1 /* 2 * Copyright (c) 2015, 2017, 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.misc.JavaLangInvokeAccess; 28 import jdk.internal.misc.SharedSecrets; 29 30 import static java.lang.StackWalker.Option.*; 31 import java.lang.StackWalker.StackFrame; 32 import java.lang.invoke.MethodType; 33 34 class StackFrameInfo implements StackFrame { 35 private final byte RETAIN_CLASS_REF = 0x01; 36 37 private final static JavaLangInvokeAccess JLIA = 38 SharedSecrets.getJavaLangInvokeAccess(); 39 40 private final byte flags; 41 private final Object memberName; 42 private final short bci; 43 private volatile StackTraceElement ste; 44 45 /* 46 * Create StackFrameInfo for StackFrameTraverser and LiveStackFrameTraverser 47 * to use 48 */ 49 StackFrameInfo(StackWalker walker) { 50 this.flags = walker.retainClassRef ? RETAIN_CLASS_REF : 0; 51 this.bci = -1; 52 this.memberName = JLIA.newMemberName(); 53 } 54 55 // package-private called by StackStreamFactory to skip 56 // the capability check 57 Class<?> declaringClass() { 58 return JLIA.getDeclaringClass(memberName); 59 } 60 61 // ----- implementation of StackFrame methods 62 63 @Override 64 public String getClassName() { 65 return declaringClass().getName(); 66 } 67 68 @Override 69 public Class<?> getDeclaringClass() { 70 ensureRetainClassRefEnabled(); 71 return declaringClass(); 72 } 73 74 @Override 75 public String getMethodName() { 76 return JLIA.getName(memberName); 77 } 78 79 @Override 80 public MethodType getMethodType() { 81 ensureRetainClassRefEnabled(); 82 return JLIA.getMethodType(memberName); 83 } 84 85 @Override 86 public String getDescriptor() { 87 return JLIA.getMethodDescriptor(memberName); 88 } 89 90 @Override 91 public int getByteCodeIndex() { 92 // bci not available for native methods 93 if (isNativeMethod()) 94 return -1; 95 96 return bci; 97 } 98 99 @Override 100 public String getFileName() { 101 return toStackTraceElement().getFileName(); 102 } 103 104 @Override 105 public int getLineNumber() { 106 // line number not available for native methods 107 if (isNativeMethod()) 108 return -2; 109 110 return toStackTraceElement().getLineNumber(); 111 } 112 113 114 @Override 115 public boolean isNativeMethod() { 116 return JLIA.isNative(memberName); 117 } 118 119 @Override 120 public String toString() { 121 return toStackTraceElement().toString(); 122 } 123 124 @Override 125 public StackTraceElement toStackTraceElement() { 126 StackTraceElement s = ste; 127 if (s == null) { 128 synchronized (this) { 129 s = ste; 130 if (s == null) { 131 ste = s = StackTraceElement.of(this); 132 } 133 } 134 } 135 return s; 136 } 137 138 private void ensureRetainClassRefEnabled() { 139 if ((flags & RETAIN_CLASS_REF) == 0) { 140 throw new UnsupportedOperationException("No access to RETAIN_CLASS_REFERENCE"); 141 } 142 } 143 }