Eliminate a set of warnings, mostly nullability ones

compiler/cli/cli-common/src/org/jetbrains/kotlin/cli/common/repl/GenericReplCompilingEvaluator.kt

@@ -63,10 +63,8 @@ class GenericReplCompilingEvaluator(val compiler: ReplCompiler,
                         is ReplEvalResult.ValueResult,
                         is ReplEvalResult.UnitResult ->
                             result
-                        else -> throw IllegalStateException("Unknown evaluator result type $compiled")
                     }
                 }
-                else -> throw IllegalStateException("Unknown compiler result type $compiled")
             }
         }
     }

compiler/daemon/daemon-client/src/org/jetbrains/kotlin/daemon/client/KotlinCompilerClient.kt

@@ -325,7 +325,7 @@ object KotlinCompilerClient {
                 if (err != null) {
                     reportingTargets.report(DaemonReportCategory.INFO,
                                             (if (attempts >= DAEMON_CONNECT_CYCLE_ATTEMPTS || !autostart) "no more retries on: " else "retrying($attempts) on: ")
-                                            + err?.toString())
+                                            + err.toString())
                 }
 
                 if (attempts++ > DAEMON_CONNECT_CYCLE_ATTEMPTS || !autostart) {

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/checkers/ExternalFunChecker.kt

@@ -51,8 +51,7 @@ class ExternalFunChecker : SimpleDeclarationChecker {
         if (DescriptorUtils.isInterface(descriptor.containingDeclaration)) {
             diagnosticHolder.report(ErrorsJvm.EXTERNAL_DECLARATION_IN_INTERFACE.on(declaration))
         }
-        else if (descriptor is CallableMemberDescriptor &&
-                 descriptor.modality == Modality.ABSTRACT) {
+        else if (descriptor.modality == Modality.ABSTRACT) {
             if (declaration is KtPropertyAccessor) {
                 diagnosticHolder.report(ErrorsJvm.EXTERNAL_DECLARATION_CANNOT_BE_ABSTRACT.on(declaration.property))
             }

compiler/frontend/src/org/jetbrains/kotlin/psi/KtCodeFragment.kt

@@ -163,7 +163,7 @@ abstract class KtCodeFragment(
     }
 
     fun getContextContainingFile(): KtFile? {
-        return (getOriginalContext() as? KtElement)?.containingKtFile
+        return getOriginalContext()?.containingKtFile
     }
 
     fun getOriginalContext(): KtElement? {

compiler/frontend/src/org/jetbrains/kotlin/psi/KtEnumEntrySuperclassReferenceExpression.kt

@@ -40,7 +40,7 @@ class KtEnumEntrySuperclassReferenceExpression :
             get() = calcReferencedElement()!!
 
     private fun calcReferencedElement(): KtClass? {
-        val owner = this.getStrictParentOfType<KtEnumEntry>() as? KtEnumEntry
+        val owner = this.getStrictParentOfType<KtEnumEntry>()
         return owner?.parent?.parent as? KtClass
     }
 

compiler/frontend/src/org/jetbrains/kotlin/resolve/checkers/ConstModifierChecker.kt

@@ -65,7 +65,7 @@ object ConstModifierChecker : SimpleDeclarationChecker {
             return Errors.CONST_VAL_WITH_DELEGATE.on(declaration.delegate!!).nonApplicable()
         }
 
-        if (descriptor is PropertyDescriptor && !descriptor.getter!!.isDefault) {
+        if (!descriptor.getter!!.isDefault) {
             return Errors.CONST_VAL_WITH_GETTER.on(declaration.getter!!).nonApplicable()
         }
 

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/LabelResolver.kt

@@ -90,6 +90,7 @@ object LabelResolver {
 
         if (parent is KtValueArgument) {
             // f ({}) or f(p = {}) or f (fun () {})
+            // NB: parent of KtElement is really nullable!!!
             val argList = parent.parent ?: return null
             val call = argList.parent
             if (call is KtCallExpression) {

compiler/incremental-compilation-impl/src/org/jetbrains/kotlin/incremental/IncrementalJvmCompilerRunner.kt

@@ -272,7 +272,6 @@ class IncrementalJvmCompilerRunner(
                 // there is no point in updating annotation file since all files will be compiled anyway
                 kaptAnnotationsFileUpdater = null
             }
-            else -> throw IllegalStateException("Unknown CompilationMode ${compilationMode::class.java}")
         }
 
         val currentBuildInfo = BuildInfo(startTS = System.currentTimeMillis())

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/lower/DefaultArgumentStubGenerator.kt

@@ -195,7 +195,7 @@ private fun Scope.createTemporaryVariable(symbol: IrVariableSymbol, initializer:
         }
 
 private fun getDefaultParameterExpressionBody(irFunction: IrFunction, valueParameter: ValueParameterDescriptor):IrExpressionBody {
-    return irFunction.getDefault(valueParameter) as? IrExpressionBody ?: TODO("FIXME!!!")
+    return irFunction.getDefault(valueParameter) ?: TODO("FIXME!!!")
 }
 
 private fun maskParameterDescriptor(function: IrFunction, number: Int) =

compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/intrinsics/CompareTo.kt

