dev/core/src/com/google/gwt/dev/javac/CompilationProblemReporter.java - gwt - Git at Google

 /*
  * Copyright 2011 Google Inc.
  *
  * Licensed under the Apache License, Version 2.0 (the "License"); you may not
  * use this file except in compliance with the License. You may obtain a copy of
  * the License at
  *
  * http://www.apache.org/licenses/LICENSE-2.0
  *
  * Unless required by applicable law or agreed to in writing, software
  * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
  * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
  * License for the specific language governing permissions and limitations under
  * the License.
  */
 package com.google.gwt.dev.javac;

 import com.google.gwt.core.ext.TreeLogger;
 import com.google.gwt.core.ext.TreeLogger.HelpInfo;
 import com.google.gwt.core.ext.TreeLogger.Type;
 import com.google.gwt.core.ext.UnableToCompleteException;
 import com.google.gwt.dev.CompilerContext;
 import com.google.gwt.dev.javac.CompilationUnitBuilder.GeneratedCompilationUnit;
 import com.google.gwt.dev.jjs.InternalCompilerException;
 import com.google.gwt.dev.jjs.InternalCompilerException.NodeInfo;
 import com.google.gwt.dev.jjs.SourceInfo;
 import com.google.gwt.dev.util.Messages;
 import com.google.gwt.dev.util.Util;
 import com.google.gwt.thirdparty.guava.common.collect.Lists;

 import org.eclipse.jdt.core.compiler.CategorizedProblem;

 import java.io.File;
 import java.io.IOException;
 import java.net.URL;
 import java.util.HashSet;
 import java.util.LinkedList;
 import java.util.List;
 import java.util.Queue;
 import java.util.Set;

 /**
  * Handles some details of reporting errors in {@link CompilationUnit}s to the
  * console.
  */
 public class CompilationProblemReporter {

   /**
    * Traverses a set of compilation units to record enough information to enable accurate and
    * detailed compilation error cause traces.
    */
   public static void indexErrors(CompilationErrorsIndex compilationErrorsIndex,
       List<CompilationUnit> units) {
     for (CompilationUnit unit : units) {
       if (unit.isError()) {
         Dependencies dependencies = unit.getDependencies();
         compilationErrorsIndex.add(unit.getTypeName(), unit.getResourceLocation(),
             dependencies.getApiRefs(), CompilationProblemReporter.formatErrors(unit));
       }
     }
   }

   /**
    * Used as a convenience to catch all exceptions thrown by the compiler. For
    * instances of {@link InternalCompilerException}, extra diagnostics are
    * printed.
    *
    * @param logger logger used to report errors to the console
    * @param e the exception to analyze and log
    * @return Always returns an instance of {@link UnableToCompleteException} so
    *         that the calling method can declare a more narrow 'throws
    *         UnableToCompleteException'
    */
   public static UnableToCompleteException logAndTranslateException(TreeLogger logger, Throwable e) {
     if (e instanceof UnableToCompleteException) {
       // just rethrow
       return (UnableToCompleteException) e;
     } else if (e instanceof InternalCompilerException) {
       TreeLogger topBranch =
           logger.branch(TreeLogger.ERROR, "An internal compiler exception occurred", e);
       List<NodeInfo> nodeTrace = ((InternalCompilerException) e).getNodeTrace();
       for (NodeInfo nodeInfo : nodeTrace) {
         SourceInfo info = nodeInfo.getSourceInfo();
         String msg;
         if (info != null) {
           String fileName = info.getFileName();
           fileName = fileName.substring(fileName.lastIndexOf('/') + 1);
           fileName = fileName.substring(fileName.lastIndexOf('\\') + 1);
           msg = "at " + fileName + "(" + info.getStartLine() + "): ";
         } else {
           msg = "<no source info>: ";
         }

         String description = nodeInfo.getDescription();
         if (description != null) {
           msg += description;
         } else {
           msg += "<no description available>";
         }
         TreeLogger nodeBranch = topBranch.branch(TreeLogger.ERROR, msg, null);
         String className = nodeInfo.getClassName();
         if (className != null) {
           nodeBranch.log(TreeLogger.INFO, className, null);
         }
       }
       return new UnableToCompleteException();
     } else if (e instanceof VirtualMachineError) {
       // Always rethrow VM errors (an attempt to wrap may fail).
       throw (VirtualMachineError) e;
     } else {
       logger.log(TreeLogger.ERROR, "Unexpected internal compiler error", e);
       return new UnableToCompleteException();
     }
   }

