package com.ibm.wala.cast.js.ssa;

import java.util.Collection;

import com.ibm.wala.ssa.SSAInstruction;
import com.ibm.wala.ssa.SSAInstructionFactory;
import com.ibm.wala.ssa.SymbolTable;
import com.ibm.wala.types.TypeReference;

public class JavaScriptWithRegion extends SSAInstruction {
  private final int expr;
  private final boolean isEnter;
  
  public JavaScriptWithRegion(int expr, boolean isEnter) {
    this.expr = expr;
    this.isEnter = isEnter;
  }

  @Override
  public SSAInstruction copyForSSA(SSAInstructionFactory insts, int[] defs, int[] uses) {
    return ((JSInstructionFactory)insts).WithRegion(uses==null? expr: uses[0], isEnter);
  }

  @Override
  public Collection<TypeReference> getExceptionTypes() {
     return null;
  }

  @Override
  public int hashCode() {
    return 353456 * expr * (isEnter? 1 : -1);
  }

  @Override
  public boolean isFallThrough() {
    return true;
  }

  @Override
  public String toString(SymbolTable symbolTable) {
    return (isEnter? "enter": "exit") + " of with " + getValueString(symbolTable, expr);
  }

  @Override
  public void visit(IVisitor v) {
    ((JSInstructionVisitor)v).visitWithRegion(this);
  }

  public int getNumberOfUses() {
    return 1;
  }
  
  public int getUse(int i) {
    assert i == 0;
    return expr;
  }
  
}