This fixes <rdar://problem/20494437> SILGen crash handling default arguments
again, and includes a fix for MiscDiagnostics to look through the generated
TupleShuffleExprs in @noescape processing (which tripped up XCTest).
This fixes <rdar://problem/16860940> QoI: Strict keyword arguments loses type sugar in calls
where we'd lose some type sugar.
This fixes sanity in the ASTs: ScalarToTupleExpr now always has consistent
types between its argument and result, so we can turn on AST Verification of it.
Swift SVN r27827
The rule changes are as follows:
* All functions (introduced with the 'func' keyword) have argument
labels for arguments beyond the first, by default. Methods are no
longer special in this regard.
* The presence of a default argument no longer implies an argument
label.
The actual changes to the parser and printer are fairly simple; the
rest of the noise is updating the standard library, overlays, tests,
etc.
With the standard library, this change is intended to be API neutral:
I've added/removed #'s and _'s as appropriate to keep the user
interface the same. If we want to separately consider using argument
labels for more free functions now that the defaults in the language
have shifted, we can tackle that separately.
Fixes rdar://problem/17218256.
Swift SVN r27704
Inference of type witnesses for associated types was previously
implemented as part of value witness matching in the constraint
solver. This led to a number of serious problems, including:
- Recursion problems with the solver hunting for a type witness,
which triggers more attemts to match value witnesses...
- Arbitrarily crummy attempts to break the recursion causing
type-check failures in fun places.
- Ordering dependencies abound: different results depending on which
value witnesses were satisfied first, failures because of the order
in which we attempted to infer type witnesses, etc.
This new implementation of type witness inference uses a separate pass
that occurs whenever we're looking for any type witness, and solves
all of the type witnesses within a given conformance
simultaneously. We still look at potential value witnesses to infer
type witnesses, but we match them structurally, without invoking the
constraint solver.
There are a few caveats to this implementation:
* We're not currently able to infer type witnesses from value
witnesses that are global operators, so some tricks involving global
operators (*cough* ~> *cough*) might require some manually-specified
type witnesses. Note that the standard library doesn't include any
such cases.
* Yes, it's another kind of solver. At simple one, fortunately.
On the other hand, this implementation should be a big step forward:
* It's far more predictable, order-invariant, and non-recursive.
* The diagnostics for failures to infer type witnesses have
improved.
Fixes rdar://problem/20598513.
Swift SVN r27616
- Situations where the type of a return statement's result expression doesn't line up with the function's type annotation.
- Situations where the type of an initializer expression doesn't line up with its declaration's type pattern.
- Situations where we assume a conversion to a built-in protocol must take place, such as in if-statement conditionals.
(Addresses rdar://problem/19224776, rdar://problem/19422107, rdar://problem/19422156, rdar://problem/19547806 and lots of other dupes.)
Swift SVN r24853
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
This change includes a number of simplifications that allow us to
eliminate the type checker hack that specifically tries
AssertString. Doing so provides a 25% speedup in the
test/stdlib/ArrayNew.swift test (which is type-checker bound).
The specific simplifications here:
- User-level
assert/precondition/preconditionalFailure/assertionFailer/fatalError
always take an autoclosure producing a String, eliminating the need
for the StaticString/AssertString dance.
- Standard-library internal _precondition/_sanityCheck/etc. always
take a StaticString. When we want to improve the diagnostics in the
standard library, we can provide a separate overload or
differently-named function.
- Remove AssertString, AssertStringType, StaticStringType, which are
no longer used or needed
- Remove the AssertString hack from the compiler
- Remove the "BooleanType" overloads of these functions, because
their usefuless left when we stopped making optional types conform
to BooleanType (sorry, should have been a separate patch).
Swift SVN r22139
t2.swift:3:1: error: argument for generic parameter 'U' could not be
inferred
f(i)
^
t2.swift:2:6: note: in call to function 'f'
func f<T, U>(t: T) -> U? { return nil }
^
Our lack of decent locator information means that we don't get notes
in all of the cases we want them. I'll look at that separately.
Swift SVN r21921
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
It seems not-great that the same candidate can get into the overload set for a DeclRefExpr
multiple times, but if it does, don't expose this to the user.
Swift SVN r20315
modifiers and with the func implementations of the operators. This resolves the rest of:
<rdar://problem/17527000> change operator declarations from "operator prefix" to "prefix operator" & make operator a keyword
Swift SVN r19931
eliminating the @'s from them when used on func's. This is progress towards
<rdar://problem/17527000> change operator declarations from "operator prefix" to "prefix operator" & make operator a keyword
This also consolidates rejection of custom operator definitions into one
place and makes it consistent, and adds postfix "?" to the list of rejected
operators.
This also changes the demangler to demangle weak/inout/postfix and related things
without the @.
Swift SVN r19929
Mechanically add "Type" to the end of any protocol names that don't end
in "Type," "ible," or "able." Also, drop "Type" from the end of any
associated type names, except for those of the *LiteralConvertible
protocols.
There are obvious improvements to make in some of these names, which can
be handled with separate commits.
Fixes <rdar://problem/17165920> Protocols `Integer` etc should get
uglier names.
Swift SVN r19883
JoeP helped tweak things to ensure that pointer conversions are still
considered, but we no longer need the disjunction on InOutExprs to accommodate
user-defined inout conversions.
This causes some regressions in error reporting:
<rdar://problem/17489983> inout type mismatches complain about '@lvalue inout T'
<rdar://problem/17489894> inout not rejected as operand to assignment operator
Swift SVN r19306
One difficulty in generating reasonable diagnostic data for type check failures has been the fact that many constraints had been synthesized without regard for where they were rooted in the program source. The result of this was that even though we would store failure information for specific constraints, we wouldn't emit it for lack of a source location. By making location data a non-optional component of constraints, we can begin diagnosing type check errors closer to their point of failure.
Swift SVN r18751
coercion. Overload resolution uses this argument deduction when
dealing with generic functions, to determine when we can invoke a
generic function. When a generic function is selected, we create a
SpecializeExpr wrapping the DeclRefExpr to the generic function.
This is sufficient to type-check calls to simple things like a call to
func identity<T>(x : T) -> T { return x }
with a value of known type. However, it's missing far too many pieces
to enumerate.
Swift SVN r2230
