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.model;

    26 

    27 import java.lang.annotation.Annotation;

    28 import java.lang.annotation.Inherited;

    29 import java.lang.reflect.InvocationTargetException;

    30 import java.lang.reflect.Method;

    31 

    32 import com.sun.tools.javac.code.Attribute;

    33 import com.sun.tools.javac.code.Kinds;

    34 import com.sun.tools.javac.code.Symbol;

    35 import com.sun.tools.javac.code.Symbol.ClassSymbol;

    36 import com.sun.tools.javac.code.Symbol.TypeVariableSymbol;

    37 import com.sun.tools.javac.code.TargetType;

    38 import com.sun.tools.javac.code.Type;

    39 import com.sun.tools.javac.code.Type.AnnotatedType;

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

    41 import static com.sun.tools.javac.code.TypeTag.CLASS;

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

    43 

    44 /**

    45  * Utility methods for operating on annotated constructs.

    46  *

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

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

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

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

    51  */

    52 public class JavacAnnoConstructs {

    53 

    54     // <editor-fold defaultstate="collapsed" desc="Symbols">

    55 

    56     /**

    57      * An internal-use utility that creates a runtime view of an

    58      * annotation. This is the implementation of

    59      * Element.getAnnotation(Class).

    60      */

    61     public static <A extends Annotation> A getAnnotation(Symbol annotated,

    62                                                          Class<A> annoType) {

    63         if (!annoType.isAnnotation())

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

    65                                                + annoType);

    66         Attribute.Compound c;

    67         if (annotated.kind == Kinds.TYP &&

    68                 annotated instanceof ClassSymbol) {

    69             c = getAttributeOnClass((ClassSymbol)annotated, annoType);

    70         } else if (annotated.kind == Kinds.TYP &&

    71                    annotated instanceof TypeVariableSymbol) {

    72             c = getAttributeOnTypeVariable((TypeVariableSymbol)annotated, annoType);

    73         } else {

    74             c = getAttribute(annotated, annoType);

    75         }

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

    77     }

    78 

    79     // Helper to getAnnotation[s]

    80     private static <A extends Annotation> Attribute.Compound getAttribute(Symbol annotated,

    81                                                                           Class<A> annoType) {

    82         String name = annoType.getName();

    83 

    84         for (Attribute.Compound anno : annotated.getRawAttributes()) {

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

    86                 return anno;

    87         }

    88 

    89         return null;

    90     }

    91 

    92     // Helper to getAnnotation[s]

    93     private static <A extends Annotation> Attribute.Compound

    94             getAttributeOnTypeVariable(TypeVariableSymbol annotated, Class<A> annoType) {

    95         String name = annoType.getName();

    96 

    97         // Declaration annotations on type variables are stored in type attributes

    98         // on the owner of the TypeVariableSymbol

    99         List<Attribute.Compound> res = List.nil();

   100         List<Attribute.TypeCompound> candidates = annotated.owner.getRawTypeAttributes();

   101         for (Attribute.TypeCompound anno : candidates)

   102             if (anno.position.type == TargetType.CLASS_TYPE_PARAMETER ||

   103                     anno.position.type == TargetType.METHOD_TYPE_PARAMETER)

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

   105                     return anno;

   106 

   107         return null;

   108     }

   109 

   110     // Helper to getAnnotation[s]

   111     private static <A extends Annotation> Attribute.Compound getAttributeOnClass(

   112             ClassSymbol annotated,

   113             final Class<A> annoType)

   114     {

   115         boolean inherited = annoType.isAnnotationPresent(Inherited.class);

   116         Attribute.Compound result = null;

   117 

   118         result = getAttribute(annotated, annoType);

   119         if (result != null || !inherited)

   120             return result;

   121 

   122         while ((annotated = nextSupertypeToSearch(annotated)) != null) {

   123             result = getAttribute(annotated, annoType);

   124             if (result != null)

   125                 return result;

   126         }

   127         return null; // no more supertypes to search

   128     }

   129 

   130     /**

   131      * Returns the next type to search for inherited annotations or {@code null}

   132      * if the next type can't be found.

