- In LL FIR, we have increasingly formalized symbol name caches as
palpable objects. The main reasons for this formalization were the
need to share implementations of caching between different (LL FIR)
symbol providers, the need to build composite name caches from
individual name caches, and the introduction of resolve extensions
which may provide additional declarations and thus complicate the name
set construction for Kotlin symbol providers in LL FIR.
- `LLFirSymbolProviderNameCache` also shared a lot of similarities with
cache handling in FIR providers like
`FirCachingCompositeSymbolProvider` and
`AbstractFirDeserializedSymbolProvider`.
- This commit introduces a `FirSymbolNamesProvider` as a component of
`FirSymbolProvider`. This symbol names provider's task is to provide
the sets of names which `FirSymbolProvider` previously provided. It
also allows sharing implementations of `mayHaveTopLevel*` once and for
all, which is an improvement over the previously scattered
implementations (the same ideas replicated many times throughout
different symbol providers).
- `FirSymbolNamesProvider` by design doesn't cache, as many symbol
providers may not need such a cache. `FirCachedSymbolNamesProvider`
can be used to cache symbol names if needed. The symbol name provider
architecture also makes it easier to switch between caching and
non-caching, without the need to reimplement caches every time.
- Synthetic function types complicate the picture, but this complication
is now exposed with the rest of the API, instead of being hidden in a
few implementations here and there. This allows symbol providers to
more explicitly state whether they can provide generated function
types, which is an advantage for the correctness of composite symbol
providers.
Some specific notes:
- In `FirSyntheticFunctionInterfaceProviderBase`, the class ID check has
been replaced with a full `mayHaveTopLevelClassifier` check so that
the cache doesn't get filled with `null` entries.
- `LLFirKotlinSymbolProviderNameCache` is turned into a non-caching
`LLFirKotlinSymbolNamesProvider` so that this symbol names provider
and those of resolve extensions can be composed into one caching
symbol provider in `LLFirProviderHelper` without creating layers of
caches. If the Kotlin symbol names provider was caching out of the
box, `LLFirProviderHelper.symbolNameCache` would cache the
names (1) in the combined symbol names cache and (2) in the Kotlin
symbol names cache.
- A caching Kotlin symbol names cache can still be created easily with
the `LLFirKotlinSymbolNamesProvider.cached` constructor function.
Marco Pennekamp
accc9b0eb3