opentelemetry-cpp/cmake/nlohmann-json.cmake

95 lines
3.3 KiB
CMake

# Copyright The OpenTelemetry Authors
# SPDX-License-Identifier: Apache-2.0
#
# The dependency on nlohmann_json can be provided different ways. By order of
# decreasing priority, options are:
#
# 1 - Search for a nlohmann_json package
#
# Packages installed on the local machine are used if found.
#
# The nlohmann_json dependency is not installed, as it already is.
#
# 2 - Search for a nlohmann_json git submodule
#
# When git submodule is used, the nlohmann_json code is located in:
# third_party/nlohmann-json
#
# The nlohmann_json dependency is installed, by building the sub directory with
# JSON_Install=ON
#
# 3 - Download nlohmann_json from github
#
# Code from the development branch is used, unless a specific release tag is
# provided in variable ${nlohmann-json}
#
# The nlohmann_json dependency is installed, by building the downloaded code
# with JSON_Install=ON
#
# nlohmann_json package is required for most SDK build configurations
find_package(nlohmann_json QUIET)
set(nlohmann_json_clone FALSE)
if(nlohmann_json_FOUND)
message(STATUS "nlohmann::json dependency satisfied by: package")
elseif(TARGET nlohmann_json)
message(STATUS "nlohmann::json is already added as a CMake target!")
elseif(EXISTS ${PROJECT_SOURCE_DIR}/.git
AND EXISTS
${PROJECT_SOURCE_DIR}/third_party/nlohmann-json/CMakeLists.txt)
message(STATUS "nlohmann::json dependency satisfied by: git submodule")
set(JSON_BuildTests
OFF
CACHE INTERNAL "")
set(JSON_Install
ON
CACHE INTERNAL "")
# This option allows to link nlohmann_json::nlohmann_json target
add_subdirectory(${PROJECT_SOURCE_DIR}/third_party/nlohmann-json)
# This option allows to add header to include directories
include_directories(
${PROJECT_SOURCE_DIR}/third_party/nlohmann-json/single_include)
else()
if("${nlohmann-json}" STREQUAL "")
set(nlohmann-json "develop")
endif()
message(STATUS "nlohmann::json dependency satisfied by: github download")
set(nlohmann_json_clone TRUE)
include(ExternalProject)
ExternalProject_Add(
nlohmann_json_download
PREFIX third_party
GIT_REPOSITORY https://github.com/nlohmann/json.git
GIT_TAG "${nlohmann-json}"
UPDATE_COMMAND ""
CMAKE_ARGS -DCMAKE_INSTALL_PREFIX=${CMAKE_INSTALL_PREFIX}
-DJSON_BuildTests=OFF -DJSON_Install=ON
-DCMAKE_BUILD_TYPE=${CMAKE_BUILD_TYPE}
TEST_AFTER_INSTALL 0
DOWNLOAD_NO_PROGRESS 1
LOG_CONFIGURE 1
LOG_BUILD 1
LOG_INSTALL 1)
ExternalProject_Get_Property(nlohmann_json_download INSTALL_DIR)
set(NLOHMANN_JSON_INCLUDE_DIR
${INSTALL_DIR}/src/nlohmann_json_download/single_include)
add_library(nlohmann_json_ INTERFACE)
target_include_directories(
nlohmann_json_ INTERFACE "$<BUILD_INTERFACE:${NLOHMANN_JSON_INCLUDE_DIR}>"
"$<INSTALL_INTERFACE:include>")
add_dependencies(nlohmann_json_ nlohmann_json_download)
add_library(nlohmann_json::nlohmann_json ALIAS nlohmann_json_)
if(OPENTELEMETRY_INSTALL)
install(
TARGETS nlohmann_json_
EXPORT "${PROJECT_NAME}-third_party_nlohmann_json_target"
RUNTIME DESTINATION ${CMAKE_INSTALL_BINDIR}
LIBRARY DESTINATION ${CMAKE_INSTALL_LIBDIR}
ARCHIVE DESTINATION ${CMAKE_INSTALL_LIBDIR}
COMPONENT third_party_nlohmann_json)
endif()
endif()