diff --git a/ci/linux-presubmit.sh b/ci/linux-presubmit.sh
index 003664e5..0818ef0b 100644
--- a/ci/linux-presubmit.sh
+++ b/ci/linux-presubmit.sh
@@ -31,7 +31,7 @@
 
 set -euox pipefail
 
-readonly LINUX_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20210617"
+readonly LINUX_LATEST_CONTAINER="gcr.io/google.com/absl-177019/linux_hybrid-latest:20220113"
 readonly LINUX_GCC_FLOOR_CONTAINER="gcr.io/google.com/absl-177019/linux_gcc-floor:20210617"
 
 if [[ -z ${GTEST_ROOT:-} ]]; then
diff --git a/docs/gmock_faq.md b/docs/gmock_faq.md
index 2cd9b3f3..8f220bf7 100644
--- a/docs/gmock_faq.md
+++ b/docs/gmock_faq.md
@@ -369,8 +369,8 @@ Usually, if your action is for a particular function type, defining it using
 different types (e.g. if you are defining `Return(*value*)`),
 `MakePolymorphicAction()` is easiest. Sometimes you want precise control on what
 types of functions the action can be used in, and implementing `ActionInterface`
-is the way to go here. See the implementation of `Return()` in
-`testing/base/public/gmock-actions.h` for an example.
+is the way to go here. See the implementation of `Return()` in `gmock-actions.h`
+for an example.
 
 ### I use SetArgPointee() in WillOnce(), but gcc complains about "conflicting return type specified". What does it mean?
 
diff --git a/googlemock/include/gmock/gmock-actions.h b/googlemock/include/gmock/gmock-actions.h
index 0046aaf6..72663c85 100644
--- a/googlemock/include/gmock/gmock-actions.h
+++ b/googlemock/include/gmock/gmock-actions.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // The ACTION* family of macros can be used in a namespace scope to
@@ -125,6 +124,9 @@
 // To learn more about using these macros, please search for 'ACTION' on
 // https://github.com/google/googletest/blob/master/docs/gmock_cook_book.md
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_ACTIONS_H_
 
diff --git a/googlemock/include/gmock/gmock-cardinalities.h b/googlemock/include/gmock/gmock-cardinalities.h
index c45fd641..48196dd2 100644
--- a/googlemock/include/gmock/gmock-cardinalities.h
+++ b/googlemock/include/gmock/gmock-cardinalities.h
@@ -27,13 +27,15 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file implements some commonly used cardinalities.  More
 // cardinalities can be defined by the user implementing the
 // CardinalityInterface interface if necessary.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_CARDINALITIES_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_CARDINALITIES_H_
 
diff --git a/googlemock/include/gmock/gmock-function-mocker.h b/googlemock/include/gmock/gmock-function-mocker.h
index e6913e58..2de1d41b 100644
--- a/googlemock/include/gmock/gmock-function-mocker.h
+++ b/googlemock/include/gmock/gmock-function-mocker.h
@@ -31,6 +31,9 @@
 //
 // This file implements MOCK_METHOD.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_FUNCTION_MOCKER_H_  // NOLINT
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_FUNCTION_MOCKER_H_  // NOLINT
 
diff --git a/googlemock/include/gmock/gmock-matchers.h b/googlemock/include/gmock/gmock-matchers.h
index cb91fcb0..5cf5019d 100644
--- a/googlemock/include/gmock/gmock-matchers.h
+++ b/googlemock/include/gmock/gmock-matchers.h
@@ -249,6 +249,9 @@
 // See googletest/include/gtest/gtest-matchers.h for the definition of class
 // Matcher, class MatcherInterface, and others.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MATCHERS_H_
 
diff --git a/googlemock/include/gmock/gmock-more-actions.h b/googlemock/include/gmock/gmock-more-actions.h
index ffbe43c1..bf85ff51 100644
--- a/googlemock/include/gmock/gmock-more-actions.h
+++ b/googlemock/include/gmock/gmock-more-actions.h
@@ -27,11 +27,13 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file implements some commonly used variadic actions.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_ACTIONS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_ACTIONS_H_
 
diff --git a/googlemock/include/gmock/gmock-more-matchers.h b/googlemock/include/gmock/gmock-more-matchers.h
index 5affa4f8..6442d2fa 100644
--- a/googlemock/include/gmock/gmock-more-matchers.h
+++ b/googlemock/include/gmock/gmock-more-matchers.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file implements some matchers that depend on gmock-matchers.h.
@@ -35,6 +34,9 @@
 // Note that tests are implemented in gmock-matchers_test.cc rather than
 // gmock-more-matchers-test.cc.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_MATCHERS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_MORE_MATCHERS_H_
 
