Rework support of Iterator.iterator optimization in ForLoopsLowering

- Fix the predicate used for finding the member function `next`: check
  that there's no extension receiver parameter, don't filter out
  abstract functions.
- Do not copy iterator expression, instead change the type in all
  references to the iterator variable.
- Fix some style issues.

 #KT-47171 Fixed

compiler/fir/fir2ir/tests-gen/org/jetbrains/kotlin/test/runners/codegen/FirBlackBoxCodegenTestGenerated.java

@@ -9335,6 +9335,40 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        public class ForInIterator {
+            @Test
+            @TestMetadata("abstractNext.kt")
+            public void testAbstractNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/abstractNext.kt");
+            }
+
+            @Test
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Test
+            @TestMetadata("primitiveIterator.kt")
+            public void testPrimitiveIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/primitiveIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("uintIterator.kt")
+            public void testUintIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/uintIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("unrelatedExtensionFunctionNext.kt")
+            public void testUnrelatedExtensionFunctionNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/unrelatedExtensionFunctionNext.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
@@ -17266,22 +17300,6 @@ public class FirBlackBoxCodegenTestGenerated extends AbstractFirBlackBoxCodegenT
         }
     }
 
-    @Nested
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    public class ForLoop {
-        @Test
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
-        }
-
-        @Test
-        @TestMetadata("forInIterator.kt")
-        public void testForInIterator() throws Exception {
-            runTest("compiler/testData/codegen/box/forLoop/forInIterator.kt");
-        }
-    }
-
     @Nested
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")

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

@@ -10,20 +10,21 @@ import org.jetbrains.kotlin.backend.common.CommonBackendContext
 import org.jetbrains.kotlin.backend.common.IrElementTransformerVoidWithContext
 import org.jetbrains.kotlin.backend.common.lower.createIrBuilder
 import org.jetbrains.kotlin.backend.common.phaser.makeIrFilePhase
-import org.jetbrains.kotlin.descriptors.Modality
 import org.jetbrains.kotlin.ir.IrElement
 import org.jetbrains.kotlin.ir.IrStatement
-import org.jetbrains.kotlin.ir.builders.irCall
+import org.jetbrains.kotlin.ir.declarations.IrDeclaration
-import org.jetbrains.kotlin.ir.declarations.*
+import org.jetbrains.kotlin.ir.declarations.IrDeclarationOrigin
+import org.jetbrains.kotlin.ir.declarations.IrSymbolOwner
+import org.jetbrains.kotlin.ir.declarations.IrVariable
 import org.jetbrains.kotlin.ir.expressions.*
+import org.jetbrains.kotlin.ir.expressions.impl.IrCallImpl
 import org.jetbrains.kotlin.ir.expressions.impl.IrCompositeImpl
-import org.jetbrains.kotlin.ir.types.classFqName
+import org.jetbrains.kotlin.ir.types.getClass
-import org.jetbrains.kotlin.ir.types.classifierOrFail
+import org.jetbrains.kotlin.ir.types.isStrictSubtypeOfClass
 import org.jetbrains.kotlin.ir.util.*
 import org.jetbrains.kotlin.ir.visitors.*
 import org.jetbrains.kotlin.name.FqName
-import org.jetbrains.kotlin.utils.addToStdlib.cast
+import org.jetbrains.kotlin.util.OperatorNameConventions
-import org.jetbrains.kotlin.utils.addToStdlib.safeAs
 
 val forLoopsPhase = makeIrFilePhase(
     ::ForLoopsLowering,
@@ -305,52 +306,44 @@ private class RangeLoopTransformer(
      *      for (x in iterator)
      *          println(x)
      * ```
-     * Without this optimization, receiver type of call of `next` would be Iterator<T> instead of MyIterator, which
+     * Without this optimization, receiver type of call of `next` would be Iterator<T> instead of MyIterator, which means that
-     * is an unnecessary boxing can be optimized out.
+     * a less specific method would be called, which could lead to unnecessary boxing of primitives or inline classes.
      */
     private fun specializeIteratorIfPossible(irForLoopBlock: IrContainerExpression) {
         val statements = irForLoopBlock.statements
-
         val iterator = statements[0] as IrVariable
-        val loop = statements[1] as IrWhileLoop
 
