1 /*

     2  * Copyright (c) 2008, 2013, 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.  Oracle designates this

     8  * particular file as subject to the "Classpath" exception as provided

     9  * by Oracle in the LICENSE file that accompanied this code.

    10  *

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

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

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

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

    15  * accompanied this code).

    16  *

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

    18  * 2 along with this work; if not, write to the Free Software Foundation,

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

    20  *

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

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

    23  * questions.

    24  */

    25 

    26 package com.sun.tools.javac.code;

    27 

    28 import com.sun.tools.javac.util.Assert;

    29 

    30 /**

    31  * Describes the type of program element an extended annotation (or extended

    32  * compound attribute) targets.

    33  *

    34  * By comparison, a Tree.Kind has enum values for all elements in the AST, and

    35  * it does not provide enough resolution for type arguments (i.e., whether an

    36  * annotation targets a type argument in a local variable, method return type,

    37  * or a typecast).

    38  *

    39  *  <p><b>This is NOT part of any supported API.

    40  *  If you write code that depends on this, you do so at your own risk.

    41  *  This code and its internal interfaces are subject to change or

    42  *  deletion without notice.</b>

    43  */

    44 // Code duplicated in com.sun.tools.classfile.TypeAnnotation.TargetType

    45 public enum TargetType {

    46     /** For annotations on a class type parameter declaration. */

    47     CLASS_TYPE_PARAMETER(0x00),

    48 

    49     /** For annotations on a method type parameter declaration. */

    50     METHOD_TYPE_PARAMETER(0x01),

    51 

    52     /** For annotations on the type of an "extends" or "implements" clause. */

    53     CLASS_EXTENDS(0x10),

    54 

    55     /** For annotations on a bound of a type parameter of a class. */

    56     CLASS_TYPE_PARAMETER_BOUND(0x11),

    57 

    58     /** For annotations on a bound of a type parameter of a method. */

    59     METHOD_TYPE_PARAMETER_BOUND(0x12),

    60 

    61     /** For annotations on a field. */

    62     FIELD(0x13),

    63 

    64     /** For annotations on a method return type. */

    65     METHOD_RETURN(0x14),

    66 

    67     /** For annotations on the method receiver. */

    68     METHOD_RECEIVER(0x15),

    69 

    70     /** For annotations on a method parameter. */

    71     METHOD_FORMAL_PARAMETER(0x16),

    72 

    73     /** For annotations on a throws clause in a method declaration. */

    74     THROWS(0x17),

    75 

    76     /** For annotations on a local variable. */

    77     LOCAL_VARIABLE(0x40, true),

    78 

    79     /** For annotations on a resource variable. */

    80     RESOURCE_VARIABLE(0x41, true),

    81 

    82     /** For annotations on an exception parameter. */

    83     EXCEPTION_PARAMETER(0x42, true),

    84 

    85     /** For annotations on a type test. */

    86     INSTANCEOF(0x43, true),

    87 

    88     /** For annotations on an object creation expression. */

    89     NEW(0x44, true),

    90 

    91     /** For annotations on a constructor reference receiver. */

    92     CONSTRUCTOR_REFERENCE(0x45, true),

    93 

    94     /** For annotations on a method reference receiver. */

    95     METHOD_REFERENCE(0x46, true),

    96 

    97     /** For annotations on a typecast. */

    98     CAST(0x47, true),

    99 

   100     /** For annotations on a type argument of an object creation expression. */

   101     CONSTRUCTOR_INVOCATION_TYPE_ARGUMENT(0x48, true),

   102 

   103     /** For annotations on a type argument of a method call. */

   104     METHOD_INVOCATION_TYPE_ARGUMENT(0x49, true),

   105 

   106     /** For annotations on a type argument of a constructor reference. */

   107     CONSTRUCTOR_REFERENCE_TYPE_ARGUMENT(0x4A, true),

   108 

   109     /** For annotations on a type argument of a method reference. */

   110     METHOD_REFERENCE_TYPE_ARGUMENT(0x4B, true);

   111 

   112     private static final int MAXIMUM_TARGET_TYPE_VALUE = 0x4B;

   113 

   114     private final int targetTypeValue;

   115     private final boolean isLocal;

   116 

   117     private TargetType(int targetTypeValue) {

   118         this(targetTypeValue, false);

   119     }

   120 

   121     private TargetType(int targetTypeValue, boolean isLocal) {

   122         if (targetTypeValue < 0

   123                 || targetTypeValue > 255)

   124                 Assert.error("Attribute type value needs to be an unsigned byte: " + String.format("0x%02X", targetTypeValue));

   125         this.targetTypeValue = targetTypeValue;

   126         this.isLocal = isLocal;

   127     }

   128 

   129     /**

   130      * Returns whether or not this TargetType represents an annotation whose

   131      * target is exclusively a tree in a method body

   132      *

   133      * Note: wildcard bound targets could target a local tree and a class

   134      * member declaration signature tree

   135      */

   136     public boolean isLocal() {

   137         return isLocal;

   138     }

   139 

   140     public int targetTypeValue() {

   141         return this.targetTypeValue;

   142     }

   143 

   144     private static final TargetType[] targets;

   145 

   146     static {

   147         targets = new TargetType[MAXIMUM_TARGET_TYPE_VALUE + 1];

   148         TargetType[] alltargets = values();

   149         for (TargetType target : alltargets) {

   150                 targets[target.targetTypeValue] = target;

   151         }

   152     }

   153 

   154     public static boolean isValidTargetTypeValue(int tag) {

   155         return (tag >= 0 && tag < targets.length);

   156     }

   157 

   158     public static TargetType fromTargetTypeValue(int tag) {

   159         if (tag < 0 || tag >= targets.length)

   160             Assert.error("Unknown TargetType: " + tag);

   161         return targets[tag];

   162     }

   163 }