diff --git a/googlemock/include/gmock/gmock-nice-strict.h b/googlemock/include/gmock/gmock-nice-strict.h
index 101e0d75..f421deaf 100644
--- a/googlemock/include/gmock/gmock-nice-strict.h
+++ b/googlemock/include/gmock/gmock-nice-strict.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Implements class templates NiceMock, NaggyMock, and StrictMock.
 //
 // Given a mock class MockFoo that is created using Google Mock,
@@ -58,6 +57,9 @@
 // In particular, nesting NiceMock, NaggyMock, and StrictMock is NOT
 // supported.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_NICE_STRICT_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_NICE_STRICT_H_
 
diff --git a/googlemock/include/gmock/gmock-spec-builders.h b/googlemock/include/gmock/gmock-spec-builders.h
index 8e9f2f1f..dfe642dc 100644
--- a/googlemock/include/gmock/gmock-spec-builders.h
+++ b/googlemock/include/gmock/gmock-spec-builders.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file implements the ON_CALL() and EXPECT_CALL() macros.
@@ -56,6 +55,9 @@
 // where all clauses are optional, and .InSequence()/.After()/
 // .WillOnce() can appear any number of times.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_GMOCK_SPEC_BUILDERS_H_
 
diff --git a/googlemock/include/gmock/gmock.h b/googlemock/include/gmock/gmock.h
index 3a728db6..568c8c71 100644
--- a/googlemock/include/gmock/gmock.h
+++ b/googlemock/include/gmock/gmock.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This is the main header file a user should include.
@@ -62,6 +61,7 @@
 #include "gmock/gmock-more-matchers.h"
 #include "gmock/gmock-nice-strict.h"
 #include "gmock/internal/gmock-internal-utils.h"
+#include "gmock/internal/gmock-port.h"
 
 // Declares Google Mock flags that we want a user to use programmatically.
 GMOCK_DECLARE_bool_(catch_leaked_mocks);
diff --git a/googlemock/include/gmock/internal/custom/gmock-generated-actions.h b/googlemock/include/gmock/internal/custom/gmock-generated-actions.h
index 39ddeacb..bbcad31c 100644
--- a/googlemock/include/gmock/internal/custom/gmock-generated-actions.h
+++ b/googlemock/include/gmock/internal/custom/gmock-generated-actions.h
@@ -1,3 +1,6 @@
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_GENERATED_ACTIONS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_GENERATED_ACTIONS_H_
 
diff --git a/googlemock/include/gmock/internal/custom/gmock-matchers.h b/googlemock/include/gmock/internal/custom/gmock-matchers.h
index f8261171..bb7dcbaa 100644
--- a/googlemock/include/gmock/internal/custom/gmock-matchers.h
+++ b/googlemock/include/gmock/internal/custom/gmock-matchers.h
@@ -26,9 +26,12 @@
 // 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.
-//
+
 // Injection point for custom user configurations. See README for details
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_
 #endif  // GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_MATCHERS_H_
diff --git a/googlemock/include/gmock/internal/custom/gmock-port.h b/googlemock/include/gmock/internal/custom/gmock-port.h
index db03ed23..f055f750 100644
--- a/googlemock/include/gmock/internal/custom/gmock-port.h
+++ b/googlemock/include/gmock/internal/custom/gmock-port.h
@@ -26,11 +26,14 @@
 // 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.
-//
+
 // Injection point for custom user configurations. See README for details
 //
 // ** Custom implementation starts here **
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_PORT_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_CUSTOM_GMOCK_PORT_H_
 
diff --git a/googlemock/include/gmock/internal/gmock-internal-utils.h b/googlemock/include/gmock/internal/gmock-internal-utils.h
index 577f52fd..d9d812a3 100644
--- a/googlemock/include/gmock/internal/gmock-internal-utils.h
+++ b/googlemock/include/gmock/internal/gmock-internal-utils.h
@@ -27,13 +27,15 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Mock - a framework for writing C++ mock classes.
 //
 // This file defines some utilities useful for implementing Google
 // Mock.  They are subject to change without notice, so please DO NOT
 // USE THEM IN USER CODE.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_INTERNAL_UTILS_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_INTERNAL_UTILS_H_
 
diff --git a/googlemock/include/gmock/internal/gmock-port.h b/googlemock/include/gmock/internal/gmock-port.h
index 5d3e0e59..998f6c79 100644
--- a/googlemock/include/gmock/internal/gmock-port.h
+++ b/googlemock/include/gmock/internal/gmock-port.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-//
 // Low-level types and utilities for porting Google Mock to various
 // platforms.  All macros ending with _ and symbols defined in an
 // internal namespace are subject to change without notice.  Code
@@ -35,6 +34,9 @@
 // end with _ are part of Google Mock's public API and can be used by
 // code outside Google Mock.
 
