clang: fix `-Wsign-conversion` errors

Cast some values as their unsigned equivalents or `size_t` to match the
parameter type used for the template object under test. Also, provide
UInt32 equivalent delegate methods for some callers (with
int-equivalents for backwards compatibility).

This closes #2146.

Signed-off-by: Enji Cooper <yaneurabeya@gmail.com>

13 files changed, 89 insertions, 69 deletions

diff --git a/googlemock/test/gmock-matchers_test.cc b/googlemock/test/gmock-matchers_test.cc
index 8bdad637..5a5a7863 100644
--- a/googlemock/test/gmock-matchers_test.cc
+++ b/googlemock/test/gmock-matchers_test.cc
@@ -4311,7 +4311,8 @@ TEST(ResultOfTest, WorksForPolymorphicFunctorsIgnoringResultType) {
 
 TEST(ResultOfTest, WorksForLambdas) {
   Matcher<int> matcher =
-      ResultOf([](int str_len) { return std::string(str_len, 'x'); }, "xxx");
+      ResultOf([](int str_len) {
+          return std::string(static_cast<size_t>(str_len), 'x'); }, "xxx");
   EXPECT_TRUE(matcher.Matches(3));
   EXPECT_FALSE(matcher.Matches(1));
 }
@@ -5812,11 +5813,11 @@ class BacktrackingBPMTest : public ::testing::Test { };
 
 // Tests the MaxBipartiteMatching algorithm with square matrices.
 // The single int param is the # of nodes on each of the left and right sides.
-class BipartiteTest : public ::testing::TestWithParam<int> { };
+class BipartiteTest : public ::testing::TestWithParam<size_t> { };
 
 // Verify all match graphs up to some moderate number of edges.
 TEST_P(BipartiteTest, Exhaustive) {
-  int nodes = GetParam();
+  size_t nodes = GetParam();
   MatchMatrix graph(nodes, nodes);
   do {
     ElementMatcherPairs matches =
@@ -5841,7 +5842,8 @@ TEST_P(BipartiteTest, Exhaustive) {
 }
 
 INSTANTIATE_TEST_SUITE_P(AllGraphs, BipartiteTest,
-                        ::testing::Range(0, 5));
+                        ::testing::Range(static_cast<size_t>(0),
+                                         static_cast<size_t>(5)));
 
 // Parameterized by a pair interpreted as (LhsSize, RhsSize).
 class BipartiteNonSquareTest
@@ -5857,7 +5859,7 @@ TEST_F(BipartiteNonSquareTest, SimpleBacktracking) {
   //  :.......:
   //    0 1 2
   MatchMatrix g(4, 3);
-  static const int kEdges[][2] = {{0, 2}, {1, 1}, {2, 1}, {3, 0}};
+  static const size_t kEdges[][2] = {{0, 2}, {1, 1}, {2, 1}, {3, 0}};
   for (size_t i = 0; i < GTEST_ARRAY_SIZE_(kEdges); ++i) {
     g.SetEdge(kEdges[i][0], kEdges[i][1], true);
   }
@@ -5902,15 +5904,15 @@ class BipartiteRandomTest
 TEST_P(BipartiteRandomTest, LargerNets) {
   int nodes = GetParam().first;
   int iters = GetParam().second;
-  MatchMatrix graph(nodes, nodes);
+  MatchMatrix graph(static_cast<size_t>(nodes), static_cast<size_t>(nodes));
 
-  testing::internal::Int32 seed = GTEST_FLAG(random_seed);
+  auto seed = static_cast<testing::internal::UInt32>(GTEST_FLAG(random_seed));
   if (seed == 0) {
-    seed = static_cast<testing::internal::Int32>(time(nullptr));
+    seed = static_cast<testing::internal::UInt32>(time(nullptr));
   }
 
