1 /*
2 * Copyright (c) 2012, 2021, 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 java.lang.invoke;
27
28 import java.security.*;
29 import java.lang.reflect.*;
30 import java.lang.invoke.MethodHandleNatives.Constants;
31 import java.lang.invoke.MethodHandles.Lookup;
32 import 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*/
38 final class InfoFromMemberName implements MethodHandleInfo {
39 private final MemberName member;
40 private final int referenceKind;
41
42 InfoFromMemberName(Lookup lookup, MemberName member, byte referenceKind) {
43 assert(member.isResolved() || member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke());
44 assert(member.referenceKindIsConsistentWith(referenceKind));
45 this.member = member;
46 this.referenceKind = referenceKind;
47 }
48
49 @Override
50 public Class<?> getDeclaringClass() {
51 return member.getDeclaringClass();
52 }
53
54 @Override
55 public String getName() {
56 return member.getName();
57 }
58
59 @Override
60 public MethodType getMethodType() {
61 return member.getMethodOrFieldType();
62 }
63
64 @Override
65 public int getModifiers() {
66 return member.getModifiers();
67 }
68
69 @Override
70 public int getReferenceKind() {
71 return referenceKind;
72 }
73
74 @Override
75 public String toString() {
76 return MethodHandleInfo.toString(getReferenceKind(), getDeclaringClass(), getName(), getMethodType());
77 }
78
79 @Override
80 public <T extends Member> T reflectAs(Class<T> expected, Lookup lookup) {
81 if ((member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke())
82 && !member.isVarargs()) {
83 // This member is an instance of a signature-polymorphic method, which cannot be reflected
84 // A method handle invoker can come in either of two forms:
85 // A generic placeholder (present in the source code, and varargs)
86 // and a signature-polymorphic instance (synthetic and not varargs).
87 // For more information see comments on {@link MethodHandleNatives#linkMethod}.
88 throw new IllegalArgumentException("cannot reflect signature polymorphic method");
89 }
90 @SuppressWarnings("removal")
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 }