Adding upstream version 124.0.1.upstream/124.0.1

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

9 files changed, 708 insertions, 0 deletions

diff --git a/tools/fuzzing/interface/FuzzingInterface.cpp b/tools/fuzzing/interface/FuzzingInterface.cpp
new file mode 100644
index 0000000000..f06ca68656
--- /dev/null
+++ b/tools/fuzzing/interface/FuzzingInterface.cpp
@@ -0,0 +1,30 @@
+/* -*- 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/. */
+
+/*
+ * Common code for the unified fuzzing interface
+ */
+
+#include <stdarg.h>
+#include <stdlib.h>
+#include "FuzzingInterface.h"
+
+namespace mozilla {
+
+#ifdef JS_STANDALONE
+static bool fuzzing_verbose = !!getenv("MOZ_FUZZ_LOG");
+void fuzzing_log(const char* aFmt, ...) {
+  if (fuzzing_verbose) {
+    va_list ap;
+    va_start(ap, aFmt);
+    vfprintf(stderr, aFmt, ap);
+    va_end(ap);
+  }
+}
+#else
+LazyLogModule gFuzzingLog("nsFuzzing");
+#endif
+
+}  // namespace mozilla
diff --git a/tools/fuzzing/interface/FuzzingInterface.h b/tools/fuzzing/interface/FuzzingInterface.h
new file mode 100644
index 0000000000..792f0809ec
--- /dev/null
+++ b/tools/fuzzing/interface/FuzzingInterface.h
@@ -0,0 +1,115 @@
+/* -*- 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/. */
+
+/*
+ * Interface definitions for the unified fuzzing interface
+ */
+
+#ifndef FuzzingInterface_h__
+#define FuzzingInterface_h__
+
+#include <fstream>
+
+#ifdef LIBFUZZER
+#  include "FuzzerExtFunctions.h"
+#endif
+
+#include "FuzzerRegistry.h"
+#include "mozilla/Assertions.h"
+
+#ifndef JS_STANDALONE
+#  include "mozilla/Logging.h"
+#endif
+
+namespace mozilla {
+
+#ifdef JS_STANDALONE
+void fuzzing_log(const char* aFmt, ...);
+#  define MOZ_LOG_EXPAND_ARGS(...) __VA_ARGS__
+
+#  define FUZZING_LOG(args) fuzzing_log(MOZ_LOG_EXPAND_ARGS args);
+#else
+extern LazyLogModule gFuzzingLog;
+
+#  define FUZZING_LOG(args) \
+    MOZ_LOG(mozilla::gFuzzingLog, mozilla::LogLevel::Verbose, args)
+#endif  // JS_STANDALONE
+
+typedef int (*FuzzingTestFuncRaw)(const uint8_t*, size_t);
+
+#ifdef AFLFUZZ
+
+static int afl_interface_raw(const char* testFile,
+                             FuzzingTestFuncRaw testFunc) {
+  char* buf = NULL;
+
+  while (__AFL_LOOP(1000)) {
+    std::ifstream is;
+    is.open(testFile, std::ios::binary);
+    is.seekg(0, std::ios::end);
+    int len = is.tellg();
+    is.seekg(0, std::ios::beg);
+    MOZ_RELEASE_ASSERT(len >= 0);
+    if (!len) {
+      is.close();
+      continue;
+    }
+    buf = (char*)realloc(buf, len);
+    MOZ_RELEASE_ASSERT(buf);
+    is.read(buf, len);
+    is.close();
+    testFunc((uint8_t*)buf, (size_t)len);
+  }
+
+  free(buf);
+
+  return 0;
+}
+
+#  define MOZ_AFL_INTERFACE_COMMON()                                      \
+    char* testFilePtr = getenv("MOZ_FUZZ_TESTFILE");                      \
+    if (!testFilePtr) {                                                   \
+      fprintf(stderr,                                                     \
+              "Must specify testfile in MOZ_FUZZ_TESTFILE environment "   \
+              "variable.\n");                                             \
+      return 1;                                                           \
+    }                                                                     \
+    /* Make a copy of testFilePtr so the testing function can safely call \
+     * getenv                                                             \
+     */                                                                   \
+    std::string testFile(testFilePtr);
+
+#  define MOZ_AFL_INTERFACE_RAW(initFunc, testFunc, moduleName)          \
+    static int afl_fuzz_##moduleName(const uint8_t* data, size_t size) { \
+      MOZ_RELEASE_ASSERT(data == NULL && size == 0);                     \
