We used to get this contextualization "for free" because closures that
had function builders applied to them would get translated into
single-expression closures. Now, we need to check for this explicitly.
The type checking of the for-each loop is split between the constraint
solver (which does most of the work) and the statement checker (which
updates the for-each loop AST). Move more of the work into the constraint
solver proper, so that the AST updates can happen in one place, making use
of the solution produced by the solver. This allows a few things, some of
which are short-term gains and others that are more future-facing:
* `TypeChecker::convertToType` has been removed, because we can now either
use the more general `typeCheckExpression` entry point or perform the
appropriate operation within the constraint system.
* Solving the constraint system ensures that everything related to the
for-each loop full checks out
* Additional refactoring will make it easier for the for-each loop to be
checked as part of a larger constraint system, e.g., for processing entire
closures or function bodies (that’s the futurist bit).
* WIP implementation
* Cleanup implementation
* Install backedge rather than storing array reference
* Add diagnostics
* Add missing parameter to ResultFinderForTypeContext constructor
* Fix tests for correct fix-it language
* Change to solution without backedge, change lookup behavior
* Improve diagnostics for weak captures and captures under different names
* Remove ghosts of implementations past
* Address review comments
* Reorder member variable initialization
* Fix typos
* Exclude value types from explicit self requirements
* Add tests
* Add implementation for AST lookup
* Add tests
* Begin addressing review comments
* Re-enable AST scope lookup
* Add fixme
* Pull fix-its into a separate function
* Remove capturedSelfContext tracking from type property initializers
* Add const specifiers to arguments
* Address review comments
* Fix string literals
* Refactor implicit self diagnostics
* Add comment
* Remove trailing whitespace
* Add tests for capture list across multiple lines
* Add additional test
* Fix typo
* Remove use of ?: to fix linux build
* Remove second use of ?:
* Rework logic for finding nested self contexts
Replaces `ComponentIdentTypeRepr::getIdentifier()` and `getIdLoc()` with `getNameRef()` and `getNameLoc()`, which use `DeclName` and `DeclNameRef` respectively.
This change adds UnresolvedDotExpr::createImplicit() and UnresolvedDeclRefExpr::createImplicit() helpers. These calls simplify several tedious bits of code synthesis that would otherwise become even more tedious with DeclNameRef in the picture.
This commit changes how we represent caller-side
default arguments within the AST. Instead of
directly inserting them into the call-site, use
a DefaultArgumentExpr to refer to them indirectly.
The main goal of this change is to make it such
that the expression type-checker no longer cares
about the difference between caller-side and
callee-side default arguments. In particular, it
no longer cares about whether a caller-side
default argument is well-formed when type-checking
an apply. This is important because any
conversions introduced by the default argument
shouldn't affect the score of the resulting
solution.
Instead, caller-side defaults are now lazily
type-checked when we want to emit them in SILGen.
This is done through introducing a request, and
adjusting the logic in SILGen to be more lenient
with ErrorExprs. Caller-side defaults in primary
files are still also currently checked as a part
of the declaration by `checkDefaultArguments`.
Resolves SR-11085.
Resolves rdar://problem/56144412.
By convention, most structs and classes in the Swift compiler include a `dump()` method which prints debugging information. This method is meant to be called only from the debugger, but this means they’re often unused and may be eliminated from optimized binaries. On the other hand, some parts of the compiler call `dump()` methods directly despite them being intended as a pure debugging aid. clang supports attributes which can be used to avoid these problems, but they’re used very inconsistently across the compiler.
This commit adds `SWIFT_DEBUG_DUMP` and `SWIFT_DEBUG_DUMPER(<name>(<params>))` macros to declare `dump()` methods with the appropriate set of attributes and adopts this macro throughout the frontend. It does not pervasively adopt this macro in SILGen, SILOptimizer, or IRGen; these components use `dump()` methods in a different way where they’re frequently called from debugging code. Nor does it adopt it in runtime components like swiftRuntime and swiftReflection, because I’m a bit worried about size.
Despite the large number of files and lines affected, this change is NFC.
Introduce the notion of "one-way" binding constraints of the form
$T0 one-way bind to $T1
which treats the type variables $T0 and $T1 as independent up until
the point where $T1 simplifies down to a concrete type, at which point
$T0 will be bound to that concrete type. $T0 won't be bound in any
other way, so type information ends up being propagated right-to-left,
only. This allows a constraint system to be broken up in more
components that are solved independently. Specifically, the connected
components algorithm now proceeds as follows:
1. Compute connected components, excluding one-way constraints from
consideration.
2. Compute a directed graph amongst the components using only the
one-way constraints, where an edge A -> B indicates that the type
variables in component A need to be solved before those in component
B.
