org.objectweb.asm.Type#FLOAT源码实例Demo

private void emitPrimitiveCompare(CodeEmitter code, TypeWidget type) {
    switch (type.getJVMType().getSort()) {
        case Type.BYTE:
        case Type.BOOLEAN:
        case Type.SHORT:
        case Type.INT:
        case Type.CHAR:
            code.getMethodVisitor().visitMethodInsn(Opcodes.INVOKESTATIC, Type.getInternalName(Integer.class), "compare", Type.getMethodDescriptor(Type.INT_TYPE, Type.INT_TYPE, Type.INT_TYPE), false);
            break;
        case Type.FLOAT:
            code.getMethodVisitor().visitInsn(Opcodes.FCMPG);
            break;
        case Type.LONG:
            code.getMethodVisitor().visitInsn(Opcodes.LCMP);
            break;
        case Type.DOUBLE:
            code.getMethodVisitor().visitInsn(Opcodes.DCMPG);
            break;
        default:
            throw new UnsupportedOperationException("Unexpected primitive type: " + leftExpr.getType().getJVMType().getDescriptor());
    }
}
 

public static Type getBoxedType(Type type) {
    switch (type.getSort()) {
    case Type.CHAR:
        return Constants.TYPE_CHARACTER;
    case Type.BOOLEAN:
        return Constants.TYPE_BOOLEAN;
    case Type.DOUBLE:
        return Constants.TYPE_DOUBLE;
    case Type.FLOAT:
        return Constants.TYPE_FLOAT;
    case Type.LONG:
        return Constants.TYPE_LONG;
    case Type.INT:
        return Constants.TYPE_INTEGER;
    case Type.SHORT:
        return Constants.TYPE_SHORT;
    case Type.BYTE:
        return Constants.TYPE_BYTE;
    default:
        return type;
    }
}
 

private void pushDefault(Type type) {
    switch (type.getSort()) {
        case Type.VOID:
            break;
        case Type.DOUBLE:
            mv.visitInsn(DCONST_0);
            break;
        case Type.LONG:
            mv.visitInsn(LCONST_0);
            break;
        case Type.FLOAT:
            mv.visitInsn(FCONST_0);
            break;
        case Type.OBJECT:
        case Type.ARRAY:
            mv.visitInsn(ACONST_NULL);
            break;
        default:
            mv.visitInsn(ICONST_0);
            break;
    }
}
 

public static AbstractInsnNode nullValueForType(Type returnType) {
    switch (returnType.getSort()) {
        case Type.BOOLEAN:
        case Type.BYTE:
        case Type.CHAR:
        case Type.SHORT:
        case Type.INT:
            return new InsnNode(ICONST_0);
        case Type.FLOAT:
            return new InsnNode(FCONST_0);
        case Type.DOUBLE:
            return new InsnNode(DCONST_0);
        case Type.LONG:
            return new InsnNode(LCONST_0);
        case Type.ARRAY:
        case Type.OBJECT:
            return new InsnNode(ACONST_NULL);
        default:
            throw new UnsupportedOperationException();
    }
}
 

public Variable getReturnCacheVar(Type type) {
    Validate.notNull(type);

    switch (type.getSort()) {
        case Type.BOOLEAN:
        case Type.BYTE:
        case Type.CHAR:
        case Type.SHORT:
        case Type.INT:
            return getIntReturnCacheVar();
        case Type.LONG:
            return getLongReturnCacheVar();
        case Type.FLOAT:
            return getFloatReturnCacheVar();
        case Type.DOUBLE:
            return getDoubleReturnCacheVar();
        case Type.ARRAY:
        case Type.OBJECT:
            return getObjectReturnCacheVar();
        case Type.VOID:
            return null;
        default:
            throw new IllegalArgumentException("Bad type");
    }
}
 

Type getBoxedType(final Type type) {
    switch (type.getSort()) {
        case Type.BYTE:
            return BYTE_TYPE;
        case Type.BOOLEAN:
            return BOOLEAN_TYPE;
        case Type.SHORT:
            return SHORT_TYPE;
        case Type.CHAR:
            return CHARACTER_TYPE;
        case Type.INT:
            return INTEGER_TYPE;
        case Type.FLOAT:
            return FLOAT_TYPE;
        case Type.LONG:
            return LONG_TYPE;
        case Type.DOUBLE:
            return DOUBLE_TYPE;
    }
    return type;
}
 

