content: /*
   * Copyright (c) 2007, 2009, 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.  Oracle designates this
   * particular file as subject to the "Classpath" exception as provided
   * by Oracle in the LICENSE file that accompanied this code.
   *
   * 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 openjdk.tools.classfile;
  
  import java.io.IOException;
  
  /**
   * See JVMS, section 4.8.4.
   *
   *  <p><b>This is NOT part of any supported API.
   *  If you write code that depends on this, you do so at your own risk.
   *  This code and its internal interfaces are subject to change or
   *  deletion without notice.</b>
   */
  public class StackMapTable_attribute extends Attribute {
      static class InvalidStackMap extends AttributeException {
          private static final long serialVersionUID = -5659038410855089780L;
          InvalidStackMap(String msg) {
              super(msg);
          }
      }
  
      StackMapTable_attribute(ClassReader cr, int name_index, int length)
              throws IOException, InvalidStackMap {
          super(name_index, length);
          number_of_entries = cr.readUnsignedShort();
          entries = new stack_map_frame[number_of_entries];
          for (int i = 0; i < number_of_entries; i++)
              entries[i] = stack_map_frame.read(cr);
      }
  
      public StackMapTable_attribute(ConstantPool constant_pool, stack_map_frame[] entries)
              throws ConstantPoolException {
          this(constant_pool.getUTF8Index(Attribute.StackMapTable), entries);
      }
  
      public StackMapTable_attribute(int name_index, stack_map_frame[] entries) {
          super(name_index, length(entries));
          this.number_of_entries = entries.length;
          this.entries = entries;
      }
  
      public <R, D> R accept(Visitor<R, D> visitor, D data) {
          return visitor.visitStackMapTable(this, data);
      }
  
      static int length(stack_map_frame[] entries) {
          int n = 2;
          for (stack_map_frame entry: entries)
              n += entry.length();
          return n;
      }
  
      public final int number_of_entries;
      public final stack_map_frame entries[];
  
      public static abstract class stack_map_frame {
          static stack_map_frame read(ClassReader cr)
                  throws IOException, InvalidStackMap {
              int frame_type = cr.readUnsignedByte();
              if (frame_type <= 63)
                  return new same_frame(frame_type);
              else if (frame_type <= 127)
                  return new same_locals_1_stack_item_frame(frame_type, cr);
              else if (frame_type <= 246)
                  throw new Error("unknown frame_type " + frame_type);
              else if (frame_type == 247)
                  return new same_locals_1_stack_item_frame_extended(frame_type, cr);
              else if (frame_type <= 250)
                  return new chop_frame(frame_type, cr);
              else if (frame_type == 251)
                  return new same_frame_extended(frame_type, cr);
              else if (frame_type <= 254)
                  return new append_frame(frame_type, cr);
              else
                  return new full_frame(frame_type, cr);
          }
  
          protected stack_map_frame(int frame_type) {
              this.frame_type = frame_type;
          }
  
          public int length() {
              return 1;
          }
  
          public abstract int getOffsetDelta();
  
          public abstract <R,D> R accept(Visitor<R,D> visitor, D data);
  
          public final int frame_type;
  
          public static interface Visitor<R,P> {
              R visit_same_frame(same_frame frame, P p);
              R visit_same_locals_1_stack_item_frame(same_locals_1_stack_item_frame frame, P p);
              R visit_same_locals_1_stack_item_frame_extended(same_locals_1_stack_item_frame_extended frame, P p);
              R visit_chop_frame(chop_frame frame, P p);
              R visit_same_frame_extended(same_frame_extended frame, P p);
              R visit_append_frame(append_frame frame, P p);
              R visit_full_frame(full_frame frame, P p);
          }
      }
  
      public static class same_frame extends stack_map_frame {
          same_frame(int frame_type) {
              super(frame_type);
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_same_frame(this, data);
          }
  
          public int getOffsetDelta() {
              return frame_type;
          }
      }
  
      public static class same_locals_1_stack_item_frame extends stack_map_frame {
          same_locals_1_stack_item_frame(int frame_type, ClassReader cr)
                  throws IOException, InvalidStackMap {
              super(frame_type);
              stack = new verification_type_info[1];
              stack[0] = verification_type_info.read(cr);
          }
  
          @Override
          public int length() {
              return super.length() + stack[0].length();
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_same_locals_1_stack_item_frame(this, data);
          }
  
          public int getOffsetDelta() {
              return frame_type - 64;
          }
  
          public final verification_type_info[] stack;
      }
  
      public static class same_locals_1_stack_item_frame_extended extends stack_map_frame {
          same_locals_1_stack_item_frame_extended(int frame_type, ClassReader cr)
                  throws IOException, InvalidStackMap {
              super(frame_type);
              offset_delta = cr.readUnsignedShort();
              stack = new verification_type_info[1];
              stack[0] = verification_type_info.read(cr);
          }
  