+// IWYU pragma: private, include "gmock/gmock.h"
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PORT_H_
 #define GOOGLEMOCK_INCLUDE_GMOCK_INTERNAL_GMOCK_PORT_H_
 
diff --git a/googletest/include/gtest/gtest-assertion-result.h b/googletest/include/gtest/gtest-assertion-result.h
new file mode 100644
index 00000000..e020c489
--- /dev/null
+++ b/googletest/include/gtest/gtest-assertion-result.h
@@ -0,0 +1,232 @@
+// 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)
+//
+// This file implements the AssertionResult type.
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
+#ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
+#define GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
+
+#include <memory>
+#include <ostream>
+#include <string>
+#include <type_traits>
+
+#include "gtest/gtest-message.h"
+#include "gtest/internal/gtest-port.h"
+
+namespace testing {
+
+// A class for indicating whether an assertion was successful.  When
+// the assertion wasn't successful, the AssertionResult object
+// remembers a non-empty message that describes how it failed.
+//
+// To create an instance of this class, use one of the factory functions
+// (AssertionSuccess() and AssertionFailure()).
+//
+// This class is useful for two purposes:
+//   1. Defining predicate functions to be used with Boolean test assertions
+//      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
+//   2. Defining predicate-format functions to be
+//      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
+//
+// For example, if you define IsEven predicate:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
+// will print the message
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false (5 is odd)
+//   Expected: true
+//
+// instead of a more opaque
+//
+//   Value of: IsEven(Fib(5))
+//     Actual: false
+//   Expected: true
+//
+// in case IsEven is a simple Boolean predicate.
+//
+// If you expect your predicate to be reused and want to support informative
+// messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
+// about half as often as positive ones in our tests), supply messages for
+// both success and failure cases:
+//
+//   testing::AssertionResult IsEven(int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess() << n << " is even";
+//     else
+//       return testing::AssertionFailure() << n << " is odd";
+//   }
+//
+// Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
+//
+//   Value of: IsEven(Fib(6))
+//     Actual: true (8 is even)
+//   Expected: false
+//
+// NB: Predicates that support negative Boolean assertions have reduced
+// performance in positive ones so be careful not to use them in tests
+// that have lots (tens of thousands) of positive Boolean assertions.
+//
+// To use this class with EXPECT_PRED_FORMAT assertions such as:
+//
+//   // Verifies that Foo() returns an even number.
+//   EXPECT_PRED_FORMAT1(IsEven, Foo());
+//
+// you need to define:
+//
+//   testing::AssertionResult IsEven(const char* expr, int n) {
+//     if ((n % 2) == 0)
+//       return testing::AssertionSuccess();
+//     else
+//       return testing::AssertionFailure()
+//         << "Expected: " << expr << " is even\n  Actual: it's " << n;
+//   }
+//
+// If Foo() returns 5, you will see the following message:
+//
+//   Expected: Foo() is even
+//     Actual: it's 5
+//
+class GTEST_API_ AssertionResult {
+ public:
+  // Copy constructor.
+  // Used in EXPECT_TRUE/FALSE(assertion_result).
+  AssertionResult(const AssertionResult& other);
+
+// C4800 is a level 3 warning in Visual Studio 2015 and earlier.
+// This warning is not emitted in Visual Studio 2017.
+// This warning is off by default starting in Visual Studio 2019 but can be
+// enabled with command-line options.
+#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
+  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
+#endif
+
+  // Used in the EXPECT_TRUE/FALSE(bool_expression).
+  //
+  // T must be contextually convertible to bool.
+  //
+  // The second parameter prevents this overload from being considered if
+  // the argument is implicitly convertible to AssertionResult. In that case
+  // we want AssertionResult's copy constructor to be used.
+  template <typename T>
+  explicit AssertionResult(
+      const T& success,
+      typename std::enable_if<
+          !std::is_convertible<T, AssertionResult>::value>::type*
+      /*enabler*/
+      = nullptr)
+      : success_(success) {}
+
+#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
+  GTEST_DISABLE_MSC_WARNINGS_POP_()
+#endif
+
+  // Assignment operator.
+  AssertionResult& operator=(AssertionResult other) {
+    swap(other);
+    return *this;
+  }
+
+  // Returns true if and only if the assertion succeeded.
+  operator bool() const { return success_; }  // NOLINT
+
+  // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
+  AssertionResult operator!() const;
+
+  // Returns the text streamed into this AssertionResult. Test assertions
+  // use it when they fail (i.e., the predicate's outcome doesn't match the
+  // assertion's expectation). When nothing has been streamed into the
+  // object, returns an empty string.
+  const char* message() const {
+    return message_.get() != nullptr ? message_->c_str() : "";
+  }
+  // Deprecated; please use message() instead.
+  const char* failure_message() const { return message(); }
+
+  // Streams a custom failure message into this object.
+  template <typename T>
+  AssertionResult& operator<<(const T& value) {
+    AppendMessage(Message() << value);
+    return *this;
+  }
+
+  // Allows streaming basic output manipulators such as endl or flush into
+  // this object.
+  AssertionResult& operator<<(
+      ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
+    AppendMessage(Message() << basic_manipulator);
+    return *this;
+  }
+
+ private:
+  // Appends the contents of message to message_.
+  void AppendMessage(const Message& a_message) {
+    if (message_.get() == nullptr) message_.reset(new ::std::string);
+    message_->append(a_message.GetString().c_str());
+  }
+
+  // Swap the contents of this AssertionResult with other.
+  void swap(AssertionResult& other);
+
+  // Stores result of the assertion predicate.
+  bool success_;
+  // Stores the message describing the condition in case the expectation
+  // construct is not satisfied with the predicate's outcome.
+  // Referenced via a pointer to avoid taking too much stack frame space
+  // with test assertions.
+  std::unique_ptr< ::std::string> message_;
+};
+
+// Makes a successful assertion result.
+GTEST_API_ AssertionResult AssertionSuccess();
+
+// Makes a failed assertion result.
+GTEST_API_ AssertionResult AssertionFailure();
+
+// Makes a failed assertion result with the given failure message.
+// Deprecated; use AssertionFailure() << msg.
+GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
+
+}  // namespace testing
+
+#endif  // GOOGLETEST_INCLUDE_GTEST_GTEST_ASSERTION_RESULT_H_
diff --git a/googletest/include/gtest/gtest-death-test.h b/googletest/include/gtest/gtest-death-test.h
index 33effe18..cd34e1f2 100644
--- a/googletest/include/gtest/gtest-death-test.h
+++ b/googletest/include/gtest/gtest-death-test.h
@@ -27,13 +27,16 @@
 // (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)
 //
 // This header file defines the public API for death tests.  It is
 // #included by gtest.h so a user doesn't need to include this
 // directly.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_DEATH_TEST_H_
 