@Override
public BasicValue newValue(final Type type) {
  if (type == null) {
    return BasicValue.UNINITIALIZED_VALUE;
  }
  switch (type.getSort()) {
    case Type.VOID:
      return null;
    case Type.BOOLEAN:
    case Type.CHAR:
    case Type.BYTE:
    case Type.SHORT:
    case Type.INT:
      return BasicValue.INT_VALUE;
    case Type.FLOAT:
      return BasicValue.FLOAT_VALUE;
    case Type.LONG:
      return BasicValue.LONG_VALUE;
    case Type.DOUBLE:
      return BasicValue.DOUBLE_VALUE;
    case Type.ARRAY:
    case Type.OBJECT:
      return BasicValue.REFERENCE_VALUE;
    default:
      throw new AssertionError();
  }
}
 

@Override
public BasicValue newValue(final Type type) {
	if (type == null) {
		return BasicValue.UNINITIALIZED_VALUE;
	}
	switch (type.getSort()) {
	case Type.VOID:
		return null;
	case Type.BOOLEAN:
	case Type.CHAR:
	case Type.BYTE:
	case Type.SHORT:
	case Type.INT:
		return BasicValue.INT_VALUE;
	case Type.FLOAT:
		return BasicValue.FLOAT_VALUE;
	case Type.LONG:
		return BasicValue.LONG_VALUE;
	case Type.DOUBLE:
		return BasicValue.DOUBLE_VALUE;
	case Type.ARRAY:
	case Type.OBJECT:
		return BasicValue.REFERENCE_VALUE;
	default:
		throw new AssertionError();
	}
}
 

/**
 * Generates the instructions to unbox the top stack value. This value is replaced by its unboxed
 * equivalent on top of the stack.
 *
 * @param type the type of the top stack value.
 */
public void unbox(final Type type) {
  Type boxedType = NUMBER_TYPE;
  Method unboxMethod;
  switch (type.getSort()) {
    case Type.VOID:
      return;
    case Type.CHAR:
      boxedType = CHARACTER_TYPE;
      unboxMethod = CHAR_VALUE;
      break;
    case Type.BOOLEAN:
      boxedType = BOOLEAN_TYPE;
      unboxMethod = BOOLEAN_VALUE;
      break;
    case Type.DOUBLE:
      unboxMethod = DOUBLE_VALUE;
      break;
    case Type.FLOAT:
      unboxMethod = FLOAT_VALUE;
      break;
    case Type.LONG:
      unboxMethod = LONG_VALUE;
      break;
    case Type.INT:
    case Type.SHORT:
    case Type.BYTE:
      unboxMethod = INT_VALUE;
      break;
    default:
      unboxMethod = null;
      break;
  }
  if (unboxMethod == null) {
    checkCast(type);
  } else {
    checkCast(boxedType);
    invokeVirtual(boxedType, unboxMethod);
  }
}
 

/**
 * Generates the instructions to unbox the top stack value. This value is replaced by its unboxed
 * equivalent on top of the stack.
 *
 * @param type the type of the top stack value.
 */
public void unbox(final Type type) {
  Type boxedType = NUMBER_TYPE;
  Method unboxMethod;
  switch (type.getSort()) {
    case Type.VOID:
      return;
    case Type.CHAR:
      boxedType = CHARACTER_TYPE;
      unboxMethod = CHAR_VALUE;
      break;
    case Type.BOOLEAN:
      boxedType = BOOLEAN_TYPE;
      unboxMethod = BOOLEAN_VALUE;
      break;
    case Type.DOUBLE:
      unboxMethod = DOUBLE_VALUE;
      break;
    case Type.FLOAT:
      unboxMethod = FLOAT_VALUE;
      break;
    case Type.LONG:
      unboxMethod = LONG_VALUE;
      break;
    case Type.INT:
    case Type.SHORT:
    case Type.BYTE:
      unboxMethod = INT_VALUE;
      break;
    default:
      unboxMethod = null;
  }
  if (unboxMethod == null) {
    checkCast(type);
  } else {
    checkCast(boxedType);
    invokeVirtual(boxedType, unboxMethod);
  }
}
 

