1 /* 2 * Copyright (c) 2015, 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; 26 27 import jdk.internal.access.JavaLangInvokeAccess; 28 import jdk.internal.access.SharedSecrets; 29 30 import java.lang.StackWalker.StackFrame; 31 import java.lang.invoke.MethodType; 32 33 class StackFrameInfo implements StackFrame { 34 private final byte RETAIN_CLASS_REF = 0x01; 35 36 private final static JavaLangInvokeAccess JLIA = 37 SharedSecrets.getJavaLangInvokeAccess(); 38 39 private final byte flags; 40 private final Object memberName; 41 private final short bci; 42 private volatile StackTraceElement ste; 43 44 /* 45 * Create StackFrameInfo for StackFrameTraverser and LiveStackFrameTraverser 46 * to use 47 */ 48 StackFrameInfo(StackWalker walker) { 49 this.flags = walker.retainClassRef ? RETAIN_CLASS_REF : 0; 50 this.bci = -1; 51 this.memberName = JLIA.newMemberName(); 52 } 53 54 // package-private called by StackStreamFactory to skip 55 // the capability check 56 Class<?> declaringClass() { 57 return JLIA.getDeclaringClass(memberName); 58 } 59 60 // ----- implementation of StackFrame methods 61 62 @Override 63 public String getClassName() { 64 return declaringClass().getName(); 65 } 66 67 @Override 68 public Class<?> getDeclaringClass() { 69 ensureRetainClassRefEnabled(); 70 return declaringClass(); 71 } 72 73 @Override 74 public String getMethodName() { 75 return JLIA.getName(memberName); 76 } 77 78 @Override 79 public MethodType getMethodType() { 80 ensureRetainClassRefEnabled(); 81 return JLIA.getMethodType(memberName); 82 } 83 84 @Override 85 public String getDescriptor() { 86 return JLIA.getMethodDescriptor(memberName); 87 } 88 89 @Override 90 public int getByteCodeIndex() { 91 // bci not available for native methods 92 if (isNativeMethod()) 93 return -1; 94 95 return bci; 96 } 97 98 @Override 99 public String getFileName() { 100 return toStackTraceElement().getFileName(); 101 } 102 103 @Override 104 public int getLineNumber() { 105 // line number not available for native methods 106 if (isNativeMethod()) 107 return -2; 108 109 return toStackTraceElement().getLineNumber(); 110 } 111 112 113 @Override 114 public boolean isNativeMethod() { 115 return JLIA.isNative(memberName); 116 } 117 118 @Override 119 public String toString() { 120 return toStackTraceElement().toString(); 121 } 122 123 @Override 124 public StackTraceElement toStackTraceElement() { 125 StackTraceElement s = ste; 126 if (s == null) { 127 synchronized (this) { 128 s = ste; 129 if (s == null) { 130 ste = s = StackTraceElement.of(this); 131 } 132 } 133 } 134 return s; 135 } 136 137 private void ensureRetainClassRefEnabled() { 138 if ((flags & RETAIN_CLASS_REF) == 0) { 139 throw new UnsupportedOperationException("No access to RETAIN_CLASS_REFERENCE"); 140 } 141 } 142 }