3. Using the directed graph, compute the set of components that need
to be solved before a given component.
To utilize this, implement a new kind of solver step that handles the
propagation of partial solutions across one-way constraints. This
introduces a new kind of "split" within a connected component, where
we collect each combination of partial solutions for the input
components and (separately) try to solve the constraints in this
component. Any correct solution from any of these attempts will then
be recorded as a (partial) solution for this component.
For example, consider:
let _: Int8 = b ? Builtin.one_way(int8Or16(17)) :
Builtin.one_way(int8Or16(42\
))
where int8Or16 is overloaded with types `(Int8) -> Int8` and
`(Int16) -> Int16`. There are two one-way components (`int8Or16(17)`)
and (`int8Or16(42)`), each of which can produce a value of type `Int8`
or `Int16`. Those two components will be solved independently, and the
partial solutions for each will be fed into the component that
evaluates the ternary operator. There are four ways to attempt that
evaluation:
```
[Int8, Int8]
[Int8, Int16]
[Int16, Int8]
[Int16, Int16]
To test this, introduce a new expression builtin `Builtin.one_way(x)` that
introduces a one-way expression constraint binding the result of the
expression 'x'. The builtin is meant to be used for testing purposes,
and the one-way constraint expression itself can be synthesized by the
type checker to introduce one-way constraints later on.
Of these two, there are only two (partial) solutions that can work at
all, because the types in the ternary operator need a common
supertype:
[Int8, Int8]
[Int16, Int16]
Therefore, these are the partial solutions that will be considered the
results of the component containing the ternary expression. Note that
only one of them meets the final constraint (convertibility to
`Int8`), so the expression is well-formed.
Part of rdar://problem/50150793.
Issuing multiple getStartLoc() from sub-expression can exponentially grow the stack trace.
When the expression under analysis is complex enough, this could be a user-noticeable hang.
This patch fixes UnresolvedDotExpr::getStartLoc() by 'refactoring' the result of SubExpr->getStartLoc()
to a local variable.
rdar://52982457
* Diagnose missing expr in non-void single-expr func. [52025782]
After SE-0255, compiling
```
func foo() -> Int {
return
}
```
would result in a diagnostic without source location:
```
<unknown>:0: error: cannot convert return expression of type '()' to
```
Now, it results in
```
filename.swift:8:5: error: non-void function should return a value
return
^
```
as it did prior to SE-0255.
To achieve that, during type checking for statements, when the
StmtChecker visits return statements, check whether we are within a
non-void-returning, single-expression function and that that single
expression is an implicit empty tuple. (An empty implicit tuple is
added as the result of a resultless return statement that appears as the
only element in a single-expression function.)
To facilitate that, `hasSingleExpressionBody` and
`getSingleExpressionBody` was added to `AnyFunctionRef` and added
`getSingleExpressionBody` to `AbstractClosureExpr` (which already had
`hasSingleExpressionBody`).
rdar://problem/52025782
This change permits UnresolvedDotExpr to have both a name and a base that are implicit, but a valid DotLoc, and to treat that DotLoc as the node’s location. It then changes the generation of string interpolation code so that `$stringInterpolation.appendInterpolation` references have a DotLoc corresponding to the backslash in the string literal.
This makes it possible for `ExprContextAnalyzer` in IDE to correctly detect when you are code-completing in a string interpolation and treat it as an `appendInterpolation` call.
The initialization of an instance property that has an attached
property delegate involves the initial value written on the property
declaration, the implicit memberwise initializer, and the default
arguments to the implicit memberwise initializer. Implement SILGen
support for each of these cases.
There is a small semantic change to the creation of the implicit
memberwise initializer due to SE-0242 (default arguments for the
memberwise initializer). Specifically, the memberwise initializer will
use the original property type for the parameter to memberwise
initializer when either of the following is true:
- The corresponding property has an initial value specified with the
`=` syntax, e.g., `@Lazy var i = 17`, or
- The corresponding property has no initial value, but the property
delegate type has an `init(initialValue:)`.
The specific case that changed is when a property has an initial value
specified as a direct initialization of the delegate *and* the
property delegate type has an `init(initialValue:)`, e.g.,
```swift
struct X {
@Lazy(closure: { ... })
var i: Int
}
```
Previously, this would have synthesized an initializer:
```swift
init(i: Int = ???) { ... }
```
However, there is no way for the initialization specified within the
declaration of i to be expressed via the default argument. Now, it
synthesizes an initializer:
```swift
init(i: Lazy<Int> = Lazy(closure: { ... }))
```
ASTDumper doesn’t have any way to look up key path component types in the constraint solver, so they’re currently shown as null. This change adds a hook to look them up and looks in the key path component’s FunctionResult locator, which is where subscripts already keep their return type.
