A lot of files transitively include Expr.h, because it was
included from SILInstruction.h, SILLocation.h and SILDeclRef.h.
However in reality most of these files don't do anything
with Exprs, especially not anything in IRGen or the SILOptimizer.
Now we're down to 171 files in the frontend which depend on
Expr.h, which is still a lot but much better than before.
Two of them are user-facing, with the following sort of message:
If you're seeing a crash here, check that your SDK and
dependencies match the versions used to build 'SwiftLib'
Prompted by rdar://problem/28282310, which took a while to figure out.
The added test case is a simplified version of the issue. (Obviously
we'd prefer to not crash here, but that's hard---there's an inherited
conformance that's no longer valid, and there may be generic types
depending on that conformance.)
llvm::Optional lives in "llvm/ADT/Optional.h". Like Clang, we can get
Optional in the 'swift' namespace by including "swift/Basic/LLVM.h".
We're now fully switched over to llvm::Optional!
Swift SVN r22477
AnyFunctionRef is a universal function reference that can wrap all AST nodes
that represent functions and exposes a common interface to them. Use it in two
places in SIL where CapturingExpr was used previously.
AnyFunctionRef allows further simplifications in other places, but these will
be done separately.
Swift SVN r8239
This should help give a slightly better experience for out-of-order
type checking issues until we manage to make type checking
order-independent. <rdar://problem/14702636>.
Swift SVN r7149
