Use the `%target-swift-5.1-abi-triple` substitution to compile the tests for
deployment to the minimum OS versions required for use of opaque types, instead
of disabling availability checking.
I think the original idea was to elide `Array<$T>` if there is
a binding a resolved generic arguments i.e. `Array<Float>`, but
the check doesn't account for the fact that bindings could be
of different kinds and there are some implicit conversions that
could be missed if we remove the bindings.
For example, given the following constraints:
`Array<$T0> conv $T1`
`$T1 conv Array<(String, Int)>`
`$T0` can be a supertype of `Array<$T0>` and subtype of `Array<(String, Int)>`.
The solver should accept both types as viable bindings because the
`$T0` could be bound to `(key: String, value: Int)` and that would
match `Array<(String, Int)>` conversion.
This is related to 22e0f4a3d6.
Binding inference doesn't mark type variables that appear in
dependent member chains as "adjacent" which means that type
variables that represent generic arguments cannot be attempted
sooner due to incomplete information provided by the inference.
To fix this we'd need to remove `findInferrableTypeVars` and
replace its uses with `Type::getTypeVariables(...)`. This is
a risky change that would require some evaluation because it
could end breaking existing code but it would make sure that
for cases like `Row<$T0> conv $T1.ArrayLiteralElement` `$T0`
always gets associated with `$T1`.
`lookupConformance` request is not cached and constraint solver
performs a lot of them for the same type (i.e. during disjunction
solving), let's try to cache previously performed requests to
see whether additional memory use is worth the performance benefit.
Reverts apple/swift#30006. It caused a regression that we'd like to address before re-landing:
```swift
struct X {
var cgf: CGFloat
}
func test(x: X?) {
let _ = (x?.cgf ?? 0) <= 0.5
}
```
This reverts commit 0a6b444b49.
This reverts commit ed255596a6.
This reverts commit 3e01160a2f.
This reverts commit 96297b7e39.
Resolves: rdar://problem/60185506
Introduce a fix to detect and diagnose situations when omitted
generic arguments couldn't be deduced by the solver based on
the enclosing context.
Example:
```swift
struct S<T> {
}
_ = S() // There is not enough context to deduce `T`
```
Resolves: rdar://problem/51203824
Detect and diagnose a contextual mismatch between expected
collection element type and the one provided (e.g. source
of the assignment or argument to a call) e.g.:
```swift
let _: [Int] = ["hello"]
func foo(_: [Int]) {}
foo(["hello"])
```
Extend existing `RequirementFailure` functionality to support
conditional requirement failures. Such fixes are introduced
only if the parent type requirement has been matched successfully.
Resolves: rdar://problem/47871590
This patch avoids merging type variables inside UnresolvedMemberExpr
and those outside, because they may not always be equivalent in CS.
Resolves: SR-8385.
And provide better semantic background by surrounding 'nil' in ticks when it is referred to as a value
Added missing tests for certain cases involving nil capitalization
This fixes two easy cases where we would go exponential in type
checking tuple literals.
Instead of generating a conversion to a single type variable (which
results in one large constraint system), we generate a conversion ot
the same type that appears in the initializer expression (which for
tuples is a tuple type, which naturally splits the constraint system).
I experimented with trying to generalize this further, but ran into
problems getting it working, so for now this will have to do.
Fixes rdar://problem/20233198.
Also remove mention of the word “contextual” type from the diagnostic
that rewrites array literals into dictionary literals and scale back
the scope of the diagnostic. This method was catching and
mis-diagnosing too many errors that could better be handled by invalid
conversion diagnostics.
Early on in the development of conditional conformances, we put in a bunch
of assertions for code that uses `conformsToProtocol()` but wasn't handling
conditional conformances. Now, `conformsToProtocol()` handles conditional
conformances by default, and these assertions are tripping up code
that would work.
Remove the assertions and add test cases that used to trip up the
assertions (but now work).
For the moment, update the sole caller to not infer Any in cases where
neither argument was Any. This is in part because not all the cases are
handled here and the result of inferring Any will be to miss appropriate
bindings in certain cases. It is also in part because by inferring Any
we may end up deferring diagnostics until later in a function, which may
result in very hard to understand diagnostics for users.
This will be revisted once all the cases are properly handled here.
When we saw lvalue- or inout-types we were not appropriately looking at
the underlying types when performing a join. As a result we would infer
Any in cases where we should have inferred a common supertype.
rdar://problem/31127419
Currently some contextual errors are discovered too late
which leads to diagnostics of unrelated problems like argument
mismatches, these changes attempt to improve the situation
and try to diagnose contextual errors related to calls
before everything else.
Resolves: SR-5045, rdar://problem/32934129
Record the initializer type as soon as we have a solution, before
it is applied, and get the type from the constriant system instead
of from the final type checked expression.
Note that the coerceToMaterializable() was unnecessary, since we
always coerce the value to an rvalue type with coerceToType().
Eventually coerceToMaterializable() should go away.
This is mostly NFC, except using the result of simplifyType() rather
than the type of the final expression changes some diagnostics where it
appears we were previously losing sugar.
Also this accidentally fixes a crasher. Unfortunately the underlying
issue is still there (applying a solution has bugs with opened
existentials "leaking" out) -- this merely masks the problem by
getting the initializer type directly from the constriant system.
When matching inputs of a function type, be sure to
strip off ParenType sugar so that we don't end up
with ParenTypes in associated type witnesses.
