JVM_IR: do not generate accessors to lateinit private properties

compiler/ir/backend.common/src/org/jetbrains/kotlin/backend/common/CommonBackendContext.kt

@@ -7,10 +7,12 @@ package org.jetbrains.kotlin.backend.common
 
 import org.jetbrains.kotlin.backend.common.ir.Ir
 import org.jetbrains.kotlin.config.CompilerConfiguration
-import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.builders.IrBuilderWithScope
+import org.jetbrains.kotlin.ir.builders.irCall
+import org.jetbrains.kotlin.ir.builders.irString
 import org.jetbrains.kotlin.ir.declarations.IrFile
-import org.jetbrains.kotlin.name.FqName
+import org.jetbrains.kotlin.ir.expressions.IrExpression
 
 interface LoggingContext {
     var inVerbosePhase: Boolean
@@ -24,4 +26,11 @@ interface CommonBackendContext : BackendContext, LoggingContext {
 
     val configuration: CompilerConfiguration
     val scriptMode: Boolean
+
+    fun throwUninitializedPropertyAccessException(builder: IrBuilderWithScope, name: String): IrExpression {
+        val throwErrorFunction = ir.symbols.ThrowUninitializedPropertyAccessException.owner
+        return builder.irCall(throwErrorFunction).apply {
+            putValueArgument(0, builder.irString(name))
+        }
+    }
 }

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

@@ -35,9 +35,9 @@ import org.jetbrains.kotlin.ir.util.resolveFakeOverride
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
 
-open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPass {
+class LateinitLowering(val backendContext: CommonBackendContext) : FileLoweringPass {
 
-    private val nullableFields = context.lateinitNullableFields
+    private val nullableFields = backendContext.lateinitNullableFields
     private fun buildOrGetNullableField(originalField: IrField): IrField {
         if (originalField.type.isMarkedNullable()) return originalField
         return nullableFields.getOrPut(originalField) {
@@ -92,7 +92,7 @@ open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPas
                 ).also {
                     descriptor.bind(it)
                     it.parent = declaration.parent
-                    it.initializer = IrConstImpl.constNull(declaration.startOffset, declaration.endOffset, context.irBuiltIns.nothingNType)
+                    it.initializer = IrConstImpl.constNull(declaration.startOffset, declaration.endOffset, backendContext.irBuiltIns.nothingNType)
                 }
 
                 nullableVariables[declaration] = newVar
@@ -105,7 +105,7 @@ open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPas
                 assert(!type.isPrimitiveType()) { "'lateinit' modifier is not allowed on primitive types" }
                 val startOffset = getter.startOffset
                 val endOffset = getter.endOffset
-                val irBuilder = context.createIrBuilder(getter.symbol, startOffset, endOffset)
+                val irBuilder = backendContext.createIrBuilder(getter.symbol, startOffset, endOffset)
                 irBuilder.run {
                     val body = IrBlockBodyImpl(startOffset, endOffset)
                     val resultVar = scope.createTemporaryVariable(
@@ -117,7 +117,7 @@ open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPas
                         context.irBuiltIns.nothingType,
                         irNotEquals(irGet(resultVar), irNull()),
                         irReturn(irGet(resultVar)),
-                        throwUninitializedPropertyAccessException(this, backingField.name.asString())
+                        backendContext.throwUninitializedPropertyAccessException(this, backingField.name.asString())
                     )
                     body.statements.add(throwIfNull)
                     getter.body = body
@@ -131,12 +131,12 @@ open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPas
                 val irVar = nullableVariables[expression.symbol.owner] ?: return expression
 
                 val parent = irVar.parent as IrSymbolOwner
-                val irBuilder = context.createIrBuilder(parent.symbol, expression.startOffset, expression.endOffset)
+                val irBuilder = backendContext.createIrBuilder(parent.symbol, expression.startOffset, expression.endOffset)
 
                 return irBuilder.run {
                     irIfThenElse(
                         expression.type, irEqualsNull(irGet(irVar)),
-                        throwUninitializedPropertyAccessException(this, irVar.name.asString()),
+                        backendContext.throwUninitializedPropertyAccessException(this, irVar.name.asString()),
                         irGet(irVar)
                     )
                 }
@@ -179,17 +179,10 @@ open class LateinitLowering(val context: CommonBackendContext) : FileLoweringPas
                 val nullableField =
                     buildOrGetNullableField(property.backingField ?: error("Lateinit property is supposed to have backing field"))
 
