[PATCH] D26540: [Sema] Accept and ignore the leaf attribute

[Aaron Ballman via cfe-commits]

aaron.ballman added a comment.

In https://reviews.llvm.org/D26540#593433, @phosek wrote:

> That makes sense for diagnostics, but this attribute is only an optimization hint, so compiler should be allowed to ignore it. I can take a look how difficult it'd be to actually implement this attribute, but I don't think it's Sema-only attribute. I don't know if there's a matching IR function attribute; it seems like `readonly` attribute has similar effect but I'd need to take a look at the exact semantics.


The compiler does ignore it; it even tells you it's ignoring it. ;-) There are other optimization-only attributes we don't support, similarly (such as `__attribute__((optimize))`).

Hopefully the attribute is something we can fully implement, but if it's not and this attribute isn't used by common system headers, I'd be opposed to silently ignoring it rather than vocally ignoring it.


Repository:
  rL LLVM

https://reviews.llvm.org/D26540