[PATCH] D42768: AST: add an extension to support SwiftCC on MS ABI

[Richard Smith - zygoloid via Phabricator via cfe-commits]

rsmith added a comment.

The Itanium C++ ABI specifies a convention of using the source-level syntax in the mangling of vendor extensions. This gives a fairly natural naming convention for such extensions. That would suggest that the identifier to use here is `__swiftcall__`, not `__swift_cc` / `__Swift`. Given that the MS ABI mangles return types even for non-template functions, one consistent place to put this marker would be on the return type. That is, mangle `__attribute__((__swiftcall__)) T f(...)` as if it were `__swiftcall__<T> f(...)`, and likewise for function pointer types.


Repository:
  rC Clang

https://reviews.llvm.org/D42768