1 /*

     2  * Copyright (c) 2005, 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 package com.sun.tools.javac.code;

    26 

    27 import java.lang.annotation.Annotation;

    28 import java.lang.reflect.InvocationTargetException;

    29 import java.lang.reflect.Method;

    30 

    31 import javax.lang.model.AnnotatedConstruct;

    32 

    33 import com.sun.tools.javac.model.AnnotationProxyMaker;

    34 import com.sun.tools.javac.util.List;

    35 import com.sun.tools.javac.util.ListBuffer;

    36 

    37 /**

    38  * Common super type for annotated constructs such as Types and Symbols.

    39  *

    40  * This class should *not* contain any fields since it would have a significant

    41  * impact on the javac memory footprint.

    42  *

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

    44  * If you write code that depends on this, you do so at your own

    45  * risk.  This code and its internal interfaces are subject to change

    46  * or deletion without notice.</b></p>

    47  */

    48 public abstract class AnnoConstruct implements AnnotatedConstruct {

    49 

    50 

    51     // Override to enforce a narrower return type.

    52     @Override

    53     public abstract List<? extends Attribute.Compound> getAnnotationMirrors();

    54 

    55 

    56     // This method is part of the javax.lang.model API, do not use this in javac code.

    57     protected <A extends Annotation> Attribute.Compound getAttribute(Class<A> annoType) {

    58         String name = annoType.getName();

    59 

    60         for (Attribute.Compound anno : getAnnotationMirrors()) {

    61             if (name.equals(anno.type.tsym.flatName().toString()))

    62                 return anno;

    63         }

    64 

    65         return null;

    66     }

    67 

    68 

    69     @SuppressWarnings("unchecked")

    70     protected <A extends Annotation> A[] getInheritedAnnotations(Class<A> annoType) {

    71         return (A[]) java.lang.reflect.Array.newInstance(annoType, 0);  // annoType is the Class for A

    72     }

    73 

    74 

    75     // This method is part of the javax.lang.model API, do not use this in javac code.

    76     public <A extends Annotation> A[] getAnnotationsByType(Class<A> annoType) {

    77 

    78         if (!annoType.isAnnotation())

    79             throw new IllegalArgumentException("Not an annotation type: "

    80                                                + annoType);

    81         // If annoType does not declare a container this is equivalent to wrapping

    82         // getAnnotation(...) in an array.

    83         Class <? extends Annotation> containerType = getContainer(annoType);

    84         if (containerType == null) {

    85             A res = getAnnotation(annoType);

    86             int size = res == null ? 0 : 1;

    87 

    88             @SuppressWarnings("unchecked") // annoType is the Class for A

    89             A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);

    90             if (res != null)

    91                 arr[0] = res;

    92             return arr;

    93         }

    94 

    95         // So we have a containing type

    96         String annoTypeName = annoType.getName();

    97         String containerTypeName = containerType.getName();

    98         int directIndex = -1, containerIndex = -1;

    99         Attribute.Compound direct = null, container = null;

   100         // Find directly (explicit or implicit) present annotations

   101         int index = -1;

   102         for (Attribute.Compound attribute : getAnnotationMirrors()) {

   103             index++;

   104             if (attribute.type.tsym.flatName().contentEquals(annoTypeName)) {

   105                 directIndex = index;

   106                 direct = attribute;

   107             } else if(containerTypeName != null &&

   108                       attribute.type.tsym.flatName().contentEquals(containerTypeName)) {

   109                 containerIndex = index;

   110                 container = attribute;

   111             }

   112         }

   113 

   114         // Deal with inherited annotations

   115         if (direct == null && container == null)

   116             return getInheritedAnnotations(annoType);

   117 

   118         // Pack them in an array

   119         Attribute[] contained0 = null;

   120         if (container != null)

   121             contained0 = unpackAttributes(container);

   122         ListBuffer<Attribute.Compound> compounds = new ListBuffer<>();

   123         if (contained0 != null) {

   124             for (Attribute a : contained0)

   125                 if (a instanceof Attribute.Compound)

   126                     compounds = compounds.append((Attribute.Compound)a);

   127         }

   128         Attribute.Compound[] contained = compounds.toArray(new Attribute.Compound[compounds.size()]);

   129 

   130         int size = (direct == null ? 0 : 1) + contained.length;

   131         @SuppressWarnings("unchecked") // annoType is the Class for A

   132         A[] arr = (A[])java.lang.reflect.Array.newInstance(annoType, size);

   133 

   134         // if direct && container, which is first?

