From a49d450a54c9116d107e921505f1d22efdaa6365 Mon Sep 17 00:00:00 2001
From: Esun Kim <veblush@google.com>
Date: Mon, 30 Sep 2024 10:52:26 -0700
Subject: [PATCH] [Build] Bumped the minimum version of cmake (#37702)

Per https://github.com/google/oss-policies-info/blob/main/foundational-cxx-support-matrix.md, the minimum version of cmake to support is 3.16 so let's change our cmake builds' requirements accordingly.

Closes #37702

COPYBARA_INTEGRATE_REVIEW=https://github.com/grpc/grpc/pull/37702 from veblush:cmake316 bb4ed1a1be5e9374980c922aac3dc1ccd27d1266
PiperOrigin-RevId: 680639191
---
 CMakeLists.txt                                               | 2 +-
 examples/android/helloworld/app/CMakeLists.txt               | 2 +-
 examples/cpp/auth/CMakeLists.txt                             | 2 +-
 examples/cpp/cancellation/CMakeLists.txt                     | 2 +-
 examples/cpp/cmake/common.cmake                              | 2 +-
 examples/cpp/compression/CMakeLists.txt                      | 2 +-
 examples/cpp/deadline/CMakeLists.txt                         | 2 +-
 examples/cpp/error_details/CMakeLists.txt                    | 2 +-
 examples/cpp/error_handling/CMakeLists.txt                   | 2 +-
 examples/cpp/flow_control/CMakeLists.txt                     | 2 +-
 examples/cpp/generic_api/CMakeLists.txt                      | 2 +-
 examples/cpp/health/CMakeLists.txt                           | 2 +-
 examples/cpp/helloworld/CMakeLists.txt                       | 2 +-
 examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt | 2 +-
 examples/cpp/interceptors/CMakeLists.txt                     | 2 +-
 examples/cpp/keepalive/CMakeLists.txt                        | 2 +-
 examples/cpp/load_balancing/CMakeLists.txt                   | 2 +-
 examples/cpp/metadata/CMakeLists.txt                         | 2 +-
 examples/cpp/multiplex/CMakeLists.txt                        | 2 +-
 examples/cpp/otel/CMakeLists.txt                             | 2 +-
 examples/cpp/otel/codelab/CMakeLists.txt                     | 2 +-
 examples/cpp/otel/ostream/CMakeLists.txt                     | 2 +-
 examples/cpp/retry/CMakeLists.txt                            | 2 +-
 examples/cpp/route_guide/CMakeLists.txt                      | 2 +-
 examples/cpp/wait_for_ready/CMakeLists.txt                   | 2 +-
 src/android/test/interop/app/CMakeLists.txt                  | 2 +-
 src/cpp/README.md                                            | 2 +-
 templates/CMakeLists.txt.template                            | 2 +-
 28 files changed, 28 insertions(+), 28 deletions(-)

diff --git a/CMakeLists.txt b/CMakeLists.txt
index da1e9c4ae87..85b51d334d2 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -22,7 +22,7 @@
 
 
 
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.16)
 
 set(PACKAGE_NAME          "grpc")
 set(PACKAGE_VERSION       "1.68.0-dev")
diff --git a/examples/android/helloworld/app/CMakeLists.txt b/examples/android/helloworld/app/CMakeLists.txt
index 4524d3e0250..70c2d65668c 100644
--- a/examples/android/helloworld/app/CMakeLists.txt
+++ b/examples/android/helloworld/app/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 set(helloworld_PROTOBUF_PROTOC_EXECUTABLE "/usr/local/bin/protoc" CACHE STRING "Protoc binary on host")
 set(helloworld_GRPC_CPP_PLUGIN_EXECUTABLE "/usr/local/bin/grpc_cpp_plugin" CACHE STRING "gRPC CPP plugin binary on host")
diff --git a/examples/cpp/auth/CMakeLists.txt b/examples/cpp/auth/CMakeLists.txt
index 1f28ba6bcc8..c1a97cd9f65 100644
--- a/examples/cpp/auth/CMakeLists.txt
+++ b/examples/cpp/auth/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building keyvaluestore.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Cancellation C CXX)
 
diff --git a/examples/cpp/cancellation/CMakeLists.txt b/examples/cpp/cancellation/CMakeLists.txt
index c82111b5239..e98472bba65 100644
--- a/examples/cpp/cancellation/CMakeLists.txt
+++ b/examples/cpp/cancellation/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building keyvaluestore.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Cancellation C CXX)
 
