src/jdk.compiler/share/classes/com/sun/tools/sjavac/comp/SjavacImpl.java - platform/libcore - Git at Google

 /*
  * Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
  *
  * This code is free software; you can redistribute it and/or modify it
  * under the terms of the GNU General Public License version 2 only, as
  * published by the Free Software Foundation.  Oracle designates this
  * particular file as subject to the "Classpath" exception as provided
  * by Oracle in the LICENSE file that accompanied this code.
  *
  * This code is distributed in the hope that it will be useful, but WITHOUT
  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License
  * version 2 for more details (a copy is included in the LICENSE file that
  * accompanied this code).
  *
  * You should have received a copy of the GNU General Public License version
  * 2 along with this work; if not, write to the Free Software Foundation,
  * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
  *
  * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
  * or visit www.oracle.com if you need additional information or have any
  * questions.
  */

 package com.sun.tools.sjavac.comp;

 import java.io.IOException;
 import java.io.PrintWriter;
 import java.io.StringWriter;
 import java.nio.file.Files;
 import java.nio.file.Path;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.HashMap;
 import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.Set;
 import java.util.stream.Stream;

 import com.sun.tools.javac.file.JavacFileManager;
 import com.sun.tools.javac.main.Main;
 import com.sun.tools.javac.main.Main.Result;
 import com.sun.tools.javac.util.Context;
 import com.sun.tools.sjavac.JavacState;
 import com.sun.tools.sjavac.Log;
 import com.sun.tools.sjavac.Module;
 import com.sun.tools.sjavac.ProblemException;
 import com.sun.tools.sjavac.Source;
 import com.sun.tools.sjavac.Transformer;
 import com.sun.tools.sjavac.Util;
 import com.sun.tools.sjavac.options.Option;
 import com.sun.tools.sjavac.options.Options;
 import com.sun.tools.sjavac.options.SourceLocation;
 import com.sun.tools.sjavac.server.Sjavac;
 import java.io.UncheckedIOException;

 import javax.tools.JavaFileManager;

 /**
  * The sjavac implementation that interacts with javac and performs the actual
  * compilation.
  *
  *  <p><b>This is NOT part of any supported API.
  *  If you write code that depends on this, you do so at your own risk.
  *  This code and its internal interfaces are subject to change or
  *  deletion without notice.</b>
  */
 public class SjavacImpl implements Sjavac {

     @Override
     public Result compile(String[] args) {
         Options options;
         try {
             options = Options.parseArgs(args);
         } catch (IllegalArgumentException e) {
             Log.error(e.getMessage());
             return Result.CMDERR;
         }

         if (!validateOptions(options))
             return Result.CMDERR;

         if (srcDstOverlap(options.getSources(), options.getDestDir())) {
             return Result.CMDERR;
         }

         if (!createIfMissing(options.getDestDir()))
             return Result.ERROR;

         Path stateDir = options.getStateDir();
         if (stateDir != null && !createIfMissing(options.getStateDir()))
             return Result.ERROR;

         Path gensrc = options.getGenSrcDir();
         if (gensrc != null && !createIfMissing(gensrc))
             return Result.ERROR;

         Path hdrdir = options.getHeaderDir();
         if (hdrdir != null && !createIfMissing(hdrdir))
             return Result.ERROR;

         if (stateDir == null) {
             // Prepare context. Direct logging to our byte array stream.
             Context context = new Context();
             StringWriter strWriter = new StringWriter();
             PrintWriter printWriter = new PrintWriter(strWriter);
             com.sun.tools.javac.util.Log.preRegister(context, printWriter);
             JavacFileManager.preRegister(context);

             // Prepare arguments
             String[] passThroughArgs = Stream.of(args)
                                              .filter(arg -> !arg.startsWith(Option.SERVER.arg))
                                              .toArray(String[]::new);
             // Compile
             Result result = new Main("javac", printWriter).compile(passThroughArgs, context);

             // Process compiler output (which is always errors)
             printWriter.flush();
             Util.getLines(strWriter.toString()).forEach(Log::error);

             // Clean up
             JavaFileManager fileManager = context.get(JavaFileManager.class);
             if (fileManager instanceof JavacFileManager) {
                 try {
                     ((JavacFileManager) fileManager).close();
                 } catch (IOException es) {
                     throw new UncheckedIOException(es);
                 }
             }
             return result;

