| /* |
| * Copyright (c) 2000, 2016, Oracle and/or its affiliates. All rights reserved. |
| * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. |
| * |
| * This code is free software; you can redistribute it and/or modify it |
| * under the terms of the GNU General Public License version 2 only, as |
| * published by the Free Software Foundation. Oracle designates this |
| * particular file as subject to the "Classpath" exception as provided |
| * by Oracle in the LICENSE file that accompanied this code. |
| * |
| * This code is distributed in the hope that it will be useful, but WITHOUT |
| * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or |
| * FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License |
| * version 2 for more details (a copy is included in the LICENSE file that |
| * accompanied this code). |
| * |
| * You should have received a copy of the GNU General Public License version |
| * 2 along with this work; if not, write to the Free Software Foundation, |
| * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA. |
| * |
| * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA |
| * or visit www.oracle.com if you need additional information or have any |
| * questions. |
| */ |
| |
| package java.lang; |
| |
| import jdk.internal.loader.BuiltinClassLoader; |
| import jdk.internal.misc.VM; |
| import jdk.internal.module.ModuleHashes; |
| import jdk.internal.module.ModuleReferenceImpl; |
| |
| import java.lang.module.ModuleDescriptor.Version; |
| import java.lang.module.ModuleReference; |
| import java.lang.module.ResolvedModule; |
| import java.lang.reflect.Layer; |
| import java.lang.reflect.Module; |
| import java.util.HashSet; |
| import java.util.Objects; |
| import java.util.Optional; |
| import java.util.Set; |
| |
| /** |
| * An element in a stack trace, as returned by {@link |
| * Throwable#getStackTrace()}. Each element represents a single stack frame. |
| * All stack frames except for the one at the top of the stack represent |
| * a method invocation. The frame at the top of the stack represents the |
| * execution point at which the stack trace was generated. Typically, |
| * this is the point at which the throwable corresponding to the stack trace |
| * was created. |
| * |
| * @since 1.4 |
| * @author Josh Bloch |
| */ |
| public final class StackTraceElement implements java.io.Serializable { |
| |
| // For Throwables and StackWalker, the VM initially sets this field to a |
| // reference to the declaring Class. The Class reference is used to |
| // construct the 'format' bitmap, and then is cleared. |
| // |
| // For STEs constructed using the public constructors, this field is not used. |
| private transient Class<?> declaringClassObject; |
| |
| // Normally initialized by VM |
| private String classLoaderName; |
| private String moduleName; |
| private String moduleVersion; |
| private String declaringClass; |
| private String methodName; |
| private String fileName; |
| private int lineNumber; |
| private byte format = 0; // Default to show all |
| |
| /** |
| * Creates a stack trace element representing the specified execution |
| * point. The {@link #getModuleName module name} and {@link |
| * #getModuleVersion module version} of the stack trace element will |
| * be {@code null}. |
| * |
| * @param declaringClass the fully qualified name of the class containing |
| * the execution point represented by the stack trace element |
| * @param methodName the name of the method containing the execution point |
| * represented by the stack trace element |
| * @param fileName the name of the file containing the execution point |
| * represented by the stack trace element, or {@code null} if |
| * this information is unavailable |
| * @param lineNumber the line number of the source line containing the |
| * execution point represented by this stack trace element, or |
| * a negative number if this information is unavailable. A value |
| * of -2 indicates that the method containing the execution point |
| * is a native method |
| * @throws NullPointerException if {@code declaringClass} or |
| * {@code methodName} is null |
| * @since 1.5 |
| */ |
| public StackTraceElement(String declaringClass, String methodName, |
