From b111d01c1b4cc86da08672a68cddcbcc1cedd742 Mon Sep 17 00:00:00 2001
From: Carlos O'Ryan <coryan@google.com>
Date: Fri, 17 Feb 2023 08:38:53 -0500
Subject: [PATCH] cleanup: support CMake >= 3.10 (#1544)

* cleanup: support CMake >= 3.10

This aligns the project with the CMake support policies in:

https://opensource.google/documentation/policies/cplusplus-support

I also simplied the management of CMake policies. Most of the overriden
policies (anything <= CMP0067) are enabled by default when you require
CMake >= 3.10.  But it is easier to just declare that you will accept
newer policies when they are available using the `...3.22` notation.

* Address review comments

* inlined links

---------

Co-authored-by: dominic <510002+dmah42@users.noreply.github.com>
---
 CMakeLists.txt       | 17 ++---------------
 docs/dependencies.md | 21 ++++++++-------------
 2 files changed, 10 insertions(+), 28 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index 59e86b24..ccec880c 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -1,18 +1,5 @@
-cmake_minimum_required (VERSION 3.16.3)
-
-foreach(p
-    CMP0048 # OK to clear PROJECT_VERSION on project()
-    CMP0054 # CMake 3.1
-    CMP0056 # export EXE_LINKER_FLAGS to try_run
-    CMP0057 # Support no if() IN_LIST operator
-    CMP0063 # Honor visibility properties for all targets
-    CMP0067 # Honor language standard in try_compile() source file signature
-    CMP0077 # Allow option() overrides in importing projects
-    )
-  if(POLICY ${p})
-    cmake_policy(SET ${p} NEW)
-  endif()
-endforeach()
+# Require CMake 3.10. If available, use the policies up to CMake 3.22.
+cmake_minimum_required (VERSION 3.10...3.22)
 
 project (benchmark VERSION 1.7.1 LANGUAGES CXX)
 
diff --git a/docs/dependencies.md b/docs/dependencies.md
index 98aae42a..07760e10 100644
--- a/docs/dependencies.md
+++ b/docs/dependencies.md
@@ -1,18 +1,13 @@
 # Build tool dependency policy
 
-To ensure the broadest compatibility when building the benchmark library, but
-still allow forward progress, we require any build tooling to be available for:
+We follow the [Foundational C++ support policy](https://opensource.google/documentation/policies/cplusplus-support) for our build tools. In
+particular the ["Build Systems" section](https://opensource.google/documentation/policies/cplusplus-support#build-systems).
 
-* Debian stable _and_
-* The last two Ubuntu LTS releases
+## CMake
 
-Currently, this means using build tool versions that are available for Ubuntu
-Ubuntu 20.04 (Focal Fossa), Ubuntu 22.04 (Jammy Jellyfish) and Debian 11.4 (bullseye).
-
-## cmake
-The current supported version is cmake 3.16.3 as of 2022-08-10.
-
-* 3.16.3 (ubuntu 20.04)
-* 3.18.4 (debian 11.4)
-* 3.22.1 (ubuntu 22.04)
+The current supported version is CMake 3.10 as of 2023-08-10. Most modern
+distributions include newer versions, for example:
 
+* Ubuntu 20.04 provides CMake 3.16.3
+* Debian 11.4 provides CMake 3.18.4
+* Ubuntu 22.04 provides CMake 3.22.1