1 /*
   2  * Copyright (c) 2005, 2016, 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.processing;
  27 
  28 import java.lang.annotation.Annotation;
  29 import javax.annotation.processing.*;
  30 import javax.lang.model.element.*;
  31 import javax.lang.model.util.*;
  32 import java.util.*;
  33 
  34 import com.sun.tools.javac.util.DefinedBy;
  35 import com.sun.tools.javac.util.DefinedBy.Api;
  36 
  37 /**
  38  * Object providing state about a prior round of annotation processing.
  39  *
  40  * <p>The methods in this class do not take type annotations into account,
  41  * as target types, not java elements.
  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 risk.
  45  * This code and its internal interfaces are subject to change or
  46  * deletion without notice.</b>
  47  */
  48 public class JavacRoundEnvironment implements RoundEnvironment {
  49     // Default equals and hashCode methods are okay.
  50 
  51     private final boolean processingOver;
  52     private final boolean errorRaised;
  53     private final ProcessingEnvironment processingEnv;
  54     private final Elements eltUtils;
  55 
  56     // Caller must pass in an immutable set
  57     private final Set<? extends Element> rootElements;
  58 
  59     JavacRoundEnvironment(boolean processingOver,
  60                           boolean errorRaised,
  61                           Set<? extends Element> rootElements,
  62                           ProcessingEnvironment processingEnv) {
  63         this.processingOver = processingOver;
  64         this.errorRaised = errorRaised;
  65         this.rootElements = rootElements;
  66         this.processingEnv = processingEnv;
  67         this.eltUtils = processingEnv.getElementUtils();
  68     }
  69 
  70     public String toString() {
  71         return String.format("[errorRaised=%b, rootElements=%s, processingOver=%b]",
  72                              errorRaised,
  73                              rootElements,
  74                              processingOver);
  75     }
  76 
  77     @DefinedBy(Api.ANNOTATION_PROCESSING)
  78     public boolean processingOver() {
  79         return processingOver;
  80     }
  81 
  82     /**
  83      * Returns {@code true} if an error was raised in the prior round
  84      * of processing; returns {@code false} otherwise.
  85      *
  86      * @return {@code true} if an error was raised in the prior round
  87      * of processing; returns {@code false} otherwise.
  88      */
  89     @DefinedBy(Api.ANNOTATION_PROCESSING)
  90     public boolean errorRaised() {
  91         return errorRaised;
  92     }
  93 
  94     /**
  95      * Returns the type elements specified by the prior round.
  96      *
  97      * @return the types elements specified by the prior round, or an
  98      * empty set if there were none
  99      */
 100     @DefinedBy(Api.ANNOTATION_PROCESSING)
 101     public Set<? extends Element> getRootElements() {
 102         return rootElements;
 103     }
 104 
 105     /**
 106      * Returns the elements annotated with the given annotation type.
 107      * Only type elements <i>included</i> in this round of annotation
 108      * processing, or declarations of members, parameters, or type
 109      * parameters declared within those, are returned.  Included type
 110      * elements are {@linkplain #getRootElements specified
 111      * types} and any types nested within them.
 112      *
 113      * @param a  annotation type being requested
 114      * @return the elements annotated with the given annotation type,
 115      * or an empty set if there are none
 116      */
 117     @DefinedBy(Api.ANNOTATION_PROCESSING)
 118     public Set<? extends Element> getElementsAnnotatedWith(TypeElement a) {
 119         throwIfNotAnnotation(a);
 120 
 121         Set<Element> result = Collections.emptySet();
 122         ElementScanner9<Set<Element>, TypeElement> scanner =
 123             new AnnotationSetScanner(result);
 124 
 125         for (Element element : rootElements)
 126             result = scanner.scan(element, a);
 127 
 128         return result;
 129     }
 130 
 131     @DefinedBy(Api.ANNOTATION_PROCESSING)
 132     public Set<? extends Element> getElementsAnnotatedWithAny(TypeElement... annotations) {
 133         // Don't bother to special-case annotations.length == 1 as
 134         // return getElementsAnnotatedWith(annotations[0]);
 135 
 136         Set<TypeElement> annotationSet = new LinkedHashSet<>(annotations.length);
 137         for (TypeElement annotation : annotations) {
 138             throwIfNotAnnotation(annotation);
 139             annotationSet.add(annotation);
 140         }
 141 
 142         Set<Element> result = Collections.emptySet();
 143         ElementScanner9<Set<Element>, Set<TypeElement>> scanner =
 144             new AnnotationSetMultiScanner(result);
 145 
 146         for (Element element : rootElements)
 147             result = scanner.scan(element, annotationSet);
 148 
 149         return result;
 150     }
 151 
