JVM IR: rename JvmBackendContext.getClass and return symbol instead of descriptor

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmBackendContext.kt

@@ -18,6 +18,7 @@ import org.jetbrains.kotlin.ir.declarations.IrFile
 import org.jetbrains.kotlin.ir.declarations.IrModuleFragment
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
+import org.jetbrains.kotlin.ir.util.ReferenceSymbolTable
 import org.jetbrains.kotlin.ir.util.SymbolTable
 import org.jetbrains.kotlin.name.FqName
 import org.jetbrains.kotlin.psi2ir.PsiSourceManager
@@ -34,16 +35,18 @@ class JvmBackendContext(
     override val declarationFactory: JvmDeclarationFactory = JvmDeclarationFactory(state)
     override val sharedVariablesManager = JvmSharedVariablesManager(state.module, builtIns, irBuiltIns)
 
-    override val ir = JvmIr(irModuleFragment, symbolTable)
+    private val symbolTable = symbolTable.lazyWrapper
+    override val ir = JvmIr(irModuleFragment, this.symbolTable)
 
     override var inVerbosePhase: Boolean = false
 
     override val configuration get() = state.configuration
 
-    internal fun getClass(fqName: FqName): ClassDescriptor {
-        return state.module.getPackage(fqName.parent()).memberScope.getContributedClassifier(
+    internal fun getTopLevelClass(fqName: FqName): IrClassSymbol {
+        val descriptor = state.module.getPackage(fqName.parent()).memberScope.getContributedClassifier(
             fqName.shortName(), NoLookupLocation.FROM_BACKEND
         ) as ClassDescriptor? ?: error("Class is not found: $fqName")
+        return symbolTable.referenceClass(descriptor)
     }
 
     override fun log(message: () -> String) {
@@ -58,8 +61,11 @@ class JvmBackendContext(
         print(message)
     }
 
-    inner class JvmIr(irModuleFragment: IrModuleFragment, symbolTable: SymbolTable) : Ir<JvmBackendContext>(this, irModuleFragment) {
-        override val symbols = JvmSymbols(this@JvmBackendContext, symbolTable.lazyWrapper)
+    inner class JvmIr(
+        irModuleFragment: IrModuleFragment,
+        symbolTable: ReferenceSymbolTable
+    ) : Ir<JvmBackendContext>(this, irModuleFragment) {
+        override val symbols = JvmSymbols(this@JvmBackendContext, symbolTable)
 
         override fun shouldGenerateHandlerParameterForDefaultBodyFun() = true
     }

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/JvmSymbols.kt

@@ -76,7 +76,7 @@ class JvmSymbols(
         intrinsicsClass.functions.single { it.owner.name.asString() == "throwUninitializedPropertyAccessException" }
 
     override val stringBuilder: IrClassSymbol
-        get() = symbolTable.referenceClass(context.getClass(FqName("java.lang.StringBuilder")))
+        get() = context.getTopLevelClass(FqName("java.lang.StringBuilder"))
 
     override val defaultConstructorMarker: IrClassSymbol =
         createClass(FqName("kotlin.jvm.internal.DefaultConstructorMarker")) { }.symbol
@@ -91,7 +91,7 @@ class JvmSymbols(
         get() = TODO("not implemented")
 
     val javaLangClass: IrClassSymbol =
-        symbolTable.referenceClass(context.getClass(FqName("java.lang.Class")))
+        context.getTopLevelClass(FqName("java.lang.Class"))
 
     val lambdaClass: IrClassSymbol = createClass(FqName("kotlin.jvm.internal.Lambda")) { klass ->
         klass.addConstructor().apply {

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/lower/CallableReferenceLowering.kt

@@ -211,8 +211,7 @@ internal class CallableReferenceLowering(val context: JvmBackendContext) : FileL
                 lastParameterType.classOrNull?.owner?.fqNameWhenAvailable?.asString() == "kotlin.coroutines.experimental.Continuation"
             ) {
                 // If the last parameter is Continuation<> inherit from SuspendFunction.
-                val suspendFunctionDescriptor = context.getClass(FqName("kotlin.coroutines.SuspendFunction${numberOfParameters - 1}"))
-                suspendFunctionClass = context.ir.symbols.externalSymbolTable.referenceClass(suspendFunctionDescriptor).owner
+                suspendFunctionClass = context.getTopLevelClass(FqName("kotlin.coroutines.SuspendFunction${numberOfParameters - 1}")).owner
                 val suspendFunctionClassTypeParameters = functionParameterTypes.dropLast(1) +
                         (lastParameterType.arguments.single() as IrTypeProjection).type
                 functionReferenceClassSuperTypes += IrSimpleTypeImpl(