Package serp.bytecode

Class ConstantInstruction

  • All Implemented Interfaces:
    BCEntity, VisitAcceptor

    public class ConstantInstruction
    extends TypedInstruction
    An instruction that that loads a constant onto the stack. The opcode represented by this instruction may change depending on the type and value of the constant set. For example, if the constant value is initially set to 5, the opcode will be iconst5; if later incremented to 6, the opcode will be changed to bipush(6).
    Author:
    Abe White
    • Method Detail

      • getStackChange

        public int getStackChange()
        Description copied from class: Instruction
        Return the number of stack positions this instruction pushes or pops during its execution.
        Overrides:
        getStackChange in class Instruction
        Returns:
        0 if the stack is not affected by this instruction, a positive number if it pushes onto the stack, and a negative number if it pops from the stack
      • getLogicalStackChange

        public int getLogicalStackChange()
        Description copied from class: Instruction
        Return the logical number of stack positions changed by this instruction. In other words, ignore weirdness with longs and doubles taking two stack positions.
        Overrides:
        getLogicalStackChange in class Instruction
      • getTypeName

        public java.lang.String getTypeName()
        Description copied from class: TypedInstruction
        Return the type name for this instruction. If the type has not been set, this method will return null.
        Specified by:
        getTypeName in class TypedInstruction
      • setType

        public TypedInstruction setType​(java.lang.String type)
        Description copied from class: TypedInstruction
        Set the type of this instruction. Types that have no direct support will be converted accordingly.
        Specified by:
        setType in class TypedInstruction
        Returns:
        this instruction, for method chaining
      • getValue

        public java.lang.Object getValue()
        Return the value of the constant as its wrapper type, or null if not set. Returns class values as the class name.
      • setValue

        public ConstantInstruction setValue​(java.lang.Object value)
        Set the constant to the given value. The value should be an instance of String, Integer, Long, Double, Float, Class, BCClass, or null depending on the constant type. If the given value is not supported directly, it will be converted accordingly.
        Returns:
        this instruction, for method chaining
      • getStringValue

        public java.lang.String getStringValue()
        Return the string value of this constant, or null if not set.
      • getIntValue

        public int getIntValue()
        Return the int value of this constant, or 0 if not set.
      • getLongValue

        public long getLongValue()
        Return the long value of this constant, or 0 if not set.
      • getFloatValue

        public float getFloatValue()
        Return the float value of this constant, or 0 if not set.
      • getDoubleValue

        public double getDoubleValue()
        Return the double value of this constant, or 0 if not set.
      • getClassNameValue

        public java.lang.String getClassNameValue()
        Return the class value of this constant, or null if not set.
      • setNull

        public ConstantInstruction setNull()
        Set this constant to null.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(java.lang.String value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(java.lang.Class value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(BCClass value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(int value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(long value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(float value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(double value)
        Set the value of this constant.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(boolean value)
        Set the value of this constant; note that this type is converted to int.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(short value)
        Set the value of this constant; note that this type is converted to int.
        Returns:
        this instruction, for method chaining
      • setValue

        public ConstantInstruction setValue​(char value)
        Set the value of this constant; note that this type is converted to int.
        Returns:
        this instruction, for method chaining
      • equalsInstruction

        public boolean equalsInstruction​(Instruction other)
        ConstantInstructions are equal if the const they reference is the same, or if the const of either is unset.
        Overrides:
        equalsInstruction in class Instruction
      • acceptVisit

        public void acceptVisit​(BCVisitor visit)
        Description copied from interface: VisitAcceptor
        Accept a visit from a BCVisitor, calling the appropriate methods to notify the visitor that it has entered this entity, and to provide it with the proper callbacks for each sub-entity owned by this one.
        Specified by:
        acceptVisit in interface VisitAcceptor
        Overrides:
        acceptVisit in class Instruction