gtest-internal-inl.h

Go to the documentation of this file.

// 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.

// Utility functions and classes used by the Google C++ testing framework.
//
// Author: wan@google.com (Zhanyong Wan)
//
// This file contains purely Google Test's internal implementation.  Please
// DO NOT #INCLUDE IT IN A USER PROGRAM.

#ifndef GTEST_SRC_GTEST_INTERNAL_INL_H_
#define GTEST_SRC_GTEST_INTERNAL_INL_H_

// GTEST_IMPLEMENTATION_ is defined to 1 iff the current translation unit is
// part of Google Test's implementation; otherwise it's undefined.
#if !GTEST_IMPLEMENTATION_
// If this file is included from the user's code, just say no.
# error "gtest-internal-inl.h is part of Google Test's internal implementation."
# error "It must not be included except by Google Test itself."
#endif  // GTEST_IMPLEMENTATION_

#ifndef _WIN32_WCE
# include <errno.h>
#endif  // !_WIN32_WCE
#include <stddef.h>
#include <stdlib.h>  // For strtoll/_strtoul64/malloc/free.
#include <string.h>  // For memmove.

#include <algorithm>
#include <string>
#include <vector>

#include "gtest/internal/gtest-port.h"

#if GTEST_CAN_STREAM_RESULTS_
# include <arpa/inet.h>  // NOLINT
# include <netdb.h>  // NOLINT
#endif

#if GTEST_OS_WINDOWS
# include <windows.h>  // NOLINT
#endif  // GTEST_OS_WINDOWS

#include "gtest/gtest.h"  // NOLINT
#include "gtest/gtest-spi.h"

namespace testing {

// Declares the flags.
//
// We don't want the users to modify this flag in the code, but want
// Google Test's own unit tests to be able to access it. Therefore we
// declare it here as opposed to in gtest.h.
GTEST_DECLARE_bool_(death_test_use_fork);

namespace internal {

// The value of GetTestTypeId() as seen from within the Google Test
// library.  This is solely for testing GetTestTypeId().
GTEST_API_ extern const TypeId kTestTypeIdInGoogleTest;

// Names of the flags (needed for parsing Google Test flags).
const char kAlsoRunDisabledTestsFlag[] = "also_run_disabled_tests";
const char kBreakOnFailureFlag[] = "break_on_failure";
const char kCatchExceptionsFlag[] = "catch_exceptions";
const char kColorFlag[] = "color";
const char kFilterFlag[] = "filter";
const char kListTestsFlag[] = "list_tests";
const char kOutputFlag[] = "output";
const char kPrintTimeFlag[] = "print_time";
const char kRandomSeedFlag[] = "random_seed";
const char kRepeatFlag[] = "repeat";
const char kShuffleFlag[] = "shuffle";
const char kStackTraceDepthFlag[] = "stack_trace_depth";
const char kStreamResultToFlag[] = "stream_result_to";
const char kThrowOnFailureFlag[] = "throw_on_failure";
const char kFlagfileFlag[] = "flagfile";

// A valid random seed must be in [1, kMaxRandomSeed].
const int kMaxRandomSeed = 99999;

// g_help_flag is true iff the --help flag or an equivalent form is
// specified on the command line.
GTEST_API_ extern bool g_help_flag;

// Returns the current time in milliseconds.
GTEST_API_ TimeInMillis GetTimeInMillis();

// Returns true iff Google Test should use colors in the output.
GTEST_API_ bool ShouldUseColor(bool stdout_is_tty);

// Formats the given time in milliseconds as seconds.
GTEST_API_ std::string FormatTimeInMillisAsSeconds(TimeInMillis ms);

// Converts the given time in milliseconds to a date string in the ISO 8601
// format, without the timezone information.  N.B.: due to the use the
// non-reentrant localtime() function, this function is not thread safe.  Do
// not use it in any code that can be called from multiple threads.
GTEST_API_ std::string FormatEpochTimeInMillisAsIso8601(TimeInMillis ms);

// Parses a string for an Int32 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.
GTEST_API_ bool ParseInt32Flag(
    const char* str, const char* flag, Int32* value);

// Returns a random seed in range [1, kMaxRandomSeed] based on the
// given --gtest_random_seed flag value.
inline int GetRandomSeedFromFlag(Int32 random_seed_flag) {
  const unsigned int raw_seed = (random_seed_flag == 0) ?
      static_cast<unsigned int>(GetTimeInMillis()) :
      static_cast<unsigned int>(random_seed_flag);

  // Normalizes the actual seed to range [1, kMaxRandomSeed] such that
  // it's easy to type.
  const int normalized_seed =
      static_cast<int>((raw_seed - 1U) %
                       static_cast<unsigned int>(kMaxRandomSeed)) + 1;
  return normalized_seed;
}

// Returns the first valid random seed after 'seed'.  The behavior is
// undefined if 'seed' is invalid.  The seed after kMaxRandomSeed is
// considered to be 1.
inline int GetNextRandomSeed(int seed) {
  GTEST_CHECK_(1 <= seed && seed <= kMaxRandomSeed)
      << "Invalid random seed " << seed << " - must be in [1, "
      << kMaxRandomSeed << "].";
  const int next_seed = seed + 1;
  return (next_seed > kMaxRandomSeed) ? 1 : next_seed;
}