   for (; iters > 0; --iters, ++seed) {
-    srand(static_cast<int>(seed));
+    srand(static_cast<unsigned int>(seed));
     graph.Randomize();
     EXPECT_EQ(FindBacktrackingMaxBPM(graph).size(),
               internal::FindMaxBipartiteMatching(graph).size())
diff --git a/googletest/cmake/internal_utils.cmake b/googletest/cmake/internal_utils.cmake
index dfa72fa4..04def60f 100644
--- a/googletest/cmake/internal_utils.cmake
+++ b/googletest/cmake/internal_utils.cmake
@@ -78,7 +78,7 @@ macro(config_compiler_and_linker)
     # http://stackoverflow.com/questions/3232669 explains the issue.
     set(cxx_base_flags "${cxx_base_flags} -wd4702")
   elseif (CMAKE_CXX_COMPILER_ID STREQUAL "Clang")
-    set(cxx_base_flags "-Wall -Wshadow -Werror -Wno-error=sign-conversion")
+    set(cxx_base_flags "-Wall -Wshadow -Werror -Wconversion")
     set(cxx_exception_flags "-fexceptions")
     set(cxx_no_exception_flags "-fno-exceptions")
     set(cxx_strict_flags "-W -Wpointer-arith -Wreturn-type -Wcast-qual -Wwrite-strings -Wswitch -Wunused-parameter -Wcast-align -Wchar-subscripts -Winline -Wredundant-decls")
diff --git a/googletest/include/gtest/internal/gtest-internal.h b/googletest/include/gtest/internal/gtest-internal.h
index d16586c3..49887170 100644
--- a/googletest/include/gtest/internal/gtest-internal.h
+++ b/googletest/include/gtest/internal/gtest-internal.h
@@ -700,7 +700,7 @@ class TypeParameterizedTest {
     // list.
     MakeAndRegisterTestInfo(
         (std::string(prefix) + (prefix[0] == '\0' ? "" : "/") + case_name +
-         "/" + type_names[index])
+         "/" + type_names[static_cast<size_t>(index)])
             .c_str(),
         StripTrailingSpaces(GetPrefixUntilComma(test_names)).c_str(),
         GetTypeName<Type>().c_str(),
diff --git a/googletest/include/gtest/internal/gtest-string.h b/googletest/include/gtest/internal/gtest-string.h
index 4c9b6262..884b1e16 100644
--- a/googletest/include/gtest/internal/gtest-string.h
+++ b/googletest/include/gtest/internal/gtest-string.h
@@ -150,6 +150,9 @@ class GTEST_API_ String {
   // Formats an int value as "%X".
   static std::string FormatHexInt(int value);
 
+  // Formats an int value as "%X".
+  static std::string FormatHexUInt32(UInt32 value);
+
   // Formats a byte as "%02X".
   static std::string FormatByte(unsigned char value);
 
diff --git a/googletest/src/gtest-death-test.cc b/googletest/src/gtest-death-test.cc
index a78ab21a..52031f39 100644
--- a/googletest/src/gtest-death-test.cc
+++ b/googletest/src/gtest-death-test.cc
@@ -1350,7 +1350,7 @@ static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
 
   if (!use_fork) {
     static const bool stack_grows_down = StackGrowsDown();
-    const size_t stack_size = getpagesize();
+    const size_t stack_size = static_cast<size_t>(getpagesize());
     // MMAP_ANONYMOUS is not defined on Mac, so we use MAP_ANON instead.
     void* const stack = mmap(nullptr, stack_size, PROT_READ | PROT_WRITE,
                              MAP_ANON | MAP_PRIVATE, -1, 0);
@@ -1366,8 +1366,9 @@ static pid_t ExecDeathTestSpawnChild(char* const* argv, int close_fd) {
     void* const stack_top =
         static_cast<char*>(stack) +
             (stack_grows_down ? stack_size - kMaxStackAlignment : 0);
-    GTEST_DEATH_TEST_CHECK_(stack_size > kMaxStackAlignment &&
-        reinterpret_cast<intptr_t>(stack_top) % kMaxStackAlignment == 0);
+    GTEST_DEATH_TEST_CHECK_(
+        static_cast<size_t>(stack_size) > kMaxStackAlignment &&
+        reinterpret_cast<uintptr_t>(stack_top) % kMaxStackAlignment == 0);
 
     child_pid = clone(&ExecDeathTestChildMain, stack_top, SIGCHLD, &args);
 
