1 /*

     2  * Copyright (c) 2012, 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 java.util.Map;

    29 import javax.tools.JavaFileObject;

    30 

    31 import com.sun.tools.javac.comp.Annotate;

    32 import com.sun.tools.javac.comp.AttrContext;

    33 import com.sun.tools.javac.comp.Env;

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

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

    36 import com.sun.tools.javac.util.Log;

    37 import com.sun.tools.javac.util.Pair;

    38 

    39 import static com.sun.tools.javac.code.Kinds.PCK;

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

    41 

    42 /**

    43  * Container for all annotations (attributes in javac) on a Symbol.

    44  *

    45  * This class is explicitly mutable. Its contents will change when attributes

    46  * are annotated onto the Symbol. However this class depends on the facts that

    47  * List (in javac) is immutable.

    48  *

    49  * An instance of this class can be in one of three states:

    50  *

    51  * NOT_STARTED indicates that the Symbol this instance belongs to have not been

    52  * annotated (yet). Specifically if the declaration is not annotated this

    53  * instance will never move past NOT_STARTED. You can never go back to

    54  * NOT_STARTED.

    55  *

    56  * IN_PROGRESS annotations have been found on the declaration. Will be processed

    57  * later. You can reset to IN_PROGRESS. While IN_PROGRESS you can set the list

    58  * of attributes (and this moves out of the IN_PROGRESS state).

    59  *

    60  * "unnamed" this Annotations contains some attributes, possibly the final set.

    61  * While in this state you can only prepend or append to the attributes not set

    62  * it directly. You can also move back to the IN_PROGRESS sate using reset().

    63  *

    64  * <p><b>This is NOT part of any supported API. If you write code that depends

    65  * on this, you do so at your own risk. This code and its internal interfaces

    66  * are subject to change or deletion without notice.</b>

    67  */

    68 public class Annotations {

    69 

    70     private static final List<Attribute.Compound> NOT_STARTED = List.of(null);

    71     private static final List<Attribute.Compound> IN_PROGRESS = List.of(null);

    72     /*

    73      * This field should never be null

    74      */

    75     private List<Attribute.Compound> attributes = NOT_STARTED;

    76     /*

    77      * The Symbol this Annotatios belong to

    78      */

    79     private final Symbol s;

    80 

    81     public Annotations(Symbol s) {

    82         this.s = s;

    83     }

    84 

    85     public List<Attribute.Compound> getAttributes() {

    86         return filterSentinels(attributes);

    87     }

    88 

    89     public void setAttributes(List<Attribute.Compound> a) {

    90         Assert.check(pendingCompletion() || !isStarted());

    91         if (a == null) {

    92             throw new NullPointerException();

    93         }

    94         attributes = a;

    95     }

    96 

    97     public void setAttributes(Annotations other) {

    98         if (other == null) {

    99             throw new NullPointerException();

   100         }

   101         setAttributes(other.getAttributes());

   102     }

   103 

   104     public void setAttributesWithCompletion(final Annotate.AnnotateRepeatedContext ctx) {

   105         Assert.check(pendingCompletion() || (!isStarted() && s.kind == PCK));

   106 

   107         Map<Symbol.TypeSymbol, ListBuffer<Attribute.Compound>> annotated = ctx.annotated;

   108         boolean atLeastOneRepeated = false;

   109         List<Attribute.Compound> buf = List.<Attribute.Compound>nil();

   110         for (ListBuffer<Attribute.Compound> lb : annotated.values()) {

   111             if (lb.size() == 1) {

   112                 buf = buf.prepend(lb.first());

   113             } else { // repeated

   114                 buf = buf.prepend(new Placeholder(lb.toList(), s));

   115                 atLeastOneRepeated = true;

   116             }

   117         }

   118 

   119         // Add non-repeating attributes

   120         setAttributes(buf.reverse());

   121 

   122         if (atLeastOneRepeated) {

   123             // The Symbol s is now annotated with a combination of

   124             // finished non-repeating annotations and placeholders for

   125             // repeating annotations.

   126             //

   127             // We need to do this in two passes because when creating

   128             // a container for a repeating annotation we must

   129             // guarantee that the @ContainedBy on the

   130             // contained annotation is fully annotated

   131             //

   132             // The way we force this order is to do all repeating

   133             // annotations in a pass after all non-repeating are

   134             // finished. This will work because @ContainedBy

   135             // is non-repeating and therefore will be annotated in the

   136             // fist pass.

   137 

   138             // Queue a pass that will replace Attribute.Placeholders

   139             // with Attribute.Compound (made from synthesized containers).