-        // do optimization iff the initializer is call of `kotlin.collections.CollectionsKt.iterator`
+        val initializer = iterator.initializer as? IrCall ?: return
-        val initializer = iterator.initializer.safeAs<IrCall>().takeIf {
+        if (!initializer.symbol.owner.hasEqualFqName(STDLIB_ITERATOR_FUNCTION_FQ_NAME)) return
-            it != null && it.symbol.owner.fqNameWhenAvailable == FqName("kotlin.collections.CollectionsKt.iterator")
+
+        val receiverType = initializer.extensionReceiver?.type ?: return
+        if (!receiverType.isStrictSubtypeOfClass(context.irBuiltIns.iteratorClass)) return
+
+        val receiverClass = receiverType.getClass() ?: return
+        val next = receiverClass.functions.singleOrNull {
+            it.name == OperatorNameConventions.NEXT &&
+                    it.dispatchReceiverParameter != null &&
+                    it.extensionReceiverParameter == null &&
+                    it.valueParameters.isEmpty()
         } ?: return
 
-        // for now, we only optimize for the case where extension receiver is a direct subclass of `kotlin.collections.Iterator`
-        // we can expand the scope later, if it considered to be necessary
-        val receiverType = initializer.extensionReceiver!!.type.takeIf {
-            it.superTypes().any { superType ->
-                superType.classFqName == FqName("kotlin.collections.Iterator")
-            }
-        } ?: return
-
-        fun IrClass.findNextFunction(): IrFunction? =
-            this.functions.find {
-                it.nameForIrSerialization.asString() == "next"
-                        && it.valueParameters.isEmpty()
-                        && it.modality != Modality.ABSTRACT
-            }
-
-        val next = receiverType.classifierOrFail.owner.cast<IrClass>().findNextFunction() ?: return
-
-        val loopVariable = (loop.body as IrBlock).statements[0] as IrVariable
-        val loopCondition = loop.condition as IrCall
-
         iterator.apply {
-            type = receiverType
+            this.type = receiverType
             this.initializer = initializer.extensionReceiver
         }
 
-        loopCondition.apply {
+        val loop = statements[1] as IrWhileLoop
-            dispatchReceiver = initializer.extensionReceiver!!.shallowCopy()
+        val loopVariable = (loop.body as? IrBlock)?.statements?.firstOrNull() as? IrVariable ?: return
-        }
+        val loopCondition = loop.condition as? IrCall ?: return
+        loopCondition.dispatchReceiver?.type = receiverType
 
-        loopVariable.initializer = with(next) {
+        val nextCall = loopVariable.initializer as? IrCall ?: return
-            context.createIrBuilder(symbol, startOffset, endOffset).irCall(this).apply {
+        loopVariable.initializer = with(nextCall) {
-                dispatchReceiver = initializer.extensionReceiver!!.shallowCopy()
+            IrCallImpl(
+                startOffset, endOffset, type, next.symbol, typeArgumentsCount, valueArgumentsCount, origin, superQualifierSymbol
+            ).apply {
+                copyTypeAndValueArgumentsFrom(nextCall)
+                dispatchReceiver?.type = receiverType
             }
         }
     }
@@ -471,4 +464,8 @@ private class RangeLoopTransformer(
 
         return LoopVariableInfo(mainLoopVariable, mainLoopVariableIndex, loopVariableComponents, loopVariableComponentIndices)
     }
-}
+
+    companion object {
+        val STDLIB_ITERATOR_FUNCTION_FQ_NAME = FqName("kotlin.collections.CollectionsKt.iterator")
+    }
+}

compiler/ir/ir.tree/src/org/jetbrains/kotlin/ir/types/IrTypeUtils.kt

@@ -29,6 +29,9 @@ fun IrClassifierSymbol.isStrictSubtypeOfClass(superClass: IrClassSymbol): Boolea
 fun IrType.isSubtypeOfClass(superClass: IrClassSymbol): Boolean =
     this is IrSimpleType && classifier.isSubtypeOfClass(superClass)
 
