1 /* 2 * Copyright (c) 2007, 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. 8 * 9 * This code is distributed in the hope that it will be useful, but WITHOUT 10 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 11 * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 12 * version 2 for more details (a copy is included in the LICENSE file that 13 * accompanied this code). 14 * 15 * You should have received a copy of the GNU General Public License version 16 * 2 along with this work; if not, write to the Free Software Foundation, 17 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. 18 * 19 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA 20 * or visit www.oracle.com if you need additional information or have any 21 * questions. 22 */ 23 package vm.share.stack; 24 25 import java.util.List; 26 import java.util.Map; 27 28 import nsk.share.TestFailure; 29 import nsk.share.log.Log; 30 31 public final class StackUtils { StackUtils()32 private StackUtils() { 33 } 34 replace(String s)35 private static String replace(String s) { 36 return (s == null || s.length() == 0) ? "?" : s; 37 } 38 39 /** 40 * String representation of stack trace element. 41 * 42 * Note that null and empty values are replaced with '?'. 43 */ strStackTraceElement(StackTraceElement element)44 public static String strStackTraceElement(StackTraceElement element) { 45 return "at " + replace(element.getClassName()) + "." + replace(element.getMethodName()) + "(" + replace(element.getFileName()) + ":" + element.getLineNumber() + ")"; 46 } 47 printStackTraceElement(Log log, StackTraceElement element)48 public static void printStackTraceElement(Log log, StackTraceElement element) { 49 log.info(" " + strStackTraceElement(element)); 50 } 51 printStackTrace(Log log, StackTraceElement[] elements)52 public static void printStackTrace(Log log, StackTraceElement[] elements) { 53 for (StackTraceElement element : elements) 54 printStackTraceElement(log, element); 55 } 56 printStackTrace(Log log, Iterable<StackTraceElement> elements)57 public static void printStackTrace(Log log, Iterable<StackTraceElement> elements) { 58 for (StackTraceElement element : elements) 59 printStackTraceElement(log, element); 60 } 61 62 /** 63 * Check that element matches expected element. 64 * 65 * Expected element is used as pattern for matching. A null or empty 66 * field value means that no comparison is done. 67 */ matches(StackTraceElement element, StackTraceElement expected)68 public static boolean matches(StackTraceElement element, StackTraceElement expected) { 69 return 70 (expected.getClassName() == null || expected.getClassName().length() == 0 || expected.getClassName().equals(element.getClassName())) && 71 (expected.getMethodName() == null || expected.getMethodName().length() == 0 || expected.getMethodName().equals(element.getMethodName())) && 72 (expected.isNativeMethod() == element.isNativeMethod()); 73 } 74 expectedTraceElement(String className, String methodName, boolean nativeMethod)75 public static StackTraceElement expectedTraceElement(String className, String methodName, boolean nativeMethod) { 76 // Replace null className with empty because StackTraceElement constructor does not allow null className. 77 return new StackTraceElement(className == null ? "" : className, methodName, null, (nativeMethod ? -2 : 0)); 78 } 79 addExpectedTraceElement(List<StackTraceElement> expectedTrace, String className, String methodName, boolean nativeMethod)80 public static void addExpectedTraceElement(List<StackTraceElement> expectedTrace, String className, String methodName, boolean nativeMethod) { 81 expectedTrace.add(0, expectedTraceElement(className, methodName, nativeMethod)); 82 } 83 84 /** 85 * Check that trace elements starting from given index match expected elements. 86 */ checkMatches(StackTraceElement[] elements, List<StackTraceElement> expectedTrace, int i)87 public static void checkMatches(StackTraceElement[] elements, List<StackTraceElement> expectedTrace, int i) { 88 if (elements.length - i < expectedTrace.size()) 89 throw new TestFailure("Expected at least " + expectedTrace.size() + " trace elements, got only " + (i + 1)); 90 for (int j = 0; j < expectedTrace.size(); ++j) { 91 StackTraceElement expected = expectedTrace.get((expectedTrace.size() - 1) - j); 92 int index = (elements.length - 1) - i - j; 93 StackTraceElement actual = elements[index]; 94 if (!matches(actual, expected)) 95 throw new TestFailure("Expected element at index " + index + " to match: " + strStackTraceElement(expected)); 96 } 97 } 98 99 /** 100 * Find matching stack trace element starting from top of the stack. 101 */ findMatch(StackTraceElement[] elements, StackTraceElement expected)102 public static int findMatch(StackTraceElement[] elements, StackTraceElement expected) { 103 for (int i = 0; i < elements.length; ++i) 104 if (StackUtils.matches(elements[elements.length - 1 - i], expected)) 105 return i; 106 return -1; 107 } 108 109 /** 110 * Find the stack trace element that contains the "main(String[])" method 111 * 112 * @return StackTraceElement containing "main" function, null if there are more than one 113 */ findMain()114 public static StackTraceElement findMain() { 115 Map<Thread, StackTraceElement[]> stackTraces = Thread.getAllStackTraces(); 116 StackTraceElement mainMethodFrame = null; 117 for(StackTraceElement[] current : stackTraces.values()) { 118 if (current.length > 0) { 119 StackTraceElement last = current[current.length - 1]; 120 if ("main".equals(last.getMethodName())) { 121 if (mainMethodFrame == null) { 122 mainMethodFrame = last; 123 } else if (!mainMethodFrame.getClassName().equals(last.getClassName())) { 124 // more than one class has a "main" 125 return null; 126 } 127 } 128 } 129 } 130 return mainMethodFrame; 131 } 132 } 133