These will be more useful once substitutions in protocol conformances
are moved to use interface types.
At first, these are only going to be used by the SIL optimizer.
When we are able to type check an expression this assert is fine,
although of little value. In the context of failed type checks, though,
it can be actively harmful.
The issue is that we can attempt to solve smaller parts of the
constraint system and assign contextual types (e.g. for the arguments of
a function) despite not being able to drill into members.
Some of the diagnostics we emit in these cases are not terribly useful,
and I've opened rdar://problem/27982012 with one example.
Resolves:
rdar://problem/25812474
rdar://problem/26589865
rdar://problem/27974638
Note that there was some non-obvious dead code here:
- We already drop conformance requirements on dependent types that
are the subject of same-type constraints, so we no longer have to
skip dependent types that are mapped to concrete types explicitly.
In fact, if this were not the case, other code that iterates over
the requirements of a GenericSignature would be wrong. The original
hack was added in 2014, I guess we fixed the ArchetypeBuilder
since then.
- We never end up here where the original type to substitute is a
recursive archetype. Recursive archetypes are not really a thing
that is implemented properly, and even in the compiler_crashers
collection this wasn't triggered.
- With the above two changes, the mapTypeIntoContext() call is not
necessary at all, which is nice because this is somewhat inefficient;
mapTypeIntoContext() walks all outer generic parameter lists to
find the archetype for the given dependent type.
This eliminates a pile of now-dead code in:
* The type checker, where we no longer have special cases for bridging conversions
* The expression ASTs, where we no longer need to distinguish bridging collection up/down casts
* SILGen, which no longer uses
Still to come is the removal of the
_(set|dictionary)Bridge(From|To)ObjectiveC(Conditional)? entrypoints
from the standard library. They're still used by some tests.
Simplify e.g., ASTContext::getBridgedToObjC(), which no longer needs
the optional return.
Eliminate the now-unused constraint kind for checking bridging to
Objective-C.
This commit built upon the work of Pull Request 3895. Apart from the
work to make the following work
```swift
let f: (Int, Int) -> Void = { x in } // this is now an error
```
This patch also implement the part 2 mentioned in the #3895
```swift
let g: ((Int, Int)) -> Void = { y in } // y should have type (Int, Int)
```
The problem here is that we would just emit 'invalid pattern'
instead of digging deeper, which meant that the fix-it for
qualified enum element access wasn't getting inserted for
more complex patterns, such as 'case X(let x)'.
Unfortunately, in the matching_patterns.swift test, we emit
too many diagnostics that are not really useful to figuring
out the problem, and the old 'invalid pattern' made more
sense. I'll work on some CSDiag tweaks to address this --
I think it makes more sense to dig there than just emit a
general 'invalid pattern' diagnostic anyway.
Fixes <rdar://problem/27684266>.
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.
Implements part of SE-0110. Single argument in closures will not be accepted if
there exists explicit type with a number of arguments that's not 1.
```swift
let f: (Int, Int) -> Void = { x in } // this is now an error
```
Note there's a second part of SE-0110 which could be considered additive,
which says one must add an extra pair of parens to specify a single arugment
type that is a tuple:
```swift
let g ((Int, Int)) -> Void = { y in } // y should have type (Int, Int)
```
This patch does not implement that part.
The isExplicitlyEscaping bit, though useful for printing,
unfortunately puts us in a position where we have different bit
patterns for the same type, and thus lose much of our type equivalence
checking for overriding, protocol conformance, etc., even if we were
to take subtyping into account. We need to drop it, relying on the
existing noescape bit alone to determine the type's semantics (at
least, as long as we continue to encode this information in the type
system).
This is a partial fix; we will now be excessively printing @escaping,
but the subsequent commits will correct this. For printing, we will
instead need to be more context-aware.
This helps when we end up re-typechecking an expression, which we seem
to be doing with 'lazy'. Specifically, it was causing type inference
for lazy variables to fail, but the same issue would have come up in
other contexts as well. Note that we also set function reference kinds
of DeclRefExprs and related in the process.
Extend the handling of function reference kinds to member references
(e.g., x.f), and therefore the logic for stripping argument labels. We
appear to be stripping argument labels from all of the places where it
is required.