/**
 * Generates the instruction to create a new array.
 *
 * @param type the type of the array elements.
 */
public void newArray(final Type type) {
  int arrayType;
  switch (type.getSort()) {
    case Type.BOOLEAN:
      arrayType = Opcodes.T_BOOLEAN;
      break;
    case Type.CHAR:
      arrayType = Opcodes.T_CHAR;
      break;
    case Type.BYTE:
      arrayType = Opcodes.T_BYTE;
      break;
    case Type.SHORT:
      arrayType = Opcodes.T_SHORT;
      break;
    case Type.INT:
      arrayType = Opcodes.T_INT;
      break;
    case Type.FLOAT:
      arrayType = Opcodes.T_FLOAT;
      break;
    case Type.LONG:
      arrayType = Opcodes.T_LONG;
      break;
    case Type.DOUBLE:
      arrayType = Opcodes.T_DOUBLE;
      break;
    default:
      typeInsn(Opcodes.ANEWARRAY, type);
      return;
  }
  mv.visitIntInsn(Opcodes.NEWARRAY, arrayType);
}
 

public static boolean isPrimitiveType(Type type) {
    switch (type.getSort()) {
        case Type.BYTE:
        case Type.BOOLEAN:
        case Type.CHAR:
        case Type.SHORT:
        case Type.INT:
        case Type.FLOAT:
        case Type.LONG:
        case Type.DOUBLE:
            return true;
        default:
            return false;
    }
}
 

/**
 * Generates the instruction to push the given value on the stack.
 *
 * @param value the value to be pushed on the stack.
 */
public void push(final Type value) {
  if (value == null) {
    mv.visitInsn(Opcodes.ACONST_NULL);
  } else {
    switch (value.getSort()) {
      case Type.BOOLEAN:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Boolean", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.CHAR:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Character", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.BYTE:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Byte", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.SHORT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Short", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.INT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Integer", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.FLOAT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Float", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.LONG:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Long", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.DOUBLE:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Double", "TYPE", CLASS_DESCRIPTOR);
        break;
      default:
        mv.visitLdcInsn(value);
        break;
    }
  }
}
 

/**
 * Generates the instructions to unbox the top stack value. This value is replaced by its unboxed
 * equivalent on top of the stack.
 *
 * @param type the type of the top stack value.
 */
public void unbox(final Type type) {
  Type boxedType = NUMBER_TYPE;
  Method unboxMethod;
  switch (type.getSort()) {
    case Type.VOID:
      return;
    case Type.CHAR:
      boxedType = CHARACTER_TYPE;
      unboxMethod = CHAR_VALUE;
      break;
    case Type.BOOLEAN:
      boxedType = BOOLEAN_TYPE;
      unboxMethod = BOOLEAN_VALUE;
      break;
    case Type.DOUBLE:
      unboxMethod = DOUBLE_VALUE;
      break;
    case Type.FLOAT:
      unboxMethod = FLOAT_VALUE;
      break;
    case Type.LONG:
      unboxMethod = LONG_VALUE;
      break;
    case Type.INT:
    case Type.SHORT:
    case Type.BYTE:
      unboxMethod = INT_VALUE;
      break;
    default:
      unboxMethod = null;
      break;
  }
  if (unboxMethod == null) {
    checkCast(type);
  } else {
    checkCast(boxedType);
    invokeVirtual(boxedType, unboxMethod);
  }
}
 

/**
 * Creates an array of {@link Class} objects with the same size of the array of the passed
 * parameter types. For each parameter type, stores its {@link Class} object into the
 * result array. For intrinsic types which are not present in the class constant pool, just
 * push the actual {@link Type} object on the stack and let ASM do the rest. For non
 * intrinsic type use a {@link MethodVisitor#visitLdcInsn(Object)} to ensure the
 * referenced class's presence in this class constant pool.
 * <p>
 * Stack Before : nothing of interest
 * Stack After : <array of {@link Class}>
 *
 * @param parameterTypes a method list of parameters.
 */
private void pushParameterTypesOnStack(Type[] parameterTypes) {
    push(parameterTypes.length);
    newArray(Type.getType(Class.class));

    for (int i = 0; i < parameterTypes.length; i++) {
        dup();
        push(i);
        switch (parameterTypes[i].getSort()) {
            case Type.OBJECT:
            case Type.ARRAY:
                visitLdcInsn(parameterTypes[i]);
                break;
            case Type.BOOLEAN:
            case Type.CHAR:
            case Type.BYTE:
            case Type.SHORT:
            case Type.INT:
            case Type.LONG:
            case Type.FLOAT:
            case Type.DOUBLE:
                push(parameterTypes[i]);
                break;
            default:
                throw new RuntimeException(
                        "Unexpected parameter type " + parameterTypes[i]);