+fun IrType.isStrictSubtypeOfClass(superClass: IrClassSymbol): Boolean =
+    this is IrSimpleType && classifier.isStrictSubtypeOfClass(superClass)
+
 fun IrType.isSubtypeOf(superType: IrType, typeSystem: IrTypeSystemContext): Boolean =
     AbstractTypeChecker.isSubtypeOf(createIrTypeCheckerState(typeSystem), this, superType)
 

compiler/testData/codegen/box/controlStructures/forInIterator/abstractNext.kt

@@ -0,0 +1,24 @@
+// TARGET_BACKEND: JVM
+// WITH_STDLIB
+
+fun iterate(iterator: MyIterator): String {
+    for (x in iterator) return x
+    return "Fail"
+}
+
+abstract class MyIterator : Iterator<String> {
+    override fun hasNext(): Boolean = true
+    abstract override fun next(): String
+}
+
+class MyIteratorImpl : MyIterator() {
+    override fun next(): String = "OK"
+}
+
+fun box(): String = iterate(MyIteratorImpl())
+
+// CHECK_BYTECODE_TEXT
+// JVM_IR_TEMPLATES
+// 0 java/util/Iterator.next
+// 1 MyIterator.next
+// 1 MyIteratorImpl.next

compiler/testData/codegen/box/controlStructures/forInIterator/primitiveIterator.kt

@@ -0,0 +1,24 @@
+// TARGET_BACKEND: JVM
+// WITH_STDLIB
+
+fun myFun(iterator: MyLongIterator) {
+    for (x in iterator) {
+        assert(x == 42L)
+    }
+}
+
+class MyLongIterator : Iterator<Long> {
+    private var count = 1
+    override fun hasNext(): Boolean = count-- > 0
+    override fun next(): Long = 42L
+}
+
+fun box(): String {
+    myFun(MyLongIterator())
+    return "OK"
+}
+
+// CHECK_BYTECODE_TEXT
+// JVM_IR_TEMPLATES
+// 0 java/util/Iterator.next
+// 2 MyLongIterator.next

compiler/testData/codegen/box/controlStructures/forInIterator/uintIterator.kt

@@ -1,6 +1,5 @@
 // TARGET_BACKEND: JVM
 // WITH_STDLIB
-// CHECK_BYTECODE_LISTING
 
 fun myFun(iterator: MyUIntIterator) {
     for (x in iterator) {
@@ -25,4 +24,4 @@ fun box(): String {
 // 0 java/util/Iterator.next \(\)Ljava/lang/Object;
 // 1 MyUIntIterator.hasNext \(\)Z
 // 1 public synthetic bridge next\(\)Ljava/lang/Object;
-// 2 MyUIntIterator.next-pVg5ArA \(\)I
+// 2 MyUIntIterator.next-pVg5ArA \(\)I

compiler/testData/codegen/box/controlStructures/forInIterator/unrelatedExtensionFunctionNext.kt

@@ -0,0 +1,22 @@
+// TARGET_BACKEND: JVM
+// WITH_STDLIB
+
+fun iterate(iterator: MyIterator): String {
+    for (x in iterator) return x
+    return "Fail"
+}
+
+class MyIterator : Iterator<String> {
+    @JvmName("unrelated")
+    private fun String.next(): String = throw AssertionError("Should not be called")
+
+    override fun hasNext(): Boolean = true
+    override fun next(): String = "OK"
+}
+
+fun box(): String = iterate(MyIterator())
+
+// CHECK_BYTECODE_TEXT
+// JVM_IR_TEMPLATES
+// 0 java/util/Iterator.next
+// 2 MyIterator.next

compiler/testData/codegen/box/forLoop/forInIterator.txt

@@ -1,17 +0,0 @@
-@kotlin.Metadata
-public final class ForInIteratorKt {
-    // source: 'forInIterator.kt'
-    public final static @org.jetbrains.annotations.NotNull method box(): java.lang.String
-    public final static method myFun(@org.jetbrains.annotations.NotNull p0: MyUIntIterator): void
-}
-
-@kotlin.Metadata
-public final class MyUIntIterator {
-    // source: 'forInIterator.kt'
-    private field count: int
-    public method <init>(): void
-    public method hasNext(): boolean
-    public synthetic bridge method next(): java.lang.Object
-    public method next-pVg5ArA(): int
-    public method remove(): void
-}

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/BlackBoxCodegenTestGenerated.java

