndAnyThreadProfilingFeatures) {
+    EXPECT_TRUE(DoFeaturesIntersect(f1, f1));
+
+    // NotProfiled doesn't intersect with any feature.
+    EXPECT_FALSE(DoFeaturesIntersect(f1, ThreadProfilingFeatures::NotProfiled));
+
+    // Any intersects with any feature.
+    EXPECT_TRUE(DoFeaturesIntersect(f1, ThreadProfilingFeatures::Any));
+  }
+}
+
+static void TestConstUnlockedConstReader(
+    const profiler::ThreadRegistration::UnlockedConstReader& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  EXPECT_STREQ(aData.Info().Name(), "Test thread");
+  EXPECT_GE(aData.Info().RegisterTime(), aBeforeRegistration);
+  EXPECT_LE(aData.Info().RegisterTime(), aAfterRegistration);
+  EXPECT_EQ(aData.Info().ThreadId(), aThreadId);
+  EXPECT_FALSE(aData.Info().IsMainThread());
+
+#if (defined(_MSC_VER) || defined(__MINGW32__)) && defined(MOZ_GECKO_PROFILER)
+  HANDLE threadHandle = aData.PlatformDataCRef().ProfiledThread();
+  EXPECT_NE(threadHandle, nullptr);
+  EXPECT_EQ(ProfilerThreadId::FromNumber(::GetThreadId(threadHandle)),
+            aThreadId);
+  // Test calling QueryThreadCycleTime, we cannot assume that it will always
+  // work, but at least it shouldn't crash.
+  ULONG64 cycles;
+  (void)QueryThreadCycleTime(threadHandle, &cycles);
+#elif defined(__APPLE__) && defined(MOZ_GECKO_PROFILER)
+  // Test calling thread_info, we cannot assume that it will always work, but at
+  // least it shouldn't crash.
+  thread_basic_info_data_t threadBasicInfo;
+  mach_msg_type_number_t basicCount = THREAD_BASIC_INFO_COUNT;
+  (void)thread_info(
+      aData.PlatformDataCRef().ProfiledThread(), THREAD_BASIC_INFO,
+      reinterpret_cast<thread_info_t>(&threadBasicInfo), &basicCount);
+#elif (defined(__linux__) || defined(__ANDROID__) || defined(__FreeBSD__)) && \
+    defined(MOZ_GECKO_PROFILER)
+  // Test calling GetClockId, we cannot assume that it will always work, but at
+  // least it shouldn't crash.
+  Maybe<clockid_t> maybeClockId = aData.PlatformDataCRef().GetClockId();
+  if (maybeClockId) {
+    // Test calling clock_gettime, we cannot assume that it will always work,
+    // but at least it shouldn't crash.
+    timespec ts;
+    (void)clock_gettime(*maybeClockId, &ts);
+  }
+#else
+  (void)aData.PlatformDataCRef();
+#endif
+
+  EXPECT_GE(aData.StackTop(), aOnStackObject)
+      << "StackTop should be at &onStackChar, or higher on some "
+         "platforms";
+};
+
+static void TestConstUnlockedConstReaderAndAtomicRW(
+    const profiler::ThreadRegistration::UnlockedConstReaderAndAtomicRW& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReader(aData, aBeforeRegistration, aAfterRegistration,
+                               aOnStackObject, aThreadId);
+
+  (void)aData.ProfilingStackCRef();
+
+  EXPECT_EQ(aData.ProfilingFeatures(), ThreadProfilingFeatures::NotProfiled);
+
+  EXPECT_FALSE(aData.IsSleeping());
+};
+
+static void TestUnlockedConstReaderAndAtomicRW(
+    profiler::ThreadRegistration::UnlockedConstReaderAndAtomicRW& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                          aAfterRegistration, aOnStackObject,
+                                          aThreadId);
+
+  (void)aData.ProfilingStackRef();
+
+  EXPECT_FALSE(aData.IsSleeping());
+  aData.SetSleeping();
+  EXPECT_TRUE(aData.IsSleeping());
+  aData.SetAwake();
+  EXPECT_FALSE(aData.IsSleeping());
+
+  aData.ReinitializeOnResume();
+
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.SetSleeping();
+  // After sleeping, the 2nd+ calls can duplicate.
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.ReinitializeOnResume();
+  // After reinit (and sleeping), the 2nd+ calls can duplicate.
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_TRUE(aData.CanDuplicateLastSampleDueToSleep());
+  aData.SetAwake();
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+  EXPECT_FALSE(aData.CanDuplicateLastSampleDueToSleep());
+};
+
+static void TestConstUnlockedRWForLockedProfiler(
+    const profiler::ThreadRegistration::UnlockedRWForLockedProfiler& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                          aAfterRegistration, aOnStackObject,
+                                          aThreadId);
+
+  // We can't create a PSAutoLock here, so just verify that the call would
+  // compile and return the expected type.
+  static_assert(std::is_same_v<decltype(aData.GetProfiledThreadData(
+                                   std::declval<PSAutoLock>())),
+                               const ProfiledThreadData*>);
+};
+
+static void TestConstUnlockedReaderAndAtomicRWOnThread(
+    const profiler::ThreadRegistration::UnlockedReaderAndAtomicRWOnThread&
+        aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                       aAfterRegistration, aOnStackObject,
+                                       aThreadId);
+
+  EXPECT_EQ(aData.GetJSContext(), nullptr);
+};
+
+static void TestUnlockedRWForLockedProfiler(
+    profiler::ThreadRegistration::UnlockedRWForLockedProfiler& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                       aAfterRegistration, aOnStackObject,
+                                       aThreadId);
+  TestUnlockedConstReaderAndAtomicRW(aData, aBeforeRegistration,
+                                     aAfterRegistration, aOnStackObject,
+                                     aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestUnlockedReaderAndAtomicRWOnThread(
+    profiler::ThreadRegistration::UnlockedReaderAndAtomicRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                             aAfterRegistration, aOnStackObject,
+                                             aThreadId);
+  TestUnlockedRWForLockedProfiler(aData, aBeforeRegistration,
+                                  aAfterRegistration, aOnStackObject,
+                                  aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestConstLockedRWFromAnyThread(
+    const profiler::ThreadRegistration::LockedRWFromAnyThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                             aAfterRegistration, aOnStackObject,
+                                             aThreadId);
+
+  EXPECT_EQ(aData.GetJsFrameBuffer(), nullptr);
+  EXPECT_EQ(aData.GetEventTarget(), nullptr);
+};
+
+static void TestLockedRWFromAnyThread(
+    profiler::ThreadRegistration::LockedRWFromAnyThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                                 aOnStackObject, aThreadId);
+  TestUnlockedReaderAndAtomicRWOnThread(aData, aBeforeRegistration,
+                                        aAfterRegistration, aOnStackObject,
+                                        aThreadId);
+
+  // We can't create a ProfiledThreadData nor PSAutoLock here, so just verify
+  // that the call would compile and return the expected type.
+  static_assert(std::is_same_v<decltype(aData.SetProfilingFeaturesAndData(
+                                   std::declval<ThreadProfilingFeatures>(),
+                                   std::declval<ProfiledThreadData*>(),
+                                   std::declval<PSAutoLock>())),
+                               void>);
+
+  aData.ResetMainThread(nullptr);
+
+  TimeDuration delay = TimeDuration::FromSeconds(1);
+  TimeDuration running = TimeDuration::FromSeconds(1);
+  aData.GetRunningEventDelay(TimeStamp::Now(), delay, running);
+  EXPECT_TRUE(delay.IsZero());
+  EXPECT_TRUE(running.IsZero());
+
+  aData.StartJSSampling(123u);
+  aData.StopJSSampling();
+};
+
+static void TestConstLockedRWOnThread(
+    const profiler::ThreadRegistration::LockedRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                                 aOnStackObject, aThreadId);
+
+  // No functions to test here.
+};
+
+static void TestLockedRWOnThread(
+    profiler::ThreadRegistration::LockedRWOnThread& aData,
+    const TimeStamp& aBeforeRegistration, const TimeStamp& aAfterRegistration,
+    const void* aOnStackObject,
+    ProfilerThreadId aThreadId = profiler_current_thread_id()) {
+  TestConstLockedRWOnThread(aData, aBeforeRegistration, aAfterRegistration,
+                            aOnStackObject, aThreadId);
+  TestLockedRWFromAnyThread(aData, aBeforeRegistration, aAfterRegistration,
+                            aOnStackObject, aThreadId);
+
+  // We don't want to really call SetJSContext here, so just verify that
+  // the call would compile and return the expected type.
+  static_assert(
+      std::is_same_v<decltype(aData.SetJSContext(std::declval<JSContext*>())),
+                     void>);
+  aData.ClearJSContext();
+  aData.PollJSSampling();
+};
+
+TEST(GeckoProfiler, ThreadRegistration_DataAccess)
+{
+  using TR = profiler::ThreadRegistration;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+    EXPECT_FALSE(TR::GetOnThreadPtr());
+    EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+    char onStackChar;
+
+    TimeStamp beforeRegistration = TimeStamp::Now();
+    TR tr{"Test thread", &onStackChar};
+    TimeStamp afterRegistration = TimeStamp::Now();
+
+    ASSERT_TRUE(TR::IsRegistered());
+
+    // Note: This test will mostly be about checking the correct access to
+    // thread data, depending on how it's obtained. Not all the functionality
+    // related to that data is tested (e.g., because it involves JS or other
+    // external dependencies that would be difficult to control here.)
+
+    auto TestOnThreadRef = [&](TR::OnThreadRef aOnThreadRef) {
+      // To test const-qualified member functions.
+      const TR::OnThreadRef& onThreadCRef = aOnThreadRef;
+
+      // const UnlockedConstReader (always const)
+
+      TestConstUnlockedConstReader(onThreadCRef.UnlockedConstReaderCRef(),
+                                   beforeRegistration, afterRegistration,
+                                   &onStackChar);
+      onThreadCRef.WithUnlockedConstReader(
+          [&](const TR::UnlockedConstReader& aData) {
+            TestConstUnlockedConstReader(aData, beforeRegistration,
+                                         afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedConstReaderAndAtomicRW
+
+      TestConstUnlockedConstReaderAndAtomicRW(
+          onThreadCRef.UnlockedConstReaderAndAtomicRWCRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedConstReaderAndAtomicRW(
+          [&](const TR::UnlockedConstReaderAndAtomicRW& aData) {
+            TestConstUnlockedConstReaderAndAtomicRW(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedConstReaderAndAtomicRW
+
+      TestUnlockedConstReaderAndAtomicRW(
+          aOnThreadRef.UnlockedConstReaderAndAtomicRWRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedConstReaderAndAtomicRW(
+          [&](TR::UnlockedConstReaderAndAtomicRW& aData) {
+            TestUnlockedConstReaderAndAtomicRW(aData, beforeRegistration,
+                                               afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedRWForLockedProfiler
+
+      TestConstUnlockedRWForLockedProfiler(
+          onThreadCRef.UnlockedRWForLockedProfilerCRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedRWForLockedProfiler(
+          [&](const TR::UnlockedRWForLockedProfiler& aData) {
+            TestConstUnlockedRWForLockedProfiler(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedRWForLockedProfiler
+
+      TestUnlockedRWForLockedProfiler(
+          aOnThreadRef.UnlockedRWForLockedProfilerRef(), beforeRegistration,
+          afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedRWForLockedProfiler(
+          [&](TR::UnlockedRWForLockedProfiler& aData) {
+            TestUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                            afterRegistration, &onStackChar);
+          });
+
+      // const UnlockedReaderAndAtomicRWOnThread
+
+      TestConstUnlockedReaderAndAtomicRWOnThread(
+          onThreadCRef.UnlockedReaderAndAtomicRWOnThreadCRef(),
+          beforeRegistration, afterRegistration, &onStackChar);
+      onThreadCRef.WithUnlockedReaderAndAtomicRWOnThread(
+          [&](const TR::UnlockedReaderAndAtomicRWOnThread& aData) {
+            TestConstUnlockedReaderAndAtomicRWOnThread(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // non-const UnlockedReaderAndAtomicRWOnThread
+
+      TestUnlockedReaderAndAtomicRWOnThread(
+          aOnThreadRef.UnlockedReaderAndAtomicRWOnThreadRef(),
+          beforeRegistration, afterRegistration, &onStackChar);
+      aOnThreadRef.WithUnlockedReaderAndAtomicRWOnThread(
+          [&](TR::UnlockedReaderAndAtomicRWOnThread& aData) {
+            TestUnlockedReaderAndAtomicRWOnThread(
+                aData, beforeRegistration, afterRegistration, &onStackChar);
+          });
+
+      // LockedRWFromAnyThread
+      // Note: It cannot directly be accessed on the thread, this will be
+      // tested through LockedRWOnThread.
+
+      // const LockedRWOnThread
+
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      {
+        TR::OnThreadRef::ConstRWOnThreadWithLock constRWOnThreadWithLock =
+            onThreadCRef.ConstLockedRWOnThread();
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestConstLockedRWOnThread(constRWOnThreadWithLock.DataCRef(),
+                                  beforeRegistration, afterRegistration,
+                                  &onStackChar);
+      }
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      onThreadCRef.WithConstLockedRWOnThread(
+          [&](const TR::LockedRWOnThread& aData) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+            TestConstLockedRWOnThread(aData, beforeRegistration,
+                                      afterRegistration, &onStackChar);
+          });
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+      // non-const LockedRWOnThread
+
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      {
+        TR::OnThreadRef::RWOnThreadWithLock rwOnThreadWithLock =
+            aOnThreadRef.GetLockedRWOnThread();
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestConstLockedRWOnThread(rwOnThreadWithLock.DataCRef(),
+                                  beforeRegistration, afterRegistration,
+                                  &onStackChar);
+        TestLockedRWOnThread(rwOnThreadWithLock.DataRef(), beforeRegistration,
+                             afterRegistration, &onStackChar);
+      }
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+      aOnThreadRef.WithLockedRWOnThread([&](TR::LockedRWOnThread& aData) {
+        EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+        TestLockedRWOnThread(aData, beforeRegistration, afterRegistration,
+                             &onStackChar);
+      });
+      EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+    };
+
+    TR::OnThreadPtr onThreadPtr = TR::GetOnThreadPtr();
+    ASSERT_TRUE(onThreadPtr);
+    TestOnThreadRef(*onThreadPtr);
+
+    TR::WithOnThreadRef(
+        [&](TR::OnThreadRef aOnThreadRef) { TestOnThreadRef(aOnThreadRef); });
+
+    EXPECT_TRUE(TR::WithOnThreadRefOr(
+        [&](TR::OnThreadRef aOnThreadRef) {
+          TestOnThreadRef(aOnThreadRef);
+          return true;
+        },
+        false));
+  });
+  testThread.join();
+}
+
+// Thread name if registered, nullptr otherwise.
+static const char* GetThreadName() {
+  return profiler::ThreadRegistration::WithOnThreadRefOr(
+      [](profiler::ThreadRegistration::OnThreadRef onThreadRef) {
+        return onThreadRef.WithUnlockedConstReader(
+            [](const profiler::ThreadRegistration::UnlockedConstReader& aData) {
+              return aData.Info().Name();
+            });
+      },
+      nullptr);
+}
+
+// Get the thread name, as registered in the PRThread, nullptr on failure.
+static const char* GetPRThreadName() {
+  nsIThread* nsThread = NS_GetCurrentThread();
+  if (!nsThread) {
+    return nullptr;
+  }
+  PRThread* prThread = nullptr;
+  if (NS_FAILED(nsThread->GetPRThread(&prThread))) {
+    return nullptr;
+  }
+  if (!prThread) {
+    return nullptr;
+  }
+  return PR_GetThreadName(prThread);
+}
+
+TEST(GeckoProfiler, ThreadRegistration_MainThreadName)
+{
+  EXPECT_TRUE(profiler::ThreadRegistration::IsRegistered());
+  EXPECT_STREQ(GetThreadName(), "GeckoMain");
+
+  // Check that the real thread name (outside the profiler) is *not* GeckoMain.
+  EXPECT_STRNE(GetPRThreadName(), "GeckoMain");
+}
+
+TEST(GeckoProfiler, ThreadRegistration_NestedRegistrations)
+{
+  using TR = profiler::ThreadRegistration;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test actual registrations that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+
+    char onStackChar;
+
+    // Blocks {} are mostly for clarity, but some control on-stack registration
+    // lifetimes.
+
+    // On-stack registration.
+    {
+      TR rt{"Test thread #1", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #1");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #1");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Off-stack registration.
+    {
+      TR::RegisterThread("Test thread #2", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #2");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #2");
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Extra un-registration should be ignored.
+    TR::UnregisterThread();
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested on-stack.
+    {
+      TR rt2{"Test thread #3", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #3");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #3");
+
+      {
+        TR rt3{"Test thread #4", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #3")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #3")
+            << "Nested registration shouldn't change the PRThread name";
+      }
+      ASSERT_TRUE(TR::IsRegistered())
+      << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #3")
+          << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #3");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested off-stack.
+    {
+      TR::RegisterThread("Test thread #5", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #5");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #5");
+
+      {
+        TR::RegisterThread("Test thread #6", &onStackChar);
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #5")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #5")
+            << "Nested registration shouldn't change the PRThread name";
+
+        TR::UnregisterThread();
+        ASSERT_TRUE(TR::IsRegistered())
+        << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetThreadName(), "Test thread #5")
+            << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #5");
+      }
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Nested on- and off-stack.
+    {
+      TR rt2{"Test thread #7", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #7");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #7");
+
+      {
+        TR::RegisterThread("Test thread #8", &onStackChar);
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #7")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #7")
+            << "Nested registration shouldn't change the PRThread name";
+
+        TR::UnregisterThread();
+        ASSERT_TRUE(TR::IsRegistered())
+        << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetThreadName(), "Test thread #7")
+            << "Thread should still be registered after nested un-registration";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #7");
+      }
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Nested off- and on-stack.
+    {
+      TR::RegisterThread("Test thread #9", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #9");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #9");
+
+      {
+        TR rt3{"Test thread #10", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #9")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #9")
+            << "Nested registration shouldn't change the PRThread name";
+      }
+      ASSERT_TRUE(TR::IsRegistered())
+      << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #9")
+          << "Thread should still be registered after nested un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #9");
+
+      TR::UnregisterThread();
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    // Excess UnregisterThread with on-stack TR.
+    {
+      TR rt2{"Test thread #11", &onStackChar};
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #11");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #11");
+
+      TR::UnregisterThread();
+      ASSERT_TRUE(TR::IsRegistered())
+      << "On-stack thread should still be registered after off-stack "
+         "un-registration";
+      EXPECT_STREQ(GetThreadName(), "Test thread #11")
+          << "On-stack thread should still be registered after off-stack "
+             "un-registration";
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #11");
+    }
+    ASSERT_FALSE(TR::IsRegistered());
+
+    // Excess on-thread TR destruction with already-unregistered root off-thread
+    // registration.
+    {
+      TR::RegisterThread("Test thread #12", &onStackChar);
+      ASSERT_TRUE(TR::IsRegistered());
+      EXPECT_STREQ(GetThreadName(), "Test thread #12");
+      EXPECT_STREQ(GetPRThreadName(), "Test thread #12");
+
+      {
+        TR rt3{"Test thread #13", &onStackChar};
+        ASSERT_TRUE(TR::IsRegistered());
+        EXPECT_STREQ(GetThreadName(), "Test thread #12")
+            << "Nested registration shouldn't change the name";
+        EXPECT_STREQ(GetPRThreadName(), "Test thread #12")
+            << "Nested registration shouldn't change the PRThread name";
+
+        // Note that we unregister the root registration, while nested `rt3` is
+        // still alive.
+        TR::UnregisterThread();
+        ASSERT_FALSE(TR::IsRegistered())
+        << "UnregisterThread() of the root RegisterThread() should always work";
+
+        // At this end of this block, `rt3` will be destroyed, but nothing
+        // should happen.
+      }
+      ASSERT_FALSE(TR::IsRegistered());
+    }
+
+    ASSERT_FALSE(TR::IsRegistered());
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistry_DataAccess)
+{
+  using TR = profiler::ThreadRegistration;
+  using TRy = profiler::ThreadRegistry;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  std::thread testThread([&]() {
+    ASSERT_FALSE(TR::IsRegistered())
+    << "A new std::thread should not start registered";
+    EXPECT_FALSE(TR::GetOnThreadPtr());
+    EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+    char onStackChar;
+
+    TimeStamp beforeRegistration = TimeStamp::Now();
+    TR tr{"Test thread", &onStackChar};
+    TimeStamp afterRegistration = TimeStamp::Now();
+
+    ASSERT_TRUE(TR::IsRegistered());
+
+    // Note: This test will mostly be about checking the correct access to
+    // thread data, depending on how it's obtained. Not all the functionality
+    // related to that data is tested (e.g., because it involves JS or other
+    // external dependencies that would be difficult to control here.)
+
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+
+    auto testThroughRegistry = [&]() {
+      auto TestOffThreadRef = [&](TRy::OffThreadRef aOffThreadRef) {
+        // To test const-qualified member functions.
+        const TRy::OffThreadRef& offThreadCRef = aOffThreadRef;
+
+        // const UnlockedConstReader (always const)
+
+        TestConstUnlockedConstReader(offThreadCRef.UnlockedConstReaderCRef(),
+                                     beforeRegistration, afterRegistration,
+                                     &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedConstReader(
+            [&](const TR::UnlockedConstReader& aData) {
+              TestConstUnlockedConstReader(aData, beforeRegistration,
+                                           afterRegistration, &onStackChar,
+                                           testThreadId);
+            });
+
+        // const UnlockedConstReaderAndAtomicRW
+
+        TestConstUnlockedConstReaderAndAtomicRW(
+            offThreadCRef.UnlockedConstReaderAndAtomicRWCRef(),
+            beforeRegistration, afterRegistration, &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedConstReaderAndAtomicRW(
+            [&](const TR::UnlockedConstReaderAndAtomicRW& aData) {
+              TestConstUnlockedConstReaderAndAtomicRW(
+                  aData, beforeRegistration, afterRegistration, &onStackChar,
+                  testThreadId);
+            });
+
+        // non-const UnlockedConstReaderAndAtomicRW
+
+        TestUnlockedConstReaderAndAtomicRW(
+            aOffThreadRef.UnlockedConstReaderAndAtomicRWRef(),
+            beforeRegistration, afterRegistration, &onStackChar, testThreadId);
+        aOffThreadRef.WithUnlockedConstReaderAndAtomicRW(
+            [&](TR::UnlockedConstReaderAndAtomicRW& aData) {
+              TestUnlockedConstReaderAndAtomicRW(aData, beforeRegistration,
+                                                 afterRegistration,
+                                                 &onStackChar, testThreadId);
+            });
+
+        // const UnlockedRWForLockedProfiler
+
+        TestConstUnlockedRWForLockedProfiler(
+            offThreadCRef.UnlockedRWForLockedProfilerCRef(), beforeRegistration,
+            afterRegistration, &onStackChar, testThreadId);
+        offThreadCRef.WithUnlockedRWForLockedProfiler(
+            [&](const TR::UnlockedRWForLockedProfiler& aData) {
+              TestConstUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                                   afterRegistration,
+                                                   &onStackChar, testThreadId);
+            });
+
+        // non-const UnlockedRWForLockedProfiler
+
+        TestUnlockedRWForLockedProfiler(
+            aOffThreadRef.UnlockedRWForLockedProfilerRef(), beforeRegistration,
+            afterRegistration, &onStackChar, testThreadId);
+        aOffThreadRef.WithUnlockedRWForLockedProfiler(
+            [&](TR::UnlockedRWForLockedProfiler& aData) {
+              TestUnlockedRWForLockedProfiler(aData, beforeRegistration,
+                                              afterRegistration, &onStackChar,
+                                              testThreadId);
+            });
+
+        // UnlockedReaderAndAtomicRWOnThread
+        // Note: It cannot directly be accessed off the thread, this will be
+        // tested through LockedRWFromAnyThread.
+
+        // const LockedRWFromAnyThread
+
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        {
+          TRy::OffThreadRef::ConstRWFromAnyThreadWithLock
+              constRWFromAnyThreadWithLock =
+                  offThreadCRef.ConstLockedRWFromAnyThread();
+          if (profiler_current_thread_id() == testThreadId) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+          }
+          TestConstLockedRWFromAnyThread(
+              constRWFromAnyThreadWithLock.DataCRef(), beforeRegistration,
+              afterRegistration, &onStackChar, testThreadId);
+        }
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        offThreadCRef.WithConstLockedRWFromAnyThread(
+            [&](const TR::LockedRWFromAnyThread& aData) {
+              if (profiler_current_thread_id() == testThreadId) {
+                EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+              }
+              TestConstLockedRWFromAnyThread(aData, beforeRegistration,
+                                             afterRegistration, &onStackChar,
+                                             testThreadId);
+            });
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+        // non-const LockedRWFromAnyThread
+
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        {
+          TRy::OffThreadRef::RWFromAnyThreadWithLock rwFromAnyThreadWithLock =
+              aOffThreadRef.GetLockedRWFromAnyThread();
+          if (profiler_current_thread_id() == testThreadId) {
+            EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+          }
+          TestLockedRWFromAnyThread(rwFromAnyThreadWithLock.DataRef(),
+                                    beforeRegistration, afterRegistration,
+                                    &onStackChar, testThreadId);
+        }
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+        aOffThreadRef.WithLockedRWFromAnyThread(
+            [&](TR::LockedRWFromAnyThread& aData) {
+              if (profiler_current_thread_id() == testThreadId) {
+                EXPECT_TRUE(TR::IsDataMutexLockedOnCurrentThread());
+              }
+              TestLockedRWFromAnyThread(aData, beforeRegistration,
+                                        afterRegistration, &onStackChar,
+                                        testThreadId);
+            });
+        EXPECT_FALSE(TR::IsDataMutexLockedOnCurrentThread());
+
+        // LockedRWOnThread
+        // Note: It can never be accessed off the thread.
+      };
+
+      int ranTest = 0;
+      TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef aOffThreadRef) {
+        TestOffThreadRef(aOffThreadRef);
+        ++ranTest;
+      });
+      EXPECT_EQ(ranTest, 1);
+
+      EXPECT_TRUE(TRy::WithOffThreadRefOr(
+          testThreadId,
+          [&](TRy::OffThreadRef aOffThreadRef) {
+            TestOffThreadRef(aOffThreadRef);
+            return true;
+          },
+          false));
+
+      ranTest = 0;
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+      for (TRy::OffThreadRef offThreadRef : TRy::LockedRegistry{}) {
+        EXPECT_TRUE(TRy::IsRegistryMutexLockedOnCurrentThread() ||
+                    !TR::IsRegistered());
+        if (offThreadRef.UnlockedConstReaderCRef().Info().ThreadId() ==
+            testThreadId) {
+          TestOffThreadRef(offThreadRef);
+          ++ranTest;
+        }
+      }
+      EXPECT_EQ(ranTest, 1);
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+
+      {
+        ranTest = 0;
+        EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+        TRy::LockedRegistry lockedRegistry{};
+        EXPECT_TRUE(TRy::IsRegistryMutexLockedOnCurrentThread() ||
+                    !TR::IsRegistered());
+        for (TRy::OffThreadRef offThreadRef : lockedRegistry) {
+          if (offThreadRef.UnlockedConstReaderCRef().Info().ThreadId() ==
+              testThreadId) {
+            TestOffThreadRef(offThreadRef);
+            ++ranTest;
+          }
+        }
+        EXPECT_EQ(ranTest, 1);
+      }
+      EXPECT_FALSE(TRy::IsRegistryMutexLockedOnCurrentThread());
+    };
+
+    // Test on the current thread.
+    testThroughRegistry();
+
+    // Test from another thread.
+    std::thread otherThread([&]() {
+      ASSERT_NE(profiler_current_thread_id(), testThreadId);
+      testThroughRegistry();
+
+      // Test that this unregistered thread is really not registered.
+      int ranTest = 0;
+      TRy::WithOffThreadRef(
+          profiler_current_thread_id(),
+          [&](TRy::OffThreadRef aOffThreadRef) { ++ranTest; });
+      EXPECT_EQ(ranTest, 0);
+
+      EXPECT_FALSE(TRy::WithOffThreadRefOr(
+          profiler_current_thread_id(),
+          [&](TRy::OffThreadRef aOffThreadRef) {
+            ++ranTest;
+            return true;
+          },
+          false));
+      EXPECT_EQ(ranTest, 0);
+    });
+    otherThread.join();
+  });
+  testThread.join();
+}
+
+TEST(GeckoProfiler, ThreadRegistration_RegistrationEdgeCases)
+{
+  using TR = profiler::ThreadRegistration;
+  using TRy = profiler::ThreadRegistry;
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  // Note that the main thread could already be registered, so we work in a new
+  // thread to test an actual registration that we control.
+
+  int registrationCount = 0;
+  int otherThreadLoops = 0;
+  int otherThreadReads = 0;
+
+  // This thread will register and unregister in a loop, with some pauses.
+  // Another thread will attempty to access the test thread, and lock its data.
+  // The main goal is to check edges cases around (un)registrations.
+  std::thread testThread([&]() {
+    const ProfilerThreadId testThreadId = profiler_current_thread_id();
+
+    const TimeStamp endTestAt = TimeStamp::Now() + TimeDuration::FromSeconds(1);
+
+    std::thread otherThread([&]() {
+      // Initial sleep so that testThread can start its loop.
+      PR_Sleep(PR_MillisecondsToInterval(1));
+
+      while (TimeStamp::Now() < endTestAt) {
+        ++otherThreadLoops;
+
+        TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef
+                                                    aOffThreadRef) {
+          if (otherThreadLoops % 1000 == 0) {
+            PR_Sleep(PR_MillisecondsToInterval(1));
+          }
+          TRy::OffThreadRef::RWFromAnyThreadWithLock rwFromAnyThreadWithLock =
+              aOffThreadRef.GetLockedRWFromAnyThread();
+          ++otherThreadReads;
+          if (otherThreadReads % 1000 == 0) {
+            PR_Sleep(PR_MillisecondsToInterval(1));
+          }
+        });
+      }
+    });
+
+    while (TimeStamp::Now() < endTestAt) {
+      ASSERT_FALSE(TR::IsRegistered())
+      << "A new std::thread should not start registered";
+      EXPECT_FALSE(TR::GetOnThreadPtr());
+      EXPECT_FALSE(TR::WithOnThreadRefOr([&](auto) { return true; }, false));
+
+      char onStackChar;
+
+      TR tr{"Test thread", &onStackChar};
+      ++registrationCount;
+
+      ASSERT_TRUE(TR::IsRegistered());
+
+      int ranTest = 0;
+      TRy::WithOffThreadRef(testThreadId, [&](TRy::OffThreadRef aOffThreadRef) {
+        if (registrationCount % 2000 == 0) {
+          PR_Sleep(PR_MillisecondsToInterval(1));
+        }
+        ++ranTest;
+      });
+      EXPECT_EQ(ranTest, 1);
+
+      if (registrationCount % 1000 == 0) {
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    }
+
+    otherThread.join();
+  });
+
+  testThread.join();
+
+  // It's difficult to guess what these numbers should be, but they definitely
+  // should be non-zero. The main goal was to test that nothing goes wrong.
+  EXPECT_GT(registrationCount, 0);
+  EXPECT_GT(otherThreadLoops, 0);
+  EXPECT_GT(otherThreadReads, 0);
+}
+
+#ifdef MOZ_GECKO_PROFILER
+
+TEST(BaseProfiler, BlocksRingBuffer)
+{
+  constexpr uint32_t MBSize = 256;
+  uint8_t buffer[MBSize * 3];
+  for (size_t i = 0; i < MBSize * 3; ++i) {
+    buffer[i] = uint8_t('A' + i);
+  }
+  BlocksRingBuffer rb(BlocksRingBuffer::ThreadSafety::WithMutex,
+                      &buffer[MBSize], MakePowerOfTwo32<MBSize>());
+
+  {
+    nsCString cs("nsCString"_ns);
+    nsString s(u"nsString"_ns);
+    nsAutoCString acs("nsAutoCString"_ns);
+    nsAutoString as(u"nsAutoString"_ns);
+    nsAutoCStringN<8> acs8("nsAutoCStringN"_ns);
+    nsAutoStringN<8> as8(u"nsAutoStringN"_ns);
+    JS::UniqueChars jsuc = JS_smprintf("%s", "JS::UniqueChars");
+
+    rb.PutObjects(cs, s, acs, as, acs8, as8, jsuc);
+  }
+
+  rb.ReadEach([](ProfileBufferEntryReader& aER) {
+    ASSERT_EQ(aER.ReadObject<nsCString>(), "nsCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsString>(), u"nsString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCString>(), "nsAutoCString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoString>(), u"nsAutoString"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoCStringN<8>>(), "nsAutoCStringN"_ns);
+    ASSERT_EQ(aER.ReadObject<nsAutoStringN<8>>(), u"nsAutoStringN"_ns);
+    auto jsuc2 = aER.ReadObject<JS::UniqueChars>();
+    ASSERT_TRUE(!!jsuc2);
+    ASSERT_TRUE(strcmp(jsuc2.get(), "JS::UniqueChars") == 0);
+  });
+
+  // Everything around the sub-buffer should be unchanged.
+  for (size_t i = 0; i < MBSize; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+  for (size_t i = MBSize * 2; i < MBSize * 3; ++i) {
+    ASSERT_EQ(buffer[i], uint8_t('A' + i));
+  }
+}
+
+// Common JSON checks.
+
+// Check that the given JSON string include no JSON whitespace characters
+// (excluding those in property names and strings).
