* [Sema] Implementing is runtime check always true diagnostic as a fix
* [AST] Implement getWithoutThrows on function type
* [CSSimplify] Detect that checked cast types conversion is always true and record warning fix
* [test] Some additional test cases for SR-13789
* [Sema] Fixing typo on fix name
* [Sema] Move and adjust the ConditionalCast diagnostics to the fix format
* [Sema] Remove some checked cast diagnostics from check constraints and move to fix
* [Sema] Renaming checked cast coercible types fix
* [Sema] Some adjustments and rewrite on the logic for downcast record fix
* [Sema] Move logic of runtime function type to AllowUnsupportedRuntimeCheckedCast::attempt
* [Sema] Abstract checked cast fix logic to static function and minor adjustments
* [Sema] Renamings from review
And provide better semantic background by surrounding 'nil' in ticks when it is referred to as a value
Added missing tests for certain cases involving nil capitalization
Stop creating ImplicitlyUnwrappedOptional<T> so that we can remove it
from the type system.
Enable the code that generates disjunctions for Optional<T> and
rewrites expressions based on the original declared type being 'T!'.
Most of the changes supporting this were previously merged to master,
but some things were difficult to merge to master without actually
removing IUOs from the type system:
- Dynamic member lookup and dynamic subscripting
- Changes to ensure the bridging peephole still works
Past commits have attempted to retain as much fidelity with how we
were printing things as possible. There are some cases where we still
are not printing things the same way:
- In diagnostics we will print '?' rather than '!'
- Some SourceKit and Code Completion output where we print a Type
rather than Decl.
Things like module printing via swift-ide-test attempt to print '!'
any place that we now have Optional types that were declared as IUOs.
There are some diagnostics regressions related to the fact that we can
no longer "look through" IUOs. For the same reason some output and
functionality changes in Code Completion. I have an idea of how we can
restore these, and have opened a bug to investigate doing so.
There are some small source compatibility breaks that result from
this change:
- Results of dynamic lookup that are themselves declared IUO can in
rare circumstances be inferred differently. This shows up in
test/ClangImporter/objc_parse.swift, where we have
var optStr = obj.nsstringProperty
Rather than inferring optStr to be 'String!?', we now infer this to
be 'String??', which is in line with the expectations of SE-0054.
The fact that we were only inferring the outermost IUO to be an
Optional in Swift 4 was a result of the incomplete implementation of
SE-0054 as opposed to a particular design. This should rarely cause
problems since in the common-case of actually using the property rather
than just assigning it to a value with inferred type, we will behave
the same way.
- Overloading functions with inout parameters strictly by a difference
in optionality (i.e. Optional<T> vs. ImplicitlyUnwrappedOptional<T>)
will result in an error rather than the diagnostic that was added
in Swift 4.1.
- Any place where '!' was being used where it wasn't supposed to be
allowed by SE-0054 will now treat the '!' as if it were '?'.
Swift 4.1 generates warnings for these saying that putting '!'
in that location is deprecated. These locations include for example
typealiases or any place where '!' is nested in another type like
`Int!?` or `[Int!]`.
This commit effectively means ImplicitlyUnwrappedOptional<T> is no
longer part of the type system, although I haven't actually removed
all of the code dealing with it yet.
ImplicitlyUnwrappedOptional<T> is is dead, long live implicitly
unwrapped Optional<T>!
Resolves rdar://problem/33272674.
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.
common standard library operators. This is progress towards:
<rdar://problem/27457457> [Type checker] Diagnose unsavory optional injections
but there is more work to be done here.
This is the hack that has been used to reject things like:
var i: Int = ...
if i == nil { }
in the past.
The hack is inconsistent with normal treatment of mixed optional &
non-optional operands, and will be replaced with a warning instead of
treating it as a failure to type check.
There is still a case that we still fail type checking on -
Unsafe*Pointer<> compares to nil. That will be addressed by a separate
commit.
The new warning will be addressed by rdar://problem/27457457. When the
new warnings are updated the test cases modified here will again need to
be updated based on the text of the new warning.
<rdar://problem/18397777> QoI: special case comparisons with nil
<rdar://problem/18042123> QoI: Fixit for "if !optional" should suggest "if optional == nil"
Swift SVN r31204
directly into the diagnostics subsystem. This ensures a more consistent
treatment of type printing (e.g. catches a case where a diagnostic didn't
single quote the type) and gives these diagnostics access to "aka".
Swift SVN r30609
facilities used by operators etc. This required a bunch of changes to make
the diagnostics changes strictly an improvement:
- Teach the new path about calls to TypeExprs.
- Teach evaluateCloseness some simple things about varargs.
- Make the generic diagnosis logic produce a better error when there is
exactly one match.
Overall, the resultant diagnostics are a step forward: we now produce candidate
set notes more uniformly, and the messages about some existing ones are
more specific. This is just another stepping stone towards progress though.
Swift SVN r30057
expressions. Broadening from callexpr to apply expr (picking up operators) improves
several diagnostics in the testsuite, and is important to avoid regressions from an
upcoming patch.
Swift SVN r29821
Most tests were using %swift or similar substitutions, which did not
include the target triple and SDK. The driver was defaulting to the
host OS. Thus, we could not run the tests when the standard library was
not built for OS X.
Swift SVN r24504
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
Start capitalizing on some of the new diagnostic machinery in a few different ways:
- When mining constraints for type information, utilize constraints "favored" by the overload resolution process.
- When printing type variables, if the variable was created by opening a literal expression, utilize the literal
default type or conformance if possible.
- Utilize syntactic information when crafting diagnostics:
- If the constraint miner can produce a better diagnostic than the recorded failure, diagnose via constraints.
- Factor in the expression kind when choosing which types to include in a diagnostic message.
- Start customizing diagnostics based on the amount of type data available.
What does all this mean?
- Fewer type variables leaking into diagnostic messages.
- Far better diagnostics for overload resolution failures. Specifically, we now print proper argument type data
for failed function calls.
- No more "'Foo' is not convertible to 'Foo'" error messages
- A greater emphasis on type data means less dependence on the ordering of failed constraints. This means fewer
inscrutable diagnostics complaining about 'UInt8' when all the constituent expressions are of type Float.
So we still have a ways to go, but these changes should greatly improve the number of head-scratchers served up
by the type checker.
These changes address the following radars:
rdar://problem/17618403
rdar://problem/17559042
rdar://problem/17007456
rdar://problem/17559042
rdar://problem/17590992
rdar://problem/17646988
rdar://problem/16979859
rdar://problem/16922560
rdar://problem/17144902
rdar://problem/16616948
rdar://problem/16756363
rdar://problem/16338509
Swift SVN r20927
