These changes make the following improvements to how we generate diagnostics for expression typecheck failure:
- Customizing a diagnostic for a specific expression kind is as easy as adding a new method to the FailureDiagnosis class,
and does not require intimate knowledge of the constraint solver’s inner workings.
- As part of this patch, I’ve introduced specialized diagnostics for call, binop, unop, subscript, assignment and inout
expressions, but we can go pretty far with this.
- This also opens up the possibility to customize diagnostics not just for the expression kind, but for the specific types
involved as well.
- For the purpose of presenting accurate type info, partially-specialized subexpressions are individually re-typechecked
free of any contextual types. This allows us to:
- Properly surface subexpression errors.
- Almost completely avoid any type variables in our diagnostics. In cases where they could not be eliminated, we now
substitute in "_".
- More accurately indicate the sources of errors.
- We do a much better job of diagnosing disjunction failures. (So no more nonsensical ‘UInt8’ error messages.)
- We now present reasonable error messages for overload resolution failures, informing the user of partially-matching
parameter lists when possible.
At the very least, these changes address the following bugs:
<rdar://problem/15863738> More information needed in type-checking error messages
<rdar://problem/16306600> QoI: passing a 'let' value as an inout results in an unfriendly diagnostic
<rdar://problem/16449805> Wrong error for struct-to-protocol downcast
<rdar://problem/16699932> improve type checker diagnostic when passing Double to function taking a Float
<rdar://problem/16707914> fatal error: Can't unwrap Optional.None…Optional.swift, line 75 running Master-Detail Swift app built from template
<rdar://problem/16785829> Inout parameter fixit
<rdar://problem/16900438> We shouldn't leak the internal type placeholder
<rdar://problem/16909379> confusing type check diagnostics
<rdar://problem/16951521> Extra arguments to functions result in an unhelpful error
<rdar://problem/16971025> Two Terrible Diagnostics
<rdar://problem/17007804> $T2 in compiler error string
<rdar://problem/17027483> Terrible diagnostic
<rdar://problem/17083239> Mysterious error using find() with Foundation types
<rdar://problem/17149771> Diagnostic for closure with no inferred return value leaks type variables
<rdar://problem/17212371> Swift poorly-worded error message when overload resolution fails on return type
<rdar://problem/17236976> QoI: Swift error for incorrectly typed parameter is confusing/misleading
<rdar://problem/17304200> Wrong error for non-self-conforming protocols
<rdar://problem/17321369> better error message for inout protocols
<rdar://problem/17539380> Swift error seems wrong
<rdar://problem/17559593> Bogus locationless "treating a forced downcast to 'NSData' as optional will never produce 'nil'" warning
<rdar://problem/17567973> 32-bit error message is really far from the mark: error: missing argument for parameter 'withFont' in call
<rdar://problem/17671058> Wrong error message: "Missing argument for parameter 'completion' in call"
<rdar://problem/17704609> Float is not convertible to UInt8
<rdar://problem/17705424> Poor error reporting for passing Doubles to NSColor: extra argument 'red' in call
<rdar://problem/17743603> Swift compiler gives misleading error message in "NSLayoutConstraint.constraintsWithVisualFormat("x", options: 123, metrics: nil, views: views)"
<rdar://problem/17784167> application of operator to generic type results in odd diagnostic
<rdar://problem/17801696> Awful diagnostic trying to construct an Int when .Int is around
<rdar://problem/17863882> cannot convert the expression's type '()' to type 'Seq'
<rdar://problem/17865869> "has different argument names" diagnostic when parameter defaulted-ness differs
<rdar://problem/17937593> Unclear error message for empty array literal without type context
<rdar://problem/17943023> QoI: compiler displays wrong error when a float is provided to a Int16 parameter in init method
<rdar://problem/17951148> Improve error messages for expressions inside if statements by pre-evaluating outside the 'if'
<rdar://problem/18057815> Unhelpful Swift error message
<rdar://problem/18077468> Incorrect argument label for insertSubview(...)