 152     // Could be written as a local class inside getElementsAnnotatedWith
 153     private class AnnotationSetScanner extends
 154         ElementScanningIncludingTypeParameters<Set<Element>, TypeElement> {
 155         // Insertion-order preserving set
 156         private Set<Element> annotatedElements = new LinkedHashSet<>();
 157 
 158         AnnotationSetScanner(Set<Element> defaultSet) {
 159             super(defaultSet);
 160         }
 161 
 162         @Override @DefinedBy(Api.LANGUAGE_MODEL)
 163         public Set<Element> scan(Element e, TypeElement annotation) {
 164             for (AnnotationMirror annotMirror :  eltUtils.getAllAnnotationMirrors(e)) {
 165                 if (annotation.equals(mirrorAsElement(annotMirror))) {
 166                     annotatedElements.add(e);
 167                     break;
 168                 }
 169             }
 170             e.accept(this, annotation);
 171             return annotatedElements;
 172         }
 173     }
 174 
 175     // Could be written as a local class inside getElementsAnnotatedWithAny
 176     private class AnnotationSetMultiScanner extends
 177         ElementScanningIncludingTypeParameters<Set<Element>, Set<TypeElement>> {
 178         // Insertion-order preserving set
 179         private Set<Element> annotatedElements = new LinkedHashSet<>();
 180 
 181         AnnotationSetMultiScanner(Set<Element> defaultSet) {
 182             super(defaultSet);
 183         }
 184 
 185         @Override @DefinedBy(Api.LANGUAGE_MODEL)
 186         public Set<Element> scan(Element e, Set<TypeElement> annotations) {
 187             for (AnnotationMirror annotMirror : eltUtils.getAllAnnotationMirrors(e)) {
 188                 if (annotations.contains(mirrorAsElement(annotMirror))) {
 189                     annotatedElements.add(e);
 190                     break;
 191                 }
 192             }
 193             e.accept(this, annotations);
 194             return annotatedElements;
 195         }
 196     }
 197 
 198     private static abstract class ElementScanningIncludingTypeParameters<R, P>
 199         extends ElementScanner9<R, P> {
 200 
 201         protected ElementScanningIncludingTypeParameters(R defaultValue) {
 202             super(defaultValue);
 203         }
 204 
 205         @Override @DefinedBy(Api.LANGUAGE_MODEL)
 206         public R visitType(TypeElement e, P p) {
 207             // Type parameters are not considered to be enclosed by a type
 208             scan(e.getTypeParameters(), p);
 209             return super.visitType(e, p);
 210         }
 211 
 212         @Override @DefinedBy(Api.LANGUAGE_MODEL)
 213         public R visitExecutable(ExecutableElement e, P p) {
 214             // Type parameters are not considered to be enclosed by an executable
 215             scan(e.getTypeParameters(), p);
 216             return super.visitExecutable(e, p);
 217         }
 218     }
 219 
 220     /**
 221      * {@inheritDoc}
 222      */
 223     @DefinedBy(Api.ANNOTATION_PROCESSING)
 224     public Set<? extends Element> getElementsAnnotatedWith(Class<? extends Annotation> a) {
 225         throwIfNotAnnotation(a);
 226         String name = a.getCanonicalName();
 227         if (name == null)
 228             return Collections.emptySet();
 229         else {
 230             TypeElement annotationType = eltUtils.getTypeElement(name);
 231             if (annotationType == null)
 232                 return Collections.emptySet();
 233             else
 234                 return getElementsAnnotatedWith(annotationType);
 235         }
 236     }
 237 
 238     @DefinedBy(Api.ANNOTATION_PROCESSING)
 239     public Set<? extends Element> getElementsAnnotatedWithAny(Set<Class<? extends Annotation>> annotations) {
 240         List<TypeElement> annotationsAsElements = new ArrayList<>(annotations.size());
 241 
 242         for (Class<? extends Annotation> annotation : annotations) {
 243             throwIfNotAnnotation(annotation);
 244             String name = annotation.getCanonicalName();
 245             if (name == null)
 246                 continue;
 247             annotationsAsElements.add(eltUtils.getTypeElement(name));
 248         }
 249 
 250         return getElementsAnnotatedWithAny(annotationsAsElements.toArray(new TypeElement[0]));
 251     }
 252 
 253     private Element mirrorAsElement(AnnotationMirror annotationMirror) {
 254         return annotationMirror.getAnnotationType().asElement();
 255     }
 256 
 257     private static final String NOT_AN_ANNOTATION_TYPE =
 258         "The argument does not represent an annotation type: ";
 259 
 260     private void throwIfNotAnnotation(Class<? extends Annotation> a) {
 261         if (!a.isAnnotation())
 262             throw new IllegalArgumentException(NOT_AN_ANNOTATION_TYPE + a);
 263     }
 264 
 265     private void throwIfNotAnnotation(TypeElement a) {
 266         if (a.getKind() != ElementKind.ANNOTATION_TYPE)
 267             throw new IllegalArgumentException(NOT_AN_ANNOTATION_TYPE + a);
 268     }
 269 }