+      MOZ_AFL_INTERFACE_COMMON();                                        \
+      return ::mozilla::afl_interface_raw(testFile.c_str(), testFunc);   \
+    }                                                                    \
+    static void __attribute__((constructor)) AFLRegister##moduleName() { \
+      ::mozilla::FuzzerRegistry::getInstance().registerModule(           \
+          #moduleName, initFunc, afl_fuzz_##moduleName);                 \
+    }
+#else
+#  define MOZ_AFL_INTERFACE_RAW(initFunc, testFunc, moduleName) /* Nothing */
+#endif                                                          // AFLFUZZ
+
+#ifdef LIBFUZZER
+#  define MOZ_LIBFUZZER_INTERFACE_RAW(initFunc, testFunc, moduleName)          \
+    static void __attribute__((constructor)) LibFuzzerRegister##moduleName() { \
+      ::mozilla::FuzzerRegistry::getInstance().registerModule(                 \
+          #moduleName, initFunc, testFunc);                                    \
+    }
+#else
+#  define MOZ_LIBFUZZER_INTERFACE_RAW(initFunc, testFunc, \
+                                      moduleName) /* Nothing */
+#endif
+
+#define MOZ_FUZZING_INTERFACE_RAW(initFunc, testFunc, moduleName) \
+  MOZ_LIBFUZZER_INTERFACE_RAW(initFunc, testFunc, moduleName);    \
+  MOZ_AFL_INTERFACE_RAW(initFunc, testFunc, moduleName);
+
+}  // namespace mozilla
+
+#endif  // FuzzingInterface_h__
diff --git a/tools/fuzzing/interface/FuzzingInterfaceStream.cpp b/tools/fuzzing/interface/FuzzingInterfaceStream.cpp
new file mode 100644
index 0000000000..f2c5c891e9
--- /dev/null
+++ b/tools/fuzzing/interface/FuzzingInterfaceStream.cpp
@@ -0,0 +1,54 @@
+/* -*- 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/. */
+
+/*
+ * Interface implementation for the unified fuzzing interface
+ */
+
+#include "nsIFile.h"
+#include "nsIPrefService.h"
+#include "nsIProperties.h"
+
+#include "FuzzingInterfaceStream.h"
+
+#include "mozilla/Assertions.h"
+
+#ifndef JS_STANDALONE
+#  include "nsNetUtil.h"
+#endif
+
+namespace mozilla {
+
+#ifdef AFLFUZZ
+
+void afl_interface_stream(const char* testFile,
+                          FuzzingTestFuncStream testFunc) {
+  nsresult rv;
+  nsCOMPtr<nsIProperties> dirService =
+      do_GetService(NS_DIRECTORY_SERVICE_CONTRACTID);
+  MOZ_RELEASE_ASSERT(dirService != nullptr);
+  nsCOMPtr<nsIFile> file;
+  rv = dirService->Get(NS_OS_CURRENT_WORKING_DIR, NS_GET_IID(nsIFile),
+                       getter_AddRefs(file));
+  MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+  file->AppendNative(nsDependentCString(testFile));
+  while (__AFL_LOOP(1000)) {
+    nsCOMPtr<nsIInputStream> inputStream;
+    rv = NS_NewLocalFileInputStream(getter_AddRefs(inputStream), file);
+    MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+    if (!NS_InputStreamIsBuffered(inputStream)) {
+      nsCOMPtr<nsIInputStream> bufStream;
+      rv = NS_NewBufferedInputStream(getter_AddRefs(bufStream),
+                                     inputStream.forget(), 1024);
+      MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));
+      inputStream = bufStream;
+    }
+    testFunc(inputStream.forget());
+  }
+}
+
+#endif
+
+}  // namespace mozilla
diff --git a/tools/fuzzing/interface/FuzzingInterfaceStream.h b/tools/fuzzing/interface/FuzzingInterfaceStream.h
new file mode 100644
index 0000000000..1542020794
--- /dev/null
+++ b/tools/fuzzing/interface/FuzzingInterfaceStream.h
@@ -0,0 +1,90 @@
+/* -*- 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/. */
+
+/*
+ * Interface definitions for the unified fuzzing interface with streaming
+ * support
+ */
+
+#ifndef FuzzingInterfaceStream_h__
+#define FuzzingInterfaceStream_h__
+
+#ifdef JS_STANDALONE
+#  error "FuzzingInterfaceStream.h cannot be used in JS standalone builds."
