Presently subtype constraint is considered a candidate for contraction
via `shouldContractEdge` when left-hand side of the subtype constraint
is an inout type with type variable inside. Although it's intended to
be used only in combination with BindParam constraint assigned to the
same variable, that is actually never checked and contraction of subtype
constraint like that is invalid.
Resolves: rdar://problem/34333874
We've found in practice that multiple different types of expressions
are still going to benefit from shrinking continuing even when it
couldn't simplify up to 10 sub-expressions.
We allowed them for generic parameter inheritance clauses but
not anywhere else. While arguably this has stylistic benefits,
the restriction was not enforced consistently and was mostly a
result of implementation limitations.
Lift the restriction and fix things up where needed to make them
work. This brings us closer to allowing protocols to constrain
the 'Self' type to a subclass of a class by listing the class in
the protocol's inheritance clause, which was a feature from SE-0156,
but this doesn't quite work.
Fixes <https://bugs.swift.org/browse/SR-4678> and
<rdar://problem/31785092>.
Also tweak some of the test iteration bounds to ensure we have data
that better fits the models.
Ideally our counter would be a bit better so that those kinds of
tweaks wouldn't be necessary.
This was fixed by 897effe, which I had originally thought would be a
no-functionality-change commit because it just made things lazier.
Turns out requirement signature deserialization can result in
circularity with sufficiently cross-referential conformances.
This isn't exactly a reduced test case because it still depends on
subclassing NSObject, which probably means there are hidden
dependencies on conforming to standard library protocols. But it's
better than nothing.
https://bugs.swift.org/browse/SR-5191
* Unify the capitalization across all user-visible error messages (fatal errors, assertion failures, precondition failures) produced by the runtime, standard library and the compiler.
* Update some more tests to the new expectations.
This failed once locally because it was relatively close to 1s for type
checking time, so make it a bit more complex so that it is almost
certain to fail with the current compiler compiled with
release/no-asserts.
Move disjunction selection logic one level up from the `solveSimplified`
which allows to simplify its logic and avoid collecting disjunctions
multiple times for each solver step.
Sort constraint components/buckets based on how many disjunctions
they have, that helps to prune some of the branches with incorrect
solutions early which limits overall depth of the search.
Resolves: SR-4714
