Fir2Ir: handle type parameter signatures

Type parameter references should be deserialized.

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrClassifierStorage.kt

@@ -26,10 +26,7 @@ import org.jetbrains.kotlin.ir.builders.declarations.UNDEFINED_PARAMETER_INDEX
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrExternalPackageFragmentImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrEnumConstructorCallImpl
-import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.symbols.*
-import org.jetbrains.kotlin.ir.symbols.IrEnumEntrySymbol
-import org.jetbrains.kotlin.ir.symbols.IrTypeAliasSymbol
-import org.jetbrains.kotlin.ir.symbols.IrTypeParameterSymbol
 import org.jetbrains.kotlin.ir.symbols.impl.*
 import org.jetbrains.kotlin.ir.types.IrType
 import org.jetbrains.kotlin.ir.types.impl.IrSimpleTypeImpl
@@ -96,15 +93,15 @@ class Fir2IrClassifierStorage(
         symbolTable.leaveScope(this)
     }
 
-    internal fun preCacheTypeParameters(owner: FirTypeParameterRefsOwner) {
+    internal fun preCacheTypeParameters(owner: FirTypeParameterRefsOwner, irOwnerSymbol: IrSymbol) {
         for ((index, typeParameter) in owner.typeParameters.withIndex()) {
             val original = typeParameter.symbol.fir
             getCachedIrTypeParameter(original, index)
-                ?: createIrTypeParameterWithoutBounds(original, index)
+                ?: createIrTypeParameterWithoutBounds(original, index, irOwnerSymbol)
             if (owner is FirProperty && owner.isVar) {
                 val context = ConversionTypeContext.DEFAULT.inSetter()
                 getCachedIrTypeParameter(original, index, context)
-                    ?: createIrTypeParameterWithoutBounds(original, index, context)
+                    ?: createIrTypeParameterWithoutBounds(original, index, irOwnerSymbol, context)
             }
         }
     }
@@ -115,7 +112,7 @@ class Fir2IrClassifierStorage(
     ) {
         typeParameters = owner.typeParameters.mapIndexedNotNull { index, typeParameter ->
             if (typeParameter !is FirTypeParameter) return@mapIndexedNotNull null
-            getIrTypeParameter(typeParameter, index, typeContext).apply {
+            getIrTypeParameter(typeParameter, index, symbol, typeContext).apply {
                 parent = this@setTypeParameters
                 if (superTypes.isEmpty()) {
                     superTypes = typeParameter.bounds.map { it.toIrType() }
@@ -126,7 +123,7 @@ class Fir2IrClassifierStorage(
 
     private fun IrClass.declareTypeParameters(klass: FirClass) {
         if (klass is FirRegularClass) {
-            preCacheTypeParameters(klass)
+            preCacheTypeParameters(klass, symbol)
             setTypeParameters(klass)
             val fieldsForContextReceiversOfCurrentClass = createContextReceiverFields(klass)
             if (fieldsForContextReceiversOfCurrentClass.isNotEmpty()) {
@@ -263,9 +260,9 @@ class Fir2IrClassifierStorage(
         parent: IrFile
     ): IrTypeAlias {
         val signature = signatureComposer.composeSignature(typeAlias)
-        preCacheTypeParameters(typeAlias)
         return typeAlias.convertWithOffsets { startOffset, endOffset ->
             declareIrTypeAlias(signature) { symbol ->
+                preCacheTypeParameters(typeAlias, symbol)
                 val irTypeAlias = irFactory.createTypeAlias(
                     startOffset, endOffset, symbol,
                     typeAlias.name, components.visibilityConverter.convertToDescriptorVisibility(typeAlias.visibility),
@@ -375,13 +372,43 @@ class Fir2IrClassifierStorage(
     private fun createIrTypeParameterWithoutBounds(
         typeParameter: FirTypeParameter,
         index: Int,
-        typeContext: ConversionTypeContext = ConversionTypeContext.DEFAULT
+        ownerSymbol: IrSymbol,
+        typeContext: ConversionTypeContext = ConversionTypeContext.DEFAULT,
     ): IrTypeParameter {
         require(index >= 0)
         val origin = typeParameter.computeIrOrigin()
         val irTypeParameter = with(typeParameter) {
             convertWithOffsets { startOffset, endOffset ->
-                irFactory.createTypeParameter(
+                signatureComposer.composeTypeParameterSignature(
+                    typeParameter, index, ownerSymbol.signature
+                )?.let { signature ->
+                    if (ownerSymbol is IrClassifierSymbol) {
+                        symbolTable.declareGlobalTypeParameter(
+                            signature,
+                            symbolFactory = { IrTypeParameterPublicSymbolImpl(signature) }
+                        ) { symbol ->
+                            irFactory.createTypeParameter(
+                                startOffset, endOffset, origin, symbol,
+                                name, if (index < 0) 0 else index,
+                                isReified,
+                                variance
+                            )
+                        }
+                    } else {
+                        symbolTable.declareScopedTypeParameter(
+                            signature,
+                            symbolFactory = { IrTypeParameterPublicSymbolImpl(signature) }
+                        ) { symbol ->
+                            irFactory.createTypeParameter(
+                                startOffset, endOffset, origin, symbol,
+                                name, if (index < 0) 0 else index,
+                                isReified,
+                                variance
+                            )
+                        }
+
+                    }
+                } ?: irFactory.createTypeParameter(
                     startOffset, endOffset, origin, IrTypeParameterSymbolImpl(),
                     name, if (index < 0) 0 else index,
                     isReified,
@@ -428,11 +455,12 @@ class Fir2IrClassifierStorage(
     internal fun getIrTypeParameter(
         typeParameter: FirTypeParameter,
         index: Int,
+        ownerSymbol: IrSymbol,
         typeContext: ConversionTypeContext = ConversionTypeContext.DEFAULT
     ): IrTypeParameter {
         getCachedIrTypeParameter(typeParameter, index, typeContext)?.let { return it }
         return typeParameter.run {
-            val irTypeParameter = createIrTypeParameterWithoutBounds(typeParameter, index, typeContext)
+            val irTypeParameter = createIrTypeParameterWithoutBounds(typeParameter, index, ownerSymbol, typeContext)
             irTypeParameter.superTypes = bounds.map { it.toIrType() }
             irTypeParameter
         }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrDeclarationStorage.kt

