Because opaque types are currently limited so that they only have immediate
protocol constraints, and therefore don't interact with the outer generic
parameters at all, we can get away without adding same-type constraints for
the outer generic parameters to their substitutions in the generic signature
builder when setting up the environment for an opaque archetype. This
avoids the strict assertion that opaque types not appear in other decls'
interface types. rdar://problem/50509030
Adding where clauses would break this hack.
Check the availability of decls that declare an opaque return type to ensure they deploy to a
runtime that supports opaque types.
rdar://problem/50731151
Our ad-hoc mechanism for building the signature did not always produce requirements in the order
expected by the rest of the system; using the GSB should ensure we build a valid generic signature.
Fixes rdar://problem/50309983.
New diagnostic framework can already identify contextual failures
related to opaque return types, `RequirementFailure` just needs
to get adjusted to identify correct affected declaration and provide
tailored diagnostic.
Resolves: rdar://problem/49582531
This is necessary because:
```
func foo() -> some P
func foo() -> some P
```
theoretically defines two distinct return types, but there'd be no way to disambiguate them. Disallow overloading only by opaque return type.
This prevents opaque result types from propagating nontrivially into other declarations' types,
which may be confusing and create implementation complexities.
To represent the abstracted interface of an opaque type, we need a generic signature that refines
the outer context generic signature with an additional generic parameter representing the underlying
type and its exposed constraints. Opaque types also need to be keyed by their originating decl, so
that we can treat values of the same opaque type as the same. When we check a FuncDecl with an
opaque type specified as its return type, create an OpaqueTypeDecl and associate it with the
originating decl. (A representation for *types* derived from the opaque decl will come next.)
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.
* Make Self available to instance member functions (SE-0068?)
* Works for value types and static functions.
* Further experiments with TypeExpr
* Move Self processing off diagnostic path
* diagnostic instead of assertion fail
* TypeExpr of DynamicSelfType now working.
* Update tests for availability of Self
* Cast to Self fixed!
* Self not available as type in classes except for return type
* Could it be this simple?
* Nearly there
* Fix function decls using Self inside methods.
* Fix validation-test/compiler_crashers_2_fixed/0164-sr7989.swift
* Fix of ./validation-test/compiler_crashers_2_fixed/0179-rdar44963974.swift
* "Un-fix" validation-test/compiler_crashers_2_fixed/0164-sr7989.swift
* CHANGELOG entry
* Update CHANGELOG.md
Co-Authored-By: johnno1962 <github@johnholdsworth.com>
* Update CHANGELOG.md
When the compiler fails to find an overload with suitable parameter or return types, it often attaches a note listing the available overloads so that users can find the one they meant to use. The overloads are currently ordered in a way that depends on the order they were declared, so swift-evolve would sometimes cause tests involving these diagnostics to fail.
This change emits the list in a textually-sorted order instead. The names were already being sorted as they were inserted into a std::set, so this shouldn’t significantly slow down the diagnostic.
If generic parameter associated with missing conformance comes
from different context diagnose the problem as "referencing" a
specific declaration from affected type.
Instead of simply pointing out which type had conformance failures,
let's use affected declaration instead, which makes diagnostics much
richer e.g.
```
'List<[S], S.Id>' requires that 'S.Id' conform to 'Hashable'
```
versus
```
initializer 'init(_🆔)' requires that 'E' conform to 'Hashable' [with 'E' = 'S.Id']
```
Since latter message uses information about declaration, it can also
point to it in the source. That makes is much easier to understand when
problem is related to overloaded (function) declarations.
Validation of the input side of FunctionTypeRepr was previously being done in Sema because of expression folding. If we instead push the invariant that the input TypeRepr should always be a TupleTypeRepr into the AST a number of nice cleanups fall out:
- The SIL Parser no longer accepts Swift 2-style type declarations
- Parse is more cleanly able to reject invalid FunctionTypeReprs
- Clients of the AST can be assured the input type is always a TupleType so we can flush Swift 2 hacks
