Previously solution application only supported references to
key path dynamic member lookup as components but it should support both kinds.
Resolves: rdar://problem/60225883
Resolves: [SR-12313](https://bugs.swift.org/browse/SR-12313)
Introduce `SK_Hole` which is used to count a number of "holes" in
a given solution. It is used to distinguish solutions with fewer holes.
Also it makes it possible to check whether a solution has holes but
no fixes, which is an issue and such solution shouldn't be applied
to AST.
If solution score indicates that there should be a fix but
none where recorded fail solution application and produce
a fallback diagnostic to pin-point a problem.
Resolves: rdar://problem/60663007
Make sure that we're resolving types and patterns using the
PatternBindingDecl context, both for the type resolver context and the
contextual pattern used for pattern resolution.
Fixes a regression with implicitly-unwrapped options reported as
SR-11998 / rdar://problem/58455441.
When a method is called with fewer than two parameter lists,
transform it into a fully-applied call by wrapping it in a
closure.
Eg,
Foo.bar => { self in { args... self.bar(args...) } }
foo.bar => { self in { args... self.bar(args...) } }(self)
super.bar => { args... in super.bar(args...) }
With this change, SILGen only ever sees fully-applied calls,
which will allow ripping out some code.
This new way of doing curry thunks fixes a long-standing bug
where unbound references to protocol methods did not work.
This is because such a reference must open the existential
*inside* the closure, after 'self' has been applied, whereas
the old SILGen implementation of curry thunks really wanted
the type of the method reference to match the opened type of
the method.
A follow-up cleanup will remove the SILGen curry thunk
implementation.
Fixes rdar://21289579 and https://bugs.swift.org/browse/SR-75.
Instead of always applying solution back to constraint system
before diagnostics, let's pass solution directly to `ConstaintFix::diagnose`
method to be used by `FailureDiagnostic` which paves a way for
stateless diagnostics.
Previously we were using `getPlainType` to match
the parameter type against the key path's base
type. This gave us the external parameter type,
which would be the element type for a variadic
parameter. However the code we generate expects
the internal parameter type, which is provided by
`getParameterType`.
Resolves rdar://problem/59445486.
The "opened type" of a subscript reference has all references to Self
immediately substituted out, which destroys the link between Self and
the opened existential type we form for the "fully opened type". This
means, in general, we cannot use this type when rewriting subscript
applies, or we'll miss closing opened existentials.
Use the "fully opened type" everywhere except the AnyObject subscript
path. Then, add an assertion that AnyObject subscripts never involve
opened archetypes that we would have to close.
Resolves SR-11748, rdar://57092093
Implement support for switch statements within function builders. Cases can
perform arbitrary pattern matches, e.g.,
tuplify(true) { c in
"testSwitchCombined"
switch e {
case .a:
"a"
case .b(let i, _?), .b(let i, nil):
i + 17
}
}
subject to the normal rules of switch statements. Cases within function
builders cannot, however, include “fallthrough” statements, because those
(like “break” and “continue”) are control flow.
The translation of performed for `switch` statements is similar to that of
`if` statements, using `buildEither(first:)` and `buildEither(second:)` on
the function builder type.
This is the bulk of switch support, tracked by rdar://problem/50426203.
Handle StmtCondition as part of SolutionApplicationTarget, so we can
generate constraints from it and rewrite directly as part of a solution,
rather than open-coding the operation in the function builder transform.
When extracting substitutions during type lowering, we can't discard protocol constraints
in positions where the substitution is for a nominal type's generic arguments, since associated
types on that protocol may affect the nominal type's ABI.
If it's possible to build an Objective-C key path for key path
expression make sure that its implicitly generated string literal
expression has a `String` type.
Resolves: rdar://problem/57356196
When applying a function builder to a closure to produce the final,
type-checked closure, use the new rewriteTarget() so it’s performed on
a per-target basis. Use this to eliminate some duplicating in the handling
of return types.
Pull out the core operation of rewriting a given SolutionApplicationTarget
into into a method on the ExprWalker that does the overall rewrite, so it
can be called multiple times within application.
Rather than having separate dense maps for the type mappings of each
node type (expression, type location, variable declaration, pattern) that
a TypedNode can be, have a single such map. Sometimes we end up
setting a particular node's type more than once, so cope with that
by restoring the prior type.
Move the remaining logic of typeCheckBinding, which consists of applying
the solution to the pattern, down into the normal solution application
path. typeCheckBinding() is now a thin shell over the normal
typeCheckExpression() convenience function.
Sink the solution-application code from typeCheckBinding’s
ExprTypeCheckListener subclass into normal solution application, allowing
us to eliminate this subclass entirely. Down to one…
Sink the constraint generation for initialization patterns, including all
of the logic for property wrappers, from the high-level entry point
`typeCheckBinding` down into the lower-level constraint generation for
solution application targets.
