add distribtest for grpc being added with cmake add_subdirectory

1 files changed, 48 insertions, 15 deletions

diff --git a/examples/cpp/helloworld/CMakeLists.txt b/examples/cpp/helloworld/CMakeLists.txt
index 4f7d3fdddb..d0f705f6d9 100644
--- a/examples/cpp/helloworld/CMakeLists.txt
+++ b/examples/cpp/helloworld/CMakeLists.txt
@@ -27,22 +27,55 @@ else()
   add_definitions(-D_WIN32_WINNT=0x600)

 endif()

 

-# Find Protobuf installation

-# Looks for protobuf-config.cmake file installed by Protobuf's cmake installation.

-set(protobuf_MODULE_COMPATIBLE TRUE)

-find_package(Protobuf CONFIG REQUIRED)

-message(STATUS "Using protobuf ${protobuf_VERSION}")

+if(GRPC_AS_SUBMODULE)

+  # One way to build a projects that uses gRPC is to just include the

+  # entire gRPC project tree via "add_subdirectory".

+  # This approach is very simple to use, but the are some potential

+  # disadvantages:

+  # * it includes gRPC's CMakeLists.txt directly into your build script

+  #   without and that can make gRPC's internal setting interfere with your

+  #   own build.

+  # * depending on what's installed on your system, the contents of submodules

+  #   in gRPC's third_party/* might need to be available (and there might be

+  #   additional prerequisites required to build them). Consider using

+  #   the gRPC_*_PROVIDER options to fine-tune the expected behavior.

+  #

+  # A more robust approach to add dependency on gRPC is using

+  # cmake's ExternalProject_Add (see cmake_externalproject/CMakeLists.txt).

+  

+  # Include the gRPC's cmake build (normally grpc source code would live

+  # in a git submodule called "third_party/grpc", but this example lives in

+  # the same repository as gRPC sources, so we just look a few directories up)

+  add_subdirectory(../../.. ${CMAKE_CURRENT_BINARY_DIR}/grpc EXCLUDE_FROM_ALL)

+  message(STATUS "Using gRPC via add_subdirectory.")

+  

+  # After using add_subdirectory, we can now use the grpc targets directly from

+  # this build.

+  set(_PROTOBUF_LIBPROTOBUF libprotobuf)

+  set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)

+  set(_GRPC_GRPCPP_UNSECURE grpc++_unsecure)

+  set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)

+else()

+  # This branch assumes that gRPC and all its dependencies are already installed

+  # on this system, so they can be located by find_package().

+

+  # Find Protobuf installation

+  # Looks for protobuf-config.cmake file installed by Protobuf's cmake installation.

+  set(protobuf_MODULE_COMPATIBLE TRUE)

+  find_package(Protobuf CONFIG REQUIRED)

+  message(STATUS "Using protobuf ${protobuf_VERSION}")

 

-set(_PROTOBUF_LIBPROTOBUF protobuf::libprotobuf)

-set(_PROTOBUF_PROTOC $<TARGET_FILE:protobuf::protoc>)

+  set(_PROTOBUF_LIBPROTOBUF protobuf::libprotobuf)

+  set(_PROTOBUF_PROTOC $<TARGET_FILE:protobuf::protoc>)

 

-# Find gRPC installation

-# Looks for gRPCConfig.cmake file installed by gRPC's cmake installation.

-find_package(gRPC CONFIG REQUIRED)

-message(STATUS "Using gRPC ${gRPC_VERSION}")

+  # Find gRPC installation

+  # Looks for gRPCConfig.cmake file installed by gRPC's cmake installation.

+  find_package(gRPC CONFIG REQUIRED)

+  message(STATUS "Using gRPC ${gRPC_VERSION}")

 

-# gRPC C++ plugin

-set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:gRPC::grpc_cpp_plugin>)

+  set(_GRPC_GRPCPP_UNSECURE gRPC::grpc++_unsecure)

+  set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:gRPC::grpc_cpp_plugin>)

+endif()

 

 # Proto file

 get_filename_component(hw_proto "../../protos/helloworld.proto" ABSOLUTE)

@@ -74,6 +107,6 @@ foreach(_target
     ${hw_proto_srcs}

     ${hw_grpc_srcs})

   target_link_libraries(${_target}

-    ${_PROTOBUF_LIBPROTOBUF}

-    gRPC::grpc++_unsecure)

+    ${_GRPC_GRPCPP_UNSECURE}

+    ${_PROTOBUF_LIBPROTOBUF})

 endforeach()