         } else {
             // Load the prev build state database.
             JavacState javac_state = JavacState.load(options);

             // Setup the suffix rules from the command line.
             Map<String, Transformer> suffixRules = new HashMap<>();

             // Handling of .java-compilation
             suffixRules.putAll(javac_state.getJavaSuffixRule());

             // Handling of -copy and -tr
             suffixRules.putAll(options.getTranslationRules());

             // All found modules are put here.
             Map<String,Module> modules = new HashMap<>();
             // We start out in the legacy empty no-name module.
             // As soon as we stumble on a module-info.java file we change to that module.
             Module current_module = new Module("", "");
             modules.put("", current_module);

             try {
                 // Find all sources, use the suffix rules to know which files are sources.
                 Map<String,Source> sources = new HashMap<>();

                 // Find the files, this will automatically populate the found modules
                 // with found packages where the sources are found!
                 findSourceFiles(options.getSources(),
                                 suffixRules.keySet(),
                                 sources,
                                 modules,
                                 current_module,
                                 options.isDefaultPackagePermitted(),
                                 false);

                 if (sources.isEmpty()) {
                     Log.error("Found nothing to compile!");
                     return Result.ERROR;
                 }


                 // Create a map of all source files that are available for linking. Both -src and
                 // -sourcepath point to such files. It is possible to specify multiple
                 // -sourcepath options to enable different filtering rules. If the
                 // filters are the same for multiple sourcepaths, they may be concatenated
                 // using :(;). Before sending the list of sourcepaths to javac, they are
                 // all concatenated. The list created here is used by the SmartFileWrapper to
                 // make sure only the correct sources are actually available.
                 // We might find more modules here as well.
                 Map<String,Source> sources_to_link_to = new HashMap<>();

                 List<SourceLocation> sourceResolutionLocations = new ArrayList<>();
                 sourceResolutionLocations.addAll(options.getSources());
                 sourceResolutionLocations.addAll(options.getSourceSearchPaths());
                 findSourceFiles(sourceResolutionLocations,
                                 Collections.singleton(".java"),
                                 sources_to_link_to,
                                 modules,
                                 current_module,
                                 options.isDefaultPackagePermitted(),
                                 true);

                 // Add the set of sources to the build database.
                 javac_state.now().flattenPackagesSourcesAndArtifacts(modules);
                 javac_state.now().checkInternalState("checking sources", false, sources);
                 javac_state.now().checkInternalState("checking linked sources", true, sources_to_link_to);
                 javac_state.setVisibleSources(sources_to_link_to);

                 int round = 0;
                 printRound(round);

                 // If there is any change in the source files, taint packages
                 // and mark the database in need of saving.
                 javac_state.checkSourceStatus(false);

                 // Find all existing artifacts. Their timestamp will match the last modified timestamps stored
                 // in javac_state, simply because loading of the JavacState will clean out all artifacts
                 // that do not match the javac_state database.
                 javac_state.findAllArtifacts();

                 // Remove unidentified artifacts from the bin, gensrc and header dirs.
                 // (Unless we allow them to be there.)
                 // I.e. artifacts that are not known according to the build database (javac_state).
                 // For examples, files that have been manually copied into these dirs.
                 // Artifacts with bad timestamps (ie the on disk timestamp does not match the timestamp
                 // in javac_state) have already been removed when the javac_state was loaded.
                 if (!options.areUnidentifiedArtifactsPermitted()) {
                     javac_state.removeUnidentifiedArtifacts();
                 }
                 // Go through all sources and taint all packages that miss artifacts.
                 javac_state.taintPackagesThatMissArtifacts();

                 // Check recorded classpath public apis. Taint packages that depend on
                 // classpath classes whose public apis have changed.
                 javac_state.taintPackagesDependingOnChangedClasspathPackages();

                 // Now clean out all known artifacts belonging to tainted packages.
                 javac_state.deleteClassArtifactsInTaintedPackages();
                 // Copy files, for example property files, images files, xml files etc etc.
                 javac_state.performCopying(Util.pathToFile(options.getDestDir()), suffixRules);
                 // Translate files, for example compile properties or compile idls.
                 javac_state.performTranslation(Util.pathToFile(gensrc), suffixRules);
                 // Add any potentially generated java sources to the tobe compiled list.
                 // (Generated sources must always have a package.)
                 Map<String,Source> generated_sources = new HashMap<>();

