DCD xref

 /**
  * BSD-style license; for more info see http://pmd.sourceforge.net/license.html 
  */
 package net.sourceforge.pmd.dcd;
 
 import java.io.File;
 import java.io.FilenameFilter;
 import java.util.ArrayList;
 import java.util.Arrays;
 import java.util.List;
 
 import net.sourceforge.pmd.dcd.graph.UsageGraph;
 import net.sourceforge.pmd.dcd.graph.UsageGraphBuilder;
 import net.sourceforge.pmd.util.FileFinder;
 import net.sourceforge.pmd.util.filter.Filter;
 import net.sourceforge.pmd.util.filter.Filters;
 
 /**
  * The Dead Code Detector is used to find dead code. What is dead code?
  * Dead code is code which is not used by other code? It exists, but it not
  * used. Unused code is clutter, which can generally be a candidate for
  * removal.
  * <p>
  * When performing dead code detection, there are various sets of files/classes
  * which must be identified. An analogy of the dead code analysis as
  * a <em>foot race</em> is used to help clarify each of these sets:
  * <ol>
  * <li>The <em>direct users</em> is the set of Classes which will always be
  * parsed to determine what code they use. This set is the starting point of
  * the race.</li>
  * <li>The <em>indirect users</em> is the set of Classes which will only be
  * parsed if they are accessed by code in the <em>direct users</em> set, or
  * in the <em>indirect users</em> set. This set is the course of the race.</li>
  * <li>The <em>dead code candidates</em> are the set of Classes which are the
  * focus of the dead code detection. This set is the finish line of the
  * race.</li>
  * </ol>
  * <p>
  * Typically there is intersection between the set of <em>direct users</em>,
  * <em>indirect users</em> and <em>dead code candidates</em>, although it is
  * not required. If the sets are defined too tightly, there the potential for
  * a lot of code to be considered as dead code. You may need to expand the
  * <em>direct users</em> or <em>indirect users</em> sets, or explore using
  * different options.
  *
  * @author Ryan Gustafson <ryan.gustafson@gmail.com>,
  */
 public class DCD {
 	//
 	// TODO Implement the direct users, indirect users, and dead code
 	// candidate sets. Use the pmd.util.filter.Filter APIs. Need to come up
 	// with something like Ant's capabilities for <fileset>, it's a decent way
 	// to describe a collection of files in a directory structure. That or we
 	// just adopt Ant, and screw command line/external configuration?
 	//
 	// TODO Better yet, is there a way to enumerate all available classes using
 	// ClassLoaders instead of having to specify Java file names as surrogates
 	// for the Classes we truly desire?
 	//
 	// TODO Methods defined on classes/interfaces not within the scope of
 	// analysis which are implemented/overridden, are not usage violations.
 	//
 	// TODO Static final String and primitive types are often inlined by the
 	// compiler, so there may actually be no explicit usages.
 	//
 	// TODO Ignore "public static void main(String[])"
 	//
 	// TODO Check for method which is always overridden, and never called
 	// directly.
 	//
 	// TODO For methods, record which classes/interfaces methods they are
 	// overriding/implementing.
 	//
 	// TODO Allow recognition of indirect method patterns, like those used by
 	// EJB Home and Remote interfaces with corresponding implementation classes.
 	//
 	// TODO
 	// 1) For each class/member, a set of other class/members which reference.
 	// 2) For every class/member which is part of an interface or super-class,
 	// allocate those references to the interface/super-class.
 	//
 
 	public static void dump(UsageGraph usageGraph, boolean verbose) {
 		usageGraph.accept(new DumpNodeVisitor(), Boolean.valueOf(verbose));
 	}
 
 	public static void report(UsageGraph usageGraph, boolean verbose) {
 		usageGraph.accept(new UsageNodeVisitor(), Boolean.valueOf(verbose));
 	}
 
 	public static void main(String[] args) throws Exception {
 		// 1) Directories
 		List<File> directories = new ArrayList<File>();
 		directories.add(new File("C:/pmd/workspace/pmd-trunk/src"));
 
 		// Basic filter
 		FilenameFilter javaFilter = new FilenameFilter() {
 			public boolean accept(File dir, String name) {
 				// Recurse on directories
 				if (new File(dir, name).isDirectory()) {
 					return true;
 				} else {
 					return name.endsWith(".java");
 				}
 			}
 		};
 
 		// 2) Filename filters
 		List<FilenameFilter> filters = new ArrayList<FilenameFilter>();
 		filters.add(javaFilter);
 
 		assert directories.size() == filters.size();
 
 		// Find all files, convert to class names
 		List<String> classes = new ArrayList<String>();
 		for (int i = 0; i < directories.size(); i++) {
 			File directory = directories.get(i);
 			FilenameFilter filter = filters.get(i);
 			List<File> files = new FileFinder().findFilesFrom(directory.getPath(), filter, true);
 			for (File file : files) {
 				String name = file.getPath();
 
 				// Chop off directory
 				name = name.substring(directory.getPath().length() + 1);
 
 				// Drop extension
 				name = name.replaceAll("\\.java$", "");
 
 				// Trim path separators
 				name = name.replace('\\', '.');
 				name = name.replace('/', '.');
 
 				classes.add(name);
 			}
 		}
 
 		long start = System.currentTimeMillis();
 
 		// Define filter for "indirect users" and "dead code candidates".
 		// TODO Need to support these are different concepts.
 		List<String> includeRegexes = Arrays.asList(new String[] { "net\\.sourceforge\\.pmd\\.dcd.*", "us\\..*" });
 		List<String> excludeRegexes = Arrays.asList(new String[] { "java\\..*", "javax\\..*", ".*\\.twa\\..*" });
 		Filter<String> classFilter = Filters.buildRegexFilterExcludeOverInclude(includeRegexes, excludeRegexes);
 		System.out.println("Class filter: " + classFilter);
 
 		// Index each of the "direct users"
 		UsageGraphBuilder builder = new UsageGraphBuilder(classFilter);
 		int total = 0;
 		for (String clazz : classes) {
 			System.out.println("indexing class: " + clazz);
 			builder.index(clazz);
 			total++;
 			if (total % 20 == 0) {
 				System.out.println(total + " : " + total / ((System.currentTimeMillis() - start) / 1000.0));
 			}
 		}
 
 		// Reporting
 		boolean dump = true;
 		boolean deadCode = true;
 		UsageGraph usageGraph = builder.getUsageGraph();
 		if (dump) {
 			System.out.println("--- Dump ---");
 			dump(usageGraph, true);
 		}
 		if (deadCode) {
 			System.out.println("--- Dead Code ---");
 			report(usageGraph, true);
 		}
 		long end = System.currentTimeMillis();
 		System.out.println("Time: " + (end - start) / 1000.0);
 	}
 }