If a generic parameter is not referred to from a function signature, it can never be inferred and thus such a function can never be invoked.
We now produce the following error:
generic parameter 'T' is not used in function signature
func f8<T> (x: Int) {}
This commit takes Jordan't comments on r28181 into account:
- it produces a shorter error message
- it does not change the compiler_crashers_fixed test and add a new expected error instead
Swift SVN r28194
If a generic parameter is not referred to from a function signature, it can never be inferred and thus such a function can never be invoked.
We now produce the following error:
There is no way to infer the generic parameter 'T' if it is not used in function signature
func f8<T> (x: Int) {}
^
Swift SVN r28181
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
You'll notice that we already had tests that made it appear that such declarations could work,
but they were only avoiding crashes because downstream errors were already marking the
enclosing functions as invalid. (If the errors were fixed, they would also crash the compiler.)
This addresses crash suite scenario 018. (rdar://problem/18299547)
Swift SVN r22109
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
introduce the generic type parameters (which are simply type aliases
for a to-be-determined archetype type) into scope for name
lookup. We can now parse something like
func f<T, U : Range>(x : T, y : U) { }
but there is no semantic analysis or even basic safety checking (yet).
Swift SVN r2197
