FIR: Simplify API for ensureResolved

Additional `as` casts look redundant, but it's a design issue (see KT-41421)

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/FirPhaseManager.kt

@@ -7,16 +7,14 @@ package org.jetbrains.kotlin.fir.resolve.transformers
 
 import org.jetbrains.kotlin.fir.FirSession
 import org.jetbrains.kotlin.fir.FirSessionComponent
-import org.jetbrains.kotlin.fir.FirSymbolOwner
-import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 
 abstract class FirPhaseManager : FirSessionComponent {
-    abstract fun <D> ensureResolved(
-        symbol: AbstractFirBasedSymbol<D>,
+    abstract fun ensureResolved(
+        symbol: AbstractFirBasedSymbol<*>,
         requiredPhase: FirResolvePhase = FirResolvePhase.DECLARATIONS
-    ) where D : FirDeclaration, D : FirSymbolOwner<D>
+    )
 }
 
 internal val FirSession.phaseManager: FirPhaseManager? by FirSession.nullableSessionComponentAccessor()

compiler/fir/resolve/src/org/jetbrains/kotlin/fir/resolve/transformers/PhaseUtils.kt

@@ -6,19 +6,19 @@
 package org.jetbrains.kotlin.fir.resolve.transformers
 
 import org.jetbrains.kotlin.fir.FirSession
-import org.jetbrains.kotlin.fir.FirSymbolOwner
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirFunction
 import org.jetbrains.kotlin.fir.declarations.FirProperty
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.symbols.AbstractFirBasedSymbol
 
-fun <D> AbstractFirBasedSymbol<D>.ensureResolved(
+fun AbstractFirBasedSymbol<*>.ensureResolved(
     requiredPhase: FirResolvePhase,
     // TODO: Currently, the parameter is unused but it's needed to guarantee that all call-sites are able to supply use-site session
     // TODO: Decide which one session should be used and probably get rid of the parameter if use-site session is not needed
     useSiteSession: FirSession,
-) where D : FirDeclaration, D : FirSymbolOwner<D> {
+) {
+    val fir = fir as FirDeclaration
     val availablePhase = fir.resolvePhase
     if (availablePhase >= requiredPhase) return
     val resolver = fir.session.phaseManager
@@ -27,9 +27,9 @@ fun <D> AbstractFirBasedSymbol<D>.ensureResolved(
     resolver.ensureResolved(this, requiredPhase)
 }
 
-fun <D> AbstractFirBasedSymbol<D>.ensureResolvedForCalls(
+fun AbstractFirBasedSymbol<*>.ensureResolvedForCalls(
     useSiteSession: FirSession,
-) where D : FirDeclaration, D : FirSymbolOwner<D> {
+) {
     val requiredPhase = when (this.fir) {
         is FirFunction<*>, is FirProperty -> FirResolvePhase.CONTRACTS
         else -> FirResolvePhase.STATUS

idea/idea-frontend-fir/idea-fir-low-level-api/src/org/jetbrains/kotlin/idea/fir/low/level/api/IdeFirPhaseManager.kt

@@ -5,7 +5,6 @@
 
 package org.jetbrains.kotlin.idea.fir.low.level.api
 
-import org.jetbrains.kotlin.fir.FirSymbolOwner
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirResolvePhase
 import org.jetbrains.kotlin.fir.render
@@ -19,15 +18,15 @@ internal class IdeFirPhaseManager(
     private val lazyDeclarationResolver: FirLazyDeclarationResolver,
     private val cache: ModuleFileCache
 ) : FirPhaseManager() {
-    override fun <D> ensureResolved(
-        symbol: AbstractFirBasedSymbol<D>,
+    override fun ensureResolved(
+        symbol: AbstractFirBasedSymbol<*>,
         requiredPhase: FirResolvePhase
-    ) where D : FirDeclaration, D : FirSymbolOwner<D> {
-        val result = symbol.fir
+    ) {
+        val result = symbol.fir as FirDeclaration
         val availablePhase = result.resolvePhase
         if (availablePhase >= requiredPhase) return
         // NB: we should use session from symbol here, not transformer session (important for IDE)
-        val provider = symbol.fir.session.firProvider
+        val provider = result.session.firProvider
 
         require(provider.isPhasedFirAllowed) {
             "Incorrect resolvePhase: actual: $availablePhase, expected: $requiredPhase\n For: ${symbol.fir.render()}"