diff --git a/googletest/include/gtest/gtest-matchers.h b/googletest/include/gtest/gtest-matchers.h
index 9fa34a05..3472db7e 100644
--- a/googletest/include/gtest/gtest-matchers.h
+++ b/googletest/include/gtest/gtest-matchers.h
@@ -32,6 +32,10 @@
 // This file implements just enough of the matcher interface to allow
 // EXPECT_DEATH and friends to accept a matcher argument.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_MATCHERS_H_
 
diff --git a/googletest/include/gtest/gtest-message.h b/googletest/include/gtest/gtest-message.h
index bad51611..9419229f 100644
--- a/googletest/include/gtest/gtest-message.h
+++ b/googletest/include/gtest/gtest-message.h
@@ -27,7 +27,6 @@
 // (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)
 //
 // This header file defines the Message class.
@@ -42,6 +41,10 @@
 // to CHANGE WITHOUT NOTICE.  Therefore DO NOT DEPEND ON IT in a user
 // program!
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_MESSAGE_H_
 
diff --git a/googletest/include/gtest/gtest-param-test.h b/googletest/include/gtest/gtest-param-test.h
index 5558117f..96c1c722 100644
--- a/googletest/include/gtest/gtest-param-test.h
+++ b/googletest/include/gtest/gtest-param-test.h
@@ -26,9 +26,14 @@
 // 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.
-//
+
 // Macros and functions for implementing parameterized tests
 // in Google C++ Testing and Mocking Framework (Google Test)
+
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_PARAM_TEST_H_
 
diff --git a/googletest/include/gtest/gtest-printers.h b/googletest/include/gtest/gtest-printers.h
index e07b537d..b097e988 100644
--- a/googletest/include/gtest/gtest-printers.h
+++ b/googletest/include/gtest/gtest-printers.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Google Test - The Google C++ Testing and Mocking Framework
 //
 // This file implements a universal value printer that can print a
@@ -95,6 +94,10 @@
 // being defined as many user-defined container types don't have
 // value_type.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_PRINTERS_H_
 