   /**
    * Provides meaningful error messages and hints for types that failed to compile or are otherwise
    * missing.
    */
   public static int logErrorTrace(TreeLogger logger, Type logLevel,
       CompilerContext compilerContext, List<CompilationUnit> units, boolean hint) {
     int errorCount = 0;
     for (CompilationUnit unit : units) {
       if (unit.isError()) {
         logErrorTrace(logger, logLevel, compilerContext, unit.getTypeName(), hint);
         errorCount++;

         if (logger.isLoggable(TreeLogger.INFO) && unit instanceof GeneratedCompilationUnit) {
           CompilationProblemReporter.maybeDumpSource(logger,
               ((GeneratedCompilationUnit) unit).getSource(), unit.getTypeName());
         }
       }
     }
     return errorCount++;
   }

   /**
    * Provides a meaning error message and hints for a type that failed to compile or is otherwise
    * missing.
    */
   public static void logErrorTrace(TreeLogger logger, Type logLevel,
       CompilerContext compilerContext, String typeSourceName, boolean hint) {
     TreeLogger branch = logger.branch(TreeLogger.TRACE,
         "Tracing compile failure path for type '" + typeSourceName + "'");
     if (logErrorChain(branch, logLevel, typeSourceName,
         compilerContext.getCompilationErrorsIndex())) {
       return;
     }

     if (hint) {
       logHints(logger, typeSourceName);
     }
   }

   public static int logWarnings(TreeLogger logger, Type logLevelForWarnings,
       List<CompilationUnit> units) {
     int warningCount = 0;
     for (CompilationUnit unit : units) {
       if (CompilationProblemReporter.logWarnings(logger, logLevelForWarnings, unit)) {
         warningCount++;
       }
     }
     return warningCount++;
   }

   /**
    * Logs errors to the console.
    *
    * @param logger logger for reporting errors to the console
    * @param unit Compilation unit that may have errors
    * @param suppressErrors Controls he log level for logging errors. If <code>false</code> is passed,
    *          compilation errors are logged at TreeLogger.ERROR and warnings logged at
    *          TreeLogger.WARN. If <code>true</code> is passed, compilation errors are logged at
    *          TreeLogger.TRACE and TreeLogger.DEBUG.
    * @return <code>true</code> if an error was logged.
    */
   public static boolean reportErrors(TreeLogger logger, CompilationUnit unit,
       boolean suppressErrors) {
     CategorizedProblem[] problems = unit.getProblems();
     if (problems == null || problems.length == 0) {
       return false;
     }
     String fileName = unit.getResourceLocation();
     boolean isError = unit.isError();
     TreeLogger.Type warnLogLevel;
     TreeLogger.Type errorLogLevel;
     if (suppressErrors) {
       errorLogLevel = TreeLogger.TRACE;
       warnLogLevel = TreeLogger.DEBUG;
     } else {
       errorLogLevel = TreeLogger.ERROR;
       warnLogLevel = TreeLogger.WARN;
     }

     TreeLogger branch = null;
     // Log the errors and GWT warnings.
     for (CategorizedProblem problem : problems) {
       TreeLogger.Type logLevel;
       if (problem.isError()) {
         // Log errors.
         logLevel = errorLogLevel;
         // Only log GWT-specific warnings.
       } else if (problem.isWarning() && problem instanceof GWTProblem) {
         logLevel = warnLogLevel;
       } else {
         // Ignore all other problems.
         continue;
       }

