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.
This is because we already emit a diagostic to tell the user that the property's type does not match the wrappedValue type, so this diagnostic can be a bit confusing especially because the initializer is synthesized
This commit changes the behaviour of the error for
passing a temporary pointer conversion to an
@_nonEphemeral parameter such that it doesn't
affect overload resolution. This is done by recording
the fix with an impact of zero, meaning that we don't
touch the solution's score.
In addition, this change means we no longer need
to perform the ranking hack where we favour
array-to-pointer, as the disjunction short-circuiting
will continue to happen even with the fix recorded.
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.
If the last parameter is defaulted, there might be
an attempt to use a trailing closure with previous
parameter that accepts a function type e.g.
```swift
func foo(_: () -> Int, _ x: Int = 0) {}
foo { 42 }
```
Resolves: rdar://problem/55102498
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.
Resolve a cycle caused by overload resolution considering recursive
static candidates where before it would silently reject them. In
a world before the InterfaceTypeRequest, the overload resolution
machinery would attempt to validate the declaration and would recieve
a bad answer. This caused circular candidates to be ignored as a side
effect. This behavior was partially restored by the fixes in #27725 and #27668
but that isn't enough for recursive static variables. Even if it were,
the constraint fix kind doesn't make sense.
Luckily, the right answer is to just reject recursive static VarDecl
candidates entirely.
Addresses rdar://56410015
Key path components can reference an invalid or missing member
just like regular expressions, so we need to account for that
while trying to simplify key path constraint.
It's possible to find a suitable overload choice for
key path application through keypath dynamic member
lookup and assertion inside `addKeyPathApplicationRootConstraint`
should account for that.
Resolves: rdar://problem/56350060
If there are more arguments than parameters, let's fix this by
ignoring (if possible) or removing extraneous arguments. Ignored
arguments could default to `Any` if they don't get any other
contextual type.
