grpc/cmake/ssl.cmake

# Copyright 2017 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.

# The CMakeLists.txt for BoringSSL doesn't propagate include directories
# transitively so `_gRPC_SSL_INCLUDE_DIR` should be set for gRPC
# to find header files.

if(gRPC_SSL_PROVIDER STREQUAL "module")
  if(NOT BORINGSSL_ROOT_DIR)
    set(BORINGSSL_ROOT_DIR ${CMAKE_CURRENT_SOURCE_DIR}/third_party/boringssl-with-bazel)
  endif()

  if(EXISTS "${BORINGSSL_ROOT_DIR}/CMakeLists.txt")
    if(CMAKE_GENERATOR MATCHES "Visual Studio")
      if(CMAKE_VERSION VERSION_LESS 3.13)
        # Visual Studio build with assembly optimizations is broken for older
        # version of CMake (< 3.13).
        message(WARNING "Disabling SSL assembly support because CMake version ${CMAKE_VERSION} is too old (less than 3.13)")
        set(OPENSSL_NO_ASM ON)
      else()
        # If we're using a new enough version of CMake, make sure that the
        # NASM assembler can be found.
        include(CheckLanguage)
        check_language(ASM_NASM)
        if(NOT CMAKE_ASM_NASM_COMPILER)
          message(WARNING "Disabling SSL assembly support because NASM could not be found")
          set(OPENSSL_NO_ASM ON)
        endif()
      endif()
    endif()

    add_subdirectory(${BORINGSSL_ROOT_DIR} third_party/boringssl-with-bazel)
    if(TARGET ssl)
      set(_gRPC_SSL_LIBRARIES ssl crypto)
      set(_gRPC_SSL_INCLUDE_DIR ${BORINGSSL_ROOT_DIR}/src/include)
      if(gRPC_INSTALL AND _gRPC_INSTALL_SUPPORTED_FROM_MODULE)
        install(TARGETS ssl crypto EXPORT gRPCTargets
          RUNTIME DESTINATION ${gRPC_INSTALL_BINDIR}
          LIBRARY DESTINATION ${gRPC_INSTALL_LIBDIR}
          ARCHIVE DESTINATION ${gRPC_INSTALL_LIBDIR})
      endif()
    endif()
  else()
    message(WARNING "gRPC_SSL_PROVIDER is \"module\" but BORINGSSL_ROOT_DIR is wrong")
  endif()
  if(gRPC_INSTALL AND NOT _gRPC_INSTALL_SUPPORTED_FROM_MODULE)
    message(WARNING "gRPC_INSTALL will be forced to FALSE because gRPC_SSL_PROVIDER is \"module\" and CMake version (${CMAKE_VERSION}) is less than 3.13.")
    set(gRPC_INSTALL FALSE)
  endif()
elseif(gRPC_SSL_PROVIDER STREQUAL "package")
  # OpenSSL installation directory can be configured by setting OPENSSL_ROOT_DIR
  # We expect to locate OpenSSL using the built-in cmake module as the openssl
  # project itself does not provide installation support in its CMakeLists.txt
  # See https://cmake.org/cmake/help/v3.6/module/FindOpenSSL.html
  find_package(OpenSSL REQUIRED)
  
  if(TARGET OpenSSL::SSL)
    set(_gRPC_SSL_LIBRARIES OpenSSL::SSL OpenSSL::Crypto)
  else()
    set(_gRPC_SSL_LIBRARIES ${OPENSSL_LIBRARIES})
  endif()
  set(_gRPC_SSL_INCLUDE_DIR ${OPENSSL_INCLUDE_DIR})
  
  set(_gRPC_FIND_SSL "if(NOT OPENSSL_FOUND)\n  find_package(OpenSSL)\nendif()")
endif()