From edab3e3ba9cda723160dfad72f059a462650252d Mon Sep 17 00:00:00 2001
From: Roman Artemev <roman.artemev@jetbrains.com>
Date: Tue, 21 Jul 2020 16:35:28 +0300
Subject: [PATCH] [PLUGIN API] Add `referenceTypeAlias` API to
 `IrPluginContext`

 - attempt to fix KT-40193
---
 .../backend/common/extensions/IrPluginContext.kt       |  6 ++----
 .../backend/common/extensions/IrPluginContextImpl.kt   | 10 ++++++++++
 2 files changed, 12 insertions(+), 4 deletions(-)

diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContext.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContext.kt
index e51e39fc902..ea672085ee6 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContext.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContext.kt
@@ -9,10 +9,7 @@ import org.jetbrains.kotlin.backend.common.ir.BuiltinSymbolsBase
 import org.jetbrains.kotlin.config.LanguageVersionSettings
 import org.jetbrains.kotlin.descriptors.ModuleDescriptor
 import org.jetbrains.kotlin.ir.builders.IrGeneratorContext
-import org.jetbrains.kotlin.ir.symbols.IrClassSymbol
-import org.jetbrains.kotlin.ir.symbols.IrConstructorSymbol
-import org.jetbrains.kotlin.ir.symbols.IrPropertySymbol
-import org.jetbrains.kotlin.ir.symbols.IrSimpleFunctionSymbol
+import org.jetbrains.kotlin.ir.symbols.*
 import org.jetbrains.kotlin.ir.util.ReferenceSymbolTable
 import org.jetbrains.kotlin.ir.util.TypeTranslator
 import org.jetbrains.kotlin.name.FqName
@@ -40,6 +37,7 @@ interface IrPluginContext : IrGeneratorContext {
 
     // The following API is experimental
     fun referenceClass(fqName: FqName): IrClassSymbol?
+    fun referenceTypeAlias(fqName: FqName): IrTypeAliasSymbol?
     fun referenceConstructors(classFqn: FqName): Collection<IrConstructorSymbol>
     fun referenceFunctions(fqName: FqName): Collection<IrSimpleFunctionSymbol>
     fun referenceProperties(fqName: FqName): Collection<IrPropertySymbol>
diff --git a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContextImpl.kt b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContextImpl.kt
index 1717527f1ca..1d0fcd2c8cd 100644
--- a/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContextImpl.kt
+++ b/compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/extensions/IrPluginContextImpl.kt
@@ -85,6 +85,16 @@ open class IrPluginContextImpl(
         }
     }
 
+    override fun referenceTypeAlias(fqName: FqName): IrTypeAliasSymbol? {
+        assert(!fqName.isRoot)
+        return resolveSymbol(fqName.parent()) { scope ->
+            val aliasDescriptor = scope.getContributedClassifier(fqName.shortName(), NoLookupLocation.FROM_BACKEND) as? TypeAliasDescriptor?
+            aliasDescriptor?.let {
+                st.referenceTypeAlias(it)
+            }
+        }
+    }
+
     override fun referenceConstructors(classFqn: FqName): Collection<IrConstructorSymbol> {
         val classSymbol = referenceClass(classFqn) ?: error("Cannot find class $classFqn")
         return classSymbol.owner.declarations.filterIsInstance<IrConstructor>().map { it.symbol }