Package com.ibm.wala.fixedpoint.impl

Class GeneralStatement<T extends IVariable<T>>

java.lang.Object
com.ibm.wala.util.graph.impl.NodeWithNumber
com.ibm.wala.fixpoint.AbstractStatement<T,AbstractOperator<T>>
com.ibm.wala.fixedpoint.impl.GeneralStatement<T>
All Implemented Interfaces:
IFixedPointStatement<T>, INodeWithNumber
Direct Known Subclasses:
AbstractFixedPointSolver.Statement
public abstract class GeneralStatement<T extends IVariable<T>> extends AbstractStatement<T,AbstractOperator<T>>
Represents a single step in an iterative solver

  • Field Details

  • Constructor Details

    • GeneralStatement

      public GeneralStatement(T lhs, AbstractOperator<T> operator)
      Constructor for case of zero operands on the right-hand side.
      Parameters:
      lhs - the lattice cell set by this equation
      operator - the equation operator

    • GeneralStatement

      public GeneralStatement(T lhs, AbstractOperator<T> operator, T op1, T op2)
      Constructor for case of two operands on the right-hand side.
      Parameters:
      lhs - the lattice cell set by this equation
      operator - the equation operator
      op1 - the first operand on the rhs
      op2 - the second operand on the rhs

    • GeneralStatement

      public GeneralStatement(T lhs, AbstractOperator<T> operator, T op1, T op2, T op3)
      Constructor for case of three operands on the right-hand side.
      Parameters:
      lhs - the lattice cell set by this equation
      operator - the equation operator
      op1 - the first operand on the rhs
      op2 - the second operand on the rhs
      op3 - the third operand on the rhs

    • GeneralStatement

      public GeneralStatement(T lhs, AbstractOperator<T> operator, T[] rhs)
      Constructor for case of more than three operands on the right-hand side.
      Parameters:
      lhs - the lattice cell set by this equation
      operator - the equation operator
      rhs - the operands of the right-hand side in order
      Throws:
      IllegalArgumentException - if rhs is null

  • Method Details

    • evaluate

      public byte evaluate()
      Evaluate this equation, setting a new value for the left-hand side.
      Returns:
      true if the lhs value changed. false otherwise

    • getLHS

      public T getLHS()
      Return the left-hand side of this equation.
      Returns:
      the lattice cell this equation computes

    • hasVariable

      public boolean hasVariable(T cell)
      Does this equation contain an appearance of a given cell? Note: this uses reference equality, assuming that the variables are canonical! This is fragile. TODO: Address it perhaps, but be careful not to sacrifice efficiency.
      Parameters:
      cell - the cell in question
      Returns:
      true or false

    • makeRHS

      protected abstract T[] makeRHS(int size)

    • hashCode

      public int hashCode()
      Description copied from class: AbstractStatement
      Subclasses must implement this, to prevent non-determinism.
      Specified by:
      hashCode in class AbstractStatement<T extends IVariable<T>,AbstractOperator<T extends IVariable<T>>>

    • equals

      public boolean equals(Object o)
      Specified by:
      equals in class AbstractStatement<T extends IVariable<T>,AbstractOperator<T extends IVariable<T>>>

    • getOperator

      public AbstractOperator<T> getOperator()
      Specified by:
      getOperator in class AbstractStatement<T extends IVariable<T>,AbstractOperator<T extends IVariable<T>>>

    • getRHS

      public T[] getRHS()
      Description copied from interface: IFixedPointStatement
      returns the list of free variables appearing in the right-hand side of the statement