There was a diagnostic to catch these, but it wasn't triggered
reliably, and it sounds like users were already relying on this
feature working in the few cases where it did.
So instead, just map an archetype's superclass into context
when building the archetype.
Recursion is still not allowed and is diagnosed, for example
<T, U where T : C<U>, U : C<T>>.
Note that compiler_crashers_fixed/00022-no-stacktrace.swift no
longer produces a diagnostic in Sema, despite the fact that the
code is invalid. It does diagnose in IRGen when we map the
type into context. Diagnosing in Sema requires fixing the
declaration checker to correctly handle recursion through a
generic signature. Right now, if recursion is detected, we bail
out, but do not always diagnose. Alternatively, we could
prohibit unbound generic types from appearing in generic
signatures.
This is a more principled fix for rdar://problem/24590570.
In some completely insane cases, typechecking an EnumElementDecl
can recursively reference itself. Make sure to produce an error
and bail out when this happens.
Not all types are l-valuable, notably InoutType's. This seems like a
weird restriction to put in the type checker, but it is the cleanest
solution to this. The better solution would be to change how
inoutexpr/inouttype are represented completely... maybe someday.
Formerly we stopped type checking a PatternBindingDecl when it was marked
as invalid. This prevented semantic analysis from doing things like expanding
"stored" properties in protocols into computed properties with getters and setter,
causing downstream problems.
Stop doing this, and instead do a bit of work to silence the downstream errors in
a more narrow way.
The problem was that an associated type was always resolved with the nearest protocol `Self` as a reference, but in the case of nested protocols the associated type might be from the enclosing protocol leading to a crash.
We now enumerate in a bottom-up way through the contexts until we have found the correct protocol which provides us with the `Self` reference to resolve the associated type.
closures which have already been transformed into void conversion closures.
This fixes 28213-swift-expr-walk.swift/28187-llvm-foldingset-swift-constraints-constraintlocator.swift
A decl’s full GenericSignature is set during validateGenericTypeSignature().
Then during ConstraintSystem::openTypes(), in ReplaceDependentTypes, the GenericArgs list is built from the generic signature (via getGenericParamTypes()) and passed into a new BoundGenericType.
In BoundGenericType::getSubstitutions(), the GenericArgs are assumed to match getGenericParamsOfContext()->getParams().
However, in reality, the GenericArgs include all levels of generic args, whereas getGenericParamsOfContext() are the params of the innermost context only, so the params array is accessed past its end.
This commit changes NominalTypeDecl::getGenericParamTypes() to return the innermost params, in order to match the output of BoundGenericType::getGenericArgs(). For clarity and to hopefully prevent future confusion, we also rename getGenericParamTypes() to getInnermostGenericParamTypes().
