Stabilized order of bytecode for when mappings initialization.

compiler/backend/src/org/jetbrains/kotlin/codegen/when/WhenByEnumsMapping.java

@@ -20,14 +20,14 @@ import org.jetbrains.annotations.NotNull;
 import org.jetbrains.kotlin.descriptors.ClassDescriptor;
 import org.jetbrains.kotlin.resolve.constants.EnumValue;
 
-import java.util.HashMap;
+import java.util.LinkedHashMap;
 import java.util.Map;
 
 public class WhenByEnumsMapping {
     private static final String MAPPING_ARRAY_FIELD_PREFIX = "$EnumSwitchMapping$";
     private static final String MAPPINGS_CLASS_NAME_POSTFIX = "$WhenMappings";
 
-    private final Map<EnumValue, Integer> map = new HashMap<EnumValue, Integer>();
+    private final Map<EnumValue, Integer> map = new LinkedHashMap<EnumValue, Integer>();
     private final ClassDescriptor enumClassDescriptor;
     private final String outerClassInternalNameForExpression;
     private final String mappingsClassInternalName;

compiler/tests/org/jetbrains/kotlin/codegen/CustomBytecodeTextTest.kt

@@ -0,0 +1,50 @@
+/*
+ * Copyright 2010-2015 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.kotlin.codegen
+
+import com.intellij.testFramework.UsefulTestCase
+import org.jetbrains.kotlin.test.ConfigurationKind
+
+public class CustomBytecodeTextTest : AbstractBytecodeTextTest() {
+    fun testEnumMapping() {
+        createEnvironmentWithMockJdkAndIdeaAnnotations(ConfigurationKind.ALL)
+        myFiles = CodegenTestFiles.create("whenMappingOrder.kt", """
+        enum class MyEnum {
+            ENTRY1, ENTRY2, ENTRY3, ENTRY4
+        }
+
+        fun f(e: MyEnum) {
+            when (e) {
+                MyEnum.ENTRY4 -> {}
+                MyEnum.ENTRY3 -> {}
+                MyEnum.ENTRY2 -> {}
+                MyEnum.ENTRY1 -> {}
+            }
+        }
+        """, myEnvironment.project)
+
+        val text = generateToText()
+        val getstatics = text.lines().filter { it.contains("GETSTATIC MyEnum.") }.map { it.trim() }
+        UsefulTestCase.assertOrderedEquals("actual bytecode:\n" + text, listOf(
+                "GETSTATIC MyEnum.${'$'}VALUES : [LMyEnum;",
+                "GETSTATIC MyEnum.ENTRY4 : LMyEnum;",
+                "GETSTATIC MyEnum.ENTRY3 : LMyEnum;",
+                "GETSTATIC MyEnum.ENTRY2 : LMyEnum;",
+                "GETSTATIC MyEnum.ENTRY1 : LMyEnum;"
+        ), getstatics)
+    }
+}