       HelpInfo helpInfo = null;
       if (problem instanceof GWTProblem) {
         GWTProblem gwtProblem = (GWTProblem) problem;
         helpInfo = gwtProblem.getHelpInfo();
       }
       if (branch == null) {
         Type branchType = isError ? errorLogLevel : warnLogLevel;
         String branchString = isError ? "Errors" : "Warnings";
         branch = logger.branch(branchType, branchString + " in '" + fileName + "'", null);
       }
       branch.log(logLevel, toMessageWithLineNumber(problem), null, helpInfo);
     }

     if (branch != null && branch.isLoggable(TreeLogger.INFO)) {
       if (unit instanceof GeneratedCompilationUnit) {
         GeneratedCompilationUnit generatedUnit = (GeneratedCompilationUnit) unit;
         CompilationProblemReporter.maybeDumpSource(branch, generatedUnit.getSource(), unit
             .getTypeName());
       }
     }
     return branch != null;
   }

   private static void addUnitToVisit(CompilationErrorsIndex compilationErrorsIndex,
       String typeSourceName, Queue<String> toVisit, Set<String> visited) {
     if (compilationErrorsIndex.hasCompileErrors(typeSourceName)) {
       if (!visited.contains(typeSourceName)) {
         toVisit.add(typeSourceName);
         visited.add(typeSourceName);
       }
     }
   }

   /**
    * Returns readable compilation error messages for a compilation unit.
    * <p>
    * Should only be run on CompilationUnits that actually have problems.
    */
   private static List<String> formatErrors(CompilationUnit unit) {
     CategorizedProblem[] problems = unit.getProblems();
     assert problems != null && problems.length > 0;

     List<String> errorMessages = Lists.newArrayList();
     for (CategorizedProblem problem : problems) {
       if (!problem.isError()) {
         continue;
       }

       errorMessages.add(toMessageWithLineNumber(problem));
     }

     return errorMessages;
   }

   private static boolean hasWarnings(CompilationUnit unit) {
     CategorizedProblem[] problems = unit.getProblems();
     if (problems == null || problems.length == 0) {
       return false;
     }
     for (CategorizedProblem problem : problems) {
       if (problem.isWarning() && problem instanceof GWTProblem) {
         return true;
       }
     }
     return false;
   }

   private static boolean logErrorChain(TreeLogger logger, Type logLevel,
       String typeSourceName, CompilationErrorsIndex compilationErrorsIndex) {
     final Set<String> visited = new HashSet<String>();
     final Queue<String> toVisit = new LinkedList<String>();

     /*
      * Traverses CompilationUnits enqueued in toVisit(), calling {@link
      * #addUnitsToVisit(String)} as it encounters dependencies on the node. Each
      * CompilationUnit is visited only once, and only if it is reachable via the
      * {@link Dependencies} graph.
      */
     addUnitToVisit(compilationErrorsIndex, typeSourceName, toVisit, visited);

     while (!toVisit.isEmpty()) {
       String dependentTypeSourceName = toVisit.remove();

       Set<String> compileErrors = compilationErrorsIndex.getCompileErrors(dependentTypeSourceName);
       TreeLogger branch = logger.branch(logLevel,
           "Errors in '" + compilationErrorsIndex.getFileName(dependentTypeSourceName) + "'");
       for (String compileError : compileErrors) {
         branch.log(logLevel, compileError);
       }

       Set<String> typeReferences =
           compilationErrorsIndex.getTypeReferences(dependentTypeSourceName);
       if (typeReferences != null) {
         for (String typeReference : typeReferences) {
           addUnitToVisit(compilationErrorsIndex, typeReference, toVisit, visited);
         }
       }
     }
     logger.log(TreeLogger.DEBUG, "Checked " + visited.size() + " dependencies for errors.");
     return visited.size() > 1;
   }

   private static void logHints(TreeLogger logger, String typeSourceName) {
     ClassLoader cl = Thread.currentThread().getContextClassLoader();

     URL sourceURL = Util.findSourceInClassPath(cl, typeSourceName);
     if (sourceURL != null) {
       if (typeSourceName.indexOf(".client.") != -1) {
         Messages.HINT_CHECK_MODULE_INHERITANCE.log(logger, null);
       } else {
         Messages.HINT_CHECK_MODULE_NONCLIENT_SOURCE_DECL.log(logger, null);
       }
     } else if (!typeSourceName.equals("java.lang.Object")) {
       Messages.HINT_CHECK_TYPENAME.log(logger, typeSourceName, null);
       Messages.HINT_CHECK_CLASSPATH_SOURCE_ENTRIES.log(logger, null);
     }

