duckstation

gtest.cc (234095B)

---

 // Copyright 2005, 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.
 
 //
 // The Google C++ Testing and Mocking Framework (Google Test)
 
 #include "gtest/gtest.h"
 #include "gtest/internal/custom/gtest.h"
 #include "gtest/gtest-spi.h"
 
 #include <ctype.h>
 #include <math.h>
 #include <stdarg.h>
 #include <stdio.h>
 #include <stdlib.h>
 #include <time.h>
 #include <wchar.h>
 #include <wctype.h>
 
 #include <algorithm>
 #include <cstdint>
 #include <iomanip>
 #include <limits>
 #include <list>
 #include <map>
 #include <ostream>  // NOLINT
 #include <sstream>
 #include <vector>
 
 #if GTEST_OS_LINUX
 
 # define GTEST_HAS_GETTIMEOFDAY_ 1
 
 # include <fcntl.h>  // NOLINT
 # include <limits.h>  // NOLINT
 # include <sched.h>  // NOLINT
 // Declares vsnprintf().  This header is not available on Windows.
 # include <strings.h>  // NOLINT
 # include <sys/mman.h>  // NOLINT
 # include <sys/time.h>  // NOLINT
 # include <unistd.h>  // NOLINT
 # include <string>
 
 #elif GTEST_OS_ZOS
 # define GTEST_HAS_GETTIMEOFDAY_ 1
 # include <sys/time.h>  // NOLINT
 
 // On z/OS we additionally need strings.h for strcasecmp.
 # include <strings.h>  // NOLINT
 
 #elif GTEST_OS_WINDOWS_MOBILE  // We are on Windows CE.
 
 # include <windows.h>  // NOLINT
 # undef min
 
 #elif GTEST_OS_WINDOWS  // We are on Windows proper.
 
 # include <windows.h>  // NOLINT
 # undef min
 
 #ifdef _MSC_VER
 # include <crtdbg.h>  // NOLINT
 # include <debugapi.h>  // NOLINT
 #endif
 
 # include <io.h>  // NOLINT
 # include <sys/timeb.h>  // NOLINT
 # include <sys/types.h>  // NOLINT
 # include <sys/stat.h>  // NOLINT
 
 # if GTEST_OS_WINDOWS_MINGW
 // MinGW has gettimeofday() but not _ftime64().
 #  define GTEST_HAS_GETTIMEOFDAY_ 1
 #  include <sys/time.h>  // NOLINT
 # endif  // GTEST_OS_WINDOWS_MINGW
 
 #else
 
 // Assume other platforms have gettimeofday().
 # define GTEST_HAS_GETTIMEOFDAY_ 1
 
 // cpplint thinks that the header is already included, so we want to
 // silence it.
 # include <sys/time.h>  // NOLINT
 # include <unistd.h>  // NOLINT
 
 #endif  // GTEST_OS_LINUX
 
 #if GTEST_HAS_EXCEPTIONS
 # include <stdexcept>
 #endif
 
 #if GTEST_CAN_STREAM_RESULTS_
 # include <arpa/inet.h>  // NOLINT
 # include <netdb.h>  // NOLINT
 # include <sys/socket.h>  // NOLINT
 # include <sys/types.h>  // NOLINT
 #endif
 
 #include "src/gtest-internal-inl.h"
 
 #if GTEST_OS_WINDOWS
 # define vsnprintf _vsnprintf
 #endif  // GTEST_OS_WINDOWS
 
 #if GTEST_OS_MAC
 #ifndef GTEST_OS_IOS
 #include <crt_externs.h>
 #endif
 #endif
 
 #if GTEST_HAS_ABSL
 #include "absl/debugging/failure_signal_handler.h"
 #include "absl/debugging/stacktrace.h"
 #include "absl/debugging/symbolize.h"
 #include "absl/strings/str_cat.h"
 #endif  // GTEST_HAS_ABSL
 
 namespace testing {
 
 using internal::CountIf;
 using internal::ForEach;
 using internal::GetElementOr;
 using internal::Shuffle;
 
 // Constants.
 
 // A test whose test suite name or test name matches this filter is
 // disabled and not run.
 static const char kDisableTestFilter[] = "DISABLED_*:*/DISABLED_*";
 
 // A test suite whose name matches this filter is considered a death
 // test suite and will be run before test suites whose name doesn't
 // match this filter.
 static const char kDeathTestSuiteFilter[] = "*DeathTest:*DeathTest/*";
 
 // A test filter that matches everything.
 static const char kUniversalFilter[] = "*";
 
 // The default output format.
 static const char kDefaultOutputFormat[] = "xml";
 // The default output file.
 static const char kDefaultOutputFile[] = "test_detail";
 
 // The environment variable name for the test shard index.
 static const char kTestShardIndex[] = "GTEST_SHARD_INDEX";
 // The environment variable name for the total number of test shards.
 static const char kTestTotalShards[] = "GTEST_TOTAL_SHARDS";
 // The environment variable name for the test shard status file.
 static const char kTestShardStatusFile[] = "GTEST_SHARD_STATUS_FILE";
 
 namespace internal {
 
 // The text used in failure messages to indicate the start of the
 // stack trace.
 const char kStackTraceMarker[] = "\nStack trace:\n";
 
 // g_help_flag is true if and only if the --help flag or an equivalent form
 // is specified on the command line.
 bool g_help_flag = false;
 
 // Utilty function to Open File for Writing
 static FILE* OpenFileForWriting(const std::string& output_file) {
   FILE* fileout = nullptr;
   FilePath output_file_path(output_file);
   FilePath output_dir(output_file_path.RemoveFileName());
 
   if (output_dir.CreateDirectoriesRecursively()) {
     fileout = posix::FOpen(output_file.c_str(), "w");
   }
   if (fileout == nullptr) {
     GTEST_LOG_(FATAL) << "Unable to open file \"" << output_file << "\"";
   }
   return fileout;
 }
 
 }  // namespace internal
 
 // Bazel passes in the argument to '--test_filter' via the TESTBRIDGE_TEST_ONLY
 // environment variable.
 static const char* GetDefaultFilter() {
   const char* const testbridge_test_only =
       internal::posix::GetEnv("TESTBRIDGE_TEST_ONLY");
   if (testbridge_test_only != nullptr) {
     return testbridge_test_only;
   }
   return kUniversalFilter;
 }
 
 GTEST_DEFINE_bool_(
     also_run_disabled_tests,
     internal::BoolFromGTestEnv("also_run_disabled_tests", false),
     "Run disabled tests too, in addition to the tests normally being run.");
 
 GTEST_DEFINE_bool_(
     break_on_failure, internal::BoolFromGTestEnv("break_on_failure", false),
     "True if and only if a failed assertion should be a debugger "
     "break-point.");
 
 GTEST_DEFINE_bool_(catch_exceptions,
                    internal::BoolFromGTestEnv("catch_exceptions", true),
                    "True if and only if " GTEST_NAME_
                    " should catch exceptions and treat them as test failures.");
 
 GTEST_DEFINE_string_(
     color,
     internal::StringFromGTestEnv("color", "auto"),
     "Whether to use colors in the output.  Valid values: yes, no, "
     "and auto.  'auto' means to use colors if the output is "
     "being sent to a terminal and the TERM environment variable "
     "is set to a terminal type that supports colors.");
 
 GTEST_DEFINE_string_(
     filter,
     internal::StringFromGTestEnv("filter", GetDefaultFilter()),
     "A colon-separated list of glob (not regex) patterns "
     "for filtering the tests to run, optionally followed by a "
     "'-' and a : separated list of negative patterns (tests to "
     "exclude).  A test is run if it matches one of the positive "
     "patterns and does not match any of the negative patterns.");
 
 GTEST_DEFINE_bool_(
     install_failure_signal_handler,
     internal::BoolFromGTestEnv("install_failure_signal_handler", false),
     "If true and supported on the current platform, " GTEST_NAME_ " should "
     "install a signal handler that dumps debugging information when fatal "
     "signals are raised.");
 
 GTEST_DEFINE_bool_(list_tests, false,
                    "List all tests without running them.");
 
 // The net priority order after flag processing is thus:
 //   --gtest_output command line flag
 //   GTEST_OUTPUT environment variable
 //   XML_OUTPUT_FILE environment variable
 //   ''
 GTEST_DEFINE_string_(
     output,
     internal::StringFromGTestEnv("output",
       internal::OutputFlagAlsoCheckEnvVar().c_str()),
     "A format (defaults to \"xml\" but can be specified to be \"json\"), "
     "optionally followed by a colon and an output file name or directory. "
     "A directory is indicated by a trailing pathname separator. "
     "Examples: \"xml:filename.xml\", \"xml::directoryname/\". "
     "If a directory is specified, output files will be created "
     "within that directory, with file-names based on the test "
     "executable's name and, if necessary, made unique by adding "
     "digits.");
 
 GTEST_DEFINE_bool_(print_time, internal::BoolFromGTestEnv("print_time", true),
                    "True if and only if " GTEST_NAME_
                    " should display elapsed time in text output.");
 
 GTEST_DEFINE_bool_(print_utf8, internal::BoolFromGTestEnv("print_utf8", true),
                    "True if and only if " GTEST_NAME_
                    " prints UTF8 characters as text.");
 
 GTEST_DEFINE_int32_(
     random_seed,
     internal::Int32FromGTestEnv("random_seed", 0),
     "Random number seed to use when shuffling test orders.  Must be in range "
     "[1, 99999], or 0 to use a seed based on the current time.");
 
 GTEST_DEFINE_int32_(
     repeat,
     internal::Int32FromGTestEnv("repeat", 1),
     "How many times to repeat each test.  Specify a negative number "
     "for repeating forever.  Useful for shaking out flaky tests.");
 
 GTEST_DEFINE_bool_(show_internal_stack_frames, false,
                    "True if and only if " GTEST_NAME_
                    " should include internal stack frames when "
                    "printing test failure stack traces.");
 
 GTEST_DEFINE_bool_(shuffle, internal::BoolFromGTestEnv("shuffle", false),
                    "True if and only if " GTEST_NAME_
                    " should randomize tests' order on every run.");
 
 GTEST_DEFINE_int32_(
     stack_trace_depth,
     internal::Int32FromGTestEnv("stack_trace_depth", kMaxStackTraceDepth),
     "The maximum number of stack frames to print when an "
     "assertion fails.  The valid range is 0 through 100, inclusive.");
 
 GTEST_DEFINE_string_(
     stream_result_to,
     internal::StringFromGTestEnv("stream_result_to", ""),
     "This flag specifies the host name and the port number on which to stream "
     "test results. Example: \"localhost:555\". The flag is effective only on "
     "Linux.");
 
 GTEST_DEFINE_bool_(
     throw_on_failure,
     internal::BoolFromGTestEnv("throw_on_failure", false),
     "When this flag is specified, a failed assertion will throw an exception "
     "if exceptions are enabled or exit the program with a non-zero code "
     "otherwise. For use with an external test framework.");
 
 #if GTEST_USE_OWN_FLAGFILE_FLAG_
 GTEST_DEFINE_string_(
     flagfile,
     internal::StringFromGTestEnv("flagfile", ""),
     "This flag specifies the flagfile to read command-line flags from.");
 #endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
 
 namespace internal {
 
 // Generates a random number from [0, range), using a Linear
 // Congruential Generator (LCG).  Crashes if 'range' is 0 or greater
 // than kMaxRange.
 uint32_t Random::Generate(uint32_t range) {
   // These constants are the same as are used in glibc's rand(3).
   // Use wider types than necessary to prevent unsigned overflow diagnostics.
   state_ = static_cast<uint32_t>(1103515245ULL*state_ + 12345U) % kMaxRange;
 
   GTEST_CHECK_(range > 0)
       << "Cannot generate a number in the range [0, 0).";
   GTEST_CHECK_(range <= kMaxRange)
       << "Generation of a number in [0, " << range << ") was requested, "
       << "but this can only generate numbers in [0, " << kMaxRange << ").";
 
   // Converting via modulus introduces a bit of downward bias, but
   // it's simple, and a linear congruential generator isn't too good
   // to begin with.
   return state_ % range;
 }
 
 // GTestIsInitialized() returns true if and only if the user has initialized
 // Google Test.  Useful for catching the user mistake of not initializing
 // Google Test before calling RUN_ALL_TESTS().
 static bool GTestIsInitialized() { return GetArgvs().size() > 0; }
 
 // Iterates over a vector of TestSuites, keeping a running sum of the
 // results of calling a given int-returning method on each.
 // Returns the sum.
 static int SumOverTestSuiteList(const std::vector<TestSuite*>& case_list,
                                 int (TestSuite::*method)() const) {
   int sum = 0;
   for (size_t i = 0; i < case_list.size(); i++) {
     sum += (case_list[i]->*method)();
   }
   return sum;
 }
 
 // Returns true if and only if the test suite passed.
 static bool TestSuitePassed(const TestSuite* test_suite) {
   return test_suite->should_run() && test_suite->Passed();
 }
 
 // Returns true if and only if the test suite failed.
 static bool TestSuiteFailed(const TestSuite* test_suite) {
   return test_suite->should_run() && test_suite->Failed();
 }
 
 // Returns true if and only if test_suite contains at least one test that
 // should run.
 static bool ShouldRunTestSuite(const TestSuite* test_suite) {
   return test_suite->should_run();
 }
 
 // AssertHelper constructor.
 AssertHelper::AssertHelper(TestPartResult::Type type,
                            const char* file,
                            int line,
                            const char* message)
     : data_(new AssertHelperData(type, file, line, message)) {
 }
 
 AssertHelper::~AssertHelper() {
   delete data_;
 }
 
 // Message assignment, for assertion streaming support.
 void AssertHelper::operator=(const Message& message) const {
   UnitTest::GetInstance()->
     AddTestPartResult(data_->type, data_->file, data_->line,
                       AppendUserMessage(data_->message, message),
                       UnitTest::GetInstance()->impl()
                       ->CurrentOsStackTraceExceptTop(1)
                       // Skips the stack frame for this function itself.
                       );  // NOLINT
 }
 
 namespace {
 
 // When TEST_P is found without a matching INSTANTIATE_TEST_SUITE_P
 // to creates test cases for it, a syntetic test case is
 // inserted to report ether an error or a log message.
 //
 // This configuration bit will likely be removed at some point.
 constexpr bool kErrorOnUninstantiatedParameterizedTest = false;
 constexpr bool kErrorOnUninstantiatedTypeParameterizedTest = false;
 
 // A test that fails at a given file/line location with a given message.
 class FailureTest : public Test {
  public:
   explicit FailureTest(const CodeLocation& loc, std::string error_message,
                        bool as_error)
       : loc_(loc),
         error_message_(std::move(error_message)),
         as_error_(as_error) {}
 
   void TestBody() override {
     if (as_error_) {
       AssertHelper(TestPartResult::kNonFatalFailure, loc_.file.c_str(),
                    loc_.line, "") = Message() << error_message_;
     } else {
       std::cout << error_message_ << std::endl;
     }
   }
 
  private:
   const CodeLocation loc_;
   const std::string error_message_;
   const bool as_error_;
 };
 
 
 }  // namespace
 
 std::set<std::string>* GetIgnoredParameterizedTestSuites() {
   return UnitTest::GetInstance()->impl()->ignored_parameterized_test_suites();
 }
 
 // Add a given test_suit to the list of them allow to go un-instantiated.
 MarkAsIgnored::MarkAsIgnored(const char* test_suite) {
   GetIgnoredParameterizedTestSuites()->insert(test_suite);
 }
 
 // If this parameterized test suite has no instantiations (and that
 // has not been marked as okay), emit a test case reporting that.
 void InsertSyntheticTestCase(const std::string& name, CodeLocation location,
                              bool has_test_p) {
   const auto& ignored = *GetIgnoredParameterizedTestSuites();
   if (ignored.find(name) != ignored.end()) return;
 
   const char kMissingInstantiation[] =  //
       " is defined via TEST_P, but never instantiated. None of the test cases "
       "will run. Either no INSTANTIATE_TEST_SUITE_P is provided or the only "
       "ones provided expand to nothing."
       "\n\n"
       "Ideally, TEST_P definitions should only ever be included as part of "
       "binaries that intend to use them. (As opposed to, for example, being "
       "placed in a library that may be linked in to get other utilities.)";
 
   const char kMissingTestCase[] =  //
       " is instantiated via INSTANTIATE_TEST_SUITE_P, but no tests are "
       "defined via TEST_P . No test cases will run."
       "\n\n"
       "Ideally, INSTANTIATE_TEST_SUITE_P should only ever be invoked from "
       "code that always depend on code that provides TEST_P. Failing to do "
       "so is often an indication of dead code, e.g. the last TEST_P was "
       "removed but the rest got left behind.";
 
   std::string message =
       "Paramaterized test suite " + name +
       (has_test_p ? kMissingInstantiation : kMissingTestCase) +
       "\n\n"
       "To suppress this error for this test suite, insert the following line "
       "(in a non-header) in the namespace it is defined in:"
       "\n\n"
       "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" + name + ");";
 
   std::string full_name = "UninstantiatedParamaterizedTestSuite<" + name + ">";
   RegisterTest(  //
       "GoogleTestVerification", full_name.c_str(),
       nullptr,  // No type parameter.
       nullptr,  // No value parameter.
       location.file.c_str(), location.line, [message, location] {
         return new FailureTest(location, message,
                                kErrorOnUninstantiatedParameterizedTest);
       });
 }
 
 void RegisterTypeParameterizedTestSuite(const char* test_suite_name,
                                         CodeLocation code_location) {
   GetUnitTestImpl()->type_parameterized_test_registry().RegisterTestSuite(
       test_suite_name, code_location);
 }
 
 void RegisterTypeParameterizedTestSuiteInstantiation(const char* case_name) {
   GetUnitTestImpl()
       ->type_parameterized_test_registry()
       .RegisterInstantiation(case_name);
 }
 
 void TypeParameterizedTestSuiteRegistry::RegisterTestSuite(
     const char* test_suite_name, CodeLocation code_location) {
   suites_.emplace(std::string(test_suite_name),
                  TypeParameterizedTestSuiteInfo(code_location));
 }
 
 void TypeParameterizedTestSuiteRegistry::RegisterInstantiation(
         const char* test_suite_name) {
   auto it = suites_.find(std::string(test_suite_name));
   if (it != suites_.end()) {
     it->second.instantiated = true;
   } else {
     GTEST_LOG_(ERROR) << "Unknown type parameterized test suit '"
                       << test_suite_name << "'";
   }
 }
 
 void TypeParameterizedTestSuiteRegistry::CheckForInstantiations() {
   const auto& ignored = *GetIgnoredParameterizedTestSuites();
   for (const auto& testcase : suites_) {
     if (testcase.second.instantiated) continue;
     if (ignored.find(testcase.first) != ignored.end()) continue;
 
     std::string message =
         "Type paramaterized test suite " + testcase.first +
         " is defined via REGISTER_TYPED_TEST_SUITE_P, but never instantiated "
         "via INSTANTIATE_TYPED_TEST_SUITE_P. None of the test cases will run."
         "\n\n"
         "Ideally, TYPED_TEST_P definitions should only ever be included as "
         "part of binaries that intend to use them. (As opposed to, for "
         "example, being placed in a library that may be linked in to get other "
         "utilities.)"
         "\n\n"
         "To suppress this error for this test suite, insert the following line "
         "(in a non-header) in the namespace it is definedin in:"
         "\n\n"
         "GTEST_ALLOW_UNINSTANTIATED_PARAMETERIZED_TEST(" +
         testcase.first + ");";
 
     std::string full_name =
         "UninstantiatedTypeParamaterizedTestSuite<" + testcase.first + ">";
     RegisterTest(  //
         "GoogleTestVerification", full_name.c_str(),
         nullptr,  // No type parameter.
         nullptr,  // No value parameter.
         testcase.second.code_location.file.c_str(),
         testcase.second.code_location.line, [message, testcase] {
           return new FailureTest(testcase.second.code_location, message,
                                  kErrorOnUninstantiatedTypeParameterizedTest);
         });
   }
 }
 
 // A copy of all command line arguments.  Set by InitGoogleTest().
 static ::std::vector<std::string> g_argvs;
 
 ::std::vector<std::string> GetArgvs() {
 #if defined(GTEST_CUSTOM_GET_ARGVS_)
   // GTEST_CUSTOM_GET_ARGVS_() may return a container of std::string or
   // ::string. This code converts it to the appropriate type.
   const auto& custom = GTEST_CUSTOM_GET_ARGVS_();
   return ::std::vector<std::string>(custom.begin(), custom.end());
 #else   // defined(GTEST_CUSTOM_GET_ARGVS_)
   return g_argvs;
 #endif  // defined(GTEST_CUSTOM_GET_ARGVS_)
 }
 
 // Returns the current application's name, removing directory path if that
 // is present.
 FilePath GetCurrentExecutableName() {
   FilePath result;
 
 #if GTEST_OS_WINDOWS || GTEST_OS_OS2
   result.Set(FilePath(GetArgvs()[0]).RemoveExtension("exe"));
 #else
   result.Set(FilePath(GetArgvs()[0]));
 #endif  // GTEST_OS_WINDOWS
 
   return result.RemoveDirectoryName();
 }
 
 // Functions for processing the gtest_output flag.
 
 // Returns the output format, or "" for normal printed output.
 std::string UnitTestOptions::GetOutputFormat() {
   const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
   const char* const colon = strchr(gtest_output_flag, ':');
   return (colon == nullptr)
              ? std::string(gtest_output_flag)
              : std::string(gtest_output_flag,
                            static_cast<size_t>(colon - gtest_output_flag));
 }
 
 // Returns the name of the requested output file, or the default if none
 // was explicitly specified.
 std::string UnitTestOptions::GetAbsolutePathToOutputFile() {
   const char* const gtest_output_flag = GTEST_FLAG(output).c_str();
 
   std::string format = GetOutputFormat();
   if (format.empty())
     format = std::string(kDefaultOutputFormat);
 
   const char* const colon = strchr(gtest_output_flag, ':');
   if (colon == nullptr)
     return internal::FilePath::MakeFileName(
         internal::FilePath(
             UnitTest::GetInstance()->original_working_dir()),
         internal::FilePath(kDefaultOutputFile), 0,
         format.c_str()).string();
 
   internal::FilePath output_name(colon + 1);
   if (!output_name.IsAbsolutePath())
     output_name = internal::FilePath::ConcatPaths(
         internal::FilePath(UnitTest::GetInstance()->original_working_dir()),
         internal::FilePath(colon + 1));
 
   if (!output_name.IsDirectory())
     return output_name.string();
 
   internal::FilePath result(internal::FilePath::GenerateUniqueFileName(
       output_name, internal::GetCurrentExecutableName(),
       GetOutputFormat().c_str()));
   return result.string();
 }
 
 // Returns true if and only if the wildcard pattern matches the string.
 // The first ':' or '\0' character in pattern marks the end of it.
 //
 // This recursive algorithm isn't very efficient, but is clear and
 // works well enough for matching test names, which are short.
 bool UnitTestOptions::PatternMatchesString(const char *pattern,
                                            const char *str) {
   switch (*pattern) {
     case '\0':
     case ':':  // Either ':' or '\0' marks the end of the pattern.
       return *str == '\0';
     case '?':  // Matches any single character.
       return *str != '\0' && PatternMatchesString(pattern + 1, str + 1);
     case '*':  // Matches any string (possibly empty) of characters.
       return (*str != '\0' && PatternMatchesString(pattern, str + 1)) ||
           PatternMatchesString(pattern + 1, str);
     default:  // Non-special character.  Matches itself.
       return *pattern == *str &&
           PatternMatchesString(pattern + 1, str + 1);
   }
 }
 
 bool UnitTestOptions::MatchesFilter(
     const std::string& name, const char* filter) {
   const char *cur_pattern = filter;
   for (;;) {
     if (PatternMatchesString(cur_pattern, name.c_str())) {
       return true;
     }
 
     // Finds the next pattern in the filter.
     cur_pattern = strchr(cur_pattern, ':');
 
     // Returns if no more pattern can be found.
     if (cur_pattern == nullptr) {
       return false;
     }
 
     // Skips the pattern separater (the ':' character).
     cur_pattern++;
   }
 }
 
 // Returns true if and only if the user-specified filter matches the test
 // suite name and the test name.
 bool UnitTestOptions::FilterMatchesTest(const std::string& test_suite_name,
                                         const std::string& test_name) {
   const std::string& full_name = test_suite_name + "." + test_name.c_str();
 
   // Split --gtest_filter at '-', if there is one, to separate into
   // positive filter and negative filter portions
   const char* const p = GTEST_FLAG(filter).c_str();
   const char* const dash = strchr(p, '-');
   std::string positive;
   std::string negative;
   if (dash == nullptr) {
     positive = GTEST_FLAG(filter).c_str();  // Whole string is a positive filter
     negative = "";
   } else {
     positive = std::string(p, dash);   // Everything up to the dash
     negative = std::string(dash + 1);  // Everything after the dash
     if (positive.empty()) {
       // Treat '-test1' as the same as '*-test1'
       positive = kUniversalFilter;
     }
   }
 
   // A filter is a colon-separated list of patterns.  It matches a
   // test if any pattern in it matches the test.
   return (MatchesFilter(full_name, positive.c_str()) &&
           !MatchesFilter(full_name, negative.c_str()));
 }
 
 #if GTEST_HAS_SEH
 // Returns EXCEPTION_EXECUTE_HANDLER if Google Test should handle the
 // given SEH exception, or EXCEPTION_CONTINUE_SEARCH otherwise.
 // This function is useful as an __except condition.
 int UnitTestOptions::GTestShouldProcessSEH(DWORD exception_code) {
   // Google Test should handle a SEH exception if:
   //   1. the user wants it to, AND
   //   2. this is not a breakpoint exception, AND
   //   3. this is not a C++ exception (VC++ implements them via SEH,
   //      apparently).
   //
   // SEH exception code for C++ exceptions.
   // (see http://support.microsoft.com/kb/185294 for more information).
   const DWORD kCxxExceptionCode = 0xe06d7363;
 
   bool should_handle = true;
 
   if (!GTEST_FLAG(catch_exceptions))
     should_handle = false;
   else if (exception_code == EXCEPTION_BREAKPOINT)
     should_handle = false;
   else if (exception_code == kCxxExceptionCode)
     should_handle = false;
 
   return should_handle ? EXCEPTION_EXECUTE_HANDLER : EXCEPTION_CONTINUE_SEARCH;
 }
 #endif  // GTEST_HAS_SEH
 
 }  // namespace internal
 
 // The c'tor sets this object as the test part result reporter used by
 // Google Test.  The 'result' parameter specifies where to report the
 // results. Intercepts only failures from the current thread.
 ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
     TestPartResultArray* result)
     : intercept_mode_(INTERCEPT_ONLY_CURRENT_THREAD),
       result_(result) {
   Init();
 }
 
 // The c'tor sets this object as the test part result reporter used by
 // Google Test.  The 'result' parameter specifies where to report the
 // results.
 ScopedFakeTestPartResultReporter::ScopedFakeTestPartResultReporter(
     InterceptMode intercept_mode, TestPartResultArray* result)
     : intercept_mode_(intercept_mode),
       result_(result) {
   Init();
 }
 
 void ScopedFakeTestPartResultReporter::Init() {
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
     old_reporter_ = impl->GetGlobalTestPartResultReporter();
     impl->SetGlobalTestPartResultReporter(this);
   } else {
     old_reporter_ = impl->GetTestPartResultReporterForCurrentThread();
     impl->SetTestPartResultReporterForCurrentThread(this);
   }
 }
 
 // The d'tor restores the test part result reporter used by Google Test
 // before.
 ScopedFakeTestPartResultReporter::~ScopedFakeTestPartResultReporter() {
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   if (intercept_mode_ == INTERCEPT_ALL_THREADS) {
     impl->SetGlobalTestPartResultReporter(old_reporter_);
   } else {
     impl->SetTestPartResultReporterForCurrentThread(old_reporter_);
   }
 }
 
 // Increments the test part result count and remembers the result.
 // This method is from the TestPartResultReporterInterface interface.
 void ScopedFakeTestPartResultReporter::ReportTestPartResult(
     const TestPartResult& result) {
   result_->Append(result);
 }
 
 namespace internal {
 
 // Returns the type ID of ::testing::Test.  We should always call this
 // instead of GetTypeId< ::testing::Test>() to get the type ID of
 // testing::Test.  This is to work around a suspected linker bug when
 // using Google Test as a framework on Mac OS X.  The bug causes
 // GetTypeId< ::testing::Test>() to return different values depending
 // on whether the call is from the Google Test framework itself or
 // from user test code.  GetTestTypeId() is guaranteed to always
 // return the same value, as it always calls GetTypeId<>() from the
 // gtest.cc, which is within the Google Test framework.
 TypeId GetTestTypeId() {
   return GetTypeId<Test>();
 }
 
 // The value of GetTestTypeId() as seen from within the Google Test
 // library.  This is solely for testing GetTestTypeId().
 extern const TypeId kTestTypeIdInGoogleTest = GetTestTypeId();
 