+void JSONWhitespaceCheck(const char* aOutput) {
+  ASSERT_NE(aOutput, nullptr);
+
+  enum class State { Data, String, StringEscaped };
+  State state = State::Data;
+  size_t length = 0;
+  size_t whitespaces = 0;
+  for (const char* p = aOutput; *p != '\0'; ++p) {
+    ++length;
+    const char c = *p;
+
+    switch (state) {
+      case State::Data:
+        if (c == '\n' || c == '\r' || c == ' ' || c == '\t') {
+          ++whitespaces;
+        } else if (c == '"') {
+          state = State::String;
+        }
+        break;
+
+      case State::String:
+        if (c == '"') {
+          state = State::Data;
+        } else if (c == '\\') {
+          state = State::StringEscaped;
+        }
+        break;
+
+      case State::StringEscaped:
+        state = State::String;
+        break;
+    }
+  }
+
+  EXPECT_EQ(whitespaces, 0u);
+  EXPECT_GT(length, 0u);
+}
+
+// Does the GETTER return a non-null TYPE? (Non-critical)
+#  define EXPECT_HAS_JSON(GETTER, TYPE)              \
+    do {                                             \
+      if ((GETTER).isNull()) {                       \
+        EXPECT_FALSE((GETTER).isNull())              \
+            << #GETTER " doesn't exist or is null";  \
+      } else if (!(GETTER).is##TYPE()) {             \
+        EXPECT_TRUE((GETTER).is##TYPE())             \
+            << #GETTER " didn't return type " #TYPE; \
+      }                                              \
+    } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+#  define ASSERT_HAS_JSON(GETTER, TYPE) \
+    do {                                \
+      ASSERT_FALSE((GETTER).isNull());  \
+      ASSERT_TRUE((GETTER).is##TYPE()); \
+    } while (false)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+// If yes, store the reference to Json::Value into VARIABLE.
+#  define GET_JSON(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);         \
+    const Json::Value& VARIABLE = (GETTER)
+
+// Does the GETTER return a non-null TYPE? (Critical)
+// If yes, store the value as `const TYPE` into VARIABLE.
+#  define GET_JSON_VALUE(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);               \
+    const auto VARIABLE = (GETTER).as##TYPE()
+
+// Non-const GET_JSON_VALUE.
+#  define GET_JSON_MUTABLE_VALUE(VARIABLE, GETTER, TYPE) \
+    ASSERT_HAS_JSON(GETTER, TYPE);                       \
+    auto VARIABLE = (GETTER).as##TYPE()
+
+// Checks that the GETTER's value is present, is of the expected TYPE, and has
+// the expected VALUE. (Non-critical)
+#  define EXPECT_EQ_JSON(GETTER, TYPE, VALUE)        \
+    do {                                             \
+      if ((GETTER).isNull()) {                       \
+        EXPECT_FALSE((GETTER).isNull())              \
+            << #GETTER " doesn't exist or is null";  \
+      } else if (!(GETTER).is##TYPE()) {             \
+        EXPECT_TRUE((GETTER).is##TYPE())             \
+            << #GETTER " didn't return type " #TYPE; \
+      } else {                                       \
+        EXPECT_EQ((GETTER).as##TYPE(), (VALUE));     \
+      }                                              \
+    } while (false)
+
+// Checks that the GETTER's value is present, and is a valid index into the
+// STRINGTABLE array, pointing at the expected STRING.
+#  define EXPECT_EQ_STRINGTABLE(GETTER, STRINGTABLE, STRING)                 \
+    do {                                                                     \
+      if ((GETTER).isNull()) {                                               \
+        EXPECT_FALSE((GETTER).isNull())                                      \
+            << #GETTER " doesn't exist or is null";                          \
+      } else if (!(GETTER).isUInt()) {                                       \
+        EXPECT_TRUE((GETTER).isUInt()) << #GETTER " didn't return an index"; \
+      } else {                                                               \
+        EXPECT_LT((GETTER).asUInt(), (STRINGTABLE).size());                  \
+        EXPECT_EQ_JSON((STRINGTABLE)[(GETTER).asUInt()], String, (STRING));  \
+      }                                                                      \
+    } while (false)
+
+#  define EXPECT_JSON_ARRAY_CONTAINS(GETTER, TYPE, VALUE)                     \
+    do {                                                                      \
+      if ((GETTER).isNull()) {                                                \
+        EXPECT_FALSE((GETTER).isNull())                                       \
+            << #GETTER " doesn't exist or is null";                           \
+      } else if (!(GETTER).isArray()) {                                       \
+        EXPECT_TRUE((GETTER).is##TYPE()) << #GETTER " is not an array";       \
+      } else if (const Json::ArrayIndex size = (GETTER).size(); size == 0u) { \
+        EXPECT_NE(size, 0u) << #GETTER " is an empty array";                  \
+      } else {                                                                \
+        bool found = false;                                                   \
+        for (Json::ArrayIndex i = 0; i < size; ++i) {                         \
+          if (!(GETTER)[i].is##TYPE()) {                                      \
+            EXPECT_TRUE((GETTER)[i].is##TYPE())                               \
+                << #GETTER "[" << i << "] is not " #TYPE;                     \
+            break;                                                            \
+          }                                                                   \
+          if ((GETTER)[i].as##TYPE() == (VALUE)) {                            \
+            found = true;                                                     \
+            break;                                                            \
+          }                                                                   \
+        }                                                                     \
+        EXPECT_TRUE(found) << #GETTER " doesn't contain " #VALUE;             \
+      }                                                                       \
+    } while (false)
+
+#  define EXPECT_JSON_ARRAY_EXCLUDES(GETTER, TYPE, VALUE)               \
+    do {                                                                \
+      if ((GETTER).isNull()) {                                          \
+        EXPECT_FALSE((GETTER).isNull())                                 \
+            << #GETTER " doesn't exist or is null";                     \
+      } else if (!(GETTER).isArray()) {                                 \
+        EXPECT_TRUE((GETTER).is##TYPE()) << #GETTER " is not an array"; \
+      } else {                                                          \
+        const Json::ArrayIndex size = (GETTER).size();                  \
+        for (Json::ArrayIndex i = 0; i < size; ++i) {                   \
+          if (!(GETTER)[i].is##TYPE()) {                                \
+            EXPECT_TRUE((GETTER)[i].is##TYPE())                         \
+                << #GETTER "[" << i << "] is not " #TYPE;               \
+            break;                                                      \
+          }                                                             \
+          if ((GETTER)[i].as##TYPE() == (VALUE)) {                      \
+            EXPECT_TRUE((GETTER)[i].as##TYPE() != (VALUE))              \
+                << #GETTER " contains " #VALUE;                         \
+            break;                                                      \
+          }                                                             \
+        }                                                               \
+      }                                                                 \
+    } while (false)
+
+// Check that the given process root contains all the expected properties.
+static void JSONRootCheck(const Json::Value& aRoot,
+                          bool aWithMainThread = true) {
+  ASSERT_TRUE(aRoot.isObject());
+
+  EXPECT_HAS_JSON(aRoot["libs"], Array);
+
+  GET_JSON(meta, aRoot["meta"], Object);
+  EXPECT_HAS_JSON(meta["version"], UInt);
+  EXPECT_HAS_JSON(meta["startTime"], Double);
+  EXPECT_HAS_JSON(meta["profilingStartTime"], Double);
+  EXPECT_HAS_JSON(meta["contentEarliestTime"], Double);
+  EXPECT_HAS_JSON(meta["profilingEndTime"], Double);
+
+  EXPECT_HAS_JSON(aRoot["pages"], Array);
+
+  EXPECT_HAS_JSON(aRoot["profilerOverhead"], Object);
+
+  // "counters" is only present if there is any data to report.
+  // Test that expect "counters" should test for its presence first.
+  if (aRoot.isMember("counters")) {
+    // We have "counters", test their overall validity.
+    GET_JSON(counters, aRoot["counters"], Array);
+    for (const Json::Value& counter : counters) {
+      ASSERT_TRUE(counter.isObject());
+      EXPECT_HAS_JSON(counter["name"], String);
+      EXPECT_HAS_JSON(counter["category"], String);
+      EXPECT_HAS_JSON(counter["description"], String);
+      GET_JSON(sampleGroups, counter["sample_groups"], Array);
+      for (const Json::Value& sampleGroup : sampleGroups) {
+        ASSERT_TRUE(sampleGroup.isObject());
+        EXPECT_HAS_JSON(sampleGroup["id"], UInt);
+
+        GET_JSON(samples, sampleGroup["samples"], Object);
+        GET_JSON(samplesSchema, samples["schema"], Object);
+        EXPECT_GE(samplesSchema.size(), 3u);
+        GET_JSON_VALUE(samplesTime, samplesSchema["time"], UInt);
+        GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+        GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+        GET_JSON(samplesData, samples["data"], Array);
+        double previousTime = 0.0;
+        for (const Json::Value& sample : samplesData) {
+          ASSERT_TRUE(sample.isArray());
+          GET_JSON_VALUE(time, sample[samplesTime], Double);
+          EXPECT_GE(time, previousTime);
+          previousTime = time;
+          if (sample.isValidIndex(samplesNumber)) {
+            EXPECT_HAS_JSON(sample[samplesNumber], UInt64);
+          }
+          if (sample.isValidIndex(samplesCount)) {
+            EXPECT_HAS_JSON(sample[samplesCount], Int64);
+          }
+        }
+      }
+    }
+  }
+
+  GET_JSON(threads, aRoot["threads"], Array);
+  const Json::ArrayIndex threadCount = threads.size();
+  for (Json::ArrayIndex i = 0; i < threadCount; ++i) {
+    GET_JSON(thread, threads[i], Object);
+    EXPECT_HAS_JSON(thread["processType"], String);
+    EXPECT_HAS_JSON(thread["name"], String);
+    EXPECT_HAS_JSON(thread["registerTime"], Double);
+    GET_JSON(samples, thread["samples"], Object);
+    EXPECT_HAS_JSON(thread["markers"], Object);
+    EXPECT_HAS_JSON(thread["pid"], Int64);
+    EXPECT_HAS_JSON(thread["tid"], Int64);
+    GET_JSON(stackTable, thread["stackTable"], Object);
+    GET_JSON(frameTable, thread["frameTable"], Object);
+    GET_JSON(stringTable, thread["stringTable"], Array);
+
+    GET_JSON(stackTableSchema, stackTable["schema"], Object);
+    EXPECT_GE(stackTableSchema.size(), 2u);
+    GET_JSON_VALUE(stackTablePrefix, stackTableSchema["prefix"], UInt);
+    GET_JSON_VALUE(stackTableFrame, stackTableSchema["frame"], UInt);
+    GET_JSON(stackTableData, stackTable["data"], Array);
+
+    GET_JSON(frameTableSchema, frameTable["schema"], Object);
+    EXPECT_GE(frameTableSchema.size(), 1u);
+    GET_JSON_VALUE(frameTableLocation, frameTableSchema["location"], UInt);
+    GET_JSON(frameTableData, frameTable["data"], Array);
+
+    GET_JSON(samplesSchema, samples["schema"], Object);
+    GET_JSON_VALUE(sampleStackIndex, samplesSchema["stack"], UInt);
+    GET_JSON(samplesData, samples["data"], Array);
+    for (const Json::Value& sample : samplesData) {
+      ASSERT_TRUE(sample.isArray());
+      if (sample.isValidIndex(sampleStackIndex)) {
+        if (!sample[sampleStackIndex].isNull()) {
+          GET_JSON_MUTABLE_VALUE(stack, sample[sampleStackIndex], UInt);
+          EXPECT_TRUE(stackTableData.isValidIndex(stack));
+          for (;;) {
+            // `stack` (from the sample, or from the callee frame's "prefix" in
+            // the previous loop) points into the stackTable.
+            GET_JSON(stackTableEntry, stackTableData[stack], Array);
+            GET_JSON_VALUE(frame, stackTableEntry[stackTableFrame], UInt);
+
+            // The stackTable entry's "frame" points into the frameTable.
+            EXPECT_TRUE(frameTableData.isValidIndex(frame));
+            GET_JSON(frameTableEntry, frameTableData[frame], Array);
+            GET_JSON_VALUE(location, frameTableEntry[frameTableLocation], UInt);
+
+            // The frameTable entry's "location" points at a string.
+            EXPECT_TRUE(stringTable.isValidIndex(location));
+
+            // The stackTable entry's "prefix" is null for the root frame.
+            if (stackTableEntry[stackTablePrefix].isNull()) {
+              break;
+            }
+            // Otherwise it recursively points at the caller in the stackTable.
+            GET_JSON_VALUE(prefix, stackTableEntry[stackTablePrefix], UInt);
+            EXPECT_TRUE(stackTableData.isValidIndex(prefix));
+            stack = prefix;
+          }
+        }
+      }
+    }
+  }
+
+  if (aWithMainThread) {
+    ASSERT_GT(threadCount, 0u);
+    GET_JSON(thread0, threads[0], Object);
+    EXPECT_EQ_JSON(thread0["name"], String, "GeckoMain");
+  }
+
+  EXPECT_HAS_JSON(aRoot["pausedRanges"], Array);
+
+  const Json::Value& processes = aRoot["processes"];
+  if (!processes.isNull()) {
+    ASSERT_TRUE(processes.isArray());
+    const Json::ArrayIndex processCount = processes.size();
+    for (Json::ArrayIndex i = 0; i < processCount; ++i) {
+      GET_JSON(process, processes[i], Object);
+      JSONRootCheck(process, aWithMainThread);
+    }
+  }
+
+  GET_JSON(profilingLog, aRoot["profilingLog"], Object);
+  EXPECT_EQ(profilingLog.size(), 1u);
+  for (auto it = profilingLog.begin(); it != profilingLog.end(); ++it) {
+    // The key should be a pid.
+    const auto key = it.name();
+    for (const auto letter : key) {
+      EXPECT_GE(letter, '0');
+      EXPECT_LE(letter, '9');
+    }
+    // And the value should be an object.
+    GET_JSON(logForPid, profilingLog[key], Object);
+    // Its content is not defined, but we expect at least these:
+    EXPECT_HAS_JSON(logForPid["profilingLogBegin_TSms"], Double);
+    EXPECT_HAS_JSON(logForPid["profilingLogEnd_TSms"], Double);
+  }
+}
+
+// Check that various expected top properties are in the JSON, and then call the
+// provided `aJSONCheckFunction` with the JSON root object.
+template <typename JSONCheckFunction>
+void JSONOutputCheck(const char* aOutput,
+                     JSONCheckFunction&& aJSONCheckFunction) {
+  ASSERT_NE(aOutput, nullptr);
+
+  JSONWhitespaceCheck(aOutput);
+
+  // Extract JSON.
+  Json::Value parsedRoot;
+  Json::CharReaderBuilder builder;
+  const std::unique_ptr<Json::CharReader> reader(builder.newCharReader());
+  ASSERT_TRUE(
+      reader->parse(aOutput, strchr(aOutput, '\0'), &parsedRoot, nullptr));
+
+  JSONRootCheck(parsedRoot);
+
+  std::forward<JSONCheckFunction>(aJSONCheckFunction)(parsedRoot);
+}
+
+// Returns `static_cast<SamplingState>(-1)` if callback could not be installed.
+static SamplingState WaitForSamplingState() {
+  Atomic<int> samplingState{-1};
+
+  if (!profiler_callback_after_sampling([&](SamplingState aSamplingState) {
+        samplingState = static_cast<int>(aSamplingState);
+      })) {
+    return static_cast<SamplingState>(-1);
+  }
+
+  while (samplingState == -1) {
+  }
+
+  return static_cast<SamplingState>(static_cast<int>(samplingState));
+}
+
+typedef Vector<const char*> StrVec;
+
+static void InactiveFeaturesAndParamsCheck() {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeTabID;
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+  ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::NativeAllocations));
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeTabID);
+
+  ASSERT_TRUE(entries == 0);
+  ASSERT_TRUE(duration == Nothing());
+  ASSERT_TRUE(interval == 0);
+  ASSERT_TRUE(features == 0);
+  ASSERT_TRUE(filters.empty());
+  ASSERT_TRUE(activeTabID == 0);
+}
+
+static void ActiveParamsCheck(int aEntries, double aInterval,
+                              uint32_t aFeatures, const char** aFilters,
+                              size_t aFiltersLen, uint64_t aActiveTabID,
+                              const Maybe<double>& aDuration = Nothing()) {
+  int entries;
+  Maybe<double> duration;
+  double interval;
+  uint32_t features;
+  StrVec filters;
+  uint64_t activeTabID;
+
+  profiler_get_start_params(&entries, &duration, &interval, &features, &filters,
+                            &activeTabID);
+
+  ASSERT_TRUE(entries == aEntries);
+  ASSERT_TRUE(duration == aDuration);
+  ASSERT_TRUE(interval == aInterval);
+  ASSERT_TRUE(features == aFeatures);
+  ASSERT_TRUE(filters.length() == aFiltersLen);
+  ASSERT_TRUE(activeTabID == aActiveTabID);
+  for (size_t i = 0; i < aFiltersLen; i++) {
+    ASSERT_TRUE(strcmp(filters[i], aFilters[i]) == 0);
+  }
+}
+
+TEST(GeckoProfiler, FeaturesAndParams)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  // Try a couple of features and filters.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+#  define PROFILER_DEFAULT_DURATION 20 /* seconds, for tests only */
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 100,
+                   Some(PROFILER_DEFAULT_DURATION));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 100,
+                      Some(PROFILER_DEFAULT_DURATION));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try some different features and filters.
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    // Testing with some arbitrary buffer size (as could be provided by
+    // external code), which we convert to the appropriate power of 2.
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 123, Some(25.0));
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try with no duration
+  {
+    uint32_t features =
+        ProfilerFeature::MainThreadIO | ProfilerFeature::IPCMessages;
+    const char* filters[] = {"GeckoMain", "Foo", "Bar"};
+
+    profiler_start(PowerOfTwo32(999999), 3, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(int(PowerOfTwo32(999999).Value()), 3, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Try all supported features, and filters that match all threads.
+  {
+    uint32_t availableFeatures = profiler_get_available_features();
+    const char* filters[] = {""};
+
+    profiler_start(PowerOfTwo32(88888), 10, availableFeatures, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PowerOfTwo32(88888).Value(), 10, availableFeatures,
+                      filters, MOZ_ARRAY_LENGTH(filters), 0, Some(15.0));
+
+    // Don't call profiler_stop() here.
+  }
+
+  // Try no features, and filters that match no threads.
+  {
+    uint32_t features = 0;
+    const char* filters[] = {"NoThreadWillMatchThis"};
+
+    // Second profiler_start() call in a row without an intervening
+    // profiler_stop(); this will do an implicit profiler_stop() and restart.
+    profiler_start(PowerOfTwo32(0), 0, features, filters,
+                   MOZ_ARRAY_LENGTH(filters), 0, Some(0.0));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    // Entries and intervals go to defaults if 0 is specified.
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0, Nothing());
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+
+    // These calls are no-ops.
+    profiler_stop();
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, EnsureStarted)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  uint32_t features = ProfilerFeature::JS;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+  {
+    // Inactive -> Active
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+  }
+
+  {
+    // Active -> Active with same settings
+
+    Maybe<ProfilerBufferInfo> info0 = profiler_get_buffer_info();
+    ASSERT_TRUE(info0->mRangeEnd > 0);
+
+    // First, write some samples into the buffer.
+    PR_Sleep(PR_MillisecondsToInterval(500));
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+    ASSERT_TRUE(info1->mRangeEnd > info0->mRangeEnd);
+
+    // Call profiler_ensure_started with the same settings as before.
+    // This operation must not clear our buffer!
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            features, filters, MOZ_ARRAY_LENGTH(filters), 0,
+                            Some(PROFILER_DEFAULT_DURATION));
+
+    ActiveParamsCheck(
+        PROFILER_DEFAULT_ENTRIES.Value(), PROFILER_DEFAULT_INTERVAL, features,
+        filters, MOZ_ARRAY_LENGTH(filters), 0, Some(PROFILER_DEFAULT_DURATION));
+
+    // Check that our position in the buffer stayed the same or advanced, but
+    // not by much, and the range-start after profiler_ensure_started shouldn't
+    // have passed the range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeEnd >= info1->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeEnd - info1->mRangeEnd <
+                info1->mRangeEnd - info0->mRangeEnd);
+    ASSERT_TRUE(info2->mRangeStart < info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Active with *different* settings
+
+    Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+
+    // Call profiler_ensure_started with a different feature set than the one
+    // it's currently running with. This is supposed to stop and restart the
+    // profiler, thereby discarding the buffer contents.
+    uint32_t differentFeatures = features | ProfilerFeature::CPUUtilization;
+    profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                            differentFeatures, filters,
+                            MOZ_ARRAY_LENGTH(filters), 0);
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, differentFeatures, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    // Check the the buffer was cleared, so its range-start should be at/after
+    // its range-end before.
+    Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+    ASSERT_TRUE(info2->mRangeStart >= info1->mRangeEnd);
+  }
+
+  {
+    // Active -> Inactive
+
+    profiler_stop();
+
+    InactiveFeaturesAndParamsCheck();
+  }
+}
+
+TEST(GeckoProfiler, MultiRegistration)
+{
+  // This whole test only checks that function calls don't crash, they don't
+  // actually verify that threads get profiled or not.
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread, no unreg", &top);
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() { profiler_unregister_thread(); });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread 1st", &top);
+      profiler_unregister_thread();
+      profiler_register_thread("thread 2nd", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread once", &top);
+      profiler_register_thread("thread again", &top);
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+
+  {
+    std::thread thread([]() {
+      char top;
+      profiler_register_thread("thread to unreg twice", &top);
+      profiler_unregister_thread();
+      profiler_unregister_thread();
+    });
+    thread.join();
+  }
+}
+
+TEST(GeckoProfiler, DifferentThreads)
+{
+  InactiveFeaturesAndParamsCheck();
+
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  // Control the profiler on a background thread and verify flags on the
+  // main thread.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    NS_DispatchAndSpinEventLoopUntilComplete(
+        "GeckoProfiler_DifferentThreads_Test::TestBody"_ns, thread,
+        NS_NewRunnableFunction(
+            "GeckoProfiler_DifferentThreads_Test::TestBody", [&]() {
+              profiler_start(PROFILER_DEFAULT_ENTRIES,
+                             PROFILER_DEFAULT_INTERVAL, features, filters,
+                             MOZ_ARRAY_LENGTH(filters), 0);
+            }));
+
+    ASSERT_TRUE(profiler_is_active());
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::MainThreadIO));
+    ASSERT_TRUE(!profiler_feature_active(ProfilerFeature::IPCMessages));
+
+    ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                      PROFILER_DEFAULT_INTERVAL, features, filters,
+                      MOZ_ARRAY_LENGTH(filters), 0);
+
+    NS_DispatchAndSpinEventLoopUntilComplete(
+        "GeckoProfiler_DifferentThreads_Test::TestBody"_ns, thread,
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { profiler_stop(); }));
+
+    InactiveFeaturesAndParamsCheck();
+  }
+
+  // Control the profiler on the main thread and verify flags on a
+  // background thread.
+  {
+    uint32_t features = ProfilerFeature::JS;
+    const char* filters[] = {"GeckoMain", "Compositor"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    NS_DispatchAndSpinEventLoopUntilComplete(
+        "GeckoProfiler_DifferentThreads_Test::TestBody"_ns, thread,
+        NS_NewRunnableFunction(
+            "GeckoProfiler_DifferentThreads_Test::TestBody", [&]() {
+              ASSERT_TRUE(profiler_is_active());
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::MainThreadIO));
+              ASSERT_TRUE(
+                  !profiler_feature_active(ProfilerFeature::IPCMessages));
+
+              ActiveParamsCheck(PROFILER_DEFAULT_ENTRIES.Value(),
+                                PROFILER_DEFAULT_INTERVAL, features, filters,
+                                MOZ_ARRAY_LENGTH(filters), 0);
+            }));
+
+    profiler_stop();
+
+    NS_DispatchAndSpinEventLoopUntilComplete(
+        "GeckoProfiler_DifferentThreads_Test::TestBody"_ns, thread,
+        NS_NewRunnableFunction("GeckoProfiler_DifferentThreads_Test::TestBody",
+                               [&]() { InactiveFeaturesAndParamsCheck(); }));
+  }
+
+  thread->Shutdown();
+}
+
+TEST(GeckoProfiler, GetBacktrace)
+{
+  ASSERT_TRUE(!profiler_get_backtrace());
+
+  {
+    uint32_t features = ProfilerFeature::StackWalk;
+    const char* filters[] = {"GeckoMain"};
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    // These will be destroyed while the profiler is active.
+    static const int N = 100;
+    {
+      UniqueProfilerBacktrace u[N];
+      for (int i = 0; i < N; i++) {
+        u[i] = profiler_get_backtrace();
+        ASSERT_TRUE(u[i]);
+      }
+    }
+
+    // These will be destroyed after the profiler stops.
+    UniqueProfilerBacktrace u[N];
+    for (int i = 0; i < N; i++) {
+      u[i] = profiler_get_backtrace();
+      ASSERT_TRUE(u[i]);
+    }
+
+    profiler_stop();
+  }
+
+  ASSERT_TRUE(!profiler_get_backtrace());
+}
+
+TEST(GeckoProfiler, Pause)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test must run on the main thread";
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain", "Profiled GeckoProfiler.Pause"};
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                   features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - before start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - before start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                  features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after start");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+  }}.join();
+
+  // Check that we are writing samples while not paused.
+  Maybe<ProfilerBufferInfo> info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  Maybe<ProfilerBufferInfo> info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  // Check that we are writing markers while not paused.
+  ASSERT_TRUE(profiler_thread_is_being_profiled_for_markers());
+  ASSERT_TRUE(
+      profiler_thread_is_being_profiled_for_markers(ProfilerThreadId{}));
+  ASSERT_TRUE(profiler_thread_is_being_profiled_for_markers(
+      profiler_current_thread_id()));
+  ASSERT_TRUE(
+      profiler_thread_is_being_profiled_for_markers(profiler_main_thread_id()));
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Not paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd != info2->mRangeEnd);
+
+  profiler_pause();
+
+  ASSERT_TRUE(profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+  }
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers());
+  ASSERT_TRUE(
+      !profiler_thread_is_being_profiled_for_markers(ProfilerThreadId{}));
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers(
+      profiler_current_thread_id()));
+  ASSERT_TRUE(!profiler_thread_is_being_profiled_for_markers(
+      profiler_main_thread_id()));
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after pause");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after pause");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+
+  // Check that we are not writing samples while paused.
+  info1 = profiler_get_buffer_info();
+  PR_Sleep(PR_MillisecondsToInterval(500));
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+
+  // Check that we are now writing markers while paused.
+  info1 = profiler_get_buffer_info();
+  PROFILER_MARKER_UNTYPED("Paused", OTHER, {});
+  info2 = profiler_get_buffer_info();
+  ASSERT_TRUE(info1->mRangeEnd == info2->mRangeEnd);
+  PROFILER_MARKER_UNTYPED("Paused v2", OTHER, {});
+  Maybe<ProfilerBufferInfo> info3 = profiler_get_buffer_info();
+  ASSERT_TRUE(info2->mRangeEnd == info3->mRangeEnd);
+
+  profiler_resume();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                  features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Ignored GeckoProfiler.Pause - after resume");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after resume");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(profiler_thread_is_being_profiled(profiler_main_thread_id(),
+                                                      features));
+      }
+    }
+  }}.join();
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_paused());
+  for (ThreadProfilingFeatures features : scEachAndAnyThreadProfilingFeatures) {
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+    ASSERT_TRUE(
+        !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+    ASSERT_TRUE(!profiler_thread_is_being_profiled(profiler_current_thread_id(),
+                                                   features));
+  }
+
+  std::thread{[&]() {
+    {
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD("Ignored GeckoProfiler.Pause - after stop");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+    {
+      AUTO_PROFILER_REGISTER_THREAD(
+          "Profiled GeckoProfiler.Pause - after stop");
+      for (ThreadProfilingFeatures features :
+           scEachAndAnyThreadProfilingFeatures) {
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(features));
+        ASSERT_TRUE(
+            !profiler_thread_is_being_profiled(ProfilerThreadId{}, features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_current_thread_id(), features));
+        ASSERT_TRUE(!profiler_thread_is_being_profiled(
+            profiler_main_thread_id(), features));
+      }
+    }
+  }}.join();
+}
+
+TEST(GeckoProfiler, Markers)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  PROFILER_MARKER("tracing event", OTHER, {}, Tracing, "A");
+  PROFILER_MARKER("tracing start", OTHER, MarkerTiming::IntervalStart(),
+                  Tracing, "A");
+  PROFILER_MARKER("tracing end", OTHER, MarkerTiming::IntervalEnd(), Tracing,
+                  "A");
+
+  auto bt = profiler_capture_backtrace();
+  PROFILER_MARKER("tracing event with stack", OTHER,
+                  MarkerStack::TakeBacktrace(std::move(bt)), Tracing, "B");
+
+  { AUTO_PROFILER_TRACING_MARKER("C", "auto tracing", OTHER); }
+
+  PROFILER_MARKER_UNTYPED("M1", OTHER, {});
+  PROFILER_MARKER_UNTYPED("M3", OTHER, {});
+
+  // Create three strings: two that are the maximum allowed length, and one that
+  // is one char longer.
+  static const size_t kMax = ProfileBuffer::kMaxFrameKeyLength;
+  UniquePtr<char[]> okstr1 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> okstr2 = MakeUnique<char[]>(kMax);
+  UniquePtr<char[]> longstr = MakeUnique<char[]>(kMax + 1);
+  UniquePtr<char[]> longstrCut = MakeUnique<char[]>(kMax + 1);
+  for (size_t i = 0; i < kMax; i++) {
+    okstr1[i] = 'a';
+    okstr2[i] = 'b';
+    longstr[i] = 'c';
+    longstrCut[i] = 'c';
+  }
+  okstr1[kMax - 1] = '\0';
+  okstr2[kMax - 1] = '\0';
+  longstr[kMax] = '\0';
+  longstrCut[kMax] = '\0';
+  // Should be output as-is.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, "");
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, okstr1.get());
+  // Should be output as label + space + okstr2.
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("okstr2", LAYOUT, okstr2.get());
+  // Should be output with kMax length, ending with "...\0".
+  AUTO_PROFILER_LABEL_DYNAMIC_CSTR("", LAYOUT, longstr.get());
+  ASSERT_EQ(longstrCut[kMax - 4], 'c');
+  longstrCut[kMax - 4] = '.';
+  ASSERT_EQ(longstrCut[kMax - 3], 'c');
+  longstrCut[kMax - 3] = '.';
+  ASSERT_EQ(longstrCut[kMax - 2], 'c');
+  longstrCut[kMax - 2] = '.';
+  ASSERT_EQ(longstrCut[kMax - 1], 'c');
+  longstrCut[kMax - 1] = '\0';
+
+  // Test basic markers 2.0.
+  EXPECT_TRUE(
+      profiler_add_marker("default-templated markers 2.0 with empty options",
+                          geckoprofiler::category::OTHER, {}));
+
+  PROFILER_MARKER_UNTYPED(
+      "default-templated markers 2.0 with option", OTHER,
+      MarkerStack::TakeBacktrace(profiler_capture_backtrace()));
+
+  PROFILER_MARKER("explicitly-default-templated markers 2.0 with empty options",
+                  OTHER, {}, NoPayload);
+
+  EXPECT_TRUE(profiler_add_marker(
+      "explicitly-default-templated markers 2.0 with option",
+      geckoprofiler::category::OTHER, {},
+      ::geckoprofiler::markers::NoPayload{}));
+
+  // Used in markers below.
+  TimeStamp ts1 = TimeStamp::Now();
+
+  // Sleep briefly to ensure a sample is taken and the pending markers are
+  // processed.
+  PR_Sleep(PR_MillisecondsToInterval(500));
+
+  // Used in markers below.
+  TimeStamp ts2 = TimeStamp::Now();
+  // ts1 and ts2 should be different thanks to the sleep.
+  EXPECT_NE(ts1, ts2);
+
+  // Test most marker payloads.
+
+  // Keep this one first! (It's used to record `ts1` and `ts2`, to compare
+  // to serialized numbers in other markers.)
+  EXPECT_TRUE(profiler_add_marker("FirstMarker", geckoprofiler::category::OTHER,
+                                  MarkerTiming::Interval(ts1, ts2),
+                                  geckoprofiler::markers::TextMarker{},
+                                  "First Marker"));
+
+  // User-defined marker type with different properties, and fake schema.
+  struct GtestMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter, int aInt,
+        double aDouble, const mozilla::ProfilerString8View& aText,
+        const mozilla::ProfilerString8View& aUniqueText,
+        const mozilla::TimeStamp& aTime) {
+      aWriter.NullProperty("null");
+      aWriter.BoolProperty("bool-false", false);
+      aWriter.BoolProperty("bool-true", true);
+      aWriter.IntProperty("int", aInt);
+      aWriter.DoubleProperty("double", aDouble);
+      aWriter.StringProperty("text", aText);
+      aWriter.UniqueStringProperty("unique text", aUniqueText);
+      aWriter.UniqueStringProperty("unique text again", aUniqueText);
+      aWriter.TimeProperty("time", aTime);
+    }
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      // Note: This is an test function that is not intended to actually output
+      // that correctly matches StreamJSONMarkerData data above! Instead we only
+      // test that it outputs the expected JSON at the end.
+      using MS = mozilla::MarkerSchema;
+      MS schema{MS::Location::MarkerChart,      MS::Location::MarkerTable,
+                MS::Location::TimelineOverview, MS::Location::TimelineMemory,
+                MS::Location::TimelineIPC,      MS::Location::TimelineFileIO,
+                MS::Location::StackChart};
+      // All label functions.
+      schema.SetChartLabel("chart label");
+      schema.SetTooltipLabel("tooltip label");
+      schema.SetTableLabel("table label");
+      // All data functions, all formats, all "searchable" values.