   133      */

   134     private static ClassSymbol nextSupertypeToSearch(ClassSymbol annotated) {

   135         if (annotated.name == annotated.name.table.names.java_lang_Object)

   136             return null;

   137 

   138         Type sup = annotated.getSuperclass();

   139         if (!sup.hasTag(CLASS) || sup.isErroneous())

   140             return null;

   141 

   142         return (ClassSymbol) sup.tsym;

   143     }

   144 

   145     /**

   146      * An internal-use utility that creates a runtime view of

   147      * annotations. This is the implementation of

   148      * Element.getAnnotations(Class).

   149      */

   150     public static <A extends Annotation> A[] getAnnotationsByType(Symbol annotated,

   151             Class<A> annoType)

   152     {

   153         if (!annoType.isAnnotation())

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

   155                                                + annoType);

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

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

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

   159         if (containerType == null) {

   160             A res = getAnnotation(annotated, annoType);

   161             int size;

   162             if (res == null) {

   163                 size = 0;

   164             } else {

   165                 size = 1;

   166             }

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

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

   169             if (res != null)

   170                 arr[0] = res;

   171             return arr;

   172         }

   173 

   174         // So we have a containing type

   175         String annoTypeName = annoType.getName();

   176         String containerTypeName = containerType.getName();

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

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

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

   180         int index = -1;

   181         for (List<Attribute.Compound> list = annotated.getAnnotationMirrors();

   182                 !list.isEmpty();

   183                 list = list.tail) {

   184             Attribute.Compound attribute = list.head;

   185             index++;

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

   187                 directIndex = index;

   188                 direct = attribute;

   189             } else if(containerTypeName != null &&

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

   191                 containerIndex = index;

   192                 container = attribute;

   193             }

   194         }

   195 

   196         // Deal with inherited annotations

   197         if (direct == null && container == null) {

   198             if (annotated.kind == Kinds.TYP &&

   199                     (annotated instanceof ClassSymbol)) {

   200                 ClassSymbol s = nextSupertypeToSearch((ClassSymbol)annotated);

   201                 if (s != null)

   202                     return getAnnotationsByType(s, annoType);

   203             }

   204         }

   205 

   206         // Pack them in an array

   207         Attribute[] contained0 = null;

   208         if (container != null)

   209             contained0 = unpackAttributes(container);

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

   211         if (contained0 != null) {

   212             for (Attribute a : contained0)

   213                 if (a instanceof Attribute.Compound)

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

   215         }

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

   217 

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

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

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

   221 

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

   223         int insert = -1;

   224         int length = arr.length;

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

   226             if (directIndex < containerIndex) {

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

   228                 insert = 1;

   229             } else {

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

   231                 insert = 0;

   232                 length--;

   233             }

   234         } else if (directIndex >= 0) {

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

   236             return arr;

   237         } else {

   238             // Only container

   239             insert = 0;

   240         }

   241 

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

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

   244 

   245         return arr;

   246     }

   247 

   248     // </editor-fold>

   249 

   250     // <editor-fold defaultstate="collapsed" desc="Types">

   251 

   252     /**

   253      * An internal-use utility that creates a runtime view of an

   254      * annotation. This is the implementation of

   255      * TypeMirror.getAnnotation(Class).

   256      */

   257     public static <A extends Annotation> A getAnnotation(AnnotatedType annotated, Class<A> annoType) {

   258         if (!annoType.isAnnotation())

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

   260                                                + annoType);

   261         Attribute.Compound c = getAttribute(annotated, annoType);

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

   263     }

   264 

   265     // Helper to getAnnotation[s]

   266     private static <A extends Annotation> Attribute.Compound getAttribute(Type annotated,

   267                                                                           Class<A> annoType) {

   268         String name = annoType.getName();

   269 

   270         for (Attribute.Compound anno : annotated.getAnnotationMirrors()) {

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

   272                 return anno;

   273         }

   274 

   275         return null;

   276     }

   277 

   278     /**

   279      * An internal-use utility that creates a runtime view of

   280      * annotations. This is the implementation of

   281      * TypeMirror.getAnnotationsByType(Class).