+#endif
+
+#include "gtest/gtest.h"
+#include "nsComponentManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsIInputStream.h"
+
+#include "nsDirectoryServiceDefs.h"
+#include "nsStreamUtils.h"
+#include "nsStringStream.h"
+
+#include <fstream>
+
+#include "FuzzingInterface.h"
+
+namespace mozilla {
+
+typedef int (*FuzzingTestFuncStream)(nsCOMPtr<nsIInputStream>);
+
+#ifdef AFLFUZZ
+void afl_interface_stream(const char* testFile, FuzzingTestFuncStream testFunc);
+
+#  define MOZ_AFL_INTERFACE_COMMON(initFunc)                              \
+    if (initFunc) initFunc(NULL, NULL);                                   \
+    char* testFilePtr = getenv("MOZ_FUZZ_TESTFILE");                      \
+    if (!testFilePtr) {                                                   \
+      fprintf(stderr,                                                     \
+              "Must specify testfile in MOZ_FUZZ_TESTFILE environment "   \
+              "variable.\n");                                             \
+      return;                                                             \
+    }                                                                     \
+    /* Make a copy of testFilePtr so the testing function can safely call \
+     * getenv                                                             \
+     */                                                                   \
+    std::string testFile(testFilePtr);
+
+#  define MOZ_AFL_INTERFACE_STREAM(initFunc, testFunc, moduleName) \
+    TEST(AFL, moduleName)                                          \
+    {                                                              \
+      MOZ_AFL_INTERFACE_COMMON(initFunc);                          \
+      ::mozilla::afl_interface_stream(testFile.c_str(), testFunc); \
+    }
+#else
+#  define MOZ_AFL_INTERFACE_STREAM(initFunc, testFunc, moduleName) /* Nothing \
+                                                                    */
+#endif
+
+#ifdef LIBFUZZER
+#  define MOZ_LIBFUZZER_INTERFACE_STREAM(initFunc, testFunc, moduleName)       \
+    static int LibFuzzerTest##moduleName(const uint8_t* data, size_t size) {   \
+      if (size > INT32_MAX) return 0;                                          \
+      nsCOMPtr<nsIInputStream> stream;                                         \
+      nsresult rv = NS_NewByteInputStream(getter_AddRefs(stream),              \
+                                          Span((const char*)data, size),       \
+                                          NS_ASSIGNMENT_DEPEND);               \
+      MOZ_RELEASE_ASSERT(NS_SUCCEEDED(rv));                                    \
+      testFunc(stream.forget());                                               \
+      return 0;                                                                \
+    }                                                                          \
+    static void __attribute__((constructor)) LibFuzzerRegister##moduleName() { \
+      ::mozilla::FuzzerRegistry::getInstance().registerModule(                 \
+          #moduleName, initFunc, LibFuzzerTest##moduleName);                   \
+    }
+#else
+#  define MOZ_LIBFUZZER_INTERFACE_STREAM(initFunc, testFunc, \
+                                         moduleName) /* Nothing */
+#endif
+
+#define MOZ_FUZZING_INTERFACE_STREAM(initFunc, testFunc, moduleName) \
+  MOZ_LIBFUZZER_INTERFACE_STREAM(initFunc, testFunc, moduleName);    \
+  MOZ_AFL_INTERFACE_STREAM(initFunc, testFunc, moduleName);
+
+}  // namespace mozilla
+
+#endif  // FuzzingInterfaceStream_h__
diff --git a/tools/fuzzing/interface/harness/FuzzerRunner.cpp b/tools/fuzzing/interface/harness/FuzzerRunner.cpp
new file mode 100644
index 0000000000..fc2094aa59
--- /dev/null
+++ b/tools/fuzzing/interface/harness/FuzzerRunner.cpp
@@ -0,0 +1,91 @@
+/* -*- 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 <cstdlib>
+
+#include "FuzzerRunner.h"
+#include "mozilla/Attributes.h"
+#include "prenv.h"
+
+#include "FuzzerTestHarness.h"
+
+namespace mozilla {
+
+// We use a static var 'fuzzerRunner' defined in nsAppRunner.cpp.
