Follow the feature flag convention for capitalization and be
consistent with the related NoncopyableGenerics feature.
This is a new feature that no wild Swift code has used it yet:
commit e99ce1cc5d
Author: Kavon Farvardin <kfarvardin@apple.com>
Date: Tue Dec 5 23:25:09 2023
[NCGenerics] add `~Escapable`
Basic implementation of `~Escapable` in the type system.
A reference to a subscript (whether instance or static) produces a
function type, which is then applied as part of an application
constraint. Make sure that we encode whether the subscript can throw,
and the thrown error type if present, in that function type. This lets
us correctly treat subscripts as a potential throw sites.
Start classifying all potential throw sites within a constraint
system and associate them with the nearest enclosing catch node. Then,
determine the thrown error type for a given catch node by taking the
union of the thrown errors at each potential throw site. Use this to
compute the error type thrown from the body of a `do..catch` block
within a closure.
This behavior is limited to the upcoming feature `FullTypedThrows`.
Previously, 'IntroducerLoc' and 'ThePattern' were only used for pattern
binidng cases. Create a new 'ConditionalPatternBindingInfo' type to
cover such cases, and make 'StmtConditionElement' a pure 'PointerUnion'
type.
This makes it clear which fields are used in which condition kind. Also,
we can expect overall size reduction of StmtCondition when the
majority of the conditions are simple boolean expressions.
Correctly determining the DeclContext needed for an
ExplicitCaughtTypeRequest is tricky for a number of callers, and
mistakes here can easily lead to redundant computation of the caught
type, redundant diagnostics, etc.
Instead, put a `DeclContext` into `DoCatchStmt`, because that's the
only catch node that needs a `DeclContext` but does not have one.
When a file defining an API is included in two modules, clients calling
that API may get an error about the ambiguity on the duplicated API.
That error is not very helpful when it takes into account the
swiftsourceinfo data and points to the source file instead of the
module. In such a case the notes point twice to the same file and line
of code.
Improve this diagnostic by appending the module name to the notes when a
candidate is found outside of the module.
rdar://116255141
This commit diagnoses cdecl implementations with no matching imported declaration, and also runs them through the ObjCImplementationChecker. Actually testing that the ObjCImplementationChecker diagnoses various failure conditions correctly will be added in a subsequent commit.
Accessors are conceptually nested within their property or subscript
declarations, so member-attribute macros should only apply to the
property or subscript declarations. This eliminates what appears to be
redundant macro expansion.
Fixes rdar://118956800.
The number of errors in a function scope can scale exponentially,
making it hard to root cause and resolve unless we group them into
a single error. Grouping the error diagnostics will considerably
improve the concurrency user experience.
There are some situations where the solver is able to find a valid
solution only during `salvage` (mostly but not limited to unavailable
declarations), which means that we need to keep running `salvage`
even if the diagnostics are suppressed until the underlying issues
in the normal solving mode are fixed.
One of the issues:
```swift
extension Unmanaged {
@inline(__always)
internal static func passRetained(_ instance: __owned Instance?) -> Self? {
guard let instance = instance else { return nil }
return .passRetained(instance)
}
}
```
`.passRetained(instance)` is ambiguous during normal solving but
is able to find a solution during `salvage` because it attemtps
more type bindings.
Resolves: rdar://119001449
Teach the constraint system to use the same primitives as elsewhere to
determine the type context for a `throw` statement and the caught
error type within a `do..catch` statement. This makes
explicitly-specified `throws` work on `do..catch` that occurs in
closures.
Cleans up some redundant computations for caught error types.