// This class saves the values of all Google Test flags in its c'tor, and
// restores them in its d'tor.
class GTestFlagSaver {
 public:
  // The c'tor.
  GTestFlagSaver() {
    also_run_disabled_tests_ = GTEST_FLAG(also_run_disabled_tests);
    break_on_failure_ = GTEST_FLAG(break_on_failure);
    catch_exceptions_ = GTEST_FLAG(catch_exceptions);
    color_ = GTEST_FLAG(color);
    death_test_style_ = GTEST_FLAG(death_test_style);
    death_test_use_fork_ = GTEST_FLAG(death_test_use_fork);
    filter_ = GTEST_FLAG(filter);
    internal_run_death_test_ = GTEST_FLAG(internal_run_death_test);
    list_tests_ = GTEST_FLAG(list_tests);
    output_ = GTEST_FLAG(output);
    print_time_ = GTEST_FLAG(print_time);
    random_seed_ = GTEST_FLAG(random_seed);
    repeat_ = GTEST_FLAG(repeat);
    shuffle_ = GTEST_FLAG(shuffle);
    stack_trace_depth_ = GTEST_FLAG(stack_trace_depth);
    stream_result_to_ = GTEST_FLAG(stream_result_to);
    throw_on_failure_ = GTEST_FLAG(throw_on_failure);
  }

  // The d'tor is not virtual.  DO NOT INHERIT FROM THIS CLASS.
  ~GTestFlagSaver() {
    GTEST_FLAG(also_run_disabled_tests) = also_run_disabled_tests_;
    GTEST_FLAG(break_on_failure) = break_on_failure_;
    GTEST_FLAG(catch_exceptions) = catch_exceptions_;
    GTEST_FLAG(color) = color_;
    GTEST_FLAG(death_test_style) = death_test_style_;
    GTEST_FLAG(death_test_use_fork) = death_test_use_fork_;
    GTEST_FLAG(filter) = filter_;
    GTEST_FLAG(internal_run_death_test) = internal_run_death_test_;
    GTEST_FLAG(list_tests) = list_tests_;
    GTEST_FLAG(output) = output_;
    GTEST_FLAG(print_time) = print_time_;
    GTEST_FLAG(random_seed) = random_seed_;
    GTEST_FLAG(repeat) = repeat_;
    GTEST_FLAG(shuffle) = shuffle_;
    GTEST_FLAG(stack_trace_depth) = stack_trace_depth_;
    GTEST_FLAG(stream_result_to) = stream_result_to_;
    GTEST_FLAG(throw_on_failure) = throw_on_failure_;
  }

 private:
  // Fields for saving the original values of flags.
  bool also_run_disabled_tests_;
  bool break_on_failure_;
  bool catch_exceptions_;
  std::string color_;
  std::string death_test_style_;
  bool death_test_use_fork_;
  std::string filter_;
  std::string internal_run_death_test_;
  bool list_tests_;
  std::string output_;
  bool print_time_;
  internal::Int32 random_seed_;
  internal::Int32 repeat_;
  bool shuffle_;
  internal::Int32 stack_trace_depth_;
  std::string stream_result_to_;
  bool throw_on_failure_;
} GTEST_ATTRIBUTE_UNUSED_;

// Converts a Unicode code point to a narrow string in UTF-8 encoding.
// code_point parameter is of type UInt32 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)".
GTEST_API_ std::string CodePointToUtf8(UInt32 code_point);

// 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, Symbian OS)
//   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.
GTEST_API_ std::string WideStringToUtf8(const wchar_t* str, int num_chars);

// 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();

// Checks whether sharding is enabled by examining the relevant
// environment variable values. If the variables are present,
// but inconsistent (e.g., 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.
GTEST_API_ bool ShouldShard(const char* total_shards_str,
                            const char* shard_index_str,
                            bool in_subprocess_for_death_test);

// 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
// and aborts.
GTEST_API_ Int32 Int32FromEnvOrDie(const char* env_var, Int32 default_val);

// Given the total number of shards, the shard index, and the test id,
// returns true iff 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.
GTEST_API_ bool ShouldRunTestOnShard(
    int total_shards, int shard_index, int test_id);

// STL container utilities.