+// fuzzerRunner is initialized to nullptr but if this file is linked in,
+// then fuzzerRunner will be set here indicating that
+// we want to call into either LibFuzzer's main or the AFL entrypoint.
+class _InitFuzzer {
+ public:
+  _InitFuzzer() { fuzzerRunner = new FuzzerRunner(); }
+  void InitXPCOM() { mScopedXPCOM = new ScopedXPCOM("Fuzzer"); }
+  void DeinitXPCOM() {
+    if (mScopedXPCOM) delete mScopedXPCOM;
+    mScopedXPCOM = nullptr;
+  }
+
+ private:
+  ScopedXPCOM* mScopedXPCOM;
+} InitLibFuzzer;
+
+static void DeinitXPCOM() { InitLibFuzzer.DeinitXPCOM(); }
+
+int FuzzerRunner::Run(int* argc, char*** argv) {
+  /*
+   * libFuzzer uses exit() calls in several places instead of returning,
+   * so the destructor of ScopedXPCOM is not called in some cases.
+   * For fuzzing, this does not make a difference, but in debug builds
+   * when running a single testcase, this causes an assertion when destroying
+   * global linked lists. For this reason, we allocate ScopedXPCOM on the heap
+   * using the global InitLibFuzzer class, combined with an atexit call to
+   * destroy the ScopedXPCOM instance again.
+   */
+  InitLibFuzzer.InitXPCOM();
+  std::atexit(DeinitXPCOM);
+
+  const char* fuzzerEnv = getenv("FUZZER");
+
+  if (!fuzzerEnv) {
+    fprintf(stderr,
+            "Must specify fuzzing target in FUZZER environment variable\n");
+    exit(1);
+  }
+
+  std::string moduleNameStr(fuzzerEnv);
+  FuzzerFunctions funcs =
+      FuzzerRegistry::getInstance().getModuleFunctions(moduleNameStr);
+  FuzzerInitFunc initFunc = funcs.first;
+  FuzzerTestingFunc testingFunc = funcs.second;
+  if (initFunc) {
+    int ret = initFunc(argc, argv);
+    if (ret) {
+      fprintf(stderr, "Fuzzing Interface: Error: Initialize callback failed\n");
+      exit(1);
+    }
+  }
+
+  if (!testingFunc) {
+    fprintf(stderr, "Fuzzing Interface: Error: No testing callback found\n");
+    exit(1);
+  }
+
+#ifdef LIBFUZZER
+  int ret = mFuzzerDriver(argc, argv, testingFunc);
+#else
+  // For AFL, testingFunc points to the entry function we need.