diff --git a/googletest/src/gtest-filepath.cc b/googletest/src/gtest-filepath.cc
index 499ec587..322fbb1b 100644
--- a/googletest/src/gtest-filepath.cc
+++ b/googletest/src/gtest-filepath.cc
@@ -163,7 +163,7 @@ FilePath FilePath::RemoveFileName() const {
   const char* const last_sep = FindLastPathSeparator();
   std::string dir;
   if (last_sep) {
-    dir = std::string(c_str(), last_sep + 1 - c_str());
+    dir = std::string(c_str(), static_cast<size_t>(last_sep + 1 - c_str()));
   } else {
     dir = kCurrentDirectoryString;
   }
diff --git a/googletest/src/gtest-internal-inl.h b/googletest/src/gtest-internal-inl.h
index 29dc6820..b3e2724b 100644
--- a/googletest/src/gtest-internal-inl.h
+++ b/googletest/src/gtest-internal-inl.h
@@ -298,7 +298,8 @@ void ForEach(const Container& c, Functor functor) {
 // 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];
+  return (i < 0 || i >= static_cast<int>(v.size())) ? default_value :
+	  v[static_cast<size_t>(i)];
 }
 
 // Performs an in-place shuffle of a range of the vector's elements.
@@ -320,8 +321,10 @@ void ShuffleRange(internal::Random* random, int begin, int end,
   // 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]);
+    const int selected = begin +
+      static_cast<int>(random->Generate(static_cast<UInt32>(range_width)));
+    std::swap((*v)[static_cast<size_t>(selected)],
+              (*v)[static_cast<size_t>(last_in_range)]);
   }
 }
 
@@ -586,7 +589,7 @@ class GTEST_API_ UnitTestImpl {
   // total_test_suite_count() - 1. If i is not in that range, returns NULL.
   const TestSuite* GetTestSuite(int i) const {
     const int index = GetElementOr(test_suite_indices_, i, -1);
-    return index < 0 ? nullptr : test_suites_[i];
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(i)];
   }
 
   //  Legacy API is deprecated but still available
@@ -598,7 +601,7 @@ class GTEST_API_ UnitTestImpl {
   // total_test_suite_count() - 1. If i is not in that range, returns NULL.
   TestSuite* GetMutableSuiteCase(int i) {
     const int index = GetElementOr(test_suite_indices_, i, -1);
-    return index < 0 ? nullptr : test_suites_[index];
+    return index < 0 ? nullptr : test_suites_[static_cast<size_t>(index)];
   }
 
   // Provides access to the event listener list.
@@ -1083,8 +1086,8 @@ class StreamingListener : public EmptyTestEventListener {
       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) {
+      const size_t len = static_cast<size_t>(message.length());
+      if (write(sockfd_, message.c_str(), len) != static_cast<ssize_t>(len)) {
         GTEST_LOG_(WARNING)
             << "stream_result_to: failed to stream to "
             << host_name_ << ":" << port_num_;
diff --git a/googletest/src/gtest-port.cc b/googletest/src/gtest-port.cc
index 8f7cd1c0..e5b91fd0 100644
--- a/googletest/src/gtest-port.cc
+++ b/googletest/src/gtest-port.cc
@@ -117,7 +117,7 @@ T ReadProcFileField(const std::string& filename, int field) {
 size_t GetThreadCount() {
   const std::string filename =
       (Message() << "/proc/" << getpid() << "/stat").GetString();
-  return ReadProcFileField<int>(filename, 19);
+  return ReadProcFileField<size_t>(filename, 19);
 }
 
 #elif GTEST_OS_MAC
@@ -175,7 +175,7 @@ size_t GetThreadCount() {
   if (sysctl(mib, miblen, &info, &size, NULL, 0)) {
     return 0;
   }
-  return KP_NLWP(info);
+  return static_cast<size_t>(KP_NLWP(info));
 }
 #elif GTEST_OS_OPENBSD
 
diff --git a/googletest/src/gtest-test-part.cc b/googletest/src/gtest-test-part.cc
index 515b3084..178317a6 100644
--- a/googletest/src/gtest-test-part.cc
+++ b/googletest/src/gtest-test-part.cc
@@ -70,7 +70,7 @@ const TestPartResult& TestPartResultArray::GetTestPartResult(int index) const {
     internal::posix::Abort();
   }
 
