This commit handles subtle situation when K1 represents flexible type
arguments as just T..T?, but K2 does it as T&Any..T?.
This can provoke a type like Captured(*)&Any..Captured(*)?,
and before this commit we couldn't find recursion inside Captured(*)&Any.
This could lead to explosions inside type system and inference errors
#KT-60581 Fixed
See the comment at updateSubstitutedMemberIfReceiverContainsTypeVariable
It became necessary after delegate inference is rewritten, since before
that happened, stub types were being left there and FIR2IR handled
them accidentally properly because stub types are equal to anything.
But that wasn't really correct even there because stub types are not
intended to leak out of the FIR
^KT-61060
A new resolution diagnostic UnsuccessfulCallableReferenceAtom is
introduced that is used in EagerResolveOfCallableReferences.
No diagnostic is reported on unresolved calls with this diagnostic
because
#KT-59856
For CallKind.VariableAccess, the condition when to *skip* resolution of
objects was previously collector.isSuccess. This wasn't strict enough
because collector.isSuccess could be true when the best found candidate
has an applicability like RESOLVED_WITH_LOW_PRIORITY (e.g. from dynamic
scope or annotated with @LowPriorityInOverloadResolution). In these
cases, we do want to resolve objects. To fix this, the condition is
changed to collector.shouldStopResolve which is stricter.
#KT-57960 Fixed
The change is needed for the parallel resolution (^KT-55750), so we can resolve the declaration
under a lock that is specific to this declaration.
Previously, if LL FIR was resolving some FirClass, LL FIR resolved all its children too, and it had no control over what parts of the FIR tree were modified.
The same applied to the designation path, sometimes the classes on the designation path
might be unexpectedly (and without lock) modified.
This commit introduces LLFirResolveTarget, which specifies which exact declarations should be resolved during the lazy resolution of the declaration.
All elements outside the declarations specified for resolve in LLFirResolveTarget, should not be modified.
The logic of lazy transformers is the following:
- Go to target declaration collecting all scopes from the file and containing classes
- Resolve only declarations that are specified by the LLFirResolveTarget, performing the resolve under a separate lock for each declaration
^KT-56543
^KT-57619 Fixed
Namely, do not choose `Nothing?` result type when fixing a variable
that has other constraints besides the ones that came from
the relevant type parameter's upper bounds.
See more details in KT-55691.
In K1, the case from specialCallWithMaterializeAndExpectedType.kt
was working (inferred to String?) just because the branches
were analyzed independently with `String?` expected type.
This change became necessary after the previous commit when we united
inference subsystems for if/when branches (see motivation there).
NB: For K1, the behavior is left the same, but the code
was refactored a bit.
^KT-55691 Fixed
^KT-56448 Fixed
* `return` should only be added to the last statement if the return
type is not Unit
* If there is a `return` without an argument, then the expected return
type is Unit and the last expression is not a return argument (unless
it's an incomplete call, in which case it is inferred to return Unit;
this behavior is questionable, but inherited from K1)
* There should be a constraint on return arguments even if the expected
type is Unit, otherwise errors will be missed
* When the expected type is known, using the call completion results
writer is pointless (and probably subtly wrong).
^KT-54742 Fixed
Also remove incorrect subtype check checkers
Test unsafeVarianceInAliasedFunctionalType.kt started to fail because
of KT-54894. This bug existed before, changes from this commit just
unhided it (previously it was hidden because incorrect subtype check
in `isSubtypeForTypeMismatch` which is used by FirFunctionReturnTypeMismatchChecker
Before this commit, we added Enum.entries only in case when
LanguageFeature.EnumEntries was ON (with an exception in K1/Java case).
In this commit we add Enum.entries unconditionally, and in case
the language feature is OFF we filter them out during tower resolve.
That issue might be fixed via changing
TypeVariableMarker.shouldBeFlexible at ConeConstraintSystemUtilContext
but this and some other tricks have been added because of incorrect
handling of constraints where type variable has a flexible bound
^KT-51168 Fixed
Kirill Rakhman