Even with an opaque abstraction pattern, we must explode a
parameter list containing __shared and __owned elements.
Otherwise, we produce invalid lowered SIL types.
Note that this is already an issue, because the stdlib has a
handful of declarations using __owned.
The verifier asserts that declarations whose interface type contains an error
are invalid, so let's just mark them invalid when we set the interface type,
instead of needlessly duplicating this logic all over the declaration checker.
ClassDecl::getSuperclass() produces a complete interface type describing the
superclass of a class, including any generic arguments (for a generic type).
Most callers only need the referenced ClassDecl, which is (now) cheaper
to compute: switch those callers over to ClassDecl::getSuperclassDecl().
Fixes an existing test for SR-5993.
Introduce three new requests for name lookup operations that avoid performing
type checking/semantic analysis. They work using syntactic information
(e.g., TypeReprs) and AST-level name lookup operations that will (eventually)
avoid and calls back into type checking. The new requests are:
* Retrieve the superclass declaration of a protocol or class declaration. Use
this request for ClassDecl::getSuperclassDecl() and
ProtocolDecl::getSuperclassDecl().
* Retrieve the types “directly referenced” by a particular location in
an inheritance clause. This query is based on looking at the TypeReprs
and performing fairly-minimal lookup, so it does not involve any Type
computations.
* Retrieve the types “directly referenced” by the underlying type of
a typealias. This query allows us to desugar a typealias without forming
a type.
Along with these is a core operation to transform a set of TypeDecl*s
into a set of NominalTypeDecl*s, looking through typealiases, and
without involving Type at all. The superclass-decl request does this
to find a ClassDecl; other requests will eventually do this to (e.g.)
find all of the protocols mentioned in an inheritance clause.
For now, the accessors have been underscored as `_read` and `_modify`.
I'll prepare an evolution proposal for this feature which should allow
us to remove the underscores or, y'know, rename them to `purple` and
`lettuce`.
`_read` accessors do not make any effort yet to avoid copying the
value being yielded. I'll work on it in follow-up patches.
Opaque accesses to properties and subscripts defined with `_modify`
accessors will use an inefficient `materializeForSet` pattern that
materializes the value to a temporary instead of accessing it in-place.
That will be fixed by migrating to `modify` over `materializeForSet`,
which is next up after the `read` optimizations.
SIL ownership verification doesn't pass yet for the test cases here
because of a general fault in SILGen where borrows can outlive their
borrowed value due to being cleaned up on the general cleanup stack
when the borrowed value is cleaned up on the formal-access stack.
Michael, Andy, and I discussed various ways to fix this, but it seems
clear to me that it's not in any way specific to coroutine accesses.
rdar://35399664
Introduce a new request kind to capture the computation of the set of
overridden declarations of a given declaration, eliminating the
stateful “setOverriddenDecls()” calls from the type checker.
It's possible that the conforming type is equal to the generic
conformance type, but some of the substitutions replace an
abstract conformance with a concrete one.
In this case we cannot collapse away the specialized conformance,
because we lose information that way.
Fixes <rdar://problem/40164371>.
The constructor can modify the SpecializedConformances FoldingSet so that the
insertPos is no longer valid. It calls computeConditionalRequirements which
calls Type::subst which recursively can call getSpecializedConformance again.
This bug manifest itself either as memory error with libgmalloc or as
spurious errors later on.
rdar://42082352
More groundwork for protocols with superclass constraints.
In several places we need to distinguish between existential
types that have a superclass term (MyClass & Proto) and
existential types containing a protocol with a superclass
constraint.
This is similar to how I can write 'AnyObject & Proto', or
write 'Proto1 & Proto2' where Proto1 has an ': AnyObject'
in its inheritance clause.
Note that some of the usages will be revisited later as
I do more refactoring and testing. This is just a first pass.