| String fileName, int lineNumber) { |
| this(null, null, null, declaringClass, methodName, fileName, lineNumber); |
| } |
| |
| /** |
| * Creates a stack trace element representing the specified execution |
| * point. |
| * |
| * @param classLoaderName the class loader name if the class loader of |
| * the class containing the execution point represented by |
| * the stack trace is named; otherwise {@code null} |
| * @param moduleName the module name if the class containing the |
| * execution point represented by the stack trace is in a named |
| * module; otherwise {@code null} |
| * @param moduleVersion the module version if the class containing the |
| * execution point represented by the stack trace is in a named |
| * module that has a version; otherwise {@code null} |
| * @param declaringClass the fully qualified name of the class containing |
| * the execution point represented by the stack trace element |
| * @param methodName the name of the method containing the execution point |
| * represented by the stack trace element |
| * @param fileName the name of the file containing the execution point |
| * represented by the stack trace element, or {@code null} if |
| * this information is unavailable |
| * @param lineNumber the line number of the source line containing the |
| * execution point represented by this stack trace element, or |
| * a negative number if this information is unavailable. A value |
| * of -2 indicates that the method containing the execution point |
| * is a native method |
| * |
| * @throws NullPointerException if {@code declaringClass} is {@code null} |
| * or {@code methodName} is {@code null} |
| * |
| * @since 9 |
| */ |
| public StackTraceElement(String classLoaderName, |
| String moduleName, String moduleVersion, |
| String declaringClass, String methodName, |
| String fileName, int lineNumber) { |
| this.classLoaderName = classLoaderName; |
| this.moduleName = moduleName; |
| this.moduleVersion = moduleVersion; |
| this.declaringClass = Objects.requireNonNull(declaringClass, "Declaring class is null"); |
| this.methodName = Objects.requireNonNull(methodName, "Method name is null"); |
| this.fileName = fileName; |
| this.lineNumber = lineNumber; |
| } |
| |
| /* |
| * Private constructor for the factory methods to create StackTraceElement |
| * for Throwable and StackFrameInfo |
| */ |
| private StackTraceElement() {} |
| |
| /** |
| * Returns the name of the source file containing the execution point |
| * represented by this stack trace element. Generally, this corresponds |
| * to the {@code SourceFile} attribute of the relevant {@code class} |
| * file (as per <i>The Java Virtual Machine Specification</i>, Section |
| * 4.7.7). In some systems, the name may refer to some source code unit |
| * other than a file, such as an entry in source repository. |
| * |
| * @return the name of the file containing the execution point |
| * represented by this stack trace element, or {@code null} if |
| * this information is unavailable. |
| */ |
| public String getFileName() { |
| return fileName; |
| } |
| |
| /** |
| * Returns the line number of the source line containing the execution |
| * point represented by this stack trace element. Generally, this is |
| * derived from the {@code LineNumberTable} attribute of the relevant |
| * {@code class} file (as per <i>The Java Virtual Machine |
| * Specification</i>, Section 4.7.8). |
| * |
| * @return the line number of the source line containing the execution |
| * point represented by this stack trace element, or a negative |
| * number if this information is unavailable. |
| */ |
| public int getLineNumber() { |
| return lineNumber; |
| } |
| |
| /** |
| * Returns the module name of the module containing the execution point |
| * represented by this stack trace element. |
| * |
| * @return the module name of the {@code Module} containing the execution |
| * point represented by this stack trace element; {@code null} |
| * if the module name is not available. |
| * @since 9 |
| * @see java.lang.reflect.Module#getName() |
| */ |
| public String getModuleName() { |
| return moduleName; |
| } |
| |
| /** |
