001/* 002 * Copyright 2017 The Error Prone Authors. 003 * 004 * Licensed under the Apache License, Version 2.0 (the "License"); 005 * you may not use this file except in compliance with the License. 006 * You may obtain a copy of the License at 007 * 008 * http://www.apache.org/licenses/LICENSE-2.0 009 * 010 * Unless required by applicable law or agreed to in writing, software 011 * distributed under the License is distributed on an "AS IS" BASIS, 012 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. 013 * See the License for the specific language governing permissions and 014 * limitations under the License. 015 */ 016 017package com.google.errorprone.annotations; 018 019import static java.lang.annotation.ElementType.CONSTRUCTOR; 020import static java.lang.annotation.ElementType.METHOD; 021import static java.lang.annotation.ElementType.PACKAGE; 022import static java.lang.annotation.ElementType.TYPE; 023import static java.lang.annotation.RetentionPolicy.SOURCE; 024 025import java.lang.annotation.Documented; 026import java.lang.annotation.Retention; 027import java.lang.annotation.Target; 028 029/** 030 * Indicates that the return value of the annotated method must be checked. An error is triggered 031 * when one of these methods is called but the result is not used. 032 * 033 * <p>{@code @CheckReturnValue} may be applied to a class or package to indicate that all methods in 034 * that class or package must have their return values checked. For convenience, we provide an 035 * annotation, {@link CanIgnoreReturnValue}, to exempt specific methods or classes from this 036 * behavior. 037 */ 038@Documented 039@Target({METHOD, CONSTRUCTOR, TYPE, PACKAGE}) 040@Retention(SOURCE) 041public @interface CheckReturnValue {}