 // This predicate-formatter checks that 'results' contains a test part
 // failure of the given type and that the failure message contains the
 // given substring.
 static AssertionResult HasOneFailure(const char* /* results_expr */,
                                      const char* /* type_expr */,
                                      const char* /* substr_expr */,
                                      const TestPartResultArray& results,
                                      TestPartResult::Type type,
                                      const std::string& substr) {
   const std::string expected(type == TestPartResult::kFatalFailure ?
                         "1 fatal failure" :
                         "1 non-fatal failure");
   Message msg;
   if (results.size() != 1) {
     msg << "Expected: " << expected << "\n"
         << "  Actual: " << results.size() << " failures";
     for (int i = 0; i < results.size(); i++) {
       msg << "\n" << results.GetTestPartResult(i);
     }
     return AssertionFailure() << msg;
   }
 
   const TestPartResult& r = results.GetTestPartResult(0);
   if (r.type() != type) {
     return AssertionFailure() << "Expected: " << expected << "\n"
                               << "  Actual:\n"
                               << r;
   }
 
   if (strstr(r.message(), substr.c_str()) == nullptr) {
     return AssertionFailure() << "Expected: " << expected << " containing \""
                               << substr << "\"\n"
                               << "  Actual:\n"
                               << r;
   }
 
   return AssertionSuccess();
 }
 
 // The constructor of SingleFailureChecker remembers where to look up
 // test part results, what type of failure we expect, and what
 // substring the failure message should contain.
 SingleFailureChecker::SingleFailureChecker(const TestPartResultArray* results,
                                            TestPartResult::Type type,
                                            const std::string& substr)
     : results_(results), type_(type), substr_(substr) {}
 
 // The destructor of SingleFailureChecker verifies that the given
 // TestPartResultArray contains exactly one failure that has the given
 // type and contains the given substring.  If that's not the case, a
 // non-fatal failure will be generated.
 SingleFailureChecker::~SingleFailureChecker() {
   EXPECT_PRED_FORMAT3(HasOneFailure, *results_, type_, substr_);
 }
 
 DefaultGlobalTestPartResultReporter::DefaultGlobalTestPartResultReporter(
     UnitTestImpl* unit_test) : unit_test_(unit_test) {}
 
 void DefaultGlobalTestPartResultReporter::ReportTestPartResult(
     const TestPartResult& result) {
   unit_test_->current_test_result()->AddTestPartResult(result);
   unit_test_->listeners()->repeater()->OnTestPartResult(result);
 }
 
 DefaultPerThreadTestPartResultReporter::DefaultPerThreadTestPartResultReporter(
     UnitTestImpl* unit_test) : unit_test_(unit_test) {}
 
 void DefaultPerThreadTestPartResultReporter::ReportTestPartResult(
     const TestPartResult& result) {
   unit_test_->GetGlobalTestPartResultReporter()->ReportTestPartResult(result);
 }
 
 // Returns the global test part result reporter.
 TestPartResultReporterInterface*
 UnitTestImpl::GetGlobalTestPartResultReporter() {
   internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
   return global_test_part_result_repoter_;
 }
 
 // Sets the global test part result reporter.
 void UnitTestImpl::SetGlobalTestPartResultReporter(
     TestPartResultReporterInterface* reporter) {
   internal::MutexLock lock(&global_test_part_result_reporter_mutex_);
   global_test_part_result_repoter_ = reporter;
 }
 
 // Returns the test part result reporter for the current thread.
 TestPartResultReporterInterface*
 UnitTestImpl::GetTestPartResultReporterForCurrentThread() {
   return per_thread_test_part_result_reporter_.get();
 }
 
 // Sets the test part result reporter for the current thread.
 void UnitTestImpl::SetTestPartResultReporterForCurrentThread(
     TestPartResultReporterInterface* reporter) {
   per_thread_test_part_result_reporter_.set(reporter);
 }
 
 // Gets the number of successful test suites.
 int UnitTestImpl::successful_test_suite_count() const {
   return CountIf(test_suites_, TestSuitePassed);
 }
 
 // Gets the number of failed test suites.
 int UnitTestImpl::failed_test_suite_count() const {
   return CountIf(test_suites_, TestSuiteFailed);
 }
 
 // Gets the number of all test suites.
 int UnitTestImpl::total_test_suite_count() const {
   return static_cast<int>(test_suites_.size());
 }
 
 // Gets the number of all test suites that contain at least one test
 // that should run.
 int UnitTestImpl::test_suite_to_run_count() const {
   return CountIf(test_suites_, ShouldRunTestSuite);
 }
 
 // Gets the number of successful tests.
 int UnitTestImpl::successful_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::successful_test_count);
 }
 
 // Gets the number of skipped tests.
 int UnitTestImpl::skipped_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::skipped_test_count);
 }
 
 // Gets the number of failed tests.
 int UnitTestImpl::failed_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::failed_test_count);
 }
 
 // Gets the number of disabled tests that will be reported in the XML report.
 int UnitTestImpl::reportable_disabled_test_count() const {
   return SumOverTestSuiteList(test_suites_,
                               &TestSuite::reportable_disabled_test_count);
 }
 
 // Gets the number of disabled tests.
 int UnitTestImpl::disabled_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::disabled_test_count);
 }
 
 // Gets the number of tests to be printed in the XML report.
 int UnitTestImpl::reportable_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::reportable_test_count);
 }
 
 // Gets the number of all tests.
 int UnitTestImpl::total_test_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::total_test_count);
 }
 
 // Gets the number of tests that should run.
 int UnitTestImpl::test_to_run_count() const {
   return SumOverTestSuiteList(test_suites_, &TestSuite::test_to_run_count);
 }
 
 // Returns the current OS stack trace as an std::string.
 //
 // The maximum number of stack frames to be included is specified by
 // the gtest_stack_trace_depth flag.  The skip_count parameter
 // specifies the number of top frames to be skipped, which doesn't
 // count against the number of frames to be included.
 //
 // For example, if Foo() calls Bar(), which in turn calls
 // CurrentOsStackTraceExceptTop(1), Foo() will be included in the
 // trace but Bar() and CurrentOsStackTraceExceptTop() won't.
 std::string UnitTestImpl::CurrentOsStackTraceExceptTop(int skip_count) {
   return os_stack_trace_getter()->CurrentStackTrace(
       static_cast<int>(GTEST_FLAG(stack_trace_depth)),
       skip_count + 1
       // Skips the user-specified number of frames plus this function
       // itself.
       );  // NOLINT
 }
 
 // Returns the current time in milliseconds.
 TimeInMillis GetTimeInMillis() {
 #if GTEST_OS_WINDOWS_MOBILE || defined(__BORLANDC__)
   // Difference between 1970-01-01 and 1601-01-01 in milliseconds.
   // http://analogous.blogspot.com/2005/04/epoch.html
   const TimeInMillis kJavaEpochToWinFileTimeDelta =
     static_cast<TimeInMillis>(116444736UL) * 100000UL;
   const DWORD kTenthMicrosInMilliSecond = 10000;
 
   SYSTEMTIME now_systime;
   FILETIME now_filetime;
   ULARGE_INTEGER now_int64;
   GetSystemTime(&now_systime);
   if (SystemTimeToFileTime(&now_systime, &now_filetime)) {
     now_int64.LowPart = now_filetime.dwLowDateTime;
     now_int64.HighPart = now_filetime.dwHighDateTime;
     now_int64.QuadPart = (now_int64.QuadPart / kTenthMicrosInMilliSecond) -
       kJavaEpochToWinFileTimeDelta;
     return now_int64.QuadPart;
   }
   return 0;
 #elif GTEST_OS_WINDOWS && !GTEST_HAS_GETTIMEOFDAY_
   __timeb64 now;
 
   // MSVC 8 deprecates _ftime64(), so we want to suppress warning 4996
   // (deprecated function) there.
   GTEST_DISABLE_MSC_DEPRECATED_PUSH_()
   _ftime64(&now);
   GTEST_DISABLE_MSC_DEPRECATED_POP_()
 
   return static_cast<TimeInMillis>(now.time) * 1000 + now.millitm;
 #elif GTEST_HAS_GETTIMEOFDAY_
   struct timeval now;
   gettimeofday(&now, nullptr);
   return static_cast<TimeInMillis>(now.tv_sec) * 1000 + now.tv_usec / 1000;
 #else
 # error "Don't know how to get the current time on your system."
 #endif
 }
 
 // Utilities
 
 // class String.
 
 #if GTEST_OS_WINDOWS_MOBILE
 // Creates a UTF-16 wide string from the given ANSI string, allocating
 // memory using new. The caller is responsible for deleting the return
 // value using delete[]. Returns the wide string, or NULL if the
 // input is NULL.
 LPCWSTR String::AnsiToUtf16(const char* ansi) {
   if (!ansi) return nullptr;
   const int length = strlen(ansi);
   const int unicode_length =
       MultiByteToWideChar(CP_ACP, 0, ansi, length, nullptr, 0);
   WCHAR* unicode = new WCHAR[unicode_length + 1];
   MultiByteToWideChar(CP_ACP, 0, ansi, length,
                       unicode, unicode_length);
   unicode[unicode_length] = 0;
   return unicode;
 }
 
 // Creates an ANSI string from the given wide string, allocating
 // memory using new. The caller is responsible for deleting the return
 // value using delete[]. Returns the ANSI string, or NULL if the
 // input is NULL.
 const char* String::Utf16ToAnsi(LPCWSTR utf16_str)  {
   if (!utf16_str) return nullptr;
   const int ansi_length = WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, nullptr,
                                               0, nullptr, nullptr);
   char* ansi = new char[ansi_length + 1];
   WideCharToMultiByte(CP_ACP, 0, utf16_str, -1, ansi, ansi_length, nullptr,
                       nullptr);
   ansi[ansi_length] = 0;
   return ansi;
 }
 
 #endif  // GTEST_OS_WINDOWS_MOBILE
 
 // Compares two C strings.  Returns true if and only if they have the same
 // content.
 //
 // Unlike strcmp(), this function can handle NULL argument(s).  A NULL
 // C string is considered different to any non-NULL C string,
 // including the empty string.
 bool String::CStringEquals(const char * lhs, const char * rhs) {
   if (lhs == nullptr) return rhs == nullptr;
 
   if (rhs == nullptr) return false;
 
   return strcmp(lhs, rhs) == 0;
 }
 
 #if GTEST_HAS_STD_WSTRING
 
 // Converts an array of wide chars to a narrow string using the UTF-8
 // encoding, and streams the result to the given Message object.
 static void StreamWideCharsToMessage(const wchar_t* wstr, size_t length,
                                      Message* msg) {
   for (size_t i = 0; i != length; ) {  // NOLINT
     if (wstr[i] != L'\0') {
       *msg << WideStringToUtf8(wstr + i, static_cast<int>(length - i));
       while (i != length && wstr[i] != L'\0')
         i++;
     } else {
       *msg << '\0';
       i++;
     }
   }
 }
 
 #endif  // GTEST_HAS_STD_WSTRING
 
 void SplitString(const ::std::string& str, char delimiter,
                  ::std::vector< ::std::string>* dest) {
   ::std::vector< ::std::string> parsed;
   ::std::string::size_type pos = 0;
   while (::testing::internal::AlwaysTrue()) {
     const ::std::string::size_type colon = str.find(delimiter, pos);
     if (colon == ::std::string::npos) {
       parsed.push_back(str.substr(pos));
       break;
     } else {
       parsed.push_back(str.substr(pos, colon - pos));
       pos = colon + 1;
     }
   }
   dest->swap(parsed);
 }
 
 }  // namespace internal
 
 // Constructs an empty Message.
 // We allocate the stringstream separately because otherwise each use of
 // ASSERT/EXPECT in a procedure adds over 200 bytes to the procedure's
 // stack frame leading to huge stack frames in some cases; gcc does not reuse
 // the stack space.
 Message::Message() : ss_(new ::std::stringstream) {
   // By default, we want there to be enough precision when printing
   // a double to a Message.
   *ss_ << std::setprecision(std::numeric_limits<double>::digits10 + 2);
 }
 
 // These two overloads allow streaming a wide C string to a Message
 // using the UTF-8 encoding.
 Message& Message::operator <<(const wchar_t* wide_c_str) {
   return *this << internal::String::ShowWideCString(wide_c_str);
 }
 Message& Message::operator <<(wchar_t* wide_c_str) {
   return *this << internal::String::ShowWideCString(wide_c_str);
 }
 
 #if GTEST_HAS_STD_WSTRING
 // Converts the given wide string to a narrow string using the UTF-8
 // encoding, and streams the result to this Message object.
 Message& Message::operator <<(const ::std::wstring& wstr) {
   internal::StreamWideCharsToMessage(wstr.c_str(), wstr.length(), this);
   return *this;
 }
 #endif  // GTEST_HAS_STD_WSTRING
 
 // Gets the text streamed to this object so far as an std::string.
 // Each '\0' character in the buffer is replaced with "\\0".
 std::string Message::GetString() const {
   return internal::StringStreamToString(ss_.get());
 }
 
 // AssertionResult constructors.
 // Used in EXPECT_TRUE/FALSE(assertion_result).
 AssertionResult::AssertionResult(const AssertionResult& other)
     : success_(other.success_),
       message_(other.message_.get() != nullptr
                    ? new ::std::string(*other.message_)
                    : static_cast< ::std::string*>(nullptr)) {}
 
 // Swaps two AssertionResults.
 void AssertionResult::swap(AssertionResult& other) {
   using std::swap;
   swap(success_, other.success_);
   swap(message_, other.message_);
 }
 
 // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
 AssertionResult AssertionResult::operator!() const {
   AssertionResult negation(!success_);
   if (message_.get() != nullptr) negation << *message_;
   return negation;
 }
 
 // Makes a successful assertion result.
 AssertionResult AssertionSuccess() {
   return AssertionResult(true);
 }
 
 // Makes a failed assertion result.
 AssertionResult AssertionFailure() {
   return AssertionResult(false);
 }
 
 // Makes a failed assertion result with the given failure message.
 // Deprecated; use AssertionFailure() << message.
 AssertionResult AssertionFailure(const Message& message) {
   return AssertionFailure() << message;
 }
 
 namespace internal {
 
 namespace edit_distance {
 std::vector<EditType> CalculateOptimalEdits(const std::vector<size_t>& left,
                                             const std::vector<size_t>& right) {
   std::vector<std::vector<double> > costs(
       left.size() + 1, std::vector<double>(right.size() + 1));
   std::vector<std::vector<EditType> > best_move(
       left.size() + 1, std::vector<EditType>(right.size() + 1));
 
   // Populate for empty right.
   for (size_t l_i = 0; l_i < costs.size(); ++l_i) {
     costs[l_i][0] = static_cast<double>(l_i);
     best_move[l_i][0] = kRemove;
   }
   // Populate for empty left.
   for (size_t r_i = 1; r_i < costs[0].size(); ++r_i) {
     costs[0][r_i] = static_cast<double>(r_i);
     best_move[0][r_i] = kAdd;
   }
 
   for (size_t l_i = 0; l_i < left.size(); ++l_i) {
     for (size_t r_i = 0; r_i < right.size(); ++r_i) {
       if (left[l_i] == right[r_i]) {
         // Found a match. Consume it.
         costs[l_i + 1][r_i + 1] = costs[l_i][r_i];
         best_move[l_i + 1][r_i + 1] = kMatch;
         continue;
       }
 
       const double add = costs[l_i + 1][r_i];
       const double remove = costs[l_i][r_i + 1];
       const double replace = costs[l_i][r_i];
       if (add < remove && add < replace) {
         costs[l_i + 1][r_i + 1] = add + 1;
         best_move[l_i + 1][r_i + 1] = kAdd;
       } else if (remove < add && remove < replace) {
         costs[l_i + 1][r_i + 1] = remove + 1;
         best_move[l_i + 1][r_i + 1] = kRemove;
       } else {
         // We make replace a little more expensive than add/remove to lower
         // their priority.
         costs[l_i + 1][r_i + 1] = replace + 1.00001;
         best_move[l_i + 1][r_i + 1] = kReplace;
       }
     }
   }
 
   // Reconstruct the best path. We do it in reverse order.
   std::vector<EditType> best_path;
   for (size_t l_i = left.size(), r_i = right.size(); l_i > 0 || r_i > 0;) {
     EditType move = best_move[l_i][r_i];
     best_path.push_back(move);
     l_i -= move != kAdd;
     r_i -= move != kRemove;
   }
   std::reverse(best_path.begin(), best_path.end());
   return best_path;
 }
 
 namespace {
 
 // Helper class to convert string into ids with deduplication.
 class InternalStrings {
  public:
   size_t GetId(const std::string& str) {
     IdMap::iterator it = ids_.find(str);
     if (it != ids_.end()) return it->second;
     size_t id = ids_.size();
     return ids_[str] = id;
   }
 
  private:
   typedef std::map<std::string, size_t> IdMap;
   IdMap ids_;
 };
 
 }  // namespace
 
 std::vector<EditType> CalculateOptimalEdits(
     const std::vector<std::string>& left,
     const std::vector<std::string>& right) {
   std::vector<size_t> left_ids, right_ids;
   {
     InternalStrings intern_table;
     for (size_t i = 0; i < left.size(); ++i) {
       left_ids.push_back(intern_table.GetId(left[i]));
     }
     for (size_t i = 0; i < right.size(); ++i) {
       right_ids.push_back(intern_table.GetId(right[i]));
     }
   }
   return CalculateOptimalEdits(left_ids, right_ids);
 }
 
 namespace {
 
 // Helper class that holds the state for one hunk and prints it out to the
 // stream.
 // It reorders adds/removes when possible to group all removes before all
 // adds. It also adds the hunk header before printint into the stream.
 class Hunk {
  public:
   Hunk(size_t left_start, size_t right_start)
       : left_start_(left_start),
         right_start_(right_start),
         adds_(),
         removes_(),
         common_() {}
 
   void PushLine(char edit, const char* line) {
     switch (edit) {
       case ' ':
         ++common_;
         FlushEdits();
         hunk_.push_back(std::make_pair(' ', line));
         break;
       case '-':
         ++removes_;
         hunk_removes_.push_back(std::make_pair('-', line));
         break;
       case '+':
         ++adds_;
         hunk_adds_.push_back(std::make_pair('+', line));
         break;
     }
   }
 
   void PrintTo(std::ostream* os) {
     PrintHeader(os);
     FlushEdits();
     for (std::list<std::pair<char, const char*> >::const_iterator it =
              hunk_.begin();
          it != hunk_.end(); ++it) {
       *os << it->first << it->second << "\n";
     }
   }
 
   bool has_edits() const { return adds_ || removes_; }
 
  private:
   void FlushEdits() {
     hunk_.splice(hunk_.end(), hunk_removes_);
     hunk_.splice(hunk_.end(), hunk_adds_);
   }
 
   // Print a unified diff header for one hunk.
   // The format is
   //   "@@ -<left_start>,<left_length> +<right_start>,<right_length> @@"
   // where the left/right parts are omitted if unnecessary.
   void PrintHeader(std::ostream* ss) const {
     *ss << "@@ ";
     if (removes_) {
       *ss << "-" << left_start_ << "," << (removes_ + common_);
     }
     if (removes_ && adds_) {
       *ss << " ";
     }
     if (adds_) {
       *ss << "+" << right_start_ << "," << (adds_ + common_);
     }
     *ss << " @@\n";
   }
 
   size_t left_start_, right_start_;
   size_t adds_, removes_, common_;
   std::list<std::pair<char, const char*> > hunk_, hunk_adds_, hunk_removes_;
 };
 
 }  // namespace
 
 // Create a list of diff hunks in Unified diff format.
 // Each hunk has a header generated by PrintHeader above plus a body with
 // lines prefixed with ' ' for no change, '-' for deletion and '+' for
 // addition.
 // 'context' represents the desired unchanged prefix/suffix around the diff.
 // If two hunks are close enough that their contexts overlap, then they are
 // joined into one hunk.
 std::string CreateUnifiedDiff(const std::vector<std::string>& left,
                               const std::vector<std::string>& right,
                               size_t context) {
   const std::vector<EditType> edits = CalculateOptimalEdits(left, right);
 
   size_t l_i = 0, r_i = 0, edit_i = 0;
   std::stringstream ss;
   while (edit_i < edits.size()) {
     // Find first edit.
     while (edit_i < edits.size() && edits[edit_i] == kMatch) {
       ++l_i;
       ++r_i;
       ++edit_i;
     }
 
     // Find the first line to include in the hunk.
     const size_t prefix_context = std::min(l_i, context);
     Hunk hunk(l_i - prefix_context + 1, r_i - prefix_context + 1);
     for (size_t i = prefix_context; i > 0; --i) {
       hunk.PushLine(' ', left[l_i - i].c_str());
     }
 
     // Iterate the edits until we found enough suffix for the hunk or the input
     // is over.
     size_t n_suffix = 0;
     for (; edit_i < edits.size(); ++edit_i) {
       if (n_suffix >= context) {
         // Continue only if the next hunk is very close.
         auto it = edits.begin() + static_cast<int>(edit_i);
         while (it != edits.end() && *it == kMatch) ++it;
         if (it == edits.end() ||
             static_cast<size_t>(it - edits.begin()) - edit_i >= context) {
           // There is no next edit or it is too far away.
           break;
         }
       }
 
       EditType edit = edits[edit_i];
       // Reset count when a non match is found.
       n_suffix = edit == kMatch ? n_suffix + 1 : 0;
 
       if (edit == kMatch || edit == kRemove || edit == kReplace) {
         hunk.PushLine(edit == kMatch ? ' ' : '-', left[l_i].c_str());
       }
       if (edit == kAdd || edit == kReplace) {
         hunk.PushLine('+', right[r_i].c_str());
       }
 
       // Advance indices, depending on edit type.
       l_i += edit != kAdd;
       r_i += edit != kRemove;
     }
 
     if (!hunk.has_edits()) {
       // We are done. We don't want this hunk.
       break;
     }
 
     hunk.PrintTo(&ss);
   }
   return ss.str();
 }
 
 }  // namespace edit_distance
 
 namespace {
 
 // The string representation of the values received in EqFailure() are already
 // escaped. Split them on escaped '\n' boundaries. Leave all other escaped
 // characters the same.
 std::vector<std::string> SplitEscapedString(const std::string& str) {
   std::vector<std::string> lines;
   size_t start = 0, end = str.size();
   if (end > 2 && str[0] == '"' && str[end - 1] == '"') {
     ++start;
     --end;
   }
   bool escaped = false;
   for (size_t i = start; i + 1 < end; ++i) {
     if (escaped) {
       escaped = false;
       if (str[i] == 'n') {
         lines.push_back(str.substr(start, i - start - 1));
         start = i + 1;
       }
     } else {
       escaped = str[i] == '\\';
     }
   }
   lines.push_back(str.substr(start, end - start));
   return lines;
 }
 
 }  // namespace
 
 // Constructs and returns the message for an equality assertion
 // (e.g. ASSERT_EQ, EXPECT_STREQ, etc) failure.
 //
 // The first four parameters are the expressions used in the assertion
 // and their values, as strings.  For example, for ASSERT_EQ(foo, bar)
 // where foo is 5 and bar is 6, we have:
 //
 //   lhs_expression: "foo"
 //   rhs_expression: "bar"
 //   lhs_value:      "5"
 //   rhs_value:      "6"
 //
 // The ignoring_case parameter is true if and only if the assertion is a
 // *_STRCASEEQ*.  When it's true, the string "Ignoring case" will
 // be inserted into the message.
 AssertionResult EqFailure(const char* lhs_expression,
                           const char* rhs_expression,
                           const std::string& lhs_value,
                           const std::string& rhs_value,
                           bool ignoring_case) {
   Message msg;
   msg << "Expected equality of these values:";
   msg << "\n  " << lhs_expression;
   if (lhs_value != lhs_expression) {
     msg << "\n    Which is: " << lhs_value;
   }
   msg << "\n  " << rhs_expression;
   if (rhs_value != rhs_expression) {
     msg << "\n    Which is: " << rhs_value;
   }
 
   if (ignoring_case) {
     msg << "\nIgnoring case";
   }
 
   if (!lhs_value.empty() && !rhs_value.empty()) {
     const std::vector<std::string> lhs_lines =
         SplitEscapedString(lhs_value);
     const std::vector<std::string> rhs_lines =
         SplitEscapedString(rhs_value);
     if (lhs_lines.size() > 1 || rhs_lines.size() > 1) {
       msg << "\nWith diff:\n"
           << edit_distance::CreateUnifiedDiff(lhs_lines, rhs_lines);
     }
   }
 
   return AssertionFailure() << msg;
 }
 
 // Constructs a failure message for Boolean assertions such as EXPECT_TRUE.
 std::string GetBoolAssertionFailureMessage(
     const AssertionResult& assertion_result,
     const char* expression_text,
     const char* actual_predicate_value,
     const char* expected_predicate_value) {
   const char* actual_message = assertion_result.message();
   Message msg;
   msg << "Value of: " << expression_text
       << "\n  Actual: " << actual_predicate_value;
   if (actual_message[0] != '\0')
     msg << " (" << actual_message << ")";
   msg << "\nExpected: " << expected_predicate_value;
   return msg.GetString();
 }
 
 // Helper function for implementing ASSERT_NEAR.
 AssertionResult DoubleNearPredFormat(const char* expr1,
                                      const char* expr2,
                                      const char* abs_error_expr,
                                      double val1,
                                      double val2,
                                      double abs_error) {
   const double diff = fabs(val1 - val2);
   if (diff <= abs_error) return AssertionSuccess();
 
   return AssertionFailure()
       << "The difference between " << expr1 << " and " << expr2
       << " is " << diff << ", which exceeds " << abs_error_expr << ", where\n"
       << expr1 << " evaluates to " << val1 << ",\n"
       << expr2 << " evaluates to " << val2 << ", and\n"
       << abs_error_expr << " evaluates to " << abs_error << ".";
 }
 
 
 // Helper template for implementing FloatLE() and DoubleLE().
 template <typename RawType>
 AssertionResult FloatingPointLE(const char* expr1,
                                 const char* expr2,
                                 RawType val1,
                                 RawType val2) {
   // Returns success if val1 is less than val2,
   if (val1 < val2) {
     return AssertionSuccess();
   }
 
   // or if val1 is almost equal to val2.
   const FloatingPoint<RawType> lhs(val1), rhs(val2);
   if (lhs.AlmostEquals(rhs)) {
     return AssertionSuccess();
   }
 
   // Note that the above two checks will both fail if either val1 or
   // val2 is NaN, as the IEEE floating-point standard requires that
   // any predicate involving a NaN must return false.
 
   ::std::stringstream val1_ss;
   val1_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
           << val1;
 
   ::std::stringstream val2_ss;
   val2_ss << std::setprecision(std::numeric_limits<RawType>::digits10 + 2)
           << val2;
 
   return AssertionFailure()
       << "Expected: (" << expr1 << ") <= (" << expr2 << ")\n"
       << "  Actual: " << StringStreamToString(&val1_ss) << " vs "
       << StringStreamToString(&val2_ss);
 }
 
 }  // namespace internal
 
 // Asserts that val1 is less than, or almost equal to, val2.  Fails
 // otherwise.  In particular, it fails if either val1 or val2 is NaN.
 AssertionResult FloatLE(const char* expr1, const char* expr2,
                         float val1, float val2) {
   return internal::FloatingPointLE<float>(expr1, expr2, val1, val2);
 }
 
 // Asserts that val1 is less than, or almost equal to, val2.  Fails
 // otherwise.  In particular, it fails if either val1 or val2 is NaN.
 AssertionResult DoubleLE(const char* expr1, const char* expr2,
                          double val1, double val2) {
   return internal::FloatingPointLE<double>(expr1, expr2, val1, val2);
 }
 
 namespace internal {
 
 // The helper function for {ASSERT|EXPECT}_EQ with int or enum
 // arguments.
 AssertionResult CmpHelperEQ(const char* lhs_expression,
                             const char* rhs_expression,
                             BiggestInt lhs,
                             BiggestInt rhs) {
   if (lhs == rhs) {
     return AssertionSuccess();
   }
 
   return EqFailure(lhs_expression,
                    rhs_expression,
                    FormatForComparisonFailureMessage(lhs, rhs),
                    FormatForComparisonFailureMessage(rhs, lhs),
                    false);
 }
 
 // A macro for implementing the helper functions needed to implement
 // ASSERT_?? and EXPECT_?? with integer or enum arguments.  It is here
 // just to avoid copy-and-paste of similar code.
 #define GTEST_IMPL_CMP_HELPER_(op_name, op)\
 AssertionResult CmpHelper##op_name(const char* expr1, const char* expr2, \
                                    BiggestInt val1, BiggestInt val2) {\
   if (val1 op val2) {\
     return AssertionSuccess();\
   } else {\
     return AssertionFailure() \
         << "Expected: (" << expr1 << ") " #op " (" << expr2\
         << "), actual: " << FormatForComparisonFailureMessage(val1, val2)\
         << " vs " << FormatForComparisonFailureMessage(val2, val1);\
   }\
 }
 
 // Implements the helper function for {ASSERT|EXPECT}_NE with int or
 // enum arguments.
 GTEST_IMPL_CMP_HELPER_(NE, !=)
 // Implements the helper function for {ASSERT|EXPECT}_LE with int or
 // enum arguments.
 GTEST_IMPL_CMP_HELPER_(LE, <=)
 // Implements the helper function for {ASSERT|EXPECT}_LT with int or
 // enum arguments.
 GTEST_IMPL_CMP_HELPER_(LT, < )
 // Implements the helper function for {ASSERT|EXPECT}_GE with int or
 // enum arguments.
 GTEST_IMPL_CMP_HELPER_(GE, >=)
 // Implements the helper function for {ASSERT|EXPECT}_GT with int or
 // enum arguments.
 GTEST_IMPL_CMP_HELPER_(GT, > )
 
 #undef GTEST_IMPL_CMP_HELPER_
 
 // The helper function for {ASSERT|EXPECT}_STREQ.
 AssertionResult CmpHelperSTREQ(const char* lhs_expression,
                                const char* rhs_expression,
                                const char* lhs,
                                const char* rhs) {
   if (String::CStringEquals(lhs, rhs)) {
     return AssertionSuccess();
   }
 
   return EqFailure(lhs_expression,
                    rhs_expression,
                    PrintToString(lhs),
                    PrintToString(rhs),
                    false);
 }
 
 // The helper function for {ASSERT|EXPECT}_STRCASEEQ.
 AssertionResult CmpHelperSTRCASEEQ(const char* lhs_expression,
                                    const char* rhs_expression,
                                    const char* lhs,
                                    const char* rhs) {
   if (String::CaseInsensitiveCStringEquals(lhs, rhs)) {
     return AssertionSuccess();
   }
 
   return EqFailure(lhs_expression,
                    rhs_expression,
                    PrintToString(lhs),
                    PrintToString(rhs),
                    true);
 }
 
 // The helper function for {ASSERT|EXPECT}_STRNE.
 AssertionResult CmpHelperSTRNE(const char* s1_expression,
                                const char* s2_expression,
                                const char* s1,
                                const char* s2) {
   if (!String::CStringEquals(s1, s2)) {
     return AssertionSuccess();
   } else {
     return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
                               << s2_expression << "), actual: \""
                               << s1 << "\" vs \"" << s2 << "\"";
   }
 }
 
 // The helper function for {ASSERT|EXPECT}_STRCASENE.
 AssertionResult CmpHelperSTRCASENE(const char* s1_expression,
                                    const char* s2_expression,
                                    const char* s1,
                                    const char* s2) {
   if (!String::CaseInsensitiveCStringEquals(s1, s2)) {
     return AssertionSuccess();
   } else {
     return AssertionFailure()
         << "Expected: (" << s1_expression << ") != ("
         << s2_expression << ") (ignoring case), actual: \""
         << s1 << "\" vs \"" << s2 << "\"";
   }
 }
 
 }  // namespace internal
 
 namespace {
 
 // Helper functions for implementing IsSubString() and IsNotSubstring().
 