        }
        arrayStore(Type.getType(Class.class));
    }
}
 

@Override
public BasicValue newValue(final Type type) {
  if (type == null) {
    return BasicValue.UNINITIALIZED_VALUE;
  }
  switch (type.getSort()) {
    case Type.VOID:
      return null;
    case Type.BOOLEAN:
    case Type.CHAR:
    case Type.BYTE:
    case Type.SHORT:
    case Type.INT:
      return BasicValue.INT_VALUE;
    case Type.FLOAT:
      return BasicValue.FLOAT_VALUE;
    case Type.LONG:
      return BasicValue.LONG_VALUE;
    case Type.DOUBLE:
      return BasicValue.DOUBLE_VALUE;
    case Type.ARRAY:
    case Type.OBJECT:
      return BasicValue.REFERENCE_VALUE;
    default:
      throw new AssertionError();
  }
}
 

/**
 * Generates the instruction to push the given value on the stack.
 *
 * @param value the value to be pushed on the stack.
 */
public void push(final Type value) {
  if (value == null) {
    mv.visitInsn(Opcodes.ACONST_NULL);
  } else {
    switch (value.getSort()) {
      case Type.BOOLEAN:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Boolean", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.CHAR:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Character", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.BYTE:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Byte", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.SHORT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Short", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.INT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Integer", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.FLOAT:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Float", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.LONG:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Long", "TYPE", CLASS_DESCRIPTOR);
        break;
      case Type.DOUBLE:
        mv.visitFieldInsn(Opcodes.GETSTATIC, "java/lang/Double", "TYPE", CLASS_DESCRIPTOR);
        break;
      default:
        mv.visitLdcInsn(value);
    }
  }
}
 

/**
 * Generates instructions that returns a dummy value. Return values are as follows:
 * <ul>
 * <li>void -&gt; no value</li>
 * <li>boolean -&gt; false</li>
 * <li>byte/short/char/int -&gt; 0</li>
 * <li>long -&gt; 0L</li>
 * <li>float -&gt; 0.0f</li>
 * <li>double -&gt; 0.0</li>
 * <li>Object -&gt; null</li>
 * </ul>
 *
 * @param returnType return type of the method this generated bytecode is for
 * @return instructions to return a dummy value
 * @throws NullPointerException if any argument is {@code null}
 * @throws IllegalArgumentException if {@code returnType}'s sort is of {@link Type#METHOD}
 */
private static InsnList returnDummy(Type returnType) {
    Validate.notNull(returnType);
    Validate.isTrue(returnType.getSort() != Type.METHOD);

    InsnList ret = new InsnList();

    switch (returnType.getSort()) {
        case Type.VOID:
            ret.add(new InsnNode(Opcodes.RETURN));
            break;
        case Type.BOOLEAN:
        case Type.BYTE:
        case Type.SHORT:
        case Type.CHAR:
        case Type.INT:
            ret.add(new InsnNode(Opcodes.ICONST_0));
            ret.add(new InsnNode(Opcodes.IRETURN));
            break;
        case Type.LONG:
            ret.add(new InsnNode(Opcodes.LCONST_0));
            ret.add(new InsnNode(Opcodes.LRETURN));
            break;
        case Type.FLOAT:
            ret.add(new InsnNode(Opcodes.FCONST_0));
            ret.add(new InsnNode(Opcodes.FRETURN));
            break;
        case Type.DOUBLE:
            ret.add(new InsnNode(Opcodes.DCONST_0));
            ret.add(new InsnNode(Opcodes.DRETURN));
            break;
        case Type.OBJECT:
        case Type.ARRAY:
            ret.add(new InsnNode(Opcodes.ACONST_NULL));
            ret.add(new InsnNode(Opcodes.ARETURN));
            break;
        default:
            throw new IllegalStateException();
    }

