opcodes.scala

来自「JAVA 语言的函数式编程扩展」· SCALA 代码 · 共 646 行 · 第 1/2 页

      }
      
      override def consumedTypes = {
        val args = method.tpe.paramTypes map toTypeKind
        style match {
          case Dynamic | Static(true) => AnyRefReference :: args
          case _ => args
        }
      }
      
      override def produced = 
        if(toTypeKind(method.tpe.resultType) == UNIT)
          0
        else if(method.isConstructor)
          0
        else 1
        
      /** object idenity is equality for CALL_METHODs. Needed for
       *  being able to store such instructions into maps, when more
       *  than one CALL_METHOD to the same method might exist.
       */
      override def equals(other: Any) = other match {
        case o: AnyRef => this eq o
        case _ => false
      }
    }

    case class BOX(boxType: TypeKind) extends Instruction {
      override def toString(): String = "BOX " + boxType
      override def consumed = 1
      override def consumedTypes = boxType :: Nil
      override def produced = 1
    }

    case class UNBOX(boxType: TypeKind) extends Instruction {
      override def toString(): String = "UNBOX " + boxType
      override def consumed = 1
      override def consumedTypes = AnyRefReference :: Nil
      override def produced = 1
    }

    /** Create a new instance of a class through the specified constructor
     * Stack: ...:arg1:arg2:...:argn
     *    ->: ...:ref
     */
    case class NEW(kind: REFERENCE) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String = "NEW "+ kind;

      override def consumed = 0;
      override def produced = 1;
      
      /** The corresponding constructor call. */
      var init: CALL_METHOD = _
    }


    /** This class represents a CREATE_ARRAY instruction
     * Stack: ...:size_1:size_2:..:size_n
     *    ->: ...:arrayref
     */
    case class CREATE_ARRAY(elem: TypeKind, dims: Int) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="CREATE_ARRAY "+elem.toString() + " x " + dims;

      override def consumed = dims;
      override def consumedTypes = List.make(dims, INT)
      override def produced = 1;
    }

    /** This class represents a IS_INSTANCE instruction
     * Stack: ...:ref
     *    ->: ...:result(boolean)
     */
    case class IS_INSTANCE(typ: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="IS_INSTANCE "+typ.toString()

      override def consumed = 1
      override def consumedTypes = AnyRefReference :: Nil
      override def produced = 1
    }

    /** This class represents a CHECK_CAST instruction
     * Stack: ...:ref(oldtype)
     *    ->: ...:ref(typ <=: oldtype)
     */
    case class CHECK_CAST(typ: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="CHECK_CAST "+typ.toString()

      override def consumed = 1
      override def produced = 1
      override val consumedTypes = List(AnyRefReference)
      override def producedTypes = List(typ)
    }

    /** This class represents a SWITCH instruction
     * Stack: ...:index(int)
     *    ->: ...:
     * 
     * The tags array contains one entry per label, each entry consisting of
     * an array of ints, any of which will trigger the jump to the corresponding label.
     * labels should contain an extra label, which is the 'default' jump.
     */
    case class SWITCH(tags: List[List[Int]], labels: List[BasicBlock]) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="SWITCH ..."

      override def consumed = 1
      override def produced = 0
    }

    /** This class represents a JUMP instruction
     * Stack: ...
     *    ->: ...
     */
    case class JUMP(whereto: BasicBlock) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="JUMP "+whereto.label

      override def consumed = 0
      override def produced = 0
    }

    /** This class represents a CJUMP instruction
     * It compares the two values on the stack with the 'cond' test operator
     * Stack: ...:value1:value2
     *    ->: ...
     */
    case class CJUMP(successBlock: BasicBlock, 
		     failureBlock: BasicBlock, 
		     cond: TestOp,
                     kind: TypeKind) extends Instruction 
    {
      
      /** Returns a string representation of this instruction */
      override def toString(): String = (
        "CJUMP (" + kind + ")" + 
        cond.toString()+" ? "+successBlock.label+" : "+failureBlock.label
      );
      
      override def consumed = 2
      override def produced = 0
    }

    /** This class represents a CZJUMP instruction
     * It compares the one value on the stack and zero with the 'cond' test operator
     * Stack: ...:value:
     *    ->: ...
     */
    case class CZJUMP(successBlock: BasicBlock, 
                      failureBlock: BasicBlock, 
                      cond: TestOp,
                      kind: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String = (
        "CZJUMP (" + kind + ")" + 
        cond.toString()+" ? "+successBlock.label+" : "+failureBlock.label
      );

      override def consumed = 1
      override def produced = 0
    }

    
    /** This class represents a RETURN instruction
     * Stack: ...
     *    ->: ...
     */
    case class RETURN(kind: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="RETURN (" + kind + ")"

      override def consumed = if (kind == UNIT) 0 else 1
      override def produced = 0
    }

