CMake: project for HelloWorld cpp example

examples/cpp/helloworld/CMakeLists.txt

+# Minimum CMake required
+cmake_minimum_required(VERSION 2.8)
+
+# Project
+project(HelloWorld CXX)
+
+# Protobuf
+set(protobuf_MODULE_COMPATIBLE TRUE)
+find_package(protobuf CONFIG REQUIRED)
+message(STATUS "Using protobuf ${protobuf_VERSION}")
+
+# gRPC
+find_package(gRPC CONFIG REQUIRED)
+message(STATUS "Using gRPC ${gRPC_VERSION}")
+
+# gRPC C++ plugin
+get_target_property(gRPC_CPP_PLUGIN_EXECUTABLE gRPC::grpc_cpp_plugin
+    IMPORTED_LOCATION_RELEASE)
+
+# Proto file
+get_filename_component(hw_proto "../../protos/helloworld.proto" ABSOLUTE)
+get_filename_component(hw_proto_path "${hw_proto}" PATH)
+
+# Generated sources
+protobuf_generate_cpp(hw_proto_srcs hw_proto_hdrs "${hw_proto}")
+set(hw_grpc_srcs "${CMAKE_CURRENT_BINARY_DIR}/helloworld.grpc.pb.cc")
+set(hw_grpc_hdrs "${CMAKE_CURRENT_BINARY_DIR}/helloworld.grpc.pb.h")
+add_custom_command(
+      OUTPUT "${hw_grpc_srcs}" "${hw_grpc_hdrs}"
+      COMMAND protobuf::protoc
+      ARGS --grpc_out "${CMAKE_CURRENT_BINARY_DIR}" -I "${hw_proto_path}"
+        --plugin=protoc-gen-grpc="${gRPC_CPP_PLUGIN_EXECUTABLE}"
+        "${hw_proto}"
+      DEPENDS "${hw_proto}")
+
+# Generated include directory
+include_directories("${CMAKE_CURRENT_BINARY_DIR}")
+
+# Targets greeter_[async_](client|server)
+foreach(_target
+  greeter_client greeter_server
+  greeter_async_client greeter_async_server)
+  add_executable(${_target} "${_target}.cc"
+    ${hw_proto_srcs}
+    ${hw_grpc_srcs})
+  target_link_libraries(${_target}
+    protobuf::libprotobuf
+    gRPC::grpc++_unsecure)
+endforeach()