Generating remove() for Iterator using same mechanism.

compiler/backend/src/org/jetbrains/jet/codegen/ClassBodyCodegen.java

@@ -28,16 +28,12 @@ import org.jetbrains.jet.lang.descriptors.impl.SimpleFunctionDescriptorImpl;
 import org.jetbrains.jet.lang.psi.*;
 import org.jetbrains.jet.lang.resolve.BindingContext;
 import org.jetbrains.jet.lang.resolve.name.Name;
-import org.jetbrains.jet.lang.types.JetType;
-import org.jetbrains.jet.lang.types.TypeUtils;
-import org.jetbrains.jet.lang.types.checker.JetTypeChecker;
-import org.jetbrains.jet.lang.types.lang.KotlinBuiltIns;
 
 import java.util.Collections;
 import java.util.List;
 
-import static org.jetbrains.asm4.Opcodes.*;
-import static org.jetbrains.jet.codegen.AsmUtil.genMethodThrow;
+import static org.jetbrains.asm4.Opcodes.ACC_STATIC;
+import static org.jetbrains.asm4.Opcodes.RETURN;
 import static org.jetbrains.jet.codegen.binding.CodegenBinding.enumEntryNeedSubclass;
 
 public abstract class ClassBodyCodegen extends MemberCodegen {
@@ -75,8 +71,6 @@ public abstract class ClassBodyCodegen extends MemberCodegen {
 
         generateStaticInitializer();
 
-        generateRemoveInIterator();
-
         generateKotlinAnnotation();
     }
 
@@ -196,29 +190,4 @@ public abstract class ClassBodyCodegen extends MemberCodegen {
         }
         return clInitCodegen;
     }
-
-    private void generateRemoveInIterator() {
-        // generates stub 'remove' function for subclasses of Iterator to be compatible with java.util.Iterator
-        if (isIteratorWithoutRemoveImpl(descriptor)) {
-            MethodVisitor mv = v.getVisitor().visitMethod(ACC_PUBLIC, "remove", "()V", null, null);
-            genMethodThrow(mv, "java/lang/UnsupportedOperationException", "Mutating method called on a Kotlin Iterator");
-        }
-    }
-
-    private static boolean isIteratorWithoutRemoveImpl(@NotNull ClassDescriptor classDescriptor) {
-        ClassDescriptor iteratorOfT = KotlinBuiltIns.getInstance().getIterator();
-        JetType iteratorOfAny =
-                TypeUtils.substituteParameters(iteratorOfT, Collections.singletonList(KotlinBuiltIns.getInstance().getAnyType()));
-        if (!JetTypeChecker.INSTANCE.isSubtypeOf(classDescriptor.getDefaultType(), iteratorOfAny)) {
-            return false;
-        }
-
-        for (FunctionDescriptor function : classDescriptor.getDefaultType().getMemberScope().getFunctions(Name.identifier("remove"))) {
-            if (function.getValueParameters().isEmpty() && function.getTypeParameters().isEmpty()) {
-                return false;
-            }
-        }
-
-        return true;
-    }
 }

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

@@ -522,6 +522,13 @@ public class ImplementationBodyCodegen extends ClassBodyCodegen {
             }
         }
 
+        if (isSubclass(descriptor, builtIns.getIterator())) {
+            if (CodegenUtil.getDeclaredFunctionByRawSignature(descriptor, Name.identifier("remove"),
+                                                          builtIns.getUnit()) == null) {
+                result.add("remove()V");
+            }
+        }
+
         return result;
     }