PR #1706: Require CMake version 3.16

Imported from GitHub PR #1706

Follow Google OSS policy.
Merge 2ba42b9 into af4c589

Merging this change closes #1706

COPYBARA_INTEGRATE_REVIEW=#1706 from gruenich:feature/cmake-3-16 2ba42b9
PiperOrigin-RevId: 650646746
Change-Id: Ib600608fbc727161c8b8e69cda9a09637188fef8

Author: gruenich

CMake/Googletest/CMakeLists.txt.in

@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.16)
 
 project(googletest-external NONE)
 

CMake/README.md

@@ -39,7 +39,7 @@ section of your executable or of your library.<br>
 Here is a short CMakeLists.txt example of an application project using Abseil.
 
 ```cmake
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.16)
 project(my_app_project)
 
 # Pick the C++ standard to compile with.
@@ -62,7 +62,7 @@ will control Abseil library targets) is set to at least that minimum. For
 example:
 
 ```cmake
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.16)
 project(my_lib_project)
 
 # Leave C++ standard up to the root application, so set it only if this is the

CMake/install_test_project/CMakeLists.txt

@@ -15,7 +15,7 @@
 
 # A simple CMakeLists.txt for testing cmake installation
 
-cmake_minimum_required(VERSION 3.10)
+cmake_minimum_required(VERSION 3.16)
 project(absl_cmake_testing CXX)
 
 add_executable(simple simple.cc)

CMakeLists.txt

@@ -15,43 +15,8 @@
 #
 
 # https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md
-# As of 2022-09-06, CMake 3.10 is the minimum supported version.
-cmake_minimum_required(VERSION 3.10)
-
-# Compiler id for Apple Clang is now AppleClang.
-if (POLICY CMP0025)
-  cmake_policy(SET CMP0025 NEW)
-endif (POLICY CMP0025)
-
-# if command can use IN_LIST
-if (POLICY CMP0057)
-  cmake_policy(SET CMP0057 NEW)
-endif (POLICY CMP0057)
-
-# Project version variables are the empty string if version is unspecified
-if (POLICY CMP0048)
-  cmake_policy(SET CMP0048 NEW)
-endif (POLICY CMP0048)
-
-# Honor the GTest_ROOT variable if specified
-if (POLICY CMP0074)
-  cmake_policy(SET CMP0074 NEW)
-endif (POLICY CMP0074)
-
-# option() honor variables
-if (POLICY CMP0077)
-  cmake_policy(SET CMP0077 NEW)
-endif (POLICY CMP0077)
-
-# Allow the user to specify the MSVC runtime
-if (POLICY CMP0091)
-  cmake_policy(SET CMP0091 NEW)
-endif (POLICY CMP0091)
-
-# try_compile() honors the CMAKE_CXX_STANDARD value
-if (POLICY CMP0067)
-  cmake_policy(SET CMP0067 NEW)
-endif (POLICY CMP0067)
+# As of 2024-07-01, CMake 3.16 is the minimum supported version.
+cmake_minimum_required(VERSION 3.16)
 
 # Allow the user to specify the CMAKE_MSVC_DEBUG_INFORMATION_FORMAT
 if (POLICY CMP0141)