<rdar://problem/18079213> 'T1' is not identical to 'T2' lacks directionality
<rdar://problem/18086470> Confusing Swift error message: error: 'T' is not convertible to 'MirrorDisposition'
<rdar://problem/18098995> QoI: Unhelpful compiler error when leaving off an & on an inout parameter
<rdar://problem/18104379> Terrible error message
<rdar://problem/18121897> unexpected low-level error on assignment to immutable value through array writeback
<rdar://problem/18123596> unexpected error on self. capture inside class method
<rdar://problem/18152074> QoI: Improve diagnostic for type mismatch in dictionary subscripting
<rdar://problem/18242160> There could be a better error message when using [] instead of [:]
<rdar://problem/18242812> 6A1021a : Type variable leaked
<rdar://problem/18331819> Unclear error message when trying to set an element of an array constant (Swift)
<rdar://problem/18414834> Bad diagnostics example
<rdar://problem/18422468> Calculation of constant value yields unexplainable error
<rdar://problem/18427217> Misleading error message makes debugging difficult
<rdar://problem/18439742> Misleading error: "cannot invoke" mentions completely unrelated types as arguments
<rdar://problem/18535804> Wrong compiler error from swift compiler
<rdar://problem/18567914> Xcode 6.1. GM, Swift, assignment from Int64 to NSNumber. Warning shown as problem with UInt8
<rdar://problem/18784027> Negating Int? Yields Float
<rdar://problem/17691565> attempt to modify a 'let' variable with ++ results in typecheck error about @lvalue Float
<rdar://problem/17164001> "++" on let value could give a better error message
Swift SVN r23782
a capture list hung off the CaptureExpr it was associated with. This made
sense lexically (since a capture list is nested inside of the closure) but
not semantically. Semantically, the capture list initializers are evaluated
outside the closure, the variables are bound to those values, then the closure
captures the newly bound values.
To directly represent this, represent captures with a new CaptureListExpr node,
which contains the ClosureExpr inside of it. This correctly models the semantic
relationship, and makes sure that AST walkers all process the initializers of the
capture list as being *outside* of the closure.
This fixes rdar://19146761 and probably others.
Swift SVN r23756
Add the following functionality to the Swift compiler:
* covariant subtyping of Set
* upcasting, downcasting of Set
* automatic bridging between Set and NSSet, including
* NSSet params/return values in ObjC are imported as Set<NSObject>
* Set params/return values in Swift are visible to ObjC as NSSet
<rdar://problem/18853078> Implement Set<T> up and downcasting
Swift SVN r23751
Specifically, it's not when
- the conformance is being used within a function body (test included)
- the conformance is being used for or within a private type (test included)
- the conformance is being used to generate a diagnostic string
We're still a bit imprecise in some places (checking ObjC bridging), but
in general this means less of an issue for checking literals.
Swift SVN r23700
--This line, and those bel that ow, will be ignored--
M test/Parse/optional.swift
M test/ClangModules/Security_test.swift
M test/expr/expressions.swift
M include/swift/AST/DiagnosticsSema.def
M lib/Sema/CSApply.cpp
Swift SVN r23685
This adds a new parameter to TypeChecker::lookupMember to specify when
something is known-private, which can then be passed along to
DeclContext::lookupQualified. This makes many of the existing member
lookup dependencies in the reference-dependencies.swift test correctly
count as private.
Swift SVN r23631
Make it easier to get the "do I expect null ProtocolConformance* pointers" logic right. Audit existing uses of is<ArchetypeType>() for this purpose.
Swift SVN r23479
This makes sure we get the same checking for initializer delegation in
structs/enums as we do for classes, fixing rdar://problem/18458622.
Swift SVN r23128
We'd like to kill this enum off eventually, since the runtime inevitably needs to be able to handle arbitrary checked casts in opaque contexts, and SILGen and IRGen can deal with picking more optimal runtime entry points for specific casts. Only the container bridging kinds are still depended on anymore, and even those ought to eventually be handlable by the runtime in 'x as T' situations. NFC yet.
Swift SVN r23127
These are very-slightly-but-not-significantly faster; there's no need to
go through the intermediate layer of unqualified lookup.
No functionality change.
Swift SVN r22872
This commit adds checking of declarations with potentially unavailable types to
the existing checking for explicitly unavailable types. At the moment, these
two checking mechanisms are separate -- I will unify them in a future commit.
This commit removes the TypeExpr-based checking added in r22651; such checks
are now superfluous.
Swift SVN r22679
This commit adds availability checking for references to classes in Sema. We
now emit a diagnostic when a potentially unavailable class is referenced
in an expression, either directly (via a TypeExpr) or as the result of being
substituted as a replacement type in a call to a generic function. This
latter check is needed at the callsite because the callee may use its
formal type parameter to get at the metadata for the type.
This commit does not check declarations of variables, etc., with unavailable
types -- this will come in a later patch.
Swift SVN r22651
This commit adds availability checking for properties to Sema. When
EnableExperimentalAvailabilityChecking is enabled, we now emit a diagnostic
when a potentially unavailable property is accessed. To support this, we
now build type refinement contexts for most ValueDecls.