+      schema.AddKeyFormat("key with url", MS::Format::Url);
+      schema.AddKeyLabelFormat("key with label filePath", "label filePath",
+                               MS::Format::FilePath);
+      schema.AddKeyFormatSearchable("key with string not-searchable",
+                                    MS::Format::String,
+                                    MS::Searchable::NotSearchable);
+      schema.AddKeyLabelFormatSearchable("key with label duration searchable",
+                                         "label duration", MS::Format::Duration,
+                                         MS::Searchable::Searchable);
+      schema.AddKeyFormat("key with time", MS::Format::Time);
+      schema.AddKeyFormat("key with seconds", MS::Format::Seconds);
+      schema.AddKeyFormat("key with milliseconds", MS::Format::Milliseconds);
+      schema.AddKeyFormat("key with microseconds", MS::Format::Microseconds);
+      schema.AddKeyFormat("key with nanoseconds", MS::Format::Nanoseconds);
+      schema.AddKeyFormat("key with bytes", MS::Format::Bytes);
+      schema.AddKeyFormat("key with percentage", MS::Format::Percentage);
+      schema.AddKeyFormat("key with integer", MS::Format::Integer);
+      schema.AddKeyFormat("key with decimal", MS::Format::Decimal);
+      schema.AddStaticLabelValue("static label", "static value");
+      return schema;
+    }
+  };
+  EXPECT_TRUE(
+      profiler_add_marker("Gtest custom marker", geckoprofiler::category::OTHER,
+                          MarkerTiming::Interval(ts1, ts2), GtestMarker{}, 42,
+                          43.0, "gtest text", "gtest unique text", ts1));
+
+  // User-defined marker type with no data, special frontend schema.
+  struct GtestSpecialMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-special");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+  EXPECT_TRUE(profiler_add_marker("Gtest special marker",
+                                  geckoprofiler::category::OTHER, {},
+                                  GtestSpecialMarker{}));
+
+  // User-defined marker type that is never used, so it shouldn't appear in the
+  // output.
+  struct GtestUnusedMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-unused");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {}
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+
+  // Make sure the compiler doesn't complain about this unused struct.
+  mozilla::Unused << GtestUnusedMarker{};
+
+  // Other markers in alphabetical order of payload class names.
+
+  nsCOMPtr<nsIURI> uri;
+  ASSERT_TRUE(
+      NS_SUCCEEDED(NS_NewURI(getter_AddRefs(uri), "http://mozilla.org/"_ns)));
+  // The marker name will be "Load <aChannelId>: <aURI>".
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 1,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_START,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheHit,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      /* nsIURI* aRedirectURI = nullptr */
+      /* uint64_t aRedirectChannelId = 0 */
+  );
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 2,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_STOP,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      Some(nsDependentCString("text/html")),
+      /* nsIURI* aRedirectURI = nullptr */ nullptr,
+      /* uint64_t aRedirectChannelId = 0 */ 0);
+
+  nsCOMPtr<nsIURI> redirectURI;
+  ASSERT_TRUE(NS_SUCCEEDED(
+      NS_NewURI(getter_AddRefs(redirectURI), "http://example.com/"_ns)));
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 3,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */
+      nsIChannelEventSink::REDIRECT_TEMPORARY,
+      /* uint64_t aRedirectChannelId = 0 */ 103);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 4,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */
+      nsIChannelEventSink::REDIRECT_PERMANENT,
+      /* uint64_t aRedirectChannelId = 0 */ 104);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 5,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */ nsIChannelEventSink::REDIRECT_INTERNAL,
+      /* uint64_t aRedirectChannelId = 0 */ 105);
+
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 6,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_REDIRECT,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ false,
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */ nullptr,
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      nullptr,
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      mozilla::Nothing(),
+      /* nsIURI* aRedirectURI = nullptr */ redirectURI,
+      /* uint32_t aRedirectFlags = 0 */ nsIChannelEventSink::REDIRECT_INTERNAL |
+          nsIChannelEventSink::REDIRECT_STS_UPGRADE,
+      /* uint64_t aRedirectChannelId = 0 */ 106);
+  profiler_add_network_marker(
+      /* nsIURI* aURI */ uri,
+      /* const nsACString& aRequestMethod */ "GET"_ns,
+      /* int32_t aPriority */ 34,
+      /* uint64_t aChannelId */ 7,
+      /* NetworkLoadType aType */ net::NetworkLoadType::LOAD_START,
+      /* mozilla::TimeStamp aStart */ ts1,
+      /* mozilla::TimeStamp aEnd */ ts2,
+      /* int64_t aCount */ 56,
+      /* mozilla::net::CacheDisposition aCacheDisposition */
+      net::kCacheUnresolved,
+      /* uint64_t aInnerWindowID */ 78,
+      /* bool aIsPrivateBrowsing */ true
+      /* const mozilla::net::TimingStruct* aTimings = nullptr */
+      /* mozilla::UniquePtr<mozilla::ProfileChunkedBuffer> aSource =
+         nullptr */
+      /* const mozilla::Maybe<nsDependentCString>& aContentType =
+         mozilla::Nothing() */
+      /* nsIURI* aRedirectURI = nullptr */
+      /* uint64_t aRedirectChannelId = 0 */
+  );
+
+  EXPECT_TRUE(profiler_add_marker(
+      "Text in main thread with stack", geckoprofiler::category::OTHER,
+      {MarkerStack::Capture(), MarkerTiming::Interval(ts1, ts2)},
+      geckoprofiler::markers::TextMarker{}, ""));
+  EXPECT_TRUE(profiler_add_marker(
+      "Text from main thread with stack", geckoprofiler::category::OTHER,
+      MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+      geckoprofiler::markers::TextMarker{}, ""));
+
+  std::thread registeredThread([]() {
+    AUTO_PROFILER_REGISTER_THREAD("Marker test sub-thread");
+    // Marker in non-profiled thread won't be stored.
+    EXPECT_FALSE(profiler_add_marker(
+        "Text in registered thread with stack", geckoprofiler::category::OTHER,
+        MarkerStack::Capture(), geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, with stack from registered thread.
+    EXPECT_TRUE(profiler_add_marker(
+        "Text from registered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  registeredThread.join();
+
+  std::thread unregisteredThread([]() {
+    // Marker in unregistered thread won't be stored.
+    EXPECT_FALSE(profiler_add_marker("Text in unregistered thread with stack",
+                                     geckoprofiler::category::OTHER,
+                                     MarkerStack::Capture(),
+                                     geckoprofiler::markers::TextMarker{}, ""));
+    // Marker will be stored in main thread, but stack cannot be captured in an
+    // unregistered thread.
+    EXPECT_TRUE(profiler_add_marker(
+        "Text from unregistered thread with stack",
+        geckoprofiler::category::OTHER,
+        MarkerOptions(MarkerThreadId::MainThread(), MarkerStack::Capture()),
+        geckoprofiler::markers::TextMarker{}, ""));
+  });
+  unregisteredThread.join();
+
+  EXPECT_TRUE(profiler_add_marker("Tracing", geckoprofiler::category::OTHER, {},
+                                  geckoprofiler::markers::Tracing{},
+                                  "category"));
+
+  EXPECT_TRUE(profiler_add_marker("Text", geckoprofiler::category::OTHER, {},
+                                  geckoprofiler::markers::TextMarker{},
+                                  "Text text"));
+
+  // Ensure that we evaluate to false for markers with very long texts by
+  // testing against a ~3mb string. A string of this size should exceed the
+  // available buffer chunks (max: 2) that are available and be discarded.
+  EXPECT_FALSE(profiler_add_marker("Text", geckoprofiler::category::OTHER, {},
+                                   geckoprofiler::markers::TextMarker{},
+                                   std::string(3 * 1024 * 1024, 'x')));
+
+  EXPECT_TRUE(profiler_add_marker(
+      "MediaSample", geckoprofiler::category::OTHER, {},
+      geckoprofiler::markers::MediaSampleMarker{}, 123, 456, 789));
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  w.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w).isOk());
+  w.End();
+
+  EXPECT_FALSE(w.Failed());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile.get());
+
+  // Expected markers, in order.
+  enum State {
+    S_tracing_event,
+    S_tracing_start,
+    S_tracing_end,
+    S_tracing_event_with_stack,
+    S_tracing_auto_tracing_start,
+    S_tracing_auto_tracing_end,
+    S_M1,
+    S_M3,
+    S_Markers2DefaultEmptyOptions,
+    S_Markers2DefaultWithOptions,
+    S_Markers2ExplicitDefaultEmptyOptions,
+    S_Markers2ExplicitDefaultWithOptions,
+    S_FirstMarker,
+    S_CustomMarker,
+    S_SpecialMarker,
+    S_NetworkMarkerPayload_start,
+    S_NetworkMarkerPayload_stop,
+    S_NetworkMarkerPayload_redirect_temporary,
+    S_NetworkMarkerPayload_redirect_permanent,
+    S_NetworkMarkerPayload_redirect_internal,
+    S_NetworkMarkerPayload_redirect_internal_sts,
+    S_NetworkMarkerPayload_private_browsing,
+
+    S_TextWithStack,
+    S_TextToMTWithStack,
+    S_RegThread_TextToMTWithStack,
+    S_UnregThread_TextToMTWithStack,
+
+    S_LAST,
+  } state = State(0);
+
+  // These will be set when first read from S_FirstMarker, then
+  // compared in following markers.
+  // TODO: Compute these values from the timestamps.
+  double ts1Double = 0.0;
+  double ts2Double = 0.0;
+
+  JSONOutputCheck(profile.get(), [&](const Json::Value& root) {
+    {
+      GET_JSON(threads, root["threads"], Array);
+      ASSERT_EQ(threads.size(), 1u);
+
+      {
+        GET_JSON(thread0, threads[0], Object);
+
+        // Keep a reference to the string table in this block, it will be used
+        // below.
+        GET_JSON(stringTable, thread0["stringTable"], Array);
+        ASSERT_TRUE(stringTable.isArray());
+
+        // Test the expected labels in the string table.
+        bool foundEmpty = false;
+        bool foundOkstr1 = false;
+        bool foundOkstr2 = false;
+        const std::string okstr2Label = std::string("okstr2 ") + okstr2.get();
+        bool foundTooLong = false;
+        for (const auto& s : stringTable) {
+          ASSERT_TRUE(s.isString());
+          std::string sString = s.asString();
+          if (sString.empty()) {
+            EXPECT_FALSE(foundEmpty);
+            foundEmpty = true;
+          } else if (sString == okstr1.get()) {
+            EXPECT_FALSE(foundOkstr1);
+            foundOkstr1 = true;
+          } else if (sString == okstr2Label) {
+            EXPECT_FALSE(foundOkstr2);
+            foundOkstr2 = true;
+          } else if (sString == longstrCut.get()) {
+            EXPECT_FALSE(foundTooLong);
+            foundTooLong = true;
+          } else {
+            EXPECT_NE(sString, longstr.get());
+          }
+        }
+        EXPECT_TRUE(foundEmpty);
+        EXPECT_TRUE(foundOkstr1);
+        EXPECT_TRUE(foundOkstr2);
+        EXPECT_TRUE(foundTooLong);
+
+        {
+          GET_JSON(markers, thread0["markers"], Object);
+
+          {
+            GET_JSON(data, markers["data"], Array);
+
+            for (const Json::Value& marker : data) {
+              // Name the indexes into the marker tuple:
+              // [name, startTime, endTime, phase, category, payload]
+              const unsigned int NAME = 0u;
+              const unsigned int START_TIME = 1u;
+              const unsigned int END_TIME = 2u;
+              const unsigned int PHASE = 3u;
+              const unsigned int CATEGORY = 4u;
+              const unsigned int PAYLOAD = 5u;
+
+              const unsigned int PHASE_INSTANT = 0;
+              const unsigned int PHASE_INTERVAL = 1;
+              const unsigned int PHASE_START = 2;
+              const unsigned int PHASE_END = 3;
+
+              const unsigned int SIZE_WITHOUT_PAYLOAD = 5u;
+              const unsigned int SIZE_WITH_PAYLOAD = 6u;
+
+              ASSERT_TRUE(marker.isArray());
+              // The payload is optional.
+              ASSERT_GE(marker.size(), SIZE_WITHOUT_PAYLOAD);
+              ASSERT_LE(marker.size(), SIZE_WITH_PAYLOAD);
+
+              // root.threads[0].markers.data[i] is an array with 5 or 6
+              // elements.
+
+              ASSERT_TRUE(marker[NAME].isUInt());  // name id
+              GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+              std::string nameString = name.asString();
+
+              EXPECT_TRUE(marker[START_TIME].isNumeric());
+              EXPECT_TRUE(marker[END_TIME].isNumeric());
+              EXPECT_TRUE(marker[PHASE].isUInt());
+              EXPECT_TRUE(marker[PHASE].asUInt() < 4);
+              EXPECT_TRUE(marker[CATEGORY].isUInt());
+
+#  define EXPECT_TIMING_INSTANT                  \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#  define EXPECT_TIMING_INTERVAL                 \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#  define EXPECT_TIMING_START                    \
+    EXPECT_NE(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#  define EXPECT_TIMING_END                      \
+    EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+    EXPECT_NE(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+#  define EXPECT_TIMING_INSTANT_AT(t)            \
+    EXPECT_EQ(marker[START_TIME].asDouble(), t); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);   \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INSTANT);
+#  define EXPECT_TIMING_INTERVAL_AT(start, end)      \
+    EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), end);     \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_INTERVAL);
+#  define EXPECT_TIMING_START_AT(start)              \
+    EXPECT_EQ(marker[START_TIME].asDouble(), start); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), 0);       \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_START);
+#  define EXPECT_TIMING_END_AT(end)              \
+    EXPECT_EQ(marker[START_TIME].asDouble(), 0); \
+    EXPECT_EQ(marker[END_TIME].asDouble(), end); \
+    EXPECT_EQ(marker[PHASE].asUInt(), PHASE_END);
+
+              if (marker.size() == SIZE_WITHOUT_PAYLOAD) {
+                // root.threads[0].markers.data[i] is an array with 5 elements,
+                // so there is no payload.
+                if (nameString == "M1") {
+                  ASSERT_EQ(state, S_M1);
+                  state = State(state + 1);
+                } else if (nameString == "M3") {
+                  ASSERT_EQ(state, S_M3);
+                  state = State(state + 1);
+                } else if (nameString ==
+                           "default-templated markers 2.0 with empty options") {
+                  EXPECT_EQ(state, S_Markers2DefaultEmptyOptions);
+                  state = State(S_Markers2DefaultEmptyOptions + 1);
+// TODO: Re-enable this when bug 1646714 lands, and check for stack.
+#  if 0
+              } else if (nameString ==
+                         "default-templated markers 2.0 with option") {
+                EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                state = State(S_Markers2DefaultWithOptions + 1);
+#  endif
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "empty "
+                           "options") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultEmptyOptions);
+                  state = State(S_Markers2ExplicitDefaultEmptyOptions + 1);
+                } else if (nameString ==
+                           "explicitly-default-templated markers 2.0 with "
+                           "option") {
+                  EXPECT_EQ(state, S_Markers2ExplicitDefaultWithOptions);
+                  state = State(S_Markers2ExplicitDefaultWithOptions + 1);
+                }
+              } else {
+                // root.threads[0].markers.data[i] is an array with 6 elements,
+                // so there is a payload.
+                GET_JSON(payload, marker[PAYLOAD], Object);
+
+                // root.threads[0].markers.data[i][PAYLOAD] is an object
+                // (payload).
+
+                // It should at least have a "type" string.
+                GET_JSON(type, payload["type"], String);
+                std::string typeString = type.asString();
+
+                if (nameString == "tracing event") {
+                  EXPECT_EQ(state, S_tracing_event);
+                  state = State(S_tracing_event + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing start") {
+                  EXPECT_EQ(state, S_tracing_start);
+                  state = State(S_tracing_start + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_START;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing end") {
+                  EXPECT_EQ(state, S_tracing_end);
+                  state = State(S_tracing_end + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_END;
+                  EXPECT_EQ_JSON(payload["category"], String, "A");
+                  EXPECT_TRUE(payload["stack"].isNull());
+
+                } else if (nameString == "tracing event with stack") {
+                  EXPECT_EQ(state, S_tracing_event_with_stack);
+                  state = State(S_tracing_event_with_stack + 1);
+                  EXPECT_EQ(typeString, "tracing");
+                  EXPECT_TIMING_INSTANT;
+                  EXPECT_EQ_JSON(payload["category"], String, "B");
+                  EXPECT_TRUE(payload["stack"].isObject());
+
+                } else if (nameString == "auto tracing") {
+                  switch (state) {
+                    case S_tracing_auto_tracing_start:
+                      state = State(S_tracing_auto_tracing_start + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_START;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      EXPECT_TRUE(payload["stack"].isNull());
+                      break;
+                    case S_tracing_auto_tracing_end:
+                      state = State(S_tracing_auto_tracing_end + 1);
+                      EXPECT_EQ(typeString, "tracing");
+                      EXPECT_TIMING_END;
+                      EXPECT_EQ_JSON(payload["category"], String, "C");
+                      ASSERT_TRUE(payload["stack"].isNull());
+                      break;
+                    default:
+                      EXPECT_TRUE(state == S_tracing_auto_tracing_start ||
+                                  state == S_tracing_auto_tracing_end);
+                      break;
+                  }
+
+                } else if (nameString ==
+                           "default-templated markers 2.0 with option") {
+                  // TODO: Remove this when bug 1646714 lands.
+                  EXPECT_EQ(state, S_Markers2DefaultWithOptions);
+                  state = State(S_Markers2DefaultWithOptions + 1);
+                  EXPECT_EQ(typeString, "NoPayloadUserData");
+                  EXPECT_FALSE(payload["stack"].isNull());
+
+                } else if (nameString == "FirstMarker") {
+                  // Record start and end times, to compare with timestamps in
+                  // following markers.
+                  EXPECT_EQ(state, S_FirstMarker);
+                  ts1Double = marker[START_TIME].asDouble();
+                  ts2Double = marker[END_TIME].asDouble();
+                  state = State(S_FirstMarker + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_EQ_JSON(payload["name"], String, "First Marker");
+
+                } else if (nameString == "Gtest custom marker") {
+                  EXPECT_EQ(state, S_CustomMarker);
+                  state = State(S_CustomMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest");
+                  EXPECT_EQ(payload.size(), 1u + 9u);
+                  EXPECT_TRUE(payload["null"].isNull());
+                  EXPECT_EQ_JSON(payload["bool-false"], Bool, false);
+                  EXPECT_EQ_JSON(payload["bool-true"], Bool, true);
+                  EXPECT_EQ_JSON(payload["int"], Int64, 42);
+                  EXPECT_EQ_JSON(payload["double"], Double, 43.0);
+                  EXPECT_EQ_JSON(payload["text"], String, "gtest text");
+                  // Unique strings can be fetched from the string table.
+                  ASSERT_TRUE(payload["unique text"].isUInt());
+                  auto textIndex = payload["unique text"].asUInt();
+                  GET_JSON(uniqueText, stringTable[textIndex], String);
+                  ASSERT_TRUE(uniqueText.isString());
+                  ASSERT_EQ(uniqueText.asString(), "gtest unique text");
+                  // The duplicate unique text should have the exact same index.
+                  EXPECT_EQ_JSON(payload["unique text again"], UInt, textIndex);
+                  EXPECT_EQ_JSON(payload["time"], Double, ts1Double);
+
+                } else if (nameString == "Gtest special marker") {
+                  EXPECT_EQ(state, S_SpecialMarker);
+                  state = State(S_SpecialMarker + 1);
+                  EXPECT_EQ(typeString, "markers-gtest-special");
+                  EXPECT_EQ(payload.size(), 1u) << "Only 'type' in the payload";
+
+                } else if (nameString == "Load 1: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_start);
+                  state = State(S_NetworkMarkerPayload_start + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 1);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Hit");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 2: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_stop);
+                  state = State(S_NetworkMarkerPayload_stop + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 2);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_EQ_JSON(payload["contentType"], String, "text/html");
+
+                } else if (nameString == "Load 3: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_temporary);
+                  state = State(S_NetworkMarkerPayload_redirect_temporary + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 3);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Temporary");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 103);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 4: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_permanent);
+                  state = State(S_NetworkMarkerPayload_redirect_permanent + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 4);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Permanent");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 104);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 5: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_redirect_internal);
+                  state = State(S_NetworkMarkerPayload_redirect_internal + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 5);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Internal");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, false);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 105);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 6: http://mozilla.org/") {
+                  EXPECT_EQ(state,
+                            S_NetworkMarkerPayload_redirect_internal_sts);
+                  state =
+                      State(S_NetworkMarkerPayload_redirect_internal_sts + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 6);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_TRUE(payload["isPrivateBrowsing"].isNull());
+                  EXPECT_EQ_JSON(payload["RedirectURI"], String,
+                                 "http://example.com/");
+                  EXPECT_EQ_JSON(payload["redirectType"], String, "Internal");
+                  EXPECT_EQ_JSON(payload["isHttpToHttpsRedirect"], Bool, true);
+                  EXPECT_EQ_JSON(payload["redirectId"], Int64, 106);
+                  EXPECT_TRUE(payload["contentType"].isNull());
+
+                } else if (nameString == "Load 7: http://mozilla.org/") {
+                  EXPECT_EQ(state, S_NetworkMarkerPayload_private_browsing);
+                  state = State(S_NetworkMarkerPayload_private_browsing + 1);
+                  EXPECT_EQ(typeString, "Network");
+                  EXPECT_EQ_JSON(payload["startTime"], Double, ts1Double);
+                  EXPECT_EQ_JSON(payload["endTime"], Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["id"], Int64, 7);
+                  EXPECT_EQ_JSON(payload["URI"], String, "http://mozilla.org/");
+                  EXPECT_EQ_JSON(payload["requestMethod"], String, "GET");
+                  EXPECT_EQ_JSON(payload["pri"], Int64, 34);
+                  EXPECT_EQ_JSON(payload["count"], Int64, 56);
+                  EXPECT_EQ_JSON(payload["cache"], String, "Unresolved");
+                  EXPECT_EQ_JSON(payload["isPrivateBrowsing"], Bool, true);
+                  EXPECT_TRUE(payload["RedirectURI"].isNull());
+                  EXPECT_TRUE(payload["redirectType"].isNull());
+                  EXPECT_TRUE(payload["isHttpToHttpsRedirect"].isNull());
+                  EXPECT_TRUE(payload["redirectId"].isNull());
+                  EXPECT_TRUE(payload["contentType"].isNull());
+                } else if (nameString == "Text in main thread with stack") {
+                  EXPECT_EQ(state, S_TextWithStack);
+                  state = State(S_TextWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_TIMING_INTERVAL_AT(ts1Double, ts2Double);
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString == "Text from main thread with stack") {
+                  EXPECT_EQ(state, S_TextToMTWithStack);
+                  state = State(S_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in registered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in registered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from registered thread with stack") {
+                  EXPECT_EQ(state, S_RegThread_TextToMTWithStack);
+                  state = State(S_RegThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_FALSE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+
+                } else if (nameString ==
+                           "Text in unregistered thread with stack") {
+                  ADD_FAILURE()
+                      << "Unexpected 'Text in unregistered thread with stack'";
+
+                } else if (nameString ==
+                           "Text from unregistered thread with stack") {
+                  EXPECT_EQ(state, S_UnregThread_TextToMTWithStack);
+                  state = State(S_UnregThread_TextToMTWithStack + 1);
+                  EXPECT_EQ(typeString, "Text");
+                  EXPECT_TRUE(payload["stack"].isNull());
+                  EXPECT_EQ_JSON(payload["name"], String, "");
+                }
+              }  // marker with payload
+            }    // for (marker : data)
+          }      // markers.data
+        }        // markers
+      }          // thread0
+    }            // threads
+    // We should have read all expected markers.
+    EXPECT_EQ(state, S_LAST);
+
+    {
+      GET_JSON(meta, root["meta"], Object);
+
+      {
+        GET_JSON(markerSchema, meta["markerSchema"], Array);
+
+        std::set<std::string> testedSchemaNames;
+
+        for (const Json::Value& schema : markerSchema) {
+          GET_JSON(name, schema["name"], String);
+          const std::string nameString = name.asString();
+
+          GET_JSON(display, schema["display"], Array);
+
+          GET_JSON(data, schema["data"], Array);
+
+          EXPECT_TRUE(
+              testedSchemaNames
+                  .insert(std::string(nameString.data(), nameString.size()))
+                  .second)
+              << "Each schema name should be unique (inserted once in the set)";
+
+          if (nameString == "Text") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Details");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "NoPayloadUserData") {
+            // TODO: Remove this when bug 1646714 lands.
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "FileIO") {
+            // These are defined in ProfilerIOInterposeObserver.cpp
+
+          } else if (nameString == "tracing") {
+            EXPECT_EQ(display.size(), 3u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "BHR-detected hang") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "MainThreadLongTask") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 1u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "category");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Type");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+          } else if (nameString == "Log") {
+            EXPECT_EQ(display.size(), 1u);
+            EXPECT_EQ(display[0u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "module");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Module");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "string");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "name");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Name");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "string");
+
+          } else if (nameString == "MediaSample") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 3u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "sampleStartTimeUs");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Sample start time");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "sampleEndTimeUs");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Sample end time");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[2u].isObject());
+            EXPECT_EQ_JSON(data[2u]["key"], String, "queueLength");
+            EXPECT_EQ_JSON(data[2u]["label"], String, "Queue length");
+            EXPECT_EQ_JSON(data[2u]["format"], String, "integer");
+
+          } else if (nameString == "VideoFallingBehind") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 2u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "videoFrameStartTimeUs");
+            EXPECT_EQ_JSON(data[0u]["label"], String, "Video frame start time");
+            EXPECT_EQ_JSON(data[0u]["format"], String, "microseconds");
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "mediaCurrentTimeUs");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "Media current time");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "microseconds");
+
+          } else if (nameString == "Budget") {
+            EXPECT_EQ(display.size(), 2u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest") {
+            EXPECT_EQ(display.size(), 7u);
+            EXPECT_EQ(display[0u].asString(), "marker-chart");
+            EXPECT_EQ(display[1u].asString(), "marker-table");
+            EXPECT_EQ(display[2u].asString(), "timeline-overview");
+            EXPECT_EQ(display[3u].asString(), "timeline-memory");
+            EXPECT_EQ(display[4u].asString(), "timeline-ipc");
+            EXPECT_EQ(display[5u].asString(), "timeline-fileio");
+            EXPECT_EQ(display[6u].asString(), "stack-chart");
+
+            EXPECT_EQ_JSON(schema["chartLabel"], String, "chart label");
+            EXPECT_EQ_JSON(schema["tooltipLabel"], String, "tooltip label");
+            EXPECT_EQ_JSON(schema["tableLabel"], String, "table label");
+
+            ASSERT_EQ(data.size(), 14u);
+
+            ASSERT_TRUE(data[0u].isObject());
+            EXPECT_EQ_JSON(data[0u]["key"], String, "key with url");
+            EXPECT_TRUE(data[0u]["label"].isNull());
+            EXPECT_EQ_JSON(data[0u]["format"], String, "url");
+            EXPECT_TRUE(data[0u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[1u].isObject());
+            EXPECT_EQ_JSON(data[1u]["key"], String, "key with label filePath");
+            EXPECT_EQ_JSON(data[1u]["label"], String, "label filePath");
+            EXPECT_EQ_JSON(data[1u]["format"], String, "file-path");
+            EXPECT_TRUE(data[1u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[2u].isObject());
+            EXPECT_EQ_JSON(data[2u]["key"], String,
+                           "key with string not-searchable");
+            EXPECT_TRUE(data[2u]["label"].isNull());
+            EXPECT_EQ_JSON(data[2u]["format"], String, "string");
+            EXPECT_EQ_JSON(data[2u]["searchable"], Bool, false);
+
+            ASSERT_TRUE(data[3u].isObject());
+            EXPECT_EQ_JSON(data[3u]["key"], String,
+                           "key with label duration searchable");
+            EXPECT_TRUE(data[3u]["label duration"].isNull());
+            EXPECT_EQ_JSON(data[3u]["format"], String, "duration");
+            EXPECT_EQ_JSON(data[3u]["searchable"], Bool, true);
+
+            ASSERT_TRUE(data[4u].isObject());
+            EXPECT_EQ_JSON(data[4u]["key"], String, "key with time");
+            EXPECT_TRUE(data[4u]["label"].isNull());
+            EXPECT_EQ_JSON(data[4u]["format"], String, "time");
+            EXPECT_TRUE(data[4u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[5u].isObject());
+            EXPECT_EQ_JSON(data[5u]["key"], String, "key with seconds");
+            EXPECT_TRUE(data[5u]["label"].isNull());
+            EXPECT_EQ_JSON(data[5u]["format"], String, "seconds");
+            EXPECT_TRUE(data[5u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[6u].isObject());
+            EXPECT_EQ_JSON(data[6u]["key"], String, "key with milliseconds");
+            EXPECT_TRUE(data[6u]["label"].isNull());
+            EXPECT_EQ_JSON(data[6u]["format"], String, "milliseconds");
+            EXPECT_TRUE(data[6u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[7u].isObject());
+            EXPECT_EQ_JSON(data[7u]["key"], String, "key with microseconds");
+            EXPECT_TRUE(data[7u]["label"].isNull());
+            EXPECT_EQ_JSON(data[7u]["format"], String, "microseconds");
+            EXPECT_TRUE(data[7u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[8u].isObject());
+            EXPECT_EQ_JSON(data[8u]["key"], String, "key with nanoseconds");
+            EXPECT_TRUE(data[8u]["label"].isNull());
+            EXPECT_EQ_JSON(data[8u]["format"], String, "nanoseconds");
+            EXPECT_TRUE(data[8u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[9u].isObject());
+            EXPECT_EQ_JSON(data[9u]["key"], String, "key with bytes");
+            EXPECT_TRUE(data[9u]["label"].isNull());
+            EXPECT_EQ_JSON(data[9u]["format"], String, "bytes");
+            EXPECT_TRUE(data[9u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[10u].isObject());
+            EXPECT_EQ_JSON(data[10u]["key"], String, "key with percentage");
+            EXPECT_TRUE(data[10u]["label"].isNull());
+            EXPECT_EQ_JSON(data[10u]["format"], String, "percentage");
+            EXPECT_TRUE(data[10u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[11u].isObject());
+            EXPECT_EQ_JSON(data[11u]["key"], String, "key with integer");
+            EXPECT_TRUE(data[11u]["label"].isNull());
+            EXPECT_EQ_JSON(data[11u]["format"], String, "integer");
+            EXPECT_TRUE(data[11u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[12u].isObject());
+            EXPECT_EQ_JSON(data[12u]["key"], String, "key with decimal");
+            EXPECT_TRUE(data[12u]["label"].isNull());
+            EXPECT_EQ_JSON(data[12u]["format"], String, "decimal");
+            EXPECT_TRUE(data[12u]["searchable"].isNull());
+
+            ASSERT_TRUE(data[13u].isObject());
+            EXPECT_EQ_JSON(data[13u]["label"], String, "static label");
+            EXPECT_EQ_JSON(data[13u]["value"], String, "static value");
+
+          } else if (nameString == "markers-gtest-special") {
+            EXPECT_EQ(display.size(), 0u);
+            ASSERT_EQ(data.size(), 0u);
+
+          } else if (nameString == "markers-gtest-unused") {
+            ADD_FAILURE() << "Schema for GtestUnusedMarker should not be here";
+
+          } else {
+            printf("FYI: Unknown marker schema '%s'\n", nameString.c_str());
+          }
+        }
+
+        // Check that we've got all expected schema.
+        EXPECT_TRUE(testedSchemaNames.find("Text") != testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("tracing") !=
+                    testedSchemaNames.end());
+        EXPECT_TRUE(testedSchemaNames.find("MediaSample") !=
+                    testedSchemaNames.end());
+      }  // markerSchema
+    }    // meta
+  });
+
+  Maybe<ProfilerBufferInfo> info = profiler_get_buffer_info();
+  EXPECT_TRUE(info.isSome());
+  printf("Profiler buffer range: %llu .. %llu (%llu bytes)\n",
+         static_cast<unsigned long long>(info->mRangeStart),
+         static_cast<unsigned long long>(info->mRangeEnd),
+         // sizeof(ProfileBufferEntry) == 9
+         (static_cast<unsigned long long>(info->mRangeEnd) -
+          static_cast<unsigned long long>(info->mRangeStart)) *
+             9);
+  printf("Stats:         min(us) .. mean(us) .. max(us)  [count]\n");
+  printf("- Intervals:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mIntervalsUs.min, info->mIntervalsUs.sum / info->mIntervalsUs.n,
+         info->mIntervalsUs.max, info->mIntervalsUs.n);
+  printf("- Overheads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mOverheadsUs.min, info->mOverheadsUs.sum / info->mOverheadsUs.n,
+         info->mOverheadsUs.max, info->mOverheadsUs.n);
+  printf("  - Locking:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mLockingsUs.min, info->mLockingsUs.sum / info->mLockingsUs.n,
+         info->mLockingsUs.max, info->mLockingsUs.n);
+  printf("  - Clearning: %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCleaningsUs.min, info->mCleaningsUs.sum / info->mCleaningsUs.n,
+         info->mCleaningsUs.max, info->mCleaningsUs.n);
+  printf("  - Counters:  %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mCountersUs.min, info->mCountersUs.sum / info->mCountersUs.n,
+         info->mCountersUs.max, info->mCountersUs.n);
+  printf("  - Threads:   %7.1f .. %7.1f  .. %7.1f  [%u]\n",
+         info->mThreadsUs.min, info->mThreadsUs.sum / info->mThreadsUs.n,
+         info->mThreadsUs.max, info->mThreadsUs.n);
+
+  profiler_stop();
+
+  // Try to add markers while the profiler is stopped.
+  PROFILER_MARKER_UNTYPED("marker after profiler_stop", OTHER);
+
+  // Warning: this could be racy
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // This last marker shouldn't get streamed.
