Simple diagnostic on 'operator' keyword

compiler/frontend/src/org/jetbrains/kotlin/resolve/OperatorModifierChecker.kt

@@ -0,0 +1,80 @@
+/*
+ * 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.
+ */
+
+/*
+ * 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.resolve
+
+import org.jetbrains.kotlin.descriptors.DeclarationDescriptor
+import org.jetbrains.kotlin.descriptors.FunctionDescriptor
+import org.jetbrains.kotlin.diagnostics.DiagnosticSink
+import org.jetbrains.kotlin.diagnostics.Errors
+import org.jetbrains.kotlin.lexer.JetTokens
+import org.jetbrains.kotlin.name.Name
+import org.jetbrains.kotlin.psi.JetDeclaration
+import org.jetbrains.kotlin.types.expressions.OperatorConventions.*
+
+public class OperatorModifierChecker : DeclarationChecker {
+
+    private companion object {
+        private val GET = Name.identifier("get")
+        private val SET = Name.identifier("set")
+
+        private val COMPONENT_REGEX = "component\\d+".toRegex()
+    }
+
+    override fun check(
+            declaration: JetDeclaration,
+            descriptor: DeclarationDescriptor,
+            diagnosticHolder: DiagnosticSink,
+            bindingContext: BindingContext
+    ) {
+        val functionDescriptor = descriptor as? FunctionDescriptor ?: return
+        if (!functionDescriptor.isOperator) return
+        val modifier = declaration.modifierList?.getModifier(JetTokens.OPERATOR_KEYWORD) ?: return
+
+        val name = functionDescriptor.name
+
+        when {
+            GET == name -> {}
+            SET == name -> {}
+            INVOKE == name -> {}
+            CONTAINS == name -> {}
+            ITERATOR == name -> {}
+            EQUALS == name -> {}
+            COMPARE_TO == name -> {}
+            UNARY_OPERATION_NAMES.any { it.value == name } && functionDescriptor.valueParameters.isEmpty() -> {}
+            BINARY_OPERATION_NAMES.any { it.value == name } && functionDescriptor.valueParameters.size() == 1 -> {}
+            ASSIGNMENT_OPERATIONS.any { it.value == name } -> {}
+            name.asString().matches(COMPONENT_REGEX) -> {}
+            else -> diagnosticHolder.report(Errors.INAPPLICABLE_OPERATOR_MODIFIER.on(modifier))
+        }
+    }
+}

compiler/frontend/src/org/jetbrains/kotlin/resolve/TargetPlatform.kt

@@ -39,7 +39,7 @@ public abstract class TargetPlatform(
     }
 }
 
-private val DEFAULT_DECLARATION_CHECKERS = listOf(DataClassAnnotationChecker(), ConstModifierChecker, UnderscoreChecker)
+private val DEFAULT_DECLARATION_CHECKERS = listOf(DataClassAnnotationChecker(), ConstModifierChecker, UnderscoreChecker, OperatorModifierChecker())
 private val DEFAULT_CALL_CHECKERS = listOf(CapturingInClosureChecker(), InlineCheckerWrapper(), ReifiedTypeParameterSubstitutionChecker())
 private val DEFAULT_TYPE_CHECKERS = emptyList<AdditionalTypeChecker>()
 private val DEFAULT_VALIDATORS = listOf(DeprecatedSymbolValidator(), AccessToPrivateTopLevelSymbolValidator(), OperatorValidator())

compiler/frontend/src/org/jetbrains/kotlin/types/expressions/OperatorConventions.java

@@ -32,6 +32,7 @@ public class OperatorConventions {
     public static final Name COMPARE_TO = Name.identifier("compareTo");
     public static final Name CONTAINS = Name.identifier("contains");
     public static final Name INVOKE = Name.identifier("invoke");
+    public static final Name ITERATOR = Name.identifier("iterator");
 
     private OperatorConventions() {}
 

compiler/testData/diagnostics/tests/OperatorsWithWrongNames.kt

@@ -0,0 +1,11 @@
+class A {
+    operator fun A.minus(o: A) = o
+
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun A.add(o: A) = o
+    operator fun A.get(o: A) = o
+    <!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun A.invokee() {}
+}
+
+operator fun A.plus(o: A) = o
+operator fun A.component1() = 1
+<!INAPPLICABLE_OPERATOR_MODIFIER!>operator<!> fun A.componentN() = 1

compiler/testData/diagnostics/tests/OperatorsWithWrongNames.txt

@@ -0,0 +1,16 @@
+package
+
+public operator fun A.component1(): kotlin.Int
+public operator fun A.componentN(): kotlin.Int
+public operator fun A.plus(/*0*/ o: A): A
+
+public final class A {
+    public constructor A()
+    public open override /*1*/ /*fake_override*/ fun equals(/*0*/ other: kotlin.Any?): kotlin.Boolean
+    public open override /*1*/ /*fake_override*/ fun hashCode(): kotlin.Int
+    public open override /*1*/ /*fake_override*/ fun toString(): kotlin.String
+    public final operator fun A.add(/*0*/ o: A): A
+    public final operator fun A.get(/*0*/ o: A): A
+    public final operator fun A.invokee(): kotlin.Unit
+    public final operator fun A.minus(/*0*/ o: A): A
+}

compiler/tests/org/jetbrains/kotlin/checkers/JetDiagnosticsTestGenerated.java

@@ -343,6 +343,12 @@ public class JetDiagnosticsTestGenerated extends AbstractJetDiagnosticsTest {
             doTest(fileName);
         }
 
+        @TestMetadata("OperatorsWithWrongNames.kt")
+        public void testOperatorsWithWrongNames() throws Exception {
+            String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/OperatorsWithWrongNames.kt");
+            doTest(fileName);
+        }
+
         @TestMetadata("OverrideFunctionWithParamDefaultValue.kt")
         public void testOverrideFunctionWithParamDefaultValue() throws Exception {
             String fileName = JetTestUtils.navigationMetadata("compiler/testData/diagnostics/tests/OverrideFunctionWithParamDefaultValue.kt");