It uses the same logic as an old back-end
(see SamType#createByValueParameter and genericSamProjectedOut.kt),
split into two parts:
1. When inserting SAM casts, use SamType#createByValueParamerer to get
the target SAM type.
2. When inserting implicit casts, cast SAM conversions as arguments of
methods of out-projected types to the original type of value parameter
instead of 'Nothing'.
Consider the following example:
Java:
public class J {
public static String foo() { return null; }
}
Kotlin:
fun check(fn: () -> Any) = fn()
fun test() = check { J.foo() }
When a lambda expression returns a value of platform type ('String!'),
corresponding lambda has platform type in its return type, which is
approximated to corresponding nullable type ('String?') in IR.
However, the lambda itself could occur in position with a functional
expected type ('() -> Any'). This implies an extra implicit cast on a
return value of lambda expression ('J.foo()'), although it conforms to
the return type of lambda.
When generating bodies for members implemented by delegation, invoke
corresponding delegate member, not an interface member. Otherwise we
might lose platform-specific nullability information in case of mixed
Kotlin-Java hierarchies, as in
implicitNotNullOnDelegatedImplementation.kt
May happen when a function in an `expect` class is aliased through an
`actual typealias`; the matching declaration is filtered out in
`ExpectedActualResolver.findActualForExpected` as it has no source.
This makes sense because this mode is the default in the production
compiler. Forgetting to enable it where necessary led to different
bizarre test failures, see for example changes around 3fee84b966 and
KT-34826
Preserve type substitution:
- when obtaining function type for SAM type;
- when generating SAM conversions for SAM adapter arguments;
- for "original" method corresponding to a SAM adapter.
annotationsViaActualTypeAliasFromBinary.kt is ignored because
ExpectActualRemover can't find actual for the expected constructor of
Anno now, because `ExpectedActualResolver.findActualForExpected`
incorrectly filters out actual declarations without any source file, and
Java classes loaded in the fast mode don't have any source files.
This will need to be fixed separately, probably by making
ExpectedActualResolver look for the actual class of an expected class
member first (with source file-based filtering), and then
unconditionally locating the corresponding member there
Introduce MetadataSource as a way to store the original descriptor for
any element (before any lowerings) and maintain it until the end of the
codegen where it's used in generating the metadata. Note that JVM
signatures written to the metadata are formed from the _resulting_
generated elements, not by mapping the original descriptors.
Some corner cases are not supported yet, namely properties declared in
companion objects, synthetic methods for property annotations,
JvmPackageName, etc.
#KT-29119 Fixed
The root problem is the fact that ConstantExpressionEvaluator returns
null for values such as infinity and NaN loaded from cls psi (see
IDEA-207252). This commit simply reverts a part of 8ab9226805 where we
started to compute default values more often than needed. In
LazyJavaClassMemberScope, we only need to check whether or not there
_is_ a default value, not compute its value.
#KT-29792 Fixed
IrDeclarationOrigin.FILE_CLASS is used in CallableReferenceLowering to
generate correct declaration owner.
Many reflection tests start to fail with this commit because they are
now treating callable references to top level declarations as Kotlin
symbols and fail because there's no JVM signature for them; this is
fixed in subsequent commits (previously, they worked because without
Kotlin metadata, these files were treated as Java classes)
Most of these tests used this directive as a way to opt in to a new
language feature, and most of those features are already stable for a
long time, so no opt-in is needed. Some other tests used the directive
to opt out from a language feature, replace those by the `LANGUAGE`
directive. One test used the directive to test behavior that actually
depended on the API version; use `API_VERSION` directive there instead.
See how we translate raw types to Kotlin model:
RawType(A) = A<ErasedUpperBound(T1), ...>
ErasedUpperBound(T : G<t>) = G<*> // UpperBound(T) is a type G<t> with arguments
ErasedUpperBound(T : A) = A // UpperBound(T) is a type A without arguments
ErasedUpperBound(T : F) = UpperBound(F) // UB(T) is another type parameter F
Stack overflow happens with the following classes:
class A<X extends B> // NB: raw type B in upper bound
class B<Y extends A> // NB: raw type A in upper bound
when calculating raw type for A, we start calculate ErasedUpperBound(Y),
thus starting calculating raw type for B => ErasedUpperBound(X) => RawType(A),
so we have SOE here.
The problem is that we calculating the arguments for these raw types eagerly,
while from the definition of ErasedUpperBound(Y) we only need a type constructor
of raw type B (and the number of parameters), we don't use its arguments.
The solution is to make arguments calculating for raw types lazy
#KT-16528 Fixed