| * Returns the module version of the module containing the execution point |
| * represented by this stack trace element. |
| * |
| * @return the module version of the {@code Module} containing the execution |
| * point represented by this stack trace element; {@code null} |
| * if the module version is not available. |
| * @since 9 |
| * @see java.lang.module.ModuleDescriptor.Version |
| */ |
| public String getModuleVersion() { |
| return moduleVersion; |
| } |
| |
| /** |
| * Returns the name of the class loader of the class containing the |
| * execution point represented by this stack trace element. |
| * |
| * @return the name of the class loader of the class containing the execution |
| * point represented by this stack trace element; {@code null} |
| * if the class loader is not named. |
| * |
| * @since 9 |
| * @see java.lang.ClassLoader#getName() |
| */ |
| public String getClassLoaderName() { |
| return classLoaderName; |
| } |
| |
| /** |
| * Returns the fully qualified name of the class containing the |
| * execution point represented by this stack trace element. |
| * |
| * @return the fully qualified name of the {@code Class} containing |
| * the execution point represented by this stack trace element. |
| */ |
| public String getClassName() { |
| return declaringClass; |
| } |
| |
| /** |
| * Returns the name of the method containing the execution point |
| * represented by this stack trace element. If the execution point is |
| * contained in an instance or class initializer, this method will return |
| * the appropriate <i>special method name</i>, {@code <init>} or |
| * {@code <clinit>}, as per Section 3.9 of <i>The Java Virtual |
| * Machine Specification</i>. |
| * |
| * @return the name of the method containing the execution point |
| * represented by this stack trace element. |
| */ |
| public String getMethodName() { |
| return methodName; |
| } |
| |
| /** |
| * Returns true if the method containing the execution point |
| * represented by this stack trace element is a native method. |
| * |
| * @return {@code true} if the method containing the execution point |
| * represented by this stack trace element is a native method. |
| */ |
| public boolean isNativeMethod() { |
| return lineNumber == -2; |
| } |
| |
| /** |
| * Returns a string representation of this stack trace element. |
| * |
| * @apiNote The format of this string depends on the implementation, but the |
| * following examples may be regarded as typical: |
| * <ul> |
| * <li> |
| * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java:101)}" |
| * - See the description below. |
| * </li> |
| * <li> |
| * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Main.java)}" |
| * - The line number is unavailable. |
| * </li> |
| * <li> |
| * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Unknown Source)}" |
| * - Neither the file name nor the line number is available. |
| * </li> |
| * <li> |
| * "{@code com.foo.loader/foo@9.0/com.foo.Main.run(Native Method)}" |
| * - The method containing the execution point is a native method. |
| * </li> |
| * <li> |
| * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}" |
| * - The class of the execution point is defined in the unnamed module of |
| * the class loader named {@code com.foo.loader}. |
| * </li> |
| * <li> |
| * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}" |
| * - The class of the execution point is defined in {@code acme} module |
| * loaded by by a built-in class loader such as the application class loader. |
| * </li> |
| * <li> |
| * "{@code MyClass.mash(MyClass.java:9)}" |
| * - {@code MyClass} class is on the application class path. |
| * </li> |
| * </ul> |
| * |
| * <p> The first example shows a stack trace element consisting of |
| * three elements, each separated by {@code "/"} followed with |
| * the source file name and the line number of the source line |
| * containing the execution point. |
| * |
| * The first element "{@code com.foo.loader}" is |
| * the name of the class loader. The second element "{@code foo@9.0}" |
| * is the module name and version. The third element is the method |
| * containing the execution point; "{@code com.foo.Main"}" is the |
