cmake: Allow thread checks to fail and fall back to nothreads
Closes: #2155
git-svn-id: https://svn.apache.org/repos/asf/xerces/c/trunk@1843653 13f79535-47bb-0310-9956-ffa450edef68
diff --git a/cmake/XercesMutexMgrSelection.cmake b/cmake/XercesMutexMgrSelection.cmake
index 2f1d71c..ad69884 100644
--- a/cmake/XercesMutexMgrSelection.cmake
+++ b/cmake/XercesMutexMgrSelection.cmake
@@ -19,12 +19,16 @@
# mutexmgr selection
-option(threads "Threading support" ON)
+set(xerces_thread_default ON)
+find_package(Threads)
+if(NOT TARGET Threads::Threads)
+ set(xerces_thread_default ON)
+endif()
+
+option(threads "Threading support" ${xerces_thread_default})
include(CheckCXXSourceCompiles)
-find_package(Threads REQUIRED)
-
function(thread_test outvar)
set(CMAKE_REQUIRED_LIBRARIES ${CMAKE_REQUIRED_LIBRARIES} ${CMAKE_THREAD_LIBS_INIT})