@@ -509,7 +509,6 @@ class Fir2IrDeclarationStorage(
             // For private functions signature is null, fallback to non-lazy function
             return createIrLazyFunction(function as FirSimpleFunction, signature, irParent, updatedOrigin)
         }
-        classifierStorage.preCacheTypeParameters(function)
         val name = simpleFunction?.name
             ?: if (isLambda) SpecialNames.ANONYMOUS else Name.special("<no name provided>")
         val visibility = simpleFunction?.visibility ?: Visibilities.Local
@@ -518,6 +517,7 @@ class Fir2IrDeclarationStorage(
             else simpleFunction?.isSuspend == true
         val created = function.convertWithOffsets { startOffset, endOffset ->
             val result = declareIrSimpleFunction(signature, simpleFunction?.containerSource) { symbol ->
+                classifierStorage.preCacheTypeParameters(function, symbol)
                 irFactory.createFunction(
                     startOffset, endOffset, updatedOrigin, symbol,
                     name, components.visibilityConverter.convertToDescriptorVisibility(visibility),
@@ -602,10 +602,10 @@ class Fir2IrDeclarationStorage(
     ): IrConstructor = convertCatching(constructor) {
         val origin = constructor.computeIrOrigin(predefinedOrigin)
         val isPrimary = constructor.isPrimary
-        classifierStorage.preCacheTypeParameters(constructor)
         val signature = if (isLocal) null else signatureComposer.composeSignature(constructor)
         val created = constructor.convertWithOffsets { startOffset, endOffset ->
             declareIrConstructor(signature) { symbol ->
+                classifierStorage.preCacheTypeParameters(constructor, symbol)
                 irFactory.createConstructor(
                     startOffset, endOffset, origin, symbol,
                     SpecialNames.INIT, components.visibilityConverter.convertToDescriptorVisibility(constructor.visibility),
@@ -829,14 +829,9 @@ class Fir2IrDeclarationStorage(
             // For private functions signature is null, fallback to non-lazy property
             return createIrLazyProperty(property, signature, irParent, origin)
         }
-        classifierStorage.preCacheTypeParameters(property)
-        if (property.delegate != null) {
-            ((property.delegate as? FirQualifiedAccess)?.calleeReference?.resolvedSymbol?.fir as? FirTypeParameterRefsOwner)?.let {
-                classifierStorage.preCacheTypeParameters(it)
-            }
-        }
         return property.convertWithOffsets { startOffset, endOffset ->
             val result = declareIrProperty(signature, property.containerSource) { symbol ->
+                classifierStorage.preCacheTypeParameters(property, symbol)
                 irFactory.createProperty(
                     startOffset, endOffset, origin, symbol,
                     property.name, components.visibilityConverter.convertToDescriptorVisibility(property.visibility), property.modality!!,
@@ -861,6 +856,9 @@ class Fir2IrDeclarationStorage(
                     val setter = property.setter
                     if (delegate != null || property.hasBackingField) {
                         backingField = if (delegate != null) {
+                            ((delegate as? FirQualifiedAccess)?.calleeReference?.resolvedSymbol?.fir as? FirTypeParameterRefsOwner)?.let {
+                                classifierStorage.preCacheTypeParameters(it, symbol)
+                            }
                             createBackingField(
                                 property, IrDeclarationOrigin.PROPERTY_DELEGATE,
                                 components.visibilityConverter.convertToDescriptorVisibility(property.fieldVisibility),

