[FIR] Introduce valueClassRepresentation to FIR

#KT-1179
2022-03-14 16:33:05 +03:00
parent 28bf83ceac
commit b6f2513dd2
16 changed files with 131 additions and 33 deletions
@@ -0,0 +1,71 @@
+/*
+ * Copyright 2010-2021 JetBrains s.r.o. and Kotlin Programming Language contributors.
+ * Use of this source code is governed by the Apache 2.0 license that can be found in the license/LICENSE.txt file.
+ */
+
+package org.jetbrains.kotlin.fir.declarations
+
+import org.jetbrains.kotlin.descriptors.InlineClassRepresentation
+import org.jetbrains.kotlin.descriptors.ValueClassRepresentation
+import org.jetbrains.kotlin.descriptors.createValueClassRepresentation
+import org.jetbrains.kotlin.fir.FirSession
+import org.jetbrains.kotlin.fir.declarations.utils.isInline
+import org.jetbrains.kotlin.fir.resolve.fullyExpandedType
+import org.jetbrains.kotlin.fir.resolve.substitution.createTypeSubstitutorByTypeConstructor
+import org.jetbrains.kotlin.fir.resolve.toSymbol
+import org.jetbrains.kotlin.fir.symbols.ensureResolved
+import org.jetbrains.kotlin.fir.symbols.impl.FirRegularClassSymbol
+import org.jetbrains.kotlin.fir.types.*
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.types.model.typeConstructor
+
+internal fun ConeKotlinType.substitutedUnderlyingTypeForInlineClass(session: FirSession, context: ConeTypeContext): ConeKotlinType? {
+    val unsubstitutedType = unsubstitutedUnderlyingTypeForInlineClass(session) ?: return null
+    val substitutor = createTypeSubstitutorByTypeConstructor(
+        mapOf(this.typeConstructor(context) to this), context, approximateIntegerLiterals = true
+    )
+    return substitutor.substituteOrNull(unsubstitutedType)
+}
+
+internal fun ConeKotlinType.unsubstitutedUnderlyingTypeForInlineClass(session: FirSession): ConeKotlinType? {
+    val symbol = (this.fullyExpandedType(session) as? ConeLookupTagBasedType)
+        ?.lookupTag
+        ?.toSymbol(session) as? FirRegularClassSymbol
+        ?: return null
+    symbol.ensureResolved(FirResolvePhase.STATUS)
+    return symbol.fir.inlineClassRepresentation?.underlyingType
+}
+
+fun computeValueClassRepresentation(klass: FirRegularClass, session: FirSession): ValueClassRepresentation<ConeSimpleKotlinType>? {
+    val parameters = klass.getValueClassUnderlyingParameters(session)?.takeIf { it.isNotEmpty() } ?: return null
+    val fields = parameters.map { it.name to it.returnTypeRef.coneType as ConeSimpleKotlinType }
+    fields.singleOrNull()?.let { (name, type) ->
+        if (isRecursiveSingleFieldValueClass(type, session, mutableSetOf(type))) { // escape stack overflow
+            return InlineClassRepresentation(name, type)
+        }
+    }
+    return createValueClassRepresentation(session.typeContext, fields)
+}
+
+private fun FirRegularClass.getValueClassUnderlyingParameters(session: FirSession): List<FirValueParameter>? =
+    if (isInline) primaryConstructorIfAny(session)?.fir?.valueParameters else null
+
+private fun isRecursiveSingleFieldValueClass(
+    type: ConeSimpleKotlinType,
+    session: FirSession,
+    visited: MutableSet<ConeSimpleKotlinType>
+): Boolean {
+    val nextType = type.valueClassRepresentationTypeMarkersList(session)?.singleOrNull()?.second ?: return false
+    return !visited.add(nextType) || isRecursiveSingleFieldValueClass(nextType, session, visited)
+}
+
+private fun ConeSimpleKotlinType.valueClassRepresentationTypeMarkersList(session: FirSession): List<Pair<Name, ConeSimpleKotlinType>>? {
+    val symbol = this.toSymbol(session) as? FirRegularClassSymbol ?: return null
+    if (!symbol.fir.isInline) return null
+    symbol.fir.valueClassRepresentation?.let { return it.underlyingPropertyNamesToTypes }
+    symbol.ensureResolved(FirResolvePhase.TYPES)
+    val constructorSymbol = symbol.fir.primaryConstructorIfAny(session) ?: return null
+    return constructorSymbol.valueParameterSymbols
+        .onEach { it.ensureResolved(FirResolvePhase.TYPES) }
+        .map { it.name to it.resolvedReturnType as ConeSimpleKotlinType }
+}