+  int ret = testingFunc(NULL, 0);
+#endif
+
+  InitLibFuzzer.DeinitXPCOM();
+  return ret;
+}
+
+#ifdef LIBFUZZER
+void FuzzerRunner::setParams(LibFuzzerDriver aDriver) {
+  mFuzzerDriver = aDriver;
+}
+#endif
+
+}  // namespace mozilla
diff --git a/tools/fuzzing/interface/harness/FuzzerRunner.h b/tools/fuzzing/interface/harness/FuzzerRunner.h
new file mode 100644
index 0000000000..6b19e751cd
--- /dev/null
+++ b/tools/fuzzing/interface/harness/FuzzerRunner.h
@@ -0,0 +1,24 @@
+/* -*- 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 "FuzzerRegistry.h"
+
+namespace mozilla {
+
+class FuzzerRunner {
+ public:
+  int Run(int* argc, char*** argv);
+
+#ifdef LIBFUZZER
+  void setParams(LibFuzzerDriver aDriver);
+
+ private:
+  LibFuzzerDriver mFuzzerDriver;
+#endif
+};
+
+extern FuzzerRunner* fuzzerRunner;
+
+}  // namespace mozilla
diff --git a/tools/fuzzing/interface/harness/FuzzerTestHarness.h b/tools/fuzzing/interface/harness/FuzzerTestHarness.h
new file mode 100644
index 0000000000..d7bb1064cf
--- /dev/null
+++ b/tools/fuzzing/interface/harness/FuzzerTestHarness.h
@@ -0,0 +1,256 @@
+/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+/*
+ * Test harness for XPCOM objects, providing a scoped XPCOM initializer,
+ * nsCOMPtr, nsRefPtr, do_CreateInstance, do_GetService, ns(Auto|C|)String,
+ * and stdio.h/stdlib.h.
+ */
+
+#ifndef FuzzerTestHarness_h__
+#define FuzzerTestHarness_h__
+
+#include "mozilla/ArrayUtils.h"
+#include "mozilla/Attributes.h"
+
+#include "prenv.h"
+#include "nsComponentManagerUtils.h"
+#include "nsServiceManagerUtils.h"
+#include "nsCOMPtr.h"
+#include "nsString.h"
+#include "nsAppDirectoryServiceDefs.h"
+#include "nsDirectoryServiceDefs.h"
+#include "nsDirectoryServiceUtils.h"
+#include "nsIDirectoryService.h"
+#include "nsIFile.h"
+#include "nsIObserverService.h"
+#include "nsIServiceManager.h"
+#include "nsXULAppAPI.h"
+#include "mozilla/AppShutdown.h"
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdarg.h>
+
+namespace {
+
+static uint32_t gFailCount = 0;
+
+/**
+ * Prints the given failure message and arguments using printf, prepending
+ * "TEST-UNEXPECTED-FAIL " for the benefit of the test harness and
+ * appending "\n" to eliminate having to type it at each call site.
+ */
+MOZ_FORMAT_PRINTF(1, 2) void fail(const char* msg, ...) {
+  va_list ap;
+
+  printf("TEST-UNEXPECTED-FAIL | ");
+
+  va_start(ap, msg);
+  vprintf(msg, ap);
+  va_end(ap);
+
+  putchar('\n');
+  ++gFailCount;
+}
+
+//-----------------------------------------------------------------------------
+
+class ScopedXPCOM final : public nsIDirectoryServiceProvider2 {
+ public:
+  NS_DECL_ISUPPORTS
+
+  explicit ScopedXPCOM(const char* testName,
+                       nsIDirectoryServiceProvider* dirSvcProvider = nullptr)
+      : mDirSvcProvider(dirSvcProvider) {
+    mTestName = testName;
+    printf("Running %s tests...\n", mTestName);
+
+    nsresult rv = NS_InitXPCOM(&mServMgr, nullptr, this);
+    if (NS_FAILED(rv)) {
+      fail("NS_InitXPCOM returned failure code 0x%" PRIx32,
+           static_cast<uint32_t>(rv));
+      mServMgr = nullptr;
+      return;
+    }
+  }
+
+  ~ScopedXPCOM() {
+    // If we created a profile directory, we need to remove it.