@@ -9215,6 +9215,40 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        public class ForInIterator {
+            @Test
+            @TestMetadata("abstractNext.kt")
+            public void testAbstractNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/abstractNext.kt");
+            }
+
+            @Test
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
+            }
+
+            @Test
+            @TestMetadata("primitiveIterator.kt")
+            public void testPrimitiveIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/primitiveIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("uintIterator.kt")
+            public void testUintIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/uintIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("unrelatedExtensionFunctionNext.kt")
+            public void testUnrelatedExtensionFunctionNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/unrelatedExtensionFunctionNext.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
@@ -16846,22 +16880,6 @@ public class BlackBoxCodegenTestGenerated extends AbstractBlackBoxCodegenTest {
         }
     }
 
-    @Nested
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    public class ForLoop {
-        @Test
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
-        }
-
-        @Test
-        @TestMetadata("forInIterator.kt")
-        public void testForInIterator() throws Exception {
-            runTest("compiler/testData/codegen/box/forLoop/forInIterator.kt");
-        }
-    }
-
     @Nested
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")

compiler/tests-common-new/tests-gen/org/jetbrains/kotlin/test/runners/codegen/IrBlackBoxCodegenTestGenerated.java

@@ -9335,6 +9335,40 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        public class ForInIterator {
+            @Test
+            @TestMetadata("abstractNext.kt")
+            public void testAbstractNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/abstractNext.kt");
+            }
+
+            @Test
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
+            }
+
+            @Test
+            @TestMetadata("primitiveIterator.kt")
+            public void testPrimitiveIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/primitiveIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("uintIterator.kt")
+            public void testUintIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/uintIterator.kt");
+            }
+
+            @Test
+            @TestMetadata("unrelatedExtensionFunctionNext.kt")
+            public void testUnrelatedExtensionFunctionNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/unrelatedExtensionFunctionNext.kt");
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
@@ -17266,22 +17300,6 @@ public class IrBlackBoxCodegenTestGenerated extends AbstractIrBlackBoxCodegenTes
         }
     }
 
-    @Nested
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    public class ForLoop {
-        @Test
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM_IR, true);
-        }
-
-        @Test
-        @TestMetadata("forInIterator.kt")
-        public void testForInIterator() throws Exception {
-            runTest("compiler/testData/codegen/box/forLoop/forInIterator.kt");
-        }
-    }
-
     @Nested
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")

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

@@ -7173,6 +7173,39 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class ForInIterator extends AbstractLightAnalysisModeTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM, testDataFilePath);
+            }
+
+            @TestMetadata("abstractNext.kt")
+            public void testAbstractNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/abstractNext.kt");
+            }
+
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
+            }
+
+            @TestMetadata("primitiveIterator.kt")
+            public void testPrimitiveIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/primitiveIterator.kt");
+            }
+
+            @TestMetadata("uintIterator.kt")
+            public void testUintIterator() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/uintIterator.kt");
+            }
+
+            @TestMetadata("unrelatedExtensionFunctionNext.kt")
+            public void testUnrelatedExtensionFunctionNext() throws Exception {
+                runTest("compiler/testData/codegen/box/controlStructures/forInIterator/unrelatedExtensionFunctionNext.kt");
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
@@ -13929,24 +13962,6 @@ public class LightAnalysisModeTestGenerated extends AbstractLightAnalysisModeTes
         }
     }
 
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    @RunWith(JUnit3RunnerWithInners.class)
-    public static class ForLoop extends AbstractLightAnalysisModeTest {
-        private void runTest(String testDataFilePath) throws Exception {
-            KotlinTestUtils.runTest(this::doTest, TargetBackend.JVM, testDataFilePath);
-        }
-
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JVM, true);
-        }
-
-        @TestMetadata("forInIterator.kt")
-        public void testForInIterator() throws Exception {
-            runTest("compiler/testData/codegen/box/forLoop/forInIterator.kt");
-        }
-    }
-
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/JsCodegenBoxTestGenerated.java

@@ -6415,6 +6415,16 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        public class ForInIterator {
+            @Test
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS, true);
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
@@ -13014,16 +13024,6 @@ public class JsCodegenBoxTestGenerated extends AbstractJsCodegenBoxTest {
         }
     }
 