diff --git a/googletest/include/gtest/gtest-spi.h b/googletest/include/gtest/gtest-spi.h
index bce8b22d..12c94e4a 100644
--- a/googletest/include/gtest/gtest-spi.h
+++ b/googletest/include/gtest/gtest-spi.h
@@ -27,7 +27,6 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-//
 // Utilities for testing Google Test itself and code that uses Google Test
 // (e.g. frameworks built on top of Google Test).
 
diff --git a/googletest/include/gtest/gtest-test-part.h b/googletest/include/gtest/gtest-test-part.h
index db9f4b93..39393b21 100644
--- a/googletest/include/gtest/gtest-test-part.h
+++ b/googletest/include/gtest/gtest-test-part.h
@@ -27,6 +27,10 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_TEST_PART_H_
 
diff --git a/googletest/include/gtest/gtest-typed-test.h b/googletest/include/gtest/gtest-typed-test.h
index 8e078b39..343bf6fe 100644
--- a/googletest/include/gtest/gtest-typed-test.h
+++ b/googletest/include/gtest/gtest-typed-test.h
@@ -27,6 +27,10 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_TYPED_TEST_H_
 
diff --git a/googletest/include/gtest/gtest.h b/googletest/include/gtest/gtest.h
index 1bb9decc..a4174cd4 100644
--- a/googletest/include/gtest/gtest.h
+++ b/googletest/include/gtest/gtest.h
@@ -27,7 +27,6 @@
 // (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)
 //
 // This header file defines the public API for Google Test.  It should be
@@ -57,16 +56,18 @@
 #include <type_traits>
 #include <vector>
 
-#include "gtest/internal/gtest-internal.h"
-#include "gtest/internal/gtest-string.h"
+#include "gtest/gtest-assertion-result.h"
 #include "gtest/gtest-death-test.h"
 #include "gtest/gtest-matchers.h"
 #include "gtest/gtest-message.h"
 #include "gtest/gtest-param-test.h"
 #include "gtest/gtest-printers.h"
-#include "gtest/gtest_prod.h"
 #include "gtest/gtest-test-part.h"
 #include "gtest/gtest-typed-test.h"
+#include "gtest/gtest_pred_impl.h"
+#include "gtest/gtest_prod.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-string.h"
 
 GTEST_DISABLE_MSC_WARNINGS_PUSH_(4251 \
 /* class A needs to have dll-interface to be used by clients of class B */)
@@ -204,193 +205,6 @@ using TestCase = TestSuite;
 class TestInfo;
 class UnitTest;
 