// Returns the number of elements in the given container that satisfy
// the given predicate.
template <class Container, typename Predicate>
inline int CountIf(const Container& c, Predicate predicate) {
  // Implemented as an explicit loop since std::count_if() in libCstd on
  // Solaris has a non-standard signature.
  int count = 0;
  for (typename Container::const_iterator it = c.begin(); it != c.end(); ++it) {
    if (predicate(*it))
      ++count;
  }
  return count;
}

// Applies a function/functor to each element in the container.
template <class Container, typename Functor>
void ForEach(const Container& c, Functor functor) {
  std::for_each(c.begin(), c.end(), functor);
}

// Returns the i-th element of the vector, or default_value if i is not
// in range [0, v.size()).
template <typename E>
inline E GetElementOr(const std::vector<E>& v, int i, E default_value) {
  return (i < 0 || i >= static_cast<int>(v.size())) ? default_value : v[i];
}

// Performs an in-place shuffle of a range of the vector's elements.
// 'begin' and 'end' are element indices as an STL-style range;
// i.e. [begin, end) are shuffled, where 'end' == size() means to
// shuffle to the end of the vector.
template <typename E>
void ShuffleRange(internal::Random* random, int begin, int end,
                  std::vector<E>* v) {
  const int size = static_cast<int>(v->size());
  GTEST_CHECK_(0 <= begin && begin <= size)
      << "Invalid shuffle range start " << begin << ": must be in range [0, "
      << size << "].";
  GTEST_CHECK_(begin <= end && end <= size)
      << "Invalid shuffle range finish " << end << ": must be in range ["
      << begin << ", " << size << "].";

  // Fisher-Yates shuffle, from
  // http://en.wikipedia.org/wiki/Fisher-Yates_shuffle
  for (int range_width = end - begin; range_width >= 2; range_width--) {
    const int last_in_range = begin + range_width - 1;
    const int selected = begin + random->Generate(range_width);
    std::swap((*v)[selected], (*v)[last_in_range]);
  }
}

// Performs an in-place shuffle of the vector's elements.
template <typename E>
inline void Shuffle(internal::Random* random, std::vector<E>* v) {
  ShuffleRange(random, 0, static_cast<int>(v->size()), v);
}

// A function for deleting an object.  Handy for being used as a
// functor.
template <typename T>
static void Delete(T* x) {
  delete x;
}

// A predicate that checks the key of a TestProperty against a known key.
//
// TestPropertyKeyIs is copyable.
class TestPropertyKeyIs {
 public:
  // Constructor.
  //
  // TestPropertyKeyIs has NO default constructor.
  explicit TestPropertyKeyIs(const std::string& key) : key_(key) {}

  // Returns true iff the test name of test property matches on key_.
  bool operator()(const TestProperty& test_property) const {
    return test_property.key() == key_;
  }

 private:
  std::string key_;
};

// Class UnitTestOptions.
//
// This class contains functions for processing options the user
// specifies when running the tests.  It has only static members.
//
// In most cases, the user can specify an option using either an
// environment variable or a command line flag.  E.g. you can set the
// test filter using either GTEST_FILTER or --gtest_filter.  If both
// the variable and the flag are present, the latter overrides the
// former.
class GTEST_API_ UnitTestOptions {
 public:
  // Functions for processing the gtest_output flag.

  // Returns the output format, or "" for normal printed output.
  static std::string GetOutputFormat();

  // Returns the absolute path of the requested output file, or the
  // default (test_detail.xml in the original working directory) if
  // none was explicitly specified.
  static std::string GetAbsolutePathToOutputFile();

  // Functions for processing the gtest_filter flag.

  // Returns true iff 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.
  static bool PatternMatchesString(const char *pattern, const char *str);

  // Returns true iff the user-specified filter matches the test case
  // name and the test name.
  static bool FilterMatchesTest(const std::string &test_case_name,
                                const std::string &test_name);

#if GTEST_OS_WINDOWS
  // Function for supporting the gtest_catch_exception flag.

  // 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.
  static int GTestShouldProcessSEH(DWORD exception_code);
#endif  // GTEST_OS_WINDOWS

  // Returns true if "name" matches the ':' separated list of glob-style
  // filters in "filter".
  static bool MatchesFilter(const std::string& name, const char* filter);
};

// Returns the current application's name, removing directory path if that
// is present.  Used by UnitTestOptions::GetOutputFile.
GTEST_API_ FilePath GetCurrentExecutableName();

// The role interface for getting the OS stack trace as a string.
class OsStackTraceGetterInterface {
 public:
  OsStackTraceGetterInterface() {}
  virtual ~OsStackTraceGetterInterface() {}

  // Returns the current OS stack trace as an std::string.  Parameters:
  //
  //   max_depth  - the maximum number of stack frames to be included
  //                in the trace.
  //   skip_count - the number of top frames to be skipped; doesn't count
  //                against max_depth.
  virtual string CurrentStackTrace(int max_depth, int skip_count) = 0;

  // UponLeavingGTest() should be called immediately before Google Test calls
  // user code. It saves some information about the current stack that
  // CurrentStackTrace() will use to find and hide Google Test stack frames.
  virtual void UponLeavingGTest() = 0;

  // This string is inserted in place of stack frames that are part of
  // Google Test's implementation.
  static const char* const kElidedFramesMarker;

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetterInterface);
};

// A working implementation of the OsStackTraceGetterInterface interface.
class OsStackTraceGetter : public OsStackTraceGetterInterface {
 public:
  OsStackTraceGetter() {}

  virtual string CurrentStackTrace(int max_depth, int skip_count);
  virtual void UponLeavingGTest();

 private:
  GTEST_DISALLOW_COPY_AND_ASSIGN_(OsStackTraceGetter);
};

// Information about a Google Test trace point.
struct TraceInfo {
  const char* file;
  int line;
  std::string message;
};

