IR: make descriptor optional in IrSymbol

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrBasedDescriptors.kt

@@ -14,9 +14,7 @@ import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.*
-import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
-import org.jetbrains.kotlin.ir.symbols.IrClassifierSymbol
-import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
+import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.name.Name
@@ -34,7 +32,8 @@ import org.jetbrains.kotlin.types.*
 
 /* Descriptors that serve purely as a view into IR structures.
    Created each time at the borderline between IR-based and descriptor-based code (such as inliner).
-   Compared to WrappedDescriptors, no method calls ever return true descriptors.
+   Compared to WrappedDescriptors, no method calls ever return true descriptors, except when
+   unbound symbols are encountered (see `Ir...Symbol.toIrBasedDescriptorIfPossible()`).
  */
 
 abstract class IrBasedDeclarationDescriptor<T : IrDeclaration>(val owner: T) : DeclarationDescriptor {
@@ -108,6 +107,7 @@ fun IrDeclaration.toIrBasedDescriptor(): DeclarationDescriptor = when (this) {
     is IrLocalDelegatedProperty -> toIrBasedDescriptor()
     is IrFunction -> toIrBasedDescriptor()
     is IrClass -> toIrBasedDescriptor()
+    is IrAnonymousInitializer -> parentAsClass.toIrBasedDescriptor()
     is IrEnumEntry -> toIrBasedDescriptor()
     is IrProperty -> toIrBasedDescriptor()
     is IrField -> toIrBasedDescriptor()
@@ -1060,9 +1060,9 @@ private fun makeKotlinType(
     hasQuestionMark: Boolean
 ): SimpleType =
     when (classifier) {
-        is IrTypeParameterSymbol -> classifier.owner.toIrBasedDescriptor().defaultType
+        is IrTypeParameterSymbol -> classifier.toIrBasedDescriptorIfPossible().defaultType
         is IrClassSymbol -> {
-            val classDescriptor = classifier.owner.toIrBasedDescriptor()
+            val classDescriptor = classifier.toIrBasedDescriptorIfPossible()
             val kotlinTypeArguments = arguments.mapIndexed { index, it ->
                 when (it) {
                     is IrTypeProjection -> TypeProjectionImpl(it.variance, it.type.toIrBasedKotlinType())
@@ -1094,3 +1094,20 @@ private fun makeKotlinType(
         }
         else -> error("unknown classifier kind $classifier")
     }
+
+/* When IR-based descriptors are used from Psi2Ir, symbols may be unbound, thus we may need to resort to real descriptors. */
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+private fun IrClassSymbol.toIrBasedDescriptorIfPossible(): ClassDescriptor =
+    if (isBound) owner.toIrBasedDescriptor() else descriptor
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+private fun IrTypeParameterSymbol.toIrBasedDescriptorIfPossible(): TypeParameterDescriptor =
+    if (isBound) owner.toIrBasedDescriptor() else descriptor
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+private fun IrSimpleFunctionSymbol.toIrBasedDescriptorIfPossible(): FunctionDescriptor =
+    if (isBound) owner.toIrBasedDescriptor() else descriptor
+
+@OptIn(ObsoleteDescriptorBasedAPI::class)
+private fun IrPropertySymbol.toIrBasedDescriptorIfPossible(): PropertyDescriptor =
+    if (isBound) owner.toIrBasedDescriptor() else descriptor

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/symbols/impl/IrPrivateSymbolBase.kt

@@ -20,6 +20,7 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.WrappedDeclarationDescriptor
+import org.jetbrains.kotlin.ir.descriptors.toIrBasedDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrReturnableBlock
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.IdSignature
@@ -27,9 +28,15 @@ import org.jetbrains.kotlin.ir.util.render
 
 @OptIn(ObsoleteDescriptorBasedAPI::class)
 abstract class IrSymbolBase<out D : DeclarationDescriptor>(
+    private val _descriptor: D
+) : IrSymbol {
     @ObsoleteDescriptorBasedAPI
     override val descriptor: D
-) : IrSymbol {
+        get() = if (isBound && _descriptor is WrappedDeclarationDescriptor<*>)
+            (owner as IrDeclaration).toIrBasedDescriptor() as D
+        else
+            _descriptor
+
     override fun toString(): String {
         if (isBound) return owner.render()
         return "Unbound private symbol ${super.toString()}"

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/symbols/impl/IrPublicSymbolBase.kt

@@ -9,15 +9,22 @@ import org.jetbrains.kotlin.descriptors.*
 import org.jetbrains.kotlin.ir.ObsoleteDescriptorBasedAPI
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.WrappedDeclarationDescriptor
+import org.jetbrains.kotlin.ir.descriptors.toIrBasedDescriptor
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.render
 
 abstract class IrPublicSymbolBase<out D : DeclarationDescriptor> @OptIn(ObsoleteDescriptorBasedAPI::class) constructor(
-    @ObsoleteDescriptorBasedAPI
-    override val descriptor: D,
+    private val _descriptor: D,
     override val signature: IdSignature
 ) : IrSymbol {
+    @ObsoleteDescriptorBasedAPI
+    override val descriptor: D
+        get() = if (isBound && _descriptor is WrappedDeclarationDescriptor<*>)
+            (owner as IrDeclaration).toIrBasedDescriptor() as D
+        else
+            _descriptor
+
     override fun toString(): String {
         if (isBound) return owner.render()
         return "Unbound public symbol for $signature"

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/util/DescriptorsToIrRemapper.kt

@@ -58,34 +58,34 @@ object WrappedDescriptorPatcher : IrElementVisitorVoid {
     }
 
     override fun visitClass(declaration: IrClass) {
-        (declaration.descriptor as WrappedClassDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedClassDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitConstructor(declaration: IrConstructor) {
-        (declaration.descriptor as WrappedClassConstructorDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedClassConstructorDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitEnumEntry(declaration: IrEnumEntry) {
-        (declaration.descriptor as WrappedClassDescriptor).bind(
+        (declaration.descriptor as? WrappedClassDescriptor)?.bind(
             declaration.correspondingClass ?: declaration.parentAsClass
         )
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitField(declaration: IrField) {
-        (declaration.descriptor as WrappedFieldDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedFieldDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitProperty(declaration: IrProperty) {
-        (declaration.descriptor as WrappedPropertyDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedPropertyDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitFunction(declaration: IrFunction) {
-        (declaration.descriptor as WrappedSimpleFunctionDescriptor).bind(declaration as IrSimpleFunction)
+        (declaration.descriptor as? WrappedSimpleFunctionDescriptor)?.bind(declaration as IrSimpleFunction)
         declaration.acceptChildrenVoid(this)
     }
 
@@ -96,12 +96,12 @@ object WrappedDescriptorPatcher : IrElementVisitorVoid {
     }
 
     override fun visitTypeParameter(declaration: IrTypeParameter) {
-        (declaration.descriptor as WrappedTypeParameterDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedTypeParameterDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 
     override fun visitVariable(declaration: IrVariable) {
-        (declaration.descriptor as WrappedVariableDescriptor).bind(declaration)
+        (declaration.descriptor as? WrappedVariableDescriptor)?.bind(declaration)
         declaration.acceptChildrenVoid(this)
     }
 }