This fixes various issues with SE-0110.
Fixes <rdar://problem/32214649>.
* Give Sequence a top-level Element, constrain Iterator to match
* Remove many instances of Iterator.
* Fixed various hard-coded tests
* XFAIL a few tests that need further investigation
* Change assoc type for arrayLiteralConvertible
* Mop up remaining "better expressed as a where clause" warnings
* Fix UnicodeDecoders prototype test
* Fix UIntBuffer
* Fix hard-coded Element identifier in CSDiag
* Fix up more tests
* Account for flatMap changes
We previously penalized bindings to Any, and that resulted in
inappropriately rejecting solutions where we bind a decl that is
explicitly typed Any. That penalty was removed in
170dc8acd7, but that has led to a variety
of source compatibility issues.
So now, we'll reintroduce a penalty for Any-typed things, but instead of
penalizing bindings (which happen both because of explicitly-typed
values in the source, and implicitly due to attempting various types for
a particular type variable), penalize casts, which are always present in
some form in the source.
Thanks go to John for the suggestion.
Fixes
SR-3817 (aka rdar://problem/30311052)
SR-3786 (aka rdar://problem/30268529)
rdar://problem/29907555
This function had a weird, pre-ProtocolConformanceRef interface that
returned true when the type conformed to the protocol, then had a
separate indirect return value for the concrete conformance (if there
is one). Refactor this API, and the similar
TypeChecker::containsProtocol(), to produce an optional
ProtocolConformanceRef, which is far more idiomatic and easier to
use. Push ProtocolConformanceRef into a few more places. Should be NFC
The constraint solver tries not to solve for type variables that
"involve other type variables", which handles the case where we have
seen a constraint that mentions the type variable under consideration
as well as a different type variable, but in a constraint that we
cannot capture in a binding. Solving for such type variables too early
can lead to missed solutions, so we avoid it.
Tweak the logic for this computation to not consider type variables
mentioned within dependent member types (e.g., $T0.Iterator.Element),
because such types do not affect type inference at all, and therefore
shouldn't prevent solving for the type variable in question.
The join operation for optional types is straightforward to define/implement:
join(T?, U) ::= join(T, U)?
join(T, U?) ::= join(T, U)?
join(T?, U?) ::= join(T, U)?
As a special case in the constraint solver, handle the join of a 'nil'
literal with a non-ExpressibleByNilLiteral-conforming concrete type
'T' to produce 'T?'. This allows us, e.g., infer [String?] for the
expressions
["hello", nil]
and
true ? "hello" nil
for example. Fixes rdar://problem/16326914.
The id-as-Any work regressed cases where Swift code could specify
heterogeneous collection literals, e.g.,
var states: [String: Any] = [
"California": [
"population": 37_000_000,
"cities": ["Los Angeles", "San Diego", "San Jose"],
],
"Oregon": [
"population": 4_000_000,
"cities": ["Portland", "Salem", "Eugene"],
]
]
Prior to this, the code worked (when Foundation was imported) because
we'd end up with literals of type [NSObject : AnyObject].
The new defaulting rule says that the element type of an array literal
and the key/value types of a dictionary literal can be defaulted if no
stronger type can be inferred. The default type is:
Any, for the element type of an array literal or the value type of a
dictionary literal, or
AnyHashable, for the key type of a dictionary literal.
The latter is intended to compose with implicit conversions to
AnyHashable, so the most-general inferred dictionary type is
[AnyHashable : Any] and will work for any plausible dictionary
literal.
To prevent this inference from diluting types too greatly, we don't
allow this inference in "top-level" expressions, e.g.,
let d = ["a" : 1, "b" : "two"]
will produce an error because it's a heterogeneous dictionary literal
at the top level. One should annotate this with, e.g.,
let d = ["a" : 1, "b" : "two"] as [String : Any]
However, we do permit heterogeneous collections in nested positions,
to support cases like the original motivating example.
Fixes rdar://problem/27661580.
This flips the switch to have @noescape be the default semantics for
function types in argument positions, for everything except property
setters. Property setters are naturally escaping, so they keep their
escaping-by-default behavior.
Adds contentual printing, and updates the test cases.
There is some further (non-source-breaking) work to be done for
SE-0103:
- We need the withoutActuallyEscaping function
- Improve diagnostics and QoI to at least @noescape's standards
- Deprecate / drop @noescape, right now we allow it
- Update internal code completion printing to be contextual
- Add more tests to explore tricky corner cases
- Small regressions in fixits in attr/attr_availability.swift
We were crashing attempting to diagnose the case where we cannot assign
an array literal to a type conforming to _ArrayProtocol because we don't
know the element types of the conforming type.
We still don't give a great diagnostic for this, so I've
opened (rdar://problem/27594154) to track improving it.
Resolves rdar://problem/25563498.
What I've implemented here deviates from the current proposal text
in the following ways:
- I had to introduce a FunctionArrowPrecedence to capture the parsing
of -> in expression contexts.
- I found it convenient to continue to model the assignment property
explicitly.
- The comparison and casting operators have historically been
non-associative; I have chosen to preserve that, since I don't
think this proposal intended to change it.
- This uses the precedence group names and higherThan/lowerThan
as agreed in discussion.
change includes both the necessary protocol updates and the deprecation
warnings
suitable for migration. A future patch will remove the renamings and
make this
a hard error.
