1/*
2 * Copyright (c) 2012, 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
26package java.lang.invoke;
27
28import java.security.*;
29import java.lang.reflect.*;
30import java.lang.invoke.MethodHandleNatives.Constants;
31import java.lang.invoke.MethodHandles.Lookup;
32import static java.lang.invoke.MethodHandleStatics.*;
33
34/*
35 * Auxiliary to MethodHandleInfo, wants to nest in MethodHandleInfo but must be non-public.
36 */
37/*non-public*/
38final
39class InfoFromMemberName implements MethodHandleInfo {
40    private final MemberName member;
41    private final int referenceKind;
42
43    InfoFromMemberName(Lookup lookup, MemberName member, byte referenceKind) {
44        assert(member.isResolved() || member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke());
45        assert(member.referenceKindIsConsistentWith(referenceKind));
46        this.member = member;
47        this.referenceKind = referenceKind;
48    }
49
50    @Override
51    public Class<?> getDeclaringClass() {
52        return member.getDeclaringClass();
53    }
54
55    @Override
56    public String getName() {
57        return member.getName();
58    }
59
60    @Override
61    public MethodType getMethodType() {
62        return member.getMethodOrFieldType();
63    }
64
65    @Override
66    public int getModifiers() {
67        return member.getModifiers();
68    }
69
70    @Override
71    public int getReferenceKind() {
72        return referenceKind;
73    }
74
75    @Override
76    public String toString() {
77        return MethodHandleInfo.toString(getReferenceKind(), getDeclaringClass(), getName(), getMethodType());
78    }
79
80    @Override
81    public <T extends Member> T reflectAs(Class<T> expected, Lookup lookup) {
82        if ((member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke())
83            && !member.isVarargs()) {
84            // This member is an instance of a signature-polymorphic method, which cannot be reflected
85            // A method handle invoker can come in either of two forms:
86            // A generic placeholder (present in the source code, and varargs)
87            // and a signature-polymorphic instance (synthetic and not varargs).
88            // For more information see comments on {@link MethodHandleNatives#linkMethod}.
89            throw new IllegalArgumentException("cannot reflect signature polymorphic method");
90        }
91        Member mem = AccessController.doPrivileged(new PrivilegedAction<>() {
92                public Member run() {
93                    try {
94                        return reflectUnchecked();
95                    } catch (ReflectiveOperationException ex) {
96                        throw new IllegalArgumentException(ex);
97                    }
98                }
99            });
100        try {
101            Class<?> defc = getDeclaringClass();
102            byte refKind = (byte) getReferenceKind();
103            lookup.checkAccess(refKind, defc, convertToMemberName(refKind, mem));
104        } catch (IllegalAccessException ex) {
105            throw new IllegalArgumentException(ex);
106        }
107        return expected.cast(mem);
108    }
109
110    private Member reflectUnchecked() throws ReflectiveOperationException {
111        byte refKind = (byte) getReferenceKind();
112        Class<?> defc = getDeclaringClass();
113        boolean isPublic = Modifier.isPublic(getModifiers());
114        if (MethodHandleNatives.refKindIsMethod(refKind)) {
115            if (isPublic)
116                return defc.getMethod(getName(), getMethodType().parameterArray());
117            else
118                return defc.getDeclaredMethod(getName(), getMethodType().parameterArray());
119        } else if (MethodHandleNatives.refKindIsConstructor(refKind)) {
120            if (isPublic)
121                return defc.getConstructor(getMethodType().parameterArray());
122            else
123                return defc.getDeclaredConstructor(getMethodType().parameterArray());
124        } else if (MethodHandleNatives.refKindIsField(refKind)) {
125            if (isPublic)
126                return defc.getField(getName());
127            else
128                return defc.getDeclaredField(getName());
129        } else {
130            throw new IllegalArgumentException("referenceKind="+refKind);
131        }
132    }
133
134    private static MemberName convertToMemberName(byte refKind, Member mem) throws IllegalAccessException {
135        if (mem instanceof Method) {
136            boolean wantSpecial = (refKind == REF_invokeSpecial);
137            return new MemberName((Method) mem, wantSpecial);
138        } else if (mem instanceof Constructor) {
139            return new MemberName((Constructor) mem);
140        } else if (mem instanceof Field) {
141            boolean isSetter = (refKind == REF_putField || refKind == REF_putStatic);
142            return new MemberName((Field) mem, isSetter);
143        }
144        throw new InternalError(mem.getClass().getName());
145    }
146}
147