/*
* Copyright (c) 2007, 2011, 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.
*
* 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 com.sun.max.program;
/**
* A collection of static methods for reporting errors indicating some fatal condition.
* In the target VM, these errors can be made to perform a hard exit of the VM by
* redirecting them via a {@linkplain #setHandler(Handler) registered} error handler.
*/
public final class ProgramError extends Error {
/**
* Implemented by a client that can {@linkplain ProgramError#setHandler(Handler) register}
* itself to handle program errors instead of having them result in a {@link ProgramError}
* instance raised.
*/
public interface Handler {
/**
* Handles a given error condition. This method should never return normally.
*
* @param message a message describing the error condition. This value may be {@code null}
* @param throwable an exception given more detail on the cause of the error condition. This value may be {@code null}
*/
void handle(String message, Throwable throwable);
}
/**
* Registers a handler to which error reporting is redirected. Any previously registered handler
* is overwritten and discarded.
*
* @param h if non-null, this object's {@link Handler#handle(String, Throwable)} method is messaged instead of
* raising a ProgramError.
*/
public static void setHandler(Handler h) {
handler = h;
}
private ProgramError(String message, Throwable cause) {
super(message, cause);
}
/**
* Checks a given condition and if it's {@code false}, the appropriate error handling action is taken.
* The message reported to this action is {@code "Program Error"}.
*
* @param condition a condition to test
*/
public static void check(boolean condition) {
if (!condition) {
throw unexpected(null, null);
}
}
/**
* Checks a given condition and if it's {@code false}, the appropriate error handling action is taken.
*
* @param condition a condition to test
* @param message a message describing the error condition being tested
*/
public static void check(boolean condition, String message) {
if (!condition) {
throw unexpected(message, null);
}
}
/**
* Checks a given condition and if it's {@code false}, the appropriate error handling action is taken.
*
* @param condition a condition to test
* @param message a message describing the error condition being tested
* @param object an object whose string description is to be appended to the message
*/
public static void check(boolean condition, String message, Object object) {
if (!condition) {
throw unexpected(message + object.toString(), null);
}
}
/**
* Reports the occurrence of some error condition triggering the appropriate error handling action
* to be taken. By default, this action is to raise a {@link ProgramError} exception. However,
* if an alternative error handler has been {@linkplain #setHandler(Handler) registered}, its
* {@link Handler#handle(String, Throwable)} method is called instead.
*
* This method never returns normally.
*
* @param message a message describing the error condition. This value may be {@code null}.
* @param throwable an exception given more detail on the cause of the error condition. This value may be {@code null}.
*/
public static ProgramError unexpected(String message, Throwable throwable) {
if (handler != null) {
handler.handle(message, throwable);
}
if (message == null) {
throw new ProgramError("Unexpected Program Error:", throwable);
}
throw new ProgramError("Unexpected Program Error: " + message, throwable);
}
/**
* Reports the occurrence of some error condition.
*
* This method never returns normally.
*
* @param message a message describing the error condition. This value may be {@code null}.
* @see #unexpected(String, Throwable)
*/
public static ProgramError unexpected(String message) {
throw unexpected(message, null);
}
/**
* Reports the occurrence of some error condition.
*
* This method never returns normally.
*
* @param throwable an exception given more detail on the cause of the error condition. This value may be {@code null}
* @see #unexpected(String, Throwable)
*/
public static ProgramError unexpected(Throwable throwable) {
throw unexpected(null, throwable);
}
/**
* Reports the occurrence of some error condition.
*
* This method never returns normally.
*
* @param throwable an exception given more detail on the cause of the error condition. This value may be {@code null}
* @see #unexpected(String, Throwable)
*/
public static ProgramError unexpected() {
throw unexpected((String) null);
}
/**
* Reports that a {@code switch} statement encountered a {@code case} value it was not expecting.
*
* This method never returns normally.
*
* @see #unexpected(String, Throwable)
*/
public static ProgramError unknownCase() {
throw unexpected("unknown switch case");
}
/**
* Reports that a {@code switch} statement encountered a {@code case} value it was not expecting.
*
* This method never returns normally.
*
* @param caseValue the unexpected {@code case} value as a string
* @see #unexpected(String, Throwable)
*/
public static ProgramError unknownCase(String caseValue) {
throw unexpected("unknown switch case: " + caseValue);
}
// Checkstyle: stop
private static Handler handler = null;
}