FetchGRPC.cmake

# Copyright 2018 gRPC authors.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
#     http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
#
# cmake build file for C++ route_guide example.
# Assumes protobuf and gRPC have been installed using cmake.
# 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 3.15)

if(MSVC)
  add_definitions(-D_WIN32_WINNT=0x600)
endif()

find_package(Threads REQUIRED)

# disable a lot of stuff
set(gRPC_BUILD_TESTS OFF)
set(gRPC_BUILD_CSHARP_EXT OFF)
set(gRPC_BUILD_GRPC_CSHARP_PLUGIN OFF)
set(gRPC_BUILD_GRPC_PYTHON_PLUGIN OFF)
set(gRPC_BUILD_GRPC_RUBY_PLUGIN OFF)
set(gRPC_BUILD_GRPC_PHP_PLUGIN OFF)
set(gRPC_BUILD_GRPC_OBJECTIVE_C_PLUGIN OFF)
set(gRPC_BUILD_GRPC_NODE_PLUGIN OFF)
set(protobuf_BUILD_TESTS OFF)
set(vGRPC_TAG_VERSION_OF_YOUR_CHOICE "v1.38.0")

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(_REFLECTION grpc++_reflection)
  if(CMAKE_CROSSCOMPILING)
    find_program(_PROTOBUF_PROTOC protoc)
  else()
    set(_PROTOBUF_PROTOC $<TARGET_FILE:protobuf::protoc>)
  endif()
  set(_GRPC_GRPCPP grpc++)
  if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
  else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
  endif()
elseif(GRPC_FETCHCONTENT)
  # Another way is to use CMake's FetchContent module to clone gRPC at
  # configure time. This makes gRPC's source code available to your project,
  # similar to a git submodule.
  message(STATUS "Using gRPC via add_subdirectory (FetchContent).")
  include(FetchContent)
  FetchContent_Declare(
    grpc
    GIT_REPOSITORY https://github.com/grpc/grpc.git
    # when using gRPC, you will actually set this to an existing tag, such as
    # v1.25.0, v1.26.0 etc..
    # For the purpose of testing, we override the tag used to the commit
    # that's currently under test.
    GIT_TAG        vGRPC_TAG_VERSION_OF_YOUR_CHOICE
    GIT_SHALLOW     1)
  FetchContent_MakeAvailable(grpc)

  # Since FetchContent uses add_subdirectory under the hood, we can use
  # the grpc targets directly from this build.
  set(_PROTOBUF_LIBPROTOBUF libprotobuf)
  set(_REFLECTION grpc++_reflection)
  set(_PROTOBUF_PROTOC $<TARGET_FILE:protoc>)
  set(_GRPC_GRPCPP grpc++)
  if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
  else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:grpc_cpp_plugin>)
  endif()

  ## disable more unused stuff
  set_target_properties(
    zlibstatic
    libprotobuf
    libprotoc
    grpc_plugin_support
    grpc_cpp_plugin
    upb
    address_sorting
    absl_log_severity
    absl_raw_logging_internal
    absl_bad_optional_access
    absl_spinlock_wait
    absl_throw_delegate
    absl_base
    absl_malloc_internal
    absl_debugging_internal
    absl_stacktrace
    absl_strings_internal
    absl_int128
    absl_strings
    absl_demangle_internal
    absl_symbolize
    absl_str_format_internal
    absl_cord
    absl_status
    absl_civil_time
    absl_time_zone
    absl_time
    absl_graphcycles_internal
    absl_synchronization
    gpr
    absl_exponential_biased
    absl_hashtablez_sampler
    absl_raw_hash_set
    absl_wyhash
    absl_city
    absl_bad_variant_access
    absl_hash
    absl_statusor
    c-ares
    re2
    ssl
    crypto
    gen_hpack_tables
    gen_legal_metadata_characters
    check_epollexclusive
    grpcpp_channelz
    gen_percent_encoding_tables
    grpc++_error_details
    grpc_unsecure
    grpc++_alts
    grpc++_unsecure
    absl_strerror
    absl_periodic_sampler
    absl_scoped_set_env
    absl_examine_stack
    absl_failure_signal_handler
    absl_leak_check
    absl_leak_check_disable
    absl_flags_program_name
    absl_flags_config
    absl_flags_commandlineflag_internal
    absl_flags_commandlineflag
    absl_flags_private_handle_accessor
    absl_flags_reflection
    absl_flags_marshalling
    absl_flags_internal
    absl_flags
    absl_flags_usage_internal
    absl_flags_usage
    absl_flags_parse
    absl_random_seed_gen_exception
    absl_random_internal_seed_material
    absl_random_internal_platform
    absl_random_internal_randen_slow
    absl_random_internal_randen_hwaes_impl
    absl_random_internal_randen_hwaes
    absl_random_internal_randen
    absl_random_internal_pool_urbg
    absl_random_distributions
    absl_random_seed_sequences
    absl_random_internal_distribution_test_util
    absl_bad_any_cast_impl
    acountry
    adig
    ahost
    libprotobuf-lite
    testing
    search_test
    regexp_test
    possible_match_test
    mimics_pcre_test
    parse_test
    required_prefix_test
    filtered_re2_test
    compile_test
    re2_arg_test
    charclass_test
    exhaustive1_test
    re2_test
    simplify_test
    string_generator_test
    dfa_test
    exhaustive3_test
    exhaustive2_test
    exhaustive_test
    regexp_benchmark
    random_test
    set_test
    bssl
    zlib
    example64
    minigzip
    example
    minigzip64
    grpc
    grpc++
    protoc
    grpc++_reflection
    PROPERTIES
    CXX_CLANG_TIDY ""
    CXX_INCLUDE_WHAT_YOU_USE ""
    EXCLUDE_FROM_ALL 1
  )
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(_REFLECTION gRPC::grpc++_reflection)
  if(CMAKE_CROSSCOMPILING)
    find_program(_PROTOBUF_PROTOC protoc)
  else()
    set(_PROTOBUF_PROTOC $<TARGET_FILE:protobuf::protoc>)
  endif()

  # 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}")

  set(_GRPC_GRPCPP gRPC::grpc++)
  if(CMAKE_CROSSCOMPILING)
    find_program(_GRPC_CPP_PLUGIN_EXECUTABLE grpc_cpp_plugin)
  else()
    set(_GRPC_CPP_PLUGIN_EXECUTABLE $<TARGET_FILE:gRPC::grpc_cpp_plugin>)
  endif()
endif()