// This is the default global test part result reporter used in UnitTestImpl.
// This class should only be used by UnitTestImpl.
class DefaultGlobalTestPartResultReporter
  : public TestPartResultReporterInterface {
 public:
  explicit DefaultGlobalTestPartResultReporter(UnitTestImpl* unit_test);
  // Implements the TestPartResultReporterInterface. Reports the test part
  // result in the current test.
  virtual void ReportTestPartResult(const TestPartResult& result);

 private:
  UnitTestImpl* const unit_test_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultGlobalTestPartResultReporter);
};

// This is the default per thread test part result reporter used in
// UnitTestImpl. This class should only be used by UnitTestImpl.
class DefaultPerThreadTestPartResultReporter
    : public TestPartResultReporterInterface {
 public:
  explicit DefaultPerThreadTestPartResultReporter(UnitTestImpl* unit_test);
  // Implements the TestPartResultReporterInterface. The implementation just
  // delegates to the current global test part result reporter of *unit_test_.
  virtual void ReportTestPartResult(const TestPartResult& result);

 private:
  UnitTestImpl* const unit_test_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(DefaultPerThreadTestPartResultReporter);
};

// The private implementation of the UnitTest class.  We don't protect
// the methods under a mutex, as this class is not accessible by a
// user and the UnitTest class that delegates work to this class does
// proper locking.
class GTEST_API_ UnitTestImpl {
 public:
  explicit UnitTestImpl(UnitTest* parent);
  virtual ~UnitTestImpl();

  // There are two different ways to register your own TestPartResultReporter.
  // You can register your own repoter to listen either only for test results
  // from the current thread or for results from all threads.
  // By default, each per-thread test result repoter just passes a new
  // TestPartResult to the global test result reporter, which registers the
  // test part result for the currently running test.

  // Returns the global test part result reporter.
  TestPartResultReporterInterface* GetGlobalTestPartResultReporter();

  // Sets the global test part result reporter.
  void SetGlobalTestPartResultReporter(
      TestPartResultReporterInterface* reporter);

  // Returns the test part result reporter for the current thread.
  TestPartResultReporterInterface* GetTestPartResultReporterForCurrentThread();

  // Sets the test part result reporter for the current thread.
  void SetTestPartResultReporterForCurrentThread(
      TestPartResultReporterInterface* reporter);

  // Gets the number of successful test cases.
  int successful_test_case_count() const;

  // Gets the number of failed test cases.
  int failed_test_case_count() const;

  // Gets the number of all test cases.
  int total_test_case_count() const;

  // Gets the number of all test cases that contain at least one test
  // that should run.
  int test_case_to_run_count() const;

  // Gets the number of successful tests.
  int successful_test_count() const;

  // Gets the number of failed tests.
  int failed_test_count() const;

  // Gets the number of disabled tests that will be reported in the XML report.
  int reportable_disabled_test_count() const;

  // Gets the number of disabled tests.
  int disabled_test_count() const;

  // Gets the number of tests to be printed in the XML report.
  int reportable_test_count() const;

  // Gets the number of all tests.
  int total_test_count() const;

  // Gets the number of tests that should run.
  int test_to_run_count() const;

  // Gets the time of the test program start, in ms from the start of the
  // UNIX epoch.
  TimeInMillis start_timestamp() const { return start_timestamp_; }

  // Gets the elapsed time, in milliseconds.
  TimeInMillis elapsed_time() const { return elapsed_time_; }

  // Returns true iff the unit test passed (i.e. all test cases passed).
  bool Passed() const { return !Failed(); }

  // Returns true iff the unit test failed (i.e. some test case failed
  // or something outside of all tests failed).
  bool Failed() const {
    return failed_test_case_count() > 0 || ad_hoc_test_result()->Failed();
  }

  // Gets the i-th test case among all the test cases. i can range from 0 to
  // total_test_case_count() - 1. If i is not in that range, returns NULL.
  const TestCase* GetTestCase(int i) const {
    const int index = GetElementOr(test_case_indices_, i, -1);
    return index < 0 ? NULL : test_cases_[i];
  }

  // Gets the i-th test case among all the test cases. i can range from 0 to
  // total_test_case_count() - 1. If i is not in that range, returns NULL.
  TestCase* GetMutableTestCase(int i) {
    const int index = GetElementOr(test_case_indices_, i, -1);
    return index < 0 ? NULL : test_cases_[index];
  }

  // Provides access to the event listener list.
  TestEventListeners* listeners() { return &listeners_; }

  // Returns the TestResult for the test that's currently running, or
  // the TestResult for the ad hoc test if no test is running.
  TestResult* current_test_result();

  // Returns the TestResult for the ad hoc test.
  const TestResult* ad_hoc_test_result() const { return &ad_hoc_test_result_; }

  // 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 set_os_stack_trace_getter(OsStackTraceGetterInterface* 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* os_stack_trace_getter();

  // 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 CurrentOsStackTraceExceptTop(int skip_count) GTEST_NO_INLINE_;