diff --git a/examples/cpp/cmake/common.cmake b/examples/cpp/cmake/common.cmake
index df9bc4db0f8..9637a2ad26c 100644
--- a/examples/cpp/cmake/common.cmake
+++ b/examples/cpp/cmake/common.cmake
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building route_guide.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 if(MSVC)
   add_definitions(-D_WIN32_WINNT=0x600)
diff --git a/examples/cpp/compression/CMakeLists.txt b/examples/cpp/compression/CMakeLists.txt
index ca89acff47a..63cc4400ec4 100644
--- a/examples/cpp/compression/CMakeLists.txt
+++ b/examples/cpp/compression/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Compression C CXX)
 
diff --git a/examples/cpp/deadline/CMakeLists.txt b/examples/cpp/deadline/CMakeLists.txt
index 1cf3462e31c..e0353f26df6 100644
--- a/examples/cpp/deadline/CMakeLists.txt
+++ b/examples/cpp/deadline/CMakeLists.txt
@@ -16,7 +16,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building this example.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Deadline C CXX)
 
diff --git a/examples/cpp/error_details/CMakeLists.txt b/examples/cpp/error_details/CMakeLists.txt
index 3b32bc74900..36582ce67b8 100644
--- a/examples/cpp/error_details/CMakeLists.txt
+++ b/examples/cpp/error_details/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(ErrorDetails C CXX)
 
diff --git a/examples/cpp/error_handling/CMakeLists.txt b/examples/cpp/error_handling/CMakeLists.txt
index 1ae09cc8c5f..14b6414c502 100644
--- a/examples/cpp/error_handling/CMakeLists.txt
+++ b/examples/cpp/error_handling/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(ErrorHandling C CXX)
 
diff --git a/examples/cpp/flow_control/CMakeLists.txt b/examples/cpp/flow_control/CMakeLists.txt
index 0d6d4353177..48c7576220d 100644
--- a/examples/cpp/flow_control/CMakeLists.txt
+++ b/examples/cpp/flow_control/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building example.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(HelloWorld C CXX)
 
diff --git a/examples/cpp/generic_api/CMakeLists.txt b/examples/cpp/generic_api/CMakeLists.txt
index 44e3820f0ab..988e44ca4f3 100644
--- a/examples/cpp/generic_api/CMakeLists.txt
+++ b/examples/cpp/generic_api/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(GenericAPI C CXX)
 
diff --git a/examples/cpp/health/CMakeLists.txt b/examples/cpp/health/CMakeLists.txt
index 963e82f0a3e..fc19ddb9785 100644
--- a/examples/cpp/health/CMakeLists.txt
+++ b/examples/cpp/health/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(HelloWorld C CXX)
 
diff --git a/examples/cpp/helloworld/CMakeLists.txt b/examples/cpp/helloworld/CMakeLists.txt
index defe3064b14..23c7ccd9211 100644
--- a/examples/cpp/helloworld/CMakeLists.txt
+++ b/examples/cpp/helloworld/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(HelloWorld C CXX)
 
diff --git a/examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt b/examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt
index 8c1218a053d..e370cc48084 100644
--- a/examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt
+++ b/examples/cpp/helloworld/cmake_externalproject/CMakeLists.txt
@@ -20,7 +20,7 @@
 # including the "helloworld" project itself.
 # See https://blog.kitware.com/cmake-superbuilds-git-submodules/
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 # Project
 project(HelloWorld-SuperBuild C CXX)
diff --git a/examples/cpp/interceptors/CMakeLists.txt b/examples/cpp/interceptors/CMakeLists.txt
index 38b7c83c570..69c64fbe2cf 100644
--- a/examples/cpp/interceptors/CMakeLists.txt
+++ b/examples/cpp/interceptors/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building keyvaluestore.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(KeyValueStore C CXX)
 
diff --git a/examples/cpp/keepalive/CMakeLists.txt b/examples/cpp/keepalive/CMakeLists.txt
index 8053fba1df6..95bbaed5e6b 100644
--- a/examples/cpp/keepalive/CMakeLists.txt
+++ b/examples/cpp/keepalive/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(HelloWorld C CXX)
 
diff --git a/examples/cpp/load_balancing/CMakeLists.txt b/examples/cpp/load_balancing/CMakeLists.txt
index 786a508b272..73ea0c33968 100644
--- a/examples/cpp/load_balancing/CMakeLists.txt
+++ b/examples/cpp/load_balancing/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(LoadBalancing C CXX)
 
diff --git a/examples/cpp/metadata/CMakeLists.txt b/examples/cpp/metadata/CMakeLists.txt
index 7a95323b16a..36cacacd4f2 100644
--- a/examples/cpp/metadata/CMakeLists.txt
+++ b/examples/cpp/metadata/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Metadata C CXX)
 
