ceph/src/jaegertracing/jaeger-client-cpp/cmake/Findnlohmann_json.cmake

   1 # - Try to find nlohmann_json
   2 #
   3 # The following variables are optionally searched for defaults
   4 #  nlohmann_json_ROOT_DIR:            Base directory where all GLOG components are found
   5 #
   6 # The following are set after configuration is done:
   7 #  nlohmann_json_FOUND
   8 #  nlohmann_json_INCLUDE_DIRS
   9 #  nlohmann_json_LIBRARIES
  10
  11 include(FindPackageHandleStandardArgs)
  12
  13 # only look in default directories
  14 set(nlohmann_json_INCLUDE_NAME "nlohmann/json.hpp")
  15
  16 find_path(nlohmann_json_INCLUDE_DIR
  17     NAMES
  18         nlohmann/json.hpp
  19     PATHS /usr/local/include
  20           /usr/include)
  21
  22 if (NOT nlohmann_json_INCLUDE_DIR)
  23         set(nlohmann_json_INCLUDE_NAME "json.hpp")
  24         find_path(
  25                 nlohmann_json_INCLUDE_DIR
  26                 NAMES "${nlohmann_json_INCLUDE_NAME}"
  27         )
  28 endif()
  29
  30
  31 # Version detection. Unfortunately the header doesn't expose a proper version
  32 # define.
  33 if (nlohmann_json_INCLUDE_DIR AND nlohmann_json_INCLUDE_NAME)
  34         file(READ "${nlohmann_json_INCLUDE_DIR}/${nlohmann_json_INCLUDE_NAME}" NL_HDR_TXT LIMIT 1000)
  35         if (NL_HDR_TXT MATCHES "version ([0-9]+\.[0-9]+\.[0-9]+)")
  36                 set(nlohmann_json_VERSION "${CMAKE_MATCH_1}")
  37         endif()
  38 endif()
  39
  40 set(nlohmann_json_VERSION "${nlohmann_json_VERSION}" CACHE STRING "nlohmann header version")
  41
  42 # handle the QUIETLY and REQUIRED arguments and set nlohmann_json_FOUND to TRUE
  43 # if all listed variables are TRUE, hide their existence from configuration view
  44 include(FindPackageHandleStandardArgs)
  45 find_package_handle_standard_args(
  46         nlohmann_json
  47         REQUIRED_VARS nlohmann_json_INCLUDE_DIR nlohmann_json_INCLUDE_NAME
  48         VERSION_VAR nlohmann_json_VERSION)
  49
  50 if(nlohmann_json_FOUND AND NOT (TARGET nlohmann_json))
  51   add_library(nlohmann_json SHARED IMPORTED)
  52   set_target_properties(nlohmann_json PROPERTIES
  53       INTERFACE_INCLUDE_DIRECTORIES "${nlohmann_json_INCLUDE_DIR}"
  54   )
  55 endif()