   135         int insert = -1;

   136         int length = arr.length;

   137         if (directIndex >= 0 && containerIndex >= 0) {

   138             if (directIndex < containerIndex) {

   139                 arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);

   140                 insert = 1;

   141             } else {

   142                 arr[arr.length - 1] = AnnotationProxyMaker.generateAnnotation(direct, annoType);

   143                 insert = 0;

   144                 length--;

   145             }

   146         } else if (directIndex >= 0) {

   147             arr[0] = AnnotationProxyMaker.generateAnnotation(direct, annoType);

   148             return arr;

   149         } else {

   150             // Only container

   151             insert = 0;

   152         }

   153 

   154         for (int i = 0; i + insert < length; i++)

   155             arr[insert + i] = AnnotationProxyMaker.generateAnnotation(contained[i], annoType);

   156 

   157         return arr;

   158     }

   159 

   160 

   161     // This method is part of the javax.lang.model API, do not use this in javac code.

   162     public <A extends Annotation> A getAnnotation(Class<A> annoType) {

   163 

   164         if (!annoType.isAnnotation())

   165             throw new IllegalArgumentException("Not an annotation type: " + annoType);

   166 

   167         Attribute.Compound c = getAttribute(annoType);

   168         return c == null ? null : AnnotationProxyMaker.generateAnnotation(c, annoType);

   169     }

   170 

   171     // Needed to unpack the runtime view of containing annotations

   172     private static final Class<? extends Annotation> REPEATABLE_CLASS = initRepeatable();

   173     private static final Method VALUE_ELEMENT_METHOD = initValueElementMethod();

   174 

   175     private static Class<? extends Annotation> initRepeatable() {

   176         try {

   177             // Repeatable will not be available when bootstrapping on

   178             // JDK 7 so use a reflective lookup instead of a class

   179             // literal for Repeatable.class.

   180             return Class.forName("java.lang.annotation.Repeatable").asSubclass(Annotation.class);

   181         } catch (ClassNotFoundException | SecurityException e) {

   182             return null;

   183         }

   184     }

   185 

   186     private static Method initValueElementMethod() {

   187         if (REPEATABLE_CLASS == null)

   188             return null;

   189 

   190         Method m = null;

   191         try {

   192             m = REPEATABLE_CLASS.getMethod("value");

   193             if (m != null)

   194                 m.setAccessible(true);

   195             return m;

   196         } catch (NoSuchMethodException e) {

   197             return null;

   198         }

   199     }

   200 

   201 

   202     // Helper to getAnnotationsByType

   203     private static Class<? extends Annotation> getContainer(Class<? extends Annotation> annoType) {

   204         // Since we can not refer to java.lang.annotation.Repeatable until we are

   205         // bootstrapping with java 8 we need to get the Repeatable annotation using

   206         // reflective invocations instead of just using its type and element method.

   207         if (REPEATABLE_CLASS != null &&

   208             VALUE_ELEMENT_METHOD != null) {

   209             // Get the Repeatable instance on the annotations declaration

   210             Annotation repeatable = (Annotation)annoType.getAnnotation(REPEATABLE_CLASS);

   211             if (repeatable != null) {

   212                 try {

   213                     // Get the value element, it should be a class

   214                     // indicating the containing annotation type

   215                     @SuppressWarnings("unchecked")

   216                     Class<? extends Annotation> containerType = (Class)VALUE_ELEMENT_METHOD.invoke(repeatable);

   217                     if (containerType == null)

   218                         return null;

   219 

   220                     return containerType;

   221                 } catch (ClassCastException | IllegalAccessException | InvocationTargetException e) {

   222                     return null;

   223                 }

   224             }

   225         }

   226         return null;

   227     }

   228 

   229 

   230     // Helper to getAnnotationsByType

   231     private static Attribute[] unpackAttributes(Attribute.Compound container) {

   232         // We now have an instance of the container,

   233         // unpack it returning an instance of the

   234         // contained type or null

   235         return ((Attribute.Array)container.member(container.type.tsym.name.table.names.value)).values;

   236     }

   237 

   238 }