Since the return value of getAccessor() depends on mutable state, it
does not make sense in the request evaluator world. Let's begin by
removing some utility methods derived from getAccessor(), replacing
calls to them with calls to getAccessor().
Extend the "type check function body" request to also cover the case
where we have a specific ending source location. Fold all of this
functionality into a single request, so we consistently go through a
request to compute a type-checked function body.
This improves the diagnostic for trailing closures in statement conditions to catch cases where one or more trailing closures are used in a chain composed of multiple calls
This calculates a result directly from the function's result type
instead of checking a bit that was previously set by the type
checker. Also, always returns true for constructors to simplify
some callers.
There's no way to spell an opaque type in a cast, and that means
there's no way to force the conversion today (even if you know the
types are dynamically the same).
Part of rdar://problem/50346954
It's okay to have two function parameters with the same external label, as long as the internal labels are different. If not, we already emit a diagnostic for it, so no need to check
- In Sema, don't traverse nested declarations while deducing the opaque return type. This would
cause returns inside nested functions to clobber the return type of the outer function.
- In IRGen, walk the list of opaque return types we keep in the SourceFile already for type
reconstruction, instead of trying to visit them ad-hoc as part of walking the AST, since
IRGen doesn't normally walk the bodies of function decls directly.
Fixes rdar://problem/50459091
The main fixes here are:
- we weren't looking through open-existentials in the l-value
- we weren't handling mutating gets correctly unless CSApply wrapped
the base in an InOutExpr, which seems to be multifile-sensitive
- we were missing diagnostics in some cases involving subscripts
A better fix would be to re-introduce LValueAccessKind, but I wanted
a workable short-term fix that I could try to get into 5.1.
Fixes rdar://49482742, which is specific to the lazy-getter problem.
Specifically the bad pattern was:
```
for (auto *vd : *caseStmt->getCaseBodyVariables()) { ... }
```
The problem is that the optional is not lifetime extended over the for loop. To
work around this, I changed the API of CaseStmt's getCaseBodyVariable methods to
never return the inner Optional<MutableArrayRef<T>>. Now we have the following 3
methods (ignoring const differences):
1. CaseStmt::hasCaseBodyVariables().
2. CaseStmt::getCaseBodyVariables(). Asserts if the case body variable array was
never specified.
3. CaseStmt::getCaseBodyVariablesOrEmptyArray(). Returns either the case body
variables array or an empty array if we were never given any case body
variable array.
This should prevent anyone else in the future from hitting this type of bug.
radar://49609717
We set the type of ParamDecls when applying solutions in the normal path, but
sometimes code completion will type check an expression inside a closure without
checking the outer expression. In this case, we may have inferred a type for
the ParamDecl, but we don't write it back.
Instead, just look at the DeclRefExpr's type.
Fixes <rdar://problem/42098113>.
This is a defensive move to avoid duplicated work and guard against crashes
when a multi-expression closure body or TapExpr has not been type checked yet.
Fixes <rdar://problem/48852402>.
Instead of building ArgumentShuffleExprs, lets just build a TupleExpr,
with explicit representation of collected varargs and default
arguments.
This isn't quite as elegant as it should be, because when re-typechecking,
SanitizeExpr needs to restore the 'old' parameter list by stripping out
the nodes inserted by type checking. However that hackery is all isolated
in one place and will go away soon.
Note that there's a minor change the generated SIL. Caller default
arguments (#file, #line, etc) are no longer delayed and are instead
evaluated in their usual argument position. I don't believe this actually
results in an observable change in behavior, but if it turns out to be
a problem, we can pretty easily change it back to the old behavior with a
bit of extra work.
TupleShuffleExpr could not express the full range of tuple conversions that
were accepted by the constraint solver; in particular, while it could re-order
elements or introduce and eliminate labels, it could not convert the tuple
element types to their supertypes.
This was the source of the annoying "cannot express tuple conversion"
diagnostic.