+  SpliceableChunkedJSONWriter w2{FailureLatchInfallibleSource::Singleton()};
+  w2.Start();
+  EXPECT_TRUE(::profiler_stream_json_for_this_process(w2).isOk());
+  w2.End();
+  EXPECT_FALSE(w2.Failed());
+  UniquePtr<char[]> profile2 = w2.ChunkedWriteFunc().CopyData();
+  ASSERT_TRUE(!!profile2.get());
+  EXPECT_TRUE(
+      std::string_view(profile2.get()).find("marker after profiler_stop") ==
+      std::string_view::npos);
+
+  profiler_stop();
+}
+
+#  define COUNTER_NAME "TestCounter"
+#  define COUNTER_DESCRIPTION "Test of counters in profiles"
+#  define COUNTER_NAME2 "Counter2"
+#  define COUNTER_DESCRIPTION2 "Second Test of counters in profiles"
+
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter, COUNTER_NAME, COUNTER_DESCRIPTION);
+PROFILER_DEFINE_COUNT_TOTAL(TestCounter2, COUNTER_NAME2, COUNTER_DESCRIPTION2);
+
+TEST(GeckoProfiler, Counters)
+{
+  uint32_t features = 0;
+  const char* filters[] = {"GeckoMain"};
+
+  // We will record some counter values, and check that they're present (and no
+  // other) when expected.
+
+  struct NumberAndCount {
+    uint64_t mNumber;
+    int64_t mCount;
+  };
+
+  int64_t testCounters[] = {10, 7, -17};
+  NumberAndCount expectedTestCounters[] = {{1u, 10}, {0u, 0}, {1u, 7},
+                                           {0u, 0},  {0u, 0}, {1u, -17},
+                                           {0u, 0},  {0u, 0}};
+  constexpr size_t expectedTestCountersCount =
+      MOZ_ARRAY_LENGTH(expectedTestCounters);
+
+  bool expectCounter2 = false;
+  int64_t testCounters2[] = {10};
+  NumberAndCount expectedTestCounters2[] = {{1u, 10}, {0u, 0}};
+  constexpr size_t expectedTestCounters2Count =
+      MOZ_ARRAY_LENGTH(expectedTestCounters2);
+
+  auto checkCountersInJSON = [&](const Json::Value& aRoot) {
+    size_t nextExpectedTestCounter = 0u;
+    size_t nextExpectedTestCounter2 = 0u;
+
+    GET_JSON(counters, aRoot["counters"], Array);
+    for (const Json::Value& counter : counters) {
+      ASSERT_TRUE(counter.isObject());
+      GET_JSON_VALUE(name, counter["name"], String);
+      if (name == "TestCounter") {
+        EXPECT_EQ_JSON(counter["category"], String, COUNTER_NAME);
+        EXPECT_EQ_JSON(counter["description"], String, COUNTER_DESCRIPTION);
+        GET_JSON(sampleGroups, counter["sample_groups"], Array);
+        for (const Json::Value& sampleGroup : sampleGroups) {
+          ASSERT_TRUE(sampleGroup.isObject());
+          EXPECT_EQ_JSON(sampleGroup["id"], UInt, 0u);
+
+          GET_JSON(samples, sampleGroup["samples"], Object);
+          GET_JSON(samplesSchema, samples["schema"], Object);
+          EXPECT_GE(samplesSchema.size(), 3u);
+          GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+          GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+          GET_JSON(samplesData, samples["data"], Array);
+          for (const Json::Value& sample : samplesData) {
+            ASSERT_TRUE(sample.isArray());
+            ASSERT_LT(nextExpectedTestCounter, expectedTestCountersCount);
+            EXPECT_EQ_JSON(
+                sample[samplesNumber], UInt64,
+                expectedTestCounters[nextExpectedTestCounter].mNumber);
+            EXPECT_EQ_JSON(
+                sample[samplesCount], Int64,
+                expectedTestCounters[nextExpectedTestCounter].mCount);
+            ++nextExpectedTestCounter;
+          }
+        }
+      } else if (name == "TestCounter2") {
+        EXPECT_TRUE(expectCounter2);
+
+        EXPECT_EQ_JSON(counter["category"], String, COUNTER_NAME2);
+        EXPECT_EQ_JSON(counter["description"], String, COUNTER_DESCRIPTION2);
+        GET_JSON(sampleGroups, counter["sample_groups"], Array);
+        for (const Json::Value& sampleGroup : sampleGroups) {
+          ASSERT_TRUE(sampleGroup.isObject());
+          EXPECT_EQ_JSON(sampleGroup["id"], UInt, 0u);
+
+          GET_JSON(samples, sampleGroup["samples"], Object);
+          GET_JSON(samplesSchema, samples["schema"], Object);
+          EXPECT_GE(samplesSchema.size(), 3u);
+          GET_JSON_VALUE(samplesNumber, samplesSchema["number"], UInt);
+          GET_JSON_VALUE(samplesCount, samplesSchema["count"], UInt);
+          GET_JSON(samplesData, samples["data"], Array);
+          for (const Json::Value& sample : samplesData) {
+            ASSERT_TRUE(sample.isArray());
+            ASSERT_LT(nextExpectedTestCounter2, expectedTestCounters2Count);
+            EXPECT_EQ_JSON(
+                sample[samplesNumber], UInt64,
+                expectedTestCounters2[nextExpectedTestCounter2].mNumber);
+            EXPECT_EQ_JSON(
+                sample[samplesCount], Int64,
+                expectedTestCounters2[nextExpectedTestCounter2].mCount);
+            ++nextExpectedTestCounter2;
+          }
+        }
+      }
+    }
+
+    EXPECT_EQ(nextExpectedTestCounter, expectedTestCountersCount);
+    if (expectCounter2) {
+      EXPECT_EQ(nextExpectedTestCounter2, expectedTestCounters2Count);
+    }
+  };
+
+  // Inactive -> Active
+  profiler_ensure_started(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                          features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Output all "TestCounter"s, with increasing delays (to test different
+  // number of counter samplings).
+  int samplingWaits = 2;
+  for (int64_t counter : testCounters) {
+    AUTO_PROFILER_COUNT_TOTAL(TestCounter, counter);
+    for (int i = 0; i < samplingWaits; ++i) {
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+    ++samplingWaits;
+  }
+
+  // Verify we got "TestCounter" in the output, but not "TestCounter2" yet.
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), checkCountersInJSON);
+
+  // Now introduce TestCounter2.
+  expectCounter2 = true;
+  for (int64_t counter2 : testCounters2) {
+    AUTO_PROFILER_COUNT_TOTAL(TestCounter2, counter2);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+
+  // Verify we got both "TestCounter" and "TestCounter2" in the output.
+  profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), checkCountersInJSON);
+
+  profiler_stop();
+}
+
+TEST(GeckoProfiler, Time)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  double t1 = profiler_time();
+  double t2 = profiler_time();
+  ASSERT_TRUE(t1 <= t2);
+
+  // profiler_start() restarts the timer used by profiler_time().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  double t3 = profiler_time();
+  double t4 = profiler_time();
+  ASSERT_TRUE(t3 <= t4);
+
+  profiler_stop();
+
+  double t5 = profiler_time();
+  double t6 = profiler_time();
+  ASSERT_TRUE(t4 <= t5 && t1 <= t6);
+}
+
+TEST(GeckoProfiler, GetProfile)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_get_profile());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  mozilla::Maybe<uint32_t> activeFeatures = profiler_features_if_active();
+  ASSERT_TRUE(activeFeatures.isSome());
+  // Not all platforms support stack-walking.
+  const bool hasStackWalk = ProfilerFeature::HasStackWalk(*activeFeatures);
+
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+    GET_JSON(meta, aRoot["meta"], Object);
+    {
+      GET_JSON(configuration, meta["configuration"], Object);
+      {
+        GET_JSON(features, configuration["features"], Array);
+        {
+          EXPECT_EQ(features.size(), (hasStackWalk ? 1u : 0u));
+          if (hasStackWalk) {
+            EXPECT_JSON_ARRAY_CONTAINS(features, String, "stackwalk");
+          }
+        }
+        GET_JSON(threads, configuration["threads"], Array);
+        {
+          EXPECT_EQ(threads.size(), 1u);
+          EXPECT_JSON_ARRAY_CONTAINS(threads, String, "GeckoMain");
+        }
+      }
+    }
+  });
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, StreamJSONForThisProcess)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Fallible());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(&w.ChunkedWriteFunc().SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(
+      &std::as_const(w.ChunkedWriteFunc()).SourceFailureLatch() ==
+      &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(!w.Fallible());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+  MOZ_RELEASE_ASSERT(&w.SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(&std::as_const(w).SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w).isErr());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  w.Start();
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w).isOk());
+  w.End();
+
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  profiler_stop();
+
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w).isErr());
+}
+
+// Internal version of profiler_stream_json_for_this_process, which allows being
+// called from a non-main thread of the parent process, at the risk of getting
+// an incomplete profile.
+ProfilerResult<ProfileGenerationAdditionalInformation>
+do_profiler_stream_json_for_this_process(
+    SpliceableJSONWriter& aWriter, double aSinceTime, bool aIsShuttingDown,
+    ProfilerCodeAddressService* aService,
+    mozilla::ProgressLogger aProgressLogger);
+
+TEST(GeckoProfiler, StreamJSONForThisProcessThreaded)
+{
+  // Same as the previous test, but calling some things on background threads.
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  SpliceableChunkedJSONWriter w{FailureLatchInfallibleSource::Singleton()};
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Fallible());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(&w.ChunkedWriteFunc().SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(
+      &std::as_const(w.ChunkedWriteFunc()).SourceFailureLatch() ==
+      &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(!w.Fallible());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+  MOZ_RELEASE_ASSERT(&w.SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+  MOZ_RELEASE_ASSERT(&std::as_const(w).SourceFailureLatch() ==
+                     &mozilla::FailureLatchInfallibleSource::Singleton());
+
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w).isErr());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  // Start the profiler on the main thread.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Call profiler_stream_json_for_this_process on a background thread.
+  NS_DispatchAndSpinEventLoopUntilComplete(
+      "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody"_ns,
+      thread,
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            w.Start();
+            ASSERT_TRUE(::do_profiler_stream_json_for_this_process(
+                            w, /* double aSinceTime */ 0.0,
+                            /* bool aIsShuttingDown */ false,
+                            /* ProfilerCodeAddressService* aService */ nullptr,
+                            mozilla::ProgressLogger{})
+                            .isOk());
+            w.End();
+          }));
+
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().Failed());
+  MOZ_RELEASE_ASSERT(!w.ChunkedWriteFunc().GetFailure());
+  MOZ_RELEASE_ASSERT(!w.Failed());
+  MOZ_RELEASE_ASSERT(!w.GetFailure());
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+
+  JSONOutputCheck(profile.get(), [](const Json::Value&) {});
+
+  // Stop the profiler and call profiler_stream_json_for_this_process on a
+  // background thread.
+  NS_DispatchAndSpinEventLoopUntilComplete(
+      "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody"_ns,
+      thread,
+      NS_NewRunnableFunction(
+          "GeckoProfiler_StreamJSONForThisProcessThreaded_Test::TestBody",
+          [&]() {
+            profiler_stop();
+            ASSERT_TRUE(::do_profiler_stream_json_for_this_process(
+                            w, /* double aSinceTime */ 0.0,
+                            /* bool aIsShuttingDown */ false,
+                            /* ProfilerCodeAddressService* aService */ nullptr,
+                            mozilla::ProgressLogger{})
+                            .isErr());
+          }));
+  thread->Shutdown();
+
+  // Call profiler_stream_json_for_this_process on the main thread.
+  ASSERT_TRUE(::profiler_stream_json_for_this_process(w).isErr());
+}
+
+TEST(GeckoProfiler, ProfilingStack)
+{
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+
+  AUTO_PROFILER_LABEL("A::B", OTHER);
+
+  UniqueFreePtr<char> dynamic(strdup("dynamic"));
+  {
+    AUTO_PROFILER_LABEL_DYNAMIC_CSTR("A::C", JS, dynamic.get());
+    AUTO_PROFILER_LABEL_DYNAMIC_NSCSTRING("A::C2", JS,
+                                          nsDependentCString(dynamic.get()));
+    AUTO_PROFILER_LABEL_DYNAMIC_LOSSY_NSSTRING(
+        "A::C3", JS, NS_ConvertUTF8toUTF16(dynamic.get()));
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_get_backtrace());
+  }
+
+  AutoProfilerLabel label1("A", nullptr, JS::ProfilingCategoryPair::DOM);
+  AutoProfilerLabel label2("A", dynamic.get(),
+                           JS::ProfilingCategoryPair::NETWORK);
+  ASSERT_TRUE(profiler_get_backtrace());
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+TEST(GeckoProfiler, Bug1355807)
+{
+  uint32_t features = ProfilerFeature::JS;
+  const char* manyThreadsFilter[] = {""};
+  const char* fewThreadsFilter[] = {"GeckoMain"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 manyThreadsFilter, MOZ_ARRAY_LENGTH(manyThreadsFilter), 0);
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  // In bug 1355807 this caused an assertion failure in StopJSSampling().
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 fewThreadsFilter, MOZ_ARRAY_LENGTH(fewThreadsFilter), 0);
+
+  profiler_stop();
+}
+
+class GTestStackCollector final : public ProfilerStackCollector {
+ public:
+  GTestStackCollector() : mSetIsMainThread(0), mFrames(0) {}
+
+  virtual void SetIsMainThread() { mSetIsMainThread++; }
+
+  virtual void CollectNativeLeafAddr(void* aAddr) { mFrames++; }
+  virtual void CollectJitReturnAddr(void* aAddr) { mFrames++; }
+  virtual void CollectWasmFrame(const char* aLabel) { mFrames++; }
+  virtual void CollectProfilingStackFrame(
+      const js::ProfilingStackFrame& aFrame) {
+    mFrames++;
+  }
+
+  int mSetIsMainThread;
+  int mFrames;
+};
+
+void DoSuspendAndSample(ProfilerThreadId aTidToSample,
+                        nsIThread* aSamplingThread) {
+  NS_DispatchAndSpinEventLoopUntilComplete(
+      "GeckoProfiler_SuspendAndSample_Test::TestBody"_ns, aSamplingThread,
+      NS_NewRunnableFunction(
+          "GeckoProfiler_SuspendAndSample_Test::TestBody", [&]() {
+            uint32_t features = ProfilerFeature::CPUUtilization;
+            GTestStackCollector collector;
+            profiler_suspend_and_sample_thread(aTidToSample, features,
+                                               collector,
+                                               /* sampleNative = */ true);
+
+            ASSERT_TRUE(collector.mSetIsMainThread ==
+                        (aTidToSample == profiler_main_thread_id()));
+            ASSERT_TRUE(collector.mFrames > 0);
+          }));
+}
+
+TEST(GeckoProfiler, SuspendAndSample)
+{
+  nsCOMPtr<nsIThread> thread;
+  nsresult rv = NS_NewNamedThread("GeckoProfGTest", getter_AddRefs(thread));
+  ASSERT_NS_SUCCEEDED(rv);
+
+  ProfilerThreadId tid = profiler_current_thread_id();
+
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Suspend and sample while the profiler is inactive.
+  DoSuspendAndSample(tid, thread);
+
+  DoSuspendAndSample(ProfilerThreadId{}, thread);
+
+  uint32_t features = ProfilerFeature::JS;
+  const char* filters[] = {"GeckoMain", "Compositor"};
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_TRUE(profiler_is_active());
+
+  // Suspend and sample while the profiler is active.
+  DoSuspendAndSample(tid, thread);
+
+  DoSuspendAndSample(ProfilerThreadId{}, thread);
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_is_active());
+}
+
+TEST(GeckoProfiler, PostSamplingCallback)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileCompleted = profiler_get_profile();
+  JSONOutputCheck(profileCompleted.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback completed");
+      }
+    }
+  });
+
+  profiler_pause();
+  {
+    // Paused -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback paused", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingPaused);
+  }
+  UniquePtr<char[]> profilePaused = profiler_get_profile();
+  JSONOutputCheck(profilePaused.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profilePaused.get(), "PostSamplingCallback paused"));
+
+  profiler_resume();
+  {
+    // Stack sampling -> This label should appear at least once.
+    AUTO_PROFILER_LABEL("PostSamplingCallback resumed", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  }
+  UniquePtr<char[]> profileResumed = profiler_get_profile();
+  JSONOutputCheck(profileResumed.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      GET_JSON(thread0, threads[0], Object);
+      {
+        EXPECT_JSON_ARRAY_CONTAINS(thread0["stringTable"], String,
+                                   "PostSamplingCallback resumed");
+      }
+    }
+  });
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::NoStackSampling,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  {
+    // No stack sampling -> This label should not appear.
+    AUTO_PROFILER_LABEL("PostSamplingCallback completed (no stacks)", OTHER);
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::NoStackSamplingCompleted);
+  }
+  UniquePtr<char[]> profileNoStacks = profiler_get_profile();
+  JSONOutputCheck(profileNoStacks.get(), [](const Json::Value& aRoot) {});
+  // This string shouldn't appear *anywhere* in the profile.
+  ASSERT_FALSE(strstr(profileNoStacks.get(),
+                      "PostSamplingCallback completed (no stacks)"));
+
+  // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+  // it would require coordination between `profiler_stop()` and another thread
+  // doing `profiler_callback_after_sampling()` at just the right moment.
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+  ASSERT_TRUE(!profiler_callback_after_sampling(
+      [&](SamplingState) { ASSERT_TRUE(false); }));
+}
+
+TEST(GeckoProfiler, ProfilingStateCallback)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_is_active());
+
+  struct ProfilingStateAndId {
+    ProfilingState mProfilingState;
+    int mId;
+  };
+  DataMutex<Vector<ProfilingStateAndId>> states{"Profiling states"};
+  auto CreateCallback = [&states](int id) {
+    return [id, &states](ProfilingState aProfilingState) {
+      auto lockedStates = states.Lock();
+      ASSERT_TRUE(
+          lockedStates->append(ProfilingStateAndId{aProfilingState, id}));
+    };
+  };
+  auto CheckStatesIsEmpty = [&states]() {
+    auto lockedStates = states.Lock();
+    EXPECT_TRUE(lockedStates->empty());
+  };
+  auto CheckStatesOnlyContains = [&states](ProfilingState aProfilingState,
+                                           int aId) {
+    auto lockedStates = states.Lock();
+    EXPECT_EQ(lockedStates->length(), 1u);
+    if (lockedStates->length() >= 1u) {
+      EXPECT_EQ((*lockedStates)[0].mProfilingState, aProfilingState);
+      EXPECT_EQ((*lockedStates)[0].mId, aId);
+    }
+    lockedStates->clear();
+  };
+
+  profiler_add_state_change_callback(AllProfilingStates(), CreateCallback(1),
+                                     1);
+  // This is in case of error, and it also exercises the (allowed) removal of
+  // unknown callback ids.
+  auto cleanup1 = mozilla::MakeScopeExit(
+      []() { profiler_remove_state_change_callback(1); });
+  CheckStatesIsEmpty();
+
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+
+  CheckStatesOnlyContains(ProfilingState::Started, 1);
+
+  profiler_add_state_change_callback(AllProfilingStates(), CreateCallback(2),
+                                     2);
+  // This is in case of error, and it also exercises the (allowed) removal of
+  // unknown callback ids.
+  auto cleanup2 = mozilla::MakeScopeExit(
+      []() { profiler_remove_state_change_callback(2); });
+  CheckStatesOnlyContains(ProfilingState::AlreadyActive, 2);
+
+  profiler_remove_state_change_callback(2);
+  CheckStatesOnlyContains(ProfilingState::RemovingCallback, 2);
+  // Note: The actual removal is effectively tested below, by not seeing any
+  // more invocations of the 2nd callback.
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  UniquePtr<char[]> profileCompleted = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileCompleted.get(), [](const Json::Value& aRoot) {});
+
+  profiler_pause();
+  CheckStatesOnlyContains(ProfilingState::Pausing, 1);
+  UniquePtr<char[]> profilePaused = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profilePaused.get(), [](const Json::Value& aRoot) {});
+
+  profiler_resume();
+  CheckStatesOnlyContains(ProfilingState::Resumed, 1);
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  UniquePtr<char[]> profileResumed = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileResumed.get(), [](const Json::Value& aRoot) {});
+
+  // This effectively stops the profiler before restarting it, but
+  // ProfilingState::Stopping is not notified. See `profiler_start` for details.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk | ProfilerFeature::NoStackSampling,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+  CheckStatesOnlyContains(ProfilingState::Started, 1);
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::NoStackSamplingCompleted);
+  UniquePtr<char[]> profileNoStacks = profiler_get_profile();
+  CheckStatesOnlyContains(ProfilingState::GeneratingProfile, 1);
+  JSONOutputCheck(profileNoStacks.get(), [](const Json::Value& aRoot) {});
+
+  profiler_stop();
+  CheckStatesOnlyContains(ProfilingState::Stopping, 1);
+  ASSERT_TRUE(!profiler_is_active());
+
+  profiler_remove_state_change_callback(1);
+  CheckStatesOnlyContains(ProfilingState::RemovingCallback, 1);
+
+  // Note: ProfilingState::ShuttingDown cannot be tested here, and the profiler
+  // can only be shut down once per process.
+}
+
+TEST(GeckoProfiler, BaseProfilerHandOff)
+{
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker before base profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker before base profiler", OTHER, {});
+
+  // Start the Base Profiler.
+  baseprofiler::profiler_start(
+      PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+      ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters));
+
+  ASSERT_TRUE(baseprofiler::profiler_is_active());
+  ASSERT_TRUE(!profiler_is_active());
+
+  // Add at least a marker, which should go straight into the buffer.
+  Maybe<baseprofiler::ProfilerBufferInfo> info0 =
+      baseprofiler::profiler_get_buffer_info();
+  BASE_PROFILER_MARKER_UNTYPED("Base marker during base profiler", OTHER, {});
+  Maybe<baseprofiler::ProfilerBufferInfo> info1 =
+      baseprofiler::profiler_get_buffer_info();
+  ASSERT_GT(info1->mRangeEnd, info0->mRangeEnd);
+
+  PROFILER_MARKER_UNTYPED("Gecko marker during base profiler", OTHER, {});
+
+  // Start the Gecko Profiler, which should grab the Base Profiler profile and
+  // stop it.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                 ProfilerFeature::StackWalk, filters, MOZ_ARRAY_LENGTH(filters),
+                 0);
+
+  ASSERT_TRUE(!baseprofiler::profiler_is_active());
+  ASSERT_TRUE(profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker during gecko profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker during gecko profiler", OTHER, {});
+
+  // Write some Gecko Profiler samples.
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+  // Check that the Gecko Profiler profile contains at least the Base Profiler
+  // main thread samples.
+  UniquePtr<char[]> profile = profiler_get_profile();
+
+  profiler_stop();
+  ASSERT_TRUE(!profiler_is_active());
+
+  BASE_PROFILER_MARKER_UNTYPED("Base marker after gecko profiler", OTHER, {});
+  PROFILER_MARKER_UNTYPED("Gecko marker after gecko profiler", OTHER, {});
+
+  JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      bool found = false;
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          found = true;
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Base marker before base profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker before base profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Base marker during base profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker during base profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Base marker during gecko profiler");
+          EXPECT_JSON_ARRAY_CONTAINS(thread["stringTable"], String,
+                                     "Gecko marker during gecko profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Base marker after gecko profiler");
+          EXPECT_JSON_ARRAY_EXCLUDES(thread["stringTable"], String,
+                                     "Gecko marker after gecko profiler");
+          break;
+        }
+      }
+      EXPECT_TRUE(found);
+    }
+  });
+}
+
+static std::string_view GetFeatureName(uint32_t feature) {
+  switch (feature) {
+#  define FEATURE_NAME(n_, str_, Name_, desc_) \
+    case ProfilerFeature::Name_:               \
+      return str_;
+
+    PROFILER_FOR_EACH_FEATURE(FEATURE_NAME)
+
+#  undef FEATURE_NAME
+
+    default:
+      return "?";
+  }
+}
+
+TEST(GeckoProfiler, FeatureCombinations)
+{
+  // Bug 1845606
+  #ifdef XP_WIN
+  if (!IsWin8OrLater()) {
+    return;
+  }
+  #endif
+
+  const char* filters[] = {"*"};
+
+  // List of features to test. Every combination of up to 3 of them will be
+  // tested, so be careful not to add too many to keep the test run at a
+  // reasonable time.
+  uint32_t featureList[] = {ProfilerFeature::JS,
+                            ProfilerFeature::Screenshots,
+                            ProfilerFeature::StackWalk,
+                            ProfilerFeature::NoStackSampling,
+                            ProfilerFeature::NativeAllocations,
+                            ProfilerFeature::CPUUtilization,
+                            ProfilerFeature::CPUAllThreads,
+                            ProfilerFeature::SamplingAllThreads,
+                            ProfilerFeature::MarkersAllThreads,
+                            ProfilerFeature::UnregisteredThreads};
+  constexpr uint32_t featureCount = uint32_t(MOZ_ARRAY_LENGTH(featureList));
+
+  auto testFeatures = [&](uint32_t features,
+                          const std::string& featuresString) {
+    SCOPED_TRACE(featuresString.c_str());
+
+    ASSERT_TRUE(!profiler_is_active());
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_is_active());
+
+    // Write some Gecko Profiler samples.
+    EXPECT_EQ(WaitForSamplingState(),
+              (((features & ProfilerFeature::NoStackSampling) != 0) &&
+               ((features & (ProfilerFeature::CPUUtilization |
+                             ProfilerFeature::CPUAllThreads)) == 0))
+                  ? SamplingState::NoStackSamplingCompleted
+                  : SamplingState::SamplingCompleted);
+
+    // Check that the profile looks valid. Note that we don't test feature-
+    // specific changes.
+    UniquePtr<char[]> profile = profiler_get_profile();
+    JSONOutputCheck(profile.get(), [](const Json::Value& aRoot) {});
+
+    profiler_stop();
+    ASSERT_TRUE(!profiler_is_active());
+  };
+
+  testFeatures(0, "Features: (none)");
+
+  for (uint32_t f1 = 0u; f1 < featureCount; ++f1) {
+    const uint32_t features1 = featureList[f1];
+    std::string features1String = "Features: ";
+    features1String += GetFeatureName(featureList[f1]);
+
+    testFeatures(features1, features1String);
+
+    for (uint32_t f2 = f1 + 1u; f2 < featureCount; ++f2) {
+      const uint32_t features12 = f1 | featureList[f2];
+      std::string features12String = features1String + " ";
+      features12String += GetFeatureName(featureList[f2]);
+
+      testFeatures(features12, features12String);
+
+      for (uint32_t f3 = f2 + 1u; f3 < featureCount; ++f3) {
+        const uint32_t features123 = features12 | featureList[f3];
+        std::string features123String = features12String + " ";
+        features123String += GetFeatureName(featureList[f3]);
+
+        testFeatures(features123, features123String);
+      }
+    }
+  }
+}
+
+static void CountCPUDeltas(const Json::Value& aThread, size_t& aOutSamplings,
+                           uint64_t& aOutCPUDeltaSum) {
+  GET_JSON(samples, aThread["samples"], Object);
+  {
+    Json::ArrayIndex threadCPUDeltaIndex = 0;
+    GET_JSON(schema, samples["schema"], Object);
+    {
+      GET_JSON(jsonThreadCPUDeltaIndex, schema["threadCPUDelta"], UInt);
+      threadCPUDeltaIndex = jsonThreadCPUDeltaIndex.asUInt();
+    }
+
+    aOutSamplings = 0;
+    aOutCPUDeltaSum = 0;
+    GET_JSON(data, samples["data"], Array);
+    aOutSamplings = data.size();
+    for (const Json::Value& sample : data) {
+      ASSERT_TRUE(sample.isArray());
+      if (sample.isValidIndex(threadCPUDeltaIndex)) {
+        if (!sample[threadCPUDeltaIndex].isNull()) {
+          GET_JSON(cpuDelta, sample[threadCPUDeltaIndex], UInt64);
+          aOutCPUDeltaSum += uint64_t(cpuDelta.asUInt64());
+        }
+      }
+    }
+  }
+}
+
+TEST(GeckoProfiler, CPUUsage)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  const char* filters[] = {"GeckoMain", "Idle test", "Busy test"};
+
+  enum class TestThreadsState {
+    // Initial state, while constructing and starting the idle thread.
+    STARTING,
+    // Set by the idle thread just before running its main mostly-idle loop.
+    RUNNING1,
+    RUNNING2,
+    // Set by the main thread when it wants the idle thread to stop.
+    STOPPING
+  };
+  Atomic<TestThreadsState> testThreadsState{TestThreadsState::STARTING};
+
+  std::thread idle([&]() {
+    AUTO_PROFILER_REGISTER_THREAD("Idle test");
+    // Add a label to ensure that we have a non-empty stack, even if native
+    // stack-walking is not available.
+    AUTO_PROFILER_LABEL("Idle test", PROFILER);
+    ASSERT_TRUE(testThreadsState.compareExchange(TestThreadsState::STARTING,
+                                                 TestThreadsState::RUNNING1) ||
+                testThreadsState.compareExchange(TestThreadsState::RUNNING1,
+                                                 TestThreadsState::RUNNING2));
+
+    while (testThreadsState != TestThreadsState::STOPPING) {
+      // Sleep for multiple profiler intervals, so the profiler should have
+      // samples with zero CPU utilization.
+      PR_Sleep(PR_MillisecondsToInterval(PROFILER_DEFAULT_INTERVAL * 10));
+    }
+  });
+
+  std::thread busy([&]() {
+    AUTO_PROFILER_REGISTER_THREAD("Busy test");
+    // Add a label to ensure that we have a non-empty stack, even if native
+    // stack-walking is not available.
+    AUTO_PROFILER_LABEL("Busy test", PROFILER);
+    ASSERT_TRUE(testThreadsState.compareExchange(TestThreadsState::STARTING,
+                                                 TestThreadsState::RUNNING1) ||
+                testThreadsState.compareExchange(TestThreadsState::RUNNING1,
+                                                 TestThreadsState::RUNNING2));
+
+    while (testThreadsState != TestThreadsState::STOPPING) {
+      // Stay busy!
+    }
+  });
+
+  // Wait for idle thread to start running its main loop.
+  while (testThreadsState != TestThreadsState::RUNNING2) {
+    PR_Sleep(PR_MillisecondsToInterval(1));
+  }
+
+  // We want to ensure that CPU usage numbers are present whether or not we are
+  // collecting stack samples.
+  static constexpr bool scTestsWithOrWithoutStackSampling[] = {false, true};
+  for (const bool testWithNoStackSampling : scTestsWithOrWithoutStackSampling) {
+    ASSERT_TRUE(!profiler_is_active());
+    ASSERT_TRUE(!profiler_callback_after_sampling(
+        [&](SamplingState) { ASSERT_TRUE(false); }));
+
+    profiler_start(
+        PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+        ProfilerFeature::StackWalk | ProfilerFeature::CPUUtilization |
+            (testWithNoStackSampling ? ProfilerFeature::NoStackSampling : 0),
+        filters, MOZ_ARRAY_LENGTH(filters), 0);
+    // Grab a few samples, each with a different label on the stack.
+#  define SAMPLE_LABEL_PREFIX "CPUUsage sample label "
+    static constexpr const char* scSampleLabels[] = {
+        SAMPLE_LABEL_PREFIX "0", SAMPLE_LABEL_PREFIX "1",
+        SAMPLE_LABEL_PREFIX "2", SAMPLE_LABEL_PREFIX "3",
+        SAMPLE_LABEL_PREFIX "4", SAMPLE_LABEL_PREFIX "5",
+        SAMPLE_LABEL_PREFIX "6", SAMPLE_LABEL_PREFIX "7",
+        SAMPLE_LABEL_PREFIX "8", SAMPLE_LABEL_PREFIX "9"};
+    static constexpr size_t scSampleLabelCount =
+        (sizeof(scSampleLabels) / sizeof(scSampleLabels[0]));
+    // We'll do two samplings for each label.
+    static constexpr size_t scMinSamplings = scSampleLabelCount * 2;
+
+    for (const char* sampleLabel : scSampleLabels) {
+      AUTO_PROFILER_LABEL(sampleLabel, OTHER);
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+      // Note: There could have been a delay before this label above, where the
+      // profiler could have sampled the stack and missed the label. By forcing
+      // another sampling now, the label is guaranteed to be present.
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+
+    UniquePtr<char[]> profile = profiler_get_profile();
+
+    if (testWithNoStackSampling) {
+      // If we are testing nostacksampling, we shouldn't find this label prefix
+      // in the profile.
+      EXPECT_FALSE(strstr(profile.get(), SAMPLE_LABEL_PREFIX));
+    } else {
+      // In normal sampling mode, we should find all labels.
+      for (const char* sampleLabel : scSampleLabels) {
+        EXPECT_TRUE(strstr(profile.get(), sampleLabel));
+      }
+    }
+
+    JSONOutputCheck(profile.get(), [testWithNoStackSampling](
+                                       const Json::Value& aRoot) {
+      // Check that the "cpu" feature is present.
+      GET_JSON(meta, aRoot["meta"], Object);
+      {
+        GET_JSON(configuration, meta["configuration"], Object);
+        {
+          GET_JSON(features, configuration["features"], Array);
+          { EXPECT_JSON_ARRAY_CONTAINS(features, String, "cpu"); }
+        }
+      }
+
+      {
+        GET_JSON(sampleUnits, meta["sampleUnits"], Object);
+        {
+          EXPECT_EQ_JSON(sampleUnits["time"], String, "ms");
+          EXPECT_EQ_JSON(sampleUnits["eventDelay"], String, "ms");
+#  if defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+      defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
+          // Note: The exact string is not important here.