     /*
      * For missing JRE emulated classes (e.g. Object), or the main GWT libraries, there are special
      * warnings.
      */
     if (typeSourceName.indexOf("java.lang.") == 0
         || typeSourceName.indexOf("com.google.gwt.core.") == 0) {
       Messages.HINT_CHECK_INHERIT_CORE.log(logger, null);
     } else if (typeSourceName.indexOf("com.google.gwt.user.") == 0) {
       Messages.HINT_CHECK_INHERIT_USER.log(logger, null);
     }
   }

   private static boolean logWarnings(TreeLogger logger, TreeLogger.Type logLevel,
       CompilationUnit unit) {
     if (!hasWarnings(unit)) {
       return false;
     }

     TreeLogger branch =
         logger.branch(logLevel, "Warnings in '" + unit.getResourceLocation() + "'", null);
     for (CategorizedProblem problem : unit.getProblems()) {
       if (!problem.isWarning() || !(problem instanceof GWTProblem)) {
         continue;
       }

       branch.log(logLevel, toMessageWithLineNumber(problem), null,
           ((GWTProblem) problem).getHelpInfo());
     }

     if (branch.isLoggable(TreeLogger.INFO) && unit instanceof GeneratedCompilationUnit) {
       CompilationProblemReporter.maybeDumpSource(branch,
           ((GeneratedCompilationUnit) unit).getSource(), unit.getTypeName());
     }
     return true;
   }

   /**
    * Give the developer a chance to see the in-memory source that failed.
    */
   private static void maybeDumpSource(TreeLogger logger, String source, String typeName) {
     File tmpSrc;
     Throwable caught = null;
     try {
       // The tempFile prefix must be at least 3 characters
       while (typeName.length() < 3) {
         typeName = "_" + typeName;
       }
       tmpSrc = File.createTempFile(typeName, ".java");
       Util.writeStringAsFile(tmpSrc, source);
       String dumpPath = tmpSrc.getAbsolutePath();
       if (logger.isLoggable(TreeLogger.INFO)) {
         logger.log(TreeLogger.INFO, "See snapshot: " + dumpPath, null);
       }
       return;
     } catch (IOException e) {
       caught = e;
     }
     logger.log(TreeLogger.INFO, "Unable to dump source to disk", caught);
   }

   private static String toMessageWithLineNumber(CategorizedProblem problem) {
     int lineNumber = problem.getSourceLineNumber();
     return (lineNumber > 0 ? "Line " + lineNumber + ": " : "") + problem.getMessage();
   }
 }
	/*
	* Copyright 2011 Google Inc.
	*
	* Licensed under the Apache License, Version 2.0 (the "License"); you may not
	* use this file except in compliance with the License. You may obtain a copy of
	* the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
	* WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
	* License for the specific language governing permissions and limitations under
	* the License.
	*/
	package com.google.gwt.dev.javac;

	import com.google.gwt.core.ext.TreeLogger;
	import com.google.gwt.core.ext.TreeLogger.HelpInfo;
	import com.google.gwt.core.ext.TreeLogger.Type;
	import com.google.gwt.core.ext.UnableToCompleteException;
	import com.google.gwt.dev.CompilerContext;
	import com.google.gwt.dev.javac.CompilationUnitBuilder.GeneratedCompilationUnit;
	import com.google.gwt.dev.jjs.InternalCompilerException;
	import com.google.gwt.dev.jjs.InternalCompilerException.NodeInfo;
	import com.google.gwt.dev.jjs.SourceInfo;
	import com.google.gwt.dev.util.Messages;
	import com.google.gwt.dev.util.Util;
	import com.google.gwt.thirdparty.guava.common.collect.Lists;

	import org.eclipse.jdt.core.compiler.CategorizedProblem;

	import java.io.File;
	import java.io.IOException;
	import java.net.URL;
	import java.util.HashSet;
	import java.util.LinkedList;
	import java.util.List;
	import java.util.Queue;
	import java.util.Set;

	/**
	* Handles some details of reporting errors in {@link CompilationUnit}s to the
	* console.
	*/
	public class CompilationProblemReporter {

	/**
	* Traverses a set of compilation units to record enough information to enable accurate and
	* detailed compilation error cause traces.
	*/
	public static void indexErrors(CompilationErrorsIndex compilationErrorsIndex,
	List<CompilationUnit> units) {
	for (CompilationUnit unit : units) {
	if (unit.isError()) {
	Dependencies dependencies = unit.getDependencies();
	compilationErrorsIndex.add(unit.getTypeName(), unit.getResourceLocation(),
	dependencies.getApiRefs(), CompilationProblemReporter.formatErrors(unit));
	}
	}
	}