    /** This class represents a THROW instruction
     * Stack: ...:Throwable(Ref)
     *    ->: ...:
     */
    case class THROW() extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="THROW"

      override def consumed = 1
      override def produced = 0
    }

    /** This class represents a DROP instruction
     * Stack: ...:something
     *    ->: ...
     */
    case class DROP (typ: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="DROP "+typ.toString()

      override def consumed = 1
      override def produced = 0
    }
    
    /** This class represents a DUP instruction
     * Stack: ...:something
     *    ->: ...:something:something
     */
    case class DUP (typ: TypeKind) extends Instruction {
      /** Returns a string representation of this instruction */
      override def toString(): String ="DUP"
      
      override def consumed = 1
      override def produced = 2
    }

    /** This class represents a MONITOR_ENTER instruction
     * Stack: ...:object(ref)
     *    ->: ...:
     */
    case class MONITOR_ENTER() extends Instruction {
      
      /** Returns a string representation of this instruction */
      override def toString(): String ="MONITOR_ENTER"
      
      override def consumed = 1
      override def produced = 0
    }

    /** This class represents a MONITOR_EXIT instruction
     * Stack: ...:object(ref)
     *    ->: ...:
     */
    case class MONITOR_EXIT() extends Instruction {
      
      /** Returns a string representation of this instruction */
      override def toString(): String ="MONITOR_EXIT";
      
      override def consumed = 1;
      override def produced = 0;
    }
     
    /** A local variable becomes visible at this point in code. 
     *  Used only for generating precise local variable tables as
     *  debugging information.
     */
    case class SCOPE_ENTER(lv: Local) extends Instruction {
      override def toString(): String = "SCOPE_ENTER " + lv
      override def consumed = 0
      override def produced = 0
    }

    /** A local variable leaves its scope at this point in code. 
     *  Used only for generating precise local variable tables as
     *  debugging information.
     */
    case class SCOPE_EXIT(lv: Local) extends Instruction {
      override def toString(): String = "SCOPE_EXIT " + lv
      override def consumed = 0
      override def produced = 0
    }
    
    /** Fake instruction. It designates the VM who pushes an exception
     *  on top of the /empty/ stack at the beginning of each exception handler.
     *  Note: Unlike other instructions, it consumes all elements on the stack!
     *        then pushes one exception instance.
     */
    case class LOAD_EXCEPTION() extends Instruction {
      override def toString(): String = "LOAD_EXCEPTION"
      override def consumed = error("LOAD_EXCEPTION does clean the whole stack, no idea how many things it consumes!")
      override def produced = 1
      override def producedTypes = AnyRefReference :: Nil
    }

    /** This class represents a method invocation style. */
    sealed abstract class InvokeStyle {

      /** Is this a dynamic method call? */
      def isDynamic: Boolean = this match {
        case Dynamic =>  true
        case _       => false
      }

      /** Is this a static method call? */
      def isStatic: Boolean = this match {
        case Static(_) => true
        case _ =>  false
      }

      def isSuper: Boolean = this match {
        case SuperCall(_) => true
        case _ => false
      }

      /** Is this an instance method call? */
      def hasInstance: Boolean = this match {
        case Dynamic => true
        case Static(onInstance) => onInstance
        case SuperCall(_) => true
        case _ => false
      }

      /** Returns a string representation of this style. */
      override def toString(): String = this match {
        case Dynamic =>  "dynamic"
        case Static(false) => "static-class"
        case Static(true) =>  "static-instance"
        case SuperCall(mix) => "super(" + mix + ")"
      }
    }

    case object Dynamic extends InvokeStyle
    
    /** 
     * Special invoke. Static(true) is used for calls to private
     * members.
     */
    case class Static(onInstance: Boolean) extends InvokeStyle
    
    /** Call through super[mix]. */
    case class SuperCall(mix: Name) extends InvokeStyle

  }
}