-  return array_[index];
+  return array_[static_cast<size_t>(index)];
 }
 
 // Returns the number of TestPartResult objects in the array.
diff --git a/googletest/src/gtest.cc b/googletest/src/gtest.cc
index d4d3d035..320f7cf6 100644
--- a/googletest/src/gtest.cc
+++ b/googletest/src/gtest.cc
@@ -446,7 +446,8 @@ std::string UnitTestOptions::GetOutputFormat() {
   const char* const colon = strchr(gtest_output_flag, ':');
   return (colon == nullptr)
              ? std::string(gtest_output_flag)
-             : std::string(gtest_output_flag, colon - 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
@@ -1240,9 +1241,11 @@ std::string CreateUnifiedDiff(const std::vector<std::string>& left,
     for (; edit_i < edits.size(); ++edit_i) {
       if (n_suffix >= context) {
         // Continue only if the next hunk is very close.
-        std::vector<EditType>::const_iterator it = edits.begin() + edit_i;
+        std::vector<EditType>::const_iterator it = edits.begin() +
+                                                   static_cast<int>(edit_i);
         while (it != edits.end() && *it == kMatch) ++it;
-        if (it == edits.end() || (it - edits.begin()) - edit_i >= context) {
+        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;
         }
@@ -1767,7 +1770,7 @@ inline UInt32 ChopLowBits(UInt32* bits, int n) {
 // to "(Invalid Unicode 0xXXXXXXXX)".
 std::string CodePointToUtf8(UInt32 code_point) {
   if (code_point > kMaxCodePoint4) {
-    return "(Invalid Unicode 0x" + String::FormatHexInt(code_point) + ")";
+    return "(Invalid Unicode 0x" + String::FormatHexUInt32(code_point) + ")";
   }
 
   char str[5];  // Big enough for the largest valid code point.
@@ -1808,12 +1811,14 @@ inline bool IsUtf16SurrogatePair(wchar_t first, wchar_t second) {
 // Creates a Unicode code point from UTF16 surrogate pair.
 inline UInt32 CreateCodePointFromUtf16SurrogatePair(wchar_t first,
                                                     wchar_t second) {
+  const UInt32 first_u = static_cast<UInt32>(first);
+  const UInt32 second_u = static_cast<UInt32>(second);
   const UInt32 mask = (1 << 10) - 1;
   return (sizeof(wchar_t) == 2) ?
-      (((first & mask) << 10) | (second & mask)) + 0x10000 :
+      (((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.
-      static_cast<UInt32>(first);
+      first_u;
 }
 
 // Converts a wide string to a narrow string in UTF-8 encoding.
@@ -1970,12 +1975,17 @@ std::string String::FormatIntWidth2(int value) {
 }
 
 // Formats an int value as "%X".
-std::string String::FormatHexInt(int value) {
+std::string String::FormatHexUInt32(UInt32 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>(value));
+}
+
 // Formats a byte as "%02X".
 std::string String::FormatByte(unsigned char value) {
   std::stringstream ss;
@@ -1992,7 +2002,7 @@ std::string StringStreamToString(::std::stringstream* ss) {
   const char* const end = start + str.length();
 
   std::string result;
-  result.reserve(2 * (end - start));
+  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";
@@ -2036,7 +2046,7 @@ TestResult::~TestResult() {
 const TestPartResult& TestResult::GetTestPartResult(int i) const {
   if (i < 0 || i >= total_part_count())
     internal::posix::Abort();
-  return test_part_results_.at(i);
+  return test_part_results_.at(static_cast<size_t>(i));
 }
 
 // Returns the i-th test property. i can range from 0 to
@@ -2045,7 +2055,7 @@ const TestPartResult& TestResult::GetTestPartResult(int i) const {
 const TestProperty& TestResult::GetTestProperty(int i) const {
   if (i < 0 || i >= test_property_count())
     internal::posix::Abort();
-  return test_properties_.at(i);
+  return test_properties_.at(static_cast<size_t>(i));
 }
 