                 Source.scanRoot(Util.pathToFile(options.getGenSrcDir()),
                                 Util.set(".java"),
                                 Collections.emptyList(),
                                 Collections.emptyList(),
                                 generated_sources,
                                 modules,
                                 current_module,
                                 false,
                                 true,
                                 false);
                 javac_state.now().flattenPackagesSourcesAndArtifacts(modules);
                 // Recheck the the source files and their timestamps again.
                 javac_state.checkSourceStatus(true);

                 // Now do a safety check that the list of source files is identical
                 // to the list Make believes we are compiling. If we do not get this
                 // right, then incremental builds will fail with subtility.
                 // If any difference is detected, then we will fail hard here.
                 // This is an important safety net.
                 javac_state.compareWithMakefileList(Util.pathToFile(options.getSourceReferenceList()));

                 // Do the compilations, repeatedly until no tainted packages exist.
                 boolean again;
                 // Collect the name of all compiled packages.
                 Set<String> recently_compiled = new HashSet<>();
                 boolean[] rc = new boolean[1];

                 CompilationService compilationService = new CompilationService();
                 do {
                     if (round > 0)
                         printRound(round);
                     // Clean out artifacts in tainted packages.
                     javac_state.deleteClassArtifactsInTaintedPackages();
                     again = javac_state.performJavaCompilations(compilationService,
                                                                 options,
                                                                 recently_compiled,
                                                                 rc);
                     if (!rc[0]) {
                         Log.debug("Compilation failed.");
                         break;
                     }
                     if (!again) {
                         Log.debug("Nothing left to do.");
                     }
                     round++;
                 } while (again);
                 Log.debug("No need to do another round.");

                 // Only update the state if the compile went well.
                 if (rc[0]) {
                     javac_state.save();
                     // Reflatten only the artifacts.
                     javac_state.now().flattenArtifacts(modules);
                     // Remove artifacts that were generated during the last compile, but not this one.
                     javac_state.removeSuperfluousArtifacts(recently_compiled);
                 }

                 return rc[0] ? Result.OK : Result.ERROR;
             } catch (ProblemException e) {
                 // For instance make file list mismatch.
                 Log.error(e.getMessage());
                 Log.debug(e);
                 return Result.ERROR;
             } catch (Exception e) {
                 Log.error(e);
                 return Result.ERROR;
             }
         }
     }

     @Override
     public void shutdown() {
         // Nothing to clean up
     }

     private static boolean validateOptions(Options options) {

         String err = null;

         if (options.getDestDir() == null) {
             err = "Please specify output directory.";
         } else if (options.isJavaFilesAmongJavacArgs()) {
             err = "Sjavac does not handle explicit compilation of single .java files.";
         } else if (!options.getImplicitPolicy().equals("none")) {
             err = "The only allowed setting for sjavac is -implicit:none";
         } else if (options.getSources().isEmpty() && options.getStateDir() != null) {
             err = "You have to specify -src when using --state-dir.";
         } else if (options.getTranslationRules().size() > 1
                 && options.getGenSrcDir() == null) {
             err = "You have translators but no gensrc dir (-s) specified!";
         }

         if (err != null)
             Log.error(err);

         return err == null;

     }

     private static boolean srcDstOverlap(List<SourceLocation> locs, Path dest) {
         for (SourceLocation loc : locs) {
             if (isOverlapping(loc.getPath(), dest)) {
                 Log.error("Source location " + loc.getPath() + " overlaps with destination " + dest);
                 return true;
             }
         }
         return false;
     }

     private static boolean isOverlapping(Path p1, Path p2) {
         p1 = p1.toAbsolutePath().normalize();
         p2 = p2.toAbsolutePath().normalize();
         return p1.startsWith(p2) || p2.startsWith(p1);
     }

     private static boolean createIfMissing(Path dir) {

         if (Files.isDirectory(dir))
             return true;

         if (Files.exists(dir)) {
             Log.error(dir + " is not a directory.");
             return false;
         }

         try {
             Files.createDirectories(dir);
         } catch (IOException e) {
             Log.error("Could not create directory: " + e.getMessage());
             return false;
         }

         return true;
     }

     /** Find source files in the given source locations. */
     public static void findSourceFiles(List<SourceLocation> sourceLocations,
                                        Set<String> sourceTypes,
                                        Map<String,Source> foundFiles,
                                        Map<String, Module> foundModules,
                                        Module currentModule,
                                        boolean permitSourcesInDefaultPackage,
                                        boolean inLinksrc)
                                                throws IOException {

