AnyFunctionType::Param carries around information about decomposed
parameters now. Information about default arguments must be computed
separately with swift::computeDefaultMap.
Keep track of the protocol conformances required to form a particular
solution. At the point where we apply a solution, mark each of those
conformances as "used" so we're sure they are complete for later
phases (SILGen, SIL optimizer, IRGen). This general mechanism makes
sure we don't miss any cases in CSApply, such as the multi-case
illustrated in the new test where CSApply doesn't form any AST notes
describing the type erasure in a function conversion, so it otherwise
wouldn't see the conformance to mark it "used".
Pavel went most of the way down this path to track conformances last
month for unrelated reasons (that didn't really pan out). Resurrect
his work to track conformances, but only use them to mark as "used".
Fixes rdar://problem/32111710.
Track outcomes of `conformsToProtocol` calls in `simplifyConformanceConstraints`
to be able to validate conformances when solution is formed to avoid returning
solutions with nominal types with invalid conformances to protocols.
ConstraintSolver::coerceToRValue() missed a bunch of cases where we
should be dealing with lvalues, e.g., tuples, "try" expressions, and
so on. Extend TypeChecker::coerceToRValue() to deal with the
expression type side-tables and ConstraintSolver::coerceToRValue() to
it.
Fixes rdar://problem/32700180, a crash-on-valid.
When applying a solution to an ApplyExpr, we have to coerce the
argument to the input type of the function. This is because the
solution succeeds if the argument is convertible to the
function's input, not just if they are equal.
We were forgetting to do that for the special case of a type(of:),
which has its own semantics.
Fixes <rdar://problem/32435723> and
<https://bugs.swift.org/browse/SR-5168>.
Conditional and forced downcasts enter a constraint that almost
always succeeds; only when applying the solution do we evaluate
the feasability of the cast and determine if it always succeeds,
always fails, or conditionally succeeds. This changes how the
resulting AST is represented and can also emit diagnostics.
If the conditional cast is at this stage determined to always
succeed, we treat it as an unconditional cast, going through
ExprRewriter::coerceToType() to build the AST for the coercion.
However conditional cast constraints don't enter the same
restrictions into the solution as unconditional casts do, so
coerceToType() would fall over if casting a Swift type to a CF
type by first bridging the Swift type to Objective-C.
Get around this by checking for this case explicitly when
lowering a CoerceExpr.
It feels like there's a more fundamental issue here with how
casts are modeled in the constraint solver, but I'm not going
to try understanding that now.
Fixes <rdar://problem/32227571>.
If we fail when doing a coercion while generating an OpenExistentialExpr
when applying a solution during type checking, make sure that the opaque
value on that OpenExistentialExpr is cleared.
We do not visit these during normal AST walks because they normally
appear in the subexpression held by the OpenExistentialExpr. In this
case, however, we replace that subexpression with an ErrorExpr which
means we will not visit the opaque value at all, so certain operations,
like setting the type on the opaque value, will never happen, and we can
run into problems later by code that assumes the type is set.
It seems reasonable to just clear these out in cases like this since
they are not reachable by any normal means.
We cannot model a type variable bound to the ExtInfo of a function
type in the constraint solver, which means we have a hard time
propagating noescape-ness in some cases.
Fixes <rdar://problem/31910280> and <rdar://problem/32409133>.
Situations where there is a contextual RawRepresentable type is
used incorrectly would produce `<Type>(rawValue: )` fix-it only
in cases where neither or both sides of the expression are optional.
Let's fix that by adding a fix-it for optional to contextual raw
value type conversion.
Resolves: rdar://problem/32431736
More updates to read and write types from a side table in the constraint
solver and only write back into expressions when we've finished type
checking an expression.
We still write directly into expressions, and will continue to do so
until all of the code has been updated.
