Fix nlohmann_json package dependency (#1017)

CMakeLists.txt

@@ -159,12 +159,16 @@ option(WITH_PROMETHEUS "Whether to include the Prometheus Client in the SDK"
 option(WITH_ELASTICSEARCH
  "Whether to include the Elasticsearch Client in the SDK" OFF)
 
+option(WITH_ZPAGES "Whether to include the Zpages Server in the SDK" OFF)
+
 option(WITH_JAEGER "Whether to include the Jaeger exporter" OFF)
 
 option(WITH_NO_GETENV "Whether the platform supports environment variables" OFF)
 
 option(BUILD_TESTING "Whether to enable tests" ON)
 
+option(BUILD_W3CTRACECONTEXT_TEST "Whether to build w3c trace context" OFF)
+
 if(WITH_NO_GENENV)
  add_definitions(-DNO_GETENV)
 endif()
@@ -249,29 +253,41 @@ endif()
 # GNUInstallDirs.
 include(GNUInstallDirs)
 
-if(NOT WITH_API_ONLY)
+if((NOT WITH_API_ONLY)
+ OR WITH_ELASTICSEARCH
+ OR WITH_ZIPKIN
+ OR WITH_OTLP
+ OR WITH_OTLP_HTTP
+ OR WITH_ZPAGES
+ OR BUILD_W3CTRACECONTEXT_TEST
+ OR WITH_ETW)
  # nlohmann_json package is required for most SDK build configurations
  find_package(nlohmann_json QUIET)
  if(NOT nlohmann_json_FOUND)
- message("Using local nlohmann::json from submodule")
- set(JSON_BuildTests
- OFF
- CACHE INTERNAL "")
- set(JSON_Install
- ON
- CACHE INTERNAL "")
- if(EXISTS ${PROJECT_SOURCE_DIR}/third_party/nlohmann-json)
- # This option allows to link nlohmann_json::nlohmann_json target
- add_subdirectory(${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)
+ if(EXISTS ${PROJECT_SOURCE_DIR}/.git)
+ message("Trying to use local nlohmann::json from submodule")
+ set(JSON_BuildTests
+ OFF
+ CACHE INTERNAL "")
+ set(JSON_Install
+ ON
+ CACHE INTERNAL "")
+ if(EXISTS ${PROJECT_SOURCE_DIR}/third_party/nlohmann-json/CMakeLists.txt)
+ # This option allows to link nlohmann_json::nlohmann_json target
+ add_subdirectory(${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()
+ message(
+ FATAL_ERROR
+ "\nnlohmann_json package was not found. Please either provide it manually or clone with submodules. "
+ "To initialize, fetch and checkout any nested submodules, you can use the following command:\n"
+ "git submodule update --init --recursive")
+ endif()
  else()
- message(
- FATAL_ERROR
- "\nnlohmann_json package was not found. Please either provide it manually or clone with submodules. "
- "To initialize, fetch and checkout any nested submodules, you can use the following command:\n"
- "git submodule update --init --recursive")
+ # Let's fail with default find_package error
+ find_package(nlohmann_json REQUIRED)
  endif()
  else()
  message("Using external nlohmann::json")

ext/src/CMakeLists.txt

@@ -1,2 +1,4 @@
-add_subdirectory(zpages)
+if(WITH_ZPAGES)
+ add_subdirectory(zpages)
+endif()
 add_subdirectory(http/client/curl)

ext/test/CMakeLists.txt

@@ -1,3 +1,7 @@
-add_subdirectory(zpages)
+if(WITH_ZPAGES)
+ add_subdirectory(zpages)
+endif()
 add_subdirectory(http)
-add_subdirectory(w3c_tracecontext_test)
+if(BUILD_W3CTRACECONTEXT_TEST)
+ add_subdirectory(w3c_tracecontext_test)
+endif()