From c92c50aa98766b2ac1acbb99393d9fd75e17fb08 Mon Sep 17 00:00:00 2001
From: Alexander Udalov <Alexander.Udalov@jetbrains.com>
Date: Fri, 8 Feb 2019 16:14:23 +0100
Subject: [PATCH] JVM IR: generate JVM signatures of companion object
 properties

---
 .../backend/jvm/codegen/ClassCodegen.kt       | 35 +++++++++++++++----
 .../backend/jvm/codegen/ExpressionCodegen.kt  |  2 +-
 .../properties/jvmField/interfaceCompanion.kt |  1 -
 3 files changed, 29 insertions(+), 9 deletions(-)

diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
index 06379292ebd..893eefb78f0 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ClassCodegen.kt
@@ -29,6 +29,7 @@ import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.util.dump
 import org.jetbrains.kotlin.ir.util.getPackageFragment
 import org.jetbrains.kotlin.load.java.JavaVisibilities
+import org.jetbrains.kotlin.load.java.JvmAbi
 import org.jetbrains.kotlin.load.kotlin.header.KotlinClassHeader
 import org.jetbrains.kotlin.name.SpecialNames
 import org.jetbrains.kotlin.psi.KtElement
@@ -106,8 +107,22 @@ open class ClassCodegen protected constructor(
         val shortName = File(fileEntry.name).name
         visitor.visitSource(shortName, null)
 
-        irClass.declarations.forEach {
-            generateDeclaration(it)
+        val nestedClasses = irClass.declarations.mapNotNull { declaration ->
+            if (declaration is IrClass) {
+                ClassCodegen(declaration, context, this)
+            } else null
+        }
+
+        val companionObjectCodegen = nestedClasses.firstOrNull { it.irClass.isCompanion }
+
+        for (declaration in irClass.declarations) {
+            generateDeclaration(declaration, companionObjectCodegen)
+        }
+
+        // Generate nested classes at the end, to ensure that codegen for companion object will have the necessary JVM signatures in its
+        // trace for properties moved to the outer class
+        for (codegen in nestedClasses) {
+            codegen.generate()
         }
 
         generateKotlinMetadataAnnotation()
@@ -174,10 +189,10 @@ open class ClassCodegen protected constructor(
         }
     }
 
-    fun generateDeclaration(declaration: IrDeclaration) {
+    private fun generateDeclaration(declaration: IrDeclaration, companionObjectCodegen: ClassCodegen?) {
         when (declaration) {
             is IrField ->
-                generateField(declaration)
+                generateField(declaration, companionObjectCodegen)
             is IrFunction -> {
                 generateMethod(declaration)
             }
@@ -188,14 +203,17 @@ open class ClassCodegen protected constructor(
                 // skip
             }
             is IrClass -> {
-                ClassCodegen(declaration, context, this).generate()
+                // Nested classes are generated separately
             }
             else -> throw RuntimeException("Unsupported declaration $declaration")
         }
     }
 
+    fun generateLocalClass(klass: IrClass) {
+        ClassCodegen(klass, context, this).generate()
+    }
 
-    private fun generateField(field: IrField) {
+    private fun generateField(field: IrField, companionObjectCodegen: ClassCodegen?) {
         if (field.origin == IrDeclarationOrigin.FAKE_OVERRIDE) return
 
         val fieldType = typeMapper.mapType(field.descriptor)
@@ -212,7 +230,10 @@ open class ClassCodegen protected constructor(
 
         val descriptor = field.metadata?.descriptor
         if (descriptor != null) {
-            visitor.serializationBindings.put(JvmSerializationBindings.FIELD_FOR_PROPERTY, descriptor, fieldType to fieldName)
+            val codegen = if (JvmAbi.isPropertyWithBackingFieldInOuterClass(descriptor)) {
+                companionObjectCodegen ?: error("Class with a property moved from the companion must have a companion:\n${irClass.dump()}")
+            } else this
+            codegen.visitor.serializationBindings.put(JvmSerializationBindings.FIELD_FOR_PROPERTY, descriptor, fieldType to fieldName)
         }
     }
 
diff --git a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
index 5411455d8af..46e32d09501 100644
--- a/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
+++ b/compiler/ir/backend.jvm/src/org/jetbrains/kotlin/backend/jvm/codegen/ExpressionCodegen.kt
@@ -557,7 +557,7 @@ class ExpressionCodegen(
     }
 
     override fun visitClass(declaration: IrClass, data: BlockInfo): StackValue {
-        classCodegen.generateDeclaration(declaration)
+        classCodegen.generateLocalClass(declaration)
         return none()
     }
 
diff --git a/compiler/testData/codegen/box/reflection/properties/jvmField/interfaceCompanion.kt b/compiler/testData/codegen/box/reflection/properties/jvmField/interfaceCompanion.kt
index 8159e5ca883..1e99f213aab 100644
--- a/compiler/testData/codegen/box/reflection/properties/jvmField/interfaceCompanion.kt
+++ b/compiler/testData/codegen/box/reflection/properties/jvmField/interfaceCompanion.kt
@@ -1,6 +1,5 @@
 // !LANGUAGE: +JvmFieldInInterface
 // TARGET_BACKEND: JVM
-// IGNORE_BACKEND: JVM_IR
 // WITH_REFLECT
 
 import kotlin.reflect.KProperty1