         for (SourceLocation source : sourceLocations) {
             source.findSourceFiles(sourceTypes,
                                    foundFiles,
                                    foundModules,
                                    currentModule,
                                    permitSourcesInDefaultPackage,
                                    inLinksrc);
         }
     }

     private static void printRound(int round) {
         Log.debug("****************************************");
         Log.debug("* Round " + round + "                              *");
         Log.debug("****************************************");
     }
 }
	/*
	* Copyright (c) 2014, 2016, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
	* questions.
	*/

	package com.sun.tools.sjavac.comp;

	import java.io.IOException;
	import java.io.PrintWriter;
	import java.io.StringWriter;
	import java.nio.file.Files;
	import java.nio.file.Path;
	import java.util.ArrayList;
	import java.util.Collections;
	import java.util.HashMap;
	import java.util.HashSet;
	import java.util.List;
	import java.util.Map;
	import java.util.Set;
	import java.util.stream.Stream;

	import com.sun.tools.javac.file.JavacFileManager;
	import com.sun.tools.javac.main.Main;
	import com.sun.tools.javac.main.Main.Result;
	import com.sun.tools.javac.util.Context;
	import com.sun.tools.sjavac.JavacState;
	import com.sun.tools.sjavac.Log;
	import com.sun.tools.sjavac.Module;
	import com.sun.tools.sjavac.ProblemException;
	import com.sun.tools.sjavac.Source;
	import com.sun.tools.sjavac.Transformer;
	import com.sun.tools.sjavac.Util;
	import com.sun.tools.sjavac.options.Option;
	import com.sun.tools.sjavac.options.Options;
	import com.sun.tools.sjavac.options.SourceLocation;
	import com.sun.tools.sjavac.server.Sjavac;
	import java.io.UncheckedIOException;

	import javax.tools.JavaFileManager;

	/**
	* The sjavac implementation that interacts with javac and performs the actual
	* compilation.
	*
	* <p><b>This is NOT part of any supported API.
	* If you write code that depends on this, you do so at your own risk.
	* This code and its internal interfaces are subject to change or
	* deletion without notice.</b>
	*/
	public class SjavacImpl implements Sjavac {

	@Override
	public Result compile(String[] args) {
	Options options;
	try {
	options = Options.parseArgs(args);
	} catch (IllegalArgumentException e) {
	Log.error(e.getMessage());
	return Result.CMDERR;
	}

	if (!validateOptions(options))
	return Result.CMDERR;

	if (srcDstOverlap(options.getSources(), options.getDestDir())) {
	return Result.CMDERR;
	}

	if (!createIfMissing(options.getDestDir()))
	return Result.ERROR;

	Path stateDir = options.getStateDir();
	if (stateDir != null && !createIfMissing(options.getStateDir()))
	return Result.ERROR;

	Path gensrc = options.getGenSrcDir();
	if (gensrc != null && !createIfMissing(gensrc))
	return Result.ERROR;

	Path hdrdir = options.getHeaderDir();
	if (hdrdir != null && !createIfMissing(hdrdir))
	return Result.ERROR;

	if (stateDir == null) {
	// Prepare context. Direct logging to our byte array stream.
	Context context = new Context();
	StringWriter strWriter = new StringWriter();
	PrintWriter printWriter = new PrintWriter(strWriter);
	com.sun.tools.javac.util.Log.preRegister(context, printWriter);
	JavacFileManager.preRegister(context);

	// Prepare arguments
	String[] passThroughArgs = Stream.of(args)
	.filter(arg -> !arg.startsWith(Option.SERVER.arg))
	.toArray(String[]::new);
	// Compile
	Result result = new Main("javac", printWriter).compile(passThroughArgs, context);

	// Process compiler output (which is always errors)
	printWriter.flush();
	Util.getLines(strWriter.toString()).forEach(Log::error);

	// Clean up
	JavaFileManager fileManager = context.get(JavaFileManager.class);
	if (fileManager instanceof JavacFileManager) {
	try {
	((JavacFileManager) fileManager).close();
	} catch (IOException es) {
	throw new UncheckedIOException(es);
	}
	}
	return result;

	} else {
	// Load the prev build state database.
	JavacState javac_state = JavacState.load(options);