Swift SVN r22622
This patch adds diagnostics for initializers that are potentially unavailable.
It does not treat such initializers as optionals, even when
EnableExperimentalUnavailableAsOptional is true -- there is some tricky
interaction with failable initializers that still needs to be worked out.
Swift SVN r22548
This commit modifies Sema to add type checking for potentially unavailable
method references. We now record the reason for method unavailability when
recording a potential overload choice during member constraint simplification
and either diagnose or lift to an optional type during CSApply. This commit also
generalizes UnavailableToOptionalExpr to take an arbitrary subexpression.
This commit does not address potentially unavailable properties, initializers,
or dynamic member references.
Swift SVN r22508
This commit also factors out some common checking and diagnostic code; it
additionally moves diagnostic emission for unavailable references from CSGen to
CSApply.
Swift SVN r22447
This commit adds tracking of the reason a declaration reference is potentially
unavailable to the UnavailableToOptionalExpr AST node and to OverloadChoice. We
will use this reason during SILGen to emit the appropriate run-time check and
during typechecking to provide more helpful diagnostics.
To keep OverloadChoice as small as possible, we encode the reason as an index
into a vector of reasons stored in a given instance of ConstraintSystem (this is
the same approach that Fix takes).
This commit adds Sema/OverloadChoice.cpp (for the parts of OverloadChoice that
now rely on ConstraintSystem) and AST/Availability.h (to bring in
availability-related structures without TypeRefinementContext).
Swift SVN r22377
There are a lot of different ways to interpret the
"kind" of an access. This enum specifically dictates
the semantic rules for an access: direct-to-storage
and direct-to-accessor accesses may be semantically
different from ordinary accesses, e.g. if there are
observers or overrides.
Swift SVN r22290
This patch adds the ability (-enable-experimental-unavailable-as-optional) to
treat potentially unavailable declarations as if they had optional types. For
the moment, this is only implemented for global variables.
The high-level approach is to (1) record the potential unavailability of a
declaration reference in the overload choice during constraint generation; (2)
treat the declaration as if it had an optional type during overload resolution
(this is similar to how optional protocol members are treated); and (3) add an
implicit conversion (UnavailableToOptionalExpr) during constraint application
to represent the run-time availability check and optional injection.
This patch does not implement SILGen for UnavailableToOptionalExpr.
Swift SVN r22245
With this, we're now using initializer requirements rather than
"convertFromXXX" requirements everywhere, addressing the rest of
rdar://problem/18154091. r22176 eliminated the performance penalty
that prevented this change from sticking earlier.
Swift SVN r22177
Calls to fromRaw are replaced with uses of the new failable
initializer init(rawValue:). Similarly, calls to toRaw are replaced
with uses of the rawValue property. Fixes rdar://problem/18357647.
Swift SVN r22164
The initializer requirement is causing too much exponential behavior
in the constraint solver. We'll have to address that
first. Re-instating this change is tracked by rdar://problem/18381811.
Swift SVN r22080
With this, we're now using initializer requirements rather than
"convertFromXXX" requirements everywhere, addressing the rest of
rdar://problem/18154091.
Swift SVN r22078
Conforming to BooleanLiteralConvertible now requires
init(booleanLiteral: Bool)
rather than
static func convertFromBooleanLiteral(value: Bool) -> Self
This posed a problem for NSNumber's conformance to
BooleanLiteralConvertible. A class needs a required initializer to
satisfy an initializer requirement, but one cannot add a required
initializer via an extension. To that end, we hack the Clang importer
to import NSNumber's initWithBool with the name
init(booleanLiteral:)
and add back the expected init(bool:) initializer in the
overlay. These tricks make NSNumber even harder to subclass, but we
don't really care: it's nearly impossible to do well anyway, and is
generally a Bad Idea.
Part of rdar://problem/18154091.
Swift SVN r21961
Locators that refer to opened type parameters now carry information
about the source location where we needed to open the type, so that
(for example) we can trace an opened type parameter back to the
location it was opened. As part of this, eliminate the "rootExpr"
fallback, because we're threading constraint locators everywhere.
This is infrastructural, and should be NFC.
Swift SVN r21919
This patch adds a new 'pound_os' token, a new case for it in parseExprPostfix, and parsing of platform version constraints, e.g., OSX >= 10.10.
It also adds enough type checking and SILGen to get the parsing tests to run without triggering "Unimplemented" assertions.
Swift SVN r21865
