As part of this change, we also extend the usage of RealVariable in more
places during DFA. Now mutable properties, property with custom getters,
delegated properties, etc are also treatd as a `RealVariable`. In
general this is needed in order to carry out smartcast computation in
order to report `SMARTCAST_IMPOSSIBLE`. It seems to also have side
effects that improves behavior of some test files.
As part of this change, we also extend the usage of RealVariable in more
places during DFA. Now mutable properties, property with custom getters,
delegated properties, etc are also treatd as a `RealVariable`. In
general this is needed in order to carry out smartcast computation in
order to report `SMARTCAST_IMPOSSIBLE`. It seems to also have side
effects that improves behavior of some test files.
This directive anyway does not make test run twice with OI, and with NI
It only once run the test with specific settings (// LANGUAGE)
and ignores irrelevant (OI or NI tags)
This new kind of expression encompasses the nullability of the original
expression after null check (or equivalent `is Nothing?` check).
Unlike FirExpressionWithSmartcast, this expression won't be materialized
during conversion to backend IR. Also, Nothing? is discarded when
computing the intersection of possible types from smartcast info.
In that way, Nothing? is not used during resolution, while such
smartcast info is stored in it (and the expression kind itself).
Added checker for FirEqualityOperatorCall. It's surfaced as one of the
following diagnostics depending on the PSI structure and types under
comparison:
* INCOMPATIBLE_TYPES(_WARNING)
* EQUALITY_NOT_APPLICABLE(_WARNING)
* INCOMPATIBLE_ENUM_COMPARISON_ERROR
Comparing with FE1.0, the current implementation is more conservative
and only highlights error if the types are known to follow certain
contracts with `equals` method. Otherwise, the checker reports warnings
instead.
However, the current checker is more strict in the following situations:
1. it now rejects incompatible enum types like `Enum<E1>` and
`Enum<E2>`, which was previously accepted
2. it now rejects incompatible class types like `Class<String>` and
`Class<Int>`, which was previously accepted
3. the check now takes smart cast into consideration, so
`if (x is String) x == 3` is now rejected
Ivan Kochurkin