Force unwrapping the expression and propagating that type down to the
rest of the tree causes crashes when we go to request a different set
of protocols than we were expecting from it later. Make this
transformation local to the apply instead.
Capture checks were being elided inside of defer bodies because we
are using SourceLoc-based analyses on DeferStmt's, which generate
FuncDecls that have implicit bodies. This resulted in a numberof
strange situations wherein declrefs could "time travel" backwards and be
captured before they were declared. Use the source location of
the defer's func's body to make sure we analyze them correctly.
This fix is brittle and should be replaced by ASTScope when such tech
becomes available.
Invalid ASTs like the one in 28625 cause Parse to generate an AST that
looks a heck of a lot like a constructor call, however this makes no
sense as the type in question is a TupleType and lookup asserts in such
cases. Guard against this so we don't crash diagnosing.
This used to cause SILGen to capture and subsequently load `self` as a
constant. Then, when the super call was SILGen’d, it assumed that
`self` would be loaded Boxed. Diagnose before hitting SILGen so we
don’t have to pollute Lowering with code that handles `self` in this
odd position.
Crashers fixed are minor logic errors:
Patterns: Crash occurred when requesting the range of a created
Pattern. Validity of the range should be checked before returning it
to keep the entire range valid or invalid but never both.
ParseExpr/ParsePattern: The same fixes as the ones provided in #6319
CSDiag: The generic visitor needn’t look through TypeVarTypes either.
This patch contains several intertwined changes:
- Remove some unnecessary complexity and duplication.
- Adds a new TypeChecker::lookupUnqualifiedType() which bypasses most of
the logic in TypeChecker::lookupUnqualified(), such as the
LookupResultBuilder. Use this when resolving unqualified references
to types.
- Fixes for generic typealiases to better preserve the type parameters of
the parent type, and clean up the logic for applying the inner generic
arguments. Some uses of generic typealiases that used to crash now work,
and those tests have been uncommented.
- Avoid an unnecessary desugaring of TypeAliasDecls which map directly
to GenericTypeParamTypes. Once again this perturbs the source-stability
test.
- When looking up a nested type of a base class with a derived class base,
always use the base class as the parent of the nested type. This fixes
a recent regression where in some cases we were using the wrong parent.
Fixes <rdar://problem/29782186>.
The handling of SIL box types in both deserialization and in the SIL
parser assumed that the number of substitutions in the box type would
be equivalent to the number of generic parameters. This assumption is
incorrect when the generic signature adds requirements to an
associated type.
Fixes rdar://problem/29740594.
Same as previous, but for availability. Again, it would be great
to get some follow-up work to make these into warnings instead of
just silencing them, but restoring source compatibility is the
first priority.
Rest of rdar://problem/29782505.
Swift 3 just looked at what types we ended up with, not what types
we had to traverse to get there. Preserve this behavior for source
compatibility. (We ought to be able to warn, at least, but for now
getting source compatibility back is most important.)
Part of rdar://problem/29782505.
DiagnosticArguments store a StringRef, rather than a
std::string. Passing a temporary string when creating a diagnostic,
and then holding on to the InFlightDiagnostic, means that the
StringRef will maintain a reference to a destroyed temporary string.
Dodge the issue locally by moving the string out to its own variable
with a longer lifetime, because only this diagnostic seems to
be affected. We should fix this architecturally later.
Fixes SR-2757.
Variables in capture lists are treated as 'let' constants, which can
result in misleading, incorrect diagnostics. Mark them as such in order
to produce better diagnostics, by adding an extra parameter to the
VarDecl initializer.
Alternatively, these variables could be marked as implicit, but that
results in other diagnostic problems: capture list variables that are
never used produce warnings, but these warnings aren't normally emitted for
implicit variables. Other assertions in the compiler also misfire when
these variables are treated as implicit.
Another alternative would be to walk up the AST and determine whether
the `VarDecl`, but there doesn't appear to be a way to do so.
