IR: drop IrTypeAlias

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ClassGenerator.kt

@@ -385,7 +385,7 @@ class ClassGenerator(
     private fun generateMembersDeclaredInClassBody(irClass: IrClass, ktClassOrObject: KtPureClassOrObject) {
         // generate real body declarations
         ktClassOrObject.body?.let { ktClassBody ->
-            ktClassBody.declarations.mapTo(irClass.declarations) { ktDeclaration ->
+            ktClassBody.declarations.mapNotNullTo(irClass.declarations) { ktDeclaration ->
                 declarationGenerator.generateClassMemberDeclaration(ktDeclaration, irClass)
             }
         }

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/DeclarationGenerator.kt

@@ -16,11 +16,12 @@
 
 package org.jetbrains.kotlin.psi2ir.generators
 
-import org.jetbrains.kotlin.descriptors.*
+import org.jetbrains.kotlin.descriptors.CallableMemberDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.descriptors.PropertyDescriptor
+import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.declarations.impl.IrErrorDeclarationImpl
-import org.jetbrains.kotlin.ir.declarations.impl.IrPropertyImpl
-import org.jetbrains.kotlin.ir.declarations.impl.IrTypeAliasImpl
 import org.jetbrains.kotlin.ir.expressions.IrExpressionBody
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
 import org.jetbrains.kotlin.ir.util.withScope
@@ -28,8 +29,6 @@ import org.jetbrains.kotlin.psi.*
 import org.jetbrains.kotlin.psi.psiUtil.endOffset
 import org.jetbrains.kotlin.psi.psiUtil.startOffsetSkippingComments
 import org.jetbrains.kotlin.psi2ir.endOffsetOrUndefined
-import org.jetbrains.kotlin.psi2ir.pureEndOffsetOrUndefined
-import org.jetbrains.kotlin.psi2ir.pureStartOffsetOrUndefined
 import org.jetbrains.kotlin.psi2ir.startOffsetOrUndefined
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.DescriptorToSourceUtils
@@ -41,7 +40,7 @@ class DeclarationGenerator(override val context: GeneratorContext) : Generator {
 
     fun KotlinType.toIrType() = typeTranslator.translateType(this)
 
-    fun generateMemberDeclaration(ktDeclaration: KtDeclaration): IrDeclaration =
+    fun generateMemberDeclaration(ktDeclaration: KtDeclaration): IrDeclaration? =
         when (ktDeclaration) {
             is KtNamedFunction ->
                 FunctionGenerator(this).generateFunctionDeclaration(ktDeclaration)
@@ -50,7 +49,7 @@ class DeclarationGenerator(override val context: GeneratorContext) : Generator {
             is KtClassOrObject ->
                 generateClassOrObjectDeclaration(ktDeclaration)
             is KtTypeAlias ->
-                generateTypeAliasDeclaration(ktDeclaration)
+                null
             else ->
                 IrErrorDeclarationImpl(
                     ktDeclaration.startOffsetSkippingComments, ktDeclaration.endOffset,
@@ -62,7 +61,7 @@ class DeclarationGenerator(override val context: GeneratorContext) : Generator {
         return generateClassOrObjectDeclaration(syntheticDeclaration)
     }
 
-    fun generateClassMemberDeclaration(ktDeclaration: KtDeclaration, irClass: IrClass): IrDeclaration =
+    fun generateClassMemberDeclaration(ktDeclaration: KtDeclaration, irClass: IrClass): IrDeclaration? =
         when (ktDeclaration) {
             is KtAnonymousInitializer ->
                 AnonymousInitializerGenerator(this).generateAnonymousInitializerDeclaration(ktDeclaration, irClass)
@@ -80,12 +79,6 @@ class DeclarationGenerator(override val context: GeneratorContext) : Generator {
     fun generateClassOrObjectDeclaration(ktClassOrObject: KtPureClassOrObject): IrClass =
         ClassGenerator(this).generateClass(ktClassOrObject)
 
-    private fun generateTypeAliasDeclaration(ktDeclaration: KtTypeAlias): IrDeclaration =
-        IrTypeAliasImpl(
-            ktDeclaration.startOffsetSkippingComments, ktDeclaration.endOffset, IrDeclarationOrigin.DEFINED,
-            getOrFail(BindingContext.TYPE_ALIAS, ktDeclaration)
-        )
-
 
     fun generateGlobalTypeParametersDeclarations(
         irTypeParametersOwner: IrTypeParametersContainer,

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/ModuleGenerator.kt

@@ -27,6 +27,7 @@ import org.jetbrains.kotlin.ir.util.IrDeserializer
 import org.jetbrains.kotlin.psi.KtFile
 import org.jetbrains.kotlin.resolve.BindingContext
 import org.jetbrains.kotlin.resolve.lazy.descriptors.findPackageFragmentForFile
+import org.jetbrains.kotlin.utils.addIfNotNull
 
 class ModuleGenerator(override val context: GeneratorContext) : Generator {
 
@@ -66,7 +67,7 @@ class ModuleGenerator(override val context: GeneratorContext) : Generator {
         }
 
         for (ktDeclaration in ktFile.declarations) {
-            irFile.declarations.add(irDeclarationGenerator.generateMemberDeclaration(ktDeclaration))
+            irFile.declarations.addIfNotNull(irDeclarationGenerator.generateMemberDeclaration(ktDeclaration))
         }
 
         return irFile

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/generators/StatementGenerator.kt

@@ -24,7 +24,6 @@ import org.jetbrains.kotlin.ir.IrStatement
 import org.jetbrains.kotlin.ir.assertCast
 import org.jetbrains.kotlin.ir.builders.Scope
 import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
-import org.jetbrains.kotlin.ir.declarations.impl.IrTypeAliasImpl
 import org.jetbrains.kotlin.ir.expressions.*
 import org.jetbrains.kotlin.ir.expressions.impl.*
 import org.jetbrains.kotlin.ir.symbols.IrSymbol
@@ -472,9 +471,10 @@ class StatementGenerator(
         LocalClassGenerator(this).generateLocalClass(classOrObject)
 
     override fun visitTypeAlias(typeAlias: KtTypeAlias, data: Nothing?): IrStatement =
-        IrTypeAliasImpl(
-            typeAlias.startOffsetSkippingComments, typeAlias.endOffset, IrDeclarationOrigin.DEFINED,
-            getOrFail(BindingContext.TYPE_ALIAS, typeAlias)
+        IrBlockImpl(
+            // Compile local type aliases to empty blocks
+            typeAlias.startOffsetSkippingComments, typeAlias.endOffset,
+            context.irBuiltIns.unitType
         )
 
     override fun visitClassLiteralExpression(expression: KtClassLiteralExpression, data: Nothing?): IrStatement =