[Diagnostics] Nullify contextual type if it's generic with type variables #6806
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/cc @rudkx @slavapestov |
| convertType = replaceTypeParametersWithUnresolved(convertType); | ||
| convertType = replaceTypeVariablesWithUnresolved(convertType); | ||
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| bool shouldNullify = false; |
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This is just objectType->is<ArchetypeType>() || objectType->hasUnresolvedType()
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I moved both calls down after decision to nullify because we need original types to figure what was what to decide nullification.
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And just to clarify a bit, objectType->hasUnresolvedType() is not appropriate in this case standalone, because if it's in a function for example or inout type we still want to preserve it's skeleton because that helps to diagnose inout argument issues. Complete nullification is only appropriate for generic types with unresolved types or standalone archetypes because that's going to give sub-expression solver a chance to try and compute type as it sees and higher level code is going to check it, which avoids error messages like cannot convert (_) -> _ to (Int) -> Void or similar.
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Ok, maybe then just factoring this in its own method would be nice. Also please add a comment with the above explanation :-)
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Sure, will do later today, thanks! :)
…bles It's undesirable to have generic type which contains type variables as contextual conversion type while diagnosing sub-expressions, it's going to result in attempt to convert generic arguments to unresolved type which produces worse diagnostics than no contextual type at all. Resolves: SR-3525.
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@slavapestov I've added |
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@swift-ci Please smoke test |
It's undesirable to have generic type which contains type variables
as contextual conversion type while diagnosing sub-expressions, it's
going to result in attempt to convert generic arguments to unresolved
type which produces worse diagnostics than no contextual type at all.
Resolves SR-3525.