	// Setup the suffix rules from the command line.
	Map<String, Transformer> suffixRules = new HashMap<>();

	// Handling of .java-compilation
	suffixRules.putAll(javac_state.getJavaSuffixRule());

	// Handling of -copy and -tr
	suffixRules.putAll(options.getTranslationRules());

	// All found modules are put here.
	Map<String,Module> modules = new HashMap<>();
	// We start out in the legacy empty no-name module.
	// As soon as we stumble on a module-info.java file we change to that module.
	Module current_module = new Module("", "");
	modules.put("", current_module);

	try {
	// Find all sources, use the suffix rules to know which files are sources.
	Map<String,Source> sources = new HashMap<>();

	// Find the files, this will automatically populate the found modules
	// with found packages where the sources are found!
	findSourceFiles(options.getSources(),
	suffixRules.keySet(),
	sources,
	modules,
	current_module,
	options.isDefaultPackagePermitted(),
	false);

	if (sources.isEmpty()) {
	Log.error("Found nothing to compile!");
	return Result.ERROR;
	}


	// Create a map of all source files that are available for linking. Both -src and
	// -sourcepath point to such files. It is possible to specify multiple
	// -sourcepath options to enable different filtering rules. If the
	// filters are the same for multiple sourcepaths, they may be concatenated
	// using :(;). Before sending the list of sourcepaths to javac, they are
	// all concatenated. The list created here is used by the SmartFileWrapper to
	// make sure only the correct sources are actually available.
	// We might find more modules here as well.
	Map<String,Source> sources_to_link_to = new HashMap<>();

	List<SourceLocation> sourceResolutionLocations = new ArrayList<>();
	sourceResolutionLocations.addAll(options.getSources());
	sourceResolutionLocations.addAll(options.getSourceSearchPaths());
	findSourceFiles(sourceResolutionLocations,
	Collections.singleton(".java"),
	sources_to_link_to,
	modules,
	current_module,
	options.isDefaultPackagePermitted(),
	true);

	// Add the set of sources to the build database.
	javac_state.now().flattenPackagesSourcesAndArtifacts(modules);
	javac_state.now().checkInternalState("checking sources", false, sources);
	javac_state.now().checkInternalState("checking linked sources", true, sources_to_link_to);
	javac_state.setVisibleSources(sources_to_link_to);

	int round = 0;
	printRound(round);

	// If there is any change in the source files, taint packages
	// and mark the database in need of saving.
	javac_state.checkSourceStatus(false);

	// Find all existing artifacts. Their timestamp will match the last modified timestamps stored
	// in javac_state, simply because loading of the JavacState will clean out all artifacts
	// that do not match the javac_state database.
	javac_state.findAllArtifacts();

	// Remove unidentified artifacts from the bin, gensrc and header dirs.
	// (Unless we allow them to be there.)
	// I.e. artifacts that are not known according to the build database (javac_state).
	// For examples, files that have been manually copied into these dirs.
	// Artifacts with bad timestamps (ie the on disk timestamp does not match the timestamp
	// in javac_state) have already been removed when the javac_state was loaded.
	if (!options.areUnidentifiedArtifactsPermitted()) {
	javac_state.removeUnidentifiedArtifacts();
	}
	// Go through all sources and taint all packages that miss artifacts.
	javac_state.taintPackagesThatMissArtifacts();

	// Check recorded classpath public apis. Taint packages that depend on
	// classpath classes whose public apis have changed.
	javac_state.taintPackagesDependingOnChangedClasspathPackages();

	// Now clean out all known artifacts belonging to tainted packages.
	javac_state.deleteClassArtifactsInTaintedPackages();
	// Copy files, for example property files, images files, xml files etc etc.
	javac_state.performCopying(Util.pathToFile(options.getDestDir()), suffixRules);
	// Translate files, for example compile properties or compile idls.
	javac_state.performTranslation(Util.pathToFile(gensrc), suffixRules);
	// Add any potentially generated java sources to the tobe compiled list.
	// (Generated sources must always have a package.)
	Map<String,Source> generated_sources = new HashMap<>();

	Source.scanRoot(Util.pathToFile(options.getGenSrcDir()),
	Util.set(".java"),
	Collections.emptyList(),
	Collections.emptyList(),
	generated_sources,
	modules,
	current_module,
	false,
	true,
	false);
	javac_state.now().flattenPackagesSourcesAndArtifacts(modules);
	// Recheck the the source files and their timestamps again.
	javac_state.checkSourceStatus(true);