   140             ctx.annotateRepeated(new Annotate.Annotator() {

   141 

   142                 @Override

   143                 public String toString() {

   144                     return "repeated annotation pass of: " + s + " in: " + s.owner;

   145                 }

   146 

   147                 @Override

   148                 public void enterAnnotation() {

   149                     complete(ctx);

   150                 }

   151             });

   152         }

   153     }

   154 

   155     public Annotations reset() {

   156         attributes = IN_PROGRESS;

   157         return this;

   158     }

   159 

   160     public boolean isEmpty() {

   161         return !isStarted()

   162                 || pendingCompletion()

   163                 || attributes.isEmpty();

   164     }

   165 

   166     public boolean pendingCompletion() {

   167         return attributes == IN_PROGRESS;

   168     }

   169 

   170     public Annotations append(List<Attribute.Compound> l) {

   171         attributes = filterSentinels(attributes);

   172 

   173         if (l.isEmpty()) {

   174             ; // no-op

   175         } else if (attributes.isEmpty()) {

   176             attributes = l;

   177         } else {

   178             attributes = attributes.appendList(l);

   179         }

   180         return this;

   181     }

   182 

   183     public Annotations prepend(List<Attribute.Compound> l) {

   184         attributes = filterSentinels(attributes);

   185 

   186         if (l.isEmpty()) {

   187             ; // no-op

   188         } else if (attributes.isEmpty()) {

   189             attributes = l;

   190         } else {

   191             attributes = attributes.prependList(l);

   192         }

   193         return this;

   194     }

   195 

   196     private List<Attribute.Compound> filterSentinels(List<Attribute.Compound> a) {

   197         return (a == IN_PROGRESS || a == NOT_STARTED)

   198                 ? List.<Attribute.Compound>nil()

   199                 : a;

   200     }

   201 

   202     private boolean isStarted() {

   203         return attributes != NOT_STARTED;

   204     }

   205 

   206     private List<Attribute.Compound> getPlaceholders() {

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

   208         for (Attribute.Compound a : filterSentinels(attributes)) {

   209             if (a instanceof Placeholder) {

   210                 res = res.prepend(a);

   211             }

   212         }

   213         return res.reverse();

   214     }

   215 

   216     /*

   217      * Replace Placeholders for repeating annotations with their containers

   218      */

   219     private void complete(Annotate.AnnotateRepeatedContext ctx) {

   220         Assert.check(!pendingCompletion());

   221         Log log = ctx.log;

   222         Env<AttrContext> env = ctx.env;

   223         JavaFileObject oldSource = log.useSource(env.toplevel.sourcefile);

   224         try {

   225 

   226             if (isEmpty()) {

   227                 return;

   228             }

   229 

   230             List<Attribute.Compound> result = List.nil();

   231             for (Attribute.Compound a : getAttributes()) {

   232                 if (a instanceof Placeholder) {

   233                     Attribute.Compound replacement = replaceOne((Placeholder) a, ctx);

   234 

   235                     if (null != replacement) {

   236                         result = result.prepend(replacement);

   237                     }

   238                 } else {

   239                     result = result.prepend(a);

   240                 }

   241             }

   242 

   243             attributes = result.reverse();

   244 

   245             Assert.check(Annotations.this.getPlaceholders().isEmpty());

   246         } finally {

   247             log.useSource(oldSource);

   248         }

   249     }

   250 

   251     private Attribute.Compound replaceOne(Placeholder placeholder, Annotate.AnnotateRepeatedContext ctx) {

   252         Log log = ctx.log;

   253 

   254         // Process repeated annotations

   255         Attribute.Compound validRepeated =

   256                 ctx.processRepeatedAnnotations(placeholder.getPlaceholderFor());

   257 

   258         if (validRepeated != null) {

   259             // Check that the container isn't manually

   260             // present along with repeated instances of

   261             // its contained annotation.

   262             ListBuffer<Attribute.Compound> manualContainer = ctx.annotated.get(validRepeated.type.tsym);

   263             if (manualContainer != null) {

   264                 log.error(ctx.pos.get(manualContainer.first()), "invalid.containedby.annotation.repeated.and.container.present",

   265                         manualContainer.first().type.tsym);

   266             }

   267         }

   268 

   269         // A null return will delete the Placeholder

   270         return validRepeated;

   271 

   272     }

   273 

   274     private static class Placeholder extends Attribute.Compound {

   275 

   276         private List<Attribute.Compound> placeholderFor;

   277         private Symbol on;

   278 

   279         public Placeholder(List<Attribute.Compound> placeholderFor, Symbol on) {

   280             super(Type.noType, List.<Pair<Symbol.MethodSymbol, Attribute>>nil());

   281             this.placeholderFor = placeholderFor;

   282             this.on = on;

   283         }

   284 

   285         @Override

   286         public String toString() {

   287             return "<placeholder: " + placeholderFor + " on: " + on + ">";

   288         }

   289 

   290         public List<Attribute.Compound> getPlaceholderFor() {

   291             return placeholderFor;

   292         }

   293     }

   294 }