[ConstraintSystem] Detect and diagnose missing generic arguments #25149
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…locator points to one
Emit separate notes for generic parameters found in operator, initializer and function declarations. As well as clarify types of `declared in type` note.
… member to `Any` As part of the `DefineBasedOnUse` fix introduced in places where there is a reference to non-existent member, let's also add constraints which allow to default any generic parameters found in base type to `Any`.
Introduce a fix to detect and diagnose situations when omitted
generic arguments couldn't be deduced by the solver based on
the enclosing context.
Example:
```swift
struct S<T> {
}
_ = S() // There is not enough context to deduce `T`
```
Resolves: rdar://problem/51203824
…uments with new diagnostic
slavapestov
approved these changes
May 30, 2019
| @@ -102,7 +102,7 @@ func longArray() { | |||
| var _=["1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1", "1"] | |||
| } | |||
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| [1,2].map // expected-error {{expression type '((Int) throws -> _) throws -> [_]' is ambiguous without more context}} | |||
| [1,2].map // expected-error {{generic parameter 'T' could not be inferred}} | |||
| @@ -79,7 +79,8 @@ func badDiagnostic2() { | |||
| func takesAny(_ a: Any) {} | |||
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| func badDiagnostic3() { | |||
| takesAny(Deli.self) // expected-error {{argument type 'Deli<_>.Type' does not conform to expected type 'Any'}} | |||
| // expected-error@-1 {{generic parameter 'A' could not be inferred}} | ||
| _ = Claws.Fangs<NotADog>() | ||
| // expected-error@-1 {{generic parameter 'A' could not be inferred}} | ||
| // expected-error@-2 {{referencing initializer 'init()' on 'Claws.Fangs' requires that 'NotADog' conform to 'ExpressibleByDogLiteral'}} |
| let _ : D = D<Int, Int, Float>(a: 1, b: 2) | ||
| // expected-error@-1 {{generic parameter 'T3' could not be inferred}} |
slavapestov
reviewed
May 30, 2019
slavapestov
reviewed
May 30, 2019
slavapestov
reviewed
May 30, 2019
xedin
commented
May 30, 2019
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| _ = Pair< // expected-error {{generic parameter 'Foo' could not be inferred}} | ||
| _ = Pair< | ||
| FullyGeneric, |
There was a problem hiding this comment.
@slavapestov I think the biggest improvement here is actually related to couple of examples down here, which we now diagnostic relative to TypeRepr and suggest all of the missing signatures.
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This is great! Would it be possible to show the declaration name in the diagnostic? For some of these cases, I think it'd be easier to understand if the diagnostic could point at the declaration the generic argument comes from, e.g.: since in some cases there may be multiple generic declarations involved in an expression. |
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@jckarter Yes, absolutely, also I'll also cover more cases in the note, it currently only covers functions and initializes. |
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@swift-ci please test |
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@swift-ci please test source compatibility |
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Build failed |
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Build failed |
This was referenced May 31, 2019
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Introduce a fix to detect and diagnose situations when omitted
generic arguments couldn't be deduced by the solver based on
the enclosing context.
Example:
Resolves: rdar://problem/51203824