  // Finds and returns a TestCase with the given name.  If one doesn't
  // exist, creates one and returns it.
  //
  // Arguments:
  //
  //   test_case_name: name of the test case
  //   type_param:     the name of the test's type parameter, or NULL if
  //                   this is not a typed or a type-parameterized test.
  //   set_up_tc:      pointer to the function that sets up the test case
  //   tear_down_tc:   pointer to the function that tears down the test case
  TestCase* GetTestCase(const char* test_case_name,
                        const char* type_param,
                        Test::SetUpTestCaseFunc set_up_tc,
                        Test::TearDownTestCaseFunc tear_down_tc);

  // Adds a TestInfo to the unit test.
  //
  // Arguments:
  //
  //   set_up_tc:    pointer to the function that sets up the test case
  //   tear_down_tc: pointer to the function that tears down the test case
  //   test_info:    the TestInfo object
  void AddTestInfo(Test::SetUpTestCaseFunc set_up_tc,
                   Test::TearDownTestCaseFunc tear_down_tc,
                   TestInfo* test_info) {
    // In order to support thread-safe death tests, we need to
    // remember the original working directory when the test program
    // was first invoked.  We cannot do this in RUN_ALL_TESTS(), as
    // the user may have changed the current directory before calling
    // RUN_ALL_TESTS().  Therefore we capture the current directory in
    // AddTestInfo(), which is called to register a TEST or TEST_F
    // before main() is reached.
    if (original_working_dir_.IsEmpty()) {
      original_working_dir_.Set(FilePath::GetCurrentDir());
      GTEST_CHECK_(!original_working_dir_.IsEmpty())
          << "Failed to get the current working directory.";
    }

    GetTestCase(test_info->test_case_name(),
                test_info->type_param(),
                set_up_tc,
                tear_down_tc)->AddTestInfo(test_info);
  }

#if GTEST_HAS_PARAM_TEST
  // Returns ParameterizedTestCaseRegistry object used to keep track of
  // value-parameterized tests and instantiate and register them.
  internal::ParameterizedTestCaseRegistry& parameterized_test_registry() {
    return parameterized_test_registry_;
  }
#endif  // GTEST_HAS_PARAM_TEST

  // Sets the TestCase object for the test that's currently running.
  void set_current_test_case(TestCase* a_current_test_case) {
    current_test_case_ = a_current_test_case;
  }

  // Sets the TestInfo object for the test that's currently running.  If
  // current_test_info is NULL, the assertion results will be stored in
  // ad_hoc_test_result_.
  void set_current_test_info(TestInfo* a_current_test_info) {
    current_test_info_ = a_current_test_info;
  }

  // Registers all parameterized tests defined using TEST_P and
  // INSTANTIATE_TEST_CASE_P, creating regular tests for each test/parameter
  // combination. This method can be called more then once; it has guards
  // protecting from registering the tests more then once.  If
  // value-parameterized tests are disabled, RegisterParameterizedTests is
  // present but does nothing.
  void RegisterParameterizedTests();

  // 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, this test is considered to be failed, but
  // the rest of the tests will still be run.
  bool RunAllTests();

  // Clears the results of all tests, except the ad hoc tests.
  void ClearNonAdHocTestResult() {
    ForEach(test_cases_, TestCase::ClearTestCaseResult);
  }

  // Clears the results of ad-hoc test assertions.
  void ClearAdHocTestResult() {
    ad_hoc_test_result_.Clear();
  }

  // Adds a TestProperty to the current TestResult object when invoked in a
  // context of a test or a test case, or to the global property set. If the
  // result already contains a property with the same key, the value will be
  // updated.
  void RecordProperty(const TestProperty& test_property);

  enum ReactionToSharding {
    HONOR_SHARDING_PROTOCOL,
    IGNORE_SHARDING_PROTOCOL
  };

  // Matches the full name of each test against the user-specified
  // filter to decide whether the test should run, then records the
  // result in each TestCase and TestInfo object.
  // If shard_tests == HONOR_SHARDING_PROTOCOL, further filters tests
  // based on sharding variables in the environment.
  // Returns the number of tests that should run.
  int FilterTests(ReactionToSharding shard_tests);

  // Prints the names of the tests matching the user-specified filter flag.
  void ListTestsMatchingFilter();

  const TestCase* current_test_case() const { return current_test_case_; }
  TestInfo* current_test_info() { return current_test_info_; }
  const TestInfo* current_test_info() const { return current_test_info_; }

  // Returns the vector of environments that need to be set-up/torn-down
  // before/after the tests are run.
  std::vector<Environment*>& environments() { return environments_; }

  // Getters for the per-thread Google Test trace stack.
  std::vector<TraceInfo>& gtest_trace_stack() {
    return *(gtest_trace_stack_.pointer());
  }
  const std::vector<TraceInfo>& gtest_trace_stack() const {
    return gtest_trace_stack_.get();
  }

