Yatopia/patches/server/0068-Fix-Log4j-Warning.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: snoopdoooggyttv <snoopdoooggyttv@users.noreply.github.com>
Date: Wed, 5 May 2021 20:32:22 +0200
Subject: [PATCH] Fix Log4j Warning


diff --git a/src/main/java/org/apache/logging/log4j/util/StackLocator.java b/src/main/java/org/apache/logging/log4j/util/StackLocator.java
new file mode 100644
index 0000000000000000000000000000000000000000..44161840e64946b4b6ce0483495304809d15ade8
--- /dev/null
+++ b/src/main/java/org/apache/logging/log4j/util/StackLocator.java
@@ -0,0 +1,250 @@
+/*
+ * Licensed to the Apache Software Foundation (ASF) under one or more
+ * contributor license agreements. See the NOTICE file distributed with
+ * this work for additional information regarding copyright ownership.
+ * The ASF licenses this file to You under the Apache license, Version 2.0
+ * (the "License"); you may not use this file except in compliance with
+ * the License. You may obtain a copy of the License at
+ *
+ *      http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the license for the specific language governing permissions and
+ * limitations under the license.
+ */
+package org.apache.logging.log4j.util;
+
+import java.lang.reflect.Method;
+import java.util.Stack;
+
+/**
+ * <em>Consider this class private.</em> Provides various methods to determine the caller class. <h3>Background</h3>
+ * <p>
+ * This method, available only in the Oracle/Sun/OpenJDK implementations of the Java Virtual Machine, is a much more
+ * efficient mechanism for determining the {@link Class} of the caller of a particular method. When it is not available,
+ * a {@link SecurityManager} is the second-best option. When this is also not possible, the {@code StackTraceElement[]}
+ * returned by {@link Throwable#getStackTrace()} must be used, and its {@code String} class name converted to a
+ * {@code Class} using the slow {@link Class#forName} (which can add an extra microsecond or more for each invocation
+ * depending on the runtime ClassLoader hierarchy).
+ * </p>
+ * <p>
+ * During Java 8 development, the {@code sun.reflect.Reflection.getCallerClass(int)} was removed from OpenJDK, and this
+ * change was back-ported to Java 7 in version 1.7.0_25 which changed the behavior of the call and caused it to be off
+ * by one stack frame. This turned out to be beneficial for the survival of this API as the change broke hundreds of
+ * libraries and frameworks relying on the API which brought much more attention to the intended API removal.
+ * </p>
+ * <p>
+ * After much community backlash, the JDK team agreed to restore {@code getCallerClass(int)} and keep its existing
+ * behavior for the rest of Java 7. However, the method is deprecated in Java 8, and current Java 9 development has not
+ * addressed this API. Therefore, the functionality of this class cannot be relied upon for all future versions of Java.
+ * It does, however, work just fine in Sun JDK 1.6, OpenJDK 1.6, Oracle/OpenJDK 1.7, and Oracle/OpenJDK 1.8. Other Java
+ * environments may fall back to using {@link Throwable#getStackTrace()} which is significantly slower due to
+ * examination of every virtual frame of execution.
+ * </p>
+ */
+public final class StackLocator {
+
+    // Checkstyle Suppress: the lower-case 'u' ticks off CheckStyle...
+    // CHECKSTYLE:OFF
+    static final int JDK_7u25_OFFSET;
+    // CHECKSTYLE:OFF
+
+    private static final Method GET_CALLER_CLASS;
+
+    private static final StackLocator INSTANCE;
+
+    static {
+        Method getCallerClass;
+        int java7u25CompensationOffset = 0;
+        try {
+            final Class<?> sunReflectionClass = LoaderUtil.loadClass("sun.reflect.Reflection");
+            getCallerClass = sunReflectionClass.getDeclaredMethod("getCallerClass", int.class);
+            Object o = getCallerClass.invoke(null, 0);
+            getCallerClass.invoke(null, 0);
+            if (o == null || o != sunReflectionClass) {
+                getCallerClass = null;
+                java7u25CompensationOffset = -1;
+            } else {
+                o = getCallerClass.invoke(null, 1);
+                if (o == sunReflectionClass) {
+                    System.out.println("WARNING: Java 1.7.0_25 is in use which has a broken implementation of Reflection.getCallerClass(). " +
+                        " Please consider upgrading to Java 1.7.0_40 or later.");
+                    java7u25CompensationOffset = 1;
+                }
+            }
+        } catch (final Exception | LinkageError e) {
+            //System.out.println("WARNING: sun.reflect.Reflection.getCallerClass is not supported. This will impact performance."); // Yatopia - Fix Error Message
+            getCallerClass = null;
+            java7u25CompensationOffset = -1;
+        }
+
+        GET_CALLER_CLASS = getCallerClass;
+        JDK_7u25_OFFSET = java7u25CompensationOffset;
+
+        INSTANCE = new StackLocator();
+    }
+
+    public static StackLocator getInstance() {
+        return INSTANCE;
+    }
+
+    private StackLocator() {
+    }
+
+    // TODO: return Object.class instead of null (though it will have a null ClassLoader)
+    // (MS) I believe this would work without any modifications elsewhere, but I could be wrong
+
+    // migrated from ReflectiveCallerClassUtility
+    @PerformanceSensitive
+    public Class<?> getCallerClass(final int depth) {
+        if (depth < 0) {
+            throw new IndexOutOfBoundsException(Integer.toString(depth));
+        }
+        if (GET_CALLER_CLASS == null) {