+          EXPECT_TRUE(sampleUnits["threadCPUDelta"].isString())
+              << "There should be a sampleUnits.threadCPUDelta on this "
+                 "platform";
+#  else
+        EXPECT_FALSE(sampleUnits.isMember("threadCPUDelta"))
+            << "Unexpected sampleUnits.threadCPUDelta on this platform";;
+#  endif
+        }
+      }
+
+      bool foundMain = false;
+      bool foundIdle = false;
+      uint64_t idleThreadCPUDeltaSum = 0u;
+      bool foundBusy = false;
+      uint64_t busyThreadCPUDeltaSum = 0u;
+
+      // Check that the sample schema contains "threadCPUDelta".
+      GET_JSON(threads, aRoot["threads"], Array);
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          foundMain = true;
+          GET_JSON(samples, thread["samples"], Object);
+          {
+            Json::ArrayIndex stackIndex = 0;
+            Json::ArrayIndex threadCPUDeltaIndex = 0;
+            GET_JSON(schema, samples["schema"], Object);
+            {
+              GET_JSON(jsonStackIndex, schema["stack"], UInt);
+              stackIndex = jsonStackIndex.asUInt();
+              GET_JSON(jsonThreadCPUDeltaIndex, schema["threadCPUDelta"], UInt);
+              threadCPUDeltaIndex = jsonThreadCPUDeltaIndex.asUInt();
+            }
+
+            std::set<uint64_t> stackLeaves;  // To count distinct leaves.
+            unsigned threadCPUDeltaCount = 0;
+            GET_JSON(data, samples["data"], Array);
+            if (testWithNoStackSampling) {
+              // When not sampling stacks, the first sampling loop will have no
+              // running times, so it won't output anything.
+              EXPECT_GE(data.size(), scMinSamplings - 1);
+            } else {
+              EXPECT_GE(data.size(), scMinSamplings);
+            }
+            for (const Json::Value& sample : data) {
+              ASSERT_TRUE(sample.isArray());
+              if (sample.isValidIndex(stackIndex)) {
+                if (!sample[stackIndex].isNull()) {
+                  GET_JSON(stack, sample[stackIndex], UInt64);
+                  stackLeaves.insert(stack.asUInt64());
+                }
+              }
+              if (sample.isValidIndex(threadCPUDeltaIndex)) {
+                if (!sample[threadCPUDeltaIndex].isNull()) {
+                  EXPECT_TRUE(sample[threadCPUDeltaIndex].isUInt64());
+                  ++threadCPUDeltaCount;
+                }
+              }
+            }
+
+            if (testWithNoStackSampling) {
+              // in nostacksampling mode, there should only be one kind of stack
+              // leaf (the root).
+              EXPECT_EQ(stackLeaves.size(), 1u);
+            } else {
+              // in normal sampling mode, there should be at least one kind of
+              // stack leaf for each distinct label.
+              EXPECT_GE(stackLeaves.size(), scSampleLabelCount);
+            }
+
+#  if defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+      defined(GP_OS_linux) || defined(GP_OS_android) || defined(GP_OS_freebsd)
+            EXPECT_GE(threadCPUDeltaCount, data.size() - 1u)
+                << "There should be 'threadCPUDelta' values in all but 1 "
+                   "samples";
+#  else
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(threadCPUDeltaCount, 0u);
+#  endif
+          }
+        } else if (name.asString() == "Idle test") {
+          foundIdle = true;
+          size_t samplings;
+          CountCPUDeltas(thread, samplings, idleThreadCPUDeltaSum);
+          if (testWithNoStackSampling) {
+            // When not sampling stacks, the first sampling loop will have no
+            // running times, so it won't output anything.
+            EXPECT_GE(samplings, scMinSamplings - 1);
+          } else {
+            EXPECT_GE(samplings, scMinSamplings);
+          }
+#  if !(defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+        defined(GP_OS_linux) || defined(GP_OS_android) ||  \
+        defined(GP_OS_freebsd))
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(idleThreadCPUDeltaSum, 0u);
+#  endif
+        } else if (name.asString() == "Busy test") {
+          foundBusy = true;
+          size_t samplings;
+          CountCPUDeltas(thread, samplings, busyThreadCPUDeltaSum);
+          if (testWithNoStackSampling) {
+            // When not sampling stacks, the first sampling loop will have no
+            // running times, so it won't output anything.
+            EXPECT_GE(samplings, scMinSamplings - 1);
+          } else {
+            EXPECT_GE(samplings, scMinSamplings);
+          }
+#  if !(defined(GP_OS_windows) || defined(GP_OS_darwin) || \
+        defined(GP_OS_linux) || defined(GP_OS_android) ||  \
+        defined(GP_OS_freebsd))
+          // All "threadCPUDelta" data should be absent or null on unsupported
+          // platforms.
+          EXPECT_EQ(busyThreadCPUDeltaSum, 0u);
+#  endif
+        }
+      }
+
+      EXPECT_TRUE(foundMain);
+      EXPECT_TRUE(foundIdle);
+      EXPECT_TRUE(foundBusy);
+      EXPECT_LE(idleThreadCPUDeltaSum, busyThreadCPUDeltaSum);
+    });
+
+    // Note: There is no non-racy way to test for SamplingState::JustStopped, as
+    // it would require coordination between `profiler_stop()` and another
+    // thread doing `profiler_callback_after_sampling()` at just the right
+    // moment.
+
+    profiler_stop();
+    ASSERT_TRUE(!profiler_is_active());
+    ASSERT_TRUE(!profiler_callback_after_sampling(
+        [&](SamplingState) { ASSERT_TRUE(false); }));
+  }
+
+  testThreadsState = TestThreadsState::STOPPING;
+  busy.join();
+  idle.join();
+}
+
+TEST(GeckoProfiler, AllThreads)
+{
+  // Bug 1845606
+  #ifdef XP_WIN
+  if (!IsWin8OrLater()) {
+    return;
+  }
+  #endif
+
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  ASSERT_EQ(static_cast<uint32_t>(ThreadProfilingFeatures::Any), 1u + 2u + 4u)
+      << "This test assumes that there are 3 binary choices 1+2+4; "
+         "Is this test up to date?";
+
+  for (uint32_t threadFeaturesBinary = 0u;
+       threadFeaturesBinary <=
+       static_cast<uint32_t>(ThreadProfilingFeatures::Any);
+       ++threadFeaturesBinary) {
+    ThreadProfilingFeatures threadFeatures =
+        static_cast<ThreadProfilingFeatures>(threadFeaturesBinary);
+    const bool threadCPU = DoFeaturesIntersect(
+        threadFeatures, ThreadProfilingFeatures::CPUUtilization);
+    const bool threadSampling =
+        DoFeaturesIntersect(threadFeatures, ThreadProfilingFeatures::Sampling);
+    const bool threadMarkers =
+        DoFeaturesIntersect(threadFeatures, ThreadProfilingFeatures::Markers);
+
+    ASSERT_TRUE(!profiler_is_active());
+
+    uint32_t features = ProfilerFeature::StackWalk;
+    std::string featuresString = "Features: StackWalk Threads";
+    if (threadCPU) {
+      features |= ProfilerFeature::CPUAllThreads;
+      featuresString += " CPUAllThreads";
+    }
+    if (threadSampling) {
+      features |= ProfilerFeature::SamplingAllThreads;
+      featuresString += " SamplingAllThreads";
+    }
+    if (threadMarkers) {
+      features |= ProfilerFeature::MarkersAllThreads;
+      featuresString += " MarkersAllThreads";
+    }
+
+    SCOPED_TRACE(featuresString.c_str());
+
+    const char* filters[] = {"GeckoMain", "Selected"};
+
+    EXPECT_FALSE(profiler_thread_is_being_profiled(
+        ThreadProfilingFeatures::CPUUtilization));
+    EXPECT_FALSE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+    EXPECT_FALSE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+    EXPECT_FALSE(profiler_thread_is_being_profiled_for_markers());
+
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   features, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    EXPECT_TRUE(profiler_thread_is_being_profiled(
+        ThreadProfilingFeatures::CPUUtilization));
+    EXPECT_TRUE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+    EXPECT_TRUE(
+        profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+    EXPECT_TRUE(profiler_thread_is_being_profiled_for_markers());
+
+    // This will signal all threads to stop spinning.
+    Atomic<bool> stopThreads{false};
+
+    Atomic<int> selectedThreadSpins{0};
+    std::thread selectedThread([&]() {
+      AUTO_PROFILER_REGISTER_THREAD("Selected test thread");
+      // Add a label to ensure that we have a non-empty stack, even if native
+      // stack-walking is not available.
+      AUTO_PROFILER_LABEL("Selected test thread", PROFILER);
+      EXPECT_TRUE(profiler_thread_is_being_profiled(
+          ThreadProfilingFeatures::CPUUtilization));
+      EXPECT_TRUE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+      EXPECT_TRUE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+      EXPECT_TRUE(profiler_thread_is_being_profiled_for_markers());
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Selected!", PROFILER);
+        ++selectedThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    Atomic<int> unselectedThreadSpins{0};
+    std::thread unselectedThread([&]() {
+      AUTO_PROFILER_REGISTER_THREAD("Registered test thread");
+      // Add a label to ensure that we have a non-empty stack, even if native
+      // stack-walking is not available.
+      AUTO_PROFILER_LABEL("Registered test thread", PROFILER);
+      // This thread is *not* selected for full profiling, but it may still be
+      // profiled depending on the -allthreads features.
+      EXPECT_EQ(profiler_thread_is_being_profiled(
+                    ThreadProfilingFeatures::CPUUtilization),
+                threadCPU);
+      EXPECT_EQ(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling),
+          threadSampling);
+      EXPECT_EQ(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers),
+          threadMarkers);
+      EXPECT_EQ(profiler_thread_is_being_profiled_for_markers(), threadMarkers);
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Registered!", PROFILER);
+        ++unselectedThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    Atomic<int> unregisteredThreadSpins{0};
+    std::thread unregisteredThread([&]() {
+      // No `AUTO_PROFILER_REGISTER_THREAD` here.
+      EXPECT_FALSE(profiler_thread_is_being_profiled(
+          ThreadProfilingFeatures::CPUUtilization));
+      EXPECT_FALSE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Sampling));
+      EXPECT_FALSE(
+          profiler_thread_is_being_profiled(ThreadProfilingFeatures::Markers));
+      EXPECT_FALSE(profiler_thread_is_being_profiled_for_markers());
+      while (!stopThreads) {
+        PROFILER_MARKER_UNTYPED("Spinning Unregistered!", PROFILER);
+        ++unregisteredThreadSpins;
+        PR_Sleep(PR_MillisecondsToInterval(1));
+      }
+    });
+
+    // Wait for all threads to have started at least one spin.
+    while (selectedThreadSpins == 0 || unselectedThreadSpins == 0 ||
+           unregisteredThreadSpins == 0) {
+      PR_Sleep(PR_MillisecondsToInterval(1));
+    }
+
+    // Wait until the sampler has done at least one loop.
+    ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+    // Restart the spin counts, and ensure each threads will do at least one
+    // more spin each. Since spins are increased after PROFILER_MARKER calls, in
+    // the worst case, each thread will have attempted to record at least one
+    // marker.
+    selectedThreadSpins = 0;
+    unselectedThreadSpins = 0;
+    unregisteredThreadSpins = 0;
+    while (selectedThreadSpins < 1 && unselectedThreadSpins < 1 &&
+           unregisteredThreadSpins < 1) {
+      ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+    }
+
+    profiler_pause();
+    UniquePtr<char[]> profile = profiler_get_profile();
+
+    profiler_stop();
+    stopThreads = true;
+    unregisteredThread.join();
+    unselectedThread.join();
+    selectedThread.join();
+
+    JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+      GET_JSON(threads, aRoot["threads"], Array);
+      int foundMain = 0;
+      int foundSelected = 0;
+      int foundSelectedMarker = 0;
+      int foundUnselected = 0;
+      int foundUnselectedMarker = 0;
+      for (const Json::Value& thread : threads) {
+        ASSERT_TRUE(thread.isObject());
+        GET_JSON(stringTable, thread["stringTable"], Array);
+        GET_JSON(name, thread["name"], String);
+        if (name.asString() == "GeckoMain") {
+          ++foundMain;
+          // Don't check the main thread further in this test.
+
+        } else if (name.asString() == "Selected test thread") {
+          ++foundSelected;
+
+          GET_JSON(samples, thread["samples"], Object);
+          GET_JSON(samplesData, samples["data"], Array);
+          EXPECT_GT(samplesData.size(), 0u);
+
+          GET_JSON(markers, thread["markers"], Object);
+          GET_JSON(markersData, markers["data"], Array);
+          for (const Json::Value& marker : markersData) {
+            const unsigned int NAME = 0u;
+            ASSERT_TRUE(marker[NAME].isUInt());  // name id
+            GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+            if (name == "Spinning Selected!") {
+              ++foundSelectedMarker;
+            }
+          }
+        } else if (name.asString() == "Registered test thread") {
+          ++foundUnselected;
+
+          GET_JSON(samples, thread["samples"], Object);
+          GET_JSON(samplesData, samples["data"], Array);
+          if (threadCPU || threadSampling) {
+            EXPECT_GT(samplesData.size(), 0u);
+          } else {
+            EXPECT_EQ(samplesData.size(), 0u);
+          }
+
+          GET_JSON(markers, thread["markers"], Object);
+          GET_JSON(markersData, markers["data"], Array);
+          for (const Json::Value& marker : markersData) {
+            const unsigned int NAME = 0u;
+            ASSERT_TRUE(marker[NAME].isUInt());  // name id
+            GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+            if (name == "Spinning Registered!") {
+              ++foundUnselectedMarker;
+            }
+          }
+
+        } else {
+          EXPECT_STRNE(name.asString().c_str(),
+                       "Unregistered test thread label");
+        }
+      }
+      EXPECT_EQ(foundMain, 1);
+      EXPECT_EQ(foundSelected, 1);
+      EXPECT_GT(foundSelectedMarker, 0);
+      EXPECT_EQ(foundUnselected,
+                (threadCPU || threadSampling || threadMarkers) ? 1 : 0)
+          << "Unselected thread should only be present if at least one of the "
+             "allthreads feature is on";
+      if (threadMarkers) {
+        EXPECT_GT(foundUnselectedMarker, 0);
+      } else {
+        EXPECT_EQ(foundUnselectedMarker, 0);
+      }
+    });
+  }
+}
+
+TEST(GeckoProfiler, FailureHandling)
+{
+  profiler_init_main_thread_id();
+  ASSERT_TRUE(profiler_is_main_thread())
+  << "This test assumes it runs on the main thread";
+
+  uint32_t features = ProfilerFeature::StackWalk;
+  const char* filters[] = {"GeckoMain"};
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+
+  // User-defined marker type that generates a failure when streaming JSON.
+  struct GtestFailingMarker {
+    static constexpr Span<const char> MarkerTypeName() {
+      return MakeStringSpan("markers-gtest-failing");
+    }
+    static void StreamJSONMarkerData(
+        mozilla::baseprofiler::SpliceableJSONWriter& aWriter) {
+      aWriter.SetFailure("boom!");
+    }
+    static mozilla::MarkerSchema MarkerTypeDisplay() {
+      return mozilla::MarkerSchema::SpecialFrontendLocation{};
+    }
+  };
+  EXPECT_TRUE(profiler_add_marker("Gtest failing marker",
+                                  geckoprofiler::category::OTHER, {},
+                                  GtestFailingMarker{}));
+
+  ASSERT_EQ(WaitForSamplingState(), SamplingState::SamplingCompleted);
+  profiler_pause();
+
+  FailureLatchSource failureLatch;
+  SpliceableChunkedJSONWriter w{failureLatch};
+  EXPECT_FALSE(w.Failed());
+  ASSERT_FALSE(w.GetFailure());
+
+  w.Start();
+  EXPECT_FALSE(w.Failed());
+  ASSERT_FALSE(w.GetFailure());
+
+  // The marker will cause a failure during this function call.
+  EXPECT_FALSE(::profiler_stream_json_for_this_process(w).isOk());
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  // Already failed, check that we don't crash or reset the failure.
+  EXPECT_FALSE(::profiler_stream_json_for_this_process(w).isOk());
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  w.End();
+
+  profiler_stop();
+
+  EXPECT_TRUE(w.Failed());
+  ASSERT_TRUE(w.GetFailure());
+  EXPECT_EQ(strcmp(w.GetFailure(), "boom!"), 0);
+
+  UniquePtr<char[]> profile = w.ChunkedWriteFunc().CopyData();
+  ASSERT_EQ(profile.get(), nullptr);
+}
+
+TEST(GeckoProfiler, NoMarkerStacks)
+{
+  uint32_t features = ProfilerFeature::NoMarkerStacks;
+  const char* filters[] = {"GeckoMain"};
+
+  ASSERT_TRUE(!profiler_get_profile());
+
+  // Make sure that profiler_capture_backtrace returns nullptr when the profiler
+  // is not active.
+  ASSERT_TRUE(!profiler_capture_backtrace());
+
+  {
+    // Start the profiler without the NoMarkerStacks feature and make sure we
+    // capture stacks.
+    profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL,
+                   /* features */ 0, filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+    ASSERT_TRUE(profiler_capture_backtrace());
+    profiler_stop();
+  }
+
+  // Start the profiler without the NoMarkerStacks feature and make sure we
+  // don't capture stacks.
+  profiler_start(PROFILER_DEFAULT_ENTRIES, PROFILER_DEFAULT_INTERVAL, features,
+                 filters, MOZ_ARRAY_LENGTH(filters), 0);
+
+  // Make sure that the active features has the NoMarkerStacks feature.
+  mozilla::Maybe<uint32_t> activeFeatures = profiler_features_if_active();
+  ASSERT_TRUE(activeFeatures.isSome());
+  ASSERT_TRUE(ProfilerFeature::HasNoMarkerStacks(*activeFeatures));
+
+  // Make sure we don't capture stacks.
+  ASSERT_TRUE(!profiler_capture_backtrace());
+
+  // Add a marker with a stack to test.
+  EXPECT_TRUE(profiler_add_marker(
+      "Text with stack", geckoprofiler::category::OTHER, MarkerStack::Capture(),
+      geckoprofiler::markers::TextMarker{}, ""));
+
+  UniquePtr<char[]> profile = profiler_get_profile();
+  JSONOutputCheck(profile.get(), [&](const Json::Value& aRoot) {
+    // Check that the meta.configuration.features array contains
+    // "nomarkerstacks".
+    GET_JSON(meta, aRoot["meta"], Object);
+    {
+      GET_JSON(configuration, meta["configuration"], Object);
+      {
+        GET_JSON(features, configuration["features"], Array);
+        {
+          EXPECT_EQ(features.size(), 1u);
+          EXPECT_JSON_ARRAY_CONTAINS(features, String, "nomarkerstacks");
+        }
+      }
+    }
+
+    // Make sure that the marker we captured doesn't have a stack.
+    GET_JSON(threads, aRoot["threads"], Array);
+    {
+      ASSERT_EQ(threads.size(), 1u);
+      GET_JSON(thread0, threads[0], Object);
+      {
+        GET_JSON(markers, thread0["markers"], Object);
+        {
+          GET_JSON(data, markers["data"], Array);
+          {
+            const unsigned int NAME = 0u;
+            const unsigned int PAYLOAD = 5u;
+            bool foundMarker = false;
+            GET_JSON(stringTable, thread0["stringTable"], Array);
+
+            for (const Json::Value& marker : data) {
+              // Even though we only added one marker, some markers like
+              // NotifyObservers are being added as well. Let's iterate over
+              // them and make sure that we have the one we added explicitly and
+              // check its stack doesn't exist.
+              GET_JSON(name, stringTable[marker[NAME].asUInt()], String);
+              std::string nameString = name.asString();
+
+              if (nameString == "Text with stack") {
+                // Make sure that the marker doesn't have a stack.
+                foundMarker = true;
+                EXPECT_FALSE(marker[PAYLOAD].isNull());
+                EXPECT_TRUE(marker[PAYLOAD]["stack"].isNull());
+              }
+            }
+
+            EXPECT_TRUE(foundMarker);
+          }
+        }
+      }
+    }
+  });
+
+  profiler_stop();
+
+  ASSERT_TRUE(!profiler_get_profile());
+}
+
+#endif  // MOZ_GECKO_PROFILER
diff --git a/tools/profiler/tests/gtest/LulTest.cpp b/tools/profiler/tests/gtest/LulTest.cpp
new file mode 100644
index 0000000000..159a366567
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTest.cpp
@@ -0,0 +1,51 @@
+/* -*- 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/. */
+
+#include "gtest/gtest.h"
+#include "mozilla/Atomics.h"
+#include "LulMain.h"
+#include "GeckoProfiler.h"       // for TracingKind
+#include "platform-linux-lul.h"  // for read_procmaps
+
+// Set this to 0 to make LUL be completely silent during tests.
+// Set it to 1 to get logging output from LUL, presumably for
+// the purpose of debugging it.
+#define DEBUG_LUL_TEST 0
+
+// LUL needs a callback for its logging sink.
+static void gtest_logging_sink_for_LulIntegration(const char* str) {
+  if (DEBUG_LUL_TEST == 0) {
+    return;
+  }
+  // Ignore any trailing \n, since LOG will add one anyway.
+  size_t n = strlen(str);
+  if (n > 0 && str[n - 1] == '\n') {
+    char* tmp = strdup(str);
+    tmp[n - 1] = 0;
+    fprintf(stderr, "LUL-in-gtest: %s\n", tmp);
+    free(tmp);
+  } else {
+    fprintf(stderr, "LUL-in-gtest: %s\n", str);
+  }
+}
+
+TEST(LulIntegration, unwind_consistency)
+{
+  // Set up LUL and get it to read unwind info for libxul.so, which is
+  // all we care about here, plus (incidentally) practically every
+  // other object in the process too.
+  lul::LUL* lul = new lul::LUL(gtest_logging_sink_for_LulIntegration);
+  read_procmaps(lul);
+
+  // Run unwind tests and receive information about how many there
+  // were and how many were successful.
+  lul->EnableUnwinding();
+  int nTests = 0, nTestsPassed = 0;
+  RunLulUnitTests(&nTests, &nTestsPassed, lul);
+  EXPECT_TRUE(nTests == 6) << "Unexpected number of tests";
+  EXPECT_EQ(nTestsPassed, nTests) << "Not all tests passed";
+
+  delete lul;
+}
diff --git a/tools/profiler/tests/gtest/LulTestDwarf.cpp b/tools/profiler/tests/gtest/LulTestDwarf.cpp
new file mode 100644
index 0000000000..55373ec093
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestDwarf.cpp
@@ -0,0 +1,2733 @@
+/* -*- 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/. */
+
+#include "gtest/gtest.h"
+#include "gmock/gmock.h"
+#include "LulCommonExt.h"
+#include "LulDwarfExt.h"
+#include "LulDwarfInt.h"
+#include "LulTestInfrastructure.h"
+
+using lul_test::CFISection;
+using lul_test::test_assembler::kBigEndian;
+using lul_test::test_assembler::kLittleEndian;
+using lul_test::test_assembler::Label;
+using testing::_;
+using testing::InSequence;
+using testing::Return;
+using testing::Sequence;
+using testing::Test;
+
+#define PERHAPS_WRITE_DEBUG_FRAME_FILE(name, section) /**/
+#define PERHAPS_WRITE_EH_FRAME_FILE(name, section)    /**/
+
+// Set this to 0 to make LUL be completely silent during tests.
+// Set it to 1 to get logging output from LUL, presumably for
+// the purpose of debugging it.
+#define DEBUG_LUL_TEST_DWARF 0
+
+// LUL needs a callback for its logging sink.
+static void gtest_logging_sink_for_LulTestDwarf(const char* str) {
+  if (DEBUG_LUL_TEST_DWARF == 0) {
+    return;
+  }
+  // Ignore any trailing \n, since LOG will add one anyway.
+  size_t n = strlen(str);
+  if (n > 0 && str[n - 1] == '\n') {
+    char* tmp = strdup(str);
+    tmp[n - 1] = 0;
+    fprintf(stderr, "LUL-in-gtest: %s\n", tmp);
+    free(tmp);
+  } else {
+    fprintf(stderr, "LUL-in-gtest: %s\n", str);
+  }
+}
+
+namespace lul {
+
+class MockCallFrameInfoHandler : public CallFrameInfo::Handler {
+ public:
+  MOCK_METHOD6(Entry,
+               bool(size_t offset, uint64 address, uint64 length, uint8 version,
+                    const std::string& augmentation, unsigned return_address));
+  MOCK_METHOD2(UndefinedRule, bool(uint64 address, int reg));
+  MOCK_METHOD2(SameValueRule, bool(uint64 address, int reg));
+  MOCK_METHOD4(OffsetRule,
+               bool(uint64 address, int reg, int base_register, long offset));
+  MOCK_METHOD4(ValOffsetRule,
+               bool(uint64 address, int reg, int base_register, long offset));
+  MOCK_METHOD3(RegisterRule, bool(uint64 address, int reg, int base_register));
+  MOCK_METHOD3(ExpressionRule,
+               bool(uint64 address, int reg, const ImageSlice& expression));
+  MOCK_METHOD3(ValExpressionRule,
+               bool(uint64 address, int reg, const ImageSlice& expression));
+  MOCK_METHOD0(End, bool());
+  MOCK_METHOD2(PersonalityRoutine, bool(uint64 address, bool indirect));
+  MOCK_METHOD2(LanguageSpecificDataArea, bool(uint64 address, bool indirect));
+  MOCK_METHOD0(SignalHandler, bool());
+};
+
+class MockCallFrameErrorReporter : public CallFrameInfo::Reporter {
+ public:
+  MockCallFrameErrorReporter()
+      : Reporter(gtest_logging_sink_for_LulTestDwarf, "mock filename",
+                 "mock section") {}
+  MOCK_METHOD2(Incomplete, void(uint64, CallFrameInfo::EntryKind));
+  MOCK_METHOD1(EarlyEHTerminator, void(uint64));
+  MOCK_METHOD2(CIEPointerOutOfRange, void(uint64, uint64));
+  MOCK_METHOD2(BadCIEId, void(uint64, uint64));
+  MOCK_METHOD2(UnrecognizedVersion, void(uint64, int version));
+  MOCK_METHOD2(UnrecognizedAugmentation, void(uint64, const string&));
+  MOCK_METHOD2(InvalidPointerEncoding, void(uint64, uint8));
+  MOCK_METHOD2(UnusablePointerEncoding, void(uint64, uint8));
+  MOCK_METHOD2(RestoreInCIE, void(uint64, uint64));
+  MOCK_METHOD3(BadInstruction, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(NoCFARule, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(EmptyStateStack, void(uint64, CallFrameInfo::EntryKind, uint64));
+  MOCK_METHOD3(ClearingCFARule, void(uint64, CallFrameInfo::EntryKind, uint64));
+};
+
+struct CFIFixture {
+  enum { kCFARegister = CallFrameInfo::Handler::kCFARegister };
+
+  CFIFixture() {
+    // Default expectations for the data handler.
+    //
+    // - Leave Entry and End without expectations, as it's probably a
+    //   good idea to set those explicitly in each test.
+    //
+    // - Expect the *Rule functions to not be called,
+    //   so that each test can simply list the calls they expect.
+    //
+    // I gather I could use StrictMock for this, but the manual seems
+    // to suggest using that only as a last resort, and this isn't so
+    // bad.
+    EXPECT_CALL(handler, UndefinedRule(_, _)).Times(0);
+    EXPECT_CALL(handler, SameValueRule(_, _)).Times(0);
+    EXPECT_CALL(handler, OffsetRule(_, _, _, _)).Times(0);
+    EXPECT_CALL(handler, ValOffsetRule(_, _, _, _)).Times(0);
+    EXPECT_CALL(handler, RegisterRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, ExpressionRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, ValExpressionRule(_, _, _)).Times(0);
+    EXPECT_CALL(handler, PersonalityRoutine(_, _)).Times(0);
+    EXPECT_CALL(handler, LanguageSpecificDataArea(_, _)).Times(0);
+    EXPECT_CALL(handler, SignalHandler()).Times(0);
+
+    // Default expectations for the error/warning reporer.
+    EXPECT_CALL(reporter, Incomplete(_, _)).Times(0);
+    EXPECT_CALL(reporter, EarlyEHTerminator(_)).Times(0);
+    EXPECT_CALL(reporter, CIEPointerOutOfRange(_, _)).Times(0);
+    EXPECT_CALL(reporter, BadCIEId(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnrecognizedVersion(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnrecognizedAugmentation(_, _)).Times(0);
+    EXPECT_CALL(reporter, InvalidPointerEncoding(_, _)).Times(0);
+    EXPECT_CALL(reporter, UnusablePointerEncoding(_, _)).Times(0);
+    EXPECT_CALL(reporter, RestoreInCIE(_, _)).Times(0);
+    EXPECT_CALL(reporter, BadInstruction(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, NoCFARule(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, EmptyStateStack(_, _, _)).Times(0);
+    EXPECT_CALL(reporter, ClearingCFARule(_, _, _)).Times(0);
+  }
+
+  MockCallFrameInfoHandler handler;
+  MockCallFrameErrorReporter reporter;
+};
+
+class LulDwarfCFI : public CFIFixture, public Test {};
+
+TEST_F(LulDwarfCFI, EmptyRegion) {
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+  static const char data[1] = {42};
+
+  ByteReader reader(ENDIANNESS_BIG);
+  CallFrameInfo parser(data, 0, &reader, &handler, &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteLength32) {
+  CFISection section(kBigEndian, 8);
+  section
+      // Not even long enough for an initial length.
+      .D16(0xa0f)
+      // Padding to keep valgrind happy. We subtract these off when we
+      // construct the parser.
+      .D16(0);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size() - 2, &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteLength64) {
+  CFISection section(kLittleEndian, 4);
+  section
+      // An incomplete 64-bit DWARF initial length.
+      .D32(0xffffffff)
+      .D32(0x71fbaec2)
+      // Padding to keep valgrind happy. We subtract these off when we
+      // construct the parser.
+      .D32(0);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size() - 4, &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, IncompleteId32) {
+  CFISection section(kBigEndian, 8);
+  section
+      .D32(3)  // Initial length, not long enough for id
+      .D8(0xd7)
+      .D8(0xe5)
+      .D8(0xf1)  // incomplete id
+      .CIEHeader(8727, 3983, 8889, 3, "")
+      .FinishEntry();
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, Incomplete(_, CallFrameInfo::kUnknown))
+      .WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+TEST_F(LulDwarfCFI, BadId32) {
+  CFISection section(kBigEndian, 8);
+  section
+      .D32(0x100)                // Initial length
+      .D32(0xe802fade)           // bogus ID
+      .Append(0x100 - 4, 0x42);  // make the length true
+  section.CIEHeader(1672, 9872, 8529, 3, "").FinishEntry();
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  EXPECT_CALL(reporter, CIEPointerOutOfRange(_, 0xe802fade)).WillOnce(Return());
+
+  string contents;
+  ASSERT_TRUE(section.GetContents(&contents));
+
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// A lone CIE shouldn't cause any handler calls.
+TEST_F(LulDwarfCFI, SingleCIE) {
+  CFISection section(kLittleEndian, 4);
+  section.CIEHeader(0xffe799a8, 0x3398dcdd, 0x6e9683de, 3, "");
+  section.Append(10, lul::DW_CFA_nop);
+  section.FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("SingleCIE", section);
+
+  EXPECT_CALL(handler, Entry(_, _, _, _, _, _)).Times(0);
+  EXPECT_CALL(handler, End()).Times(0);
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// One FDE, one CIE.
+TEST_F(LulDwarfCFI, OneFDE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(0x4be22f75, 0x2492236e, 0x6b6efb87, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie, 0x7714740d, 0x3d5a10cd)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("OneFDE", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x7714740d, 0x3d5a10cd, 3, "", 0x6b6efb87))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// Two FDEs share a CIE.
+TEST_F(LulDwarfCFI, TwoFDEsOneCIE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // First FDE. readelf complains about this one because it makes
+      // a forward reference to its CIE.
+      .FDEHeader(cie, 0xa42744df, 0xa3b42121)
+      .FinishEntry()
+      // CIE.
+      .Mark(&cie)
+      .CIEHeader(0x04f7dc7b, 0x3d00c05f, 0xbd43cb59, 3, "")
+      .FinishEntry()
+      // Second FDE.
+      .FDEHeader(cie, 0x6057d391, 0x700f608d)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("TwoFDEsOneCIE", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xa42744df, 0xa3b42121, 3, "", 0xbd43cb59))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x6057d391, 0x700f608d, 3, "", 0xbd43cb59))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// Two FDEs, two CIEs.
+TEST_F(LulDwarfCFI, TwoFDEsTwoCIEs) {
+  CFISection section(kLittleEndian, 8);
+  Label cie1, cie2;
+  section
+      // First CIE.
+      .Mark(&cie1)
+      .CIEHeader(0x694d5d45, 0x4233221b, 0xbf45e65a, 3, "")
+      .FinishEntry()
+      // First FDE which cites second CIE. readelf complains about
+      // this one because it makes a forward reference to its CIE.
+      .FDEHeader(cie2, 0x778b27dfe5871f05ULL, 0x324ace3448070926ULL)
+      .FinishEntry()
+      // Second FDE, which cites first CIE.
+      .FDEHeader(cie1, 0xf6054ca18b10bf5fULL, 0x45fdb970d8bca342ULL)
+      .FinishEntry()
+      // Second CIE.
+      .Mark(&cie2)
+      .CIEHeader(0xfba3fad7, 0x6287e1fd, 0x61d2c581, 2, "")
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("TwoFDEsTwoCIEs", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x778b27dfe5871f05ULL, 0x324ace3448070926ULL,
+                               2, "", 0x61d2c581))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xf6054ca18b10bf5fULL, 0x45fdb970d8bca342ULL,
+                               3, "", 0xbf45e65a))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_LITTLE);
+  reader.SetAddressSize(8);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// An FDE whose CIE specifies a version we don't recognize.
