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.MethodHandles;
28 import java.lang.invoke.MethodType;
29 import java.util.Arrays;
30 import java.util.List;
31 import java.util.Optional;
32
33 import static java.lang.constant.ConstantDescs.BSM_INVOKE;
34 import static java.lang.constant.ConstantDescs.MHR_METHODTYPEDESC_FACTORY;
35 import static java.util.Objects.requireNonNull;
36
37 /**
38 * A <a href="package-summary.html#nominal">nominal descriptor</a> for a
39 * {@link MethodType}. A {@linkplain MethodTypeDescImpl} corresponds to a
40 * {@code Constant_MethodType_info} entry in the constant pool of a classfile.
41 */
42 final class MethodTypeDescImpl implements MethodTypeDesc {
43 private final ClassDesc returnType;
44 private final ClassDesc[] argTypes;
45
46 /**
47 * Construct a {@linkplain MethodTypeDesc} with the specified return type
48 * and parameter types
49 *
50 * @param returnType a {@link ClassDesc} describing the return type
51 * @param argTypes {@link ClassDesc}s describing the parameter types
52 */
53 MethodTypeDescImpl(ClassDesc returnType, ClassDesc[] argTypes) {
54 this.returnType = requireNonNull(returnType);
55 this.argTypes = requireNonNull(argTypes);
56
57 for (ClassDesc cr : argTypes)
58 if (cr.isPrimitive() && cr.descriptorString().equals("V"))
59 throw new IllegalArgumentException("Void parameters not permitted");
60 }
61
62 /**
63 * Create a {@linkplain MethodTypeDescImpl} given a method descriptor string.
64 *
65 * @param descriptor the method descriptor string, as per JVMS 4.3.3
66 * @return a {@linkplain MethodTypeDescImpl} describing the desired method type
67 * @throws IllegalArgumentException if the descriptor string is not a valid
68 * method descriptor
69 * @jvms 4.3.3 Method Descriptors
70 */
71 static MethodTypeDescImpl ofDescriptor(String descriptor) {
72 requireNonNull(descriptor);
73 List<String> types = ConstantUtils.parseMethodDescriptor(descriptor);
74 ClassDesc[] paramTypes = types.stream().skip(1).map(ClassDesc::ofDescriptor).toArray(ClassDesc[]::new);
75 return new MethodTypeDescImpl(ClassDesc.ofDescriptor(types.get(0)), paramTypes);
76 }
77
78 @Override
79 public ClassDesc returnType() {
80 return returnType;
81 }
82
83 @Override
84 public int parameterCount() {
85 return argTypes.length;
86 }
87
88 @Override
89 public ClassDesc parameterType(int index) {
90 return argTypes[index];
91 }
92
93 @Override
94 public List<ClassDesc> parameterList() {
95 return List.of(argTypes);
96 }
97
98 @Override
99 public ClassDesc[] parameterArray() {
100 return argTypes.clone();
101 }
102
103 @Override
104 public MethodTypeDesc changeReturnType(ClassDesc returnType) {
105 return MethodTypeDesc.of(returnType, argTypes);
106 }
107
108 @Override
109 public MethodTypeDesc changeParameterType(int index, ClassDesc paramType) {
110 ClassDesc[] newArgs = argTypes.clone();
111 newArgs[index] = paramType;
112 return MethodTypeDesc.of(returnType, newArgs);
113 }
114
115 @Override
116 public MethodTypeDesc dropParameterTypes(int start, int end) {
117 if (start < 0 || start >= argTypes.length || end < 0 || end > argTypes.length)
118 throw new IndexOutOfBoundsException();
119 else if (start > end)
120 throw new IllegalArgumentException(String.format("Range (%d, %d) not valid for size %d", start, end, argTypes.length));
121 ClassDesc[] newArgs = new ClassDesc[argTypes.length - (end - start)];
122 System.arraycopy(argTypes, 0, newArgs, 0, start);
123 System.arraycopy(argTypes, end, newArgs, start, argTypes.length - end);
124 return MethodTypeDesc.of(returnType, newArgs);
125 }
126
127 @Override
128 public MethodTypeDesc insertParameterTypes(int pos, ClassDesc... paramTypes) {
129 if (pos < 0 || pos > argTypes.length)
130 throw new IndexOutOfBoundsException(pos);
131 ClassDesc[] newArgs = new ClassDesc[argTypes.length + paramTypes.length];
132 System.arraycopy(argTypes, 0, newArgs, 0, pos);
133 System.arraycopy(paramTypes, 0, newArgs, pos, paramTypes.length);
134 System.arraycopy(argTypes, pos, newArgs, pos+paramTypes.length, argTypes.length - pos);
135 return MethodTypeDesc.of(returnType, newArgs);
136 }
137
138 @Override
139 public MethodType resolveConstantDesc(MethodHandles.Lookup lookup) {
140 return MethodType.fromMethodDescriptorString(descriptorString(), lookup.lookupClass().getClassLoader());
141 }
142
143 @Override
144 public Optional<? extends ConstantDesc<ConstantDesc<MethodType>>> describeConstable() {
145 return Optional.of(DynamicConstantDesc.of(BSM_INVOKE, MHR_METHODTYPEDESC_FACTORY, descriptorString()));
146 }
147
148 @Override
149 public boolean equals(Object o) {
150 if (this == o) return true;
151 if (o == null || getClass() != o.getClass()) return false;
152
153 MethodTypeDescImpl constant = (MethodTypeDescImpl) o;
154
155 return returnType.equals(constant.returnType)
156 && Arrays.equals(argTypes, constant.argTypes);
157 }
158
159 @Override
160 public int hashCode() {
161 int result = returnType.hashCode();
162 result = 31 * result + Arrays.hashCode(argTypes);
163 return result;
164 }
165
166 @Override
167 public String toString() {
168 return String.format("MethodTypeDesc[%s]", displayDescriptor());
169 }
170 }