	/**
	* Used as a convenience to catch all exceptions thrown by the compiler. For
	* instances of {@link InternalCompilerException}, extra diagnostics are
	* printed.
	*
	* @param logger logger used to report errors to the console
	* @param e the exception to analyze and log
	* @return Always returns an instance of {@link UnableToCompleteException} so
	* that the calling method can declare a more narrow 'throws
	* UnableToCompleteException'
	*/
	public static UnableToCompleteException logAndTranslateException(TreeLogger logger, Throwable e) {
	if (e instanceof UnableToCompleteException) {
	// just rethrow
	return (UnableToCompleteException) e;
	} else if (e instanceof InternalCompilerException) {
	TreeLogger topBranch =
	logger.branch(TreeLogger.ERROR, "An internal compiler exception occurred", e);
	List<NodeInfo> nodeTrace = ((InternalCompilerException) e).getNodeTrace();
	for (NodeInfo nodeInfo : nodeTrace) {
	SourceInfo info = nodeInfo.getSourceInfo();
	String msg;
	if (info != null) {
	String fileName = info.getFileName();
	fileName = fileName.substring(fileName.lastIndexOf('/') + 1);
	fileName = fileName.substring(fileName.lastIndexOf('\\') + 1);
	msg = "at " + fileName + "(" + info.getStartLine() + "): ";
	} else {
	msg = "<no source info>: ";
	}

	String description = nodeInfo.getDescription();
	if (description != null) {
	msg += description;
	} else {
	msg += "<no description available>";
	}
	TreeLogger nodeBranch = topBranch.branch(TreeLogger.ERROR, msg, null);
	String className = nodeInfo.getClassName();
	if (className != null) {
	nodeBranch.log(TreeLogger.INFO, className, null);
	}
	}
	return new UnableToCompleteException();
	} else if (e instanceof VirtualMachineError) {
	// Always rethrow VM errors (an attempt to wrap may fail).
	throw (VirtualMachineError) e;
	} else {
	logger.log(TreeLogger.ERROR, "Unexpected internal compiler error", e);
	return new UnableToCompleteException();
	}
	}

	/**
	* Provides meaningful error messages and hints for types that failed to compile or are otherwise
	* missing.
	*/
	public static int logErrorTrace(TreeLogger logger, Type logLevel,
	CompilerContext compilerContext, List<CompilationUnit> units, boolean hint) {
	int errorCount = 0;
	for (CompilationUnit unit : units) {
	if (unit.isError()) {
	logErrorTrace(logger, logLevel, compilerContext, unit.getTypeName(), hint);
	errorCount++;

	if (logger.isLoggable(TreeLogger.INFO) && unit instanceof GeneratedCompilationUnit) {
	CompilationProblemReporter.maybeDumpSource(logger,
	((GeneratedCompilationUnit) unit).getSource(), unit.getTypeName());
	}
	}
	}
	return errorCount++;
	}

	/**
	* Provides a meaning error message and hints for a type that failed to compile or is otherwise
	* missing.
	*/
	public static void logErrorTrace(TreeLogger logger, Type logLevel,
	CompilerContext compilerContext, String typeSourceName, boolean hint) {
	TreeLogger branch = logger.branch(TreeLogger.TRACE,
	"Tracing compile failure path for type '" + typeSourceName + "'");
	if (logErrorChain(branch, logLevel, typeSourceName,
	compilerContext.getCompilationErrorsIndex())) {
	return;
	}

	if (hint) {
	logHints(logger, typeSourceName);
	}
	}

	public static int logWarnings(TreeLogger logger, Type logLevelForWarnings,
	List<CompilationUnit> units) {
	int warningCount = 0;
	for (CompilationUnit unit : units) {
	if (CompilationProblemReporter.logWarnings(logger, logLevelForWarnings, unit)) {
	warningCount++;
	}
	}
	return warningCount++;
	}

