2 files changed, 35 insertions, 0 deletions
diff --git a/Source/Checks/cm_c11_thread_local.c b/Source/Checks/cm_c11_thread_local.c
new file mode 100644
index 0000000..ab780f2
--- /dev/null
+++ b/Source/Checks/cm_c11_thread_local.c
@@ -0,0 +1,2 @@
+_Thread_local int i = 42;
+int main(void) { return 0; }
diff --git a/Source/Checks/cm_c11_thread_local.cmake b/Source/Checks/cm_c11_thread_local.cmake
new file mode 100644
index 0000000..6b8d10b
--- /dev/null
+++ b/Source/Checks/cm_c11_thread_local.cmake
@@ -0,0 +1,33 @@
+set(CMake_C11_THREAD_LOCAL_BROKEN 0)
+if(CMAKE_CXX_COMPILER_ID MATCHES "GNU" AND CMAKE_C11_STANDARD_COMPILE_OPTION)
+  if(NOT DEFINED CMake_C11_THREAD_LOCAL_WORKS)
+    message(STATUS "Checking if compiler supports C11 _Thread_local")
+    try_compile(CMake_C11_THREAD_LOCAL_WORKS
+      ${CMAKE_CURRENT_BINARY_DIR}
+      ${CMAKE_CURRENT_LIST_DIR}/cm_c11_thread_local.c
+      CMAKE_FLAGS -DCMAKE_C_STANDARD=11
+      OUTPUT_VARIABLE OUTPUT
+      )
+    if(CMake_C11_THREAD_LOCAL_WORKS AND "${OUTPUT}" MATCHES "error: expected '=', ',', ';', 'asm' or '__attribute__' before 'int'")
+      set_property(CACHE CMake_C11_THREAD_LOCAL_WORKS PROPERTY VALUE 0)
+    endif()
+    if(CMake_C11_THREAD_LOCAL_WORKS)
+      message(STATUS "Checking if compiler supports C11 _Thread_local - yes")
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeOutput.log
+        "Determining if compiler supports C11 _Thread_local passed with the following output:\n"
+        "${OUTPUT}\n"
+        "\n"
+        )
+    else()
+      message(STATUS "Checking if compiler supports C11 _Thread_local - no")
+      file(APPEND ${CMAKE_BINARY_DIR}${CMAKE_FILES_DIRECTORY}/CMakeError.log
+        "Determining if compiler supports C11 _Thread_local failed with the following output:\n"
+        "${OUTPUT}\n"
+        "\n"
+        )
+    endif()
+  endif()
+  if(NOT CMake_C11_THREAD_LOCAL_WORKS)
+    set(CMake_C11_THREAD_LOCAL_BROKEN 1)
+  endif()
+endif()