An RFC has been posted to the Clang developer mailing list discussing
support for the -fexec-charset option.

http://lists.llvm.org/pipermail/cfe-dev/2020-December/067354.html

Jens, the RFC has a nice break down of places where string literals
appear and what the conversion requirements are for them. It might be
useful input to your planned paper that we discussed in yesterday's SG16
telecon with regard to what phase of translation those conversions occur in.

Tom.