1# 2# Copyright 2017 The Abseil Authors. 3# 4# Licensed under the Apache License, Version 2.0 (the "License"); 5# you may not use this file except in compliance with the License. 6# You may obtain a copy of the License at 7# 8# https://www.apache.org/licenses/LICENSE-2.0 9# 10# Unless required by applicable law or agreed to in writing, software 11# distributed under the License is distributed on an "AS IS" BASIS, 12# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 13# See the License for the specific language governing permissions and 14# limitations under the License. 15# 16 17# Most widely used distributions have cmake 3.5 or greater available as of March 18# 2019. A notable exception is RHEL-7 (CentOS7). You can install a current 19# version of CMake by first installing Extra Packages for Enterprise Linux 20# (https://fedoraproject.org/wiki/EPEL#Extra_Packages_for_Enterprise_Linux_.28EPEL.29) 21# and then issuing `yum install cmake3` on the command line. 22cmake_minimum_required(VERSION 3.5) 23 24# Compiler id for Apple Clang is now AppleClang. 25if (POLICY CMP0025) 26 cmake_policy(SET CMP0025 NEW) 27endif (POLICY CMP0025) 28 29# if command can use IN_LIST 30if (POLICY CMP0057) 31 cmake_policy(SET CMP0057 NEW) 32endif (POLICY CMP0057) 33 34# Project version variables are the empty string if version is unspecified 35if (POLICY CMP0048) 36 cmake_policy(SET CMP0048 NEW) 37endif (POLICY CMP0048) 38 39# option() honor variables 40if (POLICY CMP0077) 41 cmake_policy(SET CMP0077 NEW) 42endif (POLICY CMP0077) 43 44# Set BUILD_TESTING to OFF by default. 45# This must come before the project() and include(CTest) lines. 46OPTION(BUILD_TESTING "Build tests" OFF) 47 48project(absl LANGUAGES CXX VERSION 20210324) 49include(CTest) 50 51# Output directory is correct by default for most build setups. However, when 52# building Abseil as a DLL, it is important to have the DLL in the same 53# directory as the executable using it. Thus, we put all executables in a single 54# /bin directory. 55set(CMAKE_RUNTIME_OUTPUT_DIRECTORY ${CMAKE_BINARY_DIR}/bin) 56 57# when absl is included as subproject (i.e. using add_subdirectory(abseil-cpp)) 58# in the source tree of a project that uses it, install rules are disabled. 59if(NOT CMAKE_SOURCE_DIR STREQUAL PROJECT_SOURCE_DIR) 60 option(ABSL_ENABLE_INSTALL "Enable install rule" OFF) 61else() 62 option(ABSL_ENABLE_INSTALL "Enable install rule" ON) 63endif() 64 65list(APPEND CMAKE_MODULE_PATH 66 ${CMAKE_CURRENT_LIST_DIR}/CMake 67 ${CMAKE_CURRENT_LIST_DIR}/absl/copts 68) 69 70include(CMakePackageConfigHelpers) 71include(GNUInstallDirs) 72include(AbseilDll) 73include(AbseilHelpers) 74 75 76## 77## Using absl targets 78## 79## all public absl targets are 80## exported with the absl:: prefix 81## 82## e.g absl::base absl::synchronization absl::strings .... 