-// A class for indicating whether an assertion was successful.  When
-// the assertion wasn't successful, the AssertionResult object
-// remembers a non-empty message that describes how it failed.
-//
-// To create an instance of this class, use one of the factory functions
-// (AssertionSuccess() and AssertionFailure()).
-//
-// This class is useful for two purposes:
-//   1. Defining predicate functions to be used with Boolean test assertions
-//      EXPECT_TRUE/EXPECT_FALSE and their ASSERT_ counterparts
-//   2. Defining predicate-format functions to be
-//      used with predicate assertions (ASSERT_PRED_FORMAT*, etc).
-//
-// For example, if you define IsEven predicate:
-//
-//   testing::AssertionResult IsEven(int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess();
-//     else
-//       return testing::AssertionFailure() << n << " is odd";
-//   }
-//
-// Then the failed expectation EXPECT_TRUE(IsEven(Fib(5)))
-// will print the message
-//
-//   Value of: IsEven(Fib(5))
-//     Actual: false (5 is odd)
-//   Expected: true
-//
-// instead of a more opaque
-//
-//   Value of: IsEven(Fib(5))
-//     Actual: false
-//   Expected: true
-//
-// in case IsEven is a simple Boolean predicate.
-//
-// If you expect your predicate to be reused and want to support informative
-// messages in EXPECT_FALSE and ASSERT_FALSE (negative assertions show up
-// about half as often as positive ones in our tests), supply messages for
-// both success and failure cases:
-//
-//   testing::AssertionResult IsEven(int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess() << n << " is even";
-//     else
-//       return testing::AssertionFailure() << n << " is odd";
-//   }
-//
-// Then a statement EXPECT_FALSE(IsEven(Fib(6))) will print
-//
-//   Value of: IsEven(Fib(6))
-//     Actual: true (8 is even)
-//   Expected: false
-//
-// NB: Predicates that support negative Boolean assertions have reduced
-// performance in positive ones so be careful not to use them in tests
-// that have lots (tens of thousands) of positive Boolean assertions.
-//
-// To use this class with EXPECT_PRED_FORMAT assertions such as:
-//
-//   // Verifies that Foo() returns an even number.
-//   EXPECT_PRED_FORMAT1(IsEven, Foo());
-//
-// you need to define:
-//
-//   testing::AssertionResult IsEven(const char* expr, int n) {
-//     if ((n % 2) == 0)
-//       return testing::AssertionSuccess();
-//     else
-//       return testing::AssertionFailure()
-//         << "Expected: " << expr << " is even\n  Actual: it's " << n;
-//   }
-//
-// If Foo() returns 5, you will see the following message:
-//
-//   Expected: Foo() is even
-//     Actual: it's 5
-//
-class GTEST_API_ AssertionResult {
- public:
-  // Copy constructor.
-  // Used in EXPECT_TRUE/FALSE(assertion_result).
-  AssertionResult(const AssertionResult& other);
-
-// C4800 is a level 3 warning in Visual Studio 2015 and earlier.
-// This warning is not emitted in Visual Studio 2017.
-// This warning is off by default starting in Visual Studio 2019 but can be
-// enabled with command-line options.
-#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
-  GTEST_DISABLE_MSC_WARNINGS_PUSH_(4800 /* forcing value to bool */)
-#endif
-
-  // Used in the EXPECT_TRUE/FALSE(bool_expression).
-  //
-  // T must be contextually convertible to bool.
-  //
-  // The second parameter prevents this overload from being considered if
-  // the argument is implicitly convertible to AssertionResult. In that case
-  // we want AssertionResult's copy constructor to be used.
-  template <typename T>
-  explicit AssertionResult(
-      const T& success,
-      typename std::enable_if<
-          !std::is_convertible<T, AssertionResult>::value>::type*
-      /*enabler*/
-      = nullptr)
-      : success_(success) {}
-
-#if defined(_MSC_VER) && (_MSC_VER < 1910 || _MSC_VER >= 1920)
-  GTEST_DISABLE_MSC_WARNINGS_POP_()
-#endif
-
-  // Assignment operator.
-  AssertionResult& operator=(AssertionResult other) {
-    swap(other);
-    return *this;
-  }
-
-  // Returns true if and only if the assertion succeeded.
-  operator bool() const { return success_; }  // NOLINT
-
-  // Returns the assertion's negation. Used with EXPECT/ASSERT_FALSE.
-  AssertionResult operator!() const;
-
-  // Returns the text streamed into this AssertionResult. Test assertions
-  // use it when they fail (i.e., the predicate's outcome doesn't match the
-  // assertion's expectation). When nothing has been streamed into the
-  // object, returns an empty string.
-  const char* message() const {
-    return message_.get() != nullptr ? message_->c_str() : "";
-  }
-  // Deprecated; please use message() instead.
-  const char* failure_message() const { return message(); }
-
-  // Streams a custom failure message into this object.
-  template <typename T> AssertionResult& operator<<(const T& value) {
-    AppendMessage(Message() << value);
-    return *this;
-  }
-
-  // Allows streaming basic output manipulators such as endl or flush into
-  // this object.
-  AssertionResult& operator<<(
-      ::std::ostream& (*basic_manipulator)(::std::ostream& stream)) {
-    AppendMessage(Message() << basic_manipulator);
-    return *this;
-  }
-
- private:
-  // Appends the contents of message to message_.
-  void AppendMessage(const Message& a_message) {
-    if (message_.get() == nullptr) message_.reset(new ::std::string);
-    message_->append(a_message.GetString().c_str());
-  }
-
-  // Swap the contents of this AssertionResult with other.
-  void swap(AssertionResult& other);
-
-  // Stores result of the assertion predicate.
-  bool success_;
-  // Stores the message describing the condition in case the expectation
-  // construct is not satisfied with the predicate's outcome.
-  // Referenced via a pointer to avoid taking too much stack frame space
-  // with test assertions.
-  std::unique_ptr< ::std::string> message_;
-};
-
-// Makes a successful assertion result.
-GTEST_API_ AssertionResult AssertionSuccess();
-
-// Makes a failed assertion result.
-GTEST_API_ AssertionResult AssertionFailure();
-
-// Makes a failed assertion result with the given failure message.
-// Deprecated; use AssertionFailure() << msg.
-GTEST_API_ AssertionResult AssertionFailure(const Message& msg);
-
-}  // namespace testing
-
-// Includes the auto-generated header that implements a family of generic
-// predicate assertion macros. This include comes late because it relies on
-// APIs declared above.
-#include "gtest/gtest_pred_impl.h"
-
-namespace testing {
-
 // The abstract class that all tests inherit from.
 //
 // In Google Test, a unit test program contains one or many TestSuites, and
diff --git a/googletest/include/gtest/gtest_pred_impl.h b/googletest/include/gtest/gtest_pred_impl.h
index 67a96c9f..96b36fab 100644
--- a/googletest/include/gtest/gtest_pred_impl.h
+++ b/googletest/include/gtest/gtest_pred_impl.h
@@ -32,10 +32,16 @@
 //
 // Implements a family of generic predicate assertion macros.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_PRED_IMPL_H_
 