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrSignatureComposer.kt

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.fir.backend
 
 import org.jetbrains.kotlin.fir.declarations.FirDeclaration
 import org.jetbrains.kotlin.fir.declarations.FirProperty
+import org.jetbrains.kotlin.fir.declarations.FirTypeParameter
 import org.jetbrains.kotlin.fir.signaturer.FirMangler
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.ir.util.IdSignature
@@ -15,5 +16,6 @@ interface Fir2IrSignatureComposer {
     val mangler: FirMangler
     fun composeSignature(declaration: FirDeclaration, containingClass: ConeClassLikeLookupTag? = null): IdSignature?
     fun composeAccessorSignature(property: FirProperty, isSetter: Boolean, containingClass: ConeClassLikeLookupTag? = null): IdSignature?
+    fun composeTypeParameterSignature(typeParameter: FirTypeParameter, index: Int, containerSignature: IdSignature?): IdSignature?
     fun withFileSignature(sig: IdSignature.FileSignature, body: () -> Unit)
 }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/FirIrProvider.kt

@@ -15,10 +15,7 @@ import org.jetbrains.kotlin.fir.scopes.unsubstitutedScope
 import org.jetbrains.kotlin.fir.symbols.SymbolInternals
 import org.jetbrains.kotlin.fir.symbols.impl.FirPropertySymbol
 import org.jetbrains.kotlin.fir.types.ConeClassLikeType
-import org.jetbrains.kotlin.ir.declarations.IrClass
+import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.IrDeclarationParent
-import org.jetbrains.kotlin.ir.declarations.IrProperty
 import org.jetbrains.kotlin.ir.linkage.IrProvider
 import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.IdSignature
@@ -56,7 +53,12 @@ class FirIrProvider(val fir2IrComponents: Fir2IrComponents) : IrProvider {
 
     private fun getDeclarationForCompositeSignature(signature: IdSignature.CompositeSignature, kind: SymbolKind): IrDeclaration? {
         if (kind == SymbolKind.TYPE_PARAMETER_SYMBOL) {
-            TODO()
+            val container = (getDeclarationForSignature(signature.container, SymbolKind.CLASS_SYMBOL)
+                ?: getDeclarationForSignature(signature.container, SymbolKind.FUNCTION_SYMBOL)
+                ?: getDeclarationForSignature(signature.container, SymbolKind.PROPERTY_SYMBOL)
+            ) as IrTypeParametersContainer
+            val localSignature = signature.inner as IdSignature.LocalSignature
+            return container.typeParameters[localSignature.index()]
         }
         return getDeclarationForSignature(signature.nearestPublicSig(), kind)
     }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/generators/FakeOverrideGenerator.kt

@@ -35,6 +35,7 @@ import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.types.*
 import org.jetbrains.kotlin.ir.util.IdSignature
 import org.jetbrains.kotlin.ir.util.parentAsClass
+import org.jetbrains.kotlin.ir.util.withScope
 import org.jetbrains.kotlin.load.java.JavaDescriptorVisibilities
 import org.jetbrains.kotlin.name.Name
 
@@ -220,7 +221,6 @@ class FakeOverrideGenerator(
                 // We've got no relevant declaration in FIR world for such a fake override in current class, thus we're creating it here
                 val fakeOverrideSymbol = createFakeOverrideSymbol(originalDeclaration, baseSymbol)
                 declarationStorage.saveFakeOverrideInClass(irClass, originalDeclaration, fakeOverrideSymbol.fir)
-                classifierStorage.preCacheTypeParameters(originalDeclaration)
                 fakeOverrideSymbol.fir to listOf(originalSymbol)
             }
             else -> {
@@ -274,7 +274,7 @@ class FakeOverrideGenerator(
                 // We've got no relevant declaration in FIR world for such a fake override in current class, thus we're creating it here
                 val fakeOverrideSymbol = createFakeOverrideSymbol(originalDeclaration, baseSymbol)
                 declarationStorage.saveFakeOverrideInClass(irClass, originalDeclaration, fakeOverrideSymbol.fir)
-                classifierStorage.preCacheTypeParameters(originalDeclaration)
+                classifierStorage.preCacheTypeParameters(originalDeclaration, irClass.symbol)
                 fakeOverrideSymbol.fir to listOf(originalSymbol)
             }
             else -> {