+            return null;
+        }
+        // note that we need to add 1 to the depth value to compensate for this method, but not for the Method.invoke
+        // since Reflection.getCallerClass ignores the call to Method.invoke()
+        try {
+            return (Class<?>) GET_CALLER_CLASS.invoke(null, depth + 1 + JDK_7u25_OFFSET);
+        } catch (final Exception e) {
+            // theoretically this could happen if the caller class were native code
+            // TODO: return Object.class
+            return null;
+        }
+    }
+
+    // migrated from Log4jLoggerFactory
+    @PerformanceSensitive
+    public Class<?> getCallerClass(final String fqcn, final String pkg) {
+        return getCallerClass(fqcn, pkg, 0);
+    }
+
+    @PerformanceSensitive
+    public Class<?> getCallerClass(final String fqcn, final String pkg, final int skipDepth) {
+        if (skipDepth < 0) {
+            throw new IllegalArgumentException("skipDepth cannot be negative");
+        }
+        boolean next = false;
+        Class<?> clazz;
+        for (int i = 2; null != (clazz = getCallerClass(i)); i++) {
+            if (fqcn.equals(clazz.getName())) {
+                next = true;
+                continue;
+            }
+            if (next && clazz.getName().startsWith(pkg)) {
+                return skipDepth == 0
+                        ? clazz
+                        : getCallerClass(i + skipDepth);
+            }
+        }
+        // TODO: return Object.class
+        return null;
+    }
+
+    // added for use in LoggerAdapter implementations mainly
+    @PerformanceSensitive
+    public Class<?> getCallerClass(final Class<?> anchor) {
+        boolean next = false;
+        Class<?> clazz;
+        for (int i = 2; null != (clazz = getCallerClass(i)); i++) {
+            if (anchor.equals(clazz)) {
+                next = true;
+                continue;
+            }
+            if (next) {
+                return clazz;
+            }
+        }
+        return Object.class;
+    }
+
+    // migrated from ThrowableProxy
+    @PerformanceSensitive
+    public Stack<Class<?>> getCurrentStackTrace() {
+        // benchmarks show that using the SecurityManager is much faster than looping through getCallerClass(int)
+        if (PrivateSecurityManagerStackTraceUtil.isEnabled()) {
+            return PrivateSecurityManagerStackTraceUtil.getCurrentStackTrace();
+        }
+        // slower version using getCallerClass where we cannot use a SecurityManager
+        final Stack<Class<?>> classes = new Stack<>();
+        Class<?> clazz;
+        for (int i = 1; null != (clazz = getCallerClass(i)); i++) {
+            classes.push(clazz);
+        }
+        return classes;
+    }
+
+    public StackTraceElement calcLocation(final String fqcnOfLogger) {
+        if (fqcnOfLogger == null) {
+            return null;
+        }
+        // LOG4J2-1029 new Throwable().getStackTrace is faster than Thread.currentThread().getStackTrace().
+        final StackTraceElement[] stackTrace = new Throwable().getStackTrace();
+        boolean found = false;
+        for (int i = 0; i < stackTrace.length; i++) {
+            final String className = stackTrace[i].getClassName();
+            if (fqcnOfLogger.equals(className)) {
+
+                found = true;
+                continue;
+            }
+            if (found && !fqcnOfLogger.equals(className)) {
+                return stackTrace[i];
+            }
+        }
+        return null;
+    }
+
+    public StackTraceElement getStackTraceElement(final int depth) {
+        // (MS) I tested the difference between using Throwable.getStackTrace() and Thread.getStackTrace(), and
+        // the version using Throwable was surprisingly faster! at least on Java 1.8. See ReflectionBenchmark.
+        final StackTraceElement[] elements = new Throwable().getStackTrace();
+        int i = 0;
+        for (final StackTraceElement element : elements) {
+            if (isValid(element)) {
+                if (i == depth) {
+                    return element;
+                }
+                ++i;
+            }
+        }
+        throw new IndexOutOfBoundsException(Integer.toString(depth));
+    }
+
+    private boolean isValid(final StackTraceElement element) {
+        // ignore native methods (oftentimes are repeated frames)
+        if (element.isNativeMethod()) {
+            return false;
+        }
+        final String cn = element.getClassName();
+        // ignore OpenJDK internal classes involved with reflective invocation
+        if (cn.startsWith("sun.reflect.")) {
+            return false;
+        }
+        final String mn = element.getMethodName();
+        // ignore use of reflection including:
+        // Method.invoke
+        // InvocationHandler.invoke
+        // Constructor.newInstance
+        if (cn.startsWith("java.lang.reflect.") && (mn.equals("invoke") || mn.equals("newInstance"))) {
+            return false;
+        }
+        // ignore use of Java 1.9+ reflection classes
+        if (cn.startsWith("jdk.internal.reflect.")) {
+            return false;
+        }
+        // ignore Class.newInstance
+        if (cn.equals("java.lang.Class") && mn.equals("newInstance")) {
+            return false;
+        }
+        // ignore use of Java 1.7+ MethodHandle.invokeFoo() methods
+        if (cn.equals("java.lang.invoke.MethodHandle") && mn.startsWith("invoke")) {
+            return false;
+        }
+        // any others?
+        return true;
+    }
+}