1 /*
2 * Copyright (c) 2022, 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 jdk.internal.value;
27
28 import jdk.internal.access.JavaLangAccess;
29 import jdk.internal.access.SharedSecrets;
30 import jdk.internal.vm.annotation.IntrinsicCandidate;
31
32 import java.lang.constant.ClassDesc;
33
34 /**
35 * Utilities to access Primitive Classes as described in JEP 401.
36 */
37 public class PrimitiveClass {
38
39 /**
40 * ACC_PRIMITIVE modifier defined by JEP 401. Subject to change.
41 */
42 public static final int PRIMITIVE_CLASS = 0x00000800;
43
44 private static final JavaLangAccess javaLangAccess = SharedSecrets.getJavaLangAccess();
45
46
47 /**
48 * Returns a {@code Class} object representing the primary type
49 * of this class or interface.
50 * <p>
51 * If this {@code Class} object represents a primitive type or an array type,
52 * then this method returns this class.
53 * <p>
54 * If this {@code Class} object represents a {@linkplain #isPrimitiveClass(Class)
55 * primitive class}, then this method returns the <em>primitive reference type</em>
56 * type of this primitive class.
57 * <p>
58 * Otherwise, this {@code Class} object represents a non-primitive class or interface
59 * and this method returns this class.
60 *
61 * @param aClass a class
62 * @return the {@code Class} representing the primary type of
63 * this class or interface
64 * @since Valhalla
65 */
66 @IntrinsicCandidate
67 public static Class<?> asPrimaryType(Class<?> aClass) {
68 return javaLangAccess.asPrimaryType(aClass);
69 }
70
71 /**
72 * Returns a {@code Class} object representing the <em>primitive value type</em>
73 * of this class if this class is a {@linkplain #isPrimitiveClass(Class)} primitive class}.
74 *
75 * @apiNote Alternatively, this method returns null if this class is not
76 * a primitive class rather than throwing UOE.
77 *
78 * @param aClass a class
79 * @return the {@code Class} representing the {@linkplain #isPrimitiveValueType(Class)
80 * primitive value type} of this class if this class is a primitive class
81 * @throws UnsupportedOperationException if this class or interface
82 * is not a primitive class
83 * @since Valhalla
84 */
85 @SuppressWarnings("unchecked")
86 @IntrinsicCandidate
87 public static Class<?> asValueType(Class<?> aClass) {
88 return javaLangAccess.asValueType(aClass);
89 }
90
91 /**
92 * Returns {@code true} if this {@code Class} object represents the primary type
93 * of this class or interface.
94 * <p>
95 * If this {@code Class} object represents a primitive type or an array type,
96 * then this method returns {@code true}.
97 * <p>
98 * If this {@code Class} object represents a {@linkplain #isPrimitiveClass(Class)
99 * primitive}, then this method returns {@code true} if this {@code Class}
100 * object represents a primitive reference type, or returns {@code false}
101 * if this {@code Class} object represents a primitive value type.
102 * <p>
103 * If this {@code Class} object represents a non-primitive class or interface,
104 * then this method returns {@code true}.
105 *
106 * @param aClass a class
107 * @return {@code true} if this {@code Class} object represents
108 * the primary type of this class or interface
109 * @since Valhalla
110 */
111 public static boolean isPrimaryType(Class<?> aClass) {
112 return javaLangAccess.isPrimaryType(aClass);
113 }
114
115 /**
116 * Returns {@code true} if this {@code Class} object represents
117 * a {@linkplain #isPrimitiveClass(Class) primitive} value type.
118 *
119 * @return {@code true} if this {@code Class} object represents
120 * the value type of a primitive class
121 * @since Valhalla
122 */
123 public static boolean isPrimitiveValueType(Class<?> aClass) {
124 return javaLangAccess.isPrimitiveValueType(aClass);
125 }
126
127 /**
128 * Returns {@code true} if this class is a primitive class.
129 * <p>
130 * Each primitive class has a {@linkplain #isPrimaryType(Class) primary type}
131 * representing the <em>primitive reference type</em> and a
132 * {@linkplain #isPrimitiveValueType(Class) secondary type} representing
133 * the <em>primitive value type</em>. The primitive reference type
134 * and primitive value type can be obtained by calling the
135 * {@link #asPrimaryType(Class)} and {@link PrimitiveClass#asValueType} method
136 * of a primitive class respectively.
137 * <p>
138 * A primitive class is a {@linkplain Class#isValue() value class}.
139 *
140 * @param aClass a class
141 * @return {@code true} if this class is a primitive class, otherwise {@code false}
142 * @see Class#isValue()
143 * @see #asPrimaryType(Class)
144 * @see #asValueType(Class)
145 * @since Valhalla
146 */
147 public static boolean isPrimitiveClass(Class<?> aClass) {
148 return javaLangAccess.isPrimitiveClass(aClass);
149 }
150
151 /**
152 * Returns whether this {@linkplain ClassDesc} describes a
153 * {@linkplain #isPrimitiveValueType(Class)} primitive value type}.
154 *
155 * @return whether this {@linkplain ClassDesc} describes a primitive value type.
156 * @since Valhalla
157 */
158 public static boolean isPrimitiveValueClassDesc(ClassDesc classDesc) {
159 return classDesc.descriptorString().startsWith("Q");
160 }
161 }