The constraint system tracks the type accurately and may (in the
future) make adjustments to it; use that type directly rather than
recomputing something that might be different.
String literal expressions, as well as the magic literals #file and
tuple value that is then fed into one or two call expressions. For
string literals, that tuple value was implicitly splatted, breaking
AST invariants.
Instead, keep string literals and these magic literals that produce a
string as a single expression node, but store the declarations that
will be used to transform the raw literal into the complete
literal. SILGen will form the appropriate calls. This representation
is far simpler---the AST no longer has a bunch of implicit nodes---and
doesn't break AST invariants.
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.
Factor out the trailing storage of call arguments, since we'll need it
for a few different kinds of expression nodes. Use it for both
CallExpr (which already had this storage, albeit with a specialized
implementation) and now SubscriptExpr.
Yet another step on the way to SE-0111, capture the argument labels
(and their locations) directly in CallExpr, rather than depending on
them being part of the tuple argument.
When we are type-checking calls, subscripts, or other call-like
expressions, use the argument labels provided by the various
expression nodes rather than those encoded in the tuple type. This
means that argument label matching now matches the callee
declaration's argument labels against the argument labels, without
relying on encoding the argument labels within types in the AST.
This refactor is a stepping stone torward SE-0111.
Introduce several new factory methods to create CallExprs, and hide
the constructor. The primary reason for this refactor is to start
moving clients over to the factory method that takes the call
arguments separately from the argument labels. Internally, it
repackages those arguments into a TupleExpr or ParenExpr (as
appropriate) so the result ASTs are the same. However, this will make
it easier for us to tease out the arguments themselves in the
implementation of SE-0111.
If something isn't a class or bridgeable by value or error bridging, we can still fall back to universal bridging by the runtime. Make this available for manual use by an explicit `as AnyObject` cast.
This is needed for declaration-based resolution subscript expressions,
which is the basis for implementing default arguments in subscripts as
well as declaration-based argument labels.
Rather than synthesizing a global operator '==' for Equatable enums,
synthesize a member operator, which is more idiomatic and much
cleaner.
To make sure that these synthesized operators can actually be found,
start considering operator requirements in protocols
more generally in the type checker, so that, e.g., "myEnum == myEnum"
will type-check against Equatable.== and, on successful type-check,
will call the (newly-synthesized) witness for '=='. This both makes it
easier to make sure we find the operators in, e.g., complex multi-file
and lazy-type checking scenarios, and is a step toward the
type-checking improvements described in SE-0091.
This removes the logic which issued warnings when accessing enum
elements as instance members (SE-0036), making room for a new
implementation that will issue errors instead.
This reverts commit ae1058a39a.
This reverts commit dc24c2bd34.
Turns out Chris fixed the build but when I was looking at the bots, his fix had
not been tested yet, so I thought the tree was still red and was trying to
revert to green.
In Swift, default arguments are associated with a function or
initializer's declaration---not with its type. This was not always the
case, and TupleType's ability to store a default argument kind is a
messy holdover from those dark times.
Eliminate the default argument kind from TupleType, which involves
migrating a few more clients over to declaration-centric handling of
default arguments. Doing so is usually a bug-fix anyway: without the
declaration, one didn't really have
The SILGen test changes are due to a name-mangling fix that fell out
of this change: a tuple type is mangled differently than a non-tuple
type, and having a default argument would make the parameter list of a
single-parameter function into a tuple type. Hence,
func foo(x: Int = 5)
would get a different mangling from
func foo(x: Int)
even though we didn't actually allow overloading.
Fixes rdar://problem/24016341, and helps us along the way to SE-0111
(removing the significance of argument labels) because argument labels
are also declaration-centric, and need the same information.
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.
A given Objective-C error enum, which is effectively an NS_ENUM that
specifies its corresponding error domain, will now be mapped to an
ErrorProtocol-conforming struct that wraps an NSError, much like
NSCocoaError does. The actual enum is mapped to a nested "Code"
enum. For example, CoreLocation's CLError becomes:
struct CLError : ErrorProtocol {
let _nsError: NSError
// ...
@objc enum Code : Int {
case ...
}
}
This implements bullet (2) in the proposed solution of SE-0112, so
that Cocoa error types are mapped into structures that maintain the
underlying NSError to allow more information to be extracted from it.