   282      */

   283     public static <A extends Annotation> A[] getAnnotationsByType(AnnotatedType annotated, Class<A> annoType) {

   284         if (!annoType.isAnnotation())

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

   286                                                + annoType);

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

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

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

   290         if (containerType == null) {

   291             A res = getAnnotation(annotated, annoType);

   292             int size;

   293             if (res == null) {

   294                 size = 0;

   295             } else {

   296                 size = 1;

   297             }

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

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

   300             if (res != null)

   301                 arr[0] = res;

   302             return arr;

   303         }

   304 

   305         // So we have a containing type

   306         String annoTypeName = annoType.getName();

   307         String containerTypeName = containerType.getName();

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

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

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

   311         int index = -1;

   312         for (List<? extends Attribute.Compound> list = annotated.getAnnotationMirrors();

   313                 !list.isEmpty();

   314                 list = list.tail) {

   315             Attribute.Compound attribute = list.head;

   316             index++;

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

   318                 directIndex = index;

   319                 direct = attribute;

   320             } else if(containerTypeName != null &&

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

   322                 containerIndex = index;

   323                 container = attribute;

   324             }

   325         }

   326 

   327         // Pack them in an array

   328         Attribute[] contained0 = null;

   329         if (container != null)

   330             contained0 = unpackAttributes(container);

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

   332         if (contained0 != null) {

   333             for (Attribute a : contained0)

   334                 if (a instanceof Attribute.Compound)

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

   336         }

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

   338 

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

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

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

   342 

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

   344         int insert = -1;

   345         int length = arr.length;

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

   347             if (directIndex < containerIndex) {

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

   349                 insert = 1;

   350             } else {

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

   352                 insert = 0;

   353                 length--;

   354             }

   355         } else if (directIndex >= 0) {

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

   357             return arr;

   358         } else {

   359             // Only container

   360             insert = 0;

   361         }

   362 

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

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

   365 

   366         return arr;

   367     }

   368 

   369     // </editor-fold>

   370 

   371     // <editor-fold defaultstate="collapsed" desc="Container support">

   372 

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

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

   375     private static final Method VALUE_ELEMENT_METHOD = initValueElementMethod();

   376 

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

   378         try {

   379             // Repeatable will not be available when bootstrapping on

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

   381             // literal for Repeatable.class.

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

   383         } catch (ClassNotFoundException e) {

   384             return null;

   385         } catch (SecurityException e) {

   386             return null;

   387         }

   388     }

   389 

   390     private static Method initValueElementMethod() {

   391         if (REPEATABLE_CLASS == null)

   392             return null;

   393 

   394         Method m = null;

   395         try {

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

   397             if (m != null)

   398                 m.setAccessible(true);

   399             return m;

   400         } catch (NoSuchMethodException e) {

   401             return null;

   402         }

   403     }

   404 

   405     // Helper to getAnnotations

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

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

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

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

   410         if (REPEATABLE_CLASS != null &&

   411             VALUE_ELEMENT_METHOD != null) {

   412             // Get the Repeatable instance on the annotations declaration

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

   414             if (repeatable != null) {

   415                 try {

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

   417                     // indicating the containing annotation type

   418                     @SuppressWarnings("unchecked")

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

   420                     if (containerType == null)

   421                         return null;

   422 

   423                     return containerType;

   424                 } catch (ClassCastException e) {

   425                     return null;

   426                 } catch (IllegalAccessException e) {

   427                     return null;

   428                 } catch (InvocationTargetException e ) {

   429                     return null;

   430                 }

   431             }

   432         }

   433         return null;

   434     }

   435 

   436     // Helper to getAnnotations

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

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

   439         // unpack it returning an instance of the

   440         // contained type or null

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

   442     }

   443 

   444     // </editor-fold>

   445 }