+TEST_F(LulDwarfCFI, BadVersion) {
+  CFISection section(kBigEndian, 4);
+  Label cie1, cie2;
+  section.Mark(&cie1)
+      .CIEHeader(0xca878cf0, 0x7698ec04, 0x7b616f54, 0x52, "")
+      .FinishEntry()
+      // We should skip this entry, as its CIE specifies a version we
+      // don't recognize.
+      .FDEHeader(cie1, 0x08852292, 0x2204004a)
+      .FinishEntry()
+      // Despite the above, we should visit this entry.
+      .Mark(&cie2)
+      .CIEHeader(0x7c3ae7c9, 0xb9b9a512, 0x96cb3264, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie2, 0x2094735a, 0x6e875501)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("BadVersion", section);
+
+  EXPECT_CALL(reporter, UnrecognizedVersion(_, 0x52)).WillOnce(Return());
+
+  {
+    InSequence s;
+    // We should see no mention of the first FDE, but we should get
+    // a call to Entry for the second.
+    EXPECT_CALL(handler, Entry(_, 0x2094735a, 0x6e875501, 3, "", 0x96cb3264))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// An FDE whose CIE specifies an augmentation we don't recognize.
+TEST_F(LulDwarfCFI, BadAugmentation) {
+  CFISection section(kBigEndian, 4);
+  Label cie1, cie2;
+  section.Mark(&cie1)
+      .CIEHeader(0x4be22f75, 0x2492236e, 0x6b6efb87, 3, "spaniels!")
+      .FinishEntry()
+      // We should skip this entry, as its CIE specifies an
+      // augmentation we don't recognize.
+      .FDEHeader(cie1, 0x7714740d, 0x3d5a10cd)
+      .FinishEntry()
+      // Despite the above, we should visit this entry.
+      .Mark(&cie2)
+      .CIEHeader(0xf8bc4399, 0x8cf09931, 0xf2f519b2, 3, "")
+      .FinishEntry()
+      .FDEHeader(cie2, 0x7bf0fda0, 0xcbcd28d8)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("BadAugmentation", section);
+
+  EXPECT_CALL(reporter, UnrecognizedAugmentation(_, "spaniels!"))
+      .WillOnce(Return());
+
+  {
+    InSequence s;
+    // We should see no mention of the first FDE, but we should get
+    // a call to Entry for the second.
+    EXPECT_CALL(handler, Entry(_, 0x7bf0fda0, 0xcbcd28d8, 3, "", 0xf2f519b2))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_FALSE(parser.Start());
+}
+
+// The return address column field is a byte in CFI version 1
+// (DWARF2), but a ULEB128 value in version 3 (DWARF3).
+TEST_F(LulDwarfCFI, CIEVersion1ReturnColumn) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, using the version 1 format: return column is a ubyte.
+      .Mark(&cie)
+      // Use a value for the return column that is parsed differently
+      // as a ubyte and as a ULEB128.
+      .CIEHeader(0xbcdea24f, 0x5be28286, 0x9f, 1, "")
+      .FinishEntry()
+      // FDE, citing that CIE.
+      .FDEHeader(cie, 0xb8d347b5, 0x825e55dc)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("CIEVersion1ReturnColumn", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0xb8d347b5, 0x825e55dc, 1, "", 0x9f))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+// The return address column field is a byte in CFI version 1
+// (DWARF2), but a ULEB128 value in version 3 (DWARF3).
+TEST_F(LulDwarfCFI, CIEVersion3ReturnColumn) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, using the version 3 format: return column is a ULEB128.
+      .Mark(&cie)
+      // Use a value for the return column that is parsed differently
+      // as a ubyte and as a ULEB128.
+      .CIEHeader(0x0ab4758d, 0xc010fdf7, 0x89, 3, "")
+      .FinishEntry()
+      // FDE, citing that CIE.
+      .FDEHeader(cie, 0x86763f2b, 0x2a66dc23)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("CIEVersion3ReturnColumn", section);
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler, Entry(_, 0x86763f2b, 0x2a66dc23, 3, "", 0x89))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  string contents;
+  EXPECT_TRUE(section.GetContents(&contents));
+  ByteReader reader(ENDIANNESS_BIG);
+  reader.SetAddressSize(4);
+  CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                       &reporter);
+  EXPECT_TRUE(parser.Start());
+}
+
+struct CFIInsnFixture : public CFIFixture {
+  CFIInsnFixture() : CFIFixture() {
+    data_factor = 0xb6f;
+    return_register = 0x9be1ed9f;
+    version = 3;
+    cfa_base_register = 0x383a3aa;
+    cfa_offset = 0xf748;
+  }
+
+  // Prepare SECTION to receive FDE instructions.
+  //
+  // - Append a stock CIE header that establishes the fixture's
+  //   code_factor, data_factor, return_register, version, and
+  //   augmentation values.
+  // - Have the CIE set up a CFA rule using cfa_base_register and
+  //   cfa_offset.
+  // - Append a stock FDE header, referring to the above CIE, for the
+  //   fde_size bytes at fde_start. Choose fde_start and fde_size
+  //   appropriately for the section's address size.
+  // - Set appropriate expectations on handler in sequence s for the
+  //   frame description entry and the CIE's CFA rule.
+  //
+  // On return, SECTION is ready to have FDE instructions appended to
+  // it, and its FinishEntry member called.
+  void StockCIEAndFDE(CFISection* section) {
+    // Choose appropriate constants for our address size.
+    if (section->AddressSize() == 4) {
+      fde_start = 0xc628ecfbU;
+      fde_size = 0x5dee04a2;
+      code_factor = 0x60b;
+    } else {
+      assert(section->AddressSize() == 8);
+      fde_start = 0x0005c57ce7806bd3ULL;
+      fde_size = 0x2699521b5e333100ULL;
+      code_factor = 0x01008e32855274a8ULL;
+    }
+
+    // Create the CIE.
+    (*section)
+        .Mark(&cie_label)
+        .CIEHeader(code_factor, data_factor, return_register, version, "")
+        .D8(lul::DW_CFA_def_cfa)
+        .ULEB128(cfa_base_register)
+        .ULEB128(cfa_offset)
+        .FinishEntry();
+
+    // Create the FDE.
+    section->FDEHeader(cie_label, fde_start, fde_size);
+
+    // Expect an Entry call for the FDE and a ValOffsetRule call for the
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .InSequence(s)
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister,
+                                       cfa_base_register, cfa_offset))
+        .InSequence(s)
+        .WillOnce(Return(true));
+  }
+
+  // Run the contents of SECTION through a CallFrameInfo parser,
+  // expecting parser.Start to return SUCCEEDS.  Caller may optionally
+  // supply, via READER, its own ByteReader.  If that's absent, a
+  // local one is used.
+  void ParseSection(CFISection* section, bool succeeds = true,
+                    ByteReader* reader = nullptr) {
+    string contents;
+    EXPECT_TRUE(section->GetContents(&contents));
+    lul::Endianness endianness;
+    if (section->endianness() == kBigEndian)
+      endianness = ENDIANNESS_BIG;
+    else {
+      assert(section->endianness() == kLittleEndian);
+      endianness = ENDIANNESS_LITTLE;
+    }
+    ByteReader local_reader(endianness);
+    ByteReader* reader_to_use = reader ? reader : &local_reader;
+    reader_to_use->SetAddressSize(section->AddressSize());
+    CallFrameInfo parser(contents.data(), contents.size(), reader_to_use,
+                         &handler, &reporter);
+    if (succeeds)
+      EXPECT_TRUE(parser.Start());
+    else
+      EXPECT_FALSE(parser.Start());
+  }
+
+  Label cie_label;
+  Sequence s;
+  uint64 code_factor;
+  int data_factor;
+  unsigned return_register;
+  unsigned version;
+  unsigned cfa_base_register;
+  int cfa_offset;
+  uint64 fde_start, fde_size;
+};
+
+class LulDwarfCFIInsn : public CFIInsnFixture, public Test {};
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_set_loc) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_set_loc)
+      .D32(0xb1ee3e7a)
+      // Use DW_CFA_def_cfa to force a handler call that we can use to
+      // check the effect of the DW_CFA_set_loc.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x4defb431)
+      .ULEB128(0x6d17b0ee)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_set_loc", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(0xb1ee3e7a, kCFARegister, 0x4defb431, 0x6d17b0ee))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section
+      .D8(lul::DW_CFA_advance_loc | 0x2a)
+      // Use DW_CFA_def_cfa to force a handler call that we can use to
+      // check the effect of the DW_CFA_advance_loc.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x5bbb3715)
+      .ULEB128(0x0186c7bf)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc", section);
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 0x2a * code_factor,
+                                     kCFARegister, 0x5bbb3715, 0x0186c7bf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc1) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc1)
+      .D8(0xd8)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x69d5696a)
+      .ULEB128(0x1eb7fc93)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc1", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0xd8 * code_factor),
+                                     kCFARegister, 0x69d5696a, 0x1eb7fc93))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc2) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc2)
+      .D16(0x3adb)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x3a368bed)
+      .ULEB128(0x3194ee37)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc2", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0x3adb * code_factor),
+                                     kCFARegister, 0x3a368bed, 0x3194ee37))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_advance_loc4) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_advance_loc4)
+      .D32(0x15813c88)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x135270c5)
+      .ULEB128(0x24bad7cb)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc4", section);
+
+  EXPECT_CALL(handler, ValOffsetRule((fde_start + 0x15813c88ULL * code_factor),
+                                     kCFARegister, 0x135270c5, 0x24bad7cb))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_MIPS_advance_loc8) {
+  code_factor = 0x2d;
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_MIPS_advance_loc8)
+      .D64(0x3c4f3945b92c14ULL)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0xe17ed602)
+      .ULEB128(0x3d162e7f)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_advance_loc8", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule((fde_start + 0x3c4f3945b92c14ULL * code_factor),
+                            kCFARegister, 0xe17ed602, 0x3d162e7f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x4e363a85)
+      .ULEB128(0x815f9aa7)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("DW_CFA_def_cfa", section);
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x4e363a85, 0x815f9aa7))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_sf) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_sf)
+      .ULEB128(0x8ccb32b7)
+      .LEB128(0x9ea)
+      .D8(lul::DW_CFA_def_cfa_sf)
+      .ULEB128(0x9b40f5da)
+      .LEB128(-0x40a2)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, 0x8ccb32b7,
+                                     0x9ea * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, 0x9b40f5da,
+                                     -0x40a2 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_register) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_register).ULEB128(0x3e7e9363).FinishEntry();
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x3e7e9363, cfa_offset))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// DW_CFA_def_cfa_register should have no effect when applied to a
+// non-base/offset rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_registerBadRule) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  ImageSlice expr("needle in a haystack");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_expression)
+      .Block(expr)
+      .D8(lul::DW_CFA_def_cfa_register)
+      .ULEB128(0xf1b49e49)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .WillRepeatedly(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_offset).ULEB128(0x1e8e3b9b).FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     0x1e8e3b9b))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offset_sf) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_offset_sf)
+      .LEB128(0x970)
+      .D8(lul::DW_CFA_def_cfa_offset_sf)
+      .LEB128(-0x2cd)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     0x970 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, kCFARegister, cfa_base_register,
+                                     -0x2cd * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// DW_CFA_def_cfa_offset should have no effect when applied to a
+// non-base/offset rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_offsetBadRule) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  ImageSlice expr("six ways to Sunday");
+  section.D8(lul::DW_CFA_def_cfa_expression)
+      .Block(expr)
+      .D8(lul::DW_CFA_def_cfa_offset)
+      .ULEB128(0x1e8e3b9b)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .WillRepeatedly(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_def_cfa_expression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 8);
+  ImageSlice expr("eating crow");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_def_cfa_expression).Block(expr).FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, kCFARegister, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_undefined) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined).ULEB128(0x300ce45d).FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x300ce45d))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_same_value) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value).ULEB128(0x3865a760).FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0x3865a760))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x2c).ULEB128(0x9f6).FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x2c, kCFARegister, 0x9f6 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset_extended) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x402b)
+      .ULEB128(0xb48)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x402b, kCFARegister, 0xb48 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_offset_extended_sf) {
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset_extended_sf)
+      .ULEB128(0x997c23ee)
+      .LEB128(0x2d00)
+      .D8(lul::DW_CFA_offset_extended_sf)
+      .ULEB128(0x9519eb82)
+      .LEB128(-0xa77)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x997c23ee, kCFARegister,
+                                  0x2d00 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x9519eb82, kCFARegister,
+                                  -0xa77 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_offset) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x623562fe)
+      .ULEB128(0x673)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x623562fe, kCFARegister,
+                                     0x673 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_offset_sf) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset_sf)
+      .ULEB128(0x6f4f)
+      .LEB128(0xaab)
+      .D8(lul::DW_CFA_val_offset_sf)
+      .ULEB128(0x2483)
+      .LEB128(-0x8a2)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x6f4f, kCFARegister,
+                                     0xaab * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x2483, kCFARegister,
+                                     -0x8a2 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_register) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0x278d18f9)
+      .ULEB128(0x1a684414)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0x278d18f9, 0x1a684414))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_expression) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 8);
+  StockCIEAndFDE(&section);
+  ImageSlice expr("plus ça change, plus c'est la même chose");
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0xa1619fb2)
+      .Block(expr)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0xa1619fb2, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_val_expression) {
+  ByteReader reader(ENDIANNESS_BIG);
+  CFISection section(kBigEndian, 4);
+  ImageSlice expr("he who has the gold makes the rules");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0xc5e4a9e3)
+      .Block(expr)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0xc5e4a9e3, expr))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restore) {
+  CFISection section(kLittleEndian, 8);
+  code_factor = 0x01bd188a9b1fa083ULL;
+  data_factor = -0x1ac8;
+  return_register = 0x8c35b049;
+  version = 2;
+  fde_start = 0x2d70fe998298bbb1ULL;
+  fde_size = 0x46ccc2e63cf0b108ULL;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "")
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x6ca1d50e)
+      .ULEB128(0x372e38e8)
+      // Provide an offset(N) rule for register 0x3c.
+      .D8(lul::DW_CFA_offset | 0x3c)
+      .ULEB128(0xb348)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide a new offset(N) rule for register 0x3c.
+      .D8(lul::DW_CFA_advance_loc | 0x13)
+      .D8(lul::DW_CFA_offset | 0x3c)
+      .ULEB128(0x9a50)
+      // At a third address, restore the original rule for register 0x3c.
+      .D8(lul::DW_CFA_advance_loc | 0x01)
+      .D8(lul::DW_CFA_restore | 0x3c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x6ca1d50e, 0x372e38e8))
+        .WillOnce(Return(true));
+    // CIE's rule for register 0x3c.
+    EXPECT_CALL(handler,
+                OffsetRule(fde_start, 0x3c, kCFARegister, 0xb348 * data_factor))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x3c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x13 * code_factor, 0x3c,
+                                    kCFARegister, 0x9a50 * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's rule for register 0x3c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + (0x13 + 0x01) * code_factor,
+                                    0x3c, kCFARegister, 0xb348 * data_factor))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restoreNoRule) {
+  CFISection section(kBigEndian, 4);
+  code_factor = 0x005f78143c1c3b82ULL;
+  data_factor = 0x25d0;
+  return_register = 0xe8;
+  version = 1;
+  fde_start = 0x4062e30f;
+  fde_size = 0x5302a389;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "")
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x470aa334)
+      .ULEB128(0x099ef127)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide an offset(N) rule for register 0x2c.
+      .D8(lul::DW_CFA_advance_loc | 0x7)
+      .D8(lul::DW_CFA_offset | 0x2c)
+      .ULEB128(0x1f47)
+      // At a third address, restore the (missing) CIE rule for register 0x2c.
+      .D8(lul::DW_CFA_advance_loc | 0xb)
+      .D8(lul::DW_CFA_restore | 0x2c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x470aa334, 0x099ef127))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x2c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x7 * code_factor, 0x2c,
+                                    kCFARegister, 0x1f47 * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's (missing) rule for register 0x2c.
+    EXPECT_CALL(handler,
+                SameValueRule(fde_start + (0x7 + 0xb) * code_factor, 0x2c))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_restore_extended) {
+  CFISection section(kBigEndian, 4);
+  code_factor = 0x126e;
+  data_factor = -0xd8b;
+  return_register = 0x77711787;
+  version = 3;
+  fde_start = 0x01f55a45;
+  fde_size = 0x452adb80;
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(code_factor, data_factor, return_register, version, "",
+                 true /* dwarf64 */)
+      // Provide a CFA rule, because register rules require them.
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x56fa0edd)
+      .ULEB128(0x097f78a5)
+      // Provide an offset(N) rule for register 0x0f9b8a1c.
+      .D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x0f9b8a1c)
+      .ULEB128(0xc979)
+      .FinishEntry()
+      // In the FDE...
+      .FDEHeader(cie, fde_start, fde_size)
+      // At a second address, provide a new offset(N) rule for reg 0x0f9b8a1c.
+      .D8(lul::DW_CFA_advance_loc | 0x3)
+      .D8(lul::DW_CFA_offset_extended)
+      .ULEB128(0x0f9b8a1c)
+      .ULEB128(0x3b7b)
+      // At a third address, restore the original rule for register 0x0f9b8a1c.
+      .D8(lul::DW_CFA_advance_loc | 0x04)
+      .D8(lul::DW_CFA_restore_extended)
+      .ULEB128(0x0f9b8a1c)
+      .FinishEntry();
+
+  {
+    InSequence s;
+    EXPECT_CALL(handler,
+                Entry(_, fde_start, fde_size, version, "", return_register))
+        .WillOnce(Return(true));
+    // CIE's CFA rule.
+    EXPECT_CALL(handler,
+                ValOffsetRule(fde_start, kCFARegister, 0x56fa0edd, 0x097f78a5))
+        .WillOnce(Return(true));
+    // CIE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler, OffsetRule(fde_start, 0x0f9b8a1c, kCFARegister,
+                                    0xc979 * data_factor))
+        .WillOnce(Return(true));
+    // FDE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler, OffsetRule(fde_start + 0x3 * code_factor, 0x0f9b8a1c,
+                                    kCFARegister, 0x3b7b * data_factor))
+        .WillOnce(Return(true));
+    // Restore CIE's rule for register 0x0f9b8a1c.
+    EXPECT_CALL(handler,
+                OffsetRule(fde_start + (0x3 + 0x4) * code_factor, 0x0f9b8a1c,
+                           kCFARegister, 0xc979 * data_factor))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_remember_and_restore_state) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+
+  // We create a state, save it, modify it, and then restore. We
+  // refer to the state that is overridden the restore as the
+  // "outgoing" state, and the restored state the "incoming" state.
+  //
+  // Register         outgoing        incoming        expect
+  // 1                offset(N)       no rule         new "same value" rule
+  // 2                register(R)     offset(N)       report changed rule
+  // 3                offset(N)       offset(M)       report changed offset
+  // 4                offset(N)       offset(N)       no report
+  // 5                offset(N)       no rule         new "same value" rule
+  section
+      // Create the "incoming" state, which we will save and later restore.
+      .D8(lul::DW_CFA_offset | 2)
+      .ULEB128(0x9806)
+      .D8(lul::DW_CFA_offset | 3)
+      .ULEB128(0x995d)
+      .D8(lul::DW_CFA_offset | 4)
+      .ULEB128(0x7055)
+      .D8(lul::DW_CFA_remember_state)
+      // Advance to a new instruction; an implementation could legitimately
+      // ignore all but the final rule for a given register at a given address.
+      .D8(lul::DW_CFA_advance_loc | 1)
+      // Create the "outgoing" state, which we will discard.
+      .D8(lul::DW_CFA_offset | 1)
+      .ULEB128(0xea1a)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(2)
+      .ULEB128(0x1d2a3767)
+      .D8(lul::DW_CFA_offset | 3)
+      .ULEB128(0xdd29)
+      .D8(lul::DW_CFA_offset | 5)
+      .ULEB128(0xf1ce)
+      // At a third address, restore the incoming state.
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  uint64 addr = fde_start;
+
+  // Expect the incoming rules to be reported.
+  EXPECT_CALL(handler, OffsetRule(addr, 2, kCFARegister, 0x9806 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0x995d * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 4, kCFARegister, 0x7055 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  addr += code_factor;
+
+  // After the save, we establish the outgoing rule set.
+  EXPECT_CALL(handler, OffsetRule(addr, 1, kCFARegister, 0xea1a * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, RegisterRule(addr, 2, 0x1d2a3767))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0xdd29 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 5, kCFARegister, 0xf1ce * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  addr += code_factor;
+
+  // Finally, after the restore, expect to see the differences from
+  // the outgoing to the incoming rules reported.
+  EXPECT_CALL(handler, SameValueRule(addr, 1))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 2, kCFARegister, 0x9806 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(addr, 3, kCFARegister, 0x995d * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(addr, 5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// Check that restoring a rule set reports changes to the CFA rule.
+TEST_F(LulDwarfCFIInsn, DW_CFA_remember_and_restore_stateCFA) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+
+  section.D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_def_cfa_offset)
+      .ULEB128(0x90481102)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor, kCFARegister,
+                                     cfa_base_register, 0x90481102))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor * 2, kCFARegister,
+                                     cfa_base_register, cfa_offset))
+      .InSequence(s)
+      .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_nop) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_nop)
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x3fb8d4f1)
+      .ULEB128(0x078dc67b)
+      .D8(lul::DW_CFA_nop)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              ValOffsetRule(fde_start, kCFARegister, 0x3fb8d4f1, 0x078dc67b))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_window_save) {
+  CFISection section(kBigEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_window_save).FinishEntry();
+
+  // Don't include all the rules in any particular sequence.
+
+  // The caller's %o0-%o7 have become the callee's %i0-%i7. This is
+  // the GCC register numbering.
+  for (int i = 8; i < 16; i++)
+    EXPECT_CALL(handler, RegisterRule(fde_start, i, i + 16))
+        .WillOnce(Return(true));
+  // The caller's %l0-%l7 and %i0-%i7 have been saved at the top of
+  // its frame.
+  for (int i = 16; i < 32; i++)
+    EXPECT_CALL(handler, OffsetRule(fde_start, i, kCFARegister, (i - 16) * 4))
+        .WillOnce(Return(true));
+
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_args_size) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_args_size)
+      .ULEB128(0xeddfa520)
+      // Verify that we see this, meaning we parsed the above properly.
+      .D8(lul::DW_CFA_offset | 0x23)
+      .ULEB128(0x269)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x23, kCFARegister, 0x269 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIInsn, DW_CFA_GNU_negative_offset_extended) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_GNU_negative_offset_extended)
+      .ULEB128(0x430cc87a)
+      .ULEB128(0x613)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, OffsetRule(fde_start, 0x430cc87a, kCFARegister,
+                                  -0x613 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+// Three FDEs: skip the second
+TEST_F(LulDwarfCFIInsn, SkipFDE) {
+  CFISection section(kBigEndian, 4);
+  Label cie;
+  section
+      // CIE, used by all FDEs.
+      .Mark(&cie)
+      .CIEHeader(0x010269f2, 0x9177, 0xedca5849, 2, "")
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(0x42ed390b)
+      .ULEB128(0x98f43aad)
+      .FinishEntry()
+      // First FDE.
+      .FDEHeader(cie, 0xa870ebdd, 0x60f6aa4)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x3a860351)
+      .ULEB128(0x6c9a6bcf)
+      .FinishEntry()
+      // Second FDE.
+      .FDEHeader(cie, 0xc534f7c0, 0xf6552e9, true /* dwarf64 */)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x1b62c234)
+      .ULEB128(0x26586b18)
+      .FinishEntry()
+      // Third FDE.
+      .FDEHeader(cie, 0xf681cfc8, 0x7e4594e)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0x26c53934)
+      .ULEB128(0x18eeb8a4)
+      .FinishEntry();
+
+  {
+    InSequence s;
+
+    // Process the first FDE.
+    EXPECT_CALL(handler, Entry(_, 0xa870ebdd, 0x60f6aa4, 2, "", 0xedca5849))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler,
+                ValOffsetRule(0xa870ebdd, kCFARegister, 0x42ed390b, 0x98f43aad))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, RegisterRule(0xa870ebdd, 0x3a860351, 0x6c9a6bcf))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+    // Skip the second FDE.
+    EXPECT_CALL(handler, Entry(_, 0xc534f7c0, 0xf6552e9, 2, "", 0xedca5849))
+        .WillOnce(Return(false));
+
+    // Process the third FDE.
+    EXPECT_CALL(handler, Entry(_, 0xf681cfc8, 0x7e4594e, 2, "", 0xedca5849))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler,
+                ValOffsetRule(0xf681cfc8, kCFARegister, 0x42ed390b, 0x98f43aad))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, RegisterRule(0xf681cfc8, 0x26c53934, 0x18eeb8a4))
+        .WillOnce(Return(true));
+    EXPECT_CALL(handler, End()).WillOnce(Return(true));
+  }
+
+  ParseSection(&section);
+}
+
+// Quit processing in the middle of an entry's instructions.
+TEST_F(LulDwarfCFIInsn, QuitMidentry) {
+  CFISection section(kLittleEndian, 8);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xe0cf850d)
+      .ULEB128(0x15aab431)
+      .D8(lul::DW_CFA_expression)
+      .ULEB128(0x46750aa5)
+      .Block("meat")
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xe0cf850d, 0x15aab431))
+      .InSequence(s)
+      .WillOnce(Return(false));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseSection(&section, false);
+}
+
+class LulDwarfCFIRestore : public CFIInsnFixture, public Test {};
+
+TEST_F(LulDwarfCFIRestore, RestoreUndefinedRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined)
+      .ULEB128(0x0bac878e)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x0bac878e))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreUndefinedRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_undefined)
+      .ULEB128(0x7dedff5f)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_same_value)
+      .ULEB128(0x7dedff5f)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, UndefinedRule(fde_start, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(fde_start + code_factor, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + 2 * code_factor, 0x7dedff5f))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreSameValueRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value)
+      .ULEB128(0xadbc9b3a)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0xadbc9b3a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreSameValueRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_same_value)
+      .ULEB128(0x3d90dcb5)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x3d90dcb5)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, SameValueRule(fde_start, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SameValueRule(fde_start + 2 * code_factor, 0x3d90dcb5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x14)
+      .ULEB128(0xb6f)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x14, kCFARegister, 0xb6f * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0xeb7)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x21)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x21, kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0x21))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + 2 * code_factor, 0x21,
+                                  kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreOffsetRuleChangedOffset) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0x134)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_offset | 0x21)
+      .ULEB128(0xf4f)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler,
+              OffsetRule(fde_start, 0x21, kCFARegister, 0x134 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + code_factor, 0x21, kCFARegister,
+                                  0xf4f * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, OffsetRule(fde_start + 2 * code_factor, 0x21,
+                                  kCFARegister, 0x134 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x829caee6)
+      .ULEB128(0xe4c)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x829caee6, kCFARegister,
+                                     0xe4c * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0xf17c36d6)
+      .ULEB128(0xeb7)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xf17c36d6)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0xf17c36d6, kCFARegister,
+                                     0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xf17c36d6))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 2 * code_factor, 0xf17c36d6,
+                                     kCFARegister, 0xeb7 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValOffsetRuleChangedValOffset) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x2cf0ab1b)
+      .ULEB128(0x562)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_val_offset)
+      .ULEB128(0x2cf0ab1b)
+      .ULEB128(0xe88)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValOffsetRule(fde_start, 0x2cf0ab1b, kCFARegister,
+                                     0x562 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + code_factor, 0x2cf0ab1b,
+                                     kCFARegister, 0xe88 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(fde_start + 2 * code_factor, 0x2cf0ab1b,
+                                     kCFARegister, 0x562 * data_factor))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleUnchanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0x77514acc)
+      .ULEB128(0x464de4ce)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0x77514acc, 0x464de4ce))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleChanged) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xe39acce5)
+      .ULEB128(0x095f1559)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xe39acce5)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xe39acce5, 0x095f1559))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xe39acce5))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + 2 * code_factor, 0xe39acce5, 0x095f1559))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreRegisterRuleChangedRegister) {
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_register)
+      .ULEB128(0xd40e21b1)
+      .ULEB128(0x16607d6a)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(0xd40e21b1)
+      .ULEB128(0xbabb4742)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, RegisterRule(fde_start, 0xd40e21b1, 0x16607d6a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + code_factor, 0xd40e21b1, 0xbabb4742))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              RegisterRule(fde_start + 2 * code_factor, 0xd40e21b1, 0x16607d6a))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleUnchanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice dwarf("dwarf");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0x666ae152)
+      .Block("dwarf")
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0x666ae152, dwarf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleChanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice elf("elf");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0xb5ca5c46)
+      .Block(elf)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xb5ca5c46)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0xb5ca5c46, elf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xb5ca5c46))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              ExpressionRule(fde_start + 2 * code_factor, 0xb5ca5c46, elf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreExpressionRuleChangedExpression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  StockCIEAndFDE(&section);
+  ImageSlice smurf("smurf");
+  ImageSlice orc("orc");
+  section.D8(lul::DW_CFA_expression)
+      .ULEB128(0x500f5739)
+      .Block(smurf)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_expression)
+      .ULEB128(0x500f5739)
+      .Block(orc)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ExpressionRule(fde_start, 0x500f5739, smurf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ExpressionRule(fde_start + code_factor, 0x500f5739, orc))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  // Expectations are not wishes.
+  EXPECT_CALL(handler,
+              ExpressionRule(fde_start + 2 * code_factor, 0x500f5739, smurf))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleUnchanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice hideous("hideous");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x666ae152)
+      .Block(hideous)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0x666ae152, hideous))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleChanged) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice revolting("revolting");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0xb5ca5c46)
+      .Block(revolting)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0xb5ca5c46)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("RestoreValExpressionRuleChanged", section);
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0xb5ca5c46, revolting))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(fde_start + code_factor, 0xb5ca5c46))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValExpressionRule(fde_start + 2 * code_factor,
+                                         0xb5ca5c46, revolting))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+TEST_F(LulDwarfCFIRestore, RestoreValExpressionRuleChangedValExpression) {
+  ByteReader reader(ENDIANNESS_LITTLE);
+  CFISection section(kLittleEndian, 4);
+  ImageSlice repulsive("repulsive");
+  ImageSlice nauseous("nauseous");
+  StockCIEAndFDE(&section);
+  section.D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x500f5739)
+      .Block(repulsive)
+      .D8(lul::DW_CFA_remember_state)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_val_expression)
+      .ULEB128(0x500f5739)
+      .Block(nauseous)
+      .D8(lul::DW_CFA_advance_loc | 1)
+      .D8(lul::DW_CFA_restore_state)
+      .FinishEntry();
+
+  PERHAPS_WRITE_DEBUG_FRAME_FILE("RestoreValExpressionRuleChangedValExpression",
+                                 section);
+
+  EXPECT_CALL(handler, ValExpressionRule(fde_start, 0x500f5739, repulsive))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler,
+              ValExpressionRule(fde_start + code_factor, 0x500f5739, nauseous))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  // Expectations are not wishes.
+  EXPECT_CALL(handler, ValExpressionRule(fde_start + 2 * code_factor,
+                                         0x500f5739, repulsive))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).WillOnce(Return(true));
+
+  ParseSection(&section, true, &reader);
+}
+
+struct EHFrameFixture : public CFIInsnFixture {
+  EHFrameFixture() : CFIInsnFixture(), section(kBigEndian, 4, true) {
+    encoded_pointer_bases.cfi = 0x7f496cb2;
+    encoded_pointer_bases.text = 0x540f67b6;
+    encoded_pointer_bases.data = 0xe3eab768;
+    section.SetEncodedPointerBases(encoded_pointer_bases);
+  }
+  CFISection section;
+  CFISection::EncodedPointerBases encoded_pointer_bases;
+
+  // Parse CFIInsnFixture::ParseSection, but parse the section as
+  // .eh_frame data, supplying stock base addresses.
+  void ParseEHFrameSection(CFISection* section, bool succeeds = true) {
+    EXPECT_TRUE(section->ContainsEHFrame());
+    string contents;
+    EXPECT_TRUE(section->GetContents(&contents));
+    lul::Endianness endianness;
+    if (section->endianness() == kBigEndian)
+      endianness = ENDIANNESS_BIG;
+    else {
+      assert(section->endianness() == kLittleEndian);
+      endianness = ENDIANNESS_LITTLE;
+    }
+    ByteReader reader(endianness);
+    reader.SetAddressSize(section->AddressSize());
+    reader.SetCFIDataBase(encoded_pointer_bases.cfi, contents.data());
+    reader.SetTextBase(encoded_pointer_bases.text);
+    reader.SetDataBase(encoded_pointer_bases.data);
+    CallFrameInfo parser(contents.data(), contents.size(), &reader, &handler,
+                         &reporter, true);
+    if (succeeds)
+      EXPECT_TRUE(parser.Start());
+    else
+      EXPECT_FALSE(parser.Start());
+  }
+};
+
+class LulDwarfEHFrame : public EHFrameFixture, public Test {};
+
+// A simple CIE, an FDE, and a terminator.
+TEST_F(LulDwarfEHFrame, Terminator) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(9968, 2466, 67, 1, "")
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(3772)
+      .ULEB128(1372)
+      .FinishEntry()
+      .FDEHeader(cie, 0x848037a1, 0x7b30475e)
+      .D8(lul::DW_CFA_set_loc)
+      .D32(0x17713850)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(5721)
+      .FinishEntry()
+      .D32(0)  // Terminate the sequence.
+      // This FDE should be ignored.
