--- /dev/null
+# libc++ / libc++abi configuration caches
+
+This directory contains CMake caches for the supported configurations of libc++.
+Some of the configurations are specific to a vendor, others are generic and not
+tied to any vendor.
+
+While we won't explicitly work to break configurations not listed here, any
+configuration not listed here is not explicitly supported. If you use or ship
+libc++ under a configuration not listed here, you should work with the libc++
+maintainers to make it into a supported configuration and add it here.
+
+Similarly, adding any new configuration that's not already covered must be
+discussed with the libc++ maintainers as it entails a maintenance burden.