+    if (mProfD) {
+      mozilla::AppShutdown::AdvanceShutdownPhase(
+          mozilla::ShutdownPhase::AppShutdownNetTeardown);
+      mozilla::AppShutdown::AdvanceShutdownPhase(
+          mozilla::ShutdownPhase::AppShutdownTeardown);
+      mozilla::AppShutdown::AdvanceShutdownPhase(
+          mozilla::ShutdownPhase::AppShutdown);
+      mozilla::AppShutdown::AdvanceShutdownPhase(
+          mozilla::ShutdownPhase::AppShutdownQM);
+      mozilla::AppShutdown::AdvanceShutdownPhase(
+          mozilla::ShutdownPhase::AppShutdownTelemetry);
+
+      if (NS_FAILED(mProfD->Remove(true))) {
+        NS_WARNING("Problem removing profile directory");
+      }
+
+      mProfD = nullptr;
+    }
+
+    if (mServMgr) {
+      NS_RELEASE(mServMgr);
+      nsresult rv = NS_ShutdownXPCOM(nullptr);
+      if (NS_FAILED(rv)) {
+        fail("XPCOM shutdown failed with code 0x%" PRIx32,
+             static_cast<uint32_t>(rv));
+        exit(1);
+      }
+    }
+
+    printf("Finished running %s tests.\n", mTestName);
+  }
+
+  already_AddRefed<nsIFile> GetProfileDirectory() {
+    if (mProfD) {
+      nsCOMPtr<nsIFile> copy = mProfD;
+      return copy.forget();
+    }
+
+    // Create a unique temporary folder to use for this test.
+    // Note that runcppunittests.py will run tests with a temp
+    // directory as the cwd, so just put something under that.
+    nsCOMPtr<nsIFile> profD;
+    nsresult rv = NS_GetSpecialDirectory(NS_OS_CURRENT_PROCESS_DIR,
+                                         getter_AddRefs(profD));
+    NS_ENSURE_SUCCESS(rv, nullptr);
+
+    rv = profD->Append(u"cpp-unit-profd"_ns);
+    NS_ENSURE_SUCCESS(rv, nullptr);
+
+    rv = profD->CreateUnique(nsIFile::DIRECTORY_TYPE, 0755);
+    NS_ENSURE_SUCCESS(rv, nullptr);
+
+    mProfD = profD;
+    return profD.forget();
+  }
+
+  already_AddRefed<nsIFile> GetGREDirectory() {
+    if (mGRED) {
+      nsCOMPtr<nsIFile> copy = mGRED;
+      return copy.forget();
+    }
+
+    char* env = PR_GetEnv("MOZ_XRE_DIR");
+    nsCOMPtr<nsIFile> greD;
+    if (env) {
+      NS_NewLocalFile(NS_ConvertUTF8toUTF16(env), false, getter_AddRefs(greD));
+    }
+
+    mGRED = greD;
+    return greD.forget();
+  }
+
+  already_AddRefed<nsIFile> GetGREBinDirectory() {
+    if (mGREBinD) {
+      nsCOMPtr<nsIFile> copy = mGREBinD;
+      return copy.forget();
+    }
+
+    nsCOMPtr<nsIFile> greD = GetGREDirectory();
+    if (!greD) {
+      return greD.forget();
+    }
+    greD->Clone(getter_AddRefs(mGREBinD));
+
+#ifdef XP_MACOSX
+    nsAutoCString leafName;
+    mGREBinD->GetNativeLeafName(leafName);
+    if (leafName.EqualsLiteral("Resources")) {
+      mGREBinD->SetNativeLeafName("MacOS"_ns);
+    }
+#endif
+
+    nsCOMPtr<nsIFile> copy = mGREBinD;
+    return copy.forget();
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  //// nsIDirectoryServiceProvider
+
+  NS_IMETHODIMP GetFile(const char* aProperty, bool* _persistent,
+                        nsIFile** _result) override {
+    // If we were supplied a directory service provider, ask it first.
+    if (mDirSvcProvider && NS_SUCCEEDED(mDirSvcProvider->GetFile(
+                               aProperty, _persistent, _result))) {
+      return NS_OK;
+    }
+
+    // Otherwise, the test harness provides some directories automatically.
