[BUILD] Add a CMake option to disable shared libs (open-telemetry#3095)

* Add a CMake option to disable shared libs

This option is useful to support platforms that do not support
dynamic libraries and `dlopen`.

Author: tobim

CMakeLists.txt

@@ -287,6 +287,10 @@ option(WITH_ASYNC_EXPORT_PREVIEW "Whether to enable async export" OFF)
 option(WITH_METRICS_EXEMPLAR_PREVIEW
        "Whether to enable exemplar within metrics" OFF)
 
+option(OPENTELEMETRY_SKIP_DYNAMIC_LOADING_TESTS
+       "Whether to build test libraries that are always linked as shared libs"
+       OFF)
+
 #
 # Verify options dependencies
 #

api/test/CMakeLists.txt

@@ -10,4 +10,7 @@ add_subdirectory(metrics)
 add_subdirectory(logs)
 add_subdirectory(common)
 add_subdirectory(baggage)
-add_subdirectory(singleton)
+
+if(NOT OPENTELEMETRY_SKIP_DYNAMIC_LOADING_TESTS)
+  add_subdirectory(singleton)
+endif()

examples/plugin/CMakeLists.txt

@@ -2,4 +2,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 add_subdirectory(load)
-add_subdirectory(plugin)
+
+if(NOT OPENTELEMETRY_SKIP_DYNAMIC_LOADING_TESTS)
+  add_subdirectory(plugin)
+endif()