[Commonizer] Use 'index:Int' instead of Name for addressing type parameters

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/builderUtils.kt

@@ -27,7 +27,6 @@ internal fun List<CirTypeParameter>.buildDescriptorsAndTypeParameterResolver(
     val ownTypeParameters = mutableListOf<TypeParameterDescriptor>()
 
     val typeParameterResolver = TypeParameterResolverImpl(
-        storageManager = targetComponents.storageManager,
         ownTypeParameters = ownTypeParameters,
         parent = parentTypeParameterResolver
     )
@@ -120,9 +119,8 @@ internal fun CirSimpleType.buildType(
             }
         }
         is CirClassifierId.TypeParameter -> {
-            val name = classifierId.name
+            typeParameterResolver.resolve(classifierId.index)
-            typeParameterResolver.resolve(name)
+                ?: error("Type parameter $classifierId not found in ${typeParameterResolver::class.java}, $typeParameterResolver for ${targetComponents.target}")
-                ?: error("Type parameter $name not found in ${typeParameterResolver::class.java}, $typeParameterResolver for ${targetComponents.target}")
         }
     }
 

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/builder/context.kt

@@ -184,27 +184,36 @@ fun CirRootNode.createGlobalBuilderComponents(
 }
 
 interface TypeParameterResolver {
-    fun resolve(name: Name): TypeParameterDescriptor?
+    val parametersCount: Int
+    fun resolve(index: Int): TypeParameterDescriptor?
 
     companion object {
         val EMPTY = object : TypeParameterResolver {
-            override fun resolve(name: Name): TypeParameterDescriptor? = null
+            override val parametersCount get() = 0
+            override fun resolve(index: Int): TypeParameterDescriptor? = null
         }
     }
 }
 
 class TypeParameterResolverImpl(
-    storageManager: StorageManager,
+    private val ownTypeParameters: List<TypeParameterDescriptor>,
-    ownTypeParameters: List<TypeParameterDescriptor>,
     private val parent: TypeParameterResolver = TypeParameterResolver.EMPTY
 ) : TypeParameterResolver {
+    override val parametersCount: Int
+        get() = ownTypeParameters.size + parent.parametersCount
 
-    private val ownTypeParameters = storageManager.createLazyValue {
+    @Suppress("ConvertTwoComparisonsToRangeCheck")
-        // memoize the first occurrence of descriptor with the same Name
+    override fun resolve(index: Int): TypeParameterDescriptor? {
-        ownTypeParameters.groupingBy { it.name }.reduce { _, accumulator, _ -> accumulator }
+        val parentParametersCount = parent.parametersCount
+        if (index >= 0 && index < parentParametersCount)
+            return parent.resolve(index)
+
+        val localIndex = index - parentParametersCount
+        if (localIndex < ownTypeParameters.size)
+            return ownTypeParameters[localIndex]
+
+        error("Illegal type parameter index: $index. Should be between 0 and ${parametersCount - 1}")
     }
-
-    override fun resolve(name: Name) = ownTypeParameters()[name] ?: parent.resolve(name)
 }
 
 fun DeclarationDescriptor.getTypeParameterResolver(): TypeParameterResolver =

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/CirClassifierId.kt

@@ -6,7 +6,6 @@
 package org.jetbrains.kotlin.descriptors.commonizer.cir
 
 import org.jetbrains.kotlin.name.ClassId
-import org.jetbrains.kotlin.name.Name
 
 sealed class CirClassifierId {
     interface ClassOrTypeAlias {
@@ -15,5 +14,5 @@ sealed class CirClassifierId {
 
     data class Class(override val classId: ClassId) : ClassOrTypeAlias, CirClassifierId()
     data class TypeAlias(override val classId: ClassId) : ClassOrTypeAlias, CirClassifierId()
-    data class TypeParameter(val name: Name) : CirClassifierId()
+    data class TypeParameter(val index: Int) : CirClassifierId()
 }

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/cir/factory/CirClassifierIdFactory.kt

@@ -1,15 +1,10 @@
 package org.jetbrains.kotlin.descriptors.commonizer.cir.factory
 
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
+import org.jetbrains.kotlin.descriptors.*
-import org.jetbrains.kotlin.descriptors.ClassifierDescriptor
-import org.jetbrains.kotlin.descriptors.TypeAliasDescriptor
-import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.descriptors.commonizer.cir.CirClassifierId
 import org.jetbrains.kotlin.descriptors.commonizer.utils.Interner
-import org.jetbrains.kotlin.descriptors.commonizer.utils.intern
 import org.jetbrains.kotlin.descriptors.commonizer.utils.internedClassId
 import org.jetbrains.kotlin.name.ClassId
-import org.jetbrains.kotlin.name.Name
 
 @Suppress("MemberVisibilityCanBePrivate")
 object CirClassifierIdFactory {
@@ -19,12 +14,25 @@ object CirClassifierIdFactory {
         return when (source) {
             is ClassDescriptor -> createForClass(source.internedClassId)
             is TypeAliasDescriptor -> createForTypeAlias(source.internedClassId)
-            is TypeParameterDescriptor -> createForTypeParameter(source.name.intern())
+            is TypeParameterDescriptor -> createForTypeParameter(source.typeParameterIndex)
             else -> error("Unexpected classifier descriptor type: ${source::class.java}, $this")
         }
     }
 
     fun createForClass(classId: ClassId): CirClassifierId = interner.intern(CirClassifierId.Class(classId))
     fun createForTypeAlias(classId: ClassId): CirClassifierId = interner.intern(CirClassifierId.TypeAlias(classId))
-    fun createForTypeParameter(name: Name): CirClassifierId = interner.intern(CirClassifierId.TypeParameter(name))
+    fun createForTypeParameter(index: Int): CirClassifierId = interner.intern(CirClassifierId.TypeParameter(index))
 }
+
+private inline val TypeParameterDescriptor.typeParameterIndex: Int
+    get() {
+        var index = index
+        var parent = containingDeclaration
+
+        while ((parent as? ClassifierDescriptorWithTypeParameters)?.isInner != false) {
+            parent = parent.containingDeclaration as? ClassifierDescriptorWithTypeParameters ?: break
+            index += parent.declaredTypeParameters.size
+        }
+
+        return index
+    }

native/commonizer/src/org/jetbrains/kotlin/descriptors/commonizer/core/TypeCommonizer.kt

@@ -52,7 +52,7 @@ private fun areSimpleTypesEqual(cache: CirClassifiersCache, a: CirSimpleType, b:
         }
 
         if (aId is CirClassifierId.TypeParameter) {
-            if (bId !is CirClassifierId.TypeParameter || aId.name != bId.name) return false
+            if (bId !is CirClassifierId.TypeParameter || aId.index != bId.index) return false
         }
     }