content: /*
   * Copyright (c) 2009, 2013, 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.javap;
  
  import java.util.Arrays;
  import java.util.HashMap;
  import java.util.Map;
  
  import openjdk.tools.classfile.AccessFlags;
  import openjdk.tools.classfile.Attribute;
  import openjdk.tools.classfile.Code_attribute;
  import openjdk.tools.classfile.ConstantPool;
  import openjdk.tools.classfile.ConstantPoolException;
  import openjdk.tools.classfile.Descriptor;
  import openjdk.tools.classfile.Descriptor.InvalidDescriptor;
  import openjdk.tools.classfile.Instruction;
  import openjdk.tools.classfile.Method;
  import openjdk.tools.classfile.StackMapTable_attribute;
  import openjdk.tools.classfile.StackMapTable_attribute.*;
  
  import static openjdk.tools.classfile.StackMapTable_attribute.verification_type_info.*;
  
  /**
   * Annotate instructions with stack map.
   *
   *  <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 StackMapWriter extends InstructionDetailWriter {
      static StackMapWriter instance(Context context) {
          StackMapWriter instance = context.get(StackMapWriter.class);
          if (instance == null)
              instance = new StackMapWriter(context);
          return instance;
      }
  
      protected StackMapWriter(Context context) {
          super(context);
          context.put(StackMapWriter.class, this);
          classWriter = ClassWriter.instance(context);
      }
  
      public void reset(Code_attribute attr) {
          setStackMap((StackMapTable_attribute) attr.attributes.get(Attribute.StackMapTable));
      }
  
      void setStackMap(StackMapTable_attribute attr) {
          if (attr == null) {
              map = null;
              return;
          }
  
          Method m = classWriter.getMethod();
          Descriptor d = m.descriptor;
          String[] args;
          try {
              ConstantPool cp = classWriter.getClassFile().constant_pool;
              String argString = d.getParameterTypes(cp);
              args = argString.substring(1, argString.length() - 1).split("[, ]+");
          } catch (ConstantPoolException | InvalidDescriptor e) {
              return;
          }
          boolean isStatic = m.access_flags.is(AccessFlags.ACC_STATIC);
  
          verification_type_info[] initialLocals = new verification_type_info[(isStatic ? 0 : 1) + args.length];
          if (!isStatic)
              initialLocals[0] = new CustomVerificationTypeInfo("this");
          for (int i = 0; i < args.length; i++) {
              initialLocals[(isStatic ? 0 : 1) + i] =
                      new CustomVerificationTypeInfo(args[i].replace(".", "/"));
          }
  
          map = new HashMap<>();
          StackMapBuilder builder = new StackMapBuilder();
  
          // using -1 as the pc for the initial frame effectively compensates for
          // the difference in behavior for the first stack map frame (where the
          // pc offset is just offset_delta) compared to subsequent frames (where
          // the pc offset is always offset_delta+1).
          int pc = -1;
  
          map.put(pc, new StackMap(initialLocals, empty));
  
          for (int i = 0; i < attr.entries.length; i++)
              pc = attr.entries[i].accept(builder, pc);
      }
  
      public void writeInitialDetails() {
          writeDetails(-1);
      }
  
      public void writeDetails(Instruction instr) {
          writeDetails(instr.getPC());
      }
  
      private void writeDetails(int pc) {
          if (map == null)
              return;
  
          StackMap m = map.get(pc);
          if (m != null) {
              print("StackMap locals: ", m.locals);
              print("StackMap stack: ", m.stack);
          }
  
      }
  
      void print(String label, verification_type_info[] entries) {
          print(label);
          for (int i = 0; i < entries.length; i++) {
              print(" ");
              print(entries[i]);
          }
          println();
      }
  
      void print(verification_type_info entry) {
          if (entry == null) {
              print("ERROR");
              return;
          }
  
          switch (entry.tag) {
              case -1:
                  print(((CustomVerificationTypeInfo) entry).text);
                  break;
  
              case ITEM_Top:
                  print("top");
                  break;
  
              case ITEM_Integer:
                  print("int");
                  break;
  
              case ITEM_Float:
                  print("float");
                  break;
  
              case ITEM_Long:
                  print("long");
                  break;
  
              case ITEM_Double:
                  print("double");
                  break;
  
              case ITEM_Null:
                  print("null");
                  break;
  
              case ITEM_UninitializedThis:
                  print("uninit_this");
                  break;
  
              case ITEM_Object:
                  try {
                      ConstantPool cp = classWriter.getClassFile().constant_pool;
                      ConstantPool.CONSTANT_Class_info class_info = cp.getClassInfo(((Object_variable_info) entry).cpool_index);
                      print(cp.getUTF8Value(class_info.name_index));
                  } catch (ConstantPoolException e) {
                      print("??");
                  }
                  break;
  
              case ITEM_Uninitialized:
                  print(((Uninitialized_variable_info) entry).offset);
                  break;
          }
  
      }
  
      private Map<Integer, StackMap> map;
      private ClassWriter classWriter;
  
      class StackMapBuilder
              implements StackMapTable_attribute.stack_map_frame.Visitor<Integer, Integer> {
  
          public Integer visit_same_frame(same_frame frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap m = map.get(pc);
              assert (m != null);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_same_locals_1_stack_item_frame(same_locals_1_stack_item_frame frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap prev = map.get(pc);
              assert (prev != null);
              StackMap m = new StackMap(prev.locals, frame.stack);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_same_locals_1_stack_item_frame_extended(same_locals_1_stack_item_frame_extended frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap prev = map.get(pc);
              assert (prev != null);
              StackMap m = new StackMap(prev.locals, frame.stack);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_chop_frame(chop_frame frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap prev = map.get(pc);
              assert (prev != null);
              int k = 251 - frame.frame_type;
              verification_type_info[] new_locals = Arrays.copyOf(prev.locals, prev.locals.length - k);
              StackMap m = new StackMap(new_locals, empty);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_same_frame_extended(same_frame_extended frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta();
              StackMap m = map.get(pc);
              assert (m != null);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_append_frame(append_frame frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap prev = map.get(pc);
              assert (prev != null);
              verification_type_info[] new_locals = new verification_type_info[prev.locals.length + frame.locals.length];
              System.arraycopy(prev.locals, 0, new_locals, 0, prev.locals.length);
              System.arraycopy(frame.locals, 0, new_locals, prev.locals.length, frame.locals.length);
              StackMap m = new StackMap(new_locals, empty);
              map.put(new_pc, m);
              return new_pc;
          }
  
          public Integer visit_full_frame(full_frame frame, Integer pc) {
              int new_pc = pc + frame.getOffsetDelta() + 1;
              StackMap m = new StackMap(frame.locals, frame.stack);
              map.put(new_pc, m);
              return new_pc;
          }
  
      }
  
      static class StackMap {
          StackMap(verification_type_info[] locals, verification_type_info[] stack) {
              this.locals = locals;
              this.stack = stack;
          }
  
          private final verification_type_info[] locals;
          private final verification_type_info[] stack;
      }
  
      static class CustomVerificationTypeInfo extends verification_type_info {
          public CustomVerificationTypeInfo(String text) {
              super(-1);
              this.text = text;
          }
          private String text;
      }
  
      private final verification_type_info[] empty = { };
  }
  