+    if (0 == strcmp(aProperty, NS_APP_USER_PROFILE_50_DIR) ||
+        0 == strcmp(aProperty, NS_APP_USER_PROFILE_LOCAL_50_DIR) ||
+        0 == strcmp(aProperty, NS_APP_PROFILE_LOCAL_DIR_STARTUP)) {
+      nsCOMPtr<nsIFile> profD = GetProfileDirectory();
+      NS_ENSURE_TRUE(profD, NS_ERROR_FAILURE);
+
+      nsCOMPtr<nsIFile> clone;
+      nsresult rv = profD->Clone(getter_AddRefs(clone));
+      NS_ENSURE_SUCCESS(rv, rv);
+
+      *_persistent = true;
+      clone.forget(_result);
+      return NS_OK;
+    } else if (0 == strcmp(aProperty, NS_GRE_DIR)) {
+      nsCOMPtr<nsIFile> greD = GetGREDirectory();
+      NS_ENSURE_TRUE(greD, NS_ERROR_FAILURE);
+
+      *_persistent = true;
+      greD.forget(_result);
+      return NS_OK;
+    } else if (0 == strcmp(aProperty, NS_GRE_BIN_DIR)) {
+      nsCOMPtr<nsIFile> greBinD = GetGREBinDirectory();
+      NS_ENSURE_TRUE(greBinD, NS_ERROR_FAILURE);
+
+      *_persistent = true;
+      greBinD.forget(_result);
+      return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+  }
+
+  ////////////////////////////////////////////////////////////////////////////
+  //// nsIDirectoryServiceProvider2
+
+  NS_IMETHODIMP GetFiles(const char* aProperty,
+                         nsISimpleEnumerator** _enum) override {
+    // If we were supplied a directory service provider, ask it first.
+    nsCOMPtr<nsIDirectoryServiceProvider2> provider =
+        do_QueryInterface(mDirSvcProvider);
+    if (provider && NS_SUCCEEDED(provider->GetFiles(aProperty, _enum))) {
+      return NS_OK;
+    }
+
+    return NS_ERROR_FAILURE;
+  }
+
+ private:
+  const char* mTestName;
+  nsIServiceManager* mServMgr;
+  nsCOMPtr<nsIDirectoryServiceProvider> mDirSvcProvider;
+  nsCOMPtr<nsIFile> mProfD;
+  nsCOMPtr<nsIFile> mGRED;
+  nsCOMPtr<nsIFile> mGREBinD;
+};
+
+NS_IMPL_QUERY_INTERFACE(ScopedXPCOM, nsIDirectoryServiceProvider,
+                        nsIDirectoryServiceProvider2)
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+ScopedXPCOM::AddRef() { return 2; }
+
+NS_IMETHODIMP_(MozExternalRefCountType)
+ScopedXPCOM::Release() { return 1; }
+
+}  // namespace
+
+#endif  // FuzzerTestHarness_h__
diff --git a/tools/fuzzing/interface/harness/moz.build b/tools/fuzzing/interface/harness/moz.build
new file mode 100644
index 0000000000..0eff84c8aa
--- /dev/null
+++ b/tools/fuzzing/interface/harness/moz.build
@@ -0,0 +1,16 @@
+# -*- Mode: python; c-basic-offset: 4; 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/.
+
+Library("fuzzer-runner")
+
+SOURCES += [
+    "FuzzerRunner.cpp",
+]
+EXPORTS += [
+    "FuzzerRunner.h",
+]
+
+FINAL_LIBRARY = "xul"
diff --git a/tools/fuzzing/interface/moz.build b/tools/fuzzing/interface/moz.build
new file mode 100644
index 0000000000..8a51007174
--- /dev/null
+++ b/tools/fuzzing/interface/moz.build
@@ -0,0 +1,32 @@
+# -*- Mode: python; c-basic-offset: 4; 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/.
+
+Library("fuzzer-interface")
+
+EXPORTS += [
+    "FuzzingInterface.h",
+]
+
+SOURCES += [
+    "FuzzingInterface.cpp",
+]
+
+if CONFIG["JS_STANDALONE"]:
+    FINAL_LIBRARY = "js"
+else:
+    EXPORTS += [
+        "FuzzingInterfaceStream.h",
+    ]
+
+    SOURCES += [
+        "FuzzingInterfaceStream.cpp",
+    ]
+
+    DIRS += [
+        "harness",
+    ]
+
+    FINAL_LIBRARY = "xul-gtest"