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