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyClass.kt

@@ -44,7 +44,7 @@ class Fir2IrLazyClass(
     IrMaybeDeserializedClass, DeserializableClass, Fir2IrComponents by components {
     init {
         symbol.bind(this)
-        classifierStorage.preCacheTypeParameters(fir)
+        classifierStorage.preCacheTypeParameters(fir, symbol)
     }
 
     override var annotations: List<IrConstructorCall> by createLazyAnnotations()

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyConstructor.kt

@@ -39,7 +39,7 @@ class Fir2IrLazyConstructor(
     Fir2IrComponents by components {
     init {
         symbol.bind(this)
-        classifierStorage.preCacheTypeParameters(fir)
+        classifierStorage.preCacheTypeParameters(fir, symbol)
     }
 
     override var annotations: List<IrConstructorCall> by createLazyAnnotations()

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazyProperty.kt

@@ -45,7 +45,7 @@ class Fir2IrLazyProperty(
 ) : IrProperty(), AbstractFir2IrLazyDeclaration<FirProperty>, Fir2IrComponents by components {
     init {
         symbol.bind(this)
-        classifierStorage.preCacheTypeParameters(fir)
+        classifierStorage.preCacheTypeParameters(fir, symbol)
     }
 
     override var annotations: List<IrConstructorCall> by createLazyAnnotations()

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrLazySimpleFunction.kt

@@ -33,7 +33,7 @@ class Fir2IrLazySimpleFunction(
 ) : AbstractFir2IrLazyFunction<FirSimpleFunction>(components, startOffset, endOffset, origin, symbol, isFakeOverride) {
     init {
         symbol.bind(this)
-        classifierStorage.preCacheTypeParameters(fir)
+        classifierStorage.preCacheTypeParameters(fir, symbol)
     }
 
     override var annotations: List<IrConstructorCall> by createLazyAnnotations()

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/lazy/Fir2IrTypeParametersContainer.kt

@@ -17,7 +17,7 @@ interface Fir2IrTypeParametersContainer : IrTypeParametersContainer, Fir2IrCompo
     fun prepareTypeParameters() {
         typeParameters = fir.typeParameters.mapIndexedNotNull { index, typeParameter ->
             if (typeParameter !is FirTypeParameter) return@mapIndexedNotNull null
-            classifierStorage.getIrTypeParameter(typeParameter, index).apply {
+            classifierStorage.getIrTypeParameter(typeParameter, index, symbol).apply {
                 parent = this@Fir2IrTypeParametersContainer
                 if (superTypes.isEmpty()) {
                     superTypes = typeParameter.bounds.map { it.toIrType(typeConverter) }

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/signaturer/FirBasedSignatureComposer.kt

@@ -5,6 +5,7 @@
 
 package org.jetbrains.kotlin.fir.signaturer
 
+import org.jetbrains.kotlin.backend.common.serialization.mangle.MangleConstant
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.fir.*
 import org.jetbrains.kotlin.fir.backend.Fir2IrSignatureComposer
@@ -17,6 +18,7 @@ import org.jetbrains.kotlin.fir.declarations.utils.visibility
 import org.jetbrains.kotlin.fir.symbols.ConeClassLikeLookupTag
 import org.jetbrains.kotlin.fir.visitors.FirVisitor
 import org.jetbrains.kotlin.ir.util.IdSignature
+import org.jetbrains.kotlin.name.ClassId
 
 // @NoMutableState -- we'll restore this annotation once we get rid of withFileSignature().
 class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignatureComposer {
@@ -118,6 +120,18 @@ class FirBasedSignatureComposer(override val mangler: FirMangler) : Fir2IrSignat
             publicSignature
     }
 
+    override fun composeTypeParameterSignature(
+        typeParameter: FirTypeParameter,
+        index: Int,
+        containerSignature: IdSignature?
+    ): IdSignature? {
+        if (containerSignature == null) return null
+        return IdSignature.CompositeSignature(
+             containerSignature,
+             IdSignature.LocalSignature(MangleConstant.TYPE_PARAMETER_MARKER_NAME, index.toLong(), null)
+        )
+    }
+
     override fun composeAccessorSignature(
         property: FirProperty,
         isSetter: Boolean,