That is, if there's a problem with a witness, and the witness comes
from a different extension from the conformance (or the original type,
when the conformance is on an extension), put the main diagnostic on
the conformance, with a note on the witness. This involves some
shuffling and rephrasing of existing diagnostics too.
There's a few reasons for this change:
- More context. It may not be obvious why a declaration in file
A.swift needs to be marked 'public' if you can't see the conformance
in B.swift.
- Better locations for imported declarations. If you're checking a
conformance in a source file but the witness came from an imported
module, it's better to put the diagnostic on the part you have
control over. (This is especially true in Xcode, which can't display
diagnostics on imported declarations in the source editor.)
- Plays better with batch mode. Without this change, you can have
diagnostics being reported in file A.swift that are tied to a
conformance declared in file B.swift. Of course the contents of
A.swift also affect the diagnostic, but compiling A.swift on its
own wouldn't produce the diagnostic, and so putting it there is
problematic.
The change does in some cases make for a worse user experience,
though; if you just want to apply the changes and move on, the main
diagnostic isn't in the "right place". It's the note that has the info
and possible fix-it. It's also a slightly more complicated
implementation.
By formalizing ReferenceOwnership as a diagnostic argument kind, we get
less boilerplate, better type safety, better output consistency, and
last but not least: future proofing.
...and fix places where it was being used inappropriately.
- Don't use 'open' on non-class members in the importer.
- Use the existing 'copyFormalAccessFrom' instead of an ad hoc version
for synthesized typealiases for protocol conformances. (This can
change 'internal' down to 'fileprivate', but only where the
enclosing type was already 'private' or 'fileprivate'.)
- Fix 'copyFormalAccessFrom' to not copy '@usableFromInline' onto
declarations that don't support it (namely, the above typealiases).
This should have no visible effect in practice.
Since 'private' means "limit to the enclosing scope (and extensions
thereof)", putting it on a member means that the member can't be
accessed everywhere the type might show up. That's normally a good
thing, but it's not the desired effect for synthesized members used
for derived conformances, and when it comes to class initializers this
actually violates AST invariants.
rdar://problem/39478298
We need to be able to find which conformances need to be
declared/constructed without forcing extensions to be completely
validated. This is important for both SR-6569 and
rdar://problem/36499373. The former due to the source-level recursion,
and the latter because implied conformances weren't always
constructed (but are needed for good diagnostics).
They weren't always constructed because:
1. ConformanceLookupTable's updateLookupTable on an early stage (before
implied conformances are found) triggers extension
validation *before* constructing any conformances, but *after*
updating the stage state
2. extension validation validates the conditional requirements
3. validating the conditional requirements requires setting up generic
signatures
4. setting up generic signatures forces the types conformances and so
ends up in updateLookupTable on the same nominal again, skipping over
the earlier stages that are complete/in progress
5. we expand the conformances that are implied by all the conformances we
know about... But we don't know any, because we haven't finished the
first updateLookupTable.
This breaks the loop at step 2: we instead do the minimal work needed to
know what conformances an extension (might) declare, which is connect
the extension to a type, and then resolve the inherited TypeReprs to
Types.
LLDB creates global typealiases that have archetypes in them, which
violates AST invariants and trips up the AST verifier. Introduce a specific
bit that LLDB can set to indicate that a given typealias is such an alias.
We'll skip AST verification for such typealiases.
As a way to stage in this change without requiring synchronization
across the Swift and LLDB repos, also match typealiases with the names
$.*lldb in the AST verifier and skip verification. Once LLDB is
setting the bit appropriately, we'll remove this hack.
Rather than relying on the NameAliasType we get by default for references
to non-generic typealiases, use BoundNameAliasType consistently to handle
references to typealiases that are formed by the type checker.
Instead of passing the base expression of a member access to `getAccessSemanticsFromContext`, we now just pass a bool flag for whether this is a member access on the implicit 'self' declaration.
Currently we always directly access a member when mutating it in its own didSet/willSet observer (in order to prevent infinite recursion). However we also do this even when accessing the same member on a *different* instance.
This commit changes the behaviour such that only member accesses on the implicit 'self' declaration are accessed directly within that member's own willSet/didSet.
Note that this change has the potential to cause recursion in cases where it didn't previously, for example this will now infinitely recurse:
struct S {
var i = 0 {
didSet {
var s = self
s.i = 5
}
}
}
var s = S()
s.i = 2
I don't know how serious this impact is though.
Resolves SR-419.
- Reuse existing logic to curry the signature type with the 'self' of the context (in addition we no longer use a MetatypeType for the 'self' of a static member as they don't have conflicting signatures with instance members anyway)
- Limit the fix for SR-7251 to Swift 5 mode
- Add tests for generic subscripts
Currently we only give subscripts and var decls custom overload types if they're in generic extensions. However, because we give them no custom overload type in any other case, we don't detect for example a conflict with a previous declaration in the body of the extended type.
This commit changes the overload type logic such that properties and subscripts are always given custom overload types, which is determined by:
- The interface type of the decl (for subscripts only; as variables cannot be overloaded by type)
- The 'self' type of the context, if any
- The generic signature of the context, if any
Additionally, this commit adds a new `swift::conflicting` overload to ensure that different declarations always conflict even if their overload types are different.
Resolves SR-7249, SR-7250 & SR-7251.
Previously (a03c40cb2c) we assumed all Swift enums were non-frozen in
ObjC, a weird choice in retrospect. Now that we actually distinguish
frozen and non-frozen enums in Swift, we can use the
'enum_extensibility' attribute to mark them as open or closed in ObjC.
Note that this only matters for Swift libraries compiled with
-enable-resilience, i.e. those that might get a new implementation at
runtime. Everyone else is now declaring a "closed" enum, matching the
behavior in Swift.
"Formally non-resilient" in this new world means "the enum has a fixed
representation", which implies a fixed layout algorithm. We're not
there yet, but non-exhaustive enums should be able to be fixed-layout
as well by picking a general representation that won't need to grow.
Specifically, that's enums with raw types, and possibly also indirect
enums as well.
(It's likely the '_fixed_layout' /attribute/ on enums will go away,
but the concept of a fixed-layout enum is still useful.)
Warn in Swift 4 mode and error in Swift 5 mode when switching on a
non-frozen enum without providing a default case.
Note that this is a preliminary implementation, in order to test the
rest of the feature.
We have a predicate in ClassDecl, 'inheritsSuperclassInitializers',
that is used in a few places to decide if we need to do lookups into a
superclass to find all relevant initializers. That's useful, but the
actual work being computed in that function is almost identical to the
work done in figuring out whether the class has provided all its
superclass's /required/ initializers, which is part of the type
checker operation 'resolveImplicitConstructors'. Furthermore,
'inheritsSuperclassInitializers' is /already/ calling
'resolveImplicitConstructors' because those implicit constructors
might affect the result.
Simplify this whole mess and prevent further inconsistencies like the
previous commit by just making 'resolveImplicitConstructors' decide
whether superclass convenience initializers are inherited. It does
make that function more complicated, but with the benefit of not
having duplication anymore.
No intended user-visible change, except that this bit is now
serialized instead of being recomputed, which means the module format
changed.
Implements the minimum specified by the SE-proposal.
* Add the CaseIterable protocol with AllCases associatedtype and
allCases requirement
* Automatic synthesis occurs for "simple" enums
- Caveat: Availability attributes suppress synthesis. This can be
lifted in the future
- Caveat: Conformance must be stated on the original type
declaration (just like synthesizing Equatable/Hashable)
- Caveat: Synthesis generates an [T]. A more efficient collection
- possibly even a lazy one - should be put here.
