1 /* 2 * Copyright (c) 2024, 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.reflect.code.type; 27 28 import java.lang.constant.ClassDesc; 29 import java.lang.invoke.MethodHandles.Lookup; 30 import java.lang.reflect.Executable; 31 import java.lang.reflect.Type; 32 import java.lang.reflect.TypeVariable; 33 import java.util.List; 34 35 /** 36 * A type-variable reference. 37 */ 38 public final class TypeVarRef implements JavaType { 39 40 final String name; 41 final Owner owner; 42 final JavaType bound; 43 44 TypeVarRef(String name, Owner owner, JavaType bound) { 45 this.name = name; 46 this.owner = owner; 47 this.bound = bound; 48 } 49 50 @Override 51 public Type resolve(Lookup lookup) throws ReflectiveOperationException { 52 TypeVariable<?>[] typeVariables = switch (owner) { 53 case MethodRef methodRef -> { 54 Executable method = ((MethodRef)owner).resolveToMember(lookup); 55 yield method.getTypeParameters(); 56 } 57 case JavaType type -> { 58 Class<?> erasedDecl = (Class<?>)type.resolve(lookup); 59 yield erasedDecl.getTypeParameters(); 60 } 61 }; 62 for (TypeVariable<?> tv : typeVariables) { 63 if (tv.getName().equals(name)) { 64 return tv; 65 } 66 } 67 throw new ReflectiveOperationException("Type-variable not found: " + name); 68 } 69 70 /** 71 * {@return the type-variable name} 72 */ 73 public String name() { 74 return name; 75 } 76 77 /** 78 * {@return the type-variable bound} 79 */ 80 public JavaType bound() { 81 return bound; 82 } 83 84 /** 85 * {@return the owner of this type-variable} 86 */ 87 public Owner owner() { 88 return owner; 89 } 90 91 @Override 92 public JavaType erasure() { 93 return bound.erasure(); 94 } 95 96 @Override 97 public ExternalizedTypeElement externalize() { 98 return new ExternalizedTypeElement(String.format("#%s::%s", owner, name), 99 List.of(bound.externalize())); 100 } 101 102 @Override 103 public String toString() { 104 return externalize().toString(); 105 } 106 107 @Override 108 public boolean equals(Object o) { 109 if (this == o) return true; 110 return o instanceof TypeVarRef that && 111 name.equals(that.name) && 112 bound.equals(that.bound); 113 } 114 115 @Override 116 public int hashCode() { 117 return name.hashCode(); 118 } 119 120 @Override 121 public JavaType toBasicType() { 122 return erasure().toBasicType(); 123 } 124 125 @Override 126 public ClassDesc toNominalDescriptor() { 127 return erasure().toNominalDescriptor(); 128 } 129 130 /** 131 * The owner of a type-variable - either a class or a method. 132 */ 133 public sealed interface Owner permits ClassType, MethodRef { } 134 }