	// Now do a safety check that the list of source files is identical
	// to the list Make believes we are compiling. If we do not get this
	// right, then incremental builds will fail with subtility.
	// If any difference is detected, then we will fail hard here.
	// This is an important safety net.
	javac_state.compareWithMakefileList(Util.pathToFile(options.getSourceReferenceList()));

	// Do the compilations, repeatedly until no tainted packages exist.
	boolean again;
	// Collect the name of all compiled packages.
	Set<String> recently_compiled = new HashSet<>();
	boolean[] rc = new boolean[1];

	CompilationService compilationService = new CompilationService();
	do {
	if (round > 0)
	printRound(round);
	// Clean out artifacts in tainted packages.
	javac_state.deleteClassArtifactsInTaintedPackages();
	again = javac_state.performJavaCompilations(compilationService,
	options,
	recently_compiled,
	rc);
	if (!rc[0]) {
	Log.debug("Compilation failed.");
	break;
	}
	if (!again) {
	Log.debug("Nothing left to do.");
	}
	round++;
	} while (again);
	Log.debug("No need to do another round.");

	// Only update the state if the compile went well.
	if (rc[0]) {
	javac_state.save();
	// Reflatten only the artifacts.
	javac_state.now().flattenArtifacts(modules);
	// Remove artifacts that were generated during the last compile, but not this one.
	javac_state.removeSuperfluousArtifacts(recently_compiled);
	}

	return rc[0] ? Result.OK : Result.ERROR;
	} catch (ProblemException e) {
	// For instance make file list mismatch.
	Log.error(e.getMessage());
	Log.debug(e);
	return Result.ERROR;
	} catch (Exception e) {
	Log.error(e);
	return Result.ERROR;
	}
	}
	}

	@Override
	public void shutdown() {
	// Nothing to clean up
	}

	private static boolean validateOptions(Options options) {

	String err = null;

	if (options.getDestDir() == null) {
	err = "Please specify output directory.";
	} else if (options.isJavaFilesAmongJavacArgs()) {
	err = "Sjavac does not handle explicit compilation of single .java files.";
	} else if (!options.getImplicitPolicy().equals("none")) {
	err = "The only allowed setting for sjavac is -implicit:none";
	} else if (options.getSources().isEmpty() && options.getStateDir() != null) {
	err = "You have to specify -src when using --state-dir.";
	} else if (options.getTranslationRules().size() > 1
	&& options.getGenSrcDir() == null) {
	err = "You have translators but no gensrc dir (-s) specified!";
	}

	if (err != null)
	Log.error(err);

	return err == null;

	}

	private static boolean srcDstOverlap(List<SourceLocation> locs, Path dest) {
	for (SourceLocation loc : locs) {
	if (isOverlapping(loc.getPath(), dest)) {
	Log.error("Source location " + loc.getPath() + " overlaps with destination " + dest);
	return true;
	}
	}
	return false;
	}

	private static boolean isOverlapping(Path p1, Path p2) {
	p1 = p1.toAbsolutePath().normalize();
	p2 = p2.toAbsolutePath().normalize();
	return p1.startsWith(p2) \|\| p2.startsWith(p1);
	}

	private static boolean createIfMissing(Path dir) {

	if (Files.isDirectory(dir))
	return true;

	if (Files.exists(dir)) {
	Log.error(dir + " is not a directory.");
	return false;
	}

	try {
	Files.createDirectories(dir);
	} catch (IOException e) {
	Log.error("Could not create directory: " + e.getMessage());
	return false;
	}

	return true;
	}

	/** Find source files in the given source locations. */
	public static void findSourceFiles(List<SourceLocation> sourceLocations,
	Set<String> sourceTypes,
	Map<String,Source> foundFiles,
	Map<String, Module> foundModules,
	Module currentModule,
	boolean permitSourcesInDefaultPackage,
	boolean inLinksrc)
	throws IOException {

	for (SourceLocation source : sourceLocations) {
	source.findSourceFiles(sourceTypes,
	foundFiles,
	foundModules,
	currentModule,
	permitSourcesInDefaultPackage,
	inLinksrc);
	}
	}

	private static void printRound(int round) {
	Log.debug("****************************************");
	Log.debug("* Round " + round + " *");
	Log.debug("****************************************");
	}
	}