json/CMakeLists.txt

cmake_minimum_required(VERSION 3.0)

# define the project
project(nlohmann_json VERSION 2.0.0 LANGUAGES CXX)

option(BuildTests "Build the unit tests" ON)

# define project variables
set(JSON_TARGET_NAME ${PROJECT_NAME})
set(JSON_PACKAGE_NAME ${JSON_TARGET_NAME})
set(JSON_TARGETS_FILENAME "${JSON_PACKAGE_NAME}Targets.cmake")
set(JSON_CONFIG_FILENAME "${JSON_PACKAGE_NAME}Config.cmake")
set(JSON_CONFIGVERSION_FILENAME "${JSON_PACKAGE_NAME}ConfigVersion.cmake")
set(JSON_CONFIG_DESTINATION "cmake")
set(JSON_INCLUDE_DESTINATION "include/nlohmann")

# create and configure the library target
add_library(${JSON_TARGET_NAME} INTERFACE)
target_include_directories(${JSON_TARGET_NAME} INTERFACE
  $<BUILD_INTERFACE:${CMAKE_CURRENT_SOURCE_DIR}/src>
  $<INSTALL_INTERFACE:${JSON_INCLUDE_DESTINATION}>)

# create and configure the unit test target
if (BuildTests)
    add_executable(json_unit
        "test/catch.hpp"
        "test/unit.cpp"
    )
    set_target_properties(json_unit PROPERTIES
        CXX_STANDARD 11
        CXX_STANDARD_REQUIRED ON
        COMPILE_DEFINITIONS "$<$<CXX_COMPILER_ID:MSVC>:_SCL_SECURE_NO_WARNINGS>"
        COMPILE_OPTIONS "$<$<CXX_COMPILER_ID:MSVC>:/EHsc;$<$<CONFIG:Release>:/Od>>")
    target_include_directories(json_unit PRIVATE "test")
    target_link_libraries(json_unit ${JSON_TARGET_NAME})
endif()

# generate a config and config version file for the package
include(CMakePackageConfigHelpers)
configure_package_config_file("cmake/config.cmake.in"
    "${CMAKE_CURRENT_BINARY_DIR}/${JSON_CONFIG_FILENAME}"
    INSTALL_DESTINATION ${JSON_CONFIG_DESTINATION})
write_basic_package_version_file("${CMAKE_CURRENT_BINARY_DIR}/${JSON_CONFIGVERSION_FILENAME}"
    VERSION ${PROJECT_VERSION}
    COMPATIBILITY SameMajorVersion)

# export the library target and store build directory in package registry
export(TARGETS ${JSON_TARGET_NAME}
	FILE "${CMAKE_CURRENT_BINARY_DIR}/${JSON_TARGETS_FILENAME}")
export(PACKAGE ${JSON_PACKAGE_NAME})

# install library target and config files
install(TARGETS ${JSON_TARGET_NAME}
	EXPORT ${JSON_PACKAGE_NAME})
install(FILES "src/json.hpp"
	DESTINATION ${JSON_INCLUDE_DESTINATION})
install(EXPORT ${JSON_PACKAGE_NAME}
	FILE ${JSON_TARGETS_FILENAME}
	DESTINATION ${JSON_CONFIG_DESTINATION})
install(FILES "${CMAKE_CURRENT_BINARY_DIR}/${JSON_CONFIG_FILENAME}"
	"${CMAKE_CURRENT_BINARY_DIR}/${JSON_CONFIGVERSION_FILENAME}"
	DESTINATION ${JSON_CONFIG_DESTINATION})