Fix IR generation: temporary variable in 'hashCode()' for data class should be 'var'

compiler/ir/ir.psi2ir/src/org/jetbrains/kotlin/psi2ir/builders/ExpressionHelpers.kt

@@ -48,6 +48,12 @@ fun <T : IrElement> IrStatementsBuilder<T>.defineTemporary(value: IrExpression,
     return temporary.descriptor
 }
 
+fun <T : IrElement> IrStatementsBuilder<T>.defineTemporaryVar(value: IrExpression, nameHint: String? = null): VariableDescriptor {
+    val temporary = scope.createTemporaryVariable(value, nameHint, isMutable = true)
+    +temporary
+    return temporary.descriptor
+}
+
 fun IrBuilderWithScope.irReturn(value: IrExpression) =
         IrReturnImpl(startOffset, endOffset, context.builtIns.nothingType, scope.assertCastOwner(), value)
 

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

@@ -103,7 +103,7 @@ class DataClassMembersGenerator(
 
     override fun generateHashCodeMethod(function: FunctionDescriptor, properties: List<PropertyDescriptor>) {
         buildMember(function) {
-            val result = defineTemporary(irInt(0), "result")
+            val result = defineTemporaryVar(irInt(0), "result")
             var first = true
             for (property in properties) {
                 val hashCodeOfProperty = getHashCodeOfProperty(irThis(), property)

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

@@ -30,18 +30,18 @@ class Scope(val scopeOwner: DeclarationDescriptor) {
     private var lastTemporaryIndex: Int = 0
     private fun nextTemporaryIndex(): Int = lastTemporaryIndex++
 
-    private fun createDescriptorForTemporaryVariable(type: KotlinType, nameHint: String? = null): IrTemporaryVariableDescriptor =
-            IrTemporaryVariableDescriptorImpl(scopeOwner, Name.identifier(getNameForTemporary(nameHint)), type)
+    private fun createDescriptorForTemporaryVariable(type: KotlinType, nameHint: String? = null, isMutable: Boolean = false): IrTemporaryVariableDescriptor =
+            IrTemporaryVariableDescriptorImpl(scopeOwner, Name.identifier(getNameForTemporary(nameHint)), type, isMutable)
 
     private fun getNameForTemporary(nameHint: String?): String {
         val index = nextTemporaryIndex()
         return if (nameHint != null) "tmp${index}_$nameHint" else "tmp$index"
     }
 
-    fun createTemporaryVariable(irExpression: IrExpression, nameHint: String? = null): IrVariable =
+    fun createTemporaryVariable(irExpression: IrExpression, nameHint: String? = null, isMutable: Boolean = false): IrVariable =
             IrVariableImpl(
                     irExpression.startOffset, irExpression.endOffset, IrDeclarationOrigin.IR_TEMPORARY_VARIABLE,
-                    createDescriptorForTemporaryVariable(irExpression.type, nameHint),
+                    createDescriptorForTemporaryVariable(irExpression.type, nameHint, isMutable),
                     irExpression
             )
 }

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/descriptors/IrTemporaryVariableDescriptor.kt

@@ -29,7 +29,8 @@ interface IrTemporaryVariableDescriptor : VariableDescriptor
 class IrTemporaryVariableDescriptorImpl(
         containingDeclaration: DeclarationDescriptor,
         name: Name,
-        outType: KotlinType
+        outType: KotlinType,
+        private val isMutable: Boolean = false
 ): VariableDescriptorImpl(containingDeclaration, Annotations.EMPTY, name, outType, SourceElement.NO_SOURCE),
         IrTemporaryVariableDescriptor
 {
@@ -41,7 +42,7 @@ class IrTemporaryVariableDescriptorImpl(
         throw UnsupportedOperationException("Temporary variable descriptor shouldn't be substituted (so far): $this")
     }
 
-    override fun isVar(): Boolean = false
+    override fun isVar(): Boolean = isMutable
 
     override fun <R, D> accept(visitor: DeclarationDescriptorVisitor<R, D>, data: D): R =
             visitor.visitVariableDescriptor(this, data)

compiler/testData/ir/irText/classes/dataClasses.txt

@@ -72,7 +72,7 @@ FILE /dataClasses.kt
             CONST String type=kotlin.String value=')'
     FUN GENERATED_DATA_CLASS_MEMBER public open override fun hashCode(): kotlin.Int
       BLOCK_BODY
-        VAR IR_TEMPORARY_VARIABLE val tmp0_result: kotlin.Int
+        VAR IR_TEMPORARY_VARIABLE var tmp0_result: kotlin.Int
           CONST Int type=kotlin.Int value='0'
         SET_VAR 'tmp0_result: Int' type=kotlin.Unit origin=EQ
           CALL 'hashCode(): Int' type=kotlin.Int origin=null