| * fully-qualified class name and "{@code run}" is the name of the method. |
| * "{@code Main.java}" is the source file name and "{@code 101}" is |
| * the line number. |
| * |
| * <p> If a class is defined in an <em>unnamed module</em> |
| * then the second element is omitted as shown in |
| * "{@code com.foo.loader//com.foo.bar.App.run(App.java:12)}". |
| * |
| * <p> If the class loader is a <a href="ClassLoader.html#builtinLoaders"> |
| * built-in class loader</a> or is not named then the first element |
| * and its following {@code "/"} are omitted as shown in |
| * "{@code acme@2.1/org.acme.Lib.test(Lib.java:80)}". |
| * If the first element is omitted and the module is an unnamed module, |
| * the second element and its following {@code "/"} are also omitted |
| * as shown in "{@code MyClass.mash(MyClass.java:9)}". |
| * |
| * <p> The {@code toString} method may return two different values on two |
| * {@code StackTraceElement} instances that are |
| * {@linkplain #equals(Object) equal}, for example one created via the |
| * constructor, and one obtained from {@link java.lang.Throwable} or |
| * {@link java.lang.StackWalker.StackFrame}, where an implementation may |
| * choose to omit some element in the returned string. |
| * |
| * @see Throwable#printStackTrace() |
| */ |
| public String toString() { |
| String s = ""; |
| if (!dropClassLoaderName() && classLoaderName != null && |
| !classLoaderName.isEmpty()) { |
| s += classLoaderName + "/"; |
| } |
| if (moduleName != null && !moduleName.isEmpty()) { |
| s += moduleName; |
| |
| if (!dropModuleVersion() && moduleVersion != null && |
| !moduleVersion.isEmpty()) { |
| s += "@" + moduleVersion; |
| } |
| } |
| s = s.isEmpty() ? declaringClass : s + "/" + declaringClass; |
| |
| return s + "." + methodName + "(" + |
| (isNativeMethod() ? "Native Method)" : |
| (fileName != null && lineNumber >= 0 ? |
| fileName + ":" + lineNumber + ")" : |
| (fileName != null ? ""+fileName+")" : "Unknown Source)"))); |
| } |
| |
| /** |
| * Returns true if the specified object is another |
| * {@code StackTraceElement} instance representing the same execution |
| * point as this instance. Two stack trace elements {@code a} and |
| * {@code b} are equal if and only if: |
| * <pre>{@code |
| * equals(a.getClassLoaderName(), b.getClassLoaderName()) && |
| * equals(a.getModuleName(), b.getModuleName()) && |
| * equals(a.getModuleVersion(), b.getModuleVersion()) && |
| * equals(a.getClassName(), b.getClassName()) && |
| * equals(a.getMethodName(), b.getMethodName()) |
| * equals(a.getFileName(), b.getFileName()) && |
| * a.getLineNumber() == b.getLineNumber() |
| * |
| * }</pre> |
| * where {@code equals} has the semantics of {@link |
| * java.util.Objects#equals(Object, Object) Objects.equals}. |
| * |
| * @param obj the object to be compared with this stack trace element. |
| * @return true if the specified object is another |
| * {@code StackTraceElement} instance representing the same |
| * execution point as this instance. |
| */ |
| public boolean equals(Object obj) { |
| if (obj==this) |
| return true; |
| if (!(obj instanceof StackTraceElement)) |
| return false; |
| StackTraceElement e = (StackTraceElement)obj; |
| return Objects.equals(classLoaderName, e.classLoaderName) && |
| Objects.equals(moduleName, e.moduleName) && |
| Objects.equals(moduleVersion, e.moduleVersion) && |
| e.declaringClass.equals(declaringClass) && |
| e.lineNumber == lineNumber && |
| Objects.equals(methodName, e.methodName) && |
| Objects.equals(fileName, e.fileName); |
| } |
| |
| /** |
| * Returns a hash code value for this stack trace element. |
| */ |
| public int hashCode() { |
| int result = 31*declaringClass.hashCode() + methodName.hashCode(); |
| result = 31*result + Objects.hashCode(classLoaderName); |
| result = 31*result + Objects.hashCode(moduleName); |
| result = 31*result + Objects.hashCode(moduleVersion); |
| result = 31*result + Objects.hashCode(fileName); |
| result = 31*result + lineNumber; |
| return result; |
| } |
| |
| |
| /** |
| * Called from of() methods to set the 'format' bitmap using the Class |
| * reference stored in declaringClassObject, and then clear the reference. |
| * |
| * <p> |
| * If the module is a non-upgradeable JDK module, then set |