	/**
	* Logs errors to the console.
	*
	* @param logger logger for reporting errors to the console
	* @param unit Compilation unit that may have errors
	* @param suppressErrors Controls he log level for logging errors. If <code>false</code> is passed,
	* compilation errors are logged at TreeLogger.ERROR and warnings logged at
	* TreeLogger.WARN. If <code>true</code> is passed, compilation errors are logged at
	* TreeLogger.TRACE and TreeLogger.DEBUG.
	* @return <code>true</code> if an error was logged.
	*/
	public static boolean reportErrors(TreeLogger logger, CompilationUnit unit,
	boolean suppressErrors) {
	CategorizedProblem[] problems = unit.getProblems();
	if (problems == null \|\| problems.length == 0) {
	return false;
	}
	String fileName = unit.getResourceLocation();
	boolean isError = unit.isError();
	TreeLogger.Type warnLogLevel;
	TreeLogger.Type errorLogLevel;
	if (suppressErrors) {
	errorLogLevel = TreeLogger.TRACE;
	warnLogLevel = TreeLogger.DEBUG;
	} else {
	errorLogLevel = TreeLogger.ERROR;
	warnLogLevel = TreeLogger.WARN;
	}

	TreeLogger branch = null;
	// Log the errors and GWT warnings.
	for (CategorizedProblem problem : problems) {
	TreeLogger.Type logLevel;
	if (problem.isError()) {
	// Log errors.
	logLevel = errorLogLevel;
	// Only log GWT-specific warnings.
	} else if (problem.isWarning() && problem instanceof GWTProblem) {
	logLevel = warnLogLevel;
	} else {
	// Ignore all other problems.
	continue;
	}

	HelpInfo helpInfo = null;
	if (problem instanceof GWTProblem) {
	GWTProblem gwtProblem = (GWTProblem) problem;
	helpInfo = gwtProblem.getHelpInfo();
	}
	if (branch == null) {
	Type branchType = isError ? errorLogLevel : warnLogLevel;
	String branchString = isError ? "Errors" : "Warnings";
	branch = logger.branch(branchType, branchString + " in '" + fileName + "'", null);
	}
	branch.log(logLevel, toMessageWithLineNumber(problem), null, helpInfo);
	}

	if (branch != null && branch.isLoggable(TreeLogger.INFO)) {
	if (unit instanceof GeneratedCompilationUnit) {
	GeneratedCompilationUnit generatedUnit = (GeneratedCompilationUnit) unit;
	CompilationProblemReporter.maybeDumpSource(branch, generatedUnit.getSource(), unit
	.getTypeName());
	}
	}
	return branch != null;
	}

	private static void addUnitToVisit(CompilationErrorsIndex compilationErrorsIndex,
	String typeSourceName, Queue<String> toVisit, Set<String> visited) {
	if (compilationErrorsIndex.hasCompileErrors(typeSourceName)) {
	if (!visited.contains(typeSourceName)) {
	toVisit.add(typeSourceName);
	visited.add(typeSourceName);
	}
	}
	}

	/**
	* Returns readable compilation error messages for a compilation unit.
	* <p>
	* Should only be run on CompilationUnits that actually have problems.
	*/
	private static List<String> formatErrors(CompilationUnit unit) {
	CategorizedProblem[] problems = unit.getProblems();
	assert problems != null && problems.length > 0;

	List<String> errorMessages = Lists.newArrayList();
	for (CategorizedProblem problem : problems) {
	if (!problem.isError()) {
	continue;
	}

	errorMessages.add(toMessageWithLineNumber(problem));
	}

	return errorMessages;
	}

	private static boolean hasWarnings(CompilationUnit unit) {
	CategorizedProblem[] problems = unit.getProblems();
	if (problems == null \|\| problems.length == 0) {
	return false;
	}
	for (CategorizedProblem problem : problems) {
	if (problem.isWarning() && problem instanceof GWTProblem) {
	return true;
	}
	}
	return false;
	}

	private static boolean logErrorChain(TreeLogger logger, Type logLevel,
	String typeSourceName, CompilationErrorsIndex compilationErrorsIndex) {
	final Set<String> visited = new HashSet<String>();
	final Queue<String> toVisit = new LinkedList<String>();

	/*
	* Traverses CompilationUnits enqueued in toVisit(), calling {@link
	* #addUnitsToVisit(String)} as it encounters dependencies on the node. Each
	* CompilationUnit is visited only once, and only if it is reachable via the
	* {@link Dependencies} graph.
	*/
	addUnitToVisit(compilationErrorsIndex, typeSourceName, toVisit, visited);

	while (!toVisit.isEmpty()) {
	String dependentTypeSourceName = toVisit.remove();

