8332029: Provide access to initial value of stderr via JavaLangAccess

Reviewed-by: jpai, bpb, mcimadamore

Author: Alan Bateman

src/java.base/share/classes/java/lang/System.java

@@ -191,8 +191,9 @@ private System() {
      */
     public static final PrintStream err = null;
 
-    // Holder for the initial value of `in`, set within `initPhase1()`.
-    private static InputStream initialIn;
+    // Initial values of System.in and System.err, set in initPhase1().
+    private static @Stable InputStream initialIn;
+    private static @Stable PrintStream initialErr;
 
     // indicates if a security manager is possible
     private static final int NEVER = 1;
@@ -355,9 +356,6 @@ private static class CallersHolder {
             = Collections.synchronizedMap(new WeakHashMap<>());
     }
 
-    // Remember initial System.err. setSecurityManager() warning goes here
-    private static volatile @Stable PrintStream initialErrStream;
-
     private static URL codeSource(Class<?> clazz) {
         PrivilegedAction<ProtectionDomain> pa = clazz::getProtectionDomain;
         @SuppressWarnings("removal")
@@ -417,7 +415,7 @@ public static void setSecurityManager(@SuppressWarnings("removal") SecurityManag
                 } else {
                     source = callerClass.getName() + " (" + url + ")";
                 }
-                initialErrStream.printf("""
+                initialErr.printf("""
                         WARNING: A terminally deprecated method in java.lang.System has been called
                         WARNING: System::setSecurityManager has been called by %s
                         WARNING: Please consider reporting this to the maintainers of %s
@@ -2200,7 +2198,8 @@ private static void initPhase1() {
         // thus they are equivalent to Console.charset(), otherwise the encodings
         // of those properties default to native.encoding
         setOut0(newPrintStream(fdOut, props.getProperty("stdout.encoding")));
-        setErr0(newPrintStream(fdErr, props.getProperty("stderr.encoding")));
+        initialErr = newPrintStream(fdErr, props.getProperty("stderr.encoding"));
+        setErr0(initialErr);
 
         // Setup Java signal handlers for HUP, TERM, and INT (where available).
         Terminator.setup();
@@ -2406,8 +2405,6 @@ private static void initPhase3() {
                     notSupportedJnuEncoding);
         }
 
-        initialErrStream = System.err;
-
         // initializing the system class loader
         VM.initLevel(3);
 
@@ -2598,6 +2595,10 @@ public InputStream initialSystemIn() {
                 return initialIn;
             }
 
+            public PrintStream initialSystemErr() {
+                return initialErr;
+            }
+
             public void setCause(Throwable t, Throwable cause) {
                 t.setCause(cause);
             }

src/java.base/share/classes/jdk/internal/access/JavaLangAccess.java

@@ -26,6 +26,7 @@
 package jdk.internal.access;
 
 import java.io.InputStream;
+import java.io.PrintStream;
 import java.lang.annotation.Annotation;
 import java.lang.foreign.MemorySegment;
 import java.lang.invoke.MethodHandle;
@@ -401,6 +402,11 @@ public interface JavaLangAccess {
      */
     InputStream initialSystemIn();
 
+    /**
+     * Returns the initial value of System.err.
+     */
+    PrintStream initialSystemErr();
+
     /**
      * Encodes ASCII codepoints as possible from the source array into
      * the destination byte array, assuming that the encoding is ASCII

src/java.base/share/classes/jdk/internal/misc/VM.java

@@ -1,5 +1,5 @@
 /*
- * Copyright (c) 1996, 2023, Oracle and/or its affiliates. All rights reserved.
+ * Copyright (c) 1996, 2024, 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
@@ -27,6 +27,7 @@
 
 import static java.lang.Thread.State.*;
 
+import java.io.PrintStream;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.List;
@@ -496,4 +497,11 @@ private static class BufferPoolsHolder {
     public static List<BufferPool> getBufferPools() {
         return BufferPoolsHolder.BUFFER_POOLS;
     }
+
+    /**
+     * Return the initial value of System.err that was set during VM initialization.
+     */
+    public static PrintStream initialErr() {
+        return SharedSecrets.getJavaLangAccess().initialSystemErr();
+    }
 }