-                return expression.run { context.createIrBuilder(symbol, startOffset, endOffset) }.run {
+                return expression.run { backendContext.createIrBuilder(symbol, startOffset, endOffset) }.run {
                     irNotEquals(irGetField(receiver.dispatchReceiver, nullableField), irNull())
                 }
             }
         })
     }
-
-    open fun throwUninitializedPropertyAccessException(builder: IrBuilderWithScope, name: String): IrExpression =
-        builder.irCall(throwErrorFunction).apply {
-            putValueArgument(0, builder.irString(name))
-        }
-
-    private val throwErrorFunction by lazy { context.ir.symbols.ThrowUninitializedPropertyAccessException.owner }
 }

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

@@ -7,6 +7,7 @@ package org.jetbrains.kotlin.backend.jvm
 
 import org.jetbrains.kotlin.backend.common.CommonBackendContext
 import org.jetbrains.kotlin.backend.common.ir.Ir
+import org.jetbrains.kotlin.backend.common.lower.irThrow
 import org.jetbrains.kotlin.backend.common.phaser.PhaseConfig
 import org.jetbrains.kotlin.backend.jvm.codegen.IrTypeMapper
 import org.jetbrains.kotlin.backend.jvm.codegen.MethodSignatureMapper
@@ -24,6 +25,9 @@ import org.jetbrains.kotlin.descriptors.ClassDescriptor
 import org.jetbrains.kotlin.descriptors.FunctionDescriptor
 import org.jetbrains.kotlin.descriptors.TypeParameterDescriptor
 import org.jetbrains.kotlin.ir.IrElement
+import org.jetbrains.kotlin.ir.builders.IrBuilderWithScope
+import org.jetbrains.kotlin.ir.builders.irBlock
+import org.jetbrains.kotlin.ir.builders.irNull
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.descriptors.IrBuiltIns
 import org.jetbrains.kotlin.ir.expressions.IrExpression
@@ -136,6 +140,12 @@ class JvmBackendContext(
         print(message)
     }
 
+    override fun throwUninitializedPropertyAccessException(builder: IrBuilderWithScope, name: String): IrExpression =
+        builder.irBlock {
+            +super.throwUninitializedPropertyAccessException(builder, name)
+            +irThrow(irNull())
+        }
+
     inner class JvmIr(
         irModuleFragment: IrModuleFragment,
         symbolTable: ReferenceSymbolTable

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

@@ -14,11 +14,7 @@ import org.jetbrains.kotlin.config.LanguageFeature
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.descriptors.Visibility
 import org.jetbrains.kotlin.ir.IrElement
-import org.jetbrains.kotlin.ir.builders.IrBuilderWithScope
-import org.jetbrains.kotlin.ir.builders.irBlock
-import org.jetbrains.kotlin.ir.builders.irNull
 import org.jetbrains.kotlin.ir.declarations.*
-import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.util.PatchDeclarationParentsVisitor
 import org.jetbrains.kotlin.ir.visitors.IrElementVisitorVoid
 import org.jetbrains.kotlin.ir.visitors.acceptChildrenVoid
@@ -82,15 +78,7 @@ private val expectDeclarationsRemovingPhase = makeIrModulePhase(
 )
 
 private val lateinitPhase = makeIrFilePhase(
-    { backend: JvmBackendContext ->
+    ::LateinitLowering,
-        object : LateinitLowering(backend) {
-            override fun throwUninitializedPropertyAccessException(builder: IrBuilderWithScope, name: String): IrExpression =
-                builder.irBlock {
-                    +super.throwUninitializedPropertyAccessException(builder, name)
-                    +irThrow(irNull())
-                }
-        }
-    },
     name = "Lateinit",
     description = "Insert checks for lateinit field references"
 )

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

@@ -13,12 +13,14 @@ import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
 import org.jetbrains.kotlin.descriptors.ClassKind
 import org.jetbrains.kotlin.descriptors.Visibilities
 import org.jetbrains.kotlin.ir.IrStatement
+import org.jetbrains.kotlin.ir.builders.*
 import org.jetbrains.kotlin.ir.declarations.*
 import org.jetbrains.kotlin.ir.expressions.IrCall
 import org.jetbrains.kotlin.ir.expressions.IrExpression
 import org.jetbrains.kotlin.ir.expressions.IrFieldAccessExpression
 import org.jetbrains.kotlin.ir.expressions.IrTypeOperator
 import org.jetbrains.kotlin.ir.expressions.impl.*
+import org.jetbrains.kotlin.ir.types.makeNotNull
 import org.jetbrains.kotlin.ir.util.hasAnnotation
 import org.jetbrains.kotlin.ir.visitors.IrElementTransformerVoid
 import org.jetbrains.kotlin.ir.visitors.transformChildrenVoid
@@ -63,9 +65,6 @@ class PropertiesToFieldsLowering(val context: CommonBackendContext) : IrElementT
     private fun shouldSubstituteAccessorWithField(property: IrProperty, accessor: IrSimpleFunction?): Boolean {
         if (accessor == null) return false
 
