svm: further JDK 21 related clean ups

Author: zapster

substratevm/src/com.oracle.svm.core/src/com/oracle/svm/core/SubstrateUtil.java

@@ -30,7 +30,6 @@
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Executable;
 import java.lang.reflect.Field;
-import java.lang.reflect.InvocationTargetException;
 import java.lang.reflect.Member;
 import java.lang.reflect.Method;
 import java.util.List;
@@ -90,26 +89,12 @@ public static String getArchitectureName() {
         };
     }
 
-    /*
-     * [GR-55515]: Accessing isTerminal() reflectively only for 21 JDK compatibility. After dropping
-     * JDK 21, use it directly.
-     */
-    private static final Method IS_TERMINAL_METHOD = ReflectionUtil.lookupMethod(true, Console.class, "isTerminal");
-
     private static boolean isTTY() {
         Console console = System.console();
         if (console == null) {
             return false;
         }
-        if (IS_TERMINAL_METHOD != null) {
-            try {
-                return (boolean) IS_TERMINAL_METHOD.invoke(console);
-            } catch (IllegalAccessException | InvocationTargetException e) {
-                throw new Error(e);
-            }
-        } else {
-            return true;
-        }
+        return console.isTerminal();
     }
 
     public static boolean isNonInteractiveTerminal() {

substratevm/src/com.oracle.svm.hosted/src/com/oracle/svm/hosted/SystemInOutErrFeature.java

@@ -27,11 +27,7 @@
 
 import java.io.InputStream;
 import java.io.PrintStream;
-import java.lang.reflect.Field;
 
-import com.oracle.svm.core.util.VMError;
-import com.oracle.svm.util.ReflectionUtil;
-import jdk.internal.access.SharedSecrets;
 import org.graalvm.nativeimage.ImageSingletons;
 import org.graalvm.nativeimage.hosted.Feature;
 
@@ -44,6 +40,8 @@
 import com.oracle.svm.core.layeredimagesingleton.FeatureSingleton;
 import com.oracle.svm.hosted.imagelayer.CrossLayerConstantRegistry;
 
+import jdk.internal.access.SharedSecrets;
+
 /**
  * We use an {@link Feature.DuringSetupAccess#registerObjectReplacer object replacer} because the
  * streams can be cached in other instance and static fields in addition to the fields in
@@ -64,18 +62,7 @@ public SystemInOutErrFeature() {
         hostedOut = wrappers.outWrapper;
         hostedErr = wrappers.errWrapper;
         hostedInitialIn = SharedSecrets.getJavaLangAccess().initialSystemIn();
-        /*
-         * GR-55515: Migrate to JavaLangAccess#initialSystemErr(). The method
-         * JavaLangAccess#initialSystemErr() and the System#initialErr field were both introduced in
-         * JDK 23. Once JDK 21 compatibility is no longer required, consider switching to
-         * SharedSecrets.getJavaLangAccess().initialSystemErr().
-         */
-        Field initialErrField = ReflectionUtil.lookupField(true, System.class, "initialErr");
-        try {
-            hostedInitialErr = initialErrField != null ? (PrintStream) initialErrField.get(null) : null;
-        } catch (IllegalAccessException illegalAccess) {
-            throw VMError.shouldNotReachHere(illegalAccess);
-        }
+        hostedInitialErr = SharedSecrets.getJavaLangAccess().initialSystemErr();
     }
 
     private SystemInOutErrSupport runtime;