package mockit.asm.methods;
   
   import edu.umd.cs.findbugs.annotations.NonNull;
   import edu.umd.cs.findbugs.annotations.Nullable;
   
   import mockit.asm.constantPool.AttributeWriter;
   import mockit.asm.constantPool.ConstantPoolGeneration;
   import mockit.asm.controlFlow.Label;
   import mockit.asm.util.ByteVector;
  
  import org.checkerframework.checker.index.qual.NonNegative;
  
  /**
   * Writes the bytecode for the "LocalVariableTable" and "LocalVariableTypeTable" method code attributes.
   */
  final class LocalVariableTableWriter extends AttributeWriter {
      /**
       * Number of entries in the LocalVariableTable attribute.
       */
      @NonNegative
      private int localVarCount;
  
      /**
       * The LocalVariableTable attribute.
       */
      @Nullable
      private ByteVector localVarTable;
  
      @NonNegative
      private int localVarTypeAttributeIndex;
  
      /**
       * Number of entries in the LocalVariableTypeTable attribute.
       */
      @NonNegative
      private int localVarTypeCount;
  
      /**
       * The LocalVariableTypeTable attribute.
       */
      @Nullable
      private ByteVector localVarTypeTable;
  
      LocalVariableTableWriter(@NonNull ConstantPoolGeneration cp) {
          super(cp);
      }
  
      @NonNegative
      int addLocalVariable(@NonNull String name, @NonNull String desc, @Nullable String signature, @NonNull Label start,
              @NonNull Label end, @NonNegative int index) {
          if (signature != null) {
              if (localVarTypeTable == null) {
                  localVarTypeAttributeIndex = cp.newUTF8("LocalVariableTypeTable");
                  localVarTypeTable = new ByteVector();
              }
  
              addAttribute(localVarTypeTable, name, signature, start, end, index);
              localVarTypeCount++;
          }
  
          if (localVarTable == null) {
              setAttribute("LocalVariableTable");
              localVarTable = new ByteVector();
          }
  
          addAttribute(localVarTable, name, desc, start, end, index);
          localVarCount++;
  
          char c = desc.charAt(0);
          return index + (c == 'J' || c == 'D' ? 2 : 1);
      }
  
      private void addAttribute(@NonNull ByteVector attribute, @NonNull String name, @NonNull String desc,
              @NonNull Label start, @NonNull Label end, @NonNegative int index) {
          attribute.putShort(start.position).putShort(end.position - start.position).putShort(cp.newUTF8(name))
                  .putShort(cp.newUTF8(desc)).putShort(index);
      }
  
      @NonNegative
      @Override
      public int getSize() {
          return getSize(localVarTable) + getSize(localVarTypeTable);
      }
  
      @NonNegative
      private static int getSize(@Nullable ByteVector attribute) {
          return attribute == null ? 0 : 8 + attribute.getLength();
      }
  
      @NonNegative
      int getAttributeCount() {
          return (localVarTable == null ? 0 : 1) + (localVarTypeTable == null ? 0 : 1);
      }
  
      @Override
      public void put(@NonNull ByteVector out) {
          put(out, localVarTable, localVarCount);
          attributeIndex = localVarTypeAttributeIndex;
          put(out, localVarTypeTable, localVarTypeCount);
     }
 
     private void put(@NonNull ByteVector out, @Nullable ByteVector attribute, @NonNegative int numEntries) {
         if (attribute != null) {
             put(out, 2 + attribute.getLength());
             out.putShort(numEntries);
             out.putByteVector(attribute);
         }
     }
 }