This patch implements the forwarding to frozen C++03 headers as discussed in https://discourse.llvm.org/t/rfc-freezing-c-03-headers-in-libc. In the RFC, we initially proposed selecting the right headers from the Clang driver, however consensus seemed to steer towards handling this in the library itself. This patch implements that direction. At a high level, the changes basically amount to making each public header look like this: ``` // inside <vector> #ifdef _LIBCPP_CXX03_LANG # include <__cxx03/vector> #else // normal <vector> content #endif ``` In most cases, public headers are simple umbrella headers so there isn't much code in the #else branch. In other cases, the #else branch contains the actual implementation of the header.
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.