1 /*

     2  * Copyright (c) 2019, Oracle and/or its affiliates. All rights reserved.

     3  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

     4  *

     5  * This code is free software; you can redistribute it and/or modify it

     6  * under the terms of the GNU General Public License version 2 only, as

     7  * published by the Free Software Foundation.

     8  *

     9  * This code is distributed in the hope that it will be useful, but WITHOUT

    10  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

    11  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

    12  * version 2 for more details (a copy is included in the LICENSE file that

    13  * accompanied this code).

    14  *

    15  * You should have received a copy of the GNU General Public License version

    16  * 2 along with this work; if not, write to the Free Software Foundation,

    17  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

    18  *

    19  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

    20  * or visit www.oracle.com if you need additional information or have any

    21  * questions.

    22  */

    23 

    24 /*

    25  * @test

    26  * @bug 8223305 8226522

    27  * @summary Verify correct warnings w.r.t. yield

    28  * @compile/ref=WarnWrongYieldTest.out -source ${jdk.version} -XDrawDiagnostics -XDshould-stop.at=ATTR WarnWrongYieldTest.java

    29  */

    30 

    31 package t;

    32 

    33 //ERROR - type called yield:

    34 import t.WarnWrongYieldTest.yield;

    35 

    36 public class WarnWrongYieldTest {

    37 

    38     // ERROR -  class called yield

    39     class yield { }

    40 

    41     // OK to have fields called yield

    42     String[] yield = null;

    43 

    44     // ERROR - field of type yield

    45     yield y;

    46 

    47     // OK to have methods called yield

    48     // Nullary yield method

    49     String[] yield() {

    50         return null;

    51     }

    52     // Unary yield method

    53     String[] yield(int i) {

    54         return null;

    55     }

    56     // Binary yield method

    57     String[] yield(int i, int j) {

    58         return null;

    59     }

    60 

    61     // OK to declare a local called yield

    62     void LocalDeclaration1() {

    63        int yield;

    64     }

    65     // OK to declare and initialise a local called yield

    66     void LocalDeclaration2() {

    67         int yield = 42;

    68     }

    69 

    70     void YieldTypedLocals(int i) {

    71         // ERROR - Parsed as yield statement, and y1 is unknown

    72         yield y1 = null;

    73 

    74         // ERROR - Parsed as yield statement, and y2 is unknown

    75         yield y2 = new yield();

    76 

    77         // ERROR - can not create an yield-valued local of type Object

    78         Object y3 = new yield();

    79 

    80         // ERROR - can not create a final yield-valued local of type yield

    81         final yield y4 = new yield();

    82 

    83         // ERROR - can create a non-final local of type yield using qualified typename

    84         WarnWrongYieldTest.yield y5 = new yield();

    85     }

    86 

    87     void MethodInvocation(int i) {

    88 

    89         // OK - can access a field called yield

    90         String[] x = this.yield;

    91 

    92         // ERROR - calling nullary yield method using simple name parsed as yield statement

    93         yield();

    94         // OK - can call nullary yield method using qualified name

    95         this.yield();

    96 

    97         // ERROR - Calling unary yield method using simple name is parsed as yield statement

    98         yield(2);

    99         // OK - calling unary yield method using qualified name

   100         this.yield(2);

   101 

   102         // ERROR - Calling binary yield method using simple name is parsed as yield statement

   103         yield(2, 2); //error

   104         // OK - calling binary yield method using qualified name

   105         this.yield(2, 2);

   106 

   107         // ERROR - nullary yield method as receiver is parsed as yield statement

   108         yield().toString();

   109         // OK - nullary yield method as receiver using qualified name

   110         this.yield().toString();

   111 

   112         // ERROR - unary yield method as receiver is parsed as yield statement

   113         yield(2).toString();

   114         // OK - unary yield method as receiver using qualified name

   115         this.yield(2).toString();

   116 

   117         // ERROR - binary yield method as receiver is parsed as yield statement

   118         yield(2, 2).toString();

   119         // OK - binary yield method as receiver using qualified name

   120         this.yield(2, 2).toString();

   121 

   122         // OK - yield method call is in an expression position

   123         String str = yield(2).toString();

   124 

   125         //OK - yield is a variable

   126         yield.toString();

   127 

   128         // OK - parsed as method call (with qualified local yield as receiver)

   129         this.yield.toString();

   130 

   131         yield[0].toString(); //error

   132     }

   133 

   134     private void yieldLocalVar1(int i) {

   135         int yield = 0;

   136 

   137         //OK - yield is a variable:

   138         yield++;

   139         yield--;

   140 

   141         //OK - yield is a variable:

   142         yield = 3;

   143 

   144         //OK - yield is a variable:

   145         for (int j = 0; j < 3; j++)

   146             yield += 1;

   147 

   148         //OK - yield is a variable and not at the beginning of the statement:

   149         yieldLocalVar1(yield);

   150 

   151         //ERROR - unqualified yield method invocation:

   152         yieldLocalVar1(yield().length);

   153         yieldLocalVar1(yield.class.getModifiers());

   154     }

   155 

   156     private void yieldLocalVar2(int i) {

   157         int[] yield = new int[1];

   158 

   159         //OK - yield is a variable:

   160         yield[0] = 5;

   161     }

   162 

   163     private void lambda() {

   164         SAM s = (yield y) -> {};

   165     }

   166 

   167     interface SAM {

   168         public void m(yield o);

   169     }

   170 }