8312522: Implementation of Foreign Function & Memory API

src/java.base/share/classes/java/lang/foreign/AddressLayout.java

@@ -50,7 +50,7 @@
  * </ul>
  *
  * @implSpec
- * This class is immutable, thread-safe and <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>.
+ * Implementations of this interface are immutable, thread-safe and <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>.
  *
  * @see #ADDRESS
  * @see #ADDRESS_UNALIGNED

src/java.base/share/classes/java/lang/foreign/MemoryLayout.java

@@ -436,11 +436,11 @@ default MethodHandle byteOffsetHandle(PathElement... elements) {
      *     in which the open path elements occur in the provided layout path.
      * </ul>
      * <p>
-     * If the provided layout path {@code P} contains no dereference elements, then the offset of the access operation is
-     * computed as follows:
+     * If the provided layout path {@code P} contains no dereference elements, then the offset {@code O} of the access
+     * operation is computed as follows:
      *
      * {@snippet lang = "java":
-     * offset = this.offsetHandle(P).invokeExact(B, I1, I2, ... In);
+     * O = this.offsetHandle(P).invokeExact(B, I1, I2, ... In);
      * }
      * <p>
      * Accessing a memory segment using the var handle returned by this method is subject to the following checks:
@@ -533,7 +533,7 @@ default VarHandle varHandle(PathElement... elements) {
      *     elements occur in the provided layout path.
      * </ul>
      * <p>
-     * The offset of the returned segment is computed as if by a call to a
+     * The offset {@code O} of the returned segment is computed as if by a call to a
      * {@linkplain #byteOffsetHandle(PathElement...) byte offset handle} constructed using the given path elements.
      * <p>
      * Computing a slice of a memory segment using the method handle returned by this method is subject to the following checks:

src/java.base/share/classes/java/lang/invoke/MethodHandles.java

@@ -26,8 +26,6 @@
 package java.lang.invoke;
 
 import jdk.internal.access.SharedSecrets;
-import jdk.internal.foreign.Utils;
-import jdk.internal.javac.PreviewFeature;
 import jdk.internal.misc.Unsafe;
 import jdk.internal.misc.VM;
 import jdk.internal.org.objectweb.asm.ClassReader;
@@ -45,10 +43,6 @@
 import sun.security.util.SecurityConstants;
 
 import java.lang.constant.ConstantDescs;
-import java.lang.foreign.GroupLayout;
-import java.lang.foreign.MemoryLayout;
-import java.lang.foreign.MemorySegment;
-import java.lang.foreign.ValueLayout;
 import java.lang.invoke.LambdaForm.BasicType;
 import java.lang.reflect.Constructor;
 import java.lang.reflect.Field;

src/java.base/share/classes/jdk/internal/foreign/StringSupport.java

@@ -42,7 +42,6 @@ public static String read(MemorySegment segment, long offset, Charset charset) {
             case SINGLE_BYTE -> readFast_byte(segment, offset, charset);
             case DOUBLE_BYTE -> readFast_short(segment, offset, charset);
             case QUAD_BYTE -> readFast_int(segment, offset, charset);
-            default -> throw new UnsupportedOperationException("Unsupported charset: " + charset);
         };
     }
 
@@ -51,7 +50,6 @@ public static void write(MemorySegment segment, long offset, Charset charset, St
             case SINGLE_BYTE -> writeFast_byte(segment, offset, charset, string);
             case DOUBLE_BYTE -> writeFast_short(segment, offset, charset, string);
             case QUAD_BYTE -> writeFast_int(segment, offset, charset, string);
-            default -> throw new UnsupportedOperationException("Unsupported charset: " + charset);
         }
     }
     private static String readFast_byte(MemorySegment segment, long offset, Charset charset) {

src/java.base/share/classes/jdk/internal/foreign/layout/AbstractGroupLayout.java

@@ -39,8 +39,6 @@
  *
  * @implSpec
  * This class is immutable, thread-safe and <a href="{@docRoot}/java.base/java/lang/doc-files/ValueBased.html">value-based</a>.
- *
- * @since 19
  */
 public sealed abstract class AbstractGroupLayout<L extends AbstractGroupLayout<L> & MemoryLayout>
         extends AbstractLayout<L>