-#include "gtest/gtest.h"
+#include "gtest/gtest-assertion-result.h"
+#include "gtest/internal/gtest-internal.h"
+#include "gtest/internal/gtest-port.h"
 
 namespace testing {
 
diff --git a/googletest/include/gtest/gtest_prod.h b/googletest/include/gtest/gtest_prod.h
index 25766ee7..b22030a8 100644
--- a/googletest/include/gtest/gtest_prod.h
+++ b/googletest/include/gtest/gtest_prod.h
@@ -27,8 +27,8 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-//
-// Google C++ Testing and Mocking Framework definitions useful in production code.
+// Google C++ Testing and Mocking Framework definitions useful in production
+// code.
 
 #ifndef GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
 #define GOOGLETEST_INCLUDE_GTEST_GTEST_PROD_H_
diff --git a/googletest/include/gtest/internal/gtest-death-test-internal.h b/googletest/include/gtest/internal/gtest-death-test-internal.h
index 8e0023a9..128e0f4c 100644
--- a/googletest/include/gtest/internal/gtest-death-test-internal.h
+++ b/googletest/include/gtest/internal/gtest-death-test-internal.h
@@ -26,12 +26,16 @@
 // 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)
 //
 // This header file defines internal utilities needed for implementing
 // death tests.  They are subject to change without notice.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_DEATH_TEST_INTERNAL_H_
 
diff --git a/googletest/include/gtest/internal/gtest-filepath.h b/googletest/include/gtest/internal/gtest-filepath.h
index 43f47dcc..4dfe2e22 100644
--- a/googletest/include/gtest/internal/gtest-filepath.h
+++ b/googletest/include/gtest/internal/gtest-filepath.h
@@ -26,7 +26,7 @@
 // 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.
-//
+
 // Google Test filepath utilities
 //
 // This header file declares classes and functions used internally by
@@ -35,6 +35,10 @@
 // This file is #included in gtest/internal/gtest-internal.h.
 // Do not include this header file separately!
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_FILEPATH_H_
 
diff --git a/googletest/include/gtest/internal/gtest-internal.h b/googletest/include/gtest/internal/gtest-internal.h
index 4e66667d..fc15e947 100644
--- a/googletest/include/gtest/internal/gtest-internal.h
+++ b/googletest/include/gtest/internal/gtest-internal.h
@@ -26,12 +26,16 @@
 // 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)
 //
 // This header file declares functions and macros used internally by
 // Google Test.  They are subject to change without notice.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_INTERNAL_H_
 
diff --git a/googletest/include/gtest/internal/gtest-param-util.h b/googletest/include/gtest/internal/gtest-param-util.h
index d2312c00..ff25d995 100644
--- a/googletest/include/gtest/internal/gtest-param-util.h
+++ b/googletest/include/gtest/internal/gtest-param-util.h
@@ -27,9 +27,12 @@
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
-
 // Type and function utilities for implementing parameterized tests.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PARAM_UTIL_H_
 
diff --git a/googletest/include/gtest/internal/gtest-port-arch.h b/googletest/include/gtest/internal/gtest-port-arch.h
index 4dcdc89c..22bbad97 100644
--- a/googletest/include/gtest/internal/gtest-port-arch.h
+++ b/googletest/include/gtest/internal/gtest-port-arch.h
@@ -26,7 +26,7 @@
 // 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)
 //
 // This header file defines the GTEST_OS_* macro.
diff --git a/googletest/include/gtest/internal/gtest-port.h b/googletest/include/gtest/internal/gtest-port.h
index e6ae256f..945b6ec0 100644
--- a/googletest/include/gtest/internal/gtest-port.h
+++ b/googletest/include/gtest/internal/gtest-port.h
@@ -26,7 +26,7 @@
 // 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.
-//
+
 // Low-level types and utilities for porting Google Test to various
 // platforms.  All macros ending with _ and symbols defined in an
 // internal namespace are subject to change without notice.  Code
@@ -38,6 +38,10 @@
 // files are expected to #include this.  Therefore, it cannot #include
 // any other Google Test header.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_PORT_H_
 
