Previously we would only add @_disfavoredOverload if the only type
changed was the return type, because in any other case it is unambiguous
which overload to call. However it is still ambiguous when storing the
function as a value rather than calling the function, unless explicit
type annotations are used.
To avoid breaking any existing code, this patch adds
@_disfavoredOverload to every overload generated by @_SwiftifyImport.
rdar://151206394
Usage of Span was temporarily behind an experimental feature flag. Now
that SE-0447 has been accepted, remove the experimental feature flag and
allow Span usage everywhere.
Implements rdar://144819992.
* Import __counted_by for function return values
Instead of simply passing a parameter index to _SwiftifyInfo, the
_SwiftifyExpr enum is introduced. It currently has two cases:
- .param(index: Int), corresponding to the previous parameter index
- .return, corresponding to the function's return value.
ClangImporter is also updated to pass this new information along to
_SwiftifyImport, allowing overloads with buffer pointer return types to
be generated. The swiftified return values currently return Span when
the return value is marked as nonescaping, despite this not being sound.
This is a bug that will be fixed in the next commit, as the issue is
greater than just for return values.
* Fix Span variant selection
There was an assumption that all converted pointers were either
converted to Span-family pointers, or UnsafeBufferPointer-family
pointers. This was not consistently handled, resulting in violating the
`assert(nonescaping)` assert when the two were mixed. This patch removes
the Variant struct, and instead each swiftified pointer separately
tracks whether it should map to Span or UnsafeBufferPointer.
This also fixes return pointers being incorrectly mapped to Span when
marked as nonescaping.
This makes it possible to mark a pointer with __sized_by when the
pointee type definition is not included. The wrapper function has the
same interface as if the parameter were a void pointer, since the stdlib
has no `OpaqueBufferPointer` type.
* use swift-ide-test for checking interop signatures
* add xfail test for Span + Optional combo (Optional requires Escapable)
* Make pointer bounds non-experimental
* Rename @PointerBounds to @_SwiftifyImport
* Rename filenames containing PointerBounds
* Add _PointerParam exception to stdlib ABI test
* Add _PointerParam to stdlib API changes
* Rename _PointerParam to _SwiftifyInfo