 // This group of overloaded functions return true if and only if needle
 // is a substring of haystack.  NULL is considered a substring of
 // itself only.
 
 bool IsSubstringPred(const char* needle, const char* haystack) {
   if (needle == nullptr || haystack == nullptr) return needle == haystack;
 
   return strstr(haystack, needle) != nullptr;
 }
 
 bool IsSubstringPred(const wchar_t* needle, const wchar_t* haystack) {
   if (needle == nullptr || haystack == nullptr) return needle == haystack;
 
   return wcsstr(haystack, needle) != nullptr;
 }
 
 // StringType here can be either ::std::string or ::std::wstring.
 template <typename StringType>
 bool IsSubstringPred(const StringType& needle,
                      const StringType& haystack) {
   return haystack.find(needle) != StringType::npos;
 }
 
 // This function implements either IsSubstring() or IsNotSubstring(),
 // depending on the value of the expected_to_be_substring parameter.
 // StringType here can be const char*, const wchar_t*, ::std::string,
 // or ::std::wstring.
 template <typename StringType>
 AssertionResult IsSubstringImpl(
     bool expected_to_be_substring,
     const char* needle_expr, const char* haystack_expr,
     const StringType& needle, const StringType& haystack) {
   if (IsSubstringPred(needle, haystack) == expected_to_be_substring)
     return AssertionSuccess();
 
   const bool is_wide_string = sizeof(needle[0]) > 1;
   const char* const begin_string_quote = is_wide_string ? "L\"" : "\"";
   return AssertionFailure()
       << "Value of: " << needle_expr << "\n"
       << "  Actual: " << begin_string_quote << needle << "\"\n"
       << "Expected: " << (expected_to_be_substring ? "" : "not ")
       << "a substring of " << haystack_expr << "\n"
       << "Which is: " << begin_string_quote << haystack << "\"";
 }
 
 }  // namespace
 
 // IsSubstring() and IsNotSubstring() check whether needle is a
 // substring of haystack (NULL is considered a substring of itself
 // only), and return an appropriate error message when they fail.
 
 AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const char* needle, const char* haystack) {
   return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const wchar_t* needle, const wchar_t* haystack) {
   return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const char* needle, const char* haystack) {
   return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const wchar_t* needle, const wchar_t* haystack) {
   return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::string& needle, const ::std::string& haystack) {
   return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::string& needle, const ::std::string& haystack) {
   return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
 }
 
 #if GTEST_HAS_STD_WSTRING
 AssertionResult IsSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::wstring& needle, const ::std::wstring& haystack) {
   return IsSubstringImpl(true, needle_expr, haystack_expr, needle, haystack);
 }
 
 AssertionResult IsNotSubstring(
     const char* needle_expr, const char* haystack_expr,
     const ::std::wstring& needle, const ::std::wstring& haystack) {
   return IsSubstringImpl(false, needle_expr, haystack_expr, needle, haystack);
 }
 #endif  // GTEST_HAS_STD_WSTRING
 
 namespace internal {
 
 #if GTEST_OS_WINDOWS
 
 namespace {
 
 // Helper function for IsHRESULT{SuccessFailure} predicates
 AssertionResult HRESULTFailureHelper(const char* expr,
                                      const char* expected,
                                      long hr) {  // NOLINT
 # if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_WINDOWS_TV_TITLE
 
   // Windows CE doesn't support FormatMessage.
   const char error_text[] = "";
 
 # else
 
   // Looks up the human-readable system message for the HRESULT code
   // and since we're not passing any params to FormatMessage, we don't
   // want inserts expanded.
   const DWORD kFlags = FORMAT_MESSAGE_FROM_SYSTEM |
                        FORMAT_MESSAGE_IGNORE_INSERTS;
   const DWORD kBufSize = 4096;
   // Gets the system's human readable message string for this HRESULT.
   char error_text[kBufSize] = { '\0' };
   DWORD message_length = ::FormatMessageA(kFlags,
                                           0,   // no source, we're asking system
                                           static_cast<DWORD>(hr),  // the error
                                           0,   // no line width restrictions
                                           error_text,  // output buffer
                                           kBufSize,    // buf size
                                           nullptr);  // no arguments for inserts
   // Trims tailing white space (FormatMessage leaves a trailing CR-LF)
   for (; message_length && IsSpace(error_text[message_length - 1]);
           --message_length) {
     error_text[message_length - 1] = '\0';
   }
 
 # endif  // GTEST_OS_WINDOWS_MOBILE
 
   const std::string error_hex("0x" + String::FormatHexInt(hr));
   return ::testing::AssertionFailure()
       << "Expected: " << expr << " " << expected << ".\n"
       << "  Actual: " << error_hex << " " << error_text << "\n";
 }
 
 }  // namespace
 
 AssertionResult IsHRESULTSuccess(const char* expr, long hr) {  // NOLINT
   if (SUCCEEDED(hr)) {
     return AssertionSuccess();
   }
   return HRESULTFailureHelper(expr, "succeeds", hr);
 }
 
 AssertionResult IsHRESULTFailure(const char* expr, long hr) {  // NOLINT
   if (FAILED(hr)) {
     return AssertionSuccess();
   }
   return HRESULTFailureHelper(expr, "fails", hr);
 }
 
 #endif  // GTEST_OS_WINDOWS
 
 // Utility functions for encoding Unicode text (wide strings) in
 // UTF-8.
 
 // A Unicode code-point can have up to 21 bits, and is encoded in UTF-8
 // like this:
 //
 // Code-point length   Encoding
 //   0 -  7 bits       0xxxxxxx
 //   8 - 11 bits       110xxxxx 10xxxxxx
 //  12 - 16 bits       1110xxxx 10xxxxxx 10xxxxxx
 //  17 - 21 bits       11110xxx 10xxxxxx 10xxxxxx 10xxxxxx
 
 // The maximum code-point a one-byte UTF-8 sequence can represent.
 constexpr uint32_t kMaxCodePoint1 = (static_cast<uint32_t>(1) <<  7) - 1;
 
 // The maximum code-point a two-byte UTF-8 sequence can represent.
 constexpr uint32_t kMaxCodePoint2 = (static_cast<uint32_t>(1) << (5 + 6)) - 1;
 
 // The maximum code-point a three-byte UTF-8 sequence can represent.
 constexpr uint32_t kMaxCodePoint3 = (static_cast<uint32_t>(1) << (4 + 2*6)) - 1;
 
 // The maximum code-point a four-byte UTF-8 sequence can represent.
 constexpr uint32_t kMaxCodePoint4 = (static_cast<uint32_t>(1) << (3 + 3*6)) - 1;
 
 // Chops off the n lowest bits from a bit pattern.  Returns the n
 // lowest bits.  As a side effect, the original bit pattern will be
 // shifted to the right by n bits.
 inline uint32_t ChopLowBits(uint32_t* bits, int n) {
   const uint32_t low_bits = *bits & ((static_cast<uint32_t>(1) << n) - 1);
   *bits >>= n;
   return low_bits;
 }
 
 // Converts a Unicode code point to a narrow string in UTF-8 encoding.
 // code_point parameter is of type uint32_t because wchar_t may not be
 // wide enough to contain a code point.
 // If the code_point is not a valid Unicode code point
 // (i.e. outside of Unicode range U+0 to U+10FFFF) it will be converted
 // to "(Invalid Unicode 0xXXXXXXXX)".
 std::string CodePointToUtf8(uint32_t code_point) {
   if (code_point > kMaxCodePoint4) {
     return "(Invalid Unicode 0x" + String::FormatHexUInt32(code_point) + ")";
   }
 
   char str[5];  // Big enough for the largest valid code point.
   if (code_point <= kMaxCodePoint1) {
     str[1] = '\0';
     str[0] = static_cast<char>(code_point);                          // 0xxxxxxx
   } else if (code_point <= kMaxCodePoint2) {
     str[2] = '\0';
     str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[0] = static_cast<char>(0xC0 | code_point);                   // 110xxxxx
   } else if (code_point <= kMaxCodePoint3) {
     str[3] = '\0';
     str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[0] = static_cast<char>(0xE0 | code_point);                   // 1110xxxx
   } else {  // code_point <= kMaxCodePoint4
     str[4] = '\0';
     str[3] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[2] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[1] = static_cast<char>(0x80 | ChopLowBits(&code_point, 6));  // 10xxxxxx
     str[0] = static_cast<char>(0xF0 | code_point);                   // 11110xxx
   }
   return str;
 }
 
 // The following two functions only make sense if the system
 // uses UTF-16 for wide string encoding. All supported systems
 // with 16 bit wchar_t (Windows, Cygwin) do use UTF-16.
 
 // Determines if the arguments constitute UTF-16 surrogate pair
 // and thus should be combined into a single Unicode code point
 // using CreateCodePointFromUtf16SurrogatePair.
 inline bool IsUtf16SurrogatePair(wchar_t first, wchar_t second) {
   return sizeof(wchar_t) == 2 &&
       (first & 0xFC00) == 0xD800 && (second & 0xFC00) == 0xDC00;
 }
 
 // Creates a Unicode code point from UTF16 surrogate pair.
 inline uint32_t CreateCodePointFromUtf16SurrogatePair(wchar_t first,
                                                       wchar_t second) {
   const auto first_u = static_cast<uint32_t>(first);
   const auto second_u = static_cast<uint32_t>(second);
   const uint32_t mask = (1 << 10) - 1;
   return (sizeof(wchar_t) == 2)
              ? (((first_u & mask) << 10) | (second_u & mask)) + 0x10000
              :
              // This function should not be called when the condition is
              // false, but we provide a sensible default in case it is.
              first_u;
 }
 
 // Converts a wide string to a narrow string in UTF-8 encoding.
 // The wide string is assumed to have the following encoding:
 //   UTF-16 if sizeof(wchar_t) == 2 (on Windows, Cygwin)
 //   UTF-32 if sizeof(wchar_t) == 4 (on Linux)
 // Parameter str points to a null-terminated wide string.
 // Parameter num_chars may additionally limit the number
 // of wchar_t characters processed. -1 is used when the entire string
 // should be processed.
 // If the string contains code points that are not valid Unicode code points
 // (i.e. outside of Unicode range U+0 to U+10FFFF) they will be output
 // as '(Invalid Unicode 0xXXXXXXXX)'. If the string is in UTF16 encoding
 // and contains invalid UTF-16 surrogate pairs, values in those pairs
 // will be encoded as individual Unicode characters from Basic Normal Plane.
 std::string WideStringToUtf8(const wchar_t* str, int num_chars) {
   if (num_chars == -1)
     num_chars = static_cast<int>(wcslen(str));
 
   ::std::stringstream stream;
   for (int i = 0; i < num_chars; ++i) {
     uint32_t unicode_code_point;
 
     if (str[i] == L'\0') {
       break;
     } else if (i + 1 < num_chars && IsUtf16SurrogatePair(str[i], str[i + 1])) {
       unicode_code_point = CreateCodePointFromUtf16SurrogatePair(str[i],
                                                                  str[i + 1]);
       i++;
     } else {
       unicode_code_point = static_cast<uint32_t>(str[i]);
     }
 
     stream << CodePointToUtf8(unicode_code_point);
   }
   return StringStreamToString(&stream);
 }
 
 // Converts a wide C string to an std::string using the UTF-8 encoding.
 // NULL will be converted to "(null)".
 std::string String::ShowWideCString(const wchar_t * wide_c_str) {
   if (wide_c_str == nullptr) return "(null)";
 
   return internal::WideStringToUtf8(wide_c_str, -1);
 }
 
 // Compares two wide C strings.  Returns true if and only if they have the
 // same content.
 //
 // Unlike wcscmp(), this function can handle NULL argument(s).  A NULL
 // C string is considered different to any non-NULL C string,
 // including the empty string.
 bool String::WideCStringEquals(const wchar_t * lhs, const wchar_t * rhs) {
   if (lhs == nullptr) return rhs == nullptr;
 
   if (rhs == nullptr) return false;
 
   return wcscmp(lhs, rhs) == 0;
 }
 
 // Helper function for *_STREQ on wide strings.
 AssertionResult CmpHelperSTREQ(const char* lhs_expression,
                                const char* rhs_expression,
                                const wchar_t* lhs,
                                const wchar_t* rhs) {
   if (String::WideCStringEquals(lhs, rhs)) {
     return AssertionSuccess();
   }
 
   return EqFailure(lhs_expression,
                    rhs_expression,
                    PrintToString(lhs),
                    PrintToString(rhs),
                    false);
 }
 
 // Helper function for *_STRNE on wide strings.
 AssertionResult CmpHelperSTRNE(const char* s1_expression,
                                const char* s2_expression,
                                const wchar_t* s1,
                                const wchar_t* s2) {
   if (!String::WideCStringEquals(s1, s2)) {
     return AssertionSuccess();
   }
 
   return AssertionFailure() << "Expected: (" << s1_expression << ") != ("
                             << s2_expression << "), actual: "
                             << PrintToString(s1)
                             << " vs " << PrintToString(s2);
 }
 
 // Compares two C strings, ignoring case.  Returns true if and only if they have
 // the same content.
 //
 // Unlike strcasecmp(), this function can handle NULL argument(s).  A
 // NULL C string is considered different to any non-NULL C string,
 // including the empty string.
 bool String::CaseInsensitiveCStringEquals(const char * lhs, const char * rhs) {
   if (lhs == nullptr) return rhs == nullptr;
   if (rhs == nullptr) return false;
   return posix::StrCaseCmp(lhs, rhs) == 0;
 }
 
 // Compares two wide C strings, ignoring case.  Returns true if and only if they
 // have the same content.
 //
 // Unlike wcscasecmp(), this function can handle NULL argument(s).
 // A NULL C string is considered different to any non-NULL wide C string,
 // including the empty string.
 // NB: The implementations on different platforms slightly differ.
 // On windows, this method uses _wcsicmp which compares according to LC_CTYPE
 // environment variable. On GNU platform this method uses wcscasecmp
 // which compares according to LC_CTYPE category of the current locale.
 // On MacOS X, it uses towlower, which also uses LC_CTYPE category of the
 // current locale.
 bool String::CaseInsensitiveWideCStringEquals(const wchar_t* lhs,
                                               const wchar_t* rhs) {
   if (lhs == nullptr) return rhs == nullptr;
 
   if (rhs == nullptr) return false;
 
 #if GTEST_OS_WINDOWS
   return _wcsicmp(lhs, rhs) == 0;
 #elif GTEST_OS_LINUX && !GTEST_OS_LINUX_ANDROID
   return wcscasecmp(lhs, rhs) == 0;
 #else
   // Android, Mac OS X and Cygwin don't define wcscasecmp.
   // Other unknown OSes may not define it either.
   wint_t left, right;
   do {
     left = towlower(static_cast<wint_t>(*lhs++));
     right = towlower(static_cast<wint_t>(*rhs++));
   } while (left && left == right);
   return left == right;
 #endif  // OS selector
 }
 
 // Returns true if and only if str ends with the given suffix, ignoring case.
 // Any string is considered to end with an empty suffix.
 bool String::EndsWithCaseInsensitive(
     const std::string& str, const std::string& suffix) {
   const size_t str_len = str.length();
   const size_t suffix_len = suffix.length();
   return (str_len >= suffix_len) &&
          CaseInsensitiveCStringEquals(str.c_str() + str_len - suffix_len,
                                       suffix.c_str());
 }
 
 // Formats an int value as "%02d".
 std::string String::FormatIntWidth2(int value) {
   std::stringstream ss;
   ss << std::setfill('0') << std::setw(2) << value;
   return ss.str();
 }
 
 // Formats an int value as "%X".
 std::string String::FormatHexUInt32(uint32_t value) {
   std::stringstream ss;
   ss << std::hex << std::uppercase << value;
   return ss.str();
 }
 
 // Formats an int value as "%X".
 std::string String::FormatHexInt(int value) {
   return FormatHexUInt32(static_cast<uint32_t>(value));
 }
 
 // Formats a byte as "%02X".
 std::string String::FormatByte(unsigned char value) {
   std::stringstream ss;
   ss << std::setfill('0') << std::setw(2) << std::hex << std::uppercase
      << static_cast<unsigned int>(value);
   return ss.str();
 }
 
 // Converts the buffer in a stringstream to an std::string, converting NUL
 // bytes to "\\0" along the way.
 std::string StringStreamToString(::std::stringstream* ss) {
   const ::std::string& str = ss->str();
   const char* const start = str.c_str();
   const char* const end = start + str.length();
 
   std::string result;
   result.reserve(static_cast<size_t>(2 * (end - start)));
   for (const char* ch = start; ch != end; ++ch) {
     if (*ch == '\0') {
       result += "\\0";  // Replaces NUL with "\\0";
     } else {
       result += *ch;
     }
   }
 
   return result;
 }
 
 // Appends the user-supplied message to the Google-Test-generated message.
 std::string AppendUserMessage(const std::string& gtest_msg,
                               const Message& user_msg) {
   // Appends the user message if it's non-empty.
   const std::string user_msg_string = user_msg.GetString();
   if (user_msg_string.empty()) {
     return gtest_msg;
   }
 
   return gtest_msg + "\n" + user_msg_string;
 }
 
 }  // namespace internal
 
 // class TestResult
 
 // Creates an empty TestResult.
 TestResult::TestResult()
     : death_test_count_(0), start_timestamp_(0), elapsed_time_(0) {}
 
 // D'tor.
 TestResult::~TestResult() {
 }
 
 // Returns the i-th test part result among all the results. i can
 // range from 0 to total_part_count() - 1. If i is not in that range,
 // aborts the program.
 const TestPartResult& TestResult::GetTestPartResult(int i) const {
   if (i < 0 || i >= total_part_count())
     internal::posix::Abort();
   return test_part_results_.at(static_cast<size_t>(i));
 }
 
 // Returns the i-th test property. i can range from 0 to
 // test_property_count() - 1. If i is not in that range, aborts the
 // program.
 const TestProperty& TestResult::GetTestProperty(int i) const {
   if (i < 0 || i >= test_property_count())
     internal::posix::Abort();
   return test_properties_.at(static_cast<size_t>(i));
 }
 
 // Clears the test part results.
 void TestResult::ClearTestPartResults() {
   test_part_results_.clear();
 }
 
 // Adds a test part result to the list.
 void TestResult::AddTestPartResult(const TestPartResult& test_part_result) {
   test_part_results_.push_back(test_part_result);
 }
 
 // Adds a test property to the list. If a property with the same key as the
 // supplied property is already represented, the value of this test_property
 // replaces the old value for that key.
 void TestResult::RecordProperty(const std::string& xml_element,
                                 const TestProperty& test_property) {
   if (!ValidateTestProperty(xml_element, test_property)) {
     return;
   }
   internal::MutexLock lock(&test_properites_mutex_);
   const std::vector<TestProperty>::iterator property_with_matching_key =
       std::find_if(test_properties_.begin(), test_properties_.end(),
                    internal::TestPropertyKeyIs(test_property.key()));
   if (property_with_matching_key == test_properties_.end()) {
     test_properties_.push_back(test_property);
     return;
   }
   property_with_matching_key->SetValue(test_property.value());
 }
 
 // The list of reserved attributes used in the <testsuites> element of XML
 // output.
 static const char* const kReservedTestSuitesAttributes[] = {
   "disabled",
   "errors",
   "failures",
   "name",
   "random_seed",
   "tests",
   "time",
   "timestamp"
 };
 
 // The list of reserved attributes used in the <testsuite> element of XML
 // output.
 static const char* const kReservedTestSuiteAttributes[] = {
     "disabled", "errors", "failures", "name", "tests", "time", "timestamp"};
 
 // The list of reserved attributes used in the <testcase> element of XML output.
 static const char* const kReservedTestCaseAttributes[] = {
     "classname",   "name", "status", "time",  "type_param",
     "value_param", "file", "line"};
 
 // Use a slightly different set for allowed output to ensure existing tests can
 // still RecordProperty("result") or "RecordProperty(timestamp")
 static const char* const kReservedOutputTestCaseAttributes[] = {
     "classname",   "name", "status", "time",   "type_param",
     "value_param", "file", "line",   "result", "timestamp"};
 
 template <size_t kSize>
 std::vector<std::string> ArrayAsVector(const char* const (&array)[kSize]) {
   return std::vector<std::string>(array, array + kSize);
 }
 
 static std::vector<std::string> GetReservedAttributesForElement(
     const std::string& xml_element) {
   if (xml_element == "testsuites") {
     return ArrayAsVector(kReservedTestSuitesAttributes);
   } else if (xml_element == "testsuite") {
     return ArrayAsVector(kReservedTestSuiteAttributes);
   } else if (xml_element == "testcase") {
     return ArrayAsVector(kReservedTestCaseAttributes);
   } else {
     GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
   }
   // This code is unreachable but some compilers may not realizes that.
   return std::vector<std::string>();
 }
 
 // TODO(jdesprez): Merge the two getReserved attributes once skip is improved
 static std::vector<std::string> GetReservedOutputAttributesForElement(
     const std::string& xml_element) {
   if (xml_element == "testsuites") {
     return ArrayAsVector(kReservedTestSuitesAttributes);
   } else if (xml_element == "testsuite") {
     return ArrayAsVector(kReservedTestSuiteAttributes);
   } else if (xml_element == "testcase") {
     return ArrayAsVector(kReservedOutputTestCaseAttributes);
   } else {
     GTEST_CHECK_(false) << "Unrecognized xml_element provided: " << xml_element;
   }
   // This code is unreachable but some compilers may not realizes that.
   return std::vector<std::string>();
 }
 
 static std::string FormatWordList(const std::vector<std::string>& words) {
   Message word_list;
   for (size_t i = 0; i < words.size(); ++i) {
     if (i > 0 && words.size() > 2) {
       word_list << ", ";
     }
     if (i == words.size() - 1) {
       word_list << "and ";
     }
     word_list << "'" << words[i] << "'";
   }
   return word_list.GetString();
 }
 
 static bool ValidateTestPropertyName(
     const std::string& property_name,
     const std::vector<std::string>& reserved_names) {
   if (std::find(reserved_names.begin(), reserved_names.end(), property_name) !=
           reserved_names.end()) {
     ADD_FAILURE() << "Reserved key used in RecordProperty(): " << property_name
                   << " (" << FormatWordList(reserved_names)
                   << " are reserved by " << GTEST_NAME_ << ")";
     return false;
   }
   return true;
 }
 
 // Adds a failure if the key is a reserved attribute of the element named
 // xml_element.  Returns true if the property is valid.
 bool TestResult::ValidateTestProperty(const std::string& xml_element,
                                       const TestProperty& test_property) {
   return ValidateTestPropertyName(test_property.key(),
                                   GetReservedAttributesForElement(xml_element));
 }
 
 // Clears the object.
 void TestResult::Clear() {
   test_part_results_.clear();
   test_properties_.clear();
   death_test_count_ = 0;
   elapsed_time_ = 0;
 }
 
 // Returns true off the test part was skipped.
 static bool TestPartSkipped(const TestPartResult& result) {
   return result.skipped();
 }
 
 // Returns true if and only if the test was skipped.
 bool TestResult::Skipped() const {
   return !Failed() && CountIf(test_part_results_, TestPartSkipped) > 0;
 }
 
 // Returns true if and only if the test failed.
 bool TestResult::Failed() const {
   for (int i = 0; i < total_part_count(); ++i) {
     if (GetTestPartResult(i).failed())
       return true;
   }
   return false;
 }
 
 // Returns true if and only if the test part fatally failed.
 static bool TestPartFatallyFailed(const TestPartResult& result) {
   return result.fatally_failed();
 }
 
 // Returns true if and only if the test fatally failed.
 bool TestResult::HasFatalFailure() const {
   return CountIf(test_part_results_, TestPartFatallyFailed) > 0;
 }
 
 // Returns true if and only if the test part non-fatally failed.
 static bool TestPartNonfatallyFailed(const TestPartResult& result) {
   return result.nonfatally_failed();
 }
 
 // Returns true if and only if the test has a non-fatal failure.
 bool TestResult::HasNonfatalFailure() const {
   return CountIf(test_part_results_, TestPartNonfatallyFailed) > 0;
 }
 
 // Gets the number of all test parts.  This is the sum of the number
 // of successful test parts and the number of failed test parts.
 int TestResult::total_part_count() const {
   return static_cast<int>(test_part_results_.size());
 }
 
 // Returns the number of the test properties.
 int TestResult::test_property_count() const {
   return static_cast<int>(test_properties_.size());
 }
 
 // class Test
 
 // Creates a Test object.
 
 // The c'tor saves the states of all flags.
 Test::Test()
     : gtest_flag_saver_(new GTEST_FLAG_SAVER_) {
 }
 
 // The d'tor restores the states of all flags.  The actual work is
 // done by the d'tor of the gtest_flag_saver_ field, and thus not
 // visible here.
 Test::~Test() {
 }
 
 // Sets up the test fixture.
 //
 // A sub-class may override this.
 void Test::SetUp() {
 }
 
 // Tears down the test fixture.
 //
 // A sub-class may override this.
 void Test::TearDown() {
 }
 
 // Allows user supplied key value pairs to be recorded for later output.
 void Test::RecordProperty(const std::string& key, const std::string& value) {
   UnitTest::GetInstance()->RecordProperty(key, value);
 }
 
 // Allows user supplied key value pairs to be recorded for later output.
 void Test::RecordProperty(const std::string& key, int value) {
   Message value_message;
   value_message << value;
   RecordProperty(key, value_message.GetString().c_str());
 }
 
 namespace internal {
 
 void ReportFailureInUnknownLocation(TestPartResult::Type result_type,
                                     const std::string& message) {
   // This function is a friend of UnitTest and as such has access to
   // AddTestPartResult.
   UnitTest::GetInstance()->AddTestPartResult(
       result_type,
       nullptr,  // No info about the source file where the exception occurred.
       -1,       // We have no info on which line caused the exception.
       message,
       "");  // No stack trace, either.
 }
 
 }  // namespace internal
 
 // Google Test requires all tests in the same test suite to use the same test
 // fixture class.  This function checks if the current test has the
 // same fixture class as the first test in the current test suite.  If
 // yes, it returns true; otherwise it generates a Google Test failure and
 // returns false.
 bool Test::HasSameFixtureClass() {
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   const TestSuite* const test_suite = impl->current_test_suite();
 
   // Info about the first test in the current test suite.
   const TestInfo* const first_test_info = test_suite->test_info_list()[0];
   const internal::TypeId first_fixture_id = first_test_info->fixture_class_id_;
   const char* const first_test_name = first_test_info->name();
 
   // Info about the current test.
   const TestInfo* const this_test_info = impl->current_test_info();
   const internal::TypeId this_fixture_id = this_test_info->fixture_class_id_;
   const char* const this_test_name = this_test_info->name();
 
   if (this_fixture_id != first_fixture_id) {
     // Is the first test defined using TEST?
     const bool first_is_TEST = first_fixture_id == internal::GetTestTypeId();
     // Is this test defined using TEST?
     const bool this_is_TEST = this_fixture_id == internal::GetTestTypeId();
 
     if (first_is_TEST || this_is_TEST) {
       // Both TEST and TEST_F appear in same test suite, which is incorrect.
       // Tell the user how to fix this.
 