diff --git a/googletest/include/gtest/internal/gtest-string.h b/googletest/include/gtest/internal/gtest-string.h
index 0f2bcbec..4cb8e07c 100644
--- a/googletest/include/gtest/internal/gtest-string.h
+++ b/googletest/include/gtest/internal/gtest-string.h
@@ -26,7 +26,7 @@
 // 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)
 //
 // This header file declares the String class and functions used internally by
@@ -36,6 +36,10 @@
 // This header file is #included by gtest-internal.h.
 // It should not be #included by other files.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_STRING_H_
 
diff --git a/googletest/include/gtest/internal/gtest-type-util.h b/googletest/include/gtest/internal/gtest-type-util.h
index 90910e99..665564a9 100644
--- a/googletest/include/gtest/internal/gtest-type-util.h
+++ b/googletest/include/gtest/internal/gtest-type-util.h
@@ -30,6 +30,10 @@
 // Type utilities needed for implementing typed and type-parameterized
 // tests.
 
+// IWYU pragma: private, include "gtest/gtest.h"
+// IWYU pragma: friend gtest/.*
+// IWYU pragma: friend gmock/.*
+
 #ifndef GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
 #define GOOGLETEST_INCLUDE_GTEST_INTERNAL_GTEST_TYPE_UTIL_H_
 
diff --git a/googletest/src/gtest-all.cc b/googletest/src/gtest-all.cc
index ad292905..29eba165 100644
--- a/googletest/src/gtest-all.cc
+++ b/googletest/src/gtest-all.cc
@@ -39,6 +39,7 @@
 
 // The following lines pull in the real gtest *.cc files.
 #include "src/gtest.cc"
+#include "src/gtest-assertion-result.cc"
 #include "src/gtest-death-test.cc"
 #include "src/gtest-filepath.cc"
 #include "src/gtest-matchers.cc"
diff --git a/googletest/src/gtest-assertion-result.cc b/googletest/src/gtest-assertion-result.cc
new file mode 100644
index 00000000..9f90e872
--- /dev/null
+++ b/googletest/src/gtest-assertion-result.cc
@@ -0,0 +1,81 @@
+// 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)
+//
+// This file defines the AssertionResult type.
+
+#include "gtest/gtest-assertion-result.h"
+
+#include <utility>
+#include <string>
+
+#include "gtest/gtest-message.h"
+
+namespace testing {
+
+// 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 testing
diff --git a/googletest/src/gtest.cc b/googletest/src/gtest.cc
index fb5ed181..af79075a 100644
--- a/googletest/src/gtest.cc
+++ b/googletest/src/gtest.cc
@@ -31,8 +31,6 @@
 // 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 <stdarg.h>
@@ -54,6 +52,10 @@
 #include <sstream>
 #include <vector>
 
+#include "gtest/gtest-assertion-result.h"
+#include "gtest/gtest-spi.h"
+#include "gtest/internal/custom/gtest.h"
+
 #if GTEST_OS_LINUX
 
 # include <fcntl.h>  // NOLINT
@@ -1207,44 +1209,6 @@ 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 {
@@ -4093,8 +4057,9 @@ std::string XmlUnitTestResultPrinter::EscapeXml(
           m << '"';
         break;
       default:
-        if (IsValidXmlCharacter(ch)) {
-          if (is_attribute && IsNormalizableWhitespace(ch))
+        if (IsValidXmlCharacter(static_cast<unsigned char>(ch))) {
+          if (is_attribute &&
+              IsNormalizableWhitespace(static_cast<unsigned char>(ch)))
             m << "&#x" << String::FormatByte(static_cast<unsigned char>(ch))
               << ";";
           else
@@ -4115,7 +4080,7 @@ std::string XmlUnitTestResultPrinter::RemoveInvalidXmlCharacters(
   std::string output;
   output.reserve(str.size());
   for (std::string::const_iterator it = str.begin(); it != str.end(); ++it)
-    if (IsValidXmlCharacter(*it))
+    if (IsValidXmlCharacter(static_cast<unsigned char>(*it)))
       output.push_back(*it);
 
   return output;