83## 84## DO NOT rely on the internal targets outside of the prefix 85 86 87# include current path 88list(APPEND ABSL_COMMON_INCLUDE_DIRS ${CMAKE_CURRENT_SOURCE_DIR}) 89 90if("${CMAKE_CXX_COMPILER_ID}" MATCHES "Clang") 91 set(ABSL_USING_CLANG ON) 92else() 93 set(ABSL_USING_CLANG OFF) 94endif() 95 96# find dependencies 97## pthread 98find_package(Threads REQUIRED) 99 100option(ABSL_USE_EXTERNAL_GOOGLETEST 101 "If ON, Abseil will assume that the targets for GoogleTest are already provided by the including project. This makes sense when Abseil is used with add_subproject." OFF) 102 103option(ABSL_USE_GOOGLETEST_HEAD 104 "If ON, abseil will download HEAD from GoogleTest at config time." OFF) 105 106set(ABSL_GOOGLETEST_DOWNLOAD_URL "" CACHE STRING "If set, download GoogleTest from this URL") 107 108set(ABSL_LOCAL_GOOGLETEST_DIR "/usr/src/googletest" CACHE PATH 109 "If ABSL_USE_GOOGLETEST_HEAD is OFF and ABSL_GOOGLETEST_URL is not set, specifies the directory of a local GoogleTest checkout." 110 ) 111 112if(BUILD_TESTING) 113 ## check targets 114 if (NOT ABSL_USE_EXTERNAL_GOOGLETEST) 115 set(absl_gtest_build_dir ${CMAKE_BINARY_DIR}/googletest-build) 116 if(ABSL_USE_GOOGLETEST_HEAD AND ABSL_GOOGLETEST_DOWNLOAD_URL) 117 message(FATAL_ERROR "Do not set both ABSL_USE_GOOGLETEST_HEAD and ABSL_GOOGLETEST_DOWNLOAD_URL") 118 endif() 119 if(ABSL_USE_GOOGLETEST_HEAD) 120 set(absl_gtest_download_url "https://github.com/google/googletest/archive/master.zip") 121 elseif(ABSL_GOOGLETEST_DOWNLOAD_URL) 122 set(absl_gtest_download_url ${ABSL_GOOGLETEST_DOWNLOAD_URL}) 123 endif() 124 if(absl_gtest_download_url) 125 set(absl_gtest_src_dir ${CMAKE_BINARY_DIR}/googletest-src) 126 else() 127 set(absl_gtest_src_dir ${ABSL_LOCAL_GOOGLETEST_DIR}) 128 endif() 129 include(CMake/Googletest/DownloadGTest.cmake) 130 endif() 131 132 check_target(gtest) 133 check_target(gtest_main) 134 check_target(gmock) 135 136 list(APPEND ABSL_TEST_COMMON_LIBRARIES 137 gtest_main 138 gtest 139 gmock 140 ${CMAKE_THREAD_LIBS_INIT} 141 ) 142endif() 143 144add_subdirectory(absl) 145 146if(ABSL_ENABLE_INSTALL) 147 148 149 # install as a subdirectory only 150 install(EXPORT ${PROJECT_NAME}Targets 151 NAMESPACE absl:: 152 DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}" 153 ) 154 155 configure_package_config_file( 156 CMake/abslConfig.cmake.in 157 "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake" 158 INSTALL_DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}" 159 ) 160 install(FILES "${PROJECT_BINARY_DIR}/${PROJECT_NAME}Config.cmake" 161 DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}" 162 ) 163 164 # Abseil only has a version in LTS releases. This mechanism is accomplished 165 # Abseil's internal Copybara (https://github.com/google/copybara) workflows and 166 # isn't visible in the CMake buildsystem itself. 167 if(absl_VERSION) 168 write_basic_package_version_file( 169 "${PROJECT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake" 170 COMPATIBILITY ExactVersion 171 ) 172 173 install(FILES "${PROJECT_BINARY_DIR}/${PROJECT_NAME}ConfigVersion.cmake" 174 DESTINATION "${CMAKE_INSTALL_LIBDIR}/cmake/${PROJECT_NAME}" 175 ) 176 endif() # absl_VERSION 177 178 install(DIRECTORY absl 179 DESTINATION ${CMAKE_INSTALL_INCLUDEDIR} 180 FILES_MATCHING 181 PATTERN "*.inc" 182 PATTERN "*.h" 183 PATTERN "copts" EXCLUDE 184 PATTERN "testdata" EXCLUDE 185 ) 186endif() # ABSL_ENABLE_INSTALL 187