       // Gets the name of the TEST and the name of the TEST_F.  Note
       // that first_is_TEST and this_is_TEST cannot both be true, as
       // the fixture IDs are different for the two tests.
       const char* const TEST_name =
           first_is_TEST ? first_test_name : this_test_name;
       const char* const TEST_F_name =
           first_is_TEST ? this_test_name : first_test_name;
 
       ADD_FAILURE()
           << "All tests in the same test suite must use the same test fixture\n"
           << "class, so mixing TEST_F and TEST in the same test suite is\n"
           << "illegal.  In test suite " << this_test_info->test_suite_name()
           << ",\n"
           << "test " << TEST_F_name << " is defined using TEST_F but\n"
           << "test " << TEST_name << " is defined using TEST.  You probably\n"
           << "want to change the TEST to TEST_F or move it to another test\n"
           << "case.";
     } else {
       // Two fixture classes with the same name appear in two different
       // namespaces, which is not allowed. Tell the user how to fix this.
       ADD_FAILURE()
           << "All tests in the same test suite must use the same test fixture\n"
           << "class.  However, in test suite "
           << this_test_info->test_suite_name() << ",\n"
           << "you defined test " << first_test_name << " and test "
           << this_test_name << "\n"
           << "using two different test fixture classes.  This can happen if\n"
           << "the two classes are from different namespaces or translation\n"
           << "units and have the same name.  You should probably rename one\n"
           << "of the classes to put the tests into different test suites.";
     }
     return false;
   }
 
   return true;
 }
 
 #if GTEST_HAS_SEH
 
 // Adds an "exception thrown" fatal failure to the current test.  This
 // function returns its result via an output parameter pointer because VC++
 // prohibits creation of objects with destructors on stack in functions
 // using __try (see error C2712).
 static std::string* FormatSehExceptionMessage(DWORD exception_code,
                                               const char* location) {
   Message message;
   message << "SEH exception with code 0x" << std::setbase(16) <<
     exception_code << std::setbase(10) << " thrown in " << location << ".";
 
   return new std::string(message.GetString());
 }
 
 #endif  // GTEST_HAS_SEH
 
 namespace internal {
 
 #if GTEST_HAS_EXCEPTIONS
 
 // Adds an "exception thrown" fatal failure to the current test.
 static std::string FormatCxxExceptionMessage(const char* description,
                                              const char* location) {
   Message message;
   if (description != nullptr) {
     message << "C++ exception with description \"" << description << "\"";
   } else {
     message << "Unknown C++ exception";
   }
   message << " thrown in " << location << ".";
 
   return message.GetString();
 }
 
 static std::string PrintTestPartResultToString(
     const TestPartResult& test_part_result);
 
 GoogleTestFailureException::GoogleTestFailureException(
     const TestPartResult& failure)
     : ::std::runtime_error(PrintTestPartResultToString(failure).c_str()) {}
 
 #endif  // GTEST_HAS_EXCEPTIONS
 
 // We put these helper functions in the internal namespace as IBM's xlC
 // compiler rejects the code if they were declared static.
 
 // Runs the given method and handles SEH exceptions it throws, when
 // SEH is supported; returns the 0-value for type Result in case of an
 // SEH exception.  (Microsoft compilers cannot handle SEH and C++
 // exceptions in the same function.  Therefore, we provide a separate
 // wrapper function for handling SEH exceptions.)
 template <class T, typename Result>
 Result HandleSehExceptionsInMethodIfSupported(
     T* object, Result (T::*method)(), const char* location) {
 #if GTEST_HAS_SEH
   __try {
     return (object->*method)();
   } __except (internal::UnitTestOptions::GTestShouldProcessSEH(  // NOLINT
       GetExceptionCode())) {
     // We create the exception message on the heap because VC++ prohibits
     // creation of objects with destructors on stack in functions using __try
     // (see error C2712).
     std::string* exception_message = FormatSehExceptionMessage(
         GetExceptionCode(), location);
     internal::ReportFailureInUnknownLocation(TestPartResult::kFatalFailure,
                                              *exception_message);
     delete exception_message;
     return static_cast<Result>(0);
   }
 #else
   (void)location;
   return (object->*method)();
 #endif  // GTEST_HAS_SEH
 }
 
 // Runs the given method and catches and reports C++ and/or SEH-style
 // exceptions, if they are supported; returns the 0-value for type
 // Result in case of an SEH exception.
 template <class T, typename Result>
 Result HandleExceptionsInMethodIfSupported(
     T* object, Result (T::*method)(), const char* location) {
   // NOTE: The user code can affect the way in which Google Test handles
   // exceptions by setting GTEST_FLAG(catch_exceptions), but only before
   // RUN_ALL_TESTS() starts. It is technically possible to check the flag
   // after the exception is caught and either report or re-throw the
   // exception based on the flag's value:
   //
   // try {
   //   // Perform the test method.
   // } catch (...) {
   //   if (GTEST_FLAG(catch_exceptions))
   //     // Report the exception as failure.
   //   else
   //     throw;  // Re-throws the original exception.
   // }
   //
   // However, the purpose of this flag is to allow the program to drop into
   // the debugger when the exception is thrown. On most platforms, once the
   // control enters the catch block, the exception origin information is
   // lost and the debugger will stop the program at the point of the
   // re-throw in this function -- instead of at the point of the original
   // throw statement in the code under test.  For this reason, we perform
   // the check early, sacrificing the ability to affect Google Test's
   // exception handling in the method where the exception is thrown.
   if (internal::GetUnitTestImpl()->catch_exceptions()) {
 #if GTEST_HAS_EXCEPTIONS
     try {
       return HandleSehExceptionsInMethodIfSupported(object, method, location);
     } catch (const AssertionException&) {  // NOLINT
       // This failure was reported already.
     } catch (const internal::GoogleTestFailureException&) {  // NOLINT
       // This exception type can only be thrown by a failed Google
       // Test assertion with the intention of letting another testing
       // framework catch it.  Therefore we just re-throw it.
       throw;
     } catch (const std::exception& e) {  // NOLINT
       internal::ReportFailureInUnknownLocation(
           TestPartResult::kFatalFailure,
           FormatCxxExceptionMessage(e.what(), location));
     } catch (...) {  // NOLINT
       internal::ReportFailureInUnknownLocation(
           TestPartResult::kFatalFailure,
           FormatCxxExceptionMessage(nullptr, location));
     }
     return static_cast<Result>(0);
 #else
     return HandleSehExceptionsInMethodIfSupported(object, method, location);
 #endif  // GTEST_HAS_EXCEPTIONS
   } else {
     return (object->*method)();
   }
 }
 
 }  // namespace internal
 
 // Runs the test and updates the test result.
 void Test::Run() {
   if (!HasSameFixtureClass()) return;
 
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   impl->os_stack_trace_getter()->UponLeavingGTest();
   internal::HandleExceptionsInMethodIfSupported(this, &Test::SetUp, "SetUp()");
   // We will run the test only if SetUp() was successful and didn't call
   // GTEST_SKIP().
   if (!HasFatalFailure() && !IsSkipped()) {
     impl->os_stack_trace_getter()->UponLeavingGTest();
     internal::HandleExceptionsInMethodIfSupported(
         this, &Test::TestBody, "the test body");
   }
 
   // However, we want to clean up as much as possible.  Hence we will
   // always call TearDown(), even if SetUp() or the test body has
   // failed.
   impl->os_stack_trace_getter()->UponLeavingGTest();
   internal::HandleExceptionsInMethodIfSupported(
       this, &Test::TearDown, "TearDown()");
 }
 
 // Returns true if and only if the current test has a fatal failure.
 bool Test::HasFatalFailure() {
   return internal::GetUnitTestImpl()->current_test_result()->HasFatalFailure();
 }
 
 // Returns true if and only if the current test has a non-fatal failure.
 bool Test::HasNonfatalFailure() {
   return internal::GetUnitTestImpl()->current_test_result()->
       HasNonfatalFailure();
 }
 
 // Returns true if and only if the current test was skipped.
 bool Test::IsSkipped() {
   return internal::GetUnitTestImpl()->current_test_result()->Skipped();
 }
 
 // class TestInfo
 
 // Constructs a TestInfo object. It assumes ownership of the test factory
 // object.
 TestInfo::TestInfo(const std::string& a_test_suite_name,
                    const std::string& a_name, const char* a_type_param,
                    const char* a_value_param,
                    internal::CodeLocation a_code_location,
                    internal::TypeId fixture_class_id,
                    internal::TestFactoryBase* factory)
     : test_suite_name_(a_test_suite_name),
       name_(a_name),
       type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
       value_param_(a_value_param ? new std::string(a_value_param) : nullptr),
       location_(a_code_location),
       fixture_class_id_(fixture_class_id),
       should_run_(false),
       is_disabled_(false),
       matches_filter_(false),
       factory_(factory),
       result_() {}
 
 // Destructs a TestInfo object.
 TestInfo::~TestInfo() { delete factory_; }
 
 namespace internal {
 
 // Creates a new TestInfo object and registers it with Google Test;
 // returns the created object.
 //
 // Arguments:
 //
 //   test_suite_name:   name of the test suite
 //   name:             name of the test
 //   type_param:       the name of the test's type parameter, or NULL if
 //                     this is not a typed or a type-parameterized test.
 //   value_param:      text representation of the test's value parameter,
 //                     or NULL if this is not a value-parameterized test.
 //   code_location:    code location where the test is defined
 //   fixture_class_id: ID of the test fixture class
 //   set_up_tc:        pointer to the function that sets up the test suite
 //   tear_down_tc:     pointer to the function that tears down the test suite
 //   factory:          pointer to the factory that creates a test object.
 //                     The newly created TestInfo instance will assume
 //                     ownership of the factory object.
 TestInfo* MakeAndRegisterTestInfo(
     const char* test_suite_name, const char* name, const char* type_param,
     const char* value_param, CodeLocation code_location,
     TypeId fixture_class_id, SetUpTestSuiteFunc set_up_tc,
     TearDownTestSuiteFunc tear_down_tc, TestFactoryBase* factory) {
   TestInfo* const test_info =
       new TestInfo(test_suite_name, name, type_param, value_param,
                    code_location, fixture_class_id, factory);
   GetUnitTestImpl()->AddTestInfo(set_up_tc, tear_down_tc, test_info);
   return test_info;
 }
 
 void ReportInvalidTestSuiteType(const char* test_suite_name,
                                 CodeLocation code_location) {
   Message errors;
   errors
       << "Attempted redefinition of test suite " << test_suite_name << ".\n"
       << "All tests in the same test suite must use the same test fixture\n"
       << "class.  However, in test suite " << test_suite_name << ", you tried\n"
       << "to define a test using a fixture class different from the one\n"
       << "used earlier. This can happen if the two fixture classes are\n"
       << "from different namespaces and have the same name. You should\n"
       << "probably rename one of the classes to put the tests into different\n"
       << "test suites.";
 
   GTEST_LOG_(ERROR) << FormatFileLocation(code_location.file.c_str(),
                                           code_location.line)
                     << " " << errors.GetString();
 }
 }  // namespace internal
 
 namespace {
 
 // A predicate that checks the test name of a TestInfo against a known
 // value.
 //
 // This is used for implementation of the TestSuite class only.  We put
 // it in the anonymous namespace to prevent polluting the outer
 // namespace.
 //
 // TestNameIs is copyable.
 class TestNameIs {
  public:
   // Constructor.
   //
   // TestNameIs has NO default constructor.
   explicit TestNameIs(const char* name)
       : name_(name) {}
 
   // Returns true if and only if the test name of test_info matches name_.
   bool operator()(const TestInfo * test_info) const {
     return test_info && test_info->name() == name_;
   }
 
  private:
   std::string name_;
 };
 
 }  // namespace
 
 namespace internal {
 
 // This method expands all parameterized tests registered with macros TEST_P
 // and INSTANTIATE_TEST_SUITE_P into regular tests and registers those.
 // This will be done just once during the program runtime.
 void UnitTestImpl::RegisterParameterizedTests() {
   if (!parameterized_tests_registered_) {
     parameterized_test_registry_.RegisterTests();
     type_parameterized_test_registry_.CheckForInstantiations();
     parameterized_tests_registered_ = true;
   }
 }
 
 }  // namespace internal
 
 // Creates the test object, runs it, records its result, and then
 // deletes it.
 void TestInfo::Run() {
   if (!should_run_) return;
 
   // Tells UnitTest where to store test result.
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   impl->set_current_test_info(this);
 
   TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
 
   // Notifies the unit test event listeners that a test is about to start.
   repeater->OnTestStart(*this);
 
   const TimeInMillis start = internal::GetTimeInMillis();
 
   impl->os_stack_trace_getter()->UponLeavingGTest();
 
   // Creates the test object.
   Test* const test = internal::HandleExceptionsInMethodIfSupported(
       factory_, &internal::TestFactoryBase::CreateTest,
       "the test fixture's constructor");
 
   // Runs the test if the constructor didn't generate a fatal failure or invoke
   // GTEST_SKIP().
   // Note that the object will not be null
   if (!Test::HasFatalFailure() && !Test::IsSkipped()) {
     // This doesn't throw as all user code that can throw are wrapped into
     // exception handling code.
     test->Run();
   }
 
   if (test != nullptr) {
     // Deletes the test object.
     impl->os_stack_trace_getter()->UponLeavingGTest();
     internal::HandleExceptionsInMethodIfSupported(
         test, &Test::DeleteSelf_, "the test fixture's destructor");
   }
 
   result_.set_start_timestamp(start);
   result_.set_elapsed_time(internal::GetTimeInMillis() - start);
 
   // Notifies the unit test event listener that a test has just finished.
   repeater->OnTestEnd(*this);
 
   // Tells UnitTest to stop associating assertion results to this
   // test.
   impl->set_current_test_info(nullptr);
 }
 
 // class TestSuite
 
 // Gets the number of successful tests in this test suite.
 int TestSuite::successful_test_count() const {
   return CountIf(test_info_list_, TestPassed);
 }
 
 // Gets the number of successful tests in this test suite.
 int TestSuite::skipped_test_count() const {
   return CountIf(test_info_list_, TestSkipped);
 }
 
 // Gets the number of failed tests in this test suite.
 int TestSuite::failed_test_count() const {
   return CountIf(test_info_list_, TestFailed);
 }
 
 // Gets the number of disabled tests that will be reported in the XML report.
 int TestSuite::reportable_disabled_test_count() const {
   return CountIf(test_info_list_, TestReportableDisabled);
 }
 
 // Gets the number of disabled tests in this test suite.
 int TestSuite::disabled_test_count() const {
   return CountIf(test_info_list_, TestDisabled);
 }
 
 // Gets the number of tests to be printed in the XML report.
 int TestSuite::reportable_test_count() const {
   return CountIf(test_info_list_, TestReportable);
 }
 
 // Get the number of tests in this test suite that should run.
 int TestSuite::test_to_run_count() const {
   return CountIf(test_info_list_, ShouldRunTest);
 }
 
 // Gets the number of all tests.
 int TestSuite::total_test_count() const {
   return static_cast<int>(test_info_list_.size());
 }
 
 // Creates a TestSuite with the given name.
 //
 // Arguments:
 //
 //   name:         name of the test suite
 //   a_type_param: the name of the test suite's type parameter, or NULL if
 //                 this is not a typed or a type-parameterized test suite.
 //   set_up_tc:    pointer to the function that sets up the test suite
 //   tear_down_tc: pointer to the function that tears down the test suite
 TestSuite::TestSuite(const char* a_name, const char* a_type_param,
                      internal::SetUpTestSuiteFunc set_up_tc,
                      internal::TearDownTestSuiteFunc tear_down_tc)
     : name_(a_name),
       type_param_(a_type_param ? new std::string(a_type_param) : nullptr),
       set_up_tc_(set_up_tc),
       tear_down_tc_(tear_down_tc),
       should_run_(false),
       start_timestamp_(0),
       elapsed_time_(0) {}
 
 // Destructor of TestSuite.
 TestSuite::~TestSuite() {
   // Deletes every Test in the collection.
   ForEach(test_info_list_, internal::Delete<TestInfo>);
 }
 
 // Returns the i-th test among all the tests. i can range from 0 to
 // total_test_count() - 1. If i is not in that range, returns NULL.
 const TestInfo* TestSuite::GetTestInfo(int i) const {
   const int index = GetElementOr(test_indices_, i, -1);
   return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
 }
 
 // Returns the i-th test among all the tests. i can range from 0 to
 // total_test_count() - 1. If i is not in that range, returns NULL.
 TestInfo* TestSuite::GetMutableTestInfo(int i) {
   const int index = GetElementOr(test_indices_, i, -1);
   return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
 }
 
 // Adds a test to this test suite.  Will delete the test upon
 // destruction of the TestSuite object.
 void TestSuite::AddTestInfo(TestInfo* test_info) {
   test_info_list_.push_back(test_info);
   test_indices_.push_back(static_cast<int>(test_indices_.size()));
 }
 
 // Runs every test in this TestSuite.
 void TestSuite::Run() {
   if (!should_run_) return;
 
   internal::UnitTestImpl* const impl = internal::GetUnitTestImpl();
   impl->set_current_test_suite(this);
 
   TestEventListener* repeater = UnitTest::GetInstance()->listeners().repeater();
 
   // Call both legacy and the new API
   repeater->OnTestSuiteStart(*this);
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI
   repeater->OnTestCaseStart(*this);
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI
 
   impl->os_stack_trace_getter()->UponLeavingGTest();
   internal::HandleExceptionsInMethodIfSupported(
       this, &TestSuite::RunSetUpTestSuite, "SetUpTestSuite()");
 
   start_timestamp_ = internal::GetTimeInMillis();
   for (int i = 0; i < total_test_count(); i++) {
     GetMutableTestInfo(i)->Run();
   }
   elapsed_time_ = internal::GetTimeInMillis() - start_timestamp_;
 
   impl->os_stack_trace_getter()->UponLeavingGTest();
   internal::HandleExceptionsInMethodIfSupported(
       this, &TestSuite::RunTearDownTestSuite, "TearDownTestSuite()");
 
   // Call both legacy and the new API
   repeater->OnTestSuiteEnd(*this);
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI
   repeater->OnTestCaseEnd(*this);
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI
 
   impl->set_current_test_suite(nullptr);
 }
 
 // Clears the results of all tests in this test suite.
 void TestSuite::ClearResult() {
   ad_hoc_test_result_.Clear();
   ForEach(test_info_list_, TestInfo::ClearTestResult);
 }
 
 // Shuffles the tests in this test suite.
 void TestSuite::ShuffleTests(internal::Random* random) {
   Shuffle(random, &test_indices_);
 }
 
 // Restores the test order to before the first shuffle.
 void TestSuite::UnshuffleTests() {
   for (size_t i = 0; i < test_indices_.size(); i++) {
     test_indices_[i] = static_cast<int>(i);
   }
 }
 
 // Formats a countable noun.  Depending on its quantity, either the
 // singular form or the plural form is used. e.g.
 //
 // FormatCountableNoun(1, "formula", "formuli") returns "1 formula".
 // FormatCountableNoun(5, "book", "books") returns "5 books".
 static std::string FormatCountableNoun(int count,
                                        const char * singular_form,
                                        const char * plural_form) {
   return internal::StreamableToString(count) + " " +
       (count == 1 ? singular_form : plural_form);
 }
 
 // Formats the count of tests.
 static std::string FormatTestCount(int test_count) {
   return FormatCountableNoun(test_count, "test", "tests");
 }
 
 // Formats the count of test suites.
 static std::string FormatTestSuiteCount(int test_suite_count) {
   return FormatCountableNoun(test_suite_count, "test suite", "test suites");
 }
 
 // Converts a TestPartResult::Type enum to human-friendly string
 // representation.  Both kNonFatalFailure and kFatalFailure are translated
 // to "Failure", as the user usually doesn't care about the difference
 // between the two when viewing the test result.
 static const char * TestPartResultTypeToString(TestPartResult::Type type) {
   switch (type) {
     case TestPartResult::kSkip:
       return "Skipped";
     case TestPartResult::kSuccess:
       return "Success";
 
     case TestPartResult::kNonFatalFailure:
     case TestPartResult::kFatalFailure:
 #ifdef _MSC_VER
       return "error: ";
 #else
       return "Failure\n";
 #endif
     default:
       return "Unknown result type";
   }
 }
 
 namespace internal {
 namespace {
 enum class GTestColor { kDefault, kRed, kGreen, kYellow };
 }  // namespace
 
 // Prints a TestPartResult to an std::string.
 static std::string PrintTestPartResultToString(
     const TestPartResult& test_part_result) {
   return (Message()
           << internal::FormatFileLocation(test_part_result.file_name(),
                                           test_part_result.line_number())
           << " " << TestPartResultTypeToString(test_part_result.type())
           << test_part_result.message()).GetString();
 }
 
 // Prints a TestPartResult.
 static void PrintTestPartResult(const TestPartResult& test_part_result) {
   const std::string& result =
       PrintTestPartResultToString(test_part_result);
   printf("%s\n", result.c_str());
   fflush(stdout);
   // If the test program runs in Visual Studio or a debugger, the
   // following statements add the test part result message to the Output
   // window such that the user can double-click on it to jump to the
   // corresponding source code location; otherwise they do nothing.
 #if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
   // We don't call OutputDebugString*() on Windows Mobile, as printing
   // to stdout is done by OutputDebugString() there already - we don't
   // want the same message printed twice.
   ::OutputDebugStringA(result.c_str());
   ::OutputDebugStringA("\n");
 #endif
 }
 
 // class PrettyUnitTestResultPrinter
 #if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
     !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
 
 // Returns the character attribute for the given color.
 static WORD GetColorAttribute(GTestColor color) {
   switch (color) {
     case GTestColor::kRed:
       return FOREGROUND_RED;
     case GTestColor::kGreen:
       return FOREGROUND_GREEN;
     case GTestColor::kYellow:
       return FOREGROUND_RED | FOREGROUND_GREEN;
     default:           return 0;
   }
 }
 
 static int GetBitOffset(WORD color_mask) {
   if (color_mask == 0) return 0;
 
   int bitOffset = 0;
   while ((color_mask & 1) == 0) {
     color_mask >>= 1;
     ++bitOffset;
   }
   return bitOffset;
 }
 
 static WORD GetNewColor(GTestColor color, WORD old_color_attrs) {
   // Let's reuse the BG
   static const WORD background_mask = BACKGROUND_BLUE | BACKGROUND_GREEN |
                                       BACKGROUND_RED | BACKGROUND_INTENSITY;
   static const WORD foreground_mask = FOREGROUND_BLUE | FOREGROUND_GREEN |
                                       FOREGROUND_RED | FOREGROUND_INTENSITY;
   const WORD existing_bg = old_color_attrs & background_mask;
 
   WORD new_color =
       GetColorAttribute(color) | existing_bg | FOREGROUND_INTENSITY;
   static const int bg_bitOffset = GetBitOffset(background_mask);
   static const int fg_bitOffset = GetBitOffset(foreground_mask);
 
   if (((new_color & background_mask) >> bg_bitOffset) ==
       ((new_color & foreground_mask) >> fg_bitOffset)) {
     new_color ^= FOREGROUND_INTENSITY;  // invert intensity
   }
   return new_color;
 }
 
 #else
 
 // Returns the ANSI color code for the given color. GTestColor::kDefault is
 // an invalid input.
 static const char* GetAnsiColorCode(GTestColor color) {
   switch (color) {
     case GTestColor::kRed:
       return "1";
     case GTestColor::kGreen:
       return "2";
     case GTestColor::kYellow:
       return "3";
     default:
       return nullptr;
   }
 }
 
 #endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
 
 // Returns true if and only if Google Test should use colors in the output.
 bool ShouldUseColor(bool stdout_is_tty) {
   const char* const gtest_color = GTEST_FLAG(color).c_str();
 
   if (String::CaseInsensitiveCStringEquals(gtest_color, "auto")) {
 #if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MINGW
     // On Windows the TERM variable is usually not set, but the
     // console there does support colors.
     return stdout_is_tty;
 #else
     // On non-Windows platforms, we rely on the TERM variable.
     const char* const term = posix::GetEnv("TERM");
     const bool term_supports_color =
         String::CStringEquals(term, "xterm") ||
         String::CStringEquals(term, "xterm-color") ||
         String::CStringEquals(term, "xterm-256color") ||
         String::CStringEquals(term, "screen") ||
         String::CStringEquals(term, "screen-256color") ||
         String::CStringEquals(term, "tmux") ||
         String::CStringEquals(term, "tmux-256color") ||
         String::CStringEquals(term, "rxvt-unicode") ||
         String::CStringEquals(term, "rxvt-unicode-256color") ||
         String::CStringEquals(term, "linux") ||
         String::CStringEquals(term, "cygwin");
     return stdout_is_tty && term_supports_color;
 #endif  // GTEST_OS_WINDOWS
   }
 
   return String::CaseInsensitiveCStringEquals(gtest_color, "yes") ||
       String::CaseInsensitiveCStringEquals(gtest_color, "true") ||
       String::CaseInsensitiveCStringEquals(gtest_color, "t") ||
       String::CStringEquals(gtest_color, "1");
   // We take "yes", "true", "t", and "1" as meaning "yes".  If the
   // value is neither one of these nor "auto", we treat it as "no" to
   // be conservative.
 }
 
 // Helpers for printing colored strings to stdout. Note that on Windows, we
 // cannot simply emit special characters and have the terminal change colors.
 // This routine must actually emit the characters rather than return a string
 // that would be colored when printed, as can be done on Linux.
 
 void ColoredPrintf(GTestColor color, const char* fmt, ...) {
   va_list args;
   va_start(args, fmt);
 
 #if GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS || GTEST_OS_IOS || \
     GTEST_OS_WINDOWS_PHONE || GTEST_OS_WINDOWS_RT || defined(ESP_PLATFORM)
   const bool use_color = AlwaysFalse();
 #else
   static const bool in_color_mode =
       ShouldUseColor(posix::IsATTY(posix::FileNo(stdout)) != 0);
   const bool use_color = in_color_mode && (color != GTestColor::kDefault);
 #endif  // GTEST_OS_WINDOWS_MOBILE || GTEST_OS_ZOS
 
   if (!use_color) {
     vprintf(fmt, args);
     va_end(args);
     return;
   }
 
 #if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE && \
     !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT && !GTEST_OS_WINDOWS_MINGW
   const HANDLE stdout_handle = GetStdHandle(STD_OUTPUT_HANDLE);
 
   // Gets the current text color.
   CONSOLE_SCREEN_BUFFER_INFO buffer_info;
   GetConsoleScreenBufferInfo(stdout_handle, &buffer_info);
   const WORD old_color_attrs = buffer_info.wAttributes;
   const WORD new_color = GetNewColor(color, old_color_attrs);
 
   // We need to flush the stream buffers into the console before each
   // SetConsoleTextAttribute call lest it affect the text that is already
   // printed but has not yet reached the console.
   fflush(stdout);
   SetConsoleTextAttribute(stdout_handle, new_color);
 
   vprintf(fmt, args);
 
   fflush(stdout);
   // Restores the text color.
   SetConsoleTextAttribute(stdout_handle, old_color_attrs);
 #else
   printf("\033[0;3%sm", GetAnsiColorCode(color));
   vprintf(fmt, args);
   printf("\033[m");  // Resets the terminal to default.
 #endif  // GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_MOBILE
   va_end(args);
 }
 
 // Text printed in Google Test's text output and --gtest_list_tests
 // output to label the type parameter and value parameter for a test.
 static const char kTypeParamLabel[] = "TypeParam";
 static const char kValueParamLabel[] = "GetParam()";
 
 static void PrintFullTestCommentIfPresent(const TestInfo& test_info) {
   const char* const type_param = test_info.type_param();
   const char* const value_param = test_info.value_param();
 
   if (type_param != nullptr || value_param != nullptr) {
     printf(", where ");
     if (type_param != nullptr) {
       printf("%s = %s", kTypeParamLabel, type_param);
       if (value_param != nullptr) printf(" and ");
     }
     if (value_param != nullptr) {
       printf("%s = %s", kValueParamLabel, value_param);
     }
   }
 }
 
 // This class implements the TestEventListener interface.
 //
 // Class PrettyUnitTestResultPrinter is copyable.
 class PrettyUnitTestResultPrinter : public TestEventListener {
  public:
   PrettyUnitTestResultPrinter() {}
   static void PrintTestName(const char* test_suite, const char* test) {
     printf("%s.%s", test_suite, test);
   }
 
