[FIR2IR] Use IrSymbols directly instead of referencing via SymbolTable

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

@@ -350,12 +350,11 @@ class Fir2IrClassifierStorage(
 
     fun getIrClassSymbol(firClassSymbol: FirClassSymbol<*>): IrClassSymbol {
         val firClass = firClassSymbol.fir
-        getCachedIrClass(firClass)?.let { return symbolTable.referenceClass(it.descriptor) }
-        // TODO: remove all this code and change to unbound symbol creation
+        getCachedIrClass(firClass)?.let { return it.symbol }
         if (firClass is FirAnonymousObject || firClass is FirRegularClass && firClass.visibility == Visibilities.LOCAL) {
-            val irClass = createIrClass(firClass)
-            return symbolTable.referenceClass(irClass.descriptor)
+            return createIrClass(firClass).symbol
         }
+        // TODO: remove all this code and change to unbound symbol creation
         val classId = firClassSymbol.classId
         val parentId = classId.outerClassId
         val irParent = declarationStorage.findIrParent(classId.packageFqName, parentId, firClassSymbol)
@@ -365,15 +364,14 @@ class Fir2IrClassifierStorage(
             declarationStorage.addDeclarationsToExternalClass(firClass as FirRegularClass, irClass)
         }
 
-        return symbolTable.referenceClass(irClass.descriptor)
+        return irClass.symbol
     }
 
     fun getIrTypeParameterSymbol(
         firTypeParameterSymbol: FirTypeParameterSymbol,
         typeContext: ConversionTypeContext
     ): IrTypeParameterSymbol {
-        val irTypeParameter = getCachedIrTypeParameter(firTypeParameterSymbol.fir, typeContext = typeContext)
+        return getCachedIrTypeParameter(firTypeParameterSymbol.fir, typeContext = typeContext)?.symbol
             ?: throw AssertionError("Cannot find cached type parameter by FIR symbol: ${firTypeParameterSymbol.name}")
-        return symbolTable.referenceTypeParameter(irTypeParameter.descriptor)
     }
 }

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

@@ -857,26 +857,25 @@ class Fir2IrDeclarationStorage(
 
     fun getIrConstructorSymbol(firConstructorSymbol: FirConstructorSymbol): IrConstructorSymbol {
         val firConstructor = firConstructorSymbol.fir
-        getCachedIrConstructor(firConstructor)?.let { return symbolTable.referenceConstructor(it.descriptor) }
+        getCachedIrConstructor(firConstructor)?.let { return it.symbol }
 
         val irParent = findIrParent(firConstructor) as IrClass
         val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
         val irDeclaration = createIrConstructor(firConstructor, irParent, origin = parentOrigin).apply {
             setAndModifyParent(irParent)
         }
-        return symbolTable.referenceConstructor(irDeclaration.descriptor)
+        return irDeclaration.symbol
     }
 
     fun getIrFunctionSymbol(firFunctionSymbol: FirFunctionSymbol<*>): IrFunctionSymbol {
         return when (val firDeclaration = firFunctionSymbol.fir) {
             is FirSimpleFunction, is FirAnonymousFunction -> {
-                getCachedIrFunction(firDeclaration)?.let { return symbolTable.referenceSimpleFunction(it.descriptor) }
+                getCachedIrFunction(firDeclaration)?.let { return it.symbol }
                 val irParent = findIrParent(firDeclaration)
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
-                val irDeclaration = createIrFunction(firDeclaration, irParent, origin = parentOrigin).apply {
+                createIrFunction(firDeclaration, irParent, origin = parentOrigin).apply {
                     setAndModifyParent(irParent)
-                }
-                symbolTable.referenceSimpleFunction(irDeclaration.descriptor)
+                }.symbol
             }
             is FirConstructor -> {
                 getIrConstructorSymbol(firDeclaration.symbol)
@@ -888,20 +887,18 @@ class Fir2IrDeclarationStorage(
     fun getIrPropertyOrFieldSymbol(firVariableSymbol: FirVariableSymbol<*>): IrSymbol {
         return when (val fir = firVariableSymbol.fir) {
             is FirProperty -> {
-                propertyCache[fir]?.let { return symbolTable.referenceProperty(it.descriptor) }
+                propertyCache[fir]?.let { return it.symbol }
                 val irParent = findIrParent(fir)
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
-                val irProperty = createIrProperty(fir, irParent, origin = parentOrigin).apply {
+                createIrProperty(fir, irParent, origin = parentOrigin).apply {
                     setAndModifyParent(irParent)
-                }
-                symbolTable.referenceProperty(irProperty.descriptor)
+                }.symbol
             }
             is FirField -> {
-                fieldCache[fir]?.let { return symbolTable.referenceField(it.descriptor) }
-                val irField = createIrField(fir).apply {
+                fieldCache[fir]?.let { return it.symbol }
+                createIrField(fir).apply {
                     setAndModifyParent(findIrParent(fir))
-                }
-                symbolTable.referenceField(irField.descriptor)
+                }.symbol
             }
             else -> throw IllegalArgumentException("Unexpected fir in property symbol: ${fir.render()}")
         }
@@ -910,13 +907,12 @@ class Fir2IrDeclarationStorage(
     fun getIrBackingFieldSymbol(firVariableSymbol: FirVariableSymbol<*>): IrSymbol {
         return when (val fir = firVariableSymbol.fir) {
             is FirProperty -> {
-                propertyCache[fir]?.let { return symbolTable.referenceField(it.backingField!!.descriptor) }
+                propertyCache[fir]?.let { return it.backingField!!.symbol }
                 val irParent = findIrParent(fir)
                 val parentOrigin = (irParent as? IrDeclaration)?.origin ?: IrDeclarationOrigin.DEFINED
-                val irProperty = createIrProperty(fir, irParent, origin = parentOrigin).apply {
+                createIrProperty(fir, irParent, origin = parentOrigin).apply {
                     setAndModifyParent(irParent)
-                }
-                symbolTable.referenceField(irProperty.backingField!!.descriptor)
+                }.backingField!!.symbol
             }
             else -> {
                 getIrVariableSymbol(fir)
@@ -925,31 +921,28 @@ class Fir2IrDeclarationStorage(
     }
 
