When there is a conversion from e.g. `(A) -> Void` to `(B) -> Void`
matching between `A` and `B` is going to have a special locator which
doesn't end in `TupleElement`, so `repairFailures` has to account
for that and fix it just like regular argument mismatch.
Resolves: rdar://problem/59066040
Since `simplifyRestrictedConstraintImpl` has both parent types and
does nested type matching it's a good place to diagnose top-level
contextual problems like mismatches in underlying types of optionals.
If parameter type is optional let's ignore that since argument could
be either optional itself or be injected into optional implicitly.
```swift
func foo(_: ((Int, Int) -> Void)!) {}
foo { _ in } // Missing second closure parameter
```
Originally type mismatches associated with conversions between
function types were only covered for coercions and assignments
but fix coverage grew since then and now it makes sense
to remove special case and let `repairFailures` take care of it.
When SE-110 was being implemented, we accidentally began to accept
closure parameter declarations that had no associated parameter names,
e.g.
foo { ([Int]) in /**/ }
This syntax has never been sanctioned by any version of Swift and should
be banned. However, the change was made long enough ago and there are
enough clients relying on this, that we cannot accept the source break
at the moment. For now, add a bit to ParamDecl that marks a parameter
as destructured, and back out setting the invalid bit on the type repr
for these kinds of declarations.
To prevent further spread of this syntax, stub in a warning that offers
to insert an anonymous parameter.
Resolves part of rdar://56673657 and improves QoI for errors like
rdar://56911630
Use the isInvalid() bit on the TypeRepr to signal that a closure
parameter is potentially a tuple destructure. This has two benefits
1) Parse is no longer using the isInvalid() bit on Decl
2) Invalidating the type repr itself means that we no longer spuriously
diagnose variable patterns in destructures as missing types.
In situations like this:
```swift
func foo(x: (Int, Int) {}
foo(x: 0, 0)
```
Left paren to form a missing tuple should be placed after
the label because belongs to the parameter and not the tuple.
Currently single parameter tuple splat fix/diagnostic supports only
cases where parameter is a concrete tuple type, let's enhance that to
support generic parameters as well e.g.:
```swift
func foo<T>(_: T) {}
foo(0, 1, 2) // `T` expects arguments to form a tuple e.g. `foo((0, 1, 2))`
```
If the only difference between two functions is `throws` and it
is not a subtype relationship, let's repair the problem by dropping
`throws` attribute and letting solver continue to search for
a solution, which would later be diagnosed.
Diagnose situation when a single "tuple" parameter is given N arguments e.g.
```swift
func foo<T>(_ x: (T, Bool)) {}
foo(1, false) // foo exptects a single argument of tuple type `(1, false)`
```
Escapingness is a property of the type of a value, not a property of a function
parameter. Having it as a separate parameter flag just meant one more piece of
state that could get out of sync and cause weird problems.
Instead, always look at the noescape bit in a function type as the canonical
source of truth.
This does mean that '@escaping' is now printed in a few diagnostics where it was
not printed before; we can investigate these as separate issues, but it is
correct to print it there because the function types in question are, in fact,
escaping.
Fixes <https://bugs.swift.org/browse/SR-10256>, <rdar://problem/49522774>.
12a65fffee restricted tuple splat
to a single tuple or type variable parameter, but it has to
support dependent member types as well because they could be
resolved to `Void` (or empty tuple).
Resolves: rdar://problem/48443263
Back when SE-0110 was implemented we decided that passing a function value
taking multiple parameters would be allowed where a function value taking
a single tuple argument was expected.
Due to quirks in the old function type representation, the "splat" in the
other direction sometimes worked too. When we redid the function type
representation we added a simulation of the old quirk for -swift-version 4
mode.
However this simulation was itself problematic because it only worked when
the function value being passed was a non-overloaded declaration reference.
Slightly broaden the hack to the overloaded case, to prevent user
confusion when adding or removing overloads.
This makes diagnostics more verbose and accurate, because
it's possible to distinguish how many parameters there are
based on the message itself.
Also there are multiple diagnostic messages in a format of
`<descriptive-kind> <decl-name> ...` that get printed as
e.g. `subscript 'subscript'` if empty labels are omitted.
This patch adds warning for redundant access-level modifiers
used in an extension. It also refines the diagnostics of
access_control_ext_member_more issues, in case the fixit
could suggest redundant modifiers.
Resolves: SR-8453.