   // The following methods override what's in the TestEventListener class.
   void OnTestProgramStart(const UnitTest& /*unit_test*/) override {}
   void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
   void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
   void OnEnvironmentsSetUpEnd(const UnitTest& /*unit_test*/) override {}
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseStart(const TestCase& test_case) override;
 #else
   void OnTestSuiteStart(const TestSuite& test_suite) override;
 #endif  // OnTestCaseStart
 
   void OnTestStart(const TestInfo& test_info) override;
 
   void OnTestPartResult(const TestPartResult& result) override;
   void OnTestEnd(const TestInfo& test_info) override;
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseEnd(const TestCase& test_case) override;
 #else
   void OnTestSuiteEnd(const TestSuite& test_suite) override;
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
   void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
   void OnEnvironmentsTearDownEnd(const UnitTest& /*unit_test*/) override {}
   void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
   void OnTestProgramEnd(const UnitTest& /*unit_test*/) override {}
 
  private:
   static void PrintFailedTests(const UnitTest& unit_test);
   static void PrintFailedTestSuites(const UnitTest& unit_test);
   static void PrintSkippedTests(const UnitTest& unit_test);
 };
 
   // Fired before each iteration of tests starts.
 void PrettyUnitTestResultPrinter::OnTestIterationStart(
     const UnitTest& unit_test, int iteration) {
   if (GTEST_FLAG(repeat) != 1)
     printf("\nRepeating all tests (iteration %d) . . .\n\n", iteration + 1);
 
   const char* const filter = GTEST_FLAG(filter).c_str();
 
   // Prints the filter if it's not *.  This reminds the user that some
   // tests may be skipped.
   if (!String::CStringEquals(filter, kUniversalFilter)) {
     ColoredPrintf(GTestColor::kYellow, "Note: %s filter = %s\n", GTEST_NAME_,
                   filter);
   }
 
   if (internal::ShouldShard(kTestTotalShards, kTestShardIndex, false)) {
     const int32_t shard_index = Int32FromEnvOrDie(kTestShardIndex, -1);
     ColoredPrintf(GTestColor::kYellow, "Note: This is test shard %d of %s.\n",
                   static_cast<int>(shard_index) + 1,
                   internal::posix::GetEnv(kTestTotalShards));
   }
 
   if (GTEST_FLAG(shuffle)) {
     ColoredPrintf(GTestColor::kYellow,
                   "Note: Randomizing tests' orders with a seed of %d .\n",
                   unit_test.random_seed());
   }
 
   ColoredPrintf(GTestColor::kGreen, "[==========] ");
   printf("Running %s from %s.\n",
          FormatTestCount(unit_test.test_to_run_count()).c_str(),
          FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
   fflush(stdout);
 }
 
 void PrettyUnitTestResultPrinter::OnEnvironmentsSetUpStart(
     const UnitTest& /*unit_test*/) {
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("Global test environment set-up.\n");
   fflush(stdout);
 }
 
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 void PrettyUnitTestResultPrinter::OnTestCaseStart(const TestCase& test_case) {
   const std::string counts =
       FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("%s from %s", counts.c_str(), test_case.name());
   if (test_case.type_param() == nullptr) {
     printf("\n");
   } else {
     printf(", where %s = %s\n", kTypeParamLabel, test_case.type_param());
   }
   fflush(stdout);
 }
 #else
 void PrettyUnitTestResultPrinter::OnTestSuiteStart(
     const TestSuite& test_suite) {
   const std::string counts =
       FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("%s from %s", counts.c_str(), test_suite.name());
   if (test_suite.type_param() == nullptr) {
     printf("\n");
   } else {
     printf(", where %s = %s\n", kTypeParamLabel, test_suite.type_param());
   }
   fflush(stdout);
 }
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
 void PrettyUnitTestResultPrinter::OnTestStart(const TestInfo& test_info) {
   ColoredPrintf(GTestColor::kGreen, "[ RUN      ] ");
   PrintTestName(test_info.test_suite_name(), test_info.name());
   printf("\n");
   fflush(stdout);
 }
 
 // Called after an assertion failure.
 void PrettyUnitTestResultPrinter::OnTestPartResult(
     const TestPartResult& result) {
   switch (result.type()) {
     // If the test part succeeded, we don't need to do anything.
     case TestPartResult::kSuccess:
       return;
     default:
       // Print failure message from the assertion
       // (e.g. expected this and got that).
       PrintTestPartResult(result);
       fflush(stdout);
   }
 }
 
 void PrettyUnitTestResultPrinter::OnTestEnd(const TestInfo& test_info) {
   if (test_info.result()->Passed()) {
     ColoredPrintf(GTestColor::kGreen, "[       OK ] ");
   } else if (test_info.result()->Skipped()) {
     ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
   } else {
     ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
   }
   PrintTestName(test_info.test_suite_name(), test_info.name());
   if (test_info.result()->Failed())
     PrintFullTestCommentIfPresent(test_info);
 
   if (GTEST_FLAG(print_time)) {
     printf(" (%s ms)\n", internal::StreamableToString(
            test_info.result()->elapsed_time()).c_str());
   } else {
     printf("\n");
   }
   fflush(stdout);
 }
 
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 void PrettyUnitTestResultPrinter::OnTestCaseEnd(const TestCase& test_case) {
   if (!GTEST_FLAG(print_time)) return;
 
   const std::string counts =
       FormatCountableNoun(test_case.test_to_run_count(), "test", "tests");
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_case.name(),
          internal::StreamableToString(test_case.elapsed_time()).c_str());
   fflush(stdout);
 }
 #else
 void PrettyUnitTestResultPrinter::OnTestSuiteEnd(const TestSuite& test_suite) {
   if (!GTEST_FLAG(print_time)) return;
 
   const std::string counts =
       FormatCountableNoun(test_suite.test_to_run_count(), "test", "tests");
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("%s from %s (%s ms total)\n\n", counts.c_str(), test_suite.name(),
          internal::StreamableToString(test_suite.elapsed_time()).c_str());
   fflush(stdout);
 }
 #endif  // GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
 void PrettyUnitTestResultPrinter::OnEnvironmentsTearDownStart(
     const UnitTest& /*unit_test*/) {
   ColoredPrintf(GTestColor::kGreen, "[----------] ");
   printf("Global test environment tear-down\n");
   fflush(stdout);
 }
 
 // Internal helper for printing the list of failed tests.
 void PrettyUnitTestResultPrinter::PrintFailedTests(const UnitTest& unit_test) {
   const int failed_test_count = unit_test.failed_test_count();
   ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
   printf("%s, listed below:\n", FormatTestCount(failed_test_count).c_str());
 
   for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
     const TestSuite& test_suite = *unit_test.GetTestSuite(i);
     if (!test_suite.should_run() || (test_suite.failed_test_count() == 0)) {
       continue;
     }
     for (int j = 0; j < test_suite.total_test_count(); ++j) {
       const TestInfo& test_info = *test_suite.GetTestInfo(j);
       if (!test_info.should_run() || !test_info.result()->Failed()) {
         continue;
       }
       ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
       printf("%s.%s", test_suite.name(), test_info.name());
       PrintFullTestCommentIfPresent(test_info);
       printf("\n");
     }
   }
   printf("\n%2d FAILED %s\n", failed_test_count,
          failed_test_count == 1 ? "TEST" : "TESTS");
 }
 
 // Internal helper for printing the list of test suite failures not covered by
 // PrintFailedTests.
 void PrettyUnitTestResultPrinter::PrintFailedTestSuites(
     const UnitTest& unit_test) {
   int suite_failure_count = 0;
   for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
     const TestSuite& test_suite = *unit_test.GetTestSuite(i);
     if (!test_suite.should_run()) {
       continue;
     }
     if (test_suite.ad_hoc_test_result().Failed()) {
       ColoredPrintf(GTestColor::kRed, "[  FAILED  ] ");
       printf("%s: SetUpTestSuite or TearDownTestSuite\n", test_suite.name());
       ++suite_failure_count;
     }
   }
   if (suite_failure_count > 0) {
     printf("\n%2d FAILED TEST %s\n", suite_failure_count,
            suite_failure_count == 1 ? "SUITE" : "SUITES");
   }
 }
 
 // Internal helper for printing the list of skipped tests.
 void PrettyUnitTestResultPrinter::PrintSkippedTests(const UnitTest& unit_test) {
   const int skipped_test_count = unit_test.skipped_test_count();
   if (skipped_test_count == 0) {
     return;
   }
 
   for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
     const TestSuite& test_suite = *unit_test.GetTestSuite(i);
     if (!test_suite.should_run() || (test_suite.skipped_test_count() == 0)) {
       continue;
     }
     for (int j = 0; j < test_suite.total_test_count(); ++j) {
       const TestInfo& test_info = *test_suite.GetTestInfo(j);
       if (!test_info.should_run() || !test_info.result()->Skipped()) {
         continue;
       }
       ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
       printf("%s.%s", test_suite.name(), test_info.name());
       printf("\n");
     }
   }
 }
 
 void PrettyUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
                                                      int /*iteration*/) {
   ColoredPrintf(GTestColor::kGreen, "[==========] ");
   printf("%s from %s ran.",
          FormatTestCount(unit_test.test_to_run_count()).c_str(),
          FormatTestSuiteCount(unit_test.test_suite_to_run_count()).c_str());
   if (GTEST_FLAG(print_time)) {
     printf(" (%s ms total)",
            internal::StreamableToString(unit_test.elapsed_time()).c_str());
   }
   printf("\n");
   ColoredPrintf(GTestColor::kGreen, "[  PASSED  ] ");
   printf("%s.\n", FormatTestCount(unit_test.successful_test_count()).c_str());
 
   const int skipped_test_count = unit_test.skipped_test_count();
   if (skipped_test_count > 0) {
     ColoredPrintf(GTestColor::kGreen, "[  SKIPPED ] ");
     printf("%s, listed below:\n", FormatTestCount(skipped_test_count).c_str());
     PrintSkippedTests(unit_test);
   }
 
   if (!unit_test.Passed()) {
     PrintFailedTests(unit_test);
     PrintFailedTestSuites(unit_test);
   }
 
   int num_disabled = unit_test.reportable_disabled_test_count();
   if (num_disabled && !GTEST_FLAG(also_run_disabled_tests)) {
     if (unit_test.Passed()) {
       printf("\n");  // Add a spacer if no FAILURE banner is displayed.
     }
     ColoredPrintf(GTestColor::kYellow, "  YOU HAVE %d DISABLED %s\n\n",
                   num_disabled, num_disabled == 1 ? "TEST" : "TESTS");
   }
   // Ensure that Google Test output is printed before, e.g., heapchecker output.
   fflush(stdout);
 }
 
 // End PrettyUnitTestResultPrinter
 
 // class TestEventRepeater
 //
 // This class forwards events to other event listeners.
 class TestEventRepeater : public TestEventListener {
  public:
   TestEventRepeater() : forwarding_enabled_(true) {}
   ~TestEventRepeater() override;
   void Append(TestEventListener *listener);
   TestEventListener* Release(TestEventListener* listener);
 
   // Controls whether events will be forwarded to listeners_. Set to false
   // in death test child processes.
   bool forwarding_enabled() const { return forwarding_enabled_; }
   void set_forwarding_enabled(bool enable) { forwarding_enabled_ = enable; }
 
   void OnTestProgramStart(const UnitTest& unit_test) override;
   void OnTestIterationStart(const UnitTest& unit_test, int iteration) override;
   void OnEnvironmentsSetUpStart(const UnitTest& unit_test) override;
   void OnEnvironmentsSetUpEnd(const UnitTest& unit_test) override;
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseStart(const TestSuite& parameter) override;
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestSuiteStart(const TestSuite& parameter) override;
   void OnTestStart(const TestInfo& test_info) override;
   void OnTestPartResult(const TestPartResult& result) override;
   void OnTestEnd(const TestInfo& test_info) override;
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestCaseEnd(const TestCase& parameter) override;
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
   void OnTestSuiteEnd(const TestSuite& parameter) override;
   void OnEnvironmentsTearDownStart(const UnitTest& unit_test) override;
   void OnEnvironmentsTearDownEnd(const UnitTest& unit_test) override;
   void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
   void OnTestProgramEnd(const UnitTest& unit_test) override;
 
  private:
   // Controls whether events will be forwarded to listeners_. Set to false
   // in death test child processes.
   bool forwarding_enabled_;
   // The list of listeners that receive events.
   std::vector<TestEventListener*> listeners_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(TestEventRepeater);
 };
 
 TestEventRepeater::~TestEventRepeater() {
   ForEach(listeners_, Delete<TestEventListener>);
 }
 
 void TestEventRepeater::Append(TestEventListener *listener) {
   listeners_.push_back(listener);
 }
 
 TestEventListener* TestEventRepeater::Release(TestEventListener *listener) {
   for (size_t i = 0; i < listeners_.size(); ++i) {
     if (listeners_[i] == listener) {
       listeners_.erase(listeners_.begin() + static_cast<int>(i));
       return listener;
     }
   }
 
   return nullptr;
 }
 
 // Since most methods are very similar, use macros to reduce boilerplate.
 // This defines a member that forwards the call to all listeners.
 #define GTEST_REPEATER_METHOD_(Name, Type) \
 void TestEventRepeater::Name(const Type& parameter) { \
   if (forwarding_enabled_) { \
     for (size_t i = 0; i < listeners_.size(); i++) { \
       listeners_[i]->Name(parameter); \
     } \
   } \
 }
 // This defines a member that forwards the call to all listeners in reverse
 // order.
 #define GTEST_REVERSE_REPEATER_METHOD_(Name, Type)      \
   void TestEventRepeater::Name(const Type& parameter) { \
     if (forwarding_enabled_) {                          \
       for (size_t i = listeners_.size(); i != 0; i--) { \
         listeners_[i - 1]->Name(parameter);             \
       }                                                 \
     }                                                   \
   }
 
 GTEST_REPEATER_METHOD_(OnTestProgramStart, UnitTest)
 GTEST_REPEATER_METHOD_(OnEnvironmentsSetUpStart, UnitTest)
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 GTEST_REPEATER_METHOD_(OnTestCaseStart, TestSuite)
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 GTEST_REPEATER_METHOD_(OnTestSuiteStart, TestSuite)
 GTEST_REPEATER_METHOD_(OnTestStart, TestInfo)
 GTEST_REPEATER_METHOD_(OnTestPartResult, TestPartResult)
 GTEST_REPEATER_METHOD_(OnEnvironmentsTearDownStart, UnitTest)
 GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsSetUpEnd, UnitTest)
 GTEST_REVERSE_REPEATER_METHOD_(OnEnvironmentsTearDownEnd, UnitTest)
 GTEST_REVERSE_REPEATER_METHOD_(OnTestEnd, TestInfo)
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 GTEST_REVERSE_REPEATER_METHOD_(OnTestCaseEnd, TestSuite)
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 GTEST_REVERSE_REPEATER_METHOD_(OnTestSuiteEnd, TestSuite)
 GTEST_REVERSE_REPEATER_METHOD_(OnTestProgramEnd, UnitTest)
 
 #undef GTEST_REPEATER_METHOD_
 #undef GTEST_REVERSE_REPEATER_METHOD_
 
 void TestEventRepeater::OnTestIterationStart(const UnitTest& unit_test,
                                              int iteration) {
   if (forwarding_enabled_) {
     for (size_t i = 0; i < listeners_.size(); i++) {
       listeners_[i]->OnTestIterationStart(unit_test, iteration);
     }
   }
 }
 
 void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
                                            int iteration) {
   if (forwarding_enabled_) {
     for (size_t i = listeners_.size(); i > 0; i--) {
       listeners_[i - 1]->OnTestIterationEnd(unit_test, iteration);
     }
   }
 }
 
 // End TestEventRepeater
 
 // This class generates an XML output file.
 class XmlUnitTestResultPrinter : public EmptyTestEventListener {
  public:
   explicit XmlUnitTestResultPrinter(const char* output_file);
 
   void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
   void ListTestsMatchingFilter(const std::vector<TestSuite*>& test_suites);
 
   // Prints an XML summary of all unit tests.
   static void PrintXmlTestsList(std::ostream* stream,
                                 const std::vector<TestSuite*>& test_suites);
 
  private:
   // Is c a whitespace character that is normalized to a space character
   // when it appears in an XML attribute value?
   static bool IsNormalizableWhitespace(char c) {
     return c == 0x9 || c == 0xA || c == 0xD;
   }
 
   // May c appear in a well-formed XML document?
   static bool IsValidXmlCharacter(char c) {
     return IsNormalizableWhitespace(c) || c >= 0x20;
   }
 
   // Returns an XML-escaped copy of the input string str.  If
   // is_attribute is true, the text is meant to appear as an attribute
   // value, and normalizable whitespace is preserved by replacing it
   // with character references.
   static std::string EscapeXml(const std::string& str, bool is_attribute);
 
   // Returns the given string with all characters invalid in XML removed.
   static std::string RemoveInvalidXmlCharacters(const std::string& str);
 
   // Convenience wrapper around EscapeXml when str is an attribute value.
   static std::string EscapeXmlAttribute(const std::string& str) {
     return EscapeXml(str, true);
   }
 
   // Convenience wrapper around EscapeXml when str is not an attribute value.
   static std::string EscapeXmlText(const char* str) {
     return EscapeXml(str, false);
   }
 
   // Verifies that the given attribute belongs to the given element and
   // streams the attribute as XML.
   static void OutputXmlAttribute(std::ostream* stream,
                                  const std::string& element_name,
                                  const std::string& name,
                                  const std::string& value);
 
   // Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
   static void OutputXmlCDataSection(::std::ostream* stream, const char* data);
 
   // Streams an XML representation of a TestInfo object.
   static void OutputXmlTestInfo(::std::ostream* stream,
                                 const char* test_suite_name,
                                 const TestInfo& test_info);
 
   // Prints an XML representation of a TestSuite object
   static void PrintXmlTestSuite(::std::ostream* stream,
                                 const TestSuite& test_suite);
 
   // Prints an XML summary of unit_test to output stream out.
   static void PrintXmlUnitTest(::std::ostream* stream,
                                const UnitTest& unit_test);
 
   // Produces a string representing the test properties in a result as space
   // delimited XML attributes based on the property key="value" pairs.
   // When the std::string is not empty, it includes a space at the beginning,
   // to delimit this attribute from prior attributes.
   static std::string TestPropertiesAsXmlAttributes(const TestResult& result);
 
   // Streams an XML representation of the test properties of a TestResult
   // object.
   static void OutputXmlTestProperties(std::ostream* stream,
                                       const TestResult& result);
 
   // The output file.
   const std::string output_file_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(XmlUnitTestResultPrinter);
 };
 
 // Creates a new XmlUnitTestResultPrinter.
 XmlUnitTestResultPrinter::XmlUnitTestResultPrinter(const char* output_file)
     : output_file_(output_file) {
   if (output_file_.empty()) {
     GTEST_LOG_(FATAL) << "XML output file may not be null";
   }
 }
 
 // Called after the unit test ends.
 void XmlUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
                                                   int /*iteration*/) {
   FILE* xmlout = OpenFileForWriting(output_file_);
   std::stringstream stream;
   PrintXmlUnitTest(&stream, unit_test);
   fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
   fclose(xmlout);
 }
 
 void XmlUnitTestResultPrinter::ListTestsMatchingFilter(
     const std::vector<TestSuite*>& test_suites) {
   FILE* xmlout = OpenFileForWriting(output_file_);
   std::stringstream stream;
   PrintXmlTestsList(&stream, test_suites);
   fprintf(xmlout, "%s", StringStreamToString(&stream).c_str());
   fclose(xmlout);
 }
 
 // Returns an XML-escaped copy of the input string str.  If is_attribute
 // is true, the text is meant to appear as an attribute value, and
 // normalizable whitespace is preserved by replacing it with character
 // references.
 //
 // Invalid XML characters in str, if any, are stripped from the output.
 // It is expected that most, if not all, of the text processed by this
 // module will consist of ordinary English text.
 // If this module is ever modified to produce version 1.1 XML output,
 // most invalid characters can be retained using character references.
 std::string XmlUnitTestResultPrinter::EscapeXml(
     const std::string& str, bool is_attribute) {
   Message m;
 
   for (size_t i = 0; i < str.size(); ++i) {
     const char ch = str[i];
     switch (ch) {
       case '<':
         m << "&lt;";
         break;
       case '>':
         m << "&gt;";
         break;
       case '&':
         m << "&amp;";
         break;
       case '\'':
         if (is_attribute)
           m << "&apos;";
         else
           m << '\'';
         break;
       case '"':
         if (is_attribute)
           m << "&quot;";
         else
           m << '"';
         break;
       default:
         if (IsValidXmlCharacter(ch)) {
           if (is_attribute && IsNormalizableWhitespace(ch))
             m << "&#x" << String::FormatByte(static_cast<unsigned char>(ch))
               << ";";
           else
             m << ch;
         }
         break;
     }
   }
 
   return m.GetString();
 }
 
 // Returns the given string with all characters invalid in XML removed.
 // Currently invalid characters are dropped from the string. An
 // alternative is to replace them with certain characters such as . or ?.
 std::string XmlUnitTestResultPrinter::RemoveInvalidXmlCharacters(
     const std::string& str) {
   std::string output;
   output.reserve(str.size());
   for (std::string::const_iterator it = str.begin(); it != str.end(); ++it)
     if (IsValidXmlCharacter(*it))
       output.push_back(*it);
 
   return output;
 }
 
 // The following routines generate an XML representation of a UnitTest
 // object.
 // GOOGLETEST_CM0009 DO NOT DELETE
 //
 // This is how Google Test concepts map to the DTD:
 //
 // <testsuites name="AllTests">        <-- corresponds to a UnitTest object
 //   <testsuite name="testcase-name">  <-- corresponds to a TestSuite object
 //     <testcase name="test-name">     <-- corresponds to a TestInfo object
 //       <failure message="...">...</failure>
 //       <failure message="...">...</failure>
 //       <failure message="...">...</failure>
 //                                     <-- individual assertion failures
 //     </testcase>
 //   </testsuite>
 // </testsuites>
 
 // Formats the given time in milliseconds as seconds.
 std::string FormatTimeInMillisAsSeconds(TimeInMillis ms) {
   ::std::stringstream ss;
   ss << (static_cast<double>(ms) * 1e-3);
   return ss.str();
 }
 
 static bool PortableLocaltime(time_t seconds, struct tm* out) {
 #if defined(_MSC_VER)
   return localtime_s(out, &seconds) == 0;
 #elif defined(__MINGW32__) || defined(__MINGW64__)
   // MINGW <time.h> provides neither localtime_r nor localtime_s, but uses
   // Windows' localtime(), which has a thread-local tm buffer.
   struct tm* tm_ptr = localtime(&seconds);  // NOLINT
   if (tm_ptr == nullptr) return false;
   *out = *tm_ptr;
   return true;
 #else
   return localtime_r(&seconds, out) != nullptr;
 #endif
 }
 
 // Converts the given epoch time in milliseconds to a date string in the ISO
 // 8601 format, without the timezone information.
 std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms) {
   struct tm time_struct;
   if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
     return "";
   // YYYY-MM-DDThh:mm:ss
   return StreamableToString(time_struct.tm_year + 1900) + "-" +
       String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
       String::FormatIntWidth2(time_struct.tm_mday) + "T" +
       String::FormatIntWidth2(time_struct.tm_hour) + ":" +
       String::FormatIntWidth2(time_struct.tm_min) + ":" +
       String::FormatIntWidth2(time_struct.tm_sec);
 }
 
 // Streams an XML CDATA section, escaping invalid CDATA sequences as needed.
 void XmlUnitTestResultPrinter::OutputXmlCDataSection(::std::ostream* stream,
                                                      const char* data) {
   const char* segment = data;
   *stream << "<![CDATA[";
   for (;;) {
     const char* const next_segment = strstr(segment, "]]>");
     if (next_segment != nullptr) {
       stream->write(
           segment, static_cast<std::streamsize>(next_segment - segment));
       *stream << "]]>]]&gt;<![CDATA[";
       segment = next_segment + strlen("]]>");
     } else {
       *stream << segment;
       break;
     }
   }
   *stream << "]]>";
 }
 
 void XmlUnitTestResultPrinter::OutputXmlAttribute(
     std::ostream* stream,
     const std::string& element_name,
     const std::string& name,
     const std::string& value) {
   const std::vector<std::string>& allowed_names =
       GetReservedOutputAttributesForElement(element_name);
 
   GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
                    allowed_names.end())
       << "Attribute " << name << " is not allowed for element <" << element_name
       << ">.";
 
   *stream << " " << name << "=\"" << EscapeXmlAttribute(value) << "\"";
 }
 
 // Prints an XML representation of a TestInfo object.
 void XmlUnitTestResultPrinter::OutputXmlTestInfo(::std::ostream* stream,
                                                  const char* test_suite_name,
                                                  const TestInfo& test_info) {
   const TestResult& result = *test_info.result();
   const std::string kTestsuite = "testcase";
 
   if (test_info.is_in_another_shard()) {
     return;
   }
 
   *stream << "    <testcase";
   OutputXmlAttribute(stream, kTestsuite, "name", test_info.name());
 
   if (test_info.value_param() != nullptr) {
     OutputXmlAttribute(stream, kTestsuite, "value_param",
                        test_info.value_param());
   }
   if (test_info.type_param() != nullptr) {
     OutputXmlAttribute(stream, kTestsuite, "type_param",
                        test_info.type_param());
   }
   if (GTEST_FLAG(list_tests)) {
     OutputXmlAttribute(stream, kTestsuite, "file", test_info.file());
     OutputXmlAttribute(stream, kTestsuite, "line",
                        StreamableToString(test_info.line()));
     *stream << " />\n";
     return;
   }
 
   OutputXmlAttribute(stream, kTestsuite, "status",
                      test_info.should_run() ? "run" : "notrun");
   OutputXmlAttribute(stream, kTestsuite, "result",
                      test_info.should_run()
                          ? (result.Skipped() ? "skipped" : "completed")
                          : "suppressed");
   OutputXmlAttribute(stream, kTestsuite, "time",
                      FormatTimeInMillisAsSeconds(result.elapsed_time()));
   OutputXmlAttribute(
       stream, kTestsuite, "timestamp",
       FormatEpochTimeInMillisAsIso8601(result.start_timestamp()));
   OutputXmlAttribute(stream, kTestsuite, "classname", test_suite_name);
 
   int failures = 0;
   for (int i = 0; i < result.total_part_count(); ++i) {
     const TestPartResult& part = result.GetTestPartResult(i);
     if (part.failed()) {
       if (++failures == 1) {
         *stream << ">\n";
       }
       const std::string location =
           internal::FormatCompilerIndependentFileLocation(part.file_name(),
                                                           part.line_number());
       const std::string summary = location + "\n" + part.summary();
       *stream << "      <failure message=\""
               << EscapeXmlAttribute(summary.c_str())
               << "\" type=\"\">";
       const std::string detail = location + "\n" + part.message();
       OutputXmlCDataSection(stream, RemoveInvalidXmlCharacters(detail).c_str());
       *stream << "</failure>\n";
     }
   }
 
   if (failures == 0 && result.test_property_count() == 0) {
     *stream << " />\n";
   } else {
     if (failures == 0) {
       *stream << ">\n";
     }
     OutputXmlTestProperties(stream, result);
     *stream << "    </testcase>\n";
   }
 }
 
 // Prints an XML representation of a TestSuite object
 void XmlUnitTestResultPrinter::PrintXmlTestSuite(std::ostream* stream,
                                                  const TestSuite& test_suite) {
   const std::string kTestsuite = "testsuite";
   *stream << "  <" << kTestsuite;
   OutputXmlAttribute(stream, kTestsuite, "name", test_suite.name());
   OutputXmlAttribute(stream, kTestsuite, "tests",
                      StreamableToString(test_suite.reportable_test_count()));
   if (!GTEST_FLAG(list_tests)) {
     OutputXmlAttribute(stream, kTestsuite, "failures",
                        StreamableToString(test_suite.failed_test_count()));
     OutputXmlAttribute(
         stream, kTestsuite, "disabled",
         StreamableToString(test_suite.reportable_disabled_test_count()));
     OutputXmlAttribute(stream, kTestsuite, "errors", "0");
     OutputXmlAttribute(stream, kTestsuite, "time",
                        FormatTimeInMillisAsSeconds(test_suite.elapsed_time()));
     OutputXmlAttribute(
         stream, kTestsuite, "timestamp",
         FormatEpochTimeInMillisAsIso8601(test_suite.start_timestamp()));
     *stream << TestPropertiesAsXmlAttributes(test_suite.ad_hoc_test_result());
   }
   *stream << ">\n";
   for (int i = 0; i < test_suite.total_test_count(); ++i) {
     if (test_suite.GetTestInfo(i)->is_reportable())
       OutputXmlTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
   }
   *stream << "  </" << kTestsuite << ">\n";
 }
 
 // Prints an XML summary of unit_test to output stream out.
 void XmlUnitTestResultPrinter::PrintXmlUnitTest(std::ostream* stream,
                                                 const UnitTest& unit_test) {
   const std::string kTestsuites = "testsuites";
 
   *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
   *stream << "<" << kTestsuites;
 
   OutputXmlAttribute(stream, kTestsuites, "tests",
                      StreamableToString(unit_test.reportable_test_count()));
   OutputXmlAttribute(stream, kTestsuites, "failures",
                      StreamableToString(unit_test.failed_test_count()));
   OutputXmlAttribute(
       stream, kTestsuites, "disabled",
       StreamableToString(unit_test.reportable_disabled_test_count()));
   OutputXmlAttribute(stream, kTestsuites, "errors", "0");
   OutputXmlAttribute(stream, kTestsuites, "time",
                      FormatTimeInMillisAsSeconds(unit_test.elapsed_time()));
   OutputXmlAttribute(
       stream, kTestsuites, "timestamp",
       FormatEpochTimeInMillisAsIso8601(unit_test.start_timestamp()));
 
   if (GTEST_FLAG(shuffle)) {
     OutputXmlAttribute(stream, kTestsuites, "random_seed",
                        StreamableToString(unit_test.random_seed()));
   }
   *stream << TestPropertiesAsXmlAttributes(unit_test.ad_hoc_test_result());
 
   OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
   *stream << ">\n";
 
   for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
     if (unit_test.GetTestSuite(i)->reportable_test_count() > 0)
       PrintXmlTestSuite(stream, *unit_test.GetTestSuite(i));
   }
   *stream << "</" << kTestsuites << ">\n";
 }
 
 void XmlUnitTestResultPrinter::PrintXmlTestsList(
     std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
   const std::string kTestsuites = "testsuites";
 
   *stream << "<?xml version=\"1.0\" encoding=\"UTF-8\"?>\n";
   *stream << "<" << kTestsuites;
 
   int total_tests = 0;
   for (auto test_suite : test_suites) {
     total_tests += test_suite->total_test_count();
   }
   OutputXmlAttribute(stream, kTestsuites, "tests",
                      StreamableToString(total_tests));
   OutputXmlAttribute(stream, kTestsuites, "name", "AllTests");
   *stream << ">\n";
 
   for (auto test_suite : test_suites) {
     PrintXmlTestSuite(stream, *test_suite);
   }
   *stream << "</" << kTestsuites << ">\n";
 }
 
 // Produces a string representing the test properties in a result as space
 // delimited XML attributes based on the property key="value" pairs.
 std::string XmlUnitTestResultPrinter::TestPropertiesAsXmlAttributes(
     const TestResult& result) {
   Message attributes;
   for (int i = 0; i < result.test_property_count(); ++i) {
     const TestProperty& property = result.GetTestProperty(i);
     attributes << " " << property.key() << "="
         << "\"" << EscapeXmlAttribute(property.value()) << "\"";
   }
   return attributes.GetString();
 }
 
 void XmlUnitTestResultPrinter::OutputXmlTestProperties(
     std::ostream* stream, const TestResult& result) {
   const std::string kProperties = "properties";
   const std::string kProperty = "property";
 
   if (result.test_property_count() <= 0) {
     return;
   }
 
   *stream << "<" << kProperties << ">\n";
   for (int i = 0; i < result.test_property_count(); ++i) {
     const TestProperty& property = result.GetTestProperty(i);
     *stream << "<" << kProperty;
     *stream << " name=\"" << EscapeXmlAttribute(property.key()) << "\"";
     *stream << " value=\"" << EscapeXmlAttribute(property.value()) << "\"";
     *stream << "/>\n";
   }
   *stream << "</" << kProperties << ">\n";
 }
 
 // End XmlUnitTestResultPrinter
 
 // This class generates an JSON output file.
 class JsonUnitTestResultPrinter : public EmptyTestEventListener {
  public:
   explicit JsonUnitTestResultPrinter(const char* output_file);
 
   void OnTestIterationEnd(const UnitTest& unit_test, int iteration) override;
 
   // Prints an JSON summary of all unit tests.
   static void PrintJsonTestList(::std::ostream* stream,
                                 const std::vector<TestSuite*>& test_suites);
 
  private:
   // Returns an JSON-escaped copy of the input string str.
   static std::string EscapeJson(const std::string& str);
 
   //// Verifies that the given attribute belongs to the given element and
   //// streams the attribute as JSON.
   static void OutputJsonKey(std::ostream* stream,
                             const std::string& element_name,
                             const std::string& name,
                             const std::string& value,
                             const std::string& indent,
                             bool comma = true);
   static void OutputJsonKey(std::ostream* stream,
                             const std::string& element_name,
                             const std::string& name,
                             int value,
                             const std::string& indent,
                             bool comma = true);
 
   // Streams a JSON representation of a TestInfo object.
   static void OutputJsonTestInfo(::std::ostream* stream,
                                  const char* test_suite_name,
                                  const TestInfo& test_info);
 
   // Prints a JSON representation of a TestSuite object
   static void PrintJsonTestSuite(::std::ostream* stream,
                                  const TestSuite& test_suite);
 
   // Prints a JSON summary of unit_test to output stream out.
   static void PrintJsonUnitTest(::std::ostream* stream,
                                 const UnitTest& unit_test);
 
   // Produces a string representing the test properties in a result as
   // a JSON dictionary.
   static std::string TestPropertiesAsJson(const TestResult& result,
                                           const std::string& indent);
 
   // The output file.
   const std::string output_file_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(JsonUnitTestResultPrinter);
 };
 
 // Creates a new JsonUnitTestResultPrinter.
 JsonUnitTestResultPrinter::JsonUnitTestResultPrinter(const char* output_file)
     : output_file_(output_file) {
   if (output_file_.empty()) {
     GTEST_LOG_(FATAL) << "JSON output file may not be null";
   }
 }
 
 void JsonUnitTestResultPrinter::OnTestIterationEnd(const UnitTest& unit_test,
                                                   int /*iteration*/) {
   FILE* jsonout = OpenFileForWriting(output_file_);
   std::stringstream stream;
   PrintJsonUnitTest(&stream, unit_test);
   fprintf(jsonout, "%s", StringStreamToString(&stream).c_str());
   fclose(jsonout);
 }
 
 // Returns an JSON-escaped copy of the input string str.
 std::string JsonUnitTestResultPrinter::EscapeJson(const std::string& str) {
   Message m;
 
   for (size_t i = 0; i < str.size(); ++i) {
     const char ch = str[i];
     switch (ch) {
       case '\\':
       case '"':
       case '/':
         m << '\\' << ch;
         break;
       case '\b':
         m << "\\b";
         break;
       case '\t':
         m << "\\t";
         break;
       case '\n':
         m << "\\n";
         break;
       case '\f':
         m << "\\f";
         break;
       case '\r':
         m << "\\r";
         break;
       default:
         if (ch < ' ') {
           m << "\\u00" << String::FormatByte(static_cast<unsigned char>(ch));
         } else {
           m << ch;
         }
         break;
     }
   }
 
   return m.GetString();
 }
 
 // The following routines generate an JSON representation of a UnitTest
 // object.
 
 // Formats the given time in milliseconds as seconds.
 static std::string FormatTimeInMillisAsDuration(TimeInMillis ms) {
   ::std::stringstream ss;
   ss << (static_cast<double>(ms) * 1e-3) << "s";
   return ss.str();
 }
 
 // Converts the given epoch time in milliseconds to a date string in the
 // RFC3339 format, without the timezone information.
 static std::string FormatEpochTimeInMillisAsRFC3339(TimeInMillis ms) {
   struct tm time_struct;
   if (!PortableLocaltime(static_cast<time_t>(ms / 1000), &time_struct))
     return "";
   // YYYY-MM-DDThh:mm:ss
   return StreamableToString(time_struct.tm_year + 1900) + "-" +
       String::FormatIntWidth2(time_struct.tm_mon + 1) + "-" +
       String::FormatIntWidth2(time_struct.tm_mday) + "T" +
       String::FormatIntWidth2(time_struct.tm_hour) + ":" +
       String::FormatIntWidth2(time_struct.tm_min) + ":" +
       String::FormatIntWidth2(time_struct.tm_sec) + "Z";
 }
 
 static inline std::string Indent(size_t width) {
   return std::string(width, ' ');
 }
 
 void JsonUnitTestResultPrinter::OutputJsonKey(
     std::ostream* stream,
     const std::string& element_name,
     const std::string& name,
     const std::string& value,
     const std::string& indent,
     bool comma) {
   const std::vector<std::string>& allowed_names =
       GetReservedOutputAttributesForElement(element_name);
 
   GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
                    allowed_names.end())
       << "Key \"" << name << "\" is not allowed for value \"" << element_name
       << "\".";
 
   *stream << indent << "\"" << name << "\": \"" << EscapeJson(value) << "\"";
   if (comma)
     *stream << ",\n";
 }
 
 void JsonUnitTestResultPrinter::OutputJsonKey(
     std::ostream* stream,
     const std::string& element_name,
     const std::string& name,
     int value,
     const std::string& indent,
     bool comma) {
   const std::vector<std::string>& allowed_names =
       GetReservedOutputAttributesForElement(element_name);
 
   GTEST_CHECK_(std::find(allowed_names.begin(), allowed_names.end(), name) !=
                    allowed_names.end())
       << "Key \"" << name << "\" is not allowed for value \"" << element_name
       << "\".";
 
   *stream << indent << "\"" << name << "\": " << StreamableToString(value);
   if (comma)
     *stream << ",\n";
 }
 
 // Prints a JSON representation of a TestInfo object.
 void JsonUnitTestResultPrinter::OutputJsonTestInfo(::std::ostream* stream,
                                                    const char* test_suite_name,
                                                    const TestInfo& test_info) {
   const TestResult& result = *test_info.result();
   const std::string kTestsuite = "testcase";
   const std::string kIndent = Indent(10);
 
   *stream << Indent(8) << "{\n";
   OutputJsonKey(stream, kTestsuite, "name", test_info.name(), kIndent);
 
   if (test_info.value_param() != nullptr) {
     OutputJsonKey(stream, kTestsuite, "value_param", test_info.value_param(),
                   kIndent);
   }
   if (test_info.type_param() != nullptr) {
     OutputJsonKey(stream, kTestsuite, "type_param", test_info.type_param(),
                   kIndent);
   }
   if (GTEST_FLAG(list_tests)) {
     OutputJsonKey(stream, kTestsuite, "file", test_info.file(), kIndent);
     OutputJsonKey(stream, kTestsuite, "line", test_info.line(), kIndent, false);
     *stream << "\n" << Indent(8) << "}";
     return;
   }
 
   OutputJsonKey(stream, kTestsuite, "status",
                 test_info.should_run() ? "RUN" : "NOTRUN", kIndent);
   OutputJsonKey(stream, kTestsuite, "result",
                 test_info.should_run()
                     ? (result.Skipped() ? "SKIPPED" : "COMPLETED")
                     : "SUPPRESSED",
                 kIndent);
   OutputJsonKey(stream, kTestsuite, "timestamp",
                 FormatEpochTimeInMillisAsRFC3339(result.start_timestamp()),
                 kIndent);
   OutputJsonKey(stream, kTestsuite, "time",
                 FormatTimeInMillisAsDuration(result.elapsed_time()), kIndent);
   OutputJsonKey(stream, kTestsuite, "classname", test_suite_name, kIndent,
                 false);
   *stream << TestPropertiesAsJson(result, kIndent);
 
   int failures = 0;
   for (int i = 0; i < result.total_part_count(); ++i) {
     const TestPartResult& part = result.GetTestPartResult(i);
     if (part.failed()) {
       *stream << ",\n";
       if (++failures == 1) {
         *stream << kIndent << "\"" << "failures" << "\": [\n";
       }
       const std::string location =
           internal::FormatCompilerIndependentFileLocation(part.file_name(),
                                                           part.line_number());
       const std::string message = EscapeJson(location + "\n" + part.message());
       *stream << kIndent << "  {\n"
               << kIndent << "    \"failure\": \"" << message << "\",\n"
               << kIndent << "    \"type\": \"\"\n"
               << kIndent << "  }";
     }
   }
 
   if (failures > 0)
     *stream << "\n" << kIndent << "]";
   *stream << "\n" << Indent(8) << "}";
 }
 
 // Prints an JSON representation of a TestSuite object
 void JsonUnitTestResultPrinter::PrintJsonTestSuite(
     std::ostream* stream, const TestSuite& test_suite) {
   const std::string kTestsuite = "testsuite";
   const std::string kIndent = Indent(6);
 
   *stream << Indent(4) << "{\n";
   OutputJsonKey(stream, kTestsuite, "name", test_suite.name(), kIndent);
   OutputJsonKey(stream, kTestsuite, "tests", test_suite.reportable_test_count(),
                 kIndent);
   if (!GTEST_FLAG(list_tests)) {
     OutputJsonKey(stream, kTestsuite, "failures",
                   test_suite.failed_test_count(), kIndent);
     OutputJsonKey(stream, kTestsuite, "disabled",
                   test_suite.reportable_disabled_test_count(), kIndent);
     OutputJsonKey(stream, kTestsuite, "errors", 0, kIndent);
     OutputJsonKey(
         stream, kTestsuite, "timestamp",
         FormatEpochTimeInMillisAsRFC3339(test_suite.start_timestamp()),
         kIndent);
     OutputJsonKey(stream, kTestsuite, "time",
                   FormatTimeInMillisAsDuration(test_suite.elapsed_time()),
                   kIndent, false);
     *stream << TestPropertiesAsJson(test_suite.ad_hoc_test_result(), kIndent)
             << ",\n";
   }
 
   *stream << kIndent << "\"" << kTestsuite << "\": [\n";
 
   bool comma = false;
   for (int i = 0; i < test_suite.total_test_count(); ++i) {
     if (test_suite.GetTestInfo(i)->is_reportable()) {
       if (comma) {
         *stream << ",\n";
       } else {
         comma = true;
       }
       OutputJsonTestInfo(stream, test_suite.name(), *test_suite.GetTestInfo(i));
     }
   }
   *stream << "\n" << kIndent << "]\n" << Indent(4) << "}";
 }
 
 // Prints a JSON summary of unit_test to output stream out.
 void JsonUnitTestResultPrinter::PrintJsonUnitTest(std::ostream* stream,
                                                   const UnitTest& unit_test) {
   const std::string kTestsuites = "testsuites";
   const std::string kIndent = Indent(2);
   *stream << "{\n";
 
   OutputJsonKey(stream, kTestsuites, "tests", unit_test.reportable_test_count(),
                 kIndent);
   OutputJsonKey(stream, kTestsuites, "failures", unit_test.failed_test_count(),
                 kIndent);
   OutputJsonKey(stream, kTestsuites, "disabled",
                 unit_test.reportable_disabled_test_count(), kIndent);
   OutputJsonKey(stream, kTestsuites, "errors", 0, kIndent);
   if (GTEST_FLAG(shuffle)) {
     OutputJsonKey(stream, kTestsuites, "random_seed", unit_test.random_seed(),
                   kIndent);
   }
   OutputJsonKey(stream, kTestsuites, "timestamp",
                 FormatEpochTimeInMillisAsRFC3339(unit_test.start_timestamp()),
                 kIndent);
   OutputJsonKey(stream, kTestsuites, "time",
                 FormatTimeInMillisAsDuration(unit_test.elapsed_time()), kIndent,
                 false);
 
   *stream << TestPropertiesAsJson(unit_test.ad_hoc_test_result(), kIndent)
           << ",\n";
 
   OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
   *stream << kIndent << "\"" << kTestsuites << "\": [\n";
 
   bool comma = false;
   for (int i = 0; i < unit_test.total_test_suite_count(); ++i) {
     if (unit_test.GetTestSuite(i)->reportable_test_count() > 0) {
       if (comma) {
         *stream << ",\n";
       } else {
         comma = true;
       }
       PrintJsonTestSuite(stream, *unit_test.GetTestSuite(i));
     }
   }
 
   *stream << "\n" << kIndent << "]\n" << "}\n";
 }
 
 void JsonUnitTestResultPrinter::PrintJsonTestList(
     std::ostream* stream, const std::vector<TestSuite*>& test_suites) {
   const std::string kTestsuites = "testsuites";
   const std::string kIndent = Indent(2);
   *stream << "{\n";
   int total_tests = 0;
   for (auto test_suite : test_suites) {
     total_tests += test_suite->total_test_count();
   }
   OutputJsonKey(stream, kTestsuites, "tests", total_tests, kIndent);
 
   OutputJsonKey(stream, kTestsuites, "name", "AllTests", kIndent);
   *stream << kIndent << "\"" << kTestsuites << "\": [\n";
 
   for (size_t i = 0; i < test_suites.size(); ++i) {
     if (i != 0) {
       *stream << ",\n";
     }
     PrintJsonTestSuite(stream, *test_suites[i]);
   }
 
   *stream << "\n"
           << kIndent << "]\n"
           << "}\n";
 }
 // Produces a string representing the test properties in a result as
 // a JSON dictionary.
 std::string JsonUnitTestResultPrinter::TestPropertiesAsJson(
     const TestResult& result, const std::string& indent) {
   Message attributes;
   for (int i = 0; i < result.test_property_count(); ++i) {
     const TestProperty& property = result.GetTestProperty(i);
     attributes << ",\n" << indent << "\"" << property.key() << "\": "
                << "\"" << EscapeJson(property.value()) << "\"";
   }
   return attributes.GetString();
 }
 
 // End JsonUnitTestResultPrinter
 
 #if GTEST_CAN_STREAM_RESULTS_
 
 // Checks if str contains '=', '&', '%' or '\n' characters. If yes,
 // replaces them by "%xx" where xx is their hexadecimal value. For
 // example, replaces "=" with "%3D".  This algorithm is O(strlen(str))
 // in both time and space -- important as the input str may contain an
 // arbitrarily long test failure message and stack trace.
 std::string StreamingListener::UrlEncode(const char* str) {
   std::string result;
   result.reserve(strlen(str) + 1);
   for (char ch = *str; ch != '\0'; ch = *++str) {
     switch (ch) {
       case '%':
       case '=':
       case '&':
       case '\n':
         result.append("%" + String::FormatByte(static_cast<unsigned char>(ch)));
         break;
       default:
         result.push_back(ch);
         break;
     }
   }
   return result;
 }
 
 void StreamingListener::SocketWriter::MakeConnection() {
   GTEST_CHECK_(sockfd_ == -1)
       << "MakeConnection() can't be called when there is already a connection.";
 
   addrinfo hints;
   memset(&hints, 0, sizeof(hints));
   hints.ai_family = AF_UNSPEC;    // To allow both IPv4 and IPv6 addresses.
   hints.ai_socktype = SOCK_STREAM;
   addrinfo* servinfo = nullptr;
 
   // Use the getaddrinfo() to get a linked list of IP addresses for
   // the given host name.
   const int error_num = getaddrinfo(
       host_name_.c_str(), port_num_.c_str(), &hints, &servinfo);
   if (error_num != 0) {
     GTEST_LOG_(WARNING) << "stream_result_to: getaddrinfo() failed: "
                         << gai_strerror(error_num);
   }
 
   // Loop through all the results and connect to the first we can.
   for (addrinfo* cur_addr = servinfo; sockfd_ == -1 && cur_addr != nullptr;
        cur_addr = cur_addr->ai_next) {
     sockfd_ = socket(
         cur_addr->ai_family, cur_addr->ai_socktype, cur_addr->ai_protocol);
     if (sockfd_ != -1) {
       // Connect the client socket to the server socket.
       if (connect(sockfd_, cur_addr->ai_addr, cur_addr->ai_addrlen) == -1) {
         close(sockfd_);
         sockfd_ = -1;
       }
     }
   }
 
   freeaddrinfo(servinfo);  // all done with this structure
 
   if (sockfd_ == -1) {
     GTEST_LOG_(WARNING) << "stream_result_to: failed to connect to "
                         << host_name_ << ":" << port_num_;
   }
 }
 
 // End of class Streaming Listener
 #endif  // GTEST_CAN_STREAM_RESULTS__
 
 // class OsStackTraceGetter
 
 const char* const OsStackTraceGetterInterface::kElidedFramesMarker =
     "... " GTEST_NAME_ " internal frames ...";
 
 std::string OsStackTraceGetter::CurrentStackTrace(int max_depth, int skip_count)
     GTEST_LOCK_EXCLUDED_(mutex_) {
 #if GTEST_HAS_ABSL
   std::string result;
 
   if (max_depth <= 0) {
     return result;
   }
 
   max_depth = std::min(max_depth, kMaxStackTraceDepth);
 
   std::vector<void*> raw_stack(max_depth);
   // Skips the frames requested by the caller, plus this function.
   const int raw_stack_size =
       absl::GetStackTrace(&raw_stack[0], max_depth, skip_count + 1);
 
   void* caller_frame = nullptr;
   {
     MutexLock lock(&mutex_);
     caller_frame = caller_frame_;
   }
 
   for (int i = 0; i < raw_stack_size; ++i) {
     if (raw_stack[i] == caller_frame &&
         !GTEST_FLAG(show_internal_stack_frames)) {
       // Add a marker to the trace and stop adding frames.
       absl::StrAppend(&result, kElidedFramesMarker, "\n");
       break;
     }
 
     char tmp[1024];
     const char* symbol = "(unknown)";
     if (absl::Symbolize(raw_stack[i], tmp, sizeof(tmp))) {
       symbol = tmp;
     }
 
     char line[1024];
     snprintf(line, sizeof(line), "  %p: %s\n", raw_stack[i], symbol);
     result += line;
   }
 
   return result;
 
 #else  // !GTEST_HAS_ABSL
   static_cast<void>(max_depth);
   static_cast<void>(skip_count);
   return "";
 #endif  // GTEST_HAS_ABSL
 }
 
 void OsStackTraceGetter::UponLeavingGTest() GTEST_LOCK_EXCLUDED_(mutex_) {
 #if GTEST_HAS_ABSL
   void* caller_frame = nullptr;
   if (absl::GetStackTrace(&caller_frame, 1, 3) <= 0) {
     caller_frame = nullptr;
   }
 
   MutexLock lock(&mutex_);
   caller_frame_ = caller_frame;
 #endif  // GTEST_HAS_ABSL
 }
 
 // A helper class that creates the premature-exit file in its
 // constructor and deletes the file in its destructor.
 class ScopedPrematureExitFile {
  public:
   explicit ScopedPrematureExitFile(const char* premature_exit_filepath)
       : premature_exit_filepath_(premature_exit_filepath ?
                                  premature_exit_filepath : "") {
     // If a path to the premature-exit file is specified...
     if (!premature_exit_filepath_.empty()) {
       // create the file with a single "0" character in it.  I/O
       // errors are ignored as there's nothing better we can do and we
       // don't want to fail the test because of this.
       FILE* pfile = posix::FOpen(premature_exit_filepath, "w");
       fwrite("0", 1, 1, pfile);
       fclose(pfile);
     }
   }
 
   ~ScopedPrematureExitFile() {
 #if !defined GTEST_OS_ESP8266
     if (!premature_exit_filepath_.empty()) {
       int retval = remove(premature_exit_filepath_.c_str());
       if (retval) {
         GTEST_LOG_(ERROR) << "Failed to remove premature exit filepath \""
                           << premature_exit_filepath_ << "\" with error "
                           << retval;
       }
     }
 #endif
   }
 
  private:
   const std::string premature_exit_filepath_;
 
   GTEST_DISALLOW_COPY_AND_ASSIGN_(ScopedPrematureExitFile);
 };
 
 }  // namespace internal
 
 // class TestEventListeners
 
 TestEventListeners::TestEventListeners()
     : repeater_(new internal::TestEventRepeater()),
       default_result_printer_(nullptr),
       default_xml_generator_(nullptr) {}
 
 TestEventListeners::~TestEventListeners() { delete repeater_; }
 
 // Returns the standard listener responsible for the default console
 // output.  Can be removed from the listeners list to shut down default
 // console output.  Note that removing this object from the listener list
 // with Release transfers its ownership to the user.
 void TestEventListeners::Append(TestEventListener* listener) {
   repeater_->Append(listener);
 }
 
 // Removes the given event listener from the list and returns it.  It then
 // becomes the caller's responsibility to delete the listener. Returns
 // NULL if the listener is not found in the list.
 TestEventListener* TestEventListeners::Release(TestEventListener* listener) {
   if (listener == default_result_printer_)
     default_result_printer_ = nullptr;
   else if (listener == default_xml_generator_)
     default_xml_generator_ = nullptr;
   return repeater_->Release(listener);
 }
 
 // Returns repeater that broadcasts the TestEventListener events to all
 // subscribers.
 TestEventListener* TestEventListeners::repeater() { return repeater_; }
 
 // Sets the default_result_printer attribute to the provided listener.
 // The listener is also added to the listener list and previous
 // default_result_printer is removed from it and deleted. The listener can
 // also be NULL in which case it will not be added to the list. Does
 // nothing if the previous and the current listener objects are the same.
 void TestEventListeners::SetDefaultResultPrinter(TestEventListener* listener) {
   if (default_result_printer_ != listener) {
     // It is an error to pass this method a listener that is already in the
     // list.
     delete Release(default_result_printer_);
     default_result_printer_ = listener;
     if (listener != nullptr) Append(listener);
   }
 }
 
 // Sets the default_xml_generator attribute to the provided listener.  The
 // listener is also added to the listener list and previous
 // default_xml_generator is removed from it and deleted. The listener can
 // also be NULL in which case it will not be added to the list. Does
 // nothing if the previous and the current listener objects are the same.
 void TestEventListeners::SetDefaultXmlGenerator(TestEventListener* listener) {
   if (default_xml_generator_ != listener) {
     // It is an error to pass this method a listener that is already in the
     // list.
     delete Release(default_xml_generator_);
     default_xml_generator_ = listener;
     if (listener != nullptr) Append(listener);
   }
 }
 
 // Controls whether events will be forwarded by the repeater to the
 // listeners in the list.
 bool TestEventListeners::EventForwardingEnabled() const {
   return repeater_->forwarding_enabled();
 }
 
 void TestEventListeners::SuppressEventForwarding() {
   repeater_->set_forwarding_enabled(false);
 }
 
 // class UnitTest
 
 // Gets the singleton UnitTest object.  The first time this method is
 // called, a UnitTest object is constructed and returned.  Consecutive
 // calls will return the same object.
 //
 // We don't protect this under mutex_ as a user is not supposed to
 // call this before main() starts, from which point on the return
 // value will never change.
 UnitTest* UnitTest::GetInstance() {
   // CodeGear C++Builder insists on a public destructor for the
   // default implementation.  Use this implementation to keep good OO
   // design with private destructor.
 
