When realizing a type like Foo<A>.Bar, we have to account for the
possibility that Bar is defined in a constrained extension of Foo,
and has generic requirements beyond those that Foo itself places
on 'A'.
Previously we only handled this for types referenced from the
constraint system as part of openUnboundGenericType(), so we were
allowing invalid types through in type context.
Add the right checking to applyGenericArguments() to close the
hole. Note that the old code path still exists in the constraint
solver; it is used for member accesses on metatype bases only.
Fixes <https://bugs.swift.org/browse/SR-10466>.
An awful pattern we use throughout the compiler is to save and restore global flags just for little things. In this case, it was just to turn on some extra options in AST printing for type variables. The kicker is that the ASTDumper doesn't even respect this flag. Add this as a PrintOption and remove the offending save-and-restores.
This doesn't quite get them all: we appear to have productized this pattern in the REPL.
solve() is a bit too overloaded, so rename the version that does the
core "evaluate all of the steps to produce a set of solutions"
functionality to solveImpl().
automatically.
This commit also renames `ConstraintSystem::recordHole/isHole` to
`recordPotentialHole` and `isPotentialHole` to make it clear that
we don't know for sure whether a type variable is a hole until it's
bound to unresolved.
all cases of missing generic parameters.
In `ComponentStep::take` when there are no bindings or disjunctions, use hole
propagation to default remaining free type variables that aren't for generic
parameters and continue solving. Rather than using a defaultable constraint for
holes, assign a fixed type directly when we have no bindings to try.
Diagnose ephemeral conversions that are passed to @_nonEphemeral
parameters. Currently, this defaults to a warning with a frontend flag
to upgrade to an error. Hopefully this will become an error by default
in a future language version.
Patch up all the places that are making a syntactic judgement about the
isInvalid() bit in a ValueDecl. They may continue to use that query,
but most guard themselves on whether the interface type has been set.
ProtocolConformanceRef already has an invalid state. Drop all of the
uses of Optional<ProtocolConformanceRef> and just use
ProtocolConformanceRef::forInvalid() to represent it. Mechanically
translate all of the callers and callsites to use this new
representation.
"Condition" path element is used to represent a condition expression
associated with `if` expression or ternary operator `? :`.
Locator has been changed in the way that it's now anchored from `if`
itself which simplifies down to condition expression it needed.
Extend #27668 by declining to validate the type of variables
bound by a pattern binding initializer when computing an effective
overload type while rooted at that initializer.