-    @Nested
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    public class ForLoop {
-        @Test
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS, true);
-        }
-    }
-
     @Nested
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")

js/js.tests/tests-gen/org/jetbrains/kotlin/js/test/ir/IrJsCodegenBoxTestGenerated.java

@@ -6457,6 +6457,16 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
             }
         }
 
+        @Nested
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        public class ForInIterator {
+            @Test
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
+            }
+        }
+
         @Nested
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
@@ -13056,16 +13066,6 @@ public class IrJsCodegenBoxTestGenerated extends AbstractIrJsCodegenBoxTest {
         }
     }
 
-    @Nested
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    public class ForLoop {
-        @Test
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.JS_IR, true);
-        }
-    }
-
     @Nested
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")

js/js.tests/tests-gen/org/jetbrains/kotlin/js/testOld/wasm/semantics/IrCodegenBoxWasmTestGenerated.java

@@ -5590,6 +5590,19 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
             }
         }
 
+        @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+        @TestDataPath("$PROJECT_ROOT")
+        @RunWith(JUnit3RunnerWithInners.class)
+        public static class ForInIterator extends AbstractIrCodegenBoxWasmTest {
+            private void runTest(String testDataFilePath) throws Exception {
+                KotlinTestUtils.runTest0(this::doTest, TargetBackend.WASM, testDataFilePath);
+            }
+
+            public void testAllFilesPresentInForInIterator() throws Exception {
+                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
+            }
+        }
+
         @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
         @TestDataPath("$PROJECT_ROOT")
         @RunWith(JUnit3RunnerWithInners.class)
@@ -10891,19 +10904,6 @@ public class IrCodegenBoxWasmTestGenerated extends AbstractIrCodegenBoxWasmTest
         }
     }
 
-    @TestMetadata("compiler/testData/codegen/box/forLoop")
-    @TestDataPath("$PROJECT_ROOT")
-    @RunWith(JUnit3RunnerWithInners.class)
-    public static class ForLoop extends AbstractIrCodegenBoxWasmTest {
-        private void runTest(String testDataFilePath) throws Exception {
-            KotlinTestUtils.runTest0(this::doTest, TargetBackend.WASM, testDataFilePath);
-        }
-
-        public void testAllFilesPresentInForLoop() throws Exception {
-            KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^([^_](.+))\\.kt$"), null, TargetBackend.WASM, true);
-        }
-    }
-
     @TestMetadata("compiler/testData/codegen/box/fullJdk")
     @TestDataPath("$PROJECT_ROOT")
     @RunWith(JUnit3RunnerWithInners.class)

native/native.tests/tests-gen/org/jetbrains/kotlin/konan/blackboxtest/NativeCodegenBoxTestGenerated.java

@@ -7261,6 +7261,18 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
                 }
             }
 
+            @Nested
+            @TestMetadata("compiler/testData/codegen/box/controlStructures/forInIterator")
+            @TestDataPath("$PROJECT_ROOT")
+            @Tag("codegen")
+            @UseExtTestCaseGroupProvider()
+            public class ForInIterator {
+                @Test
+                public void testAllFilesPresentInForInIterator() throws Exception {
+                    KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/controlStructures/forInIterator"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
+                }
+            }
+
             @Nested
             @TestMetadata("compiler/testData/codegen/box/controlStructures/forInSequenceWithIndex")
             @TestDataPath("$PROJECT_ROOT")
@@ -14030,18 +14042,6 @@ public class NativeCodegenBoxTestGenerated extends AbstractNativeCodegenBoxTest
             }
         }
 
-        @Nested
-        @TestMetadata("compiler/testData/codegen/box/forLoop")
-        @TestDataPath("$PROJECT_ROOT")
-        @Tag("codegen")
-        @UseExtTestCaseGroupProvider()
-        public class ForLoop {
-            @Test
-            public void testAllFilesPresentInForLoop() throws Exception {
-                KtTestUtil.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("compiler/testData/codegen/box/forLoop"), Pattern.compile("^(.+)\\.kt$"), null, TargetBackend.NATIVE, true);
-            }
-        }
-
         @Nested
         @TestMetadata("compiler/testData/codegen/box/fullJdk")
         @TestDataPath("$PROJECT_ROOT")