[PATCH] D36501: Add flag to request Clang is ABI-compatible with older versions of itself

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

rsmith added a comment.

In https://reviews.llvm.org/D36501#852864, @rjmccall wrote:

> The only thing I would say here is that, as a platform vendor, I would like the ability to opt in to ABI fixes that aren't in my base-line version.  In particular, we're generally more aggressive about taking C++ ABI fixes on Darwin when there's a strong argument that the impact is likely to be low, like for some of these indirect-ABI cases that only make a difference for classes with e.g. only deleted copy/move constructors but a trivial destructor.


I don't think the idea of a base-line version matches with the direction of the patch, and I've removed the part of the patch that has a base-line Clang version for PS4. I think that if your platform ABI dictates that you do thing X differently from, say, the x86_64 psABI or the Itanium C++ ABI, then that's simply part of your platform ABI, and not a clang compatibility feature, regardless of whether the historical reason your platform ABI made that choice was due to clang compatibility.


Repository:
  rL LLVM

https://reviews.llvm.org/D36501