 // Clears the test part results.
@@ -2776,14 +2786,14 @@ TestSuite::~TestSuite() {
 // 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_[index];
+  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_[index];
+  return index < 0 ? nullptr : test_info_list_[static_cast<size_t>(index)];
 }
 
 // Adds a test to this test suite.  Will delete the test upon
@@ -3401,7 +3411,7 @@ void TestEventRepeater::Append(TestEventListener *listener) {
 TestEventListener* TestEventRepeater::Release(TestEventListener *listener) {
   for (size_t i = 0; i < listeners_.size(); ++i) {
     if (listeners_[i] == listener) {
-      listeners_.erase(listeners_.begin() + i);
+      listeners_.erase(listeners_.begin() + static_cast<int>(i));
       return listener;
     }
   }
@@ -3424,8 +3434,8 @@ void TestEventRepeater::Name(const Type& parameter) { \
 #define GTEST_REVERSE_REPEATER_METHOD_(Name, Type) \
 void TestEventRepeater::Name(const Type& parameter) { \
   if (forwarding_enabled_) { \
-    for (int i = static_cast<int>(listeners_.size()) - 1; i >= 0; i--) { \
-      listeners_[i]->Name(parameter); \
+    for (size_t i = listeners_.size(); i != 0; i--) { \
+      listeners_[i-1]->Name(parameter); \
     } \
   } \
 }
@@ -3465,8 +3475,8 @@ void TestEventRepeater::OnTestIterationStart(const UnitTest& unit_test,
 void TestEventRepeater::OnTestIterationEnd(const UnitTest& unit_test,
                                            int iteration) {
   if (forwarding_enabled_) {
-    for (int i = static_cast<int>(listeners_.size()) - 1; i >= 0; i--) {
-      listeners_[i]->OnTestIterationEnd(unit_test, iteration);
+    for (size_t i = listeners_.size(); i > 0; i--) {
+      listeners_[i-1]->OnTestIterationEnd(unit_test, iteration);
     }
   }
 }
@@ -4069,8 +4079,8 @@ static std::string FormatEpochTimeInMillisAsRFC3339(TimeInMillis ms) {
       String::FormatIntWidth2(time_struct.tm_sec) + "Z";
 }
 
-static inline std::string Indent(int width) {
-  return std::string(width, ' ');
+static inline std::string Indent(size_t width) {
+  return std::string(static_cast<size_t>(width), ' ');
 }
 
 void JsonUnitTestResultPrinter::OutputJsonKey(
@@ -4726,8 +4736,7 @@ void UnitTest::AddTestPartResult(
   if (impl_->gtest_trace_stack().size() > 0) {
     msg << "\n" << GTEST_NAME_ << " trace:";
 
-    for (int i = static_cast<int>(impl_->gtest_trace_stack().size());
-         i > 0; --i) {
+    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;
@@ -5237,7 +5246,7 @@ bool UnitTestImpl::RunAllTests() {
 
     // Shuffles test suites and tests if requested.
     if (has_tests_to_run && GTEST_FLAG(shuffle)) {
-      random()->Reseed(random_seed_);
+      random()->Reseed(static_cast<UInt32>(random_seed_));
       // This should be done before calling OnTestIterationStart(),
       // such that a test event listener can see the actual test order
       // in the event.
diff --git a/googletest/test/googletest-death-test-test.cc b/googletest/test/googletest-death-test-test.cc
index b8645414..272b9c36 100644
--- a/googletest/test/googletest-death-test-test.cc
+++ b/googletest/test/googletest-death-test-test.cc
@@ -884,10 +884,12 @@ class MockDeathTestFactory : public DeathTestFactory {
   int AssumeRoleCalls() const { return assume_role_calls_; }
   int WaitCalls() const { return wait_calls_; }
   size_t PassedCalls() const { return passed_args_.size(); }
-  bool PassedArgument(int n) const { return passed_args_[n]; }
+  bool PassedArgument(int n) const {
+    return passed_args_[static_cast<size_t>(n)];
+  }
   size_t AbortCalls() const { return abort_args_.size(); }
   DeathTest::AbortReason AbortArgument(int n) const {
-    return abort_args_[n];
+    return abort_args_[static_cast<size_t>(n)];
   }
   bool TestDeleted() const { return test_deleted_; }
 
