Avoid generation of redundant toArray stubs

#KT-13698 In Progress

compiler/backend/src/org/jetbrains/kotlin/codegen/ImplementationBodyCodegen.java

@@ -40,6 +40,7 @@ import org.jetbrains.kotlin.descriptors.*;
 import org.jetbrains.kotlin.incremental.components.NoLookupLocation;
 import org.jetbrains.kotlin.lexer.KtTokens;
 import org.jetbrains.kotlin.load.java.JvmAbi;
+import org.jetbrains.kotlin.load.java.descriptors.JavaClassDescriptor;
 import org.jetbrains.kotlin.name.FqName;
 import org.jetbrains.kotlin.name.Name;
 import org.jetbrains.kotlin.psi.*;
@@ -430,9 +431,16 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
     private void generateToArray() {
         if (descriptor.getKind() == ClassKind.INTERFACE) return;
 
-        KotlinBuiltIns builtIns = DescriptorUtilsKt.getBuiltIns(descriptor);
+        final KotlinBuiltIns builtIns = DescriptorUtilsKt.getBuiltIns(descriptor);
         if (!isSubclass(descriptor, builtIns.getCollection())) return;
 
+        if (CollectionsKt.any(DescriptorUtilsKt.getAllSuperclassesWithoutAny(descriptor), new Function1<ClassDescriptor, Boolean>() {
+            @Override
+            public Boolean invoke(ClassDescriptor classDescriptor) {
+                return !(classDescriptor instanceof JavaClassDescriptor) && isSubclass(classDescriptor, builtIns.getCollection());
+            }
+        })) return;
+
         Collection<SimpleFunctionDescriptor> functions = descriptor.getDefaultType().getMemberScope().getContributedFunctions(
                 Name.identifier("toArray"), NoLookupLocation.FROM_BACKEND
         );

compiler/testData/codegen/bytecodeListing/collectionStubs/noStubsInJavaSuperClass.txt

@@ -30,8 +30,6 @@ public final class test/C {
     public method remove(p0: int): java.lang.Object
     public method set(p0: int, p1: java.lang.Object): java.lang.Object
     public @org.jetbrains.annotations.NotNull method subList(p0: int, p1: int): java.util.List
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }
 
 @kotlin.Metadata

compiler/testData/codegen/bytecodeListing/collectionStubs/stubsFromSuperclass.txt

@@ -20,8 +20,6 @@ public class A {
 @kotlin.Metadata
 public class B {
     public method <init>(): void
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }
 
 @kotlin.Metadata
@@ -37,6 +35,4 @@ public final class C {
     public method remove(p0: int): java.lang.Object
     public method set(p0: int, p1: java.lang.Object): java.lang.Object
     public @org.jetbrains.annotations.NotNull method subList(p0: int, p1: int): java.util.List
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }

compiler/testData/codegen/bytecodeListing/collectionStubs/stubsFromSuperclassNoBridges.txt

@@ -22,8 +22,6 @@ public class B {
     public method <init>(): void
     public method contains(p0: java.lang.CharSequence): boolean
     public final method contains(p0: java.lang.Object): boolean
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }
 
 @kotlin.Metadata
@@ -45,6 +43,4 @@ public final class C {
     public method set(p0: int, p1: java.lang.CharSequence): java.lang.CharSequence
     public synthetic method set(p0: int, p1: java.lang.Object): java.lang.Object
     public @org.jetbrains.annotations.NotNull method subList(p0: int, p1: int): java.util.List
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }

compiler/testData/codegen/bytecodeListing/noToArrayInJava.kt

@@ -0,0 +1,14 @@
+// FILE: test/JavaClass.java
+package test;
+
+public abstract class JavaClass<T> implements A<T> {
+
+}
+
+// FILE: main.kt
+package test
+
+interface A<T> : Collection<T>
+
+// There must be toArray methods in B
+abstract class B<E> : JavaClass<E>()

compiler/testData/codegen/bytecodeListing/noToArrayInJava.txt

@@ -0,0 +1,19 @@
+@kotlin.Metadata
+public interface test/A
+
+@kotlin.Metadata
+public abstract class test/B {
+    public method <init>(): void
+    public method add(p0: java.lang.Object): boolean
+    public method addAll(p0: java.util.Collection): boolean
+    public method clear(): void
+    public abstract method contains(p0: java.lang.Object): boolean
+    public abstract method getSize(): int
+    public method iterator(): java.util.Iterator
+    public method remove(p0: java.lang.Object): boolean
+    public method removeAll(p0: java.util.Collection): boolean
+    public method retainAll(p0: java.util.Collection): boolean
+    public final method size(): int
+    public method toArray(): java.lang.Object[]
+    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
+}

compiler/testData/codegen/bytecodeListing/specialBridges/removeAtTwoSpecialBridges.txt

@@ -42,8 +42,6 @@ public final class A1 {
     public method remove(p0: java.lang.String): boolean
     public synthetic method removeAt(p0: int): java.lang.Object
     public @org.jetbrains.annotations.NotNull method removeAt(p0: int): java.lang.String
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }
 
 @kotlin.Metadata
@@ -59,6 +57,4 @@ public final class A2 {
     public final method remove(p0: java.lang.Object): boolean
     public method remove(p0: java.lang.String): boolean
     public method removeAt(p0: int): java.lang.String
-    public method toArray(): java.lang.Object[]
-    public method toArray(p0: java.lang.Object[]): java.lang.Object[]
 }

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

@@ -89,6 +89,12 @@ public class BytecodeListingTestGenerated extends AbstractBytecodeListingTest {
         doTest(fileName);
     }
 
+    @TestMetadata("noToArrayInJava.kt")
+    public void testNoToArrayInJava() throws Exception {
+        String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeListing/noToArrayInJava.kt");
+        doTest(fileName);
+    }
+
     @TestMetadata("samAdapterAndInlinedOne.kt")
     public void testSamAdapterAndInlinedOne() throws Exception {
         String fileName = KotlinTestUtils.navigationMetadata("compiler/testData/codegen/bytecodeListing/samAdapterAndInlinedOne.kt");