    return ret;
}
 

/**
 * Returns whether a given instruction can be used to push argument of {@code type} on stack.
 */
private /* static */ boolean isPushForType(AbstractInsnNode insn, Type type) {
  int opcode = insn.getOpcode();
  if (opcode == type.getOpcode(Opcodes.ILOAD)) {
    return true;
  }
  // b/62060793: AsyncAwait rewrites bytecode to convert java methods into state machine with
  // support of lambdas. Constant zero values are pushed on stack for all yet uninitialized
  // local variables. And SIPUSH instruction is used to advance an internal state of a state
  // machine.
  switch (type.getSort()) {
    case Type.BOOLEAN:
      return opcode == Opcodes.ICONST_0 || opcode == Opcodes.ICONST_1;

    case Type.BYTE:
    case Type.CHAR:
    case Type.SHORT:
    case Type.INT:
      return opcode == Opcodes.SIPUSH
          || opcode == Opcodes.ICONST_0
          || opcode == Opcodes.ICONST_1
          || opcode == Opcodes.ICONST_2
          || opcode == Opcodes.ICONST_3
          || opcode == Opcodes.ICONST_4
          || opcode == Opcodes.ICONST_5
          || opcode == Opcodes.ICONST_M1;

    case Type.LONG:
      return opcode == Opcodes.LCONST_0 || opcode == Opcodes.LCONST_1;

    case Type.FLOAT:
      return opcode == Opcodes.FCONST_0
          || opcode == Opcodes.FCONST_1
          || opcode == Opcodes.FCONST_2;

    case Type.DOUBLE:
      return opcode == Opcodes.DCONST_0 || opcode == Opcodes.DCONST_1;

    case Type.OBJECT:
    case Type.ARRAY:
      return opcode == Opcodes.ACONST_NULL;

    default:
      // Support for BIPUSH and LDC* opcodes is not implemented as there is no known use case.
      return false;
  }
}
 

/**
 * Compute sizes required for the storage arrays that will contain the operand stack at this frame.
 * @param frame frame to compute for
 * @param offset the position within the operand stack to start calculating
 * @param length the number of stack items to include in calculation
 * @return size required by each storage array
 * @throws NullPointerException if any argument is {@code null}
 * @throws IllegalArgumentException if any numeric argument is negative, or if {@code offset + length} is larger than the size of the
 * operand stack
 */
public static StorageSizes computeSizes(Frame<BasicValue> frame, int offset, int length) {
    Validate.notNull(frame);
    Validate.isTrue(offset >= 0);
    Validate.isTrue(length >= 0);
    Validate.isTrue(offset < frame.getStackSize());
    Validate.isTrue(offset + length <= frame.getStackSize());
    
    // Count size required for each storage array
    int intsSize = 0;
    int longsSize = 0;
    int floatsSize = 0;
    int doublesSize = 0;
    int objectsSize = 0;
    for (int i = offset + length - 1; i >= offset; i--) {
        BasicValue basicValue = frame.getStack(i);
        Type type = basicValue.getType();
        
        // If type is 'Lnull;', this means that the slot has been assigned null and that "there has been no merge yet that would 'raise'
        // the type toward some class or interface type" (from ASM mailing list). We know this slot will always contain null at this
        // point in the code so we can avoid saving it. When we load it back up, we can simply push a null in to that slot, thereby
        // keeping the same 'Lnull;' type.
        if ("Lnull;".equals(type.getDescriptor())) {
            continue;
        }
        
        switch (type.getSort()) {
            case Type.BOOLEAN:
            case Type.BYTE:
            case Type.SHORT:
            case Type.CHAR:
            case Type.INT:
                intsSize++;
                break;
            case Type.FLOAT:
                floatsSize++;
                break;
            case Type.LONG:
                longsSize++;
                break;
            case Type.DOUBLE:
                doublesSize++;
                break;
            case Type.ARRAY:
            case Type.OBJECT:
                objectsSize++;
                break;
            case Type.METHOD:
            case Type.VOID:
            default:
                throw new IllegalStateException();
        }
    }
    
    return new StorageSizes(intsSize, longsSize, floatsSize, doublesSize, objectsSize);
}