Several kinds of declarations can override other declarations, but the
computation and storage for these “overridden” declarations was scattered in
at least 3 different places, with different resolution paths. Pull them
all together into two bits of LazySemanticInfo in ValueDecl (“have we computed
overrides?” and “are there any overrides?”), with a side table for the
actual list of overrides.
One side effect here is that the AST can now represent multiple overridden
declarations, although only associated type declarations track this
information.
Start using LazyResolver::resolveOverriddenDecl() more consistently, unifying
it with the separate path we had for associated type overrides. All of this
is staging for a move to the request-evaluator for overridden declaration
computation.
As a debugging aid, introduce a new frontend flag `-debug-cycles` that
will emit a debug dump whenever the request-evaluator encounters a cyclic
dependency, while otherwise allowing compilation to continue.
The type checker has *lots* cycles, and producing diagnostics for them
at this point in the development of the request-evaluator is not
productive because it breaks currently-working code. Disable cycle
diagnostics for now when using the request-evaluator in the type
checker. We'll enable it later as things improve, or as a separate
logging mode in the interim.
Wire up the request-evaluator with an instance in ASTContext, and
introduce two request kinds: one to retrieve the superclass of a class
declaration, and one to compute the type of an entry in the
inheritance clause.
Teach ClassDecl::getSuperclass() to go through the request-evaluator,
centralizing the logic to compute and extract the superclass
type.
Fixes the crasher from rdar://problem/26498438.
Introduce some metaprogramming of accessors and generally prepare
for storing less-structured accessor lists.
NFC except for a change to the serialization format.
- De-templatize the intrinsic candidate search functions.
- Allow callback predicates access to the candidate's function type so they can evalute its parameters/return value themselves.
SubstitutionMaps are now just a trivial pointer-sized value, so
pass them by value instead.
I did have to move a couple of functors from Type.h to SubstitutionMap.h
to resolve some issues with forward declarations.
That is, if there's a problem with a witness, and the witness comes
from a different extension from the conformance (or the original type,
when the conformance is on an extension), put the main diagnostic on
the conformance, with a note on the witness. This involves some
shuffling and rephrasing of existing diagnostics too.
There's a few reasons for this change:
- More context. It may not be obvious why a declaration in file
A.swift needs to be marked 'public' if you can't see the conformance
in B.swift.
- Better locations for imported declarations. If you're checking a
conformance in a source file but the witness came from an imported
module, it's better to put the diagnostic on the part you have
control over. (This is especially true in Xcode, which can't display
diagnostics on imported declarations in the source editor.)
- Plays better with batch mode. Without this change, you can have
diagnostics being reported in file A.swift that are tied to a
conformance declared in file B.swift. Of course the contents of
A.swift also affect the diagnostic, but compiling A.swift on its
own wouldn't produce the diagnostic, and so putting it there is
problematic.
The change does in some cases make for a worse user experience,
though; if you just want to apply the changes and move on, the main
diagnostic isn't in the "right place". It's the note that has the info
and possible fix-it. It's also a slightly more complicated
implementation.
When building a substitution map, the client is only responsible for filling
in the replacement types for canonical generic parameters; the others
(e.g., those for generic parameters for which there is a same-type
constraint) can be filled in lazily. Profiling them leads to incorrect
uniquing of SubstitutionMap.
Fixes the rest of rdar://problem/39949332.
Now that SubstitutionMap is used in so many places, reduce it's header
dependencies by moving SubstitutionMap::Storage into its own separate
implementation header. Use forward declarations of other entities
(GenericSignature, Substitution) instead.
Good for build times and general sanity.
This can't arise from a clean build, but it can happen if you have
products lingering in a search path and then either rebuild one of
the modules in the cycle, or change the search paths.
The way this is implemented is for each module to track whether its
imports have all been resolved. If, when loading a module, one of its
dependencies hasn't resolved all of its imports yet, then we know
there's a cycle.
This doesn't produce the best diagnostics, but it's hard to get into
this state in the first place, so that's probably okay.
https://bugs.swift.org/browse/SR-7483