+      .FDEHeader(cie, 0xf19629fe, 0x439fb09b)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.Terminator", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x848037a1, 0x7b30475e, 1, "", 67))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0x848037a1, kCFARegister, 3772, 1372))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0x17713850, 5721))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(reporter, EarlyEHTerminator(_)).InSequence(s).WillOnce(Return());
+
+  ParseEHFrameSection(&section);
+}
+
+// The parser should recognize the Linux Standards Base 'z' augmentations.
+TEST_F(LulDwarfEHFrame, SimpleFDE) {
+  lul::DwarfPointerEncoding lsda_encoding = lul::DwarfPointerEncoding(
+      lul::DW_EH_PE_indirect | lul::DW_EH_PE_datarel | lul::DW_EH_PE_sdata2);
+  lul::DwarfPointerEncoding fde_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_textrel | lul::DW_EH_PE_udata2);
+
+  section.SetPointerEncoding(fde_encoding);
+  section.SetEncodedPointerBases(encoded_pointer_bases);
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(4873, 7012, 100, 1, "zSLPR")
+      .ULEB128(7)               // Augmentation data length
+      .D8(lsda_encoding)        // LSDA pointer format
+      .D8(lul::DW_EH_PE_pcrel)  // personality pointer format
+      .EncodedPointer(0x97baa00, lul::DW_EH_PE_pcrel)  // and value
+      .D8(fde_encoding)                                // FDE pointer format
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(6706)
+      .ULEB128(31)
+      .FinishEntry()
+      .FDEHeader(cie, 0x540f6b56, 0xf686)
+      .ULEB128(2)                                 // Augmentation data length
+      .EncodedPointer(0xe3eab475, lsda_encoding)  // LSDA pointer, signed
+      .D8(lul::DW_CFA_set_loc)
+      .EncodedPointer(0x540fa4ce, fde_encoding)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(0x675e)
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.SimpleFDE", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x540f6b56, 0xf686, 1, "zSLPR", 100))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, PersonalityRoutine(0x97baa00, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, LanguageSpecificDataArea(0xe3eab475, true))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SignalHandler()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0x540f6b56, kCFARegister, 6706, 31))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0x540fa4ce, 0x675e))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// Check that we can handle an empty 'z' augmentation.
+TEST_F(LulDwarfEHFrame, EmptyZ) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(5955, 5805, 228, 1, "z")
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(3629)
+      .ULEB128(247)
+      .FinishEntry()
+      .FDEHeader(cie, 0xda007738, 0xfb55c641)
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_advance_loc1)
+      .D8(11)
+      .D8(lul::DW_CFA_undefined)
+      .ULEB128(3769)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.EmptyZ", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xda007738, 0xfb55c641, 1, "z", 228))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, ValOffsetRule(0xda007738, kCFARegister, 3629, 247))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, UndefinedRule(0xda007738 + 11 * 5955, 3769))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// Check that we recognize bad 'z' augmentation characters.
+TEST_F(LulDwarfEHFrame, BadZ) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(6937, 1045, 142, 1, "zQ")
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_def_cfa)
+      .ULEB128(9006)
+      .ULEB128(7725)
+      .FinishEntry()
+      .FDEHeader(cie, 0x1293efa8, 0x236f53f2)
+      .ULEB128(0)  // Augmentation data length
+      .D8(lul::DW_CFA_advance_loc | 12)
+      .D8(lul::DW_CFA_register)
+      .ULEB128(5667)
+      .ULEB128(3462)
+      .FinishEntry();
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.BadZ", section);
+
+  EXPECT_CALL(reporter, UnrecognizedAugmentation(_, "zQ")).WillOnce(Return());
+
+  ParseEHFrameSection(&section, false);
+}
+
+TEST_F(LulDwarfEHFrame, zL) {
+  Label cie;
+  lul::DwarfPointerEncoding lsda_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_funcrel | lul::DW_EH_PE_udata2);
+  section.Mark(&cie)
+      .CIEHeader(9285, 9959, 54, 1, "zL")
+      .ULEB128(1)         // Augmentation data length
+      .D8(lsda_encoding)  // encoding for LSDA pointer in FDE
+
+      .FinishEntry()
+      .FDEHeader(cie, 0xd40091aa, 0x9aa6e746)
+      .ULEB128(2)                                 // Augmentation data length
+      .EncodedPointer(0xd40099cd, lsda_encoding)  // LSDA pointer
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zL", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xd40091aa, 0x9aa6e746, 1, "zL", 54))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, LanguageSpecificDataArea(0xd40099cd, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zP) {
+  Label cie;
+  lul::DwarfPointerEncoding personality_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_datarel | lul::DW_EH_PE_udata2);
+  section.Mark(&cie)
+      .CIEHeader(1097, 6313, 17, 1, "zP")
+      .ULEB128(3)                // Augmentation data length
+      .D8(personality_encoding)  // encoding for personality routine
+      .EncodedPointer(0xe3eaccac, personality_encoding)  // value
+      .FinishEntry()
+      .FDEHeader(cie, 0x0c8350c9, 0xbef11087)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zP", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x0c8350c9, 0xbef11087, 1, "zP", 17))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, PersonalityRoutine(0xe3eaccac, false))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zR) {
+  Label cie;
+  lul::DwarfPointerEncoding pointer_encoding =
+      lul::DwarfPointerEncoding(lul::DW_EH_PE_textrel | lul::DW_EH_PE_sdata2);
+  section.SetPointerEncoding(pointer_encoding);
+  section.Mark(&cie)
+      .CIEHeader(8011, 5496, 75, 1, "zR")
+      .ULEB128(1)            // Augmentation data length
+      .D8(pointer_encoding)  // encoding for FDE addresses
+      .FinishEntry()
+      .FDEHeader(cie, 0x540f9431, 0xbd0)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zR", section);
+
+  EXPECT_CALL(handler, Entry(_, 0x540f9431, 0xbd0, 1, "zR", 75))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+TEST_F(LulDwarfEHFrame, zS) {
+  Label cie;
+  section.Mark(&cie)
+      .CIEHeader(9217, 7694, 57, 1, "zS")
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .FDEHeader(cie, 0xd40091aa, 0x9aa6e746)
+      .ULEB128(0)  // Augmentation data length
+      .FinishEntry()
+      .D32(0);  // terminator
+
+  PERHAPS_WRITE_EH_FRAME_FILE("EHFrame.zS", section);
+
+  EXPECT_CALL(handler, Entry(_, 0xd40091aa, 0x9aa6e746, 1, "zS", 57))
+      .InSequence(s)
+      .WillOnce(Return(true));
+  EXPECT_CALL(handler, SignalHandler()).InSequence(s).WillOnce(Return(true));
+  EXPECT_CALL(handler, End()).InSequence(s).WillOnce(Return(true));
+
+  ParseEHFrameSection(&section);
+}
+
+// These tests require manual inspection of the test output.
+struct CFIReporterFixture {
+  CFIReporterFixture()
+      : reporter(gtest_logging_sink_for_LulTestDwarf, "test file name",
+                 "test section name") {}
+  CallFrameInfo::Reporter reporter;
+};
+
+class LulDwarfCFIReporter : public CFIReporterFixture, public Test {};
+
+TEST_F(LulDwarfCFIReporter, Incomplete) {
+  reporter.Incomplete(0x0102030405060708ULL, CallFrameInfo::kUnknown);
+}
+
+TEST_F(LulDwarfCFIReporter, EarlyEHTerminator) {
+  reporter.EarlyEHTerminator(0x0102030405060708ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, CIEPointerOutOfRange) {
+  reporter.CIEPointerOutOfRange(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, BadCIEId) {
+  reporter.BadCIEId(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, UnrecognizedVersion) {
+  reporter.UnrecognizedVersion(0x0123456789abcdefULL, 43);
+}
+
+TEST_F(LulDwarfCFIReporter, UnrecognizedAugmentation) {
+  reporter.UnrecognizedAugmentation(0x0123456789abcdefULL, "poodles");
+}
+
+TEST_F(LulDwarfCFIReporter, InvalidPointerEncoding) {
+  reporter.InvalidPointerEncoding(0x0123456789abcdefULL, 0x42);
+}
+
+TEST_F(LulDwarfCFIReporter, UnusablePointerEncoding) {
+  reporter.UnusablePointerEncoding(0x0123456789abcdefULL, 0x42);
+}
+
+TEST_F(LulDwarfCFIReporter, RestoreInCIE) {
+  reporter.RestoreInCIE(0x0123456789abcdefULL, 0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, BadInstruction) {
+  reporter.BadInstruction(0x0123456789abcdefULL, CallFrameInfo::kFDE,
+                          0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, NoCFARule) {
+  reporter.NoCFARule(0x0123456789abcdefULL, CallFrameInfo::kCIE,
+                     0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, EmptyStateStack) {
+  reporter.EmptyStateStack(0x0123456789abcdefULL, CallFrameInfo::kTerminator,
+                           0xfedcba9876543210ULL);
+}
+
+TEST_F(LulDwarfCFIReporter, ClearingCFARule) {
+  reporter.ClearingCFARule(0x0123456789abcdefULL, CallFrameInfo::kFDE,
+                           0xfedcba9876543210ULL);
+}
+class LulDwarfExpr : public Test {};
+
+class MockSummariser : public Summariser {
+ public:
+  MockSummariser() : Summariser(nullptr, 0, nullptr) {}
+  MOCK_METHOD2(Entry, void(uintptr_t, uintptr_t));
+  MOCK_METHOD0(End, void());
+  MOCK_METHOD5(Rule, void(uintptr_t, int, LExprHow, int16_t, int64_t));
+  MOCK_METHOD1(AddPfxInstr, uint32_t(PfxInstr));
+};
+
+TEST_F(LulDwarfExpr, SimpleTransliteration) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_lit0)
+      .D8(DW_OP_lit31)
+      .D8(DW_OP_breg0 + 17)
+      .LEB128(-1234)
+      .D8(DW_OP_const4s)
+      .D32(0xFEDC9876)
+      .D8(DW_OP_deref)
+      .D8(DW_OP_and)
+      .D8(DW_OP_plus)
+      .D8(DW_OP_minus)
+      .D8(DW_OP_shl)
+      .D8(DW_OP_ge);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+    // DW_OP_lit0
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 0)));
+    // DW_OP_lit31
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 31)));
+    // DW_OP_breg17 -1234
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_DwReg, 17)));
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, -1234)));
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Add)));
+    // DW_OP_const4s 0xFEDC9876
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_SImm32, 0xFEDC9876)));
+    // DW_OP_deref
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Deref)));
+    // DW_OP_and
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_And)));
+    // DW_OP_plus
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Add)));
+    // DW_OP_minus
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Sub)));
+    // DW_OP_shl
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Shl)));
+    // DW_OP_ge
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_CmpGES)));
+    // required end marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_End)));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix >= 0);
+}
+
+TEST_F(LulDwarfExpr, UnknownOpcode) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_lo_user - 1);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix == -1);
+}
+
+TEST_F(LulDwarfExpr, ExpressionOverrun) {
+  MockSummariser summ;
+  ByteReader reader(ENDIANNESS_LITTLE);
+
+  CFISection section(kLittleEndian, 8);
+  section.D8(DW_OP_const4s).D8(0x12).D8(0x34).D8(0x56);
+  string expr;
+  bool ok = section.GetContents(&expr);
+  EXPECT_TRUE(ok);
+
+  {
+    InSequence s;
+    // required start marker
+    EXPECT_CALL(summ, AddPfxInstr(PfxInstr(PX_Start, 0)));
+    // DW_OP_const4s followed by 3 (a.k.a. not enough) bytes
+    // We expect PfxInstr(PX_Simm32, not-known-for-sure-32-bit-immediate)
+    // Hence must use _ as the argument.
+    EXPECT_CALL(summ, AddPfxInstr(_));
+  }
+
+  int32_t ix =
+      parseDwarfExpr(&summ, &reader, ImageSlice(expr), false, false, false);
+  EXPECT_TRUE(ix == -1);
+}
+
+// We'll need to mention specific Dwarf registers in the EvaluatePfxExpr tests,
+// and those names are arch-specific, so a bit of macro magic is helpful.
+#if defined(GP_ARCH_arm)
+#  define TESTED_REG_STRUCT_NAME r11
+#  define TESTED_REG_DWARF_NAME DW_REG_ARM_R11
+#elif defined(GP_ARCH_arm64)
+#  define TESTED_REG_STRUCT_NAME x29
+#  define TESTED_REG_DWARF_NAME DW_REG_AARCH64_X29
+#elif defined(GP_ARCH_amd64) || defined(GP_ARCH_x86)
+#  define TESTED_REG_STRUCT_NAME xbp
+#  define TESTED_REG_DWARF_NAME DW_REG_INTEL_XBP
+#else
+#  error "Unknown plat"
+#endif
+
+struct EvaluatePfxExprFixture {
+  // Creates:
+  // initial stack, AVMA 0x12345678, at offset 4 bytes = 0xdeadbeef
+  // initial regs, with XBP = 0x14141356
+  // initial CFA = 0x5432ABCD
+  EvaluatePfxExprFixture() {
+    // The test stack.
+    si.mStartAvma = 0x12345678;
+    si.mLen = 0;
+#define XX(_byte)                      \
+  do {                                 \
+    si.mContents[si.mLen++] = (_byte); \
+  } while (0)
+    XX(0x55);
+    XX(0x55);
+    XX(0x55);
+    XX(0x55);
+    if (sizeof(void*) == 8) {
+      // le64
+      XX(0xEF);
+      XX(0xBE);
+      XX(0xAD);
+      XX(0xDE);
+      XX(0);
+      XX(0);
+      XX(0);
+      XX(0);
+    } else {
+      // le32
+      XX(0xEF);
+      XX(0xBE);
+      XX(0xAD);
+      XX(0xDE);
+    }
+    XX(0xAA);
+    XX(0xAA);
+    XX(0xAA);
+    XX(0xAA);
+#undef XX
+    // The initial CFA.
+    initialCFA = TaggedUWord(0x5432ABCD);
+    // The initial register state.
+    memset(&regs, 0, sizeof(regs));
+    regs.TESTED_REG_STRUCT_NAME = TaggedUWord(0x14141356);
+  }
+
+  StackImage si;
+  TaggedUWord initialCFA;
+  UnwindRegs regs;
+};
+
+class LulDwarfEvaluatePfxExpr : public EvaluatePfxExprFixture, public Test {};
+
+TEST_F(LulDwarfEvaluatePfxExpr, NormalEvaluation) {
+  vector<PfxInstr> instrs;
+  // Put some junk at the start of the insn sequence.
+  instrs.push_back(PfxInstr(PX_End));
+  instrs.push_back(PfxInstr(PX_End));
+
+  // Now the real sequence
+  // stack is empty
+  instrs.push_back(PfxInstr(PX_Start, 1));
+  // 0x5432ABCD
+  instrs.push_back(PfxInstr(PX_SImm32, 0x31415927));
+  // 0x5432ABCD 0x31415927
+  instrs.push_back(PfxInstr(PX_DwReg, TESTED_REG_DWARF_NAME));
+  // 0x5432ABCD 0x31415927 0x14141356
+  instrs.push_back(PfxInstr(PX_SImm32, 42));
+  // 0x5432ABCD 0x31415927 0x14141356 42
+  instrs.push_back(PfxInstr(PX_Sub));
+  // 0x5432ABCD 0x31415927 0x1414132c
+  instrs.push_back(PfxInstr(PX_Add));
+  // 0x5432ABCD 0x45556c53
+  instrs.push_back(PfxInstr(PX_SImm32, si.mStartAvma + 4));
+  // 0x5432ABCD 0x45556c53 0x1234567c
+  instrs.push_back(PfxInstr(PX_Deref));
+  // 0x5432ABCD 0x45556c53 0xdeadbeef
+  instrs.push_back(PfxInstr(PX_SImm32, 0xFE01DC23));
+  // 0x5432ABCD 0x45556c53 0xdeadbeef 0xFE01DC23
+  instrs.push_back(PfxInstr(PX_And));
+  // 0x5432ABCD 0x45556c53 0xde019c23
+  instrs.push_back(PfxInstr(PX_SImm32, 7));
+  // 0x5432ABCD 0x45556c53 0xde019c23 7
+  instrs.push_back(PfxInstr(PX_Shl));
+  // 0x5432ABCD 0x45556c53 0x6f00ce1180
+  instrs.push_back(PfxInstr(PX_SImm32, 0x7fffffff));
+  // 0x5432ABCD 0x45556c53 0x6f00ce1180 7fffffff
+  instrs.push_back(PfxInstr(PX_And));
+  // 0x5432ABCD 0x45556c53 0x00ce1180
+  instrs.push_back(PfxInstr(PX_Add));
+  // 0x5432ABCD 0x46237dd3
+  instrs.push_back(PfxInstr(PX_Sub));
+  // 0xe0f2dfa
+
+  instrs.push_back(PfxInstr(PX_End));
+
+  TaggedUWord res = EvaluatePfxExpr(2 /*offset of start insn*/, &regs,
+                                    initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res.Value() == 0xe0f2dfa);
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, EmptySequence) {
+  vector<PfxInstr> instrs;
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, BogusStartPoint) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_SImm32, 42));
+  instrs.push_back(PfxInstr(PX_SImm32, 24));
+  instrs.push_back(PfxInstr(PX_SImm32, 4224));
+  TaggedUWord res = EvaluatePfxExpr(1, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, MissingEndMarker) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_SImm32, 24));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackUnderflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackNoUnderflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 1 /*push the initial CFA*/));
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == initialCFA);
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackOverflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  for (int i = 0; i < 10 + 1; i++) {
+    instrs.push_back(PfxInstr(PX_SImm32, i + 100));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_FALSE(res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, StackNoOverflow) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  for (int i = 0; i < 10 + 0; i++) {
+    instrs.push_back(PfxInstr(PX_SImm32, i + 100));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == TaggedUWord(109));
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, OutOfRangeShl) {
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  instrs.push_back(PfxInstr(PX_SImm32, 1234));
+  instrs.push_back(PfxInstr(PX_SImm32, 5678));
+  instrs.push_back(PfxInstr(PX_Shl));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(!res.Valid());
+}
+
+TEST_F(LulDwarfEvaluatePfxExpr, TestCmpGES) {
+  const int32_t argsL[6] = {0, 0, 1, -2, -1, -2};
+  const int32_t argsR[6] = {0, 1, 0, -2, -2, -1};
+  // expecting:              t  f  t  t   t    f   = 101110 = 0x2E
+  vector<PfxInstr> instrs;
+  instrs.push_back(PfxInstr(PX_Start, 0));
+  // The "running total"
+  instrs.push_back(PfxInstr(PX_SImm32, 0));
+  for (unsigned int i = 0; i < sizeof(argsL) / sizeof(argsL[0]); i++) {
+    // Shift the "running total" at the bottom of the stack left by one bit
+    instrs.push_back(PfxInstr(PX_SImm32, 1));
+    instrs.push_back(PfxInstr(PX_Shl));
+    // Push both test args and do the comparison
+    instrs.push_back(PfxInstr(PX_SImm32, argsL[i]));
+    instrs.push_back(PfxInstr(PX_SImm32, argsR[i]));
+    instrs.push_back(PfxInstr(PX_CmpGES));
+    // Or the result into the running total
+    instrs.push_back(PfxInstr(PX_Or));
+  }
+  instrs.push_back(PfxInstr(PX_End));
+  TaggedUWord res = EvaluatePfxExpr(0, &regs, initialCFA, &si, instrs);
+  EXPECT_TRUE(res.Valid());
+  EXPECT_TRUE(res == TaggedUWord(0x2E));
+}
+
+}  // namespace lul
diff --git a/tools/profiler/tests/gtest/LulTestInfrastructure.cpp b/tools/profiler/tests/gtest/LulTestInfrastructure.cpp
new file mode 100644
index 0000000000..6d49557e9c
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestInfrastructure.cpp
@@ -0,0 +1,498 @@
+// Copyright (c) 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Derived from:
+// test_assembler.cc: Implementation of google_breakpad::TestAssembler.
+// See test_assembler.h for details.
+
+// Derived from:
+// cfi_assembler.cc: Implementation of google_breakpad::CFISection class.
+// See cfi_assembler.h for details.
+
+#include "LulTestInfrastructure.h"
+
+#include "LulDwarfInt.h"
+
+#include <cassert>
+
+namespace lul_test {
+namespace test_assembler {
+
+using std::back_insert_iterator;
+
+Label::Label() : value_(new Binding()) {}
+Label::Label(uint64_t value) : value_(new Binding(value)) {}
+Label::Label(const Label& label) {
+  value_ = label.value_;
+  value_->Acquire();
+}
+Label::~Label() {
+  if (value_->Release()) delete value_;
+}
+
+Label& Label::operator=(uint64_t value) {
+  value_->Set(NULL, value);
+  return *this;
+}
+
+Label& Label::operator=(const Label& label) {
+  value_->Set(label.value_, 0);
+  return *this;
+}
+
+Label Label::operator+(uint64_t addend) const {
+  Label l;
+  l.value_->Set(this->value_, addend);
+  return l;
+}
+
+Label Label::operator-(uint64_t subtrahend) const {
+  Label l;
+  l.value_->Set(this->value_, -subtrahend);
+  return l;
+}
+
+// When NDEBUG is #defined, assert doesn't evaluate its argument. This
+// means you can't simply use assert to check the return value of a
+// function with necessary side effects.
+//
+// ALWAYS_EVALUATE_AND_ASSERT(x) evaluates x regardless of whether
+// NDEBUG is #defined; when NDEBUG is not #defined, it further asserts
+// that x is true.
+#ifdef NDEBUG
+#  define ALWAYS_EVALUATE_AND_ASSERT(x) x
+#else
+#  define ALWAYS_EVALUATE_AND_ASSERT(x) assert(x)
+#endif
+
+uint64_t Label::operator-(const Label& label) const {
+  uint64_t offset;
+  ALWAYS_EVALUATE_AND_ASSERT(IsKnownOffsetFrom(label, &offset));
+  return offset;
+}
+
+bool Label::IsKnownConstant(uint64_t* value_p) const {
+  Binding* base;
+  uint64_t addend;
+  value_->Get(&base, &addend);
+  if (base != NULL) return false;
+  if (value_p) *value_p = addend;
+  return true;
+}
+
+bool Label::IsKnownOffsetFrom(const Label& label, uint64_t* offset_p) const {
+  Binding *label_base, *this_base;
+  uint64_t label_addend, this_addend;
+  label.value_->Get(&label_base, &label_addend);
+  value_->Get(&this_base, &this_addend);
+  // If this and label are related, Get will find their final
+  // common ancestor, regardless of how indirect the relation is. This
+  // comparison also handles the constant vs. constant case.
+  if (this_base != label_base) return false;
+  if (offset_p) *offset_p = this_addend - label_addend;
+  return true;
+}
+
+Label::Binding::Binding() : base_(this), addend_(), reference_count_(1) {}
+
+Label::Binding::Binding(uint64_t addend)
+    : base_(NULL), addend_(addend), reference_count_(1) {}
+
+Label::Binding::~Binding() {
+  assert(reference_count_ == 0);
+  if (base_ && base_ != this && base_->Release()) delete base_;
+}
+
+void Label::Binding::Set(Binding* binding, uint64_t addend) {
+  if (!base_ && !binding) {
+    // We're equating two constants. This could be okay.
+    assert(addend_ == addend);
+  } else if (!base_) {
+    // We are a known constant, but BINDING may not be, so turn the
+    // tables and try to set BINDING's value instead.
+    binding->Set(NULL, addend_ - addend);
+  } else {
+    if (binding) {
+      // Find binding's final value. Since the final value is always either
+      // completely unconstrained or a constant, never a reference to
+      // another variable (otherwise, it wouldn't be final), this
+      // guarantees we won't create cycles here, even for code like this:
+      //   l = m, m = n, n = l;
+      uint64_t binding_addend;
+      binding->Get(&binding, &binding_addend);
+      addend += binding_addend;
+    }
+
+    // It seems likely that setting a binding to itself is a bug
+    // (although I can imagine this might turn out to be helpful to
+    // permit).
+    assert(binding != this);
+
+    if (base_ != this) {
+      // Set the other bindings on our chain as well. Note that this
+      // is sufficient even though binding relationships form trees:
+      // All binding operations traverse their chains to the end, and
+      // all bindings related to us share some tail of our chain, so
+      // they will see the changes we make here.
+      base_->Set(binding, addend - addend_);
+      // We're not going to use base_ any more.
+      if (base_->Release()) delete base_;
+    }
+
+    // Adopt BINDING as our base. Note that it should be correct to
+    // acquire here, after the release above, even though the usual
+    // reference-counting rules call for acquiring first, and then
+    // releasing: the self-reference assertion above should have
+    // complained if BINDING were 'this' or anywhere along our chain,
+    // so we didn't release BINDING.
+    if (binding) binding->Acquire();
+    base_ = binding;
+    addend_ = addend;
+  }
+}
+
+void Label::Binding::Get(Binding** base, uint64_t* addend) {
+  if (base_ && base_ != this) {
+    // Recurse to find the end of our reference chain (the root of our
+    // tree), and then rewrite every binding along the chain to refer
+    // to it directly, adjusting addends appropriately. (This is why
+    // this member function isn't this-const.)
+    Binding* final_base;
+    uint64_t final_addend;
+    base_->Get(&final_base, &final_addend);
+    if (final_base) final_base->Acquire();
+    if (base_->Release()) delete base_;
+    base_ = final_base;
+    addend_ += final_addend;
+  }
+  *base = base_;
+  *addend = addend_;
+}
+
+template <typename Inserter>
+static inline void InsertEndian(test_assembler::Endianness endianness,
+                                size_t size, uint64_t number, Inserter dest) {
+  assert(size > 0);
+  if (endianness == kLittleEndian) {
+    for (size_t i = 0; i < size; i++) {
+      *dest++ = (char)(number & 0xff);
+      number >>= 8;
+    }
+  } else {
+    assert(endianness == kBigEndian);
+    // The loop condition is odd, but it's correct for size_t.
+    for (size_t i = size - 1; i < size; i--)
+      *dest++ = (char)((number >> (i * 8)) & 0xff);
+  }
+}
+
+Section& Section::Append(Endianness endianness, size_t size, uint64_t number) {
+  InsertEndian(endianness, size, number,
+               back_insert_iterator<string>(contents_));
+  return *this;
+}
+
+Section& Section::Append(Endianness endianness, size_t size,
+                         const Label& label) {
+  // If this label's value is known, there's no reason to waste an
+  // entry in references_ on it.
+  uint64_t value;
+  if (label.IsKnownConstant(&value)) return Append(endianness, size, value);
+
+  // This will get caught when the references are resolved, but it's
+  // nicer to find out earlier.
+  assert(endianness != kUnsetEndian);
+
+  references_.push_back(Reference(contents_.size(), endianness, size, label));
+  contents_.append(size, 0);
+  return *this;
+}
+
+#define ENDIANNESS_L kLittleEndian
+#define ENDIANNESS_B kBigEndian
+#define ENDIANNESS(e) ENDIANNESS_##e
+
+#define DEFINE_SHORT_APPEND_NUMBER_ENDIAN(e, bits)         \
+  Section& Section::e##bits(uint##bits##_t v) {            \
+    InsertEndian(ENDIANNESS(e), bits / 8, v,               \
+                 back_insert_iterator<string>(contents_)); \
+    return *this;                                          \
+  }
+
+#define DEFINE_SHORT_APPEND_LABEL_ENDIAN(e, bits) \
+  Section& Section::e##bits(const Label& v) {     \
+    return Append(ENDIANNESS(e), bits / 8, v);    \
+  }
+
+// Define L16, B32, and friends.
+#define DEFINE_SHORT_APPEND_ENDIAN(e, bits)  \
+  DEFINE_SHORT_APPEND_NUMBER_ENDIAN(e, bits) \
+  DEFINE_SHORT_APPEND_LABEL_ENDIAN(e, bits)
+
+DEFINE_SHORT_APPEND_LABEL_ENDIAN(L, 8);
+DEFINE_SHORT_APPEND_LABEL_ENDIAN(B, 8);
+DEFINE_SHORT_APPEND_ENDIAN(L, 16);
+DEFINE_SHORT_APPEND_ENDIAN(L, 32);
+DEFINE_SHORT_APPEND_ENDIAN(L, 64);
+DEFINE_SHORT_APPEND_ENDIAN(B, 16);
+DEFINE_SHORT_APPEND_ENDIAN(B, 32);
+DEFINE_SHORT_APPEND_ENDIAN(B, 64);
+
+#define DEFINE_SHORT_APPEND_NUMBER_DEFAULT(bits)           \
+  Section& Section::D##bits(uint##bits##_t v) {            \
+    InsertEndian(endianness_, bits / 8, v,                 \
+                 back_insert_iterator<string>(contents_)); \
+    return *this;                                          \
+  }
+#define DEFINE_SHORT_APPEND_LABEL_DEFAULT(bits) \
+  Section& Section::D##bits(const Label& v) {   \
+    return Append(endianness_, bits / 8, v);    \
+  }
+#define DEFINE_SHORT_APPEND_DEFAULT(bits)  \
+  DEFINE_SHORT_APPEND_NUMBER_DEFAULT(bits) \
+  DEFINE_SHORT_APPEND_LABEL_DEFAULT(bits)
+
+DEFINE_SHORT_APPEND_LABEL_DEFAULT(8)
+DEFINE_SHORT_APPEND_DEFAULT(16);
+DEFINE_SHORT_APPEND_DEFAULT(32);
+DEFINE_SHORT_APPEND_DEFAULT(64);
+
+Section& Section::LEB128(long long value) {
+  while (value < -0x40 || 0x3f < value) {
+    contents_ += (value & 0x7f) | 0x80;
+    if (value < 0)
+      value = (value >> 7) | ~(((unsigned long long)-1) >> 7);
+    else
+      value = (value >> 7);
+  }
+  contents_ += value & 0x7f;
+  return *this;
+}
+
+Section& Section::ULEB128(uint64_t value) {
+  while (value > 0x7f) {
+    contents_ += (value & 0x7f) | 0x80;
+    value = (value >> 7);
+  }
+  contents_ += value;
+  return *this;
+}
+
+Section& Section::Align(size_t alignment, uint8_t pad_byte) {
+  // ALIGNMENT must be a power of two.
+  assert(((alignment - 1) & alignment) == 0);
+  size_t new_size = (contents_.size() + alignment - 1) & ~(alignment - 1);
+  contents_.append(new_size - contents_.size(), pad_byte);
+  assert((contents_.size() & (alignment - 1)) == 0);
+  return *this;
+}
+
+bool Section::GetContents(string* contents) {
+  // For each label reference, find the label's value, and patch it into
+  // the section's contents.
+  for (size_t i = 0; i < references_.size(); i++) {
+    Reference& r = references_[i];
+    uint64_t value;
+    if (!r.label.IsKnownConstant(&value)) {
+      fprintf(stderr, "Undefined label #%zu at offset 0x%zx\n", i, r.offset);
+      return false;
+    }
+    assert(r.offset < contents_.size());
+    assert(contents_.size() - r.offset >= r.size);
+    InsertEndian(r.endianness, r.size, value, contents_.begin() + r.offset);
+  }
+  contents->clear();
+  std::swap(contents_, *contents);
+  references_.clear();
+  return true;
+}
+
+}  // namespace test_assembler
+}  // namespace lul_test
+
+namespace lul_test {
+
+CFISection& CFISection::CIEHeader(uint64_t code_alignment_factor,
+                                  int data_alignment_factor,
+                                  unsigned return_address_register,
+                                  uint8_t version, const string& augmentation,
+                                  bool dwarf64) {
+  assert(!entry_length_);
+  entry_length_ = new PendingLength();
+  in_fde_ = false;
+
+  if (dwarf64) {
+    D32(kDwarf64InitialLengthMarker);
+    D64(entry_length_->length);
+    entry_length_->start = Here();
+    D64(eh_frame_ ? kEHFrame64CIEIdentifier : kDwarf64CIEIdentifier);
+  } else {
+    D32(entry_length_->length);
+    entry_length_->start = Here();
+    D32(eh_frame_ ? kEHFrame32CIEIdentifier : kDwarf32CIEIdentifier);
+  }
+  D8(version);
+  AppendCString(augmentation);
+  ULEB128(code_alignment_factor);
+  LEB128(data_alignment_factor);
+  if (version == 1)
+    D8(return_address_register);
+  else
+    ULEB128(return_address_register);
+  return *this;
+}
+
+CFISection& CFISection::FDEHeader(Label cie_pointer, uint64_t initial_location,
+                                  uint64_t address_range, bool dwarf64) {
+  assert(!entry_length_);
+  entry_length_ = new PendingLength();
+  in_fde_ = true;
+  fde_start_address_ = initial_location;
+
+  if (dwarf64) {
+    D32(0xffffffff);
+    D64(entry_length_->length);
+    entry_length_->start = Here();
+    if (eh_frame_)
+      D64(Here() - cie_pointer);
+    else
+      D64(cie_pointer);
+  } else {
+    D32(entry_length_->length);
+    entry_length_->start = Here();
+    if (eh_frame_)
+      D32(Here() - cie_pointer);
+    else
+      D32(cie_pointer);
+  }
+  EncodedPointer(initial_location);
+  // The FDE length in an .eh_frame section uses the same encoding as the
+  // initial location, but ignores the base address (selected by the upper
+  // nybble of the encoding), as it's a length, not an address that can be
+  // made relative.
+  EncodedPointer(address_range, DwarfPointerEncoding(pointer_encoding_ & 0x0f));
+  return *this;
+}
+
+CFISection& CFISection::FinishEntry() {
+  assert(entry_length_);
+  Align(address_size_, lul::DW_CFA_nop);
+  entry_length_->length = Here() - entry_length_->start;
+  delete entry_length_;
+  entry_length_ = NULL;
+  in_fde_ = false;
+  return *this;
+}
+
+CFISection& CFISection::EncodedPointer(uint64_t address,
+                                       DwarfPointerEncoding encoding,
+                                       const EncodedPointerBases& bases) {
+  // Omitted data is extremely easy to emit.