| * JDK_NON_UPGRADEABLE_MODULE to omit its version string. |
| * <p> |
| * If the loader is one of the built-in loaders (`boot`, `platform`, or `app`) |
| * then set BUILTIN_CLASS_LOADER to omit the first element (`<loader>/`). |
| */ |
| private synchronized void computeFormat() { |
| try { |
| Class<?> cls = (Class<?>) declaringClassObject; |
| ClassLoader loader = cls.getClassLoader0(); |
| Module m = cls.getModule(); |
| byte bits = 0; |
| |
| // First element - class loader name |
| // Call package-private ClassLoader::name method |
| |
| if (loader instanceof BuiltinClassLoader) { |
| bits |= BUILTIN_CLASS_LOADER; |
| } |
| |
| // Second element - module name and version |
| |
| // Omit if is a JDK non-upgradeable module (recorded in the hashes |
| // in java.base) |
| if (isHashedInJavaBase(m)) { |
| bits |= JDK_NON_UPGRADEABLE_MODULE; |
| } |
| format = bits; |
| } finally { |
| // Class reference no longer needed, clear it |
| declaringClassObject = null; |
| } |
| } |
| |
| private static final byte BUILTIN_CLASS_LOADER = 0x1; |
| private static final byte JDK_NON_UPGRADEABLE_MODULE = 0x2; |
| |
| private boolean dropClassLoaderName() { |
| return (format & BUILTIN_CLASS_LOADER) == BUILTIN_CLASS_LOADER; |
| } |
| |
| private boolean dropModuleVersion() { |
| return (format & JDK_NON_UPGRADEABLE_MODULE) == JDK_NON_UPGRADEABLE_MODULE; |
| } |
| |
| /** |
| * Returns true if the module is hashed with java.base. |
| * <p> |
| * This method returns false when running on the exploded image |
| * since JDK modules are not hashed. They have no Version attribute |
| * and so "@<version>" part will be omitted anyway. |
| */ |
| private static boolean isHashedInJavaBase(Module m) { |
| // return true if module system is not initialized as the code |
| // must be in java.base |
| if (!VM.isModuleSystemInited()) |
| return true; |
| |
| return Layer.boot() == m.getLayer() && HashedModules.contains(m); |
| } |
| |
| /* |
| * Finds JDK non-upgradeable modules, i.e. the modules that are |
| * included in the hashes in java.base. |
| */ |
| private static class HashedModules { |
| static Set<String> HASHED_MODULES = hashedModules(); |
| |
| static Set<String> hashedModules() { |
| |
| Optional<ResolvedModule> resolvedModule = Layer.boot() |
| .configuration() |
| .findModule("java.base"); |
| assert resolvedModule.isPresent(); |
| ModuleReference mref = resolvedModule.get().reference(); |
| assert mref instanceof ModuleReferenceImpl; |
| ModuleHashes hashes = ((ModuleReferenceImpl)mref).recordedHashes(); |
| if (hashes != null) { |
| Set<String> names = new HashSet<>(hashes.names()); |
| names.add("java.base"); |
| return names; |
| } |
| |
| return Set.of(); |
| } |
| |
| static boolean contains(Module m) { |
| return HASHED_MODULES.contains(m.getName()); |
| } |
| } |
| |
| |
| /* |
| * Returns an array of StackTraceElements of the given depth |
| * filled from the backtrace of a given Throwable. |
| */ |
| static StackTraceElement[] of(Throwable x, int depth) { |
| StackTraceElement[] stackTrace = new StackTraceElement[depth]; |
| for (int i = 0; i < depth; i++) { |
| stackTrace[i] = new StackTraceElement(); |
| } |
| |
| // VM to fill in StackTraceElement |
| initStackTraceElements(stackTrace, x); |
| |
| // ensure the proper StackTraceElement initialization |
| for (StackTraceElement ste : stackTrace) { |
| ste.computeFormat(); |
| } |
| return stackTrace; |
| } |
| |
| /* |
| * Returns a StackTraceElement from a given StackFrameInfo. |
| */ |
| static StackTraceElement of(StackFrameInfo sfi) { |
| StackTraceElement ste = new StackTraceElement(); |
| initStackTraceElement(ste, sfi); |
| |
| ste.computeFormat(); |
| return ste; |
| } |
| |
| /* |
| * Sets the given stack trace elements with the backtrace |
| * of the given Throwable. |
| */ |
| private static native void initStackTraceElements(StackTraceElement[] elements, |
| Throwable x); |
| /* |
| * Sets the given stack trace element with the given StackFrameInfo |
| */ |
| private static native void initStackTraceElement(StackTraceElement element, |
| StackFrameInfo sfi); |
| |
| private static final long serialVersionUID = 6992337162326171013L; |
| } |
