/******************************************************************************
 * Copyright (c) 2002 - 2006 IBM Corporation.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 *****************************************************************************/
package com.ibm.wala.cast.ipa.callgraph;

import java.util.Iterator;

import com.ibm.wala.cast.loader.AstMethod;
import com.ibm.wala.classLoader.CallSiteReference;
import com.ibm.wala.classLoader.CodeScanner;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.classLoader.NewSiteReference;
import com.ibm.wala.ipa.callgraph.AnalysisCache;
import com.ibm.wala.ipa.callgraph.AnalysisOptions;
import com.ibm.wala.ipa.callgraph.CGNode;
import com.ibm.wala.ipa.callgraph.Context;
import com.ibm.wala.ipa.callgraph.propagation.cfa.ContextInsensitiveSSAInterpreter;
import com.ibm.wala.ssa.IR;
import com.ibm.wala.util.collections.EmptyIterator;

/**
 * A version of {@link ContextInsensitiveSSAInterpreter} that uses the IR for
 * {@link #iterateNewSites(CGNode)} and {@link #iterateCallSites(CGNode)} when
 * we have an {@link AstMethod}. ({@link ContextInsensitiveSSAInterpreter}
 * defaults to using {@link CodeScanner}, which only works for bytecodes.)
 */
public class AstContextInsensitiveSSAContextInterpreter extends ContextInsensitiveSSAInterpreter {

  public AstContextInsensitiveSSAContextInterpreter(AnalysisOptions options, AnalysisCache cache) {
    super(options, cache);
  }

  public boolean understands(IMethod method, Context context) {
    return method instanceof AstMethod;
  }

  @Override
  public Iterator<NewSiteReference> iterateNewSites(CGNode N) {
    IR ir = getIR(N);
    if (ir == null) {
      return EmptyIterator.instance();
    } else {
      return ir.iterateNewSites();
    }
  }

  @Override
  public Iterator<CallSiteReference> iterateCallSites(CGNode N) {
    IR ir = getIR(N);
    if (ir == null) {
      return EmptyIterator.instance();
    } else {
      return ir.iterateCallSites();
    }
  }

}