#if GTEST_HAS_DEATH_TEST
  void InitDeathTestSubprocessControlInfo() {
    internal_run_death_test_flag_.reset(ParseInternalRunDeathTestFlag());
  }
  // Returns a pointer to the parsed --gtest_internal_run_death_test
  // flag, or NULL if that flag was not specified.
  // This information is useful only in a death test child process.
  // Must not be called before a call to InitGoogleTest.
  const InternalRunDeathTestFlag* internal_run_death_test_flag() const {
    return internal_run_death_test_flag_.get();
  }

  // Returns a pointer to the current death test factory.
  internal::DeathTestFactory* death_test_factory() {
    return death_test_factory_.get();
  }

  void SuppressTestEventsIfInSubprocess();

  friend class ReplaceDeathTestFactory;
#endif  // GTEST_HAS_DEATH_TEST

  // Initializes the event listener performing XML output as specified by
  // UnitTestOptions. Must not be called before InitGoogleTest.
  void ConfigureXmlOutput();

#if GTEST_CAN_STREAM_RESULTS_
  // Initializes the event listener for streaming test results to a socket.
  // Must not be called before InitGoogleTest.
  void ConfigureStreamingOutput();
#endif

  // 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 PostFlagParsingInit();

  // Gets the random seed used at the start of the current test iteration.
  int random_seed() const { return random_seed_; }

  // Gets the random number generator.
  internal::Random* random() { return &random_; }

  // Shuffles all test cases, and the tests within each test case,
  // making sure that death tests are still run first.
  void ShuffleTests();

  // Restores the test cases and tests to their order before the first shuffle.
  void UnshuffleTests();

  // Returns the value of GTEST_FLAG(catch_exceptions) at the moment
  // UnitTest::Run() starts.
  bool catch_exceptions() const { return catch_exceptions_; }

 private:
  friend class ::testing::UnitTest;

  // Used by UnitTest::Run() to capture the state of
  // GTEST_FLAG(catch_exceptions) at the moment it starts.
  void set_catch_exceptions(bool value) { catch_exceptions_ = value; }

  // The UnitTest object that owns this implementation object.
  UnitTest* const parent_;

  // The working directory when the first TEST() or TEST_F() was
  // executed.
  internal::FilePath original_working_dir_;

  // The default test part result reporters.
  DefaultGlobalTestPartResultReporter default_global_test_part_result_reporter_;
  DefaultPerThreadTestPartResultReporter
      default_per_thread_test_part_result_reporter_;

  // Points to (but doesn't own) the global test part result reporter.
  TestPartResultReporterInterface* global_test_part_result_repoter_;

  // Protects read and write access to global_test_part_result_reporter_.
  internal::Mutex global_test_part_result_reporter_mutex_;

  // Points to (but doesn't own) the per-thread test part result reporter.
  internal::ThreadLocal<TestPartResultReporterInterface*>
      per_thread_test_part_result_reporter_;

  // The vector of environments that need to be set-up/torn-down
  // before/after the tests are run.
  std::vector<Environment*> environments_;

  // The vector of TestCases in their original order.  It owns the
  // elements in the vector.
  std::vector<TestCase*> test_cases_;

  // Provides a level of indirection for the test case list to allow
  // easy shuffling and restoring the test case order.  The i-th
  // element of this vector is the index of the i-th test case in the
  // shuffled order.
  std::vector<int> test_case_indices_;

#if GTEST_HAS_PARAM_TEST
  // ParameterizedTestRegistry object used to register value-parameterized
  // tests.
  internal::ParameterizedTestCaseRegistry parameterized_test_registry_;

  // Indicates whether RegisterParameterizedTests() has been called already.
  bool parameterized_tests_registered_;
#endif  // GTEST_HAS_PARAM_TEST

  // Index of the last death test case registered.  Initially -1.
  int last_death_test_case_;

  // This points to the TestCase for the currently running test.  It
  // changes as Google Test goes through one test case after another.
  // When no test is running, this is set to NULL and Google Test
  // stores assertion results in ad_hoc_test_result_.  Initially NULL.
  TestCase* current_test_case_;

  // This points to the TestInfo for the currently running test.  It
  // changes as Google Test goes through one test after another.  When
  // no test is running, this is set to NULL and Google Test stores
  // assertion results in ad_hoc_test_result_.  Initially NULL.
  TestInfo* current_test_info_;

  // Normally, a user only writes assertions inside a TEST or TEST_F,
  // or inside a function called by a TEST or TEST_F.  Since Google
  // Test keeps track of which test is current running, it can
  // associate such an assertion with the test it belongs to.
  //
  // If an assertion is encountered when no TEST or TEST_F is running,
  // Google Test attributes the assertion result to an imaginary "ad hoc"
  // test, and records the result in ad_hoc_test_result_.
  TestResult ad_hoc_test_result_;

  // The list of event listeners that can be used to track events inside
  // Google Test.
  TestEventListeners listeners_;

  // The OS stack trace getter.  Will be deleted when the UnitTest
  // object is destructed.  By default, an OsStackTraceGetter is used,
  // but the user can set this field to use a custom getter if that is
  // desired.
  OsStackTraceGetterInterface* os_stack_trace_getter_;

  // True iff PostFlagParsingInit() has been called.
  bool post_flag_parse_init_performed_;

  // The random number seed used at the beginning of the test run.
  int random_seed_;

