1 /*
2 * Copyright (c) 2018, 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 package java.lang.constant;
26
27 import java.lang.invoke.MethodHandle;
28 import java.lang.invoke.MethodHandles;
29 import java.lang.invoke.MethodType;
30 import java.util.Objects;
31 import java.util.Optional;
32
33 import static java.lang.constant.ConstantDescs.CR_DirectMethodHandleDesc;
34 import static java.lang.constant.ConstantDescs.DEFAULT_NAME;
35 import static java.lang.constant.ConstantUtils.validateClassOrInterface;
36 import static java.lang.constant.ConstantUtils.validateMemberName;
37 import static java.lang.constant.DirectMethodHandleDesc.Kind.CONSTRUCTOR;
38 import static java.util.Objects.requireNonNull;
39
40 /**
41 * A <a href="package-summary.html#nominal">nominal descriptor</a> for a direct
42 * {@link MethodHandle}. A {@linkplain DirectMethodHandleDescImpl} corresponds to
43 * a {@code Constant_MethodHandle_info} entry in the constant pool of a classfile.
44 */
45 final class DirectMethodHandleDescImpl implements DirectMethodHandleDesc {
46
47 private final Kind kind;
48 private final ClassDesc owner;
49 private final String name;
50 private final MethodTypeDesc type;
51
52 /**
53 * Construct a {@linkplain DirectMethodHandleDescImpl} for a method or field
54 * from a kind, owner, name, and type
55 *
56 * @param kind the kind of the method handle
57 * @param owner the declaring class or interface for the method
58 * @param name the name of the method (ignored if {@code kind} is
59 * {@code CONSTRUCTOR}), as per JVMS 4.2.2
60 * @param type the type of the method
61 * @throws NullPointerException if any non-ignored argument is null
62 * @throws IllegalArgumentException if {@code kind} describes a field accessor,
63 * and {@code type} is not consistent with that kind of field accessor, or if
64 * {@code kind} describes a constructor, and the return type of {@code type}
65 * is not {@code void}
66 * @jvms 4.2.2 Unqualified Names
67 */
68 DirectMethodHandleDescImpl(Kind kind, ClassDesc owner, String name, MethodTypeDesc type) {
69 if (kind == CONSTRUCTOR)
70 name = "<init>";
71
72 requireNonNull(kind);
73 validateClassOrInterface(requireNonNull(owner));
74 validateMemberName(requireNonNull(name));
75 requireNonNull(type);
76
77 switch (kind) {
78 case CONSTRUCTOR: validateConstructor(type); break;
79 case GETTER: validateFieldType(type, false, true); break;
80 case SETTER: validateFieldType(type, true, true); break;
81 case STATIC_GETTER: validateFieldType(type, false, false); break;
82 case STATIC_SETTER: validateFieldType(type, true, false); break;
83 }
84
85 this.kind = kind;
86 this.owner = owner;
87 this.name = name;
88 this.type = type;
89 }
90
91 private static void validateFieldType(MethodTypeDesc type, boolean isSetter, boolean isVirtual) {
92 boolean isVoid = type.returnType().descriptorString().equals("V");
93 int expectedParams = (isSetter ? 1 : 0) + (isVirtual ? 1 : 0);
94 if (isVoid != isSetter
95 || type.parameterCount() != expectedParams
96 || (isVirtual && type.parameterType(0).isPrimitive())) {
97 String expectedType = String.format("(%s%s)%s", (isVirtual ? "R" : ""),
98 (isSetter ? "T" : ""), (isSetter ? "V" : "T"));
99 throw new IllegalArgumentException(String.format("Expected type of %s for getter, found %s", expectedType, type));
100 }
101 }
102
103 private static void validateConstructor(MethodTypeDesc type) {
104 if (!type.returnType().descriptorString().equals("V")) {
105 throw new IllegalArgumentException(String.format("Expected type of (T*)V for constructor, found %s", type));
106 }
107 }
108
109 @Override
110 public Kind kind() { return kind; }
111
112 @Override
113 public int refKind() { return kind.refKind; }
114
115 @Override
116 public boolean isOwnerInterface() { return kind.isInterface; }
117
118 @Override
119 public ClassDesc owner() {
120 return owner;
121 }
122
123 @Override
124 public String methodName() {
125 return name;
126 }
127
128 @Override
129 public MethodTypeDesc methodType() {
130 return type;
131 }
132
133 public MethodHandle resolveConstantDesc(MethodHandles.Lookup lookup)
134 throws ReflectiveOperationException {
135 Class<?> resolvedOwner = owner.resolveConstantDesc(lookup);
136 MethodType resolvedType = this.type.resolveConstantDesc(lookup);
137 switch (kind) {
138 case STATIC:
139 case INTERFACE_STATIC:
140 return lookup.findStatic(resolvedOwner, name, resolvedType);
141 case INTERFACE_VIRTUAL:
142 case VIRTUAL:
143 return lookup.findVirtual(resolvedOwner, name, resolvedType);
144 case SPECIAL:
145 case INTERFACE_SPECIAL:
146 return lookup.findSpecial(resolvedOwner, name, resolvedType, lookup.lookupClass());
147 case CONSTRUCTOR:
148 return lookup.findConstructor(resolvedOwner, resolvedType);
149 case GETTER:
150 return lookup.findGetter(resolvedOwner, name, resolvedType.returnType());
151 case STATIC_GETTER:
152 return lookup.findStaticGetter(resolvedOwner, name, resolvedType.returnType());
153 case SETTER:
154 return lookup.findSetter(resolvedOwner, name, resolvedType.parameterType(1));
155 case STATIC_SETTER:
156 return lookup.findStaticSetter(resolvedOwner, name, resolvedType.parameterType(0));
157 default:
158 throw new IllegalStateException(kind.name());
159 }
160 }
161
162 @Override
163 public Optional<? extends ConstantDesc<ConstantDesc<MethodHandle>>> describeConstable() {
164 return Optional.of(DynamicConstantDesc.ofSymbolic(this));
165 }
166
167 @Override
168 public boolean equals(Object o) {
169 if (this == o) return true;
170 if (o == null || getClass() != o.getClass()) return false;
171 DirectMethodHandleDescImpl desc = (DirectMethodHandleDescImpl) o;
172 return kind == desc.kind &&
173 Objects.equals(owner, desc.owner) &&
174 Objects.equals(name, desc.name) &&
175 Objects.equals(type, desc.type);
176 }
177
178 @Override
179 public int hashCode() {
180 return Objects.hash(kind, owner, name, type);
181 }
182
183 @Override
184 public String toString() {
185 return String.format("MethodHandleDesc[%s/%s::%s%s]", kind, owner.displayName(), name, type.displayDescriptor());
186 }
187 }