-        // In contrast to the old backend, we do generate getters for lateinit properties, which fixes KT-28331
-        if (property.isLateinit) return false
-
         if ((property.parent as? IrClass)?.kind == ClassKind.ANNOTATION_CLASS) return false
 
         if (property.backingField?.hasAnnotation(JVM_FIELD_ANNOTATION_FQ_NAME) == true) return true
@@ -96,12 +95,34 @@ class PropertiesToFieldsLowering(val context: CommonBackendContext) : IrElementT
             expression.startOffset,
             expression.endOffset,
             backingField.symbol,
-            expression.type,
+            backingField.type,
             receiver,
             expression.origin,
             expression.superQualifierSymbol
         )
-        return buildSubstitution(backingField.isStatic, getExpr, receiver)
+        val substitution = buildSubstitution(backingField.isStatic, getExpr, receiver)
+        return if (irProperty.isLateinit)
+            insertLateinitCheck(substitution, backingField)
+        else
+            substitution
+    }
+
+    private fun insertLateinitCheck(expression: IrExpression, field: IrField): IrExpression {
+        val backendContext = context
+        val startOffset = expression.startOffset
+        val endOffset = expression.endOffset
+        val irBuilder = context.createIrBuilder(field.symbol, startOffset, endOffset)
+        irBuilder.run {
+            return irBlock(expression) {
+                val tmpVar = irTemporaryVar(expression)
+                +irIfThenElse(
+                    expression.type.makeNotNull(),
+                    irEqualsNull(irGet(tmpVar)),
+                    backendContext.throwUninitializedPropertyAccessException(this, field.name.asString()),
+                    irGet(expression.type.makeNotNull(), tmpVar.symbol)
+                )
+            }
+        }
     }
 
     private fun buildSubstitution(needBlock: Boolean, setOrGetExpr: IrFieldAccessExpression, receiver: IrExpression?): IrExpression {

compiler/testData/codegen/box/annotations/annotationsOnLateinitAccessors.kt

@@ -1,6 +1,5 @@
 // IGNORE_BACKEND_FIR: JVM_IR
 // WITH_REFLECT
-// IGNORE_BACKEND: JVM_IR
 // TARGET_BACKEND: JVM
 
 // Please make sure that this test is consistent with the diagnostic test "annotationsTargetingLateinitAccessor.kt"

compiler/testData/codegen/box/properties/lateinit/nameClash.kt

@@ -0,0 +1,17 @@
+// IGNORE_BACKEND_FIR: JVM_IR
+
+class SS {
+    private lateinit var s: String
+
+    fun setS(s: String) {
+        this.s = s
+    }
+
+    fun getS() = s
+}
+
+fun box(): String {
+    val ss = SS()
+    ss.setS("OK")
+    return ss.getS()
+}

compiler/tests/org/jetbrains/kotlin/codegen/BlackBoxCodegenTestGenerated.java

@@ -19169,6 +19169,11 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");

compiler/tests/org/jetbrains/kotlin/codegen/LightAnalysisModeTestGenerated.java

@@ -19169,6 +19169,11 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/FirBlackBoxCodegenTestGenerated.java

@@ -17704,6 +17704,11 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");

compiler/tests/org/jetbrains/kotlin/codegen/ir/IrBlackBoxCodegenTestGenerated.java

@@ -17704,6 +17704,11 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/ir/semantics/IrJsCodegenBoxTestGenerated.java

@@ -14874,6 +14874,11 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");

js/js.tests/test/org/jetbrains/kotlin/js/test/semantics/JsCodegenBoxTestGenerated.java

@@ -16049,6 +16049,11 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
                 runTest("compiler/testData/codegen/box/properties/lateinit/exceptionGetter.kt");
             }
 
+            @TestMetadata("nameClash.kt")
+            public void testNameClash() throws Exception {
+                runTest("compiler/testData/codegen/box/properties/lateinit/nameClash.kt");
+            }
+
             @TestMetadata("override.kt")
             public void testOverride() throws Exception {
                 runTest("compiler/testData/codegen/box/properties/lateinit/override.kt");