Add error check for user setting CMAKE_BUILD_TYPE (#2360)

* Add error check for user setting CMAKE_BUILD_TYPE

* fix case where CMAKE_BUILD_TYPE is not set

CMakeLists.txt

@@ -27,6 +27,14 @@ if("${CMAKE_GENERATOR}" STREQUAL "Ninja")
     message(FATAL_ERROR "Ninja generator not supported.")
 endif()
 
+if (CMAKE_BUILD_TYPE)
+    set(RELEASE_TYPES Debug Release RelWithDebInfo MinSizeRel)
+    list(FIND RELEASE_TYPES ${CMAKE_BUILD_TYPE} INDEX_FOUND)
+    if (${INDEX_FOUND} EQUAL -1)
+        message(FATAL_ERROR "CMAKE_BUILD_TYPE must be one of Debug, Release, RelWithDebInfo, or MinSizeRel")
+    endif()
+endif()
+
 include(git_tags)
 include(var_functions)