          @Override
          public int length() {
              return super.length() + 2 + stack[0].length();
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_same_locals_1_stack_item_frame_extended(this, data);
          }
  
          public int getOffsetDelta() {
              return offset_delta;
          }
  
          public final int offset_delta;
          public final verification_type_info[] stack;
      }
  
      public static class chop_frame extends stack_map_frame {
          chop_frame(int frame_type, ClassReader cr) throws IOException {
              super(frame_type);
              offset_delta = cr.readUnsignedShort();
          }
  
          @Override
          public int length() {
              return super.length() + 2;
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_chop_frame(this, data);
          }
  
          public int getOffsetDelta() {
              return offset_delta;
          }
  
          public final int offset_delta;
      }
  
      public static class same_frame_extended extends stack_map_frame {
          same_frame_extended(int frame_type, ClassReader cr) throws IOException {
              super(frame_type);
              offset_delta = cr.readUnsignedShort();
          }
  
          @Override
          public int length() {
              return super.length() + 2;
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_same_frame_extended(this, data);
          }
  
          public int getOffsetDelta() {
              return offset_delta;
          }
  
          public final int offset_delta;
      }
  
      public static class append_frame extends stack_map_frame {
          append_frame(int frame_type, ClassReader cr)
                  throws IOException, InvalidStackMap {
              super(frame_type);
              offset_delta = cr.readUnsignedShort();
              locals = new verification_type_info[frame_type - 251];
              for (int i = 0; i < locals.length; i++)
                  locals[i] = verification_type_info.read(cr);
          }
  
          @Override
          public int length() {
              int n = super.length() + 2;
              for (verification_type_info local: locals)
                  n += local.length();
              return n;
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_append_frame(this, data);
          }
  
          public int getOffsetDelta() {
              return offset_delta;
          }
  
          public final int offset_delta;
          public final verification_type_info[] locals;
      }
  
      public static class full_frame extends stack_map_frame {
          full_frame(int frame_type, ClassReader cr)
                  throws IOException, InvalidStackMap {
              super(frame_type);
              offset_delta = cr.readUnsignedShort();
              number_of_locals = cr.readUnsignedShort();
              locals = new verification_type_info[number_of_locals];
              for (int i = 0; i < locals.length; i++)
                  locals[i] = verification_type_info.read(cr);
              number_of_stack_items = cr.readUnsignedShort();
              stack = new verification_type_info[number_of_stack_items];
              for (int i = 0; i < stack.length; i++)
                  stack[i] = verification_type_info.read(cr);
          }
  
          @Override
          public int length() {
              int n = super.length() + 2;
              for (verification_type_info local: locals)
                  n += local.length();
              n += 2;
              for (verification_type_info item: stack)
                  n += item.length();
              return n;
          }
  
          public <R, D> R accept(Visitor<R, D> visitor, D data) {
              return visitor.visit_full_frame(this, data);
          }
  
          public int getOffsetDelta() {
              return offset_delta;
          }
  
          public final int offset_delta;
          public final int number_of_locals;
          public final verification_type_info[] locals;
          public final int number_of_stack_items;
          public final verification_type_info[] stack;
      }
  
      public static class verification_type_info {
          public static final int ITEM_Top = 0;
          public static final int ITEM_Integer = 1;
          public static final int ITEM_Float = 2;
          public static final int ITEM_Long = 4;
          public static final int ITEM_Double = 3;
          public static final int ITEM_Null = 5;
          public static final int ITEM_UninitializedThis = 6;
          public static final int ITEM_Object = 7;
          public static final int ITEM_Uninitialized = 8;
  
          static verification_type_info read(ClassReader cr)
                  throws IOException, InvalidStackMap {
              int tag = cr.readUnsignedByte();
              switch (tag) {
              case ITEM_Top:
              case ITEM_Integer:
              case ITEM_Float:
              case ITEM_Long:
              case ITEM_Double:
              case ITEM_Null:
              case ITEM_UninitializedThis:
                  return new verification_type_info(tag);
  
              case ITEM_Object:
                  return new Object_variable_info(cr);
  
              case ITEM_Uninitialized:
                  return new Uninitialized_variable_info(cr);
  
              default:
                  throw new InvalidStackMap("unrecognized verification_type_info tag");
              }
          }
  
          protected verification_type_info(int tag) {
              this.tag = tag;
          }
  
          public int length() {
              return 1;
          }
  
          public final int tag;
      }
  
      public static class Object_variable_info extends verification_type_info {
          Object_variable_info(ClassReader cr) throws IOException {
              super(ITEM_Object);
              cpool_index = cr.readUnsignedShort();
          }
  
          @Override
          public int length() {
              return super.length() + 2;
          }
  
          public final int cpool_index;
      }
  
      public static class Uninitialized_variable_info extends verification_type_info {
          Uninitialized_variable_info(ClassReader cr) throws IOException {
              super(ITEM_Uninitialized);
              offset = cr.readUnsignedShort();
          }
  
          @Override
          public int length() {
              return super.length() + 2;
          }
  
          public final int offset;
  
      }
  }
  