 #if defined(__BORLANDC__)
   static UnitTest* const instance = new UnitTest;
   return instance;
 #else
   static UnitTest instance;
   return &instance;
 #endif  // defined(__BORLANDC__)
 }
 
 // Gets the number of successful test suites.
 int UnitTest::successful_test_suite_count() const {
   return impl()->successful_test_suite_count();
 }
 
 // Gets the number of failed test suites.
 int UnitTest::failed_test_suite_count() const {
   return impl()->failed_test_suite_count();
 }
 
 // Gets the number of all test suites.
 int UnitTest::total_test_suite_count() const {
   return impl()->total_test_suite_count();
 }
 
 // Gets the number of all test suites that contain at least one test
 // that should run.
 int UnitTest::test_suite_to_run_count() const {
   return impl()->test_suite_to_run_count();
 }
 
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 int UnitTest::successful_test_case_count() const {
   return impl()->successful_test_suite_count();
 }
 int UnitTest::failed_test_case_count() const {
   return impl()->failed_test_suite_count();
 }
 int UnitTest::total_test_case_count() const {
   return impl()->total_test_suite_count();
 }
 int UnitTest::test_case_to_run_count() const {
   return impl()->test_suite_to_run_count();
 }
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
 // Gets the number of successful tests.
 int UnitTest::successful_test_count() const {
   return impl()->successful_test_count();
 }
 
 // Gets the number of skipped tests.
 int UnitTest::skipped_test_count() const {
   return impl()->skipped_test_count();
 }
 
 // Gets the number of failed tests.
 int UnitTest::failed_test_count() const { return impl()->failed_test_count(); }
 
 // Gets the number of disabled tests that will be reported in the XML report.
 int UnitTest::reportable_disabled_test_count() const {
   return impl()->reportable_disabled_test_count();
 }
 
 // Gets the number of disabled tests.
 int UnitTest::disabled_test_count() const {
   return impl()->disabled_test_count();
 }
 
 // Gets the number of tests to be printed in the XML report.
 int UnitTest::reportable_test_count() const {
   return impl()->reportable_test_count();
 }
 
 // Gets the number of all tests.
 int UnitTest::total_test_count() const { return impl()->total_test_count(); }
 
 // Gets the number of tests that should run.
 int UnitTest::test_to_run_count() const { return impl()->test_to_run_count(); }
 
 // Gets the time of the test program start, in ms from the start of the
 // UNIX epoch.
 internal::TimeInMillis UnitTest::start_timestamp() const {
     return impl()->start_timestamp();
 }
 
 // Gets the elapsed time, in milliseconds.
 internal::TimeInMillis UnitTest::elapsed_time() const {
   return impl()->elapsed_time();
 }
 
 // Returns true if and only if the unit test passed (i.e. all test suites
 // passed).
 bool UnitTest::Passed() const { return impl()->Passed(); }
 
 // Returns true if and only if the unit test failed (i.e. some test suite
 // failed or something outside of all tests failed).
 bool UnitTest::Failed() const { return impl()->Failed(); }
 
 // Gets the i-th test suite among all the test suites. i can range from 0 to
 // total_test_suite_count() - 1. If i is not in that range, returns NULL.
 const TestSuite* UnitTest::GetTestSuite(int i) const {
   return impl()->GetTestSuite(i);
 }
 
 //  Legacy API is deprecated but still available
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 const TestCase* UnitTest::GetTestCase(int i) const {
   return impl()->GetTestCase(i);
 }
 #endif  //  GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 
 // Returns the TestResult containing information on test failures and
 // properties logged outside of individual test suites.
 const TestResult& UnitTest::ad_hoc_test_result() const {
   return *impl()->ad_hoc_test_result();
 }
 
 // Gets the i-th test suite among all the test suites. i can range from 0 to
 // total_test_suite_count() - 1. If i is not in that range, returns NULL.
 TestSuite* UnitTest::GetMutableTestSuite(int i) {
   return impl()->GetMutableSuiteCase(i);
 }
 
 // Returns the list of event listeners that can be used to track events
 // inside Google Test.
 TestEventListeners& UnitTest::listeners() {
   return *impl()->listeners();
 }
 
 // Registers and returns a global test environment.  When a test
 // program is run, all global test environments will be set-up in the
 // order they were registered.  After all tests in the program have
 // finished, all global test environments will be torn-down in the
 // *reverse* order they were registered.
 //
 // The UnitTest object takes ownership of the given environment.
 //
 // We don't protect this under mutex_, as we only support calling it
 // from the main thread.
 Environment* UnitTest::AddEnvironment(Environment* env) {
   if (env == nullptr) {
     return nullptr;
   }
 
   impl_->environments().push_back(env);
   return env;
 }
 
 // Adds a TestPartResult to the current TestResult object.  All Google Test
 // assertion macros (e.g. ASSERT_TRUE, EXPECT_EQ, etc) eventually call
 // this to report their results.  The user code should use the
 // assertion macros instead of calling this directly.
 void UnitTest::AddTestPartResult(
     TestPartResult::Type result_type,
     const char* file_name,
     int line_number,
     const std::string& message,
     const std::string& os_stack_trace) GTEST_LOCK_EXCLUDED_(mutex_) {
   Message msg;
   msg << message;
 
   internal::MutexLock lock(&mutex_);
   if (impl_->gtest_trace_stack().size() > 0) {
     msg << "\n" << GTEST_NAME_ << " trace:";
 
     for (size_t i = impl_->gtest_trace_stack().size(); i > 0; --i) {
       const internal::TraceInfo& trace = impl_->gtest_trace_stack()[i - 1];
       msg << "\n" << internal::FormatFileLocation(trace.file, trace.line)
           << " " << trace.message;
     }
   }
 
   if (os_stack_trace.c_str() != nullptr && !os_stack_trace.empty()) {
     msg << internal::kStackTraceMarker << os_stack_trace;
   }
 
   const TestPartResult result = TestPartResult(
       result_type, file_name, line_number, msg.GetString().c_str());
   impl_->GetTestPartResultReporterForCurrentThread()->
       ReportTestPartResult(result);
 
   if (result_type != TestPartResult::kSuccess &&
       result_type != TestPartResult::kSkip) {
     // gtest_break_on_failure takes precedence over
     // gtest_throw_on_failure.  This allows a user to set the latter
     // in the code (perhaps in order to use Google Test assertions
     // with another testing framework) and specify the former on the
     // command line for debugging.
     if (GTEST_FLAG(break_on_failure)) {
 #if GTEST_OS_WINDOWS && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
       // Using DebugBreak on Windows allows gtest to still break into a debugger
       // when a failure happens and both the --gtest_break_on_failure and
       // the --gtest_catch_exceptions flags are specified.
       DebugBreak();
 #elif (!defined(__native_client__)) &&            \
     ((defined(__clang__) || defined(__GNUC__)) && \
      (defined(__x86_64__) || defined(__i386__)))
       // with clang/gcc we can achieve the same effect on x86 by invoking int3
       asm("int3");
 #else
       // Dereference nullptr through a volatile pointer to prevent the compiler
       // from removing. We use this rather than abort() or __builtin_trap() for
       // portability: some debuggers don't correctly trap abort().
       *static_cast<volatile int*>(nullptr) = 1;
 #endif  // GTEST_OS_WINDOWS
     } else if (GTEST_FLAG(throw_on_failure)) {
 #if GTEST_HAS_EXCEPTIONS
       throw internal::GoogleTestFailureException(result);
 #else
       // We cannot call abort() as it generates a pop-up in debug mode
       // that cannot be suppressed in VC 7.1 or below.
       exit(1);
 #endif
     }
   }
 }
 
 // Adds a TestProperty to the current TestResult object when invoked from
 // inside a test, to current TestSuite's ad_hoc_test_result_ when invoked
 // from SetUpTestSuite or TearDownTestSuite, or to the global property set
 // when invoked elsewhere.  If the result already contains a property with
 // the same key, the value will be updated.
 void UnitTest::RecordProperty(const std::string& key,
                               const std::string& value) {
   impl_->RecordProperty(TestProperty(key, value));
 }
 
 // Runs all tests in this UnitTest object and prints the result.
 // Returns 0 if successful, or 1 otherwise.
 //
 // We don't protect this under mutex_, as we only support calling it
 // from the main thread.
 int UnitTest::Run() {
   const bool in_death_test_child_process =
       internal::GTEST_FLAG(internal_run_death_test).length() > 0;
 
   // Google Test implements this protocol for catching that a test
   // program exits before returning control to Google Test:
   //
   //   1. Upon start, Google Test creates a file whose absolute path
   //      is specified by the environment variable
   //      TEST_PREMATURE_EXIT_FILE.
   //   2. When Google Test has finished its work, it deletes the file.
   //
   // This allows a test runner to set TEST_PREMATURE_EXIT_FILE before
   // running a Google-Test-based test program and check the existence
   // of the file at the end of the test execution to see if it has
   // exited prematurely.
 
   // If we are in the child process of a death test, don't
   // create/delete the premature exit file, as doing so is unnecessary
   // and will confuse the parent process.  Otherwise, create/delete
   // the file upon entering/leaving this function.  If the program
   // somehow exits before this function has a chance to return, the
   // premature-exit file will be left undeleted, causing a test runner
   // that understands the premature-exit-file protocol to report the
   // test as having failed.
   const internal::ScopedPrematureExitFile premature_exit_file(
       in_death_test_child_process
           ? nullptr
           : internal::posix::GetEnv("TEST_PREMATURE_EXIT_FILE"));
 
   // Captures the value of GTEST_FLAG(catch_exceptions).  This value will be
   // used for the duration of the program.
   impl()->set_catch_exceptions(GTEST_FLAG(catch_exceptions));
 
 #if GTEST_OS_WINDOWS
   // Either the user wants Google Test to catch exceptions thrown by the
   // tests or this is executing in the context of death test child
   // process. In either case the user does not want to see pop-up dialogs
   // about crashes - they are expected.
   if (impl()->catch_exceptions() || in_death_test_child_process) {
 # if !GTEST_OS_WINDOWS_MOBILE && !GTEST_OS_WINDOWS_PHONE && !GTEST_OS_WINDOWS_RT
     // SetErrorMode doesn't exist on CE.
     SetErrorMode(SEM_FAILCRITICALERRORS | SEM_NOALIGNMENTFAULTEXCEPT |
                  SEM_NOGPFAULTERRORBOX | SEM_NOOPENFILEERRORBOX);
 # endif  // !GTEST_OS_WINDOWS_MOBILE
 
 # if (defined(_MSC_VER) || GTEST_OS_WINDOWS_MINGW) && !GTEST_OS_WINDOWS_MOBILE
     // Death test children can be terminated with _abort().  On Windows,
     // _abort() can show a dialog with a warning message.  This forces the
     // abort message to go to stderr instead.
     _set_error_mode(_OUT_TO_STDERR);
 # endif
 
 # if defined(_MSC_VER) && !GTEST_OS_WINDOWS_MOBILE
     // In the debug version, Visual Studio pops up a separate dialog
     // offering a choice to debug the aborted program. We need to suppress
     // this dialog or it will pop up for every EXPECT/ASSERT_DEATH statement
     // executed. Google Test will notify the user of any unexpected
     // failure via stderr.
     if (!GTEST_FLAG(break_on_failure))
       _set_abort_behavior(
           0x0,                                    // Clear the following flags:
           _WRITE_ABORT_MSG | _CALL_REPORTFAULT);  // pop-up window, core dump.
 
     // In debug mode, the Windows CRT can crash with an assertion over invalid
     // input (e.g. passing an invalid file descriptor).  The default handling
     // for these assertions is to pop up a dialog and wait for user input.
     // Instead ask the CRT to dump such assertions to stderr non-interactively.
     if (!IsDebuggerPresent()) {
       (void)_CrtSetReportMode(_CRT_ASSERT,
                               _CRTDBG_MODE_FILE | _CRTDBG_MODE_DEBUG);
       (void)_CrtSetReportFile(_CRT_ASSERT, _CRTDBG_FILE_STDERR);
     }
 # endif
   }
 #endif  // GTEST_OS_WINDOWS
 
   return internal::HandleExceptionsInMethodIfSupported(
       impl(),
       &internal::UnitTestImpl::RunAllTests,
       "auxiliary test code (environments or event listeners)") ? 0 : 1;
 }
 
 // Returns the working directory when the first TEST() or TEST_F() was
 // executed.
 const char* UnitTest::original_working_dir() const {
   return impl_->original_working_dir_.c_str();
 }
 
 // Returns the TestSuite object for the test that's currently running,
 // or NULL if no test is running.
 const TestSuite* UnitTest::current_test_suite() const
     GTEST_LOCK_EXCLUDED_(mutex_) {
   internal::MutexLock lock(&mutex_);
   return impl_->current_test_suite();
 }
 
 // Legacy API is still available but deprecated
 #ifndef GTEST_REMOVE_LEGACY_TEST_CASEAPI_
 const TestCase* UnitTest::current_test_case() const
     GTEST_LOCK_EXCLUDED_(mutex_) {
   internal::MutexLock lock(&mutex_);
   return impl_->current_test_suite();
 }
 #endif
 
 // Returns the TestInfo object for the test that's currently running,
 // or NULL if no test is running.
 const TestInfo* UnitTest::current_test_info() const
     GTEST_LOCK_EXCLUDED_(mutex_) {
   internal::MutexLock lock(&mutex_);
   return impl_->current_test_info();
 }
 
 // Returns the random seed used at the start of the current test run.
 int UnitTest::random_seed() const { return impl_->random_seed(); }
 
 // Returns ParameterizedTestSuiteRegistry object used to keep track of
 // value-parameterized tests and instantiate and register them.
 internal::ParameterizedTestSuiteRegistry&
 UnitTest::parameterized_test_registry() GTEST_LOCK_EXCLUDED_(mutex_) {
   return impl_->parameterized_test_registry();
 }
 
 // Creates an empty UnitTest.
 UnitTest::UnitTest() {
   impl_ = new internal::UnitTestImpl(this);
 }
 
 // Destructor of UnitTest.
 UnitTest::~UnitTest() {
   delete impl_;
 }
 
 // Pushes a trace defined by SCOPED_TRACE() on to the per-thread
 // Google Test trace stack.
 void UnitTest::PushGTestTrace(const internal::TraceInfo& trace)
     GTEST_LOCK_EXCLUDED_(mutex_) {
   internal::MutexLock lock(&mutex_);
   impl_->gtest_trace_stack().push_back(trace);
 }
 
 // Pops a trace from the per-thread Google Test trace stack.
 void UnitTest::PopGTestTrace()
     GTEST_LOCK_EXCLUDED_(mutex_) {
   internal::MutexLock lock(&mutex_);
   impl_->gtest_trace_stack().pop_back();
 }
 
 namespace internal {
 
 UnitTestImpl::UnitTestImpl(UnitTest* parent)
     : parent_(parent),
       GTEST_DISABLE_MSC_WARNINGS_PUSH_(4355 /* using this in initializer */)
           default_global_test_part_result_reporter_(this),
       default_per_thread_test_part_result_reporter_(this),
       GTEST_DISABLE_MSC_WARNINGS_POP_() global_test_part_result_repoter_(
           &default_global_test_part_result_reporter_),
       per_thread_test_part_result_reporter_(
           &default_per_thread_test_part_result_reporter_),
       parameterized_test_registry_(),
       parameterized_tests_registered_(false),
       last_death_test_suite_(-1),
       current_test_suite_(nullptr),
       current_test_info_(nullptr),
       ad_hoc_test_result_(),
       os_stack_trace_getter_(nullptr),
       post_flag_parse_init_performed_(false),
       random_seed_(0),  // Will be overridden by the flag before first use.
       random_(0),       // Will be reseeded before first use.
       start_timestamp_(0),
       elapsed_time_(0),
 #if GTEST_HAS_DEATH_TEST
       death_test_factory_(new DefaultDeathTestFactory),
 #endif
       // Will be overridden by the flag before first use.
       catch_exceptions_(false) {
   listeners()->SetDefaultResultPrinter(new PrettyUnitTestResultPrinter);
 }
 
 UnitTestImpl::~UnitTestImpl() {
   // Deletes every TestSuite.
   ForEach(test_suites_, internal::Delete<TestSuite>);
 
   // Deletes every Environment.
   ForEach(environments_, internal::Delete<Environment>);
 
   delete os_stack_trace_getter_;
 }
 
 // Adds a TestProperty to the current TestResult object when invoked in a
 // context of a test, to current test suite's ad_hoc_test_result when invoke
 // from SetUpTestSuite/TearDownTestSuite, or to the global property set
 // otherwise.  If the result already contains a property with the same key,
 // the value will be updated.
 void UnitTestImpl::RecordProperty(const TestProperty& test_property) {
   std::string xml_element;
   TestResult* test_result;  // TestResult appropriate for property recording.
 
   if (current_test_info_ != nullptr) {
     xml_element = "testcase";
     test_result = &(current_test_info_->result_);
   } else if (current_test_suite_ != nullptr) {
     xml_element = "testsuite";
     test_result = &(current_test_suite_->ad_hoc_test_result_);
   } else {
     xml_element = "testsuites";
     test_result = &ad_hoc_test_result_;
   }
   test_result->RecordProperty(xml_element, test_property);
 }
 
 #if GTEST_HAS_DEATH_TEST
 // Disables event forwarding if the control is currently in a death test
 // subprocess. Must not be called before InitGoogleTest.
 void UnitTestImpl::SuppressTestEventsIfInSubprocess() {
   if (internal_run_death_test_flag_.get() != nullptr)
     listeners()->SuppressEventForwarding();
 }
 #endif  // GTEST_HAS_DEATH_TEST
 
 // Initializes event listeners performing XML output as specified by
 // UnitTestOptions. Must not be called before InitGoogleTest.
 void UnitTestImpl::ConfigureXmlOutput() {
   const std::string& output_format = UnitTestOptions::GetOutputFormat();
   if (output_format == "xml") {
     listeners()->SetDefaultXmlGenerator(new XmlUnitTestResultPrinter(
         UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
   } else if (output_format == "json") {
     listeners()->SetDefaultXmlGenerator(new JsonUnitTestResultPrinter(
         UnitTestOptions::GetAbsolutePathToOutputFile().c_str()));
   } else if (output_format != "") {
     GTEST_LOG_(WARNING) << "WARNING: unrecognized output format \""
                         << output_format << "\" ignored.";
   }
 }
 
 #if GTEST_CAN_STREAM_RESULTS_
 // Initializes event listeners for streaming test results in string form.
 // Must not be called before InitGoogleTest.
 void UnitTestImpl::ConfigureStreamingOutput() {
   const std::string& target = GTEST_FLAG(stream_result_to);
   if (!target.empty()) {
     const size_t pos = target.find(':');
     if (pos != std::string::npos) {
       listeners()->Append(new StreamingListener(target.substr(0, pos),
                                                 target.substr(pos+1)));
     } else {
       GTEST_LOG_(WARNING) << "unrecognized streaming target \"" << target
                           << "\" ignored.";
     }
   }
 }
 #endif  // GTEST_CAN_STREAM_RESULTS_
 
 // Performs initialization dependent upon flag values obtained in
 // ParseGoogleTestFlagsOnly.  Is called from InitGoogleTest after the call to
 // ParseGoogleTestFlagsOnly.  In case a user neglects to call InitGoogleTest
 // this function is also called from RunAllTests.  Since this function can be
 // called more than once, it has to be idempotent.
 void UnitTestImpl::PostFlagParsingInit() {
   // Ensures that this function does not execute more than once.
   if (!post_flag_parse_init_performed_) {
     post_flag_parse_init_performed_ = true;
 
 #if defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
     // Register to send notifications about key process state changes.
     listeners()->Append(new GTEST_CUSTOM_TEST_EVENT_LISTENER_());
 #endif  // defined(GTEST_CUSTOM_TEST_EVENT_LISTENER_)
 
 #if GTEST_HAS_DEATH_TEST
     InitDeathTestSubprocessControlInfo();
     SuppressTestEventsIfInSubprocess();
 #endif  // GTEST_HAS_DEATH_TEST
 
     // Registers parameterized tests. This makes parameterized tests
     // available to the UnitTest reflection API without running
     // RUN_ALL_TESTS.
     RegisterParameterizedTests();
 
     // Configures listeners for XML output. This makes it possible for users
     // to shut down the default XML output before invoking RUN_ALL_TESTS.
     ConfigureXmlOutput();
 
 #if GTEST_CAN_STREAM_RESULTS_
     // Configures listeners for streaming test results to the specified server.
     ConfigureStreamingOutput();
 #endif  // GTEST_CAN_STREAM_RESULTS_
 
 #if GTEST_HAS_ABSL
     if (GTEST_FLAG(install_failure_signal_handler)) {
       absl::FailureSignalHandlerOptions options;
       absl::InstallFailureSignalHandler(options);
     }
 #endif  // GTEST_HAS_ABSL
   }
 }
 
 // A predicate that checks the name of a TestSuite against a known
 // value.
 //
 // This is used for implementation of the UnitTest class only.  We put
 // it in the anonymous namespace to prevent polluting the outer
 // namespace.
 //
 // TestSuiteNameIs is copyable.
 class TestSuiteNameIs {
  public:
   // Constructor.
   explicit TestSuiteNameIs(const std::string& name) : name_(name) {}
 
   // Returns true if and only if the name of test_suite matches name_.
   bool operator()(const TestSuite* test_suite) const {
     return test_suite != nullptr &&
            strcmp(test_suite->name(), name_.c_str()) == 0;
   }
 
  private:
   std::string name_;
 };
 
 // Finds and returns a TestSuite with the given name.  If one doesn't
 // exist, creates one and returns it.  It's the CALLER'S
 // RESPONSIBILITY to ensure that this function is only called WHEN THE
 // TESTS ARE NOT SHUFFLED.
 //
 // Arguments:
 //
 //   test_suite_name: name of the test suite
 //   type_param:     the name of the test suite's type parameter, or NULL if
 //                   this is not a typed or a type-parameterized test suite.
 //   set_up_tc:      pointer to the function that sets up the test suite
 //   tear_down_tc:   pointer to the function that tears down the test suite
 TestSuite* UnitTestImpl::GetTestSuite(
     const char* test_suite_name, const char* type_param,
     internal::SetUpTestSuiteFunc set_up_tc,
     internal::TearDownTestSuiteFunc tear_down_tc) {
   // Can we find a TestSuite with the given name?
   const auto test_suite =
       std::find_if(test_suites_.rbegin(), test_suites_.rend(),
                    TestSuiteNameIs(test_suite_name));
 
   if (test_suite != test_suites_.rend()) return *test_suite;
 
   // No.  Let's create one.
   auto* const new_test_suite =
       new TestSuite(test_suite_name, type_param, set_up_tc, tear_down_tc);
 
   // Is this a death test suite?
   if (internal::UnitTestOptions::MatchesFilter(test_suite_name,
                                                kDeathTestSuiteFilter)) {
     // Yes.  Inserts the test suite after the last death test suite
     // defined so far.  This only works when the test suites haven't
     // been shuffled.  Otherwise we may end up running a death test
     // after a non-death test.
     ++last_death_test_suite_;
     test_suites_.insert(test_suites_.begin() + last_death_test_suite_,
                         new_test_suite);
   } else {
     // No.  Appends to the end of the list.
     test_suites_.push_back(new_test_suite);
   }
 
   test_suite_indices_.push_back(static_cast<int>(test_suite_indices_.size()));
   return new_test_suite;
 }
 
 // Helpers for setting up / tearing down the given environment.  They
 // are for use in the ForEach() function.
 static void SetUpEnvironment(Environment* env) { env->SetUp(); }
 static void TearDownEnvironment(Environment* env) { env->TearDown(); }
 
 // Runs all tests in this UnitTest object, prints the result, and
 // returns true if all tests are successful.  If any exception is
 // thrown during a test, the test is considered to be failed, but the
 // rest of the tests will still be run.
 //
 // When parameterized tests are enabled, it expands and registers
 // parameterized tests first in RegisterParameterizedTests().
 // All other functions called from RunAllTests() may safely assume that
 // parameterized tests are ready to be counted and run.
 bool UnitTestImpl::RunAllTests() {
   // True if and only if Google Test is initialized before RUN_ALL_TESTS() is
   // called.
   const bool gtest_is_initialized_before_run_all_tests = GTestIsInitialized();
 
   // Do not run any test if the --help flag was specified.
   if (g_help_flag)
     return true;
 
   // Repeats the call to the post-flag parsing initialization in case the
   // user didn't call InitGoogleTest.
   PostFlagParsingInit();
 
   // Even if sharding is not on, test runners may want to use the
   // GTEST_SHARD_STATUS_FILE to query whether the test supports the sharding
   // protocol.
   internal::WriteToShardStatusFileIfNeeded();
 
   // True if and only if we are in a subprocess for running a thread-safe-style
   // death test.
   bool in_subprocess_for_death_test = false;
 
 #if GTEST_HAS_DEATH_TEST
   in_subprocess_for_death_test =
       (internal_run_death_test_flag_.get() != nullptr);
 # if defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
   if (in_subprocess_for_death_test) {
     GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_();
   }
 # endif  // defined(GTEST_EXTRA_DEATH_TEST_CHILD_SETUP_)
 #endif  // GTEST_HAS_DEATH_TEST
 
   const bool should_shard = ShouldShard(kTestTotalShards, kTestShardIndex,
                                         in_subprocess_for_death_test);
 
   // Compares the full test names with the filter to decide which
   // tests to run.
   const bool has_tests_to_run = FilterTests(should_shard
                                               ? HONOR_SHARDING_PROTOCOL
                                               : IGNORE_SHARDING_PROTOCOL) > 0;
 
   // Lists the tests and exits if the --gtest_list_tests flag was specified.
   if (GTEST_FLAG(list_tests)) {
     // This must be called *after* FilterTests() has been called.
     ListTestsMatchingFilter();
     return true;
   }
 
   random_seed_ = GTEST_FLAG(shuffle) ?
       GetRandomSeedFromFlag(GTEST_FLAG(random_seed)) : 0;
 
   // True if and only if at least one test has failed.
   bool failed = false;
 
   TestEventListener* repeater = listeners()->repeater();
 
   start_timestamp_ = GetTimeInMillis();
   repeater->OnTestProgramStart(*parent_);
 
   // How many times to repeat the tests?  We don't want to repeat them
   // when we are inside the subprocess of a death test.
   const int repeat = in_subprocess_for_death_test ? 1 : GTEST_FLAG(repeat);
   // Repeats forever if the repeat count is negative.
   const bool gtest_repeat_forever = repeat < 0;
   for (int i = 0; gtest_repeat_forever || i != repeat; i++) {
     // We want to preserve failures generated by ad-hoc test
     // assertions executed before RUN_ALL_TESTS().
     ClearNonAdHocTestResult();
 
     const TimeInMillis start = GetTimeInMillis();
 
     // Shuffles test suites and tests if requested.
     if (has_tests_to_run && GTEST_FLAG(shuffle)) {
       random()->Reseed(static_cast<uint32_t>(random_seed_));
       // This should be done before calling OnTestIterationStart(),
       // such that a test event listener can see the actual test order
       // in the event.
       ShuffleTests();
     }
 
     // Tells the unit test event listeners that the tests are about to start.
     repeater->OnTestIterationStart(*parent_, i);
 
     // Runs each test suite if there is at least one test to run.
     if (has_tests_to_run) {
       // Sets up all environments beforehand.
       repeater->OnEnvironmentsSetUpStart(*parent_);
       ForEach(environments_, SetUpEnvironment);
       repeater->OnEnvironmentsSetUpEnd(*parent_);
 
       // Runs the tests only if there was no fatal failure or skip triggered
       // during global set-up.
       if (Test::IsSkipped()) {
         // Emit diagnostics when global set-up calls skip, as it will not be
         // emitted by default.
         TestResult& test_result =
             *internal::GetUnitTestImpl()->current_test_result();
         for (int j = 0; j < test_result.total_part_count(); ++j) {
           const TestPartResult& test_part_result =
               test_result.GetTestPartResult(j);
           if (test_part_result.type() == TestPartResult::kSkip) {
             const std::string& result = test_part_result.message();
             printf("%s\n", result.c_str());
           }
         }
         fflush(stdout);
       } else if (!Test::HasFatalFailure()) {
         for (int test_index = 0; test_index < total_test_suite_count();
              test_index++) {
           GetMutableSuiteCase(test_index)->Run();
         }
       }
 
       // Tears down all environments in reverse order afterwards.
       repeater->OnEnvironmentsTearDownStart(*parent_);
       std::for_each(environments_.rbegin(), environments_.rend(),
                     TearDownEnvironment);
       repeater->OnEnvironmentsTearDownEnd(*parent_);
     }
 
     elapsed_time_ = GetTimeInMillis() - start;
 
     // Tells the unit test event listener that the tests have just finished.
     repeater->OnTestIterationEnd(*parent_, i);
 
     // Gets the result and clears it.
     if (!Passed()) {
       failed = true;
     }
 
     // Restores the original test order after the iteration.  This
     // allows the user to quickly repro a failure that happens in the
     // N-th iteration without repeating the first (N - 1) iterations.
     // This is not enclosed in "if (GTEST_FLAG(shuffle)) { ... }", in
     // case the user somehow changes the value of the flag somewhere
     // (it's always safe to unshuffle the tests).
     UnshuffleTests();
 
     if (GTEST_FLAG(shuffle)) {
       // Picks a new random seed for each iteration.
       random_seed_ = GetNextRandomSeed(random_seed_);
     }
   }
 
   repeater->OnTestProgramEnd(*parent_);
 
   if (!gtest_is_initialized_before_run_all_tests) {
     ColoredPrintf(
         GTestColor::kRed,
         "\nIMPORTANT NOTICE - DO NOT IGNORE:\n"
         "This test program did NOT call " GTEST_INIT_GOOGLE_TEST_NAME_
         "() before calling RUN_ALL_TESTS(). This is INVALID. Soon " GTEST_NAME_
         " will start to enforce the valid usage. "
         "Please fix it ASAP, or IT WILL START TO FAIL.\n");  // NOLINT
 #if GTEST_FOR_GOOGLE_
     ColoredPrintf(GTestColor::kRed,
                   "For more details, see http://wiki/Main/ValidGUnitMain.\n");
 #endif  // GTEST_FOR_GOOGLE_
   }
 
   return !failed;
 }
 
 // Reads the GTEST_SHARD_STATUS_FILE environment variable, and creates the file
 // if the variable is present. If a file already exists at this location, this
 // function will write over it. If the variable is present, but the file cannot
 // be created, prints an error and exits.
 void WriteToShardStatusFileIfNeeded() {
   const char* const test_shard_file = posix::GetEnv(kTestShardStatusFile);
   if (test_shard_file != nullptr) {
     FILE* const file = posix::FOpen(test_shard_file, "w");
     if (file == nullptr) {
       ColoredPrintf(GTestColor::kRed,
                     "Could not write to the test shard status file \"%s\" "
                     "specified by the %s environment variable.\n",
                     test_shard_file, kTestShardStatusFile);
       fflush(stdout);
       exit(EXIT_FAILURE);
     }
     fclose(file);
   }
 }
 
 // Checks whether sharding is enabled by examining the relevant
 // environment variable values. If the variables are present,
 // but inconsistent (i.e., shard_index >= total_shards), prints
 // an error and exits. If in_subprocess_for_death_test, sharding is
 // disabled because it must only be applied to the original test
 // process. Otherwise, we could filter out death tests we intended to execute.
 bool ShouldShard(const char* total_shards_env,
                  const char* shard_index_env,
                  bool in_subprocess_for_death_test) {
   if (in_subprocess_for_death_test) {
     return false;
   }
 
   const int32_t total_shards = Int32FromEnvOrDie(total_shards_env, -1);
   const int32_t shard_index = Int32FromEnvOrDie(shard_index_env, -1);
 
   if (total_shards == -1 && shard_index == -1) {
     return false;
   } else if (total_shards == -1 && shard_index != -1) {
     const Message msg = Message()
       << "Invalid environment variables: you have "
       << kTestShardIndex << " = " << shard_index
       << ", but have left " << kTestTotalShards << " unset.\n";
     ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
     fflush(stdout);
     exit(EXIT_FAILURE);
   } else if (total_shards != -1 && shard_index == -1) {
     const Message msg = Message()
       << "Invalid environment variables: you have "
       << kTestTotalShards << " = " << total_shards
       << ", but have left " << kTestShardIndex << " unset.\n";
     ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
     fflush(stdout);
     exit(EXIT_FAILURE);
   } else if (shard_index < 0 || shard_index >= total_shards) {
     const Message msg = Message()
       << "Invalid environment variables: we require 0 <= "
       << kTestShardIndex << " < " << kTestTotalShards
       << ", but you have " << kTestShardIndex << "=" << shard_index
       << ", " << kTestTotalShards << "=" << total_shards << ".\n";
     ColoredPrintf(GTestColor::kRed, "%s", msg.GetString().c_str());
     fflush(stdout);
     exit(EXIT_FAILURE);
   }
 
   return total_shards > 1;
 }
 
 // Parses the environment variable var as an Int32. If it is unset,
 // returns default_val. If it is not an Int32, prints an error
 // and aborts.
 int32_t Int32FromEnvOrDie(const char* var, int32_t default_val) {
   const char* str_val = posix::GetEnv(var);
   if (str_val == nullptr) {
     return default_val;
   }
 
   int32_t result;
   if (!ParseInt32(Message() << "The value of environment variable " << var,
                   str_val, &result)) {
     exit(EXIT_FAILURE);
   }
   return result;
 }
 