The default behavior was looking *through* the ForceValueExpr, so in this test case the LinkedExprAnalyzer thought it was dealing with Optional<Double> rather than Double. Resolves SR-1122.
This gives us much better diagnostics around things like
escaping-mismatched function parameters which would previously skip
this and produce bogus invalid conversion errors between “identical”
types.
Marking such type variable as "must be materializable" is going to explicitly
enforce the notion that assignment destination type can only be materializable
and situations like source expression is InOutExpr are incorrect.
If T0 must be materializable and it's bound to T1, when matching T0 to
possibly optinal T1, look through optinality when setting materializability of the binding.
If return expression uses closure parameters, which have/are
type variables, such means that we won't be be able to
type-check result correctly and, unfornutately,
we are going to leak type variables from the parent
constraint system through declaration types.
In `checkTopLevelErrorHandling` if apply expression did not type-check,
don't attempt walking inside of it. This accounts for the fact that we don't
erase types without type variables to enable better code complication,
so DeclRefExpr(s) or ApplyExpr with DeclRefExpr as function contained
inside would have their types preserved, which makes classification
incorrect.
There might be erroneous typealiases present which re-define literal types,
so when trying to type-check something that supposed to confirm to erroneous
redeclaration by default, ignore it.
When running diagnostics for single expression closures,
explicitly disallow to produce solutions with unresolved type variables,
because there is no auxiliary logic which would handle that and it's
better to allow failure diagnosis to run directly on the closure body.
Currently isAnyHashableType method validates only structs but
it doesn't account for situation when type is represented via type
variable with type already fixed to AnyHashable, that results in
infinite loop in the solver because restriction [hashable-to-
anyhashable] is going to add new type variable recursively.
Instead of returning empty type when RValue destination of the assignment
could not be determined, let's return it unresolved directly instead and
let it be handled by coerceToType, which is going to produce special expression
(UnresolvedTypeConversionExpression) which facilitates better diagnostics.
Obtain type of the result expression without applying solutions,
because otherwise this might result in leaking of type variables,
since we are not reseting result statement and if expression is
sucessfully type-checked its type cleanup is going to be disabled
(we are allowing unresolved types), and as a side-effect it might
also be transformed e.g. OverloadedDeclRefExpr -> DeclRefExpr.
withoutActuallyEscaping has a signature like `<T..., U, V, W> (@nonescaping (T...) throws<U> -> V, (@escaping (T...) throws<U> -> V) -> W) -> W, but our type system for functions unfortunately isn't quite that expressive yet, so we need to special-case it. Set up the necessary type system when resolving an overload set to reference withoutActuallyEscaping, and if a type check succeeds, build a MakeTemporarilyEscapableExpr to represent it in the type-checked AST.
`type(of:)` has behavior whose type isn't directly representable in Swift's type system, since it produces both concrete and existential metatypes. In Swift 3 we put in a parser hack to turn `type(of: <expr>)` into a DynamicTypeExpr, but this effectively made `type(of:)` a reserved name. It's a bit more principled to put `Swift.type(of:)` on the same level as other declarations, even with its special-case type system behavior, and we can do this by special-casing the type system we produce during overload resolution if `Swift.type(of:)` shows up in an overload set. This also lays groundwork for handling other declarations we want to ostensibly behave like normal declarations but with otherwise inexpressible types, viz. `withoutActuallyEscaping` from SE-0110.
We were dropping the substitutions required to call the default
argument generator on the floor, when the correct solution is to
remap them to substitutions in terms of the base class signature.
Fixes <rdar://problem/29721571>.
The prior formulation of bridging conversions allowed conversion to
more-optional types, e.g., converting an "NSDate" to "Date?", which
was broken by my recent refactoring in this area. Allow bridging
conversions to more-optional types by introducing extra optional
injections at the end.
Fixes rdar://problem/29780527.
These two comments were added in 2013 and 2012, respectively, most
likely referring to a large patch of code below them. That code was
subsequently deleted in 2014 (0e00f513d).
Remove the obsolete comments, since the performance improvements they
describe can no longer be found in the same file.
