Introduce a marker protocol SendableMetatype that is used to indicate
when the metatype of a type will conform to Sendable. Specifically,
`T: SendableMetatype` implies `T.Type: Sendable`. When strict
metatype sendability is enabled, metatypes are only sendable when `T:
SendableMetatype`.
All nominal types implicitly conform to `SendableMetatype`, as do the
various builtin types, function types, etc. The `Sendable` marker
protocol now inherits from `SendableMetatype`, so that `T: Sendable`
implies `T.Type: Sendable`.
Thank you Slava for the excellent idea!
If this function is inlined, the optimizer can shrink the lifetime of the `args` parameter. This would deallocate the passed arguments (e.g. `NSString`s) before the are used in the closure.
Support adding safe wrappers for APIs returning std::span depending on
the this object. This also fixes an issue for APIs with 0 parameters.
rdar://139074571
This PR adds basic support for storing lifetime dependence information,
transform Span return types, and generate lifetime annotations.
rdar://139074571
Move the backtracing code into a new Runtime module. This means renaming
the Swift Runtime's CMake target because otherwise there will be a name
clash.
rdar://124913332
Doc comments for DiscontiguousSlice, MutableCollection, RangeSet, and
RangeReplaceableCollection all refer to a Collection method subranges(where:)
which is intended to return a RangeSet of matching ranges. I believe this is
likely an old or formerly-contemplated spelling of the method now known as
indices(where:). This commit changes "subranges" to "indices".
* 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.
