/*
 * 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.examples.analysis;

import com.ibm.wala.classLoader.IClass;
import com.ibm.wala.classLoader.IMethod;
import com.ibm.wala.core.util.config.AnalysisScopeReader;
import com.ibm.wala.ipa.callgraph.AnalysisScope;
import com.ibm.wala.ipa.cha.ClassHierarchyException;
import com.ibm.wala.ipa.cha.ClassHierarchyFactory;
import com.ibm.wala.ipa.cha.IClassHierarchy;
import java.io.IOException;

/**
 * This is a simple example WALA application.
 *
 * <p>This counts the number of parameters to each method in the primordial loader (the J2SE
 * standard libraries), and prints the result.
 *
 * @author sfink
 */
public class CountParameters {

  private static final ClassLoader MY_CLASSLOADER = CountParameters.class.getClassLoader();

  /** Use the 'CountParameters' launcher to run this program with the appropriate classpath */
  public static void main(String[] args) throws IOException, ClassHierarchyException {
    // build an analysis scope representing the standard libraries, excluding no classes
    AnalysisScope scope =
        AnalysisScopeReader.instance.readJavaScope("primordial.txt", null, MY_CLASSLOADER);

    // build a class hierarchy
    System.err.print("Build class hierarchy...");
    IClassHierarchy cha = ClassHierarchyFactory.make(scope);
    System.err.println("Done");

    int nClasses = 0;
    int nMethods = 0;
    int nParameters = 0;

    for (IClass c : cha) {
      nClasses++;
      for (IMethod m : c.getDeclaredMethods()) {
        nMethods++;
        nParameters += m.getNumberOfParameters();
      }
    }

    System.out.println(nClasses + " classes");
    System.out.println(nMethods + " methods");
    System.out.println((float) nParameters / (float) nMethods + " parameters per method");
  }
}