diff --git a/googletest/test/googletest-port-test.cc b/googletest/test/googletest-port-test.cc
index 6cb791e5..42035cc9 100644
--- a/googletest/test/googletest-port-test.cc
+++ b/googletest/test/googletest-port-test.cc
@@ -1048,7 +1048,7 @@ class AtomicCounterWithMutex {
           pthread_mutex_init(&memory_barrier_mutex, nullptr));
       GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_lock(&memory_barrier_mutex));
 
-      SleepMilliseconds(random_.Generate(30));
+      SleepMilliseconds(static_cast<int>(random_.Generate(30)));
 
       GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_unlock(&memory_barrier_mutex));
       GTEST_CHECK_POSIX_SUCCESS_(pthread_mutex_destroy(&memory_barrier_mutex));
@@ -1056,7 +1056,7 @@ class AtomicCounterWithMutex {
       // On Windows, performing an interlocked access puts up a memory barrier.
       volatile LONG dummy = 0;
       ::InterlockedIncrement(&dummy);
-      SleepMilliseconds(random_.Generate(30));
+      SleepMilliseconds(static_cast<int>(random_.Generate(30)));
       ::InterlockedIncrement(&dummy);
 #else
 # error "Memory barrier not implemented on this platform."
diff --git a/googletest/test/gtest_unittest.cc b/googletest/test/gtest_unittest.cc
index 9c1827d4..0c8bf99c 100644
--- a/googletest/test/gtest_unittest.cc
+++ b/googletest/test/gtest_unittest.cc
@@ -899,23 +899,23 @@ TEST(ContainerUtilityDeathTest, ShuffleRange) {
 
 class VectorShuffleTest : public Test {
  protected:
-  static const int kVectorSize = 20;
+  static const size_t kVectorSize = 20;
 
   VectorShuffleTest() : random_(1) {
-    for (int i = 0; i < kVectorSize; i++) {
+    for (int i = 0; i < static_cast<int>(kVectorSize); i++) {
       vector_.push_back(i);
     }
   }
 
   static bool VectorIsCorrupt(const TestingVector& vector) {
-    if (kVectorSize != static_cast<int>(vector.size())) {
+    if (kVectorSize != vector.size()) {
       return true;
     }
 
     bool found_in_vector[kVectorSize] = { false };
     for (size_t i = 0; i < vector.size(); i++) {
       const int e = vector[i];
-      if (e < 0 || e >= kVectorSize || found_in_vector[e]) {
+      if (e < 0 || e >= static_cast<int>(kVectorSize) || found_in_vector[e]) {
         return true;
       }
       found_in_vector[e] = true;
@@ -932,7 +932,7 @@ class VectorShuffleTest : public Test {
 
   static bool RangeIsShuffled(const TestingVector& vector, int begin, int end) {
     for (int i = begin; i < end; i++) {
-      if (i != vector[i]) {
+      if (i != vector[static_cast<size_t>(i)]) {
         return true;
       }
     }
@@ -956,7 +956,7 @@ class VectorShuffleTest : public Test {
   TestingVector vector_;
 };  // class VectorShuffleTest
 
-const int VectorShuffleTest::kVectorSize;
+const size_t VectorShuffleTest::kVectorSize;
 
 TEST_F(VectorShuffleTest, HandlesEmptyRange) {
   // Tests an empty range at the beginning...
@@ -1008,7 +1008,7 @@ TEST_F(VectorShuffleTest, ShufflesEntireVector) {
   // Tests the first and last elements in particular to ensure that
   // there are no off-by-one problems in our shuffle algorithm.
   EXPECT_NE(0, vector_[0]);
-  EXPECT_NE(kVectorSize - 1, vector_[kVectorSize - 1]);
+  EXPECT_NE(static_cast<int>(kVectorSize - 1), vector_[kVectorSize - 1]);
 }
 