@@ -23,7 +23,6 @@ import org.jetbrains.kotlin.codegen.AsmUtil.comparisonOperandType
 import org.jetbrains.kotlin.codegen.AsmUtil.isPrimitive
 import org.jetbrains.kotlin.codegen.OwnerKind
 import org.jetbrains.kotlin.codegen.StackValue
-import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrMemberAccessExpression
 import org.jetbrains.kotlin.ir.expressions.IrStatementOrigin
@@ -68,10 +67,10 @@ class IrCompareTo : IntrinsicMethod() {
         val rightType = argTypes[1]
         val parameterType = comparisonOperandType(leftType, rightType)
 
-        val newSignature = context.state.typeMapper.mapSignatureSkipGeneric(compareCall.descriptor as FunctionDescriptor, OwnerKind.IMPLEMENTATION)
+        val newSignature = context.state.typeMapper.mapSignatureSkipGeneric(compareCall.descriptor, OwnerKind.IMPLEMENTATION)
         return object : IrIntrinsicFunction(compareCall, newSignature, context, listOf(parameterType, parameterType)) {
             override fun invoke(v: InstructionAdapter, codegen: ExpressionCodegen, data: BlockInfo): StackValue {
-                val isPrimitiveIntrinsic = codegen.intrinsics.intrinsics.getIntrinsic(compareCall.descriptor as FunctionDescriptor) != null
+                val isPrimitiveIntrinsic = codegen.intrinsics.intrinsics.getIntrinsic(compareCall.descriptor) != null
                 val operationType: Type
                 val leftValue: StackValue
                 val rightValue: StackValue

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

@@ -81,7 +81,7 @@ class ContextAnnotator(val state: GenerationState) : ClassLowerWithContext() {
 
     override fun lowerBefore(irClass: IrClass, data: IrClassContext) {
         val descriptor = irClass.descriptor
-        val newContext: CodegenContext<*> = if (descriptor is FileClassDescriptor || descriptor !is ClassDescriptor) {
+        val newContext: CodegenContext<*> = if (descriptor is FileClassDescriptor) {
             StubCodegenContext(descriptor, data.parent?.codegenContext, data)
         }
         else {

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/declarations/impl/IrFieldImpl.kt

@@ -59,6 +59,6 @@ class IrFieldImpl(
     }
 
     override fun <D> transformChildren(transformer: IrElementTransformer<D>, data: D) {
-        initializer = initializer?.transform(transformer, data) as? IrExpressionBody
+        initializer = initializer?.transform(transformer, data)
     }
 }

compiler/light-classes/src/org/jetbrains/kotlin/asJava/elements/KtLightMethodImpl.kt

@@ -114,7 +114,7 @@ class KtLightMethodImpl private constructor(
         if (calculatingReturnType.get() == true) {
             return KotlinJavaPsiFacade.getInstance(project).emptyModifierList
         }
-        return super.getModifierList()!!
+        return super.getModifierList()
     }
 
     override fun getParameterList() = paramsList
@@ -235,7 +235,7 @@ fun KtLightMethod.isTraitFakeOverride(): Boolean {
     }
 
     val parentOfMethodOrigin = PsiTreeUtil.getParentOfType(methodOrigin, KtClassOrObject::class.java)
-    val thisClassDeclaration = (this.containingClass as KtLightClass).kotlinOrigin
+    val thisClassDeclaration = this.containingClass.kotlinOrigin
 
     // Method was generated from declaration in some other trait
     return (parentOfMethodOrigin != null && thisClassDeclaration !== parentOfMethodOrigin && KtPsiUtil.isTrait(parentOfMethodOrigin))

compiler/tests/org/jetbrains/kotlin/daemon/CompilerDaemonTest.kt

@@ -670,7 +670,7 @@ class CompilerDaemonTest : KotlinIntegrationTestBase() {
 
     fun testDaemonReplLocalEvalNoParams() {
         withDaemon { daemon ->
-            val repl = KotlinRemoteReplCompilerClient(daemon!!, null, CompileService.TargetPlatform.JVM,
+            val repl = KotlinRemoteReplCompilerClient(daemon, null, CompileService.TargetPlatform.JVM,
                                                       emptyArray(),
                                                       TestMessageCollector(),
                                                       classpathFromClassloader(),
@@ -685,7 +685,7 @@ class CompilerDaemonTest : KotlinIntegrationTestBase() {
 
     fun testDaemonReplLocalEvalStandardTemplate() {
         withDaemon { daemon ->
-            val repl = KotlinRemoteReplCompilerClient(daemon!!, null, CompileService.TargetPlatform.JVM, emptyArray(),
+            val repl = KotlinRemoteReplCompilerClient(daemon, null, CompileService.TargetPlatform.JVM, emptyArray(),
                                                       TestMessageCollector(),
                                                       classpathFromClassloader(),
                                                       "kotlin.script.templates.standard.ScriptTemplateWithArgs")