  // Our random number generator.
  internal::Random random_;

  // The time of the test program start, in ms from the start of the
  // UNIX epoch.
  TimeInMillis start_timestamp_;

  // How long the test took to run, in milliseconds.
  TimeInMillis elapsed_time_;

#if GTEST_HAS_DEATH_TEST
  // The decomposed components of the gtest_internal_run_death_test flag,
  // parsed when RUN_ALL_TESTS is called.
  internal::scoped_ptr<InternalRunDeathTestFlag> internal_run_death_test_flag_;
  internal::scoped_ptr<internal::DeathTestFactory> death_test_factory_;
#endif  // GTEST_HAS_DEATH_TEST

  // A per-thread stack of traces created by the SCOPED_TRACE() macro.
  internal::ThreadLocal<std::vector<TraceInfo> > gtest_trace_stack_;

  // The value of GTEST_FLAG(catch_exceptions) at the moment RunAllTests()
  // starts.
  bool catch_exceptions_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(UnitTestImpl);
};  // class UnitTestImpl

// Convenience function for accessing the global UnitTest
// implementation object.
inline UnitTestImpl* GetUnitTestImpl() {
  return UnitTest::GetInstance()->impl();
}

#if GTEST_USES_SIMPLE_RE

// Internal helper functions for implementing the simple regular
// expression matcher.
GTEST_API_ bool IsInSet(char ch, const char* str);
GTEST_API_ bool IsAsciiDigit(char ch);
GTEST_API_ bool IsAsciiPunct(char ch);
GTEST_API_ bool IsRepeat(char ch);
GTEST_API_ bool IsAsciiWhiteSpace(char ch);
GTEST_API_ bool IsAsciiWordChar(char ch);
GTEST_API_ bool IsValidEscape(char ch);
GTEST_API_ bool AtomMatchesChar(bool escaped, char pattern, char ch);
GTEST_API_ bool ValidateRegex(const char* regex);
GTEST_API_ bool MatchRegexAtHead(const char* regex, const char* str);
GTEST_API_ bool MatchRepetitionAndRegexAtHead(
    bool escaped, char ch, char repeat, const char* regex, const char* str);
GTEST_API_ bool MatchRegexAnywhere(const char* regex, const char* str);

#endif  // GTEST_USES_SIMPLE_RE

// Parses the command line for Google Test flags, without initializing
// other parts of Google Test.
GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, char** argv);
GTEST_API_ void ParseGoogleTestFlagsOnly(int* argc, wchar_t** argv);

#if GTEST_HAS_DEATH_TEST

// Returns the message describing the last system error, regardless of the
// platform.
GTEST_API_ std::string GetLastErrnoDescription();

// Attempts to parse a string into a positive integer pointed to by the
// number parameter.  Returns true if that is possible.
// GTEST_HAS_DEATH_TEST implies that we have ::std::string, so we can use
// it here.
template <typename Integer>
bool ParseNaturalNumber(const ::std::string& str, Integer* number) {
  // Fail fast if the given string does not begin with a digit;
  // this bypasses strtoXXX's "optional leading whitespace and plus
  // or minus sign" semantics, which are undesirable here.
  if (str.empty() || !IsDigit(str[0])) {
    return false;
  }
  errno = 0;

  char* end;
  // BiggestConvertible is the largest integer type that system-provided
  // string-to-number conversion routines can return.

# if GTEST_OS_WINDOWS && !defined(__GNUC__)

  // MSVC and C++ Builder define __int64 instead of the standard long long.
  typedef unsigned __int64 BiggestConvertible;
  const BiggestConvertible parsed = _strtoui64(str.c_str(), &end, 10);

# else

  typedef unsigned long long BiggestConvertible;  // NOLINT
  const BiggestConvertible parsed = strtoull(str.c_str(), &end, 10);

# endif  // GTEST_OS_WINDOWS && !defined(__GNUC__)

  const bool parse_success = *end == '\0' && errno == 0;

  // TODO(vladl@google.com): Convert this to compile time assertion when it is
  // available.
  GTEST_CHECK_(sizeof(Integer) <= sizeof(parsed));

  const Integer result = static_cast<Integer>(parsed);
  if (parse_success && static_cast<BiggestConvertible>(result) == parsed) {
    *number = result;
    return true;
  }
  return false;
}
#endif  // GTEST_HAS_DEATH_TEST

// TestResult contains some private methods that should be hidden from
// Google Test user but are required for testing. This class allow our tests
// to access them.
//
// This class is supplied only for the purpose of testing Google Test's own
// constructs. Do not use it in user tests, either directly or indirectly.
class TestResultAccessor {
 public:
  static void RecordProperty(TestResult* test_result,
                             const std::string& xml_element,
                             const TestProperty& property) {
    test_result->RecordProperty(xml_element, property);
  }

  static void ClearTestPartResults(TestResult* test_result) {
    test_result->ClearTestPartResults();
  }

  static const std::vector<testing::TestPartResult>& test_part_results(
      const TestResult& test_result) {
    return test_result.test_part_results();
  }
};