     private fun getIrVariableSymbol(firVariable: FirVariable<*>): IrVariableSymbol {
-        val irDeclaration = localStorage.getVariable(firVariable)
+        return localStorage.getVariable(firVariable)?.symbol
             ?: throw IllegalArgumentException("Cannot find variable ${firVariable.render()} in local storage")
-        return symbolTable.referenceVariable(irDeclaration.descriptor)
     }
 
     fun getIrValueSymbol(firVariableSymbol: FirVariableSymbol<*>): IrSymbol {
         return when (val firDeclaration = firVariableSymbol.fir) {
             is FirEnumEntry -> {
-                classifierStorage.getCachedIrEnumEntry(firDeclaration)?.let { return symbolTable.referenceEnumEntry(it.descriptor) }
+                classifierStorage.getCachedIrEnumEntry(firDeclaration)?.let { return it.symbol }
                 val containingFile = firProvider.getFirCallableContainerFile(firVariableSymbol)
                 val parentClassSymbol = firVariableSymbol.callableId.classId?.let { firSymbolProvider.getClassLikeSymbolByFqName(it) }
                 val irParentClass = (parentClassSymbol?.fir as? FirClass<*>)?.let { classifierStorage.getCachedIrClass(it) }
-                val irEnumEntry = classifierStorage.createIrEnumEntry(
+                classifierStorage.createIrEnumEntry(
                     firDeclaration,
                     irParent = irParentClass,
                     origin = if (containingFile != null) IrDeclarationOrigin.DEFINED else
                         (parentClassSymbol?.fir as? FirClass<*>)?.irOrigin(firProvider) ?: IrDeclarationOrigin.IR_EXTERNAL_DECLARATION_STUB
-                )
-                symbolTable.referenceEnumEntry(irEnumEntry.descriptor)
+                ).symbol
             }
             is FirValueParameter -> {
-                val irDeclaration = localStorage.getParameter(firDeclaration)
+                localStorage.getParameter(firDeclaration)?.symbol
                 // catch parameter is FirValueParameter in FIR but IrVariable in IR
                     ?: return getIrVariableSymbol(firDeclaration)
-                symbolTable.referenceValueParameter(irDeclaration.descriptor)
             }
             else -> {
                 getIrVariableSymbol(firDeclaration)

compiler/fir/fir2ir/src/org/jetbrains/kotlin/fir/backend/Fir2IrVisitor.kt

@@ -233,12 +233,12 @@ class Fir2IrVisitor(
         val irTarget = conversionScope.returnTarget(returnExpression)
         return returnExpression.convertWithOffsets { startOffset, endOffset ->
             val result = returnExpression.result
-            val descriptor = irTarget.descriptor
             IrReturnImpl(
                 startOffset, endOffset, irBuiltIns.nothingType,
-                when (descriptor) {
-                    is ClassConstructorDescriptor -> symbolTable.referenceConstructor(descriptor)
-                    else -> symbolTable.referenceSimpleFunction(descriptor)
+                when (irTarget) {
+                    is IrConstructor -> irTarget.symbol
+                    is IrSimpleFunction -> irTarget.symbol
+                    else -> throw AssertionError("Should not be here: $irTarget")
                 },
                 convertToIrExpression(result)
             )