1 /*

     2  * Copyright (c) 2004, 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.apt.mirror.util;

    27 

    28 

    29 import com.sun.mirror.declaration.*;

    30 import com.sun.mirror.util.Declarations;

    31 import com.sun.tools.apt.mirror.declaration.DeclarationImpl;

    32 import com.sun.tools.apt.mirror.declaration.MethodDeclarationImpl;

    33 import com.sun.tools.apt.mirror.util.DeclarationsImpl;

    34 import com.sun.tools.apt.mirror.AptEnv;

    35 import com.sun.tools.javac.code.*;

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

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

    38 

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

    40 

    41 

    42 /**

    43  * Implementation of Declarations utility methods for annotation processors

    44  */

    45 @SuppressWarnings("deprecation")

    46 public class DeclarationsImpl implements Declarations {

    47 

    48     private final AptEnv env;

    49 

    50 

    51     private static final Context.Key<Declarations> declarationsKey =

    52             new Context.Key<Declarations>();

    53 

    54     public static Declarations instance(Context context) {

    55         Declarations instance = context.get(declarationsKey);

    56         if (instance == null) {

    57             instance = new DeclarationsImpl(context);

    58         }

    59         return instance;

    60     }

    61 

    62     private DeclarationsImpl(Context context) {

    63         context.put(declarationsKey, this);

    64         env = AptEnv.instance(context);

    65     }

    66 

    67 

    68     /**

    69      * {@inheritDoc}

    70      * See sections 8.3 and 8.4.6 of

    71      * <cite>The Java&trade; Language Specification</cite>

    72      */

    73     public boolean hides(MemberDeclaration sub, MemberDeclaration sup) {

    74         Symbol hider = ((DeclarationImpl) sub).sym;

    75         Symbol hidee = ((DeclarationImpl) sup).sym;

    76 

    77         // Fields only hide fields; methods only methods; types only types.

    78         // Names must match.  Nothing hides itself (just try it).

    79         if (hider == hidee ||

    80                 hider.kind != hidee.kind ||

    81                 hider.name != hidee.name) {

    82             return false;

    83         }

    84 

    85         // Only static methods can hide other methods.

    86         // Methods only hide methods with matching signatures.

    87         if (hider.kind == MTH) {

    88             if ((hider.flags() & Flags.STATIC) == 0 ||

    89                         !env.jctypes.isSubSignature(hider.type, hidee.type)) {

    90                 return false;

    91             }

    92         }

    93 

    94         // Hider must be in a subclass of hidee's class.

    95         // Note that if M1 hides M2, and M2 hides M3, and M3 is accessible

    96         // in M1's class, then M1 and M2 both hide M3.

    97         ClassSymbol hiderClass = hider.owner.enclClass();

    98         ClassSymbol hideeClass = hidee.owner.enclClass();

    99         if (hiderClass == null || hideeClass == null ||

   100                 !hiderClass.isSubClass(hideeClass, env.jctypes)) {

   101             return false;

   102         }

   103 

   104         // Hidee must be accessible in hider's class.

   105         // The method isInheritedIn is poorly named:  it checks only access.

   106         return hidee.isInheritedIn(hiderClass, env.jctypes);

   107     }

   108 

   109     /**

   110      * {@inheritDoc}

   111      * See section 8.4.6.1 of

   112      * <cite>The Java&trade; Language Specification</cite>

   113      */

   114     public boolean overrides(MethodDeclaration sub, MethodDeclaration sup) {

   115         MethodSymbol overrider = ((MethodDeclarationImpl) sub).sym;

   116         MethodSymbol overridee = ((MethodDeclarationImpl) sup).sym;

   117         ClassSymbol origin = (ClassSymbol) overrider.owner;

   118 

   119         return overrider.name == overridee.name &&

   120 

   121                // not reflexive as per JLS

   122                overrider != overridee &&

   123 

   124                // we don't care if overridee is static, though that wouldn't

   125                // compile

   126                !overrider.isStatic() &&

   127 

   128                // overrider, whose declaring type is the origin, must be

   129                // in a subtype of overridee's type

   130                env.jctypes.asSuper(origin.type, overridee.owner) != null &&

   131 

   132                // check access and signatures; don't check return types

   133                overrider.overrides(overridee, origin, env.jctypes, false);

   134     }

   135 }