 // Given the total number of shards, the shard index, and the test id,
 // returns true if and only if the test should be run on this shard. The test id
 // is some arbitrary but unique non-negative integer assigned to each test
 // method. Assumes that 0 <= shard_index < total_shards.
 bool ShouldRunTestOnShard(int total_shards, int shard_index, int test_id) {
   return (test_id % total_shards) == shard_index;
 }
 
 // Compares the name of each test with the user-specified filter to
 // decide whether the test should be run, then records the result in
 // each TestSuite and TestInfo object.
 // If shard_tests == true, further filters tests based on sharding
 // variables in the environment - see
 // https://github.com/google/googletest/blob/master/googletest/docs/advanced.md
 // . Returns the number of tests that should run.
 int UnitTestImpl::FilterTests(ReactionToSharding shard_tests) {
   const int32_t total_shards = shard_tests == HONOR_SHARDING_PROTOCOL ?
       Int32FromEnvOrDie(kTestTotalShards, -1) : -1;
   const int32_t shard_index = shard_tests == HONOR_SHARDING_PROTOCOL ?
       Int32FromEnvOrDie(kTestShardIndex, -1) : -1;
 
   // num_runnable_tests are the number of tests that will
   // run across all shards (i.e., match filter and are not disabled).
   // num_selected_tests are the number of tests to be run on
   // this shard.
   int num_runnable_tests = 0;
   int num_selected_tests = 0;
   for (auto* test_suite : test_suites_) {
     const std::string& test_suite_name = test_suite->name();
     test_suite->set_should_run(false);
 
     for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
       TestInfo* const test_info = test_suite->test_info_list()[j];
       const std::string test_name(test_info->name());
       // A test is disabled if test suite name or test name matches
       // kDisableTestFilter.
       const bool is_disabled = internal::UnitTestOptions::MatchesFilter(
                                    test_suite_name, kDisableTestFilter) ||
                                internal::UnitTestOptions::MatchesFilter(
                                    test_name, kDisableTestFilter);
       test_info->is_disabled_ = is_disabled;
 
       const bool matches_filter = internal::UnitTestOptions::FilterMatchesTest(
           test_suite_name, test_name);
       test_info->matches_filter_ = matches_filter;
 
       const bool is_runnable =
           (GTEST_FLAG(also_run_disabled_tests) || !is_disabled) &&
           matches_filter;
 
       const bool is_in_another_shard =
           shard_tests != IGNORE_SHARDING_PROTOCOL &&
           !ShouldRunTestOnShard(total_shards, shard_index, num_runnable_tests);
       test_info->is_in_another_shard_ = is_in_another_shard;
       const bool is_selected = is_runnable && !is_in_another_shard;
 
       num_runnable_tests += is_runnable;
       num_selected_tests += is_selected;
 
       test_info->should_run_ = is_selected;
       test_suite->set_should_run(test_suite->should_run() || is_selected);
     }
   }
   return num_selected_tests;
 }
 
 // Prints the given C-string on a single line by replacing all '\n'
 // characters with string "\\n".  If the output takes more than
 // max_length characters, only prints the first max_length characters
 // and "...".
 static void PrintOnOneLine(const char* str, int max_length) {
   if (str != nullptr) {
     for (int i = 0; *str != '\0'; ++str) {
       if (i >= max_length) {
         printf("...");
         break;
       }
       if (*str == '\n') {
         printf("\\n");
         i += 2;
       } else {
         printf("%c", *str);
         ++i;
       }
     }
   }
 }
 
 // Prints the names of the tests matching the user-specified filter flag.
 void UnitTestImpl::ListTestsMatchingFilter() {
   // Print at most this many characters for each type/value parameter.
   const int kMaxParamLength = 250;
 
   for (auto* test_suite : test_suites_) {
     bool printed_test_suite_name = false;
 
     for (size_t j = 0; j < test_suite->test_info_list().size(); j++) {
       const TestInfo* const test_info = test_suite->test_info_list()[j];
       if (test_info->matches_filter_) {
         if (!printed_test_suite_name) {
           printed_test_suite_name = true;
           printf("%s.", test_suite->name());
           if (test_suite->type_param() != nullptr) {
             printf("  # %s = ", kTypeParamLabel);
             // We print the type parameter on a single line to make
             // the output easy to parse by a program.
             PrintOnOneLine(test_suite->type_param(), kMaxParamLength);
           }
           printf("\n");
         }
         printf("  %s", test_info->name());
         if (test_info->value_param() != nullptr) {
           printf("  # %s = ", kValueParamLabel);
           // We print the value parameter on a single line to make the
           // output easy to parse by a program.
           PrintOnOneLine(test_info->value_param(), kMaxParamLength);
         }
         printf("\n");
       }
     }
   }
   fflush(stdout);
   const std::string& output_format = UnitTestOptions::GetOutputFormat();
   if (output_format == "xml" || output_format == "json") {
     FILE* fileout = OpenFileForWriting(
         UnitTestOptions::GetAbsolutePathToOutputFile().c_str());
     std::stringstream stream;
     if (output_format == "xml") {
       XmlUnitTestResultPrinter(
           UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
           .PrintXmlTestsList(&stream, test_suites_);
     } else if (output_format == "json") {
       JsonUnitTestResultPrinter(
           UnitTestOptions::GetAbsolutePathToOutputFile().c_str())
           .PrintJsonTestList(&stream, test_suites_);
     }
     fprintf(fileout, "%s", StringStreamToString(&stream).c_str());
     fclose(fileout);
   }
 }
 
 // Sets the OS stack trace getter.
 //
 // Does nothing if the input and the current OS stack trace getter are
 // the same; otherwise, deletes the old getter and makes the input the
 // current getter.
 void UnitTestImpl::set_os_stack_trace_getter(
     OsStackTraceGetterInterface* getter) {
   if (os_stack_trace_getter_ != getter) {
     delete os_stack_trace_getter_;
     os_stack_trace_getter_ = getter;
   }
 }
 
 // Returns the current OS stack trace getter if it is not NULL;
 // otherwise, creates an OsStackTraceGetter, makes it the current
 // getter, and returns it.
 OsStackTraceGetterInterface* UnitTestImpl::os_stack_trace_getter() {
   if (os_stack_trace_getter_ == nullptr) {
 #ifdef GTEST_OS_STACK_TRACE_GETTER_
     os_stack_trace_getter_ = new GTEST_OS_STACK_TRACE_GETTER_;
 #else
     os_stack_trace_getter_ = new OsStackTraceGetter;
 #endif  // GTEST_OS_STACK_TRACE_GETTER_
   }
 
   return os_stack_trace_getter_;
 }
 
 // Returns the most specific TestResult currently running.
 TestResult* UnitTestImpl::current_test_result() {
   if (current_test_info_ != nullptr) {
     return &current_test_info_->result_;
   }
   if (current_test_suite_ != nullptr) {
     return &current_test_suite_->ad_hoc_test_result_;
   }
   return &ad_hoc_test_result_;
 }
 
 // Shuffles all test suites, and the tests within each test suite,
 // making sure that death tests are still run first.
 void UnitTestImpl::ShuffleTests() {
   // Shuffles the death test suites.
   ShuffleRange(random(), 0, last_death_test_suite_ + 1, &test_suite_indices_);
 
   // Shuffles the non-death test suites.
   ShuffleRange(random(), last_death_test_suite_ + 1,
                static_cast<int>(test_suites_.size()), &test_suite_indices_);
 
   // Shuffles the tests inside each test suite.
   for (auto& test_suite : test_suites_) {
     test_suite->ShuffleTests(random());
   }
 }
 
 // Restores the test suites and tests to their order before the first shuffle.
 void UnitTestImpl::UnshuffleTests() {
   for (size_t i = 0; i < test_suites_.size(); i++) {
     // Unshuffles the tests in each test suite.
     test_suites_[i]->UnshuffleTests();
     // Resets the index of each test suite.
     test_suite_indices_[i] = static_cast<int>(i);
   }
 }
 
 // Returns the current OS stack trace as an std::string.
 //
 // The maximum number of stack frames to be included is specified by
 // the gtest_stack_trace_depth flag.  The skip_count parameter
 // specifies the number of top frames to be skipped, which doesn't
 // count against the number of frames to be included.
 //
 // For example, if Foo() calls Bar(), which in turn calls
 // GetCurrentOsStackTraceExceptTop(..., 1), Foo() will be included in
 // the trace but Bar() and GetCurrentOsStackTraceExceptTop() won't.
 std::string GetCurrentOsStackTraceExceptTop(UnitTest* /*unit_test*/,
                                             int skip_count) {
   // We pass skip_count + 1 to skip this wrapper function in addition
   // to what the user really wants to skip.
   return GetUnitTestImpl()->CurrentOsStackTraceExceptTop(skip_count + 1);
 }
 
 // Used by the GTEST_SUPPRESS_UNREACHABLE_CODE_WARNING_BELOW_ macro to
 // suppress unreachable code warnings.
 namespace {
 class ClassUniqueToAlwaysTrue {};
 }
 
 bool IsTrue(bool condition) { return condition; }
 
 bool AlwaysTrue() {
 #if GTEST_HAS_EXCEPTIONS
   // This condition is always false so AlwaysTrue() never actually throws,
   // but it makes the compiler think that it may throw.
   if (IsTrue(false))
     throw ClassUniqueToAlwaysTrue();
 #endif  // GTEST_HAS_EXCEPTIONS
   return true;
 }
 
 // If *pstr starts with the given prefix, modifies *pstr to be right
 // past the prefix and returns true; otherwise leaves *pstr unchanged
 // and returns false.  None of pstr, *pstr, and prefix can be NULL.
 bool SkipPrefix(const char* prefix, const char** pstr) {
   const size_t prefix_len = strlen(prefix);
   if (strncmp(*pstr, prefix, prefix_len) == 0) {
     *pstr += prefix_len;
     return true;
   }
   return false;
 }
 
 // Parses a string as a command line flag.  The string should have
 // the format "--flag=value".  When def_optional is true, the "=value"
 // part can be omitted.
 //
 // Returns the value of the flag, or NULL if the parsing failed.
 static const char* ParseFlagValue(const char* str, const char* flag,
                                   bool def_optional) {
   // str and flag must not be NULL.
   if (str == nullptr || flag == nullptr) return nullptr;
 
   // The flag must start with "--" followed by GTEST_FLAG_PREFIX_.
   const std::string flag_str = std::string("--") + GTEST_FLAG_PREFIX_ + flag;
   const size_t flag_len = flag_str.length();
   if (strncmp(str, flag_str.c_str(), flag_len) != 0) return nullptr;
 
   // Skips the flag name.
   const char* flag_end = str + flag_len;
 
   // When def_optional is true, it's OK to not have a "=value" part.
   if (def_optional && (flag_end[0] == '\0')) {
     return flag_end;
   }
 
   // If def_optional is true and there are more characters after the
   // flag name, or if def_optional is false, there must be a '=' after
   // the flag name.
   if (flag_end[0] != '=') return nullptr;
 
   // Returns the string after "=".
   return flag_end + 1;
 }
 
 // Parses a string for a bool flag, in the form of either
 // "--flag=value" or "--flag".
 //
 // In the former case, the value is taken as true as long as it does
 // not start with '0', 'f', or 'F'.
 //
 // In the latter case, the value is taken as true.
 //
 // On success, stores the value of the flag in *value, and returns
 // true.  On failure, returns false without changing *value.
 static bool ParseBoolFlag(const char* str, const char* flag, bool* value) {
   // Gets the value of the flag as a string.
   const char* const value_str = ParseFlagValue(str, flag, true);
 
   // Aborts if the parsing failed.
   if (value_str == nullptr) return false;
 
   // Converts the string value to a bool.
   *value = !(*value_str == '0' || *value_str == 'f' || *value_str == 'F');
   return true;
 }
 
 // Parses a string for an int32_t flag, in the form of "--flag=value".
 //
 // On success, stores the value of the flag in *value, and returns
 // true.  On failure, returns false without changing *value.
 bool ParseInt32Flag(const char* str, const char* flag, int32_t* value) {
   // Gets the value of the flag as a string.
   const char* const value_str = ParseFlagValue(str, flag, false);
 
   // Aborts if the parsing failed.
   if (value_str == nullptr) return false;
 
   // Sets *value to the value of the flag.
   return ParseInt32(Message() << "The value of flag --" << flag,
                     value_str, value);
 }
 
 // Parses a string for a string flag, in the form of "--flag=value".
 //
 // On success, stores the value of the flag in *value, and returns
 // true.  On failure, returns false without changing *value.
 template <typename String>
 static bool ParseStringFlag(const char* str, const char* flag, String* value) {
   // Gets the value of the flag as a string.
   const char* const value_str = ParseFlagValue(str, flag, false);
 
   // Aborts if the parsing failed.
   if (value_str == nullptr) return false;
 
   // Sets *value to the value of the flag.
   *value = value_str;
   return true;
 }
 
 // Determines whether a string has a prefix that Google Test uses for its
 // flags, i.e., starts with GTEST_FLAG_PREFIX_ or GTEST_FLAG_PREFIX_DASH_.
 // If Google Test detects that a command line flag has its prefix but is not
 // recognized, it will print its help message. Flags starting with
 // GTEST_INTERNAL_PREFIX_ followed by "internal_" are considered Google Test
 // internal flags and do not trigger the help message.
 static bool HasGoogleTestFlagPrefix(const char* str) {
   return (SkipPrefix("--", &str) ||
           SkipPrefix("-", &str) ||
           SkipPrefix("/", &str)) &&
          !SkipPrefix(GTEST_FLAG_PREFIX_ "internal_", &str) &&
          (SkipPrefix(GTEST_FLAG_PREFIX_, &str) ||
           SkipPrefix(GTEST_FLAG_PREFIX_DASH_, &str));
 }
 
 // Prints a string containing code-encoded text.  The following escape
 // sequences can be used in the string to control the text color:
 //
 //   @@    prints a single '@' character.
 //   @R    changes the color to red.
 //   @G    changes the color to green.
 //   @Y    changes the color to yellow.
 //   @D    changes to the default terminal text color.
 //
 static void PrintColorEncoded(const char* str) {
   GTestColor color = GTestColor::kDefault;  // The current color.
 
   // Conceptually, we split the string into segments divided by escape
   // sequences.  Then we print one segment at a time.  At the end of
   // each iteration, the str pointer advances to the beginning of the
   // next segment.
   for (;;) {
     const char* p = strchr(str, '@');
     if (p == nullptr) {
       ColoredPrintf(color, "%s", str);
       return;
     }
 
     ColoredPrintf(color, "%s", std::string(str, p).c_str());
 
     const char ch = p[1];
     str = p + 2;
     if (ch == '@') {
       ColoredPrintf(color, "@");
     } else if (ch == 'D') {
       color = GTestColor::kDefault;
     } else if (ch == 'R') {
       color = GTestColor::kRed;
     } else if (ch == 'G') {
       color = GTestColor::kGreen;
     } else if (ch == 'Y') {
       color = GTestColor::kYellow;
     } else {
       --str;
     }
   }
 }
 
 static const char kColorEncodedHelpMessage[] =
 "This program contains tests written using " GTEST_NAME_ ". You can use the\n"
 "following command line flags to control its behavior:\n"
 "\n"
 "Test Selection:\n"
 "  @G--" GTEST_FLAG_PREFIX_ "list_tests@D\n"
 "      List the names of all tests instead of running them. The name of\n"
 "      TEST(Foo, Bar) is \"Foo.Bar\".\n"
 "  @G--" GTEST_FLAG_PREFIX_ "filter=@YPOSTIVE_PATTERNS"
     "[@G-@YNEGATIVE_PATTERNS]@D\n"
 "      Run only the tests whose name matches one of the positive patterns but\n"
 "      none of the negative patterns. '?' matches any single character; '*'\n"
 "      matches any substring; ':' separates two patterns.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "also_run_disabled_tests@D\n"
 "      Run all disabled tests too.\n"
 "\n"
 "Test Execution:\n"
 "  @G--" GTEST_FLAG_PREFIX_ "repeat=@Y[COUNT]@D\n"
 "      Run the tests repeatedly; use a negative count to repeat forever.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "shuffle@D\n"
 "      Randomize tests' orders on every iteration.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "random_seed=@Y[NUMBER]@D\n"
 "      Random number seed to use for shuffling test orders (between 1 and\n"
 "      99999, or 0 to use a seed based on the current time).\n"
 "\n"
 "Test Output:\n"
 "  @G--" GTEST_FLAG_PREFIX_ "color=@Y(@Gyes@Y|@Gno@Y|@Gauto@Y)@D\n"
 "      Enable/disable colored output. The default is @Gauto@D.\n"
 "  -@G-" GTEST_FLAG_PREFIX_ "print_time=0@D\n"
 "      Don't print the elapsed time of each test.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "output=@Y(@Gjson@Y|@Gxml@Y)[@G:@YDIRECTORY_PATH@G"
     GTEST_PATH_SEP_ "@Y|@G:@YFILE_PATH]@D\n"
 "      Generate a JSON or XML report in the given directory or with the given\n"
 "      file name. @YFILE_PATH@D defaults to @Gtest_detail.xml@D.\n"
 # if GTEST_CAN_STREAM_RESULTS_
 "  @G--" GTEST_FLAG_PREFIX_ "stream_result_to=@YHOST@G:@YPORT@D\n"
 "      Stream test results to the given server.\n"
 # endif  // GTEST_CAN_STREAM_RESULTS_
 "\n"
 "Assertion Behavior:\n"
 # if GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
 "  @G--" GTEST_FLAG_PREFIX_ "death_test_style=@Y(@Gfast@Y|@Gthreadsafe@Y)@D\n"
 "      Set the default death test style.\n"
 # endif  // GTEST_HAS_DEATH_TEST && !GTEST_OS_WINDOWS
 "  @G--" GTEST_FLAG_PREFIX_ "break_on_failure@D\n"
 "      Turn assertion failures into debugger break-points.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "throw_on_failure@D\n"
 "      Turn assertion failures into C++ exceptions for use by an external\n"
 "      test framework.\n"
 "  @G--" GTEST_FLAG_PREFIX_ "catch_exceptions=0@D\n"
 "      Do not report exceptions as test failures. Instead, allow them\n"
 "      to crash the program or throw a pop-up (on Windows).\n"
 "\n"
 "Except for @G--" GTEST_FLAG_PREFIX_ "list_tests@D, you can alternatively set "
     "the corresponding\n"
 "environment variable of a flag (all letters in upper-case). For example, to\n"
 "disable colored text output, you can either specify @G--" GTEST_FLAG_PREFIX_
     "color=no@D or set\n"
 "the @G" GTEST_FLAG_PREFIX_UPPER_ "COLOR@D environment variable to @Gno@D.\n"
 "\n"
 "For more information, please read the " GTEST_NAME_ " documentation at\n"
 "@G" GTEST_PROJECT_URL_ "@D. If you find a bug in " GTEST_NAME_ "\n"
 "(not one in your own code or tests), please report it to\n"
 "@G<" GTEST_DEV_EMAIL_ ">@D.\n";
 
 static bool ParseGoogleTestFlag(const char* const arg) {
   return ParseBoolFlag(arg, kAlsoRunDisabledTestsFlag,
                        &GTEST_FLAG(also_run_disabled_tests)) ||
       ParseBoolFlag(arg, kBreakOnFailureFlag,
                     &GTEST_FLAG(break_on_failure)) ||
       ParseBoolFlag(arg, kCatchExceptionsFlag,
                     &GTEST_FLAG(catch_exceptions)) ||
       ParseStringFlag(arg, kColorFlag, &GTEST_FLAG(color)) ||
       ParseStringFlag(arg, kDeathTestStyleFlag,
                       &GTEST_FLAG(death_test_style)) ||
       ParseBoolFlag(arg, kDeathTestUseFork,
                     &GTEST_FLAG(death_test_use_fork)) ||
       ParseStringFlag(arg, kFilterFlag, &GTEST_FLAG(filter)) ||
       ParseStringFlag(arg, kInternalRunDeathTestFlag,
                       &GTEST_FLAG(internal_run_death_test)) ||
       ParseBoolFlag(arg, kListTestsFlag, &GTEST_FLAG(list_tests)) ||
       ParseStringFlag(arg, kOutputFlag, &GTEST_FLAG(output)) ||
       ParseBoolFlag(arg, kPrintTimeFlag, &GTEST_FLAG(print_time)) ||
       ParseBoolFlag(arg, kPrintUTF8Flag, &GTEST_FLAG(print_utf8)) ||
       ParseInt32Flag(arg, kRandomSeedFlag, &GTEST_FLAG(random_seed)) ||
       ParseInt32Flag(arg, kRepeatFlag, &GTEST_FLAG(repeat)) ||
       ParseBoolFlag(arg, kShuffleFlag, &GTEST_FLAG(shuffle)) ||
       ParseInt32Flag(arg, kStackTraceDepthFlag,
                      &GTEST_FLAG(stack_trace_depth)) ||
       ParseStringFlag(arg, kStreamResultToFlag,
                       &GTEST_FLAG(stream_result_to)) ||
       ParseBoolFlag(arg, kThrowOnFailureFlag,
                     &GTEST_FLAG(throw_on_failure));
 }
 
 #if GTEST_USE_OWN_FLAGFILE_FLAG_
 static void LoadFlagsFromFile(const std::string& path) {
   FILE* flagfile = posix::FOpen(path.c_str(), "r");
   if (!flagfile) {
     GTEST_LOG_(FATAL) << "Unable to open file \"" << GTEST_FLAG(flagfile)
                       << "\"";
   }
   std::string contents(ReadEntireFile(flagfile));
   posix::FClose(flagfile);
   std::vector<std::string> lines;
   SplitString(contents, '\n', &lines);
   for (size_t i = 0; i < lines.size(); ++i) {
     if (lines[i].empty())
       continue;
     if (!ParseGoogleTestFlag(lines[i].c_str()))
       g_help_flag = true;
   }
 }
 #endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
 
 // Parses the command line for Google Test flags, without initializing
 // other parts of Google Test.  The type parameter CharType can be
 // instantiated to either char or wchar_t.
 template <typename CharType>
 void ParseGoogleTestFlagsOnlyImpl(int* argc, CharType** argv) {
   for (int i = 1; i < *argc; i++) {
     const std::string arg_string = StreamableToString(argv[i]);
     const char* const arg = arg_string.c_str();
 
     using internal::ParseBoolFlag;
     using internal::ParseInt32Flag;
     using internal::ParseStringFlag;
 
     bool remove_flag = false;
     if (ParseGoogleTestFlag(arg)) {
       remove_flag = true;
 #if GTEST_USE_OWN_FLAGFILE_FLAG_
     } else if (ParseStringFlag(arg, kFlagfileFlag, &GTEST_FLAG(flagfile))) {
       LoadFlagsFromFile(GTEST_FLAG(flagfile));
       remove_flag = true;
 #endif  // GTEST_USE_OWN_FLAGFILE_FLAG_
     } else if (arg_string == "--help" || arg_string == "-h" ||
                arg_string == "-?" || arg_string == "/?" ||
                HasGoogleTestFlagPrefix(arg)) {
       // Both help flag and unrecognized Google Test flags (excluding
       // internal ones) trigger help display.
       g_help_flag = true;
     }
 
     if (remove_flag) {
       // Shift the remainder of the argv list left by one.  Note
       // that argv has (*argc + 1) elements, the last one always being
       // NULL.  The following loop moves the trailing NULL element as
       // well.
       for (int j = i; j != *argc; j++) {
         argv[j] = argv[j + 1];
       }
 
       // Decrements the argument count.
       (*argc)--;
 
       // We also need to decrement the iterator as we just removed
       // an element.
       i--;
     }
   }
 
   if (g_help_flag) {
     // We print the help here instead of in RUN_ALL_TESTS(), as the
     // latter may not be called at all if the user is using Google
     // Test with another testing framework.
     PrintColorEncoded(kColorEncodedHelpMessage);
   }
 }
 
 // Parses the command line for Google Test flags, without initializing
 // other parts of Google Test.
 void ParseGoogleTestFlagsOnly(int* argc, char** argv) {
   ParseGoogleTestFlagsOnlyImpl(argc, argv);
 
   // Fix the value of *_NSGetArgc() on macOS, but if and only if
   // *_NSGetArgv() == argv
   // Only applicable to char** version of argv
 #if GTEST_OS_MAC
 #ifndef GTEST_OS_IOS
   if (*_NSGetArgv() == argv) {
     *_NSGetArgc() = *argc;
   }
 #endif
 #endif
 }
 void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv) {
   ParseGoogleTestFlagsOnlyImpl(argc, argv);
 }
 
 // The internal implementation of InitGoogleTest().
 //
 // The type parameter CharType can be instantiated to either char or
 // wchar_t.
 template <typename CharType>
 void InitGoogleTestImpl(int* argc, CharType** argv) {
   // We don't want to run the initialization code twice.
   if (GTestIsInitialized()) return;
 
   if (*argc <= 0) return;
 
   g_argvs.clear();
   for (int i = 0; i != *argc; i++) {
     g_argvs.push_back(StreamableToString(argv[i]));
   }
 
 #if GTEST_HAS_ABSL
   absl::InitializeSymbolizer(g_argvs[0].c_str());
 #endif  // GTEST_HAS_ABSL
 
   ParseGoogleTestFlagsOnly(argc, argv);
   GetUnitTestImpl()->PostFlagParsingInit();
 }
 
 }  // namespace internal
 
 // Initializes Google Test.  This must be called before calling
 // RUN_ALL_TESTS().  In particular, it parses a command line for the
 // flags that Google Test recognizes.  Whenever a Google Test flag is
 // seen, it is removed from argv, and *argc is decremented.
 //
 // No value is returned.  Instead, the Google Test flag variables are
 // updated.
 //
 // Calling the function for the second time has no user-visible effect.
 void InitGoogleTest(int* argc, char** argv) {
 #if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
 #else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   internal::InitGoogleTestImpl(argc, argv);
 #endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
 }
 
 // This overloaded version can be used in Windows programs compiled in
 // UNICODE mode.
 void InitGoogleTest(int* argc, wchar_t** argv) {
 #if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(argc, argv);
 #else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   internal::InitGoogleTestImpl(argc, argv);
 #endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
 }
 
 // This overloaded version can be used on Arduino/embedded platforms where
 // there is no argc/argv.
 void InitGoogleTest() {
   // Since Arduino doesn't have a command line, fake out the argc/argv arguments
   int argc = 1;
   const auto arg0 = "dummy";
   char* argv0 = const_cast<char*>(arg0);
   char** argv = &argv0;
 
 #if defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_(&argc, argv);
 #else  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
   internal::InitGoogleTestImpl(&argc, argv);
 #endif  // defined(GTEST_CUSTOM_INIT_GOOGLE_TEST_FUNCTION_)
 }
 
 std::string TempDir() {
 #if defined(GTEST_CUSTOM_TEMPDIR_FUNCTION_)
   return GTEST_CUSTOM_TEMPDIR_FUNCTION_();
 #endif
 
 #if GTEST_OS_WINDOWS_MOBILE
   return "\\temp\\";
 #elif GTEST_OS_WINDOWS
   const char* temp_dir = internal::posix::GetEnv("TEMP");
   if (temp_dir == nullptr || temp_dir[0] == '\0')
     return "\\temp\\";
   else if (temp_dir[strlen(temp_dir) - 1] == '\\')
     return temp_dir;
   else
     return std::string(temp_dir) + "\\";
 #elif GTEST_OS_LINUX_ANDROID
   const char* temp_dir = internal::posix::GetEnv("TEST_TMPDIR");
   if (temp_dir == nullptr || temp_dir[0] == '\0')
     return "/data/local/tmp/";
   else
     return temp_dir;
 #else
   return "/tmp/";
 #endif  // GTEST_OS_WINDOWS_MOBILE
 }
 
 // Class ScopedTrace
 
 // Pushes the given source file location and message onto a per-thread
 // trace stack maintained by Google Test.
 void ScopedTrace::PushTrace(const char* file, int line, std::string message) {
   internal::TraceInfo trace;
   trace.file = file;
   trace.line = line;
   trace.message.swap(message);
 
   UnitTest::GetInstance()->PushGTestTrace(trace);
 }
 
 // Pops the info pushed by the c'tor.
 ScopedTrace::~ScopedTrace()
     GTEST_LOCK_EXCLUDED_(&UnitTest::mutex_) {
   UnitTest::GetInstance()->PopGTestTrace();
 }
 
 }  // namespace testing