+  if (encoding == lul::DW_EH_PE_omit) return *this;
+
+  // If (encoding & lul::DW_EH_PE_indirect) != 0, then we assume
+  // that ADDRESS is the address at which the pointer is stored --- in
+  // other words, that bit has no effect on how we write the pointer.
+  encoding = DwarfPointerEncoding(encoding & ~lul::DW_EH_PE_indirect);
+
+  // Find the base address to which this pointer is relative. The upper
+  // nybble of the encoding specifies this.
+  uint64_t base;
+  switch (encoding & 0xf0) {
+    case lul::DW_EH_PE_absptr:
+      base = 0;
+      break;
+    case lul::DW_EH_PE_pcrel:
+      base = bases.cfi + Size();
+      break;
+    case lul::DW_EH_PE_textrel:
+      base = bases.text;
+      break;
+    case lul::DW_EH_PE_datarel:
+      base = bases.data;
+      break;
+    case lul::DW_EH_PE_funcrel:
+      base = fde_start_address_;
+      break;
+    case lul::DW_EH_PE_aligned:
+      base = 0;
+      break;
+    default:
+      abort();
+  };
+
+  // Make ADDRESS relative. Yes, this is appropriate even for "absptr"
+  // values; see gcc/unwind-pe.h.
+  address -= base;
+
+  // Align the pointer, if required.
+  if ((encoding & 0xf0) == lul::DW_EH_PE_aligned) Align(AddressSize());
+
+  // Append ADDRESS to this section in the appropriate form. For the
+  // fixed-width forms, we don't need to differentiate between signed and
+  // unsigned encodings, because ADDRESS has already been extended to 64
+  // bits before it was passed to us.
+  switch (encoding & 0x0f) {
+    case lul::DW_EH_PE_absptr:
+      Address(address);
+      break;
+
+    case lul::DW_EH_PE_uleb128:
+      ULEB128(address);
+      break;
+
+    case lul::DW_EH_PE_sleb128:
+      LEB128(address);
+      break;
+
+    case lul::DW_EH_PE_udata2:
+    case lul::DW_EH_PE_sdata2:
+      D16(address);
+      break;
+
+    case lul::DW_EH_PE_udata4:
+    case lul::DW_EH_PE_sdata4:
+      D32(address);
+      break;
+
+    case lul::DW_EH_PE_udata8:
+    case lul::DW_EH_PE_sdata8:
+      D64(address);
+      break;
+
+    default:
+      abort();
+  }
+
+  return *this;
+};
+
+}  // namespace lul_test
diff --git a/tools/profiler/tests/gtest/LulTestInfrastructure.h b/tools/profiler/tests/gtest/LulTestInfrastructure.h
new file mode 100644
index 0000000000..9faa7ca858
--- /dev/null
+++ b/tools/profiler/tests/gtest/LulTestInfrastructure.h
@@ -0,0 +1,736 @@
+// -*- mode: C++ -*-
+
+// Copyright (c) 2010, Google Inc.
+// All rights reserved.
+//
+// Redistribution and use in source and binary forms, with or without
+// modification, are permitted provided that the following conditions are
+// met:
+//
+//     * Redistributions of source code must retain the above copyright
+// notice, this list of conditions and the following disclaimer.
+//     * Redistributions in binary form must reproduce the above
+// copyright notice, this list of conditions and the following disclaimer
+// in the documentation and/or other materials provided with the
+// distribution.
+//     * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived from
+// this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+// Original author: Jim Blandy <jimb@mozilla.com> <jimb@red-bean.com>
+
+// Derived from:
+// cfi_assembler.h: Define CFISection, a class for creating properly
+// (and improperly) formatted DWARF CFI data for unit tests.
+
+// Derived from:
+// test-assembler.h: interface to class for building complex binary streams.
+
+// To test the Breakpad symbol dumper and processor thoroughly, for
+// all combinations of host system and minidump processor
+// architecture, we need to be able to easily generate complex test
+// data like debugging information and minidump files.
+//
+// For example, if we want our unit tests to provide full code
+// coverage for stack walking, it may be difficult to persuade the
+// compiler to generate every possible sort of stack walking
+// information that we want to support; there are probably DWARF CFI
+// opcodes that GCC never emits. Similarly, if we want to test our
+// error handling, we will need to generate damaged minidumps or
+// debugging information that (we hope) the client or compiler will
+// never produce on its own.
+//
+// google_breakpad::TestAssembler provides a predictable and
+// (relatively) simple way to generate complex formatted data streams
+// like minidumps and CFI. Furthermore, because TestAssembler is
+// portable, developers without access to (say) Visual Studio or a
+// SPARC assembler can still work on test data for those targets.
+
+#ifndef LUL_TEST_INFRASTRUCTURE_H
+#define LUL_TEST_INFRASTRUCTURE_H
+
+#include "LulDwarfExt.h"
+
+#include <string>
+#include <vector>
+
+using std::string;
+using std::vector;
+
+namespace lul_test {
+namespace test_assembler {
+
+// A Label represents a value not yet known that we need to store in a
+// section. As long as all the labels a section refers to are defined
+// by the time we retrieve its contents as bytes, we can use undefined
+// labels freely in that section's construction.
+//
+// A label can be in one of three states:
+// - undefined,
+// - defined as the sum of some other label and a constant, or
+// - a constant.
+//
+// A label's value never changes, but it can accumulate constraints.
+// Adding labels and integers is permitted, and yields a label.
+// Subtracting a constant from a label is permitted, and also yields a
+// label. Subtracting two labels that have some relationship to each
+// other is permitted, and yields a constant.
+//
+// For example:
+//
+//   Label a;               // a's value is undefined
+//   Label b;               // b's value is undefined
+//   {
+//     Label c = a + 4;     // okay, even though a's value is unknown
+//     b = c + 4;           // also okay; b is now a+8
+//   }
+//   Label d = b - 2;       // okay; d == a+6, even though c is gone
+//   d.Value();             // error: d's value is not yet known
+//   d - a;                 // is 6, even though their values are not known
+//   a = 12;                // now b == 20, and d == 18
+//   d.Value();             // 18: no longer an error
+//   b.Value();             // 20
+//   d = 10;                // error: d is already defined.
+//
+// Label objects' lifetimes are unconstrained: notice that, in the
+// above example, even though a and b are only related through c, and
+// c goes out of scope, the assignment to a sets b's value as well. In
+// particular, it's not necessary to ensure that a Label lives beyond
+// Sections that refer to it.
+class Label {
+ public:
+  Label();                         // An undefined label.
+  explicit Label(uint64_t value);  // A label with a fixed value
+  Label(const Label& value);       // A label equal to another.
+  ~Label();
+
+  Label& operator=(uint64_t value);
+  Label& operator=(const Label& value);
+  Label operator+(uint64_t addend) const;
+  Label operator-(uint64_t subtrahend) const;
+  uint64_t operator-(const Label& subtrahend) const;
+
+  // We could also provide == and != that work on undefined, but
+  // related, labels.
+
+  // Return true if this label's value is known. If VALUE_P is given,
+  // set *VALUE_P to the known value if returning true.
+  bool IsKnownConstant(uint64_t* value_p = NULL) const;
+
+  // Return true if the offset from LABEL to this label is known. If
+  // OFFSET_P is given, set *OFFSET_P to the offset when returning true.
+  //
+  // You can think of l.KnownOffsetFrom(m, &d) as being like 'd = l-m',
+  // except that it also returns a value indicating whether the
+  // subtraction is possible given what we currently know of l and m.
+  // It can be possible even if we don't know l and m's values. For
+  // example:
+  //
+  //   Label l, m;
+  //   m = l + 10;
+  //   l.IsKnownConstant();             // false
+  //   m.IsKnownConstant();             // false
+  //   uint64_t d;
+  //   l.IsKnownOffsetFrom(m, &d);      // true, and sets d to -10.
+  //   l-m                              // -10
+  //   m-l                              // 10
+  //   m.Value()                        // error: m's value is not known
+  bool IsKnownOffsetFrom(const Label& label, uint64_t* offset_p = NULL) const;
+
+ private:
+  // A label's value, or if that is not yet known, how the value is
+  // related to other labels' values. A binding may be:
+  // - a known constant,
+  // - constrained to be equal to some other binding plus a constant, or
+  // - unconstrained, and free to take on any value.
+  //
+  // Many labels may point to a single binding, and each binding may
+  // refer to another, so bindings and labels form trees whose leaves
+  // are labels, whose interior nodes (and roots) are bindings, and
+  // where links point from children to parents. Bindings are
+  // reference counted, allowing labels to be lightweight, copyable,
+  // assignable, placed in containers, and so on.
+  class Binding {
+   public:
+    Binding();
+    explicit Binding(uint64_t addend);
+    ~Binding();
+
+    // Increment our reference count.
+    void Acquire() { reference_count_++; };
+    // Decrement our reference count, and return true if it is zero.
+    bool Release() { return --reference_count_ == 0; }
+
+    // Set this binding to be equal to BINDING + ADDEND. If BINDING is
+    // NULL, then set this binding to the known constant ADDEND.
+    // Update every binding on this binding's chain to point directly
+    // to BINDING, or to be a constant, with addends adjusted
+    // appropriately.
+    void Set(Binding* binding, uint64_t value);
+
+    // Return what we know about the value of this binding.
+    // - If this binding's value is a known constant, set BASE to
+    //   NULL, and set ADDEND to its value.
+    // - If this binding is not a known constant but related to other
+    //   bindings, set BASE to the binding at the end of the relation
+    //   chain (which will always be unconstrained), and set ADDEND to the
+    //   value to add to that binding's value to get this binding's
+    //   value.
+    // - If this binding is unconstrained, set BASE to this, and leave
+    //   ADDEND unchanged.
+    void Get(Binding** base, uint64_t* addend);
+
+   private:
+    // There are three cases:
+    //
+    // - A binding representing a known constant value has base_ NULL,
+    //   and addend_ equal to the value.
+    //
+    // - A binding representing a completely unconstrained value has
+    //   base_ pointing to this; addend_ is unused.
+    //
+    // - A binding whose value is related to some other binding's
+    //   value has base_ pointing to that other binding, and addend_
+    //   set to the amount to add to that binding's value to get this
+    //   binding's value. We only represent relationships of the form
+    //   x = y+c.
+    //
+    // Thus, the bind_ links form a chain terminating in either a
+    // known constant value or a completely unconstrained value. Most
+    // operations on bindings do path compression: they change every
+    // binding on the chain to point directly to the final value,
+    // adjusting addends as appropriate.
+    Binding* base_;
+    uint64_t addend_;
+
+    // The number of Labels and Bindings pointing to this binding.
+    // (When a binding points to itself, indicating a completely
+    // unconstrained binding, that doesn't count as a reference.)
+    int reference_count_;
+  };
+
+  // This label's value.
+  Binding* value_;
+};
+
+// Conventions for representing larger numbers as sequences of bytes.
+enum Endianness {
+  kBigEndian,     // Big-endian: the most significant byte comes first.
+  kLittleEndian,  // Little-endian: the least significant byte comes first.
+  kUnsetEndian,   // used internally
+};
+
+// A section is a sequence of bytes, constructed by appending bytes
+// to the end. Sections have a convenient and flexible set of member
+// functions for appending data in various formats: big-endian and
+// little-endian signed and unsigned values of different sizes;
+// LEB128 and ULEB128 values (see below), and raw blocks of bytes.
+//
+// If you need to append a value to a section that is not convenient
+// to compute immediately, you can create a label, append the
+// label's value to the section, and then set the label's value
+// later, when it's convenient to do so. Once a label's value is
+// known, the section class takes care of updating all previously
+// appended references to it.
+//
+// Once all the labels to which a section refers have had their
+// values determined, you can get a copy of the section's contents
+// as a string.
+//
+// Note that there is no specified "start of section" label. This is
+// because there are typically several different meanings for "the
+// start of a section": the offset of the section within an object
+// file, the address in memory at which the section's content appear,
+// and so on. It's up to the code that uses the Section class to
+// keep track of these explicitly, as they depend on the application.
+class Section {
+ public:
+  explicit Section(Endianness endianness = kUnsetEndian)
+      : endianness_(endianness){};
+
+  // A base class destructor should be either public and virtual,
+  // or protected and nonvirtual.
+  virtual ~Section(){};
+
+  // Return the default endianness of this section.
+  Endianness endianness() const { return endianness_; }
+
+  // Append the SIZE bytes at DATA to the end of this section. Return
+  // a reference to this section.
+  Section& Append(const string& data) {
+    contents_.append(data);
+    return *this;
+  };
+
+  // Append data from SLICE to the end of this section. Return
+  // a reference to this section.
+  Section& Append(const lul::ImageSlice& slice) {
+    for (size_t i = 0; i < slice.length_; i++) {
+      contents_.append(1, slice.start_[i]);
+    }
+    return *this;
+  }
+
+  // Append data from CSTRING to the end of this section.  The terminating
+  // zero is not included.  Return a reference to this section.
+  Section& Append(const char* cstring) {
+    for (size_t i = 0; cstring[i] != '\0'; i++) {
+      contents_.append(1, cstring[i]);
+    }
+    return *this;
+  }
+
+  // Append SIZE copies of BYTE to the end of this section. Return a
+  // reference to this section.
+  Section& Append(size_t size, uint8_t byte) {
+    contents_.append(size, (char)byte);
+    return *this;
+  }
+
+  // Append NUMBER to this section. ENDIANNESS is the endianness to
+  // use to write the number. SIZE is the length of the number in
+  // bytes. Return a reference to this section.
+  Section& Append(Endianness endianness, size_t size, uint64_t number);
+  Section& Append(Endianness endianness, size_t size, const Label& label);
+
+  // Append SECTION to the end of this section. The labels SECTION
+  // refers to need not be defined yet.
+  //
+  // Note that this has no effect on any Labels' values, or on
+  // SECTION. If placing SECTION within 'this' provides new
+  // constraints on existing labels' values, then it's up to the
+  // caller to fiddle with those labels as needed.
+  Section& Append(const Section& section);
+
+  // Append the contents of DATA as a series of bytes terminated by
+  // a NULL character.
+  Section& AppendCString(const string& data) {
+    Append(data);
+    contents_ += '\0';
+    return *this;
+  }
+
+  // Append VALUE or LABEL to this section, with the given bit width and
+  // endianness. Return a reference to this section.
+  //
+  // The names of these functions have the form <ENDIANNESS><BITWIDTH>:
+  // <ENDIANNESS> is either 'L' (little-endian, least significant byte first),
+  //                        'B' (big-endian, most significant byte first), or
+  //                        'D' (default, the section's default endianness)
+  // <BITWIDTH> is 8, 16, 32, or 64.
+  //
+  // Since endianness doesn't matter for a single byte, all the
+  // <BITWIDTH>=8 functions are equivalent.
+  //
+  // These can be used to write both signed and unsigned values, as
+  // the compiler will properly sign-extend a signed value before
+  // passing it to the function, at which point the function's
+  // behavior is the same either way.
+  Section& L8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section& B8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section& D8(uint8_t value) {
+    contents_ += value;
+    return *this;
+  }
+  Section &L16(uint16_t), &L32(uint32_t), &L64(uint64_t), &B16(uint16_t),
+      &B32(uint32_t), &B64(uint64_t), &D16(uint16_t), &D32(uint32_t),
+      &D64(uint64_t);
+  Section &L8(const Label& label), &L16(const Label& label),
+      &L32(const Label& label), &L64(const Label& label),
+      &B8(const Label& label), &B16(const Label& label),
+      &B32(const Label& label), &B64(const Label& label),
+      &D8(const Label& label), &D16(const Label& label),
+      &D32(const Label& label), &D64(const Label& label);
+
+  // Append VALUE in a signed LEB128 (Little-Endian Base 128) form.
+  //
+  // The signed LEB128 representation of an integer N is a variable
+  // number of bytes:
+  //
+  // - If N is between -0x40 and 0x3f, then its signed LEB128
+  //   representation is a single byte whose value is N.
+  //
+  // - Otherwise, its signed LEB128 representation is (N & 0x7f) |
+  //   0x80, followed by the signed LEB128 representation of N / 128,
+  //   rounded towards negative infinity.
+  //
+  // In other words, we break VALUE into groups of seven bits, put
+  // them in little-endian order, and then write them as eight-bit
+  // bytes with the high bit on all but the last.
+  //
+  // Note that VALUE cannot be a Label (we would have to implement
+  // relaxation).
+  Section& LEB128(long long value);
+
+  // Append VALUE in unsigned LEB128 (Little-Endian Base 128) form.
+  //
+  // The unsigned LEB128 representation of an integer N is a variable
+  // number of bytes:
+  //
+  // - If N is between 0 and 0x7f, then its unsigned LEB128
+  //   representation is a single byte whose value is N.
+  //
+  // - Otherwise, its unsigned LEB128 representation is (N & 0x7f) |
+  //   0x80, followed by the unsigned LEB128 representation of N /
+  //   128, rounded towards negative infinity.
+  //
+  // Note that VALUE cannot be a Label (we would have to implement
+  // relaxation).
+  Section& ULEB128(uint64_t value);
+
+  // Jump to the next location aligned on an ALIGNMENT-byte boundary,
+  // relative to the start of the section. Fill the gap with PAD_BYTE.
+  // ALIGNMENT must be a power of two. Return a reference to this
+  // section.
+  Section& Align(size_t alignment, uint8_t pad_byte = 0);
+
+  // Return the current size of the section.
+  size_t Size() const { return contents_.size(); }
+
+  // Return a label representing the start of the section.
+  //
+  // It is up to the user whether this label represents the section's
+  // position in an object file, the section's address in memory, or
+  // what have you; some applications may need both, in which case
+  // this simple-minded interface won't be enough. This class only
+  // provides a single start label, for use with the Here and Mark
+  // member functions.
+  //
+  // Ideally, we'd provide this in a subclass that actually knows more
+  // about the application at hand and can provide an appropriate
+  // collection of start labels. But then the appending member
+  // functions like Append and D32 would return a reference to the
+  // base class, not the derived class, and the chaining won't work.
+  // Since the only value here is in pretty notation, that's a fatal
+  // flaw.
+  Label start() const { return start_; }
+
+  // Return a label representing the point at which the next Appended
+  // item will appear in the section, relative to start().
+  Label Here() const { return start_ + Size(); }
+
+  // Set *LABEL to Here, and return a reference to this section.
+  Section& Mark(Label* label) {
+    *label = Here();
+    return *this;
+  }
+
+  // If there are no undefined label references left in this
+  // section, set CONTENTS to the contents of this section, as a
+  // string, and clear this section. Return true on success, or false
+  // if there were still undefined labels.
+  bool GetContents(string* contents);
+
+ private:
+  // Used internally. A reference to a label's value.
+  struct Reference {
+    Reference(size_t set_offset, Endianness set_endianness, size_t set_size,
+              const Label& set_label)
+        : offset(set_offset),
+          endianness(set_endianness),
+          size(set_size),
+          label(set_label) {}
+
+    // The offset of the reference within the section.
+    size_t offset;
+
+    // The endianness of the reference.
+    Endianness endianness;
+
+    // The size of the reference.
+    size_t size;
+
+    // The label to which this is a reference.
+    Label label;
+  };
+
+  // The default endianness of this section.
+  Endianness endianness_;
+
+  // The contents of the section.
+  string contents_;
+
+  // References to labels within those contents.
+  vector<Reference> references_;
+
+  // A label referring to the beginning of the section.
+  Label start_;
+};
+
+}  // namespace test_assembler
+}  // namespace lul_test
+
+namespace lul_test {
+
+using lul::DwarfPointerEncoding;
+using lul_test::test_assembler::Endianness;
+using lul_test::test_assembler::Label;
+using lul_test::test_assembler::Section;
+
+class CFISection : public Section {
+ public:
+  // CFI augmentation strings beginning with 'z', defined by the
+  // Linux/IA-64 C++ ABI, can specify interesting encodings for
+  // addresses appearing in FDE headers and call frame instructions (and
+  // for additional fields whose presence the augmentation string
+  // specifies). In particular, pointers can be specified to be relative
+  // to various base address: the start of the .text section, the
+  // location holding the address itself, and so on. These allow the
+  // frame data to be position-independent even when they live in
+  // write-protected pages. These variants are specified at the
+  // following two URLs:
+  //
+  // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/dwarfext.html
+  // http://refspecs.linux-foundation.org/LSB_4.0.0/LSB-Core-generic/LSB-Core-generic/ehframechpt.html
+  //
+  // CFISection leaves the production of well-formed 'z'-augmented CIEs and
+  // FDEs to the user, but does provide EncodedPointer, to emit
+  // properly-encoded addresses for a given pointer encoding.
+  // EncodedPointer uses an instance of this structure to find the base
+  // addresses it should use; you can establish a default for all encoded
+  // pointers appended to this section with SetEncodedPointerBases.
+  struct EncodedPointerBases {
+    EncodedPointerBases() : cfi(), text(), data() {}
+
+    // The starting address of this CFI section in memory, for
+    // DW_EH_PE_pcrel. DW_EH_PE_pcrel pointers may only be used in data
+    // that has is loaded into the program's address space.
+    uint64_t cfi;
+
+    // The starting address of this file's .text section, for DW_EH_PE_textrel.
+    uint64_t text;
+
+    // The starting address of this file's .got or .eh_frame_hdr section,
+    // for DW_EH_PE_datarel.
+    uint64_t data;
+  };
+
+  // Create a CFISection whose endianness is ENDIANNESS, and where
+  // machine addresses are ADDRESS_SIZE bytes long. If EH_FRAME is
+  // true, use the .eh_frame format, as described by the Linux
+  // Standards Base Core Specification, instead of the DWARF CFI
+  // format.
+  CFISection(Endianness endianness, size_t address_size, bool eh_frame = false)
+      : Section(endianness),
+        address_size_(address_size),
+        eh_frame_(eh_frame),
+        pointer_encoding_(lul::DW_EH_PE_absptr),
+        encoded_pointer_bases_(),
+        entry_length_(NULL),
+        in_fde_(false) {
+    // The 'start', 'Here', and 'Mark' members of a CFISection all refer
+    // to section offsets.
+    start() = 0;
+  }
+
+  // Return this CFISection's address size.
+  size_t AddressSize() const { return address_size_; }
+
+  // Return true if this CFISection uses the .eh_frame format, or
+  // false if it contains ordinary DWARF CFI data.
+  bool ContainsEHFrame() const { return eh_frame_; }
+
+  // Use ENCODING for pointers in calls to FDEHeader and EncodedPointer.
+  void SetPointerEncoding(DwarfPointerEncoding encoding) {
+    pointer_encoding_ = encoding;
+  }
+
+  // Use the addresses in BASES as the base addresses for encoded
+  // pointers in subsequent calls to FDEHeader or EncodedPointer.
+  // This function makes a copy of BASES.
+  void SetEncodedPointerBases(const EncodedPointerBases& bases) {
+    encoded_pointer_bases_ = bases;
+  }
+
+  // Append a Common Information Entry header to this section with the
+  // given values. If dwarf64 is true, use the 64-bit DWARF initial
+  // length format for the CIE's initial length. Return a reference to
+  // this section. You should call FinishEntry after writing the last
+  // instruction for the CIE.
+  //
+  // Before calling this function, you will typically want to use Mark
+  // or Here to make a label to pass to FDEHeader that refers to this
+  // CIE's position in the section.
+  CFISection& CIEHeader(uint64_t code_alignment_factor,
+                        int data_alignment_factor,
+                        unsigned return_address_register, uint8_t version = 3,
+                        const string& augmentation = "", bool dwarf64 = false);
+
+  // Append a Frame Description Entry header to this section with the
+  // given values. If dwarf64 is true, use the 64-bit DWARF initial
+  // length format for the CIE's initial length. Return a reference to
+  // this section. You should call FinishEntry after writing the last
+  // instruction for the CIE.
+  //
+  // This function doesn't support entries that are longer than
+  // 0xffffff00 bytes. (The "initial length" is always a 32-bit
+  // value.) Nor does it support .debug_frame sections longer than
+  // 0xffffff00 bytes.
+  CFISection& FDEHeader(Label cie_pointer, uint64_t initial_location,
+                        uint64_t address_range, bool dwarf64 = false);
+
+  // Note the current position as the end of the last CIE or FDE we
+  // started, after padding with DW_CFA_nops for alignment. This
+  // defines the label representing the entry's length, cited in the
+  // entry's header. Return a reference to this section.
+  CFISection& FinishEntry();
+
+  // Append the contents of BLOCK as a DW_FORM_block value: an
+  // unsigned LEB128 length, followed by that many bytes of data.
+  CFISection& Block(const lul::ImageSlice& block) {
+    ULEB128(block.length_);
+    Append(block);
+    return *this;
+  }
+
+  // Append data from CSTRING as a DW_FORM_block value: an unsigned LEB128
+  // length, followed by that many bytes of data. The terminating zero is not
+  // included.
+  CFISection& Block(const char* cstring) {
+    ULEB128(strlen(cstring));
+    Append(cstring);
+    return *this;
+  }
+
+  // Append ADDRESS to this section, in the appropriate size and
+  // endianness. Return a reference to this section.
+  CFISection& Address(uint64_t address) {
+    Section::Append(endianness(), address_size_, address);
+    return *this;
+  }
+
+  // Append ADDRESS to this section, using ENCODING and BASES. ENCODING
+  // defaults to this section's default encoding, established by
+  // SetPointerEncoding. BASES defaults to this section's bases, set by
+  // SetEncodedPointerBases. If the DW_EH_PE_indirect bit is set in the
+  // encoding, assume that ADDRESS is where the true address is stored.
+  // Return a reference to this section.
+  //
+  // (C++ doesn't let me use default arguments here, because I want to
+  // refer to members of *this in the default argument expression.)
+  CFISection& EncodedPointer(uint64_t address) {
+    return EncodedPointer(address, pointer_encoding_, encoded_pointer_bases_);
+  }
+  CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding) {
+    return EncodedPointer(address, encoding, encoded_pointer_bases_);
+  }
+  CFISection& EncodedPointer(uint64_t address, DwarfPointerEncoding encoding,
+                             const EncodedPointerBases& bases);
+
+  // Restate some member functions, to keep chaining working nicely.
+  CFISection& Mark(Label* label) {
+    Section::Mark(label);
+    return *this;
+  }
+  CFISection& D8(uint8_t v) {
+    Section::D8(v);
+    return *this;
+  }
+  CFISection& D16(uint16_t v) {
+    Section::D16(v);
+    return *this;
+  }
+  CFISection& D16(Label v) {
+    Section::D16(v);
+    return *this;
+  }
+  CFISection& D32(uint32_t v) {
+    Section::D32(v);
+    return *this;
+  }
+  CFISection& D32(const Label& v) {
+    Section::D32(v);
+    return *this;
+  }
+  CFISection& D64(uint64_t v) {
+    Section::D64(v);
+    return *this;
+  }
+  CFISection& D64(const Label& v) {
+    Section::D64(v);
+    return *this;
+  }
+  CFISection& LEB128(long long v) {
+    Section::LEB128(v);
+    return *this;
+  }
+  CFISection& ULEB128(uint64_t v) {
+    Section::ULEB128(v);
+    return *this;
+  }
+
+ private:
+  // A length value that we've appended to the section, but is not yet
+  // known. LENGTH is the appended value; START is a label referring
+  // to the start of the data whose length was cited.
+  struct PendingLength {
+    Label length;
+    Label start;
+  };
+
+  // Constants used in CFI/.eh_frame data:
+
+  // If the first four bytes of an "initial length" are this constant, then
+  // the data uses the 64-bit DWARF format, and the length itself is the
+  // subsequent eight bytes.
+  static const uint32_t kDwarf64InitialLengthMarker = 0xffffffffU;
+
+  // The CIE identifier for 32- and 64-bit DWARF CFI and .eh_frame data.
+  static const uint32_t kDwarf32CIEIdentifier = ~(uint32_t)0;
+  static const uint64_t kDwarf64CIEIdentifier = ~(uint64_t)0;
+  static const uint32_t kEHFrame32CIEIdentifier = 0;
+  static const uint64_t kEHFrame64CIEIdentifier = 0;
+
+  // The size of a machine address for the data in this section.
+  size_t address_size_;
+
+  // If true, we are generating a Linux .eh_frame section, instead of
+  // a standard DWARF .debug_frame section.
+  bool eh_frame_;
+
+  // The encoding to use for FDE pointers.
+  DwarfPointerEncoding pointer_encoding_;
+
+  // The base addresses to use when emitting encoded pointers.
+  EncodedPointerBases encoded_pointer_bases_;
+
+  // The length value for the current entry.
+  //
+  // Oddly, this must be dynamically allocated. Labels never get new
+  // values; they only acquire constraints on the value they already
+  // have, or assert if you assign them something incompatible. So
+  // each header needs truly fresh Label objects to cite in their
+  // headers and track their positions. The alternative is explicit
+  // destructor invocation and a placement new. Ick.
+  PendingLength* entry_length_;
+
+  // True if we are currently emitting an FDE --- that is, we have
+  // called FDEHeader but have not yet called FinishEntry.
+  bool in_fde_;
+
+  // If in_fde_ is true, this is its starting address. We use this for
+  // emitting DW_EH_PE_funcrel pointers.
+  uint64_t fde_start_address_;
+};
+
+}  // namespace lul_test
+
+#endif  // LUL_TEST_INFRASTRUCTURE_H
diff --git a/tools/profiler/tests/gtest/ThreadProfileTest.cpp b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
new file mode 100644
index 0000000000..b8a15c39b2
--- /dev/null
+++ b/tools/profiler/tests/gtest/ThreadProfileTest.cpp
@@ -0,0 +1,60 @@
+
+/* -*- 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/. */
+
+#ifdef MOZ_GECKO_PROFILER
+
+#  include "ProfileBuffer.h"
+
+#  include "mozilla/PowerOfTwo.h"
+#  include "mozilla/ProfileBufferChunkManagerWithLocalLimit.h"
+#  include "mozilla/ProfileChunkedBuffer.h"
+
+#  include "gtest/gtest.h"
+
+// Make sure we can record one entry and read it
+TEST(ThreadProfile, InsertOneEntry)
+{
+  mozilla::ProfileBufferChunkManagerWithLocalLimit chunkManager(
+      2 * (1 + uint32_t(sizeof(ProfileBufferEntry))) * 4,
+      2 * (1 + uint32_t(sizeof(ProfileBufferEntry))));
+  mozilla::ProfileChunkedBuffer profileChunkedBuffer(
+      mozilla::ProfileChunkedBuffer::ThreadSafety::WithMutex, chunkManager);
+  auto pb = mozilla::MakeUnique<ProfileBuffer>(profileChunkedBuffer);
+  pb->AddEntry(ProfileBufferEntry::Time(123.1));
+  ProfileBufferEntry entry = pb->GetEntry(pb->BufferRangeStart());
+  ASSERT_TRUE(entry.IsTime());
+  ASSERT_EQ(123.1, entry.GetDouble());
+}
+
+// See if we can insert some entries
+TEST(ThreadProfile, InsertEntriesNoWrap)
+{
+  mozilla::ProfileBufferChunkManagerWithLocalLimit chunkManager(
+      100 * (1 + uint32_t(sizeof(ProfileBufferEntry))),
+      100 * (1 + uint32_t(sizeof(ProfileBufferEntry))) / 4);
+  mozilla::ProfileChunkedBuffer profileChunkedBuffer(
+      mozilla::ProfileChunkedBuffer::ThreadSafety::WithMutex, chunkManager);
+  auto pb = mozilla::MakeUnique<ProfileBuffer>(profileChunkedBuffer);
+  const int test_size = 50;
+  for (int i = 0; i < test_size; i++) {
+    pb->AddEntry(ProfileBufferEntry::Time(i));
+  }
+  int times = 0;
+  uint64_t readPos = pb->BufferRangeStart();
+  while (readPos != pb->BufferRangeEnd()) {
+    ProfileBufferEntry entry = pb->GetEntry(readPos);
+    readPos++;
+    if (entry.GetKind() == ProfileBufferEntry::Kind::INVALID) {
+      continue;
+    }
+    ASSERT_TRUE(entry.IsTime());
+    ASSERT_EQ(times, entry.GetDouble());
+    times++;
+  }
+  ASSERT_EQ(test_size, times);
+}
+
+#endif  // MOZ_GECKO_PROFILER
diff --git a/tools/profiler/tests/gtest/moz.build b/tools/profiler/tests/gtest/moz.build
new file mode 100644
index 0000000000..4eb1fef762
--- /dev/null
+++ b/tools/profiler/tests/gtest/moz.build
@@ -0,0 +1,45 @@
+# -*- Mode: python; indent-tabs-mode: nil; tab-width: 40 -*-
+# vim: set filetype=python:
+# 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/.
+
+if (
+    CONFIG["MOZ_GECKO_PROFILER"]
+    and CONFIG["OS_TARGET"] in ("Android", "Linux")
+    and CONFIG["CPU_ARCH"]
+    in (
+        "arm",
+        "aarch64",
+        "x86",
+        "x86_64",
+    )
+):
+    UNIFIED_SOURCES += [
+        "LulTest.cpp",
+        "LulTestDwarf.cpp",
+        "LulTestInfrastructure.cpp",
+    ]
+
+LOCAL_INCLUDES += [
+    "/netwerk/base",
+    "/netwerk/protocol/http",
+    "/toolkit/components/jsoncpp/include",
+    "/tools/profiler/core",
+    "/tools/profiler/gecko",
+    "/tools/profiler/lul",
+]
+
+if CONFIG["OS_TARGET"] != "Android":
+    UNIFIED_SOURCES += [
+        "GeckoProfiler.cpp",
+        "ThreadProfileTest.cpp",
+    ]
+
+USE_LIBS += [
+    "jsoncpp",
+]
+
+include("/ipc/chromium/chromium-config.mozbuild")
+
+FINAL_LIBRARY = "xul-gtest"