	Set<String> compileErrors = compilationErrorsIndex.getCompileErrors(dependentTypeSourceName);
	TreeLogger branch = logger.branch(logLevel,
	"Errors in '" + compilationErrorsIndex.getFileName(dependentTypeSourceName) + "'");
	for (String compileError : compileErrors) {
	branch.log(logLevel, compileError);
	}

	Set<String> typeReferences =
	compilationErrorsIndex.getTypeReferences(dependentTypeSourceName);
	if (typeReferences != null) {
	for (String typeReference : typeReferences) {
	addUnitToVisit(compilationErrorsIndex, typeReference, toVisit, visited);
	}
	}
	}
	logger.log(TreeLogger.DEBUG, "Checked " + visited.size() + " dependencies for errors.");
	return visited.size() > 1;
	}

	private static void logHints(TreeLogger logger, String typeSourceName) {
	ClassLoader cl = Thread.currentThread().getContextClassLoader();

	URL sourceURL = Util.findSourceInClassPath(cl, typeSourceName);
	if (sourceURL != null) {
	if (typeSourceName.indexOf(".client.") != -1) {
	Messages.HINT_CHECK_MODULE_INHERITANCE.log(logger, null);
	} else {
	Messages.HINT_CHECK_MODULE_NONCLIENT_SOURCE_DECL.log(logger, null);
	}
	} else if (!typeSourceName.equals("java.lang.Object")) {
	Messages.HINT_CHECK_TYPENAME.log(logger, typeSourceName, null);
	Messages.HINT_CHECK_CLASSPATH_SOURCE_ENTRIES.log(logger, null);
	}

	/*
	* For missing JRE emulated classes (e.g. Object), or the main GWT libraries, there are special
	* warnings.
	*/
	if (typeSourceName.indexOf("java.lang.") == 0
	\|\| typeSourceName.indexOf("com.google.gwt.core.") == 0) {
	Messages.HINT_CHECK_INHERIT_CORE.log(logger, null);
	} else if (typeSourceName.indexOf("com.google.gwt.user.") == 0) {
	Messages.HINT_CHECK_INHERIT_USER.log(logger, null);
	}
	}

	private static boolean logWarnings(TreeLogger logger, TreeLogger.Type logLevel,
	CompilationUnit unit) {
	if (!hasWarnings(unit)) {
	return false;
	}

	TreeLogger branch =
	logger.branch(logLevel, "Warnings in '" + unit.getResourceLocation() + "'", null);
	for (CategorizedProblem problem : unit.getProblems()) {
	if (!problem.isWarning() \|\| !(problem instanceof GWTProblem)) {
	continue;
	}

	branch.log(logLevel, toMessageWithLineNumber(problem), null,
	((GWTProblem) problem).getHelpInfo());
	}

	if (branch.isLoggable(TreeLogger.INFO) && unit instanceof GeneratedCompilationUnit) {
	CompilationProblemReporter.maybeDumpSource(branch,
	((GeneratedCompilationUnit) unit).getSource(), unit.getTypeName());
	}
	return true;
	}

	/**
	* Give the developer a chance to see the in-memory source that failed.
	*/
	private static void maybeDumpSource(TreeLogger logger, String source, String typeName) {
	File tmpSrc;
	Throwable caught = null;
	try {
	// The tempFile prefix must be at least 3 characters
	while (typeName.length() < 3) {
	typeName = "_" + typeName;
	}
	tmpSrc = File.createTempFile(typeName, ".java");
	Util.writeStringAsFile(tmpSrc, source);
	String dumpPath = tmpSrc.getAbsolutePath();
	if (logger.isLoggable(TreeLogger.INFO)) {
	logger.log(TreeLogger.INFO, "See snapshot: " + dumpPath, null);
	}
	return;
	} catch (IOException e) {
	caught = e;
	}
	logger.log(TreeLogger.INFO, "Unable to dump source to disk", caught);
	}

	private static String toMessageWithLineNumber(CategorizedProblem problem) {
	int lineNumber = problem.getSourceLineNumber();
	return (lineNumber > 0 ? "Line " + lineNumber + ": " : "") + problem.getMessage();
	}
	}