With the introduction of special decl names, `Identifier getName()` on
`ValueDecl` will be removed and pushed down to nominal declarations
whose name is guaranteed not to be special. Prepare for this by calling
to `DeclBaseName getBaseName()` instead where appropriate.
If a lazy var has no declared type, we have to type check the
initializer to get a type before we can build the getter.
Then, the initializer is type checked as part of the getter
again.
Use the new SkipApplyingSolution flag when type checking for
the first time. We still end up doing redundant work, but by
not applying the solution we avoid feeding invalid AST nodes
back into the constraint solver.
This fixes some bad diagnostics and crashes.
Fixes <https://bugs.swift.org/browse/SR-2616> and
<rdar://problem/28313602>.
And make an attempt to use the constraint system's contextualType to bind type information; this makes things better but doesn't seem to be a complete solution for contextually typing key paths.
None of the clients of this care about distinguishing between immediate
failures in getWitnessType() vs. earlier errors that result in
getWitnessType() returning ErrorType, so simplify the interface by
having it always return Type() if there is a problem.
Update the clients that were not already checking for null result to do
so.
Fixes rdar://problem/32215763.
It's particularly likely someone will try to type `\(foo)`, which looks like a string interpolation segment, outside of a string literal, so give that case a special diagnostic. Fixes rdar://problem/32315365.
We need to strip inout/lvalue before casting the second parameter's type
to FunctionType.
There were also some verification issues and the fact that we weren't
allowing already-escaping closures to be passed to it (which is not
useful, but shouldn't result in an error and really awful
diagnostic). We can potentially look at diagnosing this with a warning
at some point in the future.
Fixes rdar://problem/32239354.
Now that SILGen can correctly lower lvalue accesses of
class existential payloads, remove a hack in Sema that
was simply doing the wrong thing.
Fixes <rdar://problem/31858378>.
This is a bit more robust and user-friendly than hoping more brittle recovery in SILGen or IRGen for unsupported components kicks in. rdar://problem/32200714
Replace `NameOfType foo = dyn_cast<NameOfType>(bar)` with DRY version `auto foo = dyn_cast<NameOfType>(bar)`.
The DRY auto version is by far the dominant form already used in the repo, so this PR merely brings the exceptional cases (redundant repetition form) in line with the dominant form (auto form).
See the [C++ Core Guidelines](https://github.com/isocpp/CppCoreGuidelines/blob/master/CppCoreGuidelines.md#es11-use-auto-to-avoid-redundant-repetition-of-type-names) for a general discussion on why to use `auto` to avoid redundant repetition of type names.
The warnings about deprecated @objc inference in Swift 3 mode can be a
bit annoying; and are mostly relevant to the migration workflow. Make
the warning emission a three-state switch:
* None (the default): don't warn about these issues.
* Minimal (-warn-swift3-objc-inference-minimal): warn about direct
uses of @objc entrypoints and provide "@objc" Fix-Its for them.
* Complete (-warn-swift3-objc-inference-complete): warn about all
cases where Swift 3 infers @objc but Swift 4 will not.
Fixes rdar://problem/31922278.
This introduces a few unfortunate things because the syntax is awkward.
In particular, the period and following token in \.[a], \.? and \.! are
token sequences that don't appear anywhere else in Swift, and so need
special handling. This is somewhat compounded by \foo.bar.baz possibly
being \(foo).bar.baz or \(foo.bar).baz (parens around the type), and,
furthermore, needing to distinguish \Foo?.bar from \Foo.?bar.
rdar://problem/31724243
This is tested in the next commit. This code path is about to
get more cleanup shortly to fix a miscompile with class
existentials (not just subclass existentials; an old problem),
so I'm not too concerned with adding the new conditinals here.
conversions and extend lifetimes over the call.
Apply this logic to string-to-pointer conversions as well as
array-to-pointer conversions.
Fix the AST verifier to not blow up on optional pointer conversions,
and make sure we SILGen them correctly. There's still an AST bug
here, but I'll fix that in a follow-up patch.
