Compared to FE1.0, instead of using UNRESOLVED_REFERENCE, a new
UNRESOLVED_IMPORT diagnostic is introduced. This is so that we can use a
different positioning strategy to highlight the last part of the import
if the entire import is passed.
Also, this change fixed some incorrectly rejected imports in FIR. Such
cases are covered the newly added test file staticFunAndPropertyImport.kt
This is needed for two reasons:
1. Before this change companion object appeared in FirRegularClass
twice: in declarations list and in companionObject field. This may
trigger twice transform of it
2. It's very hard to implement generation of companion object by plugins
because if it is part of the tree then generated declaration must be
registered in FirProvider, which is inconsistent with other generated
declarations. Replacing FIR with symbol and removing custom logic of
visiting/transforming companion FIR allows us to just replace companionSymbol
in FirClass if plugin wants to generate it without any additional work
Those modules are:
- :compiler:fir:providers, which contains Fir and Symbol providers,
scopes, and different utilities used by them
- :compiler:fir:semantics, which contains different abstractions and
entities which are used in resolution and in checkers
- :compiler:fir:resolve, which contains all stuff related to resolution
and inference
There are two pros of this change:
1. It may increase gradle build, because it allows to compile :fir:resolve
and :fir:checkers modules in parallel
2. Logic of working FIR (scopes, providers, DFA logic system, etc) is
now separated from logic of resolution phases, so for example checkers,
which are depend on scopes physically will not be able to run resolve
in any way
Ivan Kochurkin