Replace TupleShuffleExpr with DestructureTupleExpr, which evaluates a
source expression of tuple type and binds its elements to OpaqueValueExprs.
The DestructureTupleExpr's result expression can then produce an arbitrary
value written in terms of these OpaqueValueExprs, as long as each
OpaqueValueExpr is used exactly once.
This is sufficient to express conversions such as (Int, Float) => (Int?, Any),
as well as the various cases that were already supported, such as
(x: Int, y: Float) => (y: Float, x: Int).
https://bugs.swift.org/browse/SR-2672, rdar://problem/12340004
Right now we use TupleShuffleExpr for two completely different things:
- Tuple conversions, where elements can be re-ordered and labels can be
introduced/eliminated
- Complex argument lists, involving default arguments or varargs
The first case does not allow default arguments or varargs, and the
second case does not allow re-ordering or introduction/elimination
of labels. Furthermore, the first case has a representation limitation
that prevents us from expressing tuple conversions that change the
type of tuple elements.
For all these reasons, it is better if we use two separate Expr kinds
for these purposes. For now, just make an identical copy of
TupleShuffleExpr and call it ArgumentShuffleExpr. In CSApply, use
ArgumentShuffleExpr when forming the arguments to a call, and keep
using TupleShuffleExpr for tuple conversions. Each usage of
TupleShuffleExpr has been audited to see if it should instead look at
ArgumentShuffleExpr.
In sequent commits I plan on redesigning TupleShuffleExpr to correctly
represent all tuple conversions without any unnecessary baggage.
Longer term, we actually want to change the representation of CallExpr
to directly store an argument list; then instead of a single child
expression that must be a ParenExpr, TupleExpr or ArgumentShuffleExpr,
all CallExprs will have a uniform representation and ArgumentShuffleExpr
will go away altogether. This should reduce memory usage and radically
simplify parts of SILGen.
We weren't renaming all occurrences of 'x' in the cases like the below:
case .first(let x), .second(let x):
print("foo \(x)")
fallthrough
case .third(let x):
print("bar \(x)")
We would previously only rename occurrences within the case statement the query
was made in (ignoring fallthroughs) and for cases with multiple patterns (as in
the first case above) we would only rename the occurrence in the first pattern.
This is in preparation for fixing issues around SILGenPattern fallthrough
emission and bad rename/edit all in scope of case stmt var decls. Specifically,
I am going to ensure that we can get from any VarDecl in the following to any
other VarDecl:
switch x {
case .a(let v1, let v2), .b(let v1, let v2):
...
fallthrough
case .c(let v1, let v2), .d(let v1, let v2):
...
}
This will be done by:
1. Pointing the var decls in .d at the corresponding var decls in .c.
2. Pointing the var decls in .c at the corresponding var decls in .b.
3. Pointing the var decls in .b at the corresponding var decls in .a.
4. Pointing the var decls in .a at the case stmt. Recognizing that we are asking
for the next VarDecl, but have a case stmt, we check if we have a fallthrough
case stmt. If so, follow down the fallthrough case stmts until you find a
fallthrough case stmt that doesn't fallthrough itself and then return the
corresponding var decl in the last case label item in that var decl (in the
above .d).
In a subsequent commit I am going to add case body var decls. The only change as
a result of that is that I will insert them into the VarDecl double linked list
after the last case var decl of each case stmt.
Add assetion along with defensive guard to avoid crashing in release
build. Hopefully, sourcekitd Stress Tester find a reproducer for the
crash.
rdar://problem/47895109
Instead of constructing calls to
ExpressibleByNilLiteral.init(nilLiteral: ()) in CSApply.cpp, just
annotate NilLiteralExpr with the selected construtor and do the actual
construction during SILGen.
For context, StringLiteralExpr already behaves this way.
The diagnostics for `variable_never_mutated` always suggests
changing `var` to `let`, which is misleading in case of
for-each loops where explicitly immutable context applies.
This patch adds some variety to the message to make it appropriate.
Resolves: SR-9732