From the perspective of the compiler implementation, they're elements. But users will think of these as cases—and many diagnostics already refer to these as enum cases.
Move the existing test into Compatibility/tuple_arguments_4.swift.
Move the Swift 3 test, Compatibility/tuple_arguments.swift, into
Compatibility/tuple_arguments_4.swift.
Add a couple new tests to each file to capture what we do in each
mode.
Overall this doesn't seem like the most satisfying approach for
covering compatibility testing in our standard commit testing, but
it's all we've got at the moment.
Allow functions with type `(()) -> T` to be passed in places where we
expect `() -> T`, but only for -swift-version 4 (for -swift-version 3
this already works due to other horrible things in CSSimplify.cpp).
We need to look at how we can help migrate these cases to
-swift-version 5, but in the meantime, but that is something we can
consider separately.
We inadvertantly allowed a function conversion for Swift 4 that we did
not intend to allow.
This commit adds an extremely narrow fix to continue to allow this for
-swift-verson 4 only.
Fixes rdar://problem/36875195 / https://bugs.swift.org/browse/SR-6837
Stop creating ImplicitlyUnwrappedOptional<T> so that we can remove it
from the type system.
Enable the code that generates disjunctions for Optional<T> and
rewrites expressions based on the original declared type being 'T!'.
Most of the changes supporting this were previously merged to master,
but some things were difficult to merge to master without actually
removing IUOs from the type system:
- Dynamic member lookup and dynamic subscripting
- Changes to ensure the bridging peephole still works
Past commits have attempted to retain as much fidelity with how we
were printing things as possible. There are some cases where we still
are not printing things the same way:
- In diagnostics we will print '?' rather than '!'
- Some SourceKit and Code Completion output where we print a Type
rather than Decl.
Things like module printing via swift-ide-test attempt to print '!'
any place that we now have Optional types that were declared as IUOs.
There are some diagnostics regressions related to the fact that we can
no longer "look through" IUOs. For the same reason some output and
functionality changes in Code Completion. I have an idea of how we can
restore these, and have opened a bug to investigate doing so.
There are some small source compatibility breaks that result from
this change:
- Results of dynamic lookup that are themselves declared IUO can in
rare circumstances be inferred differently. This shows up in
test/ClangImporter/objc_parse.swift, where we have
var optStr = obj.nsstringProperty
Rather than inferring optStr to be 'String!?', we now infer this to
be 'String??', which is in line with the expectations of SE-0054.
The fact that we were only inferring the outermost IUO to be an
Optional in Swift 4 was a result of the incomplete implementation of
SE-0054 as opposed to a particular design. This should rarely cause
problems since in the common-case of actually using the property rather
than just assigning it to a value with inferred type, we will behave
the same way.
- Overloading functions with inout parameters strictly by a difference
in optionality (i.e. Optional<T> vs. ImplicitlyUnwrappedOptional<T>)
will result in an error rather than the diagnostic that was added
in Swift 4.1.
- Any place where '!' was being used where it wasn't supposed to be
allowed by SE-0054 will now treat the '!' as if it were '?'.
Swift 4.1 generates warnings for these saying that putting '!'
in that location is deprecated. These locations include for example
typealiases or any place where '!' is nested in another type like
`Int!?` or `[Int!]`.
This commit effectively means ImplicitlyUnwrappedOptional<T> is no
longer part of the type system, although I haven't actually removed
all of the code dealing with it yet.
ImplicitlyUnwrappedOptional<T> is is dead, long live implicitly
unwrapped Optional<T>!
Resolves rdar://problem/33272674.
Fix problem related to Swift 3 mode (with assertions),
since Swift 3 mode allows passing arguments with extra parens
to parameters which don't expect them, it should be supported
by "deep equality" types e.g. Optional<T>:
```swift
func foo(_: (() -> Void)?) {}
func bar() -> ((()) -> Void)? { return nil }
foo(bar) // This expression should compile in Swift 3 mode
```
Resolves: rdar://problem/35198459
There was an oversight in the exception that was added to SE-0110 to
maintain compatibility for closure arguments. We were not allowing
optional injection to happen for the closure being passed in, so things
like:
func test(_ fn: ((Int, Int))->()) {}
test { x, y in }
worked, but
func test(_ fn: (((Int, Int))->())?) {}
test { x, y in }
did not.
Fixes SR-5433 (rdar://problem/33239714).