#if GTEST_CAN_STREAM_RESULTS_

// Streams test results to the given port on the given host machine.
class GTEST_API_ StreamingListener : public EmptyTestEventListener {
 public:
  // Abstract base class for writing strings to a socket.
  class AbstractSocketWriter {
   public:
    virtual ~AbstractSocketWriter() {}

    // Sends a string to the socket.
    virtual void Send(const string& message) = 0;

    // Closes the socket.
    virtual void CloseConnection() {}

    // Sends a string and a newline to the socket.
    void SendLn(const string& message) {
      Send(message + "\n");
    }
  };

  // Concrete class for actually writing strings to a socket.
  class SocketWriter : public AbstractSocketWriter {
   public:
    SocketWriter(const string& host, const string& port)
        : sockfd_(-1), host_name_(host), port_num_(port) {
      MakeConnection();
    }

    virtual ~SocketWriter() {
      if (sockfd_ != -1)
        CloseConnection();
    }

    // Sends a string to the socket.
    virtual void Send(const string& message) {
      GTEST_CHECK_(sockfd_ != -1)
          << "Send() can be called only when there is a connection.";

      const int len = static_cast<int>(message.length());
      if (write(sockfd_, message.c_str(), len) != len) {
        GTEST_LOG_(WARNING)
            << "stream_result_to: failed to stream to "
            << host_name_ << ":" << port_num_;
      }
    }

   private:
    // Creates a client socket and connects to the server.
    void MakeConnection();

    // Closes the socket.
    void CloseConnection() {
      GTEST_CHECK_(sockfd_ != -1)
          << "CloseConnection() can be called only when there is a connection.";

      close(sockfd_);
      sockfd_ = -1;
    }

    int sockfd_;  // socket file descriptor
    const string host_name_;
    const string port_num_;

    GTEST_DISALLOW_COPY_AND_ASSIGN_(SocketWriter);
  };  // class SocketWriter

  // Escapes '=', '&', '%', and '\n' characters in str as "%xx".
  static string UrlEncode(const char* str);

  StreamingListener(const string& host, const string& port)
      : socket_writer_(new SocketWriter(host, port)) { Start(); }

  explicit StreamingListener(AbstractSocketWriter* socket_writer)
      : socket_writer_(socket_writer) { Start(); }

  void OnTestProgramStart(const UnitTest& /* unit_test */) {
    SendLn("event=TestProgramStart");
  }

  void OnTestProgramEnd(const UnitTest& unit_test) {
    // Note that Google Test current only report elapsed time for each
    // test iteration, not for the entire test program.
    SendLn("event=TestProgramEnd&passed=" + FormatBool(unit_test.Passed()));

    // Notify the streaming server to stop.
    socket_writer_->CloseConnection();
  }

  void OnTestIterationStart(const UnitTest& /* unit_test */, int iteration) {
    SendLn("event=TestIterationStart&iteration=" +
           StreamableToString(iteration));
  }

  void OnTestIterationEnd(const UnitTest& unit_test, int /* iteration */) {
    SendLn("event=TestIterationEnd&passed=" +
           FormatBool(unit_test.Passed()) + "&elapsed_time=" +
           StreamableToString(unit_test.elapsed_time()) + "ms");
  }

  void OnTestCaseStart(const TestCase& test_case) {
    SendLn(std::string("event=TestCaseStart&name=") + test_case.name());
  }

  void OnTestCaseEnd(const TestCase& test_case) {
    SendLn("event=TestCaseEnd&passed=" + FormatBool(test_case.Passed())
           + "&elapsed_time=" + StreamableToString(test_case.elapsed_time())
           + "ms");
  }

  void OnTestStart(const TestInfo& test_info) {
    SendLn(std::string("event=TestStart&name=") + test_info.name());
  }

  void OnTestEnd(const TestInfo& test_info) {
    SendLn("event=TestEnd&passed=" +
           FormatBool((test_info.result())->Passed()) +
           "&elapsed_time=" +
           StreamableToString((test_info.result())->elapsed_time()) + "ms");
  }

  void OnTestPartResult(const TestPartResult& test_part_result) {
    const char* file_name = test_part_result.file_name();
    if (file_name == NULL)
      file_name = "";
    SendLn("event=TestPartResult&file=" + UrlEncode(file_name) +
           "&line=" + StreamableToString(test_part_result.line_number()) +
           "&message=" + UrlEncode(test_part_result.message()));
  }

 private:
  // Sends the given message and a newline to the socket.
  void SendLn(const string& message) { socket_writer_->SendLn(message); }

  // Called at the start of streaming to notify the receiver what
  // protocol we are using.
  void Start() { SendLn("gtest_streaming_protocol_version=1.0"); }

  string FormatBool(bool value) { return value ? "1" : "0"; }

  const scoped_ptr<AbstractSocketWriter> socket_writer_;

  GTEST_DISALLOW_COPY_AND_ASSIGN_(StreamingListener);
};  // class StreamingListener

#endif  // GTEST_CAN_STREAM_RESULTS_

}  // namespace internal
}  // namespace testing

#endif  // GTEST_SRC_GTEST_INTERNAL_INL_H_