diff --git a/examples/cpp/multiplex/CMakeLists.txt b/examples/cpp/multiplex/CMakeLists.txt
index d0b97a37f26..185e79a3965 100644
--- a/examples/cpp/multiplex/CMakeLists.txt
+++ b/examples/cpp/multiplex/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Multiplex C CXX)
 
diff --git a/examples/cpp/otel/CMakeLists.txt b/examples/cpp/otel/CMakeLists.txt
index b81a2538a89..3718b5c8ae3 100644
--- a/examples/cpp/otel/CMakeLists.txt
+++ b/examples/cpp/otel/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.16)
 
 project(grpc_opentelemetry_example C CXX)
 
diff --git a/examples/cpp/otel/codelab/CMakeLists.txt b/examples/cpp/otel/codelab/CMakeLists.txt
index 6ce38d77a2f..9403822c2b7 100644
--- a/examples/cpp/otel/codelab/CMakeLists.txt
+++ b/examples/cpp/otel/codelab/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.16)
 
 project(grpc_opentelemetry_example C CXX)
 
diff --git a/examples/cpp/otel/ostream/CMakeLists.txt b/examples/cpp/otel/ostream/CMakeLists.txt
index c0d9a58a988..9b37a5d19f8 100644
--- a/examples/cpp/otel/ostream/CMakeLists.txt
+++ b/examples/cpp/otel/ostream/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.13)
+cmake_minimum_required(VERSION 3.16)
 
 project(grpc_opentelemetry_example C CXX)
 
diff --git a/examples/cpp/retry/CMakeLists.txt b/examples/cpp/retry/CMakeLists.txt
index f01e360bb7a..b07149a2cf6 100644
--- a/examples/cpp/retry/CMakeLists.txt
+++ b/examples/cpp/retry/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building retry.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(Retry C CXX)
 
diff --git a/examples/cpp/route_guide/CMakeLists.txt b/examples/cpp/route_guide/CMakeLists.txt
index 90cebda39b1..bc321a00d57 100644
--- a/examples/cpp/route_guide/CMakeLists.txt
+++ b/examples/cpp/route_guide/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building route_guide.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(RouteGuide C CXX)
 
diff --git a/examples/cpp/wait_for_ready/CMakeLists.txt b/examples/cpp/wait_for_ready/CMakeLists.txt
index 06024dfbc9b..472ece2d651 100644
--- a/examples/cpp/wait_for_ready/CMakeLists.txt
+++ b/examples/cpp/wait_for_ready/CMakeLists.txt
@@ -17,7 +17,7 @@
 # See cmake_externalproject/CMakeLists.txt for all-in-one cmake build
 # that automatically builds all the dependencies before building helloworld.
 
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 project(HelloWorld C CXX)
 
diff --git a/src/android/test/interop/app/CMakeLists.txt b/src/android/test/interop/app/CMakeLists.txt
index 403f1e518d8..83444593191 100644
--- a/src/android/test/interop/app/CMakeLists.txt
+++ b/src/android/test/interop/app/CMakeLists.txt
@@ -1,4 +1,4 @@
-cmake_minimum_required(VERSION 3.8)
+cmake_minimum_required(VERSION 3.16)
 
 set(PROTOBUF_PROTOC_EXECUTABLE "/usr/local/bin/protoc" CACHE STRING "Protoc binary on host")
 set(gRPC_CPP_PLUGIN_EXECUTABLE "/usr/local/bin/grpc_cpp_plugin" CACHE STRING "gRPC CPP plugin binary on host")
diff --git a/src/cpp/README.md b/src/cpp/README.md
index 780528b9c5e..84c19b79187 100755
--- a/src/cpp/README.md
+++ b/src/cpp/README.md
@@ -107,7 +107,7 @@ also sets up an `add_subdirectory()` rule for you. This causes gRPC to be
 built as part of your project.
 
 ```cmake
-cmake_minimum_required(VERSION 3.15)
+cmake_minimum_required(VERSION 3.16)
 project(my_project)
 
 include(FetchContent)
diff --git a/templates/CMakeLists.txt.template b/templates/CMakeLists.txt.template
index a3e7503f373..f5b7480d639 100644
--- a/templates/CMakeLists.txt.template
+++ b/templates/CMakeLists.txt.template
@@ -275,7 +275,7 @@
         protobuf_gen_files.add(src)
   %>
 
-  cmake_minimum_required(VERSION 3.13)
+  cmake_minimum_required(VERSION 3.16)
 
   set(PACKAGE_NAME          "grpc")
   set(PACKAGE_VERSION       "${settings.cpp_version}")