 TEST_F(VectorShuffleTest, ShufflesStartOfVector) {
@@ -1018,7 +1018,7 @@ TEST_F(VectorShuffleTest, ShufflesStartOfVector) {
 
   ASSERT_PRED1(VectorIsNotCorrupt, vector_);
   EXPECT_PRED3(RangeIsShuffled, vector_, 0, kRangeSize);
-  EXPECT_PRED3(RangeIsUnshuffled, vector_, kRangeSize, kVectorSize);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, kRangeSize, static_cast<int>(kVectorSize));
 }
 
 TEST_F(VectorShuffleTest, ShufflesEndOfVector) {
@@ -1027,23 +1027,23 @@ TEST_F(VectorShuffleTest, ShufflesEndOfVector) {
 
   ASSERT_PRED1(VectorIsNotCorrupt, vector_);
   EXPECT_PRED3(RangeIsUnshuffled, vector_, 0, kRangeSize);
-  EXPECT_PRED3(RangeIsShuffled, vector_, kRangeSize, kVectorSize);
+  EXPECT_PRED3(RangeIsShuffled, vector_, kRangeSize, static_cast<int>(kVectorSize));
 }
 
 TEST_F(VectorShuffleTest, ShufflesMiddleOfVector) {
-  int kRangeSize = kVectorSize/3;
+  int kRangeSize = static_cast<int>(kVectorSize)/3;
   ShuffleRange(&random_, kRangeSize, 2*kRangeSize, &vector_);
 
   ASSERT_PRED1(VectorIsNotCorrupt, vector_);
   EXPECT_PRED3(RangeIsUnshuffled, vector_, 0, kRangeSize);
   EXPECT_PRED3(RangeIsShuffled, vector_, kRangeSize, 2*kRangeSize);
-  EXPECT_PRED3(RangeIsUnshuffled, vector_, 2*kRangeSize, kVectorSize);
+  EXPECT_PRED3(RangeIsUnshuffled, vector_, 2*kRangeSize, static_cast<int>(kVectorSize));
 }
 
 TEST_F(VectorShuffleTest, ShufflesRepeatably) {
   TestingVector vector2;
-  for (int i = 0; i < kVectorSize; i++) {
-    vector2.push_back(i);
+  for (size_t i = 0; i < kVectorSize; i++) {
+    vector2.push_back(static_cast<int>(i));
   }
 
   random_.Reseed(1234);
@@ -1054,7 +1054,7 @@ TEST_F(VectorShuffleTest, ShufflesRepeatably) {
   ASSERT_PRED1(VectorIsNotCorrupt, vector_);
   ASSERT_PRED1(VectorIsNotCorrupt, vector2);
 
-  for (int i = 0; i < kVectorSize; i++) {
+  for (size_t i = 0; i < kVectorSize; i++) {
     EXPECT_EQ(vector_[i], vector2[i]) << " where i is " << i;
   }
 }
@@ -3496,7 +3496,7 @@ std::string EditsToString(const std::vector<EditType>& edits) {
 std::vector<size_t> CharsToIndices(const std::string& str) {
   std::vector<size_t> out;
   for (size_t i = 0; i < str.size(); ++i) {
-    out.push_back(str[i]);
+    out.push_back(static_cast<size_t>(str[i]));
   }
   return out;
 }
@@ -5654,11 +5654,11 @@ class ParseFlagsTest : public Test {
 
   // Asserts that two narrow or wide string arrays are equal.
   template <typename CharType>
-  static void AssertStringArrayEq(size_t size1, CharType** array1,
-                                  size_t size2, CharType** array2) {
+  static void AssertStringArrayEq(int size1, CharType** array1,
+                                  int size2, CharType** array2) {
     ASSERT_EQ(size1, size2) << " Array sizes different.";
 
-    for (size_t i = 0; i != size1; i++) {
+    for (int i = 0; i != size1; i++) {
       ASSERT_STREQ(array1[i], array2[i]) << " where i == " << i;
     }
   }