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.MethodHandles.Lookup;
31
32 /*
33 * Auxiliary to MethodHandleInfo, wants to nest in MethodHandleInfo but must be non-public.
34 */
35 /*non-public*/
36 final class InfoFromMemberName implements MethodHandleInfo {
37 private final MemberName member;
38 private final int referenceKind;
39
40 InfoFromMemberName(Lookup lookup, MemberName member, byte referenceKind) {
41 assert(member.isResolved() || member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke());
42 assert(member.referenceKindIsConsistentWith(referenceKind));
43 this.member = member;
44 this.referenceKind = referenceKind;
45 }
46
47 @Override
48 public Class<?> getDeclaringClass() {
49 return member.getDeclaringClass();
50 }
51
52 @Override
53 public String getName() {
54 return member.getName();
55 }
56
57 @Override
58 public MethodType getMethodType() {
59 return member.getMethodOrFieldType();
60 }
61
62 @Override
63 public int getModifiers() {
64 return member.getModifiers();
65 }
66
67 @Override
68 public int getReferenceKind() {
69 return referenceKind;
70 }
71
72 @Override
73 public String toString() {
74 return MethodHandleInfo.toString(getReferenceKind(), getDeclaringClass(), getName(), getMethodType());
75 }
76
77 @Override
78 public <T extends Member> T reflectAs(Class<T> expected, Lookup lookup) {
79 if ((member.isMethodHandleInvoke() || member.isVarHandleMethodInvoke())
80 && !member.isVarargs()) {
81 // This member is an instance of a signature-polymorphic method, which cannot be reflected
82 // A method handle invoker can come in either of two forms:
83 // A generic placeholder (present in the source code, and varargs)
84 // and a signature-polymorphic instance (synthetic and not varargs).
85 // For more information see comments on {@link MethodHandleNatives#linkMethod}.
86 throw new IllegalArgumentException("cannot reflect signature polymorphic method");
87 }
88 @SuppressWarnings("removal")
89 Member mem = AccessController.doPrivileged(new PrivilegedAction<>() {
90 public Member run() {
91 try {
92 return reflectUnchecked();
93 } catch (ReflectiveOperationException ex) {
94 throw new IllegalArgumentException(ex);
95 }
96 }
97 });
98 try {
99 Class<?> defc = getDeclaringClass();
100 byte refKind = (byte) getReferenceKind();
101 lookup.checkAccess(refKind, defc, convertToMemberName(refKind, mem));
102 } catch (IllegalAccessException ex) {
103 throw new IllegalArgumentException(ex);
104 }
105 return expected.cast(mem);
106 }
107
108 private Member reflectUnchecked() throws ReflectiveOperationException {
109 byte refKind = (byte) getReferenceKind();
110 Class<?> defc = getDeclaringClass();
111 boolean isPublic = Modifier.isPublic(getModifiers());
112 if (member.isObjectConstructorOrStaticInitMethod()) {
113 MethodType methodType = getMethodType();
114 if (MethodHandleNatives.refKindIsObjectConstructor(refKind) &&
115 methodType.returnType() != void.class) {
116 // object constructor
117 throw new IllegalArgumentException("object constructor must be of void return type");
118 } else if (MethodHandleNatives.refKindIsMethod(refKind) &&
119 methodType.returnType() != defc.asValueType()) {
120 // TODO: allow to return Object or perhaps one of the supertypes of that class
121 // static init factory
122 throw new IllegalArgumentException("static constructor must be of " + defc.getName());
123 }
124
125 return isPublic ? defc.getConstructor(methodType.parameterArray())
126 : defc.getDeclaredConstructor(methodType.parameterArray());
127 } else if (MethodHandleNatives.refKindIsMethod(refKind)) {
128 if (isPublic)
129 return defc.getMethod(getName(), getMethodType().parameterArray());
130 else
131 return defc.getDeclaredMethod(getName(), getMethodType().parameterArray());
132 } else if (MethodHandleNatives.refKindIsField(refKind)) {
133 if (isPublic)
134 return defc.getField(getName());
135 else
136 return defc.getDeclaredField(getName());
137 } else {
138 throw new IllegalArgumentException("referenceKind="+refKind);
139 }
140 }
141
142 private static MemberName convertToMemberName(byte refKind, Member mem) throws IllegalAccessException {
143 if (mem instanceof Method) {
144 boolean wantSpecial = (refKind == REF_invokeSpecial);
145 return new MemberName((Method) mem, wantSpecial);
146 } else if (mem instanceof Constructor) {
147 return new MemberName((Constructor) mem);
148 } else if (mem instanceof Field) {
149 boolean isSetter = (refKind == REF_putField || refKind == REF_putStatic);
150 return new MemberName((